Objective Long noncoding RNAs(lncRNAs)and microRNAs(miRNAs)are widely expressed in the brain and are associated with the development of neurological and neurodegenerative diseases.However,their roles and molecular mec...Objective Long noncoding RNAs(lncRNAs)and microRNAs(miRNAs)are widely expressed in the brain and are associated with the development of neurological and neurodegenerative diseases.However,their roles and molecular mechanisms in major depressive disorder(MDD)remain largely unknown.This study aimed to identify lncRNAs and miRNAs involved in the development of MDD and elucidate their molecular mechanisms.Methods Transcriptome and bioinformatic analyses were performed to identify miRNAs and lncRNAs related to MDD.C57 mice were subjected to chronic unpredictable mild stress(CUMS)to establish a depression model.Lentiviruses containing either lncRNA NPTN-IT1-201 or miR-142-5p were microinjected into the hippocampal region of these mice.Behavioral tests including the sucrose preference test(SPT),tail suspension test(TST),and forced swim test(FST)were conducted to evaluate depressive-like behaviors.Results The results revealed that overexpression of lncRNA NPTN-IT1-201 or inhibition of miR-142-5p significantly ameliorated depressive-like behaviors in CUMS-treated mice.Dual-luciferase reporter assays confirmed interactions between miR-142-5p with both brain-derived neurotrophic factor(BDNF)and NPTN-IT1-201.ELISA analysis revealed significant alterations in relevant biomarkers in the blood samples of MDD patients compared to healthy controls.Histological analyses,including HE and Nissl staining,showed marked structural changes in brain tissues following CUMS treatment,which were partially reversed by lncRNA NPTN-IT1-201 overexpression or miR-142-5p inhibition.Immunofluorescence imaging demonstrated significant differences in the levels of BAX,Bcl2,p65,Iba1 among different treatment groups.TUNEL assays confirmed reduced apoptosis in brain tissues following these interventions.Western blotting showed the significant differences in BDNF,BAX,and Bcl2 protein levels among different treatment groups.Conclusion NPTN-IT1-201 regulates inflammation and apoptosis in MDD by targeting BDNF via miR-142-5p,making it a potential therapeutic target for MDD.展开更多
Low salt intake is associated with depression, but the experimental evidence is not clear. Sixty adult mice were randomly divided into four groups (mild, moderate and severe salt deficiency groups and control) during ...Low salt intake is associated with depression, but the experimental evidence is not clear. Sixty adult mice were randomly divided into four groups (mild, moderate and severe salt deficiency groups and control) during the seasonal splitting from winter to spring. The mice in the control group were fed with standard ordinary diet (salt content 0.26%), while in the mild, moderate and severe groups, the mice were fed with 10%, 30% and 50% salt deficient feedstuff, lasting for approximately 3 months. The results showed that the salt content of feed was negatively correlated with the food intake and body weight of mice. The sucrose preference test found that only the mild salt deficiency group had no differ-ence between the beginning and the end of the experiment, and the other three groups in-cluding the control, showed a significant decrease. These results suggest that dietary salt content has an impact on the food intake and body weight of mice and is associated with the emergence of depressive-like behavior. Furthermore, the seasonal splitting from winter to spring may also have a differential synergistic effect on the change of depression-like behavior associated with low salt intake in mice.展开更多
The main objective of this work was to 1) study the influence of endogenous melatonin (Mel) abolishment via pinealectomy and 2) explore exogenous Mel effect on anxiety-like and depressive-like behavior in male and fem...The main objective of this work was to 1) study the influence of endogenous melatonin (Mel) abolishment via pinealectomy and 2) explore exogenous Mel effect on anxiety-like and depressive-like behavior in male and female rats. Rats were shamoperated (Sh) or pinealectomized (Px) and following subgroups were selected 1) Px/NaCl (0.9%) and Sh/NaCl (0.9%) : rats injected subcutaneously, once daily for 8 weeks, with saline solution NaCl (0.9%) as vehicle;2) Px/Mel (4 mg/Kg) and Sh/Mel (4 mg/Kg): Rats similarly injected with 4 mg/Kg of Mel. All animals were housed under a photoperiod of (LD:16/8). After different treatments animals were tested in the open-field test (OFT), elevated plus maze test (EPM) to determine anxiety-like behavior, and forced swimming test (FST) to evaluate depressive-like level. Our results revealed that level of anxiety-like and depressive-like behavior are significantly higher in Px/NaCl (0.9%) when compared to Sh/NaCl (0.9%) group, suggesting that pinelectomy induced an anxiogenic and depressant effects. The Px effects would be due to the absence of endogenous Mel synthesis and release. Additionally, we clearly demonstrated that the level of anxiety-like and depressive-like behavior are higher in Px/Mel (4 mg/Kg) and Sh/Mel when compared respectively to Px/NaCl (4 mg/Kg) and Sh/NaCl groups suggesting an anxiolytic and antidepressant effects of exogenous Mel. Behavioral responses were sex dependent since the difference between females and males, especially, after melatonin administration, were statistically significant. These experiments provide evidence that pinealectomy and Mel regulated emotionally behavior in male and female rats.展开更多
Aim To investigate the mechanisms underlying depressive-like behavior induced by chronic cerebral is- chemia in rats. Methods In the present study, a chronic cerebral hypoperfusion model was established by perma- 2VO...Aim To investigate the mechanisms underlying depressive-like behavior induced by chronic cerebral is- chemia in rats. Methods In the present study, a chronic cerebral hypoperfusion model was established by perma- 2VO) in rats. Two weeks after 2VO, GAB- nent bilateral common carotid arteries occlusion (two-vessel occlusion, AB receptor agonist baclofen (25 mg · kg^-1 . d^-1 i p ) was administrated for 21 days. The FST was performed to evaluate depressive-like behavior in which the immobility time was recorded. In addition, the expression of brain derived neurotrophic factor (BDNF) in hippocampal CA1 was measured by Western blot. Results The immobility time of 2VO group was significantly prolonged and the expression of BDNF was decreased by 28.95% compared with sham group. After activation of GABAB receptors by baclofen, the immobility time was significantly reduced and the expression of BDNF was increased by 47.91% compared with 2VO group. Conclusion 2VO induced ob- vious depressive-like behavior in rats. Activation of GABAB receptors alleviates the depressive-like behavior in- duced by chronic cerebral ischemia via upredulation of BDNF in hippocampal CA1 in rats.展开更多
OBJECTIVEα-Dstroglycan(α-DG)is a predominant component in the dystrophin-glycoprotein complex(DGC)and a recently char⁃acterized receptor for several extracellular matrix components with high affinity.Recent research...OBJECTIVEα-Dstroglycan(α-DG)is a predominant component in the dystrophin-glycoprotein complex(DGC)and a recently char⁃acterized receptor for several extracellular matrix components with high affinity.Recent research⁃es have reported that hypoglycosylation ofα-DG is associated with the pathophysiology of diseas⁃es,especially muscular dystrophy,but little is known about major depressive disorder(MDD).Like-acetylglucosaminyl transferase(Large)is a key enzyme for glycosylation ofα-DG,which mainly modifies two points in the middle domain ofα-DG:Thr-317 and Thr-319.Glycosylatedα-DG(GLY-α-DG)can bind with high affinity to extracellular matrix(ECM)molecules that con⁃tain laminin globular(LG)domains,including per⁃lecan,agrin and neurexin.Agrin is mainly derived from neurons rather than glial cells.In cultured hippocampal neurons,it was found that agrin could regulate the homeostatic plasticity of inhibi⁃tory neurons by acting on GLY-α-DG.Mdx mice are transgenetic models for the investigation of Duchenne muscular dystrophy.Many studies have shown that the expression of GLY-α-DG in the peripheral and brain tissues of Mdx mice is significantly down-regulated.Mdx mice show cognitive impairment and high levels of anxiety.In this study,we employed chronic social defeat stress(CSDS)to establish an animal model of depression and detected the expression of GLY-α-DG among the brain areas associated with the pathophysiology of depression.METHODS So⁃cial interaction test(SIT)and sucrose preference test(SPT)were used to evaluate depressive-like behavior.Open field(OF)and elevated plus maze(EPM)test were used to determine the anxiety-like behavior of Mdx mice.Novelty-sup⁃pressed feeding test(NSFT)forced swim test(FST)and tail suspension test(TST)were used to detect the depressive-like behavior of Mdx mice.Novel object recognition test(NOR)was applied to evaluate the cognition of Mdx mice.Subthreshold social defeat stress was used to explore the susceptibility to stress in Mdx mice.Stereotactic infusion of agrin into the ventral hippocampus(vHip),FST and TST were used to investigate the antidepressant effects of agrin.Adeno-associated virus(AAV)-mediated overex⁃pression techniques,behavior tests and whole-cell path-clamp technique were conducted to determine the impact of Large overexpression on CSDS susceptible mice.RESULTS The expres⁃sion ofα-DG and GLY-α-DG were significantly decreased in the vHip of CSDS susceptible mice.Mdx mice showed decreased expression of GLY-α-DG and increased anxiety-like behav⁃iors.Mdx mice displayed some depressive-like behaviors,and the susceptibility to stress was significantly increased.Downregulation of the expressionα-DG in the vHip by lentivirus increased the susceptibility to stress.Administra⁃tion of agrin to CSDS susceptible mice exerted antidepressant effects,and this effect could par⁃tially sustain for a week.The expression of Large was decreased in vHip.Overexpression of Large through AAV-Large reversed the depressive-like behaviors and restored the decreased frequency and amplitude of mIPSC.CONCLUSION GLY-α-DG and its glycosylase are significantly decreased in CSDS susceptible mice.Adminis⁃tration of agrin and overexpression of Large displays antidepressant effect,which may be related to its promotion of inhibitory synaptic transmission.展开更多
OBJECTIVE Alcohol dependence is not only the most common public health prob⁃lem worldwide,but also the cause of many alco⁃hol-related diseases,such as anxiety and depres⁃sion.However,the mechanism of these comor⁃bidit...OBJECTIVE Alcohol dependence is not only the most common public health prob⁃lem worldwide,but also the cause of many alco⁃hol-related diseases,such as anxiety and depres⁃sion.However,the mechanism of these comor⁃bidities is not clear.Recently,the role of phos⁃phodiesterases(PDEs)in anxiety-and depres⁃sion-like behavior induced by alcohol withdrawal has received increasing attentions.PDEs are a superfamily of enzymes that catalyze the hydroly⁃sis of intracellular cyclic AMP(cAMP)and(or)cyclic GMP(cGMP).There are 11 families(PDE1-PDE11),each of which has 1 to 4 sub⁃types encoded by different genes.In the present study,we identified the key PDEs involved in anxiety-and depression-like behavior induced by alcohol withdrawal.METHODS After withdrawal from short-term or chronic intermittent ethanol vapor exposure(STEVE and CIEVE,respectively),adult male C57BL/6J(B6)mice were tested for anxiety-and depression-like behavior using the sucrose preference,open field,elevated plus-maze,tail suspension,forced swimming,hole board and light-dark tests.In addition,the expression of PDE subtypes(PDE2,PDE4,and PDE7)in the hippocampus,amygdala,and stria⁃tum,which are considered as anxiety-and(or)depression-related brain regions,was detected by Western blotting.RESULTS①Differences in anxiety-and depression-like behaviors between STEVE and CIEVE mice.Compared to STEVE mice,CIEVE mice showed greater anxiety-and depression-like behavior in the tests described above.②The expression of PDE2,PDE4 and PDE7 in the anxiety-and depression-related brain regions of CIEVE mice.Compared to the STEVE mice,CIEVE mice showed significant higher expression of PDE4A and PDE7A in the hippo⁃campus(P<0.05)and PDE4D and PDE7A in the amygdala(P<0.05).However,the expres⁃sion of PDE2A,PDE4B,PDE4D and PDE7B in the hippocampus,PDE2A,PDE4A,PDE4B and PDE7B in the amygdala,PDE2A,PDE4A,PDE4B,PDE4D,PDE7A and PDE7B in the striatum was not significantly changed.CONCLUSION The model of CIEVE showed significant anxiety-and depression-like behavior,with concurrent increases in the expression of PDE4A and PDE7A in the hippocampus and PDE4D and PDE7A in the amygdala.These results suggest that PDE4A,PDE4D,and DE7A may play an important role in the regulation of anxiety-and depression-like behavior induced by alcohol withdrawal.展开更多
Magnesium(Mg)alloys are considered to be a new generation of revolutionary medical metals.Laser-beam powder bed fusion(PBF-LB)is suitable for fabricating metal implants withpersonalized and complicated structures.Howe...Magnesium(Mg)alloys are considered to be a new generation of revolutionary medical metals.Laser-beam powder bed fusion(PBF-LB)is suitable for fabricating metal implants withpersonalized and complicated structures.However,the as-built part usually exhibits undesirable microstructure and unsatisfactory performance.In this work,WE43 parts were firstly fabricated by PBF-LB and then subjected to heat treatment.Although a high densification rate of 99.91%was achieved using suitable processes,the as-built parts exhibited anisotropic and layeredmicrostructure with heterogeneously precipitated Nd-rich intermetallic.After heat treatment,fine and nano-scaled Mg24Y5particles were precipitated.Meanwhile,theα-Mg grainsunderwent recrystallization and turned coarsened slightly,which effectively weakened thetexture intensity and reduced the anisotropy.As a consequence,the yield strength and ultimate tensile strength were significantly improved to(250.2±3.5)MPa and(312±3.7)MPa,respectively,while the elongation was still maintained at a high level of 15.2%.Furthermore,the homogenized microstructure reduced the tendency of localized corrosion and favoredthe development of uniform passivation film.Thus,the degradation rate of WE43 parts was decreased by an order of magnitude.Besides,in-vitro cell experiments proved their favorable biocompatibility.展开更多
A growing number of studies have demonstrated that repeated exposure to sevoflurane during development results in persistent social abnormalities and cognitive impairment.Davunetide,an active fragment of the activity-...A growing number of studies have demonstrated that repeated exposure to sevoflurane during development results in persistent social abnormalities and cognitive impairment.Davunetide,an active fragment of the activity-dependent neuroprotective protein(ADNP),has been implicated in social and cognitive protection.However,the potential of davunetide to attenuate social deficits following sevoflurane exposure and the underlying developmental mechanisms remain poorly understood.In this study,ribosome and proteome profiles were analyzed to investigate the molecular basis of sevoflurane-induced social deficits in neonatal mice.The neuropathological basis was also explored using Golgi staining,morphological analysis,western blotting,electrophysiological analysis,and behavioral analysis.Results indicated that ADNP was significantly down-regulated following developmental exposure to sevoflurane.In adulthood,anterior cingulate cortex(ACC)neurons exposed to sevoflurane exhibited a decrease in dendrite number,total dendrite length,and spine density.Furthermore,the expression levels of Homer,PSD95,synaptophysin,and vglut2 were significantly reduced in the sevoflurane group.Patch-clamp recordings indicated reductions in both the frequency and amplitude of miniature excitatory postsynaptic currents(mEPSCs).Notably,davunetide significantly ameliorated the synaptic defects,social behavior deficits,and cognitive impairments induced by sevoflurane.Mechanistic analysis revealed that loss of ADNP led to dysregulation of Ca^(2+)activity via the Wnt/β-catenin signaling,resulting in decreased expression of synaptic proteins.Suppression of Wnt signaling was restored in the davunetide-treated group.Thus,ADNP was identified as a promising therapeutic target for the prevention and treatment of neurodevelopmental toxicity caused by general anesthetics.This study provides important insights into the mechanisms underlying social and cognitive disturbances caused by sevoflurane exposure in neonatal mice and elucidates the regulatory pathways involved.展开更多
BACKGROUND Parental behaviors are key in shaping children’s psychological and behavioral development,crucial for early identification and prevention of mental health issues,reducing psychological trauma in childhood....BACKGROUND Parental behaviors are key in shaping children’s psychological and behavioral development,crucial for early identification and prevention of mental health issues,reducing psychological trauma in childhood.AIM To investigate the relationship between parenting behaviors and behavioral and emotional issues in preschool children.METHODS From October 2017 to May 2018,7 kindergartens in Ma’anshan City were selected to conduct a parent self-filled questionnaire-Health Development Survey of Preschool Children.Children’s Strength and Difficulties Questionnaire(Parent Version)was applied to measures the children’s behavioral and emotional performance.Parenting behavior was evaluated using the Parental Behavior Inventory.Binomial logistic regression model was used to analyze the association between the detection rate of preschool children’s behavior and emotional problems and their parenting behaviors.RESULTS High level of parental support/participation was negatively correlated with conduct problems,abnormal hyperactivity,abnormal total difficulty scores and abnormal prosocial behavior problems.High level of maternal support/participation was negatively correlated with abnormal emotional symptoms and abnormal peer interaction in children.High level of parental hostility/coercion was positively correlated with abnormal emotional symptoms,abnormal conduct problems,abnormal hyperactivity,abnormal peer interaction,and abnormal total difficulty scores in children(all P<0.05).Moreover,paternal parenting behaviors had similarly effects on behavior and emotional problems of preschool children compared with maternal parenting behaviors(all P>0.05),after calculating ratio of odds ratio values.CONCLUSION Our study found that parenting behaviors are associated with behavioral and emotional issues in preschool children.Overall,the more supportive or involved the parents are,the fewer behavioral and emotional problems the children experience;conversely,the more hostile or controlling the parents are,the more behavioral and emotional problems the children face.Moreover,the impact of fathers’parenting behaviors on preschool children’s behavior and emotions is no less significant than that of mothers’parenting behaviors.展开更多
A series of direct shear tests under constant normal loading conditions were carried out on specimens of bolted sandstone single-joint treated with different numbers of dryewet cycles.The experimental results show tha...A series of direct shear tests under constant normal loading conditions were carried out on specimens of bolted sandstone single-joint treated with different numbers of dryewet cycles.The experimental results show that the peak shear strength and shear stiffness of bolted sandstone joints were significantly reduced after 12 dryewet cycles.The decrease in the shear strength of rough joints is more significant than that of flat joints.Due to the decrease in the strength of the surrounding rock,the deformation characteristics of the bolts are significantly affected by the number of dryewet cycles performed.With an increase in the number of dryewet cycles,the plastic hinge length of the bolt gradually increases,resulting in an increase in the corresponding shear displacement when the bolt breaks.Compared with the tensileeshear failure mode of the bolts in flat joints,the tensileebending failure mode arises for bolts in rough joints.A shear curve model describing the whole process of bolted rock joints is established based on the deterioration of rock mechanical parameters caused by dry‒wet cycles.The model proposed considers the change in the friction angle of the joint surface with the shear displacement,which is applied to the derivation of the model by introducing the dynamic evolutionary friction angle parameter.The reasonably good agreement between a predicted curve and the corresponding experimental curve indicates that this method can effectively predict the shear strength of a bolted rock joint involving rough joint under dryewet cycling conditions.展开更多
High-entropy alloys(HEAs)possess outstanding features such as corrosion resistance,irradiation resistance,and good mechan-ical properties.A few HEAs have found applications in the fields of aerospace and defense.Exten...High-entropy alloys(HEAs)possess outstanding features such as corrosion resistance,irradiation resistance,and good mechan-ical properties.A few HEAs have found applications in the fields of aerospace and defense.Extensive studies on the deformation mech-anisms of HEAs can guide microstructure control and toughness design,which is vital for understanding and studying state-of-the-art structural materials.Synchrotron X-ray and neutron diffraction are necessary techniques for materials science research,especially for in situ coupling of physical/chemical fields and for resolving macro/microcrystallographic information on materials.Recently,several re-searchers have applied synchrotron X-ray and neutron diffraction methods to study the deformation mechanisms,phase transformations,stress behaviors,and in situ processes of HEAs,such as variable-temperature,high-pressure,and hydrogenation processes.In this review,the principles and development of synchrotron X-ray and neutron diffraction are presented,and their applications in the deformation mechanisms of HEAs are discussed.The factors that influence the deformation mechanisms of HEAs are also outlined.This review fo-cuses on the microstructures and micromechanical behaviors during tension/compression or creep/fatigue deformation and the application of synchrotron X-ray and neutron diffraction methods to the characterization of dislocations,stacking faults,twins,phases,and intergrain/interphase stress changes.Perspectives on future developments of synchrotron X-ray and neutron diffraction and on research directions on the deformation mechanisms of novel metals are discussed.展开更多
Proper regulation of synapse formation and elimination is critical for establishing mature neuronal circuits and maintaining brain function.Synaptic abnormalities,such as defects in the density and morphology of posts...Proper regulation of synapse formation and elimination is critical for establishing mature neuronal circuits and maintaining brain function.Synaptic abnormalities,such as defects in the density and morphology of postsynaptic dendritic spines,underlie the pathology of various neuropsychiatric disorders.Protocadherin 17(PCDH17)is associated with major mood disorders,including bipolar disorder and depression.However,the molecular mechanisms by which PCDH17 regulates spine number,morphology,and behavior remain elusive.In this study,we found that PCDH17 functions at postsynaptic sites,restricting the number and size of dendritic spines in excitatory neurons.Selective overexpression of PCDH17 in the ventral hippocampal CA1 results in spine loss and anxiety-and depression-like behaviors in mice.Mechanistically,PCDH17 interacts with actin-relevant proteins and regulates actin filament(F-actin)organization.Specifically,PCDH17 binds to ROCK2,increasing its expression and subsequently enhancing the activity of downstream targets such as LIMK1 and the phosphorylation of cofilin serine-3(Ser3).Inhibition of ROCK2 activity with belumosudil(KD025)ameliorates the defective F-actin organization and spine structure induced by PCDH17 overexpression,suggesting that ROCK2 mediates the effects of PCDH17 on F-actin content and spine development.Hence,these findings reveal a novel mechanism by which PCDH17 regulates synapse development and behavior,providing pathological insights into the neurobiological basis of mood disorders.展开更多
The snap-through behaviors and nonlinear vibrations are investigated for a bistable composite laminated cantilever shell subjected to transversal foundation excitation based on experimental and theoretical approaches....The snap-through behaviors and nonlinear vibrations are investigated for a bistable composite laminated cantilever shell subjected to transversal foundation excitation based on experimental and theoretical approaches.An improved experimental specimen is designed in order to satisfy the cantilever support boundary condition,which is composed of an asymmetric region and a symmetric region.The symmetric region of the experimental specimen is entirely clamped,which is rigidly connected to an electromagnetic shaker,while the asymmetric region remains free of constraint.Different motion paths are realized for the bistable cantilever shell by changing the input signal levels of the electromagnetic shaker,and the displacement responses of the shell are collected by the laser displacement sensors.The numerical simulation is conducted based on the established theoretical model of the bistable composite laminated cantilever shell,and an off-axis three-dimensional dynamic snap-through domain is obtained.The numerical solutions are in good agreement with the experimental results.The nonlinear stiffness characteristics,dynamic snap-through domain,and chaos and bifurcation behaviors of the shell are quantitatively analyzed.Due to the asymmetry of the boundary condition and the shell,the upper stable-state of the shell exhibits an obvious soft spring stiffness characteristic,and the lower stable-state shows a linear stiffness characteristic of the shell.展开更多
In this editorial,I comment on the article“Association of preschool children behavior and emotional problems with the parenting behavior of both parents”which was published in the latest issue of“World Journal of C...In this editorial,I comment on the article“Association of preschool children behavior and emotional problems with the parenting behavior of both parents”which was published in the latest issue of“World Journal of Clinical Cases”that demonstrates the prevalence of behavioral disorders in preschool children.Therefore I am focused on parenting which is the most effective factor shown to affect the development and continuity of these behaviors.The management of child behavior problems is crucial.Children in early ages,especially preschoolers who are in the first 5 years of life,are influenced by dramatic changes in various aspects of development,such as social,emotional,and physical.Also,children experience many changes linked to different developmental tasks,such as discovering themselves,getting new friendships,and adapting to a new environment.In this period,parents have a critical role in supporting child development.If parents do not manage and overcome their child’s misbehavior,it could be transformed into psychosocial problems in adulthood.Parenting is the most powerful predictor in the social development of preschool children.Several studies have shown that to reduce the child’s emotional and behavioral problems,a warm relationship between parents and children is needed.In addition,recent studies have demonstrated significant relationships between family regulation factors and parenting,as well as with child behaviors.展开更多
Polymer-blend geocell sheets(PBGS)have been developed as substitute materials for manufacturing geocells.Various attempts have been made to test and predict the behaviors of commonly used geogrids,geotextiles,geomembr...Polymer-blend geocell sheets(PBGS)have been developed as substitute materials for manufacturing geocells.Various attempts have been made to test and predict the behaviors of commonly used geogrids,geotextiles,geomembranes,and geocells.However,the elastic-viscoplastic behaviors of novel-developed geocell sheets are still poorly understood.Therefore,this paper investigates the elastic-viscoplastic behaviors of PBGS to gain a comprehensive understanding of their mechanical properties.Furthermore,the tensile load-strain history under various loading conditions is simulated by numerical calculation for widespread utilization.To achieve this goal,monotonic loading tests,short-term creep and stress relaxation tests,and multi-load-path tests(also known as arbitrary loading history tests)are performed using a universal testing machine.The results are simulated using the nonlinear three-component(NLTC)model,which consists of three nonlinear components,i.e.a hypo-elastic component,a nonlinear inviscid component,and a nonlinear viscid component.The experimental and numerical results demonstrate that PBGS exhibit significant elastic-viscoplastic behavior that can be accurately predicted by the NLTC model.Moreover,the tensile strain rates significantly influence the tensile load,with higher strain rates resulting in increased tensile loads and more linear load-strain curves.Also,parametric analysis of the rheological characteristics reveals that the initial tensile strain rates have negligible impact on the results.The rate-sensitivity coefficient of PBGS is approximately 0.163,which falls within the typical range observed in most geosynthetics.展开更多
The Ti-5Al-2Sn-4Zr-4Mo-2Cr-1Fe(β-CEZ)alloy is considered as a potential structural material in the aviation industry due to its outstanding strength and corrosion resistance.Electrochemical machining(ECM)is an effici...The Ti-5Al-2Sn-4Zr-4Mo-2Cr-1Fe(β-CEZ)alloy is considered as a potential structural material in the aviation industry due to its outstanding strength and corrosion resistance.Electrochemical machining(ECM)is an efficient and low-cost technology for manufacturing theβ-CEZ alloy.In ECM,the machining parameter selection and tool design are based on the electrochemical dissolution behavior of the materials.In this study,the electrochemical dissolution behaviors of theβ-CEZ and Ti-6Al-4V(TC4)alloys in NaNO3solution are discussed.The open circuit potential(OCP),Tafel polarization,potentiodynamic polarization,electrochemical impedance spectroscopy(EIS),and current efficiency curves of theβ-CEZ and TC4 alloys are analyzed.The results show that,compared to the TC4 alloy,the passivation film structure is denser and the charge transfer resistance in the dissolution process is greater for theβ-CEZ alloy.Moreover,the dissolved surface morphology of the two titanium-based alloys under different current densities are analyzed.Under low current densities,theβ-CEZ alloy surface comprises dissolution pits and dissolved products,while the TC4 alloy surface comprises a porous honeycomb structure.Under high current densities,the surface waviness of both the alloys improves and the TC4 alloy surface is flatter and smoother than theβ-CEZ alloy surface.Finally,the electrochemical dissolution models ofβ-CEZ and TC4 alloys are proposed.展开更多
BACKGROUND The comprehension and utilization of timing theory and behavior change can offer a more extensive and individualized provision of support and treatment alternatives for primipara.This has the potential to e...BACKGROUND The comprehension and utilization of timing theory and behavior change can offer a more extensive and individualized provision of support and treatment alternatives for primipara.This has the potential to enhance the psychological well-being and overall quality of life for primipara,while also furnishing healthcare providers with efficacious interventions to tackle the psychological and physiological obstacles encountered during the stages of pregnancy and postpartum.AIM To explore the effect of timing theory combined with behavior change on selfefficacy,negative emotions and quality of life in patients with primipara.METHODS A total of 80 primipara cases were selected and admitted to our hospital between August 2020 and May 2022.These cases were divided into two groups,namely the observation group and the control group,with 40 cases in each group.The nursing interventions differed between the two groups,with the control group receiving routine nursing and the observation group receiving integrated nursing based on the timing theory and behavior change.The study aimed to compare the pre-and post-nursing scores of Chinese Perceived Stress Scale(CPSS),Edinburgh Postpartum Depression Scale(EPDS),Self-rating Anxiety Scale(SAS),breast milk knowledge,self-efficacy,and SF-36 quality of life in both groups.RESULTS After nursing,the CPSS,EPDS,and SAS scores of the two groups was significantly lower than that before nursing,and the CPSS,EPDS,and SAS scores of the observation group was significantly lower than that of the control group(P=0.002,P=0.011,and P=0.001 respectively).After nursing,the breastfeeding knowledge mastery,selfefficacy,and SF-36 quality of life scores was significantly higher than that before nursing,and the breastfeeding knowledge mastery(P=0.013),self-efficacy(P=0.008),and SF-36 quality of life(P=0.011)scores of the observation group was significantly higher than that of the control group.CONCLUSION The integration of timing theory and behavior change integrated theory has been found to be an effective approach in alleviating negative mood and stress experienced by primipara individuals,while also enhancing their selfefficacy and overall quality of life.This study focuses on the key concepts of timing theory,behavior change,primipara individuals,negative mood,and quality of life.展开更多
The collapse pressure is a key parameter when RTPs are applied in harsh deep-water environments.To investigate the collapse of RTPs,numerical simulations and hydrostatic pressure tests are conducted.For the numerical ...The collapse pressure is a key parameter when RTPs are applied in harsh deep-water environments.To investigate the collapse of RTPs,numerical simulations and hydrostatic pressure tests are conducted.For the numerical simulations,the eigenvalue analysis and Riks analysis are combined,in which the Hashin failure criterion and fracture energy stiffness degradation model are used to simulate the progressive failure of composites,and the“infinite”boundary conditions are applied to eliminate the boundary effects.As for the hydrostatic pressure tests,RTP specimens were placed in a hydrostatic chamber after filled with water.It has been observed that the cross-section of the middle part collapses when it reaches the maximum pressure.The collapse pressure obtained from the numerical simulations agrees well with that in the experiment.Meanwhile,the applicability of NASA SP-8007 formula on the collapse pressure prediction was also discussed.It has a relatively greater difference because of the ignorance of the progressive failure of composites.For the parametric study,it is found that RTPs have much higher first-ply-failure pressure when the winding angles are between 50°and 70°.Besides,the effect of debonding and initial ovality,and the contribution of the liner and coating are also discussed.展开更多
Distraction spinal cord injury is caused by some degree of distraction or longitudinal tension on the spinal cord and commonly occurs in patients who undergo corrective operation for severe spinal deformity.With the i...Distraction spinal cord injury is caused by some degree of distraction or longitudinal tension on the spinal cord and commonly occurs in patients who undergo corrective operation for severe spinal deformity.With the increased degree and duration of distraction,spinal cord injuries become more serious in terms of their neurophysiology,histology,and behavior.Very few studies have been published on the specific characteristics of distraction spinal cord injury.In this study,we systematically review 22 related studies involving animal models of distraction spinal cord injury,focusing particularly on the neurophysiological,histological,and behavioral characteristics of this disease.In addition,we summarize the mechanisms underlying primary and secondary injuries caused by distraction spinal cord injury and clarify the effects of different degrees and durations of distraction on the primary injuries associated with spinal cord injury.We provide new concepts for the establishment of a model of distraction spinal cord injury and related basic research,and provide reference guidelines for the clinical diagnosis and treatment of this disease.展开更多
The safety valve is an important component to ensure the safe operation of lithium-ion batteries(LIBs).However,the effect of safety valve type on the thermal runaway(TR)and gas venting behavior of LIBs,as well as the ...The safety valve is an important component to ensure the safe operation of lithium-ion batteries(LIBs).However,the effect of safety valve type on the thermal runaway(TR)and gas venting behavior of LIBs,as well as the TR hazard severity of LIBs,are not known.In this paper,the TR and gas venting behavior of three 100 A h lithium iron phosphate(LFP)batteries with different safety valves are investigated under overheating.Compared to previous studies,the main contribution of this work is in studying and evaluating the effect of gas venting behavior and TR hazard severity of LFP batteries with three safety valve types.Two significant results are obtained:(Ⅰ)the safety valve type dominates over gas venting pressure of battery during safety venting,the maximum gas venting pressure of LFP batteries with a round safety valve is 3320 Pa,which is one order of magnitude higher than other batteries with oval or cavity safety valve;(Ⅱ)the LFP battery with oval safety valve has the lowest TR hazard as shown by the TR hazard assessment model based on gray-fuzzy analytic hierarchy process.This study reveals the effect of safety valve type on TR and gas venting,providing a clear direction for the safety valve design.展开更多
基金supported by grants from the National Natural Science Foundation of China(No.82160311,No.82160225 and No.82060232)the Science and Technology Fund Project of Guizhou Health and Health Commission(No.gzwkj2021-356)+1 种基金Basic Science Technology Project of Guizhou Province[No.ZK(2021)412]the Special Project of Academic New Seedling Cultivation and Free Exploration Innovation-Post-project subsidy of the National Natural Science Foundation of China,“Thousand Levels”of Guizhou Province High Level Innovative Talents(No.gzwjrs 2023-012).
文摘Objective Long noncoding RNAs(lncRNAs)and microRNAs(miRNAs)are widely expressed in the brain and are associated with the development of neurological and neurodegenerative diseases.However,their roles and molecular mechanisms in major depressive disorder(MDD)remain largely unknown.This study aimed to identify lncRNAs and miRNAs involved in the development of MDD and elucidate their molecular mechanisms.Methods Transcriptome and bioinformatic analyses were performed to identify miRNAs and lncRNAs related to MDD.C57 mice were subjected to chronic unpredictable mild stress(CUMS)to establish a depression model.Lentiviruses containing either lncRNA NPTN-IT1-201 or miR-142-5p were microinjected into the hippocampal region of these mice.Behavioral tests including the sucrose preference test(SPT),tail suspension test(TST),and forced swim test(FST)were conducted to evaluate depressive-like behaviors.Results The results revealed that overexpression of lncRNA NPTN-IT1-201 or inhibition of miR-142-5p significantly ameliorated depressive-like behaviors in CUMS-treated mice.Dual-luciferase reporter assays confirmed interactions between miR-142-5p with both brain-derived neurotrophic factor(BDNF)and NPTN-IT1-201.ELISA analysis revealed significant alterations in relevant biomarkers in the blood samples of MDD patients compared to healthy controls.Histological analyses,including HE and Nissl staining,showed marked structural changes in brain tissues following CUMS treatment,which were partially reversed by lncRNA NPTN-IT1-201 overexpression or miR-142-5p inhibition.Immunofluorescence imaging demonstrated significant differences in the levels of BAX,Bcl2,p65,Iba1 among different treatment groups.TUNEL assays confirmed reduced apoptosis in brain tissues following these interventions.Western blotting showed the significant differences in BDNF,BAX,and Bcl2 protein levels among different treatment groups.Conclusion NPTN-IT1-201 regulates inflammation and apoptosis in MDD by targeting BDNF via miR-142-5p,making it a potential therapeutic target for MDD.
文摘Low salt intake is associated with depression, but the experimental evidence is not clear. Sixty adult mice were randomly divided into four groups (mild, moderate and severe salt deficiency groups and control) during the seasonal splitting from winter to spring. The mice in the control group were fed with standard ordinary diet (salt content 0.26%), while in the mild, moderate and severe groups, the mice were fed with 10%, 30% and 50% salt deficient feedstuff, lasting for approximately 3 months. The results showed that the salt content of feed was negatively correlated with the food intake and body weight of mice. The sucrose preference test found that only the mild salt deficiency group had no differ-ence between the beginning and the end of the experiment, and the other three groups in-cluding the control, showed a significant decrease. These results suggest that dietary salt content has an impact on the food intake and body weight of mice and is associated with the emergence of depressive-like behavior. Furthermore, the seasonal splitting from winter to spring may also have a differential synergistic effect on the change of depression-like behavior associated with low salt intake in mice.
文摘The main objective of this work was to 1) study the influence of endogenous melatonin (Mel) abolishment via pinealectomy and 2) explore exogenous Mel effect on anxiety-like and depressive-like behavior in male and female rats. Rats were shamoperated (Sh) or pinealectomized (Px) and following subgroups were selected 1) Px/NaCl (0.9%) and Sh/NaCl (0.9%) : rats injected subcutaneously, once daily for 8 weeks, with saline solution NaCl (0.9%) as vehicle;2) Px/Mel (4 mg/Kg) and Sh/Mel (4 mg/Kg): Rats similarly injected with 4 mg/Kg of Mel. All animals were housed under a photoperiod of (LD:16/8). After different treatments animals were tested in the open-field test (OFT), elevated plus maze test (EPM) to determine anxiety-like behavior, and forced swimming test (FST) to evaluate depressive-like level. Our results revealed that level of anxiety-like and depressive-like behavior are significantly higher in Px/NaCl (0.9%) when compared to Sh/NaCl (0.9%) group, suggesting that pinelectomy induced an anxiogenic and depressant effects. The Px effects would be due to the absence of endogenous Mel synthesis and release. Additionally, we clearly demonstrated that the level of anxiety-like and depressive-like behavior are higher in Px/Mel (4 mg/Kg) and Sh/Mel when compared respectively to Px/NaCl (4 mg/Kg) and Sh/NaCl groups suggesting an anxiolytic and antidepressant effects of exogenous Mel. Behavioral responses were sex dependent since the difference between females and males, especially, after melatonin administration, were statistically significant. These experiments provide evidence that pinealectomy and Mel regulated emotionally behavior in male and female rats.
文摘Aim To investigate the mechanisms underlying depressive-like behavior induced by chronic cerebral is- chemia in rats. Methods In the present study, a chronic cerebral hypoperfusion model was established by perma- 2VO) in rats. Two weeks after 2VO, GAB- nent bilateral common carotid arteries occlusion (two-vessel occlusion, AB receptor agonist baclofen (25 mg · kg^-1 . d^-1 i p ) was administrated for 21 days. The FST was performed to evaluate depressive-like behavior in which the immobility time was recorded. In addition, the expression of brain derived neurotrophic factor (BDNF) in hippocampal CA1 was measured by Western blot. Results The immobility time of 2VO group was significantly prolonged and the expression of BDNF was decreased by 28.95% compared with sham group. After activation of GABAB receptors by baclofen, the immobility time was significantly reduced and the expression of BDNF was increased by 47.91% compared with 2VO group. Conclusion 2VO induced ob- vious depressive-like behavior in rats. Activation of GABAB receptors alleviates the depressive-like behavior in- duced by chronic cerebral ischemia via upredulation of BDNF in hippocampal CA1 in rats.
文摘OBJECTIVEα-Dstroglycan(α-DG)is a predominant component in the dystrophin-glycoprotein complex(DGC)and a recently char⁃acterized receptor for several extracellular matrix components with high affinity.Recent research⁃es have reported that hypoglycosylation ofα-DG is associated with the pathophysiology of diseas⁃es,especially muscular dystrophy,but little is known about major depressive disorder(MDD).Like-acetylglucosaminyl transferase(Large)is a key enzyme for glycosylation ofα-DG,which mainly modifies two points in the middle domain ofα-DG:Thr-317 and Thr-319.Glycosylatedα-DG(GLY-α-DG)can bind with high affinity to extracellular matrix(ECM)molecules that con⁃tain laminin globular(LG)domains,including per⁃lecan,agrin and neurexin.Agrin is mainly derived from neurons rather than glial cells.In cultured hippocampal neurons,it was found that agrin could regulate the homeostatic plasticity of inhibi⁃tory neurons by acting on GLY-α-DG.Mdx mice are transgenetic models for the investigation of Duchenne muscular dystrophy.Many studies have shown that the expression of GLY-α-DG in the peripheral and brain tissues of Mdx mice is significantly down-regulated.Mdx mice show cognitive impairment and high levels of anxiety.In this study,we employed chronic social defeat stress(CSDS)to establish an animal model of depression and detected the expression of GLY-α-DG among the brain areas associated with the pathophysiology of depression.METHODS So⁃cial interaction test(SIT)and sucrose preference test(SPT)were used to evaluate depressive-like behavior.Open field(OF)and elevated plus maze(EPM)test were used to determine the anxiety-like behavior of Mdx mice.Novelty-sup⁃pressed feeding test(NSFT)forced swim test(FST)and tail suspension test(TST)were used to detect the depressive-like behavior of Mdx mice.Novel object recognition test(NOR)was applied to evaluate the cognition of Mdx mice.Subthreshold social defeat stress was used to explore the susceptibility to stress in Mdx mice.Stereotactic infusion of agrin into the ventral hippocampus(vHip),FST and TST were used to investigate the antidepressant effects of agrin.Adeno-associated virus(AAV)-mediated overex⁃pression techniques,behavior tests and whole-cell path-clamp technique were conducted to determine the impact of Large overexpression on CSDS susceptible mice.RESULTS The expres⁃sion ofα-DG and GLY-α-DG were significantly decreased in the vHip of CSDS susceptible mice.Mdx mice showed decreased expression of GLY-α-DG and increased anxiety-like behav⁃iors.Mdx mice displayed some depressive-like behaviors,and the susceptibility to stress was significantly increased.Downregulation of the expressionα-DG in the vHip by lentivirus increased the susceptibility to stress.Administra⁃tion of agrin to CSDS susceptible mice exerted antidepressant effects,and this effect could par⁃tially sustain for a week.The expression of Large was decreased in vHip.Overexpression of Large through AAV-Large reversed the depressive-like behaviors and restored the decreased frequency and amplitude of mIPSC.CONCLUSION GLY-α-DG and its glycosylase are significantly decreased in CSDS susceptible mice.Adminis⁃tration of agrin and overexpression of Large displays antidepressant effect,which may be related to its promotion of inhibitory synaptic transmission.
文摘OBJECTIVE Alcohol dependence is not only the most common public health prob⁃lem worldwide,but also the cause of many alco⁃hol-related diseases,such as anxiety and depres⁃sion.However,the mechanism of these comor⁃bidities is not clear.Recently,the role of phos⁃phodiesterases(PDEs)in anxiety-and depres⁃sion-like behavior induced by alcohol withdrawal has received increasing attentions.PDEs are a superfamily of enzymes that catalyze the hydroly⁃sis of intracellular cyclic AMP(cAMP)and(or)cyclic GMP(cGMP).There are 11 families(PDE1-PDE11),each of which has 1 to 4 sub⁃types encoded by different genes.In the present study,we identified the key PDEs involved in anxiety-and depression-like behavior induced by alcohol withdrawal.METHODS After withdrawal from short-term or chronic intermittent ethanol vapor exposure(STEVE and CIEVE,respectively),adult male C57BL/6J(B6)mice were tested for anxiety-and depression-like behavior using the sucrose preference,open field,elevated plus-maze,tail suspension,forced swimming,hole board and light-dark tests.In addition,the expression of PDE subtypes(PDE2,PDE4,and PDE7)in the hippocampus,amygdala,and stria⁃tum,which are considered as anxiety-and(or)depression-related brain regions,was detected by Western blotting.RESULTS①Differences in anxiety-and depression-like behaviors between STEVE and CIEVE mice.Compared to STEVE mice,CIEVE mice showed greater anxiety-and depression-like behavior in the tests described above.②The expression of PDE2,PDE4 and PDE7 in the anxiety-and depression-related brain regions of CIEVE mice.Compared to the STEVE mice,CIEVE mice showed significant higher expression of PDE4A and PDE7A in the hippo⁃campus(P<0.05)and PDE4D and PDE7A in the amygdala(P<0.05).However,the expres⁃sion of PDE2A,PDE4B,PDE4D and PDE7B in the hippocampus,PDE2A,PDE4A,PDE4B and PDE7B in the amygdala,PDE2A,PDE4A,PDE4B,PDE4D,PDE7A and PDE7B in the striatum was not significantly changed.CONCLUSION The model of CIEVE showed significant anxiety-and depression-like behavior,with concurrent increases in the expression of PDE4A and PDE7A in the hippocampus and PDE4D and PDE7A in the amygdala.These results suggest that PDE4A,PDE4D,and DE7A may play an important role in the regulation of anxiety-and depression-like behavior induced by alcohol withdrawal.
基金supported by the following funds:National Natural Science Foundation of China(51935014,52165043)Jiangxi Provincial Cultivation Program for Academic and Technical Leaders of Major Subjects(20225BCJ23008)+1 种基金Jiangxi Provincial Natural Science Foundation(20224ACB204013,20224ACB214008)Scientific Research Project of Anhui Universities(KJ2021A1106)。
文摘Magnesium(Mg)alloys are considered to be a new generation of revolutionary medical metals.Laser-beam powder bed fusion(PBF-LB)is suitable for fabricating metal implants withpersonalized and complicated structures.However,the as-built part usually exhibits undesirable microstructure and unsatisfactory performance.In this work,WE43 parts were firstly fabricated by PBF-LB and then subjected to heat treatment.Although a high densification rate of 99.91%was achieved using suitable processes,the as-built parts exhibited anisotropic and layeredmicrostructure with heterogeneously precipitated Nd-rich intermetallic.After heat treatment,fine and nano-scaled Mg24Y5particles were precipitated.Meanwhile,theα-Mg grainsunderwent recrystallization and turned coarsened slightly,which effectively weakened thetexture intensity and reduced the anisotropy.As a consequence,the yield strength and ultimate tensile strength were significantly improved to(250.2±3.5)MPa and(312±3.7)MPa,respectively,while the elongation was still maintained at a high level of 15.2%.Furthermore,the homogenized microstructure reduced the tendency of localized corrosion and favoredthe development of uniform passivation film.Thus,the degradation rate of WE43 parts was decreased by an order of magnitude.Besides,in-vitro cell experiments proved their favorable biocompatibility.
基金supported by the National Natural Science Foundation of China(82171170,81971076,82371277 to H.Z.,82101345 to L.R.L.)。
文摘A growing number of studies have demonstrated that repeated exposure to sevoflurane during development results in persistent social abnormalities and cognitive impairment.Davunetide,an active fragment of the activity-dependent neuroprotective protein(ADNP),has been implicated in social and cognitive protection.However,the potential of davunetide to attenuate social deficits following sevoflurane exposure and the underlying developmental mechanisms remain poorly understood.In this study,ribosome and proteome profiles were analyzed to investigate the molecular basis of sevoflurane-induced social deficits in neonatal mice.The neuropathological basis was also explored using Golgi staining,morphological analysis,western blotting,electrophysiological analysis,and behavioral analysis.Results indicated that ADNP was significantly down-regulated following developmental exposure to sevoflurane.In adulthood,anterior cingulate cortex(ACC)neurons exposed to sevoflurane exhibited a decrease in dendrite number,total dendrite length,and spine density.Furthermore,the expression levels of Homer,PSD95,synaptophysin,and vglut2 were significantly reduced in the sevoflurane group.Patch-clamp recordings indicated reductions in both the frequency and amplitude of miniature excitatory postsynaptic currents(mEPSCs).Notably,davunetide significantly ameliorated the synaptic defects,social behavior deficits,and cognitive impairments induced by sevoflurane.Mechanistic analysis revealed that loss of ADNP led to dysregulation of Ca^(2+)activity via the Wnt/β-catenin signaling,resulting in decreased expression of synaptic proteins.Suppression of Wnt signaling was restored in the davunetide-treated group.Thus,ADNP was identified as a promising therapeutic target for the prevention and treatment of neurodevelopmental toxicity caused by general anesthetics.This study provides important insights into the mechanisms underlying social and cognitive disturbances caused by sevoflurane exposure in neonatal mice and elucidates the regulatory pathways involved.
基金Supported by the National Natural Science Foundation of China,No.81330068.
文摘BACKGROUND Parental behaviors are key in shaping children’s psychological and behavioral development,crucial for early identification and prevention of mental health issues,reducing psychological trauma in childhood.AIM To investigate the relationship between parenting behaviors and behavioral and emotional issues in preschool children.METHODS From October 2017 to May 2018,7 kindergartens in Ma’anshan City were selected to conduct a parent self-filled questionnaire-Health Development Survey of Preschool Children.Children’s Strength and Difficulties Questionnaire(Parent Version)was applied to measures the children’s behavioral and emotional performance.Parenting behavior was evaluated using the Parental Behavior Inventory.Binomial logistic regression model was used to analyze the association between the detection rate of preschool children’s behavior and emotional problems and their parenting behaviors.RESULTS High level of parental support/participation was negatively correlated with conduct problems,abnormal hyperactivity,abnormal total difficulty scores and abnormal prosocial behavior problems.High level of maternal support/participation was negatively correlated with abnormal emotional symptoms and abnormal peer interaction in children.High level of parental hostility/coercion was positively correlated with abnormal emotional symptoms,abnormal conduct problems,abnormal hyperactivity,abnormal peer interaction,and abnormal total difficulty scores in children(all P<0.05).Moreover,paternal parenting behaviors had similarly effects on behavior and emotional problems of preschool children compared with maternal parenting behaviors(all P>0.05),after calculating ratio of odds ratio values.CONCLUSION Our study found that parenting behaviors are associated with behavioral and emotional issues in preschool children.Overall,the more supportive or involved the parents are,the fewer behavioral and emotional problems the children experience;conversely,the more hostile or controlling the parents are,the more behavioral and emotional problems the children face.Moreover,the impact of fathers’parenting behaviors on preschool children’s behavior and emotions is no less significant than that of mothers’parenting behaviors.
基金the Natural Science Foundation of China(Grant Nos.42302314 and 52078427)the Open foundation of State Key Laboratory of Geohazard Prevention and Geoenvironment Protection(Grant No.SKLGP2022K001).
文摘A series of direct shear tests under constant normal loading conditions were carried out on specimens of bolted sandstone single-joint treated with different numbers of dryewet cycles.The experimental results show that the peak shear strength and shear stiffness of bolted sandstone joints were significantly reduced after 12 dryewet cycles.The decrease in the shear strength of rough joints is more significant than that of flat joints.Due to the decrease in the strength of the surrounding rock,the deformation characteristics of the bolts are significantly affected by the number of dryewet cycles performed.With an increase in the number of dryewet cycles,the plastic hinge length of the bolt gradually increases,resulting in an increase in the corresponding shear displacement when the bolt breaks.Compared with the tensileeshear failure mode of the bolts in flat joints,the tensileebending failure mode arises for bolts in rough joints.A shear curve model describing the whole process of bolted rock joints is established based on the deterioration of rock mechanical parameters caused by dry‒wet cycles.The model proposed considers the change in the friction angle of the joint surface with the shear displacement,which is applied to the derivation of the model by introducing the dynamic evolutionary friction angle parameter.The reasonably good agreement between a predicted curve and the corresponding experimental curve indicates that this method can effectively predict the shear strength of a bolted rock joint involving rough joint under dryewet cycling conditions.
基金supported by the National Natural Science Foundation of China(Nos.52171098 and 51921001)the State Key Laboratory for Advanced Metals and Materials(No.2022Z-02)+1 种基金the National High-level Personnel of Special Support Program(No.ZYZZ2021001)the Fundamental Research Funds for the Central Universities(Nos.FRF-TP-20-03C2 and FRF-BD-20-02B).
文摘High-entropy alloys(HEAs)possess outstanding features such as corrosion resistance,irradiation resistance,and good mechan-ical properties.A few HEAs have found applications in the fields of aerospace and defense.Extensive studies on the deformation mech-anisms of HEAs can guide microstructure control and toughness design,which is vital for understanding and studying state-of-the-art structural materials.Synchrotron X-ray and neutron diffraction are necessary techniques for materials science research,especially for in situ coupling of physical/chemical fields and for resolving macro/microcrystallographic information on materials.Recently,several re-searchers have applied synchrotron X-ray and neutron diffraction methods to study the deformation mechanisms,phase transformations,stress behaviors,and in situ processes of HEAs,such as variable-temperature,high-pressure,and hydrogenation processes.In this review,the principles and development of synchrotron X-ray and neutron diffraction are presented,and their applications in the deformation mechanisms of HEAs are discussed.The factors that influence the deformation mechanisms of HEAs are also outlined.This review fo-cuses on the microstructures and micromechanical behaviors during tension/compression or creep/fatigue deformation and the application of synchrotron X-ray and neutron diffraction methods to the characterization of dislocations,stacking faults,twins,phases,and intergrain/interphase stress changes.Perspectives on future developments of synchrotron X-ray and neutron diffraction and on research directions on the deformation mechanisms of novel metals are discussed.
基金supported by the National Natural Science Foundation of China(82171506 and 31872778)Discipline Innovative Engineering Plan(111 Program)of China(B13036)+3 种基金Key Laboratory Grant from Hunan Province(2016TP1006)Department of Science and Technology of Hunan Province(2021DK2001,Innovative Team Program 2019RS1010)Innovation-Driven Team Project from Central South University(2020CX016)Hunan Hundred Talents Program for Young Outstanding Scientists。
文摘Proper regulation of synapse formation and elimination is critical for establishing mature neuronal circuits and maintaining brain function.Synaptic abnormalities,such as defects in the density and morphology of postsynaptic dendritic spines,underlie the pathology of various neuropsychiatric disorders.Protocadherin 17(PCDH17)is associated with major mood disorders,including bipolar disorder and depression.However,the molecular mechanisms by which PCDH17 regulates spine number,morphology,and behavior remain elusive.In this study,we found that PCDH17 functions at postsynaptic sites,restricting the number and size of dendritic spines in excitatory neurons.Selective overexpression of PCDH17 in the ventral hippocampal CA1 results in spine loss and anxiety-and depression-like behaviors in mice.Mechanistically,PCDH17 interacts with actin-relevant proteins and regulates actin filament(F-actin)organization.Specifically,PCDH17 binds to ROCK2,increasing its expression and subsequently enhancing the activity of downstream targets such as LIMK1 and the phosphorylation of cofilin serine-3(Ser3).Inhibition of ROCK2 activity with belumosudil(KD025)ameliorates the defective F-actin organization and spine structure induced by PCDH17 overexpression,suggesting that ROCK2 mediates the effects of PCDH17 on F-actin content and spine development.Hence,these findings reveal a novel mechanism by which PCDH17 regulates synapse development and behavior,providing pathological insights into the neurobiological basis of mood disorders.
基金Project supported by the National Natural Science Foundation of China(Nos.11832002 and 12072201)。
文摘The snap-through behaviors and nonlinear vibrations are investigated for a bistable composite laminated cantilever shell subjected to transversal foundation excitation based on experimental and theoretical approaches.An improved experimental specimen is designed in order to satisfy the cantilever support boundary condition,which is composed of an asymmetric region and a symmetric region.The symmetric region of the experimental specimen is entirely clamped,which is rigidly connected to an electromagnetic shaker,while the asymmetric region remains free of constraint.Different motion paths are realized for the bistable cantilever shell by changing the input signal levels of the electromagnetic shaker,and the displacement responses of the shell are collected by the laser displacement sensors.The numerical simulation is conducted based on the established theoretical model of the bistable composite laminated cantilever shell,and an off-axis three-dimensional dynamic snap-through domain is obtained.The numerical solutions are in good agreement with the experimental results.The nonlinear stiffness characteristics,dynamic snap-through domain,and chaos and bifurcation behaviors of the shell are quantitatively analyzed.Due to the asymmetry of the boundary condition and the shell,the upper stable-state of the shell exhibits an obvious soft spring stiffness characteristic,and the lower stable-state shows a linear stiffness characteristic of the shell.
基金the main study who are focused on parenting style and preschoolers'behavioral problems and give an opportunity to me to comment on this issue.
文摘In this editorial,I comment on the article“Association of preschool children behavior and emotional problems with the parenting behavior of both parents”which was published in the latest issue of“World Journal of Clinical Cases”that demonstrates the prevalence of behavioral disorders in preschool children.Therefore I am focused on parenting which is the most effective factor shown to affect the development and continuity of these behaviors.The management of child behavior problems is crucial.Children in early ages,especially preschoolers who are in the first 5 years of life,are influenced by dramatic changes in various aspects of development,such as social,emotional,and physical.Also,children experience many changes linked to different developmental tasks,such as discovering themselves,getting new friendships,and adapting to a new environment.In this period,parents have a critical role in supporting child development.If parents do not manage and overcome their child’s misbehavior,it could be transformed into psychosocial problems in adulthood.Parenting is the most powerful predictor in the social development of preschool children.Several studies have shown that to reduce the child’s emotional and behavioral problems,a warm relationship between parents and children is needed.In addition,recent studies have demonstrated significant relationships between family regulation factors and parenting,as well as with child behaviors.
基金supported by the National Natural Science Foundation of China(Grant Nos.42077262 and 42077261)the Research Fund Project of Xinjiang Transportation Planning Survey and Design Institute Co.,Ltd.(Grant No.KY2022042504).
文摘Polymer-blend geocell sheets(PBGS)have been developed as substitute materials for manufacturing geocells.Various attempts have been made to test and predict the behaviors of commonly used geogrids,geotextiles,geomembranes,and geocells.However,the elastic-viscoplastic behaviors of novel-developed geocell sheets are still poorly understood.Therefore,this paper investigates the elastic-viscoplastic behaviors of PBGS to gain a comprehensive understanding of their mechanical properties.Furthermore,the tensile load-strain history under various loading conditions is simulated by numerical calculation for widespread utilization.To achieve this goal,monotonic loading tests,short-term creep and stress relaxation tests,and multi-load-path tests(also known as arbitrary loading history tests)are performed using a universal testing machine.The results are simulated using the nonlinear three-component(NLTC)model,which consists of three nonlinear components,i.e.a hypo-elastic component,a nonlinear inviscid component,and a nonlinear viscid component.The experimental and numerical results demonstrate that PBGS exhibit significant elastic-viscoplastic behavior that can be accurately predicted by the NLTC model.Moreover,the tensile strain rates significantly influence the tensile load,with higher strain rates resulting in increased tensile loads and more linear load-strain curves.Also,parametric analysis of the rheological characteristics reveals that the initial tensile strain rates have negligible impact on the results.The rate-sensitivity coefficient of PBGS is approximately 0.163,which falls within the typical range observed in most geosynthetics.
基金supported by the National Natural Science Foundation of China(No.92160301)the Industrial Technology Development Program,China(No.JCKY2021605 B026)。
文摘The Ti-5Al-2Sn-4Zr-4Mo-2Cr-1Fe(β-CEZ)alloy is considered as a potential structural material in the aviation industry due to its outstanding strength and corrosion resistance.Electrochemical machining(ECM)is an efficient and low-cost technology for manufacturing theβ-CEZ alloy.In ECM,the machining parameter selection and tool design are based on the electrochemical dissolution behavior of the materials.In this study,the electrochemical dissolution behaviors of theβ-CEZ and Ti-6Al-4V(TC4)alloys in NaNO3solution are discussed.The open circuit potential(OCP),Tafel polarization,potentiodynamic polarization,electrochemical impedance spectroscopy(EIS),and current efficiency curves of theβ-CEZ and TC4 alloys are analyzed.The results show that,compared to the TC4 alloy,the passivation film structure is denser and the charge transfer resistance in the dissolution process is greater for theβ-CEZ alloy.Moreover,the dissolved surface morphology of the two titanium-based alloys under different current densities are analyzed.Under low current densities,theβ-CEZ alloy surface comprises dissolution pits and dissolved products,while the TC4 alloy surface comprises a porous honeycomb structure.Under high current densities,the surface waviness of both the alloys improves and the TC4 alloy surface is flatter and smoother than theβ-CEZ alloy surface.Finally,the electrochemical dissolution models ofβ-CEZ and TC4 alloys are proposed.
文摘BACKGROUND The comprehension and utilization of timing theory and behavior change can offer a more extensive and individualized provision of support and treatment alternatives for primipara.This has the potential to enhance the psychological well-being and overall quality of life for primipara,while also furnishing healthcare providers with efficacious interventions to tackle the psychological and physiological obstacles encountered during the stages of pregnancy and postpartum.AIM To explore the effect of timing theory combined with behavior change on selfefficacy,negative emotions and quality of life in patients with primipara.METHODS A total of 80 primipara cases were selected and admitted to our hospital between August 2020 and May 2022.These cases were divided into two groups,namely the observation group and the control group,with 40 cases in each group.The nursing interventions differed between the two groups,with the control group receiving routine nursing and the observation group receiving integrated nursing based on the timing theory and behavior change.The study aimed to compare the pre-and post-nursing scores of Chinese Perceived Stress Scale(CPSS),Edinburgh Postpartum Depression Scale(EPDS),Self-rating Anxiety Scale(SAS),breast milk knowledge,self-efficacy,and SF-36 quality of life in both groups.RESULTS After nursing,the CPSS,EPDS,and SAS scores of the two groups was significantly lower than that before nursing,and the CPSS,EPDS,and SAS scores of the observation group was significantly lower than that of the control group(P=0.002,P=0.011,and P=0.001 respectively).After nursing,the breastfeeding knowledge mastery,selfefficacy,and SF-36 quality of life scores was significantly higher than that before nursing,and the breastfeeding knowledge mastery(P=0.013),self-efficacy(P=0.008),and SF-36 quality of life(P=0.011)scores of the observation group was significantly higher than that of the control group.CONCLUSION The integration of timing theory and behavior change integrated theory has been found to be an effective approach in alleviating negative mood and stress experienced by primipara individuals,while also enhancing their selfefficacy and overall quality of life.This study focuses on the key concepts of timing theory,behavior change,primipara individuals,negative mood,and quality of life.
基金financially supported by National Natural Science Foundation of China(Grant Nos.52088102,51879249)Fundamental Research Funds for the Central Universities(Grant No.202261055)。
文摘The collapse pressure is a key parameter when RTPs are applied in harsh deep-water environments.To investigate the collapse of RTPs,numerical simulations and hydrostatic pressure tests are conducted.For the numerical simulations,the eigenvalue analysis and Riks analysis are combined,in which the Hashin failure criterion and fracture energy stiffness degradation model are used to simulate the progressive failure of composites,and the“infinite”boundary conditions are applied to eliminate the boundary effects.As for the hydrostatic pressure tests,RTP specimens were placed in a hydrostatic chamber after filled with water.It has been observed that the cross-section of the middle part collapses when it reaches the maximum pressure.The collapse pressure obtained from the numerical simulations agrees well with that in the experiment.Meanwhile,the applicability of NASA SP-8007 formula on the collapse pressure prediction was also discussed.It has a relatively greater difference because of the ignorance of the progressive failure of composites.For the parametric study,it is found that RTPs have much higher first-ply-failure pressure when the winding angles are between 50°and 70°.Besides,the effect of debonding and initial ovality,and the contribution of the liner and coating are also discussed.
基金supported by the National Natural Science Foundation of China,No.81772421(to YH).
文摘Distraction spinal cord injury is caused by some degree of distraction or longitudinal tension on the spinal cord and commonly occurs in patients who undergo corrective operation for severe spinal deformity.With the increased degree and duration of distraction,spinal cord injuries become more serious in terms of their neurophysiology,histology,and behavior.Very few studies have been published on the specific characteristics of distraction spinal cord injury.In this study,we systematically review 22 related studies involving animal models of distraction spinal cord injury,focusing particularly on the neurophysiological,histological,and behavioral characteristics of this disease.In addition,we summarize the mechanisms underlying primary and secondary injuries caused by distraction spinal cord injury and clarify the effects of different degrees and durations of distraction on the primary injuries associated with spinal cord injury.We provide new concepts for the establishment of a model of distraction spinal cord injury and related basic research,and provide reference guidelines for the clinical diagnosis and treatment of this disease.
基金supported by the National Key R&D Program of China(No.2021YFB2402001)the Postgraduate Innovation and Entrepreneurship Practice Project of Anhui Province(No.2022cxcysj013)+2 种基金the China Postdoctoral Science Foundation(No.2022T150615)the Fundamental Research Funds for the Central Universities(No.WK5290000002)supported by Youth Innovation Promotion Association CAS(No.Y201768)。
文摘The safety valve is an important component to ensure the safe operation of lithium-ion batteries(LIBs).However,the effect of safety valve type on the thermal runaway(TR)and gas venting behavior of LIBs,as well as the TR hazard severity of LIBs,are not known.In this paper,the TR and gas venting behavior of three 100 A h lithium iron phosphate(LFP)batteries with different safety valves are investigated under overheating.Compared to previous studies,the main contribution of this work is in studying and evaluating the effect of gas venting behavior and TR hazard severity of LFP batteries with three safety valve types.Two significant results are obtained:(Ⅰ)the safety valve type dominates over gas venting pressure of battery during safety venting,the maximum gas venting pressure of LFP batteries with a round safety valve is 3320 Pa,which is one order of magnitude higher than other batteries with oval or cavity safety valve;(Ⅱ)the LFP battery with oval safety valve has the lowest TR hazard as shown by the TR hazard assessment model based on gray-fuzzy analytic hierarchy process.This study reveals the effect of safety valve type on TR and gas venting,providing a clear direction for the safety valve design.