BACKGROUND Oral cancer,which is caused by mucous membrane variation,represents a prevalent malignant tumor in the oral and maxillofacial region,posing a significant threat to patients’lives and safety.While surgical ...BACKGROUND Oral cancer,which is caused by mucous membrane variation,represents a prevalent malignant tumor in the oral and maxillofacial region,posing a significant threat to patients’lives and safety.While surgical intervention stands as a cornerstone treatment for oral cancer patients,it carries the risk of incomplete treatment or high rates of postoperative recurrence.Hence,a multifaceted approach incorporating diverse treatment modalities is essential to enhance patient prognosis.AIM To analyze the application effect of Tongluo Jiedu prescription as adjuvant therapy and its influence on patient prognosis in patients with oral cancer.METHODS Eighty oral cancer patients in our hospital were selected and divided into the observation group and control group by a random number table.The control group was treated with continuous arterial infusion chemotherapy of cisplatin and 5-fluorouracil.The observation group was additionally given Tongluo Jiadu prescription.The inflammatory stress level,peripheral blood T-cell subsets,and immune function of the two groups were subsequently observed.SPSS 21.0 was used for data analysis.RESULTS The observation group demonstrated lower levels of interleukin-6 and C-reactive protein,and a higher level of tumor necrosis factor in comparison to the control group.After treatment,the immune function in the observation group was significantly better than in the control group.CONCLUSION Tongluo Jiedu prescription can improve the immune function and oxidative stress level of patients with oral cancer and accelerate the recovery process.展开更多
Background Global warming leading to heat stress(HS)is becoming a major challenge for broiler production.This study aimed to explore the protective effects of seaweed(Enteromorpha prolifera)polysaccharides(EPS)on the ...Background Global warming leading to heat stress(HS)is becoming a major challenge for broiler production.This study aimed to explore the protective effects of seaweed(Enteromorpha prolifera)polysaccharides(EPS)on the intestinal barrier function,microbial ecology,and performance of broilers under HS.A total of 144 yellow-feathered broilers(male,56 days old)with 682.59±7.38 g were randomly assigned to 3 groups:1)TN(thermal neutral zone,23.6±1.8℃),2)HS(heat stress,33.2±1.5℃ for 10 h/d),and 3)HSE(HS+0.1%EPS).Each group contained 6 replicates with 8 broilers per replicate.The study was conducted for 4 weeks;feed intake and body weights were measured at the end of weeks 2 and 4.At the end of the feeding trial,small intestine samples were collected for histomorphology,antioxidant,secretory immunoglobulin A(s Ig A)content,apoptosis,gene and protein expression analysis;cecal contents were also collected for microbiota analysis based on 16S r DNA sequencing.Results Dietary EPS promoted the average daily gain(ADG)of broilers during 3–4 weeks of HS(P<0.05).At the end of HS on broilers,the activity of total superoxide dismutase(T-SOD),glutathione S-transferase(GST),and the content of s Ig A in jejunum were improved by EPS supplementation(P<0.05).Besides,dietary EPS reduced the epithelial cell apoptosis of jejunum and ileum in heat-stressed broilers(P<0.05).Addition of EPS in HS group broilers'diet upregulated the relative m RNA expression of Occludin,ZO-1,γ-GCLc and IL-10 of the jejunum(P<0.05),whereas downregulated the relative m RNA expression of NF-κB p65,TNF-αand IL-1βof the jejunum(P<0.05).Dietary EPS increased the protein expression of Occludin and ZO-1,whereas it reduced the protein expression of NF-κB p65 and MLCK(P<0.01)and tended to decrease the protein expression of TNF-α(P=0.094)in heat-stressed broilers.Furthermore,the proportions of Bacteroides and Oscillospira among the three groups were positively associated with jejunal apoptosis and pro-inflammatory cytokine expression(P<0.05)and negatively correlated with jejunal Occludin level(P<0.05).However,the proportions of Lactobacillus,Barnesiella,Subdoligranulum,Megasphaera,Collinsella,and Blautia among the three groups were positively related to ADG(P<0.05).Conclusions EPS can be used as a feed additive in yellow-feathered broilers.It effectively improves growth performance and alleviates HS-induced intestinal injury by relieving inflammatory damage and improving the tight junction proteins expression.These beneficial effects may be related to inhibiting NF-κB/MLCK signaling pathway activation and regulation of cecal microbiota.展开更多
BACKGROUND Gastric cancer remains a leading cause of cancer-related mortality globally.Traditional open surgery for gastric cancer is often associated with significant morbidity and prolonged recovery.AIM To evaluate ...BACKGROUND Gastric cancer remains a leading cause of cancer-related mortality globally.Traditional open surgery for gastric cancer is often associated with significant morbidity and prolonged recovery.AIM To evaluate the effectiveness of laparoscopic minimally invasive surgery as an alternative to traditional open surgery for gastric cancer,focusing on its potential to reduce trauma,accelerate recovery,and achieve comparable oncological out-comes.METHODS This study retrospectively analyzed 203 patients with gastric cancer who underwent surgery at the Shanghai Health Medical College Affiliated Chongming Hospital from January 2020 to December 2023.The patients were divided into two groups:Minimally invasive surgery group(n=102),who underwent laparoscopic gastrectomy,and open surgery group(n=101),who underwent traditional open gastrectomy.We compared surgical indicators(surgical incision size,intraop-erative blood loss,surgical duration,and number of lymph nodes dissected),recovery parameters(time to first flatus,time to start eating,time to ambulation,and length of hospital stay),immune function(levels of IgA,IgG,and IgM),intestinal barrier function(levels of D-lactic acid and diamine oxidase),and stress response(levels of C-reactive protein,interleukin-6,and procalcitonin).RESULTS The minimally invasive surgery group demonstrated significantly better outcomes in terms of surgical indicators,including smaller incisions,less blood loss,shorter surgery time,and more lymph nodes dissected(P<0.05 for all).Recovery was also faster in the minimally invasive surgery group,with earlier return of bowel function,earlier initiation of diet,quicker mobilization,and shorter hospital stays(P<0.05 for all).Furthermore,patients in the minimally invasive surgery group had better preserved immune function,superior intestinal barrier function,and a less pronounced stress response postoperatively(P<0.05 for all).CONCLUSION Laparoscopic minimally invasive surgery for gastric cancer not only provides superior surgical indicators and faster recovery but also offers advantages in preserving immune function,protecting intestinal barrier function,and mitigating the stress response compared to traditional open surgery.These findings support the broader adoption of laparoscopic techniques in the management of gastric cancer.展开更多
BASIC PENTACYSTEINE(BPC)transcription factors are essential regulators of plant growth and development.However,BPC functions and the related molecular mechanisms during cucumber(Cucumis sativus L.)responses to abiotic...BASIC PENTACYSTEINE(BPC)transcription factors are essential regulators of plant growth and development.However,BPC functions and the related molecular mechanisms during cucumber(Cucumis sativus L.)responses to abiotic stresses,especially salt stress,remain unknown.We previously determined that salt stress induces CsBPC expression in cucumber.In this study,Csbpc2 transgene-free cucumber plants were created using a CRISPR/Cas9-mediated editing system to explore CsBPC functions associated with the salt stress response.The Csbpc2 mutants had a hypersensitive phenotype,with increased leaf chlorosis,decreased biomass,and increased malondialdehyde and electrolytic leakage levels under salt stress conditions.Additionally,a mutated CsBPC2 resulted in decreased proline and soluble sugar contents and antioxidant enzyme activities,which led to the accumulation of hydrogen peroxide and superoxide radicals.Furthermore,the mutation to CsBPC2 inhibited salinity-induced PM-H+-ATPase and V-H+-ATPase activities,resulting in decreased Na+efflux and increased K+efflux.These findings suggest that CsBPC2 may mediate plant salt stress resistance through its effects on osmoregulation,reactive oxygen species scavenging,and ion homeostasis-related regulatory pathways.However,CsBPC2 also affected ABA signaling.The mutation to CsBPC2 adversely affected salt-induced ABA biosynthesis and the expression of ABA signaling-related genes.Our results indicate that CsBPC2 may enhance the cucumber response to salt stress.It may also function as an important regulator of ABA biosynthesis and signal transduction.These findings will enrich our understanding of the biological functions of BPCs,especially their roles in abiotic stress responses,thereby providing the theoretical basis for improving crop salt tolerance.展开更多
The aim of this work is to develop a three-dimensional model of deep groove ball bearing to investigate the loaded stresses and central displacements of bearing rings. The equivalent stresses and central displacements...The aim of this work is to develop a three-dimensional model of deep groove ball bearing to investigate the loaded stresses and central displacements of bearing rings. The equivalent stresses and central displacements of bearing rings are obtained based on the simulated analysis. Moreover, several parameters, such as load magnitude, raceway groove curvature radius(RGCR), thicknesses of outer and inner rings, are varied to investigate their effects on the equivalent stresses and central displacements of bearing rings. Research results provide useful guidelines for determining the design parameters.展开更多
Abiotic stress reduces plant yield and quality.WRKY transcription factors play key roles in abiotic stress responses in plants,but the molecular mechanisms by which WRKY transcription factors mediate responses to drou...Abiotic stress reduces plant yield and quality.WRKY transcription factors play key roles in abiotic stress responses in plants,but the molecular mechanisms by which WRKY transcription factors mediate responses to drought and osmotic stresses in apple(Malus×domestica Borkh.)remain unclear.Here,we functionally characterized the apple GroupⅢWRKY gene MdWRKY115.qRT-PCR analysis showed that MdWRKY115 expression was up-regulated by drought and osmotic stresses.GUS activity analysis revealed that the promoter activity of MdWRKY115 was enhanced under osmotic stress.Subcellular localization and transactivation assays indicated that MdWRKY115 was localized to the nucleus and had a transcriptional activity domain at the N-terminal region.Transgenic analysis revealed that the overexpression of MdWRKY115 in Arabidopsis plants and in apple callus markedly enhanced their tolerance to drought and osmotic stresses.DNA affinity purification sequencing showed that MdWRKY115 binds to the promoter of the stress-related gene MdRD22.This binding was further verified by an electrophoretic mobility shift assay.Collectively,these findings suggest that MdWRKY115 is an important regulator of osmotic and drought stress tolerance in apple.展开更多
Autophagy is an evolutionarily conserved degradation pathway of lysosomes(in mammals)and vacuoles(in yeasts and plants)from lower yeasts to higher mammals.It wraps unwanted organelles and damaged proteins in a double-...Autophagy is an evolutionarily conserved degradation pathway of lysosomes(in mammals)and vacuoles(in yeasts and plants)from lower yeasts to higher mammals.It wraps unwanted organelles and damaged proteins in a double-membrane structure to transport them to vacuoles for degradation and recycling.In plants,autophagy functions in adaptation to the environment and maintenance of growth and development.This review systematically describes the autophagy process,biological functions,and regulatory mechanisms occurring during plant growth and development and in response to abiotic stresses.It provides a basis for further theoretical research and guidance of agricultural production.展开更多
The extended Kantorovich method is employed to study the local stress concentrations at the vicinity of free edges in symmetrically layered composite laminates subjected to uniaxial tensile load upon polynomial stress...The extended Kantorovich method is employed to study the local stress concentrations at the vicinity of free edges in symmetrically layered composite laminates subjected to uniaxial tensile load upon polynomial stress functions. The stress fields are initially assumed by means of the Lekhnitskii stress functions under the plane strain state. Applying the principle of complementary virtual work,the coupled ordinary differential equations are obtained in which the solutions can be obtained by solving a generalized eigenvalue problem. Then an iterative procedure is established to achieve convergent stress distributions. It should be noted that the stress function based extended Kantorovich method can satisfy both the traction-free and free edge stress boundary conditions during the iterative processes. The stress components near the free edges and in the interior regions are calculated and compared with those obtained results by finite element method(FEM). The convergent stresses have good agreements with those results obtained by three dimensional(3D) FEM. For generality, various layup configurations are considered for the numerical analysis. The results show that the proposed polynomial stress function based extended Kantorovich method is accurate and efficient in predicting the local stresses in composite laminates and computationally much more efficient than the 3D FEM.展开更多
Objective:To explore whether maternal stress exposure during pregnancy impairs cognitive function and white matter ultrastructure in offspring mice.Methods:The parent rats were divided into two groups:pressure exposur...Objective:To explore whether maternal stress exposure during pregnancy impairs cognitive function and white matter ultrastructure in offspring mice.Methods:The parent rats were divided into two groups:pressure exposure group(group PE)and control group(group C),and the positive date of vaginal smear of female SD rats was day 0 of gestation.Female mice in group PE were exposed to binding pressure(3 times/day)on day 14-20 of gestation for 45 min-1 h/time.Behavioral tests(Morris water maze and Y maze)were performed on 1-month-old offspring mice followed by cardiac perfusion of fixed brain specimens and placement in mixed fixative solution.The total volume of white matter,total length and volume of myelinated nerve fibers and total length and volume of myelin sheath were calculated using modern stereoscopic methods,and the inner and outer diameter and inner and outer circumference of the myelin sheath were analyzed.Results:1)Behavioral tests:compared with the group C,the average latency of the 3th and 4th day in the group PE were significantly prolonged,the percentage of the resting time in the quadrant of the platform and the frequency of acrossing the effective area of platform in the fifth day of space exploration experiment were significantly reduced of Morris water maze test,and visiting distance,duration and numbers in novel arm significantly increased of Y-maze test(P<0.05).2)Compared with group C,the total volume of white matter,total length of myelinated nerve fibers,total volume of myelinated nerve fibers and myelin sheath in the group PE were significantly reduced(P<0.05),the inner diameter and outer diameter of myelin sheath decreased significantly(P<0.05),and the inner perimeter,outer perimeter and inner and outer perimeter differences increased significantly(P<0.05).3)There was a correlation between behavioral test results and white matter ultrastructure measurement results.Conclusions:Maternal stress exposure during pregnancy could impair the cognitive function and white matter and its ultrastructure in the offspring,and there was a correlation between decreased cognitive function and white matter damages.展开更多
To review the current research status of positive thought stress reduction therapy(PTSRT),psychosocial functioning of patients with depressive disorders,the shortcomings and outlook of the influence of PTSRT on positi...To review the current research status of positive thought stress reduction therapy(PTSRT),psychosocial functioning of patients with depressive disorders,the shortcomings and outlook of the influence of PTSRT on positive thought awareness,and psychosocial functioning of patients with depressive disorders.This review has the objective to provide clinical healthcare personnel with essential information about the use of PTSRT to improve the level of positive thought and psychosocial functioning of patients with depressive disorders.展开更多
Background:Excessive heat exposure can lead to hyperthermia in humans,which impairs physical performance and disrupts cognitive function.While heat is a known physiological stressor,it is unclear how severe heat stres...Background:Excessive heat exposure can lead to hyperthermia in humans,which impairs physical performance and disrupts cognitive function.While heat is a known physiological stressor,it is unclear how severe heat stress affects brain physiology and function.Methods:Eleven healthy participants were subjected to heat stress from prolonged exercise or warm water immersion until their rectal temperatures(T_(re))attained 39.5℃,inducing exertional or passive hyperthermia,respectively.In a separate trial,blended ice was ingested before and during exercise as a cooling strategy.Data were compared to a control condition with seated rest(normothermic).Brain temperature(T_(br)),cerebral perfusion,and task-based brain activity were assessed using magnetic resonance imaging techniques.Results:T_(br)in motor cortex was found to be tightly regulated at rest(37.3℃±0.4℃(mean±SD))despite fluctuations in T_(re).With the development of hyperthermia,T_(br)increases and dovetails with the rising T_(re).Bilateral motor cortical activity was suppressed during high-intensity plantarflexion tasks,implying a reduced central motor drive in hyperthermic participants(T_(re)=38.5℃±0.1℃).Global gray matter perfusion and regional perfusion in sensorimotor cortex were reduced with passive hyperthermia.Executive function was poorer under a passive hyperthermic state,and this could relate to compromised visual processing as indicated by the reduced activation of left lateral-occipital cortex.Conversely,ingestion of blended ice before and during exercise alleviated the rise in both T_(re)and T_(bc)and mitigated heat-related neural perturbations.Conclusion:Severe heat exposure elevates T_(br),disrupts motor cortical activity and executive function,and this can lead to impairment of physical and cognitive performance.展开更多
Traumatic brain injury involves complex pathophysiological mechanisms,among which oxidative stress significantly contributes to the occurrence of secondary injury.In this study,we evaluated hypidone hydrochloride(YL-0...Traumatic brain injury involves complex pathophysiological mechanisms,among which oxidative stress significantly contributes to the occurrence of secondary injury.In this study,we evaluated hypidone hydrochloride(YL-0919),a self-developed antidepressant with selective sigma-1 receptor agonist properties,and its associated mechanisms and targets in traumatic brain injury.Behavioral experiments to assess functional deficits were followed by assessment of neuronal damage through histological analyses and examination of blood-brain barrier permeability and brain edema.Next,we investigated the antioxidative effects of YL-0919 by assessing the levels of traditional markers of oxidative stress in vivo in mice and in vitro in HT22 cells.Finally,the targeted action of YL-0919 was verified by employing a sigma-1 receptor antagonist(BD-1047).Our findings demonstrated that YL-0919 markedly improved deficits in motor function and spatial cognition on day 3 post traumatic brain injury,while also decreasing neuronal mortality and reversing blood-brain barrier disruption and brain edema.Furthermore,YL-0919 effectively combated oxidative stress both in vivo and in vitro.The protective effects of YL-0919 were partially inhibited by BD-1047.These results indicated that YL-0919 relieved impairments in motor and spatial cognition by restraining oxidative stress,a neuroprotective effect that was partially reversed by the sigma-1 receptor antagonist BD-1047.YL-0919 may have potential as a new treatment for traumatic brain injury.展开更多
In order to improve the bending load-carrying capacity (BLCC) of undermatched butt joint under three-point bending load, the influence of joint geometric parameters on stress concentration factors (SCF) at the wel...In order to improve the bending load-carrying capacity (BLCC) of undermatched butt joint under three-point bending load, the influence of joint geometric parameters on stress concentration factors (SCF) at the weld bottom center and the weld toe of uudermatched butt joint with single V-groove are studied respectively based on the finite element method in this paper. Results show that the reinforcement height and the cover pass width play decisive role in the BLCC for undermatched butt joint. BLCC of undermatched butt joint can be improved by choosing the appropriate joint geometric parameters.展开更多
[Objective] To study effects of Chinese herbal additive on immunologic functions and productive performance of dairy cows, [Method] A total of 20 healthy dairy cows were randomly divided into control group and experim...[Objective] To study effects of Chinese herbal additive on immunologic functions and productive performance of dairy cows, [Method] A total of 20 healthy dairy cows were randomly divided into control group and experimental group. They were respectively fed a common basal diet and the basal diet containing 100 g Chinese herbal additives. The trial lasted for 49 d. [ Result] The 4% fat corrected milk yield (FCM) production, milk yield after weight correction, quantity of solid-not-fat and ash content in the experimental group were significantly higher than those in the control group ( P 〈 0.01 ). The total lymphocytes (LYM) number of peripheral blood, the percentage of lymphocytes, and IgG concentration in the experimental group were significantly higher than those in the control group on Day 14, 28 and 42 ( P 〈 0.01 ). [ Conclusion] The Chinese herbal additive can enhance the lactation performance and immunologic function of dairy cows.展开更多
In this paper, inverse solutions are obtained for the class of 2D steady incompressible couple stress fluid flows. This class consists of flows for which the vorticity distribution is given by ▽2ψ=ψ+f(x,y). The so...In this paper, inverse solutions are obtained for the class of 2D steady incompressible couple stress fluid flows. This class consists of flows for which the vorticity distribution is given by ▽2ψ=ψ+f(x,y). The solutions are obtained by applying the inverse method, which makes certain hypotheses regarding the form of the velocity field and pressure but without making any regarding the boundaries of the domain occupied by the fluid. Inverse solutions are derived for three different forms of f(x,y).展开更多
A three-dimensional(3D)thermomechanical vibration model is developed for rotating pre-twisted functionally graded(FG)microbeams according to the refined shear deformation theory(RSDT)and the modified couple stress the...A three-dimensional(3D)thermomechanical vibration model is developed for rotating pre-twisted functionally graded(FG)microbeams according to the refined shear deformation theory(RSDT)and the modified couple stress theory(MCST).The material properties are assumed to follow a power-law distribution along the chordwise direction.The model introduces one axial stretching variable and four transverse deflection variables including two pure bending components and two pure shear ones.The complex modal analysis and assumed mode methods are used to solve the governing equations of motion under different boundary conditions(BCs).Several examples are presented to verify the effectiveness of the developed model.By coupling the slenderness ratio,gradient index,rotation speed,and size effect with the pre-twisted angle,the effects of these factors on the thermomechanical vibration of the microbeam with different BCs are investigated.It is found that with the increase in the pre-twisted angle,the critical slenderness ratio and gradient index corresponding to the thermal instability of the microbeam increase,while the critical material length scale parameter(MLSP)and rotation speed decrease.The sensitivity of the fundamental frequency to temperature increases with the increasing slenderness ratio and gradient index,and decreases with the other increasing parameters.Moreover,the size effect can suppress the dynamic stiffening effect and enhance the Coriolis effect.Finally,the mode transition is quantitatively demonstrated by a modal assurance criterion(MAC).展开更多
Due to its toxicity, dichlorvos—a common organophosphate pesticide—poses significant risks to human health. This study utilized male Wistar rats to explore the potential protective effects of L-arginine supplementat...Due to its toxicity, dichlorvos—a common organophosphate pesticide—poses significant risks to human health. This study utilized male Wistar rats to explore the potential protective effects of L-arginine supplementation against dichlorvos-induced toxicity, focusing on cardiotoxicity, haematotoxicity and oxidative stress. The rats were divided into four groups: Control, L-arginine (L), Dichlorvos (D), and L-arginine + Dichlorvos (L + D). Dichlorvos was administered to the D group, L-arginine (100 mg/kg) to the L group, and both L-arginine and dichlorvos to the L + D group. The study evaluated various parameters, including cardiovascular, oxidative stress markers, and haematological indices. Significant changes in haematological parameters such as haemoglobin (Hb), haematocrit (HCT), and red blood cell count (RBC) indicated haematotoxicity after dichlorvos administration. Additionally, elevated cardiac markers, including lactate dehydrogenase (LDH) and creatine kinase-MB (CK-MB), suggested cardiotoxic effects. Exposure to dichlorvos also resulted in decreased antioxidant enzyme levels and increased oxidative stress indicators like malondialdehyde (MDA). Remarkably, L-arginine supplementation mitigated the damage caused by dichlorvos. It normalized the altered haematological parameters, demonstrating its protective effect against haematotoxicity. The rise in cardiac markers was reduced with L-arginine supplementation, indicating protection against cardiotoxicity. Moreover, L-arginine significantly decreased oxidative stress, as evidenced by lower MDA levels and restored antioxidant enzyme activity. In conclusion, L-arginine supplementation in male Wistar rats showed promising protective effects against dichlorvos-induced cardiotoxicity, haematotoxicity and oxidative stress. This suggests that L-arginine may offer a beneficial intervention to mitigate the adverse effects of dichlorvos on blood and heart health, paving the way for potential treatments for pesticide poisoning.展开更多
In the field of phonology,the suprasegmental features has now won wide attention.Suprasegmental features or prosodic features are those aspects of speech that involve more than one sound segment.The principal supraseg...In the field of phonology,the suprasegmental features has now won wide attention.Suprasegmental features or prosodic features are those aspects of speech that involve more than one sound segment.The principal suprasegmental feachures are syllable,stress,tone and intonation.This paper is going to focus on the feature of stress.It will cover the definition,categories,realization and functions of stress in detail.展开更多
Root border cells, previously referred to as sloughed root cap cells, is a special cell population which separates in large numbers from the periphery of the root cap and accumulates in the root tip. Recent evidence r...Root border cells, previously referred to as sloughed root cap cells, is a special cell population which separates in large numbers from the periphery of the root cap and accumulates in the root tip. Recent evidence reveals that border cells, whose development is regulated by endogenous and exogenous signals, are biologically viable in the majority of higher plant species. As soon as border cells detach from root cap periphery, their metabolic activity dramatically increases in accordance with a differential gene expression from that in root cap cells. Recently, PsUGT1 and RCPME1, relevant to the early and late stage of border cell development, respectively, have been cloned and functionally identified. Border cells can synthesize specially and export a diverse array of chemicals including anthocyanins, antibiotics, special enzymes and other substances, that either inhibit or promote the growth of other entities in rhizosphere such as bacteria, fungi, viruses, and nematodes, and also antagonize some toxic chemicals around the root tip in soil such as aluminum toxicity. Therefore, there are multiple biological roles played by border cells during plant growth and development.展开更多
In this paper, the dynamic behavior of a permeable crack in functionally graded piezoelectric/piezomagnetic materials is investigated. To make the analysis tractable, it is assumed that the material properties vary ex...In this paper, the dynamic behavior of a permeable crack in functionally graded piezoelectric/piezomagnetic materials is investigated. To make the analysis tractable, it is assumed that the material properties vary exponentially with the coordinate parallel to the crack. By using the Fourier transform, the problem can be solved with the help of a pair of dual integral equations in which the unknown is the jump of displacements across the crack surfaces. These equations are solved to obtain the relations between the electric filed, the magnetic flux field and the dynamic stress field near the crack tips using the Schmidt method. Numerical examples are provided to show the effect of the functionally graded parameter and the circular frequency of the incident waves upon the stress, the electric displacement and the magnetic flux intensity factors of the crack.展开更多
基金Supported by the Hebei Province Traditional Chinese Medicine Research Programme Project,No.2022428.
文摘BACKGROUND Oral cancer,which is caused by mucous membrane variation,represents a prevalent malignant tumor in the oral and maxillofacial region,posing a significant threat to patients’lives and safety.While surgical intervention stands as a cornerstone treatment for oral cancer patients,it carries the risk of incomplete treatment or high rates of postoperative recurrence.Hence,a multifaceted approach incorporating diverse treatment modalities is essential to enhance patient prognosis.AIM To analyze the application effect of Tongluo Jiedu prescription as adjuvant therapy and its influence on patient prognosis in patients with oral cancer.METHODS Eighty oral cancer patients in our hospital were selected and divided into the observation group and control group by a random number table.The control group was treated with continuous arterial infusion chemotherapy of cisplatin and 5-fluorouracil.The observation group was additionally given Tongluo Jiadu prescription.The inflammatory stress level,peripheral blood T-cell subsets,and immune function of the two groups were subsequently observed.SPSS 21.0 was used for data analysis.RESULTS The observation group demonstrated lower levels of interleukin-6 and C-reactive protein,and a higher level of tumor necrosis factor in comparison to the control group.After treatment,the immune function in the observation group was significantly better than in the control group.CONCLUSION Tongluo Jiedu prescription can improve the immune function and oxidative stress level of patients with oral cancer and accelerate the recovery process.
基金funded by the National Nature Science Foundation of China(32002196)。
文摘Background Global warming leading to heat stress(HS)is becoming a major challenge for broiler production.This study aimed to explore the protective effects of seaweed(Enteromorpha prolifera)polysaccharides(EPS)on the intestinal barrier function,microbial ecology,and performance of broilers under HS.A total of 144 yellow-feathered broilers(male,56 days old)with 682.59±7.38 g were randomly assigned to 3 groups:1)TN(thermal neutral zone,23.6±1.8℃),2)HS(heat stress,33.2±1.5℃ for 10 h/d),and 3)HSE(HS+0.1%EPS).Each group contained 6 replicates with 8 broilers per replicate.The study was conducted for 4 weeks;feed intake and body weights were measured at the end of weeks 2 and 4.At the end of the feeding trial,small intestine samples were collected for histomorphology,antioxidant,secretory immunoglobulin A(s Ig A)content,apoptosis,gene and protein expression analysis;cecal contents were also collected for microbiota analysis based on 16S r DNA sequencing.Results Dietary EPS promoted the average daily gain(ADG)of broilers during 3–4 weeks of HS(P<0.05).At the end of HS on broilers,the activity of total superoxide dismutase(T-SOD),glutathione S-transferase(GST),and the content of s Ig A in jejunum were improved by EPS supplementation(P<0.05).Besides,dietary EPS reduced the epithelial cell apoptosis of jejunum and ileum in heat-stressed broilers(P<0.05).Addition of EPS in HS group broilers'diet upregulated the relative m RNA expression of Occludin,ZO-1,γ-GCLc and IL-10 of the jejunum(P<0.05),whereas downregulated the relative m RNA expression of NF-κB p65,TNF-αand IL-1βof the jejunum(P<0.05).Dietary EPS increased the protein expression of Occludin and ZO-1,whereas it reduced the protein expression of NF-κB p65 and MLCK(P<0.01)and tended to decrease the protein expression of TNF-α(P=0.094)in heat-stressed broilers.Furthermore,the proportions of Bacteroides and Oscillospira among the three groups were positively associated with jejunal apoptosis and pro-inflammatory cytokine expression(P<0.05)and negatively correlated with jejunal Occludin level(P<0.05).However,the proportions of Lactobacillus,Barnesiella,Subdoligranulum,Megasphaera,Collinsella,and Blautia among the three groups were positively related to ADG(P<0.05).Conclusions EPS can be used as a feed additive in yellow-feathered broilers.It effectively improves growth performance and alleviates HS-induced intestinal injury by relieving inflammatory damage and improving the tight junction proteins expression.These beneficial effects may be related to inhibiting NF-κB/MLCK signaling pathway activation and regulation of cecal microbiota.
基金Shanghai Chongming District Sustainable Development Science and Technology Innovation Action Plan,No.CKY2020-11.
文摘BACKGROUND Gastric cancer remains a leading cause of cancer-related mortality globally.Traditional open surgery for gastric cancer is often associated with significant morbidity and prolonged recovery.AIM To evaluate the effectiveness of laparoscopic minimally invasive surgery as an alternative to traditional open surgery for gastric cancer,focusing on its potential to reduce trauma,accelerate recovery,and achieve comparable oncological out-comes.METHODS This study retrospectively analyzed 203 patients with gastric cancer who underwent surgery at the Shanghai Health Medical College Affiliated Chongming Hospital from January 2020 to December 2023.The patients were divided into two groups:Minimally invasive surgery group(n=102),who underwent laparoscopic gastrectomy,and open surgery group(n=101),who underwent traditional open gastrectomy.We compared surgical indicators(surgical incision size,intraop-erative blood loss,surgical duration,and number of lymph nodes dissected),recovery parameters(time to first flatus,time to start eating,time to ambulation,and length of hospital stay),immune function(levels of IgA,IgG,and IgM),intestinal barrier function(levels of D-lactic acid and diamine oxidase),and stress response(levels of C-reactive protein,interleukin-6,and procalcitonin).RESULTS The minimally invasive surgery group demonstrated significantly better outcomes in terms of surgical indicators,including smaller incisions,less blood loss,shorter surgery time,and more lymph nodes dissected(P<0.05 for all).Recovery was also faster in the minimally invasive surgery group,with earlier return of bowel function,earlier initiation of diet,quicker mobilization,and shorter hospital stays(P<0.05 for all).Furthermore,patients in the minimally invasive surgery group had better preserved immune function,superior intestinal barrier function,and a less pronounced stress response postoperatively(P<0.05 for all).CONCLUSION Laparoscopic minimally invasive surgery for gastric cancer not only provides superior surgical indicators and faster recovery but also offers advantages in preserving immune function,protecting intestinal barrier function,and mitigating the stress response compared to traditional open surgery.These findings support the broader adoption of laparoscopic techniques in the management of gastric cancer.
基金This work was supported by the National Natural Science Foundation of China(No.31972480 and 32260800)the Earmarked fund for Modern Agro-industry Technology Research System in China(CARS-25-C-01)+2 种基金the Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences(CAASASTIPIVFCAAS)the Key Laboratory of Horticultural Crop Biology and Germplasm Innovation,Ministry of Agriculture,Chinathe Natural Science Foundation of Jiangxi Province(20212BAB215004).
文摘BASIC PENTACYSTEINE(BPC)transcription factors are essential regulators of plant growth and development.However,BPC functions and the related molecular mechanisms during cucumber(Cucumis sativus L.)responses to abiotic stresses,especially salt stress,remain unknown.We previously determined that salt stress induces CsBPC expression in cucumber.In this study,Csbpc2 transgene-free cucumber plants were created using a CRISPR/Cas9-mediated editing system to explore CsBPC functions associated with the salt stress response.The Csbpc2 mutants had a hypersensitive phenotype,with increased leaf chlorosis,decreased biomass,and increased malondialdehyde and electrolytic leakage levels under salt stress conditions.Additionally,a mutated CsBPC2 resulted in decreased proline and soluble sugar contents and antioxidant enzyme activities,which led to the accumulation of hydrogen peroxide and superoxide radicals.Furthermore,the mutation to CsBPC2 inhibited salinity-induced PM-H+-ATPase and V-H+-ATPase activities,resulting in decreased Na+efflux and increased K+efflux.These findings suggest that CsBPC2 may mediate plant salt stress resistance through its effects on osmoregulation,reactive oxygen species scavenging,and ion homeostasis-related regulatory pathways.However,CsBPC2 also affected ABA signaling.The mutation to CsBPC2 adversely affected salt-induced ABA biosynthesis and the expression of ABA signaling-related genes.Our results indicate that CsBPC2 may enhance the cucumber response to salt stress.It may also function as an important regulator of ABA biosynthesis and signal transduction.These findings will enrich our understanding of the biological functions of BPCs,especially their roles in abiotic stress responses,thereby providing the theoretical basis for improving crop salt tolerance.
基金the National Natural Science Foundation of China (No. 51605354)the Fundamental Research Funds for the Central Universities (WUT: 2015IVA021)+1 种基金the Innovative Research Team Development Program of Ministry of Education of China (No. IRT13087)the High-end Talent Leading Program of Hubei Province (No. 201286)
文摘The aim of this work is to develop a three-dimensional model of deep groove ball bearing to investigate the loaded stresses and central displacements of bearing rings. The equivalent stresses and central displacements of bearing rings are obtained based on the simulated analysis. Moreover, several parameters, such as load magnitude, raceway groove curvature radius(RGCR), thicknesses of outer and inner rings, are varied to investigate their effects on the equivalent stresses and central displacements of bearing rings. Research results provide useful guidelines for determining the design parameters.
基金supported by grants from the Natural Science Foundation of Hebei Province(Grant No.C2022204086)the Hebei Apple Innovation Team of Modern Agricultural Industry Technology System(Grant No.HBCT2021100211)the National Natural Science Foundation of China(Grant No.32072524).
文摘Abiotic stress reduces plant yield and quality.WRKY transcription factors play key roles in abiotic stress responses in plants,but the molecular mechanisms by which WRKY transcription factors mediate responses to drought and osmotic stresses in apple(Malus×domestica Borkh.)remain unclear.Here,we functionally characterized the apple GroupⅢWRKY gene MdWRKY115.qRT-PCR analysis showed that MdWRKY115 expression was up-regulated by drought and osmotic stresses.GUS activity analysis revealed that the promoter activity of MdWRKY115 was enhanced under osmotic stress.Subcellular localization and transactivation assays indicated that MdWRKY115 was localized to the nucleus and had a transcriptional activity domain at the N-terminal region.Transgenic analysis revealed that the overexpression of MdWRKY115 in Arabidopsis plants and in apple callus markedly enhanced their tolerance to drought and osmotic stresses.DNA affinity purification sequencing showed that MdWRKY115 binds to the promoter of the stress-related gene MdRD22.This binding was further verified by an electrophoretic mobility shift assay.Collectively,these findings suggest that MdWRKY115 is an important regulator of osmotic and drought stress tolerance in apple.
基金the Shandong Natural Science Foundation(ZR2020QC114)the National Natural Science Foundation of China(32001542,32001545)+1 种基金the Agricultural Variety Improvement Project of Shandong Province(2021LZGC013)the Shandong Academy of Agricultural Sciences Innovation Project(CXGC2023A01,CXGC2023C02).
文摘Autophagy is an evolutionarily conserved degradation pathway of lysosomes(in mammals)and vacuoles(in yeasts and plants)from lower yeasts to higher mammals.It wraps unwanted organelles and damaged proteins in a double-membrane structure to transport them to vacuoles for degradation and recycling.In plants,autophagy functions in adaptation to the environment and maintenance of growth and development.This review systematically describes the autophagy process,biological functions,and regulatory mechanisms occurring during plant growth and development and in response to abiotic stresses.It provides a basis for further theoretical research and guidance of agricultural production.
基金supported by the National Natural Science Foundation of China (Grants 11372145, 11372146, and 11272161)the State Key Laboratory of Mechanics and Control of Mechanical Structures (Nanjing University of Aeronautics and astronautics) (Grant MCMS-0516Y01)+1 种基金Zhejiang Provincial Top Key Discipline of Mechanics Open Foundation (Grant xklx1601)the K. C. Wong Magna Fund through Ningbo University
文摘The extended Kantorovich method is employed to study the local stress concentrations at the vicinity of free edges in symmetrically layered composite laminates subjected to uniaxial tensile load upon polynomial stress functions. The stress fields are initially assumed by means of the Lekhnitskii stress functions under the plane strain state. Applying the principle of complementary virtual work,the coupled ordinary differential equations are obtained in which the solutions can be obtained by solving a generalized eigenvalue problem. Then an iterative procedure is established to achieve convergent stress distributions. It should be noted that the stress function based extended Kantorovich method can satisfy both the traction-free and free edge stress boundary conditions during the iterative processes. The stress components near the free edges and in the interior regions are calculated and compared with those obtained results by finite element method(FEM). The convergent stresses have good agreements with those results obtained by three dimensional(3D) FEM. For generality, various layup configurations are considered for the numerical analysis. The results show that the proposed polynomial stress function based extended Kantorovich method is accurate and efficient in predicting the local stresses in composite laminates and computationally much more efficient than the 3D FEM.
基金Shaanxi Province natural science basic research program (No.2023-JC-QN-0961)。
文摘Objective:To explore whether maternal stress exposure during pregnancy impairs cognitive function and white matter ultrastructure in offspring mice.Methods:The parent rats were divided into two groups:pressure exposure group(group PE)and control group(group C),and the positive date of vaginal smear of female SD rats was day 0 of gestation.Female mice in group PE were exposed to binding pressure(3 times/day)on day 14-20 of gestation for 45 min-1 h/time.Behavioral tests(Morris water maze and Y maze)were performed on 1-month-old offspring mice followed by cardiac perfusion of fixed brain specimens and placement in mixed fixative solution.The total volume of white matter,total length and volume of myelinated nerve fibers and total length and volume of myelin sheath were calculated using modern stereoscopic methods,and the inner and outer diameter and inner and outer circumference of the myelin sheath were analyzed.Results:1)Behavioral tests:compared with the group C,the average latency of the 3th and 4th day in the group PE were significantly prolonged,the percentage of the resting time in the quadrant of the platform and the frequency of acrossing the effective area of platform in the fifth day of space exploration experiment were significantly reduced of Morris water maze test,and visiting distance,duration and numbers in novel arm significantly increased of Y-maze test(P<0.05).2)Compared with group C,the total volume of white matter,total length of myelinated nerve fibers,total volume of myelinated nerve fibers and myelin sheath in the group PE were significantly reduced(P<0.05),the inner diameter and outer diameter of myelin sheath decreased significantly(P<0.05),and the inner perimeter,outer perimeter and inner and outer perimeter differences increased significantly(P<0.05).3)There was a correlation between behavioral test results and white matter ultrastructure measurement results.Conclusions:Maternal stress exposure during pregnancy could impair the cognitive function and white matter and its ultrastructure in the offspring,and there was a correlation between decreased cognitive function and white matter damages.
基金Research Project of Yunnan Provincial Psychiatric Hospital(No:Provincial Jing Research 2022-13)。
文摘To review the current research status of positive thought stress reduction therapy(PTSRT),psychosocial functioning of patients with depressive disorders,the shortcomings and outlook of the influence of PTSRT on positive thought awareness,and psychosocial functioning of patients with depressive disorders.This review has the objective to provide clinical healthcare personnel with essential information about the use of PTSRT to improve the level of positive thought and psychosocial functioning of patients with depressive disorders.
基金supported by Defence Innovative Research Program(DIRP)Grant(PA No.9015102335)from Defence Research&Technology Office,Ministry of Defence,Singapore。
文摘Background:Excessive heat exposure can lead to hyperthermia in humans,which impairs physical performance and disrupts cognitive function.While heat is a known physiological stressor,it is unclear how severe heat stress affects brain physiology and function.Methods:Eleven healthy participants were subjected to heat stress from prolonged exercise or warm water immersion until their rectal temperatures(T_(re))attained 39.5℃,inducing exertional or passive hyperthermia,respectively.In a separate trial,blended ice was ingested before and during exercise as a cooling strategy.Data were compared to a control condition with seated rest(normothermic).Brain temperature(T_(br)),cerebral perfusion,and task-based brain activity were assessed using magnetic resonance imaging techniques.Results:T_(br)in motor cortex was found to be tightly regulated at rest(37.3℃±0.4℃(mean±SD))despite fluctuations in T_(re).With the development of hyperthermia,T_(br)increases and dovetails with the rising T_(re).Bilateral motor cortical activity was suppressed during high-intensity plantarflexion tasks,implying a reduced central motor drive in hyperthermic participants(T_(re)=38.5℃±0.1℃).Global gray matter perfusion and regional perfusion in sensorimotor cortex were reduced with passive hyperthermia.Executive function was poorer under a passive hyperthermic state,and this could relate to compromised visual processing as indicated by the reduced activation of left lateral-occipital cortex.Conversely,ingestion of blended ice before and during exercise alleviated the rise in both T_(re)and T_(bc)and mitigated heat-related neural perturbations.Conclusion:Severe heat exposure elevates T_(br),disrupts motor cortical activity and executive function,and this can lead to impairment of physical and cognitive performance.
基金supported by the National Natural Science Foundation of China,Nos.82204360(to HM)and 82270411(to GW)National Science and Technology Innovation 2030 Major Program,No.2021ZD0200900(to YL)。
文摘Traumatic brain injury involves complex pathophysiological mechanisms,among which oxidative stress significantly contributes to the occurrence of secondary injury.In this study,we evaluated hypidone hydrochloride(YL-0919),a self-developed antidepressant with selective sigma-1 receptor agonist properties,and its associated mechanisms and targets in traumatic brain injury.Behavioral experiments to assess functional deficits were followed by assessment of neuronal damage through histological analyses and examination of blood-brain barrier permeability and brain edema.Next,we investigated the antioxidative effects of YL-0919 by assessing the levels of traditional markers of oxidative stress in vivo in mice and in vitro in HT22 cells.Finally,the targeted action of YL-0919 was verified by employing a sigma-1 receptor antagonist(BD-1047).Our findings demonstrated that YL-0919 markedly improved deficits in motor function and spatial cognition on day 3 post traumatic brain injury,while also decreasing neuronal mortality and reversing blood-brain barrier disruption and brain edema.Furthermore,YL-0919 effectively combated oxidative stress both in vivo and in vitro.The protective effects of YL-0919 were partially inhibited by BD-1047.These results indicated that YL-0919 relieved impairments in motor and spatial cognition by restraining oxidative stress,a neuroprotective effect that was partially reversed by the sigma-1 receptor antagonist BD-1047.YL-0919 may have potential as a new treatment for traumatic brain injury.
基金The authors are grateful to be financially supported by Projects of Natural Science Foundation of Heilongjiang Province (No. E201458) , State Key Lab of Advanced Welding and Joining, Har- bin Institute of Technology (AWJ-M13-14) and Hei longjiang Prov- ince Department of Education (12541679).
文摘In order to improve the bending load-carrying capacity (BLCC) of undermatched butt joint under three-point bending load, the influence of joint geometric parameters on stress concentration factors (SCF) at the weld bottom center and the weld toe of uudermatched butt joint with single V-groove are studied respectively based on the finite element method in this paper. Results show that the reinforcement height and the cover pass width play decisive role in the BLCC for undermatched butt joint. BLCC of undermatched butt joint can be improved by choosing the appropriate joint geometric parameters.
基金supported by Key Project " Improvement and Mechanism of Anti-heat Stress Chinese Herbal Additive of DairyCows" of Wuhan Bureau of Education (2006207)
文摘[Objective] To study effects of Chinese herbal additive on immunologic functions and productive performance of dairy cows, [Method] A total of 20 healthy dairy cows were randomly divided into control group and experimental group. They were respectively fed a common basal diet and the basal diet containing 100 g Chinese herbal additives. The trial lasted for 49 d. [ Result] The 4% fat corrected milk yield (FCM) production, milk yield after weight correction, quantity of solid-not-fat and ash content in the experimental group were significantly higher than those in the control group ( P 〈 0.01 ). The total lymphocytes (LYM) number of peripheral blood, the percentage of lymphocytes, and IgG concentration in the experimental group were significantly higher than those in the control group on Day 14, 28 and 42 ( P 〈 0.01 ). [ Conclusion] The Chinese herbal additive can enhance the lactation performance and immunologic function of dairy cows.
文摘In this paper, inverse solutions are obtained for the class of 2D steady incompressible couple stress fluid flows. This class consists of flows for which the vorticity distribution is given by ▽2ψ=ψ+f(x,y). The solutions are obtained by applying the inverse method, which makes certain hypotheses regarding the form of the velocity field and pressure but without making any regarding the boundaries of the domain occupied by the fluid. Inverse solutions are derived for three different forms of f(x,y).
基金the National Natural Science Foundation of China(Nos.11602204 and 12102373)the Fundamental Research Funds for the Central Universities of China(Nos.2682022ZTPY081 and 2682022CX056)the Natural Science Foundation of Sichuan Province of China(Nos.2023NSFSC0849,2023NSFSC1300,2022NSFSC1938,and 2022NSFSC2003)。
文摘A three-dimensional(3D)thermomechanical vibration model is developed for rotating pre-twisted functionally graded(FG)microbeams according to the refined shear deformation theory(RSDT)and the modified couple stress theory(MCST).The material properties are assumed to follow a power-law distribution along the chordwise direction.The model introduces one axial stretching variable and four transverse deflection variables including two pure bending components and two pure shear ones.The complex modal analysis and assumed mode methods are used to solve the governing equations of motion under different boundary conditions(BCs).Several examples are presented to verify the effectiveness of the developed model.By coupling the slenderness ratio,gradient index,rotation speed,and size effect with the pre-twisted angle,the effects of these factors on the thermomechanical vibration of the microbeam with different BCs are investigated.It is found that with the increase in the pre-twisted angle,the critical slenderness ratio and gradient index corresponding to the thermal instability of the microbeam increase,while the critical material length scale parameter(MLSP)and rotation speed decrease.The sensitivity of the fundamental frequency to temperature increases with the increasing slenderness ratio and gradient index,and decreases with the other increasing parameters.Moreover,the size effect can suppress the dynamic stiffening effect and enhance the Coriolis effect.Finally,the mode transition is quantitatively demonstrated by a modal assurance criterion(MAC).
文摘Due to its toxicity, dichlorvos—a common organophosphate pesticide—poses significant risks to human health. This study utilized male Wistar rats to explore the potential protective effects of L-arginine supplementation against dichlorvos-induced toxicity, focusing on cardiotoxicity, haematotoxicity and oxidative stress. The rats were divided into four groups: Control, L-arginine (L), Dichlorvos (D), and L-arginine + Dichlorvos (L + D). Dichlorvos was administered to the D group, L-arginine (100 mg/kg) to the L group, and both L-arginine and dichlorvos to the L + D group. The study evaluated various parameters, including cardiovascular, oxidative stress markers, and haematological indices. Significant changes in haematological parameters such as haemoglobin (Hb), haematocrit (HCT), and red blood cell count (RBC) indicated haematotoxicity after dichlorvos administration. Additionally, elevated cardiac markers, including lactate dehydrogenase (LDH) and creatine kinase-MB (CK-MB), suggested cardiotoxic effects. Exposure to dichlorvos also resulted in decreased antioxidant enzyme levels and increased oxidative stress indicators like malondialdehyde (MDA). Remarkably, L-arginine supplementation mitigated the damage caused by dichlorvos. It normalized the altered haematological parameters, demonstrating its protective effect against haematotoxicity. The rise in cardiac markers was reduced with L-arginine supplementation, indicating protection against cardiotoxicity. Moreover, L-arginine significantly decreased oxidative stress, as evidenced by lower MDA levels and restored antioxidant enzyme activity. In conclusion, L-arginine supplementation in male Wistar rats showed promising protective effects against dichlorvos-induced cardiotoxicity, haematotoxicity and oxidative stress. This suggests that L-arginine may offer a beneficial intervention to mitigate the adverse effects of dichlorvos on blood and heart health, paving the way for potential treatments for pesticide poisoning.
文摘In the field of phonology,the suprasegmental features has now won wide attention.Suprasegmental features or prosodic features are those aspects of speech that involve more than one sound segment.The principal suprasegmental feachures are syllable,stress,tone and intonation.This paper is going to focus on the feature of stress.It will cover the definition,categories,realization and functions of stress in detail.
文摘Root border cells, previously referred to as sloughed root cap cells, is a special cell population which separates in large numbers from the periphery of the root cap and accumulates in the root tip. Recent evidence reveals that border cells, whose development is regulated by endogenous and exogenous signals, are biologically viable in the majority of higher plant species. As soon as border cells detach from root cap periphery, their metabolic activity dramatically increases in accordance with a differential gene expression from that in root cap cells. Recently, PsUGT1 and RCPME1, relevant to the early and late stage of border cell development, respectively, have been cloned and functionally identified. Border cells can synthesize specially and export a diverse array of chemicals including anthocyanins, antibiotics, special enzymes and other substances, that either inhibit or promote the growth of other entities in rhizosphere such as bacteria, fungi, viruses, and nematodes, and also antagonize some toxic chemicals around the root tip in soil such as aluminum toxicity. Therefore, there are multiple biological roles played by border cells during plant growth and development.
基金Project supported by the National Natural Science Foundation of China (Nos.90405016 and 10572044)the Special Research Fund for the Doctoral Program of Higher Education (No.2004021334)
文摘In this paper, the dynamic behavior of a permeable crack in functionally graded piezoelectric/piezomagnetic materials is investigated. To make the analysis tractable, it is assumed that the material properties vary exponentially with the coordinate parallel to the crack. By using the Fourier transform, the problem can be solved with the help of a pair of dual integral equations in which the unknown is the jump of displacements across the crack surfaces. These equations are solved to obtain the relations between the electric filed, the magnetic flux field and the dynamic stress field near the crack tips using the Schmidt method. Numerical examples are provided to show the effect of the functionally graded parameter and the circular frequency of the incident waves upon the stress, the electric displacement and the magnetic flux intensity factors of the crack.