Microglia,originating from primitive macrophages in the yolk sac,serves as both immune system defenders and regulators of homeostasis.These cells exhibit two primary polarization states:conventionally activated(M1)and...Microglia,originating from primitive macrophages in the yolk sac,serves as both immune system defenders and regulators of homeostasis.These cells exhibit two primary polarization states:conventionally activated(M1)and alternatively activated(M2).The polarization of microglia plays a crucial role in influencing inflammatory disorders,metabolic imbalances,and neural degeneration.This process is implicated in various aspects of ocular diseases,especially age-related macular degeneration(AMD),including inflammation,oxidative stress and pathological angiogenesis.The distinct functional phenotypes of microglia impact disease progression and prognosis.Thus,regulating the polarization or functional phenotype of microglia at different stages of AMD holds promise for personalized therapeutic approaches.This comprehensive review outlines the involvement of microglia polarization in both physiological and pathological conditions,emphasizing its relevance in AMD.The discussion underscores the potential of polarization as a foundation for personalized treatment strategies for AMD.展开更多
Objective To investigate the antidepressant effects of Yuanzhi(Polygalae Radix;PR)aqueous extract on chronic unpredictable mild stress(CUMS)-induced depression rat models and the underlying mechanisms.Methods A total ...Objective To investigate the antidepressant effects of Yuanzhi(Polygalae Radix;PR)aqueous extract on chronic unpredictable mild stress(CUMS)-induced depression rat models and the underlying mechanisms.Methods A total of 40 male Sprague Dawley(SD)rats were randomly divided into control;model;low dose of PR(PR-L;0.5 g/kg);high dose of PR(PR-H;1 g/kg);and fluoxetine(10 mg/kg)groups;with 8 rats in each group.Except for the rats in control group;those in the other four groups underwent CUMS-induced depression modeling.PR and fluoxetine were administered intragastrically once daily;30 min prior to the CUMS procedure;for 14 consecu-tive days until the behavioral tests were performed.After CUMS modeling;the sucrose prefer-ence test(SPT);open field test(OFT);novelty-suppressed feeding test(NSFT);forced swim test(FST);and tail suspension test(TST)were employed to assess the pharmacological ef-fects of PR on the mitigation of depressive-like behaviors in rat models.Additionally;the en-zyme-linked immunosorbent assay(ELISA)was utilized to quantify the serum levels of tumor necrosis factor(TNF)-α;interleukin(IL)-6;and IL-1βin the rats.Western blot analysis was al-so conducted to evaluate the protein expression levels of nuclear factor kappa-B(NF-κB);in-ducible nitric oxide synthase(iNOS);cyclooxygenase-2(COX-2);nucleotide-binding oligomerization domain(NOD)-like receptor family pyrin domain containing 3(NLRP3);apoptosis-associated speck-like protein containing caspase recruitment domain(ASC);and caspase-1 in the hippocampal tissues of the rats.Immunofluorescence staining was per-formed to observe the morphological changes in ionized calcium-binding adapter molecule 1 positive(Iba-1+)cells in the dentate gyrus(DG)of rats with CUMS-induced depression.Results(i)Treatment with PR-H and fluoxetine resulted in significant enhancements in both the total distance and time the rats moved during tests(P<0.01 and P<0.05;respectively).Post-administration of PR-H and fluoxetine also led to statistically significant increase in su-crose preference among rats(P<0.05).Besides;PR-L;PR-H;and fluoxetine treatment markedly decreased the latency of ingestion(P<0.05;P<0.05;and P<0.01;respectively).As observed from the FST;PR-L;PR-H;and fluoxetine presented antidepressant effects on rats with CUMS-induced depression;leading to the reduction in time of their immobility(P<0.05;P<0.01;and P<0.01;respectively).The results of TST indicated reduced immobility time in rats receiving PR-H and fluoxetine treatment as well(P<0.01).(ii)Rats in model group showed an increase in the levels of Iba-1+microglia in their left and right brains in compari-son with control group(P<0.01).However;such increase was negated post PR treatment(P<0.01).Treatment with PR-L;PR-H;and fluoxetine considerably reduced the levels of inflam-matory factors(TNF-α;IL-1β;and IL-6;P<0.01).In addition;treatment of PR-L and PR-H ef-fectively counteracted the elevated levels of NLRP3;ASC;and caspase-1;and markedly down-regulated the expression levels of phosphorylated p65(p-p65);COX-2;and iNOS in rats’hip-pocampus(P<0.01).Conclusion Collectively;these findings indicate that PR exerts an antidepressant effect on rats with CUMS-induced depression partially through the modulation of the NLRP3 and NF-κB signaling pathways.展开更多
In the research, changes of apple chemistry, and molecule, under stresses, are n terms of morphology, physiology, bio- illustrated and research and identifica- tion methods of apple resistance are explored involving ...In the research, changes of apple chemistry, and molecule, under stresses, are n terms of morphology, physiology, bio- illustrated and research and identifica- tion methods of apple resistance are explored involving drought-resistance, flood-re- sistance, salt-stress resistance, cold-hardiness and heat-resistance. In addition prospects of apple resistance research are proposed, as well.展开更多
An immunosuppressive animal model induced by physical stress that forced mice to swim in cold water(14±1℃)and the restorative effect of Tremella polysac charide(TP)on the suppressed immune function by stress wer...An immunosuppressive animal model induced by physical stress that forced mice to swim in cold water(14±1℃)and the restorative effect of Tremella polysac charide(TP)on the suppressed immune function by stress were studied in mice.It was found that the spleen plaque forming cell(PFC)response to sheep red blood cells,delayed cuta- neous hypersensitivity(DCH)induced by dinitrochlorobenzene and the lymphocyte prolifer- ation stimulated by concanavalin A(Con A)were significantly decreased in stressed mice. In addition.the maximal decrease of PFC was reached in 9-12 days after stress.A- drenolectomy could not affect the decrease of PFC in stressed mice.TP(200.400mg/kg) ig for 8-14 days significantly restored the PFC.DCH and lymphocyte proliferation to nor- mal level in stressed mice.展开更多
Using Harrison's model and anisotropic parabolic approximation,the band structure of In1- x- y Gay Alx As compressively strained quantum wells is calculated.To design lasers with1.55μm wavelength,it is necessary...Using Harrison's model and anisotropic parabolic approximation,the band structure of In1- x- y Gay Alx As compressively strained quantum wells is calculated.To design lasers with1.55μm wavelength,it is necessary to an- alyze the well width,differential gain,transparency carrier density and the characteristic gain for an arbitrary com- position.Some useful empirical formulas are also presented.展开更多
Vibrator excitation generates not only reflections and refractions of wave fields on the subsurface interfaces but also electromagnetic waves with different frequencies. In this paper, we address the vibration-induced...Vibrator excitation generates not only reflections and refractions of wave fields on the subsurface interfaces but also electromagnetic waves with different frequencies. In this paper, we address the vibration-induced effects on the spontaneous potential field. The effects of controllable vibration on the spontaneous potential field were studied under real field geologic conditions. Experimental data confirmed that the vibration-induced effects on the spontaneous potential field do exist under field conditions. Monitoring records over a long time interval showed that there exist three information zones in the vibration-induced effects on the spontaneous potential field. These are the signal-varying zone, the extremestable zone, and the relaxation-recovery zone. Combined with different well-site data, it was concluded that the time-varying features of the anomalies in the information zones was closely related to the properties of the subsurface liquid (oil and water).展开更多
Uniaxial compressive experiments of ultrafine-grained Al fabricated by equal channel angular pressing(ECAP) method were performed at wide temperature and strain rate range. The influence of temperature on flow stress,...Uniaxial compressive experiments of ultrafine-grained Al fabricated by equal channel angular pressing(ECAP) method were performed at wide temperature and strain rate range. The influence of temperature on flow stress, strain hardening rate and strain rate sensitivity was investigated experimentally. The results show that both the effect of temperature on flow stress and its strain rate sensitivity of ECAPed Al is much larger than those of the coarse-grained Al. The temperature sensitivity of ultrafine-grained Al is comparatively weaker than that of the coarse-grained Al. Based on the experimental results, the apparent activation volume was estimated at different temperatures and strain rates. The forest dislocation interactions is the dominant thermally activated mechanism for ECAPed Al compressed at quasi-static strain rates, while the viscous drag plays an important role at high strain rates.展开更多
The coil-to-globule transition of thermally sensitive linear poly(N-isopropylacrylamide) (PNIPAM) labeled with dansyl group is induced by 1.54 μm laser pulses (widths10 ns). The dansyl group is used to follow t...The coil-to-globule transition of thermally sensitive linear poly(N-isopropylacrylamide) (PNIPAM) labeled with dansyl group is induced by 1.54 μm laser pulses (widths10 ns). The dansyl group is used to follow the transition kinetics because its fluorescence intensity is very sensitive to its micro-environment. As the molar ratio of NIPAM monomer to dansyl group increases from 110 to 300, the effect of covalently attached dansyl fluorophores on the transition decreases. In agreement with our previous study in which we used 8-anilino- l-naphthalensulfonic acid ammonium salt free in water as a fluorescent probe, the current study reveals that the transition has two distinct stages with two characteristic times, namely, Tfast≈0.1 ms, which can be attributed to the nucleation and formation of some "pearls" (locally contracting segments) on the chain, and tslow≈0.5 ms, which is related to the merging and coarsening of the "pearls".Tfast is independent of the PNIPAM chain length over a wide range (Mw=2.8× 10^6-4.2 × 10^7 g/mol). On the other hand, Tslow only slightly increases with the chain length.展开更多
Liver regeneration is a complex and well-orchestrated process,during which hepatic cells are activated to produce large signal molecules in response to liver injury or mass reduction.These signal molecules,in turn,set...Liver regeneration is a complex and well-orchestrated process,during which hepatic cells are activated to produce large signal molecules in response to liver injury or mass reduction.These signal molecules,in turn,set up the connections and cross-talk among liver cells to promote hepatic recovery.In this review,we endeavor to summarize the network of signal molecules that mediates hepatic cell communication in the regulation of liver regeneration.展开更多
Transient stress-induced cardiomyopathies have been increasingly recognized and while rare,they tend to affect elderly women more than other demographic groups.One type,often called tako-tsubo cardiomyopathy (TTC),i...Transient stress-induced cardiomyopathies have been increasingly recognized and while rare,they tend to affect elderly women more than other demographic groups.One type,often called tako-tsubo cardiomyopathy (TTC),is typically triggered by significant emotional or physical stress and is associated with chest pain,electrocardiogram (ECG) changes and abnormal cardiac enzymes.Significant left ventricular regional wall motion abnormalities usually include an akinetic "ballooning" apex with normal or hyperdynamic function of the base.A second type,often called neurogenic stunned myocardium,typically associated with subarachnoid hemorrhage,also usually presents with ECG changes and positive enzymes,but the typical wall motion abnormalities seen include normal basal and apical left ventricular contraction with akinesis of the mid-cavity in a circumferential fashion.The pathophysiology,clinical care and typical courses,are reviewed.展开更多
The effects of natural fish oil, DHA oil and soybean lecithin in microparticulate diets on stress tolerance of larval gilthead seabream ( Sparus aurata ) were investigated after 15 days feeding trials. The tolerance o...The effects of natural fish oil, DHA oil and soybean lecithin in microparticulate diets on stress tolerance of larval gilthead seabream ( Sparus aurata ) were investigated after 15 days feeding trials. The tolerance of larval gilthead seabream to various stress factors such as exposure to air ( lack of dissolved oxygen), changes in water temperature (low) and salinity ( high) were determined. This study showed that microparticulate diet with natural fish oil and soybean lecithin was the most effective for increasing the tolerance of larval gilthead seabream to various stresses, and that microparticulate diet with natural fish oil and palmitic acid (16:0) was more effective than microparticulate diet with DHA oil and soybean lecithin.展开更多
Stress-induced cardiomyopathy, also known as Takotsubo cardiomyopathy and left ventricular apical ballooning syndrome, is characterized by transient systolic dysfunction of the apical and mid-segments of the left vent...Stress-induced cardiomyopathy, also known as Takotsubo cardiomyopathy and left ventricular apical ballooning syndrome, is characterized by transient systolic dysfunction of the apical and mid-segments of the left ventricle with the abscence of coronary occlusion, This disease typically occurs in postmenopausal women of an advanced age after emotional or physical stress. Although the prognosis is generally favorable, acute fatal complications have been reported in a small subset of patients. Some patients died with acute cardiac complications, on the other hand, other patients died with underlying critical illness which triggered stress-induced cardiomyopathy.展开更多
As emerging artificial biomimetic membranes, smart or intelligent membranes that are able to respond to environmental stimuli are attracting ever-increasing interests from various fields. Their permeation properties i...As emerging artificial biomimetic membranes, smart or intelligent membranes that are able to respond to environmental stimuli are attracting ever-increasing interests from various fields. Their permeation properties including hydraulic permeability and diffusional permeability can be dramatically controlled or adjusted self-regulatively in response to small chemical and/or physical stimuli in their environments. Such environmental stimuli-responsive smart membranes could find myriad applications in numerous fields ranging from controlled release to separations. Here the trans-membrane mass-transfer and membrane separation is introduced as the beginning to initiate the requirement of smart membranes, and then bio-inspired design of environmental stimuli-responsive smart membranes and four essential elements for smart membranes are introduced and discussed. Next, smart membrane types and their applications as smart tools for controllable mass-transfer in controlled release and separations are reviewed. The research tooics in the near future are also suggested.展开更多
To understand mercury (Hg) toxicity in marine fish, we measured Hg accumulation in juvenile Japanese flounder (Paralichthys olivaceus) and assessed the effects on growth and antioxidant responses. After Hg exposu...To understand mercury (Hg) toxicity in marine fish, we measured Hg accumulation in juvenile Japanese flounder (Paralichthys olivaceus) and assessed the effects on growth and antioxidant responses. After Hg exposure (control, 5, 40, and 160 gg/L Hg) for 28 d, fish growth was significantly reduced. The accumulation of Hg in fish was dose-dependent and tissue-specific, with the maximum accumulation in kidney and liver, followed by gills, hone, and muscle. Different antioxidants responded differently to Hg exposure to cope with the induction of lipid peroxidation (LPO), which was also tissue-specific and dose- dependent. As Hg concentration increased, superoxide dismutase (SOD) and catalase (CAT) activities increased significantly, whereas glutathione S-transferase (GST) activity and glutathione (GSH) levels decreased significantly in the gills. SOD and glutathione peroxidase (GPx) activities and the GSH level increased significantly in the liver. SOD activity and GSH levels increased significantly, but CAT activity decreased significantly with an increase in Hg concentration in the kidney. LPO was induced significantly by elevated Hg in the gills and kidney but was least affected in the liver. Therefore, oxidative stress biomarkers in gills were more sensitive than those in the liver and kidney to Hg exposure. Thus, the gills have potential as bioindicators for evaluating Hg toxicity in juvenile flounder.展开更多
AIM:To evaluate the effect of chronic mild stress(CMS) on the emergence of gastric ulcers and possible modulation by octreotide,a synthetic somatostatin analogue. METHODS:Adult male Wistar rats were subjected to nine ...AIM:To evaluate the effect of chronic mild stress(CMS) on the emergence of gastric ulcers and possible modulation by octreotide,a synthetic somatostatin analogue. METHODS:Adult male Wistar rats were subjected to nine different unpredictable random stress procedures for 21 d,a multifactorial interactional animal model for CMS.Octreotide was administered daily for 21 d at two dose levels(50 and 90μg/kg)before exposure to stress procedure.Macro-and microscopical assessments were made,in addition to quantification of plasma corticosterone and gastric mucosal inflammatory,oxidative stress, and apoptotic biomarkers. RESULTS:Exposure to CMS elevated plasma corticosterone(28.3±0.6μg/dL,P=0.002),an event that was accompanied by gastric lesions(6.4±0.16 mm,P=0.01) and confirmed histopathologically.Moreover,the insult elevated gastric mucosal lipid peroxides(13±0.5 nmol/g tissue,P=0.001),tumor necrosis factor-α(3008.6±78.18 pg/g tissue,P<0.001),prostaglandin E2(117.1 ±4.31 pg/g tissue,P=0.002),and caspase-3 activity (2.4±0.14 OD/mg protein,P=0.002).Conversely,CMS mitigated interleukin-10(627.9±12.82 pg/g tissue,P= 0.001).Furthermore,in animals exposed to CMS,octreotide restored plasma corticosterone(61%and 71%from CMS,P=0.002)at both dose levels.These beneficial effects were associated with a remarkable suppression of gastric lesions(38%and 9%from CMS,P=0.01)and reversal of derangements in gastric mucosa. CONCLUSION:The current investigation provides evidence that exposure to CMS induces gastric ulceration, which was alleviated by administration of octreotide possibly possessing antioxidant,anti-inflammatory,and anti-apoptotic actions.展开更多
Stimuli-responsive polymer gels have recently attracted great attention due to their heat/solvent resistance,dimensional stability,and unique sensitivity to external stimuli.In this work,we synthesized thiol-functiona...Stimuli-responsive polymer gels have recently attracted great attention due to their heat/solvent resistance,dimensional stability,and unique sensitivity to external stimuli.In this work,we synthesized thiol-functionalized tetraphenylethylene(TPE)and constructed polymer gels through thiol-ene click reaction.The synthetic process of the polymer gels could be monitored by fluorescence emission of TPE moieties based on aggregation-induced emission mechanism.In addition,due to the dual redox-and acid responsiveness of the polymer gels,in the presence of dithiothreitol and trifluoroacetic acid,fluorescence quenching of the polymer gels can be observed.This stimuli-responsive characteristics endows the polymer gels with potential applications in fluorescent sensing and imaging,cancer diagnosis and selfhealing materials.展开更多
Mast cells (MC) are pivotal elements in several physiological and immunological functions of the gastro- intestinal (GI) tract. MC translate the stress signals that has been transmitted through brain gut axis into rel...Mast cells (MC) are pivotal elements in several physiological and immunological functions of the gastro- intestinal (GI) tract. MC translate the stress signals that has been transmitted through brain gut axis into release of proinflammatory mediators that can cause stimulation of nerve endings that could affect afferent nerve terminals and change their perception, affect intestinal motility, increase intestinal hyperpermeability and, in susceptible individuals, modulate the inflammation. Thus, it is not surprising that MC are an important element in the pathogenesis of inflammatory bowel disease and non inflammatory GI disorders such as IBS and mast cell enterocolitis.展开更多
Hydrogels show versatile properties and are of great interest in the fields of bioelectronics and tissue engineering.Understanding the dynamics of the water molecules trapped in the three-dimensional polymeric network...Hydrogels show versatile properties and are of great interest in the fields of bioelectronics and tissue engineering.Understanding the dynamics of the water molecules trapped in the three-dimensional polymeric networks of the hydrogels is crucial to elucidate their mechanical and swelling properties at the molecular level.In this report,the poly(DMAEMA-co-AA)hydrogels were synthesized and characterized by the macroscopic swelling measurements under different pH conditions.Furthermore,the microscopic structural dynamics of pH stimulus-responsive hydrogels were studied using FTIR and ultrafast IR spectroscopies from the viewpoint of the SCN-anionic solute as the local vibrational reporter.Ultrafast IR spectroscopic measurements showed the time constants of the vibrational population decay of SCN-were increased from 14±1 ps to 20±1 ps when the pH of the hydrogels varied from2.0 to 12.0.Rotational anisotropy measurements further revealed that the rotation of SCNanionic probe was restricted by the three-dimensional network formed in the hydrogels and the rotation of SCN-anionic probe cannot decay to zero especially at the pH of 7.0.These results are expected to provide a molecular-level understanding of the microscopic structure of the cross-linked polymeric network in the pH stimulus-responsive hydrogels.展开更多
文摘Microglia,originating from primitive macrophages in the yolk sac,serves as both immune system defenders and regulators of homeostasis.These cells exhibit two primary polarization states:conventionally activated(M1)and alternatively activated(M2).The polarization of microglia plays a crucial role in influencing inflammatory disorders,metabolic imbalances,and neural degeneration.This process is implicated in various aspects of ocular diseases,especially age-related macular degeneration(AMD),including inflammation,oxidative stress and pathological angiogenesis.The distinct functional phenotypes of microglia impact disease progression and prognosis.Thus,regulating the polarization or functional phenotype of microglia at different stages of AMD holds promise for personalized therapeutic approaches.This comprehensive review outlines the involvement of microglia polarization in both physiological and pathological conditions,emphasizing its relevance in AMD.The discussion underscores the potential of polarization as a foundation for personalized treatment strategies for AMD.
基金International Cooperative Project of Traditional Chinese Medicine(GZYYG2020023)CAMS Innovation Fund for Medical Sciences(CIFMS)Grant(2021-I2M-1-034)Key Research Project of Hunan Province(222SK2018).
文摘Objective To investigate the antidepressant effects of Yuanzhi(Polygalae Radix;PR)aqueous extract on chronic unpredictable mild stress(CUMS)-induced depression rat models and the underlying mechanisms.Methods A total of 40 male Sprague Dawley(SD)rats were randomly divided into control;model;low dose of PR(PR-L;0.5 g/kg);high dose of PR(PR-H;1 g/kg);and fluoxetine(10 mg/kg)groups;with 8 rats in each group.Except for the rats in control group;those in the other four groups underwent CUMS-induced depression modeling.PR and fluoxetine were administered intragastrically once daily;30 min prior to the CUMS procedure;for 14 consecu-tive days until the behavioral tests were performed.After CUMS modeling;the sucrose prefer-ence test(SPT);open field test(OFT);novelty-suppressed feeding test(NSFT);forced swim test(FST);and tail suspension test(TST)were employed to assess the pharmacological ef-fects of PR on the mitigation of depressive-like behaviors in rat models.Additionally;the en-zyme-linked immunosorbent assay(ELISA)was utilized to quantify the serum levels of tumor necrosis factor(TNF)-α;interleukin(IL)-6;and IL-1βin the rats.Western blot analysis was al-so conducted to evaluate the protein expression levels of nuclear factor kappa-B(NF-κB);in-ducible nitric oxide synthase(iNOS);cyclooxygenase-2(COX-2);nucleotide-binding oligomerization domain(NOD)-like receptor family pyrin domain containing 3(NLRP3);apoptosis-associated speck-like protein containing caspase recruitment domain(ASC);and caspase-1 in the hippocampal tissues of the rats.Immunofluorescence staining was per-formed to observe the morphological changes in ionized calcium-binding adapter molecule 1 positive(Iba-1+)cells in the dentate gyrus(DG)of rats with CUMS-induced depression.Results(i)Treatment with PR-H and fluoxetine resulted in significant enhancements in both the total distance and time the rats moved during tests(P<0.01 and P<0.05;respectively).Post-administration of PR-H and fluoxetine also led to statistically significant increase in su-crose preference among rats(P<0.05).Besides;PR-L;PR-H;and fluoxetine treatment markedly decreased the latency of ingestion(P<0.05;P<0.05;and P<0.01;respectively).As observed from the FST;PR-L;PR-H;and fluoxetine presented antidepressant effects on rats with CUMS-induced depression;leading to the reduction in time of their immobility(P<0.05;P<0.01;and P<0.01;respectively).The results of TST indicated reduced immobility time in rats receiving PR-H and fluoxetine treatment as well(P<0.01).(ii)Rats in model group showed an increase in the levels of Iba-1+microglia in their left and right brains in compari-son with control group(P<0.01).However;such increase was negated post PR treatment(P<0.01).Treatment with PR-L;PR-H;and fluoxetine considerably reduced the levels of inflam-matory factors(TNF-α;IL-1β;and IL-6;P<0.01).In addition;treatment of PR-L and PR-H ef-fectively counteracted the elevated levels of NLRP3;ASC;and caspase-1;and markedly down-regulated the expression levels of phosphorylated p65(p-p65);COX-2;and iNOS in rats’hip-pocampus(P<0.01).Conclusion Collectively;these findings indicate that PR exerts an antidepressant effect on rats with CUMS-induced depression partially through the modulation of the NLRP3 and NF-κB signaling pathways.
基金Supported by Shandong Provincial Natural Science Foundation in China(ZR2011CM034)~~
文摘In the research, changes of apple chemistry, and molecule, under stresses, are n terms of morphology, physiology, bio- illustrated and research and identifica- tion methods of apple resistance are explored involving drought-resistance, flood-re- sistance, salt-stress resistance, cold-hardiness and heat-resistance. In addition prospects of apple resistance research are proposed, as well.
文摘An immunosuppressive animal model induced by physical stress that forced mice to swim in cold water(14±1℃)and the restorative effect of Tremella polysac charide(TP)on the suppressed immune function by stress were studied in mice.It was found that the spleen plaque forming cell(PFC)response to sheep red blood cells,delayed cuta- neous hypersensitivity(DCH)induced by dinitrochlorobenzene and the lymphocyte prolifer- ation stimulated by concanavalin A(Con A)were significantly decreased in stressed mice. In addition.the maximal decrease of PFC was reached in 9-12 days after stress.A- drenolectomy could not affect the decrease of PFC in stressed mice.TP(200.400mg/kg) ig for 8-14 days significantly restored the PFC.DCH and lymphocyte proliferation to nor- mal level in stressed mice.
文摘Using Harrison's model and anisotropic parabolic approximation,the band structure of In1- x- y Gay Alx As compressively strained quantum wells is calculated.To design lasers with1.55μm wavelength,it is necessary to an- alyze the well width,differential gain,transparency carrier density and the characteristic gain for an arbitrary com- position.Some useful empirical formulas are also presented.
文摘Vibrator excitation generates not only reflections and refractions of wave fields on the subsurface interfaces but also electromagnetic waves with different frequencies. In this paper, we address the vibration-induced effects on the spontaneous potential field. The effects of controllable vibration on the spontaneous potential field were studied under real field geologic conditions. Experimental data confirmed that the vibration-induced effects on the spontaneous potential field do exist under field conditions. Monitoring records over a long time interval showed that there exist three information zones in the vibration-induced effects on the spontaneous potential field. These are the signal-varying zone, the extremestable zone, and the relaxation-recovery zone. Combined with different well-site data, it was concluded that the time-varying features of the anomalies in the information zones was closely related to the properties of the subsurface liquid (oil and water).
基金Projects(11272267,11102168,10932008)supported by the National Natural Science Foundation of ChinaProject(B07050)supported by Northwestern Polytechnical University
文摘Uniaxial compressive experiments of ultrafine-grained Al fabricated by equal channel angular pressing(ECAP) method were performed at wide temperature and strain rate range. The influence of temperature on flow stress, strain hardening rate and strain rate sensitivity was investigated experimentally. The results show that both the effect of temperature on flow stress and its strain rate sensitivity of ECAPed Al is much larger than those of the coarse-grained Al. The temperature sensitivity of ultrafine-grained Al is comparatively weaker than that of the coarse-grained Al. Based on the experimental results, the apparent activation volume was estimated at different temperatures and strain rates. The forest dislocation interactions is the dominant thermally activated mechanism for ECAPed Al compressed at quasi-static strain rates, while the viscous drag plays an important role at high strain rates.
文摘The coil-to-globule transition of thermally sensitive linear poly(N-isopropylacrylamide) (PNIPAM) labeled with dansyl group is induced by 1.54 μm laser pulses (widths10 ns). The dansyl group is used to follow the transition kinetics because its fluorescence intensity is very sensitive to its micro-environment. As the molar ratio of NIPAM monomer to dansyl group increases from 110 to 300, the effect of covalently attached dansyl fluorophores on the transition decreases. In agreement with our previous study in which we used 8-anilino- l-naphthalensulfonic acid ammonium salt free in water as a fluorescent probe, the current study reveals that the transition has two distinct stages with two characteristic times, namely, Tfast≈0.1 ms, which can be attributed to the nucleation and formation of some "pearls" (locally contracting segments) on the chain, and tslow≈0.5 ms, which is related to the merging and coarsening of the "pearls".Tfast is independent of the PNIPAM chain length over a wide range (Mw=2.8× 10^6-4.2 × 10^7 g/mol). On the other hand, Tslow only slightly increases with the chain length.
文摘Liver regeneration is a complex and well-orchestrated process,during which hepatic cells are activated to produce large signal molecules in response to liver injury or mass reduction.These signal molecules,in turn,set up the connections and cross-talk among liver cells to promote hepatic recovery.In this review,we endeavor to summarize the network of signal molecules that mediates hepatic cell communication in the regulation of liver regeneration.
文摘Transient stress-induced cardiomyopathies have been increasingly recognized and while rare,they tend to affect elderly women more than other demographic groups.One type,often called tako-tsubo cardiomyopathy (TTC),is typically triggered by significant emotional or physical stress and is associated with chest pain,electrocardiogram (ECG) changes and abnormal cardiac enzymes.Significant left ventricular regional wall motion abnormalities usually include an akinetic "ballooning" apex with normal or hyperdynamic function of the base.A second type,often called neurogenic stunned myocardium,typically associated with subarachnoid hemorrhage,also usually presents with ECG changes and positive enzymes,but the typical wall motion abnormalities seen include normal basal and apical left ventricular contraction with akinesis of the mid-cavity in a circumferential fashion.The pathophysiology,clinical care and typical courses,are reviewed.
文摘The effects of natural fish oil, DHA oil and soybean lecithin in microparticulate diets on stress tolerance of larval gilthead seabream ( Sparus aurata ) were investigated after 15 days feeding trials. The tolerance of larval gilthead seabream to various stress factors such as exposure to air ( lack of dissolved oxygen), changes in water temperature (low) and salinity ( high) were determined. This study showed that microparticulate diet with natural fish oil and soybean lecithin was the most effective for increasing the tolerance of larval gilthead seabream to various stresses, and that microparticulate diet with natural fish oil and palmitic acid (16:0) was more effective than microparticulate diet with DHA oil and soybean lecithin.
文摘Stress-induced cardiomyopathy, also known as Takotsubo cardiomyopathy and left ventricular apical ballooning syndrome, is characterized by transient systolic dysfunction of the apical and mid-segments of the left ventricle with the abscence of coronary occlusion, This disease typically occurs in postmenopausal women of an advanced age after emotional or physical stress. Although the prognosis is generally favorable, acute fatal complications have been reported in a small subset of patients. Some patients died with acute cardiac complications, on the other hand, other patients died with underlying critical illness which triggered stress-induced cardiomyopathy.
基金Supported by the National Basic Research Program of China (2009CB623407), and the National Natural Science Foundation of China (20825622, 20806049, 20906064, 20990220, 21036002, 21076127, 21136006).
文摘As emerging artificial biomimetic membranes, smart or intelligent membranes that are able to respond to environmental stimuli are attracting ever-increasing interests from various fields. Their permeation properties including hydraulic permeability and diffusional permeability can be dramatically controlled or adjusted self-regulatively in response to small chemical and/or physical stimuli in their environments. Such environmental stimuli-responsive smart membranes could find myriad applications in numerous fields ranging from controlled release to separations. Here the trans-membrane mass-transfer and membrane separation is introduced as the beginning to initiate the requirement of smart membranes, and then bio-inspired design of environmental stimuli-responsive smart membranes and four essential elements for smart membranes are introduced and discussed. Next, smart membrane types and their applications as smart tools for controllable mass-transfer in controlled release and separations are reviewed. The research tooics in the near future are also suggested.
基金Supported by the National Natural Science Foundation of China for Creative Research Groups (No. 41121064)the National High Technology Research and Development Program of China (863 Program) (No.2009AA09Z401)+1 种基金the Knowledge Innovation Program of Chinese Academy of Sciences (No. KZCX2-YW-Q07-02)the Public Interest Research Program in Marine Industry from the State Oceanic Administration of China (No. 200905019)
文摘To understand mercury (Hg) toxicity in marine fish, we measured Hg accumulation in juvenile Japanese flounder (Paralichthys olivaceus) and assessed the effects on growth and antioxidant responses. After Hg exposure (control, 5, 40, and 160 gg/L Hg) for 28 d, fish growth was significantly reduced. The accumulation of Hg in fish was dose-dependent and tissue-specific, with the maximum accumulation in kidney and liver, followed by gills, hone, and muscle. Different antioxidants responded differently to Hg exposure to cope with the induction of lipid peroxidation (LPO), which was also tissue-specific and dose- dependent. As Hg concentration increased, superoxide dismutase (SOD) and catalase (CAT) activities increased significantly, whereas glutathione S-transferase (GST) activity and glutathione (GSH) levels decreased significantly in the gills. SOD and glutathione peroxidase (GPx) activities and the GSH level increased significantly in the liver. SOD activity and GSH levels increased significantly, but CAT activity decreased significantly with an increase in Hg concentration in the kidney. LPO was induced significantly by elevated Hg in the gills and kidney but was least affected in the liver. Therefore, oxidative stress biomarkers in gills were more sensitive than those in the liver and kidney to Hg exposure. Thus, the gills have potential as bioindicators for evaluating Hg toxicity in juvenile flounder.
文摘AIM:To evaluate the effect of chronic mild stress(CMS) on the emergence of gastric ulcers and possible modulation by octreotide,a synthetic somatostatin analogue. METHODS:Adult male Wistar rats were subjected to nine different unpredictable random stress procedures for 21 d,a multifactorial interactional animal model for CMS.Octreotide was administered daily for 21 d at two dose levels(50 and 90μg/kg)before exposure to stress procedure.Macro-and microscopical assessments were made,in addition to quantification of plasma corticosterone and gastric mucosal inflammatory,oxidative stress, and apoptotic biomarkers. RESULTS:Exposure to CMS elevated plasma corticosterone(28.3±0.6μg/dL,P=0.002),an event that was accompanied by gastric lesions(6.4±0.16 mm,P=0.01) and confirmed histopathologically.Moreover,the insult elevated gastric mucosal lipid peroxides(13±0.5 nmol/g tissue,P=0.001),tumor necrosis factor-α(3008.6±78.18 pg/g tissue,P<0.001),prostaglandin E2(117.1 ±4.31 pg/g tissue,P=0.002),and caspase-3 activity (2.4±0.14 OD/mg protein,P=0.002).Conversely,CMS mitigated interleukin-10(627.9±12.82 pg/g tissue,P= 0.001).Furthermore,in animals exposed to CMS,octreotide restored plasma corticosterone(61%and 71%from CMS,P=0.002)at both dose levels.These beneficial effects were associated with a remarkable suppression of gastric lesions(38%and 9%from CMS,P=0.01)and reversal of derangements in gastric mucosa. CONCLUSION:The current investigation provides evidence that exposure to CMS induces gastric ulceration, which was alleviated by administration of octreotide possibly possessing antioxidant,anti-inflammatory,and anti-apoptotic actions.
基金supported by the National Natural Science Foundation of China (No.51773190 and No.51973206)。
文摘Stimuli-responsive polymer gels have recently attracted great attention due to their heat/solvent resistance,dimensional stability,and unique sensitivity to external stimuli.In this work,we synthesized thiol-functionalized tetraphenylethylene(TPE)and constructed polymer gels through thiol-ene click reaction.The synthetic process of the polymer gels could be monitored by fluorescence emission of TPE moieties based on aggregation-induced emission mechanism.In addition,due to the dual redox-and acid responsiveness of the polymer gels,in the presence of dithiothreitol and trifluoroacetic acid,fluorescence quenching of the polymer gels can be observed.This stimuli-responsive characteristics endows the polymer gels with potential applications in fluorescent sensing and imaging,cancer diagnosis and selfhealing materials.
文摘Mast cells (MC) are pivotal elements in several physiological and immunological functions of the gastro- intestinal (GI) tract. MC translate the stress signals that has been transmitted through brain gut axis into release of proinflammatory mediators that can cause stimulation of nerve endings that could affect afferent nerve terminals and change their perception, affect intestinal motility, increase intestinal hyperpermeability and, in susceptible individuals, modulate the inflammation. Thus, it is not surprising that MC are an important element in the pathogenesis of inflammatory bowel disease and non inflammatory GI disorders such as IBS and mast cell enterocolitis.
基金supported by the National Natural Science Foundation of China(No.21873062)the Fundamental Research Funds for the Central Universities(GK202001009)+2 种基金the Natural Science Basis Research Plan in Shaanxi Province of China(No.2020JM-295)the 111 Project(B14041)Program for Changjiang Scholars and the Innovative Research Team in University(IRT-14R33)。
文摘Hydrogels show versatile properties and are of great interest in the fields of bioelectronics and tissue engineering.Understanding the dynamics of the water molecules trapped in the three-dimensional polymeric networks of the hydrogels is crucial to elucidate their mechanical and swelling properties at the molecular level.In this report,the poly(DMAEMA-co-AA)hydrogels were synthesized and characterized by the macroscopic swelling measurements under different pH conditions.Furthermore,the microscopic structural dynamics of pH stimulus-responsive hydrogels were studied using FTIR and ultrafast IR spectroscopies from the viewpoint of the SCN-anionic solute as the local vibrational reporter.Ultrafast IR spectroscopic measurements showed the time constants of the vibrational population decay of SCN-were increased from 14±1 ps to 20±1 ps when the pH of the hydrogels varied from2.0 to 12.0.Rotational anisotropy measurements further revealed that the rotation of SCNanionic probe was restricted by the three-dimensional network formed in the hydrogels and the rotation of SCN-anionic probe cannot decay to zero especially at the pH of 7.0.These results are expected to provide a molecular-level understanding of the microscopic structure of the cross-linked polymeric network in the pH stimulus-responsive hydrogels.