骨髓是各种组织器官再生修复的共同干细胞库

再生成年组织细胞的干细胞来源存在争论.成人组织干细胞的"跨系分化"或"可塑性"受到质疑.目前认为骨髓是储存各种原始组织干细胞的仓库:骨髓干细胞在各种细胞因子的作用下,不断通过毛细血管网进入各种组织,并在局部组织分化为原始组织干细胞;原始组织干细胞再生增殖组织特异性细胞以补充衰老损伤的细胞.由于骨髓干细胞能够自我更新,容易从骨髓及外周血获取,故对组织再生修复有着令人鼓舞的临床应用潜力.

Architectural Plasticity in Response to Soil Moisture in the Stoloniferous Herb, Duchesnea indica

Architectural plasticity of clonal plants may enhance exploitation of soil moisture heterogeneity by the plants. The plasticity of clonal architecture in response to soil moisture in the stoloniferous herb, Duchesnea indica Focke, was investigated in an experiment with different soil moisture contents as treatments, i.e. 40%, 60%, 80%, 100% of the maximum moisture content of soil (MMCS). As soil moisture content increased, the spacer length, ramet density, branching intensity and branching angle of D. indica plants changed by quadratic curve. And the optimum habitat for the plants was at 80% of the MMCS. This architectural plasticity in D. indica was simulated through the Dynamic Logistic Model. The imitative effect was statistically satisfactory. Its architectural plasticity observed here may allow the species to show foraging behavior in its habitat where soil moisture is patchily distributed.

Phenotypic Plasticity in Response to the Heterogeneous Water Supplyin the Rhizomatous Grass Species, Calamagrostis epigejosin the Mu Us Sandy Land of China

Calamagrostis epigejos (L.) Roth. is a perennial grass with slender and long rhizome segments between interconnected neighbor ramets. To investigate the phenotypic plasticity in response to the heterogeneous soil water supply, ramet pairs of the species were subjected to heterogeneous water supply by which either mother ramets or daughter ramets were in high or low soil water supply, respectively, in the Maowusu (Mu Us) Sandy Land of Nei Mongol. The results showed that the phenotypic characteristics of the individual ramets of C epigejos were greatly influenced by the heterogeneous water supply. The ramets treated with high water supply significantly produced more new rhizomes and more offspring (ramets), and accumulated more shoot biomass, and allocated more biomass to their shoots than those treated with low water supply. In comparison with the daughter ramets in homogeneous soil water supply, phenotypic characteristics, in terms of new rhizome growth, the production of new offspring, and the biomass allocation pattern, of the daughter ramets within the pairs of the species were not significantly changed, no matter that high or low soil water supply to mother ramets. The phenotypic responses of mother ramets to soil water supply were similar to those of daughter ramets. From these results, it is inferred that the interconnected ramets of C epigejos response phenotypically to their local soil water rather than to the soil water experienced by the interconnected ramets. The interconnected ramets of C epigejos might be independent of each other in water relationship, although they are physically interconnected with rhizome segments. The physiological independence of interconnected ramets might facilitate the risk spreading and thus enhance the genet survivorship under the frequent drought stresses in Mu Us Sandland.

Effect of Light Intensity and Nutrient Availability on Clonal Growth and Clonal Morphology of the Stoloniferous Herb Halerpestes ruthenica

In a greenhouse experiment plasticity of clonal growth and clonal morphology of the stoloniferous rosette herb Halerpestes nahenica Ovcz. in response to differing levels of light intensity and nutrient availability was studied. Total plant dry weight, leaf area of primary ramets, total number of ramets and of stolons, and total stolon length were significantly reduced, while specific internode length and specific petiole length significantly increased under deep shading (6.25% of high light intensity, 5.3% of full daylight) or under low nutrient availability. Under low nutrient availability, mean stolon internode length of H. ruthenica was significantly larger while branching intensity and number of ramets smaller than those under high nutrient availability. These responses are consistent with the foraging model of clonal plants, indicating that H. nahenica is able to forage nutrients through the plastic responses of clonal growth and clonal. morphology when it grows in heterogeneous environments. However, under deep shading, both mean stolon internode length and mean petiole length were significantly reduced, which disagrees with the findings of many other stoloniferous herbs in response to low or medium levels of shading (ca. 13%-75% of high light intensity, >10% of full daylight), suggesting that under deep shading stoloniferous herbs may not forage light through the plastic responses of spacer length. Many traits such as total plant dry weight, total number and length of stolons, total length of secondary and tertiary stolons. total number of ramets, leaf area of primary ramets and branching intensity were markedly influenced by the interaction effect of light intensity and nutrient availability. Under high light intensity nutrient availability affected these traits more pronouncedly, however under low light intensity nutrient availability either did not affect or affected less markedly on these traits, indicating that fight intensity had significant effect on nutrient foraging in H. nahenica. Under deep shading or low nutrient availability, H. ruthenica may increase its mean stolon internode length by means of thinning stolon internodes (i.e., an increase in specific internode length), which provides it with more chance to escape from resource-poor sites.

干细胞移植在心力衰竭治疗中的应用

干细胞是一具有自我更新和分化潜能的细胞,在一定条件下,可定向分化成机体内的功能细胞,形成任何类型的组织和器官,即具有"可塑性",包括胚胎干细胞和成体干细胞. 心力衰竭(心衰)是各种心血管疾病的严重终末阶段,被称为心脏病最后的"大战场".

肝细胞癌领域的新概念：从分子研究到临床实践（下）

HCC是一种“可塑性”的癌症？ 癌细胞分化、恶性程度变得更高的能力被称为“可塑性”，并且需要上皮一间叶样表型转化（EMT）——个通常在胚胎发生期和癌症发生中的多步骤过程。经过表型改变之后的细胞变得更加具有侵袭性和浸润性，就像已经在大肠癌中详细描述的那样。

Heterogeneity and plasticity of T helper cells

CD4 T helper （Th） cells play critical roles in adaptive immune responses. They recruit and activate other immune cells including B cells, CD8 T cells, macrophages, mast cells, neutrophils, eosinophils and basophils. Based on their functions, their pattern of cytokine secretion and their expression of specific transcription factors, Th cells, differentiated from naive CD4 T cells, are classified into four major lineages, Thl, Th2, Th17 and T regulatory （Treg） cells, although other Th lineages may exist. Subsets of the same lineage may express different effector cytokines, reside at different locations or give rise to cells with different fates, whereas cells from different lineages may secrete common cytokines, such as IL-2, IL-9 and IL-10, resulting in massive heterogeneity of the Th cell population. In addition, the pattern of cytokine secretion may switch from that of one lineage toward another under certain circumstances, suggesting that Th cells are plastic. Tregs are also more heterogeneous and plastic than were originally thought. In this review, we summarize recent reports on heterogeneity and plasticity of Th cells, and discuss potential mechanisms and implications of such features that Th cells display.

Evaluation of Blast-Resistant Performance Predicted by Damaged Plasticity Model for Concrete

in order to evaluate the capacity of reinforced concrete （RC） structures subjected to blast Ioadings, the damaged plasticity model for concrete was used in the analysis of the dynamic responses of blast-loaded RC structures, and all three failure modes were numerically simulated by the finite element software ABAQUS. Simulation results agree with the experimental observations. It is demonstrated that the damaged plasticity model for concrete in the finite element software ABAQUS can predict dynamic responses and typical flexure, flexure-shear and direct shear failure modes of the blast-loaded RC structures.

Differences in functional traits and reproductive allocations between native and invasive plants

Because co-occurring native and invasive plants are subjected to similar environmental selection pressures,the differences in functional traits and reproductive allocation strategies between native and invasive plants may be closely related to the success of the latter.Accordingly,this study examines differences in functional traits and reproductive allocation strategies between native and invasive plants in Eastern China.Plant height,branch number,reproductive branch number,the belowground-to-aboveground biomass ratio,and the reproductive allocation coefficient of invasive plants were all notably higher than those of native species.Additionally,the specific leaf area(SLA)values of invasive plants were remarkably lower than those of native species.Plasticity indexes of SLA,maximum branch angle,and branch number of invasive plants were each notably lower than those of native species.The reproductive allocation coefficient was positively correlated with reproductive branch number and the belowground-to-aboveground biomass ratio but exhibited negative correlations with SLA and aboveground biomass.Plant height,branch number,reproductive branch number,the belowground-to-aboveground biomass ratio,and the reproductive allocation coefficient of invasive plants may strongly influence the success of their invasions.

Effect of Nb on plasticity and oxidation behavior of TiAlNb intermetallic compound by density functional theory

Based on the pseudo potential plane-wave method of density functional theory （DFT）, Ti1-xNbxAk （x=0, 0.062 5, 0.083 3, 0.125, 0.250） crystals＇ geometry structure, elastic constants, electronic structure and Mulliken populations were calculated, and the effects of doping on the geometric structure, electronic structure and bond strength were systematically analyzed. The results show that the influence of Nb on the geometric structure is little in terms of the plasticity, and with the increase of Nb content, the covalent bond strength remarkably reduces, and Ti-Al, Nb-M （M=Ti, Al） and other hybrid bonds enhance; meanwhile, the peak district increases and the pseudo-energy gap first decreases and then increases, the overall band structure narrows, the covalent bond and direction of bonds reduce. The population analysis also shows that the results are consistent with the electronic structure analysis. The density of states of TiAINb shows that Nb doping can enhance the activity of Al and benefit the form of Al2O3 film. All the calculations reveal that the room temperature plasticity and the antioxidation properties of the compounds can be improved with the Nb content of 8.33%-12.5% （mole fraction）.

Alarm cue induces an antipredator morphological defense in juvenile Nicaragua cichlids Hypsophrys nicaraguensis

Olfactory cues that indicate predation risk elicit a number of defensive behaviors in fishes, but whether they are sufficient to also induce morphological defenses has received little attention. Cichlids are characterized by a high level of morphological plasticity during development, and the few species that have been tested do exhibit defensive behaviors when exposed to alarm cues released from the damaged skin of conspecifics. We utilized young juvenile Nicaragua cichlids Hypsophrys nicaraguensis to test if the perception of predation risk from alarm cue （conspecific skin extract） alone induces an increased relative body depth which is a defense against gape-limited predators. After two weeks of exposure, siblings that were exposed to conspecific alarm cue increased their relative body depth nearly double the amount of those exposed to distilled water （control） and zebrafish Danio rerio alarm cue. We repeated our measurements over the last two weeks （12 and 14） of cue exposure when the fish were late-stage juveniles to test if the rate of increase was sustained; there were no differences in final dimensions between the three treatments. Our results show that 1） the Nicaragua cichlid has an innate response to conspecific alarm cue which is not a generalized response to an injured fish, and 2） this innate recognition ultimately results in developing a deeper body at a stage of the life history where predation risk is high [Current Zoology 56 （1）： 36-42, 2010].

Comparative studies on phenotypic plasticity of two herbs,Changium smyrnioides and Anthriscus sylvestris

The endangered medicinal herb, Changium smyrnioides can only be found in deciduous forest gaps within the middle to northern subtropical broad-leaved evergreen forest zone of China. The considerable plasticity of its shoot and root structure helps it to capture light more effectively in winter and early spring, and to adapt to the soil moisture conditions in its narrow habitat. Another medicinal plant, Anthriscus sylvestris, is of similar economic importance but commonly distributed widely. In contrast to C. smyrnioides, it has low structural plasticity. It is also specialized to adapt to the moist and sunny environment, where habitat, such as the banks of creeks and rivers, is abundant.

Thermo-plasticity of high-strength and high-ductility 7050 aluminum ingot

Thermo-plasticity of homogenized 7050 aluminum ingot was investigated by instantaneous tensile tests conducted at different temperatures. The results show that, with the increase of testing temperatures, the strength decreases, and the plasticity increases firstly and then decreases in homogenized 7050 ingot. When the studied alloy is deformed between 380℃ and 420℃, the deformation resistance is lower and plasticity is better. And the actual heating temperature for ingot before hot extrusion should be controlled between 360 ~C and 400 ~C. At low tensile temperatures, the deformation structure is mainly composed of dislocation substructure. With the increase of testing temperatures, transgranular fracture transforms into intergranular fracture progressively during deformation. At high tensile temperatures, the grain boundaries are weakened, deformation is concentrated at the grain boundaries and the re-orientation of equilibrium phases at grain boundaries appears.

Simulation analysis of construction process of high rock slope's stabilization

A self-developed elasto-plastic finite element program was used to analyze the construction sequence of high rock slope's stabilization in a coal-coking plant, and the result was compared with that employing the ultimate equilibrium method. Based on the results of finite element analysis, the stress contour graphs and displacement vector graphs at different construction steps were obtained, and the behavior of the slope during stabilization construction process was analyzed quantitatively. Based on the analysis of safety factors of three different schemes of stabilization and two different construction schemes, the assessment of stability and bracing design of the construction process were performed. The results show that the original reinforcement design is improper; the stability of the rock slope is controlled by a developed structural plane, the stability factor after excavation is less than 1, and the free surface should be braced in time; for stability, the construction sequence should adopt that bracing follows excavation step by step up to down; the local slide occurred during the construction process agrees with the dangerous slide determined by the numerical analysis, which proves the validity and rationality of the adopted method.

Compound Chai Jin Jie Yu Tablets,Acts as An Antidepressant by Promoting Synaptic Function in the Hippocampal Neurons

Objective To investigate the effectiveness of compound Chai Jin Jie Yu Tablets(CJJYT)in ameliorating cognitive impairment associated with depression and its potential mechanism of action.Methods In vitro experiments,the hippocampus was isolated from the whole brain of the fetal rat and cultured into hippocampal neuron cells.50μM corticosterone(CORT)was added to each group 18 h before the experiment for modeling depression,with the exception of the control group.After modeling,the blank serum group was added with 10%blank serum,the CJJYT group and the venlafaxine group were added with the corresponding 10%drug-containing serum,and the control group and the model group were added with equal volumes of culture medium.The intracellular Ca^2+mean fluorescence intensity,miniature excitatory postsynaptic current(mEPSC)current amplitude,and frequency of different hippocampal neurons were evaluated as indicators of synaptic function in the hippocampal neurons.In addition,the expression of synaptic plasticity related proteins,synaptophysin-α(SYN-α),N-methyl-D-aspartate receptor 2A(NR2A),N-methyl-Daspartate receptor 2B(NR2B),post synaptic density 95 protein(PSD-95),calcium/calmodulin dependent protein kinaseⅡ(CaMKⅡ)and synaptic associated protein(SynGAP)were detected in the hippocampal neurons by immunofluorescence staining and high content analysis(HCA)system.Then,reverse transcription-polymerase chain reaction(RT-PCR)was used to detect the mRNA expression levels of SYN-α,NR2A,NR2B,PSD-95,CaMKⅡand SynGAP.For in vivo experiments,except for those in the blank control group,all rats were treated within a single cage for chronic unpredictable stress-induced depression modeling and subjected to corresponding drug interventions.Behavioral tests were used to detect depressive behavior and determine learning,memory and other cognitive abilities,whereas enzyme-linked immunosorbent assay(ELISA)was used to detect the CORT levels.Golgi-Cox staining was used to observe changes in the synaptic morphology of parahippocampal gyrus CA1 area(CA1)and dentategyrus(DG).Results In vitro,CJJYT treatment reduced the intracellular Ca^2+mean flurorescence intensity in the hippocampal neurons(P<0.05),causing a reduction in the frequency and current amplitude of mEPSC(P<0.05),and thus inhibited the excessive activation of post-synaptic receptors.CJJYT treatment reduced the protein and mRNA expression of SYN-α,NR2A,NR2B and PSD-95 in the hippocampal neurons(P<0.05),increased the mRNA and protein expression of CaMKⅡand SynGAP(P<0.05),and thereby improved the synaptic plasticity of the hippocampal neurons.In vivo,CJJYT intervention improved sucrose preference,voluntary activity,learning and memory ability of Morris water maze test,and suppressed appetite(P<0.05),and increased the despair feeling of forced swimming test(P<0.05).The CORT level was reduced(P<0.05),leading to the repair of synaptic damage in the hippocampal neurons.Conclusions CJJYT can improve the synaptic function of hippocampal neurons and has obvious protective effects on neurons.It can repair the structural damage in the hippocampal neurons,improving the cognitive ability of the depressed model rats.The mechanism of CJJYT improving cognition in depressed rats may be related to the transmission and function of SYN-α/NR and its downstream neurotransmitters.

Compound Chaijin Jieyu Tablets ameliorating insomnia complicated with depression by improving synaptic plasticity via regulating orexin A,melatonin,and acetylcholine contents

Objective To investigate the efficacy and mechanism of action of Compound Chaijin Jieyu Tablets(复方柴金解郁片,CCJJYT)in rats with insomnia complicated with depression.Methods Seventy-two Sprague-Dawley rats were randomly assigned into eight groups:the control,chronic unpredictable mild stress(CUMS),sleep deprivation(SD),CUMS+SD,positive drug(venlafaxine hydrochloride+diazepam),CCJJYT high-dose(CCJJYT˗2×),medium-dose(CCJJYT˗1×),and low-dose(CCJJYT˗0.5×)groups,with nine rats in each group.Depression-like behavior was evaluated by body weight,food intake,and behavioral tests such as the sucrose preference test(SPT),open field test(OFT),forced swimming test(FST),and pentobarbital-induced sleep test(PST).Hematoxylin-eosin(HE)staining and Golgi-Cox staining were used to observe changes in pathological tissue and synaptic morphology,respectively.Enzyme-linked immunosorbent assay(ELISA)was used to detect the contents of orexin-A and acetylcholine.The expression levels of orexin receptor 1(OXR1),melatonin receptor 1(MT1A),melatonin receptor 2(MT1B),acetylcholinesterase(AChE),and choline acetyltransferase(ChAT)were detected by immunohistochemistry and Western blot.Results In the present study,rats in the model group showed significant behavioral changes as well as a reduction in hippocampal dendritic branch length and synaptic number,along with increasing the content of orexin A and acetylcholine(P<0.05),and altered expression levels of OX1R,MT1A,MT1B,ChAT,and AChE in the hippocampus and prefrontal cortex after modeling(P<0.05).CCJJYT can improve depressive insomnia behavior and synaptic plasticity of rats(P<0.05),which is similar to that of the positive drug group.It can also decrease the content of orexin A and acetylcholine,and reduce the expression levels of OXR1 and ChAT in hippocampus and prefrontal cortex(P<0.05),and increase the expression levels of MT1A,MT1B,and AChE proteins(P<0.05).Conclusion CCJJYT has good antidepressant and insomnia effects,probably through the regulation of orexin-A,melatonin,and acetylcholine content in hippocampus and prefrontal cortex of rats,improving synaptic plasticity and thus exerting antidepressant and insomnia effects.

Using the endocannabinoid system as a neuroprotective strategy in perinatal hypoxic-ischemic brain injury

One of the most important causes of brain injury in the neonatal period is a perinatal hypoxicischemic event.This devastating condition can lead to long-term neurological deficits or even death.After hypoxic-ischemic brain injury,a variety of specific cellular mechanisms are set in motion,triggering cell damage and finally producing cell death.Effective therapeutic treatments against this phenomenon are still unavailable because of complex molecular mechanisms underlying hypoxic-ischemic brain injury.After a thorough understanding of the mechanism underlying neural plasticity following hypoxic-ischemic brain injury,various neuroprotective therapies have been developed for alleviating brain injury and improving long-term outcomes.Among them,the endocannabinoid system emerges as a natural system of neuroprotection.The endocannabinoid system modulates a wide range of physiological processes in mammals and has demonstrated neuroprotective effects in different paradigms of acute brain injury,acting as a natural neuroprotectant.The aim of this review is to study the use of different therapies to induce long-term therapeutic effects after hypoxic-ischemic brain injury,and analyze the important role of the endocannabinoid system as a new neuroprotective strategy against perinatal hypoxic-ischemic brain injury.