Influence of temperature, stress, and grain size on behavior of nano-polycrystalline niobium

Atomic simulations are executed to investigate the creep responses of nano-polycrystalline(NC) niobium established by using the Voronoi algorithm. The effects of varying temperature, applied stress, and grain size(GS) on creep properties and mechanisms are investigated. Notably, the occurrence of tertiary creep is exclusively observed under conditions where the applied stress exceeds 4.5 GPa and the temperature is higher than 1100 K. This phenomenon can be attributed to the significant acceleration of grain boundary and lattice diffusion, driven by the elevated temperature and stress levels. It is found that the strain rate increases with both temperature and stress increasing. However, an interesting trend is observed in which the strain rate decreases as the grain size increases. The stress and temperature are crucial parameters governing the creep behavior. As these factors intensify, the creep mechanism undergoes a sequential transformation: initially from lattice diffusion under low stress and temperature conditions to a mixed mode combining grain boundaries(GBs) and lattice diffusion at moderate stress and mid temperature levels, and ultimately leading to the failure of power-law controlled creep behavior, inclusive of grain boundary recrystallization under high stress and temperature conditions. This comprehensive analysis provides in more detail an understanding of the intricate creep behavior of nano-polycrystalline niobium and its dependence on various physical parameters.

Role of feline ANP32 proteins in regulating polymerase activity of influenza A virus

Recently,increasing natural infection cases and experimental animal challenge studies demonstrated domestic cats are susceptible to multiple subtypes influenza A virus(IAV)infections.Notably,some subtype IAV strains could circulate in domestic cats after cross-species transmission and even infected humans,posing a threat to public health.Host factors related to viral polymerase activity could determine host range of IAV and acidic nuclear phosphoprotein 32(ANP32)is the most important one among them.However,role of cat-derived ANP32 on viral polymerase activity and host range of IAV is still unknown.In the present study,a total of 10 feline ANP32(feANP32)splice variants(including 5 feANP32A,3 feANP32B,and 2 feANP32E)were obtained from domestic cats by RT-PCR.Sequence alignment results demonstrated amino acid deletions and/or insertions occurred among feANP32 variants,but all feANP32 proteins were primarily localized to cell nucleus.Minigenome replication systems for several representative IAV strains were established and the support ability of feANP32 on IAV polymerase activity was estimated.The results indicated that most feANP32A and feANP32B splice variants were able to support all the tested IAV strains,though the support activity of a single feANP32 protein on polymerase activity varied among different IAV strains.In addition,the role of feANP32 in supporting H3N2 canine influenza virus was determined by investigating viral replication in vitro.Collectively,our study systematically investigated the support activity of feANP32 on IAV,providing a clue for further exploring the mechanism of susceptibility of cats to IAV.

Extracellular vesicles from iPSC-MSCs alleviate chemotherapy-induced mouse ovarian damage via the ILK-PI3K/AKT pathway

Chemotherapy can significantly reduce follicle counts in ovarian tissues and damage ovarian stroma,causing endocrine disorder,reproductive dysfunction,and primary ovarian insufficiency(POI).Recent studies have suggested that extracellular vesicles(EVs)secreted from mesenchymal stem cells(MSCs)exert therapeutic effects in various degenerative diseases.In this study,transplantation of EVs from human induced pluripotent stem cell-derived MSCs(iPSC-MSC-EVs)resulted in significant restoration of ovarian follicle numbers,improved granulosa cell proliferation,and inhibition of apoptosis in chemotherapy-damaged granulosa cells,cultured ovaries,and in vivo ovaries in mice.Mechanistically,treatment with i PSC-MSC-EVs resulted in up-regulation of the integrinlinked kinase(ILK)-PI3K/AKT pathway,which is suppressed during chemotherapy,most likely through the transfer of regulatory microRNAs(miRNAs)targeting ILK pathway genes.This work provides a framework for the development of advanced therapeutics to ameliorate ovarian damage and POI in female chemotherapy patients.

Accelerated Sequential Deposition Reaction via Crystal Orientation Engineering for Low-Temperature,High-Efficiency Carbon-Electrode CsPbBr_(3) Solar Cells

Low-temperature,ambient processing of high-quality CsPbBr_(3)films is demanded for scalable production of efficient,low-cost carbon-electrode perovskite solar cells(PSCs).Herein,we demonstrate a crystal orientation engineering strategy of PbBr_(2)precursor film to accelerate its reaction with CsBr precursor during two-step sequential deposition of CsPbBr_(3)films.Such a novel strategy is proceeded by adding CsBr species into PbBr_(2)precursor,which can tailor the preferred crystal orientation of PbBr_(2)film from[020]into[031],with CsBr additive staying in the film as CsPb_(2)Br_(5)phase.Theoretical calculations show that the reaction energy barrier of(031)planes of PbBr_(2)with CsBr is lower about 2.28 eV than that of(O2O)planes.Therefore,CsPbBr_(3)films with full coverage,high purity,high crystallinity,micro-sized grains can be obtained at a low temperature of 150℃.Carbon-electrode PSCs with these desired CsPbBr_(3)films yield the record-high efficiency of 10.27%coupled with excellent operation stability.Meanwhile,the 1 cm^(2)area one with the superior efficiency of 8.00%as well as the flexible one with the champion efficiency of 8.27%and excellent mechanical bending characteristics are also achieved.

Effect of synergistic action of ultrasonic vibration and solidification pressure on tensile properties of vacuum counter-pressure casting aluminum alloy

The effect of synergistic action of ultrasonic vibration and solidification pressure on tensile properties of vacuum counter-pressure casting ZL114 A alloys was studied systemically through testing and analyzing the tensile strength and elongation subjected to different ultrasonic powers and solidification pressures. The results indicate that the synergistic action of ultrasonic vibration and solidification pressure can result in the refinement of grains and improvement of tensile properties. Both the highest tensile strength and elongation of aluminum alloy were obtained under synergistic action of 600 W ultrasonic power and 350 kPa solidification pressure. Moreover, the tensile fracture morphology shows obvious ductile fracture characteristics. When the solidification pressure is lower than 300 kPa, the effect of ultrasonic power on tensile strength and elongation is more obvious, but when the solidification pressure is higher than 300 kPa, the effect of solidification pressure on tensile strength and elongation is greater. Meanwhile, the size and morphology of the eutectic silicon were improved significantly by the ultrasonic vibration and pressurized solidification. The strip and massive eutectic silicon phase are completely converted into small short rod-like and evenly distributed Si phases at the grain boundary of primary α-Al.

Transactivation of the TIEG1 confers growth inhibition of transforming growth factor-β-susceptible hepatocellular carcinoma cells

AIM:To investigate the role of transforming growth factor(TGF)-β-inducible early gene 1(TIEG1) in TGF-β-induced growth inhibition in hepatocellular carcinoma(HCC) cells.METHODS:Human hepatocyte and HCC cell lines with varied susceptibilities to TGF-β1 were tested by methylthiazoletetrazolium(MTT) assay.The expression changes of Smad2,Smad3,Smad4,Smad7,TIEG1 and TIEG2 gene following treatment with TGF-β1 in a TGF-β-sensitive hepatocyte cell line(MIHA),a TGF-β-sensitive hepatoma cell line(Hep3B) and two TGF-β-insensitive hepatoma cell lines(HepG2 and Bel7404) were examined.SiRNA targeting TIEG1 was transfected into Hep3B cells and the sensitivity of cells to TGF-β1 was examined.Overexpression of TIEG1 was induced by lentiviral-mediated transduction in TGF-β1-resistant hepatoma cell lines(Bel7404 and HepG2).MTT assay and 4',6-Diamidino-2-phenylindole staining were used to identify cell viability and apoptosis,respectively.The expression level of stathmin was measured by reverse transcriptase polymerase chain reaction and Western-blotting analysis,and stathmin promoter activity by TIEG1 was monitored by a luciferase reporter gene system.RESULTS:TIEG1 was significantly upregulated by TGF-β1 in the TGF-β1-sensitive HCC cell line,Hep3B,but not in the resistant cell lines.The suppression of TIEG1 by siRNAs decreased the sensitivity of Hep3B cells to TGF-β1,whereas the overexpression of TIEG1 mediated growth inhibition and apoptosis in TGF-β1-resistant HCC cell lines,which resembled those of TGF-β1-sensitive HCC cells treated with TGF-β1.Our data further suggested that stathmin was a direct target of TIEG1,as stathmin was signif icantly downregulated by TIEG1 overexpression,and stathmin promoter activity was inhibited by TIEG1 in a dose-dependent manner.CONCLUSION:Our data suggest that transactivation of TIEG1 conferred growth inhibition of TGF-β-susceptible human HCC cells.

Synthesis of Flurbiprofen via Suzuki Reaction Catalyzed by Palladium Charcoal in Water

Flurbiprofen 1, an excellent nonsteroidal antiinflammatory drug, was synthesized in 5 steps in 69% overall yield. The key step of constructing the biaryl fragment was successfully achieved via Pd/C-catalyzed Suzuki coupling reaction in water using sodium tetraphenylborate as phenylation reagent.

Density and solidification feeding model of vacuum counter-pressure cast aluminum alloy under grade-pressuring conditions

The density of vacuum counter-pressure cast aluminum alloy samples under grade-pressuring condition was studied. The effect of grade pressure difference and time on the density of aluminum alloys was discussed, and the solidification feeding model under grade-pressuring condition was established. The results indicate the grade-pressured solidification feeding ability of vacuum counter-pressure casting mainly depends on grade pressure difference and time. With the increase of grade pressure difference, the density of all the aluminum alloy samples increases, and the trend of change in density from the pouring gate to the top location is first decreasing gradually and then increasing. In addition, in obtaining the maximum density, the optimal grade-pressuring time is different for samples with different wall thicknesses, and the solidification time when the solid volume fraction of aluminum alloy reaches about 0.65 appears to be the optimal beginning time for gradepressuring.

Multimodal MRI diagnosis and transvenous embolization of a basicranial emissary vein dural arteriovenous fistula:A case report

A dural arteriovenous fistula(DAVF) is an abnormal linkage connecting the arterial and venous systems within the intracranial dura mater. A basicranial emissary vein DAVF drains into the cavernous sinus and the ophthalmic vein, similar to a cavernous sinus DAVF. Precise preoperative identification of the DAVF location is a prerequisite for appropriate treatment. Treatment options include microsurgical disconnection, endovascular transarterial embolization(TAE), transvenous embolization(TVE), or a combination thereof. TVE is an increasingly popular approach for the treatment of DAVFs and the preferred approach for skull base locations, due to the risk of cranial neuropathy caused by dangerous anastomosis from arterial approaches. Multimodal magnetic resonance imaging(MRI) can provide anatomical and hemodynamic information for TVE. The therapeutic target must be precisely embolized in the emissary vein, which requires guidance via multimodal MRI. Here, we report a rare case of successful TVE for a basicranial emissary vein DAVF, utilizing multimodal MRI assistance. The fistula had vanished, pterygoid plexus drainage had improved, and the inferior petrosal sinus had recanalized, as observed on 8-month follow-up angiography. Symptoms and signs of double vision, caused by abduction deficiency, disappeared. Detailed anatomic and hemodynamic assessment by multimodal MRI is the key to guiding successful diagnosis and treatment.

紫外老化对聚醚-MDI型聚氨酯弹性体性能的影响

采用紫外老化加速方法模拟高分子材料自然老化现象,探究聚氨酯材料老化前后性能差异,为聚氨酯制品工业化生产参数的选定提供参考。选择聚醚-二苯基甲烷二异氰酸酯(MDI)预聚物为研究对象,一步法合成了聚醚-MDI型聚氨酯弹性体试样,对试样的力学等性能进行了测试,同时对紫外加速老化120 h,240 h后的试样也做了同种性能测试。结果发现,紫外老化前后试样的拉伸强度由21.8 MPa提高至30.8 MPa,撕裂强度由93 kN/m上升到109 kN/m,氧指数由23.4%下降至21.4%,其他方面性能均无明显变化,分析可能是受到端基官能团和物料内部残留的少量扩链剂等因素影响,聚氨酯内部结构及柔顺性出现了微妙改变,导致其相关性能出现了不同程度的变化。

聚乙二醇-氧化亚铜微胶囊防污涂料的制备及性能

采用葡萄糖还原-单凝聚法合成了聚乙二醇-氧化亚铜(PEG-Cu2O)微胶囊,并用透射电镜和红外光谱对微胶囊的结构组成和包覆效果进行了验证。以合成的微胶囊为防污剂,聚氨酯/环氧树脂(PU/EP)共混树脂为基体制备防污涂料试样,并对涂料试样的涂层硬度、抗冲击性、拉伸强度、剪切强度、吸水性能及释放性能等进行了测试。探究了防污剂的种类和用量对防污涂料性能的影响,结果发现与使用普通Cu2O作为防污剂的涂料试样相比,使用PEG-Cu2O微胶囊的涂料试样涂层硬度、抗冲击性、拉伸强度、剪切强度、吸水率和缓释效果等性能均有了较大幅度的提升和改善;但当PEG-Cu2O用量增加至40 phr时,微胶囊对防污涂料性能的改善效果有一定程度的减弱;综合考虑涂料试样的各种性能,确定PEG-Cu2O用量以20 phr为宜。对遴选的优异配方涂料进行浅海挂板防污试验,结果发现,用量为20 phr的微胶囊涂料达到了与商品防污涂料基本相当的防污效果。

不同表面润湿性水润滑材料的摩擦特性

舰船螺旋桨轴与轴承之间不良的润滑状态会导致严重磨损和异常噪声,对其可靠性和隐身性带来隐患。文中选取表面润湿性不同的聚四氟乙烯(PTFE)和聚甲醛(POM)在6种工况水环境下进行环-块摩擦试验,分析其摩擦学特性。使用带有高精度振动加速度传感器的摩擦试验装置采集其振动信号,通过小波包分解和重解对信号特征进行增强,拉曼光谱表征试验前后材料摩擦面的分子结构。结果表明,高载荷下PTFE比磨损率随转速增大呈现线性变化,POM则出现显著的指数变化;材料在摩擦前后的表面均未发生化学变化,铜环没有擦伤和转移到材料表面;POM在低转速下的摩擦振动更大,高转速下则相反;转速达到1000 r/min时,POM产生了稳定的水膜,显示了良好的水润滑效果。

Complete genome sequence of the rifamycin SV-producing Amycolatopsis mediterranei U32 revealed its genetic characteristics in phylogeny and metabolism

Amycolatopsis mediterranei is used for industry-scale production of rifamycin, which plays a vital role in antimyco- bacterial therapy. As the first sequenced genome of the genus Amycolatopsis, the chromosome of strain U32 comprising 10 236 715 base pairs, is one of the largest prokaryotic genomes ever sequenced so far. Unlike the linear topology found in streptomycetes, this chromosome is circular, particularly similar to that of Saccharopolyspora erythraea and Nocardia farcinica, representing their close relationship in phylogeny and taxonomy. Although the predicted 9 228 protein-coding genes in the A. mediterranei genome shared the greatest number of orthologs with those of S. erythraea, it was unexpectedly followed by Streptomyces coelicolor rather than N. farcinica, indicating the distinct metabolic characteristics evolved via adaptation to diverse ecological niches. Besides a core region analogous to that common in streptomycetes, a novel ＇quasicore＇ with typical core characteristics is defined within the non-core region, where 21 out of the total 26 gene clusters for secondary metabolite production are located. The rifamycin biosynthesis gene cluster located in the core encodes a cytochrome P450 enzyme essential for the conversion of rifamycin SV to B, revealed by comparing to the highly homologous cluster of the rifamycin B-producing strain S699 and further confirmed by genetic complementation. The genomic information of A. mediterranei demonstrates a metabolic network orchestrated not only for extensive utilization of various carbon sources and inorganic nitrogen compounds but also for effective funneling of metabolic intermediates into the secondary antibiotic synthesis process under the control of a seemingly complex regulatory mechanism.

Glial cell-derived neurotrophic factor mRNA expression in a rat model of spinal cord injury following bone marrow stromal cell transplantation

BACKGROUND： Several animal experiments utilizing bone marrow stromal cell （BMSC） transplantation for the treatment of spinal cord injury have proposed a hypothesis that BMSC transplantation effects are associated with increased glial cell-derived neurotrophic factor （GDNF） expression. OBJECTIVE： To confirm the effects of BMSC transplantation on GDNF mRNA expression in rats with spinal cord injury by reverse transcription-polymerase chain reaction （RT-PCR）. DESIGN, TIME AND SETTING： The present molecular, cell biology experiment was performed at the Key Laboratory of Children＇s Congenital Malformation, Ministry of Health of China ＆ Department of Developmental Biology, Basic Medical College, China Medical University between March 2006 and May 2007. MATERIALS： Sixty healthy Wistar rats aged 2-4-months and of either gender were included in this study. Spinal cord injury was induced in all rats by hemisection of T9 on the left side. RT-PCR kits were purchased from TaKaRa Company, China. Type 9600 RCR amplifier was provided by Perkin Elmer Company, USA. METHODS： Three rats were selected for BMSC culture and subsequent transplantation （after three passages）. Of the remaining 57 rats, nine were selected for sham-operation （sham-operated group）, where only the T9 spinal cord was exposed without hemisection. A total of 48 rats were randomly and evenly divided into BMSC transplantation and model groups. In the BMSC transplantation group, following spinal cord injury induction, each rat was administered a BMSC suspension tbrougb two injection sites selected on the gray and white matter boundary caudally and cephalically, seperately and near to injury site in the spinal cord. The model group received an equal volume of PBS through the identical injection sites. MAIN OUTCOME MEASURES： At 24 and 72 hours, as well as at 7 days, following spinal cord injury, the spinal cord at the T9 segment was removed. Eight rats were allocated to each time point in the BMSC transplantation and model groups, with three rats allocated to the sham-operated group. GDNF mRNA expression was semiquantitatively analyzed by RT-PCR. RESULTS： The sham-operated group exhibited extremely low GDNF mRNA expression. GDNF mRNA expression significantly increased at 24 hours after spinal cord injury, reached a peak level at 72 hours, and slowly decreased thereafter. However, it remained higher than normal levels at 7 days （P 〈 0.05）. At all time points following spinal cord injury, GDNF mRNA expression was significantly greater in the BMSC transplantation group than in the model group （P 〈 0.05）. CONCLUSION： Transplantation of BMSCs into the injured spinal cord up-regulated GDNF mRNA expression, thereby promoting repair of the injured spinal cord.

Identification of coastal wetlands of international importance for waterbirds:a review of China Coastal Waterbird Surveys 2005–2013

Background:China's coastal wetlands belong to some of the most threatened ecosystems worldwide.The loss and degradation of these wetlands seriously threaten waterbirds that depend on wetlands.Methods:The China Coastal Waterbird Census was organized by volunteer birdwatchers in China's coastal region.Waterbirds were surveyed synchronously once every month at 14 sites,as well as irregularly at a further 18 sites,between September 2005 and December 2013.Results:A total of 75 species of waterbirds met the 1 % population level Ramsar listing criterion at least once at one site.The number of birds of the following species accounted for over 20 % of the total flyway populations at a single site:Mute Swan(Cygnus olor),Siberia Crane(Grus leucogeranus),Far Eastern Oystercatcher(Haematopus osculans),Bar-tailed Godwit(Limosa lapponica),Spotted Greenshank(Tringa guttifer),Great Knot(Calidris tenuirostris),Spoon-billed Sandpiper(Calidris pygmeus),Saunders' s Gull(Larus saundersi),Relict Gull(Larus relictus),Great Cormorant(Phalacrocorax carbo),Eurasian Spoonbill(Platalea leucorodia),Black-faced Spoonbill(Platalea minor) and Dalmatian Pelican(Pelecanus crispus).A total of 26 sites supported at least one species of which their number met the1 % criterion.Forty-two species met the 1 % criterion in the Yellow River Delta,Shandong;29 at the Cangzhou coast,Hebei and 26 species at the Lianyungang coast,Jiangsu.Conclusions:The results highlight the international importance of China's coastal wetlands for waterbirds.This study also demonstrates that participation of local birdwatchers in waterbird surveys results in data that are invaluable not only for understanding the current status of waterbirds in China's coastal regions but also for waterbird conservation and management.

Bioinformatic analysis for structure and function of TCTP from Spirometra mansoni

Objective:To predict structure and function of translationally controlled tumor protein(TCTP)from Spirometraa mansoni by bioinformatics technology,and to provide a theoretical basis for further study.Methods:Open reading frame(ORF)of EST sequence from Spirometra mansoni was obtained by ORE finder and was translated into amino acid residue by DNAclub.The structure domain was analyzed by Blast.By the method of online analysis tools:Protparam,InterProScan,protscale.SignalP-3.0,PSORTⅡ,BepiPred,TMHMM,VectorNT1 Suite 9 packages and Phyre2,the structure and function of the protein were predicted and analyzed.Results:The results showed that the EST sequence was Sm TCTP with 173 amino acid residues,theoretical molecular weight was 19 872.0 Da.The protein has the closest evolutionary status with Clonorchis sinensis.Schistosoma mansoni,and Schistosoma japonicum.Then it had no signal peptide site and transmembrane domain.Secondary structure of TCTP contained twoα-helices and eightβ-strands.Conclusions:Sm TCTP was a variety of biological functions of protein that may be used as a vaccine candidate molecule anti drug target.

Microglia activation,classification and microglia-mediated neuroinflammatory modulators in subarachnoid hemorrhage

Subarachnoid hemorrhage is a devastating disease with significant mortality and morbidity,despite advances in treating cerebral aneurysms.There has been recent progress in the intensive care management and monitoring of patients with subarachnoid hemorrhage,but the results remain unsatisfactory.Microglia,the resident immune cells of the brain,are increasingly recognized as playing a significant role in neurological diseases,including subarachnoid hemorrhage.In early brain injury following subarachnoid hemorrhage,microglial activation and neuroinflammation have been implicated in the development of disease complications and recovery.To understand the disease processes following subarachnoid hemorrhage,it is important to focus on the modulators of microglial activation and the pro-inflammatory/anti-inflammatory cytokines and chemokines.In this review,we summarize research on the modulators of microglia-mediated inflammation in subarachnoid hemorrhage,including transcriptome changes and the neuroinflammatory signaling pathways.We also describe the latest developments in single-cell transcriptomics for microglia and summarize advances that have been made in the transcriptome-based classification of microglia and the implications for microglial activation and neuroinflammation.

Numerical modeling of metamorphic core complex formation:Implications for the destruction of the North China Craton

Widespread magmatism, metamorphic core complexes(MCCs), and significant lithospheric thinning occurred during the Mesozoic in the North China Craton(NCC). It has been suggested that the coeval exhumation of MCCs with uniform northwest-southeast shear senses and magmatism probably resulted from a decratonization event during the retreat of the paleo-Pacific Plate. Here we used two-dimensional finite element thermomechanical numerical models to investigate critical parameters controlling the formation of MCCs under far-field extensional stress. We observed three end-member deformation modes: the MCC mode, the symmetric-dome mode, and the pure-shear mode. The MCC mode requires a Moho temperature of ≥700 ℃ and an extensional strain rate of ≥5 × 10^(-16)s^(-1), implying that the lithosphere had already thinned when the MCC was formed in the Mesozoic. Considering that the widespread MCCs have the same northwest-southeast extension direction in the NCC, we suggest that the MCCs are surface expressions of both large-scale extension and craton destruction and that rollback of the paleo-Pacific slab might be the common driving force.

Identification and bioinformatics analysis of lactate dehydrogenase genes from Echinococcus granulosus

Objective:To identify full length cDNA sequence of lactate dehydrogenase(LDH) from adult Echinococcus granulosus(E.granulosus) and to predict the structure and function of its encoding protein using bioinformatics methods.Methods:With the help of NCBI,EMBI, Expasy and other online sites,the open reading frame(ORF),conserved domain,physical and chemical parameters,signal peptide,epitope,topological structures of the protein sequences were predicted and a homology tertiary structure model was created:Vector NT1 software was used for sequence alignment,phylogenetic tree construction and tertiary structure prediction. Results:The target sequence was 1 233 bp length with a 996 bp biggest ORF encoding 331 amino acids protein with typical L-LDH conserved domain.It was confirmed as full length cDNA of LDH from E.granulosus and named as EgLDH(GenBank accession number:HM748917).The predicted molecular weight and isoelectric point of the deduced protein were 3 5516.2Da and 6.32 respectively.Compared with LDHs from Taenia solium,Taenia saginata asiatica,Spirometra erinaceieuropaei.Schistosoma japonicum,Clonorchis sinensis and human,it showed similarity of 86% ,85% ,55% ,58% ,58% and 53% ,respectively.EgLDH contained 3 putative transmembrane regions and 4 major epitopes(54aa-59aa.81aa-87aa,97aa-102aa,307aa-313aa),the latter were significant different from the corresponding regions of human LDH.In addition,some NAD and substrate binding sites located on epitopes 54aa-59aa and 97aa-102aa,respectively.Tertiary structure prediction showed that 3 key catalytic residues 105R,165D and 192H forming a catalytic center near the epitope 97aa-102aa,most NAD and substrate binding sites located around the center.Conclusions:The full length cDNA sequences of EgLDH were identified.It encoded a putative transmembrane protein which might be an ideal target molecule for vaccine and drugs.

Expression changes of hippocampal energy metabolism enzymes contribute to behavioural abnormalities during chronic morphine treatment

Dependence and impairment of learning and memory are two well-established features caused by abused drugs such as opioids. The hippocampus is an important region associated with both drug dependence and learning and memory. However, the molecular events in hippocampus following exposure to abused drugs such as opioids are not well understood. Here we examined the effect of chronic morphine treatment on hippocampal protein expression by proteomic analyses. We found that chronic exposure of mice to morphine for 10 days produced robust morphine withdrawal jumping and memory impairment, and also resulted in a significant downregulation of hippocampal protein levels of three metabolic enzymes, including Fe-S protein 1 ofNADH dehydrogenase, dihydrolipoamide acetyltransferase or E2 component of the pyruvate dehydrogenase complex and lactate dehydrogenase 2. Further real-time quantitative PCR analyses confirmed that the levels of the corresponding mRNAs were also remarkably reduced. Consistent with these findings, lower ATP levels and an impaired ability to convert glucose into ATP were also observed in the hippocampus of chronically treated mice. Opioid antagonist naltrexone administrated concomitantly with morphine significantly suppressed morphine withdrawal jumping and reversed the downregulation of these proteins. Acute exposure to morphine also produced robust morphine withdrawal jumping and significant memory impairment, but failed to decrease the expression of these three proteins. Intrahippocampal injection of D-glucose before morphine administration significantly enhanced ATP levels and suppressed morphine withdrawal jumping and memory impairment in acute morphine-treated but not in chronic morphine-treated mice. Intraperitoneal injection of high dose of D-glucose shows a similar effect on morphine-induced withdrawal jumping as the central treatment. Taken together, our results suggest that reduced expression of the three metabolic enzymes in the hippocampus as a result of chronic morphine treatment contributes to the development of drug-induced symptoms such as morphine withdrawal jumping and memory impairment.