期刊文献+
共找到116篇文章
< 1 2 6 >
每页显示 20 50 100
Loss of LBP triggers lipid metabolic disorder through H3K27 acetylation-mediated C/EBPβ-SCD activation in non-alcoholic fatty liver disease 被引量:1
1
作者 Ya-Ling Zhu Lei-Lei Meng +17 位作者 Jin-Hu Ma Xin Yuan Shu-Wen Chen Xin-Rui Yi Xin-Yu Li Yi Wang Yun-Shu Tang Min Xue Mei-Zi Zhu Jin Peng Xue-Jin Lu Jian-Zhen Huang Zi-Chen Song Chong Wu Ke-Zhong Zheng Qing-Qing Dai Fan Huang Hao-Shu Fang 《Zoological Research》 SCIE CSCD 2024年第1期79-94,共16页
Non-alcoholic fatty liver disease(NAFLD)is associated with mutations in lipopolysaccharide-binding protein(LBP),but the underlying epigenetic mechanisms remain understudied.Herein,LBP^(-/-)rats with NAFLD were establi... Non-alcoholic fatty liver disease(NAFLD)is associated with mutations in lipopolysaccharide-binding protein(LBP),but the underlying epigenetic mechanisms remain understudied.Herein,LBP^(-/-)rats with NAFLD were established and used to conduct integrative targetingactive enhancer histone H3 lysine 27 acetylation(H3K27ac)chromatin immunoprecipitation coupled with high-throughput and transcriptomic sequencing analysis to explore the potential epigenetic pathomechanisms of active enhancers of NAFLD exacerbation upon LBP deficiency.Notably,LBP^(-/-)reduced the inflammatory response but markedly aggravated high-fat diet(HFD)-induced NAFLD in rats,with pronounced alterations in the histone acetylome and regulatory transcriptome.In total,1128 differential enhancer-target genes significantly enriched in cholesterol and fatty acid metabolism were identified between wild-type(WT)and LBP^(-/-)NAFLD rats.Based on integrative analysis,CCAAT/enhancer-binding proteinβ(C/EBPβ)was identified as a pivotal transcription factor(TF)and contributor to dysregulated histone acetylome H3K27ac,and the lipid metabolism gene SCD was identified as a downstream effector exacerbating NAFLD.This study not only broadens our understanding of the essential role of LBP in the pathogenesis of NAFLD from an epigenetics perspective but also identifies key TF C/EBPβand functional gene SCD as potential regulators and therapeutic targets. 展开更多
关键词 Non-alcoholic fatty liver disease C/EBPΒ Lipopolysaccharide-binding protein H3K27ac Integrative analysis ENHANCER
下载PDF
Elimination of methicillin‑resistant Staphylococcus aureus biofilms on titanium implants via photothermally‑triggered nitric oxide and immunotherapy for enhanced osseointegration
2
作者 Yong‑Lin Yu Jun‑Jie Wu +5 位作者 Chuan‑Chuan Lin Xian Qin Franklin R.Tay Li Miao Bai‑Long Tao Yang Jiao 《Military Medical Research》 SCIE CAS CSCD 2024年第2期157-179,共23页
Background:Treatment of methicillin-resistant Staphylococcus aureus(MRSA)biofilm infections in implant placement surgery is limited by the lack of antimicrobial activity of titanium(Ti)implants.There is a need to expl... Background:Treatment of methicillin-resistant Staphylococcus aureus(MRSA)biofilm infections in implant placement surgery is limited by the lack of antimicrobial activity of titanium(Ti)implants.There is a need to explore more effective approaches for the treatment of MRSA biofilm infections.Methods:Herein,an interfacial functionalization strategy is proposed by the integration of mesoporous polydopamine nanoparticles(PDA),nitric oxide(NO)release donor sodium nitroprusside(SNP)and osteogenic growth peptide(OGP)onto Ti implants,denoted as Ti-PDA@SNP-OGP.The physical and chemical properties of Ti-PDA@SNP-OGP were assessed by scanning electron microscopy,X-ray photoelectron spectroscope,water contact angle,photothermal property and NO release behavior.The synergistic antibacterial effect and elimination of the MRSA biofilms were evaluated by 2′,7′-dichlorofluorescein diacetate probe,1-N-phenylnaphthylamine assay,adenosine triphosphate intensity,O-nitrophenyl-β-D-galactopyranoside hydrolysis activity,bicinchoninic acid leakage.Fluorescence staining,assays for alkaline phosphatase activity,collagen secretion and extracellular matrix mineralization,quantitative real‑time reverse transcription‑polymerase chain reaction,and enzyme-linked immunosorbent assay(ELISA)were used to evaluate the inflammatory response and osteogenic ability in bone marrow stromal cells(MSCs),RAW264.7 cells and their co-culture system.Giemsa staining,ELISA,micro-CT,hematoxylin and eosin,Masson's trichrome and immunohistochemistry staining were used to evaluate the eradication of MRSA biofilms,inhibition of inflammatory response,and promotion of osseointegration of Ti-PDA@SNP-OGP in vivo.Results:Ti-PDA@SNP-OGP displayed a synergistic photothermal and NO-dependent antibacterial effect against MRSA following near-infrared light(NIR)irradiation,and effectively eliminated the formed MRSA biofilms by inducing reactive oxygen species(ROS)-mediated oxidative stress,destroying bacterial membrane integrity and causing leakage of intracellular components(P<0.01).In vitro experiments revealed that Ti-PDA@SNP-OGP not only facilitated osteogenic differentiation of MSCs,but also promoted the polarization of pro-inflammatory M1 macrophages to the anti-inflammatory M2-phenotype(P<0.05 or P<0.01).The favorable osteo-immune microenvironment further facilitated osteogenesis of MSCs and the anti-inflammation of RAW264.7 cells via multiple paracrine signaling pathways(P<0.01).In vivo evaluation confirmed the aforementioned results and revealed that Ti-PDA@SNP-OGP induced ameliorative osseointegration in an MRSA-infected femoral defect implantation model(P<0.01).Conclusions:Ti-PDA@SNP-OGP is a promising multi-functional material for the high-efficient treatment of MRSA infections in implant replacement surgeries. 展开更多
关键词 Polydopamine nanoparticles Methicillin-resistant Staphylococcus aureus Nitric oxide OSSEOINTEGRATION Osteo-immunomodulation Photothermal effect Titanium implants
下载PDF
Experimental Study of the Effect ofWater Salinity on the Parameters of an Equilibrium Droplet Cluster Levitating over aWater Layer
3
作者 Alexander A.Fedorets Eduard E.Kolmakov Leonid A.Dombrovsky 《Frontiers in Heat and Mass Transfer》 EI 2024年第1期1-14,共14页
New experimental results,which are important for the potential use of small levitating droplets as biochemical microreactors,are reported.It is shown that the combination of infrared heating and reduced evaporation of... New experimental results,which are important for the potential use of small levitating droplets as biochemical microreactors,are reported.It is shown that the combination of infrared heating and reduced evaporation of saline water under the droplet cluster is sufficient to produce equilibriumsaltwater droplets over a wide temperature range.The resulting universal dependence of droplet size on temperature simplifies the choice of optimal conditions for generating stable droplet clusters with droplets of the desired size.A physical analysis of the experimental results on the equilibrium size of saltwater droplets makes it possible to separate the effects related to the salinity of the water layer under the droplet cluster from the effects related to the reduction of water evaporation from the water droplets.This is expected to be important for further studies of heat transfer and diffusion in layers of evaporating solutions and condensed droplets. 展开更多
关键词 Droplet cluster saltwater LEVITATION STABILIZATION heat transfer evaporation and condensation
下载PDF
Electromagnetic pulses produced by a picosecond laser interacting with solid targets
4
作者 牛爱慧 康宁 +5 位作者 许国潇 谢佳节 滕建 刘会亚 孙明营 李廷帅 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第5期430-436,共7页
A high-power laser ablating solid targets induces giant electromagnetic pulses(EMPs),which are intimately pertinent to laser parameters,such as energy and pulse width.In this study,we reveal the features of EMPs gener... A high-power laser ablating solid targets induces giant electromagnetic pulses(EMPs),which are intimately pertinent to laser parameters,such as energy and pulse width.In this study,we reveal the features of EMPs generated from a picosecond(ps)laser irradiating solid targets at the SG-Ⅱpicosecond petawatt(PSPW)laser facility.The laser energy and pulse,as well as target material and thickness,show determinative effects on the EMPs’amplitude.More intense EMPs are detected behind targets compared to those at the other three positions,and the EMP amplitude decreases from 90.09 kV/m to 17.8 kV/m with the gold target thickness increasing from 10μm to 20μm,which is suppressed when the laser pulse width is enlarged.The results are expected to provide more insight into EMPs produced by ps lasers coupling with targets and lay the foundation for an effective EMP shielding design in high-power laser infrastructures. 展开更多
关键词 LASER electromagnetic pulse TARGET PROTON
下载PDF
Spatial and temporal evolution of electromagnetic pulses from solid target irradiated with multi-hundred-terawatt laser pulse inside target chamber
5
作者 何强友 邓志刚 +12 位作者 张智猛 夏亚东 张博 孟令彪 贺书凯 黄华 杨雷 刘红杰 范伟 林晨 周维民 李廷帅 颜学庆 《Plasma Science and Technology》 SCIE EI CAS CSCD 2024年第2期62-69,共8页
Giant electromagnetic pulses(EMPs) induced by high-power laser irradiating solid targets interfere with various experimental diagnoses and even damage equipment,so unveiling the evolution of EMPs inside the laser cham... Giant electromagnetic pulses(EMPs) induced by high-power laser irradiating solid targets interfere with various experimental diagnoses and even damage equipment,so unveiling the evolution of EMPs inside the laser chamber is crucial for designing effective EMP shielding.In this work,the transmission characteristics of EMPs as a function of distances from the target chamber center(TCC) are studied using B-dot probes.The mean EMP amplitude generated by picosecond laser-target interaction reaches 561 kV m^(-1),357 kV m^(-1),395 kV m^(-1),and 341 kV m^(-1)at 0.32 m,0.53 m,0.76 m,and 1 m from TCC,which decreases dramatically from 0.32 m to 0.53 m.However,it shows a fluctuation from 0.53 m to 1 m.The temporal features of EMPs indicate that time-domain EMP signals near the target chamber wall have a wider full width at half maximum compared to that close to TCC,mainly due to the echo oscillation of electromagnetic waves inside the target chamber based on simulation and experimentation.The conclusions of this study will provide a new approach to mitigate strong electromagnetic pulses by decreasing the echo oscillation of electromagnetic waves inside the target chamber during laser coupling with targets. 展开更多
关键词 TARGET electromagnetic pulses spatial distribution
下载PDF
Effi cacy of tricyclic antidepressants in irritable bowel syndrome:A meta-analysis 被引量:22
6
作者 Roja Rahimi Shekoufeh Nikfar +1 位作者 Ali Rezaie Mohammad Abdollahi 《World Journal of Gastroenterology》 SCIE CAS CSCD 2009年第13期1548-1553,共6页
We aimed to evaluate the efficacy of tricyclic antidepressants(TCAs) as a therapeutic option for irritable bowel syndrome(IBS) through meta-analysis of randomized controlled trials.For the years 1966 until September 2... We aimed to evaluate the efficacy of tricyclic antidepressants(TCAs) as a therapeutic option for irritable bowel syndrome(IBS) through meta-analysis of randomized controlled trials.For the years 1966 until September 2008,PubMed,Scopus,Web of Science,and Cochrane Central Register of Controlled Trials were searched for double-blind,placebo-controlled trials investigating the effi cacy of TCAs in the management of IBS.Seven randomized,placebo-controlled clinical trials met our criteria and were included in the metaanalysis.TCAs used in the treatment arm of these trials included amitriptyline,imipramine,desipramine,doxepin and trimipramine.The pooled relative risk for clinical improvement with TCA therapy was 1.93(95% CI:1.44 to 2.6,P<0.0001).Effect size of TCAs versus placebo for mean change in abdominal pain score among the two studies was -44.15(95% CI:-53.27 to -35.04,P<0.0001).It is concluded that low dose TCAs exhibit clinically and statistically signifi cant control of IBS symptoms. 展开更多
关键词 Systematic review META-ANALYSIS Tricyclic antidepressants Irritable bowel syndrome EFFICACY Clinical response Abdominal pain
下载PDF
Acacetin protects against cerebral ischemia-reperfusion injury via the NLRP3 signaling pathway 被引量:26
7
作者 Juan Bu Shen Shi +8 位作者 Hui-Qin Wang Xiao-Shan Niu Zong-Feng Zhao Wei-Dong Wu Xiao-Ling Zhang Zhi Ma Yan-Jun Zhang Hui Zhang Yi Zhu 《Neural Regeneration Research》 SCIE CAS CSCD 2019年第4期605-612,共8页
Acacetin(5,7-dihydroxy-4′-methoxyflavone), a potential neuroprotective agent, has an inhibitory effect on lipopolysaccharide-induced neuroinflammatory reactions. However, whether acacetin has an effect on inflammator... Acacetin(5,7-dihydroxy-4′-methoxyflavone), a potential neuroprotective agent, has an inhibitory effect on lipopolysaccharide-induced neuroinflammatory reactions. However, whether acacetin has an effect on inflammatory corpuscle 3(NLRP3) after cerebral ischemia-reperfusion injury has not been fully determined. This study used an improved suture method to establish a cerebral ischemia-reperfusion injury model in C57BL/6 mice. After ischemia with middle cerebral artery occlusion for 1 hour, reperfusion with intraperitoneal injection of 25 mg/kg of acacetin(acacetin group) or an equal volume of saline(0.1 mL/10 g, middle cerebral artery occlusion group) was used to investigate the effect of acacetin on cerebral ischemia-reperfusion injury. Infarct volume and neurological function scores were determined by 2,3,5-triphenyltetrazolium chloride staining and the Zea-Longa scoring method. Compared with the middle cerebral artery occlusion group, neurological function scores and cerebral infarction volumes were significantly reduced in the acacetin group. To understand the effect of acacetin on microglia-mediated inflammatory response after cerebral ischemia-reperfusion injury, immunohistochemistry for the microglia marker calcium adapter protein ionized calcium-binding adaptor molecule 1(Iba1) was examined in the hippocampus of ischemic brain tissue. In addition, tumor necrosis factor-α, interleukin-1β, and interleukin-6 expression in ischemic brain tissue of mice was quantified by enzyme-linked immunosorbent assay. Expression of Iba1, tumor necrosis factor-α, interleukin-1β and interleukin-6 was significantly lower in the acacetin group compared with the middle cerebral artery occlusion group. Western blot assay results showed that expression of Toll-like receptor 4, nuclear factor kappa B, NLRP3, procaspase-1, caspase-1, pro-interleukin-1β, and interleukin-1β were significantly lower in the acacetin group compared with the middle cerebral artery occlusion group. Our findings indicate that acacetin has a protective effect on cerebral ischemia-reperfusion injury, and its mechanism of action is associated with inhibition of microglia-mediated inflammation and the NLRP3 signaling pathway. 展开更多
关键词 nerve REGENERATION ACACETIN cerebral ISCHEMIA-REPERFUSION injury microglia NLRP3 inflammasome inflammatory FACTOR INFARCT volume signaling pathway nuclear factor-κB neuroprotection neural REGENERATION
下载PDF
A systematic review of effi cacy and tolerability of mebeverine in irritable bowel syndrome 被引量:17
8
作者 Mahnaz Darvish-Damavandi Shekoufeh Nikfar Mohammad Abdollahi 《World Journal of Gastroenterology》 SCIE CAS CSCD 2010年第5期547-553,共7页
We evaluated the eff icacy and tolerability of mebeverine, a musculotropic antispasmodic agent, in irritable bowel syndrome (IBS) and compared its usual dosages by meta-analysis. Medical databases and all relevant lit... We evaluated the eff icacy and tolerability of mebeverine, a musculotropic antispasmodic agent, in irritable bowel syndrome (IBS) and compared its usual dosages by meta-analysis. Medical databases and all relevant literature were searched from 1965 to June 2009 for any placebo-controlled clinical trials of mebeverine, using search terms such as mebeverine, clinical trials, and IBS. Eight randomized trials met our criteria, including six trials that compared mebeverine with placebo and two that compared mebeverine tablets with capsules. These eight trials included 555 patients randomized to receive either mebeverine or placebo with 352 (63%)women and 203 (37%) men in all subtypes of IBS. The pooled relative risk (RR) for clinical improvement of mebeverine was 1.13 (95% CI: 0.59-2.16, P = 0.7056) and 1.33 (95% CI: 0.92-1.93, P = 0.129) for relief of abdominal pain. The efficacy of mebeverine 200 mg compared to mebeverine 135 mg indicated RRs of 1.12 (95% CI: 0.96-1.3, P = 0.168) for clinical or global improvement and 1.08 (95% CI: 0.87-1.34, P = 0.463) for relief of abdominal pain. Thus, mebeverine is mostly well tolerated with no signif icant adverse effects; however, its eff icacy in global improvement of IBS is not statistically signif icant. 展开更多
关键词 Clinical trial Metaanalysis MEBEVERINE PLACEBO Irritable bowel syndrome Systematic review
下载PDF
Antioxidant therapy in the management of acute,chronic and post-ERCP pancreatitis:A systematic review 被引量:10
9
作者 Seyed Sajad Mohseni Salehi Monfared Hamed Vahidi +2 位作者 Amir Hossein Abdolghaffari Shekoufeh Nikfar Mohammad Abdollahi 《World Journal of Gastroenterology》 SCIE CAS CSCD 2009年第36期4481-4490,共10页
We systematically reviewed the clinical trials which recruited antioxidants in the therapy of pancreatitis and evaluated whether antioxidants improve the outcome of patients with pancreatitis. Electronic bibliographic... We systematically reviewed the clinical trials which recruited antioxidants in the therapy of pancreatitis and evaluated whether antioxidants improve the outcome of patients with pancreatitis. Electronic bibliographic databases were searched for any studies which investigated the use of antioxidants in the management of acute pancreatitis (AP) or chronic pancreatitis (CP) and in the prevention of post-endoscopic retrograde cholangio-pancreatography (post-ERCP) pancreatitis (PEP) up to February 2009. Twenty-two randomized, placebo-controlled, clinical trials met our criteria and were included in the review. Except for a cocktail of antioxidants which showed improvement in outcomes in three different clinical trials, the results of the administration of other antioxidants in both AP and CP clinical trials were incongruent and heterogeneous.Furthermore, antioxidant therapy including allopurinol and N-acetylcysteine failed to prevent the onset of PEP in almost all trials. In conclusion, the present data do not support a benefit of antioxidant therapy alone or in combination with conventional therapy in the management of AP, CP or PER Further double blind, randomized, placebo-controlled clinical trials with large sample size need to be conducted. 展开更多
关键词 ANTIOXIDANT Post-endoscopic retrogradecholangio-pancreatography pancreatitis Oxidative stress Therapy Acute pancreatitis Chronic pancreatitis
下载PDF
Effect of Electromagnetic Pulse Exposure on Permeability of Blood-testicle Barrier in Mice 被引量:5
10
作者 XIAO-WU WANG GUI-RONG DING +4 位作者 CHANG-HONG SHI TAO ZHAO JIE ZHANG LI-HUA ZENG Guo-ZHEN GUO 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2008年第3期218-221,共4页
Objective To study the effect of electromagnetic pulse (EMP) exposure on the permeability of blood-testicle barrier (BTB) in mice. Methods Adult male BALB/c mice were exposed to EMP at 200 kV/m for 200 pulses with... Objective To study the effect of electromagnetic pulse (EMP) exposure on the permeability of blood-testicle barrier (BTB) in mice. Methods Adult male BALB/c mice were exposed to EMP at 200 kV/m for 200 pulses with 2 seconds interval. The mice were injected with 2% Evans Blue solution through caudal vein at different time points after exposure, and the permeability of BTB was monitored using a fluorescence microscope. The testis sample for the transmission electron microscopy was prepared at 2 h after EMP exposure. The permeability of BTB in mice was observed by using Evans Blue tracer and lanthanum nitrate tracer. Results After exposure, cloudy Evans Blue was found in the testicle convoluted seminiferous tubule of mice. Lanthanum nitrate was observed not only between testicle spermatogonia near seminiferous tubule wall and sertoli cells, but also between sertoli cells and primary spermatocyte or secondary spermatocyte. In contrast, lanthanum nitrate in control group was only found in the testicle sertoli cells between seminiferous tubule and near seminifdrous tubule wall. Conclusion EMP exposure could increase the permeability of BTB in the mice. 展开更多
关键词 Electromagnetic pulse (EMP) Blood-testicle barrier (BTB) LANTHANUM Evans Blue PERMEABILITY MICE
下载PDF
A review of carbon dioxide disposal technology in the converter steelmaking process 被引量:10
11
作者 Rong Zhu Bao-chen Han +1 位作者 Kai Dong Guang-sheng Wei 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2020年第11期1421-1429,共9页
In last decade,the utilization of CO?resources in steelmaking has achieved certain metallurgical effects and the technology is maturing.In this review,we summarized the basic reaction theory of CO2,the CO2 conversion,... In last decade,the utilization of CO?resources in steelmaking has achieved certain metallurgical effects and the technology is maturing.In this review,we summarized the basic reaction theory of CO2,the CO2 conversion,and the change of energy-consumption when CO2 was introduced in converter steelmaking process.In the CO2-O2 mixed injection(COMI)process,the CO2 conversion ratio can be obtained as high as 80%or more with a control of the CO2 ratio in mixture gas and the flow rate of CO2,and the energy is saving and even the energy consumption can be reduced by 145.65 MJ/t under certain operations.In addition,a complete route of CO2 disposal technology is proposed combining the comparatively mature technologies of CO2 capture,CO2 compression,and liquid CO2 storage to improve the technology of CO2 utilization.The results are expected to form a large-scale,highly efficient,and valuable method to dispose of CO2. 展开更多
关键词 CO2 utilization carbon dioxide STEELMAKING enhanced stirring temperature control
下载PDF
Neuroprotective effects of tetrandrine against vascular dementia 被引量:14
12
作者 Yan-ling Lv Ze-zhi Wu +5 位作者 Li-xue Chen Bai-xue Wu Lian-lian Chen Guang-cheng Qin Bei Gui Ji-ying Zhou 《Neural Regeneration Research》 SCIE CAS CSCD 2016年第3期454-459,共6页
Tetrandrine is one of the major active ingredients in Menispermaceae Stephania tetrandra S.Moore,and has specific therapeutic effects in ischemic cerebrovascular disease.Its use in vascular dementia has not been studi... Tetrandrine is one of the major active ingredients in Menispermaceae Stephania tetrandra S.Moore,and has specific therapeutic effects in ischemic cerebrovascular disease.Its use in vascular dementia has not been studied fully.Here,we investigated whether tetrandrine would improve behavioral and cellular impairments in a two-vessel occlusion rat model of chronic vascular dementia.Eight weeks after model establishment,rats were injected intraperitoneally with 10 or 30 mg/kg tetrandrine every other day for 4 weeks.Behavioral assessment in the Morris water maze showed that model rats had longer escape latencies in training trials,and spent less time swimming in the target quadrant in probe trials,than sham-operated rats.However,rats that had received tetrandrine showed shorter escape latencies and longer target quadrant swimming time than untreated model rats.Hematoxylin-eosin and Nissl staining revealed less neuronal necrosis and pathological damage,and more living cells,in the hippocampus of rats treated with tetrandrine than in untreated model rats.Western blot assay showed that interleukin-1β expression,and phosphorylation of the N-methyl-D-aspartate 2B receptor at tyrosine 1472,were lower in model rats that received tetrandrine than in those that did not.The present findings suggest that tetrandrine may be neuroprotective in chronic vascular dementia by reducing interleukin-1β expression,N-methyl-D-aspartate receptor 2B phosphorylation at tyrosine 1472,and neuronal necrosis. 展开更多
关键词 nerve regeneration tetrandrine ischemic cerebrovascular disease vascular dementia N-methyl-D-aspartic acid receptor 2B N-methyl-D-aspartate receptor 2B phosphorylation at tyrosine 1472 interleukin-1β neuronal necrosis neural regeneration
下载PDF
Theoretical Analysis of A Buoyant Jet Interacting with Small Amplitude Waves 被引量:5
13
作者 Ying-Pin LIN Hung-Chu HSU Yang-Yih CHEN 《China Ocean Engineering》 SCIE EI 2009年第1期73-84,共12页
A new theoretical solution is presented here for the dynamic characteristics of a buoyant jet due to opposing small amplitude waves. The conservation equations of mass, tangential moment^n and vertical momentum are so... A new theoretical solution is presented here for the dynamic characteristics of a buoyant jet due to opposing small amplitude waves. The conservation equations of mass, tangential moment^n and vertical momentum are solved by the integral method which encompasses the Gaussian profiles of velocity and density. The action of waves is incorporated into the equations of motion as an external force and a new exact solution is obtained to predict the trajectory, velocity distribution and boundary thickness of the buoyant jet over an arbitrary lateral cross section. It is found that the velocity along the centerline is inversely proportional to the ratio of the momentum of the wave to the buoyant jet. The averaged bound- ary width varies with the fluctuation of the boundary width, the distance from the orifice and the velocity correction function. Owing to the motion of waves, the fluctuation of the boundary width is proportional to the wave steepness. 展开更多
关键词 buoyant jet small amplitude waves radiation stress jet trajectory
下载PDF
In vitro derivation of functional insulin-producing cells from human embryonic stem cells 被引量:38
14
作者 Wei Jiang Yan Shi +9 位作者 Dongxin Zhao Song Chen Jun Yong Jing Zhang Tingting Qing Xiaoning Sun Peng Zhang Mingxiao Ding Dongsheng Li Hongkui Deng 《Cell Research》 SCIE CAS CSCD 2007年第4期333-344,共12页
The capacity for self-renewal and differentiation of human embryonic stem (ES) cells makes them a potential source for generation of pancreatic beta cells for treating type I diabetes mellitus. Here, we report a new... The capacity for self-renewal and differentiation of human embryonic stem (ES) cells makes them a potential source for generation of pancreatic beta cells for treating type I diabetes mellitus. Here, we report a newly developed and effective method, carried out in a serum-free system, which induced human ES cells to differentiate into insulin-producing cells. Activin A was used in the initial stage to induce definitive endoderm differentiation from human ES cells, as detected by the expression of the definitive endoderm markers Sox17 and Brachyury. Further, all-trans retinoic acid (RA) was used to promote pancreatic differentiation, as indicated by the expression of the early pancreatic transcription factors pdxl and hlxb9. After maturation in DMEM/F12 serum-free medium with bFGF and nicotinamide, the differentiated cells expressed islet specific markers such as C-peptide, insulin, glucagon and glut2. The percentage of C-peptide-positive cells exceeded 15%. The secretion of insulin and C-peptide by these cells corresponded to the variations in glucose levels. When transplanted into renal capsules of Streptozotocin (STZ)-treated nude mice, these differentiated human ES cells survived and maintained the expression of beta cell marker genes, including C-peptide, pdxl, glucokinase, nkx6.1, lAPP, pax6 and Tcfl. Thirty percent of the transplanted nude mice exhibited apparent restoration of stable euglycemia; and the corrected phenotype was sustained for more than six weeks. Our new method provides a promising in vitro differentiation model for studying the mechanisms of human pancreas development and illustrates the potential of using human ES cells for the treatment of type I diabetes mellitus. 展开更多
关键词 human embryonic stem cell direct differentiation insulin-producing cell DIABETES
下载PDF
First-principles study of the electronic structure and optical properties of cubic Perovskite NaMgF_3 被引量:3
15
作者 李贞丽 安辛友 +4 位作者 程新路 王雪敏 张红 彭丽萍 吴卫东 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第3期469-474,共6页
The structural, electronic, and optical properties of cubic perovskite NaMgF3 are calculated by plane-wave pseudopo- tential density functional theory. The calculated lattice constant a0, bulk modulus B0, and the deri... The structural, electronic, and optical properties of cubic perovskite NaMgF3 are calculated by plane-wave pseudopo- tential density functional theory. The calculated lattice constant a0, bulk modulus B0, and the derivative of bulk modulus B~ are 3.872/~, 78.2 GPa, and 3.97, respectively. The results are in good agreement with the available experimental and theo- retical values. The electronic structure shows that cubic NaMgF3 is an indirect insulator with a wide forbidden band gap of Eg = 5.90 eV. The contribution of the different bands is analyzed by total and partial density of states curves. Population analysis of NaMgF3 indicates that there is strong ionic bonding in the MgF2 unit, and a mixture of ionic and weak covalent bonding in the NaF unit. Calculations of dielectric function, absorption coefficient, refractive index, electronic energy loss spectroscopy, optical reflectivity, and conductivity are also performed in the energy range 0 to 70 eV. 展开更多
关键词 density functional theory cubic perovskite NaMgF3 electronic properties optical properties
下载PDF
Remarkable Resistance Change in Plasma Oxidized TiOx/TiNx Film for Memory Application 被引量:2
16
作者 吴良才 宋志棠 +4 位作者 饶峰 徐成 张挺 殷伟君 封松林 《Chinese Physics Letters》 SCIE CAS CSCD 2007年第4期1103-1105,共3页
We report the experimental phenomenon of large resistance change in plasma oxidized TiOx/TiNx film fabricated on W bottom-electrode-contact (W-BEC) array. The W-BEC in diameter 26Ohm is fabricated by a 0.18μm CMOS ... We report the experimental phenomenon of large resistance change in plasma oxidized TiOx/TiNx film fabricated on W bottom-electrode-contact (W-BEC) array. The W-BEC in diameter 26Ohm is fabricated by a 0.18μm CMOS technology, and the TiOx/TiNx cell array is formed by rf magnetron sputtering and reactive ion etching. In current-voltage (I- V) measurement for current-sweeping mode, large snap-back of voltage is observed, which indicates that the sample changes from high-resistance state (HRS) to low-resistance state (LRS). In the I-V measurement for voltage-sweeping mode, large current collapse is observed, which indicates that the sample changes from LRS to HRS. The current difference between HRS and LRS is about two orders. The threshold current and voltage for the resistance change is about 5.0- 10^-5 A and 2.5 V, respectively. The pulse voltage can also change the resistance and the pulse time is as shorter as 30 ns for the resistance change. These properties of TiOx/TiNx film are comparable to that of conventional phase-change material, which makes it possible for RRAM application. 展开更多
关键词 RANDOM-ACCESS MEMORY THIN OXIDE-FILMS GE2SB2TE5 FILMS ELECTRICAL-PROPERTIES NEGATIVE RESISTANCE NIO FILMS
下载PDF
Numerical simulation of dynamic process for liquid film spreading by lattice Boltzmann method and its experimental verification 被引量:2
17
作者 刘邱祖 寇子明 韩振南 《Journal of Central South University》 SCIE EI CAS 2014年第8期3247-3253,共7页
Combined with the kinetic model of liquid film spreading, a new numerical method of solid-liquid-gas three-phase flow was developed for the moving of contact line, which was a hybrid method of computational fluid dyna... Combined with the kinetic model of liquid film spreading, a new numerical method of solid-liquid-gas three-phase flow was developed for the moving of contact line, which was a hybrid method of computational fluid dynamics and lattice Boltzmalm method (LBM). By taking the effect of molecule force in droplet and the wall surface on liquid film into account, the changing law of contact angle with different surface tensions was analyzed on glass and aluminum foil surfaces. Compared with experimental results, the standard deviation by using LBM is less than 0.5°, which validates the feasibility of LBM simulation on the dynamic process of liquid film spreading. In addition, oscillations are discovered both at the initial and end phases. The phenomenon of retraction is also found and the maximum retraction angle is 7.58°. The obtained result shows that the retraction is proved to be correlative with precursor film by tracking the volume change of liquid film contour. Furthermore, non-dimensional coefficient 2 is introduced to measure the liquid film retraction capacity. 展开更多
关键词 liquid film spreading contact angle lattice Boltzmann method (LBM) retraction phenomenon numerical simulation
下载PDF
Friction and Wear Behaviors of Ti/Cu/N Coatings on Titanium Alloy Surface by DC Magnetron Sputtering 被引量:3
18
作者 李军霞 PANG Xiaoxu +1 位作者 范爱兰 ZHANG Huiqiao 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2017年第1期140-146,共7页
Ti/Cu/N coatings with different Cu contents were deposited on titanium alloy surface by the DC magnetron sputtering technique.XPS and FESEM were employed to characterize the composition and structure of the coating on... Ti/Cu/N coatings with different Cu contents were deposited on titanium alloy surface by the DC magnetron sputtering technique.XPS and FESEM were employed to characterize the composition and structure of the coating on the Ti6A14 V substrates.In addition,The adhesion force,friction,and wear properties of the Ti/Cu/N coatings were investigated.The experimental results showed that the coarse particles of the coatings would grow more and the surface roughness increased with the increase of copper content in the coatings;The coatings showed a strong adhesion force;The friction coefficient of the coating of the samples was less than the substrate,reaching 0.19 at least.The wear resistance of the coatings could be improved by optimizing and controlling the relative content of Ti,Cu,N elements on the titanium alloy surface,especially the 10.98 at%contents of the copper.The sample C2 kept the best wear resistance. 展开更多
关键词 titanium alloy substrate DCMS coating FRICTION WEAR
下载PDF
Zone plate design for generating annular-focused beams 被引量:1
19
作者 Yong Chen Lai Wei +3 位作者 Qiang-Qiang Zhang Quan-Ping Fan Zu-Hua Yang Lei-Feng Cao 《Chinese Physics B》 SCIE EI CAS CSCD 2020年第10期250-254,共5页
Annular-focused beams have attracted attention because of their novel properties and applications in optical trapping, high resolution microscopy, and laser-induced periodic surface structuring. Generation of this bea... Annular-focused beams have attracted attention because of their novel properties and applications in optical trapping, high resolution microscopy, and laser-induced periodic surface structuring. Generation of this beam is very important and necessary. In this article, a novel design of zone plate for forming the annular-focused beams is proposed. The design principle is introduced, and the characteristics of zone plate are analyzed by numerical simulation. The result shows that the zone plate can form a monochromatic ring-shaped intensity distribution in the focal plane. And the design method is also generally suitable for designing the other optical elements to generate the annular-focused beams. 展开更多
关键词 zone plate diffractive optical elements annular focused beam laser-induced periolic surface structuring
下载PDF
Lithium chloride ameliorates learning and memory ability and inhibits glycogen synthase kinase-3 beta activity in a mouse model of fragile X syndrome 被引量:3
20
作者 Shengqiang Chen Xuegang Luo +6 位作者 Quan Yang Weiwen Sun Kaiyi Cao Xi Chen Yueling Huang Lijun Dai Yonghong Yi 《Neural Regeneration Research》 SCIE CAS CSCD 2011年第31期2452-2459,共8页
In the present study,Fmr1 knockout mice (KO mice) were used as the model for fragile X syndrome.The results of step-through and step-down tests demonstrated that Fmr1 KO mice had shorter latencies and more error cou... In the present study,Fmr1 knockout mice (KO mice) were used as the model for fragile X syndrome.The results of step-through and step-down tests demonstrated that Fmr1 KO mice had shorter latencies and more error counts,indicating a learning and memory disorder.After treatment with 30,60,90,120,or 200 mg/kg lithium chloride,the learning and memory abilities of the Fmr1 KO mice were significantly ameliorated,in particular,the 200 mg/kg lithium chloride treatment had the most significant effect.Western blot analysis showed that lithium chloride significantly enhanced the expression of phosphorylated glycogen synthase kinase 3 beta,an inactive form of glycogen synthase kinase 3 beta,in the cerebral cortex and hippocampus of the Fmr1 KO mice.These results indicated that lithium chloride improved learning and memory in the Fmr1 KO mice,possibly by inhibiting glycogen synthase kinase 3 beta activity. 展开更多
关键词 fragile X syndrome Fmr1 knockout mice step-down test step-through test learning and memory glycogen synthase kinase 3 beta lithium chloride
下载PDF
上一页 1 2 6 下一页 到第
使用帮助 返回顶部