脂肪胰的研究现状

脂肪胰是近年被提出并研究,与肥胖、非酒精性脂肪性肝病、代谢综合征等多种疾病或病理状态相关的概念,特征为胰腺内脂肪沉积、胰腺实质脂肪变性,以及随之发生的胰腺代谢性异常.研究已证实脂肪胰与2型糖尿病、急性胰腺炎甚至胰腺肿瘤相关.可能是糖、脂代谢紊乱或者代谢综合征的一个早期标志物,还可能是胰腺相关疾病不良结局的预测因素.目前主要以影像学检查为主要诊断方法 .但因了解甚少,故而缺乏统一的命名、诊断标准、治疗共识或指南.本文总结了目前流行病学、病理生理、发病机制、诊断、治疗方面的研究现状,并提出需要进一步研究的方向.陕西省重点研发计划,No.2017SF-274;;陕西省教育厅科研计划,No.12JK0704~

胃食管反流病的个体化诊疗

胃食管反流病(gastroesophageal reflux disease, GERD)的发病率无论在发展中国家还是发达国家均在逐渐升高,尤其是北美和亚洲,疾病谱包括糜烂性反流病或反流性食管炎或糜烂性食管炎、非糜烂性反流病(nonerosive reflux disease, NERD)和Barrett食管三个亚型。GERD的病因、发病机制、临床表现以及对治疗的反应均显示出高度的异质性或个体间差异,特别是NERD和难治性GERD;另外,尽管生物医学、药学技术的研发和快速发展为GERD诊断及治疗提供了越来越多和先进的手段,但仍有一部分患者远期疗效和生活质量的改善尚未达到理想目标。以上因素决定了每一位GERD患者需要一种针对其本人各项医学特征的个体化管理策略及个体化诊疗。GERD的治疗目标是缓解症状,而症状的缓解又直接与生活质量相关,因此健康相关生活质量和患者的满意度可能成为评价GERD疗效的客观标准。本文充分阐述了GERD的个体化诊疗。陕西省重点研发计划,No.2017SF-274;;陕西省教育厅科研计划,No.12JK0704~

高校校园体育文化亮点——啦啦队运动功能研究

19世纪80年代美国校园里就有啦啦队,啦啦队是从美国传入中国,在我国啦啦队是一项新兴的体育运动项目,深受高校广大青少年的喜爱,它具有广阔的发展前景,为了丰富校园体育文化的内涵,促进校园体育文化的建设,促进学生个性发展,发展啦啦队运动项目是推动和繁荣高校校园体育文化的重要途径

Direct experimental evidence for detailed growth of SiO_x nanowire during CVD

在纳米线的制备中,气-液-固(VlS)生长机制得到了人们的广泛认可,但该机制的很多细节还停留在模型阶段.依托实验室自行设计的一台生长条件高度可控的高温化学气相沉积(CVd)系统,采用较为简便的方法,直接在SI片衬底上制备出了SIOX纳米线.通过严格控制实验参数,用离位观测捕捉到了纳米线的催化、形核和长大的一系列过程及其相关细节,并发现纳米线从细到粗的气-液-固(VlS)生长机制.讨论了气-液-固(VlS)机制中气态SI原子的来源以及纳米线的催化、形核和长大过程中的纳米曲率效应和“纳米熟化“现象,取得了对SIOX纳米线VlS催化生长机制的理解的突破.Among the mechanisms for nanowire growths, the vapor-liquid-solid (VLS) mechanism is the most widely accepted.Nevertheless, the growth process and relevant details for the VLS mechanism are not yet fully understood for the complicated nano processes involved.In the present article, with a precise control of temperature, gas flow, pressure, and reaction periods in a home- built high-temperature chemical vapor deposition (CVD) system, detailed processes of catalyzing, nucleation, and growth of the SiOx nanowires and a stepwise non uniformity in diameter of nano- wire were successfully traced.With analysis of these experimental results via nanocurvature and nano ripening effects, a further understanding of the vapor-liquid-solid mechanism, especially the mechanism for formation of the stepwise non uniformity in diameter of nanowires, was achieved for the first time.国家科技计划国际科技合作与交流专项(编号:2008DFA51230);国家重点基础研究发展计划(编号:2007CB936603);国家自然科学基金(批准号:60776007、90401022);中澳科技合作特别基金(编号:20050222);教育部科技重点项目(编号:105099)资

Uptake and Metabolism Kinetics of TBT in Whelk(Thais clavigera)Exposed to Dietary

将牡蛎消化腺分别暴露在1000ng.l-1和100ng.l-1TbT水溶液中4周,然后将染毒的牡蛎消化腺分别投喂疣荔枝螺(THAIS ClAVIgErA)。经过45d的暴露和30d的净化,我们发现雌雄疣荔枝螺的消化和生殖系统能较快地吸收TbT(吸收速率ku=0.004-0.022.d-1),并且其代谢(生物代谢系数bdI=5.59-23.30)和排出速率(净化速率kE=0.024-0.053.d-1)也相对较快,各器官中TbT的代谢产物MbT占了相对较高的比例,因此TbT在食物链传递过程中没有出现生物放大的现象。此外,TbT有逐渐从雌螺消化系统向生殖系统转移的趋势,并且雌螺生殖系统对TbT的吸收和富集能力(ku=0.006-0.022.d-1,生物放大系数bMf=0.181-0.664)要显著强于雄螺(ku=0.004-0.014.d-1,生物放大系数bMf=0.142-0.376),但其代谢和净化速率(bdI=5.59-10.50,kE=0.024-0.025.d-1)却显著低于雄螺(bdI=11.5-12.4,kE=0.031-0.050.d-1),雌螺的生殖系统被认为是TbT转移和富集的潜在靶器官,这对我们今后开展TbT污染的环境监测和评价具有重要的参考价值。Oysters were respectively exposed to 1000 ng·L-1 and 100 ng·L-1 tributyltin(TBT) aqueous for 4 weeks,which was as dietary to feed the female and male Thais clavigera whelks for 45 days.Then these Thais clavigera were depurated for 30 days.The results show that TBT rapidly accumulated in their digestive and reproductive organs(ku=0.004-0.022 d-1).Moreover,elimination and biotransformation of TBT were also rapid(BDI=5.6-23.30,ke=0.024-0.053 d-1).MBT was the dominant metabolite in each tissue.Therefore,bio-magnification of TBT did not occur during the trophic transfer process.Additionally,to females,the mobilization of TBT from digestive to reproductive organs and bioaccumulation of TBT(ku=0.006-0.022 d-1,BMF=0.181-0.664) were more obvious than that of the males.However,lower metabolism and elimination of TBT(BDI=5.6-10.5,ke=0.024-0.025 d-1) in female reproductive organs,which indicated that the reproductive organs of females were the main targets of TBT accumulation.The results are important to the risk assessment of TBT contamination in coastal environments.国家“863”项目No.2007AA09Z126;国家自然科学基金项目No.40476048;20777060;海洋公益性行业科研专项经费;No.20080509

New observations for electron beam-induced instability of single-wall carbon nanotube

利用透射电镜在室温下对不同形态的单壁碳纳米管进行了原位电子束辐照研究.研究发现:在相同的辐照条件下随着辐照时间(或辐照剂量)的增加,两端固定的单壁碳纳米管径向收缩,且收缩速率越来越快;相同直径的轴向弯曲的单壁碳纳米管比平直的单壁碳纳米管更加不稳定;一端固定另端自由的单壁碳纳米管轴向收缩,但其直径基本不变.利用单壁碳纳米管纳米曲率效应和能量束诱导非热激活效应,对上述单壁碳纳米管的不稳定性现象进行了新的、合理的解释.The nanoinstability of single-wall carbon nanotube(SWCNT) under electron beam irradiation is systematically investigated by in-situ transmission electron microscopie observation at room temperature.Under the same irradiation condition,it is found that with the increase of irradiation time(or electron dose),the SWCNT whose two ends are fixed at ropes of nanotubes shrinks in its radial direction with an increasingly faster rate;the curved SWCNT is more instable than the straight one with the same diameter;the SWCNT with a free capped end but the other end fixed at a rope of nanotubes shrinks in the axial direction but almost keeps its diameter unchanged.All experimental phenomena could be well accounted for by new concepts of the nanocurvature of SWCNT and by the electron beam-induced athermal activation.国家科技计划国际科技合作与交流专项(批准号:2008DFA51230);国家重点基础研究发展计划(批准号:2007CB936603);国家自然科学基金(批准号:11074207;60776007);教育部高等学校博士学科点专项科研基金(批准号:20100121110023)资助的课题---

CVD制备SiO_x纳米线的各个生长阶段的直接实验证据

在纳米线的制备中,气-液-固(VLS)生长机制得到了人们的广泛认可,但该机制的很多细节还停留在模型阶段.依托实验室自行设计的一台生长条件高度可控的高温化学气相沉积(CVD)系统,采用较为简便的方法,直接在Si片衬底上制备出了SiO_x纳米线.通过严格控制实验参数,用离位观测捕捉到了纳米线的催化、形核和长大的一系列过程及其相关细节,并发现纳米线从细到粗的气-液-固(VLS)生长机制.讨论了气-液-固(VLS)机制中气态Si原子的来源以及纳米线的催化、形核和长大过程中的纳米曲率效应和"纳米熟化"现象,取得了对SiO_x纳米线VLS催化生长机制的理解的突破

XNF光亮镍铁合金电镀工艺

本文着重就光亮剂XNF—1和温度对镀液的整平能力、深镀能力、分散能力、阴极极化和镀层组成及硬度的影响进行了初步研究