急性轻中度缺氧EEG信号的复杂度研究

建立了一个急性高空缺氧实验模型,记录了四种不同高度条件下从缺氧前(正常呼吸)到缺氧后30分钟时的EEG,分析了其复杂度。发现缺氧引起复杂度明显变化,随时间和高度增加,一定程度缺氧可使EEG复杂度低于正常。表明EEG复杂度对脑缺氧较为敏感,可用于缺氧程度进行评估,有望成为临床诊断的一个指标。     

缺氧对大鼠海马脑片诱发电位的影响

在脑缺氧损伤的研究中,离体海马切片既可排除血脑屏障,又保持原有神经环路,所得实验结果接近在体实验,是研究脑缺氧的理想模型。近几年来国外已有人报道了缺氧时海马脑片诱发电位的变化;但同时用两个脑片比较不同程度的低氧对脑片诱发电位的影响,却少有报道。本实验采用自行设计的双孔脑片电生理实验系统,用不同浓度的低氧混合气造成不同程度的缺氧环境,以探明不同缺氧程度影响脑片电反应的时间曲线,寻求海马脑片缺氧损伤的特征性反应与不可逆损伤发生的临界值。     

藏波罗花提取物对小鼠耐缺氧作用的研究

采用不同方法建立小鼠常压缺氧模型、亚硝酸钠中毒模型及急性脑缺血性缺氧模型,对藏波罗花提取物的耐缺氧活性进行研究。以0.5%羧甲基纤维素钠溶液为空白对照、盐酸普萘洛尔为阳性对照药,设置藏波罗花60%乙醇提取物、95%乙醇提取物的5g/kg、10g/kg、15g/kg三个剂量的给药组,通过观察小鼠存活时间,研究藏波罗花提取物对小鼠缺氧损伤的保护作用。结果显示,与空白对照组相比较,藏波罗花提取物各剂量组均能明显延长小鼠在常压缺氧、亚硝酸钠中毒及急性脑缺血性缺氧条件下的存活时间(P<0.05),表明藏波罗花提取物具有一定的耐缺氧活性,可提高实验小鼠的耐缺氧能力。     

西藏芫根提取物对小鼠抗缺氧作用的初步研究

实验研究西藏芫根提取物的抗缺氧活性.通过建立小鼠常压缺氧模型、急性脑缺血性缺氧模型以及亚硝酸钠中毒模型,以蒸馏水作为空白对照,盐酸普萘洛尔作为阳性对照,观察芫根水、65%乙醇及95%乙醇提取物的10 g/kg、15 g/kg和20 g/kg剂量组对小鼠缺氧的保护作用,同时观察各提取物10 g/kg剂量组对红细胞数量和血红蛋白含量的影响.结果表明,芫根水提取物、65%乙醇提取物及95%乙醇提取物均能明显延长模型小鼠在常压缺氧、急性脑缺血性缺氧及亚硝酸钠中毒时的存活时间,并可增加外周血象中红细胞数与血红蛋白含量,显示芫根提取物具有抗缺氧活性.     

基于斑马鱼模型和动态分子对接技术探讨西洋参抗缺氧作用及潜在靶点CSCD

本研究利用斑马鱼模型和动态分子对接技术研究西洋参抗缺氧(hypoxia)的作用及潜在靶点。以AB系斑马鱼为实验动物,无水硫酸钠为造模剂诱导形成斑马鱼幼鱼缺氧模型,综合评价西洋参的抗缺氧作用。借助网络药理学技术筛选西洋参活性成分以及缺氧相关共有靶点;并使用STRING平台和Cytoscape 3.8.2软件构建蛋白-蛋白作用网络图,寻找西洋参抗缺氧可能的潜在靶点;利用动态分子对接技术验证活性成分与关键靶点的结合能力和稳定性。斑马鱼体内实验显示,西洋参提取物可明显增加斑马鱼在缺氧条件下的存活率,减轻因缺氧导致的神经行为状态(P<0.05),且呈剂量依赖性相关。共筛选获得西洋参7个潜在活性成分和5个抗缺氧潜在靶点;动态分子对接结果显示,西洋参关键活性成分与靶点之间有良好的结合能力,其中TNF、HSP90AA1与活性成分稳定结合,可能为西洋参抗缺氧的关键潜在靶点。综上,本实验建立的斑马鱼幼鱼抗缺氧模型可以快速简便地评价西洋参样品的抗缺氧活性,动态分子对接的结果显示该作用可能通过TNF以及HSP90AA1等靶点发挥作用,为后续西洋参抗缺氧机制研究提供了参考依据。     

小白鼠缺氧耐受形成中不同脑区一氧化氮水平的变化

本研究组的研究证实,在重复缺氧产生缺氧耐受过程中,小白鼠体内通过某些机制的调节,减少了全脑组织ＮＯ合成。本实验通过观察小鼠在缺氧耐受形成中不同脑区ＮＯ水平的变化,旨在进一步探讨缺氧耐受产生的机制。1　材料和方法(1)试剂　4Ｈｙｄｒｏｘｙｃｏｕｍａｒｉｎ(4羟基香豆素,Ｓｉｇｍａ公司),乙腈(中国科学院上海脑研所,上海脑海生物科技公司)。(2)方法　①缺氧耐受模型　选体重为(18～22)ｇ昆明小白鼠雌雄不拘,随机分组:正常对照组、1次缺氧组、4次缺氧组(ｎ=10～13)。1次缺氧组、4次缺氧组,按急性重复缺氧方法,将小白鼠置于含有新鲜…     

缺氧诱导因子与肺癌关系研究进展

缺氧诱导因子(Hypoxia-inducible factors,HIFs)是在缺氧条件下广泛存在于人和哺乳动物体内的一种转录因子,在细胞的增殖、存活、血管发生、新陈代谢、肿瘤侵袭和转移等过程中起着重要作用。缺氧是实体瘤的一个重要特征,缺氧诱导因子与肿瘤的发生、发展关系密切,通过分析缺氧诱导因子与肺癌的关系,为研发新靶点的肺癌药物奠定一定的理论基础。     

茶多酚对大鼠慢性缺氧损伤保护的实验研究

大鼠在高原环境模拟舱内间断缺氧及注射CoCl2溶液以建立红细胞增多症模型,实验分4组：平原组、慢性缺氧组、高剂量TP＋慢性缺氧组、低剂量TP＋慢性缺氧组,研究茶多酚对慢性缺氧诱导的大鼠红细胞增多症及心肌缺氧损伤的影响．结果显示,茶多酚能够显著抑制缺氧大鼠的红细胞数、血红蛋白和红细胞压积的增加,降低骨髓增生程度,减小缺氧大鼠心室重量指数,增加缺氧大鼠Hermannnwillson指数,同时经茶多酚处萼的缺氧大鼠心肌损伤程度较单纯缺氧组轻．提示,茶多酚对大鼠红细胞增多症有一定的预防作用,同时茶多酚还能减轻慢性缺氧对大鼠的心肌损伤程度．     

缺氧诱导因子1

缺氧诱导因子1是缺氧诱导细胞所产生的一种蛋白质,由一个120 ku的α亚基和一个91～94 ku的β亚基组成的异源二聚体.在缺氧条件下,促进红细胞生成素和糖酵解酶等基因的转录和表达,维持机体氧稳态.     

缺氧预处理对乳鼠心肌细胞蛋白激酶C活性的影响

在培养的乳鼠心肌细胞缺氧／复氧模型上,观察了缺氧预处理的细胞保护作用及其对细胞蛋白激酶Ｃ活性和蛋白磷酸化的影响。结果表明,ＡＰＣ可减轻心肌细胞的Ｈ／Ｒ损伤;提高细胞存活率,减少细胞脂质过氧化产物生成及细胞内乳酸脱氢酶和蛋白质漏出。模拟ＡＰＣ的短暂缺氧显著激活ＰＫＣ,使心肌细胞内分子量为６６ｋＤ和３１ｋＤ的蛋白条带＾３２Ｐ掺入增加;ＰＫＣ抑制剂Ｈ７完全消除ＡＰＣ对心肌细胞的保护作用,并抑制了短暂缺氧     

生物体微弱磁场检测技术在某部特殊作业人员健康评估中的应用研究

目的:研究某部特殊作业人员的健康状况,为有针对性地提出防护措施提供参考依据。方法:随机抽取某部不同工作岗位的特殊作业人员145名,进行生物体微弱磁场检测分析,以获取包括疲劳、免疫、睡眠、脑机能、血压、心脏、消化、肝胆、泌尿生殖、呼吸、运动、钙代谢、糖代谢、脂代谢、嘌呤代谢等15个系统在内的108项健康评估检测指标。对于每一项指标,仪器自带有其正常值范围,凡低于下限或高于上限的指标被视为异常。结果:所测特殊作业人员总体在钙代谢系统、消化系统、心脏系统、血压系统、呼吸系统、运动系统、免疫系统等七个系统存在不适症状的较为突出,其中钙代谢失衡的占比83.45%,脾胃不和的占比78.62%,心脏功能欠佳的占比72.41%,血压不稳的占比64.14%,咽喉不适的占比59.31%,骨关节不适的占比58.62%,免疫功能下降的占比51.72%。出现运动系统"颈椎疾患"症状的人数占比,实验组明显高于对照组(P0.05)。结论:特殊作业环境可能会影响作业人员的身体健康,应采取有效的安全防护措施,以减弱或消除有毒有害化学物质污染、强噪声、电磁辐射等对人体健康的影响。     

抗氧化乳酸菌在体外结肠环境清除羟自由基的研究

目的利用鼠肝匀浆经Fe^2＋ -VitC诱导产生丙二醛（MDA）为模型研究29株乳酸菌的抗氧化活性。方法建立体外模拟结肠发酵体系,分析3株具有不同抗氧化能力的乳酸菌（Lactobacillus paracasei Fn032,Laaobacillus rhamnosus GG,Lactobacillus sp．Fn001）在正常结肠和铁过载结肠模型中清除羟自由基效果及对肠球菌增殖的的影响,并检测3株菌螯合亚铁离子能力及其无细胞提取物超氧化物歧化酶（SOD）活性。结果体外结肠体系中羟自由基含量与肠球菌数量有显著相关性。在正常结肠环境中,3株乳酸菌清除羟自由基能力与其SOD活性一致,但与其抑制肠球菌增殖能力和螯合亚铁离子能力不一致。在高铁结肠环境中,3株乳酸菌清除羟自由基能力与它们抑制肠球菌增殖能力和螯合亚铁离子能力一致,但与SOD活性不一致。结论正常条件下乳酸菌可通过产生抗氧化酶来清除结肠自由基,铁过载条件则可增强具有铁螯和能力乳酸菌的抗氧化活性。     

Uptake of Glutamate and Cystine in C-6 Glioma Cells and in Cultured Astrocytes

The uptake of glutamate in rat glioma C-6 cells and cultured astrocytes derived from rat cerebral hemispheres was found to be mediated by a Na(+)-dependent and a Na(+)-independent system. The Na(+)-dependent system was inhibited by aspartate and was consistent with the commonly occurring system designated system X-AG. The Na(+)-independent system was inhibited by cystine and was consistent with system x-c described in various types of cells in the periphery. It was also found that quisqualate selectively and competitively interfered with the Na(+)-independent glutamate uptake. In C-6 cells, the glutamate uptake via systems X-AG and x-c accounted for approximately 35% and 55% of the total uptake, respectively, at 0.05 mM glutamate. In cultured astrocytes, the glutamate uptake via system X-AG was very potent, whereas the uptake via system xc- was relatively weak and its contribution to the total uptake of glutamate seemed almost negligible. However, in both C-6 cells and astrocytes, system xc- was necessary for the uptake of cystine, another substrate of system xc-. Cystine in the culture medium was an essential precursor of glutathione, and the inhibition of the cystine uptake by excess glutamate as a competitor led to a severe deficiency in glutathione, followed by cell degeneration.     

An on-line advisory control system for the lactic acid fermentation process

A fuzzy expert system was developed for online diagnosing and controlling of bioprocesses. The system was constructed in object-oriented Smalltalk/V for diagnosing and controlling of bioprocesses. Lactic acid fermentation with an industrial strain ofLactobacillus casei was chosen as the model system. The performance of the fuzzy expert system and the knowledge base utilizing experts' knowledge and several facts obtained from the experiments were successfully validated with on-line fermentations. The fuzzy expert system could diagnose a fault on-line and give reasonable advice to the process operator. In order to achieve the diagnosing faculty, a database, a knowledge base, and both backward and forward chaining procedures were implemented employing the object-oriented programming environment. A defuzzifier was implemented in the system to achieve on-line control. In order to realize a decision-making system with a human operator and a fuzzy expert system, a new control strategy namedAdvice was also introduced. Several cultivations were carried out in order to collect knowledge on the effects concerned with inoculum properties to the process and to construct a database including standard time-course profiles. The performance of the fuzzy expert control system was successfully tested with on-line experiments.Visiting scientist from HUT at RIKEN     

草原鼢鼠土丘与不同根系类型植物的关系

本研究于2013-2015年的5月（春季）和9月（秋季）,在锡林浩特市南部白银库伦牧场的天然草地监测草原鼢鼠（Myospalax aspalax）生境中植被情况及新旧土丘数量,采用偏冗余分析的方法研究了新旧土丘数量与植物地上生物量的干重、株丛数和物种数之间的关系。结果表明：5月鼢鼠新土丘数量与轴根型、根蘖型植物呈正相关且具有较大解释量。鼢鼠旧土丘数量与疏丛型植物呈正相关,与轴根型和根蘖型植物呈负相关,且具有较大解释量。9月鼢鼠新土丘数量与疏丛型、密丛型和根蘖型植物呈正相关且解释量较大。鼢鼠旧土丘与疏丛型、密丛型和根蘖型植物呈正相关且解释量较大。这些结果说明草原鼢鼠的造丘活动和微栖息地选择和食物资源有关,存在季节差异。轴根型和根蘖型植物对鼢鼠的春季活动有重要影响;疏丛型、密丛型和根蘖型植物对鼢鼠的秋季活动有重要影响。     

Comparative assessment of the resistance of the unstirred water layer to solute transport between two different intestinal perfusion systems

The resistance of the unstirred water layer to solute transport was estimated in two different intestinal single-pass perfusion systems for a comparative study, using D-glucose as a model compound. One is a well established perfusion system in anesthetized rats as a standard (system A). The other is the one in unanesthetized rats for comparison (system B). It was demonstrated that in system B as well as in system A the resistance of the unstirred water layer to D-glucose transport should be taken into account and this resistance, accordingly, the effective thickness of the unstirred water layer (delta) which is assumed to be in proportion to its resistance, could be described as a function of the perfusion rate by using a film model. The delta decreased with increasing perfusion rate and was larger in system A than in system B at each perfusion rate; 785 microns in system A versus 319 microns in system B at the perfusion rate of 0.16 ml/min and 337 microns versus 184 micron at that of 2.95 ml/min. Thus in system B the effective thickness, accordingly, the resistance, of the unstirred water layer was reduced to about 50% of that in system A, but the resistance of the unstirred water layer could still account for 85% of the total resistance at the maximum as far as D-glucose absorption was concerned, while 93% in system A. These results suggest that, compared with perfusion experiments in anesthetized rats (system A), the resistance of the unstirred water layer is reduced but cannot be left out of consideration even if perfusion experiments are performed in unanesthetized rats (system B). And the lower resistance of the unstirred water layer in system B was attributed to a turbulent flow in contrary to a laminar flow in system A.     

克氏原螯虾两种养殖模式的食物网结构及其食性比较

为比较克氏原螯虾(Procambarus clarkii)精养模式和稻虾共作模式下的食物网结构及其食性差异, 对两种养殖模式的基础食源与消费者的δ13C和δ15N进行了分析, 并借助SIBER考察了各自的食物网结构, 定量计算不同饵料对克氏原螯虾食物的贡献率。结果显示: 在采集的19种样品中, 消费者的δ13C值介于–34.22‰—–25.34‰, δ15N值介于2.33‰—8.05‰, 营养级介于1.46—3.64; 在精养模式下克氏原螯虾的营养级(2.34)高于共作模式(1.79)。食物网结构参数对比表明, 两种模式下克氏原螯虾的生态空间利用率接近, 但共作模式的食物网营养结构多样性较高, 群落的营养生态位范围较宽, 食物网的营养冗余程度较低, 不同物种竞争激烈程度较低; 食性分析显示, 在两种模式下克氏原螯虾的δ15N值与其体长、体重具有线性正相关关系, 说明克氏原螯虾营养级随着其体型增大而提高, 另外克氏原螯虾在两种养殖模式中均偏向于摄食动物性饵料, 共作模式中克氏原螯虾饵料来源分布较精养模式更均匀, 其植物性饵料贡献率较精养模式更高。研究表明: 精养模式的物质能量从基础食源传至克氏原螯虾的传递损耗较共作模式要高; 与精养模式相比, 稻虾共作模式中克氏原螯虾更偏向植食性。     

Recirculating bioreactor-separator system for simultaneous biotransformation and recovery of product: Immobilized L-aspartate beta-decarboxylase reactor system

A new combined bioreactor-separator system was designed and its operational feasibility demonstrated in order to develop a bioprocess that enables us to handle simultaneous biotransformation and recovery of product by crystallization. Enzymatic conversion of L-aspartate to L-alanine by L-aspartate beta-decarboxylase from Pseudomonas dacunhae (ATCC 21192) was used as a model system for this study to demonstrate the principles involved in the bioprocess design. Immobilized cells of P. dacunhae containing the enzyme were fluidized in a tapered column type of bioreactor and a filter-crystallizer combination was used as a separator unit in our experimental system.It was found that almost a theoretical yield was achieved, and the process control for both the bioreactor operation and separation was relatively easy. The Production systems, namely, the recirculating bioreactor separator combination system and the conventional batch reactor system, were analyzed and compared based on the results obtained form this study, and it was found that a significant cost reduction, by about 20%, can be achieved when the recirculating bioreactor-separator combination system was employed. Based on these findings, it is anticipated that the conceptual design of the bioreactor-separator combination system evaluated in this study has some potential for industrial application.     

Design a system for measuring individual cow feed intake in commercial dairies

Monitoring individual cow feed intake is necessary for calculating the cow individual feed efficiency. The cost and maintenance time necessary for research systems make them impractical for most of the commercial producers. We developed a measurement system with producer convenience and low investment as key design criteria. The goal of this study was to design the system and validate its ability to rank cows by their feed conversion efficiency in commercial farms. The new system consisted of three principal parts: (a) a hanging weighing system, (b) a visual cow identification system and (c) an automatic cleaning system. The weighing system consisted of hanging a single load cell to provide feed mass measurements. The image-based cow identification system (replacing Radio-Frequency Identification) entailed cameras installed above the feeding area and an image processing algorithm that recognized cows by their collar numbers. The new system worked within normal farm routines: the feed supplying truck distributed the animal feed, and a tractor cleaned feed residual. To validate the accuracy and convenience of the system and to rank the cows by their efficiency, an experiment with six scales and 12 cows was conducted in a research barn, succeeded by eight-scale system in a commercial farm with 16 cows. The feed intake of each cow participating in the experiments was monitored for one month. The validation experiment showed that the system had the following specification: scales were accurate within 120 g; the visual cow identification rate was greater than 96%; feeding duration was accurate to 52 s; and routine farm practices (feed distribution, pushing, and residual removal) continued as usual. The cost for a feeding station (utilized consequently for a number of cows) was about 1 500 USD. An example of application of the system to rank cows by their efficiency under commercial conditions was shown. The system can potentially be used for ranking cows by their efficiency in commercial facilities.     

2',3'-cyclic nucleotide phosphohydrolase activity determined using an image analyzer detection system

The activity of 2',3'-cyclic nucleotide phosphohydrolase (CNPase) was assayed using high-performance thin-layer chromatography (HPTLC) and an image analyzer detection system. The assay system was used to study a possible inhibitory effect by aminoguanidine on CNPase specific activity. One advantage of using a fixed-time HPTLC system over a real-time spectrophotometric system for an enzyme activity study was that apparent inhibition of the enzyme due to interference of the assay system (chromophore inhibition, etc.) was avoided. In addition, due to the increased accuracy of the image analyzer over conventional methods of TLC plate analysis, a rapid and more accurate measurement of HPTLC plates was possible which required only nanomole amounts of substrate. Also, a digital image of each plate analyzed was stored indefinitely in the computer's memory for future reference. The measurements of CNPase specific activity made using this system compared favorably to those found in recent literature.