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1.
探讨了干扰素调节因子7(IRF7)的表达与中国汉族人群系统性红斑狼疮(SLE)的相关性.运用实时荧光定量聚合酶链式反应的方法分别测定疾病患者与正常对照组外周血IRF7mRNA的表达水平,并与血清中干扰素水平、干扰素积分以及SLEDAI积分作相关性分析.结果发现,患者外周血IRF7mRNA的表达水平较正常对照组的明显增高,且其与血清中干扰素水平、干扰素积分以及SLEDAI积分均呈正相关.由此可知,IRF7表达的增高可能促使干扰素通路异常激活,从而导致系统性红斑狼疮的发生.  相似文献   

2.
目的:探讨骨桥蛋白(OPN)在卵巢肿瘤组织的表达及其与恶性肿瘤侵袭转移的关系。方法:采用免疫组织化学方法测定OPN在48例卵巢恶性肿瘤组织、8例卵巢临界恶性肿瘤组织、20例卵巢良性肿瘤组织及10例卵巢正常组织中的表达。结果:OPN在卵巢恶性肿瘤组织表达强度为0.485±0.134,显著高于卵巢正常组织及卵巢临界恶性及良性肿瘤组织表达强度(0.122±0.023,0.243±0.076及0.168±0.045,P<0.01);OPN的表达与恶性肿瘤的临床期别及分化程度相关,而与细胞组织学类型无关。结论:OPN在卵巢肿瘤的发生发展中起重要作用,并与卵巢恶性肿瘤的侵袭转移相关。  相似文献   

3.
microRNAs, a class of small non-coding regulatory RNAs, are involved in oncogenesis and cancer development. Studies have shown that aberrant miRNA expression occurs in breast cancer and is associated with specific clinicopathological features. Some miRNAs might act as suppressor genes or oncogenes, which can be considered as novel markers for breast cancer diagnosis and as prognostic factors. Here we present a review of recent discoveries on miRNAs involved in breast cancer tumorigenesis, invasion, and metastasis.  相似文献   

4.
分层模糊控制器的解析表达式及自适应控制方法   总被引:1,自引:0,他引:1  
为解决模糊多变量控制中的“维数灾”问题 ,提出了一种 4输入 1输出的分层模糊控制器 ,推导了它的解析表达式。依据分层模糊控制器的解析表达式 ,提出了其设计参数的模型参考自学习方法 ,其中参考模型选取典型二阶系统 ,用梯度法设计自学习律 ,在线学习分层模糊控制器的可调参数 ,以达到最优值。为检验所提出控制策略的有效性 ,将其应用到板球系统的轨迹跟踪问题 ,并进行了仿真实验。仿真实验结果表明 ,这种分层模糊控制器的可调参数少 ,学习算法收敛快 ,控制效果好 ,具有较强的实用性。  相似文献   

5.
通过将Caputo导数和细胞免疫时滞同时引入HIV感染建模,建立了一类分数阶HIV免疫时滞微分方程模型,对其平衡点进行了稳定性分析,获得了感染免疫平衡点稳定对参数要求的充分条件.  相似文献   

6.
综述了有关对脊椎动物促性腺激素释放激素的结构、基因表达与调控的研究进展 .阐明促性腺激素释放激素结构多样性 ,功能多样性 ,及其基因表达与调控 ,并对可能的应用前景作简要阐述  相似文献   

7.
针对一类具有垂直传播的HIV模型,在已讨论了各平衡点的全局稳定性的基础上,对模型施加控制且进行分析,将有效接触率作为控制变量,用范数指标函数作为衡量控制变量的标准得出该模型最优控制元的存在惟一性.  相似文献   

8.
G Bollag  F McCormick 《Nature》1991,351(6327):576-579
The ras-encoded p21ras proteins bind GTP very tightly, but catalyse hydrolysis to GDP very slowly. In humans, two genes encode proteins that stimulate this GTPase activity (GAP, or GTPase-activating proteins), one of relative molecular mass 120,000, referred to as p120-GAP, and another NF1-GAP, which is encoded by the neurofibromatosis type-1 gene. Both GAPs are widely expressed in mammalian tissues. Here we show that although they will both bind oncogenic mutants of p21ras, neither will stimulate their GTPase activity. NF1-GAP binds to the p21ras proteins up to 300 times more efficiently than p120-GAP. The two GAPs are inhibited to different extents by certain lipids: micromolar concentrations of arachidonate, phosphatidate and phosphatidylinositol-4,5-bisphosphate affect only NF1-GAP. This inhibition does not compete with p21ras, and lipid-inactivated NF1-GAP can still bind p21ras. We used the detergent dodecyl maltoside, which inhibits only NF1-GAP, to distinguish between the two activities in cell extracts and found both types present together in several mammalian cell lines. In contrast, GAP activity in extracts of Xenopus oocytes was not affected by dodecyl maltoside. By these criteria, the mammalian cells contain both GAP activities and the oocytes have only p120-like GAP activity. These results indicate that more than one GAP regulates p21ras in the same cell.  相似文献   

9.
研究一类分数阶HIV/AIDS传染病模型.在该模型中,考虑了人类自身的"意识"在疾病传播中的作用将被.讨论了模型平衡点的稳定性并进行了相应的数值模拟实验.  相似文献   

10.
带协同约束弧的微分Petri网及其仿真   总被引:1,自引:0,他引:1  
为使Petri网中单个库所对变迁的简单逻辑约束关系扩展到多个库所对变迁复杂的协同约束关系,提出了协同约束弧的概念,并将它与微分Petri网相结合,用以对具有状态反馈控制的混杂系统建模.结合一个二阶线性系统的实例,给出了它的带协同约束弧的微分Petri网模型,并用Stateflow和Simulink结合起来对这种带有协同约束弧的微分Petri网描述与仿真.仿真结果表明:在协同约束弧控制下,适时改变控制策略,将系统切换到不同的相空间,从而使不稳定系统最终在目标区域内稳定运行.  相似文献   

11.
Metabolic phenotypes are the products of interactions among a variety of factors-dietary, other lifestyle/environmental, gut microbial and genetic. We use a large-scale exploratory analytical approach to investigate metabolic phenotype variation across and within four human populations, based on 1H NMR spectroscopy. Metabolites discriminating across populations are then linked to data for individuals on blood pressure, a major risk factor for coronary heart disease and stroke (leading causes of mortality worldwide). We analyse spectra from two 24-hour urine specimens for each of 4,630 participants from the INTERMAP epidemiological study, involving 17 population samples aged 40-59 in China, Japan, UK and USA. We show that urinary metabolite excretion patterns for East Asian and western population samples, with contrasting diets, diet-related major risk factors, and coronary heart disease/stroke rates, are significantly differentiated (P < 10(-16)), as are Chinese/Japanese metabolic phenotypes, and subgroups with differences in dietary vegetable/animal protein and blood pressure. Among discriminatory metabolites, we quantify four and show association (P < 0.05 to P < 0.0001) of mean 24-hour urinary formate excretion with blood pressure in multiple regression analyses for individuals. Mean 24-hour urinary excretion of alanine (direct) and hippurate (inverse), reflecting diet and gut microbial activities, are also associated with blood pressure of individuals. Metabolic phenotyping applied to high-quality epidemiological data offers the potential to develop an area of aetiopathogenetic knowledge involving discovery of novel biomarkers related to cardiovascular disease risk.  相似文献   

12.
本文对一般形式的线性齐次微分方程■分别给出了在自变量变换下的不变量组,并讨论了不变量组的应用.本文的结果是文[1]的推广.  相似文献   

13.
14.
Lignin biosynthesis and its molecular regulation   总被引:1,自引:0,他引:1  
Lignin biosynthesis has become increasingly highlighted because it plays an important role in the growth and development of plant, in the systematic evolution of plant and in the human life. Due to the progress in the field of lignin studies in recent years, the lignin biosynthesis pathway has been 修订日期:. Here we discuss some genetic engineering approaches on lignin biosynthesis, and conceive strategy to regulate lignin biosynthesis in order to use lignin resource more efficiently in agricultural and industrial productions.  相似文献   

15.
OWLAN无线网卡的设计及与SIM卡的结合方案   总被引:2,自引:0,他引:2  
简要介绍了OWLAN产生的背景及技术概况.研究了OWLAN中无线网卡的设计过程,进而对无线网卡和SIM卡的结合做了研究,提出了一个初步的技术方案,在方案的设计过程中主要考虑了移动终端鉴权,漫游,计费等方面的问题.  相似文献   

16.
断层带煤体瓦斯地质特征与瓦斯突出的关联   总被引:2,自引:0,他引:2  
针对煤与瓦斯突出煤层开采期间的突出与断层之间的关联问题,采用瓦斯地质方法,通过矿井开采实例研究了井田内断层封闭与开放的瓦斯地质特征,并根据断层附近瓦斯涌出规律判断断层与突出的关系.研究结果表明:断层的开放性与封闭性对煤与瓦斯突出具有控制作用.封闭性断层带附近瓦斯涌出异常增大,构造应力集中、常常封闭有高能瓦斯以及发育的构造煤,为煤与瓦斯突出创造条件;开放性断层带附近具有煤层瓦斯压力相对较低,煤层瓦斯含量较正常下降的特征,而在远离断层面的一侧,伴随有平行断层的条带状煤层应力集中区,其中具有煤层瓦斯压力大、煤层瓦斯含量高的特征.该成果对煤矿在煤层断层带开采瓦斯防治具有一定的理论价值和实用意义.  相似文献   

17.
简要介绍了OWLAN产生的背景及技术概况。研究了OWLAN中无线网卡的设计过程,进而对无线网卡和SIM卡的结合做了研究,提出了一个初步的技术方案,在方案的设计过程中主要考虑了移动终端鉴权,漫游,计费等方面的问题。  相似文献   

18.
To investigate the effects of hypoxic exercise training on microRNA (miRNA) expression and the role of miRNA expression in regulating lipid metabolism, 20 dietary-induced obese SD rats were divided into a normoxic sedentary group (N, n=10) and a hypoxic exercise training group (H, n=10). After four weeks, measurements were taken of body weight, body length, fat mass, serum lipid concentration, miRNAs differentially expressed in rat liver, and gene and protein expression levels of perexisome proliferator activated receptor a (PPARα), fatty acid synthetase (FAS), and carnitine palmitoyl transferase 1A (CPTIA) in rat liver. Body weight, Lee's index, fat mass, fat/weight ratio, and serum levels of total cholesterol (TC) and high density lipoprotein cholesterol (HDL-C) were all significantly lower in the H group than in the N group (P〈0.01). Six miRNAs expressed significantly differently in the liver (P〈0.05). Specifically, expression levels of miR-378b were significantly lower in the H group than in the N group (P〈0.05). Compared with the normoxic sedentary group, hypoxic exercise training resulted in a lower ratio of FAS mRNA to CPTIA mRNA (P〈0.05), as well as lower CPT1A protein levels (P〈0.01), while a higher ratio of FAS to CPT1A protein levels (P〈0.01) was observed. In conclusion, hypoxic training may elevate the resistance of high fat diet induced obesity in rats by reducing the expression of miR-378b, and decrease the fatty acid mitochondrial oxidation in obese rat livers by decreasing the protein expression of CPTIA and increasing the protein expression ratio of FAS/CPTIA.  相似文献   

19.
阐述了序列最优控制算法是针对土木工程结构地震响应振动控制问题中激励不可预知的特点,推导出1 种更为一般的最优控制算法,所获得的最优控制力表达式同时包含了结构响应和地震激励2 部分的影响.该算法增益矩阵与传统的2种最优控制近似算法相比具有时变的特点,提出了在应用该算法进行主动控制Simulink仿真分析时的2种实现方法,并通过AMD控制基准模型对2种实现方法进行了比较,同时也对该算法与现有两种结构最优控制算法的控制效果进行了评价.结果表明,2种实现方法是完全等效的,且在控制效果方面,序列最优控制算法优于现有的2种最优控制算法.  相似文献   

20.
Muscarinic acetylcholine receptors (mAChRs), like many other neurotransmitter and hormone receptors, transduce agonist signals by activating G proteins to regulate ion channel activity and the generation of second messengers via the phosphoinositide (PI) and adenylyl cyclase systems. Human mAChRs are a family of at least four gene products which have distinct primary structures, ligand-binding properties and patterns of tissue-specific expression. To examine the question of whether functional differences exist between multiple receptor subtypes, we have investigated the ability of each subtype to regulate PI hydrolysis and adenylyl cyclase when expressed individually in a cell lacking endogenous mAChRs. We show that the HM2 and HM3 mAChRs efficiently inhibit adenylyl cyclase activity but poorly activate PI hydrolysis. In contrast, the HM1 and HM4 mAChRs strongly activate PI hydrolysis, but do not inhibit adenylyl cyclase, and in fact can substantially elevate cAMP levels. Interestingly, the subtypes that we find to be functionally similar are also more similar in sequence. Our results indicate that the different receptor subtypes are functionally specialized.  相似文献   

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