共查询到20条相似文献,搜索用时 31 毫秒
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凝血系统相关基因突变及表达异常与高血凝 总被引:2,自引:0,他引:2
摘要高血凝是动脉粥样硬化(As)的危险因子,在As的发展中具有重要作用。凝血系统、抗凝系统、纤溶系统及其它相关基因的突变及表达异常导致高血凝的产生。凝血系统的凝血因子V基因、凝血酶原基因、组织因子基因,抗凝系统的血栓调节蛋白基因、抗凝血酶Ⅲ基因,纤溶系统的纤溶酶原激活物抑制剂-1基因,均与高血凝密切相关。 相似文献
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草地农业生态系统中的系统耦合与系统相悖研究动态 总被引:12,自引:3,他引:12
综述了草地农业生态系统中系统耦合与系统相悖的内涵及其发展过程 ,该领域的研究前沿与发展趋势。草地农业生态系统的种间耦合、不同生产层之间的纵向耦合、不同草地农业生态系统之间的横向耦合、系统的界面过程与系统耦合、生物的时间地带性与系统耦合是草地农业生态系统中的系统耦合与系统相悖理论与实践研究的 5个前沿领域。对系统相悖量化工作将是今后系统耦合、系统相悖理论研究的关键 ,综合运用多种非线性科学方法解决草地农业生态系统的系统耦合和系统相悖的数量化工作可能是系统耦合和系统相悖理论研究和实践的一个非常有前途的方向。 相似文献
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Qi Shen Jie Li Zhan Zhang Shuang Guo Qiuhong Wang Xiaorui An Haocai Chang 《International journal of biological sciences》2022,18(1):386
Responding to the coronavirus disease 2019 (COVID-19) pandemic has been an unexpected and unprecedented global challenge for humanity in this century. During this crisis, specialists from the laboratories and frontline clinical personnel have made great efforts to prevent and treat COVID-19 by revealing the molecular biological characteristics and epidemic characteristics of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Currently, SARS-CoV-2 has severe consequences for public health, including human respiratory system, immune system, blood circulation system, nervous system, motor system, urinary system, reproductive system and digestive system. In the review, we summarize the physiological and pathological damage of SARS-CoV-2 to these systems and its molecular mechanisms followed by clinical manifestation. Concurrently, the prevention and treatment strategies of COVID-19 will be discussed in preclinical and clinical studies. With constantly unfolding and expanding scientific understanding about COVID-19, the updated information can help applied researchers understand the disease to build potential antiviral drugs or vaccines, and formulate creative therapeutic ideas for combating COVID-19 at speed. 相似文献
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Transporters and their roles in LAB cell physiology 总被引:3,自引:0,他引:3
Poolman B 《Antonie van Leeuwenhoek》2002,82(1-4):147-164
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基因表达的调控是分子生物学研究的一个重要问题,也是基因治疗和基因功能研究的重要手段。诱导性基因表达系统可以从时间上调控基因的表达,是基因治疗和基因功能研究的重要工具之一。其中,四环素诱导基因表达系统(tetracycline inducible expression system,Tet system)是应用最广泛的一种,它可以在时间和空间上对基因进行严谨和高效地诱导表达。基于该系统获得了不同用途的转基因动物,这些模型动物的建立为研究特定基因的功能及其在疾病发生中的作用打下了实验基础。现就四环素诱导表达系统的原理和在小鼠模型上的研究应用做一综述。 相似文献
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刘明力 《中国生物工程杂志》2007,27(1):131-136
发酵是科学技术,验证是科学的监督管理,技术离不开管理,管理也离不开技术,技术如果想飞得更稳,飞得更高,则必须插上科学管理的翅膀。介绍了验证的基础理论,将验证的理念融入到发酵技术中,建立发酵系统的验证思维,阐述了发酵系统验证由人员的确立、方案的制订、验证的实施到报告的总结的全过程。事实证明,建立发酵系统的验证是发酵过程中不可缺少的环节,也是执行GMP的要求,经过验证的发酵系统才是可靠的系统,经过验证的发酵工艺才是稳定的生产工艺。 相似文献
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在真核细胞中已发现两条主要降解途径,即自噬系统和蛋白酶体系统.长期以来,这两条降解途径一直被认作是完全独立的路径,然而最近的证据强烈提示,这两条主要降解途径之间相互联系.其中,发现干扰这两条途径的任一条可影响另一条途径的活性,抑制蛋白酶体可刺激自噬活性.同时发现泛素的作用比先前想象更广泛,不仅具有标记蛋白酶体降解蛋白质这一 “经典作用”,还涉及自噬-溶酶体途径降解底物泛素化,是这些主要降解途径的共同标签.这些降解系统分享某些底物和调节分子,显示协同作用,在某些背景下,显示补偿功能.降解系统之间的协同和补偿作用在许多细胞过程中显得至关重要.因此这些降解系统异常或联系失常不仅导致细胞功能的异常,而且也与多种重要疾病的发生和发展密切相关.对这些降解途径功能及其联系的深入了解可拓展人们对这些降解途径的认识,有助于对多种细胞分解代谢过程的深入理解,也有助于相关新药的研发. 相似文献
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The phylogenetic position of the Ectoprocta within the Lophotrochozoa is discussed controversially. For gaining more insight into ectoproct relationships and comparing it with other potentially related phyla, we analysed the myoanatomy and serotonergic nervous system of adult representatives of the Phylactolaemata (Plumatella emarginata, Plumatellavaihiriae, Plumatella fungosa, Fredericella sultana). The bodywall contains a mesh of circular and longitudinal muscles. On its distal end, the orifice possesses a prominent sphincter and continues into the vestibular wall, which has longitudinal and circular musculature. The tentacle sheath carries mostly longitudinal muscle fibres in Plumatella sp., whereas F. sultana also possesses regular circular muscle fibres. Three groups of muscles are associated with the lophophore: 1) Lophophoral arm muscles (missing in Fredericella), 2) epistome musculature and 3) tentacle musculature. The epistome flap is encompassed by smooth muscle fibres. A few fibres extend medially over the ganglion to its proximal floor. Abfrontal tentacle muscles have diagonally arranged muscle fibres in their proximal region, whereas the distal region is formed by a stack of muscles that resemble an inverted ‘V’. Frontal tentacle muscles show more variation and either possess one or two bases. The digestive tract possesses circular musculature which is striated except at the intestine where it is composed of smooth muscle fibres. The serotonergic nervous system is concentrated in the cerebral ganglion. From the latter a serotonergic nerve extends to each tentacle base. In Plumatella the inner row of tentacles at the lophophoral concavity lacks serotonergic nerves. Bodywall musculature is a common feature in many lophotrochozoan phyla, but among other filter feeders like the Ectoprocta is only present in the ‘lophophorate’ Phoronida. The longitudinal tentacle musculature is reminiscent of the condition found in phoronids and brachiopods, but differs to entoproct tentacles. Although this study shows some support for the ‘Lophophorata’, more comparative analyses of possibly related phyla are required. J. Morphol., 2011. © 2011 Wiley Periodicals, Inc. 相似文献
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生态系统工程与现代混农林业生产体系 总被引:11,自引:0,他引:11
当今世界面临着人口剧增,能源短缺和环境恶化等危机。在第三世界人口飞速增长,耕地需求扩大,毁林种粮,弃林从牧的问题十分严重,引起土壤肥力衰退,水土流失,气候失调,环境恶化,从而阻碍了农牧业的发展。为了保护森林,维护环境,解决农林、牧林业之间的矛盾,有效的途径就是将农、林、牧业有机地结合起来,建立林-农复合生态系统。因而发展农林业在国际上受到充分重视,早于1977年就成立了国际农林业研究中心(ICRAF),推动农林业的研究与生产。我国对农林业的研究与推广近年来也有长足的发展。预计农林业将成为现代农业和林业的发展趋势之一。为此,我们请南京林业大学熊文愈教授和姜志林教授负责组稿、审稿和修改论文,共汇集农林业的论文16篇。这些论文部分反映了当前我国农林业的理论研究工作和实际生产经验。现经本刊编辑,计划作为农林业专题在本刊分四期刊出,以引起广大读者对农林业的重视。在此我们对熊文愈和姜志林二位教授的积极支持表示衷心的感谢。 相似文献
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通过野外交配系统试验和传粉昆虫观察, 以铃铛子( Anisodus luridus) 和赛莨菪( A. carniolicoides)为研究对象, 探讨了山莨菪属内自交亲和系统的进化与传粉昆虫的转变。结果表明, 铃铛子和赛莨菪均属于自交完全亲和的类群, 但两个种的自动自交能力均不强, 而且都存在传粉限制。北方黄胡蜂( Vespula rufarufa) 和石长黄胡蜂( Dolichovespula saxonica) 分别是铃铛子和赛莨菪的主要传粉昆虫, 自然状态下两种昆虫的传粉效率均比较高, 但两种昆虫访问两种植物时传递花粉的方式不同, 其中北方黄胡蜂主要促进了铃铛子的花间传粉, 而石长黄胡蜂访花引起赛莨菪同一朵花内的传粉。通过与该属的另一种植物山莨菪(A. tanguticus) 的传粉机制比较, 发现在山莨菪属的物种分化过程中, 由自交不亲和转变为自交完全亲和, 传粉昆虫也发生了转变, 证明了自交亲和系统存在于起源较晚的类群中。高山环境中频繁且不可预测的降雨可能降低了传粉昆虫的活动能力, 进而导致铃铛子和赛莨菪均存在传粉限制。 相似文献
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Studies were performed to develop a sub-100 nm biodegradable colloidal system for the efficient delivery of drugs and diagnostic agents to the lymphatic system. Nanospheres of poly(lactide-co-glycolide) were prepared by interfacial polymer deposition. The nanospheres were coated with block co-polymers in order to modify their surface characteristics. Radiolabelling of the nanospheres for in vivo tracing was achieved by the incorporation of the lipophilic complex 111In-oxine during nanosphere preparation. In vitro stability of the radiolabelled nanospheres was determined in rat serum at 37°C. The lymphatic distribution of the nanospheres was determined after subcutaneous administration to the rat. Lymphatic uptake of all coated systems was enhanced compared to the uncoated nanospheres, and a maximal uptake of 17% of the administered dose in the regional lymph nodes was achieved. These observations suggest that the nanospheres are suitable for diagnostic and therapeutic applications in clinical and experimental medicine. 相似文献
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Maternal separation and early stress cause long‐lasting effects on dopaminergic and endocannabinergic systems and alters dendritic morphology in the nucleus accumbens and frontal cortex in rats
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Antonio Romano‐López Mónica Méndez‐Díaz Fabio García García Citlalli Regalado‐Santiago Alejandra E. Ruiz‐Contreras Oscar Prospéro‐García 《Developmental neurobiology》2016,76(8):819-831
A considerable amount experimental studies have shown that maternal separation (MS) is associated with adult offspring abnormal behavior and cognition disorder. Accordingly, this experimental procedure has been proposed as a predictor for alcohol and drug dependence based on the neurodevelopmental soon after birth. Endocannabinoid system (eCBs) has been implicated in reward processes, including drug abuse and dependence. MS and associated stress causes changes in the eCBs that seem to facilitate alcohol consumption. In this study, we seek to evaluate potential morphological changes in neurons of the frontal cortex (FCx) and nucleus accumbens (NAcc), in the expression of receptors and enzymes of the endocannabinoid and dopamine systems and in second messengers, such as Akt, in adult rats subjected to MS and early stress (MS + ES; 2 × 180 min daily) vs. nonseparated rats (NMS). Results showed that MS + ES induces higher D2R expression and lower D3R, FAAH, and MAGL expression compared with NMS rats. Alterations in total dendritic length were also detected and were characterized by increases in the NAcc while there were decreases in the FCx. We believe MS + ES‐induced changes in the dopaminergic and endocannabinergic systems and in the neuronal microstructure might be contributing to alcohol seeking behavior and, potential vulnerability to other drugs in rats. © 2015 Wiley Periodicals, Inc. Develop Neurobiol 76: 819–831, 2016 相似文献
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《Journal of biological education》2012,46(1):42-46
D. H. Jennings published in Journal of Biological Education, 14 (3), 223-230, which commented on the Association for Science Education's consultative document Alternatives for Science Education and the Royal Society discussion paper Science and the Organisation of Schools in England. 相似文献
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目的了解不同等级环境(屏障环境和普通环境)对实验大小鼠的一般生理表现和抗应激能力以及对药物反应的影响,初步判定严格的微生物控制是否影响实验动物的人类模型作用。方法将40只SPF级Wistar大鼠和200只SPF级BALB/c小鼠分别饲养于屏障环境和普通环境内,通过以下实验对比观察不同等级环境对实验大、小鼠及其应用的影响:每周测量动物的体重增长情况;饲养35d后,测定大鼠15项血液学指标、14项血液生化指标和9个脏器的相对重量;以抗缺氧实验和游泳实验判断对小鼠体质和抗应激能力的影响;以5.氟尿嘧啶急性毒性实验和戊巴比妥钠麻醉实验测试其对药物作用的异同。结果在5周观察期内,屏障环境饲养小鼠和大鼠的体重增长均明显快于普通环境的对照动物(P〈0.05);普通环境饲养大鼠的血液RBC、WBC、PCT、PLT、GOT、GGT、GPT、CK、TB值高于屏障环境大鼠(P〈0.05),而CHO、LDL-C和HDL-C值低于屏障环境大鼠(P〈0.05);不同微生物环境条件饲养小鼠的游泳耐力和抗缺氧实验结果接近,但是屏障环境组动物所获数据的变异较小;不同等级环境条件饲养小鼠的戊巴比妥钠麻醉反应和5-氟尿嘧啶中毒反应相似,而屏障环境组动物的麻醉维持时间较短,LD50较低,95%可信限狭窄。结论饲养于屏障环境和普通环境的实验大、小鼠在一般生理表现上出现部分差异,动物的抗应激能力和对药物的反应未发生显著变化;在屏障环境条件中,动物的药物反应更敏感、所获数据更稳定,因此,初步认为严格微生物控制条件下的SPF级动物可以作为生活在自然环境中的人类的模型动物。 相似文献
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Franklin E. Mirer Barry S. Levine Sheldon D. Murphy 《Chemico-biological interactions》1977,17(1):99-112
Pretreatment of male mice with piperonyl butoxide, 400 mg/kg 1 h before challenge with insecticides, resulted in a 40-fold antagonism of the acute i.p. toxicity of methyl parathion but potentiated the toxicity of parathion two-fold. Piperonyl butoxide had no effect on the toxicity of the oxygen analogs of these insecticides, methyl paraoxon and paraoxon. Diethyl maleate (1 ml/kg) depleted liver glutathione by 80% after one hour, potentiated the toxicity of both methyl parathion and methyl paraoxon, and partially counteracted the protective effect of piperonyl butoxide on methyl parathion toxicity. Piperonyl butoxide delayed the onset of brain cholinesterase inhibition by parathion. Studies of the metabolism of the insecticides by liver homogenates in vitro demonstrated that piperonyl butoxide inhibited both the oxidative formation of the oxygen analogs (activation) and oxidative cleavage to p-nitrophenol and dialkylphosphorothioic acid (detoxification). While parathion metabolism was mostly oxidative, methyl parathion metabolism appeared to be predominantly via glutathione-dependent enzymes. Studies of in vitro distribution of the insecticides demonstrated that piperonyl butoxide pretreatment resulted in elevated tissue concentrations of parathion and methyl parathion; however, the rate constant for elimination from plasma for both insecticides was unaffected by piperonyl butoxide. The overall rate of metabolism of methyl parathion in vivo was approximately twice that of parathion. These results suggest that during piperonyl butoxide inhibition of oxidative activation and cleavage, methyl parathion detoxification continues through uninhibited glutathione-dependent pathways of metabolism. The net result is a reduction in the acute toxicity of methyl parathion. Lack of an effective alternate pathway of detoxification may explain the delayed but greater toxicity of parathion in piperonyl butoxide pretreated mice. 相似文献