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排序方式: 共有106条查询结果,搜索用时 11 毫秒
11.
Bioclimate envelope models are often used to predict changes in species distribution arising from changes in climate. These models are typically based on observed correlations between current species distribution and climate data. One limitation of this basic approach is that the relationship modelled is assumed to be constant in space; the analysis is global with the relationship assumed to be spatially stationary. Here, it is shown that by using a local regression analysis, which allows the relationship under study to vary in space, rather than conventional global regression analysis it is possible to increase the accuracy of bioclimate envelope modelling. This is demonstrated for the distribution of Spotted Meddick in Great Britain using data relating to three time periods, including predictions for the 2080s based on two climate change scenarios. Species distribution and climate data were available for two of the time periods studied and this allowed comparison of bioclimate envelope model outputs derived using the local and global regression analyses. For both time periods, the area under the receiver operating characteristics curve derived from the analysis based on local statistics was significantly higher than that from the conventional global analysis; the curve comparisons were also undertaken with an approach that recognised the dependent nature of the data sets compared. Marked differences in the future distribution of the species predicted from the local and global based analyses were evident and highlight a need for further consideration of local issues in modelling ecological variables. 相似文献
12.
Tatiane Katsue Furuya Patrícia Natália Oliveira da Silva Spencer Luiz Marques Payão Lucas Trevizani Rasmussen Roger Willian de Labio Paulo Henrique Ferreira Bertolucci Ianna Lacerda Sampaio Braga Elizabeth Suchi Chen Gustavo Turecki Naguib Mechawar Jonathan Mill Marília de Arruda Cardoso Smith 《Neurochemistry international》2012
Alzheimer’s Disease (AD) is a neurodegenerative disorder and the most common cause of dementia among the elderly. Efforts have been made to understand the genetic and epigenetic mechanisms involved in the development of this disease. As SORL1 (sortilin-related receptor) and SIRT1 (sirtuin 1) genes have been linked to AD pathogenesis, we aimed to investigate their mRNA expression and promoter DNA methylation in post mortem brain tissues (entorhinal and auditory cortices and hippocampus) from healthy elderly subjects and AD patients. We also evaluated these levels in peripheral blood leukocytes from young, healthy elderly and AD patients, investigating whether there was an effect of age on these profiles. The comparative CT method by Real Time PCR and MALDI-TOF mass spectrometry were used to analyze gene expression and DNA methylation, respectively. SORL1 gene was differently expressed in the peripheral blood leukocytes and might act as a marker of aging in this tissue. Furthermore, we found that SORL1 promoter DNA methylation might act as one of the mechanisms responsible for the differences in expression observed between blood and brain for both healthy elderly and AD patients groups. The impact of these studied genes on AD pathogenesis remains to be better clarified. 相似文献
13.
目的:探讨老年髋关节置换术后发生早期脱位的相关因素。方法:选取在我院行髋关节置换术治疗的老年患者110例,随访3个月,并对置换术后可能导致早期脱位的7个因素进行单因素和多因素Logistic回归分析。结果:单因素分析发现,性别、年龄、手术方式、人工股骨头直径大小这4个因素在有脱位组和无脱位组间的差异有统计学意义(P0.05)。多因素Logistic回归分析显示,导致早期脱位的3个危险因素分别是年龄(X2=16.572,P=0.000)、手术方式(X2=5.283,P=0.021)、人工股骨头直径大小(X2=5.498,P=0.019)。结论:老年髋关节置换术后早期脱位的发生可能受多个因素的影响,术前及术中应充分考虑各危险因素,从而选择最佳治疗方案。 相似文献
14.
《Bioorganic & medicinal chemistry》2019,27(24):115157
N-Methylpyrrolidone is a solvent molecule which has been shown to compete with acetyl-lysine-containing peptides for binding to bromodomains. From crystallographic studies, it has also been shown to closely mimic the acetamide binding motif in several bromodomains, but has not yet been directly pursued as a fragment in bromodomain inhibition. In this paper, we report the elaboration of N-methylpyrrolidone as a potential lead in fragment-based drug design. Firstly, N-methylpyrrolidone was functionalised to provide points for chemical elaboration. Then, the moiety was incorporated into analogues of the reported bromodomain inhibitor, Olinone. X-ray crystallography revealed that the modified analogues showed comparable binding affinity and structural mimicry to Olinone in the bromodomain binding site. 相似文献
15.
Disrupted-in-schizophrenia 1 (DISC1) is a multifunctional scaffold protein which plays an important role in neurogenesis and neural development in the adult brain, especially in the dentate gyrus (DG) of the hippocampus. Accumulated research has unveiled the role of DISC1 in several aspects of neural development and neurogenesis, such as neuronal maturation, proliferation, migration, positioning, differentiation, dendritic growth, axonal outgrowth, and synaptic plasticity. Studies on the function of this protein have explored multiple facets, including variants and missense mutants in genetics, proteins interactivity and signaling pathways in molecular biology, and pathogenesis and treatment targets of major mental illness, and more. In this review, we present several signaling pathways discussed in recent research, such as the AKT signaling pathway, GABA signaling pathway, GSK3β signaling pathway, Wnt signaling pathway, and NMDA-R signaling pathway. DISC1 interacts, directly or indirectly, with these signaling pathways and they co-regulate the process of adult neurogenesis in the hippocampus. 相似文献
16.
目的:了解巴中地区上消化道出血反复发作的原因,为治疗提供临床循证医学证据。方法:通过对2011年4月~2012年11月巴中地区1134例上消化道出血中132例反复发作的患者进行调查统计,分析这上消化道出血反复发作的132例患者的年龄、生理特征、生活饮食习惯、精神状态、生活压力等多种相关因素。结果:发现饮食不当、精神紧张、腹腔感染、腹腔内压增高、输液输血过速、过量等是造成病情反复发作的主要诱因。结论:通过消除疾病的诱发因素,认真做好健康教育指导,积极治疗原发病是预防反复发作的有效措施。 相似文献
17.
王松林白雪赵延欣黄敬陈玉娟刘学源 《现代生物医学进展》2012,12(26):5154-5159
目的:探讨急性脑梗死患者血浆同型半胱氨酸水平及相关因素。方法:采用高效液相色谱法检测232例急性脑梗死患者血浆Hcy水平,并对其相关因素进行统计学分析。结果:急性脑梗死组患者血浆Hcy水平明显升高(P<0.05);并与叶酸及维生素B12水平显著相关。不同年龄段急性脑梗死患者血浆Hcy水平具有差异。并与颈动脉粥样硬化斑块相关联。结论:血浆Hcy水平增高是脑梗死的危险因素之一,并与患者年龄、血液中叶酸、维生素B12水平及脑梗死性质相关联。 相似文献
18.
目的:分析特定人群超重患病率,以及超重与高血压、糖尿病、血脂异常、脂肪肝等相关疾病的关系,为及早预防慢性非传染性疾病奠定基础。方法:对平房地区采取长效避孕措施的603名户籍农村已婚育龄妇女进行健康体检,按体重指数(BMI)分为正常组、超重组和肥胖组,比较各组间高血压、高血糖、高血脂、脂肪肝等相关疾病检出率的差异。结果:特定人群超重发病率及超重相关疾病检出率的差异均具有统计学意义(P〈0.01)。结论:平房地区特定人群超重及肥胖发病率未明显高于国内平均水平及全市水平。但超重及肥胖与高血压、糖尿病、血脂异常、脂肪肝等疾病存在较大相关关系,为了进一步降低心脑血管高危因素和死亡率。需采取早期、有效的措施控制超重和肥胖倾向。 相似文献
19.
Cheng Q Taguchi K Aleksunes LM Manautou JE Cherrington NJ Yamamoto M Slitt AL 《Journal of biochemical and molecular toxicology》2011,25(5):320-329
Chemicals that activate nuclear factor-E2-related factor 2 (Nrf2) often increase multidrug-resistance-associated protein (Mrp) expression in liver. Hepatocyte-specific deletion of Kelch-like ECH-associated protein 1 (Keap1) activates Nrf2. Use of hepatocyte-specific Keap1 deletion represents a nonpharmacological method to determine whether constitutive Nrf2 activation upregulates liver transporter expression in vivo. The mRNA, protein expression, and localization of several biotransformation and transporters were determined in livers of wild-type and hepatocyte-specific Keap1-null mice. Sulfotransferase 2a1/2, NADP(H):quinone oxidoreductase 1, cytochrome P450 2b10, 3a11, and glutamate-cysteine ligase catalytic subunit expression were increased in livers of Keap1-null mice. Organic anion-transporting polypeptide 1a1 expression was nearly abolished, as compared to that detected in livers of wild-type mice. By contrast, Mrp 1-5 mRNA and protein levels were increased in Keap1-null mouse livers, with Mrp4 expression being more than 15-fold higher than wild types. In summary, Nrf2 has a significant role in affecting Oatp and Mrp expressions. 相似文献
20.
近年来研究认为在创伤失血性休克的发生发展及液体复苏、缺血再关注过程中均伴随着炎症因子的变化,现将与炎症因子密切相关基因环氧化酶-2(COX-2)、核因子κB(NF-κB)、诱导型一氧化氮合酶(iNOS)、高迁移率族蛋白1(HMGB1)、低氧诱导因子1α(HIF1α)、血红素氧合酶-1(HO-1)、寒冷诱导的RNA结合蛋白(CIRBP)在创伤失血性休克中的作用机制方面的研究及进展作一综述,为创伤失血性休克临床救治提供思路。 相似文献