全文获取类型
收费全文 | 12155篇 |
免费 | 1079篇 |
国内免费 | 6篇 |
出版年
2022年 | 64篇 |
2021年 | 149篇 |
2020年 | 91篇 |
2019年 | 118篇 |
2018年 | 161篇 |
2017年 | 124篇 |
2016年 | 235篇 |
2015年 | 400篇 |
2014年 | 437篇 |
2013年 | 548篇 |
2012年 | 732篇 |
2011年 | 716篇 |
2010年 | 505篇 |
2009年 | 443篇 |
2008年 | 702篇 |
2007年 | 656篇 |
2006年 | 639篇 |
2005年 | 692篇 |
2004年 | 673篇 |
2003年 | 651篇 |
2002年 | 657篇 |
2001年 | 115篇 |
2000年 | 91篇 |
1999年 | 149篇 |
1998年 | 194篇 |
1997年 | 124篇 |
1996年 | 128篇 |
1995年 | 125篇 |
1994年 | 123篇 |
1993年 | 111篇 |
1992年 | 100篇 |
1991年 | 89篇 |
1990年 | 95篇 |
1989年 | 85篇 |
1988年 | 88篇 |
1987年 | 88篇 |
1986年 | 82篇 |
1985年 | 114篇 |
1984年 | 141篇 |
1983年 | 113篇 |
1982年 | 135篇 |
1981年 | 143篇 |
1980年 | 147篇 |
1979年 | 82篇 |
1978年 | 92篇 |
1977年 | 85篇 |
1976年 | 70篇 |
1975年 | 73篇 |
1974年 | 93篇 |
1973年 | 83篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
981.
982.
Daniel Landgrebe Claas Haake Tim Höpfner Sascha Beutel Bernd Hitzmann Thomas Scheper Martin Rhiel Kenneth F. Reardon 《Applied microbiology and biotechnology》2010,88(1):11-22
One of the major aims of bioprocess engineering is the real-time monitoring of important process variables. This is the basis
of precise process control and is essential for high productivity as well as the exact documentation of the overall production
process. Infrared spectroscopy is a powerful analytical technique to analyze a wide variety of organic compounds. Thus, infrared
sensors are ideal instruments for bioprocess monitoring. The sensors are non-invasive, have no time delay due to sensor response
times, and have no influence on the bioprocess itself. No sampling is necessary, and several components can be analyzed simultaneously.
In general, the direct monitoring of substrates, products, metabolites, as well as the biomass itself is possible. In this
review article, insights are provided into the different applications of infrared spectroscopy for bioprocess monitoring and
the complex data interpretation. Different analytical techniques are presented as well as example applications in different
areas. 相似文献
983.
984.
Ferland-McCollough D Ozanne SE Siddle K Willis AE Bushell M 《Biochemical Society transactions》2010,38(6):1565-1570
T2D (Type 2 diabetes mellitus) is a major health issue that has reached epidemic status worldwide. T2D is a progressive metabolic disorder characterized by reduced insulin sensitivity, insulin resistance and pancreatic β-cell dysfunction. Improper treatment of TD2 can lead to severe complications such as heart disease, stroke, kidney failure, blindness and nerve damage. The aetiology and molecular mechanisms of T2D are not fully understood, but compelling evidence points to a link between T2D, obesity, dyslipidaemia and insulin resistance. Although T2D seems to be strongly linked to environmental factors such as nutrition and lifestyle, studies have shown that genetic factors, such as polymorphisms associated with metabolic genes, imprinting, fetal programming and miRNA (microRNA) expression, could also contribute to the development of this disease. miRNAs are small 22-25-nt-long untranslated RNAs that negatively regulate the translation of mRNAs. miRNAs are involved in a large number of biological functions such as development, metabolism, immunity and diseases such as cancer, cardiovascular diseases and diabetes. The present review examines the various miRNAs that have been identified as being potentially involved in T2D, focusing on the insulin-sensitive organs: white adipose tissue, liver, skeletal muscle and the insulin-producing pancreatic β-cells. 相似文献
985.
986.
John Yeuk-Hon Chan Li Li Ji Miao Dong-Qing Cai Kenneth Ka-Ho Lee Yiu-Loon Chui 《Molecular biology reports》2010,37(1):363-368
Stress-responsive genes play critical roles in many biological functions that includes apoptosis, survival, differentiation
and regeneration. We have identified a novel stress-responsive gene called BRE which interacts with TNF-receptor-1 and blocks the apoptotic effect of TNF-α. BRE enhances tumor growth in vivo and is up-regulated in hepatocellular and esophageal carcinomas. BRE also regulates the ubiquitination of the DNA repair complex BRCC, and the synthesis of steroid hormones. Here, we examined
BRE-mRNA in cells after treatments with UV and ionizing radiation (IR). UV and IR treatment alone suppressed BRE-mRNA levels by more than 90% at 24 h, while hydroxyurea, fluorodeoxyuridine, aphidicolin, known inhibitors of S-phase DNA
synthesis, had no significant effect. BRE protein expression was unaltered in cells treated with TNF-α, Interleukin-1 and Dexamethasone, while a threefold increase
was observed following chorionic gonadotropin exposure. Although BRE plays a regulatory role in many different pathways, yet its expression is apparently under very stringent control. 相似文献
987.
988.
989.
Christian K. Tipsmark Kenneth J. Sørensen Katrine Hulgard Steffen S. Madsen 《Comparative biochemistry and physiology. Part A, Molecular & integrative physiology》2010,155(3):361-370
In seawater fishes, osmotic homeostasis requires uptake of ions and water in the intestine and these processes are governed by the combined trans- and paracellular pathways. The current study examined mRNA expression of two tight junction proteins (claudin-15 and -25b) predominantly expressed in the intestine of Atlantic salmon. We examined the response in pyloric caecae, middle and posterior intestine to seawater challenge, during smoltification and after injection with osmoregulatory hormones. Seawater (SW) transfer elevated levels of claudin-15 and -25b while no change was induced throughout the smolt stage. In freshwater, cortisol and growth hormone inhibited claudin-15 expression in the two anterior segments. Claudin-25b was elevated in all intestinal segments by growth hormone, while cortisol had an inhibitory effect. In seawater, prolactin and cortisol inhibited claudin expression. The data suggest that claudin expression is involved in the reorganisation of intestinal epithelium and possibly change paracellular permeability during SW acclimation. The lack of preparatory change during smoltification suggests that this process is not completed during smolt development. The effects of the tested hormones cannot explain the sum of changes induced by salinity, which, like the smoltification data, suggests the importance of additional factors and possibly contact with the imbibed SW per se. 相似文献
990.
Mélanie Drolet Marc Brisson Kenneth E. Schmader Myron J. Levin Robert Johnson Michael N. Oxman David Patrick Caty Blanchette James A. Mansi 《CMAJ》2010,182(16):1731-1736