全文获取类型
收费全文 | 1297篇 |
免费 | 59篇 |
专业分类
1356篇 |
出版年
2023年 | 8篇 |
2022年 | 12篇 |
2021年 | 33篇 |
2020年 | 18篇 |
2019年 | 18篇 |
2018年 | 43篇 |
2017年 | 20篇 |
2016年 | 37篇 |
2015年 | 47篇 |
2014年 | 57篇 |
2013年 | 81篇 |
2012年 | 96篇 |
2011年 | 100篇 |
2010年 | 59篇 |
2009年 | 48篇 |
2008年 | 68篇 |
2007年 | 69篇 |
2006年 | 55篇 |
2005年 | 44篇 |
2004年 | 50篇 |
2003年 | 50篇 |
2002年 | 43篇 |
2001年 | 36篇 |
2000年 | 22篇 |
1999年 | 22篇 |
1998年 | 9篇 |
1997年 | 5篇 |
1996年 | 7篇 |
1995年 | 7篇 |
1994年 | 7篇 |
1993年 | 13篇 |
1992年 | 14篇 |
1991年 | 6篇 |
1990年 | 8篇 |
1989年 | 7篇 |
1988年 | 15篇 |
1987年 | 10篇 |
1986年 | 9篇 |
1985年 | 14篇 |
1984年 | 9篇 |
1982年 | 9篇 |
1981年 | 6篇 |
1980年 | 10篇 |
1979年 | 10篇 |
1978年 | 4篇 |
1976年 | 5篇 |
1973年 | 4篇 |
1972年 | 7篇 |
1970年 | 6篇 |
1969年 | 6篇 |
排序方式: 共有1356条查询结果,搜索用时 15 毫秒
101.
Harsha L. Rao Viquar U. Begum Deepa Khadka Anil K. Mandal Sirisha Senthil Chandra S. Garudadri 《PloS one》2015,10(5)
PurposeTo compare the rate of mean deviation (MD) change on 24-2 versus 10-2 VFs in treated glaucomatous eyes with 5 or more examinations.MethodsIn a retrospective study, 24-2 and 10-2 VFs of 131 glaucoma patients (167 eyes) who had undergone at least 5 VFs examinations during their follow-up were analyzed. All these patients had VF defects both on 24-2 and 10-2 VFs. Rates of MD change were calculated using best linear unbiased predictions (BLUP).ResultsMedian age, MD on 24-2 VF at baseline, number of VFs performed during follow-up and follow-up duration were 55 years, -16.9 dB, 9 and 9 years respectively. Median rate of MD change was significantly greater (p<0.001) on 10-2 VF (-0.26 dB/year; interquartile range [IQR]: -0.47, -0.11) compared to 24-2 VFs (-0.19 dB/year; IQR: -0.41, -0.03). Comparing the rates of MD change in eyes with different severities of VF loss (early [MD better than -6 dB], moderate [-6 dB to -12 dB], advanced [-12 to -20 dB] and severe [MD worse than -20 dB]) at baseline (based on the MD on 24-2 VF), median rate of MD change was comparable between 10-2 and 24-2 VFs in mild (-0.45 dB/year vs. -0.40 dB/year, P = 0.42) and moderate (-0.32 dB/year vs. -0.40 dB/year, P = 0.26) VF loss categories, while the same were significantly greater on 10-2 VFs in advanced (-0.28 dB/year vs. -0.21 dB/year, P = 0.04) and severe (-0.18 dB/year vs. -0.06 dB/year, P<0.001) VF loss categories.ConclusionsIn patients with VF defects both on 24-2 and 10-2 VFs, evaluating the rate of MD change on 10-2 VFs may help in better estimation of glaucoma progression, especially so in eyes with advanced glaucoma at baseline. 相似文献
102.
Saptarshi Roy G. Aditya Kumar Md. Jafurulla Chitra Mandal Amitabha Chattopadhyay 《生物化学与生物物理学报:生物膜》2014
Visceral leishmaniasis is a vector-borne disease caused by an obligate intracellular protozoan parasite Leishmania donovani. The molecular mechanism involved in internalization of Leishmania is poorly understood. The entry of Leishmania involves interaction with the plasma membrane of host cells. We have previously demonstrated the requirement of host membrane cholesterol in the binding and internalization of L. donovani into macrophages. In the present work, we explored the role of the host actin cytoskeleton in leishmanial infection. We observed a dose-dependent reduction in the attachment of Leishmania promastigotes to host macrophages upon destabilization of the actin cytoskeleton by cytochalasin D. This is accompanied by a concomitant reduction in the intracellular amastigote load. We utilized a recently developed high resolution microscopy-based method to quantitate cellular F-actin content upon treatment with cytochalasin D. A striking feature of our results is that binding of Leishmania promastigotes and intracellular amastigote load show close correlation with cellular F-actin level. Importantly, the binding of Escherichia coli remained invariant upon actin destabilization of host cells, thereby implying specific involvement of the actin cytoskeleton in Leishmania infection. To the best of our knowledge, these novel results constitute the first comprehensive demonstration on the specific role of the host actin cytoskeleton in Leishmania infection. Our results could be significant in developing future therapeutic strategies to tackle leishmaniasis. 相似文献
103.
Ramansu Goswami Sudipto Mandal Sandip Mandal Pratap Kumar Padhy Santanu Ray Shibnath Mazumder 《Biologia》2014,69(7):825-833
Aeromonas hydrophila is frequently reported from arsenic affected areas. Present study was aimed to determine the effect of arsenic and temperature on growth of A. hydrophila. The bacteria were isolated from naturally infected fish from a water body in Birbhum, West-Bengal, India, which is reported to be an arsenic-free area. Arsenic concentration in natural aquatic reservoirs (e.g., pond, lake or river) varies from 0–6 mg/L. No significant change in bacterial growth was observed within this range of arsenic exposure. However, variation in temperature impacted the growth of A. hydrophila. A single dimension model was constructed using simple logistic equation. Rate parameters of the model were derived from the experimental observations. Comparison of model results and laboratory observations gives a good conformity regarding the effect of variation of arsenic concentration and temperature change on growth of this bacterium. From the analysis of this model we further get the idea that the maximum growth of A. hydrophila is supposed to be at 31.4°C in absence of arsenic, whereas at 477 mg/L arsenic concentration, the growth of the bacteria totally stops at 30°C. 相似文献
104.
105.
106.
Inocula were collected from four different sources such as Jajmau tannery waste treatment plant (ITW), Jajmau municipal waste treatment (IMW), Unnao distillery (IDW) and a batch reactor, in which the sludge of a field scale biogas reactor was added to cow dung slurry to develop inoculum (IBS). A combination of these mixed inocula were used for biogas production at 35°C in laboratory scale reactor (10 L capacity) and the average yield of biogas (0.547 Lg?1 volatile solid (VS)) and methane (0.323 Lg?1VS) in 41 d was higher in case of mixed inoculum IMW 1 (IMW+IBS), with maximum methane content in biogas (68% during 27–30 d), as compared to other mixed inocula as well as control i.e. ITW 1 (ITW+IBS), IDW1 (IDW+IBS) and IBS. The corresponding yields of gas were biogas (0.505, 0.536 and 0.456 Lg?1VS), methane (0.288, 0.305, and 0.245 Lg?1VS) where as, the corresponding maximum methane content in biogas was 62% during 29–33d, 64% during 29–33 d and 62% during 27–29 d in ITW1, IDW1 and IBS. 相似文献
107.
Downy mildew (Peronospora plantaginis) caused two different types of infection in the floral parts of isabgol (Plantago ovata). Systemic infection resulted in long spikes bearing weak and sterile florets, which later turned black due to saprophytic
growth. Localised infection produced various symptoms ranging between normal flower opening and failure to bloom. Different
parts of infected flowers such as sepal, petal, filament and anther were reduced in size compared to healthy flowers. However,
gynoecium was elongated in localised infection. P. plantaginis induced gradual sterility of isabgol flowers. Androecium was affected more than the gynoecium was. Pollen number, pollen
viability and germination reduced drastically due to localised infection. On the contrary, there were no significant differences
between healthy and locally infected flowers in terms of stigma receptivity. In systemically infected spikes, bud development
was arrested leading to sterility. When localised disease severity was high, secondary systemic infection caused similar symptoms.
Microscopic observations showed presence of the pathogen in different parts of the flowers. Downy mildew adversely affected
seed yield and quality; producing seeds, which were smaller and lighter than the healthy ones and later, became black. Seed
yield was reduced by as much as 73.45 percent. Husk content per unit seed mass increased relatively as the total surface area
of infected seeds increased. 相似文献
108.
Yan-Feng Li Wei He Young-Hwan Kim Arabinda Mandal Laura Digilio Ken Klotz Charles J Flickinger John C Herr 《Reproductive biology and endocrinology : RB&E》2010,8(1):101
Background
CABYR is a polymorphic calcium-binding protein of the sperm fibrous sheath (FS) which gene contains two coding regions (CR-A and CR-B) and is tyrosine as well as serine/threonine phosphorylated during in vitro sperm capacitation. Thus far, the detailed information on CABYR protein expression in mouse spermatogenesis is lacking. Moreover, because of the complexity of this polymorphic protein, there are no data on how CABYR isoforms associate and assemble into the FS. 相似文献109.
Athanasios Didangelos Xiaoke Yin Kaushik Mandal Mark Baumert Marjan Jahangiri Manuel Mayr 《Molecular & cellular proteomics : MCP》2010,9(9):2048-2062
The vascular extracellular matrix (ECM) is essential for the structural integrity of the vessel wall and also serves as a substrate for the binding and retention of secreted products of vascular cells as well as molecules coming from the circulation. Although proteomics has been previously applied to vascular tissues, few studies have specifically targeted the vascular ECM and its associated proteins. Thus, its detailed composition remains to be characterized. In this study, we describe a methodology for the extraction of extracellular proteins from human aortas and their identification by proteomics. The approach is based on (a) effective decellularization to enrich for scarce extracellular proteins, (b) successful solubilization and deglycosylation of ECM proteins, and (c) relative estimation of protein abundance using spectral counting. Our three-step extraction approach resulted in the identification of 103 extracellular proteins of which one-third have never been reported in the proteomics literature of vascular tissues. In particular, three glycoproteins (podocan, sclerostin, and agrin) were identified for the first time in human aortas at the protein level. We also identified extracellular adipocyte enhancer-binding protein 1, the cartilage glycoprotein asporin, and a previously hypothetical protein, retinal pigment epithelium (RPE) spondin. Moreover, our methodology allowed us to screen for proteolysis in the aortic samples based on the identification of proteolytic enzymes and their corresponding degradation products. For instance, we were able to detect matrix metalloproteinase-9 by mass spectrometry and relate its presence to degradation of fibronectin in a clinical specimen. We expect this proteomics methodology to further our understanding of the composition of the vascular extracellular environment, shed light on ECM remodeling and degradation, and provide insights into important pathological processes, such as plaque rupture, aneurysm formation, and restenosis.Vascular cells, in particular vascular smooth muscle cells, produce and maintain a complex meshwork of ECM.1 The ECM is not only the scaffold for the anchorage and mobility of residing cells but also absorbs and transduces the shear and strain forces of the blood flow. It is primarily composed of elastin, collagen, proteoglycans, and glycoproteins. The elastin fibers and type I and III fibrillar collagens form a rigid network of highly cross-linked interstitial matrix. They offer elasticity (elastin) and tensile strength (collagens). Proteoglycans, because of their negative charge, attract water and confer resistance to compression. Finally, glycoproteins participate in matrix organization and are essential for cell attachment.The vascular ECM also serves as a substrate for the binding and retention of secreted, soluble proteins of vascular cells as well as molecules coming from the circulation, including lipoproteins, growth factors, cytokines, proteases, and protease inhibitors. These components are invariably associated with ECM proteins, especially proteoglycans. Together they comprise the vascular extracellular environment and are pivotal for disease processes, such as atherosclerosis and aneurysm formation (1).Although proteomics has been previously applied to vascular tissues, only one study has specifically targeted the extracellular vascular environment (2). This study was focused on the isolation of intimal proteoglycans from human carotid arteries. Moreover, most proteomics studies use whole tissue lysates, which are rich in cellular proteins that inevitably mask the identification of the less abundant proteins of the vascular extracellular environment (3–5). Thus, the composition of the vascular ECM and its associated proteins remains poorly defined. In the present study, we used morphologically normal human aortic samples to develop a method for the extraction of proteins present in the extracellular environment, including ECM proteins and proteins attached to the ECM. We had three specific aims: first, to reduce the contamination with cellular proteins, thereby increasing the chance of identifying scarce extracellular proteins; second, to efficiently solubilize and deglycosylate ECM proteins to improve their analysis by liquid chromatography tandem mass spectrometry (LC-MS/MS); and third, to interface the nanoflow LC system to a recently developed injection device, which splits the flow from the analytical column, to allow the reanalysis of the same sample during a single LC-MS/MS run (RePlay, Advion).Our methodology provides a detailed overview of the aortic ECM and its associated proteins, many reported for the first time in proteomics analysis of the vasculature. Most importantly, this method could be adapted for use with other tissues to further our understanding of the composition of extracellular environment and ECM turnover under various disease conditions. 相似文献
110.
Katherine E. Smith Gary Fooks Jeff Collin Heide Weishaar Sema Mandal Anna B. Gilmore 《PLoS medicine》2010,7(1)