全文获取类型
收费全文 | 1052篇 |
免费 | 72篇 |
国内免费 | 1篇 |
出版年
2023年 | 9篇 |
2022年 | 6篇 |
2021年 | 28篇 |
2020年 | 18篇 |
2019年 | 15篇 |
2018年 | 26篇 |
2017年 | 25篇 |
2016年 | 31篇 |
2015年 | 58篇 |
2014年 | 69篇 |
2013年 | 75篇 |
2012年 | 100篇 |
2011年 | 115篇 |
2010年 | 52篇 |
2009年 | 50篇 |
2008年 | 57篇 |
2007年 | 73篇 |
2006年 | 41篇 |
2005年 | 63篇 |
2004年 | 40篇 |
2003年 | 33篇 |
2002年 | 51篇 |
2001年 | 8篇 |
2000年 | 2篇 |
1999年 | 9篇 |
1998年 | 9篇 |
1997年 | 2篇 |
1996年 | 8篇 |
1995年 | 12篇 |
1994年 | 2篇 |
1993年 | 3篇 |
1992年 | 5篇 |
1991年 | 1篇 |
1990年 | 3篇 |
1989年 | 3篇 |
1988年 | 1篇 |
1987年 | 3篇 |
1986年 | 1篇 |
1984年 | 2篇 |
1983年 | 3篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1977年 | 1篇 |
1976年 | 2篇 |
1969年 | 1篇 |
1964年 | 1篇 |
1960年 | 1篇 |
1952年 | 1篇 |
排序方式: 共有1125条查询结果,搜索用时 234 毫秒
911.
Arun A. Gupta Ines Reinartz Gogulan Karunanithy Alessandro Spilotros Venkateswara Rao Jonna Anders Hofer Dmitri I. Svergun Andrew J. Baldwin Alexander Schug Magnus Wolf-Watz 《Journal of molecular biology》2018,430(18):3157-3169
Bacterial virulence is typically initiated by translocation of effector or toxic proteins across host cell membranes. A class of gram-negative pathogenic bacteria including Yersinia pseudotuberculosis and Yersinia pestis accomplishes this objective with a protein assembly called the type III secretion system. Yersinia effector proteins (Yop) are presented to the translocation apparatus through formation of specific complexes with their cognate chaperones (Syc). In the complexes where the structure is available, the Yops are extended and wrap around their cognate chaperone. This structural architecture enables secretion of the Yop from the bacterium in early stages of translocation. It has been shown previously that the chaperone-binding domain of YopE is disordered in its isolation but becomes substantially more ordered in its wrap-around complex with its chaperone SycE. Here, by means of NMR spectroscopy, small-angle X-ray scattering and molecular modeling, we demonstrate that while the free chaperone-binding domain of YopH (YopHCBD) adopts a fully ordered and globular fold, it populates an elongated, wrap-around conformation when it engages in a specific complex with its chaperone SycH2. Hence, in contrast to YopE that is unstructured in its free state, YopH transits from a globular free state to an elongated chaperone-bound state. We demonstrate that a sparsely populated YopHCBD state has an elevated affinity for SycH2 and represents an intermediate in the formation of the protein complex. Our results suggest that Yersinia has evolved a binding mechanism where SycH2 passively stimulates an elongated YopH conformation that is presented to the type III secretion system in a secretion-competent conformation. 相似文献
912.
Ines Swoboda Karin Hoffmann-Sommergruber Gabriel O'Ríordáin Otto Scheiner Erwin Heberle-Bors Oscar Vicente 《Physiologia plantarum》1996,96(3):433-438
The Bet v. 1 gene family of birch encodes the major pollen allergens as well as pathogenesis-related (PR) proteins that are induced by microbes in somatic tissues. These PR proteins belong to a group of conserved intracellular defense-related proteins that have been termed 'ribonuclease-like' PR proteins, on the basis of the partial sequence homology observed between PR1, a Bet v 1-homologue from parsley, and a recently characterized ginseng ribonuclease. However, this enzymatic activity has not yet been demonstrated, not for any of the members of this family of PR proteins, nor for the related pollen allergens. We have investigated the possible nuclease activity of Bet v 1 using apparently homogeneous preparations of natural Bet v 1 purified from birch pollen, and a recombinant non-fusion protein purified from E. coli extracts. We report here that Bet v 1 proteins indeed possess an intrinsic ribonucleolytic activity as they can digest different RNA substrates in vitro, but show no activity on single or double-stranded DNA. 相似文献
913.
Ines Jedidi Carlos Soldevilla Amani Lahouar Patricia Marín María Teresa González-Jaén Salem Said 《Saudi Journal of Biological Sciences》2018,25(5):868-874
Wheat, barley and maize are the mainly consumed cereals in Tunisia. This study aimed to determine the mycoflora of these cereals with special focus on the mycotoxigenic Aspergillus and Fusarium species. Freshly harvested samples and other stored samples of each type of cereal (31 and 34 samples, respectively) were collected in Tunisia and cultured for fungal isolation and identification. Identification of fungal genera was based on morphological features. Aspergillus and Fusarium species were identified by species specific PCR assays complemented with DNA sequencing. Alternaria (70.83%), Eurotium (62.50%), Aspergillus (54.17%) and Penicillium (41.67%) were the most frequent fungi isolated from wheat. Penicillium (75%), Aspergillus (70%), Eurotium (65%) and Alternaria (65%) were the most frequently recovered genera from barley. The predominant genera in maize were Aspergillus (76.19%), Eurotium (42.86%), and Penicillium (38.09%). Aspergilllus, Penicillium, Fusarium and Alternaria were detected in both stored and freshly harvested grain samples. The frequencies of contamination with Aspergillus, Fusarium and Alternaria were higher in freshly harvested samples, whereas Penicillium species were more frequent in stored samples. The predominant Aspergillus species detected were A. flavus and A. niger. The Fusarium species detected were F. equiseti, F. verticillioides, F. nygamai, and F. oxysporum. This study suggested the potential risk for Aflatoxins and, to a lesser extent, for Ochratoxin A in Tunisian cereals. This is the first survey about mycoflora associated with wheat, barley and maize in Tunisia. 相似文献
914.
915.
Identification by Inverse Virtual Screening of magnolol-based scaffold as new tankyrase-2 inhibitors
Simone Di Micco Luana Pulvirenti Ines Bruno Stefania Terracciano Alessandra Russo Maria C. Vaccaro Dafne Ruggiero Vera Muccilli Nunzio Cardullo Corrado Tringali Raffaele Riccio Giuseppe Bifulco 《Bioorganic & medicinal chemistry》2018,26(14):3953-3957
The natural product magnolol (1) and a selection of its bioinspired derivatives 2–5, were investigated by Inverse Virtual Screening in order to identify putative biological targets from a panel of 308 proteins involved in cancer processes. By this in silico analysis we selected tankyrase-2 (TNKS2), casein kinase 2 (CK2) and bromodomain 9 (Brd9) as potential targets for experimental evaluations. The Surface Plasmon Resonance assay revealed that 3–5 present a good affinity for tankyrase-2, and, in particular, 3 showed an antiproliferative activity on A549 cells higher than the well-known tankyrase-2 inhibitor XAV939 used as reference compound. 相似文献
916.
Daniel J. Mennill Stéphanie M. Doucet Amy E.M. Newman Heather Williams Ines G. Moran Ian P. Thomas Bradley K. Woodworth D. Ryan Norris 《Current biology : CB》2018,28(20):3273-3278.e4
917.
918.
24S-Hydroxycholesterol (24S-OH-Chol) and 27-hydroxycholesterol (27-OH-Chol) are oxidized derivatives of cholesterol and of potential diagnostic interest because their circulating levels may reflect the cholesterol metabolism of the brain and macrophages, respectively. We developed a sensitive and specific HPLC-MS method for the quantification of 24S-OH-Chol and 27-OH-Chol in human plasma. In contrast to currently available procedures based on gas chromatography-mass spectrometry, this methodology offers the advantage that no time-consuming derivatization is needed. After saponification, solid-phase extraction, and HPLC separation under reversed-phase column conditions, detection by MS was performed using atmospheric pressure chemical ionization and selected ion monitoring mode. The standard curves were linear throughout the calibration range for both oxysterols. Within-day and between-day coefficients of variation were less than 9%, and the recoveries ranged between 98% and 103%. The quantification limits were 40 and 25 microg/l for 24S-OH-Chol and 27-OH-Chol, respectively. Mean values for both oxysterols were determined in plasma from 22 healthy volunteers. The sensitive and selective HPLC-MS method described here combined with the appropriate workup procedure allow the quantification of 24S-OH-Chol and 27-OH-Chol in plasma samples, for example in clinical studies to elaborate the clinical usefulness of these two oxysterols. 相似文献
919.
920.
Aleksandar Lukić Sebastian Dochow Olga Chernavskaia Ines Latka Christian Matthäus Anka Schwuchow Michael Schmitt Jürgen Popp 《Journal of biophotonics》2016,9(1-2):138-143
Over the past years it had been demonstrated that multimodal imaging combining the nonlinear modalities coherent anti‐Stokes Raman scattering (CARS), two‐photon excited auto‐fluorescence (TPEF) and second harmonic generation (SHG) show a great potential for tissue diagnosis and tumor identification. To extend the applicability of this multimodal imaging approach for in‐vivo tissue screening of difficult to access body regions the development of suitable fiber optic probes is required. Here we report about a novel CARS imaging fiber probe consisting of 10,000 coherent light guiding elements preserving the spatial relationship between the entrance and the output of the fiber. Therefore the scanning procedure can be shifted from the distal to the proximal end of the fiber probe and no moving parts or driving current are required to realize in‐vivo CARS endoscopy.