全文获取类型
收费全文 | 737篇 |
免费 | 85篇 |
国内免费 | 2篇 |
出版年
2023年 | 6篇 |
2022年 | 2篇 |
2021年 | 18篇 |
2020年 | 18篇 |
2019年 | 23篇 |
2018年 | 24篇 |
2017年 | 25篇 |
2016年 | 25篇 |
2015年 | 29篇 |
2014年 | 34篇 |
2013年 | 56篇 |
2012年 | 60篇 |
2011年 | 62篇 |
2010年 | 52篇 |
2009年 | 24篇 |
2008年 | 39篇 |
2007年 | 39篇 |
2006年 | 26篇 |
2005年 | 20篇 |
2004年 | 25篇 |
2003年 | 18篇 |
2002年 | 26篇 |
2001年 | 16篇 |
2000年 | 25篇 |
1999年 | 11篇 |
1998年 | 17篇 |
1997年 | 5篇 |
1996年 | 10篇 |
1995年 | 11篇 |
1994年 | 6篇 |
1993年 | 2篇 |
1992年 | 3篇 |
1991年 | 5篇 |
1990年 | 9篇 |
1989年 | 10篇 |
1988年 | 4篇 |
1987年 | 6篇 |
1986年 | 7篇 |
1985年 | 3篇 |
1984年 | 4篇 |
1983年 | 3篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1977年 | 3篇 |
1976年 | 1篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1969年 | 1篇 |
1968年 | 2篇 |
1967年 | 1篇 |
排序方式: 共有824条查询结果,搜索用时 171 毫秒
1.
Solans Mariana Vobis Gernot Cassán Fabricio Luna Virginia Wall Luis Gabriel 《World journal of microbiology & biotechnology》2011,27(9):2195-2202
The aim of the present study was to evaluate phytohormone production by symbiotic and saprophytic actinomycetes isolated from
the actinorhizal plant Ochetophila trinervis which had previously proved to stimulate nodulation by Frankia. Three saprophytic strains out of 122, isolated from the rhizosphere of this plant with multiple enzymatic activities were
selected for plant growth experiments in pots: Streptomyces sp. (BCRU-MM40), Actinoplanes sp. (BCRU-ME3) and Micromonospora sp. (BCRU-MM18). For experiments, the symbiotic N2-fixing strain Frankia (BCU110501), isolated from nodules of the same actinorhizal plant was used. Phytohormone production was evaluated in supernatant
of non-inoculated and inoculated culture media in exponential growth phase. Indole 3-acetic acid (IAA) and gibberellic acid
(GA3) were analyzed by gas chromatography-mass spectrometry (GC–MS), while zeatine (Z) production was determined by gas chromatography-flame
ionization detector and high performance liquid chromatography (HPLC fluorescent and UV). The levels of the three phytohormones
produced by the saprophytic rhizoactinomycetes were higher than that produced by the symbiotic Frankia strain. Zeatine biosynthesis was higher (μg ml−1) than IAA and GA3 (ng ml−1), and Micromonospora strain produced the highest levels of these phytohormones. Although O. trinervis has been shown to be intercellularly infected by Frankia without mediation of root hair deformation, when plants were co-inoculated with actinomycetes’ culture, some root hair deformation
was observed. This is the first report on identification of IAA, GA3 and Z in saprophytic actinomycetes and their potential role in plant–microbe interaction. 相似文献
2.
In the present note the author presents history of the discovery and of the status of the excavation of the site La Isabela,
the first settlement planned by Columbus in the New World during his second trip to America in the summer of 1493. 相似文献
3.
Bernadette Sánchez Kevin D. Pinkston Adina C. Cooper Carlos Luna Shelby T. Wyatt 《应用发育科学》2018,22(1):14-28
The aim of this study was to investigate the processes involved in developing close peer mentoring relationships among African American and Latino male adolescents in a school-based, group peer mentoring program. Qualitative one-on-one in-depth interviews were conducted with six school staff members, who administer the program, and 26 program participants about their experiences in the mentoring program. Data analysis revealed five program processes that led to close mentoring relationships: (a) rapport-building activities, (b) safe space, (c) mutual support, (d) group identity, and (e) trust. These processes ultimately led to bonding and friendship among program members, which further solidified the previous processes. Implications and future directions are discussed. 相似文献
4.
Sacramento Doralice Rodrigues Coelho Rosalie Reed Rodrigues Wigg Márcia Dutra Toledo Luna Linhares Luiz Fernando de Matos dos Santos Marta Gonçalves Azevedo Soares Semêdo Luzia Teixeira de Ribeiro da Silva Antonio Jorge 《World journal of microbiology & biotechnology》2004,20(3):225-229
A promising producer of bioactive compounds isolated from a Brazilian tropical soil was tested for its range of antimicrobial
activities. Strain 606, classified as Streptomyces sp., could not be identified up to species level, suggesting a possible new taxon. The supernatant and 10 extracts and fractions,
obtained by extraction and chromatographic techniques, presented antimicrobial activity using antibiograms. The methanolic
fraction was highly active against pathogenic bacteria, phytopathogenic fungi and the human pathogenic yeast Candida albicans. It also possessed high antiviral activity inhibiting the propagation of an acyclovir-resistant herpes simplex virus type
1 strain on HEp-2 cells at non-cytotoxic concentration. The strong cytotoxic effect suggests an antitumour action.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
5.
The interplay of riverscape features and exotic introgression on the genetic structure of the Mexican golden trout (Oncorhynchus chrysogaster), a simulation approach 下载免费PDF全文
6.
Johana A. Luna Coronell Khulan Sergelen Philipp Hofer István Gyurján Stefanie Brezina Peter Hettegger Gernot Leeb Karl Mach Andrea Gsur Andreas Weinhäusel 《基因组蛋白质组与生物信息学报(英文版)》2018,16(1):73-84
Characterization of the colon cancer immunome and its autoantibody signature from differentially-reactive antigens (DIRAGs) could provide insights into aberrant cellular mechanisms or enriched networks associated with diseases. The purpose of this study was to characterize the antibody profile of plasma samples from 32 colorectal cancer (CRC) patients and 32 controls using proteins isolated from 15,417 human cDNA expression clones on microarrays. 671 unique DIRAGs were identified and 632 were more highly reactive in CRC samples. Bioinformatics analyses reveal that compared to control samples, the immunoproteomic IgG profiling of CRC samples is mainly associated with cell death, survival, and proliferation pathways, especially proteins involved in EIF2 and mTOR signaling. Ribosomal proteins (e.g., RPL7, RPL22, and RPL27A) and CRC-related genes such as APC, AXIN1, E2F4, MSH2, PMS2, and TP53 were highly enriched. In addition, differential pathways were observed between the CRC and control samples. Furthermore, 103 DIRAGs were reported in the SEREX antigen database, demonstrating our ability to identify known and new reactive antigens. We also found an overlap of 7 antigens with 48 “CRC genes.” These data indicate that immunomics profiling on protein microarrays is able to reveal the complexity of immune responses in cancerous diseases and faithfully reflects the underlying pathology. 相似文献
7.
8.
9.
QTL detection experiments in livestock species commonly use the half-sib design. Each male is mated to a number of females, each female producing a limited number of progeny. Analysis consists of attempting to detect associations between phenotype and genotype measured on the progeny. When family sizes are limiting experimenters may wish to incorporate as much information as possible into a single analysis. However, combining information across sires is problematic because of incomplete linkage disequilibrium between the markers and the QTL in the population. This study describes formulæ for obtaining MLEs via the expectation maximization (EM) algorithm for use in a multiple-trait, multiple-family analysis. A model specifying a QTL with only two alleles, and a common within sire error variance is assumed. Compared to single-family analyses, power can be improved up to fourfold with multi-family analyses. The accuracy and precision of QTL location estimates are also substantially improved. With small family sizes, the multi-family, multi-trait analyses reduce substantially, but not totally remove, biases in QTL effect estimates. In situations where multiple QTL alleles are segregating the multi-family analysis will average out the effects of the different QTL alleles. 相似文献
10.
Fernanda Luna da Silva Eduardo Coelho Cerqueira Mônica Santos de Freitas Daniela Leão Gonçalves Lilian Terezinha Costa Cristian Follmer 《Neurochemistry international》2013
In the last decades, a series of compounds, including quinones and polyphenols, has been described as having anti-fibrillogenic action on α-synuclein (α-syn) whose aggregation is associated to the pathogenesis of Parkinson’s disease (PD). Most of these molecules act as promiscuous anti-amyloidogenic agents, interacting with the diverse amyloidogenic proteins (mostly unfolded) through non-specific hydrophobic interactions. Herein we investigated the effect of the vitamins K (phylloquinone, menaquinone and menadione), which are 1,4-naphthoquinone (1,4-NQ) derivatives, on α-syn aggregation, comparing them with other anti-fibrillogenic molecules such as quinones, polyphenols and lipophilic vitamins. Vitamins K delayed α-syn fibrillization in substoichiometric concentrations, leading to the formation of short, sheared fibrils and amorphous aggregates, which are less prone to produce leakage of synthetic vesicles. In seeding conditions, menadione and 1,4-NQ significantly inhibited fibrils elongation, which could be explained by their ability to destabilize preformed fibrils of α-syn. Bidimensional NMR experiments indicate that a specific site at the N-terminal α-syn (Gly31/Lys32) is involved in the interaction with vitamins K, which is corroborated by previous studies suggesting that Lys is a key residue in the interaction with quinones. Together, our data suggest that 1,4-NQ, recently showed up by our group as a potential scaffold for designing new monoamine oxidase inhibitors, is also capable to modulate α-syn fibrillization in vitro. 相似文献