全文获取类型
收费全文 | 706篇 |
免费 | 42篇 |
国内免费 | 2篇 |
专业分类
750篇 |
出版年
2024年 | 5篇 |
2023年 | 10篇 |
2022年 | 21篇 |
2021年 | 20篇 |
2020年 | 16篇 |
2019年 | 21篇 |
2018年 | 24篇 |
2017年 | 19篇 |
2016年 | 25篇 |
2015年 | 35篇 |
2014年 | 42篇 |
2013年 | 49篇 |
2012年 | 38篇 |
2011年 | 36篇 |
2010年 | 32篇 |
2009年 | 27篇 |
2008年 | 22篇 |
2007年 | 27篇 |
2006年 | 26篇 |
2005年 | 35篇 |
2004年 | 22篇 |
2003年 | 22篇 |
2002年 | 21篇 |
2001年 | 7篇 |
2000年 | 4篇 |
1999年 | 12篇 |
1998年 | 3篇 |
1996年 | 3篇 |
1993年 | 3篇 |
1992年 | 4篇 |
1991年 | 8篇 |
1990年 | 6篇 |
1989年 | 16篇 |
1988年 | 6篇 |
1987年 | 4篇 |
1986年 | 6篇 |
1984年 | 6篇 |
1983年 | 3篇 |
1982年 | 4篇 |
1981年 | 5篇 |
1980年 | 4篇 |
1979年 | 6篇 |
1978年 | 6篇 |
1975年 | 2篇 |
1974年 | 6篇 |
1973年 | 4篇 |
1972年 | 3篇 |
1971年 | 3篇 |
1965年 | 4篇 |
1964年 | 5篇 |
排序方式: 共有750条查询结果,搜索用时 0 毫秒
101.
102.
J. Falk-Vairant P. Corrèges L. Eder-Colli N. Salem F. M. Meunier B. Lesbats F. Loctin †M. Synguelakis M. Israël Y. Dunant 《Journal of neurochemistry》1996,66(3):1322-1325
Abstract: Transmitter release was elicited in two ways from cultured cells filled with acetylcholine: (a) in a biochemical assay by successive addition of a calcium ionophore and calcium and (b) electrophysiologically, by electrical stimulation of individual cells and real-time recording with an embryonic Xenopus myocyte. Glioma C6-Bu-1 cells were found to be competent for Ca2+ -dependent and quantal release. In contrast, no release could be elicited from mouse neuroblastoma N18TG-2 cells. However, acetylcholine release could be restored when N18TG-2 cells were transfected with a plasmid coding for mediatophore. Mediatophore is a protein of nerve terminal membranes purified from the Torpedo electric organ on the basis of its acetylcholine-releasing capacity. The transfected N18TG-2 cells expressed Torpedo mediatophore in their plasma membrane. In response to an electrical stimulus, they generated in the myocyte evoked currents that were curare sensitive and calcium dependent and displayed discrete amplitude levels, like in naturally occurring synapses. 相似文献
103.
Detection and genotyping of group A rotaviruses isolated from sewage samples in Monastir,Tunisia between April 2007 and April 2010 下载免费PDF全文
104.
Adoptive transfer of autologous tumor-reactive T cells holds promise as a cancer immunotherapy. In this approach, T cells
are harvested from a tumor-bearing host, expanded in vitro and infused back to the same host. Conditioning of the recipient
host with a lymphodepletion regimen of chemotherapy or radiotherapy before adoptive T cell transfer has been shown to substantially
improve survival and anti-tumor responses of the transferred cells. These effects are further enhanced when the adoptive T
cell transfer is followed by vaccination with tumor antigens in combination with a potent immune adjuvant. Although significant
progress has been made toward an understanding of the reasons underlying the beneficial effects of lymphodepletion to T cell
adoptive therapy, the precise mechanisms remain poorly understood. Recent studies, including ours, would indicate a more central
role for antigen presenting cells, in particular dendritic cells. Unraveling the exact role of these important cells in mediation
of the beneficial effects of lymphodepletion could provide novel pathways toward the rational design of more effective anti-cancer
immunotherapy. This article focuses on how the frequency, phenotype, and functions of dendritic cells are altered during the
lymphopenic and recovery phases post-induction of lymphodepletion, and how they affect the anti-tumor responses of adoptively
transferred T cells. 相似文献
105.
Integral membrane proteins (IMPs) are popular target for drugs, but their resolved structures have been overlooked when compared with cytosolic proteins. The main reason is that IMPs usually need intensive post-translational modifications and they are bound to membranes, which increase the complexity of purifying or crystalizing them. Although different expression systems are used to express IMPs, baculovirus is considered one of the most successful expression systems for those proteins. Despite that, there are always unknown discrepancies in the level of IMPs expression in the baculovirus expression system. Retrospective studies have shown that expression of an immunoglobulin (anti-Chymase mouse monoclonal IgG1) driven by vp39 promoter was more efficient compared to its expression under polyhedrin (polh) promoter; however, this conclusion was not tested on different IMPs to generalize such a conclusion. In this study, the expression of eight different IMPs has been compared under vp39 and polh promoters of Autographa californica nucleopolyhedrovirus. Although different IMPs have shown different patterns of expression, the expression driven by vp39 promoter was found to be generally more efficient than the polh promoter. 相似文献
106.
Najla Al Shaye Hussein Migdadi Asma Charbaji Shatha Alsayegh Shaza Daoud Wala AL-Anazi Salem Alghamdi 《Saudi Journal of Biological Sciences》2018,25(6):1007-1015
Genetic diversity among seven Saudi tomato landraces collected from different regions of the country was assessed using SDS-PAGE and molecular (sequence-related amplified polymorphism- SRAP) markers. A total of 19 alternative protein bands with different mobility rates were identified within a molecular weight range of 9.584–225?KDa, with 53% polymorphism. Specific protein bands were observed in the “Hail 548” and “Qatif 565” landraces. Genetic similarity based on Jaccard’s coefficient ranged from 0.53 to 1.00, with an average of 0.72. For molecular evaluation, 143 amplicons (fragments) were generated using 27 SRAP primer pair combinations, of which 88 were polymorphic across all the landraces. The PIC values ranged from 0.46 to 0.90, with an average of 0.76. All landraces showed an average of 0.66 similarity coefficient value. The UPGMA dendrogram supported by principal coordinate analysis (PCoA) revealed clusters of the landraces that almost corresponded to their geographical origin. Thus, seed storage protein profiling based on SDS-PAGE and SRAP markers can efficiently be used to assess genetic variability among tomato germplasms. The information obtained in the analysis will be of great interest in the management of ex situ collections for utilization in breeding programs or for direct use in quality markets. 相似文献
107.
Salem S. Alghamdi Muhammad A. Khan Ehab H. El-Harty Megahed H. Ammar Muhammad Farooq Hussein M. Migdadi 《Saudi Journal of Biological Sciences》2018,25(1):15-21
This study aimed to estimate the proximate, phenolic and flavonoids contents and phytochemicals present in seeds of twenty four soybeans (Glycine max (L.) Merr) genotypes to explore their nutritional and medicinal values. Crude protein composition ranged between 35.63 and 43.13% in Argentinian and USA (Clark) genotypes, respectively. Total phenolic content varied from 1.15 to 1.77?mg?GAE/g, whereas flavonoids varied from 0.68 to 2.13?mg?QE/g. The GC–MS analysis resulted identification of 88 compounds categorized into aldehydes (5), ketones (13), alcohols (5), carboxylic acids (7), esters (13), alkanes (2), heterocyclic compounds (19), phenolic compound (9), sugar moiety (7) ether (4) and amide (3), one Alkene and one fatty acid ester. Indonesian genotypes (Ijen and Indo-1) had the highest phenolic compounds than others genotype having antioxidant activities, while the Australian genotype contains the maximum in esters compounds. The major phytocompounds identified in majority of genotypes were Phenol, 2,6-dimethoxy-, 2-Methoxy-4-vinylphenol, 3,5-Dimethoxyacetophenone, 1,2-cyclopentanedione and Hexadecanoic acid, methyl ester. The presence of phytochemicals with strong pharmacological actions like antimicrobial and antioxidants activities could be considered as sources of quality raw materials for food and pharmaceutical industries. This study further set a platform for isolating and understanding the characteristics of each compound for it pharmacological properties. 相似文献
108.
R. Latif N. Rafique A. M. Salem Mona H. AlSheikh S. Chathoth 《Biological Rhythm Research》2018,49(2):169-174
We analyzed the association between kisspeptin and plasma adipokines (leptin and adiponectin) in normal-weight and over-weight young females. Thirty young Saudi females, based on their body mass index (BMI), were divided into two groups (15 students/group) as (1) Normal weight (NW): BMI = 18.5–24.99 and (2) Over-weight/obese (OW): BMI ≥ 25. Serum adipokines (leptin, adiponectin) and kisspeptin levels were measured in early follicular, pre-ovulatory, and luteal phase in both groups with ELISA. Menstrual cycle phases were confirmed by serum estradiol levels. There was no association of kisspeptin with leptin in early follicular (r ?0.34, P 0.31), pre-ovulatory (r ?0.32, P 0.34) and luteal phase (r 0.21, P 0.54). Likewise, kisspeptin was not found to be correlated with adiponectin in early follicular (r 0.41, P 0.21), pre ovulatory (r 0.24, P 0.48), and luteal phase (r 0.40, P 0.23) when values recorded during different time points during the cycle were plotted with each other. 相似文献
109.
Muhammad Afzal Salem Safer Alghamdi Muhammad Habib ur Rahman Awais Ahmad Tahir Farooq Mukhtar Alam Imtiaz Ali Khan Hidayat Ullah Wajid Nasim Shah Fahad 《Biotechnology letters》2018,40(3):479-492
As PCR methods have improved over the last 15 years, there has been an upsurge in the number of new DNA marker tools, which has allowed the generation of high-density molecular maps for all the key Brassica crop types. Biotechnology and molecular plant breeding have emerged as a significant tool for molecular understanding that led to a significant crop improvement in the Brassica napus species. Brassica napus possess a very complicated polyploidy-based genomics. The quantitative trait locus (QTL) is not sufficient to develop effective markers for trait introgression. In the coming years, the molecular marker techniques will be more effective to determine the whole genome impairing desired traits. Available genetic markers using the single-nucleotide sequence (SNP) technique and high-throughput sequencing are effective in determining the maps and genome polymorphisms amongst candidate genes and allele interactions. High-throughput sequencing and gene mapping techniques are involved in discovering new alleles and gene pairs, serving as a bridge between the gene map and genome evaluation. The decreasing cost for DNA sequencing will help in discovering full genome sequences with less resources and time. This review describes (1) the current use of integrated approaches, such as molecular marker technologies, to determine genome arrangements and interspecific outcomes combined with cost-effective genomes to increase the efficiency in prognostic breeding efforts. (2) It also focused on functional genomics, proteomics and field-based breeding practices to achieve insight into the genetics underlying both simple and complex traits in canola. 相似文献
110.