全文获取类型
收费全文 | 3064篇 |
免费 | 128篇 |
专业分类
3192篇 |
出版年
2024年 | 9篇 |
2023年 | 30篇 |
2022年 | 82篇 |
2021年 | 140篇 |
2020年 | 93篇 |
2019年 | 112篇 |
2018年 | 102篇 |
2017年 | 114篇 |
2016年 | 159篇 |
2015年 | 193篇 |
2014年 | 197篇 |
2013年 | 270篇 |
2012年 | 265篇 |
2011年 | 247篇 |
2010年 | 149篇 |
2009年 | 111篇 |
2008年 | 129篇 |
2007年 | 136篇 |
2006年 | 120篇 |
2005年 | 100篇 |
2004年 | 90篇 |
2003年 | 63篇 |
2002年 | 56篇 |
2001年 | 18篇 |
2000年 | 20篇 |
1999年 | 22篇 |
1998年 | 17篇 |
1997年 | 7篇 |
1996年 | 10篇 |
1995年 | 5篇 |
1994年 | 6篇 |
1993年 | 5篇 |
1992年 | 5篇 |
1991年 | 4篇 |
1990年 | 7篇 |
1989年 | 6篇 |
1988年 | 7篇 |
1987年 | 4篇 |
1986年 | 3篇 |
1985年 | 6篇 |
1984年 | 8篇 |
1983年 | 3篇 |
1982年 | 5篇 |
1977年 | 3篇 |
1975年 | 4篇 |
1974年 | 7篇 |
1973年 | 14篇 |
1972年 | 5篇 |
1971年 | 5篇 |
1970年 | 5篇 |
排序方式: 共有3192条查询结果,搜索用时 0 毫秒
111.
112.
113.
Mohd Ishtikhar Anam Khan Chih-Kai Chang Lilian Tsai-Wei Lin Steven S.-S. Wang 《Journal of biomolecular structure & dynamics》2016,34(7):1409-1420
6-thioguanine (6-TG) is an antineoplastic, nucleobase guanine, purine analog drug belongs to thiopurine drug-family of antimetabolites. In the present study, we report an experimental approach towards interaction mechanism of 6-TG with human serum albumin (HSA) and examine the chemical stability of HSA in the presence of denaturants such as guanidine hydrochloride (GdnHCl) and urea. Interaction of 6-TG with HSA has been studied by various spectroscopic and spectropolarimeteric methods to investigate what short of binding occurs at physiological conditions. 6-TG binds in the hydrophobic cavity of subdomain IIA of HSA by static quenching mechanism which induces conformation alteration in the protein structure. That helpful for further study of denaturation process where change in secondary structures causes unfolding of protein that also responsible for severance of domain III from rest of the protein part. We have also performed molecular simulation and molecular docking study in the presence of denaturating agents to determine the binding property of 6-TG and the effect of denaturating agents on the structural activity of HSA. We had found that GdnHCl is more effective denaturating agent when compared to urea. Hence, this study provides straight evidence of the binding mechanism of 6-TG with HSA and the formation of intermediate or unfolding transition that causes unfolding of HSA. 相似文献
114.
115.
Reproductive hormones play a significant role in the gonadal development and gametogenesis process of animals. In the present study luteinizing hormone beta, (lhb) subunit gene was cloned and characterized from the brain of Catla catla. The lhb full-length of cDNA sequence is 629 bp which consists of 43bp 5'-UTR (untranslated region) 447bp, ORF(open reading frame) and 139 bp of 3'-UTR respectively. The coding region of lhb gene encoded a peptide of 148 amino acids. The coding sequence of lhb gene consist of a single N-linked glycosylation site (NET) and 12 cysteine knot residues. Phylogenetic analysis of C. catla Lhβ deduced amino acid sequence showed high similarity with Carassius auratus followed by Gobiocypris rarus. 3D structure Lhβ protein comprises of five β-sheets and six coils/loops. The qPCR results revealed lhb mRNA is mainly expressed in the pituitary, ovary while moderate expression was observed in brain and testis. To best our knowledge, this is the first report on the identification, molecular characterization and structural information regarding luteinizing hormone in Indian major carp. 相似文献
116.
Azar Ullah Mirza Mohd Shoeb Khan Shahab A. A. Nami Abdul Kareem Sumbul Rehman Shahnawaz Ahmad Bhat Nahid Nishat 《化学与生物多样性》2019,16(8)
Copper oxide nanomaterials were synthesized by a facile sustainable biological method using two plant species (Zanthoxylum armatum DC. and Berberis lycium Royle ). The formation of materials was confirmed by FT‐IR, ATR, UV‐visible, XRD, TEM, SEM, EDX, TGA and PL. The antibacterial activity was evaluated by agar well diffusion method to ascertain the efficacy of plant species extract and extract derived copper oxide nanomaterials against six Gram‐positive bacteria namely Staphylococcus aureus, Streptococcus mutans, Streptococcus pyogenes, Corynebacterium diphtheriae, Corynebacterium xerosis, Bacillus cereus and four Gram‐negative bacteria such as Klebsiella pneumonia, Escherichia coli, Pseudomonas aeruginosa and Proteus vulgaris against the standard drug, Ciprofloxacin for Gram‐positive and Gentamicin for Gram‐negative bacteria, respectively. In both cases, copper oxide nanomaterials were found to be sensitive in all the bacterial species. Sensitivity of copper oxide nanomaterials shows an be higher as compared to plant species extract against different bacteria. Scavenging activity of plant extracts along with nanomaterials have been accessed using previously reported protocols employing ascorbic acid as standard. Scavenging activity of copper oxide nanomaterials shows an increase with increase in concentration. The biological activity (bactericidal and scavenging efficiency) of plant derived copper oxide nanomaterials revealed that these materials can be used as potent antimicrobial agent and DPPH scavengers in industrial as well as pharmacological fields. 相似文献
117.
Bioprocess and Biosystems Engineering - Inulinases are used for the production of high-fructose syrup and fructooligosaccharides, and are widely utilized in food and pharmaceutical industries. In... 相似文献
118.
Abdul Rahman Amirah Mokhtar Norfilza Mohd Harun Roslan Jamal Rahman Wan Ngah Wan Zurinah 《Journal of physiology and biochemistry》2019,75(4):499-517
Journal of Physiology and Biochemistry - Gamma-tocotrienol (GTT) and hydroxychavicol (HC) exhibit anticancer activity in glioma cancer cells, where the combination of GTT + HC was shown to be more... 相似文献
119.
Mustafa A. Gassem 《Saudi Journal of Biological Sciences》2019,26(1):137-140
The Hout-Kasef is traditional salted fermented fish product of natural fermentation of salted mullet fish of coastal area of Jazan region of Saudi Arabia. The present study was carried out to investigate the microbiological and chemical characteristic of Hout-Kasef. A total of twenty-four salted fish samples were purchased from fish market in Jazan and Abu-Arish at different times of the year. The microbial studies of salted-fermented fish revealed a total bacterial count ranging from 2.81 to 4.72 Log10 CFU/g, yeast and mold counts ranging from 0.48 to 3.14 Log10 CFU/g, total staphylococci count 2.71–3.85 Log10 CFU/g, halophile bacteria count 3.26–5.14 Log10 CFU/g, and coliforms count <1 Log10 CFU/g. However, pathogenic bacteria such as Listeria monocytogenes, Vibrio spp., Campylobacter spp. and Yersinia species were not detected. The major bacteria species isolated and identified from the salted fermented fish were Bacillus Subtilus, Bacillus mycoides, Bacillus licheniformis, Bacillus pumilus, Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus hominis, Staphylococcus xylosus, Staphylococcus saprophticus and Staphylococcus cahnii subsp cahnii. The chemical analysis of salted fermented fish showed high content of moisture (47.96%), protein (25.71%), ash (19.6%) and salt (15.19%) but low contents of lipid (7.25%). The salted-fermented fish also showed high level of total volatile basic nitrogen (78.86 mg/100 gm sample) and thiobarbutric acid number (32.32 mg malonaldehyde/kg) with a pH value of pH 6.3. Finally, this study showed the presence of gram positive and gram negative bacteria in the fish product. The predominant microorganisms found were Bacillus and Staphylococcus spp. The fish product had high content of salt and TVB-N levels. 相似文献
120.
Muhammad Khairul Izzuddin Sharaai Amir Hamzah Ismail Mohd Mansor Harun Rosta Yien Wong Siew 《The International Journal of Life Cycle Assessment》2019,24(5):935-944
The International Journal of Life Cycle Assessment - Palm oil is considered as the primary source of income for many farmers in Southeast Asia and become a very important agricultural commodity for... 相似文献