全文获取类型
收费全文 | 524篇 |
免费 | 39篇 |
国内免费 | 4篇 |
专业分类
567篇 |
出版年
2023年 | 5篇 |
2022年 | 12篇 |
2021年 | 13篇 |
2020年 | 11篇 |
2019年 | 18篇 |
2018年 | 16篇 |
2017年 | 9篇 |
2016年 | 32篇 |
2015年 | 35篇 |
2014年 | 37篇 |
2013年 | 28篇 |
2012年 | 37篇 |
2011年 | 34篇 |
2010年 | 22篇 |
2009年 | 14篇 |
2008年 | 37篇 |
2007年 | 34篇 |
2006年 | 25篇 |
2005年 | 19篇 |
2004年 | 25篇 |
2003年 | 13篇 |
2002年 | 8篇 |
2001年 | 10篇 |
2000年 | 7篇 |
1999年 | 3篇 |
1998年 | 7篇 |
1997年 | 6篇 |
1996年 | 4篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1992年 | 6篇 |
1991年 | 2篇 |
1990年 | 3篇 |
1989年 | 2篇 |
1988年 | 3篇 |
1987年 | 7篇 |
1986年 | 3篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1983年 | 4篇 |
1982年 | 4篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1970年 | 1篇 |
1963年 | 1篇 |
1931年 | 2篇 |
排序方式: 共有567条查询结果,搜索用时 15 毫秒
91.
El-Jawahri A Patel D Zhang M Mladkova N Chakravarti A 《Molecular diagnosis & therapy》2008,12(4):199-208
Gliomas are the most common primary brain tumors in adults. Anaplastic astrocytoma and glioblastoma multiforme represent malignant astrocytomas, which are the most common type of malignant gliomas. Despite research efforts in cancer therapy, the prognosis of patients with malignant gliomas remains poor. Research efforts in recent years have focused on investigating the cellular, molecular, and genetic pathways involved in the progression of malignant gliomas. As a result, biomarkers have emerged as diagnostic, predictive, and prognostic tools that have the potential to transform the field of brain tumor diagnostics. An increased understanding of the important molecular pathways that have been implicated in the progression of malignant gliomas has led to the identification of potential diagnostic, prognostic, and predictive biomarkers, some bearing clinical implications for targeted therapy. Some of the most promising biomarkers to date include loss of chromosomes 1p/19q in oligodendrogliomas and expression of O-6-methylguanine-DNA methyltransferase (MGMT) or epidermal growth factor receptor (EGFR) status in glioblastomas. Other promising biomarkers in glioma research include glial fibrillary acidic protein, galectins, Kir potassium channel proteins, angiogenesis, and apoptosis pathway markers. Research into the clinical relevance and applicability of such biomarkers has the potential to revolutionize our approach to the diagnosis and treatment of patients with malignant gliomas. 相似文献
92.
Procyclic Trypanosoma brucei cells were synchronized with 0.2 mM hydroxyurea. The cells did not arrest at the G1/S boundary but proceeded through one round of replication and arrested near the end of S phase. The mitochondrial genome (kinetoplast DNA network) replicated, forming two progeny networks, but the repair of minicircle gaps was inhibited. 相似文献
93.
AIM:
The study was aimed to determine the association of Apolipoprotein E (apo E) gene polymorphisms on lipid levels in Asian Indian population.METHODS:
A total of 350 (184 males and 166 females) adult (30 years and above) Asian Indians of Calcutta and suburb participated in the study. Anthropometric measures, lipids profiles, and blood glucose measures were collected. Out of 350 subjects, a sample of 70 individuals was selected randomly for genotyping after adjusting for age and sex. The apo E gene polymorphisms were determined by agarose gel electrophoresis.RESULTS:
The apo E polymorphism showed significant association with dyslipidaemia (P=0.0135) with ε3/4 combination has had the highest occurrence of dyslipidaemia and metabolic syndrome (MS) followed by ε4/4 <ε3/3 <ε2/4 <ε2/3 in decreasing order.CONCLUSIONS:
The ε4 allele of apo E gene independent of other risk factors is associated with dyslipidaemia in particular with low HDLc and high TC: HDLc ratio. 相似文献94.
Krishnendu Chandra Kaushik Ghosh Arnab K. Ojha Syed S. Islam 《Carbohydrate research》2009,344(16):2188-2194
A polysaccharide (PS-I) isolated from the aqueous extract of the unripe (green) tomatoes (Lycopersicon esculentum) consists of d-galactose, d-methyl galacturonate, d-arabinose, l-arabinose, and l-rhamnose. Structural investigation of the polysaccharide was carried out using total acid hydrolysis, methylation analysis, periodate oxidation study, and NMR studies (1H, 13C, DQF-COSY, TOCSY, NOESY, ROESY, HMQC, and HMBC). On the basis of above-mentioned experiments the structure of the repeating unit of the polysaccharide (PS-I) was established as:
相似文献
Full-size image (8K)
95.
96.
Karukayil J. Meenakumari Arnab Banerjee Amitabh Krishna 《Zoology (Jena, Germany)》2009,112(2):151-159
The primary aim of this study was to determine the possible cause of slow or delayed embryonic development in Cynopterus sphinx by investigating morphological and steroidogenic changes in the corpus luteum (CL) and circulating hormone concentrations during two pregnancies of a year. This species showed delayed post-implantational embryonic development during gastrulation of the first pregnancy. Morphological features of the CL showed normal luteinization during both pregnancies. The CL did not change significantly in luteal cell size during the delay period of the first pregnancy as compared with the second pregnancy. The circulating progesterone and 17β-estradiol concentrations were significantly lower during the period of delayed embryonic development as compared with the same stage of embryonic development during the second pregnancy. We also showed a marked decline in the activity of 3β-hydroxysteroid dehydrogenase, P450 side chain cleavage enzyme, and steroidogenic acute regulatory peptide in the CL during the delay period. This may cause low circulating progesterone and estradiol synthesis and consequently delay embryonic development. What causes the decrease in steroidogenic factors in the CL during the period of delayed development in C. sphinx is under investigation. 相似文献
97.
The effects of cell entrapment on the growth rate and metabolic activity of major groups of bacteria (betaproteobacteria and gammaproteobacteria) in biological municipal wastewater treatment were investigated. Three different cell entrapment media (alginate, carrageenan and polyvinyl alcohol) and three cell-to-matrix ratios (0.1%, 0.2% and 0.6%, w v−1) were examined. Representative species of betaproteobacteria were Alcaligenes faecalis and Comamonas testosteroni whereas Pseudomonas putida was a gammaproteobacteria species studied. Free (non-entrapped) cells were included in the study for comparative purpose. Results indicated that the entrapment, type of entrapment media, and cell-to-matrix ratio had significant effects on the growth and metabolic activity of major groups of bacteria in wastewater treatment. Polyvinyl alcohol entrapped cells had the highest specific growth and specific substrate utilization rates. Increase of cell-to-matrix ratio (from 0.1% to 0.2% or 0.6%) did not improve the specific growth and specific substrate utilization rates. The relative performances provided by different entrapment media of the three species studied were quite consistent. This study showed that the suitable choices of entrapment media and cell-to-matrix ratio are important but similar for major groups of bacteria in wastewater treatment. 相似文献
98.
99.
Tully DC Liu H Alper PB Chatterjee AK Epple R Roberts MJ Williams JA Nguyen KT Woodmansee DH Tumanut C Li J Spraggon G Chang J Tuntland T Harris JL Karanewsky DS 《Bioorganic & medicinal chemistry letters》2006,16(7):1975-1980
A series of N(alpha)-2-benzoxazolyl-alpha-amino acid-(arylaminoethyl)amides were identified as potent, selective, and noncovalent inhibitors of cathepsin S. Structure-activity relationships including strategies for modulating the selectivities among cathepsins S, K, and L, and in vivo pharmacokinetics are discussed. A X-ray structure of compound 3 bound to the active site of cathepsin S is also reported. 相似文献
100.
Tully DC Liu H Chatterjee AK Alper PB Williams JA Roberts MJ Mutnick D Woodmansee DH Hollenbeck T Gordon P Chang J Tuntland T Tumanut C Li J Harris JL Karanewsky DS 《Bioorganic & medicinal chemistry letters》2006,16(19):5107-5111
We report a novel series of noncovalent inhibitors of cathepsin S. The synthesis of the peptidomimetic scaffold is described and structure-activity relationships of P3, P1, and P1' subunits are discussed. Lead optimization to a non-peptidic scaffold has resulted in a new class of potent, highly selective, and orally bioavailable cathepsin S inhibitors. 相似文献