首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   735篇
  免费   43篇
  国内免费   5篇
耳鼻咽喉   7篇
儿科学   36篇
妇产科学   19篇
基础医学   55篇
口腔科学   9篇
临床医学   38篇
内科学   207篇
皮肤病学   19篇
神经病学   44篇
特种医学   47篇
外科学   97篇
综合类   10篇
现状与发展   1篇
预防医学   27篇
眼科学   10篇
药学   95篇
中国医学   9篇
肿瘤学   53篇
  2023年   2篇
  2022年   12篇
  2021年   34篇
  2020年   15篇
  2019年   21篇
  2018年   40篇
  2017年   19篇
  2016年   24篇
  2015年   25篇
  2014年   35篇
  2013年   43篇
  2012年   65篇
  2011年   61篇
  2010年   27篇
  2009年   29篇
  2008年   32篇
  2007年   41篇
  2006年   31篇
  2005年   16篇
  2004年   15篇
  2003年   15篇
  2002年   18篇
  2001年   5篇
  2000年   6篇
  1999年   4篇
  1998年   6篇
  1997年   6篇
  1996年   3篇
  1995年   3篇
  1994年   6篇
  1993年   3篇
  1992年   6篇
  1991年   18篇
  1990年   16篇
  1989年   17篇
  1988年   14篇
  1987年   9篇
  1986年   4篇
  1985年   2篇
  1984年   3篇
  1983年   6篇
  1982年   2篇
  1980年   2篇
  1979年   6篇
  1978年   3篇
  1977年   3篇
  1976年   2篇
  1975年   3篇
  1967年   2篇
  1966年   1篇
排序方式: 共有783条查询结果,搜索用时 15 毫秒
151.
152.

Objective

To study the prevalence of prediabetes among school children in Mysore city.

Design

Cross sectional study.

Settings

Children aged 5–10 years from three schools in Mysore city were included. Study was done over a period of 1 year during 2006–2007.

Participants

726 children (59.8% males).

Main Outcome

Prevalence of prediabetes. Prediabetes was defined as fasting blood sugar level between 100–125 mg/dL.

Results

The prevalence of prediabetes was 3.7%. No statistically significant association was observed with major risk factors of diabetes.

Conclusions

Efforts must be made to recognize type 2 diabetes in the asymptomatic prediabetes state.  相似文献   
153.
ContextStreptomyces species are prolific sources of bioactive secondary metabolites known especially for their antimicrobial and anticancer activities.ObjectiveThis study sought to isolate and characterize antioxidant molecules biosynthesized by Streptomyces sp. KTM18. The antioxidant potential of an isolated compound and its toxicity were accessed.Materials and methodsThe compound was purified using bioassay-guided chromatography techniques. Nuclear magnetic resonance (NMR) experiments were carried out for structure elucidation. The antioxidant potential of the isolated compound was determined using DPPH free radical scavenging assay. The toxicity of the isolated compound was measured using a brine shrimp lethality (BSL) assay.ResultsEthyl acetate extract of Streptomyces sp. KTM18 showed more than 90% inhibition of DPPH free radical at 50 µg/mL of the test concentration. These data were the strongest among 13 Streptomyces isolates (KTM12–KTM24). The active molecule was isolated and characterized as maculosin (molecular formula, C14H16N2O3 as determined by the [M + H]+ peak at 261.1259). The DPPH free radical scavenging activity of pure maculosin was higher (IC50, 2.16 ± 0.05 µg/mL) than that of commercial butylated hydroxyanisole (BHA) (IC50, 4.8 ± 0.05 µg/mL). No toxicity was observed for maculosin (LD50, <128 µg/mL) in brine shrimp lethality assay (BSLA) up to the compound’s antioxidant activity (IC50) concentration range. The commercial standard, berberine chloride, showed toxicity in BSLA with an LD50 value of 8.63 ± 0.15 µg/mL.ConclusionsMaculosin may be a leading drug candidate in various cosmetic and therapeutic applications owing to its strong antioxidant and non-toxic properties.  相似文献   
154.
Tenascin-C (TNC), a major component of the extracellular matrix, is strongly upregulated after injuries of the central nervous system (CNS) but its role in tissue repair is not understood. Both regeneration promoting and inhibiting roles of TNC have been proposed considering its abilities to both support and restrict neurite outgrowth in vitro. Here, we show that spontaneous recovery of locomotor functions after spinal cord injury is impaired in adult TNC-deficient (TNC–/–) mice in comparison to wild-type (TNC+/+) mice. The impaired recovery was associated with attenuated excitability of the plantar Hoffmann reflex (H-reflex), reduced glutamatergic input, reduced sprouting of monaminergic axons in the lumbar spinal cord and enhanced post-traumatic degeneration of corticospinal axons. The degeneration of corticospinal axons in TNC–/– mice was normalized to TNC+/+ levels by application of the alternatively spliced TNC fibronectin type III homologous domain D (fnD). Finally, overexpression of TNC-fnD via adeno-associated virus in wild-type mice improved locomotor recovery, increased monaminergic axons sprouting, and reduced lesion scar volume after spinal cord injury. The functional efficacy of the viral-mediated TNC indicates a potentially useful approach for treatment of spinal cord injury.  相似文献   
155.
Moya Moya cases treated with encephaloduroarteriosynangiosis   总被引:1,自引:0,他引:1  
OBJECTIVE: To study neurological outcome of Moya Moya disease treated surgically with Encephaloduroarteriosynengopsis (EDAS). DESIGN: Prospective observational study. SETTINGS: Community and General with tertiary care facility. SUBJECTS: Eight children diagnosed with Moya Moya disease by Magnetic Resonance Angiogramover 4 years of period were selected for EDAS. Children who were not able to sustain surgery excluded from study. METHODS: Treatment modality selected were surgery in form of EDAS. After surgery subjects were followed up for minimum of 2 year period to know neurological out come. Outcome was reported as poor, fair, good and excellent. No statistical analysis performed due to small sample size. RESULTS: After surgery no episode of stroke or TIA was observed in any patient during 2 year follow up period and all patients are living without any new neurological deficit. CONCLUSION: Long term outcome of EDAS is promising.  相似文献   
156.
Lung cancer is characterized by abnormal cell growth and invasion, and the actin cytoskeleton plays a major role in these processes. The focal adhesion protein paxillin is a target of a number of oncogenes involved in key signal transduction and important in cell motility and migration. In lung cancer tissues, we have found that paxillin was highly expressed (compared with normal lung), amplified (12.1%, 8 of 66) and correlated with increased MET and epidermal growth factor receptor (EGFR) gene copy numbers, or mutated (somatic mutation rate of 9.4%, 18 of 191). Paxillin mutations (19 of 21) were clustered between LD motifs 1 and 2 and the LIM domains. The most frequent point mutation (A127T) enhanced lung cancer cell growth, colony formation, focal adhesion formation, and colocalized with Bcl-2 in vitro. Gene silencing from RNA interference of mutant paxillin led to reduction of cell viability. A murine in vivo xenograft model of A127T paxillin showed an increase in tumor growth, cell proliferation, and invasion. These results establish an important role for paxillin in lung cancer.  相似文献   
157.
We report a sensitive method for the estimation of quinine (Qn), cinchonine (Cn), and cinchonidine (Cnd) and a new method based on fluorescence enhancement and detection and quantification of quinidine (Qnd) from Cinchona stem bark and its formulations, using HPTLC. Standard solutions of Qn, Qnd, Cn, and Cnd were applied on precoated HPTLC plates and developed with chloroform/diethylamine (9.6:1.4 v/v). The plates were scanned and quantified at 226 nm for Qn, Cn, Cnd and for Qnd at 366 nm in fluorescence and reflectance mode ([symbol: see text] K400 filter). The method was validated for precision, accuracy and repeatability. Further, the stem bark of Cinchona officinalis and some herbal and homeopathic formulations were evaluated for their individual alkaloid content applying the developed method.  相似文献   
158.
OBJECTIVE: To compute quantitative estimates of the tridosha--the qualitative characterization that constitutes the core of diagnosis and treatment in Ayurveda--to provide a basis for biostatistical analysis of this ancient Indian science, which is a promising field of alternative medicine. SUBJECTS: The data sources were 280 persons from among the residents and visitors/training students at the Brahmvarchas Research Centre and Shantikuj, Hardwar, India. DESIGN/METHODOLOGY: A quantitative measure of the tridosha level (for vata, pitta, and kapha) is obtained by applying an algorithmic heuristic approach to the exhaustive list of qualitative features/factors that are commonly used by Ayurvedic doctors. A knowledge-based concept of worth coefficients and fuzzy multiattribute decision functions are used here for regression modeling. VALIDATION AND APPLICATIONS: Statistical validation on a large sample shows the accuracy of this study's estimates with statistical confidence level above 90%. The estimates are also suited for diagnostic and prognostic applications and systematic drug-response analysis of Ayurvedic (herbal and rasayanam) medicines. An application with regard to the former is elucidated, extensions of which might also be of use in investigating the role of nadis in Ayurvedic healing vis-a-vis acupuncture and acupressure techniques. The importance and scope of this novel approach are discussed. CONCLUSIONS: This pioneering study shows that the concept of tridosha has a sound empirical basis that could be used for the scientific establishment of Ayurveda in a new light.  相似文献   
159.
A new approach for the design and synthesis of cyclic N-halamine polymers having anti-bacterial activity based on a vinyl derivative of tyrosine-derived hydantoin is reported. The synthesis of N-halamine polymers generally involves the chemical modification of 5,5′-disubstituted hydantoin to introduce polymerizable vinyl moieties thereby restricting the halogen capture only on the amide nitrogen. Here we show the possibility of synthesizing vinyl monomers of N-halamine from α-amino acids wherein both the amide and imide nitrogens are available for halogen capture. Thus, a hydantoin monomer was synthesized from L-tyrosine and copolymerized with methyl methacrylate and 2-(hydroxyethyl)methacrylate, to obtain random co-polymers. The monomer and its co-polymers were characterized using NMR, IR, HRMS, GPC, DSC, EDAX and TGA analysis. Films of the co-polymers cast from 10% acetone solutions were exposed to sodium hypochlorite solution to activate the hydantoin moieties. The oxidative chlorine content of the films ranged from 0.6 to 0.9%. The activated films were exposed to both Gram positive (S. aureus) and Gram negative (E. coli) bacteria using standard protocols. Polymers having chlorine content as little as 0.6% exhibited 6 log reduction in the bacterial growth within 30 min of exposure. The method allows the halogenation of both amide and imide nitrogens and could be applied to the preparation of a number of vinyl hydantoins from many amino acids.  相似文献   
160.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号