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   512篇
  免费   30篇
  国内免费   5篇
耳鼻咽喉   1篇
儿科学   13篇
妇产科学   9篇
基础医学   63篇
口腔科学   10篇
临床医学   65篇
内科学   107篇
皮肤病学   11篇
神经病学   14篇
特种医学   17篇
外科学   59篇
综合类   21篇
预防医学   29篇
眼科学   3篇
药学   44篇
中国医学   1篇
肿瘤学   80篇
  2023年   4篇
  2022年   6篇
  2021年   21篇
  2020年   11篇
  2019年   11篇
  2018年   9篇
  2017年   6篇
  2016年   16篇
  2015年   18篇
  2014年   27篇
  2013年   17篇
  2012年   29篇
  2011年   46篇
  2010年   14篇
  2009年   26篇
  2008年   33篇
  2007年   36篇
  2006年   36篇
  2005年   36篇
  2004年   32篇
  2003年   24篇
  2002年   28篇
  2001年   1篇
  2000年   1篇
  1999年   3篇
  1998年   5篇
  1997年   6篇
  1996年   7篇
  1995年   6篇
  1994年   4篇
  1993年   3篇
  1992年   2篇
  1991年   6篇
  1987年   3篇
  1986年   5篇
  1984年   2篇
  1983年   2篇
  1982年   2篇
  1978年   1篇
  1976年   1篇
  1973年   1篇
排序方式: 共有547条查询结果,搜索用时 15 毫秒
81.
The associations of GRIN2B polymorphism (rs1806201) with alcohol withdrawal and related clinical parameters in alcohol dependent subjects were investigated. Cases were assessed using a semi-structured clinical pro forma for alcohol abuse and a questionnaire for family history of alcohol dependence and psychiatric disorders after obtaining informed consent. The study included alcohol dependent male cases (n = 220, age at onset of alcohol withdrawal symptoms = 32.4 ± 8.8 y) recruited at the Center for Addiction Medicine, National Institute of Mental Health and Neurosciences, Bangalore, India. The controls comprised of healthy unrelated males (n = 183) who were ethnically matched and selected randomly. The polymorphism rs1806201 was analyzed by polymerase chain reaction and restriction fragment length polymorphism. The presence of T allele at this locus was significantly associated with lower age at onset of alcohol withdrawal symptoms (p = .005) among the cases. Mean age at onset of alcohol withdrawal symptoms in subjects who were T carriers was 31.4 ± 8.5 y (n = 160) and non-T carriers was 35.2 ± 9.0 y (n = 60). The SNP rs1806201 in GRIN2B may play an important role in genetic susceptibility to earlier age of withdrawal in alcohol dependent patients.  相似文献   
82.
There is little consensus regarding the most appropriate dosage regimen for radioiodine treatment in Graves' disease. The authors evaluated the efficacy of low fixed dose (5mCi) of radioiodine therapy, in terms of its cure rate and promptness of control, as well possible factors influencing the outcome. One hundred and twenty five consecutive patients with Graves' disease with persistent disease activity despite receiving carbimazole were treated with 5 mCi fixed dose of I131. Patients, who remained hyperthyroid at 1 year, received a second dose of 7.5 mCi of I113. After first dose 73.6% were cured (36.8% hypothyroid and 36.8% euthyroid), while 26.4% patients did not respond. Those who achieved cure had significantly lesser goiter size (84.6% with grade I goiter and 70.7% with grade II) and had received significantly shorter duration of prior carbimazole therapy (22 +/- 10 months versus 63 +/- 27 months) (p < 0.01). Age, sex, baseline T3, T4, 24 hour I131 uptake did not affect the cure rate. Mean time to response was 7 +/- 4 months. One hundred and three (82.4%) patients were cured after 2 doses while only 22 (17.6%) were nonresponsive. Hence, low fixed dose (5mCi) radio active iodine (RAI) therapy seems to be effective in Graves' disease particularly in patients with small sized goiter and short duration of pretherapy with thionamides.  相似文献   
83.

Purpose

A demonstration project was conducted to assess feasibility of implementing HPV detection-based cervical cancer screening in primary care settings in India and to generate local evidence on feasibility and effectiveness of HPV detection in primary screening.

Methods

The project was implemented by setting up screening clinics at primary health centers. Eligible women were screened by HPV DNA test (Hybrid capture 2). All samples were processed and tested in a single laboratory. Colposcopy services were provided to screen-positive women at the same community clinics. Project utilized services of community health workers for community mobilization, recall of screen-positive and disease-positive women. Women with ≥CIN2 diagnosis were treated at tertiary hospital.

Results

Totally, 44,110 women were screened and HPV positivity was 4.7 %. Compliance to recall of HC2-positive women for colposcopy was 78 %. Detection rate of CIN3+ by HPV test was 3.9/1,000 women. Compliance of women to treatment was 80.1 %. However, compliance of HPV-positive women for follow-up at 1 year was poor (23.2 %). Concurrent use of VIA to screen the women did not have any advantage but increased number of unnecessary colposcopies and biopsies.

Conclusions

Our project demonstrated that it was possible to implement HPV detection-based screening using existing primary healthcare infrastructure. Performing colposcopy at primary setting is feasible, improves compliance and reduces over-treatment. In settings with low to moderately high HPV prevalence, direct referral of HPV-positive women is advisable. Community health workers can be effectively used for recalling the positive women.
  相似文献   
84.
85.
BACKGROUND: Worldwide coronary heart disease (CHD) is estimated to be the leading cause of death. Current knowledge about prevention of CHD is mainly derived from developed countries. Therefore, this study aimed to find out the association of CHD with ratios of different lipoproteins and apolipoproteins, LDL particle size, as well as different traditional risk factors in Asian Indian population in Eastern part of India. METHODS: Case-control study of 100 patients with CHD and 98 healthy controls were age and sex matched. After clinical evaluation, blood samples were collected for biochemical assays. RESULTS: Multivariate logistic regression analysis found apoB (OR 2.96; 95% CI 1.02-8.54), apoB/HDL-c (OR 4.14; 95% CI 1.33-12.83), nonHDL-c (OR 5.41; 95% CI 2.08-14.10), apoB/apoAI (OR 6.64; 95% CI 2.37-18.57), and LDL particle size (9.59; 95% CI 2.92-31.54) were independently associated with CHD. Area under the ROC curves derived from the model (AUROC 0.947; 95% CI 0.916-0.977) are significantly higher than any other variables. CONCLUSIONS: Findings from the multivariate analysis, apoB, apoB/HDL-c, nonHDL-c, apoB/apoAI, and LDL particle size are potent indicators and useful for diagnosis of predisposed CHD.  相似文献   
86.
Malaria continues to be a significant public health problem threatened by the emergence and spread of resistance to artemisinin-based combination therapies and marked half a million deaths in 2016. A new imidazopyridine chemotype has been envisaged through scaffold-hopping approach combined with docking studies for putative-binding interactions with Plasmodium falciparum phosphatidylinositol-4-kinase (PfPI4K) target. The docking results steered to the synthesis of compound 1 [5-(3-(methylsulfonyl)phenyl)-3-(4-(methylsulfonyl)phenyl)-3H-imidazo[4,5-b]pyridine] followed by the in vitro screening for antiplasmodial activity and ADME-PK studies. Combined with potent antimalarial activity of compound 1 (Pf3D7 IC50 = 29 nM) with meager in vitro intrinsic clearance, moderate plasma-protein binding, and acceptable permeability, compound 1 displayed sustained exposure and high oral bioavailability in mice and can thus have the potential as next generation PI4K inhibitor for in vivo studies.  相似文献   
87.
Herein, we report a simple, sensitive, rapid and low-cost ultraminiaturized assay technique for quantitative detection of 1 μl of clinical or biochemical sample on a novel ultraminiaturized assay plate (UAP). UAP is prepared by making tiny cavities on a polypropylene sheet. As UAP cannot immobilize a biomolecule through absorption, we have activated the tiny cavities of UAP by 1-fluoro-2-nitro-4-azidobenzene in a photochemical reaction. Activated UAP (AUAP) can covalently immobilize any biomolecule having an active nucleophilic group such as amino group. Efficacy of AUAP is demonstrated by detecting human IgE, antibody of hepatitis C virus core antigen and oligonucleotides. Quantification is performed by capturing the image of the colored assay solution and digitally quantifying the image by color saturation without using costly NanoDrop spectrophotometer. Image - based detection of human IgE and an oligonucleotide shows an excellent correlation with absorbance - based assay (recorded in a NanoDrop spectrophotometer); it is validated by Pearson’s product–moment correlation with correlation coefficient of r?=?0.9545088 and r?=?0.9947444 respectively. AUAP is further checked by detecting hepatitis C virus Ab where strong correlation of color saturation with absorbance with respect to concentration is observed. Ultraminiaturized assay successfully detects target oligonucleotides by perfectly hybridizing with their respective complementary oligonucleotide probes but not with a random oligonucleotide. Ultraminiaturized assay technique has substantially reduced the requirement of reagents by 100 times and assay timing by 50 times making it a potential alternative to conventional method.  相似文献   
88.
89.
Tea (Camellia sinensis L.) leaves undergo complex chemical transformations during black tea processing. However, the dynamic chemical changes during tea processing have not been explored in popular cultivars of North East India. In this study, changes in catechins, caffeine, total polyphenol (TP) and formation of theaflavins were examined throughout the different stages of CTC (curl, tear and crush) black tea processing based on UPLC metabolomic analysis along with antioxidant activity for eight cultivars viz. S.3A/3, TV1, TV7, TV9, TV17, TV22, TV23 and TV25. The results demonstrated that the most prolific changes were observed after complete maceration of tea leaves. The total catechin, (−)-epigallocatechin gallate and (−)-epicatechin gallate levels decreased by 96, 97 and 89%, respectively as the processing progressed from fresh leaves to black tea. The TP level decreased by 26 to 37% throughout the processing path. The caffeine content increased by 18% during processing. The total theaflavin reached the highest level at 20 min of fermentation and then decreased by 13 to 36% at 40 min. Cultivar TV23 and S.3A/3 had a high content of total theaflavin with 17.9 and 16.9 mg g−1, respectively. The antioxidant activity was observed to be decreased by 31% for the black tea as compared to fresh leaves. It is also observed that the total phenolic content exerted a greater effect on antioxidant activity rather than catechins and theaflavins. This study provides an insightful observation of black tea processing which will immensely help in improving the quality of processed tea.

Changes in catechins, caffeine, total polyphenol, theaflavins, and antioxidant activity during CTC processing of black tea from North East India cultivar were studied. Total polyphenol decreased up to 37% with the formation of theaflavins up to 1.8%.  相似文献   
90.
Memory-epigenetics which is the loss of memory due to epigenetic modifications can be due to the silencing of genes involved in cognitive functions and this is the basis of the current study.We hypothesize that a diet containing high methionine and low vitamins can lead to memory impairment by increasing global DNA methylation and therefore,silencing the netrin-1 gene,which encodes the glycoprotein involved in neurogenesis,axonal guidance and maintenance of the synaptic plasticity.Wild type(C57 BL/6 J) mice were fed with a diet containing excess methionine(1.2%),low-folate(0.08 mg/kg),vitamin B_6(0.01 mg/kg),and B_(12)(10.4 mg/kg) for 6 weeks.Mice were examined weekly for the long-term memory function,using a passive avoidance test,which determined loss of fear-motivated long-term memory starting from the fourth week of diet.Similarly,an increase in brain %5-methyl cytosine was observed starting from the 4 th week of diet in mice.Mice fed with a high methionine,low folate and vitamins containing diet showed a decrease in netrin-1 protein expression and an increase in netrin-1 gene promotor methylation,as determined by methylation-sensitive restriction enzyme-polymerase chain reaction analysis.The increase in methylation of netrin-1 gene was validated by high-resolution melting and sequencing analysis.Furthermore,the association of netrin-1 with memory was established by administering netrin that considerably restored long-term fear motivated memory.Taken together,these results suggest that a diet rich in methionine and lacking in folate and vitamin B_6/B_(12) can induce defects in learning and memory.Furthermore,the data indicates that decrease in netrin-1 expression due to hyper-methylation of its gene can be associated with memory loss.The animal procedures were approved by the Institutional Animal Care and Use Committee,University of Louisville,USA(No.A3586-01) on February 2,2018.  相似文献   
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