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   346篇
  免费   27篇
耳鼻咽喉   5篇
儿科学   38篇
妇产科学   7篇
基础医学   41篇
口腔科学   44篇
临床医学   14篇
内科学   84篇
皮肤病学   13篇
神经病学   10篇
特种医学   8篇
外科学   34篇
综合类   3篇
预防医学   19篇
眼科学   7篇
药学   22篇
肿瘤学   24篇
  2022年   3篇
  2021年   8篇
  2020年   6篇
  2019年   13篇
  2018年   17篇
  2017年   10篇
  2016年   14篇
  2015年   13篇
  2014年   16篇
  2013年   28篇
  2012年   38篇
  2011年   35篇
  2010年   17篇
  2009年   21篇
  2008年   16篇
  2007年   20篇
  2006年   22篇
  2005年   7篇
  2004年   8篇
  2003年   9篇
  2002年   13篇
  2001年   8篇
  2000年   3篇
  1999年   2篇
  1998年   4篇
  1997年   5篇
  1995年   2篇
  1994年   1篇
  1993年   1篇
  1992年   4篇
  1990年   2篇
  1989年   2篇
  1988年   1篇
  1983年   1篇
  1980年   1篇
  1973年   1篇
  1966年   1篇
排序方式: 共有373条查询结果,搜索用时 15 毫秒
81.
CD4+ T‐cell levels are an important criterion for categorizing HIV‐related clinical conditions according to the CDC classification system and are therefore important in the management of HIV by initiating antiretroviral therapy and prophylaxis for opportunistic infections due to HIV among HIV‐infected individuals. However, it has been observed that the CD4 counts are affected by the geographical location, race, ethnic origin, age, gender and changes in total and differential leucocyte counts. In the light of this knowledge, we classified 600 HIV seropositive antiretroviral treatment (ART)‐naïve Indian individuals belonging to different CDC groups A, B and C on the basis of CDC criteria of both CD4% and CD4 counts and receiver operating characteristic (ROC) curves were generated. Importantly, CDC staging on the basis of CD4% indicated significant clinical implications, requiring an early implementation of effective antiretroviral treatment regimen in HIV‐infected individuals deprived of treatment when classified on the basis of CD4 counts.  相似文献   
82.
We have developed a PCR assay that is capable of amplifying kinetoplast DNA (kDNA) of Leishmania donovani in a species-specific manner among Old World leishmanias. With Indian strains and isolates of L. donovani the assay was sensitive enough to detect kDNA in an amount equivalent to a single parasite or less. The extreme sensitivity of the assay was reflected in its ability to detect parasite DNA from small volumes of peripheral blood of patients with kala-azar (KA) and from skin lesions from patients with post-KA dermal leishmaniasis (PKDL). A total of 107 clinical leishmaniasis samples were analyzed. Of these 102 (95.3%) were positive by PCR. The test provided a diagnosis of KA with 96% sensitivity using patient whole-blood samples instead of bone marrow or spleen aspirates that are obtained by invasive procedures. The assay was also successful in the diagnosis of 45 of 48 PKDL cases (93.8%). Cross-reactions with pathogens prevalent in the area of endemicity, viz., Mycobacterium tuberculosis, Mycobacterium leprae, and Plasmodium spp., could be ruled out. Eighty-one control samples, including dermal scrapings from healthy portions of skin from patients with PKDL were all negative. Two of twenty controls from the area of endemicity were found positive by PCR assay; however, there was a good possibility that these two were asymptomatic carriers since they were serologically positive for KA. Thus, this PCR assay represents a tool for the diagnosis of KA and PKDL in Indian patients in a noninvasive manner, with simultaneous species identification of parasites in clinical samples.  相似文献   
83.
84.
Objective: To study the effect of cardiopulmonary bypass (CPB) on serum thyroid hormone profile in children undergoing open‐heart surgery. Design: Prospective cross‐sectional study. Setting: Multispecialty tertiary level referral center. Patients: One hundred consecutive patients (age 15.9 ± 14.6 months, weight 6.7 ± 2.5 kg) undergoing open‐heart surgery under CPB. Interventions: None. Outcome Measures: Levels and trends of serum total thyroxine (TT4), free thyroxine (FT4), total tri‐iodothyronine (TT3), free tri‐iodothyronine (FT3) and thyroid stimulating hormone (TSH), survival, inotropic score, duration of mechanical ventilation, postoperative complications. Results: TT4 levels were 9.08 ± 3.6, 6.4 ± 2.5, 6.24 ± 2.1, 6.43 ± 2.4, 7.20 ± 3.0 µg/dL at baseline and at 1, 24, 48 and 72 hours; FT4 levels were 1.82 ± 0.5, 1.49 ± 0.3, 1.29 ± 0.3, 1.32 ± 0.4, and 1.43 ± 0.5 ng/dL; TT3 levels were 1.81 ± 0.4, 1.31 ± 0.3, 0.99 ± 0.2, 1.0 ± 0.37, and 1.17 ± 0.48 ng/ml; FT3 levels were 4.09 ± 1.0, 3.02 ± 0.8, 2.21 ± 0.6, 2.22 ± 0.7, and 2.66 ± 1.05 pg/ml; TSH levels were 5.40 ± 3.8, 2.0 ± 3.1, 1.24 ± 1.1, 2.90 ± 3.3, and 4.03 ± 3.4 mIU/L. There was significant fall (29.1% for FT4, 32.1% for TT4, 77% for TSH, 46% for FT3 and 45% for TT3, p < 0.0001). When area under curve (AUC) TT4 was compared between survivors (n = 87) and nonsurvivors (n = 12), significantly larger AUC was seen in survivors (492.81 ± 158.6) than nonsurvivors (360.75 ± 179.6 p = 0.0125). In survivors >72 hours, AUC TT4 was larger in patients with uneventful postoperative course versus those with postoperative complications (516.48 ± 18.6 vs. 394.78 ± 29.9, p = 0.001). AUC TT4 showed significant inverse correlation with inotropic score and borderline inverse correlation with duration of mechanical ventilation. Conclusion: Children undergoing surgery under CPB showed significant fall in thyroid hormones. Because TT4 level is modifiable, prophylactic administration of TT4 for improving outcomes needs to be studied further.  相似文献   
85.
OBJECTIVES AND METHODS: DRF 8417, a novel oxazolidinone, has been evaluated against Gram-positive and fastidious Gram-negative bacteria. In vitro activity of DRF 8417 was determined by broth microdilution method and in vivo efficacy studies were carried out in different murine systemic infection models. RESULTS: DRF 8417 exhibited potent activity against Gram-positive pathogens with MIC(50) and MIC(90) values ranging from 0.06 to 1 mg/L. MICs against Haemophilus influenzae and Moraxella catarrhalis were one to two dilutions lower than those of linezolid. The in vivo efficacy, by oral route, in different susceptible and resistant Gram-positive systemic bacterial infection models ranged from 2.0 to 2.9 mg/kg. CONCLUSIONS: These studies displayed the excellent in vitro and in vivo activity of DRF 8417 against Gram-positive pathogens and lower MICs when compared with linezolid against H. influenzae and M. catarrhalis.  相似文献   
86.
Heteroaryldihydropyrimidines (HAPs) are a new class of antivirals inhibiting production of hepatitis B virus (HBV) virions in tissue culture. Here, we examine the effect of a representative HAP molecule, methyl 4-(2-chloro-4-fluorophenyl)-6-methyl-2-(pyridin-2-yl)-1,4-dihydropyrimidine-5-carboxylate (HAP-1), on the in vitro assembly of HBV capsid protein (Cp). HAP-1 enhances the rate and extent of Cp assembly over a broad concentration range. Aberrant particles, dominated by hexagonal arrays of Cp, were observed from assembly reactions with high HAP-1 concentrations. HAP-1 also led to dissociation of metastable HBV capsids, overcoming a kinetic barrier to dissociation by scavenging Cp and redirecting its assembly into hexamer-rich structures. Thus, HAP drugs act as allosteric effectors that induce an assembly-active state and, at high concentration, preferentially stabilize noncapsid polymers of Cp. HAP compounds may have multiple effects in vivo stemming from inappropriate assembly of Cp. These results show that activating and deregulating virus assembly may be a powerful general approach for antiviral therapeutics.  相似文献   
87.
Journal of Interventional Cardiac Electrophysiology - As AF-associated morbidity and mortality are increasing, there is an acute need for improved surveillance and prevention strategies to reduce...  相似文献   
88.

Purpose

The purpose of this review was to analyze existing literature on the relationship between tooth count and mortality by evaluating the findings in the context of methodological variations. We aimed at addressing the question of whether preserving natural teeth can impact mortality.

Study selection

PubMed, Web of Science and CINAHL databases were systematically searched using various combinations of related and synonymous keywords for “tooth count” and “mortality”. The references of included articles were also evaluated for inclusion. Overall 49 studies found to be eligible were critically evaluated and their key findings were summarized.

Results

Studies were conducted in various continents and differed substantially in regards to their sample size, population, methodology, the definition of the tooth count variable, the confounders as well as the mediators accounted for in the analysis. Follow-up period ranged from 1 to 56 years.

Conclusions

Although high variability in the studies precludes a definite conclusion about the relationship between number of teeth and mortality, the overall finding from this review is that reduced tooth count is associated with higher mortality. However the impact of factors such as smoking, health-care access, baseline co-morbidity and risk profile, dental and periodontal health, the presence of dental prosthesis as well as socio-economic status, in mediating whole or part of the association cannot be overlooked and needs further investigation using more standard methodologies. Any differences in males vs. females, as well as among different age groups, will also need further consideration in the future studies.  相似文献   
89.
90.
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