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   22363篇
  免费   1561篇
  国内免费   102篇
耳鼻咽喉   224篇
儿科学   621篇
妇产科学   488篇
基础医学   2639篇
口腔科学   485篇
临床医学   1706篇
内科学   4747篇
皮肤病学   348篇
神经病学   1219篇
特种医学   587篇
外国民族医学   4篇
外科学   3898篇
综合类   776篇
一般理论   19篇
预防医学   1737篇
眼科学   595篇
药学   2243篇
中国医学   263篇
肿瘤学   1427篇
  2023年   206篇
  2022年   178篇
  2021年   711篇
  2020年   562篇
  2019年   699篇
  2018年   815篇
  2017年   585篇
  2016年   540篇
  2015年   687篇
  2014年   924篇
  2013年   1143篇
  2012年   1694篇
  2011年   1680篇
  2010年   955篇
  2009年   736篇
  2008年   1264篇
  2007年   1191篇
  2006年   1146篇
  2005年   1056篇
  2004年   944篇
  2003年   825篇
  2002年   720篇
  2001年   559篇
  2000年   508篇
  1999年   412篇
  1998年   160篇
  1997年   122篇
  1996年   107篇
  1995年   137篇
  1994年   82篇
  1993年   96篇
  1992年   217篇
  1991年   192篇
  1990年   181篇
  1989年   191篇
  1988年   150篇
  1987年   174篇
  1986年   135篇
  1985年   140篇
  1984年   117篇
  1983年   100篇
  1982年   71篇
  1981年   69篇
  1979年   101篇
  1978年   67篇
  1977年   73篇
  1975年   64篇
  1974年   56篇
  1973年   58篇
  1972年   52篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Anaplastic thyroid carcinoma (ATC) is an aggressive thyroid malignancy with high mortality rate. This malignancy arises in thyroid follicular cells either denovo or with an associated differentiated thyroid carcinoma component. Clinically, it usually presents as a rapidly enlarging mass, pain and locally compressive symptoms. Histopathologic variability and heterogeneity often pose diagnostic challenges, especially in scant and paucicellular specimens. This article describes the clinical, histopathologic and molecular features of ATC and also addresses the associated diagnostic limitations and challenges.  相似文献   
2.
PurposeThe clinical manifestations of rickettsial diseases mimic other endemic infections with similar presentations thus posing a serious challenge to clinicians for their diagnosis. For the diagnosis of rickettsial disease serological tests like Weil Felix, ELISA and IFA are used. There are limited studies that have evaluated different serological tests for the diagnosis of rickettsial diseases. Therefore, the present study was undertaken to evaluate the ELISA and Weil Felix test for the diagnosis of rickettsial diseases prevalent in this region.MethodsSamples from 281 patients clinically suspected of rickettsial diseases were tested for spotted fever group (SFG), typhus group (TG) and scrub typhus group (STG) by Weil Felix, ELISA and IFA was taken as the gold standard. Baseline titers and cut-off ODs were calculated by taking samples from healthy blood donors.ResultsThe sensitivity, specificity, positive and negative predictive value of Weil Felix test ranged from 30% to 44%, 83.46%–97.86%, 9%–77%, 92–96% respectively. The sensitivity and specificity, positive and negative predictive value of ELISA ranged from 80.77% to 96.15%, 96.33%–98.43%, 70.21%–88.64%, 92.89%–99.60% respectively. Maximum cross-reactions were observed between SFG and STG by the Weil Felix test and between STG and TG by ELISA.ConclusionsELISA was found to be sensitive and specific for the diagnosis of rickettsial diseases. It is easy to perform, does not require a technical expert for result interpretation and a large number of samples can be processed at a time.  相似文献   
3.
目的探讨胆总管结石患者采用内镜逆行胰胆管造影术(ERCP)取石后同期开展胆道支架置入术或开展经内镜鼻胆管引流术(ENBD),对于防范并发症的价值。 方法按照前瞻性研究原则,选择2017年4月至2019年1月新疆医科大学第一附属医院收治的338例胆总管结石患者,随机分为支架组(170例)与引流组(168例)。两组患者均行ERCP治疗,其中引流组术后同期开展ENBD,支架组患者术后开展胆道支架置入术,对比两组患者腹痛评分、并发症发生情况及预后。 结果两组患者术后均未合并严重出血、穿孔或病死,结石完全清除率差异无统计学意义。与支架组相比,引流组术中胰腺管插管次数,术后4 h血淀粉酶水平、高淀粉酶血症、急性胰腺炎以及并发症总发生率更高,差异有统计学意义(P<0.05),术后24、48、72 h不同时点腹痛测评分值居更高水平(P<0.05)。 结论对于胆总管结石行ERCP治疗的患者,术后予以ENBD、胆道支架置入术的结石完全清除效果对比无明显差异,但胆道支架置入术更能降低术后并发症风险、缓解腹痛症状,患者获益更多。  相似文献   
4.
The antigenic heterogeneity of Orientia in India is still unknown in many disease endemic areas. The present study aims to characterize the strains of O. tsutsugamushi circulating in Nagaland, Northeast India. Two patients clinically diagnosed with ST and hospitalized in Mon district hospital, Nagaland were identified from whom eschar tissues were collected. Both patients demonstrated antibodies against O. tsutsugamushi along with positive PCR amplification for 56 ?kDa gene. The prototype strain TA763 shared 90.4% homology with the sequences. Both the sequences formed a distinctive cluster demonstrating 100% similarity with strains identified from Thailand, Vietnam, China and southern parts of India.  相似文献   
5.
6.
7.
8.
Background: A transversion missense polymorphism of the TP53 tumor suppressor gene at the codon 72 codes proline instead of arginine causes an altered p53 protein expression and has been found to be associated with an elevated risk of various cancer; especially breast and lung cancer. As the previous case-control studies on the South Asian population have shown controversial results, we performed a meta-analysis to evaluate a precise estimation of the relationship between the TP53 Arg72Pro polymorphism with breast and lung cancer. Methods: A total of 12 related studies on the South Asian population have been included through comprehensive database searching. Six studies were selected for breast cancer meta-analysis involving 950 cases and 882 controls; the other six studies were for lung cancer meta-analysis including 975 cases and 1397 controls. The results have been determined by using the Review Manager (RevMan) 5.3. Additionally, the stability of our analysis was assessed by heterogeneity, publication bias analysis and sensitivity testing. Results: A significantly increased risk of breast cancer was found in Pro allele (Pro vs. Arg), co-dominant model 2 (Pro/Pro vs. Arg/Arg), dominant model (Pro/Pro + Arg/Pro vs. Arg/Arg). In case of lung cancer, significantly increased risk was found in the allele, co-dominant 1, co-dominant 2, co-dominant 3, dominant, and recessive models. No association with other genetic models with breast and lung cancer risk was found in the South Asian population. Conclusions: Our results indicate that TP53 Arg72Pro polymorphism is a risk factor for the development of breast cancer and lung cancer in the South Asian population.  相似文献   
9.
10.
Maternal and Child Health Journal - Floods are one of the most common types of disasters in Bangladesh and lead to direct and indirect impacts on health. The aim of the study was to assess the...  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