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   1137篇
  免费   72篇
  国内免费   8篇
耳鼻咽喉   7篇
儿科学   24篇
妇产科学   18篇
基础医学   257篇
口腔科学   16篇
临床医学   114篇
内科学   347篇
皮肤病学   20篇
神经病学   63篇
特种医学   22篇
外科学   111篇
综合类   5篇
预防医学   38篇
眼科学   4篇
药学   96篇
中国医学   4篇
肿瘤学   71篇
  2023年   5篇
  2022年   25篇
  2021年   34篇
  2020年   24篇
  2019年   22篇
  2018年   28篇
  2017年   20篇
  2016年   25篇
  2015年   28篇
  2014年   39篇
  2013年   55篇
  2012年   86篇
  2011年   97篇
  2010年   66篇
  2009年   48篇
  2008年   76篇
  2007年   90篇
  2006年   81篇
  2005年   64篇
  2004年   70篇
  2003年   57篇
  2002年   54篇
  2001年   7篇
  2000年   7篇
  1999年   6篇
  1998年   8篇
  1997年   8篇
  1996年   5篇
  1995年   11篇
  1994年   9篇
  1993年   8篇
  1992年   4篇
  1988年   4篇
  1987年   2篇
  1983年   4篇
  1982年   6篇
  1981年   3篇
  1980年   4篇
  1979年   6篇
  1977年   4篇
  1975年   2篇
  1974年   2篇
  1973年   1篇
  1971年   1篇
  1968年   1篇
  1967年   1篇
  1966年   2篇
  1965年   2篇
  1963年   1篇
  1942年   1篇
排序方式: 共有1217条查询结果,搜索用时 187 毫秒
101.
J Oral Pathol Med (2010) 39 : 115–120
Background:  Podoplanin expression was described in mouse tooth germ and apical bud cells. The aim of this study was to analyse the podoplanin expression of human tooth germ tissues, adult teeth and odontogenic lesions immunohistochemically.
Study Design:  Nine human tooth germ biopsies and seven healthy permanent teeth extracted for orthodontic reasons were examined. Anti-podoplanin (D2-40) reactivity was investigated immunohistochemically. Five well-defined cystic odontogenic lesions (10 radicular cysts, 10 follicular cysts, three keratocystic odontogenic tumours, five ameloblastomas, and two adenomatoid odontogenic tumours) were analysed simultaneously.
Results:  Podoplanin expression was detected in the majority of epithelial and ecto-mesenchymal cells of human tooth germ tissues, odontoblasts and superficial dental pulp fibroblasts of permanent teeth. Cystic odontogenic lesions revealed positive reactions predominantly at the invasion front edge within basal epithelial layers.
Conclusion:  Podoplanin appears to be involved in the orthologic and pathologic processes of the formation of elongated cell extensions and odontoblastic fibers, in the epithelial–mesenchymal transition and local invasion during tooth germ development as well as in both reactive and neoplastic odontogenic cystic lesions.  相似文献   
102.
Ductus venosus waveform analysis has become increasingly affected by technical errors; however, these errors could be avoided if more attention was paid during sampling and analysis. The most common misevaluations include incorrect tracing, under- or overestimation of the peak systolic velocity, overestimation of the end-diastolic velocity, and, as a consequence, incorrect calculation of the pulsatility index facilitated either by human or software error. This article proposes practical suggestions to avoid technical errors in ductus venosus waveform analysis.  相似文献   
103.
104.
OBJECTIVE: To determine whether the efficacy of diacerein persists at 2 months after the end of a 3-month treatment period, compared with placebo, in patients with painful knee osteoarthritis (OA). METHODS: After a 1-week nonsteroidal antiinflammatory drug washout period, patients received either diacerein or placebo for 3 months, followed by an off-treatment period of 3 months to determine the carryover effects of the drug. Although patients were followed up through month 6, the primary efficacy end point was the percent change from baseline in pain (Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC] A) at month 5 (i.e., 2 months after the end of treatment) compared with placebo. The co-primary efficacy end point was the percent change from baseline in the total WOMAC score, also at month 5 versus placebo. RESULTS: Two hundred three patients were screened, and 168 patients with painful knee OA were randomized. One hundred sixty-five patients were analyzed in an intent-to-treat analysis. At month 5, diacerein showed statistically significant superiority versus placebo as assessed with both the WOMAC A (P < 0.0001) and the total WOMAC (P < 0.0001), demonstrating the carryover effect of the drug. This superiority was already evident from month 2 for pain (P = 0.001) and month 1 for total WOMAC (P = 0.0021). Diacerein was safe and well tolerated. No serious or previously undocumented adverse events were observed during the study. CONCLUSION: This is the first published study of a symptomatic slow-acting OA drug in which the time of assessment of the primary outcome end points was 2 months after the end of a 3-month treatment period. The results show that diacerein is safe and effective for the treatment of knee OA and has a long carryover effect.  相似文献   
105.
The TEL/AML1 fusion gene results from the most frequent t(12;21)(p13;q22) translocation in childhood acute lymphoblastic leukemia (ALL). Its contribution to transformation is largely unknown, in particular with respect to survival and apoptosis. We therefore silenced TEL/AML1 expression in leukemic REH cells by RNA inhibition, which eventually led to programmed cell death. Microarray and 2D gel electrophoresis data demonstrated a differential regulation of heat-shock proteins (HSPs), among them HSP90, as well as of its client, survivin. Consistent with these findings, ectopic expression of TEL/AML1 in Ba/F3 cells increased protein levels of HSP90 and survivin and conferred resistance to apoptotic stimuli. Our data suggest that TEL/AML1 not only contributes to leukemogenesis by affecting an antiapoptotic network but also seems to be indispensable for maintaining the malignant phenotype. The functional relationship between TEL/AML1, HSP90, and survivin provides the rational for targeted therapy, be it the fusion gene or the latter 2 proteins.  相似文献   
106.
Clinical data from 50 mentally retarded (MR) males in nine X-linked MR families, syndromic and non-specific, with mutations (duplication, expansion, missense, and deletion mutations) in the Aristaless related homeobox gene, ARX, were analysed. Seizures were observed with all mutations and occurred in 29 patients, including one family with a novel myoclonic epilepsy syndrome associated with the missense mutation. Seventeen patients had infantile spasms. Other phenotypes included mild to moderate MR alone, or with combinations of dystonia, ataxia or autism. These data suggest that mutations in the ARX gene are important causes of MR, often associated with diverse neurological manifestations.  相似文献   
107.
We reported the case of a boy who fled from Chechnya to Belgium. He was diagnosed with a human immune deficiency virus (HIV)/Visceral leishmaniasis (VL) coinfection. In both countries, the prevalence of HIV-infected children is low and VL is not endemic. Migration of people results in confrontation with diseases that are not frequent in the countries of destination and becomes a challenge for pediatricians.  相似文献   
108.
To synthesize potent antagonists of the mu-opioid receptor, we prepared a series of endomorphin-1 and endomorphin-2 analogues with 3-(1-naphthyl)-d-alanine (d-1-Nal) or 3-(2-naphthyl)-d-alanine (d-2-Nal) in position 4. Some of these analogues displayed weak antagonist properties. We tried to strengthen these properties by introducing the structurally modified tyrosine residue 2,6-dimethyltyrosine (Dmt) in place of Tyr1. Among the synthesized compounds, [Dmt1, d-2-Nal4]endomorphin-1, designated antanal-1, and [Dmt1, d-2-Nal4]endomorphin-2, designated antanal-2, turned out to be highly potent and selective mu-opioid receptor antagonists, as judged on the basis of two functional assays, the receptor binding assay and the hot plate test of analgesia. Interestingly, another analogue of this series, [Dmt1, d-1-Nal4]endomorphin-1, turned out to be a moderately potent mixed mu-agonist/delta-antagonist.  相似文献   
109.
BACKGROUND AND OBJECTIVES: It was proposed that occult pancreaticobiliary reflux (OPBR) was associated with precancerous mucosal changes in the gallbladder, hence the importance of this disorder. There are no published reports investigating the incidence of OPBR in patients operated on for the entire spectrum of benign gallbladder diseases and gallbladder cancer. Our aim was to determine the incidence of OPBR and measure the levels of active pancreatic enzymes (amylase and lipase) in gallbladder bile of patients undergoing cholecystectomy for benign and malignant gallbladder diseases. METHODS: One hundred eight patients with normal pancreaticobiliary junction evidenced by operative cholangiography were included in the study. RESULTS: According to gallbladder bile amylase and lipase levels, 84.2% and 89% patients respectively had OPBR. OPBR was present in all gallbladder cancer patients; in these patients the biliary levels of amylase and lipase were significantly higher than the levels found in patients with benign gallbladder pathology (P < 0.0001). CONCLUSIONS: OPBR could lead to inflammatory changes of the biliary epithelium and progress towards the development of precancerous mucosal changes and gallbladder cancer. The reason why such high levels of pancreatic enzymes are regurgitated into the biliary tree of patients with gallbladder cancer should be clarified.  相似文献   
110.
The definitive diagnosis of α-thalassemia involves detection of a deletion of one or more α-globin that encode the α-chains of Hb (hemoglobin). To determine whether DNA analysis is indicated, screening tests such as mean corpuscular volume (MCV) and Hb typing are employed. α-Thalassemia often correlates with normal or low HbA2 values. Zinc protoporphyrin (ZPP) is usually high in ferropenic anemia or lead-poisoning and is normal or slightly raised in ß-thalassemia. Therefore, ZPP is currently used as a marker to discriminate between ferropenic anemia and β-thalassemia. We investigated the diagnostic potential of ZPP < 150 μmol/mol heme in a screening strategy for α-thalassemia. We measured ZPP and performed DNA analysis for detecting the seven most prevalent α-thalassemia deletions, namely, α3.7, SEA, α20.5, α4.2, MED, FIL, and THAI, in the blood samples of 200 patients with MCV < 70 fL and HbA2 ≤ 3.5%. Deletions were detected in 9% subjects in the ZPP ≥ 150 group (n = 175) and 56% subjects in the ZPP < 150 group (n = 29); this difference was statistically significant (chi-square test, P < 0.001). We conclude that ZPP < 150 μmol/mol heme can be used in a new screening strategy for α-thalassemia.  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