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   5761篇
  免费   312篇
  国内免费   46篇
耳鼻咽喉   54篇
儿科学   190篇
妇产科学   75篇
基础医学   854篇
口腔科学   130篇
临床医学   425篇
内科学   1406篇
皮肤病学   146篇
神经病学   546篇
特种医学   151篇
外科学   464篇
综合类   38篇
一般理论   1篇
预防医学   271篇
眼科学   237篇
药学   434篇
中国医学   14篇
肿瘤学   683篇
  2023年   41篇
  2022年   82篇
  2021年   122篇
  2020年   74篇
  2019年   124篇
  2018年   148篇
  2017年   121篇
  2016年   154篇
  2015年   149篇
  2014年   196篇
  2013年   240篇
  2012年   334篇
  2011年   413篇
  2010年   223篇
  2009年   205篇
  2008年   376篇
  2007年   406篇
  2006年   350篇
  2005年   413篇
  2004年   393篇
  2003年   373篇
  2002年   305篇
  2001年   53篇
  2000年   45篇
  1999年   75篇
  1998年   73篇
  1997年   62篇
  1996年   72篇
  1995年   44篇
  1994年   44篇
  1993年   45篇
  1992年   32篇
  1991年   31篇
  1990年   26篇
  1989年   22篇
  1988年   25篇
  1987年   21篇
  1986年   11篇
  1985年   15篇
  1984年   16篇
  1983年   22篇
  1982年   16篇
  1981年   13篇
  1980年   13篇
  1979年   13篇
  1978年   12篇
  1977年   7篇
  1976年   11篇
  1975年   5篇
  1974年   9篇
排序方式: 共有6119条查询结果,搜索用时 15 毫秒
101.
102.
103.
104.
In skeletal Class II patients with a high mandibular plane angle, it is well known that posterior rotation of the mandible often occurs during treatment using a preadjusted edgewise appliance. In this case, posterior rotation of the mandible with increased overjet occurred after the buccal inclination of the mandibular 2nd molars. This case report describes a Class II high angle case for which titanium screws were added as an absolute anchorage to improve the posterior rotation of the mandible. To correct the posterior rotation of the mandible, mandibular molars were intruded and the mandibular arch was mesially moved using titanium screws. The treatment results show that titanium screws were useful for improving the posterior rotation of the mandible during treatment using a preadjusted edgewise appliance.  相似文献   
105.
Background/Aims: To investigate differences in clinicopathological features between proximal and distal pT3 colon cancers and to determine whether the depth of the cancer invasion beyond the muscularis propria (DBM) serves as an objective indicator of the depth of tumor invasion in proximal colon cancer and in distal colon cancer. Methodology: A total of 207 patients who underwent surgery for proximal and distal pT3 colon cancer between 1996 and 2001 were included in the analysis. Results: No differences were noted between proximal and distal cancers in lymph node metastasis, distant metastasis, lymphatic/venous invasion, histological type and curability of surgical resection, although proximal cancer patients were significantly older. High-grade malignancy appeared to be more commonly noted in the proximal colon cancer cases but there was no significant difference in prognosis between proximal and distal cancer patients. Conclusions: Regarding the correlation between DBM and prognosis, there was a significant decrease in the 5-year survival rate in patients with proximal lesions of DBM 3000μm or more, and patients with distal lesions of DBM 5000μm or more. DBM is thus an objective indicator of depth of tumor invasion for both proximal and distal lesions, a prognostic factor and a guide to determining whether postoperative adjuvant chemotherapy is indicated for pT3 colon cancer cases.  相似文献   
106.
107.
ObjectiveA mixture of ciprofloxacin, metronidazole, and minocycline (3Mix) has been reported to be effective against oral bacteria from carious and endodontic lesions in vitro and in vivo. The objective of this study was to establish an animal model using mice for the application of 3Mix following intentionally delayed tooth replantation and to investigate the effects of 3Mix on the healing process of dental pulp and periodontal tissues.MethodsUpper first molars of ICR mice were extracted, immersed in 3Mix solution at different concentrations for 5–60 min with or without the use of a transfer solution (phosphate buffer solution (PBS)), in addition to transfer solution alone, and subsequently repositioned in the sockets. Immunohistochemistry for nestin and Ki-67, histochemistry for TRAP, and TUNEL assay were performed to assess pulpal healing during days 7–21.ResultsIncreased apoptosis was observed in the PBS group at week 1, followed by cell proliferation at week 2, and tertiary dentin and/or bone-like tissue formation at week 3. In contrast, nestin-positive, newly differentiated, odontoblast-like cells began to align along the pulp–dentin border following the appearance of Ki-67- and TUNEL-positive cells during weeks 1–2 in the 3Mix groups, suggesting that pulpal healing was accelerated. Severe root ankylosis was observed exclusively in the 3Mix groups. Rinsing with PBS before replantation partially rescued the viability of the periodontal ligament, but pulpal healing was delayed.ConclusionsThe application of 3Mix promotes pulpal regeneration of intentionally delayed replanted teeth; however, its use may induce severe damage to periodontal tissues.  相似文献   
108.
We developed an enrichment medium for use with the loop-mediated isothermal amplification (LAMP) assay (enrichment media + LAMP assay) to quickly increase a very small number of Vibrio parahaemolyticus cells to the detection limit of the assay. Thirty-nine different enrichment media were prepared based on evaluating 12 potential ingredients. From our assessment of the 39 media, enrichment medium #36, which contained 2% sodium chloride, 1% proteose peptone no. 2, 0.1% trehalose, 0.5% α-ketoglutaric acid, 0.25% pyruvic acid, and 0.5% yeast extract (pH 8.6), was found to be most effective at enhancing the proliferation of V. parahaemolyticus during incubation for 3 h at 40oC. We compared the detection limits of the LAMP assay, the enrichment medium #36 + LAMP assay, and the cultivation method using bacterial cell and spiked shrimp sample tests. The detection limits of the LAMP assay, the medium #36 + LAMP assay, and the cultivation method were 10(3), 10(0)-10(-1), and 10(-1) CFU ml(-1), respectively. Enrichment medium #36 promoted a 10(3)- to 10(4)-fold increase in the bacterial population, and the detection limit of the enrichment media + LAMP assay was the same as that of the cultivation method.  相似文献   
109.
110.
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