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   8497篇
  免费   433篇
  国内免费   160篇
耳鼻咽喉   87篇
儿科学   129篇
妇产科学   137篇
基础医学   1315篇
口腔科学   201篇
临床医学   709篇
内科学   1630篇
皮肤病学   242篇
神经病学   509篇
特种医学   722篇
外科学   971篇
综合类   53篇
预防医学   265篇
眼科学   103篇
药学   1037篇
中国医学   160篇
肿瘤学   820篇
  2024年   4篇
  2023年   48篇
  2022年   174篇
  2021年   285篇
  2020年   123篇
  2019年   158篇
  2018年   235篇
  2017年   164篇
  2016年   281篇
  2015年   434篇
  2014年   423篇
  2013年   513篇
  2012年   818篇
  2011年   724篇
  2010年   456篇
  2009年   383篇
  2008年   463篇
  2007年   410篇
  2006年   355篇
  2005年   389篇
  2004年   314篇
  2003年   239篇
  2002年   198篇
  2001年   122篇
  2000年   123篇
  1999年   94篇
  1998年   119篇
  1997年   120篇
  1996年   132篇
  1995年   98篇
  1994年   103篇
  1993年   82篇
  1992年   35篇
  1991年   55篇
  1990年   40篇
  1989年   42篇
  1988年   49篇
  1987年   36篇
  1986年   42篇
  1985年   39篇
  1984年   16篇
  1983年   22篇
  1982年   21篇
  1981年   25篇
  1980年   18篇
  1979年   7篇
  1978年   10篇
  1977年   14篇
  1976年   15篇
  1975年   8篇
排序方式: 共有9090条查询结果,搜索用时 15 毫秒
991.
992.
993.
Cation‐specific epithelial receptors on the tongue have been well demonstrated. However, active regions along the nucleus of the solitary tract (NST) for cations Na+, K+, NH4+ are still unclear, even though the best responses of NST neurons to taste stimuli vary depending on the cell. In the present study, the spatial distribution patterns of cation‐specific active regions in the NST are investigated. The tongues of urethane‐anesthetized Sprague‐Dawley rats (n = 25) were stimulated with artificial saliva (control), 0.5 M NaCl, 1.0 M NaCl, 0.5 M KCl, and 0.3 M NH4Cl. Then, the three‐dimensional positions of c‐Fos‐like‐immunoreactive (cFLI) cells in the NST were generated. The spatial distributions of cFLI cells in the NST were compared among five taste stimulations. cFLI cells were observed throughout the NST, irrespective of the stimulus; however, the intermediate‐medial central regions of the NST had higher numbers of cFLI cells than the other regions in all taste stimulations. Analysis of images revealed that the activated regions in the NST differed significantly depending on the cations. The intermediate‐dorsal‐central region and the caudal‐ventral region were activated by a 0.5 M concentration of sodium, the rostral‐ventral region and the intermediate‐dorsal/ventral region were activated by a 1.0 M concentration of sodium, the intermediate‐dorsal/ventral region was activated by potassium ions, and the rostral‐ventral region and the intermediate‐ventral central region were activated by ammonium ions. These results suggest that the responses of NST cells to cation salt ions are regulated differentially. © 2014 Wiley Periodicals, Inc.  相似文献   
994.
995.
996.
ObjectivesVascular tinnitus is the most common form of pulsatile tinnitus, particularly when the tinnitus corresponds with the pulse of patients. In this study, we reviewed the 10-year clinical data on vascular tinnitus of our tinnitus clinic to investigate the frequency of the underlying etiologies, to introduce a diagnostic protocol, and to evaluate the treatment outcomes.MethodsWe retrospectively collected the data of 57 patients who were diagnosed as vascular tinnitus between April 2001 and December 2011. Careful history taking, otoscopy, thorough physical examinations, audiometry, laboratory tests, as well as radiologic examinations were performed according to our diagnostic protocol to find the origin of pulsatile tinnitus. Treatment options were individualized based on the specific etiology, and the outcomes were assessed using patient''s subjective reports at the follow-up interviews.ResultsHigh jugular bulb was the most common cause (47.4%) of vascular tinnitus, and venous hum was the next (17.5%). Dural arteriovenous fistula, intracranial aneurysm, atherosclerotic carotid artery disease, and hypertension were less common causes. Vascular tinnitus was alleviated in most patients after the appropriate treatment: surgical intervention, tinnitus retraining therapy, reassurance, and medications.ConclusionVascular tinnitus can be successfully diagnosed by the regular use of the suggested protocol. Many patients with vascular tinnitus have treatable underlying etiologies. Treatment of those etiologies or at least counseling about the tinnitus itself can benefit the patients with troublesome vascular tinnitus.  相似文献   
997.
Cyclin D1 is frequently overexpressed in esophageal squamous cell carcinoma (ESCC) and is considered a key driver of this disease. Mutations in FBXO4, F-box specificity factor that directs SCF-mediated ubiquitylation of cyclin D1, occur in ESCC with concurrent overexpression of cyclin D1 suggesting a potential tumor suppressor role for FBXO4. To evaluate the contribution of FBXO4-dependent regulation cyclin D1 in esophageal squamous cell homeostasis, we exposed FBXO4 knockout mice to N-nitrosomethylbenzylamine (NMBA), an esophageal carcinogen. Our results revealed that loss of FBXO4 function facilitates NMBA induced papillomas in FBXO4 het (+/−) and null (−/−) mice both by numbers and sizes 11 months after single dose NMBA treatment at 2mg/kg by gavage when compared to that in wt (+/+) mice (P < 0.01). No significant difference was noted between heterozygous or nullizygous mice consistent with previous work. To assess cyclin D1/CDK4 dependence, mice were treated with the CDK4/6 specific inhibitor, PD0332991, for 4 weeks. PD0332991 treatment (150mg/kg daily), reduced tumor size and tumor number. Collectively, our data support a role for FBXO4 as a suppressor of esophageal tumorigenesis.  相似文献   
998.
ObjectiveThis study reports our initial experience of robotic high para-aortic lymph node dissection (PALND) with high port placement using same port for pelvic surgery in cervical and endometrial cancer patients.MethodsBetween July 2013 and January 2014, we performed robotic high PALND up to the left renal vein during staging surgeries. With high port placement and same port usage for pelvic surgery, high PALND was successfully performed without repositioning the robotic column. All data were registered consecutively and analyzed retrospectively.ResultsAll patients successfully underwent robotic high PALND, followed by hysterectomy and pelvic lymph node dissection. Median age was 45 years (range, 39 to 51 years) and median body mass index was 22 kg/m2 (range, 19.3 to 23.1 kg/m2). Median operative time for right PALND and left PALND was 37 minutes (range, 22 to 65 minutes) and 44 minutes (range, 36 to 50 minutes), respectively. Median number of right and left para-aortic lymph node by pathologic report was 12 (range, 8 to 15) and 13 (range, 5 to 26).ConclusionWith high port placement and one assistant port, robotic high PALND with the same port used in pelvic surgery is feasible to non-obese patients.  相似文献   
999.
Intratumoral heterogeneity of HER2 expression is common in gastric cancers and pose a challenge for identifying patients who would benefit from anti-HER2 therapy. The aim of this study is to compare HER2 expression in biopsy and resection specimens of gastric carcinoma by immunohistochemistry (IHC) and to find the ideal number of biopsy tumor fragments that can accurately predict HER2 overexpression in the corresponding surgically resected specimen. The HER2 IHC results of 702 paired biopsy and resection specimens of gastric cancer were compared.The mean number of biopsy fragments among all cases was 4.3 (range 1–11). HER2 was positive in 130 (18.5%) endoscopic biopsies and in 102 (14.5%) gastrectomy specimens. Intratumoral heterogeneity of HER2 was found in 80 (61.5%) biopsies and 70 (68.6%) resection specimens. Out of the 70 surgical specimens with intratumoral heterogeneity, 24 (34.3%) of the corresponding biopsies were categorized as negative (positive conversion). In the 86 (12.3%) discrepant cases, negative conversion was observed in 57 (66.3%) cases and positive conversion in 29 (33.7%). The fragment numbers were significantly correlated with the discrepancy of results and positive predictability (P = 0.0315 and P = 0.0052). ROC curve analysis and positive predictability showed that 4 fragments should be obtained to minimize the differences in HER2 scores between biopsy and resection specimen.In gastric carcinomas with discrepant HER2 results between biopsy and surgical resection specimens, intratumoral heterogeneity is common with most of them showing positive conversion. To predict HER2 status precisely, at least 4 biopsy fragments containing tumor cells are required.  相似文献   
1000.

Objective

To discuss the feasibility of single-site robotic surgery for benign gynecologic tumors and early stage gynecologic cancers.

Methods

In this single institution, prospective analysis, we analyzed six patients who had undergone single-site robotic surgery between December 2013 and August 2014. Surgery was performed using the da Vinci Si Surgical System. Patient characteristics and surgical outcomes were analyzed.

Results

Single-site robotic surgery was performed successfully in all six cases. The median patient age was 48 years, and the median body mass index was 25.5 kg/m2 (range, 22 to 33 kg/m2). The median total operative time was 211 minutes, and the median duration of intracorporeal vaginal cuff suturing was 32 minutes (range, 22 to 47 minutes). The median duration of pelvic lymph node dissection was 31 minutes on one side and 27 minutes on the other side. Patients'' postoperative courses were uneventful. The median postoperative hospital stay was 4 days. No postoperative complications occurred.

Conclusion

When used to treat benign gynecologic tumors and early stage gynecologic cancers, the single-site da Vinci robotic surgery is feasible, safe, and produces favorable surgical outcomes.  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