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   5944篇
  免费   321篇
  国内免费   38篇
耳鼻咽喉   68篇
儿科学   145篇
妇产科学   152篇
基础医学   730篇
口腔科学   137篇
临床医学   368篇
内科学   1360篇
皮肤病学   61篇
神经病学   357篇
特种医学   205篇
外科学   1105篇
综合类   37篇
一般理论   1篇
预防医学   136篇
眼科学   441篇
药学   429篇
中国医学   11篇
肿瘤学   560篇
  2023年   43篇
  2022年   97篇
  2021年   156篇
  2020年   95篇
  2019年   102篇
  2018年   125篇
  2017年   108篇
  2016年   138篇
  2015年   138篇
  2014年   185篇
  2013年   216篇
  2012年   313篇
  2011年   377篇
  2010年   179篇
  2009年   161篇
  2008年   298篇
  2007年   277篇
  2006年   279篇
  2005年   244篇
  2004年   273篇
  2003年   248篇
  2002年   228篇
  2001年   192篇
  2000年   194篇
  1999年   191篇
  1998年   50篇
  1997年   56篇
  1996年   41篇
  1995年   53篇
  1994年   44篇
  1993年   35篇
  1992年   113篇
  1991年   99篇
  1990年   80篇
  1989年   98篇
  1988年   80篇
  1987年   93篇
  1986年   118篇
  1985年   78篇
  1984年   59篇
  1983年   42篇
  1980年   19篇
  1979年   29篇
  1978年   17篇
  1977年   24篇
  1975年   17篇
  1974年   18篇
  1970年   23篇
  1969年   24篇
  1967年   17篇
排序方式: 共有6303条查询结果,搜索用时 31 毫秒
101.
From December 1996 to June 1998, we performed transurethral surgery of the prostate using a thick loop, VaporTome developed by Circon ACMI on 23 patients with symptomatic benign prostatic hyperplasia (BPH). The mean international prostate symptom score decreased significantly, from 22.6 at baseline to 9.0, 6.5, 4.9 and 5.3 at 1, 3, 6 and 12 months after operation, respectively. The mean quality of life index also decreased significantly, from 5.5 to 1.8, 1.8, 1.4 and 1.2, respectively. The mean peak flow rate increased significantly, from 6.2 preoperatively to 15.8, 17.1, 16.6 and 17.4 ml/sec at 1, 3, 6 and 12 months after operation, respectively. The mean prostate volume decreased significantly, from 66.9 to 24.8, 17.3, 19.0 and 18.2 ml. The mean residual urine decreased significantly, from 167.9 to 11.4, 9.4, 12.8 and 20.4 ml. As for overall efficacy, the rate of excellent and good cases at 1, 3, 6 and 12 months was 80.9, 89.4, 94.7 and 85.8%, respectively. No serious complications were observed. Our clinical results suggest that transurethral surgery for BPH using VaporTome has several potential advantages including high efficacy, minimal morbidity compared with standard transurethral resection of the prostate and lower cost compared with other minimally invasive procedures.  相似文献   
102.
We have experienced thoracoscopic surgery for benign solitary fibrous tumor of the parietal pleura. A 46-year-old woman was admitted to our hospital because of chest abnormal shadow. Under thoracoscopy the tumor that was connected to the parietal pleura with a wide pedicle was completely resected with combined parietal resection of the pleura. Pathological diagnosis was a benign solitary fibrous tumor developed from the connective tissues under the parietal pleura. Thoracoscopic surgery is well indicated for a solitary fibrous tumor and wide excision of the tumor with combined resection of the pleura is important to prevent a local recurrence.  相似文献   
103.
The water monitor lizard (Varanus salvator macromaculatus (VSA), Platynota) has a chromosome number of 2n?=?40: its karyotype consists of 16 macrochromosomes and 24 microchromosomes. To delineate the process of karyotype evolution in V. salvator macromaculatus, we constructed a cytogenetic map with 86 functional genes and compared it with those of the butterfly lizard (Leiolepis reevesii rubritaeniata (LRE); 2n?=?36) and Japanese four-striped rat snake (Elaphe quadrivirgata (EQU); 2n?=?36), members of the Toxicofera clade. The syntenies and gene orders of macrochromosomes were highly conserved between these species except for several chromosomal rearrangements: eight pairs of VSA macrochromosomes and/or chromosome arms exhibited homology with six pairs of LRE macrochromosomes and eight pairs of EQU macrochromosomes. Furthermore, the genes mapped to microchromosomes of three species were all located on chicken microchromosomes or chromosome 4p. No reciprocal translocations were found in the species, and their karyotypic differences were caused by: low frequencies of interchromosomal rearrangements, such as tandem fusions, or centric fissions/fusions between macrochromosomes and between macro- and microchromosomes; and intrachromosomal rearrangements, such as paracentric inversions or centromere repositioning. The chromosomal rearrangements that occurred in macrochromosomes of the Varanus lineage were also identified through comparative cytogenetic mapping of V. salvator macromaculatus and V. exanthematicus. Morphologic differences in chromosomes 6–8 between the two species could have resulted from pericentric inversion or centromere repositioning.  相似文献   
104.
We present a set of nuclear DNA SNPs useful for discriminating native Lake Biwa and introduced ??Eurasian?? strains of common carp, and further, for detecting their hybridization. Such SNPs were searched around short tandem repeat (STR) regions to be used later as HapSTR markers. A total of 62 microsatellite locus were screened with PCR and direct sequencing. The resultant nucleotide sequences from typical Lake Biwa (n?=?30) and ??Eurasian?? (n?=?24) specimens indicated that a total of 21 SNPs distributed across 7 loci would be useful for the above-mentioned purpose. All of the SNPs can be genotyped by direct sequencing, simultaneously with STR polymorphisms.  相似文献   
105.
The purpose of this study is to determine the incidence, clinical characteristics and risk factors of postradiation pelvic insufficiency fracture (PIF) in women with uterine cervical cancer. We reviewed the medical records of 126 patients who received definitive radiotherapy (RT) for uterine cervical cancer between 2003 and 2009 at our institution. Among them, 99 patients who underwent at least one computed tomography (CT) or magnetic resonance imaging of the pelvis during their follow-up at more than 6 months were included in this analysis. The relationship between the incidence of PIF and several patient- and treatment-related factors was analyzed. The median follow-up period was 21 months. Of the 126 patients, 33 (with a total of 50 lesions) were diagnosed with PIF. The 2-year cumulative incidence was 32%. Univariate analysis showed that age ≥70 years (P= 0.0010), postmenopausal state (P = 0.0013), and lower CT density of bone and bone marrow (P= 0.020) significantly related to PIF. In a multivariate analysis, of the 59 patients whose CT densities were evaluable, lower CT density was the only significant factor associated with PIF (P = 0.0026). In conclusion, postradiation PIFs were detected in a considerable number of patients after definitive RT for cervical cancer. Predisposing factors were older age, postmenopausal state, and decreased density of bone and bone marrow on CT.  相似文献   
106.

Background and Aim

Differential diagnosis of localized gallbladder lesions is challenging. The aim of the present study was to evaluate the utility of contrast‐enhanced harmonic endoscopic ultrasonography (CH‐EUS) for diagnosis of localized gallbladder lesions.

Methods

One hundred and twenty‐five patients with localized gallbladder lesions were evaluated by CH‐EUS between March 2007 and February 2014. This was a single‐center retrospective study. Utilities of fundamental B‐mode EUS (FB‐EUS) and CH‐EUS in the differentiation of gallbladder lesions and sludge plug were initially compared. Thereafter, these two examinations were compared with respect to their accuracy in the diagnosis of malignant lesions. Five reviewers blinded to the clinicopathological results evaluated microcirculation patterns in the vascular and perfusion images.

Results

In the differentiation between gallbladder lesions and sludge plug, FB‐EUS had a sensitivity, specificity, and accuracy of 82%, 100%, and 95%, respectively, whereas CH‐EUS had a sensitivity, specificity, and accuracy of 100%, 99%, and 99%, respectively. FB‐EUS‐based diagnosis of carcinomas based on tumor size and/or shape had a sensitivity, specificity, and accuracy of 61–87%, 71–88%, and 74–86%, respectively. Additional information regarding irregular vessel patterns in the vascular image and/or heterogeneous enhancement in the perfusion image on CH‐EUS increased the sensitivity, specificity, and accuracy for the diagnosis of carcinomas to 90%, 98%, and 96%, respectively. There was a significant difference between FB‐EUS and CH‐EUS in terms of carcinoma diagnosis.

Conclusion

CH‐EUS was useful for the evaluation of localized gallbladder lesions.  相似文献   
107.
108.
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