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   471篇
  免费   33篇
  国内免费   4篇
耳鼻咽喉   2篇
儿科学   12篇
妇产科学   13篇
基础医学   77篇
口腔科学   12篇
临床医学   29篇
内科学   93篇
皮肤病学   23篇
神经病学   62篇
特种医学   23篇
外科学   51篇
综合类   5篇
预防医学   23篇
眼科学   1篇
药学   51篇
中国医学   5篇
肿瘤学   26篇
  2023年   4篇
  2022年   6篇
  2021年   17篇
  2020年   17篇
  2019年   14篇
  2018年   17篇
  2017年   11篇
  2016年   20篇
  2015年   16篇
  2014年   22篇
  2013年   27篇
  2012年   30篇
  2011年   26篇
  2010年   18篇
  2009年   18篇
  2008年   31篇
  2007年   21篇
  2006年   28篇
  2005年   33篇
  2004年   21篇
  2003年   17篇
  2002年   10篇
  2001年   13篇
  2000年   8篇
  1999年   10篇
  1998年   3篇
  1997年   5篇
  1996年   1篇
  1995年   4篇
  1993年   2篇
  1992年   3篇
  1991年   5篇
  1990年   4篇
  1989年   6篇
  1988年   3篇
  1987年   3篇
  1986年   3篇
  1985年   3篇
  1984年   1篇
  1983年   2篇
  1980年   1篇
  1979年   1篇
  1977年   1篇
  1974年   1篇
  1969年   1篇
排序方式: 共有508条查询结果,搜索用时 15 毫秒
1.
2.
Serosorting (i.e., engaging in unprotected sex with partners known to be of the same serostatus) can be a difficult process for men who have sex with men (MSM) who frequently make assumptions about their partners' serostatus. This process can be further complicated by a partner's dishonesty as well as other individual and contextual factors. The present study specifically examined how assumptions of serostatus made about unknown serostatus partners impact on the sexual behavior of 110 alcohol-abusing HIV-positive MSM. Although previous research has shown that HIV-positive MSM are more likely to serosort with other known HIV-positive men than with known HIV-negative men, our data suggest that unprotected sex behavior may not be specifically driven by whether or not they made assumptions of seroconcordance or serodiscordance. The types of assumptions these HIV-positive MSM made about their unknown status sexual partners and the basis for such assumptions were also examined. Owing to the ambiguities involved in assumptions of a partner's serostatus in sexual encounters, the 'unknown status' partner category is analytically distinct from 'known status' categories, and needs to be more fully explored because of its impact on perceived serosorting, rather than actual serosorting, among HIV-positive men.  相似文献   
3.
OBJECTIVE: The American Psychiatric Association's DSM-IV Work Group on Late Luteal Phase Dysphoric Disorder (LLPDD) reanalyzed existing data from prospective, daily symptom ratings to evaluate the DSM-III-R criteria for LLPDD. The objectives were to 1) evaluate the individual symptoms presently required for the diagnosis and other symptoms, 2) determine the proportion of treatment-seeking women who meet the LLPDD criteria, and 3) explore the association between LLPDD and other mental disorders. METHOD: Data from over 1,000 women seeking evaluation for premenstrual complaints at five U.S. sites were examined. The data from 670 of these women were sufficiently complete to warrant evaluation by four different methods of assessing symptom change. RESULTS: Depending on the assessment method used, 14% to 45% of the women met the criteria for LLPDD. The current DSM-III-R symptoms were classified as positive for 7% to 54% of the women. Each of these symptoms was significantly more common among women with LLPDD regardless of the assessment method used. Five symptoms not presently included were also significantly more common. Women who had had mental disorders in the past, but not present, showed a significantly greater, but very small, relative risk of LLPDD. CONCLUSIONS: The variability in the frequency of LLPDD diagnosis according to method of assessing symptom change underscores the need for a uniform assessment method. The five additional symptoms with frequencies comparable to those of the DSM-III-R symptoms should be studied further for possible inclusion in the criteria.  相似文献   
4.
Premenstrual syndrome and locus of control   总被引:1,自引:0,他引:1  
Seventy-six women completed a three-month prospective evaluation for premenstrual syndrome (PMS). As a part of the evaluation, they completed Rotter's Locus of Control (LOC) form in the follicular phase and premenstrually. It was found that the LOC scores of women meeting criteria for PMS rose significantly (became more "external") premenstrually, while scores of women without PMS did not show significant change. In addition, the premenstrual LOC scores of women meeting criteria for PMS were significantly higher than were scores of the non-PMS women. The results are consistent with the idea that cycle related changes in self-perception occur in women demonstrating PMS symptomatology.  相似文献   
5.
Late luteal phase dysphoric disorder and DSM-III-R   总被引:1,自引:0,他引:1  
Text and diagnostic criteria for a new category, late luteal phase dysphoric disorder, appear in appendix A of DSM-III-R: "Proposed Diagnostic Categories Needing Further Study." The inclusion of this category in the manual was perhaps the most controversial aspect of the revision of DSM-III. In this paper the authors describe the work of the advisory committee that first proposed the category, the rationale for the category's inclusion in the manual, and the many issues that were the focus of heated debates.  相似文献   
6.
7.
Reimplantation of the supra‐aortic vessels can be challenging with Thoraflex Hybrid. A device modification made the vessel lengths more appropriate and the position of the neo‐vessels in the chest avoided malpositioning and kinking and facilitated sternum closure; this may improve operating times as well as allowing complete and continuous cerebral trivascular perfusion and corrects positioning of the intrathoracic vessels.  相似文献   
8.
Vitrification, an ultra-rapid cooling technique, offers a new perspective in attempts to develop an optimal cryopreservation procedure for human oocytes and embryos. To further evaluate this method for human oocytes, 796 mature oocytes (metaphase II) were collected from 120 volunteers. Since Italian legislation allows the fertilization of a maximum of only three oocytes per woman, there were 463 supernumerary oocytes; instead of being discarded, they were vitrified. When, in subsequent cycles, these oocytes were utilized, 328 out of 330 (99.4%) oocytes survived the warming procedure. The fertilization rate, pregnancy rate and implantation rate per embryo were 92.9, 32.5 and 13.2% respectively. Thus, as already reported in the literature, the vitrification procedure seems to be highly effective, safe (since healthy babies have been born) and easy to apply. In situations where embryo cryopreservation is not permitted (as in Italy), there is now good indication for routine application of the method, once further standardization is achieved.  相似文献   
9.
10.
HYPOTHESIS: Radiofrequency thermal ablation (RFA) can be performed safely and effectively to control local disease in patients with advanced, unresectable liver tumors. DESIGN, SETTING, AND PATIENTS: Prospective study of 76 patients with unresectable liver tumors who underwent RFA at a private tertiary referral hospital. INTERVENTIONS: Ninety-nine RFA operations were performed to ablate 328 tumors. MAIN OUTCOME MEASURES: Complications and local recurrence. RESULTS: There was 1 death (1%), major complications occurred in 7 operations (7%), and minor complications occurred in 10 operations (10%). Local recurrence was identified in 30 tumors (9%) at a mean follow-up of 15 months. Size (P<.001), vascular invasion (P<.001), and total volume ablated (P<.001) were associated with recurrence but the number of tumors was not (P =.39). CONCLUSION: Radiofrequency thermal ablation provides local control of advanced liver tumors with low recurrence and acceptable morbidity.  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