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   12444篇
  免费   2807篇
  国内免费   132篇
耳鼻咽喉   415篇
儿科学   284篇
妇产科学   285篇
基础医学   546篇
口腔科学   300篇
临床医学   3310篇
内科学   2404篇
皮肤病学   427篇
神经病学   926篇
特种医学   434篇
外科学   1728篇
综合类   469篇
现状与发展   2篇
一般理论   6篇
预防医学   2065篇
眼科学   133篇
药学   458篇
  1篇
中国医学   111篇
肿瘤学   1079篇
  2024年   100篇
  2023年   469篇
  2022年   172篇
  2021年   336篇
  2020年   543篇
  2019年   251篇
  2018年   635篇
  2017年   674篇
  2016年   693篇
  2015年   776篇
  2014年   794篇
  2013年   1182篇
  2012年   577篇
  2011年   545篇
  2010年   634篇
  2009年   746篇
  2008年   467篇
  2007年   369篇
  2006年   409篇
  2005年   318篇
  2004年   298篇
  2003年   222篇
  2002年   203篇
  2001年   248篇
  2000年   172篇
  1999年   222篇
  1998年   309篇
  1997年   318篇
  1996年   344篇
  1995年   264篇
  1994年   190篇
  1993年   140篇
  1992年   163篇
  1991年   160篇
  1990年   141篇
  1989年   152篇
  1988年   119篇
  1987年   97篇
  1986年   93篇
  1985年   96篇
  1984年   85篇
  1983年   75篇
  1982年   63篇
  1981年   76篇
  1980年   35篇
  1979年   64篇
  1978年   35篇
  1977年   39篇
  1975年   34篇
  1970年   30篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Hepatitis B virus (HBV) reactivation is a remarkable risk during the chemotherapy for solid tumour patients. Nucleos(t)ide analogues (NAs) are recommended as prophylaxis for the reactivation of HBV infection in some cancer patients prior to systemic chemotherapy. Therefore, we performed a meta‐analysis aiming to determine the efficacy of prophylactic lamivudine on prevention of HBV reactivation and its related negative outcomes among solid tumour patients with chronic HBV infection receiving systemic chemotherapy. The primary outcome was HBV reactivation, and the secondary outcomes were HBV‐related hepatitis, chemotherapy disruption, mortality and tyrosine‐methio‐nine‐aspartate‐aspartate (YMDD) mutations. Twelve original researches involving 1,101 patients were analysed in this study. The relative risk of HBV reactivation in patients with lamivudine prophylaxis was significantly lower than that without prophylaxis (RR = 0.17, 95% CL: 0.10‐0.29, < .00001). Lamivudine prophylaxis reduced the relative risk of hepatitis (p < .00001), chemotherapy disruptions (p = .01) and mortality (p = .08) due to HBV reactivation. Lamivudine prophylaxis is effective in reducing HBV reactivation and its related negative outcomes, such as hepatitis and chemotherapy disruption and mortality among chemotherapeutic solid tumour patients with chronic HBV infection. Future studies should lay more emphasis on the early HBV screening, mode of treatment and duration of NAs prophylaxis among solid tumour patients receiving chemotherapy.  相似文献   
992.
Prolonged diagnostic intervals are associated with poorer outcomes, and the patient interval appears to be a substantial contributor to the overall length of the diagnostic interval. This study sought to understand how the broader context of people's lives influenced symptom appraisal and help‐seeking, comparing experiences by length of the patient interval. Patients referred with a suspicion of lung or colorectal cancer were invited to complete a questionnaire about their symptoms, with 26 respondents purposively sampled to take part in a semi‐structured interview about their patient intervals. Embodied experience, appraisal, help‐seeking decision‐making and consultation were identified as component stages of the patient interval, with the factors affecting movement between these stages located in one of four contextual domains: individual experience, interpersonal relationships, healthcare system interactions and social and temporal context. The length of the patient interval was related to the type of symptom(s) experienced, discussion of symptoms with others and the social responsibilities people held during symptomatic periods. A contextual model of the patient interval illustrates the stages and domains of this interval, as grounded in the data from this study. The model has potential application to future studies examining the patient interval for a range of symptoms.  相似文献   
993.
Although many of the 16,000 children in the United States diagnosed who are with cancer each year could benefit from pediatric palliative care, these services remain underused. Evidence regarding the barriers impeding access to comprehensive palliative care is dispersed in the literature, and evidence specific to pediatric oncology remains particularly sparse. The purpose of the current review was to synthesize the existing literature regarding these barriers and the strategies offered to address them. The authors completed a literature search using the PubMed, Cumulative Index to Nursing and Allied Health Literature (CINAHL), and Web of Science databases. In total, 71 articles were reviewed. Barriers to accessing pediatric palliative care were categorized according to the 4 levels of a modified socioecological model (ie, barriers related to policy/payment, health systems, organizations, and individuals). Major themes identified at each level included: 1) the lack of consistent and adequate funding mechanisms at the policy/payment level, 2) the lack of pediatric palliative care programs and workforce at the health systems level, 3) difficulties integrating palliative care into existing pediatric oncology care models at the organizational level, and 4) the lack of knowledge about pediatric palliative care, discomfort with talking about death, and cultural differences between providers and patients and their families at the individual level. Recommendations to address each of the barriers identified in the literature are included. Cancer 2018;124:2278‐88 . © 2018 American Cancer Society.  相似文献   
994.
995.
996.
997.
Background: Manipulation and suspension of the superficial musculoaponeurotic system (SMAS) is performed by 74% of rhytidectomy surgeons. Multiple variations in suture techniques are employed in this task, but they have never been evaluated for differences in their ability to withstand stress. Objective: To compare the biomechanical properties of two different suture techniques that are used in SMAS plications during rhytidectomy: a double‐layered running locking (DRL) stitch and multiple horizontal mattress stitches. Methods: Fourteen horizontal mattress plications, in rows of six sutures, and comparable lengths of 16 DRL stitch plications of pig skin samples, were stressed using a tensometer with grip displacement increasing at a constant rate of 0.5 cm/Min. The required force to cause plication failure was recorded for each sample at three suture break points. Results: There was no significant difference between the two groups in the force required to cause the initial suture failure. Unlike the horizontal mattress plication, an initial break seemed to cause minimal to no distortion of the DRL tissue plication. When results were normalized by the initial break forces to account for small variations in tissue properties, the force ratio required to cause a second suture break was significantly larger in the DRL group than in the horizontal mattress technique. This is evidenced by the average second to first break force ratios of 1.62 vs. 1.13 for the DRL and horizontal mattress stitches, respectively, with a P‐value of .60. The mean ratios of third to first break forces for the DRL and horizontal mattress groups were 2.08 and 0.91, respectively, with a P‐value of .08. Conclusion: The DRL stitch requires more force than the horizontal mattress stitch to cause significant failure of tissue plication. This technique may enable plastic surgeons to avoid early revision rhytidectomy due to suture failure, and to create a long‐lasting, youthful cosmetic result.  相似文献   
998.
Newbrough's Third Position is discussed in terms of its utility as a framework within which to understand and resolve interpersonal differences, seemingly irresolvable diametric differences, and conflictual situations. The framework's essential elements and its application is illustrated through the presentation of a series of fictitious scenarios that open with conflict and close with a resolution in which the interested parties feel heard and satisfied. The intent of the commentary is to re‐introduce community psychologists to this framework and encourage its consideration, application, and investigation in responding to community‐based conflicts and the resolution of seeming impasses. The Third Position is presented as a valuable tool for the community psychologist involved with conflict resolution, community consultation, and community development. © 2008 Wiley Periodicals, Inc.  相似文献   
999.
1000.
The caries‐protective effect of milk arid fluoridated milk on enamel has been reported; however, few data are available concerning the role of milk and/or fluoridated milk on root surfaces. The aim of this study was to compare the affect of plain and fluoridated milk on root surface caries. Artificial root surface lesions were created, sectioned and analyzed using polarized light microscopy (PLM) and microradiography (MRG). The sections were covered except for the original surface and assigned to a treatment group. The samples were immersed in 2% plain milk or fluoridated milk for 40 hours and re‐evaluated, Changes were measured and mean differences were compared with an unpaired t‐test. Both techniques revealed a reduction in lesion depth for each milk group; however, a significantly greater reduction (p<0.05) was observed with the fluoridated milk. These results suggest that fluoridated milk may have a beneficial effect on the remineralization of root surface caries.  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