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   355233篇
  免费   24885篇
  国内免费   7621篇
耳鼻咽喉   5876篇
儿科学   9727篇
妇产科学   6568篇
基础医学   28124篇
口腔科学   8997篇
临床医学   38603篇
内科学   43055篇
皮肤病学   4635篇
神经病学   20887篇
特种医学   9432篇
外国民族医学   32篇
外科学   42659篇
综合类   52504篇
现状与发展   12篇
一般理论   29篇
预防医学   34131篇
眼科学   5261篇
药学   30414篇
  381篇
中国医学   30483篇
肿瘤学   15929篇
  2023年   5581篇
  2022年   8219篇
  2021年   13263篇
  2020年   13208篇
  2019年   18937篇
  2018年   16520篇
  2017年   13439篇
  2016年   11015篇
  2015年   10392篇
  2014年   21107篇
  2013年   22672篇
  2012年   19179篇
  2011年   20836篇
  2010年   16720篇
  2009年   15531篇
  2008年   15127篇
  2007年   15551篇
  2006年   13622篇
  2005年   11849篇
  2004年   9701篇
  2003年   8484篇
  2002年   6683篇
  2001年   6007篇
  2000年   4923篇
  1999年   4220篇
  1998年   3267篇
  1997年   3090篇
  1996年   2658篇
  1995年   2721篇
  1994年   2624篇
  1993年   2104篇
  1992年   2142篇
  1991年   1842篇
  1990年   1619篇
  1989年   1440篇
  1988年   1364篇
  1987年   1185篇
  1985年   3849篇
  1984年   4873篇
  1983年   3398篇
  1982年   3865篇
  1981年   3602篇
  1980年   3195篇
  1979年   2940篇
  1978年   2559篇
  1977年   1918篇
  1976年   2159篇
  1975年   1638篇
  1974年   1432篇
  1973年   1279篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
41.
42.
《Vaccine》2022,40(7):1001-1009
Vaccination guidelines for dogs and cats indicate that core vaccines (for dogs, rabies, distemper, adenovirus, parvovirus; for cats, feline parvovirus, herpes virus-1, calicivirus) are essential to maintain health, and that non-core vaccines be administered according to a clinician’s assessment of a pet’s risk of exposure and susceptibility to infection. A reliance on individual risk assessment introduces the potential for between-practice inconsistencies in non-core vaccine recommendations. A study was initiated to determine non-core vaccination rates of dogs (Leptospira, Borrelia burgdorferi, Bordetella bronchiseptica, canine influenza virus) and cats (feline leukemia virus) in patients current for core vaccines in veterinary practices across the United States. Transactional data for 5,531,866 dogs (1,670 practices) and 1,914,373 cats (1,661 practices) were retrieved from practice management systems for the period November 1, 2016 through January 1, 2020, deidentified and normalized. Non-core vaccination status was evaluated in 2,798,875 dogs and 788,772 cats that were core-vaccine current. Nationally, median clinic vaccination rates for dogs were highest for leptospirosis (70.5%) and B. bronchiseptica (68.7%), and much lower for canine influenza (4.8%). In Lyme-endemic states, the median clinic borreliosis vaccination rate was 51.8%. Feline leukemia median clinic vaccination rates were low for adult cats (34.6%) and for kittens and 1-year old cats (36.8%). Individual clinic vaccination rates ranged from 0 to 100% for leptospirosis, B. bronchiseptica and feline leukemia, 0–96% for canine influenza, and 0–94% for borreliosis. Wide variation in non-core vaccination rates between clinics in similar geographies indicates that factors other than disease risk are driving the use of non-core vaccines in pet dogs and cats, highlighting a need for veterinary practices to address gaps in patient protection. Failure to implement effective non-core vaccination strategies leaves susceptible dogs and cats unprotected against vaccine-preventable diseases.  相似文献   
43.
PurposeTo review and to compare indirectly the outcomes of minimally invasive therapies for the treatment of lower urinary tract symptoms secondary to benign prostatic hyperplasia.Materials and MethodsA literature search via Medline and Cochrane Central databases was completed for randomized control studies published between January 2000 to April 2020 for the following therapies: Rezum, Urolift, Aquablation, and prostatic artery embolization (PAE). Data on the following variables were included: International prostate symptom score (IPSS), maximum urinary flow rate, quality of life, and postvoid residual (PVR). Standard mean differences between treatments were compared through a meta-analysis using transurethral resection of the prostate (TURP) to assess differences in treatment effect.ResultsThere was no significant difference in outcomes between therapies for IPSS at the 3, 6, and 12-month follow ups. Although outcomes for Rezum were only available out to 3 months, there were no consistently significant differences in outcomes when comparing Aquablation versus PAE versus Rezum. TURP PVR was significantly better than Urolift at 3, 6, and 12 months. No significant differences in minor or major adverse events were noted.ConclusionAlthough significant differences in outcomes were limited, Aquablation and PAE were the most durable at 12 months. PAE has been well studied on multiple randomized control trials with minimal adverse events while Aquablation has limited high quality data and has been associated with bleeding-related complications.  相似文献   
44.
《Cancer radiothérapie》2022,26(3):502-516
The aim of the review was to present the current literature status about replanning regarding anatomical and dosimetric changes in the target and OARs in the head and neck region during radiotherapy, to discuss and to analyze factors influencing the decision for adaptive radiotherapy of head and neck cancer patients. Significant progress has been made in head and neck patients’ evaluation and qualification for adapted radiotherapy over the past ten years. Many factors leading to anatomical and dosimetric changes during treatment have been identified. Based on the literature, the most common factors triggering re-plan are weight loss, tumor and nodal changes, and parotid glands shrinkage. The fluctuations in dose distribution in the clinical area are significant predictive factors for patients’ quality of life and the possibility of recovery. It has been shown that re-planning influence clinical outcomes: local control, disease free survival and overall survival. Regarding literature studies, it seems that adaptive radiotherapy would be the most beneficial for tumors of immense volume or those in the nearest proximity of the OARs. All researchers agree that the timing of re-planning is a crucial challenge, and there are still no clear consensus guidelines for time or criteria of re-planning. Nowadays, thanks to significant technological progress, the decision is mostly made based on observation and supported with IGRT verification. Although further research is still needed, adaptive strategies are evolving and now became the state of the art of modern radiotherapy.  相似文献   
45.
46.
47.
48.
In the present study, we aimed to observe the effects of ethanol extract of Oxalis corniculata L. on bleeding time (BT) and coagulation time (CT) and determine its acute toxicity in mice. Firstly, the ethanol extract of O. corniculata was administered to 40 mice, which were randomly divided into the normal control group, Yunnan Baiyao control group, low-dose group, and high-dose group. The low-dose (0.6 g/kg) and high-dose (1.2 g/kg) groups received ethanol extract of O. corniculata by gavage, and the BT and CT of the mice were measured by the slide method and tail clipping method, respectively. Secondly, the median lethal dose method was used with 50 mice to observe the physiological state, poisoning reaction, and death of the mice after intragastric administration. Finally, on the 14th day of the experiment, a necropsy was performed to observe any abnormality of the organs. In conclusion, in the coagulation and hemostasis tests, there were no statistical differences between the groups (P > 0.05), while there was a significant dose-response relationship, and the BT and CT were significantly shorter than those of the negative control group, which were comparable to the Yunnan Baiyao control group. Moreover, in the acute toxicity test, the median lethal dose of ethanol extract of O. corniculata was 6.0291 g/kg, with a 95% confidence interval of 5.3065–6.7829 mg/kg.  相似文献   
49.
The representation of nursing faculty of color is disproportionate to that in the general population, despite recruitment and retention strategies. Boosting the presence of nursing faculty of color requires an understanding of factors that undermine diversity initiatives and calls for the adoption of innovative practices. This article addresses the importance of racial and ethnic diversity within nursing education. Furthermore, it examines the factors that prevent the recruitment and retention of a racially and ethnically diverse nursing faculty workforce and provides evidence-based recommendations for increasing diversity among nursing faculty and nursing organizations.  相似文献   
50.
《Australian critical care》2022,35(5):491-498
BackgroundAn activity to provide a tangible keepsake following the death of a loved one is termed ‘memory making’. However, limited evidence is available related to professionals' education and support to provide memory making opportunities in the adult intensive care unit (ICU). Having a greater understanding of healthcare professionals’ experiences can inform future patient/family care and support for professionals in end-of-life care.ObjectiveThe objective of this study was to describe what participants perceive memory making to be, if they have facilitated memory making activities as part of their practice, if they perceive it as part of their role, and if they have the necessary skills to do so.MethodsSeventy-five registered nurses (75% response rate), 19 medical doctors (76% response rate), and two social workers (66.7% response rate) completed a survey at a single tertiary referral centre in an adult ICU.ResultsParticipants reported memory making to include the creation of tangible keepsakes as well as nontangible activities. Overall, participants reported high agreement scores that the responsibility for initiating memory making predominately belonged to the nurse. Participants reported skills most needed involved the ability to interact with the family, being open to the concept, and integrating memory making into their standard of care. Having developed a rapport with families was considered an enabler, whereas lack of knowledge and clinical workload were reported as inhibitors to offering memory making.ConclusionsOverall, participants in this study reported positive experiences with offering memory making to families during end-of-life care in the adult ICU. Nurses are more likely to perceive professional responsibility for offering memory making, likely due to their increased time at the bedside and higher prominence and leadership in other end-of-life practices. To support professionals, education should include conceptual knowledge, procedural knowledge of keepsake creations, communication techniques using reflective practices, and organisational support to facilitate time requirements.  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