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   770881篇
  免费   55591篇
  国内免费   19116篇
耳鼻咽喉   9589篇
儿科学   19404篇
妇产科学   11830篇
基础医学   60883篇
口腔科学   18341篇
临床医学   89226篇
内科学   97596篇
皮肤病学   9755篇
神经病学   44256篇
特种医学   25425篇
外国民族医学   64篇
外科学   86397篇
综合类   108801篇
现状与发展   48篇
一般理论   55篇
预防医学   82113篇
眼科学   11181篇
药学   75995篇
  859篇
中国医学   60260篇
肿瘤学   33510篇
  2023年   11369篇
  2022年   20287篇
  2021年   34361篇
  2020年   28337篇
  2019年   32411篇
  2018年   28076篇
  2017年   25814篇
  2016年   25953篇
  2015年   27448篇
  2014年   52791篇
  2013年   52925篇
  2012年   50655篇
  2011年   49883篇
  2010年   42142篇
  2009年   38785篇
  2008年   36781篇
  2007年   37197篇
  2006年   32275篇
  2005年   25553篇
  2004年   18788篇
  2003年   16630篇
  2002年   13167篇
  2001年   11439篇
  2000年   9733篇
  1999年   7887篇
  1998年   7254篇
  1997年   6751篇
  1996年   5711篇
  1995年   5487篇
  1994年   5231篇
  1993年   4296篇
  1992年   4399篇
  1991年   3894篇
  1990年   3584篇
  1989年   3313篇
  1988年   3132篇
  1987年   2792篇
  1986年   2456篇
  1985年   6232篇
  1984年   7230篇
  1983年   5105篇
  1982年   5842篇
  1981年   5232篇
  1980年   4652篇
  1979年   4167篇
  1978年   3525篇
  1977年   2851篇
  1976年   2978篇
  1975年   2159篇
  1974年   1951篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
目的 通过分析特发性肺纤维化急性加重期(AE-IPF)患者证候与血清生物标志物的关系,为中医辨证治疗提供参考。方法 采用观察性研究设计,收集2019年3月至2019年11月三个中心的AE-IPF患者76例,其中痰热壅肺证26例、痰浊阻肺证50例,并纳入健康志愿者10例作为对照。采用ELISA测定患者血清CCL18、HMGB1、KL-6、MMP-7、SP-A和SP-D水平,分析与中医证候的相关性。结果 AE-IPF患者血清CCL18、HMGB1、KL-6、MMP-7、SP-A和SP-D水平均显著高于健康对照组。血清CCL18、HMGB1、KL-6、MMP-7和SP-D水平在痰热壅肺证和痰浊阻肺证患者间无显著性差异(P>0.05),而血清SP-A水平存在显著性差异(P<0.05)。结论 血清SP-A与AE-IPF证候存在一定的相关性,血清SP-A的浓度升高,与痰热壅肺证关系越密切,反之,血清SP-A浓度降低,则与痰浊阻肺证关系越密切。AE-IPF痰热壅肺证患者的预后可能较痰浊阻肺证患者更差。  相似文献   
83.
84.
85.
周敏  许震娟 《临床肺科杂志》2022,27(2):222-225,236
目的研究慢阻肺急性加重期患者延迟就医与家庭动力学的相关性,希望能够为慢阻肺急性加重期患者拟定护理措施提供科学依据。方法选取2017年1月-2019年12月我院240例诊断为慢阻肺急性加重期的患者为研究对象。根据患者入院就医的时间进行分组,时间≥24h的延迟就医的患者为观察组,时间<24h的及时就医患者为对照组。结果两组患者在文化水平、家庭年收入、在职状态、医疗保险和婚姻状况和APACHEⅡ评分比较(P<0.05)。观察组患者疾病观念、个性化、系统逻辑和家庭氛围得分比对照组高(P<0.05)。Pearman的相关性分析结果显示:慢阻肺急性加重期患者延迟就医时间与各个层面分数以及家庭动力总分呈现负相关性(P<0.05)。应变量为延迟就医为应变量,患者的一般资料为自变量,经Logistic回归分析结果表明:延迟就医的影响因素为文化水平、家庭动力评分、职业状态、家庭收入、婚姻状况和APACHEⅡ评分。结论慢阻肺急性加重期患者家庭动力总分与疾病观念、个性化、系统逻辑和家庭氛围得分与延迟就医时间呈现负相关性,患者延迟就医的影响因素是家庭动力学评分。  相似文献   
86.
87.
88.
《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   
89.
90.
BackgroundDental caries is the most common chronic childhood disease. Past studies revealed that grandparents provide their grandchildren with cariogenic foods and beverages (eg, those with free sugars and/or modified starches). Qualitative research can help identify what drives this phenomenon.ObjectiveOur aim was to examine mothers’ explanations for why grandparents in north central and central Appalachia give their grandchildren cariogenic foods and beverages.DesignA qualitative study on children’s oral health in Pennsylvania and West Virginia from 2018 through 2020 was performed. In-person, semi-structured interviews were conducted. Qualitative data from interviews were recorded, transcribed, and then coded using NVivo. Data analysis for this study was performed using thematic analysis with iterative theme development.Participants/settingThe participants were 126 mothers of children aged 3-5 years from West Virginia (n = 66) and Pittsburgh, PA (n = 60).Main outcome measuresMothers’ perspectives about why grandparents give their grandchildren cariogenic foods and beverages were analyzed.ResultsIn the study sample, 85% of mothers (n = 107/126) named at least 1 of their children’s grandparents as a member of their social network responsible for their children’s oral health. From these interviews, 85% of mothers (n = 91/107) discussed that grandparents gave their grandchildren cariogenic foods and beverages. The mothers described the following 4 themes to explain why grandparents gave their grandchildren cariogenic foods and beverages: privilege of the grandparent role; responsibilities of the grandparent role; symbol of care and affection; and limited consideration or understanding of the detrimental impact.ConclusionsGrandparents play a role in giving their grandchildren cariogenic foods and beverages, which could potentially contribute to childhood caries. Research is needed to develop effective social interventions to help some grandparents understand the implications of a cariogenic diet on their grandchildren’s oral health and/or decrease their provision of cariogenic foods and beverages.  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