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   217320篇
  免费   29581篇
  国内免费   6858篇
耳鼻咽喉   1719篇
儿科学   1919篇
妇产科学   5215篇
基础医学   16173篇
口腔科学   2172篇
临床医学   17879篇
内科学   21101篇
皮肤病学   1408篇
神经病学   762篇
特种医学   7474篇
外国民族医学   253篇
外科学   30294篇
综合类   28550篇
现状与发展   38篇
一般理论   3篇
预防医学   10373篇
眼科学   120篇
药学   15358篇
  133篇
中国医学   5320篇
肿瘤学   87495篇
  2024年   195篇
  2023年   4370篇
  2022年   6346篇
  2021年   10996篇
  2020年   10909篇
  2019年   9872篇
  2018年   9479篇
  2017年   10017篇
  2016年   10710篇
  2015年   12292篇
  2014年   18027篇
  2013年   17654篇
  2012年   14479篇
  2011年   14843篇
  2010年   10783篇
  2009年   11069篇
  2008年   11374篇
  2007年   10604篇
  2006年   9406篇
  2005年   7759篇
  2004年   6422篇
  2003年   5368篇
  2002年   4484篇
  2001年   4112篇
  2000年   3439篇
  1999年   2813篇
  1998年   2202篇
  1997年   1919篇
  1996年   1530篇
  1995年   1663篇
  1994年   1339篇
  1993年   1031篇
  1992年   905篇
  1991年   819篇
  1990年   619篇
  1989年   553篇
  1988年   477篇
  1987年   417篇
  1986年   313篇
  1985年   413篇
  1984年   350篇
  1983年   224篇
  1982年   236篇
  1981年   220篇
  1980年   202篇
  1979年   129篇
  1978年   104篇
  1977年   79篇
  1976年   65篇
  1975年   48篇
排序方式: 共有10000条查询结果,搜索用时 140 毫秒
91.
《Cancer cell》2022,40(6):674-693.e7
  1. Download : Download high-res image (235KB)
  2. Download : Download full-size image
  相似文献   
92.
IntroductionIn 2021, the U.S. Preventive Services Task Force (USPSTF) revised its lung cancer screening recommendations expanding its eligibility. As more smokers become eligible, cessation interventions at the point of screening could enhance the benefits. Here, we evaluate the effects of joint screening and cessation interventions under the new recommendations.MethodsA validated lung cancer natural history model was used to estimate lifetime number of low-dose computed tomography screens, percentage ever screened, lung cancer deaths, lung cancer deaths averted, and life-years gained for the 1960 U.S. birth cohort aged 45 to 90 years (4.5 million individuals). Screening occurred according to the USPSTF 2013 and 2021 recommendations with varying uptake (0%, 30%, 100%), with or without a cessation intervention at the point of screening with varying effectiveness (15%, 100%).ResultsScreening 30% of the eligible population according to the 2021 criteria with no cessation intervention (USPSTF 2021, 30% uptake, without cessation intervention) was estimated to result in 6845 lung cancer deaths averted and 103,725 life-years gained. These represent 28% and 34% increases, respectively, relative to screening according to the 2013 guidelines (USPSTF 2013, 30% uptake, without cessation intervention). Adding a cessation intervention at the time of the first screen with 15% effectiveness (USPSTF 2021, 30% uptake, with cessation intervention with 15% effectiveness) was estimated to result in 2422 additional lung cancer deaths averted (9267 total, ∼73% increase versus USPSTF 2013, 30% uptake, without cessation intervention) and 322,785 life-years gained (∼318% increase). Screening 100% of the eligible according to the 2021 guidelines with no cessation intervention (USPSTF 2021, 100% uptake, without cessation intervention) was estimated to result in 23,444 lung cancer deaths averted (∼337% increase versus USPSTF 2013, 30% uptake, without cessation intervention) and 354,330 life-years gained (∼359% increase). Adding a cessation intervention with 15% effectiveness (USPSTF 2021, 100% uptake, with cessation intervention with 15% effectiveness) would result in 31,998 lung cancer deaths averted (∼497% increase versus USPSTF 2013, 30% uptake, without cessation intervention) and 1,086,840 life-years gained (∼1309% increase).ConclusionsJoint screening and cessation interventions would result in considerable lung cancer deaths averted and life-years gained. Adding a one-time cessation intervention of modest effectiveness (15%) results in comparable life-years gained as increasing screening uptake from 30% to 100% because while cessation decreases mortality from many causes, screening only reduces lung cancer mortality. This simulation indicates that incorporating cessation programs into screening practice should be a priority as it can maximize overall benefits.  相似文献   
93.
Following adoption of moderately hypofractionated radiotherapy as a standard for localised prostate cancer, ultrahypofractioned radiotherapy delivered in five to seven fractions is rapidly being embraced by clinical practice and international guidelines. However, the question remains: how low can we go? Can radiotherapy for prostate cancer be delivered in fewer than five fractions? The current review summarises the evidence that radiotherapy for localised prostate cancer can be safely and effectively delivered in fewer than five fractions using high dose rate brachytherapy or stereotactic body radiotherapy. We also discuss important lessons learned from the single-fraction high dose rate brachytherapy experience.  相似文献   
94.
《Cancer cell》2022,40(8):835-849.e8
  1. Download : Download high-res image (220KB)
  2. Download : Download full-size image
  相似文献   
95.
We are reporting (a) updated incidence of cervical intraepithelial neoplasia (CIN) among women who did not have colposcopic or histopathological disease at baseline and (b) disease outcomes among women treated for CIN and their follow-up HPV status; in a cohort of women living with HIV (WHIV). The median overall follow-up was 3.5 years (IQR 2.8-4.3). The incidence of any CIN and that of CIN 2 or worse disease was 16.7 and 7.0 per 1000 person-years of observation (PYO), respectively. Compared with women who were HPV negative at baseline, women who cleared HPV infection had 23.95 times increased risk of incident CIN 2 or worse lesions (95% CI 2.40-661.07). Women with persistent HPV infection had 138.18 times increased risk of CIN 2 or worse lesions (95% CI 20.30-3300.22). Complete disease regression was observed in 65.6% of the HPV positive women with high-grade CIN and were treated with thermal ablation but HPV persistence was seen in 44.8% of those with high-grade disease. Among those who did not have any disease at baseline and were also HPV negative, about 87% (95% CI 83.79-89.48) women remained HPV negative during consecutive HPV test/s with the median interval of 3.5 years. Long-term surveillance of WHIV treated for any CIN is necessary for the prevention of cervical cancer among them. Our study provides an early indication that the currently recommended screening interval of 3 to 5 years among WHIV may be extended to at least 5 years among HPV negative women. Increasing the screening interval can be cost saving and improve scalability among WHIV to support WHO's cervical cancer elimination initiative.  相似文献   
96.
目的 基于网络药理学研究香菇多糖抑制三阴乳腺癌(TNBC)的作用机制并采用细胞和动物实验进行验证。方法 通过GeneCards数据库和DisGeNET数据库筛选与TNBC相关基因靶点,利用TCMID、PubChem、SwissTargetPrediction和GeneCards数据库查询香菇多糖相关基因靶点。使用Sangerbox软件进行基因本体论(GO)富集和京都基因与基因组百科全书(KEGG)通路富集分析。结合STRING数据库与Cytoscape 3.7.0软件将共同靶点进行可视化处理,筛选核心靶点,构建"化合物-靶点-通路"网络。利用Metascape软件进行转录因子及相关调控基因特异富集。体外培养小鼠TNBC细胞4T1和人TNBC细胞MDA-MB-231,磺酰罗丹明B染色法观察香菇多糖(31.25、62.5、125、250、500、1 000μg·mL-1)对细胞存活率的影响;健康雌性BABLC小鼠sc接种1×106个4T1-Luc细胞构建TNBC模型,通过小动物活体成像系统观察香菇多糖(100、200 mg·kg-1)对肿瘤生长的影响,实时荧光定量PCR (qRT-PCR)技术检测肿瘤组织信号转导和转录活化因子3(STAT3)和血管内皮生长因子A (VEGFA) mRNA表达。结果 数据库及软件分析得到香菇多糖治疗TNBC关键靶点52个,靶点主要涉及PI3K-Akt、AGE-RAGE、HIF-1、MAPK信号通路和肿瘤蛋白多糖相关通路,PPI分析得到VEGFA、STAT3、MAPK1、IL2、TNF、RELA、AKT1、MAPK3、BCL2L1HSP90AA1 10个hub基因。与对照组比较,香菇多糖对4T1和MDA-MB-231细胞存活率均有显著抑制作用(P<0.05、0.01),且作用呈浓度相关性;在给药14、21d后,与模型组比较,香菇多糖能够剂量相关性地抑制小鼠TNBC肿瘤的生长,高剂量组差异显著(P<0.05、0.01),21 d抑制率达到(91.9±4.7)%;与对照组比较,香菇多糖给药后能够剂量相关性抑制STAT3和VEGFA的mRNA表达,高剂量组差异显著(P<0.05、0.01)。结论 香菇多糖可通过多靶点、多途径协同作用抑制TNBC的生长。  相似文献   
97.
98.
99.
The coronavirus disease 2019 pandemic presented challenges for urology patients to receive care in the format of a traditional clinic visit. For renal cancer patients, active surveillance and postintervention surveillance are the standard components of management. Telehealth, which was defined as a televideo encounter via the BlueJeans (Verizon) platform (a telehealth platform), was used to ensure continuity of care. Telehealth using the televideo modality was shown to be an effective model of care delivery to provide an optimal patient experience with ease of use.  相似文献   
100.
PurposeA risk of percutaneous transthoracic needle biopsy (PTNB) is hemoptysis, which can range from mild to life-threatening. The reported occurrence of hemoptysis is 1.7% to 14.5%, and the demographic, patient, and procedure characteristics have not been extensively described. The purpose of this study was to assess the associations of demographic, patient, and procedure characteristics with the severity of hemoptysis.Materials and MethodsA single institution, single group, retrospective, electronic medical record (EMR) review was performed on all hemoptysis events occurring between 2008 and 2018. Demographic, clinical, and procedure variables were extracted from EMRs. Outcome of hemoptysis events was graded using Common Terminology Criteria for Adverse Events (CTCAE). Mild-moderate and severe hemoptysis were defined as CTCAE classifications of 1-2 and 3-5, respectively. Associations were generated using logistic regressions and Likelihood Ratio Chi-Square tests.ResultsIn 10 years, 14,665 PTNB resulted in 231 hemoptysis events occurring in 229 patients; 12.7% (n = 29) of those were severe. The strongest and statistically significant variables associated with an increased likelihood of a severe event, if an event occurred, were cigarette pack years (OR = 1.02, 95% C.I. = 1.01-1.04, p = .020); history of chronic obstructive pulmonary disease (COPD) (OR = 3.68, 95% C.I. = 1.53-8.82, p = .003); core biopsy technique (OR = 8.13, 95% CI = 1.07, 61.40, p = .042), and larger diameter needle (20 g vs. 18 g: OR = 2.60, 95% CI 1.09, 6.17, p = .031).ConclusionsPTNB-associated hemoptysis was an uncommon event that was rarely life-threatening. The extent of the patient’s smoking history, the diagnosis of COPD, and core biopsy technique were associated with an increased likelihood of severe hemoptysis.  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