全文获取类型
收费全文 | 13829篇 |
免费 | 1465篇 |
国内免费 | 36篇 |
专业分类
耳鼻咽喉 | 165篇 |
儿科学 | 330篇 |
妇产科学 | 369篇 |
基础医学 | 1889篇 |
口腔科学 | 411篇 |
临床医学 | 2044篇 |
内科学 | 2249篇 |
皮肤病学 | 224篇 |
神经病学 | 1244篇 |
特种医学 | 423篇 |
外国民族医学 | 3篇 |
外科学 | 1975篇 |
综合类 | 324篇 |
一般理论 | 11篇 |
预防医学 | 1407篇 |
眼科学 | 216篇 |
药学 | 1118篇 |
中国医学 | 11篇 |
肿瘤学 | 917篇 |
出版年
2021年 | 195篇 |
2020年 | 117篇 |
2019年 | 191篇 |
2018年 | 235篇 |
2017年 | 194篇 |
2016年 | 200篇 |
2015年 | 219篇 |
2014年 | 306篇 |
2013年 | 454篇 |
2012年 | 641篇 |
2011年 | 656篇 |
2010年 | 375篇 |
2009年 | 363篇 |
2008年 | 571篇 |
2007年 | 671篇 |
2006年 | 625篇 |
2005年 | 604篇 |
2004年 | 572篇 |
2003年 | 542篇 |
2002年 | 573篇 |
2001年 | 489篇 |
2000年 | 499篇 |
1999年 | 434篇 |
1998年 | 165篇 |
1997年 | 134篇 |
1996年 | 153篇 |
1995年 | 159篇 |
1994年 | 151篇 |
1993年 | 128篇 |
1992年 | 297篇 |
1991年 | 296篇 |
1990年 | 288篇 |
1989年 | 253篇 |
1988年 | 264篇 |
1987年 | 245篇 |
1986年 | 254篇 |
1985年 | 253篇 |
1984年 | 189篇 |
1983年 | 159篇 |
1981年 | 117篇 |
1980年 | 96篇 |
1979年 | 177篇 |
1978年 | 113篇 |
1977年 | 112篇 |
1976年 | 106篇 |
1974年 | 109篇 |
1973年 | 108篇 |
1972年 | 111篇 |
1971年 | 98篇 |
1968年 | 113篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
Weiyu Ye Anna Olsson-Brown Robert A. Watson Vincent T. F. Cheung Robert D. Morgan Isar Nassiri Rosalin Cooper Chelsea A. Taylor Umair Akbani Oliver Brain Rubeta N. Matin Nicholas Coupe Mark R. Middleton Mark Coles Joseph J. Sacco Miranda J. Payne Benjamin P. Fairfax 《British journal of cancer》2021,124(10):1661
Background Immune checkpoint blockers (ICBs) activate CD8+ T cells, eliciting both anti-cancer activity and immune-related adverse events (irAEs). The relationship of irAEs with baseline parameters and clinical outcome is unclear.Methods Retrospective evaluation of irAEs on survival was performed across primary (N = 144) and secondary (N = 211) independent cohorts of patients with metastatic melanoma receiving single agent (pembrolizumab/nivolumab—sICB) or combination (nivolumab and ipilimumab—cICB) checkpoint blockade. RNA from pre-treatment and post-treatment CD8+ T cells was sequenced and differential gene expression according to irAE development assessed.Results 58.3% of patients developed early irAEs and this was associated with longer progression-free (PFS) and overall survival (OS) across both cohorts (log-rank test, OS: P < 0.0001). Median survival for patients without irAEs was 16.6 months (95% CI: 10.9–33.4) versus not-reached (P = 2.8 × 10−6). Pre-treatment monocyte and neutrophil counts, but not BMI, were additional predictors of clinical outcome. Differential expression of numerous gene pathway members was observed in CD8+ T cells according to irAE development, and patients not developing irAEs demonstrating upregulated CXCR1 pre- and post-treatment.Conclusions Early irAE development post-ICB is associated with favourable survival in MM. Development of irAEs is coupled to expression of numerous gene pathways, suggesting irAE development in-part reflects baseline immune activation.Subject terms: Immunotherapy, Melanoma 相似文献
3.
ABSTRACTCommunication between health professionals and patients is an intergroup phenomenon where the health professional has the most power and status. Over the past few decades, there has been a steady increase in the availability to patients of information about healthcare and specific diseases on the Internet. In this paper, we ask whether the use of Internet health information assists patients to manage their consultations with health professionals better and whether it alters the intergroup dynamic by providing a more equal status for patients. In this study 370 participants from Australia and Canada completed a survey that included a ‘willingness to communicate with health professionals’ scale. They also commented on their use and trust of Internet health information. Thematic analysis suggests that patients’ use of Internet health information serves as a broker between patients and their health provider in health consultations. We discuss the implications of these findings for health practitioners as they address how easier Internet access influences patient interactions with health professionals. We consider future research directions these finding provide in explaining communication behaviour in this context. 相似文献
4.
Henry Havel Gregory Finch Pamela Strode Marc Wolfgang Stephen Zale Iulian Bobe Hagop Youssoufian Matthew Peterson Maggie Liu 《The AAPS journal》2016,18(6):1373-1378
Advancing nanomedicines from concept to clinic requires integration of new science with traditional pharmaceutical development. The medical and commercial success of nanomedicines is greatly facilitated when those charged with developing nanomedicines are cognizant of the unique opportunities and technical challenges that these products present. These individuals must also be knowledgeable about the processes of clinical and product development, including regulatory considerations, to maximize the odds for successful product registration. This article outlines these topics with a goal to accelerate the combination of academic innovation with collaborative industrial scientists who understand pharmaceutical development and regulatory approval requirements—only together can they realize the full potential of nanomedicines for patients. 相似文献
5.
6.
7.
Maggie L. Westfal David C. Chang Cassandra M. Kelleher 《Journal of pediatric surgery》2019,54(1):140-144
Purpose
The purpose of this study was to evaluate trends in demographics and outcomes of pediatric breast cancer in a United States population-based cohort.Methods
The Surveillance, Epidemiology, and End Results (SEER) database was utilized to identify all pediatric patients with malignant breast tumors between 1973 and 2014. Analysis was performed using Stata Statistical Software version 13.1. Associations between categorical variables were made using X2 test. Log-rank test was used for univariate survival analysis. Kaplan–Meier analysis investigated five-year survival rates across several variables. Adjusted analysis was performed using a Cox Proportional-Hazards regression.Results
134 patients with breast malignancies were identified. Carcinoma was the most prevalent histology (48.5%), followed by fibroepithelial tumors (FETs) (35.1%), and sarcoma (14.2%). FETs were twice as common in black compared to nonblack patients (56.3% vs. 29.0%, p?<?0.01). Analyzing histology by stage revealed that 100% of FETs were early stage disease (p?<?0.0001). 46.7% of the tumors tested were ER/PR negative, more than twice as many compared to the published adult estimate of 20.0%. Unadjusted survival analysis revealed worse survival for patients with adenocarcinoma/sarcomas, advanced stage, and high grade disease, without a survival difference between races.Conclusion
Breast cancer remains a rare malignancy among pediatric patients. Although black patients were found to have more noncarcinomatous tumors with less advanced disease, this did not confer a survival advantage.Type of study
Retrospective cohort study.Level of evidence
Level III. 相似文献8.
Thomas S. Klitzner Maggie Lee Sandra Rodriguez Ruey‐Kang R. Chang 《Congenital heart disease》2006,1(3):77-88
Background. It has been reported that gender differences in cardiovascular outcomes found in adults also are present in children who undergo surgical repair for congenital heart disease. Methods. California statewide hospital discharge data 1989–99 were used to study outcomes in children <18 years undergoing cardiac surgery. Hospital discharge data were linked to death registry data to study postdischarge death within 30 days of discharge. We used logistic regression to evaluate the effect of gender on mortality controlling for age, race and ethnicity, type of insurance, household income, date and month of surgery, type of admission, hospital case volume, and various types of procedures. Results. There were 25 402 cardiac surgery cases with 1505 in‐hospital deaths (mortality rate of 5.92%). An additional 37 deaths occurred within 30 days after hospital discharge. Crude mortality rates for males (5.99%) and females (5.84%) were not significantly different. However, fewer neonates were female and females underwent a higher proportion of low‐risk procedures than males. Logistic regression revealed that females, compared with males, had a significantly higher odds ratio (OR) for in‐hospital mortality (OR = 1.18, P < .01) and overall (up to 30 days post discharge) mortality (OR = 1.18, P < .01). The risk‐adjusted length of hospital stay was similar between females and males while charges per hospital day were slightly higher in females than males. The prevalence of Down syndrome, pulmonary hypertension, and failure to thrive were higher in females. Conclusions. Female gender is associated with an 18% higher in‐hospital and 30‐day postdischarge mortality as compared with male gender. There was no difference in length of hospital stay between males and females. The mechanism by which female gender acts as a risk factor requires further investigation. 相似文献
9.
R. Watson T. Kozlowski V. Nickeleit J. T. Woosley J. L. Schmitz S. L. Zacks J. H. Fair D. A. Gerber K. A. Andreoni 《American journal of transplantation》2006,6(12):3022-3029
Antibody-mediated rejection (AMR) after liver transplantation is recognized in ABO incompatible and xeno-transplantation, but its role after ABO compatible liver transplantation is controversial. We report a case of ABO compatible liver transplantation that demonstrated clinical, serological and histological signs of AMR without evidence of concurrent acute cellular rejection. AMR with persistently high titers of circulating donor specific antibodies resulted in graft injury with initial centrilobular hepatocyte necrosis, fibroedematous portal expansion mimicking biliary tract outflow obstruction, ultimately resulting in extensive bridging fibrosis. Immunofluorescence microscopy demonstrated persistent, diffuse linear C4d deposits along sinusoids and central veins. Despite intense therapeutic intervention including plasmapheresis, IVIG and rituximab, AMR led to graft failure. We present evidence that an antibody-mediated alloresponse to an ABO compatible liver graft can cause significant graft injury independent of acute cellular rejection. AMR shows distinct histologic changes including a characteristic staining profile for C4d. 相似文献
10.