全文获取类型
收费全文 | 217287篇 |
免费 | 21606篇 |
国内免费 | 14014篇 |
专业分类
耳鼻咽喉 | 1736篇 |
儿科学 | 2671篇 |
妇产科学 | 2524篇 |
基础医学 | 29554篇 |
口腔科学 | 3930篇 |
临床医学 | 26146篇 |
内科学 | 29389篇 |
皮肤病学 | 2194篇 |
神经病学 | 11466篇 |
特种医学 | 7876篇 |
外国民族医学 | 115篇 |
外科学 | 20894篇 |
综合类 | 37563篇 |
一般理论 | 24篇 |
预防医学 | 14766篇 |
眼科学 | 6126篇 |
药学 | 24787篇 |
197篇 | |
中国医学 | 13406篇 |
肿瘤学 | 17543篇 |
出版年
2024年 | 178篇 |
2023年 | 3160篇 |
2022年 | 5511篇 |
2021年 | 9489篇 |
2020年 | 8995篇 |
2019年 | 10096篇 |
2018年 | 6468篇 |
2017年 | 6946篇 |
2016年 | 5929篇 |
2015年 | 9505篇 |
2014年 | 12292篇 |
2013年 | 11323篇 |
2012年 | 16183篇 |
2011年 | 17801篇 |
2010年 | 12060篇 |
2009年 | 9688篇 |
2008年 | 11928篇 |
2007年 | 11836篇 |
2006年 | 11347篇 |
2005年 | 10703篇 |
2004年 | 7545篇 |
2003年 | 7341篇 |
2002年 | 6204篇 |
2001年 | 5250篇 |
2000年 | 4901篇 |
1999年 | 4632篇 |
1998年 | 2972篇 |
1997年 | 2989篇 |
1996年 | 2245篇 |
1995年 | 2162篇 |
1994年 | 1881篇 |
1993年 | 1277篇 |
1992年 | 1539篇 |
1991年 | 1375篇 |
1990年 | 1232篇 |
1989年 | 1125篇 |
1988年 | 974篇 |
1987年 | 817篇 |
1986年 | 737篇 |
1985年 | 585篇 |
1984年 | 441篇 |
1983年 | 346篇 |
1982年 | 298篇 |
1981年 | 253篇 |
1980年 | 217篇 |
1979年 | 219篇 |
1978年 | 191篇 |
1977年 | 209篇 |
1976年 | 191篇 |
1974年 | 154篇 |
排序方式: 共有10000条查询结果,搜索用时 93 毫秒
1.
Yan Gao MD Yizhen Liu MD PhD Yafei Wang MD Qingyuan Zhang MD Depei Wu MD Xu Ye MD Jianqiu Wu MD Wei Xu MD Jianfeng Zhou MD Yu Yang MD Hong Cen MD Feng Zhang MD Ying Xiang MD Xiaoqiong Tang MD Kaiyang Ding MD JinYing Lin MD Lei Ma MD Shunqing Wang MD Hao Yu MD Yang Zhao MD Bin Song MD Fangfang Lv MD Huiqiang Huang MD 《Cancer》2023,129(4):551-559
2.
3.
Biaoming Xu Yu Chen Mingjing Peng Jin Hai Zheng Chaohui Zuo 《International journal of cancer. Journal international du cancer》2023,152(2):110-122
Pancreatic cancer (PC) is a cancer of the digestive system, and pancreatic ductal adenocarcinoma (PDAC) accounts for approximately 90% of all PC cases. Exosomes derived from PDAC (PDAC-exosomes) promote PDAC development and metastasis. Exosomes are nanoscale vesicles secreted by most cells, which can carry biologically active molecules and mediate communication and cargo transportation among cells. Recent studies have focused on transforming exosomes into good drug delivery systems (DDSs) to improve the clinical treatment of PDAC. This review considers PDAC as the main research object to introduce the role of PDAC-exosomes in PDAC development and metastasis. This review focuses on the following two themes: (a) the great potential of PDAC-exosomes as new diagnostic markers for PDAC, and (b) the transformation of exosomes into potential DDSs. 相似文献
4.
Xiaoke Zhu Yu Heng Jian Zhou Hanqing Lin Liang Zhou Ming Zhang Pengyu Cao Lei Tao 《International journal of cancer. Journal international du cancer》2023,153(1):94-102
A high risk of developing second primary malignancy (SPM) has been reported among head and neck cancer patients. Here, we aimed to statistically quantify the impact of SPM development on the survival of head and neck cancer patients. Our study was conducted using the Surveillance, Epidemiology and End Results database to collect the data of 48 316 patients who received curative surgical resection for initial primary head and neck squamous cell carcinoma (IP-HNSCC) in 1975 to 2019. SPM diagnosis was treated as a time-varying covariate and multivariable Cox regression analysis was conducted to estimate the association between SPM development and survival, overall or by the subsite of IP-HNSCC. Of the included patients, 11 238 patients (23.3%) developed SPM during the follow-up period. A significant reduction in survival was observed among patients with SPM (hazard ratio [HR] for overall survival, 3.30; 95% confidence interval [CI]: 3.20-3.41). The impact of SPM development on reduced survival was more significant in patients with localized IP-HNSCC vs regional IP-HNSCC (HROS, 3.41; 95% CI: 3.24-3.6 vs HROS, 3.18; 95% CI: 3.05-3.31; P for interaction <.001). The survival impact of SPM development was more evident in younger patients than in older patients. SPM in lung and bronchus was associated with the most pronounced reduction in survival, overall and across all subsites of HNSCC. Our results indicated that SPM development led to a significant reduction in survival. A greater survival benefit may be achieved through intensive surveillance for SPM in lung and bronchus targeting younger patients and those with localized HNSCC. 相似文献
5.
Shuang Lu Hong Sun Kim Yubo Cao Karan Bedi Lili Zhao Ishwarya Venkata Narayanan Brian Magnuson Yumei Gu Jing Yang Zhujun Yi Sepideh Babaniamansour Sargis Shameon Chang Xu Michelle T. Paulsen Ping Qiu Sivakumar Jeyarajan Mats Ljungman Dafydd Thomas Yali Dou Howard Crawford Marina Pasca di Magliano Kai Ge Bo Yang Jiaqi Shi 《International journal of cancer. Journal international du cancer》2023,153(3):552-570
6.
Qiangsheng He Chongfei Huang Xiwen Qin Yuanyuan Yu Di Tang Junjie Huang Zi Chong Kuo Yuyao Ling Deli Mao Bin Xia Wenjing Li Kuiqing Lu Man Yang Yulong He Wenbo Meng Jinqiu Yuan Yihang Pan 《International journal of cancer. Journal international du cancer》2023,153(5):942-949
Recent epidemiological studies suggested that proton pump inhibitor (PPI) use was associated with an increased risk of biliary tract cancer (BTC), however, confounders were not adequately controlled. Our study aimed to evaluate PPI use and subsequent risk of BTC and its subtypes in three well-established cohorts. We conducted a pooled analysis of the subjects free of cancers in UK Biobank (n = 463 643), Nurses' Health Study (NHS, n = 80 235) and NHS II (n = 95 869). Propensity score weighted Cox models were used to estimate marginal HRs of PPIs use on BTC risk, accounting for potential confounders. We documented 284 BTC cases in UK Biobank (median follow-up: 7.6 years), and 91 cases in NHS and NHS II cohorts (median follow-up: 15.8 years). In UK biobank, PPI users had a 96% higher risk of BTC compared to nonusers in crude model (HR 1.96, 95% CI 1.44-2.66), but the effect was attenuated to null after adjusting for potential confounders (HR 0.95, 95% CI 0.60-1.49). PPI use was not associated with risk of BTC in the pooled analysis of three cohorts (HR 0.93, 95% CI 0.60-1.43). We also observed no associations between PPI use with risk of intrahepatic (HR 1.00, 95% CI 0.49-2.04), extrahepatic bile duct (HR 1.09, 95% CI 0.52-2.27) and gallbladder cancers (HR 0.66, 95% CI 0.26-1.66) in UK Biobank. In summary, regular use of PPIs was not associated with the risk of BTC and its subtypes. 相似文献
7.
Elvin S. Cheng Louiza S. Velentzis Marianne Weber Julia Steinberg Karen Canfell Xue Qin Yu 《International journal of cancer. Journal international du cancer》2023,152(12):2528-2540
There is growing, but inconsistent evidence suggesting oestrogen may play a key role in lung cancer development, especially among never-smoking women for whom lung cancer risk factors remain largely elusive. Using the China Kadoorie Biobank, a large-scale prospective cohort with 302 510 women aged 30 to 79 years recruited from 10 regions in China during 2004 to 2008, we assessed the risk of lung cancer death among self-reported never-smoking women who were cancer-free at baseline, in relation to age at menarche, age at menopause, time since menopause, prior use of oral contraceptives (OCP), number of livebirths, breastfeeding and age at first livebirth. Women were followed up to December 31, 2016 with linkage to mortality data. Hazard ratios (HR) and 95% confidence intervals (CI) were estimated using Cox regression, adjusting for key confounders including several socio-demographic, environmental and lifestyle factors. Among 287 408 never-smoking women, 814 died from lung cancer with a median follow-up of 10.3 years. Women who had used OCP within 15 years prior to baseline had a significantly higher hazard of lung cancer death compared with never-users: HR = 1.85 (95% CI: 1.14-3.00) and risk increased by 6% with each additional year of use: HR = 1.06 (1.01-1.10). Among parous women, the hazard of lung cancer death increased by 13% with each single livebirth: HR = 1.13 (1.05-1.23); and among post-menopausal women, the risk increased by 2% with each year since menopause: HR = 1.02 (1.01-1.04). These results suggest that reproductive factors which were proxies for lower endogenous oestrogen level, for example, longer duration of OCP use, could play a role in lung cancer development. 相似文献
8.
9.
Post-induction hypotension is common and associated with postoperative complications. We hypothesised that pneumatic leg compression reduces post-induction hypotension in elderly patients undergoing robot-assisted laparoscopic prostatectomy. In this double-blind randomised study, patients were allocated randomly to the pneumatic leg compression group (n = 50) or control (n = 50). In the intervention group, pneumatic leg compression was initiated before induction of anaesthesia. In the control group, pneumatic leg compression was initiated 20 min after anaesthesia induction. The primary outcome was the incidence of post-induction hypotension in these groups. Post-induction hypotension was defined as systolic blood pressure < 90 mmHg during the first 20 min after induction. Haemodynamic variables and area under the curve of post-induction systolic blood pressure over time were assessed. Complications associated with pneumatic leg compression were recorded, including: peripheral neuropathy; compartment syndrome; extensive bullae beneath the leg sleeves; and pulmonary thromboembolism. The incidence of post-induction hypotension decreased in the pneumatic leg compression group compared with that in the control group; 5 (10%) vs. 29 (58%), respectively, p < 0.001. In the pneumatic leg compression group, the lowest systolic, diastolic and mean blood pressures 20 min after induction of anaesthesia were significantly greater than the control group. Pneumatic leg compression resulted in an increased area under the curve of systolic blood pressure in the first 20 min after induction, p = 0.001. There were no pneumatic leg compression-related complications. Pneumatic leg compression reduced post-induction hypotension in elderly patients undergoing robot-assisted laparoscopic prostatectomy, suggesting that it is an effective and safe intervention to prevent post-induction hypotension among elderly patients undergoing general anaesthesia. 相似文献
10.
气体信号分子可作用于肺动脉高压、高血压及动脉粥样硬化等多种心血管疾病。随着基础和临床研究的开展, 以及新型气体信号分子释放剂的出现, 采用气体信号分子治疗肺动脉高压显示出巨大的临床应用前景。该文对气体信号分子与肺动脉高压的相关研究进展进行了综述。 相似文献