全文获取类型
收费全文 | 4125篇 |
免费 | 255篇 |
国内免费 | 20篇 |
专业分类
耳鼻咽喉 | 51篇 |
儿科学 | 147篇 |
妇产科学 | 122篇 |
基础医学 | 422篇 |
口腔科学 | 52篇 |
临床医学 | 374篇 |
内科学 | 1026篇 |
皮肤病学 | 49篇 |
神经病学 | 390篇 |
特种医学 | 118篇 |
外科学 | 648篇 |
综合类 | 95篇 |
一般理论 | 1篇 |
预防医学 | 301篇 |
眼科学 | 101篇 |
药学 | 263篇 |
中国医学 | 8篇 |
肿瘤学 | 232篇 |
出版年
2023年 | 23篇 |
2022年 | 16篇 |
2021年 | 112篇 |
2020年 | 96篇 |
2019年 | 139篇 |
2018年 | 164篇 |
2017年 | 104篇 |
2016年 | 120篇 |
2015年 | 135篇 |
2014年 | 186篇 |
2013年 | 229篇 |
2012年 | 339篇 |
2011年 | 370篇 |
2010年 | 178篇 |
2009年 | 177篇 |
2008年 | 285篇 |
2007年 | 293篇 |
2006年 | 256篇 |
2005年 | 263篇 |
2004年 | 220篇 |
2003年 | 221篇 |
2002年 | 176篇 |
2001年 | 21篇 |
2000年 | 18篇 |
1999年 | 21篇 |
1998年 | 18篇 |
1997年 | 11篇 |
1996年 | 8篇 |
1995年 | 12篇 |
1994年 | 10篇 |
1993年 | 9篇 |
1992年 | 13篇 |
1991年 | 4篇 |
1989年 | 4篇 |
1988年 | 12篇 |
1986年 | 5篇 |
1984年 | 5篇 |
1981年 | 4篇 |
1980年 | 10篇 |
1979年 | 7篇 |
1978年 | 4篇 |
1976年 | 4篇 |
1974年 | 4篇 |
1972年 | 4篇 |
1971年 | 4篇 |
1960年 | 6篇 |
1959年 | 6篇 |
1958年 | 5篇 |
1944年 | 3篇 |
1928年 | 3篇 |
排序方式: 共有4400条查询结果,搜索用时 203 毫秒
1.
2.
Virginia Hill Rice Thomas N. Templin Janet K. Harden Elizabeth S. Jenuwine Ibrahim Abdulhamid Adnan Hammad 《The Journal of adolescent health》2019,64(3):333-339
Purpose
The purpose of this study was to determine the prevalence of respiratory and/or physical fitness health problems in adolescent (ages 18–21) water pipe (WP) smokers (with or without cigarette smoking), cigarette-only smokers, and nonsmokers.Methods
A comparative four-group study design was used to recruit a non–probability sample of 153 WP smokers only, 103 cigarette smokers only, and 102 cigarette+WP smokers along with 296 nonsmokers. Our hypothesis was that youth who smoked WPs and/or cigarettes would report more respiratory problems and/or poorer physical fitness than those who did not smoke.Results
The results showed that coughs were significantly associated with smoking in all three of the smoking groups (p < .05). Cigarette-only smokers reported the most adverse outcomes with more wheezing, difficulty breathing, and less ability to exercise without shortness of breath. A dose-response analysis showed similar patterns of adverse health effects for both WP and cigarette smokers. The combined use of both products was not appreciably worse than smoking one product alone. This could be due to cigarette+WP smokers' reporting using less of the respective products when only one product was smoked.Conclusions
Even during the adolescent years, WP and/or cigarette smoking youth experienced reportable negative health effects. 相似文献3.
Sarina A. Piha-Paul Do-Youn Oh Makoto Ueno David Malka Hyun Cheol Chung Adnan Nagrial Robin K. Kelley Willeke Ros Antoine Italiano Kazuhiko Nakagawa Hope S. Rugo Filippo de Braud Andrea Iolanda Varga Aaron Hansen Hui Wang Suba Krishnan Kevin G. Norwood Toshihiko Doi 《International journal of cancer. Journal international du cancer》2020,147(8):2190-2198
We present data from patients with advanced biliary tract cancer (BTC) receiving pembrolizumab in the KEYNOTE-158 (NCT02628067; phase 2) and KEYNOTE-028 (NCT02054806; phase 1b) studies. Eligible patients aged ≥18 years from both studies had histologically/cytologically confirmed incurable BTC that progressed after standard treatment regimen(s), measurable disease per Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1, Eastern Cooperative Oncology Group performance status 0/1, and no prior immunotherapy. Programmed death ligand 1 (PD-L1)-positive tumors were required for eligibility in KEYNOTE-028 only. Patients received pembrolizumab 200 mg every three weeks (KEYNOTE-158) or 10 mg/kg every two weeks (KEYNOTE-028) for ≤2 years. Primary efficacy endpoint was objective response rate (ORR) by RECIST v1.1. Response assessed by independent central review is reported. KEYNOTE-158 enrolled 104 patients and KEYNOTE-028 enrolled 24 patients. Median (range) follow-up was 7.5 months (0.6-34.3) in KEYNOTE-158 and 5.7 months (0.6-55.4) in KEYNOTE-028. In KEYNOTE-158, ORR was 5.8% (6/104; 95% CI, 2.1%-12.1%); median duration of response (DOR) was not reached (NR) (range, 6.2-26.6+ months). Median (95% CI) OS and PFS were 7.4 (5.5-9.6) and 2.0 (1.9-2.1) months. Among PD-L1-expressers (n = 61) and PD-L1-nonexpressers (n = 34), respectively, ORR was 6.6% (4/61) and 2.9% (1/34). In KEYNOTE-028, ORR was 13.0% (3/23; 95% CI, 2.8%-33.6%); median DOR was NR (range, 21.5-53.2+ months). Median (95% CI) OS and PFS were 5.7 (3.1-9.8) and 1.8 (1.4-3.1) months. Grade 3 to 5 treatment-related adverse events occurred in 13.5% of patients in KEYNOTE-158 (no grade 4; grade 5 renal failure, n = 1) and 16.7% in KEYNOTE-028 (no grade 4/5). In summary, pembrolizumab provides durable antitumor activity in 6% to 13% of patients with advanced BTC, regardless of PD-L1 expression, and has manageable toxicity. 相似文献
4.
5.
Joseph O. Lloyd Kim I. Chisholm Beatrice Oehle Martyn G. Jones Bright N. Okine Adnan AL-Kaisy Giorgio Lambru Stephen B. McMahon Anna P. Andreou 《Neurotherapeutics》2020,17(4):1973
Single-pulse transcranial magnetic stimulation (sTMS) of the occipital cortex is an effective migraine treatment. However, its mechanism of action and cortical effects of sTMS in migraine are yet to be elucidated. Using calcium imaging and GCaMP-expressing mice, sTMS did not depolarise neurons and had no effect on vascular tone. Pre-treatment with sTMS, however, significantly affected some characteristics of the cortical spreading depression (CSD) wave, the correlate of migraine aura. sTMS inhibited spontaneous neuronal firing in the visual cortex in a dose-dependent manner and attenuated l-glutamate-evoked firing, but not in the presence of GABAA/B antagonists. In the CSD model, sTMS increased the CSD electrical threshold, but not in the presence of GABAA/B antagonists. We first report here that sTMS at intensities similar to those used in the treatment of migraine, unlike traditional sTMS applied in other neurological fields, does not excite cortical neurons but it reduces spontaneous cortical neuronal activity and suppresses the migraine aura biological substrate, potentially by interacting with GABAergic circuits.Electronic supplementary materialThe online version of this article (10.1007/s13311-020-00879-6) contains supplementary material, which is available to authorized users.Key Words: Migraine, transcranial magnetic stimulation, GABA, glutamate, cortex 相似文献
6.
Susanne G Warner Adnan A Alseidi Johnny Hong Timothy M Pawlik Rebecca M Minter 《HPB : the official journal of the International Hepato Pancreato Biliary Association》2015,17(9):785-790
BackgroundHepatopancreatobiliary (HPB) surgery fellowship training has multiple paths. Prospective trainees and employers must understand the differences between training pathways. This study examines self-reported fellowship experiences and current scope of practice across three pathways.MethodsAn online survey was disseminated to 654 surgeons. These included active Americas Hepato-Pancreato-Biliary Association (AHPBA) members and recent graduates of HPB, transplant–HPB and HPB–heavy surgical oncology fellowships.ResultsA total of 416 (64%) surgeons responded. Most respondents were male (89%) and most were practising in an academic setting (83%). 290 (70%) respondents underwent formal fellowship training. Although fellowship experiences varied, current practice was largely similar. Minimally invasive surgery (MIS) and ultrasound were the most commonly identified areas of training deficiencies and were, respectively, cited as such by 47% and 34% of HPB-, 49% and 50% of transplant-, and 52% and 25% of surgical oncology-trained respondents. Non-HPB cases performed in current practice included gastrointestinal (GI) and general surgery cases (56% and 49%, respectively) for HPB-trained respondents, transplant and general surgery cases (87% and 21%, respectively) for transplant-trained respondents, and GI surgery and non-HPB surgical oncology cases (70% and 28%, respectively) for surgical oncology-trained respondents.ConclusionsFellowship training in HPB surgery varies by training pathway. Training in MIS and ultrasound is deficient in each pathway. The ultimate scope of non-transplant HPB practice appears similar across training pathways. Thus, training pathway choice is best guided by the training experience desired and non-HPB components of anticipated practice. 相似文献
7.
8.
9.
10.
Shereen M. Assaf Mai Subhi Khanfar Ahmed Bassam Farhan Iyad Said Rashid Adnan Ali Badwan 《Pharmaceutical development and technology》2019,24(6):761-774
It was aimed to investigate the compressibility, compactibility, powder flow and tablet disintegration of a new excipient comprising magnesium (Mg) silicate co-processed (5%–85% w/w) onto chitin, microcrystalline cellulose (MCC) and starch as the hydrophilic polymers of interest. Initially, the mechanism of tablet disintegration was studied by measuring water infiltration rate, moisture sorption, swelling capacity and hydration ability. Moreover, the powders compression behavior was carried out by applying Kawakita model of compression analysis in addition to porosity and radial tensile strength measurements. In vitro drug release of compacts made of 400?mg ibuprofen and 300?mg of the hydrophilic polymers containing 30% w/w Mg silicate co-precipitate was investigated in phosphate buffer (pH 7.8). This work demonstrated that the incorporation of Mg silicate to the hydrophilic polymers lead to the improvement of powder flowability, compactibility, stability (with regard to storage conditions), compacts crushing strength, and disintegration time in addition to faster drug release. The overall findings are practically advantageous in the context of finding a low cost and multifunctional co-processed excipient of natural origins. 相似文献