全文获取类型
收费全文 | 7312篇 |
免费 | 463篇 |
国内免费 | 43篇 |
专业分类
耳鼻咽喉 | 63篇 |
儿科学 | 173篇 |
妇产科学 | 104篇 |
基础医学 | 1087篇 |
口腔科学 | 124篇 |
临床医学 | 516篇 |
内科学 | 1588篇 |
皮肤病学 | 391篇 |
神经病学 | 525篇 |
特种医学 | 314篇 |
外科学 | 1181篇 |
综合类 | 162篇 |
一般理论 | 4篇 |
预防医学 | 365篇 |
眼科学 | 263篇 |
药学 | 327篇 |
中国医学 | 28篇 |
肿瘤学 | 603篇 |
出版年
2024年 | 11篇 |
2023年 | 62篇 |
2022年 | 113篇 |
2021年 | 203篇 |
2020年 | 137篇 |
2019年 | 175篇 |
2018年 | 195篇 |
2017年 | 167篇 |
2016年 | 218篇 |
2015年 | 235篇 |
2014年 | 331篇 |
2013年 | 304篇 |
2012年 | 556篇 |
2011年 | 515篇 |
2010年 | 284篇 |
2009年 | 263篇 |
2008年 | 388篇 |
2007年 | 367篇 |
2006年 | 335篇 |
2005年 | 389篇 |
2004年 | 330篇 |
2003年 | 271篇 |
2002年 | 303篇 |
2001年 | 236篇 |
2000年 | 224篇 |
1999年 | 180篇 |
1998年 | 68篇 |
1997年 | 49篇 |
1996年 | 48篇 |
1995年 | 47篇 |
1994年 | 38篇 |
1993年 | 25篇 |
1992年 | 78篇 |
1991年 | 76篇 |
1990年 | 71篇 |
1989年 | 80篇 |
1988年 | 91篇 |
1987年 | 64篇 |
1986年 | 50篇 |
1985年 | 44篇 |
1984年 | 35篇 |
1983年 | 39篇 |
1982年 | 7篇 |
1981年 | 10篇 |
1980年 | 6篇 |
1979年 | 24篇 |
1978年 | 10篇 |
1977年 | 16篇 |
1974年 | 9篇 |
1969年 | 6篇 |
排序方式: 共有7818条查询结果,搜索用时 9 毫秒
91.
This study demonstrates the utility of thermo-regulated phase separable alumina/camphene suspensions containing poly(methyl methacrylate) (PMMA) microspheres as porogens for the production of multi-scale porosity structures. The homogeneous suspension prepared at 60 °C could undergo phase separation during freezing at room temperature. This process resulted in the 3D networks of camphene crystals and alumina walls containing PMMA microspheres. As a consequence, relatively large dendritic pores with several tens of microns size could be created as the replica of frozen camphene crystals. In addition, after the removal of PMMA microspheres via heat-treatment, micron-sized small spherical pores could be generated in alumina walls. As the PMMA content with respect to the alumina content increased from 0 vol% to 40 vol%, while the camphene content in the suspensions was kept constant (70 vol%), the overall porosity increased from 45.7 ± 0.5 vol% to 71.4 ± 0.5 vol%. This increase in porosity is attributed to an increase in the fraction of spherical pores in the alumina walls. Thus, compressive strength decreased from 153 ± 18.3 MPa to 33 ± 7.2 MPa. In addition, multi-scale porosity alumina objects with a honeycomb structure comprising periodic hexagonal macrochannels surrounded by dual-scale porosity walls were constructed using a 3D plotting technique. 相似文献
92.
Subramanyam Vankadara Monique Danielle Dawson Jia Yi Fong Qin Yao Oh Qi An Ang Boping Liu Hong Yun Chang Judice Koh Xiaoying Koh Qian Wen Tan Joma Joy Cheng San Brian Chia 《ACS medicinal chemistry letters》2022,13(8):1345
The SARS-CoV-2 pandemic is currently causing an unprecedented global health emergency since its emergence in December 2019. In December 2021, the FDA granted emergency use authorization to nirmatrelvir, a SARS-CoV-2 main protease inhibitor, for treating infected patients. This peptidomimetic is designed with a nitrile warhead, which forms a covalent bond to the viral protease. Herein, we investigate nirmatrelvir analogs with different warheads and their inhibitory activities. In addition, antiviral activities against human alphacoronavirus 229E was also investigated along with a cell-based assay. We discovered that the hydroxymethylketone and ketobenzothiazole warheads were equipotent to the nitrile warhead, suggesting that these analogs can also be used for treating coronavirus infections. 相似文献
93.
Jongmin Won Jong Won Hong Mi Jung Kim In-sik Yun Woo Yeol Baek Won Jai Lee Dae Hyun Lew Yoon Woo Koh Se-Heon Kim 《Yonsei medical journal》2022,63(8):759
PurposeRobotic head and neck surgery is widespread nowadays. However, in the reconstruction field, the use of robotic operations is not. This article aimed to examine methodologies for conventional head and neck reconstruction after robotic tumor surgery in an effort to obtain further options for future reconstruction manipulations.Materials and MethodsA retrospective review of all patients who received head and neck robot surgery and conventional reconstructive surgery between October 2016 and September 2021.ResultsIn total, 53 cases were performed. 67.9% of the tumors were greater than 4 cm. Regarding defect size, 47.2% of the lesions were greater than 8 cm. In terms of TNM stage, stage 3 disease was recorded in 26.4% and stage 4 in 52.8%. To make a deep and narrow field wider, we changed the patient’s posture in pre-op field, additional dissection was done. We used radial forearm flap mostly (62.2%).ConclusionConventional head and neck reconstruction after robotic ENT cancer surgery is possible. One key step is to secure additional space in the deep and narrow space left after robotic surgery. For this, we opted for a radial forearm flap mostly. This can be performed as a bridgehead to perform robotic head and neck reconstruction. 相似文献
94.
Masahito Hitosugi Eiko Kagesaw Takahiro Narikaw Mami Nakamur Mirae Koh Shinobu Hattori 《中华创伤杂志(英文版)》2021,24(2):83-87
Purpose: To determine the trends with fatally or otherwise injured pedestrians lying on the road and the relationship to hit-and-run incidents in Japan.
Methods: We extracted data for 2012e2016 from the records of the Institute for Traffic Accident Research and Data Analysis, Japan, a nationwide traffic accident database. All the injured and fatally injured pedestrians were selected. We examined the levels of pedestrian injury, vehicle speed immediately before the collision, whether or not the pedestrian was lying on the road, and hit-and-run incidents. Chi-square test was employed to make a statistical comparison between the two groups.
Results: The database contained data on 286,383 pedestrian casualties and 7256 fatalities; 8.3% of fatalities (602 persons) and 0.6% of casualties (1827 persons) involved pedestrians lying on the road. The rates of fatalities and severe injuries were significantly higher for pedestrians who were lying on the road than for those who were not. Hit-and-run incidents were evident in 4.0% of casualties and 7.3% of fatalities. The rate of hit-and-run cases was also significantly higher among pedestrians who were lying on the road. Among fatally injured pedestrians not lying on the road, the rates with speeds of 30 km/h did not differ significantly between hit-and-run and other cases. However, when the pedestrians were lying
on the road, the rate was significantly increased in hit-and-run cases.
Conclusion: This is the first report to focus on pedestrians lying on the road and being involved in hitand-run incidents. In addition to preventing hit-and-run incidents, prevention of pedestrians lying on
the road could also decrease fatalities. 相似文献
95.
Yun-Hee Rhee Soo-Jin Jeong Hyo-Jeong Lee Hyo-Jung Lee Wonil Koh Ji Hoon Jung Sun-Hee Kim Kim Sung-Hoon 《BMC cancer》2012,12(1):28
Background
Ergosterol peroxide (EP) derived from edible mushroom has been shown to exert anti-tumor activity in several cancer cells. In the present study, anti-angiogenic activity of EP was investigated with the underlying molecular mechanisms in human multiple myeloma U266 cells. 相似文献96.
97.
98.
99.
100.
Purpose: Lengthy hospitalization places a burden on patients and healthcare resources. However, the factors affecting the length of hospital stay (LHoS) and length of emergency room stay (LERS) in non-fatal bicycle accidents are currently unclear. We investigated these factors to inform efforts to minimize hospitalization.
Methods: We performed a retrospective analysis of data from non-fatal injured bicyclists admitted to the Emergency and Critical Care Center at Kyoto Medical Center between January 2012 and December 2016. We measured LHoS, LERS, mechanism of injury, head injury prevalence, polytrauma, operations performed, injury severity score (ISS), abbreviated injury scale (AIS) score, maximum AIS score, and trauma and injury severity score probability of survival. We conducted multiple regression analysis to determine predictors of LHoS and LERS.
Results: Within the study period, 82 victims met the inclusion and exclusion criteria and were included. Mean age was (46.0 ± 24.7) years. Overall mean LHoS was (16.8 ± 25.2) days, mean LERS was (10.6 ± 14.7) days, median ISS was 9 (interquartile range (IQR): 3-16), median maximum AIS was 3 (IQR: 1-4), and median trauma and injury severity score probability of survival was 98.0% (IQR: 95.5%-99.6%). Age, maximum AIS, ISS, and prevalence of surgery were significantly greater in long LHoS and LERS group compared with short LHoS and LERS group (p < 0.05). Performance of surgery independently explained LHoS (p = 0.0003) and ISS independently explained LERS (p = 0.0009).
Conclusion: Surgery was associated with long hospital stays and ISS was associated with long emergency room stays. To improve the quality life of the bicyclists, preventive measures for reducing injury severity or avoiding injuries needing operation are required. 相似文献