全文获取类型
收费全文 | 23679篇 |
免费 | 1414篇 |
国内免费 | 259篇 |
专业分类
耳鼻咽喉 | 380篇 |
儿科学 | 271篇 |
妇产科学 | 279篇 |
基础医学 | 3795篇 |
口腔科学 | 372篇 |
临床医学 | 1877篇 |
内科学 | 4718篇 |
皮肤病学 | 764篇 |
神经病学 | 1772篇 |
特种医学 | 1660篇 |
外科学 | 3381篇 |
综合类 | 149篇 |
一般理论 | 16篇 |
预防医学 | 779篇 |
眼科学 | 555篇 |
药学 | 2114篇 |
中国医学 | 310篇 |
肿瘤学 | 2160篇 |
出版年
2024年 | 19篇 |
2023年 | 162篇 |
2022年 | 522篇 |
2021年 | 857篇 |
2020年 | 369篇 |
2019年 | 624篇 |
2018年 | 732篇 |
2017年 | 576篇 |
2016年 | 930篇 |
2015年 | 1210篇 |
2014年 | 1432篇 |
2013年 | 1466篇 |
2012年 | 2234篇 |
2011年 | 2117篇 |
2010年 | 1324篇 |
2009年 | 1080篇 |
2008年 | 1470篇 |
2007年 | 1387篇 |
2006年 | 1254篇 |
2005年 | 1168篇 |
2004年 | 960篇 |
2003年 | 800篇 |
2002年 | 668篇 |
2001年 | 338篇 |
2000年 | 285篇 |
1999年 | 211篇 |
1998年 | 128篇 |
1997年 | 107篇 |
1996年 | 78篇 |
1995年 | 79篇 |
1994年 | 63篇 |
1993年 | 55篇 |
1992年 | 95篇 |
1991年 | 86篇 |
1990年 | 56篇 |
1989年 | 47篇 |
1988年 | 52篇 |
1987年 | 44篇 |
1986年 | 44篇 |
1985年 | 31篇 |
1984年 | 14篇 |
1983年 | 27篇 |
1982年 | 19篇 |
1981年 | 15篇 |
1980年 | 11篇 |
1979年 | 12篇 |
1978年 | 10篇 |
1973年 | 11篇 |
1972年 | 10篇 |
1971年 | 11篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
Yeon Soo Kim Jae Won Choi Ju-Kyeong Park Hyun Jung Kim 《Acta oto-laryngologica》2015,135(12):1311-1318
Conclusion: The results of the present investigation suggest that modification of HA could improve efficiency and durability in augmentation laryngoplasty. Objectives: Injection laryngoplasty (IL) is one of the most suitable options for treatment of glottic insufficiency, which is caused by vocal fold (VF) paralysis, atrophy, or scarring. Hyaluronic acid (HA) is a widely used material for VF injection. This study was intended to evaluate the durability and efficiency of HA of different particle sizes for VF augmentation. Methods: Three types of HA, Restylane®, monophasic low-viscosity, and unequal particle-sized middle-viscosity HA were injected into the left VF of three groups with eight rabbits each. Results: After 6 and 10 weeks, the injected site was evaluated endoscopically, histologically, radiologically, and functionally. None of the 24 rabbits showed any signs of respiratory distress. Computed tomography (CT) images and endoscopic evaluation revealed sufficient augmented volume of the injected VF in all treated groups 6 weeks after the injection. Histological data at week 10 showed that unequal particle-sized HA did not migrate from its original injection site, while other HAs migrated to the periphery of the arytenoid cartilage. Videokymographic analysis showed more favorable vibrations of unequal particle-sized HA injected VF mucosa 10 weeks post-injection, compared to the other treatment groups. 相似文献
92.
93.
94.
Ahyoung Kim Soo Yeon Lim Jung Hyun Park Jin-Seok Chung Hyeonsik Cheong Changhyun Ko Jong-Gul Yoon Sang Mo Yang 《RSC advances》2022,12(36):23039
Vanadium dioxide (VO2) is one of the extensively studied strongly correlated oxides due to its intriguing insulator–metal transition near room temperature. In this work, we investigated temperature-dependent nanoscale conduction in an epitaxial VO2 film grown on an Al2O3 substrate using conductive-atomic force microscopy (C-AFM). We observed that only the regions near the grain boundaries are conductive, producing intriguing donut patterns in C-AFM images. Such donut patterns were observed in the entire measured temperature range (300–355 K). The current values near the grain boundaries increased by approximately two orders of magnitude with an increase in the temperature, which is consistent with the macroscopic transport data. The spatially-varied conduction behavior is ascribed to the coexistence of different monoclinic phases, i.e., M1 and M2 phases, based on the results of temperature-dependent Raman spectroscopy. Furthermore, we investigated the conduction mechanism in the relatively conductive M1 phase regions at room temperature using current–voltage (I–V) spectroscopy and deep data analysis. Bayesian linear unmixing and k-means clustering showed three distinct types of conduction behavior, which classical C-AFM cannot resolve. We found that the conduction in the M1 phase regions can be explained by the Poole–Frenkel mechanism. This work provides deep insight into IMT behavior in the epitaxial VO2 thin film at the nanoscale, especially the coexistence and evolution of the M1 and M2 phases. This work also highlights that I–V spectroscopy combined with deep data analysis is very powerful in investigating local transport in complex oxides and various material systems.We investigated temperature-dependent nanoscale conduction in an epitaxial VO2 film grown on an Al2O3 substrate using conductive-atomic force microscopy and deep data analysis. 相似文献
95.
96.
STUDY OBJECTIVE: To examine the incidence, characteristics, and treatment of ureteral injuries during classic intrafascial supracervical hysterectomy for benign gynecologic diseases. DESIGN: Retrospective study (Canadian Task Force classification II-3). SETTING: Department of obstetrics and gynecology, university teaching hospital. PATIENTS: A total of 1163 women with benign gynecologic diseases. INTERVENTIONS: Classic intrafascial supracervical hysterectomy. MEASUREMENTS AND MAIN RESULTS: A retrospective chart review was conducted to determine the rate of ureteral injury. Four cases of ureteral injuries occurred among the 1163 classic intrafascial supracervical hysterectomy procedures (0.34%). Ureteral injury occurred during peritoneal dissection in 1 case, which was treated immediately with laparoscopy. In 2 cases, ureteral injuries were recognized by watery vaginal discharge several days after the operation and were treated with laparotomy procedures. Ureteral injury was not detected postoperatively in another case, resulting in a laparoscopic nephrectomy caused by a nonfunctioning kidney 3 years after the initial operation. The predisposing factors for ureteral injury were adhesion as a result of endometriosis, and earlier surgery in which the normal pelvic anatomy was distorted. CONCLUSION: The incidence of ureteral injury during classic intrafascial supracervical hysterectomy as noted in this study is 0.34%. Postoperative cases were associated with high morbidity. Early detection of ureteral injury is crucial for appropriate management as intraoperative diagnosis and repair of the injury then has fewer consequences and less serious complications than postoperative cases. 相似文献
97.
Thuong PT Lee CH Dao TT Nguyen PH Kim WG Lee SJ Oh WK 《Journal of natural products》2008,71(10):1775-1778
Phytochemical study on a methanol-soluble extract of the leaves of persimmon (Diospyros kaki) resulted in the isolation of two new ursane-type triterpenoids, 3alpha,19alpha-dihydroxyurs-12,20(30)-dien-24,28-dioic acid (1) and 3alpha,19alpha-dihydroxyurs-12-en-24,28-dioic acid (2), together with 12 known ursane- and oleanane-type triterpenoids (3-14). Triterpenoids with a 3beta-hydroxy group were found to inhibit protein tyrosine phosphatase 1B (PTP1B) activity, with IC50 values ranging from 3.1+/-0.2 to 18.8+/-1.3 microM, whereas those with a 3alpha-hydroxy moiety were not active. 相似文献
98.
99.
100.