全文获取类型
收费全文 | 324187篇 |
免费 | 29083篇 |
国内免费 | 22882篇 |
专业分类
耳鼻咽喉 | 2989篇 |
儿科学 | 3422篇 |
妇产科学 | 4925篇 |
基础医学 | 39955篇 |
口腔科学 | 5493篇 |
临床医学 | 45260篇 |
内科学 | 49706篇 |
皮肤病学 | 3082篇 |
神经病学 | 18361篇 |
特种医学 | 11986篇 |
外国民族医学 | 213篇 |
外科学 | 33217篇 |
综合类 | 49844篇 |
现状与发展 | 76篇 |
一般理论 | 20篇 |
预防医学 | 19614篇 |
眼科学 | 9572篇 |
药学 | 32793篇 |
334篇 | |
中国医学 | 17430篇 |
肿瘤学 | 27860篇 |
出版年
2024年 | 1002篇 |
2023年 | 5013篇 |
2022年 | 13045篇 |
2021年 | 16392篇 |
2020年 | 12036篇 |
2019年 | 10893篇 |
2018年 | 11410篇 |
2017年 | 9915篇 |
2016年 | 9355篇 |
2015年 | 14350篇 |
2014年 | 17798篇 |
2013年 | 15340篇 |
2012年 | 22800篇 |
2011年 | 25809篇 |
2010年 | 15904篇 |
2009年 | 12248篇 |
2008年 | 17013篇 |
2007年 | 17015篇 |
2006年 | 17048篇 |
2005年 | 16776篇 |
2004年 | 10665篇 |
2003年 | 9758篇 |
2002年 | 8440篇 |
2001年 | 7465篇 |
2000年 | 8276篇 |
1999年 | 9017篇 |
1998年 | 5475篇 |
1997年 | 5500篇 |
1996年 | 4332篇 |
1995年 | 3922篇 |
1994年 | 3213篇 |
1993年 | 2097篇 |
1992年 | 2827篇 |
1991年 | 2415篇 |
1990年 | 2117篇 |
1989年 | 1861篇 |
1988年 | 1563篇 |
1987年 | 1352篇 |
1986年 | 1107篇 |
1985年 | 912篇 |
1984年 | 526篇 |
1983年 | 373篇 |
1982年 | 242篇 |
1981年 | 238篇 |
1980年 | 188篇 |
1979年 | 221篇 |
1978年 | 82篇 |
1977年 | 89篇 |
1974年 | 102篇 |
1973年 | 83篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
81.
82.
F Y Hsu C J Tung J C Chen Y L Wang H C Huang R G Zamenhof 《Applied radiation and isotopes》2004,61(5):881-885
In 1998, an epithermal neutron test beam was designed and constructed at the Tsing Hua Open-Pool Reactor (THOR) for the purpose of preliminary dosimetric experiments in boron neutron capture therapy (BNCT). A new epithermal neutron beam was designed at this facility, and is currently under construction, with clinical trials targeted in late 2004. Depth dose-rate distributions for the THOR BNCT test beam have been measured by means of activation foil and dual ion chamber techniques. Neutron and structure-induced gamma spectra measured at the test beam exit were configured into a source function for the Monte Carlo-based treatment planning code NCTPlan. Dose-rate scaling factors (DRSFs) were determined to normalize computationally derived dose-rate distributions with experimental measurements in corresponding mathematical and physical phantoms, and to thus enable accurate treatment planning using the NCTPlan code. A similar approach will be implemented in characterizing the new THOR epithermal beam in preparation for clinical studies. This paper reports the in-phantom calculated and experimental dosimetry comparisons and derived DRSFs obtained with the THOR test beam. 相似文献
83.
84.
BACKGROUND AND PURPOSE: Health-related quality of life (HRQOL) is primarily an assessment of how domains of life are affected by health. This study investigated the factors influencing HRQOL of Taiwanese patients with bronchial asthma. METHODS: A cross-sectional study was conducted to assess the factors influencing HRQOL. The sample consisted of 242 outpatients with bronchial asthma. The Chinese language version of the St. George's Respiratory Questionnaire was used to measure HRQOL. Data were analyzed using simple regression and multiple regression. RESULTS: Age, marital status, level of education, asthma severity, peak expiratory flow, and previous hospital admissions were found to be predictors of HRQOL. Gender, duration of disease, and history of emergency visits were not correlated with HRQOL. The variables entered in the HRQOL model accounted for 17.4% of the total variance (adjusted R(2)). The regression coefficients indicated that the mean scores increased 7.68 in patients with moderate to severe disease severity, and increased 7.34 in patients with a history of hospital admissions. The mean scores decreased 7.60 in married patients. CONCLUSION: This study found that marital status, asthma severity, and history of hospital admissions were major predictors of HRQOL in Taiwanese patients with bronchial asthma. 相似文献
85.
As an ongoing effort to elucidate the mechanisms involved in the calcium-dependent fertility regulation process, the viscoelastic properties of the mucus obtained from lamb cervix and human semen, as well as their water and total protein contents after exposure to EDTA, a chelating agent, or Nonoxynol-9 (N-9), a spermicidal agent, were examined. The viscosity was measured using a Cone Plate Digital Viscometer, while the water and total protein contents were determined by the lyophilization process and the Lowry method, respectively. The significant changes in the rheological properties of mucus, such as its viscosity and the water content, upon exposure to EDTA were demonstrated. The viscosity of cervical mucus and human semen were significantly increased by EDTA treatment (as compared to the controls): lamb cervical mucus (2.9 ± 0.3 vs. 2.2 ± 0.3 cps) and human semen (5.0 ± 0.3 vs. 4.3 ± 0.3 cps), respectively. The hydration rate was decreased by EDTA treatment as compared with the control (93.6 ± 0.7 vs. 96.8 ± 0.8%). Among tested samples, the reduction in the percentage of sperm penetration through the cervical mucus was the highest in the mucus containing EDTA, which had the lowest water content (93.6 ± 0.7%), indicating that there is a positive relationship between the hydration rate of the cervical mucus and its ability to permit the penetration of spermatozoa. This result indicates that spermicidal activity exerted by high concentrations of EDTA is in part due to its effect on the rheological properties of cervical mucus or semen. 相似文献
86.
Lin Shang-ze林尚泽and Wang Gui-fa王贵发Department of Otorhinolarrjngology Affiliated Hospital of GuiyangMedical College Guiyang 《中华医学杂志(英文版)》1986,99(7):602-603
Since the beginning of this century, trans-
naso-sphenoidal resection of the pituitary fossa
tumors has been widely used clinically. It has
more merits than other operative approaches
used before. In China it has been adopted by
both ENT doctors and neurosurgeons since 1959.1
In order to afford some relevant anatomical
data, we measured 137 adult sagittal plane
skulls with distinct landmarks. 相似文献
87.
Lianjun Lu Jinling Wang Jianhua Qiu Weiguo Huang Shunli Liu Shengxi Wu 《中华耳鼻咽喉科杂志》2002,37(6):428-431
OBJECTIVE: To examine the distribution of rat facial motoneurons contributing different branches under normal situation and when nerve reinnervation occurred following facial nerve axotomy. METHODS: The normal distribution of motoneurons innervated both buccal and marginal mandibular branches and its reorganization after facial nerve reinnervation was observed using retrograde labeling with fluorescein. RESULTS: Under normal situation, the motoneurons contributing buccall and marginal mandibular branches were primarily distributed in the intermedial and lateral subnucleus in facial nucleus and almost completely overlapped. The two types labeled neurons organized closely, but there were no double-labeled neurons. Although the motoneurons contributing buccall and marginal mandibular branches were primarily overlapped 4 month post-anastomosis, the number of the labeled neurons obviously decreased and the organization got more scattered. There were 10% of buccall branches, 5% of marginal mandibular motoneurons in the dorsal subnuleus, 1% of buccall and 4% of marginal mandibular in dorsal ventral and medial subnucleus. The distribution pattern of the motoneurons 6 month post-anastomosis was similar to that of 4 month post-anastomosis, but the number of the labeled neurons increased, and there were 1%-2% double-labeled neurons. CONCLUSION: The distribution pattern of motoneurons innervated both buccal and marginal mandibular branches indicates that it should exist wide-spread communicating branches, and its reorganization after facial nerve reinnervation suggests that misdirected regeneration occurs among motoneurons innervating different branches. 相似文献
88.
89.
90.
The effect of lowered estradiol levels on periodontal tissue 总被引:1,自引:0,他引:1
W Z Wang 《中华口腔医学杂志》1987,22(3):146-9, 190