全文获取类型
收费全文 | 5025篇 |
免费 | 269篇 |
国内免费 | 28篇 |
专业分类
耳鼻咽喉 | 47篇 |
儿科学 | 94篇 |
妇产科学 | 76篇 |
基础医学 | 554篇 |
口腔科学 | 165篇 |
临床医学 | 465篇 |
内科学 | 1115篇 |
皮肤病学 | 87篇 |
神经病学 | 402篇 |
特种医学 | 279篇 |
外科学 | 714篇 |
综合类 | 32篇 |
一般理论 | 4篇 |
预防医学 | 359篇 |
眼科学 | 75篇 |
药学 | 348篇 |
中国医学 | 2篇 |
肿瘤学 | 504篇 |
出版年
2023年 | 36篇 |
2022年 | 79篇 |
2021年 | 132篇 |
2020年 | 68篇 |
2019年 | 109篇 |
2018年 | 114篇 |
2017年 | 83篇 |
2016年 | 82篇 |
2015年 | 93篇 |
2014年 | 123篇 |
2013年 | 176篇 |
2012年 | 196篇 |
2011年 | 231篇 |
2010年 | 110篇 |
2009年 | 104篇 |
2008年 | 198篇 |
2007年 | 199篇 |
2006年 | 209篇 |
2005年 | 205篇 |
2004年 | 215篇 |
2003年 | 201篇 |
2002年 | 219篇 |
2001年 | 183篇 |
2000年 | 220篇 |
1999年 | 162篇 |
1998年 | 68篇 |
1997年 | 52篇 |
1996年 | 38篇 |
1995年 | 49篇 |
1994年 | 35篇 |
1993年 | 28篇 |
1992年 | 127篇 |
1991年 | 107篇 |
1990年 | 95篇 |
1989年 | 117篇 |
1988年 | 77篇 |
1987年 | 77篇 |
1986年 | 90篇 |
1985年 | 86篇 |
1984年 | 62篇 |
1983年 | 45篇 |
1981年 | 23篇 |
1979年 | 41篇 |
1978年 | 28篇 |
1977年 | 34篇 |
1975年 | 33篇 |
1974年 | 29篇 |
1973年 | 25篇 |
1972年 | 28篇 |
1971年 | 21篇 |
排序方式: 共有5322条查询结果,搜索用时 0 毫秒
1.
Takako Miyamae Masaaki Mori Yasuji Inamo Youichi Kohno Shuji Takei Motoharu Maeda Takuji Murata Shuji Nakata Hiroshi Kawai Yukiko Hirano Yukiji Date Katsuhiko Kitamura Shumpei Yokota 《Ryūmachi》2003,43(3):538-543
OBJECTIVES: To reveal the frequency and the clinical characteristics of dystrophic calcification that occurs in children with juvenile dermatomyositis, multi-center analysis was constructed. METHOD: Fifty children with JDM were enrolled, and 14 of them (28.0%) were complicated with calcinosis. Clinical symptoms and laboratory tests at onset, initial therapy and disease course were compared in children with and without calcinosis. RESULTS: The mean age of the onset of calcinosis was 4.78 +/- 3.33 years, and it was younger than those of children without calcinosis (8.66 +/- 3.85 years) (P = 0.0017). No differences of clinical manifestation except Gower's sign were observed. The frequency of positive anti-nuclear antibody was 7.1% in children with calcinosis and 52.9% without calcinosis (P = 0.0112). The initial therapy of methylprednisolon pulses gave no effects on prognosis of calcium deposition. The calcinosis appeared in 1.56 +/- 1.91 year after the onset of the disease. The various types of calcium deposition including large tumorous clumps, subcutaneous plaques or nodules, sheet-type calcification were deserved. They appeared over knee joints (64.3%), elbow joint (64.3%), and hip processes (50.0%). Calcinosis affecting the subcutaneous tissues frequently resulted in painful superficial ulceration of the overlying skin (42.9%), local infection (50.0%), and limitation of joint movement (14.3%). Although aluminum phosphate was effective in 2 children among 7, no other effective treatment was recommended. In 5 cases, surgical removal of tumorous clumps was operated. Thus, juvenile dermatomyositis is frequently complicated with calcinosis. This type of calcinosis was found to be unlikely to resolve completely, and resulted in severe disability in children. 相似文献
2.
3.
Hideki Ioi Shunsuke Nakata Akihiko Nakasima Amy L Counts 《American journal of orthodontics and dentofacial orthopedics》2005,128(2):206-211
INTRODUCTION: Soft tissue analysis is a basic tool in planning orthodontic treatment. However, the components of a well-balanced Japanese facial profile have not yet been established. The purpose of this study was to assess the most-favored or most well-balanced profile from a series of facial silhouettes with varying anteroposterior lip positions by a group of Japanese orthodontists and a group of young adult Japanese dental students. METHODS: Average female and male profiles were constructed from the profiles of 30 Japanese men and women with normal occlusions. The lips in each average profile were protruded or retruded in 1-mm increments, and the 13 images were arranged with the average profile in the center. Forty two orthodontists and 42 dental students were asked to select the 3 most-favored, well-balanced profiles for each sex and rank them in order of preference. RESULTS: Both the orthodontists and the students preferred a profile with slightly retruded lips. The dental students favored a more retruded lip position for women. The least-favored profile was the most protrusive. CONCLUSIONS: These findings suggest that Japanese orthodontists and young adults prefer a retruded profile, even though Japanese profiles have historically been characterized by more convex facial features. 相似文献
4.
Ocular allergic reactions and inflammatory cascades in the eye involve various arachidonic acid metabolites. One such metabolite, leukotriene B4 (LTB4) was detected in bovine lenses after incubation in Tyrode's solution and analyzed by reverse phase and normal phase high-performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC-MS). LTB4, a product of the lipoxygenase pathway has a chemotactic potency, and may play an important role in the inflammatory cascade. Our results demonstrate the capacity of the bovine lens to synthesize LTB4. It is possible that LTB4 synthesized in lenses under some conditions plays an important role in ocular inflammatory and allergic reactions. 相似文献
5.
Recombinant erythropoietin improves exercise capacity in anemic hemodialysis patients 总被引:5,自引:0,他引:5
H T Robertson N R Haley M Guthrie D Cardenas J W Eschbach J W Adamson 《American journal of kidney diseases》1990,15(4):325-332
The objective of this study was to quantitate the improvement in exercise capacity produced in anemic chronic hemodialysis (HD) patients after correction of their anemia with recombinant human erythropoietin (rHuEPO). The maximal exercise capacity and quadriceps strength of 19 anemic HD patients was tested before and after correction of the anemia with rHuEPO. A progressive work exercise protocol (PWET) on a cycle ergometer was used to compare measurements of maximal oxygen uptake (VO2max), maximal heart rate, and subjective assessment of fatigue during the test. Measurements of quadriceps strength were performed before the cycle ergometer studies. At baseline, all patients had reduced VO2max (15.3 +/- 5.4 mL/kg/min) and maximal exercise heart rates (138.5 +/- 23.9 beats/min). rHuEPO increased the mean hematocrit from 21.2% to 35%, and this was associated with a 17% increase (P less than 0.0005) in the VO2max. At any specified work load, rHuEPO treatment decreased heart rate, minute ventilation, and the subjective perception of fatigue. Both isometric and isokinetic measurements of quadriceps strength were improved following administration of rHuEPO. The maximal exercise heart rate was decreased in comparison to the baseline measurements (P less than 0.04), suggesting that in contrast to normal subjects, HD patients stop exercise before oxygen transport limitations are reached. In this unselected group of chronic HD patients, rHuEPO produced clinically significant improvements in both aerobic exercise capacity and isometric and isokinetic quadriceps strength. The improvement in aerobic capacity was substantially less than would have been expected from the correction of a comparable degree of anemia in non-HD patients. None of the 19 treated patients attained the exercise performance level predicted for a sedentary normal subject. 相似文献
6.
Minoru Sasano Mihoko Tanaka Katsuhiko Nakata Shiro Mita 《Immunopharmacology and immunotoxicology》1991,13(1):121-133
(4R)-Hexahydro-7, 7-dimethyl-6-oxo-1, 2, 5-dithiazocine-4-carboxylic acid (SA3443) is a newly synthesized cyclic disulfide compound which offers potential hepatoprotective properties.
The effect of SA3443 on the induction of natural killer (NK) and cytotoxic T lymphocyte (CTL) activities was investigated. NK activity in BALB/c mice splenic cells was investigated using YAC-1 cells as target cells. SA3443, at a dose range of 30-300 mg/kg/day, augmented NK activity significantly when administered orally once daily for 4 days before the assay. Alloantigen-specific CTL activity in splenic cells from BALB/c mice was detected 9 days after sensitization with C57BL/6 mice splenic cells. SA3443, at a dose of 100 mg/kg/day, augmented CTL activity significantly when administered orally, once daily for 4 days beginning after the sensitization and for 2 days before the assay, while a high dose of SA3443, at 300mg/kg, suppressed CTL activity.
From these results, it is thought that SA3443 may assist in the elimination of hepatitis viruses from the liver in patients with chronic active hepatitis, by the activation of NK and/or CTL activities. 相似文献
The effect of SA3443 on the induction of natural killer (NK) and cytotoxic T lymphocyte (CTL) activities was investigated. NK activity in BALB/c mice splenic cells was investigated using YAC-1 cells as target cells. SA3443, at a dose range of 30-300 mg/kg/day, augmented NK activity significantly when administered orally once daily for 4 days before the assay. Alloantigen-specific CTL activity in splenic cells from BALB/c mice was detected 9 days after sensitization with C57BL/6 mice splenic cells. SA3443, at a dose of 100 mg/kg/day, augmented CTL activity significantly when administered orally, once daily for 4 days beginning after the sensitization and for 2 days before the assay, while a high dose of SA3443, at 300mg/kg, suppressed CTL activity.
From these results, it is thought that SA3443 may assist in the elimination of hepatitis viruses from the liver in patients with chronic active hepatitis, by the activation of NK and/or CTL activities. 相似文献
7.
A comparison of the responses to recombinant human erythropoietin in normal and uremic subjects. 总被引:3,自引:0,他引:3
The erythropoietic response to graded doses of recombinant human erythropoietin (epoetin alfa) was assessed in 24 hemodialysis patients by quantitative ferrokinetic studies, and measurement of the reticulocyte count and plasma levels of transferrin receptor protein. These responses were compared to those of 22 normal subjects. Epoetin alfa was given intravenously at 15, 50 or 150 U/kg every other day for four injections. Three patients with chronic renal failure were restudied after renal function was restored following renal transplantation. The results of these three different measurements of erythroid function showed that the acute response to recombinant human erythropoietin was similar in normal subjects and patients with renal failure. We conclude that chronic uremia does not alter the responsiveness to erythropoietin in vivo. 相似文献
8.
9.
To clarify the role of serotonin in cerebral ischemia, we examined the effects of selective serotonin reuptake inhibitors, citalopram and clomipramine, on ischemic neuronal damage in the gerbil. Pretreatment with citalopram (40 mg/kg i.p.) and clomipramine (20 mg/kg i.p.) protected against neuronal destruction of hippocampal CA1 pyramidal cells following 5 min of forebrain ischemia. Furthermore, microdialysis assays showed that a striking increase in extracellular excitatory amino acid levels during ischemia was significantly inhibited by pretreatment with citalopram and clomipramine. However, citalopram (40 mg/kg i.p.) did not alter the extracellular amino acid concentrations in normal gerbils. Thus, serotonin reuptake inhibitors have a protective effect against ischemic neuronal damage. Furthermore, the present result suggests that the protective effect is mediated through prevention of the accumulation of extracellular excitatory amino acids during and after ischemia. 相似文献
10.