全文获取类型
收费全文 | 23096篇 |
免费 | 1192篇 |
国内免费 | 190篇 |
专业分类
耳鼻咽喉 | 250篇 |
儿科学 | 500篇 |
妇产科学 | 218篇 |
基础医学 | 2555篇 |
口腔科学 | 463篇 |
临床医学 | 1669篇 |
内科学 | 6334篇 |
皮肤病学 | 463篇 |
神经病学 | 1747篇 |
特种医学 | 879篇 |
外国民族医学 | 1篇 |
外科学 | 4320篇 |
综合类 | 139篇 |
一般理论 | 2篇 |
预防医学 | 581篇 |
眼科学 | 427篇 |
药学 | 1347篇 |
2篇 | |
中国医学 | 78篇 |
肿瘤学 | 2503篇 |
出版年
2024年 | 35篇 |
2023年 | 210篇 |
2022年 | 434篇 |
2021年 | 740篇 |
2020年 | 418篇 |
2019年 | 503篇 |
2018年 | 667篇 |
2017年 | 466篇 |
2016年 | 631篇 |
2015年 | 596篇 |
2014年 | 838篇 |
2013年 | 949篇 |
2012年 | 1473篇 |
2011年 | 1731篇 |
2010年 | 963篇 |
2009年 | 862篇 |
2008年 | 1429篇 |
2007年 | 1459篇 |
2006年 | 1417篇 |
2005年 | 1477篇 |
2004年 | 1502篇 |
2003年 | 1340篇 |
2002年 | 1221篇 |
2001年 | 247篇 |
2000年 | 213篇 |
1999年 | 236篇 |
1998年 | 258篇 |
1997年 | 243篇 |
1996年 | 170篇 |
1995年 | 143篇 |
1994年 | 157篇 |
1993年 | 116篇 |
1992年 | 141篇 |
1991年 | 122篇 |
1990年 | 97篇 |
1989年 | 84篇 |
1988年 | 95篇 |
1987年 | 93篇 |
1986年 | 78篇 |
1985年 | 63篇 |
1984年 | 63篇 |
1983年 | 36篇 |
1982年 | 44篇 |
1981年 | 30篇 |
1979年 | 33篇 |
1978年 | 35篇 |
1977年 | 41篇 |
1976年 | 33篇 |
1973年 | 28篇 |
1970年 | 25篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
Yoshihiro Miyake Masashi Arakawa Keiko Tanaka Satoshi Sasaki Yukihiro Ohya 《Pediatric allergy and immunology》2007,18(5):433-440
Uncertainties remain as to whether breastfeeding is protective against childhood allergic disorders. Positive relationships of breastfeeding with asthma and atopic eczema were observed in two previous Japanese studies. This cross-sectional study investigated the association between the feeding pattern after birth and the prevalence of allergic disorders during the past 12 months in Japanese schoolchildren. Study subjects were 24,077 children aged 6-15 yr in Okinawa. The outcomes were based on diagnostic criteria from the International Study of Asthma and Allergies in Childhood. Allowance was made for age, sex, number of siblings, smoking in the household, paternal and maternal history of asthma, atopic eczema, and allergic rhinitis, and paternal and maternal educational level. Breastfeeding, regardless of exclusivity, for 13 months or longer and exclusive breastfeeding for 4-11 months were independently associated with a higher prevalence of atopic eczema, particularly among children without a parental allergic history. A clear positive dose-response relationship was observed between prolonged duration of breastfeeding, regardless of exclusivity, but not exclusive breastfeeding, and the prevalence of atopic eczema. We found a significant positive trend for atopic eczema across the three categories (formula milk, partial and exclusive breastfeeding) in the first 4 months of life although the odds ratio for exclusive breastfeeding was not statistically significant. No material association was found between the feeding pattern after birth and the prevalence of wheeze or allergic rhinoconjunctivitis. Prolonged breastfeeding may be associated with a higher prevalence of atopic eczema in Japanese children. 相似文献
22.
Satoshi Yamamoto MD ; Yosinobu Sato MD ; Toru Abo MD ; Katsuyosi Hatakeyama MD 《Wound repair and regeneration》2002,10(4):241-244
Recently, we found CD3-CD4(bright) cells with comparative specificity for normal rat liver. In the current study, we investigated the type and form of both CD3-CD4(bright) cells and CD3-CD4(dull) cells in the rat liver. The surface phenotype of hepatic mononuclear cells in Lewis rats was identified by using monoclonal antibodies including anti-CD4, anti-CD3, and antimacrophage in conjunction with two- or three-color immunofluorescence analysis. CD3-CD4(bright) cells and CD3-CD4(dull) cells were examined morphologically using May-Giemsa staining and scanning electron microscopy. The distribution of CD3-CD4(bright) cells and CD3-CD4(dull) cells 48 hours after intravenous administration of liposome-encapsulated dichloromethylene diphosphate was also investigated. In comparison to CD3-CD4(dull) cells, CD3-CD4(bright) cells were slightly larger macrophages with abundant cytoplasmic granules, being present with comparative specificity for normal rat liver and showing negligible effects by intravenous liposome-encapsulated dichloromethylene diphosphate administration. These data suggest that in normal young rat liver these CD3-CD4(dull) and CD3-CD4(bright) cells may be dendritic cells and Kupffer cells that shift from the liver to the spleen or vice versa. These cells may also be able to locally proliferate in liver or spleen due to changes in the developing liver. 相似文献
23.
24.
We report on a 66-year-old woman in whom GPi pallidotomy produced progressive and eventually complete relief of hemichorea/ballism (HCB) after a subthalamic hemorrhage. Although choreoballistic movements were unchanged during and immediately after the surgery, the symptoms were gradually improved and consequently abolished by 5 days postoperatively. HCB has never recurred up to the present (9 months follow-up period). This note is the first report describing detailed postsurgical process in HCB relief after pallidotomy. 相似文献
25.
Activity labeling was applied to the olfactory systems of the terrestrial slug Limax valentianus using 2-(N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino)-2-deoxyglucose (2-NBDG), a fluorescent derivative of glucose. 2-NBDG was incorporated into cultured Limax olfactory interneurons, and this was partially blocked by the presence of a high concentration of glucose in the medium, indicating that a part of the uptake of 2-NBDG is mediated by glucose transporters. Next, in order to map odor-related neuronal activity in the primary olfactory center, tentacular ganglion, we injected 2-NBDG into the body cavities of slugs and exposed them to odors or clean air (control). In the odor-stimulated animals, the cell mass region was strongly stained. The digit-like extensions and the neuropil region were also stained in some animals. The control animals showed no staining. The neurons in the cell mass are thought to be involved in generating oscillating activities in the tentacular ganglion, and their activation may imply modulation of oscillatory activity during odor processing. Our results show that 2-NBDG is useful for mapping neuronal activity in vivo. 相似文献
26.
Hideaki Ban Hiroyuki Kato Tsutomu Araki Hideaki Fujikura Yoshinari Hasegawa Kyuya Kogure 《Brain research》1994,646(2)
We investigated the effects of age and naftidrofuryl oxalate (Naftidrofuryl), a 5-HT2 antagonist, on neurotransmission and transduction systems in the gerbil hippocampus using quantitative autoradiography. [3H]Quinuclidinyl benzilate (QNB), [3H]cyclohexyl-adenosine (CHA), [3H]MK-801, and [3H]muscimol were used to label muscarinic acetylcholine, adenosine A1, N-methyl-d-aspartate (NMDA), and γ-aminobutyric acid-A (GABAA) receptors, respectively. [3H]PN200-110 labeled L-type Ca2+ channels. [3H]Forskolin, [3H]cyclic adenosine monophosphate (cAMP), [3H]phorbol 12,13-dibutyrate (PDBu), and [3H]inositol 1,4,5-triphosphate (IP3) were used to label adenylate cyclase, cAMP-dependent protein kinase, protein kinase C (PKC), and IP3 receptors, respectively. Approximately 20% reductions in [3H]QNB, [3H]forskolin, and [3H]PDBu binding were observed in the hippocampus of 9-month-old gerbils in comparison with 5-week-old gerbils. Treatment with Naftidrofuryl (10 mg/kg, i.p., once a day for 7 days) ameliorated these reductions. No changes were found in [3H]CHA, [3H]MK-801, [3H]muscimol, [3H]PN200-110, [3H]cAMP, and [3H]IP3 binding. The results suggest that Naftidrofuryl may have beneficial effects on the age-related alterations in signal transmission and transduction systems in the brain. Because the acetylcholine system, adenylate cyclase, and PKC are considered to be involved in learning and memory processes, the result may have clinical implications. 相似文献
27.
28.
29.
Arrhythmogenic right ventricular dysplasia/cardiomyopathy assessed with 64-slice computed tomography
Nishiyama Kei; Tadamura Eiji; Kanao Eitaro; Shizuta Satoshi; Furukawa Yutaka; Nakagawa Yoshihisa; Kimura Takeshi; Kita Toru 《European heart journal》2006,27(22):2666
A 69-year-old man was admitted to hospital because of sustainedventricular tachycardia with right bundle branch block morphology.After abolition of ventricular tachycardia, an electrocardiogramshowed atrial fibrillation, complete right bundle 相似文献
30.
Kazuhiko Suzuki Hiroshi Tanaka Satoshi Kaneko Motoi Nishi Shin Teramoto Susumu Itoh Shosaku Abe 《The Journal of asthma》2003,40(3):243-250
The relation between smoking and risk of asthma has been well-examined; however little attention has been paid to the correlation between smoking and asthma symptoms. The aims of this study were to examine respiratory symptoms in asthmatics with a highly prevalent use of inhaled corticosteroid (ICS) and to assess the effects of smoking and its cessation. A cross-sectional study of pulmonologist-based 3197 asthmatics (men 45.2%, ages 20-97) was performed using a questionnaire about smoking habits, the incidence and frequency of symptoms (sputum, cough and wheezing, night symptoms, and shortness of breath), physical activity interference, and medication. Although 81.4% of the patients used ICS according to the international guideline, 14.9% had activity interference, and daily symptoms remained in 43.3%. At the time of the questionnaire, 21.6% were current and 25.1% were ex-smokers. In multiple logistic regression analysis, the factors of significance (p < 0.0001) were (1) smoking; for all four symptoms, (2) age and duration of asthma; for shortness of breath. Current smokers were at a risk of sputum (age-adjusted odds ratio 2.32 [95% confidence interval 1.73-3.11]; 2.09 [1.57-2.79]), of cough and wheezing (2.38 [1.81-3.14]; 1.78 [1.35-2.36]), of night symptoms (1.95 [1.41-2.60]; 1.47 [1.09-1.98]), and of shortness of breath (1.70 [1.26-2.28]; 1.30 [0.97-1.75]) in men and women, respectively. These ratios in ex-smokers decreased to the level similar to nonsmokers. Although 81.4% of asthmatic patients used ICS, 43.3% complained of daily respiratory symptoms, especially sputum. It is suggested that the effects of ICS on asthma symptoms may be interfered with by smoking and therefore more emphasis should be placed on cessation of smoking. 相似文献