全文获取类型
收费全文 | 42281篇 |
免费 | 2157篇 |
国内免费 | 245篇 |
专业分类
耳鼻咽喉 | 514篇 |
儿科学 | 804篇 |
妇产科学 | 665篇 |
基础医学 | 5230篇 |
口腔科学 | 1318篇 |
临床医学 | 3229篇 |
内科学 | 10442篇 |
皮肤病学 | 937篇 |
神经病学 | 2998篇 |
特种医学 | 1624篇 |
外科学 | 7295篇 |
综合类 | 278篇 |
一般理论 | 2篇 |
预防医学 | 1249篇 |
眼科学 | 631篇 |
药学 | 2844篇 |
中国医学 | 63篇 |
肿瘤学 | 4560篇 |
出版年
2023年 | 228篇 |
2022年 | 498篇 |
2021年 | 871篇 |
2020年 | 453篇 |
2019年 | 638篇 |
2018年 | 841篇 |
2017年 | 649篇 |
2016年 | 734篇 |
2015年 | 839篇 |
2014年 | 1069篇 |
2013年 | 1220篇 |
2012年 | 1949篇 |
2011年 | 2082篇 |
2010年 | 1165篇 |
2009年 | 1049篇 |
2008年 | 1808篇 |
2007年 | 1913篇 |
2006年 | 1978篇 |
2005年 | 2025篇 |
2004年 | 1961篇 |
2003年 | 1903篇 |
2002年 | 1897篇 |
2001年 | 1369篇 |
2000年 | 1522篇 |
1999年 | 1356篇 |
1998年 | 503篇 |
1997年 | 374篇 |
1996年 | 381篇 |
1995年 | 347篇 |
1994年 | 322篇 |
1993年 | 291篇 |
1992年 | 865篇 |
1991年 | 844篇 |
1990年 | 739篇 |
1989年 | 771篇 |
1988年 | 747篇 |
1987年 | 710篇 |
1986年 | 710篇 |
1985年 | 624篇 |
1984年 | 457篇 |
1983年 | 380篇 |
1979年 | 367篇 |
1978年 | 244篇 |
1977年 | 204篇 |
1975年 | 205篇 |
1974年 | 231篇 |
1973年 | 218篇 |
1971年 | 223篇 |
1970年 | 208篇 |
1969年 | 238篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
Radiographic studies of three cases of hypoplasia of the humeral trochlea were done. Several other anomalies were also detected, including a hypoplastic capitellum in case 2, a hyperplastic radial head in cases 2 and 3, and bulging of the loose joint capsule in case 3. Operations in cases 1 and 3, disclosed that ganglions and fibrous septa compressed the ulnar nerve. The cause of ulnar nerve palsy in patients with hypoplasia of the humeral trochlea is thought to be associated with the high incidence of ganglions in hypoplastic elbow joints. The ganglion may play a role. 相似文献
82.
83.
84.
Abstract: The effects of pyridoxalated hemoglobin polyoxyethylene conjugate (PHP) and stroma-free hemoglobin (SFH) on vascular responsiveness to various vasoactive substances were examined in isolated perfused rat kidneys. The kidneys isolated from rats were perfused with 6% PHP, 6% SFH, and 6% hydroxyethylstarch (HES) solution at a constant flow rate. Vascular responsiveness to acetylcholine (ACh), nitroglycerin (NG), norepinephrine (NE), and angiotensin-II (ANG-II) was examined by measuring the perfusion pressure (PP). Effects of inhibition of endothelium-derived relaxing factor (EDRF) by NG -monomethyl L-arginine (L-NMMA) on NE-induced and ANG-II-induced renal vascular responses were examined. ACh and NG induced a dose-dependent decrease in perfusion pressure (PP) in all groups. NE and ANG-II induced an increase in PP in all groups, but NE-induced and ANG-II-induced responses in the PHP-perfused and SFH-perfused groups were significantly larger than those in the HES-perfused group. L-NMMA did not alter vascular responsiveness to NE and ANG-II. These results indicate that PHP and SFH do not inhibit EDRF induced by ACh, but hemoglobin moiety per se does augment the vascular responsiveness to NE and ANG-II in the isolated perfused rat kidney. 相似文献
85.
Atsuo Furuhashi M.D. Yasutaka Akasaki M.D. Masayasu Sato M.D. Koho Miyoshi M.D. 《Psychiatry and clinical neurosciences》1994,48(3):645-653
Abstract: The behavioral effects of ceroid-lipofuscin accumulation, induced by intraperitoneal administration of acetyl-ethyl-tetramethyl-tetralin (AETT) in Wistar rats for 3 months, were examined in the present studies. A significant increase in neuronal ceroid-lipofuscin was demonstrated neuropathologically as well as morphometrically. Although the AETT-intoxicated rats showed neither alteration of locomotor activity nor shock sensitivity, a significant impairment of learning ability, especially an acquisition trial in passive avoidance tests, was observed. Results of the present studies indicate the possibility that a diffuse lipofuscin accumulation causes a learning impairment in rats. The results also imply the possibility of a significant role of age-related lipofuscin accumulation in the dementing processes of human especially in the elderly. 相似文献
86.
To examine whether prostacyclin has an attenuating effect on nonspecific bronchial responsiveness in asthma, we measured provocative concentration of methacholine producing a 20% fall in forced expiratory volume in 1 second (PC20-FEV1) before and after oral administration of a chemically stable prostacyclin analog (OP-41483) (200 μg 4 times a day for 4 days) in 8 patients with stable asthma. Neither baseline pulmonary function nor PC20-FEV1 significantly improved after the treatment. These results suggest that prostacyclin may have no direct effect on bronchial responsiveness in asthmatics. Further studies using more potent and long-lasting prostacyclin mimetic will be needed to confirm the conclusion. 相似文献
87.
The authors recently experienced a case of idiopathic interstitial pneumonia (IIP) that exhibited skin ulcers due to increased heparin precipitable fraction (HPF) in plasma. This case prompted us to investigate the occurrence and significance of HPF in interstitial pneumonia (IP). The subjects included patients with IIP (acute exacerbation 6 cases, chronic active stage 12 cases), IP associated with collagen vascular disease (CVD) (9 cases) and granulomatous lung diseases (7 cases). The data indicated that all of the cases with acute exacerbation of IIP exhibited increased plasma HPF values (218-951 mg/dl) compared to those of normal controls (less than 180 mg/dl). In contrast, the values ranged within normal limits in all of the cases with IP associated with CVD. In a companion study, we measured plasma HPF values in patients with lung cancer, bacterial pneumonia and diffuse panbronchiolitis. It was found that 22% of the subjects showed increased plasma HPF values. We also investigated whether there were correlations between plasma HPF and various inflammatory parameters. The data revealed that there were correlations between HPF and ESR, CRP, alpha 1-globulin, alpha 2-globulin, complement (C3) or fibrinogen. However, there was no correlation between HPF and fibronection. These results suggest that plasma HPF is valuable to evaluate the acute exacerbation of IIP, although the elevation of plasma HPF levels is not specific. 相似文献
88.
H Sato H Matsuda T Hatakeyama M Okada K Nakamura 《The Journal of cardiovascular surgery》1992,33(2):202-203
Primary pulmonary artery sarcoma is a rare tumor. We present a case report in which the presumptive diagnosis was made preoperatively with magnetic resonance imaging, Doppler color flow methods, and computer tomography. Surgical treatment was successful. 相似文献
89.
90.
Tamaki Sasaki Tetsuya Sato Yoshiyuki Jyo Nobuya Tanda Hitoshi Tamai Gengo Osawa 《Clinical and experimental nephrology》1997,1(1):32-40
Background We previously found that glomerular epithelial cells play an important role in the formation of adhesive lesions. Glomerular
sclerotic lesions develop after the inital adhesive lesions.
Methods Two series of experiments were done with spontaneously diabetic WBN/Kob rats. These rats develop segmental glomerular sclerotic
lesions with aging. The first series of experiments was intended to clarify the kinetics of glomerular cells on progressive
glomerular damage in these rats. The second series of experiments was designed to study the relationship between proliferation
(judged by % bromodeoxyuridine-positive cells) of glomerlar epithelial cells and sclerotic lesions with adhesions.
Results In the first series, rats having increased proteinuria showed segmental glomerular sclerotic lesions with adhesions. At the
same time, increased labeling indices of tuft cells and epithelial cells of Bowman's capsule were observed. In the second
series, no significant increase in the labeling indices of tuft cells with sclerotic lesions was observed, compared to tuft
cells without sclerotic lesions. In sclerotic lesions with adhesion, bromodeoxyurdine-positive cells were observed that were
not distinguishable as podocytes or epithelial cells of Bowman's capsule. The highest labelling index was noted in the epithelial
cells of Bowman's capsules with sclerosis.
Conclusion This study shows that the proliferation of glomerular epithelial cells (mainly epithelial cells of Bowman's capsule) occurs
in glomerular sclerotic lesions with adhesions. 相似文献