全文获取类型
收费全文 | 47810篇 |
免费 | 2383篇 |
国内免费 | 267篇 |
专业分类
耳鼻咽喉 | 519篇 |
儿科学 | 1076篇 |
妇产科学 | 549篇 |
基础医学 | 5799篇 |
口腔科学 | 1149篇 |
临床医学 | 3217篇 |
内科学 | 12801篇 |
皮肤病学 | 914篇 |
神经病学 | 3554篇 |
特种医学 | 1660篇 |
外科学 | 8901篇 |
综合类 | 174篇 |
一般理论 | 3篇 |
预防医学 | 1317篇 |
眼科学 | 715篇 |
药学 | 3090篇 |
中国医学 | 144篇 |
肿瘤学 | 4878篇 |
出版年
2023年 | 286篇 |
2022年 | 482篇 |
2021年 | 1098篇 |
2020年 | 591篇 |
2019年 | 773篇 |
2018年 | 994篇 |
2017年 | 765篇 |
2016年 | 951篇 |
2015年 | 912篇 |
2014年 | 1262篇 |
2013年 | 1522篇 |
2012年 | 2405篇 |
2011年 | 2683篇 |
2010年 | 1545篇 |
2009年 | 1383篇 |
2008年 | 2397篇 |
2007年 | 2550篇 |
2006年 | 2495篇 |
2005年 | 2634篇 |
2004年 | 2598篇 |
2003年 | 2457篇 |
2002年 | 2292篇 |
2001年 | 1324篇 |
2000年 | 1395篇 |
1999年 | 1245篇 |
1998年 | 612篇 |
1997年 | 488篇 |
1996年 | 430篇 |
1995年 | 389篇 |
1994年 | 359篇 |
1993年 | 339篇 |
1992年 | 838篇 |
1991年 | 766篇 |
1990年 | 716篇 |
1989年 | 763篇 |
1988年 | 675篇 |
1987年 | 632篇 |
1986年 | 565篇 |
1985年 | 535篇 |
1984年 | 362篇 |
1983年 | 297篇 |
1982年 | 151篇 |
1979年 | 270篇 |
1978年 | 194篇 |
1977年 | 166篇 |
1974年 | 160篇 |
1973年 | 171篇 |
1972年 | 169篇 |
1971年 | 157篇 |
1970年 | 156篇 |
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
71.
Masaru Kato Rie Kobayashi Ikuo Watanabe 《Documenta ophthalmologica. Advances in ophthalmology》1993,84(1):71-81
An unusual form of scotopic electroretinogram with a bright white stimulus, which consisted of a rectangular a-wave of normal amplitude and a b-wave of supernormal amplitude, was recorded in three patients with cone dysfunction. In addition to poor visual acuity, abnormal color vision and reduced amplitude of the photopic electroretinogram, these patients showed a 2-log unit elevation of the dark-adaptation threshold. Funduscopic examination and fluorescein angiography revealed fine granular pigment disturbances at the mascula. The relationship between the response of the dark-adapted electroretinogram versus stimulus intensity was unique to these patients. The b-wave thresholds were elevated by 1 log unit. The b-waves were reduced in amplitude and markedly delayed in implicit time to dim stimuli, but supernormal in amplitude and normal in implicit time to bright stimuli.Abbreviations GMP
guanosine monophosphate 相似文献
72.
Cytokines in bronchoalveolar lavage fluid in patients with high altitude pulmonary oedema at moderate altitude in Japan. 总被引:5,自引:0,他引:5
K. Kubo M. Hanaoka S. Yamaguchi T. Hayano M. Hayasaka T. Koizumi K. Fujimoto T. Kobayashi T. Honda 《Thorax》1996,51(7):739-742
BACKGROUND: The precise mechanism of high altitude pulmonary oedema (HAPE) remains unclear. The purpose of this study was to evaluate the role of cytokines and P-selectin in the development of HAPE which occurred at moderate altitude in Japan. METHODS: The following cellular and biochemical markers and chemotactic cytokines were measured in the bronchoalveolar (BAL) fluid from four patients with HAPE at 2857-3180 m in the Japanese Alps: total proteins, albumin, lactate dehydrogenase (LDH), and interleukin (IL)-1 alpha, IL-1 beta, IL-1 receptor antagonist (ra), IL-6, IL-8, IL-10, tumour necrosis factor (TNF)-alpha, and the soluble form of P-selectin. RESULTS: At admission there were significant increases in the levels of total cells, especially macrophages and neutrophils, total protein, albumin and LDH when compared with 13 healthy individuals. Furthermore, the levels of IL-1 beta, IL-6, IL-8, and TNF-alpha were also considerably increased but returned quickly to the normal ranges or were not detected after recovery. The levels of IL-1 alpha, IL-10, and P-selectin did not change. CONCLUSIONS: These results suggest that an inflammatory process almost identical with acute respiratory distress syndrome (ARDS) may occur in HAPE, but that these changes are transient and are not associated with any increase in P-selectin levels in the BAL fluid. 相似文献
73.
Hideya Ohnishi Kazuyoshi Nishihara Keiyoshi Tamae Shoshu Mitsuyama Ryuji Abe Satoshi Toyoshima Eiji Abe 《Surgery today》1996,26(11):929-932
Granular cell tumors (GCT) are rare neoplasms, and only 173 cases of benign GCT of the breast have been documented. We report herein the cases of two patients with this tumor and discuss the methods of diagnosis and treatment. The first patient was a 60-year-old woman who presented with a firm ill-defined mass in her left breast. Mammography showed a dense shadow with spicula and skin thickness, and ultrasonography revealed a hypoechoic mass with an irregular border. Radical mastectomy was performed under the wrong preoperative diagnosis of breast cancer. The second patient was a 31-year-old woman who presented with an elastic-hard mass in her left breast. Mammography showed a well-demarcated dense mass, and ultrasonography revealed a well-defined hypoechoic mass with a large depth-width ratio. Fine-needle aspiration cytology (FNAC) showed a large number of histiocytic cells with abundant granular cytoplasm. An excisional biopsy was performed, and histological examination confirmed a diagnosis of GCT. GCT is benign, but often misdiagnosed as breast cancer both clinically and radiologically. Therefore, histological examination is essential for making a correct diagnosis, while FNAC is also useful. Local resection is still the treatment of choice, and surgeons should do their utmost to avoid performing needless radical mastectomy. 相似文献
74.
75.
76.
M Teramachi F Tanaka H Esaki R Inoue M Ito K Kobayashi 《[Zasshi] [Journal]. Nihon Kyōbu Geka Gakkai》1989,37(11):2393-2397
A 14-year-old junior high school boy was admitted to our institute. Previously he had been diagnosed as having peripheral pulmonary stenosis (Gay's classification, type IV) at the age of 2 years and 10 months. On this occasion, however, a diagnosis of supravalvular aortic stenosis was made, with a pressure gradient of about 120 mmHg, and all examinations showed spontaneous remission of peripheral pulmonary stenosis. He underwent a successful standard aortoplasty. This is the first reported case of spontaneous remission of peripheral pulmonary stenosis. 相似文献
77.
The absorption and excretion and clinical effectiveness of cefixime (CFIX) granules, a new oral cephalosporin, were studied with pediatric patients with tonsillitis and urinary tract infection (UTI). Peak serum concentrations in 3 children given orally a single dose of 3 mg/kg on fasting were 0.545 micrograms/ml at 2 hours in 1 patient, and 1.56 and 1.26 micrograms/ml at 4 hours in the other 2. The half-lives in the 3 patients were 3.21-3.42 hours, with an average of 3.29 hours. The urinary concentration during the first 6 hours was 36.5 micrograms/ml in 1 patient showing the low serum level, and the first 6-hour urinary recovery rate was 7.3%. In the other 2 patients, urinary concentrations and recovery rates up to 6 hours were 87 and 62 micrograms/ml, and 17.0 and 15.1%, respectively. The second 6-hour urinary concentrations and recovery rates were 35.5 and 20.8 micrograms/ml, and 12.7 and 8.8%, respectively. The urinary recovery rates up to 12 hours were 29.7 and 23.9%, respectively. CFIX was given orally to 19 children with 20 diseases in daily doses of 6.4-12.9 mg/kg in 2 or 3 divided portions for 3 to 12 days. Clinical evaluations were made on 18 diseases. Clinical effects of CFIX were excellent in 4, good in 7 and poor in 1 of the 12 patients with tonsillitis, and excellent in 5 and good in 1 of the 6 patients with UTI. The overall clinical effectiveness rate was 94.4%. No side effects were observed in any of the 19 patients. Hematological tests, showed slight elevation of blood platelet counts in 2 patients.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
78.
Dotlike Hemosiderin Spots Are Associated With Past Hemorrhagic Strokes in Patients With Lacunar Infarcts 总被引:1,自引:0,他引:1
Toshio Imaizumi MD PhD Toshimi Honma MD PhD Yoshifumi Horita MD Satoshi Iihoshi MD PhD Tatsufumi Nomura MD Kazuhisa Yoshifuji MD Jun Niwa MD PhD 《Journal of neuroimaging》2005,15(2):157-163
BACKGROUND AND PURPOSE: Dotlike hemosiderin spots ongradient-echo T2(*)-weighted magnetic resonance imaging of the brain have been histologically diagnosed as old microbleeds associated with small vessel disease (SVD). The authors hypothesize that the presence of many dotHSs may be correlated with the fragility of small vessels and the recurrence of SVD, including lacunar infarction and deep intracerebral hemorrhage (ICH). METHODS: To investigate how dotHSs are related to past history of SVD, the number of subcortical or deep dotHSs was investigated in 146 patients with lacunar infarctions (95 men, 51 women, age 38 to 90 [66.6+/-9.4] years). They were divided into 2 subgroups according to history of deep ICHs or lacunar infarctions. The odds ratio (OR) for past history was estimated from logistic regression analyses with the number of subcortical or deep dotHSs as well as other factors. RESULTS: Of 146 patients with lacunar infarctions, 11 had past symptomatic ICHs and 19 had past symptomatic lacunar infarctions. An elevated rate of history of ICH was found for lacunar infarction patients with many deep dotHSs (>or=3; OR, 9.1; 95% confidence interval, 1.6-51, P=.015). However, history of lacunar infarction was not significantly associated with the number of subcortical or deep dotHSs. CONCLUSIONS: Our findings suggest that many deep dotHSs on T2(*)-weighted magnetic resonance imaging may be correlated with deep ICH-lacunar infarction type of SVD recurrence but not lacunar infarction-lacunar infarction type. 相似文献
79.
80.
H Nakanishi T Monden H Morimoto T Kobayashi T Shimano T Mori 《British journal of cancer》1991,64(2):239-242
Perforin (PFP) is a cytotoxic protein released from killer cells. PFP immunoreactivity in human peripheral blood lymphocytes (PBL) and tumour infiltrating lymphocytes (TIL) was investigated immunocytochemically with the aid of an anti-PFP monoclonal antibody. PFP was detected in the cytoplasm of 10% of PBL. We performed a double staining of PFP+ cells with Leu11b/CD16, Leu2a/CD8, or Leu3a/CD4 and showed that PFP was produced by 9% of CD8+ cells and 18% of CD16+ cells but not by CD4+ cells. In 28 colorectal cancer tissues, PFP immunoreactivity was observed in the lymphocytes infiltrating to the tumour stroma. The PFP+ cells were most numerous in Dukes A and decreased in number according to the progression of tumours. The PFP+ cells in TIL exhibited the same phenotypes as those in PBL but the PFP+ cells were more numerous in CD8+ cells than in CD16+ cells at all stages. This study represents the first evidence that PFP is mainly secreted from CD8+ cells in tumour tissues. It is hypothesised that the decrease in the number of PFP+ cells in accordance with tumour progression may reflect the suppression of the hosts local immunity. 相似文献