全文获取类型
收费全文 | 52478篇 |
免费 | 3167篇 |
国内免费 | 135篇 |
专业分类
耳鼻咽喉 | 768篇 |
儿科学 | 2096篇 |
妇产科学 | 1334篇 |
基础医学 | 6481篇 |
口腔科学 | 2197篇 |
临床医学 | 4779篇 |
内科学 | 10805篇 |
皮肤病学 | 1551篇 |
神经病学 | 4079篇 |
特种医学 | 1873篇 |
外科学 | 8352篇 |
综合类 | 283篇 |
现状与发展 | 1篇 |
一般理论 | 20篇 |
预防医学 | 3106篇 |
眼科学 | 1254篇 |
药学 | 3605篇 |
中国医学 | 322篇 |
肿瘤学 | 2874篇 |
出版年
2024年 | 50篇 |
2023年 | 436篇 |
2022年 | 465篇 |
2021年 | 1120篇 |
2020年 | 652篇 |
2019年 | 997篇 |
2018年 | 1735篇 |
2017年 | 1234篇 |
2016年 | 1349篇 |
2015年 | 1314篇 |
2014年 | 1646篇 |
2013年 | 2364篇 |
2012年 | 3853篇 |
2011年 | 4385篇 |
2010年 | 2078篇 |
2009年 | 1329篇 |
2008年 | 3615篇 |
2007年 | 3839篇 |
2006年 | 3666篇 |
2005年 | 3662篇 |
2004年 | 3428篇 |
2003年 | 3123篇 |
2002年 | 2931篇 |
2001年 | 1185篇 |
2000年 | 1283篇 |
1999年 | 809篇 |
1998年 | 322篇 |
1997年 | 265篇 |
1996年 | 244篇 |
1995年 | 201篇 |
1994年 | 176篇 |
1993年 | 134篇 |
1992年 | 206篇 |
1991年 | 162篇 |
1990年 | 163篇 |
1989年 | 118篇 |
1988年 | 104篇 |
1987年 | 102篇 |
1986年 | 83篇 |
1985年 | 82篇 |
1984年 | 72篇 |
1983年 | 57篇 |
1982年 | 61篇 |
1981年 | 56篇 |
1980年 | 59篇 |
1979年 | 57篇 |
1977年 | 61篇 |
1976年 | 39篇 |
1974年 | 39篇 |
1973年 | 44篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Gülin Vural Mustafa Ünlü Tamer Atasever Izlem Özur Ayşegül Özdemir Nahide Gökçora 《European journal of nuclear medicine and molecular imaging》1997,24(3):312-315
Indium-111 octreotide and thallium-201 scintigraphic studies were compared in 21 patients (16 with palpable and five with non-palpable lesions) suspected of having breast malignancies on the basis of mammography. Early (15 min) and late (3 h)201Tl (111 MBq) and 4-h and 24-h111In-octreotide (111–148 MBq) static planar anterior images (matrix 256×256) were obtained on separate days. Images were evaluated both visually and quantitatively. Biopsy was performed following the imaging studies. Histopathology revealed 17 breast carcinomas (15 cases of invasive ductal carcinoma, one mucinous adenocarcinoma and one intraductal carcinoma) and four benign breast lesions (two fibroadenomas, one abscess and one case of fat necrosis). The means histopathologcial tumour size (mean largest diameter) was 3.38±1.9 cm.111In-octreotide detected 16 of the 17 breast cancers (94%) while201Tl detected 13 of them (76%). Both111In-octreotide and201Tl missed one nonpalpable carcinoma showing only an isolated cluster of microcalcifications on mammography. The smallest tumour size detected by both agents 1.5×1.5 cm. Of the four benign lesions, only the breast abscess revealed both201Tl and111In-octreotide uptake.111In-octreotide scan also showed tracer uptake in five of the six patients with histologically proven axillary metastases, while four of these six patients showed201Tl uptake. The tumour/background (T/B) ratios of late111In-octreotide and201Tl images were 1.71±0.38 and 1.46±0.30 respectively (P=0.039). In this preliminary study,111In-octreotide yielded more favourable results than201Tl in the detection of breast carcinomas. However, the diagnostic efficacy of111In-octreotide imaging needs to be investigated in larger patient series. 相似文献
62.
Orbital hydatid cyst is rare. We present a case with CT and MRI, emphasizing the superiority of the latter.
Received: 19 August 1996 Accepted: 9 September 1996 相似文献
63.
Mirna SuČIĆ Dubravka Boban Mirjana MarkoviĆ-glamoČak Mladen PetroveČki Matko MaruŠIĆ Boris Labar 《Medical oncology (Northwood, London, England)》1992,9(1):41-45
Cytochemical analysis of leukemic blasts from 46 patients with acute myeloblastic M2 leukemia (according to the FAB classification)
was performed before and after cytostatic therapy, and compared with findings obtained in 20 age- and sex-matched control
subjects. Cytochemical findings for myeloperoxidase (MPO), Sudan black B, acid phosphatase and alpha-naphthyl-acetate esterase
(ANAE) were related to the achievement of the first complete remission (CR),i.e. data were compared after the patients had been divided into CR and non-CR groups. The analysis clearly showed that a high
proportion of myeloperoxidase- and, to a lesser extent, Sudan black B-positive blasts before treatment may have constituted
a significantly unfavourable prognostic factor. 相似文献
64.
A finite element analysis was carried out to study the roles of posts in reducing dentin stress in pulpless teeth. Two-dimensional plane strain models of the midlabiolingual section of a human maxillary central incisor were first analyzed. The results showed that the gold alloy post reduced maximal dentin stress by as much as 30%. However, the integrity of the dentin was compromised and the effects of the post were likely to be exaggerated in such models. In an effort to correct for these problems, plane stress models with side plates and axisymmetric models were analyzed. Posts were found to reduce maximal dentin stress by only 3% to 8% when the teeth were subjected to masticatory and traumatic loadings in these latter models. Although posts reduced maximal dentin stress by as much as 20% when the teeth were loaded vertically, teeth such as incisors and canines normally are not subjected to vertical loadings. Thus the reinforcement effects of posts seem to be doubtful in these teeth. 相似文献
65.
T M Ko C Y Hsieh H N Ho F J Hsieh T Y Lee 《American journal of obstetrics and gynecology》1991,164(3):901-906
To determine the genetic origin of the complete hydatidiform mole, 20 abnormal pregnancies were studied with restriction fragment length polymorphism with five genomic probes: EJ 6.6, beta-globin gene, 3'alpha-hypervariable region, J-Bir, and St14. In the 12 cases of molar pregnancy, pure paternal origin was proved in 11 cases, but both maternal and paternal inheritance were shown in only one case. In the cases with pure paternal origin, all of the restriction fragment length polymorphisms were homozygous, although those of the fathers were heterozygous at 15 loci. In the four cases that mimicked hydatidiform mole but were diagnosed as hydropic change of villi, both paternal and maternal inheritance were noted. In the four pregnancies with blighted ovum, both paternal and maternal inheritance were shown in three cases; and in one case with a balanced translocation between chromosomes 13 and 14, only paternal inheritance was noted. This study showed that most of the complete hydatidiform moles were caused by fertilization of an empty egg by a duplicated haploid sperm, but rare exceptions may exist. 相似文献
66.
Effects of granulocyte colony-stimulating factor on bacterial translocation due to burn wound sepsis
Orhan Yalçin Gürsel Soybir Ferda Köksoy Hakki Köse Recep Öztürk Baki Çokne§eli 《Surgery today》1997,27(2):154-158
The presence of certain defects in both cellular and humoral immunity after thermal injury has been established. Likewise,
the translocation of enteric bacteria to the mesenteric lymph nodes and to distant organs has also been observed following
serious thermal injury. The effects of granulocyte colony-stimulating factor (G-CSF) on bacterial translocation, the small
bowel mucosa, and cecal bacterial content were investigated in a rat model of burn wound sepsis in which albino Wistar rats
were scalded over 30% of their bodies, after which the lesions were infected by 1×108 colony-forming units (cfu)Pseudomonas aeruginosa. The control group was treated with 5% dextrose solution subcutaneously starting 2 days preburn, while the treatment group
received 100μg/kg human G-CSF subcutaneously. On the 4th day post burn all animals were killed to examine the bowel and culture
of the mesenteric lymph nodes (MLN), livers, and spleens. No significant differences were observed between the groups regarding
the cecal bacterial content and small bowel; however, a difference was seen in the ratio of translocation in the MLN liver
and spleen and quantitative MLN cultures. Based on these findings, G-CSF was thus found to be significantly effective in reducing
bacterial translocation due to burn wound sepsis. 相似文献
67.
68.
Jan Paul Ouwens Wim van der Bij Thomas W van der Mark Albert Geertsma Do A Piers Wim J de Boer Gerard H Ko?ter 《The Journal of heart and lung transplantation》2004,23(1):115-121
BACKGROUND: A decrease in forced expiratory volume in 1 second (FEV(1)) as a diagnostic criterion for bronchiolitis obliterans syndrome (BOS) after single lung transplantation may be influenced significantly by the presence of the native lung. To quantify and to discriminate between the relative contribution of graft and native lung to the FEV(1), we retrospectively investigated the diagnostic value of combined FEV(1) measurements and ventilation scintigraphy in pulmonary dysfunction after single lung transplantation in 11 recipients with pulmonary vascular disease, 3 with obstructive lung disease, and 3 with restrictive lung disease. METHODS: We assessed function of the native lung and the graft, and subsequently calculated an adjusted grading of BOS by correcting routine FEV(1) measurements using linear interpolation of bi-annual lung ventilation scans. RESULTS: The contribution of the native lung to the total FEV(1) was slight (median, 9%) in recipients with obstructive disease compared with recipients with vascular (38%) or restrictive lung diseases (27%). Adjusted BOS grading was not useful in patients with obstructive disease. In the other patient groups, the onset of adjusted BOS Grade 1 and standard BOS Grade 1 was at a median of 220 days (range, 127-1146 days) and 836 days (184-3065 days), respectively. CONCLUSION: Ventilation scintigraphy is a useful adjunct in the (early) diagnosis of BOS in recipients of single lung transplants who have vascular and restrictive lung diseases. 相似文献
69.
P Y Chang K C Lin C Y Chuang C R Wang M Y Chen W C Hsieh G R Wang D L Cheng K S Chang Y C Ko 《Asian Pacific journal of allergy and immunology / launched by the Allergy and Immunology Society of Thailand》1992,10(1):65-68
From May 1, 1985 to December 31, 1991, a total of 4,962,707 serum samples from 8 population groups in Taiwan were tested for anti-human immunodeficiency virus type 1 (anti-HIV-1). In total, 256 samples were seropositive; of these individuals, 43 developed acquired immunodeficiency syndrome (AIDS): 29 were homosexuals; 5 were hemophiliacs; 8 were heterosexuals and 1 was of unknown risk. Although the prevalence of HIV-1 infection and AIDS remains low compared with other countries, since 1988 the increase has been rapid. Before 1977 the majority were homosexuals and hemophiliacs; thereafter the risk groups diversified, with a trend away from homosexuals and hemophiliacs towards heterosexuals and intravenous drug abusers (IVDAs). A few patients have caused serious social problems for the public, health care workers and families. Active community efforts are needed to achieve future success in the control of HIV-1 infection and AIDS in Taiwan. 相似文献