全文获取类型
收费全文 | 9341篇 |
免费 | 469篇 |
国内免费 | 105篇 |
专业分类
耳鼻咽喉 | 177篇 |
儿科学 | 187篇 |
妇产科学 | 96篇 |
基础医学 | 1712篇 |
口腔科学 | 134篇 |
临床医学 | 853篇 |
内科学 | 1850篇 |
皮肤病学 | 211篇 |
神经病学 | 547篇 |
特种医学 | 628篇 |
外科学 | 1123篇 |
综合类 | 30篇 |
一般理论 | 2篇 |
预防医学 | 336篇 |
眼科学 | 253篇 |
药学 | 893篇 |
1篇 | |
中国医学 | 98篇 |
肿瘤学 | 784篇 |
出版年
2023年 | 45篇 |
2022年 | 151篇 |
2021年 | 363篇 |
2020年 | 181篇 |
2019年 | 205篇 |
2018年 | 273篇 |
2017年 | 213篇 |
2016年 | 262篇 |
2015年 | 411篇 |
2014年 | 528篇 |
2013年 | 566篇 |
2012年 | 796篇 |
2011年 | 765篇 |
2010年 | 472篇 |
2009年 | 413篇 |
2008年 | 551篇 |
2007年 | 582篇 |
2006年 | 507篇 |
2005年 | 439篇 |
2004年 | 318篇 |
2003年 | 296篇 |
2002年 | 232篇 |
2001年 | 212篇 |
2000年 | 205篇 |
1999年 | 177篇 |
1998年 | 71篇 |
1997年 | 65篇 |
1996年 | 65篇 |
1995年 | 54篇 |
1994年 | 53篇 |
1993年 | 45篇 |
1992年 | 36篇 |
1991年 | 38篇 |
1990年 | 30篇 |
1989年 | 40篇 |
1988年 | 39篇 |
1987年 | 38篇 |
1986年 | 28篇 |
1985年 | 26篇 |
1984年 | 14篇 |
1983年 | 13篇 |
1982年 | 11篇 |
1981年 | 9篇 |
1980年 | 10篇 |
1979年 | 8篇 |
1978年 | 9篇 |
1977年 | 11篇 |
1976年 | 8篇 |
1975年 | 7篇 |
1968年 | 4篇 |
排序方式: 共有9915条查询结果,搜索用时 46 毫秒
31.
Eung Y. Kim Dong-Hyun Kim Eunhye Yoo Hae-Jeong Park Xavier Golay Seung-Koo Lee Dong J. Kim Jinna Kim Dong I. Kim 《International journal of developmental neuroscience》2007,25(6):409-414
Previous studies have shown that maturation of the white matter in terms of its relative signal intensity changes on MRI is almost complete at 2-3 years of age. We hypothesized that quantitative analysis may show maturation of the white matter during childhood and adolescence. In the present study we performed multi-echo T2 relaxometry in 33 healthy subjects (girls, 15; boys, 18) aged 3-15 years. T2 relaxation times of the genu and splenium were measured. In healthy subjects, the T2 relaxation times were significantly correlated with age in both girls (r=0.611, p=.016) and boys (r=0.721, p=.001) in the splenium, but not in the genu (p>.05). To further confirm genu-to-splenium signal intensity ratio changes, a total of 389 brain MRIs were retrospectively selected from the patients who had normal results (189 girls/women, 200 boys/men; age range, 3-20 years). The genu-to-splenium signal intensity ratio was obtained from the T2-weighted images. In patients with normal MRI, the genu-to-splenium signal intensity ratio was significantly decreased with age (p<.001) by 16 years. The T2 relaxation times gradually increase in the splenium during childhood and adolescence, suggestive of maturation. 相似文献
32.
Sungil Jang Eun Jung Bak Minyoung Kim Jin Moon Kim Won-Yoon Chung Jeong-Heon Cha Yun-Jung Yoo 《Phytotherapy research : PTR》2010,24(7):964-968
To evaluate the inhibitory activity of wogonin against lipopolysaccharide (LPS)-induced bone resorption, we investigated the effect of wogonin on osteoclastogenesis induced by LPS. Wogonin inhibited LPS-induced osteoclastogenesis in co-cultures of mouse calvaria-derived osteoblasts and bone marrow-derived pre-osteoclasts. Wogonin also suppressed osteoclastogenesis in LPS-injected mouse calvaria. In osteoblasts, the upregulation of receptor activator of nuclear factor-κB (RANKL) expression and the downregulation of osteoprotegerin (OPG) expression by LPS were inhibited by wogonin. Wogonin and NS-398, a COX-2 inhibitor, suppressed LPS-stimulated PGE2 production in osteoblasts. NS-398 inhibited the effect of LPS on RANKL and OPG expression in osteoblasts. These results suggest that wogonin acts as an inhibitor of LPS-induced osteoclastogenesis through downregulation of RANKL and upregulation of OPG expression via blockage of PGE2 production. Based on these results, wogonin has potential for use as a therapeutic agent in bacteria-induced bone resorption. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
33.
34.
Intestinal schistosomiasis japonica: CT-pathologic correlation 总被引:1,自引:0,他引:1
Lee RC; Chiang JH; Chou YH; Rubesin SE; Wu HP; Jeng WC; Hsu CC; Tiu CM; Chang T 《Radiology》1994,193(2):539
35.
36.
Summary. Because of the belief that post-operative deep vein thrombosis (DVT) is rare in Asian patients, thromboprophylaxis is not
usually prescribed for surgical patients. This study reports an open multi-centre controlled study of the use of a low molecular
weight heparin, nadroparin calcium (Fraxoparine Sanofi France), as opposed to no prophylaxis in 100 patients undergoing uncemented
total hip replacement. The patients had bilateral venography performed preoperatively and 10 days after operation. Eight patients
(16%) developed DVT in the control group of 50 patients and 1 (2%) in the treatment group, also of 50 patients. Pulmonary
embolus occurred in 1 patient in the treatment group and in 3 in the control group. Intraoperative and postoperative blood
loss did not differ significantly between the two groups. Our study suggests that the incidence of DVT in Asian patients,
though somewhat less than in their Western counterparts, is still considerable. It confirms the safety and efficacy of nadroparin
calcium in preventing post-operative DVT in patients undergoing elective total hip replacement.
Accepted: 19 March 1997 相似文献
Résumé. A cause de l’idée selon laquelle la thrombose veineuse profonde post-opéraloire est rare parmi les patients asiatiques, la tromboprophylaxie pour les patients opérés est inhabituelle. Nous avons accompli une étude, comparant la prophylaxie au moyen d’héparine de bas poids moléculaire en utilisant du calcium nadroparine (Fraxiparine Sanofi France) et la non-prophylaxie sur 100 patients subissant un remplacement total de la hanche. Les patients ont subi une vénographie bilatérale avant l’opération et 10 jours après. Huit patients (16%) ont développé une thrombose veineuse dans le groupe de contr?le, contre 1 (2%) dans le groupe traité (p = 0.015, 95% CI 0.02 – 0.67). Trois embolies pulmonaires sont survenues dans le groupe de contr?le et 1 dans le groupe traité (p = 0.27 95% CI 0.04 – 2.44) aucune n’étant fatale. La perte de sang intra-opératoire et post-opératoire n’a pas varié de manière significative entre les deux groupes. Notre étude démontre que l’incidence de la thrombose veineuse profonde post-opératoire chez les patients asiatiques est notable bien qu’elle soit moindre que dans les pays occidentaux et confirme la s?reté et l’efficacité du calcium nadroparine pour la prévenir aprés un remplacement total de la hanche.
Accepted: 19 March 1997 相似文献
37.
Multiplex PCR for the detection of genes encoding aminoglycoside modifying enzymes and methicillin resistance among Staphylococcus species 总被引:4,自引:0,他引:4
Choi SM Kim SH Kim HJ Lee DG Choi JH Yoo JH Kang JH Shin WS Kang MW 《Journal of Korean medical science》2003,18(5):631-636
We developed multiplex polymerase chain reaction (PCR) to detect aac(6 ')/aph(2 "), aph(3 ')-IIIa, and ant(4 ')-Ia, the genes encoding the most clinically relevant amino-glycoside modifying enzymes (AME), and simultaneously, the methicillin resistant gene, mecA, in Staphylococcus species. Clinical isolates of 45 S. aureus and 47 coagulase negative staphylococci (CNS) from tertiary university hospitals were tested by conventional susceptibility testing, using the agar dilution method and by multiplex PCR. Of a total of 92 isolates, 61 isolates were found to be methicillin-resistant. Of these, 54 isolates (89%) were found to be harboring mecA. Seventy-five percent of the 92 isolates demonstrated resistance to at least one of the aminoglycosides tested. Moreover, resistance to aminoglycosides was closely associated with methicillin-resistance (p<0.05). The most prevalent AME gene was aac(6 ')/aph(2 ") which was found in 65% of the isolates, and ant(4 ')-Ia and aph(3 ')-IIIa were present in 41% and 9% of the isolates, respectively. The concordance between methicillin-resistance and the presence of mecA gene was 98% in S. aureus and 81% in CNS. The concordance between gentamicin resistance and the presence of aac(6 ')/aph(2 ") gene was 100% in S. aureus and 85% in CNS. The multiplex PCR method that we developed appears to be both a more rapid and reliable than conventional method. 相似文献
38.
Overexpression of S100A4 is closely related to the aggressiveness of gastric cancer 总被引:25,自引:0,他引:25
Cho YG Nam SW Kim TY Kim YS Kim CJ Park JY Lee JH Kim HS Lee JW Park CH Song YH Lee SH Yoo NJ Lee JY Park WS 《APMIS : acta pathologica, microbiologica, et immunologica Scandinavica》2003,111(5):539-545
Elevated levels of the calcium-binding protein S100A4 cause metastasis of benign rat mammary tumor cells. To investigate whether S100A4 plays an important role in the invasion and metastasis of gastric cancers, we examined the gene mutations in the coding regions and expression patterns of the S100A4 in gastric adenocarcinoma in Korea. Moderate to strong expression of S100A4 was found in 53 (68.8%) of the 77 gastric adenocarcinomas, whilst normal gastric epithelium either failed to stain or showed weak staining. Interestingly, S100A4 expression was more frequently observed in gastric cancer patients with advanced gastric cancer (p=0.039), positive lymph node metastasis (p=0.001), and peritoneal dissemination (p=0.022). No gene mutations were found in the analyzed genomic area in 77 gastric adenocarcinomas and 15 gastric cancer cell lines. We found one single nucleotide polymorphism without an amino acid change, A99G, in two cases. These data suggest that the overexpression of S100A4 may be closely related to the aggressiveness of gastric cancer in Korea. 相似文献
39.
Nae Yu Kim Jung-Soo Pyo Dong-Wook Kang Seung-Min Yoo 《Pathology, research and practice》2019,215(3):580-585
Objective
The aim of this study was to elucidate the clinicopathological significance and prognostic role of loss of claudin-1 in colorectal cancer (CRC).Methods
The correlations between claudin-1 expression and clinicopathological characteristics, including survival rates, were assessed using immunohistochemistry on 260 archival, paraffin-embedded CRC tissues. In addition, the correlations between cludin-1 and nuclear factor-kappa B (NF-κB), epithelial-mesenchymal transition markers and tumor-infiltrating lymphocytes were investigated.Results
Claudin-1 expression was markedly lost in 42.7% of the 260 CRCs analyzed. Loss of claudin-1 expression significantly correlated with larger tumor size, vascular invasion, higher pT stage, and high metastatic lymph node ratio. In addition, loss of claudin-1 expression significantly correlated with NF-κB activation (P?<?0.001), high SNAI (P?<?0.001), and low E-cadherin (P?<?0.001) expressions. Patients with high immunoscores showed significantly lower rates of claudin-1 expression loss (P?=?0.020). In detail, loss of claudin-1 expression were frequently found in CRCs low CD3- and CD8-positive lymphocytes. There were significant correlations between claudin-1 expression loss and poor overall and recurrence-free survivals (P?<?0.001 and P?<?0.001, respectively).Conclusion
Taken together, our results suggest that the loss of claudin-1 expression significantly correlates with aggressive tumor behaviors, high SNAI expression, lower immunoscore, and poor prognoses. 相似文献40.
Kim HS Lee SH Lee JW Soung YH Lee JH Park JY Cho YG Kim CJ Kim SY Lee YS Park WS Kim SH Lee JY Yoo NJ 《APMIS : acta pathologica, microbiologica, et immunologica Scandinavica》2003,111(4):490-491
Among the systems triggering apoptosis, the Fas-Fas ligand (FasL) system is recognized as a major pathway for the induction of apoptosis in cells and tissues. Ligation of Fas by either an agonistic antibody or FasL transmits a 'death signal' to the target cell, potentially triggering apoptosis. Alterations of genes along the Fas-mediated apoptosis pathway have been reported in many human cancers. However, there have been no data regarding FasL gene mutations in human cancers. We hypothesized that FasL gene mutation might be involved in the development of non-Hodgkin lymphoma (NHL). In this study, we analyzed the entire coding region of the FasL gene for the detection of somatic mutations in a series of 111 NHLs and found that one tumor had a FasL gene mutation in the cytoplasmic domain. To evaluate the functional alterations of the mutant in apoptosis, we overexpressed the mutant in 293T cells, but couldn't find any significant loss of cell death compared to the wild-type FasL. Together, these data suggest that FasL is occasionally mutated in human NHL and that FasL mutations appear to play no role in the pathogenesis of the vast majority of NHLs. 相似文献