全文获取类型
收费全文 | 2863篇 |
免费 | 147篇 |
国内免费 | 13篇 |
专业分类
耳鼻咽喉 | 9篇 |
儿科学 | 55篇 |
妇产科学 | 51篇 |
基础医学 | 469篇 |
口腔科学 | 105篇 |
临床医学 | 209篇 |
内科学 | 681篇 |
皮肤病学 | 48篇 |
神经病学 | 198篇 |
特种医学 | 68篇 |
外科学 | 506篇 |
综合类 | 16篇 |
预防医学 | 175篇 |
眼科学 | 30篇 |
药学 | 190篇 |
中国医学 | 3篇 |
肿瘤学 | 210篇 |
出版年
2023年 | 22篇 |
2022年 | 47篇 |
2021年 | 88篇 |
2020年 | 49篇 |
2019年 | 84篇 |
2018年 | 89篇 |
2017年 | 85篇 |
2016年 | 73篇 |
2015年 | 79篇 |
2014年 | 95篇 |
2013年 | 136篇 |
2012年 | 226篇 |
2011年 | 224篇 |
2010年 | 147篇 |
2009年 | 130篇 |
2008年 | 200篇 |
2007年 | 197篇 |
2006年 | 164篇 |
2005年 | 169篇 |
2004年 | 164篇 |
2003年 | 156篇 |
2002年 | 132篇 |
2001年 | 19篇 |
2000年 | 18篇 |
1999年 | 17篇 |
1998年 | 23篇 |
1997年 | 23篇 |
1996年 | 15篇 |
1995年 | 8篇 |
1994年 | 17篇 |
1993年 | 15篇 |
1992年 | 8篇 |
1991年 | 6篇 |
1990年 | 8篇 |
1989年 | 9篇 |
1988年 | 4篇 |
1987年 | 3篇 |
1986年 | 4篇 |
1985年 | 7篇 |
1984年 | 6篇 |
1983年 | 4篇 |
1982年 | 5篇 |
1976年 | 3篇 |
1971年 | 3篇 |
1966年 | 2篇 |
1962年 | 2篇 |
1939年 | 4篇 |
1937年 | 2篇 |
1933年 | 2篇 |
1932年 | 2篇 |
排序方式: 共有3023条查询结果,搜索用时 31 毫秒
71.
Guidetti A Carlo-Stella C Locatelli SL Malorni W Pierdominici M Barbati C Mortarini R Devizzi L Matteucci P Marchianò A Lanocita R Farina L Dodero A Tarella C Di Nicola M Corradini P Anichini A Gianni AM 《British journal of haematology》2012,158(1):108-119
The safety and activity of the multikinase inhibitor sorafenib were investigated in patients with relapsed or refractory lymphoproliferative disorders who received sorafenib (400 mg) twice daily until disease progression or appearance of significant clinical toxicity. The primary endpoint was overall response rate (ORR). Biomarkers of sorafenib activity were analysed at baseline and during treatment. Thirty patients (median age, 61 years; range, 18-74) received a median of 4 months of therapy. Grade 3-4 toxicities included hand/foot skin reactions (20%), infections (12%), neutropenia (20%) and thrombocytopenia (14%). Two patients achieved complete remission (CR), and two achieved partial remission (PR) for an ORR of 13%. Stable disease (SD) and progressive disease (PD) was observed in 15 (50%) and 11 patients (37%), respectively. The median overall survival (OS) for all patients was 16 months. For patients who achieved CR, PR and SD, the median time to progression and OS was 5 and 24 months, respectively. Compared with patients with PD, responsive patients had significantly higher baseline levels of extracellular signal-regulated kinase phosphorylation and autophagy and presented a significant reduction of these parameters after 1 month of therapy. Sorafenib was well tolerated and had a clinical activity that warrants development of combination regimens. 相似文献
72.
FG Reis RH Marques CM Starling R Almeida-Reis RP Vieira CT Cabido LF Silva T Lanças M Dolhnikoff MA Martins EA Leick-Maldonado CM Prado IF Tibério 《Experimental lung research》2012,38(7):344-354
ABSTRACT Background: Mechanisms linking behavioral stress and inflammation are poorly understood, mainly in distal lung tissue. Objective: We have investigated whether the forced swim stress (FS) could modulate lung tissue mechanics, iNOS, cytokines, oxidative stress activation, eosinophilic recruitment, and remodeling in guinea pigs (GP) with chronic pulmonary inflammation. Methods: The GP were exposed to ovalbumin or saline aerosols (2×/wk/4wks, OVA, and SAL). Twenty-four hours after the 4th inhalation, the GP were submitted to the FS protocol (5×/wk/2wks, SAL-S, and OVA-S). Seventy-two hours after the 7th inhalation, lung strips were cut and tissue resistance (Rt) and elastance (Et) were obtained (at baseline and after OVA and Ach challenge). Strips were submitted to histopathological evaluation. Results: The adrenals' weight, the serum cortisol, and the catecholamines were measured. There was an increase in IL-2, IL-5, IL-13, IFN-γ, iNOS, 8-iso-PGF2α, and in %Rt and %Et after Ach challenge in the SAL-S group compared to the SAL one. The OVA-S group has had an increase in %Rt and %Et after the OVA challenge, in %Et after the Ach and in IL-4, 8-iso-PGF2α, and actin compared to the OVA. Adrenal weight and cortisol serum were increased in stressed animals compared to nonstressed ones, and the catecholamines were unaltered. Conclusion & clinical relevance: Repeated stress has increased distal lung constriction, which was associated with an increase of actin, IL-4, and 8-iso-PGF2α levels. Stress has also induced an activation of iNOS, cytokines, and oxidative stress pathways. 相似文献
73.
Tarnoki AD Tarnoki DL Stazi MA Medda E Cotichini R Nisticò L Fagnani C Lucatelli P Boatta E Zini C Fanelli F Baracchini C Meneghetti G Osztovits J Jermendy G Préda I Kiss RG Metneki J Horvath T Karlinger K Racz A Lannert A Molnar AA Littvay L Garami Z Berczi V Schillaci G 《Journal of hypertension》2012,30(8):1564-1571
74.
Grinspon RP Ropelato MG Bedecarrás P Loreti N Ballerini MG Gottlieb S Campo SM Rey RA 《Clinical endocrinology》2012,76(5):698-705
Context The biphasic ontogeny of serum gonadotrophins observed in normal children also exists in girls with gonadal dysgenesis, although with higher levels. However, limited data exist in prepubertal boys with anorchia. Objective To investigate whether the existence of testicular tissue is required for gonadotrophin downregulation in boys. Secondarily, we analysed the prevalence of high gonadotrophins and its diagnostic value to assess the presence or absence of testes in childhood. Study design In a retrospective, semi‐longitudinal study, we compared serum gonadotrophin levels in 35 boys with anorchia aged 0–18 years, in 29 bilaterally cryptorchid boys with abdominal testes and in 236 normal boys. Results In anorchid boys, follicle stimulating hormone (FSH) and luteinizing hormone (LH) were abnormally high in the first months after birth, then decreased progressively. LH decreased more readily than FSH and dropped to normal values in up to 70% of anorchid patients before the usual age of pubertal onset, when both gonadotrophins increased again to very high levels. In cryptorchid boys, FSH was elevated in a significantly (P < 0·0001) lower proportion of cases. Below the age of 6 years, FSH below 2 IU/l ruled out anorchia and LH above 5 IU/l confirmed anorchia with high accuracy. Between 6 and 11 years, FSH or LH levels above 5 IU/l were highly specific for the absence of testes. Conclusions The U‐shaped pattern of serum gonadotrophins observed in normal males from birth to puberty was also found in anorchid boys, but with gonadotrophin levels considerably elevated. Serum gonadotrophin levels may normalize in anorchid boys during late childhood only to rise again at puberty. The presence of testicular tissue results in restrain of gonadotrophin secretion in most patients, even if the testes are cryptorchid. 相似文献
75.
Coronary artery embolism is an uncommon cause of myocardial infarction. We report a case of acute ST-segment elevation myocardial infarction due to a coronary embolism that originated from a calcified aortic valve. Coronary angiography demonstrated complete occlusion of the left anterior descending coronary artery. Primary percutaneous coronary intervention was successfully performed, with aspiration of the valve tissue and complete restoration of the coronary artery blood flow. This was followed by aortic valve replacement a few days later. 相似文献
76.
77.
Rodolfo Gómez Morena Scotece Javier Conde Veronica Lopez Jesus Pino Francisca Lago Juan J. Gómez‐Reino Oreste Gualillo 《Journal of orthopaedic research》2013,31(7):1046-1052
Lipocalin 2 (LCN2) has recently emerged as a novel adipokine involved in different processes including arthritis and chondrocyte inflammatory response. However, little is known about its activity on chondrocyte homeostasis and its regulation by nitric oxide (NO) Hence, we performed a set of experiments aimed to achieve a better understanding of this relationship. Cell vitality was tested in the ATDC5 cell line by the MTT colorimetric assay. Protein expression and gene expression was evaluated by Western blot and real time RT‐PCR, respectively. NO production (determined as nitrite accumulation) was assayed by the Griess reaction. First, we demonstrated that LCN2 decreased murine chondrocytes vitality. Next, LCN2 co‐stimulation with LPS enhanced NOS2 protein expression by murine chondrocytes. In addition, inhibition of LPS‐induced nitric oxide production by aminoguanidine, a selective NOS2 inhibitor, significantly reduced LPS‐mediated LCN2 expression. In contrast, treatment of murine chondrocytes with sodium nitroprussiate (SNP), a classic NO donor, scarcely induced LCN2 expression. Intriguingly, SNP addition to LPS‐challenged chondrocytes, treated with aminoguanidine, provoked a strong induction of LCN2 expression. Finally, murine ATDC5 cells, co‐cultured with LPS pre‐challenged macrophages, had higher LCN2 expression in comparison with murine chondrocytes co‐cultured with non pre‐challenged macrophages. In this work we have described for the first time that NO is able to exert a control on LCN2 expression, suggesting the existence of a feedback loop regulating its expression. © 2013 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 31:1046–1052, 2013 相似文献
78.
Manuel Mendizabal Sebastián Marciano Luciana dos Santos Schraiber Rodrigo Zapata Rodolfo Quiros Maria Lucia Zanotelli María Marta Rivas Gustavo Kusminsky Roberto Humeres Angelo Alves de Mattos Adrián Gadano Marcelo O. Silva 《Clinical transplantation》2013,27(4):E469-E477
Post‐transplant lymphoproliferative disorder (PTLD) is a major and potentially life‐threatening complication after solid‐organ transplantation. The aim of this study was to describe the disease characteristics, clinical practices, and survival related to PTLD in adult orthotopic liver transplant (OLT) recipients in South America. We conducted a survey at four different transplant groups from Argentina, Brazil, and Chile. Among 1621 OLT recipients, 27 developed PTLD (1.7%); the mean age at diagnosis was 53.7 (±14) yr with a mean time of 39.7 (±35.2) months from OLT to PTLD diagnosis. Initial therapy included reduction in immunosuppression alone in 23.1% of the patients. Either rituximab or chemotherapy was employed as initial or second‐line therapy in 76.9% of the patients. PTLD location was frequently extranodal (80.7%) and mostly involving the transplanted liver (59.3%). The overall survival at one and five yr post‐PTLD diagnosis was 53.8% and 46.2%, respectively. Significant univariate risk factors for post‐PTLD mortality included lactate dehydrogenase ≥250 U/L (HR 9.66, p = 0.02), stage III/IV PTLD (HR 5.34, p = 0.004), and HCV infection (HR 7.68, p = 0.01). In conclusion, PTLD in OLT adult recipients is predominantly extranodal, and although mortality is high, long‐term survival is possible. 相似文献
79.