全文获取类型
收费全文 | 3544篇 |
免费 | 236篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 20篇 |
儿科学 | 142篇 |
妇产科学 | 56篇 |
基础医学 | 512篇 |
口腔科学 | 63篇 |
临床医学 | 314篇 |
内科学 | 731篇 |
皮肤病学 | 43篇 |
神经病学 | 429篇 |
特种医学 | 116篇 |
外科学 | 531篇 |
综合类 | 50篇 |
一般理论 | 7篇 |
预防医学 | 242篇 |
眼科学 | 40篇 |
药学 | 261篇 |
中国医学 | 14篇 |
肿瘤学 | 215篇 |
出版年
2024年 | 6篇 |
2023年 | 36篇 |
2022年 | 62篇 |
2021年 | 123篇 |
2020年 | 88篇 |
2019年 | 118篇 |
2018年 | 129篇 |
2017年 | 71篇 |
2016年 | 94篇 |
2015年 | 111篇 |
2014年 | 168篇 |
2013年 | 182篇 |
2012年 | 284篇 |
2011年 | 282篇 |
2010年 | 184篇 |
2009年 | 143篇 |
2008年 | 227篇 |
2007年 | 226篇 |
2006年 | 240篇 |
2005年 | 196篇 |
2004年 | 203篇 |
2003年 | 165篇 |
2002年 | 152篇 |
2001年 | 12篇 |
2000年 | 14篇 |
1999年 | 14篇 |
1998年 | 33篇 |
1997年 | 22篇 |
1996年 | 16篇 |
1995年 | 22篇 |
1994年 | 16篇 |
1993年 | 8篇 |
1992年 | 9篇 |
1991年 | 11篇 |
1990年 | 4篇 |
1989年 | 6篇 |
1988年 | 6篇 |
1987年 | 11篇 |
1986年 | 13篇 |
1985年 | 10篇 |
1984年 | 5篇 |
1982年 | 6篇 |
1981年 | 7篇 |
1979年 | 6篇 |
1978年 | 8篇 |
1977年 | 5篇 |
1975年 | 3篇 |
1973年 | 4篇 |
1972年 | 3篇 |
1971年 | 4篇 |
排序方式: 共有3786条查询结果,搜索用时 15 毫秒
31.
Franziska Kluschke Steffen Ross Patricia M. Flach Wolf Schweitzer Garyfalia Ampanozi Dominic Gascho Bruno Vonlanthen Michael J. Thali Thomas D. Ruder 《Legal medicine (Tokyo, Japan)》2013,15(5):256-259
We present a case of a ruptured abdominal aortic aneurysm (AAA) with ambiguous accessory findings on post-mortem computed-tomography (PMCT), post-mortem magnetic resonance (PMMR) imaging, and PMCT-angiography (PMCTA) suggestive of thoracic aortic dissection. The diagnosis of ruptured AAA was confirmed by autopsy; however, there was no aortic dissection. The imaging findings that mimicked the presence of aortic dissection might have been an atypical presentation of post-mortem clotting or sedimentation. This case is an ideal example to illustrate benefits, limitations, and challenges of post-mortem cross-sectional imaging. It serves as a reminder that both, training as well as correlation of imaging findings with autopsy are fundamental to improve our understanding of radiologic findings on post-mortem cross-sectional imaging. 相似文献
32.
OBJECTIVE: This analysis evaluates the cost-effectiveness of valaciclovir prophylaxis using clinically and economically important health outcomes including graft failure, life-years, and quality-adjusted life-years (QALYs). METHODS: A Markov model was developed using a randomized, placebo-controlled trial of valaciclovir prophylaxis, together with a published epidemiological study and national renal transplant registry data. The model's population was stratified into two risk groups by donor/recipient cytomegalovirus (CMV) serostatus at transplantation: donor-positive/recipient-negative (D+R-) and recipient-positive (R+) patients. The model estimated costs and health outcomes over a 30-yr period from the perspective of Australian health care providers. RESULTS: The total health care cost was $3619 lower for D+R- patients receiving valaciclovir prophylaxis compared with those not receiving prophylaxis. D+R- patients receiving valaciclovir gained an extra 0.33 yr of life and 0.27 QALYs. R+ patients receiving valaciclovir prophylaxis gained an extra 0.07 yr of life and 0.05 QALYs, with an incremental cost of $914. This equates to $17 127 per QALY gained, which is highly cost-effective compared with other drugs and health interventions. CONCLUSIONS: Valaciclovir for the prophylaxis of CMV disease in renal transplant recipients is a cost-effective intervention, significantly reducing the burden of CMV disease to patients and health care providers. 相似文献
33.
Nonaka D Rosai J Spagnolo D Fiaccavento S Bisceglia M 《The American journal of surgical pathology》2004,28(8):1070-1075
Four cases of solitary cylindroma of the breast of skin adnexal type are described. The tumors were morphologically and immunophenotypically identical to their dermal counterparts. They arose in close proximity to the nipple, such as the retroareolar area of the breast and in intimate association with the lactiferous ducts, suggesting an origin from the latter structures. One case occurred in a woman with hereditary multiple cylindromatosis (Brooke-Spiegler syndrome). This is the second reported case of this hereditary syndrome with extracutaneous manifestations and the first case in which the breast is involved. 相似文献
34.
Young E. Whang Andrew J. Armstrong W. Kimryn Rathmell Paul A. Godley William Y. Kim Raj S. Pruthi Eric M. Wallen Jeffrey M. Crane Dominic T. Moore Gayle Grigson Karla Morris Catharine P. Watkins Daniel J. George 《Urologic oncology》2013,31(1):82-86
ObjectivesEpidermal growth factor receptor (EGFR) and HER-2 tyrosine kinases may be involved in activation of androgen receptor and progression of prostate cancer. They represent potential therapeutic targets in prostate cancer. Lapatinib is an oral inhibitor of EGFR and HER-2. The objective of this study is to assess the preliminary clinical efficacy of lapatinib in the therapy of castration-resistant prostate cancer.MethodsIn this multicenter, open-label trial, patients with rising PSA on androgen deprivation therapy and not having received chemotherapy were eligible. They were treated with lapatinib at a dose of 1,500 mg once daily. The primary end point was a >50% confirmed PSA decline from baseline; safety, tolerability, and time to PSA progression were secondary outcomes.ResultsTwenty-nine patients enrolled in the study had a median age of 73 years and a baseline PSA of 21.6 ng/ml. Seven patients had no radiologic evidence of metastatic disease, while the remaining patients had bone or measurable disease or both. Treatment was well tolerated with only grade 3 treatment-related toxicities being diarrhea (14%) and rash (3%). One of 21 evaluable patients had >50% reduction in PSA, while another patient had 47% reduction in PSA with an ongoing duration of response of 45+ months. The median time to PSA progression was 29 days.ConclusionsLapatinib showed single agent activity in a small subset of unselected patients with castration-resistant prostate cancer, as measured by PSA. Future trials should explore a trial design with time-to-event end points and predictive biomarkers and a combination with other agents. 相似文献
35.
Michael G. Sarr Charles J. Billington Roy Brancatisano Anthony Brancatisano James Toouli Lilian Kow Ninh T. Nguyen Robin Blackstone James W. Maher Scott Shikora Dominic N. Reeds J. Christopher Eagon Bruce M. Wolfe Robert W. O’Rourke Ken Fujioka Mark Takata James M. Swain John M. Morton Sayeed Ikramuddin Michael Schweitzer Bipan Chand Raul Rosenthal 《Obesity surgery》2012,22(11):1771-1782
Background
Intermittent, reversible intraabdominal vagal blockade (VBLOC? Therapy) demonstrated clinically important weight loss in feasibility trials. EMPOWER, a randomized, double-blind, prospective, controlled trial was conducted in USA and Australia.Methods
Five hundred three subjects were enrolled at 15 centers. After informed consent, 294 subjects were implanted with the vagal blocking system and randomized to the treated (n?=?192) or control (n?=?102) group. Main outcome measures were percent excess weight loss (percent EWL) at 12?months and serious adverse events. Subjects controlled duration of therapy using an external power source; therapy involved a programmed algorithm of electrical energy delivered to the subdiaphragmatic vagal nerves to inhibit afferent/efferent vagal transmission. Devices in both groups performed regular, low-energy safety checks. Data are mean ± SEM.Results
Study subjects consisted of 90?% females, body mass index of 41?±?1?kg/m2, and age of 46?±?1?years. Device-related complications occurred in 3?% of subjects. There was no mortality. 12-month percent EWL was 17?±?2?% for the treated and 16?±?2?% for the control group. Weight loss was related linearly to hours of device use; treated and controls with ??12?h/day use achieved 30?±?4 and 22?±?8?% EWL, respectively.Conclusions
VBLOC? therapy to treat morbid obesity was safe, but weight loss was not greater in treated compared to controls; clinically important weight loss, however, was related to hours of device use. Post-study analysis suggested that the system electrical safety checks (low charge delivered via the system for electrical impedance, safety, and diagnostic checks) may have contributed to weight loss in the control group. 相似文献36.
Matrix metalloproteinases in ascending aortic aneurysms: bicuspid versus trileaflet aortic valves 总被引:3,自引:0,他引:3
LeMaire SA Wang X Wilks JA Carter SA Wen S Won T Leonardelli D Anand G Conklin LD Wang XL Thompson RW Coselli JS 《The Journal of surgical research》2005,123(1):40-48
BACKGROUND: Abnormal matrix metalloproteinase (MMP) and tissue inhibitor of metalloproteinase (TIMP) expression contributes to the development of abdominal aortic aneurysms. Recent data suggest that MMP-2 and MMP-9 may also play a role in thoracic aortic disease. We sought to determine (1) whether ascending aortic aneurysms are associated with increased MMP expression and (2) whether aortic inflammation and MMP expression differ between patients with congenital bicuspid aortic valves (BAVs) and those with trileaflet aortic valves (TAVs). MATERIALS AND METHODS: Samples of ascending aortic aneurysms were obtained from 29 patients; 14 patients had BAVs and 15 had TAVs. Control ascending aorta was obtained from 14 organ donors or heart transplant recipients. Aortic histology and immunohistochemistry were performed to evaluate elastin degradation, inflammatory changes, and MMP-2 and MMP-9 expression. Aortic levels of MMP-2, MMP-9, TIMP-1, and TIMP-2 were measured using ELISA. RESULTS: Aneurysms in the TAV patients exhibited marked inflammation, high CD68 expression, diminished elastin content, increased MMP-9 expression, and normal MMP-2 levels. In contrast, BAV aneurysms were characterized by a relative lack of inflammation, preservation of elastin content, normal MMP-9 levels, and elevated MMP-2 expression. TIMP-1 and TIMP-2 levels were not significantly different among the three groups. CONCLUSIONS: Ascending aortic aneurysms exhibited increased MMP expression. The pattern of MMP expression and the degree of inflammation, however, differed between aneurysms associated with BAVs and those with TAVs. Variations in the molecular mechanisms underlying different types of thoracic aortic aneurysms warrant further investigation. 相似文献
37.
Incidence and Characteristics of Atypical Femoral Fractures: Clinical and Geometrical Data 下载免费PDF全文
Zeineb Mahjoub Sonia Jean Jean‐Thomas Leclerc Jacques P Brown Dominic Boulet Stéphane Pelet Charlotte Grondin Jeannette Dumont Étienne L Belzile Laetitia Michou 《Journal of bone and mineral research》2016,31(4):767-776
Despite the multitude of studies published on atypical femoral fractures (AFFs), a profile for patients at risk does not exist. This study aimed first at estimating AFF incidence over a 19‐month‐period in Quebec City using the ASBMR Task force criteria to define AFF. The medical records of patients hospitalized for hip or femoral fracture between June 1, 2009, and December 31, 2010, were reviewed. Thirty‐six cases of atypical fractures were identified during the 19‐month period, representing an AFF incidence of 7.0 (range, 4.7 to 9.3) cases per 100,000 person‐years. In the second part of the study, data regarding the characteristics suspected of increasing the risks of AFF were collected from medical and pharmacological records, proximal femur radiographs, and patient interviews. The data regarding each patient with an AFF during years 2008‐2011 were compared to two controls with a hip or femoral fragility fracture or a traumatic fracture, paired for age and sex. Twenty patients with AFF were added to the 36 patients with AFF selected in the first part, thereby 56 patients with AFF were investigated. The association between the occurrence of AFF and bisphosphonates (BPs) use was proven statistically significant in multivariate analysis, odds ratio (OR) = 10.39 (95% CI, 2.22 to 48.58; p = 0.0029). Compared to controls, patients with AFF had excessive femoral offset (43.1 mm versus 38.3 mm, p = 0.0007), proximal femoral neck angle in varus (128.9 degrees versus 134.0 degrees, p < 0.0001), and had greater proximal cortical thickness. This retrospective study confirms the low incidence of AFF, confirms its significant association with exposure to BPs, and reveals the possible contribution of proximal femoral geometry in AFF occurrence. © 2016 American Society for Bone and Mineral Research. 相似文献
38.
39.
Growth of bone marrow stromal cells on small intestinal submucosa: an alternative cell source for tissue engineered bladder 总被引:6,自引:0,他引:6
OBJECTIVE: To assess the potential use of bone marrow stromal cell (BMSC)-seeded biodegradable scaffold for bladder regeneration in a canine model, by characterizing BMSCs and comparing them to bladder smooth muscle cells (SMCs) by immunohistochemistry, growth capability, and contractility. MATERIALS AND METHODS: Bone marrow was taken by direct needle aspiration from the femurs of five beagle dogs for the in vitro study. Mononuclear cells were isolated by Ficoll-Paque density gradient centrifugation and cultivated in medium 199 with 10% fetal bovine serum. BMSCs were characterized by cell proliferation, in vitro contractility, immunohistochemical analysis, and the growth pattern on small intestinal submucosa (SIS) scaffolds compared to bladder SMC cultures from the same dogs. Another six dogs had a hemicystectomy and bladder augmentation with BMSC-seeded (two), bladder cells including urothelial cells plus SMC-seeded SIS (two) and unseeded SIS scaffolds (two). The six dogs were followed for 10 weeks after augmentation. RESULTS: In vitro BMSCs had a significant contractile response to calcium-ionophore, with a mean (sem) 36 (2)%, relative contraction (P < 0.01), which was similar to bladder SMCs but markedly different from fibroblasts. BMSCs also expressed alpha-smooth muscle actin by immunohistochemical staining and Western blotting, but did not express desmin or myosin. In vivo, both BMSC-seeded and bladder cell-seeded SIS grafts had solid smooth-muscle bundle formation throughout the graft. CONCLUSIONS: BMSCs had a similar cell proliferation, histological appearance and contractile phenotype as primary cultured bladder SMCs. SIS supported three-dimensional growth of BMSCs in vitro, and BMSC-seeded SIS scaffold promoted bladder regeneration in a canine model. BMSCs may serve as an alternative cell source in urological tissue engineering. 相似文献
40.
Paniagua R Si MS Flores MG Rousvoal G Zhang S Aalami O Campbell A Changelian PS Reitz BA Borie DC 《Transplantation》2005,80(9):1283-1292
BACKGROUND: Janus Kinase (JAK) 3 is a tyrosine kinase essential for proper signal transduction downstream of selected cytokine receptors and for robust T-cell and natural killer cells activation and function. JAK3 inhibition with CP-690,550 prevents acute allograft rejection. To provide further insight into the mechanisms of efficacy, we investigated the immunomodulatory effects of CP-690,550 in vitro and in vivo in nonhuman primates. METHODS: Pharmacodynamic assessments of lymphocyte activation, function, proliferation and phenotype were performed in three settings: in vitro in whole blood isolated from untransplanted cynomolgus monkeys (cynos), in vivo in blood from untransplanted cynos dosed with CP-690,550 for 8 days, and in vivo in blood from transplanted cynos immunosuppressed with CP-690,550. Cell surface activation markers expression, IL-2- enhanced IFN-gamma production, lymphocyte proliferation and immune cell phenotype analyzes were performed with multiparametric flow cytometry. RESULTS: In vitro exposure to CP-690,550 resulted in significant reduction of IL-2-enhanced IFN-gamma production by T-cells (maximum inhibition of 55-63%), T-cell surface expression of CD25 (50% inhibitory concentration (IC50); 0.18 microM) and CD71 (IC50; 1.6 microM), and T-cell proliferative capacities measured by proliferating cell nuclear antigen expression (IC50; 0.87 microM). Similar results were observed in animals dosed with CP-690,550. In addition, transplanted animals displayed significant reduction of NK cell (90% from baseline) and T-cell numbers whereas CD8 effector memory T-cell populations were unaffected. CONCLUSIONS: Potent in vitro and in vivo immunomodulatory effects of the JAK3 inhibitor CP-690,550 likely contribute to its efficacy in the prevention of organ allograft rejection. 相似文献