全文获取类型
收费全文 | 6620篇 |
免费 | 480篇 |
国内免费 | 40篇 |
专业分类
耳鼻咽喉 | 44篇 |
儿科学 | 199篇 |
妇产科学 | 73篇 |
基础医学 | 921篇 |
口腔科学 | 229篇 |
临床医学 | 648篇 |
内科学 | 1682篇 |
皮肤病学 | 140篇 |
神经病学 | 484篇 |
特种医学 | 454篇 |
外科学 | 899篇 |
综合类 | 117篇 |
一般理论 | 1篇 |
预防医学 | 324篇 |
眼科学 | 127篇 |
药学 | 405篇 |
中国医学 | 5篇 |
肿瘤学 | 388篇 |
出版年
2021年 | 60篇 |
2018年 | 81篇 |
2017年 | 78篇 |
2016年 | 78篇 |
2015年 | 79篇 |
2014年 | 121篇 |
2013年 | 204篇 |
2012年 | 190篇 |
2011年 | 204篇 |
2010年 | 131篇 |
2009年 | 136篇 |
2008年 | 226篇 |
2007年 | 217篇 |
2006年 | 209篇 |
2005年 | 189篇 |
2004年 | 159篇 |
2003年 | 169篇 |
2002年 | 155篇 |
2001年 | 207篇 |
2000年 | 193篇 |
1999年 | 182篇 |
1998年 | 141篇 |
1997年 | 141篇 |
1996年 | 143篇 |
1995年 | 106篇 |
1994年 | 104篇 |
1993年 | 108篇 |
1992年 | 175篇 |
1991年 | 169篇 |
1990年 | 171篇 |
1989年 | 202篇 |
1988年 | 178篇 |
1987年 | 155篇 |
1986年 | 154篇 |
1985年 | 126篇 |
1984年 | 108篇 |
1983年 | 72篇 |
1982年 | 71篇 |
1981年 | 82篇 |
1980年 | 85篇 |
1979年 | 85篇 |
1978年 | 83篇 |
1977年 | 71篇 |
1976年 | 78篇 |
1975年 | 69篇 |
1972年 | 67篇 |
1970年 | 65篇 |
1965年 | 67篇 |
1964年 | 56篇 |
1960年 | 70篇 |
排序方式: 共有7140条查询结果,搜索用时 15 毫秒
21.
22.
JC Sitek† M Loeb‡ JR Ronnevig¶ 《Journal of the European Academy of Dermatology and Venereology》2007,21(7):891-896
BACKGROUND: Since 1997, a number of trials have shown promising results in treating generalized vitiligo with narrowband ultraviolet B (UVB) both in adults and children. However, there is little knowledge concerning the duration and permanency of the treatment-induced repigmentation. OBJECTIVE: Our main objective was to perform a follow-up trial of successfully treated patients receiving narrowband UVB for generalized vitiligo. METHODS: We have investigated to what degree the treatment-induced repigmentation remains stable for up to 2 years post-treatment. We performed an initial open trial including 31 patients with generalized vitiligo. They received narrowband UVB thrice weekly for up to 12 months. Patients experiencing > 75% repigmentation were defined responders and were included in the follow-up trial. Responders were followed every 6 months for up to 2 years after cessation of treatment. We observed the pigmentation status and registered any changes indicating loss of pigmentation and relapse. RESULTS: Eleven of the 31 treated patients were included in the follow-up trial. Six patients had relapse and five patients had stable response 24 months after cessation of treatment. Four out of six relapses were within 6 months post-treatment. CONCLUSION: In our study population of 31 patients with generalized vitiligo, five patients (16%) experienced > 75% stable repigmentation 2 years after cessation of a treatment programme of up to 1 years narrowband UVB therapy. 相似文献
23.
Eran Maman David M. Steinberg Batia Stark Shai Izraeli Shlomo Wientroub 《Journal of children's orthopaedics》2007,1(1):63-68
Purpose Studies on musculoskeletal manifestations (MSM) of childhood acute lymphoblastic leukemia (ALL) have yielded variable findings
with regard to their clinical impact. We investigated the significance for differential diagnosis, treatment and outcome of
musculoskeletal complaints as presenting symptoms of ALL, and their correlation with leukemia immunophenotypes, for which
data is lacking.
Methods Data on 783 children in the national study for childhood ALL between 1984 and 2003 were reviewed retrospectively. Statistical
analysis examined possible relationships between MSM at the time of diagnosis and demographic and clinical data, biological
features of leukemia (peripheral blood counts, immunophenotype and main cytogenetic aberration), response to initial prednisone
treatment, and outcome.
Results Of 765 children with data on orthopaedic complaints, 240 presented with MSM (31.4%). Among these children, B cell precursor
(BCP) was much more common (209/576, 36.3%) than T cell ALL (25/176, 14.2%). Patients with MSM had lower white blood cell
counts (WBC) (median of 9 vs. 20 × 109/L, P < 0.001) and percentage of blast cells in the peripheral blood at diagnosis compared to those without (median of 27 vs. 53%,
P < 0.001). Hepatomegaly and splenomegaly were less common in MSM group (67 vs. 53% <3 cm, P < 0.001, and 63 vs. 50% <3 cm, P < 0.001, respectively). Poor response to initial treatment with prednisone was recorded in 7.1% of patients with MSM versus
11.5% of those without (P = 0.086). The analysis revealed no independent effect of MSM on event-free survival (EFS), after correcting for differences
in EFS related to immunophenotype or initial WBC.
Conclusions MSM occur mostly in children with BCP ALL who present with less involvement of extramedullary organs, low peripheral blood
blasts and white blood cells counts. These findings highlight the importance of including ALL in the differential diagnosis
of MSM even in the presence of an apparently normal peripheral blood count. Our study also suggests that MSM are caused by
leukemic cells with enhanced biological propensity to remain relatively confined within the intramedullary bone-marrow space. 相似文献
24.
P. Muiesan W. Jassem R. Girlanda R. Steinberg H. Vilca-Melendez G. Mieli-Vergani A. Dhawan M. Rela N. Heaton 《American journal of transplantation》2006,6(5P1):1012-1016
We report our experience of pediatric liver transplantation with partial grafts from non-heart beating donors (NHBD). Controlled donors less than 40 years of age with a warm ischemia time (WI) of less than 30 min were considered for pediatric recipients. Death was declared 5 min after asystole. A super-rapid recovery technique with aortic and portal perfusion was utilized. Mean donor age was 29 years and WI 14.6 min (range 11–18). Seven children, mean age 4.9 years (0.7–11), median weight 20 kg (8.4–53) received NHBD segmental liver grafts. Diagnoses included seronegative hepatitis, neonatal sclerosing cholangitis, familial intrahepatic cholestasis, hepatoblastoma, primary hyperoxaluria and factor VII deficiency (n = 2).The grafts included four reduced and one split left lateral segments, one left lobe and one right auxiliary graft. Mean cold ischemia was 7.3 h (6.2–8.8). Complications included one pleural effusion and one biliary collection drained percutaneously. At 20 months (10–36) follow-up all children are alive and well with functioning grafts.
Donation after cardiac death is a significant source of liver grafts for adults and children with careful donor selection and short cold ischemic times. 相似文献
Donation after cardiac death is a significant source of liver grafts for adults and children with careful donor selection and short cold ischemic times. 相似文献
25.
Neuroimaging in Pineal Tumors 总被引:4,自引:0,他引:4
F Reis MD AV Faria MD PhD VA Zanardi MD PhD JR Menezes MD F Cendes MD PhD LS Queiroz MD PhD 《Journal of neuroimaging》2006,16(1):52-58
BACKGROUND AND PURPOSE: The authors report radiological findings in 11 tumors in the pineal region, which were histologically diagnosed as germinomas, pineocytomas pineoblastomas, ependymomas, teratomas, and astrocytomas. METHODS: Computed tomography (CT) was performed in seven patients and magnetic resonance imaging (MRI) was performed in all patients. RESULTS: CT showed a solid or solid/cystic mass with variable contrast enhancement. MRI showed a heterogeneous mass, with hypointense signal on T1 and iso/hyperintense signal on T2-weighted images (WI) and gadolinium enhancement. Extension to adjacent structures occurred in five patients and spread through the cerebral spinal fluid (CSF) in two. CONCLUSIONS: Pineal region tumors have no pathognomonic imaging pattern. MRI and CT are complementary in diagnosis and are important to determine localization, extension, and meningeal spread. 相似文献
26.
Interrupting reperfusion as a stroke therapy: ischemic postconditioning reduces infarct size after focal ischemia in rats. 总被引:18,自引:0,他引:18
Heng Zhao Robert M Sapolsky Gary K Steinberg 《Journal of cerebral blood flow and metabolism》2006,26(9):1114-1121
Cerebral ischemic preconditioning protects against stroke, but is clinically feasible only when the occurrence of stroke is predictable. Reperfusion plays a critical role in cerebral injury after stroke; we tested the hypothesis that interrupting reperfusion lessens ischemic injury. We found for the first time that such postconditioning with a series of mechanical interruptions of reperfusion significantly reduces ischemic damage. Focal ischemia was generated by permanent distal middle cerebral artery (MCA) occlusion plus transient bilateral common carotid artery (CCA) occlusion. After 30 secs of CCA reperfusion, ischemic postconditioning was performed by occluding CCAs for 10 secs, and then allowing for another two cycles of 30 secs of reperfusion and 10 secs of CCA occlusion. Infarct size was measured 2 days later. Cerebral blood flow (CBF) was measured in animals subjected to permanent MCA occlusion plus 15 mins of bilateral CCA occlusion, which demonstrates that postconditioning disturbed the early hyperemia immediately after reperfusion. Postconditioning dose dependently reduced infarct size in animals subjected to permanent MCA occlusion combined with 15, 30, and 60 mins of bilateral CCA occlusion, by reducing infarct size approximately 80%, 51%, and 17%, respectively. In addition, postconditioning blocked terminal deoxynucleotidyl transferase-mediated uridine 5'-triphosphate-biotin nick end labeling-positive staining, a marker of apoptosis, in the penumbra 2 days after stroke. Furthermore, in situ superoxide detection using hydroethidine suggested that postconditioning attenuated superoxide products during early reperfusion after stroke. In conclusion, postconditioning reduced infarct size, most plausibly by blocking apoptosis and free radical generation. With further study it may eventually be clinically applicable for stroke treatment. 相似文献
27.
Best-practice algorithms for the use of a bilayered living cell therapy (Apligraf® ) in the treatment of lower-extremity ulcers 总被引:1,自引:0,他引:1
Joseph Cavorsi MD FACS ; Frank Vicari MD FACS FAAP ; Douglas J. Wirthlin MD FACS ; William Ennis DO MBA FACOS ; Robert Kirsner MD ; Sean M. O''Connell PhD ; John Steinberg DPM ; Vincent Falanga MD 《Wound repair and regeneration》2006,14(2):102-109
Tissue-engineered skin substitutes such as Apligraf have emerged over the past 20 years as among the most carefully studied and efficacious of the advanced wound modalities. These products have been proven as effective enhancements to general wound care, promoting wound closure particularly in instances where conventional wound care fails. Marketed for hard-to-heal wounds since 1998, Apligraf has become part of standard wound care in many wound centers across the United States. Despite this situation, few general wound care guidelines incorporate advanced and active wound-healing technologies, such as tissue-engineered skin products. Because of this deficiency, appropriate patient selection and proper use of these product remain largely unaddressed within the general wound care community. Here, we describe the development of guidelines surrounding optimal use of the bilayered living cell therapy, Apligraf, in the treatment of the two types of lower extremity ulcers for which the product is FDA approved: venous leg ulcer and diabetic foot ulcer. The guidelines detailed in this article focus on the identification and selection of patients who are at risk for failure of standard wound care therapy and thus appropriate for Apligraf treatment. The intended audience for these guidelines is the general wound care practitioner, for whom the developed treatment algorithms and accompanying figure legends should provide practical, user-friendly direction simplifying both patient selection and appropriate use of Apligraf within the context of good wound-healing practice. 相似文献
28.
Although cardiac arrhythmias remain a serious clinical problem in many patients with heart disease, the exact role of antiarrhythmic drug therapy is currently under intense evaluation. Within the last several years it has become clear that there are significant risks as well as potential benefits associated with existing agents. Ongoing studies in large patient populations should help determine the benefit/risk ratio of traditional therapy. Regardless of the outcome of these trials, current electrophysiological dogma will have to be re-evaluated and newer concepts evolve for drug development to make further progress. The goal of this symposium is to exchange information among basic and clinical investigators so as to facilitate the emergence of novel electrophysiological concepts that will form the basis for future generations of antiarrhythmic drugs. 相似文献
29.
30.
Immunopathology of glomerulonephritis associated with chronic woodchuck hepatitis virus infection in woodchucks (Marmota monax).
下载免费PDF全文
![点击此处可从《The American journal of pathology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
D. N. Peters H. Steinberg W. I. Anderson W. E. Hornbuckle P. J. Cote J. L. Gerin R. M. Lewis B. C. Tennant 《The American journal of pathology》1992,141(1):143-152
Retrospective analysis of necropsy findings of 705 woodchucks was performed to determine the prevalence and morphology of immune-mediated glomerulonephritis, its relationship to woodchuck hepatitis virus (WHV) infection, and the presence of major WHV antigens. Twenty-six woodchucks had glomerular lesions. Renal tissue of the 26 animals was evaluated histologically and immunohistochemically for immune-mediated glomerulonephritis. Of these 26 animals, immune-mediated glomerulonephritis was diagnosed in six, all of which were chronic WHV carriers. Membranous glomerulonephritis was identified in three animals, two of which also had mesangial proliferation. Host immunoglobulin was present within the mesangium and along capillary loops in all three. Woodchuck hepatitis virus core antigen (WHcAg) was present along capillary loops of two of these animals, one membranous and one mixed, and in the mesangium of all three. Woodchuck hepatitis virus surface antigen (WHsAg) deposition was similar to WHcAg deposition but was only present along capillaries in those animals with mixed nephritis. The remaining three animals had mesangial proliferation. WHsAg and host immunoglobulin deposition were predominately mesangial; WHcAg was not detected. Transmission electron microscopy showed thickening of the capillary loop basement membranes and subepithelial electron-dense deposits in animal one, and deposits in the mesangium in animal six. 相似文献