全文获取类型
收费全文 | 10151篇 |
免费 | 644篇 |
国内免费 | 24篇 |
专业分类
耳鼻咽喉 | 250篇 |
儿科学 | 750篇 |
妇产科学 | 165篇 |
基础医学 | 1079篇 |
口腔科学 | 134篇 |
临床医学 | 689篇 |
内科学 | 2265篇 |
皮肤病学 | 273篇 |
神经病学 | 1032篇 |
特种医学 | 298篇 |
外科学 | 1426篇 |
综合类 | 177篇 |
一般理论 | 2篇 |
预防医学 | 641篇 |
眼科学 | 177篇 |
药学 | 567篇 |
中国医学 | 15篇 |
肿瘤学 | 879篇 |
出版年
2023年 | 71篇 |
2022年 | 111篇 |
2021年 | 326篇 |
2020年 | 182篇 |
2019年 | 264篇 |
2018年 | 341篇 |
2017年 | 250篇 |
2016年 | 277篇 |
2015年 | 278篇 |
2014年 | 438篇 |
2013年 | 503篇 |
2012年 | 712篇 |
2011年 | 695篇 |
2010年 | 378篇 |
2009年 | 333篇 |
2008年 | 586篇 |
2007年 | 542篇 |
2006年 | 501篇 |
2005年 | 461篇 |
2004年 | 439篇 |
2003年 | 397篇 |
2002年 | 323篇 |
2001年 | 147篇 |
2000年 | 183篇 |
1999年 | 163篇 |
1998年 | 90篇 |
1997年 | 75篇 |
1996年 | 77篇 |
1995年 | 62篇 |
1994年 | 47篇 |
1993年 | 38篇 |
1992年 | 105篇 |
1991年 | 78篇 |
1990年 | 85篇 |
1989年 | 112篇 |
1988年 | 100篇 |
1987年 | 97篇 |
1986年 | 94篇 |
1985年 | 91篇 |
1984年 | 83篇 |
1983年 | 70篇 |
1982年 | 39篇 |
1981年 | 38篇 |
1979年 | 46篇 |
1978年 | 34篇 |
1977年 | 40篇 |
1975年 | 32篇 |
1974年 | 34篇 |
1972年 | 43篇 |
1969年 | 36篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
72.
73.
V Kochupillai S Sharma S Francis A Nanu S Mathew P Bhatia H Dua L Kumar S Aggarwal S Singh 《Thymus》1987,10(1-2):95-102
Forty patients with severe aplastic anaemia received an intravenous infusion of 0.004 to 11.1 x 10(8) (median: 8 x 10(8) hematopoietic cells prepared from the fetal livers of 8-32 week old abortuses. Five patients, who died within 15 days of fetal liver infusion, are excluded from analysis. Twenty-two of the 35 evaluable patients (62%) responded favourably. Six of the 7 patients with good response were alive after 9 to 44 months (median: m = 20); one died 106 months after fetal liver infusion due to renal lithiasis. Four of the 7 with moderate response were alive after 9 to 31 months; 3 died within 16 months. Of 8 patients with minimal response, one was lost to follow-up and the others died in 3.4 to 10 months (m = 6). Median survival of responders was 15.7 months. Bone marrow cellularity became normal in 12 patients following fetal liver infusion. In seven patients, there was a relapse; 6 regained a normal bone marrow cellularity after a second or third fetal liver infusion. These data strongly suggest a role of fetal liver infusion in inducing bone marrow recovery. Of 13 non-responders, 4 were lost to follow-up and 9 died within 20 days-4.3 months (m = 1.6). Fetal liver infusion appears to be an effective therapy in patients with severe aplastic anaemia. 相似文献
74.
75.
Gaidano G Vivenza D Forconi F Capello D Gloghini A Bhatia K Gutierrez M Gallicchio M Avanzi GC Fassone L Ariatti C Buonaiuto D Cingolani A Saglio G Tirelli U Larocca LM Dalla-Favera R Carbone A 《Genes, chromosomes & cancer》2000,27(2):177-182
Acquired immunodeficiency syndrome (AIDS)-related non-Hodgkin's lymphomas (AIDS-NHLs) consistently derive from B cells, are histologically heterogeneous, and are associated with distinct molecular pathways depending upon histology. Recently, it has been proposed that inactivating mutations of the bax death agonist may contribute to the pathogenesis of human tumors. In particular, among B-cell malignancies, BAX mutations have been detected at a certain frequency in Burkitt lymphomas. This study is aimed at defining the status of the BAX gene throughout the clinicopathologic spectrum of AIDS-NHL (n = 54), including AIDS-related Burkitt lymphoma (n = 14), AIDS-related Burkitt-like lymphoma (n = 8), AIDS-related diffuse large cell lymphoma (n = 15), AIDS-related primary central nervous system lymphoma (n = 6), and AIDS-related primary effusion lymphoma (n = 11). All 6 BAX exons and flanking sequences were subjected to mutational analysis by polymerase chain reaction-single strand conformation polymorphism followed by DNA direct sequencing of positive cases. Mutations of BAX among AIDS-NHL were restricted to a cell line of AIDS-related primary effusion lymphoma, which harbored a frameshift mutation causing the introduction of a proximal stop codon. All other AIDS-NHL displayed wild-type BAX alleles. In order to investigate whether BAX inactivation in AIDS-NHL may occur through mechanisms other than gene mutation, bax protein expression was investigated by Western blot analysis or immunohistochemistry in selected cases. All AIDS-NHL analyzed expressed normal bax proteins. Overall, this study indicates that deregulation of apoptotic control in AIDS-NHL is not caused by BAX alterations. Genes Chromosomes Cancer 27:177-182, 2000. 相似文献
76.
Meltem Yüksel Elma Baron Melissa Camouse Brenda W Cooper Hillard M Lazarus Stanton L Gerson Mary J Laughlin Kevin D Cooper Anita Gilliam Pingfu Fu Seth Stevens Omer N Ko? 《Biology of blood and marrow transplantation》2006,12(6):665-671
Whole-body UV-B phototherapy has been used for the treatment of graft-versus-host disease (GVHD) of the skin and has systemic immunosuppressive and tolerogenic effects. We hypothesized that whole-body UV-B therapy would improve donor engraftment and decrease the incidence and severity of GVHD that is associated with decreased intensity allogeneic hematopoietic stem cell transplantation. This study tested the feasibility of using UV-B phototherapy that was initiated before grafting and continued until engraftment to determine its effect on transplantation outcome. Eight patients (median age, 55.5 years; range, 32-65 years) with hematologic malignancies were included. Allogeneic peripheral blood stem cells were obtained from matched related (n=5) or matched unrelated (n=3) donors. Conditioning regimen was fludarabine 30 mg/m2 intravenously for 5 days, cyclophosphamide 1 g/m2/d intravenously for 2 days, and equine antithymocyte globulin 30 mg/kg/d for 2 days. GVHD prophylaxis included cyclosporine, methylprednisolone, and escalating doses of narrowband UV-B (311 nm) according to skin tolerance, 3 days a week, from 10 days before to 28 days after transplantation. The conditioning regimen and the UV-B therapy were well tolerated. Two patients received all 14 prescribed UV-B treatments (cumulative doses of 2000 and 3260 mJ/cm2, respectively) and 6 patients received 8 to 13 treatments with a cumulative dose range of 528-3465 mJ/cm2. There was a rapid decrease in epidermal CD1a+ cells by day of transplantation. Myeloid engraftment was rapid. One patient had secondary engraftment failure at 3 months and another had mixed chimerism at day 100. Seven of 8 patients developed severe acute GVHD (grade III, n=5; grade IV, n=2). Six had skin involvement, 5 had gastrointestinal involvement, and 1 had liver involvement. Four patients died (2 from sepsis, 1 from acute GVHD, and 1 from chronic GVHD). Four patients are alive (130-287 days), 3 with extensive chronic GVHD. We conclude that extended peritransplant UV-B therapy at the standard minimally erythemogenic dose is detrimental to the outcome of allogeneic stem cell transplantation. It is unclear how UV-B at this immunsuppressive dose might have altered skin and systemic cytokine and immune cell compositions in the host and increased GVHD- and treatment-related mortalities. Different UV-B dose and schedules should be further explored. However, although other phototherapeutic modalities may be effective against GVHD, extended UV-B therapy should not be used during early phases of decreased conditioning allogeneic transplantation. 相似文献
77.
78.
Differential expression of CD22 (Lyb8) on murine B cells 总被引:2,自引:0,他引:2
Erickson Loren D.; Tygrett Lorraine T.; Bhatia Sudershan K.; Grabstein Kenneth H.; Waldschmidt Thomas J. 《International immunology》1996,8(7):1121-1129
Previous studies have established the distribution, biochemistryand functional attributes of human CD22, a B cell-restrictedglycoprotein. Recently, molecular cloning of the murine CD22equivalent revealed this molecule to be the same as the previouslydescribed Lyb8 alloantigen. Using the anti-Lyb8 mAb Cy34.1.2,the present report documents the expression patterns of CD22within the murine B cell compartment. The results demonstratethat in the bone marrow, murine CD22 is absent on the surfaceof pro-B cells, pre-B cells and newly emerging lgM+ B cells.CD22 is present at a low density on immature IgMhi B cells andfully expressed on mature recirculating B cells. In the periphery,murine CD22 is expressed at mature levels on all B cell subsetsincluding follicular, marginal zone, B1 and switched B cells.Further studies showed CD22 to be retained on activated murineB cells for extended periods. Finally, in combination with CD23and heat stable antigen, CD22 can be used to delineate the immaturesplenic B cells, and distinguish them from follicular and marginalzone cells. Together, the results demonstrate murine CD22 tobe a useful pan marker for all mature B cell subsets. 相似文献
79.
Regulation of hepatocyte activator inhibitor-1 expression by androgen and oncogenic transformation in the prostate 下载免费PDF全文
Knudsen BS Lucas JM Fazli L Hawley S Falcon S Coleman IM Martin DB Xu C True LD Gleave ME Nelson PS Ayala GE 《The American journal of pathology》2005,167(1):255-266
Hepatocyte activator inhibitor-1 (HAI-1) is a transmembrane serine protease inhibitor that regulates the conversion of latent to active hepatocyte growth factor (HGF). Studies supporting a role for the HGF pathway in prostate carcinogenesis prompted an analysis of HAI-1 expression in the prostate. Here we analyze the regulation of HAI-1 expression by androgen, oncogenic transformation, and cancer progression. Immunohistochemical analysis revealed that HAI-1 expression was restricted to prostate epithelium, where staining occurred primarily in basal and atrophic luminal epithelial cells. Compared to normal glands, HAI-1 expression was significantly increased in localized prostate cancer and was present in most prostate cancer metastases. HAI-1 protein expression levels were sensitive to androgen in normal epithelium but not in cancer. Although androgen did not increase HAI-1 protein expression levels in LNCaP cells, it decreased HAI-1 surface expression, consistent with previous data from our group (Martin DB, Gifford DR, Wright ME, Keller A, Yi E, Goodlett DR, Aebersold R, Nelson PS: Quantitative proteomic analysis of proteins released by neoplastic prostate epithelium. Cancer Res 2004, 64:347-355). HAI-1 overexpression in cancer was predictive of prostate-specific antigen recurrence (relative risk, 1.24). These results suggest that HAI-1 regulates the HGF Met axis on prostate epithelial cells and influences HGF mediated tumor invasion and metastasis. 相似文献
80.
Isolated primary amyloid tumor of bone is rare; however, preoperative diagnosis can be rewarding because the prognosis is excellent. There are no clinical or roentgenographic criteria that can establish this diagnosis. There are few previous reports of fine-needle aspiration (FNA) where diagnosis of amyloidoma was made retrospectively. They describe the presence of extracellular hyaline material along with plasma cells and lymphocytes. A 35-year-old female was referred to the FNA clinic with swelling in the right upper chest wall. Radiologic findings revealed a destructive lytic lesion involving the bodies of D1 and D2 vertebrae with extension into surrounding soft tissue. Repeated FNA smears were hypocellular but had abundant homogeneous flocculent material, which stained positive with Congo red. A few plasma cells and foreign-body giant cells were also seen. We conclude that preoperative FNA cytology diagnosis of amyloid tumor is possible. Hypocellular smears with flocculent material, plasma cells, and foreign-body giant cells in absence of granulation tissue should suggest the diagnosis. 相似文献