首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   225篇
  免费   15篇
  国内免费   13篇
耳鼻咽喉   1篇
儿科学   21篇
妇产科学   1篇
基础医学   18篇
口腔科学   6篇
临床医学   24篇
内科学   63篇
皮肤病学   3篇
神经病学   4篇
特种医学   64篇
外科学   8篇
综合类   8篇
预防医学   4篇
药学   8篇
肿瘤学   20篇
  2021年   1篇
  2020年   2篇
  2019年   1篇
  2018年   3篇
  2017年   2篇
  2016年   2篇
  2015年   4篇
  2014年   4篇
  2013年   3篇
  2011年   2篇
  2010年   11篇
  2009年   12篇
  2008年   4篇
  2007年   10篇
  2005年   4篇
  2004年   2篇
  2003年   6篇
  2002年   1篇
  2001年   1篇
  2000年   3篇
  1999年   2篇
  1998年   15篇
  1997年   13篇
  1996年   13篇
  1995年   10篇
  1994年   17篇
  1993年   13篇
  1992年   3篇
  1991年   3篇
  1990年   6篇
  1989年   12篇
  1988年   9篇
  1987年   10篇
  1986年   6篇
  1985年   5篇
  1984年   4篇
  1983年   6篇
  1982年   4篇
  1981年   6篇
  1980年   4篇
  1979年   1篇
  1978年   6篇
  1977年   3篇
  1976年   4篇
排序方式: 共有253条查询结果,搜索用时 15 毫秒
21.
22.
Leucocytoclastic vasculitis associated with hepatitis C virus antibodies   总被引:1,自引:1,他引:0  
The actiopathogenesis of leucocytoclastic vasculitis is still unknown, but recently hepatitis C virus (HCV) has been suggested as trigger of autoimmunity. We report a case of a 26-yr-old patient with purpura due to leucocytoclastic vasculitis associated with hepatitis C virus infection. Laboratory findings showed AST, ALT, gamma GT within normal limits, positive antibodies to HCV (IIF and Riba II) and polymerase chain reaction for HCV RNA. Anti-nuclear antibodies, IgG and IgM anti- cardiolipin antibodies, anti-platelet antibodies and anti-neutrophil cytoplasmic antibodies with perinuclear pattern were also present. A skin biopsy specimen of a purpuric lesion showed leucocytoclastic vasculitis with small vessel thrombosis and perivascular deposition of IgM and fibrinogen on immunofluorescence study. This case shows a role of HCV in leucocytoclastic vasculitis; it is possible that this HCV can induce autoimmunity independently of cryoglobulins and liver involvement.   相似文献   
23.
梅尼埃病 (m啨ni埁re’sdisease,MD)的治疗目前仍然是耳科临床上的难题之一 ,主要是因为其病因尚未完全弄清。近年来的耳免疫学研究显示免疫病理学因素在MD的发病中可能起着重要的作用 ,部分患者的发病可能与内耳自身免疫性病变有关。最近 ,我们对 7例 (耳 )慢性化脓性中耳乳突炎(CSOM)伴对侧MD患者行免疫学检查并与 1 0例(耳 )CSOM不伴MD患者进行对照 (对照组 ) ,借以探讨MD发病的免疫学因素。报告如下。1 资料与方法1 .1   临床资料CSOM伴MD组 :7例CSOM伴对侧MD患者 ,男 2例 ,女 5例 ;平均…  相似文献   
24.
Farace  MG; Ullu  E; Fantoni  A; Rossi  GB; Cioe  L; Dolei  A 《Blood》1979,53(1):134-141
The poly (A)-containing nuclear RNA from dimethylsulfoxide-induced Friend leukemia cells was fractionated by acrylamide gel electrophoresis in denaturing conditions and analyzed for alpha and beta globin RNA sequences. The results indicate that nuclear RNA contains one species of large-size RNA (0.6 X 10(6) daltons), which is the putative precursor for beta globin mRNA only. In addition, it was shown by electrophoretic analysis that the complex of RNA molecules not resolved by sucrose gradient centrifugation (11S) comprises sequences of decreasing size (0.34, 0.28, and 0.26 X 10(6) daltons), which might be the precursors of alpha and beta globin mRNA.  相似文献   
25.
In an attempt to improve the poor outlook for children with T-cell leukemia (T-ALL), the Southwest Oncology Group, Pediatric Division, used a modified LSA2-L2 multidrug regimen to treat 53 patients with E- rosette-positive T-ALL. This regimen was chosen because of its demonstrated efficacy in T-cell (mediastinal) non-Hodgkin's lymphoma. Complete remission (CR) rate was 88%. Range of follow-up for those patients remaining in CR is 24-49 mo (median 39 mo). Life table analysis estimates that 40% (SE 8.3%) of all patients who started induction therapy will remain failure-free at 3 yr. For patients achieving CR, 46% (SE 9%) are projected to remain in both marrow and extramedullary CR at 3 yr. Median failure-free duration was 13 mo, but only 1 patient has relapsed beyond 16 mo. Twenty-nine percent of initial relapses were isolated CNS relapses. The following presenting factors did not relate significantly to outcome: hemoglobin, platelet count, uric acid, race, and mediastinal mass. Age greater than 10 yr was a poor prognosis indicator only in the less than 50,000/microliter WBC group. Sex was not a significant factor after adjusting for WBC. WBC was the most important prognostic factor: 19% (SE 8%) of patients with WBC greater than 50,000/microliter are projected to remain failure- free at 3 yr as compared to 67% (SE 11%) of patients with WBC less than 50,000/microliter. Although the overall results are better than those previously reported for pediatric patients with T-ALL, the long-term failure-free rate remains low for patients presenting with greater than 50,000/microliter WBC.  相似文献   
26.
Fifty-two of 175 (30%) survivors of allogeneic marrow transplantation developed chronic graft-versus-hose diseases (GVHD). Five with limited chronic GVHD had an indolent clinical course with involvement of only the skin and liver. Forty-seven with extensive chronic GVHD had an unfavorable multiorgan disorder that resembled several autoimmune diseases. Thirteen patients with extensive disease (group I) were not treated and only 2 survive with Karnofsky scores >- 70%. Mortality resulted from infections and morbidity from sica syndrome, pulmonary and hepatic insufficiency, scleroderma-like skin disease, and contractures. Another 13 (group II) received a median of 8 mo prednisone and/or a brief course of antithymocyte globulin, and 3 survive without disability. The other 21 (group III) were treated with a combination of prednisone (1.0 mg/kg/q.o.d.) and either cyclophosphamide, procarbazine, or azathioprine (all 1.5 mg/kg/day) for a median of 13 mo. Combination therapy was well tolerated with only modest myelotoxicity. Fifteen in group III had a good and 4 a fair response to treatment while 2 with no response died. Azathioprine and prednisone was the most effective regimen. All therapy has been discontinued in 12 group III patients: GVHD returned in 5 (including 2 who died in spite of retreatment) while 7 remain free of GVHD for a median of 11 (range 6-30) mo observation. Only I group III survivor is disabled and 16 of the original 21 are alive 2-4 yr after transplant with Karnofsky scores of 70%-100%. Thus, combination immmunosuppression appears to favorably affect and, in some cases, premanently arrest the adverse natural course of extensive chronic GVHD.  相似文献   
27.
Faguet  GB; Agee  JF 《Blood》1988,72(2):679-684
The clinical usefulness of monoclonal antibodies (MoAbs) against the cCLLa, an antigen restricted to B-chronic lymphatic leukemia (CLL) and its variants, was ascertained in 65 patients with overt CLL and 25 individuals with unexplained mild lymphocytosis. Healthy volunteers (n = 25) and patients with malignant and nonmalignant disorders (n = 58) served as controls. The following observations were made in CLL. (a) Anti-cCLLa MoAbs identified neoplastic CLL cells as judged by the high correlation (r = .985) between monoclonal surface immunoglobulins (Slgs) and cCLLa expression in all patients, and dual-label flow cytometry studies showing cCLLa expression by monoclonal Slg-bearing B- CLL cells but not by normal B lymphocytes. (b) The size of the circulating cCLLa-positive clone paralleled the degree of lymphocytosis (r = .987) and was associated with reciprocal (r = .893) relative T lymphopenia. Ten patients with borderline lymphocytosis exhibited a subset of monoclonal Slg/cCLLa-positive cells ranging from 16% to 45% of the total. These patients were indistinguishable from those with CLL in terms of age, clone lineage, and reciprocal relative T lymphopenia. Two patients have progressed to overt CLL within 19 months, but eight have not (observation time, 18 to 82 months). These data suggest that anti-cCLLa MoAbs are sensitive probes useful to identify and monitor cCLLa clones during their clinical and preclinical phases.  相似文献   
28.
Addition of prostaglandins of the E series (PGE1, PGE2) in methylcellulose cultures of murine marrow results in a dose-dependent inhibition of the cloning efficiency of both BFU-E and CFU-C. However, CFU-E growth is unaffected. The inhibitory action of PGE is progressively overcome by increasing amounts of colony-stimulating factor (CSF), and with some limitations, also of erythropoietin (Ep). Addition of PGF2 alpha' associated or not with indomethacin, does not exert any significant effect on these hemopoietic precursors. In an attempt to unvail the mechanism(s) underlying these phenomena, dibutyryl-cyclic AMP (db-cAMP), theophylline (an inhibitor of phosphodiesterase), or theophylline + PGE were plated at various concentrations. Both db-cAMP and theophylline induce an inhibitory influence on both BFU-E and CFU-C growth, which mimicks that by PGEs; additionally, theophylline potentiates the inhibitory action of PGE1. In all these studies, the CFU-E number was not significantly modified. PGE action on BFU-E proliferation is clearly species-dependent, since PGE1 addition to human marrow methylcellulose cultures induces a significant enhancement of the number of both BFU-E and CFU-E derived colonies. This action was abolished upon removal of adherent cells, thus suggesting that PGE1 evokes a release of factor(s) enhancing human erythroid colony growth by adherent cells.  相似文献   
29.
Benis  KA; Schneider  GB 《Blood》1996,88(8):2898-2905
Osteopetrosis is a heterogeneous group of bone disorders characterized by the failure of osteoclasts to resorb bone and by several immunological defects including macrophage dysfunction. Two compounds, colony-stimulating factor-1 (CSF-1) and vitamin D-binding protein- macrophage activating factor (DBP-MAF) were used in the present study to evaluate their effects on the peritoneal population of cells and on cells within the bone marrow microenvironment in normal and incisors absent (ia) osteopetrotic rats. Previous studies in this laboratory have demonstrated that administration of DBP-MAF to newborn ia animals results in a substantial increase in bone marrow cavity size due to upregulated osteoclast function. To study the effects of these compounds on the macrophage/osteoclast precursors, DBP-MAF, CSF-1, and the combination of these compounds were given to newborn ia and normal littermate animals. Both the normal and mutant phenotypes responded similarly when treated with these compounds. Rats exhibited a profound shift toward the macrophage lineage from the neutrophil lineage when compared with vehicle-treated control animals after treatment with these compounds. In the in vivo peritoneal lavage study, animals received injections of CSF-1, DBP-MAF or DBP-MAF/CSF-1 over a 4-week period. The various types of cells in the peritoneal cavity were then enumerated. The in vitro study consisted of cells isolated from the bone marrow microenvironment and cultured on feeder layers of CSF-1, DBP-MAF, or DBP-MAF/CSF-1 for colony enumeration. The increase in macrophage numbers at the expense of neutrophil numbers could be seen in both the in vivo and in vitro experiments. The macrophage/osteoclast and neutrophil lineages have a common precursor, the granulocyte/macrophage colony-forming cell (GM-CFC). With the addition of CSF-1, the GM-CFC precursor may be induced into the macrophage/osteoclast lineage rather than the granulocyte lineage. This increased pool of cells in the macrophage/osteoclast lineage can be functionally upregulated with the subsequent addition of DBP-MAF to perform the activities of phagocytosis and bone resorption. The in vitro data also showed that DBP-MAF did not support colony development as in CSF-1 or the combination treatment. The recruitment and activation of cells into the macrophage/ osteoclast lineage may help to correct the bone and immune defects found in diseases demonstrating a significant lack of myeloid cells, as well as neutrophilia disorders and the disease, osteopetrosis.  相似文献   
30.
Schafer  AI; Zavoico  GB; Loscalzo  J; Maas  AK 《Blood》1987,69(5):1504-1507
Endothelial cell prostacyclin (PGI2) inhibits platelet activation by raising platelet cyclic AMP. Previously, platelet activation was also shown to be blocked by plasmin formed by endothelium-derived tissue plasminogen activator (TPA). We have now studied interactions between PGI2 and plasmin in the control of platelet function. PGI2 and plasmin cause synergistic inhibition of thrombin- and ADP-induced aggregation of washed platelets. Inhibition by PGI2 is similarly potentiated by TPA added to platelet-rich plasma to generate plasmin. Thrombin-stimulated rise in platelet cytosolic Ca2+, measured by fura2 fluorescence, and thromboxane A2 formation, measured by radioimmunoassay (RIA), are likewise synergistically inhibited by PGI2 and plasmin. Plasmin neither increases nor potentiates PGI2-stimulated increases in platelet cyclic AMP. Thus, PGI2 and plasmin cause synergistic inhibition of platelet activation by both cyclic AMP-dependent and independent mechanisms. This interaction between two different endothelium-derived products may play an important role in localizing the hemostatic plug to a site of vascular injury by preventing further thrombin-mediated accrual of platelets.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号