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   1359篇
  免费   58篇
  国内免费   81篇
耳鼻咽喉   1篇
儿科学   67篇
妇产科学   13篇
基础医学   153篇
口腔科学   23篇
临床医学   233篇
内科学   317篇
皮肤病学   33篇
神经病学   28篇
特种医学   300篇
外科学   83篇
综合类   26篇
预防医学   32篇
眼科学   7篇
药学   74篇
肿瘤学   108篇
  2023年   2篇
  2022年   5篇
  2021年   8篇
  2019年   12篇
  2018年   8篇
  2017年   10篇
  2016年   11篇
  2015年   19篇
  2014年   14篇
  2013年   31篇
  2012年   17篇
  2011年   23篇
  2010年   51篇
  2009年   50篇
  2008年   24篇
  2007年   60篇
  2006年   19篇
  2005年   27篇
  2004年   14篇
  2003年   17篇
  2002年   22篇
  2001年   24篇
  2000年   30篇
  1999年   32篇
  1998年   96篇
  1997年   91篇
  1996年   111篇
  1995年   86篇
  1994年   87篇
  1993年   75篇
  1992年   25篇
  1991年   31篇
  1990年   30篇
  1989年   36篇
  1988年   40篇
  1987年   30篇
  1986年   36篇
  1985年   36篇
  1984年   15篇
  1983年   25篇
  1982年   20篇
  1981年   23篇
  1980年   17篇
  1979年   6篇
  1978年   11篇
  1977年   14篇
  1976年   13篇
  1975年   7篇
  1969年   1篇
  1966年   1篇
排序方式: 共有1498条查询结果,搜索用时 93 毫秒
61.
We examined 91 specimens (from 87 patients) for the expression of B- cell- and T-cell-associated differentiation antigens and rearrangements of the Ig and beta-chain of the T-cell (beta-TCR) genes. Of these, 74 were representative of various histologic subtypes of non-Hodgkin's lymphoma and related disorders, 11 of Hodgkin's disease, and 6 of reactive lymphoid hyperplasia. An Ig gene clonal rearrangement correlated to a monotypic (kappa/lambda) phenotype in 32 of 33 histologically defined lymphoma samples. The genotypic analysis also confirmed clonality in six of seven malignant diffuse lymphomas that were nonmonotypic but expressed pan-B antigens; in four, more than one clone was detected within individual tumors. A beta-TCR clonal rearrangement was found in 19 of 19 tumor samples considered as malignant T-cell lymphoma on the basis of histopathology and of the CD3- positive phenotype of tumoral cells, and in two cases of CD3-positive lymphomatoid disorders. A loss of pan-T antigens (CD7, CD5, CD2, CD4/CD8) was observed in all but three of these CD3-positive samples. Such an incomplete T-cell phenotype always correlated to the presence of a monoclonal process as revealed by genotypic analysis. DNA analysis was the only way to demonstrate clonality in other samples with either a polymorphous (partial involvement, pseudolymphoma, angioimmunoblastic lymphodenopathy [AILD]) or an undifferentiated (large cell anaplastic) phenotype. It is concluded that although in the majority of cases immunophenotyping alone provides criteria adequate for the diagnosis of lymphoid malignancy, in some, particularly polymorphous or large cell anaplastic processes, genetic probe analysis was additionally discriminative.  相似文献   
62.
Five patients with optic neuropathy, four vascular and one demyelinating, are described who each complained of an unusual symptom. Bright flashes of light (phosphenes) occurred in the affected eyes and were evoked by sudden unexpected sounds. Movement of the eye alone did not reproduce the symptom. In all patients the phenomenon was sufficiently prominent to interfere with sleep and was the main complaint of one patient. An anticonvulsant (phenytoin) greatly reduced the frequency and intensity of the phosphene in one patient.  相似文献   
63.
Natural killer (NK)-like T cells are major histocompatibility complex- unrestricted cytotoxic T cells that are surface CD3-positive, express NK-cell antigens, and rearrange their T-cell receptor. Most neoplasms arising from this T-cell subpopulation have been a chronic lymphoproliferative disease referred to as T-large granular lymphocyte (LGL) leukemia. Only 10 NK-like T-cell lymphomas have been described in detail previously; this study presents the clinicopathologic features of six others and distinguishes these lymphomas from T-LGL leukemia. All patients presented with B-symptoms and often had marked hepatosplenomegaly without significant peripheral lymphadenopathy. Four of the six patients were immunosuppressed. All had CD3, CD8, CD56- positive tumors, presumably of hepatosplenic (n = 3), intestinal (n = 1), pulmonary (n = 1), or nodal (n = 1) origin. Three patients had lymphomatous bone marrow infiltrates, and four had peripheral blood involvement by neoplastic large lymphocytes, some of which had a blastic appearance or resembled virocytes. Azurophilic granules, ultrastructurally corresponding to cytoplasmic dense core and/or double density granules, were seen in all cases. T-cell clonality was shown in five tumors by Southern blot analysis, and three had abnormal karyotypes. Two untreated patients died 20 days after presentation, and three patients who received combination chemotherapy died within 5 months of presentation. One patient remains in complete remission 22 months after treatment. These findings suggest NK-like T-cell lymphomas are aggressive, are clinicopathologically distinct from T-LGL leukemia, and should be in the differential diagnosis of extranodal T-cell lymphoproliferations, including those in immunosuppressed patients. Furthermore, the LGL morphology, phenotype, and tissue distribution of some NK-like T-cell lymphomas suggest they arise from thymic- independent T cells of the hepatic sinusoids and intestinal mucosa.  相似文献   
64.
High-dose intravenous gammaglobulin (polyvalent immunoglobulin G) has been shown to be of benefit in some patients with immune thrombocytopenic purpura (ITP), possibly by producing reticuloendothelial system blockade. We studied this approach in patients refractory to random donor platelet transfusion using an IV IgG preparation manufactured by the Swiss Red Cross. Eleven adult patients with acute leukemia received either 0.4 g IgG/kg/d intravenously X five days (four patients) or 0.6 g/kg/d X five days (seven patients). All patients had high levels of lymphocytotoxic antibody and poor responses to random donor platelets. Except for mild headaches in two patients, there were no side effects related to the IgG infusions. All patients had significant elevations of serum IgG on the day after completion of treatment. Either random donor or partially HLA-matched platelet transfusions were administered the day after and, in some cases, during the IgG therapy. No patient had an improvement in one hour posttransfusion platelet count increments. Two additional patients received pooled platelet concentrates incubated for 30 minutes at 37 degrees C with IgG at a final concentration of 3 g% prior to transfusions. These results indicate that high-dose IgG, an extremely expensive treatment, cannot be recommended for alloimmunized adults with leukemia.  相似文献   
65.
To determine the transmissibility of human T-lymphotropic virus types I and II (HTLV-I and HTLV-II) via transfusion, persons who, from 1983 to 1989, received blood components donated by persons who subsequently tested anti-HTLV-I-positive were evaluated. It was found that 16 (30%) of 54 evaluable recipients of transfused cellular components became infected with one of the HTLVs: 8 had HTLV-I and 8 had HTLV-II. Forty percent of platelet recipients and 28 percent of red cell recipients acquired infection. The rate of transmission of HTLV-I and HTLV-II was significantly correlated with storage age of red cell units prior to transfusion: 47 percent for red cells stored < or = 14 days and 0 for red cells stored > 14 days (p < 0.01). Multiple confirmatory serologic tests performed in 46 anti-HTLV-I enzyme immunoassay-negative recipients revealed that HTLV infection could not be excluded in 3 recipients of blood components from HTLV-II-infected donors. Polymerase chain reaction established HTLV-II infection in one recipient, and the other two recipients could not be classified with respect to HTLV infection status. It appears that some HTLV-II-infected transfusion recipients will not be detected by existing HTLV-I antigen-based reagents. If it is deemed necessary to initiate or continue look-back programs to detect transfusion transmission of HTLV-II infection, it is suggested that the current testing algorithm be modified in selected cases.  相似文献   
66.
67.
In-vitro fertilization patients (n = 15) at risk of ovarian hyperstimulation syndrome (OHSS) (oestradiol > or =4500 pg/ml on the day of human chorionic gonadotrophin administration and 25 or more follicles of intermediate or large size) underwent aspiration of all follicles and cryopreservation of all fertilized oocytes at the pronuclear stage. Patients were monitored for up to 2 weeks post- retrieval. Subsequent transfer of cryopreserved-thawed embryos was performed in programmed cycles using exogenous oestrogen and progesterone for endometrial preparation. Two patients (13%) developed OHSS necessitating hospitalization and vaginal aspiration of ascitic fluid. Two other patients (13%) developed moderate OHSS requiring ascitic fluid vaginal aspiration in the office setting, with dramatic improvement of the condition. Subsequent transfer of cryopreserved- thawed embryos yielded a clinical pregnancy rate of 58% per transfer and ongoing or delivery rates of 42 and 67% per transfer and per patient respectively. By eliminating pregnancy potential with cryopreservation of all prezygotes and examining the pregnancy potential with subsequent cryopreserved-thawed transfers, it is concluded that OHSS is reduced, but not eliminated for patients at risk. Subsequent transfer of cryopreserved-thawed prezygotes in a programmed cycle with exogenous steroids yields an excellent pregnancy rate.   相似文献   
68.
In our initial immunochemical study of the red blood cell (RBC) membrane proteins targeted in 20 cases of warm-antibody autoimmune hemolytic anemia (AHA), RBC eluates of 6 patients mediated immunoprecipitation (IP) of both band 3 and glycophorin A (GPA). This dual IP pattern had previously been observed with murine monoclonal antibodies (MoAbs) against the high frequency blood group antigen, Wrb (Wright), suggesting that the Wrb epitope may depend on a band 3-GPA interaction. Earlier, anti-Wrb had been identified serologically as a prominent non-Rh specificity of AHA autoantibodies. In the present study, 6 autoantibody eluates immunoprecipitating band 3 and GPA from common Wr(b+) RBCs were retested, in parallel with murine anti-Wrb MoAbs, against very rare Wr(a+b-)En(a+)RBCs. One patient's autoantibodies were unreactive with the Wr(b-) RBCs by either IP or indirect antiglobulin test (IAT) and were judged to have "pure" anti- Wrb specificity. Two other patients' autoantibodies displayed both IP and serologic evidence for anti-Wrb as a major component in combination with one or more additional specificities. However, among 3 other patients whose autoantibodies coprecipitated band 3 and GPA, there was no reduction in IP or IAT reactivity with Wr(b-) RBCs in 2 and only slight reduction in the third. We conclude (1) that human anti-Wrb autoantibodies, like their murine monoclonal counterparts, coprecipitate band 3 and GPA from human RBCs; but (2) that not all antibodies with this IP behavior have anti-Wrb serologic specificity, as defined by this donor's Wr(b-) RBCs. The possibility of an additional (non-Wrb) RBC epitope dependent on a band 3-GPA interaction is raised.  相似文献   
69.
In recent years, multiple loci dispersed on the genome have been shown to be associated with coronary artery disease (CAD). We investigated whether these common genetic variants also hold value for CAD prediction in a large cohort of patients with familial hypercholesterolemia (FH). We genotyped a total of 41 single-nucleotide polymorphisms (SNPs) in 1701 FH patients, of whom 482 patients (28.3%) had at least one coronary event during an average follow up of 66 years. The association of each SNP with event-free survival time was calculated with a Cox proportional hazard model. In the cardiovascular disease risk factor adjusted analysis, the most significant SNP was rs1122608:G>T in the SMARCA4 gene near the LDL-receptor (LDLR) gene, with a hazard ratio for CAD risk of 0.74 (95% CI 0.49–0.99; P-value 0.021). However, none of the SNPs reached the Bonferroni threshold. Of all the known CAD loci analyzed, the SMARCA4 locus near the LDLR had the strongest negative association with CAD in this high-risk FH cohort. The effect is contrary to what was expected. None of the other loci showed association with CAD.  相似文献   
70.

Objective

Bilateral salpingo-oophorectomy (BSO) is the gold standard prophylactic surgery for BRCA1 or 2 mutation carriers. However, due to the resulting early menopause and fertility desires, young women are reluctant to undergo this procedure. In view of the recent literature on ovarian carcinogenesis, we wish to report a novel conceptual surgical procedure we called “radical fimbriectomy.” This procedure is aimed to protect this subset of high-risk women from high-grade serous pelvic carcinoma, while preserving their ovarian function.

Methods

Women with BRCA mutation, who were scheduled for BSO, were informed of the procedure approved by our local review board. Radical fimbriectomy consists of removing all the tube and the fimbrio-ovarian junction, step immediately followed in this developmental phase by completion oophorectomy. Four methods of partial ovarian transsection were prospectively compared: sharp division, stapler, bipolar division and harmonic scalpel. Surgical safety and pathological alterations were assessed. All specimens underwent extensive pathological evaluation using both SEE-FIM protocol and serial sections.

Results

Fourteen women were enrolled in the study. Sharp and EndoGIA® appeared to be the safest methods of ovarian resection providing the best specimen quality for pathological examination.

Conclusion

We believe this technique could be suggested to young mutation carriers reluctant to undergo BSO. This approach is preferable to no prophylactic surgery at all. However, until the safety and validity of this procedure is confirmed by a multi-institutional study, women who undergo radical fimbriectomy should continue to receive regular multimodal evaluation and be advised of the risks involved until they finally accept secondary castration.  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