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   1549篇
  免费   149篇
  国内免费   7篇
耳鼻咽喉   5篇
儿科学   28篇
妇产科学   10篇
基础医学   157篇
口腔科学   17篇
临床医学   268篇
内科学   529篇
皮肤病学   4篇
神经病学   70篇
特种医学   251篇
外科学   110篇
综合类   22篇
预防医学   123篇
眼科学   6篇
药学   54篇
肿瘤学   51篇
  2023年   13篇
  2021年   18篇
  2020年   18篇
  2019年   14篇
  2018年   42篇
  2017年   22篇
  2016年   27篇
  2015年   26篇
  2014年   60篇
  2013年   68篇
  2012年   45篇
  2011年   62篇
  2010年   63篇
  2009年   83篇
  2008年   99篇
  2007年   87篇
  2006年   78篇
  2005年   84篇
  2004年   62篇
  2003年   51篇
  2002年   36篇
  2001年   38篇
  2000年   46篇
  1999年   36篇
  1998年   31篇
  1997年   33篇
  1996年   24篇
  1995年   22篇
  1994年   13篇
  1993年   22篇
  1992年   32篇
  1991年   19篇
  1990年   22篇
  1989年   41篇
  1988年   34篇
  1987年   34篇
  1986年   29篇
  1985年   22篇
  1984年   13篇
  1983年   13篇
  1982年   13篇
  1981年   12篇
  1980年   15篇
  1979年   10篇
  1978年   11篇
  1977年   16篇
  1976年   12篇
  1975年   9篇
  1973年   3篇
  1968年   4篇
排序方式: 共有1705条查询结果,搜索用时 15 毫秒
61.
62.
Nausea and vomiting are common complaints in chronic alcoholics. Autonomic neuropathy and esophageal motor abnormalities are frequently observed in chronic alcoholics, but gastric emptying has not been studied in these patients. Gastric emptying of a solid meal was measured, using 99mTc-sulfur colloid cooked in a scrambled egg, in 10 male chronic alcoholics with upper gastrointestinal complaints of nausea and vomiting. All patients were adequately nourished, recently drinking, but just over withdrawal and free of clinical peripheral neuropathy. Gastric emptying in 10 alcoholics was similar to 5 normal controls (t 1/2 115 +/- 12 versus 107 +/- 8 min). These data suggest that upper gastrointestinal symptoms in chronic alcoholics are not related to gastric motor dysfunction.  相似文献   
63.
We evaluated the role of rituximab during remission induction chemotherapy in relapsed aggressive CD20+ non-Hodgkin lymphoma. Of 239 patients, 225 were evaluable for analysis. Randomized to DHAP (cisplatin-cytarabine-dexamethasone)-VIM (etoposide-ifosfamide-methotrexate)-DHAP (cisplatin-cytarabine-dexamethasone) chemotherapy with rituximab (R; R-DHAP arm) were 119 patients (113 evaluable) and to chemotherapy without rituximab (DHAP arm) 120 patients (112 evaluable). Patients in complete remission (CR) and partial remission (PR) after 2 chemotherapy courses were eligible for autologous stem-cell transplantation. After the second chemotherapy cycle, 75% of the patients in the R-DHAP arm had responsive disease (CR or PR) versus 54% in the DHAP arm (P=.01). With a median follow-up of 24 months, there was a significant difference in failure-free survival (FFS24; 50% vs 24% vs, P<.001), and progression free survival (PFS24; 52% vs 31% P<.002) in favor of the R-DHAP arm. Cox-regression analysis demonstrated a significant effect of rituximab treatment on FFS24 (HR 0.41, 95% confidence interval [CI] 0.29-0.57 versus 0.51, 95% CI 0.37-0.70) and overall-survival (OS24: HR 0.60 [0.41-0.89] vs 0.76 [0.52-1.10]) when adjusted for time since upfront treatment, age, World Health Organization performance status, and secondary age-adjusted international prognostic index. These results demonstrate improved FFS and PFS for relapsed aggressive B-cell NHL if rituximab is added to the re-induction chemotherapy regimen.  相似文献   
64.
Kay  NE; Perri  RT 《Blood》1989,73(4):1016-1019
B-chronic lymphocytic leukemia (CLL) patients frequently suffer from moderate to severe hypogammaglobulinemia. This complication is a serious cause of morbidity and mortality in this disorder. There is recent evidence that natural killer (NK) cells modulate B-cell immunoglobin (Ig) synthesis/secretion. The authors therefore evaluated the circulating NK cells from B-CLL patients on their ability to regulate mitogen-induced B-cell Ig synthesis. Blood, NK cells (CD16+, CD3-) from three B-CLL patients with hypogammaglobulinemia were able to clearly down-regulate the pokeweed mitogen (PWM)-induced-B-cell Ig secretion. In contrast, CD16+, CD3- cells from age-sex-matched controls or B-CLL patients with normal Ig were either nonregulatory or enhanced mitogen-induced B-cell Ig secretion. An alternative explanation for hypogammaglobulinemia in B-CLL patients is the immunomodulation of B- cell Ig production/secretion by CD16+, CD3- blood cells.  相似文献   
65.
Achieving a metabolic complete response (mCR) before high-dose chemotherapy (HDC) and autologous peripheral blood stem cell transplant (auto-PBSCT) predicts progression-free survival (PFS) in relapsed/refractory classical Hodgkin lymphoma (R/R cHL). We added brentuximab vedotin (BV) to DHAP (dexamethasone, high-dose cytarabine, cisplatin) to improve the mCR rate. In a phase I dose-escalation part of the study in 12 patients, we showed that BV-DHAP is feasible. This phase II study included 55 R/R cHL patients (23 primary refractory). Treatment consisted of three 21-day cycles of BV 1.8 mg/kg on day 1, and DHAP (dexamethasone 40 mg days 1-4, cisplatin 100 mg/m² day 1 and cytarabine 2x2 g/m² day 2). Patients with a metabolic partial response (mPR) or mCR proceeded to HDC/auto-PBSCT. Based on independent central [18F]fluorodeoxyglucose (FDG) - positron emission tomography (PET) - computed tomography (CT) scan review, 42 of 52 evaluable patients (81% [95%CI: 67-90]) achieved an mCR before HDC/auto-PBSCT, five had an mPR and five had progressive disease (3 were not evaluable). After HDC/auto-PBSCT, four patients with an mPR converted to an mCR. Two-year PFS was 74% [95%CI: 63-86] and overall survival 95% [95%CI: 90-100]. Toxicity was manageable and mainly consisted of grade 3/4 hematologic toxicity, fever, nephrotoxicity, ototoxicity (grade 1/2), and transiently elevated liver enzymes during BV-DHAP. Eighteen patients developed new onset peripheral neuropathy (maximum grade 1/2); all recovered. In conclusion, BV-DHAP is a very effective salvage regimen in R/R cHL patients, but patients should be monitored closely for toxicity. (clinicaltrials.gov identifier: NCT02280993).  相似文献   
66.
Rice  WG; Kinkade  JM Jr; Parmley  RT 《Blood》1986,68(2):541-555
Previous studies on the fractionation of human neutrophil granules have identified two major populations: myeloperoxidase (MPO)-containing azurophil, or primary, granules and MPO-deficient specific, or secondary, granules. Peripheral blood neutrophils from individual donors were lysed in sucrose-free media by either hypotonic shock or nitrogen cavitation. Using a novel two-gradient Percoll density centrifugation system, the granule-rich postnuclear supernatant was rapidly (ten minutes) and reproducibly resolved into 13 granule fractions (L1 through L8 and H1 through H5). Granule flotation and recentrifugation experiments on both continuous, self-generated and multiple-step gradients using individual and mixed isolated fractions demonstrated that the banding patterns were isopycnic and nonartifactual. Isolated granules were intact based on the findings that biochemical latency of several granule enzymes was greater than 95%, and thin-sectioned electron micrographs demonstrated intact granule profiles. Biochemical analyses of the granule marker proteins MPO, beta-glucuronidase, lysozyme, and lactoferrin indicated that a number of the fractions were related to the major azurophil and specific granule populations. Lactoferrin was found in ten of 13 fractions (L1 through L8, H1 to H2), whereas MPO was found in every fraction. Consistent with these biochemical data, all fractions exhibited varying degrees of heterogeneity based on ultrastructural morphology and cytochemistry, including diaminobenzidine (DAB) reactivity for peroxidase and periodate-thiocarbohydrazide-silver proteinate (PA-TCH-SP) staining for complex glycoconjugates. A variable but significant percentage (23% to 70%) of the granules in fractions L1 through L8 and H1 and H2 showed DAB reactivity, while about 90% of the granules in fractions H3 through H5 were peroxidase positive. These results demonstrated that DAB-reactive granules spanned the entire range of granule size and density. Ultrastructural PA-TCH-SP staining of isolated granule fractions revealed patterns similar to those of granules in intact neutrophils at different stages of development. Granules from human acute promyelocytic leukemia cells (HL-60) exhibited a surprisingly low density compared with typical azurophil granules from normal, mature neutrophils. The data suggest that both functional and maturational differences contribute to granule heterogeneity, and provide a new practical and conceptual framework for further defining the phenomenon of neutrophil granule heterogeneity.  相似文献   
67.
68.
69.
70.
Professionalism is a broad competency needed by dentists to act effectively and efficiently and is seen as a central part of both undergraduate and postgraduate curricula. Assessment is vital in education to assess progress and direct future learning. It is also an essential part of good professional regulation, which depends upon high quality assessment to maintain credibility. Educators must produce clear expectations that students can strive for. Thus dental educators are required to understand precisely what is meant by “professionalism” in relation to dentistry in order to both teach and assess it. The aim of this paper is to explain the importance of professionalism, explore its features and its assessment as described in the literature. The paper concludes that without a validated definition of this construct, assessment of professionalism within dental education will be compromised.  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