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   393篇
  免费   34篇
  国内免费   4篇
儿科学   25篇
妇产科学   3篇
基础医学   28篇
口腔科学   8篇
临床医学   68篇
内科学   76篇
皮肤病学   9篇
神经病学   9篇
特种医学   82篇
外科学   31篇
综合类   6篇
预防医学   29篇
眼科学   3篇
药学   22篇
  2篇
肿瘤学   30篇
  2023年   4篇
  2022年   3篇
  2020年   4篇
  2019年   5篇
  2018年   9篇
  2017年   7篇
  2016年   6篇
  2015年   12篇
  2014年   12篇
  2013年   17篇
  2012年   16篇
  2011年   10篇
  2010年   15篇
  2009年   20篇
  2008年   11篇
  2007年   9篇
  2006年   9篇
  2005年   7篇
  2004年   9篇
  2003年   5篇
  2002年   8篇
  2001年   8篇
  2000年   3篇
  1999年   8篇
  1998年   18篇
  1997年   19篇
  1996年   16篇
  1995年   16篇
  1994年   15篇
  1993年   10篇
  1992年   5篇
  1991年   8篇
  1990年   9篇
  1989年   11篇
  1988年   4篇
  1987年   9篇
  1986年   7篇
  1985年   8篇
  1984年   6篇
  1983年   8篇
  1982年   3篇
  1981年   2篇
  1980年   4篇
  1979年   6篇
  1978年   5篇
  1977年   4篇
  1976年   7篇
  1975年   4篇
  1968年   3篇
  1958年   2篇
排序方式: 共有431条查询结果,搜索用时 15 毫秒
421.
Stage I and II follicular non-Hodgkin's lymphoma (NHL) is clinically defined as a localized disease. To study the possibility that this disease is in fact disseminated, we used the sensitive polymerase chain reaction (PCR) method using translocation (14;18) as marker. Samples from 21 patients who were clinically diagnosed with stage I or II follicular NHL were analyzed for the presence of t(14;18)-positive cells using PCR. We analyzed (1) the diagnostic lymph node biopsy and (2) the peripheral blood or bone marrow samples from these patients. Translocation (14;18) cells were detected in the diagnostic lymph node biopsies of 12 patients. In 9 of these patients, t(14;18)-positive cells were detected in peripheral blood and/or bone marrow samples at diagnosis and/or after therapy. Thus, in 75% of the follicular NHL patients carrying the t(14;18) as a marker for lymphoma cells, t(14;18)- positive cells were detected in peripheral blood and bone marrow at diagnosis and after therapy. Our results show that t(14;18)-positive cells can be detected in the circulation of patients with stage I and II follicular NHL, indicating that, although diagnosed as localized, the disease is disseminated.  相似文献   
422.
We report the case of a 41-year-old patient with no history of abdominal symptoms who presented with an acute painful syndrome of the right flank and iliac fossa suggesting acute appendicitis. The diagnosis of panniculitis of the great omentum was suggested preoperatively by the particular aspect of omental fat observed by abdominal sonography and computed tomography. A subvoval omentum resection was performed and the outcome was uneventful.  相似文献   
423.
Stenberg  PE; Beckstead  JH; McEver  RP; Levin  J 《Blood》1986,68(3):696-702
Using an immunoperoxidase technique that permits optimal antigen localization at the light microscope level, we have detected two platelet alpha-granule constituents and three platelet membrane glycoproteins in mouse bone marrow megakaryocytes and in murine megakaryocyte colonies grown in soft agar culture for three to seven days. Using polyclonal antibodies prepared against human platelet proteins, we have demonstrated labeling for von Willebrand factor, fibrinogen, and the membrane glycoproteins IIIa and GMP-140 in both bone marrow megakaryocytes and megakaryocyte colonies after seven days of culture. Using monoclonal antibodies to membrane glycoproteins IIb and GMP-140, we have demonstrated label in mouse bone marrow megakaryocytes. Granulocyte and macrophage colonies were negative for each of these markers. Murine bone marrow megakaryocytes and megakaryocyte colonies demonstrated a similar enzyme histochemical pattern: weakly positive for alpha-naphthyl acetate esterase and negative for chloroacetate esterase. These data indicate that megakaryocytes grown in soft agar culture express many of the same glycoproteins as bone marrow megakaryocytes. Furthermore, the ability of antibodies directed against human platelet membrane glycoproteins to identify murine megakaryocyte glycoproteins indicates that these constituents have been highly conserved during evolution.  相似文献   
424.
Background: Several contrast media (CM) are used for diagnostic angiography and coronary percutaneous interventions. Catheter miniaturization allows performance of most diagnostic studies using 4–5 F catheters and interventions using 5–6 F catheters. As a result of catheter lumen downsizing and viscosity of CM, the operators are sometimes required to forcefully inject to produce adequate images. Methods and Results: The aim of the study is to perform a comparative rheology analysis between three different commonly used CM: iso‐osmolar, nonionic iodixanol, Visipaque®, (GE Healthcare); low‐osmolar, nonionic ioversol, Optiray®; and low‐osmolar, ionic ioxaglate, Hexabrix®, (Tyco Healthcare, US). The viscosity was experimentally assessed for temperature varying from 14 to 40°C. To reproduce clinical use, an experimental set‐up was used and the pressure developed to inject CM was evaluated at different temperatures and compared between the three CM. All three agents demonstrated a nonlinear inverse relationship between temperature and viscosity. At 14°C iodixanol showed a twofold increase in viscosity compared with ioversol and ioxaglate. At 40°C, the difference was reduced to 27%. At room temperature (20°C), the difference in pressure needed to inject CM was 10% between iodixanol and ioxaglate and 6% between iodixanol and ioversol. As the temperatures increased, the differences in pressure became less important, becoming negligible (1%) at 37°C. Conclusion: The viscosity of the iso‐osmolar nonionic contrast agent iodixanol showed a stronger dependence on temperature compared with ioversol and ioxaglate. The impact of differences in viscosity and pressure to inject between CM were minimized at 37°C. This emphasizes the importance of temperature control when using current low‐osmolar CM and iso‐osmolar CM with smaller sized catheters. © 2008 Wiley‐Liss, Inc.  相似文献   
425.
We interviewed 51 blood donors in four major US metropolitan areas subsequently found to have had antibodies to human T-cell lymphotropic virus (anti-HTLV) in late 1984-early 1985. Sixteen donors (31%) reported that they or a sexual contact had a history of blood transfusion. Twelve donors (24%) reported that they or a sexual contact used intravenous drugs. Ten donors (20%) were blacks born in the southeastern US. Four of the male donors (15%) reported homosexual contact. The most common characteristic was an association with Japan or the Caribbean basin (61%). These results show a broader variation of epidemiologic backgrounds than anticipated.  相似文献   
426.
427.
428.
Background: First-line treatment of epithelial ovarian cancer (EOC) consists of a combination of cytoreductive surgery and platinum-based chemotherapy. Recently, targeted therapies such as bevacizumab have been shown to improve oncologic outcomes in a subset of a high-risk population. The objective of this study is to evaluate the patterns of practice and outcomes of first-line systemic treatment of advanced EOC, focusing on the adoption of bevacizumab. Methods: A population cohort study was conducted using administrative data in Ontario, Canada. Patients diagnosed with advanced stage non-mucinous EOC between 2014 and 2018 were identified. Datasets were linked to obtaining information on first-line treatment including surgery, systemic therapy, providers of care, systemic therapy facilities, and acute care utilization (emergency department (ED) visits and hospitalizations) during systemic treatment. Multivariate logistic regression was used to determine factors associated with systemic therapy utilization. Results: Among 3726 patients with advanced EOC, 2838 (76%) received chemotherapy: 1316 (47%) received neoadjuvant chemotherapy, 1060 (37%) underwent primary cytoreductive surgery followed by chemotherapy, and 462 (16%) received chemotherapy only. The median age was 67 (range: 20–100). Most chemotherapies were prescribed by gynecologic oncologists (60%) and in level 1 academic cancer centres (58%). Only 54 patients (3.1%) received bevacizumab in the first-line setting after its approval in Ontario in 2016. Bevacizumab was more likely to be administered by medical oncologists compared to gynecologic oncologists (OR 3.95, 95% CI 2.11–7.14). In total, 1561 (55%) and 1594 (56%) patients had at least one ED visit and/or hospitalization during systemic treatment, respectively. The most common reasons for ED visits were fever and bowel obstruction. Conclusion: Patterns of care for EOC in Ontario differed between care providers. The uptake of bevacizumab for first-line treatment of EOC was low. Acute care utilization related to EOC was high.  相似文献   
429.
Congenital left atrial appendage ostial stenosis is a very rare congenital cardiac condition. We present the case of an extremely premature infant with congenital left atrial appendage ostial stenosis diagnosed by transthoracic echocardiographic imaging.  相似文献   
430.
A recent medication error at Vanderbilt University Medical Center contributed to the death of a patient. The ensuing criminal indictment of the administering nurse has shaken the medical community. This has led to clinical staff questioning whether they can disclose patient safety incidents without fear of criminal prosecution. However, because of the publicity of this case, hospitals can benefit from the lessons learned and mitigate the risk of this and similar events at their facilities. To uncover the most impactful and relevant safety recommendations, the Vanderbilt case is examined from a systems investigation perspective using the available public information gathered from media reports, the Tennessee Bureau of Investigation report, and Vanderbilt's corrective action plan submitted to CMS. We present an example of how hospitals can benefit from disclosure: Henry Ford Health used the Vanderbilt case study as part of its medication safety continuous improvement initiatives, which are underpinned by available medication safety recommendations from the Institute for Safe Medication Practices. Using this experience and the lessons learned from the Vanderbilt case, a proactive action plan is presented for hospitals nationwide to prevent the recurrence of this medication error. Without disclosure, these analyses and safety recommendations would not have been possible.  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