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   620篇
  免费   38篇
耳鼻咽喉   7篇
儿科学   9篇
妇产科学   8篇
基础医学   64篇
口腔科学   25篇
临床医学   28篇
内科学   123篇
皮肤病学   8篇
神经病学   61篇
特种医学   13篇
外科学   79篇
综合类   19篇
预防医学   90篇
眼科学   19篇
药学   65篇
中国医学   8篇
肿瘤学   32篇
  2024年   1篇
  2023年   8篇
  2022年   4篇
  2021年   24篇
  2020年   19篇
  2019年   29篇
  2018年   26篇
  2017年   21篇
  2016年   26篇
  2015年   23篇
  2014年   35篇
  2013年   33篇
  2012年   70篇
  2011年   63篇
  2010年   32篇
  2009年   28篇
  2008年   39篇
  2007年   43篇
  2006年   38篇
  2005年   30篇
  2004年   23篇
  2003年   15篇
  2002年   9篇
  2001年   1篇
  2000年   4篇
  1999年   2篇
  1998年   2篇
  1995年   1篇
  1994年   1篇
  1993年   2篇
  1992年   1篇
  1989年   1篇
  1986年   2篇
  1975年   1篇
  1974年   1篇
排序方式: 共有658条查询结果,搜索用时 296 毫秒
81.
82.
Until now, cerebral venous sinus thrombosis (CVST) was principally an autopsy diagnosis; however, with the introduction of MRI and angiography, as well as enhanced clinical attentiveness, it is now reliably diagnosed during life. Herein, we describe a case of CVST accompanied by oligodendroglioma and pregnancy. In our patient, the following factors contributed to the formation of CVST: First, the pregnancy state, which is a known risk factor for developing venous thrombosis; and secondly, the oligodendroglioma could have changed the architecture of adjacent sinus (right lateral sinus) and provocation of the development of clot in the sinus.  相似文献   
83.
84.
BACKGROUND: The primary objective of this study was to measure the prevalence, incidence, and resolution of insulin resistance (IR) in critically ill patients. A secondary objective was to explore the relationship between IR and inflammatory cytokines, coagulation abnormalities, and clinical outcomes. Design: Prospective observational study. METHODS: The setting was the medical/surgical intensive care unit (ICU). We enrolled consecutive patients within 24 hours of admission to the ICU. Blood samples were collected daily until discharge, death, or a maximum of 10 days, then sent for measurement of markers of IR, inflammation, and coagulation. Charts were reviewed retrospectively to determine clinical outcomes. The homeostasis model assessment method (HOMA) was used to determine IR; a score of > or = 4 represents insulin resistance. RESULTS: A total of 96 patients were enrolled. Upon admission, 64 (67%) patients had overt IR (glucose > 7 mmol/L or insulin use), 9 (9.4%) had non-overt IR (normal glucose but HOMA > 4), and 23 (24%) were insulin sensitive (IS; normal glucose and HOMA < 4). During the course of ICU stay, an additional 16 patients developed overt IR, while 10 (10%) remained IS. There were no significant differences in inflammatory markers, coagulation tests, and clinical outcomes between IR and IS patients. There was no significant correlation between HOMA and inflammatory markers and coagulation markers. In a multivariable regression model, only interleukin-6 levels were significantly associated with mortality. CONCLUSIONS: A high proportion of critically ill patients have IR. There may not be any significant relationship between IR and measures of inflammation, coagulation, and clinical outcomes in a heterogeneous population of critically ill patients.  相似文献   
85.
A new dihydroflavonol, songaricol ( 1) and seven known flavonoids, ayamenin A ( 2), irisflavone A ( 3), 5,7-dihydroxy-2',6-dimethoxyisoflavone ( 4), irilin B ( 5), 5,3'-dihydroxy-7,8,2'-trimethoxyisoflavone ( 6) and irisoid A ( 7) were isolated from rhizome and roots of IRIS SONGARICA. Structure elucidation of 1 was achieved through extensive NMR and circular dichroism techniques. Compounds 1, 5 and 7 showed antioxidant activity in HL-60 cells (IC50 values of 21, 11 and 3.8 microg/mL), whereas 2, 5 and the previously isolated irisone B were able to show estrogenic response (EC50 values of 305.5, 159.7 and 322.0 microg/mL) in yeast cells expressing human estrogen receptor (ER-alpha).  相似文献   
86.
One-third of lithium-treated men complain from sexual dysfunction, although the exact mechanisms of which are not yet known. In this study we investigated the effect of chronic lithium (LiCl, 600 mg/l for 30 days) administration on the neurogenic relaxation of isolated rat corpus cavernosum. The corporal strips were precontracted with phenylephrine and electrical field stimulation (EFS) was applied to obtain relaxation. Relaxation to EFS was significantly (P<0.001) impaired in LiCl-treated rats. The nitric oxide (NO) synthase inhibitor Nomega-nitro-l-arginine methyl ester (l-NAME; 100 microM) inhibited the relaxation to EFS in both LiCl-treated and control rats. The NO precursor l-arginine, at per se noneffective concentration (0.1 mM), significantly (P<0.001) enhanced the EFS-induced relaxation of LiCl-treated corporal strips. The relaxation responses to the NO donor sodium nitroprusside were similar between two groups. These data demonstrate that chronic lithium treatment could impair the NO-mediated neurogenic relaxation of rat corpus cavernosum which could be prevented by l-arginine.  相似文献   
87.
Anti-CD20 antibodies radiolabeled with I-131 tositumomab (Bexxar) or Y-90-Ibritumomab tiuxetan (Zevalin), are similarly efficacious in treating chemotherapy-refractory non-Hodgkin's lymphoma. The relative merits of both radioimmunoconjugates with respect to practical issues, including radiation exposure risk, the advantages and disadvantages of the respective isotopes and other parameters that could affect a patient's quality of life are also important. I-131-labeled antibody treatment often requires inpatient hospitalization due to the inherent risk of exposure from gamma emissions, and patients and families should follow detailed instructions to prevent undue exposure. Other issues relevant to patients and medical staff include: (1) the need for dosimetry to calculate effective therapeutic doses of I-131-labeled anti-B1 (Bexxar) compared with the lack of correlation of dosimetry with marrow toxicity for IDEC-Y2B8 (Zevalin), (2) determining the acute and long-term toxic effects of each agent, (3) time commitments for nuclear medicine staff and patients along with the relative ease of administration, and (4) cost considerations. A more challenging future issue will be to determine the optimal use of Bexxar and Zevalin alone and in combination in ways that will significantly affect patient outcome without compromising quality of life. The recent demonstration of significant response rates in patients having chemotherapy-refractory Non-Hodgkin's Lymphoma (NHL) using both on I-131- and Y-90-labeled anti-CD20 antibodies with minimal toxicity has stimulated comparison of I-131 tositumomab (Bexxar) and Ibritumomab tiuxetan (Zevalin) in terms of radiation safety requirements, the advantages and disadvantages of both radionuclides, and quality-of-life (QOL) issues. Therefore, in this review, we attempt to compare the relative merits of (Bexxar and Zevalin) and address important practical considerations that may influence patient and physician choices regarding treatment using these agents.  相似文献   
88.
Population-based estimates of human immunodeficiency virus (HIV) prevalence and risk behaviors among men who have sex with men (MSM) are valuable for HIV prevention planning but not widely available, especially at the local level. We combined two population-based data sources to estimate prevalence of diagnosed HIV infection, HIV-associated risk-behaviors, and HIV testing patterns among sexually active MSM in New York City (NYC). HIV/AIDS surveillance data were used to determine the number of living males reporting a history of sex with men who had been diagnosed in NYC with HIV infection through 2002 (23% of HIV-infected males did not have HIV transmission risk information available). Sexual behavior data from a cross-sectional telephone survey were used to estimate the number of sexually active MSM in NYC in 2002. Prevalence of diagnosed HIV infection was estimated using the ratio of HIV-infected MSM to sexually active MSM. The estimated base prevalence of diagnosed HIV infection was 8.4% overall (95% confidence interval [CI] = 7.5–9.6). Diagnosed HIV prevalence was highest among MSM who were non-Hispanic black (12.6%, 95% CI = 9.8–17.6), aged 35–44 (12.6%, 95% CI = 10.4–15.9), or 45–54 years (13.1%, 95% CI = 10.2–18.3), and residents of Manhattan (17.7%, 95% CI = 14.5–22.8). Overall, 37% (95% CI = 32–43%) of MSM reported using a condom at last sex, and 34% (95% CI = 28–39%) reported being tested for HIV in the past year. Estimates derived through sensitivity analyses (assigning a range of HIV-infected males with no reported risk information as MSM) yielded higher diagnosed HIV prevalence estimates (11.0–13.2%). Accounting for additional undiagnosed HIV-infected MSM yielded even higher prevalence estimates. The high prevalence of diagnosed HIV among sexually active MSM in NYC is likely due to a combination of high incidence over the course of the epidemic and prolonged survival in the era of highly active antiretroviral therapy. Despite high HIV prevalence in this population, condom use and HIV testing are low. Combining complementary population-based data sources can provide critical HIV-related information to guide prevention efforts. Individual counseling and education interventions should focus on increasing condom use and encouraging safer sex practices among all sexually active MSM, particularly those groups with low levels of condom use and multiple sex partners At the time this work was conducted, Manning and Marx were with the Epidemic Intelligence Service, Office of Workforce and Career Development, Centers for Disease Control and Prevention, Atlanta, GA, USA; Thorpe, Ramaswamy, Hajat, Marx, Karpati, Mostashari, and Pfeiffer are with the New York City Department of Health and Mental Hygiene, New York, NY, USA; Nash is with the Department of Epidemiology and International Center for AIDS Care and Treatment Programs, Columbia Mailman School of Public Health, New York, NY, USA; Manning is with the Massachusetts Department of Public Health, Bureau of Family and Community Health, Boston, MA, USA.  相似文献   
89.
Today, health systems around the world are under pressure to create greater value for patients and society; increasing access, improving client orientation and responsiveness, reducing medical errors and safety, restraining utilization via managed care, and implementing priority allocation of resources for high-burden health problems are examples of strategies towards this end. The quality paradigm by virtue of its strategic consumer focus and its methods for achieving operational excellence has proved an effective approach for creating higher value in many sectors. If applied in a deliberate and holistic manner, the quality paradigm can bring about a more cost-effective organization of the health systems. In this article, we apply quality concepts to healthcare in a conceptual format; we characterize the health system's customers and outputs with their quality dimensions. The product of this effort is a blueprint for a customer-driven health system which identifies six types of customers, nine types of outputs and the associated operations. As a preliminary step, a new analysis and definition of health and disease is provided. Rethinking the structure of health system in this manner and the related conceptual model can guide medical research, health sciences education, and health services policy, and help the practitioner to integrate all modern trends in healthcare delivery.  相似文献   
90.
The purpose of the present study was twofold: (1) to investigate how many diabetic patients and types of cases that are treated with dental implants in our clinic; and (2) assess the outcome of such treatment. Medical records from 782 patients were examined in patients treated by the Br?nemark method for partial or total edentulism with implant supported bridges. From these records, 25 patients (3.2%) with diabetes before implant treatment (136 implants) were identified and further studied with respect to age, gender, type of diabetes, treated jaw, degree of edentulism, bone graft, implant survival, periimplant inflammation, bleeding on probing, and radiographic bone loss. Furthermore, the patients' opinion about the outcome of the treatment was registered. The implant success rate was 96.3% during the healing period and 94.1% 1 year after surgery. Of all 38 bridges, one was lost. Few complications occurred and all patients, except for one, were satisfied with the treatment. Today, diabetic patients are being treated successfully for all types of edentulism, including bone-grafting treatment. Diabetics that undergo dental implant treatment do not encounter a higher failure rate than the normal population, if the diabetics' plasma glucose level is normal or close to normal as assessed by personal interviews.  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