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   1958篇
  免费   121篇
  国内免费   31篇
耳鼻咽喉   3篇
儿科学   149篇
妇产科学   25篇
基础医学   176篇
口腔科学   69篇
临床医学   218篇
内科学   504篇
皮肤病学   41篇
神经病学   50篇
特种医学   336篇
外科学   132篇
综合类   25篇
预防医学   105篇
眼科学   26篇
药学   128篇
  1篇
中国医学   2篇
肿瘤学   120篇
  2022年   8篇
  2021年   23篇
  2020年   22篇
  2019年   21篇
  2018年   28篇
  2017年   30篇
  2016年   30篇
  2015年   38篇
  2014年   44篇
  2013年   82篇
  2012年   45篇
  2011年   40篇
  2010年   72篇
  2009年   101篇
  2008年   46篇
  2007年   59篇
  2006年   50篇
  2005年   61篇
  2004年   45篇
  2003年   42篇
  2002年   38篇
  2001年   29篇
  2000年   37篇
  1999年   43篇
  1998年   103篇
  1997年   123篇
  1996年   113篇
  1995年   78篇
  1994年   83篇
  1993年   100篇
  1992年   24篇
  1991年   26篇
  1990年   27篇
  1989年   44篇
  1988年   39篇
  1987年   29篇
  1986年   37篇
  1985年   36篇
  1984年   17篇
  1983年   16篇
  1982年   19篇
  1981年   34篇
  1980年   23篇
  1979年   14篇
  1978年   9篇
  1977年   21篇
  1976年   19篇
  1975年   6篇
  1970年   5篇
  1966年   7篇
排序方式: 共有2110条查询结果,搜索用时 0 毫秒
81.

Objectives

The incremental costs of expanding antiretroviral (ARV) drug treatment to all HIV‐infected patients are substantial, so cost‐saving initiatives are important. Our objectives were to determine the acceptability and financial impact of de‐simplifying (i.e. switching) more expensive single‐tablet formulations (STFs) to less expensive generic‐based multi‐tablet components. We determined physician and patient perceptions and acceptance of STF de‐simplification within the context of a publicly funded ARV budget.

Methods

Programme costs were calculated for patients on ARVs followed at the Southern Alberta Clinic, Canada during 2016 (Cdn$). We focused on patients receiving Triumeq® and determined the savings if patients de‐simplified to eligible generic co‐formulations. We surveyed all prescribing physicians and a convenience sample of patients taking Triumeq® to see if, for budgetary purposes, they felt that de‐simplification would be acceptable.

Results

Of 1780 patients receiving ARVs, 62% (= 1038) were on STF; 58% (= 607) of patients on STF were on Triumeq®. The total annual cost of ARVs was $26 222 760. The cost for Triumeq® was $8 292 600. If every patient on Triumeq® switched to generic abacavir/lamivudine and Tivicay® (dolutegravir), total costs would decrease by $4 325 040. All physicians (= 13) felt that de‐simplifying could be safely achieved. Forty‐eight per cent of 221 patients surveyed were agreeable to de‐simplifying for altruistic reasons, 27% said no, and 25% said maybe.

Conclusions

De‐simplifying Triumeq® generates large cost savings. Additional savings could be achieved by de‐simplifying other STFs. Both physicians and patients agreed that selective de‐simplification was acceptable; however, it may not be acceptable to every patient. Monitoring the medical and cost impacts of de‐simplification strategies seems warranted.
  相似文献   
82.
Petzer  AL; Eaves  CJ; Lansdorp  PM; Ponchio  L; Barnett  MJ; Eaves  AC 《Blood》1996,88(6):2162-2171
Elevated numbers of primitive Philadelphia chromosome-positive (Ph+) progenitors, including long-term culture-initiating cells (LTC-IC) as well as colony-forming cells (CFC), have been previously described in the blood of patients with chronic myeloid leukemia (CML) in chronic phase with high white blood cell counts. In the present study, which focused primarily on an analysis of circulating progenitors present in such patients at diagnosis, we discovered the frequent and occasionally exclusive presence of circulating normal (Ph-) LTC-IC, often at levels above those seen for LTC-IC in the blood of normal individuals. The presence of detectable numbers of circulating Ph- LTC-IC was independent of the fact that the same peripheral blood samples also contained elevated numbers of predominantly or exclusively Ph+ CFC. Interestingly, both the Ph+ and Ph- LTC-IC in these samples were CD34+CD71- and variably CD38- and Thy-1+, as previously documented for LTC-IC in normal marrow. Thus, neither CD38 nor Thy-1 expression was useful for discriminating between Ph+ and Ph- LTC-IC in mixed populations. Nevertheless, an association of these phenotypes with LTC- IC function did allow highly enriched (> 5% pure) suspensions of either Ph+ or Ph- LTC-IC to be obtained from selected samples of CML blood in which the initial LTC-IC population was either predominantly Ph+ or Ph- , respectively. These findings suggest that the mechanisms causing mobilization of leukemic stem cells in untreated CML patients may affect their normal counterparts. They also indicate a possible new source of autologous cells for the support of intensive therapy of CML patients. Finally, they provide a method for obtaining the most highly purified populations of Ph+ LTC-IC described to date. This method should be useful for further analyses of the molecular activities of these very primitive neoplastic cells.  相似文献   
83.
Fludarabine was used to treat 68 patients with previously treated chronic lymphocytic leukemia (CLL). Nine (13%) patients achieved a complete remission and 30 (44%) a partial remission. The response rates for Rai stages 0 to 2, 3, and 4 were 64%, 58%, and 50% respectively. Seventeen (43%) of the 40 Rai stage 1 to 3 patients and four (19%) of the Rai stage 4 patients returned to Rai stage 0. Survival was strongly correlated with the final Rai stage achieved. The survival of the 11 partial responders with residual disease consisting only of residual bone-marrow nodules was similar to the complete responders (36+ months) and superior to the other partial response patients (16 months). The response to fludarabine was rapid, with 36 (92%) of the 39 responders having achieved at least a partial response following the first three courses. Complete responses occurred in the blood, liver, spleen, and lymph nodes in 48% to 69% of the patients. Eradication of all disease in the bone marrow occurred in only 13% of the cases. Neutropenia and thrombocytopenia occurred in 56% and 25% of evaluable courses. Major infections occurred in 9% of evaluable courses and fevers of unknown origin or minor infections in 12% of courses respectively. Myelosuppression and infection were more common in patients with initial Rai stages 3 and 4 and in nonresponding patients. Other toxicity was mild. No CNS toxicity was noted.  相似文献   
84.
85.
CM Giles  ; M Botto  ; MJ King 《Transfusion》1990,30(2):126-132
HLA class I antigens (Bg) on red cells (RBCs) are expressed by some normal donors and by many patients with systemic lupus erythematosus (SLE). To identify the membrane components previously detected by hemagglutination with HLA class I-specific monoclonal antibodies (MoAbs), RBC membrane preparations were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotted with the HLA class I MoAbs. Two components were obtained that reacted with the MoAbs: a heavy chain of 45 kDa and a light chain termed beta2-microglobulin (beta2-M) of 11 kDa. The effect of chloroquine and acid elution in stripping HLA antigens is shown to be due to the removal of beta2-M, as only that component was detected in eluates from reactive RBCs. Neither antibody elution method affected the heavy chain expression assessed by immunoblotting. It is concluded that HLA class I antigens on RBCs are integral membrane components of the type normally found and wisely distributed on many nucleated cells. Platelets, which have stronger HLA class I antigen expression, were also studied, and their membrane preparations yielded heavy chain and beta2-M molecules; the effect of chloroquine treatment was harder to assess than that of acid elution, owing to the sensitivity with which both components are detected in immunoblotting. In eluates obtained from acid treatment only beta2-M is detected.  相似文献   
86.
WHO生存质量评估简表的等价性评价   总被引:20,自引:0,他引:20  
目的评价WHO生存质量评估简表(WHOQOL-BREF)在13个国家的等价性。方法采用多组验证性因子分析方法,对世界卫生组织生存质量研究小组提供的13个国家的数据进行分析,评价WHOQOL-BREF不同国家的等价性。结果各个国家的各个领域的Cronbachα系数均大于0·7,分布在0·7至0·88之间。除了英国和挪威之外,其它国家的社会关系领域的Cronbachα系数均大于0·65。采用根据世界卫生组织生存质量研究小组研制量表时构建的四因子模型对数据分别进行拟合,拟合优度指数(CFI)均大于0·8,其中德国、西班牙和美国的拟合优度指数大于0·9。多组验证性因子分析发现模型拟合尚可,CFI等于0·88,各个国家的因子负荷不全相等,因子负荷的轮廓相似。结论WHOQOL-BREF在13个国家具有相同的因子结构,且有等价性。  相似文献   
87.
88.
89.
Locally deranged joint anatomy can predispose to septic arthritis which can be managed by surgical debridement. We present a case of manubriosternal subluxation/dislocation caused by kyphoscoliosis leading to manubriosternal septic arthritis.  相似文献   
90.
Information is integrated across the visual field to transform local features into a global percept. We now know that V1 neurons provide more spatial integration than originally thought due to the existence of their nonclassical inhibitory surrounds. To understand spatial integration in the visual cortex, we have studied the nature and extent of center and surround influences on neuronal response. We used drifting sinusoidal gratings in circular and annular apertures to estimate the sizes of the receptive field's excitatory center and suppressive surround. We used combinations of stimuli inside and outside the receptive field to explore the nature of the surround influence on the receptive field center as a function of the relative and absolute contrast of stimuli in the two regions. We conclude that the interaction is best explained as a divisive modulation of response gain by signals from the surround. We then develop a receptive field model based on the ratio of signals from Gaussian-shaped center and surround mechanisms. We show that this model can account well for the variations in receptive field size with contrast that we and others have observed and for variations in size with the state of contrast adaptation. The model achieves this success by simple variations in the relative gain of the two component mechanisms of the receptive field. This model thus offers a parsimonious explanation of a variety of phenomena involving changes in apparent receptive field size and accounts for these phenomena purely in terms of two receptive field mechanisms that do not themselves change in size. We used the extent of the center mechanism in our model as an indicator of the spatial extent of the central excitatory portion of the receptive field. We compared the extent of the center to measurements of horizontal connections within V1 and determined that horizontal intracortical connections are well matched in extent to the receptive field center mechanism. Input to the suppressive surround may come in part from feedback signals from higher areas.  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