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   460篇
  免费   22篇
  国内免费   25篇
耳鼻咽喉   8篇
儿科学   28篇
妇产科学   21篇
基础医学   46篇
口腔科学   14篇
临床医学   56篇
内科学   106篇
皮肤病学   4篇
神经病学   13篇
特种医学   55篇
外科学   47篇
综合类   8篇
预防医学   17篇
眼科学   20篇
药学   46篇
肿瘤学   18篇
  2023年   2篇
  2022年   4篇
  2021年   11篇
  2020年   6篇
  2019年   4篇
  2018年   12篇
  2017年   5篇
  2016年   15篇
  2015年   16篇
  2014年   7篇
  2013年   29篇
  2012年   19篇
  2011年   17篇
  2010年   18篇
  2009年   15篇
  2008年   19篇
  2007年   29篇
  2006年   13篇
  2005年   16篇
  2004年   23篇
  2003年   11篇
  2002年   11篇
  2001年   4篇
  2000年   4篇
  1999年   8篇
  1998年   18篇
  1997年   14篇
  1996年   19篇
  1995年   18篇
  1994年   14篇
  1993年   22篇
  1992年   5篇
  1991年   7篇
  1990年   8篇
  1989年   10篇
  1988年   8篇
  1987年   3篇
  1986年   3篇
  1985年   8篇
  1984年   4篇
  1983年   4篇
  1982年   5篇
  1981年   5篇
  1980年   2篇
  1979年   4篇
  1978年   3篇
  1976年   2篇
  1975年   1篇
  1971年   1篇
  1965年   1篇
排序方式: 共有507条查询结果,搜索用时 392 毫秒
61.
The aim of the present prospective, randomized study was to investigate and compare the safety and efficacy of dexmedetomidine versus midazolam in providing sedation for gastroscopy. A total of 50 adult patients (25 patients receiving dexmedetomidine and 25 patients receiving midazolam), 18 to 60 years of age, and rated I and II on the American Society of Anesthesiologists physical status classification system were included. A brief questionnaire was used to collect demographic data; patients were asked to rate anxiety, satisfaction with care to date and expected discomfort on a visual analogue scale. The following parameters were measured continuously and recorded every minute: heart rate, mean arterial pressure, hemoglobin oxygen saturation and respiratory rate. The two groups were similar with regard to age, body mass index, sex, education, duration of endoscopy, and ethanol or tobacco use. After the procedure, full recovery time, mean arterial pressure, heart rate, respiratory rate and hemoglobin oxygen saturation levels were similar in both groups. Both groups also had low levels of perceived procedural gagging, discomfort and anxiety scores (P > 0.05), and high satisfaction levels (90.1+/-3.0 for dexmedetomidine versus 84.9+/-4.5 for midazolam; P > 0.05). Retching and endoscopist satisfaction were significantly different in patients receiving dexmedetomidine versus those receiving midazolam (88.8+/-6.5 versus 73.5+/-16.4, P < 0.05; and 20.6+/-4.4 versus 45.2+/-6.0; P < 0.001). In the midazolam group, the number of patients who had adverse effects was higher than the dexmedetomidine group (P < 0.05). As a result, dexmedetomidine performed as effectively and safely as midazolam when used as a sedative in upper gastroscopy; it was superior to midazolam with regard to retching, rate of side effects and endoscopist satisfaction. It was concluded that dexmedetomidine may be a good alternative to midazolam to sedate patients for upper endoscopy.  相似文献   
62.
63.
Abstract The objective of this study was to evaluate the utility of a polymerase chain reaction (PCR) assay in detecting Mycobacterium tuberculosis in bronchoalveolar lavage (BAL) specimens of patients suspected of having active pulmonary tuberculosis (TB) but who were sputum smear-negative. Patients undergoing investigation for suspected pulmonary TB at the University Hospital, Kuala Lumpur, and who were sputum smear-negative underwent fibreoptic bronchoscopy and BAL. One portion of each lavage specimen was submitted for smear examination for acid-fast bacilli and mycobacterial culture and the other portion assayed by PCR for the presence of a 562-base pair DNA segment belonging to the insertion sequence IS986, unique to the M. tuberculosis complex. As controls, lavage specimens from patients with other lung lesions were also similarly tested. The PCR assay gave a positivity rate of 80.9% (55 of 68) compared with 8.8% of smear examination and 7.4% of culture for detecting M. tuberculosis in BAL specimens. The assay was positive in two of 45 BAL specimens from 35 control subjects. The PCR assay was more sensitive than smear and culture in detecting M. tuberculosis in BAL specimens of patients with sputum smear-negative pulmonary TB.  相似文献   
64.

BACKGROUND:

Psychosocial stress can be the cause or the consequence of hypertension.

OBJECTIVE:

To study the association between hypertension and anxiety or depression in adults from Hong Kong, China.

SUBJECTS AND METHODS:

Patients with diagnosed hypertension (n=197) were recruited to complete the Hospital Anxiety and Depression Scale (HADS) questionnaire. The control group comprised 182 normotensive subjects recruited using random telephone numbers.

RESULTS:

The score in the anxiety subscale (HADS-A) of the HADS correlated with age (r= −0.23, P<0.001) and sex (r=0.11, P=0.042), and was found to be higher in women. The score in the depression subscale (HADS-D) correlated with age (r=0.17, P=0.003) and hypertension (r=0.12, P=0.039), but not with sex (r=0.02, P=0.68). When the control subjects were matched for sex and age with the subjects with hypertension, the mean HADS-A score was 5.51±0.41 in 113 hypertensive subjects and 4.38±0.39 in 113 normotensive subjects (P=0.047). The mean HADS-D score was 5.56±0.39 in the hypertensive and 4.76±0.32 in the normotensive subjects (P=0.11). Multiple regression analysis using data from both groups indicated that the HADS-A score was related to the HADS-D score (β=0.49, P<0.001), age (β= −0.25, P<0.001) and sex (β=0.12, P=0.01) (R2=0.28), whereas the HADS-D score was related to the HADS-A score (β=0.48, P<0.001), age (β=0.30, P<0.001), positive smoking status (β=0.13, P=0.004) and lack of exercise habit (β=0.12, P=0.008) (R2=0.31). Hypertension was related to waist circumference, history of parental hypertension and age (R2=0.38, P<0.001). Anxiety and depression scores were rejected as independent variables.

CONCLUSIONS:

Hypertension was associated with anxiety but not depression; however, age, history of parental hypertension and central obesity appeared to have a stronger association with hypertension in adults from Hong Kong.  相似文献   
65.
Object?ves. Pharmacological treatment of attention deficit hyperactivity disorder (ADHD) includes stimulant and non-stimulant medications. Our purpose in this study is to investigate efficacy, safety and tolerability of combined methylphenidate and atomoxetine pharmacotherapy. Methods. We included 12 patients of the 824 patients with ADHD using methylphenidate and atomoxetine combined therapy between the years 2010 and 2014. Kiddie-SADS, Turgay DSM-IV Based Child and Adolescent Behavior Disorders Screening and Rating Scale, Child Behavior Checklist, Clinic Global Impression Scale Severity and Impression (CGIS-S-I) scales were used. Results. Patients were between the ages of 7 and 17 years. Before combined pharmacotherapy the CGIS-S score mean was 5.08. Mean CGIS-S score after the combined pharmacotherapy was 3.08 (P = 0.03; –2,980). The most common side effects were irritability (n = 5, 41.6%), appetite reduction (n = 3, 25%), palpitations (n = 2, 16.7%), headache (n = 1, 8.3%). Conclus?ons. Nine of these 12 patients showed significant improvement in their symptoms, combined therapy enhanced the effectiveness of monotherapy.  相似文献   
66.
Sixty-year-old woman admitted with dyspnea and cough. Three weeks ago she underwent primary stenting for acute anterior myocardial infarction and recieved antiplatelet therapy (clopidogrel). Echocardiography and left ventriculography revealed left ventricular segmental dysfunction at anterolateral-apical region but no thrombus. On last admission, despite the clopidogrel therapy, echocardiography showed giant-partly mobil thrombus obliterated half of the left ventricle. Slow infusion of thrombolytic therapy was given and complete lysis occurred with uneventful course. Disclosure of such a rapidly evolving giant left ventricular thrombus in the clopidogrel non-responder is a rare clinical problem with potentially catastrophic consequences. Slow infusion of thrombolytic therapy may be effective and life saving.  相似文献   
67.
Tumor cells from eight adult patients with T-cell chronic malignancies were investigated with a series of monoclonal antibodies recognizing T- cell differentiation antigens. This series allowed definition of discrete subpopulations of mature T cells with functional specialization. All six patients with Sezary syndrome and one patient with T-chronic lymphocytic leukemia had cells with the same phenotype as normal helper/inducer T cells, whereas the other patient with T- chronic lymphocytic leukemia had cell with the same phenotype as normal cytotoxic/suppressor T cells. Some clinical manifestations observed in these patients may reflect retention of functional activities by their malignant cells.  相似文献   
68.
Oluwole  SF; Engelstad  K; James  T 《Blood》1993,81(6):1658-1665
UVB irradiation (700 J/m2) of bone marrow cells (UVB-BMC) before transplantation into lethally gamma-irradiated (10.5 Gy) allogeneic rats prevents graft-versus-host disease (GVHD) and induces a stable complete lymphohematopoietic chimerism. To better understand the underlying mechanism of the development of stable chimerism and induction of tolerance to donor organs in this model, we examined if the addition of T cells or dendritic cells (DC), as antigen presenting cells (APC), would restore the immunogenicity of UVB-BMC in in vitro mixed lymphocyte reaction (MLR) and induce in vivo bone marrow (BM) graft rejection. Whereas gamma-irradiated, unfractionated BMC induce allogeneic T cells to proliferate, UVB irradiation of BMC abolishes the stimulatory capacity of such cells in a primary MLR. Addition of purified T cells, CD4+ T cells, CD8+ T cells or B cells, respectively, failed to restore the capacity of UVB-BMC to stimulate allogeneic T- cell proliferation. In contrast, the addition of only a small number of splenic accessory cells or purified DC, which by themselves were relatively ineffective in stimulating T-cell proliferation, restored the accessory function and the allostimulatory capacity of UVB-BMC. To define the molecular defect induced by UVB irradiation, cytokines were added as costimulatory factors to primary MLRs and the results showed that the addition of interleukin (IL)-2 or IL-6 but not IL-1 or interferon gamma (IFN-gamma) restored the stimulatory capacity of UVB BMC. This finding suggests that UVB may alter the production, and/or utilization of IL-2 and IL-6 either at the membrane or cytoplasmic level. Parallel in vivo studies showed that addition of DC to UVB BM inoculum resulted in failure of BM engraftment, whereas addition of T cells led to development of fatal GVHD, thus suggesting that UVB modulation of accessory cells reduces graft immunogenicity and prevents BMT rejection, while modulation of T cells prevents GVHD. Our data provide evidence that UVB modulation of APC and mature T cells contained within BMC is potentially useful in preventing GVHD without endangering successful engraftment and may serve as a model for induction of adult chimerism and tolerance without the development of GVHD.  相似文献   
69.

Background  

Pneumocystis jiroveci pneumonia (PCP) is an important opportunistic infection among immunosuppressed patients, especially in those infected with human immunodeficiency virus (HIV). The clinical presentation of PCP in immunosuppressed patients have been well-reported in the literature. However, the clinical importance of PCP manifesting in the setting of an immunorestitution disease (IRD), defined as an acute symptomatic or paradoxical deterioration of a (presumably) preexisting infection, which is temporally related to the recovery of the immune system and is due to immunopathological damage associated with the reversal of immunosuppressive processes, has received relatively little attention until recently.  相似文献   
70.
Immunologic heterogeneity of diffuse large cell lymphoma   总被引:2,自引:0,他引:2  
The cellular lineage of 57 diffuse large-cell lymphomas (DLCLs) was determined using a panel of monoclonal antibodies directed against lineage-restricted and -associated T, B, and monocyte antigens. The majority (82%) were of B cell lineage as determined by the expression of sig and/or B1, with the remaining 16% being of T cell lineage and 2%, of monocyte-myeloid lineage. By the expression of other B cell- restricted and -associated antigens, two major and two minor subgroups could be identified. These subgroups expressed the following phenotypes: (1) B1+B4+sIG+B2- (51%); (2) B1+B4+sIg+B2+ (29%); (3) B1+B4+sIg-B2+ (10%); and (4) B1+B4-sIg+B2- (10)%. The morphology of transformed lymphocytes, the weak to absent expression of the early B cell antigens B2 and sIgD, and the absence of the late B cell differentiation antigens PCA-1 and PC-1 suggested that these tumors were the neoplastic counterparts of normal B cells at the mid-stages of differentiation. Further support for the notion that B-DLCLs correspond to transformed B lymphocytes was concluded from the observation that B cells could be identified in normal spleen that expressed the cell surface phenotype and morphological appearance of the majority of B- DLCLs.  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