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   420篇
  免费   28篇
  国内免费   1篇
儿科学   8篇
妇产科学   11篇
基础医学   43篇
口腔科学   18篇
临床医学   27篇
内科学   36篇
皮肤病学   3篇
神经病学   15篇
特种医学   16篇
外科学   242篇
综合类   3篇
预防医学   7篇
药学   9篇
肿瘤学   11篇
  2022年   5篇
  2021年   3篇
  2020年   1篇
  2019年   4篇
  2018年   12篇
  2017年   6篇
  2016年   11篇
  2015年   16篇
  2014年   22篇
  2013年   33篇
  2012年   35篇
  2011年   35篇
  2010年   33篇
  2009年   38篇
  2008年   30篇
  2007年   19篇
  2006年   22篇
  2005年   15篇
  2004年   12篇
  2003年   9篇
  2002年   10篇
  2001年   4篇
  2000年   5篇
  1999年   1篇
  1998年   4篇
  1997年   5篇
  1996年   8篇
  1995年   4篇
  1994年   6篇
  1993年   6篇
  1992年   6篇
  1991年   2篇
  1990年   1篇
  1989年   4篇
  1988年   1篇
  1987年   1篇
  1986年   1篇
  1985年   2篇
  1984年   4篇
  1983年   1篇
  1981年   1篇
  1980年   2篇
  1978年   2篇
  1977年   2篇
  1976年   1篇
  1971年   1篇
  1970年   1篇
  1969年   1篇
  1968年   1篇
排序方式: 共有449条查询结果,搜索用时 31 毫秒
1.
Circannual variation in lymphocyte subsets, revisited   总被引:2,自引:0,他引:2  
BACKGROUND: Circadian and circannual variations in lymphocyte subsets, especially CD8+ T-lymphocytes, have been reported. This study focuses on CD4+ T-lymphocyte seasonal variation over a 6-year 8-month period. STUDY DESIGN AND METHODS: Lymphocyte subsets were quantitated monthly for four healthy individuals from 1986 through 1992 as part of a flow cytometry quality-control program. RESULTS: In general, there were no significant seasonal changes in the total number of white cells or in total lymphocyte counts. The absolute numbers of CD4+ T-lymphocytes were lowest in summer when the CD8+ T-lymphocytes were highest. Mean CD4+ T-lymphocyte counts were 846, 967, 618, and 695 per microL for Subjects 1 through 4, respectively, in winter and 432, 670, 355, and 766 per microL, respectively, in summer. Two healthy subjects had CD4+ T-lymphocyte counts lower than 300 per microL on one or more occasions during the study period. In three of the four subjects, the percentage of B-lymphocytes in winter was almost double that in summer. In one of the four subjects, no circannual rhythm was observed in these lymphocyte subpopulations. CONCLUSION: The seasonal variation in CD4+ T- lymphocyte counts demonstrated in three healthy individuals over almost 7 years is again of interest in light of renewed consideration of using surrogate tests, such as CD4+ T-lymphocyte counts, to screen for AIDS- like diseases that may be in the blood supply.  相似文献   
2.
The family history in family practice: a questionnaire study   总被引:9,自引:7,他引:2  
Summerton  N; Garrood  PV 《Family practice》1997,14(4):285-288
OBJECTIVES: Our aims were to investigate family medical history taking in general practice, and to evaluate the value attached to the family medical history as an aid to decision making in general practice. METHOD: A postal questionnaire survey was conducted among all 291 GPs working within the Calderdale and Kirklees Health Authority area. Each questionnaire was followed by a reminder. The main outcome measures were answers to questions on routine and opportunistic family history taking and a question about transmitting knowledge about genetic risk to other members of the family. Questions were also posed about the value attached to the family medical history as an aid to decision making. RESULTS: A total of 193 GPs returned the questionnaire (response rate 66.3%). On registration, 94.3% of GPs indicated that enquiries were made about a family history of coronary heart disease. Breast and colorectal cancer were specifically asked about by 48.4% and 30.7% of GPs, respectively. One-fifth of respondents indicated that they asked a general question about family medical history. A little over one-quarter of respondents indicated that they made opportunistic enquiries about the family history or suggested that the patient should inform other members of the family about possible risks. In the scenarios highlighted in this study, the majority of respondents felt that the family medical history had value as an aid to decision making. This was particularly the case for checking a patient's cholesterol (92.1%) and for initiating referrals in younger patients with possible cancer-related symptoms (three-quarters of respondents). CONCLUSION: GPs value the family medical history as an aid to decision making. Unfortunately, apart from enquiries about coronary heart disease, routine or opportunistic family history taking is not occurring in practice. Mechanisms need to be sought to extract information from the family medical history so that it can be more effectively used by GPs.   相似文献   
3.
BACKGROUND: This study was carried out to evaluate whether bilateral orchidopexy represents a poor or good prognostic factor in azoospermic men undergoing testicular sperm extraction (TESE). METHODS: One hundred and seven presumed non-obstructive azoospermia (NOA) patients, according to conventional clinical parameters (volume of testis, FSH, clinical history) were submitted to testicular biopsy with TESE. Thirty men (28%) had a history of bilateral orchidopexy for cryptorchidism. RESULTS: Normal spermatogenesis or mild hypospermatogenesis was diagnosed in 12/30 ex-cryptorchid patients and in 7/77 presumed NOA patients (P = 0.0004). Conversely, pure Sertoli cell-only syndrome or complete maturation arrest was found in 10/30 ex-cryptorchid patients and in 48/77 presumed NOA patients (P = 0.0094). In 53/107 patients (49.5%), TESE allowed a positive sperm retrieval. At least one spermatozoon was observed in 22/30 ( approximately 73%) ex-cryptorchid patients and in 31/77 ( approximately 40%) presumed NOA patients (P = 0.0026). A large number of spermatozoa (equivalent to an obstructive pathology) were retrieved in 13/30 ex-cryptorchid and in 10/77 presumed NOA patients (P = 0.001). A history of bilateral orchidopexy in presumed NOA patients correlates positively for the chance of retrieving testicular spermatozoa (odds ratio 3.8; 95% confidence interval 1.41-10.21; P = 0.008). CONCLUSIONS: Although bilateral cryptorchidism is usually considered a testicular secretive dysfunction, TESE permits retrieval of a large number of spermatozoa in almost 40% of cases. Our data suggest the existence of congenital or acquired obstructive anomalies of the seminal ducts in azoospermic orchidopexed men.  相似文献   
4.
BACKGROUND: People's reactions to traumatic events are mediated by their subjective style of coping. This is of particular importance for HIV+ patients, mainly in the first phases of the disease. This work aimed at examining whether an 'acceptance' style of coping, as opposed to a 'mental disengagement' style, selectively influences the first stages of the processing of neutral, emotional and HIV-related information. METHOD: Two groups of 11 HIV+ asymptomatic subjects were chosen according to their coping strategies, acceptance or mental disengagement, as measured by Coping Orientations to the Problems Experienced (COPE). Twenty-two patients completed the Emotional Stroop Task and an incidental memory recognition task containing neutral, emotional and HIV-related stimuli. RESULTS: Analysis of reaction times (RTs) on the Emotional Stroop Task showed that HIV+ subjects have longer RTs for emotional and HIV-related than for neutral words. Instead, no effect was found as regards interaction with style of coping. CONCLUSION: Results confirmed a processing bias of emotional information, whereas Acceptance and Mental disengagement strategies, as measured by the COPE scales, did not appear to influence information processing.  相似文献   
5.
A total of 61 kidney allograft specimens (51 biopsies and 10 nephrectomies) from 44 patients were investigated. Transplant glomerulopathy (TGP) was found in 38 specimens. Electron microscopy disclosed peculiar intertubular capillary changes (ITCC) in 47 specimens (all those showing TGP and nine without TGP). They were characterized by splitting and multilayering of the basement membranes. TGP and ITCC were graded and found mild (in 23 and 22 specimens), moderate (in 11 and 16 specimens), and severe (in four and nine specimens). Both worsened with time lapse from transplantation. When both were compared in single specimens, their grading was similar or, with a few exceptions, more severe for ITCC. TGP and ITCC were more frequent in biopsies with morphologic evidence of rejection and less frequent in patients treated with Cyclosporine A. Repeated biopsies and nephrectomies were studied in 10 patients and a somewhat more precocious appearance of ITCC than of TGP was found. Earlier and more severe ITCC were found in two patients who had had two transplants as compared to those with one. Morphologic similarities between TGP and ITCC suggest a common pathogenetic mechanism related to endothelial damage. The association to the histological evidence of rejection as well as the apparently protective activity of Cyclosporine A could support the involvement of an immune-mediated mechanism in agreement with what is reported in literature. The constant association of ITCC and TGP and its possible more precocious appearance enforce the diagnostic value of the former, which allows to infer the presence or the subsequent development of TGP even in biopsies where glomeruli are lacking.  相似文献   
6.
BackgroundWe aim to evaluate the impact of multiparametric magnetic resonance imaging and fusion-target biopsy for early reclassification of patients with low-risk Prostate Cancer in a randomized trial.Materials and methodsBetween 2015 and 2018, patients diagnosed with Prostate Cancer after random biopsy fulfilling PRIAS criteria were enrolled and centrally randomized (1:1 ratio) to study group or control group. Patients randomized to study group underwent multiparametric magnetic resonance imaging at 3 months from enrollment: patients with positive findings (PIRADS-v2>2) underwent fusion-target biopsy; patients with negative multiparametric magnetic resonance imaging or confirmed ISUP - Grade Group 1 at fusion-target biopsy were managed according to PRIAS schedule and 12-core random biopsy was performed at 12 months. Patients in control group underwent PRIAS protocol, including a confirmatory 12-core random biopsy at 12 months. Primary endpoint was a reduction of reclassification rate at 12-month random biopsy in study group at least 20% less than controls. Reclassification was defined as biopsy ISUP Grade Group 1 in >2 biopsy cores or disease upgrading.ResultsA total of 124 patients were randomized to study group (n = 62) or control group (n = 62). Around 21 of 62 patients (34%) in study group had a positive multiparametric magnetic resonance imaging, and underwent fusion-target biopsy, with 11 (17.7%) reclassifications. Considering the intention-to-treat population, reclassification rate at 12-month random biopsy was 6.5% for study group and 29% for control group, respectively (P < 0.001).ConclusionsThe early employment of multiparametric magnetic resonance imaging for active surveillance patients enrolled after random biopsy consents to significantly reduce reclassifications at 12-month random biopsy.  相似文献   
7.
Adjuvant chemotherapy and endocrine therapy can induce early iatrogenic menopause or worsen pre-existing menopausal symptoms in breast cancer survivors (BCS). The second most frequent menopausal symptom after hot flushes is the genitourinary syndrome (GSM). Since hormone replacement therapy is contraindicated in BCS, vaginal laser might represent a new nonhormonal option for GSM. This study aims at evaluating the effectiveness of the fractional CO₂ vaginal laser for GSM in BCS compared with healthy women. This is a retrospective study on 135 postmenopausal women (45 BCS and 90 healthy women) who underwent fractional CO2 laser for GSM. Objective (VHI and VVHI) and subjective outcomes (VAS for dyspareunia and vaginal dryness and a pain questionnaire) were evaluated at baseline visit and at every follow-up visit. Subjective and objective parameters improved significantly in both groups after laser therapy. The improvement was progressive and long-lasting up to 12 months after the end of the treatment. No severe adverse events were observed during the treatment. Fractional CO₂ vaginal laser induces a significant and long-lasting improvement on GSM symptoms in BCS. However, this improvement is slower than in healthy women undergoing the same treatment. Laser therapy turns out to be safe and well-tolerated.  相似文献   
8.
Extracorporeal CO2 removal (ECCO2R) primarily ensures CO2 removal, without significant effect on oxygenation. This is possible with low or moderate extracorporeal blood flows unlike ECMO devices. It is important to consider for each ECCO2R device not only the performance in terms of CO2 elimination but also the cost and safety, including the incidence of hemorrhagic and thrombotic complications. The most convincing clinical experience has been reported in the context of ARDS and severe acute exacerbations of COPD, particularly in patients at high risk of non invasive ventilation failure. Preliminary reported clinical benefits prompt to achieve in the short term randomized controlled trials in these two major indications.  相似文献   
9.
10.
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