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   3106篇
  免费   166篇
  国内免费   4篇
耳鼻咽喉   22篇
儿科学   163篇
妇产科学   121篇
基础医学   345篇
口腔科学   123篇
临床医学   338篇
内科学   545篇
皮肤病学   44篇
神经病学   260篇
特种医学   43篇
外科学   430篇
综合类   10篇
预防医学   337篇
眼科学   53篇
药学   245篇
中国医学   6篇
肿瘤学   191篇
  2023年   17篇
  2022年   15篇
  2021年   36篇
  2020年   33篇
  2019年   60篇
  2018年   58篇
  2017年   38篇
  2016年   62篇
  2015年   75篇
  2014年   93篇
  2013年   141篇
  2012年   200篇
  2011年   188篇
  2010年   129篇
  2009年   112篇
  2008年   188篇
  2007年   209篇
  2006年   195篇
  2005年   189篇
  2004年   165篇
  2003年   171篇
  2002年   137篇
  2001年   38篇
  2000年   42篇
  1999年   55篇
  1998年   37篇
  1997年   34篇
  1996年   40篇
  1995年   32篇
  1994年   28篇
  1993年   26篇
  1992年   22篇
  1991年   44篇
  1990年   22篇
  1989年   27篇
  1988年   24篇
  1987年   28篇
  1986年   35篇
  1985年   22篇
  1984年   13篇
  1983年   18篇
  1982年   10篇
  1981年   17篇
  1980年   11篇
  1979年   22篇
  1978年   12篇
  1977年   14篇
  1975年   11篇
  1970年   9篇
  1967年   10篇
排序方式: 共有3276条查询结果,搜索用时 546 毫秒
1.
2.
3.
OBJECTIVE: Analysis of the effects of a comprehensive focal spasticity program in adult patients. DESIGN: Retrospective study of an out-patient cohort. PATIENTS: One hundred patients were enrolled in the study (54 men and 46 women, mean age 41 years (SD 14). Cerebral palsy and stroke were equally common (80% in total). The remaining patients had miscellaneous diagnoses, including traumatic brain injury. METHODS: On average 230 units (SD 101) of botulinum toxin A Botox was given for 227 principal therapy targets chosen by the patient or the caregiver. One patient could have several targets for therapy. Administration of botulinum toxin was combined with 260 additional therapeutic interventions, most of which were forms of physical therapy. The effects were assessed after 6 weeks and compared with baseline functional abilities 1-2 weeks prior to therapy. RESULTS: Improvement was observed for 211 (93%) therapy targets, no change in 15 (7%), and impairment in 1, corresponding to an overall improvement in 90 patients (90%), 9 unchanged (9%) and worsening in 1. Spasticity assessment (Ashworth scale 0-4; 30 patients) showed a statistically significant improvement (median at baseline was 3 vs 2 after therapy, mean difference 1.2, p<0.001). CONCLUSION: Improvement was observed in >or=90% of patients and in their principal therapeutic targets in a cohort receiving their first focal spasticity treatment with botulinum toxin A and additional therapy. A strict strategy for patient selection and comprehensive management was followed.  相似文献   
4.
BACKGROUND: The aim of this study was to develop a method to correct the heart position between two oxygen 15-labeled water cardiac positron emission tomography (PET) image sets to be able to use the equivalent regions of interest for the quantification of the perfusion values in the same myocardial segments. METHODS AND RESULTS: Independent component analysis was applied to the dynamic image sets (simulated phantom and 6 rest-pharmacologic stress and 10 rest-rest image sets of healthy female volunteers) acquired at different time points to separate the cardiac structures (ventricles and myocardium). The separated component images from independent component analysis from the 2 studies of the same individual were aligned with a normalized mutual information-based registration method. The alignment parameters were applied to position the regions of interest in the floating image sets for calculation of the myocardial blood flow values. In the rest case the mean myocardial blood flow value was 0.76 +/- 0.12 mL x g(-1) x min(-1) for the manual method and 0.79 +/- 0.10 mL x g(-1) x min(-1) for the proposed method (by use of the right ventricle component in the alignment), and in the stress case these values were 3.39 +/- 0.70 mL x g(-1) x min(-1) and 4.01 +/- 0.71 mL x g(-1) x min(-1), respectively. No statistically significant difference was found between the methods. CONCLUSION: In the tests with the phantom and patient images the alignment of cardiac structures was shown to be successful. The alignment could be done without the use of information from the myocardial compartment.  相似文献   
5.
The influence of metabolic control (HbA1c), noradrenaline (NA) and insulin-like growth factors (IGF-I and IGF-II) on renal function and size was investigated in 11 insulin-dependent diabetes mellitus patients aged 11–17 years. Renal function was evaluated in terms of glomerular filtration rate (GFR) and effective renal plasma flow (ERPF). Renal size was determined as renal parenchymal volume (RPV) by ultrasonography. The patients' HbA1c values ranged from 8.2% to 12.9% (normal range 5.5–8.5%) and their GFR and ERPF were higher than normal. Their IGF-II values were higher, and NA and IGF-I levels were lower than those of healthy controls. Inverse correlations between NA and GFR (r=–0.66) and NA and ERPF (r=–0.63) were found. No correlation was found between serum IGF-I and renal functional parameters. The IGF-II values correlated with GFR and HbA1c (r=0.63,r=0.70 respectively). There were linear correlations between RPV and GFR, RPV and ERPF, HbA1c and GFR, and ERPF and RPV. Decreased NA concentrations and increased IGF-II values appear to be factors contributing to renal hyperfunction in these patients.  相似文献   
6.
G Oberholpez  C T Botha  I C du Preez 《SADJ》2005,60(10):451-454
There exists a constant need for a dental curing light that works reliably and conveniently in the general practitioner's office and can be used effectively for all the different curing procedures. Due to the need for improved physical properties of resin based composites (RBCs) and less stress at the marginal interface, light curing units (LCUs) experienced significant advances in the past years. The dental industry has focused on reducing the curing time by developing higher intensity curing lights and by altering the resin composition and photo-initiator concentration. As a result the dentist can now choose from a vast variety of curing lights, light intensities and curing methods. This article presents a review of the advances in light curing units and curing techniques, as well as the scientific principles that guided past developments and that will influence future advances.  相似文献   
7.
ABSTRACT:Background: In 1996 a new model of maternity care characterized by continuity of midwifery care from early pregnancy through the postpartum period was implemented for women attending Monash Medical Centre, a tertiary level obstetric service, in Melbourne, Australia. This study's purpose was to assess the impact of this model on women's views and experiences of care during the antenatal, intrapartum, and postpartum periods compared with views of women receiving standard maternity care. Methods: One thousand low‐ and high‐risk women who booked at the antenatal clinic and met the eligibility criteria were randomly allocated to continuity of midwifery care from a group of seven midwives in collaboration with medical staff, or to standard care from a variety of midwives and medical staff. Women's views of care were measured by means of a postal questionnaire at four months after the birth. Results: Team midwifery care was associated with increased satisfaction with antenatal, intrapartum, and some aspects of postpartum care. The differences were most obvious for antenatal care. Conclusions: Continuity of midwifery care is realistically achievable in a tertiary obstetric referral service and is associated with increased satisfaction. (BIRTH 30:1 March 2003)  相似文献   
8.
Ulla Waldenstrm 《分娩》2003,30(4):248-254
Abstract: Background: Studies of women's memory of labor and birth have generally concluded that women's recall is fairly accurate, but the findings are not unanimous. The aim of this study was to compare women's experiences of labor pain and overall experience of the birth at 2 months and 1 year after the delivery. Methods: A longitudinal cohort study of 2,428 women recruited in early pregnancy from all antenatal clinics in Sweden during 3 weeks evenly spread during 1999–2000 was conducted. In addition to a questionnaire in early pregnancy including background data, the women completed a questionnaire at 2 months and 1 year after the birth including the same 7‐point rating scale of pain intensity and the same question about overall experience of labor and birth. Results: Forty‐seven percent of the women made the same assessment of pain intensity, and 60 percent of childbirth overall, at 1 year as they did at 2 months after the birth. One year after the birth, 35 percent recalled pain as less severe, and 18 percent as more severe, and 24 percent said labor and birth overall was more negative, whereas 16 percent said it was more positive. Conclusion: This study showed great variation in women's memories of labor and birth, and conclusions by some other studies, often based on analyses of group data rather than on the responses of the individual participants were, to some extent, challenged. (BIRTH 30:4 December 2003)  相似文献   
9.
A retrospective comparison of pyeloureterostomy and external ureteroneocystostomy as methods of reconstructing the urinary tract in 128 renal transplants is presented. There was one urological complication in 52 pyeloureterostomies (1.9%) compared with 4 in the 76 ureteroneocystostomies (5.3%). 6/0 Polydioxanone (PDS) is preferred to Prolene for the anastomosis because of possible calculus formation on the latter. Wound sepsis is commoner in pyeloureterostomies undergoing concomitant nephrectomy, despite prophylactic antibiotics, though this is not statistically significant and the overall sepsis rate is higher for ureteroneocystostomy. Nephrectomy was avoided in 17 selected cases by simply ligating the recipient ureter where the pre-transplant urine output was low. Two of these patients developed hydronephrosis in the isolated kidney and required later nephrectomy.  相似文献   
10.
PURPOSE: Research in the field of brain injury rehabilitation has tended to regard return to work as a measure of outcome. Researchers have not paid particular attention to the experiences of people living with a brain injury. The aim of the phenomenological study reported here was to identify and describe what characterizes the meaning of work to those with acquired brain injury. METHODS: Ten participants of working age were interviewed about the meaning of work 1-5 years after being inflicted with a brain injury. Data were analyzed and interpreted using the Empirical Phenomenological Psychological method. RESULTS: The findings revealed a meaning structure consisting of four main characteristics. Work was no longer experienced as the primary event in life and the social dimension had become more important. The perceived competence and work identity were threatened after the injury. A common theme across all interviews was the struggle to return to a state of normality, and working was considered to be evidence of success. CONCLUSION: The findings described the altered meaning of work 1-5 years after brain injury. This knowledge should lead to an increased understanding among occupational therapists engaged in work rehabilitation after brain injury and can serve as a basis for individualized intervention strategies.  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