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   1504篇
  免费   119篇
  国内免费   6篇
耳鼻咽喉   15篇
儿科学   106篇
妇产科学   47篇
基础医学   153篇
口腔科学   50篇
临床医学   105篇
内科学   323篇
皮肤病学   25篇
神经病学   79篇
特种医学   39篇
外国民族医学   2篇
外科学   169篇
综合类   39篇
预防医学   243篇
眼科学   37篇
药学   128篇
中国医学   11篇
肿瘤学   58篇
  2023年   16篇
  2022年   37篇
  2021年   61篇
  2020年   28篇
  2019年   38篇
  2018年   61篇
  2017年   33篇
  2016年   54篇
  2015年   48篇
  2014年   64篇
  2013年   71篇
  2012年   96篇
  2011年   96篇
  2010年   58篇
  2009年   32篇
  2008年   73篇
  2007年   78篇
  2006年   84篇
  2005年   75篇
  2004年   92篇
  2003年   74篇
  2002年   63篇
  2001年   33篇
  2000年   33篇
  1999年   25篇
  1998年   16篇
  1997年   9篇
  1996年   4篇
  1995年   7篇
  1994年   12篇
  1993年   10篇
  1992年   15篇
  1991年   12篇
  1990年   13篇
  1989年   21篇
  1988年   16篇
  1987年   17篇
  1986年   14篇
  1985年   6篇
  1984年   9篇
  1983年   6篇
  1979年   2篇
  1975年   1篇
  1974年   4篇
  1972年   1篇
  1971年   2篇
  1969年   2篇
  1968年   1篇
  1967年   1篇
  1966年   2篇
排序方式: 共有1629条查询结果,搜索用时 215 毫秒
101.
The socio-demographic and biological processes contributing to infant mortality and undernourishment were studied in five urban squatter settlements of Karachi. All those families who had experienced an infant death in the past 2 years (N = 106) were recruited into the study. Comparative children were selected by random numbers with geographical matching from families with at least one live infant and without a history of infant deaths in the past 2 years. The comparison children were weighed and those found underweight (27 per cent) were studied for the presence of risk factors. Forty-one per cent of all deaths were in the neonatal period, and in 47 per cent of cases deaths had occurred in infants with a birth order of 5 and above. Age, duration of breast feeding, birth interval, and the live/dead status of the previous sibling were significant biological variables accounting for 23 per cent of the variance for survival. Socio-economic status accounted for 22 per cent of the variance and health-seeking behaviour (antenatal care, immunization, etc.) for 28 per cent. Sixty-eight per cent of those underweight were more than 6 months old. Age, female sex, birth interval less than 24 months, duration of breast feeding, adolescent mother, alive/dead status of the previous child were significant influences accounting for 12 per cent of the variance. Socio-economic status and health seeking behaviour were also important determinants, but not to the same extent as in the case of infant death.  相似文献   
102.
PURPOSE: To compare the frequency of canalicular stenosis as a side effect of weekly versus every-3-weeks docetaxel in patients with metastatic breast cancer. DESIGN: Retrospective nonrandomized comparative trial. PATIENTS AND METHODS: Eighteen patients enrolled in a phase II study of weekly docetaxel plus trastuzumab and 18 patients enrolled in a phase II study of every-3-weeks docetaxel plus doxorubicin were evaluated. Each patient underwent a comprehensive ophthalmologic examination, probing and irrigation of the nasolacrimal duct, and, in some instances, a nuclear lacrimal scan. MAIN OUTCOME MEASURES: If epiphora (excessive tearing) was reported by the patient, its time of onset was documented. In patients with epiphora, presence or absence of canalicular stenosis was evaluated on the basis of the findings on probing and irrigation. The duration of treatment with docetaxel, the dose frequency, and the cumulative dose of docetaxel were recorded in each case. RESULTS: Fourteen patients (77%) receiving weekly docetaxel plus trastuzumab had epiphora. Nine of these patients had significant anatomic narrowing of the canaliculi. Bicanalicular silicone intubation or dacryocystorhinostomy was recommended in all nine patients. Eight patients underwent surgery and experienced complete or near complete resolution of epiphora. Although two patients (11%) receiving every-3-weeks docetaxel plus doxorubicin reported transient symptoms of epiphora, neither patient was found to have narrowing of the canaliculi, and the epiphora was not severe enough to justify surgical intervention. The mean duration of docetaxel therapy for the patients in this study was 19 weeks. The mean cumulative dose of docetaxel was higher in patients with canalicular stenosis than in patients without this side effect. CONCLUSIONS: Canalicular stenosis was more common in patients receiving weekly docetaxel than in those receiving every-3-weeks docetaxel for metastatic breast cancer. Bicanalicular silicone intubation early in the course of weekly docetaxel therapy should be considered, because this intervention can prevent complete closure of the canaliculi. Once complete or near complete stenosis of the canaliculi occurs, placement of a permanent Pyrex glass tube may become necessary to overcome the blockage of tear outflow.  相似文献   
103.
104.
Where now for meta-analysis?   总被引:6,自引:0,他引:6  
  相似文献   
105.
PURPOSE: The purpose of this study was to determine the feasibility of sentinel node identification in patients with invasive cervix cancer undergoing radical hysterectomy and pelvic lymphadenectomy using preoperative and intraoperative lymphatic mapping. PATIENTS AND METHODS: Thirty-nine patients at two institutions were enrolled onto this institutional review board-approved study. All underwent preoperative lymphoscintigraphy and intraoperative lymphatic mapping with blue dye and a handheld gamma probe. Radical hysterectomy was aborted in four patients because metastatic disease was discovered on frozen section analysis of the sentinel node. RESULTS: Preoperative lymphoscintigraphy revealed at least one sentinel node in 33 patients (85%), including 21 (55%) with bilateral sentinel nodes. All 39 patients had at least one sentinel node identified intraoperatively. Eighty percent of sentinel nodes were in three pelvic locations: iliac, obturator, and parametrial (in descending order of frequency). The remaining sentinel nodes were in the common iliac and para-aortic nodal basins. A total of 132 nodes were identified clinically as sentinel nodes; 65 (49%) were both blue and hot, 35 (27%) were blue only, and 32 (24%) were hot only. Eight patients (21%) had metastatic disease. In five of these patients, sentinel nodes were the only positive lymph nodes. One patient had false-negative sentinel nodes. She had four microscopically positive parametrial nodes that were resected in continuity with the uterus. The sensitivity of the sentinel node was 87.5% and the negative predictive value was 97%. CONCLUSION: Preoperative lymphoscintigraphy and intraoperative lymphatic mapping were highly successful at identifying sentinel nodes in patients undergoing radical hysterectomy.  相似文献   
106.
107.
The study group is comprised of 234 patients (6.4%) who died out of 3680 patients treated for burn injuries during the period January 1982 to December 1997 in Kuwait. There were 112 (47.9%) males and 122 (52.1%) females and their mean age was 30 years (range 1–93) when compared with 24 years among survivors. The high mortality amongst two age groups 0–5 years (39 deaths, 16.7%) and 16–35 years (109 deaths, 46.6%) shows their vulnerability in the society. In 190 patients (81.2%) the burn injuries occurred at home. A total of 216 patients (92.3%) sustained flame burns mainly due to clothes on fire (40.6%) and cooking gas accidents (25.2%), and in 18 patients (7.7%) the burns were due to scalds. The suicidal burns occurred in 22 female and 5 male patients mainly of younger age groups. The mean percentage of burns was 71% (range 9–100%) as against 20% amongst survivors, and 195 patients (83.3%) had 50% total body surface area (TBSA) burn. Four patients (1.7%) had superficial dermal burns, 94 (40.2%) had full thickness and 136 (58.1%) had mixed with full thickness burns predominance. The associated inhalation injury was diagnosed in 132 patients (56.4%). A total of 61 patients (26.1%) had either single or multiple pre-existing diseases and 51 of them sustained flame burns. The day of death varied from 1 to 103 days (mean 16 days) but 58 patients (24.8%) died within 48 hours of post burn. A total of 120 patients (51.3%) died due to septicaemia, 83 (35.5%) due to renal failure, 28 (10.2%) due to multi-organ failure, and 7 (3.0%) due to bronchopneumonia. The overall mortality rate was 6.4%, but this has significantly lowered to 4.4% (p= < 0.01) during last four years probably due to better burn care. The study thus shows that age group 0–5 and 16–35 years, domestic accidents, flame burn, inhalation injury, and pre-existing diseases are risk factors and septicaemia as the dominant cause of death in our patients.  相似文献   
108.
Regarding the widespread use of organophosphorous pesticides (OP) especially malathion in environment and reported cases of muscle disturbances in human and animal, the present work was undertaken to explore effects of malathion subchronic exposure on rat leg skeletal muscle glucose metabolism by measuring key enzymes of glycogenolysis and glycolysis. Malathion was administered through food for 4 weeks at concentrations of 100, 200, and 400ppm to rats. Activities of enzymes including glycogen phosphorylase (GP), hexokinase (HK), and phosphofructokinase-1 (PFK) were measured in skeletal muscle homogenate of exposed rats. Levels of glucose and insulin were measured in blood. Four weeks administration of malathion at doses of 200 and 400ppm increased blood glucose concentrations to 44.4 and 60.6% of control, respectively. Malathion at doses of 200 and 400ppm increased blood insulin concentration to 36.6 and 143.2% of control, respectively. Malathion at doses of 100, 200, and 400ppm increased muscle PFK activity to 40.4, 53.5, and 83.1% of control, respectively. Malathion at doses of 400ppm increased skeletal muscle GP to 91.6% of control. Skeletal muscle HK was not influenced by malathion treatment. It is concluded that malathion influences muscle glycogenolysis and glycolysis as well as secretion of insulin from pancreas which all may explain diabetic potential of malathion.  相似文献   
109.
110.
OBJECTIVES: We sought to determine whether residential area deprivation, over and above the effect of life-course socioeconomic status or position (SEP), is associated with coronary heart disease. METHODS: We conducted a cross-sectional analysis of 4286 women aged 60 to 79 years from 457 British electoral wards. RESULTS: After adjustment for age and 10 indicators of individual life-course SEP, the odds of coronary heart disease was 27% greater among those living in wards with a deprivation score above the median compared with those living in a ward with a deprivation score equal to or below the median (odds ratio=1.27; 95% confidence interval=1.02, 1.57). CONCLUSIONS: Adverse area-level socioeconomic characteristics, over and above individual life-course SEP, are associated with increased coronary heart disease.  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