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   2036篇
  免费   162篇
  国内免费   52篇
耳鼻咽喉   18篇
儿科学   80篇
妇产科学   76篇
基础医学   251篇
口腔科学   33篇
临床医学   228篇
内科学   460篇
皮肤病学   17篇
神经病学   192篇
特种医学   95篇
外科学   280篇
综合类   59篇
一般理论   1篇
预防医学   65篇
眼科学   47篇
药学   107篇
中国医学   8篇
肿瘤学   233篇
  2023年   10篇
  2022年   34篇
  2021年   50篇
  2020年   30篇
  2019年   34篇
  2018年   52篇
  2017年   43篇
  2016年   49篇
  2015年   61篇
  2014年   85篇
  2013年   98篇
  2012年   137篇
  2011年   153篇
  2010年   88篇
  2009年   61篇
  2008年   121篇
  2007年   111篇
  2006年   87篇
  2005年   109篇
  2004年   105篇
  2003年   95篇
  2002年   71篇
  2001年   62篇
  2000年   59篇
  1999年   53篇
  1998年   27篇
  1997年   31篇
  1996年   22篇
  1995年   14篇
  1994年   10篇
  1993年   14篇
  1992年   22篇
  1991年   18篇
  1990年   31篇
  1989年   36篇
  1988年   21篇
  1987年   27篇
  1986年   23篇
  1985年   18篇
  1984年   13篇
  1982年   11篇
  1981年   3篇
  1980年   2篇
  1979年   11篇
  1978年   6篇
  1977年   5篇
  1976年   2篇
  1974年   7篇
  1973年   6篇
  1972年   4篇
排序方式: 共有2250条查询结果,搜索用时 15 毫秒
31.
Objectives: A prospective study comparing the efficiacy and side-effects of oral sulindac with intravenous indomethacin in clinically stable preterm infants (<1750 g) requiring non-invasive closure of haemodynamically significant patent ductus arteriosus.
Methodology: As maturity and birthweight are the two major determinants of ductal closure, infants were matched as closely as possible for these parameters. An eligible patient was first assigned to the sulindac group and a subsequent patient with similar gestational age (± 1 week) and birthweight (±100 g) to the previously recruited infant would automatically receive indomethacin. A total of eight infants were enrolled in each group.
Results: The ductus arteriosus was successfully closed in all eight infants receiving indomethacin, and in seven of eight infants receiving sulindac. No significant differences were found with regards to the ductal size between the two groups at diagnosis or on each of the consecutive days of treatment ( P >0.25). More renal adverse effects were encountered in the indomethacin group. Significant differences in changes from baseline value for urine output, plasma sodium, urea and creatinine concentrations were noted at 24, 48 and 72 h after commencement of treatment between the two groups ( P <0.05). All the parameters returned to normal or pre-treatment levels 48 h after stopping therapy. Unexpectedly, severe gastrointestinal complications were encountered in the sulindac group.
Conclusions: Sulindac is capable of promoting ductal constriction in clinically stable preterm infants without compromising the renal function. The spectrum of gastrointestinal complications observed in sulindac treated infants were similar to those described for indomethacin. The use of sulindac for ductal closure in the preterm infant should remain experimental.  相似文献   
32.
AIM: To ascertain the psychological, social, and educational needs of children born to mothers with HIV infection. METHODS: Review of case records of 120 children and 86 mothers. RESULTS: The cohort of 120 children were born to 92 women, and followed up for a median duration of 48 months (mean (SD) 51.1 (34.1), range 0.3-132). Sixteen children were infected with HIV, 15 were of indeterminate status, and 89 uninfected. Eighty one children (68%) were cared for by their birth mother, of whom 52% were single women and 23 (38% of 61) known to have symptomatic HIV disease. Twenty five mothers of 32 children had died; the child's mean (SD) age at maternal death was 66.9 months (37.7) (range 4-128). Compared with uninfected children, more infected children knew of their mother's diagnosis (31% v 5%) and mothers were also more likely to disclose their own illness to educational authorities (77% v 13%). A larger proportion of infected children had special educational needs (69% v 13%). Only 33 children (28%) were known not to be receiving any support from the voluntary or statutory agencies. CONCLUSION: The results highlight the multiple needs of children living with maternal HIV infection, which require dedicated resources and commitment from health, education, and social work agencies and the voluntary sector. We propose the model of chronic illness as the standard of care for these children.  相似文献   
33.
Purpose: A single-institution phase II trial of Temodal (temozolomide, SCH52365) in Chinese patients with advance nasopharyngeal carcinoma was undertaken to determine the efficacy and safety of the drug in this population. Methods: A total of 14 patients with metastatic or locoregionally recurrent nasopharyngeal carcinoma were entered into the study. One patient was unevaluable. Temodal was given at doses of 150 or 200 mg/m2 daily on days 1–5 every 28 days. Results: In all, 30 cycles of Temodal were given with no significant toxicity. All 13 (100%) evaluable patients had progressive disease after 2 (84.6%) or 4 (15.4%) courses. Conclusion: Temodal given on this schedule has no activity in advanced nasopharyngeal carcinoma. Received: 9 January 1998 / Accepted: 4 February 1998  相似文献   
34.
Early failure of intramedullary nailing for proximal humeral fractures   总被引:5,自引:0,他引:5  
Bernard J  Charalambides C  Aderinto J  Mok D 《Injury》2000,31(10):330-792
  相似文献   
35.
This study aimed to (a) investigate the effect of using a hearing aid in conjunction with a cochlear implant in opposite ears on speech perception in quiet and in noise, (b) identify the speech information obtained from a hearing aid that is additive to the information obtained from a cochlear implant, and (c) explore the relationship between aided thresholds in the nonimplanted ear and speech perception benefit from wearing a hearing aid in conjunction with a cochlear implant in opposite ears.Fourteen adults who used the Nucleus 24 cochlear implant system in 1 ear participated in the study. All participants had either used a hearing aid in the nonimplanted ear for at least 75% of waking hours after cochlear implantation, and/or, hearing loss less than 90 dB HL in the low frequencies in the nonimplanted ear. Speech perception was evaluated in 3 conditions: cochlear implant alone (CI), hearing aid alone (HA), and cochlear implant in conjunction with hearing aid in opposite ears (CIHA). Three speech perception tests were used: consonant-vowel nucleus-consonant (CNC) words in quiet, City University of New York style (CUNY) sentences in coincident signal and noise, and spondees in coincidental and spatially separated signal and noise. Information transmission analyses were performed on the CNC responses.Of the 14 participants tested, 6 showed significant bimodal benefit on open-set speech perception measures and 5 showed benefit on close-set spondees. However, 2 participants showed poorer speech perception with CIHA than CI in at least 1 of the speech perception tests. Results of information transmission analyses showed that bimodal benefit (performance with CIHA minus that with CI) in quiet arises from improved perception of the low frequency components in speech. Results showed that participants with poorer aided thresholds in the mid-to-high frequencies demonstrated greater bimodal benefit. It is possible that the mid-to-high frequency information provided by the hearing aids may be conflicting with the cochlear implants.  相似文献   
36.
This study has shown that cyclophosphamide treatment of the insectivore Suncus murinus, causes a down regulation in both muscarinic and P2X receptors, together with a reduced responsiveness to exogenous histamine (0.3 mM) in the urinary bladder. Electrical field stimulation (70 V, 0.3 ms, 0.5-16 Hz, 10 s every 5 min) of bladders from both control and cyclophosphamide-treated animals showed identical responses. Since post-junctional alterations have been revealed by the reduced responsiveness to exogenous carbachol (0.1 microM-3 mM) and beta,gamma-methylene ATP (0.3-300 microM), it would appear that in the bladders of cyclophosphamide-treated animals there is also a pre-junctional effect, increased transmitter release compensating for the down regulation of the receptors. As the pattern of neurotransmission of the bladder of suncus more closely resembles that of human detrusor than other commonly studied laboratory animals, this insectivore appears to be a useful animal model for the study of bladder neurotransmission in pathophysiological conditions.  相似文献   
37.
背景和目的:罗格列酮与阿伐他汀联合疗法已经被证实对于2型糖尿病患者的血糖控制以及脂质水平都有益处。本试验将通过检测罗格列酮与阿伐他汀联合疗法对于2型糖尿病患者的生物标记水平的作用来研究该联合疗法对血管炎的作用。方法:30例患有2型糖尿病和高脂血症的患者被纳入治疗。对这些患者给予罗格列酮单一疗法4mg/d,持续3个月,然后在接下来的3个月中给予这些患者阿伐他汀10mg/d作为联合疗法。在研究开始时,罗格列酮单一疗法之后以及罗格列酮与阿伐他汀联合治疗之后测量炎性生物标记物,包括高敏C-反应蛋白(hs-CRP)、基质金属蛋白酶9(MMP…  相似文献   
38.
39.
Objective To explore the characteristics of arrhythmogenic right ventricular cardiomyopathy (ARVC). Methods Seven patients with arrhythmogenic right ventricular cardiomyopathy and 34 members of three families were studied. All patients and family members underwent history collection, clinical examination, electrocardiogram (ECG), two-dimensional echocardiography (2-DE) and a signal averaging electrocardiogram. Programmed ventricular stimulation was performed in five patients. Results All patients and family members had normal morphologic characteristics and normal function of the left ventricular by 2-DE. Fourteen persons had abnormal findings indicating ARVC. Five had enlargement of the right ventricular with diffused hypocontractility, eight had thin and systolic bulging in the focal anterior wall with hypokinesia and one had bulging of the inferior wall. Twenty-five persons (seven patients and 18 family members) had abnormal findings in ECG. Positive ventricular late potential was recorded in 13 persons (six patients). Two to three monomorphic ventricular tachycardia (VT) with left bundle branch block (LBBB) configurations were induced in five patients. Ventricular fibrillation was induced in two patients during the electrophysiologic study (EPS). Five patients had very high pacing threshold and/or ineffective pacing in one or many regions of the right ventricle. Two members of one family died suddenly. One member was a dwarf with ARVC. Spontaneous VT with a left bundle branch block (LBBB) configuration was recorded in five patients, polymorphic VT with extremely short coupling interval in one, and premature ventricular complexes with LBBB configuration in 12 (six patients). Conclusion Our familial study strongly suggests that ARVC may be a hereditary disease and it is helpful in the diagnosis and detection of ARVC. The most common manifestations were abnormal structure and function of the right ventricle and abnormal ECG of repolarization and ventricular arrhythmia which originates from the right ventricle.  相似文献   
40.
Calcineurin and mTOR inhibitors are commonly used immunosuppressive agents with narrow therapeutic range. As the drugs are mainly metabolized by the P450 cytochrome system, the interaction between food and herbs are also commonly seen and affect the drug levels. We present a case of a kidney transplant recipient with toxic therapeutic levels of cyclosporine A and sirolimus due to interaction between the immunosuppressive agents and Chinese herbal tea. Ingredients within the herbal tea were reported to have inhibitory effect on cytochrome CYP3A4 in-vitro studies. Transplant recipients should be alert that there may be potent interaction between the immunosuppressive drugs and herbs resulting in adverse effect on allograft function.  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