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   1264篇
  免费   97篇
  国内免费   11篇
耳鼻咽喉   40篇
儿科学   35篇
妇产科学   20篇
基础医学   186篇
口腔科学   34篇
临床医学   86篇
内科学   246篇
皮肤病学   18篇
神经病学   55篇
特种医学   39篇
外科学   335篇
综合类   40篇
预防医学   59篇
眼科学   10篇
药学   85篇
中国医学   9篇
肿瘤学   75篇
  2023年   16篇
  2022年   34篇
  2021年   46篇
  2020年   28篇
  2019年   28篇
  2018年   33篇
  2017年   35篇
  2016年   23篇
  2015年   31篇
  2014年   44篇
  2013年   55篇
  2012年   100篇
  2011年   83篇
  2010年   51篇
  2009年   38篇
  2008年   76篇
  2007年   58篇
  2006年   64篇
  2005年   58篇
  2004年   63篇
  2003年   60篇
  2002年   51篇
  2001年   16篇
  2000年   10篇
  1999年   15篇
  1998年   5篇
  1997年   7篇
  1996年   6篇
  1995年   10篇
  1994年   7篇
  1993年   8篇
  1992年   12篇
  1991年   11篇
  1990年   14篇
  1989年   10篇
  1988年   11篇
  1987年   8篇
  1986年   11篇
  1985年   13篇
  1984年   10篇
  1983年   10篇
  1982年   9篇
  1981年   12篇
  1980年   8篇
  1979年   22篇
  1978年   10篇
  1977年   11篇
  1976年   5篇
  1975年   8篇
  1974年   3篇
排序方式: 共有1372条查询结果,搜索用时 31 毫秒
1.
A Cott  W Parkinson  M Fabich  M Bédard  R Marlin 《Pain》1992,51(1):49-56
Thirty-four patients having chronic idiopathic headaches participated in a long-term study comparing autogenic relaxation training alone (REL) with combinations of relaxation and electromyographic biofeedback (REL + EMG) or relaxation and temperature biofeedback (REL + TEMP). Assignment to treatment conditions was balanced on demographics and clinical characteristics, as well as headache classification according to muscle contraction or vascular headache symptomatology. The results indicate that REL + TEMP produced no additional improvements over REL following the 8-week treatment program, or at 6-month, or 12-month follow-up. However, REL + EMG produced significantly greater reductions in headache activity measures than the REL and REL + TEMP conditions at all post-treatment time points. Headache activity continued to improve over the follow-up period independent of treatment condition. These data indicate that EMG biofeedback augments long-term clinical improvements in headache patients who undergo autogenic relaxation training.  相似文献   
2.
宣肺清热颗粒剂稳定性研究   总被引:1,自引:0,他引:1  
目的:研究宣肺清热颗粒剂中橙皮甙热稳定性变化,为该颗粒剂有效期的确定、制剂生产、贮存条什提供实验参考依据。方法:采用加速实验法对橙皮甙热稳定性进行研究,用甲醇超声提取样品,HPLC进行含量测定。根据Arrhenius公式处理数据。结果:Arrhenius公式得室温下的速度常数K298=3.38×10-5/h,得出常温下该颗粒剂以橙皮甙为指标的有效期为3.6年。结论:宣肺清热颗粒剂稳定性好,初步符合中药稳定性要求。  相似文献   
3.
Mice whose tumor necrosis factor alpha (TNF-alpha) genes were disrupted developed higher levels of parasitemia than wild-type mice following infection with Trypanosoma congolense IL1180 or T. brucei brucei GUTat3.1, confirming the results of earlier studies. To determine whether TNF-alpha directly affects the growth of these and other bloodstream forms of African trypanosomes, we studied the effects of recombinant mouse, human, and bovine TNF-alpha on the growth of two isolates of T. congolense, IL1180 and IL3338, and two isolates of T. brucei brucei, GUTat3.1 and ILTat1.1, under axenic culture conditions. The preparations of recombinant TNF-alpha used were biologically active as determined by their capacity to kill L929 cells. Of five recombinant TNF-alpha lots tested, one lot of mouse TNF-alpha inhibited the growth of both isolates of T. brucei brucei and one lot of bovine TNF-alpha inhibited the growth of T. brucei brucei ILTat1.1 but only at very high concentrations and without causing detectable killing of the parasites. The other lots of mouse recombinant TNF-alpha, as well as human TNF-alpha, did not affect the growth of any of the test trypanosomes even at maximal concentrations that could be attained in the culture systems (3,000 to 15,000 U of TNF-alpha/ml of medium). These results suggest that exogenously added recombinant TNF-alpha generally does not inhibit the growth of African trypanosomes under the culture conditions we used. The impact of TNF-alpha on trypanosome parasitemia may be indirect, at least with respect to the four strains of trypanosomes reported here.  相似文献   
4.
Alpha‐mannosidosis (AM) is a very rare (prevalence: 1/500000 births) autosomal recessive lysosomal storage disorder. It is characterized by multi‐systemic involvement associated with progressive intellectual disability, hearing loss, skeletal anomalies, and coarse facial features. The spectrum is wide, from very severe and lethal to a milder phenotype that usually progresses slowly. AM is caused by a deficiency of lysosomal alpha‐mannosidase. A diagnosis can be established by measuring the activity of lysosomal alpha‐mannosidase in leucocytes and screening for abnormal urinary excretion of mannose‐rich oligosaccharides. Genetic confirmation is obtained with the identification of MAN2B1 mutations. Enzyme replacement therapy (LAMZEDER) was approved for use in Europe in August 2018. Here, we describe seven individuals from four families, diagnosed at 3–23 years of age, and who were referred to a clinical geneticist for etiologic exploration of syndromic hearing loss, associated with moderate learning disabilities. Exome sequencing had been used to establish the molecular diagnosis in five cases, including a two‐sibling pair. In the remaining two patients, the diagnosis was obtained with screening of urinary oligosaccharides excretion and the association of deafness and hypotonia. These observations emphasize that the clinical diagnosis of AM can be challenging, and that it is likely an underdiagnosed rare cause of syndromic hearing loss. Exome sequencing can contribute significantly to the early diagnosis of these nonspecific mild phenotypes, with advantages for treatment and management.  相似文献   
5.
Hearing impairment is the most frequent sensory defect in children, with a genetic basis in about 50% of cases. Several point mutations and deletions in mitochondrial DNA (mtDNA) have been identified in non-syndromic sensorineural hearing loss (NSSNHL). Beside the frequent A1555G mutation, a number of mutations in tRNAs have been reported recently, but their incidence remains unknown. We identified the T7511C mutation in the tRNASer(UCN) gene in two French families with isolated deafness. Maternal transmission was obvious in both. The 15 patients with hearing impairment exhibited a variable disease phenotype in terms of onset, severity, and progression. T7511C was present in all the patients screened. Homoplasmic and heteroplasmic levels were observed and did not correlate with the severity of the disease. T7511C was also present in 12 hearing offspring of the oldest deaf mothers, confirming the existence of modulatory factors. Our data suggest that this mtDNA mutation should be screened for in all cases of familial NSSNHL compatible with maternal transmission.  相似文献   
6.
This paper presents results of a study to establish a link between neurocognitive psychophysiological and psychological type data through the investigation of differences in topographic auditory event-related potential (AERP) (P300) patterns in strongly introverted (n = 17) and strongly extraverted ( = 16) high school males as identified by the Myers Briggs Type Indicator. Group data files were created for the auditory event related potential task and converted to ASCII form. Amplitude values were evaluated at each scalp site. Kruskal Wallis one way analysis of variance was performed to evaluate group differences. In processing of infrequent, target stimuli, the amplitude of the P300 waveform for introverts was higher than for extraverts. When processing for non-target stimuli was subtracted from target stimuli, statistical differences were found over nine central, parietal, and occipital sites. The findings support and extend theories of biologically-based and bio-psycho-social typology.  相似文献   
7.
Sensorineural hearing defect and goiter are common features of Pendred's syndrome. The clinical diagnosis of Pendred's syndrome remains difficult because of the lack of sensitivity and specificity of the thyroid signs. The identification of PDS as the causative gene allowed molecular screening and enabled a re-evaluation of the syndrome to identify potential diagnostic characteristics. This report presents the clinical and genotypic findings of 30 French families, for whom a diagnosis of Pendred's syndrome had been made. Twenty-seven families had at least one mutated allele. Twenty-eight different mutations were identified, 11 of which had never been previously reported. The main clinical characteristics were: early hearing loss, fluctuation in terms of during deafness evolution, and the presence of an enlarged vestibular aqueduct.  相似文献   
8.
Valproic acid (VPA) is used in the treatment of seizure disorders often present in patients with cerebral palsy. The charts of 114 patients with cerebral palsy were reviewed to evaluate the effect of VPA on blood loss during spine surgery. Forty-one patients had seizure disorders. Of these, 18 were taking VPA as monotherapy (group III) and the remaining 23 patients were taking other antiseizure medications, including two taking VPA (group II). There was a significant increase in the number of patients with abnormal bleeding times and a significant difference (p < 0.001) in blood loss (ml/kg) in patients taking VPA as monotherapy (38.6 ml/kg vs. 30.0 ml/kg). There was also increased blood-product administration postoperatively in the VPA monotherapy patients. Physicians should be aware of this potential association between VPA use and increased blood loss. The routine laboratory tests of complete blood count, prothrombin time, and partial thromboplastin time will not adequately screen for the platelet-mediated effects of VPA.  相似文献   
9.
This is a retrospective study involving 100 anovulatory women with polycystic ovarian syndrome (PCOS) who had laparoscopic ovarian drilling (LOD) between January 1995 and May 2002 at the Royal Berkshire Hospital, Reading, a large district general hospital (DGH). The aim was to evaluate the efficacy of LOD in the treatment of women with anovulatory PCOS in a DGH setting. We also looked at the factors predicting the clinical outcome to be able to counsel the patients pre-operatively. The study showed that the spontaneous pregnancy rate after LOD was 32.46%. A further 28.5% conceived after induction of ovulation with clomiphene citrate (CC) or purified follicular stimulating hormone (Metrodin HP), with a cumulative pregnancy rate of 74%. We did not find a significant difference in the luteinising hormone to follicular stimulating hormone (LH:FSH) ratio of greater than 2.5, LH level of greater than 10 IU/l, body mass index (BMI), age or duration of infertility between the group of women who conceived and those who failed to conceive, in response to LOD.  相似文献   
10.
ObjectiveTo describe a systematic process of transforming paper registers into a digital system optimized to enhance service provision and fulfil reporting requirements.MethodsWe designed a formative study around primary health workers providing reproductive, maternal, newborn and child health services in three countries in Bangladesh, Indonesia and Pakistan. The study ran from November 2014 to June 2018. We developed a prototype digital application after conducting a needs assessment of health workers’ responsibilities, workflows, routine data requirements and service delivery needs. Methods included desk reviews, focus group discussions, in-depth interviews; data mapping of paper registers; observations of health workers; co-design workshops with health workers; and usability testing. Finally, we conducted an observational feasibility assessment to monitor uptake of the application.FindingsResearchers reviewed a total of 17 paper registers across the sites, which we transformed into seven modules within a digital application running on mobile devices. Modules corresponded to the services provided, including household enumeration, antenatal care, family planning, immunization, nutrition and child health. A total of 65 health workers used the modules during the feasibility assessment, and average weekly form submissions ranged from 8 to 234, depending on the health worker and their responsibilities. We also observed variability in the use of modules, requiring consistent monitoring support for health workers.ConclusionLessons learnt from this study shaped key global initiatives and resulted in a software global good. The deployment of digital systems requires well-designed applications, change management and strengthening human resources to realize and sustain health system gains.  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