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   4064篇
  免费   382篇
  国内免费   46篇
耳鼻咽喉   52篇
儿科学   129篇
妇产科学   184篇
基础医学   613篇
口腔科学   71篇
临床医学   389篇
内科学   891篇
皮肤病学   29篇
神经病学   246篇
特种医学   217篇
外科学   580篇
综合类   105篇
一般理论   3篇
预防医学   213篇
眼科学   159篇
药学   254篇
中国医学   20篇
肿瘤学   337篇
  2023年   22篇
  2022年   48篇
  2021年   71篇
  2020年   66篇
  2019年   85篇
  2018年   115篇
  2017年   88篇
  2016年   75篇
  2015年   107篇
  2014年   120篇
  2013年   177篇
  2012年   222篇
  2011年   232篇
  2010年   169篇
  2009年   142篇
  2008年   198篇
  2007年   200篇
  2006年   246篇
  2005年   221篇
  2004年   237篇
  2003年   200篇
  2002年   200篇
  2001年   190篇
  2000年   117篇
  1999年   116篇
  1998年   76篇
  1997年   67篇
  1996年   52篇
  1995年   58篇
  1994年   53篇
  1993年   37篇
  1992年   49篇
  1991年   51篇
  1990年   36篇
  1989年   46篇
  1988年   44篇
  1987年   37篇
  1986年   38篇
  1985年   24篇
  1984年   18篇
  1983年   19篇
  1982年   17篇
  1981年   12篇
  1980年   13篇
  1979年   14篇
  1978年   7篇
  1977年   10篇
  1976年   8篇
  1975年   14篇
  1974年   6篇
排序方式: 共有4492条查询结果,搜索用时 16 毫秒
31.
Primary T-cell lymphoma of the gastrointestinal tract is a rare and usually aggressive disorder that may be associated with celiac disease. The authors describe a unique case of a clonal proliferation of CD8+ T cells involving the oral mucosa, ileum, and colon of a 35-year-old man that has regressed spontaneously and recurred numerous times over a 9-year period without treatment. The patient's symptoms were limited to occasional rectal bleeding and recurring painful oral ulcers. Within the intestine, these collections of small T cells induced minimal architectural distortions and did not show extensive epitheliotrophism. Polymerase chain reaction and sequencing analyses revealed that the identical T-cell clone has been present for more than 9 years and in different mucosal locations in this patient. This may represent a unique T-cell lymphoproliferative process akin to a mucosal counterpart of lymphomatoid papulosis of the skin.  相似文献   
32.
33.
Smith-Magenis syndrome is caused by a 17p11.2 deletion. It associates mental retardation, facial dysmorphism and brachydactyly; aberrant behavior and major sleep problems are present in 70% of the cases. It is probably under-diagnosed because the facial abnormalities are mild and the behavioral problems with hyperactivity and self-injuries are dominant, leading to the diagnosis of psychiatric pathology. However these behavioral problems are sufficiently characterized to allow the diagnosis of the syndrome and look for a 17p11.2 microdeletion. Otorhinolaryngologic, ophtalmologic, cardiac and renal abnormalities can be associated and their evaluation is necessary. Smith-Magenis syndrome is considered as a contiguous gene syndrome. Genes have been mapped and isolated to the critical region, but their participation in the pathogenesis of the syndrome remains unclear.  相似文献   
34.
The aim of the present study was to investigate whether cisplatin would enhance the radioresponse of a human tumour xenograft when given in different schedules combined with accelerated fractionated radiation therapy. A human squamous carcinoma of the hypopharynx, FaDu, was grown in the thigh of athymic nude mice. Tumours were exposed to twice-daily 2-Gy fractions, applied 6 h apart over 2 weeks, 5 days a week, alone or combined with cisplatin given at maximally tolerated doses in three different schedules: (1) i.p. as a single bolus (SB) or (2) i.p. as a daily bolus at 30 min before the first daily radiation fraction or (3) s.c. as a continuous infusion through a mini-osmotic pump over 13 days, commencing 24 h prior to the first daily radiation fraction. The end point for the study was tumour growth delay (TGD), calculated as the difference between the delay in regrowth to 200% of the initial tumour size in treated versus control mice. SB cisplatin plus radiation showed only an additive effect on TGD, whereas daily-bolus and continuous-infusion cisplatin demonstrated a greater than additive effect when combined with accelerated fractionated radiation in this human tumour model. Cisplatin appears to be especially beneficial as a radiation enhancer when given throughout the course of radiation. Received: 15 December 1996 / Accepted: 25 March 1997  相似文献   
35.
IntroductionIsoniazid preventive therapy (IPT) can reduce the risk of tuberculosis (TB) in children living with HIV (CLHIV), but data on the outcomes of the IPT cascade in CLHIV are limited.MethodsWe evaluated the IPT cascade among CLHIV aged <15 years and newly enrolled in HIV care in eight HIV clinics in western Kenya. Medical record data were abstracted from September 2015 through July 2019. We assessed the proportion of CLHIV completing TB symptom screening, IPT eligibility assessment, IPT initiation and completion. TB incidence rate was calculated stratified by IPT initiation and completion status. Risk factors for IPT non‐initiation and non‐completion were assessed using Poisson regression with generalized linear models.ResultsOverall, 856 CLHIV were newly enrolled in HIV care, of whom 98% ([95% CI 97–99]; n = 841) underwent screening for TB symptoms and IPT eligibility. Of these, 13 (2%; 95% CI 1–3) were ineligible due to active TB and 828 (98%; 95% CI 97–99) were eligible. Five hundred and fifty‐nine (68%; 95% CI 64–71) of eligible CLHIV initiated IPT; median time to IPT initiation was 3.6 months (interquartile range [IQR] 0.5–10.2). Overall, 434 (78%; 95% CI 74–81) IPT initiators completed. Attending high‐volume HIV clinics (aRR = 2.82; 95% CI 1.20–6.62) was independently associated with IPT non‐initiation. IPT non‐initiation had a trend of being higher among those enrolled in the period 2017–2019 versus 2015–2016 (aRR = 1.91; 0.98–3.73) and those who were HIV virally non‐suppressed (aRR = 1.90; 95% CI 0.98–3.71). Being enrolled in 2017–2019 versus 2015–2016 (aRR = 1.40; 1.01–1.96) was independently associated with IPT non‐completion. By 24 months after IPT screening, TB incidence was four‐fold higher among eligible CLHIV who never initiated (8.1 per 1000 person years [PY]) compared to CLHIV who completed IPT (2.1 per 1000 PY; rate ratio [RR] = 3.85; 95% CI 1.08–17.15), with a similar trend among CLHIV who initiated but did not complete IPT (8.2/1000 PY; RR = 4.39; 95% CI 0.82–23.56).ConclusionsDespite high screening for eligibility, timely IPT initiation and completion were suboptimal among eligible CLHIV in this programmatic cohort. Targeted programmatic interventions are needed to address these drop‐offs from the IPT cascade by ensuring timely IPT initiation after ruling out active TB and enhancing completion of the 6‐month course to reduce TB in CLHIV.  相似文献   
36.
The concentrations of human chorionic gonadotropin and prolactin in the cyst fluid of molar tissue were compared with that of normal amniotic fluid. Molar fluid was aspirated from the vesicles of molar tissue in eight women (duration of amenorrhea 14.1 +/- 1 week, mean +/- SEM). Amniotic fluid was obtained at amniocentesis in 24 women (mean duration of amenorrhea 15.9 +/- 0.2 week). Hormones were measured by specific radioimmunoassay. The concentrations (mean +/- SEM) of human chorionic gonadotropin in molar fluid and amniotic fluid were 581,829 +/- 112,581 and 3187 +/- 505 mlU/ml (p less than 0.001), respectively. For prolactin the levels in molar fluid and amniotic fluid were 44 +/- 24 and 1962 +/- 313 ng/ml (p less than 0.001), respectively. These data demonstrate that molar fluid contains 182-fold higher levels of human chorionic gonadotropin and 45-fold lower levels of prolactin than amniotic fluid obtained from normal pregnant women with a similar duration of amenorrhea. In addition to altered endocrine function of the trophoblast, there may be altered prolactin secretion from the decidua in molar pregnancy as compared with normal pregnancy. Further research is required to evaluate prolactin production from decidua of molar pregnancy.  相似文献   
37.
38.

Aim of study

In this study, we have investigated the analgesic and anti-arthritic effects of a traditional Chinese medicine (TCM) combination of Lingzhi and San Miao San (SMS) in a rat model of arthritis induced by Freund's complete adjuvant (FCA).

Materials and methods

Sprague–Dawley rats were induced with monoarthritis by single unilateral injection of FCA into the knee joint. The TCM combination was administered to the rats daily by intraperitoneal injection (50 mg/(kg day)) or via oral administration (500 mg/(kg day)) for 7 days before induction of arthritis and 7 days after. Extension angle that provoked struggling behavior, and size and blood flow of the rat knees were measured to give indexes of allodynia, edema, and hyperemia, respectively. The extent of cell infiltration, tissue proliferation, and erosions of joint cartilage provided additional indexes of the arthritis condition.

Results

FCA injection produced significant allodynia, edema, hyperemia, immune cell infiltration, synovial tissue proliferation, and erosions of joint cartilage in the ipsilateral knees compared with the contralateral saline-injected knees. Intraperitoneal injection of the TCM combination (50 mg/(kg day)) suppressed allodynia, edema, and hyperemia in the inflamed knees, and oral administration (500 mg/(kg day)) suppressed edema and hyperemia. Histological examination showed that the TCM administered by either route reduced immune cell infiltration and erosion of joint cartilage.

Conclusions

These findings suggest the Lingzhi and SMS formulation has analgesic and anti-inflammatory effects in arthritic rat knees, and concur to previous clinical studies that showed the TCM combination reduced pain in rheumatoid arthritis patients, and extends its possible benefit to suppression of inflammatory symptoms in these patients.  相似文献   
39.

Background

We conducted a controlled, non-randomized observational study on 64 participants suffering from rheumatoide arthritis of hands and/or feet.

Methods

32 inpatient participants were fasting 7–14 days according to Buchinger's method. In addition they bathed their hands and/or feet for 20 minutes in a Chinese medical bath on a daily basis (group A). The other 32 patients only bathed their hands and/or feet in the Chinese medical bath (group B). Both patient collectives completed a questionaire concerning pain recognition, morning stiffness, mobility, additional medication and therapies, co-medication, co-therapies and side effects.

Results

Both therapeutical groups showed a significant reduction of pain, morning stiffness and an improvement of mobility. There were no significant differences concerning their efficacy of treatment. In group A, additional medication could be reduced in 50 % of these participants, as opposed to 23 % of the patients in group B. This result showed no statistical significance due to the small group size. 10 % of the patients in group A noticed side effects of the therapy as opposed to 26 % of the patients in group B.

Conclusions

The study shows that the treatment with the external Chinese medical bath may provide a treatment option for patients with rheumatoide arthritis of the hands and/or feet who are not suited for fasting therapy.  相似文献   
40.
OBJECTIVE: To evaluate expectation and knowledge on obstetric ultrasound examination in the first and second trimester in a Chinese population. METHOD: A cross-sectional survey was conducted in a university obstetric clinic in Hong Kong. Chinese pregnant women who underwent the first trimester early scan sessions, or the second trimester anomaly scan sessions were invited to complete a self-administered questionnaire, which contained items on their knowledge, expectation, and sociodemographic characteristics. RESULTS: In all 276 eligible pregnant women (117 in the first trimester and 159 in the second trimester) were recruited. Although 249 women (90.2%) claimed they understood the indication of the ultrasound examination, only 93 of them were correct (33.7%). The median perceived overall-detection rate for structural abnormalities was 66.5%. Living in Hong Kong for more than 7 years was significantly associated with higher knowledge level and expectation from ultrasound examination. Attaining tertiary education level was also significantly associated with higher knowledge level. Over 90% of the pregnant women studied wished to know the fetal gender from the anomaly scan examination. CONCLUSION: Knowledge of Chinese pregnant women on ultrasound was generally unsatisfactory. Understanding their limitation of knowledge and expectations helps to devise appropriate education in the local setting.  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