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   21413篇
  免费   1510篇
  国内免费   81篇
耳鼻咽喉   146篇
儿科学   677篇
妇产科学   499篇
基础医学   3395篇
口腔科学   399篇
临床医学   2123篇
内科学   4242篇
皮肤病学   464篇
神经病学   2301篇
特种医学   528篇
外科学   1981篇
综合类   120篇
一般理论   27篇
预防医学   2252篇
眼科学   430篇
药学   1244篇
中国医学   40篇
肿瘤学   2136篇
  2023年   178篇
  2022年   283篇
  2021年   648篇
  2020年   427篇
  2019年   611篇
  2018年   692篇
  2017年   537篇
  2016年   614篇
  2015年   700篇
  2014年   851篇
  2013年   1193篇
  2012年   1696篇
  2011年   1682篇
  2010年   953篇
  2009年   858篇
  2008年   1492篇
  2007年   1438篇
  2006年   1312篇
  2005年   1258篇
  2004年   1100篇
  2003年   1132篇
  2002年   980篇
  2001年   145篇
  2000年   102篇
  1999年   137篇
  1998年   186篇
  1997年   155篇
  1996年   122篇
  1995年   125篇
  1994年   105篇
  1993年   101篇
  1992年   58篇
  1991年   73篇
  1990年   53篇
  1989年   49篇
  1988年   28篇
  1987年   46篇
  1986年   52篇
  1985年   55篇
  1984年   57篇
  1983年   50篇
  1982年   72篇
  1981年   56篇
  1980年   46篇
  1979年   38篇
  1978年   34篇
  1976年   36篇
  1975年   30篇
  1974年   35篇
  1973年   31篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
51.
Background: Scleromyxoedema is a rare disease of unknown aetiology that is characterized by deposition of mucin and sclerotic induration of the skin; it is associated with paraproteinaemia. Patients suffer from progressive disability due to immobilization and cosmetic disfigurement. Treatment of scleromyxoedema is a therapeutic challenge. The antimalarial hydroxychloroquine has a rapid and reliable effect in reticular erythematous mucinosis. Patients and methods: Four consecutive patients (two women, two men; median age: 50 years) with scleromyxoedema, three of them with IgG λ paraprotein, were treated with hydroxychloroquine. Treatment was initiated with 600 mg p. o. for 10 days, followed by 400 mg for at least 4 weeks, and 200 mg thereafter. Results: Complete remission of skin manifestations was achieved in one patient, whereas three patients achieved a partial remission of 61+, 5 and 25 months' duration. Notably, three patients felt increased mobility and reduced firmness of skin during the first week of treatment, which was reflected in a rapid reduction in dermal thickness. In one patient, dysphagia was reverted as evidenced by normalization of oesophageal clearance. Paraproteinaemia was not influenced at all. Side effects included one case of electroretinogram abnormalities after 19 months of therapy and one case of leucopenia after 3 months. Conclusion: Hydroxychloroquine is an effective form of therapy for scleromyxoedema, leading to rapid and prolonged alleviation of symptoms.  相似文献   
52.
Background: A survival disadvantage for black women with brest cancer, which persists after controlling for stage of the disease, has been reported. This study investigates the effects of race and socioeconomic status (SES) on breast cancer survival after controlling for age, stage, histology, and type of treatment. Methods: Kaplan-Meier and Cox proportional hazards models were used to analyze the interaction between race and SES in predicting survival in a sample of 163 black, 205 Hispanic, and 964 white women with breast cancer treated at M. D. Anderson Cancer Center (1987–1991). Results: The results of univariate and multivariate analyses indicate that race was not a significant predictor of survival after adjusting for SES and other confounding factors such as demographic and disease characteristics. SES remained a significant predictor of survival after all adjustments were made. There was no evidence of differences in type of treatment by race or SES if adjustments were made for stage. Conclusions: These results suggest that institutional factors, such as access to treatment, do not explain survival differences by race or SES. Other factors associated with low SES, such as life-style and behavior, may affect survival.  相似文献   
53.
In a population-based longitudinal cohort study, we tested the hypothesis that children growing up in a high-traffic polluted urban area (UA) in the Athens' basin have higher prevalence of allergies and sensitization when compared with those growing up in a Greek provincial rural area (RA). We recruited 478 and 342 children aged 8-10 living in the UA and the RA, respectively. Respiratory health was assessed by a parent-completed questionnaire in three phases: 1995-96 (phase 1), 1999-2000 (phase 2), 2003-04 (phase 3) and skin-prick testing to common indoor and outdoor aeroallergens was performed at phases 1 and 2. Reported asthma and eczema did not differ between the two areas, whereas reported hay fever was persistently more prevalent in the UA than in the RA (16.5%, 17.0%, 18.2% vs. 7.0%, 8.3%, 9.6%, respectively). Sensitization was more prevalent in the UA at both phases (19.0% vs. 12.1% in phase 1, 20.0% vs. 14.1% in phase 2). Residential area contributed independently to sensitization to >or=1 aeroallergens (OR: 0.29; 95% CI: 0.13-0.66; p = 0.003) and to polysensitization (OR: 0.28; 95% CI: 0.10-0.82; p = 0.020) in phase 1. These associations were independent of farming practices. No significant contributions were found in phase 2. Our results suggest that long-term exposure to urban environment is associated with a higher prevalence of hay fever but not of asthma or eczema. The negative association between rural living and the risk of atopy during childhood, which is independent of farming practices, implies that it is mainly driven by an urban living effect.  相似文献   
54.
Oral N-acetylcysteine supplementation in nine young healthy females induced a quick and highly significant decrease in plasma homocysteine levels and an increase in whole blood concentration of the antioxidant glutathione. N-acetylcysteine impresses as an efficient drug in lowering homocysteine concentration and might be beneficial for individuals with hyperhomocysteinemia who are at increased risk of cardiovascular disease.  相似文献   
55.
Our purpose was to investigate the eliciting threshold concentration of formaldehyde in formaldehyde-sensitive individuals in the occluded and non-occluded patch teat and to evaluate the relationship in repeated open application test (ROAT) with a product containing a formaldehyde releaser. 20 formaldehyde-sensitive patients and a control group of 20 healthy volunteer were included in the study. Occluded and non-occluded patch tests with formaldehyde solutions form 25 to 10,000 ppm. and ROAT for I week with a leave-on cosmetic product containing on average 300 ppm formaldehyde. Were carried out simultaneously on each subject. In the occluded patch test. 1/2 of the 20 patients only reacted to 10,000 ppm formaldehyde. 9 reacted to 5,000 ppm. 3 reacted to 1.000 ppm. 2 reacted to 500 ppm and I reacted to 25 ppm. No definite positive reactions were observed in the non-occluded patch test or in the ROAT No positive reactions were observed in the control group to any of the test procedures. We concluded that the threshold concentration for occluded patch test to formaldehyde in formaldehyde-sensitive patients was 250 ppm. The threshold in occluded patch test corresponded to the degree of sensitivity Definite positive reactions in the ROAT were not seen, either indicating that they are unlikely to happen with the type of product used or that the exposure time was too short.  相似文献   
56.
BACKGROUND: A change in neural responsiveness may occur as the result of allergic inflammation in the lower airways as well as in the upper airways. In the lower airways, capsaicin cough sensitivity is known to reflect sensory neural reactivity. OBJECTIVE: The aim of this study was to establish whether allergic inflammation changes airway neural sensory reactivity during prolonged allergen exposure. METHODS: Ten nonsmoking patients with birch pollen-allergic asthma performed a capsaicin inhalation challenge twice, once in the off-pollen season and once during the pollen season. The number of coughs and symptoms induced by capsaicin were recorded and compared with those of healthy control subjects. RESULTS: The response to capsaicin, expressed as number of coughs, increased in a dose-dependent manner during both tests. Before the season, the response was similar to that of healthy control subjects, but during the pollen season, the reactivity was significantly increased. Variations in forced expiratory volume in 1 second were not significant before and after each challenge, and values did not change during the pollen season as compared with the winter season. CONCLUSIONS: Sensory reactivity in allergic asthmatic patients may be increased during prolonged allergen exposure as during the pollen season. This finding suggests that allergic inflammation in the lower and/or upper airways may trigger neurogenic mechanisms of significant clinical importance.  相似文献   
57.
BACKGROUND: The diagnosis of analgesic nephropathy has improved significantly with modern imaging techniques. We reviewed a large portion of the Hungarian dialysis population to obtain additional insight into the problem. METHODS: Twenty-two participating dialysis units enrolled 1400 patients on renal replacement therapy between 1 January 1995 and 1 January 1998. Patients with no known aetiology (n = 284) were interviewed and studied with renal imaging. We assessed the presence of decreased renal mass combined with either bumpy contours, papillary calcification, or both. The subjects studied were interrogated extensively. RESULTS: Our survey suggested analgesic nephropathy in 47 of 1400 patients (3.3%), 3-fold higher than the EDTA database estimate for Hungary. The analgesics most commonly abused were phenacetin-containing mixtures. The driving symptoms were mainly headache and joint pain. Cardiovascular complications were more common than in the rest of the dialysis population, independent of smoking and lipid values (P<0.01). CONCLUSIONS: Phenacetin should be banned. Our study results support the need for longitudinal cohort and case-control studies in Hungary.  相似文献   
58.
The Schwartz Outcomes Scale-10 (SOS-10) is a 10-item scale developed to measure the effectiveness of psychiatric treatments. Using standard methodology, we translated the scale into Czech and examined the psychometric properties of the Czech version. 207 in-patients admitted to Prague Psychiatric Center were included in the study. All patients completed the SOS at admission and discharge. The SOS-10 scale was also administered to 170 persons from the general population. Reliability, validity and sensitivity to treatment change of the Czech SOS-10 were analyzed. The Cronbach’s α coefficient was 0.92. The item-total correlation coefficients varied from 0.56 to 0.82. The SOS-10 correlated well with condition-specific measures including depression (BDI) and anxiety (BAI) and a global self-rated symptom severity scale (CGI). The SOS-10 also had significant correlations with the Health, Basic needs, Relationship, and Leisure time domains of the Czech version of the Subjective Quality of Life Analysis (SQUALA-CZ). The scale discriminated well between patients and controls, with patients scoring significantly lower on all SOS items. The patient sample’s admission and discharge scores were significantly different, indicating that the scale is sensitive to treatment changes. We concluded that the Czech SOS-10 is valid with reliability and factor structure similar to the American language version.  相似文献   
59.
60.
Childhood psoriasis is a disease with manifold clinical presentations which can make the correct diagnosis sometimes difficult. In a female infant, slightly itching, erythematous papules and plaques with discrete scaling spread over large parts of the integument starting from age three months. Histological examination supported the diagnosis of exanthematous infantile psoriasis. Topical treatment with dithranol in petrolatum led to slow clearance of the skin lesions.  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