全文获取类型
收费全文 | 1151篇 |
免费 | 63篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 22篇 |
儿科学 | 33篇 |
妇产科学 | 4篇 |
基础医学 | 72篇 |
口腔科学 | 40篇 |
临床医学 | 74篇 |
内科学 | 299篇 |
皮肤病学 | 17篇 |
神经病学 | 95篇 |
特种医学 | 103篇 |
外科学 | 86篇 |
综合类 | 37篇 |
预防医学 | 185篇 |
眼科学 | 11篇 |
药学 | 56篇 |
中国医学 | 1篇 |
肿瘤学 | 86篇 |
出版年
2021年 | 18篇 |
2020年 | 7篇 |
2019年 | 8篇 |
2018年 | 13篇 |
2017年 | 7篇 |
2016年 | 14篇 |
2015年 | 17篇 |
2014年 | 20篇 |
2013年 | 37篇 |
2012年 | 45篇 |
2011年 | 35篇 |
2010年 | 41篇 |
2009年 | 40篇 |
2008年 | 57篇 |
2007年 | 55篇 |
2006年 | 58篇 |
2005年 | 40篇 |
2004年 | 42篇 |
2003年 | 46篇 |
2002年 | 50篇 |
2001年 | 47篇 |
2000年 | 50篇 |
1999年 | 45篇 |
1998年 | 38篇 |
1997年 | 28篇 |
1996年 | 25篇 |
1995年 | 16篇 |
1994年 | 25篇 |
1993年 | 27篇 |
1992年 | 30篇 |
1991年 | 19篇 |
1990年 | 14篇 |
1989年 | 23篇 |
1988年 | 24篇 |
1987年 | 21篇 |
1986年 | 19篇 |
1985年 | 16篇 |
1984年 | 15篇 |
1983年 | 11篇 |
1982年 | 9篇 |
1981年 | 12篇 |
1980年 | 12篇 |
1978年 | 4篇 |
1977年 | 5篇 |
1976年 | 9篇 |
1975年 | 3篇 |
1974年 | 5篇 |
1969年 | 2篇 |
1968年 | 2篇 |
1966年 | 2篇 |
排序方式: 共有1221条查询结果,搜索用时 15 毫秒
991.
992.
AL Pozniak RF Miller MCI Lipman AR Freedman LP Ormerod MA Johnson S Collins SB Lucas 《HIV medicine》2005,6(S2):62-83
993.
Aaron R Folsom James M Peacock Eric Boerwinkle 《Cancer epidemiology, biomarkers & prevention》2007,16(11):2455-2458
Some prospective epidemiologic studies have suggested that a low plasma cholesterol level may be associated with increased risk of cancer. Certain sequence variants in the proprotein convertase subtilisin/kexin type 9 serine protease gene (PCSK9) are associated with lifelong low total and LDL cholesterol. We therefore analyzed the association of PCSK9 variation with incidence of cancer between 1987 and 2000 in a prospective study (n=13,250). The frequency of the PCSK9 variants studied was 2.4% in blacks and 3.2% in whites. Neither was associated with increased cancer incidence: age- and sex-adjusted hazard ratios were 0.66 [95% confidence interval (95% CI), 0.31-1.39] in blacks and 0.77 (95% CI, 0.54-1.09) in whites. Low baseline total or LDL cholesterol levels in 1987 to 1989 were also not statistically significantly associated with incident cancer: multivariable-adjusted hazard ratios for the lowest compared with the highest quartiles of LDL cholesterol were 1.05 (95% CI, 0.78-1.40) in blacks and 1.16 (95% CI, 0.99-1.36) in whites. These data suggest that a lifelong low cholesterol concentration, as reflected by these PCSK9 variants, does not increase risk of cancer. 相似文献
994.
Celine M Vachon Pamela J Mink Carol A Janney Thomas A Sellers James R Cerhan Lynn Hartmann Aaron R Folsom 《Epidemiology (Cambridge, Mass.)》2002,13(1):66-71
Although parity is associated with a decreased risk of ovarian cancer in the general population, this association among women with a family history is less clear. We examined this question in a prospective cohort of 31,377 Iowa women 55-69 years of age at baseline. Relative risks (RRs) and 95% confidence intervals (CIs) were estimated through Cox regression. We identified 181 incident epithelial ovarian cancers through 13 years of follow-up. At baseline, 14% of the women reported breast or ovarian cancer in a first-degree relative, and an additional 12% reported a family history in a second-degree relative. Among women without a family history of breast or ovarian cancer in a first-degree relative, nulliparous women were at slightly increased risk of ovarian cancer (RR = 1.4, 95% CI = 0.9-2.4) compared with parous women, whereas among women with a family history, nulliparous women were at a much higher risk (RR = 2.7, 95% CI = 1.1-6.6) than parous women. Similar results were seen when family history included first- or second-degree relatives with breast or ovarian cancer or a first- or second-degree relative with ovarian cancer only. Nulliparity may be more strongly associated with an increased risk of ovarian cancer among women with a family history of breast or ovarian cancer, compared with women who do not have a family history of those cancers. 相似文献
995.
S Seidenari† F Giusti† G Pellacani† AR Antelmi‡ C Foti‡ D Bonamonte‡ F Ayala§ G Balato§ A Cristaudo¶ L Stingeni†† P Lisi†† 《Journal of the European Academy of Dermatology and Venereology》2005,19(4):449-454
BACKGROUND: The 1- and the 2-euro coins consist of nickel alloys, which release nickel. The nickel released by far exceeds the amount allowed by the European Union Nickel Directive referring to products intended to come into direct and prolonged contact with the skin. As there is only temporary contact with the skin, the clinical relevance of nickel-containing coins with regard to nickel dermatitis is a matter of debate, although there is evidence that the nickel released from the coins affects some nickel-sensitive subjects through occupational exposure. OBJECTIVES: Our aim was to study skin reactivity to euro coins, and to correlate the frequency and intensity of coin patch test responses to sensitization thresholds to nickel. PATIENTS AND METHODS: Sixty-four nickel-sensitized and 30 non-nickel-sensitized subjects were patch tested with serial dilutions of nickel sulfate (5, 1, 0.5, 0.1, 0.05, 0.01 and 0.005% in distilled water) and with coins. Italian coins (500, 200, 100 and 50 lira) and euro coins (2 and 1 euros, 20 and 5 euro cents) were used for patch testing and compared. RESULTS: The application of 1- and 2-euro coins to the skin induced eczematous reactions, being more frequent and intense in comparison with those provoked by other coins. A correlation between intensity of responses to coin patch tests and sensitization threshold to nickel was observed. Patients with the strongest reactions to 1- and 2-euro coins showed positive responses to the lowest nickel concentrations. CONCLUSIONS: The nickel content in euro coins represents a possible health hazard, especially for highly nickel-sensitive subjects. We recommend that nickel sulfate patch tests should be performed at different concentrations to determine sensitization thresholds at least in individuals with occupational exposure to coins. 相似文献
996.
Platelet and plasma levels of glutamate and glutamine in migraine with and without aura 总被引:1,自引:0,他引:1
AR Cananzi G D'Andrea F Perini F Zamberlan KMA Welch 《Cephalalgia : an international journal of headache》1995,15(2):132-135
We evaluated plasma and platelet glutamate and glutamine levels in migraine with and without aura during headache-free periods and compared the results with those of normal controls. The plasma and platelet levels of glutamine in migraine with and without aura were normal. Migraine without aura patients had higher glutamate levels in plasma, and normal platelet levels. In migraine with aura patients, glutamate levels were high in platelets, but not in plasma. This suggests different profiles of excitatory amino acid metabolism in migraine with and without aura. 相似文献
997.
The use of prophylactic fluconazole in immunocompetent high-risk surgical patients: a meta-analysis 总被引:1,自引:1,他引:1
下载免费PDF全文
![点击此处可从《Critical care (London, England)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Introduction
High-risk surgical patients are at increased risk of fungal infections and candidaemia. Evidence from observational and small randomised controlled studies suggests that prophylactic fluconazole may be effective in reducing fungal infection and mortality. We evaluated the effects of prophylactic fluconazole on the incidence of candidaemia and hospital mortality in immunocompetent high-risk surgical patients. 相似文献998.
WVBS Ramalingam D Chikara G Rajagopal AVSM AR Mehta S Sarkar 《Medical Journal Armed Forces India》2007,63(1):15-18
Background
Stage III and IV cancers of larynx and hypopharynx often require total laryngectomy which leaves the patient with severe communication handicap. In such laryngectomised patients tracheo-esophageal puncture is the best way for voice rehabilitation using either Blom-Singer® prosthesis or Provox® indwelling valve.Methods
A prospective comparative study of Blom-Singer® prosthesis and Provox® indwelling valves placed in Tracheo-esophageal Punctures (TEP) for voice rehabilitation following total laryngectomy was carried out at the Tata Memorial Hospital, Mumbai and Malignant Diseases Treatment Centre of Armed Forces, to assess their efficacy. This report comprises of our experience in 41 (39 males and two females) laryngtectomees who underwent TEP of which 15 patients were fitted with low pressure Blom-Singer® prostheses and 26 with Provox® indwelling prostheses.Results
Prostheses related problems like granuloma formation, leakage, candidal growth over the valves and prosthetic decay were significantly less in the patients fitted with Provox® prosthesis. Dislodgement of prosthesis with closure of the tract or persistent fistula formation and creation of false passage, while reinsertion were problems encountered in the Blom-Singer group. After three months, speech assessment revealed a better quality of voice production and patient compliance in maintaining the prosthesis in the case of Provox® indwelling valve.Conclusion
In Indian scenario where illitracy amongst the patients hinders in maintainence of Blom-Singer® prosthesis, Provox® indwelling value is an appropriate choice for voice rehabilitation.Key Words: Tracheo-esophageal puncture (TEP), Blom-Singer® prosthesis, Provox® Valve 相似文献999.
1000.
F Facchinetti I Neri E Martignoni L Fioroni G Nappi AR Genazzani 《Cephalalgia : an international journal of headache》1993,13(6):422-425
To investigate the comorbidity of premenstrual syndrome (PMS) and menstrual migraine, the Menstrual Distress Questionnaire (MDQ) was prospectively administered for two consecutive menstrual cycles to 22 patients with menstrual migraine, 12 cases with migraine without aura and 15 patients with PMS. MDQ scores varied throughout the menstrual cycle in each patient group, the wider changes being shown by patients with PMS. Fourteen menstrual migraine patients and 4 migraine without aura patients achieved diagnostic criteria for PMS over two menstrual cycles. In these patients MDQ scores did not differ from PMS sufferers at any stage of the menstrual cycle. The premenstrual increase of each cluster of PMS symptoms was identical in menstrual migraine and PMS subjects with the exception of negative affect. We suggest that PMS symptoms should be taken into account in the IHS diagnostic criteria for menstrual migraine. 相似文献