全文获取类型
收费全文 | 601篇 |
免费 | 33篇 |
国内免费 | 10篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 30篇 |
妇产科学 | 6篇 |
基础医学 | 56篇 |
口腔科学 | 11篇 |
临床医学 | 47篇 |
内科学 | 145篇 |
皮肤病学 | 11篇 |
神经病学 | 21篇 |
特种医学 | 157篇 |
外科学 | 41篇 |
综合类 | 32篇 |
预防医学 | 12篇 |
眼科学 | 4篇 |
药学 | 47篇 |
中国医学 | 6篇 |
肿瘤学 | 16篇 |
出版年
2023年 | 7篇 |
2022年 | 2篇 |
2021年 | 5篇 |
2020年 | 2篇 |
2019年 | 8篇 |
2018年 | 6篇 |
2016年 | 22篇 |
2015年 | 47篇 |
2014年 | 17篇 |
2013年 | 19篇 |
2012年 | 14篇 |
2011年 | 19篇 |
2010年 | 30篇 |
2009年 | 27篇 |
2008年 | 20篇 |
2007年 | 9篇 |
2006年 | 12篇 |
2005年 | 17篇 |
2004年 | 7篇 |
2003年 | 7篇 |
2002年 | 7篇 |
2001年 | 9篇 |
2000年 | 6篇 |
1999年 | 9篇 |
1998年 | 22篇 |
1997年 | 42篇 |
1996年 | 33篇 |
1995年 | 27篇 |
1994年 | 22篇 |
1993年 | 19篇 |
1992年 | 3篇 |
1991年 | 7篇 |
1990年 | 11篇 |
1989年 | 22篇 |
1988年 | 18篇 |
1987年 | 10篇 |
1986年 | 12篇 |
1985年 | 7篇 |
1984年 | 8篇 |
1983年 | 7篇 |
1982年 | 9篇 |
1981年 | 7篇 |
1980年 | 7篇 |
1978年 | 3篇 |
1977年 | 5篇 |
1976年 | 6篇 |
1968年 | 1篇 |
1955年 | 1篇 |
1952年 | 1篇 |
1948年 | 1篇 |
排序方式: 共有644条查询结果,搜索用时 15 毫秒
51.
KM FOCK JY KANG HS NG TM NG KA GWEE CC LIM 《Journal of gastroenterology and hepatology》1995,10(4):379-382
Roxatidine acetate, a new H2 receptor antagonist, was compared with ranitidine in the treatment of duodenal ulcers in a double-blind multicentre study. Eighty-four patients with endoscopically proven duodenal ulcer were randomized to receive 150 mg roxatidine acetate or 300 mg ranitidine at bedtime. Repeat endoscopy was performed after 4 weeks (25–33 days) and if the ulcer had not healed, another endoscopy was performed after a further 4 weeks of treatment. Using per protocol analysis 73.6% of ulcers treated with roxatidine healed at 4 weeks compared to 72.2% of ulcers treated with ranitidine (P=NS). The healing rates at 8 weeks were 92% with roxatidine and 83.3% with ranitidine (P=NS). Using equivalence tests, the healing rate of roxatidine was found to be equivalent to that of ranitidine within a 20% region. Roxatidine users took significantly less antacids than ranitidine users (P < 0.05). There were no significant adverse effects due to roxatidine or ranitidine. Roxatidine is a safe effective drug in the treatment of duodenal ulcers with a healing rate comparable to that of ranitidine. 相似文献
52.
53.
54.
OBJECTIVE:
Inflammation plays an important role in the development of chronic lung disease (CLD), which has become a major cause of morbidity in surviving infants less than 1250 g at birth. The authors hypothesized that the progression of this inflammation and, therefore, the establishment of CLD would be decreased with the use of early prophylactic inhaled corticosteroids. Short, and long term respiratory and neurodevelopmental outcomes were also examined.DESIGN:
A double-blind, randomized placebo controlled trial.SETTING:
Level-III neonatal intensive care unit.POPULATION STUDIED:
Sixty infants less than 1250 g at birth, diagnosed with respiratory distress syndrome and requiring ventilatory support at 72 h of age were enrolled in the study.INTERVENTION:
Infants enrolled received either placebo or beclomethasone diproprionate by a metered dose inhaler, which was used in-line with the ventilator circuit while the infant was ventilated and then via a spacer until 28 days of age.RESULTS:
Thirty infants were given beclomethasone and 30 were given placebo. There were two deaths in each group. Among the surviving infants, the frequency of moderate-to-severe CLD was 17% in each study group. Mean time to extubation was not different for beclomethasone compared with placebo at 16.4 and 12.5 days (P=0.12), respectively. The requirement for intravenous corticosteroids was lower in the beclomethasone-treated group (RR 0.67, 95% CI 0.43 to 1.04), although this difference was not statistically significant. The incidence of growth failure, infection and intraventricular hemmorhage did not differ between the two groups. Long term outcomes were not different with respect to the incidence of respiratory re-admissions, cerebral palsy, developmental delay, blindness or deafness.CONCLUSIONS:
Early treatment with inhaled beclomethasone diproprionate did not reduce the incidence of CLD or decrease the duration of mechanical ventilation. The decrease in intravenous corticosteroid use was not statistically significant. Long term outcome was not affected. 相似文献55.
Ødegård RA Vatten LJ Nilsen ST Salvesen KA Vefring H Austgulen R 《Obstetrics and gynecology》2001,98(2):289-294
OBJECTIVE: To study the association between umbilical plasma levels of interleukin-6 (IL-6) in relation to fetal growth in subgroups of preeclampsia, and in control pregnancies. METHODS: Umbilical cord plasma was collected from 12,804 consecutive births. A total of 271 singleton cases of preeclampsia were identified, and classified as mild or severe, and as disease with early or late onset. As controls, 611 singleton pregnancies without preeclampsia were selected, and the ratio between observed and expected birth weight was used as a measure of fetal growth. In the analysis, we also included maternal smoking during pregnancy. Umbilical cord plasma IL-6 concentration was measured with an IL-6 bioassay. Comparing controls with subgroups of preeclampsia (severe and early onset), this study had a statistical power of 90% to detect a difference in cord IL-6 of 10 pg/mL. RESULTS: In severe preeclampsia, cord plasma IL-6 concentration was lower than among controls (P <.001), and there was a sharp decrease in cord plasma IL-6 with decreasing birth weight ratio (P trend <.001). By further dividing the preeclampsia group into early or late onset, the strong association between low IL-6 levels and low birth weight ratio appeared to be present mainly in early-onset disease. These results were not confounded by maternal smoking. CONCLUSION: Restricted fetal growth related to preeclampsia is associated with reduced umbilical cord plasma IL-6 concentration in cases with early-onset disease. In these cases, fetal growth restriction could be mediated by impaired trophoblast function. 相似文献
56.
57.
ABSTRACT. Milt7eacute;nyi, M., Pohlandt, F., Bóka, G. and Kun, E. (2nd Department of Paediatrics, Semmelweis University, Medical School, Budapest, Hungary, and the Section of Neonatology, Centre of Paediatrics, University of Ulm, Federal Republic of Germany). Tubular proteinuria after perinatal hypoxia. Acta Paediatr Scand, 70:399, 1981.–Urinary total protein (UTP) and urinary protein pattern have been studied in 23 newborn infants with Apgar scores ±S3 at one minute or acidosis (pH ±7.15) on the first day. On the first and second day UTP excretion was increased in 13 out of 18 patients. At this time the excretion of low molecular weight microproteins (T-4 and T-5) was elevated in 12 patients without increased plasma urea concentration in any case. The increased excretion of the smallest microproteins T-4/T-5 is an early sign of an impaired tubular function. 相似文献
58.
Shin JH; Oestmann J; Hall D; Cardenosa G; McCarthy KA; Mrose HE; Pile- Spellman E; Rubens JR; Greene RE 《Radiology》1989,172(2):399-401
The authors compared low-dose (32% of standard exposure) storage phosphor digital imaging (system resolution: 0.2-mm pixels, 10 bits) with isovoltage 75-kVp conventional radiography (standard exposure) in the detection of subtle simulated gastric abnormalities by using air contrast barium studies. Subtle simulated abnormalities (3-7-mm polyps, 4-15-mm ulcer craters, 4-11-mm-diameter edema, and 11-12-mm linear ulcers) were produced in resected canine stomachs. Receiver operating characteristic analysis of 1,800 observations by six readers indicated that the digital images with and without high-frequency edge enhancement were equivalent to conventional radiographs (mean receiver operating characteristic areas [+/- standard deviation]: 0.76 +/- 0.06, 0.78 +/- 0.04, and 0.77 +/- 0.04, respectively). The accuracy of the diagnosis was equivalent for all three modalities. The following mean accuracies of negative and positive responses, respectively, for unenhanced digital, edge-enhanced digital, and conventional images were determined: 0.71 +/- 0.05 and 0.41 +/- 0.07, 0.71 +/- 0.04 and 0.51 +/- 0.09, and 0.68 +/- 0.04 and 0.43 +/- 0.05. It was concluded that low-dose storage phosphor air-contrast barium studies were equivalent to conventional radiography in the detection of subtle gastric abnormalities. 相似文献
59.
60.