全文获取类型
收费全文 | 20398篇 |
免费 | 3094篇 |
国内免费 | 165篇 |
学科分类
医药卫生 | 23657篇 |
出版年
2024年 | 88篇 |
2023年 | 481篇 |
2022年 | 212篇 |
2021年 | 471篇 |
2020年 | 642篇 |
2019年 | 374篇 |
2018年 | 792篇 |
2017年 | 765篇 |
2016年 | 879篇 |
2015年 | 1004篇 |
2014年 | 1083篇 |
2013年 | 1543篇 |
2012年 | 1206篇 |
2011年 | 1351篇 |
2010年 | 1012篇 |
2009年 | 1052篇 |
2008年 | 1009篇 |
2007年 | 1105篇 |
2006年 | 1018篇 |
2005年 | 864篇 |
2004年 | 759篇 |
2003年 | 635篇 |
2002年 | 598篇 |
2001年 | 355篇 |
2000年 | 296篇 |
1999年 | 306篇 |
1998年 | 359篇 |
1997年 | 363篇 |
1996年 | 373篇 |
1995年 | 310篇 |
1994年 | 231篇 |
1993年 | 176篇 |
1992年 | 183篇 |
1991年 | 169篇 |
1990年 | 162篇 |
1989年 | 180篇 |
1988年 | 145篇 |
1987年 | 155篇 |
1986年 | 127篇 |
1985年 | 118篇 |
1984年 | 101篇 |
1983年 | 83篇 |
1982年 | 56篇 |
1981年 | 77篇 |
1980年 | 45篇 |
1979年 | 57篇 |
1978年 | 41篇 |
1977年 | 27篇 |
1975年 | 27篇 |
1974年 | 24篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
Zinc sulfate addition to glass-ionomer-based cements: influence on physical and antibacterial properties, zinc and fluoride release. 总被引:5,自引:0,他引:5
Prudencio W R Osinaga Rosa Helena M Grande Rafael Y Ballester Maria Regina L Simionato Célia Regina M Delgado Rodrigues Antonio Muench 《Dental materials》2003,19(3):212-217
OBJECTIVES: The aim of this study is to evaluate the effect of ZnSO(4) addition to a conventional glass ionomer and a resin-modified glass ionomer on solubility, flexural strength, zinc and fluoride (F) release, and Streptococcus mutans growth inhibition. METHODS: 5 or 10% ZnSO(4) was added to Vitremer and Ketac-Fil powders. Solubility test was performed based on ISO 7489. Flexural strength was determined by 3-point bending test based on ISO 4049. Zn release/uptake was determined by atomic emission spectrometry; F release/uptake was measured using a F-specific electrode. Both release measurements were performed for 15 d before and 15 d after recharging. Antibacterial test was conducted according to agar plate methods against S. mutans, by measuring the inhibition halos in 1-h and 15-d specimens. Data were analyzed by ANOVA. RESULTS: Solubility increased with higher ZnSO(4) content, but remained below the ISO 7489 limit. Flexural strength was not affected by ZnSO(4) addition, and Vitremer performed better than Ketac-Fil. The control materials released no zinc. Vitremer with 10% ZnSO(4) released the highest amount of zinc. Fluoride release was similar for Ketac-Fil and Vitremer. In both cases, the highest amounts were released in the first 24 h. The growth inhibition halo of S. mutans was similar for both materials with highest content of ZnSO(4) and occurred only with 1-h specimens. SIGNIFICANCE: Zinc addition decreased microorganisms growth and improved fluoride release, without significantly affecting the materials' flexural strength and solubility. 相似文献
3.
Regina Gershkovich David Sacks Abraham Chlibovsky Sonia Yudaev Asher Korzets 《Nephrology, dialysis, transplantation》2006,21(2):539-540
Case report A 28-year-old female patient was admitted because of painlessmacroscopic haematuria. Past history included severe mentalretardation and nystagmus. At age 17, a computed tomography(CT) scan of the brain showed an absent cerebellar vermis andcerebellar hypoplasia. There was no 相似文献
4.
5.
6.
Relationships Between Arousal-Related Moods and Episodic Tension-Type Headache: A Biopsychological Study 总被引:3,自引:0,他引:3
An exploratory study was conducted examining arousal-related moods and episodic tension-type headache. Twelve subjects meeting International Headache Society criteria for episodic tension-type headache and 12 headache-free controls recorded headache activity and mood eight times daily for 14 consecutive days. Moods were measured using the Activation-Deactivation Adjective Check List, a self-report list that subjectively represents general arousal along two dimensions of Tension and Energy. Headache subjects had higher Tension levels than controls even in the absence of pain, and greater variation in this dimension as well. Within the headache group, Tension during pain-free periods was significantly lower than when experiencing headache, and was correlated with headache activity. The results were taken to support Thayer's (1989) biopsychological model of mood and arousal, and are discussed in terms of the model's heuristic value for general arousal and headache research. 相似文献
7.
Patrick O'Donnell 《Irish journal of medical science》1997,166(1):57-59
The final events of Wolfe Tone’s short and stormy life are fairly common knowledge. He was captured on board the French flagshipHoche when the vessel surrendered to a superior British naval force off Lough Swilly on October 10, 1798. Despite his protests that he was entitled to normal prisoner-of-war treatment, he was brought in irons a month later to Dublin. A court martial was hurriedly convened and he was found guilty of treason on Saturday November 10 and condemned to be hanged two days later. According to the generally accepted version of subsequent events he cut his own throat early on the Monday morning. The assistant surgeon of the 5th Dragoon Guards dressed the wound “ — but only with a view to prolong life until the fatal hour of one o’clock”. This surgeon was Benjamin Lentaigne, a Royalist emigre from France. Despite the pleas of John Philpott Curran, a leading advocate of the day, the military authorities refused to allow any consultation with a civil surgeon. Was this just bloody mindedness or was there an even more sinister reason? Two possibilities come to mind. One was that the wound had been so incompetently treated that a consultant would have been forced to make adverse comments, the other that the throat wound was not due to a cutting injury but, to a bullet fired either deliberately or accidently and a knife or razor was then used to try and camouflage the original trauma. In 1812 Lentaigne published a pamphlet in Latin in which he made reference to an unusual neck would stating that “— the bullet passed through his throat...” There is no direct evidence that the victim was Tone, why did the writer not make this clear? It may be he was reluctant to expose the medico-military inefficiency or callousness or to jeopardise his son’s career. Whatever the true facts, the verdict must remain the Scots one of “Not proven”. 相似文献
8.
9.
Peter Stone MD FRNZCOG FRCOG David Cook FRNZCOG MRCOG John Hutton PhD FRNZCOG FRCOG Gordon Purdie BSc Henry Murray MD FRNZCOG MRCOG Lauren Harcourt MPP BA 《The Australian & New Zealand journal of obstetrics & gynaecology》1995,35(1):32-37
Summary: This is the first report of the largest study of blood pressure measurement in pregnancy in a New Zealand population using standardized definitions and methodology. Over 3,800 women who delivered in an 8-month period in the Wellington region were included in the study. Blood pressure measurement and the presence of oedema and proteinuria were recorded from booking until delivery and in the puerperium. Only 2.7% of women were unable to be contacted after delivery for details on outcomes. The results established normal ranges for blood pressure throughout pregnancy. The data show that Mood pressure greater than 140/90 until 35 weeks' gestation is outside 2 standard deviations at all gestations and justifies using these measurements as the definition of hypertension in pregnancy. The fall in blood pressure in the 2nd trimester was less than 1 mm Ffg per week in both the systolic and diastolic pressures. This fall was smaller than previously recorded in other studies. Gestational hypertension was the commonest blood pressure abnormality occurring in 15.2% of the population. This represented 69% of the pregnant women with a hypertensive disorder. The overall incidence of both gestational hypertension and preeclampsia was 18.5% which is higher than reported in other parts of the world. In this study obesity was significantly associated with hypertensive disorders in pregnancy. An arm circumference of >33 cm, one of the measurements of obesity, was found in 6.8% of the study population. Even after the effect of arm circumference was taken into account, hypertensive disorders were also more common in Pacific Island women. Ankle oedema was significantly associated with the development of both gestational hypertension and preeclampsia but the incidence of oedema was noted in only 11.9% of the subjects. 相似文献
10.