全文获取类型
收费全文 | 18214篇 |
免费 | 1029篇 |
国内免费 | 81篇 |
专业分类
耳鼻咽喉 | 281篇 |
儿科学 | 339篇 |
妇产科学 | 322篇 |
基础医学 | 2664篇 |
口腔科学 | 1971篇 |
临床医学 | 1449篇 |
内科学 | 3707篇 |
皮肤病学 | 492篇 |
神经病学 | 1374篇 |
特种医学 | 369篇 |
外科学 | 1939篇 |
综合类 | 51篇 |
一般理论 | 5篇 |
预防医学 | 2071篇 |
眼科学 | 195篇 |
药学 | 1370篇 |
中国医学 | 186篇 |
肿瘤学 | 539篇 |
出版年
2023年 | 181篇 |
2022年 | 481篇 |
2021年 | 744篇 |
2020年 | 517篇 |
2019年 | 664篇 |
2018年 | 782篇 |
2017年 | 610篇 |
2016年 | 599篇 |
2015年 | 766篇 |
2014年 | 916篇 |
2013年 | 1039篇 |
2012年 | 1580篇 |
2011年 | 1772篇 |
2010年 | 901篇 |
2009年 | 661篇 |
2008年 | 1066篇 |
2007年 | 1082篇 |
2006年 | 870篇 |
2005年 | 745篇 |
2004年 | 614篇 |
2003年 | 511篇 |
2002年 | 424篇 |
2001年 | 267篇 |
2000年 | 251篇 |
1999年 | 192篇 |
1998年 | 68篇 |
1997年 | 53篇 |
1996年 | 42篇 |
1995年 | 35篇 |
1994年 | 49篇 |
1993年 | 28篇 |
1992年 | 93篇 |
1991年 | 88篇 |
1990年 | 61篇 |
1989年 | 57篇 |
1988年 | 50篇 |
1987年 | 34篇 |
1986年 | 40篇 |
1985年 | 36篇 |
1984年 | 24篇 |
1983年 | 31篇 |
1980年 | 27篇 |
1979年 | 30篇 |
1977年 | 16篇 |
1973年 | 20篇 |
1971年 | 14篇 |
1970年 | 16篇 |
1969年 | 15篇 |
1968年 | 32篇 |
1966年 | 15篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Stefanini ML Colli C Lerner BR Lei DL Chaves SP Di Pietro MS Oliveira AA Szarfarc SC 《Cadernos de saúde pública / Ministério da Saúde, Funda??o Oswaldo Cruz, Escola Nacional de Saúde Pública》1995,11(3):439-447
The authors studied a sample of students entering the first grade in the Osasco public school system in order to determine both the prevalence of anemia and nutritional status. Osasco is part of the Greater S o Paulo Metropolitan Area. Diagnosis of anemia was made through the hemoglobin concentration of blood from digital puncture. World Health Organization (WHO) levels were used to define anemia. Nutritional Status assessment. was made through weight/age and height/age indices, using Z score distribution and the National Center for Health Statistics (NCHS) reference levels. Prevalence of anemia was 51%. Prevalence levels varied according to the schools' geographic location: 56.9% in peripheral neighborhoods and 41.7% in central areas. Children with illiterate parents had a higher prevalence of this condition. Risk of anemia was higher for children who were over eight years of age when entering the first grade. Acute malnutrition was not found. Prevalence was higher than expected and points to the urgent need to establish an anemia control program for schoolchildren in this population. 相似文献
62.
63.
Oliveira MA Bermudez JA Souza AC 《Cadernos de saúde pública / Ministério da Saúde, Funda??o Oswaldo Cruz, Escola Nacional de Saúde Pública》1999,15(1):99-112
This paper discusses issues related to the regulation and rational use of thalidomide in Brazil, by means of a historical approach comprising three different stages. The first part is a historical review of the controversial drug since it was first synthesized, then marketed and subsequently banned during the 1950s and 60s, until the present, when an apparently irreversible process of rehabilitating the drug is under way. Brazilian experience with the use of thalidomide is described, emphasizing legal, political, and institutional work led by two social movements, the Brazilian Association of People with Thalidomide Syndrome (ABPST) and the Movement for Reintegration of People with Hansen's Disease (Morhan). The article describes the results and analyzes an active search of new cases in what is a second generation of thalidomide syndrome in Brazil. Finally, based on clinical and scientific evidence of thalidomide's therapeutic efficacy, the growth of social movements struggling both for and against authorization of the drug, and a restrictive regulation proposed by the Ministry of Health, the article discusses the implementation of policies for the regulation and rational use of thalidomide in Brazil. 相似文献
64.
Oliveira EA Diniz JS Cabral AC Leite HV Colosimo EA Oliveira RB Vilasboas AS 《Pediatric nephrology (Berlin, Germany)》1999,13(9):859-864
With the increasing use of obstetric echography fetal hydronephrosis has been reported more frequently. The purpose of this
study was to identify prognostic factors associated with adverse outcome, such as renal failure and death, in fetal hydronephrosis.
One hundred and forty-eight children with fetal hydronephrosis were admitted, submitted to a systematic protocol, and prospectively
followed. Prognostic factors associated with fetal echography and clinical and laboratory findings on admission were studied.
The median follow-up was 39 months. The analysis was conducted in two steps. In a univariate analysis, variables associated
with adverse outcome were identified by the Kaplan-Meier method. The variables that were significantly associated with adverse
outcome were then included in a multivariate analysis. This analysis, using the multivariate Cox’s model, was performed to
identify variables that were independently associated with a worse prognosis. Only variables that remained independently associated
with adverse outcome were included in the final model. After final adjustment by Cox’s multivariate model, three variables
were identified as independent predictors of adverse outcome: oligohydramnios, prematurity, and glomerular filtration rate
lower than 20 ml/min. Thus, in the presence of oligohydramnios, prematurity, and abnormal renal function, the medical team
must plan appropriate follow-up for infants at health centers prepared to investigate and treat uropathies in newborns.
Received: 24 August 1998 / Revised: 7 December 1998 / Accepted: 11 December 1998 相似文献
65.
Biernat H Ellias SA Wermuth L Cleary D de Oliveira Santos EC Jørgensen PJ Feldman RG Grandjean P 《Neurotoxicology》1999,20(6):945-952
A new portable tremometer allows determination of tremor intensities at different tremor frequencies. Based on past studies, two tremor frequency windows of similar size were chosen at 3.0-6.5 Hz and 6.6-10.0 Hz to reflect major tremor intensities in Parkinson's disease and mercury vapor poisoning, respectively. In 81 healthy controls, total tremor intensity was higher for the preferred hand and depended on age. Ten patients treated for Parkinson's disease showed substantially increased tremor intensity, especially within the low-frequency window. This pattern was also apparent in 14 patients with de novo Parkinson's disease whose overall tremor intensity was only mildly elevated. In contrast, ten patients with essential tremor had peak frequencies in both windows, and some patients had increased tremor on one side only. Sixty-three Brazilian gold traders exposed to mercury vapor showed increased tremor predominantly in the high-frequency window. Three of the gold traders had a narrower tremor peak at frequencies of 7-8 Hz. While the urine-mercury concentration was significantly associated with the current number of burning sessions per week, it did not correlate with tremor intensities. However, eight traders had a urinary mercury excretion level above 50 microg and at the same time a greatly increased average tremor intensity within the high-frequency window. These patterns were statistically significant for relative tremor intensities, but were less clear when total intensities were used. These observations suggest that the relative distribution of tremor intensities in specific frequency bands may be a valuable supplement to current diagnostic methods for subjects with mercury vapor exposure. 相似文献
66.
Nakamura-Palacios EM de Oliveira RW Gomes CF 《Progress in neuro-psychopharmacology & biological psychiatry》1999,23(8):1369-1388
1. Effects of diazepam (DZP) or haloperidol (HAL) on convulsions and behavioral responses (locomotion, circling, spying and head shaking) induced by bilateral electrical stimulation in the medial prefrontal cortex (mPFC) were examined. 2. Male Wistar rats were electrically stimulated (ten 30-sec trains, 60 Hz, 80-100 microA) bilaterally in the mPFC and their behavior was simultaneously observed in an open field in daily session. 3. DZP and HAL dose-response curves (0, 0.5, 1.25, 2.5 and 5 mg/kg, i.p., 30 min before electrical stimulation session) were determined after a baseline of behavioral responses was established. 4. DZP dose-dependently decreased head shaking and convulsions, had no effect in circling and spying behaviors, and increased locomotion except at the highest dose. HAL reduced locomotion, circling and spying behaviors in a dose-dependent manner, but did not affect convulsions or head shaking. 5. These results demonstrated that convulsion and behavioral responses induced by electrical activation of the mPFC were modified by DZP or HAL. Therefore, the mPFC is involved in the mediation of neural and/or behavioral activity that may be implicated in some central effects of psychoactive drugs. 相似文献
67.
African horse sickness (AHS) was diagnosed for the first time in southern Portugal in autumn 1989, following outbreaks in Spain. AHS virus presence was confirmed by virus isolation and serotyping. An eradication campaign with four sanitary zones was set up by Central Veterinary Services in close collaboration with private organizations. Vaccination began on 6 October. In February 1990, vaccination was extended to all Portuguese equines (170000 animals). There were 137 outbreaks on 104 farms: 206 of the equidae present died (16%) or were slaughtered (14%); 81.5% were horses, 10.7% were donkeys and 7.8% were mules. Clinical AHS occurred more frequently in horses than donkeys and mules. In the vaccinated population, 82 animals (62.2% horses and 37.8% mules and donkeys), died or were slaughtered due to suspected or confirmed AHS. One year after ending vaccination, December 1991, Portugal was declared free of AHS. Cost of eradication was US$1955513 (US$11.5/Portuguese equine). 相似文献
68.
A quartz crystal microbalance has been used to check the purity of glycerol. The experimental procedure involves no derivatization or other preliminary step except determination of water content. The protocol consists of the direct reading of the frequency of a quartz crystal with one face in contact with an aqueous solution of the glycerol to be tested. The method is inexpensive, simple, rapid, and highly sensitive; diethylene glycol contamination at the 3.61% level could be detected. 相似文献
69.
Grossamide, and N-trans-caffeoyltyramine, were isolated for the first time from the seeds of Annona crassiflora Mart, and in the Annonaceae family. 相似文献
70.
Six children received etoposide as the single agent for treatment of Langerhans cell histiocytosis (LCH; histiocytosis X). Five were less than 2 years old at diagnosis. All had multiorgan involvement; one had liver and pulmonary dysfunction. Two infants also had clinical signs of immune deficiency. Complete response was observed in five. There was no major toxicity. Although three of four evaluable patients relapsed, the drug was considered useful in moving the children from a symptomatic to an asymptomatic clinical status. Etoposide may become a "first-line" drug in the treatment of systemic LCH, especially when the side effects of steroid therapy are considered unacceptable. 相似文献