全文获取类型
收费全文 | 4601篇 |
免费 | 311篇 |
国内免费 | 4篇 |
专业分类
耳鼻咽喉 | 86篇 |
儿科学 | 125篇 |
妇产科学 | 115篇 |
基础医学 | 478篇 |
口腔科学 | 611篇 |
临床医学 | 237篇 |
内科学 | 955篇 |
皮肤病学 | 112篇 |
神经病学 | 300篇 |
特种医学 | 74篇 |
外科学 | 655篇 |
综合类 | 10篇 |
一般理论 | 2篇 |
预防医学 | 456篇 |
眼科学 | 331篇 |
药学 | 212篇 |
中国医学 | 64篇 |
肿瘤学 | 93篇 |
出版年
2023年 | 14篇 |
2022年 | 69篇 |
2021年 | 106篇 |
2020年 | 87篇 |
2019年 | 111篇 |
2018年 | 165篇 |
2017年 | 140篇 |
2016年 | 132篇 |
2015年 | 146篇 |
2014年 | 219篇 |
2013年 | 241篇 |
2012年 | 284篇 |
2011年 | 336篇 |
2010年 | 181篇 |
2009年 | 179篇 |
2008年 | 264篇 |
2007年 | 296篇 |
2006年 | 273篇 |
2005年 | 252篇 |
2004年 | 203篇 |
2003年 | 151篇 |
2002年 | 156篇 |
2001年 | 123篇 |
2000年 | 110篇 |
1999年 | 69篇 |
1998年 | 48篇 |
1997年 | 29篇 |
1996年 | 24篇 |
1995年 | 17篇 |
1994年 | 13篇 |
1993年 | 17篇 |
1992年 | 29篇 |
1991年 | 47篇 |
1990年 | 24篇 |
1989年 | 17篇 |
1988年 | 19篇 |
1987年 | 19篇 |
1986年 | 24篇 |
1985年 | 24篇 |
1984年 | 17篇 |
1983年 | 14篇 |
1979年 | 14篇 |
1977年 | 11篇 |
1971年 | 14篇 |
1970年 | 22篇 |
1969年 | 27篇 |
1968年 | 15篇 |
1967年 | 20篇 |
1966年 | 14篇 |
1965年 | 12篇 |
排序方式: 共有4916条查询结果,搜索用时 15 毫秒
21.
Rosário Filho NA 《Jornal de pediatria》1996,72(5):281-286
Inhaled bronchodilators are used in acute asthma for relief of airway obstruction. Continuous monotherapy with beta 2 adrenergic can increase hyperresponsiveness because these drugs do not control inflammation. Asthma mortality and morbidity have been related to an increased beta 2-agonists use. Epidemiologic data however do not show a cause/effect relationship. Until controversies are cleared on, beta 2-agonists should be used for relieving acute asthma attacks, for preventing exercise-induced bronchospasm and eventually on an as needed basis. Long acting beta 2-agonists can be effective in moderate/severe asthma. Daily short acting beta 2 use by inhalation, a partial clinical response and its overuse in acute asthma suggest the need for antiinflammatory treatment. 相似文献
22.
B B Lorenzetti G E Souza S J Sarti D Santos Filho S H Ferreira 《Journal of ethnopharmacology》1991,34(1):43-48
Oral administration of an infusion of lemongrass (Cymbopogon citratus) fresh leaves to rats produced a dose-dependent analgesia for the hyperalgesia induced by subplantar injections of either carrageenin or prostaglandin E2, but did not affect that induced by dibutyryl cyclic AMP. These results indicate a peripheral site of action which was confirmed with the essential oil obtained by steam distillation of the leaves. Silica gel column fractionation of the essential oil allowed the identification of myrcene as the major analgesic component in the oil. Identification of the components was made by thin-layer chromatography and checked by mass spectrometry. The peripheral analgesic effect of myrcene was confirmed by testing a standard commercial preparation on the hyperalgesia induced by prostaglandin in the rat paw test and upon the contortions induced by intraperitoneal injections of iloprost in mice. In contrast to the central analgesic effect of morphine, myrcene did not cause tolerance on repeated injection in rats. This analgesic activity supports the use of lemongrass tea as a "sedative" in folk medicine. Terpenes such as myrcene may constitute a lead for the development of new peripheral analgesics with a profile of action different from that of the aspirin-like drugs. 相似文献
23.
Rapid maxillary expansion in the primary and mixed dentitions: a cephalometric evaluation 总被引:9,自引:3,他引:6
O G da Silva Filho M C Boas L Capelozza Filho 《American journal of orthodontics and dentofacial orthopedics》1991,100(2):171-179
The present study evaluated the skeletal alterations induced by rapid maxillary expansion procedures in 30 patients in the primary and mixed dentitions. The results were obtained with the use of lateral cephalometrics before and immediately after the active phase of expansion. The time span between these two cephalometric films ranged from 14 to 21 days; therefore the "growth factor" was not considered. Based on the differences in the cephalometric measurements studied on the first and second tracings, it seems that anterior displacement of the maxilla with significant changes in the SNA angle should not be expected, although point B was repositioned more posteriorly (SNB) because of the mandibular downward and backward rotation, with subsequent increase of the inclination of the mandibular plane. The alterations in the A-P position of the mandible was reflected in the increase of ANB and NAP angles. The maxilla always dislocates downward, displaying a downward and backward rotation in the palatine plane, significantly altering the following measurements: N-ANS, PNS-PNS', A-A', SN.PP. The anchoring molars also follow the downward maxillary displacement (M-M') and, as a direct consequence of the vertical displacement of the maxilla and upper molars (N-ANS, A-A', ANS-Me, N-Me, PNS-PNS'), the facial heights increase. 相似文献
24.
We are concerned in this paper with learning classification procedures from known cases. More precisely, we provide a diagnostic model that discriminate between cerebellum-pontine angle (CPA) tumors and otorhinolaryngological (ENT) disorders. Usually, in order to distinguish between CPA tumors and ENT disorders one must perform clinical-neurological examination together with expensive radiological imagery (CT and MRI). The proposed model was obtained through artificial intelligence methods and presented a good accuracy level (88.4%) when tested against new cases, considering only clinical examination without radiological imagery results. 相似文献
25.
Fernanda B Nunes Cássio M Graziottin José Carlos F Alves Filho Adroaldo Lunardelli Melissa G S Pires Paulo H W?chter Jarbas R De Oliveira 《Pharmacological research》2003,47(1):35-41
Tissue lesion mechanisms provoked by sepsis include the infectious process, inflammation, and cellular energy deficit. We chose to test fructose-1,6-bisphosphate (FBP) because of its possible anti-inflammatory and antimicrobial actions. Wistar rats were used and divided into three experimental groups: a control group (n=10), in which a capsule was introduced into the peritoneum of the animals; a septic group (n=10), in which a capsule containing non-sterile fecal matter was introduced together with Escherichia coli (1.5 x 10(9)CFU); and a septic group treated with FBP 500 mg/kg (n=10). The blood cell tests revealed that levels of leukocytes increased significantly in the septic group when compared to both the septic group treated with FBP and the control group. The blood cultures were 100% positive in both the septic group and the septic group treated with bisphosphorylated sugar. The antibiogram only revealed an inhibitory halo in the case of the antibiotic ampicillin, there was no such indication for FBP. The anti-inflammatory power of FBP remained at 60% for 5 h in the rats that received the carrageenan injection. What is more, the sugar reduced the levels of ionic calcium in relation to the control group. This data proves the validity of using FBP in the treatment of sepsis, possibly due to its anti-inflammatory rather than antimicrobial action. 相似文献
26.
Acute effects on systemic circulation after intratracheal instillation of Curosurf or Survanta in surfactant-depleted newborn piglets 总被引:2,自引:0,他引:2
A Moen X-Q Yu R Almaas T Curstedt OD Saugstad 《Acta paediatrica (Oslo, Norway : 1992)》1998,87(3):297-303
Systemic vasodilatation in surfactant-depleted newborn piglets is induced by 200 mg/kg of modified porcine lung surfactant (Curosurf™). The aim of this investigation was to study whether this effect is dependent on dose and could further be induced by instillation of a bovine surfactant preparation (Survanta™). Twenty-two 3–5-d old piglets were subjected to repeated saline lung lavage and then randomized to one of three groups. Instillation of either Curosurf 100 mg/kg ( n = 8), Survanta 100 mg/kg ( n = 7) or Curosurf 200 mg/kg ( n = 7) was performed through the endotracheal tube. Systemic vascular resistance decreased 7 (± 4)%, 15 (± 12)% and 18 (± 6)% in the three groups, respectively ( p < 0:05 in all three groups). A significant difference between the high and low dose Curosurf groups was found ( p < 0:05), whereas no significant difference was seen between the Curosurf 100 mg group and the Survanta group. The decrease in vascular resistance was compensated by an increase in cardiac output, resulting in a stable mean arterial blood pressure. In conclusion, both Curosurf and Survanta induce a significant decrease in systemic vascular resistance in surfactant-depleted newborn piglets. A more pronounced effect was observed after 200 mg/kg than after 100 mg/kg of Curosurf. 相似文献
27.
Ines Lessa Maria Jenny Araújo Lucélia Magalh?es Naomar de Almeida Filho Estela Aquino Maria Cecília R Costa 《Pan American journal of public health》2004,16(2):131-137
OBJECTIVE: To estimate the frequency of modifiable cardiovascular risk factors, with and without inclusion of arterial hypertension, occurring simultaneously in a racially-mixed population. METHOD: A cross-sectional study was carried out with 1,298 adults aged > or = 20 years in the city of Salvador, Brazil, in 2000. Eight modifiable cardiovascular risk factors were assessed, in any combination: total cholesterol > or = 240 mg/dL; high density-lipoprotein cholesterol (HDL-c) < 40 mg/dL; triglycerides > or = 200 mg/dL; glycemia > or = 126 mg/dL + well-controlled diabetes; body mass index > or = 25 kg/m2, waist > or = 102 cm for males and > or = 88 cm for females, smoking and alcoholism. The results were stratified according to the number of simultaneous risk factors (zero to five or more and two or more risk factors). The data were analyzed in terms of estimated proportions and 95% confidence intervals (95%CI), with and without the inclusion of arterial hypertension (VI Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure [JNC-VI], United States of America), ratio of proportions and chi-square for proportions as a measure of association. RESULTS: Among men (41.4% of participants), 7.5% (95%CI: 2.5 to 9.7) did not present risk factors; 68.8% (95%CI: 65.0 to 72.8) presented two or more risk factors, not including hypertension. After inclusion of hypertension, 73.4% (95%CI: 69.7 to 77.1) presented two or more risk factors. Among women, 11.6% did not present risk factors. The presence of two or more risk factors, not including hypertension, was observed in 67.7% (95%CI: 64.8 to 71.4). After inclusion of hypertension, 71.7% (95%CI: 68.5 to 74.9) of the women presented two or more risk factors. Significant differences were observed for the presence of two or more risk factors in men with not more than 4 years of schooling vs. 5 to less than 11 years of schooling (P < 0.05); in women with not more than 4 years of schooling vs. 5 to less than 11 years of schooling; in women with not more than 4 years of schooling vs. 11 or more years of schooling (P < 0.01); and in black vs. white women (P < 0.01). CONCLUSIONS: The high proportion of clustering cardiovascular risk factors in Salvador, with or without hypertension, especially in the population with little schooling and in black individuals, suggests the need for broad social strategies to reduce social inequality, promote health, and facilitate the treatment of cardiovascular risk factors. 相似文献
28.
Anti-inflammatory effects of fructose-1,6-bisphosphate on carrageenan-induced pleurisy in rat. 总被引:3,自引:0,他引:3
José Carlos Farias Alves Filho Roberto Christ Vianna Santos Telmo Abelin Castaman Jarbas Rodrigues de Oliveira 《Pharmacological research》2004,49(3):245-248
In the present study, we evaluated the effect of fructose-1,6-bisphosphate (FBP), a high energy intermediate metabolite of glycolysis, in an acute model of lung injury. Injection of carrageenan into the pleural cavity of rats elicited an acute inflammation response characterized by a fluid accumulation in the pleural cavity which contained a large number of polymorphonuclear neutrophils. FBP (500mg/kg) attenuated the inflammation parameters: exudate volume, total leukocytes and the number of polymorphonuclear leukocytes, but the protein concentration in the exudate was not significantly affected by treatment with FBP. The precise site and mechanism of the anti-inflammatory effect was not addressed, considering the diverse pharmacological actions of FBP. This drug has anti-inflammatory actions suggesting that it may represent a novel strategy for the modulation of inflammatory response. 相似文献
29.
de Jesus Lopes Filho G Matone J Arasaki CH Kim SB Mansur NS 《International surgery》2000,85(4):339-343
Psoas abscess (PA) is an infrequent clinical entity and presents diagnostic and therapeutic challenges. Six cases are reported concerning diagnostic and therapeutic considerations. Clinical diagnosis is difficult because of non-specific symptoms. The primary psoas abscess has no definite etiology and is spread by hematogeneous route from a distant occult site. The PA can also be secondary to gastrointestinal pathology through direct infection of adjacent structures. The most common causes are Crohn's disease, appendicitis, diverticulitis and carcinoma. Routine laboratory evaluation is seldom useful for localizing the disease process. Conventional radiological techniques are often unhelpful. Modern imaging diagnosis techniques such as ultrasound and computerized tomography have allowed for a refinement in both the etiologic diagnosis and the treatment by means of CT-guided or ultrasound-guided percutaneous drainage of the abscess, thus avoiding surgical drainage in many cases. Immediately on diagnosis of PA prompt treatment is necessary. Percutaneous drainage should be performed whenever possible and in case of failure, surgical drainage should be practiced as well as intestinal resection, whenever indicated. 相似文献
30.
Gabriela Datsch Bennemann Emilia Addison Machado Moreira Leticia Cristina Radin Pereira Maiara Brusco de Freitas Diane de Oliveira Julia Carvalho Ventura Eduardo Benedetti Parisotto Yara Maria Franco Moreno Erasmo Benicio Santos Moraes Trindade Eliana Barbosa Norberto Ludwig Neto Danilo Wilhelm Filho 《The clinical respiratory journal》2022,16(6):475
IntroductionOxidative stress (OS) occurs in cystic fibrosis (CF).ObjectiveThe objective of this work is to evaluate the influence of bacterial infection on biomarkers of OS (catalase [CAT], glutathione peroxidade [GPx], reduced glutathione [GSH]), markers of oxidative damage (protein carbonyls [PC], thiobarbituric acid reactive substances [TBARS]), together with the nutritional status and lung function in children with CF.MethodsCross‐sectional study including CF group (CFG, n = 55) and control group (CG, n = 31), median age: 3.89 and 4.62 years, respectively. CFG was distributed into CFG negative bacteriology (CFGB−, n = 27) or CFG positive bacteriology (CFGB+, n = 28), and CFG negative Pseudomonas aeruginosa (CFGPa−, n = 36) or CFG positive Pseudomonas aeruginosa (CFGPa+, n = 19).ResultsCompared with CG, CFG (P = .034) and CFGB+ (P = .042) had lower body mass index‐for‐age z‐score; forced expiratory volume in the first second was lower in CFGB+ and CFGPa+ (both P < .001). After adjusting for confounders and compared with CG: CFG showed higher TBARS (P ≤ .001) and PC (P = .048), and lower CAT (P = .004) and GPx (P = .003); the increase in PC levels was observed in CFGB+ (P = .011) and CFGPa+ (P = .001) but not in CFGB− (P = .510) and CFGPa− (P = .460).ConclusionsThese results indicate a systemic OS in children with CF. The presence of bacterial infection particularly Pseudomonas aeruginosa seems to be determinant to exacerbate the oxidative damage to proteins, in which PC may be a useful biomarker of OS in CF. 相似文献