全文获取类型
收费全文 | 975篇 |
免费 | 40篇 |
国内免费 | 2篇 |
专业分类
耳鼻咽喉 | 18篇 |
儿科学 | 9篇 |
妇产科学 | 54篇 |
基础医学 | 156篇 |
口腔科学 | 56篇 |
临床医学 | 65篇 |
内科学 | 243篇 |
皮肤病学 | 11篇 |
神经病学 | 83篇 |
特种医学 | 22篇 |
外科学 | 115篇 |
综合类 | 4篇 |
预防医学 | 65篇 |
眼科学 | 12篇 |
药学 | 73篇 |
中国医学 | 18篇 |
肿瘤学 | 13篇 |
出版年
2023年 | 3篇 |
2022年 | 4篇 |
2021年 | 18篇 |
2020年 | 18篇 |
2019年 | 26篇 |
2018年 | 27篇 |
2017年 | 23篇 |
2016年 | 23篇 |
2015年 | 31篇 |
2014年 | 33篇 |
2013年 | 51篇 |
2012年 | 79篇 |
2011年 | 103篇 |
2010年 | 53篇 |
2009年 | 54篇 |
2008年 | 82篇 |
2007年 | 100篇 |
2006年 | 67篇 |
2005年 | 62篇 |
2004年 | 49篇 |
2003年 | 34篇 |
2002年 | 34篇 |
2001年 | 4篇 |
2000年 | 2篇 |
1999年 | 3篇 |
1998年 | 2篇 |
1997年 | 8篇 |
1996年 | 3篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1993年 | 4篇 |
1991年 | 1篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1984年 | 1篇 |
1980年 | 1篇 |
1977年 | 2篇 |
1975年 | 3篇 |
1971年 | 1篇 |
1961年 | 1篇 |
1958年 | 1篇 |
排序方式: 共有1017条查询结果,搜索用时 106 毫秒
1.
2.
Rubira CM Devides NJ Ubeda LT Bortolucci Jr AG Lauris JR Rubira-Bullen IR Damante JH 《Brazilian Oral Research》2007,21(3):272-277
The aim of this study was to evaluate the oral sequelae of radiotherapy in patients treated between 1999 and 2003 for head and neck tumors. One-hundred patients (24 women, 76 men) ranging in age from 30 to 83 years (mean 59.2 years) were examined. Time since radiotherapy ranged from 1 to 72 months (mean 28 months). The total mean radiation dose received by the patients was 5,955 cGy. The evaluation protocol included anamnesis, intraoral and extraoral examination, measurement of stimulated salivary flow and salivary pH. Symptoms reported by the patients included dry mouth (68%), dysphagia (38%), and dysgeusia (30%). In 64% of the patients, the mean stimulated salivary flow rate was less than 0.7 ml/min. The mean salivary pH was 6.97 (+/- 0.714). Stimulated salivary flow increased with increasing postradiotherapy time (p < 0.05). The prevalence of mucositis was associated with higher radiation doses (p < 0.05), and the prevalence of atrophic candidiasis was related to a longer post-treatment period (p < 0.05). Two cases of recurrence of the primary tumor were detected during the study. The main effect of radiotheraphy in the head and neck region was a reduction of the salivary flow rate, even though our study demonstrated that there was a modest late improvement of the salivary flow. 相似文献
3.
Cláudia Regina Buainain de Freitas Maria Isabel Serra Miranda Marcelo Ferrarezi de Andrade Victor Humberto Orbegoso Flores Luís Geraldo Vaz Catanzaro Guimar?es 《Quintessence international, dental digest》2002,33(8):589-594
OBJECTIVE: The aim of this study was to evaluate the resistance to fracture of intact and restored human maxillary premolars. METHOD AND MATERIALS: Thirty noncarious human maxillary premolars, divided into three groups of 10, were submitted to mechanical tests to evaluate their resistance to fracture. Group 1 consisted of intact teeth. Teeth in group 2 received mesio-occlusodistal cavity preparations and were restored with direct resin composite restorations. Teeth in group 3 received mesio-occlusodistal cavity preparations and were restored with ceromer inlays placed with the indirect technique. After restoration, teeth were stored at 37 degrees C for 24 hours and then thermocycled for 500 cycles at temperatures of 5 degrees C and 55 degrees C. RESULTS: Statistical analysis revealed that group 3 (178.765 kgf) had a significantly greater maximum rupture load than did group 1 (120.040 kgf). There was no statistically significant difference between groups 1 and 2 or between groups 2 and 3. CONCLUSION: Class II cavity preparations restored with indirect ceromer inlays offered greater resistance to fracture than did intact teeth. The fracture resistance of teeth restored with resin composite was not significantly different from that of either the ceromer or intact teeth. 相似文献
4.
Erick Miranda Souza Amanda Martins Calixto Camila Nara e Lima Fernanda Geraldo Pappen Gustavo De-Deus 《Journal of endodontics》2014
Introduction
Stabilizing sodium hypochlorite (NaOCl) at an alkaline pH is proposed to increase solution stability and tissue dissolution ability; however, a reduction on the flexural strength of dentin discs has been found to be a side effect. This study sought to determine whether a stabilized alkaline NaOCl reduces the fracture resistance of root canal–treated bovine teeth after root canal preparation compared with a neutral solution counterpart.Methods
The 4 anterior incisors were removed from 20 mandibular bovine jaws, and each 1 was randomly assigned to 1 of 4 groups (20 teeth each). Teeth were prepared with a sequence of 6 K-type files. The following experimental groups received a different irrigation regimen: G1: distilled water (negative control), G2: 5% NaOCl at a pH of 7.2, and G3: 5% NaOCl at a pH of 12.8; in the positive control group (G4), teeth remained untreated. The time of contact and volume of solution were carefully standardized. After bone and periodontal ligament simulation, teeth were subjected to a fracture resistance test.Results
A significant difference was observed among the 4 groups tested (analysis of variance, P < .05). The 5% NaOCl groups (G2 and G3) presented significantly lower resistance to fracture than the control (G1 and G4) (Tukey test, P < .05). Both NaOCl solutions similarly reduced the fracture resistance at approximately 30% (Tukey test, P > .05). No differences were observed between positive and negative control groups (Tukey test, P > .05).Conclusions
Stabilized alkaline and neutral NaOCl solutions similarly reduced the fracture resistance of root canal–treated bovine teeth by about 30%. 相似文献5.
Elizabeth Brenda Américo Marques Paulo Hilário N. Saldiva Geraldo S. Hidalgo Saul Goldenberg 《Current therapeutic research》1995,56(12):1285-1297
Four topical drugs were studied with regard to their ability to promote healing of open wounds in 60 Wistar rats. Five study groups were defined. Four of the five groups received one of the following substances: papain, sugar, minoxidil, or glucan. The fifth group or control group received saline solution (NaCl, 0.9%). An experimental model with wound standardization (6 × 3.5 cm) was used. The raw area and new epithelium were quantified in each rat by taking photographs from which planimetry was performed. The closure of the first lesion occurred on the 49th postoperative day. Quantitative assessment of collagen deposition was performed using image analyzing software on slides stained with picrosirius and observed under polarized light. Epithelium formation was greatest in the minoxidil group, followed (in decreasing order) by the sugar, papain, control, and glucan groups. Significant differences in collagen deposition were observed among all the groups. The greatest amount of collagen was quantified in the glucan group, followed (in decreasing order) by the sugar, minoxidil, papain, and control groups. This data and possible mechanisms for the interference of each substance in wound healing are considered. 相似文献
6.
Rossi A Tomimori E Camargo R Medeiros-Neto G 《Journal of clinical ultrasound : JCU》2002,30(4):226-231
PURPOSE: Our objective was to establish thyroid volume by sonography in Brazilian schoolchildren and to correlate thyroid volume with anthropometric characteristics. METHODS: Sonographic studies of thyroid volume were conducted in 1,977 schoolchildren (6-14 years old) from 21 villages and towns in Central Brazil. Iodine concentration was analyzed in urine specimens and in salt samples obtained from the children's homes. Thyroid volumes were also compared with volumes reported for other countries. RESULTS: Age, height, and weight correlated with thyroid volume. Thyroid volumes for boys and girls were generally lower than those obtained in Europe and comparable to those obtained in Malaysia and Iran. Urinary iodine excretion was considered elevated in about half of the Brazilian schoolchildren, and the iodine content of salt samples was more than 50 ppm in 58%. CONCLUSIONS: We observed relatively smaller thyroid gland volumes in Brazilian schoolchildren as compared with those reported in Europe. This was apparently due to a higher iodine intake in our population. 相似文献
7.
Antunes AA Barbosa JA Reis ST Guariero MS Fukushima JT Dall'oglio MF Freire Gde C Lucon AM Leite KR Srougi M 《Urologic oncology》2012,30(5):620-623
ObjectiveAcute urinary retention (AUR) is expected to occur in 2% to 39% men with benign prostatic hyperplasia. To date, no study has elucidated the effect of long-term use of indwelling bladder catheter on serum prostate specific antigen (PSA) levels and on the incidence of prostate cancer (CaP). The aim of the present study is to analyze the incidence of CaP in patients with long-term use of indwelling bladder catheter and determine some practice patterns on this issue.Materials and methodsThe study comprised a retrospective analysis of data from 1,651 patients who had undergone transrectal ultrasound (TRUS)-guided prostate biopsy from July 2004 to June 2009. Among these patients, 198 (12%) were using an indwelling bladder catheter during the biopsy for at least 1 month. The incidence of CaP was recorded according to total PSA levels. Other variables such patient age, free/total PSA rate, PSA density, prostate volume, and duration of catheter use was also analyzed. Men with a digital rectal examination suspicious for cancer were not considered for analysis.ResultsMedian patient age was 71 years (37 to 89 years). Overall, 25% of patients presented a CaP diagnosis. CaP incidence according to the PSA levels was 0%, 18.9%, 24.5%, and 40.6% for patients with PSA ≤4.0, 4.1–10.0, 10.1–20.0, and >20.0 ng/ml, respectively. When prostate volume was analyzed together, we demonstrated that only 1 (2.4%) patient with PSA below 10.0 ng/ml and prostate volume >60 g had CaP. Median total PSA, PSA density, and prostate volume were statistically different between patients with and without CaP.ConclusionsProstate biopsy should not be indicated for all patients with diagnosis of BPH and AUR who present an elevated PSA level. Patients with PSA below 10.0 ng/ml, and prostate volume >60 g should only undergo biopsy in selected cases. Patients with PSA >20.0 ng/ml and a prostate volume ≤60 g are at higher risk of CaP diagnosis. 相似文献
8.
Dimitri Ceroni Rebecca Anderson de la Llana Xavier Martin Léopold Lamah Geraldo De Coulon Katia Turcot Victor Dubois-Ferrière 《Journal of children's orthopaedics》2012,6(6):497-503
Background
The significance of subclinical vitamin D deficiency in the pathogenesis of fractures in children and adolescents currently remains unclear.Objective
We aimed to determine the prevalence of vitamin D insufficiency and its effect on bone mineral density (BMD) and bone mineral content (BMC) values in a collective of Swiss Caucasian children with a first episode of appendicular fracture.Design and methods
One hundred teenagers with a first episode of appendicular fracture [50 upper limb fractures (group 1) and 50 lower limb fractures (group 2)] and 50 healthy controls (group 3) were recruited into a cross-sectional study. The BMC and BMD values were measured by dual-energy X-ray absorptiometry, and serum 25 hydroxyvitamin D [25(OH)D] was assessed by electrochemiluminescence immunoassays.Results
From the 100 injured teenagers in the study, 12 % had deficient vitamin D levels (<20 ng/mL; <50 nmol/L) and 36 % had insufficient levels (≥20 <30 ng/mL; ≥50 <78 nmol/L), whereas 6 and 34 % of healthy controls were, respectively, vitamin D deficient and insufficient. There were no significant differences for serum 25(OH)D levels, L2–L4 BMD Z-score, and L2–L4 BMC Z-score variables (p = 0.216) between the three groups nor for the calcaneal BMD Z-score variables (p = 0.278) between healthy controls and lower limb fracture victims. Investigations on the influences of serum 25(OH)D on BMD and BMC showed no correlation between serum 25(OH)D and L2–L4 BMD Z-scores (r = −0.15; p = 0.135), whereas low but significant inverse correlations were, surprisingly, detected between serum 25(OH)D and calcaneal BMD Z-scores (r = −0.21; p = 0.034) and between serum 25(OH)D and L2–L4 BMC Z-scores (r = −0.22; p = 0.029).Conclusions
A significant proportion of Swiss Caucasian teenagers were vitamin D insufficient, independent of limb fracture status, in our study. However, this study failed to show an influence of low vitamin D status on BMD and/or BMC of the lumbar spine and heel. 相似文献9.
Fernando R Oliveira Jose Geraldo L Ramos Sergio Martins-Costa 《Journal of ultrasound in medicine》2006,25(9):1153-8; quiz 1159-60
OBJECTIVE: The purpose of this study was to determine the role of translabial ultrasonography in the investigation of intrinsic urethral sphincter deficiency (ISD), assessing bladder neck hypermobility and urethral diameter in continent and incontinent patients. METHODS: A case-control study evaluated 94 women with the diagnosis of urinary incontinence and 96 continent women. Both groups underwent translabial ultrasonography to assess bladder neck hypermobility by means of the x-y coordinate system and urethral diameter. The study was performed at Hospital de Clínicas de Porto Alegre. RESULTS: Women with urinary stress incontinence showed significantly greater bladder neck descent than continent women and women with urge and mixed incontinence (P = .05). Women with ISD showed significantly larger urethral diameters than control subjects and incontinent women without ISD (P = .05). Of women with urinary incontinence, 78.7% had descent of greater than 10 mm, and 91.7% of the women with ISD had urethral diameters of greater than 6 mm. A urethral diameter of greater than 6 mm showed sensitivity of 91.7% and specificity of 75.6% for ISD. CONCLUSIONS: Translabial ultra-sonography has an important role in the assessment of women with urinary stress incontinence and intrinsic urethral sphincter deficiency. 相似文献