全文获取类型
收费全文 | 28512篇 |
免费 | 2495篇 |
国内免费 | 523篇 |
专业分类
耳鼻咽喉 | 81篇 |
儿科学 | 1682篇 |
妇产科学 | 561篇 |
基础医学 | 1570篇 |
口腔科学 | 717篇 |
临床医学 | 3409篇 |
内科学 | 3228篇 |
皮肤病学 | 119篇 |
神经病学 | 1950篇 |
特种医学 | 467篇 |
外国民族医学 | 2篇 |
外科学 | 2335篇 |
综合类 | 3401篇 |
现状与发展 | 6篇 |
一般理论 | 1篇 |
预防医学 | 8174篇 |
眼科学 | 183篇 |
药学 | 1399篇 |
44篇 | |
中国医学 | 538篇 |
肿瘤学 | 1663篇 |
出版年
2024年 | 328篇 |
2023年 | 672篇 |
2022年 | 1474篇 |
2021年 | 1772篇 |
2020年 | 1562篇 |
2019年 | 1376篇 |
2018年 | 1242篇 |
2017年 | 1292篇 |
2016年 | 1272篇 |
2015年 | 1250篇 |
2014年 | 1805篇 |
2013年 | 2042篇 |
2012年 | 1642篇 |
2011年 | 1600篇 |
2010年 | 1263篇 |
2009年 | 1187篇 |
2008年 | 1085篇 |
2007年 | 1160篇 |
2006年 | 970篇 |
2005年 | 884篇 |
2004年 | 708篇 |
2003年 | 655篇 |
2002年 | 548篇 |
2001年 | 500篇 |
2000年 | 412篇 |
1999年 | 322篇 |
1998年 | 305篇 |
1997年 | 246篇 |
1996年 | 232篇 |
1995年 | 202篇 |
1994年 | 170篇 |
1993年 | 174篇 |
1992年 | 132篇 |
1991年 | 129篇 |
1990年 | 91篇 |
1989年 | 109篇 |
1988年 | 93篇 |
1987年 | 67篇 |
1986年 | 51篇 |
1985年 | 97篇 |
1984年 | 57篇 |
1983年 | 39篇 |
1982年 | 66篇 |
1981年 | 43篇 |
1980年 | 42篇 |
1979年 | 27篇 |
1978年 | 25篇 |
1977年 | 21篇 |
1976年 | 19篇 |
1975年 | 13篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
11.
Joseph Ghafari 《Orthodontics & craniofacial research》1998,1(2):118-129
The aim of this study was to evaluate the correlation between timing of emergence of the permanent teeth and sagittal occlusal changes in children enrolled in a prospective clinical trial of Class II, division 1 treatment. The children, ages 7.2–13.3 years, met strict inclusion criteria and were assigned at random to treatment with either a headgear or a Fränkel functional appliance. Relationships between maxillary and mandibular first molars and canines, as well as overjet, were measured with digital calipers on casts made every 2 months and mounted on a SAM II articulator. The emergence of a permanent tooth was scored on a scale from 1 to 3, depending on the eruptive level of the tooth from cutting through the gingiva (1) to reaching the occlusal table (3). Specifically, emergence of the second premolars (PM2) and permanent second molars (M2), the most adjacent teeth to the first molars, was evaluated as it interacted with the development of the sagittal occlusion. Treatment of the distocclusion was as effective in late childhood as in mid-childhood. Within each appliance group, the emergence of PM2 and M2 did not affect the amount of progress toward Class I significantly (p> 0.05), indicating that improvement from distocclusion to neutrocclusion with each appliance is not influenced by the timing of emergence of these teeth. Although these findings support a one-phase treatment starting in the late mixed dentition, earlier intervention in mid-childhood may be required in the presence of several developmental conditions, or when the dental and skeletal development deviate significantly in the individual patient. 相似文献
12.
13.
Genetic studies of syndromes with severe periodontitis and palmoplantar hyperkeratosis 总被引:1,自引:0,他引:1
T. C. Hart A. Stabholz J. Meyle L. Shapira T. E. Van Dyke C. W. Cutler W. A. Soskolne 《Journal of periodontal research》1997,32(1):81-89
The Papillon-Lefevre and Haim Munk syndromes are characterized by the presence of both palmoplantar hyperkeratosis (PPK) and severe early onset periodontitis. It is the early onset periodontal disease component that distinguishes these from other more common forms of PPK. It has been proposed that the periodontal disease component may be a casual association in individuals with PPK. Genetic syndromes with palmoplantar keratosis and severe early onset periodontitis may be due to specific bacterial infections in individuals with PPK. Recently, keratin gene mutations have been identified in several conditions typified by palmoplantar keratosis. The present study sought to test the hypothesis that a keratin gene defect similar to those previously identified in other PPK conditions is responsible for the Haim Munk and the Papillon-Lefevre syndromes. We have performed genetic linkage studies to test for linkage between polymorphic DNA loci within 2 cytokeratin gene families and the disease phenotype in Haim Munk syndrome and Papillon-Lefevre syndrome. Families with individuals segregating for the Haim Munk syndrome and the Papillon-Lefevre syndrome were examined to determine disease status, and genotyped for microsatellite DNA markers closely linked to the acidic (type I) and the basic (type II) cytokeratin genes on chromosomes 12 and 17. Genotype data were evaluated for microsatellite allele homozygosity in affected individuals. Results of these preliminary genetic studies suggest that the gene defect in Haim Munk syndrome is not due to a gene defect in either the type I or the type II keratin gene clusters. These findings suggest that Haim Munk syndrome may be genetically distinct from other more common forms of PPK that have been linked to the cytokeratin gene families, and suggest that mutations in genes other than keratin genes are responsible. Additional family studies are needed to confirm these preliminary findings. 相似文献
14.
牙合面尚未成洞龋早期诊断方法的进展 总被引:1,自引:0,他引:1
近20年来,由于预防工作的广泛展开,特别是氟化物的广泛应用,龋病的发病率明显下降.但牙合面龋所占比例却有所增加,常表现为在表面正常的牙釉质下向深层发展.因此,如何对尚未成洞龋作出早期正确诊断已成为口腔医生日益关注的问题,传统的视诊、探诊法已远远不能满足要求,迫切需要开发新型、有效的龋病诊断技术.本文介绍几种牙合面尚未成洞龋的诊断方法. 相似文献
15.
Thitasomakul S Thearmontree A Piwat S Chankanka O Pithpornchaiyakul W Teanpaisan R Madyusoh S 《Community dentistry and oral epidemiology》2006,34(6):429-436
Abstract – Objective: To examine the rate and pattern of early childhood caries (ECC) development and to investigate the transitional changes of the carious lesions during a follow‐up period of 3–9 months. Methods: A longitudinal observational community‐based survey of 599 children, 9–18 months old. The children's dental examinations were first carried out at the age of 9 months with re‐examination at 12 and 18 months by five dentists using standardized methods. The affected rates of dental caries were determined for prevalence, incidence density for risk of caries per person (IDp) and risk by surface (IDs). Changes in dental status over time were explored from unerupted (U) to sound (S), including enamel caries (D1), dentine caries (D2) and caries involving pulp (D3) by computing transitional probabilities. Results: The prevalence of caries was 2.0%, 22.8% and 68.1% among 9‐, 12‐ and 18‐month olds, respectively. The IDp observed for newly affected children 9–12 and 12–18 months old was 10.32 and 15.70 persons/100 person‐months, respectively. The IDs for children 9–12 months old was 2.17 newly affected surfaces/100 surface‐months whereas it was 2.22 surfaces/100 surface‐months for children 12–18 months old. The buccal surface of maxillary incisors was the most affected (44.9%) followed by lingual, mesial and distal surfaces, respectively. The transitional probability of caries progression ranged between 1.79% and 15.38% during the follow‐up period from 9 to 12 months old. It was 3.43–39.60% from 12 to 18 months old. Conclusions: An extremely high caries‐affected rate was found among the study children even before the age of 18 months. The buccal surface of the maxillary incisors was the most affected. The teeth acquired caries at 3–6 months after initial eruption and carious lesions developed continuously over time. 相似文献
16.
Chiu CJ Lee WC Chiang CP Hahn LJ Kuo YS Chen CJ 《Journal of public health dentistry》2002,62(1):28-31
OBJECTIVES: The aims of the present study were to evaluate the frequent clinical complaints of oral submucous fibrosis (OSF) and to develop a scoring system for early detection of the disease by a self-administered questionnaire. METHODS: A total of 296 subjects were recruited, including 123 OSF patients without oral cancer and 173 betel quid chewers without OSF or oral cancer. A self-administered questionnaire was used to collect the symptom profile from study subjects. Their maximal mouth opening (MMO) between upper and lower incisor edges was measured and recorded by well-trained nurses. A binary logistic regression model examining the likelihood of OSF based on the eight symptoms of interest was used to develop the scoring system. RESULTS: Among 79 OSF subjects with an MMO < 35 mm, the most frequent complaint was trismus (87.3%), followed by burning sensation (76.0%) and xerostomia (72.2%). Among 44 OSF subjects with an MMO > or = 35 mm, burning sensation (68.2%) was the most frequent complaint, followed by trismus (54.5%) and xerostomia (54.5%). Six frequent complaints including trismus, burning sensation, xerostomia, sore throat, numbness, and oral ulceration were utilized to develop a scoring system for the early detection of OSF. The scoring system had an area under the receiver operating characteristic curve of 0.90. CONCLUSION: This study suggests a screening questionnaire of frequent complaints for the early detection of OSF. 相似文献
17.
OBJECTIVE: This study assesses parenting behaviors, health behaviors and attitudes in a sample of disadvantaged African-American fathers and evaluates the potential of fathers as recipients of oral health promotion interventions. METHODS: Participants were 60 African-American fathers whose children were enrolled in a childhood caries prevention study at Women and Infant Child Program (WIC) (n=25) or who were members of a Young Fathers' Program (n=35) at an urban health center. Demographic factors, oral health knowledge, dental self-efficacy, parenting behaviors, readiness to change, and health promotion behaviors were assessed. RESULTS: Participants averaged 30.8 years of age (sd=8.6); children averaged 2.1 years (sd=0. 9). Half of the fathers always have lived with their own children and 92% had regular physical contact with their children. Almost half of the sample reported 'fair/poor' oral health status, while less than 25% reported 'fair/poor' general health. Fathers had high oral health knowledge scores (x=7.7 correct of 9 items), and high readiness for change scores at the action stage (X=12.2 of 15; sd=1.9). dental self-efficacy scores were moderate (X=15.7 of 24; sd=5.5). Half of the fathers shared or had sole responsibility for brushing their children's teeth; 90% report children's teeth were brushed daily. CONCLUSIONS: African- American fathers participated in childrearing and oral health promotion behaviors. 相似文献
18.
De Marchi RJ Hugo FN Padilha DM Hilgert JB Machado DB Durgante PC Antunes MT 《Journal of oral rehabilitation》2011,38(7):533-540
There is evidence suggesting that edentulous older persons modify their diet, avoiding foods that are difficult to chew, such as fruit and vegetables; meanwhile, the consumption of these foods is associated with prevention of chronic diseases. However, few studies evaluated whether a poor oral status without prosthetic rehabilitation is associated with a reduction in the consumption of fruit and vegetables in community-dwelling older persons. We evaluated the association of oral status with emphasis on complete dentures use with the daily consumption of at least 400 g of fruit and vegetables, following the recommendations of the WHO. A random sample of 282 south Brazilians ≥60 years of age was evaluated. Measurements included a questionnaire to assess sociodemographic, behaviour, and health data; consume of fruit and vegetables by means of a 24-h diet recall, and oral status assessment, by means of oral examinations assessing the number of teeth and use of dental prosthesis. Multivariate Poisson regression showed that the only variable significantly associated with inadequate consumption of fruit and vegetables was edentulism with the use of only one denture [PR=1·75 (1·11-2·74)]. Edentulous participants wearing only one denture were less likely to consume at least 400 g day(-1) of fruit and vegetables. These results indicate that, in edentulous community-dwelling elderly, oral health rehabilitation might play an important role in the maintenance of consumption of adequate amounts of fruit and vegetables, which is an important component of a healthy diet and also in the prevention of chronic diseases. 相似文献
19.
Banting DW Amaechi BT Bader JD Blanchard P Gilbert GH Gullion CM Holland JC Makhija SK Papas A Ritter AV Singh ML Vollmer WM 《Journal of public health dentistry》2011,71(4):335-344
Objectives: This report describes the training of dental examiners participating in two dental caries clinical trials and reports the inter‐ and intra‐examiner reliability scores from the initial standardization sessions. Methods: Study examiners were trained to use a modified International Caries Detection and Assessment System II system to detect the visual signs of non‐cavitated and cavitated dental caries in adult subjects. Dental caries was classified as no caries (S), non‐cavitated caries (D1), enamel caries (D2), and dentine caries (D3). Three standardization sessions involving 60 subjects and 3,604 tooth surface calls were used to calculate several measures of examiner reliability. Results: The prevalence of dental caries observed in the standardization sessions ranged from 1.4 percent to 13.5 percent of the coronal tooth surfaces examined. Overall agreement between pairs of examiners ranged from 0.88 to 0.99. An intra‐class coefficient threshold of 0.60 was surpassed for all but one examiner. Inter‐examiner unweighted kappa values were low (0.23‐0.35), but weighted kappas and the ratio of observed to maximum kappas were more encouraging (0.42‐0.83). The highest kappa values occurred for the S/D1 versus D2/D3 two‐level classification of dental caries, for which seven of the eight examiners achieved observed to maximum kappa values over 0.90. Intra‐examiner reliability was notably higher than inter‐examiner reliability for all measures and dental caries classifications employed. Conclusion: The methods and results for the initial examiner training and standardization sessions for two large clinical trials are reported. Recommendations for others planning examiner training and standardization sessions are offered. 相似文献
20.
OBJECTIVE: To compare early dental implant loading in irradiated and non-irradiated oral cancer patients in order to accelerate masticatory function improvement and quality of life. PATIENTS AND METHODS: One hundred and fourteen non-submerged interforaminal ITI implants were early loaded in 30 patients after 3 weeks in situ (telescoped overdenture). Nineteen patients received 72 implants (63%) after local irradiation; 11 non-irradiated patients received 42 implants (37%) with a 24-month follow-up. RESULTS: At 24 month follow-up, one early failure had occurred in an irradiated patient (=99% functioning implants in situ). Peri-implant bleeding and plaque index were similarly high in both groups (40 to 68% average).The Results of other measured parameters were as follows (values for mean; irradiated; non-irradiated patients with respective standard deviations; significance of comparison): bone loss (0.9+/-0.9; 1.4+/-0.9; 0.4+/-0.5 mM; P<0.01); Periotest score (-2.7+/-2.7; -2.4+/-2.2; -3.1+/-3.3; P<0.2); gingival recession (0.6+/-0.7 mM; 0.8+/-0.9 mM; 0.4+/-0.5 mM, P<0.02); and peri-implant probing depths (3+/-1.2; 2.6+/-0.6; 3.4+/-1.7 mM; P<0.002). CONCLUSION: The results suggest reliable non-submerged implantation and early loading. However, bone loss in irradiated mandibles, combined with higher average Periotest values and gingival recession in an oral environment of altered saliva quantity, quality, microflora and local scarring, requires extended follow-up. 相似文献