全文获取类型
收费全文 | 16784篇 |
免费 | 1438篇 |
国内免费 | 150篇 |
专业分类
耳鼻咽喉 | 62篇 |
儿科学 | 64篇 |
妇产科学 | 20篇 |
基础医学 | 400篇 |
口腔科学 | 14358篇 |
临床医学 | 395篇 |
内科学 | 562篇 |
皮肤病学 | 169篇 |
神经病学 | 64篇 |
特种医学 | 165篇 |
外科学 | 370篇 |
综合类 | 891篇 |
预防医学 | 580篇 |
眼科学 | 7篇 |
药学 | 197篇 |
7篇 | |
中国医学 | 24篇 |
肿瘤学 | 37篇 |
出版年
2023年 | 462篇 |
2022年 | 403篇 |
2021年 | 717篇 |
2020年 | 750篇 |
2019年 | 810篇 |
2018年 | 696篇 |
2017年 | 724篇 |
2016年 | 712篇 |
2015年 | 694篇 |
2014年 | 977篇 |
2013年 | 1019篇 |
2012年 | 773篇 |
2011年 | 786篇 |
2010年 | 588篇 |
2009年 | 594篇 |
2008年 | 605篇 |
2007年 | 583篇 |
2006年 | 530篇 |
2005年 | 489篇 |
2004年 | 423篇 |
2003年 | 420篇 |
2002年 | 362篇 |
2001年 | 326篇 |
2000年 | 267篇 |
1999年 | 225篇 |
1998年 | 236篇 |
1997年 | 257篇 |
1996年 | 243篇 |
1995年 | 190篇 |
1994年 | 160篇 |
1993年 | 164篇 |
1992年 | 205篇 |
1991年 | 162篇 |
1990年 | 145篇 |
1989年 | 152篇 |
1988年 | 165篇 |
1987年 | 137篇 |
1986年 | 134篇 |
1985年 | 143篇 |
1984年 | 106篇 |
1983年 | 94篇 |
1982年 | 85篇 |
1981年 | 83篇 |
1980年 | 96篇 |
1979年 | 81篇 |
1978年 | 67篇 |
1977年 | 80篇 |
1976年 | 68篇 |
1975年 | 57篇 |
1974年 | 65篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
Othman Shibly Robert E. Schifferle Sebastian G. Ciancio Majd Tarakji Maryanne L. Mather 《Journal of clinical periodontology》1997,24(4):260-263
Abstract A single blind 30 day study compared the reduction of plaque and gingivitis for the Hapika® Powerbrush to the Interplak® ultra 10 tuft. A longitudinal parallel group design was utilized and screening evaluation was performed to determine patient eligibility prior to study enrollment. 66 subjects were entered into the study and assigned to 1 of 2 groups, each using one of the toothbrushes. At baseline, subjects received an oral soft tissue exam, a dental hard tissue exam, and were scored by the Lobene modification of the Löe and Silness gingival index (GI). Plaque was then disclosed and scored both pre and post brushing using the modified Turesky plaque/debris examination and an interproximal bleeding examination was performed post-brushing. On days 15 and 30, after an oral soft tissue and GI examination, plaque was graded by the Modified Turesky plaque/debris exam. Subjects then brushed and were graded by the Modified Turesky plaque/debris examination and an interproximal bleeding index examination. The results showed that both brushes provided a similar change in clinical indices. All produced a statistically significant reduction from baseline to day 30 for the gingival index (26.5-29.1%), the bleeding index (13.8-24.1%), and the plaque index (16.9-19.4%), A comparison of pre and post brushing scores for the plaque index at 30 showed that both brushes reduced plaque similarly with a statistically significant reduction (P<0.05) from their pre-brushing plaque index scores at all time periods. 相似文献
32.
33.
Gérard Brunel Edmond Benqué Frédéric Elharar Catherine Sansac Jean François Duffort Pierre Barthet Eric Baysse Neal Miller 《Clinical oral implants research》1998,9(5):303-312
The aim of the present study was to evaluate the combined application of different bioabsorbable materials for healing of residual peri‐implant defects after placement of non‐submerged implants into fresh extraction sockets. Second and third mandibular premolars were extracted from 10 Beagle dogs, the coronal part of the distal sockets were surgically enlarged and this was followed by immediate placement of specially designed hollow‐screw non‐submerged dental implants. For each animal, the coronal peri‐implant defects were further treated with one of the 4 following procedures: 1) no treatment, control site: 2) grafting with porous hydroxyapatite (HA); 3) collagen membrane tightly secured around the implant and over the defect and 4) grafting with HA covered with a collagen membrane. After 16 weeks of healing, specimens were removed from the mandibule and prepared for a histomorphometric evaluation. The bone-to-implant contact length (BIC) was measured and compared amongst the different treatment modalities. In the defect area, the irregular bone regeneration was similar between all the treatment procedures ( P >0.10). In the sites covered with a collagen membrane alone, the total BIC (47%) was greater than in control sites (28.7%. P <0.05) or sites grafted with HA (22.2%, P <0.02). Total BIC in sites treated with the HA‐membrane combination (43%) was only significantly different from sites treated with HA ( P <0.10). It is concluded that the use of bioabsorbable materials results in a limited increase of osseointegration when used in conjunction with immediate placement of non-submerged implants, although the principle of the one stage surgical approach can be maintained. 相似文献
34.
A 5-year retrospective analysis of employer-provided dental care for Finnish male industrial workers
Jari Ahlberg Risto Tuominen Heikki Murtomaa 《Community dentistry and oral epidemiology》1997,25(6):419-422
Abstract The treatment-mix, treatment time, and dental status of 268 male industrial workers entitled to employer-provided dental care were studied. The data were collected from treatment records of the covered workers over the 5-year period 1989-93. Treatment time was based on clinical treatment time recorded per patient visit, and the treatment procedure codes were reclassified into a treatment-mix according to American Dental Association categories, with a modification combining endodontics and restorative treatment. The mean number of check-ups followed by prescribed treatment (treatment courses) during the 5 years was 3.7 among those who had entered the in-house dental care program prior to the monitored period (old attenders). Their treatment time was stable, 57–63 min per year, while the first-year mean treatment time (170 min) of those who had entered the program during the study period (new attenders) was significantly higher (P<0.01) than the 5-year mean of the old attenders (61 min). Over the first 2 years, the treatment-mix of the new attenders showed a rise in diagnostic and preventive procedures from one-third to about one-half of all procedures, as it was for the old attenders. The new attenders' mean number of carious teeth (2.7), registered at the initial check-up visit, paralleled the mean recently demonstrated in the similar non-covered population. It was significantly higher than the 5-year mean of the old attenders (0.5) (P<0.001), but declined to the same level after the first year of treatment. It was concluded that the studied program seemed to contribute to a stabilization of treatment-mix, and to the establishment of a shorter annual treatment time within the first 2 years of treatment. 相似文献
35.
Abstract – This study describes the early microbial colomization of teeth by the use of light-and transmission electron microscopy. Six dental students carried a total of 60 test pieces of unerupted enamel and root surface in intraoral acrylic appliances for 4, 8, 12, 24 and 48 h, during which periods oral hygiene was abandoned. Pronounced variations were recorded in structure and thickness of the pellicle across the individual surfaces of both dental tissues. Bacterial single-cell colonization increased the electron density of the adjoining pellicle. Micro-colonies of bacteria were observed in relation to enamel surface irregularities such as perikymata, while the distribution on root surfaces appeared incidental. Root surfaces were generally colonized by thicker deposits than homologous enamel surfaces although the structural composition of the microbiota was similar. Gram-positive bacteria with thick cell walls appeared in coccoid or rod-shaped configurations depending on the age of the bacterial deposit. These bacteria were further characterized by selective invasion between collagen fibers. After 48 h the complexity of the microbiota was increased by the establishment of new bacterial species in the superficial layer. It is concluded that the pattern and composition of the early microbiota on teeth is more complex and variable than hitherto assumed. 相似文献
36.
A case report is presented of a massive residual dental cyst that involved over half an edentulous mandible. Presentation, diagnosis and management of the massive cyst is discussed. 相似文献
37.
Sibilla Bjarnason Stefán Y. Finnbogason Peter Holbrook Birgitta Köhler 《Community dentistry and oral epidemiology》1993,21(4):194-197
Abstract – In order to evaluate trends in caries experience, a 20% random sample of 12-yr-old residents of Reykjavik, Iceland (252 children) was examined clinically and radiographically in 1991 under conditions consistent with those of the survey conducted in 1984. In addition to caries data, frequency of toothbrushing and use of fluoride dentifrice were recorded. The mean DFT and DPS were 3.0 and 4.1, respectively. The decrease in caries experience reached 60% with an annual fall in DPS of nearly 10%. During the 7-yr period between examinations the decline in DFT and DFS scores averaged 5.2 and 8, respectively, the annual reduction amounting to 0.7 DF teeth or 1.1 DF surfaces per child. The ratio of approximal/occlusal caries and the proportion of approximal caries were similar in both surveys. Fourteen percent of the children were free from manifest caries in 1991, but only 2% in 1984. Polarization between low and high prevalence individuals had intensified. Ninety-five percent of the children brushed their teeth regularly and 97% reported using a fluoride dentifrice. 相似文献
38.
Abstract –This study investigated whether two new composite dental indicators -"the number of functioning teeth" and "the number of sound-equivalent teeth" are more efficient than the conventional DM FT index in revealing the social and behavioural factors which are significantly related to oral health status. The arbitrary set of weights given to the T-Health indicator was also evaluated. The number of functioning teeth was defined as the aggregate of filled (otherwise sound) and sound teeth. The T-Health was defined as a weighted average of sound teeth, filled (otherwise sound) teeth and teeth with some decay, the weights intended in principle to represent the relative amounts of sound tissue in these three categories of teeth. An arbitrary set of weights was used: 4, 2, and 1 for sound, filled, and decayed teeth, respectively. 164 families (father, mother and at least one 13-yr-old child) from Belo Horizonte, Brazil, were randomly selected from 13-yr-old children from private and state schools. The parents'ages ranged from 35 to 44 yr. Socio-economic status, area of residence, level of education, family income, sugar consumption, toothbrushing frequency and type of dental attendance were the social and behavioural oral health risk-factors considered in this study. The results indicated that the two new dental indicators are more sensitive to the influence of social and behavioural factors, such as those investigated here, than is the traditional DM FT index. A different set of weights (4, I, and I for sound, filled, and decayed) was suggested for the construction of the T-Health. 相似文献
39.
Philip Anthony Mileman Erik Mulder Leo van der Weele 《Community dentistry and oral epidemiology》1992,20(4):175-180
The purpose of this study was to describe the role played by the ability to estimate caries depth in successfully deciding to treat dentin caries when making use of bitewing radiographs as a diagnostic test. A 10% random sample (n = 444) of Dutch dental practitioners was sent a two-wave questionnaire concerning radiographic caries diagnosis and restorative treatment decision making. The second wave consisted of simulated bitewing radiographs of 105 tooth surfaces with and without dentin caries according to two measuring standards: (a) a micro-radiographic "gold" standard and (b) a norm of expert observers. The dentists were asked to diagnose caries at 4 depths of penetration using a 5-point certainty scoring system to measure diagnostic ability; and to make a treatment decision for each surface. The overall response was 61% (273). A regression analysis was carried out using the chance per dentist of correctly deciding to treat dentin caries as the dependent variable. The degree of agreement with the experts' diagnosis of radiographic caries depth was used to create variables measuring diagnostic ability. Five significant (P less than 0.05) variables explained 60% (R2 = 0.60) of the variation in decision making. The best diagnostic ability variable explained 47% of the variation while the treatment criterion reportedly used explained 3%. We conclude that the ability of practitioners to interpret radiographs plays a major role in treatment decision making and that their reported treatment decision making criteria should not be taken at face value. 相似文献
40.
Linda Shaw Michael Jeremy Shaw Thomas Donald Foster 《Community dentistry and oral epidemiology》1989,17(4):187-189
Although there is relatively little information concerning the oral health of handicapped adults there is increasing evidence to suggest that their oral condition, particularly periodontal health, is poor. The present investigation involved assessment of 382 handicapped patients attending four different Adult Training Centres in Birmingham. The caries status, oral hygiene, and periodontal conditions were evaluated and the Community Periodontal Index of Treatment Need (CPITN) was calculated. In order to assess the manual dexterity and the comprehension of the trainees a standard test was devised. This consisted of timing each participant in carrying out simple instructions to pick up and position certain common objects. The results indicated high levels of plaque, calculus, and bleeding with a mean CPITN of 7.43. The mean time taken for the manual dexterity and comprehension test was 23.9 seconds with a range from 10 to 80 seconds, S.E.+/- 1.33. This compares with results from 34 "normal" adults of a mean time of 8.2 seconds +/- 1.8 with a range of 6 to 12 seconds. There was no significant correlation between the Manual Dexterity and Comprehension scores and the periodontal indices in the handicapped adults. 相似文献