全文获取类型
收费全文 | 116183篇 |
免费 | 5966篇 |
国内免费 | 140篇 |
专业分类
耳鼻咽喉 | 1773篇 |
儿科学 | 5212篇 |
妇产科学 | 3937篇 |
基础医学 | 16085篇 |
口腔科学 | 2834篇 |
临床医学 | 8326篇 |
内科学 | 22025篇 |
皮肤病学 | 3360篇 |
神经病学 | 9001篇 |
特种医学 | 5050篇 |
外国民族医学 | 32篇 |
外科学 | 19039篇 |
综合类 | 1596篇 |
一般理论 | 29篇 |
预防医学 | 5832篇 |
眼科学 | 3390篇 |
药学 | 8066篇 |
中国医学 | 324篇 |
肿瘤学 | 6378篇 |
出版年
2018年 | 892篇 |
2017年 | 775篇 |
2016年 | 1095篇 |
2015年 | 1219篇 |
2014年 | 1603篇 |
2013年 | 2365篇 |
2012年 | 3110篇 |
2011年 | 3158篇 |
2010年 | 1971篇 |
2009年 | 1930篇 |
2008年 | 3263篇 |
2007年 | 3498篇 |
2006年 | 3643篇 |
2005年 | 3759篇 |
2004年 | 3700篇 |
2003年 | 3562篇 |
2002年 | 3513篇 |
2001年 | 7022篇 |
2000年 | 6967篇 |
1999年 | 5864篇 |
1998年 | 1625篇 |
1997年 | 1559篇 |
1996年 | 1335篇 |
1995年 | 1203篇 |
1994年 | 1092篇 |
1993年 | 1119篇 |
1992年 | 3767篇 |
1991年 | 3577篇 |
1990年 | 3561篇 |
1989年 | 3348篇 |
1988年 | 2986篇 |
1987年 | 2894篇 |
1986年 | 2804篇 |
1985年 | 2617篇 |
1984年 | 1944篇 |
1983年 | 1594篇 |
1982年 | 927篇 |
1981年 | 915篇 |
1980年 | 767篇 |
1979年 | 1823篇 |
1978年 | 1347篇 |
1977年 | 1111篇 |
1976年 | 936篇 |
1975年 | 1178篇 |
1974年 | 1212篇 |
1973年 | 1198篇 |
1972年 | 1040篇 |
1971年 | 975篇 |
1970年 | 880篇 |
1969年 | 787篇 |
排序方式: 共有10000条查询结果,搜索用时 12 毫秒
31.
Skeletal effects of bite jumping therapy on the mandible - removable vs. fixed functional appliances
AUTHORS: Shen G, Hagg U, Darendeliler MA. OBJECTIVE: Based on an extensive review of the literature, the aim of this study was to explore the mainstream consensus on the controversial topic of whether the bite jumping treatment could enhance mandibular growth. DESIGN: The data for removable and fixed functional appliances were respectively comprehended and analyzed with regard to their attributes in mandibular growth modification. Furthermore, numerous reported findings were assessed by relating them to some important factors influencing the effects of bite jumping, such as treatment timing, treatment duration and post-treatment follow-up, to allow for a more objective and accurate evaluation. RESULTS: The key differences between removable and fixed appliances are working hours (intermittent vs. continuous), length of treatment time (long vs. short), optimal treatment timing (before puberty growth vs. at or after puberty spurt), and mode of bite-jumping (considerable vertical opening vs. limited vertical opening). These different features lead to different treatment effects on mandibular and TMJ growth, such as the intensity of possibly increased growth (clinically less significant vs. significant), the direction of enhanced growth (vertical vs. horizontal), and the stability of treatment changes (unstable vs. stable). The short-term or long-term post-treatment relapse mainly relates to the rebound of dental position. CONCLUSION: The immediate effects of bite jumping functional appliances on the mandibular growth enhancement are convincing during actual treatment. This extra gain of growth might be sustainable during the short-term and long-term post-treatment period. 相似文献
32.
The aim of this study was to describe and compare salivary immunoglobulin A (IgA) antibody reactions to extracts of strains of three oral streptococci in human leukocyte antigen (HLA)-DR4-positive and -DR4-negative subjects. Whole paraffin-stimulated saliva samples were collected from 27 apparently healthy subjects. Previous HLA typing showed that 20 subjects were DR4 positive and 7 were DR4 negative. HLA-DRB1*04 subtyping was performed among the DR4-positive subjects. Whole-cell antigen extracts from Streptococcus mutans (KPSK 2), Streptococcus sobrinus (OMZ 65) and Streptococcus parasanguis (Nt 62) were separated in SDS-PAGE. The antigens were immunoblotted with diluted saliva (Western blot), scanned and analyzed in a computer system. All immunoblot bands were recorded in DR4-positive and DR4-negative saliva pools, and bands with an optical density >or=0.1 were selected for analysis in individual salivas. The DR4-negative subjects in general had more immunoblot bands and more distinct bands than did the DR4-positive subjects. A higher concentration of total IgA in saliva was correlated with more bands, especially to antigens separated from S. mutans. When the number of bands was calculated per IgA unit, significant differences were observed between DR4-positive and DR4-negative salivas. This was particularly seen for S. mutans and S. parasanguis. As the number of bands was analyzed in relation to DR4 subgroups, DRB1*04, there was a lower salivary IgA activity to S. mutans in the DRB1*0401 and *0404. The variable level of correlation previously demonstrated for S. mutans colonisation and serologically defined DR4 positive subjects might be explained by the heterogeneity in this group, and the relation should be sought on a subgroup level. 相似文献
33.
Shoulder complaints after nerve sparing neck dissections 总被引:1,自引:0,他引:1
van Wilgen CP Dijkstra PU van der Laan BF Plukker JT Roodenburg JL 《International journal of oral and maxillofacial surgery》2004,33(3):253-257
The purpose of the study was to analyse the prevalence of shoulder complaints after nerve sparing neck dissection at least 1 year after surgery, and to analyse the influence of radiation therapy on shoulder complaints. Patients were interviewed for shoulder complaints, and patients filled out the shoulder disability questionnaire to evaluate shoulder disability in daily activities. In total 137 patients; 51 after modified radical neck dissection (MRND), 21 after postero-lateral neck dissection (PLND), and 65 after supraomohyoid neck dissection (SOHND) were analysed. After MRND 33.3% of the patients experienced shoulder complaints, after PLND 66.7%, and after SOHND 20% of the patients experienced shoulder complaints. Type of neck dissection was significantly (P < 0.001) related to shoulder complaints. Outcome on the shoulder disability questionnaire also showed a significant (P < 0.01) difference in outcome for type of neck dissection. The prevalence of shoulder complaints after SOHND are low, and reduce disability in daily activities. Radiation therapy does not have a significant effect on shoulder complaints and disability. 相似文献
34.
Abstract
Purpose of this study was to evaluate the combined analgesic effect of gabapentin and transdermal fentanyl patch, on acute and chronic pain after surgery for maxillary cancer.Study design
The Study was double blind and prospective. 100 subjects belonging to ASA grade I and II, 30–50 years age group, scheduled for maxillary cancer surgery were randomized into two groups; treatment group (GT): to receive gabapentin, transdermal fentanyl patch or control group ©: two placebos. For acute postoperative pain (Visual Analogue Score) and analgesic requirements were assessed 2, 4, 8 hours and 7 days after surgery. Subjects were also assessed for chronic pain 2, 4, 6 months later.Results
Subjects in treatment group required lesser dose of analgesic, as compared to control group, in the post operative period. Visual Analogue Scores were also significantly lower in the treatment group throughout the post operative period. Occurrence of side effects was non significant between both groups. 2, 4 and 6 months after surgery, 40, 35 and 28 subjects respectively, out of total 45 subjects of the control group, reported chronic pain. In comparison, 25, 10 and 4 subjects out of 42 subjects in the treatment group reported chronic pain 2, 4, 6 months respectively after surgery. 15, 10 and 6 out of 45 of the control group required analgesics, whereas 2, 0 and 0 out of 42 in the treatment group, required analgesics respectively 2, 4 and 6 months after surgeryConclusion
Acute and chronic pain after maxillary cancer surgery is significantly reduced by multimodal analgesia. 相似文献35.
36.
S. Heinroth U. Bilkenroth A. W. Eckert Dr.Dr. P. Maurer 《Oral and maxillofacial surgery》2006,10(1):42-45
Background
Bone metastases in the upper jaw are relatively rare but not unusual in oral and maxillofacial surgery. In many cases finding the primary tumour is difficult because of its occult location.Case report
We describe a 53-year-old female patient who suffered from a tumor in the oral cavity. The first histological and clinical diagnosis revealed a granuloma pyogenicum. Because of the delayed healing process another biopsy became necessary showing a metastasis of an unknown primary tumor. Diagnostic procedures detected an adenocarcinoma of the left kidney with pelvic metastases. Appropriate surgical intervention and chemotherapy were subsequently initiated.Conclusion
The present case report demonstrates how difficult it can be to provide the right pathological diagnosis in biopsy material even regarding obvious malignancy. Therefore thorough diagnostic efforts are indispensable to facilitate the causal treatment of an unknown primary tumor. 相似文献37.
Márta U Zsuzsanna S József B Zsolt N Béla S György S 《The Journal of craniofacial surgery》2001,12(5):464-468
Multiple primary tumors occur more commonly in the region of the head and neck than elsewhere in the body. The chance of this is particularly high in patients treated for retinoblastoma, in part because of a genetic predisposition, and in part because of the possibility of irradiation treatment. However, triple tumors occur in only 0.5% of multiple tumors. A rare case of a triple (metachronous) tumor is reported: 12 years after the treatment of bilateral retinoblastoma (enucleation and irradiation), secondary leiomyosarcoma developed in the maxillofacial region, followed 5 years later by choriocarcinoma. Surgery was performed on all three types of tumor. As a result, the female patient (currently 21 years old) is now free of complaints and has married. It is extremely rare for either leiomyosarcoma or choriocarcinoma (CHC) to appear in the maxillofacial region. The long-term, systematic control of such patients is absolutely necessary, for the multiple tumors tend to develop only after a long latency period of 10 to 20 years. 相似文献
38.
Matis BA Gaiao U Blackman D Schultz FA Eckert GJ 《Journal of the American Dental Association (1939)》1999,130(2):227-235
BACKGROUND: The purpose of the study described here was to determine the in vivo degradation rate of 10 percent carbamide peroxide, or CP, gel in bleaching trays. The degradation rate indicates the remaining concentration of the active agent on the facial surfaces at various intervals. METHODS: The researchers fabricated bleaching trays with 0.5-millimeter reservoirs and loaded them with a 10 percent CP whitening gel. The tray was seated in place in 15 patients for six different intervals that ranged from 15 seconds to 10 hours. When the tray was removed, three samples were collected from each patient: the gel remaining in the tray; the adherent gel scraped from the teeth; and a "grab" sample from the reservoir of tooth no. 8. The researchers analyzed these samples for CP according to the method specified by the U.S. Pharmacopeial Convention. RESULTS: The percentage of CP recovered decreased as the intervals increased: 87 percent at 15 seconds, 10 percent at 10 hours. Log of tray, teeth and grab samples, respectively, at 15 seconds were 0.94, 0.98 and 0.96 and at 10 hours were -0.13, -0.38 and 0.11. The first-hour degradation rate for tray, teeth and grab samples, respectively, was 2.0 times, 3.6 times and one time the rate during the next nine hours. The within-subject repeatability of the samples was excellent. CONCLUSIONS: The degradation rate of CP during the bleaching process is biexponential. In the tray and teeth samples, the degradation rate was accelerated during the first hour. Further research is needed to determine the cause of this acceleration. CLINICAL IMPLICATIONS: The active agent in CP bleaching gel is available in bleaching trays for more than 10 hours. After two hours, more than 50 percent of the active agent is available, and 10 percent is available after 10 hours. 相似文献
39.
40.
U.Glendor A.Halling L.Bodin L.Andersson Å.Nygren G.Karlsson B.Koucheki 《Dental traumatology》2000,16(1):16-23
Abstract – The aim was to account for the total time spent by professional care‐givers (direct time) and by patients and companions engaged as support and help (indirect time) to treat and otherwise attend to children and adolescents with dental trauma to primary and permanent teeth. The study was based on a random sample of 192 children and adolescents with dental traumas reported to an insurance company and prospectively followed up by telephone interviews over a period of 2 years after the trauma episode. On average, direct time represented 16% of total time for all visits for dental trauma to permanent teeth and 11% for trauma to primary teeth. The most extensive type of indirect time was transport time, which took up 30% of the total time spent on injuries to permanent teeth and 36% for injuries to primary teeth. Multiple regression analysis of the impact of dental and demographic injury variables on the time variables showed that complicated trauma was associated with extended time, direct as well as indirect, for permanent and primary teeth injuries. Our estimate of the average relative increase in total time spent by patients and companions in cases of complicated injury to permanent teeth was 117% (95% confidence interval [CI], 52–211) for patients and 112% (95% CI, 42–217) for companions. For transport time a strong predictor was access to a dental clinic near the place of residence. Lack of access could extend the average transport time by 180% (95% CI, 80–335) for patients and 163% (95% CI, 67–317) for their companions in cases of injuries to primary teeth. 相似文献