全文获取类型
收费全文 | 402篇 |
免费 | 18篇 |
国内免费 | 18篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 29篇 |
妇产科学 | 5篇 |
基础医学 | 31篇 |
口腔科学 | 4篇 |
临床医学 | 41篇 |
内科学 | 111篇 |
皮肤病学 | 11篇 |
神经病学 | 8篇 |
特种医学 | 59篇 |
外科学 | 58篇 |
综合类 | 21篇 |
预防医学 | 12篇 |
眼科学 | 4篇 |
药学 | 28篇 |
肿瘤学 | 15篇 |
出版年
2022年 | 1篇 |
2021年 | 2篇 |
2020年 | 2篇 |
2019年 | 2篇 |
2018年 | 4篇 |
2017年 | 2篇 |
2016年 | 1篇 |
2015年 | 5篇 |
2014年 | 6篇 |
2013年 | 11篇 |
2012年 | 3篇 |
2011年 | 4篇 |
2010年 | 10篇 |
2009年 | 19篇 |
2008年 | 13篇 |
2007年 | 28篇 |
2006年 | 17篇 |
2005年 | 16篇 |
2004年 | 10篇 |
2003年 | 10篇 |
2002年 | 6篇 |
2001年 | 20篇 |
2000年 | 13篇 |
1999年 | 9篇 |
1998年 | 14篇 |
1997年 | 13篇 |
1996年 | 19篇 |
1995年 | 8篇 |
1994年 | 19篇 |
1993年 | 13篇 |
1992年 | 8篇 |
1991年 | 4篇 |
1990年 | 3篇 |
1989年 | 19篇 |
1988年 | 9篇 |
1987年 | 12篇 |
1986年 | 18篇 |
1985年 | 11篇 |
1984年 | 10篇 |
1983年 | 9篇 |
1982年 | 7篇 |
1981年 | 9篇 |
1980年 | 7篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1977年 | 6篇 |
1975年 | 3篇 |
1973年 | 1篇 |
排序方式: 共有438条查询结果,搜索用时 15 毫秒
71.
72.
73.
74.
Christina Erbe Dr/HR Sandra Hornikel Irene Schmidtmann Heiner Wehrbein 《Journal of orofacial orthopedics》2011,72(1):13-20
Objective
The placement of orthodontic bands usually increases plaque accumulation due to numerous mechanical retention sites. The purpose of this investigation was to evaluate the amount and distribution pattern of biofilm in the oral (palatal and lingual) and interproximal regions surrounding orthodontic bands.Materials and Methods
We evaluated the formation of biofilm on 32 orthodontic bands which had been placed intraorally for 6?C37?months. Two parameters were measured: the percentage of surface covered by biofilm (quantity) and the biofilm distribution pattern of accumulation. We measured these two parameters in four regions of interest: the mesial and distal interproximal regions, as well as the mesial and distal regions of the oral attachment.Results
The quantity of biofilm formation was similar in all four regions of interest, ranging from 13.3% to 16.8%. In contrast to biofilm quantity, distribution patterns differed in the four regions. In the mesial and distal interproximal regions it appeared as extensive insular areas in 87.5% and 71.9%, respectively, whereas it appeared more often supragingival and linear in nature in regions adjacent to the oral attachment, i.e. in 65.6% and 68.8%, respectively.Conclusion
Our results indicate that firstly, oral hygiene in the palatal and lingual regions of orthodontic bands seems as difficult as it is in the interproximal areas, thus requiring thorough hygiene in both areas. Secondly, orthodontic patients with a history of periodontal disease require special attention regarding the use of orthodontic bands. 相似文献75.
Martin BR Wiley JL Beletskaya I Sim-Selley LJ Smith FL Dewey WL Cottney J Adams J Baker J Hill D Saha B Zerkowski J Mahadevan A Razdan RK 《The Journal of pharmacology and experimental therapeutics》2006,318(3):1230-1239
Presently, there are numerous structural classes of cannabinoid receptor agonists, all of which require solubilization for experimental purposes. One strategy for solubilizing water-insoluble tetrahydrocannabinols is conversion of the phenolic hydroxyl to a morpholinobutyryloxy substituent. The hydrochloride salts of these analogs are water-soluble and active in vivo when administered in saline. The present investigation demonstrated that hydrochloride salts of numerous substituted butyryloxy esters are water-soluble and highly potent. The substitutions include piperidine, piperazine, and alkyl-substituted amino moieties. It was also discovered that incorporation of a nitrogenous moiety in the alkyl side chain increased the pharmacological potency of tetrahydrocannabinol. For example, an analog containing a pyrazole in the side chain (O-2545) was found to have high affinity and efficacy at cannabinoid 1 (CB(1)) and CB(2) receptors, and when dissolved in saline, it was highly efficacious when administered either intravenously or intracerebroventricularly to mice. A series of carboxamido and carboxylic acid amide analogs exhibited high pharmacological potency, but their hydrochloride salts were not water-soluble. On the other hand, incorporation of imidazoles into the terminus of the side chain led to water-soluble hydrochloride salts that were highly potent when administered in saline to laboratory animals. It is now possible to conduct cannabinoid research with agonists that are water-soluble and thus obviating the need of solubilizing agents. 相似文献
76.
Eruptive syringoma is a very rare variant of syringoma. It is a benign adnexal tumor of the intraepidermal portion of eccrine sweat ducts. Here we report a 32-year-old female presented with classical asymptomatic eruptive syringomas involving her face and extremities. 相似文献
77.
78.
S. KlÖHR R. ROTH T. HOFMANN R. ROSSAINT M. HEESEN 《Acta anaesthesiologica Scandinavica》2010,54(8):909-921
Background: Spinal anaesthesia for caesarean section may cause hypotension, jeopardizing the foetus and its mother. We aimed to identify the spectrum of definitions of hypotension used in the scientific literature. In a second part, we applied these definitions to a prospective cohort in order to evaluate the effect of different definitions on the incidence of hypotension. Methods: A systematic literature search in PubMed was performed from 1999 to 2009 with the search terms ‘hypotension’ and ‘caesarean section’. Consecutive parturients undergoing caesarean section under spinal anaesthesia were included in a prospective study. Results: Sixty‐three eligible publications (7120 patients) were retrieved, revealing 15 different definitions of hypotension. A decrease below 80% baseline and the combined definition of a blood pressure below 100 mmHg or a decrease below 80% baseline were the two most frequent definitions, found in 25.4% and 20.6% of the papers, respectively. When applying the spectrum of definitions to a prospective cohort, the incidences of hypotension varied between 7.4% and 74.1%. The incidence increased from 26.7% to 38.5% when using a value below 75% of baseline instead of below 70% of baseline. Conclusion: There is not one accepted definition of hypotension in the scientific literature. The incidence of hypotension varies depending on the chosen definition. Even minor changes of the definition cause major differences in the frequency of hypotension. This makes it difficult to compare studies on interventions to treat/prevent hypotension and probably hampers progress in this area of research. 相似文献
79.
OBJECTIVE: To investigate the cancer-promoting effect of Taiwan betel quid in hamster buccal pouch carcinogenesis.
MATERIALS AND METHODS: Two hundred and fifty-two non-inbred mate adult Syrian golden hamsters were randomly divided into six groups, each containing forty-two animalS. A treatment regimen over a 14-week experimental period was employed with six animals per group being killed at seven different periods (every 2 weeks). The right buccal pouch of each animal was painted three times a week with various combinations of 7, 12-dimethylbenz[a]anthracene (DMBA), Taiwan betel quid extract, dimethyl sulfoxide (DMSO) and mineral oil.
RESULT: Both the number and size of tumors in animals concurrently treated with DMBA and betel quid were significantly higher than those in animals treated with DMBA alone in each killing period of 8, 10, 12 and 14 weekS. No visible tumors but hyperkeratosis and acanthosis were observed in pouches treated with betel quid alone for all killing periods.
CONCLUSION: Our results indicate Taiwan betel quid may be a co-carcinogen in human oral carcinogenesis, if extrapolation can be made from the current animal study. 相似文献
MATERIALS AND METHODS: Two hundred and fifty-two non-inbred mate adult Syrian golden hamsters were randomly divided into six groups, each containing forty-two animalS. A treatment regimen over a 14-week experimental period was employed with six animals per group being killed at seven different periods (every 2 weeks). The right buccal pouch of each animal was painted three times a week with various combinations of 7, 12-dimethylbenz[a]anthracene (DMBA), Taiwan betel quid extract, dimethyl sulfoxide (DMSO) and mineral oil.
RESULT: Both the number and size of tumors in animals concurrently treated with DMBA and betel quid were significantly higher than those in animals treated with DMBA alone in each killing period of 8, 10, 12 and 14 weekS. No visible tumors but hyperkeratosis and acanthosis were observed in pouches treated with betel quid alone for all killing periods.
CONCLUSION: Our results indicate Taiwan betel quid may be a co-carcinogen in human oral carcinogenesis, if extrapolation can be made from the current animal study. 相似文献
80.
Variations of the arterial pattern in the upper limb revisited: a morphological and statistical study, with a review of the literature 总被引:6,自引:0,他引:6
M. RODRÍGUEZ-NIEDENFÜHR T. VÁZQUEZ L. NEARN B. FERREIRA I. PARKIN J. R. SAÑUDO 《Journal of anatomy》2001,199(5):547-566
A total of 192 embalmed cadavers were examined in order to present a detailed study of arterial variations in the upper limb and a meta-analysis of them. The variable terminology previously used was unified into a homogenous and complete classification, with 12 categories covering all the previously reported variant patterns of the arm and forearm. 相似文献