全文获取类型
收费全文 | 62737篇 |
免费 | 4178篇 |
国内免费 | 161篇 |
专业分类
耳鼻咽喉 | 991篇 |
儿科学 | 2499篇 |
妇产科学 | 1385篇 |
基础医学 | 6998篇 |
口腔科学 | 8955篇 |
临床医学 | 5288篇 |
内科学 | 11508篇 |
皮肤病学 | 1563篇 |
神经病学 | 5065篇 |
特种医学 | 1999篇 |
外国民族医学 | 4篇 |
外科学 | 8549篇 |
综合类 | 435篇 |
一般理论 | 35篇 |
预防医学 | 3868篇 |
眼科学 | 1275篇 |
药学 | 3454篇 |
4篇 | |
中国医学 | 287篇 |
肿瘤学 | 2914篇 |
出版年
2024年 | 83篇 |
2023年 | 814篇 |
2022年 | 463篇 |
2021年 | 1186篇 |
2020年 | 875篇 |
2019年 | 1115篇 |
2018年 | 2060篇 |
2017年 | 1642篇 |
2016年 | 1759篇 |
2015年 | 1828篇 |
2014年 | 2118篇 |
2013年 | 2951篇 |
2012年 | 4173篇 |
2011年 | 4684篇 |
2010年 | 2435篇 |
2009年 | 1998篇 |
2008年 | 3876篇 |
2007年 | 4169篇 |
2006年 | 3977篇 |
2005年 | 3942篇 |
2004年 | 3787篇 |
2003年 | 3599篇 |
2002年 | 3272篇 |
2001年 | 1352篇 |
2000年 | 1451篇 |
1999年 | 1009篇 |
1998年 | 581篇 |
1997年 | 503篇 |
1996年 | 443篇 |
1995年 | 401篇 |
1994年 | 362篇 |
1993年 | 305篇 |
1992年 | 405篇 |
1991年 | 308篇 |
1990年 | 311篇 |
1989年 | 230篇 |
1988年 | 275篇 |
1987年 | 234篇 |
1986年 | 179篇 |
1985年 | 191篇 |
1984年 | 194篇 |
1983年 | 155篇 |
1982年 | 155篇 |
1981年 | 106篇 |
1980年 | 83篇 |
1979年 | 114篇 |
1978年 | 93篇 |
1977年 | 85篇 |
1974年 | 79篇 |
1973年 | 96篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
Color Stability of Dry Earth Pigmented Maxillofacial Silicone A-2186 Subjected to Microwave Energy Exposure 总被引:2,自引:0,他引:2
Sudarat Kiat-amnuay DDS MS ; Dennis A. Johnston PhD ; John M. Powers PhD ; Rhonda F. Jacob DDS MS 《Journal of prosthodontics》2005,14(2):91-96
PURPOSE: The purpose of this study was to measure spectrophotometrically the color stability of pigmented A-2186 silicone maxillofacial elastomer with 10% by volume of titanium white dry earth opacifier before and after exposure to microwave energy over a simulated 1.5-year period of microwave sterilization. Materials AND METHODS: A-2186 silicone elastomer opacified with titanium white dry earth pigment, pigmented with 5 cosmetic dry earth pigment colors [no pigment (control) group (Pc), red (Pr), yellow ochre (Py), burnt sienna (Po), and a mixture of Pr + Py + Po color group (P3)], was used in this study. Each of the 5 experimental groups consisted of 5 specimens. All specimens were placed in a 250 ml glass beaker filled with 150 ml of water (replenished for each microwave exposure). An exposure of 6 minutes was used 18 times (simulating 1.5 years of microwave sterilization with one 6 minute exposure monthly). Reflectance values were measured by spectrophotometer. Three- and two-way analyses of variance with repeated measures were performed for the color difference (DeltaE*) with the factors of group/color/months, and group/months, respectively. Means were compared by Tukey Honest Significant Difference (HSD) multiple range test calculated at the 0.05 level of significance using SPSS. RESULTS: The trained human eye can detect color changes (DeltaE*) greater than 1.0. Most DeltaE* values of the red pigment group at all intervals and the mixed pigment group at 15- and 18- month intervals increased significantly greater than 1.0 (p < 0.001) compared with the control group. Yellow and burnt sienna groups remained the most color stable over time with DeltaE* values below 0.35. CONCLUSIONS: Lack of color stability of red dry earth pigmented A-2186 silicone maxillofacial elastomers was clinically significant after 12-month exposure to microwave energy as compared with yellow, burnt sienna, and opacified A-2186 dry earth pigments. 相似文献
32.
33.
Bulimia is a distinct diagnostic eating disorder with its most noted manifestation being the rapid ingestion of large quantities of food followed by its elimination through the mouth. Because of the dental implications of highly acidic stomach contents chronically being regurgitated, the dentist is in a unique position to help identify the patient with bulimia. Dental erosion is not only the most easily noted but also the most destructive of the many oral problems caused by bulimia. This report of case describes a preventive dental prosthesis that can be used by the patient with bulimia to protect those teeth that are most affected by dental erosion. The construction of the prosthesis is easily completed with materials in the dental office and provides a great service to the patient with bulimia. 相似文献
34.
Pascale Jolliet Stéphane Nion Gwena?lle Allain-Veyrac L Tilloy-Fenart Dorothée Vanuxeem Vincent Berezowski Roméo Cecchelli 《Pharmacological research》2007,56(1):11-17
PURPOSE: The objective of the current study was to determine the ability of some antiemetic compounds to cross the blood-brain barrier (BBB) and thereby to determine possible side effects of compounds for the central nervous system (CNS). METHODS: We compared the brain penetration of some antiemetic compounds using an in vitro BBB model consisting in brain capillary endothelial cells co-cultured with primary rat glial cells. RESULTS: This study clearly demonstrated that the metopimazine metabolite, metopimazine acid, has a very low brain penetration, lower than metopimazine and even less than the other antiemetic compounds tested in this study. CONCLUSIONS: The poor brain penetration of metopimazine acid, metopimazine biodisponible form, seems very likely related to the clinically observed difference in therapeutic and safety profile. 相似文献
35.
36.
37.
Salwa AlDahlawi BDS MSc ; Ameneh Eslami MD ; Lari Häkkinen DDS PhD ; Hannu S. Larjava DDS PhD 《Wound repair and regeneration》2006,14(3):289-297
The alphavbeta6 integrin is an exclusively epithelial integrin that is highly expressed during fetal development. In adult tissue, alphavbeta6 integrin is expressed during inflammation, carcinogenesis, and in wound healing. We previously reported that alphavbeta6 integrin is highly expressed in poorly healing human wounds and its over-expression is associated with chronic wounds in a mouse model. The objective of this study was to investigate the role of alphavbeta6 integrin in compromised wound healing induced by hydrocortisone treatment or aging by using young and old mice deficient in or overexpressing the beta6 integrin subunit in the epidermis. Untreated aged beta6 integrin-deficient (beta6-/-) animals showed a significant delay in wound healing when compared to their age-matched controls or younger beta6-/- mice. The most significant delay was observed at the stages where granulation tissue deposition was occurring. Hydrocortisone treatment significantly delayed wound healing in wild-type and beta6 integrin-deficient mice in comparison with the untreated controls. However, hydrocortisone treatment in beta6 integrin overexpressing animals did not cause a significant delay in wound healing. The results of this study suggest that alphavbeta6 integrin plays an important role in wound healing in animals compromised by either age or stress mimicked by hydrocortisone. 相似文献
38.
Major progress in clinical pain assessment and management has been achieved in the last decade. More effective analgesic drugs and improved techniques for pain management have been introduced. However, medical reports published during the last few years on postoperative pain management (POPM) indicate that moderate or even severe pain is still rather commonly experienced by surgical patients in the early postoperative period and that worst-pain-episodes may occur even in the late postoperative phase. Insufficient relief of postoperative pain seems a more common problem on surgical wards than on a postanaesthesia care unit (PACU). The aims of POPM are to inhibit autonomic trauma-induced nociceptive impulses that may result in functional disturbances of vital organs and thereby affect the incidence of potentially severe complications influencing clinical outcome. Considering that recent studies continue to show sub-optimal pain management despite the availability of effective drugs and analgesic techniques it must be considered essential to identify possible barriers to effective pain management in clinical practice so that necessary improvements in POPM routines can be carried out. 相似文献
39.
Eric T. Stoopler DMD res Pinto DMD Faizan Alawi DDS Sree Raghavendra DMD Ricardo Boyce Jr. DDS David Porter MD Thomas P. Sollecito DMD 《Special care in dentistry》2004,24(2):65-69
Acute myelogenous leukemia (AMU is a hematologic disorder that is characterized by an abnormal proliferation of immature myeloid cells. Granulocytic sarcomas are clusters of leukemic myeloid cells that may develop as a result of AML. Oral manifestations of AML are common and often involve enlargements of the gingiva and/or mucosal tissue from direct leukemia cell infiltration. We describe the case history of a 50-year-old man who had an ulcera-tive lesion of the oral mucosa that was determined to be a granulocytic sarcoma of AML-M0 subtype. The combination of both the subtype and clinical presentation of the leukemia makes this presentation unusual, and to the best of our knowledge, of a type that has not been previously reported in the literature. 相似文献
40.
François Lavigne P. Culpan T. Judet P. Piriou 《European journal of orthopaedic surgery & traumatology : orthopedie traumatologie》2009,19(5):321-325
Objective Stiffness and severe deformity pose a major challenge in total knee arthroplasty. Numerous techniques have been described
to gain exposure and improve knee flexion. Tibial tubercle osteotomy provides excellent and safe exposure of the joint, although
mechanical and wound complications have been reported.
Materials and methods We present a series of 32 consecutive complex primary total replacements where an osteotomy of the tibial tubercle was utilised.
Results The patients had a mean follow-up of 2 years and 11 months. Following the procedure, with the exception of one case complicated
with deep infection, all of the patients had improved clinically. The mean postoperative range of motion had increased to
102° (give P value < 0.005) and there were no cases of delayed union or non-union. A mechanical complication related to technique occurred
in one patient; there were no other cases with a postoperative extension lag.
Conclusion In this challenging population group, we have found a tibial tubercle tuberosity osteotomy to greatly facilitate exposure
without compromising the clinical and radiographic outcome. 相似文献