全文获取类型
收费全文 | 41718篇 |
免费 | 6892篇 |
国内免费 | 346篇 |
专业分类
耳鼻咽喉 | 1374篇 |
儿科学 | 2130篇 |
妇产科学 | 1452篇 |
基础医学 | 1733篇 |
口腔科学 | 3823篇 |
临床医学 | 5882篇 |
内科学 | 8555篇 |
皮肤病学 | 968篇 |
神经病学 | 3283篇 |
特种医学 | 1832篇 |
外国民族医学 | 1篇 |
外科学 | 8104篇 |
综合类 | 601篇 |
现状与发展 | 12篇 |
一般理论 | 10篇 |
预防医学 | 3376篇 |
眼科学 | 984篇 |
药学 | 1357篇 |
5篇 | |
中国医学 | 171篇 |
肿瘤学 | 3303篇 |
出版年
2024年 | 245篇 |
2023年 | 1416篇 |
2022年 | 635篇 |
2021年 | 1155篇 |
2020年 | 1633篇 |
2019年 | 953篇 |
2018年 | 2221篇 |
2017年 | 2012篇 |
2016年 | 2386篇 |
2015年 | 2282篇 |
2014年 | 3011篇 |
2013年 | 3735篇 |
2012年 | 2116篇 |
2011年 | 2277篇 |
2010年 | 2363篇 |
2009年 | 2542篇 |
2008年 | 1785篇 |
2007年 | 1590篇 |
2006年 | 1753篇 |
2005年 | 1508篇 |
2004年 | 1321篇 |
2003年 | 1217篇 |
2002年 | 1173篇 |
2001年 | 952篇 |
2000年 | 883篇 |
1999年 | 807篇 |
1998年 | 657篇 |
1997年 | 611篇 |
1996年 | 646篇 |
1995年 | 439篇 |
1994年 | 353篇 |
1993年 | 295篇 |
1992年 | 214篇 |
1991年 | 192篇 |
1990年 | 171篇 |
1989年 | 166篇 |
1988年 | 142篇 |
1987年 | 143篇 |
1986年 | 110篇 |
1985年 | 98篇 |
1984年 | 89篇 |
1983年 | 102篇 |
1982年 | 89篇 |
1981年 | 75篇 |
1980年 | 48篇 |
1979年 | 41篇 |
1978年 | 40篇 |
1977年 | 47篇 |
1976年 | 34篇 |
1975年 | 33篇 |
排序方式: 共有10000条查询结果,搜索用时 12 毫秒
81.
Taking occlusal photographs can be challenging; they are by far the most difficult images to obtain. Achieving an ideal photograph of every arch may not always be possible. In patients with limited range of motion of the mandible, an oversized or hyperactive tongue, an excessive gag reflex, or reduced flexibility of lips and checks, the goal of an ideal occlusal photograph may not be achieved. Nevertheless, patience, practice, and attention to detail can often provide a satisfactory result. 相似文献
82.
Robert L. Kriel MD Linda E. Krach MD Martha M. Bergland MS Laurel A. Panser MS 《Pediatric neurology》1988,4(6):337-341
This report describes the outcomes of 28 children who had severe head injuries between 13–18 years of age. All were unconscious at least 24 hours and have been followed at least 2 years after injury. At present, their ages range from 18 to 27 years. Their educational achievements, social activities, marital status, functional independence, and employment at follow-up are described. 相似文献
83.
Can nurses practice caring within a healthcare system that promotes codependency? Caring promotes mutual empowerment of all participants while codependent caring disempowers. Nurses are expected to practice caring with clients, The authors contend, however, that nursing, as historically and currently practiced within bureaucratic/patriarchal organizations, is founded on a vlue system that fosters codependency. Until nursing is practiced within the context of caring organizations and a caring healthcare system, nurses will continue to be powerless to shape their own practice as carers and burnout will continue to be a problem. 相似文献
84.
Summary A method of dermaplaning for acne scarring using a skin graft knife is described. This surgical technique cannot be considered as a form of dermabrasion. Its advantages are reported. 相似文献
85.
S. van Ruth† EBL van Dorst‡ MR Canninga-van Dijk§ MS de Bruin-Weller† 《Journal of the European Academy of Dermatology and Venereology》2007,21(5):678-680
Cutaneous metastasis of vaginal carcinoma is extremely rare. So far, the total number of reported skin metastasis of vaginal carcinoma is only one. We present another case with an unusual manifestation of vagina carcinoma metastasis: skin metastasis presenting as a leg ulcer on the lower leg. 相似文献
86.
Tadashi Nomura MD ; Hiroto Terashi MD PhD ; Makoto Omori MD ; Atsushi Sakurai MD ; Takeru Sunagawa PhD ; Masumi Hasegawa MS ; Shinya Tahara MD PhD 《Wound repair and regeneration》2007,15(6):833-837
Hypertrophic scars (HS) are a consequence of abnormal wound healing. We examined fatty acids that are contained within, and participate in, every reaction through the membrane; then, we analyzed the percentage composition of the fatty acids in deepithelialized normal dermis (ND) and HS. In vivo HS samples were obtained from six patients undergoing surgical excision, and ND samples from five patients undergoing skin grafting surgery for excess. In vitro, cultured fibroblasts from HS and ND were also analyzed. The percentage composition of fatty acids extracted from all the samples was analyzed. In vivo, arachidonic acid (20:4) was significantly more abundant in HS than in ND, in the phospholipids from both whole tissue and cell membranes. In vitro, there were no significant differences among ND, HS, and 10% fetal calf serum. The results suggest that HS formation does not necessarily involve simple excess of 20:4; however, there are considerable differences in the percentage composition of 20:4 between ND and HS. Arachidonic acid probably participates in the formation and maintenance of HS, whereas in vitro cultured fibroblasts are affected largely by fetal calf serum. 相似文献
87.
88.
Kevin J. Donly DDS MS 《Journal of esthetic and restorative dentistry : official publication of the American Academy of Esthetic Dentistry ... [et al.]》2005,17(6):380-380
The popularity of vital tooth whitening has increased significantly over the past two decades. Professionally supervised "in-office" and "at-home" tooth whitening methods have been documented in the literature with evidence of safety and effectiveness. Although the literature includes considerable information about vital tooth whitening in adults, minimal information is available concerning vital tooth whitening in children and adolescents.
The need to provide vital tooth whitening for children might be infrequent owing to the natural whiteness of children's teeth. However, there are circumstances when tooth whitening can be desirable for children, such as fluorosis discoloration, generalized tooth darkening, post-traumatic injury discoloration, and postorthodontic tooth discoloration.
Few well-controlled clinical trials evaluating the safety and effectiveness of vital tooth whitening in children are available in the literature, Furthermore, these published clinical trials were carried out by the same principal investigator. This review examines these trials and offers recommendations accordingly. 相似文献
The need to provide vital tooth whitening for children might be infrequent owing to the natural whiteness of children's teeth. However, there are circumstances when tooth whitening can be desirable for children, such as fluorosis discoloration, generalized tooth darkening, post-traumatic injury discoloration, and postorthodontic tooth discoloration.
Few well-controlled clinical trials evaluating the safety and effectiveness of vital tooth whitening in children are available in the literature, Furthermore, these published clinical trials were carried out by the same principal investigator. This review examines these trials and offers recommendations accordingly. 相似文献
89.
Vlad C. Sandulache PhD ; Aron Parekh PhD ; HaSheng Li-Korotky MD PhD ; Joseph E. Dohar MD MS ; Patricia A. Hebda PhD 《Wound repair and regeneration》2007,15(1):122-133
Keloid formation has been linked to aberrant fibroblast activity, exacerbated by growth factors and inflammatory mediators. Prostaglandin E2 (PGE2), synthesized from arachidonic acid by cyclooxygenases (COX) and synthases (PGES), acts as both an inflammatory mediator and fibroblast modulator. Although PGE2 has known antifibrotic effects in the lower airway, its role in dermal fibrosis in general, and keloid formation in particular, remains unclear. This study focused on: (1) the effects of PGE2 on keloid fibroblast migration, contraction, and collagen synthesis and (2) endogenous PGE2 synthesis in response interleukin-1beta. PGE2 decreased keloid fibroblast migration and contraction via an EP2/EP4-cAMP mechanism that disrupted actin cytoskeletal dynamics and reversed transforming growth factor-beta1-induced collagen I and III synthesis. Impaired fibroblast PGE2 production has been linked to lower airway fibrosis and recently to keloid formation. Here, we showed that interleukin-1beta stimulation leads to nuclear factor-kappaB translocation to the nucleus, resulting in up-regulation of COX-2 and microsomal PGE2 synthase 1. Up-regulation of COX-2 in, and secretion of PGE2 by keloid fibroblasts are diminished compared with their normal fibroblast counterparts. We suggest that the antifibrotic effects of PGE2 during keloid formation are potentially diminished due to aberrant paracrine fibroblast signaling. Exogenous PGE2 may supplement decreased endogenous levels and inhibit keloid formation or progression. 相似文献
90.
Solish Nowell MD Benohanian Antranik MD Jonathan W. Kowalski PharmD MS on Behalf of the Canadian Dermatology Study Group on Health-Related Quality of Life in Primary Axillary Hyperhidrosis 《Dermatologic surgery》2005,31(4):405-413
BACKGROUND: Patients with primary axillary hyperhidrosis experience substantial functional impairment and reduced health-related quality of life (HRQOL). Few studies have comprehensively evaluated the effects of botulinum toxin type A (BoNT-A) on these symptoms. OBJECTIVE: To prospectively assess the effects of BoNT-A on functional impairment associated with primary axillary hyperhidrosis. METHODS: Patients treated with BoNT-A 50 U per axilla at baseline were assessed 4 and 12 weeks later. Outcome measures included functional impairment as assessed by the Hyperhidrosis Disease Severity Scale and the Hyperhidrosis Impact Questionnaire and dermatology-specific HRQOL as assessed by the Dermatology Life Quality Index. RESULTS: At weeks 4 and 12 after BoNT-A treatment, 85% and 90% of patients achieved the a priori definition of treatment responder. Patients reported less occupational and emotional impairment, spent less time managing their hyperhidrosis, and had fewer difficulties in social situations. Adverse events were uncommon (5.5%), were mild, and did not require treatment. At study end, 53% of patients reported no dermatology-specific HRQOL impairment and 90% were satisfied with treatment. CONCLUSIONS: Significant, meaningful, rapid, and durable reductions in disease severity and functional impairment, as well as improvements in HRQOL, were seen following BoNT-A treatment. BoNT-A was safe and well tolerated, producing high levels of patient satisfaction. 相似文献