全文获取类型
收费全文 | 1989篇 |
免费 | 116篇 |
国内免费 | 40篇 |
专业分类
耳鼻咽喉 | 22篇 |
儿科学 | 125篇 |
妇产科学 | 32篇 |
基础医学 | 228篇 |
口腔科学 | 63篇 |
临床医学 | 155篇 |
内科学 | 446篇 |
皮肤病学 | 64篇 |
神经病学 | 116篇 |
特种医学 | 216篇 |
外科学 | 196篇 |
综合类 | 29篇 |
预防医学 | 185篇 |
眼科学 | 33篇 |
药学 | 110篇 |
中国医学 | 3篇 |
肿瘤学 | 122篇 |
出版年
2023年 | 7篇 |
2022年 | 8篇 |
2021年 | 37篇 |
2020年 | 21篇 |
2019年 | 40篇 |
2018年 | 44篇 |
2017年 | 52篇 |
2016年 | 45篇 |
2015年 | 41篇 |
2014年 | 58篇 |
2013年 | 94篇 |
2012年 | 102篇 |
2011年 | 96篇 |
2010年 | 75篇 |
2009年 | 78篇 |
2008年 | 74篇 |
2007年 | 87篇 |
2006年 | 79篇 |
2005年 | 100篇 |
2004年 | 68篇 |
2003年 | 60篇 |
2002年 | 59篇 |
2001年 | 47篇 |
2000年 | 53篇 |
1999年 | 58篇 |
1998年 | 64篇 |
1997年 | 50篇 |
1996年 | 58篇 |
1995年 | 39篇 |
1994年 | 48篇 |
1993年 | 41篇 |
1992年 | 24篇 |
1991年 | 39篇 |
1990年 | 21篇 |
1989年 | 37篇 |
1988年 | 56篇 |
1987年 | 32篇 |
1986年 | 23篇 |
1985年 | 37篇 |
1984年 | 7篇 |
1982年 | 8篇 |
1981年 | 9篇 |
1980年 | 9篇 |
1979年 | 9篇 |
1978年 | 6篇 |
1977年 | 8篇 |
1976年 | 15篇 |
1975年 | 4篇 |
1972年 | 2篇 |
1971年 | 3篇 |
排序方式: 共有2145条查询结果,搜索用时 15 毫秒
1.
The use of endogenous Protoporphyrin IX generated through the heme biosynthetic pathway after administration of 5-aminolevulinic acid (ALA) has led to many applications in photodynamic therapy (PDT). In Buenos Aires, Argentina, the Centro de Investigaciones sobre Porfirinas y Porfirias (CIPYP), reported for the first time, in 1975, porphyrin synthesis from ALA in highly dividing plant tissues. Increased porphyrin synthesis in tumours as well as cell photosensitisation was reported soon after. Our group is also interested in studying the use of new synthetic lipophilic derivatives of ALA as well as ALA delivery in liposomes. We have elucidated the mechanism of ALA transport in mammalian and yeast cells. The interactions between ALA-PDT and nitric oxide were investigated in three murine adenocarcinoma cell lines. In the National University of Río Cuarto, Córdoba, a group is devoted to the synthesis of new porphyrin-derived photosensitisers to study their effects on photoinactivation of bacterial and mammalian cells death by PDT. At the Centre of Electron Microscopy of the Cordoba National University, a prototype of a 630 nm noncoherent light source was designed and constructed. Cost of the light source and scarce knowledge of the benefits of PDT by physicians limit the spread of the treatment throughout the country. 相似文献
2.
3.
J. M. Troyano M. T. Clavijo A. Gonzalez-Lorenzo I. Martí nez-Wallin O. Y. Marco P. S. Casas L. Martí nez-Cort s L. T. Merc J. Bajo-Arenas N. Hernandez D. Castro 《The Ultrasound Review of Obstetrics & Gynecology》2006,6(1):79-99
In order to assess the state and pathology of the woman's pelvis minor, a number of methods are commonly used among practitioners, encompassing clinical exploration, radiology, MRN, urodynamics, endoscopy and echography.
Echography has been poorly used in clinical pelvic exploration and its reliability is actually a matter of controversy 1. However, echographic surveys can provide us with valuable gynecological data on the state and pathologies of the soft pelvis, within the genital regions or even going beyond them, i.e. the rectal channel, bladder, urethra, anus, vascular plexuses, and all of their supporting tissues.
At our research unit, we have been employing Transvaginal Ultrasound echography (TVU) for a long time in conjunction with other pelvis-focused methods in order to study different kinds of pelvic alterations. TVU has proven to be friendly to use, fast, harmless and inexpensive, allowing serial explorations and producing high-quality dynamic images (loop-cinema, video-tape). Furthermore, this method is fairly aseptic in that the occurrence of faeces in the rectal ampolla is not a nuisance but a bonus in tracking the contours of the rectum walls and other topographical features which would be otherwise difficult to survey.
A complete pelvic floor TVU may add no longer than 5-8 minutes to a routine gynecological examination, can be implemented by the general gynecologist and generates data that can be further studied by the appropriate specialist for a more insightful evaluation 2. 相似文献
Echography has been poorly used in clinical pelvic exploration and its reliability is actually a matter of controversy 1. However, echographic surveys can provide us with valuable gynecological data on the state and pathologies of the soft pelvis, within the genital regions or even going beyond them, i.e. the rectal channel, bladder, urethra, anus, vascular plexuses, and all of their supporting tissues.
At our research unit, we have been employing Transvaginal Ultrasound echography (TVU) for a long time in conjunction with other pelvis-focused methods in order to study different kinds of pelvic alterations. TVU has proven to be friendly to use, fast, harmless and inexpensive, allowing serial explorations and producing high-quality dynamic images (loop-cinema, video-tape). Furthermore, this method is fairly aseptic in that the occurrence of faeces in the rectal ampolla is not a nuisance but a bonus in tracking the contours of the rectum walls and other topographical features which would be otherwise difficult to survey.
A complete pelvic floor TVU may add no longer than 5-8 minutes to a routine gynecological examination, can be implemented by the general gynecologist and generates data that can be further studied by the appropriate specialist for a more insightful evaluation 2. 相似文献
4.
M Ardigo I Malizewsky ML Dell'Anna E Berardesca M Picardo 《Journal of the European Academy of Dermatology and Venereology》2007,21(10):1344-1350
BACKGROUND: Vitiligo is the most common pigmentary disorder with a global incidence from 0.1% to 2% in different geographical areas. Histopathology and histochemistry have shown the reduction of melanocytes in achromic patches, but microscopic changes of lesional and non-lesional skin are still not completely understood. Reflectance confocal microscopy (RCM), based on the different light reflectance index of cutaneous structures, allowed in vivo, en face microscopic evaluation of superficial skin layers with a resolution similar to skin histology. AIM: The purpose of this study was to evaluate RCM features of lesional and non-lesional skin of vitiligo patients. Moreover, re-pigmented areas were taken into consideration in order to evaluate melanocyte response to ultraviolet B (UVB) radiation. SUBJECTS AND METHODS: Sixteen patients of different phototypes affected by active non-segmental vitiligo and 10 controls were enrolled in the study. In vivo skin imaging was done using a commercially available RCM (Lucid, Vivascope 1500. Re-pigmented areas from 6 to 16 patients (after UVB narrow-band therapy) were also examined. RESULTS: Vitiligo lesions showed the disappearance of the bright rings normally seen at the dermo-epidermal junction. Moreover, non-lesional skin of vitiligo patients showed unexpected changes as the presence of half-rings or scalloped border-like features of the bright papillary rings. In re-pigmented areas after UVB narrow band therapy, the presence of activated, dendritic melanocytes was seen. CONCLUSIONS: Considering our results, and following further studies, RCM clinical applications could be used in the therapeutic monitoring and evaluation of the evolution of vitiligo. 相似文献
5.
6.
Ana Martín-Ancel María Luisa Casas Bartolomé Bonet 《Infection control and hospital epidemiology》2004,25(7):611-613
A neonate vaccinated against HBV was the source of an occupational exposure to blood. She was tested for hepatitis B surface antigen and found to be positive, leading to unnecessary treatment, retesting, and concern. Evaluation of the infectious status of HBV should rely on other means if vaccination has recently occurred. 相似文献
7.
8.
Buried inferiorly based gluteus maximus musculocutaneous flap for reconstruction of large, recurrent ischiopubic pressure sores 总被引:1,自引:0,他引:1
The ischium is the most common site for recurrence of pressure sores in the paraplegic population. Successful reconstruction of these wounds depends on the total excision of ulcer, soft tissue debris, bony prominence, and the durability of the soft tissue repair. The V-Y gluteus maximum musculocutaneous flap based on the inferior gluteal vessels can be advanced medially, deepithelialized, and buried to fill large, deep soft tissue ischial wounds. Local rotational flaps close the superficial wound. This buried flap, although not previously described, is useful for the reconstruction of large ischiopubic pressure sores initially or at the time of recurrence. 相似文献
9.
10.
Kinnison ML; Perler BA; Kaufman SL; Mitchell SE; Kadir S; Williams GM; White RI Jr 《Radiology》1986,160(3):727-730
In situ saphenous vein grafts are being used with increasing frequency for bypass procedures involving the femoral and popliteal arteries. Complications of these procedures include anastomotic stenoses and persistent arteriovenous fistulae that may result in failure of the graft. Balloon angioplasty and embolotherapy with detachable balloons were employed successfully in three or four recent cases of patients with complications from in situ grafts. Tailored angiography is essential for evaluating in situ grafts, and interventional techniques are extremely useful for managing complications. 相似文献