全文获取类型
收费全文 | 2119篇 |
免费 | 105篇 |
国内免费 | 22篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 156篇 |
妇产科学 | 21篇 |
基础医学 | 191篇 |
口腔科学 | 47篇 |
临床医学 | 194篇 |
内科学 | 609篇 |
皮肤病学 | 24篇 |
神经病学 | 66篇 |
特种医学 | 481篇 |
外科学 | 174篇 |
综合类 | 29篇 |
预防医学 | 93篇 |
眼科学 | 16篇 |
药学 | 68篇 |
中国医学 | 3篇 |
肿瘤学 | 73篇 |
出版年
2022年 | 5篇 |
2021年 | 12篇 |
2020年 | 11篇 |
2019年 | 9篇 |
2018年 | 18篇 |
2017年 | 12篇 |
2016年 | 22篇 |
2015年 | 32篇 |
2014年 | 37篇 |
2013年 | 68篇 |
2012年 | 38篇 |
2011年 | 50篇 |
2010年 | 95篇 |
2009年 | 76篇 |
2008年 | 81篇 |
2007年 | 55篇 |
2006年 | 61篇 |
2005年 | 44篇 |
2004年 | 35篇 |
2003年 | 46篇 |
2002年 | 37篇 |
2001年 | 38篇 |
2000年 | 40篇 |
1999年 | 43篇 |
1998年 | 134篇 |
1997年 | 126篇 |
1996年 | 127篇 |
1995年 | 95篇 |
1994年 | 79篇 |
1993年 | 84篇 |
1992年 | 27篇 |
1991年 | 37篇 |
1990年 | 25篇 |
1989年 | 68篇 |
1988年 | 54篇 |
1987年 | 60篇 |
1986年 | 51篇 |
1985年 | 50篇 |
1984年 | 28篇 |
1983年 | 32篇 |
1982年 | 35篇 |
1981年 | 23篇 |
1980年 | 37篇 |
1979年 | 14篇 |
1978年 | 15篇 |
1977年 | 19篇 |
1976年 | 24篇 |
1975年 | 25篇 |
1966年 | 2篇 |
1938年 | 2篇 |
排序方式: 共有2246条查询结果,搜索用时 171 毫秒
101.
Sven Goetstouwers Dagmar Kempink Bertram The Denise Eygendaal Bart van Oirschot Christiaan JA van Bergen 《World journal of orthopedics》2022,13(1):1-10
Three-dimensional (3D) printing is a rapidly evolving and promising field to improve outcomes of orthopaedic surgery. The use of patient-specific 3D-printed models is specifically interesting in paediatric orthopaedic surgery, as limb deformity corrections often require an individual 3D treatment. In this editorial, various operative applications of 3D printing in paediatric orthopaedic surgery are discussed. The technical aspects and the imaging acquisition with computed tomography and magnetic resonance imaging are outlined. Next, there is a focus on the intraoperative applications of 3D printing during paediatric orthopaedic surgical procedures. An overview of various upper and lower limb deformities in paediatrics is given, in which 3D printing is already implemented, including post-traumatic forearm corrections and proximal femoral osteotomies. The use of patient-specific instrumentation (PSI) or guiding templates during the surgical procedure shows to be promising in reducing operation time, intraoperative haemorrhage and radiation exposure. Moreover, 3D-printed models for the use of PSI or patient-specific navigation templates are promising in improving the accuracy of complex limb deformity surgery in children. Lastly, the future of 3D printing in paediatric orthopaedics extends beyond the intraoperative applications; various other medical applications include 3D casting and prosthetic limb replacement. In conclusion, 3D printing opportunities are numerous, and the fast developments are exciting, but more evidence is required to prove its superiority over conventional paediatric orthopaedic surgery. 相似文献
102.
Barbara Uhl Katharina T Prochazka Karoline Fechter Katrin Pansy Hildegard T Greinix Peter Neumeister Alexander JA Deutsch 《World journal of gastrointestinal oncology》2022,14(1):153-162
Approximately 8% of all non-Hodgkin lymphomas are extranodal marginal zone B cell lymphomas of mucosa-associated lymphoid tissue (MALT), also known as MALT lymphomas. These arise at a wide range of different extranodal sites, with most cases affecting the stomach, the lung, the ocular adnexa and the thyroid. The small intestine is involved in a lower percentage of cases. Lymphoma growth in the early stages is associated with long-lasting chronic inflammation provoked by bacterial infections (e.g., Helicobacter pylori or Chlamydia psittaci infections) or autoimmune conditions (e.g., Sjögren’s syndrome or Hashimoto thyroiditis). While these inflammatory processes trigger lymphoma cell proliferation and/or survival, they also shape the microenvironment. Thus, activated immune cells are actively recruited to the lymphoma, resulting in either direct lymphoma cell stimulation via surface receptor interactions and/or indirect lymphoma cell stimulation via secretion of soluble factors like cytokines. In addition, chronic inflammatory conditions cause the acquisition of genetic alterations resulting in autonomous lymphoma cell growth. Recently, novel agents targeting the microenvironment have been developed and clinically tested in MALT lymphomas as well as other lymphoid malignancies. In this review, we aim to describe the composition of the microenvironment of MALT lymphoma, the interaction of activated immune cells with lymphoma cells and novel therapeutic approaches in MALT lymphomas using immunomodulatory and/or microenvironment-targeting agents. 相似文献
103.
104.
The potential of using the phase derivative (PD) of the radio-frequency echograms for producing 2-dimensional grey scale images was further investigated. The PD images were produced by five different algorithms, which according to the results described in the companion paper yield PD images dominated by the amplitude (envelope, ENV), mixed PD-AM images and pure PD images. These images are termed according to their algorithms: ZCS, zero crossing counter with squelch; ASS, analytic signal with squelch; ASW, analytic signal with Wiener kernel; UNP, unwrapped phase; and SAS, smoothed analytic signal. The rf data were obtained from simulations and from experiments with a tissue mimicking phantom. PD images were analysed by calculation of the first and second order grey level statistics: mean level, signal-to-noise ratio (SNR) and the full width at half maximum (FWHM) of the autocovariance functions (ACVF). These parameters were systematically investigated for a range of depths with respect to the transducer and a range of scatterer densities of the insonated medium. The UNP and SAS images do not suffer much from the diffraction effect but do not display much information about the scatterer density either. The ASW and ASS images qualitatively display beam diffraction effects similar to those of the AM images, with the exception of the mean value which is at the minimum in the focus, where the AM yields a sharp maximum at that depth. The mean and the SNR of the ASW and ASS images increase with increasing scatterer density and saturate at a density of 5000 cm-3. The mean value of the envelope, however, displays a square root dependency over the whole range. The axial and lateral FWHM of the ACVF of the UNP and SAS methods are not significantly dependent on the scatterer density and decrease with increasing density for the ASW and ASS images, as was observed in the envelope images. It may be concluded that ASW and ASS methods produce PD grey scale images which are equally well suited for the diagnosis of diffuse diseases of parenchymal tissues as conventional AM images. The smaller "speckle" size of the ASW images might be advantageous, for the detection of focal lesions, but the lesion contrast is found to be much lower than for the ENV. 相似文献
105.
106.
KAP Meeuwis JA De Hullu MEA De Jager LFAG Massuger PCM Van De Kerkhof MM Van Rossum 《Journal of the European Academy of Dermatology and Venereology》2010,24(12):1425-1430
Background Psoriatic lesions may involve nearly all sites of the body. Involvement of the genital skin is frequently classified as part of intertriginous psoriasis without special awareness and treatment for this presentation of the disease. Gaining knowledge about the frequency of the involvement of genital skin in these patients will improve the overall care for patients with psoriasis. Objectives We studied the prevalence of genital psoriasis in the Netherlands and epidemiological characteristics of this specific presentation of the disease. Furthermore, we studied the relation between flexural and genital psoriasis. Patients/Methods A self‐administered questionnaire was sent to all 5300 members of the Dutch Psoriasis Society. Sociodemographic patient characteristics and disease‐related data (such as localization of psoriatic lesions, involvement of the genitalia, age at onset of genital psoriasis and severity of genital psoriatic lesions) were collected and analysed. Results A response rate of 37% was achieved. Almost 46% of the responding patients with psoriasis, that is 16.5% of all potential responders (n = 5300), report genital involvement at some time during the course of their disease. The genitalia can become affected at any age. Many patients with current genital involvement (38%) do not have the flexural skin affected. Conclusions A large part of patients with psoriasis suffer from genital psoriasis, which was not associated with flexural involvement in at least one third of them. More attention to the genital region is required in the current standard treatment of both male and female psoriatic patients at any age. 相似文献
107.
van Engen Catherine E Ofman Rob Dijkstra Inge ME Schackmann Martin J Wanders Ronald JA Kemp Stephan 《Tijdschrift voor kindergeneeskunde》2013,81(1):10-10
Tijdschrift voor Kindergeneeskunde - 相似文献
108.
109.