全文获取类型
收费全文 | 2500810篇 |
免费 | 203006篇 |
国内免费 | 4769篇 |
专业分类
耳鼻咽喉 | 36046篇 |
儿科学 | 76312篇 |
妇产科学 | 65568篇 |
基础医学 | 351354篇 |
口腔科学 | 70235篇 |
临床医学 | 228259篇 |
内科学 | 494465篇 |
皮肤病学 | 50246篇 |
神经病学 | 213807篇 |
特种医学 | 100183篇 |
外国民族医学 | 895篇 |
外科学 | 378173篇 |
综合类 | 58009篇 |
现状与发展 | 4篇 |
一般理论 | 1157篇 |
预防医学 | 200552篇 |
眼科学 | 59112篇 |
药学 | 185589篇 |
4篇 | |
中国医学 | 4507篇 |
肿瘤学 | 134108篇 |
出版年
2018年 | 26461篇 |
2017年 | 20390篇 |
2016年 | 22516篇 |
2015年 | 25653篇 |
2014年 | 36968篇 |
2013年 | 56467篇 |
2012年 | 76533篇 |
2011年 | 80765篇 |
2010年 | 47175篇 |
2009年 | 45305篇 |
2008年 | 76749篇 |
2007年 | 81700篇 |
2006年 | 82195篇 |
2005年 | 80518篇 |
2004年 | 77608篇 |
2003年 | 74850篇 |
2002年 | 73813篇 |
2001年 | 113492篇 |
2000年 | 117328篇 |
1999年 | 99460篇 |
1998年 | 29562篇 |
1997年 | 26944篇 |
1996年 | 26680篇 |
1995年 | 25741篇 |
1994年 | 24163篇 |
1993年 | 22533篇 |
1992年 | 80108篇 |
1991年 | 77077篇 |
1990年 | 74167篇 |
1989年 | 71423篇 |
1988年 | 66435篇 |
1987年 | 65315篇 |
1986年 | 61932篇 |
1985年 | 59068篇 |
1984年 | 45114篇 |
1983年 | 38506篇 |
1982年 | 24097篇 |
1981年 | 21473篇 |
1980年 | 20109篇 |
1979年 | 41885篇 |
1978年 | 29681篇 |
1977年 | 24973篇 |
1976年 | 23379篇 |
1975年 | 24383篇 |
1974年 | 30111篇 |
1973年 | 28396篇 |
1972年 | 26525篇 |
1971年 | 24365篇 |
1970年 | 22940篇 |
1969年 | 21251篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
993.
994.
C. Oprea P.J. Szalanski M.V. Gustova I.A. Oprea V. Buzguta 《Applied radiation and isotopes》2009,67(12):2142-2145
R-mode factor analysis was applied to characterize the chemical composition of human teeth investigated by particle induced X-ray emission (PIXE), Rutherford backscattering spectrometry (RBS) and X-ray fluorescence (XRF) techniques. The approach developed in this study enabled the separation between essential mineral teeth components and the pollutants deposited in teeth tissues during the human life. The three independent sources of metals incorporated in human teeth were found. The first source, representing about 43% of the variance of the concentration data, was characterized by pollutant elements of power industry emissions. The second factor was loaded with toxic elements of general urban pollution. The third factor represented the tooth source as it contained mainly large fractions of the mineral components of the tooth tissue as Ca and K. 相似文献
995.
L.J. Mackintosh† M.N.C. de Koning‡ W.G.V. Quint‡ J. ter Schegget‡ I.M. Morgan R.M. Herd† M.S. Campo 《The British journal of dermatology》2009,161(1):56-62
Background Nonmelanoma skin cancer (NMSC) has been linked to cutaneous human papillomaviruses of the genus beta (betaPV).
Objectives We sought to assess the presence of betaPV in NMSC biopsies from a group of Scottish skin cancer patients, both immunocompetent (IC) patients and immunosuppressed (IS) organ transplant recipients.
Methods One hundred and twenty-one paraffin-embedded skin tumours (27 actinic keratosis, 41 intraepidermal carcinoma, 53 squamous cell carcinoma) and 11 normal skin samples were analysed for the presence of betaPV by a polymerase chain reaction–reverse hybridization assay designed to detect the presence of the 25 known betaPV genotypes.
Results In IC patients, betaPV was detected in 30 of 59 (51%) tumours and two of 11 (18%) normal skin samples ( P = 0·046). In IS patients, betaPV was found in 27 of 62 (44%) tumours; no normal skin samples were available for comparison. The most frequently found genotypes were HPV-24, HPV-15 and HPV-38. Of those tumours infected with betaPV, 28 of 57 (49%) were infected with more than one genotype (range 2–8). Tumours from IS patients were from a younger age group (mean age 57·4 years) than IC patients (mean age 73·8 years). Multiple infections were more common in tumours from IC patients (21 of 30; 70%) compared with those from IS patients (seven of 27; 26%) ( P < 0·001). In the IC group, age did not appear to influence the distribution of single and multiple infections whereas in IS patients the proportion of multiple infections to single infections increased with age. There were no multiple infections in normal skin.
Conclusions A wide spectrum of betaPV types was detected in our samples. Further characterization of betaPV in vivo is needed in order to determine the mechanisms by which the virus contributes to cutaneous carcinogenesis. 相似文献
Objectives We sought to assess the presence of betaPV in NMSC biopsies from a group of Scottish skin cancer patients, both immunocompetent (IC) patients and immunosuppressed (IS) organ transplant recipients.
Methods One hundred and twenty-one paraffin-embedded skin tumours (27 actinic keratosis, 41 intraepidermal carcinoma, 53 squamous cell carcinoma) and 11 normal skin samples were analysed for the presence of betaPV by a polymerase chain reaction–reverse hybridization assay designed to detect the presence of the 25 known betaPV genotypes.
Results In IC patients, betaPV was detected in 30 of 59 (51%) tumours and two of 11 (18%) normal skin samples ( P = 0·046). In IS patients, betaPV was found in 27 of 62 (44%) tumours; no normal skin samples were available for comparison. The most frequently found genotypes were HPV-24, HPV-15 and HPV-38. Of those tumours infected with betaPV, 28 of 57 (49%) were infected with more than one genotype (range 2–8). Tumours from IS patients were from a younger age group (mean age 57·4 years) than IC patients (mean age 73·8 years). Multiple infections were more common in tumours from IC patients (21 of 30; 70%) compared with those from IS patients (seven of 27; 26%) ( P < 0·001). In the IC group, age did not appear to influence the distribution of single and multiple infections whereas in IS patients the proportion of multiple infections to single infections increased with age. There were no multiple infections in normal skin.
Conclusions A wide spectrum of betaPV types was detected in our samples. Further characterization of betaPV in vivo is needed in order to determine the mechanisms by which the virus contributes to cutaneous carcinogenesis. 相似文献
996.
997.
Robert N. Page Lee Dittrich Roy King Fouad Boulos David L. Page 《Journal of cutaneous pathology》2009,36(11):1206-1209
Originally described by Rosen in 1983, syringomatous nipple adenoma (SAN) is a tumor of disputed histogenesis, which can be problematic both diagnostically and therapeutically. 1 It is a benign primary tumor of breast epithelium with histology similar to that of the syringoma. In the current case, we describe a 40-year-old female with this lesion occurring within a supernumerary breast. This case represents, to our knowledge, the first such reported case, and represents a significant finding as its presence could lend some confusion as to whether or not this represents a benign primary process of breast or a potentially infiltrative tumor of the skin. 相似文献
998.
Several cases of relapsing attacks during which the ear becomes red and patients experience a burning sensation have been reported in the literature. This combination of symptoms has been described as ‘red ear syndrome’ (RES). We report on a 7‐year‐old boy who had episodes of reddening, swelling and a burning sensation in one ear with local hyperthermia persisting for 3 years. The differential diagnosis included RES and erythromelalgia, as isolated auricular variants of erythromelalgia have been described and the symptoms are difficult to distinguish from RES. In this report, we discuss the similarities and differences between RES and erythromelalgia. 相似文献
999.
L. TIMMER-DE MIK M.D. D.M. BROEKHUIJSEN-VAN HENTEN M.D. † J.M. OLDHOFF M.D. PH.D. D.B. DE GEER M.D. ‡ V. SIGURDSSON M.D. PH.D. S.G.M.A. PASMANS M.D. PH.D. 《Pediatric dermatology》2009,26(3):358-360
Abstract: In Sweet's syndrome, the essential features are the characteristic morphology of the lesions, their histologic appearance, the dramatic response to corticosteroids and the absence of scarring. We report an 8-month-old infant in whom Sweet's syndrome was diagnosed and who developed acquired cutis laxa in the skin lesions. 相似文献
1000.
H. J. J. Kars Juha M. Hijmans Jan H. B. Geertzen Wiebren Zijlstra 《Journal of diabetes science and technology》2009,3(4):931-943
The objective of this review is to identify and review publications describing the impact of reduced somatosensation on balance. Based on knowledge of the association between specific somatosensory loss and deterioration of balance, conclusions can be made about role of somatosensation in standing balance.A systematic literature review is presented in which publications from the years 1993 through 2007 were searched in Medline and Embase. Medical Subject Headings (MESH) terms and free text words (related to balance, somatosensory loss, and lower limb) were used to perform the searches. Fifteen articles were selected for detailed review based on predetermined inclusion criteria, and three of the included articles described the effect of experimentally reduced somatosensation on balance in healthy subjects. Ten of the articles described balance in diabetic neuropathy (DN). The last two included articles described balance in Charcot-Marie-Tooth (CMT) disease type 1A (CMT1A) or type 2 (CMT2).The literature indicates that the tactile sensation is reduced in DN, CMT1A, and CMT2 and when the plantar surface of the feet was hypothermically anesthetized. Joint motion sensation seems to be impaired in patients with DN, and passive joint position sensation appears to be reduced in healthy subjects with anesthesia of ankle and foot from prolonged ischemia. This reduced somatosensation seems to have a negative effect on balance in patients with DN and CMT2; however, this appeared not to be the case in patients with CMT1A and in healthy subjects. 相似文献