全文获取类型
收费全文 | 1097篇 |
免费 | 55篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 12篇 |
儿科学 | 48篇 |
妇产科学 | 13篇 |
基础医学 | 156篇 |
口腔科学 | 60篇 |
临床医学 | 85篇 |
内科学 | 206篇 |
皮肤病学 | 5篇 |
神经病学 | 133篇 |
特种医学 | 44篇 |
外科学 | 166篇 |
综合类 | 3篇 |
预防医学 | 85篇 |
眼科学 | 10篇 |
药学 | 72篇 |
肿瘤学 | 60篇 |
出版年
2021年 | 4篇 |
2020年 | 12篇 |
2019年 | 16篇 |
2018年 | 10篇 |
2017年 | 17篇 |
2016年 | 15篇 |
2015年 | 13篇 |
2014年 | 27篇 |
2013年 | 54篇 |
2012年 | 62篇 |
2011年 | 41篇 |
2010年 | 35篇 |
2009年 | 44篇 |
2008年 | 75篇 |
2007年 | 76篇 |
2006年 | 79篇 |
2005年 | 79篇 |
2004年 | 77篇 |
2003年 | 72篇 |
2002年 | 72篇 |
2001年 | 18篇 |
2000年 | 5篇 |
1999年 | 16篇 |
1998年 | 21篇 |
1997年 | 14篇 |
1996年 | 13篇 |
1995年 | 8篇 |
1994年 | 8篇 |
1993年 | 16篇 |
1992年 | 6篇 |
1991年 | 5篇 |
1990年 | 12篇 |
1989年 | 6篇 |
1988年 | 5篇 |
1987年 | 7篇 |
1986年 | 5篇 |
1985年 | 9篇 |
1984年 | 10篇 |
1983年 | 8篇 |
1982年 | 8篇 |
1981年 | 12篇 |
1980年 | 4篇 |
1979年 | 8篇 |
1978年 | 8篇 |
1976年 | 7篇 |
1973年 | 4篇 |
1972年 | 3篇 |
1971年 | 4篇 |
1967年 | 3篇 |
1965年 | 3篇 |
排序方式: 共有1158条查询结果,搜索用时 15 毫秒
991.
Few studies have investigated the relationship of temperament and character, as conceptualized in the Temperament and Character Inventory-Revised (TCI-R), to symptoms of depression and anxiety in the general population. In this study a random sample of subjects (20 to 70 years), in two Finnish cities, were surveyed with the TCI-R, Beck Depression and Anxiety Inventories, plus questions related to diagnosed lifetime mental disorders, health care use for psychiatric reasons during the past 12 months, and history of mental disorders in first-degree relatives. Altogether 347 subjects (38.6%) responded. Of the TCI-R dimensions, Harm Avoidance correlated with symptoms of depression (r(s)=0.555, p<0.001), anxiety (r(s)=0.560, p<0.001), self-reported lifetime mental disorder (r(s)=0.272, p<0.001), health care use for psychiatric reason during the past 12 months (r(s)=0.241, p<0.001) and family history of mental disorder (r(s)=0.202, p<0.001). Self-directedness correlated negatively with symptoms of depression (r(s)=-0.495, p<0.001), anxiety (r(s)=-0.458, p<0.001), lifetime mental disorder (r(s)=0.225, p<0.001) and health care use (r(s)=-0.135, p=0.013). Overall, Harm Avoidance and Self-directedness seem to associate moderately with depressive and anxiety symptoms, and somewhat predict self-reported use of health services for psychiatric reasons, and lifetime mental disorder. High harm avoidance may associate with a family history of mental disorder. 相似文献
992.
993.
Antti Alho Erkki O. Karaharju Olli Korkala Erkki M. Laasonen Teddy Holmstr m Carl Mü ller 《Acta orthopaedica》1989,60(2):143-153
We treated 21 aggressive and malignant bone tumors by wide resection and replacement with deep-frozen osteoarticular and segmental (intercalary and block) allografts. Radiologic and histologic studies showed a gradual accretion of new bone on the graft trabeculae, sometimes with total creeping substitution. Substantial resorption of grafted condylar bone occurred in 3 of 14 cases. One of them ended with arthrodesis; in the other 2 the result after augmentation autografts was fair. Radiographically, a gradual joint surface destruction was observed in all the osteoarticular grafts after 5 years, not correlating with joint function, however. Biopsies showed some cartilage regeneration. Each patient underwent, on an average, two operations. Function after osteoarticular grafts at 3-16 years was excellent in 1 case, good in 4, fair in 6, and poor in 1 case; 2 cases were too recent for evaluation. Function 3-12 years after segmental grafts was excellent in 3 cases and poor in 3 cases (1 amputation due to nonunion, 1 amputation due to recurrence, and 1 prosthetic replacement due to recurrence); 1 case was too recent for evaluation. We conclude that an allograft is an acceptable alternative in the reconstruction of large tumor defects. However, it still presents unsolved immunologic and preservation problems, which make the prognosis guarded. 相似文献
994.
995.
Markku Mesilaakso Maija Moilanen Prof. Erkki Rahkamaa 《Archives of environmental contamination and toxicology》1989,18(3):365-373
1H and13C NMR chemical shifts were determined from the NMR spectra of low concentration solutions of T-2 toxin, T-2 triol, HT-2 toxin, diacetoxyscirpenol, and neosolaniol. Isomerization of neosolaniol was observed to occur in chloroform solution. 1D and 2D1H and13C NMR techniques were used in order to determine the structure of the isomerization product, finally identified as 4,8-diacetoxy-3, 15-dihydroxy-12,13-epoxytrichothec-9-ene. 相似文献
996.
The chemical shifts and most of the main coupling constants of seven sarpagine alkaloids 1- 7 have been determined in a 400 MHz (1)H-NMR study. 相似文献
997.
Food antigens and enteroviruses are possible triggers of type 1 diabetes. Because permeability of the intestinal epithelium may facilitate contact of these antigens with the mucosal immune system, we set out to study intestinal permeability in patients with type 1 diabetes. Children with type 1 diabetes (n = 26, mean age 12 years, mean duration of disease 4 years) and 24 healthy age-matched control children were given mannitol and lactulose orally, and their intestinal permeability was measured as a percentage of this dose recovered in urine. Patients with type 1 diabetes did not differ in their permeability to lactulose, nor was their lactulose/mannitol ratio any different from that of controls. However, patients with type 1 diabetes who had the HLA-DQB 1*02 allele and, therefore, a higher risk for celiac disease (CD) absorbed significantly more mannitol (mean + 95% CI): 17.7% (15.2-20.2) than did those negative for this allele: 12.3% (8.2-16.4), p = 0.04. Their lactulose permeability was also higher: 0.30 (0.16-0.44) and 0.09% (0-0.18), respectively, p = 0.02. Although the differences in permeability reach statistical significance, there was still much overlap between the two groups in terms of actual laboratory values. The higher permeability of patients with the HLA-DQB1*02 allele suggests that these patients may be more prone to develop abnormal immune responses to food antigens. 相似文献
998.
Porphyromonas uenonis sp. nov., a pathogen for humans distinct from P. asaccharolytica and P. endodontalis 下载免费PDF全文
Finegold SM Vaisanen ML Rautio M Eerola E Summanen P Molitoris D Song Y Liu C Jousimies-Somer H 《Journal of clinical microbiology》2004,42(11):5298-5301
Three Porphyromonas species (Porphyromonas asaccharolytica, P. endodontalis, and the novel species that is the subject of the present report, P. uenonis) are very much alike in terms of biochemical characteristics, such as enzyme profiles and cellular fatty acid contents. P. asaccharolytica is distinguished from the other two species by virtue of production of alpha-fucosidase and glyoxylic acid positivity. The novel species is difficult to differentiate from P. endodontalis phenotypically and was designated a P. endodontalis-like organism for some time. However, P. endodontalis is recovered almost exclusively from oral sources and also grows poorly on Biolog Universal Agar, both characteristics that are in contrast to those of the other two organisms. Furthermore, P. uenonis is glycerol positive in the Biolog AN Microplate system. Both P. asaccharolytica and P. uenonis are positive by 13 other tests in the Biolog system, whereas P. endodontalis is negative by all of these tests. P. asaccharolytica grew well in both solid and liquid media without supplementation with 5% horse serum, whereas the other two species grew poorly without supplementation. Sequencing of 16S rRNA revealed about 10% divergence between the novel species and P. endodontalis but less than 2% sequence difference between the novel species and P. asaccharolytica. Subsequent DNA-DNA hybridization studies documented that the novel organism was indeed distinct from P. asaccharolytica. We propose the name Porphyromonas uenonis for the novel species. We have recovered P. uenonis from four clinical infections in adults, all likely of intestinal origin, and from the feces of six children. 相似文献
999.
E Tolvanen Y T Konttinen K Visa-Tolvanen T Reunala S Reitamo K K?h?nen 《Clinical immunology and immunopathology》1984,30(1):134-141
Monoclonal antibodies were used in conjunction with the biotin-avidin immunolectin method and the indirect immunofluorescence method to detect lymphocyte subsets in patients with dermatitis herpetiformis (DH) in 50% potassium iodide (KI)-induced skin lesions and in density-gradient-isolated peripheral blood. The proportions of T3-, T4-, and T8-positive lymphocytes in peripheral blood in patients with DH were 76 +/- 6, 48 +/- 7, and 28 +/- 4% and did not differ significantly from those in healthy controls. Among the inflammatory cells in situ in the reticular dermis, 82 +/- 5% were T3-positive lymphocytes, indicating a T-lymphocyte dominance in mature KI-induced DH lesions. The difference in the proportion of T4-positive lymphocytes in mature DH skin lesions and in patient blood was significant (63 +/- 9 and 48 +/- 7%, respectively (P less than 0.001), indicating that the composition of the dermal infiltrate does not reflect nonselective entrapment of blood mononuclear cells in situ. Studies of the kinetics of the local inflammatory response disclosed that at the preblister stage endogenous peroxidase-positive cells and granular, extracellular peroxidase were observed in the dermal papillae only 6 hr after induction, suggesting locally released proteinases as possible complement-degrading factors. Second, at the same time 63 +/- 15% of the inflammatory round cells in the dermis were Ia-positive, endogenous peroxidase-negative, T3- and T6-negative cells, indicating a pathomorphogenetic role for an early event no longer observable in the mature DH skin lesion. 相似文献
1000.
Optical tomography is an emerging method for non-invasive imaging of human tissues using near-infrared light. Generally, the tissue is assumed isotropic, but this may not always be true. In this paper, we present a method for the estimation of optical absorption coefficient allowing the background to be anisotropic. To solve the forward problem, we model the light propagation in tissue using an anisotropic diffusion equation. The inverse problem consists of the estimation of the absorption coefficient based on boundary measurements. Generally, the background anisotropy cannot be assumed to be known. We treat the uncertainties in the background anisotropy parameter values as modelling error, and include this in our model and reconstruction. We present numerical examples based on simulated data. For reference, examples using an isotropic inversion scheme are also included. The estimates are qualitatively different for the two methods. 相似文献