全文获取类型
收费全文 | 531篇 |
免费 | 36篇 |
专业分类
耳鼻咽喉 | 8篇 |
儿科学 | 29篇 |
妇产科学 | 13篇 |
基础医学 | 98篇 |
口腔科学 | 14篇 |
临床医学 | 50篇 |
内科学 | 79篇 |
皮肤病学 | 3篇 |
神经病学 | 25篇 |
特种医学 | 7篇 |
外科学 | 126篇 |
综合类 | 1篇 |
一般理论 | 2篇 |
预防医学 | 77篇 |
眼科学 | 1篇 |
药学 | 28篇 |
肿瘤学 | 6篇 |
出版年
2022年 | 3篇 |
2021年 | 12篇 |
2020年 | 7篇 |
2019年 | 11篇 |
2018年 | 9篇 |
2017年 | 7篇 |
2016年 | 7篇 |
2015年 | 11篇 |
2014年 | 13篇 |
2013年 | 23篇 |
2012年 | 32篇 |
2011年 | 23篇 |
2010年 | 16篇 |
2009年 | 11篇 |
2008年 | 24篇 |
2007年 | 32篇 |
2006年 | 32篇 |
2005年 | 23篇 |
2004年 | 16篇 |
2003年 | 27篇 |
2002年 | 21篇 |
2001年 | 11篇 |
2000年 | 13篇 |
1999年 | 12篇 |
1998年 | 7篇 |
1997年 | 10篇 |
1996年 | 5篇 |
1995年 | 5篇 |
1994年 | 9篇 |
1993年 | 6篇 |
1992年 | 12篇 |
1991年 | 9篇 |
1990年 | 14篇 |
1989年 | 5篇 |
1988年 | 10篇 |
1987年 | 8篇 |
1986年 | 11篇 |
1985年 | 16篇 |
1984年 | 6篇 |
1983年 | 5篇 |
1981年 | 3篇 |
1980年 | 2篇 |
1979年 | 4篇 |
1978年 | 5篇 |
1974年 | 3篇 |
1973年 | 2篇 |
1971年 | 5篇 |
1968年 | 1篇 |
1966年 | 1篇 |
1955年 | 1篇 |
排序方式: 共有567条查询结果,搜索用时 10 毫秒
1.
We have sought to define a way in which nitrous oxide can be safely and universally used at minimal to low flows by utilising a circle system with a controlled leak provided by a standard gas analyser sampling line and a fresh gas supply of 50% nitrous oxide in oxygen, entering from a trunk interposed between the ventilator and the circle system. Although preliminary calculations suggested that this arrangement was likely to work, it was found that 13 of 23 patients studied prospectively developed an inspired oxygen fraction below 0.3. We conclude that, although this arrangement provides a new means of introducing nitrous oxide into the circle breathing system, it does not appear inherently safer or more convenient than the conventional route. 相似文献
2.
3.
A M Travers C J Nel R Barry C W Pienaar B Filmater 《Suid-Afrikaanse tydskrif vir geneeskunde》1990,77(3):140-143
Atherosclerosis is a systemic disorder and significant lesions often occur in organ systems other than the symptomatic area. Three groups of patients, those admitted to hospital with either coronary artery disease, carotid artery stenosis or peripheral vascular disease, were examined for concomitant atherosclerotic lesions. Non-invasive tests, namely duplex scanning of the carotid arteries, arm ergometer exercise testing, and segmental pressure of the limbs, were used during evaluation. A clear association between ischaemic heart disease, carotid artery stenosis and femoropopliteal disease was found. Women appear to be more prone to multi-organ involvement than men; their higher average age on admission to hospital is a possible explanation for this in some cases, but not all. 相似文献
4.
People who are prone to motion sickness have a directional preponderance of nystagmus to the left. Centrifuging will change this preponderance to the right in most people, and at the same time reduce their tendency towards motion sickness but only with regard to air travel. 相似文献
5.
Myofibres in the normal left ventricle (LVs) of 24 healthy young accident victims and the diseased LVs of 10 subjects who died from constrictive pericarditis or congestive (African) cardiomyopathy were subjected to morphometric evaluation. Each myofibre was represented by a pair of measurements: cross-nuclear fibre (FD) and nuclear (ND) diameters. Using a VIDS image analyser interfaced with a light microscope, 150 paired measurements were determined for each of the 34 specimens. The bivariate relationship between FD and ND for each group of specimens were expressed as linear regressions. The limits for the group distribution of normal specimen FD/ND means were calculated and graphically depicted in the form of an ellipse. Disease specimens were plotted for comparison. Of the normal specimens, 23/24 FD/ND coordinates fell within the "normal' ellipse whereas the altered relationship between FD and ND in pathological myocardia caused all 10 specimen means to be plotted outside the ellipse and their regression lines to be displaced from normal. It is suggested that the normal data define the morphometric parameters of LV myofibres in healthy hearts and create a graphic standard by which myofibre pathology in hearts suspected of disease can be detected. 相似文献
6.
Nelson K. S. Khoo Francis P. H. Chan Mary Nel Saarloos Peeyush K. Lala 《Clinical & experimental metastasis》1992,10(4):239-252
In this study the efficacy of treatment of two cyclo-oxygenase inhibitors, ibuprofen (Ibu) and indomethacin (Indo), are compared in the immunotherapy of metastasis designed to reverse prostaglandin E2 (PGE2)mediated inactivation of interleukin-2 (IL-2)-dependent host killer cell lineages. These agents were tested either alone for the prevention of metastasis or in combination with IL-2 for the eradication of established metastasis. C3H/HeN mice were placed on chronic oral Ibu (CIbT; 200 and 600 ,g/ml of water) or Indo (CIT; 10 g/ml) 5 days after s.c. transplantation of 5 × 105 metastatic C3L5 mammary carcinoma for the prevention of spontaneous lung metastases. They showed intolerance to Indo at a dosage of 14 g/ml, which was well tolerated by other mouse strains in previous studies, but tolerated the Ibu dosages used. Control and treated mice were killed on day 30 to score metastatic lung colonies, to evaluate killer activity in splenocytes against natural killer (NK)-sensitive YAC-1 lymphoma or NK-resistant C3L5 adenocarcinoma and 8911 lymphoma targets, and to phenotype the surface markers of killer cells. CIbT and CIT alone at the above dosage significantly reduced the number of lung colonies, retarded local tumor growth and restored NK activity of splenic killer cells expressing AGM-1+, Thy-1–, Lyt-2– phenotype. To treat established lung metastasis, mice bearing 15-day C3L5 transplants were given CIbT or CIT alone or in combination with two 4-day rounds (days 20–23, 31–34) of IL-2 (15 000 Cetus units, i.p. every 8 h) and were killed on day 35 to score lung colonies and characterize splenic killer cells. CIbT or CIT alone reduced the number of spontaneous lung metastases and restored anti-YAC-1 killer function of splenocytes with NK-like phenotype (AGM-1+, Thy-1–, Lyt-2–); some anti-C3L5 killer function was also generated in the high dose Ibu group and the killer cell showed AGM-1+, Thy-1+ and Lyt-2+ phenotype. Combined therapies with CIbT or CIT plus IL-2 were more effective in reducing metastases and promoting killer cell function, the best results being achieved with high dose Ibu + IL-2. All killer cells expressed AGM-1 and Thy-1. In addition, C3L5 killer cells also expressed Lyt-2, suggesting T-cell stimulation. PGE2 synthesis in the host was inhibited by at least 50% in mice subjected to CIbT or CIT. Thus, Ibu proved to be an excellent substitute for Indo in preventing metastasis and NK cell activation when given alone, and also in ameliorating established metastasis and activating lymphokine-activated killer cells when combined with IL-2. 相似文献
7.
Localization of a novel X-linked congenital stationary night blindness locus: close linkage to the RP3 type retinitis pigmentosa gene region 总被引:1,自引:0,他引:1
Bergen Arthur A.B.; Brink Jacoline B.ten; Riemslag Frans; Schuurman Ellen J.M.; Tijmes Nel 《Human molecular genetics》1995,4(5):931-935
X-linked congenital stationary night blindness (CSNBX) is anon-progressive retinal disorder characterized by decreasedvisual acuity and loss of night vision. CSNBX Is clinicallyheterogeneous with respect to the involvement of retinal rodsand/or cones in the disease. in this study, we localize a newlocus for CSNBX to Xp21.1, thus providing evidence that CSNBXis also genetically heterogeneous. A clear correlation betweendifferent genotypes and phenotypes cannot be found yet. Thenew CSNBX gene described here is closely linked to the X-linkedretinitis pigmentosa type 3 gene region, which supports thehypothesis that there may be a functional relationship betweencongenital stationary night blindness and retinitis pigmentosa. 相似文献
8.
Kooiman CG van Rees Vellinga S Spinhoven P Draijer N Trijsburg RW Rooijmans HG 《Psychotherapy and psychosomatics》2004,73(2):107-116
BACKGROUND: Affect regulation is assumed to be a biologically based function that can become disrupted by inadequate parenting and by traumatic experiences. We studied the relation between the perceived parental parenting style, and sexual and physical abuse, with alexithymia, dissociation, anxiety and depression. METHODS: In a cross-sectional study psychiatric outpatients were administered a structured interview on childhood physical and sexual abuse and they completed a number of questionnaires about the parenting styles of their parents, and about alexithymia, dissociation and mood pathology. RESULTS: Maternal and paternal parenting styles were moderately correlated with alexithymia and depression. The paternal parenting style was also correlated with dissociation. Optimal parenting of one of the parents had a buffering effect on the degree of alexithymia, but not on the severity of other forms of affect dysregulation. The effect of sexual or physical abuse did not add to that of parental parenting style in terms of predicting affect dysregulation. However, a positively perceived maternal parenting style was found to have a buffering effect in terms of the degree of alexithymia, if sexual abuse had also taken place. CONCLUSIONS: Perceived parenting does appear to be of some significance in the development of alexithymia. Optimal parenting of one of the parents may protect against the development of alexithymia when the parenting of the other parent is perceived as non-optimal. However, it is likely that other factors besides parental care and sexual or physical abuse play an important role in the development of an adequate affect regulation. 相似文献
9.
A Locus for Autosomal Recessive Pseudoxanthoma Elasticum, with Penetrance of Vascular Symptoms in Carriers, Maps to Chromosome 16p13.1 下载免费PDF全文
Simone van Soest Jaap Swart Nel Tijmes Lodewijk A. Sandkuijl Jago Rommers Arthur A.B. Bergen 《Genome research》1997,7(8):830-834
Pseudoxanthoma elasticum (PXE) is a heritable systemic disorder characterized by calcification of the elastic fibers of the connective tissue. Symptoms are predominantly noted in the eye, the skin, and the cardiovascular system, resulting in visual loss, skin lesions, and life-threatening vascular disease. In this study we combined homozygosity mapping and genome scanning with 374 markers in affected individuals from a PXE family from a genetically isolated population in The Netherlands. Initial homozygosity in two or three patients was found with up to 20 markers, among which D16S292 located in 16p13.1. Upon refined and more extensive family screening of the latter region, close linkage without recombination was found with the marker D16S764 (Zmax=6.27). Despite clear autosomal recessive inheritance of the ocular symptoms in PXE, vascular symptoms appear in 40%–50% of the heterozygotes. 相似文献
10.
Summary The eight largest double-stranded (ds) RNA genome segments of Epizootic haemorrhagic disease virus (EHDV) serotype 2 (Alberta strain) have been cloned. Of these, segments 4, 5, 6, 7, and 8 are represented by clones that correspond in size to those predicted for full-length clones. The different clones were used as nucleic acid probes to study the nucleic acid homology of cognate genes of four different EHDV serotypes. The results indicated that the 4 isolates may be subdivided in two geographic groups which include Ibaraki virus as the sole member of one group and EHDV1 (New Jersey), EHDV2 (Alberta) and EHDV6 (XBM67—isolated in South Africa) as a second. Genome segments 1, 3, 4, 6, and 8 were found to be highly conserved with more than 90% homology amongst cognate genes of three of the members of the EHDV serogroup. Of these, segments 1 and 3 showed the largest degree of homology with cognate genes of members of the BTV serogroup. Segment 6 and 8 probes of EHDV2 (Alberta) on the other hand did not hybridize with BTV dsRNA under conditions of moderate to low stringency and are recommended for use as EHDV group-specific probes. 相似文献