全文获取类型
收费全文 | 1835篇 |
免费 | 115篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 58篇 |
儿科学 | 98篇 |
妇产科学 | 24篇 |
基础医学 | 307篇 |
口腔科学 | 105篇 |
临床医学 | 146篇 |
内科学 | 336篇 |
皮肤病学 | 32篇 |
神经病学 | 92篇 |
特种医学 | 68篇 |
外科学 | 249篇 |
综合类 | 8篇 |
预防医学 | 223篇 |
眼科学 | 37篇 |
药学 | 89篇 |
中国医学 | 1篇 |
肿瘤学 | 83篇 |
出版年
2023年 | 5篇 |
2022年 | 12篇 |
2021年 | 27篇 |
2020年 | 15篇 |
2019年 | 21篇 |
2018年 | 35篇 |
2017年 | 30篇 |
2016年 | 27篇 |
2015年 | 26篇 |
2014年 | 30篇 |
2013年 | 63篇 |
2012年 | 84篇 |
2011年 | 93篇 |
2010年 | 49篇 |
2009年 | 50篇 |
2008年 | 103篇 |
2007年 | 111篇 |
2006年 | 94篇 |
2005年 | 83篇 |
2004年 | 87篇 |
2003年 | 93篇 |
2002年 | 92篇 |
2001年 | 56篇 |
2000年 | 36篇 |
1999年 | 47篇 |
1998年 | 31篇 |
1997年 | 27篇 |
1996年 | 23篇 |
1995年 | 18篇 |
1994年 | 24篇 |
1993年 | 17篇 |
1992年 | 40篇 |
1991年 | 37篇 |
1990年 | 30篇 |
1989年 | 38篇 |
1988年 | 26篇 |
1987年 | 21篇 |
1986年 | 27篇 |
1985年 | 36篇 |
1984年 | 36篇 |
1983年 | 32篇 |
1982年 | 22篇 |
1981年 | 12篇 |
1980年 | 7篇 |
1979年 | 15篇 |
1978年 | 9篇 |
1977年 | 9篇 |
1976年 | 8篇 |
1974年 | 6篇 |
1972年 | 6篇 |
排序方式: 共有1956条查询结果,搜索用时 15 毫秒
1.
2.
Erja Wiili-Peltola Mika Kivim?ki Marko Elovainio Marianna Virtanen 《Journal of health organization and management》2007,21(2-3):320-332
PURPOSE: The purpose to clarify what kind of managerial challenges employees experience regarding organisational justice in hospitals. DESIGN/METHODOLOGY/APPROACH: This exploratory study of 8,971 employees working in 14 hospitals and examines the concept of organisational justice in management with qualitative and quantitative methods. FINDINGS: An inductive content analysis of the comments revealed five integrative frames describing challenges in hospital management at respondents' workplaces. These frames should be regarded as major managerial challenges in hospitals. These findings illustrate important antecedents of organisational justice and suggest that work units tend to share the same perceptions of justice. They also reveal that individually produced comments reflect collective experiences in organisational justice. Further, the results indicate that problems in management and policies are often experienced in a complex way, and people making justice judgements do not separate procedural and interactional factors. RESEARCH LIMITATIONS/IMPLICATIONS: Although the commentators producing qualitative data represented many organisational hierarchy levels, the results should not be generalised to apply to horizontal, informal social relationships. PRACTICAL IMPLICATIONS: This paper gives useful information regarding challenges in human resources management in hospitals. ORIGINALITY/VALUE: The paper suggests that people making fairness judgements do not make a distinction between procedural and interpersonal factors. Instead, they use any information available to judge the righteousness of the management events. This paper serves to guide hospital managers towards a better understanding of the importance of organisational justice and its collective nature. 相似文献
3.
The purpose of this study was to correlate histologic findings in temporomandibular joint (TMJ) condyles and discs with their macroscopic appearance at surgery. The 24 patients with internal derangement of the joint included 20 women and 4 men (mean age, 37 years; range, 18 to 61 years). The tissue lesions varied in degree from mild soft-tissue fraying and bone remodeling to extensive resorption and new cartilage and bone formation with high phosphatase enzyme activities, and even to loss of articular soft tissue and breakdown of cortical bone. Reactions may arise in the hard tissues before they occur in the articular surface layers. 相似文献
4.
Urpo Nieminen M.D. Tarmo Koivisto M.D. Arvi Kahri M.D. Martti Färkkilä M.D. 《The American journal of gastroenterology》1997,92(1):139-142
We report a patient with Sjögren's syndrome and multiple gastrointestinal manifestations who successfully responded to therapy with ursodeoxycholic acid. Our patient had sialoadenitis with dry mouth, dry eyes, arthralgia, chronic pancreatitis, sclerosing cholangitis, and pulmonary inflitrations. The first signs of disease were the symptoms of chronic pancreatitis followed by icterus, caused by extrahepatic bile duct obstruction. Sclerosing cholangitis was diagnosed by liver biopsy and endoscopic retrograde cholangiography. Sialoadenitis, causing dry mouth, was verified by buccal biopsy. Pulmonary infiltrations were seen on standard chest x-ray, and also shown by high-resolution computed tomography examination. Obstructive icterus and even pulmonary infiltration responded successfully to treatment with ursodeoxycholic acid. 相似文献
5.
A new monoclonal antibody against the GABA-protein conjugate shows immunoreactivity in sensory neurons of the rat. 总被引:5,自引:0,他引:5
A monoclonal antibody, 115AD5, was raised against GABA coupled to bovine serum albumin. The monoclonal antibody 115AD5 also reacted with other GABA-protein conjugates. The specificity of the monoclonal antibody was corroborated by enzyme-linked immunoassay, dot-immunobinding experiments and immunostaining of rat cerebellum sections. The monoclonal antibody 115AD5 could successfully be applied on Vibratome and cryostat sections using either indirect immunofluorescence or peroxidase techniques. In rat cerebellar cortex the monoclonal antibody 115AD5 gave an intense immunoreaction in stellate cells, in Golgi neurons, and in basket cells and their processes around Purkinje cell bodies. Purkinje cell dendrites showed GABA immunoreactivity while the cell bodies were non-reactive or only weakly reactive. There was labelling in some nuclei of Purkinje cells. GABA immunoreactivity was also found in dot-like structures in the granular layer. A large population of sensory neurons in rat thoracic and lumbar spinal dorsal root ganglia presented an intense immunoreactivity for the monoclonal antibody 115AD5. Nerve bundles immunoreactive for GABA were also seen in these ganglia. In the trigeminal ganglion, a major population of sensory neurons and some of their processes presented immunoreactivity for GABA. In the sensory nodose ganglion of the vagus nerve, many neuronal cell bodies and some fibres were immunoreactive for GABA. Ligation of the vagus nerve caudal to the ganglion resulted in an increased GABA immunoreactivity in neuronal somata of the ganglion, as well as in nerve fibres on the ganglionic side of the ligature. The present results suggest that in the rat, a population of sensory neurons in thoracic and lumbar spinal dorsal root ganglia, as well as in the trigeminal and nodose ganglia contain GABA. The presence of GABA immunoreactivity in these neurons raises the possibility of a neurotransmitter or modulator role. 相似文献
6.
Markku Walamies Vesa Virtanen Matti Koskinen Arto Uusitalo 《European journal of nuclear medicine and molecular imaging》1994,21(9):968-972
The decrease in mortality among patients receiving thrombolytic therapy for myocardial infarction is greater than would be expected from the improvement in left ventricular contractile function alone; thus some additional advantage of recanalization of the infarctrelated coronary artery probably exists. Changes in the post-infarction myocardial metabolic state with respect to artery patency have not been studied with a gamma camera previously. A single-photon emission tomography scan using the fatty acid analogue para-123I-iodophenylpentadecanoic acid was performed at rest before hospital discharge on nine patients with first anterior myocardial infarction. All patients had received intravenous thrombolytic therapy at the beginning of the insult. The semiquantitative analysis of the left ventricle included a total of 44 segments in each patient. The test was repeated 3 months later, with the patients divided into two groups: six patients had an angiographically patent left anterior descending coronary artery (group A), and three an occluded artery (group B). In group A the number of myocardial segments with abnormal (<70% of maximum) fatty acid uptake was initially 20.2±4.7 (mean±SD) and was reduced to 11.3±6.1 during the follow-up (95% confidence interval of the decrease 16.0–1.7 segments). In group B the number of these aberrant segments was fairly constant (21.7±13.1, initial test, and 21.3±13.3, retest). Our preliminary results suggest that even when thrombolytic therapy fails to prevent myocardial infarction, myocardial fatty acid metabolism has a better change of recovering if the relevant coronary artery has regained its patency. This finding emphasizes the need for further study to establish whether a direct link exists between myocardial metabolic state and patient survival after infarction. 相似文献
7.
Dietary fibre and fibre fractions in the diet of Finnish diabetic and non-diabetic adolescents 总被引:1,自引:0,他引:1
The intakes of total dietary fibre, water-soluble noncellulosic polysaccharides (WSNCP), water-insoluble noncellulosic polysaccharides (WISNCP), cellulose and lignins of 152 diabetic and 74 non-diabetic adolescents were studied. Food consumption data had been collected by means of two 48 h recall interviews. The diabetics obtained more total dietary fibre (33 g vs 18 g) and all fibre fractions than the controls. The fibre density of the diet was higher for the diabetics than for the controls for all meals and snacks. Positive correlations were found between total dietary fibre intake per 1000 kcal and energy-adjusted intakes of total carbohydrate, starch and most vitamins and minerals both in the diabetics and controls. A high concentration of dietary fibre in the diet thus indicated a higher general nutrient density. 相似文献
8.
Thomas Zeiler MD Antti Taivainen MD PhD Marja Rytkönen PhD Jaakko Rautiainen MSc Henry Karjalainen PhD Rauno Mäntjärvi MD PhD Leena Tuomisto MD PhD Tuomas Virtanen MD PhD 《The Journal of allergy and clinical immunology》1997,100(6):721-727
Background: Lately, renewed interest has arisen in the new forms of allergen immunotherapy because they may offer alternatives for drug treatment. Objective: The purpose of this study was to develop a well-characterized preparation of the main respiratory cow dander allergen, Bos d 2, with attenuated allergenic activity. Methods: The immunologic characteristics of Bos d 2 preparations were studied by indirect IgE ELISA, ELISA inhibition, Western blotting, histamine release, skin prick tests, and the proliferation tests of allergen-specific T-cell clones. Results: The complete recombinant Bos d 2 was observed to bind effectively, IgE of cow-allergic patients in indirect ELISA. In other experiments, the IgE-binding capacity of recombinant Bos d 2 proved to be lower compared with native Bos d 2. When the two overlapping recombinant fragments of Bos d 2 (corresponding amino acids 1-131 and 81-172, respectively) covering the whole molecule were compared with the complete recombinant Bos d 2 with several methods, only a low level of residual reactivity was observed. For example, recombinant fragments could not bind antibody at all in ELISA inhibition tests retaining, however, some reactivity in skin prick tests. In contrast, the fragments were able to stimulate vigorously Bos d 2-specific T-cell clones. Conclusion: The approach we have taken may offer a simple and reproducible way to produce hypoallergenic preparations for immunotherapy, circumventing simultaneously some of the problems of other experimental methods such as individual T-cell epitope recognition in peptide-based immunotherapy. (J Allergy Clin Immunol 1997;100:721-7.) 相似文献
9.
alpha 2-Adrenoceptor agonists decrease free 3-methoxy-4-hydroxyphenylglycol in rat cerebrospinal fluid 总被引:2,自引:0,他引:2
The effects of alpha 2-adrenoceptor agonists on the concentrations of monoamine metabolites in cisternal cerebrospinal fluid (CSF) of freely moving rats were determined. Clonidine and two new imidazole derivatives, detomidine and medetomidine, and diazepam (as a control substance) were administered in sedative doses and the concentrations of unconjugated 3-methoxy-4-hydroxyphenylglycol (MHPG), 5-hydroxyindoleacetic acid (5-HIAA) and homovanillic acid (HVA) in CSF were monitored for 48 h. The alpha 2-agonists caused a dose-dependent, statistically significant decrease in the concentration of MHPG in CSF compared to the concentration in animals treated with saline or diazepam. Detomidine caused a statistically significant increase in the concentration of 5-HIAA compared to control treatments. The present results demonstrate the usefulness of monitoring drug-induced alterations in central nervous system (CNS) noradrenergic activity by measuring free MHPG in repeatedly collected cisternal CSF samples from freely moving rats. The alpha 2-agonists reduced the concentration of MHPG in CSF, indicating a decreased release, metabolism and turnover of noradrenaline in the CNS. 相似文献
10.
Complete Sequence of a 93.4-kb Contig from Chromosome 3 of Trypanosoma cruzi Containing a Strand-Switch Region 下载免费PDF全文
Bjrn Andersson Lena slund Martti Tammi Anh-Nhi Tran Jrg D. Hoheisel Ulf Pettersson 《Genome research》1998,8(8):809-816
We have initiated large-scale sequencing of the third smallest chromosome of the CL Brener strain of Trypanosoma cruzi and we report here the complete sequence of a contig consisting of three cosmids. This contig covers 93.4 kb and has been found to contain 20–30 novel genes and several repeat elements, including a novel chromosome 3-specific 400-bp repeat sequence. The intergenic sequences were found to be rich in di- and trinucleotide repeats of varying lengths and also contained several known T. cruzi repeat elements. The sequence contains 29 open reading frames (ORFs) longer than 700 bp, the longest being 5157 bp, and a large number of shorter ORFs. Of the long ORFs, seven show homology to known genes in parasites and other organisms, whereas four ORFs were confirmed by sequencing of cDNA clones. Two shorter ORFs were confirmed by a database homology and a cDNA clone, respectively, and one RNA gene was identified. The identified genes include two copies of the gene for alanine-aminotransferase as well as genes for glucose-6-phosphate isomerase, protein kinases and phosphatases, and an ATP synthase subunit. An interesting feature of the sequence was that the genes appear to be organized in two long clusters containing multiple genes on the same strand. The two clusters are transcribed in opposite directions and they are separated by an ~20-kb long, relatively GC-rich sequence, that contains two large repetitive elements as well as a pseudogene for cruzipain and a gene for U2snRNA. It is likely that this strand switch region contains one or more regulatory and promoter regions. The reported sequence provides the first insight into the genome organization of T. cruzi and shows the potential of this approach for rapid identification of novel genes. 相似文献