全文获取类型
收费全文 | 422篇 |
免费 | 22篇 |
专业分类
耳鼻咽喉 | 5篇 |
儿科学 | 2篇 |
妇产科学 | 9篇 |
基础医学 | 41篇 |
口腔科学 | 3篇 |
临床医学 | 54篇 |
内科学 | 75篇 |
皮肤病学 | 2篇 |
神经病学 | 67篇 |
特种医学 | 31篇 |
外科学 | 47篇 |
综合类 | 3篇 |
预防医学 | 62篇 |
眼科学 | 3篇 |
药学 | 26篇 |
肿瘤学 | 14篇 |
出版年
2023年 | 6篇 |
2022年 | 11篇 |
2021年 | 8篇 |
2020年 | 12篇 |
2019年 | 17篇 |
2018年 | 14篇 |
2017年 | 14篇 |
2016年 | 17篇 |
2015年 | 8篇 |
2014年 | 12篇 |
2013年 | 28篇 |
2012年 | 31篇 |
2011年 | 23篇 |
2010年 | 24篇 |
2009年 | 18篇 |
2008年 | 26篇 |
2007年 | 31篇 |
2006年 | 30篇 |
2005年 | 25篇 |
2004年 | 25篇 |
2003年 | 22篇 |
2002年 | 16篇 |
2001年 | 3篇 |
2000年 | 2篇 |
1999年 | 5篇 |
1997年 | 2篇 |
1996年 | 4篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1991年 | 3篇 |
1990年 | 1篇 |
排序方式: 共有444条查询结果,搜索用时 15 毫秒
431.
Sanna-Mari Kynkäänniemi Maria Kettu Raine Kortet Laura Härkönen Arja Kaitala Tommi Paakkonen Anne-Mari Mustonen Petteri Nieminen Sauli Härkönen Hannu Ylönen Sauli Laaksonen 《Parasitology research》2014,113(4):1489-1497
Blood-sucking ectoparasites have often a strong impact on the behaviour of their hosts. The annual insect harassment of reindeer (Rangifer tarandus tarandus) has increased in the southern part of the Finnish reindeer herding area because of the recent invasion of a blood-feeding ectoparasitic louse-fly, the deer ked (Lipoptena cervi). We studied the impact of the deer ked on the behaviour of reindeer. Twelve reindeer were infested with a total of 300 keds/reindeer on six occasions in a 5-week period during the deer ked flight season in autumn, while six non-infested reindeer were used as controls. Behavioural patterns indicating potential stress were monitored by visual observation from August to December. The infested reindeer displayed more incidences of restless behaviour than the controls. Shaking and scratching were the most common forms of restless behaviour after infestation of deer keds. Increased grooming was also observed after the transplantation and also later, 1 month after the infestation. Based on the results, the deer ked infestation can cause acute behavioural disturbance in reindeer and, thus, could pose a potential threat to reindeer welfare. Antiparasitic treatment with, e.g. ivermectin, may increase the welfare of parasitized reindeer by reducing deer keds. If the deer ked infestation intensity on the reindeer herding area increases and restless behaviour of reindeer becomes more common, the present results can help in further evaluation of the duration and magnitude of behavioural changes. 相似文献
432.
Randall McClelland Eliane Wauthier Tommi Tallheden Lola M. Reid 《Molecular imaging and biology》2011,13(5):911-922
Purpose
The purpose is to address the problem in magnetic resonance imaging (MRI) of contrast agent dilution. 相似文献433.
Soili M. Lehto Anne Huotari Leo Niskanen Karl-Heinz Herzig Tommi Tolmunen Heimo Viinamäki Heli Koivumaa-Honkanen Kirsi Honkalampi Sanna Sinikallio Heli Ruotsalainen Jukka Hintikka 《Progress in neuro-psychopharmacology & biological psychiatry》2010
Major depressive disorder (MDD) has been associated with dysregulated immune systems and impaired T cell function, but data on depression-related alterations in the levels of immunomodulatory growth factors are scarce. In order to further clarify the mechanisms underlying immune system dysregulation in depressed subjects, we examined the associations between MDD and serum levels of two immunomodulatory growth factors, interleukin (IL)-7 and granulocyte-colony stimulating factor (G-CSF), in 122 subjects (MDD with long-term symptomatology, n = 61; controls, n = 61). The MDD subjects had lowered levels of IL-7. In a model adjusted for age, gender and body mass index, subjects in the lowest tertile of IL-7 had a 3.4-fold increased likelihood for MDD (p = 0.010). Further adjustments for sleep disturbances, alcohol use, smoking, and metabolic syndrome did not alter these findings. Moreover, the exclusion of subjects with rheumatoid arthritis, coronary heart disease, or the use of non-steroidal anti-inflammatory medications or oral corticosteroids only slightly attenuated the findings. The G-CSF levels did not differ between the two groups. The lowering of the serum levels of IL-7, a regulator of T cell homeostasis, in MDD subjects may underlie the depression-related impaired T cell function. 相似文献
434.
435.
Paakkonen T Mustonen AM Käkelä R Laaksonen S Solismaa M Aho J Puukka K Nieminen P 《Parasitology research》2012,111(3):1223-1232
The deer ked (Lipoptena cervi, Diptera, Hippoboscidae) is a haematophagous parasitic fly of the moose (Alces alces) and other cervids, and it is very common in southern and central parts of Finland. The aim of this study was to determine how the intensive parasitism caused by the deer ked affects the health and welfare of the moose. Moose blood samples (n?=?78) were collected from deer ked-infested and ked-free regions at 62-68° N and analysed for haematology and clinical chemistry. In addition, tissue samples of moose (n?=?23) were collected from a deer ked-infested region at 62° N to determine how the parasite load correlates to several physiological variables of the host. The differences in the blood and plasma values between the deer ked-free and ked-infested animals were minor. In the infested regions, the moose had higher mean corpuscular haemoglobin concentrations unlikely to have been caused by the parasitism. The intensities of deer keds had no consistent correlations with the values of plasma clinical chemistry, endocrinology, amino acids, tissue enzyme activities or body energy stores. However, the hepatic percentages of several individual n-3 polyunsaturated fatty acids (PUFA) and the n-3 PUFA sum correlated inversely with the intensity and density of deer keds. Although a wide array of physiological variables was determined, only minor effects caused by the heavy deer ked parasitism could be detected, suggesting that the moose might tolerate this parasite relatively well. 相似文献
436.
437.
Kuorilehto T Kinnunen P Nissinen M Alanne M Leskelä HV Lehenkari P Peltonen J 《Pathology, research and practice》2006,202(9):687-690
Neurofibromatosis type 1 (NF1) is a common dominantly inherited disease. More than half of NF1 patients suffer from skeletal manifestations, of which congenital pseudarthrosis of tibia (CPT) is one of the most incapacitating lesions. Two NF1 patients with CPT were operated, and the resected tissues were analyzed using immunohistochemistry and/or in situ hybridization for NF1 protein and mRNA, p-p44/42 MAPK, and S100 protein. Both patients displayed thick-walled arteries and veins with a small lumen within the fibrotic tissue in the vicinity of pseudarthrosis. Endothelial cells were highly positive for p-p44/42 MAPK. A subpopulation of cells surrounding the blood vessels was S100 protein-positive. However, the exact identity of the S100-positive cells remains to be elucidated. Neurofibromin mRNA and protein labeling was detected in both cell types. In conclusion, decreased NF1 function as a RAS-GAP in the endothelium may contribute to vascular thickening in CPT. 相似文献
438.
439.
Lamberg T Remes V Helenius I Schlenzka D Seitsalo S Poussa M 《The Journal of bone and joint surgery. American volume》2007,89(3):512-518
BACKGROUND: Intermediate-term radiographic studies have shown that anterior and circumferential techniques result in high fusion rates in patients with high-grade spondylolisthesis, whereas posterolateral fusion is less successful. We are not aware of any long-term comparative studies in which these three methods have been evaluated with regard to functional outcome, including systematic spinal mobility and trunk strength measurements. METHODS: Sixty-nine of eighty-three consecutive patients with high-grade isthmic spondylolisthesis who underwent posterolateral (twenty-one), anterior (twenty-three), or circumferential (twenty-five) uninstrumented spondylodesis between 1977 and 1991 participated in the study. The average duration of follow-up was 17.2 years. Radiographs that were made preoperatively and at the time of the most recent follow-up were assessed with regard to fusion quality and degenerative changes. Outcome was assessed at the time of the most recent follow-up by independent observers on the basis of a physical examination, spinal mobility and nondynamometric trunk strength measurements, and Oswestry Disability Index scores. RESULTS: The mean preoperative vertebral slip was 61% in the posterolateral fusion group, 63% in the anterior fusion group, and 71% in the circumferential fusion group. The final fusion rate was 86% (eighteen of twenty-one) in the posterolateral fusion group, 100% (twenty-three of twenty-three) in the anterior fusion group, and 96% (twenty-four of twenty-five) in the circumferential fusion group. A decrease in lumbar intervertebral disc height at the first mobile level superior to the fusion was noted in five patients in the posterolateral fusion group, seven patients in the anterior fusion group, and one patient in the circumferential fusion group (p = 0.037). The mean Oswestry Disability Index score was 9.7 for the posterolateral fusion group, 8.9 for the anterior fusion group, and 3.0 for the circumferential fusion group (p = 0.035). Nondynamometric trunk strength measurements corresponded with referential values. Abnormally low lumbar flexion affected the posterolateral and circumferential fusion groups more often than the anterior fusion group (p = 0.0015). The percentage of slip showed inverse correlations with lumbar flexion, lumbar extension, and trunk side-bending. CONCLUSIONS: As assessed on the basis of patient-based outcomes, circumferential in situ fusion provided slightly better long-term results than did posterolateral or anterior in situ fusion. When the radiographic and functional results were combined with the patient-based outcomes, the overall differences between the three groups were small. 相似文献
440.