全文获取类型
收费全文 | 1922篇 |
免费 | 42篇 |
国内免费 | 20篇 |
专业分类
耳鼻咽喉 | 93篇 |
儿科学 | 24篇 |
妇产科学 | 111篇 |
基础医学 | 192篇 |
口腔科学 | 13篇 |
临床医学 | 124篇 |
内科学 | 691篇 |
皮肤病学 | 7篇 |
神经病学 | 135篇 |
特种医学 | 50篇 |
外科学 | 185篇 |
综合类 | 12篇 |
预防医学 | 70篇 |
眼科学 | 53篇 |
药学 | 137篇 |
肿瘤学 | 87篇 |
出版年
2023年 | 10篇 |
2022年 | 101篇 |
2021年 | 140篇 |
2020年 | 29篇 |
2019年 | 47篇 |
2018年 | 68篇 |
2017年 | 29篇 |
2016年 | 36篇 |
2015年 | 36篇 |
2014年 | 78篇 |
2013年 | 85篇 |
2012年 | 137篇 |
2011年 | 160篇 |
2010年 | 93篇 |
2009年 | 44篇 |
2008年 | 116篇 |
2007年 | 151篇 |
2006年 | 135篇 |
2005年 | 145篇 |
2004年 | 110篇 |
2003年 | 122篇 |
2002年 | 87篇 |
2001年 | 2篇 |
2000年 | 5篇 |
1999年 | 2篇 |
1998年 | 4篇 |
1997年 | 3篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1990年 | 1篇 |
1988年 | 1篇 |
1987年 | 1篇 |
排序方式: 共有1984条查询结果,搜索用时 15 毫秒
1.
Dariusz Marczak Aleksandra Rapa?a Monika Bekiesińska-Figatowska 《Chirurgia narzadów ruchu i ortopedia polska》2006,71(6):473-475
Transient osteoporosis of the hip is an uncommon disorder of unclear etiology. It is often confused with other diagnosis including osteonecrosis of the femoral head. Authors describe a case of transient osteoporosis of the hip of 32 years woman. The symptoms occurred in third trimester of pregnancy. The primary symptoms were right hip pain and decreased range of motion of the right hip. In diagnostic process helpful were clinical examination, X-ray, ultrasonography, MRI and microscopic examination. As a treatment authors used walking on crutches, calcitonin and calcium preparate. After a few months remission of symptoms and normalization in accessory investigations were obtained. 相似文献
2.
Łaba A Ostrowska A Patrzałek D Paradowski L Lange A 《Archivum immunologiae et therapiae experimentalis》2005,53(5):442-453
INTRODUCTION: The successful use of hepatocytes depends on a reliable demonstration of the functional and morphological integrity of isolated cells. Herein we investigated whether the isolation and cryopreservation of primary human hepatocytes can compromise cell viability and liver-specific characteristics. MATERIAL/METHODS: Hepatocytes were isolated from encapsulated human liver segments by a modified 2-step perfusion technique. Isolated cells were Percoll-purified, cryopreserved, and stored in liquid nitrogen for 1-12 months. For rapid assessment of fresh and cryopreserve/thawed hepatocyte yield and viability, the cells were stained with trypan blue or labeled with fluorochromes. For immunocytochemical analysis, the cells were labeled with monoclonal antibodies for the presence of the following antigens and chemokines: CD3, CD45Ro, CD45Ra, CD34, CD68, CD90, CD95, CD20, HLA-DR, Ki67, PCNA, Bcl-2, p53, CXCR3, CXCR4, and SDF-1. The cells were tested for several specific functions, such as ureagenesis, energy status, MTT activity, lactate dehydrogenase leakage, and total CYP450 content. RESULTS: Assessment of both freshly isolated (Percoll-purified) and cryopreserved/thawed hepatocytes revealed a low constitutive level of contamination by non-parenchymal cells compared with crude (unpurified) preparations and tissue sections. All viable hepatocytes showed intact morphology and retained CYP450 protein, energy status, and urea synthesis. CONCLUSIONS: Modifications in hepatocyte preparations, such as depletion of dead, damaged, and nonparenchymal cells, improves cell purity, which can be adapted to further evaluation of hepatocyte immunogenicity. These data illustrate the importance and feasibility of human hepatocyte banking. 相似文献
3.
Ziora D Sielska-Spytek E Dworniczak S Oklek K Kozielski J 《Pneumonologia i alergologia polska》2002,70(9-10):458-467
The purpose of this study was comparison of VEGF (vascular endothelial growth factor) levels in serum and pleural fluid and estimation of this test usefulness in diagnosis of pleural effusions. VEGF levels were measured by ELISA method in 68 patients (45 males and 23 females) aged 19-81 years. By Light's criteria in 16 cases transudate and in 52 cases exudate was recognized. By means of fluid cytology, pleural biopsy, microbiology or thoracoscopy in 10 cases pleural metastases from distant organs, in 15 cases coexisting pulmonary neoplasm, in 11 cases mesothelioma and in 16 cases tuberculosis were determined as a cause of fluid accumulation in pleural space. The mean VEGF levels were significantly higher (p < 0.001) in patients with exudates than in patients with transudates (3833 pg/ml and 325 pg/ml respectively). Based on likelihood ratios analysis, as a cut off value in differentiation of exudates and transudates a value 700 pg/ml was accepted. The sensitivity of this test was 75% and the specificity 93% and likelihood ratio (LR) 12.5. The mean VEGF level in exudates was seven times higher than mean VEGF level in serum (3833 pg/ml and 573 pg/ml respectively). Mean VEGF levels in malignant exudates (4615 pg/ml) were significantly higher than in tuberculous exudates (2073 pg/ml). As a cut off value in differentiation between malignant and tuberculous exudates a value of 4500 pg/ml was accepted. We conclude that our results suggests the local VEGF production in pleural cavity and the significant role of this cytokine in pleural exudates accumulations and also suggests the usefulness of VEGF estimation in pleural fluid in differentiation transudates from exudates and malignant from tuberculous pleural fluids. 相似文献
4.
Olszyna DP Prins JM Dekkers PE De Jonge E Speelman P Van Deventer SJ Van Der Poll T 《Journal of clinical immunology》1999,19(6):399-405
Chemokines are a superfamily of small chemotactic proteins. While increased levels of interleukin-8 have been measured in serum and urine during urinary tract infection, little is known about other chemokines in this condition. Monocyte chemoattractant protein (MCP)–1, macrophage inflammatory protein (MIP)–1, MIP-1 and interferon- inducible protein (IP)–10 were measured in 30 patients with culture-proven urosepsis during a 3-day follow-up and in 11 healthy humans after intravenous injection of endotoxin (4 ng/kg). Urine and serum levels of MCP-1, MIP-1, and IP-10, but not of MIP-1, were elevated in patients on admission, and decreased after initiation of antibiotic treatment. Endotoxin administration to healthy subjects induced increases in plasma and urine concentrations of all four chemokines. These data indicate that clinical and experimental gram-negative infection in humans is associated with enhanced production of chemokines that act mainly on mononuclear cells and that these chemokines are at least in part locally produced. 相似文献
5.
INTRODUCTION: Previous ex vivo experiments by others suggest that elevated body temperature can prime the respiratory burst of human neutrophils. The mechanism of the priming phenomenon induced by temperature has not been addressed so far. Furthermore, the priming temperature range was not defined. MATERIAL/METHODS: In the present study we explored ,under in vitro conditions, the influence of febrile-range temperatures on reactive oxygen species (ROS)generation by human peripheral blood neutrophils. ROS production was measured using whole.blood luminol-dependent chemiluminescence. Two elements of signal transduction pathways, calcium and p38 mitogen.activated protein kinase alpha (p38MAPKalpha) ,frequently underlying neutrophil priming were also examined.Calcium levels in the cytosol of resting and fMLP. stimulated isolated neutrophils were measured with the Fura-2AM spectrofluorimetric method. The activity of p38MAPKalpha was assessed indirectly with a specific inhibitor of the kinase, SB 203580. RESULTS: The study revealed a priming effect at 38 degrees C toward human peripheral blood neutrophil ROS production. Any concomitant effect on calcium response was not observed. Instead, experiments with SB 203580,a specific inhibitor of p38MAPKalpha, pointed to an increased activity of the kinase as a molecular background of temperature-induced priming. However, the priming effect of temperature was confined to 38 degrees C, while higher temperatures proved to exert no effect (39 and 40 degrees C)or even inhibited ROS generation by neutrophils (43 degrees C). CONCLUSIONS: Our study suggests a heterogeneous influence of temperature on human neutrophil functioning, including the priming of the cells by a low-febrile-range temperature. It also suggests a p38MAPKalpha-dependent molecular background of the priming phenomenon. 相似文献
6.
Splenic metastasis from lung cancer is a rare clinical event, most often diagnosed at the time of an autopsy. We report a case of a 68 year old man with splenic metastasis from the primary lung cancer. Staging procedures before the resection of the primary lung tumor detected the splenic lesion. Upper left lobectomy and splenectomy were done by the left postero-lateral thoracotomy with phrenotomy. The rarity of solitary spleen metastasis from lung cancer and the treatment are discussed. 相似文献
7.
Krzyzak AT Jasiński A Weglarz WP Adamek D Sagnowskil P Baj M 《Acta neurobiologiae experimentalis》2005,65(3):255-264
Magnetic Resonance Diffusion Tensor Imaging (DTI) of the control and traumatic injured spinal cord of a rat in vitro is reported. Experiments were performed on excised spinal cords from 10 Wistar rats, using a home-built 6.4 T MR microscope. MRI and histopathological results were compared. Presented results show that DTI of the spinal cord, perfused with formalin 10 minutes after the injury, can detect changes in water diffusion in white matter (WM) and in gray matter (GM), in areas extending well beyond the region of direct impact. Histology of neurons of the GM shows changes that can be attributed to ischemia. This is in agreement with the observed decrease of diffusion in the injured regions, which may be attributed to the cytotoxic edema due to ischemia. However, the diffusion changes in highly anisotropic WM seem to be caused by a direct action of mechanical force of impact, which significantly distorts the nerve fibers. 相似文献
8.
Treatment with continuous positive airway pressure may affect blood glucose levels in nondiabetic patients with obstructive sleep apnea syndrome 总被引:5,自引:0,他引:5
STUDY OBJECTIVES: Obstructive sleep apnea syndrome (OSAS) is often associated with impaired glucose metabolism. Data on the effects of OSAS treatment with continuous positive airway pressure (CPAP) on blood glucose and insulin resistance are conflicting. The study aimed at assessing the immediate effect of CPAP on glucose control measured with a continuous glucose monitoring system (CGMS). PARTICIPANTS AND MEASUREMENTS: Nine non-diabetes subjects with OSAS (mean age 53.0 +/- 8.0 years; body mass index 34.8 +/- 5.3 kg/m2) underwent 2 overnight polysomnographic examinations: a diagnostic study and one with CPAP treatment. Continuous glucose monitoring system (CGMS) was applied overnight on both occasions. Glucose metabolism was assessed with a 75-g oral glucose tolerance test, plasma insulin and homeostatic model assessment of insulin resistance (HOMA-IR) index. RESULTS: The mean (+/- SD) apnoea-hypopnea index (AHI) at diagnostic polysomnography was 54.3 +/- 29.3 (range 16-81). Fasting plasma insulin levels in patients with OSAS was 84.3 +/- 43.4 pM at baseline, and the HOMA-IR was 3.6 +/- 2.2. CPAP treatment in the subjects with OSAS resulted in a significant reduction in the AHI to 4.5 +/- 7.1. All of the major saturation parameters improved significantly on CPAP. CGMS showed mean glucose values significantly higher during the CPAP night than during the diagnostic night: 80 +/- 11 mg/dL versus 63 +/- 7 mg/dL (P < .01). Fasting insulin and HOMA-IR measured after the CPAP night tended to be higher than at baseline (98.4 +/- 51.0 pmol vs 84.3 +/- 43.4 pmol and 3.9 pmol +/- 2.6 vs 3.6 +/- 2.2 pmol, respectively, P > .05). CONCLUSION: CPAP treatment in nondiabetic obese patients with OSAS may have an immediate elevating effect on blood glucose. 相似文献
9.
Micha Oczkowski Katarzyna Dziendzikowska Anna Pasternak-Winiarska Dariusz Wodarek Joanna Gromadzka-Ostrowska 《Nutrients》2021,13(2)
Due to the constantly increasing number of cases, prostate cancer has become one of the most important health problems of modern societies. This review presents the current knowledge regarding the role of nutrients and foodstuff consumption in the etiology and development of prostate malignancies, including the potential mechanisms of action. The results of several in vivo and in vitro laboratory experiments as well as those reported by the clinical and epidemiological research studies carried out around the world were analyzed. The outcomes of these studies clearly show the influence of both nutrients and food products on the etiology and prevention of prostate cancer. Consumption of certain nutrients (saturated and trans fatty acids) and food products (e.g., processed meat products) leads to the disruption of prostate hormonal regulation, induction of oxidative stress and inflammation, and alteration of growth factor signaling and lipid metabolism, which all contribute to prostate carcinogenesis. On the other hand, a high consumption of vegetables, fruits, fish, and whole grain products exerts protective and/or therapeutic effects. Special bioactive functions are assigned to compounds such as flavonoids, stilbenes, and lycopene. Since the influence of nutrients and dietary pattern is a modifiable risk factor in the development and prevention of prostate cancer, awareness of the beneficial and harmful effects of individual food ingredients is of great importance in the global strategy against prostate cancer. 相似文献
10.