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21.
IntroductionThe purpose of this study was to investigate the characteristics and the outcome of bicycle injuries in paediatric patients according to the living environment, and to create guidelines for injury prevention.PatientsThe evaluation was performed in part based on hospital database of 1803 in- and out-patient children treated at the Paediatric Surgical Department of Pécs/Hungary between 2000 and 2006, and at the Department of Paediatric Surgery at the Heim Pal Hospital Budapest between 2004 and 2006. Additionally questionnaires were mailed to the patients’ families to gain follow-up information. We analysed three groups according to demographic density (village, midsize town and large town).ResultsWe found, that poor road quality played an important role as a contributing factor of injuries in villages. The number of bicycle spoke-injuries was higher in villages (13%), than in midsize towns (4.6%) and the large town (9.9%). In villages, 5% of children injured wore a helmet; this rate was 9% in midsize towns and 9.1% in the large town. Head injury was more common in villages, while in midsize towns and the large town arm injuries proved to be predominant.DiscussionPrevention strategies targeting bicycle injuries in children should take into account the population density. This analysis revealed a substantial difference in the use of safety devices, and in the characteristics of injuries occurring in villages, indicating that there is a need for special attention regarding this higher risk population.  相似文献   
22.
Co-Re alloy development is prompted by the search for new materials for future gas turbines which can be used at temperatures considerably higher than the current day single crystal Ni-based superalloys. The Co-Re-based alloys have been designed to have very high melting range, and they are meant for application at +373 K (+100 °C) above Ni-superalloys. They are significantly different from the conventional Co-based alloys that are used in static components of today??s gas turbines, and the Co-Re alloys have never been used for structural applications before. The Co-Re-Cr system has complex microstructure with many different phases present. Phase transformations and stabilities of fine strengthening precipitates at high temperatures remain mostly unexplored in the Co-Re alloys, and to develop basic understanding, model ternary and quaternary compositions were studied within the alloy development program. In situ neutron and synchrotron measurements at high temperatures were extensively used for this purpose, and some recent results from the in situ measurements are presented. In particular, the effect of boron doping in Co-Re alloys and the stabilities of the fine TaC precipitates at high temperatures were investigated. A fine dispersion of TaC precipitates strengthens some Co-Re alloys, and their stabilities at the application temperatures are critical. In the beginning, the alloy development strategy is very briefly discussed.  相似文献   
23.
A reversed phase liquid chromatographic–tandem mass spectrometric method with simple solvent extraction and purification by solid phase extraction (SPE) has been developed for the determination of coccidiostats in milk. For sample preparation matrix solid phase dispersion, extraction by organic solvent and SPE with different cartridges were also tested. The compounds determined include lasalocid, narasin, salinomycin, monensin, semduramicin, maduramicin, robenidine, decoquinate, halofuginone, nicarbazin and diclazuril. Main steps of the method are addition of acetonitrile to the milk samples, centrifugation, removal of matrix by SPE, concentration by evaporation and LC–MS–MS determination. During a 15 min time segmented chromatographic run compounds are ionised either positively or negatively. Calculated recoveries range between 77.1% and 118.2%. Maximum levels are in the range of 1–20 μg/kg. The developed method was validated in line with the requirements of Commission Decision 2002/657/EC (2002). It is applicable for control of coccidiostat residues in milk as indicated in Regulation 124/2009/EC (2009).  相似文献   
24.
For detection and quantification of food proteins triggering hypersensitivity reactions, reliable, validated analytical methods are necessary. At present, the most commonly used methodology for this purpose is ELISA. The lack of incurred reference materials (RM) complicates the fulfilling of method validation. Today, a well identifiable research direction is the development of methods (immunoanalytical, PCR and MS methods) suitable for multi-component analysis. As a consequence of these R+D efforts, the development of multi-component RMs is reasonable. Our work presented here is focusing on the development and investigation of multi-component model food matrices that can be suitable for supporting the validation processes. On the basis of the relative incidence of hypersensitivity reactions, four components—wheat, milk, egg and soy—were selected for our preliminary work. The target proteins were determined in single- and multi-component matrices with different ELISA methods, and the results were compared by statistical evaluation. The main direction of our investigation was to identify the effects of the potential interactions of these proteins on the analytical results, and the influence of food processing was also investigated. The results showed that the presence of multiple allergenic components caused much less uncertainty in the analytical results than analytical and technological steps, such as sample preparation, repetition or even heat treatment. However, probably due to the relatively complex matrices, some discrepancies from the expected outcome could also be observed.  相似文献   
25.
Dietary methyl-donors play important roles in physiological processes catalyzed by B vitamins as coenzymes, and are used for complementary support in oncotherapy. Our hypothesis was that methyl-donors can not only assist in tolerating cancer treatment but may also directly interfere with tumor growth and proliferation. Therefore, we investigated the proposed cancer inhibitory effects of methyl-donors (in a mixture of L-methionine, choline chloride, folic acid, and vitamin B12) on MCF7 and T47D breast cancer as well as A549 and H1650 lung cancer cell lines. Indeed, methyl-donor treatment significantly reduced the proliferation in all cell lines, possibly through the downregulation of MAPK/ERK and AKT signaling. These were accompanied by the upregulation of the pro-apoptotic Bak and Bax, both in MCF7 and H1650 cells, at reduced anti-apoptotic Mcl-1 and Bcl-2 levels in MCF7 and H1650 cells, respectively. The treatment-induced downregulation of p-p53(Thr55) was likely to contribute to protecting the nuclear localization and apoptosis inducing functions of p53. The presented features are known to improve the sensitivity of cancer therapy. Therefore, these data support the hypothesis, i.e., that methyl-donors may promote apoptotic signaling by protecting p53 functions through downregulating both the MAPK/ERK and the AKT pathways both in breast and lung adenocarcinoma cell lines. Our results can emphasize the importance and benefits of the appropriate dietary supports in cancer treatments. However, further studies are required to confirm these effects without any adverse outcome in clinical settings.  相似文献   
26.
Endocannabinoids and their receptors are present in the cardiovascular system; however, their actions under different pathological conditions remain controversial. The aim of our study was to examine the effects of anandamide (AEA) on heme oxygenase (HO) and nitric oxide synthase (NOS) systems in an estrogen-depleted rat model. Sham-operated (SO) and surgically induced estrogen-deficient (OVX) female Wistar rats were used. During a two-week period, a group of OVX rats received 0.1 mg/kg estrogen (E2) per os, while AEA-induced alterations were analyzed after two weeks of AEA treatment at the dose of 1.0 mg/kg. At the end of the experiment, cardiac activity and expression of HO and NOS enzymes, content of cannabinoid 1 receptor, as well as concentrations of transient potential vanilloid 1 (TRPV1) and calcitonin gene-related peptide (CGRP) were measured. Our results show that estrogen withdrawal caused a significant decrease in both NOS and HO systems, and a similar tendency was observed regarding the TRPV1/CGRP pathway. Two weeks of either AEA or E2 treatment restored the adverse changes; however, the combined administration of these two molecules did not result in a further improvement. In light of the potential relationship between AEA and HO/NOS systems, AEA-induced upregulation of HO/NOS enzymes may be a therapeutic strategy in estrogen-deficient conditions.  相似文献   
27.
The degradation reaction kinetics and chemical mechanism of phenol decomposition by ozonation, TiO2-photocatalysis and vacuum ultraviolet (VUV) photolysis were investigated. The concentration dependences of the aromatic and aliphatic intermediates and the TOC content were compared as a function of the phenol conversion. The concentration profiles and the TOC curves obtained with each method were very similar. The results suggest a similar chemical mechanism for the transformation of phenol irrespective of the starting active component (a positive hole on the surface of the catalysts, a VUV photon, ozone or the hydroxyl radical).  相似文献   
28.
29.
A time-dependent Monte Carlo algorithm was employed to study the effects of carbonaceous surface species on the hydrogenation mechanism of acetylene–ethylene mixtures on a Pd catalyst. Simulations of tail-end and front-end mixture hydrogenation were performed employing the same set of predetermined event probabilities. The involvement of the steric hindrance of the surface species was essential to simulate the experimental data. The catalyst activity and selectivity were promoted or inhibited by different concentrations of surface polymeric species formed along with the hydrocarbon hydrogenation. Tools to get a new interpretation of the catalytic reaction mechanism and an innovative basis to perform catalyst design were suggested by the approach illustrated.  相似文献   
30.
Scientometrics - The paper investigates the reference corpus of a climate change contrarian report. We categorized the journal abstracts according to the endorsement positions on anthropogenic...  相似文献   
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