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151.
Alexander N. Petrov rey Yu. Zuev Tatjana P. Rodionova Vladimir I. Voronin 《Journal of the American Ceramic Society》1999,82(4):1037-1044
The crystal and defect structure of neodymium cerium cu-prate (Nd1.9 Ce0.1 CuO4±y ) has been studied as a function of temperature (1200–1500 K) and oxygen pressure (100 –103 atm) via X-ray diffractometry, powder neutron diffraction, and thermogravimetry methods. The oxygen nonstoichiom-etry changes from oxygen-excess (positive y values) to oxygen- deficient oxides (negative y values). The absolute values of oxygen nonstoichiometry y are calculated from the neu-tron diffraction and thermogravimetry data. The materials adopt the tetragonal structure (space group I 4/ mmm ). A defect model is proposed for Nd2-x Cex CuO4±y . It is con-cluded that oxygen vacancies V Ö (which occupy O(1) crys-tallographic positions (in planes)) and interstitial oxygen O(i (which occupy O(3) "apical" positions) are present simultaneously. Gaseous oxygen intercalates into the Nd1.9 Ce0.1 CuO4±y crystals and replaces oxygen vacancies in the O(1) position and interstitial oxygen atoms in the O(3) positions. The theoretical model and the experimental data are in good agreement with each other, and the equilibrium constants of defect formation have been calculated. 相似文献
152.
Hunke C Hirsch T Eichler J 《Chembiochem : a European journal of chemical biology》2006,7(8):1258-1264
The Mena EVH1 domain, a protein-interaction module involved in actin-based cell motility, recognizes proline-rich ligand motifs, which are also present in the sequence of the surface protein ActA of Listeria monocytogenes. The interaction of ActA with host Mena EVH1 enables the bacterium to actively recruit host actin in order to spread into neighboring cells. Based on the crystal structure of Mena EVH1 in complex with a polyproline peptide ligand, we have generated a range of assembled peptides presenting the Mena EVH1 fragments that make up its discontinuous binding site for proline-rich ligands. Some of these peptides were found to inhibit the interaction of Mena EVH1 with the ligand pGolemi. One of them was further characterized at the level of individual amino acid residues; this yielded information on the contribution of individual positions of the peptides to the interaction with the ligand and identified sites for future structure optimization. 相似文献
153.
154.
A rapid and sensitive liquid chromatography–tandem mass spectrometry method has been developed for the analysis of acephate, monocrotophos, carbendazim, acetamiprid, dimethoate, simazine, carbofuran, atrazine, diuron, DNOC (4,6-dinitro-o-cresol), malathion and tebufenozide in fruit juices. Extracts were obtained by matrix solid-phase dispersion using diatomaceous earth as dispersant and dichloromethane as eluent. Significant matrix effects observed for most of the pesticides tested were eliminated using matrix-matched standards. The quantification of the analytes was carried out using the most sensitive transition. The confirmation of residues detected in real samples was performed by repeated injection and acquiring additional transitions to that used for quantification. Recoveries were in the range 71–118%. Repeatability of the method, expressed as the relative standard deviation, was in general between 5–15%. Low limits of detection (0.01–0.94 ng ml−1) and quantification (0.03–3.12 ng ml−1) were readily achieved with this method for all tested pesticides. 相似文献
155.
Ivana Barišić Sanja Dimter Tatjana Rukavina 《International Journal of Pavement Engineering》2016,17(9):753-762
In this study, we evaluated the elastic and mechanical properties of a new type of cement-stabilised material made with steel slag, varying the content of cement and steel slag. To study the elastic properties of these mixes, we measured their density, compressive strength and ultrasound pulse velocity at curing ages of 7, 28 and 90 days. The aggregate type and curing age greatly affected the elastic properties and varied much depending on the cement content. The Poisson's ratio chosen in analyses had little influence on the dynamic modulus. Various expressions given by building codes were used to predict the elastic properties of the mixtures. These codes generated very different values of the static modulus of elasticity, making most of them unsuitable for predicting the elastic properties of cement-stabilised materials. Using our experimental data, we provide the best combination of existing equations to predict elastic properties, and we conclude that measuring the ultrasound pulse velocity is a suitable way to predict the mechanic and elastic properties of cement-stabilised materials. 相似文献
156.
van Strien Tatjana; van de Laar Floris A.; van Leeuwe Jan F. J.; Lucassen Peter L. B. J.; van den Hoogen Henk J. M.; Rutten Guy E. H. M.; van Weel Chris 《Canadian Metallurgical Quarterly》2007,26(1):105
Objective: To examine whether dieting--restriction of food intake for the purpose of weight control--suppresses or promotes excessive food intake and weight gain. Design: A 4-year follow-up study of a dietary intervention in a sample of 97 patients with newly diagnosed Type 2 diabetes. Main Outcome Measures: Weight gain, change in body mass index (measured weight in kilograms divided by measured height squared), and intake of energy, as measured with a food frequency questionnaire, were assessed in relation to dietary restraint and tendency to overeat (emotionally or externally induced overeating), as assessed with the Dutch Eating Behaviour Questionnaire. Results: Tendency to overeat at diagnosis and not dietary restraint was associated with weight gain and intake of energy 4 years after diagnosis. Conclusion: These findings suggest that the success of a dietary intervention can be predicted by a subject's tendency toward overeating. The possibility of matched treatment of obesity is discussed on the basis of the distinction between patients with a low versus a high tendency to overeat. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
157.
Vladislav Maraš Jasmina Lazić Tatjana Davidović Nenad Mladenović 《Applied Soft Computing》2013,13(8):3515-3528
We investigate the optimization of transport routes of barge container ships with the objective to maximize the profit of a shipping company. This problem consists of determining the upstream and downstream calling sequence and the number of loaded and empty containers transported between any two ports. We present a mixed integer linear programming (MILP) formulation for this problem. The problem is tackled by the commercial CPLEX MIP solver and improved variants of the existing MIP heuristics: Local Branching, Variable Neighborhood Branching and Variable Neighborhood Decomposition Search. It appears that our implementation of Variable Neighborhood Branching outperforms CPLEX MIP solver both regarding the solution quality and the computational time. All other studied heuristics provide results competitive with CPLEX MIP solver within a significantly shorter amount of time. Moreover, we present a detailed case study transportation analysis which illustrates how the proposed approach can be used by managers of barge shipping companies to make appropriate decisions and solve real life problems. 相似文献
158.
Nikola Jovanovi Milica Lazarevi Vladimir J. Cvetkovi Vesna Nikolov Jelena Kosti Peri Milena Ugrin Sonja Pavlovi Tatjana Mitrovi 《International journal of molecular sciences》2022,23(21)
A single-institution observational study with 43 newly diagnosed diffuse gliomas defined the isocitrate dehydrogenase 1 and 2 (IDH1/2) gene mutation status and evaluated the prognostic relevance of the methylation status of the epigenetic marker O6-methylguanine-DNA methyltransferase (MGMT). Younger patients (<50 years) with surgically resected glioma and temozolomide (TMZ) adjuvant chemotherapy were associated with better prognosis, consistent with other studies. The methylation status depends on the chosen method and the cut-off value determination. Methylation-specific PCR (MSP) established the methylation status for 36 glioma patients (19 (52.8%) positively methylated and 17 (47.2%) unmethylated) without relevancy for the overall survival (OS) (p = 0.33). On the other side, real-time methylation-specific PCR (qMSP) revealed 23 tumor samples (54%) that were positively methylated without association with OS (p = 0.15). A combined MSP analysis, which included the homogenous cohort of 24 patients (>50 years with surgical resection and IDH1/2-wildtype diffuse glioma), distinguished 10 (41.6%) methylated samples from 14 (58.4%) unmethylated samples. Finally, significant correlation between OS and methylation status was noticed (p ≈ 0.05). The OS of the hypermethylated group was 9.6 ± 1.77 months, whereas the OS of the unmethylated group was 5.43 ± 1.04 months. Our study recognized the MGMT promoter methylation status as a positive prognostic factor within the described homogenous cohort, although further verification in a larger population of diffuse gliomas is required. 相似文献
159.
Ana Ilic Dusan Todorovic Slavica Mutavdzin Novica Boricic Biljana Bozic Nedeljkovic Sanja Stankovic Tatjana Simic Predrag Stevanovic Vera Celic Dragan Djuric 《International journal of molecular sciences》2021,22(6)
The possible cardioprotective effects of translocator protein (TSPO) modulation with its ligand 4′-Chlorodiazepam (4′-ClDzp) in isoprenaline (ISO)-induced rat myocardial infarction (MI) were evaluated, alone or in the presence of L-NAME. Wistar albino male rats (b.w. 200–250 g, age 6–8 weeks) were divided into 4 groups (10 per group, total number N = 40), and certain substances were applied: 1. ISO 85 mg/kg b.w. (twice), 2. ISO 85 mg/kg b.w. (twice) + L-NAME 50 mg/kg b.w., 3. ISO 85 mg/kg b.w. (twice) + 4′-ClDzp 0.5 mg/kg b.w., 4. ISO 85 mg/kg b.w. (twice) + 4′-ClDzp 0.5 mg/kg b.w. + L-NAME 50 mg/kg b.w. Blood and cardiac tissue were sampled for myocardial injury and other biochemical markers, cardiac oxidative stress, and for histopathological evaluation. The reduction of serum levels of high-sensitive cardiac troponin T hs cTnT and tumor necrosis factor alpha (TNF-α), then significantly decreased levels of serum homocysteine Hcy, urea, and creatinine, and decreased levels of myocardial injury enzymes activities superoxide dismutase (SOD) and glutathione peroxidase (GPx) as well as lower grades of cardiac ischemic changes were demonstrated in ISO-induced MI treated with 4′-ClDzp. It has been detected that co-treatment with 4′-ClDzp + L-NAME changed the number of registered parameters in comparison to 4′-ClDzp group, indicating that NO (nitric oxide) should be important in the effects of 4′-ClDzp. 相似文献
160.
Slobodan M. Cvetković Tatjana Kaluđerović Radoičić Mirjana Kijevčanin Jasmina Grbović Novaković 《International Journal of Hydrogen Energy》2021,46(27):14130-14137
The aim of this paper is to demonstrate and to quantify energy flows in a life cycle of biogas to biohydrogen production, starting from feedstock materials via anaerobic digestion, biogas upgrading, biohydrogen production, to the end of biogas system (application of digestate as fertilizer in agriculture). The performance of the biogas plant of Mirotin dairy farm in Serbia has been assessed. According to Life Cycle Energy Assessment approach, results obtained in this study have shown that biohydrogen production via biogas steam reforming has negative energy balance (with ?16,837 GJ). It has also been demonstrated that this process is energy unsustainable in an environmental context. In future analysis it would be necessary to consider the other aspects of sustainability, e.g. the economical and social factors in order to estimate the overall sustainability of the biogas utilization pathways, especially having in mind that the technology of converting biogas to hydrogen is still in the development phase. 相似文献