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排序方式: 共有211条查询结果,搜索用时 31 毫秒
61.
Sylwia Czonka Agn Kairyt Karolina Miedziska Anna Strkowska Agnieszka Adamus-Wodarczyk 《International journal of molecular sciences》2021,22(7)
Rigid polyurethane (PUR) foams reinforced with 1, 2, and 5 wt.% of salvia filler (SO filler) and montmorillonite-modified salvia filler (MMT-modified SO filler) were produced in the following study. The impact of 1, 2, and 5 wt.% of SO filler and MMT-modified SO filler on the morphological, chemical, and mechanical properties of PUR composites were examined. In both cases, the addition of 1 and 2 wt.% of SO fillers resulted in the synthesis of PUR composites with improved physicomechanical properties, while the addition of 5 wt.% of SO fillers resulted in the formation of PUR composites with a less uniform structure and, therefore, some deterioration in their physicomechanical performances. Moreover, the results showed that the modification of SO filler with MMT improved the interphase compatibility between filler surface and PUR matrix. Therefore, such reinforced PUR composites were characterized by a well-developed closed-cell structure and improved mechanical, thermal, and flame-retardant performances. For example, when compared with reference foam, the addition of 2 wt.% of MMT-modified SO filler resulted in the formation of PUR composites with greater mechanical properties (compressive strength, flexural strength) and improved dynamic-mechanical properties (storage modulus). The PUR composites were characterized by better thermal stability as well as improved flame retardancy—e.g., decreased peak rate of heat release (pHRR), reduced total smoke release (TSR), and increased limiting oxygen index (LOI). 相似文献
62.
J Corrette-Bennett M Rosenberg M Przybylska E Ananiev D Straus 《Canadian Metallurgical Quarterly》1998,26(7):1812-1818
The ability to isolate genes defined by mutant phenotypes has fueled the rapid progress in understanding basic biological mechanisms and the causes of inherited diseases. Positional cloning, a commonly used method for isolating genes corresponding to mutations, is most efficiently applied to the small number of model organisms for which high resolution genetic maps exist. We demonstrate a new and generally applicable positional cloning method that obviates the need for a genetic map. The technique is based on Restriction Fragment Length Polymorphism (RFLP) Subtraction, a method that isolates RFLP markers spanning an entire genome. The new method, Targeted RFLP Subtraction (TRS), isolates markers from a specific region by combining RFLP Subtraction with a phenotypic pooling strategy. We used TRS to directly isolate dense markers tightly linked to the regA gene of the eukaryotic green alga Volvox. As a generally applicable method for saturating a small targeted region with DNA markers, TRS should facilitate gene isolation from diverse organisms and accelerate the process of physically mapping specific regions in preparation for sequence analysis. 相似文献
63.
M. Luke Murray E. Hugo Seymour Jan Rogut Sylwia W. Zechowska 《International Journal of Hydrogen Energy》2008
Poland has significant reserves of energy in the form of coal. However, the exploitation of these reserves could lead to significant carbon emissions. Hydrogen technologies present a potentially sustainable option for the Polish energy system. This paper reviews the existing Polish energy system, resources, policies and measures from the perspective of planning a transition to a hydrogen-based economy. The key challenges and opportunities gathered by systematic consultation of senior stakeholders are presented. Coke oven gas and coal gasification are the major short and medium term sources of hydrogen. Underground conversion of coal deposits with integrated carbon capture and storage (CCS) is most important in the long term. Other opportunities include development of renewables, by-product hydrogen and nuclear power. Current lack of infrastructure, particularly for CCS, hydrogen pipelines and clean coal is seen as a significant barrier. Regional and central government should cooperate with industry to develop a portfolio of demonstration projects to provide experience and stimulate demand for hydrogen. 相似文献
64.
Marta Weronika Lato Anna Przysucha Sylwia Grosman Joanna Zawitkowska Monika Lejman 《International journal of molecular sciences》2021,22(9)
Childhood acute lymphoblastic leukemia is a genetically heterogeneous cancer that accounts for 10–15% of T-cell acute lymphoblastic leukemia (T-ALL) cases. The T-ALL event-free survival rate (EFS) is 85%. The evaluation of structural and numerical chromosomal changes is important for a comprehensive biological characterization of T-ALL, but there are currently no genetic prognostic markers. Despite chemotherapy regimens, steroids, and allogeneic transplantation, relapse is the main problem in children with T-ALL. Due to the development of high-throughput molecular methods, the ability to define subgroups of T-ALL has significantly improved in the last few years. The profiling of the gene expression of T-ALL has led to the identification of T-ALL subgroups, and it is important in determining prognostic factors and choosing an appropriate treatment. Novel therapies targeting molecular aberrations offer promise in achieving better first remission with the hope of preventing relapse. The employment of precisely targeted therapeutic approaches is expected to improve the cure of the disease and quality of life of patients. These include therapies that inhibit Notch1 activation (bortezomib), JAK inhibitors in ETP-ALL (ruxolitinib), BCL inhibitors (venetoclax), and anti-CD38 therapy (daratumumab). Chimeric antigen receptor T-cell therapy (CAR-T) is under investigation, but it requires further development and trials. Nelarabine-based regimens remain the standard for treating the relapse of T-ALL. 相似文献
65.
Cooperation is a cognitively demanding, complex social behavior, found primarily in primates. Here we investigated mutualism in rats (Rattus Norvegicus), a simple form of cooperation in which two subjects work on operant task, receiving immediate and simultaneous sucrose reward for a joint action. To receive the sucrose reward, familiar pairs of rats were required to nose poke simultaneously. Following 44 training days, we examined the relation of social contact and ultrasonic vocalizations to the rat's cooperative behavior by testing the effects of inserting opaque, wire-mesh, or no partition - between subjects. Cooperative behavior (simultaneous nose-poking): (a) increased gradually during initial training; (b) decreased with the opaque partition (restricting visual, acoustic, and physical communication); (c) increased with a wire mesh partition restricting only physical contact); and (d) increased with the number of 50 kHz USV “happy” calls and the intensity of social interaction. The possibility of studying the development of cooperative behavior in laboratory rats using a simple procedure based on commercially available equipment may prove useful in modeling determinants of social behavior. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
66.
67.
Andrzej Zieliński Sylwia Sobieszczyk 《International Journal of Hydrogen Energy》2011,36(14):8619-8629
The zirconium alloys used in nuclear industry include mainly Zr-Sn and Zr-Nb alloys of different chemical composition, microstructure and susceptibility to both hydrogen degradation and oxidation. The hypothetic nuclear accidents can create a real danger to the Zr alloys and stability of parts made of these alloys, and especially such as loss of coolant accident (LOCA) and reactivity initiated accidents (RIA). The hydrogen degradation can manifest itself in an appearance of hydride phases resulting in a substantial loss of plasticity, an increase in ductile-brittle transition, sometimes in a decrease in mechanical strength. The oxidation can prevent the hydrogen entry but at high temperatures the cracking of the oxide layer can form the easy hydrogen diffusion channels. Based on a substantial number of tests made so far and well-known thermodynamic and kinetic parameters, the general microstructure-dependent and temperature-dependent degradation model considering both hydrogen and oxidation could be elaborated. 相似文献
68.
Pawel Niemiec Tomasz Nowak Tomasz Iwanicki Sylwia Gorczynska-Kosiorz Anna Balcerzyk Jolanta Krauze Wladyslaw Grzeszczak Maria Wiecha Iwona Zak 《International journal of molecular sciences》2015,16(6):13203-13216
Single nucleotide polymorphisms (SNPs) of the USF1 gene (upstream stimulatory factor 1) influence plasma lipid levels. This study aims to determine whether USF1 SNPs interact with traditional risk factors of atherosclerosis to increase coronary artery disease (CAD) risk. In the present study serum lipid levels and USF1 gene polymorphisms (rs2516839 and rs3737787) were determined in 470 subjects: 235 patients with premature CAD and 235 controls. A trend of increasing triglycerides (TG) levels in relation to the C allele dose of rs2516839 SNP was observed. The synergistic effect of cigarette smoking and C allele carrier state on CAD risk was also found (SIM = 2.69, p = 0.015). TG levels differentiated significantly particular genotypes in smokers (1.53 mmol/L for TT, 1.80 mmol/L for CT and 2.27 mmol/L for CC subjects). In contrast, these differences were not observed in the non-smokers subgroup (1.57 mmol/L for TT, 1.46 mmol/L for CT and 1.49 mmol/L for CC subjects). In conclusion, the rs2516839 polymorphism may modulate serum triglyceride levels in response to cigarette smoking. Carriers of the C allele seem to be particularly at risk of CAD, when exposed to cigarette smoking. 相似文献
69.
Krishna Priya Arjunan Virender K. Sharma Sylwia Ptasinska 《International journal of molecular sciences》2015,16(2):2971-3016
Atmospheric Pressure Plasma (APP) is being used widely in a variety of biomedical applications. Extensive research in the field of plasma medicine has shown the induction of DNA damage by APP in a dose-dependent manner in both prokaryotic and eukaryotic systems. Recent evidence suggests that APP-induced DNA damage shows potential benefits in many applications, such as sterilization and cancer therapy. However, in several other applications, such as wound healing and dentistry, DNA damage can be detrimental. This review reports on the extensive investigations devoted to APP interactions with DNA, with an emphasis on the critical role of reactive species in plasma-induced damage to DNA. The review consists of three main sections dedicated to fundamental knowledge of the interactions of reactive oxygen species (ROS)/reactive nitrogen species (RNS) with DNA and its components, as well as the effects of APP on isolated and cellular DNA in prokaryotes and eukaryotes. 相似文献
70.
Natural deep eutectic solvents (NADES) are promising green solvents for the extraction of compounds from natural products. This is the first study to use a sample preparation method based on NADES for the extraction of flavonoids (rutin, hesperidin, neohesperidin, naringenin, naringin, quercetin, hesperetin, and chrysin) from fruits, vegetables, and spices. In total, 17 types of NADES based on choline chloride, acetylcholine chloride, choline tartrate, betaine, and carnitine with different compositions were tailored to test their extraction efficiency. Operational conditions such as water content in NADES and liquid/solid ratios were also studied. A response surface methodology was used for multivariate optimization of some extraction parameters. Efficient recovery of extracted flavonoids (higher than 70%) was achieved using a 30% water solution of acetylcholine chloride/lactic acid ratio (2:1) as an extraction solvent. Other conditions for SLE-NADES were as follows: liquid/solid ratio 3:1, extraction temperature 60 °C, extraction time 30 min, and stirring speed 1400 rpm. Each extract was analyzed by UHPLC with UV and MS/MS detection. The developed method was applied for analysis of flavonoids in fruits (cranberry, fruits of Lycium barbarum L., grape, plum, and orange peel), vegetables (onion and broccoli), and spices (mustard, rosemary, and black pepper). 相似文献