关键词： Applied and Technical Physics   Theoretical   Mathematical and Computational Physics   Complex Systems   Condensed Matter Physics   Atomic   Molecular   Optical and Plasma Physics  

摘要： We have discussed here a higher dimensional cosmological model and explained the recent acceleration with a Chaplygin type of gas. Dimensional reduction of extra space is possible in this case. Our solutions are general in nature because all the well known results of 4D Chaplygin driven cosmology are recovered when d = 0. We have drawn the best fit graph using the data obtained by the differential age method and it is seen that the graph favours only one extra dimension. That means the Chaplygin gas is apparently dominated by a 5D world. Relevant to point out that the final equation in this case are highly nonlinear in nature. Naturally it is not possible to obtain explicit solution of the 4D scale factor with time. To circumvent this difficulty, we consider a first order approximation of the key equation which has made it possible to get time explicit solution of 4D scale factor in exact form as well as the expression of extra dimensions. It may be pointed out that for large four dimensional scale factor this solution mimics ACDM model. An analysis of flip time is also studied both analytically and graphically in some detail. It clearly shows that early flip occurs for higher dimensions. It is also seen that the rate of dimensional reduction is faster for higher dimensions. So we may conclude that the effect of compactification of extra dimension helps the acceleration.

关键词： Chromium nitride   Sputtering   Minting dies   Nano-impact   Fatigue  

摘要： Aiming to improve the protection of human health and the environment, REACH regulation was enforced across European Union, accelerating the need to find alternative solutions to the electrodeposition processes of hexavalent chromium employed in several industrial applications. Electroplated chromium coatings are widely used due to their physical and mechanical properties that allow a longer service life of products that usually fail due to wear. Minting is one of those applications where good mechanical and tribological properties are required and where hard chromium has an important usage without being outmatched by other coatings. This study presents the development of an alternative coating to hard chromium with outstanding mechanical properties, in particular high resistance to cyclic loads. Cr(Al,Si)N coatings have been produced by reactive DC magnetron sputtering. Focusing on mechanical properties, an increase in the hardness was observed with the consecutive addition of elements to the base matrix (CrN), ranging from approximate to 10 GPa in CrN coatings up to approximate to 17 GPa for the CrAlSiN coatings. In nano-impact tests, CrAlN coatings had the best performance and no crack events by fatigue were observed by SEM after 50 impacts, with load maximum 20mN, with an estimated maximum contact pressure of 1.5 GPa much higher than the one requested for coinage. The fatigue wear was governed by the H/E ratio and plasticity index showing that Cr(Al,Si)N coatings deposited by reactive magnetron sputtering can be considered excellent candidates for cyclic loading, as in minting applications.

关键词： Bark   Ionic liquids   Extraction   Flavonoids   Energetic analysis  

摘要： Tree barks are rich in extractive compounds, among which the flavonoids are considered as products of interest. Due to the increase in the demand for these natural products, the development of efficient and sustainable extraction processes is needed. This work aimed to study the selective extraction of flavonoids from Larix decidua bark using an environmentally friendly process. For this purpose, different extraction techniques as well as different solvents were used in order to achieve the highest flavonoid content. The characterisation results revealed improvements in extraction yield not only with the use of intensification processes, but also with the use of ionic liquids as solvents with a proven selectivity for flavonoids. [C4C1im]Br and [C4C1im][BF4] considerably improved the total flavonoid content in comparison with the other extraction methods. The antioxidant capacities of all the extracts obtained were very high, confirming their potential for different applications. The [C4C1im]Br (25 wt%) was selected as the best solvent not only because of its good flavonoid extraction ability, but also because of the good antioxidant properties of the extract, and simultaneous microwave-ultrasound assisted extraction was the most energy saving process.

关键词： 头孢菌素类药物   联合   其他药物   不良反应   对策  

摘要： 目的 分析头孢菌素类药物联合其他药物所致的不良反应及相应对策.方法 将2019年3月至2010年3月期间在我院使用头孢菌素类药物联合其他药物进行治疗之后出现不良反应的90例病患作为本次研究的研究对象.结果 年龄高于六十岁的病患治疗后发生不良反应的概率为52.64％,第三代头孢菌素类药物发生不良反应的概率为47.92％,出现不良反应的原因为联合用药不当,主要的不良反应为神经系统反应.结论 在临床治疗中使用头孢菌素类药物对病患进行治疗,应当提前对其适应症进行充分的了解,同时考虑病患的年龄等相关因素,继而确保用药治疗的安全性,降低不良反应发生的概率.

关键词： coronary artery   aneurysm   pediatric inflammatory multisystem syndrome  

关键词： HO1   alternative polyadenylation   adipogenesis   microRNAs  

摘要： Appropriately increasing intramuscular fat content can help improve meat quality, so it is necessary to explore the internal molecular mechanism of preadipocyte differentiation. The role of heme oxygenase 1 (HO1) in cell oxidative stress, energy metabolism, cell proliferation, and differentiation has gradually been revealed. Here, we used 3'RACE to identify the full-length 3' untranslated region (3'UTR) of HO1 and found that a very short 3'UTR variant was produced by alternative polyadenylation (APA). HO1 with a long 3'UTR variant was identified as a direct target of miR155-5P and miR377-3P. Our experimental results verified the inhibitory effect of HO1 on preadipocyte differentiation. In addition, our research confirms that by escaping microRNA inhibitory effects, the HO1 3'UTR short variant produced by APA has a higher level of expression. Thus, the HO1 3'UTR short variant has a stronger inhibitory effect on the preadipocyte differentiation than the HO1 3'UTR long variants in 3T3-L1.

关键词： 输血   凝聚胺   效果   对比  

摘要： 对比临床输血中凝聚胺技术与其他输血技术的应用效果。方法:选取2019年10月—2020年12月于我院收治的需要进行输血的患者500例,采用随机分组的方法将患者分成两组各250人,分别为对照组和实验组,对照组采用的是常规的输血模式,实验组采取凝聚胺技术进行输血,在输血结束后,比较对照组与实验组两组患者不良反应发生率和相互交叉配血相合率。结果:实验组的不良反应发生率显著低于对比组(P<0.05),实验组相互交叉配血相合率为92.80%,明显高于对照组82.4%(P<0.05)。结论:临床输血中凝聚胺技术较其他输血技术,患者不良反应发生率更低,且相互交叉配血相合率更高,因此具有临床推广价值。

关键词： Atmospheric chemistry   Bond cleavage   Ethers   Particulate matter   Computer simulations  

摘要： An increasing number of alternative flame retardants (FRs) are being introduced, following the international bans on the use of polybrominated diphenyl ether (PBDE) commercial mixtures. FRs' production capacity has shifted from developed countries to developing countries, with China being the world's largest producer and consumer of FRs. These chemicals are also imported with e-waste to China. Therefore, it is important to understand the current status of regulated brominated FRs, their phase-out in China, and their replacement by alternatives. In this study, a broad suite of legacy and alternative FRs, including eight PBDEs, six novel brominated FRs (NBFRs), two dechlorane plus variants (DPS), and 12 organophosphate FRs (OPFRs) were evaluated in the air of 10 large Chinese cities in 2018. OPFRs are the most prevalent FRs in China, exhibiting a wide range of 1-612 ng/m(3), which is several orders of magnitude higher than PBDEs (1-1827 pg/m(3)) and NBFRs (1-1428 pg/m(3)). BDE 209 and DBDPE are the most abundant compounds in brominated FRs (>80%). The North China Plain (NCP, excluding Beijing), Guangzhou, and Lanzhou appear to be three hotspots, although with different FR patterns. From 2013/2014 to 2018, levels of PBDEs, NBFRs, and DPs have significantly decreased, while that of OPFRs has increased by 1 order of magnitude. Gas-particle partitioning analysis showed that FRs could have not reached equilibrium, and the steady-state model is better suited for FRs with a higher log K-OA (>13). To facilitate a more accurate FR assessment in fine particles, we suggest that, in addition to the conventional volumetric concentration (pg/m(3)), the mass-normalized concentration (pg/g PM2.5) could also be used.

关键词： Food waste   Anaerobic digestion   Biogas   Resource utilization   Perspectives  

摘要： With the implementation of zero-waste city and waste classification in China, a large amount of food waste (FW) began to appear in concentration, and there was an urgent requirement for appropriate and efficient treatment technology. Traditional FW disposal methods (landfill and incineration) could cause several environmental problems, so resource recycling has become the main development trend of FW in China. In recent years, anaerobic digestion (AD) technology for FW resource treatment has attracted much attention due to its advantages such as the ability to obtain clean energy, low carbon emissions, and suitability for large-scale treatment compared with other recycling technologies (composting, feed, and breeding insects). Chinese policy is conducive to the development of AD for FW, which has the potential to produce methane and achieve economic and environmental benefits. This paper presents an overview of the researches, application situations, and perspectives for the AD of FW resource treatment in China. The bibliometric analysis shows that China has the most interest in the AD of FW compared to other countries, and the amount and characteristics analysis of FW indicates that FW is suitable for treatment by AD. At the same time, this review analyzes the influence factors, methods to promote AD, working mechanism, secondary pollution of AD. Besides, the article introduces and analyzes the current policies, application status, economic and environmental benefits, and problems of AD for FW resource treatment in China. AD is considered as an alternative resource treatment technology for FW, although there are still several problems such as odors, digestate, etc. In the future, China should focus on the reform of management policy, the implementation of the AD circular economy model, and the research of the biorefinery model based on AD technology. (c) 2021 Elsevier B.V. All rights reserved.

关键词： Fertilizer   FFP   Soil Fertility   SSNM   Yield  

摘要： Nepal is a major rice producer of South Asia, feeding more than 20 million people of the country and abroad. However, productivity and profitability of rice are low in Nepal compared to other regional countries. Large yield gaps exist between attainable and farmers' yields and nutrient management is identified as one of the major reasons. Nutrient ExpertVR (NE), a decision-support tool based on site-specific nutrient management (SSNM) principles has been validated and applied in many countries of Asia and Africa as new recommendation protocol for nutrient management in selected crops, including rice. Present study used NEVR Rice as nutrient management protocol in farmers' fields across Terai and mid-hills regions of Nepal during 2014-2018. The study revealed that NE-based fertilizer recommendations resulted in increase in yield over 2.0 *** similar to 1 (p similar to 0.05) and double the profits compared to existing blanket fertilizer recommendation, and farmers' fertilizer practice. Due to large variations in slope, altitude, soil, and management, performance of NEVR varied across locations. Its performance was better in Terai due to flat lands and less variations in soil types, compared to sloping lands and varied soils of mid-hills. NE tool provided adequate guidance to apply the required rate of fertilizer that matched the crop requirement and soil nutrient supply of each farmer fields. The novelty of the study is introduction of a dynamic fertilizer recommendation approach that can supplement the existing static blanket recommendation system. We conclude that Nutrient ExpertVR - Rice can be considered as an effective tool for nutrient recommendation for rice in Nepal.