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Magda Claeys Wan Wang Reinhilde Vermeylen Ivan Kourtchev Xuguang Chi Yasmeen Farhat Jason D. Surratt Yadian Gómez-González Jean Sciare Willy Maenhaut 《Journal of aerosol science》2010,41(1):13-22
Atmospheric aerosols were collected in separate fine (<2.5 μm) and coarse (>2.5 μm) size fractions in the period December 2006–March 2007 at Amsterdam Island in the southern Indian Ocean. A major objective of the study was to assess biogenic impact on the marine aerosol. The samples were analysed for organic carbon, water-soluble organic carbon, major inorganic ionic species, and organic species, including methanesulphonate (MSA), dicarboxylic acids, and organosulphates. The concentrations of sea salt, non-sea-salt sulphate, and water-soluble and water-insoluble organic matter (WSOM and WIOM) were estimated. Sea salt dominated the composition of the aerosol and accounted for 83% and 91% of the sum of the mass of the four aerosol types in the fine and coarse size fractions, respectively. WSOM, which can serve as a proxy for biogenic secondary organic aerosol (SOA), accounted for only 2.8% of the sum of the mass of the four aerosol types in the fine size fraction. MSA was the dominating organic compound with a median concentration of 47 ng m?3. The organosulphates were characterised as sulphate esters of hydroxyl acids and a dihydroxylaldehyde, which may originate from the oxidation of algal/bacterial unsaturated fatty acid residues. No evidence was found for isoprene SOA. 相似文献
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Heat exchanger tubes of a pressurised water reactor steam generator form part of the boundary between the primary and secondary circuits of the reactor. It is important that no gross breach of this boundary occurs at anytime. Normally the tubes are subjected to internal pressure. However, should a loss of coolant occur in the primary circuit, these tubes are subjected to external pressure.This investigation compares theoretical and experimental results for such tubes, firstly with varying amounts of ovality and secondly with defects artificially induced to simulate: 1, Longitudinal tube cracking; 2, Fretting at tube supports; 3, Erosion.The collapse is compared with the strength of an original perfect tube. Collapse was found to be of a ductile nature in every instance, and in no case did the defect propagate through the wall of the tube.The findings are also of general interest for any externally pressurised tubing. 相似文献
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天然淀粉中含有直链和支链两种形式的α-D-葡聚糖,二者的相对含量不仅与淀粉的糊化、老化、凝胶等理化性质和食品功能有关,还决定着淀粉的经济价值。淀粉直支比定量技术在含淀粉的粮谷类作物育种、淀粉的高值化利用以及食品品质保障和创新等领域具有广泛的应用。本文综述了当前食品科学研究和加工制造领域对淀粉直支比定量技术的需求,介绍和对比了各种经典和新型淀粉直支比定量技术的原理、优缺点和适用性,对淀粉直支比定量技术在未来食品领域的潜在应用提出展望。 相似文献
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Karim Nagi Ishita Gupta Nawaf Jurdi Amber Yasmeen Semir Vranic Gerald Batist Ala-Eddin Al Moustafa 《International journal of molecular sciences》2021,22(15)
Colorectal cancer (CRC) is the third most common cause of cancer-related deaths worldwide. Human papillomaviruses (HPVs) and Epstein–Barr virus (EBV) have been reported to be present in different types of human cancers, including CRCs, where they can play a key role in the onset and/or progression of these cancers. Thus, we herein explored the prevalence of high-risk HPVs and EBV in a cohort of 94 CRC tissue samples and 13 colorectal normal tissues from the Lebanese population using polymerase chain reaction, immunohistochemistry, and tissue microarray methodologies. We found that high-risk HPVs are present in 64%, while EBV is present in 29% of our CRC samples. Additionally, our data showed that high-risk HPV types (16, 18, 35, 58, 51, 45, 52, 31, and 33) are the most frequent in CRC in the Lebanese cohort, respectively. Our data point out that HPVs and EBV are copresent in 28% of the samples. Thus, this study clearly suggests that high-risk HPVs and EBV are present/copresent in CRCs, where they could play an important role in colorectal carcinogenesis. Nevertheless, further investigations using a larger cohort are needed to elucidate the possible cooperation between these oncoviruses in the development of CRC. 相似文献
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The biological properties of three deletion variants (1704, 1705 and 1706) of herpes simplex virus type-1 (HSV-1) strain 17 syn+, were studied by establishing a base line pathogenicity of nine individual plaques from the parental 17 syn+ elite stock. Restriction enzyme analysis of deoxyribonucleic acid (DNA) from each of the nine plaque stocks and intracranial inoculation into three weeks old BALB/c mice showed no difference in the size of fragments and distribution of the sites or their 50% lethal dose (LD50) values [plaque forming units (pfu)/mouse] as compared to the parental 17 syn+ stock. Inoculation of the variants into three weeks old BALB/c mice showed that 1705 was not different in pathogenicity from the wild type following intracranial and footpad inoculations. On the other hand variants 1704 and 1706, when compared to the wild type virus were less virulent on intracranial inoculation i.e. the difference in LD50 values was approximately one log and two logs respectively and both the variants failed to kill any of the animals following footpad inoculation even at the dose of 1 x 10(7) pfu/mouse. During in vivo replication experiment in the peripheral nervous system of mice, 1704 and 1706 grew very poorly. 相似文献
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Omar M. El-Habbak Abdelrahman M. Abdelalim Nour H. Mohamed Habiba M. Abd-Elaty Mostafa A. Hammouda Yasmeen Y. Mohamed Mohanad A. Taifor Ali W. Mohamed 《计算机、材料和连续体(英文)》2022,70(2):2953-2969
Parkinson’s disease (PD), one of whose symptoms is dysphonia, is a prevalent neurodegenerative disease. The use of outdated diagnosis techniques, which yield inaccurate and unreliable results, continues to represent an obstacle in early-stage detection and diagnosis for clinical professionals in the medical field. To solve this issue, the study proposes using machine learning and deep learning models to analyze processed speech signals of patients’ voice recordings. Datasets of these processed speech signals were obtained and experimented on by random forest and logistic regression classifiers. Results were highly successful, with 90% accuracy produced by the random forest classifier and 81.5% by the logistic regression classifier. Furthermore, a deep neural network was implemented to investigate if such variation in method could add to the findings. It proved to be effective, as the neural network yielded an accuracy of nearly 92%. Such results suggest that it is possible to accurately diagnose early-stage PD through merely testing patients’ voices. This research calls for a revolutionary diagnostic approach in decision support systems, and is the first step in a market-wide implementation of healthcare software dedicated to the aid of clinicians in early diagnosis of PD. 相似文献
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This article addresses the magnetohydrodynamics (MHD) flow of a third grade fluid over an exponentially stretching sheet.Analysis is carried out in the presence of first order chemical reaction.Both cases of constructive and destructive chemical reactions are reported.Convergent solutions of the resulting differential systems are presented in series forms.Characteristics of various sundry parameters on the velocity,concentration,skin friction and local Sherwood number are analyzed and discussed. 相似文献
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Food Science and Biotechnology - Ne-(2-furoylmethyl)-l-lysine (furosine) is well-known indicator of early stage of Maillard reaction in processed food. Yet the toxicological aspects associated with... 相似文献