606 research outputs found

    A Multi-Omics Epidemiologic Study of Alzheimer’s disease

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    Alzheimer’s disease (AD) is a devastating neurodegenerative disease that accounts for more than 70% of worldwide dementia cases. The rising AD prevalence in aging populations is posing a substantial economic and health challenge. Unfolding the events leading to the development of AD may guide drug and preventive treatment research. Recent advances in multi-omics technology enable us to disentangle the molecular mechanism underlying AD pathophysiology. I have used multi-omics layers to enhance further our understanding of the molecular pathways underlying AD risk and pathophysiology. In this thesis, I identified biological pathways that may contribute to early AD pathology. I also evaluated the role of proteins and metabolites in the circulation and their interaction with AD risk genes. I found elevated levels of the HAGH and CDH6 proteins in blood in pre-dementia cases in the Rotterdam Study, and findings were replicated in an independent cohort. Findings from this thesis also underscore the role of signaling lipids in the pathophysiology of AD. Finally, this thesis provides new insight into the determinants of the gut-liver-brain axis in AD

    Recent Advances in Nanoparticles Enhanced Oil Recovery: Rheology, Interfacial Tension, Oil Recovery, and Wettability Alteration

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    Chemically enhanced oil recovery methods are utilized to increase the oil recovery by improving the mobility ratio, altering the wettability, and/or lowering the interfacial tension between water and oil. Surfactants and polymers have been used for this purpose for the last few decades. Recently, nanoparticles have attracted the attention due to their unique properties. A large number of nanoparticles have been investigated for enhanced oil recovery applications either alone or in combination with surfactants and/or polymers. This review discusses the various types of nanoparticles that have been utilized in enhanced oil recovery. The review highlights the impact of nanoparticles on wettability alteration, interfacial tension, and rheology. The review also covers the factors affecting the oil recovery using nanoparticles and current challenges in field implementation

    Early sowing reduces cotton leaf curl virus occurrence and improves cotton productivity

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    Cotton productivity is severely hampering by various diseases and insect pests especially cotton leaf curl virus (CLCV) worldwide. Losses caused by CLCV are far more than any other factor affecting cotton productivity. Growing of early and resistant genotypes is of vital significance in alleviating the adversities of these pests in crop plants. The current field trial was conducted at Central Cotton Research Institute (CCRI) Multan, Pakistan, to investigate the role of varying sowing dates in managing the CLCV infestation on different elite cotton genotypes. The crop was sown on five different dates i.e. D1= 15th April, D2 = 1st May, D3 = 15th May, D4 = 1st June and D5 = 15th June and three different elite cotton genotypes, i.e. V1= CIM-612, V2 = CIM-591 and V3 = CIM-573 to optimize a suitable sowing date and to screen out high productive and tolerant genotype against the CLCV. Seeds were drilled manually on finely crafted seedbed by using single row hand drill keeping seeding density of 20 kg ha-1 and inter row spacing of 75cm. CLCV severely hampered the crop performance by delayed planting of cotton from 15th April; while increased the chances of disease incidence. It is concluded that early sowing of all tested genotypes especially CIM-592 reduces the problem of CLCV and enhanced cotton productivity

    Evaluation of synchronization protocols and methods of early pregnancy diagnosis in dairy cattle

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    The studies aimed to evaluate the pregnancy rate (PR) for timed artificial insemination (TAI) after G7G-Ovsynch, modified G7G-Ovsynch (MG7G-Ovsynch) and Ovsynch protocols and to assess the accuracy of using pregnancy-associated glycoproteins (PAGs) and plasma progesterone (P4) in pregnancy diagnosis compared with ultrasonography (US). In study 1, Holstein cows (n = 37) were bred by TAI following the G7G-Ovsynch protocol (n = 19) or MG7G-Ovsynch (n = 18). Pregnancy was evaluated by US at days 31, 59, and 87 after breeding. The PR was not different for the G7G-Ovsynch and MG7G-Ovsynch. Blood and milk samples were collected on day 3 after insemination and then weekly through day 59 post TAI in cows diagnosed as not pregnant on day 31 and through day 87 in pregnant cows. PAGs were measured using ELISA and P4 by radioimmunoassay (RIA). In the second study, Holstein cows (n = 212) were bred by TAI following G7G-Ovsynch protocol (n = 110) or standard Ovsynch (n = 102). Cows were subjected to pregnancy diagnosis on days 30, 60, and 90. A subset (n = 15 in each group) was subjected to blood and milk samples on days 30, 45, 60, 75, and 90 to measure PAGs and P4. In study 2, PR was not significantly different between synchronization protocols on days 30, 60, and 90. Pregnancy loss averaged 15% between day 30 and day 90. The use of PAGs and P4 proved equally effective in diagnosis of pregnancy. Thus, G7G-Ovsynch was deemed the protocol of choice in postpartum cows, and PAGs assayed in milk or plasma could be used to diagnose pregnancy

    Energy transition for meeting ecological goals: Do economic stability, technology, and government stability matter?

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    Unquestionably, energy transition, which entails increasing renewables in the energy mix, is among the most reliable strategies to discontinue the utilization of fossil fuels and achieve Sustainable Development Goals (SDGs). In this context, technological advancement can not only stimulate green energy supply but also promote resource efficiency for realizing ecological goals. Also, persistent long-term energy policies and uninterrupted investments are needed to progress on SDGs for climate control and sustainable development. Hence, factors such as economic and government stability are pertinent to implementing and governing energy strategies. Against this background, this study assesses the potential of energy transition in meeting ecological goals by taking into account the roles of economic stability, technology, and government stability in BRICS from 1992 to 2018. Using the second-generation Westerlund cointegration test, the study found a long-run association among variables. The findings from the Continuously Updated Fully Modified (CuP-FM) test disclosed that energy transition is effective in limiting the ecological footprint (EF) in BRICS. Alongside this, economic stability and technology reduce ecological degradation. In addition, government stability stimulates environmental sustainability, while population density decreases environmental sustainability. Finally, the implications of these conclusions for meeting SDGs are discussed and policy directions are provided. Copyright © 2022 Tang, Shahzad, Ahmed, Ahmad and Abbas.Guangdong University of Petrochemical Technology, GDUPT: 2020rc059, 702-72100003004, 702/5210012The correspondence author is supported by the Fundamental Research Start-up Funds from Guangdong University of Petrochemical Technology (Project No. 702-72100003004 and 702/5210012) (Grant No. 2020rc059)

    Exergoeconomic optimization of a shell-and-tube heat exchanger

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    The paper presents an economic optimization of a STHX with two commonly adopted (i.e., Kern and Bell-Delaware) and one rarely explored (i.e., Wills-Johnston) methods. A detailed numerical code concerning thermal, hydraulic, exergy, and economic analysis of STHX is developed for all three methods. Normalized sensitivity analysis, parametric study, and Genetic Algorithm are used to ascertain the most influential parameters and optimize the total cost. It is observed that the calculations made using the Wills-Johnston method were reasonably close to the Bell-Delaware method. While the Kern method showed a significant deviation in the shell side calculations because of the several assumptions in this method. The parametric analysis showed that increasing the mass flow rate and the number of baffles increased the operating cost because of an exponential increase in the pressure drops. Finally, the optimization reduced the heat transfer area by ~26.4%, capital cost by ~20%, operational cost by ~50%, total cost by ~22%, and the stream cost by ~21%

    Immunity and amyloid beta, total tau and neurofilament light chain: Findings from a community-based cohort study

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    Introduction: We investigated how components of immunity relate to biomarkers of Alzheimer's disease (AD) in plasma and explored the influence of AD genetic risk factors in the population-based Rotterdam Study. Methods: In 7397 persons, we calculated the granulocyte-to-lymphocyte ratio (GLR), platelet-to-lymphocyte ratio (PLR), and systemic immune-inflammation index (SII). In 3615 of these persons, plasma amyloid-beta (Aβ)42 and Aβ40 were measured. Next, we constructed an overall genetic risk score (GRS) based on genome-wide significant variants, both including and excluding APOE ε4. Results: All innate immunity phenotypes were related to higher Aβ, most strongly with a doubling in GLR leading to a 1.9% higher Aβ42 (95% confidence interval [95% CI] 0.4 to 3.3%) and 3.2% higher Aβ40 (95% CI 2.0 to 4.3%). Higher AD GRS including APOE ε4 was associated with higher immunity markers. Discussion: Higher levels of immunity markers were associated with higher Aβ in plasma. Participants with a higher genetic predisposition to AD had higher immunity markers, where these effects were mainly driven by APOE ε4

    Analyses of structural and electrical properties of aluminium doped ZnO-NPs by experimental and mathematical approaches

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    Pure and aluminium doped ZnO-NPs were played the central role in every field of life due to extraordi-nary physical, chemical and electrical properties. The main objective of the present research was used to enhance the electrical conductivity and reduce the electrical resistivity of aluminium doped zinc oxide-NPs. Synthesis of pure and aluminium doped zinc oxide-NPs (Zn1-xAlxO) at x = 0, 2.5, 5, 7.5 and 10 wt% was carried out by co-precipitation method. The XRD results depicted that hexagonal wurtzite crystal structure and crystallite size in the range of 13-25 nm were calculated by using Debye-Scherrer's equa-tion. Likewise, the non-uniform, irregular and pore like surface morphology of the prepared NPs was evi-dent from SEM micrographs. Various functional groups (CH, CO, OH and ZnO) attached to the surface of aluminium doped zinc oxide-NPs were identified by FTIR analysis. The UV-VIS spectra also depicted a shift towards the blue region of the visible spectrum. In terms of electrical properties with the help of experimental and mathematical analyses of aluminum doped zinc oxide-NPs exhibited higher conductiv-ity (1.34 x 10(-6) to 1.43 x 10(-3) S/cm) and lower resistivity (5.46 x 10(5) to 6.99 x 10(2) Omega-cm). The present results suggest that the aluminum doped zinc oxide-NPs have been improved the structural and electrical properties which make it a good candidate for optoelectronic devices. (c) 2021 The Authors. Published by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).</p

    Exergoeconomic and Normalized Sensitivity Analysis of Plate Heat Exchangers: A Theoretical Framework with Application

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    Heat exchangers are the mainstay of thermal systems and have been extensively used in desalination systems, heating, cooling units, power plants, and energy recovery systems. This chapter demonstrates a robust theoretical framework for heat exchangers investigation based on two advanced tools, i.e., exergoeconomic analysis and Normalized Sensitivity Analysis. The former is applied as a mutual application of economic and thermodynamic analyses, which is much more impactful than the conventional thermodynamic and economic analyses. This is because it allows the investigation of combinatory effects of thermodynamic and fiscal parameters which are not achieved with the conventional methods. Similarly, the Normalized Sensitivity Analysis allows a one-on-one comparison of the sensitivity of output parameters to the input parameters with entirely different magnitudes on a common platform. This rationale comparison is obtained by normalizing the sensitivity coefficients by their nominal values, which is not possible with the conventional sensitivity analyses. An experimentally validated example of a plate heat exchanger is used to demonstrate the application of the proposed framework from a desalination system

    Optimizing the Energy Recovery Section in Thermal Desalination Systems for Improved Thermodynamic, Economic, and Environmental Performance

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    Integration of energy recovery section with thermal desalination systems improves their performance from thermodynamics, economics, and environmental viewpoints. This is because it significantly reduces input energy, heat transfer area, and capital cost requirements. Above all, the system outlet streams can achieve thermal equilibrium with the environment by supplying heat for useful preheating purposes thus reducing the environmental impacts. The plate heat exchangers are generally employed for this purpose as preheaters. The current paper presents a comprehensive investigation and optimization of these heat exchangers for thermal desalination systems applications. An experimentally validated numerical model employing Normalized Sensitivity Analysis and Genetic Algorithm based cost optimization is developed to investigate their performance at assorted operating conditions. The analysis showed that the heat transfer coefficient, pressure drop, and outlet water cost were improved by an increase in feed flow rate. However, with an increased flow rate, the comprehensive output parameter (h/ΔP) decreased due to the high degree increase in pressure drop. Moreover, an increase in the chevron angle reduced the heat transfer coefficient, pressure drop, and water cost. Finally, the optimization lowered the heat transfer area by ~79.5%, capital investment by ~62%, and the outlet cost of the cold stream by ~15.7%. The operational cost is increased due to the increased pressure drop but the overall impact is beneficial as Ctotal of equipment is reduced by ~52.7%
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