Observational studies have demonstrated an association between decreased vitamin D level and risk of multiple sclerosis (MS); however, it remains unclear whether this relationship is causal. We ...undertook a Mendelian randomization (MR) study to evaluate whether genetically lowered vitamin D level influences the risk of MS.
We identified single nucleotide polymorphisms (SNPs) associated with 25-hydroxyvitamin D (25OHD) level from SUNLIGHT, the largest (n = 33,996) genome-wide association study to date for vitamin D. Four SNPs were genome-wide significant for 25OHD level (p-values ranging from 6 × 10-10 to 2 × 10-109), and all four SNPs lay in, or near, genes strongly implicated in separate mechanisms influencing 25OHD. We then ascertained their effect on 25OHD level in 2,347 participants from a population-based cohort, the Canadian Multicentre Osteoporosis Study, and tested the extent to which the 25OHD-decreasing alleles explained variation in 25OHD level. We found that the count of 25OHD-decreasing alleles across these four SNPs was strongly associated with lower 25OHD level (n = 2,347, F-test statistic = 49.7, p = 2.4 × 10-12). Next, we conducted an MR study to describe the effect of genetically lowered 25OHD on the odds of MS in the International Multiple Sclerosis Genetics Consortium study, the largest genetic association study to date for MS (including up to 14,498 cases and 24,091 healthy controls). Alleles were weighted by their relative effect on 25OHD level, and sensitivity analyses were performed to test MR assumptions. MR analyses found that each genetically determined one-standard-deviation decrease in log-transformed 25OHD level conferred a 2.0-fold increase in the odds of MS (95% CI: 1.7-2.5; p = 7.7 × 10-12; I2 = 63%, 95% CI: 0%-88%). This result persisted in sensitivity analyses excluding SNPs possibly influenced by population stratification or pleiotropy (odds ratio OR = 1.7, 95% CI: 1.3-2.2; p = 2.3 × 10-5; I2 = 47%, 95% CI: 0%-85%) and including only SNPs involved in 25OHD synthesis or metabolism (ORsynthesis = 2.1, 95% CI: 1.6-2.6, p = 1 × 10-9; ORmetabolism = 1.9, 95% CI: 1.3-2.7, p = 0.002). While these sensitivity analyses decreased the possibility that pleiotropy may have biased the results, residual pleiotropy is difficult to exclude entirely.
A genetically lowered 25OHD level is strongly associated with increased susceptibility to MS. Whether vitamin D sufficiency can delay, or prevent, MS onset merits further investigation in long-term randomized controlled trials.
Molecular imprinting is the process of template-induced formation of specific recognition sites in a polymer. Synthetic receptors prepared using molecular imprinting possess a unique combination of ...properties such as robustness, high affinity, specificity, and low-cost production, which makes them attractive alternatives to natural receptors. Improvements in polymer science and nanotechnology have contributed to enhanced performance of molecularly imprinted polymer (MIP) sensors. Encouragingly, recent years have seen an increase in high-quality publications describing MIP sensors for the determination of biomolecules, drugs of abuse, and explosives, driving toward applications of this technology in medical and forensic diagnostics. This review aims to provide a focused overview of the latest achievements made in MIP-based sensor technology, with emphasis on research toward real-life applications.
Electrochemical and optical sensing based on molecularly imprinted polymers (MIPs) has particular relevance in real-life applications and point-of-care testing in real human samples.
MIPs are a leading technology for sensing molecules where there is no available bioreceptor.
MIP nanoparticles can be used for direct and indirect detection (labeled or label free).
The sensitivity of MIP-based sensors can be enhanced by coupling with nanomaterials such as graphene oxide, carbon nanotubes, or nanoparticles.
The present challenges and perspectives of MIP-based electrochemical and optical sensors include exploring the market niches for MIP sensors and identifying the necessary steps toward commercialization.
•Para grass is a source of low-cost and abundant biomass.•TGA-DSC analyses were performed to understand kinetics of pyrolysis.•Thermodynamics parameters indicate the bioenergy potential of this novel ...biomass.•The bioenergy potential of the biomass is comparable with established bioenergy crops.
The biomass of Urochloa mutica was subjected to thermal degradation analyses to understand its pyrolytic behavior for bioenergy production. Thermal degradation experiments were performed at three different heating rates, 10, 30 and 50°Cmin−1 using simultaneous thermogravimetric-differential scanning calorimetric analyzer, under an inert environment. The kinetic analyses were performed using isoconversional models of Kissenger-Akahira-Sunose (KAS) and Flynn–Wall–Ozawa (FWO). The high heating value was calculated as 15.04MJmol−1. The activation energy (E) values were shown to be ranging from 103 through 233 kJmol−1. Pre-exponential factors (A) indicated the reaction to follow first order kinetics. Gibbs free energy (ΔG) was measured to be ranging from 169 to 173kJmol−1 and 168 to 172kJmol−1, calculated by KAS and FWO methods, respectively. We have shown that Para grass biomass has considerable bioenergy potential comparable to established bioenergy crops such as switchgrass and miscanthus.
In observational studies, type-2 diabetes (T2D) is associated with an increased risk of coronary heart disease (CHD), yet interventional trials have shown no clear effect of glucose-lowering on CHD. ...Confounding may have therefore influenced these observational estimates. Here we use Mendelian randomization to obtain unconfounded estimates of the influence of T2D and fasting glucose (FG) on CHD risk. Using multiple genetic variants associated with T2D and FG, we find that risk of T2D increases CHD risk (odds ratio (OR)=1.11 (1.05-1.17), per unit increase in odds of T2D, P=8.8 × 10(-5); using data from 34,840/114,981 T2D cases/controls and 63,746/130,681 CHD cases/controls). FG in non-diabetic individuals tends to increase CHD risk (OR=1.15 (1.00-1.32), per mmol·per l, P=0.05; 133,010 non-diabetic individuals and 63,746/130,681 CHD cases/controls). These findings provide evidence supporting a causal relationship between T2D and CHD and suggest that long-term trials may be required to discern the effects of T2D therapies on CHD risk.
Laser-induced breakdown spectroscopy (LIBS) is a remarkable elemental detection and quantification technique used in various fields, including science, medicine, engineering, and industries. This ...review focuses on the recent progress and challenges in applying LIBS for geotechnical engineering applications. The paper also discusses the widely employed calibration-free LIBS methods such as chemometrics, artificial neural networks (ANN), and support vector machine (SVM) for quantifying constituent elements. The various applications of LIBS in geosciences, such as in mineralogy, soil studies, rocks investigations, and fluid analysis, have also been presented. Despite the robustness of LIBS in soil studies, it is hitherto challenging to investigate some soil physical parameters. In general, chemical applications such as contamination detection and nutrients are based on detecting certain elements or ions. On the other hand, physical and mechanical applications such as soil texture and soil humification degree may require the usage of a correlation between the chemical elements and the desired parameters. This work, therefore, summarizes how LIBS works with different materials and its current uses in determining the physical or mechanical properties of soils and presents the possibilities of this technology in the field of Geotechnical Engineering.
In the present work, effect of inclusion of silica fume on the performance of natural pozzolan-based cement concrete was investigated. Natural pozzolan, obtained from volcanic rocks, was used as the ...main supplementary cementitious material to partially replace the Portland cement. Silica fume was admixed at an optimum dosage, optimally selected based on the performance of several trial mixtures, in an attempt to improve the performance of the natural pozzolan-based cement concrete. Compressive strength, drying shrinkage, water penetration depth, coefficient of chloride diffusion, carbonation depth, reinforcement corrosion, loss of strength due to exposure to sulfate and salt weathering were measured to evaluate the performance of the concrete mixtures. Inclusion of silica fume to the blend of natural pozzolan and Portland cement significantly improved the performance of concrete. Reduction in the early age compressive strength of natural pozzolan-based cement concrete was compensated for by the addition of silica fume. Inclusion of silica fume to the natural pozzolan-based concrete significantly improved the durability characteristics without significant increase in the shrinkage. Though the addition of silica fume increased the carbonation depth, the increased carbonation depth was much less than the cover thickness normally provided over reinforcing steel, ruling out the possibility of reinforcement corrosion.
•Effects carbonation pressure and duration on effectiveness of accelerated carbonation curing (ACC) of concrete studied.•ACC of concrete at a pressure of 60psi over a period of 10h found to be most ...effective.•Duration of ACC had major effect, increase in pressure from 10 to 60psi had no significant effect.
Accelerated carbonation curing (ACC) is a new technique for curing of concrete that entails sequestering carbon dioxide (CO2) gas into freshly cast concrete, resulting in the improvement of physico-mechanical properties and durability characteristics of concrete. This paper presents the results of an experimental study conducted to evaluate the effects of carbonation pressure and duration on the CO2 uptake and evolution of strength of a concrete mixture. Concrete specimens were cured under six ACC pressures varying from 10 to 60psi, applied for a duration of 1–10h in a closed chamber. The effectiveness of varying ACC pressure and duration on the properties of concrete was assessed by measuring compressive strength gain, CO2 uptake, morphology and mineralogy of concrete. It was noted that ACC at 60psi (414kPa) for 10h resulted in the maximum strength gain and CO2 uptake, leading to a post-ACC compressive strength of more than 200% of the pre-ACC strength, and a CO2 uptake of about 11% by mass of cement. Finally, the analysis of variance of the experimental data indicated that the duration of ACC controls the concrete properties more than the pressure used for ACC.
•A new geometry of cavities in concrete blocks was achieved using FEM.•The new developed block reduced the thermal conductivity by about 40%.•Three different insulation (lightweight) materials were ...used to cast new blocks.•The thermal conductivity of these three new blocks was further reduced.
The aim of this research was to reduce the demand for air conditioning in buildings by minimizing the heat flow from outdoor environment to the interior of building envelopes (walls and roofs). Hence, a finite element model (FEM) was developed to find out the optimum geometry of cavities and their layout in masonry concrete blocks in order to reduce the thermal flow of heat and the results were compared with that of hollow blocks available in the market in terms of thermal insulation. Results of the simulation were promising and indicated that the new “optimum” designed geometry of hollow blocks was much better than the hollow blocks available in the market. Thereafter, some insulation materials were utilized in the concrete mixtures to produce hollow masonry concrete blocks to reduce the thermal conductivity through wall elements. Experimentally, the results of the new block with optimum geometry without the insulation materials showed improved thermal insulation by as much as 71% compared to other designs of hollow blocks including those available in the market. The thermal resistance of concrete and masonry blocks with the insulation materials (perlite, rubber and polyethylene) was enticing and significant. The newly developed optimum design of masonry concrete block with and without the insulation materials satisfied the ASTM C129 requirements for non-load bearing walls in terms of strength and absorption and was considered as medium weight (without insulation material) and as lightweight (with insulation materials) masonry hollow blocks. Results of this comprehensive investigation also indicated that the thermal conductivity could be reduced by up to 40% compared to that of the conventional blocks available in the market. Therefore, it is recommended that these optimum designed blocks be utilized by the construction industry in order to reduce the amount of energy used for the air conditioning as well as the carbon footprrint.
Summary
A paucity of local information concerning the chemical profiles and biological activities of extracts obtained from less‐studied P. granatum peel of Jordanian origin was considered in this ...study for the first time. Fractionation of the crude ethanol extracts was performed because of their higher phenolic and flavonoid contents compared to the water and acetone extracts. The chemical compositions of the respective samples, that is, extracts/fractions were identified by LC–MS/MS, and the elemental content of the raw materials was also analysed using atomic absorption spectrometry. Antioxidant activities of extracts and fractions were evaluated against DPPH and ABTS radical scavenging assays, and the antibacterial activities were investigated by disc diffusion method and MIC (Minimum Inhibitory Concentration). The LC–MS/MS results correlated strongly with the total phenolic and flavonoid contents, where ethanol displayed higher efficacy for extracting bioactive ingredients. Overall, a total of 19 phenolics were detected in the ethanolic peel extract of P. granatum. All of the analysed extracts showed strong antioxidant activities. Fractionation of ethanolic extracts resulted in fractions with almost similar chemical LC–MS/MS profiles, but the relative proportion of constituents was different. All fractions showed lower intensities of antioxidant capacities than crude extracts, highlighting the superiority of some components, either individually or combined, as well as their relative proportion on the biological activity of each fraction. The results of the present study emphasise the need to further explore the effect of putative interactions among plant bioactive ingredients and focus on possible interactions with drugs along with foods.
Phytochemical activities and yields (inset) of P. granatum rind crude extracts and fractions. The results of phenols and tannin were expressed as mg GAE/g dry extract, and the flavonoid content was expressed as mg QE/g dry extract. Averages and standard deviations are shown for triplicate measurements (n = 3).
•Effective treatment methods to improve the properties of crumb rubber were investigated.•Surface texture changes on the crumb rubber surface due to treatment methods were studied.•Treatment methods ...effect on the durability characteristics of crumb rubber concrete was evaluated.•Statistical analysis of factors affect acid resistance of the developed CRC was carried out.
The durability of concrete incorporating crumb rubber (CR) is adversely affected due to the incompatibility of the CR particles with other ingredients of conventional concrete. Consequently, efforts have been made to improve the durability of concrete by treating the CR. In the present work, the effect of treating CR with NaOH, KMnO4, and cement on the durability of concrete was evaluated. Concrete specimens were prepared with 2, 8, 16, 24, and 40% CR (by weight), partially replacing the sand used as fine aggregate. The durability of crumb rubber concrete (CRC) was evaluated by measuring its water absorption, acid resistance, electrical resistivity, and chloride permeability. The water absorption of CRC decreased due to the use of treated CR. This trend was particularly noted in concrete with high quantities of CR. The acid resistance of concrete with up to 8% NaOH-treated CRC was better than that of untreated-CRC. Although the weight loss was lowest in the KMnO4-treated CRC, the strength loss in this type of concrete was more than that of NaOH- and cement-treated CRC. The cement-treated CRC exhibited the best performance against acid attack even with 40% CR replacing the fine aggregate. A remarkable increase in the electrical resistivity and chloride permeability of CRC was noted due to the crucial changes in the pore structure of concrete containing treated-CR. The improvement in the durability of CRC encourages the use of CR so as to help conserve sand as a scarce commodity in many parts of the world. Moreover, the use of CR in concrete contributes to the circular economy of the world due to the utilization of a waste material, namely scrapped automobile tires.
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