Effect of Carbon Nanotubes on Chloride Diffusion, Strength, and Microstructure of Ultra-High Performance Concrete.

This study delved into the integration of carbon nanotubes (CNTs) in Ultra-High Performance Concrete (UHPC), exploring aspects such as mechanical properties, microstructure analysis, accelerated chloride penetration, and life service prediction. A dispersed CNT solution (0.025 to 0.075 wt%) was employed, along with a superplasticizer, to ensure high flowability in the UHPC slurry. In addition, the combination of high-strength functional artificial lightweight aggregate (ALA) and micro hollow spheres (MHS) was utilized as a replacement for fine aggregate to not only reduce the weight of the concrete but also to increase its mechanical performance. Experimental findings unveiled that an increased concentration of CNT in CNT1 (0.025%) and CNT2 (0.05%) blends led to a marginal improvement in compressive strength compared to the control mix. Conversely, the CNT3 (0.075%) mixture exhibited a reduction in compressive strength with a rising CNT content as an admixture. SEM analysis depicted that the heightened concentration of CNTs as an admixture induced the formation of nanoscale bridges within the concrete matrix. Ponding test results indicated that, for all samples, the effective chloride transport coefficient remained below the standard limitation of 1.00 × 10-12 m2/s, signifying acceptable performance in the ponding test for all samples. The life service prediction outcomes affirmed that, across various environmental scenarios, CNT1 and CNT2 mixtures consistently demonstrated superior performance compared to all other mixtures.

Blast resistance of RC tubular structure under internal ANFO explosion.

The degree of structural damage is significantly more severe when a blast occurs inside than outside of a structure. However, existing designs for RC structures such as reinforced concrete containment vessels (RCCV) do not include design features to protect the structure for internal blast. Therefore, the internal blast resistance capacity of RC structures is evaluated by performing internal blast tests on RC tubular structures. The main objective of the study was to observe and document the basic structural behavior data obtained from internal detonation tests. ANFO explosive charge weights of 15.88, 20.41, 22.68 and 24.95 kg were selected for a charge detonating at a cross section center of the mid-span of the specimen, giving a standoff distance to the inner wall surface of 1000 mm. The data acquisitions include blast pressure, deflection, strain, and crack pattern. When the explosive charge weight increased from 15.88 to 24.95 kg, the peak incident pressure and time duration increased from 0.1718 to 0.3394 MPa and from 5.856 to 5.981 ms, respectively. Then, the test data were used to predict the internal charge weight required to fail a real scale RCCV using simple assumptions and the test data. The results of the study are discussed in detail in the paper.

Observing Cryptocurrencies through Robust Anomaly Scores.

The cryptocurrency market is understood as being more volatile than traditional asset classes. Therefore, modeling the volatility of cryptocurrencies is important for making investment decisions. However, large swings in the market might be normal for cryptocurrencies due to their inherent volatility. Deviations, along with correlations of asset returns, must be considered for measuring the degree of market anomaly. This paper demonstrates the use of robust Mahalanobis distances based on shrinkage estimators and minimum covariance determinant for observing anomaly scores of cryptocurrencies. Our analysis shows that anomaly scores are a critical complement to volatility measures for understanding the cryptocurrency market. The use of anomaly scores is further demonstrated through portfolio optimization and scenario analysis.

Calculation of Cement Composition Using a New Model Compared to the Bogue Model.

The major cement composition ratios of alite, belite, aluminate, and ferrite have been calculated with the Bogue models until now. However, a recent comprehensive analysis based on various experimental data has revealed that the chemical composition of alite, belite, aluminate, and ferrite implemented by the Bogue models are slightly different than the experimental data, where small amounts of Al2O3 and Fe2O3 existing in alite and belite can change the prediction of cement composition. Since the amounts of cement compound are very important factors in determining the properties of concrete, improvement in the calculation would give more precise prediction for application usages such as climate change adaptable cement and high durable concrete manufacturing. For this purpose, 20 new models are proposed by modifying chemical compositions of the cement compounds and verified with the 50 experimental data sets. From the verification, the most accurate models are identified. The calculation using new models exhibit an accuracy improvement of approximately 5% compared to the Bogue models. Their applicable range is also presented. The study results are discussed in detail in the paper.

Enhancement of Lactobionic Acid Productivity by Homologous Expression of Quinoprotein Glucose Dehydrogenase in Pseudomonas taetrolens.

This is the first study on improving lactobionic acid (LBA) production capacity in Pseudomonas taetrolens by genetic engineering. First, quinoprotein glucose dehydrogenase (GDH) was identified as the lactose-oxidizing enzyme of P. taetrolens. Of the two types of GDH genes in P. taetrolens, membrane-bound (GDH1) and soluble (GDH2), only GDH1 showed lactose-oxidizing activity. Next, the genetic tool system for P. taetrolens was developed based on the pDSK519 plasmid for the first time, and GDH1 gene was homologously expressed in P. taetrolens. Recombinant expression of the GDH1 gene enhanced intracellular lactose-oxidizing activity and LBA production of P. taetrolens in flask culture. In batch fermentation of the recombinant P. taetrolens using a 5 L bioreactor, the LBA productivity of the recombinant P. taetrolens was approximately 17% higher (8.70 g/(L h)) than that of the wild type (7.41 g/(L h)). The LBA productivity in this study is the highest ever reported using bacteria as production strains for LBA.

Anti-obesity effects of enzyme-treated celery extract in mice fed with high-fat diet.

The present study demonstrated the anti-obesity effects of enzyme-treated celery extract (ECE) in mice on high-fat diet (HFD). In vitro studies showed that ECE has anti-adipogenic properties by inhibiting lipid accumulations in adipose cells. In vivo studies indicated that the administration of ECE markedly prevented HFD-induced body weight gain, food efficiency ratio, and epididymal fat and liver weights. ECE reduced lipid parameters, cardiac risk factor, and atherogenic index in obese mice. ECE prevented a diabetes state by improving adipokines levels, reducing glucose levels, and preventing insulin resistance. Moreover, ECE prevented HFD-induced liver damage by preventing hepatic steatosis and upregulation of liver antioxidant enzymes. The mechanism of ECE was partially investigated to involve the activation of 5' adenosine monophosphate-activated protein kinase and hence the downregulation of CCAAT/enhancer binding protein α and peroxisome proliferator-activated receptor γ by ECE. Our results suggest that ECE could be used as functional food materials for the prevention of obesity. PRACTICAL APPLICATIONS: Apium graveolens is a popular plant with nutritive and medicinal benefits. It contains bioactive compounds such as apiin, apigenin, and luteolin. However, these compounds are rendered insoluble due to their interaction with polysaccharides in the cell wall thus making them less bioavailable. Hydrolyzing them could increase the yield of bioactive compounds in celery. This pilot study demonstrates that pectinase-treated celery extract has anti-obesity effects. The results of this research demonstrate the use of enzymes in improving the biological activities of plant extracts and suggest the use of enzyme-assisted extraction techniques in the industrial production of health functional food from celery.

Evaluation of the Mechanical Properties of a 3D-Printed Mortar.

The mechanical properties of 3D-printed mortars are determined in terms of their compressive and direct tensile bond strengths. To determine such properties using existing methods, a preliminary experiment was conducted. The compressive strength of the printed mortar was compared to mold-casted specimens and it was found that the compressive strength decreased by ~30%. Among the fabrication variables, an increase in nozzle height negatively influenced the direct tensile bond strength. For the same conditions and age, the direct tensile strength decreased by as much as 16-29% when the number of layers increased from 2 to 6. When the specimens were fabricated using a specially designed stainless steel frame and core drill, followed by extraction and the application of physical impact, the 28 days compressive strength of the specimen decreased by ~50%.

Efficient production of poly γ-d-glutamic acid from the bloom-forming green macroalgae, Ulva sp., by Bacillus sp. SJ-10.

Numerous studies on poly γ-d-glutamicacid (γ-PGA) production have investigated terrestrial renewable sources for reducing production costs, but there are no studies using waste marine resources so far. We aimed to develop a cost-effective production method of γ-d-PGA by Bacillus sp. SJ-10 using green macroalgae (Ulva sp.) as a major substrate without hydrolysis pretreatment. The SJ-10 was shown to not only cause immediate tissue degradation of the Ulva membrane but also grew well as a sole substrate. The γ-d-PGA yield was 6.29 ± 0.34 g/L under optimized conditions via the response surface method, and the produced γ-d-PGA had a thermal decomposition temperature of 310°C and molecular weight of 250-1780 kDa. The calculated cost efficiency for the final yield was 32% when compared with complex media. Therefore, the present study provided a strategy for promoting an ecofriendly and cost-effective means to produce γ-d-PGA via a marine renewable resource.

A practical solution to improve the nutritional balance of Korean dine-out menus using linear programming.

OBJECTIVE: We analysed optimal nutrient levels using linear programming (LP) to reveal nutritional shortcomings of Korean dine-out meals and to stress the importance of fruits and dairy products for maintaining a healthy diet. DESIGN: LP models that minimize deviation from recommended nutrient values were formulated to analyse deficiency or excess of nutrients under the best situation. SETTING: Korean dine-out menus and nutritional information were taken from the nutrient composition tables for dine-out menus developed by the Ministry of Food and Drug Safety and the nutrient database from Computerized Analysis Program. Acceptable macronutrient distribution ranges of macronutrients such as carbohydrate, protein and fat, and recommended intake levels for energy, vitamins, minerals and cholesterol, by sex, were based on the Dietary Reference Intake for Koreans aged 30-49 years.ParticipantsOptimization was performed on selecting the optimal Korean meal combination. RESULTS: LP optimization models showed that it is unlikely to satisfy all nutrient recommendations with any combination of dine-out menus. Specifically, meal combinations of Korean dine-out menus had high levels of Na and cholesterol and low levels of vitamins and minerals. Four formulations were considered to compare the effects of controlling Na and including fruit and dairy products. The unbalanced diet was resolved with extra consumption of fruits and dairy products. CONCLUSIONS: The best meal combination in dine-out menus, even though the proportion and pairing of menus may be unrealistic, is not healthy, and thus one should consume fruits and dairy products to maintain a balanced diet.

Immobilization of ß-1,3-1,4-glucanase from Bacillus sp. on porous silica for production of ß-glucooligosaccharides.

(1,3)(1,4)-ß-d-glucan has been determined to have various beneficial effects due to its unique structure. ß-glucooligosaccharides (ß-GOS), which are hydrolysates of barley (1,3)(1,4)-ß-d-glucan, provide a useful prebiotic material for selective growth of probiotic bacteria. In this study, recombinant ß-1,3-1,4-glucanase (Bg1314) from Bacillus sp. SJ-10 (KCCM 90078) was immobilized on porous silica using glutaraldehyde as a crosslinking reagent to achieve efficient production of ß-GOS. We investigated the effects of factors such as the amounts of enzyme and glutaraldehyde, reaction temperature, and pH on catalytic activity. Enzyme activity decreased sharply at high concentrations of glutaraldehyde, likely due to the reaction of glutaraldehyde with lysine residues at the catalytic site of Bg1314, because lysine-substituted Bg1314 retained its activity under the same conditions. Immobilized Bg1314 protein (ImBg1314) was stable over a wide range of pH and could be stored long term at 4 °C. The optimal conditions of ImBg1314 were similar to those of Bg1314. However, the optimal temperature of ImBg1314 differed from that of Bg1314. The products were ß-GOS composed of 3-O-ß-cellobiosyl-d-glucose and 3-O-ß-cellotriosyl-d-glucose. After ImBg1314 was reused for 10 cycles, it retained 42% of its initial catalytic activity. This study showed that the Imbg1314 applied economical production of ß-GOS.

Development of a bio-electrospray system for cell and non-viral gene delivery.

Bio-electrospray technology is a very attractive tool for preparing scaffolds and depositing desired solutions on various targets by electric force. In this study, we focused on the application of a bio-electrospray (BES) technique to spray cells on the target and to simultaneously deliver genetic constructs into the cells, called non-viral gene delivery-based bio-electrospray (NVG-BES). Using this method, we tried to harvest the electric charge produced during electrospray for the cellular internalization of cationic polymer/DNA nanoparticles as well as the delivery of living cells on the desired substrate. Furthermore, we optimized the voltage, culture medium and polymeric cationic charges for high transfection efficiency and cell viability during NVG-BES. As a result, the solutions used during the NVG-BES process played an important role in improving transfection efficiency. We determined that a voltage of 10 kV with PBS as the spraying solution showed high transfection efficiency, probably due to the facilitation of cationic polymer/DNA nanocomplexes in cellular internalization and their subsequent expression. In conclusion, NVG-BES, as a novel method, is expected to deliver genes to cells and simultaneously deliver transfected cells to any substrate or scaffold.

Physicochemical properties, production, and biological functionality of poly-γ-d-glutamic acid with constant molecular weight from halotolerant Bacillus sp. SJ-10.

Poly-γ-glutamic acid (γ-PGA) is an unusual anionic homopolyamide that is biodegradable, edible, and nontoxic. It has a wide variety of industrial applications depending on its combined cations, and molecular weight. In this study, extracellular viscous γ-PGA produced by halotolerant Bacillus sp. SJ-10 isolated from a traditional Korean salted-fermented seafood was purified and characterized. The physicochemical analysis indicated that the γ-PGA produced by Bacillus sp. SJ-10 consists primarily of d-glutamic acid residues combined with sodium cations. When batch fermentation was performed with 8% NaCl for 3 d, Bacillus sp. SJ-10 produced approximately 24.7g/L γ-PGA with a molecular weight of approximately 400 kilodaltons (kDa). Under fermentation conditions with 6% NaCl, the maximum yield was 26.2g/L regardless of the molecular weight. The γ-PGA sodium salt with a molecular weight of 400kDa exhibited antioxidant activity by scavenging 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) radicals and reducing molybdenum, with maximal scavenging activity at 0.5mg/mL and reducing activity at 1mg/mL (20µg ascorbic acid-equivalent), respectively. These results suggest the potential use of γ-PGA in the food, cosmetic, and biomedical industries for its antioxidant qualities. Our results also provide an economical method for controlling the molecular weight of the γ-PGA produced.

Correction: Development of a bio-electrospray system for cell and non-viral gene delivery.

[This corrects the article DOI: 10.1039/C7RA12477E.].

Design Optimization and Structural Performance Evaluation of Plate Girder Bridge Constructed Using a Turn-Over Process.

A recent trend in bridge construction has been the optimization of the cost-to-performance ratio. The most effective way to optimize the cost-to-performance ratio is to maximize the efficiency of the superstructure. Currently, many bridge engineers and designers favor two- or three- girder plate superstructures, due to their cost advantages. However, research on the performance enhancements of the I-type girder in two- or three- girder plate bridges is lacking. One of the most important performance improvement technologies for the I-type girder is the "preflex" method. In the preflex method, the specimen is inverted during the construction process to apply prestressed cambering to the specimen by using self-weight. However, a problem with the preflex construction method is difficulty with inverting the girder/plate system during the concrete curing process. Therefore, a new inverting system called Turn-Over (TO) wheel was proposed. Using TO wheels, wider variations to the I-type girder design can be achieved. Using this TO construction method, various cross sectional designs of girder plate systems can be considered due to its easiness in inverting the girder/plate system. In this study, the location of concrete confinement sections between the steel I-beams and concrete plates was varied in an I-girder cross-sectional design. Design parameters included effective height, flange thickness, flange width, confining concrete section width, etc. From this study, the optimum cross-sectional design of the I-girder/concrete plate system was achieved. Then, a single 20 m TO girder/plate system and two 20 m TO girder bridges were constructed and tested to evaluate their performance. From the test, failure behavior, load carrying capacity, crack pattern, etc., are obtained. The results are discussed in detail in this paper.

Ameliorative effects of Diospyros lotus leaf extract against UVB-induced skin damage in BALB/c mice.

The aim of this study was to investigate the protective effect of Diospyros lotus leaf extract (DLE) on UVB-induced skin damage in mice. UVB irradiation of mice skin incurred significant damage to mice skin; increased thiobarbituric acid-reactive substance level; decreased superoxide dismutase; and glutathione levels in mice skin tissues. More so, UVB irradiation led to collagen degradation and infiltration of mast cell and neutrophils into mice skin leading to inflammation. However, topical application of DLE significantly reversed these conditions with the result comparable to l-ascorbic acid. Myricitrin, gallic acid, astragalin, myricetin-3-O-glactosside, and myricetin through high-performance liquid chromatography analysis were further determined to be the primary active compounds in DLE. In conclusion, our study showed that DLE has potentials as local therapeutic materials against skin damage by inhibiting oxidative stress and UVB-induced skin damage.

Modification of Rule of Mixtures for Tensile Strength Estimation of Circular GFRP Rebars.

The rule of mixtures (ROM) method is often used to estimate the tensile strength of fiber reinforced polymers (FRPs) reinforcing bars (rebars). Generally, the ROM method predicts the FRP rebars' modulus of elasticity adequately but overestimates their tensile strength. This may result from defects occurred during manufacture that prevent the used materials from exhibiting a sound performance and the shear-lag phenomenon by transmission of external forces through the surface of the rebar having a circular cross section. Due to the latter, there is a difference in fiber breaking points regarding the fibers located on the surface and fibers located at the center, and thus results in differences between the values calculated from the conventional ROM and the experimental result. In this study, for the purpose of resolving the problem, glass FRP (GFRP) rebars were shaped to have a hollow section at the center of their cross sections and were further subject to tensile strength tests. The test results were further placed under regression analysis and a modified ROM within ±5% accuracy compared to the experimental value was proposed for GFRP rebars with 13, 16, and 19 mm diameters.

Children's Healthy Living Program (CHL) Indigenous Workforce Training to Prevent Childhood Obesity in the Underserved U.S. Affiliated Pacific Region.

The U.S. Affiliated Pacific Region (USAPR) is an underserved region with high rates of obesity-related, non-communicable diseases and a low proportion of trained obesity prevention professionals, especially indigenous professionals. The Children's Healthy Living Training Program was developed to enhance the USAPR's capacity to address childhood obesity prevention.

Material Performance and Animal Clinical Studies on Performance-Optimized Hwangtoh Mixed Mortar and Concrete to Evaluate Their Mechanical Properties and Health Benefits.

In this study, the amount of cement used in a concrete mix is minimized to reduce the toxic effects on users by adjusting the concrete mixture contents. The reduction of cement is achieved by using various admixtures (ground granulated blast-furnace slag, flyash, ordinary Portland cement, and activated Hwangtoh powder). To apply the mix to construction, material property tests such as compressive strength, slump, and pH are performed. Preliminary experimental results showed that the Hwangtoh concrete could be used as a healthy construction material. Also, the health issues and effects of Hwangtoh mortar are quantitatively evaluated through an animal clinical test. Mice are placed in Hwangtoh mortar and cement mortar cages to record their activity. For the test, five cages are made with Hwangtoh and ordinary Portland cement mortar floors, using Hwangtoh powder replacement ratios of 20%, 40%, 60%, and 80% of the normal cement mortar mixing ratio, and two cages are made with Hwangtoh mortar living quarters. The activity parameter measurements included weight, food intake, water intake, residential space selection, breeding activity, and aggression. The study results can be used to evaluate the benefits of using Hwangtoh as a cement replacing admixture for lifestyle, health and sustainability.

Systematic Review of Prevalence of Young Child Overweight and Obesity in the United States-Affiliated Pacific Region Compared With the 48 Contiguous States: The Children's Healthy Living Program.

We estimated overweight and obesity (OWOB) prevalence of children in US-Affiliated Pacific jurisdictions (USAP) of the Children's Healthy Living Program compared with the contiguous United States. We searched peer-reviewed literature and government reports (January 2001-April 2014) for OWOB prevalence of children aged 2 to 8 years in the USAP and found 24 sources. We used 3 articles from National Health and Nutrition Examination Surveys for comparison. Mixed models regressed OWOB prevalence on an age polynomial to compare trends (n = 246 data points). In the USAP, OWOB prevalence estimates increased with age, from 21% at age 2 years to 39% at age 8 years, increasing markedly at age 5 years; the proportion obese increased from 10% at age 2 years to 23% at age 8 years. The highest prevalence was in American Samoa and Guam.

Material and Structural Performance Evaluations of Hwangtoh Admixtures and Recycled PET Fiber-Added Eco-Friendly Concrete for CO2 Emission Reduction.

In order to reduce carbon dioxide (CO2) emissions and produce an eco-friendly construction material, a type of concrete that uses a minimal amount of cement, yet still retains equivalent properties to ordinary cement concrete, has been developed and studied all over the world. Hwangtoh, a type of red clay broadly deposited around the world, has traditionally been considered an eco-friendly construction material, with bonus advantages of having health and cost benefits. Presently, Hwangtoh is not commonly used as a modern construction material due to properties such as low strength and high rates of shrinkage cracking. Recent studies, however, have shown that Hwangtoh can be used as a mineral admixture to improve the strength of concrete. In addition, polyethylene terephthalate (PET) fibers recycled from PET bottle waste can be used to control shrinkage cracks in Hwangtoh concrete. Therefore, in this study, performance verification is conducted on newly developed Hwangtoh concrete mixed with short recycled PET fibers. The results show that Hwangtoh concrete has compressive strength, elastic modulus, and pH properties that are similar to these features in ordinary cement concrete. The properties of carbonation depth and creep strain of Hwangtoh concrete, however, are larger and smaller, respectively, than in ordinary cement concrete. According to flexural tests, reinforced concrete (RC) specimens cast with Hwangtoh admixtures (with and without PET fibers) possess similar or better capacities than ordinary RC specimens. The addition of PET fibers significantly improves the structural ductility of RC specimens under normal environmental conditions. However, the implementations of the concrete in aggressive environment must be carefully considered, since a previous study result indicates degradation of its durability performance in aggressive environments, such as seawater [1]. The results of this study validate the possibility of using eco-friendly Hwangtoh concrete reinforced with recycled PET fibers as a structural material for modern construction.