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Abstract Nanostructured cathode materials based on Mn-doped olivine LiMnxFe1−xPO4 (x = 0, 0.1, 0.2, and 0.3) were successfully synthesized via a hydrothermal route. The field-emission scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) analyzed results indicated that the synthesized LiMnxFe1−xPO4 (x = 0, 0.1, 0.2, and 0.3) samples possessed a sphere-like nanostructure and a relatively homogeneous size distribution in the range of 100–200 nm. Electrochemical experiments and analysis showed that the Mn doping increased the redox potential and boosted the capacity. While the undoped olivine (LiFePO4) had a capacity of 169 mAh g−1 with a slight reduction (10%) in the initial capacity after 50 cycles (150 mAh g−1), the Mn-doped olivine samples (LiMnxFe1−xPO4) demonstrated reliable cycling tests with negligible capacity loss, reaching 151, 147, and 157 mAh g−1 for x = 0.1, 0.2, and 0.3, respectively. The results from electrochemical impedance spectroscopy (EIS) accompanied by the galvanostatic intermittent titration technique (GITT) have resulted that the Mn substitution for Fe promoted the charge transfer process and hence the rapid Li transport. These findings indicate that the LiMnxFe1−xPO4 nanostructures are promising cathode materials for lithium ion battery applications.

A colorimetric chemosensor for hydrogen peroxide (H2O2) and biosensor for cholesterol is developed in this work following a ‘label-free and reagentless’ concept. In this strategy, silver nanoparticles (AgNPs) are used as a bifunctional probe, namely, a chemical capture probe for H2O2 recognition and a signal probe for displaying detection results. The working principle of these colorimetric sensors is based on the redox reaction between AgNPs and H2O2. This reaction converts AgNPs into Ag+ ions, which can induce a visible color change from yellow to pinkish or colorless depending on the amount of H2O2. Therefore, H2O2 concentration can be measured. The developed colorimetric H2O2 chemosensor exhibits a highly selective and sensitive property towards H2O2 with a limit of detection (LOD) of 3.5 μM. Subsequently, a colorimetric biosensor is developed for cholesterol detection by combining AgNPs and cholesterol oxidase (ChOx) enzyme. Here, ChOx oxidizes cholesterol into cholest-4-en-3-one and H2O2. Then, the detected as-generated H2O2 concentration reflects the cholesterol level in the sample. This cholesterol biosensor exhibits high selectivity and sensitivity for cholesterol detection with a LOD of 40 μM. The developed sensor is successfully applied to the detection of cholesterol levels in serum samples. Our results show that the AgNP–based colorimetric method is cost-effective, sensitive and selective. It has potential applications in H2O2 and cholesterol detection and in clinical and medical diagnoses.

In this study, we present a novel approach to prepare of a colorimetric chemical sensor for H2O2 and a glucose biosensor basing on the use of peroxidase-like activity of silver nanoparticles decorated on reduced graphene oxide sheets (AgNPs@rGO) nanocomposite. Herein, AgNPs@rGO nanocomposite was synthesized by a one-step hydrothermal reducing method and its physico-chemical properties were characterized by X-ray diffraction (XRD), Transmission Electron Microscopy (TEM), Ultraviolet–visible spectroscopy (UV–Vis), Fourier-Transform Infrared spectroscopy (FT-IR) and Energy Dispersive X-ray spectroscopy (EDX). Obtained evaluation results shown that the synthesized AgNPs/rGO nanocomposite has performed an efficient peroxidase-like activity for the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMBred) by H2O2, leading to the oxidized form (TMBox) which presents a typical blue color (maximum of absorbance at λmax = 655 nm). A colorimetric assay for H2O2 detection was designed and fabricated with a limit of detection of 20 μM. Moreover, we have used of AgNPs/rGO nanocomposite combining with glucose oxidase (GOx) to develop of a colorimetric glucose biosensor with a low limit of detection of 40 μM and a linear dynamic range from 125 μM to 1 mM. This glucose test was applied to the detection of glucose in human serum samples.

Owing to the COVID-19 pandemic, huge amounts of disposable face masks have been manufactured and used, and these discarded face masks have to be treated. In this study, we propose a simple approach for reusing the nonwoven polyester fabric (NWPF) from disposable face masks. In this approach, NWPF is utilized as a supporter for coating of a layer of graphene oxide/Fe3O4/chitosan (GFC) to form a GFC/NWPF adsorbent at room temperature via a simple spray coating method that does not require any solvent. The specific properties of GFC, NWPF, and the GFC/NWPF adsorbent were analysed via X-ray diffraction, transmission electron microscopy, ultraviolet–visible spectroscopy, vibrating sample magnetometry, and field-emission scanning electron microscopy. Results showed that the presence of NWPF enhanced the adsorption capacity of GFC towards organic dyes. At high concentrations of the organic dyes, the adsorption efficiency of the GFC/NWPF adsorbent to the dyes reached 100% within 24 h. The adsorption capacity (qmax) of the GFC/NWPF adsorbent to methylene blue, methyl orange, Congo red, and moderacid red was 54.795, 87.489, 88.573, and 29.010 mg g−1, respectively, which were considerably higher than that of bulk GFC (39.308, 82.304, 52.910, and 21.249 mg g−1, respectively).

Abstract Background Little is known about the association of hyperglycemia with the development of ventricular tachycardia (VT) in patients hospitalized with acute myocardial infarction (AMI) which we examined in the present study. The objectives of this community-wide observational study were to examine the relation between elevated serum glucose levels at the time of hospital admission for AMI and occurrence of VT, and time of occurrence of VT, during the patient’s acute hospitalization. Methods We used data from a population-based study of patients hospitalized with AMI at all central Massachusetts medical centers between 2001 and 2011. Hyperglycemia was defined as a serum glucose level ≥ 140 mg/dl at the time of hospital admission. The development of VT was identified from physicians notes and electrocardiographic findings by our trained team of data abstractors. Results The average age of the study population was 70 years, 58.0% were men, and 92.7% were non-Hispanic whites. The mean and median serum glucose levels at the time of hospital admission were 171.4 mg/dl and 143.0, respectively. Hyperglycemia was present in 51.9% of patients at the time of hospital admission; VT occurred in 652 patients (15.8%), and two-thirds of these episodes occurred during the first 48 h after hospital admission (early VT). After multivariable adjustment, patients with hyperglycemia were at increased risk for developing VT (adjusted OR = 1.48, 95% CI = 1.23–1.78). The presence of hyperglycemia was significantly associated with early (multivariable adjusted OR = 1.39, 95% CI = 1.11–1.73) but not with late VT. Similar associations were observed in patients with and without diabetes and in patients with and without ST-segment elevation AMI. Conclusions Efforts should be made to closely monitor and treat patients who develop hyperglycemia, especially early after hospital admission, to reduce their risk of VT.

In this paper, we demonstrate a promising method to fabricate a non-enzymatic stable, highly sensitive and selective hydrogen peroxide sensor based on a chitosan/silver nanoparticles (CS/AgNPs) hybrid. Using this composite, we elaborated both electrochemical and colorimetric sensors for hydrogen peroxide detection. The colorimetric sensor is based on a homogenous reaction which fades the color of CS/AgNPs solutions from red-orange to colorless depending on hydrogen peroxide concentration. For the electrochemical sensor, CS/AgNPs were immobilized on glassy carbon electrodes and hydrogen peroxide was measured using cyclic voltammetry, square wave voltammetry and electrochemical impedance spectroscopy. The response time is less than 10 s and the detection limit is 5 μM. Keywords: Spectrophotometric detection, Electrochemical impedance spectroscopy, Square wave voltammetry, Cyclic voltammetry, Chitosan/silver nanoparticles (CS/AgNPs) hybrid, Hydrogen peroxide

In this paper, Fe3O4/graphene oxide/chitosan (FGC) nanocomposite was synthesized using coprecipitation method for application to removal of nickel ion (Ni(II)) from aqueous solution by adsorption process. To determine residue Ni(II) ions concentration in aqueous solution after adsorption process, we have used UV-Vis spectrophotometric method, which is an effective and exact method for Ni(II) monitoring at low level by using dimethylglyoxime (DMG) as a complex reagent with Ni(II), which has a specific adsorption peak at the wavelength of 550 nm on UV-Vis spectra. A number of factors that influence Ni(II) ions adsorption capacity of FGC nanocomposite such as contact time, adsorption temperature, and adsorbent dosage were investigated. Results showed that the adsorption equilibrium is established after 70 minutes with the adsorbent dosage of 0.01 g.mL−1 at 30°C (the room temperature). The thermodynamic and kinetic parameters of this adsorption including free enthalpy change (∆G0), enthalpy change (∆H0), entropy change (∆S0), and reaction order with respect to Ni(II) ions were also determined. The Ni(II) ions adsorption equilibrium data are fitted well to the Langmuir isotherm and the maximum monolayer capacity (qmax) is 12.24 mg.g−1. Moreover, the FGC adsorbent can be recovered by an external magnet; in addition, it can be regenerated. The reusability of FGC was tested and results showed that 83.08% of removal efficiency was obtained after 3 cycles. The synthesized FGC nanocomposite with many advantages is a promising material for removal of heavy metal ions from aqueous solution to clean up the environment.

Horseradish peroxidase (HRP), a natural enzyme, consists of a FeIII ion, which plays the role as an active center of the enzyme, wherein the binding of H2O2 to the FeIII ion creates an octahedral configuration around FeIII, leading to the decomposition of the –O–O– bond of H2O2. Based on this considering, here, we propose amorphous-carbon-functionalized Fe3O4 nanoparticles (Fe3O4@C) that serve as a peroxidase nanozyme with FeIII and exhibits peroxidase-like catalytic activity. In this work, Fe3O4@C was synthesized via a simple hydrothermal process from a suspension of Fe3O4 nanoparticles and glucose solution. The peroxidase-mimicking activity of Fe3O4@C was demonstrated following the Michaelis–Menten and Lineweaver–Burk equations of the enzymatic model. At optimized conditions, Fe3O4@C showed stronger catalytic activity than HRP, with Michaelis–Menten constants (Km) 0.052 mM and 0.004 mM for the H2O2 substrate and TMB co-substrate, respectively. Using Fe3O4@C as a replacement for HRP, a colorimetric chemical sensor for H2O2 sensing and a colorimetric biosensor for glucose detection were constructed, and they exhibited high selectivity and sensitivity with an LOD of 20 μM for H2O2 and 40 μM for glucose. The applicability of the glucose biosensor was also tested in real samples, including a 5% intravenous glucose solution and human blood serum, revealing high recovery rates. [ABSTRACT FROM AUTHOR]

The severe gummy smile and a skeletal class II profile pose challenges in treatment. This case report outlines an effective alternative for addressing these problems in a patient with skeletal class II division 2, class II molar relationship, retroclination of upper incisors, and lip protrusion. Treatment objectives included normalizing the overjet and overbite, improving the gummy smile, and establishing a satisfactory occlusion. A three-dimensional simulation was performed to consult with the patient, assess possible results, and predict treatment biomechanics. The treatment involved the use of two zygomatic and one inter-radicular temporary anchorage devices, along with botulinum toxin. After the 2-year follow-up, a satisfactory dental occlusion, aesthetic improvement, and adequate function were achieved. This approach offers a viable alternative to orthognathic surgery for adults with skeletal class II malocclusion and a severe gummy smile due to hypermobile lip. [ABSTRACT FROM AUTHOR]

A smile that reveals >4 mm of gum tissue is called a gummy smile (GS), offering negative impacts on people's self-confidence and aesthetic appearance. The treatment for GS should be planned according to underlying causes such as altered passive eruption of teeth, dentoalveolar extrusion, vertical maxillary excess, and short or hyperactive lip muscles. In this case report, a patient with severe GS received orthodontic and gingivoplasty treatment, aided by digital tools such as 3D simulation, smile design, and 3D printed guides. The treatment yielded remarkable and satisfactory results, without the need for extensive surgery. Our findings suggest that gingivoplasty is a minimally invasive, time- and cost-effective alternative to more extensive procedures for correcting severe gum recession. [ABSTRACT FROM AUTHOR]

This report describes the bone reduction guide which was digitally obtained to improve diagnosis, treatment outcome and follow-up. Treatment of gingival smiles due to altered passive eruption should include interdisciplinary planning and smile design to facilitate the prediction of treatment outcome. Crown lengthening surgery can be supported by digital tools to improve surgical planning and follow-up. A 30-year-old female patient was referred to a private dental clinic seeking solutions for her gingival smile. Based on the anatomical crown length, a smile design was created, and the patient was presented with a simulated smile before treatment. In the surgical phase, a full-thickness flap was raised in the upper jaw to achieve the desired outcome. Using cone-beam computed tomography to determine cementoenamel junction for smile design and treatment planning brings many benefits. Patients and clinicians can foresee treatment results. From there, appropriate changes can be made. The bone reduction guide is designed to rest on the bone to help the clinician cut the bone accurately and thoroughly follow the established plan. [ABSTRACT FROM AUTHOR]

During the past millions of years since the beginning of our world, nature has created structures that are resistant to the various effects of the environment. However, these natural structures are quite complicated, so their production and artificial reproducibility with the tools of traditional manufacturing technology is a very difficult task. However, even complex structures can be produced relatively easily with the help of additive manufacturing. Using topological optimization techniques, lattice structure models with excellent mechanical characteristics can be created, which can be easily manufactured by exploiting the advantages of additive manufacturing. Applying natural structures (biomimetic approach) during topological optimization and produce the solution by additive manufacturing, light and high-strength structural alternatives can be created, any further structural analyses can be done. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this paper is to evaluate the global competitiveness of the top ten wooden furniture exporting countries with several approaches and to test the effect of export prices (EXPRs) on the global competition. Design/methodology/approach: Countries' competitiveness levels were measured with revealed comparative advantage (RCA), normalised RCA (NRCA), revealed symmetric comparative advantage (RSCA) and trade balance index. Furthermore, panel regression analysis techniques were used to test the effects of EXPR on RCA, NRCA and RSCA in the wooden furniture industry (WFI). Findings: Although the comparative advantage approaches give different results, the global competitiveness of Poland and Vietnam is at a high level in all approaches. Canada has been the country with the weakest global competitiveness in all approaches. According to the results of the analysis, EXPRs positively affect all the competitive advantage indexes. As a result, the competitiveness of the WFI is affected by the non-price factors instead of the EXPR. Research limitations/implications: The framework allows us to measure and illustrate the export competitiveness of the WFI and permits a global comparison. Similar analyses can be made for different labour-intensive sectors. In addition, analysis can be made to identify non-price factors for the WFI sector. Thus, more specific inferences can be made. Practical implications: This study is useful for policymakers, government officials, the industry associations and the company executives to assess their export competitiveness in the WFI. Thus, they can determine whether to shift scarce resources to this industry or other industries. In addition, this study may affect the price competition policy of the sector representatives in the global market. Originality/value: This study deals with the competitiveness of the WFI with different approaches. And this study determines the importance of price for global competition in this sector. [ABSTRACT FROM AUTHOR]

This work focused on synthesising Ni-doped LiNixFe1−xPO4/C (x = 0, 0.05 and 0.1) cathode materials by hydrothermal method. The crystalline structure and morphology of the synthesised materials were investigated through x-ray diffraction, Raman scattering spectroscopy, thermal gravimetric analysis, and scanning electron microscopy. Their electrochemical performance was analysed by cyclic voltammetry and galvanostatic cycling test. The highest initial capacity of 170.3 mAh/g was achieved for LiNi0.1Fe0.9PO4/C. It also maintained 99.68% of its initial capacity for 120 cycles, with a Li+-ion diffusion coefficient of 1.12 × 10−12 cm2/s compared with that (9.21 × 10−13 cm2/s) of LiNi0.05Fe0.95PO4/C. [ABSTRACT FROM AUTHOR]

Organic dyes are widely existing in the waste of printing and dyeing industry, which cannot be ignored due to their potential threats to human health and the environment. Development a useful and simple technology to prepare high‐performance adsorbent to purify the dyes from the wastewater is always a challenging. In this work, the freeze‐drying graphene (FG) is prepared through freeze‐drying process method. In addition, the structural and chemical characteristics between the FG and graphene were comparatively analyzed. The results show that compare to the reference graphene, the FG is a high‐efficiency adsorbent. The theoretical maximum undertakes of rhodamine B and methyl blue were 358.62 and 547.81 mg g−1. The influence and mechanism of affecting factors were investigated, such as contact time, adsorbent dosage, pH, and temperature, to the adsorption. The results suggested that the adsorption of organic dyes on FG followed a homogeneous monolayer physical adsorption (HMPA) mechanism, and the adsorption rates were related to the number of unoccupied vacancies on the adsorbent surface. The characterization instruments of FTIR, XPS, and SEM‐EDS confirmed that the HMPA contains the formation of hydrogen‐bond and π–π interactions, electrostatic attraction, physical pore filling, and complexing adsorption. Our work, proposes a freeze‐drying graphene that is a promising candidate as high‐performance adsorbent to purify the dyes from the wastewater. [ABSTRACT FROM AUTHOR]

Introduction: The relationship between relative hyperglycemia and ventricular arrhythmia (VA) in critically ill patients admitted to intensive care units (ICU) remains unclear. This study aims to investigate the association between stress hyperglycemia ratio (SHR) and VA in this population. Methods: This retrospective and observational study analyzed data from 4324 critically ill patients admitted to the ICU, obtained from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. The SHR was calculated as the highest blood glucose level during the first 24 h of ICU admission divided by the admission blood glucose level. Based on the optimal cut-off values under the receiver operating characteristic curve, patients were stratified into high SHR (≥ 1.31) and low SHR (< 1.31) group. To investigate the impact of diabetes mellitus (DM) on the outcome, patients were stratified as low SHR/DM; low SHR/non-DM; high SHR/DM, and high SHR/non-DM. Restricted cubic spline (RCS) and logistic regression analysis were performed to analyze the relationship between SHR and VA. Results: A total of 4,324 critically ill patients were included in this retrospective and observational study. The incidence of VA was higher in the high SHR group. Multiple-adjusted RCS revealed a "J-shaped" correlation between SHR and VA morbidity. The logistic regression model demonstrated that high SHR was associated with VA. The high SHR/non-DM group had a higher risk of VA than other groups stratified based on SHR and DM. Subgroup analysis showed that high SHR was associated with an increased risk of VA in patients with coronary artery disease. Conclusion: High SHR is an independent risk factor and has potential as a biomarker of higher VT/VF risk in ICU-admitted patients. [ABSTRACT FROM AUTHOR]

Optical immersion lithography using fluids with refractive indices greater than that of water (1.436) can enable numerical apertures of 1.55 or above for printing sub-45-nmlines. Two second-generation immersion fluid candidates, IF132 and IF169, both have indices above 1.64 and have been optimized to absorb less than 0.1 cm−1at 193.4 nm. These fluids, although meeting the requirements of index and absorption, must also be compatible with current resists and processes to image the required fine line patterns. Results of fluid-resist interactions, with water and high-index fluids on four commercial resists, are shown. Photoacid generator (PAG) leaching measurements reveal much less leaching into both high-index fluids than into water, and in two water-immersion dedicated resists, no leaching is detected with the high-index immersion fluids. Little resist thickness change and swelling is detected by a quartz crystal microbalance (QCM) on contact with the fluids. Resist profile and line height changes due to pre- and postexposure fluid contact varies from one resist to the next, but overall the changes are minimal. Misting defects from high-index fluid-resist contact show lower counts than for water, and imaging on an immersion interference printer produces 36-nmhalf-pitch lines. We find no serious impediments to the use of high-index liquids based on these results. [ABSTRACT FROM AUTHOR]

In this study, a 0.2CoFe2O4/0.8TiO2-5%La nanocomposite was synthesized by a co-precipitation and a hydrothermal method and then was applied as a high activity photocatalyst for degradation of methylene blue under visible light irradiation. The 0.2CoFe2O4/0.8TiO2-5%La material was characterized by X-ray diffraction, Raman spectra, scanning electron microscope/transmission electron microscope and UV-Vis techniques. The photocatalytic activity of the material was initially investigated through the decomposition of methylene blue. The synthetic 0.2 CoFe2O4/0.8 TiO2-5% La showed excellent photocatalytic activity for degradation of methylene blue under visible light irradiation. Methylene blue could be degraded by more than 99.14% after only 50 min. [ABSTRACT FROM AUTHOR]

Objectives: In March 2020, a COVID‐19 outbreak in a major referral hospital in Hanoi, Vietnam led to 7664 patients and staff being sent into lockdown for 2 weeks, and more than 52,200 persons across 49 provinces being quarantined. We assessed SARS‐CoV‐2 transmission patterns during this to‐date largest hospital outbreak in Vietnam using social network analysis (SNA). Methods: We constructed a directed relational network and calculated network metrics for 'degree', 'betweenness', 'closeness' and 'eigenvector' centrality to understand individual‐level transmission patterns. We analysed network components and modularity to identify sub‐network structures with disproportionately big effects. Results: We detected 68 connections between 46 confirmed cases, of whom 27 (58.7%) were ancillary support staff, 7 (15.2%) caregivers, 6 (13%) patients and 2 (4.4%) nurses. Among the 10 most important cases selected by each SNA network metric, transmission dynamics clustered in 17 cases, of whom 12 (70.6%) cases were ancillary support staff. Ancillary support staff also constituted 71.1% of cases in the dominant sub‐network and 68.8% of cases in the three largest sub‐communities. Conclusions: We identified non‐clinical ancillary support staff, who are responsible for room service and food distribution in hospital wards in Vietnam, as a group with disproportionally big impacts on transmission dynamics during this outbreak. Our findings call for a holistic approach to nosocomial outbreak prevention and response that includes both clinical and non‐clinical hospital staff. Our work also shows the potential of SNA as a complementary outbreak investigation method to better understand infection patterns in hospitals and similar settings. [ABSTRACT FROM AUTHOR]

A core–shell Fe3O4@C nanocomposite consisting of a layer of amorphous carbon functionalized on the Fe3O4 surface has been synthesized via a simple hydrothermal process of a suspension of Fe3O4 nanoparticles and glucose. Using this approach, the thickness of the amorphous carbon shell can be well controlled by changing the mass ratio of Fe3O4 nanoparticles to glucose. The specific characteristics of Fe3O4@C were also analyzed. The results obtained revealed that the adsorption of methylene blue (MB) onto the Fe3O4@C nanosorbent is strongly dependent on the thickness of the carbon shell. The Fe3O4@C nanosorbent could be recovered for reuse with 83% effective removal at the 5th cycle. With its excellent performance, Fe3O4@C nanocomposite has great potential applications as a smart nanosorbent, including high adsorption capacity, recoverability and recyclability for organic dye removal. [ABSTRACT FROM AUTHOR]

Verbascoside is isolated from the whole plants of the Verbenaceae family and demonstrates significant levels of bioactivity. In this work, we report on the isolation of verbascoside, a phenolic glycoside, from the stems of Clerodendrum inerme collected in Vietnam and verify its structure by comparing its spectroscopic data with those reported in the literature. Verbascoside is then applied as a monomer for the electrochemical deposition of a layer of polyverbascoside onto glassy carbon electrodes toward Cu2+ sensing. Electrochemical results demonstrate that the polyverbascoside-modified glassy carbon electrode is highly selective for Cu2+ ions compared to other evaluated ions including Ni2+ and Co2+. The developed sensor can detect Cu2+ in a concentration range from 0 to 175 μM with a sensitivity of 0.372 µA µM−1 and a limit of detection of 50 nM Cu2+ ions. [ABSTRACT FROM AUTHOR]

This study analyzes whether ongoing liberalization has resulted in more profound trade expansion for Indonesia versus regional partner countries. A gravity model is first employed to find whether regional trade agreements resulted in more significant intra-regional exports or diverted trade. This study applies the generalized method of moment (GMM-sys) and the Poisson pseudo-maximum likelihood (PPML) estimator. Four groups of manufactured products are aggregated according to technology intensity, and two nature-based groups of products are estimated in the dynamic panel model. Additionally, revealed comparative advantage (RCA) and a trade balance index (TBI) for 5120 products are used to map goods based on specialization–advantage patterns. The gravity model indicates that regional trade agreements supported trade in manufactured and naturally sourced goods but not in high-tech and primary goods. Additionally, export expansion took place in goods that revealed comparative advantage and export specialization. Competition has increased between Indonesia and four regional trade partners: China, India, Thailand, and Vietnam. Indonesia gained from trading primary materials while losing in some low-cost manufacturing sectors. The potential for trade expansion remains large, as trade patterns differ among regional partners. [ABSTRACT FROM AUTHOR]

Graphene oxide (GO) and reduced GO (rGO) have become the most exciting material in the applications for photocatalysts. However, the GO composite film-based high-activity photocatalyst is usually not durable in aqueous solution. Therefore, in this paper, the non-woven polyester fabric (NWPF)-supported cuprous oxide nanoparticles (Cu2O) decorated on rGO (Cu2O/rGO@NWPF) membrane were suggested to synthesize via chemical reduction method. The Cu2O/rGO@NWPF nanocomposite was characterized by X-ray diffraction, transmission electron microscopy, Raman spectroscopy, Fourier transform infrared spectroscopy, Brunauer–Emmett–Teller method, and energy-dispersive X-ray spectroscopy analysis. The combination of rGO and Cu2O particles supported on NWPF exhibited enhanced photocatalytic degradation of methylene blue (MB) under solar light and achieved 96% of MB removal efficiency in 120 min. The photocatalytic mechanism and the synergistic effects between Cu2O nanoparticles and rGO sheets were comprehensively investigated. The Cu2O/rGO@NWPF catalyst showed excellent stability with retained catalytic activity in four consecutive recycles. The obtained results indicated that the Cu2O/rGO@NWPF composite has a good application potential to large-scale water treatment at lakes or rivers. [ABSTRACT FROM AUTHOR]

This study investigates the determinants of comparative advantage of crude oil production in 10 OPEC and 10 non‐OPEC countries over the period 1990–2016. The study calculates the comparative advantage using the Normalized Revealed Comparative Advantage index (NRCA) and further estimates the relationship between the comparative advantage and three explanatory variables using panel autoregressive distributed lag (panel ARDL) in a separate panel for each group of countries. The result of NRCA shows that all OPEC countries have a comparative advantage in crude oil production, whereas five of the 10 non‐OPEC countries have a comparative advantage in crude oil production. The result of the ARDL indicates that crude oil price (COP) and average of daily production (ADP) positively affect comparative advantage of crude oil production. The effect of natural resources (PR) is negative, suggesting that an increase in PR decreases the comparative advantage of these countries—a result that aligns with the philosophy of Hotelling rent. Finally, bidirectional Granger causality is established between all the investigated variables in both panels. [ABSTRACT FROM AUTHOR]

Nanostructured cathode materials based on Mn-doped olivine LiMnxFe1−xPO4 (x = 0, 0.1, 0.2, and 0.3) were successfully synthesized via a hydrothermal route. The field-emission scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) analyzed results indicated that the synthesized LiMnxFe1−xPO4 (x = 0, 0.1, 0.2, and 0.3) samples possessed a sphere-like nanostructure and a relatively homogeneous size distribution in the range of 100–200 nm. Electrochemical experiments and analysis showed that the Mn doping increased the redox potential and boosted the capacity. While the undoped olivine (LiFePO4) had a capacity of 169 mAh g−1 with a slight reduction (10%) in the initial capacity after 50 cycles (150 mAh g−1), the Mn-doped olivine samples (LiMnxFe1−xPO4) demonstrated reliable cycling tests with negligible capacity loss, reaching 151, 147, and 157 mAh g−1 for x = 0.1, 0.2, and 0.3, respectively. The results from electrochemical impedance spectroscopy (EIS) accompanied by the galvanostatic intermittent titration technique (GITT) have resulted that the Mn substitution for Fe promoted the charge transfer process and hence the rapid Li transport. These findings indicate that the LiMnxFe1−xPO4 nanostructures are promising cathode materials for lithium ion battery applications. [ABSTRACT FROM AUTHOR]

Image processing technologies are available for high-throughput acquisition and analysis of phenotypes for crop populations, which is of great significance for crop growth monitoring, evaluation of seedling condition, and cultivation management. However, existing methods rely on empirical segmentation thresholds, thus can have insufficient accuracy of extracted phenotypes. Taking maize as an example crop, we propose a phenotype extraction approach from top-view images at the seedling stage. An end-to-end segmentation network, named PlantU-net, which uses a small amount of training data, was explored to realize automatic segmentation of top-view images of a maize population at the seedling stage. Morphological and color related phenotypes were automatic extracted, including maize shoot coverage, circumscribed radius, aspect ratio, and plant azimuth plane angle. The results show that the approach can segment the shoots at the seedling stage from top-view images, obtained either from the UAV or tractor-based high-throughput phenotyping platform. The average segmentation accuracy, recall rate, and F1 score are 0.96, 0.98, and 0.97, respectively. The extracted phenotypes, including maize shoot coverage, circumscribed radius, aspect ratio, and plant azimuth plane angle, are highly correlated with manual measurements (R2 = 0.96–0.99). This approach requires less training data and thus has better expansibility. It provides practical means for high-throughput phenotyping analysis of early growth stage crop populations. [ABSTRACT FROM AUTHOR]

In this work, we propose a simple approach for fabrication of an electrochemical sensor for copper (II) ion determination in aqueous solution based on using a hydroxyapatite nano-rods/chitosan (HA/CS) nanocomposite coated on glassy carbon electrode (GCE) surface. Firstly, hydroxyapatite (HA) nano-rods has been synthesized by a simple precipitation reactions using Ca(OH)2 slurry and orthophosphoric acid (H3PO4) as precursors. After that, as-synthesized HA was dispersed into chitosan (CS) matrix to HA/CS-modify GCE by a drop casting technique. Characteristic of HA and HA/CS coating on GCE have been analysed by Transmission/Scanning Electron Microscope (TEM/SEM), X-ray Diffraction (XRD) and Fourier-Transform infrared spectroscopy (FT-IR) techniques. Electrochemical activities of neat GCE, CS-modified GCEs (GCE/CS) and HA/CS-modified GCE (GCE/HA/CS) have been evaluated in sodium acetate (NaAc-HAc) buffer with presence/absence of Ni2+, Co2+ or Cu2+ ions to test whether sensitive and selective of these developed Cu2+ sensors. Evaluated results demonstrated that GCE/HA/CS sensor has a sensitivity to Cu2+ ion of 7.688 ± 0.5324 µA mM− 1, it is the most sensitive to Cu2+ ions compared with GCE or GCE/CS. In additional, proposed Cu2+ electrochemical sensor has been applied to determine Cu2+ ions concentration in tap water with a high recoveries was found. [ABSTRACT FROM AUTHOR]

Roselle (Hibiscus sabdariffa L.) is an annual shrub popularly grown in tropical and subtropical areas. Although Roselle fruit has been used for a long time as a herbal tea due to its high content of bioactive compounds like phenolic acids and anthocyanins, the studies on the effects of the drying process and brewing conditions on the content of beneficial components and bioactivities of Roselle tea is limited. In this study, the influence of drying temperature on the retention of total phenolic content (TPC) and antioxidant capacity (AC) of the dried Roselle and the effects of brewing conditions including water temperature, liquid-solid ratio and brewing time on total soluble solid (TSS) content, total phenolic content, and antioxidant capacity of Roselle tea were investigated. The drying at 80 °C produced the dried Roselle with the highest retention of TPC (25.196 mg GAE/g) and AC (IC50 of 2.2 mg/mL for 2,2-diphenyl-1-picrylhydrazyl (DPPH) inhibition) and the highest sensory quality compared to the drying at other temperatures. The brewing process using hot water at 90 °C with the solid-liquid ratio of 1:10 (g/mL) for 30 min resulted in the highest TSS content (5.4 oBx), TPC (12.7 mg GAE/g dried Roselle) and AC (73.3% DPPH inhibition) of the Roselle tea. Thus, the drying at 80 °C combined with the brewing of dried Roselle for 30 min using 90 °C hot water with the solid-liquid ratio of 1:10 (g/mL) are recommended to produce Roselle tea with the highest content of beneficial ingredients. [ABSTRACT FROM AUTHOR]

In this paper, Fe3O4/graphene oxide/chitosan (FGC) nanocomposite was synthesized using coprecipitation method for application to removal of nickel ion (Ni(II)) from aqueous solution by adsorption process. To determine residue Ni(II) ions concentration in aqueous solution after adsorption process, we have used UV-Vis spectrophotometric method, which is an effective and exact method for Ni(II) monitoring at low level by using dimethylglyoxime (DMG) as a complex reagent with Ni(II), which has a specific adsorption peak at the wavelength of 550 nm on UV-Vis spectra. A number of factors that influence Ni(II) ions adsorption capacity of FGC nanocomposite such as contact time, adsorption temperature, and adsorbent dosage were investigated. Results showed that the adsorption equilibrium is established after 70 minutes with the adsorbent dosage of 0.01 g.mL−1 at 30°C (the room temperature). The thermodynamic and kinetic parameters of this adsorption including free enthalpy change (∆G0), enthalpy change (∆H0), entropy change (∆S0), and reaction order with respect to Ni(II) ions were also determined. The Ni(II) ions adsorption equilibrium data are fitted well to the Langmuir isotherm and the maximum monolayer capacity (qmax) is 12.24 mg.g−1. Moreover, the FGC adsorbent can be recovered by an external magnet; in addition, it can be regenerated. The reusability of FGC was tested and results showed that 83.08% of removal efficiency was obtained after 3 cycles. The synthesized FGC nanocomposite with many advantages is a promising material for removal of heavy metal ions from aqueous solution to clean up the environment. [ABSTRACT FROM AUTHOR]

A floating market in Bangkok and its vicinity in the Thai Central plains is usually packed as a tourism product that offers visitors an opportunity to experience local ways of life as in the past. An interview and observation were carried out on September 29, 2012 to get the opinion of international, local visitors and local vendors about Talingchan Floating Market. The Talingchan floating market attracts the locals, families, students and international visitors. Results based on observation and analyses of interviews indicate that Talingchan floating market is an authentic canal-side community market, not a thematic floating market village. The results generated a snapshot of both visitors and community sentiments with understanding of the triple bottom line effects of tourism on Talingchan floating market. There is a clear demonstration of the linkage between tourism and canal side community that has played important role in reducing poverty in the area and dispersion of tourism earnings to local community. The researcher sees the market's potential to develop further provided fresh challenges are adequately addressed without damaging culture and environment by making necessary changes to present it as an attractive tourist attraction and to ensure its future sustainability. [ABSTRACT FROM AUTHOR]

Optical immersion lithography utilizes liquids with refractive indices >1 (the index of air) below the last lens element to enhance numerical aperture and resolution, enabling sub-40-nm feature patterning. This shift from conventional dry optical lithography introduces numerous challenges requiring innovations in materials at all imaging stack levels. In this article, we highlight the recent materials advances in photomasks, immersion fluids, topcoats, and photoresists. Some of the challenges encountered include the fluids' and photomask materials' UV durability the high-index liquids' compatibility with topcoats and photoresists, and overall immersion imaging and defectivity performance. In addition, we include a section on novel materials and methods for double-patterning lithography-a technique that may further extend immersion technology by effectively doubling a less dense pattern's line density. [ABSTRACT FROM AUTHOR]

This study empirically analyzes the influence of contract farming on income and farming difficulties in Vietnam by using the econometric models and theoretically identifying the affecting mechanism of contract farming on income, sustainability, and welfare by using the qualitative method. The empirical results show that contract farming insignificantly impacts farms' income while it can facilitate farming activities and decrease difficulties. The factors of education—head, gender of head, type of crop, and technology may affect farmers' income. The impacting mechanism of contract farming on income, sustainability, and welfare is theoretically proposed as follows: Contract farming initially impacts the intermediate factors such as cooperative, market access, knowledge and skill, product quality, technology, and support. These factors then affect capacity, linkage, quality, and certification which can enhance farmers' competitiveness. In the long term, stronger competitiveness, higher price, increasing productivity, and lower cost may significantly improve income, sustainability, and welfare. In general, contract farming may have positive impacts on income, sustainability, and welfare in the medium term and long term. In the short term, the result is not significant due to the similar or lower price comparing with the spot market price, growing production cost, decreasing productivity, and weak contract performance. The findings may help policymakers decide how to expand contract farming and its benefits. Economic scholars can test and compare both quantitative and qualitative findings in other contexts. [ABSTRACT FROM AUTHOR]

Background: Little is known about the association of hyperglycemia with the development of ventricular tachycardia (VT) in patients hospitalized with acute myocardial infarction (AMI) which we examined in the present study. The objectives of this community-wide observational study were to examine the relation between elevated serum glucose levels at the time of hospital admission for AMI and occurrence of VT, and time of occurrence of VT, during the patient's acute hospitalization. Methods: We used data from a population-based study of patients hospitalized with AMI at all central Massachusetts medical centers between 2001 and 2011. Hyperglycemia was defined as a serum glucose level ≥ 140 mg/dl at the time of hospital admission. The development of VT was identified from physicians notes and electrocardiographic findings by our trained team of data abstractors. Results: The average age of the study population was 70 years, 58.0% were men, and 92.7% were non-Hispanic whites. The mean and median serum glucose levels at the time of hospital admission were 171.4 mg/dl and 143.0, respectively. Hyperglycemia was present in 51.9% of patients at the time of hospital admission; VT occurred in 652 patients (15.8%), and two-thirds of these episodes occurred during the first 48 h after hospital admission (early VT). After multivariable adjustment, patients with hyperglycemia were at increased risk for developing VT (adjusted OR = 1.48, 95% CI = 1.23–1.78). The presence of hyperglycemia was significantly associated with early (multivariable adjusted OR = 1.39, 95% CI = 1.11–1.73) but not with late VT. Similar associations were observed in patients with and without diabetes and in patients with and without ST-segment elevation AMI. Conclusions: Efforts should be made to closely monitor and treat patients who develop hyperglycemia, especially early after hospital admission, to reduce their risk of VT. [ABSTRACT FROM AUTHOR]

A method is described for the synthesis of a nanocomposite containing FeOOH and N-doped carbon nanosheets. The nanocomposite was synthesized by a hydrothermal method using a Fe3O4/chitosan nanocomposite as the precursor. The nanocomposite displays peroxidase-like activity and catalyzes the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) by H2O2. This results in the formation of a blue colored product with an absorption maximum at 652 nm in the UV-vis spectra. Based on these findings, colorimetric assays were worked out for both hydrogen peroxide and glucose. The H2O2 assay works in the 5 to 19 μM concentration range, and the limit of detection is 5 nM. The glucose assay works in the 8 μM to 0.8 mM concentration range and has a 0.2 μM detection limit. The method was successfully applied to the determination of glucose in human urine.Schematic of the hydrothermal synthesis of a FeOOH/N-doped carbon nanocomposite. It was used to replace peroxidase enzyme for the catalytic oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) in a visual colorimetric test for glucose in human urine. [ABSTRACT FROM AUTHOR]