bluuebunny/crossref_metadata_2025 huggingface dataset:
Ground Behavior of Parallel Tunnels in Response to Variations in Groundwater Flow
Authors: Kim Mintae
Published: October 2024

With the steady expansion of urban development, the importance of tunnel design and construction has increased, particularly with respect to changes in the groundwater level. Excavation without considering groundwater variations can destabilize tunnels; and this problem has been exacerbated by recent climate change-induced groundwater level fluctuations. This study evaluates the impact of various factors, such as filler width, lateral earth pressure coefficient, and groundwater flow, on tunnels by analyzing the ground behavior around parallel tunnels in Korea. The findings reveal that an increase in filler width reduces settlement and displacement, while the coefficient of lateral earth pressure affects convergence displacement to a higher degree than other settlements. Moreover, steady flow conditions are observed to wield a more pronounced impact on ground behavior than unsteady ones. These findings emphasize the importance of thoroughly evaluating groundwater flow characteristics during tunnel excavation and provide essential data for the future design and construction of parallel tunnels.
A Study of the Rainwater Pumping Station Operation Plan to Reduce River Water Level
Authors: Kim Eungseok , Lee Seunghyun
Published: October 2024

Urban flood damage is caused by various and complex effects such as inland flood and external water flooding, so research on this is necessary. This study presented a rainwater pumping station operation technique that can suppress the rise in water levels in discharge rivers based on rainfall and pump operation scenarios in order to reduce inland water flooding and simultaneously consider external water levels. The research method used genetic algorithm (GA) optimization techniques to calculate the optimal operating level for each pump, and based on this, an operating scenario was created to minimize pump operation. In addition, after constructing a rainfall scenario based on the probability rainfall in Seoul, an optimal pump operation technique that can reduce the external water level while minimizing the inundation of domestic water was proposed. The results of the study showed that as the rainfall intensity increases, the flooding increases and the peak depth of the runoff increases. In addition, as the pumping scenario changes from 1 to 11, the number of pumping operations decreases, which reduces the drainage volume of the pumps, which increases the flooding.
Proposed Technique for Estimating Rainwater Storage Tank Locations Using Vulnerability Analysis of Critical Flooding Nodes
Authors: Kim Eungseok , Lee Seunghyun
Published: October 2024

Even if a pumping station, which is a representative structural flood defense facility, operates optimally, flooding occurs at certain nodes in the drainage area. In other words, even if rainwater pumping stations and rainwater storage tank, which are structural flood defense measures, operate at maximum, it is necessary to review areas where overflow occurs. Therefore, in areas where it is impossible to protect against inland flooding using structural flood defense measures alone, new flood defense measures are required. In this study, based on previous research on rainwater pumping station operation techniques to reduce critical flooding, the Daelim 3 region was divided into 45 basic areas and vulnerability analysis techniques were applied to select the location of rainwater storage tank for effective flood defense. A possible technique is presented in this paper. As a result of the study, sub-region 1 had the highest impact index value, so installing a rainwater storage tank was calculated to be more effective in preventing floods than installing a rainwater storage tank in other sub-regions. The priority-estimation technique for flood defense facilities presented in this study can be effective in establishing plans for flood control structures other than rainwater storage tank.
Performance Evaluation of Desalination Battery Systems based on Synthesis Method of Carbon Nanotube-Carbon Felt Composite Electrodes
Authors: Kim Sanggyun , Kim Junghyeon , Lee Sujin , Byun Imgyu
Published: October 2024

To enhance chlorine ion removal and increase the current charging capacity of a desalination battery system, carbon nanotubes were applied to a carbonaceous electrode. Two types of composite electrodes were fabricated by attaching multiwalled carbon nanotubes (MWCNTs) to a carbon felt (CF) electrode via dip coating (D-CNT@CF) and electrophoresis (E-CNT@CF). These composite electrodes were then tested within a desalination battery system to evaluate their chlorine ion removal efficiency and current charging performance during the charging process. Microflocs of MWCNTs were observed on the surface of D-CNT@CF, whereas a uniform coating of MWCNTs was achieved on the surface of E-CNT@CF. Performance evaluations revealed that chlorine ion removal rates improved by 3.5% for D-CNT@CF and by 19.4% for E-CNT@CF compared to that of CF. Furthermore, the time required to reach maximum current charge was 40.0% for D-CNT@CF and E-CNT compared to CF. @CF decreased by 60.0%. These findings suggest that surface modification of carbonaceous electrodes through electrophoresis can result in a more stable coating and improve the performance of desalination battery systems.
A Study on the Indoor Heating Effect of Blue Green Roofs during Cold Waves
Authors: Lee Jung Min , Cha Sung Min , Kim Jae Moon , Kwon Soonchul
Published: October 2024

With the increasing frequency of heat-based climate disasters due to recent climate change, various technologies are being developed to mitigate their impacts. Blue-green roofs (BGR) is a technology that consists of rainwater storage tanks and grass layers installed on building rooftops to reduce the infiltration of cold or heat into the building interiors. This study analyzed the indoor temperature changes between two buildings with equal rooftop area, one equipped with a BGR and the other without, during winter season to evaluate their heating effects. The results indicated an average heating effect of 0.56 °C across the entire monitoring period for the building with a BGR. The heating effect was observed only at temperature ranges below 6.5 °C, with no effect at higher temperatures. This study suggests that even installing a roof-based system can provide some degree of heating benefits. Further research and development are needed to improve the heating efficien through additional technological advancements.
A Study on the Effectiveness of Climate Adaptation Materials for Urban Heat Islands using Digital Twin and Computational Fluid Dynamics
Authors: Kim Jaekyoung , Lee Jung Min , Jun Hwandon
Published: October 2024

This study analyzed the impact of climate adaptation materials on the mitigation of urban heat islands (UHI) using digital twin visualization and computational fluid dynamics (CFD) technology. The effects of UHI due to increased impervious surfaces have become more pronounced, and climate-adaptation materials are gaining attention as potential solutions. In this study, the impact of climate adaptation materials on UHI mitigation was analyzed using the CFD program STAR-CCM+ based on the finite volume method (FVM). The selected research site was Byeoryang-dong, Gwacheon City, and four simulation scenarios were created based on the emissivity values of the asphalt and concrete materials. The results showed that application of climate adaptation materials decreased the surface and aboveground (1.5 m) temperatures by 6.3 and 0.8 °C, respectively. This study suggests that climate adaptation materials can significantly mitigate UHI.
Assessing the Decadal Predictability of Land and Ocean Carbon Uptake
Authors: Séférian Roland , Berthet Sarah , Chevallier Matthieu
Published: February 2018

The decadal predictability of carbon fluxes has been examined over continents and oceans using a “perfect model” approach based on a 400 year preindustrial simulation and five 10‐member ensembles from the Centre National de Recherches Météorologiques‐Earth System Model version 1. From these experiments, we find that the global land uptake and ocean carbon uptake are potentially predictable by up to six years, with a median predictability horizon of four years. Predictability of global carbon uptake is prominently driven by the ocean's predictability. The difference in predictability between ocean and land carbon fluxes stems from the relative capability of ocean or land to generate low‐frequency fluctuations in carbon flux. Indeed, ocean carbon fluxes display low‐frequency variability that emerges from the year‐to‐year variability in the North Atlantic, the North Pacific, and the Southern Ocean. The Southern Ocean carbon uptake can be predicted up to six years in advance and explains most of the global carbon uptake predictability.
Changes in ENSO Activity During the Last 6,000 Years Modulated by Background Climate State
Authors: An Soon‐Il , Im Seul‐Hee , Jun Sang‐Yoon
Published: February 2018

Various proxy records show that El Niño–Southern Oscillation (ENSO) activity has changed from calm to active during the last 6,000 years. However, it is so far unclear whether orbital forcing has solely induced such a dramatic change. In this study, we performed a transient run for the last 6,000 years using an Earth system model of intermediate complexity affected by orbital forcing only without changes due to other climate forcing, and then its time‐varying background states were implemented into an intermediate atmosphere‐ocean coupled model for ENSO. ENSO activity simulated by the intermediate atmosphere‐ocean coupled model during the last 6,000 years resembled the observed proxy data, inferring that orbital forcing mainly leads to changes in ENSO activity during the last 6,000 years. From additional sensitivity experiments, we found that a change in sea surface temperature background conditions is primarily responsible for the observed ENSO activity over the last 6,000 years through modifying the anomalous horizontal thermal advection of the mean SST gradient.
The Influence of Water Storage in Marine Sediment on Sea‐Level Change
Authors: Ferrier Ken L. , Li Qi , Pico Tamara , Austermann Jacqueline
Published: February 2018

Sea‐level changes are of wide interest because they provide information about Earth's internal structure and the sensitivity of ice sheets to climate change. Here we illustrate the sensitivity of sea level to marine sedimentary water storage by modeling sea‐level responses to a synthetic global sediment redistribution history in which rates and patterns of erosion and deposition are similar to those at present and steady in time from the Last Interglacial to present. Our simulations show that if sediment redistribution were accounted for but sedimentary water storage were neglected, modeled sea‐level changes could be overestimated by ~2 ± 1 m of global mean sea‐level equivalent, a significant fraction of published estimates of 6–9 m of global mean sea‐level change since the Last Interglacial. These results show that sedimentary water storage may significantly contribute to changes in Earth's long‐term seawater budget over >105 year timescales and underscore the importance of accounting for it in modeling long‐term sea‐level changes.
Was the Deepwater Horizon Well Discharge Churn Flow? Implications on the Estimation of the Oil Discharge and Droplet Size Distribution
Authors: Boufadel Michel C. , Gao Feng , Zhao Lin , Özgökmen Tamay , Miller Richard , King Thomas , Robinson Brian , Lee Kenneth , Leifer Ira
Published: February 2018

Improved understanding of the character of an uncontrolled pipeline flow is critical for the estimation of the oil discharge and droplet size distribution both essential for evaluating oil spill impact. Measured oil and gas properties at the wellhead of the Macondo255 and detailed numerical modeling suggested that the flow within the pipe could have been “churn,” whereby oil and gas tumble violently within the pipe and is different from the bubbly flow commonly assumed for that release. The churn flow would have produced 5 times the energy loss in the pipe compared to bubbly flow, and its plume would have entrained 35% more water than that of the bubbly flow. Both findings suggest that the oil discharge in Deepwater Horizon could have been overestimated, by up to 200%. The resulting oil droplet size distribution of churn flow is likely smaller than that of bubbly flow.
Mechanochemical Effect on Maturation of Carbonaceous Material: Implications for Thermal Maturity as a Proxy for Temperature in Estimation of Coseismic Slip Parameters
Authors: Kaneki S. , Ichiba T. , Hirono T.
Published: February 2018

Because shear stress in a fault is directly related to the frictional heat generated during slip, the thermal maturity of carbonaceous material has been used as a proxy for fault‐rock temperature. We used infrared and Raman spectroscopic analyses and friction and heating experiments to investigate enhancement of the maturation of lignite by shear damage (the mechanochemical effect) and explored the resultant implications for the use of the thermal maturity of lignite as a proxy for temperature. We showed that higher shear stress applied to lignite samples resulted in greater progression of the thermal destruction of aliphatic C─H chains and the survival of the stronger C─C bonds. Thus, we demonstrated that shear damage during earthquake slip causes mechanochemical enhancement of organochemical reactions related to the aromatization of lignite. Our results suggest that shear stress estimated from Raman spectroscopic analyses in previous studies might have been overestimated.
Methane Leakage From Hydrocarbon Wellbores into Overlying Groundwater: Numerical Investigation of the Multiphase Flow Processes Governing Migration
Authors: Rice Amy K. , McCray John E. , Singha Kamini
Published: February 2018

Methane leakage due to compromised hydrocarbon well integrity can lead to impaired groundwater quality. Here we use a three‐dimensional, multiphase (vapor and aqueous), multicomponent (methane, water, salt), numerical model (TOUGH2 EOS7C) to investigate hydrogeological conditions that could result in groundwater contamination from natural gas wellbore leakage that migrates upward toward a freshwater aquifer. The conceptual model used for the simulations assumes methane leakage at 20–30 m below groundwater. We perform 180 simulations for a sensitivity analysis, examining (1) multiphase flow parameters related to storage, capillarity, and relative permeability, including porosity (ϕ), initial fluid‐phase saturation (SL), and van Genuchtennandα, (2) geostatistical variations in intrinsic permeability (ki), and (3) methane source‐zone pressure. Simulated meankivalues are 10−18and 10−13m2with variances of 1 and 5 m4. Simulated source‐zone pressures range from just over ambient hydrostatic pressure at the depth of leakage (100 kPa) to the maximum pressure that steel casings are commonly rated to withstand (20,340 kPa).ki, initialSL,ϕ, and van Genuchten'snandαwere the most important parameters in determining the volume of methane reaching groundwater during a given time period. Multiphase parameterization of formations underlying freshwater aquifers and overlying hydrocarbon production zones is fundamental to assessing aquifer vulnerability to methane leakage.
Effects of Unsaturated Flow on Hillslope Recession Characteristics
Authors: Luo Zhaoyang , Shen Chengji , Kong Jun , Hua Guofen , Gao Xinyu , Zhao Zhongwei , Zhao Hongjun , Li Ling
Published: February 2018

Recession flow analysis is usually conducted to infer hydraulic parameters of hillslope aquifers. Various Boussinesq equation‐based models, both linear and nonlinear, have been used to analyze the recession curves for sloping aquifers, with a focus on the long‐time recession behavior. Based on a modified Boussinesq equation with capillarity incorporated, we demonstrate the significant effect of unsaturated flow on the recession curve, which result in three (instead of two) power law regimes with two transition points (instead of one) corresponding to the formation of a fully unsaturated zone at the adjacent area of the upslope boundary and across the whole domain, respectively. The results show that the power of the second and third recession regime is variable, depending on the slope angles, soil types, and hillslope geometries. The unsaturated flow effects also lead to the absence of drastic drop of
at the transition between the first and second regime, which was predicted by previous numerical models but has not been observed in the field or laboratory experiments. These findings have important implications for recession flow analysis in studies of hillslope aquifers.
Seasonal Variability of Magnetotactic Bacteria in a Freshwater Pond
Authors: He Kuang , Roud Sophie C. , Gilder Stuart A. , Egli Ramon , Mayr Christoph , Petersen Nikolai
Published: February 2018

Magnetotactic bacteria (MTB) synthesize ferrimagnetic crystals that contribute to the remanent magnetization in sediments, yet knowledge of how MTB populations vary in natural environments over time remains limited. We report abundances of three MTB morphotypes from nine sites collected and measured every month over a two‐year period from a natural pond near Munich, Germany. Morphotype populations underwent coherent temporal trends among the nine sites—especially at proximal sites with similar water depths. MTB populations varied independently of bottom water oxygen concentrations or temperature over the two‐year period, except for spirilla, which flourished during the summer at some sites. Magnetic properties of the sediments did not reflect living MTB abundances, but instead varied with water depth. Deeper sites, which were also lower in organic carbon, nitrogen, and oxygen concentrations than shallower sites, had higher saturation magnetizations and were richer in single‐domain particles.
High‐Density Stretchable Electrode Grids for Chronic Neural Recording
Authors: Tybrandt Klas , Khodagholy Dion , Dielacher Bernd , Stauffer Flurin , Renz Aline F. , Buzsáki György , Vörös János
Published: February 2018

Electrical interfacing with neural tissue is key to advancing diagnosis and therapies for neurological disorders, as well as providing detailed information about neural signals. A challenge for creating long‐term stable interfaces between electronics and neural tissue is the huge mechanical mismatch between the systems. So far, materials and fabrication processes have restricted the development of soft electrode grids able to combine high performance, long‐term stability, and high electrode density, aspects all essential for neural interfacing. Here, this challenge is addressed by developing a soft, high‐density, stretchable electrode grid based on an inert, high‐performance composite material comprising gold‐coated titanium dioxide nanowires embedded in a silicone matrix. The developed grid can resolve high spatiotemporal neural signals from the surface of the cortex in freely moving rats with stable neural recording quality and preserved electrode signal coherence during 3 months of implantation. Due to its flexible and stretchable nature, it is possible to minimize the size of the craniotomy required for placement, further reducing the level of invasiveness. The material and device technology presented herein have potential for a wide range of emerging biomedical applications.
Metal‐Free Multicomponent Reaction for Synthesis of 4,5‐Disubstituted 1,2,3‐(NH)‐Triazoles
Authors: Wu Guang‐Long , Wu Qin‐Pei
Published: February 2018

A metal‐free domino reaction was developed for efficient synthesis of 4,5‐disubstituted 1,2,3‐(NH)‐triazoles by sequentially coupling sulfur salts with aldehydes and sodium azide. In the presence of L‐proline, olefinic sulfur salt intermediates rather than epoxides are formed in situ via the coupling of sulfur salts with aldehydes and cyclize with azide ion. This process features mild conditions, high efficiency, commercially available starting materials, and wide substrate scope.

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Preparation of novel palladium nanoparticles supported on magnetic iron oxide and their catalytic application in the synthesis of 2‐imino‐3‐phenyl‐2,3‐dihydrobenzo[d]oxazol‐5‐ols
Authors: Habibi Davood , Heydari Somayyeh , Afsharfarnia Mina , Moghimpour Fatemeh
Published: February 2018

Novel Pd nanoparticles were prepared in five successive stages: 1) preparation of the Fe3O4 magnetic nanoparticles (Fe3O4 MNPs), 2) coating of Fe3O4 MNPs with SiO2 (Fe3O4@SiO2), 3) functionalization of Fe3O4@SiO2 with 3‐chloropropyltrimethoxy‐ silane (CPTMS) ligand (Fe3O4@SiO2@CPTMS), 4) further functionalization with 3,5‐diamino‐1,2,4‐triazole (DAT) ligand (Fe3O4@SiO2@CPTMS @DAT), and 5) the complexation of Fe3O4@SiO2@CPTMS@DAT with PdCl2 (Fe3O4@SiO2@CPTMS@ DAT@Pd). Then, the obtained Pd nano‐catalyst characterized by different methods such as the elemental analysis (CHN), FT‐IR, XRD, EDX, SEM, TEM, TG‐DTA and VSM. Finally, the Pd catalyst was applied for the synthesis of various 2‐imino‐3‐phenyl‐2,3‐dihydrobenzo[d]oxazol‐5‐ols.
Novel (N‐heterocyclic carbene)Pd(pyridine)Br2 complexes for carbonylative Sonogashira coupling reactions: Catalytic efficiency and scope for arylalkynes, alkylalkynes and dialkynes
Authors: Ibrahim Mansur , Malik Imran , Mansour Waseem , Sharif Muhammad , Fettouhi Mohammed , El Ali Bassam
Published: February 2018

New N,N′‐substituted imidazolium salts and their corresponding dibromidopyridine–palladium(II) complexes were successfully synthesized and characterized. Reactions of palladium bromide with the newly synthesized N,N′‐substituted imidazolium bromides (2a and 2b) in pyridine afforded the corresponding new N‐heterocyclic carbene pyridine palladium(II) complexes (3a and 3b) in high yields. Their single‐crystal X‐ray structures show a distorted square planar geometry with the carbene and pyridine ligands in trans position. Both complexes show a high catalytic activity in carbonylative Sonogashira coupling reactions of aryl iodides and aryl diiodides with arylalkynes, alkylalkynes and dialkynes.
Preparation, characterization and heterogeneous catalytic applications of GO/Fe3O4/HPW nanocomposite in chemoselective and green oxidation of alcohols with aqueous H2O2
Authors: Darvishi Kamran , Amani Kamal , Rezaei Manuchehr
Published: February 2018

Graphene oxide‐Fe3O4‐NH3+H2PW12O40‐ magnetic nanocomposite (GO/Fe3O4/HPW) was prepared by linking amino‐functionalized Fe3O4 nanoparticles (Fe3O4‐NH2) on the graphene oxide (GO), and then grafting 12‐tungstophosphoric acid (H3PW12O40) on the graphene oxide‐magnetite hybrid (GO‐Fe3O4‐NH2). The obtained GO/Fe3O4/HPW nanocomposite was well characterized with different techniques such as FT‐IR, TEM, SEM, XRD, EDX, TGA‐DTA, AGFM, ICP and BET measurements. The used techniques showed that the graphene oxide layers were well prepared and the various stages of preparation of the GO/Fe3O4/HPW nanocomposites successfully completed. This new nanocomposite displayed excellent performance as a heterogeneous catalyst in the oxidation of alcohols with H2O2. The as‐prepared GO/Fe3O4/HPW catalyst was more stable and recyclable at least five times without significantly reducing its catalytic activity.
Fabrication of AgI/MIL‐53(Fe) Composites with Enhanced Photocatalytic Activity for Rhodamine B Degradation under Visible Light Irradiation
Authors: Han Yide , Zhang Lianxia , Bai Chunpeng , Wu Junbiao , Meng Hao , Xu Yan , Liang Zhiqiang , Wang Zhuopeng , Zhang Xia
Published: February 2018

AgI/MIL‐53(Fe) composites were fabricated through a simple solution method, and their photocatalytic activities on Rhodamine B (RhB) degradation were investigated. The results demonstrated that the introduction of AgI into the MIL‐53(Fe) was beneficial to the enhanced visible light response. Under visible light irradiation, almost 100 % RhB was bleached over AgI/MIL‐53(Fe) composites after 180 min. The promising photocatalytic performance was ascribed to three points: the existence of AgI helped to generate easily the electrons and holes in the composites; an intimate interfacial contact between MIL‐53 (Fe) and AgI offered the path for the charge carries transport; MIL‐53 (Fe) could fast transfer the excited electrons due to its inherent nature. Thus, these results were responsible for the effective inhibition of charge carrier recombination, resulting in an improved photocatalytic activity.
Nanocomposites based on titanium dioxide, modified by β‐cyclodextrin containing copolymers
Authors: Radchenko Olena , Sinelnikov Sergii , Moskalenko Oleg , Riabov Sergii
Published: February 2018

The range of titanium dioxide (TiO2) samples, modified by β‐cyclodextrin containing copolymers was synthesized. The copolymers obtained were investigated by different methods, such as ultraviolet‐, Fourier transform infrared‐spectroscopy, thermal mass spectroscopy, thermogravimetric analysis, transmission electron microscopy, and scanning electron microscopy. The modification of TiO2 is shown to promote a significant positive impact on the process of methyl orange absorption and photodegradation on its surface. The modified TiO2‐photocatalysts prepared in such way could be promising objects for water purification from organic pollutants. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46373.
Case series of aortic arch disease treated with branched stent-grafts
Authors: Clough R. E. , Spear R. , Van Calster K. , Hertault A. , Azzaoui R. , Sobocinski J. , Fabre D. , Haulon S.
Published: February 2018

Background

Surgical repair of aortic arch pathology is complex and associated with significant morbidity and mortality. Alternative approaches have been developed to reduce these risks, including the use of thoracic stent-grafts with fenestrations or in combination with bypass procedures to maintain supra-aortic trunk blood flow. Branched stent-grafts are a novel approach to treat aortic arch pathology.

Methods

Consecutive patients with aortic arch disease presenting to a single university hospital vascular centre were considered for branched stent-graft repair (October 2010 to January 2017). Patients were assessed in a multidisciplinary setting including a cardiologist, cardiac surgeon and vascular surgeon. All patients were considered prohibitively high risk for standard open surgical repair. The study used reporting standards for endovascular aortic repair and PROCESS (Preferred Reporting of Case Series in Surgery) guidelines.

Results

Some 30 patients (25 men) underwent attempted branch stent-graft repair. Mean age was 68 (range 37–84) years. Eighteen patients had chronic aortic dissection, 11 patients had an aneurysm and one had a penetrating ulcer. Fourteen patients had disease in aortic arch zone 0, six in zone 1 and ten in zone 2. Twenty-five patients had undergone previous aortic surgery and 24 required surgical revascularization of the left subclavian artery. Technical success was achieved in 27 of 30 patients. Four patients had an endoleak (type Ia, 1; type II, 3). The in-hospital mortality rate was three of 30. Mean length of follow-up was 12·0 (range 1·0–67·8) months, during which time 12 patients required an aortic-related reintervention.

Conclusion

Repair of aortic arch pathology using branched stent-grafting appears feasible. Before widespread adoption of this technology, further studies are required to standardize the technique and identify which patients are most likely to benefit.
Augmented reality experimentation on oxygen gas generation from hydrogen peroxide and bleach reaction
Authors: Gan Hong Seng , Tee Nicholas Yee Kwang , Bin Mamtaz Mohammad Raziun , Xiao Kevin , Cheong Brandon Huey‐Ping , Liew Oi Wah , Ng Tuck Wah
Published: February 2018

The appreciation and understanding of gas generation through processes is vital in biochemical education. In this work, an augmented reality tool is reported to depict the redox reaction between hydrogen peroxide and sodium hypochlorite solutions, two ubiquitous oxidizing agents, to create oxygen, a combustible gas. As it operates out of smartphones or tablets, students are able to conduct the exercise collaboratively, respond in a manner similar to an actual physical experiment, and able to depict the oxygen volume changes in relation to the volume of hydrogen peroxide of different concentrations used. The tool offers to help students acquire bench skills by limiting handing risks and to mitigate possible student anxiety on handling chemical materials and implements in the laboratory. The feedback received from Year 11 and 12 high school student participants in an outreach exercise indicate the overall effectiveness of this tool. © 2018 by The International Union of Biochemistry and Molecular Biology, 46(3):245–252, 2018.
Continuous Hydrothermal Liquefaction for Biofuel and Biocrude Production from Microalgal Feedstock
Authors: Lababpour Abdolmajid
Published: February 2018

Microalgal biomass processing by continuous hydrothermal liquefaction (HTL) has recently received much interest and can be used to convert microalgal biomass to biocrude oil and drop‐in fuels. This review focuses on the conversion of microalgae biomass to energy production through continuous HTL processes. In addition, processes for upgrading feedstocks and biocrude are also discussed. The feed of the biomass slurry is treated according to size and moisture regulations. Following separation of the gaseous, liquid, and solid phases, the determination of elemental, physical, and chemical fragments, yield of energy, and other properties of the various products is carried out. Homogeneous or heterogeneous catalysts improve the biocrude yield and quality as does higher moisture content. The high percentage of N2 and O2 in the feedstock results in lower quality products. This may be resolved through pre‐processing of the biomass, controlling of HTL processes conditions, and post‐upgrading processing of the HTL products. The promising potential of microalgae biomass for biocrude and drop‐in fuels may have an important contribution to the world's renewable energy sources through HTL in the near future.
Proof of Equivalent Catalytic Functionality upon Photon‐Induced and Thermal Activation of Supported Isolated Vanadia Species in Methanol Oxidation
Authors: Kortewille Bianca , Wachs Israel E. , Cibura Niklas , Pfingsten Oliver , Bacher Gerd , Muhler Martin , Strunk Jennifer
Published: February 2018

In this study, evidence is provided that isolated surface vanadia (VO4) species on SiO2 can similarly act as a thermal heterogeneous catalyst and as a heterogeneous photocatalyst. Structurally identical surface VO4 species catalyze the selective oxidation of methanol both by thermal activation and by UV‐light induction. Selectivity to formaldehyde appears to be unity. For the photocatalytic reaction at room temperature, formaldehyde desorption is rate limiting. With larger agglomerates or V2O5 nanoparticles, on the contrary, only the thermal reaction is feasible. This is tentatively attributed to the different positions of electronic states (HOMO/LUMO, valence/conduction band) on the electrochemical energy scale owing to the quantum size effect. Besides providing new fundamental insight into the mode of action of nanosized photocatalysts, our results demonstrate that tuning the photocatalytic reactivity of supported transition‐metal oxides by adjusting the degree of agglomeration is feasible.
Tuning Mg(II) Selectivity: Comparative Analysis of the Photophysical Properties of Four Fluorescent Probes with an Alkynyl‐Naphthalene Fluorophore
Authors: Walter Edward R. H. , Williams J. A. Gareth , Parker David
Published: February 2018

Four alkynyl‐1‐naphthyl fluorophores have been synthesised with tri‐ or pentadentate ligating groups suited to the binding of magnesium. Their photophysical and binding properties for magnesium, calcium and zinc ions have been assessed using absorption, emission and excitation spectroscopy. Each compound has a pKa value between 6.2 and 5.1 and exhibits no significant pH response around pH 7.2. Enhanced selectivity for Mg2+ over Ca2+ was observed with a pentadentate phosphinate substituted system, compared to its carboxylate analogue, due to a 10‐fold lowering of affinity for the Ca2+ ion. In each case, the overall dissociation constants for Mg2+ fall in the low mm range.
Transition Metal Ions Promote the Bioavailability of Hydrophobic Therapeutics: Cu and Zn Interactions with RNA Polymerase I Inhibitor CX5461
Authors: Prosser Kathleen E. , Leung Ada W. Y. , Harrypersad Shane , Lewis Andrew R. , Bally Marcel B. , Walsby Charles J.
Published: February 2018

Low aqueous solubility is a major barrier to the clinical application of otherwise promising drug candidates. We demonstrate that this issue can be resolved in medicinal molecules containing potential ligating groups, through the addition of labile transition‐metal ions. Incubation of the chemotherapeutic CX5461 with Cu2+ or Zn2+ enables solubilization at neutral pH but does not affect intrinsic cytotoxicity. Spectroscopic and computational studies demonstrate that this arises from coordination to the pyrazine functionality of CX5461 and may involve bidentate coordination at physiological pH.
Accurate pH Sensing using Hyperpolarized 129Xe NMR Spectroscopy
Authors: Léonce Estelle , Dognon Jean‐Pierre , Pitrat Delphine , Mulatier Jean‐Christophe , Brotin Thierry , Berthault Patrick
Published: February 2018

In the search for powerful non‐invasive methods for pH measurement, NMR usually suffers from biases, especially for heterogeneous samples or tissues. In this Communication, using the signals of hyperpolarized 129Xe encapsulated in a pair of water‐soluble cryptophanes, we show that a differential pH measurement can be achieved, free from most of these biases, by monitoring the difference between their chemical shifts.
An Expeditious Route to trans‐Configured Tetrahydrothiophenes Enabled by Fe(OTf)3‐Catalyzed [3+2] Cycloaddition of Donor–Acceptor Cyclopropanes with Thionoesters
Authors: Matsumoto Yohei , Nakatake Daiki , Yazaki Ryo , Ohshima Takashi
Published: February 2018

A synthetic route to trans‐configured tetrahydrothiophenes (THTs) through Fe(OTf)3‐promoted [3+2] cycloaddition of donor–acceptor cyclopropanes with thionoesters was developed. The cycloaddition proceeded in high yield with high diastereoselectivity, affording transient α‐alkoxy THTs. Not only aromatic and aliphatic thionoesters, but also thionolactone were applicable to the present iron catalysis. Further transformation of the S,O‐ketal functionality of the product was achieved in a highly trans diastereoselective manner. Moreover, the utility of our methodology was clearly demonstrated by the synthesis of enantioenriched trans‐configured THTs.
Moderne Zahnpflege aus chemischer Sicht
Authors: Epple Matthias , Enax Joachim
Published: February 2018

Die Mundgesundheit spielt in unserer Gesellschaft eine zentrale Rolle. Deshalb gibt es eine Vielzahl von wirkungsvollen Zahnpflegepräparaten, die die Mundgesundheit verbessern und Zahn‐ und Zahnfleischerkrankungen vorbeugen können. Neben der Zahnbürste (Handzahnbürste, elektrische Zahnbürste) ist dabei insbesondere die Zahnpasta von Bedeutung. Als zentraler Wirkstoff wird Fluorid angesehen, wobei es auch interessante Entwicklungen von biomimetischen Ansätzen auf der Basis von Calciumphosphat gibt.
Health equity for displaced children with cancer in the Middle East
Authors: Armenian Saro H.
Published: February 2018

Armed conflicts in the Middle East during the past decade have forced people to flee in vast numbers to neighboring countries, and this has added substantial strains to existing resources. In this context, the needs of displaced children with noncommunicable diseases such as cancer can unfortunately be overlooked because of the complexities of coordinating multidisciplinary care and a lack of resources for managing the acute toxicities of therapy. Innovative transnational collaborations in countries such as Lebanon can serve as models for the delivery of equitable cancer care during times of geopolitical turmoil.

See also pages 1464‐72.
Displaced children with cancer in Lebanon: A sustained response to an unprecedented crisis
Authors: Saab Raya , Jeha Sima , Khalifeh Haifaa , Zahreddine Lama , Bayram Layal , Merabi Zeina , Abboud Miguel , Muwakkit Samar , Tarek Nidale , Rodriguez‐Galindo Carlos , El Solh Hassan
Published: February 2018

BACKGROUND

The unrest in Syria has resulted in an escalating refugee crisis. The postwar lack of health care infrastructure in Iraq has also resulted in Iraqis seeking health care in neighboring countries. Pediatric cancer is largely curable, although its treatment is expensive and complex. Strategies to implement pediatric cancer care with curative intent in these vulnerable populations are lacking.

METHODS

To assess the feasibility of a collaborative approach for the provision of care to displaced children with cancer, this study reviewed the experience of the authors over the past 6 years in Lebanon, the country with the highest number of refugees per capita in the world.

RESULTS

The American University of Beirut Medical Center and the Children's Cancer Center of Lebanon Foundation, in partnership with St. Jude Children's Research Hospital and the American Lebanese Syrian Associated Charities, established 3 successive funding programs to treat displaced children with cancer along with a continuous assessment of resource utilization. Between 2011 and 2017, 575 non‐Lebanese children suspected to have cancer were evaluated. Of those, 311 received direct medical support, with 107 receiving full‐treatment coverage and 204 receiving limited‐workup/specialty services; the remaining 264 patients received medical consultations.

CONCLUSIONS

In addition to providing lifesaving humanitarian support, the coordination of care delivery, including the establishment of guidelines for prioritization, can help direct future efforts. Many patients continue to be in dire need of support, and this should be addressed via collaboration among governmental, nongovernmental, and health care organizations. Cancer 2018;124:1464‐72. © 2018 American Cancer Society.
Distorted weight perception correlates with disordered eating attitudes in Kuwaiti college women
Authors: Alkazemi Dalal , Zafar Tasleem A. , Ebrahim Mariam , Kubow Stan
Published: February 2018

Objective

We investigated the presence of disordered eating attitudes and weight perception among young women at body mass index (BMI) values that correspond to underweight, normal weight, overweight, and obese weight status.

Method

Data were collected from 1,147 female undergraduate students (89% Kuwaiti nationals) recruited from Kuwait University through employment of the eating attitude test (EAT‐26) together with an anonymous, self‐administered questionnaire to determine the prevalence of symptomatology indicative of anorexia nervosa and bulimia nervosa.

Results

The mean EAT‐26 scores differed significantly between the weight categories. More students with overweight and obesity scored above the established EAT‐26 cut off value indicating at risk of disordered eating compared to students who were at a normal weight or underweight (52.1% vs. 38.8%, respectively, X2(1) =16.1, p < .001). Logistic regression analyses showed significantly higher odds ratios (ORs) for the groups with overweight and obesity for dieting and bulimic behaviors, while women at normal and underweight had higher ORs for restrictive oral control behaviors associated with anorexia nervosa. Distorted weight perception was found in all weight categories.

Discussion

The high proportion of disordered eating attitudes among Kuwaiti college women could not be attributed to obesity alone as the type of disordered eating behavior varied more by weight perception than by weight status. The high levels of eating disorder related symptoms could be due to a combination of the social influences, diet, and lifestyle of college students. Such factors need to be considered by healthcare professionals as early as possible with more focused programs towards promotion of healthy weight for college students.
Variability and drivers of burn severity in the northwestern Canadian boreal forest
Authors: Whitman Ellen , Parisien Marc‐André , Thompson Dan K. , Hall Ronald J. , Skakun Robert S. , Flannigan Mike D.
Published: February 2018

Burn severity (ecological impacts of fire on vegetation and soils) influences post‐fire stand structure and species composition. The spatial pattern of burn severity may compound the ecological impacts of fire through distances to seed sources and availability of bud banks and seedbeds. Land managers require spatial burn severity data to manage post‐fire risks, ecosystem recovery, and assess the outcomes of fires. This research seeks to characterize and explain variability in burn severity in the northwestern boreal forest. We assessed burn severity one year post‐fire in six large wildfires that burned in 2014. We measured burn severity using the Composite Burn Index, surface Burn Severity Index, Canopy Fire Severity Index, and percent overstory mortality, describing a range of surface and overstory fire effects. Burn severity was variable, ranging from unburned residuals to complete overstory mortality and intense combustion. We related field measurements to remotely sensed multispectral burn severity metrics of the differenced Normalized Burn Ratio (dNBR), the Relativized dNBR, and the Relativized Burn Ratio. Diagnostic models of burn severity using relativized metrics had lower errors and better (though not significantly so) fits to the field data. Spatial patterns of burn severity were consistent with those observed in other large fires in North America. Stand‐replacing patches were large, aggregated, and covered the largest proportion of the landscape. These patterns were not consistent across the four mapped burn severity field metrics, suggesting such metrics may be viewed as related, but complementary, as they depict different aspects of severity. Prognostic models indicated burn severity was explained by pre‐fire stand structure and composition, topoedaphic context, and fire weather at time of burning. Wetlands burned less severely than uplands, and open stands with high basal areas experienced lower burn severity in upland vegetation communities. This research offers an enhanced understanding of the relationship between ground observations and remotely sensed severity metrics, in conjunction with stand‐level drivers of burn severity. The diverse fuel complexes and extreme fire weather during the 2014 fire season produced the complex patterns and broad range of burn severity observed.
Treatment with insulin is associated with worse outcome in patients with chronic heart failure and diabetes
Authors: Cosmi Franco , Shen Li , Magnoli Michela , Abraham William T. , Anand Inder S. , Cleland John G. , Cohn Jay N. , Cosmi Deborah , De Berardis Giorgia , Dickstein Kenneth , Franzosi Maria Grazia , Gullestad Lars , Jhund Pardeep S. , Kjekshus John , Køber Lars , Lepore Vito , Lucisano Giuseppe , Maggioni Aldo P. , Masson Serge , McMurray John J.V. , Nicolucci Antonio , Petrarolo Vito , Robusto Fabio , Staszewsky Lidia , Tavazzi Luigi , Teli Roberto , Tognoni Gianni , Wikstrand John , Latini Roberto
Published: February 2018

Aims

Up to one‐third of patients with diabetes mellitus and heart failure (HF) are treated with insulin. As insulin causes sodium retention and hypoglycaemia, its use might be associated with worse outcomes.

Methods and results

We examined two datasets: 24 012 patients with HF from four large randomized trials and an administrative database of 4 million individuals, 103 857 of whom with HF. In the former, survival was examined using Cox proportional hazards models adjusted for baseline variables and separately for propensity scores. Fine–Gray competing risk regression models were used to assess the risk of hospitalization for HF. For the latter, a case–control nested within a population‐based cohort study was conducted with propensity score. Prevalence of diabetes mellitus at study entry ranged from 25.5% to 29.5% across trials. Insulin alone or in combination with oral hypoglycaemic drugs was prescribed at randomization to 24.4% to 34.5% of the patients with diabetes. The rates of death from any cause and hospitalization for HF were higher in patients with vs. without diabetes, and highest of all in patients prescribed insulin [propensity score pooled hazard ratio for all‐cause mortality 1.27 (1.16–1.38), for HF hospitalization 1.23 (1.13–1.33)]. In the administrative registry, insulin prescription was associated with a higher risk of all‐cause death [odds ratio (OR) 2.02, 95% confidence interval (CI) 1.87–2.19] and rehospitalization for HF (OR 1.42, 95% CI 1.32–1.53).

Conclusions

Whether insulin use is associated with poor outcomes in HF should be investigated further with controlled trials, as should the possibility that there may be safer alternative glucose‐lowering treatments for patients with HF and type 2 diabetes mellitus.
Parents' Insights on Their Perceptions of and Their Children's Experiences in a College Access Program
Authors: Millett Catherine M. , Rojas Erick , Kevelson Marisol J. C.
Published: February 2018

This report summarizes the findings of focus groups conducted with parents of former and current participants in the Princeton University Preparatory Program (PUPP), a college access and preparation program for low‐income and high‐achieving students attending public high schools in Princeton, New Jersey, and its surrounding communities. Conducted as part of the evaluation of PUPP by Educational Testing Service, the parent focus groups provided insights into the perceptions parents have of PUPP, its impacts on their children, and their suggestions for programmatic improvements. Findings suggest that parents perceived that PUPP prepared their children for academically rigorous environments and supported the development of their social–emotional skills. Parents also praised PUPP's assistance with the college and financial aid application processes but noted that their children continued to face financial challenges despite receiving sizeable aid packages. Overall, parents would like to see PUPP expanded to serve more students in more public high schools.
A Preliminary Investigation of the Factors Related to the Design and Scoring of Video‐Based Oral Communication Performance Tasks in Higher Education
Authors: Roohr Katrina Crotts , Burkander Kri , Mao Liyang
Published: February 2018

Oral communication has been identified as an important skill by higher education institutions and by the workforce community. Despite its importance, minimal research has been conducted around the development of tasks to measure oral communication skills and behaviors. The purpose of this preliminary study is to evaluate the different factors related to the design and scoring of oral communication tasks. For this study, oral communication refers specifically to video‐based oral presentations using a webcam. The study administered 2 informative and 2 persuasive speech tasks of varying length (2 or 4 minutes) to 8 college students. Performance was scored holistically on overall performance, and on content and delivery dimensions by 2 raters. Results show that (a) interrater reliability estimates may be impacted by task type and length, (b) there is no variation in the three scoring criteria, (c) a minimum of 2 tasks is necessary to achieve satisfactory reliability on an oral communication measure, and (d) supporting materials may impact student performance. Results of this preliminary study provide guidance on how to further this foundational research. Future research and next steps are discussed.