bluuebunny/crossref_metadata_2025 huggingface dataset:
Durability of fiber‐reinforced polyoxymethylene composites under the high hydrostatic pressure in the deep sea
Authors: Liu Hao , Wang Jianzhang , Jiang Pengfei , Yan Fengyuan
Published: November 2019

The effect of hydrostatic pressure of up to 40 MPa on the seawater permeation, crystalline structure, and mechanical strength of carbon fiber and glass fiber‐reinforced polyoxymethylene (POM) composites was investigated. The experimental results reveal that hydrostatic pressure slightly promotes seawater permeation throughout the POM composites and degrades the bonding strength of the matrix–fiber interface. In the POM matrix, the seawater hydrostatic pressure does not influence the chemical stability but induces a physical chain scission process, which is characterized by linearly decreased molecular weight. The chain scissions initially entangled in the amorphous region are supposed to have sufficient mobility to join the crystalline phase. The increased crystallinity, albeit slight, together with the compress effect of hydrostatic pressure may possibly account for the stable mechanical strengths of the POM composites. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 137, 48686.
Improved gas transport properties of polyurethane–urea membranes through incorporating a cadmium‐based metal organic framework
Authors: Sadeghi Morteza , Isfahani Ali Pournaghshband , Shamsabadi Ahmad Arabi , Favakeh Sahar , Soroush Masoud
Published: November 2019

The increasing need for more efficient separation processes has motivated the development of polymer membranes that can provide fast and selective transport. In this work, cadmium‐based metal–organic framework (MOF) nanoparticles and a polyurethane–urea (PUU) elastomer were synthesized. New mixed‐matrix membranes (MMMs) were then fabricated from the nanoparticles and the PUU. SEM images verified that embedding the nanoparticles changes the morphology of the PUU and the nanoparticles disperse well in the PUU due to satisfactory compatibility of the polymer and nanoparticles. Fourier transform infrared spectroscopy and X‐ray diffraction analysis confirmed the dispersion of the nanoparticles in the soft segment of the PUU. With increased temperature, gas permeabilities of the MMMs improved but their sieving ability deteriorated. An MMM incorporating 2.5 wt % of the MOF showed a CO2permeability of ~140 barrer and a CO2/N2selectivity of ~30, which are 89 and 38% higher than those of the pristine membrane. Gas permeation tests showed that the higher CO2/N2selectivity of the MMMs was due to improved solubility selectivity and the higher CO2permeability was a result of improved CO2diffusivity and solubility coefficients. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2019,137, 48704.
A comparison of the beta‐geometric model with landmarking for dynamic prediction of time to pregnancy
Authors: van Eekelen Rik , Putter Hein , McLernon David J. , Eijkemans Marinus J. , van Geloven Nan
Published: November 2019

We conducted a simulation study to compare two methods that have been recently used in clinical literature for the dynamic prediction of time to pregnancy. The first is landmarking, a semi‐parametric method where predictions are updated as time progresses using the patient subset still at risk at that time point. The second is the beta‐geometric model that updates predictions over time from a parametric model estimated on all data and is specific to applications with a discrete time to event outcome. The beta‐geometric model introduces unobserved heterogeneity by modelling the chance of an event per discrete time unit according to a beta distribution. Due to selection of patients with lower chances as time progresses, the predicted probability of an event decreases over time. Both methods were recently used to develop models predicting the chance to conceive naturally. The advantages, disadvantages and accuracy of these two methods are unknown. We simulated time‐to‐pregnancy data according to different scenarios. We then compared the two methods by the following out‐of‐sample metrics: bias and root mean squared error in the average prediction, root mean squared error in individual predictions, Brier score and c statistic. We consider different scenarios including data‐generating mechanisms for which the models are misspecified. We applied the two methods on a clinical dataset comprising 4999 couples. Finally, we discuss the pros and cons of the two methods based on our results and present recommendations for use of either of the methods in different settings and (effective) sample sizes.
Study of thermoluminescence in turtle shell fossils using radiation dosimetry
Authors: Ovhal Digambar A. , Samant Bandana , Dhoble N.S. , Mohabey D.M. , Dhoble S.J.
Published: November 2019

The present study describes for the first time thermoluminescence (TL) characterization of turtle shell. A fossil shell was collected from the Dongargaon area in the Chandrapur district of Maharashtra, India. TL was recorded and a comparative study of TL for the above material was performed to understand the special TL characteristics of the shell. The shell was irradiated with 60Co γ‐radiation to study its TL properties. The sample displayed two good TL peaks at 135°C and 255°C. A linear dose–response curve for the irradiated sample was produced for the dose range 0.79–28.5 kGy; this sample of turtle shell (fossil) may be useful as a high dose dosimetry phosphor in this range. This geological sample was further characterized using X‐ray diffraction to confirm its phase structure and by scanning electron microscopy , Fourier transform infrared and wavelength dispersive X‐ray fluorescence spectroscopy to determine morphology, vibration, and elemental composition as ppm or percentage of the sample, respectively. Kinetic parameters of the TL glow peak were calculated using three different methods.
Does corporate environmental responsibility engagement affect firm value? The mediating role of corporate innovation
Authors: Li Zhenghui , Liao Gaoke , Albitar Khaldoon
Published: November 2019

This paper aims to construct a comprehensive corporate environmental responsibility (CER) engagement measurement to examine the relationship between CER engagement and firm value as well as explore the mediating effect of corporate innovation on this relationship based on a sample of 496 China's A‐share listed companies from 2008 to 2016. The results show that when firms start to adopt environmental regulations, CER would have a negative effect on firm value; however, at a specific level, CER would start to enhance firm value positively. In addition to this, corporate innovation plays a mediating role in the relationship between CER and firm value. Corporate innovation promotes firm value of firms with CER more than firms without CER. Overall, the findings of this paper are extremely relevant for the government, investors, and firm's managers and can be utilized for policy and investment decision making. Also, the findings encourage firms to enhance their sense of environmental responsibility in order to enhance their competitive advantages, enhance corporate innovation capabilities, and thus enhance firm value.
Heartech: Another parachute looking for a landing zone in interventions for heart failure
Authors: Kawabori Masashi , Kapur Navin K.
Published: November 2019

Key Points

Maladaptive left ventricular remodeling after acute myocardial infarction is defined by increased left ventricular dimensions and is associated with poor clinical outcomes.

Left ventricular partitioning devices mechanically reduce left ventricular dimensions and are postulated to improve symptomatic heart failure.

In this first in human study, deployment of the Heartech LVPD was shown to be feasible without a prohibitive safety signal precluding future pivotal trials.
Gradually closing the loop
Authors: Jerud Elliot S. , Gray William A.
Published: November 2019

Key Points

The Lariat device is an epicardial nonimplant suture delivery device capable of left atrial appendage closure.

The current study offers promising results but is limited by small sample size and multiple foundational issues with study design.

aMaze, a large multi‐center prospective randomized trial is currently underway and will provide additional insight into the safety of this device and its efficacy in maintenance of sinus rhythm after atrial fibrillation ablation.
Applying sinus node function testing to evaluate perioperative management for patients suffering from tachycardia‐bradycardia syndrome before atrial fibrillation ablation
Authors: Han Dan , She Jianqing , Sun Chaofeng , Li Hongbing
Published: November 2019

Sinus node (SN) function is an important prognostic factor of atrial fibrillation (AF). However, AF ablation guideline has not recommended SN function test before ablation. SN function testing before AF ablation in patients with tachycardia‐bradycardia syndrome should be beneficial to determine further therapy strategies and prognosis.
How much liver does a person need?
Authors: Harsch Igor Alexander
Published: November 2019

In patients who had no medical care for years, it is wise to expect the unexpected. Here, a gigantic liver cyst compressed abdominal organs, vessels, and the gut. The patient is thus far doing well in a nursing home, exemplifying the low amount of residual liver tissue necessary for survival.
Flexible Methane Production Using a Proportional Integral Controller with Simulation‐Based Soft Sensor
Authors: Raeyatdoost Niloofar , Eccleston Robin , Wolf Christian
Published: November 2019

Anaerobic digestion plants have the potential to produce biogas on demand to help balance renewable energy production and energy demand by consumers. A proportional integral (PI) controller is constructed and tuned with a novel tuning method to control biogas production in an optimal manner. In this approach, the proportional part of the controller is a function of the feeding rate and system's degree of stability. To estimate the degree of stability, a simulation‐based soft sensor is developed. By means of the PI controller, the requirement for gas storage capacity of the digester is reduced by approximately 30 % compared to a constant, continuous feeding regime of the digester.
Electrochemical Reduction of CO2: Effect of Convective CO2 Supply in Gas Diffusion Electrodes
Authors: Duarte Miguel , De Mot Bert , Hereijgers Jonas , Breugelmans Tom
Published: November 2019

The electrochemical reduction of carbon dioxide (CO2) is a promising technology in light of energy transition and industrial electrification. In this study, two different electrolyzer configurations, flow‐through and flow‐by modes, were analyzed for the production of carbon monoxide to resolve the CO2 mass‐transfer limitation problem at high current densities in gas diffusion electrodes. These two configurations respectively state convective and diffusive flow inside the gas diffusion layer, and their effect was studied on the cathodic performance of the electrolyzer by varying the operating conditions: cathodic potential, electrocatalyst loading, and Nafion content. In flow‐through configuration, a current density of 220 mA/cm2 could be achieved at a faradaic efficiency of 90 %; whereas, in the flow‐by configuration, the current density was at the same faradaic efficiency limited to 140 mA/cm2. However, the flow‐through configuration has a few limitations, such as lower energy efficiency, owing to the higher ohmic drop and the faster deactivation caused by crystallization of electrolyte salts inside the gas diffusion electrode. Therefore, flow‐by mode is currently the most adequate configuration for the long‐term operation of electrolyzers for the reduction of CO2 to CO. This study represents an essential step toward the application of electrolyzers for the electroreduction of CO2.
Electrochemical Behavior of Cytochrome C Immobilized in a Magnetically Induced Mesoporous Framework
Authors: Melo Antonio F. A. A. , Sedenho Graziela C. , Osica Izabela , Ariga Katsuhiko , Crespilho Frank N.
Published: November 2019

Invited for this month's cover picture is Prof. Crespilho's group (Bioelectrochemistry and Interfaces) from São Carlos Institute of Chemistry (IQSC/USP, Brazil). The cover picture shows molecules of redox protein cytochrome c immobilized on the metallic coating from magnetite nanoparticles decorated with near‐monodisperse gold nanoparticles, which are used as colloidal building blocks for the magnetic assembly of mesoporous framework. Read the full text of the Article at 10.1002/celc.201901047.
On Silylated Oxonium and Sulfonium Ions and Their Interaction with Weakly Coordinating Borate Anions
Authors: Bläsing Kevin , Labbow Rene , Michalik Dirk , Reiß Fabian , Schulz Axel , Villinger Alexander , Walker Svenja
Published: November 2019

Attempts have been made to prepare salts with the labile tris(trimethylsilyl)chalconium ions, [(Me3Si)3E]+ (E=O, S), by reacting [Me3Si‐H‐SiMe3][B(C6F5)4] and Me3Si[CB] (CB−=carborate=[CHB11H5Cl6]−, [CHB11Cl11]−) with Me3Si‐E‐SiMe3. In the reaction of Me3Si‐O‐SiMe3 with [Me3Si‐H‐SiMe3][B(C6F5)4], a ligand exchange was observed in the [Me3Si‐H‐SiMe3]+ cation leading to the surprising formation of the persilylated [(Me3Si)2(Me2(H)Si)O]+ oxonium ion in a formal [Me2(H)Si]+ instead of the desired [Me3Si]+ transfer reaction. In contrast, the expected homoleptic persilylated [(Me3Si)3S]+ ion was formed and isolated as [B(C6F5)4]− and [CB]− salt, when Me3Si‐S‐SiMe3 was treated with either [Me3Si‐H‐SiMe3][B(C6F5)4] or Me3Si[CB]. However, the addition of Me3Si[CB] to Me3Si‐O‐SiMe3 unexpectedly led to the release of Me4Si with simultaneous formation of a cyclic dioxonium dication of the type [Me3Si‐μO‐SiMe2]2[CB]2 in an anion‐mediated reaction. DFT studies on structure, bonding and thermodynamics of the [(Me3Si)3E]+ and [(Me3Si)2(Me2(H)Si)E]+ ion formation are presented as well as mechanistic investigations on the template‐driven transformation of the [(Me3Si)3E]+ ion into a cyclic dichalconium dication [Me3Si‐μE‐SiMe2]22+.
Shedding Light on the Interactions of Hydrocarbon Ester Substituents upon Formation of Dimeric Titanium(IV) Triscatecholates in DMSO Solution
Authors: Kwamen A. Carel N. , Schlottmann Marcel , Van Craen David , Isaak Elisabeth , Baums Julia , Shen Li , Massomi Ali , Räuber Christoph , Joseph Benjamin P. , Raabe Gerhard , Göb Christian , Oppel Iris M. , Puttreddy Rakesh , Ward Jas S. , Rissanen Kari , Fröhlich Roland , Albrecht Markus
Published: November 2019

The dissociation of hierarchically formed dimeric triple lithium bridged triscatecholate titanium(IV) helicates with hydrocarbyl esters as side groups is systematically investigated in DMSO. Primary alkyl, alkenyl, alkynyl as well as benzyl esters are studied in order to minimize steric effects close to the helicate core. The 1H NMR dimerization constants for the monomer–dimer equilibrium show some solvent dependent influence of the side chains on the dimer stability. In the dimer, the ability of the hydrocarbyl ester groups to aggregate minimizes their contacts with the solvent molecules. Due to this, most solvophobic alkyl groups show the highest dimerization tendency followed by alkenyls, alkynyls and finally benzyls. Furthermore, trends within the different groups of compounds can be observed. For example, the dimer is destabilized by internal double or triple bonds due to π–π repulsion. A strong indication for solvent supported London dispersion interaction between the ester side groups is found by observation of an even/odd alternation of dimerization constants within the series of n‐alkyls, n‐Ω‐alkenyls or n‐Ω‐alkynyls. This corresponds to the interaction of the parent hydrocarbons, as documented by an even/odd melting point alternation.
In Situ Generation of Ruthenium Carbonyl Phosphine Complexes as a Versatile Method for the Development of Enantioselective C−O Bond Arylation
Authors: Kondo Hikaru , Kochi Takuya , Kakiuchi Fumitoshi
Published: November 2019

We report here a method for in situ generation of various ruthenium carbonyl phosphine catalysts for arylation via cleavage of inert aromatic carbon–oxygen bonds. The use of catalyst systems consisting of [RuCl2(CO)(p‐cymene)], CsF, styrene, and phosphines enabled facile screening of phosphine ligands. Asymmetric C–O arylation was also achieved for atropo‐enantioselective biaryl synthesis using a chiral monodentate phosphine ligand.
Cycloaddition Reactions of an Active Cyclic Phosphane/Borane Pair with Alkenes, Alkynes, and Carbon Dioxide
Authors: Jie Xiaoming , Sun Qiu , Daniliuc Constantin G. , Knitsch Robert , Hansen Michael Ryan , Eckert Hellmut , Kehr Gerald , Erker Gerhard
Published: November 2019

The active six‐membered cyclo‐FLP6undergoes a rapid P/B addition reaction to carbon dioxide. At elevated temperature, the resulting heterobicyclo[2.2.2]octane derived product 7undergoes ring opening and equilibrates with the cyclotetramer(7)4. In the large macrocyclic structure, four monomeric six‐membered cyclo‐FLP units are connected by four CO2molecules to form the supramolecular ring system. The P/B cyclo‐FLP6undergoes a variety of additional cycloaddition reactions.
Some concerns regarding the CAT16 chromatic adaptation transform
Authors: Smet Kevin A. G. , Ma Shining
Published: November 2019

In recent literature, a new chromatic adaptation transform, CAT16, has been published to improve upon the widely used CAT02 model. The CAT16 model is based on the form of the CAT02 transform adopted in CIECAM02, but uses a slightly different sensor space to fix some gamut problems plaguing CIECAM02 and adopts a two‐step CAT to ensure symmetry and transitivity. CAT16 is included in CAM16 but is also being promoted as a stand‐alone CAT, one that can be used outside of the CAM16 model. However, the use of CAT16 as a stand‐alone model can cause inconsistencies in the calculated corresponding colors due to the presence of the relative luminance of the adapting white (Yw) in the von Kries‐Ives gain control factors. Such inconsistencies are not present for the stand‐alone version of the CAT02 model, which, unlike the version adopted in CIECAM02, does not include the Yw factors. CAT16 should therefore be modified by omitting the Yw factors. In this article, we will briefly discuss these issues in more detail and provide a consistent two‐step CAT adopting the CAT16 sensor space.
Theoretical Justification and Error Analysis for Slender Body Theory
Authors: Mori Yoichiro , Ohm Laurel , Spirn Daniel
Published: November 2019

Slender body theory facilitates computational simulations of thin fibers immersed in a viscous fluid by approximating each fiber using only the geometry of the fiber centerline curve and the line force density along it. However, it has been unclear how well slender body theory actually approximates Stokes flow about a thin but truly three‐dimensional fiber, in part due to the fact that simply prescribing data along a 1D curve does not result in a well‐posed boundary value problem for the Stokes equations in ℝ3. Here, we introduce a PDE problem to which slender body theory (SBT) provides an approximation, thereby placing SBT on firm theoretical footing. The slender body PDE is a new type of boundary value problem for Stokes flow where partial Dirichlet and partial Neumann conditions are specified everywhere along the fiber surface. Given only a 1D force density along a closed fiber, we show that the flow field exterior to the thin fiber is uniquely determined by imposing a fiber integrity condition: the surface velocity field on the fiber must be constant along cross sections orthogonal to the fiber centerline. Furthermore, a careful estimation of the residual, together with stability estimates provided by the PDE well‐posedness framework, allows us to establish error estimates between the slender body approximation and the exact solution to the above problem. The error is bounded by an expression proportional to the fiber radius (up to logarithmic corrections) under mild regularity assumptions on the 1D force density and fiber centerline geometry. © 2019 Wiley Periodicals, Inc.
Reversible Photoswitching of Isolated Ionic Hemiindigos with Visible Light
Authors: Carrascosa Eduardo , Petermayer Christian , Scholz Michael S. , Bull James N. , Dube Henry , Bieske Evan J.
Published: November 2019

Indigoid chromophores have emerged as versatile molecular photoswitches, offering efficient reversible photoisomerization upon exposure to visible light. Here we report synthesis of a new class of permanently charged hemiindigos (HIs) and characterization of photochemical properties in gas phase and solution. Gas‐phase studies, which involve exposing mobility‐selected ions in a tandem ion mobility mass spectrometer to tunable wavelength laser radiation, demonstrate that the isolated HI ions are photochromic and can be reversibly photoswitched between Z and E isomers. The Z and E isomers have distinct photoisomerization response spectra with maxima separated by 40–80 nm, consistent with theoretical predictions for their absorption spectra. Solvation of the HI molecules in acetonitrile displaces the absorption bands to lower energy. Together, gas‐phase action spectroscopy and solution NMR and UV/Vis absorption spectroscopy represent a powerful approach for studying the intrinsic photochemical properties of HI molecular switches.
Electrospun Cu‐Deposited Flexible Fibers as an Efficient Oxygen Evolution Reaction Electrocatalyst
Authors: Morinaga Asuka , Tsutsumi Hiromori , Katayama Yu
Published: November 2019

The front cover artwork is provided by the groups of Prof. Yu Katayama and Prof. Hiromori Tsutsumi at the Yamaguchi University, Japan. The image shows the unique microstructures of electrospun flexible fibers, coated with copper, designed as an efficient oxygen evolution reaction (OER) electrocatalyst. Read the full text of the Article at 10.1002/cphc.201900663.
Automated Data Cleanup for Mass Cytometry
Authors: Bagwell Charles Bruce , Inokuma Margaret , Hunsberger Benjamin , Herbert Donald , Bray Christopher , Hill Beth , Stelzer Gregory , Li Stephen , Kollipara Avinash , Ornatsky Olga , Baranov Vladimir
Published: November 2019

Mass cytometry is an emerging technology capable of 40 or more correlated measurements on a single cell. The complexity and volume of data generated by this platform have accelerated the creation of novel methods for high‐dimensional data analysis and visualization. A key step in any high‐level data analysis is the removal of unwanted events, a process often referred to as data cleanup. Data cleanup as applied to mass cytometry typically focuses on elimination of dead cells, debris, normalization beads, true aggregates, and coincident ion clouds from raw data. We describe a probability state modeling (PSM) method that automatically identifies and removes these elements, resulting in FCS files that contain mostly live and intact events. This approach not only leverages QC measurements such as DNA, live/dead, and event length but also four additional pulse‐processing parameters that are available on Fluidigm Helios™ and CyTOF® (Fluidigm, Markham, Canada) 2 instruments with software versions of 6.3 or higher. These extra Gaussian‐derived parameters are valuable for detecting well‐formed pulses and eliminating coincident positive ion clouds. The automated nature of this new routine avoids the subjectivity of other gating methods and results in unbiased elimination of unwanted events. © 2019 International Society for Advancement of Cytometry
Cross‐layer perspective for channel assignment in cognitive radio networks: A survey
Authors: Gupta Nitin , Dhurandher Sanjay Kumar
Published: November 2019

With the advent of various emerging wireless products, the usage of limited spectrum has grown exponentially in the recent years. In the next few years, that mobile data traffic globally is expected to grow up to 50 EB/month, which is nearly a five times increase over year 2018. Therefore, it will become extremely difficult to satisfy the ever increasing demand through the current fixed spectrum assignment policy in which spectrum band is exclusively used for the particular applications, and it has also led to underutilization of a significant portion of the spectrum (like TV bands). Cognitive radio networks has emerged as a possible solution for the problem which makes dynamic spectrum access possible for unlicensed user when licensed user is not active. Among various operations of cognitive radio, channel assignment to the unlicensed user is very important. Further, wireless regional area network is one of the most important application of cognitive radio, which provides wireless broadband to the rural area using vacant TV channels. This paper discusses channel assignment techniques considering various functionalities for cognitive radio networks in respect of wireless regional area network in the existing literature. Initially, a comprehensive introduction to both cognitive radio networks and wireless regional area networks is provided, and in the end, the paper summarizes the various issues and research challenges in the channel assignment for wireless regional area networks.
Evolution of sexually dimorphic pheromone profiles coincides with increased number of male‐specific chemosensory organs in Drosophila prolongata
Authors: Luo Yige , Zhang Yunwei , Farine Jean‐Pierre , Ferveur Jean‐François , Ramírez Santiago , Kopp Artyom
Published: November 2019

Binary communication systems that involve sex‐specific signaling and sex‐specific signal perception play a key role in sexual selection and in the evolution of sexually dimorphic traits. The driving forces and genetic changes underlying such traits can be investigated in systems where sex‐specific signaling and perception have emerged recently and show evidence of potential coevolution. A promising model is found in Drosophila prolongata, which exhibits a species‐specific increase in the number of male chemosensory bristles. We show that this transition coincides with recent evolutionary changes in cuticular hydrocarbon (CHC) profiles. Long‐chain CHCs that are sexually monomorphic in the closest relatives of D. prolongata (D. rhopaloa, D. carrolli, D. kurseongensis, and D. fuyamai) are strongly male‐biased in this species. We also identify an intraspecific female‐limited polymorphism, where some females have male‐like CHC profiles. Both the origin of sexually dimorphic CHC profiles and the female‐limited polymorphism in D. prolongata involve changes in the relative amounts of three mono‐alkene homologs, 9‐tricosene, 9‐pentacosene, and 9‐heptacosene, all of which share a common biosynthetic origin and point to a potentially simple genetic change underlying these traits. Our results suggest that pheromone synthesis may have coevolved with chemosensory perception and open the way for reconstructing the origin of sexual dimorphism in this communication system.
Pd‐Catalyzed Reductive Cyclization of Nitroarenes with CO2 as the CO Source
Authors: Guan Xinyu , Zhu Haoran , Zhao Yingwei , Driver Tom G.
Published: November 2019

A reductive amination process that constructs indoles, carbazoles or benzimidazoles from nitroarenes – irrespective of their electronic or steric nature – was developed that uses CO2 as the source of CO. The process is robust, tolerating common gaseous components of flue gas (H2S, SO2, NO and H2O) without adversely affecting the reductive cyclization.
Evaluation of heavy metal concentration in imported black tea in Iran and consumer risk assessments
Authors: Pourramezani Fatemeh , Akrami Mohajeri Fateme , Salmani Mohammad Hossein , Dehghani Tafti Arefe , Khalili Sadrabad Elham
Published: November 2019

Tea grows in the contaminated soils, absorbs the heavy metals, and enters them into the human food chain. The concentrations of Pb, Cd, Cu, As, and Hg of the imported black tea leaves to Hormozgan Province were evaluated by atomic absorption spectrometer. Then, the Hazard Quotient (HQ) and Hazard Index (HI) levels of heavy metal intakes were calculated to estimate the health hazard for consumers. The Pb, Cd, Cu, As, and Hg concentrations in the Sri Lankan and Indian blank tea were 0.14, 0.017, 11.29, 0.057, 0.0076 mg/kg, and 0.21, 0.02, 14.56, 0.067, 0.01 mg/kg, respectively. It was found that except for As concentration in Indian black tea were higher than Sri Lankan black tea. The HQ and HI levels of all studied metals were less than one, but they were higher in Indian black tea compared with the Sri Lankan black tea. The HI of Indian and Sri Lankan black tea samples were 0.061 and 0.048, respectively, which indicated no significant health hazard for tea consumers. The results showed that the consumption of the studied tea could not have any risk of heavy metal exposure.
Does trade size restriction affect trading behavior? Evidence from Indian single stock futures market
Authors: Banerjee Anirban , Banerjee Ashok
Published: November 2019

Algorithmic traders use their advantage of speed to execute a large number of small‐sized trades in a very short time. In the presence of a minimum trading unit (MTU) restriction, they are forced to trade at the smallest possible sizes, often restricted by the MTU. Using a novel data set of single stock futures market obtained from the National Stock Exchange of India, we show that the MTU restriction acts as a binding constraint for traders while optimizing trade sizes. Contrary to expectation, we find weak evidence that liquidity is positively impacted by the contract size revision.
Geochemistry and stable isotopes of the upper Campanian–lower Maastrichtian phosphorite‐bearing sequence, Central Jordan: Implications for their age, origin, and diagenesis
Authors: Ahmad Fayez , Baioumy Hassan , Farouk Sherif , Al‐Kahtany Khaled , El‐Sorogy Abdelbaset , Kirk Jason
Published: November 2019

Three major lithofacies have been described in Lajjun area, central Jordan, including the phosphorite and intercalated limestone of the Al‐Hisa Phosphorite Formation, as well as the Muwaqqar Chalk Marl Formation. 87Sr/86Sr isotopic data indicate a late Campanian age for the Al‐Hisa Phosphorite Formation, whereas the overlying chalk of the Muwaqqar Formation contains the lowest Maastrichtian planktic foraminiferal zone of Rugoglobigerina hexacamerata (CF8b).

The phosphorites are of reworked origin as inferred from the homogeneous texture with lack of any concentric structure in the phosphatic pellets and the presence of bone fragments inside the phosphatic pellets, which are filled with phosphatic mud similar to the matrix of phosphatic pellet. They still reflect the original seawater rare‐earth pattern, as indicated from the similarity in their rare‐earth element (REE) concentration and patterns with seawater. Positive correlations between P2O5 and Fe2O3, TiO2 and K2O, relatively high rare‐earth contents, and similarity in (Nd/Yb)SN ratio to the modern shallow seawater suggest a continental marginal depositional environment for the limestone and chalk facies. δ13C values are lower and more variable compared with the estimated global range of upper Campanian–lower Maastrichtian δ13C values in shelf and oceanic basins. This indicates a diagenetic effect on the δ13C isotopes and suggests that a significant proportion of carbonate ions could have been resulted from the organic carbon oxidation. Three third‐order depositional sequences matching with the global and regional sea‐level patterns are identified in the studied section based on vertical facies changes. The basal transgressive surface of each sequence is constantly characterized by a phosphatic horizon.
Psychological predictors of memory decline in a racially and ethnically diverse longitudinal sample of older adults in the United States
Authors: Sol Ketlyne , Zaheed Afsara B. , Kraal A. Zarina , Sharifian Neika , Arce Rentería Miguel , Zahodne Laura B.
Published: November 2019

Objectives

In the United States, racial and ethnic disparities in memory dysfunction and Alzheimer disease are evident even after accounting for many risk factors. Psychological factors, such as psychological well‐being, perceived control, depressive symptoms, and negative affect, may influence memory dysfunction, and associations may differ by race and ethnicity. This study examined whether psychological factors are differentially associated with episodic memory trajectories across racial and ethnic groups in the United States.

Methods/Design

The National Health and Aging Trends Study (NHATS), is a US‐representative, longitudinal study of Medicare‐eligible adults 65+ years old. Analyses of 5 years of data, included a total of 9411 participants without dementia at baseline. Adjusting for relevant covariates, a linear mixed model estimated the associations between psychological predictors and a composite of immediate and delayed trials from a word list memory test.

Results

More depressive symptoms (B = −0.02), lower psychological well‐being (B = 0.03), and lower perceived control (B = 0.05) were independently associated with lower initial memory. Depressive symptoms were associated with faster rate of memory decline (B = −0.01). Black (B = −0.34) and Hispanic (B = −0.28) participants evidenced lower initial memory level than whites, but only Hispanic (B = −0.04) participants evidenced faster memory decline than whites. There were no significant interactions between the psychological variables and race and ethnicity.

Conclusions

Results extend previous studies showing racial and ethnic disparities in episodic memory trajectories, and the longitudinal effects of depressive symptoms on episodic memory in US samples. Epidemiological studies of cognitive aging should incorporate more psychological factors clarify cognitive decline and disparities.
The three dimensions of caregiver grief in dementia caregiving: Validity and utility of the subscales of the Marwit‐Meuser Caregiver Grief Inventory
Authors: Chan Ivana , Yap Philip , Wee Shiou Liang , Liew Tau Ming
Published: November 2019

Background

The experience of grief in family caregivers as they provide care for persons with dementia is often overlooked. The Marwit‐Meuser Caregiver Grief Inventory (MM‐CGI) is one among the few scales that capture such experiences. In a recent study, MM‐CGI was found to contain three subscales identifying dimensions of loss in caregivers—Personal‐Sacrifice Burden (PSB), Heartfelt Sadness, Longing, and Worry (HSLW), and Felt Isolation (FI). We aimed to evaluate the validity and utility of these dimensions in a multiethnic Asian population.

Methods

Family caregivers (n = 394) completed MM‐CGI and scales assessing caregiver burden, depression, and gains. Internal consistency reliability was examined using Cronbach α; test‐retest reliability using intraclass correlation coefficient; and construct validity using Pearson correlation coefficient. The utility of the MM‐CGI dimensions was evaluated by comparing caregivers with high subscale scores across dementia stages and caregiving relationship.

Results

The three dimensions of MM‐CGI exhibited adequate internal consistency, test‐retest reliability, construct validity, and known‐group validity. PSB correlated most strongly with caregiver burden (r = 0.78); HSLW with caregiver depression (r = 0.75); and FI with caregiver burden and caregiver depression (r = 0.60, respectively). Caregivers with high total grief scores tended to experience most difficulty with HSLW (90.8%), followed by PSB (75.4%) and FI (46.2%). The three dimensions also increased across the dementia stages, with FI higher in mild dementia, PSB higher in moderate dementia, and HSLW higher in severe dementia. Spousal caregivers experienced most difficulty in HSLW, whereas children caregivers experienced similar levels of difficulty across the dimensions.

Conclusions

The three dimensions of MM‐CGI captured distinct aspects of caregiver grief in a multiethnic Asian population and would enable more individualized assessments and interventions for caregiver grief.
Multivariate models of brain volume for identification of children and adolescents with fetal alcohol spectrum disorder
Authors: Little Graham , Beaulieu Christian
Published: November 2019

Magnetic resonance imaging (MRI) studies of fetal alcohol spectrum disorder (FASD) have shown reductions of brain volume associated with prenatal exposure to alcohol. Previous studies consider regional brain volumes independently but ignore potential relationships across numerous structures. This study aims to (a) identify a multivariate model based on regional brain volume that discriminates children/adolescents with FASD versus healthy controls, and (b) determine if FASD classification performance can be increased by building classification models separately for each sex. Three‐dimensional T1‐weighted MRI from two independent childhood/adolescent datasets were used for training (79 FASD, aged 5.7–18.9 years, 35 males; 81 controls, aged 5.8–18.5 years, 32 males) and testing (67 FASD, aged 6.0–19.6 years, 38 males; 74 controls, aged 5.2–19.5 years, 42 males) a classification model. Using FreeSurfer, 87 regional brain volumes were extracted for each subject and were used as input into a support vector machine generating a classification model from the training data. The model performed moderately well on the test data with accuracy 77%, sensitivity 64%, and specificity 88%. Regions that contributed heavily to prediction in this model included temporal lobe and subcortical gray matter. Further investigation of two separate models for males and females showed slightly decreased accuracy compared to the model including all subjects (male accuracy 70%; female accuracy 67%), but had different regional contributions suggesting sex differences. This work demonstrates the potential of multivariate analysis of brain volumes for discriminating children/adolescents with FASD and provides indication of the most affected regions.
An assessment of management competencies for primary health care managers in Timor‐Leste
Authors: Lopes Alipio Gusmão , Narattharaksa Kanida , Siripornpibul Taweesak , Briggs David
Published: November 2019

Background

This study aims to assess the levels of management competencies of primary health care (PHC) managers in Timor‐Leste. Timor‐Leste is a young country. It has made important improvements in reconstructing its health system since its independence in 2002. However, most managers still learn through their failures, and few studies have described the perceptions of managers in Timor‐Leste.

Methods

This study used quantitative methods, using a cross‐sectional survey involving a structured self‐administered questionnaire. The Cochran formula was used in calculating the sample size. The sample included 183 PHC managers in Timor‐Leste. Stratified random sampling was adopted to conduct the survey. The researcher used confirmatory factor analysis (CFA) to confirm the validity and reliability of the tools and create new dimensions. The data were analyzed using the frequency and percentage.

Results

This study was initially designed to include seven dimensions, but after confirming it using the CFA, it was reduced to six dimensions. The result of CFA was used. This study found that PHC managers in Timor‐Leste had rated themselves “not competent” in knowing the organization, professionalism in the workplace, problem solving on financial management, and effective leadership and only “competent” in managing human resources and communicating effectively.

Conclusion

This study determined that policy makers and stakeholders must give more attention to knowing the organization, professionalism in the workplace, problem solving on financial management, and effective leadership. Managers need to be competent and have various skills to perform managerial functions effectively and efficiently.
Prices, availability, and affordability of national essential medicines in public primary hospitals: A cross‐sectional survey in poverty‐stricken rural areas in China
Authors: Xu Rixiang , Li Shuting , Lv Xiongwen , Xie Xuefeng
Published: November 2019

Introduction

This study aimed to determine the prices, availability, and affordability of national essential medicines in public primary hospitals in poverty‐stricken areas of Anhui province, China.

Methods

A cross‐sectional study was conducted in 143 public primary hospitals in Anhui province, eastern China. Data on access to 44 essential medicines was evaluated using the standardized methodology available in the World Health Organization and Health Action International manual.

Results

Median price rates show that 46.51% (21 of 44) of the lowest price generics and 100% of the originator brands were more expensive than the international reference price. The median availability of the 44 medicines was 31.47%, and 65.91% (29 of 44) of the medicines had less than 50% availability. The majority of the medicines were affordable as they would cost less than a day's income in sample areas. Suppliers could respond to 88.27% of the procuring orders raised by the 143 hospitals in the study, but this ranged from 43.96% to 99.86%.

Conclusions

There is poor availability and non‐ideal response rate of medicine delivery in public primary hospitals in poverty‐stricken areas in eastern China. Further implementation of national essential medicine policy needs to focus on improving both availability and distribution efficiency in these areas.
Medical and socio‐demographic characteristics associated with patient‐perceived continuity of primary care: A cross‐sectional survey in Hangzhou, China
Authors: Zhang Tao , Ren Jianping , Zhang Xinyu , Max Wendy
Published: November 2019

Background

This study measured the perceived continuity of general practitioner (GP) care from the patient's perspective and identified the associated factors.

Methods

A cross‐sectional survey was carried out on 624 patients in community health care centres in Hangzhou, China. A self‐designed Likert scale was used to measure patients' perceptions on informational, managerial, and relational continuity of GP care. An average score for three types of continuity ranging from 0 to 100 was calculated. Linear regression models were developed to determine the factors influencing continuity.

Results

Average rating scores of 57.73 (±15.31), 50.74 (±17.18), 61.61 (±18.07), and 63.57 (±17.40) were found for total, informational, managerial, and relational continuity of care, respectively. Older patients reported a more positive rating on all types of continuity. Income was negatively associated with managerial continuity. The factors affecting informational, relational, and total continuities included chronic diseases, walking distance to nearest community health centres, signing a contract with a GP, and knowing the names of contracted GPs.

Conclusion

Patients' perception of continuity of GP care remains at a low level, especially for informational continuity. The varied association between continuity of care and identified factors suggests that targeted actions should be considered for improving the quality of GP services.
The untenable omission of touch in maternal sensitivity and attachment research
Authors: Botero Maria , Langley Hillary A. , Venta Amanda
Published: November 2019

Despite an increase in research examining maternal and infant touch, and documenting its public health impact, this mode of interaction has historically been omitted from related fields of developmental research in human and non‐human primates. The broad aim of this review is to examine to what extent mother–infant touch has been included in relational paradigms and research. We argue that although theoretical and empirical scholarship on attachment and maternal sensitivity conceptualizes touch as fundamental to caregiver–infant interactions and child development more broadly, touch is rarely operationalized or measured in caregiver–infant interaction paradigms or clinical interventions. Data from primarily human, but also non‐human, primates are reviewed to document the importance of touch, and clinical research is reviewed to document the formal use of touch in human attachment and sensitivity research and intervention. The review closes with recommended directions for future research and related implications.

Highlights

Review examining to what extent mother–infant touch has been included in relational paradigms and research across human and non‐human primates.

Data from studies in human attachment, sensitivity research and intervention, and mother–infant interaction in non‐human primates are reviewed.

Touch is theoretically essential, but practically excluded, from attachment coding, maternal sensitivity research, and intervention paradigms. Recommended directions for future research are provided.
Fatty Acid Triangulation in Albumins Using a Landmark Spin Label
Authors: Reichenwallner Jörg , Hauenschild Till , Schmelzer Christian E. H. , Hülsmann Miriam , Godt Adelheid , Hinderberger Dariush
Published: November 2019

Several spatial correlations of up to six fatty acid (FA) binding sites in albumins were found by double electron‐electron resonance (DEER). A strategy was used that combines spin‐labeling and spin‐probing techniques in electron paramagnetic resonance (EPR) spectroscopy. This is here achieved by introducing an additional covalent landmark spin (LS) label to the self‐assembled system of EPR‐active, paramagnetic stearic acid derivatives and albumins. Therefore, a cysteine specific, paramagnetic LS that was attached to the albumin surface at a unique position (Cys34) provides a fixed topological reference point for monitoring statistical ligand uptake. We propose that the determination of nanoscale distance distributions emerging between the LS and EPR‐active fatty acid derivatives generally allows for the direct observation of individually occupied binding sites in solution. Essentially, several binding pockets, groups of them and evidence for ligand‐induced allosteric modulation can be traced from such FA‐LS interspin correlations. Experimental results were substantiated with theoretical predictions from molecular dynamics (MD) simulations. It was observed that all binding sites in an albumin ensemble may be statistically filled even at the lowest level of ligand loading. This approach generally bears the potential for mapping occupation states of individual ligand binding sites in proteins using such spin‐labeled ligands.
Randomized double‐blind placebo‐controlled trial of the effect of Morus nigra L. (black mulberry) leaf powder on symptoms and quality of life among climacteric women
Authors: Costa Joyce P.L. , Brito Haissa O. , Galvão‐Moreira Leonardo V. , Brito Luiz G.O. , Costa‐Paiva Lucia , Brito Luciane M.O.
Published: November 2019

Objective

To test the efficacy of Morus nigra L. (MN) leaf powder for treating climacteric symptoms by comparison with hormone therapy (HT) and placebo.

Methods

A randomized controlled trial among 62 climacteric women attending Hospital of the Federal University of Maranhão, Brazil. Women were divided into MN, HT, and placebo groups, and received 250 mg of MN leaf powder, 1 mg of estradiol, or placebo for 60 days. Primary outcomes were the Blatt–Kupperman index (BKI) for climacteric symptoms and SF‐36 health questionnaire scores.

Results

Baseline sociodemographic variables, BKI scores, symptoms, and SF‐36 domains did not differ among the groups. There was a reduction in mean BKI in the MN (17.5 vs 9.7, P<0.001), HT (15.4 vs 8.6, P=0.001), and placebo (16.1 vs 12.4, P=0.040) groups. Analysis of quality of life (QoL) showed that functional capacity (P=0.006), vitality (P=0.031), mental health (P=0.017), and social aspect (P<0.01) improved after treatment in the MN group. The HT group showed improvement in emotional limitation (P=0.040), and the placebo group showed better functional capacity (P=0.030) after treatment.

Conclusions

Climacteric symptoms and QoL improved after administration of 250 mg of MN leaf powder for 60 days, similar to the effects of HT.

The trial is registered in the Brazilian Registry of Clinical Trials (REBEC) under registration number RBR‐9t4xxk.