bluuebunny/crossref_metadata_2025 huggingface dataset:
Protracted precarities: The residential mobilities of Poles in Scotland
Authors: McCollum David , Trevena Paulina
Published: February 2021

The significant inflow of migrants to the United Kingdom following the Eastern EU Enlargement of 2004 is noteworthy due to its scale, intensity and geographic diversity. Recent statistical data suggest that these migrants exhibit spatial mobilities that reflect their disadvantage not just from the White British but also from other minority groups. Drawing on 83 interviews with Polish migrants living in Scotland, this paper illustrates the often‐persistent residential relocations experienced by this group postinternational migration and considers the drivers behind them. A key driver of this is the cycle of low paid and insecure employment that many migrants become entangled in, most frequently on arrival but often also longer term. These insights speak to wider debates about the scholarly dichotomy between international and internal migration and social inequalities in relation to labour market change and associated exposure to labour market and residential precarities.
Physiologically‐based pharmacokinetic modeling to support bioequivalence and approval of generic products: A case for diclofenac sodium topical gel, 1%
Authors: Tsakalozou Eleftheria , Babiskin Andrew , Zhao Liang
Published: February 2021

Establishing bioequivalence (BE) for dermatological drug products by conducting comparative clinical end point studies can be costly and the studies may not be sufficiently sensitive to detect certain formulation differences. Quantitative methods and modeling, such as physiologically‐based pharmacokinetic (PBPK) modeling, can support alternative BE approaches with reduced or no human testing. To enable PBPK modeling for regulatory decision making, models should be sufficiently verified and validated (V&V) for the intended purpose. This report illustrates the US Food and Drug Administration (FDA) approval of a generic diclofenac sodium topical gel that was based on a totality of evidence, including qualitative and quantitative sameness and physical and structural similarity to the reference product, an in vivo BE study with PK end points, and, more importantly, for the purposes of this report, a virtual BE assessment leveraging dermal PBPK modeling and simulation instead of a comparative clinical end point study in patients. The modeling approach characterized the relationship between systemic (plasma) and local (skin and synovial fluid) diclofenac exposure and demonstrated BE between the generic and reference products at the presumed site of action. Based on the fit‐for‐purpose modeling principle, the V&V process involved assessing observed data of diclofenac concentrations in skin tissues and plasma, and the overall performance of the modeling platform for relevant products. Using this case as an example, this report provides current scientific considerations on good practices for model V&V and the establishment of BE for dermatological drug products when leveraging PBPK modeling and simulation for regulatory decision making.
An Explanation for High Defect Tolerance in Metal Halide Perovskite Quantum Dots
Authors: Cui Yu , Liu Xiao-Yi , Deng Jia-Pei , Li Zhi-Qing , Wang Zi-Wu
Published: February 2021

An Auger‐like process assisted by quantum defects in metal halide perovskite quantum dots is proposed, where a charge carrier in the ground state of the quantum dot is trapped by quantum defects, resulting in a charge carrier defect being excited simultaneously and returning to the ground state of the quantum dot. It is found that the lifetime of the whole process varies from femtosecond to picosecond, depending on the radius of the quantum dot and the depth of the defect within the bandgap. Moreover, the lifetime is independent of the species of the defects, which is in good agreement with the recent theoretical prediction using ab initio non‐adiabatic molecular dynamics simulation. This Auger‐like process may provide a potential explanation of the high defect tolerance in metal halide perovskite materials.
Oral application of Chinese herbal medicine for allergic rhinitis: A systematic review and meta‐analysis of randomized controlled trials
Authors: Li Hong , Kreiner Jenny Manuela , Wong Ann Rann , Li Mingdi , Sun Yue , Lu Leyao , Liu Jianping , Yang Angela Wei Hong
Published: February 2021

Chinese herbal medicine (CHM) has long been used for allergic rhinitis (AR). This systematic review aimed to investigate the clinical effects and safety of oral CHM for AR by comparing it to Western medications (WM). Nineteen databases were searched up to May 27, 2020. Randomized controlled trials (RCTs) assessing the effects of CHM on the primary or secondary outcomes comparing to WM, in any age of the patients, were included. The pooled results were expressed as mean difference, standardized mean difference, or odds ratio with 95% confidence intervals. Eighteen RCTs were included and 17 of them were evaluated in the meta‐analysis. CHM may improve total nasal symptom scores, individual symptom scores (rhinorrhea, nasal congestion, sneezing, and nasal itching), quality of life, and recurrence rate, compared to antihistamines (loratadine and chlorpheniramine). Only mild and transient adverse events of CHM were reported. However, there were no significant differences in some subgroup analyses in total nasal symptom scores, rhinorrhea, nasal obstruction, sneezing, nasal itching, and SF‐36. Due to the small number of included studies, poor quality of trial design, and substantial heterogeneities, the potential of CHM for AR should be validated in large, multicenter, and well‐designed RCTs in the future.
Improving the water barrier properties of alginate packaging films by submicron coating with drying linseed oil
Authors: Nehchiri Narges , Amiri Sedigheh , Radi Mohsen
Published: February 2021

Alginates with excellent film‐forming ability have a promising potential as a safe and biodegradable food packaging material, but as a hydrophilic biopolymer, its general weakness against water has limited its applications. To surpass this weakness, in this study, coating of calcium alginate films with linseed or sunflower oils in micrometric (about 4.55 μm) and submicrometric (about 0.45 μm) thickness was performed, and the characteristics of the films were evaluated. All of the films were homogeneous, transparent and almost colourless. Micro‐coated films presented improved ultraviolet absorbing spectra. The scanning electron microscopy (SEM) images proved the formation of homogeneous and continuous submicron‐coated oil layers for both types of the oils, while some inhomogeneity and defects were observed in the micro‐coated films. Oxidative polymerization of linseed oil was confirmed by Fourier transform infrared (FTIR) spectral analyses. The mechanical strength of the films micro‐coated with linseed oil increased. Submicron coating improved water vapour barrier properties (from 2.20 to 2.92 g/mm/m2/day/kPa) as well as water vapour absorption of the alginate film compared to other films. This result was confirmed by thermogravimetric analyses. The increase in surface hydrophobicity of the films by coating resulted in a significant increase in contact angle (from 46.3° to 89.9° in maximum) and reduction of wettability. The film submicron coated with linseed oil showed the best performance with the least water vapour permeability, water vapour absorption and wettability.
Pneumonia risk in patients receiving clozapine
Authors: Lam Y. W. Francis
Published: February 2021

Clozapine is highly effective in the treatment of drug‐resistant schizophrenia, but its use can be associated with significant side effects, including agranulocytosis. Adverse cardiopulmonary effects, including tachycardia, orthostatic hypotension, and pneumonia, have also been reported. According to one study, the occurrence of pneumonia was much higher within 30 days of receiving clozapine.
Quality control using S2 or S charts for subgroups of varying sample sizes and their exact average run lengths
Authors: Maghsoodloo Saeed , Shirzaei Samira
Published: February 2021

This article generalizes the historical chart (of equal sample sizes) to subgroups of differing sample sizes. As a sequel to a previous article, Section 2 compares all estimators of process standard deviation for more than 1 subgroups of equal sample sizes from a normal universe. Section 3 provides the general probability control limits (CONLs) for the chart of unequal sample sizes. Section 4 uses the chi‐square distribution to obtain the exact ‐level CONLs for the S chart. Section 5 proves that the average run length (ARL) of and charts are identical and tabulates the ARL for the most common sample sizes = 2, 3, , and 12. Further, as expected, the ARL of charts always perform better than those of the corresponding charts.
The extended homogeneously weighted moving average control chart
Authors: Alevizakos Vasileios , Chatterjee Kashinath , Koukouvinos Christos
Published: February 2021

Control charts are widely applied in many manufacturing processes to monitor the quality characteristic of interest. Recently, a homogeneously weighted moving average (HWMA) control chart was proposed as an improvement of the exponentially weighted moving average (EWMA) chart for efficiently monitoring of small shifts in the process mean. In the present article, we extend the HWMA chart by imitating exactly the double EWMA (DEWMA) technique. The proposed scheme is regarded as double HWMA (DHWMA) control chart. The run‐length characteristics of the proposed chart are evaluated by performing Monte Carlo simulations. A comparison study versus the EWMA, DEWMA, HWMA, mixed EWMA cumulative sum (CUSUM), CUSUM, and GWMA charts indicates that the DHWMA chart is more effective in detecting small to moderate shifts, while it performs similarly with its competitors for large shifts. We also study the robustness of the proposed chart under several nonnormal distributions, and it is shown that the DHWMA chart is in‐control robust for small values of the smoothing parameters. Finally, two examples are given to demonstrate the implementation of the proposed chart.
The effects of constructed bivariate copulas on multivariate control charts effectiveness
Authors: Sukparungsee Saowanit , Sasiwannapong Sirasak , Busababodhin Piyapatr , Areepong Yupaporn
Published: February 2021

The average control chart monitors the shifts in the process. The familiar multivariate control charts are used to detect the mean vector of the process such as multivariate cumulative sum (MCUSUM) and Hotelling's T2 control charts. In this paper, the effects of constructing bivariate copulas on multivariate control charts, that is, MCUSUM and Hotelling's T2 control charts are intensively investigated when observations are drawn from the exponential distribution. Moreover, the dependence levels of observations are classified to be weak, moderate, and strong in both positive and negative values by Kendall's tau. The numerical results were obtained by Monte Carlo simulation to explore the average run length (ARL). The simulation results show that the performance of Hotelling's T2 control chart is superior to the MCUSUM control chart for all shifts in the mean vector of process. Furthermore, from applying the presented control chart to two sets of real data, data set of the strength of 1.5 cm glass fibers measured at the National Physical Laboratory, England and data set of the strength of glass of the aircraft window, it was found that for a small shift (), the MCUSUM control chart is better than Hotelling's T2 control chart.
Adsorption of organic molecules on graphene and fluorographene: An unresolved discrepancy between experiment and theory
Authors: Iribarne Federico , Denis Pablo A.
Published: February 2021

Herein, we studied the adsorption of 15 organic and three polar molecules onto pristine and fluorinated graphene. Two levels of fluorination were selected, CF fluorographene for which all carbon atoms are fluorinated and C4F fluorinated graphene, which maximizes the number of Clar sextets. Five different density functionals were employed: M06‐L, M06‐2X, PBE‐D2 and PBE‐D3BJ. In contrast with recent experimental investigations, we found that the adsorption energies for organic molecules onto perfect graphene are significantly lower than those determined for fluorographene. This situation is exacerbated when enthalpic and free energy corrections are included. However, a different scenario was found for polar molecules such as H2O, H2O2 and HF. Partial fluorination following a C4F pattern leads to significantly lower adsorption energies for these three molecules, and the superhydrophilicity of C4F is maintained after thermodynamic corrections are included. In fact, even the removal of a single fluorine atom results in a dramatic change in the adsorption energy of water on fluorographene. We discuss the performance of the density functionals assayed and the importance of using finite and infinite models. This work demonstrates that it is possible to adjust the adsorption energy of a given polar molecule onto graphene by controlling the fluorination level and in doing so, that partially fluorinated graphene models may open new avenues for the separation of molecules with different polarity.
Splitting dioxygen over distant binuclear transition metal cationic sites in zeolites. Effect of the transition metal cation
Authors: Dedecek Jiri , Tabor Edyta , Andrikopoulos Prokopis C. , Sklenak Stepan
Published: February 2021

Splitting dioxygen to yield highly active oxygen species attracts enormous attention due to its potential in direct oxidation reactions, mainly in transformation of methane into valuable products. Distant binuclear cationic Fe(II) centers in Fe‐ferrierite have recently been shown to be active in splitting dioxygen at room temperature to form very active oxygen species able to oxidize methane to methanol at room temperature as well. Computational models of the distant binuclear transition metal cationic sites (Co(II), Mn(II), and Fe(II)) stabilized in the ferrierite matrix were investigated by periodic density‐functional theory calculations including molecular dynamics simulations. The results reveal that the M(II) cations capable of the M(II) → M(IV) redox cycle with the M…M distance of ca 7.4 Å stabilized in two adjacent β sites of ferrierite can split dioxygen. Our study opens the possibility of developing tunable zeolite‐based systems for the activation of dioxygen employed for direct oxidations.
Remotely piloted aircraft systems remote sensing can effectively retrieve ecosystem traits of alpine grasslands on the Tibetan Plateau at a landscape scale
Authors: Tang Ze , Zhang Yangjian , Cong Nan , Wang Li , Zhu Yixuan , Li Zhaolei , Zhao Guang
Published: February 2021

Ecosystem trait is a standardized description of biological features of a community, and it bridges individual plants and ecosystem. Conventionally most ecosystem trait data are collected from field survey and the generated data is hard to meet the requirements as set in the concept of ecosystem trait. To a great extent, remotely piloted aircraft systems (RPAS) remote sensing, which is capable of retrieving ecosystem traits across multiple scales, can overcome constraints in field plot survey. In this study, we selected alpine grassland ecosystem on the Tibetan Plateau (TP), which is under‐studied due to scarcity of field monitoring data, as the research target. A new data framework was proposed by integrating field plot and RPAS remote sensing data to map spatial patterns of ecosystem traits for the alpine grasslands. Across four landscapes on the TP, ecosystem traits of vegetation coverage (CVC), species number (CSN), individual number (CIN), above ground biomass (AGB), organic carbon content (OC%) and total nitrogen content (TN%) were retrieved. We also calculated Shannon's Diversity Index and Shannon's Evenness Index for each plot. The results showed that RPAS‐based high spatial resolution RGB image is capable of predicting both physical and chemical ecosystem traits for alpine grasslands on the TP. Remote sensing on physical traits are overall more efficient than on chemical traits, with the highest R2 of 0.86 and 0.48 for physical trait and chemical one, respectively. The bands of Red and Green contributed more to the prediction model than band of Blue did, and the spectral mean value played a greater role than the spectral standard deviation. Based on the retrieved results, a set of spatial patterns on ecosystem traits can be revealed. This study represents an advance on ecosystem trait study and can significantly improve our understanding on ecosystem functions of the alpine ecosystem on the TP.
5G satellite networks for Internet of Things: Offloading and backhauling
Authors: Soret Beatriz , Leyva‐Mayorga Israel , Cioni Stefano , Popovski Petar
Published: February 2021

One of the main drivers of 5G cellular networks is provision of connectivity service for various Internet of Things (IoT) devices. Considering the potential volume of IoT devices at a global scale, the next leap is to integrate Non‐Terrestrial Networks (NTN) into 5G terrestrial systems, thereby extending the coverage and complementing the terrestrial service. This paper focuses on the use of low‐Earth orbit (LEO) satellite constellations for two specific purposes: offloading and backhauling. The former allows offloading IoT traffic from a congested terrestrial network, usually in a very dense area. In the latter application, the constellation provides a multi‐hop backhaul that connects a remote terrestrial Next Generation NodeB (gNB) to the 5G core network. After providing an overview of the status of the 3GPP standardization process, we model and analyze the user data performance, specifically in the uplink access and the satellite multi‐hop constellation path. The evaluation of the collisions, the delay and Age of Information, and the comparison of the terrestrial and the satellite access networks provide useful insights to understand the potential of LEO constellations for offloading and backhauling of IoT traffic.
Enhanced differentiation of human induced pluripotent stem cells toward the midbrain dopaminergic neuron lineage through GLYPICAN-4 downregulation
Authors: Corti Serena , Bonjean Remi , Legier Thomas , Rattier Diane , Melon Christophe , Salin Pascal , Toso Erik A. , Kyba Michael , Kerkerian-Le Goff Lydia , Maina Flavio , Dono Rosanna
Published: February 2021

Enhancing the differentiation potential of human induced pluripotent stem cells (hiPSC) into disease-relevant cell types is instrumental for their widespread application in medicine. Here, we show that hiPSCs downregulated for the signaling modulator GLYPICAN-4 (GPC4) acquire a new biological state characterized by increased hiPSC differentiation capabilities toward ventral midbrain dopaminergic (VMDA) neuron progenitors. This biological trait emerges both in vitro, upon exposing cells to VMDA neuronal differentiation signals, and in vivo, even when transplanting hiPSCs at the extreme conditions of floor-plate stage in rat brains. Moreover, it is compatible with the overall neuronal maturation process toward acquisition of substantia nigra neuron identity. HiPSCs with downregulated GPC4 also retain self-renewal and pluripotency in stemness conditions, in vitro, while losing tumorigenesis in vivo as assessed by flank xenografts. In conclusion, our results highlight GPC4 downregulation as a powerful approach to enhance generation of VMDA neurons. Outcomes may contribute to establish hiPSC lines suitable for translational applications.
Neural crest-like stem cells for tissue regeneration
Authors: Soto Jennifer , Ding Xili , Wang Aijun , Li Song
Published: February 2021

Neural crest stem cells (NCSCs) are a transient population of cells that arise during early vertebrate development and harbor stem cell properties, such as self-renewal and multipotency. These cells form at the interface of non-neuronal ectoderm and neural tube and undergo extensive migration whereupon they contribute to a diverse array of cell and tissue derivatives, ranging from craniofacial tissues to cells of the peripheral nervous system. Neural crest-like stem cells (NCLSCs) can be derived from pluripotent stem cells, placental tissues, adult tissues, and somatic cell reprogramming. NCLSCs have a differentiation capability similar to NCSCs, and possess great potential for regenerative medicine applications. In this review, we present recent developments on the various approaches to derive NCLSCs and the therapeutic application of these cells for tissue regeneration.
Heat‐resistant superamphiphobic robust surface by self‐assembled monolayer surface reaction
Authors: Liu Taolin , Kong Fanxin , Mao Wentao , Kong Qinggang , Kong Fanzhen , Qian Haiyan
Published: February 2021

Superamphiphobic surfaces have been arousing great attention in recent years for improved durability in practical applications. In this study, composites of dual‐sized porous silicas of micro‐/nanoparticles and silicic acid binder were coated on the glassy substrate as the micro‐/nano‐structure, then 60 nm porous silica particles modified by 3‐aminopropyltriethoxysilane (APTS) were coated. With the aid of the efficient, rapid, and stoichiometric reaction of amino group and epoxy group, the monolayer low‐surface‐energy long perfluorinated chains self‐assembled in the surface. Field emission scanning electron microscope (FESEM) and atomic force microscopy (AFM) verified the concave–convex surface topological features. This surface realized super‐repellency to liquids (surface tension ranging from 72.0 to 27.2 mN/m). This surface sustains superamphiphobicity after 15 times of the tape tearing test. After soaking in base (pH = 14), acid (pH = 1), and n‐heptane for 20 days, this surface still holds superamphiphobicity. Its heat‐resistant ability is so outstanding that it keeps superamphiphobicity after drying for 3 h at 250°C.
The length of the receiver operating characteristic curve and the two cutoff Youden index within a robust framework for discovery, evaluation, and cutoff estimation in biomarker studies involving improper receiver operating characteristic curves
Authors: Bantis Leonidas E. , Tsimikas John V. , Chambers Gregory R. , Capello Michela , Hanash Samir , Feng Ziding
Published: February 2021

During the early stage of biomarker discovery, high throughput technologies allow for simultaneous input of thousands of biomarkers that attempt to discriminate between healthy and diseased subjects. In such cases, proper ranking of biomarkers is highly important. Common measures, such as the area under the receiver operating characteristic (ROC) curve (AUC), as well as affordable sensitivity and specificity levels, are often taken into consideration. Strictly speaking, such measures are appropriate under a stochastic ordering assumption, which implies, without loss of generality, that higher measurements are more indicative for the disease. Such an assumption is not always plausible and may lead to rejection of extremely useful biomarkers at this early discovery stage. We explore the length of a smooth ROC curve as a measure for biomarker ranking, which is not subject to directionality. We show that the length corresponds to a divergence, is identical to the corresponding length of the optimal (likelihood ratio) ROC curve, and is an appropriate measure for ranking biomarkers. We explore the relationship between the length measure and the AUC of the optimal ROC curve. We then provide a complete framework for the evaluation of a biomarker in terms of sensitivity and specificity through a proposed ROC analogue for use in improper settings. In the absence of any clinical insight regarding the appropriate cutoffs, we estimate the sensitivity and specificity under a two‐cutoff extension of the Youden index and we further take into account the implied costs. We apply our approaches on two biomarker studies that relate to pancreatic and esophageal cancer.
Phase‐Transfer Strategy toward High‐Throughput Chromatographic Detection of Pentosan Content in Wheat‐Derived Products
Authors: Xie Wei‐Qi , Gong Yi‐Xian , Huang Shi‐Wen , Yu Kong‐Xian
Published: February 2021

This paper demonstrated a new approach for detecting pentosan content in wheat products enabled by phase‐transfer reaction technique. This approach was based on the phase‐transfer reaction of pentosans in wheat sample to furfural in an acidic medium. The hydrolysis reaction could be finished within 30 min at 90 °C, with a sulfuric acid concentration of 12.0 mol/L. The furfural generated from the hydrolysis of pentosan was then measured by headspace gas chromatography (HS‐GC) using a flame ionization detector (FID). The results showed that this method was precise (relative standard deviations (RSD)≤2.82 %) and accurate (relative differences (RD)≤6.49 % compared with the reference spectrophotometric method, the recoveries ranged from 98.1 to 102 %). Moreover, the developed approach is semi‐automated and efficient, which can be a good alternative method for the high‐throughput analysis of pentosan content in both laboratory and mill testing.
Solvent‐Free Single‐Pot Mannich Reaction and Detoxification of Industrial Hazardous Waste Methyl Mercaptan Gas
Authors: Swain Sharada Prasanna , Prasad Nagendra , Reddy Latchi , Subrahmanyam G. , Mohanty Sandeep
Published: February 2021

Environment pollution is causing serious human health issues and forest deterioration. Methyl mercaptan is a malodorous gaseous pollutant, which is a by product of sewage treatment plants, pulp plants, petrochemical plants, agrochemicals, and some pharmaceutical products. A long term exposure to methyl mercaptan may lead to adverse effects on central nervous system and cardiovascular system. The pharmaceutical industries are devoting significant efforts to develop process by using green solvents like water, and develop solvent‐free reactions. This will help to develop green, sustainable methods for the synthesis of API and reduce the manufacturing cost. A ZnCl2 catalyzed solvent‐free, one‐pot process for the synthesis of ranitidine and quenching of hazardous waste methyl mercaptan gas to a useful product have been developed.
Amidine Derivatives of Avibactam: Synthesis and In Vitro β‐Lactamase Inhibition Activity
Authors: Gao Yuanyu , Liu Yuanbai , Iqbal Zafar , Sun Jian , Ji Jinbo , Zhai Lijuan , Tang Dong , Ji Jingwen , He Lili , Mu Yangxiu , Yang Haikang , Yang Zhixiang
Published: February 2021

Avibactam is a non‐β‐lactam based second generation β‐lactamase inhibitor containing diazabicyclooctane (DBO) ring as the β‐lactam mimic. We substituted C2 position of DBO scaffold by a number of amidine derivatives to form water soluble final compounds A1‐A14. The synthesized compounds were evaluated for their antibacterial and synergistic activity in combination with an antibiotic in vitro. The compounds, were tested against ten bacterial strains alone and in combination with existing antibiotic, meropenem. All compounds didn't show antibacterial activity when alone (MIC,>128 μM), however exhibited moderate to good synergistic activity in the presence of meropenem by lowering its MIC values. Compound A7 proved the most potent among other counterparts against all bacterial species with MIC from <0.29 μM to 2.34 μM, and showed comparable or improved activity to avibactam against eight bacterial strains. Compound A7 may prove a lead for next level in vivo and clinical studies.
Immobilization of Active Substances in Food Using Self‐Organized Patterned Porous Film via Breath Figure Approach
Authors: Zhang Simin , Peng Bo , Li Meng , Diao Huayu , Wang Xingyu , Zhao Weiping , Lin Wei , Sun Na , Lin Songyi
Published: February 2021

Micropattern of bioactive substances in food, such as functional protein and enzyme immobilization, play a crucial role in catalysis, proteomics, tissue engineering, nutrition transportation and biological detection. Currently, various techniques have been reported for the immobilization of bioactive substances on solid but the fabricated methods are often not facile and universal. In this study, we overcome these problems to localized capture ovalbumin (OVA) and trypsin (Try) efficiently by fabricating patterned porous film via simple breath figure approach. Upon optimization of preparation conditions, ordered honeycomb porous film were obtained. We confirmed the morphology and investigated thermostability and surface wettability of porous film. The immobilization of OVA and Try was confirmed by confocal laser scanning microscopy and SDS‐polyacrylamide gel electrophoresis, respectively. To our best knowledge, this work is the first report on patterning and trapping of food protein and enzyme via self‐organized patterned porous film. Our findings are essential for establishing a new convenient and efficient route to design food protein/enzyme‐trapped porous film materials, which opens a new sustainable way for food protein/enzyme immobilization and expected to used in the food industry, biological applications, and so on.
Array Integration and Far‐Field Detection of Biocompatible Wireless LC Pressure Sensors
Authors: Wen Hao , Chen Caifeng , Li Shengyou , Shi Yating , Wang Hao , Guo Wenxi , Liu Xiangyang
Published: February 2021

In this paper, three configurations of LC (inductor–capacitor) pressure sensors are developed, namely series LC pressure sensors, compact LC pressure sensors, and far‐field LC pressure sensor tags. The modified silk protein films have been chosen as substrates due to their good biocompatibility and air/water permeability, which is suitable for continuously pasting such substrates on skin. For series LC pressure sensors, conducting wire is used to connect the flexible capacitor and spiral inductor. It exhibits good cycling stability and high sensitivities, suitable for electronic skin. For compact LC pressure sensors, the spiral coil functions as inductor, antenna, and capacitor electrode simultaneously, minimizing the space cost and is suitable for array integration, while the sensitivities remain the same. By tailoring the turn of the spiral coil, the resonate frequency can be regulated continuously. An annular array of compact LC sensors with ten distinct resonate frequencies ranged from 400 to 1000 MHz is developed to remotely monitor the press of number 0–9. Finally, far‐field LC pressure sensor tags with elongated detection distances are developed in which each compact LC sensor acts as a filter. A wireless in‐shoe plantar to detect the sole pressure distribution using the far‐field LC sensor configuration is developed.
Formation Mechanism of PFN Dipole Interlayer in Organic Solar Cells
Authors: Feng Chuang , Wang Xiaojing , He Zhicai , Cao Yong
Published: February 2021

Water‐/alcohol‐soluble polyelectrolyte poly[(9, 9‐bis (3′‐(N,N‐dimethylamino) propyl)‐2, 7‐fluorene)‐alt‐2, 7‐(9, 9‐dioctylfluorene)] (PFN) used in organic solar cells (OSCs) reduces the work function of the electrode due to the effect of an interfacial dipole, which is beneficial for the energy‐level alignment between the electrode and the active layer. To date, the studies on the working mechanism of PFN are mainly conducted through topographical and electronic research. Herein, a dynamic insight into the formation mechanisms of the PFN interlayer at the molecular structural level is established. The charge transfer between PFN and the substrates is verified for the first time by X‐ray photoelectron spectroscopy (XPS) and density functional theory (DFT) studies, which results in chemisorption dipoles with their direction aligned with the intrinsic dipole of the PFN molecule, thereby reducing the work function of the substrate. The larger adsorption energy in the substrates of the nitrogen‐containing side chains of PFN is also identified, which induces the preferential orientation of PFN molecule to reduce the work function of the substrate. By incorporating this interlayer, high efficiency in single‐junction OSCs is achieved using commercial materials. The findings are of great significance for understanding and optimizing the polymer dipole interlayers for OSCs.
Use of Sodium Diethyldithiocarbamate to Enhance the Open‐Circuit Voltage of CH3NH3PbI3 Perovskite Solar Cells
Authors: Más-Montoya Miriam , Curiel David , Wang Junke , Bruijnaers Bardo J. , Janssen René A. J.
Published: February 2021

The incorporation of additives to modulate the properties of metal halide perovskite thin films has become a successful approach in improving the power conversion efficiency of perovskite‐based solar cells. Herein, the beneficial use of sodium diethyldithiocarbamate (NaDEDTC) as processing agent in improving the open‐circuit voltage of methylammonium lead triiodide perovskite solar cells is reported. DEDTC reduces the rate of perovskite crystallization. Absorption and emission spectra show that the optical bandgap of the perovskite films remain essentially unchanged and X‐ray diffraction reveals the formation of preferentially oriented crystallites independent of the use of DEDTC. The use of DEDTC, however, results in a decrease in nonradiative decay as inferred from a two order of magnitude increase in electroluminescence efficiency, explaining the increased open‐circuit voltage. Fourier‐transform infrared spectroscopy, nuclear magnetic resonance, and X‐ray photoelectron spectroscopy show that the DEDTC ligand is not present after the film processing. Therefore, DEDTC modulates film formation but is not incorporated in the perovskite or present as a surface ligand. Sodium ions, on the contrary, are incorporated in the perovskite layer.
How and Why to Investigate Multicomponent Reactions Mechanisms? A Critical Review
Authors: Rodrigues Marcelo O. , Eberlin Marcos N. , Neto Brenno A. D.
Published: February 2021

We review the most innovative efforts and greatest challenges faced when elucidating multicomponent reactions (MCRs) mechanisms. When compared to traditional reactions, the often two or more concurrent reactions pathways and the greater number of possible intermediates in MCRs turn their mechanistic investigation both a harder and trickier task. The common approaches used to investigate reaction mechanisms are often unable to clarify MCRs mechanisms; hence few but clever approaches are currently used to determine these mechanisms and to depict their key transformations. Their complexity has required most innovative approaches and the use of a number of unique techniques that have shed light over the favored pathway selected from the myriad of alternatives theoretically available for MCRs. This review focuses on the most successful efforts applied by a few leading groups to perform these puzzlingly investigations.
Synthetic Routes Towards the Synthesis of Geminal α‐Difunctionalized Ketones
Authors: Day David P. , Vargas Jorge A. M. , Burtoloso Antonio C. B.
Published: February 2021

The importance of gem‐difunctionalized ketones is represented by their broad applications across chemical boundaries over recent years. The interesting reactivities that this class of compounds possess have made them ideal building blocks to access high‐value organic molecules. Furthermore, the gem‐difunctionalized ketone moiety has featured in numerous bioactive molecules. For these reasons, a plethora of routes to access such significant molecules have been developed by research groups worldwide – this account looks at delineating the synthesis of gem‐difunctionalized ketones from carbonyl substrates, diazo compounds, sulfur ylides and alkynyl reactants.
Predicting academic and career choice: The role of transformative experience, connection to instructor, and gender accounting for interest/identity and contextual factors
Authors: Pugh Kevin J. , Paek Sue Hyeon , Phillips Michael M. , Sexton Julie M. , Bergstrom Cassendra M. , Flores Selani D. , Riggs Eric M.
Published: February 2021

We used the social‐cognitive choice model (Lent et al., 2018) as a framework for investigating academic and career choice in the domain of geoscience for male and female students. In addition, we explored the role of perceived connection to instructors and transformative experience as additional factors in the social‐cognitive choice model. A total of 525 individuals from six geoscience departments participated. We conducted three path models with confidence in geoscience among majors (Model 1), intent to major in geoscience among non‐majors (Model 2), and intent to pursue a career in geoscience (Model 3) as outcome variables. Overall, the baseline social‐cognitive choice model explained a moderate amount of variance with variation by model and gender. Students' interest in and identification with geoscience was an important direct predictor of outcomes in all three models. Adding connection to instructor to the baseline model significantly increased the model fit and contributed to the amount of variance explained in Models 2 and 3, but not Model 1. Further, connection to instructor was found to mediate the relation between interest/identity and outcomes as well as directly predict outcomes in Models 2 and 3. These results held for male and female students. Adding transformative experience to the baseline plus connection to instructor model further increased the model fit and contributed to the amount of variance explained for female student in Models 2 and 3, but not for Model 1 and not for male students. Further, transformative experience was found to mediate the relation between interest/identity and outcomes as well as directly predict outcomes in all three models, but only for female students. These results suggest instructors may strengthen geoscience pathways by developing students' interest in geoscience, establishing connections with students, and, for female students, fostering transformative experiences.
Rights and Responsibilities With Tech: Students’ Take on Classroom Policies
Authors: Hsin Lisa B. , Mu Nan , Selman Robert L.
Published: February 2021

We paint a picture of preadolescent students’ thinking on a topic of everyday importance: the right to use and the responsibility not to abuse digital technology in school. We analyzed the writing of students in grades 4–7 in response to an essay prompt about classroom iPad (tablet computer) use after a hypothetical cyberbullying incident, focusing on the solutions that students proposed to avoid a repeat infraction. Solutions were categorized into six types, each of which, in turn, tended to embody one of the two orientations toward this issue: One emphasized restricting rights to device access, and the other placed responsibility for appropriate device use on the students themselves. We explored students’ focus on rights or responsibilities in light of their social perspective‐taking skills and their grade level. Findings suggest that grappling with urgent, personally relevant social and moral issues stimulates analytic and writing skills.
High‐temperature stabilization of polypropylene using hindered phenol–thioester stabilizer combinations, Part 2: Optimization and efficacy via encapsulation with silicate fillers
Authors: Allen Norman S. , Jones Andrew P. , Liauw Christopher M. , Edge Michele , Keck‐Antoine Klaus , Yeo Joeng‐Ho
Published: February 2021

The thermal degradation of unstabilized polypropylene has been investigated under long‐term thermal aging at 150°C, with additive concentration studies on combinations of an established hindered phenolic antioxidant (pentaerythritol tetrakis (3‐(3,5‐di‐tert‐butyl‐4‐hydroxyphenyl) propionate) [S1010] and two popular thioesters (distearyl‐3,3′‐thiodipropionate [DSTDP] and didodecyl‐3,3′‐thiodipropionate [DLTDP]) using melt flow rate (MFR), carbonyl index (Fourier transform spectroscopy [FTIR]) and differential scanning calorimetry (DSC) (oxidation induction time [OIT]) and ultimate embrittlement time (fracture) on injection‐molded test pieces. It was found in part 1 that 20:80 phenol:thioester ratios provided the best long‐term thermal stability (LTTS). Part 2 investigates potential improvements in stabilization, involving the use of controlled release systems in which the stabilizers are melt blended in the PP together with high surface area inorganic substrates. Here, a calcined gel silica SD3128 and two layered silicates Rockwood Additives Fulcat® 800 and Laponite® B were incorporated into the polymer formulations in order to limit stabilizer mobility at 6000 ppm through potential surface adsorption and subsequent controlled release. Additional hindered amine light stabilizers were also added as long‐term heat stabilizers and to act as displacing agents that promote controlled release via competitive adsorption on processing due to the strongly adsorbing amine functionalities. In some instances, the LTTS showed improvement. Flow micro calorimetry was used to investigate the stabilizer–substrate interactions. It was found that as a result of its small pore structure, Laponite B could only adsorb smaller molecules such as that of DLTDP while Fulcat® 800 was a more strongly adsorbing substrate with larger pores able to accommodate even the largest of the hindered amine light stabilizer (HALS) molecules. The gel silica SD3128 had overall the most adsorbing ability with each of these characteristics supporting the aging data studied in parallel. The data are discussed in relation to the long‐term stabilization of polypropylene in high‐temperature applications such as under the bonnet of automobiles where minimizing stabilizer losses and maximizing synergy are important.
Tailoring the optical properties of PVA/PVP blend by doping with Cu/MnS nanoparticles
Authors: Heiba Zein K. , Mohamed Mohamed Bakr , Ahmed Sameh I. , Alhazime Ali A.
Published: February 2021

PVA/PVP blend embedded with different ratios of nano Cu0.9Mn0.1S (Cu/MnS) was prepared with thermolysis and casting techniques. X‐ray diffraction analysis showed the formation of nano Cu/MnS as a single hexagonal phase with an average crystallite size 11 nm. Scanning electron microscope (SEM) revealed nearly homogenous particles morphology. Fourier transform infrared (FTIR) spectroscopy technique was applied to characterize the Cu/MnS doped PVA/PVP matrix. UV measurements were utilized to investigate the optical properties in detail. Upon doping with Cu/MnS, the bandgap of PVA/PVP was significantly decreasing with the amount of doping; which enabling tailoring the band gap depending on the doping content. The analysis showed that the main possible transitions in pure PVA/PVP blend are indirect allowed and direct forbidden. On the other hand, for the doped blend samples, the direct allowed is the main possible transition. Moreover, the refractive index and the real and imaginary parts of the dielectric constant increased upon increasing the Cu/MnS amount doped.
Resocializing digital water transformations: Outlining social science perspectives on the digital water journey
Authors: Hoolohan Claire , Amankwaa Godfred , Browne Alison L. , Clear Adrian , Holstead Kirsty , Machen Ruth , Michalec Ola , Ward Sarah
Published: February 2021

Digital water transformation is often written about as though universally desirable and inevitable, capable of addressing the multifaceted socioecological challenges that water systems face. However, there is not widespread reflection on the complexities, tensions and unintended consequences of digital transformation, its social and political dimensions are often neglected. This article introduces case studies of digital water development, bringing examples of technological innovation into dialogue with literature and empirical research from across the social sciences. We examine how Big Data affects our observations of water in society to shape water management, how the Internet of Things becomes involved in reproducing unjust water politics, how digital platforms are entangled in the varied sociocultural landscape of everyday water use, and how opensource technologies provide new possibilities for participatory water governance. We also reflect on regulatory developments and the possible trajectories of innovation resulting from public‐private sector interactions. A socially and politically informed view of digital water is essential for just and sustainable development, and the gap between industry visions of digital water and research within the social sciences is inhibitive. Thus, the analysis presented in this article provides a novel, pluralistic perspective on digital water development and outlines what is required for more inclusive future scholarship, policy and practice.

This article is categorized under:

Human Water
An actuator‐line model with Lagrangian‐averaged velocity sampling and piecewise projection for wind turbine simulations
Authors: Xie Shengbai
Published: February 2021

A new approach is proposed to do the velocity sampling for actuator‐line models (ALM). Unlike the conventional spatial averaging approaches, the velocity sampling is performed in a Lagrangian averaging way along flow paths with a time scale depending on the local flow patterns. The new approach is evaluated by large‐eddy simulations of a utility‐scale National Renewable Energy Laboratory (NREL)‐5MW wind turbine. The results show that the Lagrangian approach of velocity sampling is effective to reduce the spurious numerical oscillations in the modeling results. The good match with the benchmark data indicates that correct free upwind velocity can be obtained with a careful determination of the associated time scale. Also, a piecewise function is proposed to replace the Gaussian function for the force projection process.
Metagenomic prediction analysis of microbial aggregation in anammox‐dominated community
Authors: Jia Fangxu , Peng Yongzhen , Li Jianwei , Li Xiyao , Yao Hong
Published: February 2021

Aggregation of anammox bacteria is essential to maintain high biomass concentrations and prevent the loss of biomass in anammox processes. PICRUSt (Phylogenetic Investigation of Communities by Reconstruction of Unobserved States) was used in this study to predict the metagenomic potentials and characterize the microbial community structure and functional features in anammox aggregates (e.g., sludge flocs, biofilms, and granules). The results showed that Candidatus Brocadia was the most dominant anammox genera in all aggregates (38.0% in flocs, 69.4% in biofilm, and 52.0% in granules) and the functional gene involved in the anammox process was detected in the highest amount in biofilms, followed by granules and flocs. Furthermore, the anammox microbial aggregation pathway was explored that anammox bacteria have strong motility and high capability for early attachment. Anammox bacteria could produce large amounts of EPS (extracellular polymeric substances) regulated by quinolone and transport to extracellular environment through type II secretion system. The strong ability of c‐di‐GMP (bis‐(3′‐5′)‐cyclic dimeric guanosine monophosphate) synthesis enabled a stable architectural structure of aggregation. This study elucidated the aggregation mechanism of anammox microorganisms at the genetic level to enhance the stability of anammox processes.

Practitioner points

Candidatus Brocadia was the most dominant anammox genera in aggregates.

Anammox bacteria have strong motility and high attachment capability.

Anammox bacteria possess strong EPS synthesis regulated by quinolone.

c‐di‐GMP synthesis enables a stable structure of aggregation.