bluuebunny/crossref_metadata_2025 huggingface dataset:
Seasonal and interannual variability of the Queen Maud Gulf ecosystem derived from sediment trap measurements
Authors: Dezutter Thibaud , Lalande Catherine , Darnis Gérald , Fortier Louis
Published: October 2020

Several years of monitoring in the northern Canadian Arctic Archipelago contrast with a lack of repeated measurements in Queen Maud Gulf. As sea ice cover declines and maritime traffic increases along the Northwest Passage, Queen Maud Gulf, including the protected national historic sites of the HMS Erebus and HMS Terror wrecks, may experience drastic environmental changes. As part of the Kitikmeot Marine Ecosystems Study, moored oceanographic devices including a sediment trap were deployed in Queen Maud Gulf over three consecutive annual cycles from October 2015 to August 2018 to study the functioning of this geographic bottleneck along the Northwest Passage. Seasonal and interannual variability in total particulate matter (TPM), particulate organic carbon (POC), and microalgal fluxes were investigated in relation to wind speed, snow depth, sea ice cover, water temperature, and current velocity. Zooplankton and meroplankton present in the sediment trap were enumerated to monitor their composition and seasonal development. Landfast ice breakup consistently occurred in early June, followed by sea ice breakup in July. The release of sea ice algae was initiated in March 2016, May 2017, and June 2018, whereas peaks in diatom fluxes occurred in August or September. Sustained abundance of pelagic copepods and meroplankton suggested an ecosystem sufficiently productive to support the year‐round development of the pelagic and benthic communities. Elevated autumn TPM and POC fluxes reflected wind‐induced mixing and resuspension in the absence of ice cover. Our results provide a baseline for evaluating the impact of environmental changes on the Queen Maud Gulf marine ecosystem.
Croconaine‐Based Polymer Particles as Contrast Agents for Photoacoustic Imaging
Authors: Jansen Felicitas , Lamla Markus , Mauthe Diana , Fischer Stephan , Barth Holger , Kuehne Alexander J. C.
Published: October 2020

In the development and optimization of imaging methods, photoacoustic imaging (PAI) has become a powerful tool for preclinical biomedical diagnosis and detection of cancer. PAI probes can improve contrast and help identify pathogenic tissue. Such contrast agents must meet several requirements: they need to be biocompatible, and absorb strongly in the near‐infrared (NIR) range, while relaxing the photoexcited state thermally and not radiatively. In this work, polymer nanoparticles are produced with croconaine as a monomer unit. Small molecular croconaine dyes are known to act as efficient pigments, which do not show photoluminescence. Here, for the first time croconaine copolymer nanoparticles are produced from croconic acid and a range of aromatic diamines. Following a dispersion polymerization protocol, this approach yields monodisperse particles of adjustable size. All synthesized polymers exhibit broad absorption within the NIR spectrum and therefore represent suitable candidates as contrast agents for PAI. The optical properties of these polymer particles are discussed with respect to the relation between particle size and outstanding photoacoustic performance. Biocompatibility of the polymer particles is demonstrated in cell viability experiments.
Synthesis and Encapsulation of Uniform Star‐Shaped Block‐Macromolecules
Authors: Waibel Kevin A. , Moatsou Dafni , Meier Michael A. R.
Published: October 2020

Linear uniform oligomers synthesized via a two‐step iterative cycle are postmodified with uniform octaethylene glycol monomethyl ether and finally coupled via azide‐alkyne cycloaddition to yield uniform star‐shaped block macromolecules with a mass ranging from 10 to 14 kDa. Each of the molecules is carefully characterized by NMR, electrospray ionization mass spectrometry (ESI‐MS), and size exclusion chromatography (SEC) to underline their purity as well as their uniformity. The obtained star‐shaped macromolecules are investigated in their ability to encapsulate dye molecules by carrying out qualitative solid–liquid phase transfer experiments.
Racemic S‐(ethylsulfonyl)‐dl‐cysteine N‐Carboxyanhydrides Improve Chain Lengths and Monomer Conversion for β‐Sheet‐Controlled Ring‐Opening Polymerization
Authors: Bauer Tobias A. , Muhl Christian , Schollmeyer Dieter , Barz Matthias
Published: October 2020

The secondary structure formation of polypeptides not only governs folding and solution self‐assembly but also affects the nucleophilic ring‐opening polymerization of α‐amino acid‐N‐carboxyanhydrides (NCAs). Whereby helical structures are known to enhance polymerization rates, β‐sheet‐like assemblies reduce the propagation rate or may even terminate chain growth by precipitation or gelation. To overcome these unfavorable properties, racemic mixtures of NCAs can be applied. In this work, racemic S‐(ethylsulfonyl)‐dl‐cysteine NCA is investigated for the synthesis of polypeptides, diblock and triblock copolypept(o)ides. In contrast to the polymerization of stereoregular S‐(ethylsulfonyl)‐l‐cysteine NCA, the reaction of S‐(ethylsulfonyl)‐dl‐cysteine NCA proceeds with a rate constant of up to kp = 1.70 × 10−3 L mol−1 s −1 and is slightly faster than the enatiopure polymerization. While the polymerization of S‐(ethylsulfonyl)‐l‐cysteine NCA suffers from incomplete monomer conversion and degrees of polymerization (DPs) limited to 30–40, racemic mixtures yield polypeptides with DPs of up to 102 with high conversion rates and well‐defined dispersities (1.2–1.3). The controlled living nature of the ring‐opening polymerization of S‐(ethylsulfonyl)‐dl‐cysteine NCA thus enables the synthesis of triblock copolymers by sequential monomer addition. This methodology allows for precise control over DPs of individual blocks and yields uniform triblock copolymers with symmetric molecular weight distributions at a reduced synthetic effort.
Influence of Iron Doped on Structural and Optical Absorption Studies of Calcium Borophosphate (CaBP) Nanophosphors
Authors: Mudi Rajesh Y. , Pambi P. Radha K. , Ganti Venkata L. K. , N.S.S.V.R. Ravikumar
Published: October 2020

Novel inorganic phosphor luminescent materials are widely used in various optoelectronic devices such as field emission displays, plasma display panels, solid state lasers, cathode‐ray tubes, and tricolor white light emitting diodes. Structural and luminescence properties of calcium borophosphate phosphors with different Fe3+ concentrations using solid state reaction technique have been investigated. X‐ray powder diffraction reveals that all samples exhibited a triclinic system of CaBP and lattice parameter analysis indicated the dopant ions may be substituted into the lattice position of the parent atom. The surface morphology of prepared nanophosphors is identified by SEM with EDS and TEM, which shows spherical‐like chains in an irregular spatial distribution with less agglomeration. Optical studies give the information about the site symmetry of dopant ions with host ligands.
Kinetics and Mechanism of Oxidation of Glutahione by Waugh‐Type Enneamolybdomanganate(IV) in Aqueous Perchloric Acid
Authors: More Shekhar S. , Gurume Vashistha M. , Gokavi Gavisiddappa S.
Published: October 2020

The reaction between enneamolybdomanganate(IV) and glutathione is studied under second‐order conditions in aqueous perchloric acid. The reaction first‐order in both the reactants and initiated through formation of a precursor complex. Protonated forms of both the reactants are found to be active as evidenced by the accelerating effect of increasing hydrogen ion concentration effect. The second step of the reaction is the slow decomposition of the complex leading to the formation of hydroxyl intermediate. The final product glutathione disulfide is formed in the fast third step as a result of reaction of intermediate with another glutathione cation.
A novel gingipain regulatory gene in Porphyromonas gingivalis mediates host cell detachment and inhibition of wound closure
Authors: Liu Hongyan , Huang Lijia , Cai Yanling , Bikker Floris J. , Wei Xi , Mei Deng Dong
Published: October 2020

The black pigmentation‐related genes in Porphyromonas gingivalis are primarily involved in regulating gingipain functions. In this study, we identified a pigmentation‐related gene, designated as pgn_0361. To characterize the role of pgn_0361 in regulating P. gingivalis‐mediated epithelial cell detachment and inhibition of wound closure, PgΔ0361, an isogenic pgn_0361‐defective mutant strain, and PgΔ0361C, a complementation strain, were constructed using P. gingivalis ATCC 33277. The gingipain and hemagglutination activities, as well as biofilm formation, were examined in all three strains. The effect of P. gingivalis strains on epithelial cell detachment was investigated using the HO‐1‐N‐1 and Ca9‐22 epithelial cell lines. The inhibition of wound closure by heat‐killed P. gingivalis cells and culture supernatant was analyzed using an in vitro wound closure assay. Compared to the wild‐type strain, the PgΔ0361 strain did not exhibit gingipain or hemagglutination activity but exhibited enhanced biofilm formation. Additionally, the PgΔ0361 strain exhibited attenuated ability to detach the epithelial cells and to inhibit wound closure in vitro. Contrastingly, the culture supernatant of PgΔ0361 exhibited high gingipain activity and strong inhibition of wound closure. The characteristics of PgΔ0361C and wild‐type strains were comparable. In conclusion, the pgn_0361 gene is involved in regulating gingipains. The PGN_0361‐defective strain exhibited reduced virulence in terms of epithelial cell detachment and inhibition of wound closure. The culture supernatant of the mutant strain highly inhibited wound closure, which may be due to high gingipain activity.
Motion‐compensated gradient waveforms for tensor‐valued diffusion encoding by constrained numerical optimization
Authors: Szczepankiewicz Filip , Sjölund Jens , Dall’Armellina Erica , Plein Sven , Schneider Jürgen E. , Teh Irvin , Westin Carl‐Fredrik
Published: October 2020

Purpose

Diffusion‐weighted MRI is sensitive to incoherent tissue motion, which may confound the measured signal and subsequent analysis. We propose a “motion‐compensated” gradient waveform design for tensor‐valued diffusion encoding that negates the effects bulk motion and incoherent motion in the ballistic regime.

Methods

Motion compensation was achieved by constraining the magnitude of gradient waveform moment vectors. The constraint was incorporated into a numerical optimization framework, along with existing constraints that account for b‐tensor shape, hardware restrictions, and concomitant field gradients. We evaluated the efficacy of encoding and motion compensation in simulations, and we demonstrated the approach by linear and planar b‐tensor encoding in a healthy heart in vivo.

Results

The optimization framework produced asymmetric motion‐compensated waveforms that yielded b‐tensors of arbitrary shape with improved efficiency compared with previous designs for tensor‐valued encoding, and equivalent efficiency to previous designs for linear (conventional) encoding. Technical feasibility was demonstrated in the heart in vivo, showing vastly improved data quality when using motion compensation. The optimization framework is available online in open source.

Conclusion

Our gradient waveform design is both more flexible and efficient than previous methods, facilitating tensor‐valued diffusion encoding in tissues in which motion would otherwise confound the signal. The proposed design exploits asymmetric encoding times, a single refocusing pulse or multiple refocusing pulses, and integrates compensation for concomitant gradient effects throughout the imaging volume.
Undergraduate nursing students’ knowledge, attitudes and self‐efficacy regarding palliative care in China: A descriptive correlational study
Authors: Zhou Yinghua , Li Qiao , Zhang Wei
Published: October 2020

Aim

To describe nursing students’ knowledge, attitudes and self‐efficacy about palliative care and to examine the associations between these variables in China.

Design

A descriptive correlational study.

Methods

Undergraduate nursing students (N = 187) at the end of third year of education from a university were surveyed. Measurements included the Chinese versions of the Palliative Care Quiz for Nursing, the Death Attitude Profile‐Revised, the Frommelt Attitude Toward Care of the Dying Scale and the Palliative Care Self‐Efficacy Scale. Descriptive and correlational analyses were performed.

Results

Although most nursing students had favourable attitudes towards death and caring for the dying, students had low level of knowledge and self‐efficacy regarding palliative care, suggesting the need for integrating palliative care education into nursing curriculum in China. Moreover, special attention should be paid to psychosocial and spiritual care teaching and preparing students to psychologically deal with the challenges in the process of patient's dying.
Sustainable washing‐free printing of disperse dyes on polyester fabrics enabled by crosslinked fluorosilicone modified polyacrylate binders
Authors: Jiang Jiantang , Shen Yifeng , Yu Deyou , Wu Minghua , Yang Lei , Li Shaoqi
Published: October 2020

The printing of polyester (PET) fabrics using binders and disperse dyes is an environmentally less harmful technique due to the exclusion of water‐intensive washing processes. Unfortunately, the conventional polyacrylate (PA) binders are inapplicable for this printing technique as the high PA‐disperse dye compatibility restrains the migration of disperse dye molecules from binder films into PET fabrics. Herein, we demonstrate a rational design and synthesis of novel PA binders by copolymerizing fluorosilicone monomers with multi‐vinyl groups for the sustainable printing of PET fabrics. The incorporated fluorosilicone functionalities significantly decrease the solubility parameter of PA, facilitating the dye molecules migration toward PET fabrics. Meanwhile, the crosslink structure formed via vinyl groups restrains the migration of polymer chains and thus allows for the anchor of F/Si segments, enabling the continuous migration of disperse dyes. As a result, both the utilization ratio of disperse dyes and the color yield and fastness of printed PET fabrics are substantially improved. Moreover, the washing‐free printing process using the developed binder can reduce 73% of water consumption, 74% of energy input, and 100% of wastewater discharge over the traditional printing process. Our study may provide insights into rational design of binders for the sustainable printing of PET fabrics.
Lightweight poly (vinylidene fluoride)/silver nanowires hybrid membrane with different conductive network structure for electromagnetic interference shielding
Authors: Qian Jing , Zhang Zheng‐Min , Bao Rui‐Ying , Liu Zheng‐Ying , Yang Ming‐Bo , Yang Wei
Published: October 2020

Electromagnetic interference (EMI) shielding materials with silver nanowires (AgNWs) have been widely reported to deal with electromagnetic radiation pollution. However, few studies focus on the effect of the spatial distribution of the AgNWs on the shielding performance of materials. In this work, poly(vinylidene fluoride) (PVDF)/AgNW hybrid electrospun membranes were prepared through dip‐coating and spray‐coating of AgNWs, respectively, and the morphology features and EMI shielding effectiveness (SE) of dip‐coated and spray‐coated hybrid membranes were investigated. The results show that the AgNWs in dip‐coated samples form three‐dimensional (3D) networks and those in spray‐coated samples form a two‐dimensional (2D) layer. EMI SE of dip‐coated sample is higher than that of the spray‐coated sample at the same area density of AgNWs, though the electrical conductivity of the spray‐coated sample can be higher than that of the dip‐coated sample. At 900 mg/m2 for area density of AgNWs, EMI SE of the dip‐coated sample can reach 58.7 dB, and EMI SE of the spray‐coated sample does not exceed 33.4 dB owing to that the 3D AgNW networks formed by dip‐coating are beneficial for multiple reflection and interfacial polarization. A higher concentration of AgNW dispersion for dip‐coating leads to a more excellent EMI shielding performance, and the specific SE of the sample by dip‐coating in 0.5 wt% AgNW dispersion can reach 6.62 × 104 dB˙cm2/g due to the high SE of 107.2 dB and low density and thickness. These results reveal the effect of the structure of the AgNW networks on the EMI shielding performance of the hybrid membrane.
Cost‐effectiveness analysis of phenotypic‐guided versus guidelines‐guided bronchodilator therapy in viral bronchiolitis
Authors: Rodriguez‐Martinez Carlos E. , Nino Gustavo , Castro‐Rodriguez Jose A. , Perez Geovanny F. , Sossa‐Briceño Monica P. , Buendia Jefferson A.
Published: October 2020

Objectives

Although recent evidence suggests that management of viral bronchiolitis requires something other than guidelines‐guided therapy, there is a lack of evidence supporting the economic benefits of phenotypic‐guided bronchodilator therapy for treating this disease. The aim of the present study was to compare the cost‐effectiveness of phenotypic‐guided versus guidelines‐guided bronchodilator therapy in infants with viral bronchiolitis.

Methods

A decision analysis model was developed to compare the cost‐effectiveness of phenotypic‐guided versus guidelines‐guided bronchodilator therapy in infants with viral bronchiolitis. Phenotypic‐guided bronchodilator therapy was defined as the administration of albuterol in infants exhibiting a profile of increased likelihood of response to bronchodilators. The effectiveness parameters and costs of the model were obtained from systematic reviews of the literature with meta‐analyses and electronic medical records. The main outcome was the avoidance of hospital admission after initial care in the emergency department.

Results

Compared to guidelines‐guided strategy, treating patients with viral bronchiolitis with the phenotypic‐guided bronchodilator therapy strategy was associated with lower total costs (US$250.99; 95% uncertainty interval [UI]: US$184.37 to $336.51 vs. US$263.46; 95% UI: US$189.81 to $349.19 average cost per patient) and a higher probability of avoidance of hospital admission (0.7902; 95% UI: 0.7315–0.8356 vs. 0.7638; 95% UI: 0.7062–0.8201), thus leading to dominance. Results were robust to deterministic and probabilistic sensitivity analyses.

Conclusions

Compared to guidelines‐guided strategy, treating infants with viral bronchiolitis using the phenotypic‐guided bronchodilator therapy strategy is a more cost‐effective strategy, because it involves a lower probability of hospital admission at lower total treatment costs.
Snapshot of ammonium nitrate: History and use
Authors: Oxley Jimmie
Published: October 2020

Ammonium nitrate serves a unique spot in society. It can generate non‐toxic, non‐carbonaeous gases; it can provide nitrogen in the form of nitrate which can be quickly taken up by growing plants; and it can be formulated into a low brisant explosive. On the flip‐side, ammonium nitrate is subject to decomposition by heat, humidity and acidicity; and its widespread availability make it a tempting ingredient for terrorists.
“Decentring” international student mobility: The case of African student migrants in China
Authors: Mulvey Benjamin
Published: October 2020

Despite the growth in numbers and geopolitical relevance of African students in China, research focusing on this body of student migrants remains scarce. This article presents an empirical investigation and postcolonial theorisation of student migration between Africa and China. Drawing on data from semi‐structured interviews with 40 African students, I provide an account of the decision‐making processes that lead African student migrants to study in Chinese universities. The article explores how this process is mediated by global power asymmetries, specifically China's position within the (post)colonial world system relative to African nations. Four examples are given of student decision‐making processes which are shaped by structural inequalities, and challenge existing understandings of who moves overseas to study for a degree and to what ends. These are as follows: underprivileged students benefiting from China's political manoeuvring, students who are coerced into moving overseas, students who are middle class but not affluent by global standards, and elites who take advantage of social networks to secure diplomatic scholarships.
Two successive occasions resubmitted sampling scheme‐based control chart
Authors: Arshad Asma , Azam Muhammad , Aslam Muhammad
Published: October 2020

In this paper, a resubmitted sampling‐based successive sampling over two successive occasions control chart is proposed to monitor the underlying characteristic of interest. Auxiliary information of the first occasion is utilized to monitor the relative change in the study variable over the second occasion successively despite high degree of correlation. The structural and operational design is presented along with the comparative performance evaluation. The average run length is used as a performance evaluation measure and proved the argument in favor of the presented concept in comparison with the other auxiliary data control charts. The implementation is explained through two real examples.
Control chart to monitor circular data
Authors: Lima–Filho Luiz M. A. , Bayer Fábio M. , da Silva Augusto M.
Published: October 2020

This paper proposes a new Shewhart‐type control chart for circular or directional data. This type of data is found in several fields and applications, such as wind direction, the arrival time of a patient in a hospital, and the route of animals. The proposal is based on the Jones–Pewsey distribution, which is a very flexible three‐parameter distribution for modeling processes that can be represented as points on the circumference of the unit circle. We conduct an extensive Monte Carlo simulation study to evaluate and compare the performance of the proposed control chart with some competitors considering individual measurements and the mean direction (nonindividual observations). The results show that the Jones–Pewsey control chart outperforms the competitors in terms of run length distribution analysis. Finally, we present and discuss two applications based on actual datasets to show the applicability of the proposed control chart.
Exploring the metabolic phenotypes associated with different host inflammation of acute respiratory distress syndrome (ARDS) from lung metabolomics in mice
Authors: Yu Feng , Zhu Jing , Lei Ming , Wang Chuan‐jiang , Xie Ke , Xu Fang , Lin Shi‐hui
Published: October 2020

Rationale

The aim of this study was to analyze the metabolomics of lung with different host inflammation of acute respiratory distress syndrome (ARDS) for the identification of biomarkers for predicting severity under different inflammatory conditions.

Methods

Cecal ligation and puncture (CLP) and lipopolysaccharide (LPS)‐intratracheal injection induced acute lung injury (ALI) were used. A mouse model was used to explore lung metabolomic biomarkers in ALI/ARDS. The splenectomy model was used as an auxiliary method to distinguish between hyper‐ and hypo‐inflammatory subtypes. Plasma, lung tissue and bronchoalveolar lavage fluid (BALF) samples were collected from mice after CLP/LPS. The severity of lung injury was evaluated. Expression of tumor necrosis factor‐α (TNF‐α) in mice serum and lung was tested by enzyme‐linked immunosorbent assay (ELISA) and polymer chain reaction (PCR). Polymorphonuclear cells in BALF were counted. The lung metabolites were detected by gas chromatography/mass spectrometry (GC/MS), and the metabolic pathways predicted using the KEGG database.

Results

The LPS/CLP‐Splen group had more severe lung injury than the corresponding ALI group; that in the CLP‐Splen group was more serious than in the LPS‐Splen group. TNF‐α expression was significantly elevated in the serum and lung tissue after LPS or CLP, and higher in the LPS/CLP‐Splen group than in the corresponding ALI group. The level of TNF‐α in the CLP‐Splen group was elevated significantly over that in the LPS‐Splen group. Both these groups also showed significant neutrophil exudation within the lungs. During differential inflammation, more differential metabolites were detected in the lungs of the CLP group ALI mice than in the LPS group. A total of 41 compounds were detected in the lungs of the CLP and CLP‐Splen groups. Contrastingly, eight compounds were detected in the lungs of the LPS and LPS‐Splen groups. The LPS‐Splen and CLP‐Splen groups had significant neutrophil exudation in the lung. Random forest analysis of lung‐targeted metabolomics data indicated 4‐hydroxyphenylacetic acid, 1‐aminocyclopentanecarboxylic acid (ACPC), cis‐aconitic acid, and hydroxybenzoic acid as strong predictors of the hyper‐inflammatory subgroup in the CLP group. Furthermore, with splenectomy, 13 differential metabolic pathways between the CLP and LPS groups were revealed.

Conclusions

Hyper‐inflammatory subgroups of ARDS have a greater inflammatory response and a more active lung metabolism. Combined with the host inflammation background, biomarkers from metabolomics could help evaluate the response severity of ARDS.
Identification of the stable and reactive metabolites of tetrahydropiperine using ultrahigh‐performance liquid chromatography combined with diode‐array detection and high‐resolution mass spectrometry
Authors: Chen Xiaoling , Li Yanghua
Published: October 2020

Rationale

Tetrahydropiperine is one of the natural arylpentanamide compounds isolated from Piper nigrum L., which has been demonstrated to have insecticidal activity. The aim of this study was to investigate the metabolic profiles of tetrahydropiperine in mouse, rat, dog, monkey and human hepatocytes.

Methods

The in vitro metabolism of tetrahydropiperine was elucidated via incubation with hepatocytes for 2 h at 37°C. The samples were analyzed using ultrahigh‐performance liquid chromatography combined with diode‐array detection and high‐resolution tandem mass spectrometry operated in positive electrospray ionization mode. The structures of the metabolites were characterized using their retention times and their tandem mass spectrometric product ions.

Results

A total of 20 metabolites were detected and their structures were proposed. These metabolites were formed mainly through the following pathways: (1) 1,3‐benzodioxole ring opening to form a catechol derivative (M12), which was prone to glucuronidation (M6 and M8), methylation (M17) and glutathione (GSH)‐derived conjugation through an ortho‐quinone intermediate (M4) or via an aldehyde intermediate (M7); (2) dehydrogenation to form a piperanine (M15), which was subsequently subject to hydroxylation (M2 and M5) and GSH conjugation (M10 and M11) via Michael addition; (3) hydroxylation (M13, M14, M16, M18 and M19); and (4) direct GSH conjugation through an aldehyde intermediate (M3).

Conclusions

The major metabolic pathways of tetrahydropiperine were hydroxylation, dehydrogenation, methylation, GSH conjugation and glucuronidation. Tetrahydropiperine was bioactivated through ortho‐quinone, Michael receptor and aldehyde intermediates.
How to work with petroleum hydrocarbon suppliers to reduce and eliminate contaminated site management and cleanup requirements
Authors: Guerin Turlough
Published: October 2020

Petroleum hydrocarbon suppliers affect a mine's goals for environmental performance because of the extensive reach of petroleum hydrocarbon products into the mining and minerals product life cycle, their impact on operational efficiencies, cost, and mine viability, and their potential for leaving negative environmental as well as safety legacies. The supplied petroleum hydrocarbon life cycle is a framework that enables structured engagement between supplier and customer on a range of environmental performance issues because it is an example of input into the mining industry that affects the entire mining and minerals processing value chain. Engagement with suppliers in a proactive manner can be a risk management strategy. Questions for businesses to ask in relation to suppliers and their role in minimizing business risks and creating new value are offered.
A multiuser decoder based on spectrum analysis for the Brazilian Environmental Data Collecting System
Authors: Duarte José Marcelo L. , de Lima Raffael S. C. G. , Ramos Vítor S. , de Carvalho Manoel J. M.
Published: October 2020

The Brazilian Environmental Data Collection System (SBCDA) is an asynchronous multiuser message forwarding system based on low earth orbit (LEO) satellites with applications restricted to environmental monitoring and human life protection. This work presents a multiuser SBCDA decoder with low data memory and computational load. The decoder uses spectrum analysis to detect signal presences and upon every signal detection starts a signal decoding process with single‐user bit detection. Simulations considering an Additive White Gaussian Noise (AWGN) scenario with signal's time‐frequency positions uniformly and independently distributed and signal's powers uniformly distributed in dB within a dynamic range of 24 dB are present for different densities of user signals. Those show a frame error rate (FER) of approximately 25% for an average of six coexisting signals at every time instant, in which a missed signal was considered as a frame error. Finally, there are considerations on how to improve the performance maintaining a single‐input and single‐user bit detection strategy.
Morita‐Baylis‐Hillman Reaction Accessing GABA Intermediates: Synthesis of New Lipophilic Hydroxylated γ‐Nitroesters
Authors: Oliveira Rodrigues Marieli , Ramiro Sobral Felipe , Da Ros Montes D'Oca Caroline , Russowsky Dennis , Montes D'Oca Marcelo G.
Published: October 2020

The Morita‐Baylis‐Hillman (MBH) reaction has attracted great attention to generate densely functionalized adducts with promising synthetic utility and biological activities. In this work we demonstrate, for the first time, the synthesis of a series of new lipophilic hydroxylated α‐alkyl γ‐nitroesters, advanced γ‐aminobutyric acid (GABA) intermediates, using the Morita‐Baylis‐Hillman (MBH) reaction as key step. The results show that the long‐chain MBH adducts can be synthesized in good yields in a metal‐free organocatalytic system in the presence of aliphatic aldehydes and activated alkenes, acrylonitrile or methyl acrylate. Followed, the Michael addition of nitromethane to MBH adducts resulted in hydroxylated α‐alkyl γ‐nitroesters in good yields. Thus, the key MBH reaction led to new lipophilic GABA advanced intermediates in good overall yields from aliphatic aldehydes, demonstrating the potential of this reaction pathway towards the synthesis of new drug molecules for the treatment of psychiatric or neurodegenerative disorders.
Effects of Activation Process on Catkin Derived Carbon Materials and Its Electrochemical Performance as Matrix in Cathode of Li‐S Battery
Authors: Yan Yinglin , Chen Shiyu , Fan Chaojiang , Lin Jiaming , Fan Hua , Feng Zufei , Wang Juan , Xu Yunhua , You Caiyin , Yang Rong
Published: October 2020

Willow catkin was selected as raw material to fabricated carbon matrix in cathode of lithium‐sulfur (Li−S) battery due to its unique tubular morphology. The effects of activation time on the microstructure and electrochemical properties were investigated. The direct pyrolysis product inherited the tube‐like morphology. After activated by KOH under high temperature once, the microtubes were shorten and pressed as ribbon‐like. Meanwhile abundant micropores were formed in the tube wall. Further activatated the product twice, the original tube‐like microstructure was collapsed. Thus the results demonstrated that extending the activation time greatly affected the microstructure of carbon product. Furthermore, the sample activated once exhibited the largest specific surface area of 2033.09 m2 g−1 and the largest sulfur loading ratio (71.1 %). Moreover, the suitable activated sample exhibited the highest specific discharge capacity (1365.8 mAh g−1) and the best cycling performance. Consequently, the activation process played an important role in the microstructure and electrochemical performance of catkin derived carbon matrix in Li−S battery.
[2,3‐Bis‐(2‐pyridyl) pyrazine] as an Efficient Organocatalyst for the Direct C(sp2)‐H Arylation of Unactivated Arenes/Heteroarenes via C−H Bond Activation
Authors: Tiwari Mohit K. , Yadav Lalit , Chaudhary Sandeep
Published: October 2020

Herein, we report the identification of 2,3‐bis‐(2‐pyridyl) pyrazine as a new organocatalyst, which has been utilized for the direct cross‐coupling reactions of an aryl halide with unactivated arenes/heteroarenes via C(sp2)‐H bond activation. This transition metal‐free C−H arylation of unactivated benzenes with aryl halides (Ar−X; X=I, Br, Cl) underwent smoothly with only 10 mol% of an organocatalyst and in the presence of 3 equivalent of potassium tert‐butoxide base which furnished a library of biaryls (3 a–u) in up to 98 % excellent yield under milder reaction conditions. The mechanistic pathway involves the in‐situ formation of aryl radical anion intermediate and progressed via a single electron transfer (SET) mechanism. The wide substrate scope, high functional group forbearance, control/competition experiments, gram‐scale synthesis and kinetic studies signify the prominence and useful nature of the protocol along with the steadiness of the novel organocatalyst.
Improved Photocatalytic Activity of g‐C3N4/ZnO: A Potential Direct Z‐Scheme Nanocomposite
Authors: Ramachandra Madhushree , Devi Kalathiparambil Rajendra Pai Sunaja , Resnik Jaleel UC Jadan , Pinheiro Dephan
Published: October 2020

In this study, a Z‐scheme g‐C3N4/ZnO nanocomposite was synthesized using exfoliation process, which was further characterized using XRD, FT‐IR, UV‐DRS, SEM‐EDAX, PL, EIS, and TGA techniques. The properties of g‐C3N4 were enhanced when fabricated with ZnO resulting in a better electron mobility, high redox potential, and excellent semiconducting properties. The performance of this heterostructure was evaluated by photocatalytic degradation of malachite green (MG) under visible light irradiation. The g‐C3N4/ZnO heterostructure achieved a degradation of 84.3 % within 60 min under visible light irradiation. The degradation reaction follows a pseudo first‐order kinetic model with a reaction rate constant of 0.0329 min−1. The nanocomposite demonstrated outstanding stability and recyclability.
Multifunctional Cathodic Interlayer with Polysulfide Immobilization Mechanism for High‐Performance Li‐S Batteries
Authors: Waqas Muhammad , Manzoor Soomro Afaque , Ali Shamshad , Kumar Suresh , Chan Sattar , Hussain Kashif , Hussain Memon Fida , Ahmed Shaikh Shoaib
Published: October 2020

A highly efficient multifunctional polyvinylidene fluoride//carbon‐molybdenum disulfide (PVDF//C‐MoS2) interlayer is developed by direct deposition on sulfur cathode through facile slide coating method for Li−S batteries. The as‐developed PVDF//C–MoS2 interlayer exhibits the polysulfide adsorption and trapping capabilities, which reduces the shuttling effects and also slows down the self‐discharge in Li−S batteries. The first composite layer (C‐MoS2) on the cathode maximizes the level of lithium polysulfide adsorption owing to the strong dipolar interaction of Mo−S on the polarized surface of polysulfide species. Moreover, the PVDF layer physically traps/capture the remaining polysulfide species with its interconnected microstructure for the reutilization as active material in the cathode. The Li−S batteries based on interlayers deliver the discharge capacity of 1086 mAh g−1 at 1 C with 3.0 mg cm−2 sulfur loading and show capacity decay of 0.04 % per cycle after 1500 cycles. In contrast, the Li−S batteries without interlayer merely maintain the discharge capacities of 423 mAh g−1 at 1 C with 3.0 mg cm−2 sulfur loading and show severe capacity decay (0.12 %) after 505 cycles. The Li−S batteries also depict the remarkable cyclic performances with as‐developed interlayer for high sulfur loading cathodes and efficiently slowdowns the self‐discharge even after resting for a long time.
Evolution of Sulfides in Nonoriented Silicon Steels during Heating Process
Authors: Liu Chang , Luo Yan , Zhang Lifeng , Ren Qiang , Ren Ying
Published: October 2020

The evolution of sulfides in nonoriented silicon steels during the heating process is investigated through chemical composition analysis and thermodynamic calculation. Evolution behaviors of sulfides are analyzed using field emission scanning electron microscope (FESEM) and automatic scanning electron microscope (ASPEX). A homogeneous complex sulfide is detected containing magnesium and manganese. The different proportions of MgS and MnS in the complex sulfide are due to the competition between Mg, Mn, and S in low‐sulfur steel. Sulfides and compounds containing sulfides, oxides, and nitrides are mainly formed during the heating temperature of 1000 °C. The presence of sulfides and compounds with sulfide and oxide is at the temperature of 1300 °C. Sulfides reach equilibrium in less time than AlN at 1000 °C, while the time for sulfides to reach the theoretical equilibrium value takes precedence over oxides at 1300 °C. In addition, the proportions of various types of precipitation at 1300 and 1000 °C are discussed through the theoretical calculation and the observation results.
Optimal Silver Nitrate Concentration to Inhibit α‐Amylase Activity During Pasting of Rice Flour
Authors: Rahman Sayedur , Khoddami Ali , Copeland Les , Atwell Brian J. , Roberts Thomas H.
Published: October 2020

Endogenous α‐amylase interferes with accurate determination of the pasting properties of cereal flour. Silver nitrate (AgNO3) solutions at seven different concentrations (0.001‐0.1 m) plus a deionized water (dH2O) control are compared for their ability to inhibit α‐amylase activity during gelatinization of rice flour with medium to high amylose content (AC). Pasting properties are assessed using a Rapid Visco Analyzer (RVA). The optimal concentration of AgNO3 to inhibit α‐amylase in the flour of rice cultivar Doongara during gelatinization is 1% (w/v) (≈0.06 m). This concentration is tested further in three other types of rice for confirmation of the effects on RVA pasting properties. Peak viscosity is significantly higher using 1% AgNO3 than in the dH2O control, while breakdown and pasting temperature are significantly lower. In conclusion, the incorporation of 1% (w/v) AgNO3 into samples for RVA inhibits the α‐amylase activity in rice flour with medium to high AC, allowing pasting properties to be accurately measured using an RVA.
COVID‐19, physical (in‐)activity, and dementia prevention
Authors: Müller Patrick , Achraf Ammar , Zou Liye , Apfelbacher Christian , Erickson Kirk I. , Müller Notger G.
Published: October 2020

Physical inactivity is one major modifiable risk factor for dementia (especially Alzheimer's disease). Due to contact restrictions and isolation measures in response to the current COVID‐19 (coronavirus disease 2019) pandemic, physical inactivity levels have increased by up to 30%, which will likely have adverse consequences for primary and secondary dementia prevention. Therefore, new interdisciplinary prevention approaches (eg, outdoor exercise; app‐based exercise with online partners) are urgently needed that account for the suspected long‐term lifestyle changes that the current—and upcoming—pandemics are likely to entail (increased use of home office, social isolation, avoidance of fitness centers and club sports, and so on).
Safety, pharmacokinetics, and pharmacodynamics of Gln‐1062, a prodrug of galantamine
Authors: Bakker Charlotte , van der Aart Jasper , Hart Ellen P. , Klaassen Erica S. , Bergmann Kirsten R. , van Esdonk Michiel J. , Kay Denis G. , Groeneveld Geert Jan
Published: October 2020

Introduction

Gln‐1062 (MEMOGAIN) is an intranasally administered lipophilic prodrug of galantamine. Based on high brain‐to‐blood concentrations observed in pre‐clinical studies, Gln‐1062 is expected to have superior cognitive efficacy compared to oral galantamine.

Methods

Forty‐eight healthy elderly subjects were randomized 12:4 to Gln‐1062 (5.5, 11, or 22 mg, b.i.d., for 7 days) or placebo. Safety, tolerability, pharmacokinetics, and pharmacodynamics were assessed repeatedly. Pharmacokinetics were compared with 16 mg oral galantamine.

Results

Gln‐1062 up to 22 mg, b.i.d., was well tolerated. Gln‐1062 plasma concentrations increased immediately following dosing (median Tmax of 0.5 hour [range 0.5‐1.0]). Cmax and AUC0‐last increased in a dose‐linear manner over all three dose levels. Gln‐1062 was rapidly cleaved into galantamine. Gln‐1062 significantly improved adaptive tracking (sustained attention) with 1.95% (95% confidence interval [CI] 0.630‐3.279, P = 0.0055) compared to placebo after correction for individual baseline performance.

Discussion

Gln‐1062 was considered to be safe and caused fewer gastrointestinal side effects than oral galantamine. Gln‐1062 behaved pharmacokinetically as expected and improved performance on cognitive tests.
A 3D Adenine‐based Cd‐MOF: Synthesis, Structure and Photoluminescent Sensing for an Aromatic Azo Compound
Authors: Liu Yang , Zhang Shi‐Ting , Wu Yan‐Bin , Li Wei , Yang Ying‐Qun
Published: October 2020

A new Cd‐MOF containing the nucleobase adenine and multicarboxylates, Cd2(tdc)2(1H‐ade)2(H2O) (H2tdc = 2,5‐thiophene carboxylic acid, 1H‐ade = adenine), was synthesized successfully under hydrothermal condition and characterized by single‐crystal X‐ray diffraction, infrared spectrum, thermogravimetric analysis and photoluminescence. The two crystallographically unsymmetrical Cd atoms are bridged by 2,5‐tdc ligands with (κ1‐κ1)‐(κ1)‐μ3 and (κ1–κ1)–μ2 modes into two dimensional extended layers, which are further pillared with the neutral ade molecules to form a 3D frameworks stabilized by extensive π···π interactions between imidazole‐, pyrimidine‐ and thiophene‐rings. Inspection of the structure reveals that the architecture can be simplified as a 3,4,5‐ connected networks with a Schläfli symbol of (62·8)(42·63·8)(42·65·83). The photochemical property shows that the luminescent emission can be significantly quenched by aromatic azo compounds. The quenching effect coefficient (Ksv) for bis(4‐imidazol‐1‐yl‐phenyl)diazene is determined to be 4.1 × 104 m–1, indicating the title compound as a potential fluorescent sensing materials.
Chemical Whiteness
Authors: Hardon Anita
Published: October 2020

Here we explore the chemical practice of skin whitening, a prevalent practice among young service sector workers in the Philippines and Indonesia. Chemical Whiteness investigates this problematic practice in everyday interactions, where people with darker skin are undervalued and those with lighter skin, which is considered pleasing to employers and clients, attain a higher value in the workplace. These workers are pressured to portray the good life they are selling to their clients, performing the “pleasing personality” that their companies want to associate with their services. To lighten their skin, our interlocutors apply range of expensive and often harmful products, often involving daily reapplication. While skin lightening is commonly associated with women, we discovered that in the Philippines, young men competing for positions in sales and customer service had also developed their own beauty routines with skin whitening products. While such practices are meant to increase young people’s worth in the service sector economy, like many other chemical practices explored in this book, they can lead to the further precarization of young people’s lives.
Chemical Supplementing
Authors: Hardon Anita
Published: October 2020

This chapter, Chemical Supplementing, presents ethnographies of young people who use a variety of supplements in order to optimize their health. In the Philippines, boys take multivitamins with the hope of increasing their height, reflecting the importance of stature in their society, and young professionals take expensive supplements to improve their stamina for their demanding distribution jobs in a multilevel marketing company. In fitness centers, young women use proteins and fortified shakes to achieve an idealized, lean, and muscular body. In health and vitamin stores in Amsterdam, growing numbers of young people are buying, sharing, and promoting their personal concoctions of proteins and vitamins. These supplementing practices stem from young people’s various needs: to respond to the demands of service sector labor, to recover from the strain of night work, to indulge in the pleasure of weekend raves, and to manage growing concerns about environmental toxins. By zooming in on supplementing practices of these different groups of young people, we get a clearer understanding of their shared sense of vulnerability, and of the need for better regulation of the supplements industry.
Spatializing Memory and Justice in Transformation Processes
Authors: Buckley-Zistel Susanne
Published: October 2020

This chapter asks what processes of dealing with the past have been set in motion and how they relate to the search for justice and the quest for remembrance on a more global scale. In the aftermath of the “Arab Spring,” the affected countries have been going through transitions of various forms that are significantly re-configuring the MENA region. In this context, a number of new civil society actors, political elites, and international norm entrepreneurs are engaging with the lengthy histories of repression in the respective countries as well as with the violence that occurred during the Arab Spring in order to reckon with the legacy of human rights abuses (Sriram, Transitional justice in the middle East and North Africa, Hurst, London, 2017). These transitions to justice are not without obstacles and challenges, though. The objective of her chapter is therefore not to tell the stories of various transitional justice and memory projects in post-Arab Spring countries, but to situate such practices in time and space.
ν electroweak baryogenesis
Authors: Fernández-Martínez E. , López-Pavón J. , Ota T. , Rosauro-Alcaraz S.
Published: October 2020

Abstract

We investigate if the CP violation necessary for successful electroweak baryo- genesis may be sourced by the neutrino Yukawa couplings. In particular, we consider an electroweak scale Seesaw realization with sizable Yukawas where the new neutrino singlets form (pseudo)-Dirac pairs, as in the linear or inverse Seesaw variants. We find that the baryon asymmetry obtained strongly depends on how the neutrino masses vary within the bubble walls. Moreover, we also find that flavour effects critically impact the final asymmetry obtained and that, taking them into account, the observed value may be obtained in some regions of the parameter space. This source of CP violation naturally avoids the strong constraints from electric dipole moments and links the origin of the baryon asymmetry of the Universe with the mechanism underlying neutrino masses. Interestingly, the mixing of the active and heavy neutrinos needs to be sizable and could be probed at the LHC or future collider experiments.