bluuebunny/crossref_metadata_2025 huggingface dataset:
Construction of 2D BiVO4−CdS−Ti3C2Tx Heterostructures for Enhanced Photo‐redox Activities
Authors: Wang Wuyou , Hood Zachary D. , Zhang Xuanyu , Ivanov Ilia N. , Bao Zhenghong , Su Tongming , Jin Mingzhou , Bai Lei , Wang Xuewen , Zhang Rongbin , Wu Zili
Published: April 2020

Photocatalytic evolution of hydrogen and oxygen from water splitting over semiconductors is an efficient method for solar energy conversion. In this study, the 2D/2D BiVO4−CdS heterostructures with Ti3C2Tx (Tx=O, OH, F) as a co‐catalyst were synthesized by two steps as the visible‐light‐driven photocatalysts. Compared with BiVO4 and CdS, the heterostructured catalysis exhibit greatly enhanced photocatalytic hydrogen and oxygen production performances and excellent photodegradation and photoreduction activities of methylene blue (MB) and potassium dichromate Cr(VI), respectively. The remarkable enhancement is attributed to the proposed Z‐scheme carrier transfer derived from the 2D/2D BiVO4−CdS heterostructures. Charge separation and transfer of photoexcited electrons and holes pairs are further enhanced after loading Ti3C2Tx in the BiVO4−CdS heterostructures. The potential Z‐scheme photocatalytic system and co‐catalyst endows the BiVO4−CdS−Ti3C2Tx heterostructures with strong photo‐redox capacity and excellent stability in solar energy conversion.
Unique Role of Heterole‐Fused Structures in Aromaticity and Physicochemical Properties of 7,8‐Dehydropurpurins
Authors: Higashino Tomohiro , Nishimura Issei , Imahori Hiroshi
Published: April 2020

Porphyrins with a fused five‐membered ring, such as 7,8‐dehydropurpurins, have appeared as an emerging class of unique porphyrinoids. Their altered absorption spectra, relatively short lifetimes of excited states, and small HOMO–LUMO gaps arise from the harmony of the antiaromatic 20π‐circuit and the aromatic 18π‐circuit. In this regard, the electronic properties of 7,8‐dehydropurpurins are expected to be controlled by modulating the contribution of the antiaromatic π‐circuit to the whole aromaticity. Here the comparison of pyrrole‐ and phosphole‐fused 7,8‐dehydropurpurins is reported in terms of their aromaticity and physicochemical properties. The spectroscopic investigation revealed the larger contribution of the antiaromatic 24π‐circuit in pyrrole‐fused 7,8‐dehyrdopurpurins than in phosphole‐fused 7,8‐dehydropurpurins. The DFT calculations also supported the feasibility of tuning the aromaticity of 7,8‐dehydropurpurins by heterole‐fused structures. Thus, the introduction of heterole‐fused structures into porphyrinoids is a universal strategy to get new insight into aromaticity and their intrinsic properties in cyclic π‐conjugated molecules.
Spectrum of PALB2 germline mutations and characteristics of PALB2‐related breast cancer: Screening of 16,501 unselected patients with breast cancer and 5890 controls by next‐generation sequencing
Authors: Zhou Jiaojiao , Wang Honglian , Fu Fangmeng , Li Zhanwen , Feng Qingjian , Wu Weizhu , Liu Yun , Wang Chuan , Chen Yiding
Published: April 2020

Background

Partner and localizer BRCA2 (PALB2) is a breast cancer predisposition gene, but the clinical relevance of PALB2 germline mutations in Chinese patients with breast cancer remains unknown. This study attempted to investigate the full prevalence and spectrum of PALB2 germline mutations in China and the associations between PALB2 germline mutations and breast cancer risk.

Methods

A total of 21,216 unselected patients with breast cancer were enrolled from 10 provinces in China, and 5890 Chinese women without cancer were enrolled as healthy controls. PALB2 screening was based on next‐generation sequencing.

Results

A total of 16,501 BRCA1/2‐negative patients with breast cancer were analyzed. Deleterious PALB2 mutation carriers accounted for 0.97% (n = 160) in the breast cancer cohort and for 0.19% (n = 11) in the healthy control cohort. Forty‐one novel PALB2 germline mutations were identified. A high frequency of PALB2 c.751C>T was detected, and it accounted for 10.63% of the PALB2 germline mutations detected (17 of 160). PALB2 mutations were significantly associated with increased breast cancer risk (odds ratio [OR], 5.23; 95% confidence interval [CI], 2.84‐9.65; P < .0001), especially among women 30 years old or younger (OR, 10.09; 95% CI, 3.95‐25.79; P < .0001). Clinical characteristics, including a family history, bigger tumor size, triple‐negative breast cancer, positive lymph nodes, and bilateral breast cancer, were closely related to PALB2 mutations.

Conclusions

This study revealed a comprehensive spectrum of PALB2 germline mutations and characteristics of PALB2‐related breast cancer in China. PALB2 germline mutations confer a moderately increased risk for breast cancer but profoundly increase breast cancer risk for those 30 years old or younger in the Chinese population.
Parallel performance of molecular dynamics trajectory analysis
Authors: Khoshlessan Mahzad , Paraskevakos Ioannis , Fox Geoffrey C. , Jha Shantenu , Beckstein Oliver
Published: April 2020

The performance of biomolecular molecular dynamics simulations has steadily increased on modern high‐performance computing resources but acceleration of the analysis of the output trajectories has lagged behind so that analyzing simulations is becoming a bottleneck. To close this gap, we studied the performance of trajectory analysis with message passing interface (MPI) parallelization and the PythonMDAnalysislibrary on three different Extreme Science and Engineering Discovery Environment (XSEDE) supercomputers where trajectories were read from a Lustre parallel file system. Strong scaling performance was impeded by stragglers, MPI processes that were slower than the typical process. Stragglers were less prevalent for compute‐bound workloads, thus pointing to file reading as a bottleneck for scaling. However, a more complicated picture emerged in which both the computation and the data ingestion exhibited close to ideal strong scaling behavior whereas stragglers were primarily caused by either large MPI communication costs or long times to open the single shared trajectory file. We improved overall strong scaling performance by either subfiling (splitting the trajectory into separate files) or MPI‐IO with parallel HDF5 trajectory files. The parallel HDF5 approach resulted in near ideal strong scaling on up to 384 cores (16 nodes), thus reducing trajectory analysis times by two orders of magnitude compared with the serial approach.
LSR‐forest: An locality sensitive hashing‐based approximate k‐nearest neighbor query algorithm on high‐dimensional uncertain data
Authors: Wang Jiagang , Qian Tu , Yang Anbang , Wang Hui , Qian Jiangbo
Published: April 2020

Uncertain data is widely used in many practical applications, such as data cleaning, location‐based services, privacy protection, and so on. With the development of technology, data has a tendency to high‐dimensionality. The most common indexes for nearest neighbor search on uncertain data are the R‐Tree and the KD‐Tree. These indexes will inevitably bring about “curse of dimension.” Focus on this problem, article proposes a new hash algorithm, called the LSR‐forest, which based on locality sensitive hashing and R‐Tree, to solve the high‐dimensional uncertain data approximate neighbor search problem. The LSR‐forest can hash similar high‐dimensional uncertain data into a same bucket with a high probability, and then constructs multiple R‐Tree‐based indexes for hashed buckets. When querying, it is possible to judge neighbors by checking the data in the hypercube which the query point is in. One can also adjust the query range automatically by different parameter of k. Many experiments on different datasets are presented in this article. The results show that LSR‐forest has better effectiveness and efficiency than R‐Tree on high‐dimensional datasets.
Kinetic Isotope Effect as a Tool To Investigate the Oxygen Reduction Reaction on Pt‐based Electrocatalysts – Part II: Effect of Platinum Dispersion
Authors: Rezaei Talarposhti Morteza , Asset Tristan , Garcia Samuel T. , Chen Yechuan , Herrera Sergio , Dai Sheng , Peterson Eric J. , Artyushkova Kateryna , Zenyuk Iryna , Atanassov Plamen
Published: April 2020

We investigated the oxygen reduction reaction (ORR) mechanism on Pt nanoparticles (NPs) dispersed on several carbon blacks with various physicochemical properties (i. e. specific surface ranging from 80 to 900 m2 g−1, different graphitization degree, etc.). Using the kinetic isotope effect (KIE) along with various electrochemical characterizations, we determined that the rate determining step (RDS) of the ORR is a proton‐independent step when the density of Pt NPs on the surface of the carbon support is high. Upon decrease of the density of Pt NPs on the surface, the RDS of the ORR starts involving a proton, as denoted by an increase of the KIE >1. This underlined the critical role played by the carbon support in the oxygen reduction reaction electrocatalysis by Pt supported on high surface area carbon.
Clathrate III (Bromine Hydrate): Structural Relationship with Clathrate I
Authors: Pomeransky Anatoly A.
Published: April 2020

Tetragonal structure of clathrate III (TS−I) is found in bromine hydrate, ionic hydrates, in particular, in hydrates of tetraalkylammonium salts, as well as in clathrate compounds of the group IV elements (‘Zintl clathrates’). In this paper new description of this clathrate structure is suggested. Main structural unit in this description is ‘4‐column’, the set of four nearest columns of 14‐hedral T‐cages together with its internal filling by the pillar of mutually orthogonal pairs of T‐cages. Comparison based on this new description of clathrate III and clathrate I (CS−I) shows that 4‐column is maximal common structural element of these two structures. On this ground it is argued that clathrate III can be considered as a modification of the clathrate I, formed as a result of multiple interruption of clathrate I crystal growth. At the same time, it is shown that due to crucial differences between these two structures there does not exist structural or reconstructive phase transition between them. Integral character of 4‐columns as the structural units of clathrate III is confirmed by the analysis of the most studied case of ionic hydrates of tetraalkylammonium salts in which guest molecules occupy simultaneously T‐cages in outer columns and inner T‐cages. This analysis allows also to state important hypothesis that in general case for formation of clathrate III crystals presence of special guest molecules occupying several cages (or special ions in the host lattice) is necessary.
Determination of Electronic Recombination Free Energy in Zeolites: Effects of the Charge Balancing Cation and Confinement
Authors: Hureau Matthieu , Moissette Alain , Gaillard Jérémy
Published: April 2020

The adsorption of DPH in M6.6ZSM‐5 (M=Na+, K+, Rb+, Cs+), RbFER and RbMOR channel zeolites takes place without chemical or structural modification. After photoexcitation of these systems, a radical cation–electron pair is observed and has a sufficiently long lifetime to be studied by diffuse reflectance UV‐visible spectroscopy. The study of the recombination of this radical cation‐electron pair was carried out at different temperatures and allowed the determination of the activation energy as a function of the nature of the charge‐balancing cation but also of the confinement effect. It appears that the activation energy decreases progressively from Na+ to Cs+ but also when the confinement decreases. To go further, the free enthalpies have been calculated from the Marcus theory demonstrating experimentally that these systems are located in the inverted Marcus region.
Functionalized Macrocycles in Supramolecular Organocatalysis
Authors: Kauerhof Dana , Niemeyer Jochen
Published: April 2020

Supramolecular organocatalysis has emerged as a novel research field in the context of homogeneous catalysis. In particular, the use of functionalized macrocycles as supramolecular catalysts is highly promising, as these systems are oftentimes easily accessible and offer distinct advantages in catalysis. Macrocyclic catalysts can provide defined binding pockets, such as hydrophobic cavities, and can thus create a reaction microenvironment for catalysis. In addition, macrocycles can offer a preorganized arrangement of functional groups, such as binding sites or catalytically active groups, thus enabling a defined and possibly multivalent binding and activation of substrates. The aim of this Minireview is to provide an overview of recent advances in the area of supramolecular organocatalysis based on functionalized macrocycles (including cyclodextrins, calixarenes, and resorcinarenes), with a focus on those examples where certain catalytically active groups (such as hydrogen bond donors/acceptors, Brønsted acid or base groups, or nucleophilic units) are present in or have been installed on the macrocycles.
Two‐Step Preparation of Highly Pure, Soluble HIV Protease from Inclusion Bodies Recombinantly Expressed in Escherichia coli
Authors: Sherry Dean , Worth Roland , Sayed Yasien
Published: April 2020

Heterologous expression of exogenous proteases in Escherichia coli often results in the formation of insoluble inclusion bodies. When sequestered into inclusion bodies, the functionality of the proteases is minimized. To be characterized structurally and functionally, however, proteases must be obtained in their native conformation. HIV protease is readily expressed as inclusion bodies, but must be recovered from the inclusion bodies. This protocol describes an efficient method for recovering HIV protease from inclusion bodies, as well as refolding and purifying the protein. HIV protease–containing inclusion bodies are treated with 8 M urea and purified via cation‐exchange chromatography. Subsequent refolding by buffer exchange via dialysis and further purification by anion‐exchange chromatography produces highly pure HIV protease that is functionally active. © 2020 by John Wiley & Sons, Inc.

Basic Protocol: Recovery, refolding, and purification of HIV protease from inclusion bodies

Support Protocol 1: Expression and extraction of inclusion bodies containing HIV protease expressed in Escherichia coli

Support Protocol 2: Determination of the active site concentration of HIV protease via isothermal titration calorimetry
Selective Electrocatalytic Oxidation of Biomass‐Derived 5‐Hydroxymethylfurfural to 2,5‐Diformylfuran: from Mechanistic Investigations to Catalyst Recovery
Authors: Kisszekelyi Peter , Hardian Rifan , Vovusha Hakkim , Chen Binglin , Zeng Xianhai , Schwingenschlögl Udo , Kupai Jozsef , Szekely Gyorgy
Published: April 2020

The catalytic transformation of bio‐derived compounds, specifically 5‐hydroxymethylfurfural (HMF), into value‐added chemicals may provide sustainable alternatives to crude oil and natural gas‐based products. HMF can be obtained from fructose and successfully converted to 2,5‐diformylfuran (DFF) by an environmentally friendly organic electrosynthesis performed in an ElectraSyn reactor, using cost‐effective and sustainable graphite (anode) and stainless‐steel (cathode) electrodes in an undivided cell, eliminating the need for conventional precious metal electrodes. In this work, the electrocatalysis of HMF is performed by using green solvents such as acetonitrile, γ‐valerolactone, as well as PolarClean, which is used in electrocatalysis for the first time. The reaction parameters and the synergistic effects of the TEMPO catalyst and 2,6‐lutidine base are explored both experimentally and through computation modeling. The molecular design and synthesis of a size‐enlarged C3‐symmetric tris‐TEMPO catalyst are also performed to facilitate a sustainable reaction work‐up through nanofiltration. The obtained performance is then compared with those obtained by heterogeneous TEMPO alternatives recovered by using an external magnetic field and microfiltration. Results show that this new method of electrocatalytic oxidation of HMF to DFF can be achieved with excellent selectivity, good yield, and excellent catalyst recovery.
A high‐resolution all‐digital pulse‐width modulator architecture with a tunable delay element in CMOS
Authors: Morales Juan Ignacio , Chierchie Fernando , Mandolesi Pablo Sergio , Paolini Eduardo Emilio
Published: April 2020

A design for an all‐digital high‐resolution pulse‐width modulator (HRPWM) architecture is presented in this work. The architecture is based on a novel digitally controlled delay element that combines two different approaches, achieving a variable time interval up to 54 ps, and adjustable against process, voltage, and temperature (PVT) variations. The proposed system uses several delay elements with a counter‐based digital pulse‐width modulator (DPWM) in a hybrid configuration, which allows to obtain duty cycles with 18‐bit resolution without using a high‐frequency internal clock and maintaining a low power dissipation.

The HRPWM was implemented in a standard low‐cost 130‐nm CMOS technology, together with a memory used to store the duty cycles, and a serial communication module. Post layout simulation results show good linearity between the control word and the duty cycle in all the range. The chip can be fine tuned to improve its performance using the calibration capabilities of the architecture. The analysis includes a comparison with another state‐of‐art HRPWMs showing the advantages of the proposed approach.
Flow Cytometric Monitoring of Dynamic Cytosolic Calcium, Sodium, and Potassium Fluxes Following Platelet Activation
Authors: Aliotta Alessandro , Bertaggia Calderara Debora , Alberio Lorenzo
Published: April 2020

The interaction of platelet agonists with their respective membrane receptors triggers intracellular signaling, among which cytosolic ion fluxes play an important role in activation processes. While the key contribution of intercellular free calcium is accepted, sodium and potassium roles in platelet activation have been less investigated in recent studies. Here, we implemented a novel flow‐cytometric method to monitor over time cytosolic free calcium, sodium, and potassium ion fluxes upon platelet activation and we demonstrate the feasibility of real‐time visualization of ion kinetics, in particular with a focus on sodium and potassium. Platelets were loaded with selective ion indicators, Fluo‐3 (Ca2+), ION NaTRIUM Green‐2 (Na+), and ION Potassium Green‐2 (K+). Fluorescence was monitored by flow cytometry. After measurement of a stable baseline, platelets were activated and ion indicator fluorescence was acquired over time, up to 10 min. Platelets were activated with either thromboxane analogue U46619, ADP, thrombin, TRAP6 (PAR‐1 agonist), AYPGKF (PAR‐4 agonist), convulxin (collagen receptor GPVI agonist), or combinations thereof. We evaluated preanalytical parameters (in particular dye loading time and concentration) to implement an accurate method. Subsequently, we characterized cytosolic calcium, sodium, and potassium kinetics in response to platelet agonists. We observed different patterns of agonist synergism. In conclusion, the present work highlights the use of cytosolic ion monitoring by flow cytometry to investigate characteristic calcium, sodium, and potassium mobilization patterns following platelet activation. This easy technique opens a new way to analyze signaling in different platelet subpopulations and it should prove useful for investigating platelet pathophysiology. © 2020 International Society for Advancement of Cytometry
Enhancing the spectral efficiency and energy efficiency of underwater channel communication by optimal cooperative spectrum sensing using hybrid optimization
Authors: Umamaheshwararao Sanapala , Kumar Muvvala Naga Venkata Siva Santosh , Ramarakula Madhu
Published: April 2020

Underwater wireless sensor networks (UWSNs) contain quite a lot of components such as vehicles and sensors that are deployed in a specific acoustic area to perform collaborative monitoring and data collection errands. These networks are adopted interactively between diverse nodes and ground‐based stations. Currently, UWSNs face problems and challenges that pertain to limited bandwidth, media access control, high propagation delay, 3D topology, spectrum sensing, resource utilization, routing, and power constraints. This proposal deals with the intelligent spectrum sensing in underwater cognitive sonar communication networks (CSCN). Here, the improved performance of spectrum sensing in underwater communication is attained by optimizing the cooperative spectrum sensing and data transmission. The parameters of system like subchannel allocation and transmission power is optimized by a new hybrid meta‐heuristic algorithm by integrating the concepts of deer hunting optimization algorithm (DHOA) and lion algorithm (LA) termed as lion‐enabled DHOA (L‐DHOA). The main intention of optimizing these parameters is to maximize the spectrum efficiency (SE) and energy efficiency (EE) of the underwater channel communication system. From the analysis, with respect to convergence rate, minimum detection probability, and local sensing time, it is proved that the novel hybrid optimization algorithm keeps a great role in making the trade‐off between the SE and EE in underwater channel modeling.
Develop hard skills for successful deanship
Authors: Hodges Dawn Z.
Published: April 2020

Before I was a chief academic officer, I was a dean for 12 years. At different times, and at various colleges, I was dean of arts and sciences, academic support, an evening and weekend college, and the main campus of a multi‐campus college. One thing is for certain: There is an important skill set necessary for a successful deanship.
Foster diversity, inclusion with intentional practices and recruitment
Authors: Sutton Halley
Published: April 2020

Inclusion and diversity might not be the two things you think of right away when you think of a university in Minnesota, but if it were up to Jean Haar, Ph.D., Dean of Education at Minnesota State University, Mankato, they would be the first things. When Haar was first hired at Mankato in 2002, the president of the university was intentionally investing in expanding diversity and inclusion on campus. It was a mission Haar took up with vigor, looking to shift her department's mission to be more diverse, inclusive, and social justice–oriented.
The importance of street trees to urban avifauna
Authors: Wood Eric M. , Esaian Sevan
Published: April 2020

Street trees are public resources planted in a municipality’s right‐of‐way and are a considerable component of urban forests throughout the world. Street trees provide numerous benefits to people. However, many metropolitan areas have a poor understanding of the value of street trees to wildlife, which presents a gap in our knowledge of conservation in urban ecosystems. Greater Los Angeles (LA) is a global city harboring one of the most diverse and extensive urban forests on the planet. The vast majority of the urban forest is nonnative in geographic origin, planted throughout LA following the influx of irrigated water in the early 1900s. In addition to its extensive urban forest, LA is home to a high diversity of birds, which utilize the metropolis throughout the annual cycle. The cover of the urban forest, and likely street trees, varies dramatically across a socioeconomic gradient. However, it is unknown how this variability influences avian communities. To understand the importance of street trees to urban avifauna, we documented foraging behavior by birds on native and nonnative street trees across a socioeconomic gradient throughout LA. Affluent communities harbored a unique composition of street trees, including denser and larger trees than lower‐income communities, which in turn, attracted nearly five times the density of feeding birds. Foraging birds strongly preferred two native street‐tree species as feeding substrates, the coast live oak (Quercus agrifolia) and the California sycamore (Platanus racemosa), and a handful of nonnative tree species, including the Chinese elm (Ulmus parvifolia), the carrotwood (Cupaniopsis anacardioides), and the southern live oak (Quercus virginiana), in greater proportion than their availability throughout the cityscape (two to three times their availability). Eighty‐three percent of street‐tree species (n = 108, total) were used in a lower proportion than their availability by feeding birds, and nearly all were nonnative in origin. Our findings highlight the positive influence of street trees on urban avifauna. In particular, our results suggest that improved street‐tree management in lower‐income communities would likely positively benefit birds. Further, our study provides support for the high value of native street‐tree species and select nonnative species as important habitat for feeding birds.
Local adaptation to UV radiation in zooplankton: a behavioral and physiological approach
Authors: Fernández Carla E. , Campero Melina , Bianco Giuseppe , Ekvall Mikael T. , Rejas Danny , Uvo Cintia B. , Hansson Lars‐Anders
Published: April 2020

Ultraviolet radiation (UVR) is recognized as a driving force for phenotypic divergence. Here, we aim at assessing the ability of zooplankton to induce UVR tolerance and disentangle the relative importance of local adaptations behind the expression of such tolerance. Two populations of Daphnia pulex, derived from environments strongly differing in UVR conditions, were exposed to UVR for 70 d to induce production of photo‐protective compounds and changes in behavioral responses. We expected greater tolerance to UVR in individuals from the high‐UVR (H‐U) environment as well as a refuge demand inversely related to the level of pigmentation. However, the complementarity between physiological and behavioral strategies was only observed on animals from the Low‐UVR environment (L‐U). L‐U animals developed photo‐protective compounds and decreased their refuge demand when re‐exposed to UVR, that is, tolerated more UVR, compared to their control siblings. Conversely, UVR‐exposed individuals from the H‐U environment even having developed higher levels of photo‐protective compounds increased their refuge demand staying deeper in the water column compared to the control animals, likely expressing an evolutionary memory to seek refuge in deeper waters irrespective of the UVR level. Stronger changes were observed in the H‐U population compared to the L‐U population; thus, our results suggest that although changes in tolerance after UVR exposure were evident for both populations, the strength of the inductions was more related to local adaptation independently of the rearing environment, showing that UVR tolerance is dependent on the evolutionary history of each population.
Synthesis, Crystal Structure and Photoelectric Response of All‐Inorganic Copper Halide Salts CsCuCl3
Authors: Cui Shuting , Chen Yan , Tao Siwen , Cui Jiawen , Yuan Cang , Yu Ning , Zhou Huawei , Yin Jie , Zhang Xianxi
Published: April 2020

Metal halide salts have attracted widespread attention because of their good physical and chemical properties. In this study, lead‐free copper halide salt CsCuCl3 single crystals and photodetectors were prepared. According to the single crystal diffraction data, the CsCuCl3 single crystal has a hexagonal structure with P6522 (179) space group (7.2399 × 7.2399 × 18.3096 Å, 90.000 × 90.000 × 120.000). The crystal structure along the z‐axis is a double‐stranded helix structure. To the best of our knowledge, this is the first study on CsCuCl3 for optoelectronic applications. The CsCuCl3 photodetector exhibits high light response, sensitivity, and selectivity under 369 nm ultraviolet light and invalid response for visible light (511 nm). The device based on CsCuCl3 is highly selective for ultraviolet light (2.43 µA/mW) and feature high anti‐interference of visible light (0.0119 µA/mW). The device has the strongest selectivity at 369 nm light, which is 200 times higher than that at 511 nm. The results will be of interest for applications in photodetectors, LEDs, devices, and metal halide salts.
The Coordination Chemistry of the Phosphanylborane (C6H5)2PBH2·N(CH3)3 towards Copper(I) Salts
Authors: Elsayed Moussa Mehdi , Braese Jens , Marquardt Christian , Seidl Michael , Scheer Manfred
Published: April 2020

The reactions of the phosphinoborane Ph2PBH2·NMe3 with Cu(I) halides [CuCl, CuBr, CuI] and [Cu(CH3CN)4BF4], respectively, were studied. Depending on the ratio of the reactants used, the former reaction allowed for the synthesis of eight neutral coordination compounds with the general formula [CunXn(Ph2PBH2·NMe3)m] (X = Cl, Br, I; n = 1, 2, 4, 5; m = 2, 4) (4–11). The latter reaction, however, led to the formation of the homoleptic complex [Cu(Ph2PBH2·NMe3)3][BF4] (13). The structures of the products 4–11 and 13 were compared to related complexes possessing the well‐known Ph3P ligand. All compounds were characterized by single crystal X‐ray structure analysis, multinuclear NMR spectroscopy, IR spectroscopy and mass spectrometry.
Synthesis of 2‐Aminoquinazoline‐ and 2‐Aminopyrimidine‐Fused Hybrid Scaffolds by Copper‐Catalyzed C(sp2)–N Coupling and Cyclization Followed by Oxidation
Authors: Kwak Jung Pyo , Dao Pham Duy Quang , Cho Chan Sik
Published: April 2020

2‐(2‐Bromoaryl)‐ and 2‐(2‐bromovinyl)‐4,7‐dimethoxybenzimidazoles are coupled and cyclized with cyanamide as a building block in dimethylformamide in the presence of a catalytic amount of a copper catalyst along with a base to give the corresponding 2‐aminoquinazoline‐ and 2‐aminopyrimidine‐fused 4,7‐dimethoxybenzimidazoles in good yields. Subsequent oxidation of such N‐fused hybrid scaffolds by treatment of ceric ammonium nitrate in acetonitrile/H2O affords unprecedented 2‐aminoquinazoline‐ and 2‐aminopyrimidine‐fused benzimidazolequinones.
COVID‐19: A great disruptor?
Authors: Dennis Marguerite J.
Published: April 2020

By the end of January, the World Health Organization had declared COVID‐19 a “global health emergency.”
Even in global city, extra effort needed to attract international students
Authors: Enos Gary
Published: April 2020

Washington, D.C.’s prominence as a global community carries clear advantages for Andrea Felder, Ed.D., in her role of attracting international students to attend American University. Still, Felder has worked to mobilize any resources at her disposal to help communicate that the campus will be a welcoming place for those who arrive.
Aggregation‐induced emission luminogen: A new perspective in the photo‐degradation of organic pollutants
Authors: Hu Zhen , Li Ying , Kang Miaomiao , Islam Md. Monarul , Chen Mengsi , Zhang Jun , Xiao Ye , Feng Xing , Redshaw Carl , Zhang Menglong , Chen Qing , Xie Sheng , Lam Jacky W. Y. , Tang Ben Zhong
Published: April 2020

Both the variety and uniqueness of organic semiconductors has contributed to the rapid development of environmental engineering applications and renewable fuel production, typified by the photodegradation of organic pollutants or water splitting. This paper presents a rare example of an aggregation‐induced emission luminogen as a highly efficient photocatalyst for pollutant decomposition in an environmentally relevant application. Under irradiation, the tetraphenylethene‐based AIEgen (TPE‐Ca) exhibited high photo‐degradation efficiency of up to 98.7% of Rhodamine B (RhB) in aqueous solution. The possible photocatalytic mechanism was studied by electron paramagnetic resonance and X‐ray photoelectron spectroscopy spectra, electrochemistry, thermal imaging technology, ultra‐performance liquid chromatography and high‐definition mass spectrometry, as well as by density functional theory calculations. Among the many diverse AIEgens, this is the first AIEgen to be developed as a photocatalyst for the degradation of organic pollutants. This research will open up new avenues for AIEgens research, particularly for applications of environmental relevance.

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Experimental investigation of a compressed air vehicle prototype with phase change materials for heat recovery
Authors: Evrin Reza Alizade , Dincer Ibrahim
Published: April 2020

In this article, an experimental investigation, where the prototype of a new pneumatic vehicle is developed, analyzed, built and tested, is presented. The system consists of a novel compressed air system integrated with phase change materials for heat recovery purposes. The prototype is experimentally built and tested at the Ontario Tech. University in Oshawa. Three different phase change materials of polyethyleneglycol, paraffin and alkane mix are investigated for heat recovery purposes in the prototype where the paraffin option provides the best result. Furthermore, the maximum torque is found to vary between 21 and 44 Nm with changing shaft speed from 400 to 1300 rpm while the minimum torque fluctuates between 3 and 13 Nm with changing shaft speed in the same range. The supplementary battery power is 2.18 kW, and the turbine work output is found to be 1.25 kW with the recovered air which is provides 36% of the heat required to heat up the PCM heat exchanger. The total motor work consumed during operation is 18.36 kW, which can be defined as the acceptable capacity for the powertrain of a small‐size city vehicle. The energetic efficiency for the compressed air vehicle is 59.5% while the exergetic efficiency becomes 51.0%, respectively.
A revisit to the hedge and safe haven properties of gold: New evidence from China
Authors: Ming Lei , Zhang Xinran , Liu Qianqiu , Yang Shenggang
Published: April 2020

We examine the role of gold as a hedge and safe haven from the perspective of Chinese investors. Using the Shanghai Futures Exchange (SHFE)‐Gold futures prices and the CSI 300 index from 2008 to 2017, we find that gold is not a hedge against the Chinese stock market on average. However, gold acts as a safe haven when market returns are below their 1%, 5%, and 10% quantiles and during the two crash periods. Our findings apply to most of the industry sectors as well. We also show that the role of gold can change drastically due to some market policy reforms.
Oral health status, behaviours, food and beverage consumption of aboriginal children in Australia
Authors: George Ajesh , Villarosa Amy R. , Ingram Suzanne , Fatema Kaniz , Elliott Koby , Grace Rebekah , Kemp Lynn , Scharkie Sheryl , Anderson Cheryl , Bucknall Natasha , Wright Darryl C. , Comino Elizabeth
Published: April 2020

Issue addressed

Dental decay is prevalent among Australian Aboriginal children, yet little is known about their oral health‐related behaviours. This study explored the oral health status, behaviours, food and beverage consumption of Aboriginal school children aged 7‐9 years in Sydney, Australia.

Methods

Parents who were part of an existing longitudinal birth cohort (“Gudaga”) were surveyed when their child was between 7 and 9 years. Children (n = 110) also received oral health screening by a trained nurse.

Results

A number of children (62%–91%) had at least one visible oral health problem across the 2 years. Around two thirds (62%–67%) of parents rated their child's oral health as excellent/very good and less than half the children (32%–45%) had received dental check‐ups. Most children (79%–90%) brushed their teeth and drank water (97%) but more than half (57%–70%) also drank sugar sweetened beverages daily.

Conclusions

Parents are instilling good oral health behaviours, however, the oral health screening suggests children are experiencing oral health issues of which parents may be unaware. Parents also seem to be unaware of beverage consumption practices that can increase the risk of childhood decay.

So what?

The findings highlight the need for greater oral health awareness among Aboriginal families on how to recognise early symptoms dental decay and risk factors like sugar sweetened beverages among school going children. This suggests that existing health promotion strategies may not be reaching many Aboriginal families in the urban areas and more culturally appropriate programs may be needed.
Integrated effects of fractional laser microablation and sonophoresis on skin immersion optical clearing in vivo
Authors: Genina Elina A. , Bashkatov Alexey N. , Terentyuk Georgy S. , Tuchin Valery V.
Published: April 2020

This study is aimed to find an approach for effective skin optical clearing in vivo using polyethylene glycol 300 (PEG‐300) as an optical clearing agent in combination with physical enhancers: fractional laser microablation (FLMA) and/or low‐frequency sonophoresis. In this study albino outbred rats were used. Light attenuation coefficient and optical clearing potential (OCP) of these approaches were evaluated in upper (from ~70 to ~200 μm) and middle (from ~200 to ~400 μm) dermis separately using optical coherence tomography. In 30 minutes, OCP of sonophoresis in combination with FLMA and PEG‐300 in the upper dermis was the maximal (2.3 ± 0.4) in comparison with other treatments in this time point. The most effective approach for optical clearing of middle dermis was PEG‐300 and sonophoresis; but the maximal value of OCP (1.6 ± 0.1) was achieved only in 90 minutes.
Inside Cover: Comparison between high definition FT‐IR, Raman and AFM‐IR for subcellular chemical imaging of cholesteryl esters in prostate cancer cells (J. Biophotonics 5/2020)
Authors: Roman Maciej , Wrobel Tomasz P. , Paluszkiewicz Czeslawa , Kwiatek Wojciech M.
Published: April 2020

The family of vibrational spectroscopic imaging techniques grows every few years and there is a need to compare and contrast new modalities with the better understood ones. Three vibrational spectroscopy techniques (High Definition FT‐IR, Raman and AFM‐IR) were applied for subcellular chemical imaging of cholesteryl esters in PC‐3 prostate cancer cells. The techniques were compared and contrasted in terms of image quality, spectral pattern, and chemical information.

Further details can be found in the article by Maciej Roman, Tomasz P. Wrobel, Czeslawa Paluszkiewicz, and Wojciech M. Kwiatek (e201960094).

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Long non‐coding RNA PVT1, a novel biomarker for chronic obstructive pulmonary disease progression surveillance and acute exacerbation prediction potentially through interaction with microRNA‐146a
Authors: Wang Yujun , Lyu Xiaoyu , Wu Xiaoling , Yu Li , Hu Ke
Published: April 2020

Objective

This study aimed to investigate the abilities of long non‐coding RNA PVT1 (lnc‐PVT1) and microRNA‐146a (miR‐146a) in predicting chronic obstructive pulmonary disease (COPD) susceptibility and acute exacerbation risk, moreover, to explore the association of lnc‐PVT1 with disease severity, inflammation, and miR‐146a in patients with COPD.

Methods

A total of 80 acute exacerbation of COPD (AECOPD) patients, 80 stable COPD patients, and 80 healthy controls (HCs) were consecutively recruited. Peripheral blood samples of all participants were collected to isolate peripheral blood mononuclear cells (PBMCs), and serum: PBMCs were used to detect lnc‐PVT1 and miR‐146a by RT‐qPCR; serum was used to detect inflammatory cytokines by ELISA. Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage of COPD was assessed.

Results

Lnc‐PVT1 expression was highest in AECOPD patients, followed by stable COPD patients and HCs. Receiver operating characteristic curves disclosed that lnc‐PVT1 distinguished AECOPD patients and stable COPD patients from HCs, also distinguished AECOPD patients from stable COPD patients. In AECOPD patients and stable COPD patients, lnc‐PVT1 expression positively correlated with GOLD stage and levels of TNF‐α, IL‐6, IL‐8, and IL‐17. Moreover, lnc‐PVT1 was negatively correlated with miR‐146a. For miR‐146a, its expression was lowest in AECOPD patients, followed by stable COPD patients and HCs, and it predicted reduced COPD susceptibility and decreased acute exacerbation risk; meanwhile, it negatively correlated with GOLD stage and inflammatory cytokine levels in AECOPD patients and stable COPD patients.

Conclusion

Lnc‐PVT1 assists the disease management and acute exacerbation risk monitoring of COPD via interaction with miR‐146a.
A meta‐analysis of toxicities related to hydroxycarbamide dosing strategies
Authors: Mathias Joacy G. , Nolan Vikki G. , Meadows‐Taylor Meghan , Robinson L. Ashley , Howell Kristen E. , Gurney James G. , Hankins Jane S. , Wang Winfred C. , Estepp Jeremie H. , Smeltzer Matthew P.
Published: April 2020

Due to fear of short‐term toxicities, there is nonconsensus of hydroxycarbamide dosing strategy (escalated vs fixed‐dosing methods), which contributes to its suboptimal use. We performed a meta‐analysis to summarize the incidence rates of toxicities associated with both dosing methods. Summarized incidence rates could not be statistically compared between dosing methods due to sparse data. Summarized neutropenia and thrombocytopenia incidence rates were slightly higher when using escalated dosing than with fixed. Summarized reticulocytopenia was comparable. Summarized hepatic and renal toxicities’ incidence rates were slightly higher when using fixed doses than with escalated. We recommend diligent and transparent reporting of toxicities.
Synthesis of hybrid perillyl‐4H‐pyrans. Cytotoxicity evaluation against hepatocellular carcinoma HepG2/C3A cell line
Authors: Paczkowski Ingrid M. , Guedes Esthéfani P. , Mass Eduardo B. , de Meneses Eliana W. , Marques Lilian A. , Mantovani Mário S. , Russowsky Dennis
Published: April 2020

A series of 15 new hybrid perillyl‐4H‐pyrans compounds was straightforwardly synthesized by a strategy combining the multicomponent reaction and the copper‐catalyzed alkyne‐azide cycloaddition (CuAAC). The 2‐amino‐4H‐pyrans‐3‐carbonitrile containing the alkyne moiety was prepared via multicomponent reaction between 1,3‐dicarbonyl, a propargyloxy aromatic aldehyde and malononitrile or ethyl α‐cyanoacetate. The alkyne derivative was sequentially reacted with the perillyl azide component through the copper‐catalyzed [3+2] Huisgen cycloaddition reaction. The antiproliferative activity of hybrid compounds were evaluated against the human hepatoma HepG2/C3A cell line.
Full‐length genomic sequencing and characterization of Borna disease virus 1 isolates: Lessons in epidemiology
Authors: Guo Yujie , He Peng , Sun Lin , Zhang Xiong , Xu Xiaoyan , Tang Tian , Zhou Wei , Li Qi , Zou Dezhi , Bode Liv , Xie Peng
Published: April 2020

Borna disease virus 1 (BoDV‐1) is a nonsegmented, negative‐strand RNA virus that infects mammals including humans. BoDV‐1 strains occur globally, dominate the species Mammalian 1 bornavirus, and display highly conserved genomes and persistent infection (brain, blood). Subclinical infections prevail but the rare fatal outcomes even in people need awareness and risk assessment. Although BoDV‐1 strains were successfully isolated, only limited full genomic sequences are available. In this study, the entire genomes of two natural BoDV‐1 isolates (Hu‐H2, Equ‐Cres) and one vaccine strain (DessVac) were sequenced. They were compared with 20 genomes and 20 single‐gene sequences (N and P) of worldwide human strains from psychiatric and neurologic patients and animal strains from horses with Borna disease available at GenBank. Phylogenetic analyses confirmed a low divergence not exceeding 5.55%, 5.34%, and 4.94% at the genome, P‐gene, and N‐gene level, respectively, characteristic of BoDV‐1. Human viruses tended to cluster at the country level but appeared to be independent of hosts’ diseases and/or time of isolation. Notably, our data also indicated that human viruses provided individual genetic signatures but exhibited no distinct genotypes that separated them from animal strains. Sequence similarities thus occurred between different host species and distant geographic regions, supporting global BoDV‐1 prevalence. Overall low genetic divergence among BoDV‐1 viruses shown here also argued against zoonotic concepts, requiring further clarification beyond sequence similarities. Finally, unlike shared sequence conservation, phenotyping of natural and laboratory variants revealed that they manipulated host cells differently, underpinning the authenticity of the human BoDV‐1 strains.
Bioprospecting and characterization of pigmented halophilic archaeal strains from Algerian hypersaline environments with analysis of carotenoids produced by Halorubrum sp. BS2
Authors: Sahli Kaouther , Gomri Mohamed A. , Esclapez Julia , Gómez‐Villegas Patricia , Ghennai Oulaya , Bonete María‐José , León Rosa , Kharroub Karima
Published: April 2020

A set of 110 extremely halophilic archaeal strains were isolated from seven distinct saline habitats located in different regions of Algeria. The physicochemical characterization of the samples showed that these habitats were thalassohaline. The carotenoid production from isolated strains varied from 0.1 to 3.68 µg/ml. Based on their physiological characteristics and pigment production, 43 strains were selected and identified by means of phenotypic tests and 16S ribosomal RNA gene sequencing. Phylogenetic analysis indicated that the isolates corresponded to the class Halobacteria and were closely related to genera Halorubrum, Haloarcula, Haloferax, Natrinema, Halogeometricum, Haloterrigena, and Halopiger. Carotenoids of the highest producer, strain Halorubrum sp. BS2 were identified using high‐performance liquid chromatography–diode array detector and liquid chromatography–mass spectrometry. Bacterioruberin and bisanhydrobacterioruberin were the predominant carotenoids. The scavenging activity of these carotenoids reached 99% at a concentration of 18 μg/ml, which was much higher than that of ascorbic acid used as a reference compound. These carotenoids also exhibited significant antibacterial activities against four human‐pathogenic strains and four fish‐pathogenic strains. Variations in salinity, agitation rate, temperature, and light intensity were found to influence growth and carotenoid production of Halorubrum sp. BS2. Our results suggest that halophilic archaea represent a potential source for carotenoids, which are characterized by high antioxidant and antibacterial activities.
An ERA‐Interim HAILCAST hail climatology for southern Africa
Authors: Dyson Liesl L. , Pienaar Nita , Smit Ansie , Kijko Andrzej
Published: April 2020

Understanding the character of hail is an important part of mitigating its impact on life and property. Climatologies of hail over South Africa are rare and based on observed data with a coarse spatial and temporal resolution. In this article, a hail climatology is created for southern Africa from reanalysis data. Pseudo‐soundings are produced from ERA‐Interim data and the HAILCAST model, which predicts the diameter of hail, is run using these soundings from 1979 to 2017 at six‐hourly intervals. The hail day frequency of the ERA‐Interim HAILCAST (EIH) climatology compares well to historical climatologies, although the horizontal resolution of ERA‐Interim makes it difficult to pinpoint the exact location of hail in areas of steep topography. Furthermore, the EIH climatology tends to over‐predict hail with diameters greater than 3 cm. Detail that was previously unavailable, such as the seasonal and temporal distribution of hail over the entire South Africa, is now available from the EIH climatology. The frequency of hail over the winter rainfall area and over countries bordering South Africa is estimated for the first time. It is recommended that the procedure is repeated with numerical weather prediction models with a higher resolution to determine whether the increased resolution will more accurately identify areas of hail.