bluuebunny/crossref_metadata_2025 huggingface dataset:
Coercive Fields Above 6 T in Two Cobalt(II)–Radical Chain Compounds
Authors: Liu Xiaoqing , Feng Xiaowen , Meihaus Katie R. , Meng Xixi , Zhang Yuan , Li Liang , Liu Jun‐Liang , Pedersen Kasper S. , Keller Lukas , Shi Wei , Zhang Yi‐Quan , Cheng Peng , Long Jeffrey R.
Published: April 2020

Lanthanide permanent magnets are widely used in applications ranging from nanotechnology to industrial engineering. However, limited access to the rare earths and rising costs associated with their extraction are spurring interest in the development of lanthanide‐free hard magnets. Zero‐ and one‐dimensional magnetic materials are intriguing alternatives due to their low densities, structural and chemical versatility, and the typically mild, bottom‐up nature of their synthesis. Here, we present two one‐dimensional cobalt(II) systems Co(hfac)2(R‐NapNIT) (R‐NapNIT=2‐(2′‐(R‐)naphthyl)‐4,4,5,5‐tetramethylimidazoline‐1‐oxyl‐3‐oxide, R=MeO or EtO) supported by air‐stable nitronyl nitroxide radicals. These compounds are single‐chain magnets and exhibit wide, square magnetic hysteresis below 14 K, with giant coercive fields up to 65 or 102 kOe measured using static or pulsed high magnetic fields, respectively. Magnetic, spectroscopic, and computational studies suggest that the record coercivities derive not from three‐dimensional ordering but from the interaction of adjacent chains that compose alternating magnetic sublattices generated by crystallographic symmetry.
Transition Metal Nitrides as Promising Catalyst Supports for Tuning CO/H2Syngas Production from Electrochemical CO2Reduction
Authors: Liu Yumeng , Tian Dong , Biswas Akash N. , Xie Zhenhua , Hwang Sooyeon , Lee Ji Hoon , Meng Hong , Chen Jingguang G.
Published: April 2020

The electrochemical carbon dioxide reduction reaction (CO2RR) to produce synthesis gas (syngas) with tunable CO/H2ratios has been studied by supporting Pd catalysts on transition metal nitride (TMN) substrates. Combining experimental measurements and density functional theory (DFT) calculations, Pd‐modified niobium nitride (Pd/NbN) is found to generate much higher CO and H2partial current densities and greater CO Faradaic efficiency than Pd‐modified vanadium nitride (Pd/VN) and commercial Pd/C catalysts. In‐situ X‐ray diffraction identifies the formation of PdH in Pd/NbN and Pd/C under CO2RR conditions, whereas the Pd in Pd/VN is not fully transformed into the active PdH phase. DFT calculations show that the stabilized *HOCO and weakened *CO intermediates on PdH/NbN are critical to achieving higher CO2RR activity. This work suggests that NbN is a promising substrate to modify Pd, resulting in an enhanced electrochemical conversion of CO2to syngas with a potential reduction in precious metal loading.
Cycloisomerization of Olefins in Water
Authors: Matos Jeishla L. M. , Green Samantha A. , Chun Yuge , Dang Vuong Q. , Dushin Russell G. , Richardson Paul , Chen Jason S. , Piotrowski David W. , Paegel Brian M. , Shenvi Ryan A.
Published: April 2020

Preparative reactions that occur efficiently under dilute, buffered, aqueous conditions in the presence of biomolecules find application in ligation, peptide synthesis, and polynucleotide synthesis and sequencing. However, the identification of functional groups or reagents that are mutually reactive with one another, but unreactive with biopolymers and water, is challenging. Shown here are cobalt catalysts that react with alkenes under dilute, aqueous, buffered conditions and promote efficient cycloisomerization and formal Friedel–Crafts reactions. The constraining conditions of bioorthogonal chemistry are beneficial for reaction efficiency as superior conversion at low catalyst concentration is obtained and competent rates in dilute conditions are maintained. Efficiency at high dilution in the presence of buffer and nucleobases suggests that these reaction conditions may find broad application.
Experimental study on anti‐crystallization law of tunnel transverse flocking drainpipe at different velocities
Authors: Liu Shiyang , Gao Feng , Zhang Xuefu , Han Fenglei , Zhou Yuanfu , Xiang Kun , Xiao Dongjie
Published: April 2020

With the increasing of the tunnel operation life, various diseases of the tunnel are gradually highlighted, especially the lining cracking and leakage caused by the crystal blocking pipe of the drainage system, which brings serious hidden trouble to the safe operation of the tunnel. In order to solve the problem of crystal plugging of horizontal drainage pipe in tunnel, the transverse drainage pipe of the tunnel was taken as the research object, combined with the field survey data, and the indoor test was used to analyze the anti‐crystallization law of flocking drainage pipe at different velocities. The results showed that the flocking drainage pipes had an anti‐crystallization effect, and the anti‐crystallization efficiency could be increased by more than 50% compared with the ordinary drainage pipes, and the flow rate at 6.82 cm/s could reach more than 60%. At the flow rate of 5.46 cm/s, the crystallization on flocking drainage pipes at the later stage of the test remained basically unchanged and was less than that on ordinary drainage pipes. The change in the weight of crystals on the flocking drainage pipes was approximately sinusoidal, and the change period was different at different flow rates; among which, the change period of crystallization on the flocking drainpipe was shorter when the villi length was shorter at low flow rates.
From the lab to the river: Determination of ecological hosts of Anodonta anatina
Authors: Dias Ana Rita , Teixeira Amílcar , Lopes‐Lima Manuel , Varandas Simone , Sousa Ronaldo
Published: April 2020

Coextinction is the simplest form of secondary extinction and freshwater mussels (Bivalvia, Unionida) may be particularly prone to this phenomenon as their life cycle includes an obligatory parasitic larval stage on fish hosts.

The main aims of this study were to determine the possible ecological fish hosts of Anodonta anatina (Linnaeus, 1758) in several rivers of the Douro basin in northern Portugal and to assess possible spatial and temporal differences in glochidial (larval) loads. In order to achieve this, electrofishing was conducted from December to April, the fish fauna was characterized, and levels of infestation with A. anatina glochidia were determined.

Native cyprinid species, mainly Luciobarbus bocagei (Iberian barbel) and Squalius carolitertii (northern Iberian chub), together with the non‐native Lepomis gibbosus (pumpkinseed sunfish) and Alburnus alburnus (common bleak), were found to have the highest glochidial loads. Clear differences in infestation between rivers and throughout time were detected, with an infestation period from January to March, and with the Tâmega River having the highest prevalence.

Anodonta anatina is able to infest a variety of fish species, and this together with earlier studies showed that the metamorphosis into juveniles occurs mainly in native cyprinid species, although non‐native species like common bleak can also be considered suitable hosts. However, the larvae infesting other non‐native species, such as the pumpkinseed sunfish, do not metamorphose and can be considered ‘dead ends’.

Overall, the results reported here are important for the conservation of A. anatina (and other unionoid species) because several Iberian rivers (and worldwide) have been subjected to the extirpation of native fish species and the introduction of non‐native fish species. Therefore, careful assessments of fish communities should be conducted to assess possible negative interactions with freshwater mussels.
New halogenated chalcones with cytotoxic and carbonic anhydrase inhibitory properties: 6‐(3‐Halogenated phenyl‐2‐propen‐1‐oyl)‐2(3H)‐benzoxazolones
Authors: Bilginer Sinan , Gul Halise I. , Erdal Feyza S. , Sakagami Hiroshi , Gulcin Ilhami
Published: April 2020

In this study, novel halogenated chalcones, 6‐(3‐halogenated phenyl‐2‐propen‐1‐one)‐2(3H)‐benzoxazolones (2a–n), were synthesized for the first time (except 2a), and their chemical structures were characterized by 1H nuclear magnetic resonance (NMR), 13C NMR, and high‐resolution mass spectrometry spectra. Cytotoxic activities and carbonic anhydrase (CA) inhibitory effects of the compounds were studied to identify new possible drug candidate molecules. Cytotoxicity results pointed out that compound 2m, 6‐[3‐(3‐bromophenyl)‐2‐propenoyl]‐2(3H)‐benzoxazolone, had the highest cytotoxicity (CC50) and potency selectivity expression (PSE) values. Thus, compound 2m can be considered as a lead compound of the series in terms of cytotoxicity. When the CA inhibition results of the compounds were evaluated, it was found that the Ki values of the compounds ranged from 30.5 ± 11.3 to 65.5 ± 25.6 µM toward hCA I, and they ranged from 7.3 ± 1.8 to 58.8 ± 12.3 µM toward hCA II. However, the Ki values of the reference drug, acetazolamide (AZA), were 30.2 ± 7.8 and 4.4 ± 0.6 μM toward hCA I and hCA II, respectively. According to the results obtained, compounds 2a–n had lower Ki values than AZA, whereas compounds 2a, 2b, 2e–g, 2l, and 2n had similar Ki values, compared with AZA. So, the compounds 2a, 2b, 2e–g, 2l, and 2n can be considered as lead molecules of this series for further considerations.
An Initial Examination of Post‐Traumatic Stress Disorder in Mothers of Children with Autism Spectrum Disorder: Challenging Child Behaviors as Criterion A Traumatic Stressors
Authors: Schnabel Alexandra , Hallford David J. , Stewart Michelle , McGillivray Jane A. , Forbes David , Austin David W.
Published: April 2020

Parenting a child with autism spectrum disorder (ASD) is associated with high levels of stress. Several studies have conceptualized this as a traumatic stress response to challenging child behaviors such as self‐harm, suicidal ideation, and physical aggression toward caregivers. In the present study, we explored the relevance of a trauma‐based diagnostic framework to a sample of 30 mothers (M age = 42.97, SD = 5.82) of children with ASD (M age = 12.43, SD = 3.15). Participants were interviewed using the Clinician‐Administered PTSD Scale for DSM‐5 (CAPS‐5) for post‐traumatic stress disorder (PTSD) and an abbreviated Mini International Neuropsychiatric Interview to assess for comorbidity. Three participants were excluded as they met criteria for PTSD from a traumatic event unrelated to their parenting experience. Of the remaining 27 participants, 6 (22.2%) met criteria for PTSD in the context of traumatic parenting experiences. Descriptions of traumatic events experienced are summarized. Results suggest that, for some parents, challenging child behaviors such as physical violence toward the caregiver from the child, self‐injurious behaviors, and suicidal behaviors function as traumatic stressors as per Criterion A of PTSD (American Psychiatric Association [2013]. Diagnostic and statistical manual of mental disorders [DSM‐5]. Arlington, VA). This has implications for health professionals engaged with parents of children with ASD, who should consider the possibility of PTSD when challenging behaviors of a potentially traumatic nature are present. Autism Res 2020. © 2020 International Society for Autism Research, Wiley Periodicals, Inc.

Lay Summary

This study found that some challenging behaviors exhibited by children with autism spectrum disorder can be traumatic for parents and lead to the development of post‐traumatic stress disorder. Some of these behaviors included self‐harming behaviors like head banging, expressing suicidal urges, and becoming physically aggressive toward parents during meltdowns. Autism Res 2020, 13: 1527–1536. © 2020 International Society for Autism Research, Wiley Periodicals, Inc.
The prevalence of the Rouviere's sulcus: A meta‐analysis with implications for laparoscopic cholecystectomy
Authors: Cheruiyot Isaac , Nyaanga Fiona , Kipkorir Vincent , Munguti Jeremiah , Ndung'u Bernard , Henry Brandon , Cirocchi Roberto , Tomaszewski Krzysztof
Published: April 2020

Rouvière's sulcus (RS) is increasingly being recognized as an important extra‐biliary landmark during laparoscopic cholecystectomy (LC). The aim of this study was to conduct a systematic analysis of the prevalence and morphological types of RS. A systematic search was conducted through the major databases PubMed, ScienceDirect, Google Scholar, China National Knowledge Infrastructure (CNKI), SciELO, and the Cochrane Library to identify studies eligible for inclusion. The data were extracted and pooled into a random‐effects meta‐analysis using STATA software. The primary and secondary outcomes of the study were the pooled prevalence of RS and its morphological types, respectively. A total of 23 studies (n= 4,495 patients) were included. The overall pooled prevalence of RS was 83% (95% confidence interval [CI] [78, 87]). There were no significant differences in prevalence between cadaveric studies (82%, 95% CI [76, 87]) and laparoscopic studies (83%, 95% CI [77, 88]). The open RS constituted 66% (95% CI [61, 71]) of all cases, while the closed type was present in 34% (95% CI [29, 39]). RS is a relatively constant anatomical structure that can be reliably identified in most patients undergoing cholecystectomy. It can therefore be used as a fixed extra‐biliary landmark for the appropriate site at which to start dissecting during LC to help prevent iatrogenic bile duct injury.
Chartarlactams Q−T, Dimeric Phenylspirodrimanes with Antibacterial and Antiviral Activities
Authors: Liu Dong , Li Yong , Guo Xingchen , Ji Wei , Lin Wenhan
Published: April 2020

Four new phenylspirodrimane‐type dimers, namely chartarlactams Q−T, along with stachyin B were isolated from the fermentation broth of a sponge‐derived fungus Stachybotrys chartarum WGC‐25 C‐6. Chartarlactams Q−T were structurally featured by the dimerization of two units of phenylspirodrimane linked by a C−N bond. Their structures were determined on the basis of extensive spectroscopic analysis, while quantum ECD calculation and modified Mosher's method were used for the assignment of absolute configurations. Chartarlactams Q−S and stachyin B showed moderate inhibition against bacterial pathogen Staphylococcus aureus with MIC values ranging from 4 μg/mL to 16 μg/mL, and chartarlactam T exhibited significant inhibition toward ZIKV virus.
Milker’s nodule: An under‐reported and under‐diagnosed occupational infection
Authors: Poudel Guru Prasad , Agrawal Sudha , Dhakal Sushil
Published: April 2020

Single or multiple minimal painful nodulo‐ulcerative lesions over hand in dairy farm worker suggest likelihood of Milker's nodule.Use of personal protective equipment and antiseptics suffice treatment without unnecessary investigation and medicine.
Esophageal perforation in case of thyroid lymphoma
Authors: Anagnostis Panagiotis , Vaitsi Konstantina , Tzelepi Keraso , Kalaitzis Efstratios
Published: April 2020

Esophageal perforation is a rare and serious complication of thyroid lymphoma and should be taken under consideration in cases with rapid deterioration in their course. Clinical suspicion and prompt diagnosis are key factors for reducing mortality risks in these cases.
Orthodontic treatment of an adult Class II division 1 malocclusion with nonextraction assisted by lip myofunctional training: A case report
Authors: Hou Jianhua , Meng Xiuping
Published: April 2020

Consideration of facial soft tissue is critical in orthodontic diagnosis and treatment planning to achieve improvement in facial esthetics as well as dental occlusion. As is illustrated by success in orthodontic treatment of an adult Class II division 1 malocclusion with nonextraction and assisted by lip myofunctional training.
Elucidating the Molecular Basis of Avibactam‐Mediated Inhibition of Class A β‐Lactamases
Authors: Das Chandan Kumar , Nair Nisanth N.
Published: April 2020

Disseminating antibiotic resistance rendered by bacteria against the widely used β‐lactam antibiotics is a serious concern for public health care. The development of inhibitors for drug‐resistant β‐lactamase enzymes is vital to combat this rapidly escalating problem. Recently, the U.S. Food and Drug Administration approved a non‐β‐lactam inhibitor called avibactam for the treatment of complicated intra‐abdominal and urinary tract infections caused by drug‐resistant Gram‐negative bacteria. This work sheds light on the molecular origin of the inhibitory effect of avibactam against the drug‐resistant CTX‐M variant of class A β‐lactamases. In particular, we probed the structural evolution, dynamics features, and energetics along the acylation and deacylation reaction pathways through enhanced sampling molecular dynamics methods and free‐energy calculations. We scrutinized the roles of active site residues, the nature of the carbamoyl linkage formed in the inhibitor–enzyme covalent intermediate, and other structural features of the inhibitor molecule. By unraveling the reasons behind the inhibition of all the deacylation routes, we can explain various experimental structural and kinetics data, and propose a way to design new inhibitors based on the β‐lactam framework.
A Phosphine Functionalized β‐Diketimine Ligand for the Synthesis of Manifold Metal Complexes
Authors: Zovko Christina , Bestgen Sebastian , Schoo Christoph , Görner Anne , Goicoechea Jose M. , Roesky Peter W.
Published: April 2020

A bis(diphenyl)‐phosphine functionalized β‐diketimine (PNac‐H) was synthesized as a flexible ligand for transition metal complexes. The newly designed ligand features symmetrically placed phosphine moieties around a β‐diketimine unit, forming a PNNP‐type pocket. Due to the hard and soft donor atoms (N vs. P) the ligand can stabilize various coordination polyhedra. A complete series ranging from coordination numbers 2 to 6 was realized. Linear, trigonal planar, square planar, tetrahedral, square pyramidal, and octahedral coordination arrangements containing the PNac‐ligand around the metal center were observed by using suitable metal sources. Hereby, PNac‐H or its anion PNac− acts as mono‐, bi‐ and tetradendate ligand. Such a broad flexibility is unusual for a rigid tetradentate system. The structural motifs were realized by treatment of PNac‐H with a series of late transition metal precursors, for example, silver, gold, nickel, copper, platinum, and rhodium. The new complexes have been fully characterized by single crystal X‐ray diffraction, NMR, IR, UV/Vis spectroscopy, mass spectrometry as well as elemental analysis. Additionally, selected complexes were investigated regarding their photophysical properties. Thus, PNac‐H proved to be an ideal ligand platform for the selective coordination and stabilization of various metal ions in diverse polyhedra and oxidation states.
Systematic DFT Studies on Binary Pseudo‐tetrahedral Zintl Anions: Relative Stabilities and Reactivities towards Protons, Trimethylsilyl Groups, and Iron Complex Fragments
Authors: Guggolz Lukas , Dehnen Stefanie
Published: April 2020

Binary pseudo‐tetrahedral Zintl anions composed of (semi)metal atoms of the p‐block elements have proven to be excellent starting materials for the synthesis of a variety of heterometallic and intermetalloid transition metal–main group metal cluster anions. However, only ten of the theoretically possible 48 anions have been experimentally accessed to date as isolable salts. This brings up the question whether the other species are generally not achievable, or whether synthetic chemists just have not succeeded in their preparation so far. To contribute to a possible answer to this question, global minimum structures were calculated for all anions of the type (TrTt3)5−, (TrPn3)2−, and (Tt2Pn2)2−, comprising elements of periods 3 to 6 (Tr: triel, Al⋅⋅⋅Tl; Tt: tetrel, Si⋅⋅⋅Pb; Pn: pnictogen, P⋅⋅⋅Bi). By analyzing the computational results, a concept was developed to predict which of the yet missing anions should be synthesizable and why. Additionally, the results of an electrophilic attack by protons or trimethylsilyl groups or a nucleophilic attack by transition metal complex fragments are described. The latter yields butterfly‐like structures that can be viewed as a new form of adaptable tridentate chelating ligands.
Optimal balanced block designs for correlated observations
Authors: Khodsiani Razieh , Pooladsaz Saeid
Published: April 2020

The construction of universally optimal designs, if such exist, is difficult to obtain, especially when there are some nuisance effects or correlated errors. The hub correlation is a special correlation structure with applications to experiments in genetics, networks and other areas in industry and agriculture. There may be restrictions on the correlation values of the hub structure depending on the experiment. Optimality of block designs under hub correlation has been studied for the case of a constant correlation value. In this article, we consider the hub structure when one of the correlation values is different from the others, and the universally optimal block designs, binary or non‐binary, are theoretically obtained. Also, we introduce an algorithm to construct the optimal designs. The Canadian Journal of Statistics 48: 596–604; 2020 © 2020 Statistical Society of Canada
Forensics in the teaching lab and in the teacher training
Authors: Nitsche Edith , Lühken Arnim , Handel Robyn
Published: April 2020

Das SuFiS‐Projekt (Studieren und Forschen im Schülerlabor) ermöglicht im Rahmen eines Lehr‐Lern‐Arrangements eine Verzahnung von Theorie und Praxis in der Ausbildung von Lehramtsstudierenden. Dieses Projekt bietet den Studierenden neben der Betreuung durch fachdidaktisch ausgebildete MitarbeiterInnen auf universitärer Ebene den direkten Austausch mit Lehrkräften und eine enge Zusammenarbeit mit deren Schülergruppen. Die Studierenden haben die Gelegenheit, ihre Materialen mit der Unterstützung der BetreuerInnen zu entwickeln, mit Lehrkräften zu diskutieren, zu reflektieren und anschließend mit deren Schülergruppen zu testen. Sie erhalten dadurch einen breit gefächerten Einblick in ihr späteres Berufsleben [1].

Die Arbeit im SuFiS−Projekt ermöglicht den Studierenden erste Erfahrungen im Planen, Durchführen und Reflektieren von Lernsituationen mit Schulklassen. Übung und Reflexion des Experimentierens mit Schülergruppen und die Auseinandersetzung mit fachdidaktischer Theoriebildung liegen im Zentrum dieses Lehr‐Lern‐Angebots. Durch ein ausgeglichenes Theorie‐Praxis‐Verhältnis werden die angehenden Lehrkräfte besser auf die Schulpraxis vorbereitet und die möglichen Schwierigkeiten beim Eintritt in die zweite Ausbildungsphase [10] können abgemildert werden.
Differences in ambulatory care fragmentation between cancer survivors and noncancer controls
Authors: Pinheiro Laura C. , Reshetnyak Evgeniya , Safford Monika M. , Nanus David , Kern Lisa M.
Published: April 2020

Background

Patients with chronic conditions are treated by many providers, which can increase the risk of communication gaps across providers and potential harm to patients. However, to the authors' knowledge, the extent of fragmented care among this population is unknown. In the current study, the authors sought to determine whether cancer survivors have more fragmented care than noncancer controls and to quantify the extent of fragmentation.

Methods

Data from the REasons for Geographic And Racial Differences in Stroke (REGARDS) study linked to Medicare claims were used. The authors included beneficiaries with continuous Part A and B coverage for 12 months at the time of their baseline REGARDS survey. The primary outcome of the current study was claims‐based fragmentation over 12 months, which was calculated using the reversed Bice‐Boxerman Index so a higher score reflected greater fragmentation. Unadjusted differences in fragmentation were compared between cancer survivors and controls. Beta regression models were used to estimate associations between cancer status and fragmentation, adjusting for potential confounders.

Results

The authors included 4922 participants aged ≥65 years at baseline. Of these patients, approximately 21% were cancer survivors. Survivors had a median of 11 visits (interquartile range, 7‐15 visits) with 5 providers compared with controls, who had a median of 9 visits (interquartile range, 6‐14 visits) with 4 providers (P < .0001). Cancer survivors had significantly more fragmented care compared with controls (median reversed Bice‐Boxerman Index, 0.80 vs 0.76; P < .0001). After adjusting for confounders, cancer survivors had an increased odds of having fragmented care (odds ratio, 1.08; 95% CI, 1.02‐1.14).

Conclusions

Care fragmentation is more prevalent among cancer survivors compared with those without a history of cancer. Future studies should examine whether fragmentation puts survivors at risk of worse outcomes.
Unveiling the Effect of Surface and Bulk Structure on Electrochemical Properties of Disproportionated SiOx Anodes
Authors: Long Zuxin , Fu Rusheng , Ji Jingjing , Feng Zuyong , Liu Zhaoping
Published: April 2020

As a promising lithium‐ion battery anode materials, silicon suboxides (SiOx) exhibit elusive microstructure with atomic‐scale disproportionation which reveals a strong relation to performance. Generally, the structure of SiOx could be tuned via high‐temperature treatment. In this work, disproportionated SiOx are prepared to systematically discuss the internal relationship among microstructure, physicochemical properties and electrochemical performance. After annealing, amorphous SiO2 and nanocrystalline Si appear, and the SiO2 accumulating on the surface results in large resistance and low Li‐ion diffusivity, which leads to large overpotential and poor performance. If mechanical milling is employed followed by annealing, the SiO2 layer can be crushed, SiOx and Si with electrochemical activity are uncovered. Further research on the SiOx with diverse degrees of disproportionation indicates that proper amount of Si and SiO2 determines the optimal electrochemical performance. This result gives an in‐depth understanding and probable guidance to the modification investigation of SiOx anode for Li‐ion batteries.
Estimation of Microbial Viability Using Flow Cytometry
Authors: Davey Hazel , Guyot Stéphane
Published: April 2020

For microorganisms in particular, viability is a term that is difficult to define and a state consequently difficult to measure. The traditional (and gold standard) usage equates viability and culturability (i.e., the ability to multiply) but the process of determining culturability is often too slow. Flow cytometry provides the opportunity to make rapid and quantitative measurements of dye uptake in large numbers of cells and we can therefore exploit the flow cytometric approach to evaluate so‐called viability stains and to develop protocols for more routine assessments of microbial viability. This article provides a commentary and several protocols have been included to ensure that users have a firm basis for attempting these reasonably difficult assays on traditional flow cytometer instruments. What is clear is that each assay must be carefully validated with the particular microorganism of interest before being applied in any research, clinical, or service form. © 2020 The Authors.
A flexible n/2 adversary node resistant and halting recoverable blockchain sharding protocol
Authors: Xu Yibin , Huang Yangyu , Shao Jianhua , Theodorakopoulos George
Published: April 2020

Blockchain sharding is a promising approach to solving the dilemma between decentralization and high performance (transaction throughput) for blockchain. The main challenge of blockchain sharding systems is how to reach a decision on a statement among a subgroup (shard) of people while ensuring the whole population recognizes this statement. Namely, the challenge is to prevent an adversary who does not have the majority of nodes globally but have the majority of nodes inside a shard. Most blockchain sharding approaches can only reach a correct consensus inside a shard with at most n/3 evil nodes in a n node system. There is a blockchain sharding approach which can prevent an incorrect decision to be reached when the adversary does not have n/2 nodes globally. However, the system can be stopped from reaching consensus (become deadlocked) if the adversary controls a smaller number of nodes. In this article, we present an improved Blockchain sharding approach that can withstand n/2 adversarial nodes and recover from deadlocks. The recovery is made by dynamically adjusting the number of shards and the shard size. A performance analysis suggests our approach has a high performance (transaction throughput) while requiring little bandwidth for synchronization.
A naive learning algorithm for class‐bridge‐decomposable multidimensional Bayesian network classifiers
Authors: Lv Yali , Hu Weixin , Liang Jiye , Qian Yuhua , Miao Junzhong
Published: April 2020

Multidimensional Bayesian network classifier (MBC) has become a popular classification model because of their intuitive graphical representation ability among class variables. But learning MBC and performing multidimensional classification based on the MBC can be very computationally demanding. For the tractability of performing multidimensional classification, a class‐bridge‐decomposable (CB‐decomposable) MBC model is proposed and it alleviates the computation complexity. But there are few works to efficiently and systematically learn the CB‐decomposable MBC model. Thus, we focus on addressing a naive learning algorithm of CB‐decomposable MBCs. Briefly, we learn the CB‐decomposable MBC model by dividing it into three components: class subgraph, bridge subgraph, and feature subgraph. First, we analyze why the class subgraph can be learned based on general Bayesian network learning methods. Second, we give how to learn bridge subgraph based on information gain ratio. Third, to make the CB‐decomposable MBC model effective and simple, we also study the learning and updating strategies of feature subgraph. Further, we propose the naive learning algorithm of the CB‐decomposable MBC. Finally, by comparing with other methods on several benchmark datasets, experimental results illustrate that our naive learning algorithm not only has higher accuracies, lower learning, and classification times but also has simple and intuitive representation ability.
Research on the application of mobile payment security system based on the Internet of Things
Authors: Xu Bing , Huang Darong , Mi Bo
Published: April 2020

Based on the relationship between the Internet of Things (IoT) and mobile payment, this article analyzed the security characteristics of IoT mobile payment. The security system of IoT mobile payment was constructed according to the security demands of mobile payment. Finally, the mobile payment security system was utilized to grade the current level of mobile payment security in China, which verified the urgent problems in China's mobile payment security. The security system of mobile payment based on IoT is a set of macro theoretical systems, whose establishment can lay a theoretical foundation for its branch theoretical research in the future. Meanwhile, it is applicable to the quantitative evaluation of mobile payment security level in China, and has certain guiding significance in theory and practice.
Insights into the Thermal and Photochemical Reaction Mechanisms of Azidoacetonitrile. Spectroscopic and MS‐CASPT2 Calculations
Authors: Algarra Manuel , Soto Juan
Published: April 2020

This work studies the photochemical and thermal decompositions of azidoacetonitrile (N3CH2CN) from both the experimental and theoretical points of view. The data of the photochemical experiments are taken from the literature, while the thermal decomposition have been carried out by us. In addition, we have performed ab initio calculations of the multiconfigurational type [complete active space self‐consistent field (CASSCF) and the multistate multireference perturbation theory (MS‐CASPT2)]. It is found that the first step of both type of decompositions is N2 elimination and formation of closed shell singlet nitrene. Afterwards, the nitrene tends to rapidly rearrange into formimidoyl cyanide (HNCHCN). As both reactions progress, the imine isomerizes into formimidoyl isocyanide (HNCHNC). The photoisomerization of the imine takes places thorough a conical intersection, while the same reaction on the ground electronic state occurs via a conventional transition state. The last step of the global reaction is decomposition of the imines into HCN and CNH. In photochemical conditions, the conjunction of the imines and its dissociation products (HCN and CNH) yields adenine
Anion⋅⋅⋅Anion Attraction in Complexes of MCl3− (M=Zn, Cd, Hg) with CN−
Authors: Wysokiński Rafał , Zierkiewicz Wiktor , Michalczyk Mariusz , Scheiner Steve
Published: April 2020

High‐level ab initio calculations show that the MCl3− anions comprising Group 2B M atoms Zn, Cd, and Hg form a stable complex with the CN− anion, despite the like charge of the two ions. The complexation occurs despite a negative π‐hole region above the M atom of MCl3−. The dimerization distorts the planar geometry of MCl3− into a pyramidal shape which reduces the negative potential above the M atom, facilitating a close approach of the two anions, with R(M⋅⋅⋅C)∼2 Å, and an overall attractive electrostatic attraction within the dimer. In the gas phase, this dimer is less stable than the pair of separated ions by some 30 kcal/mol. However, the dissociation must surmount an energy barrier of roughly 25 kcal/mol which occurs at an intermolecular distance of 4 Å. In aqueous solution, the dimerization process is exothermic and barrier‐free, with a binding energy in the 11–18 kcal/mol range.
Relative stability of alexithymia and openness to emotions in one psychiatric day hospital setting
Authors: Triffaux Jean‐Marc , Nasello Julian , Luminet Olivier , Servais Catherine , Close Mireille , Quertemont Etienne , Blavier Adélaïde
Published: April 2020

Alexithymia (literally, difficulty finding words for emotions) and openness to emotions (OE: referring to the cognitive representation, communication, regulation, perception of internal and external bodily sensations, and social restriction of emotions) are strongly linked to psychopathology. The absolute and relative stability hypotheses were tested in order to determine whether significant changes occurred on these constructs after therapy, a condition where changes were expected for both constructs. Negative attitudes toward treatment (NTI) and perceived social support (PSS) were expected to significantly predict alexithymia and OE. Patients (N = 179) who participated in this longitudinal study filled in the Toronto Alexithymia Scale, the Dimensions of Openness to Emotions Scale, the NTI subscale, the Multidimensional Scale of Perceived Social Support, and the Social Desirability Scale. After treatment, we observed significant decrease of all alexithymia scores and significant increases of three OE scores, that is, cognitive representation, communication, and regulation of emotions. Regression analyses revealed that gender, age, NTI, and PSS were significant predictors of alexithymia and OE. NTI strongly predicted lower OE levels and higher alexithymia levels, whereas PSS had opposite predicting effects on these constructs. In conclusion, the significant changes, and the moderate to high correlational levels observed between before and after alexithymia and OE scores, strengthen the relative stability hypothesis for both constructs. In addition, PSS represents a protective factor and NTI a vulnerability indicator for therapists. Our aim is to optimize treatment by providing therapists treating emotion difficulties a more concrete array of variables that potentially either promote or subvert recovery.
Optimizing Hydroxychloroquine Dosing for Patients With COVID‐19: An Integrative Modeling Approach for Effective Drug Repurposing
Authors: Garcia‐Cremades Maria , Solans Belen P. , Hughes Emma , Ernest Jacqueline P. , Wallender Erika , Aweeka Francesca , Luetkemeyer Anne F. , Savic Radojka M.
Published: April 2020

Hydroxychloroquine (HCQ) is a promising candidate for Coronavirus disease of 2019 (COVID‐19) treatment. The optimal dosing of HCQ is unknown. Our goal was to integrate historic and emerging pharmacological and toxicity data to understand safe and efficacious HCQ dosing strategies for COVID‐19 treatment. The data sources included were (i) longitudinal clinical, pharmacokinetic (PK), and virologic data from patients with severe acute respiratory syndrome‐2 (SARS‐CoV‐2) infection who received HCQ with or without azithromycin (n = 116), (ii) in vitro viral replication data and SARS‐CoV‐2 viral load inhibition by HCQ, (iii) a population PK model of HCQ, and (iv) a model relating chloroquine PKs to corrected QT (QTc) prolongation. A mechanistic PK/virologic/QTc model for HCQ was developed and externally validated to predict SARS‐CoV‐2 rate of viral decline and QTc prolongation. SARS‐CoV‐2 viral decline was associated with HCQ PKs (P < 0.001). The extrapolated patient half‐maximal effective concentration (EC50) was 4.7 µM, comparable to the reported in vitro EC50s. HCQ doses > 400 mg b.i.d. for ≥5 days were predicted to rapidly decrease viral loads, reduce the proportion of patients with detectable SARS‐CoV‐2 infection, and shorten treatment courses, compared with lower dose (≤ 400 mg daily) regimens. However, HCQ doses > 600 mg b.i.d. were also predicted to prolong QTc intervals. This prolongation may have clinical implications warranting further safety assessment. Due to COVID‐19's variable natural history, lower dose HCQ regimens may be indistinguishable from controls. Evaluation of higher HCQ doses is needed to ensure adequate safety and efficacy.
How family treatment can help break the CPS cycle
Authors: Knopf Alison , Enos Gary
Published: April 2020

Substance use disorders (SUDs) are a leading cause of child removal due to child welfare and criminal justice agencies. But if SUD treatment programs cooperate with, instead of battle, these agencies for the benefit of children and families, the families are more likely to stay together, and the mothers more likely to recover.
Morphology, Motility, and Cytoskeletal Architecture of Breast Cancer Cells Depend on Keratin 19 and Substrate
Authors: Lam Van K. , Sharma Pooja , Nguyen Thanh , Nehmetallah Georges , Raub Christopher B. , Chung Byung Min
Published: April 2020

Cancer cells gain motility through events that accompany modulation of cell shape and include altered expression of keratins. However, the role of keratins in change of cancer cell architecture is not well understood. Therefore, we ablated the expression of keratin 19 (K19) in breast cancer cells of the MDA‐MB‐231 cell line and found that cells lacking K19 become more elongated in culture, with morphological reversion toward the parental phenotype upon transduction of KRT19. Also, the number of actin stress fibers and focal adhesions were significantly reduced in KRT19 knockout (KO) cells. The altered morphology of KRT19 KO cells was then characterized quantitatively using digital holographic microscopy (DHM), which not only confirmed the phenotypic change of KRT19 KO cells but also identified that the K19‐dependent morphological change is dependent on the substrate type. A new quantitative method of single cell analysis from DHM, via average phase difference maps, facilitated evaluation of K19–substrate interactive effects on cell morphology. When plated on collagen substrate, KRT19 KO cells were less elongated and resembled parental cells. Assessing single cell motility further showed that while KRT19 KO cells moved faster than parental cells on a rigid surface, this increase in motility became abrogated when cells were plated on collagen. Overall, our study suggests that K19 inhibits cell motility by regulating cell shape in a substrate‐dependent manner. Thus, this study provides a potential basis for the altered expression of keratins associated with change in cell shape and motility of cancer cells. © 2020 International Society for Advancement of Cytometry
Hypochloraemia and 30 day readmission rate in patients with acute decompensated heart failure
Authors: Marchenko Roman , Sigal Adam , Wasser Thomas E. , Reyer Jessica , Green Jared , Mercogliano Christopher , Khan Muhammad Sohail , Donato Anthony A.
Published: April 2020

Aims

Despite recent advances in guideline‐directed therapy, rehospitalization rates for acute decompensated heart failure (ADHF) remain high. Recently published studies demonstrated the emerging role of hypochloraemia as a predictor of poor outcomes in patients with ADHF. This study sought to determine the correlation between low serum chloride and 30 day hospital readmission in patients with ADHF.

Methods and results

We retrospectively reviewed electronic medical records of 1504 patients who were admitted to one 700 bed US tertiary care centre with the diagnosis of ADHF between June 2013 and December 2014. Of the 1504 reviewed records, 1241 were selected for further analysis. Hypochloraemia (either on admission or at discharge) was identified in 289 patients (23.3%) and was associated with significantly higher 30 day hospital readmission rate or death (42.2% vs. 33.7%, P = 0.008). This association persisted in multivariate analysis when controlling for serum sodium, weight loss, diuretic dose, adjunct thiazide use, serum blood urea nitrogen, and BNP levels (OR: 1.35, 95% CI: 1.02–1.77, P = 0.033); however, the predictive value of the overall model was low (Naglkerke R2 = 0.040). Hypochloraemia was also found to be associated with increased 12 month mortality in our cohort (31.4% vs. 20.2%, P = 0.015) that correlates with the results of previously published studies.

Conclusions

Low serum chloride measured in patients admitted for ADHF is independently but weakly associated with increased 30 day readmission rate and demonstrated low predictive value as a potential biomarker in this cohort.
Predicting sustained ventricular arrhythmias in dilated cardiomyopathy: a meta‐analysis and systematic review
Authors: Sammani Arjan , Kayvanpour Elham , Bosman Laurens P. , Sedaghat‐Hamedani Farbod , Proctor Tanja , Gi Weng‐Tein , Broezel Alicia , Jensen Katrin , Katus Hugo A. , te Riele Anneline S.J.M. , Meder Benjamin , Asselbergs Folkert W.
Published: April 2020

Aims

Patients with non‐ischaemic dilated cardiomyopathy (DCM) are at increased risk of sudden cardiac death. Identification of patients that may benefit from implantable cardioverter‐defibrillator implantation remains challenging. In this study, we aimed to determine predictors of sustained ventricular arrhythmias in patients with DCM.

Methods and results

We searched MEDLINE/Embase for studies describing predictors of sustained ventricular arrhythmias in patients with DCM. Quality and bias were assessed using the Quality in Prognostic Studies tool, articles with high risk of bias in ≥2 areas were excluded. Unadjusted hazard ratios (HRs) of uniformly defined predictors were pooled, while all other predictors were evaluated in a systematic review. We included 55 studies (11 451 patients and 3.7 ± 2.3 years follow‐up). Crude annual event rate was 4.5%. Younger age [HR 0.82; 95% CI (0.74–1.00)], hypertension [HR 1.95; 95% CI (1.26–3.00)], prior sustained ventricular arrhythmia [HR 4.15; 95% CI (1.32–13.02)], left ventricular ejection fraction on ultrasound [HR 1.45; 95% CI (1.19–1.78)], left ventricular dilatation (HR 1.10), and presence of late gadolinium enhancement [HR 5.55; 95% CI (4.02–7.67)] were associated with arrhythmic outcome in pooled analyses. Prior non‐sustained ventricular arrhythmia and several genotypes [mutations in Phospholamban (PLN), Lamin A/C (LMNA), and Filamin‐C (FLNC)] were associated with arrhythmic outcome in non‐pooled analyses. Quality of evidence was moderate, and heterogeneity among studies was moderate to high.

Conclusions

In patients with DCM, the annual event rate of sustained ventricular arrhythmias is approximately 4.5%. This risk is considerably higher in younger patients with hypertension, prior (non‐)sustained ventricular arrhythmia, decreased left ventricular ejection fraction, left ventricular dilatation, late gadolinium enhancement, and genetic mutations (PLN, LMNA, and FLNC). These results may help determine appropriate candidates for implantable cardioverter‐defibrillator implantation.
Facile Methods for the Synthesis of 8‐Ylidene‐1,2,3,8‐tetrahydrobenzazecines
Authors: Titov Alexander A. , Kobzev Maxim S. , Borisova Tatiana N. , Listratova Anna V. , Evenko Tatiana V. , Varlamov Alexey V. , Voskressensky Leonid G.
Published: April 2020

We have elaborated a general and simple microwave‐assisted method for the synthesis of original 8‐ylidene decorated benzazecines. We have shown that under the action of electron‐deficient alkynes in acetic acid the starting benzoannulated azacyclic allenes or 1‐alkyl(benzyl)‐1‐phenylethynyl‐substituted isoquinolines underwent transformations leading to benzazecines in high yields. In acetic acid all reactions proceeded smoothly to give target products, some of which were isolated as a mixture of E/Z‐isomers. Reactions with methyl propiolate in hexaflouroisopropanol (HFIP) featured regioselectivity and provided only E‐isomer of 8‐ylidene substituted benzazecines, whereas in case of acetylacetylene the sole products were azacyclic allenes. The key structure was unambiguously assigned by the means of X‐ray crystallography.
A study on the responsiveness of the environment to international trade, energy consumption, and economic growth. The case of Ghana
Authors: Boamah Kofi Baah , Du Jianguo , Xu Lingyan , Nyarko Mensah Claudia , Khan Muhammad Aamir Shafique , Allotey Daniel Kpakpoe
Published: April 2020

The study examined the responsiveness of the environment of Ghana to changes in key economic indicators such as the international trade, energy consumption, urbanization, economic growth, and financial development. Our study utilized the ecological footprint as the indicator for environmental degradation as it encompasses the entire ecosystem that supports humankind consumption and activities. Consequently, the use of ecological footprint gives a clear and a bigger picture of environmental degradation than any individual pollutant(s). This study takes into cognizance the influence of structural break in the time series variables. The findings from the dynamic ordinary least square (DOLS) established the existence of an inverted N‐shaped environmental degradation‐economic growth relationship for Ghana under the cubic EKC framework. The ARDL bound testing approach confirmed the presence of long‐run cointegration among the variables. Furthermore, the bootstrap causality revealed a unidirectional causality running from energy consumption to export and urbanization to export. Our study, therefore, advocates for the production and consumption of enhanced energy‐efficient products and commodities among the populace of Ghana.