bluuebunny/crossref_metadata_2025 huggingface dataset:
Analyses of Neanderthal introgression suggest that Levantine and southern Arabian populations have a shared population history
Authors: Vyas Deven N. , Mulligan Connie J.
Published: March 2019

Objectives

Modern humans are thought to have interbred with Neanderthals in the Near East soon after modern humans dispersed out of Africa. This introgression event likely took place in either the Levant or southern Arabia depending on the dispersal route out of Africa that was followed. In this study, we compare Neanderthal introgression in contemporary Levantine and southern Arabian populations to investigate Neanderthal introgression and to study Near Eastern population history.

Materials and Methods

We analyzed genotyping data on >400,000 autosomal SNPs from seven Levantine and five southern Arabian populations and compared these data to those from populations from around the world including Neanderthal and Denisovan genomes. We used f4 and D statistics to estimate and compare levels of Neanderthal introgression between Levantine, southern Arabian, and comparative global populations. We also identified 1,581 putative Neanderthal‐introgressed SNPs within our dataset and analyzed their allele frequencies as a means to compare introgression patterns in Levantine and southern Arabian genomes.

Results

We find that Levantine and southern Arabian populations have similar levels of Neanderthal introgression to each other but lower levels than other non‐Africans. Furthermore, we find that introgressed SNPs have very similar allele frequencies in the Levant and southern Arabia, which indicates that Neanderthal introgression is similarly distributed in Levantine and southern Arabian genomes.

Discussion

We infer that the ancestors of contemporary Levantine and southern Arabian populations received Neanderthal introgression prior to separating from each other and that there has been extensive gene flow between these populations.
Schutzgruppenfreie Synthese von sequenzdefinierten Makromolekülen mittels präziser λ‐orthogonaler Photochemie
Authors: Konrad Waldemar , Fengler Christian , Putwa Sarrah , Barner‐Kowollik Christopher
Published: March 2019

Basierend auf einer lichtinduzierten Methode, die keine Schutzgruppenchemie erfordert, werden monodisperse sequenzdefinierte lineare Makromoleküle über ein einzigartiges photochemisches Vorgehen erzeugt. Ausgehend von einer symmetrischen Kerneinheit werden präzise Makromoleküle mit Molekulargewichten von bis zu 6257.10 g mol−1 über ein Zweimonomersystem erhalten. Der iterative Ansatz für das Kettenwachstum wird über die erste Monomereinheit, die zu einem ein auf sichtbares Licht reagierendes, pyrenfunktionalisiertes, Tetrazol und zum anderem ein auf UV‐Strahlung reagierendes Dien trägt, ermöglicht. Das zweite Monomer ist mit einer Carbonsäure und einem Fumarat ausgestattet. Beide lichtinduzierte Kettenwachstumsreaktionen werden λ‐orthogonal durchgeführt. Dabei wird die jeweilige lichtempfindliche Gruppe selektiv angeregt und dadurch Schutzgruppenchemie vermieden. Die detaillierte Charakterisierung jeder sequenzdefinierten Kette, die über Größenausschlusschromatographie (SEC), hochauflösende Elektrospray‐Ionisations‐Massenspektrometrie (ESI‐MS) und NMR‐Spektroskopie durchgeführt wird, bestätigt den monodispersen Charakter der Makromoleküle.
Graphit‐ und‐Silicium‐Anoden für Lithiumionen‐ Hochenergiebatterien
Authors: Chae Sujong , Choi Seong‐Hyeon , Kim Namhyung , Sung Jaekyung , Cho Jaephil
Published: March 2019

Silicium (Si) wird als ein vielversprechendes Anodenmaterial angesehen, mit dessen Hilfe die theoretische Kapazitätsgrenze kohlehaltiger Anodenmaterialien überwunden werden kann. Beim Problem der starken Volumenänderung als Folge der Lithiierung/Delithiierung brachte die Anwendung von Nanomethoden für Si‐Anoden einige Fortschritte. Weniger Erfolg hatte man bei der praktischen Anwendung von Si‐Anoden in kommerziellen Lithiumionen‐Batterien (LIBs). Vor dem Hintergrund eines wachsenden Bedarfs in vielen Bereichen wird der gemeinsame Einsatz des Si mit Graphit als eine wirtschaftlich sinnvolle Methode für die Realisierung hoher Energien diskutiert. Wir erörtern hier die Notwendigkeit der Kombination von Graphit und Si für die Kommerzialisierung und werden die Entwicklung von Graphit/Si‐Anoden im Detail darstellen. Behandelt werden typische Si‐Anoden, die für Graphitblend‐Elektroden verwendet werden und, geordnet nach der jeweiligen Synthesemethode, die Aufbaustrategien für Graphit/Si‐Komposite. Die Kriterien für den Graphit/Si‐Einsatz werden systematisch dargestellt. Zum Abschluss machen wir Vorschläge für die Kommerzialisierung von Graphit/Si‐Kombinationen.
Designing Hydrogen‐Bonded Organic Frameworks (HOFs) with Permanent Porosity
Authors: Hisaki Ichiro , Xin Chen , Takahashi Kiyonori , Nakamura Takayoshi
Published: March 2019

Designing organic components that can be used to construct porous materials enables the preparation of tailored functionalized materials. Research into porous materials has seen a resurgence in the past decade as a result of finding of self‐standing porous molecular crystals (PMCs). Particularly, a number of crystalline systems with permanent porosity that are formed by self‐assembly through hydrogen bonding (H‐bonding) have been developed. Such systems are called hydrogen‐bonded organic frameworks (HOFs). Herein we systematically describe H‐bonding patterns (supramolecular synthons) and molecular structures (tectons) that have been used to achieve thermal and chemical durability, a large surface area, and functions, such as selective gas sorption and separation, which can provide design principles for constructing HOFs with permanent porosity.
Globular Polymer Grafts Require a Critical Size for Efficient Molecular Sieving of Enzyme Substrates
Authors: McNelles Stuart A. , Marando Victoria M. , Adronov Alex
Published: March 2019

A series of 2,2‐bis(hydroxymethyl)propionic acid dendrons of generation 2 through 8 having a strained cyclooctyne at the core and hydroxy groups at the periphery were prepared by a divergent method and used to functionalize azide‐decorated α‐chymotrypsin. The ability of the appended dendrons to selectively block enzyme activity (through a molecular sieving effect) was investigated using a small molecule substrate (benzoyl‐l‐tyrosine p‐nitroanilide), as well as two proteins of different size (casein and bovine serum albumin). Additionally, the ability of dendrons to block complexation with a chymotrypsin antagonist, α‐antichymotrypsin, was investigated, and it was found that the dendron coating effectively prevented inhibition by this antagonist. We found that a critical generation is required to achieve efficient sieving with bis‐MPA dendrons, which illustrates the importance of macromolecular architecture and size in the shielding of proteins.
Spontaneous Resolution by Crystallization of an Octanuclear Iron(III) Complex Using Only Racemic Reagents
Authors: Lazarou Konstantinos A. , González‐Nieves Karilys , Chakraborty Indranil , Raptis Raphael G.
Published: March 2019

The P and M enantiomers of the octanuclear [Fe8(μ4‐O)4(μ‐4‐Cl‐pz)12Cl4] complex, having T symmetry, were resolved by temporary substitution of chloride ligands by racemic 4‐sBu‐phenolates and subsequent crystallization, where the (S)‐ and (R)‐phenolates coordinate selectively to the M and P complexes, respectively. The complexes were characterized by circular dichroism analysis and X‐ray structure determination. This work constitutes a rare example of enantiomeric recognition resulting in spontaneous resolution upon crystallization.
Borane Adducts of Hydrazoic Acid and Organic Azides: Intermediates for the Formation of Aminoboranes
Authors: Bläsing Kevin , Bresien Jonas , Labbow René , Michalik Dirk , Schulz Axel , Thomas Max , Villinger Alexander
Published: March 2019

The reaction of HN3 with the strong Lewis acid B(C6F5)3 led to the formation of a very labile HN3⋅B(C6F5)3 adduct, which decomposed to an aminoborane, H(C6F5)NB(C6F5)2, above −20 °C with release of molecular nitrogen and simultaneous migration of a C6F5 group from boron to the nitrogen atom. The intermediary formation of azide–borane adducts with B(C6F5)3 was also demonstrated for a series of organic azides, RN3 (R=Me3Si, Ph, 3,5‐(CF3)2C6H3), which also underwent Staudinger‐like decomposition along with C6F5 group migration. In accord with experiment, computations revealed rather small barriers towards nitrogen release for these highly labile azide adducts for all organic substituents except R=Me3Si (m.p. 120 °C, Tdec=189 °C). Hydrolysis of the aminoboranes provided C6F5‐substituted amines, HN(R)(C6F5), in good yields.
Reversible Oxygen Redox Chemistry in Aqueous Zinc‐Ion Batteries
Authors: Wan Fang , Zhang Yan , Zhang Linlin , Liu Daobin , Wang Changda , Song Li , Niu Zhiqiang , Chen Jun
Published: March 2019

Rechargeable aqueous zinc‐ion batteries (ZIBs) are promising energy‐storage devices owing to their low cost and high safety. However, their energy‐storage mechanisms are complex and not well established. Recent energy‐storage mechanisms of ZIBs usually depend on cationic redox processes. Anionic redox processes have not been observed owing to the limitations of cathodes and electrolytes. Herein, we describe highly reversible aqueous ZIBs based on layered VOPO4 cathodes and a water‐in‐salt electrolyte. Such batteries display reversible oxygen redox chemistry in a high‐voltage region. The oxygen redox process not only provides about 27 % additional capacity, but also increases the average operating voltage to around 1.56 V, thus increasing the energy density by approximately 36 %. Furthermore, the oxygen redox process promotes the reversible crystal‐structure evolution of VOPO4 during charge/discharge processes, thus resulting in enhanced rate capability and cycling performance.
Switching from linear to cyclic δ‐Polyvalerolactone synthesized via zeolitic imidazolate framework as a catalyst: A promising approach
Authors: Naz Farah , Mousavi Bibimaryam , Luo Zhixiong , Jabbour Christia , Heynderickx Philippe M. , Chaemchuen Somboon , Verpoort Francis
Published: March 2019

A series of spray dried zeolitic imidazolate frameworks (ZIFs = ZIF‐8, ZIF‐67, and Zn/Co‐ZIF) are used as a catalyst for the bulk ring‐opening polymerization of δ‐valerolactone without any co‐catalyst to generate polyvalerolactone. Interestingly, using the same catalyst under the same reaction conditions could manipulate the structure of the product polymer, and thus its physical properties. Thus, using a dried substrate leads to the formation of the cyclic polymer while a linear polymer was formed on using the commercially available substrate. An activated monomer mechanism has been suggested where the propagating zinc alkoxide undergoes an intramolecular transesterification to release cyclic or linear polyvalerolactone. The ROP of δ‐VL without drying shows that the polymeric zwitterions have little tendency to cyclize in the presence of moisture. At 140 °C, ZIF‐8 shows a superior catalytic activity resulting in the production of cyclic polyvalerolactone having a high molecular weight as compared to ZIF‐67 or Zn/Co‐ZIF due to the presence of highly active sites. The catalyst could be recycled and reused without any significant loss of catalytic activity.
Facile synthesis of inorganic–organic Fe2W18Fe4@NiO@CTS hybrid nanocatalyst induced efficient performance in oxidative desulfurization of real fuel
Authors: Rezvani Mohammad Ali , Maleki Zeynab
Published: March 2019

In this work, a new nanocatalyst, Fe2W18Fe4@NiO@CTS, was synthesized by the reaction of sandwich‐type polyoxometalate (Fe2W18Fe4), nickel oxide (NiO), and chitosan (CTS) via sol–gel method. The assembled nanocatalyst was systematically characterized by FT‐IR, UV–vis, XRD, SEM, and EDX analysis. The catalytic activity of Fe2W18Fe4@NiO@CTS was tested on oxidative desulfurization (ODS) of real gasoline and model fuels. The experimental results revealed that the levels of sulfur content and mercaptan compounds of gasoline were lowered with 97% efficiency. Also, the Fe2W18Fe4@NiO@CTS nanocatalyst demonstrated an outstanding catalytic performance for the oxidation of dibenzothiophene (DBT) in the model fuel. The major factors that influence the desulfurization efficiency and the kinetic study of the ODS reactions were fully detailed and discussed. The probable ODS pathway was proposed via the electrophilic mechanism on the basis of the electrophilic characteristic of the metal‐oxo‐peroxo intermediates. The prepared nanocatalyst could be reused for 5 successive runs without any appreciable loss in its catalytic activity. As a result, the current study suggested the potential application of the Fe2W18Fe4@NiO@CTS hybrid nanocatalyst as an ideal candidate for removal of sulfur compounds from fuel.
Sustainable biocarbon as an alternative of traditional fillers for poly(butylene terephthalate)‐based composites: Thermo‐oxidative aging and durability
Authors: Chang Boon Peng , Mohanty Amar Kumar , Misra Manjusri
Published: March 2019

Sustainable biocomposites have gained considerable interest as an alternative to conventional composites in recent years due to their cost‐effectiveness and environmental friendliness. The aim of this study was to investigate the performance and durability behavior of biocomposites from sustainable biocarbon (BC) as compared to conventional established fillers. The poly(butylene terephthalate) (PBT) and its composites reinforced with BC, talc, and glass fiber (GF) were prepared and the durability performances was investigated. The study showed that BC/PBT biocomposites provided a lighter weight alternative to traditionally used fillers. After undergoes thermo‐oxidative aging, the mechanical properties of BC/PBT biocomposite were deteriorated. The GF/PBT showed the most stable in retaining its mechanical properties in comparison to the talc/PBT and BC/PBT. The aging behavior and mechanism of the PBT composites were discussed. This study provides further insight on the durability‐related properties progression of biocomposites as compared to traditional used fillers. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47722.
Enhancing resistance of poly(ether ketone ketone) to high‐temperature steam through crosslinking and crystallization control
Authors: Veazey Dustin , Hsu Tim , Gomez Enrique D.
Published: March 2019

Poly(aryl ether ketone)s (PAEKs) are promising materials for harsh environments, such as in high‐temperature steam applications. Here, the effect of high‐temperature steam on the crystallinity and mechanical properties of existing poly(ether ether ketone) (PEEK) and PEKK(T/I) polymers is investigated. Differential scanning calorimetry (DSC), wide‐angle X‐ray scattering or diffraction (WAXD), and dynamic mechanical analysis experiments show these materials undergo significant crystallization and reorganization after prolonged exposure to steam and suffer from embrittlement. In addition, we show that xanthydrol‐based crosslinks can provide the dimensional stability and stabilize the PEKK crystal structure. Mechanical tests demonstrate that the ductility is preserved for longer exposures to steam compared to neat PEKK, whereas DSC and WAXD data indicate xanthydrol crosslinks effectively stabilize the crystal structure against steam‐assisted crystallization. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47727.
The Use of Eye Tracking as a Biomarker of Treatment Outcome in a Pilot Randomized Clinical Trial for Young Children with Autism
Authors: Bradshaw Jessica , Shic Frederick , Holden Anahita N. , Horowitz Erin J. , Barrett Amy C. , German Tamsin C. , Vernon Ty W.
Published: March 2019

There is a pressing need for objective, quantifiable outcome measures in intervention trials for children with autism spectrum disorder (ASD). The current study investigated the use of eye tracking as a biomarker of treatment response in the context of a pilot randomized clinical trial of treatment for young children with ASD. Participants included 28 children with ASD, aged 18–48 months, who were randomized to one of two conditions: Pivotal Response Intervention for Social Motivation (PRISM) or community treatment as usual (TAU). Eye‐tracking and behavioral assessment of developmental functioning were administered at Time 1 (prior to randomization) and at Time 2 (after 6 months of intervention). Two well‐established eye‐tracking paradigms were used to measure social attention: social preference and face scanning. As a context for understanding relationships between social attention and developmental ability, we first examined how scanning patterns at Time 1 were associated with concurrent developmental functioning and compared to those of 23 age‐matched typically developing (TD) children. Changes in scanning patterns from Time 1 to Time 2 were then compared between PRISM and TAU groups and associated with behavioral change over time. Results showed that the social preference paradigm differentiated children with ASD from TD children. In addition, attention during face scanning was associated with language and adaptive communication skills at Time 1 and change in language skills from Time 1 to Time 2. These findings highlight the importance of examining targeted biomarkers that measure unique aspects of child functioning and that are well‐matched to proposed mechanisms of change. Autism Research 2019, 12: 779–793. © 2019 International Society for Autism Research, Wiley Periodicals, Inc.

Lay Summary

Biomarkers have the potential to provide important information about how and why early interventions effect positive change for young children with ASD. The current study suggests that eye‐tracking measures of social attention can be used to track change in specific areas of development, such as language, and points to the need for targeted eye‐tracking paradigms designed to measure specific behavioral changes. Such biomarkers could inform the development of optimal, individualized, and adaptive interventions for young children with ASD.
Activation of Nrf2 signaling by Icariin protects against 6‐OHDA‐induced neurotoxicity
Authors: Zhu Li , Li DaiDi , Chen Ce , Wang GuoQing , Shi JingShan , Zhang Feng
Published: March 2019

Nerve damage is the main pathogenesis of neurodegenerative diseases. Recently, in search for a promising therapeutic target that could stop neurodegenerative diseases progression, the antioxidant signaling pathway regulated by transcription factor nuclear factor erythroid 2‐related factor 2 (Nrf2) has attracted new hopes. Icariin (ICA) exhibited a battery of pharmacological properties, including antioxidation, anti‐aging, and anti‐inflammation activities. Recent studies indicate ICA conferred neuroprotection against brain ischemic injury and neurodegenerative diseases. However, the mechanisms underlying ICA‐mediated neuroprotection remain unelucidated. This study aimed at analyzing whether ICA evoked neuroprotection against 6‐hydroxydopamine (6‐OHDA)‐induced neurotoxicity in PC12 cells and the mechanisms of action. ICA protected against 6‐OHDA‐induced neuronal damage, accompanied by the inhibition of cell apoptosis through the marked decreases in the Bax/Bcl‐2 ratio, cytochrome c release, and caspase‐3 cleavage. In addition, the activation of Nrf2 signaling pathway was responsible for ICA‐mediated neuroprotection. First, ICA relieved reactive oxygen species accumulation and increased superoxide dismutase generation via the activation of Nrf2 signaling. Second, Nrf2 knockdown by siRNA reversed ICA‐mediated neuroprotection. Together, these results suggested ICA‐mediated neuroprotection might be attributable to the activation of Nrf2 pathway via antioxidative signaling pathways.
Neues Verbindungskonzept aus bewehrtem Polymerfeinbeton für Faserverbund‐ und Holzwerkstoffe
Authors: Schmeck Michel , Arendt Stephan , La Magna Riccardo , Schmid Volker , Gengnagel Christoph
Published: March 2019

Entscheidend für die Tragfähigkeit, Wirtschaftlichkeit und die Gestaltung von schlanken Konstruktionen aus Holz‐ oder Faserverbundkunststoffen (FVK) sind i. d. R. die Verbindungen. In diesem Beitrag wird ein neuartiges Verbindungskonzept für Stabwerkskonstruktionen aus Holz‐ oder FVK vorgestellt. Eine wichtige Eigenschaft dabei ist eine reversible Montagemöglichkeit. Ein weiterer Vorteil ist die Weiterleitung hoher Beanspruchungen ohne Querschnittsvergrößerungen. Das Konzept basiert auf einer formschlüssigen Kraftübertragung durch Verzahnung in Kombination mit GFK‐bewehrtem Polymerbeton. Der Werkstoff ermöglicht aufgrund seiner exzellenten Verbundeigenschaften mit Holz und FVK, seiner Tragfähigkeit sowie seiner freien Formbarkeit die Entwicklung einer vollständig neuartigen Verbindungstechnologie. Am Beispiel eines biegesteifen Längsstoßes werden die Potenziale und Herausforderungen der neuen Bauweise in Hinblick auf Detailentwicklung und Analyse aufgezeigt und diskutiert. Für den neuartigen, kaltvergossenen Verbindungsknoten erfolgten umfangreiche numerische und experimentelle Traglastuntersuchungen, die hier vorgestellt werden. Ebenfalls dargestellt werden Ansätze einer computergestützten Geometriegenerierung und Fertigung des Knotens (Rapid Prototyping) sowie weitere Entwicklungsstrategien für das Gesamtkonzept.
Embelin attenuates cisplatin‐induced nephrotoxicity: Involving inhibition of oxidative stress and inflammation in addition with activation of Nrf‐2/Ho‐1 pathway
Authors: Qin Xuexiang , Meghana Kakani , Sowjanya Nelluri Lakshmi , Sushma Katakam Revathi , Krishna Ch Gopala , Manasa Jagarlamudi , Sita Gadamsetty Jaya Alekhya , Gowthami Motati , Honeyshmitha Dronadula , Srikanth Gadiparthi , SreeHarsha Nagaraja
Published: March 2019

In kidneys, elevated levels of inflammatory cytokines and oxidative stress were observed in nephrotoxicity triggered by cisplatin. Embelin has the anti‐inflammatory property. It also got anti‐tumorigenic and antioxidant properties. In this research, we analyzed the actions of embelin on nephrotoxicity triggered by cisplatin and vital actions by which it increases antioxidant actions and corrects the inflammation after embelin administration during nephrotoxicity triggered by cisplatin. Kidney function markers including blood urea nitrogen; serum creatinine; the markers of oxidative stress like malondialdehyde (MDA), antioxidant systems like glutathione, superoxide dismutase, glutathione S‐transferase, catalase, and glutathione reductase; inflammation markers like nuclear factor‐κB (NF‐κB), tumor necrosis factor‐α (TNF‐α), and interleukin‐1 beta (IL‐1β); and the extent of nuclear factor‐erythroid‐2 p45‐related factor‐2 (Nrf2) and heme oxygenase‐1 (HO‐1) were determined. Histopathology studies of kidneys were also used to analyze nephrotoxicity induced by cisplatin. Treatment with embelin (25 and 50 mg/kg) upgrades the function of kidneys, by elevating antioxidant levels and reducing the MDA level in cisplatin‐administered rats. Embelin treatment demonstrated a significant curtailment of oxidative stress as well as increased the activities of antioxidant enzymes, endogenously. Cisplatin upregulates cytokines (i.e., TNF‐α and IL‐1β) and NF‐κB, and downregulates Nrf2 and HO‐1. Embelin treatment also reduced the infiltration of neutrophils in the renal tubules and thus reduced the level of histological impairment. The outcome of this study implements that the signaling pathway of Nrf2/HO‐1 may be the principal mechanism of embelin for protection from nephrotoxicity triggered by cisplatin, and thus, embelin diminishes oxidative stress and inflammation by impeding NF‐κB. © 2019 BioFactors, 45(3):471–478, 2019
Meta-analysis of patient-reported outcomes after laparoscopic versus open inguinal hernia repair
Authors: Patterson T J , Beck J , Currie P J , Spence R A J , Spence G
Published: March 2019

Background

Inguinal hernia repair is a common low-risk intervention. Patient-reported outcomes (PROs) are being used increasingly as primary outcomes in clinical trials. The aim of this study was to review and meta-analyse the PROs in RCTs comparing laparoscopic versus open inguinal hernia repair techniques in adult patients.

Methods

A systematic review and meta-analysis was carried out in accordance with PRISMA guidelines. Only RCTs in peer-reviewed journals were considered. PubMed, Ovid Embase, Scopus and the Cochrane Library were searched. In addition, four trial registries were searched. The search interval was between 1 January 1998 and 1 May 2018. Identified publications were reviewed independently by two authors. The review was registered in the PROSPERO database (CRD42018099552). Bias was assessed using the Cochrane Collaboration risk-of-bias tool.

Results

Some 7192 records were identified, from which 58 unique RCTs were selected. Laparoscopic hernia repair was associated with significantly less postoperative pain in three intervals: from 2 weeks to within 6 months after surgery (risk ratio (RR) 0·74, 95 per cent c.i. 0·62 to 0·88), 6 months to 1 year (RR 0·74, 0·59 to 0·93) and 1 year onwards (RR 0·62, 0·47 to 0·82). Paraesthesia (RR 0·27, 0·18 to 0·40) and patient-reported satisfaction (RR 0·91, 0·85 to 0·98) were also significantly better in the laparoscopic repair group.

Conclusion

The data and analysis reported in this study reflect the most up-to-date evidence available for the surgeon to counsel patients. It was constrained by heterogeneity of reporting for several outcomes.
Why Directors Should Embrace a Merger Mindset
Authors: Henman Linda
Published: March 2019

Dr. Linda Henman is the author of six books, including Tough Calls: How to Move Beyond Indecision and Good Intentions. She has more than 35 years of experience working with executives and boards in Fortune 500 companies and small businesses to help them exceed their strategic objectives by maximizing talent. In this article, Dr. Henman explores the key psychological forces that come into play when board members seek to shepherd their organizations through mergers and acquisitions.
Long‐term exposure to high altitude attenuates verbal and spatial working memory: Evidence from an event‐related potential study
Authors: Ma Hailin , Zhang Delong , Li Xuebing , Ma Huifang , Wang Niannian , Wang Yan
Published: March 2019

Introduction

This study aimed to determine the neurocognitive basis underlying the effects of long‐term high‐altitude (HA) exposure on working memory (WM).

Methods

Using event‐related potentials (ERPs), we compared the performance of an HA group (individuals who had lived at HA for 3 years but were born and raised at low altitude [LA]) to that of an LA group (individuals who had only lived at LA) on verbal and spatial n‐back tasks (i.e., 1‐ and 2‐back memory load).

Results

Response accuracy of the HA group was significantly decreased in comparison to the LA group in both the verbal and spatial 2‐back tasks. The P2 amplitude was larger in the HA than in the LA group in the spatial, but not the verbal 2‐back task. A smaller late‐positive potential (LPP) amplitude was found in the HA group in both the verbal and spatial 2‐back tasks.

Conclusions

These results suggest that HA impairs the matching (P2) process in spatial WM tasks and the maintenance (LPP) process in both verbal and spatial WM tasks, indicating that HA had a different effect on verbal and spatial 2‐back task performance.
The roles of alpha oscillation in working memory retention
Authors: Wianda Elvis , Ross Bernhard
Published: March 2019

Introduction

Brain processes of working memory involve oscillatory activities at multiple frequencies in local and long‐range neural networks. The current study addressed the specific roles of alpha oscillations during memory encoding and retention, supporting the hypothesis that multiple functional mechanisms of alpha oscillations exist in parallel.

Method

We recorded magnetoencephalography (MEG) in 25 healthy young adults, who performed a variant of a Sternberg working memory task. A sequential list of five consonant letters was visually presented and was followed after a 2.0 s retention interval by a probe of a pair of two letters from the study list. Participants responded whether the probe pair was in same or reversed order in the list.

Result

Reaction time (RT) was shortest for the first letters in the list, increased with increasing serial position, and shorter for the last position. RT was substantially longer for the probe in reversed order. Time‐frequency analysis of the MEG revealed event‐related desynchronization (ERD) of alpha oscillations during the encoding interval and an alpha power increase (ERS) during memory retention. Alpha ERD during encoding occurred at 10 Hz and ERS during retention at 12 Hz, suggesting different alpha mechanisms. Analysis of alpha coherence and alpha‐gamma cross‐spectral coupling, applied to MEG beamformer source activity, revealed connectivity across brain areas. Additionally, alpha‐gamma coupling identified centers of local computation. The connectivity between occipital and frontotemporal areas was correlated with alpha ERS during memory retention. Cross‐frequency coupling between alpha phase and gamma amplitude depicted a hierarchy of information flow from frontal to temporal and occipital brain areas.

Conclusion

Alpha decrease during encoding indicates an active state of visual processing, while subsequent ERS indicates inhibition of further visual input for protecting the memory, and phasic timing of temporal and occipital gamma oscillations is related to a long‐range working memory networks.
Strategic stakeholder management, environmental corporate social responsibility engagement, and financial performance of stigmatized firms derived from Chinese special environmental policy
Authors: Xu Jia , Wei Jiuchang , Lu Liangdong
Published: March 2019

We draw upon the stigma literature and strategic stakeholder management model to develop a framework capable of explaining the link between environmental corporate social responsibility (ECSR) engagement and financial performance of stigmatized firms, taking stakeholder‐oriented governance and density of local stigmatized firms into consideration. Using a uniquely compiled dataset of Chinese firms specifically monitored by the Ministry of Environmental Protection of China, we conducted propensity score matching analysis to estimate the impact of stigma on corporate financial performance and corporate environmental responsibility. The result shows that the financial performance of stigmatized firms is negatively affected by the stigma label, spurring them to engage in more ECSR than their peers to improve their legitimacy. Though ECSR engagement of stigmatized firms is found to be negatively associated with their financial performance in current study. Our results also confirm that (a) the financial performance of stigmatized firms is positively affected by two proxies for corporate stakeholder‐oriented governance (i.e., institutional ownership and corporate transparency) and negatively affected by the density of local stigmatized firms; (b) corporate stakeholder‐oriented governance compensates for the negative effect of ECSR engagement; (c) high intensity of local stigmatized firms provides focal firms with an opportunity to improve their financial performance through ECSR engagement; and (d) the positive effects of corporate stakeholder‐oriented governance are diminished by the density of local stigmatized firms.
Effects of preheating on briquetting and subsequent hydrothermal pretreatment for enzymatic saccharification of wheat straw
Authors: Gong Chunxiao , Thomsen Sune Tjalfe , Thygesen Lisbeth G. , Felby Claus
Published: March 2019

Briquetting of plant biomass with low bulk density is an advantage for handling, transport, and storage of the material, and heating of the biomass prior to the briquetting facilitates the densification process and improves the physical properties of the briquettes. This study investigates the effects of preheating prior to briquetting of wheat straw (WS) on subsequent hydrothermal pretreatment and enzymatic conversion to fermentable sugars. WS (11% moisture content) was densified to briquettes under different conditions; without preheating or with preheating at 75 or 125°C for either 5 or 10 min. Subsequent hydrothermal pretreatment was done for both un‐briquetted WS and for briquettes. Enzymatic saccharification was afterwards performed for all samples. The results showed that as expected, nonpretreated WS briquettes gave very low sugar yields (22–29% of the cellulose content), even though preheating at 125°C prior to briquetting (without pretreatment) improved sugar yields somewhat. When combined with pretreatment, briquetting with preheating showed neutral or negative effects on sugar yield. This result suggests that moderate preheating (75°C for 5 min) before briquetting improved bulk density and compressive resistance of briquettes without impeding subsequent enzymatic conversion. However, excessive preheating (75 or 125°C for 10 min) before briquetting may result in irreversible structural modifications that hinder the interaction between biomass and water during pretreatment, thereby decreasing the accessibility of cellulose to enzymatic saccharification.
Influence of social stigma on subjective well‐being of persons with albinism in Ghana
Authors: Affram Adjeiwa Akosua , Teye‐Kwadjo Enoch , Gyasi‐Gyamerah Angela A.
Published: March 2019

Previous studies have shown that social stigma adversely affects quality of life. However, little research has assessed the influence of social stigma on subjective well‐being (SWB) of persons with albinism (PWA) in Ghana, and the role that perceived social support plays in this relationship. This study investigated the SWB of PWA in Ghana. Participants (N = 105) completed a survey questionnaire on social stigma, social support, and SWB. Results from structural equation modelling showed a significant negative association between social stigma and SWB. Perceived social support partially mediated the negative effect that social stigma has on SWB, with significant other support emerging as a reliable predictor of SWB in this sample. Results suggest that the population with albinism in Ghana is experiencing high levels of social stigma, which is adversely affecting its SWB. Social stigma seems to be preventing PWA from being accorded the needed social support by family and friends. The results highlight the importance of designing stigma‐reduction educational interventions that target social stigma at family, community, and societal levels.
Acute breathlessness with frank hemoptysis following catheter ablation for atrial fibrillation, a cause not so obvious
Authors: Waddingham Peter Henry , Chow Anthony Wai‐Cheong
Published: March 2019

Key Clinical Message

All clinicians prescribing amiodarone require knowledge of the challenging diagnosis and management of amiodarone‐induced pulmonary toxicity (APT), which is potentially fatal. APT should be considered early in all patients presenting with new respiratory symptoms and concurrent amiodarone therapy. Drug cessation and corticosteroid therapy can be highly effective once recognized.
Acute renal infarction, transient ischemic attack, and biventricular thrombi secondary to substance use disorder: A case report
Authors: Ghassemi Azadeh , Bharadia Juma , Liu Antonio
Published: March 2019

Key Clinical Message

Cocaine is the second most used illicit drug; cocaine induces platelet activation and formation of thrombus. Thrombotic effects of cocaine can lead to vascular injuries, cerebrovascular accident and myocardial infarct. Less common, cocaine use disorder leads to thrombi formation in both ventricles and renal artery infarct as seen in our patient.
Efficient Liquid‐Assisted Grinding Selective Aqueous Oxidation of Sulfides Using Supported Heteropolyacid Catalysts
Authors: Trombettoni Valeria , Franco Ana , Sathicq A. Gabriel , Len Christophe , Romanelli Gustavo P. , Vaccaro Luigi , Luque Rafael
Published: March 2019

The present work reports the preparation of 40MoAl200 and its full characterization using a number of analytical techniques (XRD, TEM, TGA, BET, EDX). Liquid‐assisted ball milling proved to be a key tool to achieve both the best efficiency of 40MoAl200 as a novel Keggin type catalyst in the selective sulfoxidation reaction and also for succeeding in its effective recovery and reuse. In addition, the liquid assisted grinding process was studied in detail evaluating the influence of different parameters such as frequency of rotation (rpm), number and size of the stainless steel balls used and reaction time. The use of aqueous hydrogen peroxide is essential as water proved to exert a crucial role to improve both yields and selectivity towards sulfoxide formation. The procedure was representatively extended to a number of substrates with the possibility to extend the scope of the system to produce sulfoxides in high yields (up to 95 %) and satisfactory selectivities (up to 80 %). The catalyst proved to be recoverable and reusable under the optimized reaction conditions.
Minimum Cross Diameter for C6–C10 Aromatic Compounds
Authors: Gonçalves Jonathan C. , Ferreira Alexandre F. P. , Rodrigues Alírio E.
Published: March 2019

The minimum cross diameter of organic species is highly important in catalyst and adsorbent design. In the aromatics industry, the size of the desired compound is the cornerstone of the commonly known shape‐selective processes. In spite of the paramount importance of the said sizes, information in the literature is scarce and inconsistent. A thorough methodology was developed using the commercial software ChemBio3D Ultra. The minimum cross diameter of 21 aromatic compounds was calculated including benzene, toluene, ethylbenzene, xylene isomers, ethyltoluene isomers, diethylbenzene isomers, ethylxylene isomers, and trimethylbenzene isomers.
Simulation of Turbulent Emulsification in a Sonolator Mixer: Interpretation of Drop Breakage Time
Authors: Bagkeris Ioannis , Michael Vipin , Prosser Robert , Kowalski Adam J.
Published: March 2019

The simulation of dilute emulsions in a model ACIP2 Sonolator is investigated using computational fluid dynamics and population balance methods. Two breakage frequency models are used that differ in the expression of the drop breakage time. Drop breakage modeling based on homogenous isotropic turbulence (HIT) shows poor agreement of the Sauter mean diameter when compared to the experiments; simulations with the empirical model from Alopaeus et al. yield better agreement. By perturbing the classical HIT spectrum, it is shown that the breakage time in the empirical model corresponds to a non‐isotropic energy spectrum. Such spectra have been observed in the non‐isotropic near field in a model A Sonolator, which provides a plausible explanation of why the empirical model performs better than the HIT‐based model.
Robust NiCo2O4/Superactivated Carbon Aqueous Supercapacitor with High Power Density and Stable Cyclability
Authors: Panja Tandra , Díez Noel , Mysyk Roman , Bhattacharjya Dhrubajyoti , Goikolea Eider , Carriazo Daniel
Published: March 2019

Herein, we investigate the performance of an aqueous asymmetric supercapacitor (AAS) assembled by using novel nanostructured NiCo2O4 as the positive electrode and a polymer‐derived superactivated carbon (SAC) as the negative electrode. The combination of both the nanostructured NiCo2O4 and the carbon with hierarchical porosity and ultrahigh specific surface area (above 3000 m2 g−1) led to excellent rate performances and long stability of the system. The optimization of the AAS device is further achieved through the variation of mass ratio between positive and negative electrodes. The optimized AAS full cell exhibits reversibility within the 0.0–1.5 V operative voltage region, delivering a specific cell capacity of 24.6 mAh g−1 at a current density of 1 A g−1. This results in a remarkable energy density of 13 Wh kg−1 at a power density of 26.2 kW kg−1 and an excellent cycling durability above 87 % of the initial capacity after 10,000 charge–discharge cycles.
Sensitivity limits for determining 1:1 binding constants from spectrophotometric titrations via global analysis
Authors: Kazmierczak Nathanael P. , Chew Joyce A. , Michmerhuizen Anna R. , Kim Seong Eun , Drees Zachary D. , Rylaarsdam Andrew , Thong Tasha , Van Laar Luke , Vander Griend Douglas A.
Published: March 2019

Monte Carlo simulations on UV‐vis titration data quantify how the precision of binding constant calculation deteriorates in strong binding regimes. For 1:1 binding, global analysis is reliable whenK[H]o < 1000, a significant improvement over previous recommendations. Initial concentration error generates the majority of the error in the calculated binding constant. We derive a novel experimental design formula to maximize binding constant precision over both strong and weak binding regimes and validate it through Monte Carlo simulations.
Efficient 1,3‐Oxazolidin‐2‐one Synthesis through Heterogeneous PdII‐Catalyzed Intramolecular Hydroamination of Propargylic Carbamates
Authors: Oschmann Michael , Placais Clotilde , Nagendiran Anuja , Bäckvall Jan‐E. , Verho Oscar
Published: March 2019

Herein, we present an operationally simple protocol for the cycloisomerization of propargylic carbamates in which a heterogeneous catalyst consisting of Pd species immobilized on amino‐functionalized siliceous mesocellular foam (PdII‐AmP‐MCF) is used. This Pd nanocatalyst displayed high efficiency at low catalyst loading and reaction temperatures, which allowed for the efficient and mild synthesis of a wide range of 1,3‐oxazolidin‐2‐one derivatives and related compounds. Moreover, it proved possible to re‐use the Pd nanocatalyst for several reactions, although a gradual decrease in activity was observed in the subsequent cycles.
Regiodivergent and Stereospecific Aziridine Opening by Copper‐Catalyzed Addition of Silicon Grignard Reagents
Authors: Yi Hong , Oestreich Martin
Published: March 2019

A stereospecific ring opening of various 2‐aryl‐substituted aziridines with silicon Grignard reagents under copper catalysis is reported. The regiochemical outcome is governed by the steric demand of the silicon nucleophile. The LiCl introduced with the magnesium reagent R3SiMgX⋅2 LiCl is shown to enhance the SN2‐type displacement of the carbon‐nitrogen bond by coordination to the aziridine nitrogen atom.
Clinical impact of using a more sensitive troponin assay in patients with acute chest pain
Authors: Wang Guangmei , Wang Jiali , Wu Shuo , Zheng Wen , Zhang He , Ma Jingjing , Zheng Jiaqi , Xu Feng , Chen Yuguo
Published: March 2019

Background

More sensitive troponin assays have the potential to better evaluate patients with suspected acute coronary syndrome (ACS). Meanwhile, they may result in avoidable diagnostic testing.

Hypothesis

Our aim was to determine the clinical impact of implementing a more sensitive cardiac troponin I (cTnI) assay in patients with acute non‐traumatic chest pain presenting to the emergency department (ED).

Methods

This is a pre‐post cohort study. A total of 1201 consecutive patients with acute non‐traumatic chest pain or equivalent ischemic symptoms suggestive of ACS were allocated to two groups according to the cTnI assay used. The outcomes included the ED length of stay (LOS), hospital admission rate, the use of procedures and the incidence of major adverse cardiac events (MACE) at 30 days.

Results

The introduction of the more sensitive troponin assay shortened ED LOS (odds ratio [OR] 0.39, 95% confidence interval [CI] 0.28‐0.54) regarding patients discharged home directly, increased the hospital admission rate (OR 1.43, 95% CI 1.12‐1.84), the use of echocardiography (OR 1.58, 95% CI 1.22‐2.06), coronary computed tomography angiography (OR 1.78, 95% CI 1.04‐3.06), coronary angiography (OR 1.53, 95% CI 1.10‐2.12) and percutaneous coronary intervention (OR 2.42, 95% CI 1.58‐3.70) regarding patients discharged or admitted. The incidence of MACE did not decrease significantly (OR 0.61, 95% CI 0.27‐1.37).

Conclusions

The introduction of the more sensitive troponin assay appeared to result in less time spent in the ED regarding patients discharged home directly, but prompted more hospitalizations and procedures without impacting the incidence of MACE.
Adolescent and young adult cancer survivorship: The new frontier for investigation
Authors: Hayashi Robert J.
Published: March 2019

Adolescent and young adult cancer survivors are at long‐term risk of early mortality. More research is needed to understand these risks and to develop effective interventions with the expectation that this group may be unique compared with other age groups.
Image‐based modeling of blood flow in cerebral aneurysms treated with intrasaccular flow diverting devices
Authors: Mut Fernando , Chung Bong Jae , Chudyk Jorge , Lylyk Pedro , Kadirvel Ramanathan , Kallmes David F. , Cebral Juan R.
Published: March 2019

Modeling the flow dynamics in cerebral aneurysms after the implantation of intrasaccular devices is important for understanding the relationship between flow conditions created immediately posttreatment and the subsequent outcomes. This information, ideally available a priori based on computational modeling prior to implantation, is valuable to identify which aneurysms will occlude immediately and which aneurysms will likely remain patent and would benefit from a different procedure or device.

In this report, a methodology for modeling the hemodynamics in intracranial aneurysms treated with intrasaccular flow diverting devices is described. This approach combines an image‐guided, virtual device deployment within patient‐specific vascular models with an immersed boundary method on adaptive unstructured grids. A partial mesh refinement strategy that reduces the number of mesh elements near the aneurysm dome where the flow conditions are largely stagnant was compared with the full refinement strategy that refines the mesh everywhere around the device wires.

The results indicate that using the partial mesh refinement approach is adequate for analyzing the posttreatment hemodynamics, at a reduced computational cost. The results obtained on a series of four cerebral aneurysms treated with different intrasaccular devices were in good qualitative agreement with angiographic observations.

Promising results were obtained relating posttreatment flow conditions and outcomes of treatments with intrasaccular devices, which need to be confirmed on larger series.
Recovering spectral reflectance based on natural neighbor interpolation with model‐based metameric spectra of extreme points
Authors: Chou Tzren‐Ru , Hsieh Chi‐Heng , Chen En
Published: March 2019

In this article, we proposed a new method based on natural neighbor interpolation to recover the spectral reflectance of objects from an image captured by a traditional Red‐Green‐Blue (RGB) digital camera. The concept of model‐based metameric spectra of eight extreme points in the standard RGB (sRGB) color gamut was further introduced to ensure that almost all test samples in the entire gamut can be simply and properly recovered without needing the extrapolation or any other auxiliary techniques. The quasi‐Newton method was used to estimate iteratively the optimal parameters of these metameric spectra, satisfying the constraints of the gamut extreme points. Several experiments were performed. The effectiveness of the method with and without the metameric spectra was evaluated, including some performance comparisons with the principal component analysis (PCA) method of transformational type (classic PCA and weighted PCA) and that of interpolation type. The results showed that the proposed method greatly enlarged the accurately applicable domain of the interpolation strategy and offered spectra with feasibility and naturalness much superior to the PCA‐based methods. The proposed method was obviously better than the conventional interpolation ones, and had a similar performance with the weighted PCA method in terms of color difference.