bluuebunny/crossref_metadata_2025 huggingface dataset:
Structure–Transport Correlation Reveals Anisotropic Charge Transport in Coupled PbS Nanocrystal Superlattices
Authors: Maier Andre , Lapkin Dmitry , Mukharamova Nastasia , Frech Philipp , Assalauova Dameli , Ignatenko Alexandr , Khubbutdinov Ruslan , Lazarev Sergey , Sprung Michael , Laible Florian , Löffler Ronny , Previdi Nicolas , Bräuer Annika , Günkel Thomas , Fleischer Monika , Schreiber Frank , Vartanyants Ivan A. , Scheele Marcus
Published: July 2020

The assembly of colloidal semiconductive nanocrystals into highly ordered superlattices predicts novel structure‐related properties by design. However, those structure–property relationships, such as charge transport depending on the structure or even directions of the superlattice, have remained unrevealed so far. Here, electric transport measurements and X‐ray nanodiffraction are performed on self‐assembled lead sulfide nanocrystal superlattices to investigate direction‐dependent charge carrier transport in microscopic domains of these materials. By angular X‐ray cross‐correlation analysis, the structure and orientation of individual superlattices is determined, which are directly correlated with the electronic properties of the same microdomains. By that, strong evidence for the effect of superlattice crystallinity on the electric conductivity is found. Further, anisotropic charge transport in highly ordered monocrystalline domains is revealed, which is attributed to the dominant effect of shortest interparticle distance. This implies that transport anisotropy should be a general feature of weakly coupled nanocrystal superlattices.
Diode‐Like Selective Enhancement of Carrier Transport through Metal–Semiconductor Interface Decorated by Monolayer Boron Nitride
Authors: Jaiswal Hemendra Nath , Liu Maomao , Shahi Simran , Wei Sichen , Lee Jihea , Chakravarty Anindita , Guo Yutong , Wang Ruiqiang , Lee Jung Mu , Chang Chaoran , Fu Yu , Dixit Ripudaman , Liu Xiaochi , Yang Cheng , Yao Fei , Li Huamin
Published: July 2020

2D semiconductors such as monolayer molybdenum disulfide (MoS2) are promising material candidates for next‐generation nanoelectronics. However, there are fundamental challenges related to their metal–semiconductor (MS) contacts, which limit the performance potential for practical device applications. In this work, 2D monolayer hexagonal boron nitride (h‐BN) is exploited as an ultrathin decorating layer to form a metal–insulator–semiconductor (MIS) contact, and an innovative device architecture is designed as a platform to reveal a novel diode‐like selective enhancement of the carrier transport through the MIS contact. The contact resistance is significantly reduced when the electrons are transported from the semiconductor to the metal, but is barely affected when the electrons are transported oppositely. A concept of carrier collection barrier is proposed to interpret this intriguing phenomenon as well as a negative Schottky barrier height obtained from temperature‐dependent measurements, and the critical role of the collection barrier at the drain end is shown for the overall transistor performance.
In Situ Plasma‐Grown Silicon‐Oxide for Polysilicon Passivating Contacts
Authors: Alzahrani Areej , Allen Thomas G. , De Bastiani Michele , Van Kerschaver Emmanuel , Harrison George T. , Liu Wenzhu , De Wolf Stefaan
Published: July 2020

Large‐scale manufacturing of polysilicon‐based passivating contacts for high‐efficiency crystalline silicon (c‐Si) solar cells demands simple fabrication of thermally stable SiOx films with well controlled microstructure and nanoscale thickness to enable quantum‐mechanical tunneling. Here, plasma‐dissociated CO2 is investigated to grow in situ thin (<2 nm) SiOx films on c‐Si wafers as tunnel‐oxides for plasma‐deposited, hole‐collecting (i.e., p‐type) polysilicon contacts. It is found that such plasma processing offers excellent thickness control and superior structural integrity upon thermal annealing at 1000 °C, compared to state‐of‐the‐art wet‐chemical oxides. As a result, p‐type polysilicon contacts are achieved on n‐type c‐Si wafers that combine excellent surface passivation, resulting in an implied open‐circuit voltage exceeding 700 mV, with a contact resistance as low as 0.02 Ω cm2.
Fabrication and Functionalization of 3D Printed Polydimethylsiloxane‐Based Microfluidic Devices Obtained through Digital Light Processing
Authors: Gonzalez Gustavo , Chiappone Annalisa , Dietliker Kurt , Pirri Candido Fabrizio , Roppolo Ignazio
Published: July 2020

This work reports the preparation and 3D printing of a custom‐made photopolymer based on acrylate‐polydimethylsiloxane (PDMS), for the fabrication of complex‐shaped 3D printed microfluidic chips. By selecting and combining the proper materials during the preparation of the resins along with the freedom of design of light‐based 3D printers, 3D microfluidic PDMS‐like chips are obtained with excellent optical features, high chemical stability, and good mechanical properties. Furthermore, taking advantage of unreacted functional groups exposed on the sample's surface after the 3D printing step, the surface properties of the devices are easily and selectively modified during the postcuring step through UV‐induced grafting polymerization techniques, giving an added value to the printed devices in terms of surface treatment compared to conventional methods. The 3D printing of the PDMS‐based resins developed here may potentially transforms the fabrication methodology of PDMS microfluidic devices by decreasing manufacturing costs and time, allowing the production of complex‐shaped and truly 3D microdevices.
Toward Higher Voltage Solid‐State Batteries by Metastability and Kinetic Stability Design
Authors: Ye Luhan , Fitzhugh William , Gil‐González Eva , Wang Yichao , Su Yibo , Su Haoqing , Qiao Tianyu , Ma Lu , Zhou Hua , Hu Enyuan , Li Xin
Published: July 2020

The energy density of battery systems is limited largely by the electrochemical window of the electrolyte. Herein, the combined thermodynamic and kinetic effects of mechanically induced metastability are shown to greatly widen the operational voltage window of solid‐state batteries based on ceramic‐sulfide electrolytes. Solid electrolyte voltage stability up to 10 V is achieved with minimal degradation, far beyond the capability of organic liquid electrolytes. Furthermore, combined experiment, ab initio computation, and theoretical modeling identify the nature of mechanically constrained Li10GeP2S12 decomposition both within the bulk and at interfaces with cathode materials at very high voltages. Previously unclear kinetic processes are identified that, when properly implemented, can potentially allow solid‐state full cells with remarkably high operational voltages.
A Fluorination Method for Improving Cation‐Disordered Rocksalt Cathode Performance
Authors: Ahn Juhyeon , Chen Dongchang , Chen Guoying
Published: July 2020

In Li‐rich cation‐disordered rocksalt oxide cathodes (DRX), partial fluorine substitution in the oxygen anion sublattice can increase the capacity contribution from transition‐metal (TM) redox while reducing that from the less reversible oxygen redox. To date, limited fluorination substitution has been achieved by introducing LiF precursor during the solid‐state synthesis. To take full advantage of the fluorination effect, however, a higher F content is desired. In the present study, the successful use of a fluorinated polymeric precursor is reported to increase the F solubility in DRX and the incorporation of F content up to 10–12.5 at% into the rocksalt lattice of a model Li‐Mn‐Nb‐O (LMNO) system, largely exceeding the 7.5 at% limit achieved with LiF synthesis. Higher F content in the fluorinated‐DRX (F‐DRX) significantly improves electrochemical performance, with a reversible discharge capacity of ≈255 mAh g−1 achieved at 10 at% of F substitution. After 30 cycles, up to a 40% increase in capacity retention is achieved through the fluorination. The study demonstrates the feasibility of using a new and effective fluorination process to synthesize advanced DRX cathode materials.
Analysis of Thoroughbred horse farm workers’ compensation insurance claims in Kentucky: Injury frequency, cost, lost time, and associated occupational factors
Authors: Flunker John C. , Clouser Jessica Miller , Swanberg Jennifer E.
Published: July 2020

Background

Thoroughbred horse farm workers self‐report a high frequency of work‐related injuries and pain. However, an analysis of Thoroughbred horse farm workers’ compensation injury claims is absent from the literature, yet may benefit worker safety.

Methods

We analyzed workers’ compensation insurance firm data containing 2276 claims filed between 2008 and 2015. Injury frequency, cost, and lost time per cause, nature, and body part injured were examined qualitatively and via univariate tests. Factors associated with high cost and high duration lost time claims were modeled via multivariable logistic regression.

Results

The average Thoroughbred worker claim cost $4,198 and accrued 10 days lost time, involving strikes (57% of total claims), sprains/strains (34%), and wrist/hand injuries (18%). Injuries primarily occurred on mornings (54%), weekdays (79%), and during the transition from breeding to sales (23%). Jobs with a high level of horse contact had significantly higher cost ($6,487) and higher duration lost time (16.8 days) claims, with significantly higher cost claims on the weekends ($6,471) and from the oldest workers ($7466), vs reference groups. Logistic models indicate significantly increased odds of a high‐cost injury among high horse contact jobs (OR = 1.87; 95% C.I. = 1.53‐2.29) and older age tertiles (1.38; 1.08‐1.75; 1.70, 1.32‐2.18). The odds of a high duration lost time injury are significantly increased among high horse contact jobs (1.91; 1.53‐2.39) and males (1.50, 1.13‐1.98), with significantly reduced odds among the most tenured workers (0.74; 0.56‐0.99).

Conclusions

Our findings elucidate factors to reduce injury frequency, cost, and lost time among Thoroughbred horse farm workers.
Stereoselective Seed‐Induced Living Supramolecular Polymerization
Authors: Sarkar Souvik , Sarkar Aritra , George Subi J.
Published: July 2020

Stereoselective and temporally controlled supramolecular polymerizations are ubiquitous in nature and are desirable attributes for the design of chiral, well‐defined functional materials. Kinetically controlled, living supramolecular polymerization (LSP) has emerged recently for the synthesis of supramolecular polymers with controlled length and narrow dispersity. On the other hand, stringent design requirements for chiral‐discriminating monomers precludes the stereoselective control of the supramolecular polymer structure. Herein, a synergetic stereo‐ and structural control of supramolecular polymerization by the realization of an unprecedented stereoselective seed‐induced LSP is reported. Homochiral and seeded growth is demonstrated with bischromophoric naphthalene diimide (NDI) enantiomers with a chiral binaphthyl amine core, exhibiting strong self‐recognition abilities and pathway complexity.
A Chiral‐Label‐Free SERS Strategy for the Synchronous Chiral Discrimination and Identification of Small Aromatic Molecules
Authors: Wang Yue , Zhao Xueqi , Yu Zhi , Xu Zhangrun , Zhao Bing , Ozaki Yukihiro
Published: July 2020

A versatile and robust chiral discrimination strategy for small aromatic compounds is of significant importance in multidisciplinary fields. However, most current methods lack either the sufficient sensitivity for recognizing the chirality of the target molecules or their molecular specificity information. We have developed a versatile and chiral‐label‐free surface‐enhanced Raman scattering (SERS)‐based chiral discrimination sensing system for small aromatic molecules, where the molecular structural specificity and enantioselectivity can be given synchronously in a single SERS spectrum. More than 10 types of chiral aromatic molecules were successfully identified by using this system. This work has enormous potential for recognizing chiral products effectively in sophisticated systems, especially in the fields of chiral synthesis and chiral catalysis.
Amplified FRET Nanoflares: An Endogenous mRNA‐Powered Nanomachine for Intracellular MicroRNA Imaging
Authors: Li Jing , Wang Jiaoli , Liu Shiyuan , Xie Nuli , Quan Ke , Yang Yanjing , Yang Xiaohai , Huang Jin , Wang Kemin
Published: July 2020

It is of great value to detect biological molecules in live cells. However, probes for imaging low‐abundance targets in live cells are limited by the one‐to‐one signal‐triggered model. Here, we introduce the concept of the amplified FRET nanoflare, which employs high‐abundance endogenous mRNA as fuel strands to amplify the detection of low abundance intracellular miRNA. As far as we know, this is the first report of an endogenous mRNA‐powered nanomachine for intracellular molecular detection. We experimentally prove the mechanism of the nanomachine and demonstrate its specificity and sensitivity. The proposed amplified FRET nanoflare can act as an excellent intracellular molecular detection strategy that is promising for biological and medical applications.
Construction of Organelle‐Like Architecture by Dynamic DNA Assembly in Living Cells
Authors: Guo Xiaocui , Li Feng , Liu Chunxia , Zhu Yi , Xiao Nannan , Gu Zi , Luo Dan , Jiang Jianhui , Yang Dayong
Published: July 2020

The design of controllable dynamic systems is vital for the construction of organelle‐like architectures in living cells, but has proven difficult due to the lack of control over defined topological transformation of self‐assembled structures. Herein, we report a DNA based dynamic assembly system that achieves lysosomal acidic microenvironment specifically inducing topological transformation from nanoparticles to organelle‐like hydrogel architecture in living cells. Designer DNA nanoparticles are constructed from double‐stranded DNA with cytosine‐rich stick ends (C‐monomer) and are internalized into cells through lysosomal pathway. The lysosomal acidic microenvironment can activate the assembly of DNA monomers, inducing transformation from nanoparticles to micro‐sized organelle‐like hydrogel which could further escape into cytoplasm. We show how the hydrogel regulates cellular behaviors: cytoskeleton is deformed, cell tentacles are significantly shortened, and cell migration is promoted.
Efficient Pd‐Catalyzed Direct Coupling of Aryl Chlorides with Alkyllithium Reagents
Authors: Scherpf Thorsten , Steinert Henning , Großjohann Angela , Dilchert Katharina , Tappen Jens , Rodstein Ilja , Gessner Viktoria H.
Published: July 2020

Organolithium compounds are amongst the most important organometallic reagents and frequently used in difficult metallation reactions. However, their direct use in the formation of C−C bonds is less established. Although remarkable advances in the coupling of aryllithium compounds have been achieved, Csp2−Csp3 coupling reactions are very limited. Herein, we report the first general protocol for the coupling or aryl chlorides with alkyllithium reagents. Palladium catalysts based on ylide‐substituted phosphines (YPhos) were found to be excellently suited for this transformation giving high selectivities at room temperature with a variety of aryl chlorides without the need for an additional transmetallation reagent. This is demonstrated in gram‐scale synthesis including building blocks for materials chemistry and pharmaceutical industry. Furthermore, the direct coupling of aryllithiums as well as Grignard reagents with aryl chlorides was also easily accomplished at room temperature.
Improving through‐thickness conductivity of carbon fiber reinforced polymer using carbon nanotube/polyethylenimine at the interlaminar region
Authors: Robert Colin , Thitasiri Witiwat Best , Mamalis Dimitrios , Hussein Zakareya Elmo , Waqas Muhammad , Ray Dipa , Radacsi Norbert , Koutsos Vasileios
Published: July 2020

The through‐thickness conductivity of carbon fiber reinforced polymer (CFRP) composite was increased by incorporating multiwalled carbon nanotubes in the interlaminar region. Carbon nanotubes (CNTs) were dispersed in a polyethylenimine (PEI) binder, which was then coated onto the carbon fiber fabric. Standard vacuum‐assisted resin infusion process was applied to fabricate the composite laminates. This modification technique aims to enhance the electrical conductivity in through‐thickness direction for the purpose of nondestructive testing, damage detection, and electromagnetic interference shielding. CNT concentrations ranging from 0 to 0.75 wt% were used and compared to pristine CFRP samples (reference). The through‐thickness conductivity of the CFRP exhibited an improvement of up to 781% by adopting this technique. However, the dispersion of CNT in PEI led to a viscosity increase and poor wetting properties which resulted in the formation of voids/defects, poor adhesion (as shown in scanning electron micrographs) and the deterioration of the mechanical properties as manifested by interlaminar shear strength and dynamic mechanical analysis measurements.
Tailored Silicon/Carbon Compounds for Printed Li–Ion Anodes
Authors: Sukkurji Parvathy Anitha , Issac Ibrahim , Singaraju Surya Abhishek , Velasco Leonardo , Aghassi Hagmann Jasmin , Bessler Wolfgang , Hahn Horst , Botros Miriam , Breitung Ben
Published: July 2020

Invited for this month's cover picture is the group and collaboration partners of Prof. Horst Hahn from the Institute of Nanotechnology (INT) at Karlsruhe Institute of Technology (KIT). The cover picture shows printed silicon anodes coated with carbon for powering of electrolyte‐gated transistors. Read the full text of the Article at 10.1002/batt.202000052.
Toward in silico CMC: An industrial collaborative approach to model‐based process development
Authors: Roush David , Asthagiri Dilip , Babi Deenesh K. , Benner Steve , Bilodeau Camille , Carta Giorgio , Ernst Philipp , Fedesco Mark , Fitzgibbon Sean , Flamm Matthew , Griesbach Jan , Grosskopf Tobias , Hansen Ernst B. , Hahn Tobias , Hunt Stephen , Insaidoo Francis , Lenhoff Abraham , Lin Jasper , Marke Henrik , Marques Bruno , Papadakis Emmanouil , Schlegel Fabrice , Staby Arne , Stenvang Marcel , Sun Larry , Tessier Peter M. , Todd Robert , von Lieres Eric , Welsh John , Willson Richard , Wang Gang , Wucherpfennig Thomas , Zavalov Oleksandr
Published: July 2020

The Third Modeling Workshop focusing on bioprocess modeling was held in Kenilworth, NJ in May 2019. A summary of these Workshop proceedings is captured in this manuscript. Modeling is an active area of research within the biotechnology community, and there is a critical need to assess the current state and opportunities for continued investment to realize the full potential of models, including resource and time savings. Beyond individual presentations and topics of novel interest, a substantial portion of the Workshop was devoted toward group discussions of current states and future directions in modeling fields. All scales of modeling, from biophysical models at the molecular level and up through large scale facility and plant modeling, were considered in these discussions and are summarized in the manuscript. Model life cycle management from model development to implementation and sustainment are also considered for different stages of clinical development and commercial production. The manuscript provides a comprehensive overview of bioprocess modeling while suggesting an ideal future state with standardized approaches aligned across the industry.
Game‐based activities targeting visual literacy skills to increase understanding of biomolecule structure and function concepts in undergraduate biochemistry
Authors: Terrell Cassidy R. , Nickodem Kyle , Bates Alison , Kersten Cassandra , Mernitz Heather
Published: July 2020

Introductory biochemistry courses are often challenging for students because they require the integration of chemistry, biology, physics, math, and physiology knowledge and frameworks to understand and apply a large body of knowledge. This can be complicated by students' persistent misconceptions of fundamental concepts and lack of fluency with the extensive visual and symbolic literacy used in biochemistry. Card sorting tasks and game‐based activities have been used to reveal insights into how students are assimilating, organizing, and structuring disciplinary knowledge, and how they are progressing along a continuum from disciplinary novice to expert. In this study, game‐based activities and card sorting tasks were used to promote and evaluate students' understanding of fundamental structure–function relationships in biochemistry. Our results suggest that while many markers of expertise increased for both the control and intervention groups over the course of the semester, students involved in the intervention activities tended to move further towards expert‐like sorting. This indicates that intentional visual literacy game‐based activities have the ability to build underdeveloped skills in undergraduate students.
A case of transient alien hand syndrome from a very small ischemic stroke
Authors: Liu Hsin‐Chen , Apramian Austin , Liu Antonio
Published: July 2020

Posterior alien hand syndrome caused by small infarcts seems to be characterized by acute development and transient, yet profound, isolated motor dysfunction with a favorable prognosis unlike other cases due to larger MCA infarcts.
Syntheses of Thailandepsin B Pseudo‐Natural Products: Access to New Highly Potent HDAC Inhibitors via Late‐Stage Modification
Authors: Brosowsky Jana , Lutterbeck Monika , Liebich Amelie , Keller Manfred , Herp Daniel , Vogelmann Anja , Jung Manfred , Breit Bernhard
Published: July 2020

New Thailandepsin B pseudo‐natural products have been prepared. Our synthetic strategy offers the possibility to introduce varying warheads via late stage modification. Additionally, it gives access to the asymmetric branched allylic ester moiety of the natural product in a highly diastereoselective manner applying rhodium‐catalyzed hydrooxycarbonylation. The newly developed pseudo‐natural products are extremely potent and selective HDAC inhibitors. The non‐proteinogenic amino acid d‐norleucine was obtained enantioselectively by a recently developed method of rhodium‐catalyzed hydroamination.
Photocatalytic CO2 Reductions Catalyzed by meso‐(1,10‐Phenanthrolin‐2‐yl)‐Porphyrins Having a Rhenium(I) Tricarbonyl Complex
Authors: Kuramochi Yusuke , Satake Akiharu
Published: July 2020

We have prepared Zn and free‐base porphyrins appended with a fac‐Re(phen)(CO)3Br (where phen is 1,10‐phenanthroline) at the meso position of the porphyrin, and performed photocatalytic CO2 reduction using porphyrin–Re dyads in the presence of either triethylamine (TEA) or 1,3‐dimethyl‐2‐phenyl‐2,3‐dihydro‐1H‐benzo[d]imidazole (BIH) as an electron donor. The Zn porphyrin dyad showed a high turnover number for CO production compared with the free‐base porphyrin dyad, suggesting that the central Zn ion of porphyrin plays an important role in suppressing electron accumulation on the porphyrin part and achieving high durability of the photocatalytic CO2 reduction using both TEA and BIH. The effect of acids on the CO2 reduction was investigated using the Zn porphyrin–Re dyad and BIH. Acetic acid, a relatively strong Brønsted acid, rapidly causes the porphyrin's color to fade upon irradiation and dramatically decreases CO production, whereas proper weak Brønsted acids such as 2,2,2‐trifluoroethanol and phenol enhance the CO2 reduction.
Understanding bitumen partial upgrading through process modelling and simulation
Authors: Gholami Rahman , Alvarez‐Majmutov Anton , Ali Mohamed , Chen Jinwen
Published: July 2020

Partial upgrading is an emerging direction in the processing of Canadian oil sands bitumen in response to the economic and environmental challenges in the oil sands industry. Partial upgrading aims to improve bitumen quality only to the level at which pipeline specifications are met without use of diluent. Given that partial upgrading technologies have not yet reached commercial deployment, there is a lack of technical data to assess the expected benefits in terms of energy input and greenhouse gas emissions reduction. In this study, we present an assessment of a partial upgrading scheme using detailed process simulation. We developed a conceptual process scheme considering visbreaking, solvent deasphalting, and naphtha hydrotreating as the core partial upgrading processes. Reactor models were assembled using experimental data from CanmetENERGY's pilot plant facilities and from the literature and integrated into a plant‐wide simulation model. Simulations allowed the examination of trends in partial upgrader product yields and quality and enabled a comparison with traditional bitumen upgrading.
Cell‐Penetrating Peptide‐Conjugated BF2‐Oxasmaragdyrins as NIRF Imaging and Photothermal Agents
Authors: Laxman Kandala , Reddy B. Pradeep K. , Robinson Andrea , Srivastava Rohit , Ravikanth Mangalampalli
Published: July 2020

Cell‐penetrating peptides (CPPs) are excellent cell internalizing agents for hydrophobic drug/dye moieties. We exploited this property of CPPs for the cell internalization of BF2‐oxasmaragdyrin by constructing covalent conjugates of BF2‐oxasmaragdyrin with CPPs (CRGDK and polyarginine (R9)) using a solid‐phase peptide synthesis (SPPS) methodology. The CPP‐conjugated BF2‐oxasmaragdyrins were purified by reversed‐phase HPLC and characterized by mass spectrometry. The CPP‐conjugated BF2‐oxasmaragdyrins were found to be photostable, absorb in the visible‐NIR region (400–700 nm), emit in the NIR−I region (∼715–720 nm) with moderate quantum yields, and be biocompatible, with excellent cellular imaging potential in breast cancer cells (MDA‐MB‐231). The R9 conjugate, being the first water‐soluble BF2‐oxasmaragdyrin, also possesses excellent photothermal transduction efficacy with 750 nm laser irradiation and is a potential theranostic agent.
From Heteroditopic to Multitopic Receptors for Ion‐Pair Recognition: Advances in Receptor Design and Applications
Authors: McConnell Anna J. , Docker Andrew , Beer Paul D.
Published: July 2020

Ion‐pair recognition has emerged from cation and anion recognition and become a diverse and active field in its own right. The last decade has seen significant advances in receptor design in terms of the types of binding motifs, understanding of cooperativity and increase in complexity from heteroditopic to multitopic receptors. As a result, attention has turned to applying this knowledge to the rational design of ion‐pair receptors for applications in salt solubilisation and extraction, membrane transport and sensing. This Review highlights recent progress and developments in the design and applications of heteroditopic and multitopic receptors for ion‐pair recognition.
Structural Variations in Complex Sodium Thorium Arsenates
Authors: Hao Yucheng , Alekseev Evgeny V. , Klepov Vladislav V. , Yu Na
Published: July 2020

Three new sodium thorium arsenates, Na5Th4(AsO4)7 (1), Na5Th(AsO4)3 (2), and Na4Th(As2O7)2 (3) were synthesized via a high temperature route and their structures and optical properties were studied. Compound 1 adopts a three‐dimensional structure that consists of tetrameric fundamental building blocks (FBBs) [Th4(AsO4)7]5–, which are constructed by ThO8 and ThO9 polyhedra. The structures of 2 and 3 are based on open frameworks with channels running along the a or c axes, respectively, which are occupied by Na cations. Structural relations between the structures of 2 and 3 have been discussed regarding their composition. In contrast to the other two compounds, the arsenate anions in the structure of 2 play role of bridging ligands and do not connect more than two Th atoms. Owing to this, the underlying net of this compound contains only Th nodes has a lon topology. The Raman spectra of 1 and 2 contain similar peaks due to As–O vibrations of AsO4 groups, while the Raman spectrum of 3 differs significantly owing to the presence of As–O–As bridging group in As2O74– anions.
Optimization of Single‐Molecule Magnets by Suppression of Quantum Tunneling of the Magnetization
Authors: Oldengott Jan Christian , Schnack Jürgen , Glaser Thorsten
Published: July 2020

The ligand system triplesalen was rationally designed following requirements for polynuclear 3d single‐molecule magnets (SMMs). The essential central part is the C3 symmetric, meta‐phenylene bridging unit phloroglucinol for ferromagnetic interactions via the spin‐polarization mechanism. The triplesalen‐based [MnIII6CrIII]3+ SMMs strongly suppress the quantum tunneling of the magnetization (QTM) but exhibit blocking temperatures not exceeding 2 K. We have analyzed the reason for this behavior and found that the triplesalen ligands are not in the anticipated aromatic phloroglucinol form but in a non‐aromatic heteroradialene form. Here we present our strategies to optimize the triplesalen ligand system to suppress the heteroradialene formation and to enforce ferromagnetic interactions. This allowed us to study in detail the influence of exchange coupling on the QTM and relaxation properties of SMMs and provides valuable insights for further rational improvements of our triplesalen ligand system and of SMMs in general.
Recent Developments in Transition Metal‐Free Cross‐Dehydrogenative Coupling Reactions for C–C Bond Formation
Authors: Batra Aanchal , Singh Kamal Nain
Published: July 2020

In recent years, carbon–carbon (C–C) bond formation, by directly connecting two different C–H bonds under oxidative conditions, has attracted much attention in academia and industries. Also known as Cross‐Dehydrogenative Coupling (CDC), this methodology is an eco‐friendly, cost and step economic as well as superior alternative to classical C–C coupling reactions. The catalytic functionalization of C–H bonds using transition metals is an interesting research topic and is extensively reported, but limited surveys are known for non‐metal catalysed processes. This review briefly describes on the recent developments in cross‐dehydrogenative coupling reactions for C–C bond formation with different oxidants under metal free conditions.
Asymmetric hetero‐Diels‐Alder Reaction of trans‐1‐Methoxy‐3‐trimethylsilyloxy‐buta‐1,3‐diene Catalyzed by Zinc Complexes
Authors: Stefaniak Matylda , Buda Szymon , Mlynarski Jacek
Published: July 2020

Asymmetric hetero‐Diels‐Alder reactions of Danishefsky's diene and glyoxylate/pyruvate esters catalyzed by readily available zinc triflate complex with BOX ligand afforded the corresponding adduct which upon treatment with trifluoroacetic acid furnished the hetero‐Diels‐Alder product in 91 % enantiomeric excess and 87 % isolated yield. This reaction was applied to the concise synthesis of six‐membered ulosonic acid C‐glycoside.
Improved STR analysis of degraded DNA from human skeletal remains through in‐house MPS‐STR panel
Authors: Cho Sohee , Shin Kyoung‐Jin , Bae Su‐Jin , Kwon Ye‐Lim , Lee Soong Deok
Published: July 2020

DNA analysis of degraded samples and low‐copy number DNA derived from skeletal remains, one of the most challenging forensic tasks, is common in disaster victim identification and genetic analysis of historical materials. Massively parallel sequencing (MPS) is a useful technique for STR analysis that enables the sequencing of smaller amplicons compared with conventional capillary electrophoresis (CE), which is valuable for the analysis of degraded DNA. In this study, 92 samples of human skeletal remains (70+ years postmortem) were tested using an in‐house MPS‐STR system designed for the analysis of degraded DNA. Multiple intrinsic factors of DNA from skeletal remains that affect STR typing were assessed. The recovery of STR alleles was influenced more by DNA input amount for amplification rather than DNA degradation, which may be attributed from the high quantity and quality of libraries prepared for MPS run. In addition, the higher success rate of STR typing was achieved using the MPS‐STR system compared with a commercial CE‐STR system by providing smaller sized fragments for amplification. The results can provide constructive information for the analysis of degraded sample, and this MPS‐STR system will contribute in forensic application with regard to skeletal remain sample investigation.
New Insights into the Degradation Behavior of Air Electrodes during Solid Oxide Electrolysis and Reversible Solid Oxide Cell Operation
Authors: Khan Muhammad Shirjeel , Xu Xiaoyong , Knibbe Ruth , Rehman Ateeq ur , Li Zhiheng , Yago Anya Josefa , Wang Hao , Zhu Zhonghua
Published: July 2020

The commercialization of reversible solid oxide cells (RSOCs) is limited by the severe degradation of the air electrodes during solid oxide electrolysis cells (SOECs) operation. Herein, the degradation behavior of (La0.8Sr0.2)0.95Mn1−xCoxO3−δ (LSMC) air electrodes where x = 0.1, 0.3, and 0.5 is reported. After the SOEC test, the air electrode with x = 0.1 delaminates. While previous studies reported delamination due to the disintegration of air electrodes, for the first time, it is shown that delamination can also occur due to the disintegration of the samaria‐doped ceria (SDC) barrier layer into nanoparticles. The formation of such nanoparticles weakens the contact between the air electrode and barrier layer and encourages delamination. The air electrode with x = 0.3, shows excellent long‐term stability and also produces an electrolysis current density of 0.63 A cm−2 in 50% H2O/50% H2 at 1.3 V. This mechanistic study will allow researchers to develop air electrodes with improved long‐term stability.
Zinc based micro‐electrochemical energy storage devices: Present status and future perspective
Authors: Wang Xiao , Wu Zhong‐Shuai
Published: July 2020

In order to keep rapid pace with increasing demand of wearable and miniature electronics, zinc‐based microelectrochemical energy storage devices (MESDs), as a promising candidate, have gained increasing attention attributed to low cost, environmental benign, and high performance. Herein, this review summarizes the state‐of‐the‐art advances of zinc‐based MESDs in microbatteries (MBs) and microsupercapacitors and highlights merits of cost effectiveness and high performance for miniaturized smart integrated systems. First, an introduction is given to present importance of zinc‐based MESDs. Second, current status with representative fiber, in‐plane and sandwiched configurations are illustrated in detail, particularly with a focus on the reasonable construction of multifunctional MBs and microsupercapacitors and deep understanding of energy storage mechanisms. Then, achievements for smart systems are overviewed to highlight environmental adaptability, integratable properties, and scalability in targeting applications. Finally, critical perspectives and challenges on the synergistic optimization of whole device are discussed to demonstrate forward‐looking developmental directions of zinc‐based MESDs.

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Numerical investigation of thermal performance of extended surfaces for a novel heat exchanger
Authors: Tokas Sulekh , Krishnayatra Gaurav , Zunaid Mohammad
Published: July 2020

The present paper provides a thorough numerical study of variation in geometrical parameters that affect the performance of the novel finned‐tube type heat exchanger design. The finite volume method was employed to discretize and solve the governing partial differential equations of heat conduction. A wide range of constant convective heat transfer coefficient (5 < h < 200 W/m2 K) is chosen to reduce the computational time and power, which covers thermal applications of latent thermal energy storage, refrigeration & air‐conditioning, etc. The effects of the ratio of fin spacing of fins to the outer diameter of the tube (0.1 ≤ δ* ≤ 8), the material of fins (copper and stainless steel) and the ratio of fin thickness to the outer diameter of the tube (0.0333 ≤ t* ≤ 0.4) on the performance parameters namely efficiency (η) and effectiveness (ε) of the fins were studied. Temperature contours for a wide range of geometries were depicted. The maximum effectiveness of copper fins is 304.62, whereas that for steel fin is 219.33 with the optimum dimensionless fin thickness reported to be t* = 0.1666. Furthermore, the maximum overall efficiencies of fins were 99.98% and 99.62% for copper and steel fins, respectively.
SARS‐CoV‐2 infection associated acute kidney injury in patients with pre‐existing chronic renal disease: A report of two cases
Authors: Wang Yiru , Lv Yongman , Liu Qingquan
Published: July 2020

Background

The 2019 novel coronavirus (severe acute respiratory syndrome coronavirus 2 [SARS‐CoV‐2]) is driving a novel atypical pneumonia (coronavirus disease 2019 [COVID‐19]) outbreak in Wuhan, causing huge public health challenges both in China and globally. Limited data are available for information and prognosis on COVID‐19 patients with pre‐existing chronic kidney disease.

Case presentation

Here we described the clinical characteristics and outcomes from two patients—a female aged 40‐year‐old and an 83‐year‐old male—who were subjected to SARS‐CoV‐2 infection, with history of chronic renal insufficiency. The female was admitted for dry cough and shortness of breath and the male was admitted for fever. The thorax computed tomography revealed patchy consolidation and ground‐glass opacity in both scattered lobes and the throat swab sample for coronavirus nucleic acid was positive. They were diagnosed with COVID‐19 and their renal function became progressively worse after infection with COVID‐19. After symptomatic support treatment, in both the patients, renal function was obviously restored, and both recovered from this pneumonia and conformed to the discharge criteria.

Conclusion

SARS‐CoV‐2 infection may aggravate renal function impairment. It is crucial to monitor changes of renal function in patients with COVID‐19, especially those with primary kidney disease. Kidney protection interventions should be taken as early as possible, thereby improving the prognosis of patients with COVID‐19.
Are bank risk disclosures informative? Evidence from debt markets
Authors: Elamer Ahmed A. , Ntim Collins G. , Abdou Hussein A. , Owusu Andrews , Elmagrhi Mohamed , Ibrahim Awad Elsayed Awad
Published: July 2020

This study examines whether financial reporting with a specific focus on risk disclosures have a predictive (informative) effect on banks' credit ratings (BCRs) and, consequently, ascertains whether governance structures can moderate such an association. Using one of the largest bank‐level datasets collected from 12 Middle East and North African (MENA) countries over the 2006–2013 period to‐date, our findings are as follows. First, we find that risk disclosures have a predictive effect on BCRs. Second, we find that the relationship between risk disclosures and BCRs is contingent on the quality of governance structures. Specifically, we find that the informativeness of risk disclosures on BCRs is higher in banks with larger board size, greater independence, higher government ownership, and better Shariah supervisory board, but lower in banks with greater block ownership, higher foreign ownership and the presence of CEO duality. The central tenor of our findings remains unchanged after controlling for a number of firm‐ and country‐level factors, alternative risk disclosure measures, firm‐ and national‐level governance proxies, different types of banks, and potential endogeneities. The findings have important implications for investors, especially bondholders, standard‐setters, regulators, and central governments.
Toxicological safety evaluation of pasteurized Akkermansia muciniphila
Authors: Druart Céline , Plovier Hubert , Van Hul Matthias , Brient Alizée , Phipps Kirt R. , de Vos Willem M. , Cani Patrice D.
Published: July 2020

Gut microorganisms are vital for many aspects of human health, and the commensal bacterium Akkermansia muciniphila has repeatedly been identified as a key component of intestinal microbiota. Reductions in A. muciniphila abundance are associated with increased prevalence of metabolic disorders such as obesity and type 2 diabetes. It was recently discovered that administration of A. muciniphila has beneficial effects and that these are not diminished, but rather enhanced after pasteurization. Pasteurized A. muciniphila is proposed for use as a food ingredient, and was therefore subjected to a nonclinical safety assessment, comprising genotoxicity assays (bacterial reverse mutation and in vitro mammalian cell micronucleus tests) and a 90‐day toxicity study. For the latter, Han Wistar rats were administered with the vehicle or pasteurized A. muciniphila at doses of 75, 375 or 1500 mg/kg body weight/day (equivalent to 4.8 × 109, 2.4 × 1010, or 9.6 × 1010 A. muciniphila cells/kg body weight/day) by oral gavage for 90 consecutive days. The study assessed potential effects on clinical observations (including detailed arena observations and a modified Irwin test), body weight, food and water consumption, clinical pathology, organ weights, and macroscopic and microscopic pathology. The results of both in vitro genotoxicity studies were negative. No test item‐related adverse effects were observed in the 90‐day study; therefore, 1500 mg/kg body weight/day (the highest dose tested, equivalent to 9.6 × 1010 A. muciniphila cells/kg body weight/day) was established as the no‐observed‐adverse‐effect‐level. These results support that pasteurized A. muciniphila is safe for use as a food ingredient.
Methods matter: A review of Scientific Method: How Science Works, Fails to Work, and Pretends to Work by John Staddon, Routledge Press, 2018
Authors: Newland M. Christopher
Published: July 2020

The short and engaging book, How Science Works by John Staddon, reviews ways in which social and behavioral sciences arrive at decisions and how those decisions can best influence public policy. It is a provocative book that takes on controversial topics, including a critique of null hypothesis statistical testing, classical economic theories of supply and demand, limitations of Prospect Theory and behavioral economics, and evidence behind the health effects of smoking. A key theme running throughout is the idea that the theories and quantitative models used in the social sciences capture behavior and attitudes as fixed in time and fail to address the important issue of how behavior arose and how pliable it might be. The book will be of interest to scientists of all types as well as advanced students of psychology and other behavioral scientists.
Unraveling exhaustion in adaptive and conventional NK cells
Authors: Merino Aimee M , Kim Hansol , Miller Jeffrey S , Cichocki Frank
Published: July 2020

Immune exhaustion in T cells significantly impacts their ability to control malignancies and infections, and its discovery has led to revolutionary therapies for cancer in the form of checkpoint blockade. NK cells, like T cells, are lymphocytes that recognize virally infected and malignantly transformed cells. However, it remains unclear if NK cells are similarly susceptible to exhaustion. In this review, the aims are to summarize what is currently known and to identify key areas of variability that skew the scientific literature on NK cell exhaustion. A lack of consensus on the defining features of NK cell dysfunctional states such as senescence, suppression, and exhaustion has made a comparison between studies difficult. There are also significant differences in the biology of NK cell subsets with long-lived, adaptive NK cells sharing an epigenetic signature closer to memory CD8+ T cells than to conventional NK cells. Very different checkpoint receptor expression and effector functions have been shown in adaptive versus conventional NK cells chronically exposed to activating signals. Adaptive NK cells develop in individuals with cytomegalovirus (CMV) infection and well over half of the human population worldwide is CMV seropositive by adulthood. Despite this high prevalence, most studies do not account or control for this population. This may contribute to some of the variability reported in the literature on checkpoint receptor expression on NK cells. In this review, the protective role that exhaustion plays in T cells will also be discussed and the evidence for a similar phenomenon in NK cells will be examined.
Leader‐to‐Follower Transitions: Flexibility and Awareness
Authors: Falls Anthony , Allen Stuart
Published: July 2020

Middle managers can be both leaders and followers by virtue of their placement in the organizational hierarchy. Their position requires that they be adept at both leading and following and transitioning between the two roles. Such transitions may even occur multiple times within a single interaction with followers, peers, or top management. Ten randomly selected community college deans in the United States, representing academic middle management, were interviewed about how they differentiate between follower and leader roles, embrace a follower self‐concept, perceive their effectiveness in transitioning between follower and leader roles, and engage in the process of transitioning between roles. Findings suggested that awareness of the need to transition and the flexibility to transition were important to effectiveness as an academic middle manager. The participants seemed reluctant to embrace a follower self‐concept and primarily identified themselves as leaders. Leadership development and coaching for middle managers may benefit from increasing awareness of the need to transition between leader and follower roles to prepare middle managers for such a challenge.
Validation of a rapid ultra‐high‐performance liquid chromatography–tandem mass spectrometry method for quantification of chlorogenic acids in roasted coffee
Authors: Colomban Silvia , Guercia Elena , Navarini Luciano
Published: July 2020

Chlorogenic acids (CGAs) are a large class of esters formed between quinic acid and hydroxycinnamic acids. They are present in coffee as a complex mixture of positional and geometric isomers, where caffeoylquinic acids (CQAs) are the most abundant, followed by dicaffeoylquinic acids (diCQAs), feruloylquinic acids (FQAs), and p‐coumaroylquinic acids (p‐CoQAs). The aim of this work is to develop a new reliable and fast liquid chromatography–tandem mass spectrometry (LC–MS/MS) method for simultaneous identification and quantification of total amount of 11 CGAs in roasted coffee. Regarding sample preparation step, aqueous methanol and 100% aqueous ultrasonic extractions were evaluated. For the filtration Step 4, different membranes were tested, in order to fill the void of complete evaluation of extractables recovery when using different membranes, highlighting an incomplete recovery when using nylon filters. An LC/electrospray ionization (ESI)–MS/MS method was developed and validated following the European rules in terms of specificity, linearity, concentration range, limit of detection (LOD) and limit of quantification (LOQ), precision, and trueness, in order to obtain a useful quality control tool for roasted coffee. The method was applied for quantification of CGAs of a roasted coffee sample previously characterized by an interlaboratory circuit (LVU), and results were compared with the quantitation of CGAs via UHPLC‐DAD. The quantitative results were expressed as 5‐CQA equivalents, and the validation of this approach opens the way to reliable, cheap, and environmental‐friendly tools for quality control purposes.