bluuebunny/crossref_metadata_2025 huggingface dataset:
Additive Manufacturing of Electronics from Silver Nanopowders Sintered on 3D Printed Low‐Temperature Substrates.
Authors: Wałpuski Bartłomiej , Słoma Marcin
Published: January 2021

Additive manufacturing is more widely used these days in aerospace, power industry, and automotive. The latest reports indicate that electronics can be produced with this technique. This approach requires the development of new materials for the fabrication of conductive metallic layers on polymers. Herein, a hybrid technique based on fused deposition modeling, direct‐write, and selective laser sintering is demonstrated, for the fabrication of structural electronics. Highly conductive paths are obtained with conductivity values up to 3.2·106 S m−1 in a single printing and sintering additive process. The influence of process parameters is evaluated with several 3D printed polymer substrates affecting the electrical conductivity of the printed conductive paths and circuits. The developed hybrid technique allows performing selective thermal sintering of metallic pastes on polymer substrates exhibiting the value of melting temperatures much lower than the sintering temperature of the silver paste. This phenomenon can be explained with the proposed hypothesis that the activation energy of the sintering process of metallic paste and degradation of polymer substrate plays a key role in obtaining functional conductive metallic paths on polymer substrates. Application of the developed process is demonstrated with a simple human interface device and a circuit with light‐emitting diodes and power source.
Interfacial Engineering of Room Temperature Liquid Metals
Authors: Fu Jun‐Heng , Liu Tian‐Ying , Cui Yuntao , Liu Jing
Published: January 2021

Room temperature liquid metals (RTLMs), especially those made of gallium‐based alloys belong to an emerging versatile material with fascinating characteristics derived from its simultaneous metallic and inherent fluidic natures. The interfacial effects of liquid metal involved in diverse surfaces thus play critical roles in explaining many fundamental phenomena. Clarifying and engineering surface structure and physical/chemical properties of RTLMs under specific substrates leads to various unconventional chemical synthesis applications, energy conversion, soft machine, and printed electronics. Systematic interpretation of such interfacial issues either stabilized or dynamic is essential for constructing a holistic framework about the RTLMs interfacial engineering in developing advanced technologies. This article is dedicated to presenting a comprehensive overview of the interfacial effect of RTLMs in diverse environments and engineering strategies thus established. The basic characteristics of the interfacial effects between RTLMs, especially gallium‐based alloys and different surrounding mediums such as solid, liquid, or gas ambient are systematically illustrated. Typical applications thus enabled are introduced and discussed. Furthermore, future prospects of RTLMs interfacial engineering are forecasted.
Theoretical Analysis and Numerical Simulation for Cavity Ring‐Down Spectroscopy
Authors: Yang Qiansuo
Published: January 2021

To investigate the process of the creation of the ring‐down events in cavity ring‐down spectroscopy, theoretical formulae are derived for the interaction of the field in a cavity with the injection light, and a corresponding program for numerical simulation is developed. Using these theoretical formulas, the effects of the frequency detuning between the injection and the cavity mode, the absorption of the medium in the cavity, the residual injection, and the oscillation of the high‐order transverse modes are analyzed. A specific method for improving the measurement of the ring‐down time is proposed. With numerical simulation, the phenomenon of the intensity modulation during the frequency coupling of the cavity mode with the injection light is investigated. As the coherence of the injection light degrades, the light distribution in the cavity gradually develops from a smooth state to random states. Finally, it converges to a state at which the injection light is incoherent. The simple experimental results confirm that the limited coherence of the injection light causes the randomness of the development of the cavity field, and the results are used for the demonstration of the effectiveness and accuracy of the proposed method in solving for the ring‐down time.
High‐Level Production of Phenylacetaldehyde using Fusion‐Tagged Styrene Oxide Isomerase
Authors: Choo Joel P. S. , Kammerer Richard A. , Li Xiaodan , Li Zhi
Published: January 2021

An order‐of‐magnitude improvement in the production of phenylacetaldehyde to 3.37 M (405 g L−1) from the enzymatic isomerisation of styrene oxide was achieved. A small ubiquitin‐related modifier (SUMO) tag increases the productivity of the whole‐cell biocatalytic system by enhancing the expression of active membrane‐bound styrene oxide isomerase (SOI) while retaining enzyme catalytic efficiency and broad natural substrate scope. The isomerisation was performed by using Escherichia coli expressing SUMO‐tagged SOI in an organic‐aqueous biphasic system to yield 96% of phenylacetaldehyde.

magnified image
Cryptographic Key Generation and In Situ Encryption in One‐Transistor‐One‐Resistor Memristors for Hardware Security
Authors: Yang Ling , Cheng Long , Li Yi , Li Haoyang , Li Jiancong , Chang Ting‐Chang , Miao Xiangshui
Published: January 2021

The problem of hardware security is exacerbating in the artificial intelligence & Internet of Things era. Physical unclonable function (PUF) is a promising security primitive that exploits the intrinsic random variations in electronic hardware to produce digital keys. Here, it is shown for the first time that the subthreshold slope (S.S) variations of the transistors can be utilized as the entropy source of the PUF to generate the physical keys. By combining this S.S PUF with a memristor‐based XOR logic function, an in situ encryption/decryption scheme is proposed in a compact one‐transistor‐one‐resistor (1T1R) architecture. It is experimentally demonstrated that the S.S PUF shows great reproducibility, uniqueness, and uniformity. Using the S.S PUF keys, encryption and decryption are successfully implemented for three 16‐bit binary sequences in 1T1R devices. The results demonstrate that the unique features of 1T1R can enlighten functional design at the device level against hardware security threats, and the security, memory, and computing can be realized on the same device.
Robust distributed economic model predictive control based on differential dissipativity
Authors: Xiao Guannan , Yan Yitao , Bao Jie , Liu Fei
Published: January 2021

In this article, a robust distributed economic model predictive control (DEMPC) approach is developed for plant‐wide chemical processes. The proposed approach achieves arbitrary feasible setpoints that may vary frequently, attenuates the plant‐wide effects of unknown disturbances and minimizes a plant‐wide economic cost. In this approach, a plant‐wide process is represented as a network of process units and each process unit is controlled by an individual controller which shares a plant‐wide optimization economic objective and stability conditions through the network. To ensure the convergence of process variables to arbitrary setpoints, a contraction condition is developed for the DEMPC, based on the contraction theory. To deal with the effects of interactions among process units, the concept of dissipativity is adopted. Using sum‐separable control contraction metrics, a reference‐independent robust stability condition is developed to ensure the plant‐wide disturbance effects (under interactions among process units) to be attenuated in terms of differential ℒ2 gain and represented by a plant‐wide differential dissipativity condition, which is converted into the differential dissipativity conditions that individual controllers need to satisfy. This approach facilitates the optimization of plant‐wide economic costs with global constraints in a distributed way, allowing efficient implementation of alternating direction method of multipliers (ADMM). The proposed approach is illustrated using a reactor‐separator process.
Soft Touch using Soft Pneumatic Actuator–Skin as a Wearable Haptic Feedback Device
Authors: Sonar Harshal Arun , Huang Jian-Lin , Paik Jamie
Published: January 2021

Understanding the external environment depends heavily on vision, audition, and touch. Like vision and audition, the human sense of touch is complex. Tactile perception is composed of multiple fundamental and physical experiences felt as changes in stiffness, texture, shape, size, temperature, and weight by the skin. While researchers and industries have made continuous efforts to abstract and recreate these haptic experiences, haptic devices are still limited in invoking intricate and rich sensations. Herein, the design, model, and experimental validation of a wearable skin‐like interface, able to recreate the roughness, shape, and size of a perceived object is presented; a platform for an interactive “physical” experience. The cogency of immersion through tactile feedback on moldable clay by the user response from the active haptic feedback, is examined. For the experimental test, a soft pneumatic actuator (SPA)‐skin interface (90 Hz bandwidth) with a complex actuation pattern is prototyped. The SPA‐skin's performance using three sets of simulated textures (<300 μm) and for reconstructing simulated contours (of a rectangle, circle, or trapezoid) in the virtual reality (VR) platform is investigated. The experimental results demonstrated for the first time how artificially created tactile feedback can indeed simulate physical interaction, with 83% average accuracy for contour reconstruction.
The Encoding of Light‐Driven Micro/Nanorobots: from Single to Swarming Systems
Authors: Wang Jizhuang , Xiong Ze , Tang Jinyao
Published: January 2021

Light‐driven micro/nanorobot (LMNR), as an artificial micro/nanomachine, manifests excellent controllability, and appealing applications. The development of light‐manipulation strategies significantly advance both single and swarming LMNR systems, improving their capability for sophisticated tasks. In this review, the existing manipulation strategies for LMNRs, which are categorized according to encoding methods of light signals, is summarized. On top of it, the swarming systems are overviewed by considering the field in charge. The emerging applications and major challenges of LMNRs are then presented and discussed, which may lend insight to researchers to develop bespoke LMNR systems for target applications.
Evolution and biogeographic history of the Saguinus mystax group (Primates, Callithrichidae)
Authors: Athaydes Daysa , Dias Cayo A. R. , Gregorin Renato , Perini Fernando A.
Published: January 2021

The Saguinus mystax group traditionally includes three species, S. mystax, S. labiatus, and S. imperator. The additional inclusion of S. inustus is argued on molecular grounds, which have an important impact on our comprehension of the phenotypical evolution and biogeography of the group. Here, we investigate the evolutionary events leading to the diversification of the S. mystax group, integrating phylogenetic, temporal, and geographic information with the current knowledge of the Amazonian paleogeographical history. The examination of 208 specimens of Saguinus resulted in 25 morphological characters, of which 13 were used for the first time in a phylogenetic analysis of the genus. Morphological characters were also combined with molecular data and analyzed using Bayesian and Maximum Likelihood methods. Trees resulting from morphological and combined data recovered a monophyletic S. mystax group, including S. inustus, whose inclusion was supported by two morphological synapomorphies. Molecular based age estimates place the origin of Saguinus in the middle Miocene (17.4–13 million years ago [mya]), whereas the S. mystax group originated in an interval between 12 and 6 mya. Our results also suggest that the ancestral area of Saguinus was western Amazon, from where they dispersed to their current distribution after the end of the Pebas lakes system. The diversification events in the S. mystax group are related to the Pliocene development of the modern Amazon river network associated to the uplift of Fitzcarrald Arch.
Brain structures and networks responsible for stimulation‐induced memory flashbacks during forniceal deep brain stimulation for Alzheimer's disease
Authors: Germann Jürgen , Elias Gavin J.B. , Boutet Alexandre , Narang Keshav , Neudorfer Clemens , Horn Andreas , Loh Aaron , Deeb Wissam , Salvato Bryan , Almeida Leonardo , Foote Kelly D. , Rosenberg Paul B. , Tang‐Wai David F. , Wolk David A. , Burke Anna D. , Salloway Stephen , Sabbagh Marwan N. , Chakravarty M. Mallar , Smith Gwenn S. , Lyketsos Constantine G. , Okun Michael S. , Lozano Andres M.
Published: January 2021

Introduction

Fornix deep brain stimulation (fx‐DBS) is under investigation for treatment of Alzheimer's disease (AD). We investigated the anatomic correlates of flashback phenomena that were reported previously during acute diencephalic stimulation.

Methods

Thirty‐nine patients with mild AD who took part in a prior fx‐DBS trial (NCT01608061) were studied. After localizing patients’ implanted electrodes and modeling the volume of tissue activated (VTA) by DBS during systematic stimulation testing, we performed (1) voxel‐wise VTA mapping to identify flashback‐associated zones; (2) machine learning–based prediction of flashback occurrence given VTA overlap with specific structures; (3) normative functional connectomics to define flashback‐associated brain‐wide networks.

Results

A distinct diencephalic region was associated with greater flashback likelihood. Fornix, bed nucleus of stria terminalis, and anterior commissure involvement predicted memory events with 72% accuracy. Flashback‐inducing stimulation exhibited greater functional connectivity to a network of memory‐evoking and autobiographical memory‐related sites.

Discussion

These results clarify the neuroanatomical substrates of stimulation‐evoked flashbacks.
Tetraimidoschwefelsäure H2S(NtBu)4– isovalenzelektronisch zu H2SO4
Authors: Jung Jochen , Münch Annika , Herbst‐Irmer Regine , Stalke Dietmar
Published: January 2021

Das zur Schwefelsäure H2SO4isovalenzelektronische Imido‐Analogon H2S(NtBu)4wurde synthetisiert, isoliert und mittels NMR‐Spektroskopie sowie hochaufgelöster Röntgenstrukturanalyse und Ladungsdichteuntersuchungen charakterisiert. Letzteres zeigt stark polarisierte Sδ+‐Nδ−‐Bindungen mit praktisch keinem Doppelbindungscharakter. Die leicht zu polarisierenden S‐N‐Bindungen sind eine vorteilhafte und vielseitige Eigenschaft der Schwefel‐Stickstoff‐Liganden, mit der sie sich unterschiedlichen elektronischen Anforderungen verschiedener Metallkationen anpassen können.
Intensiv farbige Bor‐dotierte Thiazolthiazole durch reduktive Dimerisierung von Borisothiocyanaten
Authors: Hagspiel Stephan , Arrowsmith Merle , Fantuzzi Felipe , Vargas Alfredo , Rempel Anna , Hermann Alexander , Brückner Tobias , Braunschweig Holger
Published: January 2021

Die Reduktion von (CAAC)BBr2(NCS) (CAAC=cyclisches Alkyl(amino)carben) in der Gegenwart einer Lewis‐Base L liefert dreifach koordinierte (CAAC)LB(NCS)‐Borylene, die eine reversible (E)/(Z)‐Isomerisierung eingehen. Die gleiche Reduktion in Abwesenheit von L führt zu intensiv blauen, bis(CAAC)‐stabilisierten, Bor‐dotierten, aromatischen Thiazolthiazolen, die aus der Dimerisierung zweifach koordinierter (CAAC)B(NCS)‐Borylenintermediate resultieren.
Responsive Emulsions for Sequential Multienzyme Cascades
Authors: Sun Zhiyong , Zhao Qingcai , Haag Rainer , Wu Changzhu
Published: January 2021

Multienzyme cascade biocatalysis is an efficient synthetic process, avoiding the isolation/purification of intermediates and shifting the reaction equilibrium to the product side.. However, multienzyme systems are often limited by their incompatibility and cross‐reactivity. Herein, we report a multi‐responsive emulsion to proceed multienzyme reactions sequentially for high reactivity. The emulsion is achieved using a CO2, pH, and thermo‐responsive block copolymer as a stabilizer, allowing the on‐demand control of emulsion morphology and phase composition. Applying this system to a three‐step cascade reaction enables the individual optimal condition for each enzyme, and a high overall conversion (ca. 97 % of the calculated limit) is thereby obtained. Moreover, the multi‐responsiveness of the emulsion allows the facile and separate yielding/recycling of products, polymers and active enzymes. Besides, the system could be scaled up with a good yield.
Controlling the Stacking Modes of Metal–Organic Framework Nanosheets through Host–Guest Noncovalent Interactions
Authors: Tang Wen‐Qi , Zhao Ying‐Jie , Xu Ming , Xu Jin‐Ya , Meng Sha‐Sha , Yin Yun‐Dong , Zhang Qing‐Hua , Gu Lin , Liu Da‐Huan , Gu Zhi‐Yuan
Published: January 2021

The tuning of metal–organic framework (MOF) nanosheet stacking modes from molecular level was rarely explored although it significantly affected the properties and applications of nanosheets. Here, the different stacking modes of Zr‐1, 3, 5‐(4‐carboxylphenyl)‐benzene framework nanosheets were synthesized through the induction of different host–guest noncovalent interactions. The solvents of methyl benzene and ethyl acetate induced twisted stacking of nanosheets with the specific rotation angles of 12°, 18°, 24° and 6°, 18°, 24°, 30°, respectively, which was in agreement with theoretical calculations. Meanwhile, the alkanes were likely to vertically enter the pores of Zr‐BTB nanosheets because of steric hindrance and hydrophobic interactions, resulting in the untwisted stacking of nanosheets. The untwisted ordered nanopores showed the excellent gas chromatographic separations of benzene derivative isomers, which was better than twisted nanosheets stacking and commercial columns. This work uncovers a rational strategy to control the stacking of two‐dimensional MOF nanosheets.
Silver‐Catalysed Hydroarylation of Highly Substituted Styrenes
Authors: Dalton Toryn , Greßies Steffen , Das Mowpriya , Niehues Maximilian , Schrader Malte L. , Gutheil Christian , Ravoo Bart Jan , Glorius Frank
Published: January 2021

Hydroarylation is an effective strategy to rapidly increase the complexity of organic structures by transforming flat alkene moieties into three‐dimensional frameworks. Many strategies have already been developed to achieve the hydroarylation of styrenes, however most of these reports examine the hydroarylation of unpolar, β‐mono‐ or β‐unsubstituted styrenes, while exploring mainly electron‐rich benzene nucleophiles. Herein, we report a mild and general catalytic system for the selective hydroheteroarylation of multiply substituted styrenes and heteroaromatic styrenes. Mechanistic analysis of the reaction led to the discovery of commercially available 2,2′:5′,2′′‐terthiophene as a key reagent.
Phenyl‐bonded monolithic silica capillary column liquid chromatographic separation and detection of fluorogenic derivatized intact proteins
Authors: Kobayashi Hiroshi , Wada Hiroo , Imai Kazuhiro
Published: January 2021

Prior to the identification of proteins for proteomics analysis in human cells, separation of fluorogenic derivatized proteins with a fluorogenic reagent, 7‐chloro‐N‐[2‐(dimethylamino)ethyl]‐2,1,3‐benzoxadiazole‐4‐sulfonamide, has typically been performed by using a conventional reversed‐phase HPLC column. However, the number of proteins in human cells (HepaRG) that are separated by this conventional approach is limited to approximately 500. In this study, a nanoflow liquid chromatography system with an evaluated phenyl‐bonded monolithic silica capillary column (0.1 mm i.d., 700 mm length) was used to increase the number of separated fluorogenic derivatized proteins. This system was used to separate derivatized human cell proteins (K562) and yeast (Saccharomyces cerevisiae) proteins as model cell proteomes. More than 1,300 protein peaks were separated/detected from both cell proteomes. We present a straightforward comparison of multiple separation profiles using a novel chromatogram display approach, termed the “spiderweb” chromatogram. In addition, to validate that the detected peaks are derived from proteins, a mass spectrometer was connected to the capillary column and deconvolution of the obtained mass spectra was performed. Furthermore, different molecular weight distribution profiles of the expressed proteins were observed between the two cell proteomes.
The social identity perspective of social media leadership in collective action participation
Authors: Uysal Mete S. , Akfırat Serap A. , Cakal Huseyin
Published: January 2021

This study examines the Gezi Park protests in Turkey by corroborating the idea that the process of social identity leadership through social media contributes to the formation of protestor identity, which, in turn, allows people to participate in collective action. Specifically, we argued that evaluations of social media posts in terms of the three dimensions of the Identity‐Leadership Model (ILM)—identity prototypicality, advancement and the entrepreneurship of leaders, play a crucial role in collective action participation via identification with newly shaped protestor group. To address this argument, a retrospective survey study was conducted with a sample of 403 Turkish citizens who participated in the Gezi Park protests. Analyses showed that the three dimensions of ILM predicted the identification with the emergent protestor group. Furthermore, people's evaluations of social media users regarding group prototypicality, identity advancement and the entrepreneurship dimensions, based on their social media posts predicted participation in the Gezi Park protests following the calls of different types of social media accounts (personal, anonymous and institutional). In addition to this, identification with the protestor group significantly mediated the relationships between evaluations on social media accounts' leadership features between participation in collective action. We believe that our findings show that social identity leadership through social media contributes to the formation of a protestor group and identity which in turn, helps explain participation in collective action.
Filling the Charge–Discharge Voltage Gap in Flexible Hybrid Zinc‐Based Batteries by Utilizing a Pseudocapacitive Material
Authors: Wang Ling , Wang Xiao‐Tong , Zhong Jia‐Huan , Xiao Kang , Ouyang Ting , Liu Zhao‐Qing
Published: January 2021

The high charge–discharge voltage gap is one of the main bottlenecks of zinc–air batteries (ZABs) because of the kinetically sluggish oxygen reduction/evolution reactions (ORR/OER) on the oxygen electrode side. Thus, an efficient bifunctional catalyst for ORR and OER is highly desired. Herein, honeycomb‐like MnCo2O4.5 spheres were used as an efficient bifunctional electrocatalyst. It was demonstrated that both ORR and OER catalytic activity are promoted by MnIV‐induced oxygen vacancy defects and multiple active sites. Importantly, the multivalent ions present in the material and its defect structure endow stable pseudocapacitance within the inactive region of ORR and OER; as a result, a low charge–discharge voltage gap (0.43 V at 10 mA cm−2) was achieved when it was employed in a flexible hybrid Zn‐based battery. This mechanism provides unprecedented and valuable insights for the development of next‐generation metal–air batteries.
Tenfold Metalation of Ferrocene: Synthesis, Structures, and Metallophilic Interactions in FeC10(HgX)10
Authors: Rupf Susanne Margot , Schröder Gabriel , Sievers Robin , Malischewski Moritz
Published: January 2021

The permercuration of ferrocene was achieved by reacting ferrocene with 10 equivalents of mercury(II) butyrate Hg(O2CC3H7)2 in a facile one‐pot reaction in multi‐gram scale and high yields. The butyrate groups in FeC10(HgX)10 (X=O2CC3H7) can be exchanged by treatment with trifluoro‐ or trichloroacetic acid (X=O2CCF3, O2CCCl3). Substitution of the trifluoroacetate groups by halides (X=Cl, F) proceeds easily in aqueous THF. The completeness of metalation was confirmed by NMR and vibrational spectroscopy, mass spectrometry, as well as elemental analysis. Additionally, the first crystal structures of permetallated metallocenes are presented: FeC10(HgX)10 (X=Cl, O2CCF3, O2CCCl3).
Fine‐scale spatial variation in fitness is comparable to disturbance‐induced fluctuations in a fire‐adapted species
Authors: Coutts Shaun R. , Quintana‐Ascencio Pedro F. , Menges Eric S. , Salguero‐Gómez Roberto , Childs Dylan Z.
Published: January 2021

The spatial scale at which demographic performance (e.g., net reproductive output) varies can profoundly influence landscape‐level population growth and persistence, and many demographically pertinent processes such as species interactions and resource acquisition vary at fine scales. We compared the magnitude of demographic variation associated with fine‐scale heterogeneity (<10 m), with variation due to larger‐scale (>1 ha) fluctuations associated with fire disturbance. We used a spatially explicit model within an IPM modeling framework to evaluate the demographic importance of fine‐scale variation. We used a measure of expected lifetime fruit production, EF, that is assumed to be proportional to lifetime fitness. Demographic differences and their effects on EF were assessed in a population of the herbaceous perennial Hypericum cumulicola (~2,600 individuals), within a patch of Florida rosemary scrub (400 × 80 m). We compared demographic variation over fine spatial scales to demographic variation between years across 6 yr after a fire. Values of EF changed by orders of magnitude over <10 m. This variation in fitness over fine spatial scales (<10 m) is commensurate to postfire changes in fitness for this fire‐adapted perennial. A life table response experiment indicated that fine‐scale spatial variation in vital rates, especially survival, explains as much change in EF as demographic changes caused by time‐since‐fire, a key driver in this system. Our findings show that environmental changes over a few tens of meters can have ecologically meaningful implications for population growth and extinction.
Regression of severe heart failure after combined left ventricular assist device placement and sleeve gastrectomy
Authors: Nathan Sriram S. , Iranmanesh Pouya , Gregoric Igor D. , Akay Mehmet H. , Kumar Sachin , Akkanti Bindu H. , Salas de Armas Ismael A. , Patel Manish , Felinski Melissa M. , Shah Shinil K. , Bajwa Kulvinder S. , Kar Biswajit
Published: January 2021

Patients who suffer morbid obesity and heart failure (HF) present unique challenges. Two cases are described where concomitant use of laparoscopic sleeve gastrectomy (LSG) and left ventricular assist device (LVAD) placement enabled myocardial recovery and weight loss resulting in explantation. A 29‐year‐old male patient with a body mass index (BMI) of 59 kg/m2 and severe HF with a left ventricular ejection fraction (LVEF) of 20–25% underwent concomitant LSG and LVAD placement. Sixteen months after surgery, his BMI was reduced to 34 kg/m2 and his LVEF improved to 50–55%. A second 41‐year‐old male patient with a BMI of 44.8 kg/m2 with severe HF underwent the same procedures. Twenty‐four months later, his BMI was 31.1 kg/m2 and his LVEF was 50–55%. In both cases, the LVAD was successfully explanted and patients remain asymptomatic. HF teams should consult and collaborate with bariatric experts to determine if LSG may improve the outcomes of their HF patients.
New Polymorphism for Ba3Zn2(BO3)3F with Two Polymorphs Exhibiting Anomalous Phase Transition
Authors: Chen Yanna , Zhang Wenyao , An Donghai , Abudoureheman Maierhaba , Chen Zhaohui , Mi Hongyu
Published: January 2021

A new polymorph of Ba3Zn2(BO3)3F, α‐Ba3Zn2(BO3)3F, was synthesized and its structure was determined by single crystal X‐ray diffraction. The two polymorphous phases of Ba3Zn2(BO3)3F are referred to as α‐ and β‐Ba3Zn2(BO3)3F according to their synthesis temperature from low to high. Both structures exhibit a similar three‐dimensional (3D) framework, while the two‐dimensional (2D) 2∞[Zn2B2O7] layers in their structures show different configurations and feature diverse topological structures. Interestingly, an anomalous phase transition, that is, the high‐temperature β‐phase having a higher density, was observed and further confirmed by detailed structural analyses, which shows that the unusual density evolution mainly originates from the different configurations of 2∞[Zn2B2O7] layers. Moreover, the phase transformation was characterized by powder X‐ray diffraction (PXRD) and differential scanning calorimetry (DSC) analyses.
Nanoscale properties of lead halide perovskites by scanning tunneling microscopy
Authors: Wieghold Sarah , Nienhaus Lea
Published: January 2021

Since the introduction of lead halide perovskites, tremendous progress has been made regarding their stability, reproducibility and durability. However, one of the issues that remains is related to the interfacial atomic structure arrangement and structure‐property relationship under optical and electrical stimuli. In this critical review, we highlight the recent progress using scanning tunneling microscopy (STM) to understand the nanoscale properties and dynamic processes occurring in these halide perovskite materials. STM is known to be a very challenging technique, which is reflected by the low number of relevant publications in the last years. These initial reports mirror the unique potential of STM to give Ångstrom‐scale insight into the (opto)‐electronic properties, morphology and underlying electronic structure and provide a path toward harnessing the full potential of these materials. However, care must be taken to understand the effects of the perturbations caused by STM and tailor the measurement conditions accordingly.

image
The Story of the AEA Competencies Task Force (2015–2018)
Authors: Tucker Susan A. , Barela Eric , Miller Robin Lin , Podems Donna R.
Published: January 2021

This chapter tells the story of American Evaluation Association's (AEA's) Competencies Task Force. During the 1990s, the AEA Board addressed issues related to the professionalization of the field, but chose not to move ahead with the development of competencies. Twenty years later, the global expansion of evaluation led to increasing professionalization around the world. In 2015, AEA's Board created a Competencies Task Force to formally address the issue of developing evaluator competencies for the association. This chapter describes the three‐year development process: the Task Force formation, its processes, the multiple forms of feedback solicited and received, the eventual outcomes, and emerging follow‐up strategies. It ends with a critique of the process by addressing what we believe the Task Force did well and what, in hindsight, it might have done differently.
Thermoelectric effect and devices on IVA and VA Xenes
Authors: Zhu Beibei , Chen Qichao , Jiang Siyao , Holt Milo , Zhu Weinan , Akinwande Deji , Tao Li
Published: January 2021

Emerging Xenes, mostly group IVA and VA elemental two‐dimensional (2D) materials, have small and tunable band gaps between graphene and transition metal dichalcogenides, giving versatile electrical properties. While their microelectronic or optoelectronic properties are being extensively explored, there remains a lack of study on Xenes' uniquely advantageous thermoelectric performance. This review highlights state‐of‐the‐art experimental and theoretical progress in the thermoelectric effect and devices of IVA and VA Xenes. Vertically displaced, a.k.a. “buckled” or “puckered,” atomic arrays result in exotic and tunable electrical or thermal transport behaviors. Different from chemical doping strategies usually employed in bulk thermoelectric materials, 2D Xenes can be tuned by physical means, such as atomic layer control and quantum confinement effects. A precise and compatible platform for 2D thermoelectric effect and devices study is available via the engagement between micro/nanofabrication of 2D Xene transistors and thermal property measurement techniques. This review also reveals potential thermoelectric applications of Xenes and their compounds (Bi2Te3, Bi2Se3, etc.), such as accurate stretchable temperature sensors, fast terahertz photodetectors, and so on.

image
ROR1‐AS1 knockdown inhibits growth and invasion and promotes apoptosis in NSCLC cells by suppression of the PI3K/Akt/mTOR pathway
Authors: Li Fengbo , Gu Fengming , Li Qian , Zhai Chaoshuan , Gong Rui , Zhu Xuezhuan
Published: January 2021

The role of ROR1‐AS1 in non‐small‐cell lung cancer (NSCLC) remains unclear. Therefore, we aimed to investigate the functional role of ROR1‐AS1 in NSCLC and to explore the underlying mechanisms. 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyl‐tetrazolium bromide assay was performed to detect cell proliferation. Transwell assay was performed to evaluate cell invasive ability. Cell apoptotic rates and caspase‐3/7 activity were determined to evaluate apoptosis. The expression levels of PI3K/Akt/mTOR pathway‐related proteins were measured using Western blot analysis. Results showed that ROR1‐AS1 expression was upregulated in NSCLC samples. Knockdown of ROR1‐AS1 inhibited the viability and invasive ability of NSCLC cells. Knockdown of ROR1‐AS1 induced apoptotic rate and caspase‐3/7 activity and suppressed xenograft NSCLC tumor growth. In addition, ROR1‐AS1 knockdown inhibited the activation of the PI3K/Akt/mTOR pathway in NSCLC cells. However, treatment with 740Y‐P prevented the effects of si‐ROR1‐AS1 on viability, invasive ability, and apoptosis of NSCLC cells. These findings implied that ROR1‐AS1 played an oncogenic role in NSCLC via regulating the PI3K/Akt/mTOR pathway.
Structural, spectral, electronic, and molecular docking investigations on N,N‐dimethyl‐2‐[(1E)‐({[(methylsulfanyl)methanethioyl]amino}imino)methyl]aniline
Authors: Bingöl Alpaslan Yelda , Sert Yusuf , Sohtun Winaki P. , Velusamy Marappan , Gökce Halil
Published: January 2021

In this research, a joint theoretical and experimental investigation was performed on the structural and spectral data (FT‐IR, Laser‐Raman, NMR, and UV–vis) of N,N‐dimethyl‐2‐[(1E)‐({[(methylsulfanyl)methanethioyl]amino}imino)methyl]aniline molecule. The theoretical electronic structure analyses were fulfilled by the density functional theory at the B3LYP level with the 6‐311++G(d,p) basis set in the gas phase of the isolated compound at the ground state. The vibrational works were analyzed in terms of potential energy distribution analysis to make the assignments of fundamental vibrational frequencies and the assigned modes of the title compound were compared with the reported experimental vibrational data. Later, Hirshfeld surface analysis over crystalline structure of the title compound was made to define the possible inter‐molecular interactions. In addition, the HOMO (highest occupied molecular orbital), LUMO (lowest unoccupied molecular orbital), UV–vis, and molecular electrostatic potential analyses were done. The molecular docking investigation was done in order to analyze the presence of interactions between the title ligand compound and the receptor protein 2VN0.
Synthesis, photooxygenation, and characterization of new angular furoquinolinone derivatives, a new furocoumarin bioisoster
Authors: Elgogary Sameh , Abd Elghafar Hoda , Mashaly Mohammad
Published: January 2021

Synthesis of angular furoquinolinone derivatives with a new skeleton structure was accomplished via Williamson reaction of hydroxyquinolinones with α‐haloketones, such as 3‐chloro‐2‐butanone and phenacyl bromide, followed by treatment with polyphosphoric acid (PPA). The synthesized angular furoquinolinones were photooxygenated in chloroform or dimethyl formamide and in the presence of tetraphenylporphyrin (TPP) as a singlet oxygen sensitizer (1O2). The photooxygenation reactions furnished the photocleaved product through the [2 + 2] cycloaddition reaction. All photoproducts were isolated and fully characterized by spectral analyses.
Chemerin located in bone marrow promotes osteogenic differentiation and bone formation via Akt/Gsk3β/β‐catenin axis in mice
Authors: Li Jun , Zhang Ting , Huang Chenglong , Xu Min , Xie Wenhua , Pei Qilin , Xie Xinxin , Wang Bin , Li Xi
Published: January 2021

Chemerin, a secreted protein mainly produced by adipocytes and hepatocytes, plays a variety of roles in endocrine or paracrine signaling. As reported in human epidemiology, chemerin was correlated with osteoporosis. And the previous in vitro study found that chemerin knockdown promoted osteogenesis and inhibited adipogenesis. However, the function of chemerin in bone metabolism and the underlying mechanism remains unclear. In this study, we uncovered the in vivo function of chemerin in bone homeostasis. We discovered that in obese mice, chemerin was increased in serum, while decreased in the bone marrow; and the chemerin expression in bone tissue was positively correlated with osteogenic genes. To further investigate the function of chemerin in bone metabolism, we generated chemerin deficiency and overexpression mice. We found bone mass and osteogenesis were decreased in chemerin deficiency mice, while were increased in chemerin overexpression mice. Furthermore, we observed that the chemerin expression increased during osteogenic differentiation of MSCs. Besides, we verified that chemerin promoted osteogenic differentiation in C3H10T1/2 cells and BMSCs through Akt/Gsk3β/β‐catenin axis. Treatment with Akt inhibitor (MK2206) abolished the promoting effect of chemerin on osteogenic differentiation and active β‐catenin. Together, our results suggest chemerin in bone marrow, not in serum, promotes osteogenic differentiation and bone formation via Akt/Gsk3β/β‐catenin axis. Chemerin may serve as a therapeutic strategy for osteoporosis.
Archetypal autophagic players through new lenses for bone marrow stem/mature cells regulation
Authors: Agas Dimitrios , Sabbieti Maria Giovanna
Published: January 2021

The bone marrow landscape consists of specialized and stem/progenitor cells, which coordinate important tissue‐related and systemic physiological features. Within the marrow cavity, stem/progenitor and differentiated hematopoietic and skeletal cells congregate into dynamic functional assemblies throughout specific anatomical regions, termed niches. There is a need for better understanding of the bone marrow microareas, through exploration of the intramural physical and molecular interactions of the distinctive cell populations. The elective liaisons established among the mesenchymal/stromal stem cell and hematopoietic stem cell lineage trees play a key role in orchestrating the stem/mature cell behavior and customized hierarchies within bone marrow cell populations. Recently, the autophagic apparatus has been discovered to be an important feature of bone marrow homeostasis. Autophagy‐related factors involved in the labyrinthic and highly dynamic bone marrow workshop redesign the niche framework by coordinating the operational schedule of pluripotent stem and mature cells. The following report summarizes the most recent breakthroughs in our understanding of the intramural relationships between bone marrow cells and key autophagic mediators. Doubtless, the consideration of the autophagy‐related and unrelated functions of main players, such as p62, Atg7, Atg5, and Beclin‐1 remains a compelling task to thoroughly understand the complex relations between the heterogenic cell types that populate bone marrow.
Role of the spinal canal compliance in regulating posture‐related cerebrospinal fluid hydrodynamics in humans
Authors: Alperin Noam , Burman Ritambhar , Lee Sang H.
Published: January 2021

Mechanical compliance of a compartment is defined by the change in its volume with respect to a change in the inside pressure. The compliance of the spinal canal regulates the intracranial pressure (ICP) under postural changes. Understanding how gravity affects ICP is beneficial for poorly understood cerebrospinal fluid (CSF)‐related disorders. The aim of this study was to evaluate postural effects on cranial hemo‐ and hydrodynamics. This was a prospective study, which included 10 healthy volunteers (three males, seven females, mean ± standard deviation age: 29 ± 7 years). Cine gradient‐echo phase‐contrast sequence acquired at 0.5 T, “GE double‐doughnut” scanner was used. Spinal contribution to overall craniospinal compliance (CSC), craniospinal CSF stroke volume (SV), magnetic resonance (MR)‐derived ICP (MR‐ICP), and total cerebral blood flow (TCBF) were measured in supine and upright postures using automated blood and CSF flows quantification. Statistical tests performed were two‐sided Student's t‐test, Cohen's d, and Pearson correlation coefficient. MR‐ICP and the craniospinal CSF SV were significantly correlated with the spinal contribution to the overall CSC (r = 0.83, p < 0.05) and (r = 0.62, p < 0.05), respectively. Cranial contribution to CSC increased from 44.5% ± 16% in supine to 74.9% ± 8.4% in upright posture. The average MR‐ICP dropped from 9.9 ± 3.4 mmHg in supine to −3.5 ± 1.5 mmHg. The CSF SV was over 2.5 times higher in the supine position (0.55 ± 0.14 ml) than in the upright position (0.21 ± 0.13 ml). In contrast, TCBF was slightly higher in the supine posture (822 ± 152 ml/min) than in the upright posture (761 ± 139 ml/min), although not statistically significant (p = 0.16). The spinal‐canal compliance contribution to CSC is larger than the cranial contribution in the supine posture and smaller in the upright posture. Thereby, the spinal canal plays a role in modulating ICP upon postural changes. The lower pressure craniospinal CSF system was more affected by postural changes than the higher‐pressure cerebral vascular system. Craniospinal hydrodynamics is affected by gravity and is likely to be altered by its absence in space.

Level of Evidence

4

Technical Efficacy Stage

2
In vivo liver thermoacoustic imaging and demonstration based on localization wire
Authors: Xiang Hongjin , Zheng Zhu , Huang Lin , Qiu Tingting , Luo Yan , Jiang Huabei
Published: January 2021

Purpose

Liver disease causes significant morbidity and mortality worldwide. Liver imaging plays an essential role in the noninvasive liver disease evaluation because of the limitation of liver biopsy. This paper aims to image in vivo liver with thermoacoustic imaging (TAI) and demonstrate this liver imaging technique with a cross‐validation method.

Methods

The imaging system composed of a large aperture antenna and a flexible transducer array was used, and we performed the position calibration using the delay and sum algorithm. The localization wire was utilized in the cross‐validation of in vivo liver TAI.

Results

We successfully validated in vivo liver TAI. In vivo images of different liver lobes without labels were observed. The imaging depth reached about 4 cm.

Conclusions

TAI has the potential to image the liver and provide useful dielectric properties of the liver tissue. This study realized the first in vivo liver TAI, suggesting its prospect in detecting liver disease noninvasively.
Phthalate and Bisphenol Urinary Concentrations, Body Fat Measures, and Cardiovascular Risk Factors in Dutch School‐Age Children
Authors: Silva Carolina C. V. , Jaddoe Vincent W. V. , Sol Chalana M. , El Marroun Hanan , Martinez‐Moral Maria‐Pilar , Kannan Kurunthachalam , Trasande Leonardo , Santos Susana
Published: January 2021

Objective

The purpose of this study was to investigate the associations of urinary phthalates and bisphenols at age 6 years old with body fat and cardiovascular risk factors at 6 and 10 years and with the change from 6 to 10 years.

Methods

Among 471 Dutch children, the phthalates and bisphenols urinary concentrations at 6 years and BMI, fat mass index, android fat mass, blood pressure, glucose, insulin, and lipids blood concentrations at 6 and 10 years were measured.

Results

An interquartile range increase in di‐n‐octyl phthalate (DNOP) metabolites concentrations at 6 years was associated with an increased risk of overweight at 6 and 10 years (odds ratio: 1.44; 95% CI: 1.11‐1.87, and 1.43; 95% CI: 1.09‐1.86, respectively). Also, higher DNOP metabolites concentrations were associated with higher fat mass index at 6 years, higher systolic blood pressure at 10 years, a decrease in high‐density lipoprotein cholesterol, and an increase in triglycerides concentrations from 6 to 10 years (P < 0.05). Higher total bisphenols and bisphenol A concentrations were associated with a decrease in BMI from 6 to 10 years (P < 0.01).

Conclusions

DNOP metabolites are associated with overweight and an adverse cardiovascular profile in childhood. Total bisphenols and bisphenol A are associated with a decrease in BMI from 6 to 10 years.
Dynamic Stability of Viscoelastic Bars under Pulsating Axial Loads
Authors: Kern Dominik , Gypstuhl Richard , Groß Michael
Published: January 2021

Recent applications require the extension of stability theory to axially loaded viscoelastic bars. For elastic bars it is known that a pulsating load leads to a Mathieu equation. Meaning, there are some instable regions before the static buckling load and some stable regions beyond, depending on the excitation (amplitude, frequency, offset). To fill this gap we follow along the lines of Weidenhammer and adopt the classical Euler‐Bernoulli beam kinematics for coupled longitudinal and bending vibrations. Modeling viscoelasticity by the Standard Linear Solid model introduces an internal variable. Hence, there are auxiliary transversal and longitudinal displacements corresponding to the internal variable in addition to the physical transversal and longitudinal displacements of the bar centerline. The modeling further assumes only longitudinal vibrations in the stable regime, thus there are no bending vibrations and the description simplifies to a system of linear partial differential equations. Further, a one‐sided coupling is assumed for the stability analysis, i.e. the longitudinal vibrations are prescribed and induce bending vibrations. Still, the time‐variant coefficients of the transversal dynamics make it difficult to find an analytical solution. Consequently, an approximation is obtained by Ritz method from Hamilton's principle. Applying the eigenforms of elastic buckling as trial functions finally leads to a system of rheolinear ordinary differential equations. Its stability chart with respect to static and harmonic load components is calculated numerically by Floquet theory.
Predicting laser‐induced cavitation near a solid substrate
Authors: Denner Fabian , Evrard Fabien , Reuter Fabian , Gonzalez-Avila Silvestre Roberto , van Wachem Berend , Ohl Claus-Dieter
Published: January 2021

The asymmetric collapse of cavitation bubbles near a solid substrate generates large wall shear stresses, the precise magnitude of which is still not known with certainty. By comparing numerical simulations and experiments of a laser‐induced cavitation bubble near a solid substrate, we demonstrate that an accurate measurement of the pressure pulse emitted during bubble inception and of the maximum bubble radius allow a unique initialisation of the simulation. This allows an accurate reproduction of the asymmetric collapse, with reliable predictions of the shear stress and pressure generated at the substrate.
Structure‐preserving discretization of a port‐Hamiltonian formulation of the non‐isothermal Euler equations
Authors: Hauschild Sarah-Alexa , Marheineke Nicole
Published: January 2021

The port‐Hamiltonian (pH) formulation of partial‐differential equations (pdes) and their numerical treatment have been elaborately studied lately. In this context we consider the non‐isothermal flow of a compressible fluid. Starting from the pdes we derive a pH formulation for Euler‐type equations in the weak sense on one pipe. One advantage of pH systems is that fundamental physical properties, like energy dissipation and mass conservation, are encoded in the system structure. Therefore, structure‐preservation during approximation is most important. Based on the weak form we introduce a structure‐preserving Galerkin approximation with mixed finite elements. A numerical example supports the theoretical results.