bluuebunny/crossref_metadata_2025 huggingface dataset:
Fluorographene and Its Composites: Fundamentals, Electrophysical Properties, DFT Studies, and Advanced Applications
Authors: Borse Rahul Anil , Kale Manoj B. , Sonawane Shirish H. , Wang Yaobing
Published: April 2022

Fluorographenes (FGs) are the youngest family of graphene derivatives 2D layer‐structure, which has changed the hybridization state from sp2‐to‐sp3 carbon and unique CF bonds impacting physical and chemical properties. Due to various types of CF bonds, wide bandgap, tunable F/C ratios, and unique nanostructure, the FGs show attractive physicochemical properties. Owing to the extraordinary properties, the researchers have recently paid attention to exploring FGs into fluorographene composites (FG‐Cs) as a potential candidate for fundamental advances in the field of the energy system, optoelectronic, biomedical, and aeronautics. Despite their promise, in‐depth experimental and theoretical studies of FGs over FG‐Cs are not explored systematically. This review focuses on the recent experimental developments on FGs and FG‐Cs, including fundamentals and electrophysical properties, synthesis methods, conductivity, hydrophobicity, and magnetic nature. Further, for the validation, the theoretical studies, first‐principle study/density functional theory emphasize their real intrinsic activity, stability, and effects of F content, defects, and doping mechanism. Finally, the wide applications, energy systems to biomedical and optoelectronics to the aerospace industry, along with challenges and future perspectives, are also discussed. This review aims to conclude valuable insights into the fundamental science and perspective toward highly efficient FG‐C‐based catalysts engineering in advanced applications.
Metal‐Free Perovskite Piezoelectric Nanogenerators for Human–Machine Interfaces and Self‐Powered Electrical Stimulation Applications
Authors: Wu Han‐Song , Wei Shih‐Min , Chen Shuo‐Wen , Pan Han‐Chi , Pan Wei‐Pang , Huang Shih‐Min , Tsai Meng‐Lin , Yang Po‐Kang
Published: April 2022

Single crystal metal‐free halide perovskites have received great attention in recent years owing to their excellent piezoelectric and ferroelectric properties. However, the nanotoxicity and piezoelectricity within the nanoscale of such materials have yet been reported for the demonstration of practical applications. In this work, the observation of intrinsic piezoelectricity in metal‐free perovskite (MDABCO‐NH4I3) films using piezoresponse force microscopy (PFM) is reported. A cytotoxicity test is also performed on MDABCO‐NH4I3 to evaluate its low‐toxic nature. The as‐synthesized MDABCO‐NH4I3 is further integrated into a piezoelectric nanogenerator (PENG). The MDABCO‐NH4I3‐based PENG (MN‐PENG) exhibits optimal output voltage and current of 15.9 V and 54.5 nA, respectively. In addition, the MN‐PENG can serve as a self‐powered strain sensor for human–machine interface applications or be adopted in in vitro electrical stimulation devices. This work demonstrates a path of perovskite‐based PENG with high performance, low toxicity, and multifunctionality for future advanced wearable sensors and portable therapeutic systems.
Effect of Aromatic Solvents Residuals on Electron Mobility of Organic Single Crystals
Authors: Xue Guobiao , Peng Boyu , Ye Tao , Wu Jiake , Zhao Yujie , Liu Yujing , Yamada Hiroko , Chen Hongzheng , Li Hanying
Published: April 2022

Balanced electron and hole transport properties are essential for various organic electrical/optoelectrical applications such as organic solar cells, complementary circuits, and light‐emitting transistors. However, the electron transport in organic semiconductor lags far behind the hole side, making it with vital significance to seek the factors that limit the electron mobility. Here, the authors demonstrate that the π‐conjugated solvents, as essential components in the widely‐used solution processing techniques, can significantly suppress the electron transport if they are not properly removed and trapped as residuals. Single crystals of typical p‐type materials exhibit a transition from p‐type behavior to ambipolar conductance via reducing the amount of solvent residuals, and the same effect is confirmed by varied p‐type materials and solvents. The highest electron mobility reaches 0.027 cm2 V−1 s−1 and 0.029 cm2 V−1 s−1 for 6,13‐bis(triisopropylsilylethynyl)pentacene and 5,15‐bis(triisopropylsilylethynyl)tetrabenzoporphyrin, respectively. This work discloses the non‐negligible existence of solvent residuals even in high quality, long‐range ordered organic single crystals, and further provides efficient strategies to harvest the n‐type behaviors of organic semiconductor materials.
Estimation of output measurement variances for error‐in‐variables model parameter estimation
Authors: Abdi Kaveh , McAuley Kimberley B.
Published: April 2022

Error‐in‐variables model (EVM) methods require information about variances of input and output measured variables when estimating the parameters in mathematical models for chemical processes. In EVM, using replicate experiments for estimating output measurement variances is complicated because true values of inputs may be different when multiple attempts are made to repeat an experiment. To address this issue, we categorize attempted replicate experiments as: (i) true replicates (TRs) when uncertain inputs are the same in replicated runs and (ii) pseudo replicates (PRs) when measured inputs are the same, but unknown true values of inputs are different. We propose methodologies to obtain output measurement variance estimates and associated parameter estimates for both situations. We also propose bootstrap methods for obtaining joint‐confidence information for the resulting parameter estimates. A copolymerization case study is used to illustrate the proposed techniques. We show that different assumptions noticeably affect the uncertainties in the resulting reactivity‐ratio estimates.
Diversification in the Rosales is influenced by dispersal, geographic range size, and pre‐existing species richness
Authors: Simpson Andrew G. , Wing Scott L. , Fenster Charles B.
Published: April 2022

Premise

Biodiversity results from origination and extinction, justifying interest in identifying traits that influence this balance. Traits implicated in the success or failure of lineages include dispersal, colonization ability, and geographic range size. We investigated the impact of dispersal and range size on contemporary diversity in the Rosales.

Methods

We used the multiple‐state speciation and extinction (MuSSE) method to explore the effects on genus‐level diversification of two genus‐level traits (geographic range size and within‐genus proclivity to speciate) and two species traits (seed dispersal and growth habit) and the multiple hidden‐state speciation and extinction (MuHiSSE) method for species‐level associations. Finally, we conducted a PGLS (phylogenetic least‐squares) analysis to distinguish between speciation within genera versus origination of new genera.

Results

At the species level, animal dispersal enhances diversification rate in both woody and herbaceous lineages, while woody lineages without animal dispersal have higher extinction rates than speciation rates. At the genus level, herbaceous taxa have positive diversification rates regardless of other character states. Diversification rate variation is also explained by two interactions: (1) a three‐way interaction between large geographic range, animal‐mediated dispersal, and high within‐genus species richness, whereby genera possessing all three traits have high diversification rates, and (2) a four‐way interaction by which the three‐way interaction is stronger in woody genera than in herbaceous genera.

Conclusions

Colonization ability may underlie the relationship between dispersal type and range size and may influence past diversification rates by decreasing extinction rates during late Cenozoic climate volatility. Thus, colonization ability could be used to predict future extinction risk to aid conservation.
Superlattices with coupled channels and transfer matrices
Authors: Anzaldo‐Meneses Alfonso
Published: April 2022

We study analytically threshold and resonance effects in superlattices using the well‐known transfer matrix technique. For this analysis we take advantage of a new parametrization of the scattering amplitudes. In particular, threshold effects, analogous to the so‐called “Wigner cusps” of nuclear reactions, follow when a channel is opened for non‐zero coupling. Sharp resonances of Lorenzian shape are also found only in the presence of coupling. It could be very interesting to look for experimental evidences of these effects. We expect that this approach allows to study systems with spin and under external magnetic fields.
S‐matrix network models for coherent waves in random media: construction and renormalization
Authors: Janssen Martin , Merkt Rainer , Weymer Andreas
Published: April 2022

Networks of random quantum scatterers (S‐matrices) form paradigmatic models for the propagation of coherent waves in random media. S‐matrix network models cover universal localization‐delocalization properties and have some advantages over more traditional Hamiltonian models. In particular, a straightforward implementation of real space renormalization techniques is possible. Starting from a finite elementary cell of the S‐matrix network, hierarchical network models can be constructed by recursion. The localization‐delocalization properties are contained in the flow of the forward scattering strength (‘conductance’) under increasing system size. With the aid of ‘small scale’ numerics qualitative aspects of the localization‐delocalization properties of S‐matrix network models can be worked out.
Critical level statistics of a quantum Hall system with Dirichlet boundary conditions
Authors: Potempa H. , Schweitzer L.
Published: April 2022

We investigate numerically the influence of Dirichlet boundary conditions on the nearest neighbor level spacing distribution P(s) of a two‐dimensional disordered tightbinding model in the presence of a strong perpendicular magnetic field. From the calculation of the second moment of P(s) it is shown that for Dirichlet boundary conditions, due to the presence of edge states, the position of the critical energy shifts with increasing system size to the location of the critical energy for periodic boundary conditions. An extrapolation to infinite system size results in different critical (scale independent) P(s) distributions for periodic and Dirichlet boundary conditions.
Electronic transport in disordered interacting systems
Authors: Vojta Thomas , Epperlein Frank
Published: April 2022

We numerically investigate the transport properties of disordered interacting electrons in three dimensions in the metallic as well as in the insulating phases. The disordered many‐particle problem is modeled by the quantum Coulomb glass which contains a random potential, long‐range unscreened Coulomb interactions and quantum hopping between different sites. We have recently developed the Hartree‐Fock based diagonalization (HFD) method which amounts to diagonalizing the Hamiltonian in a suitably chosen energetically truncated basis. This method allows us to investigate comparatively large systems. Here we calculate the combined effect of disorder and interactions on the dissipative conductance. We find that the qualitative influence of the interactions on the conductance depends on the relative disorder strength. For strong disorder interactions can significantly enhance the transport while they suppress the conductance for weak disorder.
Solving the Schrödinger equation on percolation structures by means of the equation of motion method
Authors: Dräger Julia , Halfpap Ole
Published: April 2022

We investigate the dynamical properties of the quantum percolation model at the critical percolation threshold pc in two dimensions by means of the spreading of a wave packet. We find that for t → ∞ the mean square displacement R2(t) converges to R2(t) ≃ 92. In order to obtain a microscopic insight we investigate the averaged squared wave function 〈|ψ(r,t)|2〉 for fixed time t and find that up to a crossover distance r× its spatial decay is given by a stretched exponential with exponent u ≃ 0.58. The exponent u agrees with the exponent dψ obtained recently for the corresponding time independent localization problem. Furthermore we find that the averaged moments 〈|ψ(r,t)|2q〉 for fixed time t scale in a multifractal way 〈|ψ(r,t)|2q〉 ∼ 〈|ψ(r,t)|2〉τ(q) with τ(q) ∼ qδ and δ ≃ 1.25 ± 0.05.
Transient increase of high momenta in quantum wave‐packet collisions
Authors: Brouard S. , Muga J.G.
Published: April 2022

We study the transient increase of the upper tail of the momentum distribution in quantum wave‐packet collisions with an analytically solvable model; in particular its dependence with the barrier strength and incident momentum. This effect is a classically forbidden, universal feature of all quantum collisions.
Locality, QED and classical electrodynamics
Authors: Kreimer D.
Published: April 2022

We report on some conceptual changes in our present understanding of Quantum Field Theory and muse about possible consequences for the understanding of v > c signals.
Can EPR‐correlations be used for the transmission of superluminal signals?
Authors: Mittelstaedt P.
Published: April 2022

In a compound quantum system with EPR–like correlations a measurement of one subsystem induces instantaneously changes of the other subsystem, irrespective of the relative distance of the two subsystems. We consider several arguments which were put forward in recent years in order to show that these nonlocal effects cannot be used for superluminal communication. It turns out that the arguments mentioned above are merely plausible but not really stringent and convincing. This means that the question in the title of this paper is still open.
The velocity of probability transport in quantum mechanics
Authors: Melloy G.F. , Bracken A.J.
Published: April 2022

In his study of the ‘time of arrival’ problem in the nonrelativistic quantum mechanics of a single particle, Allcock [1] noted that the direction of the probability flux vector is not necessarily the same as that of the mean momentum of a wave packet, even when the packet is composed entirely of plane waves with a common direction of momentum. Packets can be constructed, for example for a particle moving under a constant force, in which probability flows for a finite time in the opposite direction to the momentum. A similar phenomenon occurs for the Dirac electron. The maximum amount of probabilitiy backflow which can occur over a given time interval can be calculated in each case.
On the role of a limiting velocity in constructive spacetime axiomatics
Authors: Schelb U.
Published: April 2022

The issue of superluminal velocities is looked at from the point of view of a spacetime axiomatics. Such theories construct the relativistic spacetime picture from simple, empirically based postulates. One important task is the convincing introduction of coordinates in spacetime, to which end “radar coordinates” are used. For this the existence of a finite limiting velocity of signals is absolutely necessary, but it may be superluminal without producing conflicts with causality on this level.
The Nambu–Goto theory of closed bosonic strings moving in 1 + 3–dimensional Minkowski space: the quantum algebra of observables
Authors: Pohlmeyer K.
Published: April 2022

A relevant part of the quantum algebra of observables for the closed bosonic strings moving in 1 + 3–dimensional Minkowski space is presented in the form of generating relations involving still one, as yet undetermined, real free parameter.
The Nambu‐Goto theory of closed bosonic strings moving in 1 + 3–dimensional Minkowski space: the construction of the quantum algebra of observables up to degree five
Authors: Handrich G. , Nowak C.
Published: April 2022

The quantum algebra of observables of closed bosonic strings moving in 1 + 3–dimensional Minkowski space is constructed up to degree five. All independent relations of degree four are computed; they involve three as yet undetermined parameters. Definitions and symbols are used as introduced in the above‐mentioned article.
On measuring gravitomagnetism via spaceborne clocks: a gravitomagnetic clock effect
Authors: Mashhoon B. , Gronwald F. , Theiss D.S.
Published: April 2022

The difference in the proper azimuthal periods of revolution of two standard clocks in direct and retrograde orbits about a central rotating mass is proportional to J/Mc2, where J and M are, respectively, the proper angular momentum and the mass of the source. It is shown that this circumstance is due to a special gravitomagnetic temporal structure around a rotating mass. In connection with this gravitomagnetic clock effect, we explore the possibility of using spaceborne standard clocks for detecting the gravitomagnetic field of the Earth.
Chiral supergravity and anomalies
Authors: Mielke Eckehard W. , Macías Alfredo
Published: April 2022

Similarly as in the Ashtekar approach, the translational Chern‐Simons term is, as a generating function, instrumental for a chiral reformulation of simple supergravity. After applying the algebraic Cartan relation between spin and torsion, the resulting canonical transformation induces not only a decomposition of the gravitational fields into selfdual and anti‐selfdual modes, but also a splitting of the Rarita‐Schwinger fields into their chiral parts in a natural way. In some detail, we also analyze the consequences for axial and chiral anomalies.
Einstein‐Proca model: spherically symmetric solutions
Authors: Obukhov Yuri N. , Vlachynsky Eugen J.
Published: April 2022

The Proca wave equation describes a classical massive spin 1 particle. We analyze the gravitational interaction of this vector field. In particular, the spherically symmetric solutions of the Einstein‐Proca coupled system are obtained numerically. Although at infinity the metric field approaches the usual Schwarzschild (Reissner‐Nordström) limit, we demonstrate the absence of black hole type configurations.
Anderson localization and the integer quantum Hall transition: a new perspective
Authors: Kettemann S. , Tsvelik A.
Published: April 2022

The autocorrelation function of spectral determinants (ASD) is used to probe a system of disordered electrons. It is represented as an effective partition function, and thus the problem is reduced to finding the spectrum of the respective effective Hamiltonian. A spectral gap above its ground state is argued to be a strong indication that all states are localized. This method is demonstrated for electrons in a quasi‐ 1– dimensional disordered metal wire as a function of a magnetic field, and for two‐dimensional disordered electrons in weak and strong magnetic fields.
Review of recent progress on numerical studies of the Anderson transition
Authors: Ohtsuki Tomi , Slevin Keith , Kawarabayashi Tohru
Published: April 2022

A review of recent progress in numerical studies of the Anderson transition in three dimensional systems is presented. From high precision calculations the critical exponentνfor the divergence of the localization length is estimated to beν= 1.57 ± 0.02 for the orthogonal universality class, which is clearly distinguished fromν= 1.43 ± 0.03 for the unitary universality class. The boundary condition dependences of some quantities at the Anderson transition are also discussed.
Exact eigenstates and transmission for two interacting electrons on quantum dots
Authors: Aharony A. , Entin‐Wohlman O. , Levinson Y. , Imry Y.
Published: April 2022

The eigenstates and the scattering transmission for two interacting electrons are found exactly for I quantum dots, including the hybridization with the states on the leads. The results imply limitations on the validity of the Coulomb blockade picture. The ground states for I = 1, 2 on a one–dimensional chain (modeling single and double quantum dots) exhibit quantum delocalization and magnetic transitions. The effective transmission T of two interacting electrons through one impurity (I = 1) is enhanced by a renormalization of the repulsive interaction, when one of the electrons is captured in a strongly localized state.
Critical Hamiltonians with long range hopping
Authors: Levitov L.S.
Published: April 2022

Critical states are studied by a real space RG in the problem with strong diagonal disorder and long range power law hopping. The RG ow of the distribution of coupling parameters is characterized by a family of non‐trivial fix points. We consider the RG flow of the distribution of participation ratios of eigenstates. Scaling of participation ratios is sensitive to the nature of the RG fix point. For some fix points, scaling of participation ratios is characterized by a distribution of exponents, rather than by a single exponent.

The RG method can be generalized to treat certain fermionic Hamiltonians with disorder and long range hopping. We derive the RG for a model of interacting two‐level systems. Besides couplings, in this problem the RG includes the density of states. The density of states is renormalized so that it develops a singularity near zero energy.
Horizon problem in a closed universe dominated by fluid with negative pressure
Authors: Stelmach Jerzy
Published: April 2022

We discuss the horizon problem in a universe dominated by fluid with negative pressure. We show that for generally accepted value of nonrelativistic matter energy density parameter Ωm0 < 1, the horizon problem can be solved only if the fluid influencing negative pressure (the so‐called “X” component) violates the point‐wise strong energy condition and if its energy density is sufficiently large (ΩX0 > 1). The calculated value of the ΩX0 parameter allowing for the solution of the horizon problem is confronted with some recent observational data. Assuming that pX/ρX < —0.6 we find that the required amount of the “X” component is not ruled out by the supernova limits. Since the value of energy density parameter Ωv0 for cosmological constant larger than 1 is excluded by gravitational lensing observations the value of the ratio pX/ρX should lie between the values —1 and —0.6 if the model has to be free of the horizon problem beeing at the same time consistent with observations. The value of ΩX0 + Ωm0 in the model is consistent with the constraints 0.2 < Ωtot < 1.5 following from cosmic microwave background observations provided that Ωm0 is low (<0.2).
The Limited Palette for Photonic Block‐Copolymer Materials: A Historical Problem or a Practical Limitation?
Authors: Wang Zhen , Chan Chun Lam Clement , Parker Richard M. , Vignolini Silvia
Published: April 2022

Block‐copolymer self‐assembly has proven to be an effective route for the fabrication of photonic films and, more recently, photonic pigments. However, despite extensive research on this topic over the past two decades, the palette of monomers and polymers employed to produce such structurally colored materials has remained surprisingly limited. In this Scientific Perspective, the commonly used block‐copolymer systems reported in the literature are summarized (considering both linear and brush architectures) and their use is rationalized from the point of view of both their historical development and physicochemical constraints. Finally, the current challenges facing the field are discussed and promising new areas of research are highlighted to inspire the community to pursue new directions.
Photosensitized [2+2]‐Cycloadditions of Alkenylboronates and Alkenes
Authors: Liu Yanyao , Ni Dongshun , Stevenson Bernard G. , Tripathy Vikrant , Braley Sarah E. , Raghavachari Krishnan , Swierk John R. , Brown M. Kevin
Published: April 2022

A new strategy for the synthesis of highly versatile cyclobutylboronates via the photosensitized [2+2]‐cycloaddition of alkenylboronates and alkenes is presented. The process is mechanistically different from other processes in that energy transfer occurs with the alkenylboronate as opposed to the other alkene. This strategy allows for the synthesis of an array of diverse cyclobutylboronates. The conversion of these adducts to other compounds as well as their utility in the synthesis of melicodenine C is demonstrated.
Toward Label‐Free Optical Multiplexing of Analytes in Indicator Release Lateral Flow Assays via Detection Zones Containing Tailored Capture Materials
Authors: Climent Estela , Wan Wei , Rurack Knut
Published: April 2022

The use of macromolecules and materials immobilized in the detection zone of test strips for indicator capture and focusing in label‐free lateral flow assays (LFAs) is described, with emphasis on its future use in low number multiplexing. Several materials such as polyelectrolytes, functionalized mesoporous silica micro‐ and nanoparticles, chemically modified cellulose or glass fibre (GF) membranes and molecularly imprinted polymer gels coated onto membranes were studied in model assays, before the most promising materials were combined with antibody‐gated indicator delivering (gAID) sensor materials. Cellulose, nitrocellulose and GF membranes were used as supports and highly fluorescent dyes of different charge states as model indicators. Combination of the best performing capture materials with gAID systems made it possible to distinctly increase the sensitivity and reduce the measurement uncertainty in the LFA testing of pentaerythritol tetranitrate (PETN) in aqueous samples. In addition, dual‐plexing of PETN and 2,4,6‐trinitrotoluene (TNT) was realized on a single test strip containing two dedicated capture zones.
Graft polymerization of methyl methacrylate on the surface of poly(ethylene‐co‐tetrafluoroethylene) using benzoyl peroxide as initiator
Authors: Mizuta Yusuke , Sugimoto Ryuichi , Okada Hiromu , Zhao Chao , Kobiro Kazuya , Nishiwaki Nagatoshi
Published: April 2022

The surface of a poly(ethylene‐co‐tetrafluoroethylene) (ETFE) film was modified by benzoyl peroxide (BPO)‐initiated graft polymerization of methyl methacrylate (MMA). After graft polymerization, the appearance of the ETFE film changed considerably, and the Fourier transform infrared (FT‐IR) spectra showed absorption peaks attributed to carbonyl functionalities. The efficiency of graft polymerization was strongly influenced by several factors such as the reaction temperature, reaction time, and concentration of BPO. The highest graft yield (69%) was obtained at 0.1 mol% BPO concentration and at a reaction temperature of 75°C for 24 h. The properties of the ETFE film surface were altered by the graft polymerization of MMA, which facilitated dyeing of the surface.
Development of ionic liquid plasticized high‐tensile starch‐protein‐sorghum bran composite films with antimicrobial activity
Authors: Tyagi Varee , Wang Yixiang , Bhattacharya Bhaswati
Published: April 2022

Ionic liquid (1‐butyl‐3‐methyl imidazolium chloride—[bmim]Cl) was used as a plasticizer alternative to enhance the mechanical strength of the starch‐zein composite films. Additionally, sorghum bran extract (SBE) was utilized as a sustainable source of bioactive compounds to introduce the antimicrobial activity to the composite films. [Bmim]Cl provided better solubilization capacity thereby enhancing the compatibility of film components. Thus, [bmim]Cl substantially improved the tensile strength and elongation at break of the ionic liquid plasticized (8.93 ± 1.59 MPa and 29.53 ± 0.86%) as well as sorghum bran functionalized films (8.99 ± 0.42 MPa and 21.91 ± 0.76%). Incorporation of SBE to the potato starch‐zein film solution enhanced opacity and attributed antioxidant properties to the composite film and that endorsed the possibility of inhibiting lipid peroxidation. Furthermore, the sorghum bran functionalized films possessed antimicrobial activity against Escherichia coli, making them appropriate for active packaging applications.
Structure–property relationships and constitutive viscoelastic behaviors of polyether‐block‐amide elastomers in melt and solid states
Authors: Ercan Nevra , Durmus Ali
Published: April 2022

In this study, effects of copolymer composition on the structural, thermal, and viscoelastic properties of segmented multi‐block polyamide elastomers (PEBAX® 3533, 5533, and 6333) and polyamide‐12 (PA12) were quantified by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry, and dynamic mechanical analysis (DMA) methods and rheological measurements. Soft segment, poly(tetramethylene oxide) (PTMO), contents of copolymers were proved by FTIR analysis. It was found that the increase in PTMO content dramatically reduced the crystallization and melting temperatures and degree of crystallinity values of copolymers. Different rheological test protocols performed in melt state revealed that zero shear rate viscosity values of polyamide elastomers increased with the increasing amount of hard segment. On the other hand, increase in hard segment content yielded lower flow activation energy value. In this study, we mainly focused on understanding quantitative relationships between block copolymer structure and their rheological behaviors and found that the soft segment content of ~40 (mole %) is the critical point for changing the rheological behaviors of block copolymer PAEs, dramatically. DMA measurements implied that the solid‐state viscoelastic behaviors of samples were governed by the hard content of copolymers. Higher hard content decreased long‐term creep strain and creep rate.
Monoamine‐modified thin film composite nanofiltration membrane for permselective separation of fermentation bioproducts
Authors: Gonzales Ralph Rolly , Shintani Takuji , Sunami Shunsuke , Sasaki Yuji , Nakagawa Keizo , Yoshioka Tomohisa , Matsuyama Hideto
Published: April 2022

One process involved in biorefinery for generation of value‐added products is fermentation. After fermentation, the downstream bioproduct purification process is conventionally performed by organic solvent extraction, which is environmentally‐hazardous and costly. Membrane‐based separation is a cost‐efficient and environmentally‐benign method for bioproduct separation and purification. In this study, a thin film composite (TFC) nanofiltration (NF) membrane was prepared and the pore size and charge of the polyamide layer were controlled by introducing iminodiacetic acid (IDA), a charged monoamine monomer, with piperazine (PIP) during interfacial polymerization (IP). The newly‐developed NF membrane was found to have a molecular weight cut‐off (MWCO) of 500 to 1350 Da, allowing the permeation of the fermentation product, while rejecting other higher molecular weight compounds. IDA addition in the aqueous amine solution during IP effectively engineered the MWCO values and pore sizes of TFC NF membranes for specific applications, such as separation of fermentation bioproducts. This study successfully showed that IDA reduced the diffusivity of PIP during IP, which negatively affected the polyamide formation and membrane performance. The optimal PIP:IDA concentration ratio was determined by MWCO and effective pore diameter for effective bioproduct separation and purification, which could not be performed by the current commercially‐available NF membranes.
A comprehensive review of recent advances in the biological activities of 1,2,4‐oxadiazoles
Authors: Hendawy Omnia M.
Published: April 2022

Nitrogen heterocycles play an essential role in medication development. The 1,2,4‐oxadiazole heterocycle has been extensively studied, yielding a large variety of molecules with varied biological functions. The 1,2,4‐oxadiazole shows bioisosteric equivalency with ester and amide moieties. In recent years, the 1,2,4‐oxadiazole nucleus has received a lot of attention in medicinal chemistry. It was thought to be a pharmacophore component in the production of biologically intriguing drugs. This review presents a comprehensive overview of the recent achievements in the biological activities of 1,2,4‐oxadiazoles as potential antimicrobial, anticancer, anti‐inflammatory, neuroprotective, and antidiabetic agents. The structure–activity relationship and mechanisms of action are also reviewed.
C2‐Symmetric Bissulfoximine‐Based Metal Complexes: Synthesis, Characterization and Their Electrocatalytic Activity in Oxygen Reduction Reaction
Authors: Junaid Qazi Mohammad , Kumar Singh Devesh , Ganesan Vellaichamy , Sabiah Shahulhameed
Published: April 2022

Sulfoximine‐based metal complexes have gained much interest in recent years owing to their promising properties in synthetic organic chemistry. These sulfoximines have been recently introduced in the field of organometallics. However, the coordination properties of pincer sulfoximine ligands and their metal complexes have not been reported. Here, a C2‐symmetric bissulfoximine‐based pincer ligand ((pyridine‐2,6‐diylbis(methylene))bis(azaneylylidene))bis(diphenyl‐λ6‐sulfanone), namely S‐P ligand and its metal [M(SP)2]2+ {M=Fe (SC‐1), Co (SC‐2), Ni (SC‐3), Cu (SC‐4)} complexes, were synthesized. The complexes were characterized by different spectroscopic techniques like UV‐Vis, IR, NMR, ESI‐MS, and single‐crystal XRD. Complexes SC‐1 and SC‐3 exhibited octahedral geometry irrespective of the metal center. The complexes were systematically explored for electrocatalytic oxygen reduction reaction (ORR) by immobilizing them on a glassy carbon electrode using Nafion. These complexes showed selective two‐electron catalytic reduction of O2 to H2O2 in which complex SC‐2 showed the highest selectivity (≈90%) and complex SC‐4 showed the highest onset potential (0.75 V).
Single‐Molecule Classification of Aspartic Acid and Leucine by Molecular Recognition through Hydrogen Bonding and Time‐Series Analysis
Authors: Ryu Jiho , Komoto Yuki , Ohshiro Takahito , Taniguchi Masateru
Published: April 2022

Amino acid detection/identification methods are important for understanding biological systems. In this study, we developed single‐molecule measurements for investigating quantum tunneling enhancement by chemical modification and carried out machine learning‐based time series analysis for developing accurate amino acid discrimination. We performed single‐molecule measurement of L‐aspartic acid (Asp) and L‐leucine (Leu) with a mercaptoacetic acid (MAA) chemical modified nano‐gap. The measured current was investigated by a machine learning‐based time series analysis method for accurate amino acid discrimination. Compared to measurements using a bare nano‐gap, it is found that MAA modification improves the difference in the conductance‐time profiles between Asp and Leu through the hydrogen bonding facilitated tunneling phenomena. It is also found that this method enables determination of relative concentration. even in the mixture of Asp and Leu. It improves selective analysis for amino acids and therefore would be applicable in medicine, diagnosis, and single‐molecule peptide sequencing.
Photoresponsive Small Molecule Inhibitors for the Remote Control of Enzyme Activity
Authors: Laczi Dóra , Johnstone Mark D. , Fleming Cassandra L.
Published: April 2022

The development of new and effective therapeutics is reliant on the ability to study the underlying mechanisms of potential drug targets in live cells and multicellular systems. A persistent challenge in many drug development programmes is poor selectivity, which can obscure the mechanisms involved and lead to poorly understood modes of action. In efforts to improve our understanding of these complex processes, small molecule inhibitors have been developed in which their OFF/ON therapeutic activity can be toggled using light. Photopharmacology is devoted to using light to modulate drugs. Herein, we highlight the recent progress made towards the development of light‐responsive small molecule inhibitors of selected enzymatic targets. Given the size of this field, literature from 2015 onwards has been reviewed.
Cribriform pattern disease over‐represented in pelvic lymph node metastases identified on 68GA PSMA‐PET/CT
Authors: Bolton Damien , Hong Anne , Papa Nathan , Perera Marlon , Kelly Brian , Duncan Catriona , Clouston David , Lawrentschuk Nathan
Published: April 2022

Objectives

To determine whether any specific histologic subtype of prostate cancer was preferentially represented in pelvic lymph node metastases identified on 68GA‐PSMA‐PET/CT.

Subjects and Methods

A consecutive series of 66 men with biochemical recurrent prostate cancer was evaluated with 68GA‐PSMA‐PET/CT. Where disease was confined to pelvic lymph nodes, patients were offered salvage extended pelvic lymph node dissection. Twenty patients ultimately proceeded to extended bilateral template pelvic lymph node dissection. Lymph node positivity and the histologic subtype of apparent cancer were assessed, as was PSA response to this intervention.

Results

Mean PSA at time of PSMA scanning for patients undergoing lymphadenectomy was 2.49 (n = 20, range 0.21–12.0). In 16 of 20 patients, there was evidence of metastatic cribriform pattern prostate cancer in excised nodes (100% cribriform pattern in 11/16). Only four of 20 patients had no evidence of this histologic subtype of disease. PSA response was not related to the presence or proportional amount of cribriform pattern disease identified.

Conclusions

Cribriform pattern adenocarcinoma appears to be the histologic subtype preferentially identified in pelvic lymph nodes on 68GA‐PSMA‐PET/CT. The use of PSMA‐PET may be particularly valuable in staging of primary or biochemically recurrent prostate cancer in patients with cribriform pattern disease detected on initial biopsy or radical prostatectomy. Further research is required to further confirm the observed association.
Interaction between caffeic acid phenethyl ester and protease: monitoring by spectroscopic and molecular docking approaches
Authors: Nai Xiao , Chen Yanrong , Zhang Qian , Hao Shengyu , Xuan Hongzhuan , Liu Jie
Published: April 2022

The interaction of one anticancer drug (caffeic acid phenethyl ester; CAPE) with three proteases (trypsin, pepsin and α‐chymotrypsin) has been investigated with multispectral methods and molecular docking. As an active components in propolis, the findings are of great benefit to metabolism, design, and structural modification of drugs. The results show that CAPE has an obvious ability to quench the trypsin, pepsin, or α‐chymotrypsin fluorescence mainly through a static quenching procedure. Trypsin has the largest binding affinity to CAPE, and α‐chymotrypsin has the smallest binding affinity to CAPE. The data obtained from thermodynamic parameters and molecular docking prove that the spontaneously interaction between CAPE and each protease is mainly due to a combination of van der Waals (vdW) force and hydrogen bond (H‐bond), controlled by an enthalpy‐driven process. The binding force, strength, position, and the number of H‐bond are further obtained from the results of molecular docking. Through ultraviolet spectroscopy, dynamic light scattering and circular dichroism experiments, the change in the protease secondary structure induced by CAPE was observed. Additionally, the addition of protease had a positive effect on the antioxidative activity of CAPE, and α‐chymotrypsin has the greatest effect on the removal of 2,2‐diphenyl‐1‐picrylhydrazyl free radicals by CAPE.
Systems metabolic engineering of Streptomyces venezuelae for the enhanced production of pikromycin
Authors: Cho Min Kyung , Lee Byung Tae , Kim Hyun Uk , Oh Min‐Kyu
Published: April 2022

Pikromycin is an important precursor of drugs, for example, erythromycin. Hence, systems metabolic engineering for the enhanced pikromycin production can contribute to the development of pikromycin‐related drugs. In this study, metabolic genes in Streptomyces venezuelae were systematically engineered for enhanced pikromycin production. For this, a genome‐scale metabolic model of S. venezuelae was reconstructed and simulated, which led to the selection of 11 metabolic gene targets. These metabolic genes, including four overexpression targets and seven knockdown targets, were individually engineered first. Next, two overexpression targets and two knockdown targets were selected based on the 11 strains' production performances to engineer two to four of these genes together for the potential synergistic effects on the pikromycin production. As a result, the NM1 strain with AQF52_RS24510 (methenyltetrahydrofolate cyclohydrolase/methylenetetrahydrofolate dehydrogenase) overexpression and AQF52_RS30320 (sulfite reductase) knockdown showed the best production performance among all the 22 strains constructed in this study. Fed‐batch fermentation of the NM1 strain produced 295.25 mg/L of pikromycin, by far the best production titer using the native producer S. venezuelae, to the best of our knowledge. The systems metabolic engineering strategy demonstrated herein can also be applied to the overproduction of other secondary metabolites using S. venezuelae.
Child sexual exploitation material offenders, one‐size‐fits‐all for? Exploring tailored clinical dimensions based on cognitive and behavioural criminogenic factors
Authors: Paquette Sarah , Chopin Julien , Fortin Francis
Published: April 2022

Background

Interventions for individuals involved in sexual offending behaviours are likely to be more effective if adapted to focus on their specific characteristics, suggesting that men who engage in sexual offences against children over the Internet should be treated differently from those who have actual physical contact against children.

Aims

The goal of this study is to explore possible associations between the criminogenic cognitions and behaviours of men using online child sexual exploitation material (CSEM) and variables relevant to intervention. We hypothesised that antisocial tendencies, sexual, emotional and relational problems and self‐regulation problems, as well as cognitive distortions would be associated with CSEM use.

Method

Ninety‐eight men who had been convicted of at least one online CSEM‐related offence, but no child contact sexual offences, at any time between 2001 and 2020 were recruited in the province of Quebec (Canada). Cases were reviewed to identify cognitive and behavioural criminogenic factors according to a coding sheet developed after reference to prior literature. Variables were extracted from official criminal records, sexological and psychological reports, as well as investigative and forensic reports and interviews. Exploratory factor analysis was carried out to identify potentially relevant dimensions.

Results

Analysis confirmed five distinct factors which, together, accounted for 60% of the variance:dissocial traits, dysfunctional intimacy, passive alienation (internalised sense of alienation),normless alienation (social norms experienced as alien)andcoping with threat.

Conclusion

Because online CSEM‐related offenders present heterogeneous risks and needs, a ‘one‐size‐fits‐all’ intervention is unlikely to be optimal for most of them. Our findings suggest a way of classifying risks and needs to facilitate more focused interventions. Future research should evaluate the relative effectiveness of general interventions compared to those tailored towards the dimensions of risks and needs identified in this study.
Novel method for left ventricular unloading utilizing percutaneous pulmonary artery drainage in cardiorespiratory failure due to COVID‐19 infection
Authors: Kumar Kris , Coonse Kendra , Zakhary Bishoy , Cigarroa Joaquin E.
Published: April 2022

Left ventricular (LV) unloading is an important concept in patients undergoing peripheral venoarterial extracorporeal membrane oxygenation (VA‐ECMO). We present a case of a 32‐year‐old male in acute cardiorespiratory collapse due to coronavirus disease (COVID‐19) who underwent VA‐ECMO cannulation in the setting of cardiogenic shock and acute respiratory distress syndrome. Due to inability to utilize percutaneous LV assist device (pLVAD) for LV unloading due to small end diastolic dimension, alternative strategies were explored. A traditionally utilized right ventricular support device, the ProTek Duo (TandemLife, Pittsburgh, PA), was utilized to drain the pulmonary artery, leading to improvement in parameters for cardiogenic shock. To our knowledge, this is the first case in which a ProTek Duo has been utilized in conjunction with VA‐ECMO to provide LV unloading in support of a patient in cardiogenic shock. This method can be employed in future challenging situations where pLVAD is not feasible.
Significance of wheat milling operations on the distribution of Escherichia coli bacterium into milling fractions
Authors: Rivera Jared , Pulivarthi Manoj K. , Shivaprasad DP , Phebus Randall , Aldrich Charles G. , Siliveru Kaliramesh
Published: April 2022

Background and Objectives

Cross‐contamination of pathogens is a common cause of food recalls. The objectives of this study were to quantify the amount of Escherichia coli transferred during wheat milling and to model the E. coli concentration in wheat flour fractions during milling.

Findings

Higher (p ≤ .05) E. coli counts were recovered in the nonflour mill fractions (1.9–4.5 log CFU/g) during the inoculated wheat milling run. The E. coli counts in flour fractions increased with more amounts (kg) of inoculated wheat milled. During the noninoculated mill run, E. coli counts decreased as more wheat was milled. Greater E. coli contamination was observed in the nonflour fractions (1.8–3.4 log CFU/g). The fitted models were significant (p ≤ .05) and had acceptable fit (R2 = 0.40–0.85; SE = 0.16–0.42).

Conclusion

The findings indicate that E. coli contamination from wheat kernel could transfer into the flour at a lower concentration relative to nonflour fractions and that continuous milling of contaminated wheat increased flour E. coli counts.

Significance and Novelty

The results from this study may help development of mitigation strategies for pathogen contamination during milling and could be used for risk assessment analysis in wheat flour products.
Efficiently handling high‐dimensional data from multifactorial designs with unequal group sizes using Rebalanced ASCA (RASCA)
Authors: de Figueiredo Miguel , Giannoukos Stamatios , Rudaz Serge , Zenobi Renato , Boccard Julien
Published: April 2022

A novel chemometric approach is proposed to analyze high‐dimensional data from unbalanced designs of experiments. It combines a rebalancing strategy based on averages with the ASCA method under the name Rebalanced ASCA (RASCA). The ability of RASCA to handle unbalanced designs was compared with standard ASCA, as well as state‐of‐the‐art methods, such as ASCA+ and WE‐ASCA. For that purpose, a controlled framework was designed to provide a systematic comparison of the various approaches. It included two real datasets obtained from initially balanced designs, which were gradually unbalanced by removing observations belonging to specific combinations of factor levels. The results illustrate that all methods considered led to identical solutions when the initial balanced design was kept. Nevertheless, increasing differences appeared when the design was gradually unbalanced. The proposed benchmark showed that RASCA and ASCA+ provided overall similar results for all effects with high agreement with the balanced solutions in comparison to classical ASCA and WE‐ASCA. RASCA was found to be a suitable chemometric tool to tackle unbalanced designs by ensuring unbiased parameter estimators with the added benefit of producing rigorously orthogonal effect matrices, thus facilitating interpretation.
An examination of turfgrass species use on golf course putting greens
Authors: Brosnan James T. , Peake Jason B. , Schwartz Brian M.
Published: April 2022

Core Ideas

Golf course superintendents were surveyed to create maps delineating turfgrass species use on putting greens.

Creeping bentgrass was used on putting greens across the vast majority of the continental United States in 2021.

This dataset provides a baseline for future studies examining changes in golf course species use on putting greens.