bluuebunny/crossref_metadata_2025 huggingface dataset:
Sound-pressure measurements in the cochlear vestibule of human-cadaver ears
Authors: Puria Sunil , Peake William T. , Rosowski John J.
Published: July 2002

The middle-ear pressure gain for the 50-Hz to 12-kHz range was determined from the ratio of sound pressures measured in the vestibule and the ear canal of four human-cadaver ears. The magnitude of the middle-ear pressure gain is 20 dB for frequencies between 500 Hz and 2 kHz. Above 4 kHz, the gain changes as a function of frequency at a rate of approximately −8 dB/octave and below 400 Hz at 4 dB/octave. The standard error of the mean magnitude across the four ears is typically less than 3 dB. The phase angle of the pressure gain also changes with frequency. Interruption of the ossicular chain decreases the vestibule pressure by at least 20 dB. It is shown that air bubbles in the inner ear can diminish the vestibule pressure; procedures are used to remove bubbles. From these pressure measurements and previous measurements of stapes motion, the frequency dependence of behavioral thresholds for tones was tested to discover whether it corresponds to the constancy of a physiological variable at the cochlear input. Among pressure, power, or stapes-motion measures, the vestibule pressure is most nearly constant with frequency at the behavioral “minimum audible pressure.”
Sound transmission through elastic porous wedges and foam layers having spatially graded properties
Authors: Kang Yeon June , Bolton J. Stuart
Published: July 2002

Recently a finite element implementation of Biot’s elastic porous material theory has been developed for the purpose of modeling and optimizing foam noise control treatments [Y. J. Kang and J. S. Bolton, J. Acoust. Soc. Am. 98, 635–643 (1995)]. That finite element formulation was used in the work reported here to study normal incidence sound transmission through a foam wedge placed in a hard-walled duct. It was found that in some frequency bands the transmission loss of the wedge was significantly higher than that of a plane foam layer of the same volume. That increase in transmission loss was found to result from the conversion, within the foam, of the incident plane wave into a higher-order symmetric mode: that mode was found not to radiate efficiently from the rear surface of the foam wedge. It has also been found that the same increase in transmission loss can be achieved by varying the pore tortuosity across the width (not the depth) of a plane foam layer. Thus it is suggested that lining materials having spatially graded properties may be used to enhance the transmission loss of noise control treatments under some circumstances.
Mirages in shallow water matched field processing
Authors: D’Spain G. L. , Murray J. J. , Hodgkiss W. S. , Booth N. O. , Schey P. W.
Published: July 2002

Broadband matched field processing (MFP)-derived estimates of 3D source location using data from hydrophone line arrays deployed in various geometries, i.e., vertical, horizontal, and tilted 45° from vertical, are presented in this paper. These data were collected in two shallow water (100–200 m) experiments off the coast of San Diego. Results show that estimates of source range and depth remain surprisingly coherent in the presence of large mismatch in bathymetry, but are offset from the true position by as much as 100%. The offsets are independent of array geometry. In contrast, for estimates of source azimuth, bathymetry mismatch typically causes a degradation in MFP correlation rather than an appreciable offset. However, errors in the assumed tilt from vertical of an array can lead to large offsets in the estimated source azimuth, particularly as the nominal angle of the array from vertical becomes smaller. Predictions from a simple analytical model based on adiabatic normal modes in ideal waveguides provide good fits to the broadband MFP results.
Segmental and syllabic representations in the perception of speech by young infants
Authors: Eimas Peter D.
Published: July 2002

In a series of four experiments, the ability of 3- to 4-month-old infants to form categorical representations to syllable-initial consonants in monosyllabic stimuli (experiments 1 and 2) and to initial and final syllables in bisyllabic stimuli (experiments 3 and 4, respectively) was investigated. Experiment 1 yielded no evidence of categorical representations for the initial consonant. However, the results indicated that the four or six stimuli presented during the initial phase of familiarization had been remembered. The results of experiment 2, which employed a less stringent familiarization criterion, replicated the findings of experiment 1, although there was some evidence for categorization for infants whose familiarization performance more closely matched the weaker criterion. In experiment 3, there was strong evidence for a categorical representation of the initial syllable of bisyllabic stimuli for infants experiencing six familiar stimuli. In experiment 4, there was less robust evidence of categorization of the final syllable of bisyllabic stimuli, but again only when six familiar stimuli were experienced. The results were discussed in terms of the earliest representation of speech being syllables that could be modified by the rhythmic nature of the infant’s native language.
The merge model: Speech perception is bottom-up
Authors: Norris Dennis
Published: July 2002

Does feedback from the lexicon influence the processing of phonemic or phonetic information in normal speech perception? Arguments are presented that top-down feedback from the lexicon is no value in spoken word recognition. In fact, top-down feedback is as likely to be harmful as helpful. Consistent with this analysis, recent studies of phoneme identification and phonetic categorisation have generated data that are incompatible with interactive models like trace [McClelland and Elman (1986)] which employ top-down feedback. However, other data rule out bottom-up models like the Race model of Cutler and Norris (1979). A new, bottom-up model is presented, the Merge model. Merge can simulate these problematic results by merging information from both lexical and sublexical analyses while maintaining a strictly feed-forward data path for spoken word recognition. Merge builds on the principles of lexical competition and bottom-up processing incorporated in the Shortlist model [Norris (1994)].
Subharmonic backscattering from ultrasound contrast agents
Authors: Shankar P. M. , Krishna P. D. , Newhouse V. L.
Published: July 2002

The ultrasonic contrast of blood in tissue, which is needed for ultrasonic estimation of tissue perfusion, can be increased by injecting the blood with bubbles or hollow microspheres. It has been shown that an even greater improvement in contrast can be obtained by using the subharmonic generated by irradiated microspheres. By obtaining analytical solutions to the modified RPNNP equation for a coated microbubble, the relationship between the physical parameters of the encapsulated bubble and the threshold pressure is established. The observed increase in the resonance frequency of a coated microsphere is explained by introducing the concept of “acoustic radius” of the encapsulated bubble. It is predicted that subharmonic generation in contrast agents requires a threshold insonifying pressure, and should be a minimum when microspheres are insonated at twice their resonance frequency. Experiments confirm the existence of this optimum incident frequency and of a reasonably low threshold pressure for the generation of the subharmonic. The existence of the low threshold pressures for subharmonic generation in contrast agents may prove to be very valuable in ultrasonic contrast imaging.
An acoustical helicoidal wave transducer with applications for the alignment of ultrasonic and underwater systems
Authors: Hefner Brian T. , Marston Philip L.
Published: July 2002

A simple four-panel transducer capable of producing a beam with a screw dislocation along its axis was constructed and evaluated. A screw dislocation in a wavefront is characterized by a phase dependence about the dislocation axis that varies as exp(−imφ), where m is an integer and φ is the angle about the axis. At the axis, the phase is indeterminate and as a result there is a corresponding null in the pressure magnitude. The screw dislocation in the transducer beam is along the beam axis and is found to exist in both the far- and near-fields of the transducer. This null then clearly indicates the axis of the beam at all distances and has the potential to be used as an aid in the alignment of objects in sonar experiments or other similar applications. The helicoidal wave is also shown to possess axial angular momentum. A related transducer was summarized previously [J. Acoust. Soc. Am. 103, 2971 (1998)] and is also discussed here for the purposes of comparison.
Neurophysiologic correlates of cross-language phonetic perception
Authors: Sharma Anu , Dorman Michael F.
Published: July 2002

This study examined neurophysiologic correlates of the perception of native and nonnative phonetic categories. Behavioral and electrophysiologic responses were obtained from Hindi and English listeners in response to a stimulus continuum of naturally produced, bilabial CV stimuli that differed in VOT from −90 to 0 ms. These speech sounds constitute phonemically relevant categories in Hindi but not in English. As expected, the native Hindi listeners identified the stimuli as belonging to two distinct phonetic categories (/ba/ and /pa/) and were easily able to discriminate a stimulus pair across these categories. On the other hand, English listeners discriminated the same stimulus pair at a chance level. In the electrophysiologic experiment N1 and MMN cortical evoked potentials (considered neurophysiologic indices of stimulus processing) were measured. The changes in N1 latency which reflected the duration of pre-voicing across the stimulus continuum were not significantly different for Hindi and English listeners. On the other hand, in response to the /ba/–/pa/ stimulus contrast, a robust MMN was seen only in Hindi listeners and not in English listeners. These results suggest that neurophysiologic levels of stimulus processing reflected by the MMN and N1 are differentially altered by linguistic experience.
Theory of Stratified Bicomponent Flow of Polymer Melts. I. Equilibrium Newtonian Tube Flow
Authors: Everage A. E.
Published: July 2002

A theoretical and experimental study of the equilibrium interface configuration in stratified bicomponent tube flow of polymer melts is presented. In the theoretical analysis, the principle of minimum viscous dissipation is used to determine the energetically preferred interface configuration for the case of stratified flow of Newtonian fluids of differing viscosity. In the experimental analysis, it is demonstrated that both a nylon-nylon and a xylene-sugar water solution system attain the minimum viscous dissipation interface configuration under equilibrium conditions.
Theory of Stratified Bicomponent Flow of Polymer Melts. II. Interface Motion in Transient Flow
Authors: Everage A. E.
Published: July 2002

An approximate theoretical analysis of transient bicomponent flow and interface motion in the entrance region of infinite parallel plates is presented, and an estimate of the entry length required to attain equilibrium flow is obtained. The theoretical predictions are compared with experimental measurements of interface configuration and extrudate bending in the bicomponent tube flow of a nylon/nylon system. The results indicate that interface motion takes place at two distinct rates in the tube flow case. Initially a very rapid interface movement occurs which is qualitatively described by the theoretical parallel plate analysis. This is followed by a very slowly occurring interface curvature which has no apparent counterpart in the parallel plate case considered here.
Solution rheology of a hydrophobically modified alkali-soluble associative polymer
Authors: English Robert J. , Gulati Harpreet S. , Jenkins Richard D. , Khan Saad A.
Published: July 2002

Rheological and photophysical data are presented for a hydrophobically modified alkali-soluble copolymer, of a constitution similar to materials currently employed as rheology modifiers in water-borne coatings. The copolymer comprises a polyelectrolyte backbone bearing ethoxylate side chains capped with complex alkylaryl groups of a high molar volume. In aqueous alkaline media, the hydrophobes associate dynamically, the topology of the network so formed being dependent on the polymer concentration. Photophysical studies, employing pyrene as a hydrophobic fluorescent probe, indicate the presence of hydrophobic associations. At concentrations below the coil overlap concentration, c*, these associations are predominantly intramolecular. At higher polymer concentrations, intermolecular interactions become more probable. This change in network topology is in qualitative agreement with previous theoretical considerations of associative polymer systems and is reflected in an unusually high concentration dependence of the zero shear viscosity, with η0∼c8. Evidence for shear-induced structuring in steady shear, large amplitude oscillatory shear, and parallel superposed steady and dynamic shear is presented. Such structuring is more pronounced at lower polymer concentrations, consistent with the formation of intermolecular associations at the expense of intramolecular. In contrast to the simple linear telechelic associative polymers considered in a number of previous studies, the network dynamics of the polymer are no longer represented by a single characteristic time. This deviation from a classical Maxwellian response in oscillatory shear is interpreted as a broadening of the relaxation spectrum, arising from the coexistence of both hydrophobic associations and topological entanglements. Mechanistically, stress relaxation is better envisaged in terms of “hindered reptation” [Liebler et al. (1991)] of the chains, rather than Rouse-like behavior moderated purely by the hydrophobe disengagement rate [Annable et al. (1993)].
The yield stress of concentrated flocculated suspensions of size distributed particles
Authors: Zhou Zhongwu , Solomon Michael J. , Scales Peter J. , Boger D. V.
Published: July 2002

An investigation of shear yield stress is made on well-characterized alumina suspensions of different distributed particle sizes at the vicinity of the particle isoelectric point (IEP) across a wide range of volume fractions. Experimental results are compared with recently developed models [; ] and structural effects on the yield stress are examined. The models predict the magnitude order of the yield stress below a volume fraction of approximately 0.42, suggesting that interparticle forces play a dominant role in determining the network strength in this concentration region. Deviations between experimental results and theoretical predictions are explained in terms of structural effects being controlled by a competition between weak particle–particle linkages and geometric resistance on the network strength. At higher volume fraction, the effect of geometric resistance on the deformation of suspensions becomes more pronounced. A number of models for the yield stress of size distributed suspensions are then proposed. Results suggest that the effect of polydispersity of particles on the yield stress of suspensions can be well characterized by a surface area average diameter and the broad size distributed suspension exhibits a higher yield stress than the narrow size distributed suspension of the same volume average diameter.
No rise in methadone OD deaths with new take‐home rules
Authors: Knopf Alison
Published: July 2022

In another step toward increasing take‐home methadone for patients in opioid treatment programs (OTPs), the National Institute on Drug Abuse (NIDA) has found that the percentage of methadone‐involved overdose deaths relative to all drug overdose deaths declined from January 2019 to August 2021. The study showing this data was published last week in JAMA Psychiatry and was a collaborative effort of NIDA and the Centers for Disease Control and Prevention (CDC).
3D Hydrogel Evaporator with Vertical Radiant Vessels Breaking the Trade‐Off between Thermal Localization and Salt Resistance for Solar Desalination of High‐Salinity
Authors: Liu Xinghang , Chen Feixiang , Li Yuankai , Jiang Hanjin , Mishra Debesh Devadutta , Yu Fang , Chen Zihe , Hu Chaoquan , Chen Yun , Qu Liangti , Zheng Weitao
Published: July 2022

Delivering sufficient water to the evaporation surface/interface is one of the most widely adopted strategies to overcome salt accumulation in solar‐driven interfacial desalination. However, water transport and heat conduction loss are positively correlated, resulting in the trade‐off between thermal localization and salt resistance. Herein, a 3D hydrogel evaporator with vertical radiant vessels is prepared to surmount the long‐standing trade‐off, thereby achieving high‐rate and stable solar desalination of high‐salinity. Experiments and numerical simulations reveal that the unique hierarchical structure, which consists of a large vertical vessel channel, radiant vessels, and porous vessel walls, facilitates strong self‐salt‐discharge and low longitudinal thermal conductivity. With the structure employed, a groundbreaking comprehensive performance, under one sun illumination, of evaporation rate as high as 3.53 kg m−2 h−1, salinity of 20 wt%, and a continuous 8 h evaporation is achieved, which thought to be the best reported result from a salt‐free system. This work showcases the preparation method of a novel hierarchical microstructure, and also provides pivotal insights into the design of next‐generation solar evaporators of high‐efficiency and salt tolerance.
A Chiral Dual‐Core Organoboron Structure Realizes Dual‐Channel Enhanced Ultrapure Blue Emission and Highly Efficient Circularly Polarized Electroluminescence
Authors: Yan Zhi‐Ping , Yuan Li , Zhang Yuan , Mao Meng‐Xi , Liao Xiang‐Ji , Ni Hua‐Xiu , Wang Zhi‐Heng , An Zhongfu , Zheng You‐Xuan , Zuo Jing‐Lin
Published: July 2022

The realization of luminescent materials with narrowband and circularly polarized luminescence (CPL) is of great significance for the development of future optical and photonic devices. Herein, through a steric‐hindrance‐assisted dual‐core strategy, two pairs of chiral dual‐core multiple resonance thermally activated delayed fluorescence (MR‐TADF) materials (R/S‐DOBN and R/S‐DOBNT) are directly constructed by the bonding of two organoboron MR‐TADF monocores (SOBN and SOBNT) with carbazole/3,6‐di‐tert‐butyl‐9H‐carbazole and phenol derivative as donors, realizing obvious CPL and narrowband emissions. Furthermore, the dual‐core effect in the prepared R/S‐DOBN and R/S‐DOBNT increases the transition oscillator strength two times more than that of a monocore structure, while maintaining the ultrapure blue emissions peaking at 453 and 459 nm with a narrower full‐width at half‐maximum of 21 nm through reorganization energy reduction. The circularly polarized organic light‐emitting diodes based on the enantiomers exhibit ultrapure blue emission with Commission Internationale de L'Eclairage (CIE) coordinates of (0.14, 0.10) and (0.13, 0.12), high maximum external quantum efficiencies of 23.9% and 25.6%, and obvious circularly polarized electroluminescence with dissymmetry factors (|gEL|) ≈ 10−3.
Mechano‐Dynamic Analysis of the Bactericidal Activity of Bioinspired Moth‐Eye Nanopatterned Surfaces
Authors: Alameda María Teresa , Osorio Manuel Rodríguez , Pedraz Patricia , Rodríguez Isabel
Published: July 2022

In recent years, the understanding of the bactericidal mechanisms of natural surfaces has received great attention to unravel their design principles for the development of next‐generation mechano‐bactericidal surfaces. Due to the difficulty in characterizing the bacteria–nanostructure interface, many aspects of the physical interaction between bacteria and the surface, and the underlying bactericidal mechanisms, remain unclear. This study focuses on evaluating the dynamics of the mechano‐bactericidal process in the case of the moth‐eye bioinspired topography in relation to the bacteria strain and mechanical characteristics of the surface. The bacteria–nanostructure interface is examined by measuring the deformations inflicted by the nanotopography on the bacterial wall upon attachment using two techniques, namely atomic force microscopy and stereometric analysis of scanning electron microscopy images. All data match well and are in accordance with the expected bacteria mechanical deformation calculated by finite element modeling. This represents a practical methodology to measure bacterial deformations inflicted by nanotopography. The methodology can be implemented to any other bacteria strain or bactericidal topography to verify the degree of mechanical stress and bactericidal efficacy related to the topography and surface stiffness and may serve as a design basis for the fabrication of effective antibacterial surfaces.
Dual‐Atomic Catalysts Deduced from d−π Conjugated Metal−Organic Frameworks for Efficient Oxygen Evolution Reaction
Authors: Liu Jiameng , Zhao Shuangrun , Wang Changbao , Hu Bin , He Linghao , Wang Minghua , Zhang Zhihong , Du Miao
Published: July 2022

A series of semiconductive cobalt‐based metal–organic framework (MOFs) are prepared in this work using 2,3,6,7,10,11‐hexaiminotriphenylene (HATP) as ligand and diverse metal ions as the second coordination centers (M = Mn, Ni, and Zn) (denoted as CoxM3‐x(HITP)2 MOFs). The series of bimetallic CoxM3‐x(HITP)2 MOFs exhibit ultrathin graphene‐like nanostructure, highly d–π conjugated network, large specific surface areas, and diverse metal coordination modes. Density functional theory calculations reveal the unique synergism between M (M = Mn, Ni, and Zn) and Co nodes, in which adjacent layers of M atoms can efficiently modulate the electron densities of Co atoms in Co3(HITP)2. As compared, CoxZn3‐x(HITP)2 MOF possesses substantially enhanced electron density around the Co atoms, dual‐metal atomic sites, and rich metal coordination modes, and exhibits superior electrochemical activity. Among them, CoxZn3‐x(HITP)2 displays the outperformed electrocatalytic performances of the oxygen evolution reaction (OER). Particularly, CoxZn3‐x(HITP)2 shows the lowest overpotential of 210 mV and good long‐term stability. This work develops an efficient strategy for designing and regulating atomically dispersed catalysts in conductive MOFs toward clean energy applications.
An Internet‐of‐Disease System for COVID‐19 Testing Using Saliva by an AI‐Controlled Microfluidic ELISA Device
Authors: Bhuiyan Nabil Hossain , Uddin Md. Jalal , Lee Joowon , Hong Jun Hyeok , Shim Joon Sub
Published: July 2022

Throughout coronavirus disease (COVID‐19) outbreaks, the centers for disease control and prevention (CDCP) of a country require monitoring of particular territories to provide public health guidance. In this work, the Internet of Diseases (IoD) is suggested for continuous real‐time monitoring of infectious diseases for public health. Because converging information and communication technologies (ICTs) with point‐of‐care (POC) devices to enable the IoD for continuous real‐time health monitoring and processing of clinical records are crucial, an IoD platform associating a lab‐on‐a‐chip (LOC) device to diagnose severe acute respiratory syndrome‐coronavirus‐2 (SARS‐CoV‐2) from oropharyngeal saliva samples have been developed and uploaded the resulted diagnostic data into a cloud‐based system to be connected with CDCP. Moreover, a choropleth IoD map to visualize provincial infection rate is proposed along with the IoD platform. The developed platform is applied for the quantification of SARS‐CoV‐2 N‐protein antigen with a LOD as low as 0.013 ng mL−1 and the infection rate of various provinces is projected with the IoD map successfully. Thus, the proposed IoD system has the potential to become an imperative tool for the disease control and prevention centers to restrain COVID‐19 outbreaks by identifying the severity of particular regions.
Atomically Thin Antimony‐Doped Indium Oxide Nanosheets for Optoelectronics
Authors: Nguyen Chung Kim , Low Mei Xian , Zavabeti Ali , Murdoch Billy J. , Guo Xiangyang , Aukarasereenont Patjaree , Mazumder Aishani , Dubey Aditya , Jannat Azmira , Rahman Md. Ataur , Chiang Ken , Truong Vi Khanh , Bao Lei , McConville Chris F. , Walia Sumeet , Daeneke Torben , Syed Nitu
Published: July 2022

Wide bandgap semiconducting oxides are emerging as potential 2D materials for transparent electronics and optoelectronics. This fuels the quest for discovering new 2D metal oxides with ultrahigh transparency and high mobility. While the former can be achieved by reducing the thickness of oxide films to only a few nanometers, the latter is more commonly realized by intentional doping. This article reports a one‐step synthesis of few‐unit‐cell‐thick and laterally large antimony‐doped indium oxide (IAO). The doping process occurs spontaneously when the oxide is grown on the surface of a molten Sb–In alloy and 2D IAO nanosheets can be easily printed onto desired substrates. With thicknesses at the atomic scale, these materials exhibit excellent transparency exceeding 98% across the visible and near‐infrared range. Field‐effect transistors based on low‐doped IAO nanosheets reveal a high electron mobility of ≈40 cm2 V−1 s−1. Additionally, a notable photoresponse is observed in 2D IAO‐based photodetectors under ultraviolet (UV) radiation. Photoresponsivities of low‐doped and highly doped IAO at a wavelength of 285 nm are found to be 1.2 × 103 and 0.7 × 103 A W−1, respectively, identifying these materials as promising candidates for the fabrication of high‐performance optoelectronics in the UV region.
Numerical Modeling of the Collective Behavior of Scarab Beetles Transporting Dung Balls and Competing for Them on Complex Terrain
Authors: Filippov Alexander E. , Gorb Stanislav N.
Published: July 2022

To avoid competition for the same food resource, scarab beetles form dung ball and roll it away from the dung pile. They randomly choose direction which they strictly follow. According to previous results, the dynamic behavior of the beetle rolling dung ball is essentially defined by the complexity of the surface. The typical real surface is combined from a universal scale invariant (fractal) component and another component having a well‐defined characteristic scale. If the transported dung ball has a size comparable with the dimensions of peculiarities of the surface, it strongly influences the motion trajectory. On the flat terrain and at the absence of competitors, beetles manage to roll the ball along a nearly perfect straight path. However, even if the beetle is alone, on a more realistic terrain, the motion is more complex. The motion becomes much more complicated in the realistic situation, when the beetles complete for the balls. In this study, a numerical model is developed which combines 1) attraction of the beetles to the dung, (2) production of the balls of different sizes depending on the size/fitness of the animals, 3) the ball transportation on complex terrains, and 4) the competition between the beetles for already existing balls. A strong correlation between typical radius of the ball and the size of the relief minimums and the results of the competitions, as well as possible optimal strategies of the beetle behavior are found.
Designing Ultrafast Cooling Rate for Room Temperature Electrocaloric Effects by Phase‐Field Simulations
Authors: Shao Cancan , Shi Xiaoming , Wang Jing , Xu Jiwen , Huang Houbing
Published: July 2022

Due to miniaturization and environmental friendliness, the electrocaloric effect is expected to be applied to refrigerate electronic chips and microdevices. Unlike the conventional electrocaloric effect that focuses on the temperature change, the ultrafast cooling rate is crucial to heat transport in future device units. In this work, controlling the duration of ultrafast electric field pulse on a nanosecond scale (the frequency ∼ GHz), the instant electrocaloric effect is realized in BaTiO3 and Ba(1−x)SrxTiO3 systems based on the modified phase‐field method. A significant ultrafast cooling rate of 108 K s−1 can be achieved due to the application of ultrafast electric field pulse within nanoseconds, which proved to be more efficient than the constant electric field. Furthermore, multiple electric field pulses are designed to realize the cyclic ultrafast cooling. This study provides the fundamental theoretical guidance for ultrafast cooling in solid‐state refrigeration.
Beyond Janus Geometry: Characterization of Flow Fields around Nonspherical Photocatalytic Microswimmers
Authors: Heckel Sandra , Bilsing Clemens , Wittmann Martin , Gemming Thomas , Büttner Lars , Czarske Jürgen , Simmchen Juliane
Published: July 2022

Catalytic microswimmers that move by a phoretic mechanism in response to a self‐induced chemical gradient are often obtained by the design of spherical janus microparticles, which suffer from multi‐step fabrication and low yields. Approaches that circumvent laborious multi‐step fabrication include the exploitation of the possibility of nonuniform catalytic activity along the surface of irregular particle shapes, local excitation or intrinsic asymmetry. Unfortunately, the effects on the generation of motion remain poorly understood. In this work, single crystalline BiVO4 microswimmers are presented that rely on a strict inherent asymmetry of charge‐carrier distribution under illumination. The origin of the asymmetrical flow pattern is elucidated because of the high spatial resolution of measured flow fields around pinned BiVO4 colloids. As a result the flow from oxidative to reductive particle sides is confirmed. Distribution of oxidation and reduction reactions suggests a dominant self‐electrophoretic motion mechanism with a source quadrupole as the origin of the induced flows. It is shown that the symmetry of the flow fields is broken by self‐shadowing of the particles and synthetic surface defects that impact the photocatalytic activity of the microswimmers. The results demonstrate the complexity of symmetry breaking in nonspherical microswimmers and emphasize the role of self‐shadowing for photocatalytic microswimmers. The findings are leading the way toward understanding of propulsion mechanisms of phoretic colloids of various shapes.
Microneedle Patches with O2 Propellant for Deeply and Fast Delivering Photosensitizers: Towards Improved Photodynamic Therapy
Authors: Liu Pei , Fu Yangxue , Wei Fulong , Ma Teng , Ren Jingli , Xie Zhanjun , Wang Shanzheng , Zhu Jinjin , Zhang Lianbin , Tao Juan , Zhu Jintao
Published: July 2022

Photodynamic therapy (PDT) is an emerging technique for treating tumors. Especially, topical administration of photosensitizers (PSs) is more favorable for superficial tumor treatments with low systematic phototoxicity. Yet, ineffective migration of PSs to targeted tumor tissues and rapid consumption of O2 during PDT greatly limit their effects. Herein, PS‐loaded microneedle (MN) patches with O2 propellant for a deeper and faster transdermal delivery of PS and improved PDT by embedding sodium percarbonate (SPC) into dissolving poly(vinyl pyrrolidone) MNs are presented. It is shown that SPC in the MNs can react with surrounding fluid to generate gaseous oxygen bubbles, forming vigorous fluid flows and thus greatly enhancing PS of chlorin e6 (Ce6) penetration in both hydrogel models and skin tissues. Reactive oxygen species (ROS) in hypoxic breast cancer cells (4T1 cells) are greatly increased by rapid penetration of PS and relief of hypoxia in vitro, and Ce6‐loaded SPC MNs show an excellent cell‐killing effect. Moreover, lower tumor growth rate and tumor mass after a 20‐d treatment in tumor‐bearing mice model verify the improved PDT in gaseous oxygen‐droved delivery of PS. This study demonstrates a facile yet effective route of MN delivery of PSs for improved PDT in hypoxic tumor treatment.
Polydopamine‐Based All Solid‐State Flexible Organic Neuromorphic Devices for Access Device‐Free Artificial Neural Networks
Authors: Kazemzadeh Setareh , Dodsworth Lloyd , Pereira Inês Figueiredo , van de Burgt Yoeri
Published: July 2022

Recent developments in organic neuromorphic devices and biohybrid interfaces are promising examples that show potential to improve implantable devices toward organic adaptive brain‐machine interfaces. However, fully integrated neuromorphic arrays still require relatively complex circuitry that includes multiple access devices to ensure synaptic weight stability and prevent sneak paths. Here, it is shown that polydopamine (PDA), the byproduct of dopamine autoxidation, promotes proton conductivity and can serve as a solid‐state electrolyte. Slow kinetics and high energy barriers of the PDA solid electrolyte prevent loss of conductance state for the device with a three‐terminal configuration without an access device, while partial dedoping of the conductive polymer channel by PDA simultaneously increases its stability in ambient environments. Fabricating the neuromorphic device on a flexible poly(styrene‐block‐isobutylene‐block‐styrene) substrate and the inherent biocompatibility of PDA demonstrates its potential toward more sophisticated implantable neuromorphic circuits for advanced neuroprosthetics.
Cover crops and soil ecosystem engineers
Authors: Blanco‐Canqui Humberto
Published: July 2022

Earthworms are key to the engineering of soil ecosystem services. However, how cover crops (CCs) influence these ecosystem engineers has not been widely discussed. This paper reviews (a) CC effects on earthworm abundance, biomass, diversity, and related soil ecosystems services and (b) factors affecting CC effects on earthworms. A review of existing literature (through 29 May 2022) found 22 CC studies on earthworm abundance and 10 on earthworm biomass, but studies on earthworm diversity were few. Cover crops increased earthworm abundance in 13 of 22 studies, increased biomass in five of 10 and had no effect in the rest of studies compared with no CCs. The change (Δ increase) was 11 to 535 earthworms m–2 and 11 to 44 g of earthworm biomass m–2. Cover crop effects on earthworm diversity are mixed. Earthworm abundance was more responsive to CCs than soil C and physical properties, suggesting earthworm abundance should be included as a sensitive measurement in soil health status. Cover crops with low C/N under no‐till or reduced‐till systems promote earthworm abundance relative to CCs with high C/N under conventionally tilled systems. Cover crop mixtures do not increase earthworm abundance more than monocultures. Earthworm abundance generally increases with increasing precipitation (r = 0.45; p = .025) and temperature (r = 0.36; p = .10). Overall, CCs increase earthworm abundance but have mixed effects on earthworm biomass and diversity, although more data from different CC management scenarios and climates are needed for more robust conclusions.
Growth in individuals with SATB2‐associated syndrome
Authors: Zarate Yuri A. , Kannan Amrit , Bosanko Katherine A. , Caffrey Aisling R.
Published: July 2022

SATB2‐associated syndrome (SAS) is an autosomal dominant multisystemic disorder caused by alterations in the SATB2 gene. In addition to a predominant neurodevelopmental phenotype, individuals with SAS often present with feeding difficulties and growth retardation that persist past infancy. In this study, we present growth and measurement data from 211 individuals (53.6% male, 46.4% female) with SAS due to different molecular mechanisms. To delineate growth in this population, we constructed SAS‐specific growth charts by sex from birth to 10 years of age. Smoothed SAS percentiles were superimposed with normative percentiles from WHO (birth to <24 months) and CDC (24 months to 10 years) growth charts. Individuals with SAS tend to display slower postnatal growth with 22.2% (32/144), 19.0% (26/137), and 21.6% having at least one weight, height, or weight‐for‐length /body mass index (BMI) measurement below −2 standard deviations, respectively. The SAS 50th centile BMI was consistently below the normative data 50th centile and negative mean Z‐scores were seen across almost all age groups analyzed for both genders. Individuals with chromosomal abnormalities displayed significantly lower weight for age Z‐score, height for age Z‐scores, occipitofrontal head circumference for age Z‐scores, and BMI for age Z‐scores compared to either missense or null variants.
Selective Confinement of Rare‐Earth‐Metal Hydrates by a Capped Metallo‐Cage under Aqueous Conditions
Authors: Tabuchi Ryosuke , Takezawa Hiroki , Fujita Makoto
Published: July 2022

The properties of rare‐earth‐metal ions in aqueous media often depend on their various hydration modes, which allow them to exist as monomeric or oligomeric species with different coordination numbers. Capturing rare‐earth‐metal ions in a confined cavity can fix their hydration modes and thus enable their intrinsic properties to be distinguished. However, the isolation of ionic species from bulk aqueous media is not an easy task due to competitive interaction with bulk water. Here, we report the encapsulation of hydrated rare‐earth‐metal ions in a hydrophobic cavity of a synthetic cage. Cap‐like counter anions located at the cage's portals play an important role in capturing the rare‐earth metals at a fixed position via electrostatic interactions. Preferential encapsulation of early lanthanoid (III) ions was observed even though all the rare‐earth metals have the same hydration number and geometry, as visualized by the competitive inclusion of a dye molecule. Accordingly, the early lanthanoid ion was selectively extracted from a mixture of two rare‐earth‐metal ions.
Isothermal Rolling Circle Amplification and Lanthanide‐Based FRET for Femtomolar Quantification of MicroRNA
Authors: Dekaliuk Mariia , Busson Pierre , Hildebrandt Niko
Published: July 2022

Quantification of DNA and RNA biomarkers via isothermal amplification technologies can significantly simplify biosensing and clinical diagnostics. However, highly sensitive and wash‐free assay formats based on time‐resolved Förster resonance energy transfer (TR‐FRET) have been limited to terbium (Tb) based FRET pairs and their application on specialized clinical instruments. Here, we present the implementation of rolling circle amplification (RCA)‐FRET to europium‐dye (Eu‐ATTO620) FRET pairs and its application on standard benchtop fluorescence plate readers. Eu‐ATTO620 RCA‐FRET was used to quantify microRNA‐21 (miR‐21) in a 1 to 100 pM concentration range on a SPARK multimode plate reader system. Detection limits down to 120±20 fM (18±3 attomol of miR‐21) and quantification of endogenous miR‐21 from the plasma of ovarian cancer patients using a KRYPTOR clinical plate reader demonstrated the broad applicability and clinical relevance of Eu‐dye‐based RCA‐FRET. The extension to both Eu and Tb based TR‐FRET and to standard bioanalytical laboratory instruments has the potential to significantly broaden the application and versatility of RCA‐FRET for simple, highly‐sensitive, and multiplexed bioanalysis.
Base‐free Air Oxidation of Chitin‐derived Glucosamine to Glucosaminic Acid by Zinc Oxide‐supported Gold Nanoparticles
Authors: Zheng Yue , Xu Di , Zhang Lei , Chen Xi
Published: July 2022

In this study, glucosaminic acid (GlcNA) was produced with the highest yield of ∼85% from chitin biomass‐derived glucosamine (GlcN) at 35 °C under atmospheric air in water, by using zinc oxide‐supported gold nanoparticles (Au/ZnO). The Au/ZnO catalyst prepared by the deposition‐precipitation (DP) method displayed remarkably superior catalytic performance to that prepared by the deposition‐reduction (DR) method, which led to >2‐fold enhancement in product yield. A lower apparent activation energy (Ea) was observed over the Au/ZnO (DP) for GlcNA formation compared with the Au/ZnO (DR) catalyst. Based on control tests and structural characterizations, the average particle size of Au nanoparticles (NPs) and the surface oxygen vacancy (OV) sites were the crucial factors on the catalytic activity. The work puts forward a green, mild and efficient approach to synthesize valuable amino acid from ocean‐based chitin biomass resources with air as the oxidant, adding on new possibilities of chitin biorefinery.
Attempt to obtain the general relativistic planet's motion by special relativity techniques
Authors: Kubo Yoshio
Published: July 2022

It is attempted to derive the general relativistic equation of motion for a planet and its solution solely by the special relativity techniques. The motion of a planet relative to the Sun and that of the Sun to the planet are solved independently in a special relativistic framework using the perturbation theory in celestial mechanics. The solution reveals a nature of the structure of the spacetime under the gravitation of the Sun, and then its effect on the planet's motion is examined. When the motion thus examined are compared with the one obtained by the general relativity theory in post‐Newtonian approximation, both are different concerning the mean motion and the radius of the orbit but exactly the same as for the perihelion precession.
Zusammenwirken von Faser‐ und Betonstahlbewehrung bei biegebeanspruchten UHPC‐Bauteilen
Authors: Huß Michael , Waldenhofer Roland , Freytag Bernhard , Viet Tue Nguyen
Published: July 2022

Ultrahochfester Beton (UHPC) bietet ein großes Potenzial hinsichtlich nachhaltiger Lösungen für Instandsetzungen und Verstärkungen von bestehenden Tragwerken, aber auch für ressourcensparende Neubauten. In diesem Zusammenhang ist eine Kombination zwischen Mikrostahlfasern und gewöhnlicher Betonstahlbewehrung sinnvoll, da sich Synergieeffekte bezüglich der Rissbreitenbegrenzung und des Lastabfalls bei Verformungslokalisation erzielen lassen. Zur Bestätigung dieser Einschätzung wurden Biegeversuche mit unterschiedlichen Querschnittsgeometrien und Bewehrungskombinationen durchgeführt. Dank moderner Messmethoden konnte hierbei die Rissbreitenentwicklung über den gesamten Versuchsablauf, auch bei sehr feinen Rissen, kontinuierlich erfasst werden. Die Analyse der Versuchsergebnisse zeigt, dass bei der Ermittlung der Biegetragfähigkeit des Querschnitts die volle Wirkung der Betonstahl‐ (Fließen) und der Faserbewehrung (Nachrisszugfestigkeit) addiert werden dürfen, unabhängig vom Fasergehalt. Auf Basis der gewonnen Messdaten wurde außerdem ein vereinfachter Ansatz zur Berechnung der Rissbreiten im Grenzzustand der Gebrauchstauglichkeit abgeleitet.
Holy grail of tissue regeneration: Size
Authors: Chen Kellen , Henn Dominic , Gurtner Geoffrey C.
Published: July 2022

Cells and tissue within injured organs undergo a complicated healing process that still remains poorly understood. Interestingly, smaller organisms respond to injury with tissue regeneration and restoration of function, while humans and other large organisms respond to injury by forming dysfunctional, fibrotic scar tissue. Over the past few decades, allometric scaling principles have been well established to show that larger organisms experience exponentially higher tissue forces during movement and locomotion and throughout the organism's lifespan. How these evolutionary adaptations may affect tissue injury has not been thoroughly investigated in humans. We discuss how these adapations may affect healing and demonstrate that blocking the most evolutionary conserved biologic force sensor enables large organisms to heal after injury with true tissue regeneration. Future strategies to disrupt tissue force sensors may unlock the key to regenerating after injury in a wide range of organ systems.
Penalized estimation of a class of single‐index varying‐coefficient models for integrative genomic analysis
Authors: Ng Hoi Min , Jiang Binyan , Wong Kin Yau
Published: July 2022

Recent technological advances have made it possible to collect high‐dimensional genomic data along with clinical data on a large number of subjects. In the studies of chronic diseases such as cancer, it is of great interest to integrate clinical and genomic data to build a comprehensive understanding of the disease mechanisms. Despite extensive studies on integrative analysis, it remains an ongoing challenge to model the interaction effects between clinical and genomic variables, due to high dimensionality of the data and heterogeneity across data types. In this paper, we propose an integrative approach that models interaction effects using a single‐index varying‐coefficient model, where the effects of genomic features can be modified by clinical variables. We propose a penalized approach for separate selection of main and interaction effects. Notably, the proposed methods can be applied to right‐censored survival outcomes based on a Cox proportional hazards model. We demonstrate the advantages of the proposed methods through extensive simulation studies and provide applications to a motivating cancer genomic study.
Technological advances in ocular trabecular meshwork in vitro models for glaucoma research
Authors: Bikuna‐Izagirre Maria , Aldazabal Javier , Extramiana Leire , Moreno‐Montañés Javier , Carnero Elena , Paredes Jacobo
Published: July 2022

Glaucoma is the leading cause of irreversible blindness worldwide and is characterized by the progressive degeneration of the optic nerve. Intraocular pressure (IOP), which is considered to be the main risk factor for glaucoma development, builds up in response to the resistance (resistance to what?) provided by the trabecular meshwork (TM) to aqueous humor (AH) outflow. Although the TM and its relationship to AH outflow have remained at the forefront of scientific interest, researchers remain uncertain regarding which mechanisms drive the deterioration of the TM. Current tissue‐engineering fabrication techniques have come up with promising approaches to successfully recreate the TM. Nonetheless, more accurate models are needed to understand the factors that make glaucoma arise. In this review, we provide a chronological evaluation of the technological milestones that have taken place in the field of glaucoma research, and we conduct a comprehensive comparison of available TM fabrication technologies. Additionally, we also discuss AH perfusion platforms, since they are essential for the validation of these scaffolds, as well as pressure–outflow relationship studies and the discovery of new IOP‐reduction therapies.
Pursuing a strategy of ‘common benefit’ in business: The adoption of the benefit corporation model in Italy
Authors: Marchini Pier Luigi , Tibiletti Veronica , Fellegara Anna Maria , Mazza Tatiana
Published: July 2022

A benefit corporation (BC) is a for‐profit company that pursues common benefits for stakeholders. Adopting institutional theory, we analyse the characteristics of the company in relation to the common benefits a BC pursue and how BC model fits with corporate social responsibility (CSR) practices defined in literature. BCs were introduced by a 2016 law in Italy, that was the first European country to approve legislation for BCs, under which a company must indicate its specific common benefit in its articles of association (AoAs). We run a multivariate regression on data from a content analysis on companies' AoA and then use questionnaire data to perform a cluster analysis and interviews to provide additional information. We show that larger and profitable firms focus on customers, while mature firm focus on the environment in the definition of common benefit in AoA. There is resistance to profit sharing. Industry and location specific are important drivers. Among first evidences, it is interesting to see that the most frequent perceived advantage of BC status is differentiation, BC and BCorp do not in practice overlap, and ownership is the main promoter of the change to become BC.