bluuebunny/crossref_metadata_2025 huggingface dataset:
Scattering of an obliquely incident plane wave from a circular clad rod
Authors: Honarvar F. , Sinclair A. N.
Published: July 2002

The problem of scattering of an obliquely incident plane acoustic wave from an infinite solid elastic clad rod is formulated. Numerical calculations show the effects of the variations of the cladding thickness on both the backscattered pressure spectrum and individual normal modes. It is shown that various resonance frequencies have different levels of sensitivity to variations of the cladding thickness. Experimental measurements are also performed at both normal and oblique incident angles on a copper-clad aluminum rod; good agreement is observed between the calculated and the measured results. These results demonstrate the potential of acoustic resonance scattering procedures for application in nondestructive evaluation (NDE) of clad rods.
Magnetic excitation and acoustic detection of torsional modes of spherical shells in water
Authors: Hefner Brian T. , Marston Phillip L.
Published: July 2002

The modal structure of an empty nearly spherical metallic shell subject to fluid loading was examined using a novel form of EMAT (electromagnetic acoustic transducer) used previously for shells in air [B. T. Hefner and P. L. Marston, J. Acoust. Soc. Am. 99, 2594 (1996)]. It was found to be possible to magnetically excite and acoustically detect the high-Q torsional modes of the shell in water using this method. The quality factor, Q, was found to be approximately 1500. The presence of a bias field in addition to the oscillating field of the coil is needed to excite these modes. The bias field was introduced either by the magnetization of the 440C stainless-steel shell itself or by introducing an external field in the case of an unmagnetized shell. It was found that the lowest torsional mode could be excited by an oscillating field at 60 kHz (the mode frequency) and at 30 kHz (half the excited mechanical frequency). The modes were detected by a hydrophone placed near the shell, however, the mechanism for producing this acoustic signal is poorly understood because it depends on some lack of perfect symmetry for the shell. [Work supported by the Office of Naval Research.]
Wave attenuation in catalytic converters: Reactive versus dissipative effects
Authors: Selamet A. , Easwaran V. , Novak J. M. , Kach R. A.
Published: July 2002

Acoustic wave propagation and attenuation in catalytic converters are investigated in the present study. The relationships for wave propagation in a catalytic monolith are derived first and then coupled to the wave propagation in tapered ducts which are commonly placed at either end of the monolith. Analytical and finite element approaches are used to solve the resulting coupled system of equations. Theoretical predictions are then compared with the experimental results for two different (one circular and the other oval) catalyst configurations. The attenuation characteristics of the catalyst with and without the monolith are also investigated.
Effects of wide band inhibitors in the dorsal cochlear nucleus. II. Model calculations of the responses to complex sounds
Authors: Blum Jacob J. , Reed Michael C.
Published: July 2002

In a previous modeling study of signal processing in the dorsal cochlear nucleus [Reed and Blum, J. Acoust. Soc. Am 96, 1442–1453 (1997)] it was shown that inclusion of a wideband inhibitor (WBI) greatly improved the fit between model response maps and the experimental response maps of type IV units to pure tones. In this study we examine the effect of the WBI on the responses to complex sound stimuli such as broadband noise (BBN), notch noise, noise bands, and band/notch combinations. A new and more realistic model for auditory nerve (AN) response in the presence of different levels of noise is used. It is shown that one can explain and understand the qualitative features of virtually all the published data on type II and type IV unit responses to BBN, notch noise and noise bands. The monotone decreasing response of the maximum firing rate of type II units to noise bands of increasing width that is observed experimentally occurs in the model due to the increasing inhibition of type II cells by the WBI. Similarly, the various nonmonotone patterns of maximum firing rate of type IV units to noise bands of increasing width is shown to arise from the complex and highly nonlinear effects of inhibition from the type II to type IV and the WBI to type IV cells and the nonlinear direct excitation from the AN to the type IV cells. A number of experiments using double notches, double noise bands, or notch-noise band pairs are suggested which, by comparison with model results, would allow one to infer probable connectional patterns between type II and type IV units and between the WBI units and the type IV units.
Functional anatomy of the middle ear of insectivores
Authors: Mason Matthew J.
Published: July 2002

An electrical model has been constructed of the middle ear of land mammals [Hemilä et al., Hearing Res. 85, 31–44 (1995)]. This model can roughly predict the nature of air hearing in an animal, given the values of certain anatomical parameters for that animal. In the present study, light microscopy was used to investigate the anatomy of the middle ears of some representative members of the Insectivora. The nature of air hearing in these mammals was predicted, using an augmented version of the model. The model predicts that within the family Chrysochloridae (golden moles) there are genera (e.g., Chrysochloris and Chrysospalax) that have ears which appear to be very poorly adapted to the impedance-matching function required for efficient air hearing. The structure of the relatively enormous mallei of golden moles in these genera suggests that their ossicles are primarily adapted towards transmission of gound vibrations. A mechanism of ossicular inertia has been proposed. The electrical model predictions imply that subterranean mammals may be preadapted to evolve a more efficient mechanism for bone conduction of ground vibrations. Certain unusual features of the middle ear apparatus of other subterranean mammals may be interpreted in this light. [Work supported by B.B.S.R.C.]
Nonlinear bubble dynamics and light emission in single-bubble sonoluminescence
Authors: Gaitan Felipe , Holt Glynn
Published: July 2002

The paradigm system for studying light emission from bubbles has been a single, acoustically levitated air bubble in water. Such a bubble, whose volume pulsations are forced by the time-varying portion of the levitating acoustic field, has a rich dynamic life over a large range of the driving pressure-bubble size parameter space. Measurements have been made of bubble dynamics over a large part of a bubble’s parameter space, including the light emission regime. In the context of these measurements, the relationship between observed light emission and the activity of the oscillating bubble will be discussed. In particular, it will be explained how the constraints of mechanical stability and mass flux stability dictate what all experiments in SBSL have seen, namely a very small window of parameter space where light is observed to be emitted. Experimental evidence will be presented to make a clear distinction between features of SL which are due to the mechanism for light emission and those that are due to the dynamics of gas bubbles. [Work supported by NASA and the Office of Naval Research.]
Ultrasonic surface waves above rectangular-groove gratings
Authors: Kelders Luc , Allard Jean F. , Lauriks Walter
Published: July 2002

A modal model, initially developed to modelize diffraction of electromagnetic waves by rectangular-groove gratings, is used to describe ultrasonic surface waves above the same structures in air. A simple analytical formulation which provides results comparable to the modal method is presented. Measurements performed on ultrasonic surface waves are compared to predictions obtained with the simplified formulation and the modal model.
Patterns of vowel-to-vowel coarticulation in Greek and English
Authors: Okalidou Areti , Koenig Laura L.
Published: July 2002

Many previous studies have indicated that coarticulatory behavior differs systematically across languages. One specific hypothesis, made by Manuel and Krakow (1984), is that languages with larger vowel inventories show reduced vowel-to-vowel coarticulation because their crowded vowel spaces impose more stringent requirements for maintaining phonological distinctiveness. The present study is designed (a) to test this prediction in Greek versus English, which have small and large vowel inventories, respectively; and (b) to investigate which parameters of the vowel system are most responsible for shaping language-specific coarticulatory constraints. Adult monolingual speakers of each language were recorded, producing VCV utterances embedded in phonologically similar carrier phrases. Vowels included all five vowels of Greek, /i,e,a,o,u/, and their closest counterparts in American English, and the medial consonant varied between labial and alveolar places of articulation. To provide an independent measure of production variability for each vowel, speakers also produced the vowels in real words of the form /pVt/ or /bVt/, embedded in the same carrier phrases. Preliminary data are presented for two speakers of each language, and discussed in terms of vowel type, distribution within the vowel space, and the size of vowel areas within F1−F2 space.
Modulation masking produced by beating modulators
Authors: Moore Brian C. J. , Sek Aleksander , Glasberg Brian R.
Published: July 2002

This study examined whether “modulation masking” could be produced by temporal similarity of the probe and masker envelopes, even when the masker envelope did not contain a spectral component close to the probe frequency. Both masker and probe amplitude modulation were applied to a single 4-kHz sinusoidal or narrow-band noise carrier with a level of 70 dB SPL. The threshold for detecting 5-Hz probe modulation was affected by the presence of a pair of masker modulators beating at a 5-Hz rate (40 and 45 Hz, 50 and 55 Hz, or 60 and 65 Hz). The threshold was dependent on the phase of the probe modulation relative to the beat cycle of the masker modulators; the threshold elevation was greatest (12–15 dB for the sinusoidal carrier and 9–11 dB for the noise carrier, expressed as 20 log m) when the peak amplitude of the probe modulation coincided with a peak in the beat cycle. The maximum threshold elevation of the 5-Hz probe produced by the beating masker modulators was 7–12 dB greater than that produced by the individual components of the masker modulators. The threshold elevation produced by the beating masker modulators was 2–10 dB greater for 5-Hz probe modulation than for 3- or 7-Hz probe modulation. These results cannot be explained in terms of the spectra of the envelopes of the stimuli, as the beating masker modulators did not produce a 5-Hz component in the spectra of the envelopes. The threshold for detecting 5-Hz probe modulation in the presence of 5-Hz masker modulation varied with the relative phase of the probe and masker modulation. The pattern of results was similar to that found with the beating two-component modulators, except that thresholds were highest when the masker and probe were 180° out of phase. The results are consistent with the idea that nonlinearities within the auditory system introduce distortion in the internal representation of the envelopes of the stimuli. In the case of two-component beating modulators, a weak component is introduced at the beat rate, and it has an amplitude minimum when the beat cycle is at its maximum. The results could be fitted well using two models, one based on the concept of a sliding temporal integrator and one based on the concept of a modulation filter bank.
A three-dimensional propagation algorithm using finite azimuthal aperture
Authors: Smith Kevin B.
Published: July 2002

The use of three-dimensional (3-D) propagation models is becoming increasingly common in current underwater acoustics applications. Such models typically treat the propagation as a function of range, depth, and bearing, consistent with previous multibearing two-dimensional (N×2-D) models. However, to obtain accurate 3-D solutions at long ranges, many bearings must be computed in order to maintain the necessary cross-range resolution between bearings. In this paper, a 3-D parabolic equation (PE) model is developed with a marching algorithm based on the split-step Fourier technique in both depth and azimuthal bearing. The algorithm includes a scheme to compute the solution for only a finite azimuthal aperture rather than the full 360° of bearing. The success of this algorithm allows for increased cross-range resolution at long range without increasing the number of bearings needed in the calculation. Results of this technique are compared to results from a suggested benchmark case.
Acoustic wave motion along a narrow cylindrical duct in the presence of an axial mean flow and temperature gradient
Authors: Peat Keith S. , Kirby Ray
Published: July 2002

A numerical solution is presented to the problem of nonisentropic acoustic wave motion in a circular capillary tube in the presence of both axial mean flow and a background axial temperature gradient. The effects of the radial components of the acoustic velocity are included in the analysis. The main application area is in the study of the acoustic effects of catalytic converters. The solution makes use of a series expansion and is valid for small relative changes in the background temperature, which are typical of this application area. Various solutions to the problem have been obtained previously, using different simplifications to the complete problem which is considered here. It is shown that each of the simplifications results in errors for the predicted attenuation of at least 20 dB/m, using conditions typical for catalytic converters. In particular, the isentropic assumption is shown to be invalid.
Correlation of the Weissenberg Rheogoniometer with Other Methods
Authors: Philippoff W. , Stratton R. A.
Published: July 2002

Measurements of the recoverable shear, s using three different methods, recoil, Weissenberg rheogoniometer, and flow birefringence, have been made on solutions of polyisobutylene in oil and polystyrene in Aroclor. All three methods, within their applicability limits, gave consistent results, calculating the recoil values from the rheogoniometer without the factor of 12 required by the theories using constitutive equations for viscoelastic liquids. Especially, these experiments with “matching solvents” gave a very good agreement on s measured in the rheogoniometer and flow birefringence.
A Comparison of Creep Theories for Multiaxial Loading of Polyethylene
Authors: Brown R. L. , Sidebottom O. M.
Published: July 2002

Several creep theories are investigated for multiaxial loading of high-density polyethylene, a slightly cross-linked polymer demonstrating a nonlinear stress-strain-time relationship. Among the theories considered are nonlinear viscoelastic models, isochronous stress-strain diagrams employing a hyperbolic sine relationship, and multiple integral representations. The material parameters for these theories were determined from simple tension, compression, torsion and biaxial creep tests using single step loading. These theories were then analyzed for multiple step pressure-tension loading of a thin walled cylinder, in which the internal pressure and the axial load were varied independently of each other to check the effect of stress history on theory accuracy.
Linear Stability of Plane Poiseuille Flow of Viscoelastic Liquids
Authors: Porteous K. C. , Denn M. M.
Published: July 2002

The stability of plane Poiseuille flow to infinitesimal perturbations was studied for the second order and Maxwell fluid rheological models. When the Deborah number based disturbance propagation is small the second order fluid is a consistent constitutive equation and the two models give identical results. This occurs for elasticity number (E) less than 5×10−4. At higher values of E the second order fluid cannot be used. The critical Reynolds number is a slowly decreasing function of E up to E≈10−4 and a rapidly decreasing function subsequently in the region where fluid relaxation effects become important. For a sufficiently elastic fluid the flow transition is governed by a new mode of the Orr-Sommerfeld equation and differs qualitatively from that for a Newtonian liquid. The results suggest the likelihood of low Reynolds number instability in highly elastic liquids.
Measurements of Pressure-Hole Error in Flow of Viscoelastic Polymeric Solutions: Effects of Hole Size and Solution Concentration
Authors: Han Chang Dae , Kim Kwang Ung
Published: July 2002

In order to investigate the possibility of having pressure-hole errors when measuring pressure during experiments on the flow of polymer solutions through dies, slit dies were constructed having various aspect ratios and various sizes of pressure hole. Each slit die has three pressure transducers mounted flush with the wall of one long side of the rectangular slot and, in the opposite side, three other transducers mounted through pressure holes. Measurements of wall pressure were taken on both walls along the longitudinal centerline of the die. In the present study, first Newtonian liquids of two different viscosities (INDOPOL polybutenes L-50 and L-100) were used. It has been found that the Newtonian liquids tested give rise to pressure-hole errors, which are correlatable with the viscous effect alone. And then, three viscoelastic polymeric solutions were used. These were: 2% polyisobutylene (PIB) in decalin, 2% carboxymethyl cellulose (CMC) in water, and aqueous solutions of polyacrylamide (ET597) of varying concentrations: 0.6, 2.0, 4.0, 6.0, and 8.0 weight-percent. The wall pressure measurements obtained in the present study show that substantial pressure-hole errors are present when 0.6% ET597 solutions are being studied, increasing with volumetric flow rate and hole size, and that pressure-hole errors are decreased as solution concentration is increased. It has been found that ET597 solutions of 6% concentration and higher give almost negligible pressure-hole errors, i.e., they fall within the measurement error. This concentration dependence of pressure-hole error indirectly corroborates the earlier findings by Han, who reported that polymer melts give no discernible pressure-hole error. A general expression is proposed for correlating pressure-hole error with hole size, viscous effect, and elastic effect. This correlation is then used to explain the observed difference in pressure-hole errors for ET597 solutions of different concentration.
The Shearing Flows of the BKZ Fluid
Authors: Yen Hsiaw-Chin , McIntire Larry V.
Published: July 2002

Available experimental data of shearing flows are used to test the BKZ fluid model. The strain-energy function is assumed in the form of U=M(s)g(I1, I2), where M(s) is obtained from the small-amplitude oscillatory shearing data. The function F=2(∂g/∂I1)+2(∂g/∂I2) is then calculated from simple shearing data (either shear stress or first normal stress difference). Nonuniqueness of F is seen in the results and it is suggested that the BKZ fluid model can be used only up to moderate shear rates. The stress growth after the start of simple shearing is also predicted and compared with experimental data. The prediction of stress relaxation after the cessation of simple shearing is also made and is qualitatively in agreement with experimental data.
Study on the Flow of Polymer Melts in a Curvilinear Duct. I. Stratified Bicomponent Flow of Polymer Melts between Two Curved Parallel Plates
Authors: Akita Osamu , Ito Katsuhiko
Published: July 2002

A theoretical study is conducted in order to investigate the stratified bicomponent flow of molten polymers between two curved parallel plates. In this report, a modified cylindrical coordinate system is used to analyze the fully developed flow of a Newtonian incompressible fluid under a uniform pressure gradient. The velocity distribution and volumetric flow rate for each phase and the total volumetric flow rate are calculated by solving the equation of motion under the geometrical restrictions of the flow field. Lastly, as a typical non-Newtonian case, the power law fluid is briefly discussed.
A Comparison of the Burden of Thyroid Cancer Among the European Union 15+ Countries, 1990-2019
Authors: Schuster-Bruce James , Jani Chinmay , Goodall Richard , Kim Dae , Hughes William , Salciccioli Justin D. , Marshall Dominic , Shalhoub Joseph
Published: March 2022

Importance

The global incidence of thyroid cancer has been increasing rapidly, and this increase has had an attendant burden on health systems. However, it is unclear how the burden of this disease differs among the pre-2004 countries of the European Union (Austria, Belgium, Denmark, Finland, France, Germany, Greece, Ireland, Italy, Luxembourg, Netherlands, Portugal, Spain, Sweden, and the UK), US, Australia, Canada, and Norway (EU15+).

Objective

To assess the trends in mortality, incidence, and disability-adjusted life-years (DALYs) associated with thyroid cancer between 1990 and 2019 in EU15+ nations. Data analysis was conducted from July 11 to October 11, 2021.

Design, Setting, and Participants

Observational cross-sectional analysis of the incidence of thyroid cancer was conducted using data obtained from the Global Burden of Disease Study database. Nineteen countries of the EU15+ were included.

Exposures

Thyroid cancer.

Main Outcomes and Measures

Age-standardized incidence rates (ASIRs), age-standardized mortality rates (ASMRs) and DALYs were extracted for individual EU15+ countries per sex for each of the years from 1990 to 2019, and mortality-to-incidence indexes were computed. Joinpoint regression analysis was used to describe the trends.

Results

Thirteen of 19 countries (68%) showed an average annual percentage change increase in ASIR across the study period (range, 0.2%-2.5%). Joinpoint regression analysis revealed largely plateauing ASIR trends in recent years across most EU15+ nations since 1990. Between 2011 and 2019, the estimated annual percentage change in the US was 0. Australia, Denmark, and the US were the only countries with increasing ASMR trends with positive average annual percentage changes: Australia, 0.6 (95% CI, 0.2-1.0); Denmark, 1.0 (95% CI, 0.8-1.3); and US, 0.4 (95% CI, 0.4-0.5); the remaining 16 countries showed negative trends (range, −0.2 to −2.1). Disability-adjusted life-years decreased in all EU15+ countries except Australia, Denmark, and the US.

Conclusions and Relevance

This cross-sectional analysis found that overall, the burden of thyroid cancer across EU15+ countries appears to be decreasing, evidenced by plateauing incidence rates and reductions in mortality and DALYs over the 30-year study period. However, the US and Australia appear to have increasing ASMR and DALY trends. Ongoing observation is required to monitor how changes in international clinical practice guidelines affect thyroid cancer DALYs and mortality.
Moraxellaceae
Authors: Fernández‐Garayzábal José Francisco , Miguela‐Villoldo Pedro , Vela Ana Isabel
Published: March 2022

Mo.ra.xel.la.ce'ae. N.L. fem. n. Moraxella, type genus of the family; suff.‐aceae, ending to denote family;N.L. fem. pl. n. Moraxellaceae, the family ofMoraxella.

Proteobacteria / Gammaproteobacteria / Pseudomonadales / Moraxellaceae

Cells are rod shaped, coccoid, or coccal or may exhibit a characteristic multicellular micromorphology. Cells usually occur singly, in pairs, or in short chains. Gram‐stain‐negative. Aerobically or facultatively anaerobic. Endospores are not observed. The cells are not motile in liquid media, but surface‐bound motility may be observed. Capsules and fimbriae may be present. Chemoorganotrophic. Psychrophilic or mesophilic. Most members are catalase‐ and oxidase‐positive. The fatty acid profiles show the presence of mainly unbranched, saturated, and mono‐ or diunsaturated fatty acids with predominantly 16 and 18 carbon atoms. DNA G + C content ranges from 35 to 66 mol%. The family comprises the generaMoraxella,Acinetobacter,Psychrobacter,Enhydrobacter,Alkanindiges,Perlucidibaca,Paraperlucidibaca,Agitococcus,Faucicola,Fluviicoccus,Clavicella, andAquirhabdus. Most members are considered saprophytes of little clinical significance, while a few species represent important infectious agents.

DNA G + C content (mol%): 35–66.

Type genus:MoraxellaLwoff 1939AL(Approved Lists 1980) emend. Henriksen and Bøvre 1968.
Tatumella
Authors: Avontuur Juanita R. , Palmer Marike , Coetzee Martin P.A. , Steenkamp Emma T.
Published: March 2022

Ta.tum.el'la N.L. fem. dim. n.
Tatumella
, named to honor Harvey Tatum, an American bacteriologist who made many contributions to our understanding of the classification and identification of fermentative and nonfermentative bacteria of medical importance.

Pseudomonadota / Gammaproteobacteria / Enterobacterales / Enterobacteriaceae / Tatumella

The genus
Tatumella
is diverse and of clinical and agricultural importance. Some members are human or plant pathogens, while others have been isolated from fruit, soil, and clinical samples. The genus forms a monophyletic group within the family
Enterobacteriaceae
and includes six validly published species.
Tatumella
represents facultatively anaerobic, fermentative, nonencapsulated, non‐spore‐forming, and Gram‐negative bacteria that can be either motile or nonmotile. In addition to various phenotypic traits, the lack of peritrichous flagella and the ability to produce 2‐ketogluconate dehydrogenase differentiate
Tatumella
from other closely related genera. In general, however, the genus shares many lifestyle characteristics with other genera in the family
Enterobacteriaceae
, including taxa of biotechnological and clinical importance.

DNA G + C content (mol%)
: 49.7–52.8 (high‐performance liquid chromatography and genome analysis).

Type species
:
Tatumella ptyseos
Hollis et al. 1981, VL8.
Wall Microstructures of High Aspect Ratio Enabled by Near‐Field Electrospinning
Authors: Sadaf Ahsana , Elter Maximilian , Mager Dario , Bunz Uwe H. F. , Islam Monsur , Korvink Jan G.
Published: March 2022

Near‐field electrospinning (NFES) holds the potential to develop into a versatile additive nanomanufacturing platform. However, the impact of a variety of processing variables remains unresolved.Herein, the effect of solvents used to prepare suitable solutions for 3D microstructuring by electrospinning is studied. 3D straight walls of stacked fibers are fabricated using a layer‐by‐layer fiber deposition approach. The effect of the choice of substrate material is also explored. The results show that a high vapor pressure, and a low dielectric constant of the solvent, as well as a high substrate conductivity facilitate improved stacking of fiber layers. Utilizing these conditions, 3D stacked walls of polyethylene oxide are fabricated, and a maximum aspect ratio of 191.7 ± 52.6, while using a chromium/gold substrate and dichloromethane/methanol as the solvent is achieved.
Precise Assembly of Highly Crystalline Colloidal Photonic Crystals inside the Polyester Yarns: A Spray Coating Synthesis for Breathable and Durable Fabrics with Saturated Structural Colors
Authors: He Yuying , Liu Luyao , Fu Qianqian , Ge Jianping
Published: March 2022

It is a great challenge to prepare highly crystalline photonic crystal (PC)‐modified fabrics with saturated colors without sacrificing the wearing experience, such as breathability and softness, at the same time. Here, a spray coating process is developed to precisely assemble the colloidal PCs inside every yarn of the polyester (PET) fabric. High surface tension and high boiling point for the solvent of colloidal solution, as well as low twist angle, large weave cycles, and large tightness for the fabric substrate, are found to be favorable to the formation of high‐quality PC‐modified fabrics. In addition, the as‐prepared PC/PET fabrics have saturated and durable colors thanks to the highly crystalline PC structures and the polyacrylate adhesives. They also possess good softness and high breathability as the precise colloidal assembly in the yarn avoids the blocking of weaving holes and cracks.
Hybrid‐Piezoelectret Based Highly Efficient Ultrasonic Energy Harvester for Implantable Electronics
Authors: Wan Xiao , Chen Ping , Xu Zisheng , Mo Xiwei , Jin Hongrun , Yang Wei , Wang Shuixiang , Duan Jiangjiang , Hu Bin , Luo Zhiqiang , Huang Liang , Zhou Jun
Published: March 2022

Implantable ultrasonic energy harvesters that scavenge wireless mechanic energy from ultrasound own remarkable potential in advanced medical protocols for neuroprosthetics, wireless power, biosensor, etc. The main challenge for this kind of device is to achieve high‐efficiency energy conversion in a weak ultrasonic pressure field. Here, a multilayered piezoelectret with strain enhanced piezoelectricity by introducing a parallel‐connected air hole array in an interdielectric layer sandwiched between a pair of electrets for an efficient ultrasonic energy harvester is presented. This device delivers a remarkable peak output power around 13.13 mW and short‐circuits current around 2.2 mA when implanted into tissues at 5~10 mm under an ultrasonic probe setup at 25 mW cm−2, which is higher than the required power threshold of bioelectronic devices and current threshold of nerve stimulation. Furthermore, the feasibility of supplying power to implantable bioelectronics and working as neuroproteins for peripheral nerve stimulation are both demonstrated. It is anticipated that this highly efficient, easily fabricated, and biocompatible device will potentially enable applications for multifunctional and advanced implantable bioelectronics in the next generation of diagnosis and therapy.
Work‐Function‐Tunable MXenes Electrodes to Optimize p‐CsCu2I3/n‐Ca2Nb3‐xTaxO10 Junction Photodetectors for Image Sensing and Logic Electronics
Authors: Chen Jiaxin , Liu Xinya , Li Ziqing , Cao Fa , Lu Xiang , Fang Xiaosheng
Published: March 2022

Tunable work function has a high profile for the MXene‐based optoelectronic devices, and surface modification provides the huge potential to shift its Fermi level and modulate the work function. In this work, the window of MXene's work function is engineered from 4.55 to 5.25 eV by surface modification with LiF, Se, and polyethylenimine ethoxylated (PEIE). The vertical p‐CsCu2I3/n‐Ca2Nb3‐xTaxO10 junction photodetectors are constructed on the basis of the above surface‐modified MXenes, which changes the Schottky barrier between n‐Ca2Nb3‐xTaxO10 and the electrodes. In particular, the rectification effect is significantly enhanced by utilizing PEIE‐decorated MXene electrodes, resulting in a high rectification ratio of 16 136 and improved UV responsivity of 81.3 A W–1. Such high‐performance devices based on MXenes electrodes are compatible with the standard clean room fabrication process, realizing large‐scale flexible UV detectors that maintain 80% of the original current after 5000 times bending. Meanwhile, a photodetector array stimulated with UV of different wavelengths is constructed to reveal its potential for image sensing. Finally, functional “AND” and “OR” optoelectronic logic gates are developed for UV communication using Au/CsCu2I3/Ca2Nb3‐xTaxO10/MXene–PEIE photodetectors, enriching the application of MXene‐based optoelectronic devices. This work on tuning MXene work function via surface modification demonstrates that MXene is a promising candidate for future optoelectronics.
Parenchyma fractions drive the storage capacity of nonstructural carbohydrates across a broad range of tree species
Authors: Zhang Guangqi , Mao Zhun , Fortunel Claire , Martínez‐Vilalta Jordi , Viennois Gaëlle , Maillard Pascale , Stokes Alexia
Published: March 2022

Premise

Nonstructural carbohydrates (NSCs) play a key role in tree performance and functioning and are stored in radial and axial parenchyma (RAP) cells. Whether this relationship is altered among species and climates or is linked to functional traits describing xylem structure (wood density) and tree stature is not known.

Methods

In a systematic review, we collated data for NSC content and the proportion of RAP in stems for 68 tree species. To examine the relationships of NSCs and RAP with climatic factors and other functional traits, we also collected climatic data at each tree's location, as well as wood density and maximum height. A phylogenetic tree was constructed to examine the influence of species' evolutionary relationships on the associations among NSCs, RAP, and functional traits.

Results

Across all 68 tree species, NSCs were positively correlated with RAP and mean annual temperature, but relationships were only weakly significant in temperate species and angiosperms. When separating RAP into radial parenchyma (RP) and axial parenchyma (AP), both NSCs and wood density were positively correlated with RP but not with AP. Wood in taller trees was less dense and had lower RAP than in shorter trees, but height was not related to NSCs.

Conclusions

In trees, NSCs are stored mostly in the RP fraction, which has a larger surface area in warmer climates. Additionally, NSCs were only weakly linked to wood density and tree height. Our analysis of evolutionary relationships demonstrated that RAP fractions and NSC content were always closely related across all 68 tree species, suggesting that RAP can act as a reliable proxy for potential NSC storage capacity in tree stems.
Employment and risk of female breast cancer in Denmark
Authors: Pedersen Julie E. , Hansen Johnni
Published: March 2022

Background

Occupational exposures may play a role in breast cancer etiology, and research focusing on identifying high‐risk workplaces is important to advance the understanding and prevention of breast cancer.

Methods

We undertook a population‐based nested case–control study among women who were less than 70 years of age and born in Denmark, based on registry data including 38,375 breast cancer cases and 191,875 controls matched on year of birth, with information on lifetime work history. Odds ratios for women ever employed in a job branch were adjusted for socioeconomic status and reproductive variables.

Results

Adjusted odds ratios of less than 0.75 were observed for several occupations in agriculture, hunting, forestry, and fishing, while increased risk patterns (odds ratios greater than 1.50) were noted for a number of production occupations, including employment in graphics and printing, and metal and machinery production. In services, several military professions were also associated with a high increased breast cancer risk.

Conclusions

The study shows a variation in the risk of female breast cancer by employment in different industrial and occupational sectors, and suggests that certain occupational exposures, for example, outdoor work, organic solvents, polycyclic aromatic hydrocarbons (PAHs), and night‐shift work may play a role in the risk of breast cancer. Further hypothesis‐testing studies focusing on these employments with a detailed assessment of specific occupational exposures are warranted.
The seventh international RASopathies symposium: Pathways to a cure—expanding knowledge, enhancing research, and therapeutic discovery
Authors: Kontaridis Maria I. , Roberts Amy E. , Schill Lisa , Schoyer Lisa , Stronach Beth , Andelfinger Gregor , Aoki Yoko , Axelrad Marni E. , Bakker Annette , Bennett Anton M. , Broniscer Alberto , Castel Pau , Chang Caitlin A. , Cyganek Lukas , Das Tirtha K. , den Hertog Jeroen , Galperin Emilia , Garg Shruti , Gelb Bruce D. , Gordon Kristiana , Green Tamar , Gripp Karen W. , Itkin Maxim , Kiuru Maija , Korf Bruce R. , Livingstone Jeff R. , López‐Juárez Alejandro , Magoulas Pilar L. , Mansour Sahar , Milner Theresa , Parker Elisabeth , Pierpont Elizabeth I. , Plouffe Kevin , Rauen Katherine A. , Shankar Suma P. , Smith Shane B. , Stevenson David A. , Tartaglia Marco , Van Richard , Wagner Morgan E. , Ware Stephanie M. , Zenker Martin
Published: March 2022

RASopathies are a group of genetic disorders that are caused by genes that affect the canonical Ras/mitogen‐activated protein kinase (MAPK) signaling pathway. Despite tremendous progress in understanding the molecular consequences of these genetic anomalies, little movement has been made in translating these findings to the clinic. This year, the seventh International RASopathies Symposium focused on expanding the research knowledge that we have gained over the years to enhance new discoveries in the field, ones that we hope can lead to effective therapeutic treatments. Indeed, for the first time, research efforts are finally being translated to the clinic, with compassionate use of Ras/MAPK pathway inhibitors for the treatment of RASopathies. This biannual meeting, organized by the RASopathies Network, brought together basic scientists, clinicians, clinician scientists, patients, advocates, and their families, as well as representatives from pharmaceutical companies and the National Institutes of Health. A history of RASopathy gene discovery, identification of new disease genes, and the latest research, both at the bench and in the clinic, were discussed.
A patient with multilocus imprinting disturbance involving hypomethylation at 11p15 and 14q32, and phenotypic features of Beckwith‐Wiedemann and Temple syndromes
Authors: Grosvenor Sarah E. , Davies Justin H. , Lever Margaret , Sillibourne Julie , Mackay Deborah J. G. , Temple I. Karen
Published: March 2022

Beckwith‐Wiedemann syndrome (BWS) and Temple syndrome (TS) are classical imprinting disorders (IDs) with nonconfluent clinical features. We report here on a patient with clinical features of both syndromes, in whom epimutations were found at the BWS and TS imprinted regions, consistent with multilocus imprinting disturbance (MLID). This is the first case report of a patient with clinical features of both conditions who was found to have loss of methylation (LOM) of KCNQ1OT1: TSS‐DMR (ICR2) in the 11p15 imprinted region associated with BWS and LOM of MEG3: TSS‐DMR in the 14q32 imprinted region associated with TS. The report draws attention to the importance of testing for MLID as a cause of atypical clinical presentations of patients with IDs.
Examining the association between blood‐based biomarkers and humanpost mortemneuropathology in the University of Kentucky Alzheimer's Disease Research Center autopsy cohort
Authors: Winder Zachary , Sudduth Tiffany L. , Anderson Sonya , Patel Ela , Neltner Janna , Martin Barbara J. , Snyder Katherine E. , Abner Erin L. , Jicha Gregory A. , Nelson Peter T. , Wilcock Donna M.
Published: March 2022

Introduction

Clinically, detection of disease‐causing pathology associated with Alzheimer's disease (AD) and vascular contributions to cognitive impairment and dementia (VCID) is limited to magnetic resonance imaging and positron emission tomography scans, which are expensive and not widely accessible. Here, we assess angiogenic, inflammatory, and AD‐related plasma biomarkers to determine their relationships with humanpost mortemneuropathology.

Method

Plasma samples were analyzed using a digital immunoassay and pathological evaluation was performed by University of Kentucky Alzheimer's Disease Research Center neuropathologists. The association of plasma markers with neuropathology was estimated via proportional odds and logistic regressions adjusted for age.

Results

Included cases (N = 90) showed increased tau/amyloid beta (Aβ)42 ratio, glial fibrillary acidic protein (GFAP), vascular endothelial growth factor A (VEGF‐A), and placental growth factor (PlGF) were positively associated with higher level of AD neuropathological change, while higher Aβ42/Aβ40 ratio was inversely associated. Higher PlGF, VEGF‐A, and interleukin 6 were inversely associated with chronic cerebrovascular disease, while Aβ42/Aβ40 ratio was positively associated.

Discussion

Our results provide support for the continued study of plasma biomarkers as a clinical screening tool for AD and VCID pathology.
Crystalline Germanium(I) and Tin(I) Centered Radical Anions
Authors: Lim Li Feng , Judd Martyna , Vasko Petra , Gardiner Michael G. , Pantazis Dimitrios A. , Cox Nicholas , Hicks Jamie
Published: March 2022

An isostructural series of heavy Group 14 E(I) radical anions (Ge, Sn, Pb), stabilized by a bulky xanthene‐based diamido ligand are reported. The radical anions were synthesised by the one‐electron reduction of their corresponding E(II) precursor complexes with sodium naphthalenide in THF, yielding the radical anions as charge‐separated sodium salts. The series of main group radicals have been comprehensively characterized by EPR spectroscopy, X‐ray crystallography and DFT analysis, which reveal that in all cases, the spin density of the unpaired electron almost exclusively resides in ap‐orbital of π symmetry located on the Group 14 center.
Enhancing Enzyme Activity by the Modulation of Covalent Interactions in the Confined Channels of Covalent Organic Frameworks
Authors: Xing Chunyan , Mei Pei , Mu Zhenjie , Li Bixiao , Feng Xiao , Zhang Yuanyuan , Wang Bo
Published: March 2022

Controllable regulations on the enzyme conformation to optimize catalytic performance are highly desired for the immobilized biocatalysts yet remain challenging. Covalent organic frameworks (COFs) possess confined channels with finely tunable pore environment, offering a promising platform for enzyme encapsulation. Herein, we covalently immobilized the cytochrome c (Cyt c) in the size‐matched channels of COFs with different contents of anchoring site, and significant enhancement of the stability and activity (≈600 % relative activity compared with free enzyme) can be realized by optimizing the covalent interactions. Structural analyses on the immobilized Cyt c suggest that covalent bonding could induce conformational perturbation resulting in more accessible active sites. The effectiveness of the covalent interaction modulation together with the tailorable confined channels of COFs offers promise to develop high‐performance biocatalysts.
More than a Leaving Group: N‐Phenyltrifluoroacetimidate as a Remote Directing Group for Highly α‐Selective 1,2‐cis Glycosylation
Authors: Liu Xianglai , Song Yingying , Liu Ao , Zhou Yueer , Zhu Qian , Lin Yetong , Sun Huiyong , Zhu Kaidi , Liu Wei , Ding Ning , Xie Weijia , Sun Haopeng , Yu Biao , Xu Peng , Li Wei
Published: March 2022

The anomeric configuration can greatly affect the biological functions and activities of carbohydrates. Herein, we report that N‐phenyltrifluoroacetimidoyl (PTFAI), a well‐known leaving group for catalytic glycosylation, can act as a stereodirecting group for the challenging 1,2‐cis α‐glycosylation. Utilizing rapidly accessible 1,6‐di‐OPTFAI glycosyl donors, TMSOTf‐catalyzed glycosylation occurred with excellent α‐selectivity and broad substrate scope, and the remaining 6‐OPTFAI group can be cleaved chemoselectively. The remote participation of 6‐OPTFAI is supported by the first characterization of the crucial 1,6‐bridged bicyclic oxazepinium ion intermediates by low‐temperature NMR spectroscopy. These cations were found to be relatively stable and mainly responsible for the present stereoselectivities. Further application is highlighted in glycosylation reactions toward trisaccharide heparins as well as the convergent synthesis of chacotriose derivatives using a bulky 2,4‐di‐O‐glycosylated donor.
Sr3[SnOSe3][CO3]: A Heteroanionic Nonlinear Optical Material Containing Planar π‐conjugated [CO3] and Heteroleptic [SnOSe3] Anionic Groups
Authors: Wang Jiankang , Cheng Yansong , Wu Hongping , Hu Zhanggui , Wang Jiyang , Wu Yicheng , Yu Hongwei
Published: March 2022

Inorganic heteroanionic materials are attracting increasing attention for exploring new nonlinear optical (NLO) materials because they could better satisfy the necessary but conflicting properties of NLO crystals, e.g. large SHG response and wide band‐gap. Up to now, the reports on heteroanionic NLO materials have mainly focused on ultraviolet or visible oxide‐based fluoroborates, fluorophosphates, borate‐phosphates and borate‐iodates. However, chalcogenides containing different kinds of anionic groups have barely been reported. Herein, we have synthesized the first oxychalcogenide‐carbonate, Sr3[SnOSe3][CO3] that contains two different kinds of anionic groups, [SnOSe3] and [CO3]. It crystallizes in a noncentrosymmetric space group and exhibits fascinating NLO properties, including a large SHG response (≈1×AGS), sufficient birefringence (0.12 @1064 nm), wide band‐gap (3.46 eV) and high laser damage threshold (240 MW cm−2). These make Sr3[SnOSe3][CO3] a promising NLO crystal.
Bifunctional WC‐Supported RuO2 Nanoparticles for Robust Water Splitting in Acidic Media
Authors: Sun Shu‐Chao , Jiang Hao , Chen Zi‐Yao , Chen Qing , Ma Ming‐Yuan , Zhen Liang , Song Bo , Xu Cheng‐Yan
Published: March 2022

We report the strong catalyst–support interaction in WC‐supported RuO2 nanoparticles (RuO2‐WC NPs) anchored on carbon nanosheets with low loading of Ru (4.11 wt.%), which significantly promotes the oxygen evolution reaction activity with a η10 of 347 mV and a mass activity of 1430 A gRu−1, eight‐fold higher than that of commercial RuO2 (176 A gRu−1). Theoretical calculations demonstrate that the strong catalyst–support interaction between RuO2 and the WC support could optimize the surrounding electronic structure of Ru sites to reduce the reaction barrier. Considering the likewise excellent catalytic ability for hydrogen production, an acidic overall water splitting (OWS) electrolyzer with a good stability constructed by bifunctional RuO2‐WC NPs only requires a cell voltage of 1.66 V to afford 10 mA cm−2. The unique 0D/2D nanoarchitectures rationally combining a WC support with precious metal oxides provides a promising strategy to tradeoff the high catalytic activity and low cost for acidic OWS applications.
Exovinylene Cyclic Carbonates: Multifaceted CO2‐Based Building Blocks for Modern Chemistry and Polymer Science
Authors: Ngassam Tounzoua Charlène , Grignard Bruno , Detrembleur Christophe
Published: March 2022

Carbon dioxide is a renewable, inexhaustible, and cheap alternative to fossil resources for the production of fine chemicals and plastics. It can notably be converted into exovinylene cyclic carbonates, unique synthons gaining momentum for the preparation of an impressive range of important organic molecules and functional polymers, in reactions proceeding with 100 % atom economy under mild operating conditions in most cases. This Review summarizes the recent advances in their synthesis with particular attention on describing the catalysts needed for their preparation and discussing the unique reactivity of these CO2‐based heterocycles for the construction of diverse organic building blocks and (functional) polymers. We also discuss the challenges and the future perspectives in the field.
Single‐Vesicle Electrochemistry Following Repetitive Stimulation Reveals a Mechanism for Plasticity Changes with Iron Deficiency
Authors: Wang Ying , Gu Chaoyi , Ewing Andrew G.
Published: March 2022

Deficiency of iron, the most abundant transition metal in the brain and important for neuronal activity, is known to affect synaptic plasticity, causing learning and memory deficits. How iron deficiency impacts plasticity by altering neurotransmission at the cellular level is not fully understood. We used electrochemical methods to study the effect of iron deficiency on plasticity with repetitive stimulation. We show that during iron deficiency, repetitive stimulation causes significant decrease in exocytotic release without changing vesicular content. This results in a lower fraction of release, opposite to the control group, upon repetitive stimulation. These changes were partially reversible by iron repletion. This finding suggests that iron deficiency has a negative effect on plasticity by decreasing the fraction of vesicular release in response to repetitive stimulation. This provides a putative mechanism for how iron deficiency modulates plasticity.