bluuebunny/crossref_metadata_2025 huggingface dataset:
Values of the Legendre chi and Hurwitz zeta functions at rational arguments
Authors: Cvijović Djurdje , Klinowski Jacek
Published: July 2002

We show that the Hurwitz zeta function,

ζ
(
ν
,
a
)

\zeta (\nu ,a)

, and the Legendre chi function,

χ
ν

(
z
)

\chi _\nu (z)

, defined by
\[
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="zeta left-parenthesis nu comma a right-parenthesis equals sigma-summation Underscript k equals 0 Overscript normal infinity Endscripts StartFraction 1 Over left-parenthesis k plus a right-parenthesis Superscript nu Baseline EndFraction comma 0 greater-than a less-than-or-equal-to 1 comma upper R e nu greater-than 1 comma">

ζ
(
ν
,
a
)
=

∑

k
=
0

∞

1

(
k
+
a

)
ν

,

0
>
a
≤
1
,
Re

ν
>
1
,

\zeta (\nu ,a)=\sum _{k=0}^\infty \frac {1}{(k+a)^\nu },\quad 0>a\le 1,\operatorname {Re}\,\nu >1,

\]
and
\[
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="chi Subscript nu Baseline left-parenthesis z right-parenthesis equals sigma-summation Underscript k equals 0 Overscript normal infinity Endscripts StartFraction z Superscript 2 k plus 1 Baseline Over left-parenthesis 2 k plus 1 right-parenthesis Superscript nu Baseline EndFraction comma StartAbsoluteValue z EndAbsoluteValue less-than-or-equal-to 1 comma upper R e nu greater-than 1 with nu equals 2 comma 3 comma 4 comma ellipsis comma">

χ
ν

(
z
)
=

∑

k
=
0

∞

z

2
k
+
1

(
2
k
+
1

)
ν

,

|

z

|

≤
1
,
Re

ν
>
1
with
ν
=
2
,
3
,
4
,
…
,

\chi _\nu (z)=\sum _{k=0}^\infty \frac {z^{2k+1}}{(2k+1)^\nu },\quad |z|\le 1,\operatorname {Re}\,\nu >1 \text {with} \nu =2,3,4,\dotsc ,

\]
respectively, form a discrete Fourier transform pair. Many formulae involving the values of these functions at rational arguments, most of them unknown, are obtained as a corollary to this result. Among them is the further simplification of the summation formulae from our earlier work on closed form summation of some trigonometric series for rational arguments. Also, these transform relations make it likely that other results can be easily recovered and unified in a more general context.
Genetic manipulation of carotenoid biosynthesis and photoprotection
Authors: Pogson Barry J. , Rissler Heather M.
Published: July 2002

There are multiple complementary and redundant mechanisms to provide protection against photooxidative damage, including non–photochemical quenching (NPQ). NPQ dissipates excess excitation energy as heat by using xanthophylls in combination with changes to the light–harvesting complex (LHC) antenna. The xanthophylls are oxygenated carotenoids that in addition to contributing to NPQ can quench singlet or triplet chlorophyll and are necessary for the assembly and stability of the antenna. We have genetically manipulated the expression of the ε–cyclase and β–carotene hydroxylase carotenoid biosynthetic enzymes inArabidopsis thaliana. The ε–cyclase overexpression confirmed thatlut2(lutein deficient) is a mutation in the ε–cyclase gene and demonstrated that lutein content can be altered at the level of mRNA abundance with levels ranging from 0 to 180% of wild–type. Also, it is clear that lutein affects the induction and extent of NPQ. The deleterious effects of lutein deficiency on NPQ inArabidopsisandChlamydomonasare additive, no matter what the genetic background, whethernpq1(zeaxanthin deficient), aba1 or antisense β–hydroxylase (xanthophyll cycle pool decreased). Additionally, increasing lutein content causes a marginal, but significant, increase in the rate of induction of NPQ despite a reduction in the xanthophyll cycle pool size.
Silk: molecular organization and control of assembly
Authors: Valluzzi R. , Winkler S. , Wilson D. , Kaplan D. L.
Published: July 2002

The interface between the science and engineering of biology and materials is an area of growing interest. One of the goals of this field is to utilize biological synthesis and processing of polymers as a route to gain insight into topics such as molecular recognition, self–assembly and the formation of materials with well–defined architectures. The biological processes involved in polymer synthesis and assembly can offer important information on fundamental interactions involved in the formation of complex material architectures, as well as practical knowledge into new and important materials related to biomaterial uses and tissue engineering needs. Classic approaches in biology, including genetic engineering, controlled microbial physiology and enzymatic synthesis, are prototypical methods used to control polymer structure and chemistry, including stereoselectivity and regioselectivity, to degrees unattainable using traditional synthetic chemistry. This type of control can lead to detailed and systematic studies of the formation of the structural hierarchy in materials and the subsequent biological responses to these materials.
Adaptive beamforming at very low frequencies in spatially coherent, cluttered noise environments with low signal-to-noise ratio and finite-averaging times
Authors: Nuttall Albert H. , Wilson James H.
Published: July 2002

Realistic simulations with spatially coherent noise have been run in order to compare the performance of adaptive beamforming (ABF), inverse beamforming (IBF), and conventional beamforming (CBF) for the case of finite-averaging times, where the actual spatial coherence of the acoustic field, or covariance matrix, is not known a priori, but must be estimated. These estimation errors cause large errors in the ABF estimate of the directionality of the acoustic field, partly because ABF is a highly nonlinear algorithm. In addition, it is shown that ABF is fundamentally limited in its suppression capability at very low frequency (VLF), based on the sidelobe level of the conventional beampattern in the direction of the noise interferer [G. L. Mohnkern, “Effects of Errors and Limitations on Interference Suppression,” NOSC Technical Document 1478, Naval Ocean Systems Center (1989)]. The simulations include a low-level plane wave signal of interest, a stronger noise plane wave interferer, and spatially random background noise. Both IBF and ABF performed significantly better than CBF, and IBF’s performance was slightly better than ABF’s performance. The performances of IBF and the ABF algorithm, the minimum variance distortionless response (MVDR) [A. H. Nuttall and D. W. Hyde, “Unified Approach to Optimum and Suboptimum Processing for Arrays,” USL Report Number 992, Naval Underwater Systems Center, New London, CT (22 April 1969)] were recently compared independently [J. S. D. Solomon, A. J. Knight, and M. V. Greening, “Sonar Array Signal Processing for Sparse Linear Arrays,” Defense Science and Technology Organization (DSTO) Technical Report (June 1999)] using measured data, with the result that IBF outperformed MVDR. This result is significant because MVDR requires orders of magnitude more processing power than IBF or CBF.
Performance of an adaptive beamforming noise reduction scheme for hearing aid applications. II. Experimental verification of the predictions
Authors: Kompis Martin , Dillier Norbert
Published: July 2002

A method to predict the amount of noise reduction which can be achieved using a two-microphone adaptive beamforming noise reduction system for hearing aids [J. Acoust. Soc. Am. 109, 1123 (2001)] is verified experimentally. 34 experiments are performed in real environments and 58 in simulated environments and the results are compared to the predictions. In all experiments, one noise source and one target signal source are present. Starting from a setting in a moderately reverberant room (reverberation time 0.42 s, volume 34 m3, distance between listener and either sound source 1 m, length of the adaptive filter 25 ms), eight different parameters of the acoustical environment and three different design parameters of the adaptive beamformer were systematically varied. For those experiments, in which the direct-to-reverberant ratios of the noise signal is +3 dB or less, the difference between the predicted and the measured improvement in signal-to-noise ratio (SNR) is −0.21±0.59 dB for real environments and −0.25±0.51 dB for simulated environments (average±standard deviation). At higher direct-to-reverberant ratios, SNR improvement is systematically underestimated by up to 5.34 dB. The parameters with the greatest influence on the performance of the adaptive beamformer have been found to be the direct-to-reverberant ratio of the noise source, the reverberation time of the acoustic environment, and the length of the adaptive filter.
Differences between sound scattering by weakly scattering spheres and finite-length cylinders with applications to sound scattering by zooplankton
Authors: Stanton Timothy K. , Wiebe Peter H. , Chu Dezhang
Published: July 2002

A modeling study was conducted to determine the conditions under which fluidlike zooplankton of the same volume but different shapes (spherical/cylindrical) have similar or dramatically different scattering properties. Models of sound scattering by weakly scattering spheres and cylinders of finite length used in this analysis were either taken from other papers or derived and herein adapted for direct comparison over a range of conditions. The models were examined in the very low- (ka≪1, kL≪1), moderately low- (ka≪1, kL≳1), and high-frequency regions (ka≫1, kL≫1), where k is the acoustic wave number, a is the radius (spherical or cylindrical) of the body, and L is the length of the cylinders (for an elongated body with L/a=10, “moderately low” corresponds to the range 0.1≲ka≲0.5). Straight and bent cylinder models were evaluated for broadside incidence, end-on incidence, and averages over various distributions of angle of orientation. The results show that for very low frequencies and for certain distributions of orientation angles at high frequencies, the averaged scattering by cylinders will be similar, if not identical, to the scattering by spheres of the same volume. Other orientation distributions of the cylinders at high frequencies produce markedly different results. Furthermore, over a wide range of orientation distributions the scattering by spheres is dramatically different from that of the cylinders in the moderately low-frequency region and in the Rayleigh/geometric transition region: (1) the Rayleigh to geometric scattering turning point occurs at different points for the two cases when the bodies are constrained to have the same volume and (2) the functional dependence of the scattering levels upon the volume of the bodies in the moderately low-frequency region is quite often different between the spheres and cylinders because of the fact that the scattering by the cylinders is still directional in this region. The study demonstrates that there are indeed conditions under which different shaped zooplankton of the same volume will yield similar (ensemble average) scattering levels, but generally the shape and orientation distribution of the elongated bodies must be taken into account for accurate predictions.
Distortion product otoacoustic emissions in human newborns and adults. I. Frequency effects
Authors: Lasky Robert E.
Published: July 2002

This study varied stimulus frequency and recorded distortion product otoacoustic emissions (DPOAEs) in human newborns and adults. Because of outer and middle ear acoustics, the same auditory input resulted in higher newborn stimulus sound pressure levels across a broad frequency range in the occluded outer ear canal. Noise levels in the canal were 5–15 dB lower for adults at frequencies less than about 3 kHz. The 2 f1−f2 DPOAE was the most reliably recorded DPOAE except at the lowest frequencies assessed. At the lowest frequencies the 2 f2−f1 DPOAE was more frequently recorded than any other DPOAE. There were no striking developmental differences in the kinds of DPOAEs that were recorded. The amplitudes of consecutively recorded 2 f1−f2 DPOAEs were generally within 1.5 dB of each other for all age groups (slightly better reproducibility for adults than newborns). The phases of consecutively recorded 2 f1−f2 DPOAEs were generally within 15 degrees of each other (often less than 10 and 5 degrees for newborns and adults respectively). At the highest frequencies assessed (f2=4.2–9.9 kHz) all subjects had similar amplitude 2 f1−f2 DPOAEs. At lower frequencies adult 2 f1−f2 amplitudes were significantly less than those of newborns. At the lowest frequencies reliably assessed (f2=1.5–2.1 kHz) term newborns had significantly larger 2 f1−f2 DPOAEs than preterm newborns. Newborn and adult 2 f1−f2 DPOAE amplitude X f2/f1 functions were quite similar although there were reliable differences. Age related differences in the outer and middle ears may explain some of the differences in DPOAEs that were observed.
The second-harmonic generation of a conical sound source
Authors: Ding Desheng , Liu Xiaojun
Published: July 2002

The second-harmonic sound beam nonlinearly generated by a conical source is analytically described. It is shown that the radial second-harmonic beam is distributed as the Bessel function and independent of the propagation distance. Another important feature is that the beamwidth of the second-harmonic component is just equal to 1/2 times that of the fundamental, not 1/√ times in the general cases. A potential application of this beam in the acoustic nonlinearity parameter B/A imaging or measurement is also discussed.
Gap detection in single- and multiple-channel stimuli by LAURA cochlear implantees
Authors: van Wieringen Astrid , Wouters Jan
Published: July 2002

Gap-detection thresholds were determined for different complex patterns of electrical stimulation in four postlingually deafened LAURA cochlear implantees, to examine the nature of within- and across-channel auditory processes in more detail. Gap detectability was examined as a function of stimulus complexity (one, two, or three channels), channel distance within and across multichannel pre- and post-gap markers, stimulus asymmetry, and pulse rate. All markers roved in duration from 200 to 500 ms to ensure that subjects were not using overall stimulus duration as a cue. Gap-detection thresholds for all subjects were short (<5 ms) when the pre- and post-gap markers stimulated the same single or multiple channels, even when the distance between simultaneously stimulated channels was large (exp. 1). For some subjects, gap detectability was more difficult in the across-channel condition, when the pre- and post-gap markers each stimulated different channels, although performance improved substantially in most subjects after extensive training (exp. 2). Additional tests with random maskers also suggest that neural interaction only affects performance mildly, and that the magnitude of the gap-detection threshold probably depends more on the subject’s cognitive (in)ability to attend to the temporal gap than on the temporal acuity of their auditory system. Other stimulus conditions showed a difference in performance related to the order of the markers: gap thresholds were longer when the pre-gap marker stimulated one channel and the post-gap marker stimulated two or more channels, than vice versa (exp. 3). In addition, gap thresholds of three of the subjects increased with decreasing pulse rate from 1250 to 400 pps, a finding which may be related to the rate of the speech processing strategies used by each individual implantee (exp. 4).
One-dimensional phenomenological model of hysteresis. I. Development of the model
Authors: Piquette Jean C. , Forsythe Stephen E.
Published: July 2002

A one-dimensional phenomenological model of hysteresis is presented. The model is suitable for application both to electrostrictive materials, such as lead magnesium niobate (PMN), and to magnetostrictive materials, such as Terfenol D. The concepts of “inflation,” “field space,” and the “reference ellipse” are introduced as suitable mechanisms for transforming measured hysteretic data into corresponding anhysteretic versions. An anhysteretic model is then fitted (in the least-squares sense) to the transformed data. By applying the inverse transforms to the fitted anhysteretic model, a hysteretic model is deduced. Good agreement with the original (hysteretic) data is seen. It is shown that, when a sample is driven by a monofrequency electric field, the area of the polarization vs electric-field hysteresis loop is independent of all harmonics in the polarization but the first. A principle useful for understanding the shapes assumed by P–E and M–H hysteresis loops in general is described.
A stable ‘‘island’’ in the slip-stick region of linear low-density polyethylene
Authors: Pudjijanto Stephanus , Denn Morton M.
Published: July 2002

A stable ‘‘island’’ has been discovered in the slip-stick region of a linear low-density polyethylene. Within this region, which exists only in a narrow temperature range, pressure oscillations cease, the pressure drop falls by a substantial amount, and the extrudate becomes reasonably smooth. Unstable oscillating flow persists at throughputs on both sides of this island. The existence of this intermediate stable flow challenges all current theories of extrusion instabilities. The phenomenon resembles observations of a drop in extrusion pressure for which a mesophase transition has been suggested.
Analysis of Failure Rates for COVID-19 Entrance Screening at a US Academic Medical Center
Authors: Roberts Scott C. , Faruq Ridwan N. , Wilkinson Anne K. , Pashankar Dinesh S. , Russi Mark , Khokhar Babar , Martinello Richard A.
Published: November 2022

This quality improvement study analyzes the rate of failures in entrance screening for COVID-19 among individuals entering a large academic medical center.
Findings From Severe Maternal Morbidity Surveillance and Review in Maryland
Authors: Wolfson Carrie , Qian Jiage , Chin Pamela , Downey Cathy , Mattingly Katie Jo , Jones-Beatty Kimberly , Olaku Joanne , Qureshi Sadaf , Rhule Jane , Silldorff Danielle , Atlas Robert , Banfield Anne , Johnson Clark T. , Neale Donna , Sheffield Jeanne S. , Silverman David , McLaughlin Kacie , Koru Güneş , Creanga Andreea A.
Published: November 2022

Importance

In the US, more than 50 000 women experience severe maternal morbidity (SMM) each year, and the SMM rate more than doubled during the past 25 years. In response, professional organizations called for birthing facilities to routinely identify and review SMM events and identify prevention opportunities.

Objective

To examine SMM levels, primary causes, and factors associated with the preventability of SMM using Maryland’s SMM surveillance and review program.

Design, Setting, and Participants

This cross-sectional study included pregnant and postpartum patients at 42 days or less after delivery who were hospitalized at 1 of 6 birthing hospitals in Maryland between August 1, 2020, and November 30, 2021. Hospital-based SMM surveillance was conducted through a detailed review of medical records.

Exposures

Hospitalization during pregnancy or within 42 days post partum.

Main Outcomes and Measures

The main outcomes were admission to an intensive care unit, having at least 4 U of red blood cells transfused, and/or having COVID-19 infection requiring inpatient hospital care.

Results

A total of 192 SMM events were identified and reviewed. Patients with SMM had a mean [SD] age of 31 [6.49] years; 9 [4.7%] were Asian, 27 [14.1%] were Hispanic, 83 [43.2%] were non-Hispanic Black, and 68 [35.4%] were non-Hispanic White. Obstetric hemorrhage was the leading primary cause of SMM (83 [43.2%]), followed by COVID-19 infection (57 [29.7%]) and hypertensive disorders of pregnancy (17 [8.9%]). The SMM rate was highest among Hispanic patients (154.9 per 10 000 deliveries), primarily driven by COVID-19 infection. The rate of SMM among non-Hispanic Black patients was nearly 50% higher than for non-Hispanic White patients (119.9 vs 65.7 per 10 000 deliveries). The SMM outcome assessed could have been prevented in 61 events (31.8%). Clinician-level factors and interventions in the antepartum period were most frequently cited as potentially altering the SMM outcome. Practices that were performed well most often pertained to hospitals’ readiness and adequate response to managing pregnancy complications. Recommendations for care improvement focused mainly on timely recognition and rapid response to such.

Conclusions and Relevance

The findings of this cross-sectional study, which used hospital-based SMM surveillance and review beyond the mere exploration of administrative data, offers opportunities for identifying valuable quality improvement strategies to reduce SMM. Immediate strategies to reduce SMM in Maryland should target its most common causes and address factors associated with preventability identified at individual hospitals.
Into the Future of Pediatric Trauma and Critical Care Science
Authors: Dixon Cinnamon A. , Jenkins Tammara , Maholmes Valerie
Published: November 2022

This Viewpoint describes the scientific mission of the Pediatric Trauma and Critical Illness Branch of the Eunice Kennedy Shriver National Institute of Child Health and Human Development for research on pediatric trauma and critical illness.
The effect of microlevel and macrolevel signaling on learning with 360° videos
Authors: Beege Maik , Nebel Steve , Schneider Sascha , Rey Günter Daniel
Published: November 2022

The application of 360° videos raised the attention of educators and researchers, as it appears to be an approachable option to mediate complete environments in educational settings. However, challenges emerge from the perspective of educational psychology. Learning irrelevant cognitive strains might be imposed because it is necessary to navigate through spherical material. However, these potential downsides could be compensated for using signaling techniques. In a two (macrolevel vs. no macrolevel signaling) × two (microlevel vs. no microlevel signaling) factorial between‐subjects design plus control group, 215 fifth‐and sixth‐grade students will watch a 360° video about visual and behavioral characteristics of animals. Learning outcomes, cognitive load, disorientation, and presence will be investigated. It is expected that macrolevel signaling will enhance learning and presence and reduce cognitive load and disorientation. Microlevel signaling will have comparable advantages, but these effects will be more pronounced when macrolevel signaling is implemented.
Command filter‐based adaptive neural network controller design for uncertain nonsmooth nonlinear systems with output constraint
Authors: Xu Qian , Zong Guangdeng , Chen Yunjun , Niu Ben , Shi Kaibo
Published: November 2022

This paper investigates the command filter‐based adaptive neural network tracking control problem for uncertain nonsmooth nonlinear systems. First, an integral barrier Lyapunov function is introduced to deal with the symmetric output constraint and make the output comply with prescribed restrictions. Second, by the Filippov's differential inclusion theory and approximation theorem, the considered nonsmooth nonlinear system is converted to an equivalent smooth nonlinear system. Third, the Levant's differentiator is used to deal with the “explosion of complexity” problem. An error compensation mechanism is established to attenuate the effect of the filtering error on control performance. Then, an adaptive neural network controller is set up by resorting to the backstepping technique. It is strictly mathematically proved that the tracking error can converge to an arbitrarily small neighborhood of the origin and all the signals in the closed‐loop system are semi‐globally uniformly ultimately bounded. Finally, a numerical example and an application example of the robotic manipulator system are provided to demonstrate the availability of the proposed control strategy.
Nanosonosensitizer‐Augmented Sono‐Immunotherapy for Glioblastoma by Non‐Invasive Opening of the Blood–Brain Barrier
Authors: Lin Danmin , Wang Zhen , Long Wei , Xu Mingze , Liu Aolu , Gao Yifei , Wen Zhu , Liu Chao , He Jiecheng , Cheng Yuxue , Jiang Siyuan , Chen Jiapeng , Liu Qingpeng , Zhang Lingkun , You Rong , Yin Liang , Guan Yanqing
Published: November 2022

The presence of blood–brain barrier (BBB) that limits effective penetration of therapeutics is the main reason for poor outcomes of glioblastoma (GBM) treatment. Ultrasound (US) combined with microbubbles (MBs) can precisely disrupt the tight junctions of brain endothelial cells, thus creating “acoustic pores” and non‐invasive opening the BBB. Here, chitosan oligosaccharide (COS) is conjugated with a sonosensitizer protoporphyrin IX (PpIX) and an immune‐enhancing adjuvant Poly(I:C) via electrostatic adsorption, and cross‐linked with a tumor‐targeting molecule hyaluronic acid (HA) affording nanosonosensitizers HA‐Poly(I:C)/COS‐PpIX (abbreviated as “HP/CP” NSs). HP/CP NSs can target and penetrate GBMs, and trigger reactive oxygen species production upon US, simultaneously causing mitochondrial dysfunction and DNA damage. Tumor‐associated antigens released by sonodynamic therapy‐induced immunogenic cell death and loaded Poly(I:C) form an in situ vaccine together to potentiate antitumor immune responses. In orthotopic GBM mice models, the HP/CP+US treatments prolong mice survival, enhance cytotoxic T‐lymphocytes infiltration, and activate peripheral immune circulation. Besides, HP/CP NSs possess favorable biosafety profiles. Collectively, this study sheds light on the application of HP/CP NSs for synergistic sono‐immunotherapy of GBMs after non‐invasive opening of the BBB.
Segregated and Non‐Settling Liquid Metal Elastomer via Jamming of Elastomeric Particles
Authors: Xue Xiaoting , Zhang Dongguang , Wu Yali , Xing Ruizhe , Li Hong , Yu Tingting , Bai Bowen , Tao Yebo , Dickey Michael D. , Yang Jiayi
Published: November 2022

Liquid metal elastomer (LME)—that is, liquid metal particles dispersed in elastomer—is a soft material that has useful electric, dielectric, and thermal properties. Two issues with LME are sought to be addressed: 1) the dense liquid metal (LM) particles can settle before curing of the elastomer, and 2) the LM particles are separated by a thin layer of insulating elastomer and therefore require some “mechanical sintering” to break this layer to create conductive paths. These issues are addressed using an LME containing elastic particles (LMEP). Elastic polydimethylsiloxane particles (PPs) and LM particles jam to prevent particle settling. Meanwhile, the PPs reduce the loading necessary to create conductive paths, thus decreasing the density and cost relative to LME. Surprisingly, the particles percolate into conductive paths prior to curing the LMEP but not in LME. The dielectric constant, electrical conductivity, and thermal conductivity of LMEPs are investigated by changing the volume fraction of LM particles, polydimethylsiloxane pre‐polymer and PPs, and propose an LMEP with the optimal ratio. In addition, LMEP‐based sensors and circuits are demonstrated for wearable electronics.
Panoramic Mapping of Phonon Transport from Ultrafast Electron Diffraction and Scientific Machine Learning
Authors: Chen Zhantao , Shen Xiaozhe , Andrejevic Nina , Liu Tongtong , Luo Duan , Nguyen Thanh , Drucker Nathan C. , Kozina Michael E. , Song Qichen , Hua Chengyun , Chen Gang , Wang Xijie , Kong Jing , Li Mingda
Published: November 2022

One central challenge in understanding phonon thermal transport is a lack of experimental tools to investigate frequency‐resolved phonon transport. Although recent advances in computation lead to frequency‐resolved information, it is hindered by unknown defects in bulk regions and at interfaces. Here, a framework that can uncover microscopic phonon transport information in heterostructures is presented, integrating state‐of‐the‐art ultrafast electron diffraction (UED) with advanced scientific machine learning (SciML). Taking advantage of the dual temporal and reciprocal‐space resolution in UED, and the ability of SciML to solve inverse problems involving coupled Boltzmann transport equations, the frequency‐dependent interfacial transmittance and frequency‐dependent relaxation times of the heterostructure from the diffraction patterns are reliably recovered. The framework is applied to experimental Au/Si UED data, and a transport pattern beyond the diffuse mismatch model is revealed, which further enables a direct reconstruction of real‐space, real‐time, frequency‐resolved phonon dynamics across the interface. The work provides a new pathway to probe interfacial phonon transport mechanisms with unprecedented details.
Complex Living Materials Made by Light‐Based Printing of Genetically Programmed Bacteria
Authors: Binelli Marco R. , Kan Anton , Rozas Luis E. A. , Pisaturo Giovanni , Prakash Namita , Studart André R.
Published: November 2022

Living materials with embedded microorganisms can genetically encode attractive sensing, self‐repairing, and responsive functionalities for applications in medicine, robotics, and infrastructure. While the synthetic toolbox for genetically engineering bacteria continues to expand, technologies to shape bacteria‐laden living materials into complex 3D geometries are still rather limited. Here, it is shown that bacteria‐laden hydrogels can be shaped into living materials with unusual architectures and functionalities using readily available light‐based printing techniques. Bioluminescent and melanin‐producing bacteria are used to create complex materials with autonomous chemical‐sensing capabilities by harnessing the metabolic activity of wild‐type and engineered microorganisms. The shaping freedom offered by printing technologies and the rich biochemical diversity available in bacteria provides ample design space for the creation and exploration of complex living materials with programmable functionalities for a broad range of applications.
Electropneumatic Surfaces: Pairing Electrowetting and Air Pressure for Reversible Droplet Mobility Switching
Authors: Markodimitrakis Ioannis E. , Vourdas Nikolaos , Papathanasiou Athanasios G.
Published: November 2022

Designing surfaces with controllable wettability and exploring methodologies for manipulating liquid motion on solid surfaces is an important research challenge. The impact on various interdisciplinary applications, ranging from self‐cleaning technology to the handling of droplets on Lab‐on‐a‐Chip self‐diagnostic devices, is expected to be significant. In this work, it is studied how the combined action of electric fields and pneumatic actuation can be used to achieve wetting transitions from states where droplets stick to surfaces, to states where droplets slide easily with low friction. The manipulation of water droplets on air‐permeable porous surfaces using both electric fields (electrowetting) and air‐pressure is investigated. The control over droplet mobility is achieved by tuning the solid‐liquid adhesion upon voltage application, in order to pin the droplet; de‐pinning is achieved by air pressure application through surface pores. This way low energy consumption and efficient switching between extreme wetting states and droplet mobility are realized.
In Vivo Anchoring Bis‐Pyrene Probe for Molecular Imaging of Early Gastric Cancer by Endoscopic Techniques
Authors: Luo Qiang , Fan Chaoqiang , Ying Wang , Peng Xue , Hu Yiyang , Luan Zhaohui , Ye Shaosong , Gong Chunli , Huang Yu , Xiao Yufeng , Chen Yang , Xing Malcolm , Wang Lei , Yang Shiming
Published: November 2022

With the development of blue laser endoscopy (BLE) technique, it's often used to diagnose early gastric cancer (EGC) by the morphological changes of blood vessels through BLE. However, EGC is still not obvious to identify, resulting in a high rate of missed diagnosis. Molecular imaging can show the changes in early tumors at molecular level, which provides a possibility for diagnosing EGC. Therefore, developing a probe that visually monitors blood vessels of EGC under BLE is particularly necessary. Herein, a bis‐pyrene (BP) based nanoprobe (BP‐FFVLK‐(PEG)‐RGD, M1) is designed, which can target angiogenesis and self‐assemble into fibers in situ, resulting in stable and long‐term retention in tumor. Moreover, M1 probe can emit yellow‐green fluorescence for imaging under BLE. M1 probe is confirmed to steadily remain in tumor for up to 96 hours in mice transplanted subcutaneously. In addition, the M1 probe is able to target angiogenesis for molecular imaging of isolated human gastric cancer tissue under BLE. Finally, M1 probe i.v. injected into primary gastric cancer model rabbits successfully highlighted the tumor site under BLE, which is confirmed by pathological analysis. It's the first time to develop a probe for diagnosing EGC by visualizing angiogenesis under BLE, showing great clinical significance.
Multiplexed Complementary Signal Transmission for a Self‐Regulating Artificial Nervous System
Authors: Choi Young Jin , Roe Dong Gue , Choi Yoon Young , Kim Seongchan , Jo Sae Byeok , Lee Hwa Sung , Kim Do Hwan , Cho Jeong Ho
Published: November 2022

Neuromorphic engineering has emerged as a promising research field that can enable efficient and sophisticated signal transmission by mimicking the biological nervous system. This paper presents an artificial nervous system capable of facile self‐regulation via multiplexed complementary signals. Based on the tunable nature of the Schottky barrier of a complementary signal integration circuit, a pair of complementary signals is successfully integrated to realize efficient signal transmission. As a proof of concept, a feedback‐based blood glucose level control system is constructed by incorporating a glucose/insulin sensor, a complementary signal integration circuit, an artificial synapse, and an artificial neuron circuit. Certain amounts of glucose and insulin in the initial state are detected by each sensor and reflected as positive and negative amplitudes of the multiplexed presynaptic pulses, respectively. Subsequently, the pulses are converted to postsynaptic current, which triggered the injection of glucose or insulin in a way that confined the glucose level to a desirable range. The proposed artificial nervous system demonstrates the notable potential of practical advances in complementary control engineering.
Revealing Photodegradation Pathways of Organic Solar Cells by Spectrally Resolved Accelerated Lifetime Analysis
Authors: Weitz Paul , Le Corre Vincent Marc , Du Xiaoyan , Forberich Karen , Deibel Carsten , Brabec Christoph J. , Heumüller Thomas
Published: November 2022

A method for organic solar cell (OSC) stability testing is presented that aims to provide more unique insight into the causes of degradation patterns of OSCs. The method involves using monochromatic light at high irradiation doses to accelerate isolated degradation mechanisms while monitoring the device with a series of in‐situ steady‐state and transient electrical measurements. The experimental results are accompanied by drift‐diffusion simulations to localize degradation pathways. PM6:Y6‐based OSCs are tested, which are known to show a rather broad range of lifetimes as a function of device architecture, material batches, or degradation conditions. The experiments reveal a degradation mechanism that causes an increased trap‐state density inside the PM6:Y6 layer. The transient simulations suggest that these states are formed at or around the interface between the PM6:Y6 and the electron transport layer. Furthermore, the surprisingly dominant impact of the illuminating wavelength on the degradation pattern is evidenced. Lastly, the degradation rate of the devices scales linearly with light intensity, making high intensity and spectrally selective degradation the most promising way to accelerate stability testing for the faster development of stable OSCs.
A Mechanistic and Quantitative Understanding of the Interactions between SiO and Graphite Particles
Authors: Gao Xiang , Li Suli , Xue Jiachen , Hu Dianyang , Xu Jun
Published: November 2022

SiO, comprised of silicon and silicon dioxides (SiO2), is one of the most commercially promising anode materials to mix with current widely used graphite for the high energy density lithium‐ion batteries (LIBs). One of the major bottlenecks for SiO/Graphite (SiO/Gr) composite anode is the cyclability due to considerable stress and strain (deformation) caused within and among the composite particles. However, a sophisticated and quantitative understanding of the highly electrochemical–mechanical coupling behaviors is still lacking. Herein, an electro–chemo–mechanical model with a detailed geometric description to quantitatively reveal the underlying governing mechanisms of SiO/Gr composite anodes using the half‐cell configuration is established and validated. Results show that an 8–10 wt.% of SiO is an optimal choice regarding capacity delivery and minimizing Li plating under 1C constant current charging condition. Positioning SiO particles near the separator and reducing the sizes of SiO particles are also demonstrated to be beneficial for electrochemical performance with trivial influence on mechanical mismatch. This study highlights a promising multiphysics model for the design and evaluation of next‐generation batteries and unlocks the mechanistic and quantitative understanding of the interactions among composite particles in electrodes.
Revisiting the Role of Hydrogen in Lithium‐Rich Antiperovskite Solid Electrolytes: New Insight in Lithium Ion and Hydrogen Dynamics
Authors: Ling Sifan , Deng Bei , Zhao Ruo , Lin Haibin , Kong Long , Zhang Ruiqin , Lu Zhouguang , Bian Juncao , Zhao Yusheng
Published: November 2022

Li2OHX(X= Cl or Br) with an antiperovskite structure possess the advantages of low melting point, low cost, and ease of scaling‐up, which show great promise for applications in all‐solid‐state Li metal batteries (ASSLMBs). However, Li‐ion transport mechanisms in Li2OHXare still debated and the influence of H on the electrochemical performance of Li2OHXis yet to be explored. Herein, combining the theoretical calculations and experimental measurements, it is found that H affects Li‐ion transport, crystal stability, electrochemical stability, and electronic conductivity of Li2OHX. Compared with H‐free Li3OCl, although H helps to generate vacancy‐like defects, the electrostatic repulsive force between H and Li‐ion leads to an increase in both the activation energy and the diffusion length (space compensation effect), resulting in special Li ion transport trajectories along the Li‐O plane. Decreasing H content reduces the electronic conductivity and enhances the reduction‐resistant ability of Li2OHX, promoting the cycling stability and rate performance of Li∣Li2OHX∣Li symmetric cells and the ASSLMBs. This work delivers a new insight into the role of H in antiperovskite Li2OHXand can serve as guidance for solid electrolyte design.
Dual‐Site Functionalization on Supported Metal Monolayer Electrocatalysts for Selective CO2 Reduction
Authors: Zhao Zhonglong , Lu Gang
Published: November 2022

Development of efficient catalysts for electrochemical carbon dioxide reduction reaction (CO2RR) represents a great challenge in renewable energy research. Although noble metals have long been explored as catalysts for CO2RR, their reactivity and selectivity remain rather low owing to the competing hydrogen evolution reaction (HER). Here, this work proposes that noble metal monolayers (MLs) supported by transition metal carbides (TMCs) and nitrides (TMNs) can become exceptional CO2RR catalysts with much suppressed HER. This work shows that there is a direct, antibonding interaction between the hydrogen adsorbate and the TMC/TMN substrates, while such interactions between CO2RR intermediates and the substrates are absent. This difference enables dual‐site functionalization of the ML catalysts, which circumvents the energy scaling relations dictating the competition between CO2RR and HER. Consequently, it is possible to reduce the binding of the H adsorbate to suppress HER and simultaneously increase the binding of CO2RR intermediates to boost the CO2RR. This work identifies several Ag and Au‐based catalysts that are thermodynamically and electrochemically stable and exhibit high activity and selectivity toward the production of formic acid. In addition, this work predicts that higher order CO2RR products including methanol and ethylene can also be produced on selected catalysts.
Pulse High Temperature Sintering to Prepare Single‐Crystal High Nickel Oxide Cathodes with Enhanced Electrochemical Performance
Authors: Huang Hao , Zhang Lipeng , Tian Huayang , Yan Junqing , Tong Junfan , Liu Xiaohang , Zhang Haoxuan , Huang Heqin , Hao Shu‐meng , Gao Jian , Yu Le , Li Hong , Qiu Jieshan , Zhou Weidong
Published: November 2022

For the currently most dominant cathode of Li(NixCoyMnz)O2(NCM, x + y + z = 1) in lithium‐ion batteries, higher nickel content brings higher energy density but is accompanied by heavier interfacial reactions with electrolyte and worse safety performance. Single crystal cathode materials have the advantages of fewer grain boundaries, higher density, and greatly suppressed microcracks during cycling, these benefits in turn suppress interfacial side reactions, as well as the improve volumetric energy density and safety performance. Here, a strategy of pulse high‐temperature sintering (PHTS) is reported to prepare single‐crystal Li(Ni0.9Co0.05Mn0.05)O2 (SC‐NCM90), in which an extra PHTS at 1040 °C for 1 min is added in the traditional calcination process at 750 °C, yielding well defined octahedral particles with an initial capacity of 209 mAh g−1. Compared with the counterpart NCM90 secondary spheres, the tap density of SC‐NCM90 increases by 1/3 to 2.76 g cm−3 and the microcracks are successfully suppressed, improving both the cycling performance and thermal stability. The calcination time and temperature are optimized, showing that overlong time or overhigh temperature of the PHTS treatment would result in particles with better defined octahedral shape but heavier Li/Ni intermixing and capacity loss.
Duration of employment within occupations and incident stroke in a US general population cohort 45 years of age or older (REGARDS study)
Authors: Huynh Tran B. , McClure Leslie A. , Howard Virginia J. , Stafford Monika M. , Judd Suzanne E. , Burstyn Igor
Published: November 2022

Background

The work environment can contribute to the risk of cardiovascular diseases (CVD) including stroke. Our objective was to identify occupations with elevated risk of stroke within the Reasons for Geographic and Racial Differences in Stroke (REGARDS) cohort.

Methods

We analyzed incident stroke outcomes (ischemic and hemorrhagic strokes) from 2003 to 2020 and employment characteristics of 13,659 adults aged ≥45 years enrolled in a national population‐based cohort study. Using a modified Poisson regression approach, we estimated the relative risks (RRs) and the associated 95% confidence intervals (CI) of stroke in relation to years of employment within each occupation coded using the US Census two‐digit Standard Occupation Code. Models were adjusted for Framingham Stroke Risk Score, region, race, age, and body mass index. We conducted stratified analysis by sex, employment time period (pre‐1975 vs. post‐1975), and region.

Results

Workers in the following occupations had a greater risk of stroke with longer duration of employment (per decade): protective service (RR: 2.35, 95% CI: 1.11, 4.97), food preparation and service (RR: 1.51, 95% CI: 1.05, 2.19), and transportation and material moving (RR: 1.30, 95% CI: 1.00, 1.69). The stroke risk in these occupations was disproportionately elevated in men, and differed by region and employment time period.

Conclusions

Longer employment in protective service, food preparation and serving, and transportation and materials moving occupations may increase the risk of stroke. Surveillance may uncover specific work‐related risk factors in these occupations, leading to interventions to reduce the burden of stroke among US workers.
Personal social networks of people with Down syndrome
Authors: Skotko Brian G. , Krell Kavita , Haugen Kelsey , Torres Amy , Nieves Amber , Dhand Amar
Published: November 2022

Studies in the neurotypical population have demonstrated that personal social networks can mitigate cognitive decline and the development of Alzheimer disease. To assess whether these benefits can also be extended to people with Down syndrome (DS), we studied whether and how personal networks can be measured in this population. We adapted a personal networks instrument previously created, validated, and implemented for the neurotypical population. We created two versions of the survey: one for participants with DS, ages 25 and older, and another for their study partners, who spent a minimum of 10 h/wk in a caregiver role. Participants with DS gave concordant data to those of study partners. Their personal networks included a median network size of 7.50, density 0.80, constraint 46.00, and effective size 3.07. Personal networks were composed of 50% kin, 80% who live within 15 miles, and 80% who eat a healthy diet. In this proof‐of‐principle study, we demonstrated that the personal networks of people with DS can be quantitatively analyzed, with no statistical difference between self‐report and parent‐proxy report. Future research efforts can now evaluate interventions to enhance personal networks for preventing Alzheimer disease in this population.
Five Strategies Dispute Resolvers Can Use to Vet Professional Guidance and Prevent Misconduct
Authors: Berstein Dan
Published: November 2022

As social justice movements continue growing, there are increasing calls for accountability when it comes to published materials.
Expanding the Toolbox of Target Directed Bio‐Orthogonal Synthesis: In Situ Direct Macrocyclization by DNA Templates
Authors: Chaudhuri Ritapa , Prasanth Thumpati , Dash Jyotirmayee
Published: November 2022

Herein, we demonstrate for the first time that noncanonical DNA can direct macrocyclization‐like challenging reactions to synthesize gene modulators. The planar G‐quartets present in DNA G‐quadruplexes (G4s) provide a size complementary reaction platform for the bio‐orthogonal macrocyclization of bifunctional azide and alkyne fragments over oligo‐ and polymerization. G4s immobilized on gold‐coated magnetic nanoparticles have been used as target templates to enable easy identification of a selective peptidomimetic macrocycle. Structurally similar macrocycles have been synthesized to understand their functional role in the modulation of gene function. The innate fluorescence of the in situ formed macrocycle has been utilized to monitor its cellular localization using a G4 antibody and its in cell formation from the corresponding azide and alkyne fragments. The successful execution of in situ macrocyclization in vitro and in cells would open up a new dimension for target‐directed therapeutic applications.
Manipulating OH−‐Mediated Anode‐Cathode Cross‐Communication Toward Long‐Life Aqueous Zinc‐Vanadium Batteries
Authors: Liu Dao‐Sheng , Zhang Zhaoyu , Zhang Yufei , Ye Minghui , Huang Song , You Shunzhang , Du Zijian , He Jiangfeng , Wen Zhipeng , Tang Yongchao , Liu Xiaoqing , Li Cheng Chao
Published: November 2022

The anode‐cathode interplay is an important but rarely considered factor that initiates the degradation of aqueous zinc ion batteries (AZIBs). Herein, to address the limited cyclability issue of V‐based AZIBs, Al2(SO4)3 is proposed as decent electrolyte additive to manipulate OH−‐mediated cross‐communication between Zn anode and NaV3O8 ⋅ 1.5H2O (NVO) cathode. The hydrolysis of Al3+ creates a pH≈0.9 strong acidic environment, which unexpectedly prolongs the anode lifespan from 200 to 1000 h. Such impressive improvement is assigned to the alleviation of interfacial OH− accumulation by Al3+ adsorption and solid electrolyte interphase formation. Accordingly, the strongly acidified electrolyte, associated with the sedated crossover of anodic OH− toward NVO, remarkably mitigate its undesired dissolution and phase transition. The interrupted OH−‐mediated communication between the two electrodes endows Zn||NVO batteries with superb cycling stability, at both low and high scan rates.