bluuebunny/crossref_metadata_2025 huggingface dataset:
A new formalism for wave scattering from a bounded obstacle
Authors: Misici Luciano , Pacelli Graziella , Zirilli Francesco
Published: July 2002

Let Ω⊂R3 be an obstacle that is a simply connected bounded domain. The exterior Dirichlet problem for the Helmholtz equation in R3\Ω with the Sommerfeld radiation condition at infinity is considered. Based on an integral representation formula, a new method to compute the solution of the exterior boundary value problem mentioned above is proposed. This method generalizes the formalism introduced for an unbounded obstacle by Milder [J. Acoust. Soc. Am. 89, 529–541 (1991)] and consists in computing a perturbation series whose coefficients are integrals. These integrals are independent one from the other so that the computation of the series is fully parallelizable. Finally, some numerical results obtained on test problems are shown. In particular, numerical experiments for obstacles with nonsmooth boundaries such as polyhedra and obstacles with multiscale corrugations are shown.
Adaptation of 2f1–2f2 distortion product otoacoustic emission in young-adult and old CBA and C57 mice
Authors: Sun X.-M. , Kim D. O.
Published: July 2002

The phenomenon of efferent-mediated adaptation of 2f1–f2 distortion product otoacoustic emission (DPOAE) was investigated in two strains (CBA/JNia and C57BL/6JNia) of mice of various ages using stimuli presented monaurally or binaurally. The present study demonstrated the existence of the DPOAE adaptation phenomenon in mice analogous to that previously reported in cats. The present data were fitted with one- or two-exponential functions. With a one-exponential fit in 2-month old mice, the adaptation magnitude ranged from 0 to 4 dB with the average value of 0.5 to 1.6 dB and the average time constant was 0.5 to 2.3 s. With a two-exponential fit, the shorter time constant was 0.3 to 1.7 s. The adaptation magnitude and time constant were similar between the monaural and binaural stimulations. We observed that there was a statistically significant decrease of adaptation magnitude in older CBA mice with age-related hearing loss when compared with young adult mice. The results from the young adult mice should be useful in future studies, e.g., a study of developmental changes in post-natal mice, or changes accompanying an alteration in the central auditory system arising from any etiology. We suggest that this phenomenon can be used as a tool for advancing basic knowledge of the auditory system and for assessing an impairment of the olivocochlear system, e.g., in aging.
Circumferential waves on an immersed, fluid-filled elastic cylindrical shell
Authors: Bao X. L. , Raju P. K. , Überall H.
Published: July 2002

The existence of various types of circumferential waves, both predominantly shell or fluid borne, and the repulsion of their dispersion curves is discussed here for an infinite, thin elastic, circular-cylindrical shell immersed in a fluid and filled with another fluid. The study is based on an analytic calculation of the partial-wave resonances in the acoustic scattering amplitude of a normally incident plane wave. A large number of cases of repulsion are found in the phase-velocity dispersion curves of the various types of circumferential waves due to the shell–fluid coupling.
Messa di voce: An investigation of the symmetry of crescendo and decrescendo in a singing exercise
Authors: Titze Ingo R. , Long Russel , Shirley George I. , Stathopoulos Elaine , Ramig Lorraine O. , Carroll Linda M. , Riley William D.
Published: July 2002

A classical vocal exercise called “messa di voce” (Italian for “placing the voice”) was used to study the symmetry of intensity increase and decrease in six trained singers. Ideally, the exercise is performed as a symmetric triangle, a linear increase in loudness, followed by a linear decrease. Given that some physiologic variables, like lung volume, undergo unidirectional change rather than a symmetric reversal, there is reason to believe that symmetries may not exist. It was found that highly trained singers who use large SPL ranges tend to abbreviate the decrescendo phase in comparison with the crescendo phase. In a few other cases, a plateau in SPL is reached, but an increase in loudness may still be perceived on the basis of a stronger vibrato or changes in timbre.
Contributions of temporal encodings of voicing, voicelessness, fundamental frequency, and amplitude variation to audio-visual and auditory speech perception
Authors: Faulkner Andrew , Rosen Stuart
Published: July 2002

Auditory and audio-visual speech perception was investigated using auditory signals of invariant spectral envelope that temporally encoded the presence of voiced and voiceless excitation, variations in amplitude envelope and F0. In experiment 1, the contribution of the timing of voicing was compared in consonant identification to the additional effects of variations in F0 and the amplitude of voiced speech. In audio-visual conditions only, amplitude variation slightly increased accuracy globally and for manner features. F0 variation slightly increased overall accuracy and manner perception in auditory and audio-visual conditions. Experiment 2 examined consonant information derived from the presence and amplitude variation of voiceless speech in addition to that from voicing, F0, and voiced speech amplitude. Binary indication of voiceless excitation improved accuracy overall and for voicing and manner. The amplitude variation of voiceless speech produced only a small increment in place of articulation scores. A final experiment examined audio-visual sentence perception using encodings of voiceless excitation and amplitude variation added to a signal representing voicing and F0. There was a contribution of amplitude variation to sentence perception, but not of voiceless excitation. The timing of voiced and voiceless excitation appears to be the major temporal cues to consonant identity.
A pulsed phase-sensitive technique for acoustical measurements
Authors: Kozhevnikov Vladimir F. , Arnold Dmitrii I. , Briggs Matthew E. , Naurzakov Salim P. , Viner John M. , Taylor P. Craig
Published: July 2002

The pulsed phase-sensitive (PPS) technique for measurements of sound velocity and attenuation in fluids and solids is reviewed. With this technique, which uses a cycle-overlap principle, a time delay is measured between any two acoustical pulses transmitted through a sample or reflected from its boundaries. A current realization of the technique allows one to resolve the time-delay variation down to 0.1 ns. Thus at relative measurements with the PPS technique, precise sound velocity data can be obtained for samples of small thickness (about 1 mm). The technique is versatile and can also be used for accurate absolute measurements. The technique is most advantageous for studies of samples with high attenuation, in particular near phase transitions and at high temperatures. The technique also allows one to measure sound attenuation with moderate accuracy. An application of the technique that employs narrow-band radio frequency (rf) bursts for relative measurements of the phase sound velocity is considered in detail. The technique is applied to studies of liquid alkali metals and mercury at temperatures up to 2100 K and pressures up to 200 MPa. As a verification of the capabilities of the technique, new results are presented on sound attenuation in mercury in the metal–nonmetal transition region. A table for sound velocity in mercury at temperatures from 550 to 1900 K and pressures up to 190 MPa is presented in the Appendix.
The dynamic range of inner hair cell and organ of Corti responses
Authors: Cheatham M. A. , Dallos P.
Published: July 2002

Inner hair cell (IHC) and organ of Corti (OC) responses are measured from the apical three turns of the guinea pig cochlea, allowing access to regions with best, or most sensitive, frequencies at approximately 250, 1000, and 4000 Hz. In addition to measuring both ac and dc receptor potentials, the average value of the half-wave rectified response (AVEHR) is computed to better reflect the signal that induces transmitter release. This measure facilitates comparisons with single-unit responses in the auditory nerve. Although IHC ac responses exhibit compressive growth, response magnitudes at high levels depend on stimulus frequency. For example, IHCs with moderate and high best frequencies (BF) exhibit more linear responses below the BF of the cell, where higher sound-pressure levels are required to approach saturation. Because a similar frequency dependence is observed in extracellular OC responses, this phenomenon may originate in cochlear mechanics. At the most apical recording location, however, the pattern documented at the base of the cochlea is not seen in IHCs with low BFs around 250 Hz. In fact, more linear behavior is measured above the BF of the cell. These frequency-dependent features require modification of cochlear models that do not provide for longitudinal variations and generally depend on a single stage of saturation located at the synapse. Finally, behavior of dc and AVEHR responses suggests that a single IHC is capable of coding intensity over a large dynamic range [Patuzzi and Sellick, J. Acoust. Soc. Am. 74, 1734–1741 ; Smith et al., in Hearing—Physiological Bases and Psychophysics (Springer, Berlin, ; Smith, in Auditory Function (Wiley, New York, ] and that information compiled over wide areas along the cochlear partition is not essential for loudness perception, consistent with psychophysical results [Viemeister, Hearing Res. 34, 267–274 ].
Design and construction of a solar thermal powered thermo- acoustically driven thermoacoustic refrigerator
Authors: Adeff Jay A. , Hofler Thomas J.
Published: July 2002

A compact, small temperature span, thermoacoustically driven thermoacoustic refrigerator powered by solar thermal energy has been successfully built and tested. An 18-in-diam Fresnel lens was used to focus sunlight at 475°C onto the hot end of a 1-in-diam reticulated vitreous carbon prime mover stack, thereby eliminating the need for a hot heat exchanger. The high intensity sound waves produced by the prime mover were used to power a thermoacoustic refrigerator to produce 4 W of cooling power at a cold temperature of 5°C and a temperature span of 18°C.
Variation between Antiferromagnetism and Ferrimagnetism in NiPS3 by Electron Doping
Authors: Mi Mengjuan , Zheng Xingwen , Wang Shilei , Zhou Yang , Yu Lixuan , Xiao Han , Song Houning , Shen Bing , Li Fangsen , Bai Lihui , Chen Yanxue , Wang Shanpeng , Liu Xiaohui , Wang Yilin
Published: May 2022

To electrically control magnetic properties of material is promising toward spintronic applications, where the investigation of carrier doping effects on antiferromagnetic (AFM) materials remains challenging due to their zero net magnetization. In this work, the authors find electron doping dependent variation of magnetic orders of a 2D AFM insulator NiPS3, where doping concentration is tuned by intercalating various organic cations into the van der Waals gaps of NiPS3 without introduction of defects and impurity phases. The doped NiPS3 shows an AFM‐ferrimagnetic (FIM) transition at a doping level of 0.2–0.5 electrons/cell and a FIM‐AFM transition at a doping level of ≥0.6 electrons/cell. The authors propose that the found phenomenon is due to competition between Stoner exchange dominated inter‐chain ferromagnetic order and super‐exchange dominated AFM order at different doping level. The studies provide a viable way to exploit correlation between electronic structures and magnetic properties of 2D magnetic materials for realization of magnetoelectric effect.
Donor Functionalization Tuning the N‐Type Performance of Donor–Acceptor Copolymers for Aqueous‐Based Electrochemical Devices
Authors: Cong Shengyu , Chen Junxin , Wang Lewen , Lan Liuyuan , Wang Yazhou , Dai Haojie , Liao Hailiang , Zhou Yecheng , Yu Yaping , Duan Jiayao , Li Zhengke , McCulloch Iain , Yue Wan
Published: May 2022

In this work, three n‐type donor–acceptor copolymers consisting of glycolated naphthalene tetracarboxylicdiimide (gNDI) coupled with variable donating companion moieties are reported. Using 2,2′‐bis(3,4‐ethylenedioxy)bithiophene, 2,​2′‐​bithiophene, 3,3′‐difluoro‐2,2′‐bithiophene (FBT), the donating strength of the donor units is systematically functionalized. These copolymers are used as a platform for aqueous‐based electrochemical devices, including energy‐storage devices, electrochromic devices (ECDs), and organic electrochemical transistors (OECTs). It is found that the electrochemical redox stability and electron mobility of copolymers are significantly improved via weakening the electron‐donating strength of donor units. gNDI coupling with FBT (gNDI‐FBT) exhibits a charge‐storage capacity exceeding 190 Fg−1, which is the highest value reported to date for NDI‐based polymer electrodes in aqueous media. For ECDs, gNDI‐FBT remains 100% of initial electrochromism contrast (∆%T = 20%) up to 1200 s. In addition, gNDI‐FBT outperforms its two analogs in OECTs, including lower threshold voltage (0.19 V), faster response time (45.5 ms), and higher volumetric capacitance (197 F cm−3). Moreover, gNDI‐FBT with fluorine atoms leads to the bipolarons delocalization along the polymer backbone and favorable molecular packing for ion–electron transport. Through such weak donor functionalization strategy, this work provides ways for n‐type copolymers tuning to access desirable performance metrics in optical, electrochemical, and bioelectronic applications.
Quasiplanar Heterojunction All‐Polymer Solar Cells: A Dual Approach to Stability
Authors: Cao Congcong , Wang Hengtao , Qiu Dongsheng , Zhao Tingxing , Zhu Yulin , Lai Xue , Pu Mingrui , Li Yan , Li Heng , Chen Hui , He Feng
Published: May 2022

In addition to efficiency, stability is another key factor in developing organic solar cells. The quasiplanar heterojunction (Q‐PHJ) structure, combining two pure layers as major and tiny nanoscale bulk heterojunction (BHJ) at interface, demonstrates superior device stability compared with BHJ devices. In this contribution, the polymer donor, PBQx‐H‐TF, and configurationally defined polymeric acceptor, PBTIC‐γ‐TSe are synthesized and used to fabricate bilayer devices by orthogonal solvents, the corresponding Q‐PHJ all‐polymer solar cells (all‐PSCs) deliver reliable stability with high efficiency. An encouraging PCE of 15.77% is achieved, which is the highest one among Q‐PHJ all‐PSCs with real‐bilayer structure. There is a major improvement over the 13.91% PCE in the BHJ device, and the carrier transport performance is improved substantially following the reduction of recombination in the Q‐PHJ all‐PSCs. Benefiting from the bilayer morphology, the stability of Q‐PHJ all‐PSCs has been greatly enhanced over that of the BHJ devices. The charge recombination process is also more serious in the aging BHJ compared with the aging Q‐PHJ all‐PSCs. This work inspires the application of Q‐PHJ in the preparation of high‐efficient all‐PSCs, but also provides guidance on the improvement of device stability from a dual approach of material and device engineering aspects.
Photoinduced Contraction Fibers and Photoswitchable Adhesives Generated by Stretchable Supramolecular Gel
Authors: Li Jinjie , Wang He , Liu Binxiu , Chen Jianzhuang , Gu Jinlou , Lin Shaoliang
Published: May 2022

Dynamically crosslinked supramolecular networks have emerged in the last decades as extremely stretchable and self‐healing materials thanks to the energy dissipation in weak and reversible interactions. Stretchable materials with tunable properties represent an effort to develop a charming class of smart devices. Once stretched, however, these materials’ properties are usually fixed due to strain‐induced crystallization (SIC), hindering their practical applications. Here, photoinduced contraction smart fibers and photoswitchable adhesives are generated from a dynamic supramolecular gel network, the SIC in which can be disrupted by UV irradiation to release the prestored strain energy. The dynamic sliding of azo‐bridged bipedal host molecules along the polymer chains renders the extreme stretchability of supramolecular gel under stretching forces. The oriented crystalline microdomains or crystallites through SIC upon stretching serve as physical crosslinks to store the contractile energy of fibers and improve the adhesion force of adhesives, and then are disoriented induced by trans‐to‐cis isomerization of azobenzene mesogens to release the prestored strain energy, resulting in such contraction of fibers and reduction of adhesion strength of adhesives. This work provides inspiration for exploring the structure–property relationship of supramolecular networks and transforming their clear potential to fabricate more remarkable synthetic smart materials.
Wirelessly Powered 3D Printed Hierarchical Biohybrid Robots with Multiscale Mechanical Properties
Authors: Tetsuka Hiroyuki , Pirrami Lorenzo , Wang Ting , Demarchi Danilo , Shin Su Ryon
Published: May 2022

The integration of flexible and stretchable electronics into biohybrid soft robotics can spur the development of new approaches for fabricating biohybrid soft machines, thus enabling a wide variety of innovative applications. Inspired by flexible and stretchable wireless‐based bioelectronic devices, untethered biohybrid soft robots are developed that can execute swimming motions, which are remotely controllable by the wireless transmission of electrical power into a cell simulator. To this end, wirelessly‐powered, stretchable, and lightweight cell stimulators are designed to be integrated into muscle bodies without impeding the robots’ underwater swimming abilities. The cell stimulators function by generating controlled monophasic pulses of up to ≈9 V in biological environments. By differentiating induced pluripotent stem cell‐derived cardiomyocytes directly on the cell stimulators using an accordion‐inspired, three‐dimensional (3D) printing construct, the native myofiber architecture are replicated with comparable robustness and enhanced contractibility. Wirelessly modulated electrical frequencies enables the control of speed and direction of the biohybrid soft robots. A maximum locomotion speed of ≈580 µm s−1 is achieved in robots possessing a large body size by adjusting the pacing frequency. This innovative approach will provide a platform for building untethered and biohybrid systems for various biomedical applications.
A Flexible, Transparent, Ultralow Detection Limit Capacitive Pressure Sensor
Authors: Zammali Marouen , Liu Sijun , Yu Wei
Published: May 2022

The capacitive pressure sensor (CPS) with low detection limit and high sensitivity is crucial for the future development of electronic skins. Although introducing surface microstructures on dielectric layer may improve the sensitivity of CPS in some extent, it leads to a limited pressure‐response range due to the poor structural compressibility. Moreover, such microstructures deteriorate the transparency and flexibility of the final sensor and require costly microfabrication methods. Herein, a low‐cost high performance pressure sensor is developed by integrating the high permittivity and soft dielectric gel with the mechanically comparable ionic conductor. The device shows an unprecedented detection limit of 0.2 Pa, a high sensitivity of 4.2 kPa−1 in the low‐pressure regime of <1.2 kPa, and a fast response time of 13 ms. This ultralow detection limit allows for the efficient and accurate detection of weak pressure signals from acoustic waves to pulse and air‐flow, exhibiting promising application potentials in voice recognition, screening of cardiovascular diseases, and diagnosis of gas leakage. Furthermore, the combination of ionic conductor and dielectric gel also endows the capacitive pressure sensor with remarkable transparency, mechanical stability, and durability even under extreme environments. This study proposes a novel perspective for development of flexible and transparent electronic skins.
Liquid Crystalline Thermosetting Composites‐Based Triboelectric Nanogenerators with Intrinsic Flame Retardancy
Authors: Qadeer Mohsen , Guan Qingbao , Guo Qingzhao , Rahman Abdul , Nawaz Muhammad Zubair , Zhou Jianfeng , Zhu Shu
Published: May 2022

Triboelectric nanogenerators (TENGs) have drawn essential interest as highly sensitive sensors that can function efficiently in harsh conditions, which can be life‐saving but challenging to accomplish. Herein, this work explores carbon fiber (CF)‐reinforced liquid crystalline thermosetting (LCT) triboelectric composites as flame retardant triboelectric nanogenerators (FR‐TENGs). FR‐TENGs with controlled structural and chemical properties exhibit not only outstanding flame resistance but also excellent triboelectric performance and can be utilized in the oil drilling industry and space applications under extreme temperatures. This FR‐TENG is incombustible even after 60 s of trying, where most traditional triboelectric materials were burnt completely under similar conditions. The self‐powered FR‐TENG exhibits high thermal resistance and strong mechanical strength and generates Voc (125.7 V), Qsc (14 nC), and Isc (0.8 µA) as electrical performances. In addition, the developed carbon fiber reinforced liquid crystalline thermosetting (LCT‐2@BCF) composite also poses a shape memory effect (SME), which can be employed for early fire alarm sensors. This work manifests the bright prospect of applying CF/LCT composites in fields that require light weight, high strength, high temperature resistance, and flame retardancy.
Development of Highly Sensitive and Stable Surface Acoustic Wave‐Based Hydrogen Sensor and Its Interface Electronics
Authors: Kim Sihyeok , Singh Gurpreet , Lee Keekeun
Published: May 2022

A surface acoustic wave (SAW)‐based hydrogen sensor and its corresponding interface electronics have been developed to measure the hydrogen concentration in air at room temperature. Two SAW delay lines with center frequencies of 284 and 284.3 MHz are employed for the sensor system to eliminate any environmental disturbances emerging from temperature and humidity variations on a sensor output. A beehive‐configured and Cu‐doped SnO2 nanostructure is used as a hydrogen‐sensitive material to have a high surface to volume ratio, high sensitivity, and selectivity for the target hydrogen. The smallest frequency difference detectable in our sensor system including oscillator, mixer, low pass filter, comparator, and field programmable gate array (FPGA) was ≈1 Hz, which is a significant output value that can sufficiently detect hydrogen concentrations below 1 ppm. Compared with pure SnO2, 3D Cu (3%)‐doped SnO2 nanostructure based‐SAW sensor exhibited the highest response to hydrogen gas. The elevated response of the 3D Cu‐doped SnO2 based SAW sensor to hydrogen gas is mainly attributed to the acoustoelectric interaction. Photoluminescence and X‐ray photoelectron spectroscopy analysis divulged that Cu‐doping in SnO2 produces a large number of surface oxygen vacancies, which enhances the hydrogen adsorption on the SnO2 surface, resulting in a significant improvement in the response to hydrogen gas. The sensor characteristics at the system level showed excellent selectivity, repeatability, and long‐term stability to hydrogen gas. The sensing mechanisms (mass loading and acoustoelectric interaction) in the SAW sensor due to hydrogen adsorption have been experimentally investigated and the obtained results are discussed in detail.
Intense Electrical Pulsing of Perovskite Light Emitting Diodes under Cryogenic Conditions
Authors: Elkhouly Karim , Goldberg Iakov , Annavarapu Nirav , Gehlhaar Robert , Ke Tung‐Huei , Genoe Jan , Hofkens Johan , Heremans Paul , Qiu Weiming
Published: May 2022

As the threshold for stimulated emission is significantly reduced at cryogenic temperatures, cooling of perovskite light emitting diodes (PeLEDs) is considered an essential strategy for reaching injection lasing in perovskite diodes. In this work, we demonstrate the intense electrical pulsing of a PeLED stack up to a few kA cm−2 at cryogenic conditions. A high external quantum efficiency (EQE) of 2.9% at 1 kA cm−2 and a radiance >1.95 × 105 W Sr−1 m−2 are achieved when exciting the device with 250 ns electrical pulses at 77 K, showing three times enhancement in comparison with room temperature operation. Furthermore, we provide a comprehensive understanding on how the ion distribution can affect the PeLED characteristics and show that ion motions can be manipulated at cryogenic conditions. This opens new routes for novel material and device designs for further improving PeLED performance.
DBU/AgOTf Relay‐Catalysis Enabled One‐Pot Synthesis of 1,3‐Dihydroisobenzofurans and Its Conversion to Indanones
Authors: Wang Jiazhuang , Huang Hongtai , Gao Haotian , Qin Guiping , Xiao Tiebo , Jiang Yubo
Published: May 2022

A DBU/AgOTf relay‐catalyzed one‐pot reaction of 2‐alkynylbenzaldehydes and α‐diazo esters for the efficient construction of 1,3‐dihydroisobenzofuran derivatives has been documented. This protocol can tolerate a wide range of substrates and its scalability is demonstrated by the gram‐scale reaction. Moreover, the obtained 1,3‐dihydroisobenzofurans can be converted to indanone derivatives by a AgOTf‐catalyzed ring recombination process. Both of the resulting products, 1,3‐dihydroisobenzofurans and indanones, are important structural units of a variety of pharmaceuticals and natural products, and their structures are clearly confirmed by single crystal X‐ray diffraction analysis.

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Response to Christopher P. Muzzillo's Comments on “Introduction of a Novel Figure of Merit for the Assessment of Transparent Conductive Electrodes in Photovoltaics: Exact and Approximate Form”
Authors: Anand Aman , Islam Md Moidul , Meitzner Rico , Schubert Ulrich S. , Hoppe Harald
Published: May 2022

Similarities and differences between figure of merits (FOMs) for the assessment of transparent conductive electrodes (TCEs) are discussed. This article is a response to C. P. Muzzillo's comment on the introduction of the novel FOM (the so‐called exact FOM or Anand's FOM) and it deals with questions about how implicit and how exact the different approaches really are and whether specific application cases can be covered or not. While the exact FOM has been introduced to provide an upper limit of photovoltaic power conversion efficiency for the whole range of possible transmittance and sheet resistance values of transparent conductive oxides, Muzzillo's comment points out specific application cases, that have to be treated with more individual modeling. In this work, the authors adopt these application cases into the exact FOM to demonstrate its applicability. Furthermore, the FOM approximation given by Muzzillo is used and slightly refined, yielding an even better agreement with the exact FOM. In the end, it is concluded that both approaches are justified: Muzzillo's FOM for very practical applications and Anand's (exact) FOM for fundamental assessment. In this work, both approaches have been harmonized to yield an ultimate tool for the future development of TCEs for photovoltaics.
Pyridinylidenaminophosphines as Versatile Organocatalysts for CO2 Transformations into Value‐Added Chemicals
Authors: Lu Shang‐Yuan , Chen Wei , Wen Lang‐Qi , Zhou Hui
Published: May 2022

The carboxylative cyclization of propargylic alcohols with CO2 was developed employing pyridinylidenaminophosphines (PYA‐Ps) as organocatalyts for the first time. Moderate to good yields of α‐methylene cyclic carbonates were obtained with excellent chemo‐ and stereo‐selectivity. Density functional theory (DFT) calculations reveal that the catalytic reaction tends to proceed via the PYA‐Ps‐mediated basic ionic pair mechanism, and the intramolecular cyclization should be the rate determining step. Furthermore, the catalytic diversity of PYA‐Ps was investigated for the chemical transformations of CO2 to functionalized cyclic carbonates and N‐formylated amines.
Continuous reactor network design for multi‐product rigid polyols under uncertainty
Authors: Wen Yunhan , Biegler Lorenz T. , Ochoa Maria P. , Weston John , Nikbin Nima , Ferrio Jeff
Published: May 2022

Differential‐algebraic optimization models for rigid polyol production from our previous work are able to generate optimal reactor configurations along with the optimal operation recipe. However, their performance could degenerate when uncertainty comes into play. In this study, we apply a multi‐scenario (MS) strategy to analyze the impact of kinetic uncertainty on reactor network design. Our approach first identifies scenarios that are worst‐case violations of inequality constraints. Then, we solve the MS problem with current number of scenarios and obtain the optimal common (or first‐stage) decision profiles (q). Next, we apply an iterative scenario sampling and updating strategy, where the uncertainty range is sampled for fixed q to discover constraint violations that determine the need for additional scenarios. This process continues until no further violations are detected. We adopt the MS method to three continuous reactor networks that were optimized in our previous work: CSTR in series, single differential sidestream reactor (DSR) and CSTR followed by a DSR. Among these, the DSR reactor is found to be the most economical and robust with respect to uncertainties.
Electrostatically Directed Long‐Range Self‐Assembly of Nucleotides with Cationic Nanoparticles To Form Multifunctional Bioplasmonic Networks
Authors: Roy Sumit , Adury Venkata Sai Sreyas , Rao Anish , Roy Soumendu , Mukherjee Arnab , Pillai Pramod P.
Published: May 2022

Precise control over interparticle interactions is essential to retain the functions of individual components in a self‐assembled superstructure. Here, we report the design of a multifunctional bioplasmonic network via an electrostatically directed self‐assembly process involving adenosine 5′‐triphosphate (ATP). The present study unveils the ability of ATP to undergo a long‐range self‐assembly in the presence of cations and gold nanoparticles (AuNP). Modelling and NMR studies gave a qualitative insight into the major interactions driving the bioplasmonic network formation. ATP‐Ca2+coordination helps in regulating the electrostatic interaction, which is crucial in transforming an uncontrolled precipitation into a kinetically controlled aggregation process. Remarkably, ATP and AuNP retained their inherent properties in the multifunctional bioplasmonic network. The generality of electrostatically directed self‐assembly process was extended to different nucleotide–nanoparticle systems.
ω‐(5‐Phenyl‐2H‐tetrazol‐2‐yl)alkyl‐substituted hydrazides and related compounds as inhibitors of amine oxidase copper containing 3 (AOC3)
Authors: Galster Florian , Pöstges Timo , Hanekamp Walburga , Lehr Matthias
Published: May 2022

Amine oxidase copper containing 3 (AOC3), also known as plasma amine oxidase, semicarbazide‐sensitive amine oxidase, or vascular adhesion protein‐1, catalyzes the oxidative deamination of primary amines to aldehydes using copper and a quinone as cofactors. Because it is involved in the transmigration of inflammatory cells through blood vessels into tissues, AOC3 is thought to play an important role in inflammatory diseases. Therefore, inhibitors of this enzyme could lead to new therapeutics for the treatment of inflammation‐related diseases. Recently, 6‐(5‐phenyl‐2H‐tetrazol‐2‐yl)hexan‐1‐amine was found to be a tight‐binding substrate of AOC3. To obtain novel inhibitors of the enzyme, the amino group of this substrate was replaced with functional groups that occur in known AOC3 inhibitors, such as hydrazide or glycine amide moieties. In addition, derivatives of the compounds obtained in this way were prepared. The obtained hydrazide 5, which proved to be the most effective, was subjected to further structural modifications. Selected hydrazides were evaluated for selectivity toward some other amine oxidases.
Immunogenicity and Safety of Standard and Third‐Dose SARS–CoV‐2 Vaccination in Patients Receiving Immunosuppressive Therapy
Authors: Syversen Silje W. , Jyssum Ingrid , Tveter Anne T. , Tran Trung T. , Sexton Joseph , Provan Sella A. , Mjaaland Siri , Warren David J. , Kvien Tore K. , Grødeland Gunnveig , Nissen‐Meyer Lise S. H. , Ricanek Petr , Chopra Adity , Andersson Ane M. , Kro Grete B. , Jahnsen Jørgen , Munthe Ludvig A. , Haavardsholm Espen A. , Vaage John T. , Lund‐Johansen Fridtjof , Jørgensen Kristin K. , Goll Guro L.
Published: May 2022

Objective

Immunogenicity and safety following receipt of the standard SARS–CoV‐2 vaccination regimen in patients with immune‐mediated inflammatory diseases (IMIDs) are poorly characterized, and data after receipt of the third vaccine dose are lacking. The aim of the study was to evaluate serologic responses and adverse events following the standard 2‐dose regimen and a third dose of SARS–CoV‐2 vaccine in IMID patients receiving immunosuppressive therapy.

Methods

Adult patients receiving immunosuppressive therapy for rheumatoid arthritis, spondyloarthritis, psoriatic arthritis, Crohn's disease, or ulcerative colitis, as well as healthy adult controls, who received the standard 2‐dose SARS–CoV‐2 vaccination regimen were included in this prospective observational study. Analyses of antibodies to the receptor‐binding domain (RBD) of the SARS–CoV‐2 spike protein were performed prior to and 2–4 weeks after vaccination. Patients with a weak serologic response, defined as an IgG antibody titer of ≤100 arbitrary units per milliliter (AU/ml) against the receptor‐binding domain of the full‐length SARS–Cov‐2 spike protein, were allotted a third vaccine dose.

Results

A total of 1,505 patients (91%) and 1,096 healthy controls (98%) had a serologic response to the standard regimen (P < 0.001). Anti‐RBD antibody levels were lower in patients (median 619 AU/ml interquartile range [IQR] 192–4,191) than in controls (median 3,355 AU/ml [IQR 896–7,849]) (P < 0.001). The proportion of responders was lowest among patients receiving tumor necrosis factor inhibitor combination therapy, JAK inhibitors, or abatacept. Younger age and receipt of messenger RNA–1273 vaccine were predictors of serologic response. Of 153 patients who had a weak response to the standard regimen and received a third dose, 129 (84%) became responders. The vaccine safety profile among patients and controls was comparable.

Conclusion

IMID patients had an attenuated response to the standard vaccination regimen as compared to healthy controls. A third vaccine dose was safe and resulted in serologic response in most patients. These data facilitate identification of patient groups at risk of an attenuated vaccine response, and they support administering a third vaccine dose to IMID patients with a weak serologic response to the standard regimen.
Observer‐based controller of uncertain Switching Positive Linear Systems: A unilaterally tracking scheme
Authors: Nojoumian Mohammad Ali , Zakerzadeh Mohammad Reza , Ayati Moosa
Published: May 2022

This paper deals with designing a unilateral tracking controller for the Switching Positive Linear Systems (SPLSs). Positive systems are widespread, and most biological, economic systems, and so on, with nonnegative variables, belong to this class of systems. System states are assumed partially unmeasurable; thus, a reduced‐order positive switching observer is utilized to improve the closed‐loop system response. Also, interval uncertainty is considered to provide a more practical result. In addition, a unilateral tracking controller is developed in this study. The unilateral tracking controller keeps the system and observer states in the same direction as the reference system and system output. Also, the unilateral tracking method avoids overshoot. System stability is presented in synchronous and asynchronous switching conditions. In asynchronous switching mode, controller switches have a time lag behind the system's switching. The switching time lag in asynchronous mode is assumed unknown with a known upper bound for each subsystem. The closed‐loop system's stability is guaranteed by utilizing multiple Lyapunov functions, and the Mode Dependent Average Dwell Time (MDADT) strategy. The designed unilateral tracking controller is developed to track a reference system. Also, sufficient conditions are provided to guarantee the L1‐gain performance of the closed‐loop system. Finally, an illustrative example is provided to demonstrate the proposed scheme's effectiveness compared with the foremost existing solutions.
Optimizing transcardial perfusion of small molecules and biologics for brain penetration and biodistribution studies in rodents
Authors: Noh Keumhan , Liu Xingrong , Wei Cong
Published: May 2022

Efficiently removing blood from the brain vasculature is critical to evaluate accurately the brain penetration and biodistribution of drug candidates, especially for biologics as their blood concentrations are substantially higher than the brain concentrations. Transcardial perfusion has been used widely to remove residual blood in the brain; however, the perfusion conditions (such as the perfusion rate and time) reported in the literature are quite varied, and the performance of these methods on blood removal has not been investigated thoroughly. In this study, the effectiveness of the perfusion conditions was assessed by measuring brain hemoglobin levels. Sodium nitrite (NaNO2) as an additive in the perfusate was evaluated at different concentrations. Blood removal was significantly improved with 2% NaNO2 over a 20 min perfusion in mouse without disrupting the integrity of the blood‐brain barrier (BBB). In mice, the optimized perfusion method significantly lowered the measured brain‐to‐plasma ratio (Kp,brain) for monoclonal antibodies due to the removal of blood contamination and small molecules with a moderate‐to‐high BBB permeability and with a high brain‐unbound‐fraction (fu,brain) presumably due to flux out of the brain during perfusion. Perfusion with or without NaNO2 clearly removed the residual blood in rat brain but with no difference observed in Kp,brain between the perfusion groups with or without 2% NaNO2. In conclusion, a perfusion method was successfully developed to evaluate the brain penetration of small molecules and biologics in rodents for the first time. The transcardial perfusion with 2% NaNO2 effectively removed the residual blood in the brain and significantly improved the assessment of brain penetration of biologics. For small molecules, however, transcardial perfusion may not be performed, as small molecule compounds could be washed away from the brain by the perfusion procedure.
Does the legacy of state planning put pressure on ecological efficiency? Evidence from China
Authors: Hao Yu , Huang Jingwen , Guo Yunxia , Wu Haitao , Ren Siyu
Published: May 2022

Building a green and healthy economic system and achieving high‐quality economic growth have long been the development goals pursued by the Chinese government. Under the local government competition system, coordinating the relationship between economic growth and ecological sustainability is a decisive factor for China's high‐quality development. As a former state planned economy, China inherited a legacy of setting economic growth targets at various levels of government. This paper analyzes the relationship between economic growth targets and ecological efficiency by using panel data models and spatial econometric techniques. Moreover, the mediating effect model and dynamic threshold effect model are used to study their influence mechanism and the possible nonlinear relationship. The results indicate that there is an inverted U‐shaped relationship between economic growth targets and ecological efficiency. Optimizing industrial structure and R&D investment can improve regional ecological efficiency. The economic growth targets in neighboring regions have a “U”‐shaped relationship with local ecological efficiency. The mechanism test results suggest that economic growth targets affect ecological efficiency by influencing financial development, foreign direct investment, infrastructure investment, environmental regulation, and technological innovation. The impact of economic growth targets on ecological efficiency shows a significant threshold effect when economic growth targets, industrial structure, R&D levels, financial development, foreign direct investment, infrastructure investment, and environmental regulation are at different threshold values. Therefore, to promote regional healthy competition and ecological efficiency, the government should formulate scientific and reasonable economic growth goals and improve the official evaluation system.
A preliminary investigation of digital media supplements for head and neck anatomy: Does production format matter?
Authors: Willett Gilbert M. , Forbes Anna , Spagna James , O'Kane Barbara , Weston Michael , Jergenson Margaret , Norton Neil S.
Published: May 2022

From cassettes to digital, use of video in education has evolved. Supplemental digital media is a common educational adjunct within gross anatomy courses. As these aids have advanced technologically, so has production cost. Traditional lecture (T‐lect) productions tend to be more efficient. Traditional gross anatomy laboratory (T‐lab) productions requiring cadaver dissection and high‐definition video are comparatively less efficient. This preliminary study pragmatically assessed T‐lect and T‐lab supplemental learning tools in a head and neck anatomy course for first‐year dental students. Two videos of similar length were developed for different anatomical regions. Learning objectives were similar while format differed. A carotid triangle supplement was created using a T‐lab production format and an infratemporal fossa aid was created using a T‐lect format. Both incorporated recommended elements for facilitating learning. Development time and costs were documented. Student exam performance on topic specific questions was collected along with survey data. Group mean exam score comparisons between students who viewed (n = 74 T‐lect, n = 70 T‐lab) versus did not view (n = 27 T‐lect, n = 30 T‐lab) each aid revealed higher scores for the “viewed” group. The T‐lab production cost ($15,190 versus $10,003) and time (19 hr. versus 18 hr) were greater than T‐lect. Descriptive survey data did not reveal a format preference. Students valued previews/summaries and structure highlighting/labeling within the supplements. Students appreciated the supplemental learning aids and mean exam scores were higher for users. Since production format did not noticeably alter exam performance and satisfaction was similar, production efficiency should take precedence.
USPSTF says not enough evidence to support screening for eating disorders
Authors: Knopf Alison
Published: May 2022

The evidence is insufficient to support either the benefits or harms of screening for eating disorders in asymptomatic adults and adolescents, the United States Preventive Services Task Force (USPSTF) has determined. In a March 15 recommendation, the quasi‐governmental body made the decision which, basically, precludes insurability of the service and also calls question into its validity at this point.
Case report: Bilateral simple Syndactyly in a toddler with maternal exposure to cabergoline
Authors: Afshar Shima , Abbasinazari Mohammad , Darvishi Behnam , Ziaie Shadi , Esmaily Hadi
Published: May 2022

Cabergoline is routinely prescribed in the management of prolactin excreting adenomas and is associated with low risk of congenital malformations and teratogenicity. Here, we reported the case of a bilateral simple syndactyly in a toddler with maternal exposure to cabergoline during the pregnancy. This association has not been previously described before.
High‐pressure synthesis, crystal structure, and properties of a novel quadruple perovskite CeMn3Rh4O12
Authors: Kato Yuta , Nakajima Hiroshi , Kawaguchi Shogo , Mori Shigeo , Yamada Ikuya
Published: May 2022

A novel transition metal oxide CeMn3Rh4O12 has been synthesized using high‐pressure and high‐temperature conditions of 12 GPa and 1573 K. CeMn3Rh4O12 crystallizes in the AA'3B4O12‐type quadruple perovskite structure with A‐site ordering in a cubic space group of Im in the high‐temperature phase at above 310 K, whereas CeMn3Rh4O12 undergoes a structural phase transition with symmetry lowering down to probable triclinic symmetry on cooling below this temperature. X‐ray absorption spectroscopy reveals that all the constituent ions are trivalent at room temperature, suggesting the valence state of Ce3+Mn3+3Rh3+4O12. Magnetization study demonstrates an antiferromagnetic transition attributed to A'‐site Mn3+ ions at TN = 35 K, whereas a Curie–Weiss analysis finds an additional paramagnetic component attributed to the Ce3+ 4f1 ions. We discuss the differences in structural and magnetic properties between CeMn3Rh4O12 and LaMn3Rh4O12, eventually proposing a possible stereochemical effect of Ce3+ on crystal structure in the quadruple perovskite.
Homolytic X‐H Bond Cleavage at a Gold(III) Hydroxide: Insights into One‐Electron Events at Gold
Authors: Engbers Silène , Leach Isaac F. , Havenith Remco W. A. , Klein Johannes E. M. N.
Published: May 2022

C(sp3)‐H and O−H bond breaking steps in the oxidation of 1,4‐cyclohexadiene and phenol by a Au(III)‐OH complex were studied computationally. The analysis reveals that for both types of bonds the initial X−H cleavage step proceeds via concerted proton coupled electron transfer (cPCET), reflecting electron transfer from the substrate directly to the Au(III) centre and proton transfer to the Au‐bound oxygen. This mechanistic picture is distinct from the analogous formal Cu(III)‐OH complexes studied by the Tolman group (J. Am. Chem. Soc. 2019, 141, 17236–17244), which proceed via hydrogen atom transfer (HAT) for C−H bonds and cPCET for O−H bonds. Hence, care should be taken when transferring concepts between Cu−OH and Au−OH species. Furthermore, the ability of Au−OH complexes to perform cPCET suggests further possibilities for one‐electron chemistry at the Au centre, for which only limited examples exist.
Activated Internal Alkyne‐Based Polymerization†
Authors: Li Baixue , Wang Jia , He Benzhao , Qin Anjun , Tang Ben Zhong
Published: May 2022

Comprehensive Summary

As an emerging and efficient polymerization methodology, activated internal alkyne‐based polymerization has been considered as a powerful tool for the construction of polymers with diverse architectures and versatile functions. This review focuses on the recent progresses in the polymerization using mono‐activated, di‐activated, in‐situ generated, ring‐strained ethynyl groups as substrates, coupling with post‐modification on premade polymers containing activated internal ethynyl moieties. Representative examples are used to illustrate the fundamental design strategy, the development of polymerization and post‐functionalization, along with the properties and potential applications of the prepared polymers. Moreover, the challenges and perspectives in terms of new‐type active alkynes, green polymerization methodology, tailored regio‐/stereoselectivity modulation, and potentially expanded application in this area are also discussed.