bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of fatigue behavior of high-density polyethylene based on dynamic viscoelastic and small angle light scattering measurements during the fatigue process (abstract)
Authors: Takahara Atsushi , Nishi Yoshio , Kaiya Norihiro , Kajiyama Tisato
Published: July 2002

The high-density polyethylene (HDPE) films have been prepared either through melt quenching or isothermal crystallization. The fatigue behavior of those HDPE films under constant strain amplitude has been investigated based on dynamic viscoelastic and small angle light scattering (SALS) measurements during the fatigue process. Nonlinear viscoelastic behavior under cyclic fatigue has been observed for both melt-quenched and isothermally crystallized HDPEs. Melt-quenched HDPE showed greater fatigue strength compared with isothermally crystallized HDPE. The SALS measurement under cyclic fatigue can reveal the deformation process of spherulitic structure during the fatigue process. Melt-quenched HDPE showed elongation of spherulitic structure under cyclic fatigue. On the other hand, isothermally crystallized HDPE did not show any elongation until the onset of fatigue fracture. The short fatigue lifetime and small deformation of spherulitic structure for isothermally crystallized HDPE can be ascribed to the sharp boundary between spherulitis.
Reproduction of the stress-strain curve for glassy polymers by a mechanical model bearing the concept of structural transition (abstract)
Authors: Yoshioka Shin-ya , Sugimoto Shoji , Nanzai Yukuo , Ueda Sachio
Published: July 2002

The rate analysis of steady plastic flow in glassy polymers has verified that the structure of the polymers is changed into a liquid-like structure during the yield process. This result motivated us to develop a mechanical model which predicts the stress-strain curve for glassy polymers. The model is composed of a dashpot and two elastic springs, where the viscosity of dashpot is a single parameter quantifying the structural transition and is approximated by a simple mathematical equation decreasing with increasing strain. Using this model, stress-strain relations were simulated for poly (methyl methacrylate) and poly (vinyl chloride) under uniaxial constant-rate tension and compression. The model reproduced successfully the experimental stress-strain curves over a wide range of temperature and strain rate for each case. This led to a conclusion that at a uniaxial constant deformation rate the structural change in the glasses is mainly governed by strain. Moreover, the optimum equation for the internal viscosity determined by the simulation indicated that the degree of structural change is closely related to both the yield strain and the strain range in the lower yield state.
Capillary flow properties of chemically cross-linked low-density polyethylene and isotactic polypropylene (abstract)
Authors: Fujiyama Mitsuyoshi
Published: July 2002

A low-density polyethylene (LDPE) sample and an isotactic polypropylene (PP) sample were chemically cross linked in molten state with dicumyl peroxide using liquid 1,2-polybutadiene (L-PB) as an auxiliary for PP. The effects of the degree of cross linking on their capillary flow properties have been studied. The apparent viscosity ηa of LDPE system at a constant shear rate rapidly increases until a gel content of 1.1 wt. %, which is due to the increase in molecular weight, and after that log ηa linearly increases with the gel fraction, which is due to an action of gel particles as filler. The dependence of ηa on the gel fraction is more notable at lower shear rate. The value of ηa at a constant shear rate of PP system with an L-PB content of 5 phr drops until a gel content of about 15 wt. %, and after that shows a maximum at a gel fraction of about 25 wt. %, and gradually decreases with the gel content. For the system of an L-PB content of 20 phr, ηa gradually increases with the gel fraction. The end-correction coefficient ν shows a maximum in a range of gel fractions from 15 to 40 wt. %. The flow activation energy at a constant shear rate, ΔHγ̇, of LDPE system decreases with the gel fraction and the flow activation energy at a constant shear stress, ΔHτ, shows a maximum at a gel fraction of about 70 wt. %.
Rheological study on solid structure in colloidal systems (abstract)
Authors: Matsumoto Takayoshi
Published: July 2002

Solid structure in colloidal systems can be roughly classified into two groups. One is the structure which is attributed to a random aggregation of the disperse particles, the other is the ordered structure due to a regular arrangement of the particles. For these types of structure, flow and large deformation are due to a slip in some plain at a constant stress which corresponds to the yield stress σy or the absolute value of the complex stress ‖σ*‖. The value of σy is nearly equal to ‖σ*‖ at long time scale region. That is, the Cox–Merz empirical rule (σ=‖G*‖ at γ̇=ω) cannot be applied for the deformation of the structure.
The Rayleigh approach to the rheology of compressible granular flow
Authors: Astarita Tommasso , Ocone Raffaella , Astarita Gianni
Published: July 2002

We develop a Rayleigh-type approach to the analysis of compressible granular flow. In this approach, a (possibly negative) influx of energy from the walls is taken into account. This is greatly advantageous in granular flow rheology, since such influx of energy arises spontaneously as soon as the balance between the energy influx (due to whatever mechanism keeps the unperturbed system in a thermalized state) and the dissipation rate is violated. We show that standing waves, although waves of a rather peculiar type, may well exist, and that such waves have thicknesses of several hundreds particle diameters. We also give an analysis of the stability of compressible granular flow, which exhibits some peculiar characteristics.
Calculation of the persistence length of solubilized starches from intrinsic viscosity measurements
Authors: Carriere C. J. , Bagley E. B.
Published: July 2002

The persistence lengths for two different commercial starches were estimated from intrinsic viscosity measurements. The intrinsic viscosities of the starches were measured at 25 °C using 90/10 dimethy sulfoxide (DMSO)/water (weight/weight) as the solvent. The calculations were conducted using the equations developed by Yamakawa and Yoshizaki [Macromolecules 13, 633–643 (1980)] and corrected for polydispersity using the Schultz–Flory distribution. Values for the persistence lengths were 8.1±0.6 and 6.6±0.5 nm for a high-amylose potato, and a high-amylose maize starch, respectively. The values for the persistence length obtained for the two starch samples reflect the stiffness of the amylose chains in DMSO, which is due to the helical conformation of amylose in the solvent.
Cancer Risk in Children of Mothers With Epilepsy and High-Dose Folic Acid Use During Pregnancy
Authors: Vegrim Håkon Magne , Dreier Julie Werenberg , Alvestad Silje , Gilhus Nils Erik , Gissler Mika , Igland Jannicke , Leinonen Maarit K. , Tomson Torbjörn , Sun Yuelian , Zoega Helga , Christensen Jakob , Bjørk Marte-Helene
Published: September 2022

Importance

Women with epilepsy are recommended high doses of folic acid before and during pregnancy owing to risk of congenital anomalies associated with antiseizure medications. Whether prenatal exposure to high-dose folic acid is associated with increases in the risk of childhood cancer is unknown.

Objective

To assess whether high-dose folic acid supplementation in mothers with epilepsy is associated with childhood cancer.

Design, Setting, and Participants

Observational cohort study conducted with nationwide registers in Denmark, Norway, and Sweden from 1997 to 2017. Analyses were performed during January 10, 2022, to January 31, 2022. Mother-child pairs were identified in medical birth registers and linked with information from patient, prescription, and cancer registers, as well as with sociodemographic information from statistical agencies, and were categorized by maternal diagnosis of epilepsy. The study population consisted of 3 379 171 children after exclusion of 126 711 children because of stillbirth or missing or erroneous values on important covariates.

Exposures

Maternal prescription fills for high-dose folic acid tablets (≥1 mg daily) between 90 days before pregnancy start and birth.

Main Outcomes and Measures

First onset of childhood cancer at younger than 20 years. Cox proportional hazards models were used to calculate adjusted hazard ratios with corresponding 95% CIs, adjusted for potential confounders. Cumulative incidence at aged 20 years was used as a measure of absolute risk.

Results

The median age at the end of follow-up in the study population of 3 379 171 children was 7.3 years (IQR, 3.5-10.9 years). Among the 27 784 children (51.4% male) born to mothers with epilepsy, 5934 (21.4%) were exposed to high-dose folic acid (mean dose, 4.3 mg), with 18 exposed cancer cases compared with 29 unexposed, producing an adjusted hazard ratio of 2.7 (95% CI, 1.2-6.3), absolute risk if exposed of 1.4% (95% CI, 0.5%-3.6%), and absolute risk if unexposed of 0.6% (95% CI, 0.3%-1.1%). In children of mothers without epilepsy, 46 646 (1.4%) were exposed to high-dose folic acid (mean dose, 2.9 mg), with 69 exposed and 4927 unexposed cancer cases and an adjusted hazard ratio of 1.1 (95% CI, 0.9-1.4; absolute risk, 0.4% [95% CI, 0.3%-0.5%]). There was no association between children born to mothers with epilepsy who were prenatally exposed to antiseizure medications, but not high-dose folic acid, and an increased risk of cancer (absolute risk, 0.6%; 95% CI, 0.2%-1.3%).

Conclusions and Relevance

Prenatal exposure to high-dose folic acid was associated with increased risk of cancer in children of mothers with epilepsy.
DNA Immobilization
Authors: Wittmann Christine
Published: September 2022

Immobilized DNA is used for various purposes, starting with the development of DNA chips and microarrays, and reaching to methods for gene delivery and DNA‐based vaccines. The broad application range for all of these DNA‐based systems can still be found in the medical area (e.g. diagnostics and therapeutics, combined ‘theranostics’). Furthermore, in particular, DNA sensors are described to ensure food safety. Hence, strategies for DNA immobilization are described in this article, with a strong focus on immobilization chemistry. Various immobilization techniques (e.g. via physical adsorption, covalent, affinity binding, and matrix entrapment/encapsulation) are already well established. The ‘top‐down’ techniques can be distinguished from the ‘bottom‐up’ techniques that started at the beginning of DNA chip development. Suitable synthetic and artificial DNA structures (e.g. DNA origami) are developed and become adapted to existing DNA platforms. Surfaces used for DNA immobilization comprise carbonaceous materials, silica and silicon surfaces, gold, and metal surfaces, in addition to (bio)polymers. More recently, nanostructures for drug and gene delivery via liposomes and cationic polymers are on focus to generate therapeutic devices and vaccines. Overall, the main aim of this article is to provide an overview of the methods currently used for DNA immobilization regarding the variety of DNA and surface structures for different applications.
Prescribed performance control of Euler–Lagrange systems with input saturation and output constraints
Authors: Zhang Jie , Yang Jing , Zhang Zhongcai , Wu Yuqiang
Published: September 2022

In this article, we investigate the performance‐guaranteed tracking control for Euler–Lagrange (EL) systems subject to input saturation and output constraints. The prescribed performance and output constraints are first considered for EL systems with input saturation. Time‐varying barrier Lyapunov function (BLF) is employed to ensure constraint satisfaction. An adaptive control method for EL systems with saturation is put forward by adding a speed transformation into the BLF and designing auxiliary variables to the system. Subsequently, neural network is introduced to compensate for uncertainties of systems. In combination with backstepping technique, it is demonstrated that the controller not only guarantees that the tracking error converges to a preset compact set near zero at a specified decay rate, but also ensures that the output always stays within a given boundary. Simulation results further demonstrate the effectiveness of the proposed control scheme.
Finite time fault tolerant tracking control for multiple unmanned aerial vehicles with actuator faults
Authors: Qian Moshu , Wu Zhu , Zhang Zhen , Bo Cuimei
Published: September 2022

An adaptive fast nonsingular integral terminal sliding mode control scheme is proposed for the distributed formation control problem of multiple unmanned aerial vehicles (UAVs) affected by actuator faults and external disturbances. In order to achieve a good cooperative tracking performance of UAVs during mission execution, the adverse effect of the lumped disturbances composed of actuator failures, wind and vortex disturbances is estimated by the cerebellar model articulation neural network, meanwhile the tangent function is introduced to eliminate the chattering of the sliding mode. Then the analysis of superior convergence performance of the fast nonsingular integral terminal sliding manifold is implemented, and the finite time stability of the closed‐loop formation flight control system is proved. Finally, the simulation experiments verify that the proposed approach is superior to the nonsingular integral terminal sliding mode control for the formation control system of faulty multiple UAVs.
Catalytic Self‐Assembled Air Electrode for Highly Active and Durable Reversible Protonic Ceramic Electrochemical Cells
Authors: He Fan , Liu Shuai , Wu Tong , Yang Meiting , Li Wenhuai , Yang Guangming , Zhu Feng , Zhang Hua , Pei Kai , Chen Yu , Zhou Wei , Shao Zongping
Published: September 2022

Reversible protonic ceramic electrochemical cells (R‐PCECs) is one of the most promising devices for efficient energy conversion and storage due to the high flexibility in reversible operation on dual modes of fuel cell and electrolysis cells. The key limitations of R‐PCECs performance lie mainly in the sluggish catalytic activity and poor durability of the air electrode for oxygen evolution/reduction reactions under realistic operating conditions. Herein, the findings on the development of highly active and durable air electrodes, achieved by a catalytic self‐assembly of Ba2Co1.5Mo0.25Nb0.25O6−δ (BC1.5MN) composite electrode, are reported. Under high‐temperature firing conditions, BC1.5MN is elegantly decomposed to a single‐perovskite BaCoO3−δ (SP‐BCO) and a double‐perovskite Ba2−xCo1.5−xMo0.5Nb0.5O6−δ (DP‐BCMN). Furthermore, fuel‐electrode‐supported full cells with BC1.5MN air electrode exhibit outstanding performance at 650 °C, achieving a peak power density of 1.17 W cm−2 and an electrolysis current density of 2.04 A cm−2 at 1.3 V. More importantly, the cells demonstrate excellent operation durability over 1100 h in fuel cell mode and exceptional cell cycling stability over 110 times within 220 h in dual modes of fuel cell and electrolysis cell. It is experimentally suggested that the catalytic durability is optimized by strong interaction between BCO and BCMN.
Resistance Drift Convergence and Inversion in Amorphous Phase Change Materials
Authors: Pries Julian , Stenz Christian , Schäfer Lisa , Gutsche Alexander , Wei Shuai , Lucas Pierre , Wuttig Matthias
Published: September 2022

Phase change materials (PCMs) are key to the development of artificial intelligence technologies such as high‐density memories and neuromorphic computing, thanks to their ability for multi‐level data storage through stepwise resistive encoding. Individual resistance levels are realized by adjusting the crystalline and amorphous volume fraction of the memory cell. However, the amorphous phase exhibits a drift in resistance over time that has so far hindered the commercial implementation of multi‐level storage schemes. In this study, the underlying physical process of resistance drift with the goal of modeling is elucidated that will help minimize and potentially overcome drift in PCM memory devices. Clear evidence is provided that the resistance drift is dominated by glass dynamics. Resistivity convergence and drift inversion for the amorphous chalcogenide Ge15Te85 and the PCM Ge3Sb6Te5 are experimentally demonstrated and these changes are successfully predicted with a glass dynamics model. This new insight into the resistance drift process provides tools for the development of advanced PCM devices.
A Novel Design Based on Mechanical Time‐Delay Switch and Charge Space Accumulation for High Output Performance Direct‐Current Triboelectric Nanogenerator
Authors: Du Yan , Fu Shaoke , Shan Chuncai , Wu Huiyuan , He Wencong , Wang Jian , Guo Hengyu , Li Gui , Wang Zhao , Hu Chenguo
Published: September 2022

Triboelectric nanogenerator (TENG), which converts mechanical energy into electrical energy, has become a promising environment energy harvesting technology. However, traditional TENG, based on the coupling of contact electrification and electrostatic induction, generates alternating current (AC) directly, which requires a rectifier to obtain direct current (DC) before being used to drive electronics. There are a few methods to obtain DC output including mechanical rectifier, phase coupling, air breakdown, and Schottky contact. But to achieve high output and high durability of DC‐TENG, new exploration is desired. In this study, a novel DC‐TENG is proposed, which greatly improves the output performance by designing a mechanical time‐delay switch and an alternative blank‐tribo‐area. The working mechanism of the DC‐TENG is analyzed theoretically and verified by experiments. It is found that the blank‐tribo‐area promotes charge accumulation, while the mechanical time‐delay switch realizes DC output. This DC‐TENG can light up 1888 LEDs in series at 60 rpm and drive 24 hygro‐thermographs in parallel with 120 rpm. The ultra‐high average power density of 4.2 W m−2 is achieved, much higher than previous works. The DC‐TENG displays high durability and retains 92% initial output after 120 000 cycles. This st provides a feasible strategy to boost the output performance of DC‐TENG.
Heterogeneous Nitride Interface Enabled by Stepwise‐Reduction Electrolyte Design for Dense Li Deposition in Carbonate Electrolytes
Authors: Zhu Zhenglu , Liu Zhikang , Zhao Ruirui , Qi Xiaoqun , Ji Jie , Yang Fengyi , Qie Long , Huang Yunhui
Published: September 2022

Stable solid electrolyte interphase (SEI) with high Li+‐ion conductivity is desperately desired for lithium (Li) metal anodes. However, it remains challenging to build a robust SEI rationally for the Li‐metal anodes in carbonate electrolytes. Herein, a heterogeneous nitride‐rich SEI that consists of organic nitrides on the surface and inorganic nitrides inside by stepwise‐reduction electrolyte design is constructed. The heterogeneous structure endows SEI with the capability to capture and distribute Li+ on the surface and facilitate internal Li+ transportation, leading to the redistributed Li+ flux and uniform Li electrodeposition. With the newly‐formulated carbonate electrolyte, Li||Cu cells deliver a high Coulombic efficiency of 98.0% after 300 cycles at 0.5 mA cm‐2 and 0.5 mAh cm‐2. Meanwhile, superb cycling stability is also determined with full Li‐metal cells using LiNi1/3Mn1/3Co1/3O2 and high‐loading LiFePO4 (12.0 mg cm−2) cathodes. This study provides a promising strategy to regulate the SEI components and stabilize the Li anodes by rational electrolyte design.
Ultrafast Activation and Tuning of Topological Textures in Ferroelectric Nanostructures
Authors: Prosandeev Sergey , Prokhorenko Sergei , Nahas Yousra , Grollier Julie , Talbayev Diyar , Dkhil Brahim , Bellaiche Laurent
Published: September 2022

Polar topological textures are recently discovered in ultra‐thin ferroelectrics, including stripe, labyrinth, or bubble states. Enabling to shape on‐demand, these topologies can provide an original platform for potential applications. Here, using first‐principle‐based calculations, it is shown that THz electric field pulses are an efficient means for generating a plethora of topological states in ultrathin films made by a prototypical ferroelectric system, depending on the characteristics of these pulses and films. Consequently, these ultrafast electrical pulses in ultra‐thin ferroelectrics offer key ingredients for mimicking neuronal and synaptic behaviors, including all‐optical devices, and open a new avenue for topological objects to neuromorphic systems.
2D Metal–Organic Framework Based Optoelectronic Neuromorphic Transistors for Human Emotion Simulation and Neuromorphic Computing
Authors: Liu Dapeng , Shi Qianqian , Zhang Junyao , Tian Li , Xiong Lize , Dai Shilei , Huang Jia
Published: September 2022

2D metal–organic frameworks (2D‐MOFs) have been extensively studied as promising materials in the fields of electrocatalysis, drug delivery, electronic devices, etc. However, few studies have explored the application potential of 2D‐MOFs in novel neuromorphic computing devices. Herein, an optoelectronic neuromorphic transistor based on a 2D‐MOF/polymer charge‐trapping layer is reported. It is found that the large specific surface area, stable crystal structure, and highly accessible active sites in 2D‐MOFs make them excellent charge‐trapping materials for the devices, which are beneficial for mimicking the memory and learning functions observed in the organism's nervous systems. Different types of synaptic behaviors have been realized in the 2D‐MOF‐based neuromorphic devices under stimuli signal, e.g., paired‐pulse facilitation, excitatory postsynaptic current, short‐term memory, and long‐term memory. More interestingly, emotion‐adjustable learning behavior is realized by changing the value of the source–drain voltage. This work can shed light on the application of 2D‐MOFs in neuromorphic computing and will contribute to the further development of neuromorphic computing devices. An interactive preprint version of the article can be found at DOI: https://doi.org/10.22541/au.165530836.62586068/v1.
Reduced resource utilization with early use of next‐generation sequencing in rare genetic diseases in an Asian cohort
Authors: Nazeha Nuraini , Koh Ai Ling , Kam Sylvia , Lim Jiin Ying , Goh Denise Li Meng , Jamuar Saumya Shekhar , Graves Nicholas
Published: September 2022

Children with genetic diseases endure a prolonged and costly “diagnostic odyssey.” The use of whole exome sequencing (WES) and whole genome sequencing (WGS) has improved the diagnosis rate, ending the odyssey. However, the additional costs associated WES/WGS has impeded their adoption in Asian settings. We aim to estimate the expected change to the mean number of diagnostic tests used, and the associated costs from a decision to use WES early in the diagnostic pathways of pediatric phenotypes, as compared to Existing Practice. Retrospective data from a patient cohort recruited under the Singapore Undiagnosed Disease Program from a tertiary hospital in Singapore, for the period October 2004 to September 2020, was analyzed. Four phenotype‐specific subgroups were used: multiple congenital anomalies (MCA) without developmental delay; global developmental delay (GDD); neuromuscular disorder (NMD) and primary immunodeficiency disorder (PID). Patients had undergone a traditional diagnostic pathway and received a diagnosis either through clinical exome or WES or WGS. A costs only analysis was performed, by tabulating the outcomes “test quantity” and “test costs” incurred by patients. The outcomes were compared with alternate diagnostic pathways which incorporates the early introduction of WES trio testing. To include uncertainty in cost outcomes, simulation studies were done on uncertain parameters. Cost outcomes are reported in Singapore dollars (S$). The 92 included patients had MCA (n = 48), GDD (n = 29), NMD (n = 10), or PID (n = 5). Patients were aged between 18 days and 26 years, 52.2% were males. The majority were of Chinese ethnicity (81.5%). If patients had access to WES directly, test quantity reduced by 97.38% for MCA, 96.98% for GDD, 96.56% for NMD, and 99.84% for PID. The expected cost savings per patient were $5940 for MCA (US$4433), $5342 for GDD (US$3986), $4622 for NMD (US$3449), and $58,497 for PID (US$43,654). Uncertainty assessment for MCA and GDD patients showed a respective likelihood of 86.9% and 97.4% for cost savings. Adoption of alternate diagnostic pathways with early WES in selected pediatric subgroups are likelt to reduce costs, when compared to Existing Practice. Benefits arising from earlier diagnosis, and the potential cost savings could mitigate the large initial cost of implementing WES in Asian settings.
Effect of microwave—Chemical modification on properties of soybean meal‐based wood adhesive
Authors: Li Mengmeng , Wang Ruihu , Wang Haijie , Cao Xinhua , Cheng Yu , Guan Erqi , Bian Ke
Published: September 2022

To enlarge the industrial application of plywood made from soybean meal‐based adhesive (SMA), the properties improvement, especially wet shear strength of SMA which was modified by microwave‐chemical treatment was studied. The purpose of this research was to optimize microwave conditions combined with polyethylene glycol (PEG) and polyethyleneimine (PEI) treatment, to maximize the water resistance of SMA. The viscosity, shear strength and solids content of modified SMA were determined. In addition, the modified mechanism was characterized by using Fourier transform infrared spectroscopy, Scanning electron microscope, X‐ray diffraction and thermogravimetric analysis. Results indicated that the wet shear strength of SMA reached at 0.93 MPa when the microwave power was 350 W, microwave time was 3 min, and concentration of soybean meal was 28%. The result was 32.86% higher than China National Standard for interior use of plywood (≥0.70 MPa). From the results of mechanism, the bonding performance of the prepared plywood was improved after PEG‐PEI and microwave modification, which improved the water resistance of SMA. The improvement due to the formation of crosslinking in curing process by the reaction between active groups of soybean protein molecules and crosslinking agent under microwave modification, which provided favorable conditions for further application of SMA.
Hybrid solid sensitive arrays/polypropylene composites: A study on sensing alkaline vapors
Authors: Cichero Matheus Costa , dos Santos da Silva Alan , dos Santos João Henrique Z.
Published: September 2022

Solid alkaline sensors containing polypropylene (PP) and four different bromocresol purple‐based multilayered hybrid sensitive materials (using silica and polymethacrylic acid [PPMA]) were synthesized. The material was used to sense two alkaline vapors: ammonia and volatile basic nitrogen (VBN) from fish deterioration. The sensor performances were analyzed by color evaluation, the mechanical properties were assessed by tensile tests, and the dispersion of the sensitive materials into the PP matrix was analyzed by X‐ray computed microtomography. Three of the four composites exhibited sensitivity toward ammonia vapors, with values of ∆E*ab > 5; however, the sensitive composites showed lower sensitivity toward VBN, with values of ∆E*ab < 3.5. The samples showed an elongation at break below 5%, which is characteristic of brittle materials. The X‐ray computed microtomography analysis revealed that the PMAA‐based hybrid sensor exhibited better dispersion in the PP matrix than the silica‐based sensor.
Supporting long‐term sustainability of ex situ collections using a pedigree‐based population management approach
Authors: Foster Jeremy A. , Walsh Seana K. , Havens Kayri , Kramer Andrea T. , Fant Jeremie B.
Published: September 2022

Premise

Living collections maintained for generations are at risk of diversity loss, inbreeding, and adaptation to cultivation. To address these concerns, the zoo community uses pedigrees to track individuals and implement crosses that maximize founder contributions and minimize inbreeding. Using a pedigree management approach, we demonstrate how conducting strategic crosses can minimize genetic issues that have arisen under current practices.

Methods

We performed crosses between collections and compared progeny fitness, including plant performance and reproductive health. We genotyped the progeny and parental accessions to measure changes in diversity and relatedness within and between accessions.

Results

The mean relatedness values among individuals within each accession suggest they are full siblings, demonstrating that there was high inbreeding and low diversity within accessions, although less so among accessions. Progeny from the wider crosses had increased genetic diversity and were larger and more fertile, while self‐pollinated accessions were smaller and less fertile.

Discussion

Institutions that hold exceptional species should consider how diversity is maintained within their collections. Implementing a pedigree‐based approach to managing plant reproduction ex situ will slow the inevitable loss of genetic diversity and, in turn, result in healthier collections.
In‐situ Polymerization Methods for Polymer‐based Solid‐State Lithium Batteries
Authors: Sun Mengjun , Zeng Ziqi , Zhong Wei , Han Zhilong , Peng Linfeng , Cheng Shijie , Xie Jia
Published: September 2022

The in‐situ polymerization methods (in‐situ methods) have led to huge advancement in the development of solid‐state batteries (SSBs) with intimate interfacial contacts and continuous pathways for the conduction of lithium ion. Though promising, they still face obstacles that hinder their practical application, such as poor interfacial stability between initiators and electrodes and scalability challenges. To date, most studies have been largely focused on the discovery of novel monomers/oligomers that can be in‐situ polymerized. Additionally, recent reviews have examined the progress of monomers/oligomers and advantages of in‐situ methods. Recognizing this, in this review, we seek to summarize in‐situ methods from the viewpoint of initiators. We provide realistic assessments of interfacial stability of initiators with electrodes, and analyze their challenges and perspectives for actual application. We hope to inspire deeper considerations on selection of initiators and offer guidance for in‐situ preparation of SSBs with high performances.
Automatisierte Klassifizierung von Schäden an Massivbrücken mittels Neuronaler Netze
Authors: Flotzinger Johannes , Braml Thomas
Published: September 2022

Vor dem Hintergrund eines alternden Bauwerksbestands sowie des stetigen Anstiegs des Schwerverkehrs ist eine regelmäßige und qualitativ hochwertige Bauwerksprüfung unabdingbar. Bei der Bewältigung dieser Aufgabe birgt die Zuhilfenahme digitaler Methoden im Rahmen der digitalisierten Inspektion (DI) großes Verbesserungspotenzial in Hinblick auf Wirtschaftlichkeit und Qualität. Ein wesentlicher Bestandteil der DI ist das automatisierte Erkennen von Schäden mit Künstlichen Neuronalen Netzen. Im Rahmen des Forschungsprojekts „Modellbasierte digitale Bauwerksprüfung – MoBaP“ werden an der Universität der Bundeswehr München Neuronale Netze für die Klassifizierung von Schäden an Massivbrücken trainiert. Auf dem derzeit größten Open‐Source‐Datensatz (CODEBRIM) dieser Domäne erzielt das im Folgenden dargestellte Netz eine Exact Match Ratio von 74 % und definiert damit das aktuell beste Modell zur Multi‐Target‐Klassifizierung. Um auch Neuronale Netze für die Objektdetektion und semantische Segmentierung dieser Domäne zu trainieren, wird ein eigener Datensatz erstellt. Dadurch wird neben dem Klassifizieren auch das Lokalisieren der Schäden auf Bildern ermöglicht. In diesem Aufsatz erörtern die Autoren das Vorgehen zum Trainieren Neuronaler Netze für die Klassifizierung von Schäden an Massivbrücken und eine detaillierte Analyse von Testergebnissen. Außerdem werden die Entwicklung und der aktuelle Stand eines eigenen Datensatzes vorgestellt.
Influence of cluster‐period cells in stepped wedge cluster randomized trials
Authors: Mildenberger Philipp , König Jochem
Published: September 2022

Stepped wedge cluster randomized trials (SWCRT) are increasingly used for the evaluation of complex interventions in health services research. They randomly allocate treatments to clusters that switch to intervention under investigation at variable time points without returning to control condition. The resulting unbalanced allocation over time periods and the uncertainty about the underlying correlation structures at cluster‐level renders designing and analyzing SWCRTs a challenge. Adjusting for time trends is recommended, appropriate parameterizations depend on the particular context. For sample size calculation, the covariance structure and covariance parameters are usually assumed to be known. These assumptions greatly affect the influence single cluster‐period cells have on the effect estimate. Thus, it is important to understand how cluster‐period cells contribute to the treatment effect estimate. We therefore discuss two measures of cell influence. These are functions of the design characteristics and covariance structure only and can thus be calculated at the planning stage: the coefficient matrix as discussed by Matthews and Forbes and information content (IC) as introduced by Kasza and Forbes. The main result is a new formula for IC that is more general and computationally more efficient. The formula applies to any generalized least squares estimator, especially for any type of time trend adjustment or nonblock diagonal matrices. We further show a functional relationship between IC and the coefficient matrix. We give two examples that tie in with current literature. All discussed tools and methods are implemented in the R package SteppedPower.
Dealing with stalking cases in Lithuania: The role of public perceptions and legal response
Authors: Laurinaitytė Ilona , Michailovič Ilona , Jarutienė Liubovė
Published: September 2022

Stalking is considered a dangerous form of victimization that requires an effective criminal justice response. In this current research, we aimed (1) to examine lifetime prevalence of stalking victimization and public perceptions of stalking as well as (2) to investigate the characteristics of stalking cases in recent court practice in Lithuania. In Study 1, a web‐based survey on a representative sample of 1517 respondents aged 18–87 years was conducted. In Study 2, an analysis of 100 court decisions was performed in stalking‐related criminal cases from 2016 to 2020. The research findings (i.e., stalking victimization and public perceptions of stalking phenomenon, coercive measures that were ordered in pre‐trial investigation, and sentences imposed closing the cases) are discussed in terms of the latest legal developments and existing response options, as well as considerations for future research.
Revelation of the transition‐metal doping mechanism in lithium manganese phosphate for high performance of lithium‐ion batteries
Authors: Zhang Bo , Wang Li , Zhang Hao , Xu Hong , He Xiangming
Published: September 2022

Lithium iron phosphate (LiFePO4) has been widely used due to its high theoretical capacity and good cycle stability, but lithium manganese phosphate (LiMnPO4) with a higher operating voltage (4.1 V) has not been used, so it is necessary to conduct theoretical research on its inherent performance improvement strategy. The large‐scale application of LiMnPO4 is limited by its relatively low electronic and ionic conductivity. Improving the electronic and ionic conductivity of electrode materials by selective doping is an effective strategy. To determine the effect of doping of transition metals on the electrochemical properties of LiMnPO4 and to screen out doping models of cathode materials with excellent battery performance, we established all 3d, 4d, and 5d transition‐metal doping models of LiMnPO4. Through screening by first principles, the structural properties, band gap, doping formation energy, elastic properties, isotropy, and lithium/delithium voltage of the above models were compared and analyzed. According to the screening results, LiMnPO4 doped with Sc, Ti, V, Fe, Co, Mo, Rh, Re, and Ir has excellent electrochemical properties and can be used as a good cathode material for lithium‐ion batteries; the inherent mechanism of the above materials is revealed.
Identification of prognostic indicators, diagnostic markers, and possible therapeutic targets among LIM homeobox transcription factors in breast cancer
Authors: Gao Pingping , Sun Na , Zhao Tingting , Sun Yuanyuan , Gu Jing , Ma Dandan , Tian Hao , Peng Zaihui , Zhang Yi , Han Fei , Qi Xiaowei
Published: September 2022

Background

Breast cancer (BRCA) is the most common malignant tumor among women worldwide. Despite advances in treatment, many patients still die from a lack of effective diagnostic and prognostic markers and powerful therapeutic targets. LIM homeobox genes (LHXs) play vital roles in regulating the development of various organisms. However, there are limited reports regarding their roles in the diagnosis, prognosis, and treatment of BRCA.

Methods

UALCAN, Kaplan–Meier plotter, cBioPortal, GeneMANIA, STRING, DAVID 6.8, TRRUST v2, LinkedOmics, and TIMER were utilized to analyze differential expression, prognostic value, genetic alteration, neighbor gene network, transcription factor targets, kinase targets, and immune cell infiltration of LHXs in BRCA patients.

Results

LHX gene expression patterns are clear in BRCA and its different subtypes. Further analyses indicated that this altered expression is possibly affected by genetic and/or epigenetic changes. The prognostic and diagnostic values of certain LHXs are unique to different BRCA subtypes. LHXs are mainly involved in the regulation of differentiation and development, and their neighbor genes are primarily involved in cancer‐related pathways. Moreover, most LHXs are closely correlated with immune cell infiltration. Furthermore, LHXs may exert their functions by regulating a series of transcription factor and kinase targets.

Conclusions

LHXs are unique diagnostic and prognostic markers and participate in cancer through different signaling pathways and/or regulatory mechanisms in BRCA. This study provides potential applications of LHXs for the diagnosis, prognosis, and treatment of BRCA and its different subtypes.
Biomarkers for pancreatic cancer based on tissue and serum metabolomics analysis in a multicenter study
Authors: Zhao Rui , Ren Shuai , Li Changyin , Guo Kai , Lu Zipeng , Tian Lei , He Jian , Zhang Kai , Cao Yingying , Liu Shijia , Li Donghui , Wang Zhongqiu
Published: September 2022

Background

Early detection of pancreatic ductal adenocarcinoma (PDAC) may improve the prognosis of patients. This study was to identify metabolic features of PDAC and to discover early detection biomarkers for PDAC by tissue and serum metabolomics analysis.

Methods

We conducted nontargeted metabolomics analysis in tissue samples of 51 PDAC tumors, 40 noncancerous pancreatic tissues (NT), and 14 benign pancreatic neoplasms (BP) as well as serum samples from 80 patients with PDAC, 36 with BP, and 48 healthy controls (Ctr). The candidate metabolites identified from the initial analysis were further quantified using targeted analysis in serum samples of an independent cohort of 22 early stage PDAC, 27 BP, and 27 Ctr subjects. Unconditional binary logistic regression analysis was used to construct the optimal model for PDAC diagnosis.

Results

Upregulated levels of fatty acids and lipids and downregulated amino acids were observed in tissue and serum samples of PDAC patients. Proline, creatine, and palmitic acid were identified as a panel of potential biomarkers to distinguish PDAC from BP and Ctr (odds ratio = 2.17, [95% confidence interval 1.34–3.53]). The three markers showed area under the receiver‐operating characteristic curves (AUCs) of 0.854 and 0.865, respectively, for the comparison of PDAC versus Ctr and PDAC versus BP. The AUCs were 0.830 and 0.852 in the validation set and were improved to 0.949 and 0.909 when serum carbohydrate antigen 19‐9 (CA19‐9) was added to the model.

Conclusion

The novel metabolite biomarker panel identified in this study exhibited promising performance in distinguishing PDAC from BP or Ctr, especially in combination with CA19‐9.
Porous Metal Organic Frameworks as Multifunctional Catalysts for Cyclohexane Oxidation
Authors: Dhakshinamoorthy Amarajothi , López‐Francés Anton , Navalon Sergio , Garcia Hermenegildo
Published: September 2022

Catalysis drives the conversion of substrates to the wanted products under amenable reaction conditions. In this context, one reaction that is particularly important from the industrial point of view is cyclohexane aerobic oxidation to a mixture of the corresponding cyclohexanone and cyclohexanol. This industrial oxidation is key for the production of Nylon 6 and Nylon 6,6, two polyamides of growing production. The industrial process is clearly unsatisfactory since it is run at low cyclohexane conversions to avoid the formation of complex mixtures, difficult to isolate. The present review shows the progress made in the use of metal‐organic frameworks as solid catalysts for this important reaction, with emphasis in the intrinsic activity of metal nodes, tuning of the polarity of the internal voids or incorporation of active metal nanoparticles. It is shown that using MOFs as catalysts, it is possible to reach high cyclohexane conversions, while the combined alcohol+ketone selectivity still close to the 90 % limit.
Evaluation and Optimization of an Export Gas Compressor in a Natural Gas Project
Authors: Noaman Abdelaziz A.
Published: September 2022

The possibility of removing the export gas compressor from the central process facilities (CPF) in a gas project and enlarging the size of the gas export pipeline from the CPF to reduce the total capital expenditure (CAPEX) and operating expenditure (OPEX) is evaluated. Adding the export gas compressor to the CPF will increase the carbon footprint of the CPF, the power requirements of the CPF, and the emission of greenhouse gases. The CPF equipment would be designed for a lower operating pressure which leads to larger equipment sizes. PIPESIM and HYSYS software were used to simulate the CPF and different sizes of the export gas pipeline. With an export gas pipeline size smaller than 24”, an export gas compressor is required for the CPF, and as the pipeline size is reduced, the compressor power requirement will rise. CAPEX and OPEX comparisons were conducted between adding the export gas compressor or enlarge the size of the export gas pipeline. CAPEX and OPEX decline with larger pipeline size.
Atomic‐level insight of sulfidation‐engineered Aurivillius‐related Bi2O2SiO3 nanosheets enabling visible light low‐concentration CO2 conversion
Authors: Wang Kai , Du Yue , Li Yuan , Wu Xiaoyong , Hu Haiyan , Wang Guohong , Xiao Yao , Chou Shulei , Zhang Gaoke
Published: September 2022

Unraveling atomic‐level active sites of layered photocatalyst towards low‐concentration CO2 conversion is still challenging. Herein, the yield and selectivity of photocatalytic CO2 reduction of the Aurivillius‐related oxide semiconductor Bi2O2SiO3 nanosheet (BOSO) were largely improved using a surface sulfidation strategy. The experiment and theoretical calculation confirmed that surface sulfidation of the Bi2O2SiO3 nanosheet (S‐BOSO, 6.28 nm) redistributed the charge‐enriched Bi sites, extended the solar spectrum absorption to the whole visible range, and considerably enhanced the charge separation, in addition to creating new reaction active sites, as compared to pristine BOSO. Subsequently, surface sulfidation played a switchable role, wherein S‐BOSO showed a very high CH3OH generation rate (12.78 µmol g−1 for 4 h, 78.6% selectivity) from low‐concentration CO2 (1000 ppm) under visible light irradiation, which outperforms most of the state‐of‐the‐art photocatalysts under similar conditions. This study presents an atomic‐level modification protocol for engineering reactive sites and charge behaviors to promote solar‐to‐energy conversion.
Prediction of asphaltene adsorption capacity of clay minerals using machine learning
Authors: Ghasemi Mehdi , Tatar Afshin , Shafiei Ali , Ivakhnenko Oleksandr P.
Published: September 2022

A thorough understanding of asphaltene adsorption on clay minerals is particularly important in oil production and contaminated soil remediation using clay‐based adsorbents. In this paper, we introduced a machine learning approach as a reliable alternative for commonly used adsorption isotherms that suffer from inherent limitations in the prediction of asphaltene adsorption onto clay minerals. Machine learning (ML) models, namely multilayer perceptron (MLP), support vector machine (SVM), decision tree (DT), random forest (RF), and committee machine intelligent system (CMIS) combined with two optimizers were used. Experimental data (142 data points for six different clay minerals) was used for the modelling. To improve the accuracy of the smart models, a comprehensive data preparation such as outlier removal and feature selection was carried out. The results showed that relatively all the proposed models predict asphaltene adsorption on clay minerals with acceptable precision. Nevertheless, the MLP model showed superior performance compared with other models in which the overall root mean square error (RMSE) and coefficient of determination (R2) values of 6.72 and 0.93 were obtained, respectively. Finally, the developed MLP model was compared with the well‐known adsorption isotherms of Langmuir and Freundlich and exhibited superior performance.
Convenient Synthesis of Thioester‐Substituted Oxindoles by Palladium‐Catalyzed Thiocarbonylative Cyclization with Sulfonyl Chlorides as the Sulfur Source
Authors: Xu Ren‐Rui , Fang Xiuyu , Qi Xinxin , Wu Xiao‐Feng
Published: September 2022

Comprehensive Summary

A general and straightforward strategy for the synthesis of thioester‐substituted oxindoles via a palladium‐catalyzed thiocarbonylative cyclization process has been developed. With sulfonyl chlorides as promising sulfur source, a wide range of thioester‐substituted oxindoles were obtained in moderate to high yields. Both aryl and alkyl sulfonyl chlorides were well tolerated, and Mo(CO)6 played a dual role as both a CO source and a reductant in this approach.