bluuebunny/crossref_metadata_2025 huggingface dataset:
A promising low‐dielectric‐constant material with good comprehensive performance upon heating
Authors: Ma Yingyi , He Zian , Han Yuhang
Published: February 2023

The dielectric and other properties of low‐dielectric‐constant materials after heating are crucial to their performance and use, but rarely studied. In this article, sandwich‐type porous polyimide (PI) film in which porous structures located on both upper and lower surfaces of flat PI film was prepared through the simple, low‐cost and green microemulsion method. The porous structures were preserved after heating due to the usage of thermally stable fluorine‐contained PI (FPI) and PI as skeleton and substrate of the porous structure, respectively, but with the increase of pore size because of the removal of thermally unstable surfactant on the inner surface of the pores. More importantly, 2.89%–5.57% of reductions in the dielectric constant with the maintenance of low dielectric loss and water absorption and high mechanical strength were observed after heating. Therefore, the low dielectric properties of heated films were well preserved upon high humidity treatment. Moreover, the structure and properties of the heated films could be adjusted via controlling the parameters in the microemuslion method. These excellent properties after the high‐temperature treatment facilitate the application of the sandwich‐type porous PI film as dielectric materials in high‐temperature environment.
Circularity assessment of logistics activities for green business performance management
Authors: Berberoglu Yalcin , Kazancoglu Yigit , Sagnak Muhittin
Published: February 2023

The population of the world is increasing, and product demand is increasing, making a linear economy ineffective, and therefore, this situation makes the circular economy (CE) a requirement. Economic, social, and environmental factors all play a role in the CE. Also, logistics activities are critical parts of the CE. Hence, this study's goal is to create a framework for evaluating organizations' CE logistics performance. The main contribution of the study is the creation of a framework to assess the circularity performance, including various logistics activities, and measure the performance of logistics activities. To establish a list of criteria, 30 experts were interviewed. The criteria were ranked using fuzzy statements. The selected multi‐criteria decision‐making (MCDM) method, data envelopment analysis, is applied using IBM ILOG CPLEX Optimization Studio version 20.1.0.
Virtual scene generation promotes shadow puppet art conservation
Authors: Liang Hui , Dong Xiaohang , Pan Junjun , Zheng Xiangyu
Published: February 2023

As an ancient performing art, shadow puppetry is a treasure of Chinese art. However, with the development of society, shadow puppetry becomes less well‐known among the young generation. To preserve and further spread this traditional culture, the digitization of shadow puppets is playing an increasingly important role in shadow puppetry conservation. Despite this, the spread of shadow puppetry culture in modern times still faces many hindrances. In digitalized shadow puppet art, the virtual scenes in certain degree determine the artistic effect of shadow puppet performance. The commonly used method for digital shadow puppet scene construction is via artificially created models which are then placed in corresponding positions. Obviously, this is a cumbersome and time‐consuming task. Therefore, a semantic‐based scene generation method for digital shadow puppet performance scene is proposed in this paper. According to this method, the key information is extracted from the descriptive text using the Chinese text segmentation technology. Meanwhile, we generate semantic scene graphs and search the corresponding shadow puppet models in the model library to construct the virtual scenes of digital shadow puppet performance. In the evaluation experiment, we invited 30 volunteers (10 female and 20 male) who had been exposed to traditional shadow puppet play in their daily lives. As suggested by the experimental results, the digital shadow puppet performance scene generated in this paper exhibit advantages of convenient use and high availability, which largely enhance the effect of digital shadow puppet performance. It should nonetheless be noted that it's not easy to extract the spatial relations from complicated texts, which inevitably limits the effectiveness of our scene generation method. The research work of this paper aims to promote digital shadow puppet technology and provide insights for the inheritance and conservation of traditional shadow puppet art.
A Detailed View on Geosmin Biosynthesis
Authors: Xu Houchao , Dickschat Jeroen S.
Published: February 2023

The bacterial geosmin synthase is a fascinating bifunctional enzyme that has been discovered almost two decades ago. Several aspects of the cyclisation mechanism from FPP to geosmin are known, but a detailed picture of the stereochemical course of this reaction is unknown. This article reports on a deep investigation of the mechanism of geosmin synthase through isotopic labelling experiments. Furthermore, the effects of divalent cations on geosmin synthase catalysis were investigated. The addition of cyclodextrin to enzymatic reactions, a molecule that can capture terpenes, suggests that the biosynthetic intermediate (1(10)E,5E)‐germacradien‐11‐ol produced by the N‐terminal domain is passed to the C‐terminal domain not through a tunnel, but rather through release into the medium and uptake by the C‐terminal domain.
Organophotocatalytic Mechanisms: Simplicity or Naïvety? Diverting Reactive Pathways by Modifications of Catalyst Structure, Redox States and Substrate Preassemblies
Authors: Mandigma Mark John P. , Kaur Jaspreet , Barham Joshua P.
Published: February 2023

Photocatalysis is a powerful tool to assemble diverse chemical scaffolds, yet a bottleneck on its further development is the understanding of the multitude of possible pathways when practitioners rely only on oversimplified thermodynamic and optical factors. Recently, there is a growing number of studies in the field that exploit, inter alia, kinetic parameters and organophotocatalysts that are synthetically more programmable in terms of their redox states and opportunities for aggregation with a target substrate. Non‐covalent interactions play a key role that enables access to a new generation of reactivities such as those of open‐shell organophotocatalysts. In this review, we discuss how targeted structural and redox modifications influence the organophotocatalytic mechanisms together with their underlying principles. We also highlight the benefits of strategies such as preassembly and static quenching that overcome common reactivity issues (e. g., diffusion rate limits and energetic limits).
Calcium‐Modified PtSn/Al2O3 Catalyst for Propane Dehydrogenation with High Activity and Stability
Authors: Gao Xin‐Qian , Yao Zi‐Hao , Li Wen‐Cui , Deng Gao‐Ming , He Lei , Si Rui , Wang Jian‐Guo , Lu An‐Hui
Published: February 2023

Catalytic dehydrogenation of propane to propylene and by‐product hydrogen is an atom‐economical and environmentally friendly route. PtSn/Al2O3 catalysts have been industrialized in this process, but still suffer from platinum sintering and coke deposition under reaction conditions. Herein, we design a calcium‐modified PtSn/Al2O3 catalyst showing a superior propane dehydrogenation performance. The presence of calcium combined with unsaturated aluminum and tin could consist of a new local microenvironment that promotes the dispersion of the platinum species and increases the electron density of the platinum species, which improves the catalytic activity, facilitates propylene desorption and inhibits coke formation. As a result, the achieved PtSnCa/Al2O3 catalyst exhibits a higher propylene formation rate and a lower coke‐accumulation rate compared to the catalyst without Ca addition. Moreover, the size of active phase clusters (∼1 nm) remained almost unchanged after the catalytic test, indicating a superior sintering resistance.
Characterization of Fragile X Mental Retardation Protein expression in human nociceptors and their axonal projections to the spinal dorsal horn
Authors: Mitchell Molly E. , Cook Lauren C. , Shiers Stephanie , Tavares‐Ferreira Diana , Akopian Armen N. , Dussor Gregory , Price Theodore J.
Published: February 2023

Fragile X Mental Retardation Protein (FMRP) regulates activity‐dependent RNA localization and local translation to modulate synaptic plasticity throughout the central nervous system. Mutations in the FMR1 gene that hinder or ablate FMRP function cause Fragile X Syndrome (FXS), a disorder associated with sensory processing dysfunction. FXS premutations are associated with increased FMRP expression and neurological impairments including sex dimorphic presentations of chronic pain. In mice, FMRP ablation causes dysregulated dorsal root ganglion (DRG) neuron excitability and synaptic vesicle exocytosis, spinal circuit activity, and decreased translation‐dependent nociceptive sensitization. Activity‐dependent, local translation is a key mechanism for enhancing primary nociceptor excitability that promotes pain in animals and humans. These works indicate that FMRP likely regulates nociception and pain at the level of the primary nociceptor or spinal cord. Therefore, we sought to better understand FMRP expression in the human DRG and spinal cord using immunostaining in organ donor tissues. We find that FMRP is highly expressed in DRG and spinal neuron subsets with substantia gelatinosa exhibiting the most abundant immunoreactivity in spinal synaptic fields. Here, it is expressed in nociceptor axons. FMRP puncta colocalized with Nav1.7 and TRPV1 receptor signals suggesting a pool of axoplasmic FMRP localizes to plasma membrane‐associated loci in these branches. Interestingly, FMRP puncta exhibited notable colocalization with calcitonin gene‐related peptide (CGRP) immunoreactivity selectively in female spinal cord. Our results support a regulatory role for FMRP in human nociceptor axons of the dorsal horn and implicate it in the sex dimorphic actions of CGRP signaling in nociceptive sensitization and chronic pain.
Development of urban underground space in coastal cities in China: A review
Authors: Yu Peng , Liu Honghua , Wang Zhongsheng , Fu Jiani , Zhang Hui , Wang Jia , Yang Qi
Published: February 2023

The development of urban underground space is a critical way to alleviate the lack of urban resources, and improve environmental conditions as well as residents' quality of life, which has important practical significance. As the most densely populated and economically developed areas, coastal cities face many challenges in underground space development owing to their unique environmental geological conditions. This study examined the current situation of underground space development, academic research, technology application, evaluation methods, planning, and legislation in coastal cities in China. On this basis, it analyzed the future development trends, and presented reasonable suggestions for the critical scientific and technical problems faced by the development of underground space in coastal cities. The key suggestions are as follows: it is necessary to define and clarify the critical geological issues, distributions, and hazards that affect underground space development and major engineering construction in coastal cities; the land‐sea integrated detection technology for sea crossing bridges and submarine tunnels needs to be studied; in evaluating the suitability of underground space in coastal cities, the land and sea area evaluation factors should be integrated; and the evaluation system of land‐sea integration needs to be established.
Can polycentric governance lower industrial greenhouse gas emissions: Evidence from the United States
Authors: Daley Dorothy M. , Abel Troy D. , Stephan Mark , Rai Saatvika , Rogers Ellen
Published: February 2023

The governance challenges embedded in climate change are daunting. Conventional logic holds that national and international action is necessary. While the United States is a major source of Greenhouse Gas (GHG) emissions – second only to China – national action on climate change has been lacking. However, hundreds of subnational US governments and thousands of industrial facilities are actively engaged in addressing climate change. Given the potential mismatch between the global nature of the problem and the policy reach of subnational governments, we evaluate the extent to which polycentric variation in subnational climate action is associated with changes in GHG emissions. We develop a unique data set that incudes facility‐level GHG emissions from major industrial sectors in the United States over 8 years and subnational climate governance action across all 50 states. This large‐N data set allows us to systematically test hypothesis from polycentric governance. This type of comparative analysis can help to better understand the conditions under which polycentric governance is associated with improved climate change outcomes, that is, declining GHG emissions. Our results suggest that even when controlling for past emissions, some elements of polycentric governance are associated with decreases in GHG emissions. Future research would benefit from augmenting the large N comparative analysis presented here with mixed methods research to more fully understand the dynamic processes shaping both climate policy and GHG emissions.
The creative ways colleges are reinventing themselves to avoid demographic declines
Authors: D'Orio Wayne
Published: February 2023

There's no arguing with the demographics. Starting in 2025, the number of high school graduates will decline by 100,000 annually for four years, https://tinyurl.com/2st6c896. And the shrinking number of graduates will persist at least 15 years.
Clearing your plate for more purpose‐driven work
Authors: Freebairn‐Smith Laura
Published: February 2023

Recently I wrote about the Management Progression model which shows the progression a person makes into management, moving from a high level of content focus to a primary focus on managing and leading.
Statistical characterization of erosion and sediment transport mechanics in shallow tidal environments. Part 1: erosion dynamics
Authors: D'Alpaos Andrea , Tognin Davide , Tommasini Laura , D'Alpaos Luigi , Rinaldo Andrea , Carniello Luca
Published: February 2023

Wave-induced bottom shear stress is one of the leading processes that
control sediment erosion dynamics in shallow tidal environments, because
it is responsible for sediment resuspension and, jointly with tidal
currents, for sediment reworking on tidal flats. Reliable descriptions
of erosion events are foundational to effective frameworks relevant to
the fate of tidal landscape evolution. However, the absence of
long-term, measured time series of bottom shear stress (BSS) prevents a
direct analysis of erosion dynamics. Here we adopted a fully-coupled,
bi-dimensional numerical model to compute BSS generated by both tidal
currents and wind waves in six historical configurations of the Venice
Lagoon in the last four centuries. The one-year-long time series of the
total BSS were analyzed based on the peak-over-threshold theory to
statistically characterize events that exceed a given erosion threshold
and investigate the effects of morphological modifications on spatial
and temporal erosion patterns. Our analysis suggests that erosion events
can be modeled as a marked Poisson process in the intertidal flats for
all the considered configurations of the Venice Lagoon, because
interarrival times, durations and intensities of the over-threshold
exceedances are well described by exponentially distributed random
variables. Moreover, while the intensity and duration of over-threshold
events are temporally correlated, almost no correlation exists between
them and interarrival times. The resulting statistical characterization
allows for a straightforward computation of morphological indicators,
such as erosion work, and paves the way to a novel synthetic, yet
reliable, approach for long-term morphodynamic modeling of tidal
environments.
Bioaccumulation Kinetics of Model Pharmaceuticals in the Freshwater Unionid Pondmussel, Sagittunio subrostratus
Authors: Burket S. Rebekah , Sims Jaylen L. , Dorman Rebecca , Kemble Nile , Brunson Eric , Steevens Jeffery A. , Brooks Bryan W.
Published: February 2023

Bioaccumulation of ionizable pharmaceuticals has been increasingly studied, with most reported aquatic tissue concentrations in field or laboratory experiments being from fish. However, higher levels of antidepressants have been observed in bivalves compared with fish from effluent-dominated and dependent surface waters. Such observations may be important for biodiversity because approximately 70% of freshwater bivalves in North America are considered to be vulnerable to extinction. Because experimental bioaccumulation information for freshwater bivalves is lacking, we examined accumulation dynamics in the freshwater pondmussel, Sagittunio subrostratus, following exposure to a model weak acid, acetaminophen (mean (±SD) = 4.9 ± 1 µg L–1), and a model weak base, sertraline (mean (±SD) = 1.1 ± 1.1 µg L–1) during 14-day uptake and 7-day depuration experiments. Pharmaceutical concentrations were analyzed in water and tissue using isotope dilution liquid chromatography–tandem mass spectrometry. Mussels accumulated two orders of magnitude higher concentrations of sertraline (31.7 ± 9.4 µg g–1) compared to acetaminophen (0.3 ± 0.1 µg g–1). Ratio and kinetic-based bioaccumulation factors of 28,836.4 (L kg–1) and 34.9 (L kg–1) were calculated for sertraline and for acetaminophen at 65.3 (L kg–1) and 0.13 (L kg–1), respectively. However, after 14 days sertraline did not reach steady-state concentrations, although it was readily eliminated by S. subrostratus. Acetaminophen rapidly reached steady-state conditions but was not depurated over a 7-day period. Future bioaccumulation studies of ionizable pharmaceuticals in freshwater bivalves appear warranted. Environ Toxicol Chem 2023;42:1183–1189. © 2023 SETAC. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.
Mixed Germania‐Silica Films on Ru(0001): A Combined Experimental and Theoretical Study
Authors: Fuhrich Alexander , Paier Joachim , Tosoni Sergio , Leandro Lewandowski Adrián , Gura Leonard , Schneider Wolf‐Dieter , Pacchioni Gianfranco , Freund Hans‐Joachim
Published: February 2023

Two‐dimensional oxide films are potentially useful for future technological applications, but also important objects to study model catalyst systems on the more fundamental side. Here we study silica, germania, and mixed silica‐germania films supported on a metal single crystal surface Ru(0001). Those mixed films are interesting objects to systematically modify the properties of silica films, which may be used as membranes or covers for model studies in confined space, due to the modification of the rather stiff silica layers by incorporating germanium atoms replacing silicon atoms. Here we report a combined experimental and theoretical study of such layers, where we show how X‐ray photoelectron spectroscopy in combination with LEED and I/V LEEM measurements allow us to judge the formation of such mixed films.
Optimal design of a periodic‐move sprinkler irrigation system considering pump characteristics
Authors: Sithole Thandokuhle Nkululeko , Singh Rajesh P. , Mahar Pooran S.
Published: February 2023

An optimisation model is developed for designing a single‐ and two‐pipe size periodic‐move sprinkler lateral for various values of uniform upward and downward slopes. Two layouts are considered, and the optimisation model maximizes the length of the main line subject to a minimum desirable pump efficiency and an allowable pressure variation without throttling the pump at the lateral inlet. The step‐by‐step approach is used for computing the frictional head loss of the pipelines for analysis of sprinkler pressure heads. The head‐discharge characteristics of sprinkler heads, the pipe characteristics of the lateral and main lines and the pump characteristics are matched to determine the optimal diameter and length of the main line and diameter of the lateral line. The applicability of the optimisation models are illustrated by solving standard design problems using LINGO 18.0. Larger pipe diameters for single‐ and two‐pipe size laterals resulted in an increase in the length of the main line and, subsequently, the area. The developed optimisation model can be used for designing the periodic‐move sprinkler irrigation system for any given field and farmers conditions according to field shape, topography of the land and availability of sprinkler components, pipe sizes and pumps.
Normalized mutual information of fNIRS signals as a measure for accessing typical and atypical brain activity
Authors: Sun Huiwen , Lin Fang , Wu Xiaoyin , Zhang Tingzhen , Li Jun
Published: February 2023

Normalized mutual information (NMI) can be used to detect statistical correlations between time series. We showed possibility of using NMI to quantify synchronicity of information transmission in different brain regions, thus to characterize functional connections, and ultimately analyze differences in physiological states of brain. Resting‐state brain signals were recorded from bilateral temporal lobes by functional near‐infrared spectroscopy (fNIRS) in 19 young healthy (YH) adults, 25 children with autism spectrum disorder (ASD), and 22 children with typical development (TD). Using NMI of the fNIRS signals, common information volume was assessed for each of three groups. Results showed that mutual information of children with ASD was significantly smaller than that of TD children, while mutual information of YH adults was slightly larger than that of TD children. This study may suggest that NMI could be a measure for assessing brain activity with different development states.
How cation nature controls the bandgap and bulk Rashba splitting of halide perovskites
Authors: de Araujo Luis Octavio , Rêgo Celso R. C. , Wenzel W. , Silveira Danilo N. , Piotrowski Maurício J. , Sabino Fernando P. , Pramudya Yohanes , Guedes‐Sobrinho Diego
Published: February 2023

Because of instability issues presented by metal halide perovskites based on methylammonium (MA), its replacement to has emerged as an alternative to improve the materials' durability. However, the impact of this replacement on electronic properties, especially gap energy and bulk Rashba splitting remains unclear since electrostatic interactions from organic cations can play a crucial role. Through first‐principles calculations, we investigated how organic/inorganic cations impact the electronic properties of and perovskites. Although at high temperatures the organic cation can assume spherical‐like configurations due to its rotation into the cages, our results provide a complete electronic mechanism to show, from a chemical perspective based on ab initio calculations at , how the dipoles suppression can reduce the gap energy by promoting a degeneracy breaking in the electronic states from the framework, while the dipole moment reinforcement is crucial to align theory experiment, increasing the bulk Rashba splitting through higher off‐centering motifs. The lack of permanent dipole moment in results in polymorphs with a pronounced on‐centering‐like feature, which causes suppression in their respective bulk Rashba effect.
The effect of pre‐pyrolysis chemical treatment of waste tyre rubber crumbs: comparison between pre‐treated and conventional waste tyre‐derived oil
Authors: Tsipa Phuti Cedrick , Phiri Mapoloko Mpho , Iwarere Samuel Ayodele , Mkhize Ntandoyenkosi Malusi , Phiri Mohau Justice , Hlangothi Shanganyane Percy
Published: February 2023

BACKGROUND

Pyrolysis process is one of the most effective recycling methods due to its ability to recover products like gas, oil and char with oil being the major/important product. The shortcomings of waste tyre‐derived oil from the conventional pyrolysis process are that the oil contains high amounts of sulfur and polycyclic aromatic hydrocarbons (PAHs) and has a pungent smell, which makes it difficult to utilize further. The aim of this study is to investigate the effect of chemical pre‐treated waste tyre rubber crumb‐derived oil versus conventional waste tyre oil. The instrumentation utilized in this study was to solely investigate the shortcomings of waste tyre pyrolysis (high sulfur and PAH content and also high temperature required for waste tyre pyrolysis).

RESULTS

The results showed a reduction in amounts of both sulfur and PAHs in treated waste tyre‐derived oil by about 83% and 77% respectively. Also, there was a reduction in initial pyrolysis temperature for the treated waste tyre crumb as compared to untreated waste tyre crumb: a temperature range of 96–115 °C for treated waste tyre crumbs as compared to 300–400 °C for untreated waste tyre crumbs.

CONCLUSIONS

The success of this study means the production of quality oil at a low temperature with lower amounts of PAHs and sulfur and less odour, plus the possibilities of it being used as a petroleum fuel or for extraction of important compounds like benzene, toluene, xylene, limonene and C12–C20 acids. © 2023 The Authors. Journal of Chemical Technology and Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry (SCI).
Improved protocol for the radiosynthesis of [18F]FTC‐146: A potent and selective sigma‐1 receptor radioligand
Authors: Sadeghzadeh Masoud , Wenzel Barbara , Nikodemus Julia , Florea Alexandru , Hertel Fabian , Kopka Klaus , Vogg Andreas T. J. , Kiessling Fabian , Mottaghy Felix M.
Published: February 2023

[18F]FTC‐146 was introduced as a very potent and selective sigma‐1 receptor radioligand, which has shown promising application as an imaging agent for neuropathic pain with positron emission tomography. In line with a multi‐laboratory project on animal welfare, we chose this radioligand to investigate its potential for detecting neuropathic pain and tissue damage in tumor‐bearing animals. However, the radiochemical yield (RCY) of around 4–7% was not satisfactory to us, and efforts were made to improve it. Herein, we describe an improved approach for the radiosynthesis of [18F]FTC‐146 resulting in a RCY, which is sevenfold higher than that previously reported. A tosylate precursor was synthesized and radio‐fluorination experiments were performed via aliphatic nucleophilic substitution reactions using either K[18F]F‐Kryptofix®222 (K2.2.2)‐carbonate system or tetra‐n‐butylammonium [18F]fluoride ([18F]TBAF). Several parameters affecting the radiolabeling reaction such as solvent, 18F‐fluorination agent with the corresponding amount of base, labeling time, and temperature were investigated. Best labeling reaction conditions were found to be [18F]TBAF and acetonitrile as solvent at 100°C. The new protocol was then translated to an automated procedure using a FX2 N synthesis module. Finally, the radiotracer reproducibly obtained with RCYs of 41.7 ± 4.4% in high radiochemical purity (>98%) and molar activities up to 171 GBq/μmol.
Formation of a fringe: A look inside baleen morphology using a multimodal visual approach
Authors: Vandenberg Megan L. , Cohen Karly E. , Rubin Robert D. , Goldbogen Jeremy A. , Summers Adam P. , Paig‐Tran E. W. Misty , Kahane‐Rapport Shirel R.
Published: February 2023

Filter‐feeding has been present for hundreds of millions of years, independently evolving in aquatic vertebrates' numerous times. Mysticete whales are a group of gigantic, marine filter‐feeders that are defined by their fringed baleen and are divided into two groups: balaenids and rorquals. Recent studies have shown that balaenids likely feed using a self‐cleaning, cross‐flow filtration mechanism where food particles are collected and then swept to the esophagus for swallowing. However, it is unclear how filtering is achieved in the rorquals (Balaenopteridae). Lunging rorqual whales engulf enormous masses of both prey and water; the prey is then separated from the water through baleen plates lining the length of their upper jaw and positioned perpendicular to flow. Rorqual baleen is composed of both major (larger) and minor (smaller) keratin plates containing embedded fringe that extends into the whale's mouth, forming a filtering fringe. We used a multimodal approach, including microcomputed tomography (µCT) and scanning electron microscopy (SEM), to visualize and describe the variability in baleen anatomy across five species of rorqual whales, spanning two orders of magnitude in body length. For most morphological measurements, larger whales exhibited hypoallometry relative to body length. µCT and SEM revealed that the major and minor plates break away from the mineralized fringes at variable distances from the gums. We proposed a model for estimating the effective pore size to determine whether flow scales with body length or prey size across species. We found that pore size is likely not a proxy for prey size but instead, may reflect changes in resistance through the filter that affect fluid flow.
Comparison of core‐shell versus fully porous particle packings for chiral liquid chromatography productivity
Authors: Lee Jauh Tzuoh , Berthod Alain , Armstrong Daniel W.
Published: February 2023

A loading and productivity study was done using three racemates on vancomycin and teicoplanin‐bonded chiral stationary phases of different particle formats. Two columns were packed with 2.7 μm superficially porous particles and two columns were packed with identically bonded 5 μm fully porous particles. The last two columns were packed with specially synthesized 4.5 μm vancomycin and teicoplanin superficially porous particles. The loading of different chiral compounds showed that the columns filled with 2.7‐μm chiral stationary phases were inappropriate for preparative separations due to their very low permeability which precluded high flow rates. However, columns containing 4.5 μm superficially porous (core‐shell) particles were as effective for small‐scale preparative chiral separations as columns filled with classical 5 μm fully porous particles. Comparing the 4.5 μm superficially porous particles and 5 μm fully porous particles teicoplanin columns, the observed respective productivities of 270 and 265 mg/g chiral phase/h for 5‐methyl‐5‐phenyl hydantoin enantiomers were obtained. Particular attention was given to the peculiar case of the mianserin enantiomeric separation on vancomycin columns that gave observed productivities of 200 and 205 mg/g chiral phase/h on the 4.5 μm superficially porous particles and 5 μm fully porous particles, respectively.
Changes in serum basic fibroblast growth factor concentration following intracordal injection
Authors: Hasegawa Tomohiro , Komazawa Daigo , Konomi Ujimoto , Hirosaki Mayu , Watanabe Yuusuke
Published: February 2023

Objective

Although many studies have reported improvements in voice outcomes with intracordal trafermin injection, there is a lack of data documenting its changes in serum basic fibroblast growth factor (bFGF) blood concentration. This study examined whether serum bFGF concentrations change after intracordal trafermin injection.

Methods

This retrospective study was conducted at Tokyo Voice Center. We investigated serum bFGF concentrations before and after injection in 40 patients who underwent intracordal trafermin injection. There were 26 males and 14 females, with an age ranging from 13 to 88 years (average 53.25 years). They were diagnosed with paralysis (15 patients), atrophy (15 patients), sulcus (8 patients), and others (2 patients: scar and functional), presenting with severe hoarseness that interfered with daily life.

Results

The mean pre‐ and post‐injective serum bFGF concentration of the 40 patients was 6.689 and 4.658 pg/mL, respectively. The difference in mean serum bFGF concentration between pre‐ and post‐injective was −2.031 pg/mL. The Pearson correlation coefficient was calculated to evaluate the correlation between dosage of trafermin and post‐injective serum bFGF concentration, and a moderate correlation was found at r = 0.52. Generalized linear model regression analysis was performed for the purpose of adjusting for confounding among variables. The only variable that showed a statistically predominant association with post‐injective serum bFGF concentrations was the dosage of trafermin, with an estimated regression coefficient of 0.048.

Conclusion

In this study, the dosage of trafermin we injected and post‐injective serum bFGF concentrations were dose‐dependent but the amount of changes in the serum bFGF concentration was negligible within the physiological range. Therefore, as with subcutaneous and wound administration, intracordal trafermin injections may be safe.

Level of Evidence

Level IV.
Early Stage UV‐B Induced Molecular Modifications of Human Eye Lens γD‐Crystallin
Authors: Weininger Susanne , Neudorf Malte , Gröger Stefan , Plato Eric , Broneske Robert , Saalwächter Kay , Weininger Ulrich , Balbach Jochen
Published: February 2023

In the human eye lenses, the crystallin proteins facilitate transparency, light refraction, as well as UV light protection. A deregulated balanced interplay between α‐, β‐, and γ‐crystallin can cause cataract. γD‐crystallin (hγD) is involved in the energy dissipation of absorbed UV light by energy transfer between aromatic side chains. Early UV‐B induced damage of hγD with molecular resolution is studied by solution NMR and fluorescence spectroscopy. hγD modifications are restricted to Tyr 17 and Tyr 29 in the N‐terminal domain, where a local unfolding of the hydrophobic core is observed. None of the tryptophan residues assisting fluorescence energy transfer is modified and hγD is remained soluble over month. Investigating isotope‐labeled hγD surrounded by eye lens extracts from cataract patients reveals very week interactions of solvent‐exposed side chains in the C‐terminal hγD domain and some remaining photoprotective properties of the extracts. Hereditary E107A hγD found in the eye lens core of infants developing cataract shows under the here used conditions a thermodynamic stability comparable to the wild type but an increased sensitivity toward UV‐B irradiation.
Topology optimization design of antennas with complex radiation characteristics
Authors: Guo Haochen , Ding Xiao
Published: February 2023

Antennas with complex radiation characteristics can enhance the adaptability of radiofrequency systems in complex electromagnetic environments. However, The realization of complex targets is extremely challenging for conventional antenna design methods. It is difficult to find a suitable initial topology of the antenna with complex radiation characteristics. Therefore, in this paper, topology optimization is used to explore the initial structure with complex radiation properties. A two‐dimensional lossy thin layer model based on the transitional boundary condition is constructed, and target field functions for complex radiation are proposed. To verify the effectiveness of the algorithm, a high gain antenna with 10.2 dBi is realized, which has the highest aperture efficiency compared with the literature in similar directions. Then, for more complex targets, the radiation patterns of arbitrary direction null, arbitrary direction beam, and equal‐amplitude dual beam are realized, respectively. The topology optimization algorithm provides a new approach for the design of complex multitarget antennas.
Synthesis of the 1,5‐Benzothiazepane Scaffold – Established Methods and New Developments
Authors: Ronse Ulrike , Magdalenić Katarina , Van Camp John , D'hooghe Matthias
Published: February 2023

The 1,5‐benzothiazepane structure is an important heterocyclic moiety present in a variety of commercial drugs and pharmaceuticals. This privileged scaffold exhibits a diversity of biological activities, including antimicrobial, antibacterial, anti‐epileptic, anti‐HIV, antidepressant, antithrombotic and anticancer properties. Its important pharmacological potential renders research into the development of new and efficient synthetic methods of high relevance. In the first part of this review, an overview of different synthetic approaches toward 1,5‐benzothiazepane and its derivatives is provided, ranging from established protocols to recent (enantioselective) methods that promote sustainability. In the second part, several structural characteristics influencing biological activity are briefly explored, providing a few insights into the structure‐activity relationships of these compounds.
Comparison of toughening effects of several common toughening agents and polycarbonate‐polydimethylsiloxane block copolymer on polyvinyl chloride
Authors: Wang Xiaofei , Zhang Jun , Chen Hao
Published: February 2023

In this work, different toughening agents such as chlorinated polyethylene (CPE), acrylonitrile–styrene‐acrylate (ASA) terpolymer, acrylic modifier (ACR, the main component is poly(methyl methacrylate‐butyl acrylate)) and polycarbonate‐polydimethylsiloxane block copolymer (PC‐b‐PDMS) were used to toughen polyvinyl chloride (PVC). Different content toughening agents (10 and 20 phr) were added into PVC and their properties were tested. The results exhibited that ACR, ASA, and PC‐b‐PDMS‐40 (40% PDMS content) had high impact strength (more than 100 kJ m−2) at room temperature. With the decrease of temperature, the toughening effect of ACR and ASA dropped significantly (7.30 and 3.69 kJ m−2 at −30°C respectively), while PC‐b‐PDMS‐40 still had certain toughening effect (19.66 kJ m−2 at −30°C). The tensile and flexural strength of blends decreased with the addition of toughening agents, while due to strong interactions between PC and PVC, elongation at break of PVC/PC‐b‐PDMS also have obvious drop. Heat distortion temperature results showed that the heat resistance of PVC was not reduced by toughening agents except CPE. The DMTA curves of blends revealed the reason why PVC/PC‐b‐PDMS‐40 had good toughness at low temperature that the glass transition temperature of PDMS is very low (−123°C), which makes it flexible at low temperature.
Effect of silicon dioxide and organized montmorillonite on the crystalline morphology and dielectric properties of polypropylene‐based composites
Authors: Gao Junguo , Ju Huicheng , Yao Ziheng , Zhang Guangwei , Liu Yanli , Niu Jicheng
Published: February 2023

Polypropylene (PP), a thermoplastic material that can be recycled by melting, is viewed as a potential alternative to cross‐linked polyethylene for insulation. In this work, PP‐based composites were fabricated with surface‐modified silicon dioxide (SiO2), organized montmorillonite (OMMT), and polyolefin elastomer (POE) as fillers via a two‐step melt blending method. The dispersion states of SiO2 nanoparticles, OMMT, and POE in PP and their effects on PP crystallization were investigated. Moreover, the elongation at break, yield stress, energy storage modulus, damping loss factor, broadband dielectric spectrum, bulk resistivity, and alternating current (AC) breakdown strength of the specimens were tested. POE significantly increased the composite toughness, whereas the AC breakdown field strength and volume resistivity of POE/PP were lower. The homogeneously dispersed SiO2 and OMMT in the matrix acted as heterogeneous nucleation sites and reduced the grain size. To varying degrees, they effectively improved the dielectric properties, volume resistivity, and breakdown field strength of the composites. Hence, the composites simultaneously had excellent mechanical and dielectric properties. The volume resistivity of SiO2‐OMMT‐POE/PP with higher crystallinity was 15.4 times higher than that of POE/PP, and the breakdown field strength increased by 16.4%.
Effects of proton pump inhibitor on gastroesophageal varices in patients with cirrhosis: A randomized controlled trial from China
Authors: Chen Xiaoning , Zhou Tao , Zhou Ting , Li Yueyue , Sun Xin , Cheng Baoquan , Zhong Ning , Lu Xuefeng , Gao Yanjing
Published: February 2023

Aims

Proton pump inhibitors (PPI) are widely used for gastroesophageal varices in patients with cirrhosis after endoscopic therapy, although the effect of PPI on these patients remains controversial. This study aimed to evaluate the effect of PPI on gastroesophageal varices in patients with cirrhosis after endoscopic therapy, including variceal bleeding and adverse events.

Methods

Cirrhotic patients with endoscopically confirmed gastroesophageal varices were enrolled in this study between May 2017 and June 2019. Eligible patients were randomized into two groups: one group received PPI for 14 days and the other group did not receive PPI treatment (n = 53 in each group). All patients were followed for 8 weeks.

Results

During the follow‐up period, three patients (5.66%) in the PPI group experienced variceal bleeding on days 9, 16, and 25 after endoscopic therapy, including two patients with acute bleeding and one with primary prophylaxis. In the non‐PPI group, three patients (5.66%) experienced variceal bleeding on days 7, 42, and 56 after endoscopic therapy, including one patient with acute bleeding and two with secondary prophylaxis (p = 0.990). The incidence of adverse events was similar between the two groups (37.74% vs. 28.30%, p = 0.30).

Conclusions

PPI did not appear to reduce variceal bleeding and adverse events in patients with cirrhosis after endoscopic therapy.
Sustainable development through green innovation and resource allocation in cities: Evidence from machine learning
Authors: Mao Jun , Xie Jiahao , Hu Zunguo , Deng Lijie , Wu Haitao , Hao Yu
Published: February 2023

China has promoted innovation‐driven and green development to unprecedented strategic heights. However, compared to the large and rapid innovation investment, total factor productivity's (TFP) growth rate has shown a downward trend. Consequently, this study assesses the inefficiency caused by resource mismatch and discusses the impact of green innovation activities on green total factor productivity (GTFP). We use a causal forest‐based machine learning method to solve the endogenous problem. The empirically analyzes the observation samples of 272 prefecture‐level cities in China from 2008 to 2018 and obtains the asymptotic normality estimation on the average treatment effect (ATE). Simultaneously, clustering causal forest and ridge expressions, discusses the robustness of related problems. According to the results, (1) the effect of China's green innovation on GTFP is negative for a short time and positive for a long time; (2) the impact of green innovation activities on GTFP is subject to capital mismatch, while the statistical law of the impact of labor mismatch is not obvious but the adverse impact of resource mismatch is gradually improving; and (3), Green innovation has significantly improved China's GTFP, but it did not lead to ideal Growth rate of GTC.
Exciton recombination in few‐layer MoS2 nanosheets: Role of free carriers and defects
Authors: Taank Pravrati , Karmakar Riyanka , Adarsh K. V.
Published: February 2023

A current obstacle to the development of extremely flexible and high‐performance optoelectronic devices using transition metal dichalcogenide nanosheets is the incomplete understanding of the exciton and free carrier recombination in the presence of defects. Here, taking liquid‐phase exfoliated few‐layer MoS2 nanosheets as a model system, we demonstrate the exciton and free carrier recombination mechanism by employing pump energy and fluence‐dependent ultrafast transient absorption spectroscopy. We demonstrate that 3.10 eV pump excitation, much above the lowest energy A exciton of four to six layers of MoS2 nanosheets (~1.84 eV), generates excitons and free carriers. The excitons decay quickly within ~3 ps due to the defect capture via the Shockley–Read–Hall mechanism. In contrast, free carriers show slower recombination (~1000 ps), which is an order of magnitude larger than the exciton recombination time. We verified this idea by exciting the sample with 1.94–2.22 eV pump excitations that predominantly generate excitons decaying within ~3 ps. Our systematic studies in few‐layer MoS2 nanosheets reveal crucial information on the unexplored domain of excitons and free carriers recombination in the presence of defects for several optoelectronic applications.
Designing Low Tortuosity Electrodes through Pattern Optimization for Fast‐Charging
Authors: Wang Ying , Zhang Yuxuan , Cao Daxian , Ji Tongtai , Ren Haoze , Wang Guanyi , Wu Qingliu , Zhu Hongli
Published: February 2023

The development of fast‐charging technologies is crucial for expediting the progress and promotion of electric vehicles. In addition to innovative material exploration, reduction in the tortuosity of electrodes is a favored strategy to enhance the fast‐charging capability of lithium‐ion batteries by optimizing the ion‐transfer kinetics. To realize the industrialization of low‐tortuosity electrodes, a facile, cost‐effective, highly controlled, and high‐output continuous additive manufacturing roll‐to‐roll screen printing technology is proposed to render customized vertical channels within electrodes. Extremely precise vertical channels are fabricated by applying the as‐developed inks, using LiNi0.6Mn0.2Co0.2O2 as the cathode material. Additionally, the relationship between the electrochemical properties and architecture of the channels, including the pattern, channel diameter, and edge distance between channels, is revealed. The optimized screen‐printed electrode exhibited a seven‐fold higher charge capacity (72 mAh g−1) at a current rate of 6 C and superior stability compared with that of the conventional bar‐coated electrode (10 mAh g−1, 6 C) at a mass loading of 10 mg cm−2. This roll‐to‐roll additive manufacturing can potentially be applied to various active materials printing to reduce electrode tortuosity and enable fast charging in battery manufacturing.
Drug stability in forensic toxicology
Authors: Nisbet Lorna A. , DiEmma Gabrielle E. , Scott Karen S.
Published: February 2023

Knowledge of the stability of analytes in solvents and biological matrices is of high importance in the field of forensic toxicology. This is particularly true where quantitative analysis is undertaken; degradation of analytes will result in under‐estimation of concentrations, whereas the production of analytes/metabolites will lead to over‐estimation. Although stability is included as part of method validation, this typically focuses on processed sample stability, and the impact of freeze/thaw cycles upon analytes. Although beneficial for method evaluation, this does not assist laboratory analysts with the short‐ and long‐term storage of samples prior to this step and does not consider the impact the biological matrix may have on the degradation or production of the analyte in question. The timeframe for these studies is also relatively short (typically 72 h), which does not cover the time frame between sample receivership and analysis for many forensic cases. This review collects previously published work on long‐term stability studies, grouping compounds into their associated drug classes and matrices. Research shows that the majority of compounds are more stable at lower storage temperatures, and that analysis should be completed as quickly as possible. It is advised that analyte stability be considered prior to any interpretation of concentrations in a forensic setting.

This article is categorized under:

Toxicology > Analytical

Toxicology > Drug Analysis

Toxicology > Drug Stability