bluuebunny/crossref_metadata_2025 huggingface dataset:
An Overview of Marketed Nucleoside and Nucleotide Analogs
Authors: De Jonghe Steven , Herdewijn Piet
Published: March 2022

Nucleos(t)ide chemistry has been the subject of intense research, mainly because of the promising antiviral and antitumoral activity associated with this compound class. Numerous analogs have been synthesized over the past decades, yielding a number of derivatives that have reached the status of marketed drugs. Herein, an overview of the nucleos(t)ide analogs that have received marketing approval is given. The review is divided into several sections, including antiviral and antitumoral nucleoside analogs as well as nucleoside analogs that have received marketing approval in other therapeutic areas. © 2022 Wiley Periodicals LLC.
Hybrid soft switching DC–DC boost converter
Authors: Yeşilyurt Hüseyin
Published: March 2022

In this study, hybrid soft switching (HSS) DC–DC boost converter is proposed. The proposed converter operates as the conventional discontinuous conduction mode (DCM) pulse‐width modulated (PWM) DC–DC boost converter at light loads. When the output power increases, the snubber cell is activated, and the converter operates as frequency controlled soft switching resonant converter. Thus, higher efficiency is obtained at high power levels. In the proposed converter, the snubber cell works with a simple on–off logic instead of PWM control. Thus, it has a quite simple structure consisting of only a switch and a snubber capacitor, and does not need an additional PWM control signal. Hence, the proposed converter has the advantages of conventional DCM PWM converters while operating with higher efficiency at higher power levels. There is no additional voltage stress on any semiconductor power devices. Theoretical analysis is verified with a laboratory application of a DC‐DC boost converter having input voltage of 90 V, output voltage of 400 V and output power of 1 kW.
A novel, simple, and dedicated device for endoscopic mucosal defect closure
Authors: Nose Yohei , Takizawa Kohei , Shiotsuki Kazuo , Yamaguchi Tsuyoshi , Agatsuma Masaomi , Nitta Shun , Yamashita Kotaro , Saito Takuro , Tanaka Koji , Yamamoto Kazuyoshi , Makino Tomoki , Takahashi Tsuyoshi , Kurokawa Yukinori , Eguchi Hidetoshi , Doki Yuichiro , Nakajima Kiyokazu
Published: March 2022

Objectives

Endoscopic submucosal dissection (ESD) has become popular, but complications such as postoperative bleeding remain an issue. Although some methods of closing a mucosal defect with a snare and clips have been reported to be effective and safe, the snare is not a dedicated device, and the procedure is difficult and time‐consuming. We aimed to find an alternative method for defect closure after ESD by developing a dedicated device.

Methods

We have improved five prototypes. The load on the stopper when starting to tighten and loosen a loop and the maximum load on the stopper and the movement distance of the thread when sliding the stopper were measured five times for each prototype. With the 5th prototype, we finalized the design and named it FLEXLOOP. Additionally, the material and shape of the outer tube were improved. Then, the usability of FLEXLOOP was evaluated in pigs. The operation time for closing mucosal defects with the snare or FLEXLOOP was measured five times.

Results

We made FLEXLOOP, which had a lower load when sliding and a higher load when loosening than the snare. The improvement of the outer tube significantly reduced the load on the sheath when sliding it. We confirmed the feasibility of mucosal defect closure with FLEXLOOP in pigs. The median operation time was 563 s (range 340–679 s) with the snare and 355 s (range 303–455 s) with FLEXLOOP (p = 0.047).

Conclusions

FLEXLOOP can be a promising option for defect closure after ESD.
Report of a case of cirrhotic portal hypertension with ectopic varices in the bilateral pulmonary hilar
Authors: Zhu Ke , Zhang Wei , Shao Wei , Ding Jing , Ma Chao
Published: March 2022

Here, we report the case of patient cirrhosis with esophageal and gastric fundal varices who developed rare ectopic varices in the bilateral pulmonary hilar after repeated endoscopic treatments (tissue adhesive for gastric fundal varices + esophageal variceal ligation + esophageal variceal sclerotherapy) accompanied by serious shortness of breath. After transjugular intrahepatic portosystemic shunt + gastric coronary vein embolization, the shortness of breath was relieved, and the portography review indicated that the ectopic varices in the pulmonary hilar were significantly improved.
Recent advances in solid–liquid–gas three‐phase interfaces in electrocatalysis for energy conversion and storage
Authors: Jiang Haosong , Luo Ruihao , Li Yimin , Chen Wei
Published: March 2022

The acceleration of energy exhaustion and environmental pollution calls for the development of electrocatalytic conversion and storage technologies for the production and utilization of green energy. However, these technologies have encountered significant challenges in terms of poor selectivity, high overpotential, low efficiency, and sluggish kinetics of the electrocatalytic reactions, which involve solid–liquid–gas three‐phase interfaces (SLG‐TPIs). In this review, we focus on discussing recent progress on the development of SLG‐TPIs for electrocatalytic reactions, such as hydrogen evolution reaction (HER), oxygen evolution and reduction reactions (OER/ORR), and carbon dioxide reduction reaction (CO2RR), as well as their applications in water splitting, fuel cells, and metal‐air batteries. In addition, the working mechanism of TPIs is described and revealed by advanced characterization tools. The challenges and future opportunities of TPIs for electrocatalysis are also proposed in this review.

image
Social Determinants of Health Factors for Gene–Environment COVID‐19 Research: Challenges and Opportunities
Authors: Phuong Jimmy , Riches Naomi O. , Madlock‐Brown Charisse , Duran Deborah , Calzoni Luca , Espinoza Juan C. , Datta Gora , Kavuluru Ramakanth , Weiskopf Nicole G. , Ward‐Caviness Cavin K. , Lin Asiyah Yu
Published: March 2022

The characteristics of a person's health status are often guided by how they live, grow, learn, their genetics, as well as their access to health care. Yet, all too often, studies examining the relationship between social determinants of health (behavioral, sociocultural, and physical environmental factors), the role of demographics, and health outcomes poorly represent these relationships, leading to misinterpretations, limited study reproducibility, and datasets with limited representativeness and secondary research use capacity. This is a profound hurdle in what questions can or cannot be rigorously studied about COVID‐19. In practice, gene–environment interactions studies have paved the way for including these factors into research. Similarly, our understanding of social determinants of health continues to expand with diverse data collection modalities as health systems, patients, and community health engagement aim to fill the knowledge gaps toward promoting health and wellness. Here, a conceptual framework is proposed, adapted from the population health framework, socioecological model, and causal modeling in gene–environment interaction studies to integrate the core constructs from each domain with practical considerations needed for multidisciplinary science.
Hyaluronan as “Agent Smith” in cancer extracellular matrix pathobiology: Regulatory roles in immune response, cancer progression and targeting
Authors: Kokoretsis Dimitris , Maniaki Evangelia‐Konstantina , Kyriakopoulou Konstantina , Koutsakis Christos , Piperigkou Zoi , Karamanos Nikos K.
Published: March 2022

Extracellular matrix (ECM) critically regulates cancer cell behavior by governing cell signaling and properties. Hyaluronan (HA) acts as a structural and functional ECM component that mediates critical properties of cancer cells in a molecular size‐dependent manner. HA fragments secreted by cancer‐associated fibroblasts (CAFs) reveal the correlation of HA to CAF‐mediated matrix remodeling, a key step for the initiation of metastasis. The main goal of this article is to highlight the vital functions of HA in cancer cell initiation and progression as well as HA‐mediated paracrine interactions among cancer and stromal cells. Furthermore, the HA implication in mediating immune responses to cancer progression is also discussed. Novel data on the role of HA in the formation of pre‐metastatic niche may contribute towards the improvement of current theranostic approaches that benefit cancer management.
Efficient sterilization system combining flavonoids and hyaluronic acid with metal organic frameworks as carrier
Authors: Yang Jie , Wang Yaling , Gao Yin , Wang Zekun , Yin Chenyang , Ding Xiaoyuan , Yang Endong , Sun Dongdong , Wang Weiyun , Guo Feng
Published: March 2022

Bacterial infections can cause many human diseases, which are closely related to people's health. Nowadays, antibiotics are mainly used to treat bacterial infections, but the widespread use of antibiotics can also lead to bacterial resistance. Therefore, effective treatment of bacterial infections is an urgent problem to be solved. In this article, a multifunctional therapeutic material with antibacterial properties was designed and synthesized. First, the porous media material ZIF‐8 was synthesized, and applied to load hesperidin. When the load is completed, a layer of hyaluronic acid (HA) is uniformly wrapped on surface of the material. Such materials have high stability and high drug‐carrying capacity, and can be slowly released in vivo. The HA coated on surface can also promote penetration of active ingredients into cells and give full play to antibacterial ability. Results of in vitro and in vivo antibacterial tests show that synergy between the materials enhances antibacterial activity which is related to dose. The material achieves high‐efficiency antibacterial effects by increasing the permeability of cell membranes and destroying the integrity of bacteria. At same time, the material does not show obvious side effects. Therefore, the material seems to be a promising antibacterial agent with good biocompatibility and strong antibacterial activity.
E2F4 may be a core transcription factor in the lncRNA‐TF regulatory network in cervical cancer
Authors: Yang Haiyan , Qu Xiaoli , Huang Jiangang , Zhang Fan , Fang Ziyu , Zhao Bin , Wang Yifeng
Published: March 2022

Background

Cervical cancer is the most common gynecological cancer worldwide and is associated with high morbidity and mortality. Despite improvements in therapeutic strategies, the network regulation mechanism remains unclear and the treatment effect is not satisfactory. Therefore, there is a need to continue studying the mechanism of cervical cancer to explore effective gene targets and precise targeted therapy drugs.

Methods

First, three paired tissues (cancer tissues and noncancerous tissues) from patients with cervical squamous cell carcinoma were collected, grouped, and analyzed by microarray. Second, differentially expressed mRNAs (DEMs) and differentially expressed lncRNAs (DELs) (|fold change| ≥ 2 and p < 0.05) between the two groups were screened. For DEMs, functional annotation and pathway analysis were performed using DAVID. Functional prediction of DELs was then performed and their cis‐regulatory and trans‐regulatory networks were explored.

Results

Function prediction of DELs (both up‐regulated and down‐regulated) shows that the highest frequency Cellular Component (CC) item is cytosol, the highest frequency Molecular function (MF) item is mitotic cell cycle and the highest frequency Biological Process (BP) item is protein binding. Through cis‐regulation analysis of DELs, the cis‐regulatory relationship of 96 DELs was predicted. The lncRNA‐trans‐regulation network analysis suggested that E2F4 may be the core transcription factor in the lncRNA‐TF regulatory network in cervical cancer.

Conclusions

The lncRNA‐TF regulatory network plays an important role in the occurrence and progression of cervical cancer, and E2F4 may be a critical transcription factor in the regulatory network.
Paroxysmal nocturnal haemoglobinuria, diagnosis and haematological findings, first report from Iran, model for developing countries
Authors: Jahangirpour Mohammadali , Vahedi Amirali , Baghdadi Hamed , Madani Tahereh , Behvarmanesh Ali , Alidadi Mohammad , Boroojerdi Mohadese Hashem , Mohammaei Saba , Poopak Peyvand , Poopak Amirhossein , Pour Gelareh Khosravi , Poopak Behzad
Published: March 2022

Since paroxysmal nocturnal haemoglobinuria (PNH) was first described in 1881, the diagnosis and follow‐up patients diagnosed with the illness has remained an area of concern, with several different techniques of varying sensitivity having been described in the literature for both the diagnosis and monitoring treatment of the disease. PNH is a rare and life‐threatening disease that manifests symptoms of haemolytic anaemia. Hence, a quick and reliable technique for precise diagnosis would be crucial. PNH patients who have previously been diagnosed with aplastic anaemia or myelodysplastic syndrome carry small PNH clones and for more than a century traditional method with low sensitivity was used for such patients. In 2010, the International Clinical Cytometry Society described a highly sensitive method for detection and quantification of different types of PNH clones using multi‐colour flow cytometry. In this method, a three‐colour flow cytometer is essential to detect PNH affected cells amongst monocytes and granulocytes. This started a new era in the diagnosis of patients who carry small clones of PNH cells. Before this, flow cytometric analysis was used only for detection of PNH cells amongst erythrocytes. By using flow cytometry instruments with more light sources, the sensitivity of detection and quantification of PNH clones would be augmented. However, standardisation and crosstalk compensation would be the most concerning issue. For the first time in Iran, we set up and standardised multi‐colour flow cytometry technique to detect PNH cells in erythrocytes and leukocytes at Payvand medical laboratory.
Trends in cocirculation of oncogenic HPV genotypes in single and multiple infections among the unvaccinated community
Authors: Vazifehdoost Manijheh , Eskandari Fatemeh , Sohrabi Amir
Published: March 2022

Cocirculation of multiple human papillomavirus (HPV) infections with low, probably high, and high‐risk genotypes are to be associated with various grades of infections and cancer progression. The oncogenic high‐risk HPVs are distributed and cocirculated throughout the world. This study was investigated to identify HPV genotypes related to genital disorders in unvaccinated women. The subjects were referred from clinics to a molecular lab for HPV testing in Iran as a low‐coverage vaccinated country. HPVs DNAs of cervical scrapping and genital tissue specimens of 1,133 un‐vaccinated women were genotyped using an in vitro diagnostic line probe (reverse hybridization) assay. In addition, phylogenetic trees were constructed on 100 MY09/MY11 polymerase chain reaction (PCR) amplicons of common genotypes of HPV L1 gene by Sanger sequencing. The mean age of the population study was 32.7 ± 8.0 and the mean age of HPV‐positive cases was 31.6 ± 7.8. HPV DNA was detected in 57.8% (655/1133) of women subjects and 42.2% (478/1133) of cases were undetected. Among 655 HPV‐positive cases, 639 subjects (56.4%) were related to defined genotypes and 16 subjects (1.4%) were untypeable. The highest prevalence rate of HPV genotypes was identified in the 25–34 years. The top 6 dominant HPVs in single and multiple genotypes were HPV6 (284/655 [43.4%]), HPV16 (111/655 [16.9%]), HPV31 (72/655 [11%]), HPV53 (67/655 [10.2%]), HPV11 (62/655 [9.5%]), and HPV52 (62/655 [9.5%]). Moreover, single, multiple and untypeable HPV genotypes were diagnosed as follows: 1 type (318/655 [48.5%]), 2 types (162/655 [24.8%]), 3 types (83/655 [12.7%]), 4 types (42/655 [6.5%]), more than 5 types (34/655 [5.3%]), and 1.4% un‐typeable subjects. The sequenced partial L1 gene of HPV genotypes (GenBank databases under the accession numbers: MH253467‐MH253566) confirmed and determined the cocirculated HPV genotypes' origins and addressed helpful insights into the future viral epidemiology investigations. Multiple HPV infections and cocirculation of various oncogenic HPV genotypes among the normal population (women and men) with asymptomatic forms are still challenging in unvaccinated communities. The preventive and organized surveillance programs for HPV screening are needed to be considered and compiled by health policy makers of low or unvaccinated countries.
On the association between poly(vinyl alcohol) and sodium dodecyl sulfate and its effect on liquid–liquid interfacial tension: A mathematical model
Authors: Ramirez Jorge C. , Hernández‐Belmares Perla J. , Herrera‐Ordonez Jorge
Published: March 2022

Association between poly(vinyl alcohol‐co‐vinyl acetate) copolymer (PVA) and sodium dodecyl sulfate (SDS) was studied experimentally and theoretically. It was found that, for the ethyl acetate‐aqueous phase interface in which PVA was previously adsorbed, the interfacial tension (γ) increases abruptly to a maximum and then exhibits a relatively mild decay with the addition of SDS to the aqueous phase. The theoretical results indicate that vinyl acetate (VAc) segments determine γ. However, for relatively low concentrations of SDS (CSDS), this latter plays a major role because through its association with the VAc segments it modulates the extent to which PVA is adsorbed at the interface, indirectly determining the value of γ. As CSDS approaches to the CMC value for SDS, its influence on γ decreases because SDS tends to self‐assembly rather than associates with VAc. These model predictions are consistent with experimental findings reported in the literature.
“Will it work for me?” Developing patient‐friendly graphical displays of posttraumatic stress disorder treatment effectiveness
Authors: Hamblen Jessica L. , Grubbs Kathleen M. , Cole Bernard , Schnurr Paula P. , Harik Juliette M.
Published: March 2022

The goal of this study was to create simple visual displays to help patients understand the benefits of evidence‐based treatment for posttraumatic stress disorder (PTSD). We reviewed randomized trials of the most effective individual, trauma‐focused psychotherapies and first‐line antidepressants for adults with PTSD. The analytic sample included 65 treatment arms from 41 trials. We used binomial logistic regression to estimate the proportion of participants who lost their PTSD diagnosis at posttreatment and created a sample icon array to display these estimates. We provide a range of estimates (0–100) based on varying the percentage of the sample with a military affiliation. The percentage of participants who no longer met the diagnostic criteria for PTSD among civilian populations was 64.3% for trauma‐focused treatment, 56.9% for SSRI/SNRI, and 16.7% for waitlist/minimal attention. For military populations, the proportions of participants who no longer met the diagnostic criteria were 44.2%, 36.7%, and 8.1%, respectively. We present icon arrays for 0%, 7%, 50%, and 100% military affiliation displaying 100 icons, a portion of which were shaded to indicate the number of participants that no longer met the PTSD criteria following treatment. After evidence‐based treatment, between one third and two thirds of participants no longer met the PTSD criteria. Providers can use the icon array developed in this study with patients to facilitate communication regarding PTSD treatment effectiveness.
Analysis of a finite difference method based on L1 discretization for solving multi‐term fractional differential equation involving weak singularity
Authors: Santra Sudarshan , Mohapatra Jugal
Published: March 2022

In this article, we consider a multi‐term fractional initial value problem which has a weak singularity at the initial time
. The fractional derivatives are defined in Caputo sense. Due to such singular behavior, an initial layer occurs near
which is sharper for small values of γ1 where γ1 is the highest order among all fractional differential operators. In addition, the analytical properties of the solution are provided. The classical L1 scheme is introduced on a uniform mesh to approximate the fractional derivatives. The error analysis is carried out, and it is shown that the numerical solution converges to the exact solution. Further analysis proves that the scheme is of order
over the entire region, but it is of order O(τ) on any subdomain away from the origin. τ denotes the mesh parameter. To show the efficiency of the proposed scheme, this method is tested on several model problems, and the results are in agreement with the theoretical findings.
Global and local asymptotic stability of an epidemic reaction‐diffusion model with a nonlinear incidence
Authors: Djebara Lamia , Douaifia Redouane , Abdelmalek Salem , Bendoukha Samir
Published: March 2022

The aim of this paper is to study the dynamics of a reaction‐diffusion SI (susceptible‐infectious) epidemic model with a nonlinear incidence rate describing the transmission of a communicable disease between individuals. We prove that the proposed model has two steady states under one condition. By analyzing the eigenvalues and using the linearization method and an appropriately constructed Lyapunov functional, we establish the local and global asymptotic stability of the non‐negative constant steady states subject to the basic reproduction number being greater than unity and of the disease‐free equilibrium subject to the basic reproduction number being smaller than or equal to unity in ODE case. By applying an appropriately constructed Lyapunov functional, we identify the condition of the global stability in the PDE case. Finally, we present some numerical examples illustrating and confirming the analytical results obtained throughout the paper.
Decay properties for inhomogeneous heat‐conducting magnetohydrodynamic equations
Authors: Han Pigong , Lei Keke , Liu Chenggang , Wang Xuewen
Published: March 2022

In this paper, we study the temporal decay of weak solutions to the inhomogeneous heat‐conducting magnetohydrodynamic equations. Under appropriate assumptions for external forces, some decay properties for the inhomogeneous heat‐conducting systems are obtained. The decay rates coincide with the optimal ones of the classical homogeneous incompressible Navier‐Stokes equations.
Enhanced detection of paramagnetic fluorine‐19 magnetic resonance imaging agents using zero echo time sequence and compressed sensing
Authors: Chen Jiawen , Pal Piya , Ahrens Eric T.
Published: March 2022

Fluorine‐19 (19F) magnetic resonance imaging (MRI) is an emerging technique offering specific detection of labeled cells in vivo. Lengthy acquisition times and modest signal‐to‐noise ratio (SNR) makes three‐dimensional spin‐density–weighted 19F imaging challenging. Recent advances in tracer paramagnetic metallo‐perfluorocarbon (MPFC) nanoemulsion probes have shown multifold SNR improvements due to an accelerated 19F T1 relaxation rate and a commensurate gain in imaging speed and averages. However, 19F T2‐reduction and increased linewidth limit the amount of metal additive in MPFC probes, thus constraining the ultimate SNR. To overcome these barriers, we describe a compressed sampling (CS) scheme, implemented using a “zero” echo time (ZTE) sequence, with data reconstructed via a sparsity‐promoting algorithm. Our CS‐ZTE scheme acquires k‐space data using an undersampled spherical radial pattern and signal averaging. Image reconstruction employs off‐the‐shelf sparse solvers to solve a joint total variation and
‐norm regularized least square problem. To evaluate CS‐ZTE, we performed simulations and acquired 19F MRI data at 11.7 T in phantoms and mice receiving MPFC‐labeled dendritic cells. For MPFC‐labeled cells in vivo, we show SNR gains of ~6.3 × with 8‐fold undersampling. We show that this enhancement is due to three mechanisms including undersampling and commensurate increase in signal averaging in a fixed scan time, denoising attributes from the CS algorithm, and paramagnetic reduction of T1. Importantly, 19F image intensity analyses yield accurate estimates of absolute quantification of 19F spins. Overall, the CS‐ZTE method using MPFC probes achieves ultrafast imaging, a substantial boost in detection sensitivity, accurate 19F spin quantification, and minimal image artifacts.
Bone spearheads from the Late Prehispanic Period of Sierras of Cordoba (Argentina)
Authors: Medina Matías E. , Sario Gisela , Pastor Sebastián
Published: March 2022

The archaeological record of the Late Prehispanic Period of Sierras of Córdoba, Argentina (~1220–330 cal BP) has revealed a rich and highly developed bone industry. The worked bones are purported to include various types of hunting or warfare weapons such as arrowheads, knives and daggers, or bleeders. However, most of the latter two tools can now be interpreted as spear or spear‐thrower dart heads based on ethnographic and macro‐wear studies. Thus, the aim of this article is to present the techno‐typological and functional analysis carried out on the bone spearheads collected at the San Roque archaeological locality (Villa Carlos Paz, Argentina). Spearheads are defined as massive and strong pointed tools that are suitable for hafting to a shaft about 15 mm or more in diameter, which corresponds to ethnographic spears or darts. The tools were assigned to the Late Prehispanic Period based on their similarity with those recovered in neighboring sites and regions during the last 1,500 years. The study supports the contention that Late Prehispanic people developed a variable and highly sophisticated set of weapons suitable for taking any animal resource when encountered, minimizing the cost of failure in the capture of the prey they depended on. However, warfare and the use of spears in raids against other groups need to be taken into account because evidence of physical interpersonal violence increases in the Late Prehispanic Period. Finally, it is proposed that museum collections can provide valuable data for archaeologists, mostly when artifacts with low frequency in modern excavations are the focus of the analysis.
Designing a novel polythioether/multiwall carbon nanotube nanocomposites: A complete overview of mechanical, thermal, and morphological properties
Authors: Haramshahi Seyyed Ali , Moini Jazani Omid , Sohrabian Majid
Published: March 2022

Polythioether is an elastomer with proper thermal resistance and elongation at break, which can be used in various high‐temperature and high‐pressure sealing applications. This research is aimed to determine the suitable thiol/vinyl ratio and the branching agent content to synthesize a novel polythioether and the polythioether/multiwall carbon nanotube (MWCNT) composite using two monomers, including dimercapto dioxaoctane (DMDO) and triethylene glycol divinylether. For each synthesis process, the gel permeation chromatography (GPC) was used to measure the molecular weight and the polydispersity index of the polymer chains. Fourier transforms infrared spectroscopy and Nuclear Magnetic Resonance were used to study the bond formation, while the glass transition of the polymer was evaluated by differential scanning calorimetry. Tensile and lap adhesion tests were also used to assess the mechanical properties of the samples. Field emission scanning electron microscopy was utilized to observe the dispersion of nanoparticles in polythioether/MWCNT nanocomposite. GPC results showed that the thiol/vinyl ratio of 0.5 and branching agent molar ratio of 0.2 (relative to vinyl monomer) led to the most suitable average molecular weight (2022 g/mol) which had the highest mechanical properties. The nanocomposite containing 1 wt% MWCNT, showed the highest tensile strength and elongation at break up to 2.12 MPa and 303%, respectively. A considerable increase of 30°C is obtained in maximum degradation temperature of the produced nanocomposite compared to neat polythioether.
Some open challenges in polymer physics*
Authors: McKenna Gregory B. , Chen Dongjie , Mangalara Satish Chandra Hari , Kong Dejie , Banik Sourya
Published: March 2022

Three subjects in polymer and soft matter physics are outlined in the present article. The first relates to concepts of an ideal glass transition. We describe work on ultra‐stable glass, either a 20‐million‐year‐old amber or a vapor deposited amorphous fluoropolymer, which examines the temperature dependence of the dynamics in a window between a low fictive temperature and the glass transition temperature. From this “finesse” of the problem of the geological time scales in sub‐glass temperature systems strong evidence that the divergence of the relaxation times at finite temperature from WLF‐types of extrapolation is not correct. The second topic is polymer nonlinear viscoelasticity as it relates to dynamic heterogeneity. We show results from mechanical hole burning experiments that suggest that dynamic heterogeneity arises from the nature of specific relaxation mechanisms rather than heterogeneous changes in, for example, the fictive temperature. Included is a discussion of large amplitude oscillatory shear testing and how it relates to characterization of nonlinear viscoelastic materials. The last topic addressed is the rheology of circular macromolecules. Here, we take a historical perspective and describe important new results from several laboratories that seem inconsistent. New works from our own studies on circular DNA are also discussed.
Direct dynamics simulation of the thermal O(3P) + dimethylamine reaction in the triplet surface. I. Rate constant and product branching
Authors: Chakraborty Debdutta , Hase William L.
Published: March 2022

In order to provide atomistic details for the mechanism of the collisional dynamics of O(3P) and dimethylamine (DMA) in the triplet electronic surface, direct dynamics simulations are reported herein. The simulations are performed at the U‐HSE06/aug‐cc‐pVDZ level of theory. The results are reported for the relative collision energy of 7.8 kcal/mol. For the vibrational and rotational excitations, following temperature regimes have been considered: 200 and 10 K, respectively. Simulations reveal that the reaction can lead to two product channels in the considered energy regime: (1) 2OH + 2CH3NHCH2 and (2) 2OH + 2CH3NCH3. The computed reaction cross section for pathways 1 and 2 are as follows: 17.89 
 0.20 Å2 and 3.28 
 0.03 Å2, whereas the computed microcanonical reaction rate constants for pathways 1 and 2 are as follows: (4.21 
 0.05)*10−10 and (7.72 
 0.07)*10−11 cm3/(molecule sec). Both pathways follow direct and indirect H abstraction processes. Among the direct pathways, stripping and rebound mechanisms have been observed, whereas the indirect pathway involves formation of a post‐reaction complex having lifetime ~0.4–0.5 ps. The velocity scattering angle distribution for the reaction is dominated by scattering in the sideways (60–120
) and backward (120–180
) directions with some contribution from the scattering in the forward direction (0–60
).
Electron ionization mass spectrometric fragmentation and multiple reaction monitoring quantification of ferulic and p‐coumaric acid trimethylsilyl derivatives in deposited atmospheric particles
Authors: Rontani Jean‐François , Charrière Bruno , Aubert Dominique , Menniti Christophe , Vaultier Frédéric , Aubert Claude
Published: March 2022

Rationale

Ferulic and p‐coumaric acids are important biological and structural components of plant cell walls and possess antioxidant and antimicrobial properties. These phenolic acids are widespread in environmental samples. However, when they are present at very low concentrations or in very complex lipid extracts, their identification and quantification can be challenging.

Methods

The electron ionization mass spectrometry (EI‐MS) fragmentation pathways of ferulic and p‐coumaric acid trimethylsilyl (TMS) derivatives were investigated. These pathways were deduced by (i) low‐energy collision‐induced dissociation (CID) gas chromatography (GC)/EI‐MS/MS, (ii) accurate mass measurement, and (iii) 13C labelling. These compounds were then characterized and quantified in multiple reaction monitoring (MRM) mode in total lipid extracts of deposited atmospheric particles using highly specific transitions based on the main fragmentation pathways elucidated.

Results

Low‐energy CID‐MS/MS analyses, accurate mass measurement and 13C labelling enabled us to elucidate EI‐MS fragmentations of ferulic and p‐coumaric acid TMS derivatives. Some specific fragmentations proved useful for subsequent characterization and quantification of these compounds. As an application of some of the described fragmentations, trace amounts of these phenolic acids were characterized and quantified in MRM mode in wet‐ and dry‐deposited atmospheric particles containing low proportions of organic matter.

Conclusions

EI‐MS fragmentations of ferulic and p‐coumaric acid TMS derivatives exhibit specific fragment ions that can be very useful for the quantification of trace amounts of both phenolic acids in environmental samples.
Intermittent state estimation for nonlinear delay systems with redundant communication channels
Authors: Guo Yuru , Yang Lixin , Rao Hongxia , Lin Ming , Xu Yong
Published: March 2022

This article investigates state estimation for discrete‐time nonlinear systems with Markov delay, where a redundant communication channel is considered to improve transmission reliability. As the channel capacity is limited, we use two Bernoulli stochastic variables to describe the packet dropout conditions of the main channel and the redundant one. In addition, a mode‐dependent estimator based on both the current state and the delayed state is designed. Combining with an intermittent approach, the efficiency of the estimator is improved. An augmented estimation error system is proposed to deal with the Markov delay in the nonlinear system. Subsequently, a sufficient condition is obtained to ensure the asymptotic stability of the augmented error system by constructing a Lyapunov function, and the gains of the intermittent estimator are derived. Finally, a numerical example of a moving vehicle is utilized to illustrate the developed results.
L–Cysteine Modulated ZIF for Deriving Nitrogen‐Doped Porous Carbon: A Highly Efficient and Stable Electrocatalyst for Oxygen Reduction Reactions
Authors: Gan Xingyu , Wang Yun , Guo Xinjie , Wang Fengxiang , Mao Guojiang , Lv Xiaoxia , Wang Hua
Published: March 2022

Zeolitic Imidazolate Frameworks (ZIFs) derived nitrogen‐doped porous carbon (NPC) materials have been proposed as promising metal‐free electrocatalysts for oxygen reduction reactions (ORR). Herein, we report a strategy to control the morphology of ZIF‐8 and ZIF material‐derived NPC materials by the amount of L‐cysteine. The prepared NPC electrocatalysts exhibit different morphologies and ORR properties. The best of these catalysts exhibited a nanosheet‐like morphology with an onset potential of 0.95 V and a half‐wave potential of 0.87 V in alkaline media, which are comparable to those of commercial Pt/C (20 wt%) catalysts. In addition, this catalyst exhibited high stability and methanol resistance. This work not only reveals the effect of L‐cysteine amount on the growth process of ZIF, but also provides a strategy for designing various excellent catalysts in the fuel cell field.
Synthesis of 1,2‐Propylene Glycol in a Continuous Down‐Flow Fixed‐Bed Reactor With Cu/Al2O3Catalyst
Authors: Dmitriev Georgy S. , Melchakov Ilia S. , Samoilov Vadim O. , Ramazanov Dzhamalutdin N. , Zanaveskin Leonid N.
Published: March 2022

Glycerol hydrogenolysis to 1,2‐propylene glycol in a continuous down‐flow fixed‐bed reactor with 60 %Cu/Al2O3catalyst was investigated. The routes of main, intermediate and by‐products formation were proposed. It is shown that an increase in the catalyst particle size from 0.1–0.16 to 1.6–2.5 mm transfers the process from the kinetic mode to an intermediate mode between the kinetic and internal diffusion controlled reaction rate. In this case, the observed activation energy decreased by 30 %. The optimal conditions for the process have been determined.
Polystyrene‐Coated Magnetite Nanoparticles Based Dispersive Micro‐Solid Phase Extraction of Active Pharmaceutical Ingredients of Antidepressant Drugs and Determination by GC‐MS
Authors: Bozyiğit Gamze D. , Zaman Buse T. , Özdemir Oğuz K. , Kılınç Yağmur , Chormey Dotse S. , Engin Güleda O. , Bakırdere Sezgin
Published: March 2022

A dispersive micro‐solid phase extraction (D‐μ‐SPE) method based on polystyrene coated magnetic nanoparticles (PS@MNPs) was used to preconcentrate the active ingredients of three antidepressant drugs from aqueous solution to be determined by gas chromatography mass spectrometry. Eight prominent parameters of the D‐μ‐SPE method were optimized univariately to boost the recovery and extraction efficiency of the analytes. The three analytes recorded very low detection limits between 0.40 and 0.60 ng/mL, and the dynamic range was broad with high linearity. Medical wastewater was selected as test sample to evaluate the method's applicability and accuracy, and the percent recovery results obtained ranged between 90 and 98 % for two different spike concentrations. The proximity of the recovery results to 100 % and the low standard deviations validated the developed method's accuracy and precision, respectively.
Electrosprayed Regeneration‐Enhancer‐Element Microspheres Power Osteogenesis and Angiogenesis Coupling
Authors: Xu Tianpeng , Yang Yuhe , Suo Di , Bei Ho Pan , Xu Xiaoxiao , Zhao Xin
Published: March 2022

Electrosprayed microspheres for bone regeneration are conventionally restricted by the lack of osteogenic modulation for both encapsulated stem cells and surrounding cells at the defect site. Here, sodium alginate microspheres encapsulating L‐arginine doped hydroxyapatite nanoparticles (Arg/HA NPs) and bone mesenchymal stem cells (BMSCs) as regeneration‐enhancer‐element reservoirs (Arg/HA‐SA@BMSC) for bone healing are electrosprayed. The Arg/HA NPs serve as a container of L‐arginine and Ca2+ and the BMSCs inside the microspheres metabolize the released L‐arginine into bioactive gas nitric oxide (NO) in the presence of Ca2+ to activate the nitric oxide (NO)/cyclic guanosine monophosphate (cGMP) signaling pathway. Meanwhile, the generated NO diffuses out of the microspheres together with the Ca2+ and L‐arginine as exterior enhancers to promote the osteogenesis–angiogenesis coupling of surrounding BMSCs and endothelial cells (ECs) at the bone defect site, generating an internal/external modulation loop between the encapsulated cells and surrounding native cells. It is demonstrated that such regeneration‐enhancer‐element reservoirs could effectively increase the bone tissue formation and neovasculature using rat calvarial defect models. It is envisioned that the microsphere system could streamline vascularized bone regeneration therapy as a high throughput, minimally invasive yet highly effective strategy to accelerate bone healing.
Harnessing the 2D Structure‐Enabled Viscoelasticity of Graphene‐Based Hydrogel Membranes for Chronic Neural Interfacing
Authors: Xiong Zhiyuan , Huang Wenhui , Liang Qinghua , Cao Yang , Liu Shuyi , He Zicong , Zhang Ranran , Zhang Bin , Green Rylie , Zhang Shuixing , Li Dan
Published: March 2022

Stiffness and viscoelasticity of neural implants regulate the foreign body response. Recent studies have suggested the use of elastic or viscoelastic materials with tissue‐like stiffness for long‐term neural electrical interfacing. Herein, the authors find that a viscoelastic multilayered graphene hydrogel (MGH) membrane, despite exhibiting a much higher Young's modulus than nerve tissues, shows little inflammatory response after 8‐week implantation in rat sciatic nerves. The MGH membrane shows significant viscoelasticity due to the slippage between graphene nanosheets, facilitating its seamless yet minimally compressive interfacing with nerves to reduce the inflammation caused by the stiffness mismatch. When used as neural stimulation electrodes, the MGH membrane can offer abundant ion‐accessible surfaces to bring a charge injection capacity 1–2 orders of magnitude higher than its traditional Pt counterpart, and further demonstrates chronic neural therapy potential in low‐voltage modulation of rat blood pressure. This work suggests that the emergence of 2D nanomaterials and particularly their unique structural attributes can be harnessed to enable new bio‐interfacing design strategies.
Translator Identity and the Development of Multilingual Resources for Language Learning
Authors: Afreen Asma
Published: March 2022

Although a range of studies suggest that translation is a valuable pedagogical tool for language learning, the process of translation has not been adequately investigated. Further, the identity of the translator is invisible in much research on translation. To address these gaps in the field, the author draws on a self‐study of her translation of English books into Bangla and uses narrative inquiry methods to investigate the process of translation and the negotiation of identity. Drawing its theoretical underpinnings from Norton’s work on identity (Darvin & Norton, 2015; Norton, 2013), the author investigates how she navigated her translator identity with respect to investment, capital, and ideology. Extending Nida’s formal and functional equivalence in translation (Nida & de Waard, 1986), the author develops a “continuum of equivalence” model to facilitate decision‐making in the translation process and illustrates how she used this model in her English‐Bangla translations. Drawing on her study, the author makes the case that the model could enhance the use of translation as a pedagogical tool to promote language learners’ critical language awareness, multicultural knowledge, and creative thinking. Further, her study makes visible the identity of the translator, an important stakeholder in the promotion of multilingualism in language education internationally.
Unpacking everyday urbanism: Practices and the making of (un)even urban waterscapes
Authors: Rusca Maria , Cleaver Frances
Published: March 2022

Inequalities in conditions of access to water are emblematic of contemporary urban life and have long been at the center of urban scholarship. This paper considers the theoretical and empirical potential of a focus on the everyday as a contribution to critical urban water studies. Drawing on research in Political Ecology and Critical Institutionalism, we focus on the intersection of everyday urbanism and water to reflect on whether such perspectives can further understandings of socio‐natural inequalities and “real” governance challenges in the urban waterscape. We suggest that a focus on the everyday brings attention to the hybrid arrangements that constitute urban waterscapes and offers new insights to the polycentric nature of water governance, agency, and everyday urban struggles. However, we also outline limitations of these studies in unpacking the concept of the everyday and in capturing the practices through which everyday life is constituted. We explore the potential of an engagement with Practice Theory as a sensitizing lens for developing grounded understandings of everyday life, its constituent practices, and how these change over time. Concurrently, we argue that Practice Theory could be strengthened by drawing on critical approaches that explain everyday urban governance through: (1) the linking of practices to broader patterns of inequality; (2) the multiple social identities of practitioners and the variability in their exercise of agency; (3) the role of institutions as crucial mediating mechanisms and the processes through which practices become enduring institutional arrangements. We, thus, conclude that these approaches are complementary rather than competing.

This article is categorized under:

Human Water > Water Governance
The Talk of the Town: Community Perspectives on Loot Boxes
Authors: Macey Joseph , Bujić Mila
Published: March 2022

Loot boxes are a common monetization mechanic in the contemporary games industry. However, an increasing number of regulatory bodies have been investigating loot boxes, with several having concluded that they constitute gambling. There is, however, a lack of consensus, with some authorities concentrating on the way loot boxes are obtained, while others consider the value of their contents. Overwatch is particularly affected by this disparity as it remains legal in some jurisdictions but not in others. In order to understand the role and function of loot boxes, an expert analysis must be complemented with consumer voices. This chapter utilizes content analysis to investigate discussions of loot boxes in Overwatch fan communities, identifying several prominent themes: monetization, effects, contents, gambling, regulation, alternatives, and their specifics in Overwatch.
Two Overwatch Player Profiles
Authors: Vahlo Jukka , Karhulahti Veli-Matti
Published: March 2022

We pursue Overwatch player profiles via a statistical cluster analysis of survey data from the UK (N = 1089) and the USA (N = 417). The profiles are based on the players’ activity, challenge, and experiential preferences as well as motivations. Our analytical process produces six esports player clusters, two of which with Overwatch. The first (OW1) plays mainly Overwatch and Fortnite on a console, and they enjoy diverse types of non-competitive play elements more than other esports players. The second cluster (OW2) plays mainly Overwatch and League of Legends on a PC, and despite appearing more “competitive”, they did not report more competitive preferences. We suggest that the alleged “casual” and “competitive” types might not be the best way to identify esports and Overwatch players.
Overwatch Fandom and the Range of Corporate Responses
Authors: Wirman Hanna , Jones Rhys
Published: March 2022

Official responses to Overwatch fan creations from Blizzard Entertainment range from public endorsement to legal actions against the fans. This chapter illustrates, through examples from modding, fan art, fan fiction, and cosplay, how fan contributions are often results of official fan activities and sometimes become included in the actual game itself. This chapter focuses on exploring the authorship and ownership dynamics in game elements that become reworked by fans, shared in fan communities, and either censored, neglected, or endorsed by Blizzard Entertainment. Focusing on the game’s carefully crafted hero characters and related fanworks, this chapter demonstrates that Overwatch heroes are not only simultaneously developed by both fans and paid developers but transformed by fans into notable works beyond their original design.
Locational error in the estimation of regional discrete choice models using distance as a regressor
Authors: Arbia Giuseppe , Berta Paolo , Dolan Carrie B.
Published: March 2022

In many microeconometric studies distance from a relevant point of interest (such as a hospital) is often used as a predictor in a regression framework. Confidentiality rules, often, require to geo-mask spatial micro-data, reducing the quality of such relevant information and distorting inference on models’ parameters. This paper extends previous literature, extending the classical results on the measurement error in a linear regression model to the case of hospital choice, showing that in a discrete choice model the higher is the distortion produced by the geo-masking, the higher will be the downward bias in absolute value toward zero of the coefficient associated to the distance in the models. Monte Carlo simulations allow us to provide evidence of theoretical hypothesis. Results can be used by the data producers to choose the optimal value of the parameters of geo-masking preserving confidentiality, not destroying the statistical information.