bluuebunny/crossref_metadata_2025 huggingface dataset:
Lie Theory Suffices to Resolve the Local Classical Problem of Time
Authors: Anderson Edward
Published: May 2021

The problem of time - a foundational question in quantum gravity - is due to conceptual gaps between GR and physics' other observationally-confirmed theories. Its multiple facets originated with Wheeler-DeWitt-Dirac over 50~years ago. They were subsequently classified by Kucha\v{r}-Isham, who argued that most of the problem is facet interferences and posed the question of how to order the facets. We show the local classical level facets are two copies of Lie theory with a Wheelerian two-way route therebetween. This solves facet ordering and facet interference. Closure by a Lie algorithm generalization of Dirac's algorithm is central.
Quantum Stochastic Products and the Quantum Convolution
Authors: Aniello Paolo
Published: May 2021

A quantum stochastic product is a binary operation on the space of quantum states preserving the convex structure. We describe a class of associative stochastic products, the twirled products, that have interesting connections with quantum measurement theory. Constructing such a product involves a square integrable group representation, a probability measure and a fiducial state. By extending a twirled product to the full space of trace class operators, one obtains a Banach algebra. This algebra is commutative if the underlying group is abelian. In the case of the group of translations on phase space, one gets a quantum convolution algebra, a quantum counterpart of the classical phase-space convolution algebra. The peculiar role of the fiducial state characterizing each quantum convolution product is highlighted.
Canonical Almost Geodesic Mappings of the First Type of Spaces with Affine Connection Onto Generalized 2-Ricci-Symmetric Spaces
Authors: Berezovski Volodymyr , Cherevko Yevhen , Leshchenko Svitlana , Mikes Josef
Published: May 2021

In the paper we consider almost geodesic mappings of the first type of spaces with affine connections onto generalized 2-Ricci-symmetric spaces. The main equations for the mappings are obtained as a closed system of linear differential equations of Cauchy type in the covariant derivatives. The obtained result extends an amount of research produced by Sinyukov, Berezovski and Mike\v{s}.
Some Structural Properties of Semidirect Sums of \(\mathfrak{so}(3)\) and Abelian Lie Algebras
Authors: Campoamor-Stursberg Rutwig
Published: May 2021

Various structural properties of semidirect sums of the rotation Lie algebra of rank one and an Abelian algebra described in terms of real representations with at most two irreducible constituents are obtained. The stability properties of these semidirect sums are studied by means of the cohomological and the Jacobi scheme methods.
Novel cell types and developmental lineages revealed by single-cell RNA-seq analysis of the mouse crista ampullaris
Authors: Wilkerson Brent A , Zebroski Heather L , Finkbeiner Connor R , Chitsazan Alex D , Beach Kylie E , Sen Nilasha , Zhang Renee C , Bermingham-McDonogh Olivia
Published: May 2021

This study provides transcriptomic characterization of the cells of the crista ampullaris, sensory structures at the base of the semicircular canals that are critical for vestibular function. We performed single-cell RNA-seq on ampullae microdissected from E16, E18, P3, and P7 mice. Cluster analysis identified the hair cells, support cells and glia of the crista as well as dark cells and other nonsensory epithelial cells of the ampulla, mesenchymal cells, vascular cells, macrophages, and melanocytes. Cluster-specific expression of genes predicted their spatially restricted domains of gene expression in the crista and ampulla. Analysis of cellular proportions across developmental time showed dynamics in cellular composition. The new cell types revealed by single-cell RNA-seq could be important for understanding crista function and the markers identified in this study will enable the examination of their dynamics during development and disease.
Live-imaging of endothelial Erk activity reveals dynamic and sequential signalling events during regenerative angiogenesis
Authors: Okuda Kazuhide S , Keyser Mikaela S , Gurevich David B , Sturtzel Caterina , Mason Elizabeth A , Paterson Scott , Chen Huijun , Scott Mark , Condon Nicholas D , Martin Paul , Distel Martin , Hogan Benjamin M
Published: May 2021

The formation of new blood vessel networks occurs via angiogenesis during development, tissue repair, and disease. Angiogenesis is regulated by intracellular endothelial signalling pathways, induced downstream of vascular endothelial growth factors (VEGFs) and their receptors (VEGFRs). A major challenge in understanding angiogenesis is interpreting how signalling events occur dynamically within endothelial cell populations during sprouting, proliferation, and migration. Extracellular signal-regulated kinase (Erk) is a central downstream effector of Vegf-signalling and reports the signalling that drives angiogenesis. We generated a vascular Erk biosensor transgenic line in zebrafish using a kinase translocation reporter that allows live-imaging of Erk-signalling dynamics. We demonstrate the utility of this line to live-image Erk activity during physiologically relevant angiogenic events. Further, we reveal dynamic and sequential endothelial cell Erk-signalling events following blood vessel wounding. Initial signalling is dependent upon Ca2+ in the earliest responding endothelial cells, but is independent of Vegfr-signalling and local inflammation. The sustained regenerative response, however, involves a Vegfr-dependent mechanism that initiates concomitantly with the wound inflammatory response. This work reveals a highly dynamic sequence of signalling events in regenerative angiogenesis and validates a new resource for the study of vascular Erk-signalling in real-time.
Crafting Collections between Vernacular and Institutional Practice
Authors: Graden Lizette
Published: May 2021

This paper is based on ethnographic fieldwork and applies theories of crafting and performance to explore how living heritage practices are rethought, reframed, and refashioned when traditional dress and individual garments are moved, reorganized, and transformed into a collection following rationales derived from both family tradition and museum standards. By following one woman’s emerging collections, the study sheds light on ways of materializing relationships and shaping curatorial agency through acts of crafting. The study aims to show how deeper understanding of vernacular crafting of collections may inform institutional curatorial practice and heritage-making.
Tutankhamun’s collar
Authors: Ekstedt Bjersing Marie
Published: May 2021

The aim of this paper is to discuss what happens when repeating a reconstruction of the same textile. The author of this article is also the craftsperson that made the four reconstructions presented. The original collar reconstructed belonged to Tutankhamun. The collar is circular, woven in a circle. Before the reconstructions, this method of weaving circular shapes had not been described. The first reconstruction focused on the collar. Fifteen years later, three additional reconstructions were made. This time, the focus was to reconstruct the craft, by the use of fewer, simpler tools. Parallel to practical work there was an exploration of how to make documentation. One conclusion in the project is when changing focus from reconstructing a textile to reconstructing a craft, more similarity to the original was achieved.
‘It's in my hands’
Authors: Westerlund Tina
Published: May 2021

Craft knowledge is built from examples of experience, and when experiences from many people are gathered and compared, new knowledge is developed. This requires either socialization between practitioners or a systematic collection of practice descriptions, such as in a manual. However, there is always a risk that knowledge that is difficult to put into words will never be communicated. The aim of this paper is to show how theoretical perspectives can be used as analytical tools to help us develop methods that support the communication of craft knowledge. Using an approach of research through practice in the field of gardening, and combining a tripartite theory of knowledge with a SECI-model analysis, I will discuss how it is possible to make practitioners’ subjective knowledge more readily available to others.
In-vitro Antacid Properties of Cameroonian Clay (MY41g) and its Potential Use in Anti-ulcer Triple Therapy Regimen Formulated with Eremomastax speciosa Extract
Authors: Emakoua Joseph Fleurie , Mimosette Mesmine Kuissu Teukam , Amang André Perfusion , Essama Mbida Désirée , Ndji Otto Gustave Lebeau , Mezui Christophe , Enonchong Enow-Orock George , Tan Paul Vernyuy
Published: May 2021

Aims: The antisecretory, antibacterial on Helicobacter, and antacid properties of Eremomastax speciosa (E. speciosa) and MY41g clay respectively, led us to evaluate the potential use of this clay in the anti-ulcer tri-therapy formulated with Eremomastax speciosa.

Place and Duration of Study: Department of Animal Biology & Physiology (Animal Physiology Laboratory), Faculty of Science, University of Yaoundé I, between August 2020 and February 2021.  

Materials and Methods: In vitro antacid were evaluated by studying: Fordtran's method, and the influence of temperature on the pH values. In vivo activity was studied on chronic gastric ulcers induced by injection of 0.05 ml of acetic acid (30%) into the stomach wall. Rats were treated daily for 10 days after ulcer induction with a combination of E. speciosa and MY41g (ESMY) ; (ESMY 100+250 and 200+250 mg/kg). The model of "unhealed" gastric ulcers was also used: from day 5 to day 18 of experimentation, rats were given ESMY orally concomitantly with indomethacin (1 mg/kg/day) subcutaneously. Ulcer index, percentage of healing, mucus secretion, gastric acidity, histological, hematological, and oxidative stress parameters were evaluated.

Results: ESMY showed good neutralizing capacity in vitro in Fordtran’s method. Treatment with ESMY accelerated the spontaneous healing of chronic gastric ulcers (93.82-96.14%). However, administration of indomethacin did not induce significant variations in the percentage of healing (90.73-94.60%). For both ulcer models performed, ulcer healing was accompanied by a significant (P = 0.001) increase in mucus mass at 200/250 mg/kg. ESMY increased antioxidant activity, decreased gastric acidity, lipid peroxidation, and maintained hematological balance.

Conclusion: In addition to its buffering properties, the healing mechanism of ESMY includes reduced gastric acidity, enhanced mucus production, re-epithelialization of gastric mucosa, improvement of hematological and antioxidant status. ESMY can be used in traditional medicine, as a therapeutic regimen against gastric ulcers.
Off-centered Ball Resolution Through Multi-hole Process Plate Implementation at Wirebond Process
Authors: Pulido J. , Gomez F. R. , Graycochea Jr. E.
Published: May 2021

With the continuous trend of new technologies in semiconductor manufacturing assembly, challenges and issues are unavoidable. This paper presents the modification and improvement done on the process plate design to eliminate the bouncing effect of the silicon die that leads to off-centered ball (OCB) reject during the formation of wire on a quad flat no-leads (QFN) device. The panel type single-row process plate cannot totally vacuum the warped leadframe and this is resulting to off-centered ball. Through changing the panel type single-row process plate to panel type multi-hole process will have a strong vacuum sucked underneath the leadframe and eliminates the occurrence of off-centered ball. Future works could use the improved process plate design for devices of similar configuration.
Maximizing the Process Capability of Singulation Machine by Dual Work Piece Cutting on Circular Tape Frame
Authors: Mendoza Mariane , Buera Maria Virginia , Gomez Frederick Ray
Published: May 2021

Tape saw singulation is the process where a strip was mounted on the tape attached on the frame and then sawn into single units. Circular tape saw singulation only caters one panel of the two-paneled strip which was found to be consuming with the machine capacity and resources. Driven by continuously growing volumes of customer demands at the Philippines for the past two years, it was a challenge for the machine to maximize its capacity while minimizing the cost and resources. Opportunity was found on exploring the idea of dual work piece where two strip panels were catered by one circular tape frame. Dual work piece application would not only maximize the machine capability and capacity but also reduce the cost of resources consumed per strip loading. In this study, the authors have explored the workability of dual work piece cutting where two panels can be catered on one circular frame instead of the current one panel per circular frame. Dual Work Piece application was found to be effective to achieve the goal of maximizing the machine capacity while trimming down the expenses by 50% that was brought about by the resources demanded to process the strips at singulation. With the results of the study, it was recommended for the dual work piece cutting be applied and explored on growing semiconductor industry.
A weak COPI binding motif in the cytoplasmic tail of SARS‐CoV‐2 spike glycoprotein is necessary for its cleavage, glycosylation, and localization
Authors: Jennings Benjamin C. , Kornfeld Stuart , Doray Balraj
Published: May 2021

The SARS‐CoV‐2 spike glycoprotein (spike) mediates viral entry by binding ACE2 receptors on host cell surfaces. Spike glycan processing and cleavage, which occur in the Golgi network, are important for fusion at the plasma membrane, promoting both virion infectivity and cell‐to‐cell viral spreading. We show that a KxHxx motif in the cytosolic tail of spike weakly binds the COPβ’ subunit of COPI coatomer, which facilitates some recycling of spike within the Golgi, while releasing the remainder to the cell surface. Although histidine (KxHxx) has been proposed to be equivalent to lysine within di‐lysine endoplasmic reticulum (ER) retrieval sequences, we show that histidine‐to‐lysine substitution (KxKxx) retains spike at the ER and prevents glycan processing, protease cleavage, and transport to the plasma membrane.
Material Deprivation
Authors: Ivaldi Enrico , Ciacci Andrea
Published: May 2021

One of the best‐known definitions of “material deprivation” is provided by Townsend, according to which material deprivation refers to “a state of observable and demonstrable disadvantage in relation to the local community or the wider society or nation to which an individual, family or group belongs. The idea has come to be applied to conditions (that is, physical, environmental, and social status or circumstances) rather than resources and to specific and not only general circumstances, and therefore can be distinguished from the concept of poverty. The former sure enough can't be context free; it applies to specific circumstances and physical, environmental, and social conditions.

Material deprivation is a complex phenomenon, as it concerns multiple aspects of reality and can be measured in different ways. In this paper, our aim is to highlight the most important elements of deprivation, as well as the analytical assumptions (often underlying and overlooked) that constitute the cornerstone of his study.
Elements of Economics of Uncertainty and Time with Recursive Utility
Authors: Aase Knut K.
Published: May 2021

We address how recursive utility affects important results in the theory of economics of uncertainty and time, as compared to the standard model, where the focus is on dynamic models in discrete time. Several puzzles associated with the standard theory are less puzzling with recursive utility, even if this type of preference representation seems close to the standard one at first sight. The basic difference is that recursive utility allows a form of separation of consumption substitution from risk aversion. This also means that the timing of resolution of uncertainty matters. In dynamic models, however, this turns out to be rather crucial steps.
Alternating Minimization Algorithms
Authors: Hunter David R.
Published: May 2021

The idea of attacking a difficult minimization problem by framing it as two or more separate simpler problems, then iterating between solving these two problems repeatedly, is called alternating minimization. This article demonstrates the exceptional power of this seemingly uncomplicated idea in several ways. First, it briefly introduces the ubiquitous idea of coordinate descent, along with its many generalizations. Second, it considers perhaps the most successful of all statistical algorithms, the EM algorithms, and shows how they are also special cases of alternating minimization as it was originally defined. Finally, it presents several modern high‐dimensional problems that may all be viewed through the lens of alternating minimization.
Streaming Data and Data Streams
Authors: Kolajo Taiwo , Daramola Olawande , Adebiyi Ayodele
Published: May 2021

Recent advances in computer networking, smart cities, smart grid, remote sensing, surveillance, telecommunication, and social media have led to a high volume of streaming data. The amount of data generated for the past two years is more than what has been in the history of the entire human race. This high volume, high‐traffic, and brief life‐span data need online analysis and intelligent processing to uncover useful and exciting information that is contained in them. To expand the existing knowledge in the domain of data science, broad areas on streaming data and data streams, which embrace data stream mining issues, streaming data tools and technologies, streaming data pre‐processing, streaming data algorithms, and strategies for processing data streams, were discussed in this article. The article also recommends the best practices for managing data streams and suggests the way forward.
Increased systemic HSP70B levels in spinal muscular atrophy infants
Authors: Eichelberger Eric J. , Alves Christiano R. R. , Zhang Ren , Petrillo Marco , Cullen Patrick , Farwell Wildon , Hurt Jessica A. , Staropoli John F. , Swoboda Kathryn J.
Published: May 2021

Despite newly available treatments for spinal muscular atrophy (SMA), novel circulating biomarkers are still critically necessary to track SMA progression and therapeutic response. To identify potential biomarkers, we performed whole‐blood RNA sequencing analysis in SMA type 1 subjects under 1 year old and age‐matched healthy controls. Our analysis revealed the Heat Shock Protein Family A Member 7 (HSPA7)/heat shock 70kDa protein 7 (HSP70B) as a novel candidate biomarker to track SMA progression early in life. Changes in circulating HSP70B protein levels were associated with changes in circulating neurofilament levels in SMA newborns and infants. Future studies will determine whether HSP70B levels respond to molecular therapies.
Adaptive prescribed performance control for hydraulic system with disturbance compensation
Authors: Xu Zhangbao , Liu Qingyun , Yao Jianyong
Published: May 2021

In this article, an adaptive prescribed performance controller is developed for hydraulic system with uncertainties. An extraordinary feature is that better prescribed performance control can be achieved by compensating the uncertainties including parameter uncertainties and disturbances. For this reason, the transformation of system output error is realized by a prescribed performance function, which is employed to constrain the boundary of tracking error and convergence rate, then the tracking error of the original system with a priori prescribed performance can be realized by stabilizing the transformed system. Adaptive control is employed to solve the system parametric uncertainties; extended state observers are built to estimate the multiple disturbances. Based on the backstepping method, they are integrated into the design of the novel controller to guarantee prescribed tracking error performance. The stability analysis of the proposed controller is carried out via the Lyapunov theory. Finally, experimental results indicate good performance of the proposed algorithm.
Mechanical Properties of Electrospun Fibers—A Critical Review
Authors: Rashid Taslim Ur , Gorga Russell E. , Krause Wendy E.
Published: May 2021

The mechanical properties of electrospun fibers play an important role in determining their applications. Most of the reported literature measures the mechanical properties of electrospun mats, scaffolds, or films instead of single fibers; however, a basic understanding of the relationship between the mechanical properties of the single fiber and that of the mat is critical to obtain precise information for choosing their application. This Review aims to evaluate the reported mechanical properties of electrospun fibers and the variables that influence those properties. An overview on the recent inputs in the development of mechanical properties of electrospun fibers is given, illustrating attempts to tailor mechanical properties of the fibers and/or mats. The necessity of determining flexible and reliable testing methods to establish testing standards for obtaining consistent and reliable data for both electrospun fibers and mats is also highlighted.
Dose‐Independent Transfection of Hydrophobized Polyplexes
Authors: Zhang Zhen , Qiu Nasha , Wu Shuling , Liu Xin , Zhou Zhuxian , Tang Jianbin , Liu Yanpeng , Zhou Ruhong , Shen Youqing
Published: May 2021

Cationic polymers dynamically complex DNA into complexes (polyplexes). So, upon dilution, polyplexes easily dissociate and lose transfection ability, limiting their in vivo systemic gene delivery. Herein, it is found that polyplex's stability and endocytosis pathway determine its transfection dose‐dependence. The polyplexes of hydrophilic polycations have dose‐dependent integrity and lysosome‐trafficking endocytosis; at low doses, most of these polyplexes dissociate, and the remaining few are internalized and trapped in lysosomes, abolishing their transfection ability. In contrast, the polyplexes of the polycations with optimal hydrophobicity remain integrated even at low concentrations and enter cells via macropinocytosis directly into the cytosol evading lysosomes, so each polyplex can accomplish its infection process, leading to dose‐independent DNA transfection like viral vectors. Furthermore, the tuned hydrophobicity balancing the affinity of anionic poly(γ‐glutamic acid) (γ‐PGA) to the polyplex surface enables γ‐PGA to stick on the polyplex surface as a shielding layer but peel off on the cell membrane to release the naked polyplexes for dose‐independent transfection. These findings may provide guidelines for developing polyplexes that mimick a viral vector's dose‐independent transfection for effective in vivo gene delivery.
Wrapping and Blocking of Influenza A Viruses by Sialylated 2D Nanoplatforms
Authors: Bhatia Sumati , Donskyi Ievgen S. , Block Stephan , Nie Chuanxiong , Burdinski Angelique , Lauster Daniel , Radnik Jörg , Herrmann Andreas , Haag Rainer , Ludwig Kai , Adeli Mohsen
Published: May 2021

Inhibition of respiratory viruses is one of the most urgent topics as underlined by different pandemics in the last two decades. This impels the development of new materials for binding and incapacitation of the viruses. In this work, we have demonstrated that an optimal deployment of influenza A virus (IAV) targeting ligand sialic acid (SA) on a flexible 2D platform enables its binding and wrapping around IAV particles. A series of 2D sialylated platforms consisting graphene and polyglycerol are prepared with different degrees of SA functionalization around 10%, 30%, and 90% named as G‐PG‐SAL, G‐PG‐SAM, and G‐PG‐SAH, respectively. The cryo‐electron tomography (Cryo‐ET) analysis has proved wrapping of IAV particles by G‐PG‐SAM. A confocal‐based colocalization assay established for these materials has offered the comparison of binding potential of sialylated and non‐sialylated nanoplatforms for IAV. With this method, we have estimated the binding potential of the G‐PG‐SAM and G‐PG‐SAH sheets for IAV particles around 50 and 20 times higher than the control sheets, respectively, whereas the low functionalized G‐PG‐SAL have not shown any significant colocalization value. Moreover, optimized G‐PG‐SAM exhibits high potency to block IAV from binding with the MDCK cells.
Nanohybrid Photodetectors
Authors: Wu Judy Z. , Gong Maogang
Published: May 2021

Nanohybrids represent a larger variety of functional materials consisting of one or more types of low‐dimensional semiconductor nanostructures, such as quantum dots, nanowires, nanotubes, 2D atomic materials (graphene, transition‐metal dichalcogenides, etc.) interfaced with one another, and/or with conventional material matrices (bulks, films, polymers, etc.). Heterojunction interfaces are characteristic in nanohybrids and play a critical role facilitating synergistic coupling of constituent materials of different functionalities, resulting in excellent electronic, optoelectronic, and mechanical properties. Therefore, nanohybrids provide fresh opportunities for designs of optoelectronic devices of extraordinary performance in addition to the benefits of low cost, large abundance, flexibility, and light weight. Herein, some recent achievements in exploiting new optoelectronic nanohybrids and understanding the underlying physics toward high‐performance optoelectronic nanohybrids that are competitive in commercialization of various optoelectronic devices are highlighted. Using nanohybrid photodetectors as an example, the importance in controlling the heterojunction interfaces and multiscale controlling of optoelectronic process of light absorption, exciton dissociation, photocarrier transfer, and transport from atomic to device scales and how this control impacts the photodetector performance are revealed. The current status, remaining challenges, and future perspectives in optoelectronic nanohybrids are also discussed.
DNA Assembly‐Based Stimuli‐Responsive Systems
Authors: Lu Shasha , Shen Jianlei , Fan Chunhai , Li Qian , Yang Xiurong
Published: May 2021

Stimuli‐responsive designs with exogenous stimuli enable remote and reversible control of DNA nanostructures, which break many limitations of static nanostructures and inspired development of dynamic DNA nanotechnology. Moreover, the introduction of various types of organic molecules, polymers, chemical bonds, and chemical reactions with stimuli‐responsive properties development has greatly expand the application scope of dynamic DNA nanotechnology. Here, DNA assembly‐based stimuli‐responsive systems are reviewed, with the focus on response units and mechanisms that depend on different exogenous stimuli (DNA strand, pH, light, temperature, electricity, metal ions, etc.), and their applications in fields of nanofabrication (DNA architectures, hybrid architectures, nanomachines, and constitutional dynamic networks) and biomedical research (biosensing, bioimaging, therapeutics, and theranostics) are discussed. Finally, the opportunities and challenges for DNA assembly‐based stimuli‐responsive systems are overviewed and discussed.
Insights into the Development of Monolithic Perovskite/Silicon Tandem Solar Cells
Authors: Chen Bingbing , Ren Ningyu , Li Yucheng , Yan Lingling , Mazumdar Sayantan , Zhao Ying , Zhang Xiaodan
Published: May 2021

In recent years, perovskite/silicon tandem solar cells (PK/c‐Si tandem) have demonstrated high power conversion efficiency (PCE) and demonstrated great application potential in photovoltaic (PV) systems. However, the PCE of PK/c‐Si tandem devices is still below the theoretical limit. From a broader perspective, their poor stability and difficulty in large‐area realization are crucial barriers for commercial viability. In this report, the detailed constraints facing high PCE of tandem devices and the corresponding solutions are discussed. The authors propose that the main obstacle comes from the limitation of the perovskite top cell. However, careful understanding of the optical and electrical properties of each functional layer is expected to be the core process to further promote efficiency. Regarding the environmental and intrinsic instability issues, encapsulation is considered to be the most effective method to address environmental instability. Preventing ion migration is one of the fundamental methods to eliminate intrinsic instability. It is believed that low dimensional perovskite materials will become a competitive solution to simultaneously solve these two instabilities. Finally, some suggestions for reducing costs and preparation of PK/c‐Si tandem on a large‐scale are also discussed which provides guidance for further boosting the development of PK/c‐Si tandem.
The role of nonstandard and precarious jobs in the well‐being of disabled workers during workforce reintegration
Authors: Edmonds Amy T. , Sears Jeanne M. , O'Connor Allyson , Peckham Trevor
Published: May 2021

Background

Nonstandard employment arrangements are becoming increasingly common and could provide needed flexibility for workers living with disabilities. However, these arrangements may indicate precarious employment, that is, employment characterized by instability, powerlessness, and limited worker rights and benefits. Little is known about the role of nonstandard and precarious jobs in the well‐being of disabled persons during workforce reintegration after permanent impairment from work‐related injuries or illnesses.

Methods

We used linked survey and administrative data for a sample of 442 Washington State workers who recently returned to work and received a workers' compensation permanent partial disability award after permanent impairment from a work‐related injury. Multivariable logistic regression models were used to examine associations between nonstandard employment and outcomes related to worker well‐being and sustained employment. We also examined associations between a multidimensional measure of precarious employment and these outcomes. Secondarily, qualitative content analysis methods were used to code worker suggestions on how workplaces could support sustained return to work (RTW).

Results

Workers in: (1) nonstandard jobs (compared with full‐time, permanent jobs), and (2) precarious jobs (compared with less precarious jobs) had higher adjusted odds of low expectations for sustained RTW. Additionally, workers in precarious jobs had higher odds of reporting fair or poor health and unmet need for disability accommodation. Workers in nonstandard and precarious jobs frequently reported wanting safer and adequately staffed workplaces to ensure safety and maintain sustained employment.

Conclusions

Ensuring safe, secure employment for disabled workers could play an important role in their well‐being and sustained RTW.
Validation and demonstration of a new comprehensive model of Alzheimer's disease progression
Authors: Stern Yaakov , Stallard Eric , Kinosian Bruce , Zhu Carolyn , Cosentino Stephanie , Jin Zhezhen , Gu Yian
Published: May 2021

Introduction

Identifying the course of Alzheimer's disease (AD) for individual patients is important for numerous clinical applications. Ideally, prognostic models should provide information about a range of clinical features across the entire disease process. Previously, we published a new comprehensive longitudinal model of AD progression with inputs/outputs covering 11 interconnected clinical measurement domains.

Methods

Here, we (1) validate the model on an independent cohort; and (2) demonstrate the model's utility in clinical applications by projecting changes in 6 of the 11 domains.

Results

Survival and prevalence curves for two representative outcomes—mortality and dependency—generated by the model accurately reproduced the observed curves both overall and for patients subdivided according to risk levels using an independent Cox model.

Discussion

The new model, validated here, effectively reproduces the observed course of AD from an initial visit assessment, allowing users to project coordinated developments for individual patients of multiple disease features.
Network dysfunction in cognitively normal APOE ε4 carriers is related to subclinical tau
Authors: Butt Omar H. , Meeker Karin L. , Wisch Julie K. , Schindler Suzanne E. , Fagan Anne M. , Benzinger Tammie L.S. , Cruchaga Carlos , Holtzman David M. , Morris John C. , Ances Beau M.
Published: May 2021

Introduction

Apolipoprotein E (APOE) ε4 allele status is associated with amyloid and tau‐related pathological changes related to Alzheimer's disease (AD). However, it is unknown whether brain network changes are related to amyloid beta (Aβ) and/or tau‐related pathology in cognitively normal APOE ε4 carriers with subthreshold Aβ accumulation.

Methods

Resting state functional connectivity measures of network integrity were evaluated in cognitively normal individuals (n = 121, mean age 76.6 ± 7.8 years, 15% APOE ε4 carriers, 65% female) with minimal Aβ per cerebrospinal fluid (CSF) or amyloid positron emission tomography.

Results

APOE ε4 carriers had increased lateralized connections relative to callosal connections within the default‐mode, memory, and salience networks (P = .02), with significant weighting on linear regression toward CSF total tau (P = .03) and CSF phosphorylated tau at codon 181 (P = .03), but not CSF Aβ42.

Discussion

Cognitively normal APOE ε4 carriers with subthreshold amyloid accumulation may have network reorganization associated with tau.
Introduction of a Luminophore into Generic Polymers via Mechanoradical Coupling with a Prefluorescent Reagent
Authors: Kubota Koji , Toyoshima Naoki , Miura Daiyo , Jiang Julong , Maeda Satoshi , Jin Mingoo , Ito Hajime
Published: May 2021

Herein, we report a novel strategy for introducing a luminophore into generic polymers facilitated by mechanical stimulation. In this study, polymeric mechanoradicals were formed in situ under ball‐milling conditions to undergo radical–radical coupling with a prefluorescent nitroxide‐based reagent in order to incorporate a luminophore into the polymer main chains via a covalent bond. This method allowed the direct and conceptually simple preparation of luminescent polymeric materials from a wide range of generic polymers such as polystyrene, polymethyl methacrylate, and polyethylene. These results indicate that the present mechanoradical coupling strategy may help to transform existing commodity polymers into more valuable functional materials.
Scholl Reaction of Perylene‐Based Polyphenylene Precursors under Different Conditions: Formation of Hexagon or Octagon?
Authors: Zou Ya , Han Yi , Wu Shaofei , Hou Xudong , Chow Chi Hao Eugene , Wu Jishan
Published: May 2021

A planar dibenzo‐peri‐hexacene derivative (2) was synthesized via FeCl3‐mediated Scholl reaction from a cyclopenta‐fused perylene (CP) based polyphenylene precursor (1). However, an unexpected octagon‐containing, negatively curved molecule (3) was obtained in nearly quantitative yield when 2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone (DDQ) and methanesulfonic acid (MeSO3H) were used. Similar results were observed when two smaller‐sized precursors containing one (4) or two CP units (5) were tested. X‐ray crystallographic analysis also revealed that there is no close π–π stacking between neighboring π‐conjugated skeletons. DFT calculations suggest a radical cation mechanism in the presence of FeCl3 while an arenium ion pathway for the DDQ/MeSO3H mediated Scholl reaction, which can well explain the selective formation of hexagons and octagons under different conditions. The obtained compounds showed tunable optical and electrochemical properties.
Polyaniline grafted chitosan/GO‐CNT/Fe3O4 nanocomposite as a superior electrode material for supercapacitor application
Authors: Hosseini Mir Ghasem , Shahryari Elham , Yardani Sefidi Pariya
Published: May 2021

Developing appropriate stable electroactive electrode materials for supercapacitor application is the challenging issue, which attracts enormous attention in recent decades. In this regard, Fe3O4 nanoparticles are firstly synthesized on chitosan/graphene oxide‐multiwall carbon nanotubes (CS/GM/Fe3O4). Then, polyaniline (PANI) is grafted on it via in situ chemical polymerization and named as CS/GM/Fe3O4/PANI. The as‐prepared nanocomposites are characterized by Field emission scanning electron microscopy, Fourier transform infrared spectroscopy, X‐ray diffraction, X‐ray photoelectron spectroscopy, and energy dispersive X‐ray spectroscopy. The capacitive properties of the electrodes are investigated in a three electrode configuration in 0.5 M Na2SO4 electrolyte by various electrochemical techniques. The specific capacitance of CS/GM/Fe3O4/PANI electrode is 1513.4 Fg−1 at 4 Ag−1 which is 1.9 times higher than that of CS/GM/Fe3O4 (800 Fg−1). Meanwhile, the electrodes exhibit appropriate cycle life along with 99.8% and 93.95% specific capacitance at 100 Ag−1 for chitosan/GO‐CNT/Fe3O4 and polyaniline grafted chitosan/GO‐CNT/Fe3O4, respectively.
Toughness improvement of poly(lactic acid) with poly(vinyl propionate)‐grafted natural rubber
Authors: Jaratrotkamjorn Ruedee , Tanrattanakul Varaporn
Published: May 2021

Natural rubber (NR) grafted with poly(vinyl propionate) (NR‐g‐PVP) was prepared by emulsion polymerization. The monomer content was set at 5, 10, 20, and 30 wt%. The chemical structure of NR‐g‐PVP was confirmed by 1H‐NMR and FTIR techniques. The grafting parameters of purified NR‐g‐PVP were evaluated. Binary (PLA/NR and PLA/NR‐g‐PVP) and ternary (PLA/NR/NR‐g‐PVP) blends were prepared by melt blending using a twin‐screw extruder. The percentage of grafted PVP on NR affected morphology, thermal and mechanical properties of the blends. In binary blends, 5% grafting showed the greatest improvement of toughness and ductility with PLA, whereas there was no improvement in the mechanical properties of PLA/NR blend from using NR‐g‐PVP as a compatibilizer. The mechanical properties of the blends are related to mutual compatibility of the components. Good interfacial adhesion and proper particle size of NR were the key factors contributing to mechanical properties.
The study of optical and photodielectric properties of polymethyl methacrylate and tris‐(8‐hydroxy‐quinoline) aluminum (Alq3) composites
Authors: Vuković Danijela , Škipina Blanka , Maletić Slavica , Cerović Dragana D. , Duvenhage Mart‐Mari , Luyt Adriaan Stephanus , Mirjanić Dragoljub , Dudić Duško
Published: May 2021

Polymer composite films of tris‐(8‐hydroxy‐quinoline) aluminum (Alq3) and polymethyl methacrylate (PMMA) at two different concentrations were investigated. Dielectric properties of the samples were measured in broad frequency range and results show an increase in specific conductance and susceptance by adding Alq3 in PMMA. Changes in dielectric spectra caused by irradiation of the samples with LED lamps at different wavelengths were also recorded. The samples were examined by UV–Vis and Fourier transform infrared spectroscopy. The interaction between Alq3 and the polymer matrix was observed in the photoluminescence spectroscopy spectra. The doping of the PMMA with different concentrations of the Alq3 leads to the unique photodielectric properties of the resulting composite, and that is the main result of this study. Due to its interesting optical and photodielectric properties, PMMA/Alq3 film may find application in solar cells and optoelectronics.
Relationship between pore structure with residual pore and mechanical properties of expanded graphite nanocomposites at varying molding pressures
Authors: Goudarzi Rahimeh , Hashemi Motlagh Ghodratollah
Published: May 2021

The main challenges of developing expanded graphite (EG) composites are to improve the diffusion of polymer chains into EG pores and consequently to reduce the residual pore as defects in the final composites. In this paper, composites of unsaturated polyester (UP) resin containing 0.75 wt% EG are prepared at varying molding pressures of 1, 10, 20, and 30 bar. The EG particles are prepared at different exfoliation temperatures in the range of 700 to 900°C to have EGs with different porous structures. The scanning electron microscopy (SEM) micrographs show that residual pores are observed in the composites prepared at a low pressure of 1 bar. However, when the molding pressure increases, the number of the residual pores decreases and consequently the flexural properties improve. The highlighted improvements achieved by increasing the molding pressure from 1 to 30 bar are a decrease in the value of the residual pore from 23% to 3%, an increase in the flexural modulus from 1523 to 1744 MPa, and an increase in the flexural strength from 30.6 to 54.5 MPa. Interestingly, applying higher molding pressure affects the composites containing EGs with the highest degree of porosity, or rather larger pores, more remarkably.
Tribological properties and corrosion resistance of epoxy resin‐polytetrafluoroethylene bonded solid lubricating coating filled with flake aluminum
Authors: Li Guihua , Xu Haiyan , Wan Hongqi , Chen Lei , Ye Yinping , Ma Yanjun , An Yulong , Zhou Huidi , Chen Jianmin
Published: May 2021

The aims of this work are to prepare a novel epoxy resin‐polytetrafluoroethylene (expressed as EP/PTFE) bonded solid lubricating coating filled with flake aluminum. The focus is to study the effects of two different flake aluminum (floating type and non‐floating type) on the tribological performance and anti‐corrosion capability of the coating. A CSM friction tester was applied to evaluate the tribological performance of the coating. The electrochemical technique was applied to study the corrosion resistance of the coating. And the experimental results showed that both types of flake aluminum can ameliorate the tribological performance and anti‐corrosion properties of the EP/PTFE lubricating coating. Moreover, compared with floating flake aluminum, the incorporation of non‐floating flake aluminum significantly improved the tribological properties and corrosion resistance of the EP/PTFE coating due to its good dispersibility, greater enhancement effect on mechanical performance and stronger barrier properties.
High performance polylactic acid/thermoplastic polyurethane blends with in‐situ fibrillated morphology
Authors: Su Xiaolong , Jia Shikui , Cao Le , Yu Demei
Published: May 2021

As an environment‐friendly polyester, polylactic acid (PLA) shows great potential market value. While it still faces some obstacles in large‐scale practical application due to its brittleness. In this work, a novel strategy to improve the toughness of polylactic acid is developed. By adjusting processing temperature during the melt‐blending process, thermoplastic polyurethane/poly (D‐lactic) acid/poly (L‐lactic) acid (TPU/PDLA/PLLA) ternary blends with different morphology are obtained. The experimental results show that the TPU in ternary blends formed a fibrillated micro‐morphology, and the interfacial compatibility between the components is improved when the processing temperature is adjusted to 200°C. Under the synergistic action of in‐situ fibrillated TPU and stereocomplex (SC) crystals, the toughness of the ternary blends is improved significantly without sacrificing its own tensile strength. The maximum value of tensile strength, elongation at break, and fracture work of ternary blends are 61.9 MPa, 23.5%, and 1038.9 kJ/m3, respectively. In addition, the melt strength of ternary blends was significantly improved, which is a benefit to their processing application.
The HIF‐1/SNHG1/miR‐199a‐3p/TFAM axis explains tumor angiogenesis and metastasis under hypoxic conditions in breast cancer
Authors: Zuo Yonggang , Qu Changping , Tian Yanyan , Wen Yuqing , Xia Shuguan , Ma Mingde
Published: May 2021

Activation of hypoxia‐inducible factors (HIFs) as a result of intratumoral hypoxia modulates a cascade of molecular pathways thus leading to angiogenesis and metastasis in many solid tumors, including breast cancer (BC). In our paper, we report a regulatory axis of HIF‐1, SNHG1, miR‐199a‐3p, and mitochondrial transcription factor A (TFAM) involved in tumor angiogenesis and metastasis under hypoxic conditions in BC. The expression of SNHG1 was determined in human BC cells cultured in hypoxia (1% O2, 24 h) and normoxia (20% O2, 24 h). Cultured MDA‐MB‐231 cells were assayed for the proliferation, migration, invasion, angiogenesis in vitro by using EdU staining, transwell chamber assays, Matrigel‐based angiogenesis assays, tumorigenesis, and lung metastasis in vivo by using an orthotopic‐transplant model of human BC. Dual‐luciferase reporter assay, chromatin immunoprecipitation quantitative polymerase chain reaction assay, fluorescence in situ hybridization assay, RNA‐binding protein immunoprecipitation assay, and RNA pull‐down were performed to test interaction between HIF‐1 and SNHG1, SNHG1 and miR‐199a‐3p, miR‐199a‐3p and TFAM. SNHG1 was increased under hypoxic conditions at a HIF‐1‐dependent manner. SNHG1 knockdown tempered MDA‐MB‐231 cell proliferation, migration, invasion, angiogenesis, in vitro, tumorigenesis, and lung metastasis in vitro. SNHG1 was co‐expressed with miR‐199a‐3p and regulated the TFAM, a target gene of miR‐199a‐3p. SNHG1 increased the TFAM by binding with miR‐199a‐3p, thus promoting BC development and metastasis. These results support a regulatory axis consisting of HIF‐1, SNHG1, miR‐199a‐3p, and TFAM during BC development and metastasis under hypoxic conditions, providing an opportunity to develop targeted therapeutics for BC.
Improvement of protein production by engineering a novel antiapoptotic baculovirus vector to suppress the expression ofSf‐caspase‐1andTn‐caspase‐1
Authors: Zhang Xiaoyue , Zhao Kaixia , Lan Lan , Shi Na , Nan Hao , Shi Yanan , Xu Xiaodong , Chen Hongying
Published: May 2021

The baculovirus expression vector system (BEVS) is an attractive manufacturing platform for recombinant protein production in insect cells. However, baculovirus infection commonly induces host apoptosis in 3–4 days which would subsequently terminate the protein expression. Previous studies have proved that protein production by BEVS can be elevated in apoptosis‐suppressed insect cells. We also developed a baculovirus vector in our previous report to inhibit the apoptosis and improve protein production inSf9 cells. In this study, we designed five short hairpin RNA (shRNA) expression cassettes targeting a conserved region inSpodoptera frugiperda caspase‐1(Sf‐caspase‐1) andTrichoplusia ni caspase‐1(Tn‐caspase‐1), and found that introduction of C to T mutations within the stem region of the expression cassette was beneficial for the heterologous protein expression. One of the improved shRNA expression cassettes was knocked into a bacmid with the deletion of several nonessential genes. The novel baculovirus vector demonstrated the ability to suppress cell apoptosis in bothSf9 and High Five cells, and exhibited superior recombinant protein productivity of intracellularly expressed GFP and firefly luciferase and secreted glycoprotein OD‐Fc. The antiapoptotic baculovirus vector developed in this study could serve as a useful tool for the protein production in scientific research and pharmaceutical industries.