bluuebunny/crossref_metadata_2025 huggingface dataset:
On the fate of vacuum bubbles on matter backgrounds
Authors: Rakić A. , Simon D. , Adamek J. , Niemeyer J.
Published: June 2022

In this letter we discuss cosmological first order phase transitions with de Sitter bubbles nucleating on (inhomogeneous) matter backgrounds. The de Sitter bubble can be a toy model for an inflationary phase of universes like our own. Using the thin wall approximation and the Israel junction method we trace the classical evolution of the formed bubbles within a compound model. We first address homogeneous ambient space (FRW model) and already find that bubbles nucleated in a dust dominated background cannot expand. For an inhomogeneous dust background (LTB model) we describe cases with at least initially expanding bubbles. Yet, an ensuing passage of the bubble wall through ambient curvature inhomogeneities remains unnoticed for observers inside the bubble. Notable effects also for interior observers are found in the case of a rapid background phase transition in a FRW model.
Noether symmetric minisuperspace model of f(R) cosmology
Authors: Vakili B.
Published: June 2022

We study the metric f(R) cosmology using Noether symmetry approach by utilizing the behavior of the corresponding Lagrangian under infinitesimal generators of the desired symmetry. The existence of Noether symmetry of the cosmological f(R) minisuperspace helps us to find out the form of f(R) function for which such symmetry exist. It is shown that the resulting form for f(R) yields a power law expansion for the cosmic scale factor. We also show that in the corresponding Noether symmetric quantum model, the solutions to the Wheeler‐DeWitt equation can be expressed as a superposition of states of the form eiS. It is shown that in terms of such wavefunctions the classical trajectories can be recovered.
Gezielte Dehydratisierung als Synthesewerkzeug zur Herstellung eines neuen Na4SnS4‐Polymorphs: Kristallstruktur, Na+‐Leitfähigkeit und Einfluss der Sb‐Substitution
Authors: Hartmann Felix , Benkada Assma , Indris Sylvio , Poschmann Michael , Lühmann Henning , Duchstein Patrick , Zahn Dirk , Bensch Wolfgang
Published: June 2022

Wir präsentieren eine sehr bequeme Synthese und die Charakterisierung des neuen Thiostannats Na4SnS4 (
) durch gezielte thermische Zersetzung von Na4SnS4⋅14 H2O. Die Verbindung stellt ein neues, kinetisch stabilisiertes Polymorph von Na4SnS4 dar, welches sich beim Erhitzen in die thermodynamisch stabile Form (
) umwandelt. Durch thermische Ko‐Zersetzung von Mischungen mit Na3SbS4⋅9 H2O werden feste Lösungen Na4−xSn1−xSbxS4 (x=0.01, 0.10) erhalten, die isostrukturell zum neuen Polymorph (x=0) kristallisieren. Ergebnisse aus Röntgenbeugung, 119Sn NMR‐, 23Na NMR‐ und 119Sn‐Mößbauerspektroskopie zeigen, dass der Einbau von Sb5+ die Bindungen und die lokalen Strukturen erheblich beeinflusst. Durch Impedanzspektroskopie wird eine enorme Verbesserung der Ionenleitfähigkeit mit zunehmendem Sb‐Gehalt für die feste Lösung ermittelt (σ25 °C=2×10−3, 2×10−2 und 0.1 mS cm−2 1 für x=0, 0.01 und 0.10), welche um mehrere Größenordnungen höher sind als bei dem bekannten Na4SnS4‐Polymorph.
A Novel AgI‐DNA Rod Comprising a One‐Dimensional Array of 11 Silver Ions within a Double Helical Structure
Authors: Atsugi Takahiro , Ono Akira , Tasaka Miho , Eguchi Natsumi , Fujiwara Shoji , Kondo Jiro
Published: June 2022

DNA/RNA duplexes containing metal‐ion‐mediated base pairs (metallo‐base pairs) have potential applications in developing nucleic acid‐based nanodevices and genetic code expansion. Many metallo‐base pairs are formed within duplexes stabilized by Watson–Crick base pairs. Recently, the crystal structure of an AgI‐DNA nanowire with an uninterrupted one‐dimensional silver array was determined. Here, we present a new DNA helical wire, the “AgI‐DNA rod”, containing an uninterrupted array of 11 AgI ions. The AgI‐DNA rod consisted of only C‐AgI‐C, G‐AgI‐G, G‐AgI‐5‐bromouracil (BrU), and BrU‐AgI‐BrU metallo base pairs, with no Watson–Crick pairs. The AgI‐DNA rods were connected by non‐canonical G–G pairs in crystals. Notably, data from our absorbance, circular dichroism, nuclear magnetic resonance, and mass spectrometry analyses suggested that the AgI‐DNA rods formed in solution, as well as within crystals.
A Small Molecular Symmetric All‐Organic Lithium‐Ion Battery
Authors: Li Zengyu , Jia Qingqing , Chen Yuan , Fan Kun , Zhang Chenyang , Zhang Guoqun , Xu Ming , Mao Minglei , Ma Jing , Hu Wenping , Wang Chengliang
Published: June 2022

The structural designability of organic electrode materials makes them attractive for symmetric all‐organic batteries (SAOBs) by virtue of different plateaus. However, quite a few works have reported all‐organic batteries and it is still challenging to develop a high‐performance organic material for SAOBs. Herein, a small molecule, 2,3,7,8‐tetraaminophenazine‐1,4,6,9‐tetraone (TAPT), is reported for SAOBs. The rich C=O and C=N groups ensure the high capacity at both plateaus for C=O/C−O and C=N/C−N redox reactions, which are hence utilized as cathodic and anodic active centers respectively. Moreover, the presence of C=O, C=N and NH2 groups resulted in plentiful strong intermolecular interactions, leading to layered structures, insolubility and high stability. The rich functional groups also facilitated the chelation of N and O with Li cations and hence benefited the storage of Li cations. The electrochemical performances of TAPT‐based SAOBs outperformed all of the previously reported SAOBs.
Directed Dehydration as Synthetic Tool for Generation of a New Na4SnS4 Polymorph: Crystal Structure, Na+ Conductivity, and Influence of Sb‐Substitution
Authors: Hartmann Felix , Benkada Assma , Indris Sylvio , Poschmann Michael , Lühmann Henning , Duchstein Patrick , Zahn Dirk , Bensch Wolfgang
Published: June 2022

We present the convenient synthesis and characterization of the new ternary thiostannate Na4SnS4 (space group
) by directed removal of crystal water molecules from Na4SnS4⋅14 H2O. The compound represents a new kinetically stable polymorph of Na4SnS4, which is transformed into the known, thermodynamically stable form (space group
) at elevated temperatures. Thermal co‐decomposition of mixtures with Na3SbS4⋅9 H2O generates solid solution products Na4−xSn1−xSbxS4 (x=0.01, 0.10) isostructural to the new polymorph (x=0). Incorporation of Sb5+ affects the bonding and local structural situation noticeably evidenced by X‐ray diffraction, 119Sn and 23Na NMR, and 119Sn Mössbauer spectroscopy. Electrochemical impedance spectroscopy demonstrates an enormous improvement of the ionic conductivity with increasing Sb content for the solid solution (σ25°C=2×10−3, 2×10−2, and 0.1 mS cm−1 for x=0, 0.01, and 0.10), being several orders of magnitude higher than for the known Na4SnS4 polymorph.
CuI/AgI‐containing coordination compounds as advanced catalysts for selective oxidation of styrene to benzaldehyde
Authors: Zhao Zi‐Qiu , Geng Ying , Song Jiang‐Feng , Cui Xiao‐Bing
Published: June 2022

Four coordination compounds, [Cu(Hmthd)2Cl]n (1), [Cu3(mthd)2Br]n (2), [Ag(mthd)]n (3), and [Ag2(mthd)I]n (4) (Hmthd = 2‐mercapto‐5‐methyl‐1,3,4‐thiadiazole), were synthesized and characterized by inductively coupled plasma (ICP) elemental analyses, powder X‐ray diffraction (PXRD), and Fourier transform infrared (FT‐IR) spectroscopies. These resulting coordination compounds can act as efficient catalysts for the oxidation of olefins with tert‐butyl hydroperoxide (TBHP) as oxidant. Wherein, compound 2 performed extremely enhanced catalytic activity for oxidation of styrene at 80°C. Moreover, the addition of an appropriate amount of acid can promote the protonation of ligands and activate the two Ag‐containing catalysts to improve their catalytic efficiencies. Experimental results indicate that catalyst 2 has a low activation energy and excellent recycle catalytic property. Radical trap experiments were performed to verify that free radicals participate in the oxidation of styrene.
Hydrothermal aging of fire‐protective fabrics
Authors: Hoque Md. Saiful , Saha Ankit , Chung Hyun‐Joong , Dolez Patricia I.
Published: June 2022

Fire‐protective fabrics made from high‐performance fibers are available to provide protection from various hazardous conditions such as extreme heat and flame. However, these fabrics are often exposed to other deteriorating conditions, including moisture. It is a concern for user's safety as some high‐performance fibers are sensitive to hydrolysis. This study exposed eight fire‐protective fabrics corresponding to typical blends used in firefighter protective suit outer shells to accelerated hydrothermal aging. They were immersed in water at different temperatures between 60 and 95°C for up to 1200 h. After exposure to hydrothermal aging, some fabrics exhibited a significant loss in tensile strength without any morphological changes. Based on results from energy‐dispersive X‐ray spectroscopy and pH measurements of the aging water, the larger loss in strength experienced by the para‐aramid/PBI fiber‐based fabrics can be related to the high amount of sulfur measured in the PBI fibers, contributing to an acceleration of the para‐aramid fiber's hydrolysis in acidic conditions. Hydrothermal aging also appears to affect the water‐repellent finish of some fabrics. The study provides an insight into the effect of a generally ignored hazard, that is, moisture, on the long‐term performance of fire‐protective fabrics.
Insights into modulating the monastrol scaffold: Development of new pyrimidinones as Eg5 inhibitors with anticancer activity
Authors: Thabit Mohamed G. , Mostafa Amany S. , Selim Khalid B. , Elsayed Magda A. A. , Nasr Magda N. A.
Published: June 2022

Based on modulation of the monastrol scaffold, two series of pyrimidinone derivatives, 3a–e and 5a–k, were designed, synthesized, and investigated for their in vitro anticancer activity. Compound 5j exhibited the most potent cytotoxic activity against four cancer cell lines, including HCT‐116, HeLa, HEPG‐2, and MCF‐7, with IC50 values of 3.75–5.13 µM, while proving to be safe in the normal human cell line WI‐38, with a selectivity index value of 13.7 on HCT‐116 cells. Compounds 3d, 3e, and 5h–j were further assessed for their Eg5 inhibitory activity, where 3d and 5h–j showed high Eg5 inhibition with IC50 values of 28.48, 24.22, 18.90, and 12.89 µM, respectively, when compared to monastrol (IC50 = 14.89 µM). Cell cycle distribution of HCT‐116 cells monitored with compound 5j illustrated that the cell cycle was arrested at the G2/M phase, with considerable apoptotic effect. A molecular docking study was performed to investigate the mode of action of the synthesized anticancer agents as Eg5 inhibitors.
Characterization of caspase‐2 inhibitors based on specific sites of caspase‐2‐mediated proteolysis
Authors: Bresinsky Merlin , Strasser Jessica M. , Hubmann Alexander , Vallaster Bernadette , McCue William M. , Fuller Jessica , Singh Gurpreet , Nelson Kathryn M. , Cuellar Matthew E. , Finzel Barry C. , Ashe Karen H. , Walters Michael A. , Pockes Steffen
Published: June 2022

Since the discovery of the caspase‐2 (Casp2)‐mediated ∆tau314 cleavage product and its associated impact on tauopathies such as Alzheimer's disease, the design of selective Casp2 inhibitors has become a focus in medicinal chemistry research. In the search for new lead structures with respect to Casp2 selectivity and drug‐likeness, we have taken an approach by looking more closely at the specific sites of Casp2‐mediated proteolysis. Using seven selected protein cleavage sequences, we synthesized a peptide series of 53 novel molecules and studied them using in vitro pharmacology, molecular modeling, and crystallography. Regarding Casp2 selectivity, AcITV(Dab)D‐CHO (23) and AcITV(Dap)D‐CHO (26) demonstrated the best selectivity (1–6‐fold), although these trends were only moderate. However, some analogous tetrapeptides, most notably AcDKVD‐CHO (45), showed significantly increased Casp3 selectivities (>100‐fold). Tetra‐ and tripeptides display decreased or no Casp2 affinity, supporting the assumption that a motif of five amino acids is required for efficient Casp2 inhibition. Overall, the results provide a reasonable basis for the development of both selective Casp2 and Casp3 inhibitors.
A note on the existence and optimal control for mixed Volterra–Fredholm‐type integrodifferential dispersion system of third order
Authors: Patel Rohit , Vijayakumar V. , Nieto Juan J. , Jadon Shimpi Singh , Shukla Anurag
Published: June 2022

The optimal control problem consists of a performance index subject to a set of differential equations that describes the path of the control and state variables. The main aim of this article is to prove the existence and uniqueness of a mild solution, optimal control, and time‐optimal control of a mixed Volterra–Fredholm‐type third‐order dispersion system. By applying the strongly continuous semigroup theory and the Banach fixed‐point theorem, we prove the existence and uniqueness of the considered system. The optimal control results are proved by using Mazur's lemma, Gronwall's inequality, and the minimizing sequence technique. The discussion on the time‐optimal control of the third‐order dispersion system is also presented.
A mechanistic review on immunomodulatory effects of selective type two cannabinoid receptor β‐caryophyllene
Authors: Baradaran Rahimi Vafa , Askari Vahid Reza
Published: June 2022

β‐Caryophyllene (BCP) is a plant‐derived compound and occurs naturally in various foods and spices, including cinnamon, citrus, fruits, clove, curry, and pepper. BCP showed different pharmacological effects, such as antioxidant and antimicrobial properties. This article tried to gather updated knowledge of the anti‐inflammatory, antioxidant, and immunomodulatory effects of BCP and searched using various databases and appropriate keywords until April 2022. Several studies showed that the anti‐inflammatory effects of BCP are mainly provided through cannabinoid receptor 2 (CB2) receptor activation and the peroxisome proliferator‐activated receptor (PPAR) γ pathway. It has also been demonstrated that BCP suppresses both protein and mRNA expression levels of interleukin (IL)‐6 and reduces relevant proinflammatory cytokines but increases the anti‐inflammatory cytokine IL‐13. Previous results indicated that the antioxidant effects of β‐caryophyllene were suggested through different pathways, including activation of nuclear factor erythroid 2‐related factor‐2 (Nrf2)/heme oxygenase‐1 (HO‐1)/antioxidant axis and inhibition of the HMG‐CoA reductase activity, and oxidative stress biomarkers levels. Furthermore, various results showed immunomodulatory effects of BCP through inhibiting microglial cells, CD4+ and CD8+ T lymphocytes, modulated Th1/Treg immune balance through the activation of the CB2 receptor, and reducing mitogen‐activated protein kinases (p38MAPK) and NF‐kB activation and increased ionized calcium‐binding adaptor molecule‐1 (Iba‐1) and IL‐1β.
Transcriptomic analysis reveals mode of action of butyric acid supplementation in an intensified CHO cell fed‐batch process
Authors: Schulze Markus , Kumar Yadhu , Rattay Merle , Niemann Julia , Wijffels Rene H. , Martens Dirk E.
Published: June 2022

Process intensification is increasingly used in the mammalian biomanufacturing industry. The key driver of this trend is the need for more efficient and flexible production strategies to cope with the increased demand for biotherapeutics predicted in the next years. Therefore, such intensified production strategies should be designed, established, and characterized. We established a CHO cell process consisting of an intensified fed‐batch (iFB), which is inoculated by an N‐1 perfusion process that reaches high cell concentrations (100 × 106 c ml−1). We investigated the impact of butyric acid (BA) supplementation in this iFB process. Most prominently, higher cellular productivities of more than 33% were achieved, thus 3.5 g L−1 of immunoglobulin G (IgG) was produced in 6.5 days. Impacts on critical product quality attributes were small. To understand the biological mechanisms of BA in the iFB process, we performed a detailed transcriptomic analysis. Affected gene sets reflected concurrent inhibition of cell proliferation and impact on histone modification. These translate into subsequently enhanced mechanisms of protein biosynthesis: enriched regulation of transcription, messenger RNA processing and transport, ribosomal translation, and cellular trafficking of IgG intermediates. Furthermore, we identified mutual tackling points for optimization by gene engineering. The presented strategy can contribute to meet future requirements in the continuously demanding field of biotherapeutics production.
The effect of the informal sector on sustainable development: Evidence from developing countries
Authors: Sultana Nahid , Rahman Mohammad Mafizur , Khanam Rasheda
Published: June 2022

This study aims to explore the impact of the informal sector on the sustainability of development. A large panel data set of 50 developing countries that spans over 2010–2019 has been utilized to this end while the informal sector is evaluated in terms of working poverty. Selecting indicators from three dimensions of sustainability, that is, economy, society, and environment, this study has constructed three indices and combines those to construct a symptomatic composite index of sustainability. Both the short run and long run panel data models have been applied to empirically investigate the impact of informal economic activities on the sustainability of development. Economic growth, national expenditure, and economic freedom of countries are used as control variables in the models and the estimated outcomes are found to be robust in empirical investigations. The outcomes of the study imply that the informal sector plays a detrimental role in the sustainable development of developing countries while economic growth and economic freedom contribute positively. Therefore, the prescribed strategy is to reduce informality from business and other economic activities that limit the scope of the economies and to understand the domain through which interventions can be made to move to a more formal economy. Integration of informal business and SMEs into the formal sector and firm‐level awareness building in Corporate Social Responsibility can also be suggested to find a path towards sustainable development in addition to increased economic growth and enhanced economic opportunities of the developing countries.
The impact of entrepreneurship on the socio‐economic development of regions
Authors: Zhakupov Yerlan K. , Berzhanova Aigul M. , Mukhanova Gaini K. , Baimbetova Assel B. , Mamutova Katira K.
Published: June 2022

The relevance of the present article is explained by the need for a detailed study of the influence of medium and small business representatives on the economic indicators of the Republic of Kazakhstan. In this regard, this study is aimed at identifying or covering the development of entrepreneurship theory and establishing methodological approaches that allow assessing the impact of entrepreneurship on the socio‐economic development of regions. The leading method for the researched subject is a systems analysis, which allows comprehensively considering the regional economy as a complex multi‐component structure, performing in unstable global conditions. In addition, the following methods were used: logical analysis, comparative, economic, synthesis and deduction, classification, and mathematical statistics. The research results are presented in the format of figures and tables showing the contribution and influence of small and medium businesses on the economy of the Republic of Kazakhstan; in the course of the study, the authors covered the components that influence the successful development of the entrepreneurship macro‐environment; identified the factors that influence the socio‐economic development of the region. The study materials are of practical value for economists, teachers, and students in the field of economics, representatives of small and medium businesses.
A novel platform using homobifunctional hydrazide for enrichment and isolation of urinary circulating RNAs
Authors: Koo Bonhan , Kim Yunlim , Jang Yoon Ok , Liu Huifang , Kim Myoung Gyu , Lee Hyo Joo , Woo Myung Kyun , Kim Choung‐Soo , Shin Yong
Published: June 2022

Changes in specific circulating RNA (circRNA) expressions can serve as diagnostic noninvasive biomarkers for prostate cancer (PCa). However, there are still unmet needs, such as unclear types and roles of circRNAs, PCa detection in benign prostatic hyperplasia (BPH) by unstandardized methods, and limitations of sample volume capacity and low circRNA concentrations. This study reports a simple and rapid circRNA enrichment and isolation technique named “HAZIS‐CirR” for the analysis of urinary circRNAs. The method utilizes homobifunctional hydrazides with amine‐modified zeolite and polyvinylidene fluoride (PVDF) syringe filtration for combining electrostatic and covalent coupling and size‐based filtration, and it offers instrument‐free isolation of circRNAs in 20 min without volume limitation, thermoregulation, and lysis. HAZIS‐CirR has high capture efficiency (82.03%–92.38%) and a 10‐fold more sensitive detection limit (20 fM) than before enrichment (200 fM). The clinical utility of HAZIS‐CirR is confirmed by analyzing circulating mRNAs and circulating miRNAs in 89 urine samples. Furthermore, three miRNA panels that differentiate PCa from BPH and control, PCa from control, and BPH from control, respectively, are established by comparing miRNA levels. HAZIS‐CirR will be used as an optimal and established method for the enrichment and isolation of circRNAs as diagnostic, prognostic, and predictive biomarkers in human cancers.
Epi‐immunotherapy for cancers: rationales of epi‐drugs in combination with immunotherapy and advances in clinical trials
Authors: Xu Yang , Li Ping , Liu Yang , Xin Dijia , Lei Wen , Liang Aibin , Han Weidong , Qian Wenbin
Published: June 2022

Over the last two decades, several epi‐drugs, immune checkpoint inhibitors (ICIs) and adoptive cell therapies have received clinical approval for use in certain types of cancer. However, monotherapy with epi‐drugs or ICIs has shown limited efficacy in most cancer patients. Epigenetic agents have been shown to regulate the crosstalk between the tumor and host immunity to alleviate immune evasion, suggesting that epi‐drugs can potentially synergize with immunotherapy. In this review, we discuss recent insights into the rationales of incorporating epigenetic therapy into immunotherapy, called epi‐immunotherapy, and focus on an update of current clinical trials in both hematological and solid malignancies. Furthermore, we outline the future challenges and strategies in the field of cancer epi‐immunotherapy.
Evaluating students' perception of Scrum through a learning game
Authors: Rodriguez Guillermo , Vidal Santiago , Marcos Claudia , Martínez Saucedo Ana C.
Published: June 2022

Games for learning help students and professionals to incorporate new knowledge through a playful experience. With the popularization of virtual education (partially due to COVID‐19), there is a need for new tools that complement virtual educational environments. To deal with this need, we present Scrum Game, a mobile application game that aims to support the Scrum software methodology teaching and training. Scrum Game offers 42 activities grouped in levels with specific learning goals. This paper reports on a controlled experiment that evaluates Scrum Game in a course with more than 160 students. We assessed Scrum Game's effectiveness in terms of (i) user performance (i.e., students' marks and number of levels/activities completed) and (ii) user experience (i.e., usability). We found that students who used Scrum Game outperformed those who did not use it. We also found that students think that Scrum Game exhibits an enjoyable user experience.
Clinical characteristics, risk factors and outcomes of cancer patients withCOVID‐19: A population‐based study
Authors: Zhou Jiandong , Lakhani Ishan , Chou Oscar , Leung Keith Sai Kit , Lee Teddy Tai Loy , Wong Michelle Vangi , Li Zhen , Wai Abraham Ka Chung , Chang Carlin , Wong Ian Chi Kei , Zhang Qingpeng , Tse Gary , Cheung Bernard Man Yung
Published: June 2022

Introduction

Cancer patients may be susceptible to poorer outcomes in COVID‐19 infection owing to the immunosuppressant effect of chemotherapy/radiotherapy and cancer growth, along with the potential for nosocomial transmission due to frequent hospital admissions.

Methods

This was a population‐based retrospective cohort study of COVID‐19 patients who presented to Hong Kong public hospitals between 1 January 2020 and 8 December 2020. The primary outcome was a composite endpoint of requirement for intubation, ICU admission and 30‐day mortality.

Results

The following study consisted of 6089 COVID‐19 patients (median age 45.9 [27.8.1–62.7] years; 50% male), of which 142 were cancer subjects. COVID‐19 cancer patients were older at baseline and tended to present with a higher frequency of comorbidities, including diabetes mellitus, hypertension, chronic obstructive pulmonary disease, ischemic heart disease, ventricular tachycardia/fibrillation and gastrointestinal bleeding (p < 0.05). These subjects also likewise tended to present with higher serum levels of inflammatory markers, including D‐dimer, lactate dehydrogenase, high sensitivity troponin‐I and C‐reactive protein. Multivariate Cox regression showed that any type of cancer presented with an almost four‐fold increased risk of the primary outcome (HR: 3.77; 95% CI: 1.63–8.72;p < 0.002) after adjusting for significant demographics, Charlson comorbidity index, number of comorbidities, past comorbidities and medication history. This association remained significant when assessing those with colorectal (HR: 5.07; 95% CI: 1.50–17.17;p < 0.009) and gastrointestinal malignancies (HR: 3.79; 95% CI: 1.12–12.88;p < 0.03), but not with lung, genitourinary, or breast malignancies, relative to their respective cancer‐free COVID‐19 counterparts.

Conclusions

COVID‐19 cancer patients are associated with a significantly higher risk of intubation, ICU admission and/or mortality.
Application of exosomes for the alleviation of COVID‐19‐related pathologies
Authors: Rezabakhsh Aysa , Mahdipour Mahdi , Nourazarian Alireza , Habibollahi Paria , Sokullu Emel , Avci Çigir Biray , Rahbarghazi Reza
Published: June 2022

The pandemic of COVID‐19 caused worldwide concern. Due to the lack of appropriate medications and the inefficiency of commercially available vaccines, lots of efforts are being made to develop de novo therapeutic modalities. Besides this, the possibility of several genetic mutations in the viral genome has led to the generation of resistant strains such as Omicron against neutralizing antibodies and vaccines, leading to worsening public health status. Exosomes (Exo), nanosized vesicles, possess several therapeutic properties that participate in intercellular communication. The discovery and application of Exo in regenerative medicine have paved the way for the alleviation of several pathologies. These nanosized particles act as natural bioshuttles and transfer several biomolecules and anti‐inflammatory cytokines. To date, several approaches are available for the administration of Exo into the targeted site inside the body, although the establishment of standard administration routes remains unclear. As severe acute respiratory syndrome coronavirus 2 primarily affects the respiratory system, we here tried to highlight the transplantation of Exo in the alleviation of COVID‐19 pathologies.
One‐Step Preparation of Cell‐Free ATP Regeneration Module Based on Non‐Oxidative Glycolysis Using Thermophilic Enzymes
Authors: Suryatin Alim Gladwin , Okano Kenji , Honda Kohsuke
Published: June 2022

Adenosine triphosphate (ATP) is an essential cofactor for energy‐dependent enzymatic reactions that occur duringin vitrobiochemical conversion. Recently, an enzyme cascade based on non‐oxidative glycolysis, which uses starch and orthophosphate as energy and phosphate sources, respectively, for the regeneration of ATP from adenosine diphosphate, has been developed (Wei et al.,ChemCatChem2018,10, 5597–5601). However, the 12 enzymes required for this system hampered its practical usability and further testing potential. Here, we addressed this issue by constructing co‐expression vectors for the simultaneous gene expression of the 12 enzymes in a single expression strain. All enzymes were sourced from (hyper)thermophiles, which enabled a one‐step purification via a heat‐treatment process. We showed that the combination of the two enabled the ATP regeneration system to function in a single recombinantEscherichia colistrain. Additionally, this work provides a strategy to rationally design and control proteins expression levels in the co‐expression vectors.
Conjugation of a Toll‐Like Receptor Agonist to Glycans of an HIV Native‐Like Envelope Trimer Preserves Neutralization Epitopes
Authors: Li Zeshi , Derking Ronald , Lee Wen‐Hsin , Bosman Gerlof P. , Ward Andrew B. , Sanders Rogier W. , Boons Geert‐Jan
Published: June 2022

Small molecule adjuvants are attractive for enhancing broad protection and durability of immune responses elicited by subunit vaccines. Covalent attachment of an adjuvant to an immunogen is particularly attractive because it simultaneously delivers both entities to antigen presenting cells resulting in more efficient immune activation. There is, however, a lack of methods to conjugate small molecule immune potentiators to viral glycoprotein immunogens without compromising epitope integrity. We describe herein a one‐step enzymatic conjugation approach for the covalent attachment of small molecule adjuvants to N‐linked glycans of viral glycoproteins. It involves the attachment of an immune potentiator to CMP‐Neu5AcN3 by Cu(I)‐catalyzed azide‐alkyne 1,3‐cycloaddition followed by sialyltransferase‐mediated transfer to N‐glycans of a viral glycoprotein. The method was employed to modify a native‐like HIV envelope trimer with a Toll‐like receptor 7/8 agonist. The modification did not compromise Env‐trimer recognition by several broadly neutralization antibodies. Electron microscopy confirmed structural integrity of the modified immunogen.
Enhancing Cellulose‐Based Separator with Polyethyleneimine and Polyvinylidene Fluoride‐Hexafluoropropylene Interpenetrated 3D Network for Lithium Metal Batteries
Authors: Yao Xin , Song Xiaohui , Zhang Fan , Ma Jian , Jiang Hao , Wang Lulu , Liu Yongchao , Huixiang Ang Edison , Xiang Hongfa
Published: June 2022

Aside from the electrolyte, a separator is another important component in lithium‐based batteries that has a direct impact on the safety feature and electrochemical performances. To overcome the thermal shrinkage and poor electrolyte affinity of commonly used polyolefin separators, cellulose‐based separators are appealing due to their abundant polar functional groups, thermal stability, and environmental friendliness, especially for large‐sized and high‐energy‐density batteries. Herein, a porous three‐dimensional (3D) network of polymer cellulose‐based separator (denoted as PIC) modified with polyethyleneimine (PEI) and polyvinylidene fluoride‐hexafluoropropylene (PVDF‐HFP) was prepared using a non‐solvent induced phase separation approach. The lithium metal batteries consisting of a PIC separator can deliver a specific capacity of up to 114 mAh g−1 even at a high C‐rate of 8 C (1.36 A g−1) after 300 cycles. Such superior performances of the lithium metal batteries can be attributed to the good wetting ability (390 % electrolyte absorption) and high ionic conductivity (0.754 mS cm−1) of the as‐prepared PIC separator. More importantly, the introduction of polyethyleneimine as a cross‐linking agent significantly improves the mechanical strength of the separator, promotes the uniform deposition of lithium, and compatibility with high voltage (4.4 V) cathode materials LiNi0.8Mn0.1Co0.1O2. This work demonstrates a new strategy for the separator design for high‐performance lithium metal battery applications.
The Use of Bridging Ligand Substituents to Bias the Population of Localized and Delocalized Mixed‐Valence Conformers in Solution
Authors: Safari Parvin , Gückel Simon , Gluyas Josef B. G. , Moggach Stephen A. , Kaupp Martin , Low Paul J.
Published: June 2022

The electronic structure and associated spectroscopic properties of ligand‐bridged, bimetallic ‘mixed‐valence’ complexes of the general form {M}(μ‐B){M+} are dictated by the electronic couplings, and hence orbital overlaps, between the metal centers mediated by the bridge. In the case of complexes such as [{Cp*(dppe)Ru}(μ‐C≡CC6H4C≡C){Ru(dppe)Cp*}]+, the low barrier to rotation of the half‐sandwich metal fragments and the arylene bridge around the acetylene moieties results in population of many energy minima across the conformational energy landscape. Since orbital overlap is also sensitive to the particular mutual orientations of the metal fragment(s) and arylene bridge through a Karplus‐like relationship, the different members of the population range exemplify electronic structures ranging from strongly localized (weakly coupled Robin‐Day Class II) to completely delocalized (Robin‐Day Class III). Here, we use electronic structure calculations with the hybrid density functional BLYP35‐D3 and a continuum solvent model in combination with UV‐vis‐NIR and IR spectroelectrochemical studies to show that the conformational population in complexes [{Cp*(dppe)Ru}(μ‐C≡CArC≡C){Ru(dppe)Cp*]+, and hence the dominant electronic structure, can be biased through the steric and electronic properties of the diethynylarylene (Ar) moiety (Ar=1,4‐C6H4, 1,4‐C6F4, 1,4‐C6H2‐2,5‐Me2, 1,4‐C6H2‐2,5‐(CF3)2, 1,4‐C6H2‐2,5‐iPr2).
Radical/Iminium Domino Strategy (RIDS) for Rapid Construction of Sterically Congested γ‐Lactam‐Based Multiheterocycles
Authors: Ishida Yuto , Nishikata Takashi
Published: June 2022

Cu‐Catalyzed radical/iminium domino strategy (RIDS) for the efficient synthesis of quaternary‐carbon‐containing γ‐lactam‐based multiheterocyclic structures from α‐bromocarboxamides is reported. This domino reaction strategy enables the construction of multiheterocycles in one step. Mechanistic studies showed that two catalytically generated iminiums are likely to be key intermediates in the catalytic cycle. The developed method can be used in a chemoselective manner to produce multicyclic products in the reaction with ketones possessing two different carbonyls.
Electron‐Rich EDOT Linkers in Tetracationic bis‐Triarylborane Chromophores: Influence on Water Stability, Biomacromolecule Sensing, and Photoinduced Cytotoxicity
Authors: Ferger Matthias , Roger Chantal , Köster Eva , Rauch Florian , Lorenzen Sabine , Krummenacher Ivo , Friedrich Alexandra , Košćak Marta , Nestić Davor , Braunschweig Holger , Lambert Christoph , Piantanida Ivo , Marder Todd B.
Published: June 2022

Three novel tetracationic bis‐triarylboranes with 3,4‐ethylenedioxythiophene (EDOT) linkers, and their neutral precursors, showed significant red‐shifted absorption and emission compared to their thiophene‐containing analogues, with one of the EDOT‐derivatives emitting in the NIR region. Only the EDOT‐linked trixylylborane tetracation was stable in aqueous solution, indicating that direct attachment of a thiophene or even 3‐methylthiophene to the boron atom is insufficient to provide hydrolytic stability in aqueous solution. Further comparative analysis of the EDOT‐linked trixylylborane tetracation and its bis‐thiophene analogue revealed efficient photo‐induced singlet oxygen production, with the consequent biological implications. Thus, both analogues bind strongly to ds‐DNA and BSA, very efficiently enter living human cells, accumulate in several different cytoplasmic organelles with no toxic effect but, under intense visible light irradiation, they exhibit almost instantaneous and very strong cytotoxic effects, presumably attributed to singlet oxygen production. Thus, both compounds are intriguing theranostic agents, whose intracellular and probably intra‐tissue location can be monitored by strong fluorescence, allowing switching on of the strong bioactivity by well‐focused visible light.
The implications of 3D‐printed membranes for water and wastewater treatment and resource recovery
Authors: Aghaei Amir , Firouzjaei Mostafa Dadashi , Karami Pooria , Aktij Sadegh Aghapour , Elliott Mark , Mansourpanah Yaghoub , Rahimpour Ahmad , B. P. Soares João , Sadrzadeh Mohtada
Published: June 2022

It is widely acknowledged that three‐dimensional (3D) printing or additive manufacturing will revolutionize many industries. However, the broad implications of 3D printing on water treatment membranes are not appreciated. 3D printing will transform the traditional membrane fabrication methods, reducing costs and industrial waste from manufacturing processes, with substantial benefits to treatment performance. In particular, 3D printing provides a high potential for radical decentralization. Remote communities, hospitality resorts, military bases, and oil and gas extraction operations could significantly benefit from the on‐site fabrication of membrane units tunable to their specific wastewater challenges. Acute drinking water contamination events, like those associated with toxic by‐products from algal blooms, chemical spills, forest fires, and extreme weather, cause adverse health effects on humans and shutdowns of piped water supply. 3D printing of customized membranes provides an opportunity for a fast response to such disastrous events. These membranes could be ready for installation within hours, with the vendor's role more akin to a software company installing a patch than the traditional approach, with major considerations for hardware availability, timeline, and supply chain. Despite these clear and potentially transformative advantages, 3D printing of membranes is not a panacea; countless aspects need to be taken into consideration for the successful implementation of this emerging technology. The full deployment of 3D‐printed membranes in water and wastewater treatment can be achieved by extending the variety of printable materials, improving the speed and resolution of printing, creating nanoscale pores, reducing the fabrication costs, and improving the mechanical properties of the resulting membranes.
Ionic Liquid‐Assisted Crystallization and Defect Passivation for Efficient Perovskite Solar Cells with Enhanced Open‐Circuit Voltage
Authors: Hu Ping , Huang Shiqi , Guo Minghuang , Li Yafeng , Wei Mingdeng
Published: June 2022

Perovskite materials have demonstrated many excellent properties in next‐generation photovoltaic devices, but the intrinsic defects and the quality of perovskite film still limit the performance and stability of PSCs. Here, 1,3‐dimethylimidazolium iodide (DMII) ionic liquid was employed as an additive to passivate the various defects and produce the high‐quality perovskite film with enlarged grain sizes. DMII could act as an “ionic stabilizer” for passivating the point defects including the vacancies defects of organic cations and halogen anions of perovskite. At the same time, the extra problematic PbI2 on surfaces and at grain boundaries of the perovskite film could also be reacted by DMII, leading to the reduction of recombination centers and trap states. On the other hand, the DMII ionic liquid with a “Ostwald ripening effect” could retard the crystallization process of perovskite crystals and yield better film quality with higher crystallinity, smoother morphology and larger grains. As a result, the optimal device achieved a champion power conversion efficiency (PCE) of 20.4 %. Particularly, the modified devices demonstrated a significant elevation in open‐circuit voltage from 1.03 to 1.10 V. The hydrophobicity of perovskite films modified by DMII was enhanced and the un‐encapsulated DMII devices retained 91 % of their initial PCE after aging 60 days under 15±5 % relative humidity.
Hammett Correlation in Competing Fragmentations of Ionized 2‐Substituted Benzanilides Generated by Electron Ionization Mass Spectrometry
Authors: Fenwick Nathan W. , Telford Richard , Martin William H. C. , Bowen Richard D.
Published: June 2022

A good Hammett correlation has been found between the two principal fragmentations of four series of radical‐cations generated by electron ionization of 2‐substituted benzanilides of general structure XC6H4NHCOC6H4Y [X=CH3O, Cl, Br or I; Y=H, F, Cl, Br, I, CH3, OCH3, CF3or NO2in the 3 or 4 position]. When X is electron‐donating, with a negative substituent constant, σ, simple cleavage of these ionic species to form a substituted benzoyl cation, [YC6H4CO]+, is favoured. In contrast, when Y is electron withdrawing, with a positive σ constant, rearrangement leading to elimination of X⋅ by a proximity effect to form a protonated 2‐arylbenzoxazole competes more effectively. Reproducible trends are observed in the derived reaction constant, ρ, which declines on progressing from X=CH3O through Cl and Br to I. These trends establish that the mechanism of the proximity effect involves donation of electron density from the C6H4Y ring and is not materially altered by varying X.
Sb‐Substituted Cs2AgBiBr6—As Much As It Could Be?—Influence of Synthesis Methods on Sb‐Substitution Level in Cs2AgBiBr6
Authors: Yoon Songhak , Fett Bastian , Frebel Alexander , Kroisl Sina , Herbig Bettina , Widenmeyer Marc , Balke Benjamin , Sextl Gerhard , Mandel Karl , Weidenkaff Anke
Published: June 2022

Sb‐substituted Cs2AgBiBr6 single crystals and powders are synthesized by various wet‐chemical routes as well as by solvent‐free mechanochemical synthesis. Phase purity and resulting optical properties of differently synthesized Sb‐substituted Cs2AgBiBr6 absorbers are investigated and compared. X‐ray diffraction confirms that Sb substitution results in an apparent single‐phase formation with a unit cell shrinkage up to a certain substitution limit, which varies depending on the synthesis routes. Questions about the phase identification determined by X‐ray diffraction are raised and thoroughly investigated by Raman spectroscopy. UV–vis spectroscopy reveals that Sb3+ substitution induces a reduction in the optical bandgap of Cs2AgBiBr6, whereas octahedral factor calculations provide that SbBr6 octahedra can be hardly stable in a Cs2AgBiBr6 double perovskite. The experimental results of the occurrence and evolution of Raman bands and theoretical calculations of the structural stability of SbBr6 octahedra in Cs2AgBiBr6 unambiguously raise doubts about the Sb‐substitution feasibility in Cs2AgBiBr6, and a general substitution strategy in Cs2AgBiBr6 is discussed.
Vacuum‐Assisted Laminating Preparation for Carbon Film Electrode in Perovskite Solar Cells
Authors: Duan Qiuyue , Chen Lin , Shu Chengrun , Zhang Xinxin , Ku Zhiliang , Zhong Jie , Li Wei , Peng Yong , Huang Fuzhi , Cheng Yi-bing , Xiao Junyan
Published: June 2022

As an alternative to an evaporated metal top electrode, the carbon film electrode has been successfully applied to small‐area rigid and flexible perovskite solar cells by a pressing transfer method. However, the plate‐to‐plate laminating process for the carbon film electrodes deposition has some shortcomings, such as the uneven and uncertain actual loaded pressure on device. Herein, the carbon film‐based top electrode is laminated onto the perovskite device via a vacuum‐assisted pressing technique with an automatic solar panel laminator. Compared with manual and pneumatic plate pressing, the vacuum laminating process can reduce the roughness of the carbon film and increase the contact area under relatively low working pressure. Consequently, the perovskite solar cells with vacuum laminated carbon electrodes can achieve a relatively high efficiency of 18.3% and exhibit application prospect for reproducible mass fabrication.
Self‐Discharge Voltage Drop Estimation Method Based on Improved Gaussian Process Regression
Authors: Liu Zhengyu , Huang Wei , Wang Keqing , Xie Juan , He Huijuan
Published: June 2022

The self‐discharge rate is an important index for determining the quality of a lithium‐ion battery. Currently, the self‐discharge of a battery is mainly determined through experimental tests, which are time‐consuming and laborious. To provide a fast and reliable self‐discharge rate estimation, an improved Gaussian process regression (GPR) model based on the charge–discharge curve is proposed to estimate the self‐discharge voltage drop. In this method, the voltage features extracted from the charge–discharge curve are used as the input of the GPR model. These features reflect the self‐discharge performance of batteries from different angles. The gray correlation analysis method is used to analyze the degree of correlation between the selected features and self‐discharge voltage drop. Furthermore, a kernel function suitable for voltage drop estimation is selected. Simultaneously, the GPR model is adjusted, and the particle swarm optimization algorithm is used to optimize the superparameters of the GPR model to improve the estimation accuracy of the self‐discharge voltage drop of the model. The self‐discharge voltage drop data from the experiment are used to demonstrate the estimation effect of the proposed method. The results reveal that this method is reliable and has a high estimation accuracy for the self‐discharge voltage drop.
Thermal performances evaluation of a flat‐plate solar collector using microencapsulated phase‐change slurry as heat transfer medium
Authors: Ran Fengming , Zhang Huan , Xu Changlu , Fang Guiyin
Published: June 2022

Microencapsulated phase‐change slurry (MPCS) is composed of microencapsulation phase‐change materials (MPCM) and carrying medium (water), which can be used for heat transfer and thermal energy storage. Some theoretical and experimental works have been proposed on the thermal energy storage and flow performance of MPCS. However, there are few studies on the performances of MPCS in the thermal energy devices (eg, solar collector). In present work, the numerical model of a flat‐plate solar collector with MPCS as the thermal energy storage fluid was established. Then, the effects of mass fraction of MPCS, latent heat and solar radiation on thermal efficiency, and pumping power consumption of the solar collector model were studied. The simulations indicated that the thermal efficiency of the solar collector model was positively correlated with the mass fraction and latent heat, but decreased with the increase of solar radiation. When the inlet flow rate, mass concentration, latent heat and solar radiation of the MPCS were set to 0.01 m/s, 5.90%, 88 kJ/kg and 300 W/m2, respectively, thermal efficiency of the solar collector model was the largest, which was 0.711. Moreover, the pumping power consumption was mainly affected by inlet flow rate and mass fraction of MPCS.
Post hoc power is not informative
Authors: Heinsberg Lacey W. , Weeks Daniel E.
Published: June 2022

Post hoc power estimates are often requested by reviewers and/or performed by researchers after a study has been conducted. The purpose of this commentary is to provide a heuristic explanation of why post hoc power should not be used. To illustrate our point, we provide a detailed simulation study of two essentially identical research experiments hypothetically conducted in parallel at two separate universities. The simulation demonstrates that post hoc power calculations are misleading and simply not informative for data interpretation. As such, we encourage authors and peer‐reviewers to avoid using or requesting post hoc power calculations.