bluuebunny/crossref_metadata_2025 huggingface dataset:
In Situ Spontaneous Fabrication of Tough and Stretchable Polyurethane‐Polyethyleneimine Hydrogels Selectively Triggered by CO2
Authors: Song Minju , Choi Kangho , Choi Inseong , Han Soo‐Kyung , Ryu Young‐Hyun , Oh Do‐Hyun , Ahn Guk‐Young , Choi Sung‐Wook
Published: September 2022

CO2‐triggered in situ hydrogels is developed from waterborne poly(ε‐caprolactone)‐based polyurethane (PU) dispersion and aqueous polyethyleneimine (PEI) solution without any other chemicals and apparatus (e.g., UV light). In the approach, nontoxic CO2 in air is used as a selective trigger for the hydrogel formation. CO2 adsorption onto PEI results in the formation of ammonium cations in PEI and the subsequent multiple ionic crosslinking between PU and PEI chains. Besides the amount of CO2 in air, the rate of hydrogel formation can be controlled by NaHCO3 in the PU–PEI mixture, which serves as a CO2 supplier. The PU hydrogels exhibit tough and stretchable properties with high tensile strength (2.05 MPa) and elongation at break (438.24%), as well as biocompatibility and biodegradability. In addition, the PU hydrogels exhibit high adhesion strength on skin and injectability due to the in situ formation. It is believed that these PU hydrogels have the ideal features for various future applications, such as tissue adhesion barriers, wound dressing, artificial skin, and injectable fillers.
Therapeutic potential of the novel Bcl‐2/Bcl‐XL dual inhibitor, APG1252, alone or in combination against non‐small cell lung cancer
Authors: Qian Luxi , Vallega Karin A. , Yao Weilong , Wang Dongsheng , Zhai Yifan , He Xia , Sun Shi‐Yong
Published: September 2022

Targeting the induction of apoptosis is a promising cancer therapeutic strategy with some clinical success. This study focused on evaluating the therapeutic efficacy of the novel Bcl‐2/Bcl‐XL dual inhibitor, APG1252‐M1 (also named APG‐1244; an in vivo active metabolite of APG1252 or pelcitoclax), as a single agent or in combination, against non‐small cell lung cancer (NSCLC) cells. APG1252‐M1 effectively decreased the survival of some NSCLC cell lines expressing low levels of Mcl‐1 and induced apoptosis. Overexpression of ectopic Mcl‐1 in the sensitive cells substantially compromised APG1252‐M1's cell‐killing effects, whereas inhibition of Mcl‐1 greatly sensitized insensitive cell lines to APG1252‐M1, indicating the critical role of Mcl‐1 levels in impacting cell response to APG1252‐M1. Moreover, APG1252‐M1, when combined with the third generation epidermal growth factor receptor (EGFR) inhibitor, osimertinib, synergistically decreased the survival of EGFR‐mutant NSCLC cell lines including those resistant to osimertinib with enhanced induction of apoptosis and abrogated emergence of acquired resistance to osimertinib. Importantly, the combination was effective in inhibiting the growth of osimertinib‐resistant tumors in vivo. Collectively, these results demonstrate the efficacy of APG1252 alone or in combination against human NSCLC cells.
New iterative methods for nonlinear operators as concerns convex programming applicable in differential problems, image deblurring, and signal recovering problems
Authors: Chairatsiripong Chonjaroen , Yambangwai Damrongsak , Thianwan Tanakit
Published: September 2022

In this paper, using sunny nonexpansive retractions, which are different from the metric projection in Banach spaces, a new type of study regarding the iterative methods in view of two quasi‐nonexpansive nonself mappings is presented. We also give the convergence analysis for the proposed method in the background of uniformly convex Banach spaces. Moreover, we apply our results to find solutions of common zeros of accretive operators, convexly constrained least square problems, and convex minimization problems. Furthermore, we also discuss novel applications of these methods to differential problems, image deblurring, and signal recovering problems.
Phenotyping suicidal ideation and behavior: Comparing clinical characteristics and future suicide attempts between suicidal subtypes in two clinical samples
Authors: Spangenberg Lena , Friedrich Michael , Forkmann Thomas , Hallensleben Nina , Schönfelder Antje , Rath Dajana , Paashaus Laura , Teismann Tobias , Glaesmer Heide
Published: September 2022

Objectives

To further validate the concept of suicidal subtypes distinguished by indicators of suicidal thinking and behavior with regard to clinical characteristics and past and future suicide attempts.

Methods

Psychiatric inpatients were assessed (study 1: ecological momentary assessments in 74 depressed inpatients with suicidal ideation; study 2: clinical assessments in 224 inpatients after a suicide attempt and over a 12‐month follow‐up period). Subtypes were identified using latent profile analysis (based on indicators of real‐time suicide ideation) and latent class analysis (based on features of past suicide ideation and suicide attempt characteristics). Comparisons between subtypes included clinical characteristics (depression, suicidal ideation, trait impulsivity, childhood trauma) as well as past (study 1) and future (study 2) suicide attempts.

Results

Suicidal subtypes emerged that are characterized by suicidal ideation means and stability and features of past suicidal behavior (four in study 1, three in study 2). The subtypes differed in terms of depression/suicidal ideation, but not in terms of trait impulsivity/childhood trauma. Although not significant, the subtypes “high‐stable” and “low‐moderate stable” reported multiple re‐attempts more frequently during follow‐up than the “low‐stable” subtype in study 2.

Conclusion

Differences in clinical variables (and by trend in future suicide attempts) clearly point to the clinical relevance of suicidal subtypes (with variability of suicidal thoughts playing a particularly important role).
The relationship between pre‐ and postprostatectomy measures of pelvic floor muscle function and development of early incontinence after surgery
Authors: Stafford Ryan E. , Doorbar‐Baptist Stuart , Hodges Paul W.
Published: September 2022

Aims

The aim of this study is to investigate (i) whether pelvic floor muscle (PFM) shortening can be enhanced by provision of training focused on striated urethral sphincter (SUS) with feedback before prostatectomy, (ii) whether PFM shortening during voluntary efforts and coughing before and after prostatectomy differs between men who do and do not report symptoms of urinary incontinence 1 month after prostatectomy, and (iii) the relationship between severity of incontinence after prostatectomy and features of pelvic floor function (muscle shortening) and urethral length before and after prostatectomy.

Methods

Sixty men referred for preoperative PFM training before radical prostatectomy participated. The International Continence Society Male Short Form questionnaire was used to quantify continence status. Transperineal ultrasound (US) imaging was used to record pelvic displacements related to activation of striated urethral sphincter, bulbocavernosus (BC) and puborectalis muscles during cough, “natural” voluntary contraction following pamphlet instruction, and trained voluntary contraction after formal physiotherapist instruction including US feedback.

Results

Pelvic floor displacements following training differed between continent and incontinent men; continent participants demonstrated increased SUS shortening after training (compared with “natural”), but no difference was observed between trained and “natural” contractions for incontinent participants. Motion at ano‐rectal junction during cough was reduced following surgery, but voluntary and involuntary activation of SUS or BC was not consistently affected by surgery.

Conclusions

Participants' capacity to improve function of the SUS with training appears related to postprostatectomy continence outcome.
SUFU white paper on overactive bladder anticholinergic medications and dementia risk
Authors: Zillioux Jacqueline , Welk Blayne , Suskind Anne M. , Gormley E. Ann , Goldman Howard B.
Published: September 2022

Aims

Anticholinergic medications are widely used in the treatment of overactive bladder (OAB), as well as for short‐term treatment of bladder symptoms following a variety of urologic surgeries. Mounting evidence points to an association between anticholinergic medications and the increased risk of incident dementia. The Society for Urodynamics, Female Pelvic Medicine, and Urogenital Reconstruction (SUFU) thus convened a committee of subject experts to contextualize the current understanding of the cognitive risks of anticholinergic medications in the urologic patient population and to provide practical clinical guidance on this subject.

Methods

Statements are based on an expert literature review and the committee's opinion. The document has been reviewed and approved by the SUFU board.

Results

Chronic use (>3 months) of OAB anticholinergic medications is likely associated with an increased risk of new‐onset dementia. Short‐term (<4 weeks) use of most OAB anticholinergic medications is likely safe in most individuals. Clinicians should consider potential cognitive risks in all patient populations when prescribing OAB anticholinergics for chronic use. Consideration should be given to progressing to advanced therapy (botulinum toxin or neuromodulation) earlier in the OAB treatment paradigm

Conclusions

The current body of literature supports a likely small but significant increased risk of dementia with chronic exposure to OAB anticholinergic medications. Potential harms should be balanced against potential quality of life improvement with treatment.
On the limitations of low‐rank approximations in contact mechanics problems
Authors: Kollepara Kiran Sagar , Navarro‐Jiménez José M. , Le Guennec Yves , Silva Luisa , Aguado José V.
Published: September 2022

Typical strategies for reducing the computational cost of contact mechanics models use low‐rank approximations. The underlying hypothesis is the existence of a low‐dimensional subspace for the displacement field and a non‐negative low‐dimensional subcone for the contact pressure. However, given the local nature of contact, it seems natural to wonder whether low‐rank approximations are a good fit for contact mechanics or not. In this article, we investigate some of their limitations and provide numerical evidence showing that contact pressure is linearly inseparable in many practical cases. To this end, we consider various mechanical problems involving nonadhesive frictionless contacts and analyze the performance of the low‐rank models in terms of three different criteria, namely, compactness, generalization, and specificity.
Enhanced crystallization of poly(lactic acid) bioplastics by a green and facile approach using liquid poly(ethylene glycol)
Authors: Lai Wei‐Chi , Liu Li‐Jie
Published: September 2022

Polylactic acid (PLA) bioplastics have attracted increasing attention from both academic and industrial researchers due to their biomass‐derived nature and low toxicity for the human body and environment. A major drawback of PLA is slow crystallization during processing, which considerably limits its commercial applications. In this study, a simple and low‐cost approach involving the addition of eco‐friendly low molecular weight poly(ethylene glycol) (PEG; 400 g/mole) as a green solvent was developed to enhance the PLA crystallization process. Differential scanning calorimetry and polarized optical microscopy data revealed that the introduction of PEG into PLA considerably increased the PLA crystallization rate. In particular, the isothermal crystallization rate of a system with a PLA/PEG mass ratio of 70/30 was more than seven times greater than that of neat PLA. In addition, the miscibility, thermal properties, and microstructures of various PLA/PEG blends were determined. A substantial reduction in the equilibrium melting temperature of PLA after PEG addition confirmed that these polymer blends were thermodynamically miscible in the melt, which strongly influenced the PLA crystallization rate. Furthermore, the addition of PEG increased the regularity of PLA crystals and induced the formation of ring‐banded PLA spherulites with periodic twisted lamellae.
Effects of pressure on the cross‐linking behavior of hyaluronic acid‐functionalized boric acid cross‐linked poly(vinyl alcohol) hydrogels
Authors: Hu Feng , Lu Hailin , Wu Changlei , Xu Guangshen , Shao Zhonglei , Gao Li
Published: September 2022

With their excellent properties, hydrogels have attracted much attention for their potential application. However, it is still necessary to study the influencing factors of the hydrogel preparation process and its self‐healing mechanism. In this paper, the preparation method of boric acid (BA) cross‐linked poly(vinyl alcohol) (PVA)/hyaluronic acid (HA) hydrogel appeared to become studied in order to explore the effect of pressure in the cross‐linking process. Associated with, PVA and HA were combined, and then the mixture was cross‐linked with BA to produce BA‐PVA/HA hydrogel. The state of the hydrogel after cross‐linking was transformed after centrifugal pressure method, and its performance was analyzed experimentally. Compared with the BA‐PVA/HA hydrogel without centrifugal supercharging, the hydrogel after centrifugation has lower water content and lubricating effect, and the surface hardness is improved at the same time. In addition, the BA‐PVA/HA hydrogel has no external stimulation at room temperature, can also self‐heal quickly have based on hydrogen bonds, and has good recyclability. These results indicate that adding centrifugation steps in the preparation of BA‐PVA/HA hydrogels could properly switch the state of the hydrogels, which is expected to provide a certain research basis for the preparation and application of hydrogels.
In‐situ exfoliation and thermal conductivity in phase‐transition‐assisted melt blending fabrication of low‐density polyethylene/expanded graphite nanocomposite
Authors: Yin Xiaochun , Jie Xi , Wei Kesai , He Guangjian , Feng Yanhong
Published: September 2022

Expanded graphite (EG) exhibits excellent thermal property, high specific surface area, and large aspect ratio, which show promise for fabricating polymer composites with high thermal conductivity. However, the wormlike structure of EG makes it difficult to be exfoliated and dispersed in polymer matrix. To meet this challenge, herein, a one‐step melt mixing strategy based on the phase‐transition‐assisted in‐situ exfoliation is developed to fabricate EG‐low density polyethylene composites with high thermal conductivity. SEM images and WAXD analyses showed that the internal force generated by phase transition makes EG to be quickly exfoliated and dispersed in melts within 8 min. POM images and DSC results suggested that the exfoliated EG can introduce heterogeneous nucleation to LDPE macromolecules and improve the crystallinity of composites. Moreover, the EG‐LDPE composites prepared by this strategy have a thermal conductivity of 0.715 Wm−1 K−1 with the loading of 5 wt. % EG. This value exceeds the composites prepared by regular melt mixing, achieving the enhancement efficiency of graphene nanoplatelets (GNP). This strategy has great potential in preparing polymer composites with high thermal conductivity.
Mass production of crystalline silicon solar cells with polysilicon‐based passivating contacts: An industrial perspective
Authors: Zhang Xinyu , Dumbrell Robert , Li Wenqi , Xu Menglei , Yan Di , Jin Jingsheng , Wang Zhao , Zheng Peiting , Liu Changming , Yang Jie
Published: September 2022

Silicon solar cells that employ passivating contacts featuring a heavily doped polysilicon layer on a thin silicon oxide (TOPCon) have been demonstrated to facilitate remarkably high cell efficiencies, amongst the highest achieved to date using a single junction on a silicon substrate. Importantly, it has been shown that the polysilicon‐based passivating contacts have a high degree of compatibility with existing mass production processes and toolsets, making them an attractive choice for photovoltaic (PV) cell manufacturers to increase the efficiency of their products. With several large PV manufacturers recently announcing plans to push the TOPCon technology into mass production, we review the significant industrial research and development activities that have been undertaken to push the boundaries of the technology and optimise its integration into the existing mass production pipeline. From an industrial perspective, TOPCon fabrication methodology options as well as necessary technological advances in front‐side fabrication, cell metallisation and module integration are discussed. The TOPCon technology development is contextualised in terms of larger trends in PV manufacturing, and we look towards the direction of future industrial development.
Effects of the β‐heteroatom and leaving group on neighbouring group participation in the gas phase: A density functional theory study
Authors: Brydon Samuel C. , White Jonathan M. , O'Hair Richard A. J.
Published: September 2022

Observation of the [M + H]+ ion in electrospray ionisation mass spectrometry (ESI‐MS) for either product identification or further unimolecular reactivity studies is not always guaranteed. When a suitable donor is β to a good leaving group such as protonated alcohols, neighbouring group participation (NGP) is one process that can lead to facile in‐source decomposition leading to three‐membered ring product ions. In this study, lone pair rich heteroatoms are explored computationally as donors for the intramolecular displacement of either water or ammonia in protonated 2‐heteroethanols and ethanamines, respectively. Density functional theory (DFT) calculations showed that for the halogens (Cl, Br and I) both the loss of water and ammonia are overall endothermic processes with modest barriers for the 2‐haloethanol fragmentation by NGP. The chalcogens (S, Se and Te) displayed a significant shift with the loss of water becoming exothermic and the enthalpic barrier approximately zero in most cases leading to little [M + H]+ ion observation. The loss of ammonia remained endothermic for both the chalcogens (S, Se and Te) and pnictogens (P, As and Sb), but the 2‐pnictoethanol fragmentation showed mixed results as two pathways were accessible due to the increased s character of the pnictogen lone pair. Examination of the donor–acceptor interactions by natural bond orbital (NBO) theory reflected an increase in the heteroatom lone pair participation at the transition state, but that stabilisation due to the polarisable CX bond dominated and should not be discounted in processes believed to proceed by nonvertical neighbouring group participation.
E‐Government maturity assessment: Evidence from Greek municipalities
Authors: Patergiannaki Zoi , Pollalis Yannis
Published: September 2022

Several e‐Government maturity models have been developed throughout the years to assess the progress of e‐Government. This diversity of models has drawn some criticism in terms of their similarity, oversimplicity, one‐sided view and the characteristics incorporated in their stages. The goal of this study is to explore if a simple e‐Government maturity model can capture e‐Government progress and if operations can be classified into phases to give a realistic view of e‐Government. An adapted version of the United Nations e‐Government maturity model was used to assess the portals of the 50 largest municipalities of Greece. The factors influencing the e‐Government maturity development are examined through ordinal regression. The findings suggest that e‐Government maturity models have limited ability to capture the e‐Government development as it may not be considered linear. Municipal authorities have taken steps towards e‐Government, however, they are missing functionalities that are at the core of digital transformation. Finally, the findings indicate, that factors such as population, political ideology of the ruling party, budget and the mayor's gender have limited role in predicting the e‐Government maturity in the cases examined.
Variability and genetic determinants of cocoa aromas in trees native to South Ecuadorian Amazonia
Authors: Colonges Kelly , Loor Solorzano Rey Gastón , Jimenez Juan‐Carlos , Lahon Marie‐Christine , Seguine Edward , Calderon Darío , Subia Cristian , Sotomayor Ignacio , Fernández Fabián , Lebrun Marc , Fouet Olivier , Rhoné Bénédicte , Argout Xavier , Costet Pierre , Lanaud Claire , Boulanger Renaud
Published: September 2022

Societal Impact Statement

Recent surveys conducted on Amazonian cocoa trees in their home range are a unique opportunity to assess the aromas, diversity and potential of the Ecuadorian Amazon to create new aromatic cocoa varieties. Our results reveal informations about the diversity and genesis of aromas in Ecuadorian fine cocoa. The great aromatic diversity could enrich cocoa flavour selection programmes and provide Amazonian populations with new income linked to aromatic varieties, which could lead to a ‘grand cru’ chocolate. Until now, breeding programmes have been mainly focused on improving characteristics for production, but in recent years cocoa quality has been increasingly examined to meet market expectations.

Ecuador is known worldwide for its fine or flavour cocoa from the Nacional variety. Currently, farmers mainly grow the modern Nacional variety of cocoa trees (hybrids between the ancestral Nacional and Trinitario) while the ancestral Nacional variety tends to be neglected. In order to enlarge the genetic resources related to this ancestral variety, several surveys were carried out in its area of origin located in the South Ecuadorian Amazonia.

The 202 trees resulting from these surveys were genotyped using GBS (Genotyping By Sequencing) markers and their dried‐fermented beans were characterised for both their aromatic volatile compounds and sensorial quality. A genome wide association study (GWAS) was carried out with the aim to study the genetic and biochemical bases of the aroma traits of this population and to better exploit them in breeding programmes.

Some association areas and candidate genes related to spicy and woody aromas were found for the first time in Theobroma cacao. Some association areas and candidate genes related to floral and fruity aromas common to other studies were identified.

Our results support the hypothesis that aroma formation may be related to a defence reaction to biotic and abiotic stresses generated by the fermentation process.
Identification of the Degradation Products from α‐Tocopherol Used as Stabiliser in “Green” Propellants through its Lifetime
Authors: Damseaux Caroline , Scholl Georges , Damblon Christian , Dejeaifve Alain , Dobson Rowan , De Pauw Edwin , Eppe Gauthier
Published: September 2022

Stabilisers are added to gun and rocket propellants to react with species responsible for nitrate ester degradation during storage. The degradation products can be toxic and therefore harmful. There is a need to replace such stabilisers by “green” molecules and to study their degradation patterns through ageing. Propellant powders must remain chemically stable for a minimum of ten years when stored at temperatures equivalent to 25 °C [1]. α‐Tocopherol is a natural product that has been known for decades in other fields (Vitamin E) such as the pharmaceutical, food and cosmetics industries. It can act as a ‘green’ stabiliser” for smokeless powders because its heat flow is stable over time. In this paper, we characterise its stabilisation mechanism by identifying its main degradation products that could form within the propellant in an oxidising environment and in the presence of nitric acid. Liquid chromatography (LC) and gas chromatography (GC) separations are performed in order to dissociate the compounds formed during ageing. Compounds are then analysed by APCI‐timsTOF to obtain the molecular ion masses and then perform fragmentation spectra (MS/MS) to characterise their structure. In addition, using preparative HPLC‐UV, the degradation products are collected and analysed by NMR, with the aim of identifying the molecules. These identification methods help to unravel the stabilisation mechanism under accelerated ageing conditions. A time‐related fluctuation of the degradation products amounts is also observed, which indicates that the decomposition products also have a stabilisation effect. The three major α‐tocopherol degradation products are identified as: 2,3‐epoxy‐α‐tocopherylquinone, 5,6‐epoxy‐α‐tocopherylquinone and α‐tocored.
Malawi polio outbreak: What next?
Authors: Kazanga‐Chiumia Isabel , Nayupe Symon Fidelis , Kazanga Betty , Munharo Steven , Patel Parth , Jassi Phatisan Bango , Phuka John
Published: September 2022

Since, the last polio case was in 1992, health authorities in Malawi declared an outbreak of wild poliovirus type 1 (WPV1) on 17 February 2022. A 3‐year‐old girl was diagnosed with WPV1 in the country's capital, Lilongwe, after getting paralyzed by the virus in November 2021. The re‐emergence of polio presents a new public health challenge that Malawi must respond to avoid the further spread of the virus within and outside the country. With an ongoing Coronavirus disease (Covid‐19) pandemic, responding to polio could be a challenge as the healthcare system is already challenged with responding to the pandemic. Frequent cross‐border movement in the region also poses another challenge, particularly in the background of poor vaccination coverage and poor‐quality vaccines. We recommend the development of a risk assessment plan that will guide in implementing vaccination campaigns. Additionally, polio surveillance programmes must be put in place with strong political, stakeholder and community engagement.
A rapid high‐precision analytical method for triple oxygen isotope analysis of CO2 gas using tunable infrared laser direct absorption spectroscopy
Authors: Perdue Nathan , Sharp Zachary , Nelson David , Wehr Rick , Dyroff Christoph
Published: September 2022

Rationale

The simultaneous analysis of the three stable isotopes of oxygen—triple oxygen isotope analysis—has become an important analytical technique in natural sciences. Determination of the abundance of the rare 17O isotope in CO2 gas using magnetic sector isotope ratio mass spectrometry is complicated by the isobaric interference of 17O by 13C (13C16O16O and 12C16O17O, both have mass 45 amu). A number of analytical techniques have been used to measure the 17O/16O ratio of CO2 gas. They either are time consuming and technically challenging or have limited precision. A rapid and precise alternative to the available analytical methods is desirable.

Methods

We present the results of triple oxygen isotope analyses using an Aerodyne tunable infrared laser direct absorption spectroscopy (TILDAS) CO2 analyzer configured for 16O, 17O, and 18O combined with a custom gas inlet system. We evaluate the sensitivity of our results to a number of parameters. CO2 samples with a wide range of δ18O values (from −9.28‰ to 39.56‰) were measured and compared to results using the well‐established fluorination‐gas source mass spectrometry method.

Results

The TILDAS system has a precision (standard error, 2σ) of better than ±0.03‰ for δ18O and ±10 per meg for Δ′17O values, equivalent to the precision of previous analytical methods. Samples as small as 3 μmol CO2 (equivalent to 300 μg CaCO3) can be analyzed with a total analysis time of ~30 min.

Conclusions

We have successfully developed an analytical technique for the simultaneous determination of the δ17O and δ18O values of CO2 gas. The precision is equal to or better than that of existing techniques, with no additional chemical treatments required. Analysis time is rapid, and the system is easily automated so that large numbers of samples can be analyzed with minimal effort.
Testosterone and Covid‐19: An update
Authors: Yassin Aksam , Shabsigh Ridwan , Al‐Zoubi Raed M. , Aboumarzouk Omar M. , Alwani Mustafa , Nettleship Joanne , Kelly Daniel
Published: September 2022

There is overwhelming evidence to suggest that male gender is at a higher risk of developing more severe Covid‐19 disease and thus having poorer clinical outcomes. However, the relationship between testosterone (T) and Covid‐19 remains unclear with both protective and deleterious effects on different aspects of the disease suggested. Here, we review the current epidemiological and biological evidence on the role of testosterone in the process of SARS‐CoV‐2 infection and in mediating Covid‐19 severity, its potential to serve as a biomarker for risk stratification and discuss the possibility of T supplementation as a treatment or preventative therapy for Covid‐19.
The Prominent Motif of the Leaving Group in Chemical and Biological Processes of Phosphonoesters: Understanding the Behavior of V‐type Nerve Agents
Authors: Elias Shlomi , Columbus Ishay , Shoshanim Ofir , Mizrahi Dana , Chen Ravit , Yehezkel Lea , Ghindes‐Azaria Lee , Ashkenazi Nissan , Zafrani Yossi
Published: September 2022

The solvolysis of the extremely toxic nerve agent VX and its derivatives ((OEt)MeP(O)LG, LG is leaving group), promoted by nucleophiles such as fluoride, hydroxide/water or methoxide/methanol, revealed major differences in both reaction rates and products distribution. To rationalize these differences, which are of high relevance for different issues such as toxicity, persistence and decontamination of V‐type nerve agents, we conducted a combined experimental and computational (DFT) study on a series of derivatives in which only the LG was varied (O/S, N/C and more replacements). Experimentally, a high dependence of these solvolysis reactions on the LG's nature, mainly its pKa value and the presence of β‐amine moiety was observed. The DFT calculations showed that the transition states energies for P‐LG bond cleavage, by fluoride or hydroxide are roughly similar for P−S scission while for P−O cleavage sharp difference was observed in favor of hydroxide. This LG′s effect was also found to be an important determinant in biochemical processes as shown by the relative phosphonylation rates and toxicity of the described V‐type nerve agents and analogues.
Surface Engineering of Ni wires and Rapid Growth Strategy of Ni‐MOF Synergistically Contribute to High‐Performance Fiber‐Shaped Aqueous Battery
Authors: Gong Jiaxu , Luo Weige , Zhao Yang , Wang Jiaheng , Wang Shuai , Hu Cunhai , Yang Junxiao , Dai Yatang
Published: September 2022

The fiber‐shaped aqueous battery (FSAB) has the advantages of flexibility, portability and safety making it promising for energy storage applications. In particular, FSABs based on metal wire current collectors with good electrical conductivity can provide excellent energy storage properties. However, the low adhesion caused by the smooth surface of the metal wire and the unavailability of many electrochemically active materials for use in FSAB is holding back their development. Herein, a substrate is effectively constructed for the strongly applicable growth of the active material via a Ni wire etching strategy. In addition, core‐shell structured nanorod arrays consisting of NiCo2O4 and Ni‐metal–organic frameworks (MOFs) are constructed, where Ni‐MOF can be obtained rapidly via β‐Ni(OH)2 intermediates. The NCO/NM‐15 electrode obtained by structural regulation exhibits high capacity and outstanding cycling stability. De calculations further demonstrate that the formation of NiCo2O4 and Ni‐MOF heterostructures results in a significant increase in the Fermi level leading to more active internal electrons, which facilitates electron transfer in electrochemical reactions. An assembled FSAB device can provide an energy density of 158.33 µWh cm−2 and the devices can provide power for a calculator and an electronic watch screen, demonstrating a wide application prospect in the field of energy storage.
Decentralized identifier based illegal digital content distribution tracking system using the format‐preserving encryption algorithm
Authors: Kwon Soonhong , Park Jaehyoung , Lee Taeyang , Oh SungHeun , Lee Jong‐Hyouk
Published: September 2022

The coronavirus pandemic, which first began in December 2019, has completely changed our daily lives. In particular, daily online digital content consumption over the world has soared since the start of the coronavirus pandemic. For preventing illegal digital content distribution, various technologies have been applied, but current copyright protection technologies are still lacking to provide secure digital content distribution while preserving privacy. In this article, we introduce a new digital content distribution system, which utilizes blockchain‐based decentralized identifier and format‐preserving encryption to enable user privacy preserved digital content tracking. We present the system architecture with detailed message flows of the proposal and provide its analysis result in terms of security and overhead.
Dutch veterinary graduates leaving practice: A mixed‐methods analysis of frequency and underlying reasons
Authors: Sonneveld Danse , Goverts Yvonne , Duijn Chantal C. M. A. , Camps Guido , Bougie Roger , Mastenbroek Nicole J. J. M.
Published: September 2022

Background

This study aimed to evaluate the frequency of veterinarians graduated between 2009 and 2019 in the Netherlands leaving practice, their reasons for leaving and the relative importance of these reasons.

Methods

Study 1 (focus group sessions,n= 14) of this project was aimed at defining the reasons Dutch veterinarians have for leaving veterinary practice within 10 years of graduation. In study 2, the frequency of veterinarians leaving veterinary practice and the relative importance of the reasons for leaving identified in study 1 were investigated through a cross‐sectional digital survey. A career in veterinary practice was defined as working in first‐ or second‐line veterinary practice. Leaving practice was defined as ending employment in veterinary practice.

Results

The results of study 1 yielded 20 reasons given by veterinarians to leave veterinary practice within 10 years of graduation. One of the reasons obtained by this study was not mentioned in literature before: leaving veterinary practice as a pre‐planned career path. Study 2 demonstrated that the mean percentage of respondents from graduation years 2009 to 2014 who left practice within 5 years of graduation was 16.8%. The most important reasons respondents gave for this career move were poor work–life balance, excessive workload, insufficient remuneration and perceived lack of employer support.

Conclusion

A substantial number of veterinarians leave veterinary practice within 5 years of graduation. The most important reasons for this decision are excessive job demands or insufficient job resources. Furthermore, these reasons are a result of negative experiences regarding organisation of work, management and remuneration.
Roles of minor spliceosome in intron recognition and the convergence with the better understood major spliceosome
Authors: Ding Zhan , Meng Yan‐Ran , Fan Yu‐Jie , Xu Yong‐Zhen
Published: September 2022

Catalyzed by spliceosomes in the nucleus, RNA splicing removes intronic sequences from precursor RNAs in eukaryotes to generate mature RNA, which also significantly increases proteome complexity and fine‐tunes gene expression. Most metazoans have two coexisting spliceosomes; the major spliceosome, which removes >99.5% of introns, and the minor spliceosome, which removes far fewer introns (only 770 at present have been predicted in the human genome). Both spliceosomes are large and dynamic machineries, each consisting of five small nuclear RNAs (snRNAs) and more than 100 proteins. However, the dynamic assembly, catalysis, and protein composition of the minor spliceosome are still poorly understood. With different splicing signals, minor introns are rare and usually distributed alone and flanked by major introns in genes, raising questions of how they are recognized by the minor spliceosome and how their processing deals with the splicing of neighboring major introns. Due to large numbers of introns and close similarities between the two machinery, cooperative, and competitive recognition by the two spliceosomes has been investigated. Functionally, many minor‐intron‐containing genes are evolutionarily conserved and essential. Mutations in the minor spliceosome exhibit a variety of developmental defects in plants and animals and are linked to numerous human diseases. Here, we review recent progress in the understanding of minor splicing, compare currently known components of the two spliceosomes, survey minor introns in a wide range of organisms, discuss cooperation and competition of the two spliceosomes in splicing of minor‐intron‐containing genes, and contributions of minor splicing mutations in development and diseases.

This article is categorized under:

RNA Processing > Processing of Small RNAs

RNA Processing > Splicing Mechanisms

RNA Structure and Dynamics > RNA Structure, Dynamics and Chemistry
Phylogenies in yeast species descriptions: In defense of neighbor‐joining
Authors: Lachance Marc‐André
Published: September 2022

The neighbor‐joining (NJ) method of tree inference is examined, with special attention to its use in yeast species descriptions. How the often‐vilified method works is often misunderstood. More importantly, given the right kind of data, its output is a phylogram that illustrates a hypothetical phylogeny that is just as credible as that obtained by any other method. And as with any other method, the result is greatly affected by sampling intensity, particularly the number of aligned positions used for analysis. I address various allegations, including the claim that the method is phenetic, and, therefore, not phylogenetic. I argue that NJ is the most suitable tree inference method to use in yeast species descriptions, primarily because it is best at visually preserving the extent of sequence divergence between close relatives, which continues to be the primary criterion for yeast species delineation. The relevance of bootstraps in the application of the phylogenetic species concept is discussed.
3D printing MOFs‐based fiber electrodes: A novel platform as electrochemical sensors for heavy metal ions
Authors: Li Yanping , Wan Yating , Wang Yafei , Zhang Yan
Published: September 2022

Pb2+ probes play an important part in environments and human health. We developed a new free‐standing electrochemical probe by 3D printing UiO‐66‐NH2 with @rGO. This free‐standing fiber electrochemical sensor exhibited good structural stability and Pb2+ sensing performance with enhanced conductivity. This MOFs‐based hybrid probe showed an excellent sensing sensitivity for Pb2+ with a very low detection limit of 0.041 μM, significantly lower than the standard for Pb2+ in drinking water as a result of the porous structure of UiO‐66‐NH2 and the good conductivity of rGO. This study highlighted a simple strategy for MOFs‐based hybrid sensor formation and accelerated the MOFs‐based materials for Pb2+ electrochemical detection in future practical applications.
Explaining with Diagrams for Promoting Deeper Learning: School Practice to Integrate Knowledge Across Subjects
Authors: Uesaka Yuri , Kurosawa Tsubasa , Furuya Kazumasa , Yanagimoto Shigeru , Liu Mengshi , Shiba Satomi , Uchida Nao
Published: September 2022

Diagrams are considered a powerful strategy for understanding and problem-solving. Self-explanation is believed to be behind the effectiveness of diagrams. However, it is not clear to what extent students engage in self-explanation. The possibility that students do not always engage in self-explanation is suggested by empirical studies showing that diagrams do not always produce efficacious outcomes. Ichikawa [1] also argued that it is unclear how students interpret diagrams and discussed the need to have students explain themselves using diagrams. In science learning, diagrams effectively help students learn the principles behind phenomena. Having students use diagrams to explain phenomena may help them understand the principles of the phenomena correctly and integrate their knowledge effectively across subject areas. Therefore, in this study, we developed lesson instructions in which students were required to explain the phenomenon using diagrams after the teacher had explained it. Students were also given the opportunity to solve the problem collaboratively after the explanation had been provided. The study involved 71 8th-grade students in one school. Fifty-eight same grade students from a traditional public school also participated in the study and served as the control group. A “basic knowledge test”, which tested students’ knowledge in a fill-in-the-blank format, and a “principle understanding test” and “transfer test,” which tested students’ knowledge in an explanation format, were administered. The results demonstrated no significant difference in the basic knowledge test, but the score in the principle understanding test and the transfer knowledge test was higher for the students who received the experimental instruction. This study indicates that deeper understanding is facilitated by combining the experience of using diagrams with peer explanation.
Carrollian and celestial spaces at infinity
Authors: Figueroa-O’Farrill José , Have Emil , Prohazka Stefan , Salzer Jakob
Published: September 2022

Abstract

We show that the geometry of the asymptotic infinities of Minkowski spacetime (in d + 1 dimensions) is captured by homogeneous spaces of the Poincaré group: the blow-ups of spatial (Spi) and timelike (Ti) infinities in the sense of Ashtekar-Hansen and a novel space Ni fibering over $$ \mathcal{I} $$
I
. We embed these spaces à la Penrose-Rindler into a pseudo-euclidean space of signature (d + 1, 2) as orbits of the same Poincaré subgroup of O(d + 1, 2). We describe the corresponding Klein pairs and determine their Poincaré-invariant structures: a carrollian structure on Ti, a pseudo-carrollian structure on Spi and a “doubly-carrollian” structure on Ni. We give additional geometric characterisations of these spaces as grassmannians of affine hyperplanes in Minkowski spacetime: Spi is the (double cover of the) grassmannian of affine lorentzian hyperplanes; Ti is the grassmannian of affine spacelike hyperplanes and Ni fibers over the grassmannian of affine null planes, which is $$ \mathcal{I} $$
I
. We exhibit Ni as the fibred product of $$ \mathcal{I} $$
I
and the lightcone over the celestial sphere. We also show that Ni is the total space of the bundle of scales of the conformal carrollian structure on $$ \mathcal{I} $$
I
and show that the symmetry algebra of its doubly-carrollian structure is isomorphic to the symmetry algebra of the conformal carrollian structure on $$ \mathcal{I} $$
I
; that is, the BMS algebra. We show how to reconstruct Minkowski spacetime from any of its asymptotic geometries, by establishing that points in Minkowski spacetime parametrise certain lightcone cuts in the asymptotic geometries. We include an appendix comparing with (A)dS and observe that the de Sitter groups have no homogeneous spaces which could play the rôle that the celestial sphere plays in flat space holography.
Benchmarking di-Higgs production in various extended Higgs sector models
Authors: Abouabid Hamza , Arhrib Abdesslam , Azevedo Duarte , El Falaki Jaouad , Ferreira Pedro M. , Mühlleitner Margarete , Santos Rui
Published: September 2022

Abstract

We present a comprehensive study on Higgs pair production in various archetypical extended Higgs sectors such as the real and the complex 2-Higgs-Doublet Model, the 2-Higgs-Doublet Model augmented by a real singlet field and the Next-to-Minimal Supersymmetric extension of the Standard Model. We take into account all relevant theoretical and experimental constraints, in particular the experimental limits on non-resonant and resonant Higgs pair production. We present the allowed cross sections for Standard Model (SM)-like Higgs pair production and the ranges of the SM-like Yukawa and trilinear Higgs self-coupling that are still compatible with the applied constraints. Furthermore, we give results for the pair production of a SM-like with a non-SM-like Higgs boson and for the production of a pair of non-SM-like Higgs bosons. We find that di-Higgs production in the models under investigation can exceed the SM rate substantially, not only in the non-resonance region but also due to resonant enhancement. We give several benchmarks with interesting features such as large cross sections, the possibility to test CP violation, Higgs-to-Higgs cascade decays or di-Higgs production beating single Higgs production. In all of our benchmark points, the next-to-leading order QCD corrections are included in the large top-mass limit. For these points, we found that, depending on the model and the Higgs pair final state, the corrections increase the leading order cross section by a factor of 1.79 to 2.24. We also discuss the relation between the description of Higgs pair production in an effective field theory approach and in the specific models investigated here.
Solutions in Nonlinear Electrodynamics and their double copy regular black holes
Authors: Mkrtchyan Karapet , Svazas Mantas
Published: September 2022

Abstract

We study solutions in non-linear electrodynamics (NED) and establish several general results. We show, that the SO(2) electric-magnetic duality symmetry is restrictive enough to allow for reconstruction of the NED Lagrangian from the spherically-symmetric electrostatic (Coulomb-like) solution — although there are infinitely many different NED theories admitting a given solution, there exists a unique SO(2) invariant one among them under a simple analyticity assumption (that leaves out some interesting physical theories). We introduce a general algorithm for constructing new SO(2) invariant NED theories in the conventional approach, where only a few examples are available. We also show how to derive the Lagrangian of the SO(2) invariant theory admitting a given electrostatic solution. We further show on a simple example that some NED theories may require sources (particles) of finite (non-zero) size. Such a non-zero size source not only regularizes the infinite energy of the point charge but also satisfies the condition of regularity, that the electric field is zero at the origin. The latter condition was identified earlier as necessary and sufficient for the NED solution to generate a regular black hole via so-called double copy construction and is also satisfied by solitons. We propose a large class of solitonic NED solutions that give rise to regular black holes via double copy construction and contain solutions of Maxwell and Born-Infeld as different limits. This class of NED solutions acquires two new properties in the limit where the corresponding regular black hole’s asymptotics becomes Minkowski: it gives rise to regular higher-spin black holes via generalization of double copy — “higher-copy” construction, and for very short distances changes the sign of the force becoming repulsive/attractive for opposite/similar signs of charges.
The Reissner-Nordström-Tangherlini solution from scattering amplitudes of charged scalars
Authors: D’Onofrio Simone , Fragomeno Federica , Gambino Claudio , Riccioni Fabio
Published: September 2022

Abstract

The metric and the electromagnetic potential generated by a static, spherically symmetric charged massive object in any dimension are given by the Reissner-Nordström-Tangherlini solution. We derive the expansion of this solution up to third post-Minkowskian order by computing the classical contribution of scattering amplitudes describing the emission of either a graviton or a photon from a massive charged scalar field up to two loops. In four and five dimensions these amplitudes develop ultraviolet divergences that are cancelled by higher-derivative counterterms in a way that generalises what was recently shown to happen in the chargeless case. This renormalisation procedure produces logarithmic terms that match exactly those produced in the post-Minkowskian expansion of the classical solution in de Donder gauge.