bluuebunny/crossref_metadata_2025 huggingface dataset:
Identification of metallic objects using spectral magnetic polarizability tensor signatures: Object classification
Authors: Wilson Ben A. , Ledger Paul D. , Lionheart William R. B.
Published: January 2022

The early detection of terrorist threat objects, such as guns and knives, through improved metal detection, has the potential to reduce the number of attacks and improve public safety and security. To achieve this, there is considerable potential to use the fields applied and measured by a metal detector to discriminate between different shapes and different metals since, hidden within the field perturbation, is object characterization information. The magnetic polarizability tensor (MPT) offers an economical characterization of metallic objects and its spectral signature provides additional object characterization information. The MPT spectral signature can be determined from measurements of the induced voltage over a range of frequencies in a metal signature for a hidden object. With classification in mind, it can also be computed in advance for different threat and non‐threat objects. In this article, we evaluate the performance of probabilistic and non‐probabilistic machine learning algorithms, trained using a dictionary of computed MPT spectral signatures, to classify objects for metal detection. We discuss the importance of using appropriate features and selecting an appropriate algorithm depending on the classification problem being solved, and we present numerical results for a range of practically motivated metal detection classification problems.
Polyacrylamide hydrogels prepared by varying water content during polymerization: Material characterization, reswelling ability, and aging resistance
Authors: Penkavova Vera , Spalova Anna , Tomas Jan , Tihon Jaroslav
Published: January 2022

As easily fabricated, polyacrylamide (PAAm) hydrogels are widely used, especially in medicine. Material properties of these crosslinked polymers are usually tuned by varying monomer/crosslinker ratio during polymerization. However, the properties of resulting hydrogels are affected by an all‐in composition of the reaction mixture. As the influence of water/monomer ratio has not been systematically studied yet, the objective of this study is to provide a comprehensive investigation of this way of hydrogel preparation together with a careful examination of resulting materials. The samples of PAAm hydrogels prepared with controlled contents of water in the reaction mixture vary in achieved swelling ratios (from 5 to 25) and rigidities (Young's modulus from 300 to 5 kPa). These material properties remain practically the same even if the hydrogels are dried and reswelled again. Performed long‐time testing suggests that the PAAm hydrogels can be stored either in wet or dry state, however, to avoid possible degradation by polymer hydrolysis, they should be placed in darkness and stored at no more than room temperature. The prepared hydrogels swell more in NaCl solutions than in water. As this swelling/shrinking behavior is reversible and independent of hydrogel history, it could be applied for remote control of hydrogel properties.
How to make PERC suitable for perovskite–silicon tandem solar cells: A simulation study
Authors: Messmer Christoph , Schön Jonas , Lohmüller Sabrina , Greulich Johannes , Luderer Christoph , Goldschmidt Jan Christoph , Bivour Martin , Glunz Stefan W. , Hermle Martin
Published: January 2022

Low‐cost and high‐efficiency tandem solar cells are promising candidates for a future industrial mass production. Nowadays, the passivated emitter and rear cell (PERC) technology makes up the major market share; therefore, it is an attractive option to use the PERC technology as bottom cell concept for a perovskite–silicon tandem device. Long‐term optimization of the PERC technology led to highly efficient, low‐cost, and mature devices. For PERC‐like bottom cells, mainly an adapted front‐side design is needed: Design constrains of a PERC single junction are relaxed to some extent, because such an updated PERC bottom cell only needs to absorb long wavelength photons, transports about half the current and, in a monolithic tandem, lateral transport, and the use of firing‐through local silver contacts is not a mandatory prerequisite. Consequently, to make PERC suitable for tandem application, a systematic reevaluation of the current PERC technology is performed here considering five different front‐side concepts. We investigate locally contacted and full‐area transparent conducting oxide (TCO)‐based interconnection concepts for PERC, as well as the full‐area tunnel oxide passivating contact (TOPCon). Our simulation work elaborates on the advantages and physical constrains of each concept and gives guidelines for the optimization of the phosphorus diffused emitter and front interconnection layers. We conclude that both full‐area and locally contacted front‐side concepts are promising candidates for achieving tandem cell efficiencies of about 30%.
Current status and trends in subspecialty certification in physical medicine and rehabilitation
Authors: Sabharwal Sunil , Kinney Carolyn L. , Raddatz Mikaela M. , Driscoll Sherilyn W. , Francisco Gerard E. , Robinson Lawrence R. , Geis Carolyn , Micheo William
Published: January 2022

Background

There is a need to better understand the overall state of sub‐specialization in physical medicine and rehabilitation (PM&R).

Objective

To examine the status and trends in subspecialty certification for each of the seven subspecialties approved for American Board of Physical Medicine and Rehabilitation (ABPMR) diplomates.

Design/Setting

Retrospective analysis of deidentified information from the ABPMR database.

Participants

Physicians certified by ABPMR through 2019.

Interventions

Not applicable.

Main Outcome Measures

For each subspecialty, we examined: (1) the number of certificates issued to ABPMR diplomates; (2) the recertification rate; (3) the yearly trends for total active, new, and expired certificates; and (4) for ABPMR‐administered subspecialties, recertification rates for those entering the subspecialty through fellowship completion versus a “grandfathered” practice pathway.

Results

Of 11,421 ABPMR diplomates in the United States in 2019, a total of 3560 (31.2%) had 3985 active subspecialty certificates. Pain Medicine (PM) was the most common subspecialty certification (15.5% of all ABPMR diplomates) followed by Sports Medicine (SM, 6.6%), Brain Injury Medicine (BIM, 4.8%), Spinal Cord Injury Medicine (SCIM, 4.2%), Pediatric Rehabilitation Medicine (PRM, 2.5%), Neuromuscular Medicine (NMM, 0.7%), and Hospice and Palliative Medicine (HPM, 0.5%). For diplomates with more than one subspecialty certification, PM and SM was the most frequent combination. Both the recertification rate and the end of practice track eligibility influenced certification trends differently for individual subspecialties. The average number of new certificates added annually for every subspecialty was higher before than after the temporary practice track‐based eligibility ended; the difference was statistically significant (p < .05) for SCIM, PM, SM, and NMM. The recertification rate for all subspecialties combined was 73.4%. For the subspecialties (SCIM, PRM) for which these data were available, fellowship candidates had higher recertification rates than those grandfathered through a practice track.

Conclusion

This report informs stakeholders about the state and evolution of subspecialty certification in PM&R over time.
Abiraterone switches castration‐resistant prostate cancer dependency from adrenal androgens towards androgen receptor variants and glucocorticoid receptor signalling
Authors: Moll J. Matthijs , Hofland Johannes , Teubel Wilma J. , de Ridder Corina M. A. , Taylor Angela E. , Graeser Ralph , Arlt Wiebke , Jenster Guido W. , van Weerden Wytske M.
Published: January 2022

Introduction

Castration‐resistant prostate cancer (CRPC) remains dependent on androgen receptor (AR) signalling, which is largely driven by conversion of adrenal androgen precursors lasting after castration. Abiraterone, an inhibitor of the steroidogenic enzyme CYP17A1, has been demonstrated to reduce adrenal androgen synthesis and prolong CRPC patient survival. To study mechanisms of resistance to castration and abiraterone, we created coculture models using human prostate and adrenal tumours.

Materials and Methods

Castration‐naïve and CRPC clones of VCaP were incubated with steroid substrates or cocultured with human adrenal cells (H295R) and treated with abiraterone or the antiandrogen enzalutamide. Male mice bearing VCaP xenografts with and without concurrent H295R xenografts were castrated and treated with placebo or abiraterone. Response was assessed by tumour growth and PSA release. Plasma and tumour steroid levels were assessed by LC/MS‐MS. Quantitative polymerase chain reaction determined steroidogenic enzyme, nuclear receptor and AR target gene expression.

Results

In vitro, adrenal androgens induced castration‐naïve and CRPC cell growth, while precursors steroids for de novo synthesis did not. In a coculture system, abiraterone blocked H295R‐induced growth of VCaP cells. In vivo, H295R promoted castration‐resistant VCaP growth. Abiraterone only inhibited VCaP growth or PSA production in the presence of H295R. Plasma steroid levels demonstrated CYP17A1 inhibition by abiraterone, whilst CRPC tumour tissue steroid levels showed no evidence of de novo intratumoural androgen production. Castration‐resistant and abiraterone‐resistant VCaP tumours had increased levels of AR, AR variants and glucocorticoid receptor (GR) resulting in equal AR target gene expression levels compared to noncastrate tumours.

Conclusions

In our model, ligand‐dependent AR‐regulated regrowth of CRPC was predominantly supported via adrenal androgen precursor production while there was no evidence for intratumoural androgen synthesis. Abiraterone‐resistant tumours relied on AR overexpression, expression of ligand‐independent AR variants and GR signalling.
Therapeutic roles of CAR T cells in infectious diseases: Clinical lessons learnt from cancer
Authors: Mohammadi Mahsa , Akhoundi Maryam , Malih Sara , Mohammadi Ali , Sheykhhasan Mohsen
Published: January 2022

Cancer immunotherapy has made improvements due to the advances in chimaeric antigen receptor (CAR) T cell development, offering a promising treatment option for patients who have failed to respond to traditional treatments. In light of the successful use of adoptive CAR T cell therapy for cancer, researchers have been inspired to develop CARs for the treatment of other diseases beyond cancers such as viral infectious diseases. Nonetheless, various obstacles limit the efficacy of CAR T cell therapies and prevent their widespread usage. Severe toxicities, poor in vivo persistence, antigen escape, and heterogeneity, as well as off‐target effect, are key challenges that must all be addressed to broaden the application of CAR T cells to a wider spectrum of diseases. The key advances in CAR T cell treatment for cancer and viral infections are reviewed in this article. We will also discuss revolutionary CAR T cell products developed to improve and enhance the therapeutic advantages of these treatments.
A Robust Approach to In Situ Exsolve Highly Dispersed and Stable Electrocatalysts
Authors: Wang Mengchu , Zhang Bike , Ding Jiaqi , Zhang Fanxing , Tu Rui , Bernards Matthew T. , He Yi , Xie Pengfei , Shi Yao
Published: January 2022

Catalysts made of in situ exsolved metal nanoparticles often demonstrate promising activity and high stability in many applications. However, the traditional approach is limited by perovskites as prevailing precursor and requires high temperature typically above 900 K. Here, with the guidance of theoretical calculation, an unprecedented and substantially facile technique is demonstrated for Cu nanoparticles exsolved from interstitially Cu cations doped nickel‐based hydroxide, which is accomplished swiftly at room temperature and results in metal nanoparticles with a quasi‐uniform size of 4 nm, delivering an exceptional CO faradaic efficiency of 95.6% for the electrochemical reduction of CO2 with a notable durability. This design principle is further proven to be generally applicable to other metals and foregrounded for guiding the development of advanced catalytic materials.
Water‐Processable and Multiscale‐Designed Vanadium Oxide Cathodes with Predominant Zn2+ Intercalation Pseudocapacitance toward High Gravimetric/Areal/Volumetric Capacity
Authors: Liu Xiong , Ni Wentao , Wang Yuan , Liang Yongle , Wu Banghui , Xu Guobao , Wei Xiaolin , Yang Liwen
Published: January 2022

Layered vanadium oxides have great potential as cathode materials for recently surged aqueous zinc‐ion batteries (AZIBs). However, achieving high energy/power densities simultaneously is challenging, and side reactions related to more frequently than disclosed Zn2+/proton co‐insertion mechanism aggravate stability concerns. Herein, an engineered binder‐free cathode configuration based on water‐processable and high packing‐density sheet‐shaped composites of carbon nanotubes network, surface poly(3,4‐ethylenedioxythiophene) (PEDOT) bridging coating, and ultrasmall PEDOT‐intercalated V2O5 nanoflakes is developed, and therein, large pseudocapacitance via predominant (≈91%) Zn2+ intercalation is revealed. Besides competitive gravimetric/areal capacity, the binder‐free cathodes exhibit high volumetric capacity of 1106.1 mAh cm−3 and high‐rate capability of 180.0 mA g−1 at 30 A g−1 as well as long‐cycling stability. Such combined level of performance and unwanted reaction mechanism are attributed to the contained multiscale material/electrode design formula from crystal structure modification to 3D architecture construction of whole electrode, which endows the binder‐free cathodes with abundant accessible sites for Zn2+ storage, but the least hydroxyl terminated surface for H+ insertion, as well as highly conductive network for electron transfer and fast Zn2+ diffusion kinetics throughout the electrode. Combined with scalable fabrication protocols, this study opens up great opportunities for high‐performance vanadium oxide cathodes practically applicable to AZIBs.
Enhanced Valley Polarization in WS2/LaMnO3 Heterostructure
Authors: Dang Jianchen , Yang Mingwei , Xie Xin , Yang Zhen , Dai Danjie , Zuo Zhanchun , Wang Can , Jin Kuijuan , Xu Xiulai
Published: January 2022

Monolayer transition metal dichalcogenides have attracted great attention for potential applications in valleytronics. However, the valley polarization degree is usually not high because of the intervalley scattering. Here, a largely enhanced valley polarization up to 80% in monolayer WS2 under nonresonant excitation at 4.2 K is demonstrated using WS2/LaMnO3 thin film heterostructure, which is much higher than that for monolayer WS2 on SiO2/Si substrate with a valley polarization of 15%. Furthermore, the greatly enhanced valley polarization can be maintained to a high temperature of about 160 K with a valley polarization of 53%. The temperature dependence of valley polarization is strongly correlated with the thermomagnetic curve of LaMnO3, indicating an exciton–magnon coupling between WS2 and LaMnO3. A simple model is introduced to illustrate the underlying mechanisms. The coupling of WS2 and LaMnO3 is further confirmed with an observation of two interlayer excitons with opposite valley polarizations in the heterostructure, resulting from the spin‐orbit coupling induced splitting of the conduction bands in monolayer transition metal dichalcogenides. The results provide a pathway to control the valleytronic properties of transition metal dichalcogenides by means of ferromagnetic van der Waals engineering, paving a way to practical valleytronic applications.
Direct Observation of Orbital Driven Strong Interlayer Coupling in Puckered Two‐Dimensional PdSe2
Authors: Ryu Jung Hyun , Kim Jeong‐Gyu , Kim Bongjae , Kim Kyoo , Kim Sooran , Park Jae‐Hoon , Park Byeong‐Gyu , Kim Younghak , Ko Kyung‐Tae , Lee Kimoon
Published: January 2022

Interlayer coupling between individual unit layers is known to be critical in manipulating the layer‐dependent properties of two‐dimensional (2D) materials. While recent studies have revealed that several 2D materials with significant degrees of interlayer interaction (such as black phosphorus) show strongly layer‐dependent properties, the origin based on the electronic structure is drawing intensive attention along with 2D materials exploration. Here, the direct observation of a highly dispersive single electronic band along the interlayer direction in puckered 2D PdSe2 as an experimental hallmark of strong interlayer couplings is reported. Remarkably large band dispersion along the kz‐direction near Fermi level, which is even wider than the in‐plane one, is observed by the angle‐resolved photoemission spectroscopy measurement. Employing X‐ray absorption spectroscopy and density functional theory calculations, it is revealed that the strong interlayer coupling in 2D PdSe2 originates from the unique directional bonding of Pd d orbitals associated with unexpected Pd 4d9 configuration, which consequently plays a decisive role for the strong layer‐dependency of the band gap.
A Solid‐Phase Conversion Sulfur Cathode with Full Capacity Utilization and Superior Cycle Stability for Lithium‐Sulfur Batteries
Authors: Wu Xiangjiang , Zhang Qian , Tang Guo , Cao Yuliang , Yang Hanxi , Li Hui , Ai Xinping
Published: January 2022

Solid phase conversion sulfur cathode is an effective strategy for eliminating soluble polysulfide intermediates (LiPSs) and improving cyclability of Li‐S batteries. However, realizing such a sulfur cathode with high sulfur loading and high capacity utilization is very challenging due to the insulating nature of sulfur. In this work, a strategy is proposed for fabricating solid phase conversion sulfur cathode by encapsulating sulfur in the mesoporous channels of CMK‐3 carbon to form a coaxially assembled sulfur/carbon (CA‐S/C) composite. Vinyl carbonate (VC) is simultaneously utilized as the electrolyte cosolvent to in‐situ form a dense solid electrolyte interface (SEI) on the CA‐S/C composite surface through its nucleophilic reaction with the freshly generated polysulfides at the beginning of initial discharge, thus separating the direct contact of interior sulfur with the outer electrolyte. As expected, such a CA‐S/C cathode can operate in a solid phase conversion manner in the VC‐ether cosolvent electrolyte to exhibit a full capacity utilization (1667 mA h g–1, ≈100%), a high rate capability of 2.0 A g–1 and excellent long‐term cyclability over 500 cycles even at a high sulfur loading (75%, based on the weight of CA‐S/C composite), demonstrating great promise for constructing high‐energy‐density and cycle‐stable Li‐S batteries.
A Multifunctional Silicon‐Doped Polyether Network for Double Stable Interfaces in Quasi‐Solid‐State Lithium Metal Batteries
Authors: Zhang Qi , Liu Xiao , Li Hao , Guo Zhijie , Bian Tengfei , Zhu Xuebing , Zhan Niannian , Zhao Yong
Published: January 2022

Polymer‐based quasi‐solid‐state electrolyte (QSE) is an effective means to solve the safety problem of lithium (Li) metal batteries, and stable solid‐electrolyte‐interface (SEI) layers between electrolyte and anode/cathode are highly required for their long‐term stability. Herein, it is demonstrated that a silicon‐doped polyether functions as a multifunctional unit, which can induce the formation of stable and robust SEI layers with rich LixSiOy on both the surfaces of cathode and anode. It simultaneously solves the compatibility of electrolyte and electrodes in the quasi‐solid‐state Li‐metal battery. Moreover, the robust polymer skeleton with a cross‐linked network is beneficial to inhibit liquid volatilization and improve battery safety. The assembled Li|QSE|LiFePO4 batteries show a capacity retention rate as high as 97.5% after 400 cycles at 1 C (30 °C), and reach 78.1% after 1000 cycles. Furthermore, there is almost no attenuation of reversible capacity after 100 cycles for the assembled Li|QSE|LiNi0.8Mn0.1Co0.1O2 batteries. The concept of silicon‐doped polymer with a crosslinking structure provides an important strategy for designing solid‐state or quasi‐solid‐state polymer electrolytes for the stable long‐term operation of both anode and cathode.
Constructing High Efficiency CoZnxMn2–xO4 Electrocatalyst by Regulating the Electronic Structure and Surface Reconstruction
Authors: Zhao Depeng , Zhang Rui , Dai Meizhen , Liu Hengqi , Jian Wei , Bai Fu‐Quan , Wu Xiang
Published: January 2022

It is an effective strategy to develop novel electrocatalysts with controllable defects to enhance their electrocatalytic activity and stability. However, how to precisely design these catalysts on the atom scale remains very difficult. Herein, several vacancy‐dependent CoZnxMn2–xO4 catalysts are prepared through tailoring the concentration of Zn ions. The in situ activation of the obtained products accelerates the surface reconstruction. The superior electrocatalytic performance can be ascribed to the formations of MOOH (Mn, Co) active species and abundant oxygen vacancies, which are comparable to noble IrO2 and Pt/C catalysts. Zn‐CoMn2O4‐1.5 catalyst delivers a cell voltage of 1.63 V and long durability. Density functional theory calculations demonstrate that the appropriate Zn ion doping can improve the density states of p electron on the surface of catalysts significantly and benefit the d‐band center closing to Fermi level, suggesting their high charge carrier density and low adsorption energy.
A Shape‐Programmable Hierarchical Fibrous Membrane Composite System to Promote Wound Healing in Diabetic Patients
Authors: Li Weichang , Jiang Laibo , Wu Shujie , Yang Shiwen , Ren Lin , Cheng Bin , Xia Juan
Published: January 2022

Chronic wound infection is one of the critical complications of diabetes and is difficult to cure. Although great efforts have been made, the development of special dressings that serve as therapeutic strategies to effectively promote wound healing in diabetic individuals remains a major challenge. In this study, a shape‐programmable hierarchical fibrous membrane composite system is developed for synergistic modulation of the inflammatory microenvironment to treat chronically infected wounds. The system comprises a functional layer and a shape‐programmable backing layer. A temperature‐responsive shape‐memory mechanism achieves biaxial mechanically active contractions of diabetic wounds in a programmable manner. To summarize, the membrane system combines antimicrobial activity, controlled drug release according to the need of wound healing, mechanical modulation with shape‐programmable, robust adhesion, and on‐demand debonding to biological tissue to rationally guide chronic wound management. A synergistic combination of antibacterial fiber network and released drugs shows broad‐spectrum antibacterial activity. In vitro and in vivo evaluations indicate the dressing efficiency in promoting and supporting wound healing. The insights from this study demonstrate the effectiveness of a hierarchical composite membrane system with shape‐programmability as a potential treatment in the care of diabetic wounds.
Electronic Metal–Support Interaction Modulation of Single‐Atom Electrocatalysts for Rechargeable Zinc–Air Batteries
Authors: Wu Mingjie , Zhang Gaixia , Wang Weichao , Yang Huaming , Rawach Diane , Chen Mengjun , Sun Shuhui
Published: January 2022

High‐performance oxygen electrocatalysts play a key role in the widespread application of rechargeable Zn–air batteries (ZABs). Single‐atom catalysts (SACs) with maximum atom efficiency and well‐defined active sites have been recognized as promising alternatives of the present noble‐metal‐based catalysts for oxygen reduction reaction and oxygen evolution reaction. To improve their oxygen electrocatalysis activities and reveal the structure–activity relationship, many advanced synthesis and characterization methods have been developed to study the effects of 1) coordination and electronic structure of the metal centers and 2) morphology and stability of the conductive substrates. Herein, a detailed review of the recent advances of SACs with strong electronic metal–support interaction (EMSI) for rechargeable ZABs is provided. Great emphasis was placed on the EMSI forms and design strategies. Moreover, the importance and the impact of the atomic coordinating structure and the substrates on the oxygen electrocatalytic activity and stability are highlighted. Finally, future directions and perspectives on the development of SACs are also presented.
Upper Cretaceous European theropod palaeobiodiversity, palaeobiogeography and the intra‐Maastrichtian faunal turnover: new contributions from the Iberian fossil site of Laño
Authors: Isasmendi Erik , Torices Angelica , Canudo José Ignacio , Currie Philip J. , Pereda‐Suberbiola Xabier
Published: January 2022

A total of 227 theropod teeth have so far been recovered from the upper Campanian Laño site (northern Iberian Peninsula). The teeth were studied for their qualitative and quantitative features. From the theropod sample found at Laño, seven morphotypes attributed to five taxa are identified: a medium to large abelisaurid (Arcovenatorsp.) and four small coelurosaurians (Dromaeosauridae indet., Paraves indet., cf.Paronychodonsp. and cf.Richardoestesiasp.) Together with the ground birdGargantuavisand a possible ornithomimosaur, the theropod fauna of Laño might be composed of two medium–large‐sized non‐avian theropods, four small‐bodied non‐avian theropods and a large terrestrial bird. This makes the Laño site the richest and most diverse latest Cretaceous theropod site in Europe. Furthermore, the Laño site and the Upper Cretaceous localities of Europe that have yielded theropod remains suggest that the medium–large‐sized theropods were abelisaurids or indeterminate theropods. The small theropods are more abundant, diverse and represented by different dromaeosaurids,Paronychodon,Richardoestesiaor related forms, troodontids and, probably, by other paravians. Of the birds, enantiornithines, gargantuaviids and ornithurines are also common in the European Upper Cretaceous sites. The theropod assemblage of Laño, together with the taxa of other Upper Cretaceous sites, supports the idea that several theropod dispersal events took place during the Cretaceous. This resulted in a mixture of European endemic, Asiamerican and Gondwanan forms. This study also supports the hypothesis that the intra‐Maastrichtian faunal turnover that occurred in the Ibero‐Armorican landmass seems to have had no apparent effect on theropods.
Numerical Simulation of the Fluid Flow, Heat Transfer, and Solidification in Ultrahigh Speed Continuous Casting Billet Mold
Authors: Li Xintao , Zhang Zhaohui , Lv Ming , Fang Ming , Liu Kunlong
Published: January 2022

Ultrahigh‐speed casting is the most remarkable feature of billet high‐efficiency continuous casting. The transient fluid flow, heat transfer, and solidification behavior under different casting speeds, submerged entry nozzle (SEN) parameters, and mold electromagnetic stirring (M‐EMS) are investigated using a 3D transient mathematical model. The results show that a typical roll flow pattern is generated for all casting speeds, while a third small recirculation zone developed near the solidified shell at the casting speed of 6.0 m min−1. When the casting speed increases, the impact depth of the molten steel increases from 0.748 to 0.844 m, the velocity and level fluctuation at the steel/slag interface increases, the high‐temperature zone moves downward, and the shell thickness is reduced from 16.2 to 11.1 mm. As the SEN inner diameter and immersion depth increases, the impact depth increases, the velocity and level fluctuation at the steel/slag interface decreases, and the shell thickness at the mold exit is ≈11.0 mm. When the SEN immersion depth and inner diameter are 120 and 40 mm, respectively, the flow and temperature fields in the mold are the most appropriate. In addition, the M‐EMS have a great effect on the fluid flow and heat transfer behavior.
Ovarian response to P4‐PGF‐FSH treatment in Suffolk sheep and P4‐PGF‐PMSG synchronization in cross‐bred ewes, for IVD and ET protocol
Authors: Ciornei Ştefan Gregore , Drugociu Dan , Ciornei Liliana , Roşca Petru
Published: January 2022

Background

The success of an embryo transfer protocol in sheep depends on many factors, but the choice of drugs for the desired superovulation as well as the conception rate (CR) are most essential. Reproductive activity in sheep is characterized by a seasonality influenced by several factors such as photoperiod, latitude, temperature, nutrition and breed. Reproductive seasonality and nutritional condition are the main factors that influence embryo production in sheep. In sheep, some anatomical peculiarities limit the application of traditional reproductive biotechnologies used in cattle.

Objectives

The aim of this study was to conclude on the effectiveness of a wider on farm in vivo embryo transfer development programme in Suffolk sheep by streamlining hormone therapies and optimizing technique.

Methods

A total number of 60 sheep and three rams were included in this study, divided into two groups (receptors and donors). Donor Suffolk sheep were treated for superovulation using the P4‐PGF‐FSH multiple ovulation embryo transfer (MOET) protocol, while the cross‐bred recipients’ group was synchronized with P4‐PGF‐PMSG.

Results

On the first day after superovulation, all ovaries had more than five dominant follicles, while corpora lutea were later observed in 83.3% sheep. The recovery rate was 83.3%, while 72.9% embryos were transferable. Embryos were transferred directly into recipients. Fertility after 30 days was 68.57%, lambing rate was 91.6% and CR was 62.85%. This study showed that veterinary drugs (P4, FSH, LH, PMSG, PGF) used for superovulation optimized by us were capable of producing by this improved technique the optimization of the reproduction indices at embryo‐transfer (ET) and to be able to be used successfully.

Conclusions

The application of an MOET protocol has a positive effect in the production of in vivo embryo production (IVD) embryos in Suffolk sheep and can guarantee the success of embryo transfer activity to ewes with lower genetic merit. Our research aimed at representing a model for sheep farms for a rapid improvement of productive traits.
RNA thermometers and other regulatory elements: Diversity and importance in bacterial pathogenesis
Authors: Sharma Akanksha , Alajangi Hema Kumari , Pisignano Giuseppina , Sood Vikas , Singh Gurpal , Barnwal Ravi Pratap
Published: January 2022

Survival of microorganisms depends to a large extent on environmental conditions and the occupied host. By adopting specific strategies, microorganisms can thrive in the surrounding environment and, at the same time, preserve their viability. Evading the host defenses requires several mechanisms compatible with the host survival which include the production of RNA thermometers to regulate the expression of genes responsible for heat or cold shock as well as of those involved in virulence. Microorganisms have developed a variety of molecules in response to the environmental changes in temperature and even more specifically to the host they invade. Among all, RNA‐based regulatory mechanisms are the most common ones, highlighting the importance of such molecules in gene expression control and novel drug development by suitable structure‐based alterations.

This article is categorized under:

RNA Structure and Dynamics > RNA Structure, Dynamics and Chemistry

RNA in Disease and Development > RNA in Disease

RNA Structure and Dynamics > Influence of RNA Structure in Biological Systems
Synthesis and Structure of a New Bulky Hybrid Scorpionate/Cyclopentadienyl Ligand and its Lithium Complex
Authors: Mandel Miles J. , Görls Helmar , Westerhausen Matthias
Published: January 2022

The reaction of 5‐(1‐adamantyl)‐3‐methyl‐1H‐pyrazole with dibromomethane yields a product mixture of bis(3‐adamantyl‐5‐methylpyrazolyl)methane (H2C(PzAd,Me)2, 2 a), (3‐adamantyl‐5‐methylpyrazolyl)‐(3‐methyl‐5‐adamantylpyrazolyl)methane ((H2C(PzAd,Me)(PzMe,Ad), 2 b) and bis(3‐methyl‐5‐adamantylpyrazolyl)methane (H2C(PzMe,Ad)2, 2 c). Lithiation of sterically congested H2C(PzAd,Me)2 (2 a) and subsequent addition of diphenylfulvene yields lithium 1,1‐bis(3‐adamantyl‐5‐methylpyrazolyl)‐2,2‐diphenyl‐2‐ethyl‐cyclopentadienide, [(thf)Li{Cp−CPh2−CHPzAd,Me}] (3) which is unable to form a thf adduct but can be hydrolyzed to H5C5−CPh2−CHPzAd,Me (4). Adamantyl groups in 5‐position of bis(pyrazolyl)methane, i. e. 2 b and 2 c, prohibit formation of a fulvene adduct. For comparison reasons, [{H5C5−CPh2−CHPzMe2}LiI] (1 b) has been prepared via protolysis of (thf)lithium 1,1‐bis(3,5‐dimethylpyrazolyl)‐2,2‐diphenyl‐2‐ethyl‐cyclopentadienide, [(thf)Li{Cp−CPh2−CHPzMe2}] (1 a), in the presence of calcium iodide.
First natural breeding of the endangered dusky gopher frog (Lithobates sevosus) in captivity
Authors: Reichling Steven B. , Cantrell Jessica , Roznik Elizabeth A. , Bogisich Allison , Poo Sinlan
Published: January 2022

To date, all captive breeding of the dusky gopher frog, Lithobates sevosus, a federally listed endangered species, has been accomplished using in vitro fertilization (IVF). Here, we describe multievent and highly fecund captive reproduction of dusky gopher frogs driven solely by natural environmental factors. Six pairs of L. sevosus were kept in a 3.7 × 4.4 m2 outdoor enclosure designed to resemble their natural breeding habitat, which included a pool and three artificial burrows. Modifications to the enclosure that simulated temperatures and conditions within their natural range during winter were added in October and removed in late February. Following a warm, rainy period, five egg masses were laid between March 5 and 11, 2020. The number of oocytes per egg mass was 2300 ± 409 (range = 1341–3565), with the total across all five egg masses being 11,501. Of these oocytes, the hatching rate was 68.58 ± 10.05% (range = 37.53%–95.59%), with a total of 7887 successful hatchlings overall. Clutch sizes were similar to those in the wild and greater than those typically produced using IVF; thus, natural breeding can substantially increase the number of frogs available for reintroduction programs. Although assisted reproductive technologies such as IVF will continue to be useful for ensuring the success of strategic genetic pairings of captive L. sevosus, the new tool of nonassisted reproduction in specifically designed outdoor enclosures is an important advancement for the conservation and recovery of this endangered species.
Integrality, duality and finiteness in combinatoric topological strings
Authors: de Mello Koch Robert , He Yang-Hui , Kemp Garreth , Ramgoolam Sanjaye
Published: January 2022

Abstract

A remarkable result at the intersection of number theory and group theory states that the order of a finite group G (denoted |G|) is divisible by the dimension dR of any irreducible complex representation of G. We show that the integer ratios $$ {\left|G\right|}^2/{d}_R^2 $$

G

2

/

d
R
2

are combinatorially constructible using finite algorithms which take as input the amplitudes of combinatoric topological strings (G-CTST) of finite groups based on 2D Dijkgraaf-Witten topological field theories (G-TQFT2). The ratios are also shown to be eigenvalues of handle creation operators in G-TQFT2/G-CTST. These strings have recently been discussed as toy models of wormholes and baby universes by Marolf and Maxfield, and Gardiner and Megas. Boundary amplitudes of the G-TQFT2/G-CTST provide algorithms for combinatoric constructions of normalized characters. Stringy S-duality for closed G-CTST gives a dual expansion generated by disconnected entangled surfaces. There are universal relations between G-TQFT2 amplitudes due to the finiteness of the number K of conjugacy classes. These relations can be labelled by Young diagrams and are captured by null states in an inner product constructed by coupling the G-TQFT2 to a universal TQFT2 based on symmetric group algebras. We discuss the scenario of a 3D holographic dual for this coupled theory and the implications of the scenario for the factorization puzzle of 2D/3D holography raised by wormholes in 3D.
Mice harboring the FXN I151F pathological point mutation present decreased frataxin levels, a Friedreich ataxia-like phenotype, and mitochondrial alterations
Authors: Medina-Carbonero Marta , Sanz-Alcázar Arabela , Britti Elena , Delaspre Fabien , Cabiscol Elisa , Ros Joaquim , Tamarit Jordi
Published: January 2022

Friedreich Ataxia (FA) is a rare neuro-cardiodegenerative disease caused by mutations in the frataxin (FXN) gene. The most prevalent mutation is a GAA expansion in the first intron of the gene causing decreased frataxin expression. Some patients present the GAA expansion in one allele and a missense mutation in the other allele. One of these mutations, FXNI154F, was reported to result in decreased content of mature frataxin and increased presence of an insoluble intermediate proteoform in cellular models. By introducing this mutation into the murine Fxn gene (I151F, equivalent to human I154F) we have now analyzed the consequences of this pathological point mutation in vivo. We have observed that FXNI151F homozygous mice present low frataxin levels in all tissues, with no evidence of insoluble proteoforms. Moreover, they display neurological deficits resembling those observed in FA patients. Biochemical analysis of heart, cerebrum and cerebellum have revealed decreased content of components from OXPHOS complexes I and II, decreased aconitase activity, and alterations in antioxidant defenses. These mitochondrial alterations are more marked in the nervous system than in heart, precede the appearance of neurological symptoms, and are similar to those observed in other FA models. We conclude that the primary pathological mechanism underlying the I151F mutation is frataxin deficiency, like in patients carrying GAA expansions. Therefore, patients carrying the I154F mutation would benefit from frataxin replacement therapies. Furthermore, our results also show that the FXNI151F mouse is an excellent tool for analyzing tissue-specific consequences of frataxin deficiency and for testing new therapies.
Lower bounds on mixing norms for the advection diffusion equation in $$\mathbb {R}^d$$
Authors: Nobili Camilla , Pottel Steffen
Published: January 2022

An algebraic lower bound on the energy decay for solutions of the advection-diffusion equation in$$\mathbb {R}^d$$Rdwith$$d=2,3$$d=2,3is derived using the Fourier-splitting method. Motivated by a conjecture on mixing of passive scalars in fluids, a lower bound on the$$L^2$$L2- norm of the inverse gradient of the solution is obtained via gradient estimates and interpolation.
Stent-assisted WEB embolization: aneurysm characteristics, outcome and case report of a WEB delivered through a stent
Authors: Goertz Lukas , Liebig Thomas , Siebert Eberhard , Pflaeging Muriel , Forbrig Robert , Pennig Lenhard , Celik Erkan , Abdullayev Nuran , Schlamann Marc , Dorn Franziska , Kabbasch Christoph
Published: January 2022

Purpose

Woven Endobridge (WEB) embolization has become a well-established endovascular treatment option for wide-necked bifurcation aneurysms. The objective was to analyse cases that required additional stent-implantation.

Methods

Images of 178 aneurysms ≤ 11 mm treated by WEB only or by WEB plus stent were retrospectively reviewed, evaluating aneurysm characteristics, procedural specifics, adverse events and angiographic results. Moreover, we report a case of a WEB delivered through a previously implanted stent.

Results

Additional stent implantation was performed in 15 patients (8.4%). Baseline patient and aneurysm characteristics were comparable between both groups. A single stent was used in 12 cases and 2 stents in Y-configuration in 3. Thromboembolic complications occurred more often with stent assistance (33.3% vs. 8.0%, p = 0.002), while ischemic stroke rates were comparable between both groups (0% vs. 1.8%, p = 1.0). Six-month angiographic follow-up showed complete occlusion, neck remnants and aneurysm remnants in 73.4%, 19.4% and 7.3% after WEB only, respectively, and in 66.7%, 20.0% and 16.7% after WEB plus stent, respectively (p = 0.538). A case report shows that WEB deployment through the struts of a previously implanted standard microstent is feasible, even if a VIA 33 microcatheter is needed.

Conclusion

In the present study, stent-assisted WEB embolization had a comparable safety and efficacy profile compared to treatment by WEB only. However, stent-assisted WEB embolization requires long-term anti-platelet medication, which annihilates the advantages of the WEB as a purely intrasaccular device.

Clinical Trial registration number: N/A.
What is the evidence linking financial assistance for drought-affected agriculture and resilience in tropical Asia? A systematic review
Authors: Goodwin Daniel , Holman Ian , Pardthaisong Liwa , Visessri Supattra , Ekkawatpanit Chaiwat , Rey Vicario Dolores
Published: January 2022

Agriculture is sensitive to drought and associated social, environmental and economic impacts. Finance-based interventions aim to support farmers affected by drought; however, the extent to which such tools encourage resilience to this natural hazard is unclear. This paper systematically reviews evidence on links between financial interventions to mitigate drought-related impacts and adaptation towards longer-term resilience. We focus on tropical Asia where agriculture contributes significantly to national economies and is a primary source of livelihood in a region subject to high climate variability and episodic drought. Guided by Population, Intervention, Comparator and Outcome criteria, we identify and review 43 regionally specific articles that describe a range of financial interventions. Through thematic synthesis, we document the interventions’ associations with micro-level and macro-level outcomes. The results reveal how some interventions helped sustain household incomes and crop yield (e.g. through farm investments that increased productivity) through drought, whilst others encouraged adaptive behaviours. At a macro-level, there were challenges associated with government budgets and scheme administration, with the longevity of many schemes difficult to sustain. From fragmented evidence, this review reasons that there can be challenging policy trade-offs for institutions between supporting livelihoods and economic growth whilst also protecting the environment—highlighting the interdependence of systems’ resilience and variability in actors’ capacity to adapt. Low-regret interventions that integrate existing community adaptive practices, engage with farmers’ needs and prioritise extension support may encourage more desirable counteractions to drought; however, further research is needed to establish the role of such interventions.
Value drivers of development stage biopharma companies
Authors: Michaeli Daniel Tobias , Yagmur Hasan Basri , Achmadeev Timur , Michaeli Thomas
Published: January 2022

Objective

Scholars previously estimated research and development (R&D) costs of the internal drug development process. However, little is known about the costs and value arising from externally acquired therapeutics. This study identifies and estimates the magnitude of factors associated with Biopharma acquisition value.

Methods

SDC Thomson Reuter and S&P Capital IQ were screened for majority acquisitions of US and EU Biopharma companies developing new molecular entities for prescription use (SIC code: 2834) from 2005 to 2020. Financial acquisition data were complemented with variables characterizing the target’s product portfolio extracted from clinicaltrials.gov, Drugs@FDA database, US SEC filings, and transaction announcements. A multivariate regression assesses the association of firm value with extracted variables.

Results

311 acquisitions of companies developing prescription drugs were identified over the study period. Acquirers paid 37% (p < 0.05) more for companies with biologics and gene therapeutics than small-molecule lead drugs. Multi-indication products were acquired for a 12% premium per additional indication (p < 0.01). No significant valuation difference between companies developing orphan and non-orphan designated lead products was observed (18%, p = 0.223). Acquisition value positively correlated with the total number of further products, headquarter location in the US, underlying market conditions, and acquirer market capitalization (p < 0.05).

Conclusions

Internal and external drug development consumes many financial and human resources, yet it is important for entrepreneurs, regulators, and payers to understand their precise magnitude and value drivers. This information permits the design of targeted pricing and industrial policies that incentivize the development of novel drugs in areas with high unmet needs.
Constraining peripheral perception in instant messaging during software development by continuous work context extraction
Authors: Pham van Nghia , Vranić Valentino
Published: January 2022

Colocated software development teams benefit from natural work context building, which occurs mainly thanks to the team members, virtually, being forced to listen to what others are talking about. They absorb the information not by directing their attention to the communication, but by being exposed to it and perceiving it peripherally. The same effect of peripheral perception can be enforced with instant messaging, which is a predominant way of communication in distributed teams. However, forcing team members to observe too many and mostly unrelated message notifications can be distracting and causing unnecessary work interruption. This paper presents an approach and tool that ensure peripheral perception in instant messaging constrained by a continuously extracted work context. This is achieved by maintaining a personal work context from developer activities and using this context to filter instant messages to be displayed. A four-week experiment carried out with one of the teams of seven members in the Team Project course at our university indicates that message filtering based on continuous work context extraction performs better over common channel based filtering (as available in Slack). More precisely, message filtering based on continuous work context extraction decreases work interruption and distraction.
Biopsy-based optimization and calibration of a signal-intensity-ratio-based MRI method (1.5 Tesla) in a dextran-iron loaded mini-pig model, enabling estimation of very high liver iron concentrations
Authors: Jensen Peter D. , Nielsen Asbjørn H. , Simonsen Carsten W. , Jensen Kenneth K. , Bøgsted Martin , Jensen Anne B. H. , Kjaergaard Benedict
Published: January 2022

Objective

Magnetic resonance imaging (MRI)-based techniques for non-invasive assessing liver iron concentration (LIC) in patients with iron overload have a limited upper measuring range around 35 mg/g dry weight, caused by signal loss from accelerated T1-, T2-, T2* shortening with increasing LIC. Expansion of this range is necessary to allow evaluation of patients with very high LIC.

Aim

To assess measuring range of a gradient-echo R2* method and a T1-weighted spin-echo (SE), signal intensity ratio (SIR)-based method (TE = 25 ms, TR = 560 ms), and to extend the upper measuring range of the SIR method by optimizing echo time (TE) and repetition time (TR) in iron-loaded minipigs.

Methods

Thirteen mini pigs were followed up during dextran-iron loading with repeated percutaneous liver biopsies for chemical LIC measurement and MRIs for parallel non-invasive estimation of LIC (81 examinations) using different TEs and TRs.

Results

SIR and R2* method had similar upper measuring range around 34 mg/g and similar method agreement. Using TE = 12 ms and TR = 1200 ms extended the upper measuring range to 115 mg/g and yielded good method of agreement.

Discussion

The wider measuring range is likely caused by lesser sensitivity of the SE sequence to iron, due to shorter TE, leading to later signal loss at high LIC, allowing evaluation of most severe hepatic iron overload. Validation in iron-loaded patients is necessary.