bluuebunny/crossref_metadata_2025_split huggingface dataset:
Direct Solar Hydrogen Generation at 20% Efficiency Using Low‐Cost Materials
Authors: Wang Yuan , Sharma Astha , Duong The , Arandiyan Hamidreza , Zhao Tingwen , Zhang Doudou , Su Zhen , Garbrecht Magnus , Beck Fiona J. , Karuturi Siva , Zhao Chuan , Catchpole Kylie 
Published: July 2021

AbstractWhile direct solar‐driven water splitting has been investigated as an important technology for low‐cost hydrogen production, the systems demonstrated so far either required expensive materials or presented low solar‐to‐hydrogen (STH) conversion efficiencies, both of which increase the levelized cost of hydrogen (LCOH). Here, a low‐cost material system is demonstrated, consisting of perovskite/Si tandem semiconductors and Ni‐based earth‐abundant catalysts for direct solar hydrogen generation. NiMo‐based hydrogen evolution reaction catalyst is reported, which has innovative “flower‐stem” morphology with enhanced reaction sites and presents very low reaction overpotential of 6 mV at 10 mA cm−2. A perovskite solar cell with an unprecedented high open circuit voltage (Voc) of 1.271 V is developed, which is enabled by an optimized perovskite composition and an improved surface passivation. When the NiMo hydrogen evolution catalyst is wire‐connected with an optimally designed NiFe‐based oxygen evolution catalyst and a high‐performance perovskite‐Si tandem cell, the resulting integrated water splitting cell achieves a record 20% STH efficiency. Detailed analysis of the integrated system reveals that STH efficiencies of 25% can be achieved with realistic improvements in the perovskite cell and an LCOH below ≈$3 kg−1 is feasible.
Paraprofessional Youth Mentoring: A Framework for Integrating Youth Mentoring with Helping Institutions and Professions
Authors: McQuillin Samuel D. , Hagler Matthew A. , Werntz Alexandra , Rhodes Jean E. 
Published: July 2021

AbstractThe demand for child mental health services, including those provided by psychologists, counselors, and social workers, exceeds the supply. This trend is expected to continue or worsen unless there are substantial structural changes in how mental health services are provided. We propose a framework for paraprofessional youth mentors, defined as a subgroup of professionally supervised, non‐expert volunteer or paid mentors to whom aspects of professional helping tasks are delegated. Our proposal is aligned with historical and modern solutions to scaling mental health services, and this framework could simultaneously increase the number of youth receiving evidence‐based mental health services and reduce the burden on existing systems of care. The framework defines three plausible tasks for paraprofessional mentors: (1) reducing barriers to mental health service, (2) increasing engagement in services, and (3) providing direct services. The safety and effectiveness of these task‐shifting efforts will hinge on competency‐based training and evaluation, supervision by professionals, and documentation of services rendered, all of which the field of youth mentoring currently lacks. We describe several requisite scientific, institutional, and regulatory advances that will be necessary to realize this variant of youth mentoring for a subgroup of youth who are presenting for assistance with mental health problems.
Iridium‐Catalyzed Enantioselective Hydrogenation of 3‐Substituted Isoquinolinium Salts
Authors: Li Bin , Wang Jiaxin , Li Xiaoye , Xi Jiayue , Wang Ruoxuan , Zhang Dongxu , Zheng Xiaohui , Nie Huifang , Zhang Shengyong 
Published: July 2021

AbstractChiral tetrahydroisoquinolines (THIQ) is a highly important molecular skeleton in natural alkaloids and biologically active compounds, and its derivatives are often used as key intermediates for the synthesis of drugs. Herein, we described an efficient enantioselective hydrogenation of 3‐substituted isoquinolinium salts catalyzed by a bromine‐bridged dimeric complex [{Ir(H)[(R,S,Sax)‐Ph‐ax‐Josiphos]}2(μ‐Br)3]+Br−. This efficient enantioselective transformation could provide a series of useful chiral cyclic amines, which were of great potential value in natural product modification and drug molecular preparation in high yields and moderate to excellent enantioselectivities (68–97% ee). Additionally, turnover number experiments and a gram‐scale synthesis of chiral 3‐phenyltetrahydroisoquinoline were conducted.
Spatially Structured Optical Effects in a Four‐Level Quantum System Near a Plasmonic Nanostructure
Authors: Hamedi Hamid R. , Yannopapas Vassilios , Paspalakis Emmanuel 
Published: July 2021

AbstractThe light–matter interaction for a four‐level double‐V‐type quantum system interacting with a pair of weak probe fields while located near a 2D array of metal‐coated dielectric nanospheres is studied. A situation is considered in which one of the probe field carries an optical vortex, that is, an electromagnetic field with optical angular momentum, and the other probe field has no vortex. It is demonstrated that due to the phase sensitivity of the closed‐loop double V‐type quantum system, the linear and nonlinear susceptibility of the non‐vortex probe beam depends on the azimuthal angle and orbital angular momentum (OAM) of the vortex probe beam. This feature is missing in an open four‐level double V‐type quantum system interacting with free‐space vacuum, as no quantum interference occurs in this case. The azimuthal dependence of optical susceptibility of the quantum system is used to determine the regions of spatially structured transparency.
Spin‐Regulated Electron Transfer and Exchange‐Enhanced Reactivity in Fe4S4‐Mediated Redox Reaction of the Dph2 Enzyme During the Biosynthesis of Diphthamide
Authors: Feng Jianqiang , Shaik Sason , Wang Binju 
Published: July 2021

AbstractThe [4Fe‐4S]‐dependent radical S‐adenosylmethionine (SAM) proteins is one of large families of redox enzymes that are able to carry a panoply of challenging transformations. Despite the extensive studies of structure–function relationships of radical SAM (RS) enzymes, the electronic state‐dependent reactivity of the [4Fe‐4S] cluster in these enzymes remains elusive. Using combined MD simulations and QM/MM calculations, we deciphered the electronic state‐dependent reactivity of the [4Fe‐4S] cluster in Dph2, a key enzyme involved in the biosynthesis of diphthamide. Our calculations show that the reductive cleavage of the S−C(γ) bond is highly dependent on the electronic structure of [4Fe‐4S]. Interestingly, the six electronic states can be classified into a low‐energy and a high‐energy groups, which are correlated with the net spin of Fe4 atom ligated to SAM. Due to the driving force of Fe4−C(γ) bonding, the net spin on the Fe4 moiety dictate the shift of the opposite spin electron from the Fe1‐Fe2‐Fe3 block to SAM. Such spin‐regulated electron transfer results in the exchange‐enhanced reactivity in the lower‐energy group compared with those in the higher‐energy group. This reactivity principle provides fundamental mechanistic insights into reactivities of [4Fe‐4S] cluster in RS enzymes.
Li4MgGe2S7: The First Alkali and Alkaline‐Earth Diamond‐Like Infrared Nonlinear Optical Material with Exceptional Large Band Gap
Authors: Abudurusuli Ailijiang , Huang Junben , Wang Peng , Yang Zhihua , Pan Shilie , Li Junjie 
Published: July 2021

AbstractLarge band gap and strong nonlinear optical (NLO) effect are two valuable but contradictory parameters, which are difficult to balance in one infrared (IR) NLO material. Herein, the first alkali and alkaline‐earth metal diamond‐like (DL) IR NLO material Li4MgGe2S7, presenting a honeycomb‐like 3D framework constructed by 6‐membered LiS4 rings and GeMgS6 zigzag chains, was rationally designed and synthesized. The introduction of rigid alkali metal and alkaline‐earth metal LiS4 and MgS4 tetrahedra effectively broadens the band gap of DL compound to 4.12 eV (the largest one in the reported quaternary metal chalcogenides), generating a high laser damage threshold of 7 × AgGaS2 at 1064 nm. Furthermore, Li4MgGe2S7 displays a suitable SHG response (0.7 × AgGaS2) with a type I phase‐matching behavior. The results indicate that Li4MgGe2S7 is a promising IR NLO material for the high‐power laser application and it provides an insight into the design of new DL compound with outstanding IR NLO performances.
Programmable Site‐Specific Functionalization of DNA Origami with Polynucleotide Brushes
Authors: Yang Yunqi , Lu Qinyi , Huang Chao‐Min , Qian Hongji , Zhang Yunlong , Deshpande Sonal , Arya Gaurav , Ke Yonggang , Zauscher Stefan 
Published: July 2021

AbstractCombining surface‐initiated, TdT (terminal deoxynucleotidyl transferase) catalyzed enzymatic polymerization (SI‐TcEP) with precisely engineered DNA origami nanostructures (DONs) presents an innovative pathway for the generation of stable, polynucleotide brush‐functionalized DNA nanostructures. We demonstrate that SI‐TcEP can site‐specifically pattern DONs with brushes containing both natural and non‐natural nucleotides. The brush functionalization can be precisely controlled in terms of the location of initiation sites on the origami core and the brush height and composition. Coarse‐grained simulations predict the conformation of the brush‐functionalized DONs that agree well with the experimentally observed morphologies. We find that polynucleotide brush‐functionalization increases the nuclease resistance of DONs significantly, and that this stability can be spatially programmed through the site‐specific growth of polynucleotide brushes. The ability to site‐specifically decorate DONs with brushes of natural and non‐natural nucleotides provides access to a large range of functionalized DON architectures that would allow for further supramolecular assembly, and for potential applications in smart nanoscale delivery systems.
Regenerated cellulose/layered double hydroxide nanocomposite films with improved mechanical property
Authors: Li Gang , Hu Yang , Yang Xinfei , Yang Quanling , Tian Huafeng , Shi Zhuqun , Xiong Chuanxi 
Published: July 2021

AbstractConstruction of environment‐friendly biomass‐based nanocomposites with high performance is in great demand for developing of a sustainable low‐carbon society. Here, transparent and flexible regenerated cellulose (RC)/layered double hydroxide (LDH) nanocomposite films were prepared from aqueous NaOH/urea solutions. The obtained nanocomposite films were characterized using AFM, SEM, FTIR, XRD, tensile testing, water contact angle, and thermogravimetric analysis. The results show that LDH nanoplatelets were individually dispersed with a thickness of 1 nm and surface diameter of 100 nm after ultrasonic treatment. Strong interaction existed between LDH nanoplatelets and cellulose molecules, leading to the improved thermal stability and mechanical strength of RC together with the original good properties of LDH. In particular, the nanocomposite films with 10 wt% LDH showed a 135% and 234% increase in the tensile strength and Young's modulus than those of the neat RC film. Meanwhile, the nanocomposite films exhibited high transparency. Therefore, these RC/LDH nanocomposites are promising in the fields of high‐performance packaging materials, flexible display panels, and high‐temperature dielectric materials.
Ecdysteroids from the Aerial Parts of Paris verticillata
Authors: Jiang Peng , Liu Yan , Sun Yan‐Ping , Pan Juan , Guan Wei , Xu Zhen‐Peng , Li Xiao‐Mao , Wang Si‐Yi , Mei Yu , Kuang Hai‐Xue , Yang Bing‐You 
Published: July 2021

AbstractTwo new ecdysteroids 14‐epi‐polypodine B (1) and 22‐oxo‐hydroxyecdysterone (2), along with nine known compounds, polypodine B (3), viticosterone E (4), 20‐hdroxyecdysone‐2‐acetate (5), 22‐oxo‐20‐hydroxyecdysone (6), 5‐hydroxyecdysone (7), pinnatasterone (8), 3‐epi‐20‐hydroxyecdysone (9), ecdysterone (10) and stachysterone B (11), were isolated from the aerial parts of Paris verticillata. The structures of all compounds were elucidated by extensive spectroscopic analysis, quantum chemical calculations and ANN‐PRA/DP4+ probability analysis. Among them, the absolute configuration of compound 1 and 2 was unambiguous determined by ECD. Also, the isolated compounds were assessed for their cytotoxic activities. Compounds 2, 3 and 7 exhibited significant cytotoxic activities against PC12, LN299 and SMCC7721 cells.
Mental health‐related police incidents: Results of a national census exercise in England and Wales
Authors: Kane Eddie , Cattell Jack , Wire Julia 
Published: July 2021

AbstractBackgroundThe level of mental state incidents dealt with by police and the police resource involved is under‐researched, often giving rise to un‐evidenced claims around demand, response and resources. The 2019 National Police Chiefs' Council and College of Policing definition of such incidents provides a useful basis for more accurate calculation: ‘Any police incident thought to relate to someone's mental health where their vulnerability is at the centre of the incident or where the police have had to do something additionally or differently because of it’.AimsTo establish the nature and frequency of incidents involving the police when mental state is a primary reason for the involvement.MethodsIn this mixed methods study, we first analysed data from records in two mixed inner city/urban/rural forces and one large multi‐local authority metropolitan force. Secondly, we made an in‐depth analysis of a sample of mental state‐related incidents (n = 320) in two of these forces. Thirdly, we took a 24‐hour snapshot of all such incidents in England and Wales.ResultsMental state‐related incidents accounted for 5.1% of recorded police contacts from the public, rising to just 7.8% when confining attention only to contacts that generated a police response beyond taking the call and recording it. Length of time between an incident being reported and first response was similar between mental state‐related and non‐mental state‐related incidents, but response to closure time was shorter for the former.ConclusionsWhile incidents relating to mental state problems do consume police resources, they do not represent disproportionate demand in terms of numbers or time spent. That said, only about a quarter of the police work recorded was related to possible crimes, and the possibility of conflating perception of wider social need with mental state problems may further account for an apparent mismatch between the perceived and actual proportion of the workload spent on these incidents.
Surgical management of a delayed post‐traumatic saccular aneurysm of the radial artery
Authors: Chalidis Byron , Kitridis Dimitrios , Tirta Maria , Galanis Nikiforos , Givissis Panagiotis 
Published: July 2021

AbstractPost‐traumatic aneurysm of the radial artery is a rare and often misdiagnosed vascular lesion of the wrist. Radial artery ligation can lead to excellent results if Allen test confirmed that ulnar artery is the dominant feeding artery to the hand.
Asymmetric Transfer Hydrogenation of Aryl Heteroaryl Ketones using Noyori‐Ikariya Catalysts
Authors: Zheng Ye , Martinez‐Acosta Jaime A. , Khimji Mohammed , Barbosa Luiz C. A. , Clarkson Guy J. , Wills Martin 
Published: July 2021

AbstractA range of ketones flanked by a combination of an aromatic and a heterocyclic ring (furan, thiophene, N‐methylimidazole) were reduced under asymmetric transfer hydrogenation (ATH) conditions. Using a range of [(arene)Ru(TsDPEN)Cl] precatalysts, including tethered derivatives, the reduction enantioselectivity was high (up to 99 % ee) in cases where the aromatic ring contained an ortho‐substituent. The enantioselectivity is influenced by a combination of steric and electronic factors which for the furan and thiophene series, follow literature precedents. In the case of the N‐methylimidazole‐containing ketones, an unexpected switch in enantioselectivity took place upon variation of the opposing aromatic group. Pyrrole‐ containing ketones were resistant to reduction. This study demonstrates the asymmetric transfer hydrogenation (ATH) of a range of hindered heterocyclic ketones, in high conversion and ee, using Noyori‐Ikariya catalysts.
Selective Carbon‐Carbon Bond Amination with Redox‐Active Aminating Reagents: A Direct Approach to Anilines†
Authors: Qiu Xu , Wang Yachong , Su Lingyu , Jin Rui , Song Song , Qin Qixue , Li Junhua , Zong Baoning , Jiao Ning 
Published: July 2021

Main observation and conclusionAmines are among the most fundamental motifs in chemical synthesis, and the introduction of amine building blocks via selective C—C bond cleavage allows the construction of nitrogen compounds from simple hydrocarbons through direct skeleton modification. Herein, we report a novel method for the preparation of anilines from alkylarenes via Schmidt‐type rearrangement using redox‐active amination reagents, which are easily prepared from hydroxylamine. Primary amines and secondary amines were prepared from corresponding alkylarenes or benzyl alcohols under mild conditions. Good compatibility and valuable applications of the transformation were also displayed.
PROTOCOL: Aquaculture for improving productivity, income, nutrition and women's empowerment in low‐ and middle‐income countries: A systematic review and meta‐analysis
Authors: Gonzalez Parrao Constanza , Moratti Marta , Shisler Shannon , Snilstveit Birte , Eyers John 
Published: July 2021

AbstractThe review aims to examine and synthesise the state of the evidence around what works to improve productivity, income, nutrition and women's empowerment outcomes of households involved in aquaculture in low‐ and middle‐income countries. We are particularly interested in addressing the following research questions: (1) Do aquaculture interventions increase the productivity, income, nutrition and empowerment of individuals engaged in aquaculture and their households in low‐ and middle‐income countries? (2) Do aquaculture interventions generate income and nutrition spillover effects beyond the farmers' households? (3) To what extent do the effects of aquaculture interventions vary by intervention type, population group, and location? In particular, to what extent do effects vary by gender? (4) What are the potential barriers and facilitating factors that impact the effectiveness of aquaculture interventions? (5) What is the cost‐effectiveness of different aquaculture interventions focused on productivity, income, nutrition and empowerment outcomes?
Task migration computation offloading with low delay for mobile edge computing in vehicular networks
Authors: Qiao Bingxue , Liu Chubo , Liu Jing , Hu Yikun , Li Kenli , Li Keqin 
Published: July 2021

AbstractNowadays, a new paradigm named mobile edge computing (MEC) is capable of supplying some cloud‐like functions at the edges of wireless networks, which enables vehicles to offload the computation intensive tasks on MEC servers with low latency. However, new challenges posed by the complex network environment and the mobility of vehicles are usually not covered by traditional offloading schemes. To solve such problems, we propose a heuristic task migration computation offloading (TMCO) scheme. Compared with traditional ones, TMCO can dynamically choose suitable places to offload the tasks for moving vehicles within deadline. For this purpose, the mobility of vehicle and strict delay deadline are considered comprehensively. We use hash table to store the number of tasks on the corresponding server and use random function to simulate the probability of task offloading. In terms of latency, experimental results suggest that the performance of TMCO is on average 10% higher than that of traditional full offloading schemes.
Figure search by text in large scale digital document collections
Authors: Yurtsever M. Mücahit Enes , Özcan Muhammet , Taruz Zübeyir , Eken Süleyman , Sayar Ahmet 
Published: July 2021

SummaryDigital document collections have been created with the transfer of a large number of documents to digital media. These digital archives have provided many benefits to users. As the diversity and size of digital image collections have grown exponentially, it has become increasingly important and difficult to obtain the desired image from them. The images on the document might contain critical information about the subject of it. In this study, an architecture is developed that can work on large‐scale data by creating regular expressions together with full‐text search approaches. The performance of the system has been tested on different academic documents and Elasticsearch and Apache Solr insert times are compared. Compared to Elasticsearch, Apache Solr achieved faster and more successful results.
The evolution of marine dwelling in Diptera
Authors: Pak Nina , Wu Stephanie , Gibson Joel F. 
Published: July 2021

AbstractMarine dwelling in Diptera has been relatively unexplored and the frequency of transitions to the marine environment and the evolutionary history remain poorly understood. By reviewing records from the World Register of Marine Species and using ancestral state reconstruction methods, we build on the fly tree of life phylogeny and ecological descriptions of marine life history. Our ancestral state reconstruction analyses suggest marine dwelling is lacking as an ancestral trait for the most recent common ancestor to Diptera. While many transitions in Empidoidea, Sciomyzoidea, Tipulomorpha, and Culicomorpha seem to have been gradual, other transitions in Tephritoidea and Tabanomorpha were found likely to have been stochastic occurrences. From the collection of 532 marine species, we reveal several independent transitions to the marine environment throughout the fly tree of life. Considering the results from our analysis, we outline potential adaptations for marine flies and discuss the barriers of colonizing the marine environment and the implications to the mechanisms for salt tolerance.
No evidence of top‐down effects by ants on litter decomposition in a temperate grassland
Authors: Cates Anna M. , Wills Bill D. , Kim Tania N. , Landis Douglas A. , Gratton Claudio , Read Harry W. , Jackson Randall D. 
Published: July 2021

AbstractAnts play multiple roles in ecosystems, but their ability to affect decomposition processes in temperate grasslands is relatively unknown. We investigated whether the suppression of ant populations influenced litter decomposition in grasslands via predation of some decomposers (e.g., mites and springtails) and/or microbial activity and composition. We performed two successful ant suppression treatments (seven weeks, 37% suppression, year 1, 10 weeks, 70% suppression, year 2) over the course of a 59‐week experiment. We then assayed the effects of ant suppression using coarse‐ and fine‐mesh litterbags and evaluated litter chemistry, microbial and arthropod communities, and microbial enzyme activity. Ant suppression efforts reduced ant abundance and altered ant, arthropod decomposer, and non‐ant predator community composition. However, ant suppression did not affect decomposer arthropod abundance, litter mass loss, microbial composition, or enzyme activity in litterbags. Litterbag mesh size did not alter microbial composition, perhaps due to a failure to exclude decomposers, as mites and springtails were more or equally abundant in fine‐mesh bags. Nevertheless, mesh size did change litter chemistry, suggesting that mesh size‐mediated microenvironments affect decomposition environment regardless of invertebrate exclusion. Coarse‐mesh litterbags had higher concentrations of microbial sugars, lignin, and N and lower concentrations of litter C and crystalline cellulose than fine‐mesh litterbags. Litterbag mesh size may alter decomposition processes irrespective of invertebrate abundance. We found no evidence that ant predation was an important driver of decomposer populations or decomposition in these systems, and we suspect redundancy at the top of the detrital food web dilutes the role of ants.