bluuebunny/crossref_metadata_2025_split huggingface dataset:
How Ionization Catalyzes Diels‐Alder Reactions
Authors: Vermeeren Pascal , Hamlin Trevor A. , Bickelhaupt F. Matthias 
Published: April 2022

AbstractThe catalytic effect of ionization on the Diels‐Alder reaction between 1,3‐butadiene and acrylaldehyde has been studied using relativistic density functional theory (DFT). Removal of an electron from the dienophile, acrylaldehyde, significantly accelerates the Diels‐Alder reaction and shifts the reaction mechanism from concerted asynchronous for the neutral Diels‐Alder reaction to stepwise for the radical‐cation Diels‐Alder reaction. Our detailed activation strain and Kohn‐Sham molecular orbital analyses reveal how ionization of the dienophile enhances the Diels‐Alder reactivity via two mechanisms: (i) by amplifying the asymmetry in the dienophile's occupied π‐orbitals to such an extent that the reaction goes from concerted asynchronous to stepwise and thus with substantially less steric (Pauli) repulsion per reaction step; (ii) by enhancing the stabilizing orbital interactions that result from the ability of the singly occupied molecular orbital of the radical‐cation dienophile to engage in an additional three‐electron bonding interaction with the highest occupied molecular orbital of the diene.
Electrochemical Synthesis of Sulfonyl Fluorides with Triethylamine Hydrofluoride
Authors: Zhang Lei , Cheng Xu , Zhou Qi‐Lin 
Published: April 2022

Comprehensive SummaryHydrofluoride is an industry‐preferred fluoride source, and finds extensively application to manufacture diverse fluoro chemicals. The Et3N‐3HF complex is a liquid HF with improve safety. In this work, we report electrochemical synthesis of a series of sulfonyl fluoride with Et3N‐3HF as fluoride source. The sulfinic salt is a smell‐less, non‐volatile, and air‐stable sulfur source in this reaction. With the combination of Et3N‐3HF and aryl/alkyl sulfinic salt, the sulfonyl fluorides are achieved without the use of external oxidant. In addition, we demonstrate further advantage in a tandem reaction involving Pd‐catalyzed C—S cross‐coupling and formation of S—F bond. A variety of functional groups including amino acids, heterocycles, halides are well tolerated.
Direct and indirect costs of allergic and non‐allergic rhinitis to adults in Beijing, China
Authors: Li Xian , Xu Xu , Li Jingyun , Huang Yanran , Wang Chengshuo , Zhang Yuan , Zhang Luo 
Published: April 2022

AbstractBackgroundChronic rhinitis is generally classified as either allergic rhinitis (AR) or non‐allergic rhinitis (NAR). There is currently no report on the economic burden of AR and NAR in Beijing, China.MethodologyA total of 1013 valid questionnaires from 448 AR patients and 565 NAR patients living in Beijing were continuously collected for investigation of the direct (e.g., drugs, medical visits) and indirect costs (absenteeism and presenteeism) from August 2020 to April 2021.Results and ConclusionThe total cost of AR and NAR was € 195.6 patient/year and € 185.3 patient/year respectively. The total societal cost for adult AR and NAR patients in Beijing is around € 440.9 and € 671.9 million per year in terms of the standardized prevalence of the diseases. The patient's level of education, disease duration, predilection time of disease, severity of symptoms and comorbidity with other allergic disease were factors that affected the economic burden on patients with rhinitis.
New Insights into the Catalytic Decomposition of Ammonium Perchlorate and Decomposition Mechanism by Nano‐CuO Dispersed in Graphite‐Carbon Nitride Nanosheet Composites
Authors: Shi Zhe , Tang Changsheng , Xu Yidong , Hu Yinghui , Zhang Jian , Zhu Zhaoyang , Zheng Jian , Fan Ruiqing , Xia Debin , Yang Yulin 
Published: April 2022

AbstractEnhancing the exothermic decomposition of ammonium perchlorate (AP) is of great significance to obtain solid propellants with excellent combustion performance. Herein, we prepared a series of composites for catalyzing the exothermic decomposition of AP by a facile method with different masses of nano copper oxide (n‐CuO) dispersed in graphene‐nitride carbon (g‐C3N4) nanosheets. Among them, n‐CuO‐8/g‐C3N4showed the best catalytic activity, which reduced the high‐temperature decomposition (HTD) value by 95.0 °C, and increased the total heat release by 505 J ⋅ g−1. The n‐CuO‐12/g‐C3N4also reduced the activation energy (Ea) of the HTD stage by 47.34 kJ ⋅ mol−1. The catalytic mechanism study suggested that the n‐CuO‐X/g‐C3N4composites promoted the transition of electrons (e−) and holes (h+) from ClO4−to NH4+and inhibited the recombination of e−and h+, which further enhanced the exothermic decomposition of AP. During decomposition, the transformation of N2O to NO was significantly inhibited by the n‐CuO‐X/g‐C3N4composites, thus increasing the integral heat release as evidenced by Real‐time thermogravimetry/Fourier transform infrared spectroscopy. This study illustrated that n‐CuO‐X/g‐C3N4composites are catalysts for the efficient decomposition of AP, which further enhance the energy performance of solid propellants.
Developing robust ridge estimators for Poisson regression model
Authors: Abonazel Mohamed R. , Dawoud Issam 
Published: April 2022

AbstractThe Poisson regression model (PRM) is the standard statistical method of analyzing count data, and it is estimated by a Poisson maximum likelihood (PML) estimator. Such an estimator is affected by outliers, and some robust Poisson regression estimators have been proposed to solve this problem. PML estimators are also influenced by multicollinearity. Biased Poisson regression estimators have been developed to address this problem, including Poisson ridge regression and Poisson almost unbiased ridge estimators. However, the above mentioned estimators do not deal with outliers and multicollinearity problems together in a PRM. Therefore, we propose two robust ridge estimators to deal with the two problems simultaneously in the PRM, namely, the robust Poisson ridge regression (RPRR) estimator and the robust Poisson almost unbiased ridge (RPAUR) estimator. Theoretical comparisons and Monte‐Carlo simulations are conducted to investigate the performance of the proposed estimators relative to the performance of other approaches to PRM parameter estimation. The simulation results indicate that the RPAUR estimator outperforms the other estimators in all situations where both problems exist. Finally, real data are used to confirm the results of this paper.
Uncertainty Quantification of Reactivity Scales
Authors: Proppe Jonny , Kircher Johannes 
Published: April 2022

AbstractThe front cover artwork is provided by Prof. Ricardo A. Mata from the University of Göttingen. The image contrasts single‐valued reactivity parameters and distributions thereof. The latter allow chemists to better assess relative reactivity and, therefore, support synthesis planning. Read the full text of the Research Article at 10.1002/cphc.202200061.
Advances in Electrochemiluminescence Biosensors Based on DNA Walkers
Authors: Zhao Li‐Dan , Yang Xia , Zhong Xia , Zhuo Ying 
Published: April 2022

AbstractMediated by Watson‐Crick base‐pairing principle, DNA can be used to construct multi‐functional molecular machines, such as DNA walkers, tweezers, logic gates and motors. It is noteworthy that DNA walkers with the advantages of programmability and diverse structures within the micro‐nano scale have attracted intense attention in the field of biosensing, bioimaging, drug delivery, and genetic diagnosis. DNA walkers are comprised of driving power, walking strands and the tracks. The driving power acts as an external stimulus and the tracks as a platform for the walking strands to move autonomously. Under the specific external stimulus as driving power, such as strand displacement strategies, enzymatic reactions and environmental condition stimulus, DNA walkers could realize the generation and amplification of signals. Electrochemiluminescence (ECL) biosensors, combining ECL technology and bio‐identification strategies, exhibit the virtue of high sensitivity, wide linear response range and low background interference. Recently, the construction of DNA walker‐based ECL biosensors can amplify the targets and signals via multiple identification and recycles, achieving ultrasensitive detection for diverse targets. Herein, this review systematically summarizes the construction of different types of DNA walkers and their applications in ECL biosensors. Ultimately, this review summarizes and discusses the prospects for DNA walkers.
Rational Molecular Design of Efficient Heavy‐Atom‐Free Photosensitizers for Cancer Photodynamic Therapy
Authors: Nguyen Van‐Nghia , Ha Jeongsun , Jeong Hyunsun , Cho Moonyeon , Kim Gyongmi , Yoon Juyoung 
Published: April 2022

AbstractPhotodynamic therapy has emerged as a promising modality for treatment of cancer due to its minimal invasiveness and high selectivity. However, development of advanced photosensitizers (PSs) for clinical translation of photodynamic therapy remains challenging. To overcome the limitations of common photosensitizers containing heavy atoms, we herein developed highly effective heavy‐atom‐free photosensitizers based on strong donor‐π‐acceptor‐type structures (PTZ‐CN and PXZ‐CN) for bioimaging and photodynamic ablation of cancer. These PSs exhibited bright fluorescence emission with a large Stokes shift as well as considerable reactive oxygen generation capability under specific conditions. Notably, PTZ‐CN could produce reactive oxygen species more efficiently than Ru(bpy)32+ (commercial PS) with an approximately 2.2‐fold via type I and type II photochemical mechanisms. In addition, their stable nanoparticles were easily formed by self‐assembly in an aqueous solution without employing a polymer. More importantly, PTZ‐CN/PXZ‐CN exhibited bright fluorescence and excellent photodynamic performance with negligible dark cytotoxicity toward HeLa cells. This study demonstrates the promising potential of donor‐π‐acceptor‐type molecule‐based PSs in fluorescence image‐guided photodynamic therapy.
Novel 3D printing method to reinforce implant‐supported denture fiberglass as material for implant prosthesis: A pilot study
Authors: Nicali Andrea , Pradal Giulia , Brandolini Gianluca , Mantelli Andrea , Levi Marinella 
Published: April 2022

AbstractObjectivesDespite a large amount of materials and methods to make an implant‐supported denture, nowadays there is no gold standard. Every solution has pros and cons that guide the clinician and the technician to choose the best solution for a single case. The aim of this study was to evaluate the mechanical characteristics of the fiber‐reinforced composite superstructure made by using a novel three‐dimensional (3D) printing technology able to create a reinforcing structure patient‐specific, more reliable, structurally optimized, and faster than conventional methods.Materials and MethodsTo evaluate mechanical performances of 3D‐printed fiberglass, mechanical characterization of 3D‐printed material was performed. Before proceeding with the realization of the final prosthesis, five specimens were created on which the tensile test and volumetric fiber content measurement were performed. Then denture reinforcement 3D printing process began. Initially, the robot prints layers of fiber. Finally, the obtained 3D‐printed reinforcement structure was finalized in the lab.ResultsThe prosthesis obtained through this process was lighter than a traditional prosthesis, there was a greater chemical adhesion between resin and 3D‐printed reinforcement structure and a better result was obtained from an esthetic point of view.ConclusionsThe outcomes we obtained endorse its performance both mechanical and esthetic. The entire process is automatic and does not require human operation thanks to specific software programming.
Development and validation of diagnostic markers for the wheat Fusarium head blight resistance gene Fhb7
Authors: Zhao Lanfei , Ge Wenyang , Lyu Zhongfan , Xu Shoushen , Xu Yuzhou , Bernardo Amy , Zhang Qijun , Xu Steven , Wang Hongwei , Kong Lingrang , Bai Guihua 
Published: April 2022

AbstractFusarium head blight (FHB), mainly incited by Fusarium graminearum Schwabe, has caused great losses in grain yield and quality of wheat globally. Fhb7, a gene with a major effect on FHB resistance, was recently cloned and shown to be a GST encoding glutathione S‐transferase. Fhb7 originated from the 7E chromosome of Thinopyrum ponticum and confers broad resistance to Fusarium species. However, high‐throughput diagnostic markers are not available for wider deployment of Fhb7 in breeding programs. To develop such DNA markers for high‐throughput screening of Fhb7, we designed two kompetitive allele specific polymerase chain reaction (KASP) markers (Fhb7‐KASP1 and Fhb7‐KASP2) based on the promoter and coding sequences of GST homologs and tested their cosegregation with Fhb7 FHB resistance in a recombinant inbred population. As a validation of their usefulness in marker‐assisted selection in breeding programs, Fhb7‐KASP1 and Fhb7‐KASP2 were shown to be diagnostic for Fhb7 status in a set of RWG34‐near‐isogenic lines (NILs) and a natural winter wheat population (RGON2020). Haplotype analysis of Thinopyrum accessions using the two markers and GST homolog sequences identified only six accessions with the Fhb7 resistance marker alleles and the Hap I‐R haplotype, and five of them were cytologically confirmed to be Th. ponticum, the species in which Fhb7 was originally identified. The development of the diagnostic markers in this study will facilitate the deployment of Fhb7 in wheat breeding programs to improve FHB resistance.
Enhancing the learning of evolutionary anthropology skills by combining student‐active teaching with actual and virtual immersion of Master's students in fieldwork, laboratory practice, and dissemination
Authors: Bayle Priscilla , Armand Dominique , Bessou Maryelle , Cochard David , Couture Christine , Deguilloux Marie‐France , Ferrier Catherine , Haget Cathy , Jaubert Jacques , Knüsel Christopher , Martins Stéphanie , Pubert Éric , Rottier Stéphane , Souron Antoine , Beauval Cédric , Caillo Arnaud , Dutailly Bruno , Girault Thomas , Hesry Malo , Lacrampe‐Cuyaubère François , Ledevin Ronan , Masset Caroline , Mesa‐Saborido Miriam , Mora Pascal , Muth Xavier , Pinson Raphaël , Thibeault Adrien , Thomas Marc , Vanderesse Nicolas , Bordes Jean‐Guillaume 
Published: April 2022

AbstractHigher education in evolutionary anthropology involves providing students with in‐depth knowledge of biological and cultural heritage sites and collections that are frequently inaccessible. Indeed, most sites, fossils, and archaeological remains can be visited or manipulated only rarely and solely by specialists with extensive experience. Owing to the development of 3D and medical imaging techniques, this fragile heritage is now more widely accessible, and in a dynamic way. However, exclusive adoption of virtual teaching and learning has a negative impact on student engagement and, naturally, on exchanges with instructors, and thus cannot be used without some reservations. In the ITAP (Immersion dans les Terrains de l’Anthropologie biologique et de la Préhistoire) project of the higher education STEP (Soutien à la Transformation et à l’Expérimentation Pédagogiques) transformation program at the University of Bordeaux, we combine student‐active teaching with Master's students fully immersed in ongoing fieldwork, laboratory study, and dissemination of research results in order to develop more individually shaped learning curricula and to foster both professional and new interdisciplinary skills. Here, we present examples of experiments conducted in the ITAP project using both authentic and virtual collections of archaeological, experimental, and reference materials that help to break down the barriers between research activities and higher education, as well as providing a more general appraisal of the appropriate use of virtual tools in higher education by combining them with real‐life situations.
Conservation and management of the culture of bears
Authors: Servheen Christopher , Gunther Kerry A. 
Published: April 2022

AbstractCulture is widely accepted as an important social factor present across a wide range of species. Bears have a culture as defined as behavioral traditions inherited through social learning usually from mothers to offspring. Successful bear cultures can enhance fitness and resource exploitation benefits. In contrast, some bear cultures related to response to humans and human‐related foods can be maladaptive and result in reduced fitness and direct mortality. In environments with minimal human influence most bear culture has evolved over generations to be beneficial and well adapted to enhance fitness. However, most bears across the world do not live in areas with minimal human influence and in these areas, bear culture is often changed by bear interactions with humans, usually to the detriment of bear survival. We highlight the importance of identifying unique bear cultural traits that allow efficient use of local resources and the value of careful management to preserve these adaptive cultural behaviors. It is also important to select against maladaptive cultural behaviors that are usually related to humans in order to reduce human–bear conflicts and high bear mortality. We use examples from Yellowstone National Park to demonstrate how long‐term management to reduce maladaptive bear cultures related to humans has resulted in healthy bear populations and a low level of human–bear conflict in spite of a high number of Yellowstone National Park visitors in close association with bears.
Applying and testing a novel method to estimate animal density from motion‐triggered cameras
Authors: Becker Marcus , Huggard David J. , Dickie Melanie , Warbington Camille , Schieck Jim , Herdman Emily , Serrouya Robert , Boutin Stan 
Published: April 2022

AbstractEstimating animal abundance and density are fundamental goals of many wildlife monitoring programs. Camera trapping has become an increasingly popular tool to achieve these monitoring goals due to recent advances in modeling approaches and the capacity to simultaneously collect data on multiple species. However, estimating the density of unmarked populations continues to be problematic due to the difficulty in implementing complex modeling approaches, low precision of estimates, and absence of rigor in testing of model assumptions and their influence on results. Here, we describe a novel approach that uses still image camera traps to estimate animal density without the need for individual identification, based on the time spent in front of the camera (TIFC). Using results from a large‐scale multispecies monitoring program with nearly 3000 cameras deployed over 6 years in Alberta, Canada, we provide a reproducible methodology to estimate parameters and we test key assumptions of the TIFC model. We compare moose (Alces alces) density estimates from aerial surveys and TIFC, including incorporating correction factors for known TIFC assumption violations. The resulting corrected TIFC density estimates are comparable to aerial density estimates. We discuss the limitations of the TIFC method and areas needing further investigation, including the need for long‐term monitoring of assumption violations and the number of cameras necessary to provide precise estimates. Despite the challenges of assumption violations and high measurement error, cameras and the TIFC method can provide useful alternative or complementary animal density estimates for multispecies monitoring when compared to traditional monitoring methods.
NLRP3 inflammasome triggers interleukin‐37 release from human monocytes
Authors: Gritsenko Anna , Díaz‐Pino Rodrigo , López‐Castejón Gloria 
Published: April 2022

AbstractIL‐37 is an anti‐inflammatory member of the IL‐1 family that dampens inflammation associated with many noncommunicable diseases. However, mechanisms of IL‐37 regulation remain understudied. We aimed to investigate the enzymatic cleavage of IL‐37 that potentiates extracellular signalling, as well as pathways of IL‐37 secretion. In human monocytes, mature IL‐37 (mIL‐37) was released following canonical NLRP3 inflammasome activation. The release of IL‐37 was blocked by inhibiting plasma membrane permeability and in gasdermin‐D‐deficient THP‐1 cells. While the cleavage of IL‐37 was found to be constitutive, the release of mIL‐37 was blocked in NLRP3‐deficient THP‐1 cells and by NLRP3 inhibitor MCC950 in THP‐1s and primary human monocytes. IL‐37 secretion also occurred after 18‐h exposure to LPS, independently of the alternative NLRP3 inflammasome. This LPS‐dependent IL‐37 secretion required plasma membrane permeability, but not conventional protein secretion apparatus. Mutagenesis of the suggested caspase‐1 cleavage site (D20) or the proposed alternative cleavage site (V46) did not completely block IL‐37 processing. Therefore, we propose a novel pathway in which IL‐37 is cleaved by caspase‐1‐independent mechanisms and released following canonical and alternative NLRP3 inflammasome triggers by differential pathways.
Exporting Homogeneous Transition Metal Catalysts to Biological Habitats
Authors: Seoane Andrés , Mascareñas José Luis 
Published: April 2022

AbstractThe possibility of performing designed transition‐metal catalyzed reactions in biological and living contexts can open unprecedented opportunities to interrogate and interfere with biology. However, the task is far from obvious, in part because of the presumed incompatibly between organometallic chemistry and complex aqueous environments. Nonetheless, in the past decade there has been a steady progress in this research area, and several transition‐metal (TM)‐catalyzed bioorthogonal and biocompatible reactions have been developed. These reactions encompass a wide range of mechanistic profiles, which are very different from those used by natural metalloenzymes. Herein we present a summary of the latest progress in the field of TM‐catalyzed bioorthogonal reactions, with a special focus on those triggered by activation of multiple carbon‐carbon bonds.
Nickel/Photo‐Cocatalyzed Acyl C−H Benzylation of Aldehydes with Benzyl Chlorides
Authors: Li Xiantang , Mao Yujia , Fan Pei , Wang Chuan 
Published: April 2022

AbstractWe have developed a nickel/TBADT cocatalyzed acyl C−H benzylation of both aliphatic and aromatic aldehydes with primary and secondary benzyl chlorides under mild reaction conditions. The protocol provides a convenient and efficient method to synthesize a variety of ketones.
C−H Hydroxylation of Quinoxalin‐2(1H)‐ones through ipso‐Substitution Using tert‐Butyl Nitrite
Authors: Sau Sudip , Mal Prasenjit 
Published: April 2022

AbstractA convenient one‐pot synthesis of quinoxaline‐2,3‐dione has been achieved by C−H hydroxylation of quinoxalin‐2(1H)‐one using TBN (tert‐butyl nitrite) as a promoter of the reaction in DMSO. First radical‐mediated nitration using TBN at C‐3 of quinoxalin‐2(1H)‐one and followed by hydroxylation with water via ipso‐substitution led to the quinoxaline‐2,3‐dione.