bluuebunny/crossref_metadata_2025_split huggingface dataset:
M(NH2SO3)2 (M=Sr, Ba): Two Deep‐Ultraviolet Transparent Sulfamates Exhibiting Strong Second Harmonic Generation Responses and Moderate Birefringence
Authors: Hao Xia , Luo Min , Lin Chensheng , Peng Guang , Xu Feng , Ye Ning 
Published: January 2021

AbstractOver the last few decades, the development of each new nonlinear optical (NLO)‐active functional unit has led to the discoveries of a series of excellent NLO materials. In the present work, based on first‐principles studies, we identified a novel deep‐UV (DUV) NLO‐active functional unit, a non‐π‐conjugated group viz. (NH2SO3)−. By combining alkaline‐earth metals with (NH2SO3)− group, two DUV transparent NLO sulfamates, M(NH2SO3)2 (M=Sr, Ba) with superior optical properties including strong SHG responses (1.2 and 2.7 × KH2PO4 (KDP)), short UV cut‐off edge (<190 nm) and moderate birefringence (0.056@589.3 nm for Sr(NH2SO3)2) were successfully synthesized. Our work has provided not only two promising DUV transparent NLO crystals, but also an innovative non‐π‐conjugated unit for developing more DUV transparent NLO materials.
Palladium Catalyzed Cascade Azidation/Carbonylation of Aryl Halides with Sodium Azide for the Synthesis of Amides
Authors: Qi Zhuang , Li Shan‐Shan , Li Lin , Qin Qi , Yang Li‐Miao , Liang Ying‐Kang , Kang Yun , Zhang Xiang‐Zhi , Ma Ai‐Jun , Peng Jin‐Bao 
Published: January 2021

AbstractAmide synthesis is one of the most important transformations in organic chemistry due to their ubiquitous presence in our daily life. In this communication, a palladium catalyzed cascade azidation/carbonylation of aryl halides for the synthesis of amides was developed. Both iodo‐ and bromobenzene derivatives were transformed to the corresponding amides using PdCl2/xantphos as the catalyst system and sodium azide as the nitrogen‐source. The reaction proceeds via a cascade azidation/carbonylation process. A range of alkyl and halogen substituted amides were prepared in moderate to good yields.
Domain‐wise differentiation of Mycobacterium tuberculosis H37Rv hypothetical proteins: A roadmap to discover bacterial survival potentials
Authors: Beg Md Amjad , Hejazi Iram Iqbal , Thakur Sonu Chand , Athar Fareeda 
Published: January 2021

AbstractProteomic information revealed approximately 3,923 proteins in Mycobacterium tuberculosis H37Rv genome of which around ∼25% of proteins are hypothetical proteins (HPs). The present work comprises computational approaches to identify and characterize the HPs of M. tuberculosis that symbolize the putative target for rationale development of a drug or antituberculosis strategy. Proteins were primarily classified based on motif and domain information, which were further analyzed for the presence of virulence factors (VFs), determination of localization, and signal peptide/enzymatic cleavage sites. 863 HPs were found, and 599 HPs were finalized based on motifs, that is, GTP (525), Trx (47), SAM (14), PE‐PGRS (5), and CBD (8). 80 HPs contain virulence factor (VF), 24 HPs localized in membrane region, and 4 HPs contain signal peptide/enzymatic cleavage sites. The overall parametric study finalizes four HPs Rv0679c, Rv0906, Rv3627c, and Rv3811 that also comprise GTPase domain. Structure prediction, structure‐based function prediction, molecular docking and mutation analysis of selected proteins were done. Docking studies revealed that GTP and GTPase inhibitor (mac0182344) were docked with all four proteins with high affinities. In silico point mutation studies showed that substitution of aspartate with glycine within a GTPase motif showed the largest decrease in stability and pH differentiation also affects protein's stability. This analysis thus fixes a roadmap in the direction of finding potential target of this bacterium for drug development and enlightens the efficacy of GTP as a major regulator of Mycobacterial cellular pathways.
Role of neddylation in neurological development and diseases
Authors: He Xin , Zhu Ainong , Feng Jianguo , Wang Xiaobin 
Published: January 2021

AbstractNeddylation, a posttranslational protein modification, refers to the specific conjugation of NEDD8 to substrates, which is of great significance to various biological processes. Besides members of the cullin protein family, other key proteins can act as a substrate for neddylation modification, which remarkably influences neurodevelopment and neurodegenerative diseases. Normal levels of protein neddylation contribute to nerve growth, synapse strength, neurotransmission, and synaptic plasticity, whereas overactivation of protein neddylation pathways lead to apoptosis, autophagy of neurons, and tumorigenesis. Furthermore, impaired neddylation causes neurodegenerative diseases. These facts suggest that neddylation may be a target for treatment of these diseases. This review focuses on the current understanding of neddylation function in neurodevelopment as well as neurodegenerative diseases. Meanwhile, the recent view that different level of neddylation pathway may contribute to the opposing disease progression, such as neoplasms and Alzheimer's disease, is discussed. The review also discusses neddylation inhibitors, which are currently being tested in clinical trials. However, potential drawbacks of these drugs are noted, which may benefit the development of new pharmaceutical strategies in the treatment of nervous system diseases.
Novel erythropoietin‐based therapeutic candidates with extra N‐glycan sites that block hematopoiesis but preserve neuroplasticity
Authors: Bürgi Milagros , Aparicio Gabriela Inés , Dorella Aquiles , Kratje Ricardo , Scorticati Camila , Oggero Marcos 
Published: January 2021

AbstractNeurological disorders affect millions of people causing behavior‐cognitive disabilities. Nowadays they have no effective treatment. Human erythropoietin (hEPO) has been clinically used because of its neurotrophic and cytoprotective properties. However, the erythropoietic activity (EA) should be considered as a side effect. Some analogs like non‐sialylated EPO, carbamylated EPO, or EPO peptides have been developed showing different weaknesses: erythropoiesis preservation, low stability, potential immunogenicity, or fast clearance. Herein, we used a novel strategy that blocks the EA but preserves hEPO neurobiological actions. N‐glycoengineering was accomplished to add a new glycosylation site within the hEPO sequence responsible for its EA. hEPO‐derivatives were produced by CHO.K1 cells, affinity‐purified and functionally analyzed studying their in vitro and in vivo EA, their in vitro neuronal plasticity in hippocampal neurons and their neuroprotective action by rescuing hippocampal neurons from apoptosis. Muteins Mut 45_47 (K45 > N45 + N47 > T47), Mut 104 (S104 > N104), and Mut 151_153 (G151 > N151 + K153 > T153) lost their EA but preserved their neuroprotection activity and enhanced neuroplasticity more efficiently than hEPO. Interestingly, Mut 45_47 resulted in a promising candidate to explore as neurotherapeutic considering not only its biopotency but also its pharmacokinetic potential due to the hyperglycosylation.
Purification and Biological Activities of Enzymatically Degraded Sargassum fusiforme Polysaccharides
Authors: Jiang Hui , Yang Si‐Qi , Chakka Vara Prasad , Qian Wen‐Wen , Wei Xiao‐Yi , Zhu Qing , Zhou Tao 
Published: January 2021

AbstractEnzymatic hydrolysate of the crude polysaccharide (SFP) extracted from Sargassum fusiforme was purified by column DEAE‐52 and Sephadex G‐100 to yield four components, namely, ESFP1, ESFP2, ESFP3 and ESFP4. These components were characterized by chemical composition assay, GC/MS, HPGPC, UV and FT‐IR techniques. The in vitro antioxidant activities of the four purified fractions were investigated by measuring their radical scavenging activity and reducing power. The results suggested that all the four components possess good antioxidant activities. Among them, ESFP1 was found to possess the strongest 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) radical and hydroxyl radical‐scavenging activity, and the greatest ferric reducing power. The immunomodulatory effect of these four polysaccharides was demonstrated by their ability to promote proliferation, and to enhance both phagocytic activity and NO release in a macrophage RAW264.7 model. The results revealed that the bioactivities of the polysaccharides are related to their molecular weight, and the uronic acid and sulfate contents.
FlavonoidC‐Glycosyltransferases: Function, Evolutionary Relationship, Catalytic Mechanism and Protein Engineering
Authors: Dai Longhai , Hu Yumei , Chen Chun‐Chi , Ma Lixin , Guo Rey‐Ting 
Published: January 2021

AbstractC‐glycosylflavonoids are polyphenolic phytochemicals that are ubiquitously distributed in the plant kingdom and confer a wealth of health‐promoting benefits to human body. These compounds harbor one or more sugar moieties that are attached to various regions of the flavonoid scaffold through rigid C–C glycosidic bonds. The diverse structures ofC‐glycosylflavonoids are granted by the prominent reactions of flavonoidC‐glycosyltransferases (CGTs). This review gives an extensive overview of CGTs that are involved in the biosynthesis ofC‐glycosylflavonoids, focusing on their evolutionary relationship and substrate specificity. Furthermore, structural insights into the catalytic mechanism and protein engineering of flavonoid CGTs are summarized. This review provides an important guidance for identification of novel flavonoid CGTs, biosynthesis ofC‐glycosylflavonoids, and elucidation of the function‐structure relationship of flavonoid CGTs.
Dry Reforming of Methane over Ni/γ‐MgO Catalysts in a Coaxial Dielectric Barrier Discharge Reactor
Authors: Farshidrokh Zahra , Khani Mohammad Reza , Khodadadi Abbasali , Gharibi Mahtab , Shokri Babak 
Published: January 2021

AbstractDry reforming of methane (DRM) over Ni/γ‐MgO catalysts in a coaxial dielectric barrier discharge (DBD) reactor was investigated and compared with DRM without catalysts. Firstly, the catalysts Ni/MgO, Ni/5%CeO2/MgO, and Ni/7%CeO2/MgO were prepared, their characteristics were specified by X‐ray diffraction, and then, they were partially packed into the DBD reactor. Various parameters such as the discharge power, flow rate, and CH4/CO2 molar ratio were explored. The presence of catalysts in the plasma reactor increased the yield and selectivity of H2 and CO. Furthermore, the effect of a reduced catalyst (Ni/7%CeO2/MgO reduced in argon‐hydrogen plasma) was evaluated, showing that CH4 can be converted with activated catalyst without extra power. Activated Ni/7%CeO2/MgO alone was able to convert CH4 to over 99 % for 30 min after reduction.
Controllable chiral behavior of type‐II core/shell quantum dots adjusted by shell thickness and coordinated ligands
Authors: Shao Xiao , Zhang Tianyong , Li Bin , Wu Yue , Li Siyi , Wang Jingchao , Jiang Shuang 
Published: January 2021

AbstractChiral semiconductor nanomaterials induced by capped chiral ligands are of great interest for both theoretical studies and advanced applications. In this study, CdTe/CdSe quantum dots (QDs), defined as type‐II core/shell nanostructure, with the advantage of a good separation of holes and electrons are imparted chirality with L/D‐cysteine and L/D‐penicillamine molecules. Circular dichroism (CD) at exciton transitions from cysteine‐ and penicillamine‐capped QDs is different in shape and intensity. CD intensities decrease with increasing shell thickness from three monolayers to six monolayers, indicating a decreased hybridization degree between the holes in CdTe core and the electrons in chiral ligands. Elevated cysteine concentration leads to decreased g‐factor, probably due to an altered binding mode from tridentate to bidentate. Our observations provide further insights into the understanding of chiral phenomenon as well as optimized design and applications of chiral nanostructures.
Pyrolysis kinetics and activation thermodynamic parameters of exhausted coffee residue and coffee husk using thermogravimetric analysis
Authors: Mukherjee Alivia , Okolie Jude A. , Tyagi Ramani , Dalai Ajay K. , Niu Catherine 
Published: January 2021

AbstractExhausted coffee residue (ECR) and coffee husk (CH) are potential feedstock for energy production through thermochemical and biochemical conversion processes. Kinetic study of ECR and CH is essential for the design and optimization of different thermochemical conversion processes. In this study, four different iso‐conversional methods were employed in the estimation of the activation energy (EA) and pre‐exponential factor (A). The methods used includes Flynn‐Wall‐Ozawa (FWO), Kissinger‐Akahira‐Sunose (KAS), Kissinger's method, and the Friedman method. Data from the thermogravimetric/derivative thermogravimetric analysis (TGA/DTG) at varying heating rates of 5‐20°C/min in an inert environment were used in this study. It was observed that the heating rate influences the pyrolysis parameters such as peak temperature, maximum degradation rate and initial decomposition temperature. The activation energy for ECR using the FWO method was in the range of 62.3‐102.4 kJ · mol−1. Likewise, the KAS and Friedman methods yielded activation energy between 51.3‐93.3 kJ · mol−1 and 10.6‐122.7 kJ · mol−1, respectively. In addition, the activation energy calculated for CH using FWO, KAS, and Friedman methods were shown to range from 39.1‐140.6 kJ · mol−1, 27.7‐131.6 kJ · mol−1, and 24.9‐111.2 kJ · mol−1, respectively.
Do Drug‐likeness Rules Apply to Oral Prodrugs?
Authors: Protti Ícaro F. , Rodrigues Daniel R. , Fonseca Sofia K. , Alves Ricardo J. , de Oliveira Renata B. , Maltarollo Vinícius G. 
Published: January 2021

AbstractThis paper describes a comparative analysis of the physicochemical and structural properties of prodrugs and their corresponding drugs with regard to drug‐likeness rules. The dataset used in this work was obtained from the DrugBank. Sixty‐five pairs of prodrugs/drugs were retrieved and divided into the following categories: carrier‐linked to increase hydrophilic character, carrier‐linked to increase absorption, and bioprecursors. We compared the physicochemical properties related to drug‐likeness between prodrugs and drugs. Our results show that prodrugs do not always follow Lipinski's Rule of 5, especially as we observed 15 prodrugs with more than 10 hydrogen bond acceptors and 18 with a molecular weight greater than 500 Da. This fact highlights the importance of extending Lipinski's rules to encompass other parameters as both strategies (filtering of drug‐like chemical libraries and prodrug design) aim to improve the bioavailability of compounds. Therefore, critical reasoning is fundamental to determine whether a structure has drug‐like properties or could be considered a potential orally active compound in the drug‐design pipeline.
CAM20u: An extension of CAM16 for predicting the color appearance of unrelated colors
Authors: Gao Cheng , Li Changjun , Shi Keyu , Luo Ming R. , Pointer Michael R. 
Published: January 2021

AbstractA comprehensive color appearance model should be capable of predicting color appearance under a wide range of viewing conditions, including related and unrelated colors. The current CAM16 model was designed to predict the appearance of related colors and is in the process of becoming a CIE recommendation, to replace the current CIECAM02 model. This article describes an extension of CAM16 (named CAM20u) for predicting the brightness, hue quadrature, amount‐of‐white, and colorfulness attributes of unrelated colors. Its performance, together with that of other unrelated models, was tested based on the three available datasets. The results show that the CAM20u model significantly outperforms the others, especially for colorfulness and amount‐of‐white.
A brief acceptance and commitment intervention for work‐related stress and burnout amongst frontline homelessness staff: A single case experimental design series
Authors: Reeve Andy , Moghaddam Nima , Tickle Anna , Young Dave 
Published: January 2021

AbstractPurposeRecent intervention research for burnout amongst those working in health and social care contexts has found acceptance and commitment therapy (ACT) interventions to be of use but has provided less clarity on the role of psychological flexibility (a key ACT construct). This study further evaluated the usefulness of ACT for burnout and work‐engagement and assessed the role of psychological flexibility in contributing to therapeutic change.ProcedureA nonconcurrent multiple‐baseline across‐participants single‐case experimental design was used. Four participants were recruited from a homelessness organization in the East Midlands, England. The ACT‐intervention was split into three modules to reflect the three aspects of the ACT triflex, and the sequence of delivery was randomized for each participant in order to test the relationship between these aspects.FindingsSupport was found for the ACT intervention reducing exhaustion and increasing work‐engagement. Psychological Flexibility increased in all participants and was temporally related to increases in other outcome variables in some instances. Delivery of the intervention focussed on any given aspect of the ACT triflex could increase different domains of psychological flexibility.ImplicationsThis study adds to the growing body of research in favour of ACT interventions for burnout and adds to the understanding of psychological flexibility as a mediating variable.
Deuterium‐tritium fuel impact ignition in the presence of degenerate plasma
Authors: Pourhosseini Seddigheh , Ghasemizad Abbas , Rezaei Somayeh , Jafari Mohammad J. 
Published: January 2021

AbstractThe impact ignition model is proposed based on the collision of a deuterium‐tritium (DT) layer accelerated to high velocities in a conical target. Simple mechanism, low cost, high coupling efficiency, and lack of the need for Petawatt laser pulses are the prominent advantages of this model. However, an increase in the productivity of this ignition mechanism is an important issue. In this regard, in this paper, the idea of impact ignition using the plasma degeneracy mechanism has been investigated. For this purpose, first, the ignition energy gain and stopping power of the DT beam in pure and impure fuels, by employing both degenerate and non‐degenerate plasmas, have been examined numerically. Then, in order to assess the penetration depth and range of the incident beam, simulations have been carried out using a three‐dimensional (3D) Monte Carlo code for two states of degenerate and non‐degenerate pre‐compressed pure fuel. The results imply that the state of degeneracy causes an increase by about 63% in the energy gain of impact ignition. In addition, the degeneracy condition leads to an approximate enhancement of 60% in the energy deposition of the pure fuel and about 67% for the impure fuel, with a mixed density ratio of 1.5%; therefore, the range and penetration depth decrease significantly in comparison to the non‐degenerate one. This can be indicative of the increasing efficiency of impact ignition conditions in the presence of degenerate plasma. The results of the range for the pure fuel have also been confirmed by a 3D Monte Carlo simulation code.
Graph traversal aided detection in uplink MBM massive MIMO based on socio‐cognitive knowledge of swarm optimization
Authors: Datta Arijit , Bhatia Vimal , Mandloi Manish , Panda Ganapati 
Published: January 2021

SummaryMedia‐based modulation (MBM) plays a crucial role in enhancing the spectral efficiency and energy efficiency of massive MIMO (mMIMO) systems for 5G and beyond wireless communications. In MBM, multiple parasitic elements, also termed as radio frequency (RF) mirrors, are placed near the transmit antennas for generating different channel fade realizations. These realizations are obtained by ON/OFF switching of RF mirrors. One of those channel fade realizations is selected (using a part of the incoming information bits) for transmitting a part of the information bits utilizing a symbol chosen from the conventional constellation set (using another part of the incoming information bits). Transmission of a symbol through one of the available channel realizations constitutes a sparse transmit vector for each user in MBM‐mMIMO. The sparse nature of transmitted symbols from multiple users and inter‐user interference makes the symbol detection in uplink MBM‐mMIMO challenging. Therefore, in this article, the problem of symbol detection in MBM‐mMIMO is analyzed from a graph‐theoretical point of view, and a graph‐traversal aided low‐complexity symbol detection algorithm is proposed inspired by socio‐cognitive learning of swarm optimization. Also, the convergence characteristic of the proposed technique is investigated theoretically. Further, an analytical expression of upper bound on bit error rate performance is derived and corroborated through simulations. Viability and robustness of the proposed technique are also justified through simulations over state‐of‐art detection techniques, under both perfect and imperfect channel state information scenarios.
The population genetics of nonmigratory Allen’s Hummingbird (Selasphorus sasin sedentarius) following a recent mainland colonization
Authors: Myers Brian M. , Burns Kevin J. , Clark Christopher J. , Brelsford Alan 
Published: January 2021

AbstractAllen's Hummingbird comprises two subspecies, one migratory (Selasphorus sasin sasin) and one nonmigratory (S. s. sedentarius). The nonmigratory subspecies, previously endemic to the California Channel Islands, apparently colonized the California mainland on the Palos Verdes Peninsula some time before 1970 and now breeds throughout coastal southern California. We sequenced and compared populations of mainland nonmigratory Allen's Hummingbird to Channel Island populations from Santa Catalina, San Clemente, and Santa Cruz Island. We found no evidence of founder effects on the mainland population. Values of nucleotide diversity on the mainland were higher than on the Channel Islands. There were low levels of divergence between the Channel Islands and the mainland, and Santa Cruz Island was the most genetically distinct. Ecological niche models showed that rainfall and temperature variables on the Channel Islands are similar in the Los Angeles basin and predicted continued expansion of nonmigratory Allen's Hummingbird north along the coast and inland. We also reviewed previous genetic studies of vertebrate species found on the Channel Islands and mainland and showed that broad conclusions regarding island–mainland patterns remain elusive. Challenges include the idiosyncratic nature of colonization itself as well as the lack of a comprehensive approach that incorporates similar markers and sampling strategies across taxa, which, within the context of a comparative study of island–mainland relationships, may lead to inconsistent results.