bluuebunny/crossref_metadata_2025_split huggingface dataset:
Enantioselective Nickel‐Catalyzed Electrochemical Radical Allylation
Authors: Zhang Qinglin , Liang Kang , Guo Chang 
Published: August 2022

AbstractA simplified and appealing strategy via a chiral catalyst to facilitate the electrochemical process and provide asymmetric induction of radical reactions is particularly desirable and would have potential applications in electrosynthesis, organic chemistry, and drug discovery. Here, we introduced a novel electrolytic system that diverts the standard ionic reactivity to new catalytic functions, enabling mechanistically distinct single‐electron transfer‐based enantioselective routes to exhibit a brand‐new pattern of reactivity—electricity‐driven asymmetric catalysis as a privileged chiral platform for enantioselective radical allylation. The nickel‐catalyzed activation of nucleophiles triggered a single‐electron transfer process to provide a chiral catalyst‐bound radical cation intermediate, which could be applied as an alternative strategy for the development of stereocontrolled radical reactions.
Dynamic Evolution of Aluminum Coordination Environments in Mordenite Zeolite and Their Role in the Dimethyl Ether (DME) Carbonylation Reaction
Authors: Liu Rongsheng , Fan Benhan , Zhi Yuchun , Liu Chong , Xu Shutao , Yu Zhengxi , Liu Zhongmin 
Published: August 2022

AbstractPart of tetrahedral framework aluminum in a protonic mordenite (HMOR) will convert geometry to distorted tetrahedral and octahedral coordination. High‐field 27Al NMR data show that more framework Al atoms at T3 and T4 sites change geometry to nonframework structures than others. These nonframework Al species preferentially reside in the side pockets, which will decrease the accessibility of acid sites in the 8‐membered ring (MR) channel, impairing the dimethyl ether (DME) carbonylation reaction. The arisen octahedrally coordinated Al species are framework‐associated, which can be reverted into the zeolite framework. Herein, we find that a facile treatment with pyridine could force the octahedral coordination Al back into a tetrahedral environment, which could increase the number of available active sites and enhance the diffusion of DME, thus improving the reactivity (4 times) of the DME carbonylation reaction and prolonging the lifetime of catalysts.
Noble‐metal free Suzuki–Miyaura reaction catalyzed by magnetically recyclable MOF composites
Authors: Sun Zhong‐Hua , Chen Wang , Wang Le‐Yao , Wang Liang , Tang Yi‐Han , Qian Bin‐Bin , He Ming‐Yang , Chen Qun , Zhang Zhi‐Hui 
Published: August 2022

An effective metal–organic frameworks composite, Cu‐BTC@Fe3O4, was applied to catalyze Suzuki–Miyaura reaction under mild conditions and could achieve a good yield up to 98%. This magnetic noble‐metal free catalyst was proved excellent reusability for at least four cycles without loss of catalytic activity and crystallinity. X‐ray photoelectron spectroscopy confirmed that the binding energy of Fe‐2p shifted to a negative value by 0.3 eV in Cu‐BTC@Fe3O4 after catalysis; in the meantime, the binding energy of Cu‐2p shifted to a positive value by 0.1 eV. A possible bimetallic catalytic mechanism involved in this coupling reaction was proposed. In addition, the heterogeneous and recyclable properties of the catalyst were shown by hot filtration experiments, and the catalyst can be easily separated from reaction system in the presence of magnetic field.
The development of an unexpected Cu(I)‐pyrazolo pyrimidine‐based complex: Synthesis, spectroscopic characterizations, and biological activity
Authors: Elbadawy Hemmat A. , Abd‐El‐Nabey Bashir A. , Ali Ali El‐Dissouky , Elsayed Eman Hassan 
Published: August 2022

A novel unexpected pyrazolo[1,5‐a]pyrimidine‐based Cu(I) complex, [Cu (DQPC)2]ClO4, has been synthesized by reaction of 2,7‐diamino‐5‐phenyl‐3‐(phenyldiazenyl)pyrazolo[1,5‐a]pyrimidine‐6‐carbonitrile (DQPC) and Cu (ClO4)2.6H2O in ethanol. Full characterizations of [Cu (DQPC)2]ClO4 are achieved via CHNCu‐analyses, Ʌm calculation, spectroscopic techniques, and confirmed unambiguously by single crystal X‐ray diffraction. The crystallographic data revealed a distorted tetrahedral environment around the Cu(I) center in the inner sphere, where the (DQPC) acted as a neutral bidentate ligand, while one perchlorate ion, in the outer sphere. [Cu (DQPC)2]ClO4 and DQPC have been screened against six pathogenic microorganisms and breast carcinoma human cancer cell lines (MCF‐7). The data revealed high anti‐bacterial, anti‐fungal, and interesting cytotoxic activities. Furthermore, [Cu (DQPC)2]ClO4 showed significant cell growth inhibition activity (IC50 = 0.89 ± 0.06 μg/ml), even higher than the standard anticancer drugs; cisplatin (IC50 = 5.71 ± 0.55 μg/ml); and vinblastine sulfate (IC50 = 5.44 ± 0.64 μg/ml), while DQPC itself has the lowest cytotoxicity (IC50 = 9.9 ± 1.4 μg/ml). DNA binding study showed that DQPC and [Cu (DQPC)2]ClO4 strongly bind to DNA, presumably via intercalation and electrostatic mechanisms.
Prediction of curing kinetics of resorcinol‐added resole phenolic resins using differential scanning calorimetry for the fabrication of carbon/carbon composites
Authors: Cordeiro Jose C. , Davis Rachel E. , Ramsurn Hema , Crunkleton Daniel W. , Otanicar Todd P. , Keller Michael W. 
Published: August 2022

AbstractPhenolic resins are commonly used as carbon precursors for the fabrication of carbon/carbon composites due to their high carbon yield and aromatic nature. To decrease curing times, acid catalysts are generally used, but the addition of resorcinol was found to have a similar effect while being incorporated into the resin matrix with no contamination or corrosion issues. In this work, the curing kinetics of pure, 10, 20, and 30 wt% resorcinol‐added phenolic resins were investigated through differential scanning calorimetry. Heating rates of 0.5, 1, 2.5, and 5°C min−1 were used with several curing models to predict isothermal curing. Averaged mean absolute error (MAE) for the isoconversional mathematical approaches namely Kissinger–Akahira–Sunose (MAE = 12.9 min), Flynn–Wall–Ozawa (15.8 min), and Vyazovkin (14 min) show that these methods provide the best predictions, attributed to their adoption of an activation energy that depends on the extent of cure (Ea (α)). The Kissinger method (MAE = 36 min), which depends only on peak temperature with a constant activation energy assumption, and the data noise sensitive Friedman model (MAE = 1144.7 min) provide the least accurate results. Thermogravimetric analysis revealed that resorcinol decreases the curing times by up to 71% without lowering carbon yield.
Long‐term photo‐identification study of fin whales in the Pelagos Sanctuary (NW Mediterranean) as a baseline for targeted conservation and mitigation measures
Authors: Zanardelli Margherita , Airoldi Sabina , Bérubé Martine , Borsani J. Fabrizio , Di‐Meglio Nathalie , Gannier Alexandre , Hammond Philip S. , Jahoda Maddalena , Lauriano Giancarlo , Notarbartolo di Sciara Giuseppe , Panigada Simone 
Published: August 2022

Abstract

Historical abundance estimates are important for establishing baselines from which trends can be determined using more recent data. Long‐term studies based on photo‐identification were merged and used to estimate population size, survival rate and sex ratio (biopsy sampling) of fin whales in the North‐western Mediterranean.
Merging four existing photo‐id catalogues yielded a Mediterranean catalogue with 507 individually identified fin whales. Ninety‐five (18.7%) individuals were resighted at least once during the study period (1990–2007): 71 whales were resighted in different years, 24 within the same season and 13 both in the same season and in different years. The number of resightings within‐season ranged from one to four, over periods from 1 to 90 days.
Capture histories from these individuals were used in the capture–recapture analyses. Estimates of the animals present in the area each year between 1991 and 1995 through different modelling approaches were consistent: 900–1,000 from a POPAN open population model; 1,200 from a multi‐sample closed population model; and 900–1,100 from simple two‐sample closed population models for pairs of consecutive years, all with heavily overlapping 95% confidence intervals.
The estimated apparent survival rate of 0.916 (95% CI = 0.773–0.972) was lower than expected, which may be linked to temporary or permanent emigration, or mortality possibly owing to ship strikes.
Conservation and mitigation measures such as Important Marine Mammal Areas and Particularly Sensitive Sea Areas are presented and discussed.
Genome‐wide survey of open chromatin regions in two swallowtail butterflies Papilio machaon and P. bianor
Authors: Wan Wen‐ting , Hu Ping , Chang Zhou , Ren Yan‐dong , Dong Zhi‐wei , Yang Jie , Pan Xiang‐yu , He Jin‐wu , Liu Wei , Liu Gui‐chun , Zhao Ruo‐ping , Mao Chu‐yang , Li Jun , Wang Wen , Li Xue‐yan 
Published: August 2022

AbstractPapilio machaon was assigned as the type species for all butterflies by Linnaeus and P. bianor is a congener but exhibits a great difference in morphology (especially larva and adult color pattern) and larval host plants from P. machaon. Thus, they are the ideal models to investigate genetic mechanisms underlying morphology and plasticity between congeners. The reference genomes of both species were dissected in our previous studies, but little is known about their regulatory genome and the epigenetic regulation of gene expression throughout developmental stages. Here, we profiled the chromatin accessibility and gene expression of three developmental stages (the 4th instar larva [L4], the 5th instar larva [L5], and pupa [P]) using transposase accessible chromatin sequencing (ATAC‐seq) and RNA‐seq. Results showed that many accessible chromatin peaks were identified at three developmental stages (peak number, P. machaon: 44,977 [L4], 36,919 [L5], 47,147 [P]; P. bianor: 20,341 [L4], 44,668 [L5], 62,249 [P]). Moreover, the number of differentially accessible peaks and differentially expressed genes between larval stages of each butterfly species are significantly fewer than that between larval and pupal stages, suggesting a higher similarity within larvae and a significant difference between larvae and pupae. This study added the annotated information of chromatin accessibility genome‐wide of the two papilionid species and will promote the investigation of gene regulation in butterfly evolution.
Syk Activation in Circulating and Tissue Innate Immune Cells in Antineutrophil Cytoplasmic Antibody–Associated Vasculitis
Authors: Prendecki Maria , Gulati Kavita , Pisacano Noelle , Pinheiro Damilola , Bhatt Tejal , Mawhin Marie‐Anne , Toulza Frederic , Masuda Esteban S. , Cowburn Andrew , Lodge Katharine M. , Tam Frederick W. K. , Roufosse Candice , Pusey Charles D. , McAdoo Stephen P. 
Published: August 2022

ObjectiveSyk is a cytoplasmic protein tyrosine kinase that plays a role in signaling via B cell and Fc receptors (FcR). FcR engagement and signaling via Syk is thought to be important in antineutrophil cytoplasm antibody (ANCA) IgG–mediated neutrophil activation. This study was undertaken to investigate the role of Syk in ANCA‐induced myeloid cell activation and vasculitis pathogenesis.MethodsPhosphorylation of Syk in myeloid cells from healthy controls and ANCA‐associated vasculitis (AAV) patients was analyzed using flow cytometry. The effect of Syk inhibition on myeloperoxidase (MPO)–ANCA IgG activation of cells was investigated using functional assays (interleukin‐8 and reactive oxygen species production) and targeted gene analysis with NanoString. Total and phosphorylated Syk at sites of tissue inflammation in patients with AAV was assessed using immunohistochemistry and RNAscope in situ hybridization.ResultsWe identified increased phosphorylated Syk at critical activatory tyrosine residues in blood neutrophils and monocytes from patients with active AAV compared to patients with disease in remission or healthy controls. Syk was phosphorylated in vitro following MPO‐ANCA IgG stimulation, and Syk inhibition was able to prevent ANCA‐mediated cellular responses. Using targeted gene expression analysis, we identified up‐regulation of FcR‐ and Syk‐dependent signaling pathways following MPO‐ANCA IgG stimulation. Finally, we showed that Syk is expressed and phosphorylated in tissue leukocytes at sites of organ inflammation in AAV.ConclusionThese findings indicate that Syk plays a critical role in MPO‐ANCA IgG–induced myeloid cell responses and that Syk is activated in circulating immune cells and tissue immune cells in AAV; therefore, Syk inhibition may be a potential therapeutic option.
Recent Advances in Microfluidic Devices for the Radiosynthesis of PET‐imaging Probes
Authors: Elkawad Husamelden , Xu Yangyang , Tian Mei , Jin Chenyang , Zhang Hong , Yu Kaiwu , He Qinggang 
Published: August 2022

AbstractIn order to accommodate the growing demand for positron emission tomography (PET), it will be necessary to create innovative radiochemical and engineering technologies to optimize the manufacture and development of PET probes. Microfluidic devices allow radiosynthesis to be performed in microscale amounts, significantly impacting PET tracer production. Compared to traditional methods, microfluidic devices can produce PET tracers in a shorter time, higher yields, with lower reagent consumption, higher molar activity, and faster purification. This review examines microfluidic devices from an engineering perspective. Recently developed microfluidic radiosynthesis devices are classified into three categories according to their reaction volume: continuous‐flow, batch‐flow, and droplet‐based microreactors. The principles of device architecture, radiosynthesis process, and the relative strengths and limitations of each category are emphasized by citing typical examples. Finally, the possible future applications of this technology are outlined. A flexible, miniature, fully automated radiochemical microfluidic platform will offer more straightforward and cheaper molecular imaging procedures and the potential for precision medicine that could allow operators to create customized tracers for individual patient doses.
Modified Bacterial Cellulose for Biomedical Applications
Authors: Tang Karen Yuanting , Heng Jerry Zhi Xiong , Chai Casandra Hui Teng , Chan Chui Yu , Low Beverly Qian Ling , Chong Serene Ming En , Loh Hong Yi , Li Zibiao , Ye Enyi , Loh Xian Jun 
Published: August 2022

AbstractBacterial cellulose, or microbial cellulose, had gained tremendous interest as a hydrogel material for biomedical purposes in the recent years. It has many intrinsic physiological properties like fibrous nature, ultrafine 3D nanostructure network, high water holding capacity, excellent mechanical properties, biocompatibility and biodegradability that allow for the use of such purposes, and the lacking properties can be easily supplemented or enhanced by modifications. In this review, some of the biomedical applications that uses bacterial cellulose are discussed. These include wound healing, drug delivery, tissue engineering and tumor cell and cancer therapy. In each section, different modifications of BC are showcased and examined on how they benefit the application. Finally, key takeaways on these modifications are also deliberated.
Microsphere‐containing Hydrogel Scaffolds for Tissue Engineering
Authors: Zhang Shihao , Lin Anqi , Tao Ziwei , Fu Yingying , Xiao Lan , Ruan Guomo , Li Yulin 
Published: August 2022

AbstractKey Laboratory for Ultrafine Materials of Ministry of Education Centre for Biomedical Technologies Current tissue engineering technology aims to achieve the regeneration of human tissues, which integrates the key factors such as scaffolds, cells and biomolecules. Among these key factors, the development of high‐performance scaffolds is the basis for the success of tissue engineering strategies. In the past decades, hydrogel scaffolds have been developed rapidly and widely used in biomedical field, however, their drawbacks have also been revealed, which shows that a single hydrogel scaffold cannot meet the excellent performance required in the field of tissue engineering. Recently, microspheres have been further engineered to fabricate structurally and functionally reliable artificial three‐dimensional scaffolds of desired shape with enhanced specific biological functions. Therefore, the effective combination of hydrogel and microspheres can facilitate the development of high‐performance scaffolds for tissue engineering and further fine‐tuning the composite structure, which is expected to solve the dilemma faced by a single scaffold. In this review paper, we systematically summurized the type and preparation method for synthesis of hydrogel and microsphere materials commonly used in developing microsphere‐containing hydrogel scaffolds. We then reviewed the broad application of these hybrid scaffolds in various fields of tissue engineering, followed by a summary and perspective on future directions.
Reductive SN2’ Reaction of Epoxydienoate with Borane and its Application to the Synthesis and Structural Revision of an Antitumor Active Torrubiellutin Analogue
Authors: Murokawa Shunsuke , Furukawa Koki , Kawano Yoshinori , Nihei Tsukasa , Suzuki Yuji , Yasui Eiko , Nagumo Shinji 
Published: August 2022

AbstractA reductive SN2’ reaction of epoxydienoates and epoxyenoates with borane was developed to afford skipped dienoates and unconjugated enoates with trisubstituted Z‐alkene linked to asymmetric centers on one side or both sides. This reaction was successfully applied to the alternative synthesis of an antitumor active artificial analogue of torrubiellutin C. A geometric isomer for α,β‐unsaturated amide of the artificial analogue was also synthesized. These syntheses clarified the true structure of the antitumor active artificial analogue of torrubiellutin C.
Supramolecular Gels from Bis‐amides of L‐Phenylalanine: Synthesis, Structure and Material Applications
Authors: Manna Utsab , Roy Rajdip , Datta Hemanta Kumar , Dastidar Parthasarathi 
Published: August 2022

AbstractA series of small organic molecules having a bis‐amide backbone containing hydrogen‐bond functionalities were rationally designed, synthesized and characterized to examine their ability to act as potential low‐molecular‐weight gelators (LMWGs). All the bis‐amides were decorated with identical 3‐pyridyl amide of L‐phenylalanine moieties along with variously substituted terminal benzoyl groups. Gelation studies revealed that only 4‐methylphenyl substituted bis‐amide (PME) was capable of gelling both aqueous (DMSO/water) and methyl salicylate (MS) (an important solvent for topical formulation for medical applications) solvents; whereas 4‐chlorophenyl and 4‐bromophenyl substituted bis‐amides (PCL, PBR, respectively) acted as organogelator for various organic solvents. On the contrary, 4‐nitrophenyl as well as 3,5‐dinitrophenyl substituted bis‐amides (PNI, DNI, respectively) were unable to gel any solvents studied herein. The corresponding aqueous gel namely PME‐HG and three methyl salicylate gels PME‐MS, PCL‐MS and PBR‐MS were characterized by dynamic and table top rheology followed by electron microscopy. Single crystal X‐ray diffraction (SXRD) data revealed crucial insights into the supramolecular assembly of all the gelator and nongelator bis‐amides. Both PME‐HG and PME‐MS were rheoreversible – an important property in material applications. Interestingly, PME‐MS displayed remarkable material properties such as shape‐sustaining, loadbearing and self‐healing. Selected MS and aqueous gels loaded with nano‐molar iodine were found to possess anti‐bacterial property as revealed by zone inhibition assay.
Structure analysis of lipid A species in Vibrio parahaemolyticus by constructing mutants lacking multiple secondary acyltransferases of lipid A
Authors: Ji Fan , Huang Danyang , Tan Xin , Guo Yong , Wang Zhen , Zhou Qing , Wang Xiaoyuan 
Published: August 2022

AbstractFour secondary acyltransferases of Vibrio parahaemolyticus lipid A encoded by VP_RS00880, VP_RS08405, VP_RS12170, and VP_RS01045 have been identified. In this study, mutants of V. parahaemolyticus were constructed by deleting two, three, or four of these genes. The double mutants showed similar growth pattern with the wild‐type, but the quadruple mutant VPW011 showed significant growth defect at both 37°C and 21°C. Lipid A samples were extracted from these mutants and analyzed by electrospray ionization‐mass spectrometry. The double and triple mutants could synthesize hepta‐ and octa‐acylated lipid A species, while the quadruple mutant VPW011 could synthesize hexa‐ and hepta‐acylated lipid A. The results suggest that the four secondary acyltransferases could complement each other in V. parahaemolyticus. More importantly, additional secondary acyltransferases of lipid A might exist in V. parahaemolyticus and their activities might be as strong as the four known secondary acyltransferases. The unusual multiple secondary acyltransferases of lipid A might play roles in pathogenicity and antimicrobic resistance of V. parahaemolyticus.
GT‐biplot analysis of some biochemical characteristics and mineral composition of different sorghum (Sorghum bicolor L.) sprouts
Authors: Karaman Kevser , Kardeş Yusuf Murat , Doran Turhan , Akçura Mevlüt , Kaplan Mahmut 
Published: August 2022

AbstractBackground and ObjectivesThe nutritional value of the sprouts has gained interest in recent years because of supplying to fiber, vitamins, minerals, and bioactive compounds such as antioxidants into the diet. The aim of the present study was to reveal the nutritional characteristics of the different sorghum genotypes exposed to sprouting process. For this purpose, some biochemical characteristics and basic mineral profiles of the sorghum sprouts were investigated.FindingsAccording to the results, protein content ranged between 12.17% and 32.24% while the lowest total starch content was determined as to be 3.37% and the highest was 32.71%. Besides, dietary fiber content was in the range of 30.27%–46.42%. Total phenolic content and antiradical activity values of the sprouts were determined as in the range of 3.61–8.42 mg GAE/g and 11.63%–19.51%, respectively.ConclusionThe results showed that the sprouting process improved the nutritional quality of sorghum compared to grains and also significant variation was observed among the genotypes in terms of examined properties.Significance and NoveltyThe results showed that the nutritional parameters especially phytic acid levels of the sorghum grains could be decreased by sprouting process.
In situ Grignard Metalation Method, Part II: Scope of the One‐Pot Synthesis of Organocalcium Compounds
Authors: Schüler Philipp , Sengupta Simon , Koch Alexander , Görls Helmar , Krieck Sven , Westerhausen Matthias 
Published: August 2022

AbstractThe in situ Grignard Metalation Method (iGMM) is a straightforward one‐pot strategy to synthesize alkaline‐earth metal amides in multi‐gram scale with high yields via addition of bromoethane to an ethereal suspension of a primary or secondary amine and magnesium (Part I) or calcium (Part II). This method is highly advantageous because no activation of calcium is required prior to the reaction. Contrary to the magnesium‐based iGMM, there are some limitations, the most conspicuous one is the large influence of steric factors. The preparation of Ca(hmds)2 succeeds smoothly within a few hours with excellent yields opening the opportunity to prepare large amounts of this reagent. Side reactions and transfer of the iGMM to substituted anilines and N‐heterocycles as well as other H‐acidic substrates such as cyclopentadienes are studied. Bulky amidines cannot be converted directly to calcium amidinates via the iGMM but stoichiometric calciation with Ca(hmds)2 enables their preparation.