bluuebunny/crossref_metadata_2025 huggingface dataset:
Reliable Multi-View Deep Patent Classification
Authors: Zhang Liyuan , Liu Wei , Chen Yufei , Yue Xiaodong
Published: December 2022

Patent classification has long been regarded as a crucial task in patent information management and patent knowledge mining. In recent years, studies combining deep learning automatic patent classification methods with deep neural networks have significantly increased. Although great efforts have been made in the patent deep classification task, they mainly focus on information extraction from a single view (e.g., title or abstract view), but few studies concern multi-view deep patent classification, which aims to improve patent classification performance by integrating information from different views. To that end, we propose a reliable multi-view deep patent classification method. Within this method, we fuse multi-view patent information at the evidence level from the perspective of evidence theory, which not only effectively improves classification performance but also provides a reliable uncertainty estimation to solve the unreliability of classification results caused by property differences and inconsistencies in the different patent information sources. In addition, we theoretically prove that our approach can reduce the uncertainty of classification results through the fusion of multiple patent views, thus facilitating the performance and reliability of the classification results. The experimental results on 759,809 real-world multi-view patent data in Shanghai, China, demonstrate the effectiveness, reliability, and robustness of our approach.
A Two-Step Method of Estimation for Non-Linear Mixed-Effects Models
Authors: Wang Jianling , Luan Yihui , Jiang Jiming
Published: December 2022

The main goal of this paper is to propose a two-step method for the estimation of parameters in non-linear mixed-effects models. A first-step estimate θ˜ of the vector θ of parameters is obtained by solving estimation equations, with a working covariance matrix as the identity matrix. It is shown that θ˜ is consistent. If, furthermore, we have an estimated covariance matrix, V^, by θ˜, a second-step estimator θ^ can be obtained by solving the optimal estimation equations. It is shown that θ^ maintains asymptotic optimality. We establish the consistency and asymptotic normality of the proposed estimators. Simulation results show the improvement of θ^ over θ˜. Furthermore, we provide a method to estimate the variance σ2 using the method of moments; we also assess the empirical performance. Finally, three real-data examples are considered.
Drug Side Effect Prediction with Deep Learning Molecular Embedding in a Graph-of-Graphs Domain
Authors: Pancino Niccolò , Perron Yohann , Bongini Pietro , Scarselli Franco
Published: December 2022

Drug side effects (DSEs), or adverse drug reactions (ADRs), constitute an important health risk, given the approximately 197,000 annual DSE deaths in Europe alone. Therefore, during the drug development process, DSE detection is of utmost importance, and the occurrence of ADRs prevents many candidate molecules from going through clinical trials. Thus, early prediction of DSEs has the potential to massively reduce drug development times and costs. In this work, data are represented in a non-euclidean manner, in the form of a graph-of-graphs domain. In such a domain, structures of molecule are represented by molecular graphs, each of which becomes a node in the higher-level graph. In the latter, nodes stand for drugs and genes, and arcs represent their relationships. This relational nature represents an important novelty for the DSE prediction task, and it is directly used during the prediction. For this purpose, the MolecularGNN model is proposed. This new classifier is based on graph neural networks, a connectionist model capable of processing data in the form of graphs. The approach represents an improvement over a previous method, called DruGNN, as it is also capable of extracting information from the graph-based molecular structures, producing a task-based neural fingerprint (NF) of the molecule which is adapted to the specific task. The architecture has been compared with other GNN models in terms of performance, showing that the proposed approach is very promising.
The Ontology of Work during Pandemic Lockdown: A Semantic Network Analytical Approach
Authors: Cheng Kevin H C
Published: December 2022

Digital nomadism is emerging as a growing segment of the labor force. It is an insightful framework for understanding work during the pandemic and perhaps into the post-pandemic era because it construes work to be related to the notion of space, time and the instrumentality of work. The present study is about how people understand, relate, and make sense of their work during the early phase of the pandemic lockdown in 2020. The study will report difficulties that arise from work digitalization during the lockdown, and the study conceived the various dimensionality of work to cope with work challenges. Semantic network analysis (SNA) was used to aid the analysis of the contents from four European countries. One hundred and sixty respondents are interviewed using a semi-structured questionnaire. The words and word pairs from the SNA resulted in keywords identified for the four countries. There are common word hubs between the countries, such as hubs revolving around the meaning of ‘time’ and ‘meeting’. However, there are also unique hubs such as ‘task’, ‘office’ and “colleagues”. The results provide a cross-cultural comparison of how people adopted to work change. The organization of the word pairs in the network provided the narratives.
Effects of Yttrium on High Temperature Oxidation Resistance of W-Si-Y Self-Passivating Alloys
Authors: Ye Chao , Chen Shijie , Liu Wei , Xue Lihong , Yin Shengming , Yan Youwei
Published: December 2022

Self-passivating W alloys have excellent high temperature oxidation resistance and are expected to be used as a key component in high temperature environment. In this study, a series of W-Si-xY self-passivating alloys were fabricated by mechanical alloying (MA) and spark plasma sintering (SPS). Effects of Y content on phase compositions, microstructures, and oxidation resistance at high temperatures were investigated systematically. The results show that the oxidation resistance of the alloys increases with the increase of Y content (0.0~5.0 wt.%), but the oxidation resistance of the alloys deteriorates when the Y content reaches 9.6 wt.%. The alloy with 3.8 wt.% Y shows the best oxidation resistance. The thickness of its oxide layer is ~249.1 μm when the oxidation time reaches 80 h, which is thinner than that of other alloys. Effects of Y content on the oxidation resistance are revealed. During the oxidation process, Y can react with other elements to form molten-like W-Y-O and Y2Si2O7 particles. It is found that these two phases play a key role in the oxidation resistance of the alloys. When the Y content is in the range of 0~5.0 wt.%, a W-Y-O covering layer gradually forms with the increase of Y content, which can prevent further oxidation of the alloy. In the meantime, small Y2Si2O7 particles were formed and the microcracks formed around these particles were isolated, which have little effect on the oxidation resistance of the alloys. However, when Y content reaches 9.6 wt.%, large Y2Si2O7 particles and extensive cracks around them are formed. These cracks are interconnected to form penetrating channels for O2 from the environment to the alloy interior, which deteriorates the oxidation resistance of the alloys.
Microwave Absorbing Properties and Mechanism Analysis of Ni–Doped Fe–Based Metallic Microwires
Authors: Liu Jingshun , Wang Yamei , Qu Guanda , Liu Rui , Zhang Yun , Wang Congliang
Published: December 2022

Fe–based metallic microwires possess unique microstructure and size effects, exhibiting favorable mechanical, electrical, and magnetic properties, thus distinguishing them as a possible agents for use as microwave absorbing materials. In this paper, the absorbing properties of Ni–doped Fe–based metallic microwires optimized by orthogonal experiments were investigated, and based on the optimal parameters, the influencing mechanism of the Ni doping amount on the absorbing properties was further analyzed. It was noted that at the frequency f = 8.36 GHz, the maximum reflection loss RL and electromagnetic wave absorption efficiency Aeff can reach −54.89 dB and 99.999%, respectively. Moreover, the Ni doping amount could result in the improved wave-absorbing properties of composites, obtain the corresponding optimal parameters, and even change the position of the maximum absorption peak, which are all of great significance for practical engineering applications.
Electrochemical Fabrication of Inverse Opals of Silver with Cyanide-Free Electrolytes
Authors: Arabov Rustam I. , Komarova Maria Y. , Astafurov Mikhail O. , Knotko Alexander V. , Maslakov Konstantin I. , Savilov Serguei V. , Grigorieva Anastasia V.
Published: December 2022

Silver inverse opals were prepared electrochemically using non-toxic water–ethanol rhodanic and sulfite electrolytes for silver plating. Electrochemical crystallization of silver occurred in the pores of opal matrices made of 350 nm polystyrene microspheres. Samples with the most uniform structure and lowest percentage of surface admixtures were obtained from rhodanic electrolytes. Reflectance optical spectra of the silver inverse opals with a high surface periodicity showed various plasmon excitation modes in a visible spectral range making the silver opals attractive for plasmonics.
Association of Different ABO and Rh Blood Groups with the Erythroprotective Effect of Extracts from Navicula incerta and Their Anti-Inflammatory and Antiproliferative Properties
Authors: Ruiz-Cruz Saúl , González-Vega Ricardo Iván , Robles-Zepeda Ramón Enrique , Reyes-Díaz Aline , López-Elías José Antonio , Álvarez-Ainza Maritza Lizeth , Cinco-Moroyoqui Francisco Javier , Moreno-Corral Ramón Alfonso , Wong-Corral Francisco Javier , Borboa-Flores Jesús , Cornejo-Ramírez Yaeel Isbeth , Del-Toro-Sánchez Carmen Lizette
Published: December 2022

Previous studies have reported that different blood groups are associated with the risk of chronic degenerative diseases that mainly involve inflammation and neoplastic processes. We investigate the relationship between blood groups and the erythroprotective effect of extracts from Navicula incerta against oxidative damage as a proposal to develop drugs designed for people with a specific blood type related to chronic pathology. The study was carried out through the elucidation of the erythroprotective potential, anti-inflammatory and antiproliferative activity of Navicula incerta. Research suggests that the presence or absence of certain blood groups increases or decreases the abilities of certain phytochemicals to inhibit oxidative stress, which is related to the systemic inflammatory response involved in the development of different types of cancer. The pigment-rich extracts from Navicula incerta inhibit ROO•- induced oxidative stress in human erythrocytes on the A RhD+ve antigen without compromising the structure of the cell membrane. This result is very important, since the A antigen is related to the susceptibility of contracting prostate cancer. Similarly, it was possible to inhibit the proliferation of cervical (HeLa) and prostate (PC-3) carcinoma. The combinatorial analysis of different biological activities can help design phytochemicals as new candidates for preventive drugs treating the chronic degenerative diseases associated with a specific blood group.
Heat Waves Amplify the Urban Canopy Heat Island in Brno, Czechia
Authors: Janků Zdeněk , Dobrovolný Petr
Published: December 2022

This study used homogenised mean, maximum, and minimum daily temperatures from 12 stations located in Brno, Czechia, during the 2011–2020 period to analyse heat waves (HW) and their impact on the canopy urban heat island (UHI). HWs were recognized as at least three consecutive days with Tx ≥ 30 °C and urban–rural and intra-urban differences in their measures were analysed. To express the HWs contribution to UHI, we calculated the UHI intensities (UHII) separately during and outside of HWs to determine the heat magnitude (HM). Our results show that all HW measures are significantly higher in urban areas. UHII is mostly positive, on average 0.65 °C; however, day-time UHII is clearly greater (1.93 °C). Furthermore, day-time UHII is amplified during HWs, since HM is on average almost 0.5 °C and in LCZ 2 it is even 0.9 °C. Land use parameters correlate well with UHII and HM at night, but not during the day, indicating that other factors can affect the air temperature extremity. Considering a long-term context, the air temperature extremity has been significantly increasing recently in the region, together with a higher frequency of circulation types that favour the occurrence of HWs, and the last decade mainly contributed to this increase.
A Customizable and Low-Cost Ultraviolet Exposure System for Photolithography
Authors: Reynolds David Eun , Lewallen Olivia , Galanis George , Ko Jina
Published: December 2022

For microfluidic device fabrication in the research, industry, and commercial areas, the curing and transfer of patterns on photoresist relies on ultraviolet (UV) light. Often, this step is performed by commercial mask aligner or UV lamp exposure systems; however, these machines are often expensive, large, and inaccessible. To find an alternative solution, we present an inexpensive, customizable, and lightweight UV exposure system that is user-friendly and readily available for a homemade cleanroom. We fabricated a portable UV exposure system that costs under $200. The wafer holder’s adjustable height enabled for the selection of the appropriate curing distance, demonstrating our system’s ability to be easily tailored for different applications. The high light uniformity across a 4” diameter wafer holder (light intensity error ~2.9%) was achieved by adding a light diffusing film to the apparatus. These values are comparable to the light uniformity across a 5” diameter wafer holder from a commercial mask aligner (ABM 3000HR Mask Aligner), that has a light intensity error of ~4.0%. We demonstrated the ability to perform photolithography with high quality by fabricating microfluidic devices and generating uniform microdroplets. We achieved comparable quality to the wafer patterns, microfluidic devices, and droplets made from the ABM 3000HR Mask Aligner.
Multi-Locus Sequencing Reveals Putative Novel Anaplasmataceae Agents, ‘Candidatus Ehrlichia dumleri’ and Anaplasma sp., in Ring-Tailed Coatis (Carnivora: Nasua nasua) from Urban Forested Fragments at Midwestern Brazil
Authors: Perles Lívia , Herrera Heitor M. , Barreto Wanessa T. G. , de Macedo Gabriel C. , Calchi Ana C. , Machado Rosangela Z. , André Marcos R.
Published: December 2022

The Anaplasmataceae family encompasses obligate intracellular α-proteobacteria of human and veterinary medicine importance. This study performed multi-locus sequencing to characterize Ehrlichia and Anaplasma in coati’s blood samples in Midwestern Brazil. Twenty-five samples (25/165—15.1%) were positive in the screening PCR based on the dsb gene of Ehrlichia spp. and were characterized using 16S rRNA, sodB, groEL, and gltA genes and the 23S-5S intergenic space region (ITS). Phylogenetic analyses based on all six molecular markers positioned the sequences into a new clade, with a common origin of Ehrlichia ruminantium. Haplotype analyses of 16S RNA sequences revealed the presence of two distinct Ehrlichia genotypes. Six samples (6/165, 3.6%) were positive in the screening nPCR for the 16S rRNA gene of Anaplasma spp. and were submitted to an additional PCR targeting the ITS for molecular characterization. Phylogenetic analyses based on both 16S rRNA gene and ITS positioned the Anaplasma sp. detected in the present study in a large clade with other Anaplasma sp. previously detected in ticks and wild animals and in a clade with ‘Candidatus Anaplasma brasiliensis’, respectively. Based on distinct molecular markers, the present work described a putative novel Anaplasmataceae agent, namely ‘Candidatus Ehrlichia dumleri’, and Anaplasma sp. closely related to the previously described ‘Candidatus Anaplasma brasiliensis’.
Molecular Characterization of Octopamine/Tyramine Receptor Gene of Amitraz-Resistant Rhipicephalus (Boophilus) decoloratus Ticks from Uganda
Authors: Vudriko Patrick , Umemiya-Shirafuji Rika , Tayebwa Dickson Stuart , Byaruhanga Joseph , Byamukama Benedicto , Tumwebaze Maria , Xuan Xuenan , Suzuki Hiroshi
Published: December 2022

We previously reported the emergence of amitraz-resistant Rhipicephalus (Boophilus) decoloratus ticks in the western region of Uganda. This study characterized the octopamine/tyramine receptor gene (OCT/Tyr) of amitraz-resistant and -susceptible R. (B.) decoloratus ticks from four regions of Uganda. The OCT/Tyr gene was amplified from genomic DNA of 17 R. (B.) decoloratus larval populations of known susceptibility to amitraz. The amplicons were purified, cloned and sequenced to determine mutations in the partial coding region of the OCT/Tyr gene. The amplified R. (B.) decoloratus OCT/Tyr gene was 91–100% identical to the R. (B.) microplus OCT/Tyr gene. Up to 24 single nucleotide polymorphisms (SNPs) were found in the OCT/Tyr gene from ticks obtained from high acaricide pressure areas, compared to 8 from the low acaricide pressure areas. A total of eight amino acid mutations were recorded in the partial OCT/Tyr gene from ticks from the western region, and four of them were associated with amitraz-resistant tick populations. The amino acid mutations M1G, L16F, D41G and V72A were associated with phenotypic resistance to amitraz with no specific pattern. Phylogenetic analysis revealed that the OCT/Tyr gene sequence from this study clustered into two distinct groups that separated the genotype from high acaricide pressure areas from the susceptible populations. In conclusion, this study is the first to characterize the R. (B.) decoloratus OCT/Tyr receptor gene and reports four novel amino acid mutations associated with phenotypic amitraz resistance in Uganda. However, lack of mutations in the ORF of the OCT/Tyr gene fragment for some of the amitraz-resistant R. (B.) decoloratus ticks could suggest that other mechanisms of resistance may be responsible for amitraz resistance, hence the need for further investigation.
Exploiting Conserved Quorum Sensing Signals in Streptococcus mutans and Streptococcus pneumoniae
Authors: Bernabè Giulia , Pauletto Anthony , Zamuner Annj , Cassari Leonardo , Castagliuolo Ignazio , Brun Paola , Dettin Monica
Published: December 2022

Bacterial species of the Streptococcus genera are considered either commensal bacteria or potential pathogens, according to their metabolic evolution and production of quorum sensing (QS)-controlled virulence factors. S. mutans, in particular, has become one of the best-studied examples of bacteria that are able to get along or cheat commensal species, even of the same genera. S. mutans and S. pneumoniae share homolog QS pathways and a competence stimulating peptide (CSP) for regulating bacteriocin production. Intriguingly, the abundance of S. pneumoniae and S. mutans alternates in complex microbial communities, thus opening the role for the fratricide communication of homolog QS systems. Since the inhibition of the QS has been proposed in treating bacterial infections, in this study, we designed and synthesized analogs of S. pneumoniae CSP with precise residual modifications. We reported that S. pneumoniae CSP analogs reduced the expression of genes involved in the QS of S. mutans and biofilm formation without affecting bacterial growth. The CSP analogs inhibited bacteriocin production in S. mutans, as reported by co-cultures with commensal bacteria of the oral cavity. The peptide CSP1AA, bearing substitutions in the residues involved in QS receptor recognition and activation, reported the most significant quorum-quenching activities. Our findings provide new insights into specific chemical drivers in the CSP sequences controlling the interconnection between S. mutans and S. pneumoniae. We think that the results reported in this study open the way for new therapeutic interventions in controlling the virulence factors in complex microbial communities such as the oral microbiota.
Radioactive Isotopes as a Tool for Pairing Identification of the HAH 346—Hammadah al Hamra 346—Ordinary Chondrites from Two Separate Find Areas
Authors: Długosz-Lisiecka Magdalena , Jakubowski Tomasz , Krystek Marcin , ElMallul Ahmed
Published: December 2022

In this study, low-background gamma spectrometry was used to confirm the identity of a set of ordinary chondrites found in 2018 and 2019, by different expeditions, in a part of the Al-Hamada al-Hamra desert, in the region of Al-Dżabal al-Gharbi, in Libya. Ten specimens of ordinary chondrites from two different campaigns were investigated. An analysis was carried out using a unique gamma spectrometry system to obtain the optimal measurement conditions for the quantitative identification of the radioactive isotopes. Chondrite radiometric studies enabled a detailed analysis of the activities of radioactive isotopes—the short-lived 22Na, 54Mn, 60Co, and long-lived 26Al, 40K. For most isotopes, the activities are expected to be similar for ordinary chondrites with the same irradiation history. Short-lived radionuclide concentrations can be considered, as a specific fingerprint of the chondrite terrestrial age, to confirm whether meteorites originate from a single fall. The HaH 346 group of chondrites was classified in February 2021. The data sets have been analyzed based on multivariate chemometric techniques, including K-means, PCA, and clustering analysis, to derive essential information and confirm similarities or significant differences between the studied specimens.
Natural Products as Anticancer Agents: Current Status and Future Perspectives
Authors: Naeem Abid , Hu Pengyi , Yang Ming , Zhang Jing , Liu Yali , Zhu Weifeng , Zheng Qin
Published: December 2022

Natural products have been an invaluable and useful source of anticancer agents over the years. Several compounds have been synthesized from natural products by modifying their structures or by using naturally occurring compounds as building blocks in the synthesis of these compounds for various purposes in different fields, such as biology, medicine, and engineering. Multiple modern and costly treatments have been applied to combat cancer and limit its lethality, but the results are not significantly refreshing. Natural products, which are a significant source of new therapeutic drugs, are currently being investigated as potential cytotoxic agents and have shown a positive trend in preclinical research and have prompted numerous innovative strategies in order to combat cancer and expedite the clinical research. Natural products are becoming increasingly important for drug discovery due to their high molecular diversity and novel biofunctionality. Furthermore, natural products can provide superior efficacy and safety due to their unique molecular properties. The objective of the current review is to provide an overview of the emergence of natural products for the treatment and prevention of cancer, such as chemosensitizers, immunotherapeutics, combinatorial therapies with other anticancer drugs, novel formulations of natural products, and the molecular mechanisms underlying their anticancer properties.
A Simple High-Throughput Field Sample Preparation Method Based on Matrix-Induced Sugaring-Out for the Simultaneous Determination of 5-Hydroxymethylfurfural and Phenolic Compounds in Honey
Authors: Tu Xijuan , Yu Fengjie , Jin Qian , Du Chunping , Chen Jiaxu , Yang Ji , He Yuchang , Huang Shaokang , Chen Wenbin
Published: December 2022

In the present work, a high-throughput field sample preparation method was reported for the simultaneous determination of 5-hydroxymethylfurfural and phenolic compounds in honey. Combining a simple and green homogenous liquid–liquid extraction, matrix-induced sugaring-out, with the use of a 96-deepwell plate and multichannel pipette, the proposed method showed its merits in instrument-free and high-throughput preparation. Due to the high-throughput property, the parameters of the method were rapidly and systematically studied using a constructed 4 × 2 × 4 × 3 array (sample amount × ratio of ACN:H2O × standing time × replicates) in a 96-deepwell plate. Analytical performance was fully validated, and the limits of detection and limits of quantification were in the range of 0.17–1.35 μg/g and 0.51–4.14 μg/g, respectively. Recoveries were between 83.98 and 117.11%, and all the precisions were <5%. Furthermore, the developed method was successfully applied in the outdoor preparation of commercial honey samples and the in-field preparation of raw honey samples in apiary. The current work presented a simple, rapid, and high-throughput method for the field sample preparation of honey and provides a valuable strategy for the design of field and on-site sample preparation.
Molecular Cloning, Expression, and Functional Analysis of Glycosyltransferase (TbUGGT) Gene from Trapa bispinosa Roxb.
Authors: Ye Shijie , Yin Dongjie , Sun Xiaoyan , Chen Qinyi , Min Ting , Wang Hongxun , Wang Limei
Published: December 2022

Trapa bispinosa Roxb. is an economical crop for medicine and food. Its roots, stems, leaves, and pulp have medicinal applications, and its shell is rich in active ingredients and is considered to have a high medicinal value. One of the main functional components of the Trapa bispinosa Roxb. shell is 1-galloyl-beta-D-glucose (βG), which can be used in medical treatment and is also an essential substrate for synthesizing the anticancer drug beta-penta-o-Galloyl-glucosen (PGG). Furthermore, gallate 1-beta-glucosyltransferase (EC 2.4.1.136) has been found to catalyze gallic acid (GA) and uridine diphosphate glucose (UDPG) to synthesize βG. In our previous study, significant differences in βG content were observed in different tissues of Trapa bispinosa Roxb. In this study, Trapa bispinosa Roxb. was used to clone 1500 bp of the UGGT gene, which was named TbUGGT, to encode 499 amino acids. According to the specificity of the endogenous expression of foreign genes in Escherichia coli, the adaptation codon of the cloned original genes was optimized for improved expression. Bioinformatic and phylogenetic tree analyses revealed the high homology of TbUGGT with squalene synthases from other plants. The TbUGGT gene was constructed into a PET-28a expression vector and then transferred into Escherichia coli Transsetta (DE3) for expression. The recombinant protein had a molecular weight of 55 kDa and was detected using SDS-PAGE. The proteins were purified using multiple fermentation cultures to simulate the intracellular environment, and a substrate was added for in vitro reaction. After the enzymatic reaction, the levels of βG in the product were analyzed using HPLC and LC-MS, indicating the catalytic activity of TbUGGT. The cloning and functional analysis of TbUGGT may lay the foundation for further study on the complete synthesis of βG in E. coli.
Design, Synthesis, and Anti-Fungal Evaluation of Heterocyclic Benzoxazole Derivatives
Authors: Wang Ruibo , Kang Ruiting , Yang Xuan , Cheng Yu , Bai Hongjin , Du Zhenting
Published: December 2022

In order to discover more promising anti-fungal agents, a series of benzoxazole family was synthesized by PPA-catalyzed condensation and a Raney nickel/hydrazine reduction. Altogether 45 compounds were obtained in good to excellent yields and characterized by FT-IR, NMR, MS, and X-ray crystal diffraction. Moreover, the biological activity against eight phytopathogenic fungi was investigated. All in all, most of these compounds bear moderate antifungal activities. Among them, three candidates show the strongest activities, compound 4ac, 4bc provided over 50% inhibition rate against five fungi. Especially, the inhibitory rate of compound 4ah on Mycosphaerella melonis reached 76.4%.
Synthesis and the Crystal Structure of a New Chiral 1D Metal–Organic Coordination Polymer Based on L-Prolineamide-Substituted Diarylacetylenedicarboxylic Acid Derivative
Authors: Veselovsky Vladimir V. , Isaeva Vera I. , Nissenbaum Vera D. , Kustov Leonid M. , Chernyshev Vladimir V.
Published: December 2022

The new homochiral 1D metal–organic coordination polymer [Cu2(EDPB)•H2O]n was synthesized starting from the original 3,3′-ethyne-1,2-diylbis[6-(L-prolylamino)benzoic acid] (H4EDPB). The unique crystal structure of the new compound was established by powder X-ray diffraction. The [Cu2(EDPB)•H2O]n system shows catalytic activity and enantioselectivity in a Henry reaction of p-nitrobenzaldehyde with nitromethane.
New Constructed EEM Spectra Combined with N-PLS Analysis Approach as an Effective Way to Determine Multiple Target Compounds in Complex Samples
Authors: Li Zeying , Feng Na , Li Xinkang , Lin Yuan , Zhang Xiangzhi , Li Baoqiong
Published: December 2022

Excitation–emission matrix (EEM) fluorescence spectroscopy has been applied to many fields. In this study, a simple method was proposed to obtain the new constructed three-dimensional (3D) EEM spectra based on the original EEM spectra. Then, the application of the N-PLS method to the new constructed 3D EEM spectra was proposed to quantify target compounds in two complex data sets. The quantitative models were established on external sample sets and validated using statistical parameters. For validation purposes, the obtained results were compared with those obtained by applying the N-PLS method to the original EEM spectra and applying the PLS method to the extracted maximum spectra in the concatenated mode. The comparison of the results demonstrated that, given the advantages of less useless information and a high calculating speed of the new constructed 3D EEM spectra, N-PLS on the new constructed 3D EEM spectra obtained better quantitative analysis results with a correlation coefficient of prediction above 0.9906 and recovery values in the range of 85.6–95.6%. Therefore, one can conclude that the N-PLS method combined with the new constructed 3D EEM spectra is expected to be broadened as an alternative strategy for the simultaneous determination of multiple target compounds.
Modulation Effects of Fe3+, Zn2+, and Cu2+ Ions on the Amyloid Fibrillation of α-Synuclein: Insights from a FTIR Investigation
Authors: Li Yan , Yu Yang , Ma Gang
Published: December 2022

Amyloid fibrillation of α-synuclein is implicated in the pathogenesis of Parkinson’s disease and heavy metal ions such as Fe3+, Zn2+, and Cu2+ are known to be involved in the process. In this work, we explored the use of FTIR spectroscopy to look into the modulation effects of Fe3+, Zn2+, and Cu2+ on the amyloid fibrillation of α-synuclein. We performed a curve-fitting analysis on the FTIR amide I bands of these α-synuclein fibril systems, namely, the pristine fibril and the fibrils prepared in the presence of Fe3+, Zn2+, and Cu2+. We found that the α-synuclein fibrils under the influences of metal ions all possessed a parallel β-sheet structure, turn structure, and disordered structure, similar to that of pristine α-synuclein fibril. We also observed metal-induced increases in the proportions of the β-sheet secondary structure within the α-synuclein fibrils, with Fe3+ being the most effective inducer. We performed second derivative analysis of the side chain carboxylic groups of α-synuclein fibrils and found that the side chain microenvironment of the α-synuclein fibrils was more influenced by Fe3+ than Zn2+, and Cu2+. In addition, our atomic force microscopic study revealed that the morphologies of α-synuclein fibrils under the influence of Fe3+ was quite different from that of the Zn2+ and Cu2+ systems. Our FTIR results suggested that the modulation effects of Fe3+, Zn2+, and Cu2+ on α-synuclein fibrillation occurred at both secondary and quaternary structural levels. At last, we proposed a mechanistic hypothesis to interpret how metal ions could affect the morphology of α-synuclein amyloid fibril based on the conformational plasticity properties of intrinsically disordered proteins.
Fabrication of Chitosan-Based Network Polysaccharide Nanogels
Authors: Nakamichi Aina , Kadokawa Jun-ichi
Published: December 2022

In this study, we developed a method to fabricate chitosan-based network polysaccharides via the condensation between amino groups in water-soluble chitosan (WSCS) and a carboxylate-terminated maltooligosaccharide crosslinker. We previously reported on the fabrication of network-polysaccharide-based macroscopic hydrogels via the chemical crosslinking of water-soluble chitin (WSCh) with the crosslinker. Because the molecular weight of the WSCS was much smaller than that of the WSCh, in the present investigation, the chemical crosslinking of the WSCS with the crosslinker was observed at the nanoscale upon the condensation between amino and carboxylate groups in the presence of a condensing agent, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, and N-hydroxysuccinimide, affording nano-sized chitosan-based network polysaccharides. The occurrence of the crosslinking via the formation of amido linkages was supported by the IR analysis and 1H NMR measurements after the dissolution via acid hydrolysis in DCl/D2O. The products formed nanogels, whose sizes depended on the amino/carboxylate feed ratio. The nanoscale morphology and size of the products were evaluated via scanning electron microscopy, dynamic light scattering analyses, and transition electron microscopy. In the present study, we successfully developed the method to fabricate nanogel materials based on network polysaccharide structures, which can practically be applied as new polysaccharide-based 3D bionanomaterials.
Facile Synthesis of ZIF-67 for the Adsorption of Methyl Green from Wastewater: Integrating Molecular Models and Experimental Evidence to Comprehend the Removal Mechanism
Authors: Ikram Muniba , Mutahir Sadaf , Humayun Muhammad , Khan Muhammad Asim , Al-Humaidi Jehan Y. , Refat Moamen S. , Abouzied Amr S.
Published: December 2022

Organic dyes with enduring colors which are malodorous are a significant source of environmental deterioration due to their virulent effects on aquatic life and lethal carcinogenic effects on living organisms. In this study, the adsorption of methyl green (MG), a cationic dye, was achieved by using ZIF-67, which has been deemed an effective adsorbent for the removal of contaminants from wastewater. The characterization of ZIF-67 was done by FTIR, XRD, and SEM analysis. The adsorption mechanism and characteristics were investigated with the help of control batch experiments and theoretical studies. The systematical kinetic studies and isotherms were sanctioned with a pseudo-second-order model and a Langmuir model (R2 = 0.9951), confirming the chemisorption and monolayer interaction process, respectively. The maximum removal capacities of ZIF-67 for MG was 96% at pH = 11 and T = 25 °C. DFT calculations were done to predict the active sites in MG by molecular electrostatic potential (MEP). Furthermore, both Molecular dynamics and Monte Carlo simulations were also used to study the adsorption mechanism.
Visible Light Promotes Cascade Trifluoromethylation/Cyclization, Leading to Trifluoromethylated Polycyclic Quinazolinones, Benzimidazoles and Indoles
Authors: Ma Ransong , Ren Yuanyuan , Deng Zhoubin , Wang Ke-Hu , Wang Junjiao , Huang Danfeng , Hu Yulai , Lv Xiaobo
Published: December 2022

Efficient visible-light-induced radical cascade trifluoromethylation/cyclization of inactivated alkenes with CF3Br, which is a nonhygroscopic, noncorrosive, cheap and industrially abundant chemical, was developed in this work, producing trifluoromethyl polycyclic quinazolinones, benzimidazoles and indoles under mild reaction conditions. The method features wide functional group compatibility and a broad substrate scope, offering a facile strategy to pharmaceutically produce valuable CF3-containing polycyclic aza-heterocycles.
Synthesis and Characterization of Lanthanide Metal Ion Complexes of New Polydentate Hydrazone Schiff Base Ligand
Authors: Pospieszna-Markiewicz Izabela , Fik-Jaskółka Marta A. , Hnatejko Zbigniew , Patroniak Violetta , Kubicki Maciej
Published: December 2022

The new homodinuclear complexes of the general formula [Ln2L3(NO3)3] (where HL is newly synthesized 2-((2-(benzoxazol-2-yl)-2-methylhydrazono)methyl)phenol and Ln = Sm3+ (1), Eu3+ (2), Tb3+ (3a, 3b), Dy3+ (4), Ho3+ (5), Er3+ (6), Tm3+ (7), Yb3+ (8)), have been synthesized from the lanthanide(III) nitrates with the polydentate hydrazone Schiff base ligand. The flexibility of this unsymmetrical Schiff base ligand containing N2O binding moiety, attractive for lanthanide metal ions, allowed for a self-assembly of these complexes. The compounds were characterized by spectroscopic data (ESI-MS, IR, UV/Vis, luminescence) and by the X-ray structure determination of the single crystals, all of which appeared to be different solvents. The analytical data suggested 2:3 metal:ligand stoichiometry in these complexes, and this was further confirmed by the structural results. The metal cations are nine-coordinated, by nitrogen and oxygen donor atoms. The complexes are two-centered, with three oxygen atoms in bridging positions. There are two types of structures, differing by the sources of terminal (non-bridging) coordination centers (group A: two ligands, one nitro anion/one ligand, two nitro anions, group B: three ligands, three anions).
Exploratory Metabolomics Underscores the Folate Enzyme ALDH1L1 as a Regulator of Glycine and Methylation Reactions
Authors: Rushing Blake R. , Fogle Halle M. , Sharma Jaspreet , You Mikyoung , McCormac Jonathan P. , Molina Sabrina , Sumner Susan , Krupenko Natalia I. , Krupenko Sergey A.
Published: December 2022

Folate (vitamin B9) is involved in one-carbon transfer reactions and plays a significant role in nucleic acid synthesis and control of cellular proliferation, among other key cellular processes. It is now recognized that the role of folates in different stages of carcinogenesis is complex, and more research is needed to understand how folate reactions become dysregulated in cancers and the metabolic consequences that occur as a result. ALDH1L1 (cytosolic 10-formyltetrahydrofolate dehydrogenase), an enzyme of folate metabolism expressed in many tissues, is ubiquitously downregulated in cancers and is not expressed in cancer cell lines. The RT4 cell line (derived from papillary bladder cancer) which expresses high levels of ALDH1L1 represents an exception, providing an opportunity to explore the metabolic consequences of the loss of this enzyme. We have downregulated this protein in RT4 cells (shRNA driven knockdown or CRISPR driven knockout) and compared metabolomes of ALDH1L1-expressing and -deficient cells to determine if metabolic changes linked to the loss of this enzyme might provide proliferative and/or survival advantages for cancer cells. In this study, cell extracts were analyzed using Ultra High Performance Liquid Chromatography High Resolution Mass Spectrometry (UHPLC-HR-MS). A total of 13,339 signals were identified or annotated using an in-house library and public databases. Supervised and unsupervised multivariate analysis revealed metabolic differences between RT4 cells and ALDH1L1-deficient clones. Glycine (8-fold decrease) and metabolites derived from S-adenosylmethionine utilizing pathways were significantly decreased in the ALDH1L1-deficient clones, compared with RT4 cells. Other changes linked to ALDH1L1 downregulation include decreased levels of amino acids, Krebs cycle intermediates, and ribose-5-phosphate, and increased nicotinic acid. While the ALDH1L1-catalyzed reaction is directly linked to glycine biosynthesis and methyl group flux, its overall effect on cellular metabolism extends beyond immediate metabolic pathways controlled by this enzyme.
Gallic Acid-Loaded Sodium Alginate-Based (Polyvinyl Alcohol-Co-Acrylic Acid) Hydrogel Membranes for Cutaneous Wound Healing: Synthesis and Characterization
Authors: Naeem Abid , Yu Chengqun , Zhu Weifeng , Chen Xuanbin , Wu Xuan , Chen Lihua , Zang Zhenzhong , Guan Yongmei
Published: December 2022

Traditional wound dressings often cannot treat wounds caused by bacterial infections or other wound types that are insensitive to these wound treatments. Therefore, a biodegradable, bioactive hydrogel wound dressing could be an effective alternative option. The purpose of this study was to develop a hydrogel membrane comprised of sodium alginate, polyvinyl alcohol, acrylic acid, and gallic acid for treating skin wounds. The newly developed membranes were analyzed using Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM), X-ray diffraction analysis (XRD), sol-gel fraction, porosity, mechanical strength, swelling, drug release and data modelling, polymeric network parameters, biodegradation, and antioxidation (DPPH and ABTS) and antimicrobial activity against Gram-positive and negative bacteria. The results revealed that hydrogel membranes were crosslinked successfully and had excellent thermal stability, high drug loading, greater mechanical strength, and exhibited excellent biodegradation. Additionally, the swelling ability and the porosity of the surface facilitated a controlled release of the encapsulated drug (gallic acid), with 70.34% release observed at pH 1.2, 70.10% at pH 5.5 (normal skin pH), and 86.24% at pH 7.4 (wounds pH) in 48 h. The gallic acid-loaded hydrogel membranes showed a greater area of inhibition against Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli bacteria as well as demonstrated excellent antioxidant properties. Based on Franz cell analyses, the permeation flux of the drug from optimized formulations through mice skin was 92 (pH 5.5) and 110 (pH 7.4) μg/cm2·h−1. Moreover, hydrogel membranes retained significant amounts of drug in the skin for 24 h, such as 2371 (pH 5.5) and 3300 µg/cm2 (pH 7.4). Acute dermal irritation tests in rats showed that hydrogel membranes were nonirritating. Hydrogel membranes containing gallic acid could be an effective option for improving wound healing and could result in faster wound healing.
Influencing the Crystalline Domains of Poly(vinylidenedifluoride) Composites Using Fluorinated Silica Nanoparticles as Drop-In Modifiers
Authors: Weeks Nathan J. , Phelps Cole R. , Gazmin Enrique T. , Iacono Scott T.
Published: December 2022

Improvements to fluoropolymer processing techniques by way of utilizing nanoparticles as drop-in processing aids have pronounced effects on bulk composite properties. In this work, we prepared fluoroalkyl-silanized silica nanoparticles (F-SiNPs, ca. 200 nm) that were solvent-blended with polyvinylenedifluoride (PVDF) in order to prepare composites with varying weight fractions. We demonstrated that the ability to functionalize SiNPs with long fluoroalkylchains that induced co-crystallization with the PVDF matrix, resulting in uniform particle dispersion and improved interlaminate adhesion. This was quantitatively investigated using calorimetry and thermogravimetric analysis, which showed a decrease in the bulk crystallinity of the virgin PVDF from 37% to 10% with minimal 10 wt % F-SiNP loading, rendering a nearly amorphous PVDF. Additional discussions in this work include the effects of various bare and fluoroalkyl-functionalized SiNP loadings on the amorphous and crystalline domains of the PVDF matrix, as well as thermal decomposition.
Thermal Conductivity of Solid Triphenyl Phosphite
Authors: Krivchikov Alexander , Andersson Ove , Korolyuk Oksana , Kryvchikov Oleksii
Published: December 2022

The thermal conductivity, κ, of solid triphenyl phosphite was measured by using the transient hot-wire method, and its temperature and pressure dependencies were analyzed to understand heat transfer processes in the solid polymorphic phases, as well as in the glass and the exotic glacial state. Phase transformations and the structural order of the phases are discussed, and a transitional pressure–temperature diagram of triphenyl phosphite is presented. The thermal conductivity of both the crystalline and disordered states is described within the theory of two-channel heat transfer by phonons and diffusons in dielectric solids. In the glass and glacial states, the weakly temperature-dependent (glass-like) κ is described well by the term associated with heat conduction of diffusons only, and it can be represented by an Arrhenius-type function. In the crystal phases, the strongly temperature-dependent (crystal-like) κ associated with heat transfer by phonons is weakened by significant heat transfer by diffusons, and the extent of the two contributions is reflected in the temperature dependence of κ. We find that the contribution of diffusons in the crystal phases depends on pressure in the same way as that in amorphous states, thus indicating that the same mechanism is responsible for this channel of heat transfer in crystals and amorphous states.
Fabrication of PEGylated Chitosan Nanoparticles Containing Tenofovir Alafenamide: Synthesis and Characterization
Authors: Zaman Muhammad , Butt Muhammad Hammad , Siddique Waqar , Iqbal Muhammad Omer , Nisar Naveed , Mumtaz Asma , Nazeer Hafiza Yusra , Alshammari Abdulrahman , Riaz Muhammad Shahid
Published: December 2022

Tenofovir alafenamide (TAF) is an antiretroviral (ARV) drug that is used for the management and prevention of human immunodeficiency virus (HIV). The clinical availability of ARV delivery systems that provide long-lasting protection against HIV transmission is lacking. There is a dire need to formulate nanocarrier systems that can help in revolutionizing the way to fight against HIV/AIDS. Here, we aimed to synthesize a polymer using chitosan and polyethylene glycol (PEG) by the PEGylation of chitosan at the hydroxyl group. After successful modification and confirmation by FTIR, XRD, and SEM, TAF-loaded PEGylated chitosan nanoparticles were prepared and analyzed for their particle size, zeta potential, morphology, crystallinity, chemical interactions, entrapment efficacy, drug loading, in vitro drug release, and release kinetic modeling. The fabricated nanoparticles were found to be in a nanosized range (219.6 nm), with ~90% entrapment efficacy, ~14% drug loading, and a spherical uniform distribution. The FTIR analysis confirmed the successful synthesis of PEGylated chitosan and nanoparticles. The in vitro analysis showed ~60% of the drug was released from the PEGylated polymeric reservoir system within 48 h at pH 7.4. The drug release kinetics were depicted by the Korsmeyer–Peppas release model with thermodynamically nonspontaneous drug release. Conclusively, PEGylated chitosan has the potential to deliver TAF from a nanocarrier system, and in the future, cytotoxicity and in vivo studies can be performed to further authenticate the synthesized polymer.
Spectroscopic, Thermodynamic and Molecular Docking Studies on Molecular Mechanisms of Drug Binding to Proteins
Authors: Wani Tanveer A. , Zargar Seema , Hussain Afzal
Published: December 2022

Molecular recognition, which is the process of biological macromolecules interacting with each other or various small molecules with a high specificity and affinity to form a specific complex, constitutes the basis of all processes in living organisms [...]