bluuebunny/crossref_metadata_2025 huggingface dataset:
Regulation and Therapeutic Targeting of MTHFD2 and EZH2 in KRAS-Mutated Human Pulmonary Adenocarcinoma
Authors: Li Yuchan , Elakad Omar , Yao Sha , von Hammerstein-Equord Alexander , Hinterthaner Marc , Danner Bernhard C. , Ferrai Carmelo , Ströbel Philipp , Küffer Stefan , Bohnenberger Hanibal
Published: July 2022

Activating KRAS mutations occur in about 30% of pulmonary adenocarcinoma (AC) cases and the discovery of specific inhibitors of G12C-mutated KRAS has considerably improved the prognosis for a subgroup of about 14% of non-small cell lung cancer (NSCLC) patients. However, even in patients with a KRAS G12C mutation, the overall response rate only reaches about 40% and mutations other than G12C still cannot be targeted. Despite the fact that one-carbon metabolism (1CM) and epigenetic regulation are known to be dysregulated by aberrant KRAS activity, we still lack evidence that co-treatment with drugs that regulate these factors might ameliorate response rates and patient prognosis. In this study, we show a direct dependency of Methylenetetrahydrofolate dehydrogenase 2 (MTHFD2) and Enhancer of Zeste Homolog 2 (EZH2) expression on mutationally activated KRAS and their prognostic relevance in KRAS-mutated AC. We show that aberrant KRAS activity generates a vulnerability of AC cancer cell lines to both MTHFD2 and EZH2 inhibitors. Importantly, co-inhibition of both factors was synergistically effective and comparable to KRASG12C inhibition alone, paving the way for their use in a therapeutic approach for NSCLC cancer patients.
HS-SPME-GC/MS Analysis for Revealing Carob’s Ripening
Authors: Fella Panagiota , Kaikiti Kyriaki , Stylianou Marinos , Agapiou Agapios
Published: July 2022

Carob’s recognized nutritional and medicinal value next to its unique agriculture importance is associated with an array of social, economic, and cultural activities. The carob fruit is popular for its intense aroma due to the emitted volatile organic compounds (VOCs). The composition of VOCs released from carob fruits changes during ripening, rendering it a non-invasive tool for the determination of the ripening period and freshness of the fruit. Therefore, headspace solid-phase microextraction gas chromatography/mass spectrometry (HS-SPME-GC/MS) was applied to reveal the respective gaseous signal molecules related to fruit maturity. The sampling was implemented during weeks 26–36 from five different locations in Cyprus. Additionally, the gaseous emissions of total VOCs (TVOCs) and carbon dioxide (CO2) were recorded next to the moisture content of the fruit. The major chemical classes in the ripening are acids, followed by esters, and ketones. More specifically, the most abundant VOCs during ripening are propanoic acid, 2-methyl-(isobutyric acid), 2-heptanone, propanoic acid, 2-methyl-, 2-methylbutyl ester, acetic acid, methyl isobutyrate, propanoic acid, 2-methyl-, 3-methylbutyl ester, 2-pentanone, butanoic acid and propanoic acid, 2-methyl-ethyl ester. Finally, CO2 emissions and moisture content showed a rapid decline until the 31st week and then stabilized for all examined areas. The methodology revealed variations in VOCs’ profile during the ripening process.
Placental Characteristics of a Large Italian Cohort of SARS-CoV-2-Positive Pregnant Women
Authors: Salvatore Michele Antonio , Corsi Decenti Edoardo , Bonasoni Maria Paola , Botta Giovanni , Castiglione Francesca , D’Armiento Maria , Fulcheri Ezio , Nebuloni Manuela , Donati Serena ,   the ItOSS COVID-19 Working Group
Published: July 2022

The variety of placental morphological findings with SARS-CoV-2 maternal infections has raised the issue of poor agreement in histopathological evaluation. The aims of this study were: to describe the histopathological placental features of a large sample of SARS-CoV-2-positive women who gave birth in Italy during the COVID-19 pandemic, to analyse the factors underlying these lesions, and to analyse the impact of placental impairment on perinatal outcomes. From 25 February 2020 to 30 June 2021, experienced perinatal pathologists examined 975 placentas of SARS-CoV-2-positive mothers enrolled in a national prospective study, adopting the Amsterdam Consensus Statement protocol. The main results included the absence of specific pathological findings for SARS-CoV-2 infections, even though a high proportion of placentas showed signs of inflammation, possibly related to a cytokine storm induced by the virus, without significant perinatal consequences. Further research is needed to better define the clinical implications of placental morphology in SARS-CoV-2 infections, but the results of this large cohort suggest that placentas do not seem to be a preferential target for the new Coronavirus infection.
Aerobic Degradation Characteristics of Decabromodiphenyl ether through Rhodococcus ruber TAW-CT127 and Its Preliminary Genome Analysis
Authors: Xu Hao , Cai Qingtao , An Qiuying , Tang Chen , Wang Wanpeng , Wang Guangshun , You Wanting , Guo Dongbei , Zhao Ran
Published: July 2022

Decabromodiphenyl ether (BDE-209), a polybrominated diphenyl ether (PBDE) homolog, seriously threatens human health. In this study, a Rhodococcus ruber strain with high BDE-209 degradation activity, named TAW-CT127, was isolated from Tong’an Bay, Xiamen. Under laboratory conditions, the strain’s optimal growth temperature, pH, and salinity are 45 °C, 7.0, and 0–2.5%, respectively. Scanning electron microscopy (SEM) analysis shows that TAW-CT127 is damaged when grown in manual marine culture (MMC) medium with BDE-209 as the sole carbon source instead of eutrophic conditions. In the dark, under the conditions of 28 °C, 160 rpm, and 3 g/L (wet weight) TAW-CT127, the degradation rate of 50 mg/L BDE-209 is 81.07%. The intermediate metabolites are hexabromo-, octabromo-, and nonabromo-diphenyl ethers. Through whole-genome sequencing, multiple dehalogenases were found in the genome of TAW-CT127; these may be involved in the production of lower-brominated diphenyl ethers. Additionally, biphenyl-2,3-dioxygenase (BDO) in TAW-CT127 may catalyze the debromination reaction of BDE-209. Our research provides a new high-efficiency strain for bioremediation of BDE-209 pollution, and lays the foundation for the preliminary exploration of genes associated with BDE-209 degradation.
Retrospective Investigation of the Whole Genome of the Hypovirulent Listeria monocytogenes Strain of ST201, CC69, Lineage III, Isolated from a Piglet with Fatal Neurolisteriosis
Authors: Zaitsev Sergey S. , Khizhnyakova Mariya A. , Feodorova Valentina A.
Published: July 2022

Listeria monocytogenes (Lm), the causative agent for both human and animal listeriosis, is considered to be a rare but potentially fatal foodborne pathogen. While Lm strains associated with current cases of human listeriosis are now being intensely investigated, our knowledge of this microorganism which has caused listerial infection in the past is still extremely limited. The objective of this study was a retrospective whole-genome sequence analysis of the Lm collection strain, 4/52-1953, isolated in the middle of the 20th century from a piglet with listerial neuroinfection. The multi-locus sequence typing (MLST) analysis based on seven housekeeping genes (abcZ, bglA, cat, dapE, dat, ldh, and lhkA) showed that the Lm strain 4/52-1953 was assigned to the sequence type 201 (ST201), clonal complex 69 (CC69), and phylogenetic lineage III. The strain 4/52-1953, similarly to other ST201 strains, probably originated from the ST9, CC69 via ST157. At least eight different STs, ST69, ST72, ST130, ST136, ST148, ST469, ST769, and ST202, were identified as the descendants of the first generation and a single one, ST2290, was proved to be the descendant of the second generation. Among them there were strains either associated with some sporadic cases of human and animal listerial infection in the course of more than 60 years worldwide or isolated from food samples, fish and dairy products, or migratory birds. Phylogenetic analysis based on whole genomes of all the Lm strains available in the NCBI GenBank (n = 256) demonstrated that the strain 4/52-1953 belonged to minor Cluster I, represented by lineage III only, while two other major Clusters, II and III, were formed by lineages I and II. In the genome of the strain 4/52-1953, 41 virulence-associated genes, including the Listeria pathogenicity island 1 (LIPI-1), and LIPI-2 represented by two internalin genes, the inlA and inlB genes, and five genes related to antibiotic resistance, were found. These findings can help to make the emergence of both hyper- and hypovirulent variants, including those bearing antibiotic resistance genes, more visible and aid the aims of molecular epidemiology as well.
Detection of Tahyna Orthobunyavirus-Neutralizing Antibodies in Patients with Neuroinvasive Disease in Croatia
Authors: Vilibic-Cavlek Tatjana , Stevanovic Vladimir , Savic Vladimir , Markelic Domagoj , Sabadi Dario , Bogdanic Maja , Kovac Snjezana , Santini Marija , Tabain Irena , Potocnik-Hunjadi Tanja , Ferencak Ivana , Skoda Ana Marija , Sankovic Ana , Barbic Ljubo
Published: July 2022

Background: Tahyna orthobunyavirus (TAHV) is widely distributed in continental Europe. Very few studies have analyzed TAHV seroprevalence in Croatia. We analyzed the prevalence of TAHV RNA and antibodies in Croatian patients with neuroinvasive disease (NID). Methods: A total of 218 patients with unsolved NID detected during five consecutive arbovirus transmission seasons (April 2017–October 2021) were tested. Cerebrospinal fluid (CSF) and urine samples were tested for TAHV RNA using RT-PCR. In addition, CSF and serum samples were tested for TAHV antibodies using a virus neutralization test (VNT). Results: Clinical presentations in patients with NID were meningitis (141/64.7%), meningoencephalitis (56/25.7%), myelitis (8/3.7%), and ‘febrile headache’ (13/5.9%). TAHV RNA was not detected in any of the tested CSF or urine samples; however, TAHV-neutralizing (NT) antibodies were detected in 22/10.1% of patients. Detection of NT antibodies in the CSF of two patients presenting with meningitis suggested recent TAHV infection. TAHV seropositivity increased significantly with age, from 1.8% to 24.4%. There was no difference in seroprevalence between genders or areas of residence (urban, suburban/rural). The majority of seropositive patients (90.9%) resided in floodplains along the rivers in continental Croatia. Conclusions: The presented results confirm that TAHV is present in Croatia. The prevalence and clinical significance of TAHV infection in the Croatian population have yet to be determined.
Low-Temperature Flotation Separation of Diaspore from Kaolinite by Using a Mixed Collector
Authors: Man Xiaofei , Wang Chenliang , Yu Shichao , Yang Xiaofeng , Liu Jianjun , Fu Yafeng , Dong Zhenhai , Zhi Hui , Ou Leming
Published: July 2022

In this paper, the effect of a new mixed collector sodium oleate (NaOl)/tert dodecyl mercaptan (TDM) on the separation of diaspore and kaolinite at 283 K was investigated. The molar ratio of NaOl to TDM is 8:2. The properties of the mixed collector and its adsorption mechanism on diaspore and kaolinite were studied by surface tension measurements, Zeta potential determinations and XPS analysis. The flotation results show that the mixed collector NaOl/TDM has a good collection ability for diaspore and a good selectivity for kaolinite at low temperatures. Therefore, the mixed collector NaOl/TDM can effectively separate diaspore and kaolinite under alkaline conditions at 283 K. The results of surface tension measurements show that the molecular density, hydrophobic association ability and collection ability of the mixed collector NaOl/TDM are better than those of the single collector at 283 K. In addition, the formation of a micelle effect of the mixed collector NaOl/TDM has a synergistic effect, which improves the reagent activity at low temperatures with the flotation effect enhanced. The results of the Zeta potential determinations and XPS analysis show that the total adsorption capacity of the mixed collector NaOl/TDM on the surface of the diaspore at low temperatures is higher than that of NaOl, and the adsorption capacity on the surface of kaolinite is similar to that of NaOl. The mixed collector NaOl/TDM may be adsorbed on the surface of diaspore and kaolinite by a hydrogen bond at 283 K.
Mechanism of the Enrichment and Loss Progress of Deep Shale Gas: Evidence from Fracture Veins of the Wufeng–Longmaxi Formations in the Southern Sichuan Basin
Authors: Tan Ran , Wang Ruyue , Huang Yahao , Yang Rui , Li Hongbo , Lu Kuan
Published: July 2022

Natural fractures caused by tectonic stress in shale can not only improve the seepage capacity of shale, but also become the migration and loss channel of free gas. Calcite, quartz and other minerals in shale fracture veins record the fluid evolution information of the shale. Through the analysis of different types of fracture cements in the shale of the Silurian–Ordovician Wufeng–Longmaxi Formations in the southern Sichuan Basin, the effect of different fractures on shale gas construction or destruction was clarified. Geochemical investigations included the diagenetic mineral sequences in the hole–cavity veins, paleo-pressure recovery by Raman quantitative analysis, and the environments of diagenetic fluids traced by rare earth elements (REE) signatures. The density, composition, pressure, and temperature properties of CH4-bearing fluid inclusions were determined by Raman quantitative measurement and thermodynamic simulations to establish the trapping condition of the geo-fluids, and so constrain the periods of gas accumulation. The diagenetic sequences in the fracture veins can be summarized as follows: Cal-I→Qz-II→Cal-III. The Cal-I in the bedding fracture veins crystallized in the late Jurassic (~180 Ma), and originated from hydrothermal origin and diagenetic fluid; the Qz-II veins crystallized in the middle Jurassic (~190 Ma); the Cal-III veins in the high-angle fractures precipitated during the early Eocene (~12 Ma), and derived from atmospheric freshwater leaching. Pore fluid pressure gradually increased. The pressure coefficient of the shale gas reservoir gradually increased to strong overpressure from 160 Ma to 86 Ma. Between 75 Ma and the present day, the pore fluid pressure and the pressure coefficient in the shale reservoirs, having been affected by tectonic activities and strata uplift-erosion, have significantly reduced. Bedding slippage fractures play a constructive role in the enrichment of shale gas, and fracture slip can significantly improve fracture permeability. High-angle shear fractures usually cut through different strata in areas with strong tectonic activity, and destroy the sealing of the shale. The entrapment of primary methane gas inclusions recorded the process of excess reservoir pressure reduction, and indicated the partial loss of shale free gas.
In Situ U-Pb Geochronology of Calcite from the World’s Largest Antimony Deposit at Xikuangshan, Southern China
Authors: Xu Junwei , Liu Xianghua , Lai Jianqing , He Hongsheng , Song Xiangfa , Zhai Degao , Li Bin , Wang Yuhua , Shi Jian , Zhou Xi
Published: July 2022

The Xikuangshan antimony (Sb) deposit is the world’s largest known Sb deposit. Due to the lack of suitable minerals for reliable high-precision radiometric dating, it remains difficult to determine the exact age of Sb mineralization in this deposit. Here, we report the first LA-MC-ICP-MS U-Pb ages of syn-stibnite calcite from this deposit. The dating results indicate the presence of at least two stages of Sb mineralization in the Xikuangshan ore district. The calcite-stibnite veins in the Daocaowan ore block probably formed during the Paleocene (58.1 ± 0.9 Ma), representing an early stage of Sb mineralization, while the quartz-stibnite vein in the Feishuiyan ore block probably formed during the Eocene (50.4 ± 4.4 Ma, 50.4 ± 5.0 Ma, and 51.9 ± 1.6 Ma), representing a late stage of Sb mineralization. The new calcite U-Pb ages are significantly younger than the calcite Sm-Nd ages (124.1 ± 3.7 Ma, 155.5 ± 1.1 Ma) reported by previous researchers. We suggest that Sb mineralization of the South China antimony metallogenic belt may be related to tectono-thermal events during Paleogene, possibly linked to high heat flow during the subduction (ca. 60–40 Ma) of the Pacific Plate beneath the Eurasian Plate and/or the Indo–Asian Collision (began at ca. 61 Ma). The young in situ U-Pb ages of calcite challenge the idea of late Mesozoic Sb mineralization in the South China antimony metallogenic belt, suggesting the requirement for more high-precision dating studies.
Speculation on How RIC-3 and Other Chaperones Facilitate α7 Nicotinic Receptor Folding and Assembly
Authors: Loring Ralph H.
Published: July 2022

The process of how multimeric transmembrane proteins fold and assemble in the endoplasmic reticulum is not well understood. The alpha7 nicotinic receptor (α7 nAChR) is a good model for multimeric protein assembly since it has at least two independent and specialized chaperones: Resistance to Inhibitors of Cholinesterase 3 (RIC-3) and Nicotinic Acetylcholine Receptor Regulator (NACHO). Recent cryo-EM and NMR data revealed structural features of α7 nAChRs. A ser-ala-pro (SAP) motif precedes a structurally important but unique “latch” helix in α7 nAChRs. A sampling of α7 sequences suggests the SAP motif is conserved from C. elegans to humans, but the latch sequence is only conserved in vertebrates. How RIC-3 and NACHO facilitate receptor subunits folding into their final pentameric configuration is not known. The artificial intelligence program AlphaFold2 recently predicted structures for NACHO and RIC-3. NACHO is highly conserved in sequence and structure across species, but RIC-3 is not. This review ponders how different intrinsically disordered RIC-3 isoforms from C. elegans to humans interact with α7 nAChR subunits despite having little sequence homology across RIC-3 species. Two models from the literature about how RIC-3 assists α7 nAChR assembly are evaluated considering recent structural information about the receptor and its chaperones.
Determination of 241Am in Environmental Samples: A Review
Authors: Zhang Haitao , Hou Xiaolin , Qiao Jixin , Lin Jianfeng
Published: July 2022

The determination of 241Am in the environment is of importance in monitoring its release and assessing its environmental impact and radiological risk. This paper aims to give an overview about the recent developments and the state-of-art analytical methods for 241Am determination in environmental samples. Thorough discussions are given in this paper covering a wide range of aspects, including sample pre-treatment and pre-concentration methods, chemical separation techniques, source preparation, radiometric and mass spectrometric measurement techniques, speciation analyses, and tracer applications. The paper focuses on some hyphenated separation methods based on different chromatographic resins, which have been developed to achieve high analytical efficiency and sample throughput for the determination of 241Am. The performances of different radiometric and mass spectrometric measurement techniques for 241Am are evaluated and compared. Tracer applications of 241Am in the environment, including speciation analyses of 241Am, and applications in nuclear forensics are also discussed.
Asymmetric AZA-BODIPY with Optical Gain in the Near-Infrared Region
Authors: Virgili Tersilla , Ganzer Lucia , Botta Chiara , Squeo Benedetta Maria , Pasini Mariacecilia
Published: July 2022

In recent years, there has been a lot of interest in the development of organic compounds emitting in the near-infrared (NIR) region due to their stimulating applications, such as biosensing and light detection and ranging (LiDAR). Moreover, a lot of effort has been devoted to finding organic emitters with optical gain in the NIR region for lasing applications. In this paper, we present the ultrafast spectroscopy of an asymmetric AZA-BODIPY molecule that shows relevant photophysical changes moving from a diluted solution to a concentrated solution and to a spin-coated film. The diluted solution and the spin-coated film show a bleaching band and a stimulated emission band in the visible region, while the very concentrated solution displays a broad (150 nm) and long-living (more than 400 ps) optical gain band in the NIR region, centered at 900 nm. Our results pave the way for a new organic laser system in a near-infrared spectral region.
Metabolomic Profiling and Molecular Networking of Nudibranch-Associated Streptomyces sp. SCSIO 001680
Authors: Abdelrahman Samar M. , Dosoky Noura S. , Hanora Amro M. , Lopanik Nicole B.
Published: July 2022

Antibiotic-resistant bacteria are the primary source of one of the growing public health problems that requires global attention, indicating an urgent need for new antibiotics. Marine ecosystems are characterized by high biodiversity and are considered one of the essential sources of bioactive chemical compounds. Bacterial associates of marine invertebrates are commonly a source of active medicinal and natural products and are important sources for drug discovery. Hence, marine invertebrate-associated microbiomes are a fruitful resource for excavating novel genes and bioactive compounds. In a previous study, we isolated Streptomyces sp. SCSIO 001680, coded as strain 63, from the Red Sea nudibranch Chromodoris quadricolor, which exhibited antimicrobial and antitumor activity. In addition, this isolate harbors several natural product biosynthetic gene clusters, suggesting it has the potential to produce bioactive natural products. The present study aimed to investigate the metabolic profile of the isolated Streptomyces sp. SCSIO 001680 (strain 63) and to predict their potential role in the host’s survival. The crude metabolic extracts of strain 63 cultivated in two different media were characterized by ultra-high-performance liquid chromatography and high-resolution mass spectrometry. The metabolomics approach provided us with characteristic chemical fingerprints of the cellular processes and the relative abundance of specific compounds. The Global Products Social Molecular Networking database was used to identify the metabolites. While 434 metabolites were detected in the extracts, only a few compounds were identified based on the standards and the public spectral libraries, including desferrioxamines, marineosin A, and bisucaberin, halichoblelide, alternarin A, pachastrelloside A, streptodepsipeptide P1 1B, didemnaketal F, and alexandrolide. This finding suggests that this strain harbors several novel compounds. In addition, the metabolism of the microbiome of marine invertebrates remains poorly represented. Thus, our data constitute a valuable complement to the study of metabolism in the host microbiome.
α-Hydroxylactams as Efficient Entries to Diversely Functionalized Ferrociphenols: Synthesis and Antiproliferative Activity Studies
Authors: Pigeon Pascal , Gaschard Marie , Othman Mohamed , Salmain Michèle , Jaouen Gérard
Published: July 2022

The [ferrocene-ene-phenol] motif has been identified as the pharmacophore responsible for the anticancer activity of the family of ferrocene-based molecules coined ferrocifens, owing to its unique redox properties. The addition of imide entities to the historical ferrociphenol scaffold tremendously enhanced the cytotoxic activity of a large panel of cancer cell cultures and preliminary studies showed that the reduction of one of the carbonyl groups of the imide groups to the corresponding α-hydroxylactams only slightly affected the antiproliferative activity. As a continuation to these studies, we took advantage of the facile conversion of α-hydroxylactams to highly electrophilic N-acyliminium ions to graft various substituents to the imide motif of phthalimido ferrocidiphenol. Cell viability studies showed that the newly synthesized compounds showed diverse cytotoxic activities on two breast cancer cell lines, while only one compound was significantly less active on the non-tumorigenic cell line hTERT-RPE1.
Toxic Effect of Fullerene and Its Derivatives upon the Transmembrane β2-Adrenergic Receptors
Authors: Ren Longlong , Jing Zhenxiang , Xia Fei , Zhang John Zenghui , Li Yang
Published: July 2022

Numerous experiments have revealed that fullerene (C60) and its derivatives can bind to proteins and affect their biological functions. In this study, we explored the interaction between fullerine and the β2-adrenergic receptor (β2AR). The MD simulation results show that fullerene binds with the extracellular loop 2 (ECL2) and intracellular loop 2 (ICL2) of β2AR through hydrophobic interactions and π–π stacking interactions. In the C60_in1 trajectory, due to the π–π stacking interactions of fullerene molecules with PHE and PRO residues on ICL2, ICL2 completely flipped towards the fullerene direction and the fullerene moved slowly into the lipid membrane. When five fullerene molecules were placed on the extracellular side, they preferred to stack into a stable fullerene cluster (a deformed tetrahedral aggregate), and had almost no effect on the structure of β2AR. The hydroxyl groups of fullerene derivatives (C60(OH)X, X represents the number of hydroxyl groups, X = 4, 8) can form strong hydrogen bonds with the ECL2, helix6, and helix7 of β2AR. The hydroxyl groups firmly grasp the β2AR receptor like several claws, blocking the binding entry of ligands. The simulation results show that fullerene and fullerene derivatives may have a significant effect on the local structure of β2AR, especially the distortion of helix4, but bring about no great changes within the overall structure. It was found that C60 did not compete with ligands for binding sites, but blocked the ligands’ entry into the pocket channel. All the above observations suggest that fullerene and its derivatives exhibit certain cytotoxicity.
Structural Investigation of Magnesium Complexes Supported by a Thiopyridyl Scorpionate Ligand
Authors: Stevens Matthew P. , Spray Emily , Vitorica-Yrezabal Iñigo J. , Singh Kuldip , Timmermann Vanessa M. , Sotorrios Lia , Ortu Fabrizio
Published: July 2022

Herein, we report the synthesis of a series of heteroleptic magnesium complexes stabilized with the scorpionate ligand tris(2-pyridylthio)methanide (Tptm). The compounds of the general formula [Mg(Tptm)(X)] (1-X; X = Cl, Br, I) were obtained via protonolysis reaction between the proligand and selected Grignard reagents. Attempts to isolate the potassium derivative K(Tptm) lead to decomposition of Tptm and formation of the alkene (C5H4N-S)2C=C(C5H4N-S)2, and this degradation was also modelled using DFT methods. Compound 1-I was treated with K(CH2Ph), affording the degradation product [Mg(Bptm)2] (2; Bptm = {CH(S-C5NH3)2}−). We analyzed and quantified the steric properties of the Tptm ligand using the structural information of the compounds obtained in this study paired with buried volume calculations, also adding the structural data of HTptm and its CF3-substituted congener (HTptmCF3). These studies highlight the highly flexible nature of this ligand scaffold and its ability to stabilize various coordination motifs and geometries, which is a highly desirable feature in the design of novel organometallic reagents and catalysts.
First-Principles Study of Irn (n = 3–5) Clusters Adsorbed on Graphene and Hexagonal Boron Nitride: Structural and Magnetic Properties
Authors: Ge Mei , Chu Leiting , Guo Miaomiao , Su Yan , Zhang Junfeng
Published: July 2022

Magnetic clusters have attracted great attention and interest due to their novel electronic properties, and they have potential applications in nanoscale information storage devices and spintronics. The interaction between magnetic clusters and substrates is still one of the challenging research focuses. Here, by using the density functional theory (DFT), we study the structural stability and magnetic properties of iridium clusters (Irn, n = 3–5) adsorbed on two-dimensional (2D) substrates, such as graphene and hexagonal boron nitride (hBN). We find that the most favorable configurations of free Irn clusters change when adsorbed on 2D substrates. In the meantime, the magnetic moments of the most stable Irn reduce to 53% (graphene) and 23.6% (hBN) compared with those of the free−standing ones. Interestingly, about 12-times enlargement on the magnetic anisotropy energy can be found on hBN substrates. These theoretical results indicate that the cluster–substrate interaction has vital effects on the properties of Irn clusters.
Polarization Control in Integrated Silicon Waveguides Using Semiconductor Nanowires
Authors: Kaplan Ali Emre , Vitali Valerio , Demontis Valeria , Rossella Francesco , Fontana Andrea , Cornia Samuele , Petropoulos Periklis , Bellani Vittorio , Lacava Cosimo , Cristiani Ilaria
Published: July 2022

In this work, we show the design of a silicon photonic-based polarization converting device based on the integration of semiconduction InP nanowires on the silicon photonic platform. We present a comprehensive numerical analysis showing that full polarization conversion (from quasi-TE modes to quasi-TM modes, and vice versa) can be achieved in devices exhibiting small footprints (total device lengths below 20 µm) with minimal power loss (<2 dB). The approach described in this work can pave the way to the realization of complex and re-configurable photonic processors based on the manipulation of the state of polarization of guided light beams.
Optical Bistability in a Tunable Gourd-Shaped Silicon Ring Resonator
Authors: Chen Yishu , Feng Jijun , Chen Jian , Liu Haipeng , Yuan Shuo , Guo Song , Yu Qinghua , Zeng Heping
Published: July 2022

In this study, a tunable gourd-shaped ring resonator is demonstrated to generate optical bistability. The system consists of two sub-rings for a gourd shape configuration with a U-shaped wave guiding pathway. The transfer matrix method and FDTD simulation are used to acquire the spectral characteristics of the system. For the fabricated device, the spectra profile and extinction ratio can be effectively tuned by the microheater above the U-shaped waveguide, which matches with the theoretical results. Due to the gourd structure of the resonator, the light waves in two rings can be cross-coupled with each other, and the optical bistability could come out effectively with the change in the input optical power around 6 mW. The presented optical bistability devices have great application potential in optical information processing such as optical storage, switch and logic operation.
Green Synthesis of FexOy Nanoparticles with Potential Antioxidant Properties
Authors: Abdullah Johar Amin Ahmed , Jiménez-Rosado Mercedes , Perez-Puyana Víctor , Guerrero Antonio , Romero Alberto
Published: July 2022

Iron oxide nanoparticles (FexOy-NPs) are currently being applied in numerous high-tech sectors, such as in chemical sectors for catalysis and in the medical sector for drug delivery systems and antimicrobial purposes, due to their specific, unique and magnetic properties. Nevertheless, their synthesis is under continuous investigation, as physicochemical methods are considered expensive and require toxic solvents. Thus, green nanotechnology has shown considerable promise in the eco-biogenesis of nanoparticles. In the current study, FexOy-NPs were synthesized by two different methods: via green synthesis through the use of polyphenols, which were extracted from Phoenix dactylifera L.; and via chemical synthesis, in which the reducing agent was a chemical (NaOH), and iron chloride was used as a precursor. Thus, polyphenol extraction and its ability to produce nanoparticles were evaluated based on the drying temperature used during the Phoenix dactylifera L. recollection, as well as the extraction solvent used. The results highlight the potential of polyphenols present in Phoenix dactylifera L. for the sustainable manufacture of FexOy-NPs. Finally, green and chemical syntheses were compared on the basis of physicochemical characteristics and functional properties.
Pd-Modified LaFeO3 as a High-Efficiency Gas-Sensing Material for H2S Gas Detection
Authors: Zhang Heng , Xiao Jing , Chen Jun , Wang Yan , Zhang Lian , Yue Shuai , Li Suyan , Huang Tao , Sun Da
Published: July 2022

As a typical p-type semiconductor gas-sensing material, LaFeO3 has good response stability to H2S, but its responsiveness is low, and the detection limit is not low enough for large-scale use in the field of gas sensors. To obtain better performance, we synthesized Pd modified LaFeO3 using the sol–gel method. A total of 3 wt% of Pd–LaFeO3 with a high specific surface area had the highest response to H2S (36.29–1 ppm) at 120 °C, with relatively fast response–recovery times (19.62/15.22 s), and it had higher selectivity to H2S with other gases. Finally, we detected the H2S concentrations in the air around the shrimps, and the H2S concentrations that we obtained by the 3 wt% Pd–LaFeO3 in this study were within 10% of those obtained by GC–MS. According to the experimental results, noble-metal surface modification improves the performance of gas-sensing materials, and Pd–LaFeO3 has considerable potential in H2S detection.
Product of Two Laguerre–Gaussian Beams
Authors: Kotlyar Victor V. , Abramochkin Eugeny G. , Kovalev Alexey A. , Savelyeva Alexandra A.
Published: July 2022

We show that a product of two Laguerre–Gaussian (pLG) beams can be expressed as a finite superposition of conventional LG beams with particular coefficients. Based on such an approach, an explicit relationship is derived for the complex amplitude of pLG beams in the Fresnel diffraction zone. Two identical LG beams of the duet produce a particular case of a “squared” Fourier-invariant LG beam, termed as an (LG)2 beam. For a particular case of pLG beams described by Laguerre polynomials with azimuthal numbers n − m and n + m, an explicit expression for the complex amplitude in a Fourier plane is derived. Similar to conventional LG beams, the pLG beams can be utilized for information transmission, as they are characterized by orthogonal azimuthal numbers and carry an orbital angular momentum equal to their topological charge.
Management of Post-Harvest Anthracnose: Current Approaches and Future Perspectives
Authors: Ciofini Alice , Negrini Francesca , Baroncelli Riccardo , Baraldi Elena
Published: July 2022

Anthracnose is a severe disease caused by Colletotrichum spp. on several crop species. Fungal infections can occur both in the field and at the post-harvest stage causing severe lesions on fruits and economic losses. Physical treatments and synthetic fungicides have traditionally been the preferred means to control anthracnose adverse effects; however, the urgent need to decrease the use of toxic chemicals led to the investigation of innovative and sustainable protection techniques. Evidence for the efficacy of biological agents and vegetal derivates has been reported; however, their introduction into actual crop protection strategies requires the solutions of several critical issues. Biotechnology-based approaches have also been explored, revealing the opportunity to develop innovative and safe methods for anthracnose management through genome editing and RNA interference technologies. Nevertheless, besides the number of advantages related to their use, e.g., the putative absence of adverse effects due to their high specificity, a number of aspects remain to be clarified to enable their introduction into Integrated Pest Management (IPM) protocols against Colletotrichum spp. disease.
A Novel Bacillus safensis-Based Formulation along with Mycorrhiza Inoculation for Controlling Alternaria alternata and Simultaneously Improving Growth, Nutrient Uptake, and Steviol Glycosides in Stevia rebaudiana under Field Conditions
Authors: Prakash Jai , Egamberdieva Dilfuza , Arora Naveen Kumar
Published: July 2022

The excess use of chemicals by farmers in the agroecosystems degrades soil quality, disturbs soil ecology, and increases soil salinity and health hazards in humans. Stevia rebaudiana is an important medicinal and aromatic crop whose leaves contain steviol glycosides (SGs). The Bacillus safensis NAIMCC-B-02323 strain STJP from the rhizosphere of S. rebaudiana producing salicylic acid (16.80 µg/mL), chitinase (75.58 U/mL), β-1,3-glucanase (220.36 U/mL), and cellulase (170 U/mL) was taken as a plant growth-promoting rhizobacteria (PGPR). The cell-free supernatant (CFS) from strain STJP showed significant biocontrol activity against Alternaria alternata (80%), suggesting the protective role of extracellular metabolite(s) against phytopathogens. Paneer whey-based bioformulation (P-WBF) was developed to exploit B. safensis STJP to enhance the growth, nutrient uptake, soil properties, stevioside content, and SGs biosynthesis in S. rebaudiana under an A. alternata-infested field. The combined treatment of P-WBF and mycorrhiza (Glomus fasciculatum ABTEC) significantly enhanced plant growth parameters after 90 days, in comparison with control. The symbiotic action (P-WBF and mycorrhiza) displayed much better results in terms of chlorophyll a and b (improved by 132.85% and 39.80%, respectively), protein (by 278.75%), flavonoid (by 86.99%), carbohydrate (by 103.84%), antioxidant (by 75.11%), and stevioside (by 120.62%) contents in plants as compared to the untreated set. Further, the augmentation of potassium (by 132.39%), phosphorous (by 94.22%), and zinc (by 111.11%) uptake in plant tissues and soil was also observed by the application of P-WBF and mycorrhiza. The expression of UGT74G1 and UGT85C2 genes related to SG biosynthesis was upregulated (2.7- and 3.2-fold, respectively) in plants treated with P-WBF and mycorrhiza as further confirmed by the accumulation of SGs. The results suggest that the application of P-WBF and mycorrhiza not only provides an ecofriendly and sustainable solution to improve stevioside content in S. rebaudiana by a nutrient-linked mechanism but also paves the way to enhanced production of stevioside.
The Effect of Frankia and Hebeloma crustiliniforme on Alnus alnobetula subsp. Crispa Growing in Saline Soil
Authors: Chen Haoran , Renault Sylvie , Markham John
Published: July 2022

The mining of the oil sands region of Canada’s boreal forest creates disturbed land with elevated levels of salts. Understanding how native plants respond to salt stress is critical in reclaiming these lands. The native species, Alnus alnobetula subsp. crispa forms nitrogen-fixing nodules with Frankia, and ectomycorrhizae with a number of fungal species. These relationships may make the plant particularly well suited for restoring disturbed land. We inoculated A. alnobetula subsp. crispa with Frankia and Hebeloma crustiliniforme and exposed the plants to 0, 50, or 100 mM NaCl for seven weeks. Frankia-inoculated plants had increased biomass regardless of salt exposure, even though salt exposure reduced nitrogen fixation and reduced the efficiency of nitrogen-fixing nodules. The nitrogen-fixing symbiosis also decreased leaf stress and increased root phosphatase levels. This suggests that N-fixing plants not only have increased nitrogen nutrition but also have increased access to soil phosphorus. Mycorrhizae did not affect plant growth but did reduce nodule numbers and nodule efficiency. These results suggest that the nitrogen-fixing trait is more critical than mycorrhizae. While salt stress inhibits nitrogen-fixing symbiosis, plants still benefit from nitrogen fixation when exposed to salt.
Unsteady Natural Convection in an Initially Stratified Air-Filled Trapezoidal Enclosure Heated from Below
Authors: Rahaman Md. Mahafujur , Bhowmick Sidhartha , Mondal Rabindra Nath , Saha Suvash C.
Published: July 2022

Natural convection is intensively explored, especially in a valley-shaped trapezoidal enclosure, because of its broad presence in both technical settings and nature. This study deals with a trapezoidal cavity, which is initially filled with linearly stratified air. Although the sidewalls remain adiabatic, the bottom wall is heated, and the top wall is cooled. For the stratified fluid (air), the temperature of the fluid adjacent to the top and the bottom walls is the same as that of the walls. Natural convection in the trapezoidal cavity is simulated in two dimensions using numerical simulations, by varying Rayleigh numbers (Ra) from 100 to 108 with constant Prandtl number, Pr = 0.71, and aspect ratio, A = 0.5. The numerical results demonstrate that the development of natural convection from the beginning is dependent on the Rayleigh numbers. According to numerical results, the development of transient flow within the enclosure owing to the predefined conditions for the boundary may be categorized into three distinct stages: early, transitional, and steady or unsteady. The flow characteristics at each of the three phases and the impact of the Rayleigh number on the flow’s growth are quantified. Unsteady natural convection flows in the enclosure are described and validated by numerical results. In addition, heat transfer through the bottom and the top surfaces is described in this study.
A Comparative Analysis of Machine Learning Models in Prediction of Mortar Compressive Strength
Authors: Gayathri Rajakumaran , Rani Shola Usha , Čepová Lenka , Rajesh Murugesan , Kalita Kanak
Published: July 2022

Predicting the mechanical properties of cement-based mortars is essential in understanding the life and functioning of structures. Machine learning (ML) algorithms in this regard can be especially useful in prediction scenarios. In this paper, a comprehensive comparison of nine ML algorithms, i.e., linear regression (LR), random forest regression (RFR), support vector regression (SVR), AdaBoost regression (ABR), multi-layer perceptron (MLP), gradient boosting regression (GBR), decision tree regression (DT), hist gradient boosting regression (hGBR) and XGBoost regression (XGB), is carried out. A multi-attribute decision making method called TOPSIS (technique for order of preference by similarity to ideal solution) is used to select the best ML metamodel. A large dataset on cement-based mortars consisting of 424 sample points is used. The compressive strength of cement-based mortars is predicted based on six input parameters, i.e., the age of specimen (AS), the cement grade (CG), the metakaolin-to-total-binder ratio (MK/B), the water-to-binder ratio (W/B), the superplasticizer-to-binder ratio (SP) and the binder-to-sand ratio (B/S). XGBoost regression is found to be the best ML metamodel while simple metamodels like linear regression (LR) are found to be insufficient in handling the non-linearity in the process. This mapping of the compressive strength of mortars using ML techniques will be helpful for practitioners and researchers in identifying suitable mortar mixes.
The Assessment of Anticancer and VEGFR-2 Inhibitory Activities of a New 1H-Indole Derivative: In Silico and In Vitro Approaches
Authors: Elkaeed Eslam B. , Yousef Reda G. , Elkady Hazem , Gobaara Ibraheem M. M. , Alsfouk Aisha A. , Husein Dalal Z. , Ibrahim Ibrahim M. , Metwaly Ahmed M. , Eissa Ibrahim H.
Published: July 2022

Corresponding to the reported features of anti-VEGFR-2-approved compounds, a new 1H-indole derivative (compound 7) was designed. The inhibitory potential of the designed compound was revealed via a molecular docking study that showed the appropriate binding. Then, MD simulation (six studies) over a period of 100 ns was performed to confirm the precise binding and optimum energy. Additionally, MM-GBSA reaffirmed the perfect binding, exhibiting a total precise energy of −40.38 Kcal/Mol. The MM-GBSA experiments named the essential amino acids in the protein–ligand interaction, employing the binding energy decomposition and revealing the diversity of interactions of compound 7 inside the VEGFR-2 enzyme. As compound 7 is new, DFT experiments were utilized for molecular structure optimization. Additionally, the DFT results validated the coherent interaction of compound 7 with the VEGFR-2 enzyme. A good value of drug-likeness of compound 7 was acknowledged via in silico ADMET studies. Interestingly, the experimental in vitro prohibitory potential of compound 7 was better than that of sorafenib, demonstrating an IC50 value of 25 nM. Notably, the strong inhibitory effects of compound 10 against two cancer cell lines (MCF-7 and HCT 116) were established with IC50 values of 12.93 and 11.52 μM, disclosing high selectivity indexes of 6.7 and 7.5, respectively.
Kinetic Modeling of Quality Changes and Shelf Life Prediction of Dried Coconut Chips
Authors: Choosuk Natthaya , Meesuk Pattarawadee , Renumarn Phanida , Phungamngoen Chanthima , Jakkranuhwat Nattakan
Published: July 2022

The color, texture and rancidity of dried fruit are critical parameters to control for consumer acceptance. The goal of this research was to investigate the kinetics of color parameter changes and texture in terms of the crispness and peroxide value (PV) of dried coconut chips by using zero-, first- and second-order kinetic reactions during storage at different temperatures, as well as shelf life prediction using the accelerated method. The outcomes demonstrated that the zero-order kinetic reaction was appropriate to describe the change in color, crispness and PV of dried coconut chips during storage (R2 = 0.9690–0.9899). The rancidity had a higher correlation than the texture and color changes used to assign the quality essence. The activation energy (Ea) for the PV change was 11.83 kJ/mol. Therefore, the shelf life expectancy of the dried coconut chips was estimated to be 144, 128 and 115 days at 35, 45 and 55 °C, respectively. Meanwhile, the shelf life of products stored at ambient temperature was 159 days, and those products were stored in the refrigerator for 194 days. The findings provide retailers and consumers the ability to choose the ideal temperature and storage time for dried coconut chips in order to ensure the product’s quality.
Measuring Total Sulphur Amount Fraction at picomol/mol in Hydrogen Fuel: New Results from cryo-GC-SCD Analytical Method
Authors: Bacquart Thomas , Morris Abigail Siân Olivia , Bartlett Sam , Kjos Ole , Murugan Arul , Storms Ward
Published: July 2022

Fuel cell electric vehicles are expanding quickly from light-duty to heavy-duty applications such as buses or trucks. Hydrogen fuel quality needs to comply with ISO14687:2019 to avoid any improper performance of the vehicles. Total sulphur is one of the most impactful contaminants to a fuel cell system and has a threshold of 4 nmol/mol. Most analytical methods provide a limit of detection (LOD) of 1 nmol/mol for total sulphur in hydrogen. Total sulphur is often not quantified and reported as below LOD due to lack of sensitivity. A new analytical method using cryo-focussing gas chromatography with sulphur chemiluminescence detector (cryo-GC-SCD) was developed for picomol/mol analysis of total sulphur. The method achieved linearity between 150–16,000 picomol/mol, validated against NPL reference materials, and relative expanded uncertainty of 21% (k = 2). Samples from 11 hydrogen refuelling stations (HRS) were analysed using this method. The total sulphur amount fraction for all the HRSs was more than 10 times lower than the actual ISO14687:2019 threshold with highest value around 290 picomol/mol. The study demonstrated that the cryo-GC-SCD method can measure total sulphur at picomol/mol in hydrogen fuel. Additionally, it provided the first results on sulphur compound stability in an aluminium gas cylinder for which further study is needed.