bluuebunny/crossref_metadata_2025 huggingface dataset:
Melatonin’s neuroprotective role in mitochondria and its potential as a biomarker in aging, cognition and psychiatric disorders
Authors: Melhuish Beaupre Lindsay M. , Brown Gregory M. , Gonçalves Vanessa F. , Kennedy James L.
Published: June 2021

Melatonin is an ancient molecule that is evident in high concentrations in various tissues throughout the body. It can be separated into two pools; one of which is synthesized by the pineal and can be found in blood, and the second by various tissues and is present in these tissues. Pineal melatonin levels display a circadian rhythm while tissue melatonin does not. For decades now, melatonin has been implicated in promoting and maintaining sleep. More recently, evidence indicates that it also plays an important role in neuroprotection. The beginning of our review will summarize this literature. As an amphiphilic, pleiotropic indoleamine, melatonin has both direct actions and receptor-mediated effects. For example, melatonin has established effects as an antioxidant and free radical scavenger both in vitro and in animal models. This is also evident in melatonin’s prominent role in mitochondria, which is reviewed in the next section. Melatonin is synthesized in, taken up by, and concentrated in mitochondria, the powerhouse of the cell. Mitochondria are also the major source of reactive oxygen species as a byproduct of mitochondrial oxidative metabolism. The final section of our review summarizes melatonin’s potential role in aging and psychiatric disorders. Pineal and tissue melatonin levels both decline with age. Pineal melatonin declines in individuals suffering from psychiatric disorders. Melatonin’s ability to act as a neuroprotectant opens new avenues of exploration for the molecule as it may be a potential treatment for cases with neurodegenerative disease.
Giant electrocaloric materials energy efficiency in highly ordered lead scandium tantalate
Authors: Nouchokgwe Youri , Lheritier Pierre , Hong Chang-Hyo , Torelló Alvar , Faye Romain , Jo Wook , Bahl Christian R. H. , Defay Emmanuel
Published: June 2021

Electrocaloric materials are promising working bodies for caloric-based technologies, suggested as an efficient alternative to the vapor compression systems. However, their materials efficiency defined as the ratio of the exchangeable electrocaloric heat to the work needed to trigger this heat remains unknown. Here, we show by direct measurements of heat and electrical work that a highly ordered bulk lead scandium tantalate can exchange more than a hundred times more electrocaloric heat than the work needed to trigger it. Besides, our material exhibits a maximum adiabatic temperature change of 3.7 K at an electric field of 40 kV cm−1. These features are strong assets in favor of electrocaloric materials for future cooling devices.
Dielectric nanohole array metasurface for high-resolution near-field sensing and imaging
Authors: Conteduca Donato , Barth Isabel , Pitruzzello Giampaolo , Reardon Christopher P. , Martins Emiliano R. , Krauss Thomas F.
Published: June 2021

Dielectric metasurfaces support resonances that are widely explored both for far-field wavefront shaping and for near-field sensing and imaging. Their design explores the interplay between localised and extended resonances, with a typical trade-off between Q-factor and light localisation; high Q-factors are desirable for refractive index sensing while localisation is desirable for imaging resolution. Here, we show that a dielectric metasurface consisting of a nanohole array in amorphous silicon provides a favourable trade-off between these requirements. We have designed and realised the metasurface to support two optical modes both with sharp Fano resonances that exhibit relatively high Q-factors and strong spatial confinement, thereby concurrently optimizing the device for both imaging and biochemical sensing. For the sensing application, we demonstrate a limit of detection (LOD) as low as 1 pg/ml for Immunoglobulin G (IgG); for resonant imaging, we demonstrate a spatial resolution below 1 µm and clearly resolve individual E. coli bacteria. The combined low LOD and high spatial resolution opens new opportunities for extending cellular studies into the realm of microbiology, e.g. for studying antimicrobial susceptibility.
Large intrinsic anomalous Hall effect in SrIrO3 induced by magnetic proximity effect
Authors: Yoo Myoung-Woo , Tornos J. , Sander A. , Lin Ling-Fang , Mohanta Narayan , Peralta A. , Sanchez-Manzano D. , Gallego F. , Haskel D. , Freeland J. W. , Keavney D. J. , Choi Y. , Strempfer J. , Wang X. , Cabero M. , Vasili Hari Babu , Valvidares Manuel , Sanchez-Santolino G. , Gonzalez-Calbet J. M. , Rivera A. , Leon C. , Rosenkranz S. , Bibes M. , Barthelemy A. , Anane A. , Dagotto Elbio , Okamoto S. , te Velthuis S. G. E. , Santamaria J. , Villegas Javier E.
Published: June 2021

The anomalous Hall effect (AHE) is an intriguing transport phenomenon occurring typically in ferromagnets as a consequence of broken time reversal symmetry and spin-orbit interaction. It can be caused by two microscopically distinct mechanisms, namely, by skew or side-jump scattering due to chiral features of the disorder scattering, or by an intrinsic contribution directly linked to the topological properties of the Bloch states. Here we show that the AHE can be artificially engineered in materials in which it is originally absent by combining the effects of symmetry breaking, spin orbit interaction and proximity-induced magnetism. In particular, we find a strikingly large AHE that emerges at the interface between a ferromagnetic manganite (La0.7Sr0.3MnO3) and a semimetallic iridate (SrIrO3). It is intrinsic and originates in the proximity-induced magnetism present in the narrow bands of strong spin-orbit coupling material SrIrO3, which yields values of anomalous Hall conductivity and Hall angle as high as those observed in bulk transition-metal ferromagnets. These results demonstrate the interplay between correlated electron physics and topological phenomena at interfaces between 3d ferromagnets and strong spin-orbit coupling 5d oxides and trace an exciting path towards future topological spintronics at oxide interfaces.
Numerical approximation to the effects of the atmospheric stability conditions on the dispersion of pollutants over flat areas
Authors: Huertas J. I. , Martinez D. S. , Prato D. F.
Published: June 2021

Using the Computational Fluid Dynamics technique (CFD), we explored the effects of the atmospheric stability conditions on the dispersion of solid and gas-phase pollutants emitted from an area source located on a flat region. As an application, the dispersion of pollutants emitted from roads located on flat terrains was considered. Toward that end, we set up a model that describes the dispersion of air pollutants in a small region (< 1 km long) near the ground surface (< 250 m high). It consists of a neutrally stratified model modified to account for the atmospheric stability effects by imposing the near-ground stratification through the Monin–Obukhov similarity theory and the k–ε turbulence model adjusted for each atmospheric stability condition. Using this model, we simulated the dispersion of pollutants emitted from the road and plotted the resulting downwind concentrations in terms of dimensionless numbers. Results from our CFD-based model were highly correlated (R2 > 0.95) with the SF6 concentrations measured downwind a line source of this trace gas by the U.S. National Oceanic Atmospheric Administration in 2008 under different conditions of atmospheric stability. Numerical and experimental results showed that, under any of the stability conditions explored, the near-road pollutant concentrations are highly correlated (R2 > 0.87) to the concentrations observed under neutral conditions. When the atmosphere is extremely stable, those concentrations were up to 12 times higher than those observed under neutral conditions. We report the constant of proportionality obtained for every stability condition.
Radius-optimized efficient template matching for lesion detection from brain images
Authors: Koley Subhranil , Dutta Pranab K. , Aganj Iman
Published: June 2021

Computer-aided detection of brain lesions from volumetric magnetic resonance imaging (MRI) is in demand for fast and automatic diagnosis of neural diseases. The template-matching technique can provide satisfactory outcome for automatic localization of brain lesions; however, finding the optimal template size that maximizes similarity of the template and the lesion remains challenging. This increases the complexity of the algorithm and the requirement for computational resources, while processing large MRI volumes with three-dimensional (3D) templates. Hence, reducing the computational complexity of template matching is needed. In this paper, we first propose a mathematical framework for computing the normalized cross-correlation coefficient (NCCC) as the similarity measure between the MRI volume and approximated 3D Gaussian template with linear time complexity, $${\mathbf{\mathcal{O}}}\left( {{\varvec{a}}_{{{\varvec{max}}}} {\varvec{N}}} \right)$$

O

a

max

N

, as opposed to the conventional fast Fourier transform (FFT) based approach with the complexity $${\mathbf{\mathcal{O}}}\left( {{\varvec{a}}_{{{\varvec{max}}}} {\varvec{N}}\log {\varvec{N}}} \right)$$

O

a

max

N

log

N

, where $${\varvec{N}}$$

N

is the number of voxels in the image and $${\varvec{a}}_{{{\varvec{max}}}}$$

a

max

is the number of tried template radii. We then propose a mathematical formulation to analytically estimate the optimal template radius for each voxel in the image and compute the NCCC with the location-dependent optimal radius, reducing the complexity to $${\mathbf{\mathcal{O}}}\left( {\varvec{N}} \right)$$

O

N

. We test our methods on one synthetic and two real multiple-sclerosis databases, and compare their performances in lesion detection with FFT and a state-of-the-art lesion prediction algorithm. We demonstrate through our experiments the efficiency of the proposed methods for brain lesion detection and their comparable performance with existing techniques.
An evaluation of the self-assembly enhancing properties of cell-derived hexameric amyloid-β
Authors: Vadukul Devkee M. , Vrancx Céline , Burguet Pierre , Contino Sabrina , Suelves Nuria , Serpell Louise C. , Quinton Loïc , Kienlen-Campard Pascal
Published: June 2021

A key hallmark of Alzheimer’s disease is the extracellular deposition of amyloid plaques composed primarily of the amyloidogenic amyloid-β (Aβ) peptide. The Aβ peptide is a product of sequential cleavage of the Amyloid Precursor Protein, the first step of which gives rise to a C-terminal Fragment (C99). Cleavage of C99 by γ-secretase activity releases Aβ of several lengths and the Aβ42 isoform in particular has been identified as being neurotoxic. The misfolding of Aβ leads to subsequent amyloid fibril formation by nucleated polymerisation. This requires an initial and critical nucleus for self-assembly. Here, we identify and characterise the composition and self-assembly properties of cell-derived hexameric Aβ42 and show its assembly enhancing properties which are dependent on the Aβ monomer availability. Identification of nucleating assemblies that contribute to self-assembly in this way may serve as therapeutic targets to prevent the formation of toxic oligomers.
Impact of fully automated assessment on interstudy reproducibility of biventricular volumes and function in cardiac magnetic resonance imaging
Authors: Backhaus Sören J. , Schuster Andreas , Lange Torben , Stehning Christian , Billing Marcus , Lotz Joachim , Pieske Burkert , Hasenfuß Gerd , Kelle Sebastian , Kowallick Johannes T.
Published: June 2021

Cardiovascular magnetic resonance (CMR) imaging provides reliable assessments of biventricular morphology and function. Since manual post-processing is time-consuming and prone to observer variability, efforts have been directed towards novel artificial intelligence-based fully automated analyses. Hence, we sought to investigate the impact of artificial intelligence-based fully automated assessments on the inter-study variability of biventricular volumes and function. Eighteen participants (11 with normal, 3 with heart failure and preserved and 4 with reduced ejection fraction (EF)) underwent serial CMR imaging at in median 63 days (range 49–87) interval. Short axis cine stacks were acquired for the evaluation of left ventricular (LV) mass, LV and right ventricular (RV) end-diastolic, end-systolic and stroke volumes as well as EF. Assessments were performed manually (QMass, Medis Medical Imaging Systems, Leiden, Netherlands) by an experienced (3 years) and inexperienced reader (no active reporting, 45 min of training with five cases from the SCMR consensus data) as well as fully automated (suiteHEART, Neosoft, Pewaukee, WI, USA) without any manual corrections. Inter-study reproducibility was overall excellent with respect to LV volumetric indices, best for the experienced observer (intraclass correlation coefficient (ICC) > 0.98, coefficient of variation (CoV, < 9.6%) closely followed by automated analyses (ICC > 0.93, CoV < 12.4%) and lowest for the inexperienced observer (ICC > 0.86, CoV < 18.8%). Inter-study reproducibility of RV volumes was excellent for the experienced observer (ICC > 0.88, CoV < 10.7%) but considerably lower for automated and inexperienced manual analyses (ICC > 0.69 and > 0.46, CoV < 22.8% and < 28.7% respectively). In this cohort, fully automated analyses allowed reliable serial investigations of LV volumes with comparable inter-study reproducibility to manual analyses performed by an experienced CMR observer. In contrast, RV automated quantification with current algorithms still relied on manual post-processing for reliability.
3D sub-nanometer analysis of glucose in an aqueous solution by cryo-atom probe tomography
Authors: Schwarz T. M. , Dietrich C. A. , Ott J. , Weikum E. M. , Lawitzki R. , Solodenko H. , Hadjixenophontos E. , Gault B. , Kästner J. , Schmitz G. , Stender P.
Published: June 2021

Atom Probe Tomography (APT) is currently a well-established technique to analyse the composition of solid materials including metals, semiconductors and ceramics with up to near-atomic resolution. Using an aqueous glucose solution, we now extended the technique to frozen solutions. While the mass signals of the common glucose fragments CxHyand CxOyHzoverlap with (H2O)nH from water, we achieved stoichiometrically correct values via signal deconvolution. Density functional theory (DFT) calculations were performed to investigate the stability of the detected pyranose fragments. This paper demonstrates APT’s capabilities to achieve sub-nanometre resolution in tracing whole glucose molecules in a frozen solution by using cryogenic workflows. We use a solution of defined concentration to investigate the chemical resolution capabilities as a step toward the measurement of biological molecules. Due to the evaporation of nearly intact glucose molecules, their position within the measured 3D volume of the solution can be determined with sub-nanometre resolution. Our analyses take analytical techniques to a new level, since chemical characterization methods for cryogenically-frozen solutions or biological materials are limited.
Evident hypopigmentation without other ocular deficits in Dutch patients with oculocutaneous albinism type 4
Authors: Kruijt C. C. , Schalij-Delfos N. E. , de Wit G. C. , Florijn R. J. , van Genderen M. M.
Published: June 2021

To describe the phenotype of Dutch patients with oculocutaneous albinism type 4 (OCA4), we collected data on pigmentation (skin, hair, and eyes), visual acuity (VA), nystagmus, foveal hypoplasia, chiasmal misrouting, and molecular analyses of nine Dutch OCA4 patients from the Bartiméus Diagnostic Center for complex visual disorders. All patients had severely reduced pigmentation of skin, hair, and eyes with iris transillumination over 360 degrees. Three unrelated OCA4 patients had normal VA, no nystagmus, no foveal hypoplasia, and no misrouting of the visual pathways. Six patients had poor visual acuity (0.6 to 1.0 logMAR), nystagmus, severe foveal hypoplasia and misrouting. We found two novel variants in the SLC45A2 gene, c.310C > T; (p.Pro104Ser), and c.1368 + 3_1368 + 9del; (p.?). OCA4 patients of this Dutch cohort all had hypopigmentation of skin, hair, and iris translucency. However, patients were either severely affected with regard to visual acuity, foveal hypoplasia, and misrouting, or visually not affected at all. We describe for the first time OCA4 patients with an evident lack of pigmentation, but normal visual acuity, normal foveal development and absence of misrouting. This implies that absence of melanin does not invariably lead to foveal hypoplasia and abnormal routing of the visual pathways.
Efficiency of a pilot scheme for the separate collection of the biowaste from municipal solid waste in Spain
Authors: Gallardo Antonio , Colomer-Mendoza Francisco J. , Carlos-Alberola Mar , Badenes Cristóbal , Edo-Alcón Natalia , Esteban-Altabella Joan
Published: June 2021

According to EU regulations, member states shall take measures to encourage the recycling of biowaste in a way that fulfils a high level of environmental protection. In Spain, the separate collection of biowaste is only implemented in some regions. For this reason, a pilot scheme based on an information campaign and the location of a specific brown container for biowaste in specific zones of the city was carried out in Castelló de la Plana (Spain) over a period of six months. In this period, the collection and composition of the biowaste was monitored in depth with the goal of determining the evolution of the efficiency of the new collection system over time. In the zones, the quality rate in the biowaste container increased as the pilot study progressed, finally reaching 90%. The rate of biowaste separation also increased in the three zones over time, although in different ways, which means that there is greater collaboration on the part of citizens. On the other hand, an analysis of the rate of net biowaste daily collection from zones 2 and 3 has shown that their value increases as the rate of containerization of biowaste decreases. Therefore, to obtain better results it will be necessary to increase the containerization of biowaste, that is, to reduce the distance from the citizen to the container. It can thus be said that there is a positive evolution of the experience, which boosts confidence when it comes to implementing the system throughout the city.
Combined nano and micro structuring for enhanced radiative cooling and efficiency of photovoltaic cells
Authors: Perrakis George , Tasolamprou Anna C. , Kenanakis George , Economou Eleftherios N. , Tzortzakis Stelios , Kafesaki Maria
Published: June 2021

Outdoor devices comprising materials with mid-IR emissions at the atmospheric window (8–13 μm) achieve passive heat dissipation to outer space (~ − 270 °C), besides the atmosphere, being suitable for cooling applications. Recent studies have shown that the micro-scale photonic patterning of such materials further enhances their spectral emissivity. This approach is crucial, especially for daytime operation, where solar radiation often increases the device heat load. However, micro-scale patterning is often sub-optimal for other wavelengths besides 8–13 μm, limiting the devices’ efficiency. Here, we show that the superposition of properly designed in-plane nano- and micro-scaled periodic patterns results in enhanced device performance in the case of solar cell applications. We apply this idea in scalable, few-micron-thick, and simple single-material (glass) radiative coolers on top of simple-planar Si substrates, where we show an ~ 25.4% solar absorption enhancement, combined with a ~  ≤ 5.8 °C temperature reduction. Utilizing a coupled opto-electro-thermal modeling we evaluate our nano-micro-scale cooler also in the case of selected, highly-efficient Si-based photovoltaic architectures, where we achieve an efficiency enhancement of ~ 3.1%, which is 2.3 times higher compared to common anti-reflection layers, while the operating temperature of the device also decreases. Besides the enhanced performance of our nano-micro-scale cooler, our approach of superimposing double- or multi-periodic gratings is generic and suitable in all cases where the performance of a device depends on its response on more than one frequency bands.
The interaction of ethnicity and deprivation on COVID-19 mortality risk: a retrospective ecological study
Authors: Chaudhuri Kausik , Chakrabarti Anindita , Lima Jose Martin , Chandan Joht Singh , Bandyopadhyay Siddhartha
Published: June 2021

Black, Asian and Minority Ethnic (BAME) populations are at an increased risk of developing COVID-19 and consequentially more severe outcomes compared to White populations. The aim of this study was to quantify how much of the disproportionate disease burden can be attributed to ethnicity and deprivation as well as its interaction. An ecological study was conducted using data derived from the Office for National Statistics data at a Local Authority District (LAD) level in England between 1st March and 17th April 2020. The primary analysis examined how age adjusted COVID-19 mortality depends on ethnicity, deprivation, and the interaction between the two using linear regression. The secondary analysis using spatial regression methods allowed for the quantification of the extent of LAD spillover effect of COVID-19 mortality. We find that in LADs with the highest deprivation quartile, where there is a 1 percentage point increase in “Black-African (regression coefficient 2.86; 95% CI 1.08–4.64)”, “Black-Caribbean (9.66: 95% CI 5.25–14.06)” and “Bangladeshi (1.95: 95% CI 1.14–2.76)” communities, there is a significantly higher age-adjusted COVID-19 mortality compared to respective control populations. In addition, the spatial regression results indicated positive significant correlation between the age-adjusted mortality in one LAD and the age-adjusted mortality in a neighbouring LAD, suggesting a spillover effect. Our results suggest targeted public health measures to support those who are deprived and belong to BAME communities as well as to encourage restricted movement between different localities to limit disease propagation.
Picochlorum celeri as a model system for robust outdoor algal growth in seawater
Authors: Krishnan Anagha , Likhogrud Maria , Cano Melissa , Edmundson Scott , Melanson Jenna B. , Huesemann Michael , McGowen John , Weissman Joseph C. , Posewitz Matthew C.
Published: June 2021

With fast growth rates, broad halotolerance and the ability to thrive at high temperatures, algae in the genus Picochlorum are emerging as promising biomass producers. Recently, we isolated a remarkably productive strain, Picochlorum celeri, that attains > 40 g m−2 day−1 productivities using simulated outdoor light. To test outdoor productivities, Picochlorum celeri was cultivated in 820 L raceway ponds at the Arizona Center for Algae Technology and Innovation. Picochlorum celeri demonstrated the highest outdoor biomass productivities reported to date at this testbed averaging ~ 31 g m−2 day−1 over four months with a monthly (August) high of ~ 36 g m−2 day−1. Several single day productivities were > 40 g m−2 day−1. Importantly for sustainability, Picochlorum celeri achieved these productivities in saline water ranging from seawater to 50 parts per thousand sea salts, without any biocides or pond crashes, for over 143 days. Lastly, we report robust genetic engineering tools for future strain improvements.
Clinical significance of small molecule metabolites in the blood of patients with different types of liver injury
Authors: Li Hui , Wang Yan , Ma Shizhao , Zhang Chaoqun , Liu Hua , Sun Dianxing
Published: June 2021

To understand the characteristic of changes of serum metabolites between healthy people and patients with hepatitis B virus (HBV) infection at different stages of disease, and to provide reference metabolomics information for clinical diagnosis of liver disease patients. 255 patients with different stages of HBV infection were selected. 3 mL blood was collected from each patient in the morning to detect differences in serum lysophosphatidylcholine, acetyl-l-carnitine, oleic acid amide, and glycocholic acid concentrations by UFLC-IT-TOF/MS. The diagnostic values of four metabolic substances were evaluated by receiver operating characteristic (ROC) curve. The results showed that the optimal cut-off value of oleic acid amide concentration of the liver cirrhosis and HCC groups was 23.6 mg/L, with a diagnostic sensitivity of 88.9% and specificity of 70.6%. The diagnostic efficacies of the three substances were similar in the hepatitis and HCC groups, with an optimal cut-off value of 2.04 mg/L, and a diagnostic sensitivity and specificity of 100% and 47.2%, respectively. The optimal cut-off value of lecithin of the HBV-carrier and HCC groups was 132.85 mg/L, with a diagnostic sensitivity and specificity of 88.9% and 66.7%, respectively. The optimal cut-off value of oleic acid amide of the healthy and HCC groups was 129.03 mg/L, with a diagnostic sensitivity and specificity of 88.4% and 83.3%, respectively. Lysophosphatidylcholine, acetyl-l-carnitine, and oleic acid amide were potential metabolic markers of HCC. Among them, lysophosphatidylcholine was low in the blood of HCC patients, and its diagnostic efficacy was better than that of acetyl-l-carnitine and oleic acid amide, providing reference metabolomics information in clinical diagnosis and future research.
The difference in the CO2adsorption capacities of different functionalized pillar-layered metal–organic frameworks (MOFs)
Authors: Gao Xiang-Jing , Zheng He-Gen
Published: June 2021

A series of isostructural pillar-layered MOFs with different functional groups have different CO2adsorption capacities.
Scandium calix[n]arenes (n = 4, 6, 8): structural, cytotoxicity and ring opening polymerization studies
Authors: Alshamrani Abdullah Fahad A. , Santoro Orlando , Prior Timothy J. , Alamri Mohammed A. , Stasiuk Graeme J. , Elsegood Mark R. J. , Redshaw Carl
Published: June 2021

Unusual scandium calix[n]arenes (n = 4, 6, 8) have been isolated, structurally characterized and screened for their toxicity and ability to catalyze ring opening polymerizations (ROP) of cyclohexene oxide.
Redox-triggered reversible modulation of intense near-infrared and visible absorption using a paddlewheel-type diruthenium(iii) complex
Authors: Kataoka Yusuke , Imasaki Nanako , Yano Natsumi , Mitsumi Minoru , Handa Makoto
Published: June 2021

A dramatic reversible modulation of the intense near-infrared and visible absorption features of the paddlewheel-type Ru2 complex can be achieved.
Lactic acid bacteria strains relieve hyperuricaemia by suppressing xanthine oxidase activityviaa short-chain fatty acid-dependent mechanism
Authors: Ni Caixin , Li Xin , Wang Linlin , Li Xiu , Zhao Jianxin , Zhang Hao , Wang Gang , Chen Wei
Published: June 2021

L. rhamnosusR31,L. rhamnosusR28-1 andL. reuteriL20M3 relieved hyperuricaemia in mouse model by promoting SCFA production.
Gut microbiota mediates the effects of curcumin on enhancing Ucp1-dependent thermogenesis and improving high-fat diet-induced obesity
Authors: Han Zaiqi , Yao Lu , Zhong Yue , Xiao Yang , Gao Jing , Zheng Zhaozheng , Fan Sijia , Zhang Ziheng , Gong Shanggang , Chang Sheng , Cui Xiaona , Cai Jianhui
Published: June 2021

Curcumin enhances Ucp1-dependent thermogenesis to ameliorate high-fat diet-induced obesity through modulation of gut microbiota and bile acid metabolism.
A three-component iodine-catalyzed oxidative coupling reaction: a heterodifunctionalization of 3-methylindoles
Authors: Zhang Wei , Xiang Shiqun , Fan Weibin , Jin Jiang , Li Yinghua , Huang Deguang
Published: June 2021

A novel method is reported for the heterodifunctionalization of 3-methylindoles in a TBHP/KI catalytic system with tert-butyl peroxy bonding to the indole skeleton as a functional group.
Phase-transfer catalysed asymmetric synthesis of α-chiral tetrasubstituted α-aminothioesters
Authors: Yoshida Yasushi , Kasuya Reina , Mino Takashi , Sakamoto Masami
Published: June 2021

α-Tetrasubstituted-α-amino thioesters were synthesised through chiral phase-transfer catalysed Michael reaction of imino thioesters in up to 97% yield with up to 81% ee.
Visible-light-mediated phosphonylation reaction: formation of phosphonates from alkyl/arylhydrazines and trialkylphosphites using zinc phthalocyanine
Authors: Koohgard Mehdi , Hosseini-Sarvari Mona
Published: June 2021

A set of zinc phthalocyanine-catalyzed phosphonylations of alkyl/arylhydrazines with trialkylphosphites under visible light was developed. The reactions proceeded in the presence of atmospheric oxygen without using any additional ligand and/or base.
N-Triflination of pyrazolones: a new method for N–S bond formation
Authors: Panigrahi Ahwan , Muniraj Nachimuthu , Prabhu Kandikere Ramaiah
Published: June 2021

A simple method, which takes place quickly in 5 min, is developed for the N-triflination of pyrazolones using CF3SO2Na (Langlois reagent) and phenyliodine(iii)bis(trifluoroacetate) (PIFA).
A promiscuous glycosyltransferase generates poly-β-1,4-glucan derivatives that facilitate mass spectrometry-based detection of cellulolytic enzymes
Authors: Bulmer Gregory S. , Mattey Ashley P. , Parmeggiani Fabio , Williams Ryan , Ledru Helene , Marchesi Andrea , Seibt Lisa S. , Both Peter , Huang Kun , Galan M. Carmen , Flitsch Sabine L. , Green Anthony P. , van Munster Jolanda M.
Published: June 2021

Promiscuous activity of a glycosyltransferase was exploited to polymerise glucose from UDP-glucose via the generation of β-1,4-glycosidic linkages.
Dancing with oils – the interaction of lipases with different oil/water interfaces
Authors: Filipe Hugo A. L. , Almeida Maëva C. F. , Teixeira Rafaela R. , Esteves Margarida I. M. , Henriques César A. , Antunes Filipe E.
Published: June 2021

Detailed characterization of the interaction of lipases with different vegetal oils and food fats through molecular dynamics simulations.
Compact disks
Authors: Miotello A. , Rosotti G. , Ansdell M. , Facchini S. , Manara C. F. , Williams J. P. , Bruderer S.
Published: June 2021

Context. ALMA disk surveys have shown that a large fraction of observed protoplanetary disks in nearby star-forming regions (SFRs) are fainter than expected in CO isotopolog emission. Disks not detected in 13CO line emission are also faint and often unresolved in the continuum emission at an angular resolution of around 0.2 arcsec.

Aims. Focusing on the Lupus SFR, the aim of this work is to investigate whether this population comprises radially extended and low-mass disks – as commonly assumed so far – or intrinsically radially compact disks, an interpretation that we propose in this paper. The latter scenario was already proposed for individual sources or small samples of disks, while this work targets a large population of disks in a single young SFR for which statistical arguments can be made.

Methods. We ran a new grid of physical–chemical models of compact disks with the physical–chemical code DALI in order to cover a region of the parameter space that has not been explored before with this code. We compared these models with 12CO and 13CO ALMA observations of faint disks in the Lupus SFR, and report the simulated integrated continuum and CO isotopolog fluxes of the new grid of compact models.

Results. Lupus disks that are not detected in 13CO emission and have faint or undetected 12CO emission are consistent with compact disk models. For disks with a limited radial extent, the emission of CO isotopologs is mostly optically thick and scales with the surface area, that is, it is fainter for smaller objects. The fraction of compact disks is potentially between roughly 50% and 60% of the entire Lupus sample. Deeper observations of 12CO and 13CO at a moderate angular resolution will allow us to distinguish whether faint disks are intrinsically compact or extended but faint, without the need to resolve them. If the fainter end of the disk population observed by ALMA disk surveys is consistent with such objects being very compact, this will either create a tension with viscous spreading or require MHD winds or external processes to truncate the disks.
Numerical simulation of stress distribution
Authors: Barykina Olga , Fomenko Igor , Zerkal Oleg
Published: June 2021

The Rogun hydropower plant is being constructed in Tajikistan, in the valley of the Vakhsh River. The construction site is located in a narrow gorge separating the Vakhsh and Surkh-Ku ridges. Most of the hydroelectric complex structures are located within a single tectonic block, which is bounded by two faults - Ionakhsh and Gulizindan, which are proximal to the Vakhsh regional fault. The study of stress distribution around the diversion tunnel was carried out by numerical simulation, which aimed to identify the stress distribution in the strongly dislocated heterogeneous rock massif before and after the tunnel creation. The underground cavity of the tunnel is a significant factor influencing the natural stress field of the rock massif. An area with critical values of the strength coefficient in the working roof, caused by the presence of a weak layer of Lower Cretaceous siltstones, is revealed in the tunnel location. The size of this area reaches two tunnel diameters. The change of stresses and their concentration around the underground working can cause deformations in the roof (collapse or rock bumps).
Methods for adaptive control of objects with variable parameters
Authors: Yakubov Maksadkhan , Jamalova Gulchekhra
Published: June 2021

The work uses the method of standard characteristic polynomials, based on the Lyapunov theorem on adaptive control systems, the theory of flexible and robust control, methods of the theory of nonlinear systems. When modeling an internal combustion engine, methods of identification theory were additionally involved. When obtaining theoretical results, the method of Lyapunov functions, the method of standard characteristic polynomials, methods of the theory of adaptive and robust control, methods of the theory of nonlinear systems were used. When constructing a model of an internal combustion engine, methods of identification theory were additionally involved.

For the synthesis of control systems in conditions of uncertainty, one of the topical directions is adaptive systems. These are control systems that compensate for parametric, signal, functional, or structural uncertainties of the control object by automatically adjusting the controller during the system's working operation, i.e., adaptive systems make up for the lack of a priori information about the control object during operational operation. To solve the problem of managing undefined objects, for example, classical methods are used. In such methods, when state variables are immeasurable, it becomes necessary to use additional dynamic filters. Classical methods are more often used for a limited class of objects. In the case of class extension, the structure of the control algorithm becomes more complicated.
Technique for experimental studies of asphalt concrete milling process
Authors: Pirnaev Sharofiddin , Sindarov Rakhmat , Dzhumabeva Fotima , Saidova Shoira
Published: June 2021

The paper considers the issues of destruction of the working bodies of road-building equipment operated under conditions of abrasive wear with a fixed abrasive. Analytical studies of the influence of the tribological parameters of cutters on the intensity of their wear have been carried out. Based on the solution of the equations of the dynamics of the movement of the cutter in a viscoelastic medium, its geometric shape is optimized. The mathematical dependences of the influence of the geometric dimensions of the cutter on the pressure value and the intensity of tool wear are obtained.
The machines optimal set development for the construction of automotive roads elements based on the "Norm" for machines employment cost
Authors: Maksudov Zokir , Kudaybergenov Mavlyan , Kabikenov Sh , Sungatollakyzy Aydana
Published: June 2021

Currently, increasing the efficiency of using the fleet of cars and the functioning of a road enterprise for the construction of highways by forming an optimal set of machines based on the developed normative labor intensity and the production of road construction vehicles for the construction of elements of highways, in a mixed fleet of vehicles of a road enterprise, is a very relevant task. A technique has been developed for optimizing a set of machines for the construction of road elements based on the "norm" of the labor input of the machines. Methodology for standardizing the production of road equipment and calculating the optimal set of vehicles based on the production rate of vehicles for the construction of road elements has been developed. A system of machines has been developed to form a set of machines to construct road elements. Nomograms have been developed for determining and forming the optimal set of machines for the construction of road elements based on the "norm" of the labor input of machines.
Modelling traffic flow emissions at signalized intersection with PTV vissim
Authors: Kutlimuratov Kudrat , Khakimov Shaukat , Mukhitdinov Akmal , Samatov Rustam
Published: June 2021

The effect of roadway intersection design is strictly linked to a reduction in traffic congestion, fuel consumption and emissions in an urban area. This paper presents a comparative result of the typical four-legged intersection and roundabout operational performance for effective management. Accordingly, a computer model for estimation traffic emissions for two kinds of intersections is created. This study presents a detailed analysis and modelling traffic flow emissions using PTV vissim software and methodology with reasonable solutions to plan a road intersection.
Infrastructure mapping and performance assessment of irrigation system using GIS and remote sensing
Authors: Narziev Jasurbek , Nikam Bhaskar , Gapparov Furqat
Published: June 2021

Hence evaluating and improving the performance of irrigation systems is of paramount importance in Irrigation Water Management. Researchers are making many attempts to evaluate and benchmark the performance of irrigation systems. All of them have concluded that the non-availability of a detailed database limits their efforts. Keeping this in mind, an attempt is made in this pilot project titled “Infrastructure mapping and Performance Assessment of Irrigation system using GIS and Remote Sensing.” The results indicate that the Irrigation system's performance is satisfactory, but the water supply is not adequate if surface water (canal water) is the only source of irrigation. The analysis of feedback collected from farmers indicates that the positive project impacts agricultural productivity and socio-economics in the command area.
Numerical substantiation of the parameters of the air-hydraulic hood by a diaphragm
Authors: Bazarov Orifjon , Jonkobilov Ulugmurad , Jonkobilov Sobir , Rajabov Ulugbek , Xoshiyev Shukhrat
Published: June 2021

The article is about calculating the main parameters of air - hydraulic hoods with a diaphragm to reduce the emergency consequences of a water hammer, possible in the pressure pipelines of an irrigation pumping station. Based on the results of numerical studies by the method of finite differences of the proposed hydraulic shock absorber, dependencies were obtained based on a certain air in the absorbers, the total capacity of the cylindrical cap was determined to determine the main dimensions of the absorbers. Based on the results of numerical studies by the method of finite differences of the proposed hydraulic shock absorber, dependencies were obtained based on a certain air in the absorbers, the total capacity of the cylindrical cap was determined to determine the main dimensions of the absorbers. To determine the economic dimensions of the proposed cap design, comparative calculations of numerical experiments with experimental data prove the reliability of the proposed dependencies using the finite difference method.
Conditions of soils dilution of dams under seismic impacts
Authors: Rasulov Khayat
Published: June 2021

This report presents the results of the author's research on the dilution of water-saturated cohesive soils in the conditions of concussions. The nature of the weakening of the soil connectivity during vibration and the dynamic pressure that occurs in the thickness during the compaction of the disturbed soil structures, which contribute to the liquefaction and spreading of the soil from the body of the structure, is described. The criterion of the possibility of violation of the soil structure in the conditions of concussions is given. A theoretical method for determining this important indicator of the seismic strength of the soil is given.
Universal contactless converters of monitoring and control systems in water power industry
Authors: Plakhtiev Anatoliy , Gaziev Gayratjon , Meliboev Yaxyojon , Doniyorov Odil , Norholboyev Davron , Ibragimov Jasur
Published: June 2021

The paper substantiates the need to use non-contact conversion and measurement of large direct currents using non-destructive magneto modulation non-contact ferromagnetic transducers of increased sensitivity for the needs of land reclamation, irrigation, industry, metallurgy and, in general, agriculture and water management; the results of their design development are presented. It is shown that the developed converter, in contrast to the known ones, has increased accuracy and sensitivity, a technologically advanced design and small weight and dimensions with low material consumption and cost. The issues of reliability of magnetic modulation contactless converters are considered. The results of their research have been obtained. It is shown that the reliability of wide-range magneto modulation contactless converters of large direct currents is equal to 0.998 and taking into account catastrophic failures, their total reliability is 0.9969. The developed converter can be widely used in electrical systems in land reclamation and irrigation, in water supply, industry, railway transport, science, technology and for checking electrical meters at their installation site.
Construction of vertical drainage wells using corrosion resistant materials
Authors: Akhmedov Ikromali , Mirkhasilova Zulfiya
Published: June 2021

Vertical drainage wells in terms of construction technology and design do not differ from wells for irrigation. They are not deeper in-depth than irrigation wells and are generally 40-70 m. The main task of vertical drainage wells is land reclamation. They, depending on natural and economic conditions, serve on 5-120 hectares of area. In many areas, vertical drainage wells serve a dual purpose; land reclamation and irrigation of agricultural crops. Water intake wells, including vertical drainage wells, are characterized by a decrease in their flow rates during operation. To ensure the stable operation of the irrigation and drainage system, where water intake wells are operated, repair and restoration work is carried out on them, aimed at increasing flow rates. For the construction of vertical drainage wells in the Sirdarya river basin, steel pipes and filters are mainly used, which corrode in an aggressive environment. In the water intake zone of the well and the metal corrosion process, the colmatation process also occurs. All of them are the main reasons for the decline in well production rates. The carried out repair and restoration measures are aimed at destroying the structure of corrosion and clogging products. In practice, mechanical, physical, biological, and chemical methods are used to clean the filters of water intake wells. They all have their own technology and equipment. However, all these works do not exclude the repeatability of the process. Repetitive workover will come to ineffective, the stage of good concertation is approaching. It is known that polymeric materials do not corrode. They work steadily in aggressive environments. To prevent the corrosion process, polymeric-seam pipes were used as a filter frame and a casing for the construction of vertical drainage wells. Two pilot wells were built on the territory of the Chiyili district of the Kyzylorda region of the Republic of Kazakhstan. The wells were drilled with a rotary drilling unit with backwash. Pure water (irrigation) was used as drilling fluid. To form a gravel pack in the annular zone of the casing, gravel-sand material from the Jailma quarry was used. The material was brought by rail and road transport. Pipe sections were prepared on the surface of 10 meters. Steel rings were put on the pipe from both ends of each section; their connection in the barrel was made by electric welding. The results showed that in the initial period of operation, a decline process was observed. In further exploitation, the well flow rate stabilized. As a result of construction using pipes and filters made of polymer material, the effect was achieved in terms of water volume more than 3 times and in terms of service life 4.2 times compared to a metal filter well.
Green Technologies for Management on Railroad Transportation
Authors: Efanov Dmitry , Osadchiy German , Plotnikov Dmitry , Banite Aushra , Norov Begmat , Ruziev Davron
Published: June 2021

Technique and technology development allows us to discuss the possibility of crucial changes into a conservative way of railroad transportation management. One of the options regarding the train control system is aimed at denial of the classic approach being connected with the implementation of a traditional automation kit. The authors of this article are being presented with the conception of a green IT railroad rolling stock control system called Green Interlocking. The above approach helps us rely on effective inexhaustible energy sources and modern know-how of data processing plus important technologies management.
Modeling of water and salt transfer in the initial period of plant development
Authors: Khojiyev Aliakbar , Muradov Rustam , Khojiyeva Shakhnoza , Yakubova Khurshida
Published: June 2021

Water - as moisture, has an essential role in all biochemical processes of plants; all vital processes occurring in a vegetative organism can proceed normally only under the condition of sufficient saturation of cages by moisture. Results of theoretical researches on dynamics of ground humidity have shown: (1) similarity of physical processes of change of humidity of soil on different irrigated areas (2) hysteresis of the nature of humidity at irrigation and drainage. (3) sharp recession of humidity of soil in the root zone.
Optimization of the power consumption mode of pumping stations of “Suv Okova” by reactive power
Authors: Muzafarov Shavkat , Isakov Abdusaid , Choriev Ruzimurat , Ismailova Zukhra , Mustafoyeva Durdona
Published: June 2021

The optimal modes of the existing compensating devices under operating conditions were determined. Minimum power and energy losses were taken as optimality criteria. The unconstrained optimization problem was considered, i.e., finding the absolute minimum. When solving the problem to find the optimal mode of operation of the “SUV OKOVA” network, a relative minimum was found since the system of constraints has a nonlinear form. The problem of conditional optimization in terms of reactive power is solved, for which the gradient method of quadratic programming is used.