bluuebunny/crossref_metadata_2025_split huggingface dataset:
Superparamagnetic core‐shell metal–organic framework Fe3O4@Ni‐MOF as efficient catalyst for oxidation of 1,4‐dihydropyridines using hydrogen peroxide
Authors: Janani Marzieh , Senejani Masumeh Abdoli , Isfahani Tahereh Momeni 
Published: July 2021

AbstractA facile and efficient method was described for oxidation of some 3,5‐diacyl or 3,5‐diester 1,4‐dihydropyridines using H2O2 in the presence of superparamagnetic core‐shell metal–organic framework Fe3O4@Ni‐MOF. The Fe3O4@Ni‐MOF has been obtained by Step‐by‐Step method in which magnetic Fe3O4 magnetic nanoparticles were coated with Ni‐MOF using a mercaptoacetic acid linker. The synthesized catalyst was characterized using thermogravimetric analysis, FT‐IR spectroscopy, powder X‐ray diffraction, field emission scanning electron microscopy and energy‐dispersive X‐ray analysis. The novel superparamagnetic core‐shell metal–organic framework Fe3O4@Ni‐MOF revealed high efficiency for oxidation of various 1,4‐dihydropyridines using hydrogen peroxide. The Box–Behnken design matrix and the response surface method were applied to investigate the optimization of the reaction conditions. The conditions for optimal reaction yield and time were: amount of catalyst ≈17 mmol, temperature ≈78°C and amount of hydrogen peroxide ≈ 1 ml. A variety of 3,5‐diacyl or 3,5‐diester 1,4‐dihydropyridines with different substituted functional groups have been converted to corresponding pyridines with good to excellent isolated yields using H2O2 and Fe3O4@Ni‐MOF. The catalyst was reused up to five times for the oxidation of 1,4‐dihydropyridines without a significant loss in catalytic activity. The short reaction times, simplicity of method, good to excellent yields and reusability of catalyst were some advantages of the proposed procedure.
Chitosan nanoparticles functionalized poly‐2‐hydroxyaniline supported CuO nanoparticles: An efficient heterogeneous and recyclable nanocatalyst for N‐arylation of amines with phenylboronic acid at ambient temperature
Authors: Seyedi Neda , Zahedifar Mahboobeh 
Published: July 2021

AbstractThe present study aims to prepare an effective and eco‐friendly nanocatalyst for the Chan–Lam coupling reaction of phenylboronic acid and amine in aerobic conditions. For this purpose, chitosan was extracted from shrimp shells waste by demineralization, deproteinization, and deacetylation processes and then converted to chitosan nanoparticles (CSN) by the ionic gelation with tripolyphosphate anions. Afterward, poly‐2‐hydroxyaniline (P2‐HA) was grafted to chitosan nanoparticles (NPs) to employ as the support for CuO NPs. Characterization of the nanocatalyst was done using Fourier transform infrared (FT‐IR), X‐ray powder diffraction (XRD), scanning electron microscopy (SEM), mapping, energy‐dispersive X‐ray spectroscopy (EDS), transmission electron microscopy (TEM), and thermogravimetric analysis (TGA). The CuO NPs were identified in the spherical shape with an average size of 17 nm. The prepared nanocatalyst exhibited excellent catalytic performance with a high turnover number (TON) and turnover frequency (TOF) for the Chan–Lam coupling reaction of phenyl boronic acid and amines with different electronic properties. The prepared catalyst could be readily recovered and reused for at least five runs without any noticeable change in structure and catalytic performance.Chitosan (CS) was prepared via demineralization, deproteinization, and deacetylation of shrimp shell and chitosan nanoparticles (CSN) were prepared via ionic gelation process. Polymerization of 2‐HA on the CSN surface was done to increase functional groups and create active sites for CuO NPs attachments. CuO NPs‐P2‐HA‐CSN nanocomposite has been shown high efficiently for the Chan–Lam coupling reaction.
Preparation of polysilsesquioxane reverse osmosis membranes for water desalination from tris[(ethoxysilyl)alkyl]amines by sol–gel process and interfacial polymerization
Authors: Zhang Dian , Kanezashi Masakoto , Tsuru Toshinori , Yamamoto Kazuki , Yakuwa Raku , Gunji Takahiro , Adachi Yohei , Ohshita Joji 
Published: July 2021

Organically bridged polysilsesquioxane (PSQ)‐based reverse osmosis (RO) membranes have been studied for water desalination. In this work, RO membranes were prepared from tris[3‐(triethoxysilyl)propyl]amine (TTESPA), tris[3‐(diethoxymethylsilyl)propyl]amine (TDEMSPA), tris[(triethoxysilyl)methyl]amine (TTESMA) tris[(triethoxysilyl)propenyl]amine (TTESP2A), and tris[3‐(triethoxysilyl)prop‐2‐ynyl]amine (TTESP3A) by the sol–gel process and interfacial polymerization. It was found that the TTESPA‐derived membranes gave the best RO performance among those prepared. The membrane prepared by the interfacial polymerization of TTESPA showed water permeance and salt rejection of 7.3 × 10−13 m3/m2sPa and 95.6% for 2000 ppm NaCl aqueous solution, respectively, which were higher than those previously reported for a membrane similarly prepared from bis[(triethoxysilyl)propyl]amine (1.4 × 10−13 m3/m2sPa and 93.6%).
Imidazole modified acrylate‐containing photocured hydrogels for the efficient removal of malachite green dye from aqueous solutions
Authors: Aracier Esra Duygu , Aydın Urucu Oya , Çakmakçi Emrah 
Published: July 2021

AbstractIn this work, we aimed to prepare a simple and an efficient adsorbent for the removal of toxic, cationic dye; malachite green (MG). We reviewed many previous studies and designed our adsorbent based on the rationale that (1) acidic groups containing monomers which are capable of making hydrogen bonds (or electrostatic interactions) with MG are very effective in adsorption and (2) π‐π stacking enhances the adsorption capacity. We first synthesized an imidazole‐acrylate adduct and used it for the preparation of photocured hydrogels. The imidazole‐acrylate adduct was characterized by H NMR and FTIR spectroscopy. The effect of experimental conditions on the MG adsorption properties of the hydrogels such as the effect of pH, time and MG concentration were also investigated. Under the optimum conditions (pH = 6 and 220 min contact time) at room temperature, the maximum adsorption capacity was found as high as 714.28 mg/g. The results showed that the adsorption process of the optimum hydrogel, which can be used 4 times without a significant loss in its adsorption capacity, fits the Langmuir isotherm model. The hydrogel adsorbent displayed good selectivity and reusability.
Variants on the UBE2L3/YDJC Autoimmune Disease Risk Haplotype Increase UBE2L3 Expression by Modulating CCCTC‐Binding Factor and YY1 Binding
Authors: Gopalakrishnan Jaanam , Tessneer Kandice L. , Fu Yao , Pasula Satish , Pelikan Richard C. , Kelly Jennifer A. , Wiley Graham B. , Gaffney Patrick M. 
Published: July 2021

ObjectiveGenetic variants spanning UBE2L3 are associated with increased expression of the UBE2L3‐encoded E2 ubiquitin‐conjugating enzyme H7 (UbcH7), which facilitates activation of proinflammatory NF‐κB signaling and susceptibility to autoimmune diseases. We undertook this study to delineate how genetic variants carried on the UBE2L3/YDJC autoimmune risk haplotype function to drive hypermorphic UBE2L3 expression.MethodsWe used bioinformatic analyses, electrophoretic mobility shift assays, and luciferase reporter assays to identify and functionally characterize allele‐specific effects of risk variants positioned in chromatin accessible regions of immune cells. Chromatin conformation capture with quantitative polymerase chain reaction (3C‐qPCR), chromatin immunoprecipitation (ChIP)–qPCR, and small interfering RNA (siRNA) knockdown assays were performed on patient‐derived Epstein‐Barr virus–transformed B cells homozygous for the UBE2L3/YDJC nonrisk or risk haplotype to determine if the risk haplotype increases UBE2L3 expression by altering the regulatory chromatin architecture in the region.ResultsOf the 7 prioritized variants, 5 demonstrated allele‐specific increases in nuclear protein binding affinity and regulatory activity. High‐throughput sequencing of chromosome conformation capture coupled with ChIP (HiChIP) and 3C‐qPCR uncovered a long‐range interaction between the UBE2L3 promoter (rs140490, rs140491, rs11089620) and the downstream YDJC promoter (rs3747093) that was strengthened in the presence of the UBE2L3/YDJC risk haplotype, and correlated with the loss of CCCTC‐binding factor (CTCF) and gain of YY1 binding at the risk alleles. Depleting YY1 by siRNA disrupted the long‐range interaction between the 2 promoters and reduced UBE2L3 expression.ConclusionThe UBE2L3/YDJC autoimmune risk haplotype increases UBE2L3 expression through strengthening a YY1‐mediated interaction between the UBE2L3 and YDJC promoters.
Molybdenum/Tungsten‐Based Heteropoly Salts in Oxidations
Authors: Chen Wenchao , Tan Choon‐Hong , Wang Hong , Ye Xinyi 
Published: July 2021

AbstractOxidation represents one of the most important and practical chemical transformations for both organic synthesis, material science and pharmaceutical area. Among the existing strategies, molybdenum/tungsten‐based heteropoly salts involved oxidations with low‐cost and environmentally benign terminal oxidant and thus have attracted considerable attention in recent years. In this review, we have summarized the recent development of heteropoly salts utilized in oxidations, mainly the peroxomolybdates and peroxotungstates. We wish to highlight the progress made in the past 20 years of this field. Three categories are classified according to the aggregation state of metal oxides. Special attention is paid to the catalytically active peroxometalate species generated during the oxidation process. It is helpful to shed light on the common features that enable highly efficient and selective oxidations. We aim to inspire fellow chemists to explore more functional metalates for catalytic oxidations, especially asymmetric versions. Meanwhile, we attempt to understand the design principles for the discovery of more efficient, selective and economical catalytic systems.
Aptasensing luteinizing hormone to determine gynecological endocrine complications on graphene oxide layered sensor
Authors: Sun Huanhuan , Bao Xiucui , Yao Xiaoling , Gopinath Subash C. B. , Min Yifei 
Published: July 2021

AbstractLuteinizing hormone (LH)/lutropin is an interstitial cell‐stimulating hormone playing a predominant role in the reproductive system, and highly correlated with the infertility treatment in both men and women. This research was concentrated to quantify LH level by using interdigitated electrode sensor. To improve the electric current flow, sensing electrode was modified with graphene oxide (GO) and the aptamer probe was attached on GO through biotin‐streptavidin linker. Current responses were measured with aptamer–LH interaction at the target concentrations between 7.5 nM and 1 μM and the detection limit of LH was calculated as 60 nM with the determination coefficient (R2) value, 0.9229 [y = 1.296x − 2.8435] on a linear range from 30 nM to 1 μM. Further, biofouling effect on sensing electrode surface was analyzed with complementary aptamer sequence, control proteins (albumin and globulin). The above GO‐aptamer‐modified interdigitated electrode sensor helps to quantify LH level and diagnose gynecological endocrinology‐related complications.
A tailored LNA clamping design principle: Efficient, economized, specific and ultrasensitive for the detection of point mutations
Authors: Yang Hao , Yan Mengqiu , Xu Gaolian , Qian Xiaohua , Zhao Ruiying , Han Yuchen , Zhang Lin , Gu Hongchen , Xu Hong 
Published: July 2021

AbstractIn the development of personalized medicine, the ultrasensitive detection of point mutations that correlate with diseases is important to improve the efficacy of treatment and guide clinical medication. In this study, locked nucleic acid (LNA) was introduced as an amplification suppressor of a massive number of wild‐type alleles in an amplification refractory mutation system (ARMS) to achieve the detection of low‐abundance mutations with high specificity and sensitivity of at least 0.1%. By integrating the length of clamp, base type, number and position of LNA modifications, we have established a “shortest length with the fewest LNA bases” principle from which each LNA base would play a key role in the affinity and the ability of single base discrimination could be improve. Finally, based on this LNA design guideline, a series of the most important single point mutation sites of epidermal growth factor receptor (EGFR) was verified to achieve the optimal amplification state which as low as 0.1% mutation gene amplification was not affected under the wild gene amplification was completely inhibited, demonstrating that the proposed design principle has good applicability and versatility and is of great significance for the detection of circulating tumor DNA.
Tracking metabolic responses based on macronutrient consumption: A comprehensive study to continuously monitor and quantify dual markers (cortisol and glucose) in human sweat using WATCH sensor
Authors: Pali Madhavi , Jagannath Badrinath , Lin Kai‐Chun , Sankhala Devangsingh , Upasham Sayali , Muthukumar Sriram , Prasad Shalini 
Published: July 2021

AbstractWearable Awareness Through Continuous Hidrosis (WATCH) sensor is a sweat based monitoring platform that tracks cortisol and glucose for the purpose of understanding metabolic responses related to macronutrient consumption. In this research article, we have demonstrated the ability of tracking these two biomarkers in passive human sweat over a workday period (8 h) for 10 human subjects in conjunction with their macronutrient consumption. The validation of the WATCH sensor performance was carried out via standard reference methods such as Luminex and ELISA This is a first demonstration of a passive sweat sensing technology that can detect interrelated dual metabolites, cortisol, and glucose, on a single sensing platform. The significance of detecting the two biomarkers simultaneously is that capturing the body's metabolic and endocrinal responses to dietary triggers can lead to improved lifestyle management. For sweat cortisol, we achieved a detection limit of 1 ng/ml (range ∼1–12.5 ng/ml) with Pearson's “r” of 0.897 in reference studies and 0.868 in WATCH studies. Similarly, for sweat glucose, we achieved a detection limit of 1 mg/dl (range ∼ 1–11 mg/dl) with Pearson's “r” of 0.968 in reference studies and 0.947 in WATCH studies, respectively. The statistical robustness of the WATCH sensor was established through the Bland–Altman analysis, whereby the sweat cortisol and sweat glucose levels are comparable to the standard reference method. The probability distribution (t‐test), power analysis (power 0.82–0.87), α = 0.05. Mean absolute relative difference (MARD) outcome of ˷5.10–5.15% further confirmed the statistical robustness of the sweat sensing WATCH device output.
Comparisons of β‐Hairpin Propensity Among Peptides with Homochiral or Heterochiral Strands
Authors: Liu Xinyu , Gellman Samuel H. 
Published: July 2021

AbstractAssemblies of racemic β‐sheet‐forming peptides have attracted attention for biomedical applications because racemic forms of peptides can self‐associate more avidly than do single enantiomers. In 1953, Pauling and Corey proposed “rippled β‐sheet” modes of H‐bond‐mediated interstrand assembly for alternating L‐ and D‐peptide strands; this structural hypothesis was complementary to their proposal of “pleated β‐sheet” assembly for L‐peptides. Although no high‐resolution structure has been reported for a rippled β‐sheet, there is strong evidence for the occurrence of rippled β‐sheets in some racemic peptide assemblies. Here we compare propensities of peptide diastereomers in aqueous solution to form a minimum increment of β‐sheet in which two antiparallel strands associate. β‐Hairpin folding is observed for homochiral peptides with aligned nonpolar side chains, but no β‐hairpin population can be detected for diastereomers in which one strand contains L residues and the other contains D residues. These observations suggest that rippled β‐sheet assemblies are stabilized by interactions between β‐sheet layers rather than interactions within these layers.
Dental implant displacement complicated by epulis fissuratum and extraoral fistula in a patient with senile dementia of Alzheimer's type
Authors: Chybicki Damian , Słowik Mateusz , Torbicka Gaja , Białkowska‐Głowacka Jolanta , Janas‐Naze Anna 
Published: July 2021

AbstractDental treatment of patients suffering from mental illnesses should not be neglected as good condition of oral cavity is one of the factors that determine satisfactory quality of life, not only by aesthetic but also by functional considerations.
Leiomyoma originating from left round ligament presents as symptomatic inguinal hernia
Authors: Kypriotis Konstantinos , Kathopoulis Nikolaos , Tsiriva Maria , Zacharakis Dimitrios , Chatzipapas Ioannis , Protopapas Athanasios 
Published: July 2021

AbstractLeiomyomas may develop at extra‐uterine locations and pose diagnostic dile mmas. This is a case of a fibroma originating from the left round ligament presenting as a symptomatic inguinal hernia.
Finding Adapted Quinones for Harvesting Electrons from Photosynthetic Algae Suspensions
Authors: Sayegh Adnan , Perego Luca A. , Arderiu Romero Marc , Escudero Louis , Delacotte Jérôme , Guille‐Collignon Manon , Grimaud Laurence , Bailleul Benjamin , Lemaître Frédéric 
Published: July 2021

AbstractAmong all the chemical and biotechnological strategies implemented to extract energy from oxygenic photosynthesis, several concern the use of intact photosynthetic organisms (algae, cyanobacteria…). This means rerouting (fully or partially) the electron flow from the photosynthetic chain to an outer collecting electrode thus generating a photocurrent. While diverting photosynthetic electrons from living biological systems is an encouraging approach, this strategy is limited by the need to use an electron shuttle. Redox mediators that are able to interact with an embedded photosynthetic chain are rather scarce. In this respect, exogenous quinones are the most frequently used. Unfortunately, some of them also act as poisoning agents within relatively long timeframes. It thus raises the question of the best quinone. In this work, we use a previously reported electrochemical device to analyze the performance of different quinones. Photocurrents (maximum photocurrent, stability) were measured from suspensions of Chlamydomonas reinhardtii algae/quinones by chronoamperometry and compared to parameters like quinone redox potentials or cytotoxic concentration. From these results, several quinones were synthesized and analyzed in order to find the best compromise between bioelectricity production and toxicity.
Effect of Ectoine on the Conformation and Hybridization of dsDNA in Monolayer Films: A Spectroelectrochemical Study
Authors: Wittmar Julia , Ohle Corina , Kunte Jörg , Brand Izabella 
Published: July 2021

AbstractLack of long‐time stability of dsDNA‐based supramolecular assemblies is an important issue that hinders their applications. In this work, 20 base pairs long dsDNA fragments [(dCdG)20‐65 %] composed of 65 % dCdG and 35 % dAdT nucleotides were tethered via a thiol to the surface of a gold electrode. The self‐assembled (dCdG)20‐65 % monolayer was immersed in solutions containing ectoine, a compatible solute. Electrochemical results showed that these monolayers were stable for one month. In situ IR spectroscopy indicated that ectoine interacts weakly with the phosphate‐ribose backbone, dehydrating the phosphate groups and stabilizing the A‐DNA conformation. This structural reorganization led to a reorientation of nucleic acid base pairs and a local disruption of the double‐helix structure. However, the conformation and orientation of the dsDNA fragment was stable in the −0.4<E<0.3 potential range. As a direct interaction between ectoine and dsDNA, the enzymatic reaction of exonuclease VII hydrolyzing the ester phosphate bond in ssDNA, was blocked. We show that the addition of a compatible solute to the electrolyte solution stabilized the dsDNA structure despite structural rearrangements.
Photoelectrochemical Reduction of Carbon Dioxide with a Copper Graphitic Carbon Nitride Photocathode
Authors: Yu Huijun , Cohen Hagai , Neumann Ronny 
Published: July 2021

AbstractResearch on the photoreduction of CO2 often has been dominated by the use of sacrificial reducing agents. A pathway that avoids this problem would be the development of photocathodes for CO2 reduction that could then be coupled to a photoanodic oxygen evolution reaction. Here, we present the use of copper‐substituted graphitic carbon nitride (Cu−CN) on a fluorinated tin oxide (FTO) electrode for the photoelectrochemical two‐electron reduction of CO2 to CO as a major product (>95 %) and formic acid (<5 %). The results show that at a potential of −2.5 V versus Fc\Fc+ the CO2 reduction activity of Cu−CN on FTO electrode improves by 25 % upon illumination by visible light with a faradaic efficiency of nearly 100 %. Independently, X‐ray photoelectron spectroscopy conclusively shows a pronounced increase in the electrical conductivity of the Cu−CN upon white light illumination under vacuum and a contactless measuring configuration. This photo‐assisted charge mobility is shown to play a key role in the increased reactivity and faradaic efficiency for the reduction of CO2.
Gold(I)‐Catalyzed Intermolecular Formal [4+2] Cycloaddition of O‐Aryl Ynol Ethers and Enol Ethers: Synthesis of Chromene Derivatives
Authors: Suárez‐Rodríguez Tatiana , Suárez‐Sobrino Ángel L. , Ballesteros Alfredo 
Published: July 2021

AbstractGold(I)‐catalyzed formal [4+2] cycloaddition of O‐aryl ynol ethers 1 and enol ethers 2 is described. This intermolecular reaction between two electron‐rich unsaturated systems takes place, under mild conditions, in the presence of 5 mol% [IPrAu(CH3CN)]SbF6 as catalyst giving chromene derivatives with good yields. The cycloaddition is completely regio‐ and stereoselective, as well as versatile for both reactives. Silyl enol ethers can also react in the same way and under the same reaction conditions with quantitative yields. A plausible mechanism through a selective addition of the enol ether to the alkyne gold activated complex followed by an intramolecular aromatic electrophilic substitution is proposed. Several experimental results support the presence of a cationic oxonium intermediate prior to the aromatic substitution. The reaction represents a new entry to the chromene core.
Nano‐Optical Tweezers: Methods and Applications for Trapping Single Molecules and Nanoparticles
Authors: Kolbow Joshua D. , Lindquist Nathan C. , Ertsgaard Christopher T. , Yoo Daehan , Oh Sang‐Hyun 
Published: July 2021

AbstractThe front cover artwork is provided by Prof. Sang‐Hyun Oh's group at the University of Minnesota. The image shows the optical trapping of chiral nanoparticles using coaxial nano‐optical tweezers, devices capable of harnessing light to manipulate objects a few nanometers in size. Read the full text of the Review at 10.1002/cphc.202100004.
Carminic Acid Based Red Dye from Scale Insects Detected in Red Ruby‐Crowned Kinglet Feathers by Surface‐Enhanced Raman Scattering
Authors: Wu Xuanyi , Sanchez‐Cortes Santiago , Kakoulli Ioanna 
Published: July 2021

AbstractIn most birds, red feather color is linked to diet and attributed to carotenoids contained in plants and fruits. In the red crown feathers of the Ruby‐crowned Kinglet (Regulus calendula), a new biopigment was identified based on carminic acid, the main coloring compound of cochineal (Dactylopius coccus) and other scale insects. This has revealed a potential new class of carminic acid‐based biopigments, not previously identified in feathers. In this research, red crown feathers of a Ruby‐crowned Kinglet were analyzed by surface‐enhanced Raman scattering (SERS) employing synthesized silver star‐shaped colloids as the nanoplasmonic platform. Results indicated peaks at 450, 670, 1290–1312, 1355, 1410, 1570, 1620 cm−1 in the feather SERS spectra characteristic of carminic acid. SERS has proven to be an extremely sensitive, non‐destructive technique for the identification of different feather biopigments, even at trace quantities and in the presence of other predominant coloring substances.