bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and Cytotoxicity of Novel Indoloquinolines and Benzonaphthyridines from 4‐Chloro‐2,8‐dimethylquinoline and Variety of Hetero Amines
Authors: Prabha Kolandaivel , Satheeshkumar Rajendran , Prasad K. J. Rajendra 
Published: July 2021

AbstractThe synthesis of hetero substituted indoloquinolines and thiophene substituted benzonaphthyridienes from two heterocycles tethered by nitrogen or sulfur intermediates. Further it was cyclized using Pd(OAc)2 catalyst to yield products, i. e., various heteroindolo quinolines and polyphosphoric acid (PPA) mediated thiophene substituted naphthyridines. All the potential intermediates and their respective final products were screened for anticancer activity against HeLa and K562 cancer cells, and it showed good cytotoxicity against HeLa and K562 cells compared standard Adriamycin (ADR) drugs. Among the newly synthesized compounds, compounds 3 a, 3 b, 4 b and 5 a displayed stronger cytotoxic activity against both HeLa and K562 cells compared standard Adriamycin (ADR) drug. This might be due to the presence of benzothiazole and isoquinoline moieties, which enhanced the cytotoxic activity. Subsequently, compounds 3 c, 3 d, 4 a, 5 b and 7 also showed better cytotoxic activity with IC50 values <19 μM against HeLa and K562 cells, which was due to the presence of quinoline and thiophene moieties, which enhanced the cytotoxic activity.
Metal‐Free g‐C3N4/Graphite Composite Based Carbocatalyst for Epoxidation of Styrene
Authors: Dogra Ashima , Kumar Anil , Kapoor Mohit , Gupta Neeraj 
Published: July 2021

AbstractTuning graphitic surface with nitrogen functionalities renders potential carbocatalysts for a wide range of reactions. Herein, g‐C3N4/graphite composite material (g‐C3N4@G) is reported for oxidation of styrene to styrene oxide. The detailed physiochemical properties of g‐C3N4@G are investigated by X‐ray photoelectron spectroscopy (XPS), Transmission electron microscopy (TEM), Scanning electron microscopy (SEM), X‐ray diffraction (XRD) and Fourier transmission infrared spectroscopy (FTIR) analysis. The TEM and SEM micrographs indicate the formation of g‐C3N4 sheets and N1s XPS results confirm the formation of g‐C3N4 on the graphitic surface. The role of specific catalytic sites is experimentally studied by the use of model catalysts those mimic the functional groups on the surface of g‐C3N4@G. It is suggested that the catalytic sites on the surface showcase a synergeistic effect, with sp2 hybridized N site being most selective for styrene oxide.
Oxamide Derivatives as Potent α‐Glucosidase Inhibitors: Design, Synthesis, In Vitro Inhibitory Screening and In Silico Docking Studies
Authors: Malik Naseema Perveen , Naz Maira , Ashiq Uzma , Jamal Rifat A. , Gul Sana , Saleem Faiza , Khan Khalid M. , Yousuf Sammer 
Published: July 2021

AbstractDiabetes mellitus (DM) is a well‐known progressive endocrine disorder and has become a serious worldwide medical concern stimulating the search for new therapeutic agents. In the current study, nitrogen and oxygen based twenty oxamide derivatives were synthesized and their potential to inhibit α‐glucosidase enzyme was studied. Oxamides were synthesized using oxalyl chloride and corresponding aniline in 1 : 2 ratio in basic medium. Structures of these compounds were determined by mass spectrometry, various spectroscopic techniques such as 1H‐NMR, and IR spectroscopy as well as X‐ray diffraction studies. Additionally, computational approach was applied for the calculation of vibrational frequencies of oxamide derivatives and both techniques showed comparable results. Good to moderate inhibitory activities were observed for all synthetic derivatives against α‐glucosidase enzyme. Off twenty (20), nine (9) compounds were found to exhibit good inhibitory activities (IC50 ranges in between 38.2‐75.8 μM) when compared with the standard 1‐deoxynojirimycin (DNJ) with IC50=425.6±1.3 μM. Molecular docking studies were performed for the evaluation of binding mechanism of oxamide compounds in the pocket of α‐glucosidase enzyme. Docking scores based on EADock score, inhibitory activities and docking energies showed similar trend of inhibition.Introduction
Constructing CuBi2O4/Ag3PO4 Photocatalyst with Improved Photocatalytic Performance for the Degradation of Tetracycline under Visible‐Light Irradiation
Authors: Ding Meng , Chen Xuehang , Ma Xiaoran , Liu Yutong , Wang Xiao , Xu Xijin 
Published: July 2021

AbstractConstructing highly efficient heterojunction photocatalyst is vital but difficult for solving the environmental crises. The CuBi2O4/Ag3PO4 photocatalyst has been synthesized by hydrothermal and solution precipitating method. The fabricated CuBi2O4/Ag3PO4 composite exhibits improved property for the degradation of tetracycline (TC) and nearly 80 % of TC (50 mg/L) is degraded within 30 min, especially its rate constant (k=0.04366 min−1) is about 13.48 and 1.63 times higher than those of pure CuBi2O4 (0.003240 min−1) and Ag3PO4 (0.02676 min−1). The excellent photocatalytic performance was attributed to the heterojunction interfaces and the effective separation of the photo‐generated carriers driven by the reasonable energy band alignment in the heterostructure. The CuBi2O4/Ag3PO4 composite displays good stability, and the present of different inorganic ions has rather small effect on the degradation of TC. A possible photocatalytic mechanism of CuBi2O4/Ag3PO4 composite is proposed based on the active species trapping experiment. It proves that the CuBi2O4/Ag3PO4 composite has potential application in environmental remediation.
Synthesized Two New Water‐Soluble Fluorescents Calix[4]arene 4‐sulfo‐1,8‐naphthalimide Derivatives Inhibit Proliferation of Human Colorectal Carcinoma Cells
Authors: Yildirim Ayse , Karakurt Serdar , Yilmaz Mustafa 
Published: July 2021

AbstractSynthesis of 1,8‐naphthalimide derivatives and biochemical studies using them as anti‐cancer and cellular imaging agents have attracted significant attention in recent years. This study aimed to synthesize two new fluorescent narrow rim‐functionalized 4‐sulfo‐1,8‐naphthalimide derivatives of calix[4]arenes (4 and 7) and examination of their cytotoxic properties for cancerous cells. For this purpose, p‐tert‐butylcalix[4]arene bearing dihydrazide (3) or diaminopropyl (6) units on its narrow rim were reacted with 4‐sulfo‐1,8‐naphthalic anhydrate. The structure of these synthesized compounds has been characterized using 1H‐NMR, 13C‐NMR, and FTIR techniques. To investigate the anti‐cancer properties, compounds 4, 7, and N,N‐dimethylaminoethyl‐1,8‐naphthalimide (8) were tested on the human colorectal cancer cell line (DLD‐1) as well as healthy colon epithelial cell line (CCD‐18Co). The IC50 values of 4 and 7 were determined as 12.95 μM and 16.13 μM, respectively, on DLD‐1 cells. Furthermore, following the treatment of CCD‐18Co cells with 4 and 7, the IC50 values were determined as 508 μM and 269 μM, respectively. However, it was observed that compound 8 had no cytotoxic effect on both DLD‐1 cells and CCD‐18Co cells. Furthermore, the fluorescence imaging of human colorectal cancer cells treated with the synthesized compounds (4, 7, and 8) was performed on living cells.
Enhanced Electrochemical Performance of 5V LiNi0.5Mn1.5‐xZrxO4 Cathode Material for Lithium‐Ion Batteries
Authors: Gong Jiajia , Fu Shaoxiong , Zhang Yuan , Yan Shuaipeng , Lang Yaqiang , Guo Jianling , Wang Li , Liang Guangchuan 
Published: July 2021

AbstractSeries of LiNi0.5Mn1.5‐xZrxO4 (x=0, 0.0025, 0.005, 0.01, 0.02) samples have been prepared by a combined coprecipitation‐hydrothermal method followed by two‐step calcination. The effects of Zr4+ doping contents on the structure, morphology and electrochemical properties are studied. The results show that Zr4+ doping reduces Mn3+ content and Ni/Mn disordering degree. Additionally, Zr4+ doping reduces primary particle size and agglomeration degree. More significantly, Zr4+ doping leads to the appearance of higher‐surface‐energy {110} and/or {311} facets, while undoped sample only consists of {111} and {100} facets. But excessive Zr4+ doping (x=0.02) leads to the decrease of higher‐surface‐energy facets. Electrochemical results show that appropriate Zr4+ doping improves the rate and cycling performances of LiNi0.5Mn1.5O4 material. Among them, LiNi0.5Mn1.495Zr0.005O4 shows the optimal electrochemical performance, which can be attributed to high phase purity, high crystallinity, appropriate primary particle size and agglomeration degree, enlarged lattice constant, and greater exposure of {110} and/or {311} facets.
Highly Selective and Sensitive Sulfonylhydrazone Type Fluorescent Probe for Rapid Detection of Mercury(II) and Its Application in Logic Gate and Adsorption
Authors: Xue Songsong , Xie Zhengfeng , Wen Yiping , He Jiawei , Liu Yucheng , Shi Wei 
Published: July 2021

AbstractIn this study, 4‐bromotriphenylamine, 5‐formaldehyde thiophene‐2‐boronic acid and benzenesulfonyl hydrazide were used as materials to synthesize a novel type of Schiff base fluorescent probe molecule N′‐((5‐(4‐(diphenylamino)phenyl)thiophen‐2‐yl)methylene)benzenesulfonohydrazide (BS), and its structure was characterized by nuclear magnetic resonance (NMR) and high resolution mass spectrometry (HR‐MS). BS exhibited excellent solvatochromic effect and aggregation‐induced emission enhancement, and had rapid recognition, high selectivity and specificity for Hg2+, the detection limit was as low as 2.84×10−8 M, and the response time is only 15 s. It has passed the 1H NMR titration experiment verified its possible response mechanism. Through the good reversible performance of BS, molecular logic gate was constructed with Hg2+ and EDTA as chemical inputs. In practical applications, polyacrylamide (PAM) doped BS (PAM‐BS) could achieve high‐efficiency adsorption of Hg2+, with a removal rate of 99.93 %, and the microscopic morphology and element changes before and after PAM‐BS adsorption were compared by SEM‐EDS.
Colorimetric Detection of Cholesterol Based on the Peroxidase‐Like Activity of Metal‐Organic Framework MIL‐101(Cr)
Authors: Liu Luying , Wang Jingshan , Wang Jing , Wu Jiating , Wu Shuping , Xie Lijun 
Published: July 2021

AbstractEfficient quantitative determination of cholesterol has important application value in drug testing and clinical diagnosis of cardiovascular diseases. In this work, a metal‐organic framework MIL‐101(Cr) (MIL=Materials of Institute Lavoisier) was synthesized and developed as a peroxidase mimic for colorimetric detection of cholesterol. Kinetic analysis indicated that the MIL‐101(Cr) nanoparticles showed a higher Vmax (2.27*10−7 MS−1) and a lower Km (0.07 mM) than the natural horseradish peroxidase (HRP). An effective colorimetric sensor has been proven to detect cholesterol. Based on the outstanding catalytic activity, the colorimetric sensor displayed a linear response for cholesterol in the concentration range from 1.1 μM to 22.9 μM and the detection limit as low as 0.86 μM. Furthermore, the proposed method based on MIL‐101(Cr) nanoparticles showed a favorable reproducibility and recovery. The sensor had been successfully applied to determine serum cholesterol level in mice and human, respectively.
Entrepreneurial learning and strategic foresight
Authors: Peterson Aticus , Wu Andy 
Published: July 2021

AbstractResearch SummaryWe study how learning by experience across projects affects an entrepreneur's strategic foresight. In a quantitative study of 314 entrepreneurs across 722 crowdfunded projects supplemented with a program of qualitative interviews, we counterintuitively find that entrepreneurs make less accurate predictions as they gain experience executing projects: they miss their predicted timeline to bring a product to market by nearly six additional weeks on each successive project. Although learning should improve prediction accuracy in principle, we argue that entrepreneurs also learn of opportunities to augment each successive product, which drastically expands the interdependencies beyond what an entrepreneur can anticipate. We find that entrepreneurs encounter more unforeseen interdependencies in their subsequent projects, and they sacrifice on‐time delivery to address these interdependencies.Managerial SummaryEntrepreneurs consistently struggle to set timelines that they can meet. And, counterintuitively, accumulating experience can actually make this problem even worse: experienced entrepreneurs can miss timelines by even wider margins on subsequent projects. In our study of crowdfunding entrepreneurs launching hardware technology products, we find that entrepreneurs fail to anticipate how many more things can go wrong when they do something even just a little bit more challenging on their next project. In other words, the number of unknown unknowns in a project increases very rapidly even when making only simple improvements on a product. We argue that entrepreneurs can more accurately predict their timelines by intentionally accounting for the rapid increase in things that can go wrong.
Advances in Si and SiC Materials for High‐Performance Supercapacitors toward Integrated Energy Storage Systems
Authors: Nguyen Tuan Kien , Aberoumand Sadegh , Dao Dzung Viet 
Published: July 2021

AbstractSilicon (Si), as the second most abundant element on Earth, has been a central platform of modern electronics owing to its low mass density and unique semiconductor properties. From an energy perspective, all‐in‐one integration of power supply systems onto Si‐based functional devices is highly desirable, which inspires significant study on Si‐based energy storage. Compared to the well‐known Si‐anode Li‐ion batteries, Si‐based supercapacitors possess high power density, long life, and simple working mechanisms, which enables their ease of integration onto a wide range of devices and applications. Besides Si, silicon carbide (SiC), as a physicochemically stable wide‐bandgap semiconductor, also attracts research attention as an energy storage material in harsh environments. In this review, a detailed overview of latest advances in materials design, synthesis methods, and performances of Si‐based and SiC‐based supercapacitors will be provided. Some successful integrated devices, future perspectives, and potential research directions are also highlighted and discussed.
Quantitative Förster Resonance Energy Transfer: Efficient Light Harvesting for Sequential Photo‐Thermo‐Electric Conversion
Authors: Fu Kuo , Zeng Xiaoxuan , Zhao Xinpeng , Wu Yue , Li Meng , Li Xin‐Shun , Pan Chengjun , Chen Zhijun , Yu Zhen‐Qiang 
Published: July 2021

AbstractLight is essential to all life on the earth. Thus, highly efficient light‐harvesting systems with the sequential energy transfer process are significant for using solar energy in photosynthesis. For developing an efficient light‐harvesting system, a liquid aggregation‐induced emission (AIE) dye TPE‐EA is obtained, as a donor and solvent, which can light up the aggregation caused quenching (ACQ) Nile Red (NiR, acceptor) to construct a quantitative Förster resonance energy transfer (FRET) system in NiR⊂TPE‐EA. Impressively, this FRET pair shows an impressive photothermal effect, producing a peak temperature of 119 °C while excited by UV light, with 37.8% of conversion efficiency. NiR⊂TPE‐EA is quite different from most other photothermal materials, which require excitation with long wavelength light (>520 nm). Therefore, NiR⊂TPE‐EA firstly converts the solar into thermal energy and then into electric energy to achieve sequential photo‐thermo‐electric conversion. Such sequential conversion, suitable for being excited by sunlight, is anticipated to unlock new and smart approaches for capturing solar energy.
Enhancing the Involvement Load Hypothesis as a Tool for Classroom Vocabulary Research
Authors: Hazrat Mandana , Read John 
Published: July 2021

AbstractThe Involvement Load Hypothesis (ILH) is a framework for designing vocabulary‐learning tasks which was proposed by Batia Laufer and Jan Hulstijn in 2001. It assumes that task effectiveness depends on three components induced by a task: a motivational component (need) and two cognitive components (search and evaluation). The hypothesis has been investigated in numerous studies, which have provided varying degrees of support for it. This article reviews the ILH 20 years after it was first proposed and addresses issues arising from the research. The first category of issues is related to the assumptions of the hypothesis, including uncertainty about the relative weight of the components, lack of evidence regarding the effect of the distribution of the components, and the limited range of scores available to assign to tasks. The second category involves variables affecting the predictive ability of the hypothesis, including time on task, level of proficiency, and frequency of exposure. Two studies, which investigated these issues, are discussed. One of them suggested extending evaluation, clarifying the role of search, and redefining need to solve the issues related to the assumptions. The other revealed the effects of the variables in addition to showing the usefulness of the framework for predicting task effectiveness and the relative weight of the components. Issues that remained unresolved are discussed.
Feasibility study on prepolarized surface nuclear magnetic resonance for soil moisture measurements
Authors: Hiller Thomas , Costabel Stephan , Radić Tino , Dlugosch Raphael , Müller‐Petke Mike 
Published: July 2021

AbstractIn the past few years, small‐scale (2 m) prepolarized surface nuclear magnetic resonance (SNMR) has gained increasing interest in the research community. As recent studies demonstrated, the application of a strong prepolarization field enhances the SNMR signal of coils with a footprint <1 m2 up to a level that even enables investigations in urban areas. In particular, it is expected that this noninvasive method provides the soil moisture distribution in the upper 2 m of the subsurface in the near future. However, until now all field experiments have been carried out on water reservoirs only, in an approach to test and implement this rather new technique into the field of SNMR applications. We present the first prepolarized SNMR measurement on a real soil and demonstrate the general feasibility of this technique to qualitatively and quantitatively detect soil moisture in the upper first 0.5 m. Our soil moisture measurements are validated by independent time domain reflectometry data. To complement the field experiments with numerical simulations, we adapted the underlying SNMR spin dynamics simulations and account for prepolarization switch‐off effects in the forward modeling of the SNMR excitation.
Sequential deconfinement in 3d $$ \mathcal{N} $$ = 2 gauge theories
Authors: Benvenuti Sergio , Garozzo Ivan , Lo Monaco Gabriele 
Published: July 2021

Abstract
We consider 3d$$ \mathcal{N} $$
N
= 2 gauge theories with fundamental matter plus a single field in a rank-2 representation. Using iteratively a process of “deconfinement” of the rank-2 field, we produce a sequence of Seiberg-dual quiver theories. We detail this process in two examples with zero superpotential: Usp(2N) gauge theory with an antisymmetric field and U(N) gauge theory with an adjoint field. The fully deconfined dual quiver has N nodes, and can be interpreted as an Aharony dual of theories with rank-2 matter. All chiral ring generators of the original theory are mapped into gauge singlet fields of the fully deconfined quiver dual.
Distortion of a polycrystalline Al bar in a vice fixture: molecular dynamics analysis of grain movement and rotation
Authors: Vardanyan Vardan Hoviki , Linke Barbara S. , Urbassek Herbert M. 
Published: July 2021

AbstractThe deformation of a nano-sized polycrystalline Al bar under the action of vice plates is studied using molecular dynamics simulation. Two grain sizes are considered, fine-grained and coarse-grained. Deformation in the fine-grained sample is mainly caused by grain-boundary processes which induce grain displacement and rotation. Deformation in the coarse-grained sample is caused by grain-boundary processes and dislocation plasticity. The sample distortion manifests itself by the center-of-mass motion of the grains. Grain rotation is responsible for surface roughening after the loading process. While the plastic deformation is caused by the loading process, grain rearrangements under load release also contribute considerably to the final sample distortion.
Möglichkeiten und Grenzen der forensischen DNA-Analyse unter dem Gesichtspunkt verschiedener Szenarien zur Spurenentstehung
Authors: Vennemann Marielle , Oppelt Claus , Grethe Stefanie , Anslinger Katja , Fimmers Rolf , Schneider Harald , Hohoff Carsten , Eckert Martin , Rothämel Thomas , Schneider Peter M. ,   als Mitglieder der Spurenkommission, der gemeinsamen Kommission rechtsmedizinischer und kriminaltechnischer Institute
Published: July 2021

ZusammenfassungDie forensische DNA-Analyse hat sich in den letzten Jahrzehnten mit zunehmender Sensitivität und gleichzeitiger Standardisierung der Methodik zu einem festen Bestandteilteil der Strafverfolgung entwickelt. Dank der ständigen Verbesserung der Analysemethoden ist es zwischenzeitlich nahezu selbstverständlich, immer kleinere, latente DNA-Spuren erfolgreich zu typisieren. Dies führt mehr und mehr zu einer Verlagerung der Sachverständigentätigkeit in die Bewertung komplexer Spurenszenarien im Rahmen einer Hauptverhandlung: Anstelle der Zuordnung einer Spur zu einer Person rückt die Spurenentstehung bzw. die Möglichkeit eines DNA-Transfers ohne Bezug zu einer strafrechtlich relevanten Handlung in den Fokus der Diskussion. Aus Sicht der Deutschen Spurenkommission erscheint es notwendig, das Bewusstsein für mögliche alternative Szenarien zur Spurenentstehung zu schärfen. Zur Einordnung eines DNA-Ergebnisses in den Kontext der übrigen Sachbeweise eines konkreten Fallszenarios wird im vorliegenden Beitrag das bereits in der internationalen Fachliteratur seit geraumer Zeit etablierte Konzept der „Hierarchie der Hypothesen“ vorgestellt. Darüber hinaus werden die wissenschaftlichen Grundlagen zur Bewertung alternativer Szenarien des DNA-Transfers erläutert und gleichzeitig die Möglichkeiten und Grenzen einer gutachterlichen Stellungnahme dargestellt.
Spectrum and convergence of eventually positive operator semigroups
Authors: Arora Sahiba , Glück Jochen 
Published: July 2021

AbstractAn intriguing feature of positive$$C_0$$C0-semigroups on function spaces (or more generally on Banach lattices) is that their long-time behaviour is much easier to describe than it is for general semigroups. In particular, the convergence of semigroup operators (strongly or in the operator norm) as time tends to infinity can be characterized by a set of simple spectral and compactness conditions. In the present paper, we show that similar theorems remain true for the larger class of (uniformly) eventually positive semigroups—which recently arose in the study of various concrete differential equations. A major step in one of our characterizations is to show a version of the famous Niiro–Sawashima theorem for eventually positive operators. Several proofs for positive operators and semigroups do not work in our setting any longer, necessitating different arguments and giving our approach a distinct flavour.