bluuebunny/crossref_metadata_2025_split huggingface dataset:
Antimicrobial and Antibiofilm Activity of Essential Oil of Cymbopogon citratus against Oral Microflora Associated with Dental Plaque
Authors: Ambade Sonia V. , Deshpande Neelima M. 
Published: September 2019

Aims: Dental biofilms are complex, multi-species microorganism communities that inhabit the oral cavity in the form of dental plaque which causes dental caries and periodontal diseases. The present study aims to explore the potential of Lemon Grass Essential Oil (LGEO) extracted from Cymbopogon citratus as antimicrobial and antibiofilm agent against the microorganisms responsible for dental plaque.
Study Design: Observational and comparison study.
Place and Duration of Study: Research centre, Department of Microbiology, Abasaheb Garware college, Pune, India, between Dec 2012 to Jan 2017.
Methodology: Three bacterial species primarily responsible for the biofilm formation were isolated from dental plaque and identified using 16S ribosomal RNA sequences. Five most primary colonizer of dental plaque organisms were acquired from the Microbial Type Culture Collection cultures. Antimicrobial as well as antibiofilm activity of LGEO, was determined against these eight biofilm forming microorganism. The antibiofilm activity of LGEO was evaluated against oral flora individually, as well as in consortium.
Results: LGEO displayed excellent antimicrobial activity against eight test organisms associated with dental plaque, representing four genera namely Streptococcus, Staphylococcus, Lactobacillus and Candida. MIC of LGEO for all test organisms was determined as 1.5% (v/v). The LGEO was found to exhibit as high as 76% biofilm inhibitory activity even in the consortium, where the biofilm formation sometimes has been noted to be comparatively more than that of the individual organism, making LGEO a very promising antibiofilm agent.
Conclusion: LGEO present in rampantly grown plant, Cymbopogon citratus, has remarkable antimicrobial and antibiofilm activity against the dental plaque organism and thus can be the economical, convenient, natural and nontoxic herbal material to effectively control the oral microflora associated with dental plaque.
Quantitative Phytochemical Analysis and Antifungal Susceptibility of Vernonia amygdalina against Some Strains of Candida albicans
Authors: Owoyale A. D. M. , Galadimma M. , Daniyan S. Y. , Adabara N. 
Published: September 2019

This study was aimed at determining the quantitative phytochemical analysis and antifungal susceptibility of Vernonia amygdalina against some strains of Candida albicans. Reflux method of extraction was used for the successive extraction of the leaves of Vernonia amygdalina. Quantitative phytochemical screenings were done to determine the amounts of phytochemicals that are present in the crude extracts, the study revealed that phytochemicals which include flavonoids, tannins, alkaloids, saponins and phenol were present in the crude extracts. Three different strains (P37005, RM1000 and SC5314) were subjected for antifungal susceptibility test, the antifungal susceptibility test of the crude extracts against the strains were determined at different concentrations of 40,60, 80 and 100 mg/ml using agar well diffusion method. The highest zone of inhibition (ZOI) was 21.00 ±0.30 mm which was recorded for methanol leaf extract (MLE) at a concentration of 100 mg/ml against SC5314 (isolate:B3). The MIC and MFC values for the most active crude extracts were 12.5 mg/ml and 100 mg/ml for the n-hexane crude extract against strain P37005 (isolate B1), the value of 12.5 mg/ml and 100 mg/ml was also revealed for the n-hexane crude extract against SC5314 (isolateB3) however, the methanol crude extract showed a value of 12.5mg/ml and 50mg/ml respectively against SC5314 (isolate:B3). The results from this study suggest that n-hexane and methanol crude extract have a better antifungal activity than the ethylacetate crude extract. This study also validate the claim of the local herbal practitioners of the use of the leaves of Vernonia amygdalina in curing candidiasis.
Phytochemical Screening, Anti-nutritional and Mineral Composition of Telfairia occidetallis (Fluted Pumpkin) and Cleome rutidosperma (Fringe Spider Flower)
Authors: Alexander Priscilla , Bwatanglang I. B. , Buba Adamu 
Published: September 2019

The study was conducted to investigate phytochemicals, anti-nutrients and mineral compostions of Telfeira occidentalis and Cleome rutidospermas leaves. The High Performance Chromatography (HPLC) was used in the Quantitative analysis of Phytochemicals as well as the anti-nutrient contents while the Elemental Compositions was analysed using Atomic Absorption Spectrophotometer (AAS) (Buck Scientific). The antinutrients content analysed were as follows hydrocyanic acid (31.0±0.001 and 25.0±0.001), oxalate (570±0.004 and 740±0.003), phytic acid (7.50±0.002 and 9.20±0.005 mg/100 g), for T. occidentallis and C. rutidosperma respectively and the values were all within the NAFADAC/WHO tolerable limit. The Minerals Compositions was found to be, Mn (1.684±0.40 and 0.718±0.31 mg/100 g), Zn (1.740±0.10 and 1.570±0.31 mg/100 g), Fe (3.823±0.03 and 4.329±0.01 mg/100 g), Na (2.572±0.42 and 2.659±0.80 mg/100 g), Ca (74.405±13.60 and 29.677±13.50 mg/100 g), Mg (35.277±10.05 and 12.438±10.4 mg/100 g), Cu (0.049±0.03 and 0.044±0.01 mg/100 g) for T. occidentallis and C. rutidosperma respectively. The presences of some secondary metabolites like alkaloids, flavonoids, terpenoids, tannins, cardiac glycosides and some essential minerals shows that the plants can be alternative sources of medicine. The results of the antinutrients indicated that the samples are free of toxic substances which might cause ill health to the body. Though, the anti-nutrient contents found in both T. occidentallis and C. rutidosperma were low, it will still be safer if these leaves were boiled for about 5 to 15 minutes to reduce the anti-nutritional factors significantly.
A Review on Principles and Applications of Scanning Thermal Microscopy (SThM)
Authors: Zhang Yun , Zhu Wenkai , Hui Fei , Lanza Mario , Borca‐Tasciuc Theodorian , Muñoz Rojo Miguel 
Published: September 2019

AbstractAs the size of materials, particles, and devices shrinks to nanometer, atomic, or even quantum scale, it is more challenging to characterize their thermal properties reliably. Scanning thermal microscopy (SThM) is an emerging method to obtain local thermal information by controlling and monitoring probe–sample thermal exchange processes. In this review, key experimental and theoretical components of the SThM system are discussed, including thermal probes and experimental methods, heat transfer mechanisms, calibration strategies, thermal exchange resistance, and effective heat transfer coefficients. Additionally, recent applications of SThM to novel materials and devices are reviewed, with emphasis on thermoelectric, biological, phase change, and 2D materials.
Solution‐Processed Laminated Perovskite Layers for High‐Performance Solar Cells
Authors: Wang Yangyang , Li Tianhao , Li Zengrong , Wang Sen , Deng Xianyu 
Published: September 2019

AbstractLaminated multilayers of perovskite films with different optical and electronic characteristics will easily realize high‐performance optoelectronic devices because it is widely demonstrated that differential distribution of film properties in the vertical direction of devices plays particularly important roles in device performance. However, the existing laminated perovskite films are hardly prepared by a solution process because there is no solvent with sufficient selectivity of solubility for different perovskite materials. Here, it is demonstrated that aniline (AN) has a largely different solubility toward the perovskite MAPbI3 and the MAPbI3 blend with an additive of hydrochloride diethylammonium chloride. By using AN as the solvent in the perovskite precursor solution, two laminated perovskite layers with different crystal size and optical and electrical characteristics are achieved. Inverted perovskite solar cells with the laminated films as active layers achieve an averaged power conversion efficiency of 20.65% originating from the high VOC 1.112 V and fill factor of 80.8%. The devices maintain 98% efficiency after 400 h under 65% RH. This work provides a very simple and feasible method for production of laminated perovskite films to achieve high‐performance perovskite solar cells.
Heterojunction Architecture of N‐Doped WO3 Nanobundles with Ce2S3 Nanodots Hybridized on a Carbon Textile Enables a Highly Efficient Flexible Photocatalyst
Authors: Huang Yongchao , Guo Zhongjie , Liu Hong , Zhang Shanqing , Wang Pingshan , Lu Jun , Tong Yexiang 
Published: September 2019

AbstractThe availability of robust, versatile, and efficient photocatalysts is the main bottleneck in practical applications of photocatalytic degradation of organic pollutants. Herein, N‐WO3/Ce2S3 nanotube bundles (NBs) are synthesized and successfully immobilized on a carbon textile, resulting in a flexible and conducting photocatalyst. Due to the large interfacial area between N‐WO3 and Ce2S3, the interwoven 3D carbon architecture and, more importantly, the establishment of a heterojunction between N‐WO3 and Ce2S3, the resultant photocatalyst exhibits excellent light absorption capacity and superior ability to separate photoinduced electron–hole pairs for the photocatalytic degradation of organic compounds in air and water media. Theoretical calculations confirm that the strong electronic interaction between N‐WO3 and Ce2S3 can be beneficial to the enhancement of the charge carrier transfer dynamics of the as‐prepared photocatalyst. This work provides a new protocol for constructing efficient flexible photocatalysts for application in environmental remediation.
A Molecular Dynamics Study on Self‐Assembly of Single‐Walled Carbon Nanotubes: From Molecular Morphology and Binding Energy
Authors: Zhang Jianwei , Cui Jianlei , Cheng Yang , Wang Wenjun , He Xiaoqiao , Mei Xuesong 
Published: September 2019

AbstractMolecular dynamics simulations are used to reveal the adsorption behavior of modified single‐walled carbon nanotubes (M‐SWNTs) on the functionalized surfaces (F‐surfaces) bound to a silicon dioxide substrate, in order to illustrate the mechanism of patterned self‐assembly of SWNTs on the atomic scale. Noncovalent modification strategy with surfactants is adopted to investigate the structural transition of the surfactant on SWNTs in aqueous solution. Core/shell hybrid structures are formed ultimately by the surfactant scrolling onto SWNTs periphery. Two different kinds of silanes are used to control the wettability of the F‐surfaces from hydrophobic to hydrophilic. An excluded‐volume constraints algorithm is employed to calculate the global energy minimum to rationalize the driving force controlling the behavior evolution. The mechanisms for self‐assembly are illustrated in two segments in detail that the electrostatic attraction starts the self‐assembly program on the hydrophilic surface, while van der Waals interaction plays an important role in the behavior of nonassembly to the hydrophobic surface. The results are not only helpful to understand many phenomena in the self‐assembly process on the atomic scale but also will provide meaningful guidance in fabrication of SWNTs patterns to keep fidelity.
Carbon Black from Diesel Soot for High‐Performance Wearable Pressure Sensors
Authors: Liu Kangning , Yu Junsheng , Li Ying , Yan Xingwu , Bai Dongyu , Liao Xiaoqing , Zhou Ziqiang , Gao Yuanyuan , Yang Xin , Li Lu 
Published: September 2019

AbstractThe rational design of high‐performance flexible pressure sensors with both high sensitivity and large workable range attracts great attentions due to the potential applications in wearable electronics and human–machine interfaces. Here, carbon black (CB) from diesel soot, an air pollutant produced during incomplete combustion of hydrocarbon fuels, is used as the active material to construct high‐performance flexible all‐textile pressure sensors. Due to the unique hierarchical structures and large surface roughness of the CB‐coated fabric, the pressure sensor exhibits outstanding performances, such as high sensitivity (81.61 kPa−1 within the range of 0–10 kPa), extrawide workable pressure regime (0–100 kPa), and rapid response and relaxation time (6 and 30 ms, respectively). Based on these superior sensing properties, its practical applications are demonstrated in detecting the signals of musical sound and of human physiology, showing its potential for health monitoring as wearable electronics.
Enhanced Tunable Light Absorption in Nanostructured Si Arrays Based on Double‐Quarter‐Wavelength Resonance
Authors: Li Zhigang , Feng Shangshen , Liu Yanping , Hu Jinlian , Wang Caifen , Wei Bingqing 
Published: September 2019

AbstractSimultaneously tuning light absorption wavelength and absorbance is a critical challenge in photoelectric detection, mimic of photosynthesis, and simulation of photoreceptors in some animals' retinas. Here, highly ordered hexagonal nanostructured Si arrays are fabricated using monolayer colloid crystal templates. A quantitative relationship between geometric size and light absorption is unveiled in the Si arrays, namely double‐quarter‐wavelength resonance (DQWR). Based on the DQWR model, the absorption wavelength can be readily tuned from 200 to 2400 nm, and the absorbance can be enhanced from ≈80% to above 99% in the full spectrum. Due to the hemisphere‐shell structural feature of the Si arrays, excellent omnidirectional antireflective performance can also be realized. Most importantly, the outstanding antireflection performance of the nanostructures is independent of the substrate. The results not only have important implications for understanding the antireflective mechanism of the nanostructured arrays, but also endow the approach promising in diverse applications, including biomimicry, antireflective film, infrared imagery, and other optoelectronic devices.
Ultrafast Terahertz Frequency and Phase Tuning by All‐Optical Molecularization of Metasurfaces
Authors: Hu Yuze , Jiang Tian , Zhou Junhu , Hao Hao , Sun Hao , Ouyang Hao , Tong Mingyu , Tang Yuxiang , Li Han , You Jie , Zheng Xin , Xu Zhongjie , Cheng Xiangai 
Published: September 2019

AbstractThe integration of photoactive semiconductors exhibiting strong light–matter interactions into functional unit meta‐atoms facilitates effective approaches to dynamically manipulate terahertz (THz) waves. Here, a new metaphotonic modulator is proposed and comprehensively studied, which demonstrates extensive tunability of the resonant frequency and phase with the merit of ultrafast photoswitching. Specifically, parallel silicon (Si) bridges are embedded in metasurfaces to reinforce the connection ability, achieving ultrafast optical molecularization from a magnetic quadrupole into an electric dipole. Under femtosecond pulse excitation, the demonstrated resonant frequency tuning range is as high as 40% (from 1.16 to 0.7 THz) and can be further promoted up to 48% (from 1.56 to 0.81 THz) by varying the Si bridge length. Meanwhile, the phase delay at given frequencies can be controlled up to 53.3° without significantly changing the high transmission. Furthermore, the transient frequency switching and phase shifting dynamics are systematically investigated for the first time, showing a full recovery time within 2 ns. By optically molecularizing metasurfaces, extended tuning ranges with regard to the resonant frequency and phase, as well as an ultrafast switching speed, are simultaneously acquired in the proposed metamodulator, which provides deeper insight into the multifunctional active‐tuning systems.
Iron(III) Chloride/Phenylsilane‐Mediated Cascade Reaction of Allyl Alcohols with Maleimides: Synthesis of Poly‐Substituted γ‐Butyrolactones
Authors: Zhang Hua , Zhan Xiao‐Yu , Chen Xu‐Ling , Tang Lei , He Shuai , Shi Zhi‐Chuan , Wang Yu , Wang Ji‐Yu 
Published: September 2019

AbstractA iron‐catalyzed free radical cascade reaction of allyl alcohols with N‐substituted maleimides for accessing poly‐substituted γ‐butyrolactones has been developed. In this protocol, various allyl alcohols can open N‐substituted maleimide rings to form allyl ester intermediates, and the allyl ester intermediates can be converted into an allyl ester alkyl radicals and undergo intramolecular free radical addition cyclization to form a polysubstituted γ‐butyrolactones. In this protocol, spiro γ‐butyrolactone compounds can be also synthesized. Meanwhile, the strategy could be applied to further construct a fully substituted tetrahydrofuran. The reaction is not sensitive to oxygen or moisture and has been performed on gram‐scale.magnified image
Symmetry Reductions, Group‐Invariant Solutions, and Conservation Laws of a (2+1)‐Dimensional Nonlinear Schrödinger Equation in a Heisenberg Ferromagnetic Spin Chain
Authors: Du Xia‐Xia , Tian Bo , Yuan Yu‐Qiang , Du Zhong 
Published: September 2019

AbstractNonlinear spin excitations in ferromagnetic spin chains are studied for spintronic and magnetic devices including magnetic‐field sensors and for high‐density data storage. Here, (2+1)‐dimensional nonlinear Schrödinger equation is investigated, which describes the nonlinear spin dynamics for a Heisenberg ferromagnetic spin chain. Lie point symmetry generators and Lie symmetry groups of that equation are derived. Lie symmetry groups are related to the time, space, scale, rotation transformations, and Galilean boosts of that equation. Certain solutions, which are associated with the known solutions, are constructed. Based on the Lie symmetry generators, the reduced systems of such an equation are obtained. Based on the polynomial expansion and through one of the reduced systems, group‐invariant solutions are constructed. Soliton‐type group‐invariant solutions are graphically investigated and effects of the magnetic coupling coefficients, that is, α1, α2, α3, and α4, on the soliton's amplitude, width, and velocity are discussed. It is seen that α1, α2, α3, and α4 have no influence on the soliton's amplitude, but can affect the soliton's velocity and width. Lax pair and conservation laws of such an equation are derived.
Room‐Temperature Insulating Ferromagnetic (Ni,Co)1+2xTi1−xO3 Thin Films
Authors: Fujioka Yukari , Frantti Johannes , Rouleau Christopher , Puretzky Alexander , Gai Zheng , Lavrik Nickolay , Herklotz Andreas , Ivanov Ilia , Meyer Harry 
Published: September 2019

AbstractInsulating uniaxial room‐temperature ferromagnets are a prerequisite for commonplace spin wave‐based devices, the obstacle in contemporary ferromagnets being the coupling of ferromagnetism with large conductivity. It is shown that the uniaxial A1 + 2xTi4+1 − xO3 (ATO), A = Ni2+,Co2+, and 0.6 < x ≤ 1, thin films are electrically insulating ferromagnets already at room temperature. The octahedra network of the ATO and the corundum and ilmenite structures are the same yet different octahedra‐filling proved to be a route to switch from the antiferromagnetic to ferromagnetic regime. Octahedra can continuously be filled up to x = 1, or vacated (−0.24 < x < 0) in the ATO structure. TiO‐layers, which separate the ferromagnetic (Ni,Co)O‐layers and intermediate the antiferromagnetic coupling between the ferromagnetic layers in the NiTiO3 and CoTiO3 ilmenites, can continuously be replaced by (Ni,Co)O‐layers to convert the ATO‐films to ferromagnetic insulator with abundant direct cation interactions.
Synthesis of Imines via Reactions of Benzyl Alcohol with Amines Using Half‐Sandwich (η6‐p‐cymene) Ruthenium(II) Complexes Stabilised by 2‐aminofluorene Derivatives
Authors: Vinoth Govindasamy , Indira Sekar , Bharathi Madheswaran , Durgadevi Anandhan , Abinaya Ravikumar , Alves Luis G. , Martins Ana Margarida , Bharathi Kuppannan Shanmuga 
Published: September 2019

A new class of half‐sandwich (η6‐p‐cymene) ruthenium(II) complexes supported by 2‐aminofluorene derivatives [Ru(η6‐p‐cymene)(Cl)(L)] (L = 2‐(((9H‐fluoren‐2‐yl)imino)methyl)phenol (L1), 2‐(((9H‐fluoren‐2‐yl)imino)methyl)‐3‐methoxyphenol (L2), 1‐(((9H‐fluoren‐2‐yl)imino)methyl)naphthalene‐2‐ol (L3) and N‐((1H‐pyrrol‐2‐yl)methylene)‐9H‐fluorene‐2‐amine (L4)) were synthesized. All compounds were fully characterized by analytical and spectroscopic techniques (IR, UV–Vis, NMR) and also by mass spectrometry. The solid state molecular structures of the complexes [Ru(η6‐p‐cymene)(Cl)(L2)], [Ru(η6‐p‐cymene)(Cl)(L3)] and [Ru(η6‐p‐cymene)(Cl)(L4)] revealed that the 2‐aminofluorene and p‐cymene moieties coordinate to ruthenium(II) in a three‐legged piano‐stool geometry. The synthesized complexes were used as catalysts for the dehydrogenative coupling of benzyl alcohol with a range of amines (aliphatic, aromatic and heterocyclic). The reactions were carried out under thermal heating, ultrasound and microwave assistance, using solvent or solvent free conditions, and the catalytic performance was optimized regarding the solvent, the type of base, the catalyst loading and the temperature. Moderately high to very high isolated yields were obtained using [Ru(η6‐p‐cymene)(Cl)(L4)] at 1 mol%. In general, microwave irradiation produced better yields than the other two techniques irrespective of the nature of the substituents.
Durchstanztragverhalten von Flachdecken mit variierenden Durchstanzbewehrungsgraden
Authors: Schmidt Philipp , Kueres Dominik , Claßen Martin , Hegger Josef 
Published: September 2019

AbstractMit der bauaufsichtlichen Einführung des Eurocode 2 in Deutschland wurde die Durchstanzbemessung von Flachdecken neu geregelt. Seitdem ergibt sich die Durchstanztragfähigkeit mit Durchstanzbewehrung aus der Summe eines konstanten Betontraganteils und eines Stahltraganteils, der unabhängig vom Bauteil aus einem 33°‐Fachwerk resultiert. Für die Berechnung des Stahltraganteils wird gemäß Eurocode 2 eine reduzierte Stahlfestigkeit in Abhängigkeit von der statischen Nutzhöhe angesetzt, wodurch die Verankerungsqualität der Durchstanzbewehrung berücksichtigt wird. Auf Basis einer Datenbankauswertung und eines Vergleichs des Sicherheitsniveaus mit der damaligen DIN 1045‐1 wurden im Deutschen Anhang zum Eurocode 2 (EC2+NA(D)) zusätzliche Erhöhungsfaktoren für die ersten beiden Durchstanzbewehrungsreihen ergänzt, die nahezu zu einer Verdopplung der Durchstanzbewehrungsmenge führen. Während zur Bewertung der Bemessungsgleichungen für die Ermittlung der Durchstanztragfähigkeit ohne Durchstanzbewehrung und auf dem Niveau der maximalen Durchstanztragfähigkeit zahlreiche Versuchsergebnisse vorliegen, sind bislang nur sehr wenige Versuchsreihen an Flachdeckenausschnitten mit einem Durchstanzversagen innerhalb des durchstanzbewehrten Bereichs vorhanden.Zur systematischen Untersuchung des Durchstanztragverhaltens von Flachdecken mit Bügeln als Durchstanzbewehrung wurden daher insgesamt drei Versuchsserien mit variierenden Durchstanzbewehrungsgraden durchgeführt. Das Versuchsprogramm umfasste drei Referenzversuche ohne Durchstanzbewehrung und acht Versuchskörper mit geringen und mittleren Durchstanzbewehrungsgraden. Dabei erfolgte die Variation der Durchstanzbewehrungsmenge jeweils ausschließlich über den Bügeldurchmesser. Weitere untersuchte Einflussparameter waren die Schubschlankheit und die statische Nutzhöhe. Im vorliegenden Beitrag werden die durchgeführten Versuche vorgestellt und die Versuchsergebnisse diskutiert. Durch den Vergleich der experimentell ermittelten Bruchlasten mit den rechnerischen Durchstanztragfähigkeiten nach Eurocode 2 und EC2+NA(D) können die bestehenden normativen Regeln bewertet werden. Darüber hinaus werden die Bemessungsregeln nach Model Code 2010 in die Bewertung mit einbezogen.