bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Laser Speed on Cutting Characteristics of Cement-Based Materials
Authors: Lee Dongkyoung , Seo Youngjin , Pyo Sukhoon
Published: June 2018

The results of an experimental investigation on the physical and chemical characteristics of cement-based materials under laser interactions are presented. The laser cutting tests were conducted using a multi-mode continuous fiber laser with a laser power of 1 kW. The experimental variables were laser speed, water to cement ratio, and material compositions including cement paste, cement mortar, and ultra high-performance concrete (UHPC). In order to evaluate the mass removal mechanisms of cement-based materials under laser interactions, the effect of laser cutting was evaluated in terms of kerf width, penetration depth, and chemical composition changes before and after the interaction with laser using EDX analysis. The test results reveal that adding silica sand in cement-based materials leads to decreasing penetration depth and increasing kerf width. Unlike the cement paste and cement mortar series, UHPC specimens showed no discernible crack observed by the naked eye after laser interaction due to its high strength. Furthermore, the chemical analysis indicates that chemical composition changes were caused by various mechanisms including dehydration of calcium hydroxide and thermal decomposition of calcium carbonate.
Aortic root surgery: Early postoperative results of different surgical techniques
Authors: Benetis Rimantas , Ereminienė Eglė , Jakuška Povilas , Karčiauskas Dainius , Kinduris Šarūnas , Budrikis Algimantas , Siudikas Adakrius , Vaškelytė Jolanta , Sasnauskas Algimantas , Sakalauskas Juozas , Vaičiulis Kastytis
Published: June 2018

The aim of the study was to evaluate early postoperative results of different surgical techniques of aortic root surgery. Material and methods. Between January 2004 and November 2007, a cohort of 83 patients underwent aortic root surgery in the Heart Center, Hospital of Kaunas University of Medicine. Patients were divided into three groups: Group 1 (18 patients) – reimplantation of the aortic valve within a vascular graft (David operation), Group 2 (48 patients) – replacement of the ascending aorta and aortic valve using a valved conduit (Bentall de Bono operation), and Group 3 (17 patients) – biological aortic root replacement. Study protocol included clinical data, operative data, and postoperative major adverse effects: reoperations for bleeding, stroke and lethal outcomes. Results. Patients undergoing biological aortic root replacement were older as compared with other groups. The mean age in the Group 1 was 50.3±3.5 years vs. 57±2.0 years in the Group 2 and 67.8±3.3 years in the Group 3 (P<0.05). The main indication for the aortic root surgery was the aneurysm of the aortic root and ascending aorta in the Group 1 and 2 patients (64.7% and 72%), while in the Group 3, the main indication was fibrocalcinosis of aortic valve, aortic annulus, and ascending aorta (61.1%). The 30-day hospital mortality rates were as follows: 5.8% (n=1), in the Group 1; 10.4% (n=5), in the Group 2; 5.5% (n=1), in the Group 3. In the early postoperative period, 11 reoperations were performed due to bleeding events: in the Group 1, after planned/emergency surgery (n=2/2), and in the Group 2 (n=1/6), respectively. The function of aortic valve improved significantly in all groups of patients early after surgery. In the Group 1, the degree of aortic regurgitation decreased from 2.5±0.8 to 1.1±0.6 (P<0.05); in the Groups 2 and 3, the mean gradient through the aortic valve decreased from 39.9±7.5 to 17.1±5.3 mm Hg and from 48.8±18.0 to 20.1±11.0 mm Hg, respectively (P<0.05). No reoperation for aortic valve failure before the discharge was required in all groups of patients, and neither thromboembolic complications nor stroke events were noted in any group. Conclusions. Different aortic root surgery techniques showed similar postoperative results. New aortic root surgery methods such as aortic root-preserving/sparing procedures and concurrent aortic valve leaflet repair or aortic root replacement with the bioprosthesis can be selected for a diverse class of aortic root pathology with low perioperative mortality rates and good early postoperative results.
Qigong and a Tale of Two Back Complaints
Authors: Baumgarden Joseph , Klein Penelope , Picard George
Published: June 2018

Background: Chronic back pain is one of the leading causes of disability and decreased quality of life for people in both their personal and professional lives. In addition to modern medical intervention, many individuals seek relief through complementary and alternative therapies. Design: This study was designed as a retrospective descriptive review presented as two case studies. Methods: Data were collected through face-to-face interviews with two volunteer subjects of convenience who each had a medical diagnosis of chronic back pain. Intervention: Both individuals practiced a daily, standardized regimen of 24-Posture Qigong. Results: Both individuals experienced clinically significant symptomatic relief and functional benefit from their practice of qigong. Conclusion: Positive outcomes are theoretically attributed to relief of inflammation systemically and locally, reversal of sensitization and structural restorative reparation. These results provide justification for further prospective, controlled, long-term investigations.
Electrochemical Properties of Nb-Substituted Zr-Ti-Ni Hydrogen Storage Alloy Negative Electrodes for Nickel-Metal Hydride Batteries
Authors: Matsuyama Akihiro , Takito Hironori , Kozuka Takumi , Inoue Hiroshi
Published: June 2018

Crystal structure, pressure-composition isotherms and electrochemical properties of the Zr0.6−xTi0.4NbxNi (x = 0.01, 0.02, and 0.05) alloys were investigated. Their X-ray diffraction profiles demonstrated that all the Zr0.6−xTi0.4NbxNi alloys consisted of the primary phase with the B33-type orthorhombic structure and the secondary phase with the B2-type Ti0.6Zr0.4Ni cubic structure. Rietveld refinement demonstrated that the atomic fraction of the secondary phase increased with the Nb content. The Zr0.6−xTi0.4NbxNi alloys were lower in hydrogen storage capacity than the Nb-free Zr0.6Ti0.4Ni alloy due to an increase in the abundance of the secondary phase. In the charge-discharge tests with the Zr0.6−xTi0.4NbxNi alloy negative electrodes, all the initial discharge curves had two potential plateaus due to the electrochemical hydrogen desorption of trihydride to monohydride and monohydride to alloy of the primary phase. The total discharge capacities at 333 and 303 K for the Zr0.58Ti0.4Nb0.02Ni alloy negative electrode were 384 and 335 mAh g−1, respectively, which were higher than those of the other Zr0.6−xTi0.4NbxNi and Zr0.6Ti0.4Ni alloy negative electrodes.
Microstructure Evolution in Super Duplex Stainless Steels Containing σ-Phase Investigated at Low-Temperature Using In Situ SEM/EBSD Tensile Testing
Authors: Paulsen Christian Oen , Broks Runar Larsen , Karlsen Morten , Hjelen Jarle , Westermann Ida
Published: June 2018

An in situ scanning electron microscope (SEM) study was conducted on a super duplex stainless steel (SDSS) containing 0%, 5% and 10% σ-phase. The material was heat treated at 850 °C for 12 min and 15 min, respectively, to achieve the different amounts of σ-phase. The specimens were investigated at room temperature and at −40 °C. The microstructure evolution during the deformation process was recorded using electron backscatter diffraction (EBSD) at different strain levels. Both σ-phase and χ-phase were observed along the grain boundaries in the microstructure in all heat treated specimens. Cracks started to form after 3–4% strain and were always oriented perpendicular to the tensile direction. After the cracks formed, they were initially arrested by the matrix. At later stages of the deformation process, cracks in larger σ-phase constituents started to coalesce. When the tensile test was conducted at −40 °C, the ductility increased for the specimen without σ-phase, but with σ-phase present, the ductility was slightly reduced. With larger amounts of σ-phase present, however, an increase in tensile strength was also observed. With χ-phase present along the grain boundaries, a reduction of tensile strength was observed. This reduction seems to be related to χ-phase precipitating at the grain boundaries, creating imperfections, but not contributing towards the increase in strength. Compared to the effect of σ-phase, the low temperature is not as influential on the materials performance.
Local Monte Carlo Method for Fatigue Analysis of Coarse-Grained Metals with a Nanograined Surface Layer
Authors: Guo Xiang , Sun Qiuqiu , Yang Tao , Weng George J. , Zhang Cunbo , Feng Xiqiao
Published: June 2018

The fatigue resistance of coarse-grained (CG) metals can be greatly improved by introducing a nanograined surface layer. In this study, the Weibull distribution is used to characterize the spatially-random fracture properties of specimens under axial fatigue. For the cylindrical solid specimen, the heterogeneity of element sizes may lead to unfavorable size effects in fatigue damage initiation and evolution process. To alleviate the size effects, a three-dimensional cohesive finite element method combined with a local Monte Carlo simulation is proposed to analyze fatigue damage evolution of solid metallic specimens. The numerical results for the fatigue life and end displacement of CG specimens are consistent with the experimental data. It is shown that for the specimens after surface mechanical attrition treatment, damage initiates from the subsurface and then extends to the exterior surface, yielding an improvement in the fatigue life. Good agreement is found between the numerical results for the fatigue life of the specimens with the nanograined layer and experimental data, demonstrating the efficacy and accuracy of the proposed method.
3D-Printed Capillary Circuits for Calibration-Free Viscosity Measurement of Newtonian and Non-Newtonian Fluids
Authors: Oh Sein , Choi Sungyoung
Published: June 2018

Measuring viscosity is important for the quality assurance of liquid products, as well as for monitoring the viscosity of clinical fluids as a potential hemodynamic biomarker. However, conventional viscometers and their microfluidic counterparts typically rely on bulky and expensive equipment, and lack the ability for rapid and field-deployable viscosity analysis. To address these challenges, we describe 3D-printed capillary circuits (3D-CCs) for equipment- and calibration-free viscosity measurement of Newtonian and non-Newtonian fluids. A syringe, modified with an air chamber serving as a pressure buffer, generates and maintains a set pressure to drive the pressure-driven flows of test fluids through the 3D-CCs. The graduated fluidic chambers of the 3D-CCs serve as a flow meter, enabling simple measurement of the flow rates of the test fluids flowing through the 3D-CCs, which is readable with the naked eye. The viscosities of the test fluids can be simply calculated from the measured flow rates under a set pressure condition without the need for peripheral equipment and calibration. We demonstrate the multiplexing capability of the 3D-CC platform by simultaneously measuring different Newtonian-fluid samples. Further, we demonstrate that the shear-rate dependence of the viscosity of a non-Newtonian fluid can be analyzed simultaneously under various shear-rate conditions with the 3D-CC platform.
Design of Substrate Stretchability Using Origami-Like Folding Deformation for Flexible Thermoelectric Generator
Authors: Fukuie Kana , Iwata Yoshitaka , Iwase Eiji
Published: June 2018

A stretchable thermoelectric (TE) generator was developed by using rigid BiTe-based TE elements and a non-stretchable substrate with origami-like folding deformation. Our stretchable TE generator contains flat sections, on which the rigid TE elements are arranged, and folded sections, which produce and guarantee the stretchability of a device. First, a simple stretchable device with a single pair of p-type and n-type BiTe-based TE elements was designed and fabricated. The TE elements were sandwiched between two folded polyimide-copper substrates. The length of the wiring between the flat sections changed from 1.0 mm in the folded state to 1.8 mm in the deployed state. It was also confirmed that the single-pair device could generate power in both the folded and deployed states. After this, a stretchable TE generator with eight pairs of p-type and n-type BiTe-based TE elements connected in series was created. The stretchable TE generator was capable of withstanding a stretching deformation of 20% and could also produce an output voltage in both the folded and deployed states.
Erbium Luminescence Centres in Single- and Nano-Crystalline Diamond—Effects of Ion Implantation Fluence and Thermal Annealing
Authors: Cajzl Jakub , Nekvindová Pavla , Macková Anna , Malinský Petr , Oswald Jiří , Remeš Zdeněk , Varga Marián , Kromka Alexander , Akhetova Banu , Böttger Roman , Prajzler Václav
Published: June 2018

We present a fundamental study of the erbium luminescence centres in single- and nano-crystalline (NCD) diamonds. Both diamond forms were doped with Er using ion implantation with the energy of 190 keV at fluences up to 5 × 1015 ions·cm−2, followed by annealing at controllable temperature in Ar atmosphere or vacuum to enhance the near infrared photoluminescence. The Rutherford Backscattering Spectrometry showed that Er concentration maximum determined for NCD films is slightly shifted to the depth with respect to the Stopping and Range of Ions in Matter simulation. The number of the displaced atoms per depth slightly increased with the fluence, but in fact the maximum reached the fully disordered target even in the lowest ion fluence used. The post-implantation annealing at 800 °C in vacuum had a further beneficial effect on erbium luminescence intensity at around 1.5 μm, especially for the Er-doped NCD films, which contain a higher amount of grain boundaries than single-crystalline diamond.
Phenolic and Nonpolar Fractions of Elaeagnus rhamnoides (L.) A. Nelson Extracts as Virulence Modulators—In Vitro Study on Bacteria, Fungi, and Epithelial Cells
Authors: Różalska Barbara , Sadowska Beata , Żuchowski Jerzy , Więckowska-Szakiel Marzena , Budzyńska Aleksandra , Wójcik Urszula , Stochmal Anna
Published: June 2018

Butanol extracts from leaves, twigs, and fruits of Elaeagnus rhamnoides (L.) A. Nelson (sea buckthorn, SBT) were fractionated into phenolic and nonpolar lipid components, the chemical composition of which was analyzed. Assuming that an effect on natural microbiota and host epithelial cells needs to be assessed, regardless of the purpose of using SBT formulations in vivo, the minimal inhibitory/biocidal/fungicidal concentrations (MICs/MBCs/MFCs) of the fractions and reference phytocompounds were screened, involving 17 species of Gram-positive and Gram-negative bacteria and Candida species. The MICs of SBT extracts were in the range of 0.25–2.0 mg∙mL−1. Since direct antimicrobial activity of the extracts was quite low and variable, the impact of subMIC on the important in vivo persistence properties of model microorganisms S. aureus and C. albicans was evaluated. Tests for adhesion and biofilm formation on an abiotic surface and on surfaces conditioned with fibrinogen, collagen, plasma, or artificial saliva showed the inhibitory activity of the fractions. The effects on fluorescein isothiocyanate (FITC)-labeled staphylococci adhesion to fibroblasts (HFF-1) and epithelial cells (Caco-2), and on fungal morphogenesis, indicated that SBT extracts have high antivirulence potential. Cytotoxicity tests (MTT reduction) on the standard fibroblast cell line showed variable biological safety of the fractions depending on their composition and concentration. The new information afforded by this study, additional to that already known, is of potential practical value in the application of SBT-derived preparations as antivirulence agents.
Synthesis and Fungicidal Activity of Lansiumamide A and B and Their Derivatives
Authors: Xu Huiyou , Chen Ting , Huang Luanbin , Shen Qiuju , Lian Zengwei , Shi Yan , Ouyang Ming-An , Song Liyan
Published: June 2018

A efficient 2-step protocol has been applied for the synthesis of Lansiumamide B (N-methyl-N-cis-styryl-cinnamamide, 2) derivatives by various substitution on the amide nitrogen with alkyl, allyl, propargyl, benzyl or ester groups. The structures of nine new compounds were characterized by HRMS, 1H NMR, and 13C NMR spectra. These compounds were tested in vitro against 10 strains of phytopathogenic fungi and showed a wide antifungal spectrum. The relationship between different substituents on the amide nitrogen and antifungal activity of Lansiumamide B derivatives were compared and analyzed. The result indicates that the length and steric hindrance of N-substitution have a significant impact on biological activities. It is noteworthy that the methyl or ethyl substituent on the amide nitrogen is critical for the antifungal activities.
Chemical Profiling and Screening of the Marker Components in the Fruit of Cassia fistula by HPLC and UHPLC/LTQ-Orbitrap MSn with Chemometrics
Authors: Tan Jiawei , Zheng Mengcheng , Duan Susu , Zeng Yanling , Zhang Ziwei , Cui Qingyu , Zhang Jiamei , Hong Tingting , Bai Jie , Du Shouying
Published: June 2018

Cassia fistula L. which is known as “Golden Shower”, is used as an ornamental plant due to its flowers, and fruit parts of this plant have a high medicinal value. There are few reports providing a comprehensive overview of the chemical composition of its fruit or explaining the differences between samples from different sources because of the complexity of its chemical components. The purpose of the present study was to establish a fingerprint evaluation system based on Similarity Analysis (SA), Hierarchical Cluster Analysis (HCA) and Principal Component Analysis (PCA) for the composition identification and quality control of this herb. Twelve samples from Xinjiang and Sichuan provinces in China and India were analyzed by HPLC, and there were fifteen common peaks in the twelve batches. Molecular weight and formula information can be derived from thirty-one peaks by UHPLC/LTQ-Orbitrap MSn, molecular structure information of twenty components was obtained, of which ten compounds were identified by comparison with standard materials. Samples of twelve batches were divided according to their similarity into four groups, which were basically consistent with three different C.fistula fruit-producing areas. Five compounds were finally considered to be chemical markers to determine the quality of this herb. A fingerprints method combined with chemometrics was established to differentiate the origin of the fruit of C. fistula which has the advantages of effectivity and convenience, laying the foundation for the quality evaluation of this herb from different sources.
Bioactive Indanes: Proof of Concept Study for Enantioselective Synthetic Routes to PH46A, a New Potential Anti-Inflammatory Agent
Authors: Zhang Tao , Scalabrino Gaia , Frankish Neil , Sheridan Helen
Published: June 2018

PH46A is a single enantiomer and a member of the 1,2-indane dimer family. It has two contiguous stereogenic centers with S,S configurations, one of which being a quaternary center, which has been developed as a clinical candidate for the treatment of inflammatory and autoimmune conditions. The current synthetic route to PH46A involves the generation of an unwanted enantiomer (R,R)-7, thus reducing the final yield significantly. Therefore, we have investigated potential alternatives to improve the efficiency of this synthesis. The first phase of the study has demonstrated proof of principle for a chiral alkylation of ketone 3 using phase-transfer catalysis, providing a key intermediate ketone (S)-4. The parent alkaloids required for the synthesis of PH46A, quinine or cinchonidine, have also been identified. Promising enantiomeric excesses of up to 50% have been achieved to date, and the use of an alternative substrate, unsaturated ketone 9, has also opened up further avenues for optimisation in future studies. The second part of the study involved preliminary screening the effects of a panel of hydrolase enzymes on (rac)-4 in order to identify a potential chemo-enzymatic route to optimise the introduction of chirality into PH46A at early stage of the synthesis. The hydrolase module has also yielded positive results; enzyme AH-46 with MtBE providing a selectivity factor of 8.4 with enantiomeric excess of 77%. Overall, positive results were obtained in this proof of concept study described herein. It is believed that conditions of both chiral PTC alkylation and biocatalytic hydrolysis could be optimised to further enhance the selectivity and improve the overall yield. This work is currently ongoing.
(−)-Epicatechin Reduces Blood Pressure and Improves Left Ventricular Function and Compliance in Deoxycorticosterone Acetate-Salt Hypertensive Rats
Authors: Jackson Douglas , Connolly Kylie , Batacan Romeo , Ryan Kimberly , Vella Rebecca , Fenning Andrew
Published: June 2018

(−)-Epicatechin (E) is a flavanol found in green tea and cocoa and has been shown to attenuate tumour necrosis factor alpha (TNF-α)-mediated inflammation, improve nitric oxide levels, promote endothelial nitric oxide synthase (eNOS) activation and inhibit NADPH oxidase. This study investigated the effect of 28 days of low epicatechin dosing (1 mg/kg/day) on the cardiovascular function of deoxycorticosterone acetate (DOCA)-salt hypertensive rats. Wistar rats (n = 120, 8 weeks of age) underwent uninephrectomy and were randomised into four groups (uninephrectomy (UNX), UNX + E, DOCA, DOCA + E). DOCA and DOCA + E rats received 1% NaCl drinking water along with subcutaneous injections of 25 mg deoxycorticosterone-acetate (in 0.4 mL of dimethylformamide) every fourth day. UNX + E and DOCA + E rats received 1 mg/kg/day of epicatechin by oral gavage. Single-cell micro-electrode electrophysiology, Langendorff isolated-heart assessment and isolated aorta and mesenteric organ baths were used to assess cardiovascular parameters. Serum malondialdehyde concentration was used as a marker of oxidative stress. Myocardial stiffness was increased and left ventricular compliance significantly diminished in the DOCA control group, and these changes were attenuated by epicatechin treatment (p < 0.05). Additionally, the DOCA + E rats showed significantly reduced blood pressure and malondialdehyde concentrations; however, there was no improvement in left ventricular hypertrophy, electrophysiology or vascular function. This study demonstrates the ability of epicatechin to reduce blood pressure, prevent myocardial stiffening and preserve cardiac compliance in hypertrophied DOCA-salt rat hearts.
Synthesis of Porous CoFe2O4 and Its Application as a Peroxidase Mimetic for Colorimetric Detection of H2O2 and Organic Pollutant Degradation
Authors: Wu Lihong , Wan Gengping , Hu Na , He Zhengyi , Shi Shaohua , Suo Yourui , Wang Kan , Xu Xuefei , Tang Yulin , Wang Guizhen
Published: June 2018

Porous CoFe2O4 was prepared via a simple and controllable method to develop a low-cost, high-efficiency, and good-stability nanozyme. The morphology and microstructure of the obtained CoFe2O4 was investigated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), specific surface area and pore analysis, and Raman spectroscopy. The results show that the annealing temperature has an important effect on the crystallinity, grain size, and specific surface area of CoFe2O4. CoFe2O4 obtained at 300 °C (CF300) exhibits the largest surface area (up to 204.1 m2 g−1) and the smallest grain size. The peroxidase-like activity of CoFe2O4 was further verified based on the oxidation of peroxidase substrate 3,3’,5,5’-tetramethylbenzidine (TMB) in the presence of H2O2. The best peroxidase-like activity for CF300 should be ascribed to its largest surface area and smallest grain size. On this basis, an effective method of colorimetric detection H2O2 was established. In addition, the porous CoFe2O4 was also used for the catalytic oxidation of methylene blue (MB), indicating potential applications in pollutant removal and water treatment.
Nanomaterials in Liquid Crystals
Authors: Dierking Ingo
Published: June 2018

n/a
Effects of Sample Preparation on Particle Size Distributions of Different Types of Silica in Suspensions
Authors: Retamal Marín Rodrigo R. , Babick Frank , Lindner Gottlieb-Georg , Wiemann Martin , Stintz Michael
Published: June 2018

The granulometric characterization of synthetic amorphous silica (SAS) nanomaterials (NMs) still demands harmonized standard operation procedures. SAS is produced as either precipitated, fumed (pyrogenic), gel and colloidal SAS and these qualities differ, among others, with respect to their state of aggregation and aggregate strength. The reproducible production of suspensions from SAS, e.g., for biological testing purposes, demands a reasonable amount of dispersing energy. Using materials representative for each of the types of SAS, we employed ultrasonic dispersing (USD) at energy densities of 8–1440 J/mL and measured resulting particle sizes by dynamic light scattering and laser diffraction. In this energy range, USD had no significant impact on particle size distributions of colloidal and gel SAS, but clearly decreased the particle size of precipitated and fumed SAS. For high energy densities, we observed a considerable contamination of SAS suspensions with metal particles caused by abrasion of the sonotrode’s tip. To avoid this problem, the energy density was limited to 270 J/mL and remaining coarse particles were removed with size-selective filtration. The ultrasonic dispersion of SAS at medium levels of energy density is suggested as a reasonable compromise to produce SAS suspensions for toxicological in vitro testing.
Tailoring Bandgap of Perovskite BaTiO3 by Transition Metals Co-Doping for Visible-Light Photoelectrical Applications: A First-Principles Study
Authors: Yang Fan , Yang Liang , Ai Changzhi , Xie Pengcheng , Lin Shiwei , Wang Cai-Zhuang , Lu Xihong
Published: June 2018

The physical and chemical properties of V-M″ and Nb-M″ (M″ is 3d or 4d transition metal) co-doped BaTiO3 were studied by first-principles calculation based on density functional theory. Our calculation results show that V-M″ co-doping is more favorable than Nb-M″ co-doping in terms of narrowing the bandgap and increasing the visible-light absorption. In pure BaTiO3, the bandgap depends on the energy levels of the Ti 3d and O 2p states. The appropriate co-doping can effectively manipulate the bandgap by introducing new energy levels interacting with those of the pure BaTiO3. The optimal co-doping effect comes from the V-Cr co-doping system, which not only has smaller impurity formation energy, but also significantly reduces the bandgap. Detailed analysis of the density of states, band structure, and charge-density distribution in the doping systems demonstrates the synergistic effect induced by the V and Cr co-doping. The results can provide not only useful insights into the understanding of the bandgap engineering by element doping, but also beneficial guidance to the experimental study of BaTiO3 for visible-light photoelectrical applications.
Protein-Based Fiber Materials in Medicine: A Review
Authors: DeFrates Kelsey G. , Moore Robert , Borgesi Julia , Lin Guowei , Mulderig Thomas , Beachley Vince , Hu Xiao
Published: June 2018

Fibrous materials have garnered much interest in the field of biomedical engineering due to their high surface-area-to-volume ratio, porosity, and tunability. Specifically, in the field of tissue engineering, fiber meshes have been used to create biomimetic nanostructures that allow for cell attachment, migration, and proliferation, to promote tissue regeneration and wound healing, as well as controllable drug delivery. In addition to the properties of conventional, synthetic polymer fibers, fibers made from natural polymers, such as proteins, can exhibit enhanced biocompatibility, bioactivity, and biodegradability. Of these proteins, keratin, collagen, silk, elastin, zein, and soy are some the most common used in fiber fabrication. The specific capabilities of these materials have been shown to vary based on their physical properties, as well as their fabrication method. To date, such fabrication methods include electrospinning, wet/dry jet spinning, dry spinning, centrifugal spinning, solution blowing, self-assembly, phase separation, and drawing. This review serves to provide a basic knowledge of these commonly utilized proteins and methods, as well as the fabricated fibers’ applications in biomedical research.
Formation of Slantwise Surface Ripples by Femtosecond Laser Irradiation
Authors: Zheng Xin , Cong Cong , Lei Yuhao , Yang Jianjun , Guo Chunlei
Published: June 2018

We report on the formation of slantwise-oriented periodic subwavelength ripple structures on chromium surfaces irradiated by single-beam femtosecond laser pulses at normal incidence. Unexpectedly, the ripples slanted in opposite directions on each side the laser-scanned area, neither perpendicular nor parallel to the laser polarization. The modulation depth was also found to change from one ripple to the next ripple. A theoretical model is provided to explain our observations, and excellent agreement is shown between the simulations and the experimental results. Moreover, the validity of our theory is also confirmed on bulk chromium surfaces. Our study provides insights for better understanding and control of femtosecond laser nanostructuring.
Anti-Fatigue Effects of Yogurt Fermented with Lactobacillus delbrueckii subsp. bulgaricus OLL1073R-1 in Healthy People Suffering from Summer Heat Fatigue: A Randomized, Double-Blind, Placebo-Controlled Trial
Authors: Makino Seiya , Hemmi Jun , Kano Hiroshi , Kashiwagi Mari , Hojo Kenichi , Asami Yukio
Published: June 2018

Fatigue caused by summer heat is a typical indefinite complaint along with anorexia, loss of sleep, stress, lack of motivation and, in some cases, catching a cold. Yogurt fermented with Lactobacillus delbrueckii subsp. bulgaricus OLL1073R-1 has been shown to stimulate the immune system and reduce the risk of catching colds. Here, we conducted a randomized, double-blinded, placebo-controlled trial to investigate whether ingesting this yogurt could ameliorate summer heat fatigue in 49 healthy males (median age 40.0 ± 6.0 years; 30–49 years) who felt fatigued every summer. Fatigue was evaluated by visual analogue scales (VAS) and the balance of sympathetic/parasympathetic nervous systems. After 12 weeks of ingestion in early autumn, the VAS fatigue scores in the yogurt group were lower than those of the placebo group. These results indicate that yogurt fermented with L. bulgaricus OLL1073R-1 can ameliorate summer heat fatigue lasting up to early autumn.
The Effects of Quassinoid-Rich Eurycoma longifolia Extract on Bone Turnover and Histomorphometry Indices in the Androgen-Deficient Osteoporosis Rat Model
Authors: Jayusman Putri Ayu , Mohamed Isa Naina , Alias Ekram , Mohamed Norazlina , Shuid Ahmad Nazrun
Published: June 2018

Male osteoporosis is associated with higher rates of disability and mortality. Hence the search for suitable intervention and treatment to prevent the degeneration of skeletal health in men is necessary. Eurycoma longifolia (EL), a traditional plant with aphrodisiac potential may be used to treat and prevent male osteoporosis. The skeletal protective effect of quassinoid-rich EL extract, which has a high content of eurycomanone, has not been studied. This study aimed to determine whether EL could prevent skeletal deteriorations in gonadal hormone-deficient male rats. Ninety-six male Sprague–Dawley rats were randomly assigned to baseline, sham-operated (Sham), orchidectomised or chemically castrated groups. Chemical castration was achieved via subcutaneous injection of degarelix at 2 mg/kg. The orchidectomised and degarelix-castrated rats were then divided into negative control groups (ORX, DGX), testosterone-treated groups (intramuscular injection at 7 mg/kg weekly) (ORX + TES, DGX + TES), and EL-supplemented groups receiving daily oral gavages at doses of 25 mg/kg (ORX + EL25, DGX + EL25), 50 mg/kg (ORX + EL50, DGX + EL50), and 100 mg/kg (ORX + EL100, DGX + EL100). Following 10 weeks of treatment, the rats were euthanized and their blood and femora were collected. Bone biochemical markers, serum testosterone, osteoprotegerin (OPG), and receptor activator of nuclear factor kappa β-ligand (RANKL) levels and histomorphometric indices were evaluated. Quassinoid-rich EL supplementation was found to reduce degenerative changes of trabecular structure by improving bone volume, trabecular number, and separation. A reduction in the percentage of osteoclast and increase in percentage of osteoblast on bone surface were also seen with EL supplementation. Dynamic histomorphometric analysis showed that the single-labeled surface was significantly decreased while the double-labeled surface was significantly increased with EL supplementations. There was a marginal but significant increase in serum testosterone levels in the ORX + EL25, DGX + EL50, and DGX + EL100 groups compared to their negative control groups. Quassinoid-rich EL extract was effective in reducing skeletal deteriorations in the androgen-deficient osteoporosis rat model.
Cutaneous and Mucosal Manifestations Associated with Celiac Disease
Authors: Rodrigo Luis , Beteta-Gorriti Valia , Alvarez Nuria , Gómez de Castro Celia , De Dios Alvaro , Palacios Laura , Santos-Juanes Jorge
Published: June 2018

Celiac disease (CD) is an immune-mediated, gluten-induced enteropathy that affects predisposed individuals of all ages. Many patients with CD do not report gastrointestinal symptoms making it difficult to reach an early diagnosis. On the other hand, CD is related to a wide spectrum of extra-intestinal manifestations, with dermatitis herpetiformis (DH) being the best characterized. These associated conditions may be the clue to reaching the diagnosis of CD. Over the last few years, there have been multiple reports of the association between CD and several cutaneous manifestations that may improve with a gluten-free diet (GFD). The presence of some of these skin diseases, even in the absence of gastrointestinal symptoms, should give rise to an appropriate screening method for CD. The aim of this paper is to describe the different cutaneous manifestations that have been associated with CD and the possible mechanisms involved.
Effects of Fish Oil on Lipid Metabolism and Its Molecular Biological Regulators in Chronic Ethanol-Fed Rats
Authors: Wang Hsiao-Yun , Peng Hsiang-Chi , Chien Yi-Wen , Chen Ya-Ling , Lu Nien-Shan , Yang Suh-Ching
Published: June 2018

The purpose of this study was to clarify the hepatoprotective mechanisms of fish oil in ethanol-fed rats based on lipid metabolism. Thirty eight-week-old male Wistar rats were divided into six groups: C (control), CF25 (control diet with 25% fish oil substitution), CF57 (control diet with 57% fish oil substitution), E (ethanol-containing diet) group, EF25 (ethanol-containing diet with 25% fish oil substitution), and EF57 (ethanol-containing diet with 57% fish oil substitution) groups. All of the groups were pair-fed an isoenergetic diet based on E group. Rats were sacrificed after eight weeks. When compared with C group, the plasma aspartate transaminase (AST) activity and hepatic steatosis and inflammatory cell infiltration were significantly higher, while plasma adiponectin level and hepatic AMP-activated protein kinase α (AMPKα) protein expression was significantly lower in the E group. However, the hepatic damage, including steatosis and inflammation were ameliorated in the EF25 and EF57 groups. Moreover, mRNA levels of fatty acid-oxidative enzymes, such as medium-chain acyl-coenzyme A dehydrogenase (MCAD) and carnitine palmitoyltransferase I (CPT-1) were significantly elevated in the EF57 group than those in E group. Partial replacement with fish oil might improve the fatty acid oxidation by raising mRNA levels of downstream transcription factors, finally inhibit the ethanol-induced hepatic steatosis in rats.
Assessment of the Canadian Children’s Food and Beverage Advertising Initiative’s Uniform Nutrition Criteria for Restricting Children’s Food and Beverage Marketing in Canada
Authors: Mulligan Christine , Labonté Marie-Ève , Vergeer Laura , L’Abbé Mary R.
Published: June 2018

Imposing governmental restrictions on the marketing of unhealthy foods and beverages to children is a demanded policy action since in Canada, this remains self-regulated by the voluntary, industry-led Canadian Children’s Food and Beverage Advertising Initiative (CAI) whose participants pledge to only advertise products that satisfy its Uniform Nutrition Criteria to children. This study evaluated the stringency of this nutrient profiling (NP) model for restricting child-directed food and beverage marketing in Canada. Data was obtained from the University of Toronto Food Label Information Program (FLIP) 2013 database, providing nutritional information for 15,342 packaged products which were evaluated using the CAI Uniform Nutrition Criteria. Products with child-directed packaging and those from CAI participating companies were identified. Of the n = 15,231 products analyzed, 25.3% would be allowed and 57.2% would be restricted from being marketed to children according to the CAI Criteria. Additionally, 17.5% of products lacked criteria by which to evaluate them. Child-directed products represented 4.9% of all products; however, 74.4% of these would be restricted from being marketed to children under CAI standards. Products from CAI participating companies represented 14.0% of all products and 33.3% of child-directed products; 69.5% of which would be restricted from being marketed to children. These results indicate that if the CAI was mandatory and covered a broader range of advertising platforms, their Uniform Nutrition Criteria would be relatively stringent and could effectively restrict children’s marketing in Canada.
Shanxi Aged Vinegar Protects against Alcohol-Induced Liver Injury via Activating Nrf2-Mediated Antioxidant and Inhibiting TLR4-Induced Inflammatory Response
Authors: Xia Ting , Zhang Jin , Yao Jiahui , Zhang Bo , Duan Wenhui , Zhao Chaoya , Du Peng , Song Jia , Zheng Yu , Wang Min
Published: June 2018

Shanxi aged vinegar (SAV) is a typical fermented and antioxidant food, which has various health-promoting effects. This work aimed to explore the effects of SAV on alcohol-induced liver injury. A mice model of alcoholic liver injury was established to illuminate its potential mechanisms. All mice pretreated with SAV and then received an ethanol solution (50% w/v, 4.8 g/kg b.w.). The results showed that SAV ameliorated alcohol-induced histological changes and elevation of liver enzymes. SAV attenuated alcohol-induced oxidative stress by declining levels of hepatic oxidants, and restoring depletion of antioxidant enzyme activities in mice livers. Moreover, SAV alleviated alcohol-induced oxidative damage by activating nuclear factor erythroid-2-related factor 2 (Nrf2)-mediated signal pathway. In addition, SAV prevented alcohol-induced inflammation by suppressing lipopolysaccharide (LPS) level and activities of pro-inflammatory enzymes, and regulating inflammatory cytokines. SAV inhibited alcohol-induced inflammation through down-regulating the expression of Toll-like receptor 4 (TLR4)-mediated inflammatory response. The findings provide crucial evidence for elucidating the hepatoprotective mechanisms of SAV and encourage the future application of SAV as a functional food for liver protection.
The Mammalian Intestinal Microbiome: Composition, Interaction with the Immune System, Significance for Vaccine Efficacy, and Potential for Disease Therapy
Authors: Desselberger Ulrich
Published: June 2018

The mammalian gut is colonized by a large variety of microbes, collectively termed ‘the microbiome’. The gut microbiome undergoes rapid changes during the first few years of life and is highly variable in adulthood depending on various factors. With the gut being the largest organ of immune responses, the composition of the microbiome of the gut has been found to be correlated with qualitative and quantitative differences of mucosal and systemic immune responses. Animal models have been very useful to unravel the relationship between gut microbiome and immune responses and for the understanding of variations of immune responses to vaccination in different childhood populations. However, the molecular mechanisms underlying optimal immune responses to infection or vaccination are not fully understood. The gut virome and gut bacteria can interact, with bacteria facilitating viral infectivity by different mechanisms. Some gut bacteria, which have a beneficial effect on increasing immune responses or by overgrowing intestinal pathogens, are considered to act as probiotics and can be used for therapeutic purposes (as in the case of fecal microbiome transplantation).
Proximal Pathway Enrichment Analysis for Targeting Comorbid Diseases via Network Endopharmacology
Authors: Aguirre-Plans Joaquim , Piñero Janet , Menche Jörg , Sanz Ferran , Furlong Laura I. , Schmidt Harald H. H. W. , Oliva Baldo , Guney Emre
Published: June 2018

The past decades have witnessed a paradigm shift from the traditional drug discovery shaped around the idea of “one target, one disease” to polypharmacology (multiple targets, one disease). Given the lack of clear-cut boundaries across disease (endo)phenotypes and genetic heterogeneity across patients, a natural extension to the current polypharmacology paradigm is to target common biological pathways involved in diseases via endopharmacology (multiple targets, multiple diseases). In this study, we present proximal pathway enrichment analysis (PxEA) for pinpointing drugs that target common disease pathways towards network endopharmacology. PxEA uses the topology information of the network of interactions between disease genes, pathway genes, drug targets and other proteins to rank drugs by their interactome-based proximity to pathways shared across multiple diseases, providing unprecedented drug repurposing opportunities. Using PxEA, we show that many drugs indicated for autoimmune disorders are not necessarily specific to the condition of interest, but rather target the common biological pathways across these diseases. Finally, we provide high scoring drug repurposing candidates that can target common mechanisms involved in type 2 diabetes and Alzheimer’s disease, two conditions that have recently gained attention due to the increased comorbidity among patients.
In Silico Structural Evaluation of Short Cationic Antimicrobial Peptides
Authors: Passarini Ilaria , Rossiter Sharon , Malkinson John , Zloh Mire
Published: June 2018

Cationic peptides with antimicrobial properties are ubiquitous in nature and have been studied for many years in an attempt to design novel antibiotics. However, very few molecules are used in the clinic so far, sometimes due to their complexity but, mostly, as a consequence of the unfavorable pharmacokinetic profile associated with peptides. The aim of this work is to investigate cationic peptides in order to identify common structural features which could be useful for the design of small peptides or peptido-mimetics with improved drug-like properties and activity against Gram negative bacteria. Two sets of cationic peptides (AMPs) with known antimicrobial activity have been investigated. The first reference set comprised molecules with experimentally-known conformations available in the protein databank (PDB), and the second one was composed of short peptides active against Gram negative bacteria but with no significant structural information available. The predicted structures of the peptides from the first set were in excellent agreement with those experimentally-observed, which allowed analysis of the structural features of the second group using computationally-derived conformations. The peptide conformations, either experimentally available or predicted, were clustered in an “all vs. all” fashion and the most populated clusters were then analyzed. It was confirmed that these peptides tend to assume an amphipathic conformation regardless of the environment. It was also observed that positively-charged amino acid residues can often be found next to aromatic residues. Finally, a protocol was evaluated for the investigation of the behavior of short cationic peptides in the presence of a membrane-like environment such as dodecylphosphocholine (DPC) micelles. The results presented herein introduce a promising approach to inform the design of novel short peptides with a potential antimicrobial activity.
Molecular Dynamics Simulations on the Thermal Decomposition of Meta-Aramid Fibers
Authors: Yin Fei , Tang Chao , Wang Qian , Liu Xiong , Tang Yujing
Published: June 2018

The thermal decomposition mechanism of a meta-aramid fiber was simulated at the atomic level using the ReaxFF reactive force field. The simulation results indicated that the main initial decomposition positions of the meta-aramid fiber elements were Caromatic ring–N and C=O, which could be used as targets for the modification of meta-aramid fibers. The meta-aramid fiber elements first decomposed into C6–C13 and then into smaller segments and micromolecular gases. The temperature was shown to be the key factor affecting the thermal decomposition of the meta-aramid fibers. More complex compositions and stable gases were produced at high temperatures than at lower temperatures. HCN was a decomposition product at high temperature, suggesting that its presence could be used for detecting thermal faults in meta-aramid fibers. Generation path tracing of the thermal decomposition products NH3 and H2O was also performed. NH3 was produced when the NH2 group captured an H atom adjacent to the system. H2O was formed after a carbonyl group captured an H atom, became a hydroxyl group, with subsequent intramolecular dehydration or intermolecular hydrogen abstraction.
High Thermal Conductivity of Flake Graphite Reinforced Polyethylene Composites Fabricated by the Powder Mixing Method and the Melt-Extruding Process
Authors: Liu Zhichun , Tu Runchun , Liao Quanwen , Hu Hanlin , Yang Jinguo , He Yan , Bian Huiguang , Ma Lianxiang , Liu Wei
Published: June 2018

The thermal conductivity of flake graphite (FG) particulates reinforced high density polyethylene (HDPE) composites was systematically investigated under a special dispersion state of FG particles. The effects of particle size, weight filling ratio and proportion of various sizes were discussed in detail. A special composite (15 wt % 500 μm/10 wt % 200 μm/10 wt % 20 μm/5 wt % 2 μm FG + 60 wt % polyethylene (PE)) with a high thermal conductivity about 2.49 W/(m·K) was produced by combining the synergistic effect of several fillers. The component material size distribution was employed to analyze the effect of particle size. And scanning electron microscope (SEM) was adopted to observe the FG network in the composites. Thermogravimetric analysis (TGA) revealed the good thermal stability of composites. Differential scanning calorimetry (DSC) indicated that all composites own a similar melting temperature. Sample compression experiment indicated that all composites still exhibit high mechanical strength. Consequently, the easy-making flake graphite reinforced polyethylene composites with a high thermal conductivity would have a wide application in the new material field, such as a thermal interface material, a heat exchanger, voltage cable, etc.