bluuebunny/crossref_metadata_2025 huggingface dataset:
3D Multi-Branched SnO2 Semiconductor Nanostructures as Optical Waveguides
Authors: Rossella Francesco , Bellani Vittorio , Tommasini Matteo , Gianazza Ugo , Comini Elisabetta , Soldano Caterina
Published: September 2019

Nanostructures with complex geometry have gathered interest recently due to some unusual and exotic properties associated with both their shape and material. 3D multi-branched SnO2 one-dimensional nanostructrures, characterized by a “node”—i.e., the location where two or more branches originate, are the ideal platform to distribute signals of different natures. In this work, we study how this particular geometrical configuration affects light propagation when a light source (i.e., laser) is focused onto it. Combining scanning electron microscopy (SEM) and optical analysis along with Raman and Rayleigh scattering upon illumination, we were able to understand, in more detail, the mechanism behind the light-coupling occurring at the node. Our experimental findings show that multi-branched semiconductor 1D structures have great potential as optically active nanostructures with waveguiding properties, thus paving the way for their application as novel building blocks for optical communication networks.
Modeling Shrinkage and Creep for Concrete with Graphene Oxide Nanosheets
Authors: Chen Zengshun , Xu Yemeng , Hua Jianmin , Zhou Xiao , Wang Xu , Huang Lepeng
Published: September 2019

In this study, the shrinkage and creep of concrete containing graphene oxide (GO) nanosheets were experimentally and theoretically investigated. Experiments for the shrinkage and creep of concrete with 0.02% and 0.08% GO nanosheets by the weight of cement and common concrete were carried out. Subsequently, the influence of GO nanosheets on the shrinkage and creep of concrete was analyzed and discussed. A modified model was developed to accurately predict the shrinkage and creep of concrete containing GO nanosheets after models for predicting shrinkage and creep of common concrete were compared and the influential factors and application scope were determined. Results indicate that: (1) GO nanosheets can increase the shrinkage strain and reduce the creep coefficient of concrete, and (2) a modified ACI209 (92) model can accurately predict the shrinkage and creep of concrete containing GO nanosheets. Factors considering concrete strength can be introduced in the model to improve the model accuracy.
Elimination of Unwanted Modes in Wavelength-Selective Uncooled Infrared Sensors with Plasmonic Metamaterial Absorbers using a Subtraction Operation
Authors: Ogawa Shinpei , Takagawa Yousuke , Kimata Masafumi
Published: September 2019

Wavelength- or polarization-selective uncooled infrared (IR) sensors have various applications, such as in fire detection, gas analysis, hazardous material recognition, biological analysis, and polarimetric imaging. The unwanted modes originating due to the absorption by the materials used in these sensors, other than plasmonic metamaterial absorbers (PMAs), cause serious issues by degenerating the wavelength or polarization selectivity. In this study, we demonstrate a method for eliminating these unwanted modes in wavelength- or polarization-selective uncooled IR sensors with various PMAs, using a subtraction operation and a reference pixel. The aforementioned sensors and the reference pixels were fabricated using a complementary metal oxide semiconductor and micromachining techniques. We fabricated the reference pixel with the same structure as the PMA sensors, except a flat mirror was formed on the absorber surface instead of PMAs. The spectral responsivity measurements demonstrated that single-mode detection can be achieved through the subtraction operation with the reference pixel. The method demonstrated in this study can be applied to any type of uncooled IR sensors to create high-performance wavelength- or polarization-selective absorbers capable of multispectral or polarimetric detection.
Mechanical Properties and Fire Resistance of Magnesium-Cemented Poplar Particleboard
Authors: Zheng Nihua , Wu Danni , Sun Ping , Liu Hongguang , Luo Bin , Li Li
Published: September 2019

Magnesium-cemented poplar particleboard (MCPB) is a new environmental inorganic magnesium cementitious composite without formaldehyde release. In this study, soybean flour (SM), silane coupling agent (KH560), soybean protein isolate (SPI), polyethylene glycol (PEG-400), maleic anhydride (MAH), and polyacrylic acid (PAA) were added to MCPB to improve the mechanical properties, waterproofing properties, and flame retardancy. The results show that the SPI group had the best mechanical performance; the modulus of elasticity (MOE) was up to 5192 MPa and exceeded the Chinese national standard GBT 4897-2015 (GBT) by 67.4%, the modulus of rupture (MOR) reached 17.72 MPa and exceeded GBT by 18%. Thickness swelling (TS) after 24-hour immersion was 0.29% and reached the standard of GBT (≤16%). The fire resistance test of MCPB indicated that the KH560 group improved the flame retardancy, the heat release rate (HRR) was 18kW/m2, the total smoke produced (TSP) was 0.192 m2, the total heat release (THR) was 29.71 MJ/kg, which reached the Chinese national standard GBT 8624-2012.
Co-Immobilization of Glucose Dehydrogenase and Xylose Dehydrogenase as a New Approach for Simultaneous Production of Gluconic and Xylonic Acid
Authors: Zdarta Jakub , Bachosz Karolina , Degórska Oliwia , Zdarta Agata , Kaczorek Ewa , Pinelo Manuel , Meyer Anne S. , Jesionowski Teofil
Published: September 2019

The conversion of biomass components catalyzed via immobilized enzymes is a promising way of obtaining valuable compounds with high efficiency under mild conditions. However, simultaneous transformation of glucose and xylose into gluconic acid and xylonic acid, respectively, is an overlooked research area. Therefore, in this work we have undertaken a study focused on the co-immobilization of glucose dehydrogenase (GDH, EC 1.1.1.118) and xylose dehydrogenase (XDH, EC 1.1.1.175) using mesoporous Santa Barbara Amorphous silica (SBA 15) for the simultaneous production of gluconic acid and xylonic acid. The effective co-immobilization of enzymes onto the surface and into the pores of the silica support was confirmed. A GDH:XDH ratio equal to 1:5 was the most suitable for the conversion of xylose and glucose, as the reaction yield reached over 90% for both monosaccharides after 45 min of the process. Upon co-immobilization, reaction yields exceeding 80% were noticed over wide pH (7–9) and temperature (40–60 °C) ranges. Additionally, the co-immobilized GDH and XDH exhibited a significant enhancement of their thermal, chemical and storage stability. Furthermore, the co-immobilized enzymes are characterized by good reusability, as they facilitated the reaction yields by over 80%, even after 5 consecutive reaction steps.
Biofunctionalization with a TGFβ-1 Inhibitor Peptide in the Osseointegration of Synthetic Bone Grafts: An In Vivo Study in Beagle Dogs
Authors: Cirera Andrea , Manzanares Maria Cristina , Sevilla Pablo , Ortiz-Hernandez Monica , Galindo-Moreno Pablo , Gil Javier
Published: September 2019

Objectives: The aim of this research was to determine the osseointegration of two presentations of biphasic calcium phosphate (BCP) biomaterial—one untreated and another submitted to biofunctionalization with a TGF-β1 inhibitor peptide, P144, on dental alveolus. Materials and Methods: A synthetic bone graft was used, namely, (i) Maxresorb® (Botiss Klockner) (n = 12), and (ii) Maxresorb® (Botiss Klockner) biofunctionalized with P144 peptide (n = 12). Both bone grafts were implanted in the two hemimandibles of six beagle dogs in the same surgical time, immediately after tooth extraction. Two dogs were sacrificed 2, 4, and 8 weeks post implant insertion, respectively. The samples were submitted to histomorphometrical and histological analyses. For each sample, we quantified the new bone growth and the new bone formed around the biomaterial’s granules. After optical microscopic histological evaluation, selected samples were studied using backscattered scanning electron microscopy (BS-SEM). Results: The biofunctionalization of the biomaterial’s granules maintains a stable membranous bone formation throughout the experiment timeline, benefitting from the constant presence of vascular structures in the alveolar space, in a more active manner that in the control samples. Better results in the experimental groups were proven both by quantitative and qualitative analysis. Conclusions: Synthetic bone graft biofunctionalization results in slightly better quantitative parameters of the implant’s osseointegration. The qualitative histological and ultramicroscopic analysis shows that biofunctionalization may shorten the healing period of dental biomaterials.
Experimental and Numerical Investigation of Deformable Concrete Median Barrier
Authors: Lee Jaeha , Jeong Yoseok , Kim Kyeongjin , Lee Ilkeun , Kim WooSeok
Published: September 2019

In South Korea, the number of vehicles is gradually increasing. The number of heavy vehicles in 2010 increased up to 19% in less than five years. Therefore, the chances of heavy vehicle-concrete median barrier (CMB) collision also became higher than in the past; therefore, a need to study a stricter design level for improving the current CMB (CMB-15) under harsher environments arose. Accordingly, in the present study, a new concrete median barrier was designed under a stricter impact severity, SB6(420 kJ), compared to the current design impact severity, SB5-B (270 kJ). In particular, shock absorbing devices to absorb impact energy were applied to the CMB. An empty space allows the dowel bars to deform and absorb collision energy. Therefore, deformable CMB was designed and tested. The key parameters selected in our study were dowel bar and wire-mesh. A series of numerical analyses were conducted to evaluate the proposed new deformable CMB designs with shock absorbers. Finally, the optimal design, CMB-17S, was proposed after several evaluations of the proposed designs and a full-scale field test. It was found that, although the developed model did not accurately predict the impact sequence due to certain differences between the actual truck and the truck model, the permanent deformation after collision could be well predicted. Based on the observations from a full-scale impact test, it was recommended that the top part of the CMB should be strengthened since major volume loss occurred due to local impact, which appeared to be due to punching shear failure.
Influence of Process Parameters on the Porosity, Accuracy, Roughness, and Support Structures of Hastelloy X Produced by Laser Powder Bed Fusion
Authors: Calignano Flaviana , Minetola Paolo
Published: September 2019

The manufacture of highly complex components from nickel-based superalloys with laser powder bed fusion (L-PBF) technology can reduce the production costs parts with comparable microstructural and mechanical properties when compared to casting. The purpose of this study was to investigate the characteristics of samples produced in commercial Hastelloy X (with w% composition of 21Cr-18Fe-9Mo-0.7W-1.5Co-0.1C-1Si-1Mn-0.5Al-0.15Ti-bal.Ni) with an L-PBF process in terms of build density, accuracy, surface roughness, and interface area between the part and the support structures. Samples were obtained with a high density (99.88%), without cracks and with low surface roughness. From the analysis of the support structures, it emerged that the choice of the parameters between support structures, the lower face of the part (down-skin) and the internal area of the part (in-skin) is fundamental to the correct realization of these structures in order to avoid deformation of the components that is induced by thermal stresses during part building.
Time-Truncated Group Plan under a Weibull Distribution based on Neutrosophic Statistics
Authors: Aslam Muhammad , Jeyadurga P. , Balamurali Saminathan , AL-Marshadi Ali Hussein
Published: September 2019

The aim of reducing the inspection cost and time using acceptance sampling can be achieved by utilizing the features of allocating more than one sample item to a single tester. Therefore, group acceptance sampling plans are occupying an important place in the literature because they have the above-mentioned facility. In this paper, the designing of a group acceptance sampling plan is considered to provide assurance on the product’s mean life. We design the proposed plan based on neutrosophic statistics under the assumption that the product’s lifetime follows a Weibull distribution. We determine the optimal parameters using two specified points on the operating characteristic curve. The discussion on how to implement the proposed plan is provided by an illustrative example.
Optimal Multiple Attribute Decision Model for Key Parameters of Online Group Buying Product
Authors: Wang Shen-Tsu , Li Meng-Hua , Lien Chun-Chi
Published: September 2019

The rise of the internet has led to rapid development of online group buying, and with the various functions and analysis tools provided on the internet, consumers are making more purchases than ever before. In addition to attracting consumers to buy products or services via online shopping platforms, the industry’s online group buying market allows customers to enjoy preferential prices together. Consumers can bargain through large-scale purchases. Through quantity-based pricing, the effect of the decline on consumers’ expected price will be enhanced, and consumers will be able to purchase products at lower prices, which encourages more consumers to join group buying schemes. In terms of product cost, online shopping operations enable manufacturers to save shop setup and inventory costs, and some of these cost savings may be reflected in the selling price, which can enable customers to obtain products at lower prices. The grey decision model is used for further in-depth exploration. The purpose of this study is to use the grey correlation ranking and grey multi-attribute decision-making (TOPSIS) process to further determine the optimal shelf-time, inventory quantity, and selling price (key parameters) of commodities, in order to design a plan that makes maximum profit for the industry and provides the best service to customers.
Marine Natural Products and Drug Resistance in Latent Tuberculosis
Authors: Khan Muhammad Tahir , Kaushik Aman Chandra , Bhatti Aamer Iqbal , Zhang Yu-Juan , Zhang Shulin , Wei Amie Jinghua , Malik Shaukat Iqbal , Wei Dong Qing
Published: September 2019

Pyrazinamide (PZA) is the only drug for the elimination of latent Mycobacterium tuberculosis (MTB) isolates. However, due to the increased number of PZA-resistance, the chances of the success of global TB elimination seems to be more prolonged. Recently, marine natural products (MNPs) as an anti-TB agent have received much attention, where some compounds extracted from marine sponge, Haliclona sp. exhibited strong activity under aerobic and hypoxic conditions. In this study, we screened articles from 1994 to 2019 related to marine natural products (MNPs) active against latent MTB isolates. The literature was also mined for the major regulators to map them in the form of a pathway under the dormant stage. Five compounds were found to be more suitable that may be applied as an alternative to PZA for the better management of resistance under latent stage. However, the mechanism of actions behind these compounds is largely unknown. Here, we also applied synthetic biology to analyze the major regulatory pathway under latent TB that might be used for the screening of selective inhibitors among marine natural products (MNPs). We identified key regulators of MTB under latent TB through extensive literature mining and mapped them in the form of regulatory pathway, where SigH is negatively regulated by RshA. PknB, RshA, SigH, and RNA polymerase (RNA-pol) are the major regulators involved in MTB survival under latent stage. Further studies are needed to screen MNPs active against the main regulators of dormant MTB isolates. To reduce the PZA resistance burden, understanding the regulatory pathways may help in selective targets of MNPs from marine natural sources.
Asperienes A–D, Bioactive Sesquiterpenes from the Marine-Derived Fungus Aspergillus flavus
Authors: Liu Yun-Feng , Yue Yu-Fei , Feng Li-Xi , Zhu Hua-Jie , Cao Fei
Published: September 2019

Marine-derived fungi of the genera Aspergillus could produce novel compounds with significant bioactivities. Among these fungi, the strain Aspergillus flavus is notorious for its mutagenic mycotoxins production. However, some minor components with certain toxicities from A. flavus have not been specifically surveyed and might have potent biological activities. Our investigation of the marine-derived fungus Aspergillus flavus CF13-11 cultured in solid medium led to the isolation of four C-6′/C-7′ epimeric drimane sesquiterpene esters, asperienes A–D (1–4). Their absolute configurations were assigned by electronic circular dichroism (ECD) and Snatzke’s methods. This is the first time that two pairs of C-6′/C-7′ epimeric drimane sesquiterpene esters have successfully been separated. Aperienes A–D (1–4) displayed potent bioactivities towards four cell lines with the IC50 values ranging from 1.4 to 8.3 μM. Interestingly, compounds 1 and 4 exhibited lower toxicities than 2 and 3 toward normal GES-1 cells, indicating more potential for development as an antitumor agent in the future.
Conotoxin Diversity in the Venom Gland Transcriptome of the Magician’s Cone, Pionoconus magus
Authors: Pardos-Blas José R. , Irisarri Iker , Abalde Samuel , Tenorio Manuel J. , Zardoya Rafael
Published: September 2019

The transcriptomes of the venom glands of two individuals of the magician’s cone, Pionoconus magus, from Okinawa (Japan) were sequenced, assembled, and annotated. In addition, RNA-seq raw reads available at the SRA database from one additional specimen of P. magus from the Philippines were also assembled and annotated. The total numbers of identified conotoxin precursors and hormones per specimen were 118, 112, and 93. The three individuals shared only five identical sequences whereas the two specimens from Okinawa had 30 sequences in common. The total number of distinct conotoxin precursors and hormones for P. magus was 275, and were assigned to 53 conotoxin precursor and hormone superfamilies, two of which were new based on their divergent signal region. The superfamilies that had the highest number of precursors were M (42), O1 (34), T (27), A (18), O2 (17), and F (13), accounting for 55% of the total diversity. The D superfamily, previously thought to be exclusive of vermivorous cones was found in P. magus and contained a highly divergent mature region. Similarly, the A superfamily alpha 4/3 was found in P. magus despite the fact that it was previously postulated to be almost exclusive of the genus Rhombiconus. Differential expression analyses of P. magus compared to Chelyconus ermineus, the only fish-hunting cone from the Atlantic Ocean revealed that M and A2 superfamilies appeared to be more expressed in the former whereas the O2 superfamily was more expressed in the latter.
IL28B Genetic Variations in Patients with Recurrent Herpes Simplex Keratitis
Authors: Borivoje Savić , Svetlana Stanojlović , Milan Hadži-Milić , Nela Đonović , Olivera Milošević-Đorđević , Filip Milisavljević , Milenko Stojković , Srbislav Pajić
Published: September 2019

Background and objectives: Recurrent herpes simplex keratitis (HSK) is the most common cause of corneal blindness in the developed world. A relationship between host gene polymorphisms and the recurrence of herpes simplex virus (HSV) infection has previously been proposed. Thus, the aim of this study was to investigate a potential association between the IL28B host genotype and recurrent HSK. Materials and Methods: Eighty patients older than 18 years of age of both genders with a history of recurrent herpes simplex labialis (HSL) were considered for inclusion. Seventy-five of these patients were found to be seropositive for HSV-1 and were subsequently enrolled in the study. Twenty-four of the enrolled patients also had a history of recurrent HSK associated with severe corneal scarring and visual acuity deterioration. Total DNA was isolated from whole blood samples. A single-nucleotide polymorphism (SNP) rs12979860 near the IL28B gene on chromosome 19 was genotyped. Results: A significant association was observed between recurrent HSK and two SNPs of the IL28B genotype (CCrs12979860 and CTrs12979860, p < 0.01). The variation CCrs12979860 showed a significantly greater association with HSK (16 out of 26 patients) compared with CTrs12979860 (8 out of 34 patients). Conclusion: Seropositive individuals with a history of recurrent HSK are likely to have the CC IL28B genotype. This genotype may be related to incomplete control of the infection and more frequent periodical viral shedding along the first nerve branch of the trigeminal ganglion, which clinically manifests as recurrent herpes keratitis. The clinical manifestation of recurrent HSV-1 infection seems to be influenced by polymorphism of the IL28B genotype.
Factors Affecting Psychological Stress in Healthcare Workers with and without Chronic Pain: A Cross-Sectional Study Using Multiple Regression Analysis
Authors: Sakamoto Yuta , Oka Takeru , Amari Takashi , Shimo Satoshi
Published: September 2019

Background and Objectives: Pain affects psychological stress and general health in the working population. However, the factors affecting psychological job stress related to chronic pain are unclear. This study aimed to clarify the structural differences among factors affecting psychological job stress in workers with chronic pain and those without pain. Materials and Methods: A stepwise multiple regression analysis revealed the differences in structure between the psychological stress of workers with chronic pain and those with no pain. Psychological job stress by the Brief Job Stress Questionnaire was used as the dependent variable, with psychological state (depression and anxiety), specifically that characteristic of chronic pain (pain catastrophizing); information on the nature of the pain (intensity and duration); and number of years of service as independent variables. Selected independent variables were evaluated for collinearity. Results: In the model with psychological stress as a dependent variable (chronic pain: r2 = 0.57, F = 41.7, p < 0.0001; no-pain: r2 = 0.63, F = 26.3, p < 0.0001), the difference between the experiences of workers with chronic pain and those with no pain was that chronic pain was associated with depression (Beta = 0.43, p < 0.0001) and no pain with anxiety (Beta = 0.34, p < 0.0001). In the model with chronic pain-related depression as a dependent variable (r2 = 0.62, F = 41.7, p < 0.0001), job-life satisfaction (Beta = −0.18, p = 0.0017) and magnification (a dimension of pain catastrophizing; Beta = 0.16, p < 0.0001) were significant. Conclusions: The results of this study suggest that the psychological characteristics of chronic pain, such as depression and magnification, should be considered when evaluating and intervening in the job stress of workers with chronic pain.
Diagnostic Workup and Evaluation of Patients with Prurigo Nodularis
Authors: Kwon Christina D. , Khanna Raveena , Williams Kyle A. , Kwatra Madan M. , Kwatra Shawn G.
Published: September 2019

Prurigo nodularis (PN) is a chronic inflammatory skin disease characterized oftentimes by symmetrically distributed, severely pruritic nodules. Currently, the pathophysiology of PN remains to be fully elucidated, but emerging evidence suggests that neuroimmune alterations play principal roles in the pathogenesis of PN. There are several associated etiologic factors thought to be associated with PN, including dermatoses, systemic, infectious, psychiatric, and neurologic conditions. We conducted a systematic literature review to evaluate the clinical presentation, diagnosis, and etiologic factors of PN. In this review, we discuss common differential diagnoses of PN and recommend an evidence-based, standardized diagnostic evaluation for those with suspected PN.
Application of 1H-NMR Metabolomics for the Discovery of Blood Plasma Biomarkers of a Mediterranean Diet
Authors: Macias Shirin , Kirma Joseph , Yilmaz Ali , Moore Sarah E. , McKinley Michelle C. , McKeown Pascal P. , Woodside Jayne V. , Graham Stewart F. , Green Brian D.
Published: September 2019

The Mediterranean diet (MD) is a dietary pattern well-known for its benefits in disease prevention. Monitoring adherence to the MD could be improved by discovery of novel dietary biomarkers. The MEDiterranean Diet in Northern Ireland (MEDDINI) intervention study monitored the adherence of participants to the MD for up to 12 months. This investigation aimed to profile plasma metabolites, correlating each against the MD score of participants (n = 58). Based on an established 14-point scale MD score, subjects were classified into two groups (“low” and “high”). 1H-Nuclear Magnetic Resonance (1H-NMR) metabolomic analysis found that citric acid was the most significant metabolite (p = 5.99 × 10−4*; q = 0.03), differing between ‘low’ and ‘high’. Furthermore, five additional metabolites significantly differed (p < 0.05; q < 0.35) between the two groups. Discriminatory metabolites included: citric acid, pyruvic acid, betaine, mannose, acetic acid and myo-inositol. Additionally, the top five most influential metabolites in multivariate models were also citric acid, pyruvic acid, betaine, mannose and myo-inositol. Metabolites significantly correlated with the consumption of certain food types. For example, citric acid positively correlated fruit, fruit juice and vegetable constituents of the diet, and negatively correlated with sweet foods alone or when combined with carbonated drinks. Citric acid was the best performing biomarker and this was enhanced by paired ratio with pyruvic acid. The present study demonstrates the utility of metabolomic profiling for effectively assessing adherence to MD and the discovery of novel dietary biomarkers.
Effect of Nitrogen Doping on the Photoluminescence of Amorphous Silicon Oxycarbide Films
Authors: Song Jie , Huang Rui , Zhang Yi , Lin Zewen , Zhang Wenxing , Li Hongliang , Song Chao , Guo Yanqing , Lin Zhenxu
Published: September 2019

The effect of nitrogen doping on the photoluminescence (PL) of amorphous SiCxOy films was investigated. An increase in the content of nitrogen in the films from 1.07% to 25.6% resulted in red, orange-yellow, white, and blue switching PL. Luminescence decay measurements showed an ultrafast decay dynamic with a lifetime of ~1 ns for all the nitrogen-doped SiCxOy films. Nitrogen doping could also widen the bandgap of SiCxOy films. The microstructure and the elemental compositions of the films were studied by obtaining their Raman spectra and their X-ray photoelectron spectroscopy, respectively. The PL characteristics combined with an analysis of the chemical bonds configurations present in the films suggested that the switching PL was attributed to the change in defect luminescent centers resulting from the chemical bond reconstruction as a function of nitrogen doping. Nitrogen doping provides an alternative route for designing and fabricating tunable and efficient SiCxOy-based luminescent films for the development of Si-based optoelectronic devices.
Patterned Metal/Polymer Composite Film with Good Mechanical Stability and Repeatability for Flexible Electronic Devices Using Nanoimprint Technology
Authors: Zheng Xu , Wang Qing , Luan Jinjin , Li Yao , Wang Ning
Published: September 2019

Mechanical stability and repeatability are significant factors for the application of metal film flexible electronic devices. In this work, patterned metal/polymer composite films with good mechanical stability and repeatability were fabricated through nanoimprint technology. The mechanical properties characteristic of metal/polymer composite films were exhibited by resistance change (ΔR/R0) after cyclic tension and bending loading. It was found that the ΔR/R0 and error line of patterned metal/polymer composite film was far lower than the other control groups for repeated experiments, which indicates that patterned metal film has excellent mechanical properties and repeatability. The double cantilever beam method was employed to measure the interfacial adhesion properties of composite films. The average interfacial adhesion of patterned metal/polymer composite films is shown to be over 2.9 and 2.2 times higher than that of metal film deposited on bare polymer and metal nanowire-treated polymer substrates, respectively.
Genome Mining Coupled with OSMAC-Based Cultivation Reveal Differential Production of Surugamide A by the Marine Sponge Isolate Streptomyces sp. SM17 When Compared to Its Terrestrial Relative S. albidoflavus J1074
Authors: Almeida Eduardo , Kaur Navdeep , Jennings Laurence , Carrillo Rincón Andrés Felipe , Jackson Stephen , Thomas Olivier , Dobson Alan
Published: September 2019

Much recent interest has arisen in investigating Streptomyces isolates derived from the marine environment in the search for new bioactive compounds, particularly those found in association with marine invertebrates, such as sponges. Among these new compounds recently identified from marine Streptomyces isolates are the octapeptidic surugamides, which have been shown to possess anticancer and antifungal activities. By employing genome mining followed by an one strain many compounds (OSMAC)-based approach, we have identified the previously unreported capability of a marine sponge-derived isolate, namely Streptomyces sp. SM17, to produce surugamide A. Phylogenomics analyses provided novel insights on the distribution and conservation of the surugamides biosynthetic gene cluster (sur BGC) and suggested a closer relatedness between marine-derived sur BGCs than their terrestrially derived counterparts. Subsequent analysis showed differential production of surugamide A when comparing the closely related marine and terrestrial isolates, namely Streptomyces sp. SM17 and Streptomyces albidoflavus J1074. SM17 produced higher levels of surugamide A than S. albidoflavus J1074 under all conditions tested, and in particular producing >13-fold higher levels when grown in YD and 3-fold higher levels in SYP-NaCl medium. In addition, surugamide A production was repressed in TSB and YD medium, suggesting that carbon catabolite repression (CCR) may influence the production of surugamides in these strains.
Further Characterization of the RW-1 Monazite: A New Working Reference Material for Oxygen and Neodymium Isotopic Microanalysis
Authors: Wu Li-Guang , Li Xian-Hua , Ling Xiao-Xiao , Yang Yue-Heng , Li Chao-Feng , Li You-Lian , Mao Qian , Li Qiu-Li , Putlitz Benita
Published: September 2019

The oxygen (O) and neodymium (Nd) isotopic composition of monazite provides an ideal tracer of metamorphism and hydrothermal activity. Calibration of the matrix effect and monitoring of the external precision of monazite O–Nd isotopes with microbeam techniques, such as secondary ion mass spectrometry (SIMS) and laser ablation-multicollector-inductively coupled plasma-mass spectrometry (LA-MC-ICPMS), require well-characterized natural monazite standards for precise microbeam measurements. However, the limited number of standards available is impeding the application of monazite O–Nd isotopes. Here, we report on the RW-1 monazite as a potential new working reference material for microbeam analysis of O–Nd isotopes. Microbeam measurements by electron probe microanalysis (EPMA), SIMS, and LA-MC-ICPMS at 10–24 µm scales have confirmed that it is homogeneous in both elemental and O–Nd isotopic compositions. SIMS measurements yield δ18O values consistent, within errors, with those obtained by laser fluorination techniques. Precise analyses of Nd isotope by thermal ionization mass spectrometry (TIMS) are consistent with mean results of LA-MC-ICPMS analyses. We recommend δ18O = 6.30‰ ± 0.16‰ (2SD) and 143Nd/144Nd = 0.512282 ± 0.000011 (2SD) as being the reference values for the RW-1 monazite.
Ore Genesis of Shanmen Ag Deposit in Siping Area of Southern Jilin Province, NE China: Constraints from Fluid Inclusions and H-O, S, Pb Isotopes
Authors: Sun Xinhao , Ren Yunsheng , Cao Peng , Hao Yujie , Gao Yu
Published: September 2019

The Shanmen Ag deposit, located in the southeastern part of the Siping area, Jilin Province, is one of the large-scale Ag deposits in Northeastern (NE) China. Almost all Ag orebodies, Ag-bearing quartz-sulfide veins are strictly controlled by NE-trending faults or brittle fractures and are hosted in the Yanshanian monzonite and quartz diorite. In terms of deposit geology, three mineralization stages are recognized: the pyrite-quartz stage (I), the quartz-Ag-polymetallic sulfide stage (II), and the carbonate-quartz stage (III). The research results of the fluid inclusions in the different stages indicate that the early stage (Stage I) mainly contains three types of fluid inclusions: liquid-rich two-phase (L-type), vapor-rich two-phase (V-type), and CO2 aqueous multi-phase (C-type). The fluid belongs to a medium–high temperature and medium–low salinity H2O-NaCl-CO2 system and has boiling characteristics. The middle stage (Stage II) is mainly characterized by liquid-rich two-phase (L-type) and vapor-rich two-phase (V-type) inclusions, in which the mixing of fluids of different nature leads to the escape of CO2. Only liquid-rich two-phase (L-type) inclusions are distinguished in the late stage (Stage III). The fluids of two later stages belong to the medium-low-temperature and low-salinity H2O-NaCl system. Homogenization temperatures from the early to late stages range from 272.2 to 412.5 °C, 124.1 to 313.3 °C, and 128.6 to 224 °C, respectively. Fluid salinities in the early to late stages range from 1.6 to 12.1, 1.4 to 8.9, and 0.4 to 5.8 wt.% NaCl equivalent, respectively. The gradually decreasing trends of homogenization temperatures and salinities and the reduction in the CO2 content indicate that the release of CO2 and the low-temperature environment are important causes of the precipitation of Ag-bearing minerals. The δ18OH2O values of the ore-bearing quartz veins in the different stages range from −3.7 to +8.1‰, and the δD values of fluid inclusions in the quartz range from −113 to −103‰, indicating that the initial ore-forming fluid was mainly derived from magma and that the input of meteoric water gradually increased during the mineralization process. The δ34S values (ranging from −11.4‰ to +1.8‰) and Pb isotope compositions (206Pb/204Pb = 18.143–18.189, 207Pb/204Pb = 15.543–15.599, 208Pb/204Pb = 38.062–38.251) of sulfides suggest that the ore-forming materials have mixed mantle and crustal sources. Therefore, we propose that the release of CO2 and the low-temperature environment are important conditions for silver minerals precipitation, and the mixing of fluids of different nature is the dominant mechanism causing precipitation. The Shanmen Ag deposit can be classified as an intrusion-related medium–low temperature hydrothermal vein-type deposit.
Dehydroxylation and Structural Distortion of Kaolinite as a High-Temperature Sorbent in the Furnace
Authors: Cheng Yun , Xing Jingru , Bu Changsheng , Zhang Jubing , Piao Guilin , Huang Yaji , Xie Hao , Wang Xinye
Published: September 2019

As a high-temperature sorbent, kaolinite undergoes the flash calcination process in the furnace resulting in the dehydroxylation and structural distortion, which are closely related to its heavy metal/alkali metal adsorption characteristics. We investigated the flash calcination of kaolinite by the experiments using a drop tube furnace and by the characterization of flash-calcined products using thermogravimetric-differential scanning calorimeter (TG-DSC), X-ray diffraction (XRD), Fourier Transform Infrared Spectrometer (FTIR)and nuclear magnetic resonance (NMR). There were three kinds of hydroxyl groups in kaolinite during flash calcination at 800–1300 °C, E-type (~50%, easy), D-type (~40%, difficult) and U-type (~10%, unable) according to the removal difficulty. The hydroxyl groups activation was believed to be the first step of the removal of E-type and D-type hydroxyl groups. The kinetics model of dehydroxylation groups at 900–1200 °C was established following Arrhenius equation with the activation energy of 140 kJ/mol and the pre-exponential factor of 1.32 × 106 s−1. At 800 °C, the removal of E-type hydroxyl groups resulted in the conversion of a part of VI-coordinated Al in kaolinite to V-coordinated Al and the production of meta-kaolinite. When the temperature rose up to 1200 °C, mullite was produced and a part of V-coordinated Al converted to IV-coordinated Al and VI-coordinated Al. Finally, the adsorption characteristics of kaolinite was discussed according to the results of dehydroxylation and structural distortion.
Preliminary Study: Comparison of Antioxidant Activity of Cannabidiol (CBD) and α-Tocopherol Added to Refined Olive and Sunflower Oils
Authors: Tura Matilde , Mandrioli Mara , Gallina Toschi Tullia
Published: September 2019

This study evaluates the antioxidant activity of cannabidiol (CBD), added to model systems of refined olive (ROO) and sunflower (SO) oils, by measuring the peroxide value, oxidative stability index (OSI), electron spin resonance (ESR) forced oxidation, and DPPH• assays. Free acidity, a parameter of hydrolytic rancidity, was also examined. CBD was compared using the same analytical scheme with α-tocopherol. CBD, compared to α-tocopherol, showed a higher scavenging capacity, measured by DPPH• assay, but not better oxidative stability (OSI) of the oily systems considered. In particular, α-tocopherol (0.5%) showed an antioxidant activity only in SO, registered by an increase of more than 30% of the OSI (from 4.15 ± 0.07 to 6.28 ± 0.11 h). By ESR-forced oxidation assay, the concentration of free radicals (μM) in ROO decreased from 83.33 ± 4.56 to 11.23 ± 0.28 and in SO from 19.21 ± 1.39 to 6.90 ± 0.53 by adding 0.5% α-tocopherol. On the contrary, the addition of 0.5% CBD caused a worsening of the oxidative stability of ROO (from 23.58 ± 0.32 to 17.28 ± 0.18 h) and SO (from 4.93 ± 0.04 to 3.98 ± 0.04 h). Furthermore, 0.5% of CBD did not lower dramatically the concentration of free radicals (μM) as for α-tocopherol, which passed from 76.94 ± 9.04 to 72.25 ± 4.13 in ROO and from 17.91 ± 0.95 to 16.84 ± 0.25 in SO.
Steam Explosion Conditions Highly Influence the Biogas Yield of Rice Straw
Authors: Steinbach David , Wüst Dominik , Zielonka Simon , Krümpel Johannes , Munder Simon , Pagel Matthias , Kruse Andrea
Published: September 2019

Straws are agricultural residues that can be used to produce biomethane by anaerobic digestion. The methane yield of rice straw is lower than other straws. Steam explosion was investigated as a pretreatment to increase methane production. Pretreatment conditions with varying reaction times (12–30 min) and maximum temperatures (162–240 °C) were applied. The pretreated material was characterized for its composition and thermal and morphological properties. When the steam explosion was performed with a moderate severity parameter of S0 = 4.1 min, the methane yield was increased by 32% compared to untreated rice straw. This study shows that a harsher pretreatment at S0 > 4.3 min causes a drastic reduction of methane yield because inert condensation products are formed from hemicelluloses.
A Convenient Fluorescence-Based Assay for the Detection of Sucrose Transport and the Introduction of a Sucrose Transporter from Potato into Clostridium Strains
Authors: Zhang Zhikai , Lin Lihua , Tang Hongchi , Zeng Shaowei , Guo Yuan , Wei Yutuo , Huang Ribo , Pang Hao , Du Liqin
Published: September 2019

A convenient and effective sucrose transport assay for Clostridium strains is needed. Traditional methods, such as 14C-sucrose isotope labelling, use radioactive materials and are not convenient for many laboratories. Here, a sucrose transporter from potato was introduced into Clostridium, and a fluorescence assay based on esculin was used for the analysis of sucrose transport in Clostridium strains. This showed that the heterologously expressed potato sucrose transporter is functional in Clostridium. Recombinant engineering of high-level sucrose transport would aid sucrose fermentation in Clostridium strains. The assay described herein provides an important technological platform for studying sucrose transporter function following heterologous expression in Clostridium.
Inhibitory Effects of Novel 7-Substituted 6-iodo-3-O-Flavonol Glycosides against Cholinesterases and β-secretase Activities, and Evaluation for Potential Antioxidant Properties
Authors: Agbo Emmanuel N. , Gildenhuys Samantha , Mphahlele Malose J.
Published: September 2019

A series of 7-halogeno- (X = F, Cl, Br) and 7-methoxy-substituted acetylated 6-iodo-3-O-flavonol glycosides were prepared, and evaluated for inhibitory effect in vitro against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activities. 7-Bromo-2-(4-chlorophenyl)-6-iodo-4H-chromen-4-one-3-O-2,3,4,6-O-tetraacetyl-β-d-glucopyranoside (2k) and 7-bromo-6-iodo-2-(4-methoxyphenyl)-4H-chromen-4-one-3-O-2,3,4,6-O-tetraacetyl-β-d-glucopyranoside (2l) exhibited significant inhibitory effect against AChE activity when compared to the activity of the reference standard, donepezil. Compound 2k was found to be selective against AChE and to exhibit reduced inhibitory effect against BChE activity. 6-Iodo-7-methoxy-2-(4-methoxyphenyl)-4H-chromen-4-one-3-O-2,3,4,6-O-tetraacetyl-β-d-glucopyranoside (2p) was found to exhibit increased activity against BChE, more so than the activity of donepezil. The most active compounds were also evaluated for inhibitory effect against β-secretase activity and for potential radical scavenging activities. The experimental data were complemented with molecular docking (in silico) studies of the most active compounds into the active sites of these enzymes.
Residue of Paclobutrazol and Its Regulatory Effects on the Secondary Metabolites of Ophiopogon japonicas
Authors: Zhang Lixia , Luo Zuliang , Cui Shengrong , Xie Lei , Yu Jing , Tang Deying , Ma Xiaojun , Mou Yan
Published: September 2019

Currently, paclobutrazol is excessively used in the planting process of Ophiopogon japonicus (O. japonicus) due to its important role in regulating the growth of tuber roots, ultimately increasing the yield and shortening the growth cycle of Ophiopogonis Radix. For insight into this process and the potential risks of paclobutrazol and its mediated consequences on the secondary metabolites in Ophiopogonis Radix, corresponding high performance liquid chromatography-tandem mass spectrometric methods (HPLC-MS/MS) were developed in this study and then applied to Ophiopogonis Radix, soil, and water samples. The results demonstrated the detection of different levels of paclobutrazol residue were in Ophiopogonis Radix, soil, and water samples. In addition, the quantitative results of the secondary metabolites showed that paclobutrazol significantly decreased four steroidal saponins in Ophiopogonis Radix, especially ophiopogonin D, where the content was decreased from 824.87 to 172.50 mg/kg. Concurrently, ophiopogonanone C, a flavonoid in Ophiopogonis Radix, also significantly decreased from 2.66 to 1.33 mg/kg. In conclusion, the residual paclobutrazol and its negative regulation on the secondary metabolism of Ophiopogonis Radix brings potential hazards to the environment and human health. These results provide more comprehensive data that can be used for the reassessment of the use of paclobutrazol in O. japonicus and the formulation of related standards.
Anti-Inflammatory Activity of the Wild Mushroom, Echinodontium tinctorium, in RAW264.7 Macrophage Cells and Mouse Microcirculation
Authors: Javed Sumreen , Li Wai Ming , Zeb Mehreen , Yaqoob Almas , Tackaberry Linda E. , Massicotte Hugues B. , Egger Keith N. , Cheung Peter C.K. , Payne Geoffrey W. , Lee Chow H.
Published: September 2019

The aim of this study was to investigate the anti-inflammatory activity of a previously un-studied wild mushroom, Echinodontium tinctorium, collected from the forests of north-central British Columbia. The lipopolysaccharide (LPS)-induced RAW264.7 macrophage model was used to study the in vitro anti-inflammatory activity. The crude alkaline extract demonstrated potent anti-inflammatory activity, and was further purified using a “bio-activity-guided-purification” approach. The size-exclusion and ion-exchange chromatography yielded a water-soluble anti-inflammatory polysaccharide (AIPetinc). AIPetinc has an average molecular weight of 5 kDa, and is a heteroglucan composed of mainly glucose (88.6%) with a small amount of galactose (4.0%), mannose (4.4%), fucose (0.7%), and xylose (2.3%). In in vivo settings, AIPetinc restored the histamine-induced inflammatory event in mouse gluteus maximus muscle, thus confirming its anti-inflammatory activity in an animal model. This study constitutes the first report on the bioactivity of Echinodontium tinctorium, and highlights the potential medicinal benefits of fungi from the wild forests of northern British Columbia. Furthermore, it also reiterates the need to explore natural resources for alternative treatment to modern world diseases.
Tolerance and Recovery of Ultralow-Loaded Platinum Anode Electrodes upon Carbon Monoxide and Hydrogen Sulfide Exposure
Authors: Prass Sebastian , Friedrich Kaspar Andreas , Zamel Nada
Published: September 2019

The effects of carbon monoxide (CO) and hydrogen sulfide (H2S) in concentrations close to their respective limits in the Hydrogen Quality Standard ISO 14687-2:2012 on the performance of proton exchange membrane fuel cells (PEMFCs) with ultralow-loaded platinum anode catalyst layers (CLs) were investigated. The anodic loadings were 50, 25, and 15 µg/cm2, which represent the current state-of-the-art, target, and stretch target, respectively, for future automotive PEMFCs. Additionally, the effect of shut-down and start-up (SD/SU) processes on recovery from sulfur poisoning was investigated. CO at an ISO concentration of 0.2 ppm caused severe voltage losses of ~40–50% for ultralow-loaded anode CLs. When H2S was in the fuel, these anode CLs exhibited both a nonlinear decrease in tolerance toward sulfur and an improved self-recovery during shut-down and start-up (SD/SU) processes. This observation was hypothesized to have resulted from the decrease in the ratio between CL thickness and geometric cell area, as interfacial effects of water in the pores increasingly impacted the performance of ultrathin CLs. The results indicate that during the next discussions on the Hydrogen Quality Standard, a reduction in the CO limit could be a reasonable alternative considering future PEMFC anodic loadings, while the H2S limit might not require modification.
Generation of Flat Top Surface Plasmon Polariton Beams by Near Field Holography
Authors: Qiu Peizhen , Bai Chunyan , Lv Taiguo , Zhang Dawei
Published: September 2019

Controlling the shape and trajectory of the surface plasmon polariton (SPP) beams is the key to all SPP-based applications. In this paper, a novel plasmonic device that can generate in-plane flat top SPP beams is designed by near field holography. The relationship between the transverse profile intensity of the generated flat top SPP beams and the structural parameters of the designed device is analyzed. The results of this paper can provide the possibility for further practical application utilizing flat top SPP beams.