bluuebunny/crossref_metadata_2025 huggingface dataset:
Non-SMC Condensin I Complex Subunit H (NCAPH) Is Associated with Lymphangiogenesis and Drug Resistance in Oral Squamous Cell Carcinoma
Authors: Shimomura Hiroyuki , Sasahira Tomonori , Nakashima Chie , Kurihara-Shimomura Miyako , Kirita Tadaaki
Published: December 2019

Background: Head and neck cancer, including oral squamous cell carcinoma (OSCC), is the sixth most common malignancy. OSCC has strong invasive ability, and its malignant potential is closely associated with local expansion and lymph node metastasis. Furthermore, local or nodal recurrence worsens OSCC prognosis. In our previous cDNA microarray analysis, non-structural maintenance of chromosome (SMC) condensin I complex subunit H (NCAPH) was identified as an upregulated gene in recurrent OSCC. Although NCAPH has several functions in tumors, its role in OSCC is unknown. Methods: In this study, we examined NCAPH expression in OSCC and performed a functional analysis of human OSCC cells. Results: NCAPH expression was higher in OSCC than in normal oral mucosa. In immunohistochemistry using 142 OSCC specimens, the immunostaining of NCAPH was strongly associated with nodal metastasis and lymphatic infiltration. In multivariate analysis using the Cox proportional hazards model, NCAPH expression was an independent poor prognostic indicator for OSCC. Moreover, NCAPH promoted the migration and adhesion of endothelial cells to OSCC cells and promoted the resistance to platinum anticancer drugs. Conclusions: Our present findings suggest that NCAPH is a novel diagnostic and therapeutic target in OSCC.
Independent Impact of Gynoid Fat Distribution and Free Testosterone on Circulating Levels of N-Terminal Pro-Brain Natriuretic Peptide (NT-proBNP) in Humans
Authors: Chlabicz Małgorzata , Jamiołkowski Jacek , Paniczko Marlena , Sowa Paweł , Łapińska Magda , Szpakowicz Małgorzata , Jurczuk Natalia , Kondraciuk Marcin , Raczkowski Andrzej , Sawicka Emilia , Kamiński Karol Adam
Published: December 2019

Background: Natriuretic peptides (NPs), including brain natriuretic peptide (BNP), are neurohormones involved in the regulation of water-sodium balance and the maintenance of cardiovascular homeostasis. A higher concentration of NPs is observed in females, but the mechanism behind this difference has not been fully elucidated. Methods: Randomly chosen 255 volunteers from the general population were examined. Overall, 196 people without severe cardiovascular disease were included (mean age 48 years, 35.7% male). A comprehensive assessment was performed, including anthropometric measurements, N-terminal pro-brain natriuretic peptide (NT-proBNP), total testosterone (TT) and sex hormone-binding globulin (SHBG) concentration, transthoracic echocardiography (ECHO), and body composition analysis by direct dual-energy X-ray absorptiometry (DEXA). The univariate analysis adjusted by the known affecting factors determined which measurements were independently associated with NT-proBNP concentration. Results: NT-proBNP concentration was positively associated with gynoid fat mass, gynoid/total fat (G/TF) mass index, SHBG and negatively with android/gynoid (A/G) fat mass index, TT and calculated free testosterone (CFT) concentrations. Furthermore, body composition parameters remained independently associated with NT-proBNP levels even after adjusting for CFT and SHBG. Conclusion: In the population without severe cardiovascular disease, the NT-proBNP concentration is independently associated with lower availability of testosterone and higher gynoid fat distribution, which may explain higher NPs levels in females.
The Impact of Gene Dosage and Heterozygosity on the Diploid Pathobiont Candida albicans
Authors: Liang Shen-Huan , Bennett Richard J.
Published: December 2019

Candida albicans is a fungal species that can colonize multiple niches in the human host where it can grow either as a commensal or as an opportunistic pathogen. The genome of C. albicans has long been of considerable interest, given that it is highly plastic and can undergo a wide variety of alterations. These changes play a fundamental role in determining C. albicans traits and have been shown to enable adaptation both to the host and to antifungal drugs. C. albicans isolates contain a heterozygous diploid genome that displays variation from the level of single nucleotides to largescale rearrangements and aneuploidy. The heterozygous nature of the genome is now increasingly recognized as being central to C. albicans biology, as the relative fitness of isolates has been shown to correlate with higher levels of overall heterozygosity. Moreover, loss of heterozygosity (LOH) events can arise frequently, either at single polymorphisms or at a chromosomal level, and both can alter the behavior of C. albicans cells during infection or can modulate drug resistance. In this review, we examine genome plasticity in this pathobiont focusing on how gene dosage variation and loss of heterozygosity events can arise and how these modulate C. albicans behavior.
Language Difficulty and Prior Learning Influence Foreign Vocabulary Acquisition
Authors: Hayakawa Sayuri , Bartolotti James , van den Berg Aimee , Marian Viorica
Published: December 2019

When learning a foreign language, words that are the hardest to learn are often the easiest to forget. Yet, there is also evidence that more challenging learning contexts can lead to greater long-term retention. Here, we investigate the effect of language difficulty on vocabulary retention by teaching participants novel words that varied in both imageability and similarity to a known language over a period of four weeks. We found that easier words (high-imageability and familiar) were generally retained better than harder words (low-imageability and unfamiliar). However, when words were fully learned during training, the more difficult unfamiliar words were later recalled with higher accuracy than easier familiar words. The effect of language difficulty on vocabulary retention therefore varies depending on how well words were initially encoded. We conclude that greater challenges can reap greater long-term rewards so long as learners establish a strong foundation during initial acquisition.
Dynamic Mechanical Behavior of Fiber-Reinforced Seawater Coral Mortars
Authors: Long Wu-Jian , Tang Jiangsong , Li Hao-Dao , Wang Yaocheng , Luo Qi-Ling
Published: December 2019

Coral aggregate has been widely used for island construction because of its local availability. However, the addition of coral aggregate exaggerates the brittle nature of cement-based materials under dynamic loading. In this study, polyvinyl alcohol (PVA) fiber was used to improve dynamic mechanical behavior of seawater coral mortars (SCMs). The effects of coral aggregate and PVA fiber on the workability, static mechanical strengths, and dynamic mechanical behavior of fiber-reinforced SCMs were investigated. Results showed that the workability of the SCM decreased with increasing coral aggregate replacement rate and PVA fiber content. Mechanical strengths of the SCM increased with increasing PVA fiber content, but decreased with increasing coral aggregate replacement rate. Dynamic mechanical behavior at varying coral aggregate replacement rates was analyzed by combining dynamic mechanical analysis and micro-scale elastic modulus experiment. With increasing coral aggregate replacement rate, the storage modulus, loss factor, and elastic modulus of the interfacial transition zone in the SCM decreased. Nevertheless, with the incorporation of PVA fibers (1 vol.%), the storage modulus and loss factor were improved dramatically by 151.9 and 73.3%, respectively, compared with the reference group. Therefore, fiber-reinforced coral mortars have a great potential for use in island construction, owing to the excellent anti-vibrational performance.
Quantitative Correlation between Thermal Cycling and the Microstructures of X100 Pipeline Steel Laser-Welded Joints
Authors: Wang Gang , Wang Jinzhao , Yin Limeng , Hu Huiqin , Yao Zongxiang
Published: December 2019

Due to the limitations of the energy density and penetration ability of arc welding technology for long-distance pipelines, the deterioration of the microstructures in the coarse-grained heat-affected zone (HAZ) in welded joints in large-diameter, thick-walled pipeline steel leads to insufficient strength and toughness in these joints, which strongly affect the service reliability and durability of oil and gas pipelines. Therefore, high-energy-beam welding is introduced for pipeline steel welding to reduce pipeline construction costs and improve the efficiency and safety of oil and gas transportation. In the present work, two pieces of X100 pipeline steel plates with thicknesses of 12.8 mm were welded by a high-power robot laser-welding platform. The quantitative correlation between thermal cycling and the microstructure of the welded joint was studied using numerical simulation of the welding temperature field, optical microscopy (OM), and scanning electron microscopy (SEM) with energy-dispersive spectroscopy (EDS). The results show that the heat-source model of a Gaussian-distributed rotating body and the austenitization degree parameters are highly accurate in simulating the welding temperature field and characterizing the austenitization degree. The effects of austenitization are more significant than those of the cooling rate on the final microstructures of the laser-welded joint. The microstructure of the X100 pipeline steel in the HAZ is mainly composed of acicular ferrite (AF), granular bainite (GB), and bainitic ferrite (BF). However, small amounts of lath martensite (LM), upper bainite (UB), and the bulk microstructure are found in the columnar zone of the weld. The aim of this paper is to provide scientific guidance and a reference for the simulation of the temperature field during high-energy-beam laser welding and to study and formulate the laser-welding process for X100 pipeline steel.
Hardness and Indentation Fracture Toughness of Slip Cast Alumina and Alumina-Zirconia Ceramics
Authors: Žmak Irena , Ćorić Danko , Mandić Vilko , Ćurković Lidija
Published: December 2019

Alumina (Al2O3) and zirconia (ZrO2) have good overall properties and thus are widely used oxide technical ceramics. The biggest drawback of Al2O3 is its low fracture toughness. In contrast, ZrO2 is relatively tough, but is also much more expensive. In order to improve the alumina toughness, composite ceramics are being developed. Slip casting technology has economic advantages over the conventional hot isostatic pressure technology, but problems may arise when preparing stable highly-concentrated suspensions (slip) for filling the mold. The purpose of this study is to prepare aqueous suspensions using 70 wt. % α-Al2O3, with 0, 1, 5 and 10 wt. % of added t-ZrO2. Suspensions were electrosterically stabilized using the ammonium salt of polymethylacrylic acid, an alkali-free anionic polyelectrolyte dispersant. Also, magnesium oxide in form of magnesium aluminate spinel (MgAl2O4) was used to inhibit the abnormal alumina grain growth during the sintering process. Minimum viscosities were used as stability estimators, where an increase in ZrO2 content required adding more dispersant. After sintering, the Vickers indentation test was used to determine the hardness and the indentation fracture toughness from the measurement of the crack length. Also, the brittleness index (Bi, μm−1/2) was calculated from values of Vickers hardness and the Vickers indentation fracture toughness. It was found that with increasing ZrO2 content the fracture toughness increased, while the hardness as well as the brittleness index decreased. Zirconia loading reduces the crystallite sizes of alumina, as confirmed by the X-ray diffraction analysis. SEM/EDS analysis showed that ZrO2 grains are distributed in the Al2O3 matrix, forming some agglomerates of ZrO2 and some pores, with ZrO2 having a smaller grain size than Al2O3.
Microstructure and Mechanical Properties of Vacuum Plasma Sprayed HfC, TiC, and HfC/TiC Ultra-High-Temperature Ceramic Coatings
Authors: Kim Ho Seok , Kang Bo Ram , Choi Seong Man
Published: December 2019

To improve the oxidation resistance of carbon composites at high temperatures, hafnium carbide (HfC) and titanium carbide (TiC) ultra-high-temperature ceramic coatings were deposited using vacuum plasma spraying. Single-layer HfC and TiC coatings and multilayer HfC/TiC coatings were fabricated and compared. The microstructure and composition of the fabricated coatings were analyzed using field-emission scanning electron microscopy and energy dispersive X-ray spectroscopy. The coating thicknesses of the HfC and TiC single-layer coatings were 165 µm and 140 µm, respectively, while the thicknesses of the HfC and TiC layers in the HfC/TiC multi-layer coating were 40 µm and 50 µm, respectively. No oxides were observed in any of the coating layers. The porosity was analyzed from cross-sectional images of the coating layers obtained using optical microscopy. Five random areas for each coating layer specimen were analyzed, and average porosity values of approximately 16.8% for the HfC coating and 22.5% for the TiC coating were determined. Furthermore, the mechanical properties of the coating layers were investigated by measuring the hardness of the cross section and surface roughness. The hardness values of the HfC and TiC coatings were 1650.7 HV and 753.6 HV, respectively. The hardness values of the HfC and TiC layers in the multilayer sample were 1563.5 HV and 1059.2 HV, respectively. The roughness values were 5.71 µm for the HfC coating, 4.30 µm for the TiC coating, and 3.32 µm for the HfC/TiC coating.
Study of Catalytic Combustion of Dioxins on Ce-V-Ti Catalysts Modified by Graphene Oxide in Simulating Iron Ore Sintering Flue Gas
Authors: Shi Qi , Ding Long , Long Hong-Ming , Chun Tie-Jun
Published: December 2019

Ce-V-Ti and Ce-V-Ti/GO catalysts synthesized by the sol-gel method were used for the catalytic combustion of dioxins at a low temperature under simulating sintering flue gas in this paper. The catalytic mechanism of Ce-V-Ti catalysts modified with graphene oxides (GO) at a low temperature was revealed through X-ray diffractometer (XRD), Brunauer–Emmett–Teller (BET), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), H2-temperature-programmed reduction (H2-TPR) and Fourier transform infrared (FTIR). During the tests, chlorobenzene (CB) was used as a model reagent since the dioxins are poisonous. The results showed that introducing GO to Ce-V-Ti catalysts can improve the specific surface area and promote the CB adsorption on the surface of catalysts. Simultaneously, the Ce-V-Ti with 0.7 wt % GO support showed the high activity with the conversion of 60% at 100 °C and 80% at 150 °C. The adsorb ability of catalysts is strengthened by the electron interaction between GO and CB through π-π bond. In the case of Ce-V-Ti catalysts, Ce played a major catalytic role and V acted as a co-catalytic composition. After GO modification, the concentration of Ce3+ and V4+ were enlarged. The synergy between Ce3+ and V3+ played the critical role on the low-temperature performance of catalysts under sintering flue gas.
Strength and Micro-Mechanism Analysis of Cement-Emulsified Asphalt Cold Recycled Mixture
Authors: Pi Yuhui , Li Yan , Pi Yingxing , Huang Zhe , Li Zhe
Published: December 2019

The strength of EACRM (emulsified asphalt cold recycled mixture) is closely related to the properties and proportion of raw materials. In this paper, the strength formation mechanism of EACRM was first studied through microscopic analysis, and the influence regular of aggregate gradation, emulsified asphalt, water consumption, cement consumption, and other factors on its strength was analyzed through a series of laboratory tests. The analysis results show that the asphalt binder plays the role of cementing material in cement emulsified asphalt mortar. The combination of cement and emulsified asphalt is a physical combination. The hydration product not only increases the viscosity of asphalt cement, but also makes the surface of asphalt cement become uneven, which increases the adhesion area with the aggregate. Therefore, the microstructure of the interface between mortar and aggregate is improved. The bonding force of the interface and the mechanical properties of concrete are improved. Due to the influence of recycled asphalt pavement (RAP) materials, the excessive amount of emulsified asphalt and cement are not conducive to improve the strength of cold recycled mixture. Through experiments, the optimal amount of emulsified asphalt and cement is determined as 2.9% and 1.5%, respectively, for the RAP materials. At the same time, improving the performance of emulsified asphalt and adding quicklime and organic activator are also helpful to improve the strength of a cold recycled mixture.
Bird-Strike Resistance of Composite Laminates with Different Materials
Authors: Zhou Yadong , Sun Youchao , Huang Tianlin
Published: December 2019

To obtain some basic laws for bird-strike resistance of composite materials in aeronautical application, the high-velocity impact behaviors of composite laminates with different materials were studied by numerical methods. The smoothed particle hydrodynamics (SPH) and finite element method (FEM) coupling models were validated from various perspectives, and the numerical results were comparatively investigated. Results show that the different composite materials have relatively little effect on projectile deformations during the bird impact. However, the impact-damage distributions can be significantly different for different composite materials. The strength parameters and fracture energy parameters play different roles in different damage modes. Lastly, modal frequency was tentatively used to explain the damage behavior of the composite laminates, for it can manifest the mass and stiffness characteristics of a dynamic structure. The dynamic properties and strength properties jointly determine the impact-damage resistance of composite laminates under bird strike. Future optimization study can be considered from these two aspects.
A Novel Role of Ascorbic Acid in Anti-Inflammatory Pathway and ROS Generation in HEMA Treated Dental Pulp Stem Cells
Authors: Diomede Francesca , Marconi Guya Diletta , Guarnieri Simone , D’Attilio Michele , Cavalcanti Marcos F. X. B. , Mariggiò Maria A. , Pizzicannella Jacopo , Trubiani Oriana
Published: December 2019

Resin (co)monomers issued from restorative dental materials are able to distribute in the dental pulp or the gingiva, to get to the saliva and to the flowing blood. Many authors have recently shown that methacrylate-based resins, in particular 2-hydroxyethylmethacrylate (HEMA), are responsible of inflammatory and autophagic processes in human dental pulp stem cells (hDPSCs) while ascorbic acid (AS), an antioxidant molecule, can assume a protective role in cell homeostasis. The purpose of the current work was to study if 50 µg/mL AS can affect the inflammatory status induced by 2 mM HEMA in hDPSCs, a tissue–specific cell population. Cell proliferation, cytokine release, morphological arrangement and reactive oxygen species (ROS) formation were determined respectively by MTT, ELISA, morphological analysis and dichlorofluorescein assay. The hDPSCs exposed to HEMA let to an increment of ROS formation and in the expression of high levels of inflammatory mediators such as nuclear factor-κB (NFkB), inflammatory cytokines such as interleukin IL6, IL8, interferon (IFN)ɣ and monocyte chemoattractant protein (MCP)1. Moreover, HEMA induced the up-regulation of pospho-extracellular signal–regulated kinases (pERK)/ERK signaling pathway associated to the nuclear translocation. AS treatment significantly down-regulated the levels of pro-inflammatory mediators. Then, the natural product AS reduced the detrimental result promoted by methacrylates in clinical dentistry, in fact restore cell proliferation, reduce the pro-inflammatory cytokine, downregulate ROS production and of NFkB/pERK/ERK signaling path. In synthesis, AS, could improve the quality of dental care and play a strategic role as innovative endodontic compound easy to use and with reasonable cost.
Preparation of Hydrogen Electrodes of Solid Oxide Cells by Infiltration: Effects of the Preparation Procedure on the Resulting Microstructure
Authors: Hołówko Bartosz , Karczewski Jakub , Molin Sebastian , Jasiński Piotr
Published: December 2019

In this work, the infiltration technique was used to produce hydrogen electrodes for solid oxide cells. Different infiltration methodologies were tested in order to try to shorten the infiltration cycle time. The porous scaffolds used for infiltration were based on highly porous yttria-stabilized zirconia (YSZ) obtained by etching the reduced nickel from the Ni-YSZ cermet in HNO3 acid. The support had a complex structure which included a ~130 µm porous functional layer with small pores and a ~320 µm thick supporting layer with large pores. Infiltrations have been carried out using aqueous nickel nitrate solutions. Various infiltration procedures were used, differing in temperature/time profiles. The results show that slow evaporation is crucial for obtaining a homogeneous material distribution leading to high-quality samples. A longer evaporation time promotes the proper distribution of nickel throughout the porous scaffold. The shortening of the heat treatment procedure leads to blockage of the pores and not-uniform nickel distribution.
Marine Compounds and Cancer: The First Two Decades of XXI Century
Authors: Dyshlovoy Sergey A. , Honecker Friedemann
Published: December 2019

In 2019, the scientific and medical community celebrated the 50th anniversary of the introduction of the very first marine-derived drug, Cytarabine, into clinics [...]
New Napyradiomycin Analogues from Streptomyces sp. Strain CA-271078
Authors: Carretero-Molina Daniel , Ortiz-López Francisco Javier , Martín Jesús , Oves-Costales Daniel , Díaz Caridad , de la Cruz Mercedes , Cautain Bastien , Vicente Francisca , Genilloud Olga , Reyes Fernando
Published: December 2019

As part of our continuing efforts to discover new bioactive compounds from microbial sources, a reinvestigation of extracts of scaled-up cultures of the marine-derived Streptomyces sp. strain CA-271078 resulted in the isolation and structural elucidation of four new napyradiomycins (1–3, 5). The known napyradiomycin SC (4), whose structural details had not been previously described in detail, and another ten related known compounds (6–15). The structures of the new napyradiomycins were characterized by HRMS and 1D- and 2D-NMR spectroscopies and their relative configurations were established through a combination of molecular modelling with nOe and coupling constants NMR analysis. The absolute configuration of each compound is also proposed based on biosynthetic arguments and the comparison of specific rotation data with those of related compounds. Among the new compounds, 1 was determined to be the first non-halogenated member of napyradiomycin A series containing a functionalized prenyl side chain, while 2–4 harbor in their structures the characteristic chloro-cyclohexane ring of the napyradiomycin B series. Remarkably, compound 5 displays an unprecedented 14-membered cyclic ether ring between the prenyl side chain and the chromophore, thus representing the first member of a new class of napyradiomycins that we have designated as napyradiomycin D1. Anti-infective and cytotoxic properties for all isolated compounds were evaluated against a set of pathogenic microorganisms and the HepG2 cell line, respectively. Among the new compounds, napyradiomycin D1 exhibited significant growth-inhibitory activity against methicillin-resistant Staphylococcus aureus, Mycobacterium tuberculosis, and HepG2.
Functional Characterization of Carbohydrate-Binding Modules in a New Alginate Lyase, TsAly7B, from Thalassomonas sp. LD5
Authors: Zhang Zhelun , Tang Luyao , Bao Mengmeng , Liu Zhigang , Yu Wengong , Han Feng
Published: December 2019

Alginate lyases degrade alginate into oligosaccharides, of which the biological activities have vital roles in various fields. Some alginate lyases contain one or more carbohydrate-binding modules (CBMs), which assist the function of the catalytic modules. However, the precise function of CBMs in alginate lyases has yet to be fully elucidated. We have identified a new multi-domain alginate lyase, TsAly7B, in the marine bacterium Thalassomonas sp. LD5. This novel lyase contains an N-terminal CBM9, an internal CBM32, and a C-terminal polysaccharide lyase family 7 (PL7) catalytic module. To investigate the specific function of each of these CBMs, we expressed and characterized the full-length TsAly7B and three truncated mutants: TM1 (CBM32-PL7), TM2 (CBM9-PL7), and TM3 (PL7 catalytic module). CBM9 and CBM32 could enhance the degradation of alginate. Notably, the specific activity of TM2 was 7.6-fold higher than that of TM3. CBM32 enhanced the resistance of the catalytic module to high temperatures. In addition, a combination of CBM9 and CBM32 showed enhanced thermostability when incubated at 80 °C for 1 h. This is the first report that finds CBM9 can significantly improve the ability of enzyme degradation. Our findings provide new insight into the interrelationships of tandem CBMs and alginate lyases and other polysaccharide-degrading enzymes, which may inspire CBM fusion strategies.
Celiac Disease: A Common Unrecognized Health Problem with a Very Delayed Diagnosis
Authors: Rodrigo Luis
Published: December 2019

Celiac disease (CD) is a clinical entity of autoimmune nature, related to the presence of a permanent gluten intolerance that affects genetically predisposed individuals, producing a chronic inflammation process that usually occurs in the small bowel [...]
An Approach for Modelling Slag Infiltration and Heat Transfer in Continuous Casting Mold for High Mn–High Al Steel
Authors: Yang Jie , Chen Dengfu , Long Mujun , Duan Huamei
Published: December 2019

To clarify the characteristics of slag infiltration and heat transfer behaviors in the meniscus region during the casting of high Mn–high Al steel, a mathematical model of a continuous casting mold that couples fluid flow with heat transfer, and solidification is developed. The model is based on the change in slag composition and properties caused by the steel/slag reaction. The formation and evolution of the meniscus profile and slag films for different mold fluxes during mold oscillation are described. The results show that the rapid growth of the slag rim with a high Al2O3 content approaches and deforms the meniscus so that a series of casting problems such as slag infiltration blocking, large fluctuations in heat flux, and even meniscus breaking occur in the continuous casting process. Predictions are in good agreement with plant measurements. These findings provide an improved understanding of the complex phenomena occurring in the meniscus region and give new insights into the evaluation and optimization of mold flux properties for high Mn–high Al steel casting.
Improved DRUS 4H-SiC MESFET with High Power Added Efficiency
Authors: Jia Hujun , Liang Yuan , Li Tao , Tong Yibo , Zhu Shunwei , Wang Xingyu , Zeng Tonghui , Yang Yintang
Published: December 2019

A 4H-SiC metal semiconductor field effect transistor (MESFET) with layered doping and undoped space regions (LDUS-MESFET) is proposed and simulated by ADS and ISE-TCAD software in this paper. The structure (LDUS-MESFET) introduced layered doping under the lower gate of the channel, while optimizing the thickness of the undoped region. Compared with the double-recessed 4H-SiC MESFET with partly undoped space region (DRUS-MESFET), the power added efficiency of the LDUS-MESFET is increased by 85.8%, and the saturation current is increased by 27.4%. Although the breakdown voltage of the device has decreased, the decrease is within an acceptable range. Meanwhile, the LDUS-MESFET has a smaller gate-source capacitance and a large transconductance. Therefore, the LDUS-MESFET can better balance DC and AC characteristics and improve power added efficiency (PAE).
Flow and Tableting Behaviors of Some Egyptian Kaolin Powders as Potential Pharmaceutical Excipients
Authors: Awad Mahmoud E. , López-Galindo Alberto , Medarević Djordje , Đuriš Jelena , El-Rahmany Mahmoud M. , Ibrić Svetlana , Viseras César
Published: December 2019

The present work aimed at assessing the pharmaceutical tableting properties of some Egyptian kaolin samples belong to the Abu Zenima kaolin deposits (estimated at 120 million tons). Four representative samples were selected based on kaolinite richness and their structural order-disorder degree, and after purification, they were dried at 70 °C and heated from room temperature up to 400 °C (10 °C/min). Mineralogy, micromorphology, microtexture, granulometry, porosimetry, moisture content, bulk and tapped density, direct and indirect flowability, and tableting characteristics are studied. Results indicated that purified kaolin samples were made up of 95–99% kaolinite, <3% illite, 1% quartz and 1% anatase. The powder showed mesoporous character (pore diameters from 2 to 38 nm and total pore volume from 0.064 to 0.136 cm3/g) with dominance of fine nanosized particles (<1 μm–10 nm). The powder flow characteristics of both the ordered (Hinckley Index HI > 0.7, crystallite size D001 > 30 nm) and disordered (HI < 0.7, D001 < 30 nm) kaolinite-rich samples have been improved (Hausner ratio between 1.24 and 1.09) as their densities were influenced by thermal treatment (with some observed changes in the kaolinite XRD reflection profiles) and by moisture content (variable between 2.98% and 5.82%). The obtained tablets exhibited hardness between 33 and 44 N only from the dehydrated powders at 400 °C, with elastic recovery (ER) between 21.74% and 25.61%, ejection stress (ES) between 7.85 and 11.45 MPa and tensile fracture stress (TFS) between 1.85 and 2.32 MPa, which are strongly correlated with crystallinity (HI) and flowability (HR) parameters. These findings on quality indicators showed the promising pharmaceutical tabletability of the studied Egyptian kaolin powders and the optimization factors for their manufacturability and compactability.
REE Enrichment during Magmatic–Hydrothermal Processes in Carbonatite-Related REE Deposits: A Case Study of the Weishan REE Deposit, China
Authors: Jia Yu-heng , Liu Yan
Published: December 2019

The Weishan carbonatite-related rare earth element (REE) deposit in China contains both high- and low-grade REE mineralization and is an informative case study for the investigation of magmatic–hydrothermal REE enrichment processes in such deposits. The main REE-bearing mineral is bastnäsite, with lesser parisite and monazite. REE mineralization occurred at a late stage of hydrothermal evolution and was followed by a sulfide stage. Barite, calcite, and strontianite appear homogeneous in back-scattered electron images and have high REE contents of 103–217, 146–13,120, and 194–16,412 ppm in their mineral lattices, respectively. Two enrichment processes were necessary for the formation of the Weishan deposit: Production of mineralized carbonatite and subsequent enrichment by magmatic–hydrothermal processes. The geological setting and petrographic characteristics of the Weishan deposit indicate that two main factors facilitated REE enrichment: (1) fractures that facilitated circulation of ore-forming fluids and provided space for REE precipitation and (2) high ore fluorite and barite contents resulting in high F− and SO42− concentrations in the ore-forming fluids that promoted REE transport and deposition.
Crystallographic and Seismic Anisotropies of Calcite at Different Depths: A Study Using Quantitative Texture Analysis by Neutron Diffraction
Authors: Zucali Michele , Chateigner Daniel , Ouladdiaf and Bachir
Published: December 2019

Eight samples of limestones and marbles were studied by neutron diffraction to collect quantitative texture (i.e., crystallographic preferred orientations or CPO) of calcite deforming at different depths in the crust. We studied the different Texture patterns developed in shear zones at different depth and their influence on seismic anisotropies. Samples were collected in the French and Italian Alps, Apennines, and Paleozoic Sardinian basement. They are characterized by isotropic to highly anisotropic (e.g., mylonite shear zone) fabrics. Mylonite limestones occur as shear zone horizons within the Cenozoic Southern Domain in Alpine thrust-and-fold belts (Italy), the Briançonnais domain of the Western Alps (Italy-France border), the Sardinian Paleozoic back-thrusts, or in the Austroalpine intermediate units. The analyzed marbles were collected in the Carrara Marble, in the Austroalpine Units in the Central (Mortirolo) and Western Alps (Valpelline). The temperature and depth of development of fabrics vary from <100 ∘ C, to 800 ∘ C and depth from <10 km to about 30 km, corresponding from upper to lower crust conditions. Quantitative Texture Analysis shows different types of patterns for calcite: random to strongly textured. Textured types may be further separated in orthorhombic and monoclinic (Types A and B), based on the angle defined with the mesoscopic fabrics. Seismic anisotropies were calculated by homogenizing the single-crystal elastic tensor, using the Orientation Distribution Function calculated by Quantitative Texture Analysis. The resulting P- and S-wave anisotropies show a wide variability due to the textural types, temperature and pressure conditions, and dip of the shear planes.
The Antibacterial Activity of Lavender Essential Oil Alone and In Combination with Octenidine Dihydrochloride against MRSA Strains
Authors: Kwiatkowski Paweł , Łopusiewicz Łukasz , Kostek Mateusz , Drozłowska Emilia , Pruss Agata , Wojciuk Bartosz , Sienkiewicz Monika , Zielińska-Bliźniewska Hanna , Dołęgowska Barbara
Published: December 2019

In the post-antibiotic era the issue of bacterial resistance refers not only to antibiotics themselves but also to common antiseptics like octenidine dihydrochloride (OCT). This appears as an emerging challenge in terms of preventing staphylococcal infections, which are both potentially severe and easy to transfer horizontally. Essential oils have shown synergisms both with antibiotics and antiseptics. Therefore the aim of this study was to investigate the impact of lavender essential oil (LEO) on OCT efficiency towards methicillin-resistant S. aureus strains (MRSA). The LEO analyzed in this study increased the OCT’s susceptibility against MRSA strains. Subsequent FTIR analysis revealed cellular wall modifications in MRSA strain cultured in media supplemented with OCT or LEO/OCT. In conclusion, LEO appears to be a promising candidate for an efficient enhancer of conventional antiseptics.
Hybrid Material Based on an Amorphous-Carbon Matrix and ZnO/Zn for the Solar Photocatalytic Degradation of Basic Blue 41
Authors: Lanfredi Silvania , Nobre Marcos A. L. , Poon Po S. , Matos Juan
Published: December 2019

Innovative composites based on an amorphous-carbon matrix containing a second phase ZnO oxide and/or highly dispersed Zn metallic were synthesized via a modified Pechini route, in which a partial pyrolysis method was reached. Studies of adsorption in the dark and the photocatalytic activity for the cationic azo-dye, basic blue 41, and degradation were carried out. X-ray diffraction patterns for the carbon matrix and its composite with Zn show characteristics of the amorphous carbon. The infrared in the mid region of the composite prepared with ZnO and Zn exhibit vibrational bands related to bonds zinc oxide. The surface pH of the material is the main factor responsible for the adsorption of the azo-dye, but the contribution of mesopores favored the diffusion of molecules from the bulk of solution to the pore framework. Esters-like functional groups on the surface of carbons hinder the adsorption of the azo-dye. When Zn is embedded within amorphous carbon the photocatalytic activity of the composites showed up to 2.4 higher than neat ZnO. The enhancement in the photocatalytic activity and stability of C/ZnO/Zn and C/Zn composites is discussed in terms of a protector effect by the carbon layers inserted in composites. Carbon layers are responsible to inhibit the lixiviation of ZnO particles along irradiation.
PredPSD: A Gradient Tree Boosting Approach for Single-Stranded and Double-Stranded DNA Binding Protein Prediction
Authors: Tan Changgeng , Wang Tong , Yang Wenyi , Deng Lei
Published: December 2019

Interactions between proteins and DNAs play essential roles in many biological processes. DNA binding proteins can be classified into two categories. Double-stranded DNA-binding proteins (DSBs) bind to double-stranded DNA and are involved in a series of cell functions such as gene expression and regulation. Single-stranded DNA-binding proteins (SSBs) are necessary for DNA replication, recombination, and repair and are responsible for binding to the single-stranded DNA. Therefore, the effective classification of DNA-binding proteins is helpful for functional annotations of proteins. In this work, we propose PredPSD, a computational method based on sequence information that accurately predicts SSBs and DSBs. It introduces three novel feature extraction algorithms. In particular, we use the autocross-covariance (ACC) transformation to transform feature matrices into fixed-length vectors. Then, we put the optimal feature subset obtained by the minimal-redundancy-maximal-relevance criterion (mRMR) feature selection algorithm into the gradient tree boosting (GTB). In 10-fold cross-validation based on a benchmark dataset, PredPSD achieves promising performances with an AUC score of 0.956 and an accuracy of 0.912, which are better than those of existing methods. Moreover, our method has significantly improved the prediction accuracy in independent testing. The experimental results show that PredPSD can significantly recognize the binding specificity and differentiate DSBs and SSBs.
Carbazole Alkaloids from Clausena anisum-olens: Isolation, Characterization, and Anti-HIV Evaluation
Authors: Yang Jing-Hua , Wang Xin-Yi , Zhou Yi-Ping , Lu Rong , Chen Chin-Ho , Zhang Meng-Han , Cheng Yung-Yi , Morris-Natschke Susan L. , Lee Kuo-Hsiung , Wang Yun-Song
Published: December 2019

Two new carbazole alkaloids (1,2) and six known carbazole alkaloids (3–8) were isolated from Clausena anisum-olens. Their structures were elucidated based on extensive spectroscopic analysis. All isolated compounds (1–8) were evaluated for their anti-HIV effects on virus replication in MT-4 lymphocytes infected by HIV-1NL4-3 Nanoluc-sec virus, and new carbazole alkaloid 1 exhibited anti-HIV activity with an EC50 value of 2.4 μg/mL and SI of 7.1.
Efficient Synthesis of Purine Nucleoside Analogs by a New Trimeric Purine Nucleoside Phosphorylase from Aneurinibacillus migulanus AM007
Authors: Liu Gaofei , Cheng Tiantong , Chu Jianlin , Li Sui , He Bingfang
Published: December 2019

Purine nucleoside phosphorylases (PNPs) are promising biocatalysts for the synthesis of purine nucleoside analogs. Although a number of PNPs have been reported, the development of highly efficient enzymes for industrial applications is still in high demand. Herein, a new trimeric purine nucleoside phosphorylase (AmPNP) from Aneurinibacillus migulanus AM007 was cloned and heterologously expressed in Escherichia coli BL21(DE3). The AmPNP showed good thermostability and a broad range of pH stability. The enzyme was thermostable below 55 °C for 12 h (retaining nearly 100% of its initial activity), and retained nearly 100% of the initial activity in alkaline buffer systems (pH 7.0–9.0) at 60 °C for 2 h. Then, a one-pot, two-enzyme mode of transglycosylation reaction was successfully constructed by combining pyrimidine nucleoside phosphorylase (BbPyNP) derived from Brevibacillus borstelensis LK01 and AmPNP for the production of purine nucleoside analogs. Conversions of 2,6-diaminopurine ribonucleoside (1), 2-amino-6-chloropurine ribonucleoside (2), and 6-thioguanine ribonucleoside (3) synthesized still reached >90% on the higher concentrations of substrates (pentofuranosyl donor: purine base; 20:10 mM) with a low enzyme ratio of BbPyNP: AmPNP (2:20 μg/mL). Thus, the new trimeric AmPNP is a promising biocatalyst for industrial production of purine nucleoside analogs.
Oxoisoaporphines and Aporphines: Versatile Molecules with Anticancer Effects
Authors: Rodríguez-Arce Esteban , Cancino Patricio , Arias-Calderón Manuel , Silva-Matus Paul , Saldías Marianela
Published: December 2019

Cancer is a disease that involves impaired genome stability with a high mortality index globally. Since its discovery, many have searched for effective treatment, assessing different molecules for their anticancer activity. One of the most studied sources for anticancer therapy is natural compounds and their derivates, like alkaloids, which are organic molecules containing nitrogen atoms in their structure. Among them, oxoisoaporphine and sampangine compounds are receiving increased attention due to their potential anticancer effects. Boldine has also been tested as an anticancer molecule. Boldine is the primary alkaloid extract from boldo, an endemic tree in Chile. These compounds and their derivatives have unique structural properties that potentially have an anticancer mechanism. Different studies showed that this molecule can target cancer cells through several mechanisms, including reactive oxygen species generation, DNA binding, and telomerase enzyme inhibition. In this review, we summarize the state-of-art research related to oxoisoaporphine, sampangine, and boldine, with emphasis on their structural characteristics and the relationship between structure, activity, methods of extraction or synthesis, and anticancer mechanism. With an effective cancer therapy still lacking, these three compounds are good candidates for new anticancer research.
Neutral Rhenadicarbaboranes with Re(CO)2(NO) Vertices: A Theoretical Study of Building Blocks for Rhenacarborane-Based Drug Delivery Agents
Authors: Attia Amr A. A. , Lupan Alexandru , Silaghi-Dumitrescu Radu , King R. Bruce
Published: December 2019

The rhenadicarbaborane carbonyl nitrosyls (C2Bn−3Hn−1)Re(CO)2(NO), (n = 8 to 12), of interest in drug delivery agents based on the experimentally known C2B9H11Re(CO)2(NO) and related species, have been investigated by density functional theory. The lowest energy structures of these rhenadicarbaboranes are all found to have central ReC2Bn−3 most spherical closo deltahedra in accord with their 2n + 2 Wadean skeletal electrons. Carbon atoms are found to be located preferentially at degree 4 vertices in such structures. Furthermore, rhenium atoms are preferentially located at a highest degree vertex, typically a vertex of degree 5. Only for the 9-vertex C2B6H8Re(CO)2(NO) system are alternative isocloso deltahedral isomers found within ~8 kcal/mol of the lowest energy closo isomer. Such 9-vertex isocloso structures provide a degree 6 vertex for the rhenium atom flanked by degree 4 vertices for each carbon atom.
Single-Grain Quartz OSL Characteristics: Testing for Correlations within and between Sites in Asia, Europe and Africa
Authors: Hu Yue , Li Bo , Jacobs Zenobia
Published: December 2019

We studied the characteristics of the optically stimulated luminescence (OSL) signal of single-grain quartz from three sites in China, Italy, and Libya, including the brightness, decay curve and dose response curve (DRC) shapes, recuperation, and reproducibility. We demonstrate the large variation in OSL behaviors for individual quartz grains of different samples from different regions, and show that recuperation, sensitivity change, and reproducibility are independent of the brightness and decay curve shape of the OSL signals. The single-grain DRCs can be divided into at least eight groups with different characteristic saturation doses (D0), and a standardized growth curve (SGC) can be established for each of the DRC groups. There is no distinctive difference in the shape of OSL decay curves among different DRC groups, but samples from different regions have a difference in the OSL sensitivities and decay shapes for different groups. Many of the quartz grains have low D0 values (30–50 Gy), and more than 99% of the grains have D0 values of <200 Gy. Our results raise caution against the dating of samples with equivalent dose values higher than 100 Gy, if there are many low-D0 and ‘saturated’ grains.
First Proof-of-Principle of Inorganic Lead Halide Perovskites Deposition by Magnetron-Sputtering
Authors: Borri Claudia , Calisi Nicola , Galvanetto Emanuele , Falsini Naomi , Biccari Francesco , Vinattieri Anna , Cucinotta Giuseppe , Caporali Stefano
Published: December 2019

The present work reports the application of RF-magnetron sputtering technique to realize CsPbBr 3 70 nm thick films on glass substrate by means of a one-step procedure. The obtained films show highly uniform surface morphology and homogeneous thickness as evidenced by AFM and SEM investigations. XRD measurements demonstrate the presence of two phases: a dominant orthorhombic CsPbBr 3 and a subordinate CsPb 2 Br 5 . Finally, XPS data reveals surface bromine depletion respect to the stoichiometrical CsPbBr 3 composition, nevertheless photoluminescence spectroscopy results confirm the formation of a highly luminescent film. These preliminary results demonstrate that our approach could be of great relevance for easy fabrication of large area perovskite thin films. Future developments, based on this approach, may include the realization of multijunction solar cells and multicolor light emitting devices.
Insights into the Microstructure of Hydrothermal Synthesized Nanoscale K2O-Al2O3-SiO2-H2O Particles
Authors: Liu Bao , Zhu Chunyan , Zhuang Kunde , Shuai Le , Li Dongxu , Long Wujian , Xing Feng , Fang Yuan
Published: December 2019

K-A-S-H (K2O-Al2O3-SiO2-H2O) gel is a key phase that forms in most alkali-activated binders (eco-friendly binders which utilize a substantial amount of industrial by-product). An in-depth understanding of the microstructure and performance of this nano-sized key phase facilitates better application to alkali-activated binders. However, such studies remain little and undetailed. Therefore, our research aims to provide insights into the microstructure of K-A-S-H particles synthesized with accurate stoichiometric control by the hydrothermal method through thermogravimetric analysis (TG), Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and BET surface area. The results show that for materials prepared at the curing temperature lower than 80 °C, the K-A-S-H products were completely amorphous. With increased curing temperature and time, the K-A-S-H products were transformed from the amorphous phase to the crystalline zeolite phase structure, with a reduction in the specific surface area. The TG results indicate that the crystalline phase contains more non-evaporated water or zeolite water for structural rearrangement. The degree of tetrahedral polymerization slightly decreased with an increase of the K2O/SiO2 ratio as the amount of non-bridged oxygen atoms increased, whereas it gradually increased with an increase of curing temperature and time, as suggested by the FTIR and NMR results. Various K2O/SiO2 ratios resulted in the formation of zeolite K-H and K-G zeolite, both of which exhibited highly polymerized three-dimensional network structures. However, there was no significant effect of the SiO2/Al2O3 ratio on the structure of K-A-S-H products. Overall, these results provide insight into understanding the chemical stability of K-A-S-H.