bluuebunny/crossref_metadata_2025 huggingface dataset:
Applicability and Limitations in the Characterization of Poly-Dispersed Engineered Nanomaterials in Cell Media by Dynamic Light Scattering (DLS)
Authors: Marucco Arianna , Aldieri Elisabetta , Leinardi Riccardo , Bergamaschi Enrico , Riganti Chiara , Fenoglio Ivana
Published: November 2019

The dispersion protocol used to administer nanomaterials (NMs) in in vitro cellular tests might affect their toxicity. For this reason, several dispersion procedures have been proposed to harmonize the toxicological methods, allowing for the comparison of the data that were obtained by different laboratories. At the same time, several techniques and methods are available to monitor the identity of the NMs in the cell media. However, while the characterization of suspensions of engineered NMs having narrow size distribution may be easily performed, the description of aggregated NMs forming polydispersions is still challenging. In the present study, sub-micrometric/nanometric TiO2, SiO2, and CeO2 were dispersed in cell media by using two different dispersion protocols, with and without albumin (0.5%) and with different sonication procedures. Dynamic Light Scattering (DLS) was used to characterize NMs in stock solutions and culture media. Pitfalls that affect DLS measurements were identified and, guidance on a critical analysis of the results provided. The NMs were then tested for their cytotoxicity (LDH leakage) toward murine macrophages (RAW 264.7) and PMA-activated human monocytes (THP-1). As markers of pro-inflammatory response, nitric oxide (NO) and cytokine IL-1β production were measured on RAW 264.7 and THP-1 cells, respectively. The pre-treatment with albumin added to a strong sonication treatment increases the stability and homogeneity of the suspensions of nanometric samples, but not of the submicrometric-samples. Nevertheless, while TiO2 and CeO2 were non-cytotoxic in any conditions, differences in cytotoxicity, NO, and IL-1β releases were found for the SiO2, depending upon the protocol. Overall, the results suggest that there is no one-fits-all method valid for all NMs, since each class of NMs respond differently. The definition of validated procedures and parameters for the selection of the most appropriate method of dispersion for each class of NM appears to be a more efficacious strategy for the harmonization of the dispersion protocols.
Implementation of Numerical Mesostructure Concrete Material Models: A Dot Matrix Method
Authors: Xie Hao , Feng Jili
Published: November 2019

We develop a dot matrix method (DMM) using the principles of computational geometry to place aggregates into matrices for the construction of mesolevel concrete models efficiently and rapidly. The basic idea of the approach is to transform overlap detection between polygons (or polyhedrons) into checking the possibility of any intersection between the point sets within a trial placement aggregate and the already placed ones in mortar. Through the arithmetic operation of integer point sets, the efficiency of the underlying algorithm in the dot matrix method is higher. Our parking algorithm holds several advantages comparing with the conventional placement issues. First, it is suitable for arbitrary-shape aggregate particles. Second, it only needs two sets for examining if the overlap between a trial placement aggregate and the already placed ones. Third, it accurately places aggregates according to aggregate grading curves, by order of reduction, led to more efficiently reducing aggregate placement time. The present method is independent of the size of aggregate particles. Combing with 3D laser scanning technology, the present method can also be used to create mesostructure concrete models conveniently and flexibly. Several examples show that DDM is a robust and valid method to construct mesostructure concrete models.
Characterization of the Acid-Base Character of Burned Clay Ceramics Used for Water Decontamination
Authors: Sandu Andrei Victor , Vasilache Viorica , Sandu Ioan Gabriel , Sieliechi Joseph M. , Kouame Innocent Kouassi , Matasaru Petre Daniel , Sandu Ion
Published: November 2019

The paper presents the results of ample investigations performed on industrial and traditional ceramics of fired clay used in processes of water potabilization in the last stage of filtration, after that of active charcoal. Using the data obtained through the scanning electron microscope coupled with energy dispersive X-ray analysis (SEM-EDX) and pH analyses, on the basis of the atomic composition and free concentration of hydronium ions, the normal caustic (Si/Al) and summative [(Si+Ti+FeIII+Cl)/(Al+Ca+Mg+Na+K)] modules were assessed, which were correlated with the free acidity and, respectively, the capacity of absorption and ionic exchange of the Fe3+ and Al3+ ions. The study allowed the selection, on the basis of the caustic module, of the ceramics with high capacity for ionic exchange.
Influence of Vanadium on the Microstructure of IN718 Alloy by Laser Cladding
Authors: Yang Kun , Xie Hualong , Sun Cong , Zhao Xiaofei , Li Fei
Published: November 2019

A deleterious Laves phase forms in the solidified structure of Inconel 718 (IN718) alloy during laser cladding. However, effective removal methods have not yet been identified. In this study, we first added the IN718 alloy cladding layers with a trace amount of vanadium (V, 0.066 wt.%). Then, we studied the solidification structure of cladding layers using a confocal laser scanning microscope and scanning electron microscopy. The microstructure and Laves phase morphology were investigated. The distribution of niobium (Nb) was observed by experiment as well. We found that V is evenly distributed in dendrites and interdendritic zones. A more refined dendrite structure, reduced second dendrite arm spacing and lower volume fraction of Laves phase were observed in the solidification structure. The results of linear energy-dispersive X-ray spectroscopy (EDS) indicate that the concentration of Nb decreases with an increasing of the distance from the Laves phase. The V-containing sample displayed a relatively slower decreasing tendency. The IN718 alloy sample was harder with the addition of V. In addition, the porosity of the sample decreased compared with the blank sample. The presented findings outline a new method to inhibit the Nb segregation in IN718 alloy during laser cladding, providing reference significance for improving the performance of IN718 alloy samples during actual processing.
Open-Cell Aluminum Foams by the Sponge Replication Technique
Authors: Sutygina Alina , Betke Ulf , Scheffler Michael
Published: November 2019

Open-cell aluminum foams were manufactured by a sponge replication technique having a total porosity of ~90%. The influence of the thermal processing conditions such as atmosphere and temperature on the cellular structure, phase composition porosity, thermal conductivity, and compressive strength of the foams was studied. It was found that the thermal processing of aluminum foams in Ar at temperatures up to 800 °C led to aluminum foams with a reduced strut porosity, a lower amount of aluminum oxide, a higher thermal conductivity, and a higher compression strength, compared to foams thermally processed in air. These results were explained by the lower amount of aluminum oxide after thermal processing of the foams.
Finite Element Simulation Study of Ultrasonic Vibration-Assisted Tensile High-Volume Fraction SiCp/Al Composite
Authors: Zhang Zhi-meng , Xiang Dao-hui , Wu Bang-fu , Feng Hao-ren , Shi Zhan-li , Hu Yong-wei , Zhao Bo
Published: November 2019

Silicon carbide particle-reinforced aluminum matrix composite (SiCp/Al) has been widely used in the military and aerospace industry due to its special performance; however, there remain many problems in the processing. The present paper introduces an ultrasonic vibration tensile apparatus and a composite tensile specimen and performs Abaqus finite element simulation on high-volume SiCp/Al. The results show that the stress-strain curve increases linearly during conventional tensile strength; the intermittent vibration tensile strength is similar to the full course vibration tensile strength: The magnitude of the stress reduction increases as the amplitude of the ultrasound increases and the vibration frequency increases. The tensile rate is inversely proportional to the magnitude of the stress reduction, and in the ultrasonic parameters, the amplitude has the greatest influence on the magnitude of the stress reduction, followed by the tensile rate; additionally, the frequency has the least influence on the magnitude of the stress reduction. The experimental results show that the simulation results are consistent with the experimental results.
Simulation of Ti-6Al-4V Additive Manufacturing Using Coupled Physically Based Flow Stress and Metallurgical Model
Authors: Babu Bijish , Lundbäck Andreas , Lindgren Lars-Erik
Published: November 2019

Simulating the additive manufacturing process of Ti-6Al-4V is very complex due to the microstructural changes and allotropic transformation occurring during its thermomechanical processing. The α -phase with a hexagonal close pack structure is present in three different forms—Widmanstatten, grain boundary and Martensite. A metallurgical model that computes the formation and dissolution of each of these phases was used here. Furthermore, a physically based flow-stress model coupled with the metallurgical model was applied in the simulation of an additive manufacturing case using the directed energy-deposition method. The result from the metallurgical model explicitly affects the mechanical properties in the flow-stress model. Validation of the thermal and mechanical model was performed by comparing the simulation results with measurements available in the literature, which showed good agreement.
Properties and Applications of Extremozymes from Deep-Sea Extremophilic Microorganisms: A Mini Review
Authors: Jin Min , Gai Yingbao , Guo Xun , Hou Yanping , Zeng Runying
Published: November 2019

The deep sea, which is defined as sea water below a depth of 1000 m, is one of the largest biomes on the Earth, and is recognised as an extreme environment due to its range of challenging physical parameters, such as pressure, salinity, temperature, chemicals and metals (such as hydrogen sulphide, copper and arsenic). For surviving in such extreme conditions, deep-sea extremophilic microorganisms employ a variety of adaptive strategies, such as the production of extremozymes, which exhibit outstanding thermal or cold adaptability, salt tolerance and/or pressure tolerance. Owing to their great stability, deep-sea extremozymes have numerous potential applications in a wide range of industries, such as the agricultural, food, chemical, pharmaceutical and biotechnological sectors. This enormous economic potential combined with recent advances in sampling and molecular and omics technologies has led to the emergence of research regarding deep-sea extremozymes and their primary applications in recent decades. In the present review, we introduced recent advances in research regarding deep-sea extremophiles and the enzymes they produce and discussed their potential industrial applications, with special emphasis on thermophilic, psychrophilic, halophilic and piezophilic enzymes.
A Novel Alkaline Phosphatase/Phosphodiesterase, CamPhoD, from Marine Bacterium Cobetia amphilecti KMM 296
Authors: Noskova Yulia , Likhatskaya Galina , Terentieva Natalia , Son Oksana , Tekutyeva Liudmila , Balabanova Larissa
Published: November 2019

A novel extracellular alkaline phosphatase/phosphodiesterase from the structural protein family PhoD that encoded by the genome sequence of the marine bacterium Cobetia amphilecti KMM 296 (CamPhoD) has been expressed in Escherichia coli cells. The calculated molecular weight, the number of amino acids, and the isoelectric point (pI) of the mature protein’s subunit are equal to 54832.98 Da, 492, and 5.08, respectively. The salt-tolerant, bimetal-dependent enzyme CamPhoD has a molecular weight of approximately 110 kDa in its native state. CamPhoD is activated by Co2+, Mg2+, Ca2+, or Fe3+ at a concentration of 2 mM and exhibits maximum activity in the presence of both Co2+ and Fe3+ ions in the incubation medium at pH 9.2. The exogenous ions, such as Zn2+, Cu2+, and Mn2+, as well as chelating agents EDTA and EGTA, do not have an appreciable effect on the CamPhoD activity. The temperature optimum for the CamPhoD activity is 45 °C. The enzyme catalyzes the cleavage of phosphate mono- and diester bonds in nucleotides, releasing inorganic phosphorus from p-nitrophenyl phosphate (pNPP) and guanosine 5′-triphosphate (GTP), as determined by the Chen method, with rate approximately 150- and 250-fold higher than those of bis-pNPP and 5′-pNP-TMP, respectively. The Michaelis–Menten constant (Km), Vmax, and efficiency (kcat/Km) of CamPhoD were 4.2 mM, 0.203 mM/min, and 7988.6 S−1/mM; and 6.71 mM, 0.023 mM/min, and 1133.0 S−1/mM for pNPP and bis-pNPP as the chromogenic substrates, respectively. Among the 3D structures currently available, in this study we found only the low identical structure of the Bacillus subtilis enzyme as a homologous template for modeling CamPhoD, with a new architecture of the phosphatase active site containing Fe3+ and two Ca2+ ions. It is evident that the marine bacterial phosphatase/phosphidiesterase CamPhoD is a new structural member of the PhoD family.
Simultaneous Increase of Electrical Conductivity and Hardness of Al–1.5 wt.% Mn Alloy by Addition of 1.5 wt.% Cu and 0.5 wt.% Zr
Authors: Belov Nikolay , Korotkova Natalya , Akopyan Torgom , Tsydenov Kirill
Published: November 2019

The effect of Cu and Zr additions and annealing temperature on electrical conductivity and hardness of the Al–1.5 wt.% Mn alloy in the form of as-cast ingots and cold rolled sheets has been investigated. It is shown that due to the formation of low alloyed aluminum solid solution and Al20Cu2Mn3 and Al3Zr (L12) phase nanoparticles, the 1.5MnCuZr alloy is superior to the base 1.5Mn alloy both in the hardness (up to two times) and electrical conductivity (up to 30%) after metal processing and annealing. A new alloy can be considered as a replacement for existing 6201 type conductive alloys.
Experimental Design and Sample Preparation in Forest Tree Metabolomics
Authors: Rodrigues Ana M. , Ribeiro-Barros Ana I. , António Carla
Published: November 2019

Appropriate experimental design and sample preparation are key steps in metabolomics experiments, highly influencing the biological interpretation of the results. The sample preparation workflow for plant metabolomics studies includes several steps before metabolite extraction and analysis. These include the optimization of laboratory procedures, which should be optimized for different plants and tissues. This is particularly the case for trees, whose tissues are complex matrices to work with due to the presence of several interferents, such as oleoresins, cellulose. A good experimental design, tree tissue harvest conditions, and sample preparation are crucial to ensure consistency and reproducibility of the metadata among datasets. In this review, we discuss the main challenges when setting up a forest tree metabolomics experiment for mass spectrometry (MS)-based analysis covering all technical aspects from the biological question formulation and experimental design to sample processing and metabolite extraction and data acquisition. We also highlight the importance of forest tree metadata standardization in metabolomics studies.
Detecting Pulmonary Oxygen Toxicity Using eNose Technology and Associations between Electronic Nose and Gas Chromatography–Mass Spectrometry Data
Authors: Wingelaar Thijs T. , Brinkman Paul , de Vries Rianne , van Ooij Pieter-Jan A.M. , Hoencamp Rigo , Maitland-van der Zee Anke-Hilse , Hollmann Markus W. , van Hulst Rob A.
Published: November 2019

Exposure to oxygen under increased atmospheric pressures can induce pulmonary oxygen toxicity (POT). Exhaled breath analysis using gas chromatography–mass spectrometry (GC–MS) has revealed that volatile organic compounds (VOCs) are associated with inflammation and lipoperoxidation after hyperbaric–hyperoxic exposure. Electronic nose (eNose) technology would be more suited for the detection of POT, since it is less time and resource consuming. However, it is unknown whether eNose technology can detect POT and whether eNose sensor data can be associated with VOCs of interest. In this randomized cross-over trial, the exhaled breath from divers who had made two dives of 1 h to 192.5 kPa (a depth of 9 m) with either 100% oxygen or compressed air was analyzed, at several time points, using GC–MS and eNose. We used a partial least square discriminant analysis, eNose discriminated oxygen and air dives at 30 min post dive with an area under the receiver operating characteristics curve of 79.9% (95%CI: 61.1–98.6; p = 0.003). A two-way orthogonal partial least square regression (O2PLS) model analysis revealed an R² of 0.50 between targeted VOCs obtained by GC–MS and eNose sensor data. The contribution of each sensor to the detection of targeted VOCs was also assessed using O2PLS. When all GC–MS fragments were included in the O2PLS model, this resulted in an R² of 0.08. Thus, eNose could detect POT 30 min post dive, and the correlation between targeted VOCs and eNose data could be assessed using O2PLS.
Microfluidic Passive Valve with Ultra-Low Threshold Pressure for High-Throughput Liquid Delivery
Authors: Zhang Xinjie , Oseyemi Ayobami Elisha
Published: November 2019

The microvalve for accurate flow control under low fluidic pressure is vital in cost-effective and miniaturized microfluidic devices. This paper proposes a novel microfluidic passive valve comprising of a liquid chamber, an elastic membrane, and an ellipsoidal control chamber, which actualizes a high flow rate control under an ultra-low threshold pressure. A prototype of the microvalve was fabricated by 3D printing and UV laser-cutting technologies and was tested under static and time-dependent pressure conditions. The prototype microvalve showed a nearly constant flow rate of 4.03 mL/min, with a variation of ~4.22% under the inlet liquid pressures varied from 6 kPa to 12 kPa. In addition, the microvalve could stabilize the flow rate of liquid under the time-varying sinusoidal pressures or the square wave pressures. To validate the functionality of the microvalve, the prototype microvalve was applied in a gas-driven flow system which employed an air blower or human mouth blowing as the low-cost gas source. The microvalve was demonstrated to successfully regulate the steady flow delivery in the system under the low driving pressures produced by the above gas sources. We believe that this new microfluidic passive valve will be suitable for controlling fluid flow in portable microfluidic devices or systems of wider applications.
Comparison between Focused Electron/Ion Beam-Induced Deposition at Room Temperature and under Cryogenic Conditions
Authors: De Teresa José , Orús Pablo , Córdoba Rosa , Philipp Patrick
Published: November 2019

In this contribution, we compare the performance of Focused Electron Beam-induced Deposition (FEBID) and Focused Ion Beam-induced Deposition (FIBID) at room temperature and under cryogenic conditions (the prefix “Cryo” is used here for cryogenic). Under cryogenic conditions, the precursor material condensates on the substrate, forming a layer that is several nm thick. Its subsequent exposure to a focused electron or ion beam and posterior heating to 50 °C reveals the deposit. Due to the extremely low charge dose required, Cryo-FEBID and Cryo-FIBID are found to excel in terms of growth rate, which is typically a few hundred/thousand times higher than room-temperature deposition. Cryo-FIBID using the W(CO)6 precursor has demonstrated the growth of metallic deposits, with resistivity not far from the corresponding deposits grown at room temperature. This paves the way for its application in circuit edit and the fast and direct growth of micro/nano-electrical contacts with decreased ion damage. The last part of the contribution is dedicated to the comparison of these techniques with other charge-based lithography techniques in terms of the charge dose required and process complexity. The comparison indicates that Cryo-FIBID is very competitive and shows great potential for future lithography developments.
Different Regimes of Opto-fluidics for Biological Manipulation
Authors: Winskas John T. , Wang Hao , Zhdanov Arsenii , Cheemalapati Surya , Deonarine Andrew , Westerheide Sandy , Pyayt Anna
Published: November 2019

Metallic structures can be used for the localized heating of fluid and the controlled generation of microfluidic currents. Carefully designed currents can move and trap small particles and cells. Here we demonstrate a new bi-metallic substrate that allows much more powerful micro-scale manipulation. We show that there are multiple regimes of opto-fluidic manipulation that can be controlled by an external laser power. While the lowest power does not affect even small objects, medium power can be used for efficiently capturing and trapping particles and cells. Finally, the high-power regime can be used for 3D levitation that, for the first time, has been demonstrated in this paper. Additionally, we demonstrate opto-fluidic manipulation for an extraordinarily dynamic range of masses extending eight orders of magnitude: from 80 fg nano-wires to 5.4 µg live worms.
Doxorubicin·Hydrochloride/Cisplatin-Loaded Hydrogel/Nanosized (2-Hydroxypropyl)-Beta-Cyclodextrin Local Drug-Delivery System for Osteosarcoma Treatment In Vivo
Authors: Yoon Sun Jung , Moon Young Jae , Chun Heung Jae , Yang Dae Hyeok
Published: November 2019

Osteosarcoma (OSA) is a difficult cancer to treat due to its tendency for relapse and metastasis; advanced methods are therefore required for OSA treatment. In this study, we prepared a local drug-delivery system for OSA treatment based on doxorubicin·hydrochloride (DOX·HCl)/cisplatin (CP)-loaded visible light-cured glycol chitosan (GC) hydrogel/(2-hydroxypropyl)-beta-cyclodextrin (GDHCP), and compared its therapeutic efficiency with that of DOX·HCl- and CP-loaded GC hydrogels (GD and GHCP). Because of diffusion driven by concentration gradients in the swollen matrix, the three hydrogels showed sustained releases of DOX·HCl and CP over 7 days, along with initial 3-h bursts. Results of in vitro cell viability and in vivo animal testing revealed that GDHCP had a stronger anticancer effect than GD and GHCP even though there were no significant differences. Body weight measurement and histological evaluations demonstrated that the drug-loaded GC hydrogels had biocompatibility without cardiotoxicity or nephrotoxicity. These results suggested that GDHCP could be a good platform as a local drug-delivery system for clinical use in OSA treatment.
The Effect of the Antioxidant Activity of Plant Extracts on the Properties of Gold Nanoparticles
Authors: Stozhko Natalia Yu. , Bukharinova Maria A. , Khamzina Ekaterina I. , Tarasov Aleksey V. , Vidrevich Marina B. , Brainina Khiena Z.
Published: November 2019

Synthesis of gold nanoparticles (phyto-AuNPs) with the use of leaf extracts (phytosynthesis) is based on the concept of Green Chemistry. The present study is conducted to discuss how antioxidant activity (AOA) of extracts from plant leaves impacts on the kinetics of phytosynthesis, the size of the formed nanoparticles, and the stability of their nanosuspensions. Results show that the formation rate of phyto-AuNPs suspensions accelerate due to the increase in the AOA of the extracts. Accompanying the use of transmission electron microscopy (TEM), UV-Vis-spectrophotometry and dynamic light scattering (DLS), it also has been found that higher AOA of the extracts leads to a decrease in the size of phyto-AuNPs, an increase in the fraction of small (d ≤ 5 nm), and a decrease in the fraction of large (d ≥ 31–50 nm) phyto-AuNPs, as well as an increase in the zeta potential in absolute value. Phyto-AuNPs suspensions synthesized with the use of extracts are more resistant to destabilizing electrolytes and ultrasound, as compared to suspensions synthesized using sodium citrate. Thus, the AOA of the extract is an important parameter for controlling phytosynthesis and predicting the properties of phyto-AuNPs. The proposed approach can be applied to the targeted selection of plant extract that will be used for synthesizing nanoparticles with desired properties.
Micro- and Nanostructures of Agave Fructans to Stabilize Compounds of High Biological Value via Electrohydrodynamic Processing
Authors: Cruz-Salas Carla N. , Prieto Cristina , Calderón-Santoyo Montserrat , Lagarón José M. , Ragazzo-Sánchez Juan A.
Published: November 2019

This study focuses on the use of high degree of polymerization agave fructans (HDPAF) as a polymer matrix to encapsulate compounds of high biological value within micro- and nanostructures by electrohydrodynamic processing. In this work, β-carotene was selected as a model compound, due to its high sensitivity to temperature, light and oxygen. Ultrafine fibers from HDPAF were obtained via this technology. These fibers showed an increase in fiber diameter when containing β-carotene, an encapsulation efficiency (EE) of 95% and a loading efficiency (LE) of 85%. The thermogravimetric analysis (TGA) showed a 90 °C shift in the β-carotene decomposition temperature with respect to its independent analysis, evidencing the HDPAF thermoprotective effect. Concerning the HDPAF photoprotector effect, only 21% of encapsulated β-carotene was lost after 48 h, while non-encapsulated β-carotene oxidized completely after 24 h. Consequently, fructans could be a feasible alternative to replace synthetic polymers in the encapsulation of compounds of high biological value.
Facile Synthesis of Methylammonium Lead Iodide Perovskite with Controllable Morphologies with Enhanced Luminescence Performance
Authors: Wang Tao , Zhang Huafang , Hou Sumin , Zhang Yan , Li Quanjun , Zhang Zhenlong , Gao Huiping , Mao Yanli
Published: November 2019

Organic–inorganic hybrid perovskites with well-defined morphology have attracted much attention due to their unique photophysical properties. However, controlling the morphology of nanocrystalline perovskite to improve its photoelectric application remains a challenge. In this article, using a modified solution deposition method, we successfully synthesized uniform methylammonium lead iodide (MAPbI3) nanoplates, nanocubes, and nanorods and investigated the effect of morphology on the photoelectric properties of these materials. We found that the morphology can be controlled by regulating the amounts of reactant methylammonium iodide (MAI) and the rate at which MAPbI3 precursor is added into toluene solution, and that the corresponding size distributions can be optimized by tuning the final vacuum-drying temperature. The morphology has an obvious effect on the bandgap optimization and fluorescence enhancement of MAPbI3, and the nanoplates exhibit stronger photoluminescence intensity and have a longer carrier lifetime than nanocubes and nanorods. The results show that the morphologies of MAPbI3 perovskite nanocrystals can be controlled by tuning the synthesizing conditions, and the MAPbI3 perovskite nanocrystals with special morphology can be used in special nanosize optoelectronic devices.
External Field-Controlled Ablation: Magnetic Field
Authors: Maksimovic Jovan , Ng Soon Hock , Katkus Tomas , Cowie Bruce C. C. , Juodkazis Saulius
Published: November 2019

The femtosecond laser ablation of silicon amidst an externally applied magnetic field in different orientations was investigated with respect to the scanning direction and polarisation of the laser beam, by observation of ablation patterns and debris displacement in a range of fluences, magnetic fields strengths, and geometries. Ultra-short ∼ 230 fs laser pulses of 1030 nm wavelengths were utilised in the single and multi-pulse irradiation modes. Ablation with an externally applied magnetic B-field B e x t ≈ 0.15 T was shown to strongly affect debris formation and deposition. The mechanism of surface plasmon polariton (SPP) wave can explain the ablated periodic patterns observed with alignment along the magnetic field lines. The application potential of external field controlled ablation is discussed.
All-Inorganic Perovskite Solar Cells Based on CsPbIBr2 and Metal Oxide Transport Layers with Improved Stability
Authors: Yang Jien , Zhang Qiong , Xu Jinjin , Liu Hairui , Qin Ruiping , Zhai Haifa , Chen Songhua , Yuan Mingjian
Published: November 2019

Despite the successful improvement in the power conversion efficiency (PCE) of perovskite solar cells (PSCs), the issue of instability is still a serious challenge for their commercial application. The issue of the PSCs mainly originates from the decomposition of the organic–inorganic hybrid perovskite materials, which will degrade upon humidity and suffer from the thermal environment. In addition, the charge transport layers also influence the stability of the whole devices. In this study, inorganic transport layers are utilized in an inverted structure of PSCs employing CsPbIBr2 as light absorbent layer, in which nickel oxide (NiOx) and cerium oxide (CeOx) films are applied as the hole transport layer (HTL) and the electron transport layer (ETL), respectively. The inorganic transport layers are expected to protect the CsPbIBr2 film from the contact of moisture and react with the metal electrode, thus preventing degradation. The PSC with all inorganic components, inorganic perovskite and inorganic transport layers demonstrates an initial PCE of 5.60% and retains 5.56% after 600 s in ambient air at maximum power point tracking.
Bacterial Nanocellulose and Its Surface Modification by Glycidyl Methacrylate and Ethylene Glycol Dimethacrylate. Incorporation of Vancomycin and Ciprofloxacin
Authors: Vismara Elena , Bernardi Andrea , Bongio Chiara , Farè Silvia , Pappalardo Salvatore , Serafini Andrea , Pollegioni Loredano , Rosini Elena , Torri Giangiacomo
Published: November 2019

Among nanocelluloses, bacterial nanocellulose (BNC) has proven to be a promising candidate in a range of biomedical applications, from topical wound dressings to tissue-engineering scaffolds. Chemical modifications and incorporation of bioactive molecules have been obtained, further increasing the potential of BNC. This study describes the incorporation of vancomycin and ciprofloxacin in BNC and in modified BNC to afford bioactive BNCs suitable for topical wound dressings and tissue-engineering scaffolds. BNC was modified by grafting glycidylmethacrylate (GMA) and further cross-linking with ethylene glycol dimethacrylate (EGDMA) with the formation of stable C–C bonds through a radical Fenton-type process that involves generation of cellulose carbon centred radicals scavenged by methacrylate structures. The average molar substitution degree MS (MS = methacrylate residue per glucose unit, measured by Fourier transform infrared (FT–IR) analysis) can be modulated in a large range from 0.1 up to 3. BNC-GMA, BNC-EGDMA and BNC-GMA-EGDMA maintain the hydrogel status until MS reaches the value of 1. The mechanical stress resistance increase of BNC-GMA and BNC-GMA-EGDMA of MS around 0.8 with respect to BNC suggests that they can be preferred to BNC for tissue-engineering scaffolds in cases where the resistance plays a crucial role. BNC, BNC-GMA, BNC-EGDMA and BNC-GMA-EGDMA were loaded with vancomycin (VC) and ciprofloxacin (CP) and submitted to release experiments. BNC-GMA-EGDMA of high substitution degree (0.7–1) hold up to 50 percentage of the loaded vancomycin and ciprofloxacin amount, suggesting that they can be further investigated for long-term antimicrobial activity. Furthermore, they were not colonized by Staphylococcus aureus (S.A.) and Klebsiella pneumonia (K.P.). Grafting and cross-linking BNC modification emerges from our results as a good choice to improve the BNC potential in biomedical applications like topical wound dressings and tissue-engineering scaffolds.
Inhibitory Effects of Cu2O/SiO2 on the Growth of Microcystis aeruginosa and Its Mechanism
Authors: Fan Gongduan , Bao Minchen , Wang Bo , Wu Shimin , Luo Lingxi , Li Binhui , Lin Jiuhong
Published: November 2019

In this study, a novel nanomaterial Cu2O/SiO2 was synthesized based on nano-SiO2, and the inhibitory effects of different concentrations of Cu2O/SiO2 on the growth of Microcystis aeruginosa (M. aeruginosa) were studied. At the same time, the mechanism of Cu2O/SiO2 inhibiting the growth of M. aeruginosa was discussed from the aspects of Cu2+ release, chlorophyll a destruction, oxidative damage, total protein, and the phycobiliprotein of algae cells. The results showed that low doses of Cu2O/SiO2 could promote the growth of M. aeruginosa. When the concentration of Cu2O/SiO2 reached 10 mg/L, it exhibited the best inhibitory effect on M. aeruginosa, and the relative inhibition rate reached 294% at 120 h. In terms of the algae inhibition mechanism, Cu2O/SiO2 will release Cu2+ in the solution and induce metal toxicity to algae cells. At the same time, M. aeruginosa might suffer oxidative damage by the free radicals, such as hydroxyl radicals released from Cu2O/SiO2, affecting the physiological characteristics of algae cells. Moreover, after the addition of Cu2O/SiO2, a decrease in the content of chlorophyll a, total soluble protein, and phycobiliprotein was found, which eventually led to the death of M. aeruginosa. Therefore, Cu2O/SiO2 can be used as an algaecide inhibitor for controlling harmful cyanobacteria blooms.
Lifestyle Interventions with a Focus on Nutritional Strategies to Increase Cardiorespiratory Fitness in Chronic Obstructive Pulmonary Disease, Heart Failure, Obesity, Sarcopenia, and Frailty
Authors: Billingsley Hayley E. , Rodriguez-Miguelez Paula , Del Buono Marco Giuseppe , Abbate Antonio , Lavie Carl J. , Carbone Salvatore
Published: November 2019

Cardiorespiratory fitness (CRF) is an independent predictor for all-cause and disease-specific morbidity and mortality. CRF is a modifiable risk factor, and exercise training and increased physical activity, as well as targeted medical therapies, can improve CRF. Although nutrition is a modifiable risk factor for chronic noncommunicable diseases, little is known about the effect of dietary patterns and specific nutrients on modifying CRF. This review focuses specifically on trials that implemented dietary supplementation, modified dietary pattern, or enacted caloric restriction, with and without exercise training interventions, and subsequently measured the effect on peak oxygen consumption (VO2) or surrogate measures of CRF and functional capacity. Populations selected for this review are those recognized to have a reduced CRF, such as chronic obstructive pulmonary disease, heart failure, obesity, sarcopenia, and frailty. We then summarize the state of existing knowledge and explore future directions of study in disease states recently recognized to have an abnormal CRF.
Serum Proteomic Analysis Reveals Vitamin D-Binding Protein (VDBP) as a Potential Biomarker for Low Bone Mineral Density in Mexican Postmenopausal Women
Authors: Martínez-Aguilar Mayeli M. , Aparicio-Bautista Diana I. , Ramírez-Salazar Eric G. , Reyes-Grajeda Juan P. , De la Cruz-Montoya Aldo H. , Antuna-Puente Bárbara , Hidalgo-Bravo Alberto , Rivera-Paredez Berenice , Ramírez-Palacios Paula , Quiterio Manuel , Valdés-Flores Margarita , Salmerón Jorge , Velázquez-Cruz Rafael
Published: November 2019

Osteoporosis is a skeletal disease mainly affecting women over 50 years old and it represents a serious public health problem because of the high socioeconomic burden. This disease is characterized by deterioration of bone microarchitecture, low bone mineral density (BMD), and increased risk of fragility fractures. This study aimed to identify serum useful proteins as biomarkers for the diagnosis and/or prognosis of osteoporosis and fracture risk. We collected 446 serum samples from postmenopausal women aged ≥45 years old. Based on the BMD measurement, we classified the participants into three groups: osteoporotic, osteopenic, and normal. In an initial discovery stage, we conducted a proteomic approach using two-dimensional differential gel electrophoresis (2D-DIGE). The peptides into the spots of interest were identified through matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF/TOF). Enzyme-linked immunosorbent assay (ELISA) was performed to validate the proteins of interest. We identified 27 spots of interest when comparing low BMD versus normal BMD postmenopausal women. Based on their relevance in bone metabolism, we analyzed three proteins: ceruloplasmin (CP), gelsolin (GSN), and vitamin D-binding protein (VDBP). Our results demonstrated that low serum VDBP levels correlate with low BMD (osteopenic and osteoporotic). Therefore, VDBP could be considered as a novel, potential, and non-invasive biomarker for the early detection of osteoporosis.
Effect of Structural Individual Low-FODMAP Dietary Advice vs. Brief Advice on a Commonly Recommended Diet on IBS Symptoms and Intestinal Gas Production
Authors: Patcharatrakul Tanisa , Juntrapirat Akarawut , Lakananurak Narisorn , Gonlachanvit Sutep
Published: November 2019

A low fermentable oligosaccharide, disaccharide, monosaccharide, and polyol (FODMAP) diet has been recommended for irritable bowel syndrome (IBS) patients. This study compared the efficacy of two types of dietary advice: (1) brief advice on a commonly recommended diet (BRD), and (2) structural individual low-FODMAP dietary advice (SILFD). Patients with moderate-to-severe IBS were randomized to BRD or SILFD groups. Gastrointestinal symptoms, 7-day food diaries, and post-prandial breath samples were evaluated. The SILFD included (1) identifying high-FODMAP items from the diary, (2) replacing high-FODMAP items with low-FODMAP ones by choosing from the provided menu. The BRD included reducing traditionally recognized foods that cause bloating/abdominal pain and avoidance of large meals. Responders were defined as those experiencing a ≥30% decrease in the average of daily worst abdominal pain/discomfort after 4 weeks. Sixty-two patients (47 F, age 51 ± 14 years), BRD (n = 32) or SILFD (n = 30), completed the studies. Eighteen (60%) patients in SILFD vs. 9 (28%) in the BRD group fulfilled responder criteria (p = 0.001). Global IBS symptom severity significantly improved and the number of high-FODMAP items consumed was significantly decreased after SILFD compared to BRD. Post-prandial hydrogen (H2) breath production after SILFD was significantly lower than was seen after BRD (p < 0.001). SILFD was more effective than BRD. This advice method significantly reduced FODMAP intake, improved IBS symptoms, and lowered intestinal H2 production.
Interactions between DRD2/ANKK1 TaqIA Polymorphism and Dietary Factors Influence Plasma Triglyceride Concentrations in Diabetic Patients from Western Mexico: A Cross-sectional Study
Authors: Ramos-Lopez Omar , Mejia-Godoy Roberto , Frías-Delgadillo Kevin J. , Torres-Valadez Rafael , Flores-García Aurelio , Sánchez-Enríquez Sergio , Aguiar-García Pedro , Martínez-López Erika , Zepeda-Carrillo Eloy A.
Published: November 2019

This study aimed to screen relevant interactions between DRD2/ANKK1 TaqIA polymorphism and dietary intakes with reference to phenotypical features in patients with T2D from western Mexico. In this cross-sectional study, a total of 175 T2D patients were enrolled. Dietary intake was evaluated using 3-day food records and appropriate software. Glycemic and blood lipid profiles were measured by standardized methods. Genotyping of the DRD2/ANKK1 TaqIA polymorphism was performed by the RFLP method. Gene-diet interactions regarding anthropometric and metabolic phenotypes were screened by adjusted multiple linear regression analyses. Genotype frequencies of the DRD2/ANKK1 TaqIA polymorphism were A1A1 (16.0%), A1A2 (52.6%), and A2A2 (31.4%). Statistically significant interactions between the DRD2/ANKK1 TaqIA genotypes and dietary factors in relation to blood triglyceride (TG) levels were found. Carriers of the A1 allele (A1A1 homozygotes plus A1A2 heterozygotes) were protected from TG increases by maltose intake (P int. = 0.023). Instead, A2A2 homozygotes were susceptible to TG rises through consumptions of total fat (P int. = 0.041), monounsaturated fatty acids (P int. = 0.001), and dietary cholesterol (P int. = 0.019). This study suggests that the interactions between DRD2/ANKK1 TaqIA polymorphism and dietary factors (sugar and fats) influence TG levels in diabetic patients.
First Broad Screening of Allelopathic Potential of Wild and Cultivated Plants in Turkey
Authors: Isin Ozkan Tugba Gonca , Akalin Urusak Emine , Appiah Kwame Sarpong , Fujii Yoshiharu
Published: November 2019

Turkey has one of the richest plant diversities in the Mediterranean region. In the current literature, no broad screening has been conducted on the potential allelopathy of plants from Turkey. This study aimed to evaluate the allelopathic activity of a large number of plants from Turkey for the first time and to determine the species with significant plant growth inhibitory potentials by bioassay. Dried samples of different plant parts were collected from local herbalists. The sandwich method was used to evaluate the potential allelopathy of 126 medicinal plants belonging to 55 families. The results of lettuce radicle and hypocotyl growth for 10 and 50 mg sample treatment conformed to normal distribution. Significant inhibition on lettuce radicle elongation with 10 mg sample was observed in 40 species, out of which 27 species showed over 50% inhibitory activity. The results suggested that these species could contain potential inhibitory compounds against lettuce radicle or hypocotyl growth. The calyxes of Hibiscus sabdariffa (3.2% of control) and the seeds of Prunus dulcis (5.7% of control) showed the most potent growth inhibitory activity on lettuce radicle elongation. The potential plant growth inhibitory effects of these plants, together with the fruits of Rhus coriaria and seeds of Prunus mahaleb, have been reported in this study for the first time. All these plants are medicinal, and the results hereby presented provide essential information about the allelopathic effects of medicinal plants from Turkey.
Effect of DMPA and Molecular Weight of Polyethylene Glycol on Water-Soluble Polyurethane
Authors: Wondu Eyob , Oh Hyun Woo , Kim Jooheon
Published: November 2019

In this study water-soluble polyurethane (WSPU) was synthesized from isophorone diisocyanate (IPDI), and polyethylene glycol (PEG), 2-bis(hydroxymethyl) propionic acid or dimethylolpropionic acid (DMPA), butane-1,4-diol (BD), and triethylamine (TEA) using an acetone process. The water solubility was investigated by solubilizing the polymer in water and measuring the contact angle and the results indicated that water solubility and contact angle tendency were increased as the molecular weight of the soft segment decreased, the amount of emulsifier was increased, and soft segment to hard segment ratio was lower. The contact angle of samples without emulsifier was greater than 87°, while that of with emulsifier was less than 67°, indicating a shift from highly hydrophobic to hydrophilic. The WSPU was also analyzed using Fourier transform infrared spectroscopy (FT-IR) to identify the absorption of functional groups and further checked by X-ray photoelectron spectroscopy (XPS). The molecular weight of WSPU was measured using size-exclusion chromatography (SEC). The structure of the WSPU was confirmed by nuclear magnetic resonance spectroscopy (NMR). The thermal properties of WSPU were analyzed using thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC).
A Novel Application of Electroactive Polyimide Doped with Gold Nanoparticles: As a Chemiresistor Sensor for Hydrogen Sulfide Gas
Authors: Padua Lee Marvin G. , Yeh Jui-Ming , Santiago Karen S.
Published: November 2019

This research paper presents a new application of electroactive polyimide doped with gold nanoparticles (PI/AuNPs) as a chemiresistor sensor for detecting hydrogen sulfide gas. The synthesis of PI/AuNPs was done in a simple 3-step process of polymerization using the as prepared amine-capped aniline trimer (ACAT), followed by imidization, and doping. Spectral analyses via FTIR, LC-MS and 1H-NMR confirmed the formation of amine-capped aniline trimer with a MW of 288 g mol−1. Comparison of ACAT, BSAA, and PI FTIR spectra showed successful polymerization of the last, while XRD validated the incorporation of metal nanoparticles onto the polymer matrix, showing characteristic diffraction peaks corresponding to gold. Furthermore, TEM, and FE-SEM revealed the presence of well-dispersed Au nanoparticles with an average diameter of about 60 nm. The electroactive PI/AuNPs-based sensor showed a sensitivity of 0.29% ppm−1 H2S at a linear concentration range of 50 to 300 ppm H2S (r = 0.9777). The theoretical limit of detection was found at 0.142 ppm or 142 ppb H2S gas. The sensor provided a stable response reading at an average response time of 43 ± 5 s, which was easily recovered after an average time of 99 ± 5 s. The sensor response was highly repeatable and reversible, with RSD values of 8.88%, and 8.60%, respectively. Compared with the performance of the conventional conducting polyaniline also doped with gold nanoparticles (PANI/AuNPs), the fabricated electroactive PI/AuNPs exhibited improved sensing performance making it a potential candidate in monitoring H2S in the environment and for work-related safety.
Complex Diffractive Optical Elements Stored in Photopolymers
Authors: Fernández Roberto , Gallego Sergi , Márquez Andrés , Neipp Cristian , Calzado Eva , Francés Jorge , Morales-Vidal Marta , Beléndez Augusto
Published: November 2019

We study the recording of complex diffractive elements, such as achromatic lenses, fork gratings or axicons. Using a 3-D diffusion model, previously validated, we are able to predict the behavior of photopolymer during recording. The experimental recording of these complex elements is possible thanks to a new generation spatial light modulator capable of generating periodic and aperiodic profiles. Both experimental and theoretical are analyzed and compared. The results show not only the good response of theoretical model to predict the behavior of the materials, but also the viability of photopolymers to store these kind of elements.
Effect of Polymer Demixed Nanotopographies on Bacterial Adhesion and Biofilm Formation
Authors: Fleming George , Aveyard Jenny , Fothergill Joanne L. , McBride Fiona , Raval Rasmita , D’Sa Raechelle A.
Published: November 2019

As the current global threat of antimicrobial resistance (AMR) persists, developing alternatives to antibiotics that are less susceptible to resistance is becoming an urgent necessity. Recent advances in biomaterials have allowed for the development and fabrication of materials with discrete surface nanotopographies that can deter bacteria from adhering to their surface. Using binary polymer blends of polystyrene (PS), poly(methyl methacrylate) (PMMA) and polycaprolactone (PCL) and varying their relative concentrations, PS/PCL, PS/PMMA and PCL/PMMA polymer demixed thin films were developed with nanoisland, nanoribbon and nanopit topographies. In the PS/PCL system, PS segregates to the air-polymer interface, with the lower solubility PCL preferring the substrate-polymer interface. In the PS/PMMA and PCL/PMMA systems, PMMA prefers the air-polymer interface due to its greater solubility and lower surface energy. The anti-adhesion efficacy of the demixed films were tested against Pseudomonas aeruginosa (PA14). PS/PCL and PCL/PMMA demixed films showed a significant reduction in cell counts adhered on their surfaces compared to pure polymer control films, while no reduction was observed in the counts adhered on PS/PMMA demixed films. While the specific morphology did not affect the adhesion, a relationship between bacterial cell and topographical surface feature size was apparent. If the surface feature was smaller than the cell, then an anti-adhesion effect was observed; if the surface feature was larger than the cell, then the bacteria preferred to adhere.