bluuebunny/crossref_metadata_2025 huggingface dataset:
A Theoretical Treatment of THz Resonances in Semiconductor GaAs p–n Junctions
Authors: Janipour Mohsen , Misirlioglu I. Burc , Sendur Kursat
Published: July 2019

Semiconductor heterostructures are suitable for the design and fabrication of terahertz (THz) plasmonic devices, due to their matching carrier densities. The classical dispersion relations in the current literature are derived for metal plasmonic materials, such as gold and silver, for which a homogeneous dielectric function is valid. Penetration of the electric fields into semiconductors induces locally varying charge densities and a spatially varying dielectric function is expected. While such an occurrence renders tunable THz plasmonics a possibility, it is crucial to understand the conditions under which propagating resonant conditions for the carriers occur, upon incidence of an electromagnetic radiation. In this manuscript, we derive a dispersion relation for a p–n heterojunction and apply the methodology to a GaAs p–n junction, a material of interest for optoelectronic devices. Considering symmetrically doped p- and n-type regions with equal width, the effect of certain parameters (such as doping and voltage bias) on the dispersion curve of the p–n heterojunction were investigated. Keeping in sight the different effective masses and mobilities of the carriers, we were able to obtain the conditions that yield identical dielectric functions for the p- and n-regions. Our results indicated that the p–n GaAs system can sustain propagating resonances and can be used as a layered plasmonic waveguide. The conditions under which this is feasible fall in the frequency region between the transverse optical phonon resonance of GaAs and the traditional cut-off frequency of the diode waveguide. In addition, our results indicated when the excitation was slightly above the phonon resonance frequency, the plasmon propagation attained low-loss characteristics. We also showed that the existence or nonexistence of the depletion zone between the p- and n- interfaces allowed certain plasmon modes to propagate, while others decayed rapidly, pointing out the possibility for a design of selective filters.
Surface Modification of Polycarbonate by an Atmospheric Pressure Argon Microwave Plasma Sheet
Authors: Czylkowski Dariusz , Hrycak Bartosz , Sikora Andrzej , Moczała-Dusanowska Magdalena , Dors Mirosław , Jasiński Mariusz
Published: July 2019

The specific properties of an atmospheric pressure plasma make it an attractive tool for the surface treatment of various materials. With this in mind, this paper presents the results of experimental investigations of a polycarbonate (PC) material surface modification using this new type of argon microwave (2.45 GHz) plasma source. The uniqueness of the new plasma source lies in the shape of the generated plasma—in contrast to other microwave plasma sources, which usually provide a plasma in the form of a flame or column, the new ones provides a plasma in the shape of a regular plasma sheet. The influence of the absorbed microwave power and the number of scans on the changes of the wettability and morphological and mechanical properties of the plasma-treated PC samples was investigated. The mechanical properties and changes in roughness of the samples were measured by the use of atomic force microscopy (AFM). The wettability of the plasma-modified samples was tested by measuring the water contact angle. In order to confirm the plasma effect, each of the above-mentioned measurements was performed before and after plasma treatment. All experimental tests were performed with an argon of flow rate up to 20 L/min and the absorbed microwave power ranged from 300 to 850 W. The results prove the capability of the new atmospheric pressure plasma type in modifying the morphological and mechanical properties of PC surfaces for industrial applications.
Estimation of Hydration Degree of Blended Cements with the Help of k-Values
Authors: Reiterman Pavel , Holčapek Ondřej , Davidová Vendula , Jaskulski Roman , Keppert Martin
Published: July 2019

The growing utilization of various mineral additives in the building industry has caused concern worldwide to reduce the emissions of carbon dioxide from Portland cement (OPC) production. The present paper is focused on the determination of the degree of hydration of blended binding systems based on Portland cement. Blast furnace slag, fly ash, and ceramic powder are used in the study; they are applied by 12.5 wt.% up to 50% of OPC replacement. The evolution of the hydration process is monitored using thermogravimetry in selected time intervals to determine the degree of hydration; its ultimate value is obtained from numerical estimation using the Michaelis-Menten equation. However, due to the application of active mineral additives, the correction in terms of equivalent binder is conducted. Corrected values of the degree of hydration exhibit good fit with compressive strength.
A Study of Multivalent q-starlike Functions Connected with Circular Domain
Authors: Shi Lei , Khan Qaiser , Srivastava Gautam , Liu Jin-Lin , Arif Muhammad
Published: July 2019

Starlike functions have gained popularity both in literature and in usage over the past decade. In this paper, our aim is to examine some useful problems dealing with q-starlike functions. These include the convolution problem, sufficiency criteria, coefficient estimates, and Fekete–Szegö type inequalities for a new subfamily of analytic and multivalent functions associated with circular domain. In addition, we also define and study a Bernardi integral operator in its q-extension for multivalent functions. Furthermore, we will show that the class defined in this paper, along with the obtained results, generalizes many known works available in the literature.
Compatible Algebras with Straightening Laws on Distributive Lattices
Authors: Bănaru Daniel , Ene Viviana
Published: July 2019

We characterize the finite distributive lattices on which there exists a unique compatible algebra with straightening laws.
An Optimal Eighth-Order Family of Iterative Methods for Multiple Roots
Authors: Akram Saima , Zafar Fiza , Yasmin Nusrat
Published: July 2019

In this paper, we introduce a new family of efficient and optimal iterative methods for finding multiple roots of nonlinear equations with known multiplicity ( m ≥ 1 ) . We use the weight function approach involving one and two parameters to develop the new family. A comprehensive convergence analysis is studied to demonstrate the optimal eighth-order convergence of the suggested scheme. Finally, numerical and dynamical tests are presented, which validates the theoretical results formulated in this paper and illustrates that the suggested family is efficient among the domain of multiple root finding methods.
A Convergence Theorem for the Nonequilibrium States in the Discrete Thermostatted Kinetic Theory
Authors: Bianca Carlo , Menale Marco
Published: July 2019

The existence and reaching of nonequilibrium stationary states are important issues that need to be taken into account in the development of mathematical modeling frameworks for far off equilibrium complex systems. The main result of this paper is the rigorous proof that the solution of the discrete thermostatted kinetic model catches the stationary solutions as time goes to infinity. The approach towards nonequilibrium stationary states is ensured by the presence of a dissipative term (thermostat) that counterbalances the action of an external force field. The main result is obtained by employing the Discrete Fourier Transform (DFT).
Construction and Application of Nine-Tic B-Spline Tensor Product SS
Authors: Ghaffar Abdul , Iqbal Mudassar , Bari Mehwish , Muhammad Hussain Sardar , Manzoor Raheela , Sooppy Nisar Kottakkaran , Baleanu Dumitru
Published: July 2019

In this paper, we propose and analyze a tensor product of nine-tic B-spline subdivision scheme (SS) to reduce the execution time needed to compute the subdivision process of quad meshes. We discuss some essential features of the proposed SS such as continuity, polynomial generation, joint spectral radius, holder regularity and limit stencil. Some results of the SS using surface modeling with the help of computer programming are shown.
Proteomic Advances in Glial Tumors through Mass Spectrometry Approaches
Authors: Pirlog Radu , Susman Sergiu , Iuga Cristina Adela , Florian Stefan Ioan
Published: July 2019

Being the fourth leading cause of cancer-related death, glial tumors are highly diverse tumor entities characterized by important heterogeneity regarding tumor malignancy and prognosis. However, despite the identification of important alterations in the genome of the glial tumors, there remains a gap in understanding the mechanisms involved in glioma malignancy. Previous research focused on decoding the genomic alterations in these tumors, but due to intricate cellular mechanisms, the genomic findings do not correlate with the functional proteins expressed at the cellular level. The development of mass spectrometry (MS) based proteomics allowed researchers to study proteins expressed at the cellular level or in serum that may provide new insights on the proteins involved in the proliferation, invasiveness, metastasis and resistance to therapy in glial tumors. The integration of data provided by genomic and proteomic approaches into clinical practice could allow for the identification of new predictive, diagnostic and prognostic biomarkers that will improve the clinical management of patients with glial tumors. This paper aims to provide an updated review of the recent proteomic findings, possible clinical applications, and future research perspectives in diffuse astrocytic and oligodendroglial tumors, pilocytic astrocytomas, and ependymomas.
The Measurement of Elderly Volunteers’ Optic Nerve Sheath Diameters by Ocular Ultrasonography
Authors: Avci Mustafa , Kozaci Nalan , Komut Erdal , Komut Seval , Caliskan Gulsum , Tulubas Gul
Published: July 2019

Background and objectives: The optic nerve is a component of the central nervous system, and the optic nerve sheath is connected to the subarachnoid space. For this reason, intracranial pressure (ICP) increases are directly transmitted to the optic nerve sheath. Knowing the normal optic nerve sheath diameter (ONSD) range in a healthy population is necessary to interpret this measurement as a sign of intracranial pressure in clinical practice and research. In this study, we aimed to determine the standard ONSD value in healthy adultsaged65 years of age or older who had not previously been diagnosed with a disease that could increase the ICP. Materials and Methods: The right and left ONSD values and ONSD differences were compared, according to the gender of the patients. The patients were divided into 3 groups, according to their age. The age groups were assigned as follows: Group 1: 65–74 years of age; Group 2: 75–84 years of age; and Group 3: 85 years of age or older. The ONSDs and the ONSD difference between the left and right eyes of Group 1, Group 2 and Group 3 were compared. Results: The study included 195 volunteers. The mean ONSD of both eyes was 4.16±0.69 mm, and the difference between the ONSD of the left and right eyes was 0.16±0.18 mm. There was no difference between genders in terms of right ONSD, left ONSD, mean ONSD and ONSD difference between the left and right eyes. There was no correlation between age and ONSD and ONSD difference. When the age groups and ONSD were compared, no difference was found between the groups. Conclusions: In conclusion, the ONSDs of both eyes do not vary with age in healthy adults aged65 years or older. ONSD does not vary between genders. The calculation of ONSD difference can be used to determine ICP increase.
From Statistical Correlations to Stochasticity and Size Effects in Sub-Micron Crystal Plasticity
Authors: Song Hengxu , Papanikolaou Stefanos
Published: July 2019

Metals in small volumes display a strong dependence on initial conditions, which translates into size effects and stochastic mechanical responses. In the context of crystal plasticity, this amounts to the role of pre-existing dislocation configurations that may emerge due to prior processing. Here, we study a minimal but realistic model of uniaxial compression of sub-micron finite volumes. We show how the statistical correlations of pre-existing dislocation configurations may influence the mechanical response in multi-slip crystal plasticity, in connection to the finite volume size and the initial dislocation density. In addition, spatial dislocation correlations display evidence that plasticity is strongly influenced by the formation of walls composed of bound dislocation dipoles.
Cooperative Effect of Li Content and Equal-Channel Angular Pressing on Microstructure and Mechanical Properties of Al-Mg-Li Alloy
Authors: Yuan Ting , Jiang Jinghua , Wu Yuna , Yuan Zhipeng , Ma Aibin , Yuan Yuchun
Published: July 2019

This paper investigated the cooperative effects of Li addition and warm Equal Channel Angular Pressing (ECAP) on improving the mechanical properties of an Al-Mg-Li alloy for further weight reduction. The results showed that more Li addition could obviously refine the grains of the as-cast alloy and reduce its density value to only 2.37 g/cm3 when Li content reached 2.5% (about 12.6% lighter than commercial Al alloys). It also had a pronounced influence on the precipitations in the Al-5.5Mg-xLi-0.1Zr alloy, i.e., the number density and size of Al2MgLi and δ’-Al3Li phases. The yield strength of the as-cast alloy was increased with increasing Li, but the elongation deteriorated due to primary network intergranular Al2MgLi and more δ’ particles in the high Li-containing alloy. The warm multi-pass ECAP process was found to simultaneously improve the strength and ductility of the Al-Mg-Li alloys, and greatly alleviate the detrimental effect of Li addition on the elongation, thereby making the ultrafine-grained (UFG) alloys, a good combination of lightweight and high performance, very attractive for aerospace applications for much higher specific strength than both Al matrix composites and Mg alloys.
Electrochemical and Optical Biosensors for the Detection of Campylobacter and Listeria: An Update Look
Authors: Vizzini Priya , Braidot Matteo , Vidic Jasmina , Manzano Marisa
Published: July 2019

Foodborne safety has aroused tremendous research interest in recent years because of a global public health problem. The rapid and precise detection of foodborne pathogens can reduce significantly infection diseases and save lives by the early initiation of an effective treatment. This review highlights current advances in the development of biosensors for detection of Campylobacter spp. and Listeria monocytogenes that are the most common causes of zoonosis. The consumption of pathogen contaminated food is responsible for humans hospitalization and death. The attention focused on the recognition elements such as antibodies (Ab), DNA probes and aptamers able to recognize cells, amplicons, and specific genes from different samples like bacteria, food, environment and clinical samples. Moreover, the review focused on two main signal-transducing mechanisms, i.e., electrochemical, measuring an amperometric, potentiometric and impedimetric signal; and optical, measuring a light signal by OLED (Organic Light Emitting Diode), SPR (Surface Plasmon Resonance), and Optical fiber. We expect that high-performance of devices being developed through basic research will find extensive applications in environmental monitoring, biomedical diagnostics, and food safety.
3D Printing Breast Tissue Models: A Review of Past Work and Directions for Future Work
Authors: Cleversey Chantell , Robinson Meghan , Willerth Stephanie
Published: July 2019

Breast cancer often results in the removal of the breast, creating a need for replacement tissue. Tissue engineering offers the promise of generating such replacements by combining cells with biomaterial scaffolds and serves as an attractive potential alternative to current surgical repair methods. Such engineered tissues can also serve as important tools for drug screening and provide in vitro models for analysis. 3D bioprinting serves as an exciting technology with significant implications and applications in the field of tissue engineering. Here we review the work that has been undertaken in hopes of generating the recognized in-demand replacement breast tissue using different types of bioprinting. We then offer suggestions for future work needed to advance this field for both in vitro and in vivo applications.
Gemstones of Greece: Geology and Crystallizing Environments
Authors: Voudouris Panagiotis , Mavrogonatos Constantinos , Graham Ian , Giuliani Gaston , Tarantola Alexandre , Melfos Vasilios , Karampelas Stefanos , Katerinopoulos Athanasios , Magganas Andreas
Published: July 2019

In the Hellenides Orogen, minerals of various gem quality occur in various rock types from mainly four tectono-metamorphic units, the Rhodope, Pelagonian, and the Attico-Cycladic massifs, and the Phyllites-Quartzites unit of Crete Island. In crystalline rocks, gemstones are related to both regional metamorphic-metasomatic processes (e.g., gem corundums, Mn-andalusite, thulite/clinothulite, spessartine, titanite, jadeite), and to the formation of late alpine-type fissures, such as, for example, quartz, albite, adularia and titanite. The Tertiary (and Mesozoic) magmatic-hydrothermal environments provide gem-quality sapphire, beryl, garnet, vesuvianite, epidote, fluorite, and SiO2 varieties. The supergene oxidation zone of the Lavrion deposit hosts gem-quality smithsonite and azurite. Coloration in the studied material is either due to various chromophore trace elements present in the crystal structure, or due to inclusions of other mineral phases. Future modern exploration methods combined with gemological investigations (such as treatment and faceting of selected stones), are necessary in order to obtain a better knowledge of the gemstone potential of Greece for its possible exploitation.
Centrifugation Conditions in the L-PRP Preparation Affect Soluble Factors Release and Mesenchymal Stem Cell Proliferation in Fibrin Nanofibers
Authors: de Melo Bruna Alice Gomes , Luzo Ângela Cristina Malheiros , Lana José Fabio Santos Duarte , Santana Maria Helena Andrade
Published: July 2019

Leukocyte and platelet-rich plasma (L-PRP) is an autologous product that when activated forms fibrin nanofibers, which are useful in regenerative medicine. As an important part of the preparation of L-PRP, the centrifugation parameters may affect the release of soluble factors that modulate the behavior of the cells in the nanofibers. In this study, we evaluated the influences of four different centrifugation conditions on the concentration of platelets and leukocytes in L-PRP and on the anabolic/catabolic balance of the nanofiber microenvironment. Human adipose-derived mesenchymal stem cells (h-AdMSCs) were seeded in the nanofibers, and their viability and growth were evaluated. L-PRPs prepared at 100× g and 100 + 400× g released higher levels of transforming growth factor (TGF)-β1 and platelet-derived growth factor (PDGF)-BB due to the increased platelet concentration, while inflammatory cytokines interleukin (IL)-8 and tumor necrosis factor (TNF)-α were more significantly released from L-PRPs prepared via two centrifugation steps (100 + 400× g and 800 + 400× g) due to the increased concentration of leukocytes. Our results showed that with the exception of nanofibers formed from L-PRP prepared at 800 + 400× g, all other microenvironments were favorable for h-AdMSC proliferation. Here, we present a reproducible protocol for the standardization of L-PRP and fibrin nanofibers useful in clinical practices with known platelet/leukocyte ratios and in vitro evaluations that may predict in vivo results.
Site Selective and Efficient Spin Labeling of Proteins with a Maleimide-Functionalized Trityl Radical for Pulsed Dipolar EPR Spectroscopy
Authors: Jassoy J. Jacques , Heubach Caspar A. , Hett Tobias , Bernhard Frédéric , Haege Florian R. , Hagelueken Gregor , Schiemann Olav
Published: July 2019

Pulsed dipolar electron paramagnetic resonance spectroscopy (PDS) in combination with site-directed spin labeling (SDSL) of proteins and oligonucleotides is a powerful tool in structural biology. Instead of using the commonly employed gem-dimethyl-nitroxide labels, triarylmethyl (trityl) spin labels enable such studies at room temperature, within the cells and with single-frequency electron paramagnetic resonance (EPR) experiments. However, it has been repeatedly reported that labeling of proteins with trityl radicals led to low labeling efficiencies, unspecific labeling and label aggregation. Therefore, this work introduces the synthesis and characterization of a maleimide-functionalized trityl spin label and its corresponding labeling protocol for cysteine residues in proteins. The label is highly cysteine-selective, provides high labeling efficiencies and outperforms the previously employed methanethiosulfonate-functionalized trityl label. Finally, the new label is successfully tested in PDS measurements on a set of doubly labeled Yersinia outer protein O (YopO) mutants.
Iridium(III) Complexes Targeting Apoptotic Cell Death in Cancer Cells
Authors: Ma Dik-Lung , Wu Chun , Wu Ke-Jia , Leung Chung-Hang
Published: July 2019

Targeting apoptosis is a principal strategy in the design of anticancer drugs. In recent years, non-platinum-based scaffolds have been exploited as viable candidates for the exploitation of anticancer agents with potentially lower toxicity than the widely used cisplatin analogues. This review highlights the latest advances in developing iridium(III) complexes as anticancer agents that act particularly via targeting apoptotic cell death in cancer cells.
Removal of Reactive Dyes in Textile Effluents by Catalytic Ozonation Pursuing on-Site Effluent Recycling
Authors: Hu Enling , Shang Songmin , Chiu Ka-Lok
Published: July 2019

The textile wash-off process consumes substantial amounts of water, which generates large volumes of wastewater that pose potential pollution issues for the environment. In the present study, catalytic ozonation was applied to degrade residual dyes present in rinsing effluents from wash-off processes towards the aim of recycling the waste effluents. A magnetic catalyst was prepared for promoting dye degradation by catalytic ozonation. Via a hydrothermal reaction, highly magnetic manganese ferrite (MnFe2O4) particles were successfully loaded on carbon aerogel (CA) materials (MnFe2O4@CA). The results showed that the developed catalyst strikingly promoted the degradation of dye contaminants by catalytic ozonation, in terms of color removal and reduction of chemical oxidation demand (COD) in rinsing effluents. COD removal efficiency in catalytic ozonation was enhanced by 25% when compared with that achieved by ozonation alone under the same treatment conditions. Moreover, we confirmed that after catalytic ozonation, the rinsing effluents could be recycled to replace fresh water without any evident compromise in the color quality of fabrics. The color difference (ΔEcmc(2:1)) between fabrics treated with recycled effluents and water was not more than 1.0, suggesting that the fabrics treated with recycled effluents displayed acceptable color reproducibility. Although colorfastness and color evenness of fabrics treated with recycled effluents were slightly poorer than those of fabrics treated with water, they were still within the acceptable tolerance. Therefore, the present study validated that catalytic ozonation was a promising technology for saving water and wastewater elimination in textile dyeing. It provides a feasibility assessment of catalytic ozonation for recycling waste effluents to reduce water dependence in textile production. Furthermore, we show a new perspective in on-site recycling waste effluents by catalytic ozonation and enrich the knowledge on feasible approaches for water management in textile production.
High-Performance Sample Substrate of Gold Nanoparticle Multilayers for Surface-Assisted Laser Desorption/Ionization Mass Spectrometry
Authors: Liu Yen-Chen , Chang Yi-Hsuan , Lin Yun-Ho , Liou Chien-Chung , Kuo Tsung-Rong
Published: July 2019

The development of a sample substrate with superior performance for desorption and ionization of analyte is the key issue to ameliorate the quality of mass spectra for measurements of small molecules in surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS). Herein, the homogeneous sample substrate of gold nanoparticle multilayers (AuNPs-ML) with hexagonal lattice was successfully prepared by self-assembly technique. With strong surface plasmon resonance absorption and superior photothermal effect, the sample substrate of AuNPs-ML exhibited high signal sensitivity and low background noise for the detection of model analyte of glucose without additional matrixes in SALDI-MS. Furthermore, compared to merchant matrixes of α-cyano-4-hydroxycinnamic acid (CHCA) and 2,5-dihydroxybenzoic acid (DHB), the sample substrate of AuNPs-ML was demonstrated to ameliorate the quality of mass spectra, including signal strength, background interference and signal/noise (S/N) ratio. The sucrose and tryptophan were also measured to show the extensive applications of AuNPs-ML sample substrate for the detections of small molecules in SALDI-MS. Most importantly, the remarkable reproducibility of glucose mass spectra with relative signal of 7.3% was obtained by the use of AuNPs-ML sample substrate for SALDI-MS. The homogeneous sample substrate of AuNPs-ML greatly improved the quality of mass spectra because of its strong absorption of laser energy, low specific heat, high heat conductivity and extraordinary homogeneity. We believe that AuNPs-ML could be a practical sample substrate for small molecule detection in SALDI-MS.
Synthesis and Properties of Ferrite-Based Nanoparticles
Authors: Kadyrzhanov Kayrat K. , Egizbek Kamila , Kozlovskiy Artem L. , Zdorovets Maxim V.
Published: July 2019

The work is dedicated to the study of the structural and optical characteristics, as well as the phase transformations, of ferrite nanoparticles of CeO2-Fe2O3. To characterize the results obtained, the methods of scanning and transmission microscopy, X-ray diffraction (XRD) spectroscopy, and Mössbauer spectroscopy were applied. It was found that the initial nanoparticles are polycrystalline structures based on cerium oxide with the presence of X-ray amorphous inclusions in the structure, which are characteristic of iron oxide. The study determined the dynamics of phase and structural transformations, as well as the appearance of a magnetic texture depending on the annealing temperature. According to the Mossbauer spectroscopy data, it has been established that a rise in the annealing temperature gives rise to an ordering of the magnetic properties and a decrease in the concentration of cationic and vacancy defects in the structure. During the life test of synthesized nanoparticles as cathode materials for lithium-ion batteries, the dependences of the cathode lifetime on the phase composition of nanoparticles were established. It is established that the appearance of a magnetic component in the structure result in a growth in the resource lifetime and the number of operating cycles. The results show the prospects of using these nanoparticles as the basis for lithium-ion batteries, and the simplicity of synthesis and the ability to control phase transformations opens up the possibility of scalable production of these nanoparticles for cathode materials.
Electrospun Bimetallic NiCr Nanoparticles@Carbon Nanofibers as an Efficient Catalyst for Hydrogen Generation from Ammonia Borane
Authors: M. Brooks Robert , Maafa Ibrahim M. , M. Al-Enizi Abdullah , M. El-Halwany M. , Ubaidullah Mohd , Yousef Ayman
Published: July 2019

In this study, we report on the fabrication and utilization of NiCr alloy nanoparticles (NPs)-decorated carbon nanofibers (CNFs) as efficient and competent non-precious catalysts for the hydrolytic dehydrogenation of ammonia borane (AB) at 25 ± 2 °C. The introduced NFs have been fabricated in one step using a high-temperature thermal decomposition of the prepared electrospun nanofiber mats (nickel acetate tetrahydrate, chromium acetate dimer, and polyvinyl alcohol) in an inert atmosphere. The chemical composition of the NFs with different proportions of Ni1−xCrx (x = 0.0, 0.1, 0.15, 0.2, 0.25, 0.3) was established via standard characterization techniques. These techniques proved the formation of disorder Cr2Ni3 alloy and carbon for all the formulations. The as-synthesized composite NFs exhibited a higher catalytic performance for AB dehydrogenation than that of Cr-free Ni–CNFs. Among all the formulations, the sample composed of 15% Cr shows the best catalytic performance, as more H2 was released in less time. Furthermore, it shows good stability, as it is recyclable with little decline in the catalytic activity after six cycles. It also demonstrates the activation energy, entropy (ΔS), and enthalpy (ΔH) with 37.6 kJ/mole, 0.094 kJ/mole, and 35.03 kJ/mole, respectively. Accordingly, the introduced catalyst has a lower price with higher performance encouraging a practical sustainable H2 energy application from the chemical hydrogen storage materials.
Fully Atomistic Molecular Dynamics Computation of Physico-Mechanical Properties of PB, PS, and SBS
Authors: Kang Yang , Zhou Dunhong , Wu Qiang , Duan Fuyan , Yao Rufang , Cai Kun
Published: July 2019

The physical properties—including density, glass transition temperature (Tg), and tensile properties—of polybutadiene (PB), polystyrene (PS) and poly (styrene-butadiene-styrene: SBS) block copolymer were predicted by using atomistic molecular dynamics (MD) simulation. At 100 K, for PB and SBS under uniaxial tension with strain rate ε ˙ = 1010 s−1 and 109 s−1, their stress–strain curves had four features, i.e., elastic, yield, softening, and strain hardening. At 300 K, the tensile curves of the three polymers with strain rates between 108 s−1 and 1010 s−1 exhibited strain hardening following elastic regime. The values of Young’s moduli of the copolymers were independent of strain rate. The plastic modulus of PS was independent of strain rate, but the Young’s moduli of PB and SBS depended on strain rate under the same conditions. After extrapolating the Young’s moduli of PB and SBS at strain rates of 0.01–1 s−1 by the linearized Eyring-like model, the predicted results by MD simulations were in accordance well with experimental results, which demonstrate that MD results are feasible for design of new materials.
Low Dose Epigallocatechin Gallate Alleviates Experimental Colitis by Subduing Inflammatory Cells and Cytokines, and Improving Intestinal Permeability
Authors: Du Yong , Ding Huihua , Vanarsa Kamala , Soomro Sanam , Baig Sahar , Hicks John , Mohan Chandra
Published: July 2019

Background: In this study, we investigate the impact of epigallocatechin gallate (EGCG), the most abundant and potent catechin in green tea, on a mouse model of inflammatory bowel disease (IBD) and the underlying mechanisms of action. Methods: C57BL/6J mice were subjected to dextran sulfate sodium (DSS)-induced IBD-like disease and then randomly divided into three groups: Model group (MD), low-dose EGCG group (LE, 20 mg/kg/d), and high-dose EGCG group (HE, 50 mg/kg/d). DSS-induced clinical and macroscopic changes were monitored daily. Intestinal permeability was assessed by FITC-Dextran assay. Results: Both high- and low-dose EGCG treatment alleviated clinical manifestations including body weight loss and disease activity index (DAI) of DSS-induced colitis. The DAI score was significantly improved after two days of EGCG treatment. At the end of the study, the macroscopic severity score (MSS) of HE and LE treatment groups were 2.4 ± 1.2, and 2.2 ± 1.0, respectively, significantly lower than that of the controls (5.0 ± 2.1). EGCG treatment also prevented colon shortening, and improved intestinal permeability and histopathological changes. In addition, EGCG treatment attenuated colon inflammation by suppressing colonic levels of pro-inflammatory cytokines IL-6, MCP-1, and TNF-alpha, and inhibited CD3+ T cell and CD68+ macrophage infiltration. Conclusion: EGCG is effective in inflammatory colitis because it reduces cellular and molecular inflammation, and reduces intestinal permeability.
Food Insecurity and Nutritional Risk among Canadian Newcomer Children in Saskatchewan
Authors: Lane Ginny , Nisbet Christine , Vatanparast Hassan
Published: July 2019

Food insecurity continues to persist among vulnerable groups in Canada, including newcomer families. This mixed-methods study uses an exploratory sequential design to characterize the food security status of newcomer families with children aged 3–13 years. Parents completed food security and 24-hour dietary recall questionnaires, and parents and service providers were interviewed to explore their food insecurity experiences. Fifty percent of participant households experienced food insecurity, while 41% of children were food insecure. More recent newcomer families, and families with parents that had completed high school or some years of postsecondary training, more commonly experienced household food insecurity, compared to families with parents without high school diplomas or those with university degrees. Food-insecure children aged 4–8 years were at higher risk of consuming a lower proportion of energy from protein, lower servings of milk products, and inadequate intakes of vitamin B12 and calcium. Participants identified changes in food buying habits due to low income, using food budgets to purchase prescription drugs and to repay transportation loans, while the school food environment impacted children’s food security. Food security initiatives targeting newcomers may benefit from building on the strengths of newcomers, including traditional dietary practices and willingness to engage in capacity-building programming.
Lutathera®: The First FDA- and EMA-Approved Radiopharmaceutical for Peptide Receptor Radionuclide Therapy
Authors: Hennrich Ute , Kopka Klaus
Published: July 2019

As the first radiopharmaceutical for Peptide Receptor Radionuclide Therapy (PRRT), Lutathera® was approved by the EMA in 2017 and the FDA in 2018 for the treatment of somatostatin receptor (SSTR) positive gastroenteropancreatic neuroendocrine tumors. Using the concept of PRRT, Lutathera® combines the radionuclide 177Lu with the somatostatin analogue DOTA-TATE, thus delivering ionizing radiation specifically to tumor cells expressing somatostatin receptors. As a result, DNA single- and double-strand breaks are provoked, in case of double-strand breaks leading to cell death of the tumor and its SSTR-positive lesions.
Glutathione-Loaded Solid Lipid Microparticles as Innovative Delivery System for Oral Antioxidant Therapy
Authors: Bertoni Serena , Albertini Beatrice , Facchini Carlotta , Prata Cecilia , Passerini Nadia
Published: July 2019

The present study aimed to develop a novel formulation containing glutathione (GSH) as an oral antioxidant therapy for the treatment of oxidative stress-related intestinal diseases. To this purpose, solid lipid microparticles (SLMs) with Dynasan 114 and a mixture of Dynasan 114 and Dynasan 118 were produced by spray congealing technology. The obtained SLMs had main particle sizes ranging from 250 to 355 µm, suitable for oral administration. GSH was efficiently loaded into the SLMs at 5% or 20% w/w and the encapsulation process did not modify its chemico-physical properties, as demonstrated by FT-IR, DSC and HSM analysis. Moreover, in vitro release studies using biorelevant media showed that Dynasan 114-based SLMs could efficiently release GSH in various intestinal fluids, while 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay demonstrated the good radical scavenging activity of this formulation. Dynasan 114-based SLMs exhibited an excellent biocompatibility on intestinal HT-29 cells at concentrations up to 2000 μg/mL. SLMs containing GSH alone or together with another antioxidant agent (catalase) were effective in reducing intracellular reactive oxygen species (ROS) levels. Overall, this study indicated that spray congealed SLMs are a promising oral drug delivery system for the encapsulation of one or more biological antioxidant agents for local intestinal treatment.
Cephalosporins: A Focus on Side Chains and β-Lactam Cross-Reactivity
Authors: Chaudhry Saira B. , Veve Michael P. , Wagner Jamie L.
Published: July 2019

Cephalosporins are among the most commonly prescribed antibiotic classes due to their wide clinical utility and general tolerability, with approximately 1–3% of the population reporting a cephalosporin allergy. However, clinicians may avoid the use of cephalosporins in patients with reported penicillin allergies despite the low potential for cross-reactivity. The misdiagnosis of β-lactam allergies and misunderstanding of cross-reactivity among β-lactams, including within the cephalosporin class, often leads to use of broader spectrum antibiotics with poor safety and efficacy profiles and represents a serious obstacle for antimicrobial stewardship. Risk factors for cephalosporin allergies are broad and include female sex, advanced age, and a history of another antibiotic or penicillin allergy; however, cephalosporins are readily tolerated even among individuals with true immediate-type allergies to penicillins. Cephalosporin cross-reactivity potential is related to the structural R1 side chain, and clinicians should be cognizant of R1 side chain similarities when prescribing alternate β-lactams in allergic individuals or when new cephalosporins are brought to market. Clinicians should consider the low likelihood of true cephalosporin allergy when clinically indicated. The purpose of this review is to provide an overview of the role of cephalosporins in clinical practice, and to highlight the incidence of, risk factors for, and cross-reactivity of cephalosporins with other antibiotics.
Circadian Network Interactions with Jasmonate Signaling and Defense
Authors: Thines Bryan , Parlan Emily V. , Fulton Elena C.
Published: July 2019

Plants experience specific stresses at particular, but predictable, times of the day. The circadian clock is a molecular oscillator that increases plant survival by timing internal processes to optimally match these environmental challenges. Clock regulation of jasmonic acid (JA) action is important for effective defenses against fungal pathogens and generalist herbivores in multiple plant species. Endogenous JA levels are rhythmic and under clock control with peak JA abundance during the day, a time when plants are more likely to experience certain types of biotic stresses. The expression of many JA biosynthesis, signaling, and response genes is transcriptionally controlled by the clock and timed through direct connections with core clock proteins. For example, the promoter of Arabidopsis transcription factor MYC2, a master regulator for JA signaling, is directly bound by the clock evening complex (EC) to negatively affect JA processes, including leaf senescence, at the end of the day. Also, tobacco ZEITLUPE, a circadian photoreceptor, binds directly to JAZ proteins and stimulates their degradation with resulting effects on JA root-based defenses. Collectively, a model where JA processes are embedded within the circadian network at multiple levels is emerging, and these connections to the circadian network suggest multiple avenues for future research.
Ultrasound-Assisted Encapsulation of Sacha Inchi (Plukenetia volubilis Linneo.) Oil in Alginate-Chitosan Nanoparticles
Authors: Elgegren Mariela , Kim Suyeon , Cordova Diego , Silva Carla , Noro Jennifer , Cavaco-Paulo Artur , Nakamatsu Javier
Published: July 2019

Sacha inchi oil is rich in essential and non-essential fatty acids and other types of bioactive agents like tocopherols and polyphenolic compounds, which are very well-known antioxidants. In this study, the encapsulation of sacha inchi oil in alginate (AL) and chitosan (CS) nanoparticles was achieved with the assistance of high-intensity ultrasound. Nanoemulsion is the most effective delivery and high stability system for lipophilic bioactive agents. Chitosan and surfactant concentrations were varied to study their effect on particle formulations. Size, zeta-potential, polydispersity, and stability of particles were determined in time to optimize the preparation conditions. Sacha inchi oil encapsulated in AL-CS nanoparticles showed a higher loading efficiency and stability for short and long periods compared with other vegetable oils such as olive and soybean. Also, because of the types of tocopherols present in sacha inchi oil (γ- and δ-tocopherols), a much higher antioxidant activity (95% of radical reduction in 15 min) was found in comparison with nanocapsules with olive oil, which contain α-tocopherols. The particles showed high efficiency of protein loading at high concentration of bovine serum albumin (BSA) and a low rate of leaching profiles in various testing media like simulated gastric and intestinal fluids with/without enzymes, that is, pepsin 0.1% (w/v) and pancreatin 0.1% (w/v), respectively.
Application of PEG-Covered Non-Biodegradable Polyelectrolyte Microcapsules in the Crustacean Circulatory System on the Example of the Amphipod Eulimnogammarus verrucosus
Authors: Shchapova Ekaterina , Nazarova Anna , Gurkov Anton , Borvinskaya Ekaterina , Rzhechitskiy Yaroslav , Dmitriev Ivan , Meglinski Igor , Timofeyev Maxim
Published: July 2019

Layer-by-layer assembled microcapsules are promising carriers for the delivery of various pharmaceutical and sensing substances into specific organs of different animals, but their utility in vivo inside such an important group as crustaceans remains poorly explored. In the current study, we analyzed several significant aspects of the application of fluorescent microcapsules covered by polyethylene glycol (PEG) inside the crustacean circulatory system, using the example of the amphipod Eulimnogammarus verrucosus. In particular, we explored the distribution dynamics of visible microcapsules after injection into the main hemolymph vessel; analyzed the most significant features of E. verrucosus autofluorescence; monitored amphipod mortality and biochemical markers of stress response after microcapsule injection, as well as the healing of the injection wound; and finally, we studied the immune response to the microcapsules. The visibility of microcapsules decreased with time, however, the central hemolymph vessel was confirmed to be the most promising organ for detecting the spectral signal of implanted microencapsulated fluorescent probes. One million injected microcapsules (sufficient for detecting stable fluorescence during the first hours after injection) showed no toxicity for six weeks, but in vitro amphipod immune cells recognize the PEG-coated microcapsules as foreign bodies and try to isolate them by 12 h after contact.
Preparation of a Series of Photoresponsive Polymersomes Bearing Photocleavable a 2-nitrobenzyl Group at the Hydrophobic/Hydrophilic Interfaces and Their Payload Releasing Behaviors
Authors: Yamamoto Shota , Yamada Takafumi , Kubo Genki , Sakurai Kazuo , Yamaguchi Kazuo , Nakanishi Jun
Published: July 2019

In this study, the structure-function relationships of a series of polymersomes composed of well-defined amphiphilic diblock copolymers were investigated. The building blocks were synthesized by clicking hydrophobic polymers, synthesized beforehand, and commercially available poly(ethylene glycol) with photocleavable 2-nitrobenzyl compounds bearing alkyne and maleimide functionalities. All of the tested polymersomes preserved their hollow structures even after sufficient photoirradiation. Nevertheless, the release rate of an entrapped anionic fluorophore was highly dependent on the molecular weight and the type of hydrophobic polymer, as well as on the presence or absence of the charged end groups. Moreover, the polymersomes with a 2-nitrosobenzyl photolysis residue within the hydrophobic shells exhibited photo-induced payload release after complete photolysis. It was concluded that the payload release was mediated by photo-induced permeability changes of the hydrophobic shells rather than the decomposition of their overall structures.
Flax, Basalt, E-Glass FRP and Their Hybrid FRP Strengthened Wood Beams: An Experimental Study
Authors: Wang Bo , Bachtiar Erik Valentine , Yan Libo , Kasal Bohumil , Fiore Vincenzo
Published: July 2019

In this study, the structural behavior of small-scale wood beams externally strengthened with various fiber strengthened polymer (FRP) composites (i.e., flax FRP (FFRP), basalt FRP (BFRP), E-glass FRP (“E” stands for electrical resistance, GFRP) and their hybrid FRP composites (HFRP) with different fiber configurations) were investigated. FRP strengthened wood specimens were tested under bending and the effects of different fiber materials, thicknesses and the layer arrangements of the FRP on the flexural behavior of strengthened wood beams were discussed. The beams strengthened with flax FRP showed a higher flexural loading capacity in comparison to the beams with basalt FRP. Flax FRP provided a comparable enhancement in the maximum load with beams strengthened with glass FRP at the same number of FRP layers. In addition, all the hybrid FRPs (i.e., a combination of flax, basalt and E-glass FRP) in this study exhibited no significant enhancement in load carrying capacity but larger maximum deflection than the single type of FRP composite. It was also found that the failure modes of FRP strengthened beams changed from tensile failure to FRP debonding as their maximum bending load increased.
An Immunosensor Based on Au-Ag Bimetallic NPs Patterned on a Thermal Resistant Flexible Polymer Substrate for In-Vitro Protein Detection
Authors: Wang Pan , Wei Shiliang , Tong Lifen , He Xiaohong , Bai Yun , Jia Kun , Liu Xiaobo
Published: July 2019

Nanosensors based on flexible polymers have emerged as powerful tools for next generation smart devices in the recent years. Here, we report a facile protocol to fabricate an immunosensor supported by a thermally resistant flexible polymer substrate (polyarylene ether nitrile, PEN). The immunosensor is a localized surface plasmon resonance (LSPR) optical sensor for in-vitro protein detection based on anti-body coated gold-silver bimetallic nanoparticles (Au-Ag NPs) immobilized on a PEN substrate. Plasmonic spectroscopy and morphological characterization show that the Au-Ag NPs essentially exhibit a more uniform size distribution and higher quality factors than those from single-component Au NPs. Furthermore, it should be noted that the robust PEN substrate in this nanosensor acts a flexible substrate to support Au-Ag NPs and immobilize the nanoparticles via quick thermal annealing at 290 °C. Thanks to these merits, a prostate-specific antigen (PSA) concentration as low as 1 ng/mL can be specifically discriminated via the prepared PEN/Au-Au NPs, which confirms that the protocol reported in this work can be readily adapted for the construction of various flexible immunosensors for different applications.
Approach for Analysis of Land-Cover Changes and Their Impact on Flooding Regime
Authors: Shrestha Badri Bhakta
Published: July 2019

This study focused on the analysis of land-use/land-cover changes and their impact on flood runoff, flood hazards and inundation, focusing in the Pampanga River basin of the Philippines. The land-cover maps for the years 1996 and 2016 were generated using Landsat images, and the land cover changes were analyzed using TerrSet Geospatial Monitoring and Modeling System (TGMMS). Based on an empirical approach and considering variable factors, the land-cover maps for the future were predicted using Land Change Modeler (LCM). After preparation of land-cover maps for past and future years, flood characteristics were analyzed using a distributed hydrological model named the rainfall runoff inundation (RRI) model with a land-cover map for different years. The impacts of land cover changes on flood runoff, flood volume and flood inundation were analyzed for 50- and 100-year floods. The results show that flood runoff, flood inundation volume and flood extent areas may increase in the future due to land-cover change in the basin.