bluuebunny/crossref_metadata_2025 huggingface dataset:
3D Printing High-Consistency Enzymatic Nanocellulose Obtained from a Soda-Ethanol-O2 Pine Sawdust Pulp
Authors: Kangas Heli , Felissia Fernando E. , Filgueira Daniel , Ehman Nanci V. , Vallejos María E. , Imlauer Camila M. , Lahtinen Panu , Area María C. , Chinga-Carrasco Gary
Published: July 2019

Soda-ethanol pulps, prepared from a forestry residue pine sawdust, were treated according to high-consistency enzymatic fibrillation technology to manufacture nanocellulose. The obtained nanocellulose was characterized and used as ink for three-dimensional (3D) printing of various structures. It was also tested for its moisture sorption capacity and cytotoxicity, as preliminary tests for evaluating its suitability for wound dressing and similar applications. During the high-consistency enzymatic treatment it was found that only the treatment of the O2-delignified pine pulp resulted in fibrillation into nano-scale. For 3D printing trials, the material needed to be fluidized further. By 3D printing, it was possible to fabricate various structures from the high-consistency enzymatic nanocellulose. However, the water sorption capacity of the structures was lower than previously seen with porous nanocellulose structures, indicating that further optimization of the material is needed. The material was found not to be cytotoxic, thus showing potential as material, e.g., for wound dressings and for printing tissue models.
Biofunctional Textiles for Aging Skin
Authors: Morganti Pierfrancesco , Morganti Gianluca , Colao Claudia
Published: July 2019

The skin is the largest organ in the human body, acting as the first protective barrier against the external environment aggression, such as UV rays and atmospheric nanoparticulate pollutants. On the one hand, the skin employs different antioxidant agents to protect its natural oxidative balance. On the other hand, ageing phenomena are the main cause of skin barrier damages, leading to a disequilibrium in the physiological redox system. Thus, the necessity to find new innovative cosmetic means, such as biodegradable non-woven tissues able to load, carry and release active ingredients in the right skin layers. These innovative cosmetic tissues can not only protect the skin from toxic environmental agents, but may balance the natural skin barrier, also acting as anti-aging agents when their fibers are bound to the right ingredients. The proposed tissues, consisting of polysaccharide natural fibers made of chitin nanofibrils and nanochitin, seem to be an ideal candidate for the production of new and effective biofunctional textiles, also because they are able to mimic the skin’s extra cellular matrix (ECM) when electrospun. These innovative cosmeceuticals have shown the possibility of being used for food formulations as well as for topic anti-aging agents, having shown an interesting repairing effectiveness on skin and also on hair. Thus, they could be used both as active ingredient and as skin smart active carriers in substitution of normal emulsions, being also biodegradable, free of chemicals, and obtainable from waste material.
Effect of Tumor Burden on Tumor Aggressiveness and Immune Modulation in Prostate Cancer: Association with IL-6 Signaling
Authors: Wu Chun-Te , Huang Yun-Ching , Chen Wen-Cheng , Chen Miao-Fen
Published: July 2019

Local treatment is known to improve survival in men with locally advanced prostate cancer (LAPC), but the underlying mechanisms remain unclear. In the present study, we examined the role of tumor burden in tumor aggressiveness, as well as the pathway responsible for these changes. We used human and murine prostate cancer cell lines to examine the role of tumor burden in tumor aggressiveness, as well as its correlation with cancer stem cell (CSC) marker levels and IL-6 signaling. Furthermore, 167 prostate cancer biopsy specimens were analyzed in terms of correlations of IL-6 and CD44 levels with clinical patient characteristics. Data from preclinical models showed that larger tumor burden was associated with more aggressive tumor growth associated and increased CD44 expression. Using cellular experiments and orthotopic tumor models, we showed that CD44+ prostate cancer cells have CSC-like properties, enhanced epithelial–mesenchymal transition (EMT), and a more immunosuppressive microenvironment. There was a significant correlation between IL-6 and CD44 levels based on in vitro testing of clinical samples. Blockade of IL-6/STAT3 signaling attenuated the expression of CD44, CSC-like properties, and aggressive tumor behavior in vitro and in vivo. In conclusion, CD44 expression is significantly associated with tumor aggressiveness in prostate cancer and activation of IL-6 signaling leads to a suitable microenvironment for the induction of CD44 expression. Based on our study, reduced tumor burden was associated with attenuated IL-6 signaling and augmented tumor rejection in the microenvironment, which might mediate the benefit of clinical adoption with aggressive local therapy.
Pretreatment of Glioblastoma with Bortezomib Potentiates Natural Killer Cell Cytotoxicity through TRAIL/DR5 Mediated Apoptosis and Prolongs Animal Survival
Authors: Gras Navarro Andrea , Espedal Heidi , Joseph Justin , Trachsel-Moncho Laura , Bahador Marzieh , Tore Gjertsen Bjørn , Klæboe Kristoffersen Einar , Simonsen Anne , Miletic Hrvoje , Øyvind Enger Per , Rahman Mohummad , Chekenya Martha
Published: July 2019

Background: Natural killer (NK) cells are potential effectors in anti-cancer immunotherapy; however only a subset potently kills cancer cells. Here, we examined whether pretreatment of glioblastoma (GBM) with the proteasome inhibitor, bortezomib (BTZ), might sensitize tumour cells to NK cell lysis by inducing stress antigens recognized by NK-activating receptors. Methods: Combination immunotherapy of NK cells with BTZ was studied in vitro against GBM cells and in a GBM-bearing mouse model. Tumour cells were derived from primary GBMs and NK cells from donors or patients. Flow cytometry was used for viability/cytotoxicity evaluation as well as in vitro and ex vivo phenotyping. We performed a Seahorse assay to assess oxygen consumption rates and mitochondrial function, Luminex ELISA to determine NK cell secretion, protein chemistry and LC–MS/MS to detect BTZ in brain tissue. MRI was used to monitor therapeutic efficacy in mice orthotopically implanted with GBM spheroids. Results: NK cells released IFNγ, perforin and granzyme A cytolytic granules upon recognition of stress-ligand expressing GBM cells, disrupted mitochondrial function and killed 24–46% of cells by apoptosis. Pretreatment with BTZ further increased stress-ligands, induced TRAIL-R2 expression and enhanced GBM lysis to 33–76% through augmented IFNγ release (p < 0.05). Blocking NKG2D, TRAIL and TRAIL-R2 rescued GBM cells treated with BTZ from NK cells, p = 0.01. Adoptively transferred autologous NK-cells persisted in vivo (p < 0.05), diminished tumour proliferation and prolonged survival alone (Log Rank10.19, p = 0.0014, 95%CI 0.252–0.523) or when combined with BTZ (Log Rank5.25, p = 0.0219, 95%CI 0.295–0.408), or either compared to vehicle controls (median 98 vs. 68 days and 80 vs. 68 days, respectively). BTZ crossed the blood–brain barrier, attenuated proteasomal activity in vivo (p < 0.0001; p < 0.01 compared to vehicle control or NK cells only, respectively) and diminished tumour angiogenesis to promote survival compared to vehicle-treated controls (Log Rank6.57, p = 0.0104, 95%CI 0.284–0.424, median 83 vs. 68 days). However, NK ablation with anti-asialo-GM1 abrogated the therapeutic efficacy. Conclusions: NK cells alone or in combination with BTZ inhibit tumour growth, but the scheduling of BTZ in vivo requires further investigation to maximize its contribution to the efficacy of the combination regimen.
Effect of High-Temperature Calcined Wheat Straw Powder after Lignin Removal on Properties of Waterborne Wood Coatings
Authors: Yan Xiaoxing , Wang Lin , Qian Xingyu
Published: July 2019

The effect of adding wheat straw powder after lignin removal (WSPALR) and high-temperature calcined WSPALR on the hardness, adhesion, and resistance to impact, color difference, and mold resistance of waterborne coatings was studied. The results showed that the hardness was the highest of 6H when the concentration of WSPALR was 1.0%–2.0%. WSPALR and high-temperature calcined WSPALR had little effect on the adhesion and impact resistance of waterborne coatings, and the resistance to impact was about 10.0 kg cm. When both the concentration of WSPALR and high-temperature calcined WSPALR were 0.5%, the waterborne coating had the best adhesion of Level 1. The addition of high-temperature calcined WSPALR maintained the color difference of the original coatings. A high WSPALR concentration showed better mold resistance than a low concentration WSPALR, and the inhibition effect of high-temperature calcined WSPALR on Trichoderma was better than that of WSPALR. When the concentration of WSPALR calcined at a high temperature was 0.5%, it showed a better hardness of 4H, Level 1 adhesion, 10.0 kg cm resistance to impact, and 1.1 color difference of the waterborne coating. This work has important application value for mold resistance of wood coatings.
Stress Corrosion Cracking Resistance of Cold-Sprayed Al 6061 Deposits Using a Newly Developed Test Fixture
Authors: Sharma Mala , Schreiber Jeremy , Eden Timothy , Champagne Victor
Published: July 2019

The stress corrosion cracking (SCC) response of Al 6061 bulk deposits produced by high-pressure cold spray (HPCS) was investigated and compared to commercial wrought Al 6061-T6 material. Representative tensile coupons were stressed to 25%, 65% and 85% of their respective yield strength and exposed to ASTM B117 salt fog for 90 days. After exposure, the samples were mechanically tested to failure, and subsequently investigated for stress corrosion cracking via optical and scanning electron microscopy with energy-dispersive X-ray spectroscopy (EDS). The results were compared to the wrought Al 6061-T6 properties and correlated with the observed microstructures. Wrought samples showed the initiation of stress corrosion cracking, while the cold-sprayed deposits appeared to be unaffected or affected by general corrosion only. Optical microscopy revealed evidence of stress corrosion cracking in the form of intergranular corrosion in the wrought samples, while no significant corrosion was observed in the cold-sprayed deposits. Fractography revealed wrought samples failed due to multiple mechanisms, with predominant cleavage and intergranular failure, but cold-sprayed samples only failed by ductile dimple rupture. The difference in SCC response between the differently processed materials is attributed to the documented benefits of the cold spray process, which includes maintaining fine grain structure of the feedstock powder and high density after consolidation, low oxidation, and work hardening effect.
Phase Selectivity in Cr and N Co-Doped TiO2 Films by Modulated Sputter Growth and Post-Deposition Flash-Lamp-Annealing
Authors: Gago Raúl , Prucnal Slawomir , Hübner René , Munnik Frans , Esteban-Mendoza David , Jiménez Ignacio , Palomares Javier
Published: July 2019

In this paper, we report on the phase selectivity in Cr and N co-doped TiO2 (TiO2:Cr,N) sputtered films by means of interface engineering. In particular, monolithic TiO2:Cr,N films produced by continuous growth conditions result in the formation of a mixed-phase oxide with dominant rutile character. On the contrary, modulated growth by starting with a single-phase anatase TiO2:N buffer layer, can be used to imprint the anatase structure to a subsequent TiO2:Cr,N layer. The robustness of the process with respect to the growth conditions has also been investigated, especially regarding the maximum Cr content (<5 at.%) for single-phase anatase formation. Furthermore, post-deposition flash-lamp-annealing (FLA) in modulated coatings was used to improve the as-grown anatase TiO2:Cr,N phase, as well as to induce dopant activation (N substitutional sites) and diffusion. In this way, Cr can be distributed through the whole film thickness from an initial modulated architecture while preserving the structural phase. Hence, the combination of interface engineering and millisecond-range-FLA opens new opportunities for tailoring the structure of TiO2-based functional materials.
Crystal Structure, Stability and Desolvation of the Solvates of Sorafenib Tosylate
Authors: Yang Peng , Qin Chunlei , Du Shichao , Jia Lina , Qin Yujia , Gong Junbo , Wu Songgu
Published: July 2019

In this study, three solvates of sorafenib tosylate were obtained from methanol, ethanol and n-methyl-2-pyrrolidone (NMP) after solvate screening and the effect of solvent on the formation of solvate was analyzed. The solvents with high value of polarity/dipolarity and appropriate hydrogen bond donor/acceptor propensity are more likely to form corresponding solvates. The crystal structures of the solvates were elucidated for the first time by using single crystal X-ray diffraction data. The analysis results indicate that methanol solvate and ethanol solvate are isostructural and hydrogen bonds could be formed between solvent molecules and sorafenib tosylate molecules. Hirshfeld surface analysis was used to research the interactions in the solvates, and the results reveal that the H···H, C···H/H···C and O···H/ H···O contacts play the vital role in molecular packing. In addition, three solvates were characterized by polarized light microscope, powder X-ray diffraction, thermogravimetric analysis and differential scanning calorimetry. The solvates show different thermodynamic stability in methanol +NMP and ethanol +NMP mixtures. Furthermore, the desolvation of solvates was studied by hot stage microscope and discussed.
Lack of Global Convergence and the Formation of Multiple Welfare Clubs across Countries: An Unsupervised Machine Learning Approach
Authors: Mendez Carlos
Published: July 2019

The cross-country convergence hypothesis is one of the central topics of long-run macroeconomics. This paper revisits this hypothesis in a context beyond GDP. It uses a novel welfare index that incorporates measures of consumption, leisure, life expectancy, and inequality. Based on a sample of 128 countries over the 1980–2007 period, the lack of global sigma and beta convergence is first documented. Next, the paper incorporates some recent developments from the unsupervised machine learning literature to evaluate the existence of local convergence. In particular, the application of a distribution-based clustering algorithm suggests the formation of three local convergence clubs. Under this classification, beta convergence is recovered for each club. However, only the core members of the richest club appear to be reducing their welfare differences in a way that is consistent with the strong notion of sigma convergence. Overall, these results re-emphasize the finding that beta convergence is necessary, but not sufficient for sigma convergence, even within convergence clubs and in a context beyond GDP.
The Culture of Professional Self-Realization as a Fundamental Factor of Students’ Internet Communication in the Modern Educational Environment of Higher Education
Authors: Odinokaya Maria , Krepkaia Tatyana , Sheredekina Oksana , Bernavskaya Maya
Published: July 2019

This article deals with the problem of the culture of professional self-realization of Russian students in the process of university education at the present stage. The role of information and communications technologies is revealed, in particular the interactive technology of self-regulation developed by the authors, as a necessary pedagogical condition for the successful professional self-realization of students. The paper describes the interactive technology of self-regulation formation used in teaching a foreign language in order to improve the educational process. The paper provides an analysis of the current state of the classroom educational environment in teaching a foreign language in order to determine the possibilities of improving the educational process. The main goal of the interactive technology of self-regulation formation is to optimize and intensify the activities of students in the classroom and extracurricular activities. The interactive technology of self-regulation formation in a nonlinguistic university was applied in the proposed work. Special attention was paid to the problem of structuring and the algorithmization of independent work. Ways for increasing interactivity are revealed, and an algorithm for teaching and speech actions in interactive mode was developed. It was established that the introduction of structured algorithmization using the interactive technology of self-regulation formation could be effectively used for teaching poorly prepared students. It has been established that the culture of professional self-actualization for modern students is directly dependent on the quality of online interaction with a university teacher. It was revealed that it is the student’s awareness of the objectives of learning interaction and ways for its implementation that allow him to competently perform his academic work, which in turn contributes to the actualization of personal professional qualities that are required by a university graduate for successful implementation in the future.
Maximum Transmit Power for UE in an LTE Small Cell Uplink
Authors: Haider Amir , Hwang Seung-Hoon
Published: July 2019

To furnish the network with small cells, it is vital to consider parameters like cell size, interference in the network, and deployment strategies to maximize the network’s performance gains expected from small cells. With a small cell network, it is critical to analyze the impact of the uplink power control parameters on the network’s performance. In particular, the maximum transmit power (Pmax) for user equipment (UE) needs to be revisited for small cells, since it is a major contributor towards interference. In this work, the network performance was evaluated for different Pmax values for the small cell uplink. Various deployment scenarios for furnishing the existing macro layer in LTE networks with small cells were considered. The Pmax limit for a small cell uplink was evaluated for both homogenous small cell and heterogeneous networks (HetNet). The numerical results showed that it would be appropriate to adopt Pmax = 18 dBm in uniformly distributed small cells rather than Pmax = 23 dBm, as in macro environments. The choice of Pmax = 18 dBm was further validated for three HetNet deployment scenarios. A decrease of 0.52 dBm and an increase of 0.03 dBm and 3.29 dBm in the proposed Pmax = 18 dBm were observed for the three HetNet deployments, respectively. Furthermore, we propose that the fractional power control mode can be employed instead of the full compensation mode in small cell uplinks.
Single-Switch LED Post-Regulator Based on a Modified Class-E Resonant Converter with Voltage Clamp
Authors: Ribas Javier , Quintana Pablo J. , Cardesin Jesus , Calleja Antonio J. , Lopez-Corominas Emilio
Published: July 2019

The strict restrictions imposed both by mandatory regulations and by the recommendations contained in current standards have led to the fact that most commercially available LED ballasts nowadays use two-stage topologies. The first stage is intended to comply with the harmonics standards and the second stage is used to control the LED current and reduce the low frequency ripple. In this work, a new DC–DC resonant converter topology is presented. This topology is derived from a modified Class-E resonant inverter by adding a clamping diode. This diode achieves a double goal: it limits the maximum switch voltage and works as a power recirculating path. This way, the proposed topology behaves as a loss-less impedance placed in series with the LED thus allowing to control the output power. This converter maintains the extremely small switching losses inherent to the Class-E inverter while reducing the voltage stress across the switch. This work presents a simplified design methodology based on the fundamental approach. This methodology was used to design and build a DC–DC post-regulator for a 40 W LED lamp. The results obtained with the laboratory prototype show that this circuit can be used to stabilize and dim the LED current while maintaining very small losses. The measured efficiency was 95.7% at nominal power and above 90% when dimmed down to 25%.
Wind Farm Modeling with Interpretable Physics-Informed Machine Learning
Authors: Howland Michael F. , Dabiri John O.
Published: July 2019

Turbulent wakes trailing utility-scale wind turbines reduce the power production and efficiency of downstream turbines. Thorough understanding and modeling of these wakes is required to optimally design wind farms as well as control and predict their power production. While low-order, physics-based wake models are useful for qualitative physical understanding, they generally are unable to accurately predict the power production of utility-scale wind farms due to a large number of simplifying assumptions and neglected physics. In this study, we propose a suite of physics-informed statistical models to accurately predict the power production of arbitrary wind farm layouts. These models are trained and tested using five years of historical one-minute averaged operational data from the Summerview wind farm in Alberta, Canada. The trained models reduce the prediction error compared both to a physics-based wake model and a standard two-layer neural network. The trained parameters of the statistical models are visualized and interpreted in the context of the flow physics of turbulent wind turbine wakes.
Near Field Wireless Powering of Deep Medical Implants
Authors: Campi Tommaso , Cruciani Silvano , De Santis Valerio , Maradei Francesca , Feliziani Mauro
Published: July 2019

This study deals with the inductive-based wireless power transfer (WPT) technology applied to power a deep implant with no fixed position. The usage of a large primary coil is here proposed in order to obtain a nearly uniform magnetic field inside the human body at intermediate frequencies (IFs). A simple configuration of the primary coil, derived by the Helmholtz theory, is proposed. Then, a detailed analysis is carried out to assess the compliance with electromagnetic field (EMF) safety standards. General guidelines on the design of primary and secondary coils are provided for powering or charging a deep implant of cylindrical shape with or without metal housing. Finally, three different WPT coil demonstrators have been fabricated and tested. The obtained results have demonstrated the validity of the proposed technology.
Resilience Informed Integrity Management of Wind Turbine Parks
Authors: Qin Jianjun , Faber Michael Havbro
Published: July 2019

A novel framework for resilience modeling of wind turbine parks is proposed in support of optimization of decisions on asset integrity management. The concept of resilience originating from natural and social sciences is adapted here to facilitate the joint optimization of decision alternatives related to design, with decision alternatives addressing organizational performance. The generic probabilistic systems representation framework by the Joint Committee on Structural Safety (JCSS) (2008) is utilized to establish a scenario-based modeling of how different types of disturbances may lead to damages and failures of systems and sub-systems of wind turbine parks, together with associated direct and indirect consequences. Special emphasis is directed on the consistent probabilistic representation of the uncertainties and the stochastic and causal dependencies within the wind turbine park system. The framework facilitates the identification of optimal asset integrity management decision alternatives that fulfill given requirements to resilience. The potentials associated with the use of the framework are highlighted by an example considering a wind turbine park with ten identical wind turbines, with each modelled as a system of mechanical, electrical, and structural sub-systems. The resilience performance characteristics of the wind turbine park, such as the expected value of generated service life benefits, the expected value of production down time, and the probability of resilience failure are modelled and quantified such as to support the ranking of decision alternatives relating to the design of the wind turbine sub-systems, the level of organizational preparedness, the percentage of the generated service life benefits to be kept to ensure sufficient economic capacity to deal with future disturbances, and the stock-keeping of essential spare parts.
Detection of Inter-Turn Faults in Multi-Phase Ferrite-PM Assisted Synchronous Reluctance Machines
Authors: Candelo-Zuluaga Carlos , Riba Jordi-Roger , López-Torres Carlos , Garcia Antoni
Published: July 2019

Inter-turn winding faults in five-phase ferrite-permanent magnet-assisted synchronous reluctance motors (fPMa-SynRMs) can lead to catastrophic consequences if not detected in a timely manner, since they can quickly progress into more severe short-circuit faults, such as coil-to-coil, phase-to-ground or phase-to-phase faults. This paper analyzes the feasibility of detecting such harmful faults in their early stage, with only one short-circuited turn, since there is a lack of works related to this topic in multi-phase fPMa-SynRMs. Two methods are tested for this purpose, the analysis of the spectral content of the zero-sequence voltage component (ZSVC) and the analysis of the stator current spectra, also known as motor current signature analysis (MCSA), which is a well-known fault diagnosis method. This paper compares the performance and sensitivity of both methods under different operating conditions. It is proven that inter-turn faults can be detected in the early stage, with the ZSVC providing more sensitivity than the MCSA method. It is also proven that the working conditions have little effect on the sensitivity of both methods. To conclude, this paper proposes two inter-turn fault indicators and the threshold values to detect such faults in the early stage, which are calculated from the spectral information of the ZSVC and the line currents.
Propeller Synchrophasing Control with a Cylindrical Scaled Fuselage Based on an Improved Data Selection Algorithm
Authors: Sheng Long , Huang Xianghua , Cao Yunfei
Published: July 2019

Propeller synchrophasing control is an active noise control method which can effectively reduce the noise in the cabin of a turboprop aircraft. The propeller signature model identified by the measured acoustic noise data is easily affected by flight speed, altitude, and the existence of the fuselage. Meanwhile, the noise excited by the propellers is nonstationary signal, which often fluctuates greatly, thus affecting the accuracy of the identification of the model. In this paper, a synchrophasing control experimental platform with a cylindrical scaled fuselage on ground is firstly established to validate the actual noise reduction in the cabin. Then, a minimum fluctuation data selection method based on wavelet filtering and three-parameter sinusoidal fitting is proposed to improve the identification accuracy of the propeller signature model. This method extracts the high-precision propeller blade passing frequency signal from the noise signal by using a wavelet filtering algorithm and selects the minimum fluctuation data segment by using a three-parameter sinusoidal fitting algorithm. The experimental results firstly show the significant noise attenuation achieved in the cabin using propeller synchrophasing control. Secondly, the propeller signature model improved by the minimum fluctuation data selection method has higher accuracy than that identified by the traditional method.
Protected Cropping in Warm Climates: A Review of Humidity Control and Cooling Methods
Authors: Rabbi Barkat , Chen Zhong-Hua , Sethuvenkatraman Subbu
Published: July 2019

The projected increase of the world’s population, coupled with the shrinking area of arable land required to meet future food demands, is building pressure on Earth’s finite agricultural resources. As an alternative to conventional farming methods, crops can be grown in protected environments, such as traditional greenhouses or the more modern plant factories. These are usually more productive and use resources more efficiently than conventional farming and are now receiving much attention—especially in urban and peri-urban areas. Traditionally, protected cropping has been predominantly practised in temperate climates, but interest is rapidly rising in hot, arid areas and humid, tropical regions. However, maintaining suitable climatic conditions inside protected cropping structures in warm climates—where warm is defined as equivalent to climatic conditions that require cooling—is challenging and requires different approaches from those used in temperate conditions. In this paper, we review the benefits of protected cropping in warm climates, as well as the technologies available for maintaining a controlled growing environment in these regions. In addition to providing a summary of active cooling methods, this study summarises photovoltaic (PV)-based shading methods used for passive cooling of greenhouses. Additionally, we also summarise the current humidity-control techniques used in the protected cropping industry and identify future research opportunities in this area. The review includes a list of optimum growing conditions for a range of crop species suited to protected cropping in warm climates.
Digital Control of a Buck Converter Based on Input-Output Linearization. An Interpretation Using Discrete-Time Sliding Control Theory
Authors: Vidal-Idiarte Enric , Restrepo Carlos , El Aroudi Abdelali , Calvente Javier , Giral Roberto
Published: July 2019

This paper presents the analysis and design of a PWM nonlinear digital control of a buck converter based on input-output linearization. The control employs a discrete-time bilinear model of the power converter for continuous conduction mode operation (CCM) to create an internal current control loop wherein the inductor current error with respect to its reference decreases to zero in geometric progression. This internal loop is as a constant frequency discrete-time sliding mode control loop with a parameter that allows adjusting how fast the error is driven to zero. Subsequently, an outer voltage loop designed by linear techniques provides the reference of the inner current loop to regulate the converter output voltage. The two-loop control offers a fast transient response and a high regulation degree of the output voltage in front of reference changes and disturbances in the input voltage and output load. The experimental results are in good agreement with both theoretical predictions and PSIM simulations.
Series-Parallel Reconfiguration Technique with Voltage Equalization Capability for Electric Double-Layer Capacitor Modules
Authors: Uno Masatoshi , Iwasaki Koyo , Hasegawa Koki
Published: July 2019

Voltage variations of electric double-layer capacitors (EDLCs) are rather wider than those of traditional rechargeable batteries, and an energy utilization ratio of EDLCs is dependent on cells’ voltage variation ranges. To satisfactorily utilize EDLCs’ energies, voltages of EDLC modules should be within a certain range, while cells need to be charged and discharged over the wide voltage range. To this end, various kinds of series-parallel reconfiguration techniques based on balance- and unbalance-shift circuits have been proposed, but conventional techniques can only be applied to modules consisting of even number cells, impairing the design flexibility and scalability. With the unbalance-shift circuits, cell voltages are unavoidably mismatched due to unequal currents, resulting in reduced energy utilization ratios. This article proposes a novel series-parallel reconfiguration technique with voltage equalization capability for EDLC modules. The proposed technique can be applied to any number of cells, improving design flexibility and scalability. Furthermore, since the proposed circuit behaves as a switched capacitor converter, in which all cells are virtually connected in parallel, cells are equally charged and discharged without causing voltage imbalance, realizing the improved energy utilization ratio. A prototype for an EDLC module comprising four cells, each with a rated charging voltage of 2.5 V, was built and experimentally tested. The module voltage varied in the range of 3.2–5.0 V, while all cells were uniformly discharged down to as low as 0.8 V, achieving the energy utilization ratio of 90%.
Production and Regression Models for Biomass and Carbon Captured in Gmelina arborea Roxb. Trees in Short Rotation Coppice Plantations in Costa Rica
Authors: Tenorio Carolina , Moya Róger , Ortiz-Malavassi Edgar , Arias Dagoberto
Published: July 2019

Mortality, diameter at 30 cm over ground level, height, biomass production, and carbon capture (CC) for different tree components (trunk, bark, branches, and leaves) in two locations in Costa Rica, during their first three years and with three plantation spacings (1.0 × 0.5 m, 1.0 × 1.0 m, and 1.0 × 2.0 m) were obtained for Gmelina arborea Roxb. trees growing in short rotation coppice systems (SRC). In addition, regression models were developed to predict biomass production and CC using location, age, spacing, and their interactions. Biomass production was measured by weight of trees without considering dendrometric variables. Results showed that mortality was lower than 15% for one location, with probable high fertility, and almost 85% for the other location. Diameter and height of trees increased with plantation age in both locations. The highest biomass production and CC were observed in the spacings of 1.0 × 0.5 m2 and 1.0 × 1.0 m2, with 20 Mg/ha/year and 8 Mg/ha/year, respectively. The models to predict biomass production in trunk with bark, branches, leaves, total biomass without leaves, and CC in trunk, branch, and total biomass were developed using this equation: Y = β1 + β2 (location × age) + β3 (age) + β4 (spacing). The R2 values varied from 0.66 to 0.84, with error from 0.88 to 10.75 and indicators of goodness of fit from 60 to 83%.
A Game Theoretic Interference Management Scheme in Full Duplex Cellular Systems under Infeasible QoS Requirements
Authors: Al-Zahrani Ali Y.
Published: July 2019

Several emerging mobile applications and services (e.g., autonomous cars) require higher wireless throughput than ever before. This demand stresses the need for investigating novel methods that have the potential to dramatically increase the spectral efficiency (SE) of wireless systems. An evolving approach is the Single-channel full duplex (SCFD) communication where each node may simultaneously receive and transmit over the same frequency channel, and, hence, this could potentially double the current SE figures. In an earlier research work, we derived a model of the signal to interference plus noise ratio (SINR) in an SCFD-based cellular system with imperfect self interference cancellation, and investigated interference management under feasible QoS requirements. In this paper, game theoretic results are exploited to investigate the intercell interference management in SCFD-based cellular networks under infeasible QoS requirements. The investigation starts with a game formulation that captures two different cases. Then, the existence and uniqueness of the Nash equilibrium point are established. After that, a computationally efficient distributed algorithm, which realizes best effort and fair wireless services, is designed. The merit of this scheme is that, when the QoS requirements are feasible, they will be achieved with minimum energy consumption. Results of extensive simulation experiments are presented to show the effectiveness of the proposed schemes.
Determination of the Sensory Characteristics of Traditional and Novel Fortified Blended Foods Used in Supplementary Feeding Programs
Authors: Chanadang Sirichat , Chambers IV Edgar
Published: July 2019

Despite the wide use of traditional non-extruded fortified blended foods (FBFs), such as corn soy blend plus (CSB+), in supplementary feeding programs, there is limited evidence of its effectiveness on improving nutritional outcomes and little information on actual sensory properties. Fifteen novel extruded FBFs were developed with variations in processing and ingredients in order to improve the quality of food aid products based on the Food Aid Quality Review (FAQR) recommendations. Descriptive sensory analysis was performed to determine the effects of the processing parameters and ingredients on the sensory properties of traditional and novel FBFs. The extrusion process affected the aroma and flavor of the tested products. Novel FBFs from the extrusion process had more pronounced toasted characteristics, probably because of the high temperature used during extrusion. The ingredient composition of the FBFs also had a significant impact on the sensory properties of the products. The addition of sugar to novel FBFs leads to a significant increase in sweetness, which could improve acceptance. The level of lipids in binary blends appeared to be mainly responsible for the bitterness of the product. In addition, legumes, which were a primary ingredient, contributed to the beany characteristics of the products. The higher amounts of legume used in the formulations led to beany characteristics that could be perceived from the products and could be a negative trait depending on consumers’ prior use of legume-based products.
Skeleton Line Extraction Method in Areas with Dense Junctions Considering Stroke Features
Authors: Li Chengming , Yin Yong , Wu Pengda , Wu Wei
Published: July 2019

Extraction of the skeleton line of complex polygons is difficult, and a hot topic in map generalization study. Due to the irregularity and complexity of junctions, it is difficult for traditional methods to maintain main structure and extension characteristics when dealing with dense junction areas, so a skeleton line extraction method considering stroke features has been proposed in this paper. Firstly, we put forward a long-edge adaptive node densification algorithm, which is used to construct boundary-constrained Delaunay triangulation to uniformly divide the polygon and extract the initial skeleton line. Secondly, we defined the triangles with three adjacent triangles (Type III) as the basic unit of junctions, then obtained the segmented areas with dense junctions on the basis of local width characteristics and correlation relationships of each Type III triangle. Finally, we concatenated the segments into strokes and corrected the initial skeleton lines based on the extension direction features of each stroke. The actual water network data of Jiangsu Province in China were used to verify the method. Experimental results show that the proposed method can better identify the areas with dense junctions and that the extracted skeleton line is naturally smooth and well-connected, which accurately reflects the main structure and extension characteristics of these areas.
Platelets Are Critical Key Players in Sepsis
Authors: Vardon-Bounes Fanny , Ruiz Stéphanie , Gratacap Marie-Pierre , Garcia Cédric , Payrastre Bernard , Minville Vincent
Published: July 2019

Host defense against infection is based on two crucial mechanisms: the inflammatory response and the activation of coagulation. Platelets are involved in both hemostasis and immune response. These mechanisms work together in a complex and synchronous manner making the contribution of platelets of major importance in sepsis. This is a summary of the pathophysiology of sepsis-induced thrombocytopenia, microvascular consequences, platelet-endothelial cells and platelet–pathogens interactions. The critical role of platelets during sepsis and the therapeutic implications are also reviewed.
Free-Energy Calculations for Bioisosteric Modifications of A3 Adenosine Receptor Antagonists
Authors: Jandova Zuzana , Jespers Willem , Sotelo Eddy , Gutiérrez-de-Terán Hugo , Oostenbrink Chris
Published: July 2019

Adenosine receptors are a family of G protein-coupled receptors with increased attention as drug targets on different indications. We investigate the thermodynamics of ligand binding to the A3 adenosine receptor subtype, focusing on a recently reported series of diarylacetamidopyridine inhibitors via molecular dynamics simulations. With a combined approach of thermodynamic integration and one-step perturbation, we characterize the impact of the charge distribution in a central heteroaromatic ring on the binding affinity prediction. Standard charge distributions according to the GROMOS force field yield values in good agreement with the experimental data and previous free energy calculations. Subsequently, we examine the thermodynamics of inhibitor binding in terms of the energetic and entropic contributions. The highest entropy penalties are found for inhibitors with methoxy substituents in meta position of the aryl groups. This bulky group restricts rotation of aromatic rings attached to the pyrimidine core which leads to two distinct poses of the ligand. Our predictions support the previously proposed binding pose for the o-methoxy ligand, yielding in this case a very good correlation with the experimentally measured affinities with deviations below 4 kJ/mol.
Effect of Resveratrol on In Vitro and In Vivo Models of Diabetic Retinophathy: A Systematic Review
Authors: Toro Mario D. , Nowomiejska Katarzyna , Avitabile Teresio , Rejdak Robert , Tripodi Sarah , Porta Alessandro , Reibaldi Michele , Figus Michele , Posarelli Chiara , Fiedorowicz Michal
Published: July 2019

A large number of preclinical studies suggest the involvement of resveratrol in the prevention and treatment of eye diseases induced by oxidative stress and inflammation. We tested the hypothesis that resveratrol influences many pathways of in vitro and in vivo models of diabetic retinopathy through a systematic literature review of original articles. The review was conducted in accordance with the PRISMA guidelines. A literature search of all original articles published until April 2019 was performed. The terms “resveratrol” in combination with “retina”, “retinal pathology”, “diabetic retinopathy” and “eye” were searched. Possible biases were identified with the adopted SYRCLE’s tool. Eighteen articles met inclusion/exclusion criteria for full-text review. Eleven of them included in vitro experiments, 11 studies reported in vivo data and 3 studies described both in vitro and in vivo experiments. Most of the in vivo studies did not include data that would allow exclusion of bias risks, according to SYRCLE’s risk of bias tool. Both in vitro and in vivo data suggest anti-apoptotic, anti-inflammatory and anti-oxidative actions of resveratrol in models of diabetic retinopathy. However, results on its anti-angiogenic effects are contradictory and need more rigorous studies.
Unravelling the MicroRNA-Mediated Gene Regulation in Developing Pongamia Seeds by High-Throughput Small RNA Profiling
Authors: Jin Ye , Liu Lin , Hao Xuehong , Harry David E. , Zheng Yizhi , Huang Tengbo , Huang Jianzi
Published: July 2019

Pongamia (Millettia pinnata syn. Pongamia pinnata) is a multipurpose biofuel tree which can withstand a variety of abiotic stresses. Commercial applications of Pongamia trees may substantially benefit from improvements in their oil-seed productivity, which is governed by complex regulatory mechanisms underlying seed development. MicroRNAs (miRNAs) are important molecular regulators of plant development, while relatively little is known about their roles in seed development, especially for woody plants. In this study, we identified 236 conserved miRNAs within 49 families and 143 novel miRNAs via deep sequencing of Pongamia seeds sampled at three developmental phases. For these miRNAs, 1327 target genes were computationally predicted. Furthermore, 115 differentially expressed miRNAs (DEmiRs) between successive developmental phases were sorted out. The DEmiR-targeted genes were preferentially enriched in the functional categories associated with DNA damage repair and photosynthesis. The combined analyses of expression profiles for DEmiRs and functional annotations for their target genes revealed the involvements of both conserved and novel miRNA-target modules in Pongamia seed development. Quantitative Real-Time PCR validated the expression changes of 15 DEmiRs as well as the opposite expression changes of six targets. These results provide valuable miRNA candidates for further functional characterization and breeding practice in Pongamia and other oilseed plants.
Comparative Study of DDS with Different Types of Phase Accumulators
Authors: Polikarovskykh Oleksiy , Karpova Lesia , Hula Ihor , Melnychuk Vasyl
Published: July 2019

The paper deals with the problems of delayed transfer signals in the direct digital synthesizer (DDS) phase accumulator adders. Transfer delay is one of the factors that affect the maximum output frequency of the DDS synthesizer. The main types of adders used in DDS synthesizers are described. Separately, attention was paid to the adder with a consistent transfer of the transfer signal, adders with a transmission carry signal with a fixed block length, adders with a signal transmission delay with a variable block length, and a mathematical analysis of the origin and duration of the delay of the transfer signal in them. It was found that the use of a transfer adder with a variable length of a block in the core of a direct digital synthesizer would increase the maximum output frequency by 2.4 times compared to the adder with a parallel transfer, and by 1.43 times as compared with the adder with a fixed length the block.
Changes in Spinal and Corticospinal Excitability in Patients with Chronic Ankle Instability: A Systematic Review with Meta-Analysis
Authors: Kim Kyung-Min , Kim Joo-Sung , Cruz-Díaz David , Ryu Seungho , Kang Minsoo , Taube Wolfgang
Published: July 2019

The objective of this systematic review with meta-analysis was to determine alterations in spinal and corticospinal excitability of ankle muscles in patients with chronic ankle instability (CAI) compared to uninjured controls. Independent researchers performed comprehensive literature searches of electronic databases and included studies that compared groups with and without CAI and investigated neural excitability with Hoffmann reflex (H-reflex) and/or transcranial magnetic stimulation (TMS). A fixed-effect meta-analysis was conducted to determine group differences for (1) soleus and fibularis maximal H-reflex (Hmax)/maximal M-wave (Mmax)-ratios, and (2) soleus and fibularis longus cortical motor thresholds (CMTs). Seventeen studies were included in the current meta-analysis. They showed that the Hmax/Mmax-ratios of the soleus and the fibularis longus in the CAI group were significantly lower than those in the uninjured control group (soleus: d = −0.41, p < 0.001; fibularis longus: d = −0.27, p = 0.04). There was no evidence for changes in the CMT. This systematic review is the first to demonstrate evidence that patients with CAI present decreased spinal reflex excitability in the soleus and fibularis longus. However, there is no evidence of changes in supraspinal excitability when considering only the CMT. The latter result needs to be interpreted with caution as all except one study demonstrate some changes at the supraspinal level with CAI.