bluuebunny/crossref_metadata_2025 huggingface dataset:
Estudio experimental de acopladores bicónicos de fibra óptica aplicados al desarrollo de multiplexores por división de longitud de onda
Authors: Hernández-Arriaga M.V. , Bello-Jiménez M. , Ibarra-Escamilla B. , Loredo-Trejo A.
Published: May 2018

Se reporta un estudio experimental de la t\'ecnica de fabricaci\'on de acopladores bic\'onicos de fibra \'optica y su aplicaci\'on al desarrollo de multiplexores por divisi\'on de longitud de onda (WDM, wavelengthdivisionmultiplexer). Los par\'ametros de fabricaci\'on requeridos para el WDM son obtenidos del an\'alisis te\'orico de la respuesta espectral de un acoplador d\'ebilmente fusionado. Como caso particular, se reporta el desarrollo de un WDM 1550/1850 nm, el cual es un dispositivo fundamental en el desarrollo de l\'aseres de fibra \'optica dopada con Tulio. Las dimensiones finales del dispositivo son una longitud total de 36.3 mm, una cintura uniforme de 6.5 mm de largo con una secci\'on transversal de 23 μm. El dispositivo exhibe bajas p\'erdidas por inserci\'on de 0.17 dB, un espaciamiento entre canales de 303.52 nm y ancho de banda de  ± 50 nm. Este trabajo establece una gu\'ia de fabricaci\'on para el desarrollo de acopladores y dispositivos WDM de fibra \'optica.
Refractive index evaluation of porous silicon using Bragg reflectors
Authors: Estrada-Wiese D. , Del Río J.A.
Published: May 2018

There are two main physical properties needed to fabricate 1D photonic structures and form perfect photonic bandgaps: the quality of thethickness periodicity and the refractive index of their components. Porous silicon (PS) is a nano-structured material widely used to prepare 1Dphotonic crystals due to the ease of tuning its porosity and its refractive index by changing the fabrication conditions. Since the morphologyof PS changes with porosity, the determination of PS’s refractive index is no easy task. To find the optical properties of PS we can usedifferent effective medium approximations (EMA). In this work we propose a method to evaluate the performance of the refractive index ofPS layers to build photonic Bragg reflectors. Through a quality factor we measure the agreement between theory and experiment and thereinpropose a simple procedure to determine the usability of the refractive indices. We test the obtained refractive indices in more complicatedstructures, such as a broadband Vis-NIR mirror, and by means of a Merit function we find a good agreement between theory and experiment.With this study we have proposed quantitative parameters to evaluate the refractive index for PS Bragg reflectors. This procedure could havean impact on the design and fabrication of 1D photonic structures for different applications.
Effect of pressure on structural, electronic and optical properties of SrF2: a first principles study
Authors: Hoat D.M. , Rivas Silva J.F. , Méndez Blas A. , Ríos Rámirez J.J.
Published: May 2018

We report results of the first principles calculations of structural, electronic and optical properties of SrF2 under pressure, performed using full-potential linearized augmented plane wave (FP-LAPW) method based on density functional theory as implemented on WIEN2k code. The exchange-correlation energy functional has been treated with generalised gradient approximation (GGA) for structural optimization,while the Tran-Blaha modifed Becke-Johnson potential (TB-mBJ) has been employed for electronic and optical calculations. Our results show that the first transition from Fm3m to Pnam structure occurs at 5.8 GPa and the second transformation from Pnam to P63/mmc structure takes place at 24.8 GPa. Our electronic calculation indicates an indirect gap X-Γ of Fm3m structure, direct gap Γ-Γ of Pnam structure and indirect gap Γ-K of P63/mmc structure. We do not observe the metallization up to 210 GPa. The linear optical properties such as absorption coefficient, reflectivity, refraction index, conductivity and energy loss function have been derived from calculated complex dielectric function for a wide energy range of 0-50 eV and pressure up to 50 GPa, and analyzed in detail.
Historicising the Emergence of Comics Art Scholarship in Spain, 1965–1975
Authors: Lázaro-Reboll Antonio
Published: May 2018

This article traces the formation of comics art scholarship in Spain from
1965 to 1975. This decade witnessed the beginning of the study of comics
as a serious object of cultural analysis. Reading formations surrounding the
medium – in particular, historical and critical reading protocols – and a set
of key critical debates were concurrent with the establishment and the development
of mass communication studies as an incipient field of research in
Spain in the mid-1960s. The aim of this article is to provide a close examination
of the first generation of critics participating in and writing about
the scene in relation to hitherto overlooked local and transnational contexts
that shaped the constitution of the Spanish field of comics.
Paco Roca’s Graphic Novel La Casa (2015) as Architectural Elegy
Authors: Fraser Benjamin
Published: May 2018

This article explores Paco Roca’s graphic novel La Casa (2015) with attention
to the structuring role of architecture at two interrelated levels of analysis.
At the level of theme and represented content, the comic employs architecture
as a mediator of emotional connections and familial grief. At the level
of comics form and visual narrative structure, artistic choices underscore
the architectural properties of La Casa’s own construction. Repurposing
the notion of ‘iconostasis’ from Andrei Molotiu provides a way of bringing
together the reader’s self-directed perusal of the comic’s page and the characters’
self-directed navigation of their grief. The characters’ collaborative
construction of a pergola as an architectural addition to their father’s house
holds two meanings. It provides a degree of emotional closure, further contributing
to the architectural theme of the comic, and it pulls the architectural
structure of the work towards a cathartic narrative resolution.
Social Criticism through Humour in the Digital Age
Authors: Muñoz-Basols Javier , Massaguer Comes Marina
Published: May 2018

Numerous authors of comics and graphic novels have used the economic
crisis in the Iberian Peninsula as a narrative frame for social criticism.
Prominent amongst them is the Catalan cartoonist Aleix Saló, who burst
onto the comics scene with his animated YouTube video Españistán, a
book trailer for his graphic novel Españistán: Este país se va a la mierda
[Españistán: This country is going to hell] (2011). This article shows how
Saló offers a humorous and didactic portrait of the devastating effects of the
economic crisis: he does this through multimodality (using specific shapes,
colours, fonts and components of orality) and through creating ‘multimodal
extensions’, intertextual relations between published books and book trailers.
This analysis presents a case study of the multimodal techniques that
authors use to shape and develop their work in the context of the powerful
relationship between text and image in the digital age.
Status of Serum Iron and Copper in Women Taking Oral Contraceptive
Authors: Hasanat F , Chakroborty PK , Hasanat A , Sharmin SK , Mannan MB , Nargis S
Published: May 2018

The oral contraceptive pill fulfills the great human need for birth control with unrivalled effectiveness. The pill can effectively prevent pregnancy and alleviate many menstrual disorders when used correctly. Many biochemical profiles of women taking oral contraceptives are disturbed due to metabolic alterations induced by its hormone content. The study was carried out in the Department of Biochemistry, Mymensingh Medical College, Mymensingh, during the period of July 2016 to June 2017 to evaluate the status of serum iron and copper in women taking oral contraceptive pills. For this study 120 agematched women were selected and grouped as 60 oral contraceptive user women and 60 non-oral contraceptive user women. Data were analyzed with the help of SPSS version 21. Mean(±SD) level of serum iron and copper were 155.20±21.94 mg/dl and 157.6±14.75 mg/dl in oral contraceptive user women, while in normal healthy women the levels were 103±19.11 mg/dl and 126.28±17.18 mg/dl respectively. Serum iron and copper levels were significantly increased in oral contraceptive user group when compared with that of normal healthy group (p<0.001). From this study it can be concluded that there is significant association of serum iron and copper level with oral contraceptives.Bangladesh J Med Biochem 2017; 10(1): 5-9
Serum Hepatic Enzymes Level in Type 2 Diabetes Mellitus in a Tertiary Level Hospital
Authors: Fatema K , Parvin D , Islam S , Hossain MSR , Rumman MA , Afroz F , Quamrunnahar F , Sultana N
Published: May 2018

Diabetes mellitus is one of the most common non-communicable diseases globally. Magnitude of DM in developing countries including Bangladesh is rising rapidly. Several studies across the world have reported the association of higher serum hepatic enzyme levels with type 2 DM which may be an expression of excess deposition of fat in the liver. Thus, serum hepatic enzyme levels may serve as a marker of insulin resistance in the liver and may predict the prognosis and complications in type 2 DM individuals. The present crosssectional study was conducted in the Department of Biochemistry, Dhaka Medical College, Dhaka from July' 2015 to June' 2016 to find out the association of serum hepatic enzyme levels with type 2 DM individuals in a tertiary level hospital. A total number of 100 subjects were selected with the age ranging from 30 to 60 years. Among them, 50 diagnosed type 2 DM individuals were included in the Group A and 50 apparently healthy individuals were selected as Group B for comparison. The study parameters were fasting plasma glucose (FPG), HbA1c, ALT, AST, ALP and GGT. The mean(±SD) serum ALT, AST, ALP and GGT concentration (U/L) in cases were 46.28±.81, 28.17±10.08, 118.26±16.08 and 36.98±10.08 respectively and mean(±SD) serum ALT, AST, ALP and GGT concentration(U/L) in controls were 29.54±8.56, 24.54±6.89, 96.68±14.36 and 23.82±6.98 respectively. The present study showed that higher levels of serum hepatic enzymes (ALT, AST, ALP and GGT) were present in subjects with type 2 diabetes mellitus. Among these parameters, ALT, ALP and GGT showed positive correlation with FPG and HbA1c in both groups but AST showed no correlation with FPG and HbA1c.Bangladesh J Med Biochem 2017; 10(2): 58-63
The NIRS Brain AnalyzIR Toolbox
Authors: Santosa Hendrik , Zhai Xuetong , Fishburn Frank , Huppert Theodore
Published: May 2018

Functional near-infrared spectroscopy (fNIRS) is a noninvasive neuroimaging technique that uses low-levels of light (650–900 nm) to measure changes in cerebral blood volume and oxygenation. Over the last several decades, this technique has been utilized in a growing number of functional and resting-state brain studies. The lower operation cost, portability, and versatility of this method make it an alternative to methods such as functional magnetic resonance imaging for studies in pediatric and special populations and for studies without the confining limitations of a supine and motionless acquisition setup. However, the analysis of fNIRS data poses several challenges stemming from the unique physics of the technique, the unique statistical properties of data, and the growing diversity of non-traditional experimental designs being utilized in studies due to the flexibility of this technology. For these reasons, specific analysis methods for this technology must be developed. In this paper, we introduce the NIRS Brain AnalyzIR toolbox as an open-source Matlab-based analysis package for fNIRS data management, pre-processing, and first- and second-level (i.e., single subject and group-level) statistical analysis. Here, we describe the basic architectural format of this toolbox, which is based on the object-oriented programming paradigm. We also detail the algorithms for several of the major components of the toolbox including statistical analysis, probe registration, image reconstruction, and region-of-interest based statistics.
Quantification of Methane and Ammonia Emissions in a Naturally Ventilated Barn by Using Defined Criteria to Calculate Emission Rates
Authors: Schmithausen Alexander J. , Schiefler Inga , Trimborn Manfred , Gerlach Katrin , Südekum Karl-Heinz , Pries Martin , Büscher Wolfgang
Published: May 2018

Extensive experimentation on individual animals in respiration chambers has already been carried out to evaluate the potential of dietary changes and opportunities to mitigate CH4 emissions from ruminants. Although it is difficult to determine the air exchange rate of open barn spaces, measurements at the herd level should provide similarly reliable and robust results. The primary objective of this study was (1) to define a validity range (data classification criteria (DCC)) for the variables of wind velocity and wind direction during long-term measurements at barn level; and (2) to apply this validity range to a feeding trial in a naturally cross-flow ventilated dairy barn. The application of the DCC permitted quantification of CH4 and NH3 emissions during a feeding trial consisting of four periods. Differences between the control group (no supplement) and the experimental group fed a ration supplemented with condensed Acacia mearnsii tannins (CT) became apparent. Notably, CT concentrations of 1% and 3% of ration dry matter did not reduce CH4 emissions. In contrast, NH3 emissions decreased 34.5% when 3% CT was supplemented. The data confirm that quantification of trace gases in a naturally ventilated barn at the herd level is possible.
Exploring the Effect of Phage Therapy in Preventing Vibrio anguillarum Infections in Cod and Turbot Larvae
Authors: Rørbo Nanna , Rønneseth Anita , Kalatzis Panos , Rasmussen Bastian , Engell-Sørensen Kirsten , Kleppen Hans , Wergeland Heidrun , Gram Lone , Middelboe Mathias
Published: May 2018

The aquaculture industry is suffering from losses associated with bacterial infections by opportunistic pathogens. Vibrio anguillarum is one of the most important pathogens, causing vibriosis in fish and shellfish cultures leading to high mortalities and economic losses. Bacterial resistance to antibiotics and inefficient vaccination at the larval stage of fish emphasizes the need for novel approaches, and phage therapy for controlling Vibrio pathogens has gained interest in the past few years. In this study, we examined the potential of the broad-host-range phage KVP40 to control four different V. anguillarum strains in Atlantic cod (Gadus morhua L.) and turbot (Scophthalmus maximus L.) larvae. We examined larval mortality and abundance of bacteria and phages. Phage KVP40 was able to reduce and/or delay the mortality of the cod and turbot larvae challenged with V. anguillarum. However, growth of other pathogenic bacteria naturally occurring on the fish eggs prior to our experiment caused mortality of the larvae in the unchallenged control groups. Interestingly, the broad-spectrum phage KVP40 was able to reduce mortality in these groups, compared to the nonchallenge control groups not treated with phage KVP40, demonstrating that the phage could also reduce mortality imposed by the background population of pathogens. Overall, phage-mediated reduction in mortality of cod and turbot larvae in experimental challenge assays with V. anguillarum pathogens suggested that application of broad-host-range phages can reduce Vibrio-induced mortality in turbot and cod larvae, emphasizing that phage therapy is a promising alternative to traditional treatment of vibriosis in marine aquaculture.
Antioxidant Capacity of Rigenase®, a Specific Aqueous Extract of Triticum vulgare
Authors: Antonucci Immacolata , Fiorentino Gabriella , Contursi Patrizia , Minale Massimiliano , Riccio Rodolfo , Riccio Salvatore , Limauro Danila
Published: May 2018

Reactive species of oxygen (ROS), responsible for oxidative stress, accumulate in various tissues damaged by burns, decubitus ulcers, and vascular lesions. Antioxidants play an important and well-documented role in healing of chronic and acute wounds. Rigenase®, a specific extract of Triticum vulgare manufactured by Farmaceutici Damor, is employed in products used for the regeneration of tissue injuries. In this work, we show that Rigenase® exhibits a scavenging effect toward free radicals, thus pointing to its relevant antioxidant activity.
Design of Demonstration-Driven Assembling Manipulator
Authors: Wei Qianxiao , Yang Canjun , Fan Wu , Zhao Yibing
Published: May 2018

Currently, a mechanical arm or manipulator needs to be programmed by humans in advance to define its motion trajectory before practical use. However, the programming is tedious and high-cost, which renders such manipulators unable to perform various different tasks easily and quickly. This article focuses on the design of a vision-guided manipulator without explicit human programming. The proposed demonstration-driven system mainly consists of a manipulator, control box, and camera. Instead of programming of the detailed motion trajectory, one only needs to show the system how to perform a given task manually. Based on internal object recognition and motion detection algorithms, the camera can capture the information of the task to be performed and generate the motion trajectories for the manipulator to make it copy the human demonstration. The movement of the joints of the manipulator is given by a trajectory planner in the control box. Experimental results show that the system can imitate humans easily, quickly, and accurately for common tasks such as sorting and assembling objects. Teaching the manipulator how to complete the desired motion can help eliminate the complexity of programming for motion control.
Determination of Geometrical REVs Based on Volumetric Fracture Intensity and Statistical Tests
Authors: Liu Ying , Wang Qing , Chen Jianping , Song Shengyuan , Zhan Jiewei , Han Xudong
Published: May 2018

This paper presents a method to estimate a representative element volume (REV) of a fractured rock mass based on the volumetric fracture intensity P32 and statistical tests. A 150 m × 80 m × 50 m 3D fracture network model was generated based on field data collected at the Maji dam site by using the rectangular window sampling method. The volumetric fracture intensity P32 of each cube was calculated by varying the cube location in the generated 3D fracture network model and varying the cube side length from 1 to 20 m, and the distribution of the P32 values was described. The size effect and spatial effect of the fractured rock mass were studied; the P32 values from the same cube sizes and different locations were significantly different, and the fluctuation in P32 values clearly decreases as the cube side length increases. In this paper, a new method that comprehensively considers the anisotropy of rock masses, simplicity of calculation and differences between different methods was proposed to estimate the geometrical REV size. The geometrical REV size of the fractured rock mass was determined based on the volumetric fracture intensity P32 and two statistical test methods, namely, the likelihood ratio test and the Wald–Wolfowitz runs test. The results of the two statistical tests were substantially different; critical cube sizes of 13 m and 12 m were estimated by the Wald–Wolfowitz runs test and the likelihood ratio test, respectively. Because the different test methods emphasize different considerations and impact factors, considering a result that these two tests accept, the larger cube size, 13 m, was selected as the geometrical REV size of the fractured rock mass at the Maji dam site in China.
Effects of Added Mass and Structural Damping on Dynamic Responses of a 3D Wedge Impacting on Water
Authors: Yu Pengyao , Ong Muk Chen , Li Hui
Published: May 2018

The impact between the wave and the bottom of a high-speed vessel is often simplified as water-entry problems of wedges. Most investigations focus on the water entry of two dimensional (2D) wedges. The effects of added mass and structural damping are still not fully investigated. By combining the normal mode method, the hydrodynamic impact model of rigid wedges and the potential flow theory, a dynamic model for predicting the response of a three dimensional (3D) wedge impacting on water with a constant velocity is established in this paper. The present model can selectively consider the effects of the added mass and the structural damping. The present method has been validated through comparisons with results of published literatures and commercial software. It is found that the added mass can increase the stress response before the flow separation, and reduce the vibration frequency after the flow separation. Due to the effect of the added mass, the stress response of some positions after the flow separation is even higher than that before the flow separation. The structural damping has a negligible effect on the stress before the flow separation, but it can reduce vibration stress after the flow separation.
An Improved Method for Reconfiguring and Optimizing Electrical Active Distribution Network Using Evolutionary Particle Swarm Optimization
Authors: Napis Nur Faziera , Abd. Kadir Aida Fazliana , Khatib Tamer , Hassan Elia Erwani , Sulaima Mohamad Fani
Published: May 2018

The presence of optimized distributed generation (DG) with suitable distribution network reconfiguration (DNR) in the electrical distribution network has an advantage for voltage support, power losses reduction, deferment of new transmission line and distribution structure and system stability improvement. However, installation of a DG unit at non-optimal size with non-optimal DNR may lead to higher power losses, power quality problem, voltage instability and incremental of operational cost. Thus, an appropriate DG and DNR planning are essential and are considered as an objective of this research. An effective heuristic optimization technique named as improved evolutionary particle swarm optimization (IEPSO) is proposed in this research. The objective function is formulated to minimize the total power losses (TPL) and to improve the voltage stability index (VSI). The voltage stability index is determined for three load demand levels namely light load, nominal load, and heavy load with proper optimal DNR and DG sizing. The performance of the proposed technique is compared with other optimization techniques, namely particle swarm optimization (PSO) and iteration particle swarm optimization (IPSO). Four case studies on IEEE 33-bus and IEEE 69-bus distribution systems have been conducted to validate the effectiveness of the proposed IEPSO. The optimization results show that, the best achievement is done by IEPSO technique with power losses reduction up to 79.26%, and 58.41% improvement in the voltage stability index. Moreover, IEPSO has the fastest computational time for all load conditions as compared to other algorithms.
Propagation of Elastic Waves in a One-Dimensional High Aspect Ratio Nanoridge Phononic Crystal
Authors: Gueddida Abdellatif , Pennec Yan , El Boudouti El Houssaine , Fytas George , Djafari Rouhani Bahram
Published: May 2018

We investigate the propagation of elastic waves in a one-dimensional (1D) phononic crystal constituted by high aspect ratio epoxy nanoridges that have been deposited at the surface of a glass substrate. With the help of the finite element method (FEM), we calculate the dispersion curves of the modes localized at the surface for propagation both parallel and perpendicular to the nanoridges. When the direction of the wave is parallel to the nanoridges, we find that the vibrational states coincide with the Lamb modes of an infinite plate that correspond to one nanoridge. When the direction of wave propagation is perpendicular to the 1D nanoridges, the localized modes inside the nanoridges give rise to flat branches in the band structure that interact with the surface Rayleigh mode, and possibly open narrow band gaps. Filling the nanoridge structure with a viscous liquid produces new modes that propagate along the 1D finite height multilayer array.
Bias Stability Enhancement in Thin-Film Transistor with a Solution-Processed ZrO2 Dielectric as Gate Insulator
Authors: Zhou Shangxiong , Fang Zhiqiang , Ning Honglong , Cai Wei , Zhu Zhennan , Wei Jinglin , Lu Xubing , Yuan Weijian , Yao Rihui , Peng Junbiao
Published: May 2018

In this paper, a high-k metal-oxide film (ZrO2) was successfully prepared by a solution-phase method, and whose physical properties were measured by X-ray diffraction (XRD), X-ray reflectivity (XRR) and atomic force microscopy (AFM). Furthermore, indium–gallium–zinc oxide thin-film transistors (IGZO-TFTs) with high-k ZrO2 dielectric layers were demonstrated, and the electrical performance and bias stability were investigated in detail. By spin-coating 0.3 M precursor six times, a dense ZrO2 film, with smoother surface and fewer defects, was fabricated. The TFT devices with optimal ZrO2 dielectric exhibit a saturation mobility up to 12.7 cm2 V−1 s−1, and an on/off ratio as high as 7.6 × 105. The offset of the threshold voltage was less than 0.6 V under positive and negative bias stress for 3600 s.
Analysis of Blur Measure Operators for Single Image Blur Segmentation
Authors: Ali Usman , Mahmood Muhammad Tariq
Published: May 2018

Blur detection and segmentation for a single image without any prior information is a challenging task. Numerous techniques for blur detection and segmentation have been proposed in the literature to ultimately restore the sharp images. These techniques use different blur measures in different settings, and in all of them, blur measure plays a central role among all other steps. Blur measure operators have not been analyzed comparatively for both of the spatially-variant defocus and motion blur cases. In this paper, we provide the performance analysis of the state-of-the-art blur measure operators under a unified framework for blur segmentation. A large number of blur measure operators are considered for applying on a diverse set of real blurry images affected by different types and levels of blur and noise. The initial blur maps then are segmented into blurred and non-blurred regions. In order to test the performance of blur measure operators in segmentation process in equal terms, it is crucial to consider the same intermediate steps involved in the blur segmentation process for all of the blur measure operators. The performance of the operators is evaluated by using various qualitative measures. Results reveal that the blur measure operators perform well under certain condition and factors. However, it has been observed that some operators perform adequately overall well or worse against almost all imperfections that prevail over the real-world images.
Non-Contact and Real-Time Measurement of Kolsky Bar with Temporal Speckle Interferometry
Authors: Yang Shanwei , Gao Zhan , Ruan Haihui , Gao Chenjia , Wang Xu , Sun Xiang , Wen Xin
Published: May 2018

In this paper, a new non-contact and real-time measurement system for Kolsky bars is presented. This system uses two sets of temporal speckle interferometry in-plane displacement measurement devices to replace two strain gauges of conventional Kolsky bars. The in-plane displacement measurement of the Kolsky bar is mainly intended to provide a new test method for the dynamic mechanical properties of small-size material samples with diameters below 2 mm. This method is non-contact, does not require any intermediate medium, and can make the Kolsky bar applicable to characterizing the dynamic mechanical properties of materials under higher strain rates and smaller size conditions. The measuring devices and principles are described. In addition, a preliminary experiment is carried out to demonstrate the performance of this new device.
Multivariate Interpolation of Wind Field Based on Gaussian Process Regression
Authors: Feng Miao , Zhang Weimin , Zhu Xiangru , Duan Boheng , Zhu Mengbin , Xing De
Published: May 2018

The resolution of the products of numerical weather prediction is limited by the resolution of numerical models and computing resources, which can be improved accurately by a well-chosen interpolation algorithm. This paper is intended to improve the accuracy of spatial interpolation towards wind fields. A new composited multi-scale anisotropic kernel function for weather processes using two-dimensional space information is proposed. To fix the underfitting in this kernel caused by unilateral space information, multiple variables (wind direction, air temperature, and atmospheric pressure) are introduced, which generates a multivariate correction model based on the novel kernel function and Gaussian process regression. Focusing on different weather processes, two multivariate correction models are designed. The new models pave a new way to employ multi-scale local information, and extract the anisotropy and structure information. The experiments on 10 m wind fields for the weather processes without cyclones and for the weather processes with cyclones validate the efficiency. The mean RMSE of the multivariate correction model for the weather processes without cyclones is reduced by around 15% for the u wind component compared with that of a simple composited kernel. For the weather processes with cyclones, the mean RMSE of the novel model declines by around 55% compared to that of spline, and by about 95% compared to that of back propagation neural networks.
Antibiofilm Peptides and Peptidomimetics with Focus on Surface Immobilization
Authors: Andrea Athina , Molchanova Natalia , Jenssen Håvard
Published: May 2018

Bacterial biofilms pose a major threat to public health, as they are associated with at least two thirds of all infections. They are highly resilient and render conventional antibiotics inefficient. As a part of the innate immune system, antimicrobial peptides have drawn attention within the last decades, as some of them are able to eradicate biofilms at sub-minimum inhibitory concentration (MIC) levels. However, peptides possess a number of disadvantages, such as susceptibility to proteolytic degradation, pH and/or salinity-dependent activity and loss of activity due to binding to serum proteins. Hence, proteolytically stable peptidomimetics were designed to overcome these drawbacks. This paper summarizes the current peptide and peptidomimetic strategies for combating bacteria-associated biofilm infections, both in respect to soluble and surface-functionalized solutions.
The Crosstalk of Endoplasmic Reticulum (ER) Stress Pathways with NF-κB: Complex Mechanisms Relevant for Cancer, Inflammation and Infection
Authors: Schmitz M. Lienhard , Shaban M. Samer , Albert B. Vincent , Gökçen Anke , Kracht Michael
Published: May 2018

Stressful conditions occuring during cancer, inflammation or infection activate adaptive responses that are controlled by the unfolded protein response (UPR) and the nuclear factor of kappa light polypeptide gene enhancer in B-cells (NF-κB) signaling pathway. These systems can be triggered by chemical compounds but also by cytokines, toll-like receptor ligands, nucleic acids, lipids, bacteria and viruses. Despite representing unique signaling cascades, new data indicate that the UPR and NF-κB pathways converge within the nucleus through ten major transcription factors (TFs), namely activating transcription factor (ATF)4, ATF3, CCAAT/enhancer-binding protein (CEBP) homologous protein (CHOP), X-box-binding protein (XBP)1, ATF6α and the five NF-κB subunits. The combinatorial occupancy of numerous genomic regions (enhancers and promoters) coordinates the transcriptional activation or repression of hundreds of genes that collectively determine the balance between metabolic and inflammatory phenotypes and the extent of apoptosis and autophagy or repair of cell damage and survival. Here, we also discuss results from genetic experiments and chemical activators of endoplasmic reticulum (ER) stress that suggest a link to the cytosolic inhibitor of NF-κB (IκB)α degradation pathway. These data show that the UPR affects this major control point of NF-κB activation through several mechanisms. Taken together, available evidence indicates that the UPR and NF-κB interact at multiple levels. This crosstalk provides ample opportunities to fine-tune cellular stress responses and could also be exploited therapeutically in the future.
The NF-κB Activating Pathways in Multiple Myeloma
Authors: Roy Payel , Sarkar Uday Aditya , Basak Soumen
Published: May 2018

Multiple myeloma(MM), an incurable plasma cell cancer, represents the second most prevalent hematological malignancy. Deregulated activity of the nuclear factor kappaB (NF-κB) family of transcription factors has been implicated in the pathogenesis of multiple myeloma. Tumor microenvironment-derived cytokines and cancer-associated genetic mutations signal through the canonical as well as the non-canonical arms to activate the NF-κB system in myeloma cells. In fact, frequent engagement of both the NF-κB pathways constitutes a distinguishing characteristic of myeloma. In turn, NF-κB signaling promotes proliferation, survival and drug-resistance of myeloma cells. In this review article, we catalog NF-κB activating genetic mutations and microenvironmental cues associated with multiple myeloma. We then describe how the individual canonical and non-canonical pathways transduce signals and contribute towards NF-κB -driven gene-expressions in healthy and malignant cells. Furthermore, we discuss signaling crosstalk between concomitantly triggered NF-κB pathways, and its plausible implication for anomalous NF-κB activation and NF-κB driven pro-survival gene-expressions in multiple myeloma. Finally, we propose that mechanistic understanding of NF-κB deregulations may provide for improved therapeutic and prognostic tools in multiple myeloma.
Metabolic Regulation of Hypoxia-Inducible Transcription Factors: The Role of Small Molecule Metabolites and Iron
Authors: Bailey Peter S. J. , Nathan James A.
Published: May 2018

Hypoxia-inducible transcription factors (HIFs) facilitate cellular adaptations to low-oxygen environments. However, it is increasingly recognised that HIFs may be activated in response to metabolic stimuli, even when oxygen is present. Understanding the mechanisms for the crosstalk that exists between HIF signalling and metabolic pathways is therefore important. This review focuses on the metabolic regulation of HIFs by small molecule metabolites and iron, highlighting the latest studies that explore how tricarboxylic acid (TCA) cycle intermediates, 2-hydroxyglutarate (2-HG) and intracellular iron levels influence the HIF response through modulating the activity of prolyl hydroxylases (PHDs). We also discuss the relevance of these metabolic pathways in physiological and disease contexts. Lastly, as PHDs are members of a large family of 2-oxoglutarate (2-OG) dependent dioxygenases that can all respond to metabolic stimuli, we explore the broader role of TCA cycle metabolites and 2-HG in the regulation of 2-OG dependent dioxygenases, focusing on the enzymes involved in chromatin remodelling.
Levels of Nature and Stress Response
Authors: Ewert Alan , Chang Yun
Published: May 2018

A growing number of studies have shown that visiting green spaces and being exposed to natural environments can reduce psychological stress. A number of questions concerning the effects of natural environments on levels of stress remain including, “Are activities engaged in natural environments more or less beneficial at reducing stress when compared to those done in more urban settings?” This study examined this question from the perspective of “levels of nature”. That is, data on levels of stress were collected from three sites, one site having wilderness-like characteristics, a second site representing a municipal-type park, and a third site representing a built environment (indoor exercise facility) within a city. Data were generated using biophysical markers (cortisol and amylase) and a psychological measure within a pre- and post-visit format. Findings suggest that visiting natural environments can be beneficial in reducing both physical and psychological stress levels, with visitors to a natural environment reporting significantly lower levels of stress than their counterparts visiting a more urbanized outdoor setting or indoor exercise facility.
The Pros and Cons of Polydopamine-Sensitized Titanium Oxide for the Photoreduction of CO2
Authors: Wang Tongyao , Xia Ming , Kong Xueqian
Published: May 2018

Photocatalytic reduction of CO2 into fuels is a promising route to reduce greenhouse gas emission, and it demands high-performance photocatalysts that can use visible light in the solar spectrum. Due to its broadband light adsorption, polydopamine (PDA) is considered as a promising photo-sensitization material for semiconductor photocatalysts. In this work, titanium oxides have been coated with PDA through an in-situ oxidation polymerization method to pursue CO2 reduction under visible light. We have shown that the surface coated PDA with a thickness of around 1 nm can enhance the photocatalytic performance of anatase under visible light to reduce CO2 into CO. Assisted with additional UV-vis adsorption and photoluminescence characterizations, we confirmed the sensitization effect of PDA on anatase. Furthermore, our study shows that thicker PDA coating might not be favorable, as PDA could decompose under both visible and UV-vis light irradiations. 13C solid-state nuclear magnetic resonance showed structural differences between thin and thick PDA coatings and revealed compositional changes of PDA after light irradiation.
Biocatalysis and Biotransformations
Authors: Ferrer Manuel
Published: May 2018

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Photodegradation of 1,2,4-Trichlorobenzene on Montmorillonite–TiO2 Nanocomposites
Authors: González Beatriz , Muñoz Bárbara , Vicente Miguel Angel , Trujillano Raquel , Rives Vicente , Gil Antonio , Korili Sophia
Published: May 2018

Montmorillonite–TiO2 nanocomposites were prepared using two different methods (ultrasonic or stirring) and using titanium(IV) isopropoxide as precursor. The solids were characterized by element chemical analysis, X-ray diffraction, FTIR spectroscopy, thermal analyses, and nitrogen adsorption. The evolution of the properties as a function of the preparation method was discussed. These nanocomposites were used as catalysts for the photodegradation of 1,2,4-trichlorobenzene. The degradation pathway and the nature of the by–products were investigated by mass spectrometry.
Twin Domains in Organometallic Halide Perovskite Thin-Films
Authors: Liu Wei , Liu Yang , Wang Ju , Wu Cuncun , Liu Congyue , Xiao Lixin , Chen Zhijian , Wang Shufeng , Gong Qihuang
Published: May 2018

The perovskite is a class of material with crystalline structure similar to CaTiO3. In recent years, the organic-inorganic hybrid metallic halide perovskite has been widely investigated as a promising material for a new generation photovoltaic device, whose power conversion efficiency (PCE) record reaches 22.7%. One of its underlying morphological characteristics is the twin domain within those sub-micron sized crystal grains in perovskite thin films. This is important for discussion since it could be the key for understanding the fundamental mechanism of the device’s high performance, such as long diffusion distance and low recombination rate. This review aims to summarize studies on twin domains in perovskite thin films, in order to figure out its importance, guide the current studies on mechanism, and design new devices. Firstly, we introduce the research history and characteristics of widely known twin domains in inorganic perovskite BaTiO3. We then focus on the impact of the domain structure emerging in hybrid metallic halide perovskite thin films, including the observation and discussion on ferroelectricity/ferroelasity. The theoretical analysis is also presented in this review. Finally, we present a spectroscopic method, which can reveal the generality of twin domains within perovskite thin films. We anticipate that this summary on the structural and physical properties of organometallic halide perovskite will help to understand and improve the high-performance of photovoltaic devices.
High-Pressure, High-Temperature Behavior of Silicon Carbide: A Review
Authors: Daviau Kierstin , Lee Kanani
Published: May 2018

The high-pressure behavior of silicon carbide (SiC), a hard, semi-conducting material commonly known for its many polytypic structures and refractory nature, has increasingly become the subject of current research. Through work done both experimentally and computationally, many interesting aspects of high-pressure SiC have been measured and explored. Considerable work has been done to measure the effect of pressure on the vibrational and material properties of SiC. Additionally, the transition from the low-pressure zinc-blende B3 structure to the high-pressure rocksalt B1 structure has been measured by several groups in both the diamond-anvil cell and shock communities and predicted in numerous computational studies. Finally, high-temperature studies have explored the thermal equation of state and thermal expansion of SiC, as well as the high-pressure and high-temperature melting behavior. From high-pressure phase transitions, phonon behavior, and melting characteristics, our increased knowledge of SiC is improving our understanding of its industrial uses, as well as opening up its application to other fields such as the Earth sciences.
One-Step Synthesis of Cu–ZnO@C from a 1D Complex [Cu0.02Zn0.98(C8H3NO6)(C12H8N2)]n for Catalytic Hydroxylation of Benzene to Phenol
Authors: Wang Guanghui , Yan Zheng , Song Li , Li Lei , Zhu Jie , Wang Haidong
Published: May 2018

A novel one-dimensional bimetallic complex [Cu0.02Zn0.98(C8H3NO6)(C12H8N2)]n (“Complex”) has been synthesized by a hydrothermal method. A Cu–ZnO@C composite was obtained by a one-step pyrolysis of Complex. Correlated with the characterization results, it is confirmed that both metallic Cu0 and ZnO nanoparticles were highly dispersed on/in the carbon substrate. This simple one-step pyrolysis method avoids the high-temperature pretreatment under H2 commonly required for preparation of such Cu–ZnO catalysts. The Cu–ZnO@C composite was tested with respect to its catalytic activities for the hydroxylation of benzene to phenol with H2O2. The results indicate that the benzene conversion, phenol yield, and phenol selectivity reached the maximum values (55.7%, 32%, and 57.5%, respectively) at Complex carbonized at 600 °C, and were higher than those of the commercial mixed sample. Compared with the other candidate catalysts, the turnover frequency (TOF) of our Cu–ZnO@C catalyst (117.9 mmol mol−1 s−1) can be ranked at the top. The higher catalytic activities should be due to the highly dispersed metallic Cu0 and ZnO particles as well as their synergistic interaction.
Recent Insights into Protein Crystal Nucleation
Authors: Nanev Christo N.
Published: May 2018

Homogeneous nucleation of protein crystals in solution is tackled from both thermodynamic and energetic perspectives. The entropic contribution to the destructive action of water molecules which tend to tear up the crystals and to their bond energy is considered. It is argued that, in contrast to the crystals’ bond energy, the magnitude of destructive energy depends on the imposed supersaturation. The rationale behind the consideration presented is that the critical nucleus size is determined by the balance between destructive and bond energies. By summing up all intra-crystal bonds, the breaking of which is needed to disintegrate a crystal into its constituting molecules, and using a crystallographic computer program, the bond energy of the closest-packed crystals is calculated (hexagonal closest-packed crystals are given as an example). This approach is compared to the classical mean work of separation (MWS) method of Stranski and Kaischew. While the latter is applied merely for the so-called Kossel-crystal and vapor grown crystals, the approach presented can be used to establish the supersaturation dependence of the protein crystal nucleus size of arbitrary lattice structures.
Synthesis and Crystal Structures of Cadmium(II) Cyanide with Branched-Butoxyethanol
Authors: Kawasaki Takeshi , Kitazawa Takafumi
Published: May 2018

Two novel 3D cadmium(II) cyanide coordination polymers with branched-butoxyethanol compounds (iBucel = iso-butoxyethanol, tBucel = tert-butoxyethanol), [{Cd(CN)2(iBucel)2}{Cd(CN)2(H2O)(iBucel)}2{Cd(CN)2}6∙2(iBucel)]n I and [{Cd(CN)2(H2O)1.06(tBucel)0.94}{Cd(CN)2(tBucel)}2{Cd(CN)2}2∙1.06(tBucel)]n II, were synthesized and characterized by structural determination. Complex I contains two distinct Cd(II) coordination geometries: octahedral and tetrahedral. In contrast, complex II contains three distinct Cd(II) coordination geometries: octahedral, square-pyramidal, and tetrahedral. In the two complexes, branched-butoxyethanol molecules behave as both a ligand and a guest in the Cd(CN)2 cavities. The framework in I contains octahedral and tetrahedral Cd(II) in a 3:6 ratio. In I, the coordination environments of octahedral Cd(II) are cis-O-Cd-O. The framework in II contains octahedral, square-pyramidal, and tetrahedral Cd(II) in a 1:2:2 ratio. In II, the coordination environment of octahedral Cd(II) is disordered trans-O-Cd-O and the axial oxygen ligand is either a water or tBucel molecule. In II, the square-pyramidal Cd(II) geometry is formed by one tBucel ligand and four cyanide ligands. The Cd(CN)2 frameworks of the two complexes exhibit different structures.
Angiogenesis PET Tracer Uptake (68Ga-NODAGA-E[(cRGDyK)]2) in Induced Myocardial Infarction and Stromal Cell Treatment in Minipigs
Authors: Rasmussen Thomas , Follin Bjarke , Kastrup Jens , Brandt-Larsen Malene , Madsen Jacob , Emil Christensen Thomas , Juhl Morten , Cohen Smadar , Pharao Hammelev Karsten , Holdflod Møller Christian , Peter Goetze Jens , Hasbak Philip , Kjær Andreas
Published: May 2018

Angiogenesis is considered integral to the reparative process after ischemic injury. The αvβ3 integrin is a critical modulator of angiogenesis and highly expressed in activated endothelial cells. 68Ga-NODAGA-E[(cRGDyK)]2 (RGD) is a positron-emission-tomography (PET) ligand targeted towards αvβ3 integrin. The aim was to present data for the uptake of RGD and correlate it with histology and to further illustrate the differences in angiogenesis due to porcine adipose-derived mesenchymal stromal cell (pASC) or saline treatment in minipigs after induction of myocardial infarction (MI). Three minipigs were treated with direct intra-myocardial injection of pASCs and two minipigs with saline. MI was confirmed by 82Rubidium (82Rb) dipyridamole stress PET. Mean Standardized Uptake Values (SUVmean) of RGD were higher in the infarct compared to non-infarct area one week and one month after MI in both pASC-treated (SUVmean: 1.23 vs. 0.88 and 1.02 vs. 0.86, p < 0.05 for both) and non-pASC-treated minipigs (SUVmean: 1.44 vs. 1.07 and 1.26 vs. 1.04, p < 0.05 for both). However, there was no difference in RGD uptake, ejection fractions, coronary flow reserves or capillary density in histology between the two groups. In summary, indications of angiogenesis were present in the infarcted myocardium. However, no differences between pASC-treated and non-pASC-treated minipigs could be demonstrated.