bluuebunny/crossref_metadata_2025 huggingface dataset:
Design and Experimental Investigation of a Piezoelectric Rotation Energy Harvester Using Bistable and Frequency Up-Conversion Mechanisms
Authors: Xie Zhengqiu , Xiong Jitao , Zhang Deqi , Wang Tao , Shao Yimin , Huang Wenbin
Published: August 2018

Harvesting energy from rotational motion for powering low-power electrical devices is attracting increasing research interest in recent years. In this paper, a magnetic-coupled buckled beam piezoelectric rotation energy harvester (MBBP-REH) with bistable and frequency up-conversion is presented to harvest low speed rotational energy with a broadband. A buckled beam attached with piezoelectric patches under dynamical axial load enables the harvester to achieve high output power under small excitation force. The electromechanical coupling dynamical model is developed to characterize the MBBP-REH. Both the simulations and experiments are carried out to evaluate the performance of the harvesters in various conditions under different excitations. The experimental results indicate that the proposed harvester is applicable for low speed rotation and can generate stable output power under wideband rotating excitation. For the harvester with two magnets that produce attractive forces with the center magnet of the buckled beam, the average power is 682.7 μW and the maximum instantaneous power is 1450 μW at 360 r/min.
Modeling of the Mechanical Behavior of 3D Bioplotted Scaffolds Considering the Penetration in Interlocked Strands
Authors: Naghieh Saman , Sarker M. D. , Karamooz-Ravari Mohammad Reza , McInnes Adam D. , Chen Xiongbiao
Published: August 2018

Three-dimensional (3D) bioplotting has been widely used to print hydrogel scaffolds for tissue engineering applications. One issue involved in 3D bioplotting is to achieve the scaffold structure with the desired mechanical properties. To overcome this issue, various numerical methods have been developed to predict the mechanical properties of scaffolds, but limited by the imperfect representation of one key feature of scaffolds fabricated by 3D bioplotting, i.e., the penetration or fusion of strands in one layer into the previous layer. This paper presents our study on the development of a novel numerical model to predict the elastic modulus (one important index of mechanical properties) of 3D bioplotted scaffolds considering the aforementioned strand penetration. For this, the finite element method was used for the model development, while medium-viscosity alginate was selected for scaffold fabrication by the 3D bioplotting technique. The elastic modulus of the bioplotted scaffolds was characterized using mechanical testing and results were compared with those predicted from the developed model, demonstrating a strong congruity between them. Once validated, the developed model was also used to investigate the effect of other geometrical features on the mechanical behavior of bioplotted scaffolds. Our results show that the penetration, pore size, and number of printed layers have significant effects on the elastic modulus of bioplotted scaffolds; and also suggest that the developed model can be used as a powerful tool to modulate the mechanical behavior of bioplotted scaffolds.
Extended Analysis of Ar III and Ar IV
Authors: Raineri Mónica , Mejia Castellanos Roberto E. , Gallardo Mario , Reyna Almandos Jorge
Published: August 2018

A pulsed discharge light source was used to study the two and three times ionized argon (Ar II, Ar III) spectra in the 480–6218 Å region. A set of 129 transitions of Ar III and 112 transitions of Ar IV were classified for the first time. We extended the analysis of Ar III to five new energy levels belonging to 3s23p34d, 3s23p35s odd configurations. For Ar IV, 10 new energy levels of the 3s23p23d and 3s23p24p even and odd configurations, respectively, are presented. For the prediction of energy levels, line transitions, and transition probabilities, relativistic Hartree–Fock calculations were used.
Expression Analysis of Autophagy Related Markers LC3B, p62 and HMGB1 Indicate an Autophagy-Independent Negative Prognostic Impact of High p62 Expression in Pulmonary Squamous Cell Carcinomas
Authors: Langer Rupert , Neppl Christina , Keller Manuel D. , Schmid Ralph A. , Tschan Mario P. , Berezowska Sabina
Published: August 2018

Autophagy is involved in maintaining cellular homeostasis under stress conditions. It also plays an important role in various diseases including cancer. Pulmonary squamous cell carcinomas (pSQCC) at present lack targetable molecular alterations, and demand alternative therapeutic options. We assessed the expression levels of autophagy related proteins LC3B, p62, and HMGB1 in 271 primary resected pSQCC by immunohistochemistry, in correlation with clinical and pathological parameters, as a rationale for a potential autophagy directed therapy. LC3B, p62, and HMGB1 staining showed various patterns. LC3Bhighp62low levels, suggested to indicate intact activated autophagy, were associated with prolonged disease specific survival (DSS) and LC3Bhighp62high levels, indicating activated but late stage impaired autophagy, with shorter DSS (p = 0.024). p62high expression regardless of LC3B, however, showed an even stronger association with shorter DSS (p = 0.015) and was also an independent negative prognostic factor in multivariate analysis (HR = 2.99; 95% CI 1.38–6.52; p = 0.006). HMGB1 expression correlated neither with the expression of LC3B and p62, nor with patients’ outcome. Different states of autophagy characterized by distinct p62 and LC3B expression patterns may be linked to patient’s prognosis in pSQCC. Our results, however, point also to an autophagy independent role of p62 with an even more pronounced prognostic impact compared to autophagy related p62.
Preparation and Characterization of Novel Pharmaceutical Co-Crystals: Ticagrelor with Nicotinamide
Authors: Inam Muhammad , Wu Jiajia , Shen Jie , Phan Chi Uyen , Tang Guping , Hu Xiurong
Published: August 2018

Two new co-crystals, Ticagrelor with Nicotinamide, have been prepared with improved solubility. Because Ticalegor has a poor solubility and dissolution rate, a novel co-crystallization method with structurally homogenous crystalline material, an active pharmaceutical ingredient (API), and co-former indefinite stoichiometric amount has been made to improve Ticagrelor’s solubility. The co-crystal of Ticagrelor (TICA) with Nicotinamide (NCA) was prepared in ratio (1:1) and confirmed by FTIR, DSC, and XRD characterization. Furthermore, the single crystal structure of TICA-NCA hydrate was analyzed. The solubility of co-crystals was investigated in pH 2 acidic medium, which was a significant improvement as compared to the solubility of a free drug. The in vitro dissolution rate of co-crystal was larger than that of the commercial product.
A Hybrid Fault Diagnosis Approach for Rotating Machinery with the Fusion of Entropy-Based Feature Extraction and SVM Optimized by a Chaos Quantum Sine Cosine Algorithm
Authors: Fu Wenlong , Tan Jiawen , Li Chaoshun , Zou Zubing , Li Qiankun , Chen Tie
Published: August 2018

As crucial equipment during industrial manufacture, the health status of rotating machinery affects the production efficiency and device safety. Hence, it is of great significance to diagnose rotating machinery faults, which can contribute to guarantee the running stability and plan for maintenance, thus promoting production efficiency and economic benefits. For this purpose, a hybrid fault diagnosis model with entropy-based feature extraction and SVM optimized by a chaos quantum sine cosine algorithm (CQSCA) is developed in this research. Firstly, the state-of-the-art variational mode decomposition (VMD) is utilized to decompose the vibration signals into sets of components, during which process the preset parameter K is confirmed with the central frequency observation method. Subsequently, the permutation entropy values of all components are computed to constitute the feature vectors corresponding to different kind of signals. Later, the newly developed sine cosine algorithm (SCA) is employed and improved with chaotic initialization by a Duffing system and quantum technique to optimize the support vector machine (SVM) model, with which the fault pattern is recognized. Additionally, the availability of the optimized SVM with CQSCA was revealed in pattern recognition experiments. Finally, the proposed hybrid fault diagnosis approach was employed for engineering applications as well as contrastive analysis. The comparative results show that the proposed method achieved the best training accuracy 99.5% and best testing accuracy 97.89%. Furthermore, it can be concluded from the boxplots of different diagnosis methods that the stability and precision of the proposed method is superior to those of others.
Enabling Off-Road Autonomous Navigation-Simulation of LIDAR in Dense Vegetation
Authors: Goodin Christopher , Doude Matthew , Hudson Christopher R. , Carruth Daniel W.
Published: August 2018

Machine learning techniques have accelerated the development of autonomous navigation algorithms in recent years, especially algorithms for on-road autonomous navigation. However, off-road navigation in unstructured environments continues to challenge autonomous ground vehicles. Many off-road navigation systems rely on LIDAR to sense and classify the environment, but LIDAR sensors often fail to distinguish navigable vegetation from non-navigable solid obstacles. While other areas of autonomy have benefited from the use of simulation, there has not been a real-time LIDAR simulator that accounted for LIDAR–vegetation interaction. In this work, we outline the development of a real-time, physics-based LIDAR simulator for densely vegetated environments that can be used in the development of LIDAR processing algorithms for off-road autonomous navigation. We present a multi-step qualitative validation of the simulator, which includes the development of an improved statistical model for the range distribution of LIDAR returns in grass. As a demonstration of the simulator’s capability, we show an example of the simulator being used to evaluate autonomous navigation through vegetation. The results demonstrate the potential for using the simulation in the development and testing of algorithms for autonomous off-road navigation.
Experimental and Numerical Study of an Electrical Thermal Storage Device for Space Heating
Authors: Xu Guizhi , Hu Xiao , Liao Zhirong , Xu Chao , Yang Cenyu , Deng Zhanfeng
Published: August 2018

An electrical thermal storage (ETS) device for space heating is designed in this study. The proposed device is charged by the off-peak electricity and releases its thermal energy to warm the space all day long. The natural convection occurring in the flow channel drives the flowing of air to be heated up and warm the space. The dynamic process of a fully charging/discharging cycle of the device is tested. Meanwhile, a three-dimensional model is developed to simulate the transient thermal behavior. It is found that the experimental and numerical results agree with each other which indicates the validation of the proposed numerical model. The results show that the temperatures of the bricks and the outlet air can be as high as 1002 K and 835 K, respectively. The natural convection occurring in the flow channel transfers 40.4% of the total electrical heating energy to the space for the charging process and 26.9% for the discharging process. Heat losses to the space through the adiabatic material shares 13.3% of the total heating energy for the charging process and 7.2% for the discharging process. Based on those findings, three methods are recommended to improve the device in the successive research.
On the Injection of Sub/Inter-Harmonic Current Components for Active Anti-Islanding Purposes
Authors: Voglitsis Dionisis , Valsamas Fotis , Rigogiannis Nick , Papanikolaou Nick
Published: August 2018

Active anti-islanding schemes that are based on the injection of harmonic currents, such as the measurement of the impedance at a specific frequency or similar techniques, have been proposed for anti-islanding protection in photovoltaic (PV) systems due to their low impact on inverter active power, their fast detection response in island, and reduced non-detection zone (NDZ). Integer multiples of the fundamental frequency as well as sub/inter-harmonics have both been used for the implementation of those schemes. Although utilization of sub/inter-harmonics present significant advantages, they also present significant limitations. This work investigates those limitations, particularly the ones that are caused by the parallel operation of multiple inverters. In addition, the distortion effect that is caused in the output current of the widely used PV microinverters with pseudo dc-link (PV Pdc-MICs) is discussed and thoroughly analyzed. It is concluded that when the injection is performed asynchronously (without communication among the inverters) sub/inter-harmonics are unsuitable for utilization under the parallel operation of multiple inverters. It is worth noting that a strategy is proposed in the current work that retains the effectiveness of the harmonic injection scheme under the injection of integer multiples of fundamental frequency. On the other hand, the distortion effect that is caused by the sub/inter-harmonics on PV Pdc-MICs output current, has been evaluated as insignificant when harmonics are used for anti-islanding purposes. Finally, the theoretical/mathematical outcomes of this work are supported by simulation and experimental results.
Computational Fluid Dynamics Approach for Performance Prediction in a Zinc–Air Fuel Cell
Authors: Huang K. David , Sangeetha Thangavel , Cheng Wu-Fu , Lin Chunyo , Chen Po-Tuan
Published: August 2018

In this study, we investigated the development of a computational fluid dynamics (CFD) model for simulating the physical and chemical processes in a zinc (Zn)–air fuel cell. Theoretically, the model was based on time-dependent, three-dimensional conservation equations of mass, momentum, and species concentration. The complex electrochemical reactions occurring within the porous electrodes were described by the Butler–Volmer equation with velocity, pressure, current density, and electronic and ionic phase potentials computed in electrodes. The Zn–air fuel cell for the present study comprised of four major components, such as a porous Zn anode electrode, air cathode electrode, liquid potassium hydroxide (KOH) electrolyte, and air flow channels. The numerical results were first compared with the experiments, showing close agreement with the predicted and experimental values of the measured voltage–current data of a single Zn–air fuel cell. Numerical results also exhibited mass fraction contours of oxygen (O2) and zinc oxide (ZnO) in the mid-cross-sectional plane. A parametric study was extended to assess the performance of a Zn–air fuel cell at various cathode and electrolyte parameters.
Bamboo Fiber and Sugarcane Skin as a Bio-Briquette Fuel
Authors: Brunerová Anna , Roubík Hynek , Brožek Milan
Published: August 2018

The present study deals with the issue of bio-briquette fuel produced from specific agriculture residues, namely bamboo fiber (BF) and sugarcane skin (SCS). Both materials originated from Thừa Thiên Huế province in central Vietnam and were subjected to analysis of their suitability for such a purpose. A densification process using a high-pressure briquetting press proved its practicability for producing bio-briquette fuel. Analysis of fuel parameters exhibited a satisfactory level of all measured quality indicators: ash content Ac (BF—1.16%, SCS—8.62%) and net calorific value NCV (BF—16.92 MJ∙kg−1, SCS—17.23 MJ∙kg−1). Equally, mechanical quality indicators also proved satisfactory; bio-briquette samples’ mechanical durability DU occurred at an extremely high level (BF—97.80%, SCS—97.70%), as did their bulk density ρ (BF—986.37 kg·m−3, SCS—1067.08 kg·m−3). Overall evaluation of all observed results and factors influencing the investigated issue proved that both waste biomass materials, bamboo fiber and sugarcane skin, represent suitable feedstock materials for bio-briquette fuel production, and produced bio-briquette samples can be used as high-quality fuels.
Cross-Border Effects on Swiss Electricity Prices in the Light of the Energy Transition
Authors: Frauendorfer Karl , Paraschiv Florentina , Schürle Michael
Published: August 2018

Given the perspective of the Swiss energy policy to support investments in renewable energy sources, it becomes highly relevant at this point to understand cross-border effects of imported electricity on the Swiss electricity prices. We found that German (Phelix) and Swiss (Swissix) electricity prices are cointegrated, given that the two markets are interconnected. We examined the cross-border effects of the German market fundamentals on Swissix, taking into account seasonality aspects. In the context of a dynamic fundamental model, we found that there is a continuous adaption process of electricity prices to market fundamentals and that this effect depends on the season of the year and the time of the day. Model results reveal the substitution effect between traditional fuels and renewable energies due to their alternative use in production and the shift in the merit order curve. Results are of great relevance to Swiss policy makers: Switzerland imports lower electricity prices due to the energy transition in Germany. In particular, because of the high infeed of PV (photovoltaic) during peak hours, the spread between Swissix peak and off-peak prices narrowed significantly over time. Incentives for investments in renewable energies in Switzerland as well as subsidies for hydropower should be considered in the light of these insights.
Ranking Supply Function and Cournot Equilibria in a Differentiated Product Duopoly with Demand Uncertainty
Authors: Saglam Ismail
Published: August 2018

In this paper, we provide a welfare ranking for the equilibria of the supply function and quantity competitions in a differentiated product duopoly with demand uncertainty. We prove that the expected consumer surplus is always higher under the supply function competition, irrespective of whether the (duopolistic) products are substitutes, complements, or independent. Numerical simulations suggest that if the products are either complements or independent, or if they have an extremely low degree of substitution, then the supply function competition can always be Pareto superior to the quantity competition in terms of the producers’ and consumers’ welfares. Moreover, if the degree of product substitution is not extremely low, then the supply function competition can be Pareto superior to the quantity competition if and only if the size of the demand uncertainty is sufficiently large to exceed a critical level. We find that this critical level of demand uncertainty becomes higher when the duopolistic products are less differentiated. Additionally, this critical level is nonincreasing both in the marginal cost of producing a unit output and in the own-price sensitivity of each inverse demand curve when all other parameters are fixed. Our results imply that in electricity markets with differentiated products, the regulators should not intervene to impose the quantity competition in favor of the supply function competition unless the degree of product substitution is sufficiently high and the predicted demand fluctuations are sufficiently small.
Neo-Domestication of an Interspecific Tetraploid Helianthus annuus × Helianthus tuberous Population That Segregates for Perennial Habit
Authors: Kantar Michael B. , Hüber Sariel , Herman Adam , Bock Dan G. , Baute Greg , Betts Kevin , Ott Matthew , Brandvain Yaniv , Wyse Donald , Stupar Robert M. , Rieseberg Loren H.
Published: August 2018

Perennial agriculture has been proposed as an option to improve the sustainability of cropping systems, by increasing the efficiency of resource use, while also providing ecosystem services. Neo-domestication, the contemporary domestication of plants that have not previously been used in agriculture, can be used to generate new crops for these systems. Here we explore the potential of a tetraploid (2n = 4x = 68) interspecific hybrid sunflower as a perennial oilseed for use in multifunctional agricultural systems. A population of this novel tetraploid was obtained from crosses between the annual diploid oilseed crop Helianthus annuus (2n = 2x = 34) and the perennial hexaploid tuber crop Helianthus tuberosus (2n = 6x = 102). We selected for classic domestication syndrome traits for three generations. Substantial phenotypic gains were made, in some cases approaching 320%. We also analyzed the genetic basis of tuber production (i.e., perenniality), with the goal of obtaining molecular markers that could be used to facilitate future breeding in this system. Results from quantitative trait locus (QTL) mapping suggest that tuber production has an oligogenic genetic basis. Overall, this study indicates that substantial gains towards domestication goals can be achieved over contemporary time scales.
What Does the Future Hold for Yellow Fever Virus? (II)
Authors: Klitting Raphaëlle , Fischer Carlo , Drexler Jan F. , Gould Ernest A. , Roiz David , Paupy Christophe , De Lamballerie Xavier
Published: August 2018

As revealed by the recent resurgence of yellow fever virus (YFV) activity in the tropical regions of Africa and South America, YFV control measures need urgent rethinking. Over the last decade, most reported outbreaks occurred in, or eventually reached, areas with low vaccination coverage but that are suitable for virus transmission, with an unprecedented risk of expansion to densely populated territories in Africa, South America and Asia. As reflected in the World Health Organization’s initiative launched in 2017, it is high time to strengthen epidemiological surveillance to monitor accurately viral dissemination, and redefine vaccination recommendation areas. Vector-control and immunisation measures need to be adapted and vaccine manufacturing must be reconciled with an increasing demand. We will have to face more yellow fever (YF) cases in the upcoming years. Hence, improving disease management through the development of efficient treatments will prove most beneficial. Undoubtedly, these developments will require in-depth descriptions of YFV biology at molecular, physiological and ecological levels. This second section of a two-part review describes the current state of knowledge and gaps regarding the molecular biology of YFV, along with an overview of the tools that can be used to manage the disease at the individual, local and global levels.
Changes of Soil Microbiological Properties during Grass Litter Decomposition in Loess Hilly Region, China
Authors: Xiang Yun , An Shaoshan , Cheng Man , Liu Lijun , Xie Ying
Published: August 2018

Litter, the link between soil and plant, is an important part of nutrient return to soil. Deeply understanding the effect of litter decomposition on soil microbiological properties is important for the sustainable development of grasslands. Three plants (Thymus quinquecostatus Celak., Stipa bungeana Trin. and Artemisia sacrorum ledeb.) leaf litter were selected. A simulation experiment using the nylon bag method was conducted to measure the soil microbial biomass carbon and nitrogen, and soil enzyme activity during litter decomposition. The results showed that the decomposition of three leaf litter enhanced soil microbial carbon and nitrogen. The change rate of soil microbial carbon and nitrogen decreased as Ar.S > St.B > Th.Q. The activities of soil invertase, soil urease, and soil nitrate reductase were significantly improved by the coverage of leaf litter. After 741-day litter decomposition, the change rate of soil invertase was from 16.7% to 33.2%. The change rate of soil urease was highest in the Th.Q treatment; St.B treatment and Ar.S treatment followed, and lowest in the control. The change rates of soil nitrate reductase in the St.B and Ar.S treatment were >1000% higher than those of other treatments. The response of soil enzyme activity to litter decomposition “lagged” behind the change of soil microbial biomass. The significant increase of soil microbial biomass and enzyme activity demonstrated that litter decomposition played an important role in maintaining soil ecological function.
Generating a High-Precision True Digital Orthophoto Map Based on UAV Images
Authors: Liu Yu , Zheng Xinqi , Ai Gang , Zhang Yi , Zuo Yuqiang
Published: August 2018

Unmanned aerial vehicle (UAV) low-altitude remote sensing technology has recently been adopted in China. However, mapping accuracy and production processes of true digital orthophoto maps (TDOMs) generated by UAV images require further improvement. In this study, ground control points were distributed and images were collected using a multi-rotor UAV and professional camera, at a flight height of 160 m above the ground and a designed ground sample distance (GSD) of 0.016 m. A structure from motion (SfM), revised digital surface model (DSM) and multi-view image texture compensation workflow were outlined to generate a high-precision TDOM. We then used randomly distributed checkpoints on the TDOM to verify its precision. The horizontal accuracy of the generated TDOM was 0.0365 m, the vertical accuracy was 0.0323 m, and the GSD was 0.0166 m. Tilt and shadowed areas of the TDOM were eliminated so that buildings maintained vertical viewing angles. This workflow produced a TDOM accuracy within 0.05 m, and provided an effective method for identifying rural homesteads, as well as land planning and design.
New Hope for Pancreatic Ductal Adenocarcinoma Treatment Targeting Endoplasmic Reticulum Stress Response: A Systematic Review
Authors: Garcia-Carbonero Nuria , Li Weiyao , Cabeza-Morales Marticela , Martinez-Useros Javier , Garcia-Foncillas Jesus
Published: August 2018

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal types of tumours, and its incidence is rising worldwide. Although survival can be improved by surgical resection when these tumours are detected at an early stage, this cancer is usually asymptomatic, and disease only becomes apparent after metastasis. Several risk factors are associated with this disease, the most relevant being chronic pancreatitis, diabetes, tobacco and alcohol intake, cadmium, arsenic and lead exposure, certain infectious diseases, and the mutational status of some genes associated to a familial component. PDAC incidence has increased in recent decades, and there are few alternatives for chemotherapeutic treatment. Endoplasmic reticulum (ER) stress factors such as GRP78/BiP (78 kDa glucose-regulated protein), ATF6α (activating transcription factor 6 isoform α), IRE1α (inositol-requiring enzyme 1 isoform α), and PERK (protein kinase RNA-like endoplasmic reticulum kinase) activate the transcription of several genes involved in both survival and apoptosis. Some of these factors aid in inducing a non-proliferative state in cancer called dormancy. Modulation of endoplasmic reticulum stress could induce dormancy of tumour cells, thus prolonging patient survival. In this systematic review, we have compiled relevant results concerning those endoplasmic reticulum stress factors involved in PDAC, and we have analysed the mechanism of dormancy associated to endoplasmic reticulum stress and its potential use as a chemotherapeutic target against PDAC.
Advances in Imaging Specific Mediators of Inflammatory Bowel Disease
Authors: Dmochowska Nicole , Wardill Hannah R. , Hughes Patrick A.
Published: August 2018

Inflammatory bowel disease (IBD) is characterized by chronic remitting and relapsing inflammation of the lower gastrointestinal tract. The etiology underlying IBD remains unknown, but it is thought to involve a hypersensitive immune response to environmental antigens, including the microbiota. Diagnosis and monitoring of IBD is heavily reliant on endoscopy, which is invasive and does not provide information regarding specific mediators. This review describes recent developments in imaging of IBD with a focus on positron emission tomography (PET) and single-photon emission computed tomography (SPECT) of inflammatory mediators, and how these developments may be applied to the microbiota.
Update in Spontaneous Coronary Artery Dissection
Authors: Ingrassia Joseph , Diver Daniel , Vashist Aseem
Published: August 2018

There has been increased awareness in the understanding and recognition of spontaneous coronary artery disease. Diagnosing this condition is of paramount importance as the treatment strategy differs greatly from traditional acute coronary syndrome patient. We review here the current state of management of spontaneous coronary artery disease.
Insights into the Etiology of Mammalian Neural Tube Closure Defects from Developmental, Genetic and Evolutionary Studies
Authors: Juriloff Diana M. , Harris Muriel J.
Published: August 2018

The human neural tube defects (NTD), anencephaly, spina bifida and craniorachischisis, originate from a failure of the embryonic neural tube to close. Human NTD are relatively common and both complex and heterogeneous in genetic origin, but the genetic variants and developmental mechanisms are largely unknown. Here we review the numerous studies, mainly in mice, of normal neural tube closure, the mechanisms of failure caused by specific gene mutations, and the evolution of the vertebrate cranial neural tube and its genetic processes, seeking insights into the etiology of human NTD. We find evidence of many regions along the anterior–posterior axis each differing in some aspect of neural tube closure—morphology, cell behavior, specific genes required—and conclude that the etiology of NTD is likely to be partly specific to the anterior–posterior location of the defect and also genetically heterogeneous. We revisit the hypotheses explaining the excess of females among cranial NTD cases in mice and humans and new developments in understanding the role of the folate pathway in NTD. Finally, we demonstrate that evidence from mouse mutants strongly supports the search for digenic or oligogenic etiology in human NTD of all types.
An X-ray Tomographic Study of Rechargeable Zn/MnO2 Batteries
Authors: Osenberg Markus , Manke Ingo , Hilger André , Kardjilov Nikolay , Banhart John
Published: August 2018

We present non-destructive and non-invasive in operando X-ray tomographic investigations of the charge and discharge behavior of rechargeable alkaline-manganese (RAM) batteries (Zn-MnO2 batteries). Changes in the three-dimensional structure of the zinc anode and the MnO2 cathode material after several charge/discharge cycles were analyzed. Battery discharge leads to a decrease in the zinc particle sizes, revealing a layer-by-layer dissolving behavior. During charging, the particles grow again to almost their initial size and shape. After several cycles, the particles sizes slowly decrease until most of the particles become smaller than the spatial resolution of the tomography. Furthermore, the number of cracks in the MnO2 bulk continuously increases and the separator changes its shape. The results are compared to the behavior of a conventional primary cell that was also charged and discharged several times.
Structure-Function Correlative Microscopy of Peritubular and Intertubular Dentine
Authors: Sui Tan , Dluhoš Jiří , Li Tao , Zeng Kaiyang , Cernescu Adrian , Landini Gabriel , Korsunsky Alexander M.
Published: August 2018

Peritubular dentine (PTD) and intertubular dentine (ITD) were investigated by 3D correlative Focused Ion Beam (FIB)-Scanning Electron Microscopy (SEM)-Energy Dispersive Spectroscopy (EDS) tomography, tapping mode Atomic Force Microscopy (AFM) and scattering-type Scanning Near-Field Optical Microscopy (s-SNOM) mapping. The brighter appearance of PTD in 3D SEM-Backscattered-Electron (BSE) imaging mode and the corresponding higher grey value indicate a greater mineral concentration in PTD (~160) compared to ITD (~152). However, the 3D FIB-SEM-EDS reconstruction and high resolution, quantitative 2D map of the Ca/P ratio (~1.8) fail to distinguish between PTD and ITD. This has been further confirmed using nanoscale 2D AFM map, which clearly visualised biopolymers and hydroxyapatite (HAp) crystallites with larger mean crystallite size in ITD (32 ± 8 nm) than that in PTD (22 ± 3 nm). Correlative microscopy reveals that the principal difference between PTD and ITD arises primarily from the nanoscale packing density of the crystallites bonded together by thin biopolymer, with moderate contribution from the chemical composition difference. The structural difference results in the mechanical properties variation that is described by the parabolic stiffness-volume fraction correlation function introduced here. The obtained results benefit a microstructure-based mechano-chemical model to simulate the chemical etching process that can occur in human dental caries and some of its treatments.
A Within-Host Stochastic Model for Nematode Infection
Authors: Gómez-Corral Antonio , López-García Martín
Published: August 2018

We propose a stochastic model for the development of gastrointestinal nematode infection in growing lambs under the assumption that nonhomogeneous Poisson processes govern the acquisition of parasites, the parasite-induced host mortality, the natural (no parasite-induced) host mortality and the death of parasites within the host. By means of considering a number of age-dependent birth and death processes with killing, we analyse the impact of grazing strategies that are defined in terms of an intervention instant t 0 , which might imply a move of the host to safe pasture and/or anthelmintic treatment. The efficacy and cost of each grazing strategy are defined in terms of the transient probabilities of the underlying stochastic processes, which are computed by means of Strang–Marchuk splitting techniques. Our model, calibrated with empirical data from Uriarte et al and Nasreen et al., regarding the seasonal presence of nematodes on pasture in temperate zones and anthelmintic efficacy, supports the use of dose-and-move strategies in temperate zones during summer and provides stochastic criteria for selecting the exact optimum time instant t 0 when these strategies should be applied.
New Cytotoxic Cyclic Peptide from the Marine Sponge-Associated Nocardiopsis sp. UR67
Authors: Ibrahim Alyaa Hatem , Attia Eman Zekry , Hajjar Dina , Anany Mohamed A. , Desoukey Samar Yehia , Fouad Mostafa Ahmed , Kamel Mohamed Salah , Wajant Harald , Gulder Tobias A. M. , Abdelmohsen Usama Ramadan
Published: August 2018

A new cyclic hexapeptide, nocardiotide A (1), together with three known compounds—tryptophan (2), kynurenic acid (3), and 4-amino-3-methoxy benzoic acid (4)—were isolated and identified from the broth culture of Nocardiopsis sp. UR67 strain associated with the marine sponge Callyspongia sp. from the Red Sea. The structure elucidation of the isolated compounds were determined based on detailed spectroscopic data including 1D and 2D nuclear magnetic resonance (NMR) experimental analyses in combination with high resolution electrospray ionization mass spectrometry (HR-ESI-MS), while the absolute stereochemistry of all amino acids components of nocardiotide A (1) was deduced using Marfey’s method. Additionally, ten known metabolites were dereplicated using HR-ESI-MS analysis. Nocardiotide A (1) displayed significant cytotoxic effects towards the murine CT26 colon carcinoma, human HeLa cervix carcinoma, and human MM.1S multiple myeloma cell lines. The results obtained revealed sponge-associated Nocardiopsis as a substantial source of lead natural products with pronounced pharmacological activities.
Structural Features of Sulfated Glucuronomannan Oligosaccharides and Their Antioxidant Activity
Authors: Jin Weihua , Ren Langlang , Liu Bing , Zhang Quanbin , Zhong Weihong
Published: August 2018

Glucuronomannan oligosaccharides (Gs) were derived from fucoidan, which was extracted from the brown alga Sargassum thunbergii. Sulfated glucuronomannan oligosaccharides (SGs) were obtained by the sulfation of Gs. NMR techniques were used to reveal that the order of sulfation was Man-C6 > Man-C4 > Man-C1R > GlcA-C3 > Man-C3 > GlcA-C2. Finally, the antioxidant activities (hydroxyl radical scavenging activity, superoxide radical scavenging activity, reducing power and DPPH radical scavenging activity) of Gs and SGs were determined. The findings showed that the higher the degree of polymerization, the better the activity, except for the hydroxyl radical scavenging activity. In addition, the higher the sulfate content, the lower the activities for the reducing power and DPPH radical scavenging activity. Opposite results were found for the superoxide radical scavenging activity. Finally, compared with fucoidan, most Gs and SGs had higher antioxidant activity, suggesting that they might be good candidates for antioxidants.
Bioactive Prenyl- and Terpenyl-Quinones/Hydroquinones of Marine Origin †
Authors: García Pablo A. , Hernández Ángela P. , San Feliciano Arturo , Castro Mª Ángeles
Published: August 2018

The sea is a rich source of biological active compounds, among which terpenyl-quinones/hydroquinones constitute a family of secondary metabolites with diverse pharmacological properties. The chemical diversity and bioactivity of those isolated from marine organisms in the last 10 years are summarized in this review. Aspects related to synthetic approaches towards the preparation of improved bioactive analogues from inactive terpenoids are also outlined.
Dietary Nutrients, Proteomes, and Adhesion of Probiotic Lactobacilli to Mucin and Host Epithelial Cells
Authors: Celebioglu Hasan Ufuk , Svensson Birte
Published: August 2018

The key role of diet and environment in human health receives increasing attention. Thus functional foods, probiotics, prebiotics, and synbiotics with beneficial effects on health and ability to prevent diseases are in focus. The efficacy of probiotic bacteria has been connected with their adherence to the host epithelium and residence in the gut. Several in vitro techniques are available for analyzing bacterial interactions with mucin and intestinal cells, simulating adhesion to the host in vivo. Proteomics has monitored and identified proteins of probiotic bacteria showing differential abundance elicited in vitro by exposure to food components, including potential prebiotics (e.g., certain carbohydrates, and plant polyphenols). While adhesion of probiotic bacteria influenced by various environmental factors relevant to the gastrointestinal tract has been measured previously, this was rarely correlated with changes in the bacterial proteome induced by dietary nutrients. The present mini-review deals with effects of selected emerging prebiotics, food components and ingredients on the adhesion of probiotic lactobacilli to mucin and gut epithelial cells and concomitant abundancy changes of specific bacterial proteins. Applying this in vitro synbiotics-like approach enabled identification of moonlighting and other surface-located proteins of Lactobacillus acidophilus NCFM that are possibly associated with the adhesive mechanism.
Trends towards Biomimicry in Theranostics
Authors: Evangelopoulos Michael , Parodi Alessandro , Martinez Jonathan O. , Tasciotti Ennio
Published: August 2018

Over the years, imaging and therapeutic modalities have seen considerable progress as a result of advances in nanotechnology. Theranostics, or the marrying of diagnostics and therapy, has increasingly been employing nano-based approaches to treat cancer. While first-generation nanoparticles offered considerable promise in the imaging and treatment of cancer, toxicity and non-specific distribution hindered their true potential. More recently, multistage nanovectors have been strategically designed to shield and carry a payload to its intended site. However, detection by the immune system and sequestration by filtration organs (i.e., liver and spleen) remains a major obstacle. In an effort to circumvent these biological barriers, recent trends have taken inspiration from biology. These bioinspired approaches often involve the use of biologically-derived cellular components in the design and fabrication of biomimetic nanoparticles. In this review, we provide insight into early nanoparticles and how they have steadily evolved to include bioinspired approaches to increase their theranostic potential.
A Natural Dietary Supplement with a Combination of Nutrients Prevents Neurodegeneration Induced by a High Fat Diet in Mice
Authors: Nuzzo Domenico , Amato Antonella , Picone Pasquale , Terzo Simona , Galizzi Giacoma , Bonina Francesco Paolo , Mulè Flavia , Di Carlo Marta
Published: August 2018

Obesity and metabolic disorders can be risk factors for the onset and development of neurodegenerative diseases. The aim of the present study was to investigate the protective effects of a natural dietary supplement (NDS), containing Curcuma longa, silymarin, guggul, chlorogenic acid and inulin, on dysmetabolism and neurodegeneration in the brains of high fat diet (HFD)-fed mice. Decrease in the expression of FACL-4, CerS-1, CerS-4, cholesterol concentration and increase in the insulin receptor expression and insulin signaling activation, were found in brains of NDS-treated HFD brains in comparison with HFD untreated-mice, suggesting that NDS is able to prevent brain lipid accumulation and central insulin resistance. In the brains of NDS-treated HFD mice, the levels of RNS, ROS and lipid peroxidation, the expression of p-ERK, H-Oxy, i-NOS, HSP60, NF-kB, GFAP, IL-1β, IL-6 and CD4 positive cell infiltration were lower than in untreated HFD mice, suggesting antioxidant and anti-inflammatory effects of NDS. The decreased expression of p-ERK and GFAP in NDS-treated HFD mice was confirmed by immunofluorescence. Lastly, a lower number of apoptotic nuclei was found in cortical sections of NDS-treated HFD mice. The present data indicate that NDS exerts neuroprotective effects in HFD mice by reducing brain fat accumulation, oxidative stress and inflammation and improving brain insulin resistance.
Dietary Melatonin Supplementation Could Be a Promising Preventing/Therapeutic Approach for a Variety of Liver Diseases
Authors: Bonomini Francesca , Borsani Elisa , Favero Gaia , Rodella Luigi F. , Rezzani Rita
Published: August 2018

In the therapeutic strategies, the role of diet is a well-established factor that can also have an important role in liver diseases. Melatonin, identified in animals, has many antioxidant properties and it was after discovered also in plants, named phytomelatonin. These substances have a positive effect during aging and in pathological conditions too. In particular, it is important to underline that the amount of melatonin produced by pineal gland in human decreases during lifetime and its reduction in blood could be related to pathological conditions in which mitochondria and oxidative stress play a pivotal role. Moreover, it has been indicated that melatonin/phytomelatonin containing foods may provide dietary melatonin, so their ingestion through balanced diets could be sufficient to confer health benefits. In this review, the classification of liver diseases and an overview of the most important aspects of melatonin/phytomelatonin, concerning the differences among their synthesis, their presence in foods and their role in health and diseases, are summarized. The findings suggest that melatonin/phytomelatonin supplementation with diet should be considered important in preventing different disease settings, in particular in liver. Currently, more studies are needed to strengthen the potential beneficial effects of melatonin/phytomelatonin in liver diseases and to better clarify the molecular mechanisms of action.
Inhibitory Effect of Astaxanthin on Oxidative Stress-Induced Mitochondrial Dysfunction-A Mini-Review
Authors: Kim Suhn Hyung , Kim Hyeyoung
Published: August 2018

Oxidative stress is a major contributor to the pathogenesis of various human diseases as well as to the aging process. Mitochondria, as the center of cellular metabolism and major regulators of redox balance, play a critical role in disease development and progression. Mitochondrial dysfunction involving structural and metabolic impairment is prominent in oxidative stress-related diseases. Increased oxidative stress can damage mitochondria, and subsequent mitochondrial dysfunction generates excesses of mitochondrial reactive oxygen species that cause cellular damage. Mitochondrial dysfunction also activates the mitochondrial apoptotic pathway, resulting in cellular death. Astaxanthin, a red-colored xanthophyll carotenoid, exerts an anti-oxidative and anti-inflammatory effect on various cell lines. In this manner astaxanthin maintains mitochondrial integrity under various pathological conditions. In this review, the inhibitory effects of astaxanthin on oxidative stress-induced mitochondrial dysfunction and related disease development are discussed.
Layer-Structured Design and Fabrication of Cyanate Ester Nanocomposites for Excellent Electromagnetic Shielding with Absorption-Dominated Characteristic
Authors: Ren Fang , Guo Zheng-Zheng , Guo Han , Jia Li-Chuan , Zhao Yu-Chen , Ren Peng-Gang , Yan Ding-Xiang
Published: August 2018

In this work, we propose novel layer-structured polymer composites (PCs) for manipulating the electromagnetic (EM) wave transport, which holds unique electromagnetic interference (EMI) shielding features. The as-prepared PCs with a multilayered structure exhibits significant improvement in overall EMI shielding effectiveness (EMI SE) by adjusting the contents and distribution of electrical and magnetic loss fillers. The layer-structured PCs with low nanofiller content (5 wt % graphene nanosheets (GNSs) and 15 wt % Fe3O4) and a thickness of only 2 mm exhibited ultrahigh electrical conductivity and excellent EMI SE, reaching up to 2000 S/m and 45.7 dB in the X-band, respectively. The increased EMI SE of the layer-structured PCs was mainly based on the improved absorption rather than the reflection of electromagnetic waves, which was attributed to the “absorb-reflect-reabsorb” process for the incident electromagnetic waves. This work may provide a simple and effective approach to achieve new EMI shielding materials, especially for absorption-dominated EMI shielding.
HIRS Outgoing Longwave Radiation—Daily Climate Data Record: Application toward Identifying Tropical Subseasonal Variability
Authors: Schreck Carl J. , Lee Hai-Tien , Knapp Kenneth R.
Published: August 2018

This study describes the development of a new globally gridded climate data record (CDR) for daily outgoing longwave radiation (OLR) using the High-Resolution Infrared Radiation Sounder (HIRS) sensor. The new product, hereafter referred to as HIRS OLR, has several differences and advantages over the widely-used daily OLR dataset derived from the Advanced Very High-Resolution Radiometer (AVHRR) sensor on the same NOAA Polar Operational Environmental Satellites (POES), hereafter AVHRR OLR. As a CDR, HIRS OLR has been intersatellite-calibrated to provide the most homogeneous record possible. AVHRR OLR only used the daytime and nighttime overpasses from a single satellite at a time, which creates some challenges for resolving the large diurnal cycle of OLR. HIRS OLR leverages all available overpasses and then calibrates geostationary estimates of OLR to represent that cycle more faithfully. HIRS also has more spectral channels, including those for measuring water vapor, which provides a more accurate measure of OLR. This difference is particularly relevant for large-scale convective systems such as the El Niño–Southern Oscillation and the Madden–Julian Oscillation, whereby the HIRS OLR can better identify the subtropical variability between the tropical convection and the extratropical teleconnections.