bluuebunny/crossref_metadata_2025 huggingface dataset:
PC Implementation of a Real-Time Simulator Using ATP Foreign Models and a Sound Card
Authors: Espinoza Renzo G. Fabián , Molina Yuri , Tavares Maria
Published: August 2018

This work reports the personal computer implementation of a real-time simulator based on the widely used Electromagnetic Transients Program, version Alternative Transients Program (EMTP-ATP) software for testing protection and control devices. The proposed simulator was implemented on a conventional PC with a GNU/Linux operative system including a real-time kernel. Using foreign models programmed in C, ATP was recompiled with the PortAudio (sound card I/O library) with tools for writing and reading the parallel port. In this way, the sound card was used as a digital-to-analog converter to generate voltage waveform outputs at each simulation time step of the ATP, and the parallel port was used for digital inputs and outputs, resulting in a real-time simulator that can interact with protection and control devices by means of hardware-in-the-loop tests. This work uses the minimum possible hardware requirements to try to implement a real-time simulator. Due to the limitation of two channels, this simulator was used mainly to demonstrate the implementation methodology concept at this stage; this concept could potentially be expanded with more powerful hardware to improve its performance. The performance of the implemented simulator was analyzed through interactions with a real intelligent electronic device (IED). Furthermore, a comparison with the results obtained by means of the well-known real-time digital simulator (RTDS) was presented and discussed.
A Data-Driven Approach for Condition Monitoring of Wind Turbine Pitch Systems
Authors: Yang Cong , Qian Zheng , Pei Yan , Wei Lu
Published: August 2018

With the rapid development of wind energy, it is important to reduce operation and maintenance (O&M) costs of wind turbines (WTs), especially for a pitch system, which suffers the highest failure rate and downtime. This paper proposes a data-driven method for pitch- system condition monitoring (CM) by only using supervisory control and data acquisition (SCADA) data without any faults, which could be applied to reduce O&M costs of pitch system by providing fault alarms. The pitch-motor temperature is selected as the indicator, and three feature-selection algorithms are employed to select the most appropriate input parameters for modeling. Six data-driven algorithms are applied to model pitch-motor temperature and the support vector regression (SVR) model has the highest accuracy. The control-chart method based on the residual errors between model output and measured value is utilized to calculate the outliers, thus the abnormal condition could be clearly identified once the outliers appear for a period of time. The effectiveness of the proposed method is demonstrated by several case studies, and compared with the classification models. Due to the adaptive ability and low cost, the proposed approach is suitable for online CM of pitch systems, and provides a strategy for CM of new WTs.
Ecological Factors Affecting White Pine, Red Oak, Bitternut Hickory and Black Walnut Underplanting Success in a Northern Temperate Post-Agricultural Forest
Authors: Truax Benoit , Gagnon Daniel , Fortier Julien , Lambert France , Pétrin Marc-Antoine
Published: August 2018

This study took place in southern Québec (Canada) where young stands of white ash and grey birch have been underplanted with white pine, red oak, bitternut hickory and black walnut. The establishment success of white pine and red oak was measured with and without tree shelters (to protect from deer). Ecological factors affecting the height growth of the four species were also measured for protected trees. After 6 years, the survival and total height of unprotected oak was 29% and 44.3 cm vs. 80.5% and 138.5 cm for protected oak. White pine was less affected by browsing (survival of 79.5 and 93.5%; height of 138.5 and 217.9 cm for unprotected vs. protected pine). Height of white pine was higher in the grey birch stands, while height of all hardwoods was higher in the white ash stands, which had better soil drainage, higher fertility, and an understory dominated by Rubus species. Total height of all hardwoods was significantly (p < 0.05) correlated with Rubus cover and with soil fertility. Pine and walnut height were strongly correlated (p < 0.001) to shelterwood structure (canopy openness or total basal area). Pine was less sensitive to variations in shelterwood characteristics, while black walnut showed high sensitivity. This study provides evidence that underplanting is suitable for black walnut assisted migration northward and for bitternut hickory restoration, despite soil conditions that were less favorable than in bottomland habitats mainly supporting these species in eastern Canada. Tree shelters offering protection from deer browsing and species-specific site selection are recommended for underplanting in the southern Québec region.
Taylor’s Power Law for Leaf Bilateral Symmetry
Authors: Wang Ping , Ratkowsky David A. , Xiao Xiao , Yu Xiaojing , Su Jialu , Zhang Lifang , Shi Peijian
Published: August 2018

Leaf shape and symmetry is of interest because of the importance of leaves in photosynthesis. Recently, a novel method was proposed to measure the extent of bilateral symmetry in leaves in which a leaf was divided into left and right sides by a straight line through the leaf apex and base, and a number of equidistant strips were drawn perpendicular to the straight line to generate an equivalent number of differences in area between the left and right parts. These areal differences are the basis for a measure of leaf bilateral symmetry, which was then examined to see how well it follows Taylor’s power law (TPL) using three classes of plants, namely, 10 geographical populations of Parrotia subaequalis (H.T. Chang) R.M. Hao et H.T. Wei, 10 species of Bambusoideae, and 10 species of Rosaceae. The measure of bilateral symmetry followed TPL for a single species or for a class of closely related species. The estimate of the exponent of TPL for bamboo plants was significantly larger than for the dicotyledonous trees, but its goodness of fit was the best among the three classes of plants. The heterogeneity of light falling on branches and leaves due to above-ground architectural patterns is an important contributor to leaf asymmetry.
Genome-Wide Quantification of the Effect of Gene Overexpression on Escherichia coli Growth
Authors: Chen Hao , Venkat Sumana , Wilson Jessica , McGuire Paige , Chang Abigail L. , Gan Qinglei , Fan Chenguang
Published: August 2018

Recombinant protein production plays an essential role in both biological studies and pharmaceutical production. Escherichia coli is one of the most favorable hosts for this purpose. Although a number of strategies for optimizing protein production have been developed, the effect of gene overexpression on host cell growth has been much less studied. Here, we performed high-throughput tests on the E. coli a complete set of E. coli K-12 ORF archive (ASKA) collection to quantify the effects of overexpressing individual E. coli genes on its growth. The results indicated that overexpressing membrane-associated proteins or proteins with high abundances of branched-chain amino acids tended to impair cell growth, the latter of which could be remedied by amino acid supplementation. Through this study, we expect to provide an index for a fast pre-study estimate of host cell growth in order to choose proper rescuing approaches when working with different proteins.
Protect Your Sleep When Work is Calling: How Work-Related Smartphone Use During Non-Work Time and Sleep Quality Impact Next-Day Self-Control Processes at Work
Authors: Gombert Lilian , Konze Anne-Kathrin , Rivkin Wladislaw , Schmidt Klaus-Helmut
Published: August 2018

In view of the rapid development of information and communication technologies, the present study sheds light on how work-related smartphone use during non-work time affects employees’ subsequent working day. Specifically, we examine work-related smartphone use and sleep quality as moderators of next-day self-control processes at work. Theorizing that work-related smartphone use and self-control demands deplete a common limited regulatory resource, we suggest a strengthening two-way interaction between work-related smartphone use during non-work time and next-day self-control demands at work in predicting employees’ ego depletion at work. Moreover, in a three-way interaction, we analyze whether this interaction depends on employees’ sleep quality, assuming that when intensive work-related smartphone use is followed by high-quality sleep, the taxed regulatory resource can replenish overnight. Results from our diary study covering 10 working days (n = 63) indicate that after evenings with high work-related smartphone use, employees experience disproportionate levels of ego depletion when dealing with self-control demands at work. Sleep quality, however, attenuates this interaction. In cases of high sleep quality, next-day self-control processes at work are no longer affected by work-related smartphone use. Based on these findings, we discuss implications for employees and employers regarding work-related smartphone use and the relevance of sleep in replenishing drained resources.
Migration and Fate of Acid Mine Drainage Pollutants in Calcareous Soil
Authors: Liu Fenwu , Qiao Xingxing , Zhou Lixiang , Zhang Jian
Published: August 2018

As a major province of mineral resources in China, Shanxi currently has 6000 mines of various types, and acid mine drainage (AMD) is a major pollutant from the mining industry. Calcareous soil is dominant in western North China (including the Shanxi Province), therefore, clarifying the migration behavior of the main AMD pollutants (H+, S, Fe, heavy metals) in calcareous soil is essential for remediating AMD-contaminated soil in North China. In this study, the migration behavior of the main pollutants from AMD in calcareous soil was investigated using soil columns containing 20 cm of surficial soil to which different volumes of simulated AMD were added in 20 applications. Filtrate that was discharged from the soil columns and the soil samples from the columns were analyzed. Almost all of the Fe ions (>99%) from the AMD were intercepted in the 0–20 cm depth of the soil. Although >80% of SO42− was retained, the retention efficiency of the soil for SO42− was lower than it was for Fe. Cu, as a representative of heavy metals that are contained in AMD, was nearly totally retained by the calcareous soil. However, Cu had a tendency to migrate downward with the gradual acidification of the upper soil. In addition, CaCO3 was transformed into CaSO4 in AMD-contaminated soil. The outcomes of this study are valuable for understanding the pollution of calcareous soil by AMD and can provide key parameters for remediating AMD-contaminated soil.
Drivers Analysis of CO2 Emissions from the Perspective of Carbon Density: The Case of Shandong Province, China
Authors: Dong Feng , Li Jingyun , Zhang Yue-Jun , Wang Ying
Published: August 2018

Against the backgrounds of emission reduction targets promised by China, it is crucial to explore drivers of CO2 emissions comprehensively for policy making. In this study, Shandong Province in China is taken as an example to investigate drivers in carbon density by using an extended Kaya identity and a logarithmic mean Divisia index model (LMDI) with two layers. It is concluded that there are eight positive driving factors of carbon density during 2000–2015, including traffic congestion, land urbanization, etc., and seven negative driving factors comprising energy intensity, economic structure, etc. Among these factors, economic growth and energy intensity are the main positive and negative driving factor, respectively. The contribution rate of traffic congestion and land urbanization is gradually increasing. Meanwhile, 15 driving factors are divided into five categories. Economic effect and urbanization effect are the primary positive drivers. Contrarily, energy intensity effect, structural effect, and scale effect contribute negative effects to the changes in carbon density. In the four stages, the contribution of urbanization to carbon density is inverted U. Overall, the results and suggestions can give support to decision maker to draw up relevant government policy.
Methylmercury in Industrial Harbor Sediments in Taiwan: First Observations on Its Occurrence, Distribution, and Measurement
Authors: Chen Chih-Feng , Ju Yun-Ru , Lin Guan-Ting , Chen Chiu-Wen , Dong Cheng-Di
Published: August 2018

The distribution of methylmercury (MeHg) and total mercury (T-Hg) in sediments of the estuaries and the basin in Kaohsiung Harbor (Taiwan) is studied. MeHg in the sediment samples was determined using gas chromatography-mass spectrometry. The certified reference material of sediments with respect to the method showed the recovery efficiency between 97.4 and 103.6% which confirmed the applicability of analysis method. The T-Hg and MeHg concentrations were between 149 to 9035 μg/kg and <0.31 to 17.7 μg/kg, respectively. The T-Hg and MeHg concentrations in the estuaries of Kaohsiung Harbor were relatively high. Results suggest that Hg in this studied area was likely contributed from the catchments of the rivers. The MeHg level was <0.01 to 2.66% of the T-Hg in the sediments. A positive correlation is obtained between MeHg, T-Hg, and total organic carbon in the sediments, whereas a negative correlation is observed between pH, oxidation-reduction potential, and MeHg concentration. The results further suggest that sediment characteristics contribute mainly to the distribution of MeHg.
Correction: Dawson, T.; et al. A Spatial Analysis of the Relationship between Vegetation and Poverty. Int. J. Geo-Inf. 2018, 7, 83
Authors: Dawson Teddy , Sandoval J. S. Onésimo , Sagan Vasit , Crawford Thomas
Published: August 2018

The authors wish to make the following corrections to their paper[...]
Two New Polyphenol Oxidase Genes of Tea Plant (Camellia sinensis) Respond Differentially to the Regurgitant of Tea Geometrid, Ectropis obliqua
Authors: Huang Chen , Zhang Jin , Zhang Xin , Yu Yongchen , Bian Wenbo , Zeng Zhongping , Sun Xiaoling , Li Xinghui
Published: August 2018

Polyphenol oxidases (PPOs) have been reported to play an important role in protecting plants from attacks by herbivores. Though PPO genes in other plants have been extensively studied, research on PPO genes in the tea plant (Camellia sinensis) is lacking. In particular, which members of the PPO gene family elicit the defense response of the tea plant are as yet unknown. Here, two new PPO genes, CsPPO1 and CsPPO2, both of which had high identity with PPOs from other plants, were obtained from tea leaves. The full length of CsPPO1 contained an open reading frame (ORF) of 1740 bp that encoded a protein of 579 amino acids, while CsPPO2 contained an ORF of 1788 bp that encoded a protein of 595 amino acids. The deduced CsPPO1 and CsPPO2 proteins had calculated molecular masses of 64.6 and 65.9 kDa; the isoelectric points were 6.94 and 6.48, respectively. The expression products of recombinant CsPPO1 and CsPPO2 in Escherichia coli were about 91 and 92 kDa, respectively, but the recombinant proteins existed in the form of an inclusion body. Whereas CsPPO1 is highly expressed in stems, CsPPO2 is highly expressed in roots. Further results showed that the expression of CsPPO1 and CsPPO2 was wound- and Ectropis obliqua-induced, and that regurgitant, unlike treatment with wounding plus deionized water, significantly upregulated the transcriptional expression of CsPPO2 but not of CsPPO1. The difference between regurgitant and wounding indicates that CsPPO2 may play a more meaningful defensive role against E. obliqua than CsPPO1. Meanwhile, we found the active component(s) of the regurgitant elicited the expression of CsPPO may contain small molecules (under 3-kDa molecular weight). These conclusions advance the understanding of the biological function of two new PPO genes and show that one of these, CsPPO2, may be a promising gene for engineering tea plants that are resistant to E. obliqua.
Long-Term Effects of Cold on Growth, Development and Yield of Narrow-Leaf Lupine May Be Alleviated by Seed Hydropriming or Butenolide
Authors: Płażek Agnieszka , Dubert Franciszek , Kopeć Przemysław , Dziurka Michał , Kalandyk Agnieszka , Pastuszak Jakub , Waligórski Piotr , Wolko Bogdan
Published: August 2018

In this article, the effects of cold on the development of Lupine angustifolius and the possibility of mitigating it, via seed hydropriming or pre-treatment with butenolide (10−6 M–10−4 M), are investigated in two cultivars, differing in their ability to germinate at low temperature. Physiological background of plant development after cold stress was investigated in imbibed seeds. For the first four weeks, the seedlings grew at 7 °C or 13 °C. Seeds well germinating at 7 °C demonstrated higher activity of α-amylase and higher levels of gibberellins, IAA and kinetin. Germination ability at low temperature correlated with dehydrogenase activity and membrane permeability. Seed pre-treatment improved germination at low temperature by decreasing abscisic acid content. Seed hydropriming alleviated cold effects on plant development rate and yield, while butenolide accelerated vegetative development but delayed the generative phase. Potential seed yield may be predicted based on the seed germination vigour and the photosynthetic efficiency measured before flowering.
Enhancement of Radiation Effectiveness in Cervical Cancer Cells by Combining Ionizing Radiation with Hyperthermia and Molecular Targeting Agents
Authors: IJff Marloes , Van Oorschot Bregje , Oei Arlene L. , Krawczyk Przemek M. , Rodermond Hans M. , Stalpers Lukas J. A. , Kok H. Petra , Crezee Johannes , Franken Nicolaas A. P.
Published: August 2018

Hyperthermia (HT) and molecular targeting agents can be used to enhance the effect of radiotherapy (RT). The purpose of this paper is to evaluate radiation sensitization by HT and different molecular targeting agents (Poly [ADP-ribose] polymerase 1 inhibitor, PARP1-i; DNA-dependent protein kinase catalytic subunit inhibitor, DNA-PKcs-i and Heat Shock Protein 90 inhibitor, HSP90-i) in cervical cancer cell lines. Survival curves of SiHa and HeLa cells, concerning the combined effects of radiation with hyperthermia and PARP1-i, DNA-PKcs-i or HSP90-i, were analyzed using the linear-quadratic model: S(D)/S(0) = exp − (αD + βD2). The values of the linear-quadratic (LQ) parameters α and β, determine the effectiveness at low and high doses, respectively. The effects of these sensitizing agents on the LQ parameters are compared to evaluate dose-dependent differences in radio enhancement. Combination of radiation with hyperthermia, PARP1-i and DNA-PKcs-i significantly increased the value of the linear parameter α. Both α and β were significantly increased for HSP90-i combined with hyperthermia in HeLa cells, though not in SiHa cells. The Homologous Recombination pathway is inhibited by hyperthermia. When hyperthermia is combined with DNA-PKcs-i and PARP1-i, the Non-Homologous End Joining or Alternative Non-Homologous End Joining pathway is also inhibited, leading to a more potent radio enhancement. The observed increments of the α value imply that significant radio enhancement is obtained at clinically-used radiotherapy doses. Furthermore, the sensitizing effects of hyperthermia can be even further enhanced when combined with other molecular targeting agents.
Emerging Roles of Sonic Hedgehog in Adult Neurological Diseases: Neurogenesis and Beyond
Authors: Chen Shang-Der , Yang Jenq-Lin , Hwang Wei-Chao , Yang Ding-I
Published: August 2018

Sonic hedgehog (Shh), a member of the hedgehog (Hh) family, was originally recognized as a morphogen possessing critical characters for neural development during embryogenesis. Recently, however, Shh has emerged as an important modulator in adult neural tissues through different mechanisms such as neurogenesis, anti-oxidation, anti-inflammation, and autophagy. Therefore, Shh may potentially have clinical application in neurodegenerative diseases and brain injuries. In this article, we present some examples, including ours, to show different aspects of Shh signaling and how Shh agonists or mimetics are used to alter the neuronal fates in various disease models, both in vitro and in vivo. Other potential mechanisms that are discussed include alteration of mitochondrial function and anti-aging effect; both are critical for age-related neurodegenerative diseases. A thorough understanding of the protective mechanisms elicited by Shh may provide a rationale to design innovative therapeutic regimens for various neurodegenerative diseases.
Mitochondrial DNA Haplogroup JT is Related to Impaired Glycaemic Control and Renal Function in Type 2 Diabetic Patients
Authors: Diaz-Morales Noelia , Lopez-Domenech Sandra , Iannantuoni Francesca , Lopez-Gallardo Ester , Sola Eva , Morillas Carlos , Rocha Milagros , Ruiz-Pesini Eduardo , Victor Victor M.
Published: August 2018

The association between mitochondrial DNA (mtDNA) haplogroup and risk of type 2 diabetes (T2D) is undetermined and controversial. This study aims to evaluate the impact of the main mtDNA haplogroups on glycaemic control and renal function in a Spanish population of 303 T2D patients and 153 healthy controls. Anthropometrical and metabolic parameters were assessed and mtDNA haplogroup was determined in each individual. Distribution of the different haplogroups was similar in diabetic and healthy populations and, as expected, T2D patients showed poorer glycaemic control and renal function than controls. T2D patients belonging to the JT haplogroup (polymorphism m.4216T>C) displayed statistically significant higher levels of fasting glucose and HbA1c than those of the other haplogroups, suggesting a poorer glycaemic control. Furthermore, diabetic patients with the JT haplogroup showed a worse kidney function than those with other haplogroups, evident by higher levels of serum creatinine, lower estimated glomerular filtration rate (eGFR), and slightly higher (although not statistically significant) urinary albumin-to-creatinine ratio. Our results suggest that JT haplogroup (in particular, change at position 4216 of the mtDNA) is associated with poorer glycaemic control in T2D, which can trigger the development of diabetic nephropathy.
Analysis of Favorable Process Conditions for the Manufacturing of Thin-Wall Pieces of Mild Steel Obtained by Wire and Arc Additive Manufacturing (WAAM)
Authors: Prado-Cerqueira José Luis , Camacho Ana María , Diéguez José Luis , Rodríguez-Prieto Álvaro , Aragón Ana María , Lorenzo-Martín Cinta , Yanguas-Gil Ángel
Published: August 2018

One of the challenges in additive manufacturing (AM) of metallic materials is to obtain workpieces free of defects with excellent physical, mechanical, and metallurgical properties. In wire and arc additive manufacturing (WAAM) the influences of process conditions on thermal history, microstructure and resultant mechanical and surface properties of parts must be analyzed. In this work, 3D metallic parts of mild steel wire (American Welding Society-AWS ER70S-6) are built with a WAAM process by depositing layers of material on a substrate of a S235 JR steel sheet of 3 mm thickness under different process conditions, using as welding process the gas metal arc welding (GMAW) with cold metal transfer (CMT) technology, combined with a positioning system such as a computer numerical controlled (CNC) milling machine. Considering the hardness profiles, the estimated ultimate tensile strengths (UTS) derived from the hardness measurements and the microstructure findings, it can be concluded that the most favorable process conditions are the ones provided by CMT, with homogeneous hardness profiles, good mechanical strengths in accordance to conditions defined by standard, and without formation of a decohesionated external layer; CMT Continuous is the optimal option as the mechanical properties are better than single CMT.
Mechanical Properties Study of Fe-Mn-Si Shape Memory Alloys Welding Seam Formed by Laser Welding with Filler Powder
Authors: Ju Heng , Lin Chengxin , Tian Yun , Liu Zhijie , Jiang Huiling , Sun Deping
Published: August 2018

To reduce the residual stress and improve the fatigue property of the laser weldment by using the stress self-accommodation characteristic of Fe-Mn-Si shape memory alloys (SMAs), a Fe15Mn5Si12Cr6Ni memory alloy welding seam was formed inside 304 stainless steel by laser welding with filler powder. The combination of the hole-drilling method and the ANSYS software was used to research the distribution law of residual stress inside the laser welding specimen. The fatigue strength of the laser welded specimens with the Fe-Mn-Si SMAs welding seam (experimental materials) and 304 stainless steel welding seam (comparative materials) was measured by cycle bending fatigue test. The microhardness of the welding specimens was measured by the microhardness tester. The thermodynamic model of the laser welding process and the phase transition crystallography of Fe-Mn-Si SMAs were evaluated to analyze the strengthening mechanism of the mechanical properties in the experimental materials. The results show that the distribution law for residual stress in the experiment and simulation are consistent. The experimental materials possess low residual stress, high fatigue strength and high microhardness. The strengthening mechanism for mechanical properties is the welding residual stress-induced γ→ε martensitic transformation inside the experimental materials, which causes the tensile plastic strain of the welding seam to resist residual compression strain, and the residual stress, as the transition driving force, is released in shear processing.
Sol-Gel Synthesis of Silicon-Doped Lithium Manganese Oxide with Enhanced Reversible Capacity and Cycling Stability
Authors: Zhao Hongyuan , Li Dongdong , Wang Yashuang , Li Fang , Wang Guifang , Wu Tingting , Wang Zhankui , Li Yongfeng , Su Jianxiu
Published: August 2018

A series of silicon-doped lithium manganese oxides were obtained via a sol-gel process. XRD characterization results indicate that the silicon-doped samples retain the spinel structure of LiMn2O4. Electrochemical tests show that introducing silicon ions into the spinel structure can have a great effect on reversible capacity and cycling stability. When cycled at 0.5 C, the optimal Si-doped LiMn2O4 can exhibit a pretty high initial capacity of 140.8 mAh g−1 with excellent retention of 91.1% after 100 cycles, which is higher than that of the LiMn2O4, LiMn1.975Si0.025O4, and LiMn1.925Si0.075O4 samples. Moreover, the optimal Si-doped LiMn2O4 can exhibit 88.3 mAh g−1 with satisfactory cycling performance at 10 C. These satisfactory results are mainly contributed by the more regular and increased MnO6 octahedra and even size distribution in the silicon-doped samples obtained by sol-gel technology.
Effects of Loading Frequency and Loading Type on High-Cycle and Very-High-Cycle Fatigue of a High-Strength Steel
Authors: Hu Yuanpei , Sun Chengqi , Xie Jijia , Hong Youshi
Published: August 2018

High-cycle and very-high-cycle fatigue tests via rotary bending (52.5 Hz), electromagnetic resonance (120 Hz) axial cycling, and ultrasonic (20 kHz) axial cycling were performed for a high-strength steel with three heat treatment conditions, and the effects of loading frequency and loading type on fatigue strength and fatigue life were investigated. The results revealed that the loading frequency effect is caused by the combined response of strain rate increase and induced temperature rise. A parameter η was proposed to judge the occurrence of loading frequency effect, and the calculated results were in agreement with the experimental data. In addition, a statistical method based on the control volume was used to reconcile the effect of loading type, and the predicted data were consistent with the experimental results.
Photosynthetic Accumulation of Lutein in Auxenochlorella protothecoides after Heterotrophic Growth
Authors: Xiao Yibo , He Xi , Ma Qi , Lu Yue , Bai Fan , Dai Junbiao , Wu Qingyu
Published: August 2018

In order to enhance lutein accumulation and to explain the reasons for the difference in lutein accumulation under photoautotrophic and heterotrophic conditions, different culture modes and the associated transcriptome profiles were investigated in Auxenochlorella protothecoides. The heterotrophic-photoautotrophic transition culture mode was investigated for lutein accumulation, changing from organic carbon to increase biomass in dark fermentation to irradiation under nitrogen rich conditions. This strategy increased the lutein content 10 times along with chloroplast regeneration and little biomass loss in 48 h. The highest lutein productivity and production in the heterotrophic-photoautotrophic transition culture reached 12.36 mg/L/day and 34.13 mg/L respectively within seven days. Furthermore, compared to the photoautotrophic conditions, most genes involved in lutein biosynthesis and photosystem generation were down-regulated during heterotrophic growth. By contrast, two β-ring hydroxylases were transiently upregulated, while violaxanthin de-epoxidase and zeaxanthin epoxidase were mostly downregulated, which explained the extremely low lutein content of heterotrophic cells. Nevertheless, the lutein proportion in total carotenoids reached nearly 100%. This study is the first to our knowledge to report on a comparative transcriptome analysis of lutein biosynthesis, and it provides a promising strategy to boost lutein production in A. protothecoides.
Microstructure, Solidification Texture, and Thermal Stability of 316 L Stainless Steel Manufactured by Laser Powder Bed Fusion
Authors: Krakhmalev Pavel , Fredriksson Gunnel , Svensson Krister , Yadroitsev Igor , Yadroitsava Ina , Thuvander Mattias , Peng Ru
Published: August 2018

This article overviews the scientific results of the microstructural features observed in 316 L stainless steel manufactured by the laser powder bed fusion (LPBF) method obtained by the authors, and discusses the results with respect to the recently published literature. Microscopic features of the LPBF microstructure, i.e., epitaxial nucleation, cellular structure, microsegregation, porosity, competitive colony growth, and solidification texture, were experimentally studied by scanning and transmission electron microscopy, diffraction methods, and atom probe tomography. The influence of laser power and laser scanning speed on the microstructure was discussed in the perspective of governing the microstructure by controlling the process parameters. It was shown that the three-dimensional (3D) zig-zag solidification texture observed in the LPBF 316 L was related to the laser scanning strategy. The thermal stability of the microstructure was investigated under isothermal annealing conditions. It was shown that the cells formed at solidification started to disappear at about 800 °C, and that this process leads to a substantial decrease in hardness. Colony boundaries, nevertheless, were quite stable, and no significant grain growth was observed after heat treatment at 1050 °C. The observed experimental results are discussed with respect to the fundamental knowledge of the solidification processes, and compared with the existing literature data.
Characterization of Deformation Mechanisms in Mg Alloys by Advanced Acoustic Emission Methods
Authors: Čapek Jan , Knapek Michal , Minárik Peter , Dittrich Jan , Máthis Kristián
Published: August 2018

Adaptive sequential k-means (ASK) analysis of acoustic emission (AE) data was used to analyze the sources of AE during compression of three AZ31 magnesium samples with different initial texture. The results were compared to the classical hit-based approach. Observation of the deformed microstructure shows that the ASK analysis can distinguish very well between the signal originating in deformation twinning and dislocation slip. Moreover, together with microstructural analysis, the ASK algorithm revealed another source of AE for one of the samples, which was shown to be the double twinning.
Interfacial Characterization and Bonding Properties of Copper/Aluminum Clad Sheets Processed by Horizontal Twin-Roll Casting, Multi-Pass Rolling, and Annealing
Authors: Mao Zhiping , Xie Jingpei , Wang Aiqin , Wang Wenyan , Ma Douqin
Published: August 2018

The copper/aluminum (Cu/Al) clad sheets were produced on a horizontal twin-roll caster and then were multi-pass rolled and annealed. The thickness of the as-cast clad sheet was 8 mm. Rolling was performed with total reductions of 12.5%, 25%, 37.5%, 50%, and 62.5%, separately. The effects of the rolling and annealing processes on the interface and peel strength of the Cu/Al clad sheets were investigated. The evolution of the interface and crack propagation were studied. The interface thickness of the as-cast clad sheet reached 9 μm to 10 μm. The average peel strength (APS) was only 9 N/mm. After multi-pass rolling, the peel strength first slightly increased and then gradually decreased with the increase of the rolling pass number. After annealing, the peel strength remarkably improved. The APS reached 25 N/mm when the rolled thickness was 7 mm. The improvement in the peel strength was due to the following three factors: (1) mechanical locking formed in the Cu/Al direct contact region after rolling, (2) the region of the Al matrix fracture, and (3) mechanical biting from the Cu/Al direct contact region.
Alkali Vapor MEMS Cells Technology toward High-Vacuum Self-Pumping MEMS Cell for Atomic Spectroscopy
Authors: Knapkiewicz Pawel
Published: August 2018

The high-vacuum self-pumping MEMS cell for atomic spectroscopy presented here is the result of the technological achievements of the author and the research group in which he works. A high-temperature anodic bonding process in vacuum or buffer gas atmosphere and the influence of the process on the inner gas composition inside a MEMS structure were studied. A laser-induced alkali vapor introduction method from solid-state pill-like dispenser is presented as well. The technologies mentioned above are groundbreaking achievements that have allowed the building of the first European miniature atomic clock, and they are the basis for other solutions, including high-vacuum optical MEMS. Following description of the key technologies, high-vacuum self-pumping MEMS cell construction and preliminary measurement results are reported. This unique solution makes it possible to achieve a 10−6 Torr vacuum level inside the cell in the presence of saturated rubidium vapor, paving the way to building a new class of optical reference cells for atomic spectroscopy. Because the level of vacuum is high enough, experiments with cold atoms are potentially feasible.
A Review of Flotation Separation of Mg Carbonates (Dolomite and Magnesite)
Authors: Wonyen Darius G. , Kromah Varney , Gibson Borbor , Nah Solomon , Chelgani Saeed Chehreh
Published: August 2018

It is well documented that flotation has high economic viability for the beneficiation of valuable minerals when their main ore bodies contain magnesium (Mg) carbonates such as dolomite and magnesite. Flotation separation of Mg carbonates from their associated valuable minerals (AVMs) presents several challenges, and Mg carbonates have high levels of adverse effects on separation efficiency. These complexities can be attributed to various reasons: Mg carbonates are naturally hydrophilic, soluble, and exhibit similar surface characteristics as their AVMs. This study presents a compilation of various parameters, including zeta potential, pH, particle size, reagents (collectors, depressant, and modifiers), and bio-flotation, which were examined in several investigations into separating Mg carbonates from their AVMs by froth flotation.
Rutacecarpine Inhibits Angiogenesis by Targeting the VEGFR2 and VEGFR2-Mediated Akt/mTOR/p70s6k Signaling Pathway
Authors: Ji Lijun , Wu Mingfei , Li Zeng
Published: August 2018

This study aimed to investigate the effect of Ru (Rut) on angiogenesis, and the underlying regulation mechanism of signal transduction. 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay, adhesion inhibition experiment, migration inhibition experiment, and chick embryo chorioallantoic membrane (CAM) assays were performed on models of angiogenesis. The potential targets of rutaecarpine (Ru) were reverse screened with Discovery Studio 2017. The interaction between the compound and target were detected by surface plasmon resonance (SPR), enzyme-activity experiment, and Western blot assay. The obtained results confirmed that Ru exhibited modest inhibitory activity against human umbilical vein endothelial cells (HUVECs) (IC50 =16.54 ± 2.4 μM) and remarkable inhibitive effect against the migration and adhesion of HUVECs, as well as significant anti-angiogenesis activities in the CAM assay. The possible targets of vascular endothelial growth factor receptor 2 (VEGFR2) were identified by computer-aided simulation. Results showed a good binding relationship between the ligand and target through molecular docking, and this relationship was confirmed by SPR analysis. Furthermore, enzyme-activity experiment and western blot assay showed that Ru remarkably inhibited the activity of VEGFR2 and blocked the VEGFR2-mediated Akt/ (mTOR)/p70s6k signaling pathway in vitro. Ru can be a potential drug candidate for cancer prevention and cancer therapy.
Characterization of Nanospheres Containing Zanthoxylum riedelianum Fruit Essential Oil and Their Insecticidal and Deterrent Activities against Bemisia tabaci (Hemiptera: Aleyrodidae)
Authors: Pereira Karla de Castro , Quintela Eliane Dias , Da Silva Daniel José , Do Nascimento Vinicius Alves , Da Rocha Dannilo V. M. , Silva José Francisco Arruda e , Forim Moacir Rossi , Silva Fabiano Guimarães , Cazal Cristiane de Melo
Published: August 2018

The aim of our study was to produce and characterize poly-ε-caprolactone (PCL) nanospheres containing essential oils from Zanthoxylum riedelianum fruit and to evaluate their stability gains as well as their insecticidal and deterrent activities against whitefly (Bemisia tabaci). The PCL nanospheres exhibited a homogeneous spherical morphology, with particle diameters between 106.7 nm and 129.2 nm, pH of approximately 6, zeta potential (ZP) lower than −19.0 mV and encapsulation efficiency higher than 98%. Only 43% of the nanoencapsulated essential oil (NSEO) was degraded in response to ultraviolet light, whereas the essential oil (EO) degraded by 76% over the same period. In a free-choice test, the NSEO and EO reduced the number of whitefly eggs by approximately 70%. NSEO and EO at 1.5% killed 82.87% and 91.23% of 2nd-instar nymphs of whitefly, respectively. Although NSEO displayed lower insecticidal activity, it offers a greater advantage over the free EO, due to protection conferred by polymer against photodegradation. Therefore, its usage may optimize the maintenance of essential oils in the field through photoprotection and controlled release. Our results suggest that the EO of Z. riedelianum fruit can be used for B. tabaci management strategy; nevertheless, the benefits of NSEO require further evaluation at the field level.
Synstable Fusion: A Network-Based Algorithm for Estimating Driver Genes in Fusion Structures
Authors: Xu Mingzhe , Zhao Zhongmeng , Zhang Xuanping , Gao Aiqing , Wu Shuyan , Wang Jiayin
Published: August 2018

Gene fusion structure is a class of common somatic mutational events in cancer genomes, which are often formed by chromosomal mutations. Identifying the driver gene(s) in a fusion structure is important for many downstream analyses and it contributes to clinical practices. Existing computational approaches have prioritized the importance of oncogenes by incorporating prior knowledge from gene networks. However, different methods sometimes suffer different weaknesses when handling gene fusion data due to multiple issues such as fusion gene representation, network integration, and the effectiveness of the evaluation algorithms. In this paper, Synstable Fusion (SYN), an algorithm for computationally evaluating the fusion genes, is proposed. This algorithm uses network-based strategy by incorporating gene networks as prior information, but estimates the driver genes according to the destructiveness hypothesis. This hypothesis balances the two popular evaluation strategies in the existing studies, thereby providing more comprehensive results. A machine learning framework is introduced to integrate multiple networks and further solve the conflicting results from different networks. In addition, a synchronous stability model is established to reduce the computational complexity of the evaluation algorithm. To evaluate the proposed algorithm, we conduct a series of experiments on both artificial and real datasets. The results demonstrate that the proposed algorithm performs well on different configurations and is robust when altering the internal parameter settings.
A Simple Mannose-Coated Poly (p-Phenylene Ethynylene) for Qualitative Bacterial Capturing
Authors: Tsakama Madalitso , Ma Xiaochi , He Yonghuan , Chen Weihua , Dai Xiaofeng
Published: August 2018

A mannose-functionalized poly (p-phenylene ethynylene) was rationally designed to achieve selective detection of bacteria. The polymer was constructed as a signaling unit and was modified by attaching aminoethyl mannose using the carboxylic acid group at the end of the linker. Incubation of Escherichia coli with the polymer yielded fluorescent bacteria aggregates through polyvalent interactions. The utility of the mannose functionalized polymer to detect E. coli expressing functional FimH mannose-specific lectin on their surface was also demonstrated. The sugar units displayed on the surface of the polymer retained their functional ability to interact with mannose-binding lectin. To determine the optimum binding time, we measured the fluorescence intensity of the polymer-bacteria suspension at intervals. Our results showed that binding in this system will reach an optimum level within 30 min of incubation. The polymer’s affinity for bacteria has been demonstrated and bacteria with a concentration of 103 CFU mL−1 can be detected by this system.
Hepatoprotective Effects of MHY3200 on High-Fat, Diet-Induced, Non-Alcoholic Fatty Liver Disease in Rats
Authors: Kim Min Jo , Park Chan Hum , Kim Dae Hyun , Park Min Hi , Park Kyung Chul , Hyun Min Kyung , Lee A Kyoung , Moon Hyung Ryong , Chung Hae Young
Published: August 2018

This study investigated the effects of 2-(4-(5-chlorobenzo[d]thiazol-2-yl)phenoxy)-2,2-difluoroacetic acid (MHY3200) on high-fat diet (HFD)-induced hepatic lipid accumulation and inflammation. The measurement of peroxisome proliferator-activated receptor (PPAR)α activity by using a luciferase assay indicated that MHY3200 was more potent than a known PPARα agonist, WY14643, in AC2F cells. Six-month-old male SD rats were fed chow or HFD for 1 month, and after, with or without added MHY3200 (1 or 2 mg/kg/day) for 4 weeks. The oral administration of MHY3200 caused a significant decrease in serum triglyceride (TG), glucose, alanine aminotransferase, and insulin, as well as a slight decrease in the level of free fatty acid and aspartate transaminase. No weight gain was detected when compared with HFD rats, and hepatic TG content was also attenuated by the administration of MHY3200. Furthermore, phosphorylation of the ER stress marker, inositol-requiring kinase 1 and its downstream gene, c-Jun N-terminal kinase, in addition to serine phosphorylation of insulin receptor substrate 1 were suppressed by MHY3200. Consistent with these results, MHY3200 administration reduced the levels of activation of protein-1, cyclooxygenase-2, and inducible nitric oxide synthase. Our results suggested that MHY3200 ameliorated HFD-induced hepatic lipid accumulation and inflammation, and improved insulin resistance through PPARα activation.
The Effect of Alkyl Chain Number in Sucrose Surfactant on the Physical Properties of Quercetin-Loaded Deformable Nanoliposome and Its Effect on In Vitro Human Skin Penetration
Authors: Hong In Ki , Ha Ji Hoon , Han Sangkeun , Kang Hakhee , Park Soo Nam
Published: August 2018

Non-invasive skin penetration of a drug is increased by an edge activator, which enhances the nanoliposome deformability. The objective of this study was to investigate the role of the alkyl chain number of sucrose surfactants as an edge activator in elastic nanoliposomes. In addition, the physicochemical properties of the elastic nanoliposomes were characterized and an in vitro human skin permeation study was performed. Elastic nanoliposomes that were composed of sucrose monostearate (MELQ), sucrose distearate (DELQ), and sucrose tristearte (TELQ) were prepared using a thin-film hydration method. Particle size and entrapment efficiency of elastic nanoliposomes increased proportionally with an increase in the amounts and the numbers of the stearate in sucrose surfactant. Deformability of elastic nanoliposomes was indicated as DELQ > MELQ > TELQ and the same pattern was revealed through the in vitro human skin permeability tests. These results suggest that the number of alkyl chains of sucrose surfactant as edge activator affects the physicochemical property, stability, and skin permeability in elastic nanoliposome. Our findings give a valuable platform for the development of elastic nanoliposomes as skin drug delivery systems.
Cognitive Functioning of Geriatric Patients: Is Hypovitaminosis D the Next Marker of Cognitive Dysfunction and Dementia?
Authors: Łukaszyk Ewelina , Bień-Barkowska Katarzyna , Bień Barbara
Published: August 2018

The study objective is to investigate whether vitamin D is associated with the cognitive function of geriatric patients. This cross-sectional study involved 357 patients hospitalized in the geriatric ward who complained of memory problems (mean age: 82.3 years). The level of cognitive function was measured with the Mini-Mental State Examination (MMSE) and the clinical diagnosis of dementia was established according to the International Classification of Diseases (ICD-10) criteria. The serum 25-hydroxy vitamin D was measured with liquid chromatography-tandem mass spectrometry. The iterative Bayesian model averaging (BMA) procedure was applied to linear and logistic regression models in order to identify the best set of factors describing cognitive dysfunction and dementia, respectively. According to BMA, there is strong evidence that higher vitamin D levels, higher body mass index (BMI), and higher mobility function measured with the Timed Up and Go (TUG) test are independently associated with better cognitive performance and lower risk of dementia. Additionally, there is strong evidence that fewer years of education and lower vitamin B12 plasma levels independently describe worse cognitive performance. However, vitamin B12 levels higher than 800 pg/mL is negatively associated with the MMSE performance. Hypovitaminosis D in geriatric patients is an underrated marker of cognitive dysfunction and dementia.