bluuebunny/crossref_metadata_2025 huggingface dataset:
Class-3 Semaphorins and Their Receptors: Potent Multifunctional Modulators of Tumor Progression
Authors: Toledano Shira , Nir-Zvi Inbal , Engelman Rotem , Kessler Ofra , Neufeld Gera
Published: January 2019

Semaphorins are the products of a large gene family containing 28 genes of which 21 are found in vertebrates. Class-3 semaphorins constitute a subfamily of seven vertebrate semaphorins which differ from the other vertebrate semaphorins in that they are the only secreted semaphorins and are distinguished from other semaphorins by the presence of a basic domain at their C termini. Class-3 semaphorins were initially characterized as axon guidance factors, but have subsequently been found to regulate immune responses, angiogenesis, lymphangiogenesis, and a variety of additional physiological and developmental functions. Most class-3 semaphorins transduce their signals by binding to receptors belonging to the neuropilin family which subsequently associate with receptors of the plexin family to form functional class-3 semaphorin receptors. Recent evidence suggests that class-3 semaphorins also fulfill important regulatory roles in multiple forms of cancer. Several class-3 semaphorins function as endogenous inhibitors of tumor angiogenesis. Others were found to inhibit tumor metastasis by inhibition of tumor lymphangiogenesis, by direct effects on the behavior of tumor cells, or by modulation of immune responses. Notably, some semaphorins such as sema3C and sema3E have also been found to potentiate tumor progression using various mechanisms. This review focuses on the roles of the different class-3 semaphorins in tumor progression.
Dynamic Protein S-Acylation in Plants
Authors: Zheng Lihua , Liu Peng , Liu Qianwen , Wang Tao , Dong Jiangli
Published: January 2019

Lipid modification is an important post-translational modification. S-acylation is unique among lipid modifications, as it is reversible and has thus attracted much attention. We summarize some proteins that have been shown experimentally to be S-acylated in plants. Two of these S-acylated proteins have been matched to the S-acyl transferase. More importantly, the first protein thioesterase with de-S-acylation activity has been identified in plants. This review shows that S-acylation is important for a variety of different functions in plants and that there are many unexplored aspects of S-acylation in plants.
Proteomic Analysis of the Resistance Mechanisms in Sugarcane during Sporisorium scitamineum Infection
Authors: Singh Pratiksha , Song Qi-Qi , Singh Rajesh Kumar , Li Hai-Bi , Solanki Manoj Kumar , Malviya Mukesh Kumar , Verma Krishan Kumar , Yang Li-Tao , Li Yang-Rui
Published: January 2019

Smut disease is caused by Sporisorium scitamineum, an important sugarcane fungal pathogen causing an extensive loss in yield and sugar quality. The available literature suggests that there are two types of smut resistance mechanisms: external resistance by physical or chemical barriers and intrinsic internal resistance mechanisms operating at host–pathogen interaction at cellular and molecular levels. The nature of smut resistance mechanisms, however, remains largely unknown. The present study investigated the changes in proteome occurring in two sugarcane varieties with contrasting susceptibility to smut—F134 and NCo310—at whip development stage after S. scitamineum infection. Total proteins from pathogen inoculated and uninoculated (control) leaves were separated by two-dimensional gel electrophoresis (2D-PAGE). Protein identification was performed using BLASTp and tBLASTn against NCBI nonredundant protein databases and EST databases, respectively. A total of thirty proteins spots representing differentially expressed proteins (DEPs), 16 from F134 and 14 from NCo310, were identified and analyzed by MALDI-TOF/TOF MS. In F134, 4 DEPs were upregulated and nine were downregulated, while, nine were upregulated and three were downregulated in NCo310. The DEPs were associated with DNA binding, metabolic processes, defense, stress response, photorespiration, protein refolding, chloroplast, nucleus and plasma membrane. Finally, the expression of CAT, SOD, and PAL with recognized roles in S. scitamineum infection in both sugarcane verities were analyzed by real-time quantitative PCR (RT-qPCR) technique. Identification of genes critical for smut resistance in sugarcane will increase our knowledge of S. scitamineum-sugarcane interaction and help to develop molecular and conventional breeding strategies for variety improvement.
Transcriptional Analysis of Immunohistochemically Defined Subgroups of Non-Muscle-Invasive Papillary High-Grade Upper Tract Urothelial Carcinoma
Authors: Jung Minsun , Lee Jeong Hoon , Kim Bohyun , Park Jeong Hwan , Moon Kyung Chul
Published: January 2019

Immunohistochemical (IHC) staining for CK5/6 and CK20 was reported to be correlated with the prognosis of early urothelial carcinoma in a way contrary to that of advanced tumors for unknown reasons. We aimed to characterize the gene expression profiles of subgroups of non-muscle-invasive papillary high-grade upper tract urothelial carcinoma (UTUC) classified by CK5/6 and CK20 expression levels: group 1 (CK5/6-high/CK20-low), group 2 (CK5/6-high/CK20-high), and group 3 (CK5/6-low/CK20-high). Expression of group 3 was predictive of worse prognosis of non-muscle-invasive papillary high-grade UTUC. Transcriptional analysis revealed 308 differentially expressed genes across the subgroups. Functional analyses of the genes identified cell adhesion as a common process differentially enriched in group 3 compared to the other groups, which could explain its high-risk phenotype. Late cell cycle/proliferation signatures were also enriched in group 3 and in some of the other groups, which may be used as a prognostic biomarker complementary to CK5/6 and CK20. Group 2, characterized by low levels of genes associated with mitogen-activated protein kinase and tumor necrosis factor signaling pathways, was hypothesized to represent the least cancerous subtype considering its normal urothelium-like IHC pattern. This study would facilitate the application of easily accessible prognostic biomarkers in practice.
Dual Roles of Astrocyte-Derived Factors in Regulation of Blood-Brain Barrier Function after Brain Damage
Authors: Michinaga Shotaro , Koyama Yutaka
Published: January 2019

The blood-brain barrier (BBB) is a major functional barrier in the central nervous system (CNS), and inhibits the extravasation of intravascular contents and transports various essential nutrients between the blood and the brain. After brain damage by traumatic brain injury, cerebral ischemia and several other CNS disorders, the functions of the BBB are disrupted, resulting in severe secondary damage including brain edema and inflammatory injury. Therefore, BBB protection and recovery are considered novel therapeutic strategies for reducing brain damage. Emerging evidence suggests key roles of astrocyte-derived factors in BBB disruption and recovery after brain damage. The astrocyte-derived vascular permeability factors include vascular endothelial growth factors, matrix metalloproteinases, nitric oxide, glutamate and endothelin-1, which enhance BBB permeability leading to BBB disruption. By contrast, the astrocyte-derived protective factors include angiopoietin-1, sonic hedgehog, glial-derived neurotrophic factor, retinoic acid and insulin-like growth factor-1 and apolipoprotein E which attenuate BBB permeability resulting in recovery of BBB function. In this review, the roles of these astrocyte-derived factors in BBB function are summarized, and their significance as therapeutic targets for BBB protection and recovery after brain damage are discussed.
Candidate Gene Selection for Cytoplasmic Male Sterility in Pepper (Capsicum annuum L.) through Whole Mitochondrial Genome Sequencing
Authors: Wang Peng , Lu Qiaohua , Ai Yixin , Wang Yihao , Li Tiantian , Wu Lang , Liu Jinqiu , Cheng Qing , Sun Liang , Shen Huolin
Published: January 2019

Cytoplasmic male sterility (CMS), which is controlled by mitochondrial genes, is an important trait for commercial hybrid seed production. So far, genes controlling this trait are still not clear in pepper. In this study, complete mitochondrial genomes were sequenced and assembled for the CMS line 138A and its maintainer line 138B. The genome size of 138A is 504,210 bp, which is 8618 bp shorter than that of 138B. Meanwhile, more than 214 and 215 open reading frames longer than 100 amino acids (aas) were identified in 138A and 138B, respectively. Mitochondrial genome structure of 138A was quite different from that of 138B, indicating the existence of recombination and rearrangement events. Based on the mitochondrial genome sequence and structure variations, mitochondrion of 138A and FS4401, a Korean origin CMS line, may have inherited from a common female ancestor, but their CMS traits did originate separately. Candidate gene selection was performed according to the published characteristics of the CMS genes, including the presence SNPs and InDels, located in unique regions, their chimeric structure, co-transcription, and transmembrane domain. A total of 35 ORFs were considered as potential candidate genes and 14 of these were selected, with orf300a and 0rf314a as strong candidates. A new marker, orf300a, was developed which did co-segregate with the CMS trait.
Hypolipogenic Effect of Shikimic Acid Via Inhibition of MID1IP1 and Phosphorylation of AMPK/ACC
Authors: Kim Moon Joon , Sim Deok Yong , Lee Hye Min , Lee Hyo-Jung , Kim Sung-Hoon
Published: January 2019

Although shikimic acid from Illicium verum has antioxidant, antibacterial, anti-inflammatory, and analgesic effects, the effect of shikimic acid on lipogenesis has not yet been explored. Thus, in the present study, hypolipogenic mechanism of shikimic acid was examined in HepG2, Huh7 and 3T3-L1 adipocyte cells. Shikimic acid showed weak cytotoxicity in HepG2, Huh7 and 3T3-L1 cells, but suppressed lipid accumulation in HepG2, Huh7 and 3T3-L1 cells by Oil Red O staining. Also, shikimic acid attenuated the mRNA expression of de novo lipogenesis related genes such as FAS, SREBP-1c, and LXR-α in HepG2 cells by RT-PCR analysis and suppressed the protein expression of SREBP-1c and LXR-α in HepG2 and 3T3-L1 cells. It should be noted that shikimic acid activated phosphorylation of AMP-activated protein kinase (AMPK)/Aacetyl-coenzyme A carboxylase (ACC) and reduced the expression of MID1 Interacting Protein 1 (MID1IP1) in HepG2, Huh7 and 3T3-L1 cells. Conversely, depletion of MID1IP1 activated phosphorylation of AMPK, while overexpression of MID1IP1 suppressed phosphorylation of AMPK in HepG2 cells. However, AMPK inhibitor compound c did not affect the expression of MID1IP1, indicating MID1IP1 as an upstream of AMPK. Taken together, our findings suggest that shikimic acid has hypolipogenic effect in HepG2 and 3T3-L1 cells via phosphorylation of AMPK/ACC and inhibition of MID1IP1 as a potent candidate for prevention or treatment of fatty liver and hyperlipidemia.
Efficient Security Scheme for Disaster Surveillance UAV Communication Networks
Authors: Abdallah Asmaa , Ali M. Zulfiker , Mišić Jelena , Mišić Vojislav B.
Published: January 2019

The Unmanned Aerial Vehicles (UAVs) play a significant role to alleviate the negative impacts of disasters by providing essential assistance to the rescue and evacuation operations in the affected areas. Then, the reliability of UAV connections and the accuracy of exchanged information are critical parameters. In this paper, we propose networking and security architecture for disaster surveillance UAV system. The networking scheme involves a two-tier cluster network based on IEEE 802.11ah, which can provide traffic isolation between the tiers. The security scheme guarantees the accuracy and availability of the collected information from the disaster area applying fingerprint features and data redundancy techniques; the proposed scheme also utilizes the lightweight Ring-Learning with Errors (Ring-LWE) crypto-system to assure the confidentiality of the transmitted data with low overhead.
Fused Zinc Target for the Production of Gallium Radioisotopes
Authors: Zeisler Stefan , Limoges Alan , Kumlin Joel , Siikanen Jonathan , Hoehr Cornelia
Published: February 2019

Gallium-68 is a popular radioisotope for positron emission tomography. To make gallium-68 more accessible, we developed a new solid target for medical cyclotrons. Fused zinc targets promise a new, efficient, and reliable technique without the downsides of other commonly used time-consuming methods for solid target fabrication, such as electroplating and sputtering. We manufactured targets by fusing small pressed zinc pellets into a recess in aluminum backings. Using a simple hotplate, the fusing could be accomplished in less than two minutes. Subsequently, the targets were cooled, polished, and used successfully for test irradiations at Ep = 12.8 MeV and up to 20 µA proton current.
Effects of Reduced Graphene Oxide (rGO) at Different Concentrations on Tribological Properties of Liquid Base Lubricants
Authors: Patel Jankhan , Kiani Amirkianoosh
Published: January 2019

In this study, reduced graphene oxide (rGO) nano platelets were used as an additive to enhance friction and wear properties of oil-based lubricants by preparing three samples at 0.01% w/w, 0.05% w/w, and 0.1% w/w concentrations. To analyze the direct effect of rGO nano platelets on tribological properties, 99.9% pure oil was used as a liquid lubricant. A comparative tribological study was done by performing a ball-on-disk wear test in situ under harsh conditions, which was further analyzed using a non-contact 3D optical profilometer. Morphological evaluation of the scar was done using transmission and scanning electron microscopy (TEM, SEM) at micro and nano levels. The lubricants’ physical properties, such as viscosity and oxidation number, were evaluated and compared for all samples including pure oil (control sample) as per ASTM standards. Findings of all these tests show that adding rGO nano platelets at 0.05% w/w showed significant reduction in friction at high speed and in wear up to 51.85%, which is very promising for increasing the life span of moving surfaces in machinery. Oxidation and viscosity tests also proved that adding rGO nano platelets to all samples does not sacrifice the physical properties of the lubricant, while it improves friction and wear properties.
Crystallization Behavior of Al70Fe12.5V12.5Nb5 Amorphous Alloy Formed by Mechanical Alloying
Authors: Liu Xuan , Wang Xingfu , Si Yongli , Zhong Xiaokang , Han Fusheng
Published: January 2019

In this study, the formation and crystallization of the Al70Fe12.5V12.5Nb5 amorphous alloys has been investigated. The addition of Nb enhances the supercooled liquid region and glass forming ability of the Al-Fe-V amorphous alloys. The Al70Fe12.5V12.5Nb5 amorphous alloy exhibits two distinct crystallization steps and a large supercooled liquid region at more than 100 K. Kissinger and Ozawa analyses showed that the two activation energies for crystallization (Ex) were estimated to be 366.3 ± 23.9 and 380.5 ± 23.9 kJ/mol. Large supercooled liquid regions are expected to gain an application field of Al-based amorphous alloys.
Compression Strength Mechanisms of Low-Density Fibrous Materials
Authors: Ketoja Jukka A. , Paunonen Sara , Jetsu Petri , Pääkkönen Elina
Published: January 2019

In this work we challenge some earlier theoretical ideas on the strength of lightweight fiber materials by analyzing an extensive set of foam-formed fiber networks. The experimental samples included various different material densities and different types of natural and regenerated cellulose fibers. Characterization of the samples was performed by macroscopic mechanical testing, supported by simultaneous high-speed imaging of local deformations inside a fiber network. The imaging showed extremely heterogeneous deformation behavior inside a sample, with both rapidly proceeding deformation fronts and comparatively still regions. Moreover, image correlation analysis revealed frequent local fiber dislocations throughout the compression cycle, not only for low or moderate compressive strains. A new buckling theory including a statistical distribution of free-span lengths is proposed and tested against the experimental data. The theory predicts universal ratios between stresses at different compression levels for low-density random fiber networks. The mean ratio of stresses at 50% and 10% compression levels measured over 57 different trial points, 5.42 ± 0.43, agrees very well with the theoretical value of 5.374. Moreover, the model predicts well the effect of material density, and can be used in developing the properties of lightweight materials in novel applications.
Structural Controlling of Highly-Oriented Polycrystal 3C-SiC Bulks via Halide CVD
Authors: Hu Zhiying , Zheng Dingheng , Tu Rong , Yang Meijun , Li Qizhong , Han Mingxu , Zhang Song , Zhang Lianmeng , Goto Takashi
Published: January 2019

Highly-oriented polycrystal 3C-SiC bulks were ultra-fast fabricated via halide chemical vapor deposition (CVD) using tetrachlorosilane (SiCl4) and methane (CH4) as precursors. The effects of deposition temperature (Tdep) and total pressure (Ptot) on the orientation and surficial morphology were investigated. The results showed that the growth orientation of 3C-SiC columnar grains was strongly influenced by Tdep. With increasing Tdep, the columnar grains transformed from <111>- to <110>-oriented. The arrangement of <111>-oriented columnar grains was controlled by Ptot. Lotus-, turtle-, thorn-, and strawberry-like surface morphologies were naturally contributed by different arrangements of <111>-oriented grains, and the deposition mechanism was discussed. The wetting behaviors of CVD-SiC samples by molten aluminum were also examined at 1173 K in a high vacuum atmosphere.
Anodic Polarization Behavior of X80 Steel in Na2SO4 Solution under High Potential and Current Density Conditions
Authors: Qin Runzhi , Du Yanxia , Xu Zhenchang , Lu Minxu
Published: January 2019

X80 steel has great risk of corrosion in high voltage direct current (HVDC) interference cases. In this study, the anodic polarization behavior of X80 steel under high potential and current density in Na2SO4 solution was investigated. The I × R drop was eliminated using current interrupt technique during the potentiodynamic measurement. Therefore, the real polarization curve was obtained. The corrosion behavior was investigated by galvanostatic polarization, scanning electron microscopy, and X-ray photoelectron spectroscopy. The results show a new form of passivation route. The steel dissolved actively below −0.388 VSCE, then became partly passivated from −0.388 to 1.448 VSCE, and fully passivated above 1.448 VSCE. The passive film was formed containing Fe2O3 and FeOOH, and resistant to SO42− ions. It not only blocked the direct dissolution of steel, but also facilitated oxygen evolution. The corrosion rates of steel samples decreased after the passivation.
Magnetic Fe2O3–SiO2–MeO2–Pt (Me = Ti, Sn, Ce) as Catalysts for the Selective Hydrogenation of Cinnamaldehyde. Effect of the Nature of the Metal Oxide
Authors: Dinamarca Robinson , Espinoza-González Rodrigo , Campos Cristian H. , Pecchi Gina
Published: January 2019

The type of metal oxide affects the activity and selectivity of Fe2O3–SiO2–MeO2–Pt (Me = Ti, Sn, Ce) catalysts on the hydrogenation of cinnamaldehyde. The double shell structure design is thought to protect the magnetic Fe2O3 cores, and also act as a platform for depositing a second shell of TiO2, SnO2 or CeO2 metal oxide. To obtain a homogeneous metallic dispersion, the incorporation of 5 wt % of Pt was carried out over Fe2O3–SiO2–MeO2 (Me = Ti, Sn, Ce) structures modified with (3-aminopropyl)triethoxysilane by successive impregnation-reduction cycles. The full characterization by HR-TEM, STEM-EDX, XRD, N2 adsorption isotherm at −196 °C, TPR-H2 and VSM of the catalysts indicates that homogeneous core-shell structures with controlled nano-sized magnetic cores, multi-shells and metallic Pt were obtained. The nature of the metal oxide affects the Pt nanoparticle sizes where the mean Pt diameter is in the order: –TiO2–Pt > –SnO2–Pt > –CeO2–Pt. Among the catalysts studied, –CeO2–Pt had the best catalytic performance, reaching the maximum of conversion at 240 min. of reaction without producing hydrocinnamaldehyde (HCAL). It also showed a plot volcano type for the production of cinnamic alcohol (COL), with 3-phenyl-1-propanol (HCOL) as a main product. The –SnO2–Pt catalyst showed a poor catalytic performance attributable to the Pt clusters’ occlusion in the irregular surface of the –SnO2. Finally, the –TiO2–Pt catalyst showed a continuous production of COL with a 100% conversion and 65% selectivity at 600 min of reaction.
The Impact of MGMT Promoter Methylation and Temozolomide Treatment in Serbian Patients with Primary Glioblastoma
Authors: Jovanović Nikola , Mitrović Tatjana , Cvetković Vladimir J. , Tošić Svetlana , Vitorović Jelena , Stamenković Slaviša , Nikolov Vesna , Kostić Aleksandar , Vidović Nataša , Krstić Miljan , Jevtović-Stoimenov Tatjana , Pavlović Dušica
Published: February 2019

Background and objective: Despite recent advances in treatment, glioblastoma (GBM) remains the most lethal and aggressive brain tumor. A continuous search for a reliable molecular marker establishes the methylation status of the O6-methylguanine-DNA methyltransferase (MGMT) gene promoter as a key prognostic factor in primary glioblastoma. The aim of our study was to screen Serbian patients with primary glioblastoma for an MGMT promoter hypermethylation and to evaluate its associations with overall survival (OS) and sensitivity to temozolomide (TMZ) treatment. Materials and methods: A cohort of 30 Serbian primary glioblastoma patients treated with radiation therapy and chemotherapy were analyzed for MGMT promoter methylation and correlated with clinical data. Results: MGMT methylation status was determined in 25 out of 30 primary glioblastomas by methylation-specific PCR (MSP). MGMT promoter hypermethylation was detected in 12 out of 25 patients (48%). The level of MGMT promoter methylation did not correlate with patients’ gender (p = 0.409), age (p = 0.536), and OS (p = 0.394). Treatment with TMZ significantly prolonged the median survival of a patient (from 5 to 15 months; p < 0.001). Conclusions: Due to a small cohort of primary GBM patients, our study is not sufficient for definitive conclusions regarding the prognostic value of MGMT methylation for the Serbian population. Our preliminary data suggest a lack of association between MGMT promoter methylation and overall survival and a significant correlation of TMZ treatment with overall survival. Further population-based studies are needed to assess the prognostic value of the MGMT promoter methylation status for patients with primary glioblastoma.
Guggulsterone Activates Adipocyte Beiging through Direct Effects on 3T3-L1 Adipocytes and Indirect Effects Mediated through RAW264.7 Macrophages
Authors: Miller Colette N. , Samuels Janaiya S. , Azhar Yusra , Parmar Ashish , Shashidharamurthy Rangaiah , Rayalam Srujana
Published: February 2019

Background: Plant-derived phytochemicals have been of emerging interest as anti-obesity compounds due to their apparent effects on promoting reduced lipid accumulation in adipocytes. Despite such promising evidence, little is known about the potential mechanisms behind their anti-obesity effects. The aim of this study is to establish potential anti-obesity effects of the phytochemical guggulsterone (GS). Methods: Mature 3T3-L1 adipocytes were treated with GS, derived from the guggul plant native in northern India, to investigate its effects on mitochondrial biogenesis and adipocyte “beiging.” Further, to explore the relationship between macrophages and adipocytes, 3T3-L1s were treated with conditioned media from GS-treated RAW264.7 macrophages. Markers of mitochondrial biogenesis and beiging were measured by western blot. Results: GS treatment in adipocytes resulted in increased mitochondrial density, biogenesis (PGC1α and PPARγ), and increased markers of a beige adipocyte phenotype (UCP1, TBX1, and β-3AR). This upregulation in mitochondrial expression was accompanied by increases oxygen consumption. In GS-treated macrophages, markers of M2 polarization were elevated (e.g., arginase and IL-10), along with increased catecholamine release into the media. Lastly, 3T3-L1 adipocytes treated with conditioned media from macrophages induced a 167.8% increase in UCP1 expression, suggestive of a role of macrophages in eliciting an anti-adipogenic response to GS. Conclusions: Results from this study provide the first mechanistic understanding of the anti-obesity effects of GS and suggests a role for both direct GS-signaling and indirect stimulation of M2 macrophage polarization in this model.
Effect of Zr Addition on Overaging and Tensile Behavior of 2618 Aluminum Alloy
Authors: Toschi Stefania , Balducci Eleonora , Ceschini Lorella , Mørtsell Eva Anne , Morri Alessandro , Di Sabatino Marisa
Published: January 2019

The effect of Zr addition on overaging and tensile behavior in a 2618 Al–Cu–Mg–Ni–Fe alloy has been investigated in this study. The chemical composition of the base 2618 alloy, containing ~0.1 wt % of Zr, was modified by adding Zr to reach the target content of 0.25 wt %. Cast bars were T6 heat-treated according to industrial parameters, involving soaking at 525 °C for 8 h, quenching in hot water (50 °C), and artificial aging at 200 °C for 20 h. Both the T6 2618 and 2618 + Zr alloys were overaged at 250 and 300 °C for up to 192 h, to evaluate the decrease in hardness with high temperature exposure time. The tensile behavior of the alloys was investigated in the overaged condition, both at room temperature and at 250 °C. The microstructure of the as-cast and solution-treated samples was investigated by optical and scanning electron microscopy, while the precipitate microstructure at the nanoscale was analyzed by transmission electron microscopy in overaged condition. Experimental data revealed that the presence of 0.25 wt % Zr does not induce modifications at the macroscale on the microstructure of 2618 alloy while, at the nanoscale, the presence of Zr-based precipitates was observed. The overaged Zr-enriched alloy showed increased yield and ultimate tensile strength in comparison to the base alloy, at equal heat treatment condition, both at room temperature and 250 °C.
Numerical Simulation of Steel Reinforced Concrete (SRC) Joints
Authors: Montava Isaac , Irles Ramon , Segura Jorge , Gadea Jose Maria , Juliá Ernesto
Published: January 2019

This paper presents a three-dimensional finite element model to confirm experimental tests carried out on steel reinforced concrete joints. The nonlinear behavior of this concrete is simulated, along with its reduced capability to resist large displacements in compression. The aim was to obtain the plastic behavior of reinforced concrete beams with a numerical model in the same way as obtained experimentally, in which the reduction of strength in the post-critical stage was considered to simulate behavior until structures collapsed. To do this, a nonlinear calculation was necessary to simulate the behavior of each material. Three numerical models provide a moment–curvature graph of the cross-section until collapse. Simulation of the structural elements is a powerful tool that avoids having to carry out expensive experimental tests. From the experimental results a finite element model is simulated for the non-linear analysis of steel reinforced concrete joints. It is possible to simulate the decreasing stress behavior of the concrete until reaching considerable displacement. A new procedure is discussed to capture the moment-curvature diagram. This diagram can be used in a simplified frame analysis, considering post-critical behavior for future research.
VHCF Response of Two AISI H13 Steels: Effect of Manufacturing Process and Size-Effect
Authors: Tridello Andrea
Published: January 2019

In the last decades, the fatigue lifetime of structural components has increased significantly and in many industrial applications (aerospace, automotive, and energy production industry) is even larger than 1010 cycles. Therefore, the interest in the Very High Cycle Fatigue (VHCF) behavior of materials has grown rapidly, becoming a subject of primary interest among university and industries. In high-strength steels, VHCF failures generally originate from defects/inclusions; consequently, the steel cleanliness significantly affects the VHCF response. Furthermore, since the probability of finding critical defects in a loaded volume increases with the loaded volume, the loaded volume also significantly affects the VHCF response. This is generally referred to as the “size-effect” in VHCF. The present paper investigates the effects of the manufacturing process and the size-effect on the VHCF response of an AISI H13 steel. Experimental tests were performed on hourglass and Gaussian specimens made of two different types of AISI H13 steels: Unrefined H13 and refined Electroslag Remelting (ESR) H13. The analysis of variance (ANOVA), which was carried out on the test results, and the P–S–N curves showed that the two factors (i.e., the manufacturing process and the size-effect) significantly affect the VHCF response.
Effect of Substituting CaO with BaO and CaO/Al2O3 Ratio on the Viscosity of CaO–BaO–Al2O3–CaF2–Li2O Mold Flux System
Authors: Li Zhirong , You Xinchen , Li Min , Wang Qian , He Shengping , Wang Qiangqiang
Published: January 2019

The effect of substituting CaO with BaO and CaO/Al2O3 ratio on the viscosity of CaO–BaO–Al2O3–CaF2–Li2O mold flux system was studied by rotational viscosity method. The results showed that the viscosity increased with increasing BaO as a substitute for CaO, while the viscosity decreased with the increase in CaO/Al2O3 ratio. The viscous activation energy of the slags is from 92.1 kJ·mol−1 to 133.4 kJ·mol−1. Either the Arhenius or the Weymann–Frenkel equation can be applied to establish the viscosity prediction model. In this paper, the Weymann–Frenkel equation and a new optical basicity with regard to Al2O3 as an acidic oxide were applied to the modified NPL model for predicting the viscosity of CaO–BaO–Al2O3–CaF2–Li2O mold flux system. The estimated viscosity is in good agreement with the measured viscosity.
NMR Metabolomic Analysis of Skeletal Muscle, Heart, and Liver of Hatchling Loggerhead Sea Turtles (Caretta caretta) Experimentally Exposed to Crude Oil and/or Corexit
Authors: Bembenek-Bailey Stasia A. , Niemuth Jennifer N. , McClellan-Green Patricia D. , Godfrey Matthew H. , Harms Craig A. , Gracz Hanna , Stoskopf Michael K.
Published: January 2019

We used nuclear magnetic spectroscopy (NMR) to evaluate the metabolic impacts of crude oil, Corexit 5900A, a dispersant, and a crude oil Corexit 5900A mixture exposure on skeletal muscle, heart, and liver physiology of hatchling loggerhead sea turtles (Caretta caretta). Tissue samples were obtained from 22 seven-day-old hatchlings after a four day cutaneous exposure to environmentally relevant concentrations of crude oil, Corexit 5900A, a combination of crude oil and Corexit 9500A, or a seawater control. We identified 38 metabolites in the aqueous extracts of the liver, and 30 metabolites in both the skeletal and heart muscle aqueous extracts, including organic acids/osmolytes, energy compounds, amino acids, ketone bodies, nucleosides, and nucleotides. Skeletal muscle lactate, creatines, and taurine concentrations were significantly lower in hatchlings exposed to crude oil than in control hatchlings. Lactate, taurine, and cholines appeared to be the basis of some variation in hatchling heart samples, and liver inosine, uracil, and uridine appeared to be influenced by Corexit and crude oil exposure. Observed decreases in concentrations of lactate and creatines may reflect energy depletion in skeletal muscle of oil-exposed animals, while decreased taurine concentrations in these animals may reflect higher oxidative stress.
Metabolic Modeling of Human Gut Microbiota on a Genome Scale: An Overview
Authors: Sen Partho , Orešič Matej
Published: January 2019

There is growing interest in the metabolic interplay between the gut microbiome and host metabolism. Taxonomic and functional profiling of the gut microbiome by next-generation sequencing (NGS) has unveiled substantial richness and diversity. However, the mechanisms underlying interactions between diet, gut microbiome and host metabolism are still poorly understood. Genome-scale metabolic modeling (GSMM) is an emerging approach that has been increasingly applied to infer diet–microbiome, microbe–microbe and host–microbe interactions under physiological conditions. GSMM can, for example, be applied to estimate the metabolic capabilities of microbes in the gut. Here, we discuss how meta-omics datasets such as shotgun metagenomics, can be processed and integrated to develop large-scale, condition-specific, personalized microbiota models in healthy and disease states. Furthermore, we summarize various tools and resources available for metagenomic data processing and GSMM, highlighting the experimental approaches needed to validate the model predictions.
A Breakdown Enhanced AlGaN/GaN Schottky Barrier Diode with the T-Anode Position Deep into the Bottom Buffer Layer
Authors: Sun Youlei , Wang Ying , Tang Jianxiang , Wang Wenju , Huang Yifei , Kuang Xiaofei
Published: January 2019

In this paper, an AlGaN/GaN Schottky barrier diode (SBD) with the T-anode located deep into the bottom buffer layer in combination with field plates (TAI-BBF FPs SBD) is proposed. The electrical characteristics of the proposed structure and the conventional AlGaN/GaN SBD with gated edge termination (GET SBD) were simulated and compared using a Technology Computer Aided Design (TCAD) tool. The results proved that the breakdown voltage (VBK) in the proposed structure was tremendously improved when compared to the GET SBD. This enhancement is attributed to the suppression of the anode tunneling current by the T-anode and the redistribution of the electric field in the anode–cathode region induced by the field plates (FPs). Moreover, the T-anode had a negligible effect on the two-dimensional electron gas (2DEG) in the channel layer, so there is no deterioration in the forward characteristics. After being optimized, the proposed structure exhibited a low turn-on voltage (VT) of 0.53 V and a specific on-resistance (RON,sp) of 0.32 mΩ·cm2, which was similar to the GET SBD. Meanwhile, the TAI-BBF FP SBD with an anode-cathode spacing of 5 μm achieved a VBK of 1252 V, which was enhanced almost six times compared to the GET SBD with a VBK of 213 V.
Simulation and Validation of Droplet Generation Process for Revealing Three Design Constraints in Electrohydrodynamic Jet Printing
Authors: Pan Yanqiao , Zeng Liangcai
Published: January 2019

Droplet generation process can directly affect process regulation and output performance of electrohydrodynamic jet (E-jet) printing in fabricating micro-to-nano scale functional structures. This paper proposes a numerical simulation model for whole process of droplet generation of E-jet printing based on the Taylor-Melcher leaky-dielectric model. The whole process of droplet generation is successfully simulated in one whole cycle, including Taylor cone generation, jet onset, jet break, and jet retraction. The feasibility and accuracy of the numerical simulation model is validated by a 30G stainless nozzle with inner diameter ~160 μm by E-jet printing experiments. Comparing numerical simulations and experimental results, period, velocity magnitude, four steps in an injection cycle, and shape of jet in each step are in good agreement. Further simulations are performed to reveal three design constraints against applied voltage, flow rate, and nozzle diameter, respectively. The established cone-jet numerical simulation model paves the way to investigate influences of process parameters and guide design of printheads for E-jet printing system with high performance in the future.
Editorial for the Special Issue on Nanogenerators in Korea
Authors: Park Yong Tae , Choi Dukhyun
Published: January 2019

Nanogenerator-based technologies have found outstanding accomplishments in energy harvesting applications over the past two decades [...]
Rheological Issues in Carbon-Based Inks for Additive Manufacturing
Authors: O’ Mahony Charlie , Haq Ehtsham Ul , Silien Christophe , Tofail Syed A. M.
Published: January 2019

As the industry and commercial market move towards the optimization of printing and additive manufacturing, it becomes important to understand how to obtain the most from the materials while maintaining the ability to print complex geometries effectively. Combining such a manufacturing method with advanced carbon materials, such as Graphene, Carbon Nanotubes, and Carbon fibers, with their mechanical and conductive properties, delivers a cutting-edge combination of low-cost conductive products. Through the process of printing the effectiveness of these properties decreases. Thorough optimization is required to determine the idealized ink functional and flow properties to ensure maximum printability and functionalities offered by carbon nanoforms. The optimization of these properties then is limited by the printability. By determining the physical properties of printability and flow properties of the inks, calculated compromises can be made for the ink design. In this review we have discussed the connection between the rheology of carbon-based inks and the methodologies for maintaining the maximum pristine carbon material properties.
The Main Anorthosite Layer of the West-Pana Intrusion, Kola Region: Geology and U-Pb Age Dating
Authors: Groshev Nikolay Y. , Karykowski Bartosz T.
Published: January 2019

The West-Pana intrusion belongs to the Paleoproterozoic Fedorova-Pana Complex of the Kola Region in NW Russia, which represents one of Europe’s most significant layered complexes in terms of total platinum group element (PGE) endowment. Numerous studies on the age of the West-Pana intrusion have been carried out in the past; however, all published U-Pb isotope ages were determined using multi-grain ID-TIMS. In this study, the mineralized Main Anorthosite Layer from the upper portion of the intrusion was dated using SHRIMP-II for the first time. High Th/U (0.9–3.7) zircons gave an upper intercept age of 2509.4 ± 6.2 Ma (2σ), whereas the lower portion of the intrusion was previously dated at 2501.5 ± 1.7 Ma, which suggests an out-of-sequence emplacement of the West-Pana intrusion. Furthermore, high-grade PGE mineralization hosted by the anorthosite layer, known as “South Reef”, can be attributed to (1) downward percolation of PGE-enriched sulfide liquid from the overlying gabbronoritic magma or (2) secondary redistribution of PGEs, which may coincide with a post-magmatic alteration event recorded by low Th/U (0.1–0.9) zircon and baddeleyite at 2476 ± 13 Ma (upper intercept).
Electrical Conductivity of Fluorite and Fluorine Conduction
Authors: Liu Hanyong , Zhu Qiao , Yang Xiaozhi
Published: January 2019

Fluorine is a species commonly present in many minerals in the Earth’s interior, with a concentration ranging from a few ppm to more than 10 wt. %. Recent experimental studies on fluorine-bearing silicate minerals have proposed that fluorine might be an important charge carrier for electrical conduction of Earth materials at elevated conditions, but the results are somewhat ambiguous. In this investigation, the electrical conductivity of gem-quality natural single crystal fluorite, a simple bi-elemental (Ca and F) mineral, has been determined at 1 GPa and 200–650 °C in two replication runs, by a Solartron-1260 Impedance/Gain Phase analyzer in an end-loaded piston-cylinder apparatus. The sample composition remained unchanged after the runs. The conductivity data are reproducible between different runs and between heating-cooling cycles of each run. The conductivity (σ) increases with increasing temperature, and can be described by the Arrhenius law, σ = 10^(5.34 ± 0.07)·exp[−(130 ± 1, kJ/mol)/(RT)], where R is the gas constant and T is the temperature. According to the equation, the conductivity reaches ~0.01 S/m at 650 °C. This elevated conductivity is strong evidence that fluorine is important in charge transport. The simple construction of this mineral indicates that the electrical conduction is dominated by fluoride (F−). Therefore, fluorine is potentially an important charge carrier in influencing the electrical property of Fluorine-bearing Earth materials.
Responses of Acidithiobacillus thiooxidans A01 to Individual and Joint Nickel (Ni2+) and Ferric (Fe3+)
Authors: Chen Aijia , Hao Xiaodong , Xiao Yunhua , Zou Kai , Liu Hongwei , Liu Xueduan , Yin Huaqun , Qiu Guanzhou , Liang Yili
Published: January 2019

Acidithiobacillus thiooxidans A01 is widely used in bioleaching processes and commonly thrives in most metal-rich environments. However, interactions between different heavy metals remain obscure. In this study, we elaborated the effect of ferric iron on the growth and gene expression of At. thiooxidans A01 under the stress of nickel. The results showed that 600 mM Ni2+ completely inhibited the growth and sulfur metabolism of At. thiooxidans A01. However, trace amounts of Fe3+ (0.5 mM) facilitated the growth of At. thiooxidans A01 in the presence of 600 mM Ni2+. With the addition of 5 mM Fe3+, the maximum cell density reached 1.84 × 108 cell/mL, and pH value was 0.95. In addition, metal resistance-related and sulfur metabolism genes were significantly up regulated with extra ferric iron. Taking the whole process into account, the promoting effect of Fe3+ addition can be attributed to the following: (1) alleviation of the effects of Ni2+ toxicity and restoring the growth of At. thiooxidans A01, (2) a choice of multiple pathways to export nickel ion and producing precursor of chelators of heavy metals. This can suggest that microorganisms may widely exhibit metabolic activity in iron-rich environments with heavy metals. Our study will facilitate the technique development for the processing of ore bodies with highly challenging ore compositions.
Comparison of the Partition Efficiencies of Multiple Phenolic Compounds Contained in Propolis in Different Modes of Acetonitrile–Water-Based Homogenous Liquid–Liquid Extraction
Authors: Chen Wenbin , Tu Xijuan , Wu Dehui , Gao Zhaosheng , Wu Siyuan , Huang Shaokang
Published: January 2019

Homogeneous liquid–liquid extraction (HLLE) has attracted considerable interest in the sample preparation of multi-analyte analysis. In this study, HLLEs of multiple phenolic compounds in propolis, a polyphenol-enriched resinous substance collected by honeybees, were performed for improving the understanding of the differences in partition efficiencies in four acetonitrile–water-based HLLE methods, including salting-out assisted liquid–liquid extraction (SALLE), sugaring-out assisted liquid–liquid extraction (SULLE), hydrophobic-solvent assisted liquid–liquid extraction (HSLLE), and subzero-temperature assisted liquid–liquid extraction (STLLE). Phenolic compounds were separated in reversed-phase HPLC, and the partition efficiencies in different experimental conditions were evaluated. Results showed that less-polar phenolic compounds (kaempferol and caffeic acid phenethyl ester) were highly efficiently partitioned into the upper acetonitrile (ACN) phase in all four HLLE methods. For more-polar phenolic compounds (caffeic acid, p-coumaric acid, isoferulic acid, dimethoxycinnamic acid, and cinnamic acid), increasing the concentration of ACN in the ACN–H2O mixture could dramatically improve the partition efficiency. Moreover, results indicated that NaCl-based SALLE, HSLLE, and STLLE with ACN concentrations of 50:50 (ACN:H2O, v/v) could be used for the selective extraction of low-polarity phenolic compounds. MgSO4-based SALLE in the 50:50 ACN–H2O mixture (ACN:H2O, v/v) and the NaCl-based SALLE, SULLE, and STLLE with ACN concentrations of 70:30 (ACN:H2O, v/v) could be used as general extraction methods for multiple phenolic compounds.
A Class-Selective Immunoassay for Sulfonamides Residue Detection in Milk Using a Superior Polyclonal Antibody with Broad Specificity and Highly Uniform Affinity
Authors: Li Chenglong , Luo Xiangshu , Li Yonghan , Yang Huijuan , Liang Xiao , Wen Kai , Cao Yanxin , Li Chao , Wang Weiyu , Shi Weimin , Zhang Suxia , Yu Xuezhi , Wang Zhanhui
Published: January 2019

The development of multianalyte immunoassays with an emphasis on food safety has attracted increasing interest, due to its high target throughput, short detection time, reduced sample consumption, and low overall cost. In this study, a superior polyclonal antibody (pAb) against sulfonamides (SAs) was raised by using a bioconjugate of bovine serum albumin with a rationally designed hapten 4-[(4-aminophenyl) sulfonyl-amino]-2-methoxybenzoic acid (SA10-X). The results showed that the pAb could recognize 19 SAs with 50% inhibition (IC50) below 100 µg L−1 and a recognition profile for SAs containing, either a five-atom ring or a six-atom ring, with highly uniform affinity. A three-dimensional quantitative structure-activity relationship analysis indicated that the electrostatic features of SAs play a considerably important role, during recognition with pAb than stereochemical effects. Skimmed milk samples were directly diluted five times before analysis. After optimization, the limit of detection for sulfamonomethoxine, sulfamethoxazole, sulfaquinoxaline, sulfadimethoxine, and sulfamethazine were 1.00, 1.25, 2.95, 3.35, and 6.10 µg L−1, respectively. The average recoveries for these 5 SAs were 72.0–107.5% with coefficients of variation less than 14.1%. The established method, based on pAb, with broad specificity and uniform affinity, offered a simple, sensitive, and high-throughput screening tool for the detection of multi-SAs in milk samples.
Transcriptome Analysis Clarified Genes Involved in Betalain Biosynthesis in the Fruit of Red Pitayas (Hylocereus costaricensis)
Authors: Xi Xingyuan , Zong Yuan , Li Shiming , Cao Dong , Sun Xuemei , Liu Baolong
Published: January 2019

The red flesh trait gives red pitayas more healthful components and a higher price, while the genetic mechanism behind this trait is unknown. In this manuscript, transcriptome analysis was employed to discover the genetic differences between white and red flesh in pitayas. A total of 27.99 Gb clean data were obtained for four samples. Unigenes, 79,049 in number, were generated with an average length of 1333 bp, and 52,618 Unigenes were annotated. Compared with white flesh, the expression of 10,215 Unigenes was up-regulated, and 4853 Unigenes were down-regulated in red flesh. The metabolic pathways accounted for 64.6% of all differentially expressed Unigenes in KEGG pathways. The group with high betalain content in red flesh and all structural genes, related to betalain biosynthesis, had a higher expression in red flesh than white flesh. The expression of the key gene, tyrosine hydroxylase CYP76AD1, was up-regulated 245.08 times, while 4,5-DOPA dioxygenase DODA was up-regulated 6.46 times. Moreover, the special isomers CYP76AD1α and DODAα were only expressed in red flesh. The competitive anthocyanin biosynthesis pathway had a lower expression in red flesh. Two MYB transcription factors were of the same branch as BvMYB1, regulating betalain biosynthesis in beet, and those transcription factors had expression differences in two kinds of pitayas, which indicated that they should be candidate genes controlling betalain accumulation in red pitayas. This research would benefit from identifying the major gene controlling red flesh trait and breed new cultivars with the red flesh trait. Future research should aim to prove the role of each candidate gene in betalain biosynthesis in red pitayas.