bluuebunny/crossref_metadata_2025 huggingface dataset:
Involvement of bone-specific alkaline phosphatase and procollagen I carboxy-terminal propeptide as predictors of early fracture risk in Chinese children with juvenile osteoporosis: An interventional clinical trial
Authors: Wang Yu , Zhao Jingxin , Kong Lingwei , Jin Yu
Published: May 2018

This clinical trial was designed to understand whether the children with juvenile osteoporosis receiving tablet containing vitamin D and calcium had lower incidence of bone fracture compared to the children receiving a diet rich in calcium, vitamin D, and protein. We assessed whether plasma levels of bone-specific alkaline phosphatase (BSAP) and procollagen I carboxy-terminal propeptide levels (PIPC) could be used as predictors of early bone fracture in children. A total of 120 children of either gender with a juvenile osteoporosis were enrolled and randomized (1:1 ratio) to receive tablet containing vitamin D and calcium (n=60) or diet rich in calcium, vitamin D, and protein (n=60), and undergone follow-up for up to 3 years.  Blood sample was collected and BSAP and PIPC levels were measured. The results suggested that therapeutic intervention (vitamin D and calcium) does not predict bone fracture in children. However, correlations analysis revealed that the decreased level of BSAP and PIPC were associated with higher incidence of fracture. The results suggest that the low levels of BSAP and PIPC cause increase susceptibility of fracture among children with juvenile osteoporosis.
Mechanism of the diuretic activity of Descurainia sophia seed
Authors: Zeng Mengnan , Zhang Li , Li Miao , Zhang Beibei , Feng Weisheng , Kuang Haixue , Zheng Xiaoke
Published: May 2018

The diuretic activity of the decoction and the chemical fractions of Descurainia sophia was studied with underlying mechanisms in rats. Rat metabolic cage method was used to study the diuretic activity of the decoction and the chemical fractions of D. sophia. Western blot, ELISA, ion selective electrode method and cryoscopy method were used to study the underlying mechanism. The urinary output increased significantly in rats administrated decoction. Washing elution fractions had the potent diuretic activity. Washing elution fractions could decrease the urine osmolality, increased the concentration of K+, and decreased the concentration of Na+ and ALD, also decreased the expression of aquaporin 1 (AQP1) in kidney. Moreover, compared with washing elution fractions, decoction decreased the levels of AVP, V2R, and AQP2. It is concluded that decoction had significant diuretic activity and washing elution fractions had the potent diuretic activity. The mechanisms of diuretic activity were different between decoction and washing elution fractions.
Video Clip of Methodology: 
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Healing of periapical lesion with mineral trioxide aggregate apexification
Authors: Parveen Sultana , Hossain Mozammal , Sheikh Md. Abdul Hannan , Abdin Md. Joynal
Published: May 2018

In the present study, the ability of mineral trioxide aggregate in the formation of apical plug for healing of large periapical lesion with open apex was assessed and evaluated the clinical outcome. Fifteen participants with periapical lesion at the upper anterior teeth with open apex were treated with mineral trioxide aggregate. The effect on healing of apical size was evaluated at 3, 6, and 12 months by radiological examinations in the form of periapical index criteria, diameter of the lesion size and the presence or absence of apical tissue barrier. The results found that neither pain nor any sinus was detected at 12 months. The mean size of the apical lesion was gradually reduced from 5.1 × 3.8 to 1.5 × 0.9 mm and mean PAI was reduced from 3.3 to 1.7 mm. The differences between mean size of periapical lesion at preoperative and 12 months observation period was also statistically significant (p<0.05). The clinical success shown significant success rate of 93.3% analyzed with Z-test. In conclusion, tooth with open apex can be successfully treated with mineral trioxide aggregate apexification technique followed by root canal obturation.
Adiposity indicators lipid accumulation product and triglyceride-glucose index as alternate criteria for the diagnosis of metabolic obesity in adult
Authors: Tabassum Mariya , Rahman Md. Matiur , Mozaffor Miliva
Published: May 2018

Metabolic obesity refers to the state of having metabolic syndrome irrespective of one’s body mass index. This study was aimed to elucidate the lipid accumulation product and triglyceride-glucose index as simple and alternate criteria for detecting metabolic obesity in adult. The study was conducted in 200 adult (age range: 19-45 years). According to lipid accumulation product and triglyceride-glucose index, the prevalence of metabolic obesity was 54.0% and 53.5% respectively. With a cutoff value of 45.5, the lipid accumulation product was found good to evaluate the metabolic obesity having area under receiver operating characteristic curve 0.9 (p=0.000), with sensitivity 90.9%, specificity 75.0%, positive predictive value 74.1%, and negative predictive value 91.3%. With a cutoff value of 8.7, the triglyceride-glucose index was found good to evaluate the metabolic obesity having area under receiver operating characteristic curve 0.9 (p=0.000), with sensitivity 95.5%, specificity 79.5%, positive predictive value 78.5%, and negative predictive value 95.7%. In conclusion, lipid accumulation product and triglyceride-glucose index are good as alternate criteria for diagnosing the metabolic obesity in adults.
A Modified Artificial Bee Colony Algorithm Based on the Self-Learning Mechanism
Authors: Pang Bao , Song Yong , Zhang Chengjin , Wang Hongling , Yang Runtao
Published: May 2018

Artificial bee colony (ABC) algorithm, a novel category of bionic intelligent optimization algorithm, was achieved for solving complex nonlinear optimization problems. Previous studies have shown that ABC algorithm is competitive to other biological-inspired optimization algorithms, but there still exist several insufficiencies due to the inefficient solution search equation (SSE), which does well in exploration but poorly in exploitation. To improve accuracy of the solutions, this paper proposes a modified ABC algorithm based on the self-learning mechanism (SLABC) with five SSEs as the candidate operator pool; among them, one is good at exploration and two of them are good at exploitation; another SSE intends to balance exploration and exploitation; moreover, the last SSE with Lévy flight step-size which can generate smaller step-size with high frequency and bigger step-size occasionally not only can balance exploration and exploitation but also possesses the ability to escape from the local optimum. This paper proposes a simple self-learning mechanism, wherein the SSE is selected according to the previous success ratio in generating promising solutions at each iteration. Experiments on a set of 9 benchmark functions are carried out with the purpose of evaluating the performance of the proposed method. The experimental results illustrated that the SLABC algorithm achieves significant improvement compared with other competitive algorithms.
A Fire Detection Algorithm Based on Tchebichef Moment Invariants and PSO-SVM
Authors: Bian Yongming , Yang Meng , Fan Xuying , Liu Yuchao
Published: May 2018

Automatic fire detection, which can detect and raise the alarm for fire early, is expected to help reduce the loss of life and property as much as possible. Due to its advantages over traditional methods, image processing technology has been applied gradually in fire detection. In this paper, a novel algorithm is proposed to achieve fire image detection, combined with Tchebichef (sometimes referred to as Chebyshev) moment invariants (TMIs) and particle swarm optimization-support vector machine (PSO-SVM). According to the correlation between geometric moments and Tchebichef moments, the translation, rotation, and scaling (TRS) invariants of Tchebichef moments are obtained first. Then, the TMIs of candidate images are calculated to construct feature vectors. To gain the best detection performance, a PSO-SVM model is proposed, where the kernel parameter and penalty factor of support vector machine (SVM) are optimized by particle swarm optimization (PSO). Then, the PSO-SVM model is utilized to identify the fire images. Compared with algorithms based on Hu moment invariants (HMIs) and Zernike moment invariants (ZMIs), the experimental results show that the proposed algorithm can improve the detection accuracy, achieving the highest detection rate of 98.18%. Moreover, it still exhibits the best performance even if the size of the training sample set is small and the images are transformed by TRS.
“Alperujo” Compost Improves the Ascorbate (Vitamin C) Content in Pepper (Capsicum annuum L.) Fruits and Influences Their Oxidative Metabolism
Authors: Tortosa Germán , González-Gordo Salvador , Ruiz Carmelo , Bedmar Eulogio J. , Palma José M.
Published: May 2018

“Alperujo” compost was evaluated as an organic fertiliser for pepper growth under greenhouse conditions. Even though the total nitrogen applied was similar, plants only grown with composts experienced a development decline as compared to those grown with standard nutrient solution. This was perhaps because nitrogen from the compost was essentially organic, and not easily available for roots. When, alternatively, the compost was supplemented with nitrate, a synergetic effect was observed, favouring plant development and fruit yield, simultaneously with the increase of compost rates. Compost affected the oxidative metabolism of pepper plants by increasing their antioxidative enzyme activities catalase and superoxide dismutases and the non-enzymatic antioxidants ascorbate and glutathione. Overall, when nitrogen limitation occurred and only compost was used as fertiliser, an oxidative stress took place, whereas in plants grown with nitrate-supplemented compost it did not. Furthermore, these pepper plants experienced a yield increase and, more importantly, an enhancement of the ascorbate content.
Fault Detection and Isolation for Redundant Inertial Measurement Unit under Quantization
Authors: Zhang Tong , Wang Fenfen , Fu Wenxing
Published: May 2018

Fault detection and isolation with redundant strapdown inertial measurement unit is critical for ensuring the reliability of the guidance or navigation system in the fields of both aeronautics and astronautics. Although the parity space approach is used widely, it cannot detect the soft fault which affects navigation performance under pulse quantization. This paper develops the three-channel filters to detect the soft fault and conducts theoretical implementation. The constraint conditions of their parameters are explored and the influence of the weight of different ratios is analyzed. The Monte Carlo simulation is carried out in order to verify the validity of the fault detection and isolation method. The simulation results and their analysis provide a theoretical reference for fault detection and isolation with redundant strapdown inertial measurement unit.
A Review Paper on “Graphene Field Emission for Electron Microscopy”
Authors: Shao Xiuyuan , Khursheed Anjam
Published: May 2018

Although good field emission from graphene has been demonstrated from a wide variety of different microfabricated structures, very few of them can be used to improve the design of cold field emitters for electron microscopy applications. Most of them consist of densely packed nano-emitters, which produce a large array of defocused overlapping electron beams, and therefore cannot be subsequently focused down to a single nanometer electron probe. This paper reviews the kind of single-tip cathode structures suitable in cold field emission guns for instruments such as scanning electron microscopy, transmission electron microscope or scanning transmission electron microscopy, and reviews progress in fabricating them from graphene-based materials.
Differential Signalling in Free-Space Optical Communication Systems
Authors: Mansour Abadi Mojtaba , Ghassemlooy Zabih , Bhatnagar Manav R. , Zvanovec Stanislav , Khalighi Mohammad-Ali , Lavery Martin P. J.
Published: May 2018

In this paper, we review the differential signalling techniques and investigate its implementation of in free-space optical (FSO) communication systems. The paper is an extended version of our previous works, where the effects of background noise, weak turbulence and pointing errors (PE) were investigated separately. Here, for the first time, we present a thorough description of the differential signalling scheme including for combined effects. At first, we present an extension of the analysis of differential signalling to the case of moderate to strong atmospheric turbulence. Next, we investigate a more general case where both channel turbulence and PE are taken into consideration. We provide closed-form expressions for the optimal detection threshold and the average bit-error-rate, and present a set of numerical results to illustrate the performance improvement offered by the proposed differential signalling under various turbulence and PE conditions.
Investigation of Population Dynamics in 1.54-μm Telecom Transitions of Epitaxial (ErxSc1-x)2O3 Thin Layers for Coherent Population Manipulation: Weak Excitation Regime
Authors: Adachi Satoru , Kawakami Yoshihiro , Kaji Reina , Tawara Takehiko , Omi Hiroo
Published: May 2018

We have investigated the energy transfers in the 1.54-

μ

m region of (Er,Sc)

2

O

3

epitaxial thin films grown on Si(111). The interplay of the energy transfers between Er ions in the different and the same symmetry sites makes the dynamics complicated. To suppress the energy transfer upconversion, low power and resonant excitation of the third crystal-field level (

4

I

13
/
2

:

Y

3
′

) of the Er

3
+

site with

C

3
i

symmetry was employed. The time-resolved photoluminescence measurements of the

Y

1
′

-

Z

1
′

transition indicate the existence of two decay components having fast (10–100

μ

s) and slow (0.1–1 ms) relaxation times in the range of 4–60 K. The model calculation including the inter-site energy transfers, the temperature-sensitive and -insensitive non-radiative relaxations fits the experimental results well. Moreover, the long averaged inter-Er

3
+

distance obtained by decreasing Er concentration was found to reduce two kinds of non-radiative relaxation rates and the energy transfer rates between Er ions very effectively.
Inpactor, Integrated and Parallel Analyzer and Classifier of LTR Retrotransposons and Its Application for Pineapple LTR Retrotransposons Diversity and Dynamics
Authors: Orozco-Arias Simon , Liu Juan , Tabares-Soto Reinel , Ceballos Diego , Silva Domingues Douglas , Garavito Andréa , Ming Ray , Guyot Romain
Published: May 2018

One particular class of Transposable Elements (TEs), called Long Terminal Repeats (LTRs), retrotransposons, comprises the most abundant mobile elements in plant genomes. Their copy number can vary from several hundreds to up to a few million copies per genome, deeply affecting genome organization and function. The detailed classification of LTR retrotransposons is an essential step to precisely understand their effect at the genome level, but remains challenging in large-sized genomes, requiring the use of optimized bioinformatics tools that can take advantage of supercomputers. Here, we propose a new tool: Inpactor, a parallel and scalable pipeline designed to classify LTR retrotransposons, to identify autonomous and non-autonomous elements, to perform RT-based phylogenetic trees and to analyze their insertion times using High Performance Computing (HPC) techniques. Inpactor was tested on the classification and annotation of LTR retrotransposons in pineapple, a recently-sequenced genome. The pineapple genome assembly comprises 44% of transposable elements, of which 23% were classified as LTR retrotransposons. Exceptionally, 16.4% of the pineapple genome assembly corresponded to only one lineage of the Gypsy superfamily: Del, suggesting that this particular lineage has undergone a significant increase in its copy numbers. As demonstrated for the pineapple genome, Inpactor provides comprehensive data of LTR retrotransposons’ classification and dynamics, allowing a fine understanding of their contribution to genome structure and evolution. Inpactor is available at https://github.com/simonorozcoarias/Inpactor.
Protein Solvent-Accessibility Prediction by a Stacked Deep Bidirectional Recurrent Neural Network
Authors: Zhang Buzhong , Li Linqing , Lü Qiang
Published: May 2018

Residue solvent accessibility is closely related to the spatial arrangement and packing of residues. Predicting the solvent accessibility of a protein is an important step to understand its structure and function. In this work, we present a deep learning method to predict residue solvent accessibility, which is based on a stacked deep bidirectional recurrent neural network applied to sequence profiles. To capture more long-range sequence information, a merging operator was proposed when bidirectional information from hidden nodes was merged for outputs. Three types of merging operators were used in our improved model, with a long short-term memory network performing as a hidden computing node. The trained database was constructed from 7361 proteins extracted from the PISCES server using a cut-off of 25% sequence identity. Sequence-derived features including position-specific scoring matrix, physical properties, physicochemical characteristics, conservation score and protein coding were used to represent a residue. Using this method, predictive values of continuous relative solvent-accessible area were obtained, and then, these values were transformed into binary states with predefined thresholds. Our experimental results showed that our deep learning method improved prediction quality relative to current methods, with mean absolute error and Pearson’s correlation coefficient values of 8.8% and 74.8%, respectively, on the CB502 dataset and 8.2% and 78%, respectively, on the Manesh215 dataset.
Experimental Methods for Studying Cellular Heme Signaling
Authors: Comer Jonathan M. , Zhang Li
Published: May 2018

The study of heme is important to our understanding of cellular bioenergetics, especially in cancer cells. The function of heme as a prosthetic group in proteins such as cytochromes is now well-documented. Less is known, however, about its role as a regulator of metabolic and energetic pathways. This is due in part to some inherent difficulties in studying heme. Due to its slightly amphiphilic nature, heme is a “sticky” molecule which can easily bind non-specifically to proteins. In addition, heme tends to dimerize, oxidize, and aggregate in purely aqueous solutions; therefore, there are constraints on buffer composition and concentrations. Despite these difficulties, our knowledge of heme’s regulatory role continues to grow. This review sums up the latest methods used to study reversible heme binding. Heme-regulated proteins will also be reviewed, as well as a system for imaging the cellular localization of heme.
Human-Induced Pluripotent Stem Cell Technology and Cardiomyocyte Generation: Progress and Clinical Applications
Authors: Di Baldassarre Angela , Cimetta Elisa , Bollini Sveva , Gaggi Giulia , Ghinassi Barbara
Published: May 2018

Human-induced pluripotent stem cells (hiPSCs) are reprogrammed cells that have hallmarks similar to embryonic stem cells including the capacity of self-renewal and differentiation into cardiac myocytes. The improvements in reprogramming and differentiating methods achieved in the past 10 years widened the use of hiPSCs, especially in cardiac research. hiPSC-derived cardiac myocytes (CMs) recapitulate phenotypic differences caused by genetic variations, making them attractive human disease models and useful tools for drug discovery and toxicology testing. In addition, hiPSCs can be used as sources of cells for cardiac regeneration in animal models. Here, we review the advances in the genetic and epigenetic control of cardiomyogenesis that underlies the significant improvement of the induced reprogramming of somatic cells to CMs; the methods used to improve scalability of throughput assays for functional screening and drug testing in vitro; the phenotypic characteristics of hiPSCs-derived CMs and their ability to rescue injured CMs through paracrine effects; we also cover the novel approaches in tissue engineering for hiPSC-derived cardiac tissue generation, and finally, their immunological features and the potential use in biomedical applications.
Alanine Aminotransferase as a Monitoring Biomarker in Children with Nonalcoholic Fatty Liver Disease: A Secondary Analysis Using TONIC Trial Data
Authors: Arsik Idil , Frediani Jennifer K. , Frezza Damon , Chen Wen , Ayer Turgay , Keskinocak Pinar , Jin Ran , Konomi Juna V. , Barlow Sarah E. , Xanthakos Stavra A. , Lavine Joel E. , Vos Miriam B.
Published: May 2018

Background: Validated noninvasive biomarkers to assess treatment response in pediatric nonalcoholic fatty liver disease (NAFLD) are lacking. We aimed to validate alanine aminotransferase (ALT), a monitoring biomarker for change in liver histology. Methods: A retrospective analysis using data from the TONIC trial. NAFLD histologic assessments were defined by: Fibrosis score, NAFLD activity score (NAS), nonalcoholic steatohepatitis (NASH), and a combination of NASH resolution and fibrosis (NASH + fibrosis). Analysis was performed using classification and regression trees (CART) as well as logistic regression. Results: Mean ALT for the child over 96 weeks and percent change of ALT from baseline to 96 weeks were significant predictors of progression of NAFLD for each histologic assessment (p < 0.001 for fibrosis score, NASH, and NASH + fibrosis and p < 0.05 for NAS). Mean ALT adjusted for age, sex and ethnicity was a better predictor for change in NASH (81.8 (11.0) ROC (receiver operating characteristic curve) mean (SD (Standard derivation))) and NASH + fibrosis (77.8 (11.2)), compared to change in NAS (63 (17.7)) and fibrosis (58.6 (11.1)). Conclusion: Mean ALT over 96 weeks is a reasonable proxy of histologic improvement of NASH and NASH + fibrosis. These findings support ALT as a valid monitoring biomarker of histologic change over time in children with NASH and fibrosis.
Ba4[Mn3N6], a Quasi-One-Dimensional Mixed-Valent Nitridomanganate (II, IV)
Authors: Ovchinnikov Alexander , Bobnar Matej , Prots Yurii , Schnelle Walter , Höhn Peter , Grin Yuri
Published: May 2018

The mixed-valent nitridomanganate Ba4[Mn3N6] was prepared using a gas–solid high temperature route. The crystal structure was determined employing high resolution synchrotron powder diffraction data: space group Pbcn, a = 9.9930(1) Å, b = 6.17126(8) Å, c = 14.4692(2) Å, V = 892.31(2) Å3, Z = 4. The manganese atoms in the structure of Ba4[Mn3N6] are four-fold coordinated by nitrogen forming infinite corrugated chains of edge-sharing [MnN4] tetrahedra. The chains demonstrate a complete charge order of Mn species. Magnetization measurements and first principle calculations indicate quasi-one dimensional magnetic behavior. In addition, chemical bonding analysis revealed pronounced Mn–Mn interactions along the chains.
Coordination Behavior of Bis-Imidazole and Various Carboxylate Ligands towards Zn(II) and Cd(II) Ions: Synthesis, Structure, and Photoluminescence Study
Authors: Liu Kang , Deng Liming , Zhang Yaowen , Jiao Shaoshao , Geng Yanling , Wang Lei
Published: May 2018

Four coordination polymers (CPs) based on bis-imidazole ligands (1,2-bimb and 1,2-bmimb), namely, {[Zn(1,2-bimb)(2,5-dtpa)] H2O}n (1), {[Cd2(1,2-bimb)2(5-hipa)2] 2H2O} (2), {Zn2(1,2-bimb)(L)(CH3COO) DMF·2H2O}n (3) and {Cd(1,2-bmimb)(3-npa)}n (4), have been synthesized by solvothermal reactions (1,2-bimb = 1,2-bis((1H-imidazol-1-yl)methyl)benzene, 1,2-bmimb = 1,2-bis((2-methyl-1H-imidazol-1-yl)methyl)benzene, 2,5-H2dtpa = 2,5-diaminoterephthalic acid, 5-H2hipa = 5-hydroxyisophthalic acid, H3L= 3,3′,3′′-(2,4,6-trioxo-1,3,5-triazinane-1,3,5-triyl)tripropanoic acid, 3-H2npa = 3-nitrophthalic acid) and structurally verified by single-crystal X-ray diffraction analyses and further characterized by powder X-ray diffraction (PXRD), elemental analyses and infrared spectroscopy (IR). Complex 1 and 2 show a dinuclear 2D layered structure. Complex 4 exhibits a two-dimensional network consisting of [Cd(3-npa)]n and [Cd(1,2-bmimb)]n chains. Both 1,2 and 4 display a 4-connected sql topology sheet, which can be further expanded into a 3D supramolecular network through π···π interaction between layers. Complex 3 features a 3D (3,6)-connected {42·6}·{44·610·8}-3,6T24 topology structure consisting of 2D bilayers. Structural comparison reveals that it is not only the substituents at different positions of ancillary ligands and the primary bis(imidazole) linkers that play crucial roles in the control of the final structures. Besides, the photoluminescence properties of 1–4 have been investigated in the solid state at room temperature.
An Influence of Thermally-Induced Micro-Cracking under Cooling Treatments: Mechanical Characteristics of Australian Granite
Authors: Isaka Badulla Liyanage Avanthi , Gamage Ranjith Pathegama , Rathnaweera Tharaka Dilanka , Perera Mandadige Samintha Anne , Chandrasekharam Dornadula , Kumari Wanniarachchige Gnamani Pabasara
Published: May 2018

The aim of this study is to characterise the changes in mechanical properties and to provide a comprehensive micro-structural analysis of Harcourt granite over different pre-heating temperatures under two cooling treatments (1) rapid and (2) slow cooling. A series of uniaxial compression tests was conducted to evaluate the mechanical properties of granite specimens subjected to pre-heating to temperatures ranging from 25–1000 °C under both cooling conditions. An acoustic emission (AE) system was incorporated to identify the fracture propagation stress thresholds. Furthermore, the effect of loading and unloading behaviour on the elastic properties of Harcourt granite was evaluated at two locations prior to failure: (1) crack initiation and (2) crack damage. Scanning electron microscopy (SEM) analyses were conducted on heat-treated thin rock slices to observe the crack/fracture patterns and to quantify the extent of micro-cracking during intense heating followed by cooling. The results revealed that the thermal field induced in the Harcourt granite pore structure during heating up to 100 °C followed by cooling causes cracks to close, resulting in increased mechanical characteristics, in particular, material stiffness and strength. Thereafter, a decline in mechanical properties occurs with the increase of pre-heating temperatures from 100 °C to 800 °C. However, the thermal deterioration under rapid cooling is much higher than that under slow cooling, because rapid cooling appears to produce a significant amount of micro-cracking due to the irreversible thermal shock induced. Multiple stages of loading and unloading prior to failure degrade the elastic properties of Harcourt granite due to the damage accumulated through the coalescence of micro-cracks induced during compression loading. However, this degradation is insignificant for pre-heating temperatures over 400 °C, since the specimens are already damaged due to excessive thermal deterioration. Moreover, unloading after crack initiation tends to cause insignificant irreversible strains, whereas significant permanent strains occur during unloading after crack damage, and this appears to increase with the increase of pre-heating temperature over 400 °C.
Biofuel and Biochemical Analysis of Amphora coffeaeformis RR03, a Novel Marine Diatom, Cultivated in an Open Raceway Pond
Authors: Rajaram Muthu Ganesan , Nagaraj Subramani , Manjunath Manubolu , Boopathy Annakkili Baskara , Kurinjimalar Chidambaram , Rengasamy Ramasamy , Jayakumar Thanasekaran , Sheu Joen-Rong , Li Jiun-Yi
Published: May 2018

(1) Background: To increase the biochemical productivity and to reduce the production cost of microalgal biodiesel, this study aimed to investigate the effects of CO2 on biomass, fatty acids, carbon-hydrogen, and biochemical accumulation of the marine diatom, Amphora coffeaeformis RR03 (A. coffeaeformis) RR03. (2) Methods: Fatty acid composition of the dry biomass of A. coffeaeformis RR03 was analysed using Gas chromatography-mass spectrometry (GC-MS). (3) Results: The results showed that A. coffeaeformis RR03 contained high biomass productivity and biochemical composition in different cultivation conditions. A. coffeaeformis RR03 showed maximum growth of 5.2 × 106/mL on 21st day cultivation under CO2 supply. The bio-crude oil production from A. coffeaeformis RR03 was 36.19 megajoule (MJ). GC-MS analysis found that the dry biomass of A. coffeaeformis RR03 contained maximum of 47.72% fatty acids of 16-octadecanoic acid methyl ester (10:12) and 19.58% pentadecanoic acid, 13-methyl-, and methyl ester (9.24). (4) Conclusion: The results of this study may suggest that a novel diatom of A. coffeaeformis RR03 could be a suitable candidate for biocrude production in order to meet the future demand of energy.
Experimental Investigation into the Effect of Oil Injection on the Performance of a Variable Speed Twin-Screw Compressor
Authors: He Zhilong , Wang Tao , Wang Xiaolin , Peng Xueyuan , Xing Ziwen
Published: May 2018

In this paper, the effect of oil injection flow rate on the performance of a variable speed twin-screw compressor was investigated experimentally. Comprehensive experiments were conducted at different compressor rotational speeds and oil injection flow rates. As the rotational speed increased from 1000 to 3000 rpm, the compressor volumetric and adiabatic efficiencies increased while the specific power consumption decreased. However, the oil injection flow rate showed different influences on the compressor performance. As the oil injection flow rate increased from 27 to 50 L/min, the adiabatic and volumetric efficiencies increased while the compressor discharge temperature and specific power decreased. Further increases in the oil injection flow rate had little effect on compressor performance at flow rates above 50 L/min. The analysis indicated that the oil injection flow rate was limited by the discharge temperature at low compressor rotational speeds and was a trade-off among two efficiencies and specific power consumption at high rotational speeds.
Influence of Single/Dual Ventilation Path on Fluid Field and Temperature Field of HVLSSR-PMSM with Air-Cooled Hybrid Ventilation Systems
Authors: Cao Zhaobin , Li Weili , Zhang Xiaochen , Fan Yu , Zeng Jianjun
Published: May 2018

Due to the solid rotor structure, High-Voltage Line-Start Solid Rotor Permanent Magnet Synchronous Motor (HVLSSR-PMSM) operates with high rotor temperature rise. If the ventilation path cannot take the rotor heat away in time, the rotor will overheat or even may led to the thermal demagnetization for permanent magnet. Therefore, it is of great significance to study the thermal issues of HVLSSR-PMSM. In the paper, the fluid field and temperature field of a 315 kW, 6 kV HVLSSR-PMSM with air-cooled hybrid ventilation systems are investigated. Firstly, the electromagnetic analysis of the machine is done by using the finite-element method, the loss distributions then are obtained, which will be assigned as the heat source for thermal analysis. Then, the three -dimensional (3-D) fluid thermal coupled mathematical model for thermal analysis of HVLSSR-PMSM is established. The temperature field and the fluid flowing state of HVLSSR-PMSM with single ventilation path air-cooled system are investigated by using the established 3D fluid thermal coupled mathematical model. A dual ventilation path air-cooled system for HVLSSR-PMSM is proposed to reduce the operating temperature rise. Then, the temperature field and fluid field of HVLSSR-PMSM with dual ventilation system are analyzed by comparing with single ventilation system. Moreover, the temperature experiments are carried out on the machine with dual ventilation system to validate the accuracy of the established mathematical models. The results show that the proposed dual ventilation path air-cooled system can effectively improve the thermal distribution of HVLSSR-PMSM, whilst it can also reduce the working temperature rise of the machine.
Effect of Different Operating Temperatures on the Biological Hydrogen Methanation in Trickle Bed Reactors
Authors: Lemmer Andreas , Ullrich Timo
Published: May 2018

To improve the reactor efficiency, this study investigated the influence of temperature on the biological hydrogen methanation (BHM) in trickle-bed reactors (TBR). Rising temperatures increase the metabolic activity of methanogenic microorganisms, thus leading to higher reactor specific methane formation rates (MFR). In order to quantify the potential for improved performance, experiments with four different operating temperatures ranging from 40 to 55 °C were carried out. Methane content increased from 88.29 ± 2.12 vol % at 40 °C to 94.99 ± 0.81 vol % at 55 °C with a stable biological process. Furthermore, a reactor specific methane formation rate (MFR) of up to 8.85 ± 0.45 m3 m−3 d−1 was achieved. It could be shown that the microorganisms were able to adapt to higher temperatures within hours. The tests showed that TBR performance with regard to BHM can be significantly increased by increasing the operating temperature.
Risk Constrained Trading Strategies for Stochastic Generation with a Single-Price Balancing Market
Authors: Browell Jethro
Published: May 2018

Trading energy from wind and other forms of stochastic generation in competitive electricity markets is challenging due to the limited predictability of these resources. This paper examines the specific case of single-price balancing markets and derives risk-constrained strategies in a probabilistic framework, going beyond the trivial zero/max solution, which would have participants offer either zero or their maximum energy production based on a prediction of whether the system will be in net up- or down-regulation. The zero/max approach is unacceptable in reality as it exposes the participant to potentially huge imbalance charges, and would violate price taker assumption for a portfolio of significant size. Here, we propose several trading strategies that control risk by hedging against penalising balancing prices in favour of rewarding ones by contracting forecast generation plus some adjustment. These strategies are formulated in a probabilistic framework to address the presence of forecast uncertainty and asymmetric costs in balancing markets. A case study using data from the Great Britain electricity market is presented and it is shown that the proposed strategies are able to simultaneously increase revenue and reduce risk using risk-constrained strategies. Furthermore, the required forecasts of electricity prices and system length are produced using standard tools and widely available explanatory information and are found to have sufficient skill to increase revenue compared to not hedging.
Comparison of Shell and Solid Finite Element Models for the Static Certification Tests of a 43 m Wind Turbine Blade
Authors: Peeters Mathijs , Santo Gilberto , Degroote Joris , Van Paepegem Wim
Published: May 2018

A commercial 43 m wind turbine blade was tested under static loads. During these tests, loads, displacements, and local strains were recorded. In this work, the blade was modeled using the finite element method. Both a segment of the spar structure and the full-scale blade were modeled. In both cases, conventional outer mold layer shell and layered solid models were created by means of an in-house developed software tool. First, the boundary conditions and settings for modeling the tests were explored. Next, the behavior of a spar segment under different modeling methods was investigated. Finally, the full-scale blade tests were conducted. The resulting displacements and longitudinal and transverse strains were investigated. It was found that for the considered load case, the differences between the shell and solid models are limited. Thus, it is concluded that the shell representation is sufficiently accurate.
Assessment of Explicit Models for Different Photovoltaic Technologies
Authors: Pindado Santiago , Cubas Javier , Roibás-Millán Elena , Bugallo-Siegel Francisco , Sorribes-Palmer Félix
Published: May 2018

Accurate and simple mathematical models are usually required to assess the performances of photovoltaic devices. In particular, it is common practice to use explicit models to evaluate the current–voltage (I–V) performance curves, mainly based on simple analytical expressions that enable the parameters determination with a little computational effort. Six different explicit photovoltaic models (i.e., explicit I–V equations) by different authors (Akbaba & Alattawi; El-Tayyan; Karmalkar & Haneefa; Das/Saetre et al.; Das; and Pindado & Cubas) are analyzed and compared. This comparison is carried out by fitting these models to eight I–V curves for different technologies, including Si, Si polycrystalline, Ga–As, and plastic solar cells. The accuracy of each model depends on the photovoltaic technology to which it is applied. The best fit to each I–V curve studied is normally obtained with a different model, with an average deviation under 2% in terms of short-circuit current (normalized RMSE). In general, the model proposed by Karmalkar & Haneefa shows the highest level of accuracy, and is a good fit for all I–V curves studied.
Probing Black Hole Magnetic Fields with QED
Authors: Caiazzo Ilaria , Heyl Jeremy
Published: May 2018

The effect of vacuum birefringence is one of the first predictions of quantum electrodynamics (QED): the presence of a charged Dirac field makes the vacuum birefringent when threaded by magnetic fields. This effect, extremely weak for terrestrial magnetic fields, becomes important for highly magnetized astrophysical objects, such as accreting black holes. In the X-ray regime, the polarization of photons traveling in the magnetosphere of a black hole is not frozen at emission but is changed by the local magnetic field. We show that, for photons traveling along the plane of the disk, where the field is expected to be partially organized, this results in a depolarization of the X-ray radiation. Because the amount of depolarization depends on the strength of the magnetic field, this effect can provide a way to probe the magnetic field in black-hole accretion disks and to study the role of magnetic fields in astrophysical accretion in general.
Transitions from Single- to Multi-Locus Processes during Speciation with Gene Flow
Authors: Schilling Martin P. , Mullen Sean P. , Kronforst Marcus , Safran Rebecca J. , Nosil Patrik , Feder Jeffrey L. , Gompert Zachariah , Flaxman Samuel M.
Published: May 2018

During speciation-with-gene-flow, a transition from single-locus to multi-locus processes can occur, as strong coupling of multiple loci creates a barrier to gene flow. Testing predictions about such transitions with empirical data requires building upon past theoretical work and the continued development of quantitative approaches. We simulated genomes under several evolutionary scenarios of gene flow and divergent selection, extending previous work with the additions of neutral sites and coupling statistics. We used these simulations to investigate, in a preliminary way, if and how selected and neutral sites differ in the conditions they require for transitions during speciation. For the parameter combinations we explored, as the per-locus strength of selection grew and/or migration decreased, it became easier for selected sites to show divergence—and thus to rise in linkage disequilibrium (LD) with each other as a statistical consequence—farther in advance of the conditions under which neutral sites could diverge. Indeed, even very low rates of effective gene flow were sufficient to prevent differentiation at neutral sites. However, once strong enough, coupling among selected sites eventually reduced gene flow at neutral sites as well. To explore whether similar transitions might be detectable in empirical data, we used published genome resequencing data from three taxa of Heliconius butterflies. We found that fixation index ( F S T ) outliers and allele-frequency outliers exhibited stronger patterns of within-deme LD than the genomic background, as expected. The statistical characteristics of within-deme LD—likely indicative of the strength of coupling of barrier loci—varied between chromosomes and taxonomic comparisons. Qualitatively, the patterns we observed in the empirical data and in our simulations suggest that selection drives rapid genome-wide transitions to multi-locus coupling, illustrating how divergence and gene flow interact along the speciation continuum.
Fecal Distribution Changes Using Colorectal Ultrasonography in Older People with Physical and Cognitive Impairment Living in Long-Term Care Facilities: A Longitudinal Observational Study
Authors: Tanaka Shiho , Yabunaka Koichi , Matsumoto Masaru , Tamai Nao , Noguchi Hiroshi , Yoshida Mikako , Nakagami Gojiro , Sugama Junko , Sanada Hiromi
Published: May 2018

Nurses encounter difficulties evaluating constipation in elderly people with physical and cognitive impairment. Transabdominal ultrasonography (US) has been used to evaluate fecal impaction or fecal quality. However, it is unclear whether colorectal US can evaluate constipation symptoms in older people. Using colorectal US, we continuously observed the elderly and clarified the relationship between patterns of fecal distribution changes and constipation symptoms in older people with physical and cognitive impairment at long-term care facilities. This study included patients aged ≥65 years with oral intake. US was performed once a day until the next defecation, and fecal hardness was assessed. US images were extracted and categorized. Then, patterns of fecal distribution changes in the colorectum were classified. Multiple logistic regression analysis was performed to examine related factors associated with a constipation pattern. Among 101 patients, US images of 95 patients were analyzed. In 74.4% of the patients, US showed continuation of reflection with acoustic shadow in the rectum, which was significantly associated with defecation on the bed. Of the patients with a continuous crescent-shaped reflection pattern (R3), 92.9% had hard stool. R3 was found to be significantly associated with a Mini-Mental State Examination score of ≤10. In most of the patients, US detected a continuation of reflection with acoustic shadow in rectal patterns, indicating fecal retention in the rectum. Point-of-care US can be used by nurses to visualize rectal fecal retention as constipation patterns in the older people with physical and cognitive impairment at long-term care facilities.
Early Childhood Caries-Related Knowledge, Attitude, and Practice: Discordance between Pediatricians and Dentists toward Medical Office-Based Prevention in Taiwan
Authors: Dima Shinechimeg , Chang Wei-Jen , Chen Jung-Wei , Teng Nai-Chia
Published: May 2018

The aim of this study was to assess the knowledge, attitude, and practice regarding early childhood caries (ECC) prevention and implementation of medical setting-based caries prevention among pediatricians and dentists in Taiwan. Data were collected from currently practicing pediatricians and general and pediatric dentists using self-administered questionnaires. A total of 301 questionnaires were completed by the pediatricians (n = 105), general dentists (n = 117), and pediatric dentists (n = 79). The pediatric dentists obtained significantly higher knowledge and practice scores than the general dentists and pediatricians (p < 0.0001). The pediatricians’ attitude score related to engaging physicians in medical office-based caries prevention was significantly higher than the attitude scores of the general and pediatric dentists (p < 0.05). A Spearman rank correlation analysis indicated a significant positive correlation between knowledge and practice among the general dentists (rs = 0.271, p < 0.01) and pediatricians (rs = 0.262, p < 0.01). The correlation between knowledge and attitude among the pediatricians was significantly positive (rs = 0.242, p < 0.05). Attitude and practice among the pediatricians were significantly positively correlated (rs = 0.271, p < 0.01). Pediatricians lacked ECC-related knowledge; however, they had a more positive attitude toward medical office-based prevention when they had a higher level of knowledge. Oral health-related education for pediatricians is necessary if such medical office-based caries prevention programs are to be implemented in Taiwan.
Signaling Crosstalk of TGF-β/ALK5 and PAR2/PAR1: A Complex Regulatory Network Controlling Fibrosis and Cancer
Authors: Ungefroren Hendrik , Gieseler Frank , Kaufmann Roland , Settmacher Utz , Lehnert Hendrik , Rauch Bernhard H.
Published: May 2018

Both signaling by transforming growth factor-β (TGF-β) and agonists of the G Protein-coupled receptors proteinase-activated receptor-1 (PAR1) and -2 (PAR2) have been linked to tissue fibrosis and cancer. Intriguingly, TGF-β and PAR signaling either converge on the regulation of certain matrix genes overexpressed in these pathologies or display mutual regulation of their signaling components, which is mediated in part through sphingosine kinases and sphingosine-1-phosphate and indicative of an intimate signaling crosstalk between the two pathways. In the first part of this review, we summarize the various regulatory interactions that have been discovered so far according to the organ/tissue in which they were described. In the second part, we highlight the types of signaling crosstalk between TGF-β on the one hand and PAR2/PAR1 on the other hand. Both ligand–receptor systems interact at various levels and by several mechanisms including mutual regulation of ligand–ligand, ligand–receptor, and receptor–receptor at the transcriptional, post-transcriptional, and receptor transactivation levels. These mutual interactions between PAR2/PAR1 and TGF-β signaling components eventually result in feed-forward loops/vicious cycles of matrix deposition and malignant traits that exacerbate fibrosis and oncogenesis, respectively. Given the crucial role of PAR2 and PAR1 in controlling TGF-β receptor activation, signaling, TGF-β synthesis and bioactivation, combining PAR inhibitors with TGF-β blocking agents may turn out to be more efficient than targeting TGF-β alone in alleviating unwanted TGF-β-dependent responses but retaining the beneficial ones.
Na+-Dependent High-Affinity Nitrate, Phosphate and Amino Acids Transport in Leaf Cells of the Seagrass Posidonia oceanica (L.) Delile
Authors: Rubio Lourdes , García-Pérez Delia , García-Sánchez María Jesús , Fernández José A.
Published: May 2018

Posidonia oceanica (L.) Delile is a seagrass, the only group of vascular plants to colonize the marine environment. Seawater is an extreme yet stable environment characterized by high salinity, alkaline pH and low availability of essential nutrients, such as nitrate and phosphate. Classical depletion experiments, membrane potential and cytosolic sodium measurements were used to characterize the high-affinity NO3−, Pi and amino acids uptake mechanisms in this species. Net uptake rates of both NO3− and Pi were reduced by more than 70% in the absence of Na+. Micromolar concentrations of NO3− depolarized mesophyll leaf cells plasma membrane. Depolarizations showed saturation kinetics (Km = 8.7 ± 1 μM NO3−), which were not observed in the absence of Na+. NO3− induced depolarizations at increasing Na+ also showed saturation kinetics (Km = 7.2 ± 2 mM Na+). Cytosolic Na+ measured in P. oceanica leaf cells (17 ± 2 mM Na+) increased by 0.4 ± 0.2 mM Na+ upon the addition of 100 μM NO3−. Na+-dependence was also observed for high-affinity l-ala and l-cys uptake and high-affinity Pi transport. All together, these results strongly suggest that NO3−, amino acids and Pi uptake in P. oceanica leaf cells are mediated by high-affinity Na+-dependent transport systems. This mechanism seems to be a key step in the process of adaptation of seagrasses to the marine environment.