bluuebunny/crossref_metadata_2025 huggingface dataset:
Mammary Gland Transcriptome and Proteome Modifications by Nutrient Restriction in Early Lactation Holstein Cows Challenged with Intra-Mammary Lipopolysaccharide
Authors: Pawłowski Karol , Pires José A. A. , Faulconnier Yannick , Chambon Christophe , Germon Pierre , Boby Céline , Leroux Christine
Published: March 2019

The objective is to study the effects of nutrient restrictions, which induce a metabolic imbalance on the inflammatory response of the mammary gland in early lactation cows. The aim is to decipher the molecular mechanisms involved, by comparing a control, with a restriction group, a transcriptome and proteome, after an intra-mammary lipopolysaccharide challenge. Multi-parous cows were either allowed ad libitum intake of a lactation diet (n = 8), or a ration containing low nutrient density (n = 8; 48% barley straw and dry matter basis) for four days starting at 24 ± 3 days in milk. Three days after the initiation of their treatments, one healthy rear mammary quarter of 12 lactating cows was challenged with 50 µg of lipopolysaccharide (LPS). Transcriptomic and proteomic analyses were performed on mammary biopsies obtained 24 h after the LPS challenge, using bovine 44K microarrays, and nano-LC-MS/MS, respectively. Restriction-induced deficits in energy, led to a marked negative energy balance (41 versus 97 ± 15% of Net Energy for Lactation (NEL) requirements) and metabolic imbalance. A microarray analyses identified 25 differentially expressed genes in response to restriction, suggesting that restriction had modified mammary metabolism, specifically β-oxidation process. Proteomic analyses identified 53 differentially expressed proteins, which suggests that the modification of protein synthesis from mRNA splicing to folding. Under-nutrition influenced mammary gland expression of the genes involved in metabolism, thereby increasing β-oxidation and altering protein synthesis, which may affect the response to inflammation.
Detecting Emotions in English and Arabic Tweets
Authors: Ahmad Tariq , Ramsay Allan , Ahmed Hanady
Published: March 2019

Assigning sentiment labels to documents is, at first sight, a standard multi-label classification task. Many approaches have been used for this task, but the current state-of-the-art solutions use deep neural networks (DNNs). As such, it seems likely that standard machine learning algorithms, such as these, will provide an effective approach. We describe an alternative approach, involving the use of probabilities to construct a weighted lexicon of sentiment terms, then modifying the lexicon and calculating optimal thresholds for each class. We show that this approach outperforms the use of DNNs and other standard algorithms. We believe that DNNs are not a universal panacea and that paying attention to the nature of the data that you are trying to learn from can be more important than trying out ever more powerful general purpose machine learning algorithms.
Glomerular Filtration Rate Estimation by a Novel Numerical Binning-Less Isotonic Statistical Bivariate Numerical Modeling Method
Authors: Giles Sebastian Nicolas , Fiori Simone
Published: March 2019

Statistical bivariate numerical modeling is a method to infer an empirical relationship between unpaired sets of data based on statistical distributions matching. In the present paper, a novel efficient numerical algorithm is proposed to perform bivariate numerical modeling. The algorithm is then applied to correlate glomerular filtration rate to serum creatinine concentration. Glomerular filtration rate is adopted in clinical nephrology as an indicator of kidney function and is relevant for assessing progression of renal disease. As direct measurement of glomerular filtration rate is highly impractical, there is considerable interest in developing numerical algorithms to estimate glomerular filtration rate from parameters which are easier to obtain, such as demographic and ‘bedside’ assays data.
Current Advances in Ejector Modeling, Experimentation and Applications for Refrigeration and Heat Pumps. Part 1: Single-Phase Ejectors
Authors: Aidoun Zine , Ameur Khaled , Falsafioon Mehdi , Badache Messaoud
Published: March 2019

Ejectors used in refrigeration systems as entrainment and compression components or expanders, alone or in combination with other equipment devices, have gained renewed interest from the scientific community as a means of low temperature heat recovery and more efficient energy use. This paper summarizes the main findings and trends, in the area of heat-driven ejectors and ejector-based machines, using low boiling point working fluids, which were reported in the literature for a number of promising applications. An overall view of such systems is provided by discussing the ejector physics principles, as well as a review of the main developments in ejectors over the last few years. Recent achievements on thermally activated ejectors for single-phase compressible fluids are the main focus in this part of the review. Aspects related to their design, operation, theoretical and experimental approaches employed, analysis of the complex interacting phenomena taking place within the device, and performance are highlighted. Conventional and improved ejector refrigeration cycles are discussed. Some cycles of interest employing ejectors alone or boosted combinations are presented and their potential applications are indicated.
Chronic Bacterial Infection Prevalence, Risk Factors, and Characteristics: A Bronchiectasis Population-Based Prospective Study
Authors: Amorim Adelina , Meira Leonor , Redondo Margarida , Ribeiro Manuela , Castro Ricardo , Rodrigues Márcio , Martins Natália , Hespanhol Venceslau
Published: March 2019

Background: Few data are available on chronic bacterial infections (CBI) in bronchiectasis patients. Given that CBI seems to trigger longer hospital stays, worse outcomes, and morbimortality, this study was undertaken to assess CBI prevalence, characteristics, and risk factors in outpatients with bronchiectasis. Methods: A total of 186 patients followed in a bronchiectasis tertiary referral centre in Portugal were included. Demographic data and information on aetiology, smoking history, mMRC score, Bronchiectasis Severity Index (BSI) score, sputum characteristics, lung function, exacerbations, and radiological involvement degree were collected. Results: Patients included (mean age 54.7 ± 16.2 years; 60.8% females) were followed up for a period of 3.8 ± 1.7 years. The most common cause of bronchiectasis was infection (31.7%) followed by immune deficiencies (11.8%), whereas in 29% of cases, no cause was identified. Haemophilus influenzae (32.3%) and Pseudomonas aeruginosa (30.1%) were the most common CBI-associated possible pathogenic microorganisms. CBI patients presented a higher follow-up time than no-CBI patients (p = 0.003), worse lung function, BSI (p < 0.001), and radiological (p < 0.001) scores, and more prominent daily sputum production (p = 0.002), estimated mean volume (p < 0.001), and purulent sputum (p < 0.001). The number of exacerbations/year (p = 0.001), including those requiring hospital admission (p = 0.009), were also higher in the CBI group. Independent CBI predictors were BSI score (OR 3.577, 95% CI 1.233–10.378), sputum characteristics (OR 3.306, 95% CI 1.107–9.874), and radiological score (OR 1.052, 95% CI 1.004–1.102). Conclusion: According to the CBI status, two different sub-groups of patients were found on the basis of several clinical outcomes, emphasizing the importance of routine sputum microbiological monitoring. Further studies are needed to better characterize CBI profiles and to define the individual clinical impact of the most prevalent pathogenic microorganisms.
The Challenges of Diagnostic Imaging in the Era of Big Data
Authors: Aiello Marco , Cavaliere Carlo , D’Albore Antonio , Salvatore Marco
Published: March 2019

The diagnostic imaging field has undergone considerable growth both in terms of technological development and market expansion; with the following increasing production of a considerable amount of data that potentially fully poses diagnostic imaging in the Big data in the context of healthcare. Nevertheless, the mere production of a large amount of data does not automatically permit the real exploitation of their intrinsic value. Therefore, it is necessary to develop digital platforms and applications that favor the correct and advantageous management of diagnostic images such as Big data. This work aims to frame the role of diagnostic imaging in this new scenario, emphasizing the open challenges in exploiting such intense data generation for decision making with Big data analytics.
Association of Glucose Fluctuations with Sarcopenia in Older Adults with Type 2 Diabetes Mellitus
Authors: Ogama Noriko , Sakurai Takashi , Kawashima Shuji , Tanikawa Takahisa , Tokuda Haruhiko , Satake Shosuke , Miura Hisayuki , Shimizu Atsuya , Kokubo Manabu , Niida Shumpei , Toba Kenji , Umegaki Hiroyuki , Kuzuya Masafumi
Published: March 2019

Type 2 diabetes mellitus accelerates loss of muscle mass and strength. Patients with Alzheimer’s disease (AD) also show these conditions, even in the early stages of AD. The mechanism linking glucose management with these muscle changes has not been elucidated but has implications for clarifying these associations and developing preventive strategies to maintain functional capacity. This study included 69 type 2 diabetes patients with a diagnosis of cognitive impairment (n = 32) and patients with normal cognition (n = 37). We investigated the prevalence of sarcopenia in diabetes patients with and without cognitive impairment and examined the association of glucose alterations with sarcopenia. Daily glucose levels were evaluated using self-monitoring of blood glucose, and we focused on the effects of glucose fluctuations, postprandial hyperglycemia, and the frequency of hypoglycemia on sarcopenia. Diabetes patients with cognitive impairment displayed a high prevalence of sarcopenia, and glucose fluctuations were independently associated with sarcopenia, even after adjusting for glycated hemoglobin A1c (HbA1c) levels and associated factors. In particular, glucose fluctuations were significantly associated with a low muscle mass, low grip strength, and slow walking speed. Our observation suggests the importance of glucose management by considering glucose fluctuations to prevent the development of disability.
High-Throughput Line Buffer Microarchitecture for Arbitrary Sized Streaming Image Processing
Authors: Shi Runbin , Wong Justin S.J. , So Hayden K.-H.
Published: March 2019

Parallel hardware designed for image processing promotes vision-guided intelligent applications. With the advantages of high-throughput and low-latency, streaming architecture on FPGA is especially attractive to real-time image processing. Notably, many real-world applications, such as region of interest (ROI) detection, demand the ability to process images continuously at different sizes and resolutions in hardware without interruptions. FPGA is especially suitable for implementation of such flexible streaming architecture, but most existing solutions require run-time reconfiguration, and hence cannot achieve seamless image size-switching. In this paper, we propose a dynamically-programmable buffer architecture (D-SWIM) based on the Stream-Windowing Interleaved Memory (SWIM) architecture to realize image processing on FPGA for image streams at arbitrary sizes defined at run time. D-SWIM redefines the way that on-chip memory is organized and controlled, and the hardware adapts to arbitrary image size with sub-100 ns delay that ensures minimum interruptions to the image processing at a high frame rate. Compared to the prior SWIM buffer for high-throughput scenarios, D-SWIM achieved dynamic programmability with only a slight overhead on logic resource usage, but saved up to 56 % of the BRAM resource. The D-SWIM buffer achieves a max operating frequency of 329.5 MHz and reduction in power consumption by 45.7 % comparing with the SWIM scheme. Real-world image processing applications, such as 2D-Convolution and the Harris Corner Detector, have also been used to evaluate D-SWIM’s performance, where a pixel throughput of 4.5 Giga Pixel/s and 4.2 Giga Pixel/s were achieved respectively in each case. Compared to the implementation with prior streaming frameworks, the D-SWIM-based design not only realizes seamless image size-switching, but also improves hardware efficiency up to 30 × .
Statistical Analysis of the Stability of Rock Slopes
Authors: van Gent Marcel R.A. , de Almeida Ermano , Hofland Bas
Published: March 2019

Physical model tests were performed in a wave flume at Deltares with rock armoured slopes. A shallow foreshore was present. At deep water, the same wave conditions were used, but by applying different water levels, the wave loading on the rock armoured slopes increased considerably with increasing water levels. This allowed an assessment of the effects of sea level rise. Damage was measured by using digital stereo photography (DSP), which provides information on each individual stone that is displaced. Two test series were performed five times. This allowed for a statistical analysis of the damage to rock armoured slopes, which is uncommon due to the absence of statistical information based on a systematic repetition of test series. The statistical analysis demonstrates the need for taking the mean damage into account in the design of rock armoured slopes. This is important in addition to characterising the damage itself by erosion areas and erosion depths. The relation between damage parameters, such as the erosion area and erosion depth, was obtained from the tests. Besides tests with a straight slope, tests with a berm in the seaward slopes were also performed. A new method to take the so-called length effect into account is proposed to extrapolate results from physical model tests to real structures. This length effect is important, but is normally overlooked in the design of rubble mound structures. Standard deviations based on the presented model tests were used.
Asymmetric Mean Reversion in Low Liquid Markets: Evidence from BRVM
Authors: Gbenro Nathaniel , Moussa Richard Kouamé
Published: March 2019

This paper analyzes the mean reversion property on the west African stock market (in French, Bourse Régionale des Valeurs Mobilières BRVM). For this purpose, we use two daily indices: (i) the composite index (BRVMC) and (ii) the index of the 10 most liquid assets (BRVM10) collected from 3 January 2005 to 29 June 2018. We estimate an asymmetric nonlinear autoregressive model with an EGARCH innovation to account for heteroskedasticity. The results suggest the existence of a mean reversion property for both indices. The half-life time is 7 days for the composite index and 2 days for the BRVM 10 index. Furthermore, using a rolling regression technique, we show that the estimated half-life time declines slightly for the composite index.
A Validation Study of a Polymer Optical Fiber Sensor for Monitoring Lumbar Spine Movement
Authors: Kam Wern , O’Keeffe Mary , O’Sullivan Kieran , Mohammed Waleed S. , O’Keeffe Sinead , Lewis Elfed , Viphavakit Charusluk
Published: March 2019

This study aims to investigate the validity and reliability of a novel plastic optical fiber (POF) sensor, which was developed to measure the angles of flexion, extension and lateral bend at the lumbar region. The angles of flexion, extension and lateral bend for a standing position were measured simultaneously using both the novel POF sensor of this investigation and the commercial Biometrics goniometer instrument. Each movement had two steps of bending which were 10° and 20° based on inclinometer readings. The POF sensor had good intra-rater reliability (Intraclass correlation coefficient, ICC = 0.61 to 0.83). Bland–Altman plots were used to study the agreement using these two sensors. There were proportional differences and bias between the POF sensor and Biometrics goniometer, as the zero points did not lie in the percentage difference region in the Bland–Altman plots. The proportional difference between these two likely reflects the different sizes and thus, measurement regions of the two sensors. There was also strong correlation between the two sensors (r > 0.77). Hence, the POF sensor could be of potential utility in measuring lumbar range of motion (ROM) in a manner which is minimally invasive, and where discrete sections of the spine are under specific investigation.
Shrinkage Optimization in Talc- and Glass-Fiber-Reinforced Polypropylene Composites
Authors: Ryu Youngjae , Sohn Joo Seong , Kweon Byung Chul , Cha Sung Woon
Published: March 2019

The shrinkage of reinforced polymer composites in injection molding varies, depending on the properties of the reinforcing agent. Therefore, the study of optimal reinforcement conditions, to minimize shrinkage when talc and glass fibers (GF) (which are commonly used as reinforcements) are incorporated into polypropylene (PP), is required. In this study, we investigated the effect of reinforcement factors, such as reinforcement type, reinforcement content, and reinforcement particle size, on the shrinkage, and optimized these factors to minimize the shrinkage of the PP composites. We measured the shrinkage of injection-molded samples, and, based on the measured values, the optimal conditions were obtained through analysis of variance (ANOVA), the Taguchi method, and regression analysis. It was found that reinforcement type had the largest influence on shrinkage among the three factors, followed by reinforcement content. In contrast, the reinforcement size was not significant, compared to the other two factors. If the reinforcement size was set as an uncontrollable factor, the optimum condition for minimizing directional shrinkage was the incorporation of 20 wt % GF and that for differential shrinkage was the incorporation of 20 wt % talc. In addition, a shrinkage prediction method was proposed, in which two reinforcing agents were incorporated into PP, for the optimization of various dependent variables. The results of this study are expected to provide answers about which reinforcement agent should be selected and incorporated to minimize the shrinkage of PP composites.
Droplet Impact on the Super-Hydrophobic Surface with Micro-Pillar Arrays Fabricated by Hybrid Laser Ablation and Silanization Process
Authors: Xia Zhenyan , Xiao Yuhe , Yang Zhen , Li Linan , Wang Shibin , Liu Xianping , Tian Yanling
Published: March 2019

A super-hydrophobic aluminum alloy surface with decorated pillar arrays was obtained by hybrid laser ablation and further silanization process. The as-prepared surface showed a high apparent contact angle of 158.2 ± 2.0° and low sliding angle of 3 ± 1°. Surface morphologies and surface chemistry were explored to obtain insights into the generation process of super-hydrophobicity. The main objective of this current work is to investigate the maximum spreading factor of water droplets impacting on the pillar-patterned super-hydrophobic surface based on the energy conservation concept. Although many previous studies have investigated the droplet impacting behavior on flat solid surfaces, the empirical models were proposed based on a few parameters including the Reynolds number (Re), Weber number (We), as well as the Ohnesorge number (Oh). This resulted in limitations for the super-hydrophobic surfaces due to the ignorance of the geometrical parameters of the pillars and viscous energy dissipation for liquid flow within the pillar arrays. In this paper, the maximum spreading factor was deduced from the perspective of energy balance, and the predicted results were in good agreement with our experimental results with a mean error of 4.99% and standard deviation of 0.10.
Functionalized Large-Pore Mesoporous Silica Microparticles for Gefitinib and Doxorubicin Codelivery
Authors: Li Yan , Song Fangxiang , Cheng Liang , Qian Jin , Chen Qianlin
Published: March 2019

Large-pore coralline mesoporous silica microparticles (CMS) were synthesized using the triblock polymer PEG-b-PEO-b-PEG and a hydrothermal method. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed the coralline morphology of the fabricated materials. The Brunauer–Emmett–Teller (BET) method and the Barrett–Joyner–Halenda (BJH) model confirmed the existence of large pores (20 nm) and of a tremendous specific surface area (663.865 m2·g−1) and pore volume (0.365 cm3·g−1). A novel pH-sensitive multiamine-chain carboxyl-functionalized coralline mesoporous silica material (CMS–(NH)3–COOH) was obtained via a facile “grafting-to” approach. X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FT-IR) validated the effective interfacial functionalization of CMS with carboxyl and multiamine chains. The encapsulation and release behavior of the dual drug (gefitinib (GB) and doxorubicin (DOX)) was also investigated. It was found that CMS–(NH)3–COOH allows rapid encapsulation with a high loading capacity of 47.36% for GB and 26.74% for DOX. Furthermore, the release profiles reveal that CMS–(NH)3–COOH can preferably control the release of DOX and GB. The accumulative release rates of DOX and GB were 32.03% and 13.66%, respectively, at a low pH (pH 5.0), while they reduced to 8.45% and 4.83% at pH 7.4. Moreover, all of the modified silica nanoparticles exhibited a high biocompatibility with a low cytotoxicity. In particular, the cytotoxicity of both of these two drugs was remarkably reduced after being encapsulated. CMS–(NH)3–COOH@GB@DOX showed tremendously synergistic effects of the dual drug in the antiproliferation and apoptosis of A549 human cancer cells in vitro.
Turning Titanium Alloy, Grade 5 ELI, With the Implementation of High Pressure Coolant
Authors: Słodki Bogdan , Zębala Wojciech , Struzikiewicz Grzegorz
Published: March 2019

In the machining of difficult-to-cut alloys, such as titanium-based alloys, the delivery of a cutting fluid with high pressure can increase machining efficiency and improve process stability through more efficient chip breaking and removing. Proper selection of machining conditions can increase the productivity of the process while minimizing production costs. To present the influence of cutting fluid pressure and chip breaker geometry on the chip breaking process for various chip cross-sections Grade 5 ELI titanium alloy turning tests were carried out using carbide tools, H13A grade, with a -SF chip breaker geometry under the cutting fluid pressure of 70 bar. Measurements of the total cutting force components for different cutting speeds, feeds, and cutting depth in finishing turning were carried out. The analysis of the obtained chips forms and the application area of the chip breaker have been presented. It was proved that for small depth of cut (leading to small chip cross-section) the cutting fluid pressure is the main cause of the chip breakage, since the insert chip breaker does not work. On the other hand, for bigger depths of cut where the chip breaker goes in action, the cutting fluid pressure only supports this process. For medium values of depths of cut the strength of chip is high enough so that the pressure of the cutting fluid cannot cause chip breaking. A chip groove is not filled completely so the chip breaker cannot play its role.
Nanoindentation of γ-TiAl with Different Crystal Surfaces by Molecular Dynamics Simulations
Authors: Fan Xiaocui , Rui Zhiyuan , Cao Hui , Fu Rong , Feng Ruicheng , Yan Changfeng
Published: March 2019

The periodicity and density of atomic arrangement vary with the crystal orientation, which results in different deformation mechanisms and mechanical properties of γ-TiAl. In this paper, the anisotropic characteristics for γ-TiAl with (100), ( 1 ¯ 10 ) and (111) surfaces during nanoindentation at 300 K have been investigated by molecular dynamics simulations. It is found that there is no obvious pop-in event in all load-depth curves when the initial plastic deformation of γ-TiAl samples occurs, because the dislocation nucleates before the first load-drop; while a peak appears in both the unloading curves of the ( 1 ¯ 10 ) and (111) samples due to the release of energy. Stacking faults, twin boundaries and vacancies are formed in all samples; however, interstitials are formed in the (100) sample, a stacking fault tetrahedron is formed in the (111) sample; and two prismatic dislocation loops with different activities are formed in the ( 1 ¯ 10 ) and (111) samples, respectively. It is also concluded that the values of the critical load, strain energy, hardness and elastic modulus for the (111) sample are the maximum, and for the (100) sample are the minimum. Furthermore, the orientation dependence of the elastic modulus is greater than the hardness and critical load.
Effects of Withdrawal Rate on the Microstructure of Directionally Solidified GH4720Li Superalloys
Authors: Qu Jinglong , Yang Shufeng , Chen Zhengyang , Li Jingshe , Dong Anping , Gu Yu
Published: March 2019

Increasing the ingot size of GH4720Li superalloys makes it difficult to control their microstructure, and the withdrawal rate is an important factor in controlling and refining the microstructure of GH4720Li superalloys. In this study, GH4720Li superalloy samples were prepared via Bridgman-type directional solidification with different withdrawal rates. The morphology and average size of the dendrites in the stable growth zone during directional solidification in each sample, morphology and average size of the γ’ phases, and microsegregation of each alloying element were analyzed using optical microscopy, Photoshop, Image Pro Plus, field emission scanning electron microscopy, and electron probe microanalysis. Increasing the withdrawal rate significantly helped in refining the superalloy microstructure; the average secondary dendrite arm spacing decreased from 133 to 79 µm, whereas the average sizes of the γ’ phases in the dendrite arms and the interdendritic regions decreased from 1.02 and 2.15 µm to 0.69 and 1.26 µm, respectively. Moreover, the γ’ phase distribution became more uniform. The microsegregation of Al, Ti, Cr, and Co decreased with the increase in the withdrawal rate; the segregation coefficients of Al, Cr, and Co approached 1 at higher withdrawal rates, whereas that of Ti remained above 2.2 at all the withdrawal rates.
Mechanical Activation of Granulated Copper Slag and Its Influence on Hydration Heat and Compressive Strength of Blended Cement
Authors: Feng Yan , Kero Jakob , Yang Qixing , Chen Qiusong , Engström Fredrik , Samuelsson Caisa , Qi Chongchong
Published: March 2019

Mechanical activation of granulated copper slag (GCS) is carried out in the present study for the purposes of enhancing pozzolanic activity for the GCS. A vibration mill mills the GCS for 1, 2, and 3 h to produce samples with specific surface area of 0.67, 1.03 and 1.37 m2/g, respectively. The samples are used to replace 30% cement (PC) to get 3 PC-GCS binders. The hydration heat and compressive strength are measured for the binders and derivative thermogravimetric /thermogravimetric analysis (DTG/TGA), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) are used to characterize the paste samples. It is shown that cumulative heat and compressive strength at different ages of hydration and curing, respectively, are higher for the binders blending the GCS milled for a longer time. The compressive strength after 90 d of curing for the binder with the longest milling time reaches 35.7 MPa, which is higher than the strength of other binders and close to the strength value of 39.3 MPa obtained by the PC pastes. The percentage of fixed lime by the binder pastes at 28 days is correlated with the degree of pozzolanic reaction and strength development. The percentage is higher for the binder blending the GCS with longer milling time and higher specific surface area. The pastes with binders blending the GCS of specific surface area of 0.67 and 1.37 m2/g fix lime of 15.20 and 21.15%, respectively. These results together with results from X-ray diffraction (XRD), FTIR, and SEM investigations demonstrate that the mechanical activation via vibratory milling is an effective method to enhance the pozzolanic activity and the extent for cement substitution by the GCS as a suitable supplementary cementitious material (SCM).
Structural and Mechanical Characteristics of Cu50Zr43Al7 Bulk Metallic Glass Fabricated by Selective Laser Melting
Authors: Lu Xiaoyang , Nursulton Mussokulov , Du Yulei , Liao Wenhe
Published: March 2019

In this work, the structural and mechanical characteristics of Cu50Zr43Al7 bulk metallic glass (BMG) fabricated by selective laser melting (SLM) are studied and the impacts from the SLM process are clarified. Cu50Zr43Al7 alloy specimens were manufactured by the SLM method from corresponding gas-atomized amorphous powders. The as-built specimens were examined in terms of phase structure, morphologies, thermal properties and mechanical behavior. The x-ray diffraction and differential scanning calorimetry results showed that structural relaxation and partial crystallization co-exist in the as-fabricated Cu50Zr43Al7 glassy samples. The nano- and micro- hardness and the elastic modulus of the SLM-fabricated Cu50Zr43Al7 BMG were higher than CuZrAl ternary BMGs with similar compositions prepared by conventional mold casting, which can be attributed to the structural relaxation in the former sample. However, the macro compressive strength of the SLM-fabricated Cu50Zr43Al7 BMG was only 1044 MPa mainly due to its porosity. This work suggests that the SLM process induced changes in structural and mechanical properties are significant and cannot be neglected in the fabrication of BMGs.
Delannoy Numbers and Preferential Arrangements
Authors: Chen Kwang-Wu
Published: March 2019

A preferential arrangement on [ [ n ] ] = { 1 , 2 , … , n } is a ranking of the elements of [ [ n ] ] where ties are allowed. The number of preferential arrangements on [ [ n ] ] is denoted by r n . The Delannoy number D ( m , n ) is the number of lattice paths from ( 0 , 0 ) to ( m , n ) in which only east ( 1 , 0 ) , north ( 0 , 1 ) , and northeast ( 1 , 1 ) steps are allowed. We establish a symmetric identity among the numbers r n and D ( p , q ) by means of algebraic and combinatorial methods.
Mussel-Inspired Surface Functionalization of AEM for Simultaneously Improved Monovalent Anion Selectivity and Antibacterial Property
Authors: Zheng Zhihao , Bruggen Bart , Xiao Pang , Shen Jiangnan , Ruan Huimin , Liao Junbin , Gao Congjie , Bruggen Bart , Shen Jiangnan
Published: March 2019

A facile membrane surface modification process for improving permselectivity and antimicrobial property was proposed. A polydopamine (PDA) coating was firstly fabricated on pristine anion exchange membrane (AEM), followed by in situ reduction of Ag without adding any extra reductant. Finally, 2,5-diaminobenzene sulfonic acid (DSA) was grafted onto PDA layer via Michael addition reaction. The as-prepared AEM exhibited improved permselectivity (from 0.60 to 1.43) and effective inhibition of bacterial growth. In addition, the result of the long-term (90-h continuous electrodialysis) test expressed the excellent durability of the modified layer on membrane surface, because the concentration of Cl− and SO42− in diluted chamber fluctuated ~0.024 and 0.030 mol·L−1 with no distinct decline. The method described in this work makes the full use of multifunctional PDA layer (polymer-like coating, in situ reduction and post-organic reaction), and a rational design of functional AEM was established for better practical application.
Influence of Hydraulic Pressure on Performance Deterioration of Direct Contact Membrane Distillation (DCMD) Process
Authors: Park Seung-Min , Lee Sangho
Published: March 2019

Direct contact membrane distillation (DCMD) is a membrane distillation (MD) configuration where feed and distillate directly contact with a hydrophobic membrane. Depending on its operating conditions, the hydraulic pressures of the feed and distillate may be different, leading to adverse effects on the performance of the DCMD process. Nevertheless, little information is available on how hydraulic pressure affects the efficiency of DCMD. Accordingly, this paper investigates the effect of external hydraulic pressure on the process efficiency of DCMD. Gas permeabilities of MD membranes were measured to analyze the effect of membrane compaction by external pressure. Mass transfer coefficients were calculated using experimental data to quantitatively explain the pressure effect. Experiments were also carried out using a laboratory-scale DCMD set-up. After applying the pressure, the cross-sections and surfaces of the membranes were examined using a scanning electron microscope (SEM). Results showed that the membrane structural parameters such as porosity and thickness were changed under relatively high pressure conditions (>30 kPa), leading to reduction in flux. The mass transfer coefficients were also significantly influenced by the hydraulic pressure. Moreover, local wetting of the membranes were observed even below the liquid entry pressure (LEP), which decreased the rejection of salts. These results suggest that the control of hydraulic pressure is important for efficient operation of DCMD process.
Influence of Mo Additions on the Mechanical Properties of Cast Duplex Stainless Steels before and after Thermal Aging
Authors: Li Shilei , Wang Yanli , Wang Xitao
Published: March 2019

The influence of Mo additions on the mechanical properties of cast duplex stainless steel (CDSS) before and after thermal aging was investigated using a series of model alloys with different Mo contents ranging from 0 to 1.75 wt%. By increasing Mo content, the content, morphology, and distribution of ferrite in CDSS change significantly. After thermal aging at 400 °C for 3000 h, the impact properties of all CDSS specimens obviously decline, and their hardness values in ferrite significantly increase. The impact energies of the aged CDSS decline, and the proportion of cleavage features significantly increases with Mo content increasing. The spinodal decomposition kinetics in ferrite is not significantly affected by the Mo contents. High content and interconnected ferrite will lead to the severe embrittlement in CDSS after thermal aging.
Sensitivity Analysis of Tool Wear in Drilling of Titanium Aluminides
Authors: Beranoagirre Aitor , Urbikain Gorka , Marticorena Raúl , Bustillo Andrés , López de Lacalle Luis Norberto
Published: March 2019

In the aerospace industry, a large number of holes need to be drilled to mechanically connect the components of aircraft engines. The working conditions for such components demand a good response of their mechanical properties at high temperatures. The new gamma TiAl are in the transition between the 2nd and 3rd generation, and several applications are proposed for that sector. Thus, NASA is proposing the use of the alloys in the Revolutionary Turbine Accelerator/Turbine-Based Combined Cycle (RTA/TBCC) Program for the next-generation launch vehicle, with gamma TiAl as a potential compressor and structural material. However, the information and datasets available regarding cutting performance in titanium aluminides are relatively scarce. So, a considerable part of the current research efforts in this field is dedicated to process optimization of cutting parameters and tool geometries. The present work is framed in the study of wear when machining holes in these difficult-to-cut alloys. In particular, the work presents the results from drilling tests on three types of gamma TiAl alloys, extruded MoCuSi, ingot MoCuSi, and TNB type, to define an optimal set of cutting parameters. Maintaining uniform, gradual wear is key to avoiding tool breakage and enabling good hole dimensional accuracy. So, this paper proposes a model based on ANOVA analysis to identify the relationships between cutting conditions and resulting wear and estimate tool life. The best cutting parameters were found at vc = 10–15 m/min and fn = 0.025 mm/rev.
Dynamic Recrystallization and Hot-Working Characteristics of Ni-Based Alloy with Different Tungsten Content
Authors: Gong Zhihua , Bao Hansheng , Yang Gang
Published: March 2019

The hot deformation behavior of the GY200 Ni-based alloys with different tungsten (W) content were investigated by means of hot compression tests, microscopic observations, and processing maps at temperatures between 950 °C and 1200 °C, strain rate between 0.01 s−1 and 10 s−1 with strain of 0.9. The hyperbolic-sine type constitutive equations were established between peaks tress and deformation conditions through Z parameters, and for alloys with higher W content results in higher activation energy and complete recrystallization temperature. The hot-working maps were exploited based on the experimental data. The hot-working maps showed that the instability zone extended with increasing W content. The stable domain of alloys are located in the temperature range between 1025 °C and 1200 °C and strain rate range between 0.01 s−1 and 1 s−1, dominated by the dynamic recrystallization (DRX) microstructural evolution, suited for hot deformation. The cracking on the surface of the sample compressed at 950 °C was resulted from the tensile stress, while the fracture of the sample compressed at 1200 °C was triggered by the melting of grain boundaries.
Hydrophobicity Influence on Swimming Performance of Magnetically Driven Miniature Helical Swimmers
Authors: Ye Chengwei , Liu Jia , Wu Xinyu , Wang Ben , Zhang Li , Zheng Yuanyi , Xu Tiantian
Published: March 2019

Helical microswimmers have been involved in a wide variety of applications, ranging from in vivo tasks such as targeted drug delivery to in vitro tasks such as transporting micro objects. Over the past decades, a number of studies have been established on the swimming performance of helical microswimmers and geometrical factors influencing their swimming performance. However, limited studies have focused on the influence of the hydrophobicity of swimmers’ surface on their swimming performance. In this paper, we first demonstrated through theoretical analysis that the hydrophobicity of swimmer’s surface material of the swimmer does affect its swimming performance: the swimmer with more hydrophobic surface is exerted less friction drag torque, and should therefore exhibit a higher step-out frequency, indicating that the swimmer with more hydrophobic surface should have better swimming performance. Then a series of experiments were conducted to verify the theoretical analysis. As a result, the main contribution of this paper is to demonstrate that one potential approach to improve the helical microswimmers’ swimming performance could be making its surface more hydrophobic.
The Moroccan Massive Sulphide Deposits: Evidence for a Polyphase Mineralization
Authors: Essaifi Abderrahim , Goodenough Kathryn , Tornos Fernando , Outigua Abdelhak , Ouadjou Abdelmalek , Maacha Lhou
Published: March 2019

This work provides an overview of the geological, geochemical, and metallogenic data available up to date on the Moroccan massive sulphide deposits, including some new results, and then discusses the evidences for the epigenetic and syngenetic hypotheses. All of the ore deposits are located within a crustal block located at the intersection between two major shear zones and are characterized by a sustained and long-lived magmatic activity. The ore deposits are located within second-order shear zones, which played an important role in controlling the geometry of the mineralization. The mineralization lacks the unequivocal textural and structural features that are indicative of a sedimentary or diagenetic origin, and a syntectonic to late-tectonic pyrite-rich assemblage is superimposed on an earlier, pretectonic to syntectonic pyrrhotite-rich mineralization. Each deposit has a distinctive pyrrhotite sulfur isotopic signature, while the sulfur isotopic signature of pyrite is similar in all deposits. Lead isotopes suggest a shift from a magmatic source during the pyrrhotite-rich mineralization to a source that is inherited from the host shales during the pyrite-rich mineralization. The O/H isotopic signatures record a predominance of fluids of metamorphic derivation. These results are consistent with a model in which an earlier pyrrhotite-rich mineralization, which formed during transtension, was deformed and then remobilized to pyrite-rich mineralization during transpression.
LA-ICP-MS Trace-Element Analysis of Pyrite from the Huanxiangwa Gold Deposit, Xiong’ershan District, China: Implications for Ore Genesis
Authors: Gao Fuping , Du Yangsong , Pang Zhenshan , Du Yilun , Xin Fengpei , Xie Jinsong
Published: March 2019

The Huanxiangwa deposit is a major gold deposit in the Xiong’ershan district, which is the third-largest gold-producing district in China. Pyrites from the Huanxiangwa deposit were investigated using ore microscopy and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). Pyrite is the dominant Au-bearing mineral in the Huanxiangwa deposit and can be divided into two types: medium- to fine-grained subhedral-anhedral pyrite (Py1) disseminated in altered rocks and coarse-grained subhedral-euhedral pyrite (Py2) hosted in auriferous quartz veins. LA-ICP-MS time-resolved depth profiles show that invisible gold occurs primarily as solid solution or as homogeneously distributed nanoparticles of native gold, electrum, or Au-Ag-Te minerals in Py1, whereas it is present mainly as nano- to submicron-sized inclusions of complex Au-Ag-Cu-Pb-Zn domains in Py2. The presented data indicate that the Huanxiangwa deposit resulted from two episodes of hydrothermal mineralization associated with two distinct source reservoirs. The first episode of mineralization was linked to the dehydration of deep-seated mafic-ultramafic metamorphic rock during the Triassic collision of the North China Craton with the Yangtze Craton. The second episode of mineralization was related to hydrothermal activity resulting from Early Cretaceous I-type granitic magmatism.
Fossilised Biomolecules and Biomarkers in Carbonate Concretions from Konservat-Lagerstätten
Authors: Grice Kliti , Holman Alex I. , Plet Chloe , Tripp Madison
Published: March 2019

In the vast majority of fossils, the organic matter is degraded with only an impression or cast of the organism remaining. In rare cases, ideal burial conditions result in a rapid fossilisation with an exceptional preservation of soft tissues and occasionally organic matter. Such deposits are known as Lagerstätten and have been found throughout the geological record. Exceptional preservation is often associated with finely crystalline quartz (e.g., cherts), fine sediments (e.g., muds) or volcanic ashes. Other mechanisms include burial in anoxic/euxinic sediments and in the absence of turbidity or scavenging. Exceptional preservation can also occur when an organism is encapsulated in carbonate cement, forming a concretion. This mechanism involves complex microbial processes, resulting in a supersaturation in carbonate, with microbial sulfate reduction and methane cycling the most commonly suggested processes. In addition, conditions of photic zone euxinia are often found to occur during concretion formation in marine environments. Concretions are ideal for the study of ancient and long-extinct organisms, through both imaging techniques and biomolecular approaches. These studies have provided valuable insights into the evolution of organisms and their environments through the Phanerozoic and have contributed to increasing interest in fields including chemotaxonomy, palaeobiology, palaeoecology and palaeophysiology.
Optimization of the Split-Spinach Aptamer for Monitoring Nanoparticle Assembly Involving Multiple Contiguous RNAs
Authors: O’Hara Jack M. , Marashi Dylan , Morton Sean , Jaeger Luc , Grabow Wade W.
Published: March 2019

The fact that structural RNA motifs can direct RNAs to fold and self-assemble into predictable pre-defined structures is an attractive quality and driving force for RNA’s use in nanotechnology. RNA’s recognized diversity concerning cellular and synthetically selected functionalities, however, help explain why it continues to draw attention for new nano-applications. Herein, we report the modification of a bifurcated reporter system based on the previously documented Spinach aptamer/DFHBI fluorophore pair that affords the ability to confirm the assembly of contiguous RNA strands within the context of the previously reported multi-stranded RNA nanoring. Exploration of the sequence space associated with the base pairs flanking the aptamer core demonstrate that fluorescent feedback can be optimized to minimize the fluorescence associated with partially-assembled RNA nanorings. Finally, we demonstrate that the aptamer-integrated nanoring is capable of assembling directly from transcribed DNA in one pot.
Miso (Fermented Soybean Paste) Suppresses Visceral Fat Accumulation in Mice, Especially in Combination with Exercise
Authors: Okouchi Ran , Sakanoi Yuto , Tsuduki Tsuyoshi
Published: March 2019

We investigated whether the difference in miso consumption between the Japanese diets of 1975 and 2010 has influenced the observed increase in diet-induced obesity. To recreate the 2010 and 1975 Japanese high-fat diets with the corresponding proportions of miso, freeze-dried miso was added to high-fat mouse feed at 1.6% and 2.6%, respectively. When 5-week-old male Institute of Cancer Research (ICR) mice were provided each of these diets ad libitum for 8 weeks, it was found that the white adipose tissue weight and adipocyte area were lower in mice receiving the 1975 diet than in those receiving the 2010 diet. Therefore, high miso consumption is one reason why the 1975 Japanese diet tended to not lead to obesity. Next, the combined effects of treadmill exercise and miso consumption were investigated. The mice were divided into three groups, which were provided either a high-fat diet (group C), a high-fat diet with exercise (group C + E), or a miso-supplemented high-fat diet with exercise (group M + E) for 8 weeks. In this experiment, the white adipose tissue weight and adipocyte area in group M + E were lower than in group C. When the mRNA expression of lipid metabolism-associated genes in adipose tissue was measured, we found that expression of Hsl (lipase, hormone sensitive), which is involved in lipolysis, and Pparγ (peroxisome proliferator activated receptor gamma), which regulates adipocyte differentiation upstream of Hsl, was increased in group M + E. These results clearly demonstrated that lipid accumulation in the adipose tissues is suppressed by miso consumption in combination with exercise.
Effects of Virgin Olive Oils Differing in Their Bioactive Compound Contents on Biomarkers of Oxidative Stress and Inflammation in Healthy Adults: A Randomized Double-Blind Controlled Trial
Authors: Sanchez-Rodriguez Estefania , Biel-Glesson Sara , Fernandez-Navarro Jose R. , Calleja Miguel A. , Espejo-Calvo Juan A. , Gil-Extremera Blas , de la Torre Rafael , Fito Montserrat , Covas Maria-Isabel , Vilchez Pedro , Alche Juan de Dios , Martinez de Victoria Emilio , Gil Angel , Mesa Maria D.
Published: March 2019

A regular consumption of virgin olive oil (VOO) is associated with a reduced risk of cardiovascular disease. We aimed to assess whether the raw intake of an optimized VOO (OVOO, 490 ppm of phenolic compounds and 86 ppm of triterpenes), and a functional olive oil (FOO, 487 ppm of phenolic compounds and enriched with 389 ppm of triterpenes) supplementation (30 mL per day) during three weeks would provide additional health benefits to those produced by a standard VOO (124 ppm of phenolic compounds and 86 ppm of triterpenes) on oxidative and inflammatory biomarkers. Fifty-one healthy adults participated in a randomized, crossover, and controlled study. Urinary 8-hidroxy-2′-deoxyguanosine, plasma interleukin-8 (IL-8), and tumor necrosis factor α (TNF- α) concentrations were lower after the intervention with the FOO than after the OVOO (p = 0.033, p = 0.011 and p = 0.020, respectively). In addition, IL-8 was lower after the intervention with FOO than after VOO intervention (p = 0.002). This study provides a first level of evidence on the in vivo health benefits of olive oil triterpenes (oleanolic and maslinic acids) in healthy humans, decreasing DNA oxidation and plasma inflammatory biomarkers. The trial was registered in ClinicalTrials.gov ID: NCT02520739.