bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experimental Design of AL2O3/MWCNT/HDPE Hybrid Nanocomposites for Hip Joint Replacement
Authors: Dabees Sameh , Ahmed Bahaa , Sanad Mohamed , Elshalakny Abou Bakr 
Published: April 2020

Abstract
A hip fracture can be considered a major health issue facing the elderly fraction of humans. The loads exploited by the lower limbs are very acute and severe; in the femur, they can be several folds higher than the whole weight of the body. Mechanical properties like strength and hardness are challenging parameters which control the selection of the joint. In this research work, a modification has been performed by adding multi-layer carbon nanotubes to the High-density polyethylene thermoplastic polymer together with alumina. Prepared material well physiochemically characterized to check the morphology and the structure. Thermal gravimetric analysis (TGA) dedicates that the percentage of crystallization has been increased to 6% after adding Multi-wall carbon nanotubes (MWCNT)to the polymer. According to mechanical properties results, MWCNTs successfully increase in young’s module and hardness of the polymer. Optimization of the materials ration has been done and it has been found that hybrid composite with structure (2.4% AL 2 O 3 and 0.6% MWCNT) obtains high mechanical properties compared to other ratios with 3% MWCNTs and 5% MWCNTs. Also, moisture absorption decreased to 90% at with 5% MWCNT ratio. Experimental results of MTT assay of a normal human epithelial cell line (1- BJ1) over AL 2 O 3 /MWCNT@ HDPE showed a low value of cytotoxic activity, which proves that it is proper for medical use.AL 2 O 3 /MWCNT@HDPE composite showed promising results for further studies of artificial joints.
Numerical simulation of the influence of water vapor on gas explosions in a high-pressure environment
Authors: Zou Li , Yi Xin , Li Haitao , Liu Xixi , Deng Jun 
Published: April 2020

Abstract

Gas explosion seriously threaten the employees security and restrict the safe production of coal mines. Therefore, it is particularly essential to investigate the prevention and control of gas explosions. In this study, a two-dimensional numerical model of a spherical explosion tank was developed to explore the effects of water vapor on gas explosions in a high-pressure environment. Explosion parameters of 10% gas, 1 MPa pressure, and water vapor contents varying from 0% to 8% were simulated using FLUENT software. The results show that the maximum explosion pressure and temperature of the premixed gas gradually decrease with increasing water vapor content, i.e., when the water vapor content is increased from 0% to 8%, the maximum explosion pressure and temperature of the gas mixture decreases from 2.52 MPa and 2092 K under dry conditions to 1.62 MPa and 1714 K with 8% water vapor. The attenuation amplitude is also reduced upon the addition of steam. Water vapor in premixed gas therefore plays a vital role in suppressing gas explosions.
Close up to the Surface: Reflections on a Preliminary Forensic Study of Four Chinese Bronze Mirrors from a Hong Kong Private Collection
Authors: Liang Jiafang , Parker Quentin 
Published: April 2020

Abstract

This article presents an objective, forensic study undertaken within the HKU Architectural Conservation Laboratory (ACLab) conducted on 4 very different bronze mirrors from a private collection. They nominally cover the period from the Warring States (475-221BC), Han (206 BC to 220AD) and later Song (960-1279AD) dynasties. Comprehensive, non-invasive, analytical methods and techniques were applied in this endeavour, including microscopic observation of tool marks, patina, corrosion and any residual archaeological evidence. Ultraviolet radiation examination as well as pXRF analysis of the bronze alloy, corrosion products and any earthen encrustations were conducted. The combined results have revealed key alloy information of those four mirrors along with surface patina morphology and details of the corrosion products and residual surface archaeology. Three of the mirrors from the Warring States, late Han, and Song dynasties appear to be genuine artifacts based on the available forensic evidence presented. One other nominally also from the Warring States period has some indications of veracity but requires further study. The two Warring States mirrors appear to have been heavily cleaned, polished and treated with abrasives in modern times. This study shows that use of modern technologies for forensic investigation and evaluation of bronze mirrors that otherwise lack verifiable background information as to their origin can be a useful adjunct to expert appraisal.
Rapid Optimisation of Cellulolytic Enzymes Ratios in Saccharomyces Cerevisiae using in Vitro SCRaMbLE
Authors: Wightman Elizabeth L. I. , Kroukamp Heinrich , Pretorius Isak S. , Paulsen Ian T. , Nevalainen Helena K. M. 
Published: April 2020

Abstract
Background For the economic production of biofuels and other valuable products from lignocellulosic waste material, a consolidated bioprocessing (CBP) organism is required. With efficient fermentation capability and attractive industrial qualities, Saccharomyces cerevisiae is a preferred candidate and has been engineered to produce enzymes that hydrolyze cellulosic biomass. Efficient cellulose hydrolysis requires the synergistic action of several enzymes; with the optimum combined activity ratio dependent on the composition of the substrate. Results In vitro SCRaMbLE generated a library of plasmids containing different ratios of a β-glucosidase gene ( CEL3A ) from Saccharomycopsis fibuligera and an endoglucanase gene ( CEL5A ) from Trichoderma reesei . S. cerevisiae , transformed with the plasmid library, displayed a range of individual enzyme activities and synergistic capabilities. Furthermore, we show for the first time that BPNPG5 (Megazyme®) is a suitable substrate to determine synergistic Cel3A and Cel5A action and an accurate predictive model for this synergistic action was devised. Strains with highest BPNPG5 activity had an average CEL3A and CEL5A gene cassette copy number of 1.3 ± 0.6 and 0.8 ± 0.2 respectively (ratio of 1.6:1). Conclusions Here we describe a synthetic biology approach to rapidly optimize gene copy numbers to achieve efficient synergistic substrate hydrolysis. This study demonstrates how in vitro SCRaMbLE can be applied to rapidly combine gene constructs in various ratios to allow screening of synergistic enzyme activities for efficient substrate hydrolysis.
Neural-Fuzzy-Based Adaptive Sliding Mode Automatic Steering Control of Vision-based Unmanned Electric Vehicles
Authors: Guo Jinghua , Li Keqiang , Fan Jinjin , Luo Yugong , Wang Jingyao 
Published: April 2020

Abstract
This paper presents a novel neural-fuzzy-based adaptive sliding mode automatic steering control strategy to improve the driving performance of vision-based unmanned electric vehicles with time-varying and uncertain parameters. Primarily, the kinematic and dynamic models which accurately express the steering behaviors of vehicles are constructed, and in which the relationship between the look-ahead time and vehicle velocity is revealed. Then, in order to overcome the external disturbances, parametric uncertainties and time-varying features of vehicles, a neural-fuzzy-based adaptive sliding mode automatic steering controller is proposed to surprise the lateral dynamic behavior of unmanned electric vehicles, which includes an equivalent control law and an adaptive variable structure control law. In this novel automatic steering control system of vehicles, a neural network system is utilized for approximating the switching control gain of variable structure control law, and a fuzzy inference system is presented to adjust the thickness of boundary layer in real-time. The stability of closed-loop neural-fuzzy-based adaptive sliding mode automatic steering control system is proven using the Lyapunov theory. Finally, The results illustrate that the presented control scheme has the excellent properties in term of error convergence and robustness.
Multi-objective optimization in titanium powder mixed electrical discharge machining process parameters for die steels
Authors: Huu Phan Nguyen 
Published: April 2020

Abstract
In this paper, we propose a viable optimal solution for achieving multi-objective optimization in powder mixed electrical discharge machining (PMEDM) process parameters, using titanium powder. Taguchi–AHP–Deng’s method is used to solve the multi-criteria decision making (MCDM) problem for this technology. The process parameters selected are workpiece material, electrode material, electrode polarity, pulse on time (Ton), pulse off time (Tof), current (I), and powder concentration. The material removal rate (MRR), tool wear rate (TWR), surface roughness (SR), hardness surface (HV), and white layer thickness (WLT) were determined simultaneously. The results showed that the optimal material for the workpiece is SKD11 die steel; the optimal material for the electrode is Gr; and the polarity of the electrode should be positive. The optimal values for the other process parameters were determined to be Ton = 20 μs, Tof = 57 μs, and I = 8 A, and that for the powder concentration was 10 g/l. The quality criteria for the optimal process parameters were determined to be MRR = 59.669 mm3/min, TWR = 14.073 mm3/min, SR = 4.45 μm, HV = 907.64 HV and WLT = 8.56 μm. The results were verified through experiments, which revealed a good accuracy (error ≈ 11.67%). The white-layer formation on the machined surface was reduced using titanium powder-based PMEDM for die steel at the optimal conditions. The results showed that Deng’s similarity method is the most suitable for MCDM in PMEDM using titanium powder.
Development and Verification of an Immune-Related Gene Pairs Prognostic Signature in Ovarian Cancer
Authors: Wang Shengke , Zhang Bao , Nie Xiaocui , Miao Xinxin , Wang Shuo , Li Jing 
Published: April 2020

Abstract

Background: Ovarian cancer (OV) is the most common gynecological cancer and is a major cause of cancer-related death among women worldwide. Immunotherapy has recently been of great interest, and it has been proven to be an effective treatment strategy. For this reason, the work here attempts to produce a prognostic immune-related gene pair (IRGP) signature to estimate OV patient survival. Methods: The Gene Expression Omnibus (GEO) and the Cancer Genome Atlas (TCGA) databases provided the genetic expression profiles and clinical data of OV patients, whose samples were divided into training, validation, and testing sets. The InnateDB database and the least absolute shrinkage and selection operator (LASSO) regression model, were used to build an IRGP signature. The functional enrichment analysis was performed to investigate the biological activities of IRGPs. Then, the correlation between risk scores and clinicopathological parameters was further analyzed. Finally, we compared our signature and four existing signatures for OV. Results: We first identified a 17-IRGP signature significantly associated with survival based on LASSO regression model. The average area under the curve (AUC) values of the training, validation, and all TCGA sets were 0.869, 0.712, and 0.778, respectively. In addition, the average AUC of the independent testing set was 0.73. The 17-IRGP signature noticeably split patients into high- and low-risk groups with different prognostic outcomes. As suggested by a functional study, some biological pathways, including the Toll-like receptor and chemokine signaling pathways, were significantly negatively correlated with risk scores; however, pathways such as the p53 and apoptosis signaling pathways had a positive correlation. Moreover, tumor stage III, IV, grade G1/G2, and G3/G4 samples had significant differences in risk scores. High- and low-risk groups of the four TCGA OV subtypes also had significant prognostic differences. When compared with four other signatures for OV, our 17-IRGP signature had better prognostic prediction performance. Conclusions: An effective 17-IRGP signature was produced to predict prognostic outcomes in OV, providing new insights into immunological biomarkers.
Co-encapsulation of HNF4α Overexpressing UMSCs and Human Primary Hepatocytes Ameliorates Mouse Acute Liver Failure
Authors: Kong Defu , Xu Huiming , Chen Mo , Yu Yeping , Qian Yongbing , Qin Tian , Tong Ying , Xia Qiang , Hang Hualian 
Published: April 2020

Abstract
Background: Acute liver failure (ALF) is a complicated condition that is characterized by global hepatocyte death and often requires immediate liver transplantation. However, this therapy is limited by shortage of donor organs. Mesenchymal stem cells (MSCs) and hepatocytes are two attractive sources of cell-based therapies to treat ALF. The combined transplantation of hepatocytes and MSCs is considered to be more effective for the treatment of ALF than single-cell transplantation. We have previously demonstrated that HNF4α-overexpressing human umbilical cord MSCs (HNF4α-UMSCs) promoted the expression of hepatic-specific genes. In addition, microencapsulation allows exchange of nutrients, forming a protective barrier to the transplanted cells. Moreover, encapsulation of hepatocytes improves the viability and synthetic ability of hepatocytes and circumvents immune rejection. This study aimed to investigate the therapeutic effect of microencapsulation of hepatocytes and HNF4α-UMSCs in ALF mice.Methods: Human hepatocytes and UMSCs were obtained from liver and umbilical cord separately, followed by co-encapsulation and transplantation into mice by intraperitoneal injection. LPS/D-gal was used to induce ALF by intraperitoneal injection 24 h after transplantation. In addition, Raw 264.7cells (a macrophage cell line) were used to elucidate the effect of HNF4α-UMSCs-hepatocyte microcapsules on polarization of macrophages. The protein chip of conditioned mediums (CMs) of UMSCs and HNF4α-UMSCs were used to define the important paracrine factors and investigate the possible mechanism of HNF4α-UMSCs for the treatment of ALF in mice.Results: HNF4α-UMSCs can enhance the function of primary hepatocytes in alginate–poly-L-lysine–alginate (APA) microcapsules. The co-encapsulation of both HNF4α-UMSCs and hepatocytes achieved better therapeutic response in ALF mice by promoting M2 macrophage polarization and inflammatory resolution effect mainly modulated by the paracrine factor HB-EGF from HNF4α-UMSCs.Conclusions: The present study confirms that the co-encapsulation of HNF4α-UMSC and hepatocytes could exert an efficient effect on ALF mainly by HB-EGF and provides a novel therapeutic strategy for the treatment of ALF.
Eating habits and physical activity in working adults: a formative research
Authors: Badillo-Camacho N , Torres-Castro S , Bernal-Orozco MF , Torres-Carrillo NM , Altamirano-Martínez M , Rodríguez-Rocha NP , Cordero-Muñoz AY , Ojeda Gabriela Macedo 
Published: April 2020

Abstract
Background: Eating habits and physical activity are important factors for the development and prevention of non-communicable diseases. Therefore, the objective of this study was to analyse the beliefs, behaviours, and experiences of dietary and physical activity habits based on the constructs of the Social Cognitive Theory (SCT). Methods: An exploratory study with a qualitative methodology and a phenomenological study design was conducted using focus groups, in-depth interviews, and indirect non-participatory observation. The sessions were audio-recorded and transcribed with prior written informed consent. Data analysis was performed using a hybrid approach.Results: Workers reported that they do not eat vegetables or fruits daily; however, the consumption of fast food and sugary drinks was frequent. Participants’ behaviour is influenced by environmental factors such as reinforcements (economic bonus and company meetups & events), barriers (workplace policies) and facilitators (availability of drinking water, free tortillas , dining rooms, and recreational areas); and personal factors, such as low self-control when when choosing foods from the grains group (e.g. Mexican pastries, noodles and breads), and emotional confrontation (e.g. few workers try to use strategies to confront their emotions and avoid them from affecting their eating and physical activity). On the other hand, participants indicated not feeling capable of eating specific foods due to their taste, for example vegetables, and doing physical activity due to factors such as time. Finally, other key elements influencing workers’ behaviours were observational learning (participants eating behaviour and physical activity are influenced by their coworkers and family’s behaviours), social support (coworkers and family) and outcome expectations (participants’ hoping to improve their health by eating healthy and physical activity behaviours).Conclusions: Workers’s eating behaviour and physical activity could be modified if different influencing factors are simultaneously addressed. These findings will contribute to the development of worksite health programs, based on the SCT, to address the key factors that could improve workers’ eating behaviours and physical activity. Keywords: Eating habits, physical activity, adults, workers, workplace programs, qualitative research, Social Cognitive Theory.
Measurement of CSF core Alzheimer Disease biomarkers for routine clinical diagnosis: do fresh vs frozen samples differ?
Authors: Bellomo Giovanni , Cataldi Samuela , Paciotti Silvia , Paoletti Federico Paolini , Chiasserini Davide , Parnetti Lucilla 
Published: April 2020

Abstract
Background: cerebrospinal fluid (CSF) amyloid-beta (Aβ) 42/40 ratio, threonine-181-phosphorylated-tau (p-tau) and total-tau (t-tau) represent core biomarkers of Alzheimer Disease (AD). The recent availability of automated platforms has represented a significant achievement for reducing the pre-analytical variability of these determinations in clinical setting. With respect to classical manual ELISAs, these platforms give us also the possibility to measure any single sample and to get the result within approximately 30 min. So far, reference values have been calculated from measurements obtained in frozen samples. In this work, we wanted to check if the values obtained in fresh CSF samples differ from those obtained in frozen samples, since this issue is mandatory in routine diagnostic work.Methods: fifty-eight consecutive CSF samples have been analyzed immediately after lumbar puncture and after one-month deep freezing (-80°C). As automated platform we used Lumipulse G600-II (Fujirebio Inc.). Both the fresh and the frozen aliquots were analyzed in their storage tubes.Results: in fresh samples, a mean increase of Aβ40 (6%), Aβ42 (2%), p-tau (2%) and t-tau (4%) was observed as compared to frozen samples, whereas a slight decrease was observed for Aβ42/Aβ40 ratio (4%), due to the higher deviation of Aβ40 in fresh samples compared to Aβ42.These differences are significant for Aβ40, Aβ42/Aβ40 ratio, p-tau and t-tau. Nevertheless, Aβ42/Aβ40 ratio showed a lower variability (smaller standard deviation of relative differences) with respect to Aβ42. With respect to the AD profile according to the A/T/(N) criteria for AD diagnosis, no significant changes in classification were observed when comparing results obtained in fresh vs frozen samples.Conclusions: small but significant differences have been found for Aβ40, Aβ42/Aβ40 ratio, p-tau and t-tau in fresh vs frozen samples. Importantly, these differences did not imply a modification in the A/T/(N) classification system. In order to know if different cut-offs for fresh and frozen samples are required, larger, multi-center investigations are needed.
Real-world efficacy of the impulse oscillometry system for the management of bronchial asthma
Authors: Sugawara Hiroyuki , Saito Atsushi , Yokoyama Saori , Tsunematsu Kazunori , Chiba Hirofumi , Takahashi Hiroki 
Published: April 2020

Abstract
Background: Bronchial asthma (BA) has different phenotypes, and it requires a clinically effective subtype classification system. The impulse oscillometry system (IOS) is a novel device used in respiratory functional tests. However, its efficacy has not been validated. Therefore, this study aimed to assess the relationship between BA and the IOS parameters, and the difference in the therapeutic effects of inhaled corticosteroids (ICSs) among the subtype classifications was evaluated using the IOS.Methods: The following ICSs were randomly prescribed in daily medical care: coarse-particle ICS (fluticasone propionate [FP]), fine-particle ICS (mometasone furoate [MF]), and moderate-particle ICS (budesonide [BUD]). The treatment effects were assessed using the Asthma Health Questionnaire (AHQ) and the Asthma Control Test (ACT), and were compared among the three subtypes (central predominant, peripheral predominant, and resistless) using the IOS.Results: In the central predominant type, the AHQ score of the MF group was significantly higher than that of the FP and BUD groups. In the peripheral predominant type, the MF group had a significantly lower AHQ than the FP group. In the resistless type, no significant difference was observed in the AHQ scores among the three groups. Moreover, similar results were obtained in the study using ACTConclusions: A strong association was observed between IOS subtype classification and ICS particle size in terms of therapeutic efficiency in BA. This result indicates that the ICS particle size must be identified using the IOS subtype classification before treatment.
Temporal dynamics of the fecal microbiota in veal calves in a 6-month field trial
Authors: Massot Méril , Haenni Marisa , Nguyen Thu Thuy , Madec Jean-Yves , Mentré France , Denamur Erick 
Published: April 2020

Abstract
BackgroundMaintaining a gut homeostasis during calf growth remains a challenge in the dairy industry, as enteric infections due to opportunistic pathogens are a main burden. Because of their high sensitivity to infections, calves are frequently treated with antibiotics, and the impact on the maturation of their microbiota is largely unknown. We conducted a field study on 45 calves distributed in three veal farms to follow the longitudinal dynamics of their fecal microbiota and of their commensal E. coli populations. We quantified the impact of collective antibiotic treatments received in a 15-days window before samplings on the microbiota diversity and the quantity of E. coli. In two farms, we also searched for associations between recommended daily doses of milk powder and bacterial abundances. ResultsThe time had a significant effect on the microbiota composition. A high heterogeneity was observed between calves after their arrival in farms, followed by an increase in similarity over time, which was concomitant with a decrease in proportion of newly detected OTUs in the samples. A switch of dominant genera, such as that of Lactobacillus and Bifidobacterium at early stages to Prevotella and Alloprevotella were observed as the calves aged. The Shannon index sharply increased during the first month, and then its increase slowed-down, and even stagnated in one farm. Calves receiving antibiotics had a less diverse microbiota and a reduced number of E. coli during the treatment or in the fifteen days following it compared to calves not exposed, although these effects were limited. We found moderate to strong positive associations between the dose of milk powder and the relative abundance of several genera, and also with the absolute number of E. coli.ConclusionsMassive and continuous bacterial successions happen during the maturation of the fecal microbiota of veal calves, resulting in major changes in the diversity and taxonomic composition. This observational study suggests that in such dynamical ecosystems, administration of collective antibiotic treatments results in a limited reduction of diversity and of the size of E. coli population, and highlights the need of additional work to fully understand the impact of antibiotic treatments.