bluuebunny/crossref_metadata_2025 huggingface dataset:
Diabetes Mellitus and Vitamin D Deficiency: Comparable Effect on Survival and a Deadly Association after a Myocardial Infarction
Authors: Aleksova Aneta , Ferro Federico , Gagno Giulia , Padoan Laura , Saro Riccardo , Santon Daniela , Stenner Elisabetta , Barbati Giulia , Cappelletto Chiara , Rossi Maddalena , Beltrami Antonio Paolo , Sinagra Gianfranco
Published: July 2020

Survivors after a myocardial infarction (MI), especially those with diabetes mellitus (DM), remain at high risk of further events. Identifying and treating factors that may influence survival may open new therapeutic strategies. We assessed the impact on prognosis of DM and hypovitaminosis D (hypovitD), alone or combined. In this prospective, observational study, 1081 patients were enrolled surviving an MI and divided into four groups according to their diabetic and VitD status. The primary end-point was composite of all-cause mortality, angina/MI and heart failure (HF). Secondary outcomes were mortality, HF and angina/MI. During a follow-up of 26.1 months (IQR 6.6–64.5), 391 subjects experienced the primary end-point. Patients with DM or hypovitD had similar rate of the composite end-point. Patients with only hypovitD or DM did not differ regarding components of composite end-point (angina p = 0.97, HF p = 0.29, mortality p = 0.62). DM and VitD deficiency had similarly adjusted risks for primary end-point (HR 1.3, 95%CI 1.05–1.61; HR 1.3, 95% CI 1.04–1.64). The adjusted HR for primary composite end-point for patients with hypovitD and DM was 1.69 (95%CI 1.25–2.29, p = 0.001) in comparison to patients with neither hypoD nor DM. In conclusion, DM and hypovitD, individually and synergistically, are associated with a worse outcome after MI.
Optimization of Breast Tomosynthesis Visualization through 3D Volume Rendering
Authors: Mota Ana M. , Clarkson Matthew J. , Almeida Pedro , Matela Nuno
Published: July 2020

3D volume rendering may represent a complementary option in the visualization of Digital Breast Tomosynthesis (DBT) examinations by providing an understanding of the underlying data at once. Rendering parameters directly influence the quality of rendered images. The purpose of this work is to study the influence of two of these parameters (voxel dimension in z direction and sampling distance) on DBT rendered data. Both parameters were studied with a real phantom and one clinical DBT data set. The voxel size was changed from 0.085 × 0.085 × 1.0 mm3 to 0.085 × 0.085 × 0.085 mm3 using ten interpolation functions available in the Visualization Toolkit library (VTK) and several sampling distance values were evaluated. The results were investigated at 90º using volume rendering visualization with composite technique. For phantom quantitative analysis, degree of smoothness, contrast-to-noise ratio, and full width at half maximum of a Gaussian curve fitted to the profile of one disk were used. Additionally, the time required for each visualization was also recorded. Hamming interpolation function presented the best compromise in image quality. The sampling distance values that showed a better balance between time and image quality were 0.025 mm and 0.05 mm. With the appropriate rendering parameters, a significant improvement in rendered images was achieved.
Multi-Objective Optimization of Turning Operation of Stainless Steel Using a Hybrid Whale Optimization Algorithm
Authors: Tanvir Mahamudul Hasan , Hussain Afzal , Rahman M. M. Towfiqur , Ishraq Sakib , Zishan Khandoker , Rahul SK Tashowar Tanzim , Habib Mohammad Ahsan
Published: July 2020

In manufacturing industries, selecting the appropriate cutting parameters is essential to improve the product quality. As a result, the applications of optimization techniques in metal cutting processes is vital for a quality product. Due to the complex nature of the machining processes, single objective optimization approaches have limitations, since several different and contradictory objectives must be simultaneously optimized. Multi-objective optimization method is introduced to find the optimum cutting parameters to avoid this dilemma. The main objective of this paper is to develop a multi-objective optimization algorithm using the hybrid Whale Optimization Algorithm (WOA). In order to perform the multi-objective optimization, grey analysis is integrated with the WOA algorithm. In this paper, Stainless Steel 304 is utilized for turning operation to study the effect of machining parameters such as cutting speed, feed rate and depth of cut on surface roughness, cutting forces, power, peak tool temperature, material removal rate and heat rate. The output parameters are obtained through series of simulations and experiments. Then by using this hybrid optimization algorithm the optimum machining conditions for turning operation is achieved by considering unit cost and quality of production. It is also found that with the change of output parameter weightage, the optimum cutting condition varies. In addition to that, the effects of different cutting parameters on surface roughness and power consumption are analysed.
The Optimization of Machining Parameters for Milling Operations by Using the Nelder–Mead Simplex Method
Authors: Lee Yubin , Resiga Alin , Yi Sung , Wern Chien
Published: July 2020

The purpose of machining operations is to make specific shapes or surface characteristics for a product. Conditions for machining operations were traditionally selected based on geometry and surface finish requirements. However, nowadays, many researchers are optimizing machining parameters since high-quality products can be produced using more expensive and advanced machines and tools. There are a few methods to optimize the machining process, such as minimizing unit production time or cost or maximizing profit. This research focused on maximizing the profit of computer numerical control (CNC) milling operations by optimizing machining parameters. Cutting speeds and feed are considered as the main process variables to maximize the profit of CNC milling operations as they have the greatest effect on machining operation. In this research, the Nelder–Mead simplex method was used to maximize the profit of CNC milling processes by optimizing machining parameters. The Nelder–Mead simplex method was used to calculate best, worst, and second-worst value based on an initial guess. The possible range of machining parameters was limited by several constraints. The Nelder–Mead simplex method yielded a profit of 3.45 ($/min) when applied to a commonly used case study model.
Disturbance of the Regenerative Effect by Use of Milling Tools Modified with Asymmetric Dynamic Properties
Authors: Baumann Jonas , Wirtz Andreas , Siebrecht Tobias , Biermann Dirk
Published: July 2020

Milling processes are often limited by self-excited vibrations of the tool or workpiece, generated by the regenerative effect, especially when using long cantilevered tools or machining thin-walled workpieces. The regenerative effect arises from a periodic modulation of the uncut chip thickness within the frequencies of the eigenmodes, which results in a critical excitation in the consecutive cuts or tooth engagements. This paper presents a new approach for disturbing the regenerative effect by using milling tools which are modified with asymmetric dynamic properties. A four-fluted milling tool was modified with parallel slots in the tool shank in order to establish asymmetric dynamic characteristics or different eigenfrequencies for consecutive tooth engagements, respectively. Measurements of the frequency response functions at the tool tip showed a decrease in the eigenfrequencies as well as an increase in the dynamic compliance in the direction of the grooves. Milling experiments with a constant width of cut and constantly increasing axial depth of cut indicated a significant increase in the stability limit for the specific preparations of up to 69%.
Fish Assemblage Structure Comparison between Freshwater and Estuarine Habitats in the Lower Nakdong River, South Korea
Authors: Park Joo Myun , Riedel Ralf , Ju Hyun Hee , Choi Hee Chan
Published: July 2020

Variabilities of biological communities in lower reaches of urban river systems are highly influenced by artificial constructions, alterations of flow regimes and episodic weather events. Impacts of estuary weirs on fish assemblages are particularly distinct because the weirs are disturbed in linking between freshwater and estuarine fish communities, and migration successes for regional fish fauna. This study conducted fish sampling at the lower reaches of the Nakdong River to assess spatio-temporal variations in fish assemblages, and effects of estuary weir on structuring fish assemblage between freshwater and estuary habitats. In total, 20,386 specimens comprising 78 species and 41 families were collected. The numerical dominant fish species were Tachysurus nitidus (48.8% in total abundance), Hemibarbus labeo (10.7%) and Chanodichthys erythropterus (3.6%) in the freshwater region, and Engraulis japonicus (10.0%), Nuchequula nuchalis (7.7%) and Clupea pallasii (5.2%) in the estuarine site. The fish sampled were primarily small species or the juveniles of larger species at the estuary region, while all life stages of fishes were observed at the freshwater habitats. The diversity patterns of fish assemblages varied greatly according to study site and season, with higher trends at estuarine sites during the warm-rainy season. No significant difference in diversity between freshwater and estuarine sites during the cold-dry season were found. Multivariate analyses of fish assemblage showed spatial and seasonal differences of assemblage structures. Higher effects of between-site variability but not within seasonal variability at each site were observed. Variations in assemblage structures were due to different contributions of dominant species in each habitat. Common freshwater species characterized the fish assemblage in the freshwater region, while marine juveniles were significantly associated with the estuarine habitat. The results from the ecological guild analyses showed distinct ecological roles for freshwater and marine species, and overlapping roles for fish sampled at the fishways. The lower reaches of the Nakdong River are an important ecosystem for both freshwater and marine juveniles. Nakdong River estuarine residents and migrant fishes, however, have been negatively affected by the construction of the weir (gravity dam), due to the obstruction to migration from and to freshwater habitats. Conservation and management policies aimed at minimizing anthropogenic influences on estuary ecosystems should focus on evaluating ecological functions of estuary weirs.
An Alternative Pricing System through Bayesian Estimates and Method of Moments in a Bonus-Malus Framework for the Ghanaian Auto Insurance Market
Authors: Jacob Azaare , Wu Zhao
Published: July 2020

This paper examines the current No-Claim Discount (NCD) system used in Ghana’s auto insurance market as inefficient and outmoded and, therefore, proposes an alternative optimal Bonus-Malus System (BMS) intended to meet the present market conditions and demand. It appears that the existing BMS fails to acknowledge the frequency and severity of policyholders’ claims in its design. We minimized the auto insurance portfolios’ risk through Bayesian estimation and found that the risk is well fitted by gamma, with the claim distribution modeled by the negative binomial law with the expected number of claims (a priori) as 14%. The models presented in this paper recognize the longevity of accident-free driving and fully reward higher discounts to policyholders from the second year when the true characteristics of the hidden risks posed to the pool have been ascertained. The BMS finally constructed using the net premium principle is very optimal and has reasonable punishment and rewards for both good and bad drivers, which could also be useful in other developing economies.
From Tactical Urbanism Action to Institutionalised Urban Planning and Educational Tool: The Evolution of Park(ing) Day
Authors: Herman Krzysztof , Rodgers Maria
Published: July 2020

A singular and modest activist action, a temporary park created in San Francisco, grew into the global urban Park(ing) Day (PD) phenomenon. This tactical urbanism event not only expanded to be annually celebrated in thousands of parking lots all over the world but became an inspiration for urban planning and policy changes. The permanent rendition of Park(ing) Day, parklets, resulted from the movement but did not stop the spread of PD itself. This article presents case studies from New Zealand and Poland, two geographically and culturally distant locations where PD has further developed and evolved gaining local qualities. Through research methods such as research in design, secondary data analysis and expert interviews we study the trajectory of PD evolution and the role and interpretation of it in different parts of the globe. The results show a narrative of successive popularisation and institutionalisation as well as diversification. Departing from its grassroots, guerilla and assertive traits, PD has grown to become an artistic, creative and urban planning tool. As an established, recognised action and an ‘attractive’ idea, PD has great potential for designer education, allowing a venue for implementing methods such as design-build and live project.
Nocturnal Lagophthalmos and Sleep Quality in Patients with Dry Eye Disease
Authors: Takahashi Aya , Negishi Kazuno , Ayaki Masahiko , Uchino Miki , Tsubota Kazuo
Published: July 2020

Nocturnal lagophthalmos (NL) refers to the inability to close the eyelids during sleep, which is known to affect dry eye disease (DED) symptoms and sleep quality. This study aimed to evaluate the prevalence of NL and sleep quality in DED patients. We launched a survey website to recruit 2000 Japanese. The participants were asked to answer a questionnaire about DED, sleep quality, and happiness. Participants were divided into two groups according to the presence of DED, and responses were compared between the groups. The DED group was comprised of 890 subjects (44 ± 13.8 years, 359 males) and women were predominant (p < 0.001). Sleep duration was significantly shorter (p = 0.008), sleep latency was longer (p < 0.001), and sleep efficacy was worse compared with the non-DED group (p < 0.001). Furthermore, people belonging to the DED group were more frequently working night shifts (p < 0.001). NL was more prevalent in the DED group (p = 0.007). Logistic regression analysis showed that NL correlated with younger age, symptomatic DED, and eye symptoms upon waking. The current study suggested that NL was associated with worsened DED symptoms and poor sleep quality. Preventative eye care for lagophthalmos before and during sleep may be helpful for DED and sleep quality.
Pharmacokinetic Interactions between Herbal Medicines and Drugs: Their Mechanisms and Clinical Relevance
Authors: Rombolà Laura , Scuteri Damiana , Marilisa Straface , Watanabe Chizuko , Morrone Luigi Antonio , Bagetta Giacinto , Corasaniti Maria Tiziana
Published: July 2020

The therapeutic efficacy of a drug or its unexpected unwanted side effects may depend on the concurrent use of a medicinal plant. In particular, constituents in the medicinal plant extracts may influence drug bioavailability, metabolism and half-life, leading to drug toxicity or failure to obtain a therapeutic response. This narrative review focuses on clinical studies improving knowledge on the ability of selected herbal medicines to influence the pharmacokinetics of co-administered drugs. Moreover, in vitro studies are useful to anticipate potential herbal medicine-drug interactions. In particular, they help to elucidate the cellular target (metabolic or transporter protein) and the mechanism (induction or inhibition) by which a single constituent of the herbal medicine acts. The authors highlight the difficulties in predicting herbal–drug interactions from in vitro data where high concentrations of extracts or their constituents are used and pharmacokinetics are missed. Moreover, the difficulty to compare results from human studies where different kinds of herbal extracts are used is discussed. The herbal medicines discussed are among the best sellers and they are reported in the “Herbal Medicines for Human Use” section of the European Medicinal Agency (EMA).
Assessing Viral Abundance and Community Composition in Four Contrasting Regions of the Southern Ocean
Authors: Sotomayor-Garcia Ana , Montserrat Sala Maria , Ferrera Isabel , Estrada Marta , Vázquez-Domínguez Evaristo , Emelianov Mikhail , Cortés Pau , Marrasé Cèlia , Ortega-Retuerta Eva , Nunes Sdena , M. Castillo Yaiza , Serrano Cuerva Maria , Sebastián Marta , Dall’Osto Manuel , Simó Rafel , Vaqué Dolors
Published: July 2020

We explored how changes of viral abundance and community composition among four contrasting regions in the Southern Ocean relied on physicochemical and microbiological traits. During January–February 2015, we visited areas north and south of the South Orkney Islands (NSO and SSO) characterized by low temperature and salinity and high inorganic nutrient concentration, north of South Georgia Island (NSG) and west of Anvers Island (WA), which have relatively higher temperatures and lower inorganic nutrient concentrations. Surface viral abundance (VA) was highest in NSG (21.50 ± 10.70 × 106 viruses mL−1) and lowest in SSO (2.96 ± 1.48 × 106 viruses mL−1). VA was positively correlated with temperature, prokaryote abundance and prokaryotic heterotrophic production, chlorophyll a, diatoms, haptophytes, fluorescent organic matter, and isoprene concentration, and was negatively correlated with inorganic nutrients (NO3−, SiO42−, PO43−), and dimethyl sulfide (DMS) concentrations. Viral communities determined by randomly amplified polymorphic DNA–polymerase chain reaction (RAPD-PCR) were grouped according to the sampling location, being more similar within them than among regions. The first two axes of a canonical correspondence analysis, including physicochemical (temperature, salinity, inorganic nutrients—NO3−, SiO42−, and dimethyl sulfoniopropionate -DMSP- and isoprene concentrations) and microbiological (chlorophyll a, haptophytes and diatom, and prokaryote abundance and prokaryotic heterotrophic production) factors accounted for 62.9% of the variance. The first axis, temperature-related, accounted for 33.8%; the second one, salinity-related, accounted for 29.1%. Thus, different environmental situations likely select different hosts for viruses, leading to distinct viral communities.
Catalytic Addition of Indole-2-Carboxylic Acid to 1-Hexyne
Authors: Francos Javier , Díaz-Álvarez Alba E. , Cadierno Victorio
Published: July 2020

The synthesis of two novel enol esters, namely hex-1-en-2-yl indole-2-carboxylate and hex-1-en-2-yl 1-(hex-1-en-2-yl)-indole-2-carboxylate, is presented. Both compounds were generated by addition of indole-2-carboxylic acid to 1-hexyne employing [RuCl2(η6-p-cymene)(PPh3)] and [AuCl(PPh3)]/AgPF6, respectively, as catalysts.
A Study on the Reduction in Hydration Heat and Thermal Strain of Concrete with Addition of Sugarcane Bagasse Fiber
Authors: Ribeiro Bruno , Yamamoto Takashi , Yamashiki Yosuke
Published: July 2020

Early prevention methods in massive concrete structures to control the heat of hydration and, consequently, the development of cracks due to thermal expansion are important subjects, since these cracks may compromise structural integrity. In the present study, the sugarcane residues in massive concrete were used in order to investigate the reduction in the heat of hydration, the thermal expansion resistance, and also the fresh and mechanical properties of the concrete. The results showed that, by adding 2.0% of bagasse fiber and 5.0% of pozzolanic material to the concrete, the heat of hydration was reduced, and the strain due to the thermal expansion was smaller than the control mixture. Moreover, the compressive, flexural, and split tensile strength increased in comparison to the control mixture.
A New Approach on Datko–Zabczyk Method for Nonuniform Exponential Stability
Authors: Lupa Nicolae
Published: July 2020

We provide a sequence of projections on the linear space of all sequences and connect the existence of nonuniform exponential stability to the restrictions of these projections on a class of Banach sequence spaces defined by a discrete dynamics. As a consequence, we obtain a Datko–Zabczyk type characterization of nonuniform exponential stability. We develop our analysis without any assumption on the invertibility of the dynamics, thus our results are applicable to a large class of difference equations.
Hybrid LQR-PI Control for Microgrids under Unbalanced Linear and Nonlinear Loads
Authors: Valencia-Rivera Gerardo Humberto , Merchan-Villalba Luis Ramon , Tapia-Tinoco Guillermo , Lozano-Garcia Jose Merced , Ibarra-Manzano Mario Alberto , Avina-Cervantes Juan Gabriel
Published: July 2020

A hybrid Linear Quadratic Regulator (LQR) and Proportional-Integral (PI) control for a MicroGrid (MG) under unbalanced linear and nonlinear loads was presented and evaluated in this paper. The designed control strategy incorporates the microgrid behavior, low-cost LQR, and error reduction in the stationary state by the PI control, to reduce the overall energetic cost of the classical PI control applied to MGs. A Genetic Algorithm (GA) calculates the parameters of LQR with high-accuracy fitness function to obtain the optimal controller parameters as settling time and overshoot. The gain values of the classical PI controller were determined through the improved LQR values and geometrical root locus. When MG operates in the grid-tied mode under unbalanced conditions, the controller performance of the Current Source Inverter (CSI) of the MG is considerably affected. Consequently, the CSI operates in a negative-sequence mode to compensate for unbalanced current at the Point of Common Coupling (PCC) between the MG and the utility grid. The study cases involved the reduction of the negative-sequence percentage in the current at the PCC, mitigation of harmonics in the current signal injected by the MG, and close related power quality issues. All these cases have been analyzed by implementing an MG connected at the PCC of a low-voltage distribution network. A numerical model of the MG in Matlab/Simulink was implemented to verify the performance of the designed LQR-PI control to mitigate or overcome the power quality concerns. The extensive simulations have permitted verifying the robustness and effectiveness of the proposed strategy.
Fixed Point Theorem Based Solvability of 2-Dimensional Dissipative Cubic Nonlinear Klein-Gordon Equation
Authors: Asaduzzaman Md. , Kilicman Adem , Ali Md. Zulfikar , Sapar Siti Hasana
Published: July 2020

The purpose of this article is to establish the solvability of the 2-Dimensional dissipative cubic nonlinear Klein-Gordon equation (2DDCNLKGE) through periodic boundary value conditions (PBVCs). The analysis of this study is founded on the Galerkin’s method (GLK) and the Leray-Schauder’s fixed point theorem (LS). First, the GLK method is used to construct some uniform priori estimates of approximate solution to the corresponding equation of 2DDCNLKGE. Finally, the LS fixed point theorem is applied to obtain the efficient and straightforward existence and uniqueness criteria of time periodic solution to the 2DDCNLKGE.
Coefficient Related Studies for New Classes of Bi-Univalent Functions
Authors: Páll-Szabó Ágnes Orsolya , Oros Georgia Irina
Published: July 2020

Using the recently introduced Sălăgean integro-differential operator, three new classes of bi-univalent functions are introduced in this paper. In the study of bi-univalent functions, estimates on the first two Taylor–Maclaurin coefficients are usually given. We go further in the present paper and bounds of the first three coefficients a 2 , a 3 and a 4 of the functions in the newly defined classes are given. Obtaining Fekete–Szegő inequalities for different classes of functions is a topic of interest at this time as it will be shown later by citing recent papers. So, continuing the study on the coefficients of those classes, the well-known Fekete–Szegő functional is obtained for each of the three classes.
Dual Associate Null Scrolls with Generalized 1-Type Gauss Maps
Authors: Qian Jinhua , Fu Xueshan , Jung Seoung Dal
Published: July 2020

In this work, a pair of dual associate null scrolls are defined from the Cartan Frenet frame of a null curve in Minkowski 3-space. The fundamental geometric properties of the dual associate null scrolls are investigated and they are related in terms of their Gauss maps, especially the generalized 1-type Gauss maps. At the same time, some representative examples are given and their graphs are plotted by the aid of a software programme.
Non-Gaussian Quadrature Integral Transform Solution of Parabolic Models with a Finite Degree of Randomness
Authors: Casabán María-Consuelo , Company Rafael , Jódar Lucas
Published: July 2020

In this paper, we propose an integral transform method for the numerical solution of random mean square parabolic models, that makes manageable the computational complexity due to the storage of intermediate information when one applies iterative methods. By applying the random Laplace transform method combined with the use of Monte Carlo and numerical integration of the Laplace transform inversion, an easy expression of the approximating stochastic process allows the manageable computation of the statistical moments of the approximation.
Astaxanthin as a Putative Geroprotector: Molecular Basis and Focus on Brain Aging
Authors: Sorrenti Vincenzo , Davinelli Sergio , Scapagnini Giovanni , Willcox Bradley J. , Allsopp Richard C. , Willcox Donald C.
Published: July 2020

In recent years, the scientific interest in natural compounds with geroprotective activities has grown exponentially. Among the various naturally derived molecules, astaxanthin (ASX) represents a highly promising candidate geroprotector. By virtue of the central polyene chain, ASX acts as a scavenger of free radicals in the internal membrane layer and simultaneously controls oxidation on the membrane surface. Moreover, several studies have highlighted ASX’s ability to modulate numerous biological mechanisms at the cellular level, including the modulation of transcription factors and genes directly linked to longevity-related pathways. One of the main relevant evolutionarily-conserved transcription factors modulated by astaxanthin is the forkhead box O3 gene (FOXO3), which has been recognized as a critical controller of cell fate and function. Moreover, FOXO3 is one of only two genes shown to robustly affect human longevity. Due to its tropism in the brain, ASX has recently been studied as a putative neuroprotective molecule capable of delaying or preventing brain aging in different experimental models of brain damage or neurodegenerative diseases. Astaxanthin has been observed to slow down brain aging by increasing brain-derived neurotrophic factor (BDNF) levels in the brain, attenuating oxidative damage to lipids, protein, and DNA and protecting mitochondrial functions. Emerging data now suggest that ASX can modulate Nrf2, FOXO3, Sirt1, and Klotho proteins that are linked to longevity. Together, these mechanisms provide support for a role of ASX as a potential geroneuroprotector.
Genome-Inspired Chemical Exploration of Marine Fungus Aspergillus fumigatus MF071
Authors: Han Jianying , Liu Miaomiao , Jenkins Ian D. , Liu Xueting , Zhang Lixin , Quinn Ronald J. , Feng Yunjiang
Published: July 2020

The marine-derived fungus Aspergillus fumigatus MF071, isolated from sediment collected from the Bohai Sea, China, yielded two new compounds 19S,20-epoxy-18-oxotryprostatin A (1) and 20-hydroxy-18-oxotryprostatin A (2), in addition to 28 known compounds (3–30). The chemical structures were established on the basis of 1D, 2D NMR and HRESIMS spectroscopic data. This is the first report on NMR data of monomethylsulochrin-4-sulphate (4) and pseurotin H (10) as naturally occurring compounds. Compounds 15, 16, 20, 23, and 30 displayed weak antibacterial activity (minimum inhibitory concentration: 100 μg/mL). Compounds 18 and 19 exhibited strong activity against S. aureus (minimum inhibitory concentration: 6.25 and 3.13 μg/mL, respectively) and E. coli (minimum inhibitory concentration: 6.25 and 3.13 μg/mL, respectively). A genomic data analysis revealed the putative biosynthetic gene clusters ftm for fumitremorgins, pso for pseurotins, fga for fumigaclavines, and hel for helvolinic acid. These putative biosynthetic gene clusters fundamentally underpinned the enzymatic and mechanistic function study for the biosynthesis of these compounds. The current study reported two new compounds and biosynthetic gene clusters of fumitremorgins, pseurotins, fumigaclavines and helvolinic acid from Aspergillus fumigatus MF071.
Bilateral Comparisons of Quadriceps Thickness after Anterior Cruciate Ligament Reconstruction
Authors: Lee Joo-Hyun , Cheon Soul , Jun Hyung-Pil , Huang Yu-Lun , Chang Eunwook
Published: July 2020

Background and objectives: Anterior cruciate ligament reconstruction (ACLR) often results in quadricep atrophy. The purpose of this study was to compare the bilateral thickness of each quadricep component before and after ACLR. Materials and Methods: Cross-sectional study design. In 14 patients who underwent ACLR, bilateral quadricep muscle thicknesses were measured using a portable ultrasound device, 1 h before and 48–72 h after ACLR. Two-way analysis of variance (ANOVA) was used to compare muscle thickness pre- and post-ACLR between the limbs. Results: The primary finding was that the vastus intermedius (VI) muscle was significantly smaller in the reconstructed limb after ACLR compared to that in the healthy limb (Reconstructed limb; RCL = Pre-operated (PRE): 19.89 ± 6.91 mm, Post-operated(POST): 16.04 ± 6.13 mm, Healthy limb; HL = PRE: 22.88 ± 6.07, POST: 20.90 ± 5.78 mm, F = 9.325, p = 0.009, η2p = 0.418). Conclusions: The results represent a selective surgical influence on the quadricep muscle thickness. These findings highlight the need of advanced strengthening exercises in order to restore VI thickness after ACLR.
Performance of Thermo-Mechanically Processed AA7075 Alloy at Elevated Temperatures—From Microstructure to Mechanical Properties
Authors: Sajadifar Seyed Vahid , Scharifi Emad , Weidig Ursula , Steinhoff Kurt , Niendorf Thomas
Published: July 2020

This study focuses on the high temperature characteristics of thermo-mechanically processed AA7075 alloy. An integrated die forming process that combines solution heat treatment and hot forming at different temperatures was employed to process the AA7075 alloy. Low die temperature resulted in the fabrication of parts with higher strength, similar to that of T6 condition, while forming this alloy in the hot die led to the fabrication of more ductile parts. Isothermal uniaxial tensile tests in the temperature range of 200–400 °C and at strain rates ranging from 0.001–0.1 s−1 were performed on the as-received material, and on both the solution heat-treated and the thermo-mechanically processed parts to explore the impacts of deformation parameters on the mechanical behavior at elevated temperatures. Flow stress levels of AA7075 alloy in all processing states were shown to be strongly temperature- and strain-rate dependent. Results imply that thermo-mechanical parameters are very influential on the mechanical properties of the AA7075 alloy formed at elevated temperatures. Microstructural studies were conducted by utilizing optical microscopy and a scanning electron microscope to reveal the dominant softening mechanism and the level of grain growth at elevated temperatures.
Investigation on Speed-Load Sensitivity to Tribological Properties of Copper Metal Matrix Composites for Braking Application
Authors: Xiao Yelong , Yao Pingping , Zhou Haibin , Zhang Zhongyi , Gong Taimin , Zhao Lin , Deng Minwen
Published: July 2020

A sensitivity analysis of braking speed and normal load on tribological properties of copper metal matrix composites (Cu-MMCs) was investigated using a subscale dynamometer. The morphologies of the worn surface and subsurface were observed by a scanning electron microscope and 3D video microscope. The results indicated that temperatures on the Cu-MMC surface increased with increasing the braking speed and normal load. The average coefficient of friction gradually decreased as the braking speed or normal load increased, and a slight decrease in the wear rate with increasing the braking speed up to 17 m/s after which a clear increasing trend was observed. As the normal load increased from 612 N to 1836 N, the wear rate decreased firstly and then promptly decreased. The transition in wear mechanism of Cu-MMC significantly depended on braking speed and normal load.
Correlations between the Surface Topography and Mechanical Properties of Friction Stir Welds
Authors: Hartl Roman , Vieltorf Fabian , Zaeh Michael F.
Published: July 2020

Friction stir welding is a modern pressure welding process, which is particularly suitable for aluminum alloys. Several studies have been conducted to investigate the interrelations between the process parameters, such as the welding speed and the tool rotational speed, and the resulting mechanical properties of the joint. This study explored the connections between the surface topography of the welds, such as the flash height and the seam underfill, and their mechanical properties (ultimate tensile strength; elongation at break; and Vickers hardness). For this purpose, a total of 54 welding experiments at three different welding speeds were conducted using the aluminum alloy EN AW-6082-T6. The welded specimens were examined using visual inspection, topographic analysis, metallography, hardness measurements, and uniaxial tensile tests. Afterward, a statistical analysis was performed in order to determine the correlation coefficients between the surface topography and the mechanical properties of the welds. The strongest correlations were between the surface topography and the ultimate tensile strength. Thereby, the most pronounced relations were found between the seam underfill as well as the arc texture formation of the weld and its ultimate tensile strength. The interrelations between the surface topography and the elongation at break, as well as the hardness of the welds, were less pronounced. The higher the welding speed became, the less pronounced the interrelations were. The results show the potential of a non-destructive monitoring system based on the topography to support the prediction of the acceptability of welded parts.
Activation Pretreatment and Leaching Process of High-Alumina Coal Fly Ash to Extract Lithium and Aluminum
Authors: Li Shenyong , Bo Penghui , Kang Lianwei , Guo Haigang , Gao Wenyue , Qin Shenjun
Published: July 2020

Experiments were conducted to investigate the process of aluminum and lithium extraction from high-alumina coal fly ash (HCFA) generated from coal-fired power plants located in northern China. The presence of mullite and other aluminosilicates lead to low reactivity of coal fly ash. An activation pretreatment that destroys an inert composition of coal is necessary. The activation roasting of coal fly ash using sodium chloride and a subsequent leaching process were performed in this research. The results showed that almost no aluminum and lithium were dissolved under direct water leaching, while about 7% and 10% of those were leached into the acid solution respectively. Adding NaCl enhanced the atmospheric pressure leaching of aluminum and lithium with a leaching rate around 50%. Phase analysis and equilibrium calculations results showed that the roasting reaction between the HCFA and NaCl occurred, which led to generation of main new phase NaAlSi3O8. The pressure extraction efficiencies of aluminum and lithium were increased to about 93% and 98%, respectively. The implications of the findings provide an alternative process for recovering aluminum and lithium from readily available high-alumina coal fly ash.
An Electrochemical Immunosensor for Sensitive Detection of the Tumor Marker Carcinoembryonic Antigen (CEA) Based on Three-Dimensional Porous Nanoplatinum/Graphene
Authors: Jing Aihua , Xu Qiong , Feng Wenpo , Liang Gaofeng
Published: July 2020

Carcinoembryonic antigen (CEA) is an important broad-spectrum tumor marker. The quantitative detection of a low concentration of CEA has important medical significance. In this study, three-dimensional porous graphene-oxide-supported platinum metal nanoparticles (3DPt/HGO) composites were prepared by a wet chemical method and modified on an electrode with enhanced conductivity, a large surface area, and good adsorption of immobilizing antibodies (Ab1). Horseradish peroxidase (HRP)-functionalized Au nanoparticles were fabricated to label the secondary antibodies (Ab2). The proposed immunosensor showed a good linear relationship in the range of 0.001–150 ng/mL for CEA and a detection limit of 0.0006 ng/mL. The immunosensor had high sensitivity, good stability and reproducibility, and has great application prospects for the clinical diagnosis of cancer.
Mycobacterium avium Subspecies paratuberculosis Infects and Replicates within Human Monocyte-Derived Dendritic Cells
Authors: Rees William D. , Lorenzo-Leal Ana C. , Steiner Theodore S. , Bach Horacio
Published: July 2020

Background: Mycobacterium avium subspecies paratuberculosis (MAP), a member of the mycobacteriaceae family, causes Johne’s disease in ruminants, which resembles Crohn’s disease (CD) in humans. MAP was proposed to be one of the causes of human CD, but the evidence remains elusive. Macrophages were reported to be the only cell where MAP proliferates in ruminants and humans and is likely the major producer of TNFα-associated inflammation. However, whether human dendritic cells (DCs), another major antigen-presenting cell (APC), have the ability to harbor MAP and disseminate infection, remains unknown. Methods: Human monocyte-derived dendritic cells (moDCs) were infected with MAP and phagocytosis and intracellular survival were quantified by immunofluorescence (IF) and colony counts, respectively. MoDC cytokine expression was measured via ELISA and their activation state was measured via flow cytometry. Results: We showed that MAP can infect and replicate in human moDCs as means to evade the immune system for successful infection, through inhibition of the phago-lysosome fusion via the secretion of protein tyrosine phosphatase PtpA. This mechanism initially led to a state of tolerance in moDCs and then subsequently caused a pro-inflammatory response as infection persisted, characterized by the upregulation of IL-6 and TNFα, and downregulation of IL-10. Moreover, we showed that moDCs have the ability to phagocytose up to 18% of MAP, when exposed at a multiplicity of infection of 1:1. Conclusion: Infection and subsequent proliferation of MAP within moDCs could provide a unique means for the dissemination of MAP to lymphoid tissue, while altering immune responses to facilitate the persistence of infection of host tissues in CD.
Exploring the Pathogenic Potential of Vibrio vulnificus Isolated from Seafood Harvested along the Mangaluru Coast, India
Authors: D’Souza Caroline , Prithvisagar Kattapuni Suresh , Deekshit Vijay Kumar , Karunasagar Indrani , Karunasagar Iddya , Kumar Ballamoole Krishna
Published: July 2020

It has been observed that not all strains of Vibrio vulnificus are virulent. Determining the virulence of strains that are frequently present in seafood is of significance for ensuring seafood safety. This study is an attempt to predict the virulence of seafood-borne V. vulnificus isolated along the Mangaluru Coast, India. The isolates tested possessed a vcgC gene sequence with high similarity to that in the clinical strain. Transcriptional analysis of core virulence genes in seafood isolate E4010 showed the phenomenon of contact-mediated expression of rtxA1 which correlated well with the actin disintegration and cytotoxicity. These results suggest that the seafood isolates tested in this study possess a functional RtxA1 which could help in initiating the infection. However, other putative virulence genes such as vvpE encoding an extracellular protease, vvhA encoding hemolysin, flp encoding tad pilin and ompU encoding fibronectin-binding protein were also constitutively expressed. Virulence-associated attributes such as cytotoxicity and adherence matched the response of the clinical strain (p > 0.05). On the other hand, the environmental strains showed higher serum sensitivity compared with the clinical strain. These findings show that the part of virulence attributes required for the disease process might be intact in these isolates.
Untargeted Metagenomic Investigation of the Airway Microbiome of Cystic Fibrosis Patients with Moderate-Severe Lung Disease
Authors: Bacci Giovanni , Taccetti Giovanni , Dolce Daniela , Armanini Federica , Segata Nicola , Di Cesare Francesca , Lucidi Vincenzina , Fiscarelli Ersilia , Morelli Patrizia , Casciaro Rosaria , Negroni Anna , Mengoni Alessio , Bevivino Annamaria
Published: July 2020

Although the cystic fibrosis (CF) lung microbiota has been characterized in several studies, little is still known about the temporal changes occurring at the whole microbiome level using untargeted metagenomic analysis. The aim of this study was to investigate the taxonomic and functional temporal dynamics of the lower airway microbiome in a cohort of CF patients. Multiple sputum samples were collected over 15 months from 22 patients with advanced lung disease regularly attending three Italian CF Centers, given a total of 79 samples. DNA extracted from samples was subjected to shotgun metagenomic sequencing allowing both strain-level taxonomic profiling and assessment of the functional metagenomic repertoire. High inter-patient taxonomic heterogeneity was found with short-term compositional changes across clinical status. Each patient exhibited distinct sputum microbial communities at the taxonomic level, and strain-specific colonization of both traditional and atypical CF pathogens. A large core set of genes, including antibiotic resistance genes, were shared across patients despite observed differences in clinical status, and consistently detected in the lung microbiome of all subjects independently from known antibiotic exposure. In conclusion, an overall stability in the microbiome-associated genes was found despite taxonomic fluctuations of the communities.
Importance of Initial Interfacial Steps during Chalcopyrite Bioleaching by a Thermoacidophilic Archaeon
Authors: Safar Camila , Castro Camila , Donati Edgardo
Published: July 2020

Studies of thermophilic microorganisms have shown that they have a considerable biotechnological potential due to their optimum growth and metabolism at high temperatures. Thermophilic archaea have unique characteristics with important biotechnological applications; many of these species could be used in bioleaching processes to recover valuable metals from mineral ores. Particularly, bioleaching at high temperatures using thermoacidophilic microorganisms can greatly improve metal solubilization from refractory mineral species such as chalcopyrite (CuFeS2), one of the most abundant and widespread copper-bearing minerals. Interfacial processes such as early cell adhesion, biofilm development, and the formation of passive layers on the mineral surface play important roles in the initial steps of bioleaching processes. The present work focused on the investigation of different bioleaching conditions using the thermoacidophilic archaeon Acidianus copahuensis DSM 29038 to elucidate which steps are pivotal during the chalcopyrite bioleaching. Fluorescent in situ hybridization (FISH) and confocal laser scanning microscopy (CLSM) were used to visualize the microorganism–mineral interaction. Results showed that up to 85% of copper recovery from chalcopyrite could be achieved using A. copahuensis. Improvements in these yields are intimately related to an early contact between cells and the mineral surface. On the other hand, surface coverage by inactivated cells as well as precipitates significantly reduced copper recoveries.
Biogenic Silver Nanoparticles: Assessment of Their Cytotoxicity, Genotoxicity and Study of Capping Proteins
Authors: Wypij Magdalena , Jędrzejewski Tomasz , Ostrowski Maciej , Trzcińska Joanna , Rai Mahendra , Golińska Patrycja
Published: July 2020

The development of nanotechnology in the last two decades has led to the use of silver nanoparticles (AgNPs) in various biomedical applications, including antimicrobial, anti-inflammatory, and anticancer therapies. However, the potential of the medical application of AgNPs depends on the safety of their use. In this work, we assessed the in vitro cytotoxicity and genotoxicity of silver nanoparticles and identified biomolecules covering AgNPs synthesized from actinobacterial strain SH11. The cytotoxicity of AgNPs against MCF-7 human breast cancer cell line and murine macrophage cell line RAW 264.7 was studied by MTT assay, cell LDH (lactate dehydrogenase) release, and the measurement of ROS (reactive oxygen species) level while genotoxicity in Salmonella typhimurium cells was testing using the Ames test. The in vitro analysis showed that the tested nanoparticles demonstrated dose-dependent cytotoxicity against RAW 264.6 macrophages and MCF-7 breast cancer cells. Moreover, biosynthesized AgNPs did not show a mutagenic effect of S. typhimurium. The analyses and identification of biomolecules present on the surface of silver nanoparticles showed that they were associated with proteins. The SDS-PAGE (sodium dodecyl sulfate–polyacrylamide gel electrophoresis) analysis revealed the presence of 34 and 43 kDa protein bands. The identification of proteins performed by using LC-MS/MS (liquid chromatography with tandem mass spectrometry) demonstrated their highest homology to bacterial porins. Capping biomolecules of natural origin may be involved in the synthesis process of AgNPs or may be responsible for their stabilization. Moreover, the presence of natural proteins on the surface of bionanoparticles eliminates the postproduction steps of capping which is necessary for chemical synthesis to obtain the stable nanostructures required for application in medicine.
Alternative Isolation Protocol for Desulfo and Zwitterionic Cylindrospermopsin Alkaloids and Comparison of Their Toxicity in HepG2 Cells
Authors: González-Blanco Carlos , Dörr Felipe Augusto , Albuquerque Renata , Onuki Janice , Pinto Ernani
Published: July 2020

The term cylindrospermopsins (CYNs) refers to a structurally related class of cyanobacterial metabolites comprised of a tricyclic guanidine group and a hydroxymethyluracil moiety. Most reports in environmental aquatic samples refer to cylindrospermopsin (CYN), and reports on other CYN alkaloids are scarce, due, in part, to a lack of versatile isolation protocols. Thus, using commercially available solid phase extraction (SPE) cartridges, we optimized an isolation protocol for the complete recovery of CYN, 7-deoxy-cylindrospermopsin (7D-CYN) and 7-deoxy-desulfo-cylindrospermopsin (7D-desulfo-CYN) from the same aliquot. The isolation protocol was adaptable depending on the nature of the sample (solid biomass, culture broth or environmental water sample) and tolerates up to 4 L of dense culture broth or 400 mg of lyophilized biomass. To quantitate the CYN alkaloids, we validated an LC-DAD-MS2 method, which takes advantage of the UV absorption of the uracil group (λ 262 nm). Using electrospray ionization (ESI) in a positive ion mode, the high-resolution MS1 data confirms the presence of the protonated alkaloids, and the MS2 fragment assignment is reported as complementary proof of the molecular structure of the CYNs. We isolated three CYN alkaloids with different water solubility using the same lyophilized sample, with a purity that ranged from 95% to 99%. The biological activity of the purified CYNs, along with a synthetic degradation product of CYN (desulfo-cylindrospermopsin), was evaluated by assessing necrosis and apoptosis in vitro using flow cytometry. CYN’s lethal potency in HepG2 cells was greater than the other analogs, due to the presence of all four functional groups: guanidine, uracil, C-7 hydroxyl and the sulfate residue.