bluuebunny/crossref_metadata_2025 huggingface dataset:
Drug Resistance in Metastatic Breast Cancer: Tumor Targeted Nanomedicine to the Rescue
Authors: Gote Vrinda , Nookala Anantha Ram , Bolla Pradeep Kumar , Pal Dhananjay
Published: April 2021

Breast cancer, specifically metastatic breast, is a leading cause of morbidity and mortality in women. This is mainly due to relapse and reoccurrence of tumor. The primary reason for cancer relapse is the development of multidrug resistance (MDR) hampering the treatment and prognosis. MDR can occur due to a multitude of molecular events, including increased expression of efflux transporters such as P-gp, BCRP, or MRP1; epithelial to mesenchymal transition; and resistance development in breast cancer stem cells. Excessive dose dumping in chemotherapy can cause intrinsic anti-cancer MDR to appear prior to chemotherapy and after the treatment. Hence, novel targeted nanomedicines encapsulating chemotherapeutics and gene therapy products may assist to overcome cancer drug resistance. Targeted nanomedicines offer innovative strategies to overcome the limitations of conventional chemotherapy while permitting enhanced selectivity to cancer cells. Targeted nanotheranostics permit targeted drug release, precise breast cancer diagnosis, and importantly, the ability to overcome MDR. The article discusses various nanomedicines designed to selectively target breast cancer, triple negative breast cancer, and breast cancer stem cells. In addition, the review discusses recent approaches, including combination nanoparticles (NPs), theranostic NPs, and stimuli sensitive or “smart” NPs. Recent innovations in microRNA NPs and personalized medicine NPs are also discussed. Future perspective research for complex targeted and multi-stage responsive nanomedicines for metastatic breast cancer is discussed.
Aberrant Complement System Activation in Neurological Disorders
Authors: Ziabska Karolina , Ziemka-Nalecz Malgorzata , Pawelec Paulina , Sypecka Joanna , Zalewska Teresa
Published: April 2021

The complement system is an assembly of proteins that collectively participate in the functions of the healthy and diseased brain. The complement system plays an important role in the maintenance of uninjured (healthy) brain homeostasis, contributing to the clearance of invading pathogens and apoptotic cells, and limiting the inflammatory immune response. However, overactivation or underregulation of the entire complement cascade within the brain may lead to neuronal damage and disturbances in brain function. During the last decade, there has been a growing interest in the role that this cascading pathway plays in the neuropathology of a diverse array of brain disorders (e.g., acute neurotraumatic insult, chronic neurodegenerative diseases, and psychiatric disturbances) in which interruption of neuronal homeostasis triggers complement activation. Dysfunction of the complement promotes a disease-specific response that may have either beneficial or detrimental effects. Despite recent advances, the explicit link between complement component regulation and brain disorders remains unclear. Therefore, a comprehensible understanding of such relationships at different stages of diseases could provide new insight into potential therapeutic targets to ameliorate or slow progression of currently intractable disorders in the nervous system. Hence, the aim of this review is to provide a summary of the literature on the emerging role of the complement system in certain brain disorders.
Functional Roles of PARP2 in Assembling Protein–Protein Complexes Involved in Base Excision DNA Repair
Authors: Vasil’eva Inna , Moor Nina , Anarbaev Rashid , Kutuzov Mikhail , Lavrik Olga
Published: April 2021

Poly(ADP-ribose) polymerase 2 (PARP2) participates in base excision repair (BER) alongside PARP1, but its functions are still under study. Here, we characterize binding affinities of PARP2 for other BER proteins (PARP1, APE1, Polβ, and XRCC1) and oligomerization states of the homo- and hetero-associated complexes using fluorescence-based and light scattering techniques. To compare PARP2 and PARP1 in the efficiency of PAR synthesis, in the absence and presence of protein partners, the size of PARP2 PARylated in various reaction conditions was measured. Unlike PARP1, PARP2 forms more dynamic complexes with common protein partners, and their stability is effectively modulated by DNA intermediates. Apparent binding affinity constants determined for homo- and hetero-oligomerized PARP1 and PARP2 provide evidence that the major form of PARP2 at excessive PARP1 level is their heterocomplex. Autoregulation of PAR elongation at high PARP and NAD+ concentrations is stronger for PARP2 than for PARP1, and the activity of PARP2 is more effectively inhibited by XRCC1. Moreover, the activity of both PARP1 and PARP2 is suppressed upon their heteroPARylation. Taken together, our findings suggest that PARP2 can function differently in BER, promoting XRCC1-dependent repair (similarly to PARP1) or an alternative XRCC1-independent mechanism via hetero-oligomerization with PARP1.
The Effect of Longitudinal Rails on an Air Cavity Stepped Planing Hull
Authors: Cucinotta Filippo , Mancini Dario , Sfravara Felice , Tamburrino Francesco
Published: April 2021

The use of ventilated hulls is rapidly expanding. However, experimental and numerical analyses are still very limited, particularly for high-speed vessels and for stepped planing hulls. In this work, the authors present a comparison between towing tank tests and CFD analyses carried out on a single-stepped planing hull provided with forced ventilation on the bottom. The boat has identical geometries to those presented by the authors in other works, but with the addition of longitudinal rails. In particular, the study addresses the effect of the rails on the bottom of the hull, in terms of drag, and the wetted surface assessment. The computational methodology is based on URANS equation with multiphase models for high-resolution interface capture between air and water. The tests have been performed varying seven velocities and six airflow rates and the no-air injection condition. Compared to flat-bottomed hulls, a higher incidence of numerical ventilation and air–water mixing effects was observed. At the same time, no major differences were noted in terms of the ability to drag the flow aft at low speeds. Results in terms of drag reduction, wetted surface, and its shape are discussed.
Effect of Maritime Traffic on Water Quality Parameters in Santa Marta, Colombia
Authors: Rodríguez-Grimón René , Campos Nestor Hernando , Castro Ítalo Braga
Published: April 2021

Since 2013, there has been an increase (>23%) in naval traffic using maritime routes and ports on the coastal fringe of Santa Marta, Colombia. Of major concern, and described by several studies, is the relationship between maritime traffic and coastal contamination. This study proposed a maritime traffic indicator considering the simultaneous effects of several relevant measurements of water quality parameters to estimate the impact of naval activity. The approach involved developing a model including the number of vessels, hull length, and permanence time in berths. In addition, water quality variables, considering climatic seasons, were used to verify association with maritime traffic and touristic activities. The high concentrations of total coliforms (TC) and dissolved/dispersed petroleum hydrocarbons in chrysene equivalents (DDPH) reported by the International Marina of Santa Marta (SM) were affected by the local anthropic activities, including tourism, naval traffic, and urban wastewater discharges. Moreover, our results suggest the occurrence of multiple chemical impacts within Tayrona National Natural Park (PNNT) affecting conservation goals. The estimation of the maritime traffic indicator proposed in this study may be an easy and more complete tool for future studies evaluating the impact of naval activities on environmental quality.
Preliminary In Vitro Study of Fluoride Release from Selected Ormocer Materials
Authors: Kosior Piotr , Dobrzynski Maciej , Zakrzewska Aneta , Grosman Lukasz , Korczynski Mariusz , Blicharski Tomasz , Gutbier Martina , Watras Adam , Wiglusz Rafal J.
Published: April 2021

The purpose of the in vitro study presented in this paper was to determine the long-term release of fluoride ions from selected ormocer materials (Admira (A), Admira Flow (AF), Admira Seal (AS)). The release of fluoride ions from these materials into a saline solution (0.9% NaCl) and deionized water was tested for 14 weeks. In a long-term study the measurements were taken after 1 and 3 h, then 1, 2, and 3 days and then at weekly intervals for 14 weeks. In a short-term study the measurements were made after 3, 24, 48, 72, 69, 168 h, i.e., within 7 days. All materials used in the test showed a constant level of fluoride release. The highest level of cumulative release of fluoride ions into deionized water was found in the AS material (23.95 ± 4.30 μg/mm2), slightly lower in the A material (23.26 ± 4.16 μg/mm2) and the lowest in the AF material (16.79 ± 2.26 μg/mm2). The highest level of cumulative release into saline solution was found in AF (8.08 ± 1.30 μg/mm2), slightly lower in AS (7.36 ± 0.30 μg/mm2) and the lowest in A (6.73 ± 1.10 μg /mm2). After 1 h of immersion of the samples in the saline solution, the highest level of fluoride was released by AF (0.57 ± 0.06 μg/mm2) followed by A (0.20 ± 0.03 μg/mm2) and AS (0.19 ± 0.02 µg/mm2). Moreover, in the 14-week study, the total amount of fluoride release into the saline, which imitates the environment of the oral cavity, was observed as the highest in the AF sample.
Additive Manufacturing of β-NiAl by Means of Laser Metal Deposition of Pre-Alloyed and Elemental Powders
Authors: Müller Michael , Heinen Bastian , Riede Mirko , López Elena , Brückner Frank , Leyens Christoph
Published: April 2021

The additive manufacturing (AM) technique, laser metal deposition (LMD), combines the advantages of near net shape manufacturing, tailored thermal process conditions and in situ alloy modification. This makes LMD a promising approach for the processing of advanced materials, such as intermetallics. Additionally, LMD allows the composition of a powder blend to be modified in situ. Hence, alloying and material build-up can be achieved simultaneously. Within this contribution, AM processing of the promising high-temperature material β-NiAl, by means of LMD, with elemental powder blends, as well as with pre-alloyed powders, was presented. The investigations showed that by applying a preheating temperature of 1100 °C, β-NiAl could be processed without cracking. Additionally, by using pre-alloyed, as well as elemental powders, a single phase β-NiAl microstructure can be achieved in multi-layer build-ups. Major differences between the approaches were found within substrate near regions. For in situ alloying of Ni and Al, these regions are characterized by an inhomogeneous elemental distribution in a layerwise manner. However, due to the remelting of preceding layers during deposition, a homogenization can be observed, leading to a single-phase structure. This shows the potential of high temperature preheating and in situ alloying to push the development of new high temperature materials for AM.
The Effect of Cement Addition on Water Vapour Resistance Factor of Rammed Earth
Authors: Narloch Piotr , Piątkiewicz Wojciech , Pietruszka Barbara
Published: April 2021

The article aims to determine the effect of cement addition on the water vapour resistance factor of stabilized rammed earth. Literature analysis indicates that different earthen materials show large differences in water vapour resistance factor values. The high diffusion resistance of concrete concerning other construction materials suggests that cement will be one of the factors significantly affecting these values. The paper presents water vapour resistance factor test results of rammed earth with various soil particle sizes and cement contents. The obtained results showed that an increase of cement addition increases the diffusion resistance of the material. However, the diffusion resistance of cement stabilized rammed earth is still low compared to concrete.
Study of the Mechanical and Physical Behavior of Gypsum Boards with Plastic Cable Waste Aggregates and Their Application to Construction Panels
Authors: Vidales-Barriguete Alejandra , Santa-Cruz-Astorqui Jaime , Piña-Ramírez Carolina , Kosior-Kazberuk Marta , Kalinowska-Wichrowska Katarzyna , Atanes-Sánchez Evangelina
Published: April 2021

The objective of this study was to analyze the physico-mechanical properties of gypsum boards including plastic waste aggregates from cable recycling. The plastic cable waste is incorporated into the gypsum matrix without going through any type of selection and/or treatment, as it is obtained after the cable recycling process. In the experimental process, gypsum boards of different dimensions were manufactured and tested for their Young’s modulus, shock-impact resistance, flexural strength, thermal conductivity, and thermal comfort. The results obtained show a significant increase in the elasticity of the boards with plastic waste (limited cracking), compliance with the minimum value of flexural strength, and a slight improvement in the thermal conductivity coefficient (lower energy demand) and surface comfort (reduced condensation and greater adherence). Therefore, the analyzed material could provide a suitable alternative to currently marketed gypsum boards, contributing to sustainable construction not only in new constructions, but also in building renovations.
Vibrational Spectral Analysis of Natisite (Na2TiSiO5) and its Structure Evolution in Water and Sulfuric Acid Solutions
Authors: Meng Fancheng , Liu Yahui , Wang Lina , Chen Desheng , Zhao Hongxin , Zhen Yulan , Chen Jing , Qi Tao
Published: April 2021

Natisite (Na2TiSiO5) is a layered sodium titanosilicate containing TiO5 square pyramids. The structure evolution of natisite in water and acid solutions is the basis for its potential applications. With Na2SiO3 as the silicon source, natisite with the shape of the square sheet was selectively prepared from the hydrothermal method with 14.3 mol/L NaOH solution at 240 °C. Natisite has 20 Raman active modes and 22 infrared active modes from the first-principles calculations within density functional theory, and the calculated Raman and infrared spectra agree well with the experimental ones. The characteristic Raman peak at 844 cm−1 is caused by the symmetric stretching of the apical Ti–O bond in the TiO5 unit, assigning to A1g and B2g modes. Natisite remains relatively stable in water with a sodium leaching percentage of lower than 6%. When washing with sulfuric acid solutions, the interlayer spacing of natisite is reduced due to the extensive removal of sodium ions, and an intermediate composed of SiO4 and newly formed TiO6 units may be formed. Moreover, after washing with water and acid solutions, 95.5%, 63.4%, and 35.2% of Na, Si, and Ti in natisite can be leached in total, respectively, resulting in the structural disintegration of natisite.
Research and Evaluation of the Influence of the Construction of the Gate and the Influence of the Piston Velocity on the Distribution of Gases into the Volume of the Casting
Authors: Majerník Ján , Gašpár Štefan , Husár Jozef , Paško Ján , Kolínský Jan
Published: April 2021

Distribution of gasses to the cast volume and volume of pores can be maintained within the acceptable limits by means of correct setting of technological parameters of casting and by selection of suitable structure and gating system arrangement. The main idea of this paper solves the issue of suitability of die casting adjustment—i.e., change of technological parameters or change of structural solution of the gating system—with regards to inner soundness of casts produced in die casting process. Parameters which were compared included height of a gate and velocity of a piston. The melt velocity in the gate was used as a correlating factor between the gate height and piston velocity. The evaluated parameter was gas entrapment in the cast at the end of the filling phase of die casting cycle and at the same time percentage of porosity in the samples taken from the main runner. On the basis of the performed experiments it was proved that the change of technological parameters, particularly of pressing velocity of the piston, directly influences distribution of gasses to the cast volume.
Improving the Corrosion Resistance of Wrought ZM21 Magnesium Alloys by Plasma Electrolytic Oxidation and Powder Coating
Authors: Ballam Lavanya Rani , Arab Hamed , Bestetti Massimiliano , Franz Silvia , Masi Giulia , Sola Ramona , Donati Lorenzo , Martini Carla
Published: April 2021

Plasma Electrolytic Oxidation (PEO) was applied to extruded ZM21 Mg alloys to improve their corrosion resistance in a chloride-containing environment. PEO was carried out in DC mode and voltage control in a fluoride-free electrolyte. Potentiodynamic polarization tests in 3.5 wt.% NaCl aqueous solution and neutral salt spray (NSS) tests were carried out. Microstructural and profilometric characterization, as well as NSS tests were performed in different conditions: (i) bare ZM21, (ii) PEO-treated ZM21, (iii) powder-coated ZM21 (without PEO interlayer), and (iv) PEO-treated ZM21 with powder coating top layer (carboxyl-functionalized polyester resin). The PEO + powder coating double layer was identified as the best-performing corrosion protection.
Influence of Groundwater pH on Water Absorption and Waterproofness of Polymer Modified Bituminous Thick Coatings
Authors: Francke Barbara , Wichowska Maria
Published: April 2021

Polymer modified bituminous thick coatings are increasingly used in the construction industry to protect underground parts of buildings from groundwater. When assessing their durability, one vital issue related to their functional properties is the influence of water absorption on the waterproofness of the applied solution as a result of the action of groundwater with different pH values. As part of the research, the water absorption of the products in question was assessed using the method of total immersion in water with pH of 4.0, 7.0 and 7.5 as well as comparatively, as a result of one-way exposure to demineralized water under successively increasing pressure up to 0.5 MPa. The moisture susceptibility of the coatings was assessed both concerning the local surface damage and the continuous waterproofing coating. It was established that the coatings show the highest water absorption when the water pH is 4.0, which simulates the groundwater aggressiveness on construction products. It was proven that moisture absorbed by the coatings is retained within this layer and is not transferred to the substrate on which the coatings are laid. It was also found that water in contact with the tested coatings changes its reaction to alkaline, which can result in contamination of groundwater in the area of waterproofing coating. A modification of the method of assessing the water absorption of polymer modified bituminous thick coatings was proposed, taking into account their use in conditions of use.
Electro-Optical and Photo Stabilization Study of Nematic Ternary Mixture
Authors: Kalbarczyk Aleksandra , Bennis Noureddine , Herman Jakub , Jaroszewicz Leszek R. , Kula Przemysław
Published: April 2021

Liquid crystal materials composed of mixed nematic compounds find broad use in liquid crystal displays and photonic applications. A ternary mixture formed from three different nematic compounds shows peculiar behavior such as tunable electro-optical properties dependent on the frequency of the driving voltage. The paper presents an analysis of the response time and phase retardation of a frequency tunable nematic liquid crystal mixture (under code name 5005). This material possesses high birefringence (Δn = 0.32 at 633 nm) as well as high dielectric anisotropy (Δε = 6.3 at 100 Hz). The unique property of the 5005 mixture is frequency-controlled phase modulation, as in a dual frequency liquid crystal, while dielectric anisotropy goes to zero instead of being negative at high frequencies. For each component of the mixture, details on mesomorphic properties and their role in the formulation of the mixture are reported. The 5005 mixture was characterized by multiple investigation techniques, such as temperature dependence dielectric anisotropy, transmittance measurements image polarizing microscopy, and UV stability.
Physical and Numerical Modeling of the Slag Splashing Process
Authors: Sinelnikov Viktor , Szucki Michał , Merder Tomasz , Pieprzyca Jacek , Kalisz Dorota
Published: April 2021

The influence of technological factors on the process of slag splashing was analyzed in the paper. The problems were solved in several stages using our own and commercial calculation programs and laboratory tests. Based on the performed calculations and simulations, factors affecting the slag splashing were determined. It was observed that the high efficiency of the process can be achieved by optimizing numerous technological parameters, e.g., flow parameters, pressure, and temperature of the nitrogen stream, height and angle of the lance position, as well as slag height into which the gas stream enters and MgO consumption. In addition, the chemical and mineralogical composition of the slag and its physicochemical parameters should be also considered. The obtained results of numerical simulations of slag splashing in the oxygen converter coincide with the results of experiments carried out using the physical model of oxygen converter. This means that the simulations well represent the real course of the slag splashing process for the studied variants.
Special Issue: Supplementary Cementitious Materials in Concrete, Part I
Authors: Fantilli Alessandro P. , Jóźwiak-Niedźwiedzka Daria
Published: April 2021

The environmental impact of the Portland cement production and the large use of cement-based building materials is a growing problem [...]
Numerical Investigation of MHD Pulsatile Flow of Micropolar Fluid in a Channel with Symmetrically Constricted Walls
Authors: Ali Amjad , Umar Muhammad , Abbas Zaheer , Shahzadi Gullnaz , Bukhari Zainab , Saleem Arshad
Published: April 2021

This article presented an analysis of the pulsatile flow of non-Newtonian micropolar (MP) fluid under Lorentz force’s effect in a channel with symmetrical constrictions on the walls. The governing equations were first converted into the vorticity–stream function form, and a finite difference-based solver was used to solve it numerically on a Cartesian grid. The impacts of different flow controlling parameters, including the Hartman number, Strouhal number, Reynolds number, and MP parameter on the flow profiles, were studied. The wall shear stress (WSS), axial, and micro-rotation velocity profiles were depicted visually. The streamlines and vorticity patterns of the flow were also sketched. It is evident from the numerical results that the flow separation region near constriction as well as flattening of the axial velocity component is effectively controlled by the Hartmann number. At the maximum flow rate, the WSS attained its peak. The WSS increased in both the Hartmann number and Reynolds number, whereas it declined with the higher values of the MP parameter. The micro-rotation velocity increased in the Reynolds number, and it declined with increment in the MP parameter.
Evolving Deep Learning Convolutional Neural Networks for Early COVID-19 Detection in Chest X-ray Images
Authors: Khishe Mohammad , Caraffini Fabio , Kuhn Stefan
Published: April 2021

This article proposes a framework that automatically designs classifiers for the early detection of COVID-19 from chest X-ray images. To do this, our approach repeatedly makes use of a heuristic for optimisation to efficiently find the best combination of the hyperparameters of a convolutional deep learning model. The framework starts with optimising a basic convolutional neural network which represents the starting point for the evolution process. Subsequently, at most two additional convolutional layers are added, at a time, to the previous convolutional structure as a result of a further optimisation phase. Each performed phase maximises the the accuracy of the system, thus requiring training and assessment of the new model, which gets gradually deeper, with relevant COVID-19 chest X-ray images. This iterative process ends when no improvement, in terms of accuracy, is recorded. Hence, the proposed method evolves the most performing network with the minimum number of convolutional layers. In this light, we simultaneously achieve high accuracy while minimising the presence of redundant layers to guarantee a fast but reliable model. Our results show that the proposed implementation of such a framework achieves accuracy up to 99.11%, thus being particularly suitable for the early detection of COVID-19.
Total Synthesis and Structural Reassignment of Laingolide A
Authors: Wu Fusong , Zhang Tao , Yu Jie , Guo Yian , Ye Tao
Published: April 2021

The asymmetric total synthesis of four diastereomers of laingolide A was achieved, which led to the unambiguous assignment of the stereochemistry of the natural product. The salient features of the convergent, fully stereocontrolled approach were a copper-catalysed stereospecific Kumada-type coupling, a Julia-Kocienski olefination and an RCM/alkene migration sequence to access the desired macrocyclic enamide.
The Marine Natural Product Furospinulosin 1 Induces Apoptosis in MDA-MB-231 Triple Negative Breast Cancer Cell Spheroids, But Not in Cells Grown Traditionally with Longer Treatment
Authors: Guzmán Esther A. , Pitts Tara P. , Winder Priscilla L. , Wright Amy E.
Published: April 2021

Cancer cells grown in spheroid conditions interact with each other and the extracellular matrix, providing a better representation of the in vivo environment than two-dimensional cultures and are a more clinically relevant model. A discrete screening of genetically diverse marine samples in the spheroid assay led to the identification of a novel activity for the known compound furospinulosin 1. This compound shows activity against MDA-MB-231 triple negative breast cancer cells grown as spheroids and treated for 24 or 48 h. No cytotoxicity was seen in traditional two-dimensional adherent cultures treated for a longer time (72 h). A reverse phase protein array (RPPA) confirmed the limited activity of the compound in cells grown traditionally and revealed changes in protein expression when cells are grown as spheroids that are associated with better clinical prognosis. Analysis of the RPPA data through the Broad institute’s connectivity map suggested the hypothesis that furospinulosin 1 functions as an MEK inhibitor. Analysis of the RPPA data through STRING supports the apoptosis observed. The selectivity exhibited by furospinulosin 1 for triple negative breast cancer cells only when grown as spheroids makes it an interesting compound with strong therapeutic potential that merits further study.
A Lymphoid Organ Specific Anti-Lipopolysaccharide Factor from Litopenaeus vannamei Exhibits Strong Antimicrobial Activities
Authors: Sun Mingzhe , Li Shihao , Lv Xinjia , Xiang Jianhai , Lu Yuanan , Li Fuhua
Published: April 2021

Different shrimp species are known to possess apparent distinct resistance to different pathogens in aquaculture. However, the molecular mechanism underlying this finding still remains unknown. One kind of important antimicrobial peptides, anti-lipopolysaccharide factors (ALF), exhibit broad-spectrum antimicrobial activities. Here, we reported a newly identified ALF from the shrimp Litopenaeus vannamei and compared the immune function with its counterpart in the shrimp Fenneropenaeus chinensis. The ALF, designated as LvALF8, was specifically expressed in the lymphoid organ of L. vannamei. The expression level of LvALF8 was apparently changed after white spot syndrome virus (WSSV) or Vibrio parahaemolyticus challenges. The synthetic LBD peptide of LvALF8 (LvALF8-LBD) showed strong antibacterial activities against most tested Gram-negative and Gram-positive bacteria. LvALF8-LBD could also inhibit the in vivo propagation of WSSV similar as FcALF8-LBD, the LBD of LvALF8 counterpart in F. chinensis. However, LvALF8-LBD and FcALF8-LBD exhibited apparently different antibacterial activity against V. parahaemolyticus, the main pathogen causing acute hepatopancreatic necrosis disease (AHPND) of affected shrimp. A structural analysis showed that the positive net charge and amphipathicity characteristics of LvALF8-LBD peptide were speculated as two important components for its enhanced antimicrobial activity compared to those of FcALF8-LBD. These new findings may not only provide some evidence to explain the distinct disease resistance among different shrimp species, but also lay out new research ground for the testing and development of LBD-originated antimicrobial peptides to control of shrimp diseases.
Detection of KPC, NDM and VIM-Producing Organisms Directly from Rectal Swabs by a Multiplex Lateral Flow Immunoassay
Authors: Vasilakopoulou Alexandra , Karakosta Polyxeni , Vourli Sophia , Kalogeropoulou Eleni , Pournaras Spyros
Published: April 2021

We report a preliminary evaluation of the NG-Test CARBA 5 immunochromatographic assay for detecting carbapenemases directly from rectal swabs on the same day of sampling. Thirty fecal swabs were examined for carbapenemase-producing organisms (CPOs) by conventional culture, PCR, and NG-Test CARBA 5. Each sample was tested by the immunochromatographic assay five times, including direct testing and incubation in trypticase soy broth for 1, 2, 3, and 4 h. Twenty patients yielded CPOs by culture. Immunochromatographic and PCR results were concordant and detected the same 25 carbapenemases (11 KPC, 8 VIM, and 6 NDM). In five cases, we detected co-carriage of KPC and VIM. Compared with PCR, the sensitivity of NG-Test CARBA 5 for the detection of KPC, VIM, and NDM was 80% without incubation, 88% with one hour, 92% with two, and 100% with three hours incubation, while specificity was 100% for all time points. All samples containing adequate fecal content were detected by NG-Test CARBA 5 concordantly with PCR, without incubation. NG-Test CARBA 5 is a reliable test that rapidly detects the presence of carbapenemases at the same day of sampling, directly from rectal swabs. It thus provides early information to guide antimicrobial treatment and infection control interventions.
Re-Emergence of Salmonellosis in Hog Farms: Outbreak and Bacteriological Characterization
Authors: Meneguzzi Mariana , Pissetti Caroline , Rebelatto Raquel , Trachsel Julian , Kuchiishi Suzana Satomi , Reis Adrienny Trindade , Guedes Roberto Maurício Carvalho , Leão Joice Aparecida , Reichen Caroline , Kich Jalusa Deon
Published: April 2021

Clinical salmonellosis has been increasing significantly in Brazil in recent years. A total of 130 outbreaks distributed among 10 swine-producing states were investigated. One representative Salmonella isolate from each outbreak was characterized through serotyping, antimicrobial resistance profiles, PFGE, and WGS. From 130 outbreaks: 50 were enteric, 48 were septicemic, 17 cases were characterized as hepato-biliary invasive, 13 as nodal and two were not classified. The most prevalent serovars were a monophasic variant of S. typhimurium (55/130), Choleraesuis (46/130), and Typhimurium (14/130). Most of the strains (86.92%) demonstrated a high rate of multi-drug resistance. The identification of a major Choleraesuis clonal group in several Brazilian states sharing the same resistance genes suggested that these strains were closely related. Six strains from this clonal group were sequenced, revealing the same ST-145 and 11 to 47 different SNPs. The detected plasmid type showed multiple marker genes as RepA_1_pKPC-CAV1321, the first to be reported in Salmonella. All AMR genes detected in the genomes were likely present on plasmids, and their phenotype was related to genotypic resistance genes. These findings reveal that salmonellosis is endemic in the most important pig-producing states in Brazil, emphasizing the need to make data available to aid in reducing its occurrence.
Effects of Essential Oils of Elettaria cardamomum Grown in India and Guatemala on Gram-Negative Bacteria and Gastrointestinal Disorders
Authors: Alam Aftab , Rehman Najeeb Ur , Ansari Mohd Nazam , Palla Amber Hanif
Published: April 2021

The present study examined the chemical composition and antimicrobial and gastrointestinal activity of the essential oils of Elettaria cardamomum (L.) Maton harvested in India (EC-I) and Guatemala (EC-G). Monoterpenes were present in higher concentration in EC-I (83.24%) than in EC-G (73.03%), whereas sesquiterpenes were present in a higher concentration in EC-G (18.35%) than in EC-I (9.27%). Minimum inhibitory concentrations (MICs) of 0.5 and 0.25 mg/mL were demonstrated against Pseudomonas aeruginosa in EC-G and EC-I, respectively, whereas MICs of 1 and 0.5 mg/mL were demonstrated against Escherichia coli in EC-G and EC-I, respectively. The treatment with control had the highest kill-time potential, whereas the treatment with oils had shorter kill-time. EC-I was observed to be more potent in the castor oil-induced diarrhea model than EC-G. At 100 and 200 mg/kg, P.O., EC-I exhibited 40% and 80% protection, respectively, and EC-G exhibited 20% and 60% protection, respectively, in mice, whereas loperamide (10 mg/kg, i.p., positive control) exhibited 100% protection. In the in vitro experiments, EC-I inhibited both carbachol (CCh, 1 µM) and high K+ (80 mM)-induced contractions at significantly lower concentrations than EC-G. Thus, EC-I significantly inhibited P. aeruginosa and E. coli and exhibited more potent antidiarrheal and antispasmodic effects than EC-G.
A Chewable Cure “Kanna”: Biological and Pharmaceutical Properties of Sceletium tortuosum
Authors: Manganyi Madira Coutlyne , Bezuidenhout Cornelius Carlos , Regnier Thierry , Ateba Collins Njie
Published: April 2021

Sceletium tortuosum (L.) N.E.Br. (Mesembryanthemaceae), commonly known as kanna or kougoed, is an effective indigenous medicinal plant in South Africa, specifically to the native San and Khoikhoi tribes. Today, the plant has gained strong global attraction and reputation due to its capabilities to promote a sense of well-being by relieving stress with calming effects. Historically, the plant was used by native San hunter-gatherers and Khoi people to quench their thirst, fight fatigue and for healing, social, and spiritual purposes. Various studies have revealed that extracts of the plant have numerous biological properties and isolated alkaloids of Sceletium tortuosum are currently being used as dietary supplements for medicinal purposes and food. Furthermore, current research has focused on the commercialization of the plant because of its treatment in clinical anxiety and depression, psychological and psychiatric disorders, improving mood, promoting relaxation and happiness. In addition, several studies have focused on the isolation and characterization of various beneficial bioactive compounds including alkaloids from the Sceletium tortuosum plant. Sceletium was reviewed more than a decade ago and new evidence has been published since 2008, substantiating an update on this South African botanical asset. Thus, this review provides an extensive overview of the biological and pharmaceutical properties of Sceletium tortuosum as well as the bioactive compounds with an emphasis on antimicrobial, anti-inflammatory, anti-oxidant, antidepressant, anxiolytic, and other significant biological effects. There is a need to critically evaluate the bioactivities and responsible bioactive compounds, which might assist in reinforcing and confirming the significant role of kanna in the promotion of healthy well-being in these stressful times.
Green Synthesis and Incorporation of Sericin Silver Nanoclusters into Electrospun Ultrafine Cellulose Acetate Fibers for Anti-Bacterial Applications
Authors: Mehdi Mujahid , Qiu Huihui , Dai Bing , Qureshi Raja Fahad , Hussain Sadam , Yousif Muhammad , Gao Peng , Khatri Zeeshan
Published: April 2021

Fiber based antibacterial materials have gained an enormous attraction for the researchers in these days. In this study, a novel Sericin Encapsulated Silver Nanoclusters (sericin-AgNCs) were synthesized through single pot and green synthesis route. Subsequently these sericin-AgNCs were incorporated into ultrafine electrospun cellulose acetate (CA) fibers for assessing the antibacterial performance. The physicochemical properties of sericin-AgNCs/CA composite fibers were investigated by transmission electron microscopy (TEM), field emission electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FTIR) and wide X-ray diffraction (XRD). The antibacterial properties of sericin-AgNCs/CA composite fibers against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were systematically evaluated. The results showed that sericin-AgNCs incorporated in ultrafine CA fibers have played a vital role for antibacterial activity. An amount of 0.17 mg/mL sericin-AgNCs to CA fibers showed more than 90% results and elevated upto >99.9% with 1.7 mg/mL of sericin-AgNCs against E. coli. The study indicated that sericin-AgNCs/CA composite confirms an enhanced antibacterial efficiency, which could be used as a promising antibacterial product.
RETRACTED: Hybrid Application of Nanoparticles and Polymer in Enhanced Oil Recovery Processes
Authors: Hu Yanqiu , Zhao Zeyuan , Dong Huijie , Vladimirovna Mikhailova Maria , Davarpanah Afshin
Published: April 2021

Nowadays, the addition of nanoparticles to polymer solutions would be of interest; however, the feasible property of nanoparticles and their impact on oil recovery has not been investigated in more detail. This study investigates the rheology and capillary forces (interfacial tension and contact angle) of nanoparticles in the polymer performances during oil recovery processes. Thereby, a sequential injection of water, polymer, and nanoparticles; Nanosilica (SiO2) and nano-aluminium oxide (Al2O3) was performed to measure the oil recovery factor. Retention decrease, capillary forces reduction, and polymer viscoelastic behavior increase have caused improved oil recovery due to the feasible mobility ratio of polymer–nanoparticle in fluid loss. The oil recovery factor for polymer flooding, polymer–Al2O3, and polymer–SiO2 is 58%, 63%, and 67%, respectively. Thereby, polymer–SiO2 flooding would provide better oil recovery than other scenarios that reduce the capillary force due to the structural disjoining pressure. According to the relative permeability curves, residual oil saturation (Sor) and water relative permeability (Krw) are 29% and 0.3%, respectively, for polymer solution; however, for the polymer–nanoparticle solution, Sor and Krw are 12% and 0.005%, respectively. Polymer treatment caused a dramatic decrease, rather than the water treatment effect on the contact angle. The minimum contact angle for water and polymer treatment are about 21 and 29, respectively. The contact angle decrease for polymer treatment in the presence of nanoparticles related to the surface hydrophilicity increase. Therefore, after 2000 mg L−1 of SiO2 concentration, there are no significant changes in contact angle.
Novel Organochlorinated Xerogels: From Microporous Materials to Ordered Domains
Authors: Cruz-Quesada Guillermo , Espinal-Viguri Maialen , López-Ramón María Victoria , Garrido Julián J.
Published: April 2021

Hybrid silica xerogels combine the properties of organic and inorganic components in the same material, making them highly promising and versatile candidates for multiple applications. They can be tailored for specific purposes through chemical modifications, and the consequent changes in their structures warrant in-depth investigation. We describe the synthesis of three new series of organochlorinated xerogels prepared by co-condensation of tetraethyl orthosilicate (TEOS) and chloroalkyltriethoxysilane (ClRTEOS; R = methyl [M], ethyl [E], or propyl [P]) at different molar ratios. The influence of the precursors on the morphological and textural properties of the xerogels was studied using 29Si NMR (Nuclear Magnetic Resonance), FTIR (Fourier-Transform Infrared Spectroscopy), N2, and CO2 adsorption, XRD (X-ray Diffraction), and FE-SEM (Field-Emission Scanning Electron Microscopy). The structure and morphology of these materials are closely related to the nature and amount of the precursor, and their microporosity increases proportionally to the molar percentage of ClRTEOS. In addition, the influence of the chlorine atom was investigated through comparison with their non-chlorinated analogues (RTEOS, R = M, E, or P) prepared in previous studies. The results showed that a smaller amount of precursor was needed to detect ordered domains (ladders and T8 cages) in the local structure. The possibility of coupling self-organization with tailored porosity opens the way to novel applications for this type of organically modified silicates.
Enhanced Cytotoxic Activity of Docetaxel-Loaded Silk Fibroin Nanoparticles against Breast Cancer Cells
Authors: Al Saqr Ahmed , Wani Shahid Ud Din , Gangadharappa H. V. , Aldawsari Mohammed F. , Khafagy El-Sayed , Lila Amr S. Abu
Published: April 2021

Despite decades of research, breast cancer therapy remains a great challenge. Docetaxel is an antimicrotubule agent that is effectively used for the treatment of breast cancer. However, its clinical use is significantly hampered by its low water solubility and systemic toxicity. The current study was designed to prepare docetaxel (DXL)-loaded silk-fibroin-based nanoparticles (SF-NPs) and to screen their potential antitumor activity against breast cancer cell lines. DXL-loaded SF-NPs were prepared using a nanoprecipitation technique and were evaluated for particle size, zeta potential, entrapment efficiency, and in vitro release profile. In addition, DXL-loaded SF-NPs were screened for in vitro cytotoxicity, cellular uptake, and apoptotic potential against MCF-7 and MDA-MB-231 breast cancer cell lines. The prepared DXL-loaded SF-NPs were 178 to 198 nm in diameter with a net negative surface charge and entrapment efficiency ranging from 56% to 72%. In vitro release studies exhibited a biphasic release profile of DXL from SF-NPs with sustained drug release for 72 h. In vitro cell studies revealed that entrapment of DXL within SF-NPs significantly improved cytotoxic potential against breast cancer cell lines, compared to the free drug, and enhanced cellular uptake of DXL by breast cancer cells. Furthermore, the accumulation in the G2/M phase was significantly higher in cells treated with DXL-loaded SF-NPs than in cells treated with free DXL. Collectively, the superior antitumor activities of DXL-loaded SF-NPs against breast cancer cells, compared to free DXL, could be ascribed to improved apoptosis and cell cycle arrest. Our results highlighted the feasibility of using silk fibroin nanoparticles as a nontoxic biocompatible delivery vehicle for enhanced therapeutic outcomes in breast cancer.
Seasonal and Diurnal Variations in Cloud-Top Phase over the Western North Pacific during 2017–2019
Authors: Zhuge Xiaoyong , Zou Xiaolei , Li Xin , Tang Fei , Yao Bin , Yu Lu
Published: April 2021

The cloud-top-phase climatology over the western North Pacific (WNP) has received little attention. Using 3 years (2017–2019) of cloud-top-phase products from the Advanced Himawari Imager onboard the Japanese Himawari-8 satellite, this study examines the seasonal and diurnal variations in the cloud-top phase over the WNP. Results show that over the low- and mid-latitude maritime regions, ice (water) clouds occur more (less) frequently during boreal winter than summer. Water clouds are more likely to be related to moisture conditions in the lower troposphere than to the underlying sea surface temperature. Owing to the combined effects of moist air mass transport and ocean currents (topography), the WNP region east of Hokkaido (the Sichuan Basin) has a high frequency of water clouds in summer (winter). Furthermore, supercooled water cloud populations have a clear seasonal cycle. The fraction of water clouds that are supercooled appears to be modulated by the near-surface air temperature. A diurnal cycle is seen in ice-cloud populations, which are highest in the late afternoon over both ocean and land except for the Sichuan Basin where summer nocturnal precipitation is typical. The occurrences of continental water clouds peak at noon in summer but early morning (around sunrise) in winter. An increase in the frequency of continental summer water clouds around noon is found to be associated with variations in both the cloud-top elevation of already-existing water clouds and new formations of boundary-layer clouds.
Supervised Detection of Ionospheric Scintillation in Low-Latitude Radio Occultation Measurements
Authors: Ludwig-Barbosa Vinícius , Sievert Thomas , Carlström Anders , Pettersson Mats I. , Vu Viet T. , Rasch Joel
Published: April 2021

Global Navigation Satellite System (GNSS) Radio Occultation (RO) has provided high-quality atmospheric data assimilated in Numerical Weather Prediction (NWP) models and climatology studies for more than 20 years. In the satellite–satellite GNSS-RO geometry, the measurements are susceptible to ionospheric scintillation depending on the solar and geomagnetic activity, seasons, geographical location and local time. This study investigates the application of the Support Vector Machine (SVM) algorithm in developing an automatic detection model of F-layer scintillation in GNSS-RO measurements using power spectral density (PSD). The model is intended for future analyses on the influence of space weather and solar activity on RO data products over long time periods. A novel data set of occultations is used to train the SVM algorithm. The data set is composed of events at low latitudes on 15–20 March 2015 (St. Patrick’s Day geomagnetic storm, high solar flux) and 14–19 May 2018 (quiet period, low solar flux). A few conditional criteria were first applied to a total of 5340 occultations to define a set of 858 scintillation candidates. Models were trained with scintillation indices and PSDs as training features and were either linear or Gaussian kernel. The investigations also show that besides the intensity PSD, the (excess) phase PSD has a positive contribution in increasing the detection of true positives.
Detection of Negative Stress through Spectral Features of Electroencephalographic Recordings and a Convolutional Neural Network
Authors: Martínez-Rodrigo Arturo , García-Martínez Beatriz , Huerta Álvaro , Alcaraz Raúl
Published: April 2021

In recent years, electroencephalographic (EEG) signals have been intensively used in the area of emotion recognition, partcularly in distress identification due to its negative impact on physical and mental health. Traditionally, brain activity has been studied from a frequency perspective by computing the power spectral density of the EEG recordings and extracting features from different frequency sub-bands. However, these features are often individually extracted from single EEG channels, such that each brain region is separately evaluated, even when it has been corroborated that mental processes are based on the coordination of different brain areas working simultaneously. To take advantage of the brain’s behaviour as a synchronized network, in the present work, 2-D and 3-D spectral images constructed from common 32 channel EEG signals are evaluated for the first time to discern between emotional states of calm and distress using a well-known deep-learning algorithm, such as AlexNet. The obtained results revealed a significant improvement in the classification performance regarding previous works, reaching an accuracy about 84%. Moreover, no significant differences between the results provided by the diverse approaches considered to reconstruct 2-D and 3-D spectral maps from the original location of the EEG channels over the scalp were noticed, thus suggesting that these kinds of images preserve original spatial brain information.