bluuebunny/crossref_metadata_2025 huggingface dataset:
New Insights into Curcumin- and Resveratrol-Mediated Anti-Cancer Effects
Authors: Arena Andrea , Romeo Maria Anele , Benedetti Rossella , Masuelli Laura , Bei Roberto , Gilardini Montani Maria Saveria , Cirone Mara
Published: October 2021

Curcumin and resveratrol are bioactive natural compounds displaying anti-inflammatory, anti-oxidant and anti-cancer properties. In this study, we compared the cytotoxic effects of these molecules and the molecular mechanisms involved against Her-2/neu-positive breast and salivary cancer cell lines. We found that both curcumin and resveratrol were efficient in reducing cancer cell survival and that they differently affected autophagy, ROS and activation of the PI3K/AKT/mTOR pathway. Moreover, we found that resveratrol and curcumin in combination exerted a stronger cytotoxic effect in correlation with the induction of a stronger ER stress and the upregulation of pro-death UPR molecule CHOP. This effect also correlated with the induction of pro-survival autophagy by curcumin and its inhibition by resveratrol. In conclusion, this study unveils new molecular mechanisms underlying the anti-cancer effects of resveratrol, curcumin and their combination, which can help to design new therapeutic strategies based on the use of these polyphenols.
Evidence That a TRPA1-Mediated Murine Model of Temporomandibular Joint Pain Involves NLRP3 Inflammasome Activation
Authors: Kodji Xenia , Kee Zizheng , McKenna Robyn , de Sousa Valente Joao , Ravenscroft Harriet , McMillan Hayley , Gamble John , Dombrowski Yvonne , Moynagh Paul , Brough David , Lundy Fionnuala T. , Brain Susan D. , El Karim Ikhlas A.
Published: October 2021

This study investigates the role of transient receptor potential ankyrin 1 (TRPA1) in murine temporomandibular joint (TMJ) inflammatory hyperalgesia and the influence of the NLR family pyrin domain-containing 3 (NLRP3) inflammasome. Two distinct murine models of TMJ pain and inflammation (zymosan and CFA) were established. Spontaneous pain-like behaviours were observed as unilateral front paw cheek wipes. Ipsilateral cheek blood flow was used as a measure of ongoing inflammation, which, to our knowledge, is a novel approach to assessing real-time inflammation in the TMJ. Joint tissue and trigeminal ganglia were collected for ex vivo investigation. Both zymosan and CFA induced a time-dependent increase in hyperalgesia and inflammation biomarkers. Zymosan induced a significant effect after 4 h, correlating with a significantly increased IL-1β protein expression. CFA (50 µg) induced a more sustained response. The TRPA1 receptor antagonist A967079 significantly inhibited hyper-nociception. The NLRP3 inhibitor MCC950 similarly inhibited hyper-nociception, also attenuating inflammatory markers. In the trigeminal ganglia, CFA-induced CGRP expression showed trends of inhibition by A967079, whilst lba1 immunofluorescence was significantly inhibited by A967079 and MCC950, where the effect of TRPA1 inhibition lasted up to 14 days. Our results show that stimulation of TRPA1 is key to the TMJ pain. However, the inflammasome inhibitor exhibited similar properties in attenuating these pain-like behaviours, in addition to some inflammatory markers. This indicates that in addition to the therapeutic targeting of TRPA1, NLRP3 inhibition may provide a novel therapeutic strategy for TMJ inflammation and pain.
Artepillin C Reduces Allergic Airway Inflammation by Induction of Monocytic Myeloid-Derived Suppressor Cells
Authors: Martins Núbia Sabrina , de Campos Fraga-Silva Thais Fernanda , Correa Giseli Furlan , Boko Mèdéton Mahoussi Michaël , Ramalho Leandra Naira Zambelli , Rodrigues Débora Munhoz , Hori Juliana Issa , Costa Diego Luis , Bastos Jairo Kenupp , Bonato Vânia Luiza Deperon
Published: October 2021

Propolis is a natural product produced by bees that is primarily used in complementary and alternative medicine and has anti-inflammatory, antibacterial, antiviral, and antitumoral biological properties. Some studies have reported the beneficial effects of propolis in models of allergic asthma. In a previous study, our group showed that green propolis treatment reduced airway inflammation and mucus secretion in an ovalbumin (OVA)-induced asthma model and resulted in increased regulatory T cells (Treg) and polymorphonuclear myeloid-derived suppressor cells (PMN-MDSC) frequencies in the lungs, two leukocyte populations that have immunosuppressive functions. In this study, we evaluated the anti-inflammatory effects of artepillin C (ArtC), the major compound of green propolis, in the context of allergic airway inflammation. Our results show that ArtC induces in vitro differentiation of Treg cells and monocytic MDSC (M-MDSC). Furthermore, in an OVA-induced asthma model, ArtC treatment reduced pulmonary inflammation, eosinophil influx to the airways, mucus and IL-5 secretion along with increased frequency of M-MDSC, but not Treg cells, in the lungs. Using an adoptive transfer model, we confirmed that the effect of ArtC in the reduction in airway inflammation was dependent on M-MDSC. Altogether, our data show that ArtC exhibits an anti-inflammatory effect and might be an adjuvant therapy for allergic asthma.
Surface Treatment of Glass Vials for Lyophilization: Implications for Vacuum-Induced Surface Freezing
Authors: Regis Francesco , Arsiccio Andrea , Bourlès Erwan , Scutellà Bernadette , Pisano Roberto
Published: October 2021

Freeze-drying is commonly used to increase the shelf-life of pharmaceuticals and biopharmaceuticals. Freezing represents a crucial phase in the freeze-drying process, as it determines both cycle efficiency and product quality. For this reason, different strategies have been developed to allow for a better control of freezing, among them, the so-called vacuum-induced surface freezing (VISF), which makes it possible to trigger nucleation at the same time in all the vials being processed. We studied the effect of different vial types, characterized by the presence of hydrophilic (sulfate treatment) or hydrophobic (siliconization and TopLyo Si–O–C–H layer) inner coatings, on the application of VISF. We observed that hydrophobic coatings promoted boiling and blow-up phenomena, resulting in unacceptable aesthetic defects in the final product. In contrast, hydrophilic coatings increased the risk of fogging (i.e., the undesired creeping of the product upward along the inner vial surface). We also found that the addition of a surfactant (Tween 80) to the formulation suppressed boiling in hydrophobic-coated vials, but it enhanced the formation of bubbles. This undesired bubbling events induced by the surfactant could, however, be eliminated by a degassing step prior to the application of VISF. Overall, the combination of degasification and surfactant addition seems to be a promising strategy for the successful induction of nucleation by VISF in hydrophobic vials.
In Vitro Pharmacokinetic/Pharmacodynamic Modelling and Simulation of Amphotericin B against Candida auris
Authors: Caballero Unai , Eraso Elena , Pemán Javier , Quindós Guillermo , Vozmediano Valvanera , Schmidt Stephan , Jauregizar Nerea
Published: October 2021

The aims of this study were to characterize the antifungal activity of amphotericin B against Candida auris in a static in vitro system and to evaluate different dosing schedules and MIC scenarios by means of semi-mechanistic pharmacokinetic/pharmacodynamic (PK/PD) modelling and simulation. A two-compartment model consisting of a drug-susceptible and a drug-resistant subpopulation successfully characterized the time-kill data and a modified Emax sigmoidal model best described the effect of the drug. The model incorporated growth rate constants for both subpopulations, a death rate constant and a transfer constant between both compartments. Additionally, the model included a parameter to account for the delay in growth in the absence or presence of the drug. Amphotericin B displayed a concentration-dependent fungicidal activity. The developed PK/PD model was able to characterize properly the antifungal activity of amphotericin B against C. auris. Finally, simulation analysis revealed that none of the simulated standard dosing scenarios of 0.6, 1 and 1.5 mg/kg/day over a week treatment showed successful activity against C. auris infection. Simulations also pointed out that an MIC of 1 mg/L would be linked to treatment failure for C. auris invasive infections and therefore, the resistance rate to amphotericin B may be higher than previously reported.
Early Effects of Low Molecular Weight Heparin Therapy with Soft-Mist Inhaler for COVID-19-Induced Hypoxemia: A Phase IIb Trial
Authors: Erelel Mustafa , Kaskal Mert , Akbal-Dagistan Ozlem , Issever Halim , Dagistanli Ahmet Serhan , Balkanci Hilal , Oguz Merve Sinem , Qarayeva Aygun , Culha Meltem , Erturk Aybige , Basarir Nur Sena , Sahin Gokben , Uresin Ali Yagiz , Araman Ahmet Ogul , Medetalibeyoglu Alpay , Tukek Tufan , Oncul Mustafa Oral , Yildiz-Pekoz Ayca
Published: October 2021

In COVID-19-induced acute respiratory distress syndrome, the lungs are incapable of filling with sufficient air, leading to hypoxemia that results in high mortality among hospitalized patients. In clinical trials, low-molecular-weight heparin was administered via a specially designed soft-mist inhaler device in an investigator initiated, single-center, open-label, phase-IIb clinical trial. Patients with evidently worse clinical presentations were classed as the “Device Group”; 40 patients were given low-molecular-weight heparin via a soft mist inhaler at a dose of 4000 IU per administration, twice a day. The Control Group, also made up of 40 patients, received the standard therapy. The predetermined severity of hypoxemia and the peripheral oxygen saturation of patients were measured on the 1st and 10th days of treatment. The improvement was particularly striking in cases of severe hypoxemia. In the 10-day treatment, low-molecular-weight heparin was shown to significantly improve breathing capability when delivered via a soft-mist inhaler.
Effect of Surfactants and Polymers on the Dissolution Behavior of Supersaturable Tecovirimat-4-Hydroxybenzoic Acid Cocrystals
Authors: Feng Yumiao , Meng Yuanyuan , Tan Fangyun , Lv Lin , Li Zhiping , Wang Yuli , Yang Yang , Gong Wei , Yang Meiyan
Published: October 2021

(1) Background: Pharmaceutical cocrystals have attracted remarkable interest and have been successfully used to enhance the absorption of poorly water-soluble drugs. However, supersaturable cocrystals are sometimes thermodynamically unstable, and the solubility advantages present a risk of precipitation because of the solution-mediated phase transformation (SMPT). Additives such as surfactants and polymers could sustain the supersaturation state successfully, but the effect needs insightful understanding. The aim of the present study was to investigate the roles of surfactants and polymers in the dissolution-supersaturation-precipitation (DSP) behavior of cocrystals. (2) Methods: Five surfactants (SDS, Poloxamer 188, Poloxamer 407, Cremophor RH 40, polysorbate 80) and five polymers (PVP K30, PVPVA 64, HPC, HPMC E5, CMC-Na) were selected as additives. Tecovirimat-4-hydroxybenzoic (TEC-HBA) cocrystals were chosen as a model cocrystal. The TEC-HBA cocrystals were first designed and verified by PXRD, DSC, SEM, and FTIR. The effects of surfactants and polymers on the solubility and dissolution of TEC-HBA cocrystals under sink and nonsink conditions were then investigated. (3) Results: Both the surfactants and polymers showed significant dissolution enhancement effects, and most of the polymers were more effective than the surfactants, according to the longer Tmax and higher Cmax. These results demonstrate that the dissolution behavior of cocrystals might be achieved by the maintained supersaturation effect of the additives. Interestingly, we found a linear relationship between the solubility and Cmax of the dissolution curve for surfactants, while no similar phenomena were found in solutions with polymer. (4) Conclusions: The present study provides a basis for additive selection and a framework for understanding the behavior of supersaturable cocrystals in solution.
Discovery of a Potent Candidate for RET-Specific Non-Small-Cell Lung Cancer—A Combined In Silico and In Vitro Strategy
Authors: Ramesh Priyanka , Shin Woong-Hee , Veerappapillai Shanthi
Published: October 2021

Rearranged during transfection (RET) is a tyrosine kinase oncogenic receptor, activated in several cancers including non-small-cell lung cancer (NSCLC). Multiple kinase inhibitors vandetanib and cabozantinib are commonly used in the treatment of RET-positive NSCLC. However, specificity, toxicity, and reduced efficacy limit the usage of multiple kinase inhibitors in targeting RET protein. Thus, in the present investigation, we aimed to figure out novel and potent candidates for the inhibition of RET protein using combined in silico and in vitro strategies. In the present study, screening of 11,808 compounds from the DrugBank repository was accomplished by different hypotheses such as pharmacophore, e-pharmacophore, and receptor cavity-based models in the initial stage. The results from the different hypotheses were then integrated to eliminate the false positive prediction. The inhibitory activities of the screened compounds were tested by the glide docking algorithm. Moreover, RF score, Tanimoto coefficient, prime-MM/GBSA, and density functional theory calculations were utilized to re-score the binding free energy of the docked complexes with high precision. This procedure resulted in three lead molecules, namely DB07194, DB03496, and DB11982, against the RET protein. The screened lead molecules together with reference compounds were then subjected to a long molecular dynamics simulation with a 200 ns time duration to validate the inhibitory activity. Further analysis of compounds using MM-PBSA and mutation studies resulted in the identification of potent compound DB07194. In essence, a cell viability assay with RET-specific lung cancer cell line LC-2/ad was also carried out to confirm the in vitro biological activity of the resultant compound, DB07194. Indeed, the results from our study conclude that DB07194 can be effectively translated for this new therapeutic purpose, in contrast to the properties for which it was originally designed and synthesized.
Comparison of Surface Functionalization of PLGA Composite to Immobilize Extracellular Vesicles
Authors: Woo Jiwon , Ko Kyoung-Won , Cha Seung-Gyu , Heo Yun , Han Dong Keun
Published: October 2021

Endothelialization by materials provides a promising approach for the rapid re-endothelialization of a cardiovascular implantation. Although previous studies have focused on improving endothelialization through the immobilization of bioactive molecules onto the surface of biodegradable implants, comparative studies of effective surface modification have not yet been reported. Here, we conducted a comparative study on the surface modification of poly(lactide-co-glycolide) (PLGA)-based composites to graft mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) using three different materials, fibronectin (FN), polyethylenimine (PEI), and polydopamine (PDA), which have different bond strengths of ligand–receptor interaction, ionic bond, and covalent bond, respectively. Further in vitro analysis exhibited that MSC-EVs released from all modified films sustainably, but the MSC-EVs grafted onto the surface coated with PEI are more effective than other groups in increasing angiogenesis and reducing the inflammatory responses in endothelial cells. Therefore, the overall results demonstrated that PEI is a desirable coating reagent for the immobilization of MSC-EVs on the surface of biodegradable implants.
Thermal, Mechanical and Chemical Analysis of Poly(vinyl alcohol) Multifilament and Braided Yarns
Authors: Freire Tania F. , Quinaz Tiago , Fertuzinhos Aureliano , Quyền Nguyễn T. , de Moura Marcelo F. S. M. , Martins Marcos , Zille Andrea , Dourado Nuno
Published: October 2021

Poly(vinyl alcohol) (PVA) in multifilament and braided yarns (BY) forms presents great potential for the design of numerous applications. However, such solutions fail to accomplish their requirements if the chemical and thermomechanical behaviour is not sufficiently known. Hence, a comprehensive characterisation of PVA multifilament and three BY architectures (6, 8, and 10 yarns) was performed involving the application of several techniques to evaluate the morphological, chemical, thermal, and mechanical features of those structures. Scanning electron microscopy (SEM) was used to reveal structural and morphological information. Differential thermal analysis (DTA) pointed out the glass transition temperature of PVA at 76 °C and the corresponding crystalline melting point at 210 °C. PVA BY exhibited higher tensile strength under monotonic quasi-static loading in comparison to their multifilament forms. Creep tests demonstrated that 6BY structures present the most deformable behaviour, while 8BY structures are the least deformable. Relaxation tests showed that 8BY architecture presents a more expressive variation of tensile stress, while 10BY offered the least. Dynamic mechanical analysis (DMA) revealed storage and loss moduli curves with similar transition peaks for the tested structures, except for the 10BY. Storage modulus is always four to six times higher than the loss modulus.
A Novel Synergistic Flame Retardant of Hexaphenoxycyclotriphosphazene for Epoxy Resin
Authors: Jiang Jiawei , Huo Siqi , Zheng Yi , Yang Chengyun , Yan Hongqiang , Ran Shiya , Fang Zhengping
Published: October 2021

Hexaphenoxycyclotriphosphazene (HPCP) is a common flame retardant for epoxy resin (EP). To improve the thermostability and fire safety of HPCP-containing EP, we combined UiO66-NH2 (a kind of metal-organic frame, MOF) with halloysite nanotubes (HNTs) by hydrothermal reaction to create a novel synergistic flame retardant (H-U) of HPCP for EP. For the EP containing HPCP and H-U, the initial decomposition temperature (T5%) and the temperature of maximum decomposition rate (Tmax) increased by 11 and 17 °C under nitrogen atmosphere compared with those of the EP containing only HPCP. Meanwhile, the EP containing HPCP and H-U exhibited better tensile and flexural properties due to the addition of rigid nanoparticles. Notably, the EP containing HPCP and H-U reached a V-0 rating in UL-94 test and a limited oxygen index (LOI) of 35.2%. However, with the introduction of H-U, the flame retardant performances of EP composites were weakened in the cone calorimeter test, which was probably due to the decreased height of intumescent residual char.
Clairvoyant Melon Maturity Detection Enabled by Doctor-Blade-Coated Photonic Crystals
Authors: Lu Yi-Cheng , Pan Liang-Cheng , Lei Yao-Wei , Lin Kun-Yi Andrew , Yang Hongta
Published: October 2021

Climacteric fruits are harvested before they are ripened to avoid adverse damages during transport. The unripe fruits can undergo ripening processes associated with rind color changes on exposure to ethanol vapors. Although rind coloration is a common indicator showing fruit maturity, the attribute does not provide reliable assessment of maturity especially for melons. Herein, we report the achievement of sensitive and reversible melon maturity detection using macroporous hydrogel photonic crystals self-assembled by a roll-to-roll compatible doctor-blade-coating technology. The consumption of applied ethanol vapor during melon ripening results in less condensation of ethanol vapor in the pores (250 nm in diameter), leading to a distinct blue-shift of the optical stop band from 572 to 501 nm and an obvious visual colorimetric readout from yellow green to blue. Moreover, the dependence of the color change on Brix value within the melon has also been evaluated in the study.
International legal regulation of electronic document circulation
Authors: KUSHYBEK Saule
Published: October 2021

Electronic documents are a type of document that exists only in digital form. These electronic documents are the information product of the latest electronic information technologies such as Internet technologies, WWW technologies, multimedia. Electronic document circulation is known as a system of electronic document management, the relations between the participants of which are regulated by national law and other regulatory legal acts. On the basis of international legislation and legislation of foreign countries, the analysis of the essence and content of electronic document circulation is carried out, the legal relations that make up this concept are defined, the concepts and use of electronic documents and electronic signatures are studied. The unification of rules on electronic documents and their use in contractual relations are the cause of economic and legal issues. The article examines and conducts a comparative analysis of the features and effectiveness of the laws of United Nations Commission on International Trade Law (UNCITRAL), the directives of the European Union and the Convention laws in the emergence of electronic document management.
Edukacja zdalna w czasie pandemii - perspektywa rodziców i opiekunów
Authors: Dąbrowska Ilona
Published: October 2021

CEL NAUKOWY: Celem artykułu jest poznanie opinii rodziców oraz opiekunów na temat organizacji i przebiegu edukacji zdalnej w czasie pandemii wirusa SARS-CoV-2 w Polsce.PROBLEM I METODY BADAWCZE: W prezentowanym artykule analizom poddano wypowiedzi rodziców odnoszące się do edukacji zdalnej prowadzonej w czasie pandemii. Wykonano analizę dostępnych raportów i publikacji, jak również przeprowadzono badania własne (ankietowe).PROCES WYWODU: Zdefiniowano kluczowe dla analizy pojęcia oraz przedstawiono wynikibadań ankietowych.WYNIKI ANALIZY NAUKOWEJ: Przeprowadzona analiza wykazała nie tylko niską ocenę realizowanych zajęć, ale także wskazała konkretne płaszczyzny, gdzie konieczne jest wprowadzenie nowych rozwiązań, a wręcz systemowego wsparcia merytorycznego czy psychologicznego.WNIOSKI, INNOWACJE, REKOMENDACJE: Przedstawione w pracy wyniki badań potwierdzajątezę o zwiększeniu liczby zadań i obowiązków, które nakłada na rodziców edukacja zdalna. Wynikibadań dostarczają informacji o konkretnych potrzebach, tak objętych zdalną edukacją uczniów, jaki organizujących opiekę w domu rodziców.
Vision-Cloud Data Fusion for ADAS: A Lane Change Prediction Case Study
Authors: Wang Ziran
Published: October 2021

With the rapid development of intelligent vehicles and Advanced Driver-Assistance Systems (ADAS), a new trend is that mixed levels of human driver engagements will be involved in the transportation system. Therefore, necessary visual guidance for drivers is vitally important under this situation to prevent potential risks. To advance the development of visual guidance systems, we introduce a novel vision-cloud data fusion methodology, integrating camera image and Digital Twin information from the cloud to help intelligent vehicles make better decisions. Target vehicle bounding box is drawn and matched with the help of the object detector (running on the ego-vehicle) and position information (received from the cloud). The best matching result, a 79.2% accuracy under 0.7 intersection over union threshold, is obtained with depth images served as an additional feature source. A case study on lane change prediction is conducted to show the effectiveness of the proposed data fusion methodology. In the case study, a multi-layer perceptron algorithm is proposed with modified lane change prediction approaches. Human-in-the-loop simulation results obtained from the Unity game engine reveal that the proposed model can improve highway driving performance significantly in terms of safety, comfort, and environmental sustainability.
A Smart Climatic Control Strategy for Optimizing Vegetable Crop Cultivation in Greenhouse using FBANN
Authors: Shakya Subarna
Published: October 2021

Greenhouses are designed to provide the desired climatic condition for the growth of certain plants to obtain better yield. Most of the greenhouses are developed with adequate windows that allows the natural air to reach the plants to maintain the ideal temperature. The windows are usually operated manually by verifying the greenhouse temperature and the surrounding temperature. In a few cases, the manual operations are extended to control the natural light levels and the humidity inside the greenhouse. In order to improve the performances of such climatic control in a greenhouse, certain automatic systems were developed in recent years. In the proposed work, the operations are controlled using a microcontroller module and a sensor unit. The information collected from the sensors placed inside and outside the greenhouse is forwarded to a feedback gained Artificial Neural Network (FBANN) for making the desirable operation on window and light control modules. The performances of the proposed work is verified with RMSE values observed from the manually operated controller.
ЭМОЦИОНАЛЬНЫЕ ДИСГАРМОНИИ У ДОШКОЛЬНИКОВ В СЕМЬЯХ С РАЗЛИЧНЫМИ ТИПАМИ КОММУНИКАТИВНЫХ ВЗАИМОДЕЙСТВИЙ
Authors: Сердюкова Е.Ф.
Published: October 2021

В статье приведен анализ существующих подходов к изучению эмоциональных деструкций у дошкольников; особое внимание уделено проявлениям агрессивности и причинам ее появления; указывается на особую роль детско-родительских отношений в становлении и развитии личности ребенка. Автор предполагает, что тип коммуникативного взаимодействия оказывает существенное влияние на развитие у дошкольников эмоциональных дисгармоний, и на примере агрессивности подтверждает свои предварительно сформулированные предположения. В ходе проведенного исследования установлено, что типы коммуникативных взаимодействий в семье оказывают существенное влияние на проявление агрессивного поведения ребенка-дошкольника. В частности, статистическая обработка результатов исследования показала значимую устойчивую зависимость между физической агрессией, с одной стороны, и потворствованием, а также воспитательной неуверенностью, – с другой; между вербальной агрессией и потворствованием. Обратная зависимость выявлена между чрезмерностью требований и санкций, с одной стороны, и раздражением, – с другой; подозрительность значимо коррелирует с недостаточностью требований – запретов, неуверенным стилем воспитания, стимулированием детских качеств и фобией утраты ребенка. Враждебность является следствием недостаточности требований-запретов.
Expressar a Interioridade: Os Diários Filmados de Jonas Mekas
Authors: Minau Ramos Tiago Luís
Published: October 2021

Jonas Mekas develops the diary film practice as a way of celebrating and preserving his lived experiences through the act of representing them. In addition to making his life the subject matter of his diary films, Mekas wants his filmic recordings to be traces of his own gestures as he moves ahead in search of glimpses of beauty. Therefore, the diarist adopts a set of techniques, associated with avant-garde cinema, and inserts them in an autobiographical context, with the intention of creating a cinematic language capable of representing his interiority. This essay will analyze the techniques employed by Jonas Mekas and the way in which they attempt to represent the diarist’s self.
Unveiling the mural painting art of Almada Negreiros at the Maritime Stations of Alcântara (Lisbon): diagnosis research of paint layers as a guide for its future conservation
Authors: Gil Milene , Costa Mafalda , Cvetkovic Mila , Bottaini Carlo , Cardoso Ana Margarida , Manhita Ana , Barrocas Dias Cristina , Candeias António
Published: October 2021

This paper reports the diagnostic research of deteriorated paint layers from three mural panels made by Almada Negreiros found in the Alcântara Maritime Station in Lisbon. The aim was to understand the main decay phenomena to aid future conservation works. The methodology comprised in-situ analyses by technical photography in Vis, Vis-RaK and UVF, p-OM and h-EDXRF; micro sampling; OM, SEM-EDS, μ-XRD, μ-Raman, µ-FT-IR and Py-GC/MS. Preliminary results show that all the paint layers analyzed are affected by salts (alkali sulphates) that over time have caused flacking, lack of cohesion, erosion, and lacunae. The light greenish/greenish bluish paint layers in all three panels are the most affected. No organic binders were identified, only the presence of vinyl polymer in glossy paint surfaces.
H-alpha and Ca ii Infrared Triplet Variations During a Transit of the 23 Myr Planet V1298 Tau c
Authors: Feinstein Adina D. , Montet Benjamin T. , Johnson Marshall C. , Bean Jacob L. , David Trevor J. , Gully-Santiago Michael A. , Livingston John H. , Luger Rodrigo
Published: October 2021

Young transiting exoplanets (<100 Myr) provide crucial insight into atmospheric evolution via photoevaporation. However, transmission spectroscopy measurements to determine atmospheric composition and mass loss are challenging due to the activity and prominent stellar disk inhomogeneities present on young stars. We observed a full transit of V1298 Tau c, a 23 Myr, 5.59 R
⊕ planet orbiting a young K0-K1.5 solar analog with GRACES on Gemini North. We were able to measure the Doppler tomographic signal of V1298 Tau c using the Ca ii infrared triplet (IRT) and find a projected obliquity of λ = 5° ± 15°. The tomographic signal is only seen in the chromospherically driven core of the Ca ii IRT, which may be the result of star-planet interactions. Additionally, we find that excess absorption of the Hα line decreases smoothly during the transit. While this could be a tentative detection of hot gas escaping the planet, we find this variation is consistent with similar timescale observations of other young stars that lack transiting planets over similar timescales. We show this variation can also be explained by the presence of starspots with surrounding facular regions. More observations both in and out of the transits of V1298 Tau c are required to determine the nature of the Ca ii IRT and Hα line variations.
MHD-PIC Simulations of Cosmic-Ray Scattering and Transport in Inhomogeneously Ionized Plasma
Authors: Bambic Christopher J. , Bai Xue-Ning , Ostriker Eve C.
Published: October 2021

Cosmic rays (CRs) have critical impacts in the multiphase interstellar medium (ISM), driving dynamical motions in low-density plasma and modifying the ionization state, temperature, and chemical composition of higher-density atomic and molecular gas. We present a study of CR propagation in inhomogeneously ionized plasma, addressing CR transport issues that arise in the cloudy ISM. Using one-dimensional magnetohydrodynamic (MHD) particle-in-cell simulations that include ion–neutral drag to damp Alfvén waves in a portion of the simulation domain, we self-consistently evolve the kinetic physics of CRs and background gas MHD. By introducing a damping region in our periodic domain, our simulations break translational symmetry and allow the emergence of spatial gradients in the CR distribution function. A spatial gradient opposite to the CR flux forms across the fully ionized region as a result of pitch angle scattering. We connect our results with CR hydrodynamics formulations by computing the wave–particle scattering rates as predicted by quasilinear, fluid, and Fokker–Planck theory. For momenta where the mean free path is short relative to the box size, we find excellent agreement among all scattering rates. However, we also find evidence of a reduced scattering rate for less energetic particles that are subject to the μ = 0 barrier in our simulations. Our work provides a first-principles verification of CR hydrodynamics when particles stream down their pressure gradient and opens a pathway toward comprehensive calibrations of transport coefficients from self-generated Alfvén wave scattering with CRs.
Infrared Excesses Around Bright White Dwarfs from Gaia and unWISE. II
Authors: Lai 赖 Samuel 民希 , Dennihy Erik , Xu 许 Siyi 偲艺 , Nitta Atsuko , Kleinman Scot , Leggett S. K. , Bonsor Amy , Hodgkin Simon , Rebassa-Mansergas Alberto , Rogers Laura K.
Published: October 2021

Infrared excesses around white dwarf stars indicate the presence of various astrophysical objects of interest, including companions and debris disks. In this second paper of a series, we present follow-up observations of infrared excess candidates from Gaia and unWISE discussed in the first paper, Paper I. We report space-based infrared photometry at 3.6 and 4.5 micron for 174 white dwarfs from the Spitzer Space Telescope and ground-based near-infrared J, H, and K photometry of 235 white dwarfs from Gemini Observatory with significant overlap between Spitzer and Gemini observations. These data are used to confirm or rule out the observed unWISE infrared excess. From the unWISE-selected candidate sample, the most promising infrared excess sample comes from both color and flux excess, which has a Spitzer confirmation rate of 95%. We also discuss a method to distinguish infrared excess caused by stellar or sub-stellar companions from potential dust disks. In total, we confirm the infrared excess around 62 white dwarfs, 10 of which are likely to be stellar companions. The remaining 52 bright white dwarfs with infrared excess beyond two microns has the potential to double the known sample of white dwarfs with dusty exoplanetary debris disks. Follow-up high-resolution spectroscopic studies of a fraction of confirmed excess white dwarfs in this sample have discovered emission from gaseous dust disks. Additional investigations will be able to expand the parameter space from which dust disks around white dwarfs are found.
X-Ray Plateaus in Gamma-Ray Burst Afterglows and Their Application in Cosmology
Authors: Xu Fan , Tang Chen-Han , Geng Jin-Jun , Wang Fa-Yin , Wang Yu-Yang , Kuerban Abudushataer , Huang Yong-Feng
Published: October 2021

For gamma-ray bursts (GRBs) with a plateau phase in the X-ray afterglow, a so-called L–T–E correlation that tightly connects the isotropic energy of the prompt GRB (E

γ,iso) with the end time of the X-ray plateau (T

a
) and the corresponding X-ray luminosity at the end time (L
X) has been found. Here we show that there is a clear redshift evolution in the correlation. Furthermore, because the power-law indices of L
X and E

γ,iso in the correlation function are almost identical, the L–T–E correlation is insensitive to cosmological parameters and cannot be used as a satisfactory standard candle. On the other hand, based on a sample including 121 long GRBs, we establish a new three-parameter correlation that connects L
X, T

a
, and the spectral peak energy E
p, i.e., the L–T–E
p correlation. This correlation strongly supports the so-called Combo-relation established by Izzo et al. After correcting for the redshift evolution, we show that the de-evolved L–T–E
p correlation can be used as a standard candle. By using this correlation alone, we are able to constrain the cosmological parameters as

Ω

m

=

0.389

−
0.141

+
0.202

(1σ) for the flat ΛCDM model, or

Ω

m

=

0.369

−
0.191

+
0.217

and

w
=
−

0.966

−
0.678

+
0.513

(1σ) for the flat wCDM model. Combining with other cosmological probes, more accurate constraints on the cosmology models are presented.
The Nature of Black Hole Shadows
Authors: Bronzwaer Thomas , Falcke Heino
Published: October 2021

A distinct visual signature occurs in black holes that are surrounded by optically thin and geometrically thick emission regions. This signature is a sharp-edged dip in brightness that is coincident with the black hole’s shadow, which is the projection of the black hole’s unstable-photon region on the observer’s sky. We highlight two key mechanisms that are responsible for producing the sharp-edged dip: (i) the reduction of intensity observed in rays that intersect the unstable-photon region, and thus the perfectly absorbing event horizon, versus rays that do not (blocking); and (ii) the increase of intensity observed in rays that travel along extended, horizon-circling paths near the boundary of the unstable-photon region (path-lengthening). We demonstrate that the black hole shadow is a distinct phenomenon from the photon ring, and that models exist in which the former may be observed but not the latter. Additionally, we show that the black hole shadow and its associated visual signature differ from the more model-dependent brightness depressions associated with thin-disk models because the blocking and path-lengthening effects are quite general for geometrically thick and optically thin emission regions. Consequentially, the black hole shadow is a robust and fairly model-independent observable for accreting black holes that are in the deep sub-Eddington regime, such as low-luminosity active galactic nuclei.
The Stability Boundary of the Distant Scattered Disk
Authors: Batygin Konstantin , Mardling Rosemary A. , Nesvorný David
Published: October 2021

The distant scattered disk is a vast population of trans-Neptunian minor bodies that orbit the Sun on highly elongated, long-period orbits. The orbital stability of scattered-disk objects (SDOs) is primarily controlled by a single parameter—their perihelion distance. While the existence of a perihelion boundary that separates chaotic and regular motion of long-period orbits is well established through numerical experiments, its theoretical basis as well as its semimajor axis dependence remain poorly understood. In this work, we outline an analytical model for the dynamics of distant trans-Neptunian objects and show that the orbital architecture of the scattered disk is shaped by an infinite chain of exterior 2:j resonances with Neptune. The widths of these resonances increase as the perihelion distance approaches Neptune’s semimajor axis, and their overlap drives chaotic motion. Within the context of this theoretical picture, we derive an analytic criterion for instability of long-period orbits, and demonstrate that rapid dynamical chaos ensues when the perihelion drops below a critical value, given by

q

crit

=

a

N

ln
(
(

24

2

/

5
)
(

m

N

/

M

⊙

)

a

/

a

N

5

/

2

)

1

/

2

. This expression constitutes an analytic boundary between the “detached” and actively “scattering” subpopulations of distant trans-Neptunian minor bodies. Additionally, we find that within the stochastic layer, the Lyapunov time of SDOs approaches the orbital period, and show that the semimajor axis diffusion coefficient is approximated by



a

∼
(
8

/

(
5
π
)
)
(

m

N

/

M

⊙

)



M

⊙

a

N

exp
​

−

q

/

a

N

2

/

2

. We confirm our results with direct N-body simulations and highlight the connections between scattered-disk dynamics and the Chirikov Standard Map. Implications of our results for the long-term evolution of minor bodies in the distant solar system are discussed.
The Role of Epigenetic Mechanism in the Pathogenesis of Inflammatory Bowel Disease
Authors: Siregar Gontar Alamsyah , Darmadi Darmadi , Ruslie Riska Habriel
Published: October 2021

Inflammatory bowel disease (IBD) is a chronic inflammation of the intestine due to interaction between inappropriate immune response and environmental factors. It consists of ulcerative colitis and Crohn’s disease. The incidence of IBD is increasing globally and disrupts patient’s quality of life and causes heavy economic burden. Several risk factors are involved in IBD including genetic, environment, lifestyle, and socioeconomic status. Antigen enters host’s gastrointestinal tract and triggers an immune reaction. In subject with IBD, the immune reaction is hyperactive. Some conditions such as intestinal barrier disintegration, gut microorganism imbalance, molecular mimicry, and abnormal autophagy trigger chronic inflammation and end with IBD. Genetic predisposition plays a central role in IBD. NOD2, IL23R, and ATG16L1 have the most significant association with IBD. With the presence of epigenetic mechanisms, patients with genetic predispositions have higher probability for suffering from IBD. The most common epigenetic mechanisms in the pathogenesis of IBD are DNA methylation and non-coding RNAs. The epigenetic mechanisms lead to changes in T-cell activity, cytokine production, intestinal epithelial integrity, autophagy activity, and innate immunity response. All of those cause chronic inflammation as the main characteristic of IBD. Genetic aspect can be a promising approach in managing IBD. The field of genetic may be applied in diagnosing, treating, and predicting disease outcomes. However, this topic still needs further investigations.
Effect of Different Surface Treatments of Glass Fiber Posts on their Surface Roughness and Flexure Properties
Authors: Hesham Mai , Hashem Ahmed , Hamza Faisal
Published: October 2021

AIM: This study aimed to assess the effect of different surface treatments on the surface roughness and flexure properties of glass fiber posts “GFPs.”
MATERIALS AND METHODS: A total of 40 GFPs were divided into four groups (n = 10): GC – no surface treatment (control), GSB – sandblasted, GHF – hydrofluoric acid etched, and GL – Er: YAG laser irradiated. Surface roughness was detected using surface profilometer and the 3-points bending flexural test measured flexural strength and elastic modulus.
RESULTS: GSB showed the highest mean roughness followed by GHF, then GL, while GC had lowest roughness mean value. The 3 points bending test results were calculated and recorded, GSB exhibited the highest flexure stress (MPa) compared to GHF and GL. Modulus of elasticity (GPa) showed significant differences between the tested groups, GSB showed the highest modulus of elasticity compared to GHF and GL, while GC showed insignificant differences with all tested groups.
CONCLUSION: Different surface treatments postulated in this study showed alternations of GFPs surfaces without jeopardizing the mechanical properties of GFPs.
Controverse robustesse / résilience : ce que revèlent les supply chains soumises à la crise Covid-19
Authors: Fabbe-Costes Nathalie , Ziad Yasmina
Published: October 2021

La crise pandémique de la Covid-19 a rappelé le caractère stratégique de la logistique et du supply chain management (SCM) pour tous les secteurs d’activité. Elle a aussi souligné l’importance d’avoir des supply chains (SCs) robustes et résilientes. L’article commence par montrer pourquoi la Covid-19 justifie, mieux que toute autre crise avant elle, la nécessité d’articuler robustesse et résilience. Il explique ensuite, à la lumière de la littérature, pourquoi il n’est pas si simple de penser et de développer conjointement robustesse et résilience. Les illustrations tirées de la crise Covid-19 apportent des éléments de réponse qui conduisent à proposer un cadre de synthèse pour passer de la controverse à une approche dialogique. La conclusion discute de la portée théorique et managériale des résultats, et ouvre des pistes de recherche et de réflexion qui dépassent le strict cadre de la logistique et du SCM.
Intégrer la mobilité résidentielle dans une politique de maintien à domicile
Authors: Hillcoat-Nallétamby Sarah , Ogg Jim , Sardani Alexandra
Published: October 2021

Cet article aborde la question de l’inclusion de la mobilité résidentielle dans une politique du « vieillir chez soi » et des mesures pratiques qui peuvent être mises en place pour faciliter un changement de domicile. La présentation d’une étude qualitative galloise permet d’explorer la manière dont un nouveau service, «  Moving by Choice  », a permis aux personnes âgées de déménager volontairement de leur domicile vers un habitat intermédiaire. Dix-huit personnes âgées ont été interrogées sur leur expérience du service, qui proposait des informations et des conseils personnalisés, ainsi qu’un soutien financier et pratique. Initialement conçu comme un simple service d’information, Moving by Choice est devenu un service d’accompagnement avant, pendant et après le déménagement. La présence physique d’un «  caseworker  » pendant le processus du déménagement, un soutien psychologique et l’implication des proches sont des facteurs importants qui aident les individus à faire des choix informés concernant un déménagement vers un habitat intermédiaire. Les résultats suggèrent qu’un tel service peut être développé pour faciliter la prise de décision des personnes âgées pendant leur transition résidentielle.
Déménager dans une résidence pour aînés au Québec : une stratégie pour faire face à la vulnérabilité
Authors: Boubaker Rana , Negron-Poblete Paula , Morales Ernesto
Published: October 2021

Les individus âgés passent plus de temps dans leur logement et leur quartier, de sorte que les caractéristiques de l’environnement résidentiel influencent particulièrement leur expérience du vieillissement. Comme cette expérience peut être caractérisée par des situations de vulnérabilités individuelle, économique ou sociale, elle peut aussi être marquée par une vulnérabilité face à l’environnement. Cet essai présente, à travers une étude de la littérature, la manière dont l’environnement physique contribue à la construction de la vulnérabilité chez l’aîné et son influence sur sa mobilité résidentielle. Nous avons choisi de nous référer aux textes récents qui ont été publiés, en majorité entre 2000 et 2019, pour examiner les différentes formes de vulnérabilités chez les aînés et présenter le concept de « vulnérabilité environnementale ». Face à elle, les personnes âgées peuvent développer diverses réponses qui constituent les stratégies de « défense » ou des moyens de « faire face » à cette situation. La mobilité vers une résidence pour aînés est une de ces réponses. Cet article présente d’abord le concept de vulnérabilité chez les aînés et ses différentes dimensions, notamment « la vulnérabilité environnementale » ; il expose ensuite le rôle de l’environnement physique et social dans la mobilité vers une résidence collective pour aînés. Enfin sont présentées les différentes propriétés environnementales de la résidence pour aînés, au niveau architectural et urbain, qui contribuent à la création du nouveau chez-soi et favorisent la qualité de vie chez la personne âgée qui déménage vers ce type de milieu résidentiel.
A Review on design of low noise amplifiers for global navigational satellite system
Authors: Priyanka Ch ,   Department of Electronics and Communication Engineering, Koneru Lakshmaiah Education Foundation, Vaddeswaram, Andhra Pradesh, India, Ratnam D Venkata , Santosh G Sai Krishna
Published: October 2021

Low noise amplifier (LNA) is a ubiquitous Radio Frequency (RF) component employed in the global navigation satellite system (GNSS) front end receiver to amplify the degraded RF signals captured by the antenna to the desired level. GNSS LNA boosts the desired signal power by adding minimal noise and distortion to mitigate the impact of noise added by subsequential components of the RF receiver chain thereby improving the overall signal-to-noise ratio (SNR) and the overall performance of the system. This paper explores the various GNSS LNA topologies that improve the system's overall performance with minimum power consumption, low noise figure (NF), high gain, good input-output matching, stability, and linearity. The outcome of this research work would help to design a successful LNA for enhancing the performance of the GNSS receiver.
Rapid exponential stabilization of Lotka-McKendrick's equation via event-triggered impulsive control
Authors: Dlala Mohsen ,   Department of Mathematics, College of Sciences, Qassim University, Buraydah, Saudi Arabia, Alrashidi Sharifah Obaid
Published: October 2021

This paper investigates the problem of rapid exponential stabilization for linear Lotka-McKendrick's equation. Based on a new event-triggered impulsive control (ETIC) method, an impulsive control is designed to solve the rapid exponential stabilization of the dynamic population Lotka-McKendrick's equation. The effectiveness of our control is verified through a numerical example.
Optimal gradient estimates for multi-phase integrals
Authors: De Filippis Cristiana ,   Dipartimento di Matematica "Giuseppe Peano", Università di Torino, Via Carlo Alberto 10, 10123 Torino, Italy
Published: October 2021

We prove sharp reverse Hölder inequalities for minima of multi-phase variational integrals and apply them to Calderón-Zygmund estimates for nonhomogeneous problems.