bluuebunny/crossref_metadata_2025 huggingface dataset:
Miscibility and Optimization of the Liquid Rubber Content in the Resins of Light-Cured Dental Composites
Authors: Pałka Krzysztof , Sowa Monika
Published: December 2022

Fracture toughness is one of the main factors influencing the durability of light-cured composites used for dental restorations and fillings. One of the methods of increasing the fracture toughness is the modification of the matrix with liquid acrylonitrile-free liquid rubber. This study aimed to assess the miscibility of acrylonitrile-free liquid rubber with a blend of resins and their stability over time, and to determine the optimal amount of liquid rubber (LR) in the blend due to mechanical properties. Two blends of dimethacrylate resins were used: resin “F” composed of BisGMA (60 wt.%), TEGDMA (20 wt.%), BisEMA (10 wt.%) and UDMA (10 wt.%), and “C” resin containing BisGMA (40 wt.%), TEGDMA (40 wt.%), BisEMA (10 wt.%) and UDMA (10 wt.%). The modifier Hypro® 2000X168LC VTB liquid rubber was used in at 1%, 2%, 3%, 4%, 5%, 10%, 15% and 20% by weight in the resin blend. The miscibility was assessed by microscopy. The fracture toughness, flexural strength and Young’s modulus were determined in the bending test. The results showed that the solubility of the liquid rubber depends on the ratio of BisGMA/TEGDMA in the resins. In resins with 40 wt.% TEGDMA, the LR solubility was as high as 5%, while resins with 20 wt.% TEGDMA, the liquid rubber did not dissolve. The LR-resin mixtures showed good time stability, and no changes in the size or morphology of the rubber domains were found after 24 h of mixing. The maximum fracture toughness (2.46 MPa m1/2) was obtained for 5 wt.% LR in resin F and for 15 wt.% LR in resin C (2.53 MPa m1/2). The modification with liquid rubber resulted in an exponential reduction in both flexural strength and Young’s modulus. The analysis of the results of the mechanical tests allowed us to determine the optimal amount of LR for both resins. For resin F it was 5.4 wt.%, and for resin C it was 8.3 wt.%. It can be stated that the optimal amount of liquid rubber increases with its solubility in the resin.
Research on Modification of Fe3O4 Magnetic Nanoparticles with Two Silane Coupling Agents
Authors: Cui Hongchao , Zhang Jiajia , Lu Jingjing , Li Zhenkun , Li Decai
Published: December 2022

As a novel functional nanomaterial, Fe3O4 magnetic nanoparticles (MNPs) modified by different surfactants have attracted and are attracting worldwide interest. In this research, we introduced two different silane coupling agents to modify Fe3O4 MNPs instead of a single surfactant to achieve complete coating and functionalization. The modification mechanism was also explained. Techniques such as TEM, XRD, FT-IR, TG-DSC, and VSM were applied to characterize the obtained modified Fe3O4 sample. From these techniques, the following information is obtained: The characteristic bands of TEOS and KH-792 were present in the FT-IR spectra and in the XPS plots of modified Fe3O4 MNPs, demonstrating that the silane coupling agents were present in the sample obtained after the modification. The TG analysis of the modified sample showed complete decomposition at 228 °C. The mass ratio of the sample obtained before and after the modification was close to 29:65. The XRD patterns show that the modified Fe3O4 MNPs possessed an identical reverse spinel crystal structure as an unmodified Fe3O4 sample. The modification decreased the saturation magnetization of Fe3O4 MNPs from 70.04 emu/g to 57.41 emu/g and the coating did not change the superparamagnetism of Fe3O4 MNPs.
Alkyl Glycerol Ethers as Adaptogens
Authors: Sultanov Ruslan , Ermolenko Ekaterina , Poleshchuk Tatiana , Kasyanov Sergey
Published: December 2022

Τhis mini-review summarizes the hematopoietic and immunostimulating properties of alkyl glycerol ethers (AGs) reported earlier in the literature available to us. The role of AGs in the nervous system and aging of the body are also briefly described. We made an attempt to consider the data in terms of adaptation. The hematopoietic, immunostimulating and antioxidant properties of AGs in a variety of experimental situations, including stress, as well as the protective action of AGs against some adaptation diseases, allow us to consider them as substances that prevent some negative effects of stress and promote adaptation. The new approach to AGs as adaptogens seems promising and opens good opportunities for their new application.
Design and Implementation of a Ku-Band High-Precision Blackbody Calibration Target
Authors: Liu Jie , Sun Zhenlin , Sun Guangmin , Li Yu , Cao Tong , Tang Wenjie
Published: December 2022

Microwave radiometers can be used in human tissue temperature measurement scenarios due to the advantages of non-destructive and non-contact temperature measurement. However, their accuracy often cannot meet the needs of practical applications. In this paper, a Ku-Band high-precision blackbody calibration target is designed to provide calibration for microwave radiometers and meet the requirements of a high temperature-measurement accuracy and high temperature-measurement resolution. From a practical application point of view, the blackbody calibration target needs to have the characteristics of high emissivity and high temperature uniformity. However, previous studies on blackbody calibration targets often focused on the scattering characteristics or temperature uniformity of the calibration target separately, and thus lack a comprehensive consideration of the two characteristics. In this paper, the electromagnetic scattering model and the temperature-distribution model of the calibration target are established through the multi-physical simulation combined with the Finite Element Method. Then, according to the simulation results of the two characteristic models, the structural parameters and composition of the coated cone array are continuously optimized. In addition, to achieve high-precision temperature control of the blackbody calibration target, this paper studies three PID controller parameter self-tuning algorithms, namely, BP-PID, PSO-PID and Fuzzy-PID for the optimal parameter tuning problem of traditional PID algorithms and determines the optimal temperature-control algorithm by comparing the performance of heating and cooling processes. Then, the blackbody calibration target is processed and manufactured. The arch test system is used to validate the reflectance of the calibration target, the emissivity is calculated indirectly, and the temperature-distribution uniformity of the temperature-control panel of the calibration target is tested by a multi-point distribution method. Finally, the uncertainty of the brightness temperature of the blackbody calibration target is analyzed.
Development of Microalgae Biodiesel: Current Status and Perspectives
Authors: Casanova Livia Marques , Mendes Leonardo Brantes Bacellar , Corrêa Thamiris de Souza , da Silva Ronaldo Bernardo , Joao Rafael Richard , Macrae Andrew , Vermelho Alane Beatriz
Published: December 2022

Microalgae are regarded as a promising source of biodiesel. In contrast with conventional crops currently used to produce commercial biodiesel, microalgae can be cultivated on non-arable land, besides having a higher growth rate and productivity. However, microalgal biodiesel is not yet regarded as economically competitive, compared to fossil fuels and crop-based biodiesel; therefore, it is not commercially produced. This review provides an overall perspective on technologies with the potential to increase efficiency and reduce the general costs of biodiesel production from microalgae. Opportunities and challenges for large-scale production are discussed. We present the current scenario of Brazilian research in the field and show a successful case in the research and development of microalgal biodiesel in open ponds by Petrobras. This publicly held Brazilian corporation has been investing in research in this sector for over a decade.
A Comparison of Primary Human Hepatocytes and Hepatoma Cell Lines to Model the Effects of Fatty Acids, Fructose and Glucose on Liver Cell Lipid Accumulation
Authors: Huggett Zoë J. , Smith Alison , De Vivo Nicola , Gomez Dhanny , Jethwa Preeti , Brameld John M. , Bennett Andrew , Salter Andrew M.
Published: December 2022

Non-alcoholic fatty liver disease (NAFLD) begins with lipid accumulation within hepatocytes, but the relative contributions of different macronutrients is still unclear. We investigated the impact of fatty acids, glucose and fructose on lipid accumulation in primary human hepatocytes (PHH) and three different cell lines: HepG2 (human hepatoblastoma–derived cell line), Huh7 (human hepatocellular carcinoma cell line) and McA-RH7777 (McA, rat hepatocellular carcinoma cell line). Cells were treated for 48 h with fatty acids (0 or 200 μM), glucose (5 mM or 11 mM) and fructose (0 mM, 2 mM or 8 mM). Lipid accumulation was measured via Nile Red staining. All cell types accumulated lipid in response to fatty acids (p < 0.001). PHH and McA, but not HepG2 or Huh7 cells, accumulated more lipid with 11 mM glucose plus fatty acids (p = 0.004, fatty acid × glucose interaction, for both), but only PHH increased lipid accumulation in response to fructose (p < 0.001). Considerable variation was observed between PHH cells from different individuals. Lipid accumulation in PHH was increased by insulin (p = 0.003) with inter-individual variability. Similarly, insulin increased lipid accumulation in both HepG2 and McA cells, with a bigger response in McA in the presence of fatty acids (p < 0.001 for fatty acid × insulin). McA were more insulin sensitive than either HepG2 or Huh7 cells in terms of AKT phosphorylation (p < 0.001 insulin × cell type interaction). Hence, glucose and fructose can contribute to the accumulation of lipid in PHH with considerable inter-individual variation, but hepatoma cell lines are not good models of PHH.
Comment on Aaseth et al. Circulating Lipoproteins in Subjects with Morbid Obesity Undergoing Bariatric Surgery with Gastric Bypass or Sleeve Gastrectomy. Nutrients 2022, 14, 2381
Authors: Paredes Sílvia , Garcez Jonatas Barbosa , Ribeiro Laura
Published: December 2022

We read with great interest the paper by Jan O. Aaseth et al. entitled “Circulating Lipoproteins in Subjects with Morbid Obesity Undergoing Bariatric Surgery with Gastric Bypass or Sleeve Gastrectomy” where changes in lipid profile after bariatric surgery were reported [...]
Spectral Optical Properties of Gray Matter in Human Male Brain Tissue Measured at 400–1100 nm
Authors: Ali Jamal H.
Published: December 2022

Gray matter, in the outermost layer of the cerebral cortex, plays a significant role in processing important information, such as when reasoning and planning, in addition to influencing intelligence, emotion, memory, and language. In this paper, measurements of the optical properties, such as the attenuation coefficients, scattering coefficients, scattering efficiency, and penetration depth of gray matter in the cerebral cortex were measured in the fresh brain tissue of a healthy human male at a spectral range of 400–1100 nm. Determining the optical properties of gray matter is important for developing NIR noninvasive diagnostic imaging techniques and therapy. The absorption spectra of the gray matter tissues obtained here showed clear peaks at 550 and 580 nm due to HBO2 and 970 nm due to water. The attenuation coefficient, transport length, and penetration depth for the gray matter were measured at 800 nm. The possible NIR optical imaging depth was roughly 3.8 mm, determined by the theoretical limit resulting from ballistic and snake photons. Using Beer’s law and the Mie model, the structural properties, such as the density of neurons, in the gray matter of human brain tissue, were investigated for the first time. The density of neurons in the examined gray matter tissue sample was estimated as roughly 40,000 neurons/mg.
Manipulated Oral and Rectal Drugs in a Paediatric Swedish University Hospital, a Registry-Based Study Comparing Two Study-Years, Ten Years Apart
Authors: Andersson Åsa C. , Eksborg Staffan , Förberg Ulrika , Nydert Per , Lindemalm Synnöve
Published: December 2022

This is a registry-based study with the aim of describing and comparing the frequency of manipulations of solid oral and rectal medicines in 2009 and 2019 at inpatient units and an emergency department in a paediatric hospital within a Swedish university hospital. All patients aged 1 month–18 years with oral or rectal administrations were included. In total, 140,791 oral and rectal administrations were included in 2009, and 167,945 oral and rectal administrations were included in 2019. The frequency of patients receiving at least one manipulated oral medicine decreased between the study years, both in inpatient units and in the emergency department (from 19% to 17%, p = 0.0029 and from 11% to 5%, p < 0.0001, respectively). The frequency of patients receiving a manipulated rectal medicine also decreased between the study years, both in inpatient units and in the emergency department (from 22% to 10%, p < 0.0001 and from 35% to 7% 2019, p < 0.0001, respectively). The results show a decrease in the manipulation of both oral and rectal medicines to paediatric patients in 2019 compared to 2009. Even though this implies a safer practice, there is still a pronounced lack of child-friendly dosage forms and suitable strengths enabling the safe administration of medicines to sick children.
Transethosomal Gel for the Topical Delivery of Celecoxib: Formulation and Estimation of Skin Cancer Progression
Authors: Abdellatif Ahmed A. H. , Aldosari Basmah Nasser , Al-Subaiyel Amal , Alhaddad Aisha , Samman Waad A. , Eleraky Nermin E. , Elnaggar Marwa G. , Barakat Hassan , Tawfeek Hesham M.
Published: December 2022

The topical delivery of therapeutics is a promising strategy for managing skin conditions. Cyclooxygenase-2 (COX-2) inhibitors showed a possible target for chemoprevention and cancer management. Celecoxib (CXB) is a selective COX-2 inhibitor that impedes cell growth and generates apoptosis in different cell tumors. Herein, an investigation proceeded to explore the usefulness of nano lipid vesicles (transethosomes) (TES) of CXB to permit penetration of considerable quantities of the drug for curing skin cancer. The prepared nanovesicles were distinguished for drug encapsulation efficiency, vesicle size, PDI, surface charge, and morphology. In addition, FT-IR and DSC analyses were also conducted to examine the influence of vesicle components. The optimized formulation was dispersed in various hydrogel bases. Furthermore, in vitro CXB release and ex vivo permeability studies were evaluated. A cytotoxicity study proceeded using A431 and BJ1 cell lines. The expression alteration of the cyclin-dependent kinase inhibitor 2A (CDKN2A) gene and DNA damage and fragmentation using qRT-PCR and comet assays were also investigated. Optimized CXB-TES formulation was spherically shaped and displayed a vesicle size of 75.9 ± 11.4 nm, a surface charge of −44.7 ± 1.52 mV, and an entrapment efficiency of 88.8 ± 7.2%. The formulated TES-based hydrogel displayed a sustained in vitro CXB release pattern for 24 h with an enhanced flux and permeation across rat skin compared with the control (free drug-loaded hydrogel). Interestingly, CXB-TES hydrogel has a lower cytotoxic effect on normal skin cells compared with TES suspension and CXB powder. Moreover, the level of expression of the CDKN2A gene was significantly (p ≤ 0.01, ANOVA/Tukey) decreased in skin tumor cell lines compared with normal skin cell lines, indicating that TES are the suitable carrier for topical delivery of CXB to the cancer cells suppressing their progression. In addition, apoptosis demonstrated by comet and DNA fragmentation assays was evident in skin cancer cells exposed to CXB-loaded TES hydrogel formulation. In conclusion, our results illustrate that CXB-TES-loaded hydrogel could be considered a promising carrier and effective chemotherapeutic agent for the management of skin carcinoma.
Optimization of an Injectable Hydrogel Depot System for the Controlled Release of Retinal-Targeted Hybrid Nanoparticles
Authors: Ottonelli Ilaria , Bighinati Andrea , Adani Elisa , Loll François , Caraffi Riccardo , Vandelli Maria Angela , Boury Frank , Tosi Giovanni , Duskey Jason Thomas , Marigo Valeria , Ruozi Barbara
Published: December 2022

A drawback in the development of treatments that can reach the retina is the presence of barriers in the eye that restrain compounds from reaching the target. Intravitreal injections hold promise for retinal delivery, but the natural defenses in the vitreous can rapidly degrade or eliminate therapeutic molecules. Injectable hydrogel implants, which act as a reservoir, can allow for long-term drug delivery with a single injection into the eye, but still suffer due to the fast clearance of the released drugs when traversing the vitreous and random diffusion that leads to lower pharmaceutic efficacy. A combination with HA-covered nanoparticles, which can be released from the gel and more readily pass through the vitreous to increase the delivery of therapeutic agents to the retina, represents an advanced and elegant way to overcome some of the limitations in eye drug delivery. In this article, we developed hybrid PLGA-Dotap NPs that, due to their hyaluronic acid coating, can improve in vivo distribution throughout the vitreous and delivery to retinal cells. Moreover, a hydrogel implant was developed to act as a depot for the hybrid NPs to better control and slow their release. These results are a first step to improve the treatment of retinal diseases by protecting and transporting the therapeutic treatment across the vitreous and to improve treatment options by creating a depot system for long-term treatments.
Role of Hepatocyte Transporters in Drug-Induced Liver Injury (DILI)—In Vitro Testing
Authors: Tátrai Péter , Erdő Franciska , Krajcsi Péter
Published: December 2022

Bile acids and bile salts (BA/BS) are substrates of both influx and efflux transporters on hepatocytes. Canalicular efflux transporters, such as BSEP and MRP2, are crucial for the removal of BA/BS to the bile. Basolateral influx transporters, such as NTCP, OATP1B1/1B3, and OSTα/β, cooperate with canalicular transporters in the transcellular vectorial flux of BA/BS from the sinusoids to the bile. The blockage of canalicular transporters not only impairs the bile flow but also causes the intracellular accumulation of BA/BS in hepatocytes that contributes to, or even triggers, liver injury. In the case of BA/BS overload, the efflux of these toxic substances back to the blood via MRP3, MRP4, and OST α/β is considered a relief function. FXR, a key regulator of defense against BA/BS toxicity suppresses de novo bile acid synthesis and bile acid uptake, and promotes bile acid removal via increased efflux. In drug development, the early testing of the inhibition of these transporters, BSEP in particular, is important to flag compounds that could potentially inflict drug-induced liver injury (DILI). In vitro test systems for efflux transporters employ membrane vesicles, whereas those for influx transporters employ whole cells. Additional in vitro pharmaceutical testing panels usually include cellular toxicity tests using hepatocytes, as well as assessments of the mitochondrial toxicity and accumulation of reactive oxygen species (ROS). Primary hepatocytes are the cells of choice for toxicity testing, with HepaRG cells emerging as an alternative. Inhibition of the FXR function is also included in some testing panels. The molecular weight and hydrophobicity of the drug, as well as the steady-state total plasma levels, may positively correlate with the DILI potential. Depending on the phase of drug development, the physicochemical properties, dosing, and cut-off values of BSEP IC50 ≤ 25–50 µM or total Css,plasma/BSEP IC50 ≥ 0.1 may be an indication for further testing to minimize the risk of DILI liability.
Photodynamic Therapy, Photobiomodulation and Acetonide Triamcinolone 0.1% in the Treatment of Oral Lichen Planus: A Randomized Clinical Trial
Authors: Salinas-Gilabert Carmen , Gómez García Francisco , Galera Molero Fe , Pons-Fuster Eduardo , Vander Beken Seppe , Lopez Jornet Pia
Published: December 2022

Objective: To evaluate the efficacy of photodynamic therapy (PDT) and photobiomodulation (PBM) in the treatment of oral lichen planus (OLP) in comparison with the use of topical corticosteroids. Material and methods: Sixty patients with OLP were randomized to three groups: group 1 photodynamic therapy applied once a week for four sessions, with orabase cream; group 2 low-power laser application with orabase cream; and group 3 inactive laser with triamcinolone acetonide 0.1%. Patient pain was evaluated, and the Thongprasom severity score, the Oral Health Impact Profile-14 (OHIP-14), and the Hamilton anxiety and depression scale at one and three months of follow-up. (ClinicalTrials.gov Identifier: NCT05127083). Results: Pain decreased significantly over time in all groups, though the symptoms relapsed over follow-up at one and three months in group 3. The OHIP-14 score improved significantly in groups 1 and 2 (p < 0.05), and this improvement was maintained after three months. Lesion resolution evaluated by the Thongprasom score at one month showed significant differences between groups 1 and 3 (p = 0.032) and between groups 2 and 3 (p = 0.024). Conclusions: Photodynamic therapy and photobiomodulation once a week for four weeks are safe and non-invasive treatment options, with the important advantage of lacking adverse effects. Further studies are needed to confirm it.
A Review on Pharmacy Practice in South Africa—A Higher Education Perspective
Authors: Mosiane Thokozile , Nkonde Kalaba , Mahlatsi Gauda , Mncwangi Nontobeko P.
Published: December 2022

In April 1994, South Africa underwent the most significant change in its recent history with the disbandment of the policy of apartheid and the attendant race-based politics, which affected most aspects of the country and, of relevance to this review, the education, health delivery, and career choices that race groups could pursue. In the past 28 years, the South African government has tried to implement policies in order to advance political and socioeconomic shifts toward a more equitable society. The healthcare sector was an early target for transformation that was aimed at increasing access to services and the expansion of primary healthcare and hospital facilities to previously underserved areas. This paper seeks to discuss these changes in broad terms, but with specific reference to general health care and pharmacy practice in particular. It will look at the changes in the legislative framework and pharmacy education and factors impacting the pharmacy practices in South Africa over the past 28 years. A discussion of the critical issues that have affected the profession in the last three decades will also be delineated, and future prospects for the profession as a whole, in terms of pharmacy practice and perspectives, will be discussed. We review the current aspects of the pharmacy profession in South Africa today and how the education of those future professionals is a major contribution to the pharmaceutical climate.
Experimental Investigation of an Optical Resonator Gyroscope with a Mach–Zehnder Modulator and Its Sensitive Elements
Authors: Filatov Yurii V. , Gilev Daniil G. , Goncharova Polina S. , Krishtop Victor V. , Kukaev Alexander S. , Ovchinnikov Konstantin A. , Sevryugin Alexander A. , Shalymov Egor V. , Venediktov Vladimir Yu.
Published: December 2022

Today, the task of developing microoptical gyroscopes is topical. Usually, tunable lasers with a built-in frequency stabilization system are used in such gyroscopes. They are comparatively bulky, which hinders the real miniaturization of optical gyroscopes. We propose a new approach implemented by using a Mach–Zehnder modulator with a passive ring resonator connected to one of its arms. This makes it possible to obtain a mutual configuration and makes the use of a tunable laser optional. Two ring resonators made of the polarization-maintaining fiber, suitable for use as sensitive elements of a gyroscope, were realized and investigated. Their Q-factor is equal to 14.5 × 106 and 28.9 × 106. The maximum sensitivity of the proposed method when using the described resonators is 3.2 and 1.8 °/h, respectively. The first experimental setup of a resonator gyroscope implementing this approach has been manufactured and analyzed. When measuring the rotation speed by the quasi-harmonic signal span and its phase, the measurement accuracy was approximately 11 and 0.4 °/s, respectively.
A Passively Wavelength-Stabilized Mid-Infrared Optical Parametric Oscillator
Authors: Hu Liemao , He Yunze , Lv Xinjie , Ning Jian , Zhao Gang , Zhu Shining
Published: December 2022

High-power and widely tunable continuous-wave optical parametric oscillators (cw OPOs), as mature radiation sources in the mid-infrared range, are limited by their frequency fluctuation. We built a cw OPO working at the near- and mid-infrared ranges and discuss the extent to which its frequency stability is affected by the mechanical temperature and the air pressure of the cavity. In addition, we artificially provoked mode hops by changing the above two factors to analyze the thermal-induced refractive index variation of the crystal. An inequality between the spacing of the hops and the free spectrum range (FSR) was observed. The wavelength stability of the cw OPO was guaranteed passively, and the longest mode-hopping-free time exceeded 13 h through sealing the cavity and thermal control. Further analysis of factors affecting frequency drift is critically essential for the reliability of cw OPO, particularly in environments outside the laboratory, and may provide a new method for high-precision tuning wavelengths.
Viable Properties of Natural Rubber/Halloysite Nanotubes Composites Affected by Various Silanes
Authors: Hayeemasae Nabil , Masa Abdulhakim , Othman Nadras , Surya Indra
Published: December 2022

Natural rubber (NR) is incompatible with hydrophilic additives like halloysite nanotubes (HNT) due to their different polarity. The silane coupling agent is the ideal component to include in such a compound to solve this problem. Many types of silane are available for polymer composites depending on their functionalities. This work aimed to tune it to the composite based on NR and HNT. Four different silanes, namely Bis[3- (Triethoxysilyl)Propyl]Tetrasulfide (TESPT), 3-Aminopropyl triethoxysilane (APTES), N-[3-(Trimethoxysilyl)Propyl] Ethylenediamine (AEAPTMS), and Vinyltrimethoxysilane (VTMS) were used. Here, the mechanical properties were used to assess the properties, paying close attention to how their reinforcement influenced their crystallization behavior after stretching. It was revealed that adding silane coupling agents greatly improved the composites’ modulus, tensile strength, and tear strength. From the overall findings, AEAPTMS was viable for NR/HNT composites. This was in direct agreement with the interactions between NR and HNT that silanes had encouraged. The findings from stress-strain curves describing the crystallization of the composites are in good agreement with the findings from synchrotron wide-angle X-ray scattering (WAXS). The corresponding silanes have substantially aided the strain-induced crystallization (SIC) of composites.
Effect of the Welan Gum Concentration on the Rheological and Structural Behaviour of Biocomposite Hydrogels with Sepiolite as Filler
Authors: Carmona José A. , Ramírez Pablo , Calero Nuria , Muñoz José
Published: December 2022

A very positive and effective approach to tuning the mechanical properties of polymers has been the development of composites. This paper deals with novel biocomposite hydrogels composed by two biocompatible materials: welan gum as biopolymer matrix and sepiolite as filler. Welan gum content was studied as a tuning parameter to control the rheological properties of the developed biocomposites. The rheological and microstructural behaviour of the composites was investigated by mean of steady-state flow curves, creep-recovery tests, small amplitude oscillatory shear tests, and electron microscopy. An increase in welan gum content provoked the progressive disappearance of the shear-thinningzero-shear-thinning behaviour with a yield point which was clearly defined, characteristic of sepiolite gels, leading to a conventional shear-thinning behaviour, typical of polymeric systems. Also, a higher content of biopolymer in the mixtures led to a more elastic and compact structure characterized by higher values of both G’ and G”. The fundamental novelty was based on taking the flowability provided by the biopolymer as the main objective and reinforcing the viscosity yielded by welan gum with sepiolite, which contributed to increasing the biocomposite consistency. Thus, rheological properties can be adjusted, taking into account the balance of the components to adapt them to the requirements of each application.
The Odae chinŏn (Five Great Mantras) and Dhāraṇī Collections in Premodern Korea
Authors: McBride Richard D.
Published: December 2022

The Five Great Mantras (Odae chinŏn) is one of the most widely circulated collections of Buddhist dhāraṇīs in premodern Korea, having been published or existing in several variant editions during the Chosŏn period (1392–1910). The title refers to the following dhāraṇīs: (1) “The Forty-Two Mantras of the Bodhisattva Avalokiteśvara,” (2) Nīlakaṇṭha-dhāraṇī, (3) Mahāpratisarā-dhāraṇī, (4) Buddhoṣṇīṣa-dhāraṇī, and (5) Uṣṇīṣavijaya-dhāraṇī. Another spell, “The Basic Dhāraṇī of the Bodhisattva Avalokiteśvara,” was also added, so there are a total of six dhāraṇīs contained in the book. Although most scholarship has hitherto understood the Five Great Mantras to date from the late fifteenth century, when editions with transcriptions of the dhāraṇīs in the Korean script appeared in trilingual format along with Siddhaṃ and Sinitic transliterations, due to the patronage of Queen Insu (1437–1508) and the linguistic ability of the monk Hakcho (fl. 1464–1520), some evidence has come to light suggesting that the Five Great Mantras was initially published as early as the mid-fourteenth century in the late Koryŏ period (918–1392). This essay provides a detailed analysis of the components that appear in the Five Great Mantras by analyzing six variant editions of the text dating from the Chosŏn period, including Brief Transcriptions of Efficacious Resonance (Yŏnghŏm yakch’o) in Sinitic and Korean vernacular translation. The Five Great Mantras demonstrates the significance of non-canonical materials in the Korean Buddhist tradition and suggests a fruitful avenue for study of similar woodblock prints and manuscripts in the Sinitic Buddhist tradition.
A Cloud Detection Method Based on Spectral and Gradient Features for SDGSAT-1 Multispectral Images
Authors: Ge Kaiqiang , Liu Jiayin , Wang Feng , Chen Bo , Hu Yuxin
Published: December 2022

Due to the limited penetration of visible bands, optical remote sensing images are inevitably contaminated by clouds. Therefore, cloud detection or cloud mask products for optical image processing is a very important step. Compared with conventional optical remote sensing satellites (such as Landsat series and Sentinel-2), sustainable development science Satellite-1 (SDGSAT-1) multi-spectral imager (MII) lacks a short-wave infrared (SWIR) band that can be used to effectively distinguish cloud and snow. To solve the above problems, a cloud detection method based on spectral and gradient features (SGF) for SDGSAT-1 multispectral images is proposed in this paper. According to the differences in spectral features between cloud and other ground objects, the method combines four features, namely, brightness, normalized difference water index (NDWI), normalized difference vegetation index (NDVI), and haze-optimized transformation (HOT) to distinguish cloud and most ground objects. Meanwhile, in order to adapt to different environments, the dynamic threshold using Otsu’s method is adopted. In addition, it is worth mentioning that gradient features are used to distinguish cloud and snow in this paper. With the test of SDGSAT-1 multispectral images and comparison experiments, the results show that SGF has excellent performance. The overall accuracy of images with snow surface can reach 90.80%, and the overall accuracy of images with other surfaces is above 94%.
Dropsonde-Based Heat Fluxes and Mixed Layer Height over the Sea Surface near the Korean Peninsula
Authors: Kim Min-Seong , Kwon Byung Hyuk , Goo Tae-Young , Jung Sueng-Pil
Published: December 2022

Dropsonde-based sensible heat flux, latent heat flux, and buoyancy flux were estimated over the sea around the Korean Peninsula in 2021. During a preceding severe weather (SW) mission, a total of 243 dropsondes were released from a National Institute of Meteorological Sciences (NIMS) Atmospheric Research Aircraft (NARA). The heat fluxes were indirectly validated by comparison with model-based heat fluxes. The sensible heat flux calculated by the bulk transfer method depended entirely on the temperature difference between the sea level and atmosphere, whereas the latent heat flux was mainly affected by wind speed. Boundary layer heights above 800 m are closely related to buoyancy flux, which is greater in regions with higher sea surface temperatures. Furthermore, the utility of the dropsonde was confirmed in the marine atmospheric boundary layer (MABL) growth, which is difficult to observe in situ and, a relationship was proposed for estimating MABL based on mean meteorological data over the sea level.
Detecting Moving Vehicles from Satellite-Based Videos by Tracklet Feature Classification
Authors: Chen Renxi , Ferreira Vagner G. , Li Xinhui
Published: December 2022

Satellite-based video enables potential vehicle monitoring and tracking for urban traffic management. However, due to the tiny size of moving vehicles and cluttered background, it is difficult to distinguish actual targets from random noise and pseudo-moving objects, resulting in low detection accuracy. In contrast to the currently overused deep-learning-based methods, this study takes full advantage of the geometric properties of vehicle tracklets (segments of moving object trajectory) and proposes a tracklet-feature-based method that can achieve high precision and high recall. The approach is a two-step strategy: (1) smoothing filtering is used to suppress noise, and then a non-parametric-based background subtracting model is applied for obtaining preliminary recognition results with high recall but low precision; and (2) generated tracklets are used to discriminate between true and false vehicles by tracklet feature classification. Experiments and evaluations were performed on SkySat and ChangGuang acquired videos, showing that our method can improve precision and retain high recall, outperforming some classical and deep-learning methods from previously published literature.
FARMSAR: Fixing AgRicultural Mislabels Using Sentinel-1 Time Series and AutoencodeRs
Authors: Di Martino Thomas , Guinvarc’h Régis , Thirion-Lefevre Laetitia , Colin Elise
Published: December 2022

This paper aims to quantify the errors in the provided agricultural crop types, estimate the possible error rate in the available dataset, and propose a correction strategy. This quantification could establish a confidence criterion useful for decisions taken on this data or to have a better apprehension of the possible consequences of using this data in learning downstream functions such as classification. We consider two agricultural label errors: crop type mislabels and mis-split crops. To process and correct these errors, we design a two-step methodology. Using class-specific convolutional autoencoders applied to synthetic aperture radar (SAR) time series of free-to-use and temporally dense Sentinel-1 data, we detect out-of-distribution temporal profiles of crop time series, which we categorize as one out of the three following possibilities: crop edge confusion, incorrectly split crop areas, and potentially mislabeled crop. We then relabel crops flagged as mislabeled using an Otsu threshold-derived confidence criteria. We numerically validate our methodology using a controlled disruption of labels over crops of confidence. We then compare our methods to supervised algorithms and show improved quality of relabels, with up to 98% correct relabels for our method, against up to 91% for Random Forest-based approaches. We show a drastic decrease in the performance of supervised algorithms under critical conditions (smaller and larger amounts of introduced label errors), with Random Forest falling to 56% of correct relabels against 95% for our approach. We also explicit the trade-off made in the design of our method between the number of relabels, and their quality. In addition, we apply this methodology to a set of agricultural labels containing probable mislabels. We also validate the quality of the corrections using optical imagery, which helps highlight incorrectly cut crops and potential mislabels. We then assess the applicability of the proposed method in various contexts and scales and present how it is suitable for verifying and correcting farmers’ crop declarations.
Monitoring Coastal Erosion Using Remote Images: Comparison between Physically and Remotely Acquired Data on a Limestone Coast
Authors: Causon Deguara Joanna , Gauci Ritienne , Inkpen Rob
Published: December 2022

Boulder-sized clasts on rocky coasts are considered as erosional signatures of extreme wave events and boulder attributes are often used in numerical models to estimate wave characteristics. The use of unmanned aerial vehicle (UAV) technology and related software has facilitated the monitoring of coastal areas, by generating models from which 2D and 3D measurements can be derived. However, the reliability and preciseness of such measurements is still to be determined. This study seeks to analyse the accuracy of boulder measurements by comparing the dimension data obtained through in-situ measurements with ex situ data generated from digital models, based on UAV images. The study area is a bouldered sloping coast located on the southeast coast of Malta (Central Mediterranean) that has developed into multiple limestone dipped strata with a fractured and heavily jointed morphology. The dimensions of c. 200 boulders in different morphological settings, such as clusters or ridges, have been statistically compared. The results show a very strong correlation between the two datasets, both in 2D and 3D; however some notable differences were observed at the individual boulder level. For the majority of boulders analysed, the A and B axes dimensions varied by ±10% to 20%. The C axis proved to be harder to measure accurately and showed a wider range of difference. Boulder volume results in the majority of cases varied from 0% to ±40%. Some tested methods of volume calculation may be more accurate and realistic than others depending on the boulder position in relation to other clasts and shore morphology. An automated digital analysis of the terrain surface to identify the boulder extents may offer possibilities for a more accurate estimation of boulder attributes.
Time Series Analysis Methods and Detectability Factors for Ground-Based Imaging of the LCROSS Impact Plume
Authors: Strycker Paul D. , Chanover Nancy J. , Temme Ruth L. , Schotte Jonathan M. , Mueller Payton L. , Karls Emily L.
Published: December 2022

On 9 October 2009, multiple telescopes were used in a coordinated international observing campaign to acquire ground-based time series imaging to monitor the evolution of the impact plume from NASA’s Lunar CRater Observation and Sensing Satellite (LCROSS) mission. Although standard image processing techniques applied to these data were unsuccessful at detecting the presence of any impact plume, one detection was reported after processing images with Principal Component Analysis (PCA) filtering. In this work, we develop improvements to PCA filtering that increase the signal-to-noise ratio (SNR) of plume lightcurves. We use this updated methodology to remove atmospheric seeing effects not accounted for in the previous work, such as geometric distortions. We assess the robustness of PCA filtering as we search for plume detections in observations from five additional cameras in comparison with each pixel’s lightcurve during the final 40 s prior to impact to match the approximate duration of post-impact excess brightness. We explore the resulting combination of three detections and three non-detections to determine criteria for detectability in future observations of low SNR transient events. Our results indicate three observational setup constraints for optimizing the success of PCA filtering: (1) full-frame scattered light should not exceed the dynamic range between the illuminated and unilluminated surfaces, (2) the camera’s analog-to-digital conversion (ADC) should use at least 16-bit resolution, and (3) the ADC should not use gamma correction. We find that poor spatial or temporal resolution do not significantly degrade detectability, which suggests that any future LCROSS-like events may be detectable in PCA-filtered amateur observations.
Deep Learning in Diverse Intelligent Sensor Based Systems
Authors: Zhu Yanming , Wang Min , Yin Xuefei , Zhang Jue , Meijering Erik , Hu Jiankun
Published: December 2022

Deep learning has become a predominant method for solving data analysis problems in virtually all fields of science and engineering. The increasing complexity and the large volume of data collected by diverse sensor systems have spurred the development of deep learning methods and have fundamentally transformed the way the data are acquired, processed, analyzed, and interpreted. With the rapid development of deep learning technology and its ever-increasing range of successful applications across diverse sensor systems, there is an urgent need to provide a comprehensive investigation of deep learning in this domain from a holistic view. This survey paper aims to contribute to this by systematically investigating deep learning models/methods and their applications across diverse sensor systems. It also provides a comprehensive summary of deep learning implementation tips and links to tutorials, open-source codes, and pretrained models, which can serve as an excellent self-contained reference for deep learning practitioners and those seeking to innovate deep learning in this space. In addition, this paper provides insights into research topics in diverse sensor systems where deep learning has not yet been well-developed, and highlights challenges and future opportunities. This survey serves as a catalyst to accelerate the application and transformation of deep learning in diverse sensor systems.
A Self-Referenced Refractive Index Sensor Based on Gold Nanoislands
Authors: Barrios Carlos Angulo , Mirea Teona , Represa Miguel Huerga
Published: December 2022

We report on a self-referenced refractive index optical sensor based on Au nanoislands. The device consists of a random distribution of Au nanoislands formed by dewetting on a planar SiO2/metal Fabry–Pérot cavity. Experimental and theoretical studies of the reflectance of this configuration reveal that its spectral response results from a combination of two resonances: a localized surface plasmon resonance (LSPR) associated to the Au nanoislands and the lowest-order anti-symmetric resonance of the Fabry–Pérot cavity. When the device is immersed in different fluids, the LSPR contribution provides high sensitivity to refractive index variations of the fluid, whereas those refractive index changes have little impact on the Fabry–Pérot resonance wavelength, allowing its use as a reference signal. The self-referenced sensor exhibits a spectral sensitivity of 212 nm/RIU (RIU: refractive index unit), which is larger than those of similar structures, and an intensity sensitivity of 4.9 RIU−1. The proposed chip-based architecture and the low cost and simplicity of the Au nanoisland synthesis procedure make the demonstrated sensor a promising self-referenced plasmonic sensor for compact biosensing optical platforms based on reflection mode operation.
Future Technologies for Train Communication: The Role of LEO HTS Satellites in the Adaptable Communication System
Authors: Vizzarri Alessandro , Mazzenga Franco , Giuliano Romeo
Published: December 2022

The railway sector has been characterized by important innovations regarding digital technologies for train-to-ground communications. The actual GSM-R system is considered an obsolescent technology expected to be dismissed by 2030. The future communication systems in the rail sectors, such as Adaptable Communication Systems (ACS) and Future Railway Mobile Communication Systems (FRMCS), can manage different bearers as 4G/5G terrestrial technologies and satellites. In this environment, the new High Throughput Satellite (HTS) Low-Earth Orbit (LEO) constellations promise very interesting performances from data rate and coverage points of view. The paper analyzes the LEO constellations of Starlink and OneWeb using public data. The Rome–Florence railway line is considered for simulations. The results evidence the LEO satellite can provide interesting performance in terms of visibility, service connectivity, and traffic capacities (up to 1 Gbps). This feature enables the LEO to fully manage a high amount of data, especially in the railway scenarios of the next years when video data applications will be more present.
Hallway Gait Monitoring System Using an In-Package Integrated Dielectric Lens Paired with a mm-Wave Radar
Authors: Abedi Hajar , Boger Jennifer , Morita Plinio Pelegrini , Wong Alexander , Shaker George
Published: December 2022

This paper presents a novel hallway gait extraction system that enables an individual’s spatiotemporal gait parameter extraction at each gait cycle using a single FMCW (Frequency Modulated Continuous Wave) radar. The purpose of the proposed system is to detect changes in gait that may be the signs of changes in mobility, cognition, and frailty, particularly for older adults in retirement homes. We believe that one of the straightforward applications for gait monitoring using radars is in corridors and hallways, which are commonly available in most retirement and long-term care homes. To achieve in-corridor coverage, we designed an in-package hyperbola-based lens antenna integrated with a radar module package empowered by our fast and easy-to-implement gait extraction method. We validated system functionality by capturing spatiotemporal gait values (e.g., speed, step points, step time, step length, and step count) of people walking in a hallway. The results achieved in this work pave the way to explore the use of stand-alone radar-based sensors in long hallways in retirement apartment buildings or individual’s homes for use in day-to-day long-term monitoring of gait parameters of older adults.