bluuebunny/crossref_metadata_2025 huggingface dataset:
Functionalized Lipid Nanocarriers for Simultaneous Delivery of Docetaxel and Tariquidar to Chemoresistant Cancer Cells
Authors: Kim Chang Hyun , Lee Sangkil , Choi Ji Yeh , Lyu Min Jeong , Jung Hyun Min , Goo Yoon Tae , Kang Myung Joo , Choi Young Wook
Published: February 2023

The simultaneous drug delivery efficiency of a co-loaded single-carrier system of docetaxel (DTX)- and tariquidar (TRQ)-loaded nanostructured lipid carrier (NLC) functionalized with PEG and RIPL peptide (PRN) (D^T-PRN) was compared with that of a physically mixed dual-carrier system of DTX-loaded PRN (D-PRN) and TRQ-loaded PRN (T-PRN) to overcome DTX mono-administration-induced multidrug resistance. NLC samples were prepared using the solvent emulsification evaporation technique and showed homogeneous spherical morphology, with nano-sized dispersion (<220 nm) and zeta potential values of −15 to −7 mV. DTX and/or TRQ was successfully encapsulated in NLC samples (>95% encapsulation efficiency and 73–78 µg/mg drug loading). In vitro cytotoxicity was concentration-dependent; D^T-PRN exhibited the highest MDR reversal efficiency, with the lowest combination index value, and increased the cytotoxicity and apoptosis in MCF7/ADR cells by inducing cell-cycle arrest in the G2/M phase. A competitive cellular uptake assay using fluorescent probes showed that, compared to the dual nanocarrier system, the single nanocarrier system exhibited better intracellular delivery efficiency of multiple probes to target cells. In the MCF7/ADR-xenografted mouse models, simultaneous DTX and TRQ delivery using D^T-PRN significantly suppressed tumor growth as compared to other treatments. A single co-loaded system for PRN-based co-delivery of DTX/TRQ (1:1, w/w) constitutes a promising therapeutic strategy for drug-resistant breast cancer cells.
5,8-Dimethyl-9H-carbazole Derivatives Blocking hTopo I Activity and Actin Dynamics
Authors: Ceramella Jessica , Iacopetta Domenico , Caruso Anna , Mariconda Annaluisa , Petrou Anthi , Geronikaki Athina , Rosano Camillo , Saturnino Carmela , Catalano Alessia , Longo Pasquale , Sinicropi Maria Stefania
Published: February 2023

Over the years, carbazoles have been largely studied for their numerous biological properties, including antibacterial, antimalarial, antioxidant, antidiabetic, neuroprotective, anticancer, and many more. Some of them have gained great interest for their anticancer activity in breast cancer due to their capability in inhibiting essential DNA-dependent enzymes, namely topoisomerases I and II. With this in mind, we studied the anticancer activity of a series of carbazole derivatives against two breast cancer cell lines, namely the triple negative MDA-MB-231 and MCF-7 cells. Compounds 3 and 4 were found to be the most active towards the MDA-MB-231 cell line without interfering with the normal counterpart. Using docking simulations, we assessed the ability of these carbazole derivatives to bind human topoisomerases I and II and actin. In vitro specific assays confirmed that the lead compounds selectively inhibited the human topoisomerase I and interfered with the normal organization of the actin system, triggering apoptosis as a final effect. Thus, compounds 3 and 4 are strong candidates for further drug development in multi-targeted therapy for the treatment of triple negative breast cancer, for which safe therapeutic regimens are not yet available.
Recent Advances of Photoactive Near-Infrared Carbon Dots in Cancer Photodynamic Therapy
Authors: Song Jinxing , Gao Xiaobo , Yang Mei , Hao Weiju , Ji Ding-Kun
Published: February 2023

Photodynamic therapy (PDT) is a treatment that employs exogenously produced reactive oxygen species (ROS) to kill cancer cells. ROS are generated from the interaction of excited-state photosensitizers (PSs) or photosensitizing agents with molecular oxygen. Novel PSs with high ROS generation efficiency is essential and highly required for cancer photodynamic therapy. Carbon dots (CDs), the rising star of carbon-based nanomaterial family, have shown great potential in cancer PDT benefiting from their excellent photoactivity, luminescence properties, low price, and biocompatibility. In recent years, photoactive near-infrared CDs (PNCDs) have attracted increasing interest in this field due to their deep therapeutic tissue penetration, superior imaging performance, excellent photoactivity, and photostability. In this review, we review recent progress in the designs, fabrication, and applications of PNCDs in cancer PDT. We also provide insights of future directions in accelerating the clinical progress of PNCDs.
The Mechanism of Action of SAAP-148 Antimicrobial Peptide as Studied with NMR and Molecular Dynamics Simulations
Authors: Adélaïde Morgane , Salnikov Evgeniy , Ramos-Martín Francisco , Aisenbrey Christopher , Sarazin Catherine , Bechinger Burkhard , D’Amelio Nicola
Published: February 2023

Background: SAAP-148 is an antimicrobial peptide derived from LL-37. It exhibits excellent activity against drug-resistant bacteria and biofilms while resisting degradation in physiological conditions. Despite its optimal pharmacological properties, its mechanism of action at the molecular level has not been explored. Methods: The structural properties of SAAP-148 and its interaction with phospholipid membranes mimicking mammalian and bacterial cells were studied using liquid and solid-state NMR spectroscopy as well as molecular dynamics simulations. Results: SAAP-148 is partially structured in solution and stabilizes its helical conformation when interacting with DPC micelles. The orientation of the helix within the micelles was defined by paramagnetic relaxation enhancements and found similar to that obtained using solid-state NMR, where the tilt and pitch angles were determined based on 15N chemical shift in oriented models of bacterial membranes (POPE/POPG). Molecular dynamic simulations revealed that SAAP-148 approaches the bacterial membrane by forming salt bridges between lysine and arginine residues and lipid phosphate groups while interacting minimally with mammalian models containing POPC and cholesterol. Conclusions: SAAP-148 stabilizes its helical fold onto bacterial-like membranes, placing its helix axis almost perpendicular to the surface normal, thus probably acting by a carpet-like mechanism on the bacterial membrane rather than forming well-defined pores.
3D-Printing of Silk Nanofibrils Reinforced Alginate for Soft Tissue Engineering
Authors: Mohammadpour Zahra , Kharaziha Mahshid , Zarrabi Ali
Published: February 2023

The main challenge of extrusion 3D bioprinting is the development of bioinks with the desired rheological and mechanical performance and biocompatibility to create complex and patient-specific scaffolds in a repeatable and accurate manner. This study aims to introduce non-synthetic bioinks based on alginate (Alg) incorporated with various concentrations of silk nanofibrils (SNF, 1, 2, and 3 wt.%) and optimize their properties for soft tissue engineering. Alg-SNF inks demonstrated a high degree of shear-thinning with reversible stress softening behavior contributing to extrusion in pre-designed shapes. In addition, our results confirmed the good interaction between SNFs and alginate matrix resulted in significantly improved mechanical and biological characteristics and controlled degradation rate. Noticeably, the addition of 2 wt.% SNF improved the compressive strength (2.2 times), tensile strength (5 times), and elastic modulus (3 times) of alginate. In addition, reinforcing 3D-printed alginate with 2 wt.% SNF resulted in increased cell viability (1.5 times) and proliferation (5.6 times) after 5 days of culturing. In summary, our study highlights the favorable rheological and mechanical performances, degradation rate, swelling, and biocompatibility of Alg-2SNF ink containing 2 wt.% SNF for extrusion-based bioprinting.
Amorphous Solid Dispersions Layered onto Pellets—An Alternative to Spray Drying?
Authors: Neuwirth Marius , Kappes Sebastian K. , Hartig Michael U. , Wagner Karl G.
Published: February 2023

Spray drying is one of the most frequently used solvent-based processes for manufacturing amorphous solid dispersions (ASDs). However, the resulting fine powders usually require further downstream processing when intended for solid oral dosage forms. In this study, we compare properties and performance of spray-dried ASDs with ASDs coated onto neutral starter pellets in mini-scale. We successfully prepared binary ASDs with a drug load of 20% Ketoconazole (KCZ) or Loratadine (LRD) as weakly basic model drugs and hydroxypropyl-methyl-cellulose acetate succinate or methacrylic acid ethacrylate copolymer as pH-dependent soluble polymers. All KCZ/ and LRD/polymer mixtures formed single-phased ASDs, as indicated by differential scanning calorimetry, X-ray powder diffraction and infrared spectroscopy. All ASDs showed physical stability for 6 months at 25 °C/65% rH and 40 °C/0% rH. Normalized to their initial surface area available to the dissolution medium, all ASDs showed a linear relationship of surface area and solubility enhancement, both in terms of supersaturation of solubility and initial dissolution rate, regardless of the manufacturing process. With similar performance and stability, processing of ASD pellets showed the advantages of a superior yield (>98%), ready to use for subsequent processing into multiple unit pellet systems. Therefore, ASD-layered pellets are an attractive alternative in ASD-formulation, especially in early formulation development at limited availability of drug substance.
Perspectives of Therapeutic Drug Monitoring of Biological Agents in Non-Infectious Uveitis Treatment: A Review
Authors: Busto-Iglesias Manuel , Rodríguez-Martínez Lorena , Rodríguez-Fernández Carmen Antía , González-López Jaime , González-Barcia Miguel , de Domingo Begoña , Rodríguez-Rodríguez Luis , Fernández-Ferreiro Anxo , Mondelo-García Cristina
Published: February 2023

Biological drugs, especially those targeting anti-tumour necrosis factor α (TNFα) molecule, have revolutionized the treatment of patients with non-infectious uveitis (NIU), a sight-threatening condition characterized by ocular inflammation that can lead to severe vision threatening and blindness. Adalimumab (ADA) and infliximab (IFX), the most widely used anti-TNFα drugs, have led to greater clinical benefits, but a significant fraction of patients with NIU do not respond to these drugs. The therapeutic outcome is closely related to systemic drug levels, which are influenced by several factors such as immunogenicity, concomitant treatment with immunomodulators, and genetic factors. Therapeutic drug monitoring (TDM) of drug and anti-drug antibody (ADAbs) levels is emerging as a resource to optimise biologic therapy by personalising treatment to bring and maintain drug concentration within the therapeutic range, especially in those patients where a clinical response is less than expected. Furthermore, some studies have described different genetic polymorphisms that may act as predictors of response to treatment with anti-TNFα agents in immune-mediated diseases and could be useful in personalising biologic treatment selection. This review is a compilation of the published evidence in NIU and in other immune-mediated diseases that support the usefulness of TDM and pharmacogenetics as a tool to guide clinicians’ treatment decisions leading to better clinical outcomes. In addition, findings from preclinical and clinical studies, assessing the safety and efficacy of intravitreal administration of anti-TNFα agents in NIU are discussed.
Preclinical PET Imaging and Toxicity Study of a 68Ga-Functionalized Polymeric Cardiac Blood Pool Agent
Authors: Saatchi Katayoun , Bénard François , Hundal Navjit , Grimes Joshua , Shcherbinin Sergey , Pourghiasian Maral , Brooks Donald E. , Celler Anna , Häfeli Urs O.
Published: February 2023

Cardiac blood pool imaging is currently performed almost exclusively with 99mTc-based compounds and SPECT/CT imaging. Using a generator-based PET radioisotope has a few advantages, including not needing nuclear reactors to produce it, obtaining better resolution in humans, and potentially reducing the radiation dose to the patient. When the shortlived radioisotope 68Ga is used, it can be applied repeatedly on the same day—for example, for the detection of bleeding. Our objective was to prepare and evaluate a long-circulating polymer functionalized with gallium for its biodistribution, toxicity, and dosimetric properties. A 500 kDa hyperbranched polyglycerol was conjugated to the chelator NOTA and radiolabeled rapidly at room temperature with 68Ga. It was then injected intravenously into a rat, and gated imaging allowed us to easily observe wall motion and cardiac contractility, confirming the suitability of this radiopharmaceutical for cardiac blood pool imaging. Internal radiation dose calculations showed that the radiation doses that patients would receive from the PET agent would be 2.5× lower than those from the 99mTc agent. A complete 14-day toxicology study in rats concluded that there were no gross pathology findings, changes in body or organ weights, or histopathological events. This radioactive-metal-functionalized polymer might be a suitable non-toxic agent to advance for clinical application.
Intrathecal Pseudodelivery of Drugs in the Therapy of Neurodegenerative Diseases: Rationale, Basis and Potential Applications
Authors: Manuel Menéndez-González , Tamba Bogdan-Ionel , Leclere Maxime , Mabrouk Mostafa , Schreiner Thomas-Gabriel , Ciobanu Romeo , Cristina Tomás-Zapico
Published: February 2023

Intrathecal pseudodelivery of drugs is a novel route to administer medications to treat neurodegenerative diseases based on the CSF-sink therapeutic strategy by means of implantable devices. While the development of this therapy is still in the preclinical stage, it offers promising advantages over traditional routes of drug delivery. In this paper, we describe the rationale of this system and provide a technical report on the mechanism of action, that relies on the use of nanoporous membranes enabling selective molecular permeability. On one side, the membranes do not permit the crossing of certain drugs; whereas, on the other side, they permit the crossing of target molecules present in the CSF. Target molecules, by binding drugs inside the system, are retained or cleaved and subsequently eliminated from the central nervous system. Finally, we provide a list of potential indications, the respective molecular targets, and the proposed therapeutic agents.
Future Pharmacotherapy for Sensorineural Hearing Loss by Protection and Regeneration of Auditory Hair Cells
Authors: Matsunaga Mami , Nakagawa Takayuki
Published: February 2023

Sensorineural hearing loss has been a global burden of diseases for decades. However, according to recent progress in experimental studies on hair cell regeneration and protection, clinical trials of pharmacotherapy for sensorineural hearing loss have rapidly progressed. In this review, we focus on recent clinical trials for hair cell protection and regeneration and outline mechanisms based on associated experimental studies. Outcomes of recent clinical trials provided valuable data regarding the safety and tolerability of intra-cochlear and intra-tympanic applications as drug delivery methods. Recent findings in molecular mechanisms of hair cell regeneration suggested the realization of regenerative medicine for sensorineural hearing loss in the near future.
Reduction-Hypersensitive Podophyllotoxin Prodrug Self-Assembled Nanoparticles for Cancer Treatment
Authors: Wang Xinhui , Wang Yuequan , Yu Jiaxin , Qiu Qian , Liao Rui , Zhang Shenwu , Luo Cong
Published: February 2023

Podophyllotoxin (PPT) has shown strong antitumor effects on various types of cancers. However, the non-specific toxicity and poor solubility severely limits its clinical transformation. In order to overcome the adverse properties of PPT and explore its clinical potential, three novel PTT−fluorene methanol prodrugs linked by different lengths of disulfide bonds were designed and synthesized. Interestingly, the lengths of the disulfide bond affected the drug release, cytotoxicity, pharmacokinetic characteristics, in vivo biodistribution and antitumor efficacy of prodrug NPs. To be more specific, all three PPT prodrugs could self-assemble into uniform nanoparticles (NPs) with high drug loading (>40%) via the one-step nano precipitation method, which not only avoids the use of surfactants and cosurfactants, but also reduces the systemic toxicity of PPT and increases the tolerated dose. Among the three prodrug NPs, FAP NPs containing α-disulfide bond showed the most sensitive tumor-specific response and fastest drug release rate, thus demonstrating the strongest in vitro cytotoxicity. In addition, three prodrug NPs showed prolonged blood circulation and higher tumor accumulation. Finally, FAP NPs demonstrated the strongest in vivo antitumor activity. Our work will advance the pace of podophyllotoxin towards clinical cancer treatment.
Effects of Piper nigrum L. Fruit Essential Oil Toxicity against Stable Fly (Diptera: Muscidae)
Authors: Weluwanarak Thekhawet , Changbunjong Tanasak , Leesombun Arpron , Boonmasawai Sookruetai , Sungpradit Sivapong
Published: February 2023

The efficacy of Piper nigrum L. fruit essential oil (EO) against Stomoxys calcitrans (stable fly), a blood-feeding fly distributed worldwide, was investigated. This study aimed to evaluate the insecticidal activity of EO based on contact and fumigant toxicity tests. Chemical analysis of the EO using gas chromatography–mass spectrometry revealed that sabinene (24.41%), limonene (23.80%), β-caryophyllene (18.52%), and α-pinene (10.59%) were the major components. The results demonstrated that fly mortality increased with increasing EO concentration and time during the first 24 h of exposure. The median lethal dose was 78.37 µg/fly for contact toxicity, while the 90% lethal dose was 556.28 µg/fly. The median lethal concentration during fumigant toxicity testing was 13.72 mg/L air, and the 90% lethal concentration was 45.63 mg/L air. Our findings suggested that essential oil extracted from P. nigrum fruit could be a potential natural insecticidal agent for control of stable fly. To examine the insecticidal properties of P. nigrum fruit EO, further field trials and investigation into the efficacy of nano-formulations are required.
Non-Covalent Interactions in Polymers
Authors: Novikov Alexander S.
Published: February 2023

Non-covalent interactions are one of the key topics in modern chemical science. These inter- and intramolecular weak interactions (e.g., hydrogen, halogen, and chalcogen bonds, stacking interactions and metallophilic contacts) have a significant effect on the properties of polymers. In this Special Issue, “Non-covalent interactions in polymers”, we tried to collect fundamental and applied research manuscripts (original research articles and comprehensive review papers) focused on non-covalent interactions in polymer chemistry and related fields. The scope of the Special Issue is very broad: we welcome all the contributions that deal with the synthesis, structure, functionality and properties of polymer systems involving non-covalent interactions.
Sorption of CO2, CH4 and Their Mixtures in Amorphous Poly(2,6-dimethyl-1,4-phenylene)oxide (PPO)
Authors: Loianno Valerio , Baldanza Antonio , Scherillo Giuseppe , Musto Pellegrino , Mensitieri Giuseppe
Published: February 2023

Sorption of pure CO2 and CH4 and CO2/CH4 binary gas mixtures in amorphous glassy Poly(2,6-dimethyl-1,4-phenylene) oxide (PPO) at 35 °C up to 1000 Torr was investigated. Sorption experiments were carried out using an approach that combines barometry with FTIR spectroscopy in the transmission mode to quantify the sorption of pure and mixed gases in polymers. The pressure range was chosen to prevent any variation of the glassy polymer density. The solubility within the polymer of the CO2 present in the gaseous binary mixtures was practically coincident with the solubility of pure gaseous CO2, up to a total pressure of the gaseous mixtures equal to 1000 Torr and for CO2 mole fractions of ~0.5 mol mol−1 and ~0.3 mol mol−1. The Non-Equilibrium Thermodynamics for Glassy Polymers (NET-GP) modelling approach has been applied to the Non-Random Hydrogen Bonding (NRHB) lattice fluid model to fit the solubility data of pure gases. We have assumed here that no specific interactions were occurring between the matrix and the absorbed gas. The same thermodynamic approach has been then used to predict the solubility of CO2/CH4 mixed gases in PPO, resulting in a deviation lower than 9.5% from the experimental results for CO2 solubility.
A Fluorinated Polyimide Based Nano Silver Paste with High Thermal Resistance and Outstanding Thixotropic Performance
Authors: Wang Zhenhe , Wang Dong , Zhang Chunbo , Chen Wei , Meng Qingjie , Yuan Hang , Yang Shiyong
Published: February 2023

Because of high conductivity, acceptable cost and good screen-printing process performance, silver pastes have been extensively used for making flexible electronics. However, there are few reported articles focusing on high heat resistance solidified silver pastes and their rheological properties. In this paper, a fluorinated polyamic acids (FPAA) is synthesized by polymerization of the 4,4′-(hexafluoroisopropylidene) diphthalic anhydride and 3,4′-diaminodiphenylether as monomers in the diethylene glycol monobutyl. The nano silver pastes are prepared by mixing the obtained FPAA resin with nano silver powder. The agglomerated particles caused by nano silver powder are divided and the dispersion of nano silver pastes are improved by three-roll grinding process with low roll gaps. The obtained nano silver pastes possess excellent thermal resistance with 5% weight loss temperature higher than 500 °C. The volume resistivity of cured nano silver paste achieves 4.52 × 10−7 Ω·m, when the silver content is 83% and the curing temperature is 300 °C. Additionally, the nano silver pastes have high thixotropic performance, which contributes to fabricate the fine pattern with high resolution. Finally, the conductive pattern with high resolution is prepared by printing silver nano pastes onto PI (Kapton-H) film. The excellent comprehensive properties, including good electrical conductivity, outstanding heat resistance and high thixotropy, make it a potential application in flexible electronics manufacturing, especially in high-temperature fields.
Dispersion Homogeneity of Silicon Anode Slurries with Various Binders for Li-Ion Battery Anode Coating
Authors: Kim Bogyoung , Song Yeeun , Youn Byungwook , Lee Doojin
Published: February 2023

We aimed to determine the relationship between surface chemistry and the rheological properties of silicon anode slurries in lithium-ion batteries. To accomplish this, we investigated the use of various binders such as PAA, CMC/SBR, and chitosan as a means to control particle aggregation and improve the flowability and homogeneity of the slurry. Additionally, we utilized zeta potential analysis to examine the electrostatic stability of the silicon particles in the presence of different binders, and the results indicated that the conformations of the binders on the silicon particles can be influenced by both neutralization and the pH conditions. Furthermore, we found that the zeta potential values served as a useful metric for evaluating binder adsorption and particle dispersion in the solution. We also conducted three-interval thixotropic tests (3ITTs) to examine the structural deformation and recovery characteristics of the slurry, and the results demonstrated that these properties vary depending on the strain intervals, pH conditions, and chosen binder. Overall, this study emphasized the importance of taking into account surface chemistry, neutralization, and pH conditions when assessing the rheological properties of the slurry and coating quality for lithium-ion batteries.
Independent Heating Performances in the Sub-Zero Environment of MWCNT/PDMS Composite with Low Electron-Tunneling Energy
Authors: Min Yun Kyung , Eom Taesik , Kim Heonyoung , Kang Donghoon , Lee Sang-Eui
Published: February 2023

The structural stability of various structures (railroads, bridges, buildings, etc.) is lowered due to freezing because of the decreasing outside temperature in winter. To prevent damage from freezing, a technology for de-icing has been developed using an electric-heating composite. For this purpose, a highly electrically conductive composite film with multi-wall carbon nanotubes (MWCNTs) uniformly dispersed in a polydimethylsiloxane (PDMS) matrix through a three-roll process was fabricated by shearing the MWCNT/PDMS paste, through a two-roll process. The electrical conductivity and the activation energy of the composite were 326.5 S/m and 8.0 meV at 5.82 Vol% of MWCNTs, respectively. The dependence of the electric-heating performance (heating rate and temperature change) on the applied voltage and environmental temperature (from −20 °C to 20 °C) was evaluated. The heating rate and effective-heat-transfer characteristics were observed to decrease as the applied voltage increased, while they showed the opposite tendency when the environmental temperature was at sub-zero temperatures. Nevertheless, the overall heating performance (heating rate and temperature change) was maintained with little significant difference in the considered external-temperature range. The unique heating behaviors can result from the low activation energy and the negative-temperature (T) coefficient of resistance (R) (NTCR, dR/dT < 0) of the MWCNT/PDMS composite.
MMP-2 Silencing through siRNA Loaded Positively-Charged Nanoparticles (AcPEI-NPs) Counteracts Chondrocyte De-Differentiation
Authors: Conte Raffaele , Finicelli Mauro , Borrone Alessia , Margarucci Sabrina , Peluso Gianfranco , Calarco Anna , Bosetti Michela
Published: February 2023

The abnormal matrix remodeling process, as well as inflammation, angiogenesis, and tumor metastasis, are related to an increase in the synthesis and secretion of matrix metalloproteinases (MMPs), the zinc-dependent proteolytic endopeptidases. Recent studies have evidenced MMPs’ role in osteoarthritis (OA) development, during which chondrocytes undergo hypertrophic differentiation and exhibit enhanced catabolism. The trait of OA is extracellular matrix (ECM) progressive degradation regulated by many factors, in which MMPs play an important role, which indicates them as potential therapeutic targets. Herein, a small interfering RNA (siRNA) delivery system able to suppress MMPs’ activity was synthetized. Results demonstrated that positively charged nanoparticles (AcPEI-NPs) complexed with MMP-2 siRNA are efficiently internalized by cells with endosomal escape. Moreover, avoiding lysosome degradation, MMP2/AcPEI nanocomplex increases nucleic acid delivery efficiency. Gel zymography, RT-PCR, and ELISA analyses confirmed MMP2/AcPEI nanocomplex activity even when embedded within collagen matrix resembling the natural extracellular matrix. Further, the inhibition of in vitro collagen degradation exerts a protective effect on chondrocyte dedifferentiation. The suppression of MMP-2 activity, preventing matrix degradation, protects chondrocytes against degeneration and supporting ECM homeostasis in articular cartilage. These encouraging results promote further investigation to validate the utilization of MMP-2 siRNA as ‘‘molecular switch’’ able to counteract osteoarthritis.
Three-Dimensional Printing of Recycled Polypropylene and Activated Carbon Coatings for Harmful Gas Adsorption and Antibacterial Properties
Authors: Park Jung Bin , An Seok Hwan , Jung Jae Woong , Lee Jea Uk
Published: February 2023

In recent years, the utilization of three-dimensional (3D) printing has been expanding due to advances in technology and economic efficiency. One of the 3D printing technologies is fused deposition modeling, which can be used to create different kinds of products or prototypes from various polymer filaments. In this study, the activated carbon (AC) coating was introduced to the 3D outputs printed using recycled polymer materials to impart multi-functions such as adsorption of harmful gas and antimicrobial activities. A filament of uniform diameter (1.75 μm) and a filter template in the form of a 3D fabric shape were prepared through the extrusion and 3D printing processes, respectively, of the recycled polymer. In the next process, the 3D filter was developed by coating the nanoporous AC, produced from the pyrolysis fuel oil and waste PET, on the 3D filter template through direct coating. The 3D filters coated with the nanoporous activated carbon showed the enhanced adsorption capacity of 1038.74 mg of SO2 gas and the antibacterial properties of 49% removal of E. coli bacteria. As a model system, a functional gas mask that has harmful gas adsorption abilities and antibacterial properties has been produced by a 3D printing process.
Intelligent Eucommia ulmoides Rubber/Ionomer Blends with Thermally Activated Shape Memory and Self-Healing Properties
Authors: Wang Qi , Li Yutao , Xiao Jianbin , Xia Lin
Published: February 2023

Intelligent Eucommia ulmoides rubber (EUR) and ionomer Surlyn resin (SR) blends were prepared and studied in this manuscript. This is the first paper to combine EUR with SR to prepare blends with both the shape memory effect and self-healing capability. The mechanical, curing, thermal, shape memory and self-healing properties were studied by a universal testing machine, differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA), respectively. Experimental results showed that the increase in ionomer content not only improved mechanical and shape memory properties but also endowed the compounds with excellent self-healing ability under the appropriate environmental conditions. Notably, the self-healing efficiency of the composites reached 87.41%, which is much higher than the efficiency of other covalent cross-linking composites. Therefore, these novel shape memory and self-healing blends can expand the use of natural Eucommia ulmoides rubber, such as in special medical devices, sensors and actuators.
Natural Fibre Composites and Their Mechanical Behaviour
Authors: Banea Mariana Doina
Published: February 2023

At present, natural-fibre-reinforced-composites (NFRCs) are seen as realistic alternatives to synthetic- (e [...]
Lignin-Loaded Carbon Nanoparticles as a Promising Control Agent against Fusarium verticillioides in Maize: Physiological and Biochemical Analyses
Authors: El-Ganainy Sherif Mohamed , Mosa Mohamed A. , Ismail Ahmed Mahmoud , Khalil Ashraf E.
Published: February 2023

Lignin, a naturally occurring biopolymer, is produced primarily as a waste product by the pulp and paper industries and burned to produce electricity. Lignin-based nano- and microcarriers found in plants are promising biodegradable drug delivery platforms. Here, we highlight a few characteristics of a potential antifungal nanocomposite consisting of carbon nanoparticles (C-NPs) with a defined size and shape containing lignin nanoparticles (L-NPs). Spectroscopic and microscopic studies verified that the lignin-loaded carbon nanoparticles (L-CNPs) were successfully prepared. Under in vitro and in vivo conditions, the antifungal activity of L-CNPs at various doses was effectively tested against a wild strain of F. verticillioides that causes maize stalk rot disease. In comparison to the commercial fungicide, Ridomil Gold SL (2%), L-CNPs introduced beneficial effects in the earliest stages of maize development (seed germination and radicle length). Additionally, L-CNP treatments promoted positive effects on maize seedlings, with a significant increment in the level of carotenoid, anthocyanin, and chlorophyll pigments for particular treatments. Finally, the soluble protein content displayed a favorable trend in response to particular dosages. Most importantly, treatments with L-CNPs at 100 and 500 mg/L significantly reduced stalk rot disease by 86% and 81%, respectively, compared to treatments with the chemical fungicide, which reduced the disease by 79%. These consequences are substantial considering the essential cellular function carried out by these special natural-based compounds. Finally, the intravenous L-CNPs treatments in both male and female mice that affected the clinical applications and toxicological assessments are explained. The results of this study suggest that L-CNPs are of high interest as biodegradable delivery vehicles and can be used to stimulate favorable biological responses in maize when administered in the recommended dosages, contributing to the idea of agro-nanotechnology by demonstrating their unique qualities as a cost-effective alternative compared to conventional commercial fungicides and environmentally benign nanopesticides for long-term plant protection.
Evaluation of Composites Reinforced by Processed and Unprocessed Coconut Husk Powder
Authors: Coverdale Rangel Velasco David , Perissé Duarte Lopes Felipe , Souza Djalma , Colorado Lopera Henry Alonso , Neves Monteiro Sergio , Fontes Vieira Carlos Maurício
Published: February 2023

Engineering activities aim to satisfy the demands of society. Not only should the economic and technological aspects be considered, but also the socio-environmental impact. In this sense, the development of composites with the incorporation of waste has been highlighted, aiming not only for better and/or cheaper materials, but also optimizing the use of natural resources. To obtain better results using industrial agro waste, we need to treat this waste to incorporate engineered composites and obtain the optimal results for each application desired. The objective of this work is to compare the effect of processing coconut husk particulates on the mechanical and thermal behavior of epoxy matrix composites, since we will need a smooth composite in the near future to be applied by brushes and sprayers with a high quality surface finish. This processing was carried out in a ball mill for 24 h. The matrix was a Bisphenol A diglycidyl ether (DGEBA)/triethylenetetramine (TETA) epoxy system. The tests that were performed were resistance to impact and compression, as well as the linear expansion test. Through this work, it can be observed that the processing of coconut husk powder was beneficial, allowing not only positive improvements to the properties of the composite, but also a better workability and wettability of the particulates, which was attributed to the change in the average size and shape of particulates. That means that the composites with processed coconut husk powders have improved impact strength (46 up to 51%) and compressive strength (88 up to 334%), in comparison with unprocessed particles.
Scanning Electron Microscopy of Conjunctival Scraping: Our Experience in the Diagnosis of Infectious Keratitis with Negative Culture Tests
Authors: Troisi Mario , Del Prete Salvatore , Troisi Salvatore , Marasco Daniela , Costagliola Ciro
Published: February 2023

65 consecutive patients with presumed microbial keratitis and negative culture tests for bacteria and fungi obtained by corneal curettage were evaluated. All patients had undergone local broad spectrum antibiotic therapy for at least 5 days with no clinical improvement. After 48–72 h of wash-out they underwent scraping of the superior tarsal conjunctiva for cytological examination of cellular morphology in Scanning Electron Microscopy (SEM). The presence of pathogenic microorganisms was detected with this method in 62 of these patients, towards which specific therapy was carried out. Clinical improvement and eradication of microorganisms previously detected by SEM examination were observed in all positive patients over a time between 10 and 49 days. In three patients, no microorganisms were detected, but the presence of inflammatory cells (eosinophils and mast cells) or dry eye findings. This method could be useful to detect the presence of non-isolated microorganisms at common culture tests. The resolution of the infectious keratitis and the eradication of the pathogens at the subsequent cytological examination of cellular morphology in Scanning Electron Microscopy support the validity of the proposed method.
Interpretation of Latent Codes in InfoGAN with SAR Images
Authors: Feng Zhenpeng , Daković Miloš , Ji Hongbing , Zhou Xianda , Zhu Mingzhe , Cui Xiyang , Stanković Ljubiša
Published: February 2023

Generative adversarial networks (GANs) can synthesize abundant photo-realistic synthetic aperture radar (SAR) images. Some modified GANs (e.g., InfoGAN) are even able to edit specific properties of the synthesized images by introducing latent codes. It is crucial for SAR image synthesis since the targets in real SAR images have different properties due to the imaging mechanism. Despite the success of the InfoGAN in manipulating properties, there still lacks a clear explanation of how these latent codes affect synthesized properties; thus, editing specific properties usually relies on empirical trials, which are unreliable and time-consuming. In this paper, we show that latent codes are almost disentangled to affect the properties of SAR images in a nonlinear manner. By introducing some property estimators for latent codes, we are able to decompose the complex causality between latent codes and different properties. Both qualitative and quantitative experimental results demonstrate that the property value can be computed by the property estimators; inversely, the required latent codes can be computed given the desired properties. Unlike the original InfoGAN, which only provides the visual trend between properties and latent codes, the properties of SAR images can be manipulated numerically by latent codes as users expect.
Monitoring the Spatiotemporal Dynamics of Arctic Winter Snow/Ice with Moonlight Remote Sensing: Systematic Evaluation in Svalbard
Authors: Liu Di , Shen Yanyun , Wang Yiwen , Wang Zhipan , Mo Zewen , Zhang Qingling
Published: February 2023

Accurate monitoring of the spatiotemporal dynamics of snow and ice is essential for under-standing and predicting the impacts of climate change on Arctic ecosystems and their feedback on global climate. Traditional optical and Synthetic Aperture Radar (SAR) remote sensing still have limitations in the long-time series observation of polar regions. Although several studies have demonstrated the potential of moonlight remote sensing for mapping polar snow/ice covers, systematic evaluation on applying moonlight remote sensing to monitoring spatiotemporal dynamics of polar snow/ice covers, especially during polar night periods is highly demanded. Here we present a systematic assessment in Svalbard, Norway and using data taken from the Visible Infrared Imaging Radiometer Suite (VIIRS) on the Suomi National Polar-orbiting Partnership (SNPP) Day/Night Band (DNB) sensor to monitor the spatiotemporal dynamics of snow/ice covers during dark Arctic winters when no solar illumination available for months. We successfully revealed the spatiotemporal dynamics of snow/ice covers from 2012 to 2022 during polar night/winter periods, using the VIIRS/DNB time series data and the object-oriented Random Forests (RF) algorithm, achieving the average accuracy and kappa coefficient of 96.27% and 0.93, respectively. Our findings indicate that the polar snow/ice covers show seasonal and inter-seasonal dynamics, thus requiring more frequent observations. Our results confirm and realize the potential of moonlight remote sensing for continuous monitoring of snow/ice in the Arctic region and together with other types of remote sensing data, moonlight remote sensing will be a very useful tool for polar studies and climate change.
Infrared Small Marine Target Detection Based on Spatiotemporal Dynamics Analysis
Authors: Dang Chujia , Li Zhengzhou , Hao Congyu , Xiao Qin
Published: February 2023

It is a big challenge to detect and track small infrared marine targets in non-stationary and time-varying sea clutter because the signal is too strong to be estimated. Based on the phenomenon that sea clutter spreads not only in the temporal domain but also in the spatial domain, this paper proposes an infrared small marine target detection algorithm based on spatiotemporal dynamics analysis to improve the performances of sea clutter suppression and target detection. The moving sea clutter is modeled as the spatial-temporal phase space, and the dynamical parameters of the sea clutter in the spatiotemporal domain are extracted from the sea clutter image sequence. Afterwards, the temporal dynamics reconstruction function and the spatial dynamics reconstruction function are built based on these extracted dynamical parameters. Furthermore, the space-time coupling coefficient and the spatiotemporal dynamics reconstruction function are estimated by means of a radial basis function (RBF) neural network to reconstruct the propagation regularity of the moving sea clutter. Finally, the sea clutter is suppressed by subtracting the estimated image from the original image, and then the target is detected in the suppressed image using the constant false alarm rate (CFAR) criteria. Some experiments on the small marine target in various fluctuating sea clutter image sequences are induced, and the experimental results show that the proposed algorithm could achieve outstanding performances in sea clutter suppression and small target detection.
A Random Forest-Based Multi-Index Classification (RaFMIC) Approach to Mapping Three-Decadal Inundation Dynamics in Dryland Wetlands Using Google Earth Engine
Authors: Senanayake Indishe P. , Yeo In-Young , Kuczera George A.
Published: February 2023

Australian inland riparian wetlands located east of the Great Dividing Range exhibit unique, hydroecological characteristics. These flood-dependent aquatic systems located in water-limited regions are declining rapidly due to the competitive demand for water for human activities, as well as climate change and variability. However, there exist very few reliable data to characterize inundation change conditions and quantify the impacts of the loss and deterioration of wetlands. A long-term time record of wetland inundation maps can provide a crucial baseline to monitor, assess, and assist the management and conservation of wetland ecosystems. This study presents a random forest-based multi-index classification algorithm (RaFMIC) on the Google Earth Engine (GEE) platform to efficiently construct a temporally dense, three-decadal time record of inundation maps of the southeast Australian riparian inland wetlands. The method was tested over the Macquarie Marshes located in the semiarid region of NSW, Australia. The results showed a good accuracy when compared against high-spatial resolution imagery. The total inundated area was consistent with precipitation and streamflow patterns, and the temporal dynamics of vegetation showed good agreement with the inundation maps. The inundation time record was analysed to generate inundation probability maps, which were in a good agreement with frequently flooded areas simulated by a hydrodynamic model and the distribution of flood-dependent vegetation species. The long-term, time-dense inundation maps derived from the RaFMIC method can provide key information to assess the condition and health of wetland ecosystems and have the potential to improve wetland inventory with spatially explicit water regime information. RaFMIC can be adapted over other dryland wetlands, as an effective semiautomated method of mapping long-term inundation dynamics.
Height Measurement for Meter Wave Polarimetric MIMO Radar with Electrically Long Dipole under Complex Terrain
Authors: Song Yuwei , Zheng Guimei
Published: February 2023

Height measurement of meter wave radar is a difficult and important problem. This paper studies the height measurement of meter wave polarimetric (MWP)-MIMO array radar under complex terrain. The traditional electrically short dipole has low radiation efficiency, and the collocated dipole vector antenna has strong mutual coupling. This paper proposes to use electrically long dipoles and separated vector antennae to solve the problems of low radiation efficiency and strong mutual coupling. In addition, different from the traditional flat terrain, the research of this paper is based on the conditions of complex undulating terrain. First, the height measurement signal model of the MWP-MIMO radar with separated electrically long dipole under the complex terrain is derived. Then, a preprocessing method of block orthogonal matching pursuit is proposed to obtain the coarse estimation of the target’s elevation. Then, under the guidance of the coarse estimation, the generalized MUSIC algorithm is used to obtain the high-precision elevation estimation of the target, and then the height measurement of the target is obtained according to the geometric relationship. Finally, the effectiveness of the proposed algorithm is proved by computer simulations.
Random Forest Classification of Multitemporal Landsat 8 Spectral Data and Phenology Metrics for Land Cover Mapping in the Sonoran and Mojave Deserts
Authors: Melichar Madeline , Didan Kamel , Barreto-Muñoz Armando , Duberstein Jennifer N. , Jiménez Hernández Eduardo , Crimmins Theresa , Li Haiquan , Traphagen Myles , Thomas Kathryn A. , Nagler Pamela L.
Published: February 2023

Geospatial data and tools evolve as new technologies are developed and landscape change occurs over time. As a result, these data may become outdated and inadequate for supporting critical habitat-related work across the international boundary in the Sonoran and Mojave Deserts Bird Conservation Region (BCR 33) due to the area’s complex vegetation communities and the discontinuity in data availability across the United States (US) and Mexico (MX) border. This research aimed to produce the first 30 m continuous land cover map of BCR 33 by prototyping new methods for desert vegetation classification using the Random Forest (RF) machine learning (ML) method. The developed RF classification model utilized multitemporal Landsat 8 Operational Land Imager spectral and vegetation index data from the period of 2013–2020, and phenology metrics tailored to capture the unique growing seasons of desert vegetation. Our RF model achieved an overall classification F-score of 0.80 and an overall accuracy of 91.68%. Our results portrayed the vegetation cover at a much finer resolution than existing land cover maps from the US and MX portions of the study area, allowing for the separation and identification of smaller habitat pockets, including riparian communities, which are critically important for desert wildlife and are often misclassified or nonexistent in current maps. This early prototyping effort serves as a proof of concept for the ML and data fusion methods that will be used to generate the final high-resolution land cover map of the entire BCR 33 region.
SAR Radiometric Calibration Based on Differential Geometry: From Theory to Experimentation on SAOCOM Imagery
Authors: Imperatore Pasquale , Di Martino Gerardo
Published: February 2023

The modeling and simulation of topography-induced imaging distortions are crucial for consistent radiometric information exploitation in current and forthcoming SAR-based Earth observation missions with a high spatial and temporal resolution, with relevance in several applications. In this paper, for the first time, we specifically investigate the compensation of topography-induced radiometric distortions affecting SAR images acquired by the L-band Argentinian satellite SAOCOM. We adopt a recently developed calibration method relying on an analytical formulation derived in the rigorous framework of the differential geometry of surfaces. We first provide an original interpretation of the analytical formulation, thus providing further insights into the relevant area-stretching-based formalism. Then, the numerical implementation of the method is specialized to systematically process the data acquired by SAOCOM sensors; hence, the resulting sensor-specific prototype solution processor is employed in this study. Finally, experiments performed over a real scenario in the southern part of Italy, characterized by large topography variations, are presented and discussed, thus elucidating the effectiveness of the adopted method applied to SAOCOM images. The adopted effective SAR calibration strategy opens up the way to its operational use in large-scale SAOCOM data processing.