bluuebunny/crossref_metadata_2025 huggingface dataset:
Tunable Broadband-Narrowband and Dual-Broadband Terahertz Absorber Based on a Hybrid Metamaterial Vanadium Dioxide and Graphene
Authors: Li Jing , Liu Yanfei , Chen Yu , Chen Wenqing , Guo Honglei , Wu Qiannan , Li Mengwei
Published: January 2023

We propose a functionally tunable terahertz (THz) metamaterial absorber, which has the switching performance between broadband-narrowband and dual-broadband near-perfect absorption due to the phase transition of Vanadium dioxide (VO2) and the tunable electrical property of graphene. The switching absorption properties are verified by computer simulation technology (CST) microwave study. The simulation results show that when VO2 is in the metallic phase, over 90% broadband absorption is realized in the 3.85–6.32 THz range. When the VO2 is in the insulating phase, the absorber shows quadruple narrowband absorption. By changing the Fermi level of graphene and the conductivity of VO2, the low-frequency broadband of 3.85–6.32 THz can be switched to the high-frequency broadband of 6.92–8.92 THz, and the absorber can be switched from a quadruple narrowband to a nearly singlefold narrowband. In addition, the proposed absorber is insensitive to polarization due to its symmetry and wide incident angle. The design may have potential applications in the THz range, such as switches, electromagnetic shielding, cloaking objects, filtering, sensing, and so on.
Ultrasonic Enhancement of Chondrogenesis in Mesenchymal Stem Cells by Bolt-Clamped Langevin Transducers
Authors: Kim Jinhyuk , Bae Hyuncheol , Han Hyuk-Soo , Lee Jungwoo
Published: January 2023

We recently investigated the design and fabrication of Langevin-type transducers for therapeutic ultrasound. Effect of ultrasonic energy arising from the transducer on biological tissue was examined. In this study, the transducer was set to radiate acoustic energy to mesenchymal stem cells (MSCs) for inducing differentiation into cartilage tissue. The average chondrogenic ratio in area was 20.82% in the control group, for which no external stimulation was given. Shear stress was applied to MSCs as the contrast group, which resulted in 42.66% on average with a 25.92% minimum rate; acoustic pressure from the flat tip causing transient cavitation enhanced chondrogenesis up to 52.96%. For the round tip excited by 20 Vpp, the maximum differentiation value of 69.43% was found, since it delivered relatively high acoustic pressure to MSCs. Hence, the results from this study indicate that ultrasound pressure at the kPa level can enhance MSC chondrogenesis compared to the tens of kHz range by Langevin transducers.
Improvement of YX42° Cut LiTaO3 SAW Filters with Optical Proximity Effect Correction Method
Authors: Luo Ping , Zou Yali , Yang Xinyu , Li Juntao , Huang Xuan , Zhou Jian , Han Xing , Liu Yushuai , Liu Yuhao , Wu Tao
Published: January 2023

Due to the influence of the optical proximity effect (OPE), it is easy for a pattern of photoresistance to be inconsistent with a design pattern, thus damaging the performance of a SAW resonator. To solve this problem, this paper proposes an optimization method for SAW filters based on optical proximity correction (OPC). This method can avoid the tip discharge problem of SAW filters by suppressing the problem of rounding and shrinking of dummy electrode and electrode tail caused by OPE. This method increases the quality factor (Q) of the SAW resonator and thus decreases the insertion loss of the SAW filter. The filter increases the bandwidth by 1.8 MHz at −1.5 dB after applying the OPC method. Additionally, it improves the stability of the filter under high power conditions.
Hybrid Systems of Nanofibers and Polymeric Nanoparticles for Biological Application and Delivery Systems
Authors: Vargas-Molinero Hever Yuritzy , Serrano-Medina Aracely , Palomino-Vizcaino Kenia , López-Maldonado Eduardo Alberto , Villarreal-Gómez Luis Jesús , Pérez-González Graciela Lizeth , Cornejo-Bravo José Manuel
Published: January 2023

Nanomedicine is a new discipline resulting from the combination of nanotechnology and biomedicine. Nanomedicine has contributed to the development of new and improved treatments, diagnoses, and therapies. In this field, nanoparticles have notable importance due to their unique properties and characteristics, which are useful in different applications, including tissue engineering, biomarkers, and drug delivery systems. Electrospinning is a versatile technique used to produce fibrous mats. The high surface area of the electrospun mats makes them suitable for applications in fields using nanoparticles. Electrospun mats are used for tissue engineering, wound dressing, water-treatment filters, biosensors, nanocomposites, medical implants, protective clothing materials, cosmetics, and drug delivery systems. The combination of nanoparticles with nanofibers creates hybrid systems that acquire properties that differ from their components’ characteristics. By utilizing nanoparticles and nanofibers composed of dissimilar polymers, the two synergize to improve the overall performance of electrospinning mats and nanoparticles. This review summarizes the hybrid systems of polymeric nanoparticles and polymeric nanofibers, critically analyzing how the combination improves the properties of the materials and contributes to the reduction of some disadvantages found in nanometric devices and systems.
Synergistic Anticandidal Activities of Greenly Synthesized ZnO Nanomaterials with Commercial Antifungal Agents against Candidal Infections
Authors: Yassin Mohamed Taha , Elgorban Abdallah M. , Al-Askar Abdulaziz A. , Sholkamy Essam Nageh , Ameen Fuad , Maniah Khalid
Published: January 2023

The high occurrence of mycological resistance to conventional antifungal agents results in significant illness and death rates among immunodeficient patients. In addition, the underprivileged therapeutic results of conventional antifungal agents, besides the potential toxicity resulting from long term therapy necessitate the fabrication of efficient antimicrobial combinations. Hence, the objective of the present investigation is to synthesize, characterize and investigate the anticandidal action of green zinc oxide nanoparticles (ZnO-NPs) formulated using Camellia sinensis leaf extract against three candidal pathogens. The eco-friendly synthesized ZnO-NPs were characterized utilizing different physicochemical methods and their anticandidal potency was tested utilizing a disk diffusion assay. In this setting, the size of the biofabricated ZnO-NPs was detected using transmission electron microscope (TEM) micrographs, recording an average particle size of 19.380 ± 2.14 nm. In addition, zeta potential analysis revealed that the ZnO-NPs surface charge was −4.72 mV. The biogenic ZnO-NPs reveal the highest anticandidal activity against the C. tropicalis strain, demonstrating relative suppressive zones measured at 35.16 ± 0.13 and 37.87 ± 0.24 mm in diameter for ZnO-NPs concentrations of 50 and 100 μg/disk, respectively. Excitingly, Candida glabrata showed a high susceptibility to the biofabricated ZnO nanomaterials at both ZnO-NPs’ concentrations (50 and 100 μg/disk) compared to the control. Moreover, the biosynthesized ZnO-NPs revealed potential synergistic effectiveness with nystatin and terbinafine antifungal agents against the concerned strains. The maximum synergistic efficiency was noticed against the C. glabrata strain, demonstrating relative synergistic percentages of 23.02 and 45.9%, respectively. The biogenic ZnO-NPs revealed no hemolytic activity against human erythrocytes revealing their biosafety and hemocompatibility. Finally, the high anticandidal effectiveness of biogenic ZnO-NPs against the concerned candidal pathogens, as well as potential synergistic patterns with conventional antifungal agents such as nystatin and terbinafine, emphasize the prospective application of these combinations for the fabrication of biocompatible and highly efficient antifungal agents.
Ultrahigh Frequency Ultrasonic Transducers (150MHz) Based on Silicon Lenses
Authors: Chen Jun , Fei Chunlong , Zhao Jianxin , Quan Yi , Wang Yecheng , Jiang Zhishui , Wen Li
Published: January 2023

Acoustic microscopes and acoustic tweezers have great value in the application of microparticle manipulation, biomedical research and non-destructive testing. Ultrahigh frequency (UHF) ultrasonic transducers act as the key component in acoustic microscopes, and acoustic tweezers and acoustic lenses are essential parts of UHF ultrasonic transducers. Therefore, the preparation of acoustic lenses is crucial. Silicon is a suitable material for preparing acoustic lenses because of its high acoustic velocity, low acoustic attenuation and excellent machinability. In previous research, silicon lenses were mainly prepared by etching. However, etching has some drawbacks. The etching of large sizes is complex, time-consuming and expensive. Furthermore, vertical etching is preferred to spherical etching. Thus, a new method of ultra-precision machining was introduced to prepare silicon lenses. In this paper, silicon lenses with an aperture of 892 μm and a depth of 252 μm were prepared. Then, UHF ultrasonic transducers with a center frequency of 157 MHz and a −6-dB bandwidth of 52% were successfully prepared based on silicon lenses. The focal distance of the transducers was 736 μm and the F-number was about 0.82. The transducers had a lateral resolution of 11 μm and could distinguish the 13 μm slots on silicon wafers clearly.
Extraction of Graphene’s RF Impedance through Thru-Reflect-Line Calibration
Authors: Colmiais Ivo , Silva Vitor , Borme Jérôme , Alpuim Pedro , Mendes Paulo M.
Published: January 2023

Graphene has unique properties that can be exploited for radiofrequency applications. Its characterization is key for the development of new graphene devices, circuits, and systems. Due to the two-dimensional nature of graphene, there are challenges in the methodology to extract relevant characteristics that are necessary for device design. In this work, the Thru-Reflect-Line (TRL) calibration was evaluated as a solution to extract graphene’s electrical characteristics from 1 GHz to 65 GHz, where the calibration structures’ requirements were analyzed. It was demonstrated that thick metallic contacts, a low-loss substrate, and a short and thin contact are necessary to characterize graphene. Furthermore, since graphene’s properties are dependent on the polarization voltage applied, a backgate has to be included so that graphene can be characterized for different chemical potentials. Such characterization is mandatory for the design of graphene RF electronics and can be used to extract characteristics such as graphene’s resistance, quantum capacitance, and kinetic inductance. Finally, the proposed structure was characterized, and graphene’s resistance and quantum capacitance were extracted.
Hardness-and-Type Recognition of Different Objects Based on a Novel Porous Graphene Flexible Tactile Sensor Array
Authors: Song Yang , Lv Shanna , Wang Feilu , Li Mingkun
Published: January 2023

Accurately recognizing the hardness and type of different objects by tactile sensors is of great significance in human–machine interaction. In this paper, a novel porous graphene flexible tactile sensor array with great performance is designed and fabricated, and it is mounted on a two-finger mechanical actuator. This is used to detect various tactile sequence features from different objects by slightly squeezing them by 2 mm. A Residual Network (ResNet) model, with excellent adaptivity and feature extraction ability, is constructed to realize the recognition of 4 hardness categories and 12 object types, based on the tactile time sequence signals collected by the novel sensor array; the average accuracies of hardness and type recognition are 100% and 99.7%, respectively. To further verify the classification ability of the ResNet model for the tactile feature information detected by the sensor array, the Multilayer Perceptron (MLP), LeNet, Multi-Channel Deep Convolutional Neural Network (MCDCNN), and ENCODER models are built based on the same dataset used for the ResNet model. The average recognition accuracies of the 4hardness categories, based on those four models, are 93.6%, 98.3%, 93.3%, and 98.1%. Meanwhile, the average recognition accuracies of the 12 object types, based on the four models, are 94.7%, 98.9%, 85.0%, and 96.4%. All of the results demonstrate that the novel porous graphene tactile sensor array has excellent perceptual performance and the ResNet model can very effectively and precisely complete the hardness and type recognition of objects for the flexible tactile sensor array.
Boosting Evaporative Cooling Performance with Microporous Aerogel
Authors: Tang Huajie , Guo Chenyue , Xu Qihao , Zhao Dongliang
Published: January 2023

Hydrogel-based evaporative cooling with a low carbon footprint is regarded as a promising technology for thermal regulation. Yet, the efficiency of hydrogel regeneration at night generally mismatches with vapor evaporation during the day, resulting in a limited cooling time span, especially in arid regions. In this work, we propose an efficient approach to improve hydrogel cooling performance, especially the cooling time span, with a bilayer structure, which comprises a bottom hydrogel layer and an upper aerogel layer. The microporous aerogel layer can reduce the saturation vapor density at the hydrogel surface by employing daytime radiative cooling, together with increased convective heat transfer resistance by thermal insulation, thus boosting the duration of evaporative cooling. Specifically, the microstructure of porous aerogel for efficient radiative cooling and vapor transfer is synergistically optimized with a cooling performance model. Results reveal that the proposed structure with a 2-mm-thick SiO2 aerogel can reduce the temperature by 1.4 °C, meanwhile extending the evaporative cooling time span by 11 times compared to a single hydrogel layer.
A Biodegradable Bioactive Glass-Based Hydration Sensor for Biomedical Applications
Authors: Gharbi Amina , Kallel Ahmed Yahia , Kanoun Olfa , Cheikhrouhou-Koubaa Wissem , Contag Christopher H. , Antoniac Iulian , Derbel Nabil , Ashammakhi Nureddin
Published: January 2023

Monitoring changes in edema-associated intracranial pressure that complicates trauma or surgery would lead to improved outcomes. Implantable pressure sensors have been explored, but these sensors require post-surgical removal, leading to the risk of injury to brain tissue. The use of biodegradable implantable sensors would help to eliminate this risk. Here, we demonstrate a bioactive glass (BaG)-based hydration sensor. Fluorine (CaF2) containing BaG (BaG-F) was produced by adding 5, 10 or 20 wt.% of CaF2 to a BaG matrix using a melting manufacturing technique. The structure, morphology and electrical properties of the resulting constructs were evaluated to understand the physical and electrical behaviors of this BaG-based sensor. Synthesis process for the production of the BaG-F-based sensor was validated by assessing the structural and electrical properties. The structure was observed to be amorphous and dense, the porosity decreased and grain size increased with increasing CaF2 content in the BaG matrix. We demonstrated that this BaG-F chemical composition is highly sensitive to hydration, and that the electrical sensitivity (resistive–capacitive) is induced by hydration and reversed by dehydration. These properties make BaG-F suitable for use as a humidity sensor to monitor brain edema and, consequently, provide an alert for increased intracranial pressure.
Measurement and Control System for Atomic Force Microscope Based on Quartz Tuning Fork Self-Induction Probe
Authors: Luo Yongzhen , Ding Xidong , Chen Tianci , Su Tao , Chen Dihu
Published: January 2023

In this paper, we introduce a low-cost, expansible, and compatible measurement and control system for atomic force microscopes (AFM) based on a quartz tuning fork (QTF) self-sensing probe and frequency modulation, which is mainly composed of an embedded control system and a probe system. The embedded control system is based on a dual-core OMAPL138 microprocessor (DSP + ARM) equipped with 16 channels of a 16-bit high-precision general analog-to-digital converter (ADC) and a 16-bit high-precision general digital-to-analog converter (DAC), six channels of an analog-to-digital converter with a second-order anti-aliasing filter, four channels of a direct digital frequency synthesizer (DDS), a digital input and output (DIO) interface, and other peripherals. The uniqueness of the system hardware lies in the design of a high-precision and low-noise digital—analog hybrid lock-in amplifier (LIA), which is used to detect and track the frequency and phase of the QTF probe response signal. In terms of the system software, a software difference frequency detection method based on a digital signal processor (DSP) is implemented to detect the frequency change caused by the force gradient between the tip and the sample, and the relative error of frequency measurement is less than 3%. For the probe system, a self-sensing probe controller, including an automatic gain control (AGC) self-excitation circuit, is designed for a homemade balanced QTF self-sensing probe with a high quality factor (Q value) in an atmospheric environment. We measured the quality factor (Q value) of the balanced QTF self-sensing probes with different lengths of tungsten tips and successfully realized AFM topography imaging with a tungsten-tip QTF probe 3 mm in length. The results show that the QTF-based self-sensing probe and the developed AFM measurement and control system can obtain high quality surface topography scanning images in an atmospheric environment.
Synthesis, Characterization, and Acute Cytotoxicity Evaluation of Chloroquine Encapsulating Liposomes
Authors: Donahue Nathan D. , Vance Ellen A. , Sheth Vinit , Francek Emmy R. , Wilhelm Stefan
Published: January 2023

Liposomes encapsulating chloroquine were synthesized and characterized. Cryogenic transmission electron microscopy and dynamic light scattering confirmed a liposome size of ~100 nm and uniform shape. Two independent analytical methods were used to quantify chloroquine encapsulation: (i) HPLC, and (ii) UV-Vis spectrophotometry. Using RAW264.7 murine macrophages as model immune cells, cell culture experiments revealed an improved acute cytotoxicity profile of chloroquine encapsulating liposomes with >90% cell viability compared to free chloroquine (cell viability ~30%) at equivalent drug doses. These results may potentially be relevant for liposome-based chloroquine delivery for nanomedicine applications.
Volcano–Plutonic Complex of the Tumrok Range (Eastern Kamchatka): An Example of the Ural-Alaskan Type Intrusion and Related Volcanic Series
Authors: Chayka Ivan F. , Baykov Nikolay I. , Kamenetsky Vadim S. , Kutyrev Anton V. , Pushkarev Evgenii V. , Abersteiner Adam , Shcherbakov Vasily D.
Published: January 2023

Zoned plutons, composed of dunites, pyroxenites, and gabbroic rocks, have been referred to as the Ural-Alaskan type complexes (UA-complexes) and occur in numerous paleo-arc settings worldwide. Many of these complexes are source rocks for economic placers of platinum-group metals. Thus, it is important to understand how UA-complexes form and the origin and behavior of platinum-group elements (PGEs). It is widely assumed that the UA-complexes result from differentiation of supra-subduction high-Ca high-Mg sub-alkaline magmas. However, there is a lack of direct evidence for the existence and differentiation of such magmas, mainly because cases of UA-complexes being spatially and temporally linked to co-genetic volcanics are unknown. We studied an UA-complex from the Tumrok range (Eastern Kamchatka) where a dunite-clinopyroxenite-gabbro assemblage is spatially and temporary related to high-Ca volcanics (i.e., picrites and basalts). Based on the mineral and chemical composition of the rocks, mineral chemistry, and composition of melt inclusions hosted within rock-forming minerals, we conclude that the intrusive assemblage and the volcanics are co-genetic and share the same parental magma of ankaramitic composition. Furthermore, the compositions of the plutonic rocks are typical of UA-complexes worldwide. Finally, the rocks studied exhibit a full differentiation sequence from olivine-only liquidus in picrites and dunites to eutectic crystallization of diopside or hornblende, plagioclase, and K-Na feldspar in plagio-wehrlites and gabbroic rocks. All these results make the considered volcano–plutonic complex a promising case for petrological studies and modelling of UA-complex formation.
Genomics-Driven Discovery of Benzoxazole Alkaloids from the Marine-Derived Micromonospora sp. SCSIO 07395
Authors: Cheng Ziqian , Zhang Qingbo , Peng Jing , Zhao Xiaoyang , Ma Liang , Zhang Changsheng , Zhu Yiguang
Published: January 2023

Benzoxazole alkaloids exhibit a diverse array of structures and interesting biological activities. Herein we report the identification of a benzoxazole alkaloid-encoding biosynthetic gene cluster (mich BGC) in the marine-derived actinomycete Micromonospora sp. SCSIO 07395 and the heterologous expression of this BGC in Streptomyces albus. This approach led to the discovery of five new benzoxazole alkaloids microechmycin A–E (1–5), and a previously synthesized compound 6. Their structures were elucidated by HRESIMS and 1D and 2D NMR data. Microechmycin A (1) showed moderate antibacterial activity against Micrococcus luteus SCSIO ML01 with the minimal inhibitory concentration (MIC) value of 8 μg mL−1.
Metabolite Variation between Nematode and Bacterial Seed Galls in Comparison to Healthy Seeds of Ryegrass Using Direct Immersion Solid-Phase Microextraction (DI-SPME) Coupled with GC-MS
Authors: Koli Pushpendra , Agarwal Manjree , Kessell David , Mahawar Shalini , Du Xin , Ren Yonglin , McKirdy Simon J.
Published: January 2023

Annual ryegrass toxicity (ARGT) is an often-fatal poisoning of livestock that consume annual ryegrass infected by the bacterium Rathayibacter toxicus. This bacterium is carried into the ryegrass by a nematode, Anguina funesta, and produces toxins within seed galls that develop during the flowering to seed maturity stages of the plant. The actual mechanism of biochemical transformation of healthy seeds to nematode and bacterial gall-infected seeds remains unclear and no clear-cut information is available on what type of volatile organic compounds accumulate in the respective galls. Therefore, to fill this research gap, the present study was designed to analyze the chemical differences among nematode galls (A. funesta), bacterial galls (R. toxicus) and healthy seeds of annual ryegrass (Lolium rigidum) by using direct immersion solid-phase microextraction (DI-SPME) coupled with gas chromatography–mass spectrometry (GC-MS). The method was optimized and validated by testing its linearity, sensitivity, and reproducibility. Fifty-seven compounds were identified from all three sources (nematode galls, bacterial galls and healthy seed), and 48 compounds were found to be present at significantly different (p < 0.05) levels in the three groups. Five volatile organic compounds (hexanedioic acid, bis(2-ethylhexyl) ester), (carbonic acid, but-2-yn-1-yl eicosyl ester), (fumaric acid, 2-ethylhexyl tridec-2-yn-1-yl ester), (oct-3-enoylamide, N-methyl-N-undecyl) and hexacosanoic acid are the most frequent indicators of R. toxicus bacterial infection in ryegrass, whereas the presence of 15-methylnonacosane, 13-methylheptacosane, ethyl hexacosyl ether, heptacosyl acetate and heptacosyl trifluoroacetate indicates A. funesta nematode infestation. Metabolites occurring in both bacterial and nematode galls included batilol (stearyl monoglyceride) and 9-octadecenoic acid (Z)-, tetradecyl ester. Among the chemical functional group, esters, fatty acids, and alcohols together contributed more than 70% in healthy seed, whereas this contribution was 61% and 58% in nematode and bacterial galls, respectively. This study demonstrated that DI-SPME is a valid technique to study differentially expressed metabolites in infected and healthy ryegrass seed and may help provide better understanding of the biochemical interactions between plant and pathogen to aid in management of ARGT.
Synthesis of Novel Polymer-Assisted Organic-Inorganic Hybrid Nanoflowers and Their Application in Cascade Biocatalysis
Authors: Braz Joana F. , Dencheva Nadya V. , Malfois Marc , Denchev Zlatan Z.
Published: January 2023

This study reports on the synthesis of novel bienzyme polymer-assisted nanoflower complexes (PANF), their morphological and structural characterization, and their effectiveness as cascade biocatalysts. First, highly porous polyamide 6 microparticles (PA6 MP) are synthesized by activated anionic polymerization in solution. Second, the PA6 MP are used as carriers for hybrid bienzyme assemblies comprising glucose oxidase (GOx) and horseradish peroxidase (HRP). Thus, four PANF complexes with different co-localization and compartmentalization of the two enzymes are prepared. In samples NF GH/PA and NF GH@PA, both enzymes are localized within the same hybrid flowerlike organic-inorganic nanostructures (NF), the difference being in the way the PA6 MP are assembled with NF. In samples NF G/PAiH and NF G@PAiH, only GOx is located in the NF, while HRP is preliminary immobilized on PA6 MP. The morphology and the structure of the four PANF complexes have been studied by microscopy, spectroscopy, and synchrotron X-ray techniques. The catalytic activity of the four PANF was assessed by a two-step cascade reaction of glucose oxidation. The PANF complexes are up to 2–3 times more active than the free GOx/HRP dyad. They also display enhanced kinetic parameters, superior thermal stability in the 40–60 °C range, optimum performance at pH 4–6, and excellent storage stability. All PANF complexes are active for up to 6 consecutive operational cycles.
Novel 9-Benzylaminoacridine Derivatives as Dual Inhibitors of Phosphodiesterase 5 and Topoisomerase II for the Treatment of Colon Cancer
Authors: Ammar Lina , Lin Hung-Yu , Shih Shou-Ping , Tsai Tsen-Ni , Syu Yu-Ting , Abdel-Halim Mohammad , Hwang Tsong-Long , Abadi Ashraf H.
Published: January 2023

It has been shown that phosphodiesterase 5 (PDE5) inhibitors have anticancer effects in a variety of malignancies in both in vivo and in vitro experiments. The role of cGMP elevation in colorectal carcinoma (CRC) has been extensively studied. Additionally, DNA topoisomerase II (Topo II) inhibition is a well-established mechanism of action that mediates the effects of several approved anticancer drugs such as doxorubicin and mitoxantrone. Herein, we present 9-benzylaminoacridine derivatives as dual inhibitors of the PDE5 and Topo II enzymes. We synthesized 31 derivatives and evaluated them against PDE5, whereby 22 compounds showed micromolar or sub-micromolar inhibition. The anticancer activity of the compounds was evaluated with the NCI 60-cell line testing. Moreover, the effects of the compounds on HCT-116 colorectal carcinoma (CRC) were extensively studied, and potent compounds against HCT-116 cells were studied for their effects on Topo II, cell cycle progression, and apoptosis. In addition to exhibiting significant growth inhibition against HCT116 cells, compounds 11, 12, and 28 also exhibited the most superior Topo II inhibitory activity and low micromolar PDE5 inhibition and affected cell cycle progression. Knowing that compounds that combat cancer through multiple mechanisms are among the best candidates for effective therapy, we believe that the current class of compounds merits further optimization and investigation to unleash their full therapeutic potential.
Microencapsulation by a Spray Drying Approach to Produce Innovative Probiotics-Based Products Extending the Shelf-Life in Non-Refrigerated Conditions
Authors: Gullifa Giuseppina , Risoluti Roberta , Mazzoni Cristina , Barone Laura , Papa Elena , Battistini Alfredo , Martin Fraguas Rodrigo , Materazzi Stefano
Published: January 2023

Recently, there has been a growing interest in producing functional foods containing encapsulated probiotic bacteria due to their positive effects on human health. According to their perceived health benefits, probiotics have been incorporated into a range of dairy products, but the current major challenge is to market new, multicomponent probiotic foods and supplements. Nevertheless, only a few products containing encapsulated probiotic cells can be found as non-refrigerated products. In this work, spray drying technology was investigated in order to produce an innovative nutraceutical formulation based on lactic acid bacteria (LAB), and was able to ensure a good storage stability of probiotics (no less than 109 CFU/cps) in non-refrigerated conditions. Probiotic-loaded microparticles from spray drying experiments were produced under different conditions and compared by thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and the enumeration of the number of viable cells in order to identify the formulation exhibiting the most promising characteristics. Results from the dissolution test revealed that the optimized formulation provides a suitable amount of living cells after digestion of microparticles stored for 12 months at room temperature and confirmed that the microencapsulation process by spray drying ensures a good protection of probiotics for nutraceutical purposes.
Novel Antioxidant Peptides from Pearl Shell Meat Hydrolysate and Their Antioxidant Activity Mechanism
Authors: Huang Pantian , Miao Jianyin , Li Jialing , Li Yingkun , Wang Xianghua , Yu Yan , Cao Yong
Published: January 2023

Free radicals are associated with aging and many diseases. Antioxidant peptides with good antioxidant activity and absorbability are one of the hotspots in antioxidant researches. In our study, pearl shell (Pinctada martensii) meat hydrolysate was purified, and after identification by proteomics, six novel antioxidant peptides SPSSS, SGTAV, TGVAS, GGSIT, NSVAA, and GGSLT were screened by bioinformatics analysis. The antioxidant peptides exhibited good cellular antioxidant activity (CAA) and the CAA of SGTAV (EC50: 0.009 mg/mL) and SPSSS (EC50: 0.027 mg/mL) were better than that of positive control GSH (EC50: 0.030 mg/mL). In the AAPH-induced oxidative damage models, the antioxidant peptides significantly increased the viability of HepG2 cells, and the cell viability of SGTAV, SPSSS, and NAVAA were significantly restored from 79.41% to 107.43% and from 101.09% and 100.09%, respectively. In terms of antioxidant mechanism by molecular docking, SGTAV, SPSSS, and NAVAA could tightly bind to free radicals (DPPH and ABTS), antioxidant enzymes (CAT and SOD), and antioxidant channel protein (Keap1), suggesting that the antioxidant peptides had multiple antioxidant activities and had structure–activity linkages. This study suggests that the antioxidant peptides above are expected to become new natural materials for functional food industries, which contribute to the high-value applications of pearl shell meat.
Development of [124/125I]IAZA as a New Proteinopathy Imaging Agent for Alzheimer’s Disease
Authors: Reddy Thrisha T. , Iguban Michael H. , Melkonyan Lusine L. , Shergill Jasmine , Liang Christopher , Mukherjee Jogeshwar
Published: January 2023

Radioiodinated imaging agents for Aβ amyloid plaque imaging in Alzheimer’s disease (AD) patients have not been actively pursued. Our previous studies employed the “diaza” derivatives [11C]TAZA and [18F]flotaza in order to develop successful positron emission tomography (PET) imaging agents for Aβ plaques. There is a need for radioiodinated imaging agents for Aβ plaques for single photon emission computed tomography (SPECT) and PET imaging. We report our findings on the preparation of [124/125I]IAZA, a “diaza” analog of [11C]TAZA and [18F]flotaza, and the evaluation of binding to Aβ plaques in the postmortem human AD brain. The binding affinity of IAZA for Aβ plaques was Ki = 10.9 nM with weak binding affinity for neurofibrillary tangles (Ki = 3.71 μM). Both [125I]IAZA and [124I]IAZA were produced in >25% radiochemical yield and >90% radiochemical purity. In vitro binding of [125I]IAZA and [124I]IAZA in postmortem human AD brains was higher in gray matter containing Aβ plaques compared to white matter (ratio of gray to white matter was >7). Anti-Aβ immunostaining strongly correlated with [124/125I]IAZA in postmortem AD human brains. The binding of [124/125I]IAZA in postmortem human AD brains was displaced by the known Aβ plaque imaging agents. Thus, radiolabeled [124/123I]IAZA may potentially be a useful PET or SPECT radioligand for Aβ plaques in brain imaging studies.
Research and Application of Kupffer Cell Thresholds for BSA Nanoparticles
Authors: Guo Huanhuan , Tai Zongguang , Liu Fang , Tian Jing , Ding Nan , Chen Zhongjian , Gao Shen
Published: January 2023

Over the past decade, the dose of nanoparticles given to solid tumors has remained at a median of 0.7% of the injected dose. Most nanoparticles are trapped in a mononuclear phagocyte system (MPS), of which 85% are Kupffer cells. In our study, threshold doses of bovine serum albumin (BSA) nanoparticles were investigated for the uptake of Kupffer cells in vitro and in vivo. The antitumor effect and safety of albumin-bound paclitaxel (ABP) were improved by using threshold doses of BSA nanoparticles. We found a threshold dose of 20,000 nanoparticles per macrophage uptake in vitro and a saturation dose of 0.3 trillion nanoparticles in tumor-bearing mice. In vivo efficacy and safety evaluations demonstrated that the threshold doses of blank BSA nanoparticles could significantly improve the efficacy and safety of ABP against tumors compared with ABP alone. In this study, the delivery efficiency of ABP was improved by using blank nanoparticles to saturate Kupffer cells, which provided a new approach to studying the Kupffer cell saturation threshold and thus a new scheme for improving the curative effect of ABP.
Determination of Free Histidine in Complex Hair Care Products with Minimum Sample Preparation Using Cation-Exchange Chromatography and Post Column Derivatization
Authors: Tsiasioti Apostolia , Zacharis Constantinos K. , Tzanavaras Paraskevas D.
Published: January 2023

In this communication, we describe the first analytical method for the determination of free histidine in hair care products (shampoos and conditioners). Cation-exchange chromatography combined with postcolumn derivatization and fluorimetric detection enabled the accurate (recovery: 83.5–114.8%) and precise (2.4–5.6% RSD) determination of free histidine without matrix interferences at concentration levels down to 1.5 mg kg−1. Real commercially available samples were found to contain the amino acid at levels ranging between 70 and 535 mg kg−1.
A Bridge too Far? Comparison of Transition Metal Complexes of Dibenzyltetraazamacrocycles with and without Ethylene Cross-Bridges: X-ray Crystal Structures, Kinetic Stability, and Electronic Properties
Authors: Walker Ashlie N. , Ayala Megan A. , Mondal Somrita , Bergagnini Mackenzie C. , Bui Phuong John D. , Chidester Stephanie N. , Doeden Chad I. , Esjornson Louise , Sweany Brian R. , Garcia Leslie , Krause Jeanette A. , Oliver Allen G. , Prior Timothy J. , Hubin Timothy J.
Published: January 2023

Tetraazamacrocycles, cyclic molecules with four nitrogen atoms, have long been known to produce highly stable transition metal complexes. Cross-bridging such molecules with two-carbon chains has been shown to enhance the stability of these complexes even further. This provides enough stability to use the resulting compounds in applications as diverse and demanding as aqueous, green oxidation catalysis all the way to drug molecules injected into humans. Although the stability of these compounds is believed to result from the increased rigidity and topological complexity imparted by the cross-bridge, there is insufficient experimental data to exclude other causes. In this study, standard organic and inorganic synthetic methods were used to produce unbridged dibenzyl tetraazamacrocycle complexes of Co, Ni, Cu, and Zn that are analogues of known cross-bridged tetraazamacrocycles and their transition metal complexes to allow direct comparison of molecules that are identical except for the cross-bridge. The syntheses of the known tetraazamacrocycles and the new transition metal complexes were successful with high yields and purity. Initial chemical characterization of the complexes was conducted by UV-Visible spectroscopy, while cyclic voltammetry showed more marked differences in electronic properties from bridged versions. Direct comparison studies of the unbridged and bridged compounds’ kinetic stabilities, as demonstrated by decomposition using high acid concentration and elevated temperature, showed that the cyclen-based complex stability did not benefit from cross-bridging. This is likely due to poor complementarity with the Cu2+ ion while cyclam-based complexes benefited greatly. We conclude that ligand–metal complementarity must be maintained in order for the topological and rigidity constraints imparted by the cross-bridge to contribute significantly to complex robustness.
The Entrapment and Concentration of SARS-CoV-2 Particles with Graphene Oxide: An In Vitro Assay
Authors: Parra Beatriz , Contreras Adolfo , Mina José Herminsul , Valencia Mayra Eliana , Grande-Tovar Carlos David , Valencia Carlos Humberto , Ramírez Cristina , Bolívar Germán Armando
Published: January 2023

Previous studies have suggested that graphene oxide (GO) has some antiviral capacity against some enveloped viruses, including SARS-CoV-2. Given this background, we wanted to test the in vitro antiviral ability to GO using the viral plaque assay technique. Two-dimensional graphene oxide (GO) nanoparticles were synthesized using the modified Hummers method, varying the oxidation conditions to achieve nanoparticles between 390 and 718 nm. The antiviral activity of GO was evaluated by experimental infection and plaque formation units assay of the SARS-CoV-2 virus in VERO cells using a titrated viral clinical isolate. It was found that GO at concentrations of 400 µg/mL, 100 µg/mL, 40 µg/mL, and 4 µg/mL was not toxic to cell culture and also did not inhibit the infection of VERO cells by SARS-CoV-2. However, it was evident that GO generated a novel virus entrapment phenomenon directly proportional to its concentration in the suspension. Similarly, this effect of GO was maintained in assays performed with the Zika virus. A new application for GO nanoparticles is proposed as part of a system to trap viruses in surgical mask filters, air conditioning equipment filters, and air purifier filters, complemented with the use of viricidal agents that can destroy the trapped viruses, an application of broad interest for human beings.
Numerical and Experimental Study of Colored Magnetic Particle Mapping via Magnetoelectric Sensors
Authors: Friedrich Ron-Marco , Sadeghi Mohammad , Faupel Franz
Published: January 2023

Colored imaging of magnetic nanoparticles (MNP) is a promising noninvasive method for medical applications such as therapy and diagnosis. This study investigates the capability of the magnetoelectric sensor and projected gradient descent (PGD) algorithm for colored particle detection. In the first step, the required circumstances for image reconstruction are studied via a simulation approach for different signal-to-noise ratios (SNR). The spatial accuracy of the reconstructed image is evaluated based on the correlation coefficient (CC) factor. The inverse problem is solved using the PGD method, which is adapted according to a nonnegativity constraint in the complex domain. The MNP characterizations are assessed through a magnetic particle spectrometer (MPS) for different types. In the experimental investigation, the real and imaginary parts of the MNP’s response are used to detect the spatial distribution and particle type, respectively. The experimental results indicate that the average phase difference for CT100 and ARA100 particles is 14 degrees, which is consistent with the MPS results and could satisfy the system requirements for colored imaging. The experimental evaluation showed that the magnetoelectric sensor and the proposed approach could be potential candidates for color bio-imaging applications.
Nanostructured Calcium-Incorporated Surface Compared to Machined and SLA Dental Implants—A Split-Mouth Randomized Case/Double-Control Histological Human Study
Authors: Makary Christian , Menhall Abdallah , Lahoud Pierre , An Hyun-Wook , Park Kwang-Bum , Traini Tonino
Published: January 2023

Background: Implant surface topography is a key element in achieving osseointegration. Nanostructured surfaces have shown promising results in accelerating and improving bone healing around dental implants. The main objective of the present clinical and histological study is to compare, at 4 and 6 weeks, (w) bone-to-implant contact in implants having either machined surface (MAC), sandblasted, large grit, acid-etched implant surface (SLA) medium roughness surface or a nanostructured calcium-incorporated surface (XPEED®). Methods: 35 mini-implants of 3.5 × 8.5 mm with three different surface treatments (XPEED® (n = 16)—SLA (n = 13)—MAC (n = 6), were placed in the posterior maxilla of 11 patients (6 females and 5 males) then, retrieved at either 4 or 6w in a randomized split-mouth study design. Results: The BIC rates measured at 4w and 6w respectively, were: 16.8% (±5.0) and 29.0% (±3.1) for MAC surface; 18.5% (±2.3) and 33.7% (±3.3) for SLA surface; 22.4% (±1.3) and 38.6% (±3.2) for XPEED® surface. In all types of investigated surfaces, the time factor appeared to significantly increase the bone to implant contact (BIC) rate (p < 0.05). XPEED® surface showed significantly higher BIC values when compared to both SLA and MAC values at 4w (p < 0.05). Also, at 6w, both roughened surfaces (SLA and XPEED®) showed significantly higher values (p < 0.05) than turned surface (MAC). Conclusions: Nanostructured Calcium titanate coating is able to enhance bone deposition around implants at early healing stages.
Recent Developments in DNA-Nanotechnology-Powered Biosensors for Zika/Dengue Virus Molecular Diagnostics
Authors: Park Goeun , Park Hanbin , Park Sang-Chan , Jang Moonbong , Yoon Jinho , Ahn Jae-Hyuk , Lee Taek
Published: January 2023

Zika virus (ZIKV) and dengue virus (DENV) are highly contagious and lethal mosquito-borne viruses. Global warming is steadily increasing the probability of ZIKV and DENV infection, and accurate diagnosis is required to control viral infections worldwide. Recently, research on biosensors for the accurate diagnosis of ZIKV and DENV has been actively conducted. Moreover, biosensor research using DNA nanotechnology is also increasing, and has many advantages compared to the existing diagnostic methods, such as polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA). As a bioreceptor, DNA can easily introduce a functional group at the 5′ or 3′ end, and can also be used as a folded structure, such as a DNA aptamer and DNAzyme. Instead of using ZIKV and DENV antibodies, a bioreceptor that specifically binds to viral proteins or nucleic acids has been fabricated and introduced using DNA nanotechnology. Technologies for detecting ZIKV and DENV can be broadly divided into electrochemical, electrical, and optical. In this review, advances in DNA-nanotechnology-based ZIKV and DENV detection biosensors are discussed.
Uranium Removal from Aqueous Solutions by Aerogel-Based Adsorbents—A Critical Review
Authors: Georgiou Efthalia , Raptopoulos Grigorios , Anastopoulos Ioannis , Giannakoudakis Dimitrios A. , Arkas Michael , Paraskevopoulou Patrina , Pashalidis Ioannis
Published: January 2023

Aerogels are a class of lightweight, nanoporous, and nanostructured materials with diverse chemical compositions and a huge potential for applications in a broad spectrum of fields. This has led the IUPAC to include them in the top ten emerging technologies in chemistry for 2022. This review provides an overview of aerogel-based adsorbents that have been used for the removal and recovery of uranium from aqueous environments, as well as an insight into the physicochemical parameters affecting the adsorption efficiency and mechanism. Uranium removal is of particular interest regarding uranium analysis and recovery, to cover the present and future uranium needs for nuclear power energy production. Among the methods used, such as ion exchange, precipitation, and solvent extraction, adsorption-based technologies are very attractive due to their easy and low-cost implementation, as well as the wide spectrum of adsorbents available. Aerogel-based adsorbents present an extraordinary sorption capacity for hexavalent uranium that can be as high as 8.8 mol kg–1 (2088 g kg–1). The adsorption data generally follow the Langmuir isotherm model, and the kinetic data are in most cases better described by the pseudo-second-order kinetic model. An evaluation of the thermodynamic data reveals that the adsorption is generally an endothermic, entropy-driven process (ΔH0, ΔS0 > 0). Spectroscopic studies (e.g., FTIR and XPS) indicate that the adsorption is based on the formation of inner-sphere complexes between surface active moieties and the uranyl cation. Regeneration and uranium recovery by acidification and complexation using carbonate or chelating ligands (e.g., EDTA) have been found to be successful. The application of aerogel-based adsorbents to uranium removal from industrial processes and uranium-contaminated waste waters was also successful, assuming that these materials could be very attractive as adsorbents in water treatment and uranium recovery technologies. However, the selectivity of the studied materials towards hexavalent uranium is limited, suggesting further developments of aerogel materials that could be modified by surface derivatization with chelating agents (e.g., salophen and iminodiacetate) presenting high selectivity for uranyl moieties.
Novel Research in Low-Dimensional Systems
Authors: Ciftja Orion
Published: January 2023

Low-dimensional systems exhibit unique properties that have attracted considerable attention during the last few decades [...]
Inverse Relationship between Serum 25-Hydroxyvitamin D and Elevated Intraocular Pressure
Authors: Lee Jun-Hyuk , Kwon Yu-Jin , Lee Hye Sun , Han Jee Hye , Joung Boyoung , Kim Sung Jin
Published: January 2023

Elevated intraocular pressure (EIOP) is the only major modifiable risk factor of glaucoma. While low serum vitamin D levels are considered a potential risk factor for glaucoma, there is conflicting evidence on the relationship between vitamin D and EIOP despite the possible linkage between vitamin D and intraocular pressure through oxidative stress and systemic inflammation. Therefore, the aim of this study is to verify the relationship between 25-hydroxyvitamin D [25(OH)D] and EIOP using data from 15,338 individuals who visited the health promotion center of an education hospital. The cubic spline curve revealed an inverse dose-dependent association between serum 25(OH)D level and EIOP. Using multiple logistic regression analysis, the fully adjusted odds ratio (OR) with 95% confidence interval (CI) for the EIOP of the serum 25(OH)D per increment was 0.97 (0.96–0.990). The fully adjusted ORs (95% CIs) for the EIOP of the 25(OH)D insufficiency and 25(OH)D sufficiency groups, compared to 25(OH)D deficiency group, were 0.72 (0.56–0.92) and 0.51 (0.34–0.78), respectively. The relationship remained significant in male and young age subgroups. In conclusion, the clinical assessment of intraocular pressure may prove helpful when treating patients with 25(OH)D deficiency, which may be a preventive strategy against the development of glaucoma.