bluuebunny/crossref_metadata_2025 huggingface dataset:
Mini/Micro/Nano Scale Liquid Metal Motors
Authors: Liu Li , Wang Dawei , Rao Wei
Published: March 2021

Swimming motors navigating in complex fluidic environments have received tremendous attention over the last decade. In particular, liquid metal (LM) as a new emerging material has shown considerable potential in furthering the development of swimming motors, due to their unique features such as fluidity, softness, reconfigurability, stimuli responsiveness, and good biocompatibility. LM motors can not only achieve directional motion but also deformation due to their liquid nature, thus providing new and unique capabilities to the field of swimming motors. This review aims to provide an overview of the recent advances of LM motors and compare the difference in LM macro and micromotors from fabrication, propulsion, and application. Here, LM motors below 1 cm, named mini/micro/nano scale liquid metal motors (MLMTs) will be discussed. This work will present physicochemical characteristics of LMs and summarize the state-of-the-art progress in MLMTs. Finally, future outlooks including both opportunities and challenges of mini/micro/nano scale liquid metal motors are also provided.
An Open-Source Add-On EVOM® Device for Real-Time Transepithelial/Endothelial Electrical Resistance Measurements in Multiple Transwell Samples
Authors: Raut Bibek , Chen Li-Jiun , Hori Takeshi , Kaji Hirokazu
Published: March 2021

This study provides design of a low-cost and open source add-on device that enhances the functionality of the popular EVOM® instrument for transepithelial/endothelial electrical resistance (TEER) measurement. The original EVOM® instrument is designed for measuring TEER in transwell samples manually using a pair of Ag/AgCl electrodes. The inconsistency in electrode placement, temperature variation, and a typically large (12–24 h) time interval between measurements result in large data variabilities. Thus, to solve the current limitation of the EVOM® instrument, we built an add-on device using a custom designed electronic board and a 3D printed electrode holder that allowed automated TEER measurements in multiple transwell samples. To demonstrate the functionality of the device prototype, we monitored TEER in 4 transwell samples containing retinal cells (ARPE-19) for 67 h. Furthermore, by monitoring temperature of the cell culture medium, we were able to detect fluctuations in TEER due to temperature change after the medium change process, and were able to correct the data offset. Although we demonstrated the use of our add-on device on EVOM® instrument only, the concept (multiplexing using digitally controlled relays) and hardware (custom data logger) presented here can be applied to more advanced TEER instruments to improve the performance of those devices.
Effect of Gas Annealing on the Electrical Properties of Ni/AlN/SiC
Authors: Kim Dong-Hyeon , Schweitz Michael A. , Koo Sang-Mo
Published: March 2021

It is shown in this work that annealing of Schottky barrier diodes (SBDs) in the form of Ni/AlN/SiC heterojunction devices in an atmosphere of nitrogen and oxygen leads to a significant improvement in the electrical properties of the structures. Compared to the non-annealed device, the on/off ratio of the annealed SBD devices increased by approximately 100 times. The ideality factor, derived from the current-voltage (IV) characterization, decreased by a factor of ~5.1 after annealing, whereas the barrier height increased from ~0.52 to 0.71 eV. The bonding structure of the AlN layer was characterized by X-ray photoelectron spectroscopy. Examination of the N 1 s and O 1 s peaks provided direct indication of the most prevalent chemical bonding states of the elements.
Capillary Forces between Concave Gripper and Spherical Particle for Micro-Objects Gripping
Authors: Fan Zenghua , Liu Zixiao , Huang Congcong , Zhang Wei , Lv Zhe , Wang Lefeng
Published: March 2021

The capillary action between two solid surfaces has drawn significant attention in micro-objects manipulation. The axisymmetric capillary bridges and capillary forces between a spherical concave gripper and a spherical particle are investigated in the present study. A numerical procedure based on a shooting method, which consists of double iterative loops, was employed to obtain the capillary bridge profile and bring the capillary force subject to a constant volume condition. Capillary bridge rupture was characterized using the parameters of the neck radius, pressure difference, half-filling angle, and capillary force. The effects of various parameters, such as the contact angle of the spherical concave gripper, the radius ratio, and the liquid bridge volume on the dimensionless capillary force, are discussed. The results show that the radius ratio has a significant influence on the dimensionless capillary force for the dimensionless liquid bridge volumes of 0.01, 0.05, and 0.1 when the radius ratio value is smaller than 10. The effectiveness of the theorical approach was verified using simulation model and experiments.
Development and Comparative Analysis of Electrochemically Etched Tungsten Tips for Quartz Tuning Fork Sensor
Authors: Ali Ashfaq , Ullah Naveed , Riaz Asim Ahmad , Zahir Muhammad Zeeshan , Khan Zuhaib Ali , Shah S. Shaukat Ali , Rehman Siddiqi Muftooh Ur , Hassan Muhammad Tahir
Published: March 2021

Quartz Tuning Fork (QTF) based sensors are used for Scanning Probe Microscopes (SPM), in particular for near-field scanning optical microscopy. Highly sharp Tungsten (W) tips with larger cone angles and less tip diameter are critical for SPM instead of platinum and iridium (Pt/Ir) tips due to their high-quality factor, conductivity, mechanical stability, durability and production at low cost. Tungsten is chosen for its ease of electrochemical etching, yielding high-aspect ratio, sharp tips with tens of nanometer end diameters, while using simple etching circuits and basic electrolyte chemistry. Moreover, the resolution of the SPM images is observed to be associated with the cone angle of the SPM tip, therefore Atomic-Resolution Imaging is obtained with greater cone angles. Here, the goal is to chemically etch W to the smallest possible tip apex diameters. Tips with greater cone angles are produced by the custom etching procedures, which have proved superior in producing high quality tips. Though various methods are developed for the electrochemical etching of W wire, with a range of applications from scanning tunneling microscopy (SPM) to electron sources of scanning electron microscopes, but the basic chemical etching methods need to be optimized for reproducibility, controlling cone angle and tip sharpness that causes problems for the end users. In this research work, comprehensive experiments are carried out for the production of tips from 0.4 mm tungsten wire by three different electrochemical etching techniques, that is, Alternating Current (AC) etching, Meniscus etching and Direct Current (DC) etching. Consequently, sharp and high cone angle tips are obtained with required properties where the results of the W etching are analyzed, with optical microscope, and then with field emission scanning electron microscopy (FE-SEM). Similarly, effects of varying applied voltages and concentration of NaOH solution with comparison among the produced tips are investigated by measuring their cone angle and tip diameter. Moreover, oxidation and impurities, that is, removal of contamination and etching parameters are also studied in this research work. A method has been tested to minimize the oxidation on the surface and the tips were characterized with scanning electron microscope (SEM).
Species- and Age/Generation-Dependent Adherence of Bifidobacterium bifidum to Human Intestinal Mucus In Vitro
Authors: Harata Gaku , Yoda Kazutoyo , Wang Ruipeng , Miyazawa Kenji , Sato Masayuki , He Fang , Endo Akihito
Published: March 2021

Adhesion to intestinal mucus is the first event in the process by which intestinal microbes colonize the intestine. It plays a critical role in the initiation of interactions between gut microbes and host animals. Despite the importance, the adhesion properties of probiotics are generally characterized using porcine mucin; adhesion to human mucus has been poorly characterized. In the present study, human intestinal mucus samples were isolated from 114 fecal samples collected from healthy infants and adults. In initial screening, four out of the 13 beneficial microbes tested, including the type strain of Bifidobacterium bifidum, B. bifidum TMC3115, Lacticaseibacillus rhamnosus GG, and Bifidobacterium animalis subsp. lactis Bb12, showed strong adhesion abilities to human mucus. The type strain of B. bifidum and TMC3115 adhered more strongly to neonatal and infant mucus than to adult mucus, while L. rhamnosus GG and B. lactis Bb12 adhered more strongly to adult mucus than to infant mucus. Similar results were obtained for ten additional strains of B. bifidum. In conclusion, age/generation-related differences were observed in the adhesion properties of B. bifidum and other strains. A deeper symbiotic relationship may exist between infants, particularly neonates, and B. bifidum based on its enhanced adhesion to neonatal intestinal mucus.
Insertional Inactivation of Prevotella intermedia OxyR Results in Reduced Survival with Oxidative Stress and in the Presence of Host Cells
Authors: Naito Mariko , Belvin B. Ross , Shoji Mikio , Gui Qin , Lewis Janina P.
Published: March 2021

One of the most abundant bacteria in the subgingival pockets of patients with bleeding following mechanical periodontal therapy is Prevotella intermedia. However, despite its abundance, the molecular mechanisms of its contribution to periodontal disease are not well known. This is mainly due to the lack of genetic tools that would allow examination of the role of predicted virulence factors in the pathogenesis of this bacterium. Here, we report on the first mutant in the P. intermedia OMA14 strain. The mutation is an allelic exchange replacement of the sequences coding for a putative OxyR regulator with ermF sequences coding for the macrolide–lincosamide resistance in anaerobic bacteria. The mutant is severely impaired in its ability to grow with eukaryotic cells, indicating that it is an important target for interventional strategies. Further analyses reveal that its ability to grow with oxidative stress species, in the form of hydrogen peroxide and oxygen, is severely affected. Transcriptome analysis reveals that the major deregulated genes code for the alkylhydroperoxide reductase system, AhpCF, mediating protection from peroxide stress. Moreover, genes coding for Dps, CydA and Ftn are downregulated in the mutant strain, as further verified using qRT-PCR analysis. In conclusion, we succeeded in generating the first P. intermedia mutant and show that the OxyR-deficient strain is unable to survive with a variety of host cells as well as with oxidative stress.
Persistence of Anti-SARS-CoV-2 Antibodies Depends on the Analytical Kit: A Report for Up to 10 Months after Infection
Authors: Favresse Julien , Eucher Christine , Elsen Marc , Gillot Constant , Van Eeckhoudt Sandrine , Dogné Jean-Michel , Douxfils Jonathan
Published: March 2021

Several studies have described the long-term kinetics of anti-SARS-CoV-2 antibodies but long-term follow-up data, i.e., >6 months, are still sparse. Additionally, the literature is inconsistent regarding the waning effect of the serological response. The aim of this study was to explore the temporal dynamic changes of the immune response after SARS-CoV-2 infection in hospitalized and non-hospitalized symptomatic patients over a period of 10 months. Six different analytical kits for SARS-CoV-2 antibody detection were used. Positivity rates, inter-assay agreement and kinetic models were determined. A high inter-individual and an inter-methodology variability was observed. Assays targeting total antibodies presented higher positivity rates and reached the highest positivity rates sooner compared with assays directed against IgG. The inter-assay agreement was also higher between these assays. The stratification by disease severity showed a much-elevated serological response in hospitalized versus non-hospitalized patients in all assays. In this 10-month follow-up study, serological assays showed a clinically significant difference to detect past SARS-CoV-2 infection with total antibody assays presenting the highest positivity rates. The waning effect reported in several studies should be interpreted with caution because it could depend on the assay considered.
Climate Resilience of Internally-Insulated Historic Masonry Assemblies: Comparison of Moisture Risk under Current and Future Climate Scenarios
Authors: Lu Jacqueline , Marincioni Valentina , Orr Scott Allan , Altamirano-Medina Hector
Published: March 2021

The conservation of cultural heritage built of historical brick masonry alongside meeting targets in energy reduction will most likely require widespread installation of internal wall insulation (IWI). In London, traditional buildings (pre-1919) make up 40% of the existing stock and insulating from the interior is a likely retrofit solution for solid brick walls. Adding insulation may introduce a higher risk to moisture accumulation and consequences such as mould growth and material decay. To investigate resilience to future moisture loads, three interior insulation assemblies (conforming to two U-value guidelines) were simulated in DELPHIN under reference, near-future (2040), and far-future climate (2080) scenarios. Calcium silicate, phenolic foam, and wood fibre assemblies were simulated. The reference year climate file was compiled from observed data and future files developed using the UK Climate Projections 2018 (UKCP18). Assemblies were evaluated for moisture accumulation, mould growth risk, and freeze-thaw (FT) risk. Results show low-to-medium risks in 2040 and high risks in 2080, assemblies of higher absorptivity and thinner insulation comparatively performing best. The calcium silicate assembly fared best for moisture performance; however, all assemblies will be subject to high moisture risk levels in the far future and responsible retrofits must take this and alternative design solutions into account.
The Intestinal Fatty Acid-Enteroendocrine Interplay, Emerging Roles for Olfactory Signaling and Serotonin Conjugates
Authors: Meijerink Jocelijn
Published: March 2021

Intestinal enteroendocrine cells (EECs) respond to fatty acids from dietary and microbial origin by releasing neurotransmitters and hormones with various paracrine and endocrine functions. Much has become known about the underlying signaling mechanisms, including the involvement of G-protein coupled receptors (GPCRs), like free fatty acids receptors (FFARs). This review focusses on two more recently emerging research lines: the roles of odorant receptors (ORs), and those of fatty acid conjugates in gut. Odorant receptors belong to a large family of GPCRs with functional roles that only lately have shown to reach beyond the nasal-oral cavity. In the intestinal tract, ORs are expressed on serotonin (5-HT) and glucagon-like-peptide-1 (GLP-1) producing enterochromaffin and enteroendocrine L cells, respectively. There, they appear to function as chemosensors of microbiologically produced short-, and branched-chain fatty acids. Another mechanism of fatty acid signaling in the intestine occurs via their conjugates. Among them, conjugates of unsaturated long chain fatty acids and acetate with 5-HT, N-acyl serotonins have recently emerged as mediators with immune-modulatory effects. In this review, novel findings in mechanisms and molecular players involved in intestinal fatty acid biology are highlighted and their potential relevance for EEC-mediated signaling to the pancreas, immune system, and brain is discussed.
Therapeutic Targeting of the NRF2 Signaling Pathway in Cancer
Authors: Telkoparan-Akillilar Pelin , Panieri Emiliano , Cevik Dilek , Suzen Sibel , Saso Luciano
Published: March 2021

Cancer is one of the most fatal diseases with an increasing incidence and mortality all over the world. Thus, there is an urgent need for novel therapies targeting major cancer-related pathways. Nuclear factor-erythroid 2-related factor 2 (NRF2) and its major negative modulator Kelch-like ECH-associated protein 1 (KEAP1) are main players of the cellular defense mechanisms against internal and external cell stressors. However, NRF2/KEAP1 signaling pathway is dysregulated in various cancers, thus promoting tumor cell survival and metastasis. In the present review, we discuss the mechanisms of normal and deregulated NRF2 signaling pathway focusing on its cancer-related functions. We further explore activators and inhibitors of this pathway as cancer targeting drug candidates in order to provide an extensive background on the subject.
Phase Transitions and Hysteresis for a Simple Model Liquid Crystal by Replica-Exchange Monte Carlo Simulations
Authors: Kowaguchi Akie , Brumby Paul E. , Yasuoka Kenji
Published: March 2021

In this work, the advantages of applying the temperature and pressure replica-exchange method to investigate the phase transitions and the hysteresis for liquid-crystal fluids were demonstrated. In applying this method to the commonly used Hess–Su liquid-crystal model, heat capacity peaks and points of phase co-existence were observed. The absence of a smectic phase at higher densities and a narrow range of the nematic phase were reported. The identity of the crystalline phase of this system was found to a hexagonal close-packed solid. Since the nematic-solid phase transition is strongly first order, care must be taken when using this model not to inadvertently simulate meta-stable nematic states at higher densities. In further analysis, the Weighted Histogram Analysis Method was applied to verify the precise locations of the phase transition points.
Enantioselective Synthesis of a New Non-Natural Gabosine
Authors: Colobbio Maximiliano , Pandolfi Enrique , Schapiro Valeria
Published: March 2021

The preparation of a new non-natural gabosine is reported, in which the chirality is transferred from the toluene’s biotransformed metabolite (1R,2S)-3-methylcyclohexa-3.5-diene-1,2-diol. Further chemical transformations to introduce additional functionality and chirality to the molecule were also accomplished.
Comparison of Anticoagulation Quality between Acenocoumarol and Warfarin in Patients with Mechanical Prosthetic Heart Valves: Insights from the Nationwide PLECTRUM Study
Authors: Menichelli Danilo , Poli Daniela , Antonucci Emilia , Cammisotto Vittoria , Testa Sophie , Pignatelli Pasquale , Palareti Gualtiero , Pastori Daniele ,   the Italian Federation of Anticoagulation Clinics (FCSA)
Published: March 2021

Vitamin K antagonists are indicated for the thromboprophylaxis in patients with mechanical prosthetic heart valves (MPHV). However, it is unclear whether some differences between acenocoumarol and warfarin in terms of anticoagulation quality do exist. We included 2111 MPHV patients included in the nationwide PLECTRUM registry. We evaluated anticoagulation quality by the time in therapeutic range (TiTR). Factors associated with acenocoumarol use and with low TiTR were investigated by multivariable logistic regression analysis. Mean age was 56.8 ± 12.3 years; 44.6% of patients were women and 395 patients were on acenocoumarol. A multivariable logistic regression analysis showed that patients on acenocoumarol had more comorbidities (i.e., ≥3, odds ratio (OR) 1.443, 95% confidence interval (CI) 1.081–1.927, p = 0.013). The mean TiTR was lower in the acenocoumarol than in the warfarin group (56.1 ± 19.2% vs. 61.6 ± 19.4%, p < 0.001). A higher prevalence of TiTR (<60%, <65%, or <70%) was found in acenocoumarol users than in warfarin ones (p < 0.001 for all comparisons). Acenocoumarol use was associated with low TiTR regardless of the cutoff used at multivariable analysis. A lower TiTR on acenocoumarol was found in all subgroups of patients analyzed according to sex, hypertension, diabetes, age, valve site, atrial fibrillation, and INR range. In conclusion, anticoagulation quality was consistently lower in MPHV patients on acenocoumarol compared to those on warfarin.
Towards Reversible High-Voltage Multi-Electron Reactions in Alkali-Ion Batteries Using Vanadium Phosphate Positive Electrode Materials
Authors: Boivin Edouard , Chotard Jean-Noël , Masquelier Christian , Croguennec Laurence
Published: March 2021

Vanadium phosphate positive electrode materials attract great interest in the field of Alkali-ion (Li, Na and K-ion) batteries due to their ability to store several electrons per transition metal. These multi-electron reactions (from V2+ to V5+) combined with the high voltage of corresponding redox couples (e.g., 4.0 V vs. for V3+/V4+ in Na3V2(PO4)2F3) could allow the achievement the 1 kWh/kg milestone at the positive electrode level in Alkali-ion batteries. However, a massive divergence in the voltage reported for the V3+/V4+ and V4+/V5+ redox couples as a function of crystal structure is noticed. Moreover, vanadium phosphates that operate at high V3+/V4+ voltages are usually unable to reversibly exchange several electrons in a narrow enough voltage range. Here, through the review of redox mechanisms and structural evolutions upon electrochemical operation of selected widely studied materials, we identify the crystallographic origin of this trend: the distribution of PO4 groups around vanadium octahedra, that allows or prevents the formation of the vanadyl distortion (O…V4+=O or O…V5+=O). While the vanadyl entity massively lowers the voltage of the V3+/V4+ and V4+/V5+ couples, it considerably improves the reversibility of these redox reactions. Therefore, anionic substitutions, mainly O2− by F−, have been identified as a strategy allowing for combining the beneficial effect of the vanadyl distortion on the reversibility with the high voltage of vanadium redox couples in fluorine rich environments.
Benzenetriol-Derived Compounds against Citrus Canker
Authors: Cavalca Lúcia Bonci , Lahive Ciaran W. , Gijsbers Fleur , Pavan Fernando Rogério , Scheffers Dirk-Jan , Deuss Peter J.
Published: March 2021

In order to replace the huge amounts of copper salts used in citrus orchards, alternatives have been sought in the form of organic compounds of natural origin with activity against the causative agent of citrus canker, the phytopathogen Xanthomonas citri subsp. Citri. We synthesized a series of 4-alkoxy-1,2-benzene diols (alkyl-BDOs) using 1,2,4-benzenetriol (BTO) as a starting material through a three-step synthesis route and evaluated their suitability as antibacterial compounds. Our results show that alkyl ethers derived from 1,2,4-benzenetriol have bactericidal activity against X. citri, disrupting the bacterial cell membrane within 15 min. Alkyl-BDOs were also shown to remain active against the bacteria while in solution, and presented low toxicity to (human) MRC-5 cells. Therefore, we have demonstrated that 1,2,4-benzenetriol—a molecule that can be obtained from agricultural residues—is an adequate precursor for the synthesis of new compounds with activity against X. citri.
Extract from the Marine Seaweed Padina pavonica Protects Mitochondrial Biomembranes from Damage by Amyloidogenic Peptides
Authors: Caruana Mario , Camilleri Angelique , Farrugia Maria Ylenia , Ghio Stephanie , Jakubíčková Michaela , Cauchi Ruben J. , Vassallo Neville
Published: March 2021

The identification of compounds which protect the double-membrane of mitochondrial organelles from disruption by toxic confomers of amyloid proteins may offer a therapeutic strategy to combat human neurodegenerative diseases. Here, we exploited an extract from the marine brown seaweed Padina pavonica (PPE) as a vital source of natural bioactive compounds to protect mitochondrial membranes against insult by oligomeric aggregates of the amyloidogenic proteins amyloid-β (Aβ), α-synuclein (α-syn) and tau, which are currently considered to be major targets for drug discovery in Alzheimer’s disease (AD) and Parkinson’s disease (PD). We show that PPE manifested a significant inhibitory effect against swelling of isolated mitochondria exposed to the amyloid oligomers, and attenuated the release of cytochrome c from the mitochondria. Using cardiolipin-enriched synthetic lipid membranes, we also show that dye leakage from fluorophore-loaded vesicles and formation of channel-like pores in planar bilayer membranes are largely prevented by incubating the oligomeric aggregates with PPE. Lastly, we demonstrate that PPE curtails the ability of Aβ42 and α-syn monomers to self-assemble into larger β-aggregate structures, as well as potently disrupts their respective amyloid fibrils. In conclusion, the mito-protective and anti-aggregator biological activities of Padina pavonica extract may be of therapeutic value in neurodegenerative proteinopathies, such as AD and PD.
Structure-Based Virtual Screening Identifies Multiple Stable Binding Sites at the RecA Domains of SARS-CoV-2 Helicase Enzyme
Authors: Ahmad Sajjad , Waheed Yasir , Ismail Saba , Bhatti Saadia , Abbasi Sumra Wajid , Muhammad Khalid
Published: March 2021

With the emergence and global spread of the COVID-19 pandemic, the scientific community worldwide has focused on search for new therapeutic strategies against this disease. One such critical approach is targeting proteins such as helicases that regulate most of the SARS-CoV-2 RNA metabolism. The purpose of the current study was to predict a library of phytochemicals derived from diverse plant families with high binding affinity to SARS-CoV-2 helicase (Nsp13) enzyme. High throughput virtual screening of the Medicinal Plant Database for Drug Design (MPD3) database was performed on SARS-CoV-2 helicase using AutoDock Vina. Nilotinib, with a docking value of −9.6 kcal/mol, was chosen as a reference molecule. A compound (PubChem CID: 110143421, ZINC database ID: ZINC257223845, eMolecules: 43290531) was screened as the best binder (binding energy of −10.2 kcal/mol on average) to the enzyme by using repeated docking runs in the screening process. On inspection, the compound was disclosed to show different binding sites of the triangular pockets collectively formed by Rec1A, Rec2A, and 1B domains and a stalk domain at the base. The molecule is often bound to the ATP binding site (referred to as binding site 2) of the helicase enzyme. The compound was further discovered to fulfill drug-likeness and lead-likeness criteria, have good physicochemical and pharmacokinetics properties, and to be non-toxic. Molecular dynamic simulation analysis of the control/lead compound complexes demonstrated the formation of stable complexes with good intermolecular binding affinity. Lastly, affirmation of the docking simulation studies was accomplished by estimating the binding free energy by MMPB/GBSA technique. Taken together, these findings present further in silco investigation of plant-derived lead compounds to effectively address COVID-19.
Quali–Quantitative Characterization of Volatile and Non-Volatile Compounds in Protium heptaphyllum (Aubl.) Marchand Resin by GC–MS Validated Method, GC–FID and HPLC–HRMS2
Authors: Asteggiano Alberto , Occhipinti Andrea , Capuzzo Andrea , Mecarelli Enrica , Aigotti Riccardo , Medana Claudio
Published: March 2021

Protium heptaphyllum (Aubl.) Marchand (PH) trees are endemic to the tropical region of South America, mostly Brazil. Antibacterial, antinociceptive, anti-inflammatory, anxiolytic, antidepressant and anti-hyperlipidemic/anti-hypercholesterolemic effects were reported for its resinous exudate Protiumheptaphyllum resin (PHR). This work aims to provide a qualitative and quantitative consistent chemical profiling of the major constituents of this resin and two extracts enriched in acid (acidic triterpene concentrated extract, ATCE) and neutral triterpenes (α and β-amyrin concentrated extract, AMCE). GC–MS/GC–FID was used for volatile terpene fraction, a validated GC–MS method was developed for quantification of neutral α and β-amyrin and HPLC–APCI HRMS2 was used for acidic triterpenes analysis. The chemical investigation reported 29 molecules, including 14 volatile terpenes, 6 neutral triterpenes and 11 acid triterpenes. The most abundant compounds were α-amyrin (251.28 g kg−1, 123.98 g kg−1 and 556.82 g kg−1 in PHR, ATCE and AMCE, respectively), β-amyrin (172.66 g kg−1, 95.39 g kg−1 and 385.58 g kg−1 in PHR, ATCE and AMCE, respectively), 3-oxo-tirucalla-7,24-dien-21-oic acid (80.64 g kg−1, 157.10 g kg−1 and 15.31 g kg−1 in PHR, ATCE and AMCE, respectively) and 3α-hydroxy-tirucalla-8,24-dien-21-oic acid (77.71 g kg−1, 130.40 g kg−1 and 11.64 g kg−1 in PHR, ATCE and AMCE, respectively). Results showed specific enrichment of acidic and neutral triterpenoids in the two respective extracts.
Chemical Composition, Antioxidant, Antimicrobial, and Phytotoxic Potential of Eucalyptus grandis × E. urophylla Leaves Essential Oils
Authors: Zhou Lijun , Li Jiajia , Kong Qingbo , Luo Siyuan , Wang Jie , Feng Shiling , Yuan Ming , Chen Tao , Yuan Shu , Ding Chunbang
Published: March 2021

Eucalyptus grandis × E. urophylla was a unique hybridization in China. However, the chemical and pharmacological properties were rarely reported. Therefore, in this work, we used a steam distillation method to obtain essential oils from leaves of E. grandis × E. urophylla, and further evaluated the antioxidant, antimicrobial, and phytotoxic potential of the essential oil. Gas chromatography mass spectrometry (GC-MS) was applied to investigate the chemical composition of E. grandis × E. urophylla essential oil (EEO) and the results showed that the main components of EEO were monoterpenes followed by sesquiterpenes. Among them, α-pinene accounted about 17.02%. EEO could also well scavenge 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2, 2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) free radicals showing a good free radical clearance ability. In addition, EEO efficiently inhibited the growth of six kinds of bacteria as well as seven kinds of plant pathogens, especially Salmonella typhimurium and Colletotrichum gloeosporioides. Moreover, the seedling germination of Raphanus sativus, Lactuca sativa, Lolium perenne, and Bidens pilosa was significantly suppressed by EEO, thus, indicating essential oils from eucalyptus possessed an excellent phytotoxic activity. This study may give a better understanding on EEO and provide a pharmacological activities analysis contributing to the further research of EEO as a functional drug in agronomic and cosmetic industries.
Water Extract of Mungbean (Vigna radiata L.) Inhibits Protein Tyrosine Phosphatase-1B in Insulin-Resistant HepG2 Cells
Authors: Saeting Orathai , Chandarajoti Kasemsiri , Phongphisutthinan Angsuma , Hongsprabhas Parichat , Sae-tan Sudathip
Published: March 2021

The present study aimed to investigate the effects of mungbean water extract (MWE) on insulin downstream signaling in insulin-resistant HepG2 cells. Whole seed mungbean was extracted using boiling water, mimicking a traditional cooking method. Vitexin and isovitexin were identified in MWE. The results showed that MWE inhibited protein tyrosine phosphatase (PTP)-1B (IC50 = 10 μg/mL), a negative regulator of insulin signaling. MWE enhanced cellular glucose uptake and altered expression of genes involved in glucose metabolism, including forkhead box O1 (FOXO1), phosphoenolpyruvate carboxykinase (PEPCK), and glycogen synthase kinase (GSK)-3β in the insulin-resistant HepG2 cells. In addition, MWE inhibited both α-amylase (IC50 = 36.65 mg/mL) and α-glucosidase (IC50 = 3.07 mg/mL). MWE also inhibited the formation of advanced glycation end products (AGEs) (IC50 = 2.28 mg/mL). This is the first study to show that mungbean water extract increased cellular glucose uptake and improved insulin sensitivity of insulin-resistant HepG2 cells through PTP-1B inhibition and modulating the expression of genes related to glucose metabolism. This suggests that mungbean water extract has the potential to be a functional ingredient for diabetes.
Plasma Synthesis of Advanced Metal Oxide Nanoparticles and Their Applications as Transparent Conducting Oxide Thin Films
Authors: Sohn Hong Yong , Murali Arun
Published: March 2021

This article reviews and summarizes work recently performed in this laboratory on the synthesis of advanced transparent conducting oxide nanopowders by the use of plasma. The nanopowders thus synthesized include indium tin oxide (ITO), zinc oxide (ZnO) and tin-doped zinc oxide (TZO), aluminum-doped zinc oxide (AZO), and indium-doped zinc oxide (IZO). These oxides have excellent transparent conducting properties, among other useful characteristics. ZnO and TZO also has photocatalytic properties. The synthesis of these materials started with the selection of the suitable precursors, which were injected into a non-transferred thermal plasma and vaporized followed by vapor-phase reactions to form nanosized oxide particles. The products were analyzed by the use of various advanced instrumental analysis techniques, and their useful properties were tested by different appropriate methods. The thermal plasma process showed a considerable potential as an efficient technique for synthesizing oxide nanopowders. This process is also suitable for large scale production of nano-sized powders owing to the availability of high temperatures for volatilizing reactants rapidly, followed by vapor phase reactions and rapid quenching to yield nano-sized powder.
Bioguided Fractionation of Local Plants against Matrix Metalloproteinase9 and Its Cytotoxicity against Breast Cancer Cell Models: In Silico and In Vitro Study (Part II)
Authors: Hariono Maywan , Rollando Rollando , Yoga I , Harjono Abraham , Suryodanindro Alfonsus , Yanuar Michael , Gonzaga Thomas , Parabang Zet , Hariyono Pandu , Febriansah Rifki , Hermawansyah Adi , Setyani Wahyuning , Wahab Habibah
Published: March 2021

In our previous work, the partitions (1 mg/mL) of Ageratum conyzoides (AC) aerial parts and Ixora coccinea (IC) leaves showed inhibitions of 94% and 96%, respectively, whereas their fractions showed IC50 43 and 116 µg/mL, respectively, toward Matrix Metalloproteinase9 (MMP9), an enzyme that catalyzes a proteolysis of extracellular matrix. In this present study, we performed IC50 determinations for AC n-hexane, IC n-hexane, and IC ethylacetate partitions, followed by the cytotoxicity study of individual partitions against MDA-MB-231, 4T1, T47D, MCF7, and Vero cell lines. Successive fractionations from AC n-hexane and IC ethylacetate partitions led to the isolation of two compounds, oxytetracycline (OTC) and dioctyl phthalate (DOP). The result showed that AC n-hexane, IC n-hexane, and IC ethylacetate partitions inhibit MMP9 with their respective IC50 as follows: 246.1 µg/mL, 5.66 µg/mL, and 2.75 × 10−2 µg/mL. Toward MDA-MB-231, 4T1, T47D, and MCF7, AC n-hexane demonstrated IC50 2.05, 265, 109.70, and 2.11 µg/mL, respectively, whereas IC ethylacetate showed IC50 1.92, 57.5, 371.5, and 2.01 µg/mL, respectively. The inhibitions toward MMP9 by OTC were indicated by its IC50 18.69 µM, whereas DOP was inactive. A molecular docking study suggested that OTC prefers to bind to PEX9 rather than its catalytic domain. Against 4T1, OTC showed inhibition with IC50 414.20 µM. In conclusion, this study furtherly supports the previous finding that AC and IC are two herbals with potential to be developed as triple-negative anti-breast cancer agents.
Effect-Directed Profiling of 17 Different Fortified Plant Extracts by High-Performance Thin-Layer Chromatography Combined with Six Planar Assays and High-Resolution Mass Spectrometry
Authors: Morlock Gertrud E. , Heil Julia , Bardot Valérie , Lenoir Loïc , Cotte César , Dubourdeaux Michel
Published: March 2021

An effect-directed profiling method was developed to investigate 17 different fortified plant extracts for potential benefits. Six planar effect-directed assays were piezoelectrically sprayed on the samples separated side-by-side by high-performance thin-layer chromatography. Multipotent compounds with antibacterial, α-glucosidase, β-glucosidase, AChE, tyrosinase and/or β-glucuronidase-inhibiting effects were detected in most fortified plant extracts. A comparatively high level of antimicrobial activity was observed for Eleutherococcus, hops, grape pomace, passiflora, rosemary and Eschscholzia. Except in red vine, black radish and horse tail, strong enzyme inhibiting compounds were also detected. Most plants with anti-α-glucosidase activity also inhibited β-glucosidase. Green tea, lemon balm and rosemary were identified as multipotent plants. Their multipotent compound zones were characterized by high-resolution mass spectrometry to be catechins, rosmarinic acid, chlorogenic acid and gallic acid. The results pointed to antibacterial and enzymatic effects that were not yet known for plants such as Eleutherococcus and for compounds such as cynaratriol and caffeine. The nontarget effect-directed profiling with multi-imaging is of high benefit for routine inspections, as it provides comprehensive information on the quality and safety of the plant extracts with respect to the global production chain. In this study, it not only confirmed what was expected, but also identified multipotent plants and compounds, and revealed new bioactivity effects.
Simplified Approach for Preparing Graphene Oxide TEM Grids for Stained and Vitrified Biomolecules
Authors: Kumar Anil , Sengupta Nayanika , Dutta Somnath
Published: March 2021

In this manuscript, we report the application of graphene oxide (GO) in the preparation of cryo-electron microscopy (cryo-EM) and transmission electron microscopy (TEM) grids. We treated GO with water and organic solvents, such as, methanol, ethanol and isopropanol separately to isolate significantly large GO monolayer flake to fabricate the grids for cryo-EM and TEM study. We implemented a simplified approach to isolate flakes of GO monolayer for constructing the TEM grids, independent of expensive heavy equipment (Langmuir–Blodgett trough, glow-discharge system, carbon-evaporator or plasma-cleaner or peristaltic pumps). We employed confocal microscopy, SEM and TEM to characterize the flake size, stability and transparency of the GO monolayer and atomic force microscopy (AFM) to probe the depth of GO coated grids. Additionally, GO grids are visualized at cryogenic condition for suitability of GO monolayer for cryo-EM study. In addition, GO-Met-H2O grids reduce the effect of preferred orientation of biological macromolecules within the amorphous ice. The power-spectrum and contrast-transfer-function unequivocally suggest that GO-Met-H2O fabricated holey grids have excellent potential for application in high-resolution structural characterization of biomolecules. Furthermore, only 200 movies and ~8000 70S ribosome particles are selected on GO-coated grids for cryo-EM reconstruction to achieve high-resolution structure.
Raman and Fluorescence Enhancement Approaches in Graphene-Based Platforms for Optical Sensing and Imaging
Authors: Cortijo-Campos Sandra , Ramírez-Jiménez Rafael , de Andrés Alicia
Published: March 2021

The search for novel platforms and metamaterials for the enhancement of optical and particularly Raman signals is still an objective since optical techniques offer affordable, noninvasive methods with high spatial resolution and penetration depth adequate to detect and image a large variety of systems, from 2D materials to molecules in complex media and tissues. Definitely, plasmonic materials produce the most efficient enhancement through the surface-enhanced Raman scattering (SERS) process, allowing single-molecule detection, and are the most studied ones. Here we focus on less explored aspects of SERS such as the role of the inter-nanoparticle (NP) distance and the ultra-small NP size limit (down to a few nm) and on novel approaches involving graphene and graphene-related materials. The issues on reproducibility and homogeneity for the quantification of the probe molecules will also be discussed. Other light enhancement mechanisms, in particular resonant and interference Raman scatterings, as well as the platforms that allow combining several of them, are presented in this review with a special focus on the possibilities that graphene offers for the design and fabrication of novel architectures. Recent fluorescence enhancement platforms and strategies, so important for bio-detection and imaging, are reviewed as well as the relevance of graphene oxide and graphene/carbon nanodots in the field.
Thermal Conductivity Analysis of Chitin and Deacetylated-Chitin Nanofiber Films under Dry Conditions
Authors: Wang Jiahao , Kasuya Keitaro , Koga Hirotaka , Nogi Masaya , Uetani Kojiro
Published: March 2021

Chitin, a natural polysaccharide polymer, forms highly crystalline nanofibers and is expected to have sophisticated engineering applications. In particular, for development of next-generation heat-transfer and heat-insulating materials, analysis of the thermal conductivity is important, but the thermal conductivity properties of chitin nanofiber materials have not been reported. The thermal conductivity properties of chitin nanofiber materials are difficult to elucidate without excluding the effect of adsorbed water and analyzing the influence of surface amino groups. In this study, we aimed to accurately evaluate the thermal conductivity properties of chitin nanofiber films by changing the content of surface amino groups and measuring the thermal diffusivity under dry conditions. Chitin and deacetylated-chitin nanofiber films with surface deacetylation of 5.8% and 25.1% showed in-plane thermal conductivity of 0.82 and 0.73 W/mK, respectively. Taking into account that the films had similar crystalline structures and almost the same moisture contents, the difference in the thermal conductivity was concluded to only depend on the amino group content on the fiber surfaces. Our methodology for measuring the thermal diffusivity under conditioned humidity will pave the way for more accurate analysis of the thermal conductivity performance of hydrophilic materials.
The Role of the Surface Acid–Base Nature of Nanocrystalline Hydroxyapatite Catalysts in the 1,6-Hexanediol Conversion
Authors: Nakagiri Asato , Imamura Kazuya , Yanagisawa Kazumichi , Onda Ayumu
Published: March 2021

Hydroxyapatite is known to have excellent catalytic properties for ethanol conversion and lactic acid conversion, and their properties are influenced by the elemental composition, such as Ca/P ratio and sodium content. However, few reports have been examined for the surface acid–base nature of hydroxyapatites containing sodium ions. We prepared nanocrystalline hydroxyapatite (Ca-HAP) catalysts with various Ca/P ratios and sodium contents by the hydrothermal method. The adsorption and desorption experiments using NH3 and CO2 molecules and the catalytic reactions for 2-propenol conversion revealed that the surface acid–base natures changed continuously with the bulk Ca/P ratios. Furthermore, the new catalytic properties of hydroxyapatite were exhibited for 1,6-hexanediol conversion. The non-stoichiometric Ca-HAP(1.54) catalyst with sodium ions of 2.3 wt% and a Ca/P molar ratio of 1.54 gave a high 5-hexen-1-ol yield of 68%. In contrast, the Ca-HAP(1.72) catalyst, with a Ca/P molar ratio of 1.72, gave a high cyclopentanemethanol yield of 42%. Both yields were the highest ever reported in the relevant literature. It was shown that hydroxyapatite also has excellent catalytic properties for alkanediol conversion because the surface acid–base properties can be continuously controlled by the elemental compositions, such as bulk Ca/P ratios and sodium contents.
Cognitive Function in Adults with Enduring Anorexia Nervosa
Authors: Seidel Maria , Brooker Helen , Lauenborg Kamilla , Wesnes Keith , Sjögren Magnus
Published: March 2021

Anorexia Nervosa (AN) is a severe and often enduring disorder characterized by restriction of food intake, low body weight, fear of weight gain, and distorted body image. Investigations on cognition performance in AN patients have yielded conflicting results. Using an established and sensitive computerized cognitive test battery, we aimed to assess core aspects of cognitive function, including attention span, information processing, reasoning, working and episodic memory, in AN patients and controls. Patients were recruited from the Danish Prospective Longitudinal all-comer inclusion study in Eating Disorders (PROLED). Included were 26 individuals with AN and 36 healthy volunteers (HV). All were tested with CogTrack (an online cognitive assessment system) at baseline, and AN patients were tested again at a follow-up time point after weight increase (n = 13). At baseline, AN patients showed faster reaction times in the attention tasks, as well as increased accuracy in grammatical reasoning compared to HV. There were no differences in cognitive function between AN patients and HV in the other cognitive domains measured (sustained attention, working and episodic memory, speed of retrieval, and speed of grammatical reasoning). No differences were visible in the AN sample between baseline and follow-up. Performance did not correlate with any clinical variables in the AN sample. These findings supplement results from other studies suggesting increased concentration and reasoning accuracy in patients suffering from AN, who showed increased performance in cognitive tasks despite their illness.
Effect of Maternal Nutritional Status and Mode of Delivery on Zinc and Iron Stores at Birth
Authors: Dumrongwongsiri Oraporn , Winichagoon Pattanee , Chongviriyaphan Nalinee , Suthutvoravut Umaporn , Grote Veit , Koletzko Berthold
Published: March 2021

Zinc and iron deficiencies among infants aged under 6 months may be related with nutrient store at birth. This study aimed to investigate the association between zinc and iron stores at birth with maternal nutritional status and intakes during pregnancy. 117 pregnant women were enrolled at the end of second trimester and followed until delivery. Clinical data during pregnancy, including pre-pregnancy body mass index (BMI) and at parturition were collected from medical record. Zinc and iron intakes were estimated from a food frequency questionnaire. Serum zinc and ferritin were determined in maternal blood at enrollment and cord blood. Mean cord blood zinc and ferritin were 10.8 ± 2.6 µmol/L and 176 ± 75.6 µg/L, respectively. Cord blood zinc was associated with pre-pregnancy BMI (adj. ß 0.150; p = 0.023) and serum zinc (adj. ß 0.115; p = 0.023). Cord blood ferritin was associated with pre-pregnancy BMI (adj. ß −5.231; p = 0.009). Cord blood zinc and ferritin were significantly higher among those having vaginal delivery compared to cesarean delivery (adj. ß 1.376; p = 0.007 and 32.959; p = 0.028, respectively). Maternal nutritional status and mode of delivery were significantly associated with zinc and iron stores at birth. Nutrition during preconception and pregnancy should be ensured to build adequate stores of nutrients for infants.