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The speciation of arsenic in fish has been widely investigated, but bioaccumulation and biotransformation of inorganic As in different tissues of Nile tilapia (Oreochromis niloticus) are not fully understood. The present study aimed to investigate the bioaccumulation of As in Nile tilapia, as well as to evaluate the distribution of the main arsenic species (As(III), As(V), MMA, DMA, and AsB) in liver, stomach, gill, and muscle, after controlled exposures to As(III) and As(V) at concentrations of 5.0 and 10.0 mg L -1 during periods of 1 and 7 days. Total As was determined by inductively coupled plasma mass spectroscopy (ICP-MS). For both exposures (As(III) and As(V)), the total As levels after 7-day exposure were highest in the liver and lowest in the muscle. Overall, the Nile tilapia exposed to As(III) showed higher tissue levels of As after the treatments, compared to As(V) exposure. Speciation of arsenic present in the tissues employed liquid chromatography coupled to ICP-MS (LC-ICP-MS), revealing that the biotransformation of As included As(V) reduction to As(III), methylation to monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA), and subsequent conversion to nontoxic arsenobetaine (AsB), which was the predominant arsenic form. Finally, the interactions and antagonistic effects of selenium in the bioaccumulation processes were tested by the combined exposure to As(III), the most toxic species of As, together with tetravalent selenium (Se(IV)). The results indicated a 4-6 times reduction of arsenic toxicity in the tilapia., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

This review analyzes the current progress in loaded nanoparticles (NPs) of plant extracts or isolated antineoplastic compounds used in breast and cervical cancer treatments. Also, it provides a comprehensive overview of the contributions made by traditional medicine and nanomedicine to the research of two of the most prevalent types of cancer in women worldwide: breast and cervical cancer. Searches were conducted in electronic databases to gather relevant information related to the biological activity of the NPs, which were meticulously reviewed. Nanomedicine has advanced to incorporate plant compounds including their crude extracts, in the preparation of NPs. The most used method is green synthesis, whose most outstanding advantages, is the reduced preparation time, and the variety of results that can be obtained depending on the reaction times, pH, temperature, and concentration of both the bio-reducing agent and the compound or plant extract. Most of the studies focus on evaluating crude extracts with high polarity, such as aqueous, alcoholic, and hydroalcoholic extracts. In conclusion, exploring the use of organic compounds is considered an area of opportunity for further research and future perspectives. Most of the analyzed studies were conducted using in vitro assays, highlighting the relatively recent nature of this field. It is expected that future research will involve more in vivo assays, particularly focusing on isolated cell lines representing the most difficult-to-treat types of cancer, such as triple-negative breast cancer like MDA-MB-231. Notably the MCF-7 cell line is one of the most used, while limited studies were found concerning cervical cancer., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The red blood cells (RBCs) are essential to transport oxygen (O 2 ) and nutrients throughout the human body. Changes in the structure or functioning of the erythrocytes can lead to several deficiencies, such as hemolytic anemias, in which an increase in reactive oxidative species generation is involved in the pathophysiological process, playing a significant role in the severity of several clinical manifestations. There are important lines of defense against the damage caused by oxidizing molecules. Among the antioxidant molecules, the enzyme peroxiredoxin (Prx) has the higher decomposition power of hydrogen peroxide, especially in RBCs, standing out because of its abundance. This review aimed to present the recent findings that broke some paradigms regarding the three isoforms of Prxs found in RBC (Prx1, Prx2, and Prx6), showing that in addition to their antioxidant activity, these enzymes may have supplementary roles in transducing peroxide signals, as molecular chaperones, protecting from membrane damage, and maintenance of iron homeostasis, thus contributing to the overall survival of human RBCs, roles that seen to be disrupted in hemolytic anemia conditions., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: Interactions between the somatosensory and motor cortices are of fundamental importance for motor control. Although physically distant, face and hand representations are side by side in the sensorimotor cortex and interact functionally. Traumatic brachial plexus injury (TBPI) interferes with upper limb sensorimotor function, causes bilateral cortical reorganization, and is associated with chronic pain. Thus, TBPI may affect sensorimotor interactions between face and hand representations., Objective: The aim of this study was to investigate changes in hand-hand and face-hand sensorimotor integration in TBPI patients using an afferent inhibition (AI) paradigm., Method: The experimental design consisted of electrical stimulation (ES) applied to the hand or face followed by transcranial magnetic stimulation (TMS) to the primary motor cortex to activate a hand muscle representation. In the AI paradigm, the motor evoked potential (MEP) in a target muscle is significantly reduced when preceded by an ES at short-latency (SAI) or long-latency (LAI) interstimulus intervals. We tested 18 healthy adults (control group, CG), evaluated on the dominant upper limb, and nine TBPI patients, evaluated on the injured or the uninjured limb. A detailed clinical evaluation complemented the physiological investigation., Results: Although hand-hand SAI was present in both the CG and the TBPI groups, hand-hand LAI was present in the CG only. Moreover, less AI was observed in TBPI patients than the CG both for face-hand SAI and LAI., Conclusion: Our results indicate that sensorimotor integration involving both hand and face sensorimotor representations is affected by TBPI., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Torres, Ramalho, Rodrigues, Schmaedeke, Moraes, Reilly, Carvalho and Vargas.)

Green synthesis of metallic nanoparticles using microalgae exposed to high CO 2 atmospheres has not been studied in detail; this is of relevance in biological CO 2 mitigation systems where considerable biomass is produced. In this study, we further characterized the potential of an environmental isolate Desmodesmus abundans acclimated to low and high CO 2 atmospheres [low carbon acclimation (LCA) and high carbon acclimation (HCA) strains, respectively] as a platform for silver nanoparticle (AgNP) synthesis. As previously characterized, cell pellets at pH 11 were selected from the biological components tested of the different microalgae, which included the culture collection strain Spirulina platensis . AgNP characterization showed superior performance of strain HCA components as preserving the supernatant resulted in synthesis in all pH conditions. Size distribution analysis evidenced strain HCA cell pellet platform (pH 11) as the most homogeneous AgNP population (14.9 ± 6.4 nm diameter, -32.7 ± 5.3 mV) followed by S. platensis (18.3 ± 7.5 nm, -33.9 ± 2.4 mV). In contrast, strain LCA presented a broader population where the size was above 100 nm (127.8 ± 14.8 nm, -26.7 ± 2.4 mV). Fourier-transform infrared and Raman spectroscopies showed that the reducing power of microalgae might be attributed to functional groups in the cell pellet from proteins, carbohydrates, and fatty acids and, in the supernatant, from amino acids, monosaccharides, disaccharides, and polysaccharides. Microalgae AgNPs exhibited similar antimicrobial properties in the agar diffusion test against Escherichia coli . However, they were not effective against Gram (+) Lactobacillus plantarum . It is suggested that a high CO 2 atmosphere potentiates components in the D. abundans strain HCA for nanotechnology applications., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)

The widespread use of titanium dioxide (TiO 2 ) has raised concerns about potential health risks associated with its cytotoxicity in the cardiovascular system. To evaluate the cytotoxicity of TiO 2 particles, the H9c2 rat cardiomyoblasts were used as a biological model, and their toxicological susceptibility to TiO 2 -anatase and TiO 2 -rutile particles was studied in vitro. The study examined dose and time exposure responses. The cell viability was evaluated based on metabolic inhibition and membrane integrity loss. The results revealed that both TiO 2 -anatase and TiO 2 -rutile particles induced similar levels of cytotoxicity at the inhibition concentrations IC 25 (1.4-4.4 μg/cm 2 ) and IC 50 (7.2-9.3 μg/cm 2 ). However, at more significant concentrations, TiO 2 -rutile appeared to be more cytotoxic than TiO 2 -anatase at 24 h. The study found that the TiO 2 particles induced apoptosis events, but necrosis was not observed at any of the concentrations of particles used. The study considered the effects of microstructural properties, crystalline phase, and particle size in determining the capability of TiO 2 particles to induce cytotoxicity in H9c2 cardiomyoblasts. The microstress in TiO 2 particles was assessed using powder X-ray diffraction through Williamson-Hall and Warren-Averbach analysis. The analysis estimated the apparent crystallite domain and microstrain of TiO 2 -anatase to be 29 nm (ε = 1.03%) and TiO 2 -rutile to be 21 nm (ε = 0.53%), respectively. Raman spectroscopy, N 2 adsorption isotherms, and dynamic light scattering were used to identify the presence of pure crystalline phases (>99.9%), comparative surface areas (10 m 2 /g), and ζ-potential values (-24 mV). The difference in the properties of TiO 2 particles made it difficult to attribute the cytotoxicity solely to one variable., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)

Oxidative stress is a major cause of morbidity and mortality in human health and disease. In this review, we focus on the Forkhead Box (Fox) subclass O3 (FoxO3), an extensively studied transcription factor that plays a pleiotropic role in a wide range of physiological and pathological processes by regulating multiple gene regulatory networks involved in the modulation of numerous aspects of cellular metabolism, including fuel metabolism, cell death, and stress resistance. This review will also focus on regulatory mechanisms of FoxO3 expression and activity, such as crucial post-translational modifications and non-coding RNAs. Moreover, this work discusses and evidences some pathways to how this transcription factor and reactive oxygen species regulate each other, which may lead to the pathogenesis of various types of diseases. Therefore, in addition to being a promising therapeutic target, the FoxO3-regulated signaling pathways can also be used as reliable diagnostic and prognostic biomarkers and indicators for drug responsiveness., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

This study aimed to establish the importance of ergothioneine (ERT) in the erythroid adaptation mechanisms by appraising the expression levels of redox-related genes associated with the PI3K/AKT/FoxO3 and Nrf2-ARE pathways using K562 cells induced to erythroid differentiation and H 2 O 2 -oxidative stress. Cell viability and gene expression were evaluated. Two concentrations of ERT were assessed, 1 nM (C1) and 100 µM (C2), with and without stress induction (100 µM H 2 O 2 ). Assessments were made in three periods of the cellular differentiation process (D0, D2, and D4). The C1 treatment promoted the induction of FOXO3 (D0 and 2), PSMB5 , and 6 expressions (D4); C1 + H 2 O 2 treatment showed the highest levels of NRF2 transcripts, KEAP1 (D0), YWHAQ (D2 and 4), PSMB5 (D2) and PSMB6 (D4); and C2 + H 2 O 2 (D2) an increase in FOXO3 and MST1 expression, with a decrease of YWHAQ and NRF2 was observed. in C2 + H 2 O 2 (D2) an increase in FOXO3 and MST1 , with a decrease in YWHAQ and NRF2 was observed All ERT treatments increased gamma-globin expression. Statistical multivariate analyzes highlighted that the Nrf2-ARE pathway presented a greater contribution in the production of PRDX1 , SOD1 , CAT , and PSBM5 mRNAs, whereas the PI3K/AKT/FoxO3 pathway was associated with the PRDX2 and TRX transcripts. In conclusion, ERT presented a cytoprotective action through Nrf2 and FoxO3, with the latter seeming to contribute to erythroid proliferation/differentiation.

Melatonin (MEL) presents well-documented pleiotropic actions against oxidative stress (OS), acting indirectly through activation of transcription factors, e.g., FoxO3 and Nrf2. Thus, this study aimed to investigate the possible modulating effects of MEL on the redox signaling pathways PI3K/AKT/FoxO3 and Keap1/Nrf2/ARE in K562 erythroleukemic cells subjected to OS induction. For this, the viability, and transcript levels of genes involved in redox adaptation were evaluated in K562 cells in different periods of erythroid differentiation: under OS induction by hydrogen peroxide (100 µM H 2 O 2 ); treated with 1 nM (C1) and 1 mM (C2) MEL; and associated or not with stress induction. We observed a restoration of physiological levels of Nrf2 in both MEL concentrations under OS. The C1 was related to enhanced expression of antioxidant and proteasome genes through the Nrf2-ARE pathway, while C2 to the induction of FOXO3 expression, suggesting an involvement with apoptotic pathway, according to BIM transcript levels. The effects of MEL administration in these cells showed a period and dose-dependent pattern against induced-OS, with direct and indirect actions through different pathways of cellular adaptation, reinforcing the importance of this indolamine in the regulation of cellular homeostasis, being a promising therapeutic alternative for diseases that present an exacerbated OS.

Scanning tunneling microscopy (STM) is a technique that can be used to directly observe individual biomolecules at near-molecular scale. Within this framework, STM is of crucial significance because of its role in the structural analysis, the understanding the imaging formation, and the development of relative techniques. Four decades after its invention, it is pertinent to ask how much of the early dream has come true. In this study, we aim to overview different analyses for DNA, lipids, proteins, and carbohydrates. The relevance of STM imaging is exhibited as an opportunity to assist measurements and biomolecular identification in nanobiotechnology, nanomedicine, biosensing, and other cutting-edge applications. We believe STM research is still an entire science research ecosystem for joining several areas of expertise towards a goal settlement that has been elusive for many years.

Photosensitive supramolecular systems have garnered attention due to their potential to catalyze highly specific tasks through structural changes triggered by a light stimulus. The tunability of their chemical structure and charge transfer properties provides opportunities for designing and developing smart materials for multidisciplinary applications. This review focuses on the approaches reported in the literature for tailoring properties of the photosensitive supramolecular systems, including MOFs, MOPs, and HOFs. We discuss relevant aspects regarding their chemical structure, action mechanisms, design principles, applications, and future perspectives.

Introduction: Studies have shown that the loss of the FOXO3 transcriptional function is involved in the pathophysiology of some chronic erythroid disorders, including beta-thalassemia (β-thal). Therefore, the single nucleotide polymorphism (SNP) rs3800231 (35-2764A > G) could contribute to alterations in its transcriptional activity, acting as a modifier of β-thal phenotypic manifestations., Objective and Method: In order to better understand the genotypic and/or allelic distributions among β-thal patients, we evaluated 83 β-thal heterozygous and 20 homozygous, compared to 117 individuals without hemoglobinopathies (control group). Additionally, we verified any influence of the FOXO3 polymorphism on clinical manifestations among β-thal homozygotes., Results: We obtained higher frequencies of the wild-type homozygous (AA) and the wild-type allele (A) in the β-thal group (p < 0.0001 and p = 0.00014, respectively). The most common clinical manifestations found among β-thal homozygotes were iron overload (90%), splenomegaly (65%) and bone complications (35%), e.g., osteopenia/osteoporosis. We observed that close to 80% of the patients presenting such manifestations had the genotype AA. However, we did not find any significant involvement of the FOXO3 polymorphism in clinical manifestation occurrences., Conclusion: Thus, we concluded that the SNP rs3800231 did not play a significant role as a modifier of the clinical manifestations observed in the β-thal homozygotes studied., (Copyright © 2020 Associação Brasileira de Hematologia, Hemoterapia e Terapia Celular. Published by Elsevier España, S.L.U. All rights reserved.)

Objectives: This study evaluated 2 nickel-titanium rotary systems and a complementary protocol with an ultrasonic tip and a small-diameter instrument in flattened root canals., Materials and Methods: Thirty-two human maxillary second premolars with flattened canals (buccolingual diameter ≥4 times larger than the mesiodistal diameter) at 9 mm from the radiographic apex were selected. The root canals were prepared by ProDesign Logic (PDL) 30/0.01 and 30/0.05 or Hyflex EDM (HEDM) 10/0.05 and 25/0.08 ( n = 16), followed by application of the Flatsonic ultrasonic tip in the cervical and middle thirds and a PDL 25/0.03 file in the apical third (FPDL). The teeth were scanned using micro-computed tomography before and after the procedures. The percentage of volume increase, debris, and uninstrumented surface area were analyzed using the Kruskal-Wallis, Dunn, Wilcoxon, analysis of variance/Tukey, and paired and unpaired t -tests (α = 0.05)., Results: No significant difference was found in the volume increase and uninstrumented surface area between PDL and HEDM ( p > 0.05). PDL had a higher percentage of debris than HEDM in the middle and apical thirds ( p < 0.05). The FPDL protocol resulted in less debris and uninstrumented surface area for PDL and HEDM ( p < 0.05). This protocol, with HEDM, reduced debris in the middle and apical thirds and uninstrumented surface area in the apical third ( p < 0.05)., Conclusions: High percentages of debris and uninstrumented surface area were observed after preparation of flattened root canals. The HEDM, Flatsonic tip, and 25/0.03 instrument protocol enhanced cleaning in flattened root canals., Competing Interests: Conflict of Interest: No potential conflict of interest relevant to this article was reported., (Copyright © 2021. The Korean Academy of Conservative Dentistry.)

Cancer is a major global public health problem and conventional chemotherapy has several adverse effects and deficiencies. As a valuable option for chemotherapy, nanomedicine requires novel agents to increase the effects of antineoplastic drugs in multiple cancer models. Since its discovery, carbon nanotubes (CNTs) are intensively investigated for their use as carriers in drug delivery applications. This study shows the development of a nanovector generated with commercial carbon nanotubes (cCNTs) that were oxidized (oxCNTs) and chemically functionalized with hyaluronic acid (HA) and loaded with carboplatin (CPT). The nanovector, oxCNTs-HA-CPT, was used as a treatment against HeLa and MDA-MB-231 human tumor cell lines. The potential antineoplastic impact of the fabricated nanovector was evaluated in human cervical adenocarcinoma (HeLa) and mammary adenocarcinoma (MDA-MB-231). The oxCNTs-HA-CPT nanovector demonstrate to have a specific antitumor effect in vitro. The functionalization with HA allows that nanovector bio-directed towards tumor cells, while the toxicity effect is attributed mainly to CPT in a dose-dependent manner.

Background: Silica nanoparticles (nanoSiO 2 ) are promising systems that can deliver biologically active compounds to tissues such as the heart in a controllable manner. However, cardiac toxicity induced by nanoSiO 2 has been recently related to abnormal calcium handling and energetic failure in cardiomyocytes. Moreover, the precise mechanisms underlying this energetic debacle remain unclear. In order to elucidate these mechanisms, this article explores the ex vivo heart function and mitochondria after exposure to nanoSiO 2 ., Results: The cumulative administration of nanoSiO 2 reduced the mechanical performance index of the rat heart with a half-maximal inhibitory concentration (IC 50 ) of 93 μg/mL, affecting the relaxation rate. In isolated mitochondria nanoSiO 2 was found to be internalized, inhibiting oxidative phosphorylation and significantly reducing the mitochondrial membrane potential (ΔΨ m ). The mitochondrial permeability transition pore (mPTP) was also induced with an increasing dose of nanoSiO 2 and partially recovered with, a potent blocker of the mPTP, Cyclosporine A (CsA). The activity of aconitase and thiol oxidation, in the adenine nucleotide translocase, were found to be reduced due to nanoSiO 2 exposure, suggesting that nanoSiO 2 induces the mPTP via thiol modification and ROS generation. In cardiac cells exposed to nanoSiO 2 , enhanced viability and reduction of H 2 O 2 were observed after application of a specific mitochondrial antioxidant, MitoTEMPO. Concomitantly, CsA treatment in adult rat cardiac cells reduced the nanoSiO 2 -triggered cell death and recovered ATP production (from 32.4 to 65.4%). Additionally, we performed evaluation of the mitochondrial effect of nanoSiO 2 in human cardiomyocytes. We observed a 40% inhibition of maximal oxygen consumption rate in mitochondria at 500 μg/mL. Under this condition we identified a remarkable diminution in the spare respiratory capacity. This data indicates that a reduction in the amount of extra ATP that can be produced by mitochondria during a sudden increase in energy demand. In human cardiomyocytes, increased LDH release and necrosis were found at increased doses of nanoSiO 2 , reaching 85 and 48%, respectively. Such deleterious effects were partially prevented by the application of CsA. Therefore, exposure to nanoSiO 2 affects cardiac function via mitochondrial dysfunction through the opening of the mPTP., Conclusion: The aforementioned effects can be partially avoided reducing ROS or retarding the opening of the mPTP. These novel strategies which resulted in cardioprotection could be considered as potential therapies to decrease the side effects of nanoSiO 2 exposure.

Gold nanoparticles (AuNPs) are considered valuable nanomaterials for the design of radiolabeled nanoprobes for single-photon emission computed tomography (SPECT) imaging. Radiolabeled and functionalized AuNPs could improve lymphatic mapping by enhancing the radioactive signaling of individual particles in the sentinel node. In this study, an alternative method for functionalizing commercial AuNps with mannose is described. The chemical derivatization and biofunctionalization of AuNPs were performed with lipoic acid and mannose, respectively. Several levels of mannose were tested; the thiolate hydrazinonicotinamide-glycine-glycine-cysteine (HYNIC) molecule was also used for 99m Tc radiolabeling. Physicochemical characterization of this system includes U-V spectroscopy, dynamic light scattering, Fourier-transform infrared spectroscopy, and transmission electron microscopy. The most stable nanoprobe, in terms of the aggregation, radiolabeling efficiency, and purity, was tested in a sentinel lymph node model in a rat by microSPECT/computed tomography (CT) imaging. The SPECT images revealed that 99m Tc-radiolabeled AuNPs functionalized with mannose can track and accumulate in lymph nodes in a similar way to the commercial 99m Tc-Sulfur colloid, commonly used in clinical practice for sentinel lymph node detection. These promising results support the idea that 99m Tc-AuNPs-mannose could be used as a SPECT contrast agent for lymphatic mapping.

The noncovalent bonding between nucleobases (NBs) and Stone-Wales (SW) defect-containing closed-end single-walled carbon nanotubes (SWNTs) was theoretically studied in the framework of density function theory using a dispersion-corrected functional PBE-G06/DNP. The models employed in this study were armchair nanotube (ANT) (5,5) and zigzag nanotube (ZNT) (10,0), which incorporated SW defects in different orientations. In one of them, the (7,7) junction is tilted with respect to SWNT axis (ANT-t and ZNT-t), whereas in ANT-p and ZNT-p models the (7,7) junction is parallel and perpendicular to the axis, respectively. The binding energies for uracil, thymine, cytosine, 5-methylcytosine, adenine, and guanine interacting with the defect-containing nanotube models were compared to the values previously obtained with the same calculation technique for the case of defect-free SWNTs, both in the gas phase (vacuum) and in aqueous medium. For most models, the interaction strength tends to be higher for purine than for pyrimidine complexes, with a clear exception of the systems including ZNT-p, both in vacuum and in aqueous medium. As it could be expected, the binding strength in the latter case is lower as compared to that in vacuum, roughly by 2-4 kcal/mol, due to the implicit inclusion of a medium (i.e., water) via the conductor-like screening model model. The closest contacts between NBs and SWNT models, frontier orbital distribution, and highest-occupied molecular orbital-lowest-unoccupied molecular orbital gap energies are analyzed as well. © 2019 Wiley Periodicals, Inc., (© 2019 Wiley Periodicals, Inc.)

Imidazo[1,2- a ]pyrazines are cyclic amidine-type compounds composed of α-amino acid residues. A full structural identification of these molecules constitutes an analytical challenge, especially when imidazo[1,2- a ]pyrazines are obtained from physical processes (e.g., sublimation and pyrolysis of amino acids). A valuable source of molecular information can be obtained from absorption spectroscopies and related techniques encompassing the use of metallic substrates. The aim of this study is to provide new knowledge and insights into the noncovalent intermolecular interactions between imidazo[1,2- a ]pyrazines and two Ag n ( n = 4 and 20) clusters using density functional theory (DFT) methods. Semiempirical DFT dispersion (DFT-D) corrections were addressed using Grimme's dispersion (GD2) and Austin-Petersson-Frisch (APF) functionals in conjunction with the 6-31+G( d , p ) + LANL2DZ mixed basis set. These DFT-D methods describe strong interactions; besides, in all cases, the APF dispersion (APF-D) energies of interaction appear to be consistently overestimated. In comparison with B3LYP calculations, the mean values for the difference in the energies of interaction calculated are 2.25 (GD2) and 6.24 (APF-D) kcal mol -1 for Ag 4 -molecules, and 2.30 (GD2) and 8.53 (APF-D) kcal mol -1 for Ag 20 -molecules. The effect of applying GD2 and APF-D corrections to the noncovalent complexes is nuanced in the intermolecular distances calculated, mainly in the Ag···N(amidine) bonding, which appears to play the most important role for the adsorptive process. Selective enhancement and considerable red shifts for Raman vibrations suggest strong interactions, whereas a charge redistribution involving the metallic substrate and the absorbate leads to a significant rearrangement of frontier molecular orbitals mainly in the Ag 20 -molecule complexes. Finally, time-dependent DFT calculations were carried out to access the orbital contributions to each of the transitions observed in the absorption spectrum. The corresponding UV-vis spectra involve transitions in the visible region at around 400 and 550 nm for the Ag 4 -molecule and the Ag 20 -molecule complexes, respectively., Competing Interests: The author declares no competing financial interest., (Copyright © 2019 American Chemical Society.)

Carbon nanotubes (CNTs) have emerged in recent years as a potential option for drug delivery, due to their high functionalization capacity. Biocompatibility and selectivity using tissue-specific biomolecules can optimize the specificity, pharmacokinetics and stability of the drug. In this study, we design, develop and characterize a drug nanovector (oxCNTs-HA-CPT) conjugating oxidated multi-wall carbon nanotubes (oxCNTs) with hyaluronate (HA) and carboplatin (CPT) as a treatment in a lung cancer model in vitro. Subsequently, we exposed TC-1 and NIH/3T3 cell lines to the nanovectors and measured cell uptake, cell viability, and oxidative stress induction. The characterization of oxCNTs-HA-CPT reveals that on their surface, they have HA. On the other hand, oxCNTs-HA-CPT were endocytosed in greater proportion by tumor cells than by fibroblasts, and likewise, the cytotoxic effect was significantly higher in tumor cells. These results show the therapeutic potential that nanovectors possess; however, future studies should be carried out to determine the death pathways involved, as well as their effect on in vivo models.

Introduction: Calcium silicate-based materials have been proposed as root canal sealers for root canal treatment. The aim of this study was to evaluate the physicochemical properties of a new calcium silicate-based sealer (Bio-C Sealer; Angelus, PR, Brazil) compared with a calcium silicate endodontic sealer (TotalFill BC Sealer; FKG Dentaire SA, La Chaux-de-Fonds, Switzerland) and an epoxy resin sealer (AH Plus; Dentsply DeTrey, Konstanz, Germany)., Methods: The setting time and flow were evaluated based on ISO 6876 standard. The pH value was evaluated after different time intervals of storage in deionized water (1, 7, 14, and 21 days). Radiopacity was evaluated by radiographic analysis in millimeters of aluminum. Solubility and volumetric change were evaluated after 30 days of immersion in distilled water. Solubility was assessed by mass loss (%), and volumetric change was evaluated by micro-computed tomographic imaging. The data were submitted to analysis of variance and Tukey statistical tests (P < .05)., Results: TotalFill BC Sealer and Bio-C Sealer were similar regarding radiopacity, volumetric change, and pH values (P > .05). Bio-C Sealer presented the shortest setting time and the highest flow and solubility (P < .05). AH Plus showed the highest radiopacity and the lowest flow, pH, solubility, and volumetric change (P < .05)., Conclusions: Bio-C Sealer showed a short setting time, alkalinization ability, and adequate flow and radiopacity as well as low volumetric change. However, this sealer had higher solubility than the rates required by ISO 6876 standard., (Copyright © 2019 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Surface modification in nanostructured mesoporous silica particles (MSNs) can significantly increase the uptake in myocardial cells. Herein, MSNs particles were synthesized and chemically functionalized to further assess their biocompatibility in rat myocardial cell line H9c2. The surface modification resulted in particles with an enhanced cellular internallization (3-fold increase) with respect to pristine particles. Apoptosis events were not evident at all, while necrosis incidence was significant only at a higher doses (>500μg/mL). In particular, the percentage of necrotic cells decrease in a statistically significant manner for the functionalized particles at lower doses than 100μg/mL. This study concludes that the proposed surface functionalization of MSNs particles does not compromise their viability on H9c2 cells, and therefore they could potentially be used for biomedical purposes. Fourier-transform infrared, Raman, TGA/DSC, N 2 adsorption-desorption, and TEM techniques were used to characterize the as-prepared materials. Confocal microscopy and flow cytometry analyses were carried out to measure the histograms of cell complexity and the half maximal inhibitory concentration, respectively. Reactive oxygen species generation was accessed using assays with MitoSOX and Amplex Red fluoroprobes., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Given the well-known physical properties of graphene oxide (GO), numerous applications for this novel nanomaterial have been recently envisioned to improve the performance of biomedical devices. However, the toxicological assessment of GO, which strongly depends on the used material and the studied cell line, is a fundamental task that needs to be performed prior to its use in biomedical applications. Therefore, the toxicological characterization of GO is still ongoing. This study contributes to this, aiming to synthesize and characterize GO particles and thus investigate their toxic effects in myocardial cells. Herein, GO particles were produced from graphite using the Tour method and subsequent mild reduction was carried out to obtain low-reduced GO (LRGO) particles. A qualitative analysis of the viability, cellular uptake, and internalization of particles was carried out using GO (~54% content of oxygen) and LRGO (~37% content of oxygen) and graphite. GO and LRGO reduce the viability of cardiac cells at IC 50 of 652.1±1.2 and 129.4±1.2μg/mL, respectively. This shows that LRGO particles produce a five-fold increase in cytotoxicity when compared to GO. The cell uptake pattern of GO and LRGO particles demonstrated that cardiac cells retain a similar complexity to control cells. Morphological alterations examined with electron microscopy showed that internalization by GO and LRGO-treated cells (100μg/mL) occurred affecting the cell structure. These results suggest that the viability of H9c2 cells can be associated with the surface chemistry of GO and LRGO, as defined by the amount of oxygen functionalities, the number of graphitic domains, and the size of particles. High angle annular dark-field scanning transmission electron microscopy, dynamic light-scattering, Fourier-transform infrared, Raman, and X-ray photoelectron spectroscopies were used to characterize the as-prepared materials., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Functionalization of thin films with organic ligands has been the subject of intense research due to their potential application as heterogeneous molecular nanosystems. In this work, self-assembled monolayers of thiols (16-mercaptohexadecanoic acid and 11-mercaptoundecanol) were used to bind laccase (from Pycnoporus sanguineus CS43) to nanostructured gold thin films obtained by DC sputtering. Sputtering power, sputtering pressure and substrate temperature were optimized to enhance the activity of the immobilized biomolecules. Scanning electron microscopy, confocal microscopy, X-ray diffraction and UV-vis spectroscopy were used to characterize the SAM-functionalized gold substrates. Our results demonstrate that the highest immobilized enzyme activity values can be achieved on substrates of surface roughness ˜200 nm and Au particle size of about 14 nm. The outstanding quality of the as-prepared substrates makes them particularly attractive as bionanosensors.

Objectives: The aim of this study was to evaluate the efficacy of two passive ultrasonic irrigation (PUI) methods and conventional manual irrigation (CMI) in root canal system (RCS) cleaning., Materials and Methods: Artificial single-rooted teeth were used. Four lateral canals were made 2 and 7 mm short from the apex. Root canals were filled with a contrast solution. The specimens were divided into four groups (n = 8): PUI1-intermittent flushing; PUI2-continuous flushing; CMI1-at 1 mm; and CMI2-at 3 mm. Micro-computed tomographic images were obtained. New images were taken after the irrigation protocols enabling the evaluation of the contrast solution volume (in mm(3)) within RCS (main and lateral root canals) in comparison to the initial analysis. The comparison among groups was performed using ANOVA and Tukey's tests with 5 % significance level., Results: There was no difference among PUI1, PUI2, and CMI1 regarding the contrast solution removal from RCS (p > 0.05). These methods demonstrated greater cleaning than CMI2. At the apical third, CMI2 showed lower cleaning capacity when compared to the other methods (p < 0.05)., Conclusions: PUI with intermittent or continuous flushing and CMI with the needle placed 1 mm from the working length were efficient in cleaning the main and lateral root canals., Clinical Relevance: Root canal irrigation plays an important role in cleaning and disinfection of the RCS. Effective apical irrigation is an important procedure during root canal treatment. PUI and CMI (at 1 mm short) were effective in cleaning of the main and simulated lateral root canals.

Objective: The aim of this study was to compare the cleaning of main and lateral canals using the irrigation methods: negative pressure irrigation (EndoVac system), passive ultrasonic irrigation (PUI) and manual irrigation (MI)., Materials and Methods: Resin teeth were used. After root canal preparation, four lateral canals were made at 2 and 7 mm from the apex. Root canals were filled with contrast solution and radiographed pre- and post-irrigation using digital radiographic system [radiovisiography (RVG)]. The irrigation protocols were: MI1-manual irrigation [22 G needle at 5 mm short of working length-WL]; MI2-manual irrigation (30G needle at 2 mm short of WL); PUI; EV1-EndoVac (microcannula at 1 mm short of WL); EV2-Endovac (microcannula at 3 mm short of WL). The obtained images, initial (filled with contrast solution) and final (after irrigation) were analyzed by using image tool 3.0 software. Statistical analysis was performed by analysis of variance (ANOVA) and Tukey tests (5% significance level)., Results: EV1 and EV2, followed by PUI showed better cleaning capacity than manual irrigation (MI1 and MI2) (p < 0.05)., Conclusion: Negative pressure irrigation and PUI promoted better cleaning of main and simulated lateral canals., Clinical Significance: Conventional manual irrigation technique may promote less root canal cleaning in the apical third. For this reason, the search for other irrigation protocols is important, and EndoVac and PUI are alternatives to contribute to irrigation effectiveness.

Nanostructure derivatives of fullerene C(60) are used in emerging applications of composite matrices, including protective and decorative coating, superadsorbent material, thin films, and lightweight high-strength fiber-reinforced materials, etc. In this study, quantum chemical calculations and experimental studies were performed to analyze the derivatives of diamine-fullerene prepared by the gas-phase solvent-free functionalization technique. In particular, the aliphatic 1,8-diamino-octane and the aromatic 1,5-diaminonaphthalene, which are diamines volatile in vacuum, were studied. We addressed two alternative mechanisms of the amination reaction via polyaddition and cross-linking of C(60) with diamines, using the pure GGA BLYP, PW91, and PBE functionals; further validation calculations were performed using the semiempirical dispersion GGA B97-D functional which contains parameters that have been specially adjusted by a more realistic view on dispersion contributions. In addition, we looked for experimental evidence for the covalent functionalization by using laser desorption/ionization time-of-flight mass spectrometry, thermogravimetric analysis, and atomic force microscopy.

The furniture ergonomic evaluation was carried out through the use of questionnaires and forms in industries. For the ergonomic product analysis, it was used the methodology "Object Ergonomics - Ergonomic System Technical Reading" (design goals and management actions), and measurements of products. The values achieved were compared with the standard dimensions, and the compliance or non-compliance of the furniture to it was assessed. In relation to the dimensions of the bed, the following variables did not comply with the norms: external and internal length, external and internal width, height and width of the sidebar and distance to the floor. The dimensions of these variables were above the recommended values. The double bed was inadequate for management actions and maintenance. Since the kitchen cabinet is a product that went through physical testing and follows national standards; the finish used is powder coating. The kitchen cabinet proved to be appropriate in all design requirements and for management actions. Both furniture pieces were inadequate, considering the difficulty for maintenance when a product or part of it was damaged. It was recommended the creation of regulatory standards for the production of safe and comfortable furniture.

Short pristine multi-walled carbon nanotubes (MWNTs) were functionalized with a series of long-chain (including polymeric) aliphatic amines, namely octadecylamine (ODA), 1,8-diaminooctane (DO), polyethylene glycol diamine (PEGDA) and polyethylenimine (PEI), via two "green" approaches: (1) gas-phase functionalization (for volatile ODA and DO) and (2) direct heating in the melt (for polymeric PEGDA and PEI). Both of them consist in one-step reaction between MWNTs and amine without the use of organic solvents. The nanostructures obtained were characterized by using infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, atomic force microscopy, and transmission electron microscopy. It was observed that both solvent-free methods were efficient in the nanotube functionalization, and the nanostructures of variable solubility and morphology were obtained depending on the amines attached. ODA, PEGDA and PEI-functionalized MWNTs were found to be soluble in propanol, meanwhile the MWNTs-PEGDA and MWNTs-PEI were soluble in water as well. The attachment of 1,8-diaminooctane onto MWNTs resulted in cross-linked stable nanostructure.

Human serum albumin (HSA) is the most abundant protein in blood plasma showing a remarkable ability to bind a broad range of hydrophobic substrates. We employed scanning tunneling microscopy and atomic force microscopy to characterize the morphology of HSA aggregates on highly-ordered pyrolytic graphite (HOPG) and single-walled carbon nanotubes (SWNTs). The morphologies found for albumin aggregates on HOPG are quite different from the ones observed on SWNTs. On HOPG, HSA forms aggregates of roughly 10-20 molecules; single protein molecules were observed as well. In the case of SWNTs, nanotubes were partially or totally covered with HSA, exhibiting four general types of aggregation: (i) SWNT sidewalls contain single molecules of albumin which are away from each other at distances longer than the HSA molecular size; (ii) SWNTs are completely covered with HSA, which forms a thin and relatively homogeneous layer; (iii) SWNTs have a complete layer of HSA with additional accumulation of protein at separate sites; and (iv) several SWNTs totally covered with albumin assemble into a bundle-like structure common for bare nanotubes. These observations are interpreted in terms of stronger interactions of HSA with nanotube sidewalls than with flat graphite surface.

To attempt theoretical predictions of the regioselectivity pattern in molecules with multiple reactive sites, the energies of formation of all possible isomers are usually considered. This means that the computing becomes highly demanding if high theoretical levels are used. The study objective was to predict the regioselectivity in the reaction of hydrogen addition onto azahydro[60]fullerene C 59H n+1 N ( n = 0-4) systems using a new reactivity indicator termed general-purpose reactivity indicator, Xi Delta N

In this work, we have explored new stable structures of the Au32Z (Z = +1, 0, -1) clusters. Theoretical calculations using density functional theory within the generalized-gradient approximation were performed. Our results show that, in the anion state (Au32-), low-symmetry (disordered) structures are preferred over the caged fullerene-like isomer. In addition, the cationic cluster (Au32+) also exhibits a disordered low-symmetry structure as its lowest energy configuration, but it is much closer in energy to the fullerene-like isomer. These results, obtained at T = 0 K, indicate that disordered structures for the Au32- and Au32+ clusters may be detected not only at room temperature, as was experimentally verified for the Au32- one, but also at much lower temperatures.

Imidazo[1,2-a]pyrazine-3,6-diones are unusual compounds composed of three alpha-amino acid fragments. These bicyclic amidines (BCAs) form under high temperatures or with the use of strong dehydrating reagents. We gave insight into the mechanisms of BCA formation via gas-phase pyrolytic and silica-catalyzed reactions of glycine (Gly) and alpha-aminoisobutyric acid (AIB) with related diketopiperazines (DKPs), using quantum chemical calculations. The entire process requires four steps: (1) O-acylation of DKP with free or silica-bonded amino acid, (2) acyl transfer from the oxygen to the nitrogen atom, (3) intramolecular condensation of the N-acyl DKP into a cyclol, and (4) elimination of water. To study step (1) at silica surface (modeled by H7Si8O12-OH cluster), we employed two-level ONIOM calculations (AM1:UFF, B3LYP/3-21G:UFF and B3LYP/6-31G(d):UFF); all gas-phase reactions were studied at the AM1, B3LYP/3-21G and B3LYP/6-31G(d) levels. The catalytic effect of silica was observed for both Gly and AIB: the activation energy in the O-acylation at the surface was lower by more than 9 kcal mol(-1) as compared to the gas-phase process. Contrary to the exothermic O-acylation, the gas-phase transfer reaction (step 2) was exothermic in both cases, but more favorable for Gly. The cyclocondensation of N-acylated DKPs into BCAs (steps 3 and 4) is endothermic for Gly and exothermic for AIB.

Imidazo[1,2-a]pyrazine-3,6-diones and imidazo[1,2-a]imidazo[1,2-d]pyrazine-3,8-diones can be produced by pyrolysis of simple amino acids. While such bicyclic and tricyclic amidines were detected and characterized by IR spectroscopy for some alpha-substituted amino acids, the parent systems composed of glycine fragments are unknown up to now. IR spectra for five amidines derived from glycine were calculated by using different semi-empirical (PM3, AM1, MNDO and MINDO/3), HF, and hybrid DFT (B3LYP, B3P86 and B3PW91) methods in conjunction with 6-31G(d) basis set (for HF and DFT). Vibration frequencies in the experimental IR spectra were predicted based upon the B3LYP data, by correcting the calculated wavenumbers by a scaling factor of 0.959. The behavior of most characteristic bands (nu(CX), nu(NH), etc.) and their shifts with respect to such bands in the spectra of alanine and alpha-aminoisobutyric acid derivatives studied before, are discussed. Performance of the semi-empirical methods was tested, bearing in mind possible future needs for IR spectra predictions for larger molecular systems of similar chemical nature; the use of MINDO/3 and MNDO is recommended. A basis set effect on the B3LYP fundamental vibration frequencies for hexahydroimidazo[1,2-a]pyrazine-3,6-dione was studied by varying Pople basis sets from minimal STO-3G to 6-311++G(d, p). No significant improvements were found beyond the 6-31G(d) basis set, which thus can be recommended to predict IR spectra for the amidines and similar molecules.