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3D printing ultralightweight porous structures using direct ink writing (DIW) while maintaining their mechanical robustness is highly challenging. This difficulty is amplified when low ink concentrations are used to create complex geometries. Herein, this shortfall was addressed by interfacially jammed emulsion gels. The gel emerged from the electrostatic interaction among synergized nanomaterials (graphene oxide (GO) and cellulose nanocrystals (CNCs)) in the aqueous phase and a ligand in the oil phase. This interaction led to the jamming of the nanoparticles and the creation of stable emulsion gels. The formed interfacial assemblies were further treated by post-jamming ionic cross-linking with NaHCO3, which dictated the emulsion gels' rheological characteristics, enhancing the ink's viscoelastic properties for high-resolution 3D printing. The customizable emulsion system allows control over porosity from the macro- to the micro-scale and generates complex geometries with desired compositions. By manipulating post-annealing processes and varying concentrations, it is possible to achieve aerogels that feature a remarkably low density (â¼2.63 mg/cm3) and adjustable mechanical robustness (elastic modulus of 0.45 MPa). Additionally, this method allows for producing aerogels with flexible or stiff characteristics as required, alongside the capability to tailor specific electromagnetic shielding effectiveness (ranging from 6791 to 19615 dB cm2/g), showcasing the technique's versatility and engineerability.
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Technological fusion of emerging three-dimensional (3D) printing of aerogels with gel processing enables the fabrication of lightweight and functional materials for diverse applications. However, 3D-printed constructs via direct ink writing for fabricating electrically conductive structured biobased aerogels suffer several limitations, including poor electrical conductivity, inferior mechanical strength, and low printing resolution. This work addresses these limitations via molecular engineering of conductive hydrogels. The hydrogel inks, namely, CNC/PEDOT-DBSA, featured a unique formulation containing well-dispersed cellulose nanocrystal decorated by a poly(3,4-ethylene dioxythiophene) (PEDOT) domain combined with dodecylbenzene sulfonic acid (DBSA). The rheological properties were precisely engineered by manipulating the solid content and the intermolecular interactions among the constituents, resulting in 3D-printed structures with excellent resolution. More importantly, the resultant aerogels following freeze-drying exhibited a high electrical conductivity (110 ± 12 S m-1), outstanding mechanical properties (Young's modulus of 6.98 MPa), and fire-resistance properties. These robust aerogels were employed to address pressing global concerns about electromagnetic pollution with a specific shielding effectiveness of 4983.4 dB cm2 g-1. Importantly, it was shown that the shielding mechanism of the 3D printed aerogels could be manipulated by their geometrical features, unraveling the undeniable role of additive manufacturing in materials design.
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Small animals do not replicate the severity of the human foreign-body response (FBR) to implants. Here we show that the FBR can be driven by forces generated at the implant surface that, owing to allometric scaling, increase exponentially with body size. We found that the human FBR is mediated by immune-cell-specific RAC2 mechanotransduction signalling, independently of the chemistry and mechanical properties of the implant, and that a pathological FBR that is human-like at the molecular, cellular and tissue levels can be induced in mice via the application of human-tissue-scale forces through a vibrating silicone implant. FBRs to such elevated extrinsic forces in the mice were also mediated by the activation of Rac2 signalling in a subpopulation of mechanoresponsive myeloid cells, which could be substantially reduced via the pharmacological or genetic inhibition of Rac2. Our findings provide an explanation for the stark differences in FBRs observed in small animals and humans, and have implications for the design and safety of implantable devices.
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Reação a Corpo Estranho , Mecanotransdução Celular , Camundongos , Humanos , Animais , Próteses e Implantes , Células Mieloides/patologia , Transdução de SinaisRESUMO
Sesame oil (SO), one of the most popular and expensive edible oils, is prone to adulteration. In this study, the fatty acid profiles of pure sesame seed oil and samples adulterated with two less expensive edible oils (canola and sunflower) were analyzed using Gas Chromatography. A dedicated e-nose system was developed and tested on 15 mixtures of sesame-canola and sesame-sunflower samples. Principal Component Analysis (PCA), Linear Discriminant Analysis (LDA), and Multi-Layered Perceptron (MLP) methods were utilized to identify adulteration through the evaluation of Volatile Organic Compound. Result of chromatography showed that most samples of sesame oil containing impurities at levels less than 30% were recognized incorrectly in the standard range of SO fatty acids. This is while the developed e-nose system was able to detect adulteration at much lower levels. According to the results, PCA and LDA methods can describe the data set variance with precision of 95.6% and 97%, respectively. The MLP model had better results compared to PCA and LDA, with high determination coefficient (R2 = 0.981) and low RMSE (0.0178). Results indicate that the e-nose system provided an effective non-destructive method to detect SO adulteration at levels as low as 5%, which GC was unable to detect.
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Functional near-infrared spectroscopy (fNIRS) is an optical imaging technique for assessing human brain activity by noninvasively measuring the fluctuation of cerebral oxygenated- and deoxygenated-hemoglobin concentrations associated with neuronal activity. Owing to its superior mobility, low cost, and good tolerance for motion, the past few decades have witnessed a rapid increase in the research and clinical use of fNIRS in a variety of psychiatric disorders. In this perspective article, we first briefly summarize the state-of-the-art concerning fNIRS research in psychiatry. In particular, we highlight the diverse applications of fNIRS in psychiatric research, the advanced development of fNIRS instruments, and novel fNIRS study designs for exploring brain activity associated with psychiatric disorders. We then discuss some of the open challenges and share our perspectives on the future of fNIRS in psychiatric research and clinical practice. We conclude that fNIRS holds promise for becoming a useful tool in clinical psychiatric settings with respect to developing closed-loop systems and improving individualized treatments and diagnostics.
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Engineering the rheological properties of colloidal inks is one of the main challenges in achieving high-fidelity 3D printing. Herein, we provide a comprehensive study on the rheological behavior of inks based on cellulose nanocrystals (CNCs) in the presence of given salts to enable high-quality 3D printing. The rheological properties of the CNC suspensions are tailored by considering the nature of the electrolyte (i.e., 10 types of salts featuring different ion sizes, charge numbers, and inter- and intra-molecular interactions) at various concentrations (25-100 mM). A high printing fidelity is achieved in a narrow CNC and salt concentration range, significantly depending on the salt type. The structure-property relationship is explored in a "3D-printing" space (2D map), introducing a guideline for researchers active in this field. To further unravel the effect of salt type on morphological properties, CNC aerogels are developed by freeze-drying the printed structures. The results illustrate that enhancing viscoelastic properties render a denser structure featuring smaller pores.
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Celulose , Nanopartículas , Celulose/química , Tinta , Sais , Impressão Tridimensional , Cloreto de Sódio/química , Nanopartículas/químicaRESUMO
The development of advanced electrode materials and the combination of aptamer with them have improved dramatically the performance of aptasensors. Herein, a new architecture based on copper hydroxide nanorods (Cu(OH)2 NRs) are directly grown on the surface of screen printed carbon electrode (SPCE) using a two-step in situ, very simple and fast strategy and was used as a high-performance substrate for immobilization of aptamer strings, as well as an electrochemical probe to development a label-free electrochemical aptasensor for SARS-CoV-2 spike glycoprotein measurement. The Cu(OH)2 NRs was characterized using X-ray Diffraction (XRD) and electron microscopy (FESEM). In the presence of SARS-CoV-2 spike glycoprotein, a decrease in Cu(OH)2 NRs-associated peak current was observed that can be owing to the target-aptamer complexes formation and thus blocking the electron transfer of Cu(OH)2 NRs on the surface of electrode. This strategy exhibited wide dynamic range in of 0.1 fg mL-1 to 1.2 µg mL-1 and with a high sensitivity of 1974.43 µA mM-1 cm-2 and low detection limit of 0.03 ± 0.01 fg mL-1 of SARS-CoV-2 spike glycoprotein deprived of any cross-reactivity in the presence of possible interference species. In addition, the good reproducibility, repeatability, high stability and excellent feasibility in real samples of saliva and viral transport medium (VTM) were found from the provided aptasensor. Also, the aptasensor efficiency was evaluated by real samples of sick and healthy individuals and compared with the standard polymerase chain reaction (PCR) method and acceptable results were observed.
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Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , COVID-19 , Nanotubos , Aptâmeros de Nucleotídeos/química , Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodos , Eletrodos , Humanos , Reprodutibilidade dos Testes , SARS-CoV-2 , Glicoproteína da Espícula de CoronavírusRESUMO
Eco-friendly nanocomposite aerogels were prepared as adsorbents for the removal of a model pollutant (methylene blue, MB) from water. These aerogels were comprised of hydroxyapatite (HA) nanoparticles embedded within a polymer matrix consisting of a semi-interpenetrating network of xanthan gum (XG) and polyacrylic acid (PAA). Microscopy and BET analysis showed that the aerogels formed had a nanofibrous porous microstructure with a surface area of 89 m2/g. Rheological analysis showed that the aerogels were viscoelastic materials whose elasticity increased with increasing HA concentration (up to 5 w/w%). The aerogels were effective at removing MB from water, exhibiting an adsorption capacity of 130 mg/g after 200 min. The binding of the MB to the aerogels was mainly attributed to hydrogen bonding and electrostatic attraction. A reusability test showed that the MB removal efficiency of over 86% was preserved after 10 cycles of adsorption-desorption. These results suggest that our nanocomposite aerogels may be useful for the efficient removal of anionic pollutants from wastewater and water supplies due to their ease of synthesis, cost-effectiveness, good mechanical properties, high thermal stability, and good adsorption performance.
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Nanocompostos , Poluentes Químicos da Água , Resinas Acrílicas , Adsorção , Durapatita , Azul de Metileno/química , Nanocompostos/química , Polissacarídeos Bacterianos , Águas Residuárias , Poluentes Químicos da Água/químicaRESUMO
In this study, environmentally-friendly nanocomposite hydrogels were fabricated. These hydrogels consisted of semi-interpenetrating networks of carboxymethyl cellulose (CMC) molecules grafted to polyacrylic acid (PAA), as an eco-friendly and non-toxic polymer with numerous carboxyl and hydroxyl functional groups, which were reinforced with different levels of graphene oxide particles (0.5, 1.5 or 3% wt). Field-emission electron scanning microscopy (FESEM) images indicated that the pore size of the nanocomposites decreased with increasing graphic oxide concentration. The presence of the graphic oxide increased the storage modulus and thermal stability of the nanocomposite hydrogels. The hydrogels had an adsorption capacity of 138 mg/g of a model cationic dye pollutant (methylene blue) after 250 min. Moreover, a reusability test showed that the adsorption capacity remained at around 90% after 9 cycles. Density functional theory (DFT) simulations suggested that the adsorption of methylene blue was mainly a result of π-π bonds, hydrogen bonds, and electrostatic interactions with graphene oxide. Our results indicated that the nanocomposite hydrogels fabricated in this study may be eco-friendly, stable, efficient, and reusable adsorbents for ionic pollutants in wastewater treatment.
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Nanocompostos , Poluentes Químicos da Água , Resinas Acrílicas , Adsorção , Carboximetilcelulose Sódica , Corantes , Grafite , Cinética , Azul de Metileno , Águas ResiduáriasRESUMO
During recent decades, we have witnessed a great improvement in the performance of aptamer-based sensors, specifically when aptamers are combined with new nanomaterials; as a platform for biosensors. The design of hollow carbon-based materials has also received a lot of attention due to its excellent properties in various applications. Herein, we aim at designing hierarchical porous Ni(OH)2 nanosheets on hollow N-doped carbon nanoboxes Ni(OH)2@N-C n-box). In this sense, we obtained the hollow N-C n-box skeletons from the Fe2O3 nanocubes template. The development of label-free electrochemical aptasensor was carried out using the covalently immobilizing NH2-functionalized aptamer on Ni(OH)2@N-C n-box as an efficient substrate. The Ni(OH)2@N-C n-box was characterized using scanning fourier transform infrared spectroscopy (FTIR), X-ray Diffraction (XRD), Brunauer, Emmett and Teller (BET), transmission electron microscopes (TEM) and electron microscopy (FESEM). The electrochemical evaluations clarified the fact that a linear relationship exists between the alpha-fetoprotein (AFP) contents and the charge transfer resistance (Rct) (from 1 fg mL-1 to 100 ng mL-1) with a low detection limit of 0.3 fg mL-1. Moreover, regarding the aptasensor, the superior detection recoveries were experienced in real biological samples, illustrating its great detection performance and practical feasibility. Considering the aptasensor application, these studies showed that Ni(OH)2@N-C n-box possesses different enhanced electrochemical features, making it appropriate as an electrode material for aptasensor application.
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Neoplasias , alfa-Fetoproteínas , Biomarcadores Tumorais , Carbono , Técnicas Eletroquímicas , Humanos , Hidróxidos , Níquel , NitrogênioRESUMO
As a consequence of industrial activities, one of the most prevalent components in wastewater is Water-soluble dyes needed to be removed. In this research, eco-friendly adsorbents based on poly(glycerol sebacate) (PGS), including PGS-graphene oxide nanoparticles (GO), PGS-graft-chitosan(CS), and PGS-CS-GO nanocomposites, have been proposed as efficient dye adsorbents for the wastewater treatment procedure. FESEM images showed that a smooth and uniform structure was created over incorporating CS into PGS. Besides, the presence of CS within PGS/GO nanocomposites had a positive impact on the exfoliation of GO. Moreover, it was found that the incorporation of both CS and GO into PGS reduced the glass transition of PGS. Besides, their coexistence can probably increase the chain regularity in the polymer matrix and cause a relatively larger crystal size of PGS. In this regard, the ternary nanocomposite saw a Tg value of -29.4 °C. A high adsorption capacity of 178 mg g-1, as well as 99 removal% efficiency, were observed in the case of the PGS-CS-GO sample after 300 min at a dye concentration of 100 mg L-1 and pH 7. Additionally, the adsorption capacity value of the adsorbent was preserved around 129 mg g-1 after 7 cycles of adsorption-desorption. The findings revealed that innovatively synthesized PGS-g-CS/GO nanocomposites could efficiently remove methylene blue from water solutions. Hence, they can be used as a powerful and influential dye adsorbent to purify water solutions.
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Quitosana , Grafite , Nanocompostos , Poluentes Químicos da Água , Adsorção , Corantes , Decanoatos , Glicerol/análogos & derivados , Cinética , Azul de Metileno , Polímeros , Poluentes Químicos da Água/análiseRESUMO
In this study, a novel biopolymer based on poly(glycerol sebacic)-urethane (PGS-U) and its nanocomposites containing Cloisite@30B were synthesized by facile approach in which the crosslinking was created by aliphatic hexamethylene diisocyanate (HDI) at room temperature and 80 °C. Moreover, metronidazole and tetracycline drugs were selected as target drugs and loaded into PGSU based nanocomposites. A uniform and continuous microstructure with smooth surface is observed in the case of pristine PGS-U sample. The continuity of microstructure is observed in the case of all bionanocomposites. XRD result confirmed an intercalated morphology for PGSU containing 5 wt% of clay nanoparticles with a d-spacing 3.4 nm. The increment of nanoclay content up to 5%, the ultimate tensile stress and elastic modulus were obtained nearly 0.32 and 0.83 MPa, which the latter was more than eight-fold than that of pristine PGS-U. A sustained release for both dugs was observed by 200 h. The slowest and controlled drug release rate was determined in the case of PGSU containing 5 wt% clay and cured at 80 °C. A non-Fickian diffusion can be concluded in the case of tetracycline release via PGS-U/nanoclay bionanocomposites, while a Fickian process was detected in the case of metronidazole release by PGS-U/nanoclay bionanocomposites. As a result, the designed scaffold showed high flexibility, which makes it an appropriate option for utilization in the treatment of periodontal disease.
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Glicerol , Nanocompostos , Argila , Decanoatos/química , Sistemas de Liberação de Medicamentos , Glicerol/análogos & derivados , Glicerol/química , Metronidazol , Nanocompostos/química , Polímeros , Tetraciclina , UretanaRESUMO
As a promising approach for serological tests, the present study aimed at designing a robust electrochemical biosensor for selective and quantitative analysis of SARS-CoV-2-specific viral antibodies. In our proposed strategy, recombinant SARS-CoV-2 spike protein antigen (spike protein) was used as a specific receptor to detect SARS-CoV-2-specific viral antibodies. In this sense, with a layer of nickel hydroxide nanoparticles (Ni(OH)2 NPs), the screen-printed carbon electrode (SPCE) surface was directly electrodeposited to ensure better loading of spike protein on the surface of SPCE. The differential pulse voltammetry (DPV) showed signals which were inversely proportional to the concentrations of the antibody (from 1 fg mL-1 L to 1 µg mL-1) via a specific and stable binding reaction. The assay was performed in 20 min with a low detection limit of 0.3 fg mL-1. This biodevice had high sensitivity and specificity as compared to non-specific antibodies. Moreover, it can be regarded as a highly sensitive immunological diagnostic method for SARS-CoV-2 antibody in which no labeling is required. The fabricated hand-held biodevice showed an average satisfactory recovery rate of ~99-103% for the determination of antibodies in real blood serum samples with the possibility of being widely used in individual serological qualitative monitoring. Also, the biodevice was tested using real patients and healthy people samples, where the results are already confirmed using the enzyme-linked immunosorbent assay (ELISA) procedure, and showed satisfactory results.
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INTRODUCTION: short bowel syndrome is marked by inadequate intestinal surface area to absorb nutrients. Current treatments are focused on medical management and surgical reconfiguration of the dilated intestine. We propose the use of spring-mediated distraction enterogenesis as a novel intervention to increase intestinal length. Given our previous success lengthening intestinal segments using springs with spring constant ~7 N/m that exerts 0.46 N or higher, we sought to determine the minimal force needed to lengthen porcine small intestinal segments, and to explore effects on intestine over time. METHODS: Juvenile Yucatan pigs underwent laparotomy with enterotomy to introduce nitinol springs intraluminally (n = 21 springs). Bowel segments (control, spring-distracted) were retrieved on post-operative day (POD) 7 and 14, and lengths measured. Thickness of cross-sectional intestinal layers were measured using H&E, and submucosal collagen fiber orientation measured using trichrome stained sections. RESULTS: all pigs survived to POD7 and 14. Spring constants of at least 2 N/m exerting a minimum force of 0.10 N significantly lengthened intestinal segments (p <0.0001). The stronger the spring force, the greater the induced thickness of various intestinal layers at POD7 and 14. Collagen fiber orientation was also more disordered because of stronger springs. CONCLUSION: a spring constant of approximately 2 N/m exerting 0.10 N and greater significantly lengthens intestinal segments and stimulates intestinal structural changes at POD7 and 14. This suggests a decreased force is capable of inducing spring-mediated distraction enterogenesis.
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Síndrome do Intestino Curto , Dispositivos para Expansão de Tecidos , Animais , Estudos Transversais , Intestino Delgado/cirurgia , Jejuno/cirurgia , Síndrome do Intestino Curto/cirurgia , Suínos , Expansão de TecidoRESUMO
Severe acute respiratory syndrome SARS-CoV-2 has caused a global pandemic starting in 2020. Accordingly, testing is crucial for mitigating the economic and public health effects. In order to facilitate point-of-care diagnosis, this study aims at presenting a label-free electrochemical biosensor as a powerful nanobiodevice for SARS-CoV-2 spike protein detection. Utilizing the IgG anti-SARS-CoV-2 spike antibody onto the electrode surface as a specific platform in an ordered orientation through staphylococcal protein A (ProtA) is highly significant in fabricating the designed nanobiodevice. In this sense, the screen-printed carbon electrode modified with Cu2O nanocubes (Cu2O NCs), which provide a large surface area in a very small space, was applied in order to increase the ProtA loading on the electrode surface. Accordingly, the sensitivity and stability of the sensing platform significantly increased. The electrochemical evaluations proved that there is a very good linear relationship between the charge transfer resistance (Rct) and spike protein contents via a specific binding reaction in the range 0.25 fg mL-1 to 1 µg mL-1. Moreover, the assay when tested with influenza viruses 1 and 2 was performed in 20 min with a low detection limit of 0.04 fg mL-1 for spike protein without any cross-reactivity. The designed nanobiodevice exhibited an average satisfactory recovery rate of ~ 97-103% in different artificial sample matrices, i.e., saliva, artificial nasal, and universal transport medium (UTM), illustrating its high detection performance and practicability. The nanobiodevice was also tested using real patients and healthy samples, where the results had been already obtained using the standard polymerase chain reaction (PCR) procedure, and showed satisfactory results. Graphical abstract.
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Técnicas Biossensoriais/métodos , Teste para COVID-19/métodos , COVID-19/diagnóstico , Cobre/química , Técnicas Eletroquímicas/métodos , Nanoestruturas/química , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/análise , Anticorpos Antivirais/metabolismo , Eletrodos , Humanos , Imunoensaio/métodos , Imunoglobulina G/metabolismo , Ligação Proteica , SARS-CoV-2/metabolismo , Sensibilidade e Especificidade , Proteína Estafilocócica A/química , Propriedades de SuperfícieRESUMO
The design of hollow mesoporous carbon-based materials has attracted tremendous attention, due to their sizeable intrinsic cavity to load specific chemical and unique physical/chemical properties in various applications. Herein, we have established an effective strategy for the preparation of novel hollow carbon nanocapsules-based nitrogen-doped carbon nanofibers (CNCNF) with rosary-like structure. By embedding ultrafine hollow carbon nanocapsules into electrospun polyacrylonitrile (PAN) skeleton, the as-designed composite CNFs were carbonized into hierarchical porous CNFs, consisted of interconnected nitrogen-doped hollow carbon nanocapsules. Due to its individual structural properties and unique chemical composition, the performance of CNCNF was evaluated in aptasensor application via the detection of Pseudomonas aeruginosa (PA). Under optimized conditions, the aptasensor based on CNCNF has a detection limit of 1 CFUâ mL-1 and a linear range from 101 CFU â mL-1 to 107 CFU â mL-1 (n = 3). Moreover, the designed aptasensor possesses high sensivity, high selectivity, low detection limit, and high reproducibility. These studies showed that the CNCNF material offers a wide variety of enhanced electrochemical features as an electrode material for aptasensor application.
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Técnicas Biossensoriais , Nanocápsulas , Nanofibras , Carbono , Técnicas Eletroquímicas , Nitrogênio , Pseudomonas aeruginosa , Reprodutibilidade dos TestesRESUMO
Distraction enterogenesis has been extensively studied as a potential treatment for short bowel syndrome, which is the most common form of intestinal failure. Different strategies including parenteral nutrition and surgical lengthening to manage patients with short bowel syndrome are associated with high complication rates. More recently, self-expanding springs have been used to lengthen the small intestine using an intraluminal axial mechanical force, where this biomechanical force stimulates the growth and elongation of the small intestine. Differences in physical characteristics of patients with short bowel syndrome would require a different mechanical force-this is crucial in order to achieve an efficient and safe lengthening outcome. In this study, we aimed to predict the required mechanical force for each potential intestinal size. Based on our previous experimental observations and computational findings, we integrated our experimental measurements of patient biometrics along with mechanical characterization of the soft tissue into our numerical simulations to develop a series of computational models. These computational models can predict the required mechanical force for any potential patient where this can be advantageous in predicting an individual's tissue response to spring-mediated distraction enterogenesis and can be used toward a safe delivery of the mechanical force.
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Herein, for the first time, the adsorption mechanism of HCrO4- and CrO42- (as models of Cr(VI)) by bacterial cellulose (BC), polyaniline (PANI), and BC/PANI was performed using Density Functional Theory (DFT) in both acidic and neutral pH. For this purpose, three forms of neutral, partially (pp), and fully protonated (fp) were assumed for PANI in neutral and acidic media to elucidate the influence of pH. The results indicated that the formation of hydrogen bonds (H-bond) had the main contribution in the adsorption of CrO42- and HCrO4- onto both BC and PANI. Besides, the adsorption energy of PANI was nearly 3 times as much as BC in both acidic and neutral pH. The design of the BC/PANI complex improved the stability of PANI by increasing in HOMO-LUMO energy gap from 1.1 eV to 1.97 eV. The establishment of more H-bonds, and the appearance of two different types of H-bonds, Oâ¯H and Nâ¯H, and their smaller distances (average 1.5 Å), were observed in HCrO4-/BC-fp-PANI complexes, while one type of hydroxyl H-bond (average 2 Å) was detected in CrO42-/BC-pp-PANI. It proved the adsorption of Cr(VI) is more favorable in acidic pH. The small value of charge transferred (-0.001-0.01) showed that interfacial interaction was governed by physisorption.
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Compostos de Anilina/química , Celulose/química , Cromo/isolamento & purificação , Poluentes Químicos da Água/química , Adsorção/efeitos dos fármacos , Cromo/toxicidade , Simulação por Computador , Teoria da Densidade Funcional , Humanos , Águas Residuárias/química , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/métodosRESUMO
In this work, the structure-property relationship was evaluated in the synthesis of bacterial cellulose (BC)/polyaniline (PANI) nanocomposite aerogels in terms of both experimental and density functional theory (DFT) simulation. The molarity of HCl solution (0.01 and 0.5 M) and the presence/absence of cetyltrimethylammonium bromide (CTAB) were the main parameters of synthesis conditions. DFT simulation showed that the formation of hydrogen bonds governed interaction between BC and PANI, and PANI had more tendency to BC than that of CTAB at 0.5 M. It was confirmed by the formation of shorter hydrogen bonds between BC and protonated PANI at 0.5 M. Regarding this fact, prepared samples at 0.5 M of HCl solution and the presence of CTAB experienced higher storage modulus and electrical conductivity by 2000 Pa and 4 order of magnitude than those of lower molarity (0.01 M). These findings were in accordance with simulation outcomes.
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Compostos de Anilina/química , Bactérias/metabolismo , Celulose/química , Teoria da Densidade Funcional , Condutividade Elétrica , Nanocompostos/química , Tensoativos/química , Ligação de Hidrogênio , Polimerização , Propriedades de SuperfícieRESUMO
BACKGROUND: The methylation of the CpG islands of the LINE-1 promoter is a tight control mechanism on the function of mobile elements. However, simultaneous quantification of promoter methylation and transcription of LINE-1 has not been performed in progressive stages of colorectal cancer. In addition, the insertion of mobile elements in the genome of advanced adenoma stage, a precancerous stage before colorectal carcinoma has not been emphasized. In this study, we quantify promoter methylation and transcripts of LINE-1 in three stages of colorectal non-advanced adenoma, advanced adenoma, and adenocarcinoma. In addition, we analyze the insertion of LINE-1, Alu, and SVA elements in the genome of patient tumors with colorectal advanced adenomas. METHODS: LINE-1 hypomethylation status was evaluated by absolute quantitative analysis of methylated alleles (AQAMA) assay. To quantify the level of transcripts for LINE-1, quantitative RT-PCR was performed. To find mobile element insertions, the advanced adenoma tissue samples were subjected to whole genome sequencing and MELT analysis. RESULTS: We found that the LINE-1 promoter methylation in advanced adenoma and adenocarcinoma was significantly lower than that in non-advanced adenomas. Accordingly, the copy number of LINE-1 transcripts in advanced adenoma was significantly higher than that in non-advanced adenomas, and in adenocarcinomas was significantly higher than that in the advanced adenomas. Whole-genome sequencing analysis of colorectal advanced adenomas revealed that at this stage polymorphic insertions of LINE-1, Alu, and SVA comprise approximately 16%, 51%, and 74% of total insertions, respectively. CONCLUSIONS: Our correlative analysis showing a decreased methylation of LINE-1 promoter accompanied by the higher level of LINE-1 transcription, and polymorphic genomic insertions in advanced adenoma, suggests that the early and advanced polyp stages may host very important pathogenic processes concluding to cancer.