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1.
J Environ Manage ; 344: 118569, 2023 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-37453299

RESUMO

Electronegative Fluorine has great reactivity and it exists as organic or inorganic fluoride compounds. Biosorption feasibility of fluoride onto alginate-cellulose composites was investigated in this study. Extracted cellulose has been utilized to synthesize calcium alginate impregnated composite beads for fluoride remediation process in batch and fluidized-bed reactors. Physiochemical characteristics were analyzed by FTIR, SEM, TGA and BET. From the BET properties analysis, the surface area of prepared composite beads was 87.13 m2/g. The point zero charge (PZC) value of composite beads was attained at pH 7.32. The relationship between biosorption efficiency and independent variables have been observed to evaluate the effects on the fluoride biosorption efficiency of composites and its components. The hypothetical development of the removal technique has been explained using various nonlinear model-fitting methods to evaluate Isotherm study, bio-sorption Kinetics, Thermodynamic parameters and Mass transfer study. Maximum monolayer adsorption capacity (qm) obtained by following Langmuir model for fluoride removal was found to be 23.809 mg/g at 30 °C using adsorbent dosage of 2 g/L for an initial fluoride concentration of 6 mg/L. The optimized condition for fluoride adsorption experiment was observed by evaluating response surface methodology (RSM) was pH-5.67, dose 1.89 g/L and time 85.71 min and removal was found as 82.79%. Experimental data of fluidized-bed study were evaluated by designing mathematical modeling. Fluidization velocities was adjusted in between Umf and 2Umf for optimizing external mass transfer and adsorbent loss. Regeneration study of fluoride loaded biosorbent and cost analysis of composite production have been estimated.


Assuntos
Fluoretos , Poluentes Químicos da Água , Fluoretos/química , Alginatos , Concentração de Íons de Hidrogênio , Termodinâmica , Adsorção , Cinética , Celulose , Poluentes Químicos da Água/química
2.
Genomics ; 112(6): 4406-4416, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32717319

RESUMO

The existing model-independent methods for the detection of exons in DNA could not prove to be ideal as commonly employed fixed window length strategy produces spectral leakage causing signal noise The Modified-Gabor-wavelet-transform exploits a multiscale strategy to deal with the issue to some extent. Yet, no rule regarding the occurrence of small and large exons has been specified. To overcome this randomness, scaling-factor of GWT has been adapted based on a fuzzy rule. Due to the nucleotides' genetic code and fuzzy behaviors in DNA configuration, this work could adopt the fuzzy approach. Two fuzzy membership functions (large and small) take care of the variation in the coding regions. The fuzzy-based learning parameter adaptively tunes the scale factor for fast and precise prediction of exons. The proposed approach has an immense plus point of being capable of isolating detailed sub-regions in each exon efficiently proving its efficacy comparing with existing techniques.


Assuntos
Éxons , Análise de Sequência de DNA/métodos , Lógica Fuzzy , Análise de Ondaletas
3.
Genomics ; 111(3): 284-296, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30342085

RESUMO

Identification of exon location in a DNA sequence has been considered as the most demanding and challenging research topic in the field of Bioinformatics. This work proposes a robust approach combining the Trigonometric mapping with Adaptive tuned Kaiser Windowing approach for locating the protein coding regions (EXONS) in a genetic sequence. For better convergence as well as improved accurateness, the side lobe height control parameter (ß) of Kaiser Window in the proposed algorithm is made adaptive to track the changing dynamics of the genetic sequence. This yields better tracking potential of the anticipated Adaptive Kaiser algorithm as it uses the recursive Gauss Newton tuning which in turn utilizes the covariance of the error signal to tune the ß factor which has been shown through numerous simulation results under a variety of practical test conditions. A detailed comparative analysis with the existing mapping schemes, windowing techniques, and other signal processing methods like SVD, AN, DFT, STDFT, WT, and ST has also been included in the paper to focus on the strength and efficiency of the proposed approach. Moreover, some critical performance parameters have been computed using the proposed approach to investigate the effectiveness and robustness of the algorithm. In addition to this, the proposed approach has also been successfully applied on a number of benchmark gene sets like Musmusculus, Homosapiens, and C. elegans, etc., where the proposed approach revealed efficient prediction of exon location in contrast to the other existing mapping methods.


Assuntos
Algoritmos , Éxons , Genômica/métodos , Análise de Sequência de DNA/métodos , Animais , Genômica/normas , Humanos , Sensibilidade e Especificidade , Análise de Sequência de DNA/normas
4.
J Environ Manage ; 276: 111272, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-32871466

RESUMO

In this study, carbonized material was produced using sodium hydroxide treated Sugar cane bagasse (SB), and synthesized materials ware used to prepare Sodium Alginate/SBAC composite beads which were further used as an adsorbent to remove malachite green dye (MG) present in water. Physiochemical characteristics of composite beads were analyzed using FTIR, SEM, TGA, and BET. Adsorption equilibrium data showed excellent fit to the Freundlich model (R2 = 0.994) than to the Langmuir model (R2 = 0.925). Adsorption kinetics study indicated that the MG removal process would be better described by the pseudo-second-order kinetic model. The thermodynamic study suggested the spontaneous and endothermic nature of MG adsorption. By using response surface methodology, the optimum conditions for MG adsorption on composite beads were found to be 115.43 min, 0.3 g/L and pH 8 for contact time, adsorbent mass, and pH respectively and MG adsorption efficiency was 97.88%. The fixed-bed column data were evaluated using several kinetic models and among them, Thomas model showed the best agreement with investigation results. These results revealed that synthesized composite beads have a high affinity toward MG and it could be reasonable, eco-friendly adsorbent for dye removal from wastewater.


Assuntos
Saccharum , Poluentes Químicos da Água , Adsorção , Alginatos , Carvão Vegetal , Concentração de Íons de Hidrogênio , Cinética , Corantes de Rosanilina , Hidróxido de Sódio
5.
FASEB J ; 32(10): 5378-5389, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29688807

RESUMO

Gastric epithelial cells infected with Helicobacter pylori acquire highly invasive and metastatic characteristics. The seven in absentia homolog (Siah)2, an E3 ubiquitin ligase, is one of the major proteins that induces invasiveness of infected gastric epithelial cells. We find that p300-driven acetylation of Siah2 at lysine 139 residue stabilizes the molecule in infected cells, thereby substantially increasing its efficiency to degrade prolyl hydroxylase (PHD)3 in the gastric epithelium. This enhances the accumulation of an oncogenic transcription factor hypoxia-inducible factor 1α (Hif1α) in H. pylori-infected gastric cancer cells in normoxic condition and promotes invasiveness of infected cells. Increased acetylation of Siah2, Hif1α accumulation, and the absence of PHD3 in the infected human gastric metastatic cancer biopsy samples and in invasive murine gastric cancer tissues further confirm that the acetylated Siah2 (ac-Siah2)-Hif1α axis is crucial in promoting gastric cancer invasiveness. This study establishes the importance of a previously unrecognized function of ac-Siah2 in regulating invasiveness of H. pylori-infected gastric epithelial cells.-Kokate, S. B., Dixit, P., Das, L., Rath, S., Roy, A. D., Poirah, I., Chakraborty, D., Rout, N., Singh, S. P., Bhattacharyya, A. Acetylation-mediated Siah2 stabilization enhances PHD3 degradation in Helicobacter pylori-infected gastric epithelial cancer cells.


Assuntos
Células Epiteliais , Mucosa Gástrica , Infecções por Helicobacter , Helicobacter pylori , Prolina Dioxigenases do Fator Induzível por Hipóxia/metabolismo , Proteínas de Neoplasias/metabolismo , Proteínas Nucleares/metabolismo , Proteólise , Neoplasias Gástricas , Ubiquitina-Proteína Ligases/metabolismo , Acetilação , Linhagem Celular Tumoral , Estabilidade Enzimática , Células Epiteliais/enzimologia , Células Epiteliais/microbiologia , Células Epiteliais/patologia , Mucosa Gástrica/enzimologia , Mucosa Gástrica/microbiologia , Mucosa Gástrica/patologia , Infecções por Helicobacter/enzimologia , Infecções por Helicobacter/microbiologia , Infecções por Helicobacter/patologia , Humanos , Neoplasias Gástricas/enzimologia , Neoplasias Gástricas/microbiologia , Neoplasias Gástricas/patologia
6.
Biochem J ; 473(11): 1629-40, 2016 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-27048589

RESUMO

Helicobacter pylori infection is one of the most potent factors leading to gastric carcinogenesis. The seven in absentia homologue (Siah2) is an E3 ubiquitin ligase which has been implicated in various cancers but its role in H. pylori-mediated gastric carcinogenesis has not been established. We investigated the involvement of Siah2 in gastric cancer metastasis which was assessed by invasiveness and migration of H. pylori-infected gastric epithelial cancer cells. Cultured gastric cancer cells (GCCs) MKN45, AGS and Kato III showed significantly induced expression of Siah2, increased invasiveness and migration after being challenged with the pathogen. Siah2-expressing stable cells showed increased invasiveness and migration after H. pylori infection. Siah2 was transcriptionally activated by E26 transformation-specific sequence 2 (ETS2)- and Twist-related protein 1 (Twist1) induced in H. pylori-infected gastric epithelial cells. These transcription factors dose-dependently enhanced the aggressiveness of infected GCCs. Our data suggested that H. pylori-infected GCCs gained cell motility and invasiveness through Siah2 induction. As gastric cancer biopsy samples also showed highly induced expression of ETS2, Twist1 and Siah2 compared with noncancerous gastric tissue, we surmise that ETS2- and Twist1-mediated Siah2 up-regulation has potential diagnostic and prognostic significance and could be targeted for therapeutic purpose.


Assuntos
Infecções por Helicobacter/metabolismo , Proteínas Nucleares/metabolismo , Proteína Proto-Oncogênica c-ets-2/metabolismo , Neoplasias Gástricas/metabolismo , Proteína 1 Relacionada a Twist/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Linhagem Celular Tumoral , Células Epiteliais/metabolismo , Mucosa Gástrica/metabolismo , Helicobacter pylori/patogenicidade , Humanos , Técnicas In Vitro , Proteínas Nucleares/genética , Ligação Proteica , Proteína Proto-Oncogênica c-ets-2/genética , Neoplasias Gástricas/patologia , Proteína 1 Relacionada a Twist/genética , Ubiquitina-Proteína Ligases/genética
7.
Biochem Biophys Res Commun ; 471(1): 205-12, 2016 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-26826385

RESUMO

Hypoxia promotes cancer progression, and metastasis. The major protein expressed in hypoxic solid cancer is hypoxia-inducible factor 1 (HIF1). We show that enhanced phosphorylation of a conventional protein kinase C isoform, PKCα, at threonine 638 (T(638)) by hypoxia-mimetic cobalt chloride induces HIF1α in nuclei of gastric epithelial cells (GECs). Moreover, phospho-T(638)-PKCα (P-PKCα) interacts with p300-HIF1α complex in the nuclei of hypoxic GECs and PKCα phosphorylation at T(638) enhances transcriptional activity of HIF1α. High P-PKCα expression in neoplastic gastric cancer biopsy samples as compared to nonneoplastic samples suggests that P-PKCα might act as an indicator of gastric cancer progression.


Assuntos
Núcleo Celular/metabolismo , Cobalto/administração & dosagem , Mucosa Gástrica/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Proteína Quinase C-alfa/metabolismo , Hipóxia Celular/efeitos dos fármacos , Hipóxia Celular/fisiologia , Linhagem Celular , Núcleo Celular/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Mucosa Gástrica/efeitos dos fármacos , Humanos , Fosforilação/efeitos dos fármacos , Fosforilação/fisiologia
8.
FASEB J ; 29(3): 796-806, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25404713

RESUMO

Helicobacter pylori induces the antiapoptotic protein myeloid cell leukemia 1 (Mcl1) in human gastric epithelial cells (GECs). Apoptosis of oncogenic protein Mcl1-expressing cells is mainly regulated by Noxa-mediated degradation of Mcl1. We wanted to elucidate the status of Noxa in H. pylori-infected GECs. For this, various GECs such as AGS, MKN45, and KATO III were either infected with H. pylori or left uninfected. The effect of infection was examined by immunoblotting, immunoprecipitation, chromatin immunoprecipitation assay, in vitro binding assay, flow cytometry, and confocal microscopy. Infected GECs, surgical samples collected from patients with gastric adenocarcinoma as well as biopsy samples from patients infected with H. pylori showed significant up-regulation of both Mcl1 and Noxa compared with noninfected samples. Coexistence of Mcl1 and Noxa was indicative of an impaired Mcl-Noxa interaction. We proved that Noxa was phosphorylated at Ser(13) residue by JNK in infected GECs, which caused cytoplasmic retention of Noxa. JNK inhibition enhanced Mcl1-Noxa interaction in the mitochondrial fraction of infected cells, whereas overexpression of nonphosphorylatable Noxa resulted in enhanced mitochondria-mediated apoptosis in the infected epithelium. Because phosphorylation-dephosphorylation can regulate the apoptotic function of Noxa, this could be a potential target molecule for future treatment approaches for H. pylori-induced gastric cancer.


Assuntos
Apoptose , Células Epiteliais/patologia , Infecções por Helicobacter/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Neoplasias Gástricas/patologia , Estômago/patologia , Adenocarcinoma/metabolismo , Adenocarcinoma/patologia , Adenocarcinoma/virologia , Western Blotting , Diferenciação Celular , Proliferação de Células , Células Cultivadas , Imunoprecipitação da Cromatina , Células Epiteliais/metabolismo , Células Epiteliais/virologia , Citometria de Fluxo , Mucosa Gástrica/metabolismo , Infecções por Helicobacter/patologia , Infecções por Helicobacter/virologia , Helicobacter pylori/fisiologia , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/antagonistas & inibidores , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Técnicas Imunoenzimáticas , Imunoprecipitação , MAP Quinase Quinase 4 , Mitocôndrias , Proteína de Sequência 1 de Leucemia de Células Mieloides/genética , Proteína de Sequência 1 de Leucemia de Células Mieloides/metabolismo , Fosforilação , Proteínas Proto-Oncogênicas c-bcl-2/genética , RNA Mensageiro/genética , RNA Interferente Pequeno/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais , Estômago/virologia , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/virologia
9.
Toxicol Int ; 22(1): 83-91, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26862266

RESUMO

OBJECTIVE: Improved understanding of cytotoxicity under chemical assaults may be achieved by multimodal analysis of cellular morphology, viability, molecular expressions, and biophysical properties. MATERIALS AND METHODS: In this study dose-dependent effects of an organic solvent (OS), iso-octane (IO), known to cause skin irritation, has been explored multimodally for understanding its effect on structural and functional profile of normal epithelial cell population in vitro. RESULTS: Under IO exposures, after 5 h there was a sharp decrease in viability of HaCaT with increasing doses which may be due to disruption in cellular association noted via immunocytochemical study and was further supported by the decreased expression of E-cadherin at transcriptomic level. Dislocation of E-cadherin from membrane to the cytoplasm occurred with increasing doses. The dose-dependent changes in varied aspects of bioelectrical properties, having plausible correlation with cellular viability, association, and adherence were noteworthy at 5 h of IO exposure. Evaluation of biomechanical properties by micropipette aspiration showed a distinct change in cellular stiffness in terms of increase in suction force and post-suction alteration in cellular shape. The cells became stiffer and fragile with increasing IO doses. CONCLUSION: Present study explicated dose-dependent cytotoxicity of IO on HaCaT and explored the usefulness of this approach to develop in vitro model system to evaluate epithelial toxicity with level-free markers.

10.
ACS Appl Bio Mater ; 2024 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-38581392

RESUMO

Carbon dots (CDs) have recently emerged in biomedical and agricultural domains, mainly for their probe applications in developing efficient sensors. However, the existing high-temperature approaches limit the industrial level scaling up to further translate them into different products by mass-scale fabrication of CDs. To address this, we have attempted to lower the synthesis temperature to 140 °C and synthesized different CDs using different organic acids and their combinations in a one-step approach (quantum yield 3.6% to 16.5%; average size 3 to 5 nm). Further, sensing applications of CDs have been explored in three different biological models, mainly Danio rerio (zebrafish) embryos, bacterial strains, and the Lactuca sativa (lettuce) plant. The 72 h exposure of D. rerio embryos to 0.5 and 1 mg/mL concentrations of CDs exhibited significant uptake without mortality, a 100% hatching rate, and nonsignificant alterations in heart rate. Bacterial bioimaging experiments revealed CD compatibility with Gram-positive (Bacillus subtilis) and Gram-negative (Serratia marcescens) strains without bactericidal effects. Furthermore, CDs demonstrated effective conduction and fluorescence within the vascular system of lettuce plants, indicating their potential as in vivo probes for plant tissues. The single-step low-temperature CD synthesis approach with efficient structural and optical properties enables the process as industrially viable to up-scale the technology readiness level. The bioimaging of CDs in different biological models indicates the possibility of developing a CD probe for diverse biosensing roles in diseases, metabolism, microbial contamination sensing, and more.

11.
Tissue Eng Part C Methods ; 29(6): 242-256, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37171125

RESUMO

Wound healing (WH) is a complex and dynamic process that comprises of a series of molecular and cellular events that occur after tissue injury. The injuries of the maxillofacial and oral region caused by trauma or surgery result in undesirable WH such as delayed wound closure and formation of scar tissue. Skin tissue engineering (TE)/regeneration is an emerging approach toward faster, superior, and more effective resolution of clinically significant wounds effectively. A multitude of TE principles approaches are being put to action for the fabrication of hydrogels, electrospun sheets, 3D scaffolds, and thin films that can be used as wound dressings materials, sutures, or skin substitutes. Thin films are advantageous over other materials owing to their flexibility, ability to provide a barrier against external contamination, easy gaseous exchange, and easy monitoring of wounds. This review focuses on wound-dressing films and their significance and discusses various fabrication techniques. In addition, we explore various natural biopolymers that can be used for fabrication of skin TE materials. Impact Statement In this review article, critical evaluations of natural polymers used in skin regeneration were discussed. Further, the fabrication technology of the 2D and 3D material in wound healing were discussed.


Assuntos
Polímeros , Regeneração , Pele , Cicatrização , Odontologia
12.
Int J Biol Macromol ; 253(Pt 1): 126683, 2023 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-37666396

RESUMO

Parkinson's disease (PD) is linked to α-synuclein (aS) aggregation and deposition of amyloid in the substantia nigra region of the brain tissues. In the current investigation we produced two distinct classes of aS oligomer of differed protein conformation, stability and compared their toxic nature to cultured neuronal cells. Lyophilized oligomer (LO) was produced in storage of aS at-20 °C for 7 days and it was enriched with loosely hold molten globule like structure with residues having preferences for α-helical conformational space. The size of the oligomer was 4-5.5 nm under AFM. This kind of oligomer exhibited potential toxicity towards neuronal cell lines and did not transform into compact ß-sheet rich amyloid fiber even after incubation at 37 °C for several days. Formation of another type of oligomer was often observed in the lag phase of aS fibrillation that often occurred at an elevated temperature (37 °C). This kind of heat induced oligomer (IO) was more hydrophobic and relatively less toxic to neuronal cells compared to lyophilized oligomer (LO). Importantly, initiation of hydrophobic zipping of aS caused the transformation of IO into thermodynamically stable ß-sheet rich amyloid fibril. On the other hand, the presence of molten globule like conformation in LO, rendered greater toxicity to cultured neuronal cells.


Assuntos
Doença de Parkinson , alfa-Sinucleína , Humanos , alfa-Sinucleína/química , Doença de Parkinson/metabolismo , Conformação Proteica , Neurônios/metabolismo , Conformação Proteica em Folha beta , Amiloide/química , Proteínas Amiloidogênicas
13.
Methods Mol Biol ; 2589: 317-335, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36255634

RESUMO

Helicobacter pylori infection is one of the leading factors that promotes, among other diseases, gastric cancer (GC). Infection of gastric epithelial cells (GECs) by H. pylori enhances the expression as well as acetylation of the E3 ubiquitin ligase SIAH2 which promotes GC progression. The histone acetyltransferase (HAT) activity of p300 catalyzes SIAH2 acetylation following H. pylori infection. Since reactive oxygen species (ROS) generation in H. pylori-infected GECs accelerates GC progression, acetylation-mediated SIAH2 regulation might be a crucial modifier of ROS generation in the infected GECs. Here, we describe a compendium of methods to evaluate the effects of HAT/lysine acetyl transferase (KAT) inhibitors (HAT/KATi) on SIAH2-mediated ROS regulation in H. pylori-infected GECs.


Assuntos
Infecções por Helicobacter , Helicobacter pylori , Neoplasias Gástricas , Humanos , Helicobacter pylori/metabolismo , Infecções por Helicobacter/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Mucosa Gástrica/metabolismo , Lisina/metabolismo , Células Epiteliais/metabolismo , Neoplasias Gástricas/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Histona Acetiltransferases/metabolismo , Transferases/metabolismo
14.
Front Chem ; 11: 1145877, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37304685

RESUMO

Parkinson's disease is an age-related neurological disorder, and the pathology of the disease is linked to different types of aggregates of α-synuclein or alpha-synuclein (aS), which is an intrinsically disordered protein. The C-terminal domain (residues 96-140) of the protein is highly fluctuating and possesses random/disordered coil conformation. Thus, the region plays a significant role in the protein's solubility and stability by an interaction with other parts of the protein. In the current investigation, we examined the structure and aggregation behavior of two artificial single point mutations at a C-terminal residue at position 129 that represent a serine residue in the wild-type human aS (wt aS). Circular Dichroism (CD) and Raman spectroscopy were performed to analyse the secondary structure of the mutated proteins and compare it to the wt aS. Thioflavin T assay and atomic force microscopy imaging helped in understanding the aggregation kinetics and type of aggregates formed. Finally, the cytotoxicity assay gave an idea about the toxicity of the aggregates formed at different stages of incubation due to mutations. Compared to wt aS, the mutants S129A and S129W imparted structural stability and showed enhanced propensity toward the α-helical secondary structure. CD analysis showed proclivity of the mutant proteins toward α-helical conformation. The enhancement of α-helical propensity lengthened the lag phase of fibril formation. The growth rate of ß-sheet-rich fibrillation was also reduced. Cytotoxicity tests on SH-SY5Y neuronal cell lines established that the S129A and S129W mutants and their aggregates were potentially less toxic than wt aS. The average survivability rate was ∼40% for cells treated with oligomers (presumably formed after 24 h of incubation of the freshly prepared monomeric protein solution) produced from wt aS and ∼80% for cells treated with oligomers obtained from mutant proteins. The relative structural stability with α-helical propensity of the mutants could be a plausible reason for their slow rate of oligomerization and fibrillation, and this was also the possible reason for reduced toxicity to neuronal cells.

15.
ACS Appl Mater Interfaces ; 15(22): 27243-27252, 2023 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-37218678

RESUMO

The search for safe, reliable, and compact high-capacity energy storage devices has led to increased interest in all-solid-state battery research. The use of solid electrolytes provides enhanced safety and durability due to their reduced flammability and increased mechanical strength compared to organic liquid electrolytes. Still, the use of solid electrolytes remains challenging. A significant issue is their generally low Li-ion conductivity, which depends on the lattice diffusion of Li ions through the solid phase, as well as on the limited contact area between the electrolyte particles. While the lattice diffusion can be addressed through the chemistry of the solid electrolyte material, the contact area is a mechanical and structural problem of packing and compression of the electrolyte particles depending on their size and shape. This work studies the effect of pressurization on the electrolyte conductivity exploring cases of low as well as high grain boundary (GB) conductivity, compared to the bulk conductivity. Scaling dependence, σ ∼ Pη, of the conductivity σ with pressure P is revealed. For an idealized electrolyte represented as spheres in hexagonal closely packed configuration, η = 2/3 and η = 1/3 have been theoretically calculated for the two cases of low and high GB conductivity, respectively. For randomly packed spheres, the equivalent exponent values were numerically estimated to be approximately 3/4 and 1/2, respectively, which are higher than the closed packed values due to the additional decrease of porosity with the increase in pressure. As demonstrated in the study, experimental measurement of η can indicate which type of bulk or GB conductivity is dominant in a particular electrolyte powder and could be used in addition to electrochemical impedance spectroscopy measurements.

16.
Nanotechnology ; 22(3): 035703, 2011 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-21149956

RESUMO

We show that nanoporous anodic alumina films, with pore diameters in the range 10-80 nm, can be transformed from being very hydrophilic (or super-hydrophilic) to very hydrophobic (or super-hydrophobic) by coating the surface with a thin (2-3 nm) layer of a hydrophobic polymer. This dramatic transformation happens as a result of the interplay between surface morphology and surface chemistry. The coated surfaces exhibit 'sticky' hydrophobicity as a result of ingress of water into the pores by capillary action. The wetting parameters (contact angle and contact angle hysteresis) exhibit qualitatively different dependences on pore diameters in coated and uncoated films, which are explained by invoking appropriate models for wetting.

17.
Pediatr Emerg Care ; 27(2): 151-6, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21293228

RESUMO

OBJECTIVE: Eye burns can cause significant ocular morbidity and miss early detection if unsuspected. The objective was to ascertain the reported causes of burns to the eyes in children. METHODS: Published literature on eye burns in children was searched from 1950 to July 2008 in MEDLINE and from 1982 to July 2008 in CINAHL (Cumulative Index to Nursing and Allied Health Literature) to identify all reported cases. RESULTS: Forty-two articles from MEDLINE, 5 from CINAHL database, and 6 from the reference lists were included in the analysis. Eye burns in children were caused by thermal, electrical, microwaved food and drinks, and solar hazards. Chemical agents included household cleaning agents, industrial chemicals, certain medications, agricultural chemicals, and some miscellaneous agents. Biological agents reported were millipedes, snake venom, vesicatory insects, and Manchineel tree sap. CONCLUSIONS: This article shows that children experience eye burns due to many preventable causes. Public education strategies should be implemented to prevent eye burns in children.


Assuntos
Queimaduras Oculares/induzido quimicamente , Queimaduras Oculares/epidemiologia , Prevenção Primária/métodos , Queimaduras Químicas/epidemiologia , Queimaduras Químicas/prevenção & controle , Queimaduras Químicas/terapia , Criança , Pré-Escolar , Cosméticos/efeitos adversos , Detergentes/efeitos adversos , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Serviço Hospitalar de Emergência , Queimaduras Oculares/prevenção & controle , Queimaduras Oculares/terapia , Feminino , Seguimentos , Substâncias Perigosas/efeitos adversos , Produtos Domésticos/efeitos adversos , Humanos , Incidência , Masculino , Medição de Risco , Índice de Gravidade de Doença
18.
Environ Sci Pollut Res Int ; 28(34): 47107-47125, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33886051

RESUMO

The present investigation attempted to examine the defluoridation feasibility onto the extracted nanocellulose/PVA polymer composites. Nanocellulose were derived from sugarcane bagasse and blended with PVA (polyvinyl alcohol) polymer matrix. The defluoridation potential of nanocellulose/PVA was observed to be significantly dependent on the various operational factors including pH, time interval, etc. the Temkin isotherm (R2 = 0.989) as well as the Langmuir isotherm equation (R2 = 0.982) could well fit with the investigational data. Following the Langmuir isotherm, the maximum monolayer adsorption capacity for fluoride elimination at 25°C was obtained as 11.363 mg g-1. The nature of rate-limiting steps involved in defluoridation process might be effectively predicted by pseudo-second-order kinetics. Values of thermodynamic state properties achieved as of the thermodynamic analysis showed that the defluoridation process was spontaneous, exothermic, and feasible. The diffusion and mass transfer study were estimated by following the Boyd's model. Average effective diffusion coefficient (De) at various initial fluoride concentrations (4-10 mg L-1) was obtained as 15.3343×10-7 m2s-1 and the estimated magnitude of the mass-transfer coefficient (Kf) was 0.0346×10-9 m s-1 (temperature = 298 K, C0= 6 mgL-1). An ANN (artificial neural network) model applied to optimize and simulate the defluoridation procedure. Furthermore, continuous flow column reactor was conducted to investigate the practical applicability of composites in the defluoridation process. The Yoon-Nelson and the Thomas model exhibited excellent conformity with the breakthrough curves. Nanocellulose/PVA satisfactorily eliminated fluoride from its aqueous solution and can be considered as a suitable bio-sorbent for defluoridation.


Assuntos
Poluentes Químicos da Água , Purificação da Água , Adsorção , Fluoretos , Concentração de Íons de Hidrogênio , Cinética , Álcool de Polivinil , Termodinâmica , Poluentes Químicos da Água/análise
19.
Nucleosides Nucleotides Nucleic Acids ; 40(10): 985-1017, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34455915

RESUMO

Bioinformatics in the present day has been firmly established as a regulator in genomics. In recent times, applications of Signal processing in exon prediction have gained a lot of attention. The exons carry protein information. Proteins are composed of connected constituents known as amino acids that characterize the specific function. Conversion of the nucleotide character string into a numerical sequence is the gateway before analyzing it through signal processing methods. This numeric encoding is the mathematical descriptor of nucleotides and is based on some statistical properties of the structure of nucleic acids. Since the type of encoding extremely affects the exon detection accuracy, this paper is devised for the review of existing encoding (mapping) schemes. The comparative analysis is formulated to emphasize the importance of the genetic code setting of amino acids considered for application related to computational elucidation for exon detection. This work covers much helpful information for future applications.


Assuntos
Biologia Computacional , DNA/genética , Análise de Sequência de DNA , Aminoácidos/genética , Sequência de Bases , Humanos
20.
J Pharm Bioallied Sci ; 13(Suppl 2): S1088-S1092, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35017935

RESUMO

BACKGROUND: Nyctanthes arbor-tristis (NAT) is an ornamental garden plant traditionally used for treating many diseases such as helminthiasis, arthritis, and malaria. AIMS: The aim of this study was to validate the ethnobotanical uses of the antimalarial activity of leaves of NAT by in vivo tests. MATERIALS AND METHODS: Leaves of NAT were identified and authenticated and phytoconstituents of NAT were identified. The antimalarial activity of NAT was studied in in vivo for its schizonticidal activity, repository activity, and curative tests in Swiss albino mice by using Plasmodium berghei (ANKA). STATISTICAL ANALYSIS USED: One-way ANOVA was done for comparison of different groups followed by post hoc analysis (Tukey-Kramer multiple comparison tests). Level of significance was at P < 0.05. RESULTS: The mean schizonticidal activity of NAT increased from 14.21 to 46.15 (P < 0.01) with doses ranging from 100 to 200 mg/kg compared to 67.29 with that of chloroquine (CQ). The repository activity with NAT doses 100-200 mg/kg increased from 12.91 to 42.85 (P < 0.01) compared to 78.79 in pyrimethamine 1.2 mg/kg/day. In Rane's test, there was chemosuppression in range of 55.50-65.02 (P < 0.01) with NAT in doses of 100-200 mg/kg compared to 74.15 with that of CQ 5 mg/kg. CONCLUSIONS: The antiplasmodial activity of NAT might be like that of artemisinin by producing oxidative stress mostly due to the iridoid glycosides. The active phytoconstituent(s) responsible may be tested individually or in combination both by in vitro and in vivo studies to identify the active chemical ingredient.

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