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1.
Ann Med Surg (Lond) ; 86(5): 2562-2571, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38694302

RESUMO

Background: Increased COVID-19 transmission among the populace may be caused by healthcare workers (HCWs) who lack knowledge, awareness, and good preventive practices. Additionally, it may cause elevated stress levels, anxiety, poor medical judgement, and situational overestimation. Objectives: The present survey aimed to assess knowledge and risk perception regarding COVID-19 among HCWs in Khyber Pakhtunkhwa (KP), Pakistan. Methodology: A web-based online, pre-tested questionnaire comprising 26 items was circulated via social media in April 2020 amongst HCWs in major tertiary care facilities in KP. Results: The study's results, revealing both the commendable knowledge levels among HCWs about COVID-19 and their heightened risk perception, highlight the critical need for targeted interventions to address the potential impact on self-protective behaviour and mental health within this vital workforce. This insight is important for designing strategies that not only enhance HCWs' well-being but also ensure the continued effectiveness of healthcare delivery during pandemics. The percentage mean score (PMS) of COVID-19 knowledge was 85.14±10.82. Male HCWs and those with an age older than or equal to 32 years demonstrated a higher knowledge score (85.62±11.08; P=0.032 and 87.59±7.33, P=0.021, respectively). About 76% of HCWs feared contracting COVID-19. Nearly 82% of respondents were mentally preoccupied with the pandemic and also terrified of it. 'Of these, 81% were nurses, 87% had a job experience of 6-8 years and 54.45% were frontline workers. Feelings of panic and concern about the pandemic were found to be more in HCWs who were physicians above the age of 32, and who had 3-5 years of work experience. HCWs' overall risk perception was found to be significantly different between males (7.04±2.26) and females (8.01±1.97), job experience of 6-10 years (8.04±177) with 3-5 years and younger than or equal to 2 years job experience (7.18±2.43,6.93±2.22), respectively, and between frontline HCWs (7.50±2.10) and non-frontline HCWs (6.84±2.40). Conclusion: HCWs demonstrated good knowledge about COVID-19. As the risk perception of COVID-19 among HCWs is high, it can raise concerns about their self-protective behaviour, and mental health. These issues need to be addressed.

2.
Chem Asian J ; : e202400245, 2024 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-38634677

RESUMO

A highly flexible, tunable morphology membrane with excellent thermal stability and ionic conductivity can endow lithium metal batteries with high power density and reduced dendrite growth. Herein, a porous Polyurethane (PU) membrane with an adjustable morphology was prepared by a simple nonsolvent-induced phase separation technique. The precise control of the final morphology of PU membranes can be achieved through appropriate selection of a nonsolvent, resulting a range of pore structures that vary from finger-like voids to sponge-like pores. The implementation of combinatorial DFT and experimental analysis has revealed that spongy PU porous membranes, especially PU-EtOH, show superior electrolyte wettability (472%), high porosity (75%), good mechanical flexibility, robust thermal dimensional stability (above 170 °C), and elevated ionic conductivity (1.38 mS cm-1) in comparison to the polypropylene (PP) separator. The use of PU-EtOH in Li//Li symmetric cell results in a prolonged lifespan of 800 h, surpasing the longevity of PU or PP cells. Moreover, when subjected to a high rate of 5 C, the LiFePO4/Li half-cell with a PU-EtOH porous membrane displayed better cycling performance (115.4 mAh g-1) compared to the PP separator (104.4 mAh g-1). Finally, the prepared PU porous membrane exhibits significant potential for improving the efficiency and safety of LMBs.

3.
Chem Rec ; 24(4): e202300352, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38501854

RESUMO

Recently, carbon neutrality has been promoted as a potentially practical solution to global CO2 emissions and increasing energy-consumption challenges. Many attempts have been made to remove CO2 from the environment to address climate change and rising sea levels owing to anthropogenic CO2 emissions. Herein, membrane technology is proposed as a suitable solution for carbon neutrality. This review aims to comprehensively evaluate the currently available scientific research on membranes for carbon capture, focusing on innovative microporous material membranes used for CO2 separation and considering their material, chemical, and physical characteristics and permeability factors. Membranes from such materials comprise metal-organic frameworks, zeolites, silica, porous organic frameworks, and microporous polymers. The critical obstacles related to membrane design, growth, and CO2 capture and usage processes are summarized to establish novel membranes and strategies and accelerate their scaleup.

4.
Mini Rev Med Chem ; 2024 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-38185891

RESUMO

BACKGROUND: Heterocyclic compounds and their derivatives play a significant role in the design and development of novel quinoline drugs. Among the various pharmacologically active heterocyclic compounds, quinolines stand out as the most significant rings due to their broad pharmacological roles, specifically antitubercular activity, and their presence in plant-based compounds. Quinoline is characterized by a benzene ring fused to a pyridine ring, with both rings sharing two adjacent carbon atoms. Other names, such as benzpyridine, benzopyridine, and 1-azanaphthalene also know it. The importance of quinoline lies in its incorporation as a key component in various natural compounds found in medicinal plant families like Fumariaceae, Berberidaceae, Rutaceae, Papavaraceae, and others. OBJECTIVE: This article is expected to have a significant impact on the advancement of effective antitubercular medications. Through harnessing the potent activity of quinoline derivatives, the research aims to make valuable contributions to combating tuberculosis more efficiently and ultimately reducing the global burden of this infectious disease. METHODS: Numerous nitrogen-containing heterocyclic compounds exhibit significant potential as antitubercular agents. These chemicals have fused aromatic nitrogen-heterocyclic nuclei that can change the number of electrons they have, which can change their chemical, physical, and biological properties. This versatility arises from their ability to bind to receptors in multiple modes, a critical aspect of drug pharmacological screening. Among these compounds, quinoline stands out as it incorporates a stable fusion of a benzene ring with a pyridine nucleus. Quinolines have demonstrated a diverse range of pharmacological activities, including but not limited to anti-tubercular, antitumor, anticoagulant, anti-inflammatory, antioxidant, antiviral, antimalarial, anti-HIV, and antimicrobial effects. RESULTS: Some molecules, such as lone-paired nitrogen species, include pyrrole, pyrazole, and quinoline. These molecules contain oxygen and take part in metabolic reactions with other molecules inside the cell. However, an excessive accumulation of reactive nitrogen species can lead to cytotoxicity, resulting in damage to essential biological macromolecules. Among these compounds, quinoline stands out as the oldest and most effective one, exhibiting a wide range of beneficial properties such as antitubercular, antimicrobial, anti-inflammatory, antioxidant, analgesic, and anticonvulsant activities. Notably, naturally occurring quinoline compounds, such as quinine, have proven to be potent antimalarial drugs. CONCLUSION: This review highlights quinoline derivatives' antitubercular potential, emphasizing recent research advancements. Utilizing IC50 values, the study underscores the efficacy of various quinoline substitutions, hybrids, and electron-withdrawing groups against MTB H37Rv. Continued research is essential for developing potent, low-toxicity quinoline derivatives to combat tuberculosis.

5.
Int J Food Microbiol ; 410: 110508, 2024 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-38029662

RESUMO

Aflatoxin is a group I carcinogen and causes significant public health and food safety risks, throughout the world. This study was carried out to assess the levels of aflatoxin contamination in diseased peach (Prunus persica L.) fruit and their control using myco-synthesized iron oxide nanoparticles (Fe2O3 NPs). Diseased peach fruit were diagnosed to be infected with Aspergillus flavus. The isolated pathogen was cultured under UV light (365 nm) and exposed to ammonium hydroxide (31 %) vapors, which confirmed its ability to produce aflatoxin. For the control of this disease, Fe2O3 NPs were synthesized in the filtrate of a biocontrol fungus (Trichoderma harzianum) and characterized before analyzing their potential in disease control. FTIR spectrum described the presence of capping and reducing agents (secondary amines, alcohol, alkyne and aromatic compounds) on the surface of Fe2O3 NPs. X-ray Diffraction (XRD) described the crystalline size (7.78), while the spherical shape of Fe2O3 NPs was described by the SEM analysis. The EDX spectrum indicated the successful formation of Fe2O3 NPs by showing strong signals of iron (74.38 %). All concentrations displayed mycelial growth inhibition, in vitro and the greatest growth reduction (65.4 %) was observed at 1 mg/ml concentration of NPs. At the same concentration of Fe2O3 NPs, significant control of fruit rot of peach was also observed, in vivo. Treatment of Fe2O3 NPs maintained higher soluble solids, sucrose, total sugar, ascorbic acid, titratable acidity and firmness of peach fruit. Diseased fruit were further investigated for the presence and detection of aflatoxins. All three methods viz. thin layer chromatography (TLC), enzyme-linked immunosorbent assay (ELISA) and high-performance liquid chromatography (HPLC) confirmed a higher production of aflatoxins in control plants, while this production was significantly reduced in Fe2O3 NPs-treated peach fruit.


Assuntos
Aflatoxinas , Nanopartículas , Prunus persica , Aflatoxinas/análise , Frutas/química , Aspergillus flavus , Nanopartículas/química
6.
Chem Rec ; 24(1): e202300268, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37874033

RESUMO

Aluminum-sulfur batteries (AlSBs) exhibit significant potential as energy storage systems due to their notable attributes, including a high energy density, cost-effectiveness, and abundant availability of aluminum and sulfur. In order to commercialize AlSBs, an understanding of their working principles is necessary. In this review, we examine the current advancements in cathodes, both in theory and practice, as well as the progress made in aqueous and nonaqueous electrolytes. We also explore the modifications made to separators and the theoretical understanding of problems associated with AlSBs. Furthermore, we discuss future research directions aimed at resolving these issues. Our aim is to summarize the current progress in AlSBs and, based on recent progress and understanding of the mechanism, help design a battery to overcome the challenges that such batteries have been facing.

7.
Comput Biol Chem ; 108: 108003, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38159453

RESUMO

CDK9 is an emerging target for the development of anticancer drugs. The development of CDK9 inhibitors with significant potency had consistently posed a formidable challenge. In the current research, a number of computational methodologies, such as, 3D-QSAR, molecular docking, fingerprint analysis, molecular dynamic (MD) simulations followed by MMGB/PBSA and ADMET studies were used systemically to uncover the binding mechanism of pyrimidine derivatives against CDK9. The CoMFA and CoMSIA models having high q2 (0.53, 0.54) and r2 values (0.96, 0.93) respectively indicating that model could accurately predict the bioactivities of CDK9 inhibitors. Using the R-group exploration technique implemented by the Spark™ by Cresset group, the structural requirements revealed by the contour maps of model were utilized strategically to create an in-house library of 100 new CDK9 inhibitors. Additionally, the compounds from the in-house library were mapped into 3D-QSAR model which predicted pIC50 values comparable to the experimental values. A comparison between 3D-QSAR generated contours and molecular docking conformation of ligands was performed to elucidate the essentials of CDK9 inhibitor design. MD simulations (100 ns) were performed on the selected docked complexes A21, A14 and D98 which contributed in validating the binding interactions. According to the findings of binding free energy analysis (MMGB/PBSA), It was observed that residues CYS106 and GLU107 had a considerable tendency to facilitate ligand-protein interactions via H-bond interactions. The aforementioned findings have the potential to enhance researchers comprehension of the mechanism underlying CDK9 inhibition and may be utilized in the development of innovative and efficacious CDK9 inhibitors.


Assuntos
Simulação de Dinâmica Molecular , Relação Quantitativa Estrutura-Atividade , Simulação de Acoplamento Molecular , Ligação Proteica , Pirimidinas/farmacologia
8.
Small ; : e2309918, 2023 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-38084467

RESUMO

Anode materials with high-rate performances and good electrochemical stabilities are urgently required for the grid-scale application of lithium-ion batteries (LIBs). Theoretically, transition metal borides are desirable candidates because of their appropriate working potentials and good conductivities. However, the reported metal borides exhibit poor performances owing to their lack of favorable Li+ storage sites and poor structural stabilities during long-term charging/discharging. In this work, a ternary alkali metal boride, Li1.2 Ni2.5 B2 , which displays a high Li+ storage capacity and remarkable electrochemical stability and an excellent rate performance is studied. In contrast to conventional transition metal borides, the introduction of Li atoms facilitates the formation of 1D Ni/B-based honeycomb channels during synthesis. This Ni/B framework successfully sustains the strain during Li+ intercalation and deintercalation, and thus, the optimized Li1.2 Ni2.5 B2 anode exhibits an excellent cycle stability over 500 charge/discharge cycles. This electrode also exhibits superior reversible capacities of 350, 183, and 80 mA h g-1 at 0.1, 1, and 5 A g-1 , respectively, indicating the considerable potential of the 1D Ni/B framework as a commercially available fast-charging LIB anode.

9.
Mol Neurobiol ; 60(10): 5891-5901, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37357229

RESUMO

Alzheimer's disease (AD) is the most common form of dementia, generally affecting elderly people in the age group of above 60-65 years. Amyloid deposition has been found to be a possible cause and a characteristic feature of Alzheimer's disease. Mutations, variant genotypes, or downregulation that reduce amyloid clearance or accelerate amyloid accumulation can lead to Alzheimer's disease. This study involved clinically confirmed AD patients, age matched controls of similar ethnicity, and patients who had no history of cancer or any other chronic disease. DNA and RNA extractions of samples were done as per Saguna et al. [45] and TRIzol method, respectively. Frequencies of variant genotypes were observed using the RFLP technique, whereas, for expression analysis, qPCR was performed. The association between diet, smoking status, family history, and co-morbidities was calculated using statistical tools. Expression analysis showed downregulation in more than 65% of AD cases. Hypertension and diabetes also had a significant association with AD. Allelic isoforms ε2:ε2 and ε2:ε3 tend to be less frequent among AD cases compared to controls (2.85% vs 26.15% and 11.42% vs 21.43%, respectively). Among individuals (AD cases) with ε2:ε3 and ε2:ε4, 37.5% of the patients were having severe dementia and 62.5% were having mild to moderate dementia, whereas, among individuals with ε3:ε4 and ε4:ε4, 57% were having severe dementia and 43% were having mild to moderate dementia. Besides this, all early-onset Alzheimer's patients were found to have at least one ε4 allele. The percentage of individuals with family history (cases vs controls) was 34.17% vs 3.75%, without family history 64.55% vs 95%. On comparing AD cases against controls for smoking status, the results observed are the following: chain smokers, 12.65% vs 18.75%; moderate smokers, 16.45% vs 6.25%; ex-smokers, 36.70% vs 22.50%; non-smokers, 34.17% vs 52.50%. On comparing dietary habits in AD cases against controls, the results were as follows: individuals with generally fatty diet 26.58% vs 11.25%, with mixed diet 36.70% vs 78.75%, with generally vegetarian diet 34.17% vs 10.00%, data not available 2.53% among AD cases. Family history, dietary habits, genetics, and socioeconomic status are strongly associated with the development of Alzheimer disease. Although family history or genetic makeup cannot be changed, eating habits can be changed quite easily. We simply need to go from a high-fat diet to one that is lower in fat. Regarding socioeconomic status, which includes stress of both kinds, including economic stress, stress brought on by the loss of loved ones through death or separation, and co-morbidities (hypertension and diabetes), all are manageable and even modifiable through counseling, positive behavior, and physical activity like exercise, walking, cycling, and playing games.


Assuntos
Doença de Alzheimer , Demência , Hipertensão , Idoso , Humanos , Pessoa de Meia-Idade , Alelos , Doença de Alzheimer/epidemiologia , Doença de Alzheimer/genética , Apolipoproteína E4/genética , Apolipoproteínas E/genética , Estudos de Casos e Controles , Demência/genética , Dieta , Regulação para Baixo/genética , Genótipo , Hipertensão/epidemiologia , Hipertensão/genética , Morbidade , Isolamento Social , Transcriptoma
10.
ACS Appl Mater Interfaces ; 14(47): 52794-52805, 2022 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-36394388

RESUMO

Lithium-sulfur (Li-S) batteries are one of the emerging candidates for energy storage systems due to their high theoretical energy density and the abundance/nontoxicity/low cost of sulfur. Compared with conventional lithium-ion batteries, multiple new challenges have been brought into this advanced battery system, such as polysulfide shuttling in conventional polyolefin separators and undesired lithium dendrite formation of the Li metal anode. These issues severely affect the cell performance and impede their practical applications. Herein, we develop a poly(ether imide) (PEI)-based membrane with a sponge-like pore morphology as the separator for the Li-S battery by a simplified phase inversion method. This new separator can not only alleviate the new challenges in Li-S batteries but also exhibit excellent ion conductivity, better thermal stability, and higher mechanical strength compared to those of the conventional polypropylene (PP) separator. A combined experimental and theoretical study indicates that the sponge-like morphology of the PEI membrane and its good wettability toward the electrolyte can facilitate uniform ion transportation and suppress dendrite growth. Meanwhile, the PEI molecules exhibit a strong interaction with polysulfides and avoid their shuttling effectively. As a result, the PEI-based Li-S battery shows a much better performance from various aspects (capacity, rate capability, and cycling stability) than that of the PP-based Li-S battery, especially at high charge/discharge current densities and high sulfur loadings. Since the developed PEI membrane can be easily scaled up, this work may accelerate the practical applications of Li-S batteries from the point of separators.

11.
Chemosphere ; 308(Pt 1): 136002, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35973505

RESUMO

Various fillers such as zeolites, metal-organic framework, carbon, metal framework, graphene, and covalent organic framework have been incorporated into the polymers. However, these materials are facing issues such as incompatibility with the polymer matrix, which leads to the formation of non-selective voids and thus, reduces the gas separation properties. Recent studies show that hexagonal boron nitride (h-BN) possesses attractive characteristics such as high aspect ratio, good compatibility with polymer materials, enhanced gas barrier performance, and improved mechanical properties, which could make h-BN the potential candidate to replace conventional fillers. The synthesis of materials and membranes is the subject of this review, which focuses on recent developments and ongoing problems. Additionally, a summary of the mathematical models that were utilised to forecast how well polymer composites would perform in gas separation is provided. It was found in the previous studies that tortuosity is the governing factor for the determination of the effectiveness of a nanofiller as a gas barrier enhancer in polymer matrices. The shape of the nanofiller particles and sheets, disorientation and distribution of the nanofillers within the polymer matrix, state of aggregation and rate of reaggregation of the nanofiller particles, as well as the compatibility of the nanofiller with the polymer matrix all played a significant role in determining how well a particular nanofiller will perform in enhancing the gas barrier properties of the nanocomposites. For this purpose, this review has been focused not only on the experimentation work but also on the effect of tortuosity, exfoliation quality, compatibility, disorientation, and reaggregation of nanofillers.

12.
Saudi J Biol Sci ; 29(5): 3586-3599, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35165505

RESUMO

Coronavirus disease is caused by the SARS-CoV-2 virus. The virus first appeared in Wuhan (China) in December 2019 and has spread globally. Till now, it affected 269 million people with 5.3 million deaths in 224 countries and territories. With the emergence of variants like Omicron, the COVID-19 cases grew exponentially, with thousands of deaths. The general symptoms of COVID-19 include fever, sore throat, cough, lung infections, and, in severe cases, acute respiratory distress syndrome, sepsis, and death. SARS-CoV-2 predominantly affects the lung, but it can also affect other organs such as the brain, heart, and gastrointestinal system. It is observed that 75 % of hospitalized COVID-19 patients have at least one COVID-19 associated comorbidity. The most common reported comorbidities are hypertension, NDs, diabetes, cancer, endothelial dysfunction, and CVDs. Moreover, older and pre-existing polypharmacy patients have worsened COVID-19 associated complications. SARS-CoV-2 also results in the hypercoagulability issues like gangrene, stroke, pulmonary embolism, and other associated complications. This review aims to provide the latest information on the impact of the COVID-19 on pre-existing comorbidities such as CVDs, NDs, COPD, and other complications. This review will help us to understand the current scenario of COVID-19 and comorbidities; thus, it will play an important role in the management and decision-making efforts to tackle such complications.

14.
J Food Biochem ; 45(5): e13720, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33856706

RESUMO

Moringa oleifera is an excellent source of phenolics and flavonoids comprise various pharmacological activities. The fourth widespread leading cause of the patients' death is liver cancer. This study was formulated to perform the antiproliferative activity of Moringa oleifera fruit (MOF) extract on human liver cancer HepG2 cells and computational validation of cell death. HepG2 cell line was treated with 25, 50, 75, 100, and 200 µg/ml of MOF extract for 48 hr, and antiproliferative activity was analyzed using MTT assay, nuclear condensation, annexin V-FITC/PI double stain, ROS generation, and apoptosis executioner enzyme caspase-3. MOF extract reduced the cell viability significantly (p Ë‚ .05) by increasing cellular apoptosis which was confirmed by annexin V-FITC/PI staining assay. In addition, MOF stimulated intracellular ROS production and subsequently induced caspase-3 activity depending upon dose. In silico analysis revealed the good binding interaction between amino acid residues of caspase-3 (PDB ID: 1GFW) protein and selected active constituents of MOF. PASS analyses of the phytoconstituents showed no violation of Lipinski's rule of five. Analysis of drug-likeness and toxicity measurement exhibited drug-like candidates with no predicted toxicity. In conclusion, this study showed the potential anticancer activity of MOF extract which may be valuable source for anticancer drug development. PRACTICAL APPLICATIONS: Moringa oleifera fruit extract induced the anti-proliferative activity against human hepatocellular carcinoma HepG2 cells through ROS-mediated apoptosis and activation of caspase-3 enzyme. Structure-based virtual screening study between bioactive components of Moringa oleifera fruits and apoptosis executioner caspase-3 enzyme has validated the anti-proliferative activity of Moringa oleifera fruit extract. Interestingly, active phytoconstituents of Moringa oleifera fruit exhibited drug-like candidates with no predicted toxicity. Thus, Moringa oleifera fruit could be used as valuable source for anticancer drug development against human liver cancer with relatively non-toxic to healthy cells.


Assuntos
Neoplasias Hepáticas , Moringa oleifera , Caspase 3 , Frutas , Células Hep G2 , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Simulação de Acoplamento Molecular , Extratos Vegetais/farmacologia , Folhas de Planta
15.
J Clin Neurosci ; 86: 110-115, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33775313

RESUMO

Bevacizumab (BEV) is an anti-angiogenesis antibody which has shown favorable therapeutic effects on some solid tumors. However, many clinical trials showed that BEV could only improve PFS instead of OS in glioblastoma (GBM) patients. However, some studies indicate that specific molecular subtypes of GBM could still benefit from combination treatment of BEV and Stupp protocol. Through the subgroup analysis of GSE84010 dataset, we found the neural and proneural subgroup can benefit from the administration of BEV in terms of OS, which is statistically significant. The further KEGG pathway enrichment analysis showed cell adhesion molecules (CAMs) pathway was enriched, and the expression of ITGAM has a predictive value for prognosis. These findings can provide some hints for future administration of BEV in newly diagnosed GBM patients.


Assuntos
Antineoplásicos Imunológicos/uso terapêutico , Bevacizumab/uso terapêutico , Neoplasias Encefálicas/genética , Moléculas de Adesão Celular/genética , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Glioblastoma/genética , Adulto , Idoso , Antineoplásicos Imunológicos/farmacologia , Bevacizumab/farmacologia , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/metabolismo , Moléculas de Adesão Celular/metabolismo , Terapia Combinada , Bases de Dados Genéticas/tendências , Método Duplo-Cego , Resistencia a Medicamentos Antineoplásicos/fisiologia , Feminino , Glioblastoma/tratamento farmacológico , Glioblastoma/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
16.
Membranes (Basel) ; 11(1)2021 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-33429885

RESUMO

In this work, the treatment of oily wastewater was investigated using developed cellulose acetate (CA) membranes blended with Nylon 66. Membrane characterization and permeation results in terms of oil rejection and flux were compared with a commercial CA membrane. The solution casting method was used to fabricate membranes composed of CA and Nylon 66. Scanning Electron Microscopy (SEM) analysis was done to examine the surface morphology of the membrane as well as the influence of solvent on the overall structure of the developed membranes. Mechanical and thermal properties of developed blended membranes and a commercial membrane were examined by thermogravimetric analysis (TGA) and universal (tensile) testing machine (UTM). Membrane characterizations revealed that the thermal and mechanical properties of the fabricated blended membranes better than those of the commercial membrane. Membrane fluxes and rejection of oil as a function of Nylon 66 compositions and transmembrane pressure were measured. Experimental results revealed that the synthetic membrane (composed of 2% Nylon 66 and Dimethyl Sulfoxide (DMSO) as a solvent) gave a permeate flux of 33 L/m2h and an oil rejection of around 90%, whereas the commercial membrane showed a permeate flux of 22 L/m2h and an oil rejection of 70%.

17.
Dental press j. orthod. (Impr.) ; 25(6): 59-68, Nov.-Dec. 2020. tab, graf
Artigo em Inglês | LILACS, BBO | ID: biblio-1154058

RESUMO

ABSTRACT Objectives: Assess the stability of three different mini-implants, based on thread shape factor (TSF), and evaluate stresses at the mini-implant site and surrounding cortical bone on application of retraction force, at two different insertion angles. Methods: Mini-implants of three different diameters (M1 - Orthoimplant, 1.8mm), (M2 - Tomas, 1.6mm) and (M3 - Vector TAS, 1.4mm) and length of 8mm were used. Using scanning electronic microscopy, the mean thread depth, pitch and relationship between the two (TSF) were calculated. The mini-implants were loaded into a synthetic bone block and the pull-out strength was tested. One way ANOVA and Tukey post-hoc tests were used to compare the pull-out strength of mini-implants. P values < 0.05 were considered statistically significant. Finite element models (FEM) were constructed with insertion angulation at 90° and 60°, with retraction force of 150 g. The results were analyzed using ANSYS software. Results: Statistically significant difference was found among all the three mini-implants for thread depth and pitch (< 0.001). Statistically significant higher pull-out force value was seen for Orthoimplant. The stress distribution level in mini-implant and surrounding bone was observed to be smaller for Orthoimplant. Conclusion: Orthoimplant mini-implants have more favorable geometric characteristics among the three types, and less stress with 90°angulation.


RESUMO Objetivos: Avaliar a estabilidade de três diferentes tipos de mini-implantes, com base no fator formato da rosca (thread shape factor, TSF), e avaliar a tensão no local de inserção e no osso cortical ao redor dos mini-implantes inseridos com dois ângulos diferentes, durante a aplicação de força para retração. Métodos: Foram usados três diferentes diâmetros de mini-implantes, sendo eles 1,8 mm (M1, ORTHO Implant), 1,6 mm (M2, Tomas) e 1,4 mm (M3, Vector TAS), todos com comprimento de 8 mm. Por meio da microscopia eletrônica de varredura, foram calculados a profundidade da rosca, o passo da rosca (distância entre os filetes da rosca) e a relação entre os dois (TSF). Para realização do teste de tração (pull-out), os mini-implantes foram inseridos em um bloco de osso sintético. Os testes ANOVA de uma via e post-hoc de Tukey foram usados para comparar as forças de resistência à tração dos mini-implantes, considerando-se estatisticamente significativos valores de p< 0,05. Modelos de elementos finitos (MEF) foram gerados com ângulos de inserção dos mini-implantes a 90° e 60°, com força de retração em 150g. Os resultados foram analisados usando-se o software ANSYS. Resultados: Diferenças estatisticamente significativas foram encontradas entre os três mini-implantes quanto à profundidade da rosca e o passo da rosca (p< 0,001). O ORTHO Implant apresentou a maior força de resistência à tração, com significância estatística. O nível de distribuição das tensões no mini-implante e no osso circundante também foi menor para o ORTHO Implant. Resultados: Entre os diferentes tipos de mini-implantes analisados, o ORTHO Implant apresentou as características geométricas mais favoráveis e a menor tensão com o ângulo de inserção de 90°.


Assuntos
Implantes Dentários , Análise do Estresse Dentário , Estresse Mecânico , Software , Análise de Elementos Finitos
18.
Environ Technol ; 40(7): 843-854, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29161995

RESUMO

Most of the polymers and their blends, utilized in carbon capture membranes, are costly, but cellulose acetate (CA) being inexpensive is a lucrative choice. In this research, pure and mixed matrix membranes (MMMs) have been fabricated to capture carbon from natural gas. Polyethylene glycol (PEG) has been utilized in the fabrication of membranes to modify the chain flexibility of polymers. Multi-walled carbon nanotubes (MWCNTs) provide mechanical strength, thermal stability, an extra free path for CO2 molecules and augment CO2/CH4 selectivity. Membranes of pure CA, CA/PEG blend of different PEG concentrations (5%, 10%, 15%) and CA/PEG/MWCNTs blend of 10% PEG with different MWCNTs concentrations (5%, 10%, 15%) were prepared in acetone using solution casting techniques. Fabricated membranes were characterized using SEM, TGA and tensile testing. Permeation results revealed remarkable improvement in CO2/CH4 selectivity. In single gas experiments, CO2/CH4 selectivity is enhanced 8 times for pure membranes containing 10% PEG and 14 times for MMMs containing 10% MWCNTs. In mix gas experiments, the CO2/CH4 selectivity is increased 13 times for 10% PEG and 18 times for MMMs with 10% MWCNTs. Fabricated MMMs have a tensile strength of 13 MPa and are more thermally stable than CA membranes.


Assuntos
Nanotubos de Carbono , Gás Natural , Membranas Artificiais , Polietilenoglicóis , Polímeros
19.
Pak J Pharm Sci ; 30(5): 1665-1669, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29084688

RESUMO

The aim of the study was to investigate the effects of effects of storage and temperature on the antioxidant potential, vitamin-C contents, total as well as selected individual phenolic acids and flavonoids of fresh aqueous leaves extract of Azadirachta Indica. The antioxidant activity of Azadirachta Indica leaves aqueous extract was determined by scavenging of DPPH free radical, while the phenolic compounds and vitamin-C contents by HPLC method. The analyses were carried out on crude extract of fresh leaves and after storage time of 1, 2 and 3 month at temperature of 20, 30 and 50°C. Storage for longer duration and rise in temperature caused decreasing the phenolic acids and vitamin C contents as well as antioxidant potential. Vitamin C contents were decreased up to 91% upon storage for 3 months at 50°C, while the anti-oxidant potential was decreased 29 %. The effect of storage time and temperature on individual phenolic acid and flavonoids were also remarkable, except ferulic acid which increased upon storage and rise in temperature.


Assuntos
Antioxidantes/farmacologia , Ácido Ascórbico/farmacologia , Azadirachta/química , Extratos Vegetais/farmacologia , Folhas de Planta/química , Polifenóis/farmacologia , Temperatura , Antioxidantes/isolamento & purificação , Ácido Ascórbico/isolamento & purificação , Compostos de Bifenilo/química , Cromatografia Líquida de Alta Pressão , Estabilidade de Medicamentos , Armazenamento de Medicamentos , Picratos/química , Extratos Vegetais/isolamento & purificação , Polifenóis/isolamento & purificação , Fatores de Tempo
20.
EXCLI J ; 16: 810-823, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28694767

RESUMO

Biological effects of rutin bioactive are limited due to its poor oral bioavailability and its degradation in aqueous environments. For the purpose of bioenhancement, different nanoemulsion systems of rutin were developed by aqueous titration method using water as dispersion media. The nanoemulsion systems were characterized for surface morphology, droplet size, polydispersity index, zeta potential, in vitro release profile and the formulations were optimized. The anticancer potential of optimized nanoemulsion was evaluated by cells viability (MTT) assay, nuclear condensation, and ROS activity using human prostate cancer (PC3) cell line. On the basis of cell viability data the inhibitory concentration (IC50) value for optimized nanoemulsion formulation on PC3 cancer cells was found to be 11.8 µM. Fluorescent microscopic analysis and intracellular ROS generation demonstrated significant ROS induction that might lead to triggering the apoptosis pathway. In conclusion, developed nanoemulsion displayed significant efficacy against prostate carcinoma cells.

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