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1.
Environ Res ; 259: 119445, 2024 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-38942259

RESUMO

In present investigation, Carica papaya leaf extract has been employed as a bio-reductant agent in order to synthesize ecologically sustainable bio-coupled gold nanoparticles. The formation of gold nanoparticles was confirmed based on colour change of solution and its surface plasmon resonance peak measured using UV-Vis Spectrophotometer (UV-Vis). The Morphology and size of nanoparticles were determined using transmission electron microscope (SEM/TEM), and its crystalline structure by X-ray diffraction studies. Surface area was determined via BET isotherm analysis. The elemental composition of Au nanoparticles was developed using the technique of energy dispersive spectroscopy (EDS). Furthermore, FTIR analysis delineated the presence of functional groups present in the samples of the synthesized AuNPs. Thus, the efficiency of bio coupled Au nanoparticles in photo catalytically decomposing methylene blue was examined under the influence of visible light., the lethal MB colorant had been reduced to 95 % Within 90 min. And also 60% TOC removal was recorded after 5 min of degradation reaction, which increased to 99% after 90 min. Furthermore, cytotoxic experiments on Michigan Cancer Foundations-7 (MCF-7) cell lines showed that Au nanoparticles are effective anticancer agents with an IC50 of 87.2 g/mL on the top of the present work revealed the eco-safety and affordable production of Au nanoparticles from Carica papaya leaf extract, which displayed photocatalytic debasement of organic pollutants and cyto-toxicity effects was investigated.


Assuntos
Carica , Flavonoides , Ouro , Nanopartículas Metálicas , Extratos Vegetais , Folhas de Planta , Ouro/química , Nanopartículas Metálicas/química , Folhas de Planta/química , Carica/química , Extratos Vegetais/química , Flavonoides/análise , Flavonoides/química , Humanos , Células MCF-7 , Azul de Metileno
2.
Doc Ophthalmol ; 148(2): 75-85, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38488946

RESUMO

The pattern electroretinogram (PERG) is a localized retinal response evoked by a contrast-reversing pattern, usually a black and white checkerboard, which provides information about macular and retinal ganglion cell function. This document, from the International Society for Clinical Electrophysiology of Vision (ISCEV; www.iscev.org ) presents an updated and revised Standard for clinical PERG testing. This replaces the 2013 and all earlier versions. Minimum protocols for basic PERG stimuli, recording methods and reporting are specified, to promote consistency of methods for diagnosis and monitoring purposes, while responding to evolving clinical practices and technology. The main changes in the updated ISCEV Standard for clinical PERG include expanded guidance about large stimulus fields, stimulus parameters for simultaneous PERG and pattern visual evoked potential recording, baseline drift correction, and use of consistent ambient room lighting. These changes aim to provide a clinically relevant document about current practice which will facilitate good quality recordings and inter-laboratory comparisons.


Assuntos
Eletrorretinografia , Potenciais Evocados Visuais , Eletrorretinografia/métodos , Retina , Visão Ocular , Células Ganglionares da Retina
3.
J Environ Sci (China) ; 139: 389-417, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38105064

RESUMO

This review provides insight into the current research trend in transition metal oxides (TMOs)-based photocatalysis in removing the organic colouring matters from water. For easy understanding, the research progress has been presented in four generations according to the catalyst composition and mode of application, viz: single component TMOs (the first-generation), doped TMOs/binary TMOs/doped binary TMOs (the second-generation), inactive/active support-immobilized TMOs (the third-generation), and ternary/quaternary compositions (the fourth-generation). The first two generations represent suspended catalysts, the third generation is supported catalysts, and the fourth generation can be suspended or supported. The review provides an elaborated comparison between suspended and supported catalysts, their general/specific requirements, key factors controlling degradation, and the methodologies for performance evaluation. All the plausible fundamental and advanced dye degradation mechanisms involved in each generation of catalysts were demonstrated. The existing challenges in TMOs-based photocatalysis and how the researchers approach the hitch to resolve it effectively are discussed. Future research trends are also presented.


Assuntos
Poluentes Ambientais , Óxidos , Água
4.
Langmuir ; 39(17): 6018-6028, 2023 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-37075327

RESUMO

Screening a green corrosion inhibitor that can prevent Al anode corrosion and enhance the battery performance is highly significant for developing next-generation Al-air batteries. This work explores the non-toxic, environmentally safe, and nitrogen-rich amino acid derivative, N(α)-Boc-l-tryptophan (BCTO), as a green corrosion inhibitor for Al anodes. Our results confirm that BCTO has an excellent corrosion inhibition effect for the Al-5052 alloy in 4 M NaOH solution. An optimum inhibitor addition (2 mM) has increased the Al-air battery performance; the corrosion inhibition efficiency was 68.2%, and the anode utilization efficiency reached 92.0%. The capacity and energy density values increased from 990.10 mA h g-1 and 1317.23 W h kg-1 of the uninhibited system to 2739.70 mA h g-1 and 3723.53 W h kg-1 for the 2 mM BCTO added system. The adsorption behavior of BCTO on the Al-5052 surface was further explored by theoretical calculations. This work paves the way for constructing durable Al-air batteries through an electrolyte regulation strategy.

5.
Med J Malaysia ; 78(3): 389-403, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37271850

RESUMO

INTRODUCTION: About 20 to 40% of ischaemic stroke causes are cryptogenic. Embolic stroke of undetermined source (ESUS) is a subtype of cryptogenic stroke which is diagnosed based on specific criteria. Even though patent foramen ovale (PFO) is linked with the risk of stroke, it is found in about 25% of the general population, so it might be an innocent bystander. The best way to treat ESUS patients with PFO is still up for discussion. MATERIALS AND METHODS: Therefore, based on current evidence and expert opinion, Malaysian expert panels from various disciplines have gathered to discuss the management of ESUS patients with PFO. This consensus sought to educate Malaysian healthcare professionals to diagnose and manage PFO in ESUS patients based on local resources and facilities. RESULTS: Based on consensus, the Malaysian expert recommended PFO closure for embolic stroke patients who were younger than 60, had high RoPE scores and did not require long-term anticoagulation. However, the decision should be made after other mechanisms of stroke have been ruled out via thorough investigation and multidisciplinary evaluation. The PFO screening should be made using readily available imaging modalities, ideally contrasttransthoracic echocardiogram (c-TTE) or contrasttranscranial Doppler (c-TCD). The contrast-transesophageal echocardiogram (c-TEE) should be used for the confirmation of PFO diagnosis. The experts advised closing PFO as early as possible because there is limited evidence for late closure. For the post-closure follow-up management, dual antiplatelet therapy (DAPT) for one to three months, followed by single antiplatelet therapy (APT) for six months, is advised. Nonetheless, with joint care from a cardiologist and a neurologist, the multidisciplinary team will decide on the continuation of therapy.


Assuntos
Isquemia Encefálica , AVC Embólico , Forame Oval Patente , AVC Isquêmico , Acidente Vascular Cerebral , Humanos , Forame Oval Patente/complicações , Forame Oval Patente/diagnóstico , Forame Oval Patente/terapia , Acidente Vascular Cerebral/diagnóstico , Acidente Vascular Cerebral/etiologia , Acidente Vascular Cerebral/terapia , AVC Embólico/complicações , Consenso
6.
Osteoarthritis Cartilage ; 30(1): 147-159, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34547432

RESUMO

OBJECTIVE: There is a need to incorporate multiple tissues into in vitro OA models to evaluate novel therapeutics. This approach is limited by inherent donor variability. We present an optimized research tool: a human OA cartilage-synovium explant co-culture model (OA-EXM) that employs donor-matched lower and upper limit response controls combined with statistical approaches to address variability. Multiple rapid read-outs allow for evaluation of therapeutics while cataloguing cartilage-synovium interactions. DESIGN: 48-h human explant cultures were sourced from OA knee arthroplasties. An OA-like cartilage-synovium co-culture baseline was established relative to donor-matched upper limit supraphysiological pro-inflammatory cytokine and lower limit OA cartilage or synovium alone controls. 100 nM dexamethasone treatment validated possible "rescue effects" within the OA-EXM dual tissue environment. Gene expression, proteoglycan loss, MMP activity, and soluble protein concentrations were analyzed using blocking and clustering methods. RESULTS: The OA-EXM demonstrates the value of the co-culture approach as the addition of OA synovium increases OA cartilage proteoglycan loss and expression of MMP1, MMP3, MMP13, CXCL8, CCL2, IL6, and PTGS2, but not to the extent of supraphysiological stimulation. Conversely, OA cartilage does not affect gene expression or MMP activity of OA synovium. Dexamethasone shows dual treatment effects on synovium (pro-resolving macrophage upregulation, protease downregulation) and cartilage (pro-inflammatory, catabolic, and anabolic downregulation), and decreases soluble CCL2 levels in co-culture, thereby validating OA-EXM utility. CONCLUSIONS: The OA-EXM is representative of late-stage OA pathology, captures dual interactions between cartilage and synovium, and combined with statistical strategies provides a rapid, sensitive research tool for evaluating OA therapeutics.


Assuntos
Cartilagem Articular/patologia , Osteoartrite/patologia , Membrana Sinovial/patologia , Idoso , Idoso de 80 Anos ou mais , Técnicas de Cocultura , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada
7.
Osteoarthritis Cartilage ; 30(8): 1050-1061, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35460872

RESUMO

Joint-on-a-chip (JOC) models are powerful tools that aid in osteoarthritis (OA) research. These microfluidic devices apply emerging organ-on-a-chip technology to recapitulate a multifaceted joint tissue microenvironment. JOCs address the need for advanced, dynamic in vitro models that can mimic the in vivo tissue environment through joint-relevant biomechanical or fluidic integration, an aspect that existing in vitro OA models lack. There are existing review articles on OA models that focus on animal, tissue explant, and two-dimensional and three-dimensional (3D) culture systems, including microbioreactors and 3D printing technology, but there has been limited discussion of JOC models. The aim of this article is to review recent developments in human JOC technology and identify gaps for future advancements. Specifically, mechanical stimulation systems that mimic articular movement, multi-joint tissue cultures that enable crosstalk, and systems that aim to capture aspects of OA inflammation by incorporating immune cells are covered. The development of an advanced JOC model that captures the dynamic joint microenvironment will improve testing and translation of potential OA therapeutics.


Assuntos
Dispositivos Lab-On-A-Chip , Osteoartrite , Animais , Humanos , Engenharia Tecidual/métodos
8.
Langmuir ; 38(13): 3984-3992, 2022 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-35319222

RESUMO

N and S codoped carbon dots having good water solubility have been successfully made by a novel hydrothermal method and characterized by FTIR, XPS, and TEM. The as-synthesized CDs were carbon particles rich in polar functional groups less than 10 nm in size. Electrochemical measurements, gravimetry, and surface analysis methods were utilized to examine the inhibition characteristics and adsorption mechanism of CDs on the carbon steel in acid pickling solutions. Electrochemical measurements verified that the CDs displayed adequate protection with high inhibition efficiency of 97.8%. The long-term weight-loss experiments up to 72 h further confirmed the excellent corrosion inhibition at room temperature and 313 K. The results presented are helpful for the formulation of more effective acid pickling corrosion inhibitors.

9.
Chem Rec ; 22(7): e202200053, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35510981

RESUMO

Supramolecules-based drug delivery has attracted significant recent research attention as it could enhance drug solubility, retention time, targeting, and stimuli responsiveness. Among the different supramolecules and assemblies, the macrocycles and the supramolecular hydrogels are the two important categories investigated to a greater extent. Here, we provide the most recent advancements in these categories. Under macrocycles, reports on drug delivery by cyclodextrins, cucurbiturils, calixarenes/pillararenes, crown ethers and porphyrins are detailed. The second category discusses the supramolecular hydrogels of macrocycles/polymers and low molecular weight gelators. The updated information provided could be helpful to advance R & D in this vital area.


Assuntos
Ciclodextrinas , Sistemas de Liberação de Medicamentos , Hidrogéis , Polímeros
10.
BMC Neurol ; 21(1): 366, 2021 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-34548039

RESUMO

BACKGROUND: Spinal AVF (SAVF), a potentially treatable cause of myelopathy, remains a challenging diagnosis. Its rarity and non-specific imaging findings often result in misdiagnosis despite a high index of clinical suspicion. The classically described high T2 signal in the spinal cord or prominent vascular flow voids in the intradural space were not infrequently missed on initial imaging, only to be picked up at follow-up imaging after progression of symptoms. Additionally, small sized fistulas(< 1 mm) and SAVF involving less frequent locations like the craniocervical junction in a patient presenting with paraplegia further complicates the diagnosis. On rare occasions, acute atypical presentation following a surgery adds to the conundrum. Definite diagnosis with spinal angiography, the gold-standard modality requires the expertise of highly skilled interventionists which may otherwise lead to false negative findings. We describe four SAVF patients with unconventional presentations, highlighting less described clinical findings. CASE PRESENTATION: First was a 50-year-old man presented with spastic paraparesis and was found to have an AVF at the cervical region arising from the vertebral artery. Second, a 45-year-old man with acute paraplegia post-operatively, initially treated for a transverse myelitis before lumbar region AVF was detected. Thirdly, a 27-year-old man presented with subacute lower thoracic myelopathy and deteriorated after corticosteroid treatment. The last patient, who initially appeared to have conus medullaris/cauda equina syndrome had a SAVF at the mid thoracic level. Presentation varied with some exhibiting acute deterioration mimicking other spinal cord pathology such as inflammatory disorders. All patients eventually underwent endovascular treatment with successful embolization of SDAVF. None of them exhibited further neurological deterioration after embolization. CONCLUSION: Successful treatment of SAVF is possible provided the diagnosis is made early, allowing timely intervention. Certain clues may aid the diagnosis. Firstly, arteriovenous fistula can be located distant to the clinical localization of myelopathy resulting in the unexpected longitudinally extensive spinal cord signal change. This clinical-radiological discrepancy can be a useful clue in diagnosing SAVF. Secondly, an acute myelopathic presentation immediately post-surgery may be related to SAVF. Other SAVF feature of note includes progressive myelopathy mimicking immune-mediated myelitis among young adults below 30 years of age refractory to immune therapy.


Assuntos
Fístula Arteriovenosa , Malformações Vasculares do Sistema Nervoso Central , Compressão da Medula Espinal , Doenças da Medula Espinal , Adulto , Fístula Arteriovenosa/complicações , Fístula Arteriovenosa/diagnóstico por imagem , Fístula Arteriovenosa/terapia , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Medula Espinal , Adulto Jovem
11.
Inflammopharmacology ; 28(4): 929-938, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31487002

RESUMO

The leaves of traditionally used herbal plant Tridax procumbens L. contain lots of phytochemicals having potency to reduce inflammation. In this study, the ethanol extract of the leaves of Tridax procumbens L. was analysed for the phytochemicals by GC-MS. The anti-inflammatory activity was then studied with the extract of 10, 50, and 100 mg/kg b.wt in carrageenan-induced mice model by measuring the inflammatory oedema and by analysing the histopathology. The mRNA expression levels of TNF-α and COX2 genes were studied in the inflammatory site to explore the molecular action by reverse transcription PCR and qPCR analyses. A significant (P ≤ 0.01) reduction in mice paw inflammation and a recovered histology were observed in treated groups when compared to control group in 24 h. The RT-PCR results showed a significant (P ≤ 0.01) decrease in the expression levels of TNF-α and COX2 in terms of band density in treated mice compared to control group. The qPCR RQ values also were decreased in treated groups with respect to increasing doses (RQ values of 18.985 ± 0.230, 12.140 ± 1.121, 6.718 ± 0.807 for TNF-α and 15.583 ± 1.043, 7.725 ± 1.013, 5.075 ± 0.615 for COX2, respectively for the three doses) in comparison with the control group (TNF-α 27.107 ± 2.254, COX2 20.626 ± 1.477). Tridax procumbens L. can be, thus, used for the development of a safe, natural, anti-inflammatory drug as it showed a strong inhibitory action on inflammation by acting at molecular level.


Assuntos
Asteraceae/química , Ciclo-Oxigenase 2/metabolismo , Expressão Gênica/efeitos dos fármacos , Inflamação/tratamento farmacológico , Extratos Vegetais/farmacologia , Folhas de Planta/química , Fator de Necrose Tumoral alfa/metabolismo , Animais , Anti-Inflamatórios/farmacologia , Carragenina/farmacologia , Edema/induzido quimicamente , Edema/tratamento farmacológico , Edema/metabolismo , Inflamação/induzido quimicamente , Inflamação/metabolismo , Masculino , Camundongos
13.
Cytotherapy ; 21(10): 1019-1024, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31526643

RESUMO

The International Society for Cell & Gene Therapy (ISCT®) Mesenchymal Stromal Cell (ISCT MSC) committee offers a position statement to clarify the nomenclature of mesenchymal stromal cells (MSCs). The ISCT MSC committee continues to support the use of the acronym "MSCs" but recommends this be (i) supplemented by tissue-source origin of the cells, which would highlight tissue-specific properties; (ii) intended as MSCs unless rigorous evidence for stemness exists that can be supported by both in vitro and in vivo data; and (iii) associated with robust matrix of functional assays to demonstrate MSC properties, which are not generically defined but informed by the intended therapeutic mode of actions.


Assuntos
Terapia Baseada em Transplante de Células e Tecidos/classificação , Terapia Genética/classificação , Células-Tronco Mesenquimais/classificação , Células Estromais/classificação , Terminologia como Assunto , Técnicas de Cultura de Células/classificação , Técnicas de Cultura de Células/métodos , Técnicas de Cultura de Células/normas , Diferenciação Celular , Terapia Genética/métodos , Humanos , Internacionalidade , Células-Tronco Mesenquimais/citologia , Sociedades Médicas/normas , Células Estromais/citologia
14.
Mol Cell Biochem ; 460(1-2): 105-112, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31300983

RESUMO

This study aimed to find out the molecular therapeutic effect of lipo-ATRA on tumour suppressor TIG3 and cell proliferative biomarker PPARγ in B (a) P-induced lung cancer model. In RT-PCR study, ATRA- and lipo-ATRA-treated mice samples showed relatively higher TIG3 expression and decreased PPARγ expression (Band density) than cancer control. Among treatments, lipo-ATRA showed vital effect than free ATRA by enhancing TIG3 and decreasing PPARγ. The qPCR results also showed significant (p ≤ 0.05) difference in both TIG3 and PPAR (RQ values of TIG3, lipo-ATRA 23.85 ± 1.29; free ATRA 10.43 ± 1.81 and for PPARγ, lipo-ATRA 4.707 ± 1.21; free ATRA 15.78 ± 2.34). From this, we conclude that liposomal ATRA formulation is most preferable for prolonged delivery of ATRA at targeted site to favour molecular action. It implies that the therapeutic effect of lipo-ATRA in lung cancer was exhibited by ameliorating the TIG3 expression and by suppressing the expression of PPARγ.


Assuntos
Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Neoplasias Pulmonares/genética , PPAR gama/genética , Receptores do Ácido Retinoico/genética , Tretinoína/farmacologia , Proteínas Supressoras de Tumor/metabolismo , Animais , Modelos Animais de Doenças , Lipossomos , Neoplasias Pulmonares/patologia , Masculino , Camundongos , PPAR gama/metabolismo , Receptores do Ácido Retinoico/metabolismo , Proteínas Supressoras de Tumor/genética
15.
Osteoarthritis Cartilage ; 25(5): 737-741, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-27894935

RESUMO

OBJECTIVE: Although, mesenchymal stromal cells (MSCs) are being clinically investigated for their use in osteoarthritis (OA), it is unclear whether their postulated therapeutic properties are equally effective in the early- and late-stages of OA. In this study we investigated MSC cytokine secretion post-exposure to synovial fluid (SF), obtained from early- vs late-stage knee OA patients to justify a potential patient stratification strategy to maximize MSC-mediated treatment effects. METHOD: Subjects were recruited and categorized into early- [Kellgren-Lawrence (KL) grade I/II, n = 12] and late-stage (KL-III/IV, n = 12) knee OA groups. SF samples were obtained, and their proteome was tested using multiplex assays, after 3-days culture, with and without MSCs. SFs cultured without MSCs were used as a baseline to identify MSC-secreted factors into SFs cultured with MSCs. Linear mixed-effect models and non-parametric tests were used to identify alterations in the MSC secretome during exposure to OA SF (3-days). MSCs cultured for 3-days in 0.5% fetal bovine serum (FBS)-supplemented medium were used to compare SF results with culture medium. RESULTS: Following exposure to OA SF, the MSC secretome contained proteins that are involved in tissue repair, angiogenesis, chemotaxis, matrix remodeling and the clotting process. However, chemokine (C-X-C motif) ligand-8 (CXCL8; chemoattractant), interleukin-6 (IL6) and chemokine (C-C motif) ligand 2 (CCL2) were elevated in the MSC-secretome in response to early- vs late-stage OA SF. CONCLUSION: Early- vs late-stage OA SF samples elicit a differential MSC secretome response, arguing for stratification of OA patients to maximize MSC-mediated therapeutic effects.


Assuntos
Citocinas/metabolismo , Células-Tronco Mesenquimais/metabolismo , Osteoartrite do Joelho/metabolismo , Osteoartrite do Joelho/patologia , Líquido Sinovial/metabolismo , Células Cultivadas , Quimiocina CCL2/metabolismo , Humanos , Interleucina-6/metabolismo , Reprodutibilidade dos Testes , Índice de Gravidade de Doença , Técnicas de Cultura de Tecidos
16.
Neuroimage ; 139: 439-449, 2016 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-27374370

RESUMO

Movements result from a complex interplay of multiple brain regions. These regions are assembled into distinct functional networks depending on the specific properties of the action. However, the nature and details of the dynamics of this complex assembly process are unknown. In this study, we sought to identify key markers of the neural processes underlying the preparation and execution of motor actions that always occur irrespective of differences in movement initiation, hence the specific neural processes and functional networks involved. To this end, EEG activity was continuously recorded from 18 right-handed healthy participants while they performed a simple motor task consisting of button presses with the left or right index finger. The movement was performed either in response to a visual cue or at a self-chosen, i.e., non-cued point in time. Despite these substantial differences in movement initiation, dynamic properties of the EEG signals common to both conditions could be identified using time-frequency and phase locking analysis of the EEG data. In both conditions, a significant phase locking effect was observed that started prior to the movement onset in the δ-θ frequency band (2-7Hz), and that was strongest at the electrodes nearest to the contralateral motor region (M1). This phase locking effect did not have a counterpart in the corresponding power spectra (i.e., amplitudes), or in the event-related potentials. Our finding suggests that phase locking in the δ-θ frequency band is a ubiquitous movement-related signal independent of how the actual movement has been initiated. We therefore suggest that phase-locked neural oscillations in the motor cortex are a prerequisite for the preparation and execution of motor actions.


Assuntos
Sincronização Cortical , Ritmo Delta , Córtex Motor/fisiologia , Movimento , Ritmo Teta , Adulto , Eletroencefalografia , Potenciais Evocados , Feminino , Dedos , Humanos , Masculino , Atividade Motora , Desempenho Psicomotor , Adulto Jovem
17.
J Nanosci Nanotechnol ; 15(9): 6914-23, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26716263

RESUMO

We are all aware of growing environmental concerns, and the need to provide new and improved means for maintaining a healthy environment. Pesticides are the only toxic chemicals released intentionally into the environment to kill living organisms. Pesticide detection and destruction has become a very important and inevitable area of research because of the rapid expansion of agriculture and stringent environmental protection acts. Electrochemistry offers promising approaches for the determination and destruction of pollutants. The interaction of nanotechnology opens the possibility for a wide variety of chemical and biological research topics and day-to-day applications at the molecular and cellular level. Nanotechnology has allowed introducing novel strategies in sensors and biosensor research. Recently researchers have become increasingly interested in nanomaterial assisted electrochemical techniques. This review emphasizes the recent developments of electrochemical methods combined with nanotechnology for sensing and decontamination of pesticides.


Assuntos
Técnicas Eletroquímicas/métodos , Poluentes Ambientais/análise , Recuperação e Remediação Ambiental/métodos , Nanoestruturas/química , Praguicidas/análise , Poluentes Ambientais/química , Poluentes Ambientais/isolamento & purificação , Praguicidas/química , Praguicidas/isolamento & purificação
18.
J Nanosci Nanotechnol ; 15(1): 734-41, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26328435

RESUMO

Electrode materials having nanometer scale dimensions are expected to have property enhancements due to enhanced surface area and mass/charge transport kinetics. This is particularly relevant to intrinsically low electronically conductive materials such as lithium iron phosphate (LiFePO4), which is of recent research interest as a high performance intercalation electrode material for Li-ion batteries. Many of the reported works on LiFePO4 synthesis are unattractive either due to the high cost of raw materials or due to the complex synthesis technique. In this direction, synthesis of LiFePO4 directly from inexpensive FePO4 shows promise.The present study reports LiFePO4 nanostructures prepared from iron (III) phosphate (FePO4 x 2H2O) by precipitation-hydrothermal method. The sintered powder was characterized by X-ray diffractometry (XRD), X-ray photoelectron spectroscopy (XPS), Inductive coupled plasma-optical emission spectroscopy (ICP-OES), and Electron microscopy (SEM and TEM). Two synthesis methods, viz. bulk synthesis and anodized aluminum oxide (AAO) template-assisted synthesis are reported. By bulk synthesis, micro-sized particles having peculiar surface nanostructuring were formed at precipitation pH of 6.0 to 7.5 whereas typical nanosized LiFePO4 resulted at pH ≥ 8.0. An in-situ precipitation strategy inside the pores of AAO utilizing the spin coating was utilized for the AAO-template-assisted synthesis. The template with pores filled with the precipitate was subsequently subjected to hydrothermal process and high temperature sintering to fabricate compact rod-like structures.


Assuntos
Óxido de Alumínio/química , Técnicas de Química Sintética/métodos , Compostos Férricos/química , Ferro/química , Lítio/química , Nanoestruturas/química , Fosfatos/química , Fosfatos/síntese química , Temperatura Alta , Concentração de Íons de Hidrogênio , Tamanho da Partícula , Água
19.
Biomed Chromatogr ; 29(11): 1731-6, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25973544

RESUMO

A simple, rapid and sensitive LC-MS/MS method was developed and validated for the determination of free quercetin in rat plasma, using fisetin as internal standard. The detection was performed by negative ion electrospray ionization under selected reaction monitoring. Chromatographic separation (isocratic elution) was carried out using acetonitrile-10 m m ammonium formate (80:20, v/v) with 0.1% v/v formic acid. The lower limit of quantification (4.928 ng/mL) provided high sensitivity for the detection of quercetin in rat plasma. The linearity range was from 5 to 2000 ng/mL. Intra- and inter-day variability (RSD) of quercetin extraction from rat plasma was <4.19 and 1.37% with accuracies of 98.77 and 99.67%. The method developed was successfully applied for estimating free quercetin in rat plasma, after oral administration of quercetin-loaded biodegradable nanoparticles (QLN) and quercetin suspension. QLN (C(max), 1277.34 ± 216.67 ng/mL; AUC, 17,458.25 ± 3152.95 ng hr/mL) showed a 5.38-fold increase in relative bioavailability as compared with quercetin suspension (C(max), 369.2 ± 108.07 ng/mL; AUC, 3276.92 ± 396.67 ng hr/mL).


Assuntos
Cromatografia Líquida/métodos , Nanopartículas , Quercetina/sangue , Espectrometria de Massas por Ionização por Electrospray/métodos , Espectrometria de Massas em Tandem/métodos , Administração Oral , Animais , Limite de Detecção , Masculino , Quercetina/farmacocinética , Ratos , Ratos Sprague-Dawley , Reprodutibilidade dos Testes
20.
Curr Top Microbiol Immunol ; 367: 101-12, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23208552

RESUMO

Regenerative Medicine (RM) has the promise to revolutionize the treatment of many debilitating diseases for which the current therapies are inadequate. To realize the full potential of RM, a pragmatic approach needs to be taken by all stakeholders keeping in mind the lessons learnt from recombinant protein manufacturing, gene therapy trials, etc., to develop novel service delivery models for economic viability and regulatory processes in the absence of long-term data. In this chapter, we focus on the three main drivers of RM field and discuss the potential pitfalls and possible ways to mitigate them in order to move the field closer to clinical implementation.


Assuntos
Transplante de Células , Medicina Regenerativa , Engenharia Tecidual , Humanos
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