Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 22
Filtrar
1.
Methods Cell Biol ; 184: 149-158, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38555154

RESUMO

The functional importance of nitric oxide (NO) in the fields of immunology concerning its antimicrobial, anti-tumoral, anti-inflammatory, and immunosuppressive effects have made it inevitable to study its secretion from various cells. Nitrogen oxide synthase (NOS) is the enzyme responsible for synthesizing NO and its three isoforms function in a cell-dependent manner. NO is oxidized rapidly to Reactive nitrogen oxide species (RNOS) through which the roles of NO are being carried out. One of the major immune cells secreting NO is myeloid-derived suppressor cells (MDSCs). The function of these MDSCs in the suppression of T-cell proliferation as well as T-cell differentiation is found to be dependent on NO secretion. Apart from T-cell suppressive activity, NO is also known to interfere with natural killer (NK) cell functions. A convenient method to estimate NO secretion is by using Griess reagent named after Johann Peter Griess. In this method, NO reacts with the reagents to form a colored azo dye detectable using a microplate reader at a wavelength of 548nm. In this chapter, we summarized the detailed method of estimating NO from MDSCs by the Griess method.


Assuntos
Células Supressoras Mieloides , Neoplasias , Humanos , Células Supressoras Mieloides/fisiologia , Óxido Nítrico , Linfócitos T , Proliferação de Células
2.
Acta Ophthalmol ; 102(3): e229-e244, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-37578349

RESUMO

To compare the treatment efficacy of childhood myopia control optical interventions [spectacles, soft contact lenses (SCLs) and orthokeratology (OK) lenses], explore the consistency of treatment efficacies during the treatment period and evaluate the impact of baseline spherical equivalent refraction (SER), axial length (AL) and age on the treatment effect. A literature search of EMBASE, PubMed and Google Scholar databases identified 220 articles published between January 2000 and April 2022, which reported the treatment efficacy by differences in the SER and AL change between intervention and control groups. Thirty-five articles were included in the analysis. Treatment effect sizes (ESs) were calculated, where more positive and negative directions indicated greater treatment efficacy for SER and AL respectively. For SER, the ESs with peripheral add design spectacles (0.66) and SCLs (0.53) were large but not significantly different between treatment types (p = 0.69). For AL, ESs with peripheral add design spectacles (-0.37), SCLs (-0.55) and OK lenses (-0.93) were large, but OK lenses had a significantly greater effect than peripheral add design spectacles (p ≤ 0.001). ESs were large during the first 12 months of treatment for all interventions [peripheral add design SCLs and OK (F ≥ 5.39, p ≤ 0.01), peripheral add design spectacles (F = 0.47, p = 0.63)] but reduced towards the end of 24-36 months of treatment. Baseline SER had an impact on the treatment effect with peripheral add design spectacles only. Optical interventions are efficacious in controlling childhood myopia progression. However, treatment effects were largest only during the first 12 months of treatment and reduced over time.


Assuntos
Lentes de Contato Hidrofílicas , Miopia , Procedimentos Ortoceratológicos , Criança , Humanos , Miopia/prevenção & controle , Refração Ocular , Resultado do Tratamento , Comprimento Axial do Olho
3.
Int Immunopharmacol ; 123: 110671, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37494839

RESUMO

Regulatory effect of IL-6 on various immune cells plays a crucial role during experimental cerebral malaria pathogenesis. IL-6 neutralization can restore distorted ratios of myeloid dendritic cells and plasmacytoid dendritic cells as well as the balance between Th-17 and T-regulatory cells. IL-6 can also influence immune cells through classical and trans IL-6 signalling pathways. As trans IL-6 signalling is reportedly involved during malaria pathogenesis, we focused on studying the effects of trans IL-6 signalling blockade on various immune cell populations and how they regulate ECM progression. Results show that administration of sgp130Fc recombinant chimera protein lowers the parasitemia, increases the survivability of Plasmodium berghei ANKA infected mice, and restores the distorted ratios of M1/M2 macrophage, mDC/pDC, and Th-17/Treg. IL-6 trans signalling blockade has been found to affect both expansion of myeloid derived suppressor cells (MDSCs) and expression of inflammatory markers on them during Plasmodium berghei ANKA infection indicating that trans IL-6 signalling might regulate various immune cells and their function during ECM. In this work for the first time, we delineate the effect of sgp130Fc administration on influencing the immunological changes within the host secondary lymphoid organ during ECM induced by Plasmodium berghei ANKA infection.


Assuntos
Malária Cerebral , Células Supressoras Mieloides , Animais , Camundongos , Células Supressoras Mieloides/patologia , Interleucina-6 , Macrófagos/patologia , Células Dendríticas , Plasmodium berghei , Camundongos Endogâmicos C57BL
4.
Mol Immunol ; 152: 240-254, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36395532

RESUMO

Th9, a new subgroup of CD4+T cells is characterized by its specific cytokine IL-9, is a critical factor in allergic diseases, cancers and parasitic infections. This study aimed to explore the potential roles of Th9 cells in the immunopathogenesis of ECM. In splenocytes sourced from uninfected, PbA and Py infected mice, Th9 cells were characterised by flow cytometry, cell sorting and qPCR. Enhancement of CD4+IL-9+ (Th9) cells were observed in both the infections, which corroborated with increased expression of the differentiating transcription factors. Moreover, crucial cytokine receptors (IL-4R, TGF-ßR, IL-6R) as well as chemokine receptors (CCR3, CCR6 and CCR7) and activation marker (CD96), demonstrated elevation upon PbA infection in splenic Th9 cells. Furthermore, Neutralization of IL-9 along with IL-6 enhanced host survivability, reduced mean neurological score of ECM. However, anti- IL-9 treatment also down regulated frequency of Th17 cells, and its transcription factors pSTAT3, RORγT along with depleted Il-1ß and Il-6 expression. In sum, understanding how IL-9 producing CD4+ T-cells can alter Th17/Treg ratio and by that modulate host's immune response, could pave the way for developing immunomodulatory interventions against cerebral malaria.


Assuntos
Interleucina-9 , Malária Cerebral , Células Th17 , Animais , Camundongos , Interleucina-6/imunologia , Interleucina-9/imunologia , Malária Cerebral/imunologia , Linfócitos T Reguladores/imunologia , Células Th17/imunologia , Fatores de Transcrição/imunologia
5.
Cytokine ; 155: 155910, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35594680

RESUMO

Myeloid derived suppressor cells (MDSCs) are a group of heterogeneous cell populations that can suppress T cell responses. Various aspects of MDSCs in regulating immune responses in several cancer and infectious diseases have been reported till date. But the role and regulation of MDSCs have not been systematically studied in the context of malaria. This study depicts the phenotypic and functional characteristics of splenic MDSCs and how they regulate Th-17 mediated immune response during Experimental Cerebral Malaria (ECM). Flow cytometric analysis reveals that MDSCs in the spleen and bone marrow expand at 8 dpi during ECM. Among subtypes of MDSCs, PMN-MDSCs show significant expansion in the spleen but M-MDSCs remain unaltered. Functional analysis of sorted MDSCs from spleens of Plasmodium berghei ANKA (PbA) infected mice shows suppressive nature of these cells and high production of Nitric oxide (NO). Besides, MDSCs were also found to express various inflammatory markers during ECM suggesting the M1 type phenotype of these cells. In-vivo depletion of MDSCs by the use of Anti Gr-1 increases mice survival but doesn't significantly alter the parasitemia. Previously, it has been reported that Treg/Th-17 balance in the spleen is skewed towards Th-17 during ECM. Depletion of MDSCs was found to regulate Th-17 percentages to homeostatic levels and subvert various inflammatory changes in the spleen. Among different factors, IL-6 was found to play an important role in the expansion of MDSCs and expression of inflammatory markers on MDSCs in a STAT3-dependent manner. These findings provide a unique insight into the role of IL-6 in the expansion of the MDSC population which causes inflammatory changes and increased Th-17 responses during ECM.


Assuntos
Interleucina-6 , Malária Cerebral , Células Supressoras Mieloides , Células Th17 , Animais , Interleucina-6/imunologia , Malária Cerebral/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Células Supressoras Mieloides/imunologia , Baço , Células Th17/imunologia
6.
Optom Vis Sci ; 99(2): 137-149, 2022 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-34974458

RESUMO

SIGNIFICANCE: Psychophysical estimates of spatial and depth vision have been shown to be better after bilateral ReLEx small-incision lenticule extraction (SMILE) refractive surgery for myopia, relative to photorefractive keratectomy (PRK) and femtosecond laser-assisted in situ keratomileusis (FS-LASIK). The present study provides the optical basis for these findings using computational image quality analysis. PURPOSE: This study aimed to compare longitudinal changes in higher-order wavefront aberrations and image quality before and after bilateral PRK, FS-LASIK, and SMILE refractive procedures for correcting myopia. METHODS: Wavefront aberrations and image quality of both the eyes of 106 subjects (n = 40 for FS-LASIK and SMILE and n = 26 for PRK) were determined pre-operatively and at 1-week, 1-month, 3-month, and 6-month post-operative intervals using computational through-focus analysis for a 6-mm pupil diameter. Image quality was quantified in terms of its peak value and its interocular difference, residual defocus that was needed to achieve peak image quality (best focus), and the depth of focus. RESULTS: The increase in root mean squared deviations of higher-order aberrations post-operatively was lesser after SMILE (1-month visit median [25th to 75th interquartile range], 0.34 µm (0.28 to 0.39 µm]) than after PRK (0.80 µm [0.74 to 0.87 µm]) and FS-LASIK (0.74 µm [0.59 to 0.83 µm]; P ≤ .001), all relative to pre-operative values (0.20 µm [0.15 to 0.30 µm]). The peak image quality dropped and its interocular difference increased, best focus shifted myopically by 0.5 to 0.75 D, and depth of focus widened significantly after PRK and FS-LASIK surgeries, all relative to pre-operative values (P < .001). All these changes were negligible but statistically significant in a minority of instances after SMILE surgery (P ≥ .01). CONCLUSIONS: Although all three refractive surgeries correct myopia, the image quality and its similarity between eyes are better and closer to pre-operative values after SMILE, compared with FS-LASIK and PRK. These results can be explained from the underlying increase in higher-order wavefront aberrations experienced by the eye post-operatively.


Assuntos
Ceratomileuse Assistida por Excimer Laser In Situ , Miopia , Ceratectomia Fotorrefrativa , Substância Própria/cirurgia , Humanos , Ceratomileuse Assistida por Excimer Laser In Situ/métodos , Lasers de Excimer/uso terapêutico , Miopia/cirurgia , Ceratectomia Fotorrefrativa/métodos , Acuidade Visual
7.
ChemSusChem ; 14(18): 3693-3723, 2021 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-34270869

RESUMO

Sodium-ion batteries (SIBs) are gaining renewed interest as a promising alternative to the already commercialized lithium-ion batteries. The large abundance, low cost, and similar electrochemistry of sodium (compared with lithium) is attracting the attention of the research community for their deployment in energy storage devices. Despite the fact that there are adequate cathode materials, the choice of suitable anodes for SIBs is limited. Graphite, the most versatile anode for LIBs, exhibits poor performance in case of SIBs. Amorphous or disordered carbons (hard and soft carbon) have been the most promising and cost-effective anode materials for SIBs. This Review discusses the recent advances of various forms of amorphous or disordered carbons used in SIBs with emphasis on their synthesis processes and relationship between microstructure, morphology, and performance. A profound understanding of the charge storage mechanisms of sodium in these carbon materials has been deliberated. The performance of these anode materials also depends upon electrolyte optimization, which has been aptly conferred. However, these anodes are often plagued with large voltage loss, low initial coulombic efficiency, and formation of solid electrolyte interphase. In order to overcome these challenges, several mitigation strategies have been put forward in a concise way to offer visions for the deployment of these amorphous carbon materials for the progress and commercial success of SIBs.

8.
Microb Pathog ; 147: 104289, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32693118

RESUMO

Splenomegaly, a major symptom in Plasmodium infection, is extensively studied for its immunopathological role in mice malaria model infected with Plasmodium berghei ANKA. The status of autophagic regulation in hosts in malaria pathogenesis remains unreported till date. This study demonstrated the autophagy, proteasomal degradation and NRF2-KEAP1 antioxidant pathway status in the host during Plasmodium infection taking murine spleen as our organ of interest. Initial staining and autophagic gene expression indicate a possibility of autophagic pathway activation. Although the conversion of LC3A to LC3B and lysosome-autophagosome fusion increases, the final degradation step remains incomplete. Resultant upregulation of p62 and its altered phosphorylated status enhances its binding to keap1 causing NRF2 translocation to the nucleus. NRF2 act as transcription factor upregulating p62 level itself leading to an autoinduction loop of p62 expression. Interestingly, enhancement of P62 interaction with proteasome subunit RPT1 indicates a possible role in transporting ubiquitinated cargo to proteasome complex. Ubiquitination level increased with subsequent upregulation of all three modes of proteasomal degradation i.e trypsin-like, caspase-like and especially chymotrypsin-like. Sqstm1/p62 plays a critical central role in regulating autophagy, proteasomal degradation, and NRF2-KEAP1 pathway. The incomplete autophagic flux in the final step may be a key therapeutic target, as autophagic degradation and subsequent pathogenic peptide presentation is of utmost necessity for downstream immune response.


Assuntos
Malária , Fator 2 Relacionado a NF-E2 , Animais , Antioxidantes , Autofagia , Proteína 1 Associada a ECH Semelhante a Kelch , Camundongos , Fator 2 Relacionado a NF-E2/metabolismo , Complexo de Endopeptidases do Proteassoma , Proteína Sequestossoma-1/metabolismo , Transdução de Sinais , Baço/metabolismo
9.
Optom Vis Sci ; 97(5): 360-369, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32413008

RESUMO

SIGNIFICANCE: Laser refractive surgery procedures are efficacious at correcting myopia, but they result in long-term deterioration of optical quality that affects monocular and binocular visual performance. The study shows that the optical quality of the two eyes needs to be similar to optimize binocular visual performance after surgery. PURPOSE: This study aimed to systematically analyze longitudinal changes in optical quality, high- and low-contrast logMAR acuity and random-dot stereoacuity before and after three refractive surgery procedures for correcting myopia. METHODS: A total of 106 subjects (laser-assisted in situ keratomileusis, 40; photorefractive keratectomy, 26; small-incision lenticule extraction, 40) with myopia and astigmatism ≤1.5 D participated in this prospective cohort-based study. All aforementioned outcome variables were measured in both eyes pre-operatively and 1 week and 1, 3, and 6 months post-operatively. RESULTS: Pre-operative myopic spherical equivalent of refraction (median [25th to 75th interquartile range], -6.4 D [-8.0 to -4.2 D] for laser-assisted in situ keratomileusis, -4.3 D [-5.0 to -3.5 D] for photorefractive keratectomy, -5.5 D [-6.5 to -4.3 D] for small-incision lenticule extraction) was corrected to within ±0.75 D of emmetropia in all cohorts up to 6 months post-operatively (P < .001). Higher-order wavefront aberrations, uncorrected high- and low-contrast logMAR acuity, and stereoacuity all worsened and remained so up to 6 months post-operatively, relative to pre-operative values (P < .001). Stereoacuity worsened with both interocular average and difference in the magnitude of higher-order aberrations, whereas logMAR acuities worsened only with interocular average of these aberrations (r ≥ 0.40; P < .01 for all). CONCLUSIONS: Although the refractive surgery procedures tested here correct myopia, they result in a sustained (up to 6 months) loss of optical quality and spatial and depth-related visual functions post-operatively. Both interocular average and difference in the eye's optical quality seem to impair binocular visual functions after refractive surgery for myopia.


Assuntos
Percepção de Profundidade/fisiologia , Ceratomileuse Assistida por Excimer Laser In Situ/métodos , Lasers de Excimer/uso terapêutico , Miopia/cirurgia , Ceratectomia Fotorrefrativa/métodos , Refração Ocular/fisiologia , Processamento Espacial/fisiologia , Adulto , Feminino , Seguimentos , Humanos , Masculino , Miopia/fisiopatologia , Estudos Prospectivos , Testes Visuais , Acuidade Visual/fisiologia , Adulto Jovem
10.
Dalton Trans ; 49(1): 147-155, 2020 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-31793580

RESUMO

Most of the transition metal bismuth salts have excellent visible absorption range and carrier transport properties due to their unique structure capable of orbits and s-p bonds. As one of the transition metal bismuth salts, Bi3TaO7 is firstly directly prepared on fluorine-doped SnO2 transparent conductive glass (FTO) as a photoanode for photoelectrochemical (PEC) water oxidation via a simple hydrothermal method using a special precursor solution. The growth mechanism of the Bi3TaO7 film is investigated in detail. Besides, the Bi3TaO7 photoanode exhibits a wide visible light response range with an optical band gap of 2.88 eV, which is useful for its PEC properties. Bi3TaO7 achieves an excellent PEC performance by tuning the calcination temperature, producing a photocurrent density of 23.0 µA cm-2 at 1.23 V vs. RHE and showing excellent stability that decays by only 2% after illumination for 6000 s. The above results indicate that Bi3TaO7 has broad application prospects in the field of PEC water oxidation.

11.
Microbes Infect ; 21(10): 475-484, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31185303

RESUMO

Splenic plasmacytoid dendritic cells (pDC) possess the capability to harbor live replicative Plasmodium parasite. Isolated splenic pDC from infected mice causes malaria when transferred to naïve mice. Incomplete autophagic degradation might cause poor antigen processing and poor immune response. Induction of autophagic flux by rapamycin treatment led to better prognosis by boosting pDC centered immune response against the pathogen. Splenic pDC from rapamycin-treated infected mice, caused less parasitemia in naïve mice. The downregulation of adhesion with unaltered phagocytic potential of the cells post autophagic induction restricted excessive parasite burden within them. Rapamycin-treated pDC played a better role in antigen presentation. They showed higher expression of co-stimulatory molecules CD80, CD86, DEC205, MHCI. Rapamycin-treated pDC induced CD28 expression on CD8+ T cells and suppressed FasL level. This cells also influenced differentiation of effector, memory T cell population. The increase in IL10: TNFα ratio, Treg: Th17 ratio and lowering of myeloid DC: plasmacytoid DC ratio was observed. It shifted the overaggressive inflammation mediated Th1 pathway that is reported to incur host damage, to a better well-balanced cytokine profile exhibiting Th2 pathway. Autophagic flux induction within pDC proved to be beneficial in combating malarial pathogenicity.


Assuntos
Autofagia/imunologia , Células Dendríticas/imunologia , Modelos Animais de Doenças , Malária Cerebral/imunologia , Baço/imunologia , Animais , Autofagia/efeitos dos fármacos , Linfócitos T CD8-Positivos/imunologia , Adesão Celular/efeitos dos fármacos , Citocinas/imunologia , Células Dendríticas/parasitologia , Células Dendríticas/patologia , Malária Cerebral/tratamento farmacológico , Malária Cerebral/patologia , Masculino , Camundongos , Sirolimo/administração & dosagem , Sirolimo/farmacologia , Linfócitos T Reguladores/imunologia , Equilíbrio Th1-Th2/efeitos dos fármacos , Células Th17/imunologia
12.
Parasitol Int ; 71: 18-26, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30872003

RESUMO

Splenic red pulp macrophages play a critical role infiltration of infected RBC and elimination of pathogens during malarial infection. However, the efficiency of pathogenic processing and the intricate pathway followed by them to boost the downstream immune response has not been studied in details. We checked the status of autophagic regulation within the cells both before and after the infection and also modulated the autophagic flux with either its inducer or inhibitor. We found that the upregulation of autophagic gene and the corresponding pathway is correlated with better parasite clearance and survivability, with an enhanced downstream immune response. It also increases their phagocytic potential with better Lysosomal associated protein I and II synthesis. The autophagolysosome formation increases as well, and more vacuole bound LC3B protein are detected. Chemokine synthesized from Red Pulp macrophage helps in mediating the induction for recruiting neutrophil and CD4 + T cells to the splenic red pulp region. The skewing of M1 macrophage polarity is observed post autophagic induction with a better costimulatory molecule like CD80, CD86 expression and antigen presenting molecule MHC I, MHC II is observed. This study shows the possibility of an alternative or adjuvant therapy regimen for the malarial patient by inducing the autophagic pathway that targets the red pulp macrophages. This might be helpful for better pathogen degradation and processing. The subsequent clearance of parasite will result in a better outcome for the patients.


Assuntos
Autofagia , Regulação da Expressão Gênica , Macrófagos/parasitologia , Malária Cerebral/imunologia , Baço/imunologia , Animais , Linfócitos T CD4-Positivos/imunologia , Proteína 1 de Membrana Associada ao Lisossomo/genética , Proteína 2 de Membrana Associada ao Lisossomo/genética , Masculino , Camundongos , Proteínas Associadas aos Microtúbulos/genética , Fagocitose , Reação em Cadeia da Polimerase em Tempo Real , Baço/citologia , Regulação para Cima
13.
Phys Chem Chem Phys ; 19(44): 29998-30009, 2017 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-29094124

RESUMO

This work highlights the synthesis of zinc blende ZnxCd1-xS ternary solid solutions with a tunable bandgap. Composition dependent band gaps are realized due to the effective band edge tuning of the solid solutions which in turn show decent photocatalytic behaviour. The bandgap of ZnxCd1-xS increases as Zn composition increases. It is interesting to note that the highest catalytic activity is observed for Zn0.8Cd0.2S (Eg = 2.83 eV) in the visible spectra due to the presence of defect states in the bandgap around 2.35 eV which has been explicated according to the results of photoluminescence spectra. Density of states (DOS) analysis provides further theoretical insight into the more negative conduction band edge for x = 0.8 than other samples. It also determines generation of intermediate states due to sulfur vacancy which is responsible for more electron-hole generation and the highest rate of Methyl Orange (MO) degradation under natural sunlight irradiation.

14.
Cytokine ; 99: 249-259, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28803696

RESUMO

Modulation of pro-inflammatory and anti-inflammatory axis and orientation of glial cell function towards neuroinflammation, were hallmark signs of cerebral malaria (CM). CM pathogenesis was concerned with the circulating levels of Interleukin 6 (IL 6) and Transforming growth factor ß (TGF ß). Definite roles of these two cytokines in brain related pathology remained largely unexplored. To study the effect of these two cytokines, we have examined changes in morphology and in activation profile of the glial cells after TGF ß and IL 6 neutralization during CM in cortex and cerebellum of the Plasmodium berghei ANKA (PbA) infected male swiss albino mice. PbA infection caused severe inflammation by inducing changes in morphological features as well as in activation profile of the astrocytes and microglia. Similar inflammatory signs were evident in Anti TGF ß treated set. Interestingly in the Anti IL 6 treated set, reduced level of activation of these glial cells corresponds to the reduced level of inflammatory profile. Microglial activation was found to be synchronous with TLR4 engagement. Neuronal death was triggered by neuroinflammatory milieu seen in PbA and PbA+Anti TGF ß treated set. In conclusion, it can be said that IL 6 and TGF ß perform essential role in CM pathogenesis by modulating the level of glial cell induced neuroinflammation.


Assuntos
Encéfalo/patologia , Inflamação/patologia , Interleucina-6/metabolismo , Malária Cerebral/patologia , Neuroglia/metabolismo , Plasmodium berghei/fisiologia , Fator de Crescimento Transformador beta/metabolismo , Animais , Apoptose , Astrócitos/metabolismo , Biomarcadores/metabolismo , Antígeno CD11b/metabolismo , Agregação Celular , Proteínas de Ligação a DNA , Proteína Glial Fibrilar Ácida/metabolismo , Mediadores da Inflamação/metabolismo , Malária Cerebral/metabolismo , Masculino , Camundongos , Proteínas do Tecido Nervoso/metabolismo , Neuroglia/patologia , Proteínas Nucleares/metabolismo , Coloração pela Prata , Receptor 4 Toll-Like/metabolismo
15.
ACS Appl Mater Interfaces ; 9(27): 22652-22664, 2017 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-28616963

RESUMO

In this work we have synthesized quaternary chalcogenide Cu2NiSnS4 (QC) nanoparticles grown in situ on 2D reduced graphene oxide (rGO) for application as anode material of solid-state asymmetric supercapacitors (ASCs). Thorough characterization of the synthesized composite validates the proper phase, stoichiometry, and morphology. Detailed electrochemical study of the electrode materials and ASCs has been performed. The as-fabricated device delivers an exceptionally high areal capacitance (655.1 mF cm-2), which is much superior to that of commercial micro-supercapacitors. Furthermore, a remarkable volumetric capacitance of 16.38 F cm-3 is obtained at a current density of 5 mA cm-2 combined with a very high energy density of 5.68 mW h cm-3, which is comparable to that of commercially available lithium thin film batteries. The device retains 89.2% of the initial capacitance after running for 2000 cycles, suggesting its long-term capability. Consequently, the enhanced areal and volumetric capacitances combined with decent cycle stability and impressive energy density endow the uniquely decorated QC/rGO composite material as a promising candidate in the arena of energy storage devices. Moreover, Cu2NiSnS4 being a narrow band gap photovoltaic material, this work offers a novel protocol for the development of self-charging supercapacitors in the days to come.

16.
ACS Appl Mater Interfaces ; 9(27): 22788-22798, 2017 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-28621513

RESUMO

Chemically derived topological insulator Bi2Se3 nanoflake/Si nanowire (SiNWs) heterojunctions were fabricated employing all eco-friendly cost-effective chemical route for the first time. X-ray diffraction studies confirmed proper phase formation of Bi2Se3 nanoflakes. The morphological features of the individual components and time-evolved hybrid structures were studied using field emission scanning electron microscope. High resolution transmission electron microscopic studies were performed to investigate the actual nature of junction whereas elemental distributions at junction, along with overall stoichiometry of the samples were analyzed using energy dispersive X-ray studies. Temperature dependent current-voltage characteristics and variation of barrier height and ideality factor was studied between 50 and 300 K. An increase in barrier height and decrease in the ideality factor were observed with increasing temperature for the sample. The rectification ratio (I+/I-) for SiNWs substrate over pristine Si substrate under dark and near-infrared (NIR) irradiation of 890 nm was found to be 3.63 and 10.44, respectively. Furthermore, opto-electrical characterizations were performed for different light power intensities and highest photo responsivity and detectivity were determined to be 934.1 A/W and 2.30 × 1013 Jones, respectively. Those values are appreciably higher than previous reports for topological insulator based devices. Thus, this work establishes a hybrid system based on topological insulator Bi2Se3 nanoflake and Si nanowire as the newest efficient candidate for advanced optoelectronic materials.

17.
ACS Omega ; 2(8): 4216-4226, 2017 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-31457716

RESUMO

Developing portable, lightweight, and flexible energy storage systems has become a necessity with the advent of wearable electronic devices in our modern society. This work focuses on the fabrication of Co3O4 nanowires on a flexible carbon fabric (CoNW/CF) substrate by a simple cost-effective hydrothermal route. The merits of the high surface area of the prepared Co3O4 nanostructures result in an exceptionally high specific capacitance of 3290 F/g at a scan rate of 5 mV/s, which is close to their theoretical specific capacitance. Furthermore, a solid-state symmetric supercapacitor (SSC) based on CoNW/CF (CoNW/CF//CoNW/CF) was fabricated successfully. The device attains high energy and power densities of 6.7 Wh/kg and 5000 W/kg. It also demonstrates excellent rate capability and retains 95.3% of its initial capacitance after 5000 cycles. Further, the SSC holds its excellent performance at severe bending conditions. When a series assembly of four such devices is charged, it can store sufficient energy to power a series combination of five light-emitting diodes. Thus, this SSC device based on a three-dimensional coaxial architecture opens up new strategies for the design of next-generation flexible supercapacitors.

18.
Cytokine ; 88: 154-166, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27632786

RESUMO

The role of cytokines in Plasmodium infection have been extensively investigated, but pro and anti inflammatory cytokines mediated imbalance during malaria immune-pathogenesis is still unrevealed. Malaria is associated with the circulating levels of Interleukin-6 (IL-6) and transforming growth factor ß (TGF-ß), but association between these two cytokines in immune response remains largely obscured. Using mouse model, we proposed that IL-6 and TGF-ß are involved in immune regulation of dendritic cells (DC), regulatory T cells (Treg), T-helper cells (Th17) during P. berghei ANKA (PbA) infection. Association between the cytokines and the severity of malaria was established with anti-TGF-ß treatment resulting in increased parasitemia and increased immunopathology, whereas; anti-IL-6 treatment delays immunopathology during PbA infection. Further, splenocytes revealed differential alteration of myeloid DC (mDC), plasmocytoid DC (pDC), Treg, Th17 cells following TGF-ß and IL-6 neutralization. Interestingly anti-TGF-ß reduces CD11c+CD8+ DC expression, whereas anti-IL-6 administration causes a profound increase during PbA infection in Swiss mice. We observed down regulation of TGF-ß, IL-10, NFAT, Foxp3, STAT-5 SMAD-3 and upregulation of IL-6, IL-23, IL-17 and STAT-3 in splenocytes during PbA infection. The STAT activity probably plays differential role in induction of Th17 and Treg cells. Interestingly we found increase in STAT-3 and decrease in STAT-5 expression during PbA infection. This pattern of STAT indicates that possibly TGF-ß and IL-6 play a crucial role in differentiation of DCs subsets and Treg/Th17 imbalance during experimental cerebral malaria (ECM).


Assuntos
Células Dendríticas/imunologia , Interleucina-6/imunologia , Malária Cerebral/imunologia , Plasmodium berghei/imunologia , Linfócitos T Reguladores/imunologia , Fator de Crescimento Transformador beta/imunologia , Animais , Células Dendríticas/patologia , Modelos Animais de Doenças , Malária Cerebral/patologia , Masculino , Camundongos , Fatores de Transcrição STAT/imunologia , Linfócitos T Reguladores/patologia , Células Th17/patologia
19.
PLoS One ; 11(2): e0148085, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26859302

RESUMO

Laser refractive surgery for myopia increases the eye's higher-order wavefront aberrations (HOA's). However, little is known about the impact of such optical degradation on post-operative image quality (IQ) of these eyes. This study determined the relation between HOA's and IQ parameters (peak IQ, dioptric focus that maximized IQ and depth of focus) derived from psychophysical (logMAR acuity) and computational (logVSOTF) through-focus curves in 45 subjects (18 to 31 yrs) before and 1-month after refractive surgery and in 40 age-matched emmetropic controls. Computationally derived peak IQ and its best focus were negatively correlated with the RMS deviation of all HOA's (HORMS) (r≥-0.5; p<0.001 for all). Computational depth of focus was positively correlated with HORMS (r≥0.55; p<0.001 for all) and negatively correlated with peak IQ (r≥-0.8; p<0.001 for all). All IQ parameters related to logMAR acuity were poorly correlated with HORMS (r≤|0.16|; p>0.16 for all). Increase in HOA's after refractive surgery is therefore associated with a decline in peak IQ and a persistence of this sub-standard IQ over a larger dioptric range, vis-à-vis, before surgery and in age-matched controls. This optical deterioration however does not appear to significantly alter psychophysical IQ, suggesting minimal impact of refractive surgery on the subject's ability to resolve spatial details and their tolerance to blur.


Assuntos
Olho/fisiopatologia , Ceratomileuse Assistida por Excimer Laser In Situ/efeitos adversos , Adolescente , Adulto , Estudos de Casos e Controles , Aberrações de Frente de Onda da Córnea/etiologia , Aberrações de Frente de Onda da Córnea/fisiopatologia , Humanos , Psicofísica , Controle de Qualidade , Adulto Jovem
20.
Cytokine ; 73(2): 198-206, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25792277

RESUMO

The roles of dendritic cells (DCs) in mediating immunity against Plasmodium infection have been extensively investigated, but immune response during pathogenesis of malaria is still poorly understood. In the present study, we compared the splenic DCs phenotype and function during P. berghei ANKA (PbA) or P. yoelii (P. yoelii) infection in Swiss mice. We observed that PbA-infected mice developed more myeloid and mature DCs capable of secreting IL-12, while P. yoelii-infected mice had more plasmacytoid and immature DCs secreting higher levels of IL-10. Expression of FoxP3, IL-17, TGF-ß and IL-6 were also different between these two infections. Thus, these results suggest that the phenotypic and functional subsets of splenic DCs are key factors for regulating immune responses to PbA and P. yoelii infections.


Assuntos
Células Dendríticas/imunologia , Células Dendríticas/parasitologia , Imunidade , Malária/imunologia , Malária/parasitologia , Plasmodium berghei/fisiologia , Plasmodium yoelii/fisiologia , Animais , Antígenos CD/metabolismo , Contagem de Células , Diferenciação Celular , Fatores de Transcrição Forkhead/metabolismo , Interleucina-10/metabolismo , Interleucina-12/metabolismo , Interleucina-17/metabolismo , Interleucina-6/metabolismo , Estágios do Ciclo de Vida , Masculino , Camundongos , Parasitemia/imunologia , Parasitemia/parasitologia , Plasmodium berghei/crescimento & desenvolvimento , Plasmodium yoelii/crescimento & desenvolvimento , Baço/parasitologia , Baço/patologia , Análise de Sobrevida
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA