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1.
Sci Rep ; 14(1): 13228, 2024 Jun 09.
Artículo en Inglés | MEDLINE | ID: mdl-38853164

RESUMEN

Petroleum fuels are commonly used for automobiles. However, the continuous depletion and exhaust gas emission causes serious problems. So, there is a need for an alternative eco-friendly fuel. Biodiesel is a type of fuel manufactured through a process called transesterification, which involves converting vegetable oils into a usable form. The process parameters of the transesterification process were optimized using the Taguchi method to achieve maximum biodiesel yield. However, the main problem of biodiesel is its high cost which could be reduced by using low-cost feedstock. To address this challenge, biodiesel (BCFAD) is derived from coconut fatty acid distillate (CFAD), a by-product obtained from refining coconut oil. This work uses BCFAD and BCFAD with Alumina nanoparticles as fuels. Alumina nanoparticles in the mass fraction of 25 ppm, 50 ppm, and 100 ppm are dispersed in BCFAD. The investigation results reveal an increase of 6.5% in brake thermal efficiency for BCFAD with 100 ppm nanoparticles when compared to BCFAD. There is a reduction of 29.29% of hydrocarbon and 34% of Carbon monoxide emissions with BCFAD100 in comparison with diesel. However, there is a marginal increase in NOx emission with the increase in nanoparticles. The heat release rate and cylinder pressure of BCFAD100 are comparable to diesel fuel. It was concluded that the utilization of BCFAD with a nanoparticle dispersion of 100 ppm is suitable for direct use as fuel in diesel engines.

2.
Chemistry ; : e202402086, 2024 Jun 12.
Artículo en Inglés | MEDLINE | ID: mdl-38865099

RESUMEN

A multi-stimuli responsive tetraphenyl substituted tripehnylamine-based aggregation induced emissive (AIE) material coupled with spiropyran was prepared. Owing to the presence of AIE and photochromic moiety, the molecule exhibits emissive aggregates, photochromism, and acidochromism. The multiple stimuli sensitive behavior of the molecule was explored for anti-counterfeiting behavior on TLC plate and commercial banknotes. The fluorogenic and photogenic response under UV and visible light established the potential of the candidate as a new generation encryption material.

3.
Int J Oral Maxillofac Surg ; 53(8): 672-676, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38556432

RESUMEN

Bizarre parosteal osteochondromatous proliferations (BPOPs) are distinct clinical-pathological entities that demonstrate combinations of atypical-appearing osseous and chondromatous tissues. These lesions are usually reactive in nature. Histopathologically, 'bizarre' cartilage is a characteristic feature of this lesion. BPOPs usually represent slow-growing painless bony hard protuberances that arise from the surface of affected bone cortices, typically the metacarpals, metatarsals, and phalanges. The occurrence of these lesions in the skull and jaws is sporadic. This case report highlights the clinical presentation, histopathological characteristics, and management of BPOP arising from the supraorbital rim in a 61-year-old female patient.


Asunto(s)
Osteocondroma , Humanos , Femenino , Persona de Mediana Edad , Osteocondroma/patología , Osteocondroma/diagnóstico por imagen , Osteocondroma/cirugía , Diagnóstico Diferencial , Hueso Temporal/patología , Hueso Temporal/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Neoplasias Óseas/patología , Neoplasias Óseas/diagnóstico por imagen , Neoplasias Óseas/cirugía , Biopsia
4.
Curr Cardiol Rev ; 20(2): 50-60, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38367261

RESUMEN

BACKGROUND: Previous publications in 2011, 2016, and 2022 have presented lists of drugs associated with takotsubo cardiomyopathy (TCM). This review aims to provide updated drug lists that have been reported as potential causes of TCM. METHODS: Following the same methodology employed in previous reviews, a detailed investigation was carried out in the PubMed/Medline database from June 2022 to July 2023 to identify drug-induced TCM (DITC) case reports. Various search terms related to the drug-induced transient left ventricular ballooning syndrome, ampulla cardiomyopathy, apical ballooning syndrome, drug-induced broken heart syndrome, drug triggered takotsubo cardiomyopathy, takotsubo cardiomyopathy, and iatrogenic takotsubo cardiomyopathy were utilized. Filters for fulltext availability, case reports, human studies, and English language were applied. Articles reporting drugs associated with TCM development were included in the analysis. RESULTS: Foremost 192 case reports were initially identified, with 75 drugs meeting the inclusion criteria after a thorough review. The latest revision identified seven drugs that might lead to TCM, with four drugs (57.14%) already reported in previous reviews and three drugs (42.86%) newly identified. Consequently, the updated drug list potentially triggering TCM in 2023 comprises a sum of 75 drugs. CONCLUSION: The recent 75 drugs provided additional evidence linking to TCM development. The updated list predominantly includes drugs that induce sympathetic overstimulation, although some drugs on the list have unclear associations with sympathetic nervous system activation.


Asunto(s)
Cardiomiopatía de Takotsubo , Cardiomiopatía de Takotsubo/inducido químicamente , Humanos , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos
5.
Med Chem ; 2023 11 08.
Artículo en Inglés | MEDLINE | ID: mdl-37946342

RESUMEN

Benzimidazole nucleus is a predominant heterocycle displaying a wide spectrum of pharmacological activities. The privileged nature of the benzimidazole scaffold has been revealed by its presence in most small molecule drugs and in its ability to bind multiple receptors with high affinity. A literature review of the scaffold reveals several instances where structural modifications of the benzimidazole core have resulted in high-affinity lead compounds against a variety of biological targets. Hence, this structural moiety offers opportunities to discover novel, better, safe and highly potent biological agents. The goal of the present review is to compile the medicinal properties of benzimidazole derivatives with a focus on SAR (Structure-Activity Relationships).

6.
J Cancer Res Ther ; 19(2): 191-197, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37006057

RESUMEN

Context: Breast cancer is one of the fatal diseases among women. Every year, its incidence and mortality rate increase globally. Mammography and sonography are widely used in breast cancer detection. Because mammography misses many cancers and shows false negatives in the denser tissues, sonography is preferred to give some extra information in addition to that available from mammography. Aims: To improve the performance of breast cancer detection by reducing false positives. Settings and Design: The local binary pattern (LBP) texture features must be extracted from ultrasound elastographic and echographic images of the same patients and then fused to form a single feature vector. Methods and Materials: Local Binary Pattern (LBP) texture features of elastographic and echographic images are extracted, and reduced individually through a hybrid feature selection technique based on binary BAT algorithm (BBA) and optimum path forest (OPF) classifier and then fused serially. Finally, the support vector machine classifier is used to classify the final fused feature set. Statistical Analysis Used: Various relevant performance metrics such as accuracy, sensitivity, specificity, discriminant power, Mathews correlation coefficient (MCC), F1 score, and Kappa were used to analyze the classification results. Results: The use of LBP feature produces 93.2% accuracy, 94.4% sensitivity, 92.3% specificity, 89.5% precision value, 91.88% F1 score, 93.34% balanced classification rate, and Mathews correlation coefficient of 0.861. The performance was compared with gray level co-occurrence matrix (GLCM), gray level difference matrix (GLDM), and LAWs features, and showed that LBP outperformed. Conclusions: Because the specificity is better, this method could be useful for detecting breast cancer with minimum false negatives.


Asunto(s)
Neoplasias de la Mama , Diagnóstico por Imagen de Elasticidad , Femenino , Humanos , Neoplasias de la Mama/diagnóstico por imagen , Neoplasias de la Mama/patología , Ultrasonografía , Mamografía/métodos , Algoritmos , Máquina de Vectores de Soporte
7.
Front Plant Sci ; 14: 1135946, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36890902

RESUMEN

The Last four decades have witnessed the banning of several synthetic insecticides mainly due to the development of resistance to the target pests and due to hazardous effects on humans and the environment. Hence, the development of a potent insecticide with biodegradable and eco-friendly nature is the need of the hour. In the present study, the fumigant property, and biochemical effects of Dillenia indica L. (Dilleniaceae) were studied against three coleopterans stored-products insects. The bioactive enriched fraction (sub-fraction-III) was isolated from ethyl acetate extracts of D. indica leaves and found toxic to rice weevil, Sitophilus oryzae (L.) (Coleoptera); lesser grain borer Rhyzopertha dominica (L.) (Coleoptera) and red flour beetle, Tribolium castaneum (Herbst.) (Coleoptera) with the LC50 values of 101.887, 189.908 and 115.1 µg/L respectively after 24 h exposure. The enriched fraction was found to inhibit the function of acetylcholinesterase (AChE) enzyme when tested against S. oryzae, T. castaneum, and R. dominica with LC50 value of 88.57 µg/ml, 97.07 µg/ml, and 66.31 µg/ml respectively, in in-vitro condition. It was also found that the enriched fraction caused a significant oxidative imbalance in the antioxidative enzyme system such as superoxide dismutase, catalase, DPPH (2,2-diphenyl-1-picrylhydrazyl), and glutathione-S-transferase (GST). GCMS analysis of the enriched fraction indicates three major compounds namely, 6-Hydroxy-4,4,7a-trimethyl-5,6,7,7a-tetrahydrobenzofuran-2(4H)-one, 1,2-Benzisothiazol-3(2H)-one, and Benzothiazole, 2-(2-hydroxyethylthio)-. Finally, we concluded that the enriched fraction of D. indica has insecticidal properties and the toxicity may be due to the inhibition of the AChE enzyme in association with oxidative imbalance created on the insect's antioxidant enzyme systems.

8.
Anaesthesia ; 76(10): 1358-1366, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-33687732

RESUMEN

It is unclear whether the association between vasopressor dose and mortality is affected by duration of administration. We examined whether prognostication in septic shock is feasible through the use of daily median vasopressor doses. We undertook a single-centre retrospective cohort study. We included patients with a diagnosis of septic shock admitted to the intensive care unit at Queen Elizabeth Hospital, Birmingham, UK, between April 2016 and July 2019. The primary outcome measure was 90-day mortality. We defined vasopressor dose as the median norepinephrine equivalent dose (equivalent infusion rates of all vasopressors and inotropes) recorded for each day, for the first four days of septic shock. We divided patients into groups by vasopressor dose quintiles and calculated their 90-day mortality rate. We examined area under the receiver operator characteristic curves for prognostic ability. In total, 844 patients were admitted with septic shock and had a 90-day mortality of 43% (n = 358). Over the first four days, median vasopressor dose decreased in 93% of survivors and increased in 56% of non-survivors. The mortality rate associated with a given vasopressor dose quintile increased on sequential days of septic shock. The area under the receiver operator characteristic curves of daily median vasopressor dose against mortality increased from day 1 to day 4 (0.67 vs. 0.86, p < 0.0001). By day 4, a median daily vasopressor dose > 0.05 µg.kg-1 .min-1 had an 80% sensitivity and specificity for mortality. The prognostic utility of vasopressor dose improved considerably with shock duration. Prolonged administration of small vasopressor doses was associated with a high attributable mortality.


Asunto(s)
Cuidados Críticos/métodos , Norepinefrina/uso terapéutico , Choque Séptico/tratamiento farmacológico , Vasoconstrictores/uso terapéutico , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Cohortes , Relación Dosis-Respuesta a Droga , Femenino , Humanos , Unidades de Cuidados Intensivos , Masculino , Persona de Mediana Edad , Pronóstico , Estudios Retrospectivos , Análisis de Supervivencia , Tiempo , Resultado del Tratamiento , Reino Unido , Adulto Joven
10.
Curr Comput Aided Drug Des ; 17(2): 201-213, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-32003699

RESUMEN

BACKGROUND: Hospital-acquired (HA) infections are caused due to E. coli, which is resistant to multiple drugs particularly to fluoroquinolone class of drugs. Urinary tract infections (UTI) affects people in the community and hospitals. 150 million people per annum are suffering from UTI worldwide. METHODS: In this present study, we designed 36 novel coumarin derivatives, also we predicted pharmacokinetic and toxicity parameters. Docking studies were also carried out and all the compounds were evaluated for antibacterial activity against resistant quinolone E. coli strain ATCC 25922. It was interesting to note that the introduction of electron-withdrawing group on the aromatic ring resulted in compounds with an increased antibacterial activity, which is observed in compound 6 (with 4-nitro substitution), compound 23 (chloro) and compound 30 (chloro, nitro). RESULTS: From the MIC results, it was observed that compounds 6, 23 and 30 showed higher activity with 0.5µg/ml, 0. 12 µg/ml, 0.5 µg/ml respectively. Docking studies were performed with the active site of DNA gyrase (PDB ID: 4CKK). The maximum binding energy was found to be -10.7 Kcal/mol. CONCLUSION: From the study, it was found that 3 compounds were potentially active against quinolone- resistant E. coli strains. This study can further be extended for in vivo evaluation.


Asunto(s)
Antibacterianos/síntesis química , Simulación por Computador , Cumarinas/síntesis química , Diseño de Fármacos/métodos , Simulación del Acoplamiento Molecular/métodos , Antibacterianos/farmacología , Cumarinas/farmacología , Evaluación Preclínica de Medicamentos/métodos , Escherichia coli/efectos de los fármacos , Escherichia coli/fisiología , Humanos , Pruebas de Sensibilidad Microbiana/métodos
11.
Mater Today Proc ; 2020 Nov 19.
Artículo en Inglés | MEDLINE | ID: mdl-33235828

RESUMEN

The present study is about the detailed analysis of the pandemic Corona Virus 2019 which has rocked the entire world with a maximum impact with its structure, its appearance and nomenclature, Clinical presentation and transmission, diagnostic technique. It's a respiratory illness caused by the virus SARS-CoV2 (Severe Acute Respiratory Syndrome). It's a syndrome is different from other virus syndromes as this might act as Symptomatic also as Asymptomatic. The common symptoms would be cold, fever, cough, sneezing, running nose, breathing issues, Fatigue, etc. The paper may be a vivid picture on the COVID 19 cases in Tamilnadu which is within the Southern part of India and therefore the treatments like Ventilator, Plasma, etc and therefore the remedy offered to the patients like Naturopathy, Ayurvedic, Siddha, Unani, Homeopathy, etc,.for better recovery and immunity to fight against the virus. It analyses the detailed reports and statistics during a regression form with reference to daily new death rate and total death rate with the assistance of statistical tools of the general rectilinear regression equation. the entire confirmed cases and daily new confirmed cases are plotted using Normal P-P plot of regression Standardized Residual. The Pearson correlation value is 0.837 which features a strong direct correlation between active cases and total recoveries.

12.
J Maxillofac Oral Surg ; 19(1): 44-46, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-31988562

RESUMEN

The aim of this article is to develop a navigation-guided oral and maxillofacial surgery including surgical planning, simulation and navigation in temporomandibular joint ankylosis case practiced in tertiary care hospital. After getting the computed tomographic angiography of head and neck, the special software of Brain lab® is used to mark the arteries and veins of the patient, which was in close approximation to the mandibular condyle. Brain lab® navigation system was used during the surgery to ascertain the middle meningeal artery location, and osteotomy cut was given. Navigation technology use in the neurosurgery is not new. But its use in the subcontinent in the field of maxillofacial surgery is quite rare. First time, it has been used scientifically in temporomandibular joint ankylosis case. Navigation technology use in the maxillofacial surgery requires a holistic imaginative/creative approach to make the surgeries more predictive and safe.

13.
Indian Heart J ; 71(1): 32-38, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31000180

RESUMEN

BACKGROUND: Despite several decades of use of calcium channel blockers, the side effect of edema persists as a class effect, and its mechanism is unresolved. Amlodipine has effects on hemorheology (HR), and its hemodilutory property may partly contribute to its antihypertensive action. This aspect is not well studied, and the literature is sparse in this regard. OBJECTIVE: This experiment was planned to determine effect of a single-dose administration of amlodipine on HR parameters in normal human volunteers. METHODS AND RESULTS: Amlodipine (5 mg) or S (-) amlodipine (2.5 mg) was administered to 27 normal human volunteers. Whole-blood viscosity (WBV) at different shear rates, plasma viscosity (PV), red cell rigidity (RCR), red cell aggregation (RCA), hematocrit (Hct), plasma hemoglobin, along with plasma drug concentration were determined at time intervals, t = 0, 4, 8, 12, and 24 h. Statistically significant reductions were observed at tmax = 4 h in WBV at shear rates of 0.512 s-1 (p < 0.005), WBV at shear rates of 5.26 s-1 (p < 0.01), PV (p < 0.05), and Hct (p < 0.01). At t = 8 h, as drug concentration reduced, some of the changes persisted and later slowly decreased with the decreasing drug concentration till t = 24 h. Red blood cell-related parameters such as RCA and RCR remained unaltered. WBV values at all shear rates, when corrected for Hct = 0.45, did not show deviation from their original values at any time. CONCLUSIONS: Amlodipine causes a reduction in Hct and blood viscosity, along with hemodilution. These effects persist as long as the drug remains in plasma. Edema resulting from chronic dosing may be explained by the aforementioned effects. It is possible that antihypertensive action of the drug may be due to a combination of vasodilatation and an improvement in the HR properties.


Asunto(s)
Amlodipino/administración & dosificación , Viscosidad Sanguínea/efectos de los fármacos , Edema/sangre , Agregación Eritrocitaria/efectos de los fármacos , Hipertensión/tratamiento farmacológico , Bloqueadores de los Canales de Calcio/administración & dosificación , Relación Dosis-Respuesta a Droga , Edema/tratamiento farmacológico , Edema/etiología , Voluntarios Sanos , Hematócrito , Humanos , Hipertensión/sangre , Hipertensión/complicaciones , Masculino , Método Simple Ciego , Resultado del Tratamiento , Adulto Joven
15.
J Virol ; 92(7)2018 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-29321318

RESUMEN

Flaviviruses are arthropod-borne viruses that constitute a major global health problem, with millions of human infections annually. Their pathogenesis ranges from mild illness to severe manifestations such as hemorrhagic fever and fatal encephalitis. Type I interferons (IFNs) are induced in response to viral infection and stimulate the expression of interferon-stimulated genes (ISGs), including that encoding viperin (virus-inhibitory protein, endoplasmic reticulum associated, IFN inducible), which shows antiviral activity against a broad spectrum of viruses, including several flaviviruses. Here we describe a novel antiviral mechanism employed by viperin against two prominent flaviviruses, tick-borne encephalitis virus (TBEV) and Zika virus (ZIKV). Viperin was found to interact and colocalize with the structural proteins premembrane (prM) and envelope (E) of TBEV, as well as with nonstructural (NS) proteins NS2A, NS2B, and NS3. Interestingly, viperin expression reduced the NS3 protein level, and the stability of the other interacting viral proteins, but only in the presence of NS3. We also found that although viperin interacted with NS3 of mosquito-borne flaviviruses (ZIKV, Japanese encephalitis virus, and yellow fever virus), only ZIKV was sensitive to the antiviral effect of viperin. This sensitivity correlated with viperin's ability to induce proteasome-dependent degradation of NS3. ZIKV and TBEV replication was rescued completely when NS3 was overexpressed, suggesting that the viral NS3 is the specific target of viperin. In summary, we present here a novel antiviral mechanism of viperin that is selective for specific viruses in the genus Flavivirus, affording the possible availability of new drug targets that can be used for therapeutic intervention.IMPORTANCE Flaviviruses are a group of enveloped RNA viruses that cause severe diseases in humans and animals worldwide, but no antiviral treatment is yet available. Viperin, a host protein produced in response to infection, effectively restricts the replication of several flaviviruses, but the exact molecular mechanisms have not been elucidated. Here we have identified a novel mechanism employed by viperin to inhibit the replication of two flaviviruses: tick-borne encephalitis virus (TBEV) and Zika virus (ZIKV). Viperin induced selective degradation via the proteasome of TBEV and ZIKV nonstructural 3 (NS3) protein, which is involved in several steps of the viral life cycle. Furthermore, viperin also reduced the stability of several other viral proteins in a NS3-dependent manner, suggesting a central role of NS3 in viperin's antiflavivirus activity. Taking the results together, our work shows important similarities and differences among the members of the genus Flavivirus and could lead to the possibility of therapeutic intervention.


Asunto(s)
Virus de la Encefalitis Transmitidos por Garrapatas/fisiología , Regulación de la Expresión Génica , Inmunidad Innata , Complejo de la Endopetidasa Proteasomal/metabolismo , Proteínas/metabolismo , Proteolisis , Proteínas no Estructurales Virales/metabolismo , Replicación Viral/fisiología , Virus Zika/fisiología , Células HEK293 , Células HeLa , Humanos , Oxidorreductasas actuantes sobre Donantes de Grupo CH-CH , Complejo de la Endopetidasa Proteasomal/genética , Proteínas/genética , Proteínas/inmunología , ARN Helicasas/genética , ARN Helicasas/inmunología , ARN Helicasas/metabolismo , Serina Endopeptidasas/genética , Serina Endopeptidasas/inmunología , Serina Endopeptidasas/metabolismo , Proteínas no Estructurales Virales/genética , Proteínas no Estructurales Virales/inmunología
16.
Pharm Dev Technol ; 23(8): 806-814, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28814142

RESUMEN

OBJECTIVE: The aim of the study was to enhance the transdermal delivery of diclofenac potassium (DP) from hydrogels by constant voltage iontophoresis (CVI). The other objective was to establish the safety and efficacy of CVI in rats. MATERIALS AND METHODS: Hydrogels of DP were developed using hydroxyethyl cellulose as matrix material and geraniol, l-menthol and thymol as iontophoretic efficiency enhancers (IEE). In vitro permeation of hydrogels under CVI (1.5 V) was performed in Franz diffusion cells across porcine skin. The ability of CVI to deliver therapeutic amount of DP in vivo was assessed in rat paw edema model. RESULTS: CVI significantly (p < 0.05) increased the steady state flux of DP compared to the passive. The hydrogels containing geraniol and l-menthol enhanced the iontophoretic flux of DP by ∼4.75 and ∼4.49 fold, respectively compared to passive control. The in vivo studies indicated that CVI in combination with IEE, significantly reduced (p < 0.05) area under the curve (AUC) of % inflammation compared to passive treatment. An excellent correlation (r = 0.996) was noted between in vitro flux values and AUC of % inflammation. CONCLUSION: The preclinical studies conclusively demonstrated that CVI in combination with IEE's such as geraniol or l-menthol has the potential to safely deliver therapeutic amounts of DP.


Asunto(s)
Antiinflamatorios no Esteroideos/administración & dosificación , Diclofenaco/administración & dosificación , Iontoforesis/métodos , Absorción Cutánea/efectos de los fármacos , Terpenos/farmacología , Monoterpenos Acíclicos , Administración Cutánea , Animales , Antiinflamatorios no Esteroideos/farmacocinética , Antiinflamatorios no Esteroideos/uso terapéutico , Celulosa/análogos & derivados , Diclofenaco/farmacocinética , Diclofenaco/uso terapéutico , Edema/tratamiento farmacológico , Hidrogeles/química , Masculino , Mentol/farmacología , Ratas , Ratas Wistar , Porcinos , Timol/farmacología
17.
Spectrochim Acta A Mol Biomol Spectrosc ; 193: 422-431, 2018 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-29277073

RESUMEN

A new series of Dy3+ doped (30-x)B2O3+30TeO2+20CaCO3+10ZnO+10ZnF2+xDy2O3 (x=0.01, 0.1, 0.5, 1, 2 and 3 in wt%) Zinc calcium tellurofluoroborate glasses were prepared and their structural, luminescence and excited state dynamics have been studied and reported. The structural properties have been characterized through XRD and FTIR studies to confirm the amorphous nature and to explore the presence of fundamental stretching vibrations. The bonding parameters (δ and ß), optical band gap, Urbach's energy, oscillator strengths and Judd-Ofelt (JO) intensity parameters were calculated from the absorption spectra. The JO intensity parameters and the Y/B intensity ratio values have been used to explore the nature of the bonding and asymmetry around the Dy-ligand field environment. The luminescence properties of the present Dy3+ doped glasses have been analyzed through luminescence excited state dynamics and radiative properties such as transition probability (A), stimulated emission cross-section (σPE) branching ratio (ß) and radiative lifetime (τR) values. The combination of dominant blue (4F9/2→6H15/2) and yellow (4F9/2→6H13/2) emissions generates white light emission in the CIE chromaticity diagram thus suggests that the present Dy3+ doped glasses are suitable for white light applications. The lifetime of the 4F9/2 excited state is found to decrease with the increase in Dy3+ ion content and the concentration quenching of the Dy3+ ions emission could be ascribed due to the resonant energy transfer and cross-relaxation processes. The non-exponential behavior of the decay curves has been analyzed with Inokuti-Hirayama model and the interaction between the Dy3+ ions is of electric dipole-dipole in nature.

18.
Virology ; 514: 216-229, 2018 01 15.
Artículo en Inglés | MEDLINE | ID: mdl-29202415

RESUMEN

Junín arenavirus infections are associated with high levels of interferons in both severe and fatal cases. Upon Junín virus (JUNV) infection a cell signaling cascade initiates, that ultimately attempts to limit viral replication and prevent infection progression through the expression of host antiviral proteins. The interferon stimulated gene (ISG) viperin has drawn our attention as it has been highlighted as an important antiviral protein against several viral infections. The studies of the mechanistic actions of viperin have described important functional domains relating its antiviral and immune-modulating actions through cellular lipid structures. In line with this, through silencing and overexpression approaches, we have identified viperin as an antiviral ISG against JUNV. In addition, we found that lipid droplet structures are modulated during JUNV infection, suggesting its relevance for proper virus multiplication. Furthermore, our confocal microscopy images, bioinformatics and functional results also revealed viperin-JUNV protein interactions that might be participating in this antiviral pathway at lipid droplet level. Altogether, these results will help to better understand the factors mediating innate immunity in arenavirus infection and may lead to the development of pharmacological agents that can boost their effectiveness thereby leading to new treatments for this viral disease.


Asunto(s)
Fiebre Hemorrágica Americana/inmunología , Virus Junin/fisiología , Gotas Lipídicas/virología , Proteínas/inmunología , Fiebre Hemorrágica Americana/genética , Fiebre Hemorrágica Americana/virología , Humanos , Interferones/genética , Interferones/inmunología , Virus Junin/química , Virus Junin/genética , Virus Junin/inmunología , Gotas Lipídicas/inmunología , Nucleoproteínas/química , Nucleoproteínas/genética , Nucleoproteínas/inmunología , Oxidorreductasas actuantes sobre Donantes de Grupo CH-CH , Dominios Proteicos , Proteínas/química , Proteínas/genética , Replicación Viral
19.
J Biol Chem ; 292(33): 13879-13889, 2017 08 18.
Artículo en Inglés | MEDLINE | ID: mdl-28615450

RESUMEN

Viperin (RSAD2) is an interferon-stimulated antiviral protein that belongs to the radical S-adenosylmethionine (SAM) enzyme family. Viperin's iron-sulfur (Fe/S) cluster is critical for its antiviral activity against many different viruses. CIA1 (CIAO1), an essential component of the cytosolic iron-sulfur protein assembly (CIA) machinery, is crucial for Fe/S cluster insertion into viperin and hence for viperin's antiviral activity. In the CIA pathway, CIA1 cooperates with CIA2A, CIA2B, and MMS19 targeting factors to form various complexes that mediate the dedicated maturation of specific Fe/S recipient proteins. To date, however, the mechanisms of how viperin acquires its radical SAM Fe/S cluster to gain antiviral activity are poorly understood. Using co-immunoprecipitation and 55Fe-radiolabeling experiments, we therefore studied the roles of CIA2A, CIA2B, and MMS19 for Fe/S cluster insertion. CIA2B and MMS19 physically interacted with the C terminus of viperin and used CIA1 as the primary viperin-interacting protein. In contrast, CIA2A bound to viperin's N terminus in a CIA1-, CIA2B-, and MMS19-independent fashion. Of note, the observed interaction of both CIA2 isoforms with a single Fe/S target protein is unprecedented in the CIA pathway. 55Fe-radiolabeling experiments with human cells depleted of CIA1, CIA2A, CIA2B, or MMS19 revealed that CIA1, but none of the other CIA factors, is predominantly required for 55Fe/S cluster incorporation into viperin. Collectively, viperin maturation represents a novel CIA pathway with a minimal requirement of the CIA-targeting factors and represents a new paradigm for the insertion of the Fe/S cofactor into a radical SAM protein.


Asunto(s)
Proteínas Portadoras/metabolismo , Proteínas Hierro-Azufre/metabolismo , Metalochaperonas/metabolismo , Modelos Biológicos , Proteínas Nucleares/metabolismo , Proteínas/metabolismo , Factores de Transcripción/metabolismo , Sustitución de Aminoácidos , Apoproteínas/química , Apoproteínas/genética , Apoproteínas/metabolismo , Proteínas Portadoras/antagonistas & inhibidores , Proteínas Portadoras/química , Proteínas Portadoras/genética , Células HEK293 , Humanos , Inmunoprecipitación , Hierro/química , Hierro/metabolismo , Radioisótopos de Hierro , Proteínas Hierro-Azufre/química , Proteínas Hierro-Azufre/genética , Metalochaperonas/antagonistas & inhibidores , Metalochaperonas/química , Metalochaperonas/genética , Metaloproteínas , Mutación , Proteínas Nucleares/antagonistas & inhibidores , Proteínas Nucleares/química , Proteínas Nucleares/genética , Oxidorreductasas actuantes sobre Donantes de Grupo CH-CH , Fragmentos de Péptidos/química , Fragmentos de Péptidos/genética , Fragmentos de Péptidos/metabolismo , Dominios y Motivos de Interacción de Proteínas , Proteínas/química , Proteínas/genética , Interferencia de ARN , Proteínas Recombinantes de Fusión/química , Proteínas Recombinantes de Fusión/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Factores de Transcripción/antagonistas & inhibidores , Factores de Transcripción/química , Factores de Transcripción/genética
20.
Spectrochim Acta A Mol Biomol Spectrosc ; 136 Pt C: 1684-97, 2015 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-25459733

RESUMEN

A new series of white light emitting Dy(3+) doped Lead tellurofluoroborate glasses have been prepared and their spectroscopic and energy transfer behavior were explored through analyzing XRD, FTIR, Raman, SEM, EDAX, optical absorption, photoluminescence and lifetime measurements. The fundamental stretching of the various borate and tellurite networks were identified using FTIR and Raman spectral analysis. The bonding parameter studies reveal the ionic nature of the DyO bond in the present glasses. The Judd-Ofelt (JO) intensity parameters determined from the absorption spectra have been used to investigate the nature of bonding and symmetry orientation of the Dy-ligand field environment. The luminescence intensity increases with increasing Dy(3+) ion concentration up to 0.5wt%, beyond that luminescence quenching is observed. The JO parameters have been used to determine the transition probability (A), stimulated emission cross-section (σP(E)), radiative lifetime (τR) and branching ratios (ßR) for the different emission transitions from the (4)F9/2 excited level. The higher σP(E) and ßR values of the (4)F9/2→(6)H15/2 and (4)F9/2→(6)H13/2 transitions suggest the possible laser action in the visible region. The Y/B ratio, CIE chromaticity color coordinates (x, y) and Color correlated temperature (CCT) were also estimated from the luminescence spectra for different concentration as well as pumping wavelengths. The x, y chromaticity color coordinates fall within the white light region and the white light can be tuned by varying the excitation wavelengths. The lifetime of the (4)F9/2 excited state were measured and is found to decrease with increasing Dy(3+) ion content. The non-exponential behavior is predominant in higher Dy(3+) ion content glasses and is due to the efficient energy transfer between Dy(3+)Dy(3+) ions. The decay curves were fitted to the Inokuti-Hirayama (IH) model to understand the nature of energy transfer. Among the prepared glasses, 0.5DPTFB glass possesses higher A,ßR,σP(E),η values and is suggested for lasers and WLED applications.

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