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1.
Clin Oncol (R Coll Radiol) ; 36(6): e137-e145, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38565457

RESUMO

AIMS: Sinonasal teratocarcinosarcomas (SNTCS) are rare sinonasal malignancies, the incidence of which is less than 1% of all tumors. There is limited data available on SNTCS's, often as case reports and small case series. The management of SNTCS is complicated because of its location, locally aggressive biology, difficulty in achieving complete resection, and limited data on chemotherapy in these malignancies. This audit was performed to understand the role of neoadjuvant chemotherapy (NACT) in SNTCS's, its ability to downstage the disease, achieve complete resection, and impact on long-term survival outcomes. METHODS: This was a retrospective analysis of a prospectively maintained database approved by the Institutional Ethics Committee (IEC). The baseline characteristics, the extent of tumor, Kadish stage, NACT regimen, and adverse events were extracted from the Electronic Medical Records and the patient's case file. Patients with baseline extensive/inoperable disease were referred for NACT from the multidisciplinary joint clinic followed by response assessment (RECIST v1.1). Patients underwent skull-base surgery if respectable post-completion of NACT, however, if deemed unresectable were treated with non-surgical modalities or palliative therapies. RESULTS: The data of 27 patients were evaluated from the year 2015-2022. The median age was 42 years (IQR:30-56) and 85.2% (n = 23) were males. The ECOG-PS was 0-1 in 88.8% (n = 24) patients. All 27 patients received NACT in view of extensive disease at presentation. 74.1% (n = 20) patients received Cisplatin-Etoposide and 25.9% (n = 7) received other chemotherapy regimens. The median number of chemotherapy cycles was 2(IQR:2-3). 96.3% patients (n = 26) completed the planned NACT cycles. 70.4% (n = 19) patients achieved a partial response in post-NACT imaging. 77.8% (n = 18) underwent surgery, 18.5% (n = 5) received CTRT, and 7.4% (n = 2) received definitive-RT alone. The median PFS and OS of the cohort was 19months (95%CI:12.0-25.6) and 23months (95%CI:5.94-40.06) respectively. CONCLUSION: NACT is safe, feasible, and effective with significant response rates, leading to effective downstaging, resectability and improved survival in patients with locally advanced SNTCS's.


Assuntos
Carcinossarcoma , Terapia Neoadjuvante , Neoplasias Nasais , Centros de Atenção Terciária , Humanos , Masculino , Feminino , Estudos Retrospectivos , Índia , Adulto , Pessoa de Meia-Idade , Terapia Neoadjuvante/métodos , Carcinossarcoma/tratamento farmacológico , Carcinossarcoma/terapia , Carcinossarcoma/patologia , Neoplasias dos Seios Paranasais/tratamento farmacológico , Neoplasias dos Seios Paranasais/terapia , Neoplasias dos Seios Paranasais/patologia , Teratoma/tratamento farmacológico , Teratoma/terapia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Idoso , Quimioterapia Adjuvante/métodos
2.
NPJ Regen Med ; 9(1): 7, 2024 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-38280914

RESUMO

Injuries to skeletal muscle are among the most common injuries in civilian and military populations, accounting for nearly 60% of extremity injuries. The standard of care for severe extremity injury has been focused upon limb salvage procedures and the utilization of tissue grafts or orthotics in conjunction with rehabilitation to avoid amputation. Nonetheless, many patients have persistent strength and functional deficits that permanently impact their quality of life. Preclinical and clinical studies have shown that partial restoration of functional skeletal muscle tissue following injury can be achieved by the implantation of a biologic scaffold composed of extracellular matrix (ECM). These favorable outcomes are mediated, at least in part, through local immunomodulation. The mechanisms underlying this immunomodulatory effect, however, are poorly understood. The present study investigates a potential mechanistic driver of the immunomodulatory effects; specifically, the effect of selected ECM components upon inflammation resolution and repair. Results show that the host response to skeletal muscle injury is profoundly altered and functional recovery decreased in il33-/- mice compared to age- and sex-matched wildtype counterparts by 14 days post-injury. Results also show that IL-33, contained within matrix-bound nanovesicles (MBV), supports skeletal muscle regeneration by regulating local macrophage activation toward a pro-remodeling phenotype via canonical and non-canonical pathways to improve functional recovery from injury compared to untreated il33-/- counterparts. Taken together, these data suggest that MBV and their associated IL-33 cargo represent a novel homeostatic signaling mechanism that contributes to skeletal muscle repair.

3.
Clin Radiol ; 78(2): 137-149, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36241568

RESUMO

Radiogenomics refers to the study of the relationship between imaging phenotypes and gene expression patterns/molecular characteristics, which might allow improved diagnosis, decision-making, and predicting patient outcomes in the context of multiple diseases. Central nervous system (CNS) tumours contribute to significant cancer-related mortality in the present age. Although historically CNS neoplasms were classified and graded based on microscopic appearance, there was discordance between two histologically similar tumours that showed varying prognosis and behaviour, attributable to their molecular signatures. These led to the incorporation of molecular markers in the classification of CNS neoplasms. Meanwhile, advancements in imaging technology such as diffusion-based imaging (including tractography), perfusion, and spectroscopy in addition to the conventional imaging of glial neoplasms, have opened an avenue for radiogenomics. This review touches upon the schema of the current classification of gliomas, concepts behind molecular markers, and parameters that are used in radiogenomics to characterise gliomas and the role of artificial intelligence for the same. Further, the role of radiomics in the grading of brain tumours, prediction of treatment response and prognosis has been discussed. Use of automated and semi-automated tumour segmentation for radiotherapy planning and follow-up has also been discussed briefly.


Assuntos
Neoplasias Encefálicas , Neoplasias do Sistema Nervoso Central , Glioma , Humanos , Inteligência Artificial , Glioma/diagnóstico por imagem , Glioma/genética , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Diagnóstico por Imagem
4.
J Ayurveda Integr Med ; 13(3): 100605, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35868134

RESUMO

Fatty Liver, one of the most common liver diseases worldwide, usually emerges due to lipid accumulation, mostly triglycerides in hepatocytes. Fat exists in the liver naturally, but if it surpasses 5-10% of the liver's total weight, it can result in fatty liver. In this case, report effect of Ayurveda intervention in grade II fatty liver is reported. Thirty-five-year-old obese male with grade II fatty liver presented with fatigue, abdominal pain, heaviness, and incomplete bowel evacuation to the National Institute of Ayurveda hospital, Jaipur, Rajasthan, India. On examination, there was no significant clinical abnormality except a high body mass index (BMI = 30.2). Hematological examinations revealed altered Alanine transaminase, fasting blood glucose, total cholesterol, low-density lipoprotein, and triglycerides. The patient was diagnosed sonologically with a grade II fatty liver. The patient was given Ayurveda treatment for two months with three treatment regimens. The patient was assessed for improvement in signs and symptoms, hematological parameters, and quality of life using a chronic liver disease questionnaire (CLDQ). After two months, significant improvement was observed in signs and symptoms, BMI (24.7), and CLDQ. No fatty tissue was reported sonologically, and all altered biochemical parameters were within normal limits. Present case highlights the potential of Ayurveda interventions in managing non-alcoholic fatty liver disease and obesity.

5.
Immunohematology ; 37(4): 160-164, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34964314

RESUMO

Individuals with the rare para-Bombay phenotype have inherited defects in producing H associated with FUT1 and/or FUT2 genes. We report a case of blood group discrepancy in a para-Bombay patient from a tertiary care hospital of eastern India. A 31-year-old woman with rheumatic heart disease presented with fatigue and breathlessness and was then scheduled for valvuloplasty, for which a blood transfusion request was sent to the blood center. During pre-transfusion testing, red blood cell (RBC) testing showed group O, and serum testing showed strong reactivity with group B RBCs, weak reactivity with group O RBCs, and very weak reactivity with group A RBCs. Saliva inhibition testing and enzyme treatment of RBCs concluded the patient to be of "Ah para-Bombay" phenotype. The patient's Lewis phenotype was Le(a-b+). This patient's serum also had cold-reacting anti-IH along with anti-B. This case report highlights the importance of performing an advanced immunohematologic workup, including adsorption, elution, enzyme treatment, and saliva inhibition testing for identification of weak A or B subgroups as well as the rare para-Bombay blood group, when routine ABO typing, using forward and reverse grouping, is inconclusive. Accurate identification of blood group helps in preventing transfusion-related adverse events and encouraging safe transfusion practice.Individuals with the rare para-Bombay phenotype have inherited defects in producing H associated with FUT1 and/or FUT2 genes. We report a case of blood group discrepancy in a para-Bombay patient from a tertiary care hospital of eastern India. A 31-year-old woman with rheumatic heart disease presented with fatigue and breathlessness and was then scheduled for valvuloplasty, for which a blood transfusion request was sent to the blood center. During pre-transfusion testing, red blood cell (RBC) testing showed group O, and serum testing showed strong reactivity with group B RBCs, weak reactivity with group O RBCs, and very weak reactivity with group A RBCs. Saliva inhibition testing and enzyme treatment of RBCs concluded the patient to be of "Ah para-Bombay" phenotype. The patient's Lewis phenotype was Le(a­b+). This patient's serum also had cold-reacting anti-IH along with anti-B. This case report highlights the importance of performing an advanced immunohematologic workup, including adsorption, elution, enzyme treatment, and saliva inhibition testing for identification of weak A or B subgroups as well as the rare para-Bombay blood group, when routine ABO typing, using forward and reverse grouping, is inconclusive. Accurate identification of blood group helps in preventing transfusion-related adverse events and encouraging safe transfusion practice.


Assuntos
Sistema ABO de Grupos Sanguíneos , Tipagem e Reações Cruzadas Sanguíneas , Sistema ABO de Grupos Sanguíneos/genética , Adulto , Transfusão de Sangue , Eritrócitos , Feminino , Fucosiltransferases/genética , Humanos , Fenótipo
6.
Water Sci Technol ; 84(10-11): 2760-2779, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34850692

RESUMO

This study aims to identify the water flux in an earth dam using heat flux due to convection. Sixteen earth dam models were constructed in a hydraulic flume by varying geometrical and flow input parameters to identify heat and water flux. Homogeneous as well as earth dams with clay cores were built in a hydraulic flume. Temperature measurements were done to calculate heat flux in the experimental model. A finite element model of the earth dam using Seep/w was developed to obtain water flux, while temp/w was used to obtain heat flux. These results were used as input in Temp/w and Seep/w in Geostudio 2020. Significant reduction of the heat and water flux was seen while comparing the homogeneous models with central impervious core models. An increase in the heat and water flux was observed on increasing the downstream filter's length, longitudinal slope, and vice versa with the upstream slope and the thickness of the clay core. Comparing fluxes in a homogeneous dam model (model 1) with the clay core model (model 9) with top width 2.4 m and bottom width 18 m in model 9, both water flux and heat flux were reduced by 78.46%. While comparing it with model 10, with bottom core width of 18 m and top core width of 1.9 m, both water flux and heat flux reduced by 77.72%. Heat flux measurements were found to be a valuable alternative to detecting water flux and seepage in an earth dam at a reduced cost.


Assuntos
Temperatura Alta , Água , Convecção , Modelos Teóricos , Movimentos da Água
7.
QJM ; 114(7): 455-463, 2021 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-34347106

RESUMO

BACKGROUND: Corticosteroids have become the mainstay treatment in severe COVID-19. However, its role is mild disease is controversial due to lack of robust scientific evidence. This systematic review and meta-analysis were conducted to assess effect of steroids in mild COVID-19 patients. METHODS: PubMed, EMBASE, Web of Science and medRxiv were searched from 31 December 2019 to 14 May 2021 for studies that reported effectiveness of steroids in non-oxygen requiring COVID-19 patients in terms of progressing to severe disease, mortality, duration of fever, duration of viral clearance and length of hospital stay (LOHS). Studies on inhalational steroids, case reports and reviews were excluded. Risk of bias (ROB) was assessed by the Cochrane's ROB tool and ROBANS tool. Quantitative data synthesis was done using the generic inverse variance method. RESULTS: A total of 6411 studies were identified, 2990 articles were screened after exclusion. Seven studies which fit the criteria (involving 2214 non-oxygen requiring COVID-19 patients) were included and analysed. Overall odds of progression to severe disease among the non-oxygen requiring COVID-19 patients receiving steroids was 5.97 [95% confidence interval (CI): 1.27-27.99, I2 = 0%] and odds of death (OR: 1.35, 95% CI: 1.01-1.79; I2 = 0%) as compared to the patients not receiving steroids. Mean duration of fever (7.4 days), duration to viral clearance (18.9 days) and LOHS (20.8 days) were significantly higher in the steroid arm, as compared to that in no-steroid arm (6.7, 16.5 and 15.2 days, respectively). CONCLUSION: Steroids in non-oxygen requiring COVID-19 patients can be more detrimental than beneficial. PROTOCOL REGISTRATION: The study was prospectively registered in PROSPERO (CRD 42021254951).


Assuntos
COVID-19 , Corticosteroides/uso terapêutico , Humanos , Tempo de Internação , SARS-CoV-2 , Esteroides
8.
QJM ; 114(7): 464-470, 2021 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-34254132

RESUMO

BACKGROUND: Mucormycosis (MM) is a deadly opportunistic fungal infection and a large surge in COVID-19-associated mucormycosis (CAM) is occurring in India. AIM: Our aim was to delineate the clinico-epidemiological profile and identify risk factors of CAM patients presenting to the Emergency Department (ED). DESIGN: This was a retrospective, single-centre, observational study. METHODS: We included patients who presented with clinical features or diagnosed MM and who were previously treated for COVID-19 in last 3 months of presentation (recent COVID-19) or currently being treated for COVID-19 (active COVID-19). Information regarding clinical features of CAM, possible risk factors, examination findings, diagnostic workup including imaging and treatment details were collected. RESULTS: Seventy CAM patients (median age: 44.5 years, 60% males) with active (75.7%) or recent COVID-19 (24.3%) who presented to the ED in between 6 May 2021 and 1 June 2021, were included. A median duration of 20 days (interquartile range: 13.5-25) was present between the onset of COVID-19 symptoms and the onset of CAM symptoms. Ninety-three percent patients had at least one risk factor. Most common risk factors were diabetes mellitus (70%) and steroid use for COVID-19 disease (70%). After clinical, microbiological and radiological workup, final diagnosis of rhino-orbital CAM was made in most patients (68.6%). Systemic antifungals were started in the ED and urgent surgical debridement was planned. CONCLUSION: COVID-19 infection along with its medical management have increased patient susceptibility to MM.


Assuntos
COVID-19 , Mucormicose , Adulto , Serviço Hospitalar de Emergência , Feminino , Humanos , Masculino , Mucormicose/diagnóstico , Mucormicose/epidemiologia , Estudos Retrospectivos , SARS-CoV-2
9.
Br J Biomed Sci ; 78(4): 177-183, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33740392

RESUMO

Background: Chronic obstructive pulmonary disease (COPD) and asthma are obstructive lung diseases which progress in severity with time. Environmental causes and genetic makeup of individuals play important roles in disease manifestation. The aim of present study was to search for diagnostic/prognostic biomarkers to differentiate COPD and asthma.Materials and methods: Seven ADAM33 and two AQP5 single-nucleotide polymorphisms (SNPs) were genotyped by polymerase chain reaction-restriction fragment length polymorphism method. The association of genotypes, haplotypes and allelic combination of variants in different genes was analyzed in 194 COPD, 150 asthma patients and 220 controls.Results: The genotype frequencies of SNPs V4(C/G), T1(T/C), S2(G/C) of ADAM33 and AQP5 A/G (rs3736309) were associated with COPD and asthma (P=0.038 to P<0.001), while S1(A/G) and F+1(C/T) were associated with asthma (both P<0.001) and V1(G/T) with 20 COPD (P<0.001). The allele frequencies of V4(C/G) (both P<0.001), V1(G/T) (both P<0.05), S2(G/C) (both P<0.01) and S1(A/G) (both P<0.05) were associated with COPD and asthma, while F+1(C/T) was associated only with asthma (P=0.005). Haplotypes of ADAM33 'GGTGGGT' (P=0.027), 'CGTCGGC' (P<0.001) and AQP5 'GA' and 'AG' (both P<0.001) were significant only in COPD.Conclusion: ADAM33 F+1(C/T) variant and allele combination 'GGTGGGTGA' may be specific markers for asthma, while AQP5 'AG' appeared as a haplotype associated only with COPD. These specific genetic biomarkers may be exploited to predict individual predisposition to COPD and asthma.


Assuntos
Proteínas ADAM , Aquaporina 5/genética , Asma , Doença Pulmonar Obstrutiva Crônica , Proteínas ADAM/genética , Asma/genética , Estudos de Casos e Controles , Predisposição Genética para Doença , Humanos , Polimorfismo de Nucleotídeo Único , Doença Pulmonar Obstrutiva Crônica/genética
10.
J Colloid Interface Sci ; 572: 198-206, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32244080

RESUMO

In the present work, the three-dimensional ultra-fine platinum nanoflowers are directly deposited on carbon-coated gas diffusion layer electrode (C-GDL) by a single-step electrodeposition method towards the application of polymer electrolyte fuel cells. The surface morphology, particle size distribution, crystallinity, and chemical oxidation state of platinum nanoflowers are examined using various techniques. The morphological features of the Pt nanostructures are highly influenced by the difference in current density. Notabely, the Pt nanospheres converts into three-dimensional nanoflower with an increase in current density from -1.6 to -32 mA cm-2. Electrodeposited Pt catalyst on C-GDL as the cathode catalyst was fabricated and steady-state polarization studies were carried out. Mainly, the fuel cell performance is analysed considering the electrodeposited Pt morphology. Among the prepared electrocatalysts, the nanoflower shaped Pt catalyst exhibit a high peak power density of 660 mW cm-2 at 0.6 V in PEFC.

11.
Gene ; 731: 144356, 2020 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-31935504

RESUMO

The genetic basis of differential host immune response vis-à-vis transcriptome profile was explored in PBMCs of indigenous (Ghurrah) and crossbred pigs after classical swine fever vaccination and in monocyte derived macrophages (MDMs) challenged with virulent classical swine fever (CSF) virus. The humoral immune response (E2 antibody) was higher (74.87%) in crossbred than indigenous pigs (58.20%) at 21st days post vaccination (21dpv). The rate of reduction of ratio of CD4+/CD8+ was higher in crossbred pigs than indigenous pigs at 7th days post vaccination (7dpv). The immune genes IFIT1, IFIT5, RELA, NFKB2, TNF and LAT2 were up regulated at 7dpv in RNA seq data set and was in concordance during qRT-PCR validation. The Laminin Subunit Beta 1 (LAMB1) was significantly (p ≤ 0.05) down-regulated in MDMs of indigenous pigs and consequently a significantly (p ≤ 0.01) higher copy number of virulent CSF virus was evidenced in macrophages of crossbred pigs than indigenous pigs. Activation of LXR:RXR pathway at 60 h post infection (60hpi) in MDMs of indigenous versus crossbred pigs inhibited nuclear translocation of NF-κB, resulted into transrepression of proinflammatory genes. But it helped in maintenance of HDL level by lowering down cholesterol/LDL level in MDMs of indigenous pigs. The key immune genes (TLR2, TLR4, IL10, IL8, CD86, CD54, CASP1) of TREM1 signaling pathway were upregulated at 7dpv in PBMCs but those genes were downregulated at 60hpi in MDMs indigenous pigs. Using qRT-PCR, the validation of differentially expressed, immunologically important genes (LAMB1, OAS1, TLR 4, TLR8 and CD86) in MDMs revealed that expression of these genes were in concordance with RNA-seq data.


Assuntos
Peste Suína Clássica/genética , Leucócitos Mononucleares/metabolismo , Macrófagos/metabolismo , Suínos , Transcriptoma , Animais , Células Cultivadas , Peste Suína Clássica/sangue , Peste Suína Clássica/imunologia , Peste Suína Clássica/prevenção & controle , Vírus da Febre Suína Clássica/imunologia , Vírus da Febre Suína Clássica/fisiologia , Estudo de Associação Genômica Ampla/veterinária , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/imunologia , Hibridização Genética/fisiologia , Imunidade Celular/genética , Imunidade Humoral/genética , Leucócitos Mononucleares/patologia , Leucócitos Mononucleares/virologia , Macrófagos/patologia , Macrófagos/virologia , Suínos/genética , Suínos/imunologia , Suínos/metabolismo , Suínos/virologia
12.
Zygote ; 27(4): 203-213, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31296276

RESUMO

The present study investigated if the presence of encircling granulosa cells protected against di(2-ethylhexyl)phthalate (DEHP)-induced oxidative stress in rat oocytes cultured in vitro. Denuded oocytes and cumulus-oocyte complexes (COCs) were treated with or without various doses of DEHP (0.0, 25.0, 50.0, 100, 200, 400 and 800 µM) in vitro. Morphological apoptotic changes, levels of oxidative stress and reactive oxygen species (ROS), mitochondrial membrane potential, and expression levels of apoptotic markers (Bcl2, Bax, cytochrome c) were analyzed. Our results showed that DEHP induced morphological apoptotic changes in a dose-dependent manner in denuded oocytes cultured in vitro. The effective dose of DEHP (400 µg) significantly (P>0.05) increased oxidative stress by elevating ROS levels and the mitochondrial membrane potential with higher mRNA expression and protein levels of apoptotic markers (Bax, cytochrome c). Encircling granulosa cells protected oocytes from DEHP-induced morphological changes, increased oxidative stress and ROS levels, as well as increased expression of apoptotic markers. Taken together our data suggested that encircling granulosa cells protected oocytes against DEHP-induced apoptosis and that the presence of granulosa cells could act positively towards the survival of oocytes under in vitro culture conditions and may be helpful during assisted reproductive technique programmes.


Assuntos
Proteínas Reguladoras de Apoptose/metabolismo , Apoptose/fisiologia , Células da Granulosa/fisiologia , Oócitos/fisiologia , Animais , Apoptose/efeitos dos fármacos , Apoptose/genética , Proteínas Reguladoras de Apoptose/genética , Células Cultivadas , Dietilexilftalato/toxicidade , Feminino , Expressão Gênica/efeitos dos fármacos , Células da Granulosa/citologia , Potencial da Membrana Mitocondrial/fisiologia , Oócitos/citologia , Oócitos/metabolismo , Estresse Oxidativo/fisiologia , Plastificantes/toxicidade , Ratos , Espécies Reativas de Oxigênio/metabolismo
13.
Water Sci Technol ; 79(3): 458-465, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30924800

RESUMO

The goal of this study was to investigate what kind of impact the removal of particulate organic matter with 33µm rotating belt filter (RBF) (as a primary treatment) will have on the membrane bioreactor (MBR) performance. Two small MBR pilot plants were operated in parallel, where one train treated 2mm screened municipal wastewater (Train A) and the other train treated wastewater that had passed through a RBF with a 33µm filter cloth (Train B). The RBF was operated without a filter mat on the belt. About one third of the organic matter was removed by the fine mesh filter. The assessment of the overall performance showed that the two pilot plants achieved approximately the same removal efficiencies with regard to total suspended solids (TSS), chemical oxygen demand (COD), total phosphorus and total nitrogen. It was also observed that the system with 33µm RBF as a primary treatment produced more sludge, which could be used for biogas production, and required about 30% less aeration downstream. Transmembrane pressure was significantly lower for the train receiving 33µm primary treated wastewater compared to the control receiving 2mm screened wastewater.


Assuntos
Reatores Biológicos , Membranas Artificiais , Nitrogênio/análise , Eliminação de Resíduos Líquidos/métodos , Poluentes da Água/análise , Desnitrificação , Águas Residuárias
14.
Nanoscale Adv ; 1(12): 4926-4937, 2019 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-36133132

RESUMO

Herein, fluorine enrichment in mesoporous carbon (F-MC) was explored to introduce maximum charge polarization in the porous matrix, which is beneficial for the preferential orientation of O2 molecules and their subsequent reduction. Ex situ doping of F to porous carbon derived from phloroglucinol-formaldehyde resin using Pluronic F-127 as a structure-directing agent is standardized. The optimized F-MC catalyst exhibited excellent electrocatalytic activity towards the oxygen reduction reaction (ORR) in alkaline media (0.1 M KOH) with an onset potential of -0.10 V vs. SCE and diffusion-limiting current of 4.87 mA cm-2, while displaying only about 50 mV overpotential in the half-wave region compared to Pt-C (40 wt%). In the stability test, the catalyst showed only 10 mV negative shift in its half-wave potential after 10 000 potential cycles. The rotating ring disk electrode (RRDE) experiments revealed that F-MC follows the most preferable 4e - pathway (n = 3.61) with a moderate peroxide (HO2 -) yield. This was further supported by density functional theory calculations and also deeply explains the existence of defects being beneficial for the ORR. The F-MC catalyst owing to its promising ORR activity and long-term electrochemical stability can be viewed as a potential alternative ORR catalyst for anion exchange membrane fuel cell applications.

15.
Nat Commun ; 9(1): 4859, 2018 11 19.
Artigo em Inglês | MEDLINE | ID: mdl-30451844

RESUMO

While young muscle is capable of restoring the original architecture of damaged myofibers, aged muscle displays a markedly reduced regeneration. We show that expression of the "anti-aging" protein, α-Klotho, is up-regulated within young injured muscle as a result of transient Klotho promoter demethylation. However, epigenetic control of the Klotho promoter is lost with aging. Genetic inhibition of α-Klotho in vivo disrupted muscle progenitor cell (MPC) lineage progression and impaired myofiber regeneration, revealing a critical role for α-Klotho in the regenerative cascade. Genetic silencing of Klotho in young MPCs drove mitochondrial DNA (mtDNA) damage and decreased cellular bioenergetics. Conversely, supplementation with α-Klotho restored mtDNA integrity and bioenergetics of aged MPCs to youthful levels in vitro and enhanced functional regeneration of aged muscle in vivo in a temporally-dependent manner. These studies identify a role for α-Klotho in the regulation of MPC mitochondrial function and implicate α-Klotho declines as a driver of impaired muscle regeneration with age.


Assuntos
Envelhecimento/genética , DNA Mitocondrial/genética , Mitocôndrias/genética , Músculo Esquelético/metabolismo , Mioblastos/metabolismo , Receptores de Superfície Celular/genética , Células-Tronco/metabolismo , Envelhecimento/metabolismo , Envelhecimento/patologia , Animais , Metilação de DNA , DNA Mitocondrial/metabolismo , Epigênese Genética , Regulação da Expressão Gênica no Desenvolvimento , Glucuronidase , Proteínas Klotho , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mitocôndrias/metabolismo , Músculo Esquelético/patologia , Mioblastos/patologia , Regiões Promotoras Genéticas , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Receptores de Superfície Celular/antagonistas & inibidores , Receptores de Superfície Celular/metabolismo , Regeneração/genética , Transdução de Sinais , Células-Tronco/patologia
16.
R Soc Open Sci ; 4(9): 170368, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28989744

RESUMO

Mixed-matrix membranes (MMMs) were developed by impregnating organofunctionalized nanoadditives within fouling-susceptible polysulfone matrix following the non-solvent induced phase separation (NIPS) method. The facile functionalization of nanoparticles of anatase TiO2 (nano-TiO2) by using two different organoligands, viz. Tiron and chromotropic acid, was carried out to obtain organofunctionalized nanoadditives, FT-nano-TiO2 and FC-nano-TiO2, respectively. The structural features of nanoadditives were evaluated by X-ray diffraction, X-ray photoelectron spectroscopy, Raman and Fourier transform infrared spectroscopy, which established that Tiron leads to the blending of chelating and bridging bidentate geometries for FT-nano-TiO2, whereas chromotropic acid produces bridging bidentate as well as monodentate geometries for FC-nano-TiO2. The surface chemistry of the studied membranes, polysulfone (Psf): FT-nano-TiO2 UF and Psf: FC-nano-TiO2 UF, was profoundly influenced by the benign distributions of the nanoadditives enriched with distinctly charged sites ([Formula: see text]), as evidenced by superior morphology, improved topography, enhanced surface hydrophilicity and altered electrokinetic features. The membranes exhibited enhanced solvent throughputs, viz. 3500-4000 and 3400-4300 LMD at 1 bar of transmembrane pressure, without significant compromise in their rejection attributes. The flux recovery ratios and fouling resistive behaviours of MMMs towards bovine serum albumin indicated that the nanoadditives could impart stable and appreciable antifouling activity, potentially aiding in a sustainable ultrafiltration performance.

17.
Water Sci Technol ; 75(11-12): 2598-2606, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28617279

RESUMO

Fine mesh rotating belt sieves (RBS) offer a very compact solution for removal of particles from wastewater. This paper shows examples from pilot-scale testing of primary treatment, chemically enhanced primary treatment (CEPT) and secondary solids separation of biofilm solids from moving bed biofilm reactors (MBBRs). Primary treatment using a 350 microns belt showed more than 40% removal of total suspended solids (TSS) and 30% removal of chemical oxygen demand (COD) at sieve rates as high as 160 m³/m²-h. Maximum sieve rate tested was 288 m³/m²-h and maximum particle load was 80 kg TSS/m²-h. When the filter mat on the belt increased from 10 to 55 g TSS/m², the removal efficiency for TSS increased from about 35 to 60%. CEPT is a simple and effective way of increasing the removal efficiency of RBS. Adding about 1 mg/L of cationic polymer and about 2 min of flocculation time, the removal of TSS typically increased from 40-50% without polymer to 60-70% with polymer. Using coagulation and flocculation ahead of the RBS, separation of biofilm solids was successful. Removal efficiencies of 90% TSS, 83% total P and 84% total COD were achieved with a 90 microns belt at a sieve rate of 41 m³/m²-h.


Assuntos
Reatores Biológicos , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/análise , Biofilmes , Análise da Demanda Biológica de Oxigênio , Noruega , Projetos Piloto , Eliminação de Resíduos Líquidos/instrumentação
18.
Luminescence ; 32(2): 159-170, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27323703

RESUMO

This article reports on the luminescence properties of rare earth (Dy3+ and Tm3+ )ions doped SrGa2 Si2 O8 phosphor were studied. SrGa2 Si2 O8 phosphors weresynthesizedby employing solid state reaction method.From the measured X-ray diffraction (XRD) pattern of the samplemonoclinic phase structure has been observed. Thermoluminescenceand Mechanoluminescence properties of the γ-ray irradiated samples have been studied. Photoluminescence spectra of Dy3+ activated SrGa2 Si2 O8 phosphor has been measured with an excitation wavelength at 348 nm,and it shows two emission bands at 483 and 574 nm due to 4 F9/2  â†’ 6 H15/2 and 4 F9/2  â†’ 6 H13/2 transitions respectively. Whereas the photoluminescence spectra of Tm3+ activated SrGa2 Si2 O8 phosphor has been measured with an excitation wavelength at 359 nm and it exhibits two emission bands at 454 and 472 nm due to 1 D2  â†’ 3 F4 and1 G4  â†’ 3 H6 transitions respectively. In thermoluminescence study, γ-irradiatedthermoluminescence glow curve of SrGa2 Si2 O8 :Dy3+ phosphor shows two well defined peaks at 293 °C (peak1)and 170 °C (peak2) whereas thermoluminescence glow curve of SrGa2 Si2 O8 :Tm3+ phosphor shows peaks at 292 °C (peak1) and 184 °C (peak2) indicating that two sets of traps are being activated within the particular temperature range and the trapping parameters associated with the prominent glow peaks of SrGa2 Si2 O8 :Dy3+ and SrGa2 Si2 O8 :Tm3+ are calculated using Chen's peak shape and initial rise method.From the Mechanoluminescence study, only one glow peak has been observed. Copyright © 2016 John Wiley & Sons, Ltd.


Assuntos
Disprósio/análise , Gálio/análise , Luminescência , Oxigênio/análise , Estrôncio/análise , Túlio/análise
19.
J Fluoresc ; 27(1): 251-261, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27815786

RESUMO

LaBO3:xDy3+ (x = 0.05 mol%, 0.1 mol%, 0.2 mol%, 0.5 mol%, 1 mol% and 2 mol%) phosphors were synthesized by solid-state reaction method. X-ray diffraction technique was used to confirm the formation of compound. Photoluminescence emission spectra shows two emission peaks at 470 nm and 575 nm when excitation wavelength is set at 352 nm. Photoluminescence intensity increases upto 1 mol % of Dy3+ and then starts decreasing. Dipole-dipole interaction is found to be responsible for concentration quenching of photoluminescence intensity. Commission Internationale de I'Eclairage (CIE) chromaticity diagram demonstrates that the phosphor emits in bluish white region of the visible spectrum. Critical energy transfer distance between dopant ions was determined. The mechanoluminescence characteristics were studied by the impact method. The peaks of both the mechanoluminescence (ML) intensity and the total ML intensity of the UV exposed phosphors increases with increasing impact velocity for 1 mol % concentration of Dy3+. The ML sensitivity of the LaBO3:Dy3+ (Dy3+ = 1 mol %) phosphor is comparable with the reported ML of various inorganic phosphors. The thermoluminescence characteristics of the samples were also investigated. Thermoluminescence glow peaks were recorded with 480 Gy, 80 Gy and 20 Gy dose of γ-irradiation from Co60 Source. TL trapping parameters were determined by Chen's peak shape method and glow curve deconvolution method. LaBO3:Dy3+ phosphors were found to be good mechanoluminescent materials and can be used in stress sensing application.

20.
Nanoscale ; 8(30): 14650-64, 2016 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-27439022

RESUMO

Nitrogen and fluorine co-doped graphite nanofibers (N/F-GNF) and their cumulative effect with Fe and Co have been developed as an alternative non-precious metal catalyst for efficient oxygen reduction reaction (ORR) in acidic media. The synergistic effect between the doped hetero atoms and the co-ordinated Fe and Co towards ORR activity and durability of the catalyst is deeply investigated. A high ORR onset potential comparable with commercial Pt/C catalyst is observed with the Fe-Co/NF-GNF catalyst, which indicates that this catalyst is a potential alternative to Pt/C. A fivefold increase in mass activity is achieved by the Fe-Co/NF-GNF catalyst compared to the simple N/F-GNF catalyst, which endorses the significant role of transition metal atoms in enhancing ORR activity. The advanced Fe-Co/NF-GNF catalyst also exhibits complete tolerance to CH3OH and CO. The Fe-Co/NF-GNF catalyst also exhibits excellent durability towards the ORR with only a 10 mV negative shift in its half wave potential after a 10 000 repeated potential cycling test, whereas in the case of a commercial Pt/C catalyst there was an ∼110 mV negative shift under similar environmental conditions. More stringent corrosive test cycles were also performed by maintaining the cell as high as 1.4 V with a later decrease to 0.6 V vs. RHE for 300 cycles, which showed the excellent durability of the Fe-Co/NF-GNF catalyst in comparison with the Pt/C catalyst. XPS analysis of the Fe-Co/NF-GNF catalyst presents the ORR active chemical states of N (pyridinic-N and graphitic-N) and F (semi-ionic-F) and the co-ordinated sites of Fe and Co species with the dopants. The excellent performance and durability of the Fe-Co/NF-GNF catalyst is due to the synergistic effect between the hetero atoms dopants (N and F) and strong co-ordinating bonds of M-N-C, which protect the graphene layers around the metallic species and greatly mitigates the leaching of Co and Fe during the long term cycling test. The high activity and long term durability of the Fe-Co/NF-GNF catalyst make it a promising ORR electrocatalyst for the fuel cell cathode reaction.

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