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1.
Front Microbiol ; 15: 1404012, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38983632

RESUMO

Dental caries is a common human oral disease worldwide, caused by an acid-producing bacteria Streptococcus mutans. The use of synthetic drugs and antibiotics to prevent dental caries has been increasing, but this can lead to severe side effects. To solve this issue, developing and developed countries have resorted to herbal medicines as an alternative to synthetic drugs for the treatment and prevention of dental caries. Therefore, there is an urgent need for plant-derived products to treat such diseases. Bacopa monnieri, a well-documented medicinal plant, contains 52 phytocompounds, including the pentacyclic triterpenoid metabolite known as asiatic acid (ASTA). Hence, this study aimed to demonstrate, for the first time, the antibacterial activity of phytocompound ASTA against S. mutans. The findings revealed that ASTA significantly inhibited the growth of S. mutans and the production of virulence factors such as acidurity, acidogenicity, and eDNA synthesis. Molecular docking analysis evaluated the potential activity of ASTA against S. mutans virulence genes, including VicR and GtfC. Furthermore, toxicity assessment of ASTA in human buccal epithelial cells was performed, and no morphological changes were observed. An in vivo analysis using Danio rerio (zebrafish) confirmed that the ASTA treatment significantly increased the survival rates of infected fish by hindering the intestinal colonization of S. mutans. Furthermore, the disease protection potential of ASTA against the pathognomonic symptom of S. mutans infection was proven by the histopathological examination of the gills, gut, and kidney. Overall, these findings suggest that ASTA may be a promising therapeutic and alternative drug for the treatment and prevention of oral infection imposed by S. mutans.

2.
Glycobiology ; 34(4)2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38335248

RESUMO

Protein-carbohydrate interactions are involved in several cellular and biological functions. Integrating structure and function of carbohydrate-binding proteins with disease-causing mutations help to understand the molecular basis of diseases. Although databases are available for protein-carbohydrate complexes based on structure, binding affinity and function, no specific database for mutations in human carbohydrate-binding proteins is reported in the literature. We have developed a novel database, CarbDisMut, a comprehensive integrated resource for disease-causing mutations with sequence and structural features. It has 1.17 million disease-associated mutations and 38,636 neutral mutations from 7,187 human carbohydrate-binding proteins. The database is freely available at https://web.iitm.ac.in/bioinfo2/carbdismut. The web-site is implemented using HTML, PHP and JavaScript and supports recent versions of all major browsers, such as Firefox, Chrome and Opera.


Assuntos
Carboidratos , Humanos , Bases de Dados Factuais , Mutação
3.
World J Surg ; 46(11): 2806-2816, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36071288

RESUMO

INTRODUCTION: There are unique technical and management challenges associated with living donor liver transplantation (LDLT) for Budd-Chiari Syndrome (BCS). The outcomes of LDLT for BCS in comparison to other indications remain unclear and warrant elucidation. METHODS: Data of 24 BCS patients who underwent LDLT between January 2012 and June 2019 were analyzed. There were 20 adults and 4 children. The early and long-term outcomes of adult LDLT BCS patients were compared to a control group of LDLT patients for other indications and matched using propensity scoring methodology. RESULTS: Primary BCS was observed in 18 (90%) patients. Caval replacement was performed in 7 (35%) patients. Early and late hepatic venous outflow tract (HVOT) complications were seen in 1 (5%) and 3 (15%) patients. Preoperative acute kidney injury was identified as a risk factor for mortality in the BCS cohort (p = 0.013). On comparison, BCS recipients were younger with fewer comorbidities, more large volume ascites and higher rates of PVT. They also had longer cold ischemia time, increased blood loss and transfusion requirements, increased hospital stay, and higher late outflow complications. The 1-year and 3-year survivals were similar to non-BCS cohort (84.2% vs. 94% and 71.3% vs. 91.9%, respectively, log rank test p = 0.09). CONCLUSION: LDLT is a good option for symptomatic BCS who have failed non-transplant interventions. The clinical and risk factor profile of BCS recipients is distinct from non-BCS recipients. By following an algorithmic management protocol, we show on propensity-score matched analysis that outcomes of LDLT for BCS are similar to non-BCS indications.


Assuntos
Síndrome de Budd-Chiari , Transplante de Fígado , Adulto , Síndrome de Budd-Chiari/cirurgia , Criança , Humanos , Transplante de Fígado/métodos , Doadores Vivos , Pontuação de Propensão , Estudos Retrospectivos , Resultado do Tratamento , Veia Cava Inferior/cirurgia
4.
J Mol Biol ; 434(11): 167526, 2022 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-35662456

RESUMO

Protein-carbohydrate interactions play an important role in several biological processes. The mutation of amino acid residues in carbohydrate-binding proteins may alter the binding affinity, affect the functions and lead to diseases. Elucidating the factors influencing the binding affinity change (ΔΔG) of protein-carbohydrate complexes upon mutation is a challenging task. In this work, we have collected the experimental data for the binding affinity change of 318 unique mutants and related with sequence and structural features of amino acid residues at the mutant sites. We found that accessible surface area, secondary structure, mutation preference, conservation score, hydrophobicity and contact energies are important to understand the binding affinity change upon mutation. We have developed multiple regression equations for predicting the binding affinity change upon mutation and our method showed an average correlation of 0.74 and a mean absolute error of 0.70 kcal/mol between experimental and predicted ΔΔG on a 10-fold cross-validation. Further, we have validated our method using an independent test data set of 124 (62 unique) mutations, which showed a correlation and MAE of 0.79 and 0.56 kcal/mol, respectively. We have developed a web server PCA-MutPred, Protein-CArbohydrate complex Mutation affinity Predictor, for predicting the change in binding affinity of protein-carbohydrate complexes and it is freely accessible at https://web.iitm.ac.in/bioinfo2/pcamutpred. We suggest that the method could be a useful resource for designing protein-carbohydrate complexes with desired affinities.


Assuntos
Aminoácidos , Carboidratos , Mutação de Sentido Incorreto , Aminoácidos/genética , Carboidratos/química , Ligação Proteica/genética , Estrutura Secundária de Proteína , Termodinâmica
5.
J Biomol Struct Dyn ; 40(20): 10094-10105, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34219624

RESUMO

Galectin-1 (Gal-1) is the first member of galectin family, which has a carbohydrate recognition domain, specifically binds towards ß-galactoside containing oligosaccharides. Owing its association with carbohydrates, Gal-1 is involved in many biological processes such as cell signaling, adhesion and pathological pathways such as metastasis, apoptosis and increased tumour cell survival. The development of ß-galactoside based inhibitors would help to control the Gal-1 expression. In the current study, we carried out molecular dynamics (MD) simulations to examine the structural and dynamic behaviour Gal-1-thiodigalactoside (TDG), Gal-1-lactobionic acid (LBA) and Gal-1-beta-(1→6)-galactobiose (G16G) complexes. The analysis of glycosidic torsional angles revealed that ß-galactoside analogues TDG and LBA have a single binding mode (BM1) whereas G16G has two binding modes (BM1 and BM2) for interacting with Gal-1 protein. We have computed the binding free energies for the complexes Gal-1-TDG, Gal-1-LBA and Gal-1-G16G using MM/PBSA and are -6.45, -6.22 and -3.08 kcal/mol, respectively. This trend agrees well with experiments that the binding of Gal-1 with TDG is stronger than LBA. Further analysis revealed that the interactions due to direct and water-mediated hydrogen bonds play a significant role to the structural stability of the complexes. The result obtained from this study is useful to formulate a set of rules and derive pharmacophore-based features for designing inhibitors against galectin-1.Communicated by Ramaswamy H. Sarma.


Assuntos
Galectina 1 , Simulação de Dinâmica Molecular , Humanos , Galectina 1/química , Galectina 1/metabolismo , Galactosídeos , Carboidratos
6.
Brief Bioinform ; 22(4)2021 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-33313775

RESUMO

Protein-carbohydrate interactions play a major role in several cellular and biological processes. Elucidating the factors influencing the binding affinity of protein-carbohydrate complexes and predicting their free energy of binding provide deep insights for understanding the recognition mechanism. In this work, we have collected the experimental binding affinity data for a set of 389 protein-carbohydrate complexes and derived several structure-based features such as contact potentials, interaction energy, number of binding residues and contacts between different types of atoms. Our analysis on the relationship between binding affinity and structural features revealed that the important factors depend on the type of the complex based on number of carbohydrate and protein chains. Specifically, binding site residues, accessible surface area, interactions between various atoms and energy contributions are important to understand the binding affinity. Further, we have developed multiple regression equations for predicting the binding affinity of protein-carbohydrate complexes belonging to six categories of protein-carbohydrate complexes. Our method showed an average correlation and mean absolute error of 0.731 and 1.149 kcal/mol, respectively, between experimental and predicted binding affinities on a jackknife test. We have developed a web server PCA-Pred, Protein-Carbohydrate Affinity Predictor, for predicting the binding affinity of protein-carbohydrate complexes. The web server is freely accessible at https://web.iitm.ac.in/bioinfo2/pcapred/. The web server is implemented using HTML and Python and supports recent versions of major browsers such as Chrome, Firefox, IE10 and Opera.


Assuntos
Carboidratos/química , Modelos Moleculares , Linguagens de Programação , Proteínas/química , Ligação Proteica , Elementos Estruturais de Proteínas
7.
BJS Open ; 4(4): 630-636, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32379933

RESUMO

BACKGROUND: Outcomes of high-risk hepatoblastoma have been dismal, especially in resource-challenged countries where access to chemotherapy and paediatric liver transplantation is limited for the underprivileged. This study aimed to assess the results of treatment of high-risk hepatoblastoma in a tertiary centre, including patients who had non-transplant surgical procedures in the form of extended resection. METHODS: A review of patients with high-risk hepatoblastoma treated between January 2012 and May 2018 was carried out. Perioperative data and long-term outcomes were analysed. RESULTS: Of 52 children with hepatoblastoma, 22 were considered to have high-risk hepatoblastoma (8 girls and 14 boys). The mean(s.d.) age at diagnosis was 35(20) months. Of these 22 children, five died without surgery. Of the remaining 17 who underwent surgery, six had a resection (4 right and 2 left trisectionectomies) and 11 underwent living-donor liver transplantation. Median follow-up was 48 (range 12-90) months. Thirteen of the 17 children were alive at last follow-up and four developed disseminated disease (3 had undergone liver transplantation and 1 liver resection). The overall survival rate at 1, 3 and 5 years was 77, 64 and 62 per cent for the whole cohort with high-risk hepatoblastoma. In children who had surgery, 1-, 3- and 5-year survival rates were 91, 82 and 73 per cent for transplantation and 100, 83 and 83 per cent for resection. There was no difference in survival between the two surgical groups. CONCLUSION: Excellent results in the treatment of high-risk hepatoblastoma are possible, even in resource-challenged countries.


ANTECEDENTES: Los resultados del hepatoblastoma de alto riesgo (high risk hepatoblastoma, HRH) han sido pésimos, especialmente en países con recursos limitados, donde el acceso a la quimioterapia y al trasplante hepático pediátrico es limitado para los menos privilegiados. Este estudio tuvo como objetivo evaluar los resultados del HRH en un centro de tercer nivel, incluyendo a los pacientes que se sometieron a procedimientos quirúrgicos diferentes del trasplante en forma de resecciones extendidas. MÉTODOS: Se realizó una revisión de los pacientes con HRH tratados entre enero del 2012 y mayo de 2018. Se analizaron los datos perioperatorios y los resultados a largo plazo. RESULTADOS: De 52 niños con hepatoblastomas, 22 fueron considerados HRH (8 pacientes del sexo femenino/14 del sexo masculino). La edad media al diagnóstico fue de 35 ± 20 meses. De estos 22 pacientes, cinco fallecieron sin haber sido intervenidos quirúrgicamente. De los 17 restantes que se sometieron a cirugía, en seis se realizaron resecciones (4 trisectorectomías derechas, 2 trisectorectomías izquierdas) y 11 se sometieron a un trasplante de hígado de donante vivo. La mediana de seguimiento fue de 48 meses (12-90 meses). Trece de 17 niños estaban vivos en el último seguimiento, y cuatro habían desarrollado enfermedad diseminada (3 habían sido sometidos a trasplante hepático y 1 a resección hepática). La supervivencia global a 1, 3 y 5 años fue del 77,3%, 63,6% y 62% para toda la cohorte de HRH. Entre los que se sometieron a cirugía, las supervivencias a 1, 3 y 5 años fueron del 90,9%, 81,8% y 72,7% para el trasplante y del 100%, 83,3% y 83,3% para la resección. No hubo diferencia en la supervivencia entre los dos grupos sometidos a cirugía. CONCLUSIÓN: En países con recursos limitados es posible obtener excelentes resultados en el tratamiento de HRH.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Hepatectomia , Hepatoblastoma/terapia , Neoplasias Hepáticas/terapia , Transplante de Fígado , Quimioterapia Adjuvante , Pré-Escolar , Terapia Combinada , Feminino , Hepatoblastoma/mortalidade , Humanos , Índia , Lactente , Neoplasias Hepáticas/mortalidade , Doadores Vivos , Masculino , Estadiamento de Neoplasias , Prognóstico , Estudos Prospectivos , Taxa de Sobrevida
8.
Bioinformatics ; 36(11): 3615-3617, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32119071

RESUMO

MOTIVATION: Protein-carbohydrate interactions perform several cellular and biological functions and their structure and function are mainly dictated by their binding affinity. Although plenty of experimental data on binding affinity are available, there is no reliable and comprehensive database in the literature. RESULTS: We have developed a database on binding affinity of protein-carbohydrate complexes, ProCaff, which contains 3122 entries on dissociation constant (Kd), Gibbs free energy change (ΔG), experimental conditions, sequence, structure and literature information. Additional features include the options to search, display, visualization, download and upload the data. AVAILABILITY AND IMPLEMENTATION: The database is freely available at http://web.iitm.ac.in/bioinfo2/procaff/. The website is implemented using HTML and PHP and supports recent versions of major browsers such as Chrome, Firefox, IE10 and Opera. CONTACT: gromiha@iitm.ac.in. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Assuntos
Carboidratos , Software , Bases de Dados de Proteínas
9.
Transplant Proc ; 51(3): 1002-1005, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30979439

RESUMO

Increased biliary complications in hepatopulmonary syndrome (HPS) have been hypothesized due to post-transplant hypoxemia. Supporting this hypothesis, we report histopathological findings from an explant liver allograft where the recipient suffered severe and prolonged post-operative hypoxemia. A 4-year-old child underwent liver transplantation (LT) for decompensated chronic liver disease complicated by severe HPS. The post-operative period was complicated by severe prolonged hypoxemia. HPS resolved completely 6 months after LT only to recur 3 months later due to graft dysfunction. The child underwent retransplantation 8 months after the first LT. The explant liver showed bile duct loss along with ulceration and fibrosis of large hilar bile ducts biliary, suggestive of ischemic cholangiopathy. Based on the histopathology findings, we suggest that severe prolonged hypoxemia during post-transplant period could cause ischemic cholangiopathy, which can lead to biliary complications.


Assuntos
Doenças dos Ductos Biliares/etiologia , Ductos Biliares/irrigação sanguínea , Síndrome Hepatopulmonar/cirurgia , Hipóxia/complicações , Transplante de Fígado/efeitos adversos , Complicações Pós-Operatórias , Aloenxertos , Doenças dos Ductos Biliares/diagnóstico , Pré-Escolar , Colangiografia , Síndrome Hepatopulmonar/diagnóstico , Humanos , Masculino
10.
Indian J Pharmacol ; 51(1): 31-39, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31031465

RESUMO

CONTEXT: Homology modeling plays role in determining the therapeutic targets dreadful for condition such as neurodegenerative diseases (NDD), which pose challenge in achieving the effective managements. The structures of the serotonin transporter (SERT), aquaporin (AQP), and tropomyosin receptor kinase (TrkA) which are implicated in NDD pathology are still unknown for Lumbricus terrestris, but the three-dimensional (3D) structure of the human counterpart for modeling. AIM: This study aims to generate and evaluate the 3D structure of TrkA, SERT, and AQP proteins and their interaction with the ligands, namely Asiaticoside-D (AD) and levodopa (L-DOPA) the anti-NDD agents. SUBJECTS AND METHODS: Homology modeling for SERT, AQP, and TrkA proteins of Lumbricus terrestris using SWISS-MODEL Server and the modeled structure was validated using Rampage Server. Wet-lab analysis of their correspondent m-RNA levels was also done to validate the in silico data. RESULTS: It was found that TrkA had moderately high homology (67%) to human while SERT and AQP could exhibit 58% and 42%, respectively. The reliability of the model was assessed by Ramachandran plot analysis. Interactions of AD with the SERT, AQP-4, and TrkA showed the binding energies as -9.93, 8.88, and -7.58 of Kcal/mol, respectively, while for L-DOPA did show -3.93, -5.13, and -6.0 Kcal/mol, respectively. The levels of SERT, TrkA, and AQP-4 were significantly reduced (P < 0.001) on ROT induced when compared to those of control worms. On ROT + AD supplementation group (III), m-RNA levels were significantly increased (P < 0.05) when compared to those of ROT induced worms (group II). CONCLUSION: Our pioneering docking data propose the possible of target which is proved useful for therapeutic investigations against the unconquered better of NDD.


Assuntos
Aquaporinas/metabolismo , Levodopa/farmacologia , Modelos Moleculares , Fármacos Neuroprotetores/farmacologia , Receptor trkA/metabolismo , Proteínas da Membrana Plasmática de Transporte de Serotonina/metabolismo , Triterpenos/farmacologia , Animais , Aquaporinas/genética , Gânglios dos Invertebrados/efeitos dos fármacos , Gânglios dos Invertebrados/lesões , Gânglios dos Invertebrados/metabolismo , Oligoquetos , Receptor trkA/genética , Proteínas da Membrana Plasmática de Transporte de Serotonina/genética
11.
J Biomol Struct Dyn ; 37(18): 4813-4824, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-30686127

RESUMO

Abbreviations HA Hemagglutinin MD Molecular Dynamics MM-PBSA Molecular Mechanics Poisson-Boltzmann Surface Area NA Neuraminidase NAMD Nanoscale Molecular Dynamic Simulation PMEMD Particle Mesh Ewald Molecular Dynamics RMSD Root-Mean-Square Deviation RMSF Root-Mean-Square Fluctuation SIA sialic acid VMD Visual Molecular Dynamics Communicated by Ramaswamy H. Sarma.


Assuntos
Glicoproteínas de Hemaglutininação de Vírus da Influenza/química , Virus da Influenza A Subtipo H5N1/química , Ácido N-Acetilneuramínico/química , Sítios de Ligação , Ligação de Hidrogênio , Ligantes , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Ácido N-Acetilneuramínico/análogos & derivados
12.
Protein Pept Lett ; 25(4): 379-389, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29473490

RESUMO

BACKGROUND: Protein-carbohydrate interactions play vital roles in several biological processes in living organisms. The comparative analysis of binding site residues along with stabilizing residues in protein-carbohydrate complexes provides ample insights to understand the structure, function and recognition mechanism. OBJECTIVE: The main objective of this study is to identify and analyze the residues, which are involved in both folding and binding of the protein-carbohydrate complexes. METHODS: We have identified the stabilizing residues using the knowledge of hydrophobicity, longrange interactions and conservation, as well as binding site residues using a distance cutoff of 3.5Å between any heavy atoms in protein and ligand. Residues, which are common in stabilizing and binding, are termed as key residues. These key resides are analyzed with various sequence and structure based parameters such as frequency of occurrence, surrounding hydrophobicity, longrange order and conservation score. RESULTS: In this work, we have identified 2.45% binding site residues in a non-redundant dataset of 1130 complexes using distance-based criteria and 7.07% stabilizing residues using the concepts of hydrophobicity, long-range interactions and conservation of residues. Further, 5.9% of binding and 2.04% of stabilizing residues are common to each other, which are termed as key residues. The key residues have been analysed based on protein classes, carbohydrate types, gene ontology functional classifications, amino acid preference and structure-based parameters. We found that all-ß, α+ß and α/ß have more key residues than other protein classes and most of the KRs are present in ß-strands, which shows their importance in stability and binding of complexes. On the ligand side, Lsaccharide has the highest number of key residues and it has a high percentage of KRs in SRs and BRs than other carbohydrate types. Further, polar and charged residues have a high tendency to serve as key residues. Classifications based on gene ontology terms revealed that Lys is preferred in all the three groups: molecular functions, biological processes and cellular components. Key residues have 6 to 9 contacts within the protein and make only one contact with the carbohydrate ligand. These contacts are dominant to form polar-nonpolar contacts followed by the contacts between charged atoms. Further, the influence of sequence and structural parameters such as surrounding hydrophobicity, solvent accessibility, secondary structure, long-range order and conservation score has been discussed. CONCLUSION: The results obtained in the present work provide deep insights for understanding the interplay between stability and binding in protein-carbohydrate complexes.


Assuntos
Carboidratos/química , Modelos Moleculares , Proteínas/química , Sítios de Ligação , Interações Hidrofóbicas e Hidrofílicas , Ligantes , Ligação Proteica , Dobramento de Proteína , Estrutura Secundária de Proteína , Solventes/química , Termodinâmica
13.
Waste Manag ; 64: 286-304, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28336335

RESUMO

This work studies the reuse of spent shea waste as an economic construction material in improving fired clay bricks manufacture aside providing a novel approach to ecofriendly managing its excessive generated from the shea agroindustry. For this purpose, the influence of spent shea waste addition on the chemical, mineralogical, molecular bonding and technological properties (i.e. compressive strength and water absorption) of the fired clay bricks were extensively investigated. The results indicated that the chemical, mineralogical, phase transformations, molecular bonding and thermal behavior of the produced bricks were practically unaffected by the addition of spent shea waste. However, spent shea waste addition increased the compressive strengths and water absorptions of the brick products. Potential performance benefits of reusing spent shea waste was improved fluxing agents, energy-contribution reaction, excellent porosifying effect, reduced thermal conductivity and enhanced compressive strengths of the brick products. This research has therefore provided compelling evidence that could create newfound route for the synergistic ecofriendly reuse of spent shea waste to enhance clay brick construction aside being a potential mainstream disposal option.


Assuntos
Silicatos de Alumínio , Materiais de Construção , Reciclagem , Argila , Força Compressiva , Eliminação de Resíduos , Condutividade Térmica
14.
J Environ Manage ; 191: 66-74, 2017 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-28088059

RESUMO

The peculiar challenge of effective disposing abundant spent shea waste and the excellent compositional variation tolerance of clay material offered an impetus to examine the incorporation of spent shea waste into clay material as an eco-friendly disposal route in making clay bricks. For this purpose, the chemical constituent, mineralogical compositions and thermal behavior of both clay material and spent shea waste were initially characterized from which modelled brick specimens incorporating 5-20 wt% of the waste into the clay material were prepared. The clay material showed high proportions of SiO2 (52.97 wt%) and Al2O3 (27.10 wt%) indicating their rich kaolinitic content: whereas, the inert nature of spent shea waste was exhibited by their low oxide content. The striking similarities in infrared absorption bands of pristine clay material and clay materials incorporated with 15 wt% of spent shea waste showed that the waste incorporation had no impact on bond formation of the clay bricks. Potential performance benefits of developing bricks from clay material incorporated with spent shea waste included improved fluxing agents, economic sintering and making of sustainable bricks. Consequently, the analytical results authenticate the incorporation of spent shea waste into clay materials for various desired benefits aside being an environmental correct route of its disposal.


Assuntos
Materiais de Construção , Dióxido de Silício , Silicatos de Alumínio/química , Emolientes , Indústrias
15.
Artigo em Inglês | MEDLINE | ID: mdl-28038372

RESUMO

In the present work, we demonstrate the photocatalytic properties of nanosized TiO2, and different levels of ZnS-loaded TiO2/ZnS composites, for the degradation of the organic dyes brilliant green (BG), and methylene blue (MB) under solar light irradiation. For this process, TiO2 and the composites were synthesized by a sol-gel method. Further, the prepared products were subjected to structural, optical, and morphological characterizations. The results of the photocatalytic activity imply that for the samples studied, TiO2 loaded with an optimum level of zinc (0.25M), and sulfur (0.5M) is better able to actively degrade both BG and MB, due to its enhanced BET surface area, reduced band gap, and low charge transfer resistance.

16.
Plant Cell Rep ; 35(5): 1189-203, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26956134

RESUMO

KEY MESSAGE: Coexpression of two antifungal genes ( NPR1 and defensin ) in transgenic peanut results in the development of resistance to two major fungal pathogens, Aspergillus flavus and Cercospora arachidicola. Fungal diseases have been one of the principal causes of crop losses with no exception to peanut (Arachis hypogeae L.), a major oilseed crop in Asia and Africa. To address this problem, breeding for fungal disease resistance has been successful to some extent against specific pathogens. However, combating more than one fungal pathogen via breeding is a major limitation in peanut. In the present study, we demonstrated the potential use of co-overexpression of two genes, NPR1 and defensin isolated from Brassica juncea and Trigonella foenum-graecum respectively; that offered resistance towards Aspergillus flavus in peanut. The transgenic plants not only resisted the mycelial growth but also did not accumulate aflatoxin in the seeds. Resistance was also demonstrated against another pathogen, Cercospora arachidicola at varied levels; the transgenic plants showed both reduction in the number of spots and delay in the onset of disease. PCR, Southern and Western blot analysis confirmed stable integration and expression of the transgenes in the transgenic plants. The combinatorial use of the two pathogen resistance genes presents a novel approach to mitigate two important fungal pathogens of peanut.


Assuntos
Arachis/imunologia , Resistência à Doença/genética , Mostardeira/genética , Doenças das Plantas/imunologia , Proteínas de Plantas/metabolismo , Trigonella/genética , Arachis/genética , Arachis/microbiologia , Ascomicetos/fisiologia , Aspergillus flavus/fisiologia , Defensinas/genética , Defensinas/metabolismo , Expressão Gênica , Doenças das Plantas/microbiologia , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas , Plântula/genética , Plântula/imunologia , Plântula/microbiologia , Sementes/genética , Sementes/imunologia , Sementes/microbiologia , Transformação Genética , Transgenes
17.
Spectrochim Acta A Mol Biomol Spectrosc ; 149: 468-75, 2015 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-25978014

RESUMO

In this paper, the effect of sugarcane bagasse ash (SCBA) addition to the brick making clay has been analyzed using spectroscopic techniques. For that, mixtures of brick making clay (BMC) with sugarcane bagasse ash (SCBA) in proportions of 0-20 wt.% were hydraulic uniaxially pressed and sintered at temperatures of 800-1100 °C. The partial replacement of the brick making clay with SCBA was studied with chemical and mineralogical analyzes (XRF and X-ray diffraction). The quantitative estimation of minerals was made by FTIR analysis. The results of FT-IR reveal that kaolinite, quartz, and lignin are predominant, whereas, cellulose and calcite are in moderate levels. In addition, magnetite and hematite are found in trace level. The overall results reveal that the brick making clay substituted with 15 wt.% of SCBA can open up a new path for the fabrication of quality bricks at low cost.

18.
Spectrochim Acta A Mol Biomol Spectrosc ; 143: 179-86, 2015 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-25727294

RESUMO

We present the synthesis and characterization of nanocrystalline ZnO doped with Pb in different concentrations. The structural and chemical compositions of the products are characterized by XRD, XPS, EDS and FT-IR spectroscopy. The observed results suggest that Pb ions (Pb(2+) and Pb(4+)) are successfully incorporated into the lattice position of Zn(2+) ions in ZnO. The optical properties of the products are studied by UV-Vis and room temperature PL measurements. The PL emission spectra of ZnO:Pb, show the intensity quenching for both the UV and visible emissions. The influence of Pb on controlling the size and morphology of ZnO is studied by FESEM and confirmed by HRTEM. Amperometric response shows that ZnO incorporated with 0.075M of Pb ions has enhanced sensor activity for H2O2 than the undoped product.


Assuntos
Chumbo/química , Óxido de Zinco/química , Cátions , Cristalização , Peróxido de Hidrogênio/química , Nanopartículas Metálicas
19.
Artigo em Inglês | MEDLINE | ID: mdl-25756552

RESUMO

Zinc oxide have been produced via a simple green method from zinc nitrate and leaf extract aqueous solutions. Prepared ZnO nanoparticles (NPs) were investigated by employing through UV-Visible diffuse reflectance spectroscopy (UV-DRS), photoluminescence (PL) spectroscopy, X-ray diffraction (XRD), Fourier transform infrared (FTIR), field emission-scanning electron microscope (FE-SEM), and transmission electron microscope (TEM), respectively. The present investigation, confirmed the estimated band gap 3.51eV and the PL intensity at 402nm in visible region are dependent upon the geometrical shape and size of the ZnO NPs. The TEM micrograph and XRD pattern confirmed the hexagonal wurtzite structure of ZnO NPs. The presence of functional groups and the chemical bonding are confirmed by FTIR spectra. EDS shows that the highly pure ZnO nanostructures. Moreover, the catalytic activity of synthesized ZnO in the reduction of methylene blue was studied by UV-Vis spectroscopy. The effects of process conditions on the morphology and size of ZnO have been found from FE-SEM and TEM analyses, respectively.


Assuntos
Óxido de Zinco/química , Catálise , Química Verde , Nanopartículas Metálicas , Azul de Metileno/química , Azul de Metileno/efeitos da radiação , Oxirredução , Fotólise , Phyllanthus , Extratos Vegetais/química , Extratos Vegetais/efeitos da radiação , Óxido de Zinco/síntese química , Óxido de Zinco/efeitos da radiação
20.
Pediatr Surg Int ; 30(10): 1045-9, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25064227

RESUMO

PURPOSE: Children with cholestatic disorders have undergone liver transplantation for intractable pruritus unresponsive to medical therapy even in the absence of liver failure. Biliary diversion procedures interrupt the entero-hepatic circulation of bile acids allowing them to be excreted in the feces thereby lowering the total bile acid pool. We evaluated the outcome of partial internal biliary diversion (PIBD) in children with intractable pruritus from inherited cholestatic disorders. METHODS: The records of children who underwent PIBD over a 4-year period were reviewed for etiology of liver disease, demographic data, preoperative and postoperative biochemical profile and improvement of pruritus. Standard statistical methods were used for analysis. RESULTS: Of the 12 children, 10 had progressive familial intrahepatic cholestasis (PFIC) and 2 had Alagille syndrome (AS). PIBD was done using an isolated jejunal loop as a conduit from gall bladder to mid ascending colon. Median period of follow up was 30 months. Pruritus resolved in nine children with significant reduction of serum bile acids (P < 0.02). CONCLUSION: To our knowledge, this is the largest reported series of children with PIBD. PIBD is a safe, well-tolerated and effective alternative to liver transplant in children with PFIC and AS who have intractable pruritus in the absence of synthetic liver failure.


Assuntos
Ductos Biliares/cirurgia , Procedimentos Cirúrgicos do Sistema Biliar/métodos , Colestase/complicações , Colestase/cirurgia , Prurido/etiologia , Prurido/cirurgia , Criança , Pré-Escolar , Feminino , Seguimentos , Humanos , Lactente , Masculino , Resultado do Tratamento
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