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Mater Today Bio ; 8: 100072, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32939450


Green fabrication of nanoscale materials is highly desirable because of associated adverse effects with conventional nanomaterial biomedical applications. Moreover, the higher selective nature of the blood-brain barrier (BBB) limits the brain ailments treatment through conventional chemotherapy, thus providing room for nanotechnology-based modalities for BBB traversing. In this contribution, we have biosynthesized gold nanoparticles from the HAuCl4 solution in the aged cells culture medium. This approach is highly facile without any other chemical utilization. The cell culture medium age and cell number can tune the Au nanoparticles (AuNPs) size from 2 to several hundred nm. The 24 h MTT assay and cell uptake studies in vitro and murine models' vital organs (liver, kidney, spleen, lung, and heart) study up to 48 h demonstrated that biosynthesized AuNPs were biocompatible and BBB amenable. Interestingly, the transferrin and cell culture medium isolated proteins were found factors responsible for HAuCl4 solution biomineralization and size control. Moreover, the protein corona on biosynthesized AuNPs could help them traverse BBB both in vitro and in vivo, suggesting their potential applications for brain disease theranostics. In conclusion, the biosynthesis of AuNPs from aged cells medium is highly facile, green, and biocompatible for brain disease theranostics.

Chemosphere ; 80(4): 422-7, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20529695


The photolytic degradation of the diazo dye, Amido Black, using UV/H(2)O(2) has been carried out experimentally and parameters for most efficient dye degradation have been determined. The degradation of the dye was followed by UV-Vis spectroscopy, HPLC, and LC-MS and is proposed to be initiated by ()OH radicals formed by the photolysis of H(2)O(2). A detailed study was also carried out using LC-MS and LC-MS/MS to determine the degradation pathway of the dye as well as to identify some of the intermediate products formed. Our results suggest that Amido Black degradation occurs preferentially by ()OH radical attack at the more electron rich diazo functionality of the molecule. Furthermore, evidence is presented that subsequent steps in this diazo dye degradation pathway include radical denitration, radical desulfonation and radical diazotization. This report is one of the very few studies that have proposed possible mechanistic pathways for the degradation pathways of a diazo compound.

Negro de Amido/química , Cromatografia Líquida de Alta Pressão , Corantes/química , Espectrometria de Massas em Tandem , Peróxido de Hidrogênio/química , Oxirredução , Fotólise , Espectrofotometria Ultravioleta , Raios Ultravioleta
J Hazard Mater ; 166(1): 6-16, 2009 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-19128875


Synthetic dyes are a major part of our life. Products ranging from clothes to leather accessories to furniture all depend on extensive use of organic dyes. An unfortunate side effect of extensive use of these chemicals is that huge amounts of these potentially carcinogenic compounds enter our water supplies. Various advanced oxidation processes (AOPs) including the use of high-energy radiation have been developed to degrade these compounds. In this review, dye decoloration and degradation as a result of its exposure to high energy radiation such as gamma radiation and pulsed electron beam are discussed in detail. The role of various transient species such as H, OH and e(aq)(-) are taken into account as reported by various researchers. Literature citations in this area show that e(aq)(-) is very effective in decolorization but is less active in the further degradation of the products formed. The degradation of the dyes is initiated exclusively by OH attack on electron-rich sites of the dye molecules. Additionally, various parameters that affect the efficiency of radiation induced degradation of dyes, such as effect of radiation dose, oxygen, pH, hydrogen peroxide, added ions and dye classes are also reviewed and summarized. Lastly, pilot plant application of radiation for wastewater treatment is briefly discussed.

Corantes/efeitos da radiação , Fotólise , Purificação da Água/métodos , Corantes/química , Radical Hidroxila/química , Resíduos Industriais/prevenção & controle , Poluentes Químicos da Água/efeitos da radiação
Artigo em Inglês | MEDLINE | ID: mdl-18986828


The absorption and fluorescence spectra of Rose Bengal dye were studied in various solvents. It was found that solvent effects on the absorption wavelength are consistent with the solvatochromic model of Kamlet, Abboud and Taft. The solvent polarizability value pi* was found to have a linear relationship with the absorption wavelength of the dye in various solvents. Additionally, the normalized transition energy value (E(T)(N)) showed some scattering when plotted versus Deltanu(af). Density functional calculations were used to assign the absorption in the region 540-570 nm to a pi-pi* transition between the HOMO and LUMO of the anion. Experimental ground state and excited state dipole moments were calculated by using the solvatochromatic shifts of absorption and fluorescence spectra as a function of the dielectric constant (epsilon) and refractive index (n). The dipole moment for Rose Bengal was found to be 1.72 Debye in the ground state, whereas this value was 2.33 Debye in the excited state.

Rosa Bengala/química , Solventes/química , Absorção , Solubilidade , Espectrometria de Fluorescência
J Hazard Mater ; 159(2-3): 602-9, 2008 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-18395977


Rose Bengal (C.I. name is Acid Red 94) was irradiated with UV light in the presence of hydrogen peroxide. The photoinduced decolorization of the dye was monitored spectrophotometrically. The apparent rate of decolorization was calculated from the observed absorption data and was found to be pseudo first order. A systematic study of the effect of dye concentration and H(2)O(2) concentration on the kinetics of dye decolorization was also carried out. Dye decolorization increased with increasing H(2)O(2) concentration and decreasing dye concentration. The maximum dye decolorization was determined as 90% with 0.005 mM dye at optimum 0.042 M H(2)O(2) and pH 6.6. Additionally, the effect on decolorization of this dye in the presence of some additives (ions) was also investigated. It was seen that sulphite caused a maximum effect on % decolorization of the dye solution. A plausible explanation involving the probable radical initiated mechanism was given to explain the dye decolorization. The experimental data was also optimized using the response surface methodology (RSM). According to ANOVA results, the proposed model can be used to navigate the design space. It was found that the response of Rose Bengal degradation is very sensitive to the independent factors of dye concentration, H(2)O(2) concentration, pH and reaction time. The proposed model for D-optimal design fitted very well with the experimental data with R(2) and R(adj)(2) correlation coefficients of 0.85 and 0.80, respectively.

Corantes Fluorescentes/química , Corantes Fluorescentes/efeitos da radiação , Peróxido de Hidrogênio/química , Rosa Bengala/química , Rosa Bengala/efeitos da radiação , Algoritmos , Concentração de Íons de Hidrogênio , Indicadores e Reagentes , Cinética , Modelos Estatísticos , Raios Ultravioleta
Middle East J Anaesthesiol ; 18(3): 651-64, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16381271


OBJECTIVE: To look at minor complications attributable to anesthesia in adult surgical patients at our Institution and to identify various contributing factors. DESIGN: Descriptive cross sectional audit. SETTING: Aga Khan University Hospital, Karachi, Pakistan. STUDY PARTICIPANTS: Seven hundred and thirty surgical patients undergoing elective surgery were recruited. INTERVENTIONS: This was a non-interventional study and data was collected prospectively based on predefined criteria. MAIN OUTCOME MEASURES: The incidence of nausea, vomiting, sore throat, headache, drowsiness, phlebitis, dizziness, myalgia, transient nerve palsy, conjunctivitis, ringing of ears, low backache, lip injury, dental injury or any other minor complications were looked at. RESULTS: Nausea, sore throat and vomiting were the highest reported complications. The incidence of nausea, drowsiness and dizziness was less in patients more than sixty years of age. Incidence of nausea and vomiting was higher in ASA 1 patients and in surgery lasting less than ninety minutes. Headache and dizziness were reported high in certain surgical specialties. CONCLUSION: The overall rate of minor complications following anesthesia was 12.6%. No complications were reported by 30% of the study population. The data has given us a benchmark for patient information and will be used for risk reduction in our Department of Anaesthesiology.

Anestesia por Condução/efeitos adversos , Anestesia Geral/efeitos adversos , Complicações Pós-Operatórias , Adulto , Humanos , Pessoa de Meia-Idade
J Pak Med Assoc ; 51(3): 105-9, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11381821


OBJECTIVE: To determine the anatomical variations of the internal jugular vein (IJV) in Pakistani adult population with the help of Site Rite II ultrasound machine. MATERIAL AND METHOD: The right IJV relation to the carotid artery was visualized at four different landmarks (angle of the mandible, thyroid cartilage, cricoid cartilage, and the supraclavicular area). Size of IJV in comparison to carotid artery was also seen. RESULTS: In 49 cases the IJV was found in aberrant relation to carotid artery at the angle of the mandible (p value < 0.05), 22 at the thyroid cartilage, 20 at the cricoid cartilage, and 46 at the supraclavicular area (p value < 0.05). In 93% of cases the IJV was found to be larger than the carotid artery. CONCLUSION: Care should be taken while cannulating IJV at the angle of the mandible and supra clavicular area by external landmark guided technique. Ultrasound guided technique should be used in every anticipated difficult case.

Veias Jugulares/anatomia & histologia , Veias Jugulares/diagnóstico por imagem , Adolescente , Adulto , Idoso , Distribuição de Qui-Quadrado , Estudos Transversais , Feminino , Humanos , Veias Jugulares/anormalidades , Masculino , Pessoa de Meia-Idade , Paquistão , Probabilidade , Amostragem , Sensibilidade e Especificidade , Ultrassonografia
JAMA ; 218(3): 447-8, 1971 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-5109875

Coito , Islamismo