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Xu H.,Fudan University | Xiao J.,Fudan University | Liu B.,Fudan University | Griveau S.,CNRS Health Technology, Chemistry and Biology Unit | Bedioui F.,CNRS Health Technology, Chemistry and Biology Unit
Biosensors and Bioelectronics | Year: 2015

A hybrid nanocomposite based on cobalt phthalocyanine (CoPc) immobilized on nitrogen-doped graphene (N-G) (N-G/CoPc) has been developed to modify glassy carbon electrode (GCE) for the sensitive detection of thiols. The nanocomposites were characterized by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and electrochemical impedance spectroscopy (EIS). Cyclic voltammetric studies showed that cobalt phthalocyanine and nitrogen doped graphene have a synergic effect and significantly enhance the electrocatalytic activity of the modified electrode towards thiols oxidation compared with electrodes modified with solely CoPc or N-G. The electrochemical oxidation responses were studied and the reaction mechanisms were discussed. The sensors exhibited a wide linear response range from 1. μΜ to 16. mM and a low detection limit of 1. μΜ for the determination of l-cysteine, reduced l-glutathione and 2-mercaptoethanesulfonic acid in alkaline aqueous solution. The proposed N-G/CoPc hybrids contribute to the construction of rapid, convenient and low-cost electrochemical sensors for sensitive detection of thiols. © 2014 Elsevier B.V.

Maldiney T.,CNRS Health Technology, Chemistry and Biology Unit | Bessiere A.,CNRS Paris Research Institute of Chemistry | Seguin J.,CNRS Health Technology, Chemistry and Biology Unit | Teston E.,CNRS Health Technology, Chemistry and Biology Unit | And 8 more authors.
Nature Materials | Year: 2014

Optical imaging for biological applications requires more sensitive tools. Near-infrared persistent luminescence nanoparticles enable highly sensitive in vivo optical detection and complete avoidance of tissue autofluorescence. However, the actual generation of persistent luminescence nanoparticles necessitates ex vivo activation before systemic administration, which prevents long-term imaging in living animals. Here, we introduce a new generation of optical nanoprobes, based on chromium-doped zinc gallate, whose persistent luminescence can be activated in vivo through living tissues using highly penetrating low-energy red photons. Surface functionalization of this photonic probe can be adjusted to favour multiple biomedical applications such as tumour targeting. Notably, we show that cells can endocytose these nanoparticles in vitro and that, after intravenous injection, we can track labelled cells in vivo and follow their biodistribution by a simple whole animal optical detection, opening new perspectives for cell therapy research and for a variety of diagnosis applications. © 2014 Macmillan Publishers Limited. All rights reserved.

Anisur M.R.,University of Malaya | Mahfuz M.H.,University of Malaya | Kibria M.A.,University of Malaya | Saidur R.,University of Malaya | And 3 more authors.
Renewable and Sustainable Energy Reviews | Year: 2013

The application of thermal energy storage (TES) system with phase change material (PCM) is an effective way for energy conservation and greenhouse gas (GHG) emission reduction. Global warming is increasing along with the energy consumption. Many researchers are concerned about this present global environmental problem for fossil-fuel burning. Thermal energy storage system with phase change material is observed as a potential candidate for mitigating this problem. This paper emphasizes the opportunities for energy savings and greenhouse-gas emissions reduction with the implementation of PCM in TES systems. For instance, about 3.43% of CO2 emission by 2020 could be reduced through the application of PCM in building and solar thermal power systems. Similarly, energy conservation and GHGs emission reduction by other PCM applications for thermal comfort of vehicles, transport refrigeration, engine cold start, greenhouse and waste heat management are also presented. In addition, some present investigations on the performance improvement of the phase change materials are addressed. © 2012 Elsevier Ltd. All rights reserved.

Mucopolysaccharidosis type IIIA (MPS-IIIA) or Sanfilippo A syndrome is a lysosomal storage genetic disease that results from the deficiency of the N-sulfoglucosamine sulfohydrolase (SGSH) protein, a sulfamidase required for the degradation of heparan sulfate glycosaminoglycans (GAGs). The accumulation of these macromolecules leads to somatic organ pathologies, severe neurodegeneration and death. To assess a novel gene therapy approach based on prolonged secretion of the missing enzyme by the liver, mediated by hydrodynamic gene delivery, we first compared a kanamycin and an antibiotic-free expression plasmid vector, called pFAR4. Thanks to the reduced vector size, pFAR4 derivatives containing either a ubiquitous or a liver-specific promoter mediated a higher reporter gene expression level than the control plasmid. Hydrodynamic delivery of SGSH-encoding pFAR4 into MPS-IIIA diseased mice led to high serum levels of sulfamidase protein that was efficiently taken up by neighboring organs, as shown by the correction of GAG accumulation. A similar reduction in GAG content was also observed in the brain, at early stages of the disease. Thus, this study contributes to the effort towards the development of novel biosafe non-viral gene vectors for therapeutic protein expression in the liver, and represents a first step towards an alternative gene therapy approach for the MPS-IIIA disease.Gene Therapy advance online publication, 21 August 2014; doi:10.1038/gt.2014.75.

Rismanchi B.,University of Malaya | Saidur R.,University of Malaya | Saidur R.,CNRS Health Technology, Chemistry and Biology Unit | Boroumandjazi G.,University of Malaya | Ahmed S.,University of Malaya
Renewable and Sustainable Energy Reviews | Year: 2012

As the air conditioning system is one of the largest contributors to electrical peak demand, the role of the cold thermal energy storage (CTES) system has become more significant in the past decade. The present paper has reviewed the studies conducted on the energy and exergy analysis of CTES systems with a special focus on ice thermal and chilled water storage systems as the most common types of CTES. However, choosing a proper CTES technique is mainly dependent on localized parameters such as the ambient temperature profile, electricity rate structure, and user's habit, which makes it quite difficult and complicated as it depends on many individual parameters. Therefore, it was found that energy and exergy analysis can help significantly for a better judgment. The review paper has shown that the exergetic efficiency analysis can show a more realistic picture than energy efficiency analysis. In addition, the environmental impact and the economic feasibility of these systems are also investigated. It was found that, based on the total exergy efficiency, the ice on coil (internal melt) is known as the most desirable CTES system. © 2012 Elsevier Ltd.

Aman M.M.,University of Malaya | Jasmon G.B.,University of Malaya | Bakar A.H.A.,CNRS Health Technology, Chemistry and Biology Unit | Mokhlis H.,University of Malaya | Mokhlis H.,CNRS Health Technology, Chemistry and Biology Unit
Energy | Year: 2014

This paper presents a new approach for optimum simultaneous multi-DG (distributed generation) placement and sizing based on maximization of system loadability without violating the system constraints. DG penetration level, line limit and voltage magnitudes are considered as system constraints. HPSO (hybrid particle swarm optimization) algorithm is also proposed in this paper to find the optimum solution considering maximization of system loadability and the corresponding minimum power losses. The proposed method is tested on standard 16-bus, 33-bus and 69-bus radial distribution test systems. This paper will also compare the proposed method with existing Ettehadi method and present the effectiveness of the proposed method in terms of reduction in power system losses, maximization of system loadability and voltage quality improvement. © 2013 Elsevier Ltd.

Aman M.M.,University of Malaya | Jasmon G.B.,University of Malaya | Bakar A.H.A.,University of Malaya | Mokhlis H.,University of Malaya | Mokhlis H.,CNRS Health Technology, Chemistry and Biology Unit
International Journal of Electrical Power and Energy Systems | Year: 2014

This paper presents a new algorithm for network reconfiguration based on maximization of system loadability. Bifurcation theorem known as Continuation Power Flow (CPF) theorem and radial distribution load flow analysis are used to find the maximum loadability point. Network reconfiguration results are also compared with existing technique proposed in literature. In the proposed method, to find the optimum tie-switch position, a Discrete Artificial Bee Colony (DABC) approach is applied. Graph theory is used to ensure the radiality of the system. The proposed algorithm is tested on 33-bus and 69-bus radial distribution networks, each having 5-tie switches. The result shows that using the proposed method the kVA margin to maximum loading (KMML) increases, overall voltage profile also improved and the distribution system can handle more connected load (kVA) without violating the voltage and line current constraints. Results further show that the voltage limit is an important factor than the line current constraints in adding further load to the buses. © 2013 Elsevier Ltd. All rights reserved.

Aman M.M.,University of Malaya | Jasmon G.B.,University of Malaya | Bakar A.H.A.,CNRS Health Technology, Chemistry and Biology Unit | Mokhlis H.,University of Malaya | Mokhlis H.,CNRS Health Technology, Chemistry and Biology Unit
Energy Conversion and Management | Year: 2013

Distributed Generation (DG) placement on the basis of minimization of losses and maximization of system voltage stability are two different approaches, discussed in research. In the new proposed algorithm, a multi-objective approach is used to combine the both approaches together. Minimization of power losses and maximization of voltage stability due to finding weakest voltage bus as well as due to weakest link in the system are considered in the fitness function. Particle Swarm Optimization (PSO) algorithm is used in this paper to solve the multi-objective problem. This paper will also compare the propose method with existing DG placement methods. From results, the proposed method is found more advantageous than the previous work in terms of voltage profile improvement, maximization of system loadability, reduction in power system losses and maximization of bus and line voltage stability. The results are validated on 12-bus, 30-bus, 33-bus and 69-bus radial distribution networks and also discussed in detailed. © 2013 Elsevier Ltd. All rights reserved.

Raymond W.J.K.,University of Malaya | Illias H.A.,University of Malaya | Bakar A.H.A.,CNRS Health Technology, Chemistry and Biology Unit | Mokhlis H.,University of Malaya
Measurement: Journal of the International Measurement Confederation | Year: 2015

It is well known that a correlation exist between the pattern of partial discharge (PD) behavior and the insulation quality. Since different sources of partial discharge have their own unique effects on the degradation of insulation material, it is vital to investigate the relationship between the defect type and the PD to determine the insulation quality. Numerous work had been done to classify partial discharge patterns with variable success. Past research work in partial discharge classification varies greatly in terms of classification techniques used, choice of feature extraction, denoising method, training process, artificial defects created for training purposes and performance assessment. Therefore it is necessary for a literature survey to access the state of the art development in partial discharge classification. © 2015 Elsevier Ltd.All rights reserved.

The worldwide prevalence of food allergy appears to be increasing. The future of food allergy management may lie in primary prevention. It has become a public health priority in developed countries. Exclusive breast-feeding for at least 4 to 6 months and introduction of complementary foods from the age of 4-6 months are key strategies in primary food allergy prevention. Hydrolyzed formulas may be used for high risk infants who are not exclusively breastfed. Maternal elimination diets during pregnancy and lactation are currently not recommended. Little evidence supports the benefit of allergen avoidance; thus, the focus is on immunomodulatory prevention strategies. The effect of prebiotic oligosaccharides as well as probiotic bacteria, long-chain polyunsaturated fatty acids, antioxidants and vitamin D in prevention of food allergy remains unclear and requires further investigation. Increasing knowledge on the immunomodulatory effects of prenatal, perinatal, postnatal interventions and improved understanding of food allergy and associated environmental factors are likely to contribute to the development of novel strategies to prevent food allergy. It is hoped that a number of ongoing studies will help also to clarify the meaning of route of antigen exposure or maternal transmission for the promotion of tolerance. Despite the current uncertainties, prevention remains the best long-term strategy to reduce the growing burden of allergic disease. © 2015 Polish Pediatric Society. Published by Elsevier Sp. z o.o. All rights reserved.

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