Hepatitis B vaccination coverage among Iranian children aged 15-26 months in 2006

This study in 2006 estimated the hepatitis B virus (HBV) vaccination coverage in the Islamic Republic of Iran at the national and district levels in urban, rural and remote populations of 41 university health service areas. Of 21 905 children recruited to the study, vaccination coverage based on vaccination card records was 100% in 14, 15 and 10 of the 41 university areas for the 1st, 2nd and 3rd doses of HBV respectively. National levels of HBV1, HBV2 and HBV3 coverage were 98.9%, 98.8% and 98.4% respectively. The lowest HBV vaccination coverage rate was 90.7% (in a remote district). HBV vaccination coverage was at an acceptable level in Iranian children

A population-based algorithm for the railroad blocking problem

Railroad blocking problem (RBP) is one of the problems that need an important decision in freight railroads. The objective of solving this problem is to minimize the costs of delivering all commodities by deciding which inter-terminal blocks to build and by specifying the assignment of commodities to these blocks, while observing limits on the number and cumulative volume of the blocks assembled at each terminal. RBP is an NP-hard combinatorial optimization problem with billions of decision variables. To solve the real-life RBP, developing a metaheuristic algorithm is necessary. In this paper, for the first time, a new genetic algorithm-based solution method, which is a population-based algorithm, is proposed to solve the RBP. To evaluate the efficiency and the quality of solutions of the proposed algorithm, several simulated test problems are used. The quality and computational time of the generated solutions for the test problems with the proposed genetic algorithm are compared with the solutions of the CPLEX software. The results show high efficiency and effectiveness of the proposed algorithm

Toothpastes: A review of types, ingredients and possible side effects

Introduction: Toothpastes are one of the most widely sold and used dental products, with their use as one of the most popular oral hygiene behaviors in developed countries. A large variety of toothpastes are available on the market for different purpose, making it difficult for patients to select appropriate ones and for clinicians to prescribe the most useful one. This review provides details on the ingredients of toothpastes and their clinical use, trying to assist oral care practitioners in recommending appropriate toothpastes to their patients based on their individual needs. Review Report: This review was carried out by running a search in various databases, including references books, PubMed, ISI Web of Science and Google search engine from 1973 to 2011 using the terms toothpastes, Periodontics and dental plaque. Results: There are large varieties of toothpastes for different purposes: caries prevention, gingivitis prevention, anti-calculus, dentin hypersensitivity prevention and for tooth whitening, with a wide range of active and non-active ingredients, including abrasives, humectants, preservatives, thickening or binding agents, detergents, flavoring agents and therapeutic agents as fluoride, bacteriostatics, pyrophosphates, tooth desensitizing agents etc. Some studies have evaluated the effects, advantages and disadvantages of each ingredient. Conclusion: It is absolutely necessary for dental practitioners to have a sound knowledge of chemical compositions and ingredients of toothpastes to be able to assist their patients in selecting appropriate and efficacious toothpastes

Photodynamic therapy in 3D cancer models and the utilisation of nanodelivery systems

Photodynamic therapy (PDT) is the subject of considerable research in experimental cancer models mainly for the treatment of solid cancerous tumours. Recent studies on the use of nanoparticles as photosensitiser carriers have demonstrated improved PDT efficacy in experimental cancer therapy. Experiments typically employ conventional monolayer cell culture but there is increasing interest in testing PDT using three dimensional (3D) cancer models. 3D cancer models can better mimic in vivo models than 2D cultures by for example enabling cancer cell interactions with a surrounding extracellular matrix which should enable the treatment to be optimised prior to in vivo studies. The aim of this review is to discuss recent research using PDT in different types of 3D cancer models, from spheroids to nano-fibrous scaffolds, using a range of photosensitisers on their own or incorporated in nanoparticles and nanodelivery systems

Achieving enhanced ionic mobility in nanoporous silica by controlled surface interactions

We report a strategy to enhance the ionic mobility in an emerging class of gels, based on robust nanoporous silica micro-particles, by chemical functionalization of the silica surface. Two very different ionic liquids are used to fill the nano-pores of silica at varying pore filling factors, namely one aprotic imidazolium based (1-methyl-3-hexylimidazolium bis(trifluoromethanesulfonyl)imide, C6C1ImTFSI), and one protic ammonium based (diethylmethylammonium methanesulfonate, DEMAOMs) ionic liquid. Both these ionic liquids display higher ionic mobility when confined in functionalized silica as compared to untreated silica nano-pores, an improvement that is more pronounced at low pore filling factors (i.e. in the nano-sized pore domains) and observed in the whole temperature window investigated (i.e. from −10 to 140 °C). Solid-state NMR, diffusion NMR and dielectric spectroscopy concomitantly demonstrate this effect. The origin of this enhancement is explained in terms of weaker intermolecular interactions and a consequent flipped-ion effect at the silica interface strongly supported by 2D solid-state NMR experiments. The possibility to significantly enhance the ionic mobility by controlling the nature of surface interactions is extremely important in the field of materials science and highlights these structurally tunable gels as promising solid-like electrolytes for use in energy relevant devices. These include, but are not limited to, Li-ion batteries and proton exchange membrane (PEM) fuel cells

Endolysosomal targeting of a clinical chlorin photosensitiser for light-triggered delivery of nano-sized medicines

A major problem with many promising nano-sized biotherapeutics including macromolecules is that owing to their size they are subject to cellular uptake via endocytosis, and become entrapped and then degraded within endolysosomes, which can significantly impair their therapeutic efficacy. Photochemical internalisation (PCI) is a technique for inducing cytosolic release of the entrapped agents that harnesses sub-lethal photodynamic therapy (PDT) using a photosensitiser that localises in endolysosomal membranes. Using light to trigger reactive oxygen species-mediated rupture of the photosensitised endolysosomal membranes, the spatio-temporal selectivity of PCI then enables cytosolic release of the agents at the selected time after administration so that they can reach their intracellular targets. However, conventional photosensitisers used clinically for PDT are ineffective for photochemical internalisation owing to their sub-optimal intracellular localisation. In this work we demonstrate that such a photosensitiser, chlorin e6, can be repurposed for PCI by conjugating the chlorin to a cell penetrating peptide, using bioorthogonal ligation chemistry. The peptide conjugation enables targeting of endosomal membranes so that light-triggered cytosolic release of an entrapped nano-sized cytotoxin can be achieved with consequent improvement in cytotoxicity. The photoproperties of the chlorin moiety are also conserved, with comparable singlet oxygen quantum yields found to the free chlorin

Population balance modeling of assembly formation; accounting for the H-NS protein oligomerization and DNA binding mechanisms

The results obtained in this study demonstrate H-NS oligomerization in solution is not sufficient in forming large structures of H-NS-DNA assemblies indicating oligomerization along bacterial DNA is crucial. We present a comprehensive and novel multi-scale modeling scheme to study protein-protein and protein-DNA interactions, with the focus on population balance modeling of assemblies formed by the H-NS protein and bacterial DNA. The model helps understanding how the concentration of H-NS influences the formation of H-NS-DNA assemblies. The presented model covers the two underlying molecular mechanisms involved in assembly formation, H-NS oligomerization in solution and H-NS-DNA binding. Within protein oligomerization interactions, protein molecules are entitled to dimerize, propagate, recombine and deform (break). In addition, DNA binding and unbinding interactions are included to account for formation of filaments along DNA. All mechanisms have been modeled with their associated forward (formation) and backward (deformation) interactions. The results obtained agree well with former experimental studies.</p

Flexible synthesis of cationic peptide-porphyrin derivatives for light-triggered drug delivery and photodynamic therapy

Efficient syntheses of cell-penetrating peptide-porphyrin conjugates are described using a variety of bioconjugation chemistries. This provides a flexible means to convert essentially hydrophobic tetrapyrolle photosensitisers into amphiphilic derivatives which are well-suited for use in light-triggered drug delivery by photochemical internalisation (PCI) and targeted photodynamic therapy (PDT)

Enhancing the efficacy of cytotoxic agents for cancer therapy using photochemical internalisation.

Photochemical internalisation (PCI) is a technique for improving cellular delivery of certain bioactive agents which are prone to sequestration within endolysosomes. There is a wide range of agents suitable for PCI-based delivery including toxins, oligonucleotides, genes and immunoconjugates which demonstrates the versatility of this technique. The basic mechanism of PCI involves triggering release of the agent from endolysosomes within the target cells using a photosensitiser which is selectively retained with the endolysosomal membranes. Excitation of the photosensitiser by visible light leads to disruption of the membranes via photooxidative damage thereby releasing the agent into the cytosol. This treatment enables the drugs to reach their intended subcellular target more efficiently and improves their efficacy. In this review we summarise the applications of this technique with the main emphasis placed on cancer chemotherapy