A qualitative stakeholder analysis of avian influenza policy in Bangladesh

Avian influenza is a major animal and public health concern in Bangladesh. A decade after development and implementation of the first national avian influenza and human pandemic influenza preparedness and response plan in Bangladesh, a two-stage qualitative stakeholder analysis was performed in relation to the policy development process and the actual policy. This study specifically aimed to identify the future policy options to prevent and control avian influenza and other poultry-related zoonotic diseases in Bangladesh. It was recommended that the policy should be based on the One Health concept, be evidence-based, sustainable, reviewed and updated as necessary. The future policy environment that is suitable for developing and implementing these policies should take into account the following points: the need to formally engage multiple sectors, the need for clear and acceptable leadership, roles and responsibilities, and the need for a common pool of resources and provision for transferring resources. Most of these recommendations are directed towards the Government of Bangladesh. However, other sectors, including research and poultry production stakeholders, also have a major role to play to inform policy-making and actively participate in the multi-sectoral approach

First Principles Studies toward the Design of Silylene Superbases: A Density Functional Theory Study

In this paper we have reported for the first time some designed silylene superbases using DFT calculations. These divalent Si­(II) compounds can act as powerful neutral organic superbases in the gas phase and in the solvent phase. The DFT calculations performed with the B3LYP/6-311+G**//B3LYP/6-31+G* level of theory showed that one of the designed silylene derivatives :Si­(NPY₃)₂ [Y = −NC­(NMe₂)₂] (<b>8</b>) can fall in the range of hyperbase with gas phase proton affinity ∼310 kcal/mol. In THF the calculated proton affinity of <b>8</b> was found to be 327.5 kcal/mol. The proton affinities computed at the B3LYP/6-311+G**//B3LYP/6-31+G* level for some simple silylenes have been found to be good agreement with the corresponding experimentally measured values. Phosphazene groups attached to the divalent silicon center of silylenes enhanced the basicity of the Si center significantly and further acted as a second protonation site. The calculated second proton affinity of the silylene derivative, <b>8</b> in THF was found to be 285.5 kcal/mol. We have shown that the dimerization and cyclization of such silyene superbases were less likely and the monomeric forms would be more stable than their corresponding dimers. The calculated proton affinities also showed a good correlation with the HOMO–LUMO energy gap and energy difference between the singlet and triplet states (Δ<i>E</i>_S‑T) of the silylene systems. The isodesmic reactions have been employed to examine the stability of the silylene molecules by calculating the silylene stabilization energy (SiSE). The reactivity of silylene molecules has been presented in terms of the nucleophilicity, electronegativity, and hardness of such systems. The Lewis basic properties of these silylene systems have also been explored

Authentication of meat and meat products using molecular assays: A review

Meat species identification and animal authentication in meat products is an important topic that should be addressed in order to promote fair trade and allow customers to make informed decisions. It is also a major concern for practicing religious people. Protein or DNA measurements are used in many analytical procedures. Electrophoretic, chromatographic, and immunological approaches based on protein fractions are typically ineffective in distinguishing closely related meat species in processed foods. Molecular techniques for meat species identification have gotten a lot of interest in recent years because of their high sensitivity and specificity, as well as their short processing time and inexpensive cost. This review discusses an overview of the most common DNA and PCR-based approaches used to validate the authenticity of meat and meat products to date

Design, Fabrication and Evaluation of Drug Release Kinetics from Aceclofenac Matrix Tablets using Hydroxypropyl Methyl

ABSTRACT: The objective of this study was to develop a sustained release matrix tablet of aceclofenac using hydroxypropyl methylcellulose (HPMC K15M and HPMC K100M CR) in various proportions as release controlling factor by direct compression method. The powders for tableting were evaluated for angle of repose, loose bulk density, tapped bulk density, compressibility index, total porosity and drug content etc. The tablets were subjected to thickness, weight variation test, drug content, hardness, friability and in vitro release studies. The in vitro dissolution study was carried out for 24 hours using United States Pharmacopoeia (USP) 22 paddle-type dissolution apparatus in phosphate buffer (pH 7.4). The granules showed satisfactory flow properties, compressibility index and drug content etc. All the tablets complied with pharmacopoeial specifications. The results of dissolution studies indicated that the formulations F-2 and F-3 could extend the drug release up to 24 hours. By comparing the dissolution profiles with the marketed product, it revealed that the formulations exhibited similar drug release profile. From this study, a decrease in release kinetics of the drug was observed when the polymer concentration was increased. Kinetic modeling of in vitro dissolution profiles revealed the drug release mechanism ranges from diffusion controlled or Fickian transport to anomalous type or non-Fickian transport, which was only dependent on the type and amount of polymer used. The drug release followed both diffusion and erosion mechanism in all cases. The drug release from these formulations was satisfactory after 3 months storage in 40 0 C and 75 % RH. Besides, this study explored the optimum concentration and effect of polymer(s) on acelofenac release pattern from the tablet matrix for 24 hour period. Key words: Aceclofenac, sustained release, hydrophillic matrix, HPMC, direct compression

Combining ability and heterosis for some quantitative traits in experimental maize hybrids

In rabi season 2012, six diversed maize inbred lines were crossed in all possible combinations without reciprocals by using a half diallel mating design to obtain 15 single cross. Inbred parents and their F1 single crosses with a check were evaluated in rabi season 2013 to evaluate the role of general and specific combin-ing ability and heterosis for some quantitative traits. Significant general combining ability variances was observed only for cob height and specific combining ability variances were observed for plant height, cob height, cob length, cob girth, number of kernels per cob, cob weight and hundred grain weight. The GCA/SCA ratio was less than unity for all studied traits except shelling percentage; this means that these traits are pre-dominantly controlled by non-additive gene action. Based on GCA estimates, it could be concluded that the best combiners were ML01, ML05 and ML29 inbred lines for most of the studied traits. This result indi-cated that these inbred lines could be considered as good combiners for improving these traits. Significant positive SCA effects were found for all studied traits except number of kernels per row and shelling percent-age. Based on SCA effects, it could be concluded that the crosses ML01×ML02, ML02×ML05, ML02×ML29 and ML05×ML15 could be exploited by the maize breeders to increase maize yield. Three F1 hybrids such as ML02×ML15, ML02×ML29 and ML05×ML15 proved to be the outstanding hybrids to immediate further steps for commercial cultivation. In a conclusive decision the F1 hybrid, ML02×ML29 was the best combina-tion as evaluated through combining ability and standard heterosis

A Brief History of and Insight in the Choice of Sensitizers/Dyes for Dye Sensitized Solar Cells

In this review, a discussion on renewable sources of energy with clear focus on solar cell applications is presented. Especially, possible future directions for development of dye-sensitized solar cells (DSSCs) are discussed. Dye-sensitized solar cells have become an important topic of research due to its high importance in energy conversion. Current DSSCs are based on either metal dye sensitizers, metal-free organic dyes or natural dyes. They have been extensively studied due to their low cost, simple preparation methodology, low toxicity, and ease of production. Still there is a need to find more abundant DSSC materials that at same time exhibit long-term stability. Computational studies have been an important ally for developing/designing new dye sensitizers. They are reviewed here with a special emphasis on the benefit of such studies. The conceptual understanding of development and working principle of photoactive DSSC materials are the primary feature of the review followed by examples of studies on different dye sensitizers using scarce to abundant metal based dyes and metal free organic dyes with donor-π-acceptor geometries for both n- and p-type DSSCs. The proper choice of organic dyes including donor, spacer, or acceptor is discussed and a prospective on dual donor based dyes is presented

New Ru(II)/Os(II)-polypyridyl complexes for coupling to TiO₂ surfaces through acetylacetone functionality and studies on interfacial electron-transfer dynamics

New Ru(II)- and Os(II)-polypyridyl complexes have been synthesized with pendant acetylacetone (acac) functionality for anchoring on nanoparticulate TiO₂ surfaces with a goal of developing an alternate sensitizer that could be utilized for designing an efficient dye-sensitized solar cell (DSSC). Time-resolved transient absorption spectroscopic studies in the femtosecond time domain have been carried out. The charge recombination rates are observed to be very slow, compared with those for strongly coupled dye molecules having catechol as the anchoring functionality. The results of such studies reveal that electron-injection rates from the metal complex-based LUMO to the conduction band of TiO₂ are faster than one would expect for an analogous complex in which the chromophoric core and the anchoring moiety are separated with multiple saturated C–C linkages. Such an observation is rationalized based on computational studies, and a relatively smaller spatial distance between the dye LUMO and the TiO₂ surface accounted for this. Results of this study are compared with those for analogous complexes having a gem-dicarboxy group as the anchoring functionality for covalent binding to the TiO₂ surface to compare the role of binding functionalities on electron-transfer dynamics

Design of Efficient Metal-Free Organic Dyes Having an Azacyclazine Scaffold as the Donor Fragment for Dye-Sensitized Solar Cells

The energy conversion efficiency of dye-sensitized solar cells derived from organic dye molecules has seen immense interest recently. In this work, we report a series of organic donor molecules with enhanced energy conversion efficiency using π-spacers and cyanoacrylic acid as an anchoring group (<b>2</b>–<b>6</b>). Density functional theory (DFT) and time-dependent DFT calculations of these molecules have been performed to examine their electronic structures and absorption spectra before and after binding to the semiconductor titanium dioxide surface. The computational results suggest that dyes <b>4</b> and <b>6</b> have a larger driving force (Δ<i>G</i>_inject = −1.66 and −1.80 eV, respectively) and light-harvesting efficiency (LHE = 0.99) in the series of donor molecules studied. Thus, these dyes should possess a larger short-circuit photocurrent density (<i>J</i>_sc) compared to the other examined dyes. The reported Δ<i>G</i>_inject (−1.62 eV) and LHE (0.98) for compound <b>1</b>, calculated with the same level of theory, were lower than those of the designed <b>4</b> and <b>6</b> dyes. Furthermore, the DFT calculations showed that the open-circuit photovoltage (<i>V</i>_oc) is improved with the vertical dipole moment and number of photoinjected electrons for <b>4</b> and <b>6</b>. Dyes <b>4</b> and <b>6</b> are expected to exhibit high solar-energy-to-electricity conversion