Design of new competitive dengue ns2b/ns3 protease inhibitors-a computational approach

Dengue is a serious disease which has become a global health burden in the last decade. Currently, there are no approved vaccines or antiviral therapies to combat the disease. The increasing spread and severity of the dengue virus infection emphasizes the importance of drug discovery strategies that could efficiently and cost-effectively identify antiviral drug leads for development into potent drugs. To this effect, several computational approaches were applied in this work. Initially molecular docking studies of reference ligands to the DEN2 NS2B/NS3 serine protease were carried out. These reference ligands consist of reported competitive inhibitors extracted from Boesenbergia rotunda (i.e., 4-hydroxypanduratin A and panduratin A) and three other synthesized panduratin A derivative compounds (i.e., 246DA, 2446DA and 20H46DA). The design of new lead inhibitors was carried out in two stages. In the first stage, the enzyme complexed to the reference ligands was minimized and their complexation energies (i.e., sum of interaction energy and binding energy) were computed. New compounds as potential dengue inhibitors were then designed by putting various substituents successively on the benzyl ring A of the reference molecule. These substituted benzyl compounds were then computed for their enzyme-ligand complexation energies. New enzyme-ligand complexes, exhibiting the lowest complexation energies and closest to the computed energy for the reference compounds, were then chosen for the next stage manipulation and design, which involved substituting positions 4 and 5 of the benzyl ring A (positions 3 and 4 for 2446DA) with various substituents.     

Estimating and mitigating agriculture GHG emissions: uncertainties and policy reforms

Global climate change has been one of the challenging environmental concerns facing policy makers in the past decade. The characterization of the wide range of greenhouse gas emissions sources and sinks as well as their behavior in the atmosphere remains an on‐going activity in many countries. Lebanon, being a signatory to the Framework Convention on Climate Change, is required to submit and regularly update a national inventory of greenhouse gas emissions sources and removals. Accordingly, an inventory of greenhouse gases from various sectors was conducted following the guidelines set by the United Nations Intergovernmental Panel on Climate Change. The inventory indicated that the agriculture sector contributes about seven percent to the total greenhouse gas emissions. This paper proposes mitigation scenarios to reduce emissions from this sector based on country‐specific technical, economic and environmental characteristics. Economic evaluation and uncertainty in the emission estimation process as well as policy reforms are also addressed in the context of agricultural emissions reduction.     

Durability of green polyurethane adhesive bonded aluminum alloy in dry and hydrothermal ageing conditions

Polyurethane (PU) adhesives were prepared from the reaction of polycaprolactone (PCL) polyols based on palm kernel oil based polyesteramide (PPKO) with an aromatic and cycloaliphatic diisocyanate. Four different formulations of PU adhesives were prepared by varying the NCO : OH ratio, in order to investigate the effects of NCO : OH ratios on adhesion strength. The adhesive strength of metal–metal bonding both in dry and hydrothermal ageing—was determined by single lap shear joint testing. The resistance to hydrolysis of the PU adhesives was determined by performing water absorption tests. The water absorption test samples suggested that the durability of the adhesives correlated to lower water absorption due to higher NCO content. The correlation between the crosslinking of the PU network and adhesive strength was also studied by performing swelling tests. The higher NCO content showed that, the higher crosslink density of PUs led to higher cohesion and adhesion strengths. PU1.7 showed optimal properties in terms of durability and resistance to hydrolysis, whereas PU2.0 revealed deterioration in durability and resistance to hydrolysis due to the presence of greater micro‐voids content in the PU2.0 matrix. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41151.     

Dual codes of systematic group codes over abelian groups

For systematic codes over finite fields the following result is well known: If [I¦P] is the generator matrix then the generator matrix of its dual code is [ ?P ^tr¦I]. The main result is a generalization of this for systematic group codes over finite abelian groups. It is shown that given the endomorphisms which characterize a group code over an abelian group, the endomorphisms which characterize its dual code are identified easily. The self-dual codes are also characterized. It is shown that there are self-dual and MDS group codes over elementary abelian groups which can not be obtained as linear codes over finite fields.     

Dual codes of systematic group codes over abelian groups

For systematic codes over finite fields the following result is well known: If [I∣P] is the generator matrix then the generator matrix of its dual code is The main result is a generalization of this for systematic group codes over finite abelian groups. It is shown that given the endomorphisms which characterize a group code over an abelian group, the endomorphisms which characterize its dual code are identified easily. The self-dual codes are also characterized. It is shown that there are self-dual and MDS group codes over elementary abelian groups which can not be obtained as linear codes over finite fields. Received March 7, 1995; revised version April 3, 1996     

Trigeminal neuralgia. A retrospective survey of a sample of patients in Singapore and Malaysia

We report a case of synovial sarcoma with extensive myxoid change diagnosed by fine-needle aspiration. The patient is a 46-year-old woman who presented with a right paratibial mass. Aspiration cytology demonstrated a spindle cell neoplasm consistent with a synovial sarcoma but containing a prominent myxoid matrix. The clinical suspicion and cytologic diagnosis of a synovial sarcoma was confirmed by histologic and immunohistochemical findings. The cytologic differential diagnosis of spindle cell neoplasms with extensive myxoid change should be broadened to include synovial sarcoma.     

Variations of foF2 prior to earthquakes

Earthquakes are a kind of rapid and huge energy release process of the Earth’s internal energy. The changes associated to this energy release affect the atmosphere and ionosphere around the earthquake zone. In this study, the ionospheric foF2 can be used to analyze the change in the foF2 before and during earthquakes. The earthquakes in Sumatra in 2007 and in Italy in 2002 were chosen in this analysis. The raw data taken from ionosondes were used to measure the virtual height of the foF2. The comparison analysis of the foF2 was done by observing the values before and during the earthquakes on various dates and times when the earthquakes occurred. The results show that an earthquake does affect the ionospheric value of the foF2, where the foF2 value is lower than the ordinary daily value. The value decreases two hours before the earthquake and remains at a low level of 2.7 MHz during the earthquake. This has been shown by an analysis that was conducted at different times, dates and locations.