Posterior simulation via the exponentially tilted signed root log-likelihood ratio

We explore the use of importance sampling based on exponentially tilted signed root log-likelihood ratios for Bayesian computation. Approximations based on exponentially tilted signed root log-likelihood ratios are used in two distinct ways; firstly, to define an importance function with antithetic variates and, secondly, to define suitable control variates for variance reduction. These considerations give rise to alternative simulation-consistent schemes to other importance sampling techniques (for example, conventional and/or adaptive importance sampling) for Bayesian computation in moderately parameterized regular problems. The schemes based on control variates can also be viewed as usefully supplementing computations based on asymptotic approximations by supplying external estimates of error. The methods are illustrated by a censored regression model and a more challenging 12-parameter nonlinear repeated measures model for bacterial clearance.     

A Novel Distachionate from Breynia distachia Treats Inflammations by Modulating COX-2 and Inflammatory Cytokines in Rat Liver Tissue

Breynia distachia is a plant of genus Breynia belonging to family Phyllanthaceae. This study was conducted to isolate and examine the anti-inflammatory attributes of the roots of Breynia distachia. Methanol extract from roots were prepared by simple maceration. For phytochemical studies, isolation, purification, structure elucidation, metal analysis, total phenolic content, and solubility test were done by chromatographic and spectroscopic techniques. Anti-inflammatory activity was evaluated by cotton pallet edema model and carrageenan paw edema model, and antioxidant potential was evaluated by DPPH, FRAP, and ABTS antioxidants assays. Metal analysis of BD.Me revealed the presence of Na > Mg > K > Mn > Fe = Zn in respective order. Four phytochemicals such as gallic acid, quercetin, sinapic acid, and p-coumaric acid are found in Breynia distachia. Quercetin is present in relatively larger quantity, and shows antioxidant activity by reducing the ferric iron to ferrous iron. Novel distachionate shows high antioxidant activity in ABTS assay by reducing reactive oxygen species. Quantitative or qualitative analysis performed by HPLC indicates the ascending peaks or presence of secondary products (metabolites) respectively. Histopathology analysis of liver, spleen, heart, and kidney was done, revealing mild inflammations in spleen and liver, and no cytotoxicity in heart and kidney. Oral administration of BD.Me and ditachionate significantly inhibits the carrageenan and cotton pellet-induced paw edema in 1st and 2nd h with (ns = p > 0.05) than control. After 3rd, 4th, 5th, and 6th h, BD.Me and ditachionate showed inhibition of paw edema in a highly significant (*** = p < 0.001) manner as compared to control. In cotton-pellet edema model, distachionate shows a %inhibition of 57.3% at a dose level of 5 mg/kg. Docking values obtained from distachionate-COX-2 complex suggest a potent inhibitor evaluated for this protein. The distachionate shows effective anti-inflammatory activity. Methanol extracts of roots showed significant lipoxygenase inhibitory activity by IC₅₀ values of 155.7 ± 0.55 and 132.9 ± 0.33 μg/mL. Data from various in vitro and in vivo models suggest that novel distachionate isolated from Breynia distachia shows strong antioxidant and anti-inflammatory activities; it should be further studied for the exploration of its medicinal potential.     

Green synthesis of zinc oxide nanoflowers using Hypericum triquetrifolium extract: characterization,antibacterial activity and cytotoxicity against lung cancer A549 cells

Zinc oxide nanoparticles have attracted significant interest in recent years due to their unique multifunctional chemical and physical properties along with their biological activities. This study demonstrated for the first time the biogenetic synthesis of zinc oxide nanoparticles by utilization of the methanolic extract of Hypericum triquetrifolium (HT). The obtained nanoparticles (HT-ZnO) were characterized by ultraviolet–visible spectroscopy (UV–Vis), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), dynamic light scattering (DLS), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and transmission electron microscopy (TEM). The shape of the resulted nanoparticles is fusiform nanoflowers with an average hydrodynamic size of 275.46 ± 0.20 nm and a zeta potential of −8.23 ± 0.26 mV. SEM micrographs revealed that HT-ZnO nanoflowers have a multi-process structure in which one of the processes is large and the others have similar smaller dimensions. The synthesized nanoflowers have an average length of 312.28 ± 78.93 nm and the tip of its processes has a width of 48.69 ± 9.71 nm. The antimicrobial activity of HT-ZnO nanoflowers was performed using microbroth dilution format. It showed a bactericidal mode of action against Gram-positive Staphylococcus aureus and Enterococcus faecalis with MIC/MBC values of 20 μg/mL and 5 μg/mL, respectively. MTT assay had revealed that HT-ZnO nanoflowers caused a dose-dependent decline in the viability of A549 adenocarcinomic human alveolar basal epithelial cells with an IC₅₀ value of 20.45 μg/mL. The effect of HT-ZnO nanoflowers on the migration and colony formation abilities against the same cells was evaluated as well. In conclusion, zinc oxide nanoflowers were successfully synthesized using methanolic extract of H. triquetrifolium. The resulting particles showed a bactericidal effect against Gram-positiveS. aureus and E. faecalis and a cytotoxic activity against A549 cells.     

Mesoporous γ‐Iron Oxide Nanoparticles for Magnetically Triggered Release of Doxorubicin and Hyperthermia Treatment

Mesoporous iron‐oxide nanoparticles (mNPs) were prepared by using a modified nanocasting approach with mesoporous carbon as a hard template. mNPs were first loaded with doxorubicin (Dox), an anticancer drug, and then coated with the thermosensitive polymer Pluronic F108 to prevent the leakage of Dox molecules from the pores that would otherwise occur under physiological conditions. The Dox‐loaded, Pluronic F108‐coated system (Dox@F108‐mNPs) was stable at room temperature and physiological pH and released its Dox cargo slowly under acidic conditions or in a sudden burst with magnetic heating. No significant toxicity was observed in vitro when Dox@F108‐mNPs were incubated with noncancerous cells, a result consistent with the minimal internalization of the particles that occurs with normal cells. On the other hand, the drug‐loaded particles significantly reduced the viability of cervical cancer cells (HeLa, IC₅₀=0.70 μm ), wild‐type ovarian cancer cells (A2780, IC₅₀=0.50 μm ) and Dox‐resistant ovarian cancer cells (A2780/AD, IC₅₀=0.53 μm ). In addition, the treatment of HeLa cells with both Dox@F108‐mNPs and subsequent alternating magnetic‐field‐induced hyperthermia was significantly more effective at reducing cell viability than either Dox or Dox@F108‐mNP treatment alone. Thus, Dox@F108‐mNPs constitute a novel soft/hard hybrid nanocarrier system that is highly stable under physiological conditions, temperature‐responsive, and has chemo‐ and thermotherapeutic modes of action.     

Modeling of cumulative release on long term leaching behaviour of selected oil sludge from crude oil terminal and petroleum refining plant

Management of oil sludge containing environmentally toxic elements is a major problem in crude oil processing industry. Oil sludge samples from the petroleum refinery plant in Melaka and crude oil terminal in Sarawak were analysed. The aim of present work is to study long term leaching behaviour of arsenic (As), cobalt (Co), chromium (Cr) and zinc (Zn) from oil sludge. Tank leaching test was carried out and the samples were analysed using inductively coupled plasma-mass spectrometry (ICP-MS). The results were studied using LeachXS software to plot the graphs of elements concentration in order to study the leaching behaviour of toxic elements in oil sludge. The long term leaching (100 years) modeling was calculated using equations referred to National Institute of Public Health and the Environment Bilthoven (RIVM) and the results were plotted for cumulative release in different areas of oil sludge. Tank leaching test of the oil sludge samples from petroleum refinery plant in Melaka showed concentrations of As, Co, Cr and Zn ranging from 0.205 to 1.102, 0.031–0.454, 0.016–0.086 and 0.409–8.238 mg/l, respectively while the concentrations of As, Co, Cr and Zn in oil sludge samples from crude oil terminal in Sarawak were in the range of 0.002–0.089, 0.001–0.033, 0.006–0.016 and 0.100–2.744 mg/l, respectively. On the other hand, results on cumulative release from the modeling of long term leaching (100 years) showed that As, Co, Cr and Zn concentrations were proportional to the quantity of oil sludge. In conclusion, during extrapolation of release of toxic elements using the data in the laboratory, several other factors were taken into account to suit environmental conditions such as soil moisture, the negative logarithm of the effective diffusion coefficient (pD_e) and temperature, while the long-term behaviour of As, Co, Cr and Zn was proportional to the quantity of oil sludge to be disposed off.     

Supported Organometallic Complexes. XXXVI [1] Diaminediphosphineruthenium(II) Interphase Catalysts for the Hydrogenation of α, β‐Unsaturated Ketones

The T—silyl functionalized diamine‐bis(ether‐phosphine)ruthenium(II) complexes 1a(T ° ) — 1g(T ° ) (Scheme 1) were sol‐gel processed in the presence of different amounts of the co‐condensation agents CH₃Si(OMe)₃ (Me—T ° ) and (MeO)₂SiMe—(CH₂)₆—MeSi(OMe)₂ (D ° —C₆—D ° ) to produce a library of the interphase catalysts X1a — X1c , X2a — X2g , and X3a — X3g . Due to the remarkable electronic and steric effects of the co‐ligands on the catalytic activity of such complexes, a series of aliphatic and aromatic diamines was selected. The new polymers were investigated by multinuclear CP/MAS solid‐state NMR spectroscopy as well as by EXAFS, EDX, SEM, and BET methods. Selected interphase catalysts show high activities and selectivities in the hydrogenation of trans‐4‐phenyl‐3‐butene‐2‐one.     

Instrumental neutron activation analysis of environmental samples using thek 0-standardization method

The use of thek ₀-standardization method in instrumental neutron activation analysis gives good accuracy and precision. The analysis time can be reduced drastically by employing software for thek ₀-standardization calculations. In this work samples were irradiated in a TRIGA reactor and the gamma spectrum was analysed by Sampo 90 and thek ₀-standardization by the KAYZERO/SOLCOI code (DSM Research). The efficiency measurement and the peak to total ratio at the reference and other geometries were measured and tested for their accuracy by analysing some reference materials. Reference materials such as SRM 1572 (Citrus leaves), SRM 1573 (Tomato leaves), SRM 1575 (Pine needles), IAEA Soil-7 (Soil) and SRM 1646 (Estuarine sediment) were analysed for the major, minor and trace element contents. The results were in good agreement with the certified or literature values. The recently released IAEA 140 (Sea plant homogenates) was also analysed for 28 elements.     

Soluble peptidyl phosphoranes for metal-free, stereoselective ligations in organic and aqueous solution

Protocols for solid-phase syntheses of soluble peptidyl phosphoranes are presented. Various supported phosphoranylidene acetates were prepared on Rink amide or via alkylation of trialkyl- and triarylphosphines with bromoacetyl Wang ester. C-Acylation was conducted racemization-free with activated Fmoc-amino acids, followed by SPPS (solid-phase peptide synthesis). Acidic conditions released decarboxylated peptidyl phosphoranes into solution. The protocol allowed for the electronic variation of peptidyl phosphoranes which were investigated in ligation reactions with azides in organic and aqueous solvents.