Distinct dynamic behaviors of water molecules in hydrated pores

Water molecules confined inside narrow pores are of great importance in understanding the structure, stability, and function of water channels. Here we report that besides the H-bonding water that structures the pore, the permanent presence of a significant, fast-moving fraction of incompletely H-bonded water molecules inside the pore should control the free entry and exit of water. This is achieved by means of complementary DSC and solid-state NMR studies. We also present compelling evidence from X-ray diffraction data that the cluster formed by six water molecules in the most stable cage-like structure is sufficiently hydrophobic to be stably adsorbed in a nonpolar environment.     

Morphology and crystallization kinetics of compact (HGW) and porous (ASW) amorphous water ice

An investigation of porosity and isothermal crystallization kinetics of amorphous ice produced either by background water vapour deposition (ASW) or by hyperquenching of liquid droplets (HGW) is presented. These two types of ice are relevant for astronomical ice research (Gálvez et al., Astrophys. J., 2010, 724, 539) and are studied here for the first time under comparable experimental conditions. From CH(4) isothermal adsorption experiments at 40 K, surface areas of 280 ± 30 m(2) g(-1) for the ASW deposits and of 40 ± 12 m(2) g(-1) for comparable HGW samples were obtained. The crystallization kinetics was studied at 150 K by following the evolution of the band shape of the OD stretching vibration in HDO doped ASW and HGW samples generated at 14 K, 40 K and 90 K. Comparable rate constants of ～7 × 10(-4) s(-1) were obtained in all cases. However a significant difference was found between the n Avrami parameter of the samples generated at 14 K (n～ 1) and that of the rest (n > 2). This result hints at the possible existence of a structurally different form of amorphous ice for very low generation temperatures, already suggested in previous literature works.     

Enzymatic inhibitory activity of Ficus deltoidea leaf extract on matrix metalloproteinase-2, 8 and 9

Dysregulation of matrix metalloproteinases (MMPs) activity is known in many pathological conditions with which most of the conditions are related to elevate MMPs activities. Ficus deltoidea (FD) is a plant known for its therapeutic properties. In order to evaluate the therapeutic potential of FD leaf extract, we study the enzymatic inhibition properties of FD leaf extract and its major bioactive compounds (vitexin and isovitexin) on a panel of MMPs (MMP-2, MMP-8 and MMP-9) using experimental and computational approaches. FD leaf extract and its major bioactive compounds showed pronounced inhibition activity towards the MMPs tested. Computational docking analysis revealed that vitexin and isovitexin bind to the active site of the three tested MMPs. We also evaluated the cytotoxicity and cell migration inhibition activity of FD leaf extract in the endothelial EA.hy 926 cell line. Conclusively, this study provided additional information on the potential of FD leaf extract for therapeutical application.     

Effect of additives on the performance of Dyckerhoff cement,Class G,submitted to simulated hydrothermal curing

Stability of Dyckerhoff cement Class G partially substituted (15 mass%) by metakaolin (MK), silica fume (SF) and ground granulated blast-furnace slag (BFS) was investigated after 7 days of curing under standard and two different autoclaving conditions. Mercury intrusion porosimetry, X-ray diffraction analysis and combined thermogravimetric–differential scanning calorimetry were used to evaluate pore structure development, compressive strength and their dependence on the type of additives in relation to the particular phase composition. Hydrothermal curing led to the formation of α-C₂SH and jaffeite, mostly in the case of referential samples and compositions with addition of slowly reacting BFS. Whilst modest hydrothermal curing (0.6 MPa, 165 °C) favoured formation of α-C₂SH, larger amounts of jaffeite were determined after curing at the highest used pressure and temperature (2.0 MPa, 220 °C). Undesired transformation of primary hydration products was prevented especially by addition of highly reactive and very fine SF. Particular composition attained the best pore structure characteristics and compressive strength after curing at 0.6 MPa and 165 °C. Formation of more stable phases with C/S ratio close to 1 was proved by wollastonite formation during DSC analyses. More severe conditions of curing, however, led to the significant deterioration of microstructure and strength of corresponding sample, probably due to the formation of trabzonite, killalaite and zoisite. Considering the values of hydraulic permeability coefficient and compressive strength, replacement of cement by MK improved significantly the properties of cement when compared with the referential as well as with other blended compositions under the mentioned curing conditions.     

The use of molecularly imprinted polymers for the multicomponent determination of endocrine‐disrupting compounds in water and sediment

The method employing molecularly imprinted polymers for the extraction and clean up of endocrine‐disrupting compounds (estrogens, bisphenol A, and alkylphenols) from water and sediment is described. The identical extraction/clean‐up and LC‐MS/MS condition were used for the analysis of both types of samples. The method showed high recoveries ranging from 90 to 99% with excellent precision (intrabatch: 3.6–9.3%; interbatch: 5.6–11.4% for water; intrabatch: 4.3–8.5%; interbatch: 6.1–9.6% for sediment). The LOD was in the range of 0.7–1.9 ng/L and 0.3–0.6 ng/g for water and sediment, respectively. Overall extraction on molecularly imprinted polymers substantially enhanced sample clean‐up. The difference in efficiency of clean‐up was particularly pronounced when a large sample volume/weight was extracted and analyzed. Finally, the method was successfully applied for the analysis of 20 water and sediment samples.     

Synthesis of octahydroquinolines through the Lewis acid catalyzed reaction of vinyl allenes and imines

The reaction of vinyl allenes with imines under Lewis acid catalysis has been explored. Vinyl allenes in which the allenic portion of the molecule is tri- or tetrasubstituted gave octahydroquinoline derivatives as single isomers together with a minor compound formed by an ene reaction of the imine with the allene. Compounds in which the allene is 1,3-disubstituted do not react under the conditions assayed.     

Radiation pasteurised oil palm empty fruit bunch fermented with Pleurotus sajor-caju as feed supplement to ruminants

In solid state fermentation, Pleurotus sajor-caju has been found to be able to degrade at least 30% oil palm empty Fruit Bunch (EFB) fibre leaving 70 % useful materials. Conditions under which fermentation carried out were investigated. It was found that, in the temperature range between 25– 28 °C, relative ph between 6–8, moisture between 60–70 % and medium composition of CaCO₃: rice bran 2 %: 5 % were the optimum conditions. The results showed in fermented products that, there were substantial reduction in cellulosic component such as Crude Fiber (CF, 18 %); Acid Detergent Fibre (ADF, 45 %), Neutral Detergent Fibre (NDF, 61 %) and Acid Detergent Lignin (ADL, 14 %). However, Crude Protein (CP, 10%) increased resulted from single cell protein enrichment of mycelial microbial mass. The mass reductions of substrate in fermentation process corresponds to the CO₂ released during fermentation. Hence, attributable to the decreased in content of CF, ADF, NDF, and ADL. The digestibility study has also been carried out to determine the useful level of this product to ruminant. Aflatoxin content was detected low in both the initial substrates and products. Based on nutritional value and low content of aflatoxin, the product is useful as a source of roughage to ruminant.     

Spectrofluorimetric Determination Of Indium with 1,2,4-Trihydroxyanthraquinone

A new method for the spectrofluorimetric determination of indium by formation of a fluorescent 1:1 complex with 1,2,4-trihydroxyanthraquinone is proposed. The complex is formed in a mixed, 60:40 v/v acetone-water medium at pH 3.8 provided by an acetic acid-sodium acetate buffer. The calibration graph is linear between 10 and 600 ng/ml. The effect of potential interferents on the determination was assessed and the proposed method was applied to the determination of indium in synthetic samples.