Postmortem muscle cells die through apoptosis

Several reports suggested the activation of caspases in postmortem muscle implicating the onset of a caspase-dependent cell death process after animal bleeding. It has been further well established that apoptosis and necrosis are the two major cell death pathways. The questions addressed in the present work were as follows: (a) in postmortem muscle, do cells die as in vivo? and (b) if so, by which dying process this goal is achieved? Selected hallmarks of apoptosis (phosphatidylserine externalization (PS), cell shrinkage, actin degradation) were analyzed in postmortem rat muscles and compared to usual cell behavior in apoptotic and necrotic processes. Results presented clearly demonstrate a rapid PS externalization and cell shrinkage extending during the first 24 h postexsanguination together with a progressive degradation of cytoskeletal and thin filaments of actin. It was therefore concluded that, in postmortem muscle, cells commit suicide soon after animal bleeding through apoptosis.     

LCA-based environmental assessment of the use and maintenance of heating and ventilation systems in Dutch dwellings

Buildings contribute significantly to the human-induced environmental burden. This comes not only from construction and demolition but also from activities throughout the operational phase – building maintenance and energy use for climate control. This paper describes how life cycle assessment (LCA) methodology can be applied to quantitatively assess the environmental performance of the use and maintenance of heating and ventilation systems. The studied climate systems include individual non-condensing boilers, condensing boilers and heat pumps on exhaust air for heating and hot tap water combined with either collective mechanical exhaust ventilation or individual balanced ventilation with heat recovery. This study shows that a heat pump causes the highest environmental burden of all the assessed climate systems due to the electricity needed for operation, high material content of the system and the refrigerant used. If the electricity used by the heat pump is generated fully by local photovoltaic cells, environmental performance will improve, but not for all environmental impact categories. Climate systems that reduce energy demand for heating, such as ventilation with heat recovery, will reduce the environmental impact related to energy use for space heating. However, if the electricity used to operate the system increases, along with the material content of the systems and distribution networks, other environmental impact categories than those related to space heating will also increase. Finally, maintenance frequency and related transportation of maintenance workers have a marginal effect on total environmental impact.     

Anticancer activity of silver-N-heterocyclic carbene complexes: caspase-independent induction of apoptosis via mitochondrial apoptosis-inducing factor (AIF)

Fourteen silver(I) complexes bearing N-heterocyclic carbene (NHC) ligands were prepared and evaluated for anticancer activity. Some of these were found to exhibit potent antiproliferative activity toward several types of human cancer cell lines, including drug-resistant cell lines, with IC(50) values in the nanomolar range. An initial investigation into the mechanism of cell death induced by this family of silver(I) complexes was carried out. Cell death was shown to result from the activation of apoptosis without involvement of primary necrosis. In HL60 cells, silver-NHCs induce depolarization of the mitochondrial membrane potential (ΔΨ(m)) and likely allow the release of mitochondrial proteins to elicit early apoptosis. This effect is not related to the overproduction of reactive oxygen species (ROS). In addition, apoptosis is not associated with the activation of caspase-3, but is triggered by the translocation of apoptosis-inducing factor (AIF) and caspase-12 from mitochondria and the endoplasmic reticulum, respectively, into the nucleus to promote DNA fragmentation and ultimately cell death. No modification in cell-cycle distribution was observed, indicating that silver-NHCs are not genotoxic. Finally, the use of a fluorescent complex showed that silver-NHCs target mitochondria. Altogether, these results demonstrate that silver-NHCs induce cancer cell death independent of the caspase cascade via the mitochondrial AIF pathway.     

The magic thicknesses of θ′ precipitates in Sn-microalloyed Al-Cu

θ′ is an effective strengthening precipitate phase in high-strength Al alloys; unfortunately its nucleation is difficult and usually requires assistance, such as that provided by Sn in Sn-microalloyed Al-Cu. In order to clarify the mechanisms by which Sn promotes the nucleation of θ′, we investigated the structure and thickness of θ′ precipitates in a Al-1.7 at.% Cu alloy with trace additions of Sn (0.01 at.%). Scanning transmission electron microscopy imaging reveals that θ′ platelets recently nucleated at 160 and 200 °C exhibit a discrete distribution of specific, or “magic”, thicknesses, corresponding to minima in the residual volumetric and shape misfit strain. This observation is unique to the Sn-assisted nucleation of θ′: θ′ platelets that undergo growth or form in the Sn-free alloy do not display this discrete distribution, although preference for the magic thicknesses persists. Direct evidence is presented that Sn does not accommodate volumetric misfit strain. Instead, it is shown that Sn in its solute form reduces either the interfacial energy of θ′ and/or the transformation shape strain associated with thicknesses intermediate to the magic thicknesses.     

BASETY: Extension et typicalité des exemplaires pour 21 catégories d'objets.

Basety is a French semantic database of exemplars of 21 categories of objects, with a typicality index associated with each exemplar. These 21 semantic categories are animals, trees, weapons, buildings, flowers, fruits, insects, instruments of music, games, toys, vegetables, mammals, furnitures, birds, tools, fish, occupation, containers, sports, vehicles, and clothes. Basety was made up with two groups of 18-to-30 years old French participants, a first group of three subgroups of 100 participants producing exemplars for 7 × 3 categories while a second group of 80 participants evaluating membership of these exemplars. Typicality was computed as the number of occurrences of the exemplar within the set of the five exemplars participants were first producing. Cronbach's coefficient of reliability indicates an internally consistent scale and number of exemplars is correlated with membership ratings: the more the participants of the first group produced exemplars, the more the participants of the second group agreed on the degree of membership of these exemplars. BASETY appears to be a consistant and valid database for French semantic research. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A HPLC-UV method for the determination of angiotensin I-converting enzyme (ACE) inhibitory activity

To determine the angiotensin-converting enzyme (ACE) inhibitory activity of a fish hydrolysate, different methods were tested. Finally, a sensitive, extraction-free HPLC method using N-(3-[2-furylacryloyl)-Phe-Gly-Gly (FAPGG) as substrate was preferred. This method relies on the UV-titration of the peptide 2-furylacryloyl-l-Phe (FAP) resulting from the hydrolysis of the FAPGG after a chromatographic separation on a reverse phase column. The experimental conditions (enzyme/substrate ratio, incubation time, NaCl concentration) were optimised for linearity, sensitivity and precision. The assay was adequate for the study of ACE inhibition by Captopril, used as reference, and several peptides. Captopril and the fish hydrolysate had IC₅₀ values, respectively of 0.19 ng and 43 μg with standard deviations of 0.09 ng and 5 μg. Afterwards, the determination of the Hill coefficient sustained the hypothesis that active peptides present in the fish hydrolysate were low-molecular weight molecules. This result was confirmed by the activity measurement of the fish hydrolysate fractions obtained by gel filtration.     

Non-Nernstian Planar Sensors Based on YSZ with Ta (10 at.%)-Doped Nanosized Titania as a Sensing Electrode for High-Temperature Applications

Planar sensors based on tape-cast YSZ layers with two parallel Pt (or Au) finger electrodes, one covered with Ta (10 at.%)-doped nanosized titania powders, were prepared and studied. The sensors were tested at various concentrations of NO₂, CO, and different hydrocarbons in the 450–650°C temperature range. The sensitivity to different target gases was found to be strongly dependent on the operating temperature. The replacement of Pt electrodes with Au was effective in promoting the response to propylene. Moreover, an inversion of the polarity of the electromotive force response to NO₂ gas was observed in comparison with Pt-based sensors. The sensing mechanism is discussed.     

Improved performance of a protein array using conjugated polymers as capture phase for HIV serodiagnosis

A modified recombinant protein derived from the viral capsid of the human immunodeficiency virus (HIV) was coupled to a copolymer of maleic anhydride and methyl vinyl ether (MAMVE). The conjugated copolymer was spotted versus free protein in 96‐well microplates. The conjugated copolymer largely improved detection sensitivity of anti‐P24 antibodies in infected human sera. Results obtained with immuno‐linked sorbent array (ILISA) were correlated with those generated with a standard enzyme‐linked immunosorbent assay (ELISA). Serum dilution dynamic range was varied from 1/5000 to 1/150, and inter‐well coefficient of variation was below 8%. Copyright © 2004 Society of Chemical Industry     

Estimation of the dietary intake of pesticide residues, lead, cadmium, arsenic and radionuclides in France

Estimation of the dietary exposure of French consumers to 10 pesticides (omethoate, oxydemeton, phosalon, phosphamidon, triazophos, dicofol (op'+pp'), parathion ethyl, dichlorvos, procymidon and vinchlozolin), three heavy metals (lead, cadmium and arsenic) and three radionuclides (¹³⁴caesium, ¹³⁷caesium and ¹³¹iodine) from collected duplicate portion in mass catering establishments in 1998/1999 are reported, and compared with those from previous French studies as well as those from other countries. Dietary exposure estimates appear to be reassuring, in that Estimated Daily Intake (EDI) estimates are generally low, representing at maximum only 4% of the Acceptable Daily Intake (ADI) for pesticide residues and 28% of the Provisional Tolerable Weekly Intake (PTWI) for heavy metals. Moreover, none of the three radionuclides has been found in duplicate meals. When comparisons are possible, estimated dietary exposures for heavy metals are lower than those from previous French studies and similar or above those from other countries.     

Asymmetric Bromine–Lithium Exchange: Application toward the Synthesis of New Biaryl‐Diphosphine Ligands

The desymmetrization of the prochiral tetrabromobiphenyl via asymmetric bromine–lithium exchange as a key step of synthesis of novel biphenyl‐diphosphine ligands is reported. This new approach allows an easy access to twelve new enantiomerically pure atropisomeric ligands in one‐ to three‐step reactions in good to excellent yields.