The complete sequence of the 8.2 kb segment left of MAT on chromosome III reveals five ORFs, including a gene for a yeast ribokinase

We report here the DNA sequence of a segment of chromosome III extending over 8.2 kb. The sequence was determined using the random clone strategy followed by oligonucleotide-directed sequencing. The segment contains five long open reading frames, YCR521, 522, 523, 524 and 526, with only short distances between them. YCR523 (333 codons) encodes a ribokinase, a new function for yeast. YCR526 originates inside the MAT cassette, which is in continuity with the present segment, and extends over 358 codons outside of MAT. YCR524 (923 codons) codes for a putative membrane protein. YCR521, 522 and 524, have each been disrupted by insertion of a URA3 cassette and are non-essential genes. An active ARS element is located within YCR523 or its vicinity.     

A new route for the preparation of cyano‐containing poly(N‐isopropylacrylamide) microgel latex for specific immobilization of antibodies

A prepolymerization process was used to prepare functionalized poly(N‐isopropylacrylamide) latexes with surface cyano groups. The functionalized latexes prepared were characterized by FTIR, ¹H NMR, scanning electron microscopy and quasi‐elastic light scattering. In addition, the polymerization conversion and the water‐soluble polymer amounts were quantified. The polymerization conversions were found to be above 80% with 5–14 wt% of water soluble polymer formation. The immobilization of antibody (immunoglobulin) onto such cyano‐containing thermally sensitive particles, suggests the feasibility of specific dipole–dipole interactions between the cyano and hydroxyl functional groups from particle and antibody, respectively. Copyright © 2004 Society of Chemical Industry     

Synthesis of oligocaprolactone vinyl ether macromonomers and their use for indomethacin encapsulation in polymer nanoparticles based on polycaprolactone macromonomer–maleic anhydride–N‐vinyl pyrrolidone terpolymers

Oligocaprolactone macromonomers functionalized with vinyl ether have been synthesized by polymerization of ε‐caprolactone in the presence of hydroxy ethyl or butyl vinyl ether and characterised by NMR and Maldi time‐of‐flight mass spectroscopy. These macromonomers have been copolymerized with maleic anhydride and N‐vinyl pyrrolidone to give terpolymers, which have been used to obtain nanoparticles by the phase‐separation‐dialysis method. Previously dissolving indomethacin in the terpolymer solution allows one to encapsulate the drug inside the nanoparticles. Copyright © 2005 Society of Chemical Industry     

Determination of trimethylamine in milk using an MS based electronic Nose

A simple, rapid, reliable and highly automated analytical method has been developed to determine trimethylamine (TMA) in milk using an MS based electronic nose (SMart Nose). A set of Swedish milk samples with and without naturally occurring TMA was used to compare this new method with sensory analysis and dynamic headspace (DHS) gas chromatography with flame ionisation detection (GC-FID). The results show good agreement between these three analytical methods. A lower detection limit (0.5 mg kg^-1) and better repeatability were achieved with this new method compared to both sensory and DHS GC-FID analyses (1-2 mg kg^-1). The user-friendly multivariate analysis software provided with the SMart Nose system was used for TMA determination via a numerical PCA. Using Excel, peak intensity, correlated with TMA concentration via a second order equation, gave similar results. Thus, this is an up to date method of choice for the quantitative determination of TMA in milk. It is also able to give further qualitative information on the milk analysed using the PCA analysis supplied with this equipment.     

Development of the First Oral Bioprecursors of Bis‐alkylguanidine Antimalarial Drugs

Plasmodium falciparum is responsible of the most severe form of malaria, and new targets and novel chemotherapeutic scaffolds are needed to fight emerging multidrug‐resistant strains of this parasite. Bis‐alkylguanidines have been designed to mimic choline, resulting in the inhibition of plasmodial de novo phosphatidylcholine biosynthesis. Despite potent in vitro antiplasmodial and in vivo antimalarial activities, a major drawback of these compounds for further clinical development is their low oral bioavailability. To solve this issue, various modulations were performed on bis‐alkylguanidines. The introduction of N‐disubstituents on the guanidino motif improved both in vitro and in vivo activities. On the other hand, in vivo pharmacological evaluation in a mouse model showed that the N‐hydroxylated derivatives constitute the first oral bioprecursors in bis‐alkylguanidine series. This study paves the way for bis‐alkylguanidine‐based oral antimalarial agents targeting plasmodial phospholipid metabolism.     

Influence of built environment on pedestrian's crossing decision

The objective of this experimental study is to identify the differentiation made by pedestrians, in their crossing decision, between various urban environments, notably in terms of perception of walking pleasantness and safety. This experiment further aims to identify the environmental features that pedestrians take into account and the inferences they develop and use to explain their road crossing decision. Sets of photographs presenting five different environments (city center, inner suburbs, public housing in the outskirts, commercial zone in the outskirts and countryside) were presented to 77 participants divided up into three age groups (pre-adolescents, young and middle adults). Their decision to cross or not, their perception of pleasantness and safety, and the elements they take into account to make a decision were collected for each environment presented. The quantitative results show the pedestrians’ perceptions of the pleasantness and safety of public spaces, in terms of walking, largely vary with urban environments. Moreover, the crossing decision significantly varies according to the environment. Pedestrians were significantly more inclined to take the decision to cross in city center than in the other sites presented. The qualitative analysis of the interviews shows that the presence and function of the buildings, the quality of the sidewalks and the marked parking spaces are key factors to explain their crossing decision, by enabling them to infer the density of pedestrians and traffic and the vehicle speed.     

Material response characterization of a low-density carbon composite ablator in high-enthalpy plasma flows

Future space exploration missions beyond Earth’s orbit, such as sample returns from Mars, will use ablative materials for the thermal protection system in order to shield the spacecraft from the severe heating during reentry. In this paper, we present the results of an elaborate test campaign on a lightweight carbon composite ablator with the aim of defining a procedure for material response characterization in a 1.2-MW inductively heated Plasmatron facility, suitable to reproduce the hypersonic flight boundary layer environment. Three different test gases were used, air, nitrogen, and argon, at surface temperatures exceeding 3300 K. A comprehensive experimental setup was developed including a nonintrusive technique to measure surface recession by means of a high-speed camera. Surface degradation was strongly test gas dependent, while mass loss was mainly driven by in-depth decomposition of phenolic resin. Emission spectroscopy helped us identify C₂ as a product of dissociating hydrocarbons, as well as cyanogen, suggesting surface nitridation. Melt flow at the surface and silicon emission indicated degradation of the glass microspheres used as additional filler. In air plasma, oxidation was inferred to be the main mechanism for ablation.     

Evaluation of the performance of an absorption–demixtion heat pump for upgrading thermal waste heat

An absorption/demixtion heat pump is used to overcome the classic heat pump's performance limitation due to the high cost of the amount of energy consumed in the separation process. This heat pump concept uses a partially miscible mixture as working fluid instead a binary miscible mixture. Under low pressure the mixture is a heterogeneous solution of two non-miscible phases in thermodynamic equilibrium but at very different compositions. Then the solution spontaneously splits into two liquid phases without any energy supply. Beyond a critical pressure of dissolution the two earlier non-miscible phases become miscible and then form a homogeneous liquid phase. In these conditions, at high temperature, the more volatile phase is evaporated and its vapor absorbed in the less volatile phase in exactly the same way as in the classical heat pump. The features of this system are presented and a comparison is made against the classic absorption heat pump and the compression heat pump. The different steps of the system are represented by the conventional methods of McCabe and Thiele, and Ponchon–Savarit, to provide a good understanding. We calculated the performance of this system and compared its values against those of the absorption heat pump and the compression heat pump: the COP is respectively 2 and 100 times greater because the separation does not need costly energy. Moreover, the system presents investment cost saving because the separator is a simple decanter.     

Rayleigh-like instability in the ion-shaping of Au-Ag alloy nanoparticles embedded within a silica matrix

We have studied how spherical 23 ± 3 nm Au(45)Ag(55) nanoparticles embedded within a silica matrix transform into prolate nanorods and nanowires by irradiating them with swift heavy ions. Samples were irradiated at room temperature and normal incidence with 74 MeV Kr and 36 MeV S ions for fluences up to 1.0 × 10(15) cm(-2). We demonstrate the existence of two regimes: (i) below a critical fluence, ～ 2.0 × 10(14) cm(-2), the transformation of the spherical nanoparticle into a nanorod is an individual process, i.e. each nanoparticle transforms into a single nanorod; (ii) for larger fluences the transformation from nanorod to nanowire becomes a collective process, i.e. the break up and dissolution of unstable nanorods contribute to the growth of long nanowires. The passage from the first to the second regime can be interpreted in terms of a Rayleigh-like instability under irradiation. The latter becomes active when the diameter of the nanowire approaches its saturation width under irradiation. Furthermore, we show that the composition of the alloy is only slightly modified during the ion-shaping process. Finally, the energy and the fluence thresholds for deformation and the deformation strain-rate are estimated.