Cristallogenese du 4-dimethylamino β-nitrostyrene

Single crystals of 4-dimethylamino β-nitrostyrene (DMNS) were grown from solution by a falling temperature technique. Growth conditions are given. The quality of crystals obtained was studied by X-ray diffraction methods.

$\text{DMNS : orthorhombic - class mmm - space group : Pcab}\text{a : b : c = 7,3 : 10,15 : 25,10}\text{A}\text{?}\text{Z=8}$

     

Synthesis in vitro of intrinsic membrane proteins by free, membrane-bound, and Golgi apparatus-associated polyribosomes from rat liver

A fraction of intrinsic membrane proteins was prepared from the major membranous cell components of rat liver by extraction of the membranes with KCl and deoxycholate. Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed that the compositions of the intrinsic protein fractions from rough and endoplasmic reticulum, smooth endoplasmic reticulum. Golgi apparatus, plasma membrane, and nuclear envelope were similar to each other but distinct from that of mitochondria. Among endomembranes, differences were in the ratios of protein constituents plus a few protein bands of Golgi apparatus and plasma membranes not found in endoplasmic reticulum or nuclear envelope. The abilities of total rough endoplasmic reticulum, polysomes released from rough endoplasmic reticulum, and free polysomes to incorporate amino acids into the intrinsic protein fraction were tested in vitro. Polysomes bound to endoplasmic reticulum has the greatest capacity to synthesize proteins of this fraction as shown by co-purification of radioactive products and by immunoprecipitation. Although the majority of the radioactive products synthesized by bound polysomes were distinct from those synthesized by free polysomes, certain radioactive products synthesized by free polysomes also co-purified with intrinsic membrane proteins. The results show no absolute segregation between free and bound polysomes in the synthesis of intrinsic membrane proteins. However, the majority of these proteins appear to be synthesized by polysomes bound to the endoplasmic reticulum. Several intrinsic proteins found in plasma membranes do not appear in rough endoplasmic reticulum. To determine where these proteins were synthesized, the ability of other endomembrane components to support in vitro incorporation of [14C]leucine into protein was examined. In contrast to plasma membranes, isolated Golgi apparatus fractions did incorporate [14C]leucine to an extent greater than could be explained by contamination with rough endoplasmic reticulum. Golgi apparatus in situ and isolated from rat liver have polyribosomes associated with a zone of cytoplasm at the Golgi apparatus periphery occupied by tubules and vesicles. The polysomes are not directly attached to membranes as with rough endoplasmic reticulum and may represent a special class of "Golgi apparatus-associated" polysomes. The polysomes, when associated with Golgi apparatus membranes, incorporated amino acids in vitro. The products synthesized in vitro were analyzed by treatment with KCl and deoxycholate and separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Certain proteins synthesized by the Golgi apparatus-associated polysomes remained insoluble after the treatment with KCl and deoxycholate. The proteins synthesized by the Golgi apparatus fraction had mobilities similar to proteins in plasma membranes which were absent from endoplasmic reticulum, and which were relatively minor components of Golgi apparatus...     

Ultrastructural and biochemical changes of hepatocytes during ether and fluothane anesthesia under experimental conditions

A study was made of a possibility of using Soviet made membranes "Vladipor" with a pore diameter of 16--17 nm for the purpose of concentration and purification of antigenic extracts from stab cultures of S. typhi obtained by the action of typsin, hydrogen peroxide and detergents. Preparations, complete by antigenic structure, were obtained by ultrafiltration, with a good yield. The maximal rate of ultrafiltration was noted in case of "peroxide" antigenic preparations. The use of diafiltration provided a significant reduction of the ash content in the end products.     

Complete structure of glycopeptides isolated from IgG immunoglobulins of cow colostrum

Bovine immunoglobulins (IgG1 type) have been isolated from colostral whey. Hydrolysis by pronase, trypsin and (or) chymotrypsin yield several glycopeptides structural studies of which lead to the following results. 1. IgG1 colostral immunoglobulins possess two glycan moieties which are linked to the peptidic chain by an N-(beta-aspartyl)-N-acetylglucosaminylamine bound. 2. The peptidic sequence around the linkage region has been determined by classical methods and is as follows: Thr-Lys-Pro-Arg-Glu-Glu-Gln-Phe-Asn(Glycan)-Ser-Thr-Tyr-Arg. 3. The following procedures: partial acidic hydrolysis, periodic oxidation, hydrazinolysis-nitrous deamination, methylation and use of specific glycosidases allowed us to determine the structure of the glycan moieties which fit with the general following scheme: (see article) Thus they could be related to the general glycan structure so-called of "N-acetyllactosamine type" because they possess the pentasaccharidic core common to numerous glycoproteins Man alpha 1 leads to [Man alpha 1 leads to 6] Man beta 1 leads to 4 GlcNAc beta 1 leads to 4 GlcNAc beta 1 leads to Asn on which are conjugated 2 N-acetyllactosamine residues. Besides they present a microheterogeneity which is due to the varying number of additional N-acetylneuraminic acid and fucose residues. 4. These structures are compared to various immunoglobulin structures proposed by others: bovine serum IgG and human serum IgG, IgE and IgA.     

Gammagraphy of the carotid glomus

Using the colorant proteic complex labell with Tc-99 m. we visualize--by the first time--the carotideal glomus in the human in 6 volunteers and one patient with tumor. The results are very encorageous: the method was simple and safe (one single dose endovenously) and hardless (no radiotoxicity presents in 3 months of clinical and laboratory controls) and there is a good visualization by scan of carotideal bodies "in vivo", in human being. We think this new method and labell compound could be useful in research and medical diagnoses.     

Substrate temperature and water vapour effects on structural and mechanical properties of TiO x N y coatings

Dc reactive sputtering was successfully implemented to deposit titanium oxynitride thin films using a titanium metallic target, argon, nitrogen and water vapour as reactive gases. The nitrogen partial pressure was kept constant during every deposition whereas that of the water vapour was systematically changed from 0 to 0.1 Pa. The study aims at comparing the structural and mechanical properties of the coatings deposited at room temperature (293 K) and at 673 K. Surface morphology of the film was examined by atomic force microscopy and showed different aspects according to the growth temperature. Topography mainly depends on the amount of water vapour introduced during the deposition process. Some significant changes of the crystallographic structure, due to the high substrate temperature were correlated with the evolution of the surface aspect and roughness parameters. Determination of the phase occurrence by X-ray diffraction was also carried out and appeared to be a significant parameter in understanding the evolution of mechanical properties like nanohardness (H _n) and Young’s modulus (E). H _n and E values obtained by nanoindentation ranged from 16.5 to 7 GPa and from 240 to 100 GPa, respectively. For both temperatures, mechanical properties of titanium oxynitride thin films were notably reduced as a function of the water vapour supply, especially for partial pressures higher than 4 × 10⁻² Pa. These mechanical behaviours were correlated and discussed with the phase occurrence and the amorphous structure of titanium oxynitride thin films.     

Synthesis and characterization of coprecipitation-derived ferrimagnetic glass-ceramic

Ferrimagnetic glass-ceramics could be used for magnetic induction hyperthermia. This technique is utilised for the destruction of solid neoplastic diseases by application of an alternating magnetic field. Biocompatible ferrimagnetic materials could be easily incorporated into a tumour and could generate heat mainly by hysteresis loss. A ferrimagnetic glass-ceramic in the system SiO₂–Na₂O–CaO–P₂O₅–FeO–Fe₂O₃ has been prepared by melting of the coprecipitation-derived raw materials. This glass-ceramic contains a unique crystalline phase, magnetite, embedded in an amorphous matrix. Magnetite crystals precipitate during cooling from melting temperature. This glass-ceramic would no longer require any nucleation and growth thermal treatment, since the maximal quantity of magnetite crystals was produced during cooling. The average unit-cell parameter, crystallite size of magnetite, and the quantitative ratio of the crystallographic phases in the glass-ceramic samples were evaluated using two different methods. Similar results were obtained with both methods. The magnetite crystals are about 50 nm in dimensions. The samples contain 45 wt% of magnetite, homogeneously distributed in the amorphous residual matrix. The as prepared glass-ceramic has a saturation magnetisation of 34 A·m²/kg and a coercive force of 6.7 kA/m. The estimated magnetic loss/cycle under the magnetic field up to 796 kA/m is around 1.45 mJ/g. The specific power loss of this glass-ceramic under a magnetic field of 40 kA/m and a frequency of 440 kHz is 25 W/g. This material showed a bioactive behaviour, as after 2 weeks of soaking in a simulated body fluid the formation of a hydroxylapatite layer on their surface was observed. This feature makes it also suitable for bone cancer.     

An experimental study for the effect of different clearances on burr, smooth-sheared and blanking force on aluminium sheet metal

In this study, an experimental study was carried out to examine the effect of different clearances on smooth-sheared depth, burr height and blanking force. Aluminium sheet metals with 0.8, 1, and 1.5 mm thicknesses were used in the experiments. These experiments were carried out in circular blanking dies to 6, 8, 10, and 12 mm diameters. Six different clearances (0.009, 0.064, 0.12, 0.175, 0.231 and 0.287 mm) were used for every material and diameter. The results of the experiment show that burr, smooth-sheared and punch force is strongly related to the clearance value. The results are in agreement with the results of previous theoretical and experimental work in the literature.     

High conductivity and transparent ZnO:Al films prepared at low temperature by DC and MF magnetron sputtering

Aluminum-doped zinc oxide thin films have been deposited by DC and MF magnetron sputtering from a ceramic oxide target in argon atmosphere without direct heating of the substrates. The samples were prepared at different predetermined conditions of input power or discharge voltage and the influence upon electronic, optical, and microstructural properties has been investigated. The as-deposited layers show low resistivity, such as 9 × 10^− 4 Ω cm minimum for DC excitation and 1.2 × 10^− 3 Ω cm for MF mode, with growth rates up to 130 nm/min, and resulting substrate temperatures always below 200 °C. Low resistivity of the films is combined with high transmission, 85-90% in the visible wavelength range (400-800 nm). A strong (002) texture perpendicular to the substrate has been found, with lower strain for DC than for MF sputtering.     

IDR/UPM facilities for liquid bridge experimentation on Earth under microgravity conditions

Besides space laboratories for in-orbit experimentation, Earth based facilities for laboratory experimentation are of paramount importance for the enhancement on liquid bridge knowledge. In spite of the constraints imposed by simulated microgravity (which force to work either with very small size liquid bridges or by using the Plateau tank technique, amongst other techniques), the availability and accessibility of Earth facilities can circumvent in many cases the drawbacks associated with simulated microgravity conditions. To support theoretical and in orbit experimental studies on liquid bridges under reduced gravity conditions, several ground facilities were developed at IDR. In the following these ground facilities are briefly described, and main results obtained by using them are cited.