Mechanics and physics of a glass/particles photonic sponge.

A glass containing mechanoluminescent crystalline particles behaves as a photonic sponge: that is to say it fills up with trapped electrons when exposed to UV light, and it emits light when submitted to a mechanical loading, similar to a sponge soaked with water that is wringed under mechanical action! A major finding of the present study is that the elasto-mechanoluminescence effect showing up on unloading is governed by the deviatoric part of the applied stress (no effect under hydrostatic pressure). Furthermore, the structural source for this phenomenon was elucidated by a detailed density functional theory analysis of the e- energetics at the possible oxygen vacancy sites within the crystalline phase. Both the e- trapping and detrapping processes under load could be explained. An analogy with hydraulic circuits and the rheology of viscoelastic media was successfully introduced to pave the way to a constitutive law for the mechano-optical coupling phenomenon.

First Mariner Mos1 transposase inhibitors.

We described chemical inhibitors of Mos1 transposition. Some were already known to affect a related prokaryotic transposase (Tn5) or HIV-1 integrase, whereas the other were new compounds in this field. The new compounds were all organized around a bis-(heteroaryl)maleimides scaffold. Their mechanism of action depended on the chemical substitutions on the scaffold. The cross-activity, between HIV-1 integrase and Mos1 transposase, of the new group of inhibitors showed that Mos1 transposase could constitute an excellent surrogate HIV-1 inhibitor screen.

Rotational excitation of sulfur monoxide by collisions with helium at low temperature.

We present two new two-dimensional potential-energy surfaces for the SO-He system calculated at SO r distance frozen at its experimental minimum-energy distance. Both are obtained at the RCCSD(T) level using two different basis sets (AVTZ and AVQZ) for the three atoms. Bond functions are placed at mid-distance between the SO center of mass and He for a better description of the van der Waals well. Close-coupling calculations of the collisional excitation cross sections of the fine-structure levels of SO by He are calculated at low energies. The exact level splitting is taken into account. It is found that the results obtained from the two surfaces are very similar, except for some small differences observed in the region of resonances at low energies. The propensity rules between fine-structure levels are studied, it is shown that F-conserving cross sections are much larger for high-N rotational levels than cross sections between F-changing levels, as expected from theoretical considerations. The use of infinite order sudden recoupling techniques from spin-free cross sections is investigated. Excitation rate coefficients among fine-structure levels are calculated at low temperatures.

Selective hyperfine excitation of N2H+ by He: potential energy surface, cross sections, and propensity rules.

We present potential energy surfaces for the He-N2H+ system adiabatically corrected for the zero-point motion along the intermolecular stretching vibrations v1 = 0 and v1 = 1. The potentials are extended to shorter He-N2H+ separations which makes them useful for scattering calculations. Close coupling calculations of the spinless S matrices for the rotational excitation of N2H+ by He are presented, and recoupling techniques to obtain collisional excitation cross sections between the N2H+ hyperfine levels are used. The propensity rules between hyperfine levels are investigated for the case where two nuclear spins are involved. It is found that the only well defined propensity rule is DeltaF = DeltaF1 = Deltaj and that calculations are required in order to obtain the relative intensities of the two-spin hyperfine cross sections.

Stability of brain natriuretic peptide (BNP) in human whole blood and plasma.

Brain natriuretic peptide is proposed as a biochemical marker which could provide a useful screening test to select patients for further cardiac investigations in heart failure. The applicability of such a biochemical test in clinics, hospital wards, and clinical laboratories is dependent on its ease of use and on the complexity of sample handling. The present study was undertaken to evaluate the stability of brain natriuretic peptide under a number of different handling conditions (sample collection, storage temperatures, freezing temperatures) assayed with a commercially available kit. The results clearly demonstrate that brain natriuretic peptide is stable at room temperature for 24 hours, or in up to 30 degrees C for 12 hours in the presence and absence of aprotinin, on the condition that brain natriuretic peptide is assayed within one month (frozen at -20 degrees C) after blood collection. The presence of aprotinin prevents brain natriuretic peptide degradation in samples preserved for more than 1 month at -20 degrees C before assay.

Miocardiopatía hipertrófica y doble episodio de muerte súbita recuperada: primer cardiovertor desfibrilador automático implantable colocado en Chile / Hypertrophic cardiomyopathy and double episodes of recupered sudden death: first implantable defibrillator cardiovertor installed in Chile

We report a 29 years old male with a non obstructive hypertrophic cardiomyopathy that survived two episodies of cardiac arrest and with a familiar history of the disease and sudden death. He had an implant of an automatic implantable cardioverter defibrillator by a left anterior thoracotomy with intraoperative electrophysiology. The postoperative outcome was uneventful. After one year of follow up, the patient is in good functional capacity and the implanted device has not performed defibrillations

Estado actual de los marcapasos implantables / Permanent pacemakers: state of the art

En los últimos años se ha observado un progreso importante en la tecnología de los marcapasos implantables, que ha mejorado su rendimiento y ampliado sus indicaciones. En este artículo se revisan las características técnicas de los distintos tipos de marcapaso y la nomenclatura utilizada para su identificación. Las indicaciones establecidas, las controvertidas y aquellas situaciones en que no existe indicación para implantar marcapaso, son analizados en función de los diferentes sustratos clínicos y electrofisiológicos

Evolución alejada del reemplazo valvular aórtico con prótesis mecánica: experiencia con prótesis de Starr-Edwards (1965-1974) y Bjork Shiley (1973-1981) / Results of isolated aortic valve replacement using either Starr-Edwards or Bjork-Shilley prosthesis

We compared the short and long term results of isolated aortic valve replacement in 98 patients receiving a Starr-Edwards (SE) prosthesis from 1965 to 1974 and 80 pts receiving a Bjork-Shiley (BS) prosthesis from 1973 to 1981 at our institution. Operative mortality was 20% (SE) and 6% (BS). Follow up information was obtained in 88% (SE) and 96% (BS) of pts discharged alive. The mean period of follow up was 8.2 and 6.7 years respectively. the 5 and 10 year acturial survival rates were 72% and 61% (SE) vs 89% and 83% (BS). Complications per 100 pt-years among pts with SE and those with BS were: systemic emboli 2.8 vs 0.6, major hemorrhagic events 1.25 vs 1.36, perivalvular leak 1.6 vs 1.15, endocarditis 0.31 vs 0.39, prosthetic thrombosis 0 vs 0.58 and ball variance 0.47 vs 0m respectively. Some of these differences may reflect shortcomings of the initial surgical experience during the period in which the SE prothesis was used, rather than different performance of both valves

Tratamiento quirúrgico del síndrome de Wolff-Parkinson-White / Surgical treatment of Wolff-Parkinson-White syndrome

La sección quirúrgica de los haces paraespecíficos ha demostrado ser un tratamiento eficaz para las taquicardias del síndrome de Wolff-Parkinson-White. Comunicamos nuestra experiencia con el tratamiento quirúrgico de 9 pacientes, 7 mujeres y 2 hombres, con edad promedio de 30 años. Siete pacientes tuvieron haces laterales izquierdos, 2 posteroseptales y 1 anteroseptal (1 pt con 2 haces) diagnosticados mediante estudio electrofisiológico preoperatório. La intervención se realizó con circulación extracorpórea en normotermia para los haces derechos y con hipotemia sistémica y cardioplejía en los haces izquierdos. El mapeo intraoperatorio permitió la exacta ubicación de los haces responsables de la preexitación. No hubo mortalidad ni morbilidad perioperatoria. En el 100% de los pacientes se observó eliminación de la preexitación en el estudio electrofisiológico intra y postoperatorio antes del alta. Todos los pacientes mantuvieron ritmo sinusal. En el seguimiento alejado (promedio 7 meses), todos los pacientes están en buenas condiciones, sin medicamentos antiarrítmicos y libres de nuevas crisis de taquicardia, excepto 1 pt en quien reapareció la preexitación. Concluimos que el tratamiento quirúrgico tiene un riesgo bajo y éxito del 90% en la sección definitiva del haz paraespecífico. Postulamos que la cirugía constituye un excelente alternativa de tratamiento para el síndrome de Wolff-Parkinson-White

Reemplazo de la aorta ascendente y válvula aórtica con reimplante de las arterias coronarias / Replacement of the ascending aorta and aortic valve with reimplantation of the coronary arteries

La reparación paliativa de los aneurismas de la aorta ascendente tiene una recidiva alta por tratarse de una patología degenerativa que compromete la aorta desde el anillo valvular. Actualmente se prefiere el tratamiento definitivo que consiste en el reemplazo de la aorta ascendente junto con la válvula aórtica. Entre marzo de 1978 y octubre de 1983 hemos intervenido 8 pacientes con esta patología. Cinco casos presentaban disección de la aorta de tipo proximal y 2 se operaron en etapa aguda. La indicación operatória fue insuficiencia aórtica grave en 6 pacientes y disección aguda en los 2 restantes. La reparación del aneurisma se realizó con prótesis de dacrón que tiene incorporada una válvula de Bejork-Shiley sobre la cual se reimplantaron los ostia coronarios. El estudio histológico de la aorta demostró necrosis quística de la túnica media en todos los casos. Dos pacientes fallecieron por complicaciones quirúrgicas y los 6 restantes fueron dados de alta bien. El control alejado (x = 21,6 meses) reveló que 5 pacientes están asintomáticos y sin recidiva, 1 falleció a los 15 meses. La técnica de esta grave patología con buenos resultados alejados y sin recidivas

[Automation of chemical analysis in enology]. / L'Automatisation de l'analyse chimique en oenologie.

Automatic dosages took place a short time ago in oenology laboratories. First researchs about automation of usual manual analysis have been completed by I.N.R.A. Station of Dijon during 1969--1972 years. Then, other researchs were made and in 1974 the first automatic analyser appeared in application laboratories. In all cases continuous flow method was used. First dosages which has been carried out are volatic acidity, residual sugars, total SO2. The rate of work is 30 samples an hour. Then, an original way for free SO2 was suggested. At present, about a dozen of laboratories in France use these dosages. The ethanol dosage automation, very important in oenology, is very difficult to carry out. A new method using a thermometric analyzer is tested. Research about many dosages as tartaric, malic, lactic acids, glucose, fructose, glycérol, have been performed especially by I.N.R.A. Station in Narbonne. But these dosages are not current and at present no laboratory apply them. Now, equipments price and redemption, change of tradionnal dosages for automatical methods and the level of knowledge required for operators are well known. The reproducibility and the accuracy of the continuous flow automatic dosages allow, for enough important laboratories, to make an increasing number of analysis necessary for wine quality control.

[Trehalose, the principle disaccharide of wine]. / Le tréhalose, principal diholoside des vins

By gas chromatography of trimethylsilylated derivatives of sugars, trehalose has been shown to be the main disaccharide in wines; its amount can reach 600 mg/l. Other disaccharides identified (sucrose, isomaltose, lactose and turanose) are present in small amounts, seldom above 50 mg/l, sometimes below 5 mg/l. Traces of melibiose and gentiobiose are possible. Conditions of trehalose formation by yeast during fermentation are described. Also technological applications of these results are discussed.

[Study of the transferable factors of antibiotic resistance in the enterobacteria isolated at the Regional Hospital Center of Nantes]. / Etude des caractères transférables de la résistance aux antibiotiques chez les entérobactéries isolées au Centre Hospitalier Régional de Nantes

Characteristics of transferable resistance of 72 entero-bacteriaceae resistant to one more antibiotic, isolated from February to September 1972, showed that this was common. Multi-resistant strains permit one to obtain transfer of various characteristics either alone or together in 76 per cent of cases, whereas strains with less than three characteristics, transferred in only 9 per cent of cases. The transfers were uncommon in the case of Proteus compared with other enterobacteriaceae and, in particular, Klebsiella, Escherichia coli and Salmonella.