Changes in the permeability to gas of calcareous stone core samples exposed to salt spray

This paper describes a method of measuring the permeability of stone samples to nitrogen, applicable for studying the internal micro-structural transformations that occur in building stones when exposed to salt spray. In this method the gas enters through a previously drilled hole along the axis of a cylindrical stone sample and crosses the lateral surface by radial flux. For artificial weathering tests that affect the sample surface, this method is more suitable than the Cembureau method and gives similar permeability values. Furthermore, by changing the diameter of the hole drilled, it is possible to analyse the variations of the transfer property from the interior to the exposed surface and to study the localised effects of marine salts. The method was used during salt spray accelerated deterioration tests to asses the degree of saturation of the pores in calcareous stones traditionally used in construction in France.

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Résumé Nous décrivons dans cet article une méthode de mesure de perméabilité à l'azote mise au point pour étudier les modifications micro-structurales internes qui se manifestent dans des pierres de construction sous l'effet d'une exposition au brouillard salin. Le gaz est introduit par un trou préalablement usiné dans l'axe d'un échantillon cylindrique de pierre et traverse la surface latérale suivant un flux radial. Pour des tests de vieillissement affectant les surfaces, cet essai est plus adapté que la méthode Cembureau et fournit une mesure de la perméabilité tout à fait comparable. De plus, en jouant sur le diamètre de la perforation, on peut analyser l'évolution de la perméabilité du matériau en profondeur et au voisinage de la surface exposée et étudier les effets localisés des sels marins. La méthode de mesure a été utilisée au cours de simulations accélérées d'altération par brouillard salin, afin d'évaleur le degré de saturation de pores dans le cas de pierres calcaires traditionnellement utilisées dans la construction en France.

     

Optical Frequency Metrology of an Iodine-Stabilized He-Ne Laser Using the Frequency Comb of a Quantum-Interference-Stabilized Mode-Locked Laser

We perform optical frequency metrology of an iodine-stabilized He-Ne laser using a mode-locked Ti:sapphire laser frequency comb that is stabilized using quantum interference of photocurrents in a semiconductor. Using this technique, we demonstrate carrier-envelope offset frequency fluctuations of less than 5 mHz using a 1 s gate time. With the resulting stable frequency comb, we measure the optical frequency of the iodine transition [¹²⁷I₂ R(127) 11-5 i component] to be 473 612 214 712.96 ± 0.66 kHz, well within the uncertainty of the CIPM recommended value. The stability of the quantum interference technique is high enough such that it does not limit the measurements.     

Mumps orchitis; review of 8 cases]

The occurrence of secondary hypogonadism is a common finding in males who seek help with erectile dysfunction, although the relationship to diminished testosterone is unclear. Two possibilities exist regarding both the genesis and maintenance of the hypogonadotropic hypogonadal state. First, a defect in hypothalamic function, resulting in downregulation as well as in alterations of anterior pituitary function; second, estradiol inhibition of gonadotropin release, both of which result in decreased testosterone production. As testosterone levels decrease and estradiol levels increase, the ratio of free testosterone to estradiol reaches a critical point and the estrogenic gonadotropin suppressive effects predominate. This ratio may signal the biological point of no return and could become one of the criteria for defining the separation of the transitional hypogonadal state from the final 'end stage' hypogonadotropic hypogonadal state. As the aging process continues, there is a relative accumulation of fatty tissue, and aromatization accelerates the conversion of testosterone to estradiol. This additional secondary estradiol inhibition results in the maintenance of the testosterone deficient state, and the aging process continues uncontested.     

Bone marrow biopsy in the diagnosis of fever of unknown origin in patients with acquired immunodeficiency syndrome

BACKGROUND: Fever is commonly observed in patients with human immunodeficiency virus (HIV) disease and frequently eludes diagnosis. The role of bone marrow biopsy in the diagnosis of fever of unknown origin in patients infected with HIV remains controversial. PATIENTS AND METHODS: One hundred twenty-three consecutive patients with 137 episodes of fever lasting 10 or more days without diagnosis after 1 week of hospitalization were evaluated by bone marrow biopsy. RESULTS: Overall, a specific diagnosis was achieved in 52 episodes by means of culture and histopathological examination (diagnostic yield, 37.9%). Three types of disease were found: mycobacterial infections (n = 36, 69% of documented episodes), including 18 patients with disseminated tuberculosis and 14 with Mycobacterium avium-intracellulare complex infections; non-Hodgkin lymphomas (n = 12, 23%); and visceral leishmaniasis (n = 4, 8%). Although bone marrow cultures were more sensitive than microscopic examination with special stains for the diagnosis of mycobacterial infections, the pathological examination of bone marrow led to a more rapid diagnosis of disease. In addition, the histopathological examination of bone marrow alone led to the diagnosis of a specific condition in 43 episodes (31.3% of all episodes). CONCLUSIONS: Bone marrow biopsy is a useful procedure for the diagnosis of fever in patients with advanced HIV disease, particularly in areas where tuberculosis and leishmaniasis are prevalent. Involvement of the marrow may be the first indication of the existence of extranodal non-Hodgkin lymphoma. For Mycobacterium avium-intracellulare complex infection, blood cultures were more sensitive than bone marrow biopsy.     

Comparative effectiveness and safety of cefdinir and amoxicillin-clavulanate in treatment of acute community-acquired bacterial sinusitis. Cefdinir Sinusitis Study Group

Cefdinir is an extended-spectrum oral cephalosporin that is active against pathogens commonly seen in acute community-acquired bacterial sinusitis (ACABS), including Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis. Two randomized, investigator-blind, multicenter trials (one in the United States and one in Europe) compared two dosage regimens of cefdinir (600 mg once a day for 10 days and 300 mg twice a day for 10 days) to amoxicillin-clavulanate (A-C) (500 mg three times a day for 10 days) for adult and adolescent patients with ACABS. Twelve hundred twenty-nine patients entered the U.S. study, 698 with antral puncture; 569 patients entered the European study, all with antral puncture. Clinical response (cure or improvement) was determined 7 to 14 days and 3 to 5 weeks posttherapy. Microbiologic eradication rates were determined 10 to 30 days posttherapy in a subset of patients who underwent pre- and posttherapy sinus aspirate culture. Rates of adverse events and treatment discontinuations due to adverse events were examined. Cefdinir, given once or twice daily, was as effective clinically (approximately 90% cure rate) as amoxicillin-clavulanate given three times daily in the treatment of ACABS. Microbiologic eradication rates were also similar in the three groups. The major side effect was mild diarrhea, occurring in approximately 20% of each group. Cefdinir caused fewer adverse events requiring treatment discontinuation.     

A quasi-static magnetic hysteresis loop measurement system with drift correction

A method to overcome the residual drift problem inherent to M-H quasi-static hysteresis loop measurements is described. The solution is based on the magnetic hysteresis symmetry properties and was implemented in a computer-controlled inductive measurement system with frequency range 3-100 MHz for straight and circular samples particularly of soft amorphous and nanocrystalline alloys. Results obtained for several samples are presented showing the ability of the method to remove the residual drift.     

Snake Mating Systems, Behavior, and Evolution: The Revisionary Implications of Recent Findings.

Sexual selection and mating systems profoundly influence the behavior and psychology of animals. Using their own studies of green anacondas (Eunectes murinus) and reviewing other recent studies, the authors conclude that incomplete data derived from a few well-studied snake species have led to general acceptance of polygyny as the dominant mating system in snakes. New data on behavior, paternity, and life history in a diverse taxonomic array of snakes support the view that polyandry is not only common in snakes but may have been the ancestral mating system. This interpretation helps to explain many seemingly paradoxical behavioral differences between lizards and snakes, such as the lack of territorial systems in most snakes and their frequent female-biased sexual size dimorphism. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Phospholipase D activity is required for suppression of yeast phosphatidylinositol transfer protein defects

Yeast phosphatidylinositol transfer protein (Sec14p) function is essential for production of Golgi-derived secretory vesicles, and this requirement is bypassed by mutations in at least seven genes. Analyses of such 'bypass Sec14p' mutants suggest that Sec14p acts to maintain an essential Golgi membrane diacylglycerol (DAG) pool that somehow acts to promote Golgi secretory function. SPO14 encodes the sole yeast phosphatidylinositol-4,5-bisphosphate-activated phospholipase D (PLD). PLD function, while essential for meiosis, is dispensable for vegetative growth. Herein, we report specific physiological circumstances under which an unanticipated requirement for PLD activity in yeast vegetative Golgi secretory function is revealed. This PLD involvement is essential in 'bypass Sec14p' mutants where normally Sec14p-dependent Golgi secretory reactions are occurring in a Sec14p-independent manner. PLD catalytic activity is necessary but not sufficient for 'bypass Sec14p', and yeast operating under 'bypass Sec14p' conditions are ethanol-sensitive. These data suggest that PLD supports 'bypass Sec14p' by generating a phosphatidic acid pool that is somehow utilized in supporting yeast Golgi secretory function.     

Report on the therapeutic use of rimantadine and amantadine]

A discussion is carried out about the experiences with the application of rimantadine and amantadine to patients with influenza. The basic general results consisted in the fact that 2 of the 74 patients treated had a high cure percent (> 68.0%) within the first 72 hours after using the drug. No new diseased were found among the 40 contacts to whom chemoprophylaxis was applied. There were only 3.9% adverse reactions among the total number of people treated with amantadine.