1. The effect of the pH on the germicidal action of soaps has been studied. The lower members of the series were found to be most active in acid solution; the higher members, in alkaline. The point of transition varied with the test organism used. 2. This is probably due to the effect of the pH on the dissociation residue and on the solubility of the soap. The dissociation residue may affect th...

The asymmetric outer membrane of Gram-negative bacteria contains lipopolysaccharides (LPSs) which contribute significantly to the bacterium's surface properties and play a crucial role in regulating membrane permeability. We report on neutron diffraction studies performed on aligned, self-assembled bilayers of Na-, Ca-, and Mg-salt forms of LPS isolated from Pseudomonas aeruginosa PAO1. From th...

Cephalosporins have been widely used for treating diseases caused by pathogenic bacteria in human and animals. Through the tonB dependent iron transport mechanism,1>2) the use of catechol substituted /Mactams was knownto increase the drug's penetration into the bacterial cell walls. Thus, several catechol-substituted /Mactams have been synthesized and showed good antipseudomonal activities.3 ~ ...

Normal bacteria can translocate (migrate) across an intact intestinal mucosa, but the anatomical site of bacterial translocation has not been defined. Gastrointestinal (GI) cross-sections were obtained from mice monoassociated with high cecal concentrations of Escherichia coli, Proteus mirabilis, or Enterococcus faecalis. As previously reported (C. L. Wells, R. P. Jechorek, and K. J. Gillingham...

Background and Aim: Tubular penetration of root canal sealers prevents filling material displacement and overgrowth of microorganisms in dentinal tubules. The aim of this study was to compare the tubular penetration of AH26, EasySeal, and SureSeal sealers in single-rooted teeth using scanning electron microscopy (SEM). Materials and Methods: Fifty human single-rooted teeth were included in thi...

A variety of respirator filters and surgical masks were challenged with three aerosolized bacteria: Mycobacterium abscessus (M.a.) (a rod), Staphylococcus epidermidis (S.e.) (a sphere), and Bacillus subtilis (B.s.) (a rod). Tests were conducted at two flow rates (45 and 85 l./min) and two humidity levels (30 and 70%). Aerosols were measured with a total-particle, direct-reading, spectrometer an...

one of the most important parameters used for determining the performance of tunnel boring machines (tbms) is their penetration rate. the parameters affecting the penetration rate can be divided in two categories. the first category is the controllable parameters such as the tbm technical characteristics, and type and geometry of the tunnel, and the second one is the uncontrollable parameters s...

bovine oocytes matured in culture were denuded from cumulus cells with hyaluronidase and by repeat pipetting trough a fine pasture pipete and were inseminated with frozen-thawed spermatozoa in a protein-free bo medium containing 5m m-caffeine, l0 mg heparin/ml and with or without polyvinyl pyrrolidone (pvp) and different concentrations of hyaluronic acid. when oocytes were inseminated in the ab...

The move to the cloud brings a number of new security challenges, but the application remains your last line of defense. Engineers are extremely well poised to perform tasks critical for securing the application—provided that certain key obstacles are overcome. Cloud Shifts the Burden of Security to Development