Kinetic studies on the expression of alginate and extracellular proteins by Pseudomonas aeruginosa FRD1 and PAO1.

Pseudomonas aeruginosa is characterized by its capability to produce extracellular virulence proteins and to establish biofilm-based infections that do not respond easily to conventional treatments. However, the physiological conditions that decrease the fitness of such a persistent pathogen would assist the host to defend itself and reduce the infection prevalence. Therefore, developing treatments against P.

Expression of extracellular polysaccharides and proteins by clinical isolates of Pseudomonas aeruginosa in response to environmental conditions.

The opportunistic pathogen Pseudomonas aeruginosa causes chronic respiratory infections in patients with cystic fibrosis (CF). Persistence of this bacterium is attributed to its ability to form biofilms which rely on an extracellular polymeric substance matrix. Extracellular polysaccharides (EPS) and secreted proteins are key matrix components of P.

Technical note: A comparison of alkali treatment methods to improve neutral detergent fiber digestibility of corn stover.

The objective of this study was to compare neutral detergent fiber (NDF) digestibility of corn stover that had been treated by 2 alkali treatment methods. Two experiments were conducted to test a sodium hydroxide (NaOH) treatment method that uses an ethanol/water co-solvent (NaOH/ethanol-HO, United States Patent No. 20140220228) and a calcium hydroxide (CaOH) treatment method, which uses water as a solvent (CaOH/HO).

Irreversible transformations of native celluloses, upon exposure to elevated temperatures.

Current research, basic and applied, assumes that observed recalcitrance of celluloses is an inherent characteristic associated with their state of aggregation in their native state; it is thought that processes of isolation remove other components of plant cell walls leaving the celluloses unchanged, even though elevated temperatures are routinely used during isolation. Since temperature elevation is known to influence the structures of all polymers, it is important to explore its influence on the character of isolated celluloses, almost always assumed to be still in their native state. Deuterium exchange is a measure of accessibility of reactive sites in celluloses.

Haemostatic changes in the puerperium '6 weeks postpartum' (HIP Study) - implication for maternal thromboembolism.

Objective: We aim to measure the thrombotic changes during the postnatal period up to 6 weeks after delivery and assess the extent of the risk period.

Design: Prospective observational study.

Setting: Queen Elizabeth II, an acute District General Hospital, Hertfordshire.

The use of intrauterine Monsel's solution in severe hemorrhage after evacuation of retained products of conception: a case report.

This is the first reported case of the use of Monsel's solution to arrest excessive uterine bleeding after the evacuation of retained products of conception after a miscarriage. Monsel's solution impregnated into a uterine pack was used to secure hemostasis. Fertility was preserved because 7 months later the woman became pregnant and had an uncomplicated pregnancy and delivery at term.

Reduction of O2 to superoxide anion (O2.-) in water by heteropolytungstate cluster-anions.

Fundamental information concerning the mechanism of electron transfer from reduced heteropolytungstates (POM(red)) to O2, and the effect of donor-ion charge on reduction of O2 to superoxide anion (O2.-), is obtained using an isostructural series of 1e--reduced donors: alpha-X(n+)W12O40(9-n)-, X(n+) = Al3+, Si4+, P5+. For all three, a single rate expression is observed: -d[POM(red)]/dt = 2k12[POM(red)][O2], where k12 is for the rate-limiting electron transfer from POM(red) to O2.

Electron exchange between alpha-Keggin tungstoaluminates and a well-defined cluster-anion probe for studies in electron transfer.

Fully oxidized alpha-AlIIIW12O40(5-) (1ox), and one-electron-reduced alpha-AlIIIW12O40(6-) (1red), are well-behaved (stable and free of ion pairing) over a wide range of pH and ionic-strength values at room temperature in water. Having established this, 27Al NMR spectroscopy is used to measure rates of electron exchange between 1ox (27Al NMR: 72.2 ppm relative to Al(H2O)63+; nu(1/2) = 0.

The complex of xylan and iodine: the induction and detection of nanoscale order.

The complex of xylan and iodine and its formation in a solution of xylan, CaCl2, and I2+KI was investigated by UV/Vis, second-derivative UV/Vis, and Raman spectroscopy. The complex forms only at very high concentrations of CaCl2, suggesting that when the water available in the solution is not sufficient to fully hydrate the calcium cation the chelation with the hydroxyl groups of the xylan can occur. The electronic spectra indicate that iodine is present in the form of three linear polyiodides I9(3-), I11(3-), and I13(3-) structures, which the Raman spectra show to be linear aggregates of the I3- and I5- substructures.

Transcript analysis of genes encoding a family 61 endoglucanase and a putative membrane-anchored family 9 glycosyl hydrolase from Phanerochaete chrysosporium.

Phanerochaete chrysosporium cellulase genes were cloned and characterized. The cel61A product was structurally similar to fungal endoglucanases of glycoside hydrolase family 61, whereas the cel9A product revealed similarities to Thermobifida fusca Cel9A (E4), an enzyme with both endo- and exocellulase characteristics. The fungal Cel9A is apparently a membrane-bound protein, which is very unusual for microbial cellulases.

The role of solid state 13C NMR spectroscopy in studies of the nature of native celluloses.

Published spectroscopic observations pertaining to the crystal structure of native celluloses are reviewed for the purpose of defining our current level of understanding about crystalline polymorphism in these materials. Emphasis is placed on observations from solid state 13C nuclear magnetic resonance (NMR), which first led to the postulate that most native, semicrystalline celluloses are composites of two crystalline allomorphs, labeled Ialpha and Ibeta. Historical background is presented, highlighting the structural controversies which mainly arose because different native celluloses were used, each one representing a different mixture of allomorphs.

Reactive thrombocytosis after caesarean section and vaginal delivery: implications for maternal thromboembolism and its prevention.

Objective: To assess the duration and severity of reactive thrombocytosis after caesarean section and vaginal delivery.

Design: A prospective cohort study.

Setting: A large teaching hospital.

Newborn acid-base status and umbilical cord morphology.

Objective: To assess the relation between umbilical cord morphology and intrapartum fetal status and umbilical cord blood gases at birth.

Methods: In a prospective study of 134 consecutive newborns and their umbilical cords, relations were investigated between umbilical cord morphologic characteristics (umbilical cord length, number of vascular coils, coiling index, and vessel length index) and intrapartum fetal heart rate (FHR) decelerations, color of amniotic fluid, operative delivery for suspected fetal acidosis, umbilical vessel blood gases, and acid-base status.

Results: Statistically significant linear correlations were found between umbilical venous pH and the umbilical cord length (r = 0.

Modern lines of management of ectopic pregnancy.

The recent increase in the incidence of ectopic pregnancies was associated with rapid improvement in the diagnostic and therapeutic techniques. Quantitative serum B-HCG radioimmunoassay and high resolution vaginal ultrasonography have facilitated early diagnosis of ectopic pregnancy allowing a more conservative approach to patient management. Different conservative surgical and medical lines of management recently developed were associated with and increased chance of subsequent intrauterine pregnancy with no increase in the incidence of repeat ectopic pregnancy.

Production of cellulose II by Acetobacter xylinum in the presence of 2,6-dichlorobenzonitrile.

This report provides X-ray diffraction and Raman spectral evidence that, when 2,6-dichlorobenzonitrile is present in the culture medium, Acetobacter xylinum, which is a model system for investigation of the biosynthesis of native cellulose, produces cellulose II, as well as cellulose I. The significance of the observations with respect to the mechanism of biosynthesis of cellulose is discussed briefly.

Cellulose-Lignin Interactions (A Computational Study).

Within a broader program of study of the molecular structure of plant cell walls, molecular dynamics calculations were used to explore the character of the motion of lignin model compounds near a cellulose surface. Model cellulose microfibrils, which have a large number of hydroxyl groups on the surface, appear to have a net attractive interaction with the lignin models examined in this study. The lignin monomer coniferyl alcohol rapidly adsorbed onto the surface from a water layer after it was released 13 A from the surface.

Modification of crystallinity and crystalline structure of Acetobacter xylinum cellulose in the presence of water-soluble beta-1,4-linked polysaccharides: 13C-NMR evidence.

Cellulose produced by Acetobacter xylinum in medium containing 0.5% xyloglucan or glucomannan showed altered crystallinities and shifted I alpha/I beta ratios when analysed by solid-state 13C-NMR. By estimating the spectra of cellulose components in each composite, a decreased I alpha content was shown to be countered by increased I beta content in cellulose aggregated in the presence of xyloglucan, causing minimal loss of crystallinity.

Hemicelluloses as structure regulators in the aggregation of native cellulose.

The influence of hemicelluloses on the aggregation of cellulose in higher plant cell walls was modelled by adding hemicelluloses to cultures of the cellulose producer Acetobacter xylinum. Characterization of the celluloses by X-ray diffractometry showed them to be more like those that occur in higher plants; the coaggregation of the hemicelluloses suggests their occlusion within and between the crystalline domains of the celluloses. The authors propose that hemicelluloses may be primary moderators of the tertiary structure of cell wall celluloses, allowing the development of a wide range of properties.