Search results for "SPEN"

Coupling between bulk- and surface chemistry in suspensions of charged colloids

2013

The ionic composition and pair correlations in fluid phases of realistically salt-free charged colloidal sphere suspensions are calculated in the primitive model. We obtain the number densities of all ionic species in suspension, including low-molecular weight microions, and colloidal macroions with acidic surface groups, from a self-consistent solution of a coupled physicochemical set of nonlinear algebraic equations and non-mean-field liquid integral equations. Here, we study suspensions of colloidal spheres with sulfonate or silanol surface groups, suspended in demineralized water that is saturated with carbon dioxide under standard atmosphere. The only input required for our theoretical…

Molecular mechanisms of endomembrane trafficking in plants

2021

Abstract Endomembrane trafficking is essential for all eukaryotic cells. The best-characterized membrane trafficking organelles include the endoplasmic reticulum (ER), Golgi apparatus, early and recycling endosomes, multivesicular body, or late endosome, lysosome/vacuole, and plasma membrane. Although historically plants have given rise to cell biology, our understanding of membrane trafficking has mainly been shaped by the much more studied mammalian and yeast models. Whereas organelles and major protein families that regulate endomembrane trafficking are largely conserved across all eukaryotes, exciting variations are emerging from advances in plant cell biology research. In this review, …

Detection of an O-methyltransferase synthesising acetosyringone in methyl jasmonate-treated tobacco cell-suspensions cultures.

2013

Acetosyringone (3',5'-dimethoxy-4'-hydroxyacetophenone) is a well-known and very effective inducer of the virulence genes of Agrobacterium tumefaciens but the precise pathway of its biosynthesis in plants is still unknown. We have used two tobacco cell lines, cultured in suspension and exhibiting different patterns of accumulation of acetosyringone in their culture medium upon treatment with methyl jasmonate, to study different steps of acetosyringone biosynthesis. In the two cell lines studied, treatment with 100 mu M methyl jasmonate triggered a rapid and transient increase in acetovanillone synthase activity followed by a progressive increase in S-adenosyl-L-methionine: 5-hydroxyacetovan…

A novel technique for intraduodenal administration of drug suspensions/solutions with concurrent pH monitoring applied to ibuprofen formulations

2019

Characterization of dissolution of solid suspended drug particles in vivo is important for developing biopredictive in vitro tests. Therefore, methods to gain deeper insights into particle dissolution in vivo are needed. The soft Bioperm intubation method, a well established tool for investigation of permeability, absorption, metabolism, and drug interactions at predefined locations in the gastroinstinal tract, was modified. The novel intubation method involved pump-controlled infusion of pharmaceutical suspensions as well as simultaneous pH monitoring. This technique was used in a proof of concept study in healthy humans. Plasma sampling and non-compartmental analysis allowed comparison of…

Soleus aponeurosis strain distribution following chronic unloading in humans: an in vivo MR phase-contrast study.

2006

The in vivo strain properties of human skeletal muscle-tendon complexes are poorly understood, particularly following chronic periods of reduced load bearing. We studied eight healthy volunteers who underwent 4 wk of unilateral lower limb suspension (ULLS) to induce chronic unloading. Before and after the ULLS, maximum isometric ankle plantar flexion torque was determined by using a magnetic resonance (MR)-compatible dynamometry. Volumes of the triceps surae muscles and strain distribution of the soleus aponeurosis and the Achilles tendon at a constant submaximal plantar flexion (20% pre-maximal voluntary contraction) were measured by using MRI and velocity-encoded, phase-contrast MRI techn…

Anatomic Changes After Hyoid Suspension for Obstructive Sleep Apnea: An MRI Study

2005

Objective To assess the effects of isolated hyoid suspension on subjective and objective parameters of obstructive sleep apnea and to evaluate changes in upper airway anatomy with the help of standardized magnetic resonance imaging. Study design and setting Fifteen patients received isolated hyoid suspension. Changes in respiratory disturbance index were assessed with polysomnography, and anatomical changes with standardized magnetic resonance imaging. Snoring, daytime sleepiness, and functional parameters were assessed with questionnaires. Lateral x-ray cephalometry was performed preoperatively. Results Mean respiratory disturbance index was reduced from 35.2 ± 19.1 to 27.4 ± 26.2. Forty p…

Effect of biomass features on oxygen transfer in conventional activated sludge and membrane bioreactor systems

2019

Abstract The aim of the present study was to compare the oxygen transfer efficiency in a conventional activated sludge and a membrane bioreactor system. The oxygen transfer was evaluated by means of the oxygen transfer coefficient and α-factor calculation, under different total suspended solids concentration, extracellular polymeric substances, sludge apparent viscosity and size of the flocs. The oxygen transfer coefficient and α-factor showed an exponential decreasing trend with total suspended solid, with a stronger oxygen transfer coefficient dependence in the conventional activated sludge compared to the membrane bioreactor. It was noted that the oxygen transfer coefficient in the conve…

Is Active Moss Biomonitoring Comparable to Air Filter Standard Sampling?

2022

Recently, significant attention has been paid to air quality awareness and its impact on human health, especially in urban agglomerations. Many types of dust samplers for air quality monitoring are used by governmental environmental monitoring agencies. However, these techniques are associated with high costs; as a consequence, biological methods such as active moss biomonitoring are being developed. The main disadvantages of such techniques are the lack of standardization of the preparation procedures and the lack of reliable comparisons of results with data from instrumental analyses. Our study aimed to compare the results obtained from active biomonitoring with the use of three moss spec…

MISURA DELLA CONCENTRAZIONE DI SOLIDI PARTICELLARI IN SISTEMI SOLIDO-LIQUIDO AGITATI MEDIANTE LASER PULSATO E ANALISI DI IMMAGINI

2008

Home-prepared anatase, rutile, and brookite TiO2 for selective photocatalytic oxidation of 4-methoxybenzyl alcohol in water: reactivity and ATR-FTIR …

2009

5th European Meeting on Solar Chemistry and Photocatalysis -- OCT 04-08, 2008 -- Palermo, ITALY