Triggered cargo release by encapsulated enzymatic catalysis in capsosomes

We report the coencapsulation of glutathione reductase and disulfide-linked polymer-oligopeptide conjugates into capsosomes, polymer carrier capsules containing liposomal subcompartments. The architecture of the capsosomes enables a temperature-triggered conversion of oxidized glutathione to its reduced sulfhydryl form by the encapsulated glutathione reductase. The reduced glutathione subsequently induces the release of the encapsulated oligopeptides from the capsosomes by reducing the disulfide linkages of the conjugates. This study highlights the potential of capsosomes to continuously generate a potent antioxidant while simultaneously releasing small molecule therapeutics.     

Predicting glass furnace output using statistical and neural computing methods

This paper describes the development of predictive models for glass production at a regional manufacturing company. The objectives of the models are to predict the actual batch tonnage produced per week from the glass furnace based on the planned production schedule. Four modelling methods were explored: (i) linear regression; (ii) nonlinear regression; (iii) artificial neural network using back-propagation; and (iv) radial basis function neural network. Using 175 cases of production schedule data and subsequent furnace output, the two neural network-based prediction models resulted in lower average absolute error and lower maximum absolute error than the linear or nonlinear regression models. Accurate neural network-based prediction models of furnace output will subsequently be used in the overall production planning system by utilizing estimates of furnace output to determine the necessary energy, raw material, repair and personnel requirements of the glass manufacturing facility.     

ESTIMATION OF THE AVERAGE ASPECT RATIO OF LAMELLAE-SHAPED PARTICLES BY LASER DIFFRACTOMETRY

Reinforcing properties for polymers and elastomers, rheological properties of high density aqueous slurries, hidding power, lubricating properties of platey particles strongly depend on their size distribution and shape factor or aspect ratio (A.R.).

Determinations of A.R. of fine particles by conventional methods are time-consuming and require sophisticated equipment. A method based upon later light diffractometry has been developed to meet control requirements in industry, the average A.R. can be determined within 5 to 10 minutes, depending upon the number of measurements made using a commercial laser granulometer.

The method relies on:

a cylindrical model (disc) of platey particles.

determinations of the projected area of particles in dilute suspensions of controlled solids concentrations.

calibration of the instrument, using isodiametric particles

simple material balance to derive the average thickness h of the platey particles from projected area measurements and volume of the solid.

A.R. is defined as d50(S)/h. where d50(S) is the mean projected area diameter and h the average thickness attributed to all particles occurring in the sample.     

Simultaneous determination of nerisopam, a novel anxiolytic agent showing polymorphic metabolism, and its N-acetyl metabolite from human plasma by a validated high performance liquid chromatographic method

OBJECTIVE: Our goal was to determine the effect of chronic and acute umbilical-placental embolization on placental hemodynamic and fetal heart rate patterns in relation to fetal oxygenation in the near-term ovine fetus. STUDY DESIGN: Daily fetal placental embolization was performed during 10 days in 9 sheep fetuses until fetal arterial oxygen content decreased by approximately 30%. Nine control fetuses received saline solution. Mean and pulsatile umbilical blood flow, perfusion pressure, placental vascular resistance, fundamental impedance, pressure pulsatility index, and umbilical artery resistance index corrected to a fetal heart rate of 160 beats/min were measured. On day 10 both groups were acutely embolized until fetal arterial pH decreased to approximately 7.00. Fetal heart rate was measured with the Sonicaid System 8000 (Oxford Sonicaid, Oxford, United Kingdom). RESULTS: Chronic fetal placental embolization was associated with a progressive reduction in umbilical blood flow (p < 0.00001) and fetal arterial oxygen content (p < 0.001) whereas fetal heart rate patterns remained unaltered. A chronic increase in umbilical artery resistance index corrected to a fetal heart rate of 160 beats/min could be entirely explained only if the changes in umbilical artery pressure pulsatility index and the fundamental impedance were taken into account, in addition to the changes observed in placental vascular resistance. During acute embolization leading to a 50% reduction in umbilical blood flow (p < 0.0002) and a three times increase in placental vascular resistance (p < 0.0001), the most consistent change in fetal heart rate patterns related to progressive metabolic acidosis was an 84% decrease in absolute acceleration frequency (p < 0.0001) whereas short-term fetal heart rate variability remained unaltered. CONCLUSION: Changes in umbilical artery resistance index induced by chronic umbilical-placental embolization resulting in fetal hypoxemia occurred before any changes in fetal heart rate patterns were detectable. A decrease in the absolute acceleration frequency was the only component of fetal heart rate patterns related to progressive metabolic acidosis in the near-term ovine fetus.     

Children's perceptions of parental work.

249 3rd and 4th graders and both of their parents were asked about the nature of the parents' work, their attitudes toward it, and a variety of other work-related questions. The children knew in general what their parents did, where, and when. They were also somewhat aware of their parents' satisfaction with their work. Mothers who were homemakers were perceived by their children to be less satisfied with their work than were mothers in the paid labor force. However, the children were equally satisfied with the work of both groups. Children were dissatisfied with their parents' work only when their mothers worked evening or night shifts. Results are discussed in terms of the role played by parental work in the process of socialization of children regarding work. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perceived control and intellectual functioning in the elderly: A 5-year longitudinal study.

We examined whether control beliefs are related to individual differences in intellectual aging by administering a battery of intellectual tests and perceived control scales to 63 elderly adults in 1981 and in 1986. Over the 5 years there were no changes in generalized control or intellectual performance, but there were changes in intellectual control beliefs. Specifically, the participants reported an increased dependence on others to carry out cognitive tasks. The cross-occasion stability correlations were relatively high, although there was some evidence for individual differences in change, especially for the control variables. Surprisingly, those with higher levels of education were more likely to show decreases in perceived intellectual control. Health was a significant antecedent of individual changes in vocabulary performance and intellectual control. The results also indicated that fluid intelligence was a significant predictor of changes in intellectual control beliefs, but control beliefs did not affect performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Polarization of the human motor cortex through the scalp

Direct currents (DC) applied directly to central nervous system structures produce substantial and long-lasting effects in animal experiments. We tested the functional effects of very weak scalp DC (< 0.5 mA, 7 s) on the human motor cortex by assessing the changes in motor potentials evoked by transcranial magnetic brain stimulation. We performed four different experiments in 15 healthy volunteers. Our findings led to the conclusion that such weak (< 0.5 mA) anodal scalp DC, alternated with a cathodal DC, significantly depresses the excitability of the human motor cortex, providing evidence that a small electric field crosses the skull and influences the brain. A possible mechanism of action of scalp DC is the hyperpolarization of the superficial excitatory interneurones in the human motor cortex.     

Polymeric Amines Induce Nitric Oxide Release from S-Nitrosothiols

Catalytic generation of nitric oxide (NO) from NO donors by nanomaterials has enabled prolonged NO delivery for various biomedical applications, but this approach requires laborious synthesis routes. In this study, a new class of materials, that is, polymeric amines including polyethyleneimine (PEI), poly-L-lysine, and poly(allylamine hydrochloride), is discovered to induce NO generation from S-nitrosothiols (RSNOs) at physiological conditions. Controlled NO generation can be readily achieved by tuning the concentration of the NO donors (RSNOs) and polymers, and the type and molecular weight of the polymers. Importantly, the mechanism of NO generation by these polymers is deciphered to be attributed to the nucleophilic reaction between primary amines on polymers and the SNO groups of RSNOs. The NO-releasing feature of the polymers can be integrated into a suite of materials, for example, simply by embedding PEI into poly(vinyl alcohol) (PVA) hydrogels. The functionality of the PVA/PEI hydrogels is demonstrated for Pseudomonas aeruginosa biofilm prevention with a ≈ 4 log reduction within 6 h. As NO has potential therapeutic implications in various diseases, the identification of polymeric amines to induce NO release will open new opportunities in NO-generating biomaterials for antibacterial, antiviral, anticancer, antithrombotic, and wound healing applications.     

Revisiting Steroidogenic Pathways in the Human Placenta and Primary Human Trophoblast Cells

Steroid hormones play a crucial role in supporting a successful pregnancy and ensuring proper fetal development. The placenta is one of the principal tissues in steroid production and metabolism, expressing a vast range of steroidogenic enzymes. Nevertheless, a comprehensive characterization of steroidogenic pathways in the human placenta and potential developmental changes occurring during gestation are poorly understood. Furthermore, the specific contribution of trophoblast cells in steroid release is largely unknown. Thus, this study aimed to (i) identify gestational age-dependent changes in the gene expression of key steroidogenic enzymes and (ii) explore the role of trophoblast cells in steroid biosynthesis and metabolism. Quantitative and Droplet Digital PCR analysis of 12 selected enzymes was carried out in the first trimester (n = 13) and term (n = 20) human placentas. Primary trophoblast cells (n = 5) isolated from human term placentas and choriocarcinoma-derived cell lines (BeWo, BeWo b30 clone, and JEG-3) were further screened for gene expression of enzymes involved in placental synthesis/metabolism of steroids. Finally, de novo steroid synthesis by primary human trophoblasts was evaluated, highlighting the functional activity of steroidogenic enzymes in these cells. Collectively, we provide insights into the expression patterns of steroidogenic enzymes as a function of gestational age and delineate the cellular origin of steroidogenesis in the human placenta.