Stereospecific analysis of soybean triacylglycerols

Thirty soybean germplasm lines representing a wide distribution of fatty acid compositions were analyzed stereospecifically by using a chiral column to resolve the sn-1 and sn-3 positions of glycerol. The amounts of each acyl group on each of the sn positions were plotted vs. the amount of that acyl group in the triacylglycerols (TAG), and the plots were fitted by linear regression. The deviation of individual data points from the linear regressions was much greater than observed in previous studies. This could be attributed to the inclusion of a number of germplasm lines with elevated or reduced percentages of saturates. The stereospecific distributions could not be fit with previously suggested mathematical models because the plots had intercepts that were not allowed by the models. Statistical tests of the analytical procedure indicated that slight oxidation of or bias against the polyunsaturates had occurred and that the Grignard deacylation method gave slightly less representative analyses of the sn-2 position than pancreatic lipase deacylation on these TAG.     

Cerebral energy levels during trimethaphan-induced hypotension in the rat: effects of light versus deep halothane anesthesia

Hypotension may be expected to produce less perturbation of metabolism in the brain when cerebral metabolic rate is lowered by deep anesthesia. Male Wistar rats having unilateral carotidartery ligation were exposed to mean arterial pressure (MAP) of 40 torr for 22 min by an intravenous infusion of trimethaphan during anesthesia with halothane, 0.6 or 2 per cent, in oxygen. Cortical tissue metabolite levels on the side of the ligated carotid artery were more abnormal in rats receiving halothane, 0.6 per cent, than in those receiving halothane, 2 per cent. Values at halothane, 0.6 per cent, were adenosine triphosphate (ATP), 1.71 +/- 0.05 (+/-SEM) mumol/g, phosphocreatine (PCr) 1.97 +/- 0.07 mumol/g. and lactate 16.5 +/- 5.1 mumol/g; corresponding values at halothane, 2 per cent, were ATP 2.27 +/- 0.02, PCr 4.02 +/- 0.23, and lactate 4.75 +/- 0.9 mumol/g. ATP and PCr values were significiantly lower (P less than 0.05) and the lactate value was significantly higher with halothane, 0.6 per cent, than with halothane 2 per cent. Cerebral oxygen consumption decreased 47 per cent in rats anesthetized with halothane, 2 per cent. Preservation of cortical metabolite levels in deeply anesthetized animals suggests a protective effect of cerebral metabolic depression.     

Angiotensin II-induced association of phospholipase Cgamma1 with the G-protein-coupled AT1 receptor

An early event in signaling by the G-protein-coupled angiotensin II (Ang II) AT1 receptor in vascular smooth muscle cells is the tyrosine phosphorylation and activation of phospholipase Cgamma1 (PLCgamma1). In the present study, we show that stimulation of this event by Ang II in vascular smooth muscle cells is accompanied by binding of PLCgamma1 to the AT1 receptor in an Ang II- and tyrosine phophorylation-dependent manner. The PLCgamma1-AT1 receptor interaction appears to depend on phosphorylation of tyrosine 319 in a YIPP motif in the C-terminal intracellular domain of the AT1 receptor and binding of the phosphorylated receptor by the most C-terminal of two Src homology 2 domains in PLCgamma1. PLCgamma1 thus binds to the same site in the receptor previously identified for binding by the SHP-2 phosphotyrosine phosphatase.JAK2 tyrosine kinase complex. A single site in the C-terminal tail of the AT1 receptor can, therefore, be bound in a ligand-dependent manner by two different downstream effector proteins. These data demonstrate that G-protein-coupled receptors can physically associate with intracellular proteins other than G proteins, creating membrane-delimited signal transduction complexes similar to those observed for classic growth factor receptors.     

Association of social relationships with depressive symptoms: Testing an alternative to social support.

Low social support and expressed emotion have been associated with depression, but no studies examined their relative contributions. A self-report questionnaire was developed to measure family emotional involvement and perceived criticism to assess the main components of family expressed emotion. 83 family practice patients older than 40 yrs responded to a survey assessing depressive symptoms, social support, life events, and expressed emotion. Perceived criticism, intense emotional involvement, and negative life events were all independently associated with depressive symptoms. After controlling for expressed emotion, the association of low social support with depressive symptoms was no longer statistically significant. Results support the primacy of family interactions (with high perceived criticism and emotional involvement) over low social support in explaining the association between social relationships and depression. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Processing and Performance of MOF (Metal Organic Framework)-Loaded PAN Nanofibrous Membrane for CO<Subscript>2</Subscript> Adsorption

The objective of this experimental study is to produce a nanofibrous membrane functionalized with adsorbent particles called metal organic framework (MOF) in order to adsorb CO₂ from a gas source. Therefore, Polyacrylonitrile (PAN) was chosen as the precursor for nanofibers and HKUST-1, a Cu-based MOF, was chosen as adsorbent. The experimental process consists of electrospinning PAN solution blended with HKUST-1 to produce a nanofibrous mat as working substrates. The fibers were collected in a cylindrical canister model. SEM image of this mat showed nanofibers with the presence of small adsorbent particles, impregnated into the as-spun fibers discretely. To increase the amount of MOF particles for effectual gas adsorption, a secondary solvothermal process of producing MOF particles on the fibers was required. This process consists of multiple growth cycles of HKUST-1 particles by using a sol-gel precursor. SEM images showed uniform distribution of porous MOF particles of 2-4 µm in size on the fiber surface. Energy dispersive spectroscopy report of the fiber confirmed the presence of MOF particles through the identification of characteristic Copper elemental peaks of HKUST-1. To determine the thermal stability of the fibrous membrane, Thermogravimetric analysis of HKUST-1 consisting of PAN fiber was performed where a total weight loss of 40% between 210 and 360 °C was observed, hence proving the high-temperature durability of the synthesized membrane. BET surface area of the fiber membrane was measured as 540.73 m²/g. The fiber membrane was then placed into an experimental test bench containing a mixed gas inflow of CO₂ and N₂. Using non-dispersive infrared CO₂ sensors connected to the inlet and outlet port of the bench, significant reduction of CO₂ in concentration was measured. Comparative IR spectroscopic analysis between the gas-treated and gas untreated fiber samples showed the presence of characteristic peak in the vicinity of 2300 and 2400 cm^?1 which verifies the adsorption of CO₂.     

Inter-asperity cavitation and global cavitation in seals: : an average flow analysis

A universal, average Reynolds equation was previously developed to model the combined effects of inter-asperity cavitation and global cavitation in lubricating films between rough surfaces. In this study, the universal, average Reynolds equation is applied to two types of rotating shaft seals: lip seals and mechanical face seals. Inter-asperity cavitation is shown to affect the sealing mechanism of lip seals and to influence the behavior of new, worn, and wavy mechanical face seals.     

Evaluation of periparturient dairy cows and contact surfaces as a reservoir of Cryptosporidium parvum for calfhood infection

To compare the effects of salmeterol, an adrenergic drug, and ipratropium bromide, an anticholinergic drug, on breathlessness and gas exchange during exercise in patients with chronic obstructive lung disease (COPD), we performed a progressive treadmill exercise test on 15 patients on 3 days (24 h apart), after inhalation placebo, ipratropium bromide (120 micrograms) or salmeterol (50 micrograms) in a randomized fashion. Dyspnoea during exercise was evaluated from the regression slope between Borg scale (BS) scores and distance walked each minute on the treadmill. The regression was expressed as the distance walked at BS score 5, the threshold load of dyspnoea (TLD) and breakpoint load of dyspnoea. During and after the exercise, oxygen saturation was monitored by pulse oxymeter and we measured the lower SaO2 during exercise and the recovery time of SaO2 after exercise. In comparison to placebo inhalation we found the same small but significant improvement in airflow limitation after salmeterol or ipratropium inhalation, also the distance walked on treadmill increased after bronchodilators. After bronchodilators the magnitude of oxyhaemoglobin desaturation with exercise was similar to that observed after placebo but the duration of the recovery from sustained SaO2 desaturation after exercise was shorter to the same extent as after ipratropium or salmeterol. Dyspnoeic sensation, when assessed by the TLD and by the distance walked at BS score 5, was decreased after salmeterol and after ipratropium bromide to a similar extent. We conclude that the salmeterol, when given in conventional doses, produces significant improvement in the airway obstruction in the recovery of postexercise HbO2 desaturation and in dyspnoeic sensation in patients with COPD, effects which were similar to those observed after inhalation of the anticholinergic agent ipratropium bromide.     

Plasma-Sprayed Aluminum and Titanium Adherends: I. Characterization of Coatings

The morphological and surface chemical properties of plasma-sprayed coatings on metals have been investigated using surface characterization techniques. Organic polymeric and inorganic powders were plasma-sprayed on aluminum and titanium. Organic-polymeric coatings were prepared using epoxy, polyester, polyimide, and cyanate ester components. Inorganic coatings were obtained by plasma-spraying Al₂O₃, AlPO₄, MgO, and SiO₂ on aluminum adherends, and TiO₂, TiSi₂, MgO, and SiO₂ on titanium adherends. The organic-polymeric coatings were prepared at one thickness while the inorganic coatings were sprayed to obtain two different thicknesses. SEM photographs reveal various morphological differences in the sprayed specimens. The surface morphology ranged from smooth to nodular among the plasma-sprayed specimens. Surface chemical analysis of the plasma-sprayed coatings indicated that little or no chemical degradation of the components occurred as a result of plasma-spraying. However, plasma-sprayed TiSi₂ appeared to be a mixture of silica and a titanium silicate.