156 research outputs found
Bilateral Iliopsoas Hematomas under Sedation:A Complication of Postoperative Therapy after Coronary Artery Bypass Grafting
We report a case of bilateral iliopsoas hematomas that occurred during postoperative therapy after coronary artery bypass grafting (CABG). An 81-year-old woman receiving anticoagulant and antiplatelet therapies under sedation after CABG developed sudden anemia and went into shock. Abdominal ultrasonography showed a right retroperitoneal hematoma. She improved gradually with conservative treatment. Many patients with an iliopsoas hematoma complain of low-abdominal pain or femoral neuropathy, but such local signs may be absent under sedation. In anticoagulant and antiplatelet therapies under sedation, when the cause of anemia and shock is not clear, we should suspect peritoneal hematoma and examine the peritoneal space.</p
Endpoint Strichartz estimates and global solutions for the nonlinear Dirac equation
We prove endpoint Strichartz estimates for the Klein-Gordon and wave equations in mixed norms on the polar coordinates in three spatial dimensions. As an application, global wellposedness of the nonlinear Dirac equation is shown for small data in the energy class with some regularity assumption for the angular variable
Method of Preparing a Chiral Substrate Surface By Electrodeposition
A solid substrate comprising a surface comprising an achiral array of atoms having thereupon a chiral metal oxide surface. The chiral metal oxide surface is prepared by electrodeposition of a chiral metal oxide array from a solution of a chiral salt of the metal. In one embodiment, chiral CuO is grown on achiral Au(001) by epitaxial electrodeposition. The handedness of the film is determined by the specific enantiomer of tartrate ion in the deposition solution. (R,R)- tartrate produces an S—CuO(l 1 T) film, while (S,S)-tartrate produces an R—CuO(Tl 1) film. These chiral CuO films are enantiospecific for the electrochemical oxidation of(R,R) and (S,S)-tartrate
Lipase-Catalyzed Synthesis of Unsaturated Acyl L-Ascorbates and Their Ability to Suppress the Autoxidation of Polyunsaturated Fatty Acids
ABSTRACT: L-Ascorbic acid and various polyunsaturated fatty acids (PUFA) were condensed at 55°C by the immobilized lipase Chirazyme L-2 in dry acetone to produce the unsaturated acyl ascorbates. The PUFA moieties of the products were much more resistant to autoxidation at 65°C and nearly 0% relative humidity than the corresponding unmodified PUFA. The effects of the molar ratio of ascorbic acid or linoleoyl ascorbate to linoleic acid on the autoxidation of linoleic acid were examined. The autoxidation of linoleic acid was effectively suppressed at molar ratios greater than or equal to 0.2 when either ascorbic acid or linoleoyl ascorbate was mixed with linoleic acid. The addition of lauroyl ascorbate, synthesized through the enzyme-catalyzed condensation of ascorbic acid and lauric acid in acetone, to docosahexaenoic acid also significantly suppressed the autoxidation of docosahexaenoic acid at molar ratios of ≥0.2. Paper no. J9826 in JAOCS 78, 823-826 (August 2001). KEY WORDS: Acyl ascorbate, L-ascorbic acid, autoxidation, condensation, immobilized lipase, polyunsaturated fatty acid. Much attention has been paid to the use of polyunsaturated fatty acids (PUFA) as components in foods (1). However, PUFA are susceptible to autoxidation (2,3), and the autoxidation causes deterioration of the foods. L-Ascorbic acid is a hydrophilic antioxidant with a strong reducing ability. The lipase-catalyzed synthesis of acyl ascorbate in a solid-phase system (4) or in an organic solvent (5-9) has been reported. However, its ability to suppress lipid autoxidation has not been reported. In a previous paper (10), we reported the synthesis of 6-O-eicosapentaenoyl L-ascorbate by the lipase-catalyzed condensation of eicosapentaenoic acid and L-ascorbic acid in acetone and compared its autoxidation process to that of the unmodified eicosapentaenoic acid. In the work described in this paper, some PUFA L-ascorbates were synthesized using an immobilized lipase from Candida antarctica, Chirazyme ® L-2, and their autoxidation processes were then observed. The PUFA used were linoleic, α-linolenic, γ-linolenic, arachidonic, and docosahexaenoic acids. The effect of the molar ratio of unmodified L-ascorbic acid or linoleoyl ascorbate to linoleic acid on the suppression of the autoxidation of linoleic acid was examined. We previously reported the lipase-catalyzed condensation of ascorbic acid with various medium-chain fatty acids having carbon numbers of 6, 8, 10, and 12 in acetonitrile (11). Therefore, the ability of lauroyl ascorbate to suppress the autoxidation of docosahexaenoic acid was also evaluated in the present work. EXPERIMENTAL PROCEDURES Materials. γ-Linolenic and docosahexaenoic acids were supplied by the Maruha Corporation (Tokyo, Japan), and their purities were both greater than 95% based on gas chromatographic (GC) analysis. L-Ascorbic acid, linoleic acid, acetone, and hexane were purchased from Nacalai Tesque (Kyoto, Japan). α-Linolenic, arachidonic, and lauric acids were purchased from Sigma Chemical (St. Louis, MO). Immobilized lipase from C. antarctica, Chirazyme ® L-2 c.-f. C2, was obtained from Roche Molecular Biochemicals (Mannheim, Germany). The enzyme is the same as Novozym ® 435 according to the manufacturer. Soybean oil was purchased from Wako Pure Chemical Industries (Osaka, Japan). Condensation reaction. Acetone was first dehydrated by adding 5 Å molecular sieves. The water content of the acetone was about 0.01% (vol/vol), and was determined for each experiment by a Karl-Fischer titration. L-Ascorbic acid (0.125 mmol) and a PUFA [linoleic acid (0.577 mmol)], γ-linolenic acid (0.600 mmol), arachidonic acid, (0.638 mmol), α-linolenic acid (0.611 mmol), and docosahexaenoic acid (0.648 mmol)] were weighed into an amber glass vial with a screw cap, and 200 mg of Chirazyme L-2 and 2.5 mL of dehydrated acetone were added to the vial. The headspace of the vial was filled with nitrogen, and the vial was tightly sealed. The vial was then immersed in a waterbath at 55°C with vigorous shaking to commence the condensation reaction. At appropriate intervals, 10 µL of the reaction mixture was taken and mixed with 50 µL of a 50 mM solution of toluene in high-performance liquid chromatography (HPLC) eluent [acetonitrile/tetrahydrofuran/0.1% (vol/vol) phosphoric acid (50:22:28 by vol) as the internal standard for the HPLC analysis and then with 40 µL of HPLC eluent. The analysis was carried out by HPLC with a YMC-Pack C8 column (4.6 mm × 250 mm; YMC Inc., Kyoto, Japan) and an ultraviolet (UV) detector (245 nm). The mixture (20 µL) was applied to the column and eluted with the eluent at 1.5 mL/min. The retention times o
Extracellular Electron Transfer via Outer Membrane Cytochromes in a Methanotrophic Bacterium Methylococcus capsulatus (Bath)
Electron exchange reactions between microbial cells and solid materials, referred to as extracellular electron transfer (EET), have attracted attention in the fields of microbial physiology, microbial ecology, and biotechnology. Studies of model species of iron-reducing, or equivalently, current-generating bacteria such as Geobacter spp. and Shewanella spp. have revealed that redox-active proteins, especially outer membrane c-type cytochromes (OMCs), play a pivotal role in the EET process. Recent (meta)genomic analyses have revealed that diverse microorganisms that have not been demonstrated to have EET ability also harbor OMC-like proteins, indicating that EET via OMCs could be more widely preserved in microorganisms than originally thought. A methanotrophic bacterium Methylococcus capsulatus (Bath) was reported to harbor multiple OMC genes whose expression is elevated by Cu starvation. However, the physiological role of these genes is unknown. Therefore, in this study, we explored whether M. capsulatus (Bath) displays EET abilities via OMCs. In electrochemical analysis, M. capsulatus (Bath) generated anodic current only when electron donors such as formate were available, and could reduce insoluble iron oxides in the presence of electron donor compounds. Furthermore, the current-generating and iron-reducing activities of M. capsulatus (Bath) cells that were cultured in a Cu-deficient medium, which promotes high levels of OMC expression, were higher than those cultured in a Cu-supplemented medium. Anodic current production by the Cu-deficient cells was significantly suppressed by disruption of MCA0421, a highly expressed OMC gene, and by treatment with carbon monoxide (CO) gas (an inhibitor of c-type cytochromes). Our results provide evidence of EET in M. capsulatus (Bath) and demonstrate the pivotal role of OMCs in this process. This study raises the possibility that EET to solid compounds is a novel survival strategy of methanotrophic bacteria
Geochemical CO2 trapping in open aquifer storage — the Tokyo Bay model
AbstractNumerical simulation using TOUGHREACT software has shown that more than 20Mt of CO2 can be stored for a period up to 10,000 years in a 2-D model system taking from the geology of the Tokyo Bay area. Carbonate precipitation occurs extensively in the front of enlarging plume, forming a shell enclosing CO2. The distribution of dawsonite is predicted to be dependent on the dissolution of plagioclase which presents abundantly in sandstones of the Tokyo Bay area as well as those in young sedimentary strata of Japanese Islands, suggesting its potential importance in the mineral trapping of CO2
Macroscopically uniform and flat lithium thin film formed by electrodeposition using multicomponent additives
It is well-known that the electrodeposition of lithium usually results in the formation of dendrites on the electrode surface. This limits the utilization of metallic lithium as a material for, for example, the negative electrodes of rechargeable batteries. In aqueous solutions, similar dendritic growth of metals is often observed during electrodeposition; however, utilization of multicomponent additives has overcome this shortcoming. Here, we report that the simultaneous utilization of four different additives greatly suppresses the formation of lithium dendrites during electrodeposition in a tetraglyme-based solution. The roles of the additives are discussed, based on the results of electrochemical quartz crystal microbalance measurements and X-ray photoelectron spectroscopy
Extensive Atrophic Gastritis Increases Intraduodenal Hydrogen Gas
Objective. Gastric acid plays an important part in the prevention of bacterial colonization of the gastrointestinal tract. If these bacteria have an ability of hydrogen (H2) fermentation, intraluminal H2 gas might be detected. We attempted to measure the intraluminal H2 concentrations to determine the bacterial overgrowth in the gastrointestinal tract. Patients and methods. Studies were performed in 647 consecutive patients undergoing upper endoscopy. At the time of endoscopic examination, we intubated
the stomach and the descending part of the duodenum without inflation by air, and 20 mL of intraluminal gas samples of both sites was collected through the biopsy channel. Intraluminal H2 concentrations were measured by gas chromatography. Results. Intragastric and intraduodenal H2 gas was detected in 566 (87.5%) and 524 (81.0%) patients, respectively. The mean
values of intragastric and intraduodenal H2 gas were 8.5 ± 15.9 and 13.2 ± 58.0 ppm, respectively. The intraduodenal H2 level was
increased with the progression of atrophic gastritis, whereas the intragastric H2 level was the highest in patients without atrophic gastritis. Conclusions. The intraduodenal hydrogen levels were increased with the progression of atrophic gastritis. It is likely that the influence of hypochlorhydria on bacterial overgrowth in the proximal small intestine is more pronounced, compared to that
in the stomach
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