Unsteady State Effectiveness Factor for Immobilized-Enzyme Reaction

The unsteady state concentration profiles of substrate in immobilized-enzyme particles were calculated numerically for the Michaelis-Menten kinetics. The analytical solution of the profile was also derived when the reaction was approximated to be of the first-order. The integration of the profile gives an unsteady state effectiveness factor. The unsteady state effectiveness factor was obtained under various conditions. The critical time at which a pseudo-steady state approximately holds, was presented graphically as a function of the steady state effectiveness factor for various V₀( ＝Kₘ/Cᴀ₀) values. The charts indicate that the pseudo-steady state is achived within 10-20s under usual operating conditions

Centrifuge Tests and Simple Analyses for Seismic Soil-Structure Interaction

Dynamic centrifuge tests were performed on a superstructure-footing model that was placed on a dry sand surface and subjected to two different input motions having peak accelerations of 60 cm/s2 and 249 cm/s2. Two simple analyses, equivalent linear analysis (SHAKE) and dynamic response of a structure using a sway-rocking model (SR-model) were performed. The following conclusions were drawn: (1) SHAKE and SR-model analyses can simulate the recorded response of the soil and superstructure. However, the shear wave velocity of the ground that can simulate the superstructure response by an SR-model for amax=249 cm/s2 is much smaller than that of the free field estimated using SHAKE. (2) The observed relation of the base friction force with relative displacement between the footing base and the ground surface shows strong nonlinearity when amax=249 cm/s2, which probably results from the large shear deformation of the thin layer beneath the footing

Methods for Estimating Effective Diffusivity of Substrate and Kinetic Parameters of Immobilized Enzyme

Two methods were presented for estimating simultaneously the kinetic parameters in the Michaelis-Menten equation, Kₘ and Vₘₐₓ, and the intraparticle effective diffusivity of substrate, Dₑᴀ, from the results of the transient changes in a batch reactor. The methods were applied to the estimation of the Kₘ and Vₘₐₓ values of α-chymotrypsin immobilized into firebrick particles or acrylamide gel, and the Dₑᴀ values of substrate through the supports. The experimental data of conversions both in the batch and tubular reactors were found to be calculated successfully by using the kinetic and transport parameters estimated by the proposed methods

Prediction of pathologic node-negative clinical stage IA lung adenocarcinoma for optimal candidates undergoing sublobar resection

ObjectivePatients with pathologic node-negative early lung cancer may be optimal candidates for sublobar resection. We aimed to identify predictors of pathologic lymph node involvement in clinical stage IA lung adenocarcinoma.MethodsThe data from a multicenter database of 502 patients with completely resected clinical stage IA lung adenocarcinoma were retrospectively analyzed to determine the relationship between the lymph node metastasis status and tumor size on high-resolution computed tomography (HRCT) or maximum standardized uptake value (SUVmax) on [18F]-fluoro-2-deoxy-d-glucose positron emission tomography/computed tomography (FDG-PET/CT). Revised SUVmax was used to correct interinstitutional discrepancies.ResultsIn multivariate analyses, either a solid tumor size on HRCT (P = .001) or an SUVmax on FDG-PET/CT (P = .049) was an independent predictor of lymph node metastasis. The predictive criteria of pathologic node-negative early lung cancer were a solid tumor size of less than 0.8 cm or an SUVmax of less than 1.5. Patients who met the predictive criteria of pathologic node-negative disease had less pathologic invasiveness, such as lymphatic, vascular, or pleural invasion (P < .001), and better disease-free survival (P < .0001) than those who did not, and 86 (40.4%) of the 213 patients with T1b (2-3 cm) tumors met the predictive criteria.ConclusionsEither a solid tumor size or an SUVmax was a significant independent predictor of nodal involvement in clinical stage IA lung adenocarcinoma. The pathologic node-negative status criteria of a solid tumor size of less than 0.8 cm on HRCT or an SUVmax of less than1.5 on FDG-PET/CT may be helpful for avoiding systematic lymphadenectomy for clinical stage IA lung adenocarcinoma, even in cases of T1b (2-3 cm) tumor

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

A Case of Diffuse Alveolar Hemorrhage Associated with Tegafur Plus Uracil and Warfarin Therapy

A 72-year-old man who received warfarin for myocardial infarction (prothrombin time-international normalized ratio [PT-INR] controlled between 2.2 and 2.5) for 2 years. He developed lung cancer, underwent surgery, and received tegafur plus uracil (UFT) after 1 month. After 2 months, he was admitted for hemoptysis and dyspnea. Chest radiography and computed tomography showed bilateral alveolar infiltration (PT-INR, 8.9). Bronchoalveolar lavage fluid (BALF) disclosed hemorrhagic features in sequential samples. And he was diagnosed with diffuse alveolar hemorrhage (DAH). A known interaction exists between fluoropyrimidines and warfarin. So, they were discontinued, and vitamin K was intravenously administered. One day later, the PT-INR returned to 1.14. The symptoms improved and, alveolar infiltration resolved after 2 weeks. Alveolar hemorrhage may be due to an interaction between UFT and warfarin. When fluoropyrimidines and warfarin are prescribed simultaneously, we recommend that PT-INR should be closely monitored

Encapsulation of krill oil by spray drying

[EN] An oil from Pacific krill (Euphausia pacifica) has a high content of PUFAs and phospholipids. The sediment was formed with homogenization of krill oil and maltodextrin (MD; dextrose equivalent (DE) = 19) solution using sodium caseinate, gum arabic, hydrolyzed whey protein or modified starch as a surfactant. Quillaja saponin could form the emulsion without the sediment. MD (28.5 wt%) was solubilized with distiller water (50 wt%) and mixed with krill oil (20wt%) and Quillaja saponin (1.5 wt%). The homogenized solution was spray-dried using Okawara-L8 spray dryer with a centrifugal atomizer. Spray-dried powder was evaluated in the oil-droplet size and surface-oil content.This research was supported by grants from the Project of the NARO Bio-oriented Technology Research Advancement Institution (the special scheme project on vitalizing management entities of agriculture, forestry and fisheries).Takashige, S.; Hermawan Dwi, A.; Sultana, A.; Shiga, H.; Adachi, S.; Yoshii, H. (2018). Encapsulation of krill oil by spray drying. En IDS 2018. 21st International Drying Symposium Proceedings. Editorial Universitat Politècnica de València. 587-594. https://doi.org/10.4995/IDS2018.2018.7323OCS58759

Detection and management of cardiomyopathy in female dystrophinopathy carriers

Regular health checkups for mothers of patients with Duchenne muscular dystrophy have been performed at National Hospital Organization Tokushima Hospital since 1994. Among 43 mothers participated in this study, 28 dystrophinopathy carriers were identified. Skeletal and cardiac muscle functions of these subjects were examined. High serum creatine kinase was found in 23 subjects (82.1%). Obvious muscle weakness was present in 5 (17.8%) and had progressed from 1994 to 2015. Cardiomyopathy was observed in 15 subjects (60.0%), including dilated cardiomyopathy-like damage that was more common in the left ventricular (LV) posterior wall. Late gadolinium enhancement on cardiac MRI was found in 5 of 6 subjects, suggesting fibrotic cardiac muscle. In speckle tracking echocardiography performed seven years later, global longitudinal strain was decreased in these subjects, indicating LV myocardial contractile abnormality. These results suggest that female dystrophinopathy carriers should receive regular checkups for detection and treatment of cardiomyopathy, even if they have no cardiac symptoms