Search Results - (Author, Cooperation:B. Min)

2011-02-19

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

2013-04-05

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Catalytic Domain ; Holoenzymes/chemistry/genetics/ultrastructure ; Microscopy, Electron ; Models, Molecular ; Nucleic Acid Conformation ; Pliability ; Protein Structure, Tertiary ; Protein Subunits/analysis/chemistry/metabolism ; Protozoan Proteins/chemistry/metabolism/ultrastructure ; RNA/chemistry/metabolism/ultrastructure ; Ribonucleoproteins/chemistry/genetics/metabolism/ultrastructure ; Telomerase/*chemistry/genetics/metabolism/*ultrastructure ; Tetrahymena thermophila/chemistry/*enzymology/genetics/ultrastructure

1077-3118

AIP Digital Archive

Physics

YBa2Cu3O7−δ (YBCO) Josephson junctions in a ramp edge geometry with NdBa2Cu3O7−δ (NBCO) barriers were fabricated by pulsed laser deposition on (100) SrTiO3 substrates. The barrier layer thicknesses were d=100, 200, and 300 A(ring) . The I–V characteristics of YBCO/NBCO/YBCO junctions changed from the resistively shunted junction type to flux-creeplike behavior as temperature decreased. Shapiro steps due to the ac Josephson effect clearly developed under microwave irradiation. The interface between the superconducting (YBCO) and the normal layer (NBCO) turned out to be fairly clean with small interface resistance. The mean value of the measured IcRn product for junctions with 100-A(ring)-thick barriers was 71±34 μV at 77 K. The normal coherence length of the NBCO barrier material was ∼40 A(ring). The SQUIDs, made of superconductor–normal metal–superconductor junctions, showed voltage modulation at 77 K. © 1996 American Institute of Physics.

Electronic Resource

1745-4522

Blackwell Publishing Journal Backfiles 1879-2005

Process Engineering, Biotechnology, Nutrition Technology

Twenty lactating Alpine goats were randomly allocated into four groups to investigate the effect of feeding regimes with concentrates on fatty acid profiles of goat milk and Domiati cheese at different stages of lactation. Pooled milk from each group was collected twice monthly for Domiati cheese making. Cheese was sampled fresh and at 1 and 2 months of pickling in whey. Caproic, caprilic and capric acids in goat milk were recorded at 1.9, 5.5 and 25.1 μg/g of fat, respectively, and accounted for 13.27% of total fatty acids. Total unsaturated fatty acids represented 28.87% of total fatty acids. In Domiati cheese, caproic, caprilic and capric acids were 4.2, 7.4 and 31.4 μg/g of fat, respectively, and accounted for 11.21% of total fatty acids. Total unsaturated fatty acids represented 26.83% of total fatty acids. Fatty acid composition of both milk and cheese was affected by feeding treatments and stages of lactation. All the fatty acids of milk and cheese were lower when goats were pasture-fed compared to other groups except linolenic and stearic acids in goat milk and linolenic acid in cheese. Concentrations of caproic, caprilic, capric, palmitic, myristic and oleic acids fluctuated throughout lactation with the highest values at mid lactation. The above observations indicate that pasture feeding during mid-lactation could result in improved quality and nutritionally healthy goat milk and cheeses.

Electronic Resource

1750-3841

Blackwell Publishing Journal Backfiles 1879-2005

Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition

Process Engineering, Biotechnology, Nutrition Technology

: Lipid oxidation, color, volatiles, and sensory evaluation of double-packaged pork loin were determined to establish a modified packaging method that can improve the quality of irradiated pork loins. Vacuum-packaged irradiated samples produced dimethyl sulfide and dimethyl disulfide responsible for irradiation off-odor, whereas lipid oxidation was promoted under aerobic conditions. Exposing double-packaged irradiated pork to aerobic conditions for 1 to 3 d was effective in controlling both lipid oxidation and irradiation off-odor, regardless of packaging sequence. Sensory panels could distinguish the decrease in irradiation off-odor intensities by modifying the packaging method. However, carbon monoxide heme pigments, responsible for the increased redness by irradiation, were not effectively controlled by double packaging alone.

Electronic Resource

1750-3841

Blackwell Publishing Journal Backfiles 1879-2005

Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition

Process Engineering, Biotechnology, Nutrition Technology

: Breast rolls with 6 antimicrobial additive treatments—no preservatives (control), 0.1% potassium benzoate (PB), 2% sodium lactate (SL), 0.1% potassium benzoate plus 2% sodium lactate (PB + SL), 2% sodium lactate plus 0.1% sodium diacetate (SL + SDA), and 0.1% potassum benzoate, 2% sodium lactate, and 0.1% sodium diacetate (PB + SL + SDA)—were prepared. Samples were irradiated at 0, 1.0, or 2.0 kGy, and then the quality characteristics of turkey rolls were analyzed. Adding 2% SL increased the hardness, springiness, cohesiveness, chewiness, and resilience of breast rolls. Addition of PB or SDA, and irradiation had no significant effect on texture. Adding 2% SL affected color values. The color a* and b* values of turkey rolls with 2% SL added were significantly lower than those of the control, and this difference was maintained after irradiation and during storage. No difference in color and texture was observed between turkey rolls added with SL and those added with SL + PB + SDA. Breast rolls containing antimicrobials had more lipid oxidation than control. Irradiation and storage slightly enhanced lipid oxidation, although the overall lipid oxidation was very low. Irradiation promoted the formation of dimethyl disulfide and dimethyl trisulfide. Adding PB in breast rolls greatly increased the formation of benzene during irradiation, whereas other antimicrobial additives had no significant effects on volatiles.

Electronic Resource

1522-9602

Springer Online Journal Archives 1860-2000

Biology

Mathematics

Abstract Zadeh's transfer function method for linear time-variable systems is used to apply frequency-domain analysis to a periodically time-varying elastance model of the left ventricle. Left ventricular pressure computed from the system function of the time-varying elastance and the phasors of aortic flow shows a typical waveform of the measured ventricular pressure.

Electronic Resource

1522-9602

Springer Online Journal Archives 1860-2000

Biology

Mathematics

Abstract A performance criterion and weighting factors for the optimal cardiac assistance are investigated by applying Tellegen's network theorem and tolerance analysis on animal experimental data for left ventricular (LV) bypass on the failing heart. Two major factors with respect to cardiac assistance (total power delivered to the peripheral circulatory system, and changes in temporal pattern of ventricular contraction) are represented by two performance criteria,J 1 andJ 2 whereJ 1 relates to the sum of LV and pump power, andJ 2 relates to the “peakedness” factor of LV power. The total performance index (J) is determined as the weighted sum ofJ 1 andJ 2;J=w 1J1+w2J2. The weighting factors,w 1 andw 2, are computed as inverses of the tolerance in the performance contours with respect to improvement of stroke work per minute from pre- to post-bypass condition.

Electronic Resource

1522-9602

Springer Online Journal Archives 1860-2000

Biology

Mathematics

Abstract Analytical techniques are developed which permit objective control of asiist device driving systems. In addition to being objective, the techniques described in this paper are optimal in the sense of minimizing a performance index which consists of a term involving left ventricular power and a term involving deviations of aorta hemodynamic parameters from normal values. Comparisons are included of off-line computations and measurements on dogs with experimentally induced myocardial infarctions undergoing intraaortic balloon pumping.

Electronic Resource

1436-2449

Springer Online Journal Archives 1860-2000

Chemistry and Pharmacology

Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics

Physics

Summary The low temperature relaxation of epoxy resin modified with siloxane oligomers was investigated by using thermally stimulated current (TSC) and relaxation map analysis (RMA). The β-relaxation of epoxy resin and the glass transition temperature of siloxane oligomer were folded and shifted to higher temperature as the concentration of trifluoropropyl (TFP) in siloxane oligomer increased. In the systems containing over 50% of TFP a new relaxation peak due to the dipole orientation was observed at around-45°C. As the concentration of TFP increased the compensation temperature (Tc) and the degree-of-disorder (DOD) were increased while the compensation time, τc was decreased.

Electronic Resource

1432-0800

Springer Online Journal Archives 1860-2000

Energy, Environment Protection, Nuclear Power Engineering

Medicine

Electronic Resource

0092-8240

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Mathematics

Electronic Resource

0092-8240

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Mathematics

Electronic Resource

1432-1041

midazolam ; 1-hydroxymethylmidazolam ; pharmacokinetics ; dose proportionality ; benzodiazepine ; healthy volunteers ; side-effects

Springer Online Journal Archives 1860-2000

Chemistry and Pharmacology

Medicine

Summary The pharmacokinetics of midazolam and 1-hydroxymethylmidazolam were investigated following oral administration of 7.5, 15 and 30 mg doses of midazolam in solution to 12 healthy subjects. Compared to the 7.5 mg dose, the Cmax and AUC parameters of both midazolam and 1-hydroxymethylmidazolam increased proportionally after the 15 mg dose and more than proportionally after the 30 mg dose. The t1/2 for midazolam remained relatively constant between the 7.5 and 15 mg doses whereas it increased slightly but significantly after the 30 mg dose. These data indicated that the pharmacokinetics of midazolam and 1-hydroxymethylmidazolam were linear between the 7.5 and 15 mg oral dose range. However, after the 30 mg dose, the systemic availability of midazolam and the AUC for 1-hydroxymethylmidazolam appeared to be greater than that anticipated from the lower doses, possibly due to saturation of midazolam first-pass metabolism. This ist not expected to have any clinical significance under the conditions of therapeutic use.

Electronic Resource

1432-8798

Springer Online Journal Archives 1860-2000

Medicine

Summary.  A novel virus we call zucchini green mottle mosaic virus (ZGMMV) was isolated from zucchini squash and its properties were determined. The size and shape of its virions, and other properties suggest that the virus is a tobamovirus. The coat protein (CP) genes of ZGMMV and kyuri green mottle mosaic virus (KGMMV), which also infects zucchini squash plants, were cloned and their nucleotides sequences were determined. The CP genes of ZGMMV and KGMMV are composed of 161 amino acid residues, and they share 77.6% amino acid identity. Western blot analysis showed that the two viruses are serologically related but not identical. Comparison of the sequences with those of sixteen other tobamoviruses revealed that the two viruses had much higher identity to cucumber green mottle mosaic virus (CGMMV), another tobamovirus infectious to cucurbit plants, than other tobamoviruses. The nucleotide and amino acid sequences of ZGMMV were from 29.5 to 78.4% and from 29.3 to 77.6% identical, respectively, to those of other tobamoviruses. The predicted virion assembly origins of the two tobamoviruses were located in the CP region of the genomic RNAs, and the predicted secondary structures were more similar to that of CGMMV than those of other tobamoviruses. The seventeen tobamo-viruses could be classified into three main subgroups based on the cphylogenetic tree analysis on the CP gene, and ZGMMV and KGMMV formed a third subgroup together with CGMMV and sunn-hemp mosaic virus (SHMV). These results show that ZGMMV is a previously unknown member of the Tobamovirus genus.

Electronic Resource

1573-4803

Springer Online Journal Archives 1860-2000

Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics

Abstract A method is proposed for measuring the rheology of cement paste under conditions that suppress shear flow, i.e. squeezing. This method is based on squeezing samples in a servohydraulic compression-tension testing machine, and is different from the commonly used shear flow experiments. Possible artefacts such as the buoyancy of the piston that penetrates the paste, sedimentation of cement paste, geometry of the container, and friction at the interface between the top plate (or piston) and sample are investigated. Plots of stress versus apparent strain were obtained and compared with results from standard shear flow experiments. Because cement paste has both viscoelastic and viscoplastic characteristics, results are analysed in terms of both solid-like deformation and liquid-like flow behaviour. A first-approximation theoretical analysis is developed, based on the assumption that cement paste behaves as a non-Newtonian liquid, and results are compared with the experimental results.

Electronic Resource

1573-4803

Springer Online Journal Archives 1860-2000

Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics

Abstract Physical ageing behaviour of a semicrystalline polymer, polypropylene, has been studied at a pressure-temperature state (P=2.5 kbar,T=15° C) for which the amorphous region is in the glassy state. Polypropylene contains 57% crystallinity and its glass transition temperature at atmospheric condition is −20° C. The ageing behaviour was monitored by measuring the Young's modulus (E) from the stress-strain curves as a function of ageing time up to 200 h. The Young's modulus of the rapidly pressure quenched samples increased at 0.4% per ageing hour of the initial value for up to 30 h and tapered off thereafter. The glassy polypropylene also exhibited a memory behaviour when it was given a pressure perturbation.

Electronic Resource

1573-4803

Springer Online Journal Archives 1860-2000

Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics

Abstract Thermal cycling induced deformations of a unidirectionally reinforced graphite fibre-magnesium matrix composite are analysed with a micromechanical elastic-plastic model. The model is capable of describing the cyclic thermal behaviour as influenced by the matrix plasticity including strain hardening and Bauschinger effects. The analysis traces the entire thermal history over 18 cycles in the ±100° C range. Predictions correlate well with measured strains, especially in terms of trends in the coefficient of thermal expansion. The results suggest further attention is required for time and temperature dependent stress relaxation rates and the role of defects.

Electronic Resource

1573-904X

pharmacokinetics ; food ; interaction ; zalcitabine ; HIV infection

Springer Online Journal Archives 1860-2000

Chemistry and Pharmacology

Abstract Purpose. The purpose of this study was to determine the effect of food on the pharmacokinetics of zalcitabine in HIV-positive patients. Methods. Twenty patients received single oral 1.5 mg doses of zalcitabine with and without a standard breakfast in an open-label, randomized crossover study with at least a one week washout period between treatments. Serial blood and urine samples were collected over 24 hours and assayed for zalcitabine by a modified GC/MS method. Results. Administration with food delayed and prolonged absorption resulting in a decrease of approximately 39% in maximal plasma concentrations compared to dosing under fasting conditions. Comparison of plasma AUC values indicated a small (14%) reduction in bioavailability when given with food. Approximately 59% and 45% of the dose were excreted unchanged in the urine under fasting and fed conditions, respectively. Conclusions. The results of this study show that the administration of zalcitabine with food results in a mild reduction in bioavailability. Although these changes are not expected to be of clinical importance, further studies must be conducted for confirmation.

Electronic Resource

1573-904X

pharmacokinetics ; zalcitabine ; probenecid ; interaction ; HIV-infection

Springer Online Journal Archives 1860-2000

Chemistry and Pharmacology

Abstract Purpose. The purpose of this study was to determine the potential effect of probenecid on the pharmacokinetics of zalcitabine in HIV-positive patients. Methods. Twelve patients received single oral 1.5 mg doses of zalcitabine alone and during probenecid treatment (500 mg at 8 and 2 hours before and 4 hours after zalcitabine dosing) in an open-label, randomized two-way crossover study with a one-week washout period between treatments. Serial blood and urine samples were collected over a 24 hour period and assayed for zalcitabine by a modified GC/MS method. Results. Coadministration of probenecid with zalcitabine resulted in a decrease in mean (%CV) renal clearance of zalcitabine from 310 (28%) ml/min when zalcitabine was given alone to 180 (22%) ml/min with probenecid and a prolonged half-life from 1.7 hours to 2.5 hours. Mean AUCs increased from 59 ng·h/ml when zalcitabine was given alone to 91 ng·h/ml when given with probenecid. Considering the short half-life of zalcitabine (1–3 hours) relative to its dosing schedule, the pharmacokinetic changes observed in this study are not expected to result in significant accumulation during chronic dosing. Conclusions. The results of this study show that co-administration of probenecid with zalcitabine results in a moderate decrease in renal clearance of zalcitabine due to inhibition of renal tubular secretion and a 50% increase in drug exposure. Although well tolerated in this single-dose study, patients taking this combination should be monitored closely for signs of toxicity and dosage reduction should be considered if warranted.

Electronic Resource