Resting and acetazolamide-challenged technetium-99m-ECD SPECT in transient global amnesia

This report describes the case of a 42-yr-old woman with systemic lupus erythematosus who presented with septic shock. Initially, a source of infection could not be found and the patient was started on stress dose corticosteroids and antibiotics. A CAT scan revealed thickened colon and endoscopy revealed possible ischemic colitis. She soon developed peritonitis, and was taken to surgery where gastrointestinal mucormycosis was found. The patient died despite amphotericin therapy.     

Characteristics of behavior of robots with emotion model

A cooperative multirobot system has much dominance over a single‐robot system. It is able to adapt to various circumstances and has flexibility for variation of tasks. However, it still has problems of controlling each robot, although methods for control of a multirobot system have been studied. Recently, emotion and sensitivity of the robots have been widely studied. In this study, a human emotion model based on psychological interaction was adapted to a multirobot system to achieve methods for organization of multiple robots. The characteristics of behavior of multirobot systems achieved through computer simulation were analyzed. As a result, very complex and interesting behavior emerged even though it is of rather simple configuration. And it has flexibility in various circumstances. Additional experiments with actual robots will be conducted based on the emotion model. © 2005 Wiley Periodicals, Inc. Electr Eng Jpn, 153(4): 32–38, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20167     

Effects of ultrasonic irradiation on the viscosity of fuel oils

Fuel oil A, B and C, and a residual oil from vacuum distillation (R-Oil) have been irradiated with 25kHz ultrasonic waves (150W) at 50 °C for 10 h. The observed increases in the kinematic viscosity (Δ v%) are: fuel oil A, 0.3%; fuel oil B, 5.3%; fuel oil C, 17.6%; and R-Oil 5.5%. The value and sign of Δ v are found to change with the sample weight in the flask, l.r. measurements show that ultrasonic irradiation causes the intensities of CH₂ and CH₃ to decrease slightly. The ultrasonic energy appears to be used in the breaking-up and/or coupling of the petroleum molecules.     

Two-Dimensional Interlayer Space Induced Horizontal Transformation of Metal–Organic Framework Nanosheets for Highly Permeable Nanofiltration Membranes

Laminar membranes comprising graphene oxide (GO) and metal–organic framework (MOF) nanosheets benefit from the regular in-plane pores of MOF nanosheets and thus can support rapid water transport. However, the restacking and agglomeration of MOF nanosheets during typical vacuum filtration disturb the stacking of GO sheets, thus deteriorating the membrane selectivity. Therefore, to fabricate highly permeable MOF nanosheets/reduced GO (rGO) membranes, a two-step method is applied. First, using a facile solvothermal method, ZnO nanoparticles are introduced into the rGO laminate to stabilize and enlarge the interlayer spacing. Subsequently, the ZnO/rGO membrane is immersed in a solution of tetrakis(4-carboxyphenyl)porphyrin (H₂TCPP) to realize in situ transformation of ZnO into Zn-TCPP in the confined interlayer space of rGO. By optimizing the transformation time and mass loading of ZnO, the obtained Zn-TCPP/rGO laminar membrane exhibits preferential orientation of Zn-TCPP, which reduces the pathway tortuosity for small molecules. As a result, the composite membrane achieves a high water permeance of 19.0 L m⁻² h⁻¹ bar⁻¹ and high anionic dye rejection (>99% for methyl blue).     

Axial resolution and the value of interpolating scan in multislice positron computed tomography

We have calculated the aperture function of a positron computed tomograph (PCT) with computer simulation, and evaluated the axial resolution of a multislice PCT, Positologica III, both theoretically and experimentally. The axial point spread function (PSF) was approximately a triangle at or near the center of the field, and the sensitivity for the slice decreased significantly as the source moved away off the image plane. Accordingly, there were low sensitivity areas between an in-plane and the adjacent cross-plane. This invisible region was clinically significant if the object was thin enough in the z-axis. In order to fill up the gaps between adjacent slices, it is valuable to move the patient half the slice interval in the z-axis and perform an " interpolating scan."     

Synthesis and surface-active properties of trimeric-type anionic surfactants derived from tris(2-aminoethyl)amine

Trimeric-type anionic surfactants (3C_ntaAm, where n is a hydrocarbon chain length of 8, 10, or 12) with three hydrocarbon chains and three carboxylate headgroups were synthesized from tris(2-aminoethyl)amine, and their properties were investigated by surface tension, electrical conductivity, dynamic and static light-scattering, fluorescence of pyrene, and emulsification power techniques. The critical micelle concentrations (CMC) of 3C_ntaAm were 0.00092–0.00834 mmol dm⁻³, and the surface tensions at the CMC were 33.3–39.9 mN m⁻¹. The areas per molecule occupied by 3C₁₀taAm and 3C₁₂taAm were extremely small, showing they were highly compact at the air/water interface. In addition, adsorption or micellization behavior of 3C_ntaAm was estimated by parameters such as pC ₂₀ (the efficiency of surface adsorption), CMC/C ₂₀ (the ease of adsorption relative to the ease of micellization), and ΔG _M ^o (Gibbs energy of micellization). Dynamic and static light-scattering mesurements of 3C_ntaAm showed a hydrodynamic radius of 45–61 nm above the CMC and aggregation numbers of 10–82 at the CMC, respectively. The fluorescence intensity ratio of the first to the third band in the emission spectra of pyrene started to lower from far above the CMC for 3C₈taAm and 3C₁₀taAm, and below the CMC for 3C₁₂taAm. This suggests that loose micelles or premicellar aggregates are formed in solutions. Mixtures of aqueous solutions of 3C_ntaAm and toluene formed oil-in-water-type emulsions, and the stabilizing abilities were in the order of 3C₈taAm>3C₁₀taAm>3C₁₂taAm. The degree of emulsification of 3C₈taAm remained at 69% after 24 h of standing. Thus, 3C_ntaAm exhibited unique properties superior to monomeric or dimeric surfactants that were significantly influenced by their hydrocarbon chain lengths.     

Environmental degradation of biodegradable polyesters. IV. The effects of pores and surface hydrophilicity on the biodegradation of poly(ϵ‐caprolactone) and poly[(R)‐3‐hydroxybutyrate] films in controlled seawater

Poly(?‐caprolactone) (PCL) and poly[(R)‐3‐hydroxybutyrate] (R‐PHB) films with pores and hydrophilic surfaces were prepared by the water extraction of poly(ethylene oxide) from as‐cast blend films (1:1) and by the alkali treatment of as‐cast nonporous films, respectively. These films, as well as as‐cast nonporous PCL and R‐PHB films, were biodegraded in static seawater kept at 25°C, and their biodegradation was monitored with gravimetry, gel permeation chromatography (GPC), and scanning electron microscopy. The pores or highly hydrophilic surfaces of the PCL and R‐PHB films enhanced their biodegradation in seawater. Moreover, GPC measurements could be used to trace the biodegradation in seawater when the biodegradation proceeded to a great extent. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 587–593, 2003     

Stereocomplex formation between enantiomeric poly(lactic acid)s. X. Binary blends from poly(D-lactide-CO-glycolide) and poly(L-lactide-CO-glycolide)

Binary blend films from lactide-rich poly(D -lactide-co-glycolide) (PDLG) and poly(L -lactide-co-glycolide) (PLLG) were obtained by casting methylene chloride solutions of the two mixed copolymers with different D- and L-lactide contents (X_DI and X_LI ), and their crystallization was studied by differential scanning calorimetry (DSC). Four combinations were selected from the binary (A-B) blends: mixing of the same polymer [X_DI (A) = X_DI (B) or X_LI (A) = X_LI(B)], blending under X_DI (B) = X_LI (A), blending of a D -lactide homopolymer [X_DI(B) = 1] with other PDLGs, and blending of a D -lactide homopolymer [X_DI(B) = 1] with other PLLGs. Racemic crystallites were exclusively formed between PDLG and PLLG when they had high lactide unit contents. The melting point and enthalpy of fusion of the racemic crystallites decreased with a decrease in X_DI of PDLG or X_LI of PLLG, suggesting that glycolide units in the polymer disturbed the growth of the racemic crystallites. A similar behavior was also observed for the homocrystallization in nonblended copolymer films. Homocrystallites composed entirely either of D -lactide unit or L-lactide unit sequences were formed when one component was crystallizable and the other component had the same sign of optical rotation or very different lactide content. An interesting finding was that even nonhomocrystallizable lactide-poor PDLG and PLLG could form racemic crystallites when both were blended. © 1994 John Wiley & Sons, Inc.     

Substitution of Sodium and Silicon in Tricalcium Aluminate

Four types of tricalcium aluminate solid solutions with different concentrations of Na₂O and SiO₂ were prepared and examined using an electron probe microanalyzer. The atomic ratios, including those determined in a previous study, were derived from the oxide compositions and provided excellent correlations between Ca and Na + Si (i.e., Ca = 3.003 − 0.48[Na + Si]), and Al and Si (Al = 1.997 − 1.02Si). Because the replacement reactions, Ca²⁺↔ 2Na⁺ and Ca²⁺+ 2Al³⁺↔ 2Si⁴⁺, independently occur within the same crystal, these reactions have been simply combined together to generate a new formula, Na_{2 x} Ca_{3− x − y} (Al_{1− y} Si _y )₂O₆, where x is the amount of Ca substituted by Na, and y is the amount of Al substituted by Si. This formula leads to the equations Ca = 3 − 0.5[Na + Si] and Al = 2 − Si, which nicely account for the constrained chemical variation of the actual solid solutions with 0 ≤ x < 0.049 and 0 ≤ y < 0.073.