Aqueous-Lipid Transdermal Formulation of Anti-Inflammatory Agents, Prepared with Hydrogenated Soya Phospholipid

The in vitro transport of various anti-inflammatory agents were examined using rat dorsal skin and shed snake skin as models of the stratum corneum for the evaluation of transdermal formulation. The aqueous-lipid vehicle formulations prepared with hydrogenated soya phospholipid increased the transport of ketoprofen and sodium diclofenac, and an addition of tetradecanol to the formulation increased the transport of both drugs more markedly. The amounts of drug (%) transported during 12 h with rat dorsal skin and during 24 h with shed snake skin was about 50% for ketoprofen and about 30 % for sodium diclofenac. The aqueous-lipid formulation including tetradecanol also increased the transport of indomethacin, but only about 10 %. It is suggested that the small effect of the aqueous-lipid vehicle formulation on indomethacin transport is due to the low solubility of indomethacin in the vehicle.     

Interaction between active hydrogen sites on carbon black surface and alcohol molecules

The interaction of active hydrogen sites on carbon black surface with alcohol molecules was studied using a calorimetrical method. The immersional heats of the blacks into ethanol and n-butanol increase linearly with an increase in the content of active hydrogen on the surface. This tendency is quite similar to that observed for the immersional heats into water. The energy contributions of the active hydrogen containing functional groups to the heats of immersion into ethanol and n-butanol were 37.7 and 34.2 kJ/mol respectively. They are approx. $\text{1}\text{4}$ of the value observed in the case of water (142.4 kJ/mol). The hydrogen bonding energy between n-butanol molecules and active hydrogen sites on the surface of Peerless-155 was determined by applying the analytical procedure of average electrostatic field strength described by Zettlemoyer. The electrostatic interaction energy of the field on the carbon black's surface with the dipole of the n-butanol molecule, q_μ and the hydrogen bonding energy of its active hydrogen site with n-butanol molecule, q_μ, were 17.8 and 16.4 kJ/mol respectively, per 1 mole of the surface active hydrogen. The energy contribution of the active hydrogen to the heat of immersion into n-butanol, 34.2 kJ/mol, agrees with the sum of q_μ and q_h. It is concluded that the interaction of the active hydrogen site with the immersed molecule is electrostatic and of hydrogen bonding type in the case of alcohols, whereas, in the case of water, dissociation-hydration reactions are also involved (as was suggested previously).     

A 21-mW 4-Mb CMOS SRAM for battery operation

The authors describe a 21-mW 4-mB CMOS SRAM for the application of memory systems which operate on 3-V batteries. A low active power is achieved by novel circuit technologies. A thin-film transistor (TFT) load memory cell effectively reduces standby current to 0.4 μA. A new multibit test circuit, which permits measurement of access time, is also introduced for a reduction of the test time. The authors describe the characteristics of the TFT memory cell and the improved memory cell design for stable cell operation. The 0.6-μm process technology used to fabricate the 4-Mb SRAM and the chip performance are outlined     

Femoral and spinal bone mineral density in Japanese osteoporotics with hip fracture

In the present study, bone mineral density (BMD) of femoral neck and lumbar spine was compared between 38 Japanese female patients with hip fracture (age 63-89 years, mean +/- SD 76 +/- 7 years) and 162 age-matched female controls (age 62-90 years, mean +/- SD 75 +/- 7 years). BMD was measured in the femoral neck and lumbar spine (L2-4) using dual-photon absorptiometry (Norland model 2600). BMD values of femoral neck as well as lumbar spine were significantly lower in patients with hip fracture than in controls (0.504 +/- 0.097 v 0.597 +/- 0.101, p < 0.01, for femoral neck; 0.661 +/- 0.146 v 0.720 +/- 0.128, p < 0.05, for lumbar spine). Patients with hip fracture and controls were stratified according to their BMD levels at two measuring sites, and the ratio of the number of patients and controls at each BMD level was calculated as an indicator of fracture rate. This ratio showed an exponential increase as the femoral neck BMD declined, but only a gradual increase as the lumbar spine BMD declined. Specificity-sensitivity analysis revealed that BMD values of 0.59 and 0.54 g/cm2 at the femoral neck provided a specificity of 52% and 68% with a sensitivity of 90% and 75%, respectively. These findings suggest that Japanese patients with hip fracture are more osteoporotic than age-matched controls and that the selective measurement of femoral neck would be useful for predicting the risk of hip fracture.     

Preferred test conditions for measuring flow rate distribution between cells in a polymer electrolyte fuel cell stack

A new and practical testing technique was developed for measuring the flow rate distribution between cells in a stack that did not contain any internal sensors. The flow rate distribution is obtained by measuring the hydrogen limiting current of each cell in the stack while a mixed gas of hydrogen and dimethyl ether is supplied to the anode and hydrogen to the cathode. In order to measure large flow rate deviations between cells, it is necessary to decrease the flow rate of the anode hydrogen and to sufficiently humidify the cells. The faster the increasing rate of the current, the more the apparent hydrogen limiting current increases than the theoretical electrochemical equivalent current. However, the relative flow rate deviations between cells can be obtained by a practical accuracy using the ratio of the apparent hydrogen limiting current. Humidification of the cell is indispensable for the measurement and a method using dry anode gas and humidified cathode gas is recommended. The preferred test conditions for measuring the flow rate distribution between cells in a PEFC stack are proposed.     

Trend report on international and Japanese standardization activities for bioceramics and tissue engineered medical products

Since porous and injectable bioceramics have recently been utilized often as scaffolds for bone regenerative medicine, the need for their standardization has increased. One of the standard proposals in ISO/TC150 and JIS has been a draft for characterization of the porous bioceramic scaffolds in both micro- and macro-scopic aspects. ISO/TC150/SC7 (Tissue engineered medical products) has been co-chaired by Professor J E Lemons, Department of Surgery, University of Alabama at Birmingham and Dr R Nakaoka, Division of Medical Devices, National Institute of Health Sciences, Japan. The scope of SC7 has been specified as ‘Standardization for the general requirements and performance of tissue engineered medical products with the exclusion of gene therapy, transplantation and transfusion’.     

Difference in surface reactions between titanium and zirconium in Hanks' solution to elucidate mechanism of calcium phosphate formation on titanium using XPS and cathodic polarization

Titanium and zirconium were immersed in Hanks' solution with and without calcium and phosphate ions, and the surfaces were characterized with X-ray photoelectron spectroscopy (XPS) to determine the mechanism of calcium phosphate formation on titanium in simulated body fluids and in a living body. In addition, they were cathodically polarized in the above solutions. XPS characterization and cathodic polarization revealed differences in the surface properties in the ability of calcium phosphate formation between titanium and zirconium. The surface oxide film on titanium is not completely oxidized and is relatively reactive; that on zirconium is more passive and protective than that on titanium. Neither calcium nor phosphate stably exists alone on titanium, and calcium phosphate is naturally formed on it; calcium phosphate formed on titanium is stable and protective. On the other hand, calcium is never incorporated on zirconium, while zirconium phosphate, which is easily formed on zirconium, is highly stable and protective. Our study presents new information regarding the surface property of titanium and demonstrates that the characteristics of titanium and zirconium may be applied to various medical devices and new surface modification techniques.     

Tunable distributed feedback lasing with a threshold in the nanojoule range in an organic guest-host polymeric waveguide

Tunable distributed feedback lasing was achieved in a guest-host polymeric waveguide using holographic dynamic gratings. Tris(8-quinolinolato)aluminum (Alq) as a host and 4-(dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4H-pyran (DCM) as a guest emitter were dispersed in poly(N-vinyl carbazole) (PVCz) matrix. Emission of both the TE(0) and the TM(0) modes was measured. Effective energy transfer from PVCz to DCM through Alq assisted in the reduction of the threshold of laser emission. The threshold of 38 nJ/pulse was measured for first-order lasing and that of 53 nJ/pulse for second-order lasing.     

Correlation of fat content and dioxins, total mercury and methyl mercury levels in tuna

In this study, we analyzed the concentrations of mercury and dioxins in tuna with various fat contents (akami; the leaner meat, Chutoro; the belly area of the tuna along the side of the fish between the akami and the otoro. Otoro; the fattiest portion of the tuna) in wild and farmed bluefin tuna and farmed southern bluefin tuna. In the three kinds of tuna, average dioxins concentrations in Akami, chutoro and otoro were 1.7, 4.7 and 9.6 pg TEQ/g, respectively. The dioxins concentration in all three regions of tuna was in direct proportion to the fat content. In the farmed bluefin tuna, the dioxins concentration was almost the same as that of the wild tuna, but differed from that of the farmed southern bluefin tuna. Average total mercury concentration based on wet weight in akami was 0.42 μg/g, being higher than the values of 0.36 μg/g of chutoro and 0.31 μg/g of otoro, and in inverse proportion to the fat content. In all three regions, the total mercury concentration of the wild bluefin tuna was equal to that of the farmed tuna. The total mercury concentration in the latter was two to three times higher than that of the farmed southern bluefin tuna. If the Japanese intake is one fin of tuna (80 g) a day, the daily intake levels of dioxins and methyl mercury can be estimated as 0.48-37 pg TEQ/kg bw and 0.21-0.90 μg/kg bw, respectively.     

Effect of terminal functional groups of silane layers on adhesive strength between biomedical Ti-29Nb-13Ta-4.6Zr alloy and segment polyurethanes

Composite materials that consisted of a biomedical β-type titanium alloy, Ti-29Nb-13Ta-4.6Zr alloy (TNTZ) with low Young's modulus and segment polyurethane (SPU) have been fabricated for application in biomedical devices. The effects of different kinds of terminal functional groups and the thickness of the silane layers (SIL) on the adhesive strength between TNTZ and SPU were investigated by means of shear bonding tests. The following silane coupling agents were employed in this study: 3-methacryloxypropyltrimethoxysilane (γ-MPTS), aminopropyltriethoxysilane (APS), and 3-mercaptopropyltrimethoxysilane (γ-MPS). Furthermore, the shear bonding strength of the TNTZ/SIL/SPU interface was also characterized after immersion in water for 30 d.