A blinking periorbital prosthesis using surface electromyographic signals of the orbicularis oculi muscle.

BACKGROUND: Recent advances in human-machine interface technology have enabled the development of multifunctional, primarily orthopedic myoelectric prostheses. We developed a noninvasive blinking periorbital prosthesis that can synchronize with blinking of the intact eyelid by using surface electromyographic signals of the orbicularis oculi muscle. METHODS: Myoelectric potentials of the orbicularis oculi muscle while blinking were measured with surface electrodes on the eyelid in four healthy adults. Possible cross talk introduced via the electrodes was also measured and assessed to determine whether cross talk would affect surface electromyographic measurements while blinking. RESULTS: The amplitude of the surface myoelectric potential of the orbicularis oculi muscle was sufficiently high for the practical use of blinking prostheses. Our blinking model was successfully synchronized with blinks of the subjects' eyelids under experimental conditions without cross talk between the orbicularis oculi muscle and other muscles. CONCLUSIONS: Although our study revealed several problems, the use of surface electromyographic signals could be a promising and useful technique for synchronizing blinking of the prosthetic eyelid with blinking of the intact eyelid. Level of Evidence: Level V, therapeutic study.

A basic study on hypericin-PDT in vitro.

The effect of photo dynamic therapy (PDT) using hypericin as a photosensitiser and the effect of PDT on intracellular ATP levels using different lamps in a human leukemic monocyte lymphoma cell line (U937) were studied. The time required for hypericin to penetrate into the cancer cells was 1h, and incubation for more than 3h post-irradiation with hypericin-PDT was required to observe effects. Thus, if cancer cell death does not occur immediately following irradiation, it is unnecessary to perform additional irradiation, as most of the cells die via apoptosis during the incubation period post-irradiation. When hypericin-PDT was performed using a Na-Li lamp as a light source, the cell viability decreased approximately 55% immediately following irradiation for 5 min; however, after a 5-h post-irradiation incubation, the cell viability approached 0%. Concurrently, intracellular ATP levels increased markedly; thus, irradiation (0.225 J/cm(2)) for 5 min provided the best results in terms of the highest degree of cancer cell apoptosis. Similar experiments were performed using three different LED lamps respectively. When cells were treated with the LED lamps, with maximum peaks of 599 nm and 595 nm, the cell viability approached 0% after incubation for 5h following 15 min of irradiation (0.04 J/cm(2) and 0.099 J/cm(2), respectively). We confirmed that incubating the cells for more than 3h in a 100 × diluted hypericin solution was the most effective for PDT and that a LED lamp of low light intensity led to the highest apoptosis rate in the U937 cells.

Three-dimensional replica of a life-sized model of aortic arch aneurysm for preoperative assessments.

PURPOSE: In the treatment of extended distal aortic arch aneurysms with open stent grafting, detailed preoperative minute evaluation is essential to determine the optimal operative strategy and reduce the incidence of complications. We describe a three-dimensional replica of a life-sized aortic arch aneurysm model for aiding preoperative assessments. DESCRIPTION: Life-sized replicas of an aortic arch aneurysm were made for 4 patients who underwent total aortic arch replacement with open stent-grafting. These replicas were used to determine the curve of the CLATE, a newly developed open stent delivery system (Senko Medical Instrument Mfg, Co, Ltd, Tokyo, Japan), and the depth of the open stent grafting. The replica and the CLATE system were also used to obtain informed consent from the patients. EVALUATION: Surgeons could simulate the operative procedure precisely. Insertion of the graft was smooth in all patients. Use of the replica made it easier for the patients to understand the form and site of the aneurysm, as well as the operative procedure. CONCLUSIONS: The combination of the three-dimensional replica and the CLATE system may be useful for both surgeons and patients in the treatment of extended distal aortic arch aneurysms.

Stability of superoxide ion in imidazolium cation-based room-temperature ionic liquids.

The stability of superoxide ion (O(2)(*-)) generated chemically by dissolving KO(2) in dried dimethyl sulfoxide solutions containing imidazolium cation [e.g., 1-ethyl-3-methylimidazolium (EMI(+)) and 1-n-butyl-2,3-dimethylimidazolium (BMMI(+))] based ionic liquids (ILs) was investigated with UV-visible spectroscopic, NMR, and voltammetric techniques and an ab initio molecular orbital calculation. UV-visible spectroscopic and cyclic voltammetric measurements reveal that the O(2)(*-) species reacts with BMMI(+) and EMI(+) cations of ILs to form hydrogen peroxide. The pseudo first order rate constant for the reaction of BMMI(+) and O(2)(*-) species was found to be about 2.5 x 10(-3) s(-1). With a molecular orbital calculation, the O(2)(*-) species is understood to attack the 2-position (C-2) of the imidazolium ring (i.e., BMMI(+)) to form an ion pair complex in which one oxygen atom is bounded to C-2 and the other to the hydrogen atom of -CH(3) group attached to C-2. Eventually, the ion pair complex of BMMI(+) cation and O(2)(*-) species undergoes a ring opening reaction as evidenced with (1)H NMR measurement.

Enhancement in skin permeation of 5-aminolevulinic acid using l-menthol and its derivatives.

Enhancing effect of l-menthol and its derivatives, l-menthyl formate, l-menthyl acetate, and l-menthyl propionate, on skin permeation of 5-aminolevulinic acid (ALA) through Yucatan micropig full-thickness skin was investigated using a Franz-type diffusion cell. ALA solutions were prepared using ethanol-water mixed solvents with l-menthol or the derivative. Skin permeation coefficients (Kp) of ALA with more than 3.0 wt% of l-menthol was significantly larger than that without l-menthol. In addition, Kp of ALA with the derivative increased as follows: l-menthol approximately l-menthyl propionate < l-menthyl formate < l-menthyl acetate. These results suggest that l-menthol and the derivative are effective to enhance ALA skin permeation.

The breath ammonia measurement of the hemodialysis with a QCM-NH3 sensor.

Recently, expired gases are analyzed non-invasively for monitoring the substances in the blood. Breath ammonia has been shown to correlate with BUN (blood urea nitrogen) and Cr (creatinine), both of which are indicators of solute removal in hemodialysis. In this study, breath ammonia concentration was continuously measured using a crystal oscillator QCM (quartz crystal microbalance) during the expiration of patients undergoing dialysis treatment. The results show that NH3 (ammonia) decreased gradually as the treatment proceeded. A strong correlation was observed between changes in the frequency of the QCM gas sensor and both the pre-dialysis BUN level (r=0.71, p<0.05) and the post-dialysis BUN level (r=0.90, p<0.05). NH3 was found to fall precipitously during dialysis. The differences were statistically significant. In addition, we found a statistically significant correlation between BUN and NH3 in expired gas. These results suggest that continuous measurement of NH3 is useful to assess the status of solute removal during hemodialysis.

Oxidation decomposition of unsaturated fatty acids by singlet oxygen in phospholipid bilayer membranes.

Oxidation decomposition of unsaturated fatty acids with singlet oxygen generated from a photosensitizing agent was investigated in liposome bilayer membranes under a light irradiation condition. The liposome of which the bilayer membrane was composed of L-alpha-dipalmitoylphosphatidylcholine (DPPC), protoporphyrin IX (PpIX), and an unsaturated fatty acid (oleic acid, linoleic acid, alpha-linolenic acid, or arachidonic acid) were prepared with Bangham's method. In irradiating the liposome dispersion with light ranged from 550 to 750 nm, the unsaturated fatty acid was decomposed through an oxidation reaction with singlet oxygen. The decomposition rate constant was obeyed as the following order: arachidonic acid > oleic acid > alpha-linolenic acid > linoleic acid. This result indicates that oleic acid is readily degraded despite its lower unsaturated degree. In addition, micropolarity and microfluidity of the hydrocarbon region in the liposome bilayer membrane including the unsaturated fatty acid and PpIX decreased with an increase in light irradiation time. These findings suggest that interaction among the hydrocarbon chains of DPPC in the liposome bilayer membrane is promoted by migration of the oxidized unsaturated fatty acid from the hydrocarbon region, leading to form close-packed and well-ordered orientation of the hydrocarbon chains.

Basic study on apoptosis induction into cancer cells U-937 and EL-4 by ultrasound exposure.

Recently, the low invasive cancer treatments with small aftereffects have been considered. We are studying on the suppression methods of cancer cell proliferation with ultrasound. Cancer cells of mouse T lymphoma (EL-4) have been used in our study. The human histitocytic lymphoma cells (U-937) was used in this time. The cancer cells were cultured in a culture medium of RPMI1640. The standing wave acoustic field was formed in a water tank of our ultrasound exposure system by a vibrating plate driven with a Langevine type transducer. The U-937 and EL-4 were exposed to ultrasound in the acoustic field with spatial average acoustic intensity of 350 mW/cm(2) at 150 kHz. The viable rate of EL-4 decreased with the lapse of culture time after ultrasound exposure. U-937 did not show the remarkable decrease tendency. The proliferation of U-937 which exposed to ultrasound with 700 mW/cm(2) was suppressed. It can be thought that apoptosis was induced in the cancer cells in this condition. We observed the morphological change on the U-937 exposed to ultrasound with this condition. The morphological changes by apoptosis like the shrink of cells, formation of apoptotic bodies etc. can be observed with an optical microscope and a phase contrast microscope.

Evaluation of blood access dysfunction based on a wavelet transform analysis of shunt murmurs.

We investigated shunt murmurs based on wavelet transform analysis as a new method for assessing vascular access function. In the present study, in patients with venous stenosis near an arteriovenous fistula (A-V fistula), a sensor was placed at different positions around the stenosis and shunt murmur signals obtained using a measurement system were subjected to time-frequency analysis based on wavelet transforms. The shunt murmurs obtained from the stenotic region closely represented some features of murmurs that are often referred to as "high-pitch" murmurs in the clinical setting. In contrast, shunt murmurs obtained about 5 cm downstream of the stenotic region closely represented some features of murmurs that are often referred to as "low-pitch" murmurs in the clinical setting. Furthermore, with the aim of extending the lifespan of arteriovenous grafts (A-V grafts) by detecting and treating stenotic lesions before the A-V graft becomes occluded, we evaluated the possibility of utilizing the present shunt murmur analysis for monitoring stenosis in such A-V grafts. When shunt murmurs from patients with A-V grafts were analyzed, the results suggested that the blood flow through the venous anastomosis of the graft was the most turbulent. This present method whereby blood flow in an A-V fistula is assessed based on the frequency distribution on a time-frequency plane by wavelet transform analysis is advantageous because findings are not markedly affected by sensor attachment. Furthermore, because the sensor is attached using an adhesive collar, measurements can be taken over a short period of time before each dialysis session.

Improving dispersion of nanometer-size diamond particles by acoustic cavitation.

A novel acoustic-dispersion method for fine diamond particles was developed. Two samples of nanometer-sized diamond particles were used. They had primary particle sizes of 5 nm (ND5) and 150 nm (ND150). Disaggregation of agglomerated particles using ultrasound and surface modification of ND5 and ND150 were investigated. The ND5 and ND150 particles aggregated to secondary particles, having sizes on the order of micrometers. The surfaces of ND5 and ND150 particle were modified due to chemical reactions and the particles were disaggregated by acoustic cavitation. The ND5 particles were disaggregated to give an average particle size of about 100 nm by ultrasound exposure with average acoustic intensities higher than 800 W/m(2). The agglomerated ND150 particles with size of 15 microm were disaggregated to reach an average particle size of about 300 nm by ultrasound exposure with an average acoustic intensity higher than 2000 W/m(2). The surfaces of ND5 and ND150 particles were found to be modified with hydroxyl groups resulting from acoustic cavitation. This could lead to a well dispersed solution of nanometer-sized diamond particles in water.

Immobilization and enzymatic activity of glucose oxidase on polystyrene surface modified with ozone aeration and UV irradiation in distilled water and/or aqueous ammonia solution.

Adsorption condition and enzymatic activity of glucose oxidase (GOD) on polystyrene (PS) film surfaces modified with ozone aeration and UV irradiation (O3/UV) treatment were investigated. The total amount of GOD immobilized on the PS film modified with the O3/UV treatment in distilled water (PS-W film) was approximately twice as large as that on the film treated in an aqueous ammonia solution (PS-A film), whereas the specific activity of GOD on the PS-A film was four times higher than that on the PS-W film. In contrast, no enzymatic activity of GOD on the non-treated PS film was observed because of irreversible denaturation of the adsorbed GOD. We therefore conclude that the PS films modified by the O3/UV treatment in the aqueous media are effective in immobilizing GOD.

Size and surface charge effect of 5-aminolevulinic acid-containing liposomes on photodynamic therapy for cultivated cancer cells.

5-Aminolevulinic acid (ALA)-containing liposomes having various average diameters and/or positive surface charges were prepared, and their photodynamic therapy (PDT) efficacy for murine thymic lymphoma cells, EL-4 cells, cultivated in vitro was investigated. The PDT efficacy for EL-4 cells and the accumulation of ALA-induced protoporphyrin IX (PpIX) in the cells increased with a decrease in the average diameter of liposomes. In particular, the ALA-containing liposomes smaller than 63.5 nm in diameter promoted the PDT efficacy in comparison with that of ALA alone. We also found no significant changes in PDT efficacy and PpIX accumulation with increasing positive surface charges of liposomes.

A high-voltage dye-sensitized photocapacitor of a three-electrode system.

A high-voltage photo-rechargeable capacitor (photocapacitor) of three-electrode configuration, comprising a dye-sensitized mesoporous TiO2 electrode, two carbon-coated electrodes, and two liquid electrolytes, attained a charge-state voltage of 0.8 V and high energy density per area of 47 microW h cm(-2) which is five times larger than the previous two-electrode photocapacitor.

Effect of defect size on fracture strength of dental low fusion porcelain.

Various grinding defects were produced on the surface of specimen dental low fusion porcelain in an attempt to establish the relationship between defect size and fracture strength. In addition, the applicability of the process zone size-fracture criterion in assessing the material properties of dental low fusion porcelain was examined. Super porcelain AAA E3 (Noritake Co., Japan) was used as dental low fusion porcelain. The bending strength and fracture toughness value were estimated by the three-point bending test. After glazing, grinding flaws were introduced by grinding the specimen with abrasive papers of various mesh sizes. In order to calculate the fracture toughness value of dental low fusion porcelain, we introduced a surface crack using a Vickers indenter. The results were discussed based on the process zone size-fracture criterion. The size of cracks caused by grinding was estimated with the process zone size-fracture criterion and Newman-Raju formula. As the defect size decreased, the fracture stress approached the strength for smooth specimen without defect. The K(c) value showed a tendency to approach the K(lc) value when the defect size increased. The relationship between the fracture stress, sigma(F), and the equivalent crack length, a(e), was in good agreement with the theoretical relations deduced from the criterion in dental low fusion porcelain.

Sintering behavior and apatite formation of diopside prepared by coprecipitation process.

Sintering behavior and bioactivity of diopside, CaMgSi(2)O(6), prepared by a coprecipitation process were examined for its biomedical applicability. As-prepared powder was synthesized by adding aqueous ammonia to an ethanol solution containing Ca(NO(3))(2).4H(2)O, Mg(NO(3))(2).6H(2)O, and Si(OC(2)H(5))(4) and characterized by means of TG-DTA, XRD, and TG-MS. The dried powder was X-ray amorphous and crystallized into diopside at 845.5 degrees C. The glass network formation by SiO(4) tetrahedra was almost completed below 800 degrees C. The bioactivity of the diopside prepared by sintering the compressed powder at 1100 degrees C for 2h was evaluated by immersion of the sintered body in a simulated body fluid (SBF) at 36.5 degrees C. Leaf-like apatite particles were found to be formed on the surface of the sintered body and grew with passage of soaking time. This apatite-forming behavior in the SBF is related to the dissolution of Ca(II) ions from the sintered body in the early stage of immersion. Thus, diopside prepared by the coprecipitation process using the metal alkoxide and the metal salts was found to have an apatite-forming ability.

Delta-aminolevulinic acid-based photodynamic therapy for acne on the body.

Intractable acne on the body was clinically treated with photodynamic therapy (PDT) combining oral administration of delta-aminolevulinic acid (ALA) with polychromatic visible light from a metal halide lamp. The total number of body acne patients was 51. A 10 mg/kg B.W. of ALA was administered to the patients, and the acne lesions were exposed to the light emitted from the metal halide lamp. The wavelengths of the light ranged from 540 to 800 nm. The diameter of the irradiated area and the irradiating distance from the lamp were 100 mm and 130 mm, respectively. Under the irradiation conditions, the total fluence rate and the energy-density uniformity of the light were 69.2 mW/cm2 and 11.5%. The total light energy dose in one session was 60-80 J/cm2 for the body. All patients underwent two sessions of PDT and received no other treatments after PDT or during the follow-up period. The interval between the two PDT sessions was 2-4 weeks. The physician's clinical assessment scores as worsened, unchanged, improved, and markedly improved were 0 (0%), 4 (7.8%), 16 (31.4%), and 31 (60.8%) patients, respectively. Adverse effects of very slight discomfort, burning, and stinging were reported during the irradiation. The blood tests of patients before and after oral administration of ALA demonstrated that no liver dysfunction occurred in this study with ALA dosages within 10 mg/kg B.W. Consequently, orally administered ALA-PDT with a metal halide lamp was considered to be effective for treatment of acne on the body.