Development of dark-field dynamic light scattering microscopy and its application: Tracking dynamics of particles in condensed slurries spreading on planar/nonplanar substrates.

HYPOTHESIS: While dynamics of particles in slurries is usually evaluated by dynamic light scattering measurements, this technique had only been applicable to particles in the bulk slurries. Because this limitation is mainly owing to strong reflection of light, the dynamics of particles in slurries spreading/drying on solid substrates is to be obtained by spatially separating the reflection light from scattering (signal) light. This may allow us to track the particles in practical samples such as cosmetics or inks spreading on solid surfaces. EXPERIMENT: We developed novel "dark-field dynamic light scattering microscopy". The system was evaluated with test samples of polystyrene beads dispersed in several viscosities of bulk glycerol aqueous solutions. This setup was then applied to slurries spreading/drying on planar and nonplanar substrates. FINDINGS: The results for planar surface indicate that origin of coffee-ring are the particles flowing into the edge of the droplet just before complete drying. On a skin-modelled nonplanar substrate, the slurry on bumps was found to maintain semi-dry condition longer than that at dents. This suggests that the dispersive medium was supplied to bumps from dents. This unique flow was explained as effective drying from the bumps increased surface tension at the bumps to pull up the liquid around.

Dynamic Light Scattering Measurements for Soft Materials on Solid Substrates: Employing Evanescent-wave Illumination and Dark-field Collection with a High Numerical Aperture Microscope Objective.

We developed an instrument that allows us to measure dynamic light scattering from soft materials on solid substrates by avoiding strong background due to the reflection light from substrates. In the instrument, samples on substrates are illuminated by evanescent-light field and the resultant scattered light from the samples is collected with a dark-field optical configuration by employing a high numerical aperture microscope objective. We applied the instrument to measure the dynamic properties of supported lipid bilayers (SLBs), which have been widely utilized in industries as functional materials such as biosensors. From the time course of the scattered light from the SLBs, the power spectrum with the broad peak ranging from 10 to 20 kHz is observed. The use of the microscope objectives enables us to apply the instrument to future light scattering imaging for dynamic properties of soft materials supported on various substrates by combining with conventional microscope systems.

Efficacy of the combined use of a mild foaming cleanser and moisturizer for the care of infant skin.

OBJECTIVE: Despite the application of skin care treatments, many infants have skin problems such as dryness and erythema. We proposed a new combination skin care for infants which consisted of a foaming cleanser with lower surfactant activity and moisturizers that contained pseudo-ceramide. SUBJECTS AND METHODS: A total of 50 infants (age: 3-24 months) with insignificant levels of dry skin were enrolled in this usage trial. The parents washed the infants with the test cleanser while bathing and then applied the moisturizer (lotion or cream) containing pseudo-ceramide. Prior to and following the 4-week usage period, visual evaluation of the skin condition was conducted by a dermatologist, in addition to instrumental analysis. RESULTS: Erythema and papule, accompanied by dryness, were commonly observed at week 0. However, by week 4, these symptoms significantly improved; the condition of none of the subjects deteriorated. The number of infants with lower cutaneous barrier function and higher skin pH decreased. The parents of the infants recognized improvements in the skin symptoms and were appreciative of the test materials. CONCLUSION: The combined usage of the foaming cleanser with lower surfactant activity and a moisturizer containing pseudo-ceramide may be effective in maintaining healthy infant skin and ameliorating the skin symptoms.

A cleanser based on sodium laureth carboxylate and alkyl carboxylates washes facial sebum well but does not induce dry skin.

BACKGROUND: Because excess sebum and/or metabolites of sebum induce skin problems, cleansers that can remove those kinds of sebum are sought after. However, many people, especially who have little facial sebum, are afraid to wash off sebum well because that may induce dry skin. This concern may be caused by the result that cleansers with a high cleansing ability tend to decrease not only facial sebum but also natural moisturizing factors and intercellular lipids that are essential for cutaneous function. Recently, we have developed a new cleanser based on sodium laureth carboxylate and alkyl carboxylates (AEC/soap) that cleans sebum well without penetrating the stratum corneum. OBJECTIVES: This trial was aim to clarify the effects of sebum removal by AEC/soap-based cleanser on the induction of dry skin. METHODS: We designed a controlled single blind parallel trial. Thirty female subjects with mild dry skin were assigned randomly to two groups: one group used AEC/soap-based cleanser while the other group kept using their usual facial cleanser twice a day for 4 weeks in the winter season. RESULTS: Using a colored artificial sebum mixture, it was demonstrated that this cleanser washed sebum well. Following usage of this cleanser, their dry skin improved rather than worsen which was indicated by instrumental analysis and visual assessment. These improvements were recognized by subjects. CONCLUSIONS: These results suggest that AEC/soap-based cleanser washes off facial sebum well, but it has little effect on the induction of dry skin because of less penetration into stratum corneum.

Delivery of an angiogenic gene into ischemic muscle by novel bubble liposomes followed by ultrasound exposure.

PURPOSE: To develop a safe and efficient gene delivery system into skeletal muscle using the combination of Bubble liposomes (BL) and ultrasound (US) exposure, and to assess the feasibility and the effectiveness of BL for angiogenic gene delivery in clinical use. METHODS: A solution of luciferase-expressing plasmid DNA (pDNA) and BL was injected into the tibialis (TA) muscle, and US was immediately applied to the injection site. The transfection efficiency was estimated by a luciferase assay. The ischemic hindlimb was also treated with BL and US-mediated intramuscular gene transfer of bFGF-expressing plasmid DNA. Capillary vessels were assessed using immunostaining. The blood flow was determined using a laser Doppler blood flow meter. RESULTS: Highly efficient gene transfer could be achieved in the muscle transfected with BLs, and US mediated the gene transfer. Capillary vessels were enhanced in the treatment groups with this gene transfer method. The blood flow in the treated groups with this gene transfer method quickly recovered compared to other treatment groups (non-treated, bFGF alone, or bFGF+US). CONCLUSION: The gene transfer system into skeletal muscle using the combination of BL and US exposure could be an effective means for angiogenic gene therapy in limb ischemia.

Synthesis of imino[60]fullerenes using nitriles and trimethylsilylmethyl triflate.

The synthesis of a new class of fullerene derivatives, 1-imino-4-silylmethyl[60]fullerene derivatives, is described. The anion (C(60)R(1-)) of an alkyl- or aryl-adduct of [60]fullerene, C(60)R(1)H (R(1) = CH(2)SiMe(3), CH(2)SiMe(2)Ph, C(6)H(4)-OMe-4, C(6)H(4)-NMe(2)-4, C(6)H(4)-CF(3)-4 and C(6)H(4)-OMe-2), was allowed to react with a nitrilium salt [R(2)CNCH(2)SiMe(3)][OTf] (Tf = SO(2)CF(3)) that was generated in situ by the reaction of Me(3)SiCH(2)OTf and a nitrile solvent R(1)CN (R(2) = Ph and Me). The desired imino[60]fullerene derivative C(60)(R(1)) [C(=NCH(2)SiMe(3))R(2)] was produced in a yield up to 80%. The structure of the product with R(1) = C(6)H(4)-OMe-4 and R(2) = Ph was determined by single-crystal X-ray analysis.

Uniquely shaped double-decker buckyferrocenes--distinct electron donor-acceptor interactions.

Quantum chemical calculations and various photophysical techniques, ranging from steady-state absorption and steady-state as well as time-resolved fluorescence to femtosecond pump-probe experiments, were employed to examine ground- and excited-state interactions in a set of novel double-decker buckyferrocenes (i.e., Fe(2)(C(60)Me(10))Cp(2)): C(2v) and D(5d) isomers. When compared to the individual reference systems, the intimate fullerene/ferrocene contacts reflect appreciable ground-state interactions, namely, substantial redistribution of charge density between the two electron donors (i.e., ferrocenes) and the electron acceptor (i.e., fullerene). Furthermore, an intervalence charge-transfer transition (i.e., ferrocene-ferrocenium interaction) was established, but only in the C(2v) isomer. The first insight into the electron donor-acceptor interactions came from inspecting the fullerene-centered fluorescence. Relative to the reference compounds that contain no ferrocene, which exhibit quantum yields of up to 0.1, and knowing that the fluorescence of the investigated double-decker type conjugates is quenched to 10(-3), transient absorption measurements prove unequivocally the rapid formation of the radical ion-pair states as the dominant products of excited-state deactivation in the double-decker buckyferrocenes. Despite these products having much higher lying radical ion-pair states relative to the corresponding single-decker buckyferrocene, their lifetimes, which vary between 12 and 39 ps, are slightly shorter.

Regioselective synthesis of 1,4-di(organo)[60]fullerenes through DMF-assisted monoaddition of silylmethyl Grignard reagents and subsequent alkylation reaction.

Monoaddition of Grignard reagents, in particular tri(organo)silylmethylmagnesium chlorides, to [60]fullerene took place smoothly in the presence of dimethylformamide to produce (organo)(hydro)[60]fullerenes, C60R(1)H, in good yield (up to 93% isolated yield). The hydrofullerene was then deprotonated to generate the corresponding anion, C60R(-), which was then alkylated to obtain 58pi-electron di(organo)[60]fullerenes, C60R(1)R(2), in good to high yield (up to 93% overall yield). The two-step methodology provides a wide variety of 1,4-di(organo)[60] fullerenes bearing the same or different organic addends on the [60] fullerene core. By changing the addends, one can control the chemical and physical properties of the compounds at the molecular and bulk levels.

A ruthenium bridge in fullerene-ferrocene arrays: synthesis of [Ru(C60Me5)R(CO)2] (R=C6H4Fc, C identical withCFc) and their charge-transfer properties.

New fullerene-ferrocene arrays, [Ru(C(60)Me(5))(C(4)H(6)Fc)(CO)(2)] (Fc=ferrocenyl) and [Ru(C(60)Me(5))(CCFc)(CO)(2)], in which the ruthenium complex functions as a conjugative bridge, were synthesized by the reaction of [Ru(C(60)Me(5))Cl(CO)(2)] with FcC(6)H(4)MgBr and FcCCLi, respectively. These compounds were investigated by electrochemical measurement, single-crystal X-ray structural analysis, and photophysical measurement. Upon photoirradiation, the former compound was converted rapidly into the corresponding triplet state in toluene (tau(singlet)=21 ps), whereas the charge-separated state was predominant in THF (tau(singlet)=10.5 ps; tau(CS)=355 ps). The latter compound, on the other hand, formed the charge-separated state in both toluene and THF (tau(singlet)=3.0 ps; tau(CS)=152 ps). Thus, the structural difference between the phenylene and acetylene bridges in 1 and 2, respectively, was found to change the outcome of the photophysical processes.

Photocurrent-generating properties of organometallic fullerene molecules on an electrode.

Compact, rigid, five-legged fullerene derivatives C60R5Me and M(C60R5)Cp (M = Fe and Ru; R = C6H4COOH, C6H4C6H4COOH, and CH2COOH) were synthesized and arrayed on an indium-tin oxide (ITO) surface. These devices exhibit a respectable quantum yield with photocurrent generation up to 18%, and, more importantly, the direction of the photocurrent can be changed not only by the molecular structure itself but also by changing the geometric configuration of the photoactive acceptor (fullerene) and donor (metal atom) on the ITO surface.

Cariogenic bacteria and caries risk in elderly Japanese aged 80 and older with at least 20 teeth.

OBJECTIVES: To assess caries risk and check the presence of four commonly found oral cariogenic bacteria in "8020" achievers. DESIGN: Initial report based on Japan's newly implemented "8020" campaign, which aims to promote health and awareness in older people. Simply stated, the goal is, at 80 years, to maintain 20 teeth. SETTING: Healthy community-dwelling elderly individuals of Okayama Prefecture, Japan. PARTICIPANTS: One hundred sixty individuals aged 80 and older with 20 of their own natural teeth. MEASUREMENTS: General and oral health conditions, caries risk assessment using the Cariostat method, and polymerase chain reaction (PCR) detection of four oral cariogenic bacteria. RESULTS: The participants had an average of 24.7 teeth, of which 12.1 were sound, 12.2 were treated, and 0.4 were untreated. Based on Cariostat scores, 64.4% had low caries risk. Using PCR, Streptococcus mutans, S. sobrinus, Lactobacillus casei, and L. plantarum were detected in 51.3%, 23.1%, 40%, and 25% of the participants, respectively. S. mutans (P<.001), S. sobrinus (P=.002), L. casei (P<.001), and L. plantarum (P=.001) deoxyribonucleic acid band was detected more in participants with high caries risk scores. CONCLUSION: Participants with low caries risk scores had low prevalence of cariogenic bacteria, 20 or more sound teeth, and fewer missing teeth. Incorporating caries risk assessment, using the Cariostat and PCR analysis, in the "8020" campaign in health systems worldwide will contribute to a better life for the aging society, initiate research interest regarding the program, and improve current health policies.

Total viral genome copies and virus-Ig complexes after infection with influenza virus in the nasal secretions of immunized mice.

The kinetics of infectious virus (p.f.u.), total virus and virus-Ig complex formation following influenza A/PR8 (H1N1) viral infection was examined in the nasal secretions of naive mice and mice immunized with A/PR8, A/Yamagata (H1N1), A/Guizhou (H3N2) and B/Ibaraki influenza viruses. The total number of virus particles and the number within virus-Ig complexes, captured in advance using an anti-mouse Ig-coated plate, were determined on the basis of viral genome copy number using quantitative RT-PCR. The kinetics of infectious and total virus particle formation, the latter of which increased by 10(3)-10(4)-fold above infectious virus numbers, showed that virus elimination from the nasal area was earlier in A/PR8, A/Yamagata and A/Guizhou-X virus-immunized mice, in decreasing order, compared with naive mice. Early virus elimination correlated with the level of A/PR8 virus-reactive antibodies in immunized mice. Virus elimination coincided with the appearance of virus-Ig complexes shortly after infection. This result suggested that antibodies led to the formation of immune complexes in a dose-dependent manner together with a reduction in number of infectious virus particles. The fact that a large number of virus particles was observed in immune complexes for a wide range antibody levels made it difficult to detect slight differences in virus number within the immune complexes, depending on antibody level. These results suggested that the formation of virus-Ig complexes in virus-immunized mice shortly after infection is involved in early virus elimination, which is determined by the strength of protective immunity against challenge viruses.

Iron-catalyzed cross-coupling of primary and secondary alkyl halides with aryl grignard reagents.

An iron-catalyzed cross-coupling reaction of a primary or secondary alkyl halide with an aryl Grignard reagent proceeds under mild conditions to give the corresponding coupling product in quantitative yield.

Iron-catalyzed regio- and stereoselective ring opening of [2.2.1]- and [3.2.1]oxabicyclic alkenes with a Grignard reagent.

[reaction: see text] Arylative and alkenylative ring-opening reactions of a [2.2.1]- or [3.2.1]oxabicyclic alkene with a Grignard reagent take place in the presence of a catalytic amount of iron(III) chloride and a stoichiometric amount of TMEDA to produce a highly substituted 3-cyclohexen-1-ol or 3-cyclohepten-1-ol in good yield with high regio- and stereoselectivity.

Application of an automated specimen search system installed in a transmission electron microscope for the detection of caliciviruses in clinical specimens.

To evaluate the performance of an automated specimen search system in the detection of caliciviruses such as Norwalk-like viruses and Sapporo-like viruses, a suitable negative staining method was developed and the viruses were examined using the system installed in a transmission electron microscope (TEM). Clear images of the viruses were obtained by staining with 2% uranyl acetate at pH 4.0 as compared with 2% phosphotungstic acid staining at any pH. When the image parameter of 30+/-6 nm for the diameter of a single virus-like particle of 2% uranyl-acetate-stained Norwalk-like virus was set on the automated specimen search system, 95% of the virus-like particles that were counted by the conventional TEM technique were detected. The system was used to detect Norwalk-like viruses in five semipurified stool samples in which Norwalk-like viruses had already been detected by reverse transcription-polymerase chain reaction assay and conventional electron microscopy. The positive detection rate for Norwalk-like viruses, which had been counted by the conventional technique, ranged from 56.2 to 77.9% using this system. Our findings indicate that the automated specimen search system installed in a TEM is suitable for the detection of caliciviruses in semipurified stool samples. The system is useful for clinical diagnosis without the need for operator intervention.