Whole-body distribution of <Superscript>14</Superscript>C-labeled silica nanoparticles and submicron particles after intravenous injection into Mice

We analyzed the whole-body distribution of ¹⁴C–ADP-labeled silica nanoparticles (¹⁴C–ADP–SiO₂ nanoparticles) and submicron particles (¹⁴C–ADP–SiO₂ submicron particles) after intravenous injection into ICR mice. The ¹⁴C–ADP–SiO₂ nanoparticles and submicron particles were synthesized before the injection and the particle size was 19.6 and 130 nm, respectively. Similarly, the shape was spherical and the crystallinity was amorphous. After the synthesis, we injected mice with the ¹⁴C–ADP–SiO₂ nanoparticles or the ¹⁴C–ADP–SiO₂ submicron particles and dissected tissues after 1, 2, 4, 8 and 24 h. The radioactivity in the tissues was measured with a liquid scintillation counter. As a result, the retention percentage in bone, skin, lymph nodes, and the digestive mixture was at least twofold higher in the ¹⁴C–ADP–SiO₂ nanoparticles-exposed mice, whereas the retention percentage in the kidney was statistically higher in the ¹⁴C–ADP–SiO₂ submicron particles-exposed mice. Both types of ¹⁴C–ADP–SiO₂ particles mainly translocated to the muscle, bone, skin, and liver, but hardly translocated to the brain and olfactory bulb. Furthermore, the ¹⁴C–ADP–SiO₂ nanoparticles had a higher retention percentage (62.4 %) in the entire body at 24-h post-injection than did the ¹⁴C–ADP–SiO₂ submicron particles (50.7 %). Therefore, we suggested that the ¹⁴C–ADP–SiO₂ nanoparticles might be more likely than the ¹⁴C–ADP–SiO₂ submicron particles to be retained in the body, and consequently they might be gradually accumulated by chronic exposure.     

Synthesis of functionalized hydroxy-thiophene motifs as amido- and sulfonamido-phenol bioisosteres

Novel highly substituted hydroxy thiophene motifs were designed and synthesized as viable amido phenol and sulfonamido phenol bioisosteres. Hydroxy group-directed regioselective bromination and palladium-catalyzed amination of thienyl bromide via Buckwald protocol are the key elements of the synthetic approach. The hydroxy thiophene-containing compounds displayed good binding inhibitions.     

Intrauterine devices and uterine peristalsis: evaluation with MRI

Intrauterine devices (IUDs) have been viewed as an effective form of contraception. However, the mechanism by which IUDs disturb fertility remains controversial. This study aimed to evaluate the effects of IUDs on uterine contractility using cine MR. Eleven healthy female volunteers of reproductive age bearing IUDs and 12 women not bearing IUDs were evaluated during the periovulatory phase. MR images were obtained with a 1.5-T magnet, acquiring 60 serial images every 3 s via half-Fourier acquisition single-shot turbo spin echo to be displayed on cine mode. Assessments were based on (a) the presence of peristaltic waves, (b) the frequency and direction of peristaltic waves and (c) the extent of peristaltic waves. Static images were evaluated for thickness of the junctional zone (JZ) and myometrium. A fundo-cervical (FC)-directed peristaltic wave was identified in 4 of 11 IUD-bearing subjects and in only 1 of 12 subjects from the control group. FC waves extended through more than half of the thickness of the myometrium. Peristaltic frequency in IUD users (5.0/3 min) was less than that of the control group (6.5/3 min). The JZ and myometrium were significantly thicker in IUD users. FC-directed waves were more often observed in IUD-bearing subjects, which might explain the inhibition of active sperm transport.     

Newly developed chemical probes and nano-devices for cellular analysis.

A cellular analyzing system including a "real-time cellular imaging system" and a "comprehensive analyzing system for cellular responses" was developed. A "real-time cellular imaging system" is a system used to measure real-time imaging of multiple phenomena of a single cell with high special and temporal resolutions for the purpose to understand the pathology and physiology in a single cell and realize to single cell level diagnosis. A "real-time cellular imaging system" includes multi-probe imaging with AFM (atomic force microscopy), optical and SECM (scanning electrochemical microscopy) modes, which provides us with topological information and biochemical reactions at the local area of the interior and exterior of a cell. Scanning electrochemical/optical microscopy was applied to image PC12 cells. On the other hand, cells respond to their specific substances via their ligands. Therefore, the comprehensive analysis of protein-protein interaction is the important issue to determine the functions of cells. For this purpose, a "comprehensive analysis system for cellular responses" was developed. This system is based on SPR (surface plasmon resonance) and MS (mass spectrometry) using a nano-fabricated substrate. The interaction between IL-1 beta and anti-IL-1 beta antibodies was detected.     

The first total synthesis and reassignment of the relative stereochemistry of 16-hydroxy-16,22-dihydroapparicine

We report the first total synthesis and reassignment of the relative stereochemistry of naturally occurring 16-hydroxy-16,22-dihydroapparicine. Our novel route proceeds by a cascade reaction to efficiently construct a 1-azabicyclo[4.2.2]decane core, along with two stereocenters (C-15 and C-16). The C-16 quaternary carbon was constructed through stereospecific 1,2-addition using an indole nucleophile to an aldehyde or a methylketone. The stereospecific synthesis of two diastereomers of the target product has revealed the true relative stereochemistry of the natural compound.     

Micellar size, shape and counterion binding of N-(1,1-Dihydroperfluoroalkyl)-N,N,N-trimethylammonium chloride in aqueous solutions

Under the limiting conditions, light-scattering method was applied to determine the size and shape of fluorinated micellar structure in aqueous solution. The hydrodynamic radii (r _h) of molecular aggregates were investigated for four amphiphiles with different alkyl chain length: N-(1,1-dihydroperfluorooctyl)-, N-(1,1-dihydroperfluorodecyl)-, N-(1,1-dihydroperfluorododecyl)-, and N-(1,1-dihydroperfluorotetradecyl)-N,N,N-trimethylammonium chloride by dynamic light scattering. Size of these molecular aggregates drastically increased with increasing carbon number of alkyl chain and the concentration. For example, the r _h values were 35, 63, 95, and 136 nm for C8, C10, C12, and C14 of the alkyl chain, respectively, at the concentration of 15× critical micelle concentration (cmc) and at 298.2 K. On the other hand, the mean radius of gyration (r _g) and the apparent molecular weight of these aggregates were measured using static light scattering. The r _g value was found to be 34, 73, and 125 nm for C8, C10, and C12 of the alkyl chain, respectively, at the same condition above. The shape of aggregate was analyzed by comparing the dependence of r _g/r _h with theoretical values. The plots of r _g against r _h almost corresponded with the theoretical line of oblate ellipsoid (disk-like), and which was also expected from calculation of packing parameter value. The measurement for chloride ion activity was made by a chloride ion selective electrode to know the degree of counterion binding to the aggregates, whose values increased with increasing total concentration and with the carbon number of alkyl chain. The chloride ion binding to aggregates neutralized cationic head groups under their electrostatic repulsion and partly promoted the growth of aggregates.     

Synthesis of photocatalytic active fibrous titania by the solvothermal reactions

Abstract

Fibrous titania was synthesized by the solvothermal reactions of H₁Ti₄O₉ nH₂in different media. H₂Ti₄O₉·nH₂O transformed in steps to H₂Ti₈O₁₇, monoclinic TiO_z, anatase and rutile. The phase transformation temperature and microstructure of the products changed significantly depending on the heating environment. The critical temperature at which anatase appeared in liquid media was much lower than that in air. The titania fibers consisted of nanocrystals of TiO₂. The crystallite size and crystallinity of titania decreased with decreasing the dielectric constant of the reaction medium. Consequently, the photocatalytic activity of titania changed with heat treatment media in the following sequence: ethanol, methanol > water > air, i.e., fibrous titania possessing excellent photocatalytic activity could be obtained by the solvothermal reactions using alcohol such as methanol and ethanol. Titania powders crystallized by the solvothermal reaction in methanol also possessed excellent thermal stability.     

Asymmetric Total Synthesis of Indole Alkaloids Containing an Indoline Spiroaminal Framework

The total synthesis of the indole alkaloids, neoxaline, oxaline and meleagrin A, all containing a unique indoline spiroaminal framework, was accomplished through the stereoselective introduction of a reverse prenyl group to the congested benzylic carbon of furoindoline, a two‐pot transformation of indoline (containing three nitrogen atoms at appropriate positions) to the featured indoline spiroaminal framework, and elimination of carbonate assisted by the adjacent imidazole moiety to construct the (E)‐dehydrohistidine. The absolute stereochemistry of neoxaline was elucidated through our total synthesis. In addition, we evaluated the bioactivity, especially the anti‐infectious properties, of neoxaline and oxaline, and of some synthetic intermediates.     

Sooner and later waiting time problems in a two-state Markov chain

LetX ₁,X ₂,... be a time-homogeneous {0, 1}-valued Markov chain. LetF ₀ be the event thatl runs of 0 of lengthr occur and letF ₁ be the event thatm runs of 1 of lengthk occur in the sequenceX ₁,X ₂, ... We obtained the recurrence relations of the probability generating functions of the distributions of the waiting time for the sooner and later occurring events betweenF ₀ andF ₁ by the non-overlapping way of counting and overlapping way of counting. We also obtained the recurrence relations of the probability generating functions of the distributions of the sooner and later waiting time by the non-overlapping way of counting of 0-runs of lengthr or more and 1-runs of lengthk or more.