Preparation of periodic mesoporous organosilica with large mesopores using silica colloidal crystals as templates.

Organosiloxane-based mesoporous materials with periodically ordered pores (periodic mesoporous organosilica, PMO) have many applications due to their various organic functions, high surface areas, and large pore volumes. Conventional methods using surfactant templates (soft templates) are limited in terms of the diversity of organosilane precursors and precise control over the pore size in a relatively large mesopore region (10-50 nm). This paper demonstrates the preparation of PMOs with precisely controlled pore sizes (>10 nm in diameter) and various organosiloxane frameworks, using colloidal crystals of monodisperse silica nanospheres as a template. An inverse opal structure with interconnected spherical mesopores was obtained through polycondensation of hydrolyzed organoalkoxysilanes [(EtO)3Si-R-Si(OEt)3, R = C2H4, CH[double bond, length as m-dash]CH, and C6H4; PhSi(OEt)3], within the voids of silica colloidal crystals, followed by the preferential dissolution of silica under well-controlled basic conditions. The pore size varied depending on the size of the silica nanospheres. The versatility of this method will allow for the wide tuning of the physical and chemical properties of organosiloxane-based mesoporous materials.

Synthesis of Polycyclic and Cage Siloxanes by Hydrolysis and Intramolecular Condensation of Alkoxysilylated Cyclosiloxanes.

The controlled synthesis of oligosiloxanes with well-defined structures is important for the bottom-up design of siloxane-based nanomaterials. This work reports the synthesis of various polycyclic and cage siloxanes by the hydrolysis and intramolecular condensation of monocyclic tetra- and hexasiloxanes functionalized with various alkoxysilyl groups. An investigation of monoalkoxysilylated cyclosiloxanes revealed that intramolecular condensation occurred preferentially between adjacent alkoxysilyl groups to form new tetrasiloxane rings. The study of dialkoxy- and trialkoxysilylated cyclotetrasiloxanes revealed multistep intramolecular condensation reactions to form cubic octasiloxanes in relatively high yields. Unlike conventional methods starting from organosilane monomers, intramolecular condensation enables the introduction of different organic substituents in controlled arrangements. So-called Janus cubes have been successfully obtained, that is, Ph4 R4 Si8 O12 , in which R=Me, OSiMe3 , and OSiMe2 Vi (Vi=vinyl). These findings will enable the creation of siloxane-based materials with diverse functions.

Changes in brain metabolites related to stress resilience: Metabolomic analysis of the hippocampus in a rat model of depression.

The ability to cope successfully with stress is known as 'resilience', and those with resilience are not prone to developing depression. One preclinical animal model for depression is the chronic mild stress (CMS) model. There are CMS-resilient (do not manifest anhedonia) and CMS-susceptible (manifest anhedonia) rats. This study aimed to investigate the differences in the profiles of hippocampal metabolites between susceptible and resilient rats, and to identify a biomarker that can distinguish the two. We divided stress-loaded rats into susceptible and resilient types based on their sucrose preference values. We then conducted brain-derived neurotrophic factor (BDNF) quantification and metabolomic analysis in the hippocampus. Compared to the controls, no significant differences were observed in the hippocampal BDNF levels of susceptible and resilient rats. However, the control rats were clearly distinguishable from the susceptible rats in terms of their brain metabolite profiles; the control rats were difficult to distinguish from the resilient rats. CMS model rats showed an increase in the levels of N-acetylaspartate and glutamate, and a decrease in the levels of aspartate and γ-aminobutyric acid in the hippocampus. Of the 12 metabolites measured in the present study, N-acetylaspartate was the only one that could differentiate the three types (control, susceptible, and resilient) of rats. Thus, brain metabolomic analyses can not only distinguish CMS model rats from control rats, but also indicate stress susceptibility. The variation in the levels of N-acetylaspartate in the hippocampus of control, resilient, and susceptible rats demonstrated that it could be a biomarker for stress susceptibility.

Drug delivery and transmission of lidocaine using iontophoresis in combination with direct and alternating currents.

The present study investigates how effectively lidocaine ions are transported across a cellophane membrane through the application of either a direct current (DC) or alternating current (AC). The cellophane membrane was set on a parallelplate- type acrylic cell with platinum electrodes at both ends, filled with a donor cell of a 1 % aqueous solution of lidocaine and a receptor cell with distilled water. Lidocaine concentrations were measured for 60 min while the following voltages were applied, with changes every 10 min: 3 V DC and 7.5 V sine wave AC; frequency at 1 kHz. As a result, lidocaine concentrations in the receptor cell increased in a time-dependent manner. Significant increases in lidocaine concentrations were observed in groups where the voltage combination consisted of DC 30 min/AC 30 min, DC 50 min/AC 10 min, DC 60 min and AC 10 min/DC 50 min, compared with the passive diffusion group or in groups where voltage application was performed for 20, 30 , 40, 50 and 60 min. Significant increases were also observed in groups where the voltage combination consisted of A C 6 0 min, D C 10 min/AC 5 0 min, AC 3 0 min/ DC 30 min and AC 50 min/DC 10 min, compared with the passive diffusion group or in groups where voltage application was performed for 40, 50 and 60 min. These results suggest that lidocaine was delivered more rapidly with DC than with AC, and that its ions are transported faster when voltage is switched from DC to AC than from AC to DC, which is presumably due to the contribution of electrorepulsion by DC voltage application and the vibration energy infiltration mechanism owning to AC. Iontophoresis in combination with DC and AC was found to enable highly efficient drug delivery that shares the benefits of both forms of current application.

Asian origin and rapid global spread of the destructive dry rot fungus Serpula lacrymans.

The dry rot fungus Serpula lacrymans (Basidiomycota) is the most damaging destroyer of wood construction materials in temperate regions. While being a widespread aggressive indoor biodeterioration agent, it is only found in a few natural environments. The geographical source of spread and colonization by this fungus in human environments is thus somewhat of an enigma. Employing genetic markers (amplified fragment length polymorphisms, DNA sequences and microsatellites) on a worldwide sample of specimens, we show that the dry rot fungus is divided into two main lineages; one nonaggressive residing naturally in North America and Asia (var. shastensis), and another aggressive lineage including specimens from all continents, both from natural environments and buildings (var. lacrymans). Our genetic analyses indicate that the two lineages represent well-differentiated cryptic species. Genetic analyses pinpoint mainland Asia as the origin of the aggressive form var. lacrymans. A few aggressive genotypes have migrated worldwide from Asia to Europe, North and South America and Oceania followed by local population expansions. The very low genetic variation in the founder populations indicate that they have established through recent founder events, for example by infected wood materials transported over land or sea. A separate colonization has happened from mainland Asia to Japan. Our data also indicate that independent immigration events have happened to Oceania from different continents followed by admixture.