Thin Film Co3O4/TiO2 Heterojunction Solar Cells

Co₃O₄ is investigated as a light absorber for all‐oxide thin‐film photovoltaic cells because of its nearly ideal optical bandgap of around 1.5 eV. Thin film TiO₂/Co₃O₄ heterojunctions are produced by spray pyrolysis of TiO₂ as a window layer, followed by pulsed laser deposition of Co₃O₄ as a light absorbing layer. The photovoltaic performance is investigated as a function of the Co₃O₄ deposition temperature and a direct correlation is found. The deposition temperature seems to affect both the crystallinity and the morphology of the absorber, which affects device performance. A maximum power of 22.7 μW cm^?2 is obtained at the highest deposition temperature (600 °C) with an open circuit photovoltage of 430 mV and a short circuit photocurrent density of 0.2 mA cm^?2. Performing deposition at 600 °C instead of room temperature improves power by an order of magnitude and reduces the tail states (Urbach edge energy). These phenomena can be explained by larger grains that grows at high temperature, as opposed to many nucleation events that occur at lower temperature.     

Novel Histone Deacetylase Class IIa Selective Substrate Radiotracers for PET Imaging of Epigenetic Regulation in the Brain

Histone deacetylases (HDAC’s) became increasingly important targets for therapy of various diseases, resulting in a pressing need to develop HDAC class- and isoform-selective inhibitors. Class IIa deacetylases possess only minimal deacetylase activity against acetylated histones, but have several other client proteins as substrates through which they participate in epigenetic regulation. Herein, we report the radiosyntheses of the second generation of HDAC class IIa–specific radiotracers: 6-(di-fluoroacetamido)-1-hexanoicanilide (DFAHA) and 6-(tri-fluoroacetamido)-1-hexanoicanilide ([¹⁸F]-TFAHA). The selectivity of these radiotracer substrates to HDAC class IIa enzymes was assessed in vitro, in a panel of recombinant HDACs, and in vivo using PET/CT imaging in rats. [¹⁸F]TFAHA showed significantly higher selectivity for HDAC class IIa enzymes, as compared to [¹⁸F]DFAHA and previously reported [¹⁸F]FAHA. PET imaging with [¹⁸F]TFAHA can be used to visualize and quantify spatial distribution and magnitude of HDAC class IIa expression-activity in different organs and tissues in vivo. Furthermore, PET imaging with [¹⁸F]TFAHA may advance the understanding of HDACs class IIa mediated epigenetic regulation of normal and pathophysiological processes, and facilitate the development of novel HDAC class IIa-specific inhibitors for therapy of different diseases.     

Right time - right location - right move: TRPs find motors for common functions

TRP channels are localized at specialized sub-cellular compartments like filopodial tips, ciliary structures, growth cones and spines that have importance in the context of several sensory functions. Several motor proteins largely regulate these localizations. Recent studies indicate that both physical and genetic interactions exist between TRP channels with actin and microtubule-based motor proteins. These two groups of proteins share specialized and fine regulation underlying physiological functions. Indeed, mutations causing loss of these interactions and regulations result in development of pathophysiological disorders and syndromes. In this review we analyze the recent progress made in cell-biological, biochemical, electrophysiological and genetic studies and summarize the multi-dimensional crosstalk between TRP channels with different motor proteins.     

Characterization of an unusual folding pattern in a catalytically active guanine quadruplex structure

In the presence of certain metal ions, DNA and RNA can form guanine quadruplex structures, which have been proposed to play a functional role in a variety of biological processes. An 18-nucleotide DNA oligomer, PS2.M, d(GTG3TAG3CG3T2G2), was previously reported to bind hemin and the resulting complex exhibited peroxidase activity. It was proposed that PS2.M folds unimolecularly into an antiparallel quadruplex with unusual, single-base loops and terminal guanines positioned in adjacent quartets. Here we describe structural and stability properties of PS2.M alone in different buffers and metal ions, using gel electrophoresis, circular dichroism (CD), ultraviolet (UV)-visible spectroscopies, and one-dimensional 1H nuclear magnetic resonance (NMR). Native gel behavior of PS2.M in the presence of either Na+ or Pb2+ suggests the formation of unimolecular structures but, in the presence of K+, both unimolecular and multistranded structures are observed. In the presence of Pb2+ ions, PS2.M forms a unimolecular quadruplex containing three guanine quartets. CD titrations reveal that binding of Pb2+ ions to PS2.M is stoichiometric, and a single lead cation suffices to fully fold PS2.M. The PS2.M-Na+ system also forms a similar unimolecular quadruplex. In the presence of K+, the PS2.M-K+ system forms mixed species. With increasing time and PS2.M concentration, the contribution of unimolecular species decreases while that of multimolecular species increases, and this behavior is independent of buffer media. These results suggest that the catalytically active form, studied in the presence of K+, may be a parallel, multistranded quadruplex rather than an antiparallel, unimolecular quadruplex.     

Suitability of cryoprotectants and impregnation protocols for embryos of Japanese whiting Sillago japonica

The purpose of this study was to examine the suitability of cryoprotectant agent (CPA) impregnation protocols for the embryos of Japanese whiting (Sillago japonica), a small-sized, easy-to-rear, and prolific marine fish which may constitute a suitable experimental material for the development of cryopreservation methods for fish embryos. Our immediate goals were to assess the toxicity and permeability of various CPAs to whiting embryos of different developmental stages. Exposure of gastrula, somites, tail elongation, and pre-hatching embryos to 10%, 15%, and 20% solutions of propylene glycol (PG), methanol (MeOH), dimethyl sulfoxide (Me2SO), dimethylformamide (DFA), ethylene glycol (EG), and glycerol (Gly) in artificial sea water (ASW; 33 psu) for 20 min revealed that CPA toxicity for whiting embryos increased in the order of PG相似文献   

Does "ichthyosis uteri" have malignant potential? : A case report of squamous cell carcinoma of endometrium associated with extensive ichthyosis uteri

This short report discusses a case of solitary colonic polypoid ganglioneuroma associated with melanosis coli in a woman with no systemic manifestations. To our knowledge this is the first ganglioneuroma reported in the literature in association with melanosis coli. The nature and significance of this event remains unclear, although this may be coincidental due to the laxative intake. Further investigation is necessary to clarify this point. The interest of this case lies moreover in the rarity of this entity and its endoscopic and histologic resemblance to sessile polyps frequent in the clinical practice.     

Triple Surface Plasmon Resonances in Zn Nanoparticles in Silica

Theoretical calculations of optical absorption (OA) spectra of Zn nanoparticles (NPs) in silica glass, using a simple model, have been resulted in appearance of three OA bands, all of which are found to blueshift with decrease in NP radius due to quantum confinement effects of free electrons. The intensities of the OA bands are seen to increase with increase in incident light energy. Importantly, all the three OA bands have been found to satisfy, accurately, the surface plasmon resonance (SPR) condition. All these observations clearly indicate that the observed OA bands are originated from the SPR absorptions in Zn NPs, but not due to inter-band absorption.     

Effect of age on lipid peroxides, lipofuscin and ascorbic acid contents of the lungs of male garden lizard

Oxidative damage was assessed through the estimation of lipid peroxides (LP) in the lungs of an ageing short-lived species of reptile, Calotes versicolor, commonly known as the garden lizard. Attempts were also made to trace its relationship with the age pigment, lipofuscin and the antioxidant ascorbic acid. While LP increased with advancing age the contents of both lipofuscin and ascorbic acid did not show appreciable change during maturation ( < 1-1 year old) but declined during senescence phase (1 to 2-4 year old). While the pattern of age associated changes in LP and ascorbic acid indicate similarity with the pattern observed in most of the mammals, the reduction of lipofuscin in older lizards is a significant departure from the common trend.