Suitable reference genes for relative quantification of miRNA expression in prostate cancer

Real time quantitative PCR (qPCR) is the method of choice for miRNA expression studies. For relative quantification of miRNAs, normalization to proper reference genes is mandatory. Currently, no validated reference genes for miRNA qPCR in prostate cancer are available. In this study, the expression of four putative reference genes (hsa-miR-16, hsa-miR-130b, RNU6-2, SNORD7) was examined with regard to their use as normalizer. After SNORD7 was already shown an inappropriate reference gene in preliminary experiments using total RNA pools, we studied the expression of the putative reference genes in tissue and normal adjacent tissue sample pairs from 76 men with untreated prostate carcinoma collected after radical prostatectomy. hsa-miR-130b and RNU6-2 showed no significantly different expression between the matched malignant and non-malignant tissue samples, whereas hsa-miR-16 was significantly underexpressed in malignant tissue. Softwares geNorm and Normfinder predicted hsa- miR-130b and the geometric mean of hsa-miR-130b and RNU6-2 as the most stable reference genes. Normalization of the four miRNAs hsa-miR-96, hsa- miR-125b, hsa-miR-205, and hsa-miR-375, which were previously shown to be regulated, shows that normalization to hsa-mir-16 can lead to biased results. We recommend using hsa-miR-130b or the geometric mean of hsa-miR-130b and small RNA RNU6-2 for normalization in miRNA expression studies of prostate cancer.     

Lanthanide complexes derived from hexadentate macrocyclic ligand: Synthesis,spectroscopic and thermal investigation

The lanthanide complexes derived from (3,5,13,15-tetramethyl 2,6,12,16,21-22-hexaazatricyclo[15.3.I^1-17I^7-11]cosa-1(21),2,5,7,9,11(22),12,15,17,19-decane) were synthesized. The complexes were found to have general composition [Ln(L)X₂·H₂O]X, where Ln = La³⁺, Ce³⁺, Nd³⁺, Sm³⁺ and Eu³⁺ and X = NO₃^? and Cl^?. The ligand was characterized by elemental analyses, IR, Mass, and ¹H NMR spectral studies. All the complexes were characterized by elemental analyses, molar conductance measurements, magnetic susceptibility measurements, IR, Mass, electronic spectral techniques and thermal studies. The ligand acts as a hexadentate and coordinates through four nitrogen atoms of azomethine groups and two nitrogen of pyridine ring. The lanthanum complexes are diamagnetic while the other Ln(III) complexes are paramagnetic. The spectral parameters i.e. nephelauxetic ratio (β), covalency factor (b^1/2), Sinha parameter (δ%) and covalency angular overlap parameter (η) have been calculated from absorption spectra of Nd(III) and Sm(III) complexes. These parameters suggest the metal–ligand covalent bonding. In the present study, the complexes were found to have coordination number nine.     

Trimethylsilyldiazomethane (TMSD) as a new derivatization reagent for trace analysis of selected non-steroidal anti-inflammatory drugs (NSAIDs) by gas chromatography methods

Non-steroidal anti-inflammatory drugs (NSAIDs) are among the most common groups of pharmaceuticals detected in environmental matrices. Although several derivatization procedures have been employed in the gas chromatographic analysis of NSAIDs, the application of trimethylsilyldiazomethane has never yet been reported. This work has studied the derivatization of widely used NSAIDs (ibuprofen, ketoprofen and naproxen) by trimethylsilyldiazomethane. Special emphasis was placed on the influence of temperature and reaction time on the reaction yield, and on the determination of the instrumental detection limit. The results are compared with those obtained by methylation using boron trifluoride methanol solution, and by silylation with a mixture of N,O-bis(trimethylsilyl)trifluoroacetamide and trimethylchlorosilane (99:1, v/v) and with N-methyl-N-[tert-butyldimethylsilyl]trifluoroacetamide. The derivatization of ibuprofen, ketoprofen and naproxen by trimethylsilyldiazomethane was shown to be simple, fast, efficient, and suitable for trace analysis (the respective instrumental detection limits for ibuprofen naproxen, and ketoprofen were 2, 4, and 4 ng). Trimethylsilyldiazomethane can be used as an alternative reagent for determining acidic drugs in environmental matrices.     

The 1,4-diazabutadiene/1,2-enediamido non-innocent ligand system in the formation of iridaheteroaromatic compounds: Spectroelectrochemistry and electronic structure

Oxidation of the unambiguously characterized iridium(III)-enediamido complex IrCp∗(RNCHCHNR), R = 2,6-dimethylphenyl, with six cyclically arranged π electrons was investigated using EPR and UV-vis spectroelectrochemistry. In contrast to a corresponding iminocatecholato system reported recently by Rauchfuss et al. [27] the two one-electron oxidation steps are not completely reversible, depending on the solvent. We attribute the electrochemical behavior observed in weakly coordinating dichloromethane and propylene carbonate solvents to an enhanced propensity for ligand addition: while neutral IrCp∗(RNCHCHNR) remains coordinatively unsaturated with the strongly σ and π donating enediamido(2−) ligand mitigating the electron deficit, the oxidation to the less donating radical anion ligand (RNCHCHNR)^- or even to neutral 1,4-diazabutadiene is considered to induce a strong tendency for quasi-hexacoordination in [IrCp∗(L)(RNCHCHNR)], L = solvent, halide, substrate. The presence of excess chloride thus leads to formation of the precursor complex ion [IrCp∗ClRNCHCHNR)]⁺ after oxidation. EPR spectroscopy of the one-electron oxidation intermediate [IrCp∗(RNCHCHNR)]⁺ was successful only for a frozen solution in propylene carbonate/0.1 M Bu₄NPF₆ which revealed an axial signal with sizeable g anisotropy. DFT calculation results for [IrCp∗(RNCHCHNR)]ⁿ, n = 0, +, 2+ confirm the available structural and spectroelectrochemical data (UV-vis, EPR).     

Structural, spectral, and electrochemical investigations of para-tolyl-substituted oligogermanes

The synthesis of four new oligogermanes containing para-tolyl-substituents has been achieved via the hydrogermolysis reaction, including the digermane Tol₃GeGePh₃, the trigermanes Tol₃GeGePh₂GeTol₃ and Tol₃GeGeTol₂GeTol₃, and the tetragermane Tol₃GeGePh₂GePh₂GeTol₃ (Tol = p-CH₃C₆H₄). These four oligogermanes have been structurally characterized and their structures have been compared with those of their per-phenyl-substituted analogs. The digermane Tol₃GeGePh₃ exhibits an unusually short Ge-Ge bond distance of 2.408(1) Å. The four para-tolyl-substituted oligogermanes have also been characterized by UV/visible spectroscopy and cyclic voltammetry. The expected red shift in the absorbance maximum with increasing catenation was observed for this series of compounds. Their cyclic voltammograms each contain n − 1 irreversible oxidation waves (n = the number of Ge atoms), which is atypical since oligogermanes generally exhibit only one irreversible oxidation wave regardless of the degree of catenation.     

Secondary electron yield measurements of carbon covered multilayer optics

Carbon contamination on extreme ultraviolet (EUV) optics has been observed in EUV lithography. In this paper, we performed in situ monitoring of the build-up and removal of carbon contamination on Mo/Si EUV multilayers by measuring the secondary electron yield as a function of primary electron energy. An electron beam with an energy of 2 keV was used to simulate the EUV radiation induced carbon contamination. For a clean EUV multilayer, the maximum secondary electron yield is about 1.5 electrons per primary electron at a primary electron energy of 467 eV. The maximum yield reduced to about 1.05 at a primary electron energy of 322 eV when the surface was covered by a non-uniform carbon layer with a maximum thickness of 7.7 nm. By analyzing the change in the maximum secondary electron yield with the final carbon layer thickness, the limit of detection was estimated to be less than 0.1 nm.     

Selected applications of perturbed angular correlation of γ-rays (PAC) spectroscopy in biochemistry

PAC spectroscopy was first applied in biochemistry more than 40 years ago in a study of serum albumin (Leipert et al., Nature 220:907–909, 1968). Over the following decades a number of such applications have appeared in the literature, demonstrating that PAC spectroscopy is a useful tool in the study of biomolecules. Selected prototypical examples with ^111mCd, ¹¹¹Ag, and ^199mHg are presented in this work with a particular focus on the biological role of metal ions in catalysis, protein structure and function, protein–protein interaction in biochemical reaction paths, in vivo binding of mercury ions to barley, and the use of de novo designed proteins to systematically explore the interaction of proteins and metal ions.     

Effect of Cr substitution on the superconducting and magnetic properties of RuSr2Eu1.5Ce0.5Cu2O10−δ

In this paper we investigate the properties of polycrystalline series of Ru_1?xCr_xSr₂Eu_1.5Ce_0.5Cu₂O_10?δ (0.0 ? x ? 0.40) by resistivity, XRD and dc magnetization measurements. EuRu-1222 is a reported magneto superconductor with Ru spins magnetic ordering at temperatures near 100 K and superconductivity occurs in Cu–O₂ planes below T_c ? 40 K. The exact nature of Ru spins magnetic ordering is still being debated and no conclusion has been reached yet. In this work, we found the superconducting transition temperature T_c = 20 K from resistivity and dc magnetization measurements for pristine sample. DC magnetization measurements exhibited ferromagnetic like transition for all samples.     

Superconductivity in Pb-1212–Cu1−xPbxSr2Y0.6Ca0.4Cu2O7 (x = 0.5–0.9)

We report synthesis and superconductivity of Pb-1212–Cu_1?xPb_xSr₂Y_0.6Ca_0.4Cu₂O₇ (x = 0.5–0.9) compounds. These compounds were synthesized through solid-state reaction route with optimized sintering temperatures and conditions. In particular, one needs to employ reducing atmosphere conditions to achieve superconductivity in higher Pb content samples. The X-ray diffraction (XRD) patterns reveals that all the compounds are crystallized in space group P4/mmm RE-123 structure. Superconductivity at 56 K (onset) is achieved for Pb content as high as 90%. Our study reveals that superconductivity and structure stabilization in Pb-based are more critical to synthesizing conditions than other cuprates. It is concluded that superconductivity can be introduced in Pb-1212 compounds by synthesizing the same in reducing atmosphere and thus the Pb in lower (<+4) valence state. This ensures the replacement of Cu–O_x chains of RE-123 by Pb–O_x sheets acting as charge reservoir carrier donating blocks.     

Novel Fluorophores as Building Blocks for Optical Probes for In Vivo Near Infrared Fluorescence (NIRF) Imaging

Aiming at the identification of new fluorescent reporters for targeted optical probes, we assessed the application-relevant features of a novel asymmetric cyanine, DY-681, in comparison to the only clinically approved dye indocyanine green (ICG), the golden imaging standard Cy5.5, and the asymmetric cyanine DY-676 successfully exploited by us for the design of different contrast agents. This comparison included the analysis of the spectroscopic properties of the free fluorophores and their thermal stability in aqueous solution as well as their cytotoxic potential. In addition, the absorption and emission features of IgG-conjugated DY-681 were examined. The trimethine DY-681 exhibited spectral features closely resembling that of the pentamethine Cy5.5. Its high thermal stability in phosphate buffer saline (PBS) solution in conjunction with its low cytotoxicity, reaching similar values as determined for Cy5.5 and DY-676, renders this dye more attractive as ICG and, due to its improved fluorescence quantum yield in PBS, also superior to DY-676. Although in PBS, Cy5.5 was still more fluorescent, the fluorescence quantum yields (Φ _f) of DY-681 and Cy5.5 in PBS containing 5 mass-% bovine serum albumin (BSA) were comparable. Labeling experiments with DY-681 and the model antibody IgG revealed promisingly high Φ _f values of the bioconjugated dye.