Electron microscopic visualization of tRNA genes with ferritin-avidin: biotin labels

A method is described for indirect electron microscopic visualization and mapping of tRNA and other short transcripts hybridized to DNA. This method depends upon the attachment of the electron-dense protein ferritin to the RNA, the binding being mediated by the remarkably strong association of the egg white protein avidin with biotin. Biotin is covalently attached to the 3' end of tRNA using an NH2 (CH2) 5NH2 bridge. The tRNA-biotin adduct is hybridized to complementcrry DNA sequences present in a single stranded nonhomology loop of a DNA:DNA heteroduplex. Avidin, covalently crosslinked to ferritin is mixed with the heteroduplex and becomes bound to the hybridized tRNA-biotin. Observation of the DNA:RNA-biotin:avidin-ferritin complex by electron microsdopy specifically and accurately reveals the position of the tRNA gene, with a frequency of labeling of approximately 50%

Temporal Variability of Urinary Phthalate Metabolite Levels in Men of Reproductive Age

Phthalates are a family of multifunctional chemicals widely used in personal care and other consumer products. The ubiquitous use of phthalates results in human exposure through multiple sources and routes, including dietary ingestion, dermal absorption, inhalation, and parenteral exposure from medical devices containing phthalates. We explored the temporal variability over 3 months in urinary phthalate metabolite levels among 11 men who collected up to nine urine samples each during this time period. Eight phthalate metabolites were measured by solid-phase extraction–high-performance liquid chromatography–tandem mass spectrometry. Statistical analyses were performed to determine the between- and within-subject variance apportionment, and the sensitivity and specificity of a single urine sample to classify a subject’s 3-month average exposure. Five of the eight phthalates were frequently detected. Monoethyl phthalate (MEP) was detected in 100% of samples; monobutyl phthalate, monobenzyl phthalate, mono-2-ethylhexyl phthalate (MEHP), and monomethyl phthalate were detected in > 90% of samples. Although we found both substantial day-to-day and month-to-month variability in each individual’s urinary phthalate metabolite levels, a single urine sample was moderately predictive of each subject’s exposure over 3 months. The sensitivities ranged from 0.56 to 0.74. Both the degree of between- and within-subject variance and the predictive ability of a single urine sample differed among phthalate metabolites. In particular, a single urine sample was most predictive for MEP and least predictive for MEHP. These results suggest that the most efficient exposure assessment strategy for a particular study may depend on the phthalates of interest

First US Performance Measurements of Next Generation 3D USCT 2.5 Transducers

The KIT’s 3D Ultrasound Computer Tomography (USCT) II system has a multistatic setup of 2041 ultrasound transducers with approx. 1.5 MHz 6dB bandwidth and 36◦ 3 dB opening angle for 2.5 MHz. To increase the region of interest for a next USCT generation, the opening angle should be increased to approx. 60◦ and the bandwidth doubled. To increase the opening angle the size of the transducer elements was decreased to approximately half the size. A circular aperture was chosen for homogenicity of the radiation pattern in 3D. The transducer design utilizes piezo-fibres by the established Fraunhofer IMT piezo-fibre composite technology. The fibres were fabricated from PZT powder using the polysulfone spinning process. 17 fibres were positioned with a mechanical mask and filled with a matrix of epoxy. From this rod piezo composite discs were sawed and polarized. Electrodes were generated by silver-filled epoxy adhesive on the top and bottom side. Materials for acoustic backing is a Tungsten-Polyurethane composite and for acoustic matching ia aluminium oxide composite material (TMM4). Ultrasound characteristics were evaluated quantitatively with a Onda HNC-400 hydrophone in a 3-axis water tank for a randomly selected sample transducer (see Fig. a.)). Characteristics evaluated were the pressure field as function over frequency and angle in the far-field (see Fig. b.)), following the use-case. For excitation a linear encoded chirp was used, for SNR improvements averaging of measurements (64 to 256 times) was conducted. The analysis compensated for the hydrophon’s frequency and angular damping characteristics. The presented results show that the desired characteristics were mostly achieved: the 6 dB bandwidth could be vastly improved by roughly 200% (see Fig. d.)). The 6 dB pressure opening angle was approx. 50◦ (see Fig. c.)), not completly fullfilling the simulated expectations, an improvement by 31% was achieved. The results are promising for the next 3D USCT III generation

Influence of nano-reinforcements on the mechanical properties and microstructure of titanium matrix composites

The goal of this work is the evaluation of nanoscaled reinforcements; in particular nanodiamonds (NDs) and carbon nanotubes (CNTs) on properties of titanium matrix composites (TiMMCs). By using nano sized materials as reinforcement in TiMMCs, superior mechanical and physical properties can be expected. Additionally, titanium powder metallurgy (P/M) offers the possibility of changing the reinforcement content in the matrix within a very wide range. In this work, TiMMCs have been produced from titanium powder (Grade 4). The manufacturing of the composites was done by hot pressing, followed by the characterisation of the TiMMCs. The Archimedes density, hardness and oxygen content of the specimens in addition to the mechanical properties were compared and reported in this work. Moreover, XRD analysis and SEM observations revealed in situ formed titanium carbide (TiC) phase after hot pressing in TiMMCs reinforced with NDs and CNTs, at 900 °C and 1100 °C respectively. The strengthening effect of NDs was more significant since its distribution was more homogeneous in the matrix

The Distribution of Melanocytes in the Leptomeninges of the Human Brain

The purpose of this study was to determine the qualitative and quantitative distribution of melanocytes in human leptomeninges by histochemical and ultrastructural techniques and to search for melanocytes in the mesothelial linings of the pleural and peritoneal cavities. Knowledge of the extracutaneous distribution of pigment cells will facilitate the interpretation of systemic symptoms in depigmentation disorders, such as vitiligo and the Vogt-Koyanagi-Harada syndrome.In 15 brains examined, leptomeningeal pigment cells were found principally over the ventrolateral surfaces of the medulla oblongata. Only isolated pigment-containing cells were found in the meninges covering other parts of the brain. The mean number of pigment cells in the medullary meninges of 5 brains was 325/mm2 ± 96. The presence of melanosomes as single, membrane- bound granules in all stages of melanization confirms that the melanin-containing dendritic cells of the leptomeninges are melanocytes and not macrophages.No pigmented cells were observed in the pleural or peritoneal samples examined

Государственное регулирование электроэнергетики

Цель работы – разработка теоретических и практических положений, направленных на совершенствование механизмов государственного регулирования электроэнергетики в России, выявление основных тенденций и возможных путей дальнейшего развития названной сферы в российской экономике. Объектом исследования являются отношения, возникающие в процессе осуществления государственного регулирования электроэнергетической отрасли в России.Purpose - to develop theoretical and practical provisions aimed at improving the mechanisms of state regulation of electric power industry in Russia, identifying the main trends and opportunities for further development of the said spheres of the Russian economy. The object of the study are the relations arising in the implementation of state regulation of electric power industry in Russia

Phase I/II study of the anti-oestrogen zindoxifene (D16726) in the treatment of advanced breast cancer. A Cancer Research Campaign Phase I/II Clinical Trials Committee study.

We report a phase I/II study of the indole derivative, zindoxifene, an anti-oestrogen with intrinsic oestrogenic activity. We have treated 28 women with advanced breast cancer of whom 26 had received prior endocrine therapy. Oral zindoxifene doses ranged from 10 to 100 mg daily; doses were escalated in some patients. Twenty-five patients were assessed for response; the remaining three patients completed less than 3 weeks of treatment. There were no objective responses; disease stabilised in seven patients for up to 5 months and progressed in the remaining 18. Five patients (including three treated with tamoxifen) responded to subsequent endocrine therapy. Nausea, which was dose-limiting, affected half of the patients treated with 80 mg daily. Metabolites of zindoxifene were detectable in serum at all doses used, and sex hormone binding globulin (SHBG) levels showed a strong tendency to rise at the higher doses, indicating that zindoxifene is absorbed and has biological activity. We conclude that zindoxifene in the doses used in this study has only marginal therapeutic activity in the treatment of advanced breast cancer

The PANDA GEM-based TPC Prototype

We report on the development of a GEM-based TPC prototype for the PANDA experiment. The design and requirements of this device will be illustrated, with particular emphasis on the properties of the recently tested GEM-detector, the characterization of the read-out electronics and the development of the tracking software that allows to evaluate the GEM-TPC data.Comment: submitted to NIMA 4 pages, 6 picture