Molecular cloning of a novel putative Ca2+ channel protein (TRPC7) highly expressed in brain

BACKGROUND: Skeletal muscle abnormalities contribute considerably to the clinical expression of heart failure. Deconditioning, underperfusion and an increased number of type IIb glycolytical fibres lead to early lactate production and muscle fatigue at low exercise levels. Aerobic muscle metabolism may also be impaired, as suggested by biopsy studies. Thus far, no data are available from non-invasive studies to indicate the extent of aerobic muscle dysfunction during low-grade exercise which does not induce acidosis. METHODS AND RESULTS: Mitochondrial function of skeletal muscle during fibre type I activation was studied in 22 patients with chronic heart failure [NYHA class III, left ventricular ejection fraction 28 +/- 2%, (patients)] on ACE inhibitors, diuretics and digoxin, and in 20 normal subjects, using 31P NMR spectroscopy of a single right forearm flexor muscle during three mild intermittent exercise levels (0-40% of maximum voluntary contraction) and recovery time. At rest, the inorganic phosphate/phosphocreatine ratio was different [0.13 +/- 0.005 (patients) vs 0.09 +/- 0.002 (normal subjects), P = 0.0001]. However, intracellular pH was comparable. Local acidosis (tissue pH < 6.9) was avoided to prevent fibre type IIb activation. Calculated resting phosphate potential levels were comparable, but the slope and intercept of the linear relationship of phosphate potential and workload were significantly lower in patients than in normal subjects (11.7 +/- 0.7 vs 15.8 +/- 0.6 and 139 +/- 7 vs 196 +/- 7, patients vs normal subjects, indicating early exhaustion of intracellular energy at lower exercise levels. Also, maximum calculated workload at which tissue ADP stabilized was lower in patients than in normal subjects (88 +/- 7% vs 120 +/- 4% of maximum voluntary workload, patients vs normal subjects, P < 0.05). Time to recovery to pre-test phosphocreatine levels was prolonged by 46% in patients compared to normal subjects (P < 0.05). CONCLUSIONS: In heart failure, oxidative fibre mitochondrial function in skeletal muscle is impaired, as reflected by the reduced phosphate potential and oxidative phosphorylation rate, early exhaustion and slowed recovery of intracellular energy reserve at workloads, which do not affect intracellular pH.     

Mass transfer accompanied by chemical reaction at the surface of a single droplet

Mass transfer accompanied by chemical reaction at the surface of a droplet in the free-rise period has been studied. Theoretical analysis was carried out on the basis of two typical models; one is the stagnant spherical drop model proposed by Newman, and the other is the model which accounts for the turbulent circulation in a droplet proposed by Handlos and Baron. Diffusion equations for these models were numerically solved under the boundary conditions which accounts for the chemical reaction at the drop surface. Two cases were discussed. One is the case in which mass transfer resistance in the continuous phase can be ignored, and the other is the case in which it should be accounted for. In the former case, it was found that the mass transfer rate increased with an increase of the initial concentration of reaction component in a droplet when the reaction order is greater than unity.The reverse case occurs when the reaction order is smaller than unity. In the latter case, it was revealed that the mass transfer rate increased with an increase of the initial concentration of the dispersed phase component when it is small but decreased when it is large.On the basis of these results of the theoretical analysis, the extraction rate of acetic acid by Amberlite LA-2, secondary long-chain alkylamine, was examined. As a result of the examination, the experimental results were fairly well explained by the model which takes account of the interfacial reaction of first order with respect to either acetic acid or amine.     

Identification and analysis of specific chromosomal region adjacent to exogenous Dhfr-amplified region in Chinese hamster ovary cell genome

Chinese hamster ovary (CHO) cells are widely used for the stable production of recombinant proteins. Gene amplification techniques are frequently used to improve of protein production, and the dihydrofolate reductase (DHFR) gene amplification system is most widely used in the CHO cell line. We previously constructed a CHO genomic bacterial artificial chromosome (BAC) library from a mouse Dhfr-amplified CHO DR1000L-4N cell line and one BAC clone (Cg0031N14) containing the CHO genomic DNA sequence adjacent to Dhfr was selected. To identify the specific chromosomal region adjacent to the exogenous Dhfr-amplified region in the CHO cell genome, we performed further screening of BAC clones to obtain other Dhfr-amplified regions in the CHO genome. From the screening by high-density replica filter hybridization using a digoxigenin-labeled pSV2-dhfr/hGM-CSF probe, we obtained 8 new BAC clones containing a Dhfr-amplified region. To define the structures of the 8 BAC clones, Southern blot analysis, BAC end sequencing and fluorescence in situ hybridization (FISH) were performed. These results revealed that all the selected BAC clones contained a large palindrome structure with a small inverted repeat in the junction region. This suggests that the obtained amplicon structure in the Dhfr-amplified region in the CHO genome plays an important role in exogenous gene amplification.     

Iterative Overlap QRM-ML Block Detection for Single-Carrier MIMO Transmission Without CP Insertion

QR decomposition and M-algorithm based near maximum likelihood block detection (QRM-MLBD) significantly improves the single-carrier (SC) multiple-input multiple-output (SC-MIMO) transmission performance in a frequency-selective fading channel. In the conventional QRM-MLBD, the cyclic prefix (CP) is inserted in order to avoid the inter-block interference (IBI). However, CP insertion reduces the transmission efficiency. In this paper, an iterative overlap QRM-MLBD is proposed for SC-MIMO transmission with no CP insertion. It is confirmed by computer simulation that the iterative overlap QRM-MLBD with no CP insertion provides improved throughput performance while reducing the computational complexity over the conventional QRM-MLBD with CP insertion.     

A distribution line model for lightning overvoltage studies

Recently, the focus of lightning protection measures for distribution lines has moved from a nearby lightning stroke to a direct lightning stroke. Studies of direct lightning stroke countermeasures are generally carried out by digital simulations using the EMTP (Electro‐Magnetic Transients Program). Thus, components of a distribution line must be modeled appropriately in the EMTP for accurate simulations. The authors have previously clarified the surge response of a distribution line by pulse tests using a reduced‐scale distribution line model. In this paper, first, the results of the pulse tests are simulated in the EMTP using a conventional model which represents a distribution pole by a single lossless distributed‐parameter line model, and comparisons with the test results show that transient overvoltages generated at the insulators cannot accurately be reproduced by the conventional model. This indicates that a special treatment is required to represent the transient response of a distribution pole and wires. Then, this paper proposes new EMTP models of the pole and wires which can reproduce the transient overvoltages at the insulators. The parameter values of the proposed models can be determined based on a pulse test result. © 2010 Wiley Periodicals, Inc. Electr Eng Jpn, 173(1): 11–23, 2010; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.21001     

Spatial organization of the Schizosaccharomyces pombe genome within the nucleus

The fission yeast Schizosaccharomyces pombe is a useful experimental system for studying the organization of chromosomes within the cell nucleus. S. pombe has a small genome that is organized into three chromosomes. The small size of the genome and the small number of chromosomes are advantageous for cytological and genome‐wide studies of chromosomes; however, the small size of the nucleus impedes microscopic observations owing to limits in spatial resolution during imaging. Recent advances in microscopy, such as super‐resolution microscopy, have greatly expanded the use of S. pombe as a model organism in a wide range of studies. In addition, biochemical studies, such as chromatin immunoprecipitation and chromosome conformation capture, have provided complementary approaches. Here, we review the spatial organization of the S. pombe genome as determined by a combination of cytological and biochemical studies. Copyright © 2016 John Wiley & Sons, Ltd.     

Superheated emulsions as high-energy neutron dosemeters

Superheated emulsions being inexpensive, easy to fabricate, and having tissue equivalent composition make them as one of the popular neutron dosemeters. One more advantage is that they can be made insensitive to gamma rays by the choice of the sensitive liquid. It is observed that the response of commercially available bubble detector to neutron decreases above 20 MeV while its response is roughly flat in the 0.1-15 MeV region. This restricts its application as a dosemeter to high-energy neutrons. The response of bubble detector from Bubble Technology Industries, has been observed by using Pb-breeder for high-energy neutrons from different facilities in Japan. It is observed that 2-3 cm Pb-breeder is effective in increasing the response of the detector to the nominal value. Theoretical calculation using MCNPX code indicates an increase in neutrons in the energy range of 0.1-10 MeV with Pb-breeder. The present work indicates the possibility of using the bubble detector as a dosemeter to high-energy neutron using a Pb-breeder of proper thickness.