Electron and Ion Heating Characteristics during Magnetic Reconnection in the MAST Spherical Tokamak.

Electron and ion heating characteristics during merging reconnection start-up on the MAST spherical tokamak have been revealed in detail using a 130 channel yttrium aluminum garnet (YAG) and a 300 channel Ruby-Thomson scattering system and a new 32 chord ion Doppler tomography diagnostic. Detailed 2D profile measurements of electron and ion temperature together with electron density have been achieved for the first time and it is found that electron temperature forms a highly localized hot spot at the X point and ion temperature globally increases downstream. For the push merging experiment when the guide field is more than 3 times the reconnecting field, a thick layer of a closed flux surface form by the reconnected field sustains the temperature profile for longer than the electron and ion energy relaxation time ~4-10 ms, both characteristic profiles finally forming a triple peak structure at the X point and downstream. An increase in the toroidal guide field results in a more peaked electron temperature profile at the X point, and also produces higher ion temperatures at this point, but the ion temperature profile in the downstream region is unaffected.

Percutaneous transcatheter right atrial stent placement for recurrent cor triatriatum dexter following initial surgical excision of right intra-atrial membrane in a dog.

A four-year-old spayed female Shiba Inu dog weighing 6.1 kg presented with ascites. Cor triatriatum dexter (CTD) without any other concurrent cardiovascular anomalies was diagnosed using echocardiography. The ostium of the abnormal membrane dividing the right atrium into two abnormal chambers was surgically excised under cardiopulmonary bypass. All clinical abnormalities were resolved after surgery. However, seven months later, ascites and CTD recurred. A balloon-expandable stent was placed at the site of recurrence, which improved caudal venous return to the right ventricle. After the second procedure, ascites were resolved, and the dog remained asymptomatic for 18 months without complications. There are previous reports of successful surgical resection of the CTD and of stenting in recurrent CTD following balloon dilation in dogs. However, to the authors' knowledge, no previous reports have described recurrent CTD in dogs after surgical resection of the CTD. In this case, as with recurrent CTD following balloon dilation, stent placement at the site of the CTD can be a viable treatment option when the abnormal membrane recurs.

Tunable terahertz emission from the intrinsic Josephson junctions in acute isosceles triangular Bi2Sr2CaCu2O8+δ mesas.

In order to determine if the mesa geometry might affect the properties of the coherent terahertz (THz) radiation emitted from the intrinsic Josephson junctions in mesas constructed from single crystals of the high-temperature superconductor, Bi2Sr2CaCu2O8+δ, we studied triangular mesas. For equilateral triangular mesas, the observed emission was found to be limited to the single mesa TM(1,0) mode. However, tunable radiation over the range from 0.495 to 0.934 THz was found to arise from an acute isosceles triangular mesa. This 47% tunability is the widest yet observed from the outer current-voltage characteristic branch of such mesas of any geometry. Although the radiation at a few of the frequencies in the tunable range appear to have been enhanced by cavity resonances, most frequencies are far from such resonance frequencies, and can only be attributed to the ac-Josephson effect.

Influence of fetal hiccups on Doppler blood flow waveform of fetal arteries: Difference among arteries.

BACKGROUND: A few studies have been reported on the influence of fetal hiccups on umbilical artery. The aim of this study is to clarify the influence of fetal hiccups on Doppler blood flow waveform (DBFW) of some fetal arteries, and to show the difference in these influences among fetal arteries. OBJECTIVE: DBFW of umbilical artery, descending aorta, and middle cerebral artery were recorded at hiccups in normal fetuses between 34th and 40th gestational weeks. The changes on DBFW were classified into three shapes by the direction and the size of the changes. Shape 1: sharp decrease but not to the baseline, Shape 2: sharp decrease to the baseline (absence), and Shape 3: reverse flow. RESULTS: At all hiccups, the changes on DBFW of these arteries were observed. These changes were classified into three shapes. Changes of umbilical artery were widely distributed in three shapes depending on when hiccup occurred during cardiac cycle. On the other hand, most changes of the descending aorta and middle cerebral artery were Shape 3 whenever the hiccup occurred during cardiac cycle. CONCLUSION: The changes on DBFW of fetal arteries were observed at all hiccups. Changes of umbilical artery were widely distributed in three shapes depending on when hiccup occurred during cardiac cycle. On the other hand, most changes of descending aorta and middle cerebral artery were Shape 3. This is the first study clarified the influence of fetal hiccups on DBFW of some fetal arteries, and showed the difference in these influences among fetal arteries.

[Patient skin injury in cardiac intervention procedures].

PURPOSE: To discuss the circumstances of patient skin injury in cardiac interventional radiology (IVR). To demonstrate the importance of evaluating the patient radiation dose in IVR. To show the need for the appropriate patient follow-up after IVR to identify radiation effects. To highlight the incidence of skin injuries during IVRs. CONTENT ORGANIZATION: Evaluation of 400 consecutive percutaneous coronary interventions (PCIs). The radiation dose, number of cine runs, and fluoroscopic time were recorded for all patients. The skin on the patients' backs was reviewed periodically after PCI to identify radiation injury. The relationships between patient skin effects and factors such as the radiation dose were investigated. Reviewing previous reports of patient radiation injury occurrence rate, fluoroscopic time, radiation dose (if available), etc. SUMMARY: Although increasing numbers of case reports of patient radiation injury resulting from IVR are being published, these reports likely represent a small fraction of actual cases. Radiation skin injury in IVR is overlooked clinically in many patients. Patients who receive a high radiation dose while undergoing IVR should be followed to identify radiation skin effects, and physicians should seek to establish whether a patient has had previous IVR, together with the entrance site and radiation dose.

Diversity in the Oryza genus.

The pan-tropical wild relatives of rice grow in a wide variety of habitats: forests, savanna, mountainsides, rivers and lakes. The completion of the sequencing of the rice nuclear and cytoplasmic genomes affords an opportunity to widen our understanding of the genomes of the genus Oryza. Research on the Oryza genus has begun to help to answer questions related to domestication, speciation, polyploidy and ecological adaptation that cannot be answered by studying rice alone. The wild relatives of rice have furnished genes for the hybrid rice revolution, and other genes from Oryza species with major impact on rice yields and sustainable rice production are likely to be found. Care is needed, however, when using wild relatives of rice in experiments and in interpreting the results of these experiments. Careful checking of species identity, maintenance of herbarium specimens and recording of Genbank accession numbers of material used in experiments should be standard procedure when studying wild relatives of rice.

0.43 THz emission from high-T(c) superconducting emitters optimized at 77 K.

A liquid helium-free, compact and continuous sub-terahertz radiation system operating at 77 K has been developed using a rectangular mesa device made from a high T(c)-superconducting Bi2Sr2CaCu2O(8+δ) single crystal, based on a different design of a stand-alone mesa sandwich structure to reduce the dc-current Joule heating effects. The mesa was thermally connected to sapphire plates through thin thermal grease embedded with diamond nano-crystals. When immersed in liquid N 2, the device emits intense radiation at 0.437 THz, the highest frequency ever achieved at 77 K, due to excitation of the TM(1, 0) rectangular cavity mode. By varying the dc current-voltage bias and the bath temperature in a He-flow cryostat, the device's emission frequency is broadly tunable from 0.31 THz at 79 K to 1.31 THz at 30 K.

Up-regulation of nitric oxide synthase (NOS) gene expression together with NOS activity in the rat hypothalamo-hypophysial system after chronic salt loading: evidence of a neuromodulatory role of nitric oxide in arginine vasopressin and oxytocin secretion.

Chronic salt loading up-regulated the expression of neuronal nitric oxide synthase (NOS) mRNA in the supraoptic nucleus (SON) and paraventricular nucleus (PVN) of the hypothalamus with a concomitant increase in NOS activity in the posterior pituitary. Once daily ip injection of N-omega-nitroarginine (N-Arg), a NOS inhibitor, significantly inhibited NOS activity in the posterior pituitary in a dose-dependent manner, but did not influence NOS mRNA levels. Two percent salt loading for 3 or 4 days significantly depleted the contents of both arginine vasopressin (AVP) and oxytocin (OT) in the posterior pituitary, and simultaneous treatment with daily injections of N-Arg at a dose of 10 mg/kg significantly enhanced the depletion of both AVP and OT. This effect was dose dependent and paralleled the inhibition of NOS activity in the posterior pituitary. N-Arg treatment had no effect on the levels of both AVP and OT transcripts in PVN or SON. These results suggest that NOS gene expression in the SON and PVN of the rat hypothalamus is increased during hyperosmotic stimulation and suggest a neuromodulatory role for NO in the rat hypothalamo-hypophysial system as an inhibitory regulator of AVP and OT secretion.

Tumor necrosis factor-alpha increases release of arachidonate and prolactin from rat anterior pituitary cells.

We investigated the effect of tumor necrosis factor-alpha (TNF alpha), a product of activated macrophages, on the release of arachidonate from dispersed anterior pituitary cells. Primary cultures of anterior pituitary cells from rats were preincubated with [3H]arachidonate to label their phospholipid-containing components. The cells were then washed and incubated with vehicle or test agents, and PRL release into the medium and [3H]arachidonate cleaved from phospholipid were measured. TNF alpha significantly increased the release of both PRL and [3H] arachidonate release in a time- and dose-dependent manner. Other cytokines, such as interleukin-1 alpha, interleukin-1 beta, and gamma-interferon, had no effect on [3H]arachidonate release. To define the role of calcium in TNF alpha-induced arachidonate release, dispersed pituitary cells were incubated with low calcium medium, which decreased arachidonate release in response to TNF alpha. TNF alpha potentiated the release of [3H]arachidonate and PRL promoted by phospholipase-A2 and melittin, and markedly shifted the dose-response curve to the left. Inhibitors of phospholipase-A2, such as p-bromophenacyl bromide and quinacrine, had no effect on TNF alpha-induced [3H]arachidonate and PRL release. BW755C, an inhibitor of the conversion of arachidonate to its metabolites, decreased TNF alpha-induced PRL release, while indomethacin, a prostaglandin synthesis inhibitor, had no effect on TNF alpha-induced PRL release. These data indicate that arachidonate metabolites may be involved in the process of TNF alpha-induced PRL release.

Mitochondrial sequence migrated downstream to a nuclear V-ATPase B gene is transcribed but non-functional.

A promiscuous nuclear sequence containing a mitochondrial DNA fragment was isolated from rice. Nucleotide sequence analysis reveals that the cDNA clone #21 carries a mitochondrial sequence homologous to the 3' portion of the rps19 gene followed by the 5' portion of the rps3 gene. The mitochondrial sequence is present in an antisense orientation. Sequence comparison of the #21 cDNA with the original mitochondrial sequence shows 99% similarity, suggesting a recent transfer event. Moreover, evidence for a lack of an RNA editing event and retaining of the group II intron sequence strongly suggests that the sequence was transferred from mitochondrion to the nucleus via DNA rather than RNA as an intermediate. The upstream region to the mitochondria-derived sequence shows homology to part of the vacuolar H(+)-ATPase B subunit (V-ATPase B) gene. Isolation of a functional V-ATPase B cDNA and its comparison with the #21 cDNA reveal a number of nucleotide substitutions resulting in many translational stop codons in the #21 cDNA. This indicates that the #21 cDNA sequence is not functional. Analysis of genomic sequences shows the presence of five intron sequences in the #21 cDNA, whereas the functional V-ATPase B gene has 14 introns. Of these, three exons and their internal two introns are homologous to each other, suggesting a duplication event of V-ATPase B genomic DNA. The results of this investigation strongly suggest that the mitochondrial sequence was integrated in an antisense orientation into the pre-existing V-ATPase B pseudogene that can be transcribed and spliced. This represents a case of unsuccessful gene transfer from mitochondrion to the nucleus.

Involvement of 5' flanking sequence for specifying RNA editing sites in plant mitochondria.

Unsuccessful insertion of foreign DNA into plant mitochondrial genomes has hindered scientific evaluation of cis-elements needed for RNA editing. Both a normal atp6 gene and a chimeric atp6 sequence are present in rice mitochondria. The chimeric atp6 contains one-half of the normal atp6 sequence in its 5' portion and an unknown sequence in its downstream portion. The C-nucleotide at position 511, located just upstream of the unknown sequence recombined in the chimeric atp6 sequence, is edited, as are other possible editing sites upstream from position 511. We report here that the 5' sequence adjacent to the editing site of atp6 contains cis-information required for RNA editing and that the 3' sequence flanking the editing site provides little contribution to editing-site recognition.

Age related change in the frequency of ara C-induced chromosome aberrations in human peripheral blood lymphocytes.

1-beta-D-Arabinofuranosylcytosine (ara C) has been known to inhibit repair replication in the G1 phase of cell cycle and to convert certain types of DNA damage into chromosome-type exchanges: e.g., dicentric or ring chromosomes. It is then considered to be a useful cytogenetic method to investigate the frequency of ara C-induced dicentric and ring chromosomes (dic and ring) for estimating cellular DNA damage or capacity to repair it. Peripheral blood lymphocytes from donors ranging from newborn to 91 years old were treated with 10 microM ara C in their G1 phase and the resulting disc and ring were observed to investigate whether age-related change in peripheral lymphocytes would be present in the amount of spontaneous DNA damage or in the capacity to repair it. Chromatid-type (Ct) aberrations and sister chromatid exchanges (SCEs) were also scored for additional cytogenetic indices of DNA damage in the lymphocytes. The results showed that the frequency of dic and ring had a negatively linear correlation with the logarithm of the age of the blood donors, but that the frequencies of Ct aberrations and SCEs were not influenced by the age. The present study suggests the presence of age-related change in the amount or in the capacity to repair certain types of DNA damage in the G1 phase of human peripheral lymphocytes. Other possible explanations for the present results are also discussed.

Increase in galanin gene expression in locus coeruleus neurones of the rat following reserpine treatment.

Changes in galanin mRNA content in locus coeruleus neurones of the rat were studied after reserpine treatment (10 mg/kg s.c.) using an in situ hybridization technique and an alkaline phosphatase labelled oligodeoxynucleotide probe. An increase in galanin mRNA content in locus coeruleus neurones was detected as early as 3 h after reserpine treatment when compared to vehicle injected rats. A maximal increase in mRNA content was detected at 3 days after reserpine treatment. This transient increase in galanin mRNA content had subsided by post treatment day 20. The response of locus coeruleus neurones to the single reserpine injection was heterogeneous; cells in the dorsal portion of the nucleus exhibiting a greater response than ventrally located cells.

Fermi surface of Bi2Sr2CaCu2O8

We study the Fermi surface of Bi2Sr2CaCu2O8 using angle resolved photoemission spectroscopy (ARPES) with a momentum resolution of approximately 0.01 of the Brillouin zone. We show that, contrary to recent suggestions, the ARPES derived Fermi surface is a large hole barrel centered at (pi,pi), independent of the incident photon energy. We caution that the photon energy and k dependence of the matrix elements, if not properly accounted for, can lead to misinterpretation of ARPES intensities.

Quasiparticles in the superconducting state of Bi(2)Sr(2)CaCu(2)O(8+delta)

Recent improvements in momentum resolution lead to qualitatively new angle-resolved photoemission spectroscopy results on the spectra of Bi(2)Sr(2)CaCu(2)O(8+delta) (Bi2212) along the (pi,pi) direction, where there is a node in the superconducting gap. We now see the intrinsic line shape, which indicates the presence of true quasiparticles at all Fermi momenta in the superconducting state, and lack thereof in the normal state. The region of momentum space probed here is relevant for charge transport, motivating a comparison of our results to conductivity measurements by infrared reflectivity.

Differentiation of Dunn osteosarcoma cells in response to dibutyryl cyclic 3',5'-adenosine monophosphate.

We investigated the effects of dibutyryl cyclic adenosine 3',5'-monophosphate (Bt2cAMP) on the differentiation of Dunn osteosarcoma cells. Flow-cytometric analysis and DNA synthesis assay showed that Bt2cAMP decreased the cell population in the S phase in a time- and dose-dependent manner. Also, the cells showed distinct morphological and functional alterations; the cell morphology changed to a fibroblast-like appearance with long and thin protoplasmic processes, the knobs or blebs on both the cell membrane and nuclear membrane disappeared and the intracellular alkaline phosphatase activity increased. Moreover, Bt2cAMP-treated cells secreted a large quantity of fibronectin, which was deposited on the extended cell surface in the culture medium. Thus, Dunn osteosarcoma cells are differentiated morphologically and functionally by Bt2cAMP, and might be transformed to benign precursor cells.

The efficient production of human epidermal growth factor by Bacillus brevis.

A system has been developed for the efficient production of heterologous proteins using Bacillus brevis as a host that secretes large amounts of cell wall protein into the medium. The promoter region and signal peptide-encoding region of the cell wall protein gene were used to construct an expression-secretion vector. Bacterial proteins such as amylases can be produced in large amounts by this system (1 g/l or more), but mammalian proteins such as human alpha-amylase are produced at a low level (one or two orders of magnitude less than for bacterial proteins). The highly efficient secretion of human epidermal growth factor (h-EGF, more than 1 g/l) was obtained with B. brevis HPD31 as the host and plasmid pHY481, derived from B. brevis 481, as the vector. Recombinant hEGF was purified easily from the culture supernatant by two steps. Purified hEGF had the identical NH2-terminal amino acid sequence and COOH-terminal amino acid sequence with those of the authentic hEGF, and it was fully active in biological assays. This recombinant hEGF has been shown to be successful for biological wool harvesting (CSIRO, Australia). These results, in combination with previous results, indicate that foreign proteins of diverse origins can be produced efficiently as functional proteins in B. brevis.

Distribution of calcium binding protein mRNAs in rat cerebellar cortex.

The distribution of three calcium binding protein mRNAs in the rat cerebellar cortex was investigated using alkaline phosphatase labelled specific antisense oligodeoxynucleotide probes. Calbindin D28k mRNA was detected in the Purkinje cells, parvalbumin mRNA was located in the Purkinje cells and also in basket/stellate cells of the molecular layer. Calretinin in contrast was found only in the granule cell layer. Use of multiple alkaline phosphatase (AP)-labelled oligodeoxynucleotides resulted in an increase in signal strength and reduced detection time with no increase in background staining indicating the utility of these enzyme labelled probes for non-isotopic in situ.

RNA editing of transcripts of the gene for apocytochrome b (cob) in rice mitochondria.

RNA editing was examined in rice mitochondrial apocytochrome b (cob) transcripts. Nineteen C-U conversions were found, and most of them changed the polypeptide sequence encoded by genomic DNA sequence. Evidence for partial and excess editing was also found.

Identification of cDNA encoding cytochrome c oxidase subunit 5c (COX5c) from rice: comparison of its expression with nuclear-encoded and mitochondrial-encoded COX genes.

Little is presently known about the nuclear-encoded genes for cytochrome c oxidase (COX) in higher plants. In rice, only the nuclear-encoded COX5b gene has been reported. To understand the relationship between the expression of nuclear-encoded and mitochondrial-encoded COX genes in rice, we first characterized a cDNA encoding one of the other nuclear COX genes, COX5c, which encodes 63 amino acids. The deduced amino acid sequence of COX5c from rice was highly homologous to that from sweet potato. Genomic Southern hybridization indicated that the rice COX5c subunit is encoded by a single copy of the COX5c gene. Furthermore, we compared the expression patterns of the nuclear-encoded COX5c and COX5b genes with the expression pattern of the mitochondrial-encoded COX1 gene among several organs by Northern blot analysis. The results suggested that regulatory systems of expression between the nuclear-encoded and the mitochondrial-encoded COX genes are different among different organs in rice.