155 research outputs found
Large-Scale Plasma Polymer Coating on Heat Exchanger Fins for Improving the Wettability
This research presents the results of the recently developed large-scale hydrophilic polymer coating by plasma polymerization, optimum plasma zone (OPZ) process. The excellent hydrophilicity of heat exchanger fin surface could give good effects to efficient drainage of condensate water as well as heat transfer performance. The hydrophilicity of layer treated by large-scale OPZ system is excellent irrespective of line speed from 0.6 m/min to 2.4 m/min. The good lateral uniformity of the hydrophilicity could be acquired in large scale OPZ treatment. The application of OPZ technique to the heat exchanger could enhance the efficiency of heat transfer, resulting from decrease of pressure drop. Due to long-term durability of hydrophilicity, the heat transfer performance improved by OPZ process cannot be deteriorated with operation cycle
Anatomic variations of the T2 nerve root (including the nerve of Kuntz) and their implications for sympathectomy
AbstractObjective: The aim of this study was to clarify the anatomic variations of the intrathoracic nerve of Kuntz, and this should help delineate the resection margins during video-assisted thoracic sympathectomy. Methods: Sixty-six thoracic sympathetic chains of 39 adult Korean cadavers were dissected on both sides of the thorax in 27 cadavers (54 sides) and on one side in 12 cadavers (12 sides). Results: The intrathoracic nerve was observed in 45 (68.2%) sides and was present bilaterally in 48.1% of cadavers. No intrathoracic nerve or ascending ramus communicans arising from the second thoracic nerve was observed in only 5 (7.6%) sides. The diameter of the intrathoracic nerve was 1.25 ± 0.55 mm on average. The arising point of the intrathoracic nerve from the second thoracic nerve was 7.3 mm on average from the sympathetic trunk. Presence of the stellate ganglion was noted in 56 (84.8%) sides, and 6 (9.1%) sides showed a single large ganglion formed by the stellate and the second thoracic sympathetic ganglia. The second thoracic sympathetic ganglion was most commonly located (50%) in the second intercostal space. Conclusion: The anatomic variations of the intrathoracic nerve of Kuntz and the second thoracic sympathetic ganglion were characterized in human cadavers. It is hoped that this study will help to improve the recurrence of symptoms caused by the intrathoracic nerve in an upper thoracic sympathectomy for hyperhidrosis.J Thorac Cardiovasc Surg 2002;123:498-50
Permanent Hydrophilic Surface Formation by Ion Assisted Reaction
Since totally wettable hydrophilic polymer surfaces from hydrophobic polymers (PMMA, PTFE, PET and PC) have been demonstrated for the first time at Materials Research Society meeting, 1995 Fall meeting, Boston, the application of ion assisted reaction (IAR), in which energetic ions (0.5~1.5 keV) are irradiated on materials with blowing reactive gases near the irradiating surfaces, has been extended to various polymer, ceramic and metal for creating permanent hydrophilic surfaces. The surface energy was measured by Youngs equation and the highest energy, Es, of 60~70 mN/m, which is similar to surface energy of water (Es of H2O : 72 mN/m) is obtained by controlling ion dose, energy, and amount of blown gas. The higher surface energy of materials possesses the more wettable surface, and relation between wettability and adhesion has been discussed. The remarkable result is the strong adhesion of inert nonattachable material such as Pt on the modified surface. The improvements of adhesions, wettability and surface energy are mainly due to polar force and hydrophilic functional groups such as C=O, (C=O)-O, C-O, etc. on the modified surface without surface damage by surface analyses. Advantages of the method are (1) high reproducibility, (2) simplicity, (3) changing ability of wettability degree, and (4) easy connection to conventional semiconductor process line. Improvements of efficiencies by changing heat transfer coefficients have been presented for the compact heat exchanger system
Dissecting Aneurysm Associated with a Double Origin of the Posterior Inferior Cerebellar Artery Causing Subarachnoid Hemorrhage
Two cases of the posterior fossa dissecting aneurysm associated with a double origin of the posterior inferior cerebellar artery (DOPICA) causing subarachnoid hemorrhage are presented. After observing a relationship between the aneurysm and DOPICA on a three dimensional rotational angiogram (3DRA), the dissecting aneurysms were successfully obliterated by surgical trapping and endovascular internal trapping, respectively. This report warrants suspecting DOPICA of an associating anomaly predisposing to dissecting aneurysm in the vertebral artery-posterior inferior cerebellar artery territory and highlights the role of 3DRA in pretreatment evaluation of unusual aneurysms accompanying a particular anatomical variation
Genetic Analysis of Three Korean Patients with Clinical Features of Ehlers-Danlos Syndrome Type IV
Ehlers-Danlos syndrome (EDS) is a hereditary disorder of the connective tissue. EDS type IV (EDS IV), the vascular type of the disease, is characterized by easy bruising, thin skin with visible veins, and spontaneous rupture of the large arteries, uterus, or bowel. EDS IV is caused by mutations in the gene for type III procollagen (COL3A1). However, recent studies suggest that the causative mutation of EDS IV is not homogeneous. We report our experience with three patients presenting with clinical features of type IV EDS. A 48-yr-old woman presented with acute aortic dissection (patient 1) and 36-yr-old and 21-yr-old women presented with carotid-cavernous fistula (patients 2 and 3, respectively). All three patients bruised easily. Two patients (patients 1 and 3) had thin transparent skin with visible veins. Genetic analysis of COL3A1 revealed a Gly732Val (c.2195G>T) mutation in patient 1 and a duplication of 15 base pairs (c.3221_3235dup) which resulted in an interposition of five amino acids (p.Gly1074_Pro1078dup) in patient 2. However, no mutations were observed in COL3A1 or transforming growth factor β receptors 1 and 2 in patients 3, which might be either due to a deletion of single or multiple exons in the COL3A1 gene or due to a genetic heterogeneity. This is the first report of genetically confirmed cases of EDS IV in Korea
Reinterpretation of anthocyanins biosynthesis in developing black rice seeds through gene expression analysis
The biosynthesis of anthocyanins is still questionable in regulating the quantities of anthocyanins biosynthesized in rice seeds and the expression levels of transcription factors and the structural genes involved in the biosynthetic pathway of anthocyanins. We herein investigated the relationship between the accumulated anthocyanin contents and the expression levels of genes related to the biosynthesis of anthocyanins in rice seeds. Liquid chromatography/mass spectrometry-mass spectrometry analysis of cyanidin 3-glucoside (C3G) in rice seeds showed no accumulation of C3G in white and red rice cultivars, and the differential accumulation of C3G among black rice cultivars. RNA-seq analysis in rice seeds, including white, red, and black rice cultivars, at twenty days after heading (DAH) further exhibited that the genes involved in the biosynthesis of anthocyanins were differentially upregulated in developing seeds of black rice. We further verified these RNA-seq results through gene expression analysis by a quantitative real-time polymerase chain reaction in developing seeds of white, red, and black rice cultivars at 20 DAH. Of these genes related to the biosynthesis of anthocyanins, bHLHs, MYBs, and WD40, which are regulators, and the structural genes, including chalcone synthase (CHS), flavanone 3-hydroxylase (F3H), flavonoid 3´-hydroxylase (F3´H), dihydroflavonol 4-reductase (DFR), and anthocyanidin synthase (ANS), were differentially upregulated in black rice seeds. The correlation analysis revealed that the quantities of C3G biosynthesized in black rice seeds were positively correlated to the expression levels of bHLHs, MYBs and WD40, CHS, F3H, F3´H, DFR, and ANS. In addition, we present bHLH2 (LOC_Os04g47040) and MYBs (LOC_Os01g49160, LOC_Os01g74410, and LOC_Os03g29614) as new putative transcription factor genes for the biosynthesis of anthocyanins in black rice seeds. It is expected that this study will help to improve the understanding of the molecular levels involved in the biosynthesis of anthocyanins in black rice seeds
Transcriptional changes in the developing rice seeds under salt stress suggest targets for manipulating seed quality
Global sea-level rise, the effect of climate change, poses a serious threat to rice production owing to saltwater intrusion and the accompanying increase in salt concentration. The reclaimed lands, comprising 22.1% of rice production in Korea, now face the crisis of global sea-level rise and a continuous increase in salt concentration. Here, we investigated the relationship between the decrease in seed quality and the transcriptional changes that occur in the developing rice seeds under salt stress. Compared to cultivation on normal land, the japonica rice cultivar, Samgwang, grown on reclaimed land showed a greatly increased accumulation of minerals, including sodium, magnesium, potassium, and sulfur, in seeds and a reduced yield, delayed heading, decreased thousand grain weight, and decreased palatability and amylose content. Samgwang showed phenotypical sensitivity to salt stress in the developing seeds. Using RNA-seq technology, we therefore carried out a comparative transcriptome analysis of the developing seeds grown on reclaimed and normal lands. In the biological process category, gene ontology enrichment analysis revealed that the upregulated genes were closely associated with the metabolism of biomolecules, including amino acids, carboxylic acid, lignin, trehalose, polysaccharide, and chitin, and to stress responses. MapMan analysis revealed the involvement of upregulated genes in the biosynthetic pathways of abscisic acid and melatonin and the relationship of trehalose, raffinose, and maltose with osmotic stress. Interestingly, many seed storage protein genes encoding glutelins and prolamins were upregulated in the developing seeds under salt stress, indicating the negative effect of the increase of storage proteins on palatability. Transcription factors upregulated in the developing seeds under salt stress included, in particular, bHLH, MYB, zinc finger, and heat shock factor, which could act as potential targets for the manipulation of seed quality under salt stress. Our study aims to develop a useful reference for elucidating the relationship between seed response mechanisms and decreased seed quality under salt stress, providing potential strategies for the improvement of seed quality under salt stress
Report of a Korean Patient with Cystic Fibrosis, Carrying Q98R and Q220X Mutations in the CFTR Gene
Although cystic fibrosis (CF) is one of the most frequently seen autosomal-recessive disorders in Caucasians, it is extremely rare in the Korean population. Recently, a 15-yr-old Korean boy was admitted to our hospital complaining of coughing, sputum, and exertional dyspnea. Chest radiographs and computed tomographic chest and paranasal sinus scans revealed diffuse bronchiectasis and pansinusitis. Pulmonary function tests revealed severe obstructive impairment. The average sweat chloride concentrations on both of the patients' forearms were 63.0 mM/L (reference limit: <40 mM/L). Upon mutation analysis, two different mutations (Q98R and Q220X) were identified in the cystic fibrosis transmembrane conductance regulator gene, both of which had been previously detected in CF patients, one from France and the other from England. As CF is quite rare in Korea, the diagnosis of CF in this patient might be delayed. Therefore, we recommend that a diagnosis of CF should be suspected in patients exhibiting unexplained chronic respiratory symptoms
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