Search Results - (Author, Cooperation:H. W. Kim)

2013-10-05

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

2018-08-24

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Geosciences

Computer Science

Medicine

Natural Sciences in General

Physics

Physics, Applied, Physics

1089-7550

AIP Digital Archive

Physics

Deep-level transient spectroscopy (DLTS) measurements have been made to obtain the activation energy and capture cross section in Schottky diodes. Previous theories for interface state density (ISD) functions, which are derived for metal-semiconductor junctions, made approximations that were inappropriate. This paper derives improvements to the previous analysis and calculates ISD using the measured DLTS data. As for examples, Schottky diodes of Si, GaAs, and AlxGa1−xAs have been investigated with both methods. It has been found that the previously used method overestimated both the peak maximum position and peak height of the ISD.

Electronic Resource

1365-2826

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Cutaneous electrical or chemical stimulation can produce an anti-inflammatory effect, which is dependent on adrenal medullary-sympathetic activation. We have previously shown that peripheral injection of bee venom (BV) also produces a significant anti-inflammatory effect that is neurally mediated. In the present study, we examined whether this anti-inflammatory effect is also dependent on the adrenal gland using the mouse inflammatory air pouch model. Subcutaneous (s.c.) BV injection produced a marked suppression of leucocyte migration and tumour necrosis factor (TNF)-α concentration induced by zymosan injection into the air pouch. The role of the adrenal gland in this suppression was evaluated in adrenalectomized mice. Adrenalectomy significantly reversed the suppression of leucocyte migration and TNF-α elevation caused by BV. Serum concentrations of corticosteroid were increased in mice with zymosan-induced air-pouch inflammation and this increase was reduced by BV administration, suggesting that adrenal corticosteroid release is not involved in mediating the anti-inflammatory effects of BV. To test this hypothesis, the corticosteroid receptor antagonist (RU486) was administered and found not to affect the BV-induced inhibition of leucocyte migration. By contrast, pretreatment with the β-adrenergic antagonist propranolol reversed the BV-induced inhibitory effect on leucocyte migration. These results suggest that the anti-inflammatory effect of s.c. BV administration is mediated in part by the release of catecholamines from the adrenal medulla.

Electronic Resource

1439-0264

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

This study is designed to demonstrate the distribution of nociceptin, endogenous ORL1 receptor ligand, in the central nervous system of the Mongolian gerbil. To intensify the nociceptin-like immunoreactivity (NOC-LI), colchicine was administered into the lateral ventricle, at 48 h prior to the trans-cardiac perfusion. In the group without colchicine treatment, NOC-LI was observed in the fibres of the spinal dorsal horn, specifically in the superficial layers. However, the NOC-LI in the superficial layers disappeared after the administration of colchicine. In the brain, NOC-LI was prominent in the hypothalamus, hippocampus, cerebral peduncle, substantia nigra, dorsal raphe, periaqueductal grey, locus coeruleus and trapezoid nucleus. Colchicine treatment markedly intensified the NOC-LI in the somata of the central nervous system, whereas the untreated sections were too weak to observe and analyse. The distribution of NOC-LI provides informative data for studies of the neuronal circuit that nociceptin may be involved in.

Electronic Resource

1365-2559

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Expression of intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 in human crescentic glomerulonephritisAims:  In glomerulonephritis, intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) may play important roles in the formation of crescents. These studies are designed to evaluate the expression patterns of ICAM-1 and VCAM-1 in human crescentic glomerulonephritis and to determine the cellular origin of adhesion molecules in the crescentic lesions.Methods and results:  We examined the expression of ICAM-1 and VCAM-1 proteins in renal biopsies with cellular (n=7), fibrocellular (n=9) or fibrous (n=4) crescentic glomerulonephritis, and six controls by immunohistochemistry. mRNA expression of ICAM-1 and VCAM-1 was further evaluated by RNA in-situ hybridization. Cytokeratin or CD68 immunohistochemistry was performed on the same sections, where in-situ hybridization had been carried out. In cellular crescents, ICAM-1 and VCAM-1 proteins were over-expressed to a similar extent. Of the three types of crescents, the extent of ICAM-1 immunopositivity was the greatest in the cellular crescents and decreased towards the fibrous crescents (P 〈 0.05). Yet the extent of VCAM-1 immunoreactivity was not different between the types. Fibrous crescents still contained some epithelial cells and showed only VCAM-1 expression. In the glomeruli with cellular or fibrocellular crescents, the extent of ICAM-1 immunopositivity in the glomerular tufts was significantly larger than that of VCAM-1 (P 〈 0.05). In an in-situ hybridization study, the mRNA expression patterns of ICAM-1 and VCAM-1 paralleled their protein expressions. A double-labelling study showed that the signal for ICAM-1 and VCAM-1 mRNAs was mainly present in cytokeratin-positive and CD68-negative cells in the crescentic lesions.Conclusions:  These results suggest that glomerular parietal epithelial cells in cellular crescents up-regulate both ICAM-1 and VCAM-1, and that some epithelial cells retained in fibrous crescents persistently over-express VCAM-1, but not ICAM-1. They also suggest that ICAM-1 is involved in early leucocyte recruitment into glomeruli in crescentic glomerulonephritis.

Electronic Resource

0014-5793

ATP synthase ; ATPase ; Escherichia coli ; Fluorotryptophan ; Glyphosate ; NMR

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Chemistry and Pharmacology

Physics

Electronic Resource

0009-2614

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Chemistry and Pharmacology

Physics

Electronic Resource

0009-2614

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Chemistry and Pharmacology

Physics

Electronic Resource

1574-6968

Blackwell Publishing Journal Backfiles 1879-2005

Biology

The acid phosphatase of an atypical Citrobacter sp. was purified in two isoforms, designated CPI and CPII, which had different Km values for glycerol 1-phosphate and glycerol 2-phosphate The enzyme was not inhibited by the end-product glycerol. Enzyme activity was increased in the presence of phosphate acceptor molecules having free hydroxyl groups (glycerol, methanol, ethanol). 31P-nuclear magnetic resonance spectroscopy indicated transfer of the liberated phosphate onto the alcohol, with the de novo production of (e.g.) glycerol 1-phosphate by enzyme supplemented with phosphomonoester substrate and glycerol.

Electronic Resource

1432-0584

Key words FVIII-B cDNA ; Retrovirus-mediated ; Transduction ; Partial hepatectomy ; Expression

Springer Online Journal Archives 1860-2000

Medicine

Abstract  A retrovius-mediated transduction of B-domain-deleted human blood coagulation factor VIII (FVIII-B) was attempted in partially hepatectomized rats. FVIII-B cDNA was inserted into a retroviral vector (pLNSX) and infective recombinant virus particles were produced in packaging cell lines (ψ2 and PA317). Transfection of mouse NIH-3T3 cells with the FVIII-B cDNA inserted recombinant viruses, followed by G418 selection, gave a viral titer of 3.5 × 104 CFU/ml. FVIII-B protein, as well as FVIII-B mRNA, was detected in these cells. Transfusion of FVIII-B-expressing retrovirus particles into the tail vein of rats subjected to partial hepatectomy resulted in a relatively higher level of FVIII-B expression in liver and circulating plasma as compared with the sham-operated rats. These results indicate that the augmentation of FVIII activity in the blood of an animal by retroviral gene delivery can be enhanced by partial hepatectomy, and that the retrovirus-mediated FVIII-B cDNA delivery to regenerating liver may be an alternative method for the expression of FVIII-B cDNA in vivo.

Electronic Resource

0942-0940

Keywords: Extra large vestibular schwannoma; prediction of facial nerve displacement; MRI.

Springer Online Journal Archives 1860-2000

Medicine

Summary  The primary objective in the surgery of extra large vestibular schwannoma is the total removal of the tumour mass while preserving the facial nerve. Preservation of the facial nerve in extra large tumours is reported as being notoriously difficult in the majority of cases  This study was undertaken to evaluate the accuracy in predicting displacement of the facial nerve by preoperative radiological imaging studies in 19 cases of extra large vestibular schwannoma. The direction of displacement of the facial nerve was predicted with preoperative axial and coronal MRI scans and verified intra-operatively.  We achieved total removal of tumours in 84.2%, facial nerve displacement was predicted in 80% and we accomplished anatomical preservation in 80%. Prediction of displacement was difficult in tumours with little or no intracanalicular components or with severe bony destruction of the internal acoustic meatus.  The preoperative prediction of facial nerve displacement in extra large tumours allows safe internal decompression of the tumour and careful dissection near the predicted area of the facial nerve during the operation. Consequently, a high rate of anatomical preservation of the facial nerve can be achieved.

Electronic Resource

1573-4811

Springer Online Journal Archives 1860-2000

Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics

Abstract Abstracts are not published in this journal

Electronic Resource

1439-863X

Key words Diel change ; Microcystis ; Nakdong River ; Vertical distribution

Springer Online Journal Archives 1860-2000

Biology

Abstract The vertical distribution of a bloom-forming Microcystis population was studied based on the relevant limnological parameters obtained from the lower Nakdong River (Mulgum) during the summer of 1994. Over three months (late June to late September), a high abundance of Microcystis population (mean ± SD, 2.9 ± 8.4 × 105 cells ml−1, n = 40) and algal biomass (mean ± SD, chlorophyll a, 131 ± 346 μg l−1, n = 31) was persistent throughout the entire water column (0–5 m, n = 11). The vertical distribution of carbon content was uneven, with a high concentration near the surface zone (mean ± SD, total, 7.9 ± 7.8; Microcystis, 5.2 ± 8.3 μg C ml−1, n = 15). Incorporating limnological and meteorological factors, a diel study of the vertical distribution of Microcystis showed that the chlorophyll a concentration was highest near the surface zone on a calm night (wind velocity, 〈2 m s−1, 2300–700) but was evenly distributed on a windy day (〉4 m s−1, 1100–1900). Among many possible factors, wind velocity may have played an important role in controlling the vertical distribution of Microcystis in the lower Nakdong River.

Electronic Resource

1573-4803

Springer Online Journal Archives 1860-2000

Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics

Abstract The precipitation behaviour of three Al–Mg–Si alloys has been studied by differential scanning calorimetry (DSC) and transmission electron microscopy. Seven exothermic peaks are usually observed in DSC thermograms of Al–Mg–Si alloys with high silicon contents. These peaks are believed to be caused by the formation of clusters of silicon and magnesium atoms, Guinier–Preston zones, small precipitates with an unknown structure, β″ phase, B′ phase, silicon precipitates and β phase. The silicon content has no obvious effect on the precipitation of β″ and B′ phases in these alloys, but it has a pronounced influence on the formation of silicon precipitates. The cold-rolling reduction before solution heat treatment is also found to affect the precipitation process appreciably.

Electronic Resource

0021-9304

cell culture ; CHO cells ; cellulose membrane ; phosphorylation ; cell aggregation ; Chemistry ; Polymer and Materials Science

Wiley InterScience Backfile Collection 1832-2000

Medicine

Technology

Phosphate groups (negatively charged chemical groups) were grafted onto the surface of cellulose membranes by a reaction between hydroxyl groups of cellulose and phosphorus pentoxide to observe the effect of phosphate groups on cellular behavior. X-ray photoelectron spectroscopy (XPS) was used to determine phosphorylation. Captive bubble contact angle measurement was used to determine surface wettability. XPS was also used to analyze serum protein adsorption. Chinese hamster ovary (CHO) cells were maintained in Ham's F-12 nutrient mixture with and without fetal calf serum. Total cell area and shape factor were analyzed using image-analyzing software. Serum proteins showed higher adsorption on phosphated cellulose. Cell spreading on phosphated membranes was greater than on the cellulose membrane that served as control. The cell growth rate was faster compared to the control. Large cell aggregates were not found on the phosphated membranes, in contrast to the control membrane. The cells on the control were aggregated regardless of the existence of divalent cations in the medium. © 1998 John Wiley & Sons, Inc. J Biomed Mater Res, 40, 401-406, 1998.

8 Ill.

Electronic Resource