Search PubMed⌕ Search

Biomedical subjects

B J Kim

Publications and source records attributed to B J Kim.

At least 19 recordsLinked to original sources
PubMed2006

Complete ophthalmoplegia after herpes zoster.

Motor loss caused by herpes zoster is infrequent, and only a few studies have focused on ocular motor paralysis in ophthalmic herpes zoster. We report a case of complete ophthalmoplegia resulting from ophthalmic herpes zoster. A 69-year-old man presented with complete left-side ptosis with total ophthalmoplegia 7 days after the onset of left ophthalmic herpes zoster. The patient was treated with aciclovir and prednisolone. Five months later, the ptosis had resolved and the extraocular motility had almost returned to normal.

Acyclovir↗
PubMed2006

Missing xy-band Fermi surface in 4d transition-metal oxide Sr2RhO4: effect of the octahedra rotation on the electronic structure.

Electronic structures of the 4d transition-metal oxide compound Sr2RhO4 are investigated by angle-resolved photoemission spectroscopy and density-functional electronic structure calculations. In the measured Fermi surfaces (FS) of Sr2RhO4, the xy-band FS sheet expected from the well-established results of the FS of Sr2RuO4 is missing, the volume of which should be different only by one additional electron for Sr2RhO4. The apparent contradiction is resolved by a careful analysis of the band structure where the rotation of octahedra results in the hybridization of e(g) and t(2g) states and thus plays a key role in the determination of the electronic structure near EF. The modification of the FS structure due to the distorted lattice is related to the charge transfer among the orbital states and suggested to be relevant to the metal-insulator transition in Ca(2-x)Sr(x)RuO4.

Journal Article↗
PubMed2006

Magnetic resonance imaging of Asians with multiple sclerosis was similar to that of the West.

Magnetic resonance imaging (MRI) of the brain is the most important paraclinical diagnostic test in multiple sclerosis (MS). The appearance of MRI in Asians with MS is not well defined. We retrospectively surveyed the first brain and spinal cord MRI in patients diagnosed to have MS, according to Poser's criteria in seven regions throughout Asia to define the MRI changes among Asians with MS. There were 101 patients with first brain, and 86 with first spinal cord MRI, 66 of whom had both. The brain MRI showed a mean of 17 lesions per patient in T2 weighted images, mostly asymptomatic. Almost all the lesions were in the white matter, particularly in the juxtacortical, deep and periventricular white matter. A third of the lesions were greater than 5 mm, 14% enhanced with gadolinium. There were more supratentorial than infratentorial lesions at a ratio of 7.5: 1. Ninety five percent of the spinal cord lesions were in cervical and thoracic regions, 34% enhanced with gadolinium. The lesions extended over a mean of 3.6 +/- 3.3 vertebral bodies in length. Fifty (50%) of the brain and 54 (63%) of the spinal MRI patients had the optic-spinal form of MS. The MRI of the optic-spinal and classical groups of patients were similar in appearance and distribution, except that the optic-spinal MS patients have fewer brain but longer and more severe spinal cord lesions. In conclusion, the brain and spinal cord MRI of Asian patients with MS was similar to that of the West, although, in this study, Asian MS patients had larger spinal cord lesions.

Adult↗
PubMed2006

Ethnic characteristics of eyelashes: a comparative analysis in Asian and Caucasian females.

BACKGROUND: Despite similar biochemical composition of human hair between races, physico-morphological characteristics are not identical in different ethnic groups. Eyelashes have been investigated far less than scalp hair, and the information available is insufficient. OBJECTIVES: To obtain basic information about eyelashes and to clarify differences between female eyelashes in Asians and Caucasians. METHODS: Twenty Asian and 10 white Caucasian female volunteers aged between 20 and 29 years were admitted to the study. Lateral digital photographs of upper eyelashes were taken and curl-up and lift-up angles of upper eyelashes were measured from lateral views. Images of upper eyelashes were also taken using the phototrichogram technique and total numbers, lengths and thicknesses of upper eyelashes were obtained (a total of 4661 eyelashes; 2946 for Asian, 1715 for Caucasian). The central portion of the eyelashes or whole eyelashes were clipped and images were taken immediately and 7 days later to obtain the growth rate and anagen ratio of upper eyelashes. Numbers and thickness of eyelash cuticular layers were obtained by electron microscopy. RESULTS: Compared with Caucasians, Asian eyelashes revealed lower lift-up and curl-up angles, fewer numbers and a thicker transverse diameter. However, no statistical difference was observed in length or growth rate. Duration of anagen was estimated at about 2 months. The eyelash anagen ratio obtained from five Asians was 17.8 +/- 3.3%. By electron microscopy, the number of cuticular layers in transverse section was greater in Asian (8.0 +/- 1.2) than Caucasian females (6.5 +/- 1.1), but no statistical difference was found in single cuticle layer thickness between the two groups. Moreover, eyelash characteristics were not influenced by eye makeup in either race. CONCLUSIONS: Our results on eyelash morphology and growth characteristics demonstrated significant ethnic differences in Asian and Caucasian females that could provide basic information for future investigations.

Adult↗
PubMed2006

Zero-valent iron treatment of RDX-containing and perchlorate-containing wastewaters from an ammunition-manufacturing plant at elevated temperatures.

The use of zero-valent iron for treating wastewaters containing RDX and perchlorate from an army ammunition plant (AAP) in the USA at elevated temperatures and moderately elevated temperature with chemical addition was evaluated through batch and column experiments. RDX in the wastewater was completely removed in an iron column after 6.4 minutes. Increasing the temperature to 75 degrees C decreased the required retention time to 2.1 minutes for complete RDX removal. Perchlorate in the wastewater was completely removed by iron at an elevated temperature of 150 degrees C in batch reactors in 6 hours without pH control. Significant reduction of perchlorate by zero-valent iron was also achieved at a more moderate temperature (75 degrees C) through use of a 0.2 M acetate buffer. Based on the evaluation results, we propose two innovative processes for treating RDX-containing and perchlorate-containing wastewaters: a temperature and pressure-controlled batch iron reactor and subsequent oxidation by existing industrial wastewater treatment plant; and reduction by consecutive iron columns with heating and acid addition capabilities and subsequent oxidation.

Explosive Agents↗
PubMed2005

Postural control and detection of slip/fall initiation in the elderly population.

One of the common causes of morbidity and mortality in workplaces is related to slips or falls. Reaction to external disturbances, such as slips or falls, requires a process of perturbation detection and control of motion changes. Postural control is a common mechanism to compensate unexpected displacements of the body. The ability of postural control diminishes with ageing or neuropathy. In this study, two controlled groups, diabetics and non-diabetics in the elderly population, were investigated to compare how different postural control mechanisms would relate to the detection of perturbation and regain of balance. The ultra-low-vibration Sliding Linear Investigative Platform for Analyzing Lower Limb Stability SYSTEM was used to measure the biomechanical changes of posture and perturbation detection. In phase 1 of the analysis, static measures during quiet standing were considered to investigate the relationship between postural stability and perturbation detection capability. In phase 2 of the analysis, dynamic measures during an occurrence of perturbation were analysed. Statistical tests and linear logistic regression models were applied to find differences of postural control mechanisms and to build a predictive model for perturbation detection quantitatively. It is anticipated that the results of this study will contribute to more comprehensive understanding of postural control mechanisms and design of slip/fall prevention programmes.

Acceleration↗
PubMed2005

Lesional location of lateral medullary infarction presenting hiccups (singultus).

BACKGROUND: Hiccups are an infrequent result of lateral medullary infarction. Their importance may be underestimated and they can cause distress, exhaustion, and aspiration. Hiccups in lateral medullary infarction remain poorly understood OBJECTIVE: To evaluate the relation between the lesional loci of lateral medullary infarction and hiccups. METHODS: 51 patients with lateral medullary infarction were investigated by magnetic resonance imaging within three days of the onset of infarction. Seven of the 51 patients developed hiccup. RESULTS: All patients with hiccups had middle level lateral medullary lesions, including two with lower level lesions and four with upper level lesions. In the middle level lateral medullary lesions, dorsolateral lesions were most often involved. All patients with lateral medullary infarction presenting with hiccups also had vertigo, dizziness, nausea, vomiting, and dysphagia. CONCLUSIONS: The observations suggest that middle level and dorsolateral lesion locations in lateral medullary infarction frequently induce hiccups.

Adult↗
PubMed2004

Cognitive abilities in driving: differences between normal and hazardous situations.

This study investigated the relationship between cognitive abilities and driving behaviour in situations of normal driving and hazardous driving. For driving behaviour, driving component skills were measured from two different types of driving situations such as normal driving situations and hazardous driving situations. Normal driving skills were evaluated through an on-street driving test, where search, speed control, and direction control were considered as driving component skills. Hazardous driving component skills were evaluated using a standardized video driving paradigm. Component skills that were evaluated in this paradigm were search, identify, predict, decide, and execute. A battery of predictive tests was administered to the participants. Forty-two students from high schools participated in this study. Analysis of multiple regression implied that the measure of dynamic visual signal perception introduced to this study could be used as a predictor of driving performance for both situations. Driving component skills showed different effects between normal situations and hazardous situations.

Accidents, Traffic↗
PubMed2004

Search for electron neutrino appearance in a 250 km long-baseline experiment.

We present a search for electron neutrino appearance from accelerator-produced muon neutrinos in the K2K long-baseline neutrino experiment. One candidate event is found in the data corresponding to an exposure of 4.8 x 10(19) protons on target. The expected background in the absence of neutrino oscillations is estimated to be 2.4+/-0.6 events and is dominated by misidentification of events from neutral current pi(0) production. We exclude the nu(micro) to nu(e) oscillations at 90% C.L. for the effective mixing angle in the 2-flavor approximation of sin((2)2theta(microe)( approximately 1/2sin((2)2theta(13))>0.15 at Deltam(2)(microe)=2.8 x 10(-3) eV(2), the best-fit value of the nu(micro) disappearance analysis in K2K. The most stringent limit of sin((2)2theta(microe)<0.09 is obtained at Deltam(2)(microe)=6 x 10(-3) eV(2).

Journal Article↗
PubMed2004

Expression of the intermediate filament vimentin in proliferating duct cells as a marker of pancreatic precursor cells.

OBJECTIVES: The expression of the intermediate filament (IF) vimentin, usually considered a marker of mesenchymal cells, has been observed in the epithelial cells during embryogenesis, carcinogenesis, and dedifferentiation, suggesting that it might be useful as a marker of proliferating precursor cells in the pancreas. METHODS: Rat pancreata at E18 and at different time points after partial pancreatectomy (Px) and human and neonatal pig pancreatic tissue sections and monolayer cultured pancreatic duct cells were observed. All tissues were simultaneously immunostained with pancytokeratin and vimentin antibodies. In costained duct cells, PDX-1 or PCNA expression was also analyzed using confocal microscope images. RESULTS: In the rat embryonic pancreas at E18, all epithelial cells that formed ductlike structures expressed both cytokeratin and vimentin IF, whereas no duct cells costained for IF in the adult rat or neonatal pig pancreas. Such costaining reappeared in the following order: common pancreatic duct, main ducts, foci of regeneration and then disappeared completely at 30 days after Px. In humans, costaining was found in only 1 diabetic patient's pancreatic section, which was accompanied by massive duct cell proliferation. In monolayer culture, most of the duct cells of human and neonatal pigs coexpressed both IF proteins. Only a few costained duct cells also expressed PDX-1, and most of those cells were also stained with PCNA in rat embryonic pancreas and regenerating foci after partial Px. CONCLUSIONS: Vimentin IF expression might be a useful marker for pancreatic precursor cells and could be used to investigate the concept of the dedifferentiation of fully matured duct cells during the process of the beta-cell neogenesis.

Animals↗
PubMed2004

Conceptual comparison of pink water treatment technologies: granular activated carbon, anaerobic fluidized bed, and zero-valent iron-Fenton process.

Pink water, explosive-laden wastewater produced in army ammunition plants is often treated using expensive and non-destructive granular activated carbon (GAC) adsorption. This paper compares GAC adsorption and two alternative treatment technologies, anaerobic GAC fluidized bed reactor and zero-valent iron-Fenton process. The bench-scale demonstration of the zero-valent iron-Fenton process with real pink water is reported. The features of three technologies are compared and their advantages and drawbacks are discussed.

Adsorption↗
PubMed2003

Indications of neutrino oscillation in a 250 km long-baseline experiment.

The K2K experiment observes indications of neutrino oscillation: a reduction of nu(mu) flux together with a distortion of the energy spectrum. Fifty-six beam neutrino events are observed in Super-Kamiokande (SK), 250 km from the neutrino production point, with an expectation of 80.1(+6.2)(-5.4). Twenty-nine one ring mu-like events are used to reconstruct the neutrino energy spectrum, which is better matched to the expected spectrum with neutrino oscillation than without. The probability that the observed flux at SK is explained by statistical fluctuation without neutrino oscillation is less than 1%.

Journal Article↗
PubMed2003

The trade-offs and effect of carrier size and oxygen-loading on gaseous toluene removal performance of a three-phase circulating-bed biofilm reactor.

We conducted a series of steady-state and short-term experiments on a three-phase circulating-bed biofilm reactor (CBBR) for removing toluene from gas streams. The goal was to investigate the effect of macroporous-carrier size (1-mm cubes versus 4-mm cubes) on CBBR performance over a wide range of oxygen loading. We hypothesized that the smaller biomass accumulation with 1-mm carriers would minimize dissolved-oxygen (DO) limitation and improve toluene removal, particularly when the DO loading is constrained. The CBBR with 1-mm carriers overcame the performance limitation observed with the CBBR with 4-mm carriers: i.e., oxygen depletion inside the biofilm. The 1-mm carriers consistently gave superior removal of toluene and chemical oxygen-demand, and the advantage was greatest for the lowest oxygen loading and the greatest toluene loading. The 1-mm carriers achieved superior performance because they minimized the negative effects of oxygen depletion, while continuing to provide protection from excess biomass detachment and inhibition from toluene.

Air Pollutants↗
PubMed2003

Photoplastic near-field optical probe with sub-100 nm aperture made by replication from a nanomould.

Polymers have the ability to conform to surface contours down to a few nanometres. We studied the filling of transparent epoxy-type EPON SU-8 into nanoscale apertures made in a thin metal film as a new method for polymer/metal near-field optical structures. Mould replica processes combining silicon micromachining with the photo-curable SU-8 offer great potential for low-cost nanostructure fabrication. In addition to offering a route for mass production, the transparent pyramidal probes are expected to improve light transmission thanks to a wider geometry near the aperture. By combining silicon MEMS, mould geometry tuning by oxidation, anti-adhesion coating by self-assembled monolayer and mechanical release steps, we propose an advanced method for near-field optical probe fabrication. The major improvement is the possibility to fabricate nanoscale apertures directly on wafer scale during the microfabrication process and not on free-standing tips. Optical measurements were performed with the fabricated probes. The full width half maximum after a Gaussian fit of the intensity profile indicates a lateral optical resolution of approximately 60 nm.

Aluminum↗
PubMed2003

Enhancing oxidation of TNT and RDX in wastewater: pre-treatment with elemental iron.

Munitions manufacturing wastewater is commonly treated by adsorption to activated carbon. We are proposing a new munitions manufacturing wastewater treatment system consisting of a reductive pre-treatment process and subsequent Fenton's oxidation to mineralize energetic compounds such as TNT and RDX. The pre-treatment involves reduction of electron-withdrawing nitro groups of TNT and RDX with elemental iron. The iron-treated explosives are then oxidized by Fenton's reagent through the addition of H2O2. The objective of this work is to investigate the feasibility of using elemental iron to convert TNT and RDX to reduction products which may be more oxidizable in subsequent Fenton's oxidation. Results of batch reduction experiments with elemental iron showed complete removal of TNT and RDX and formation of the reduction products within 60 minutes. Results of column experiments showed a rapid and complete removal of TNTand RDX within 9.7 minutes retention time. Fitting observed effluent concentrations to a one-dimensional advection-dispersion equation, we were able to predict the concentration profiles of TNT and RDX in the iron column and calculate the iron column length required for the desired removal. The results of Fenton's oxidation experiments showed that iron pre-treatment enhanced both the rate and extent of TNT and RDX mineralization by Fenton's oxidation.

Adsorption↗