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Purpose : This study was conducted to improve the performance of a low-end f-theta lens for application to laser scanning unit. Methods : A f-theta lens system was newly designed using ZemaxTM program. Results of this study were compared and evaluated in three items, such as spot diagram, ray fan, and Seidel aberrations. Results : The newly designed f-theta lens system reduced the spot size and distortion of the incident laser beam, and particularly its spherical aberration was drastically reduced up to 77%. Conclusion : The f-theta lens system designed in this study has greatly improved overall image quality and performance, and is expected to be applied to laser printer equipment.

Background Magnetic resonance imaging (MRI) of the spine is the preferred diagnostic tool for pathologic conditions affecting the spine. However, in patients receiving epidural corticosteroid injection (ESI) for treatment of spinal diseases, there is a possibility of misreading of MR images because of air or fluid in the epidural space after the injection. Therefore, we defined the characteristics of abnormal changes in MRI findings following an ESI in patients with low back pain. Methods We reviewed the medical records of 133 patients who underwent MRI of the lumbar spine within 7 days after ESI between 2006 and 2015.All patients were administered an ESI using a 22-gauge Tuohy needle at the lumbar spine through the interlaminar approach. The epidural space was identified by the loss of resistance technique with air. Results The incidences of abnormal changes in MRI findings because of ESI were 54%, 31%, and 25% in patients who underwent MRI at approximately 24 h, and 2 and 3 days after ESI, respectively. Abnormal MRI findings included epidural air or fluid, needle tracks, and soft tissue changes. Epidural air, the most frequent abnormal finding (82%), was observed in 41% of patients who underwent MRI within 3 days after injection. Abnormal findings due to an ESI were not observed in MR images acquired 4 days after ESI or later. Conclusions Pain physicians should consider the possibility of abnormal findings in MR images acquired after epidural injection using the interlaminar approach and the loss of resistance technique with air at the lumbar spine.

Spinal angiomyolipoma (AML) is a rare disease. It is often reviewed with spinal angiolipoma. Both are composed of vascular and mature adipose elements. However, only AML contains broader array of mesenchymal component. They are accounting for 0.14% to 1.2% of spinal tumors. They appear as fat containing hypervascular tumor located at epidural space of thoracic spine. Spinal AML is more frequently infiltrative and ofted occurs more ventrally than angiolipoma. Previous studies have employed conventional radiograph, myelogram, and CT scan for spinal AML studies. Recently, MRI has been used for spinal AML in a few studies. Here, we describe a case of typical thoracic spinal AML with a review of its MRI findings and other differential diagnosis for epidural spinal mass with similar characteristics.

In order to simulate the performance of chemical looping combustion (CLC) of pure methane in a continuous bubbling fluidized bed process using a NiO-based oxygen carrier under various operating conditions, this study has developed a mathematical model based on the reaction kinetics and population balance of oxygen carrier (OC) particles in each reactor. Proper operating conditions have been discussed for complete combustion of methane. The minimum OC circulation rate for complete combustion was determined with the variation of temperature and fuel bed mass. The methane combustion efficiency was strongly affected by the distribution of OC between the air reactor (AR) and fuel reactor (FR) at a constant temperature, circulation rate of OC, and total bed mass. The range of OC distribution possible to achieve complete combustion became wider with increasing either the temperature or the circulation rate of OC at a constant total bed mass. In tested conditions of a lab-scale process, the range on the OC mass r...

We developed a mathematical model to discuss the performance of chemical looping combustion (CLC) of methane in continuous bubbling fluidized-beds. The model considers the particle population balance, oxidation and reduction rate of particles in fluidized beds. It also considers utilization efficiency of oxygen carrier (OC) particles, residence time of particles in each reactor, and particle size in reaction rate. The model was applied for a bubbling coreannulus fluidized-bed process. The core bed was the fuel reactor (0.08 m-i.d., 2.1 m-height) and the annulus bed was the air reactor (0.089 m-i.d., 0.15 m-o.d., 1.6 m-height). The process employed a type of Ni-based OC particles. The present model agrees reasonably well with the combustion efficiency measured in the process. Simulation was performed to investigate the effects of some variables for the process. The present model revealed that the range of circulation rate of OC particles for achieving complete combustion determined the operating range of the CLC system. The minimum circulation rate of OC particles for complete combustion decreased in the considered operating range as temperature or bed mass increased in the fuel reactor. A large mass of the fuel bed was necessary to obtain complete combustion at low fuel reactor temperature. The fresh feed rate of OC particles for steady state operation increased in complete combustion condition as temperature or static bed height or gas velocity increased.

The present study examined 469 commercially available fermented alcoholic beverages (FABs), including beer (draft, microbrewed, and pasteurized), fruit wine (grape and others), refined rice wine, and yakju (raw and pasteurized). Samples were screened for Escherichia coli and eight foodborne pathogens (Bacillus cereus, Campylobacter jejuni, Clostridium perfringens, Escherichia coli O157:H7, Listeria monocytogenes, Salmonella spp., Staphylococcus aureus, and Yersinia enterocolitica), and the aerobic plate count, lactic acid bacteria, acetic acid bacteria, fungi, and total coliforms were also enumerated. Microbrewed beer contained the highest number of microorganisms (average aerobic plate count, 3.5; lactic acid bacteria, 2.1; acetic acid bacteria, 2.0; and fungi, 3.6 log CFU/ml), followed by draft beer and yakju (P < 0.05), whereas the other FABs contained , 25 CFU/25 ml microorganisms. Unexpectedly, neither microbial diversity nor microbial count correlated with the alcohol content (4.7 to 14.1%) or pH (3.4 to 4.2) of the product. Despite the harsh conditions, coliforms (detected in 23.8% of microbrewed beer samples) and B. cereus (detected in all FABs) were present in some products. B. cereus was detected most frequently in microbrewed beer (54.8% of samples) and nonpasteurized yakju (50.0%), followed by pasteurized yakju (28.8%), refined rice wine (25.0%), other fruit wines (12.3%), grape wine (8.6%), draft beer (5.6%), and pasteurized beer (2.2%) (P < 0.05). The finding that spore-forming B. cereus and coliform bacteria can survive the harsh conditions present in alcoholic beverages should be taken into account (alongside traditional quality indicators such as the presence of lactic acid-producing bacteria, acetic acid-producing bacteria, or both) when developing manufacturing systems and methods to prolong the shelf life of high-quality FAB products. New strategic quality management plans for various FABs are needed.

Niemann-Pick disease type C (NPC) is a fatal autosomal recessive cholesterol disorder characterized by severe progressive neurodegeneration. To unveil the mechanism of neurodegeneration, proteomic and morphological approaches were applied to the hippocampus in NPC -/- mouse. Two-DE was utilized to resolve the hippocampal protein expression profiles of 4- and 8-week-old NPC +/+ and -/- mice. Differentially expressed protein spots were identified by MALDI-TOF MS and database searching. At 4 weeks of age, there was no significant difference in protein profiles between NPC +/+ and -/- mice. However, at the age of 8 weeks, NPC +/+ and -/- mice showed marked difference in protein expressions. Among these, glutamate receptor 2 precursor was identified. The immunohistochemical study on neurotransporters showed that glial GABA transporter (GAT-3) increased in both 4- and 8-week-old NPC -/- mouse and glutamic acid decarboxylase (GAD-6) increased in 8-week-old NPC -/- mouse. Glial glutamate transporter, excitatory amino acids carrier-1 (EAAC1), decreased in 8-week-old NPC -/- mouse. In conclusion, our data may provide insight into the understanding of the basic mechanism through perturbation of protein networks and neurotransporter systems in a single gene knockout model of NPC disease.

Protein Network Research Center, Yonsei University, Seoul 120-749, KoreaReceived August 16, 2001Berberine and berberrubine, which display antitumor activity, have also demonstrated distinct enzyme-poisoning activities by stabilizing topoisomerase II-DNA cleavable complexes. The protoberberineberberrubine differs in chemical structure with berberine at only one position, however, it shows a prominentactivity difference from berberine. Solution structures of berberine and berberrubine determined by NMRspectroscopy are similar, however, the minor structural rearrangement has been observed near 19 methoxy orhydroxyl group. We suggest that the DNA cleavage activities of topoisomerase II poisons could be correlatedwith both chemical environments and minor structural change together with hydrophobicity of interacting sidechains of drugs with DNA molecule.Keywords : Berberine, Berberrubine, Anti-tumor drug, ROESY, NMR.IntroductionOne of the most important molecular targets for anti-tumor drugs is DNA topoisomerase II, which forms acovalent linkage to both strands of the DNA helix bybreaking and resealing the sugar-phosphate backbone bondsof DNA.

1Radiology, 2 Neurology, and 3 Objective: Although the detection of crossed cerebellar diaschisis (CCD) by means of different imaging modalities is well described, little is known about its diagnosis by computed tomography perfusion (CTP) imaging. We investigated the detection rate of CCD by CTP imaging and the factors related to CCD on CTP images in patients with acute ischemic stroke. Materials and Methods: CT perfusion maps of cerebral blood volume (CBV), cerebral blood flow (CBF), mean transit time (MTT), and time-to-peak (TTP) obtained from 81 consecutive patients affected by an acute ischemic stroke were retrospectively reviewed. Whole-brain perfusion maps were obtained with a multichannel CT scanner using the togglingtable technique. The criteria for CCD was a unilateral supratentorial ischemic lesion and an accompanying decrease in perfusion of the contralateral cerebellar hemisphere on the basis of CTP maps by visual inspection without a set threshold. Maps were quantitatively analyzed in CCD positive cases. Results: The criteria for CCD were fulfilled in 25 of the 81 cases (31%). Detection rates per CTP map were as follows: MTT (31%) > TTP (21%) > CBF (9%) > CBV (6%). Supratentorial ischemic volume, degree of perfusion reduction, and infratentorial asymmetry index correlated strongly (R, 0.555-0.870) and significantly ( p < 0.05) with each other in CCDpositive cases. Conclusion: It is possible to detect CCD on all four of the CTP-based maps. Of these maps, MTT is most sensitive in detecting CCD. Our data indicate that CTP imaging is a valid tool for the diagnosis of CCD in patients affected by an acute hemispheric stroke. Index terms: Crossed cerebellar diaschisis; Acute stroke; CT perfusion