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BACKGROUND: Rapid diagnosis of drug-resistant TB is critical for early initiation of effective therapy. YD Diagnostics in South Korea recently developed the MolecuTech® REBA MTB-XMDR test to rapidly detect multidrug-resistant TB (MDR-TB), pre-extensively drug-resistant TB (pre-XDR-TB) and resistance to second-line injectable drugs (SLIDs) simultaneously using a fully automated test platform. This study aimed to evaluate the MolecuTech® test for the detection of MDR- and pre-XDR-TB, as well as SLID resistance.METHODS: A total of 151 clinical Mycobacterium tuberculosis isolates from South Korea were tested using the MolecuTech test, and the results were analysed by comparing these with phenotypic drug susceptibility testing (pDST) and sequencing.RESULTS: Compared to pDST, the MolecuTech test showed a sensitivity and specificity of respectively 97.7% and 100.0% for rifampicin (RIF), 82.4% and 100.0% for isoniazid (INH), 97.5% and 97.2% for fluoroquinolones (FQs), and 94.0% and 98.8% for SLIDs. Concordances with the sequencing results of each resistance determinant were 99.3% for RIF, 96.7% for INH, 98.7% for FQs and 99.3% for SLIDs.CONCLUSION: The MolecuTech test is an efficient and reliable rapid molecular diagnostic tool for the simultaneous screening of MDR- and pre-XDR-TB.

This study deals with the simplex optimization of a shield coil geometry for improving the magnetic shielding performance of fully air-cored superconducting generators. The superconducting generator in this study has a 10 MW-3000 rpm class, fully air-cored, rotating armature structure designed for electric propulsion aircraft applications. The magnetic flux radiated to the outside of the machine is shielded by the shield coil, and the shielding performance is determined by the shape of the shield coil. In this study, the design of the shield coil is developed using simplex optimization to improve the shield performance. The shape optimization is conducted using the simplex optimal design method, and the validity of the designed shield coil is verified by comparing the shielding performance of the initial and the optimized models.

Herein, we report our experience of performing allogeneic orthotopic liver transplantation (LT) in nonhuman primates. We designed an allogeneic ABO-compatible orthotopic LT model in monkeys in a manner similar to that used in humans. We applied almost the same surgical procedures used for human conventional deceased donor LT. A total of 6 monkeys underwent allogeneic LT. One cynomolgus monkey aged 45 months (3.4 kg) and 5 rhesus macaque monkeys aged 50.2 ± 14.8 months (5.40 ± 0.33 kg) were used as recipients. In the donor surgery, the liver was perfused in situ through the aorta using cold histidine-tryptophan-ketoglutarate solution. The portal vein (diameter, 5-10 mm), supra- and infra-hepatic inferior vena cava (IVC) (diameter, 12-15 mm), and common bile duct (diameter, 1.5-3.0 mm) were dissected out. The hepatic artery was kept in continuity with the celiac trunk and abdominal aorta up to the iliac bifurcation (diameter, 5-6 mm). The mean graft weight was 102.0 g (94.8-111.0 g). Recipient surgery was conducted in parallel. After recipient hepatectomy, the graft was implanted. The suprahepatic IVC and portal vein were anastomosed to those of the graft. After reperfusion, the infrahepatic IVC was anastomosed. The aorta conduit of the graft was anastomosed to the infrarenal aorta of the recipient in a retrocolic end-to-side manner. Biliary reconstruction was performed in a duct-to-duct anastomosis with cholecystectomy. Mean operative time was 107.0 minutes for donor and 198.2 minutes for recipient. There was one operative death due to unknown cause. In conclusion, for allogeneic orthotopic LT in nonhuman primate model, we can apply almost the same procedure used for human conventional deceased donor LT in a similar manner.

We propose a new experiment on the site of the Korea Atomic Energy Research Institute (KAERI) located at Daejeon, Korea. The Hanaro short baseline (SBL) nuclear reactor with a thermal power output 30 MW is used to investigate a reactor neutrino anomaly. A Hanaro SBL prototype detector having a 60-l volume has been constructed ∼6 m away from the reactor core. A gadolinium (Gd)-loaded liquid scintillator (LS) is used as an active material to trigger events. The selection of the LS is guided by physical and technical requirements, as well as safety considerations. A linear alkyl benzene (LAB) is used as a base solvent of the Hanaro SBL prototype detector. Three g/l of PPO and 30 mg/l of bis-MSB are dissolved to formulate the LAB-based LS. Then, a 0.5% gadolinium (Gd) complex with carboxylic acid is loaded into the LAB-based LS by using the liquidliquid extraction method. In this paper, we will summarize all the characteristics of the Gd-loaded LAB-based LS for the Hanaro prototype detector.

Reactor experiment for neutrino oscillation (RENO) began data-taking from August 2011. It successfully observed reactor antineutrino disappearance in April 2012 to measure the smallest mixing angle of θ 13 . Two identical detectors, one at near location and the other at far location, are constructed at the Yonggwang nuclear power plant in South Korea, to compare the observed reactor neutrino fluxes. Each RENO detector is filled with 16 mass tons of Gadolinium loaded liquid scintillator (GdLS) in the neutrino target region, and with 28 mass tons of unloaded liquid scintillator (LS) in the γ - catcher region surrounding the target. LS was developed to satisfy chemical, physical, optical properties, and safety requirements. Linear alkyl benzene (LAB) was chosen as a solvent because of its high flash-point, sufficient light yield, and being environmentally friendly. GdLS is carefully developed to keep a long attenuation length and high light yield for a long time period. In this paper, we report the characteristics and mass production of the RENO LS and GdLS.

The dosimetric properties of the newly developed thermoluminescence (TL) material (LiF:Mg,Cu,Si) at Korea Atomic Energy Research Institute (KAERI) were investigated. The energy response of the detector was performed for photon energies from 20 to 662 keV. The dose response for this TL material (LiF:Mg,Cu,Si) was linear up to 10 Gy and a sub-linear response was observed for higher doses. The reusability of this newly developed TL detector sufficiently satisfied IEC standards. Detection threshold of LiF:Mg,Cu,Si TL material was investigated and found to be 930 nGy by Harshaw 4500 TLD reader. © 2013 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.doi: http://dx.doi.org/10.3329/jsr.v5i1.11935 J. Sci. Res. 5 (1), 25-31 (2013)

In order to understand the scintillation characteristics of nuclear recoil events in CsI(Tl) crystals and for application to the analysis of Dark Matter (DM) searches, we study quenching and channeling effects with simulations of recoil ion motion in CsI(Tl) and experiments using neutrons impinging on the crystal. The electronic energy loss versus penetration depth of recoil ions in a CsI(Tl) target are simulated by the SRIM and MARLOWE programs and modified by the application of a measured scintillation efficiency function. They are used to produce quenching factors as a function of recoil energy. The application of the MARLOWE code to a monocrystalline target yields a light yield distribution including tails which are correlated with ions' enhanced ranges. The 2.4 MeV pulsed neutrons impinging on a monocrystalline CsI(Tl) target and an array of neutron detectors located at different scattering angles are used to measure the light yield distribution and the status of the measurement is reported.

Scintillation properties and radioactive contamination of calcium molybdate scintillating crystals depleted in 48Ca and enriched in 100Mo (40Ca100MoO4 ) have been studied to prepare a 100Mo-based neutrinoless double beta decay experiment. The prospects of a neutrinoless double beta decay experiment using 40Ca100MoO4 crystals are discussed.

The search for neutrinoless double beta decay (0 νββ ) is a key experiment for evaluating the mass of the neutrino and for determining the Majorana/Dirac nature of neutrinos. A scintillating CaMoO 4 crystal is a good material for use in investigating 0 νββ with cryogenic detectors. The high transition energy ( Q = 3034 keV) and nearly 10% natural abundance of 100 Mo, together with the scintillating property of the crystal, provide favorable conditions to search for 0 νββ of 100 Mo. We report a prototype experiment operating at low temperatures using a CaMoO 4 crystal as a particle absorber. Prior to testing of isotopically-enriched 40 Ca 100 MoO 4 crystals, a CaMoO 4 crystal with Mo of natural isotopic composition was tested. Using a metallic magnetic calorimeter as a temperature sensor, we achieved high energy resolutions for alpha particles and low-energy gamma rays. This experiment shows the feasibility of scaling up the crystal size to perform a high sensitivity search for 0 νββ decay of 100 Mo.

BACKGROUND AND PURPOSE: Methylation of the MGMT gene promoter is associated with a favorable prognosis in adult patients with GBM treated with TMZ. We determined the incidence of pseudoprogression according to the MGMT methylation status and the potential value of DSC perfusion MR images for predicting pseudoprogression. MATERIALS AND METHODS: New or enlarged enhancing lesions after CCRT in adult patients with newly diagnosed GBMs were prospectively assessed by measuring their rCBV by using DSC perfusion MR images. Tumor tissue was assayed to determine MGMT promoter methylation status. All patients were regularly followed up at an interval of 2 months by MR images, including DSC perfusion MR images. RESULTS: Ninety eligible patients were enrolled in this study. After CCRT, new or enlarged enhanced lesions were found in 59 of 90 patients, which were subsequently classified as pseudoprogression (26 patients, 28.9%) and real progression (33 patients, 36.7%). Overall, there was a significant difference in the mean rCBV between pseudoprogression and real tumor progression ( P = .003). The ROC curve revealed that an rCBV ratio >1.47 had an 81.5% sensitivity and a 77.8% specificity. The unmethylated MGMT promoter group had a significant difference of mean rCBV between pseudoprogression and real progression ( P = .009), though the methylated MGMT promoter group had no significant difference ( P = .258). CONCLUSIONS: The current study suggests that rCBV measured by DSC perfusion MR images has a differential impact on the predictability of pseudoprogression in patients with GBM.

The nonpoint source (NPS) control facilities as best management practices (BMPs) were installed to manage NPS pollution in Korean and determining the pollutant reduction loads of BMPs is important to abide by the Korean total maximum daily load (TMDL). However, there are some inadequacies in the methodology to estimate the NPS reduction loads because of uncertainties in rainfall and runoff characteristics. For that reason, a Storm water management model (SWMM) model was used to eliminate uncertainties and to estimate more appropriate reduction loads. In this study, the annual total reduction load (ATRL) method was suggested to calculate annual reduction loads using a SWMM model for appropriate NPS pollution control in the TMDL. Also regression of EMCs (ROE) method was suggested to calculate the annual average removal efficiency (RE) compared to the four different methods, namely, the efficiency ratio (ER), summation of loads (SOL), regression of loads (ROL), and rainfall of frequency method (ROF). Therefore, the ROE method was suggested as the appropriate method to determine the average REs of the BMPs. Also the ATRL method was suggested as the appropriate method to determine the reduction load compared to the existing method in the Korean TMDL. This study provides a SWMM model to standardize BMPs data analysis. The SWMM model can be used to determine the RE and reduction loads of NPS pollution due to the implementation of BMPs and to complement their uncertainties in the TMDL.

Search for neutrino-less double beta decay of 100Mo is proposed using active method with Ca 100MoO4 scintillation crystals which show the brightest scintillation light among variety of inorganic scintillation materials containing Mo. Study of X-ray luminescence and scintillation properties such as energy response, number of photoelectrons/keV, absolute light yield, decay time, pulse shape discrimination and radioactive contamination of CaMoO4 crystals grown by the Czochralski method with different conditions are presented. Further R&D of resolution optimization, crystal quality improvement and background reduction are underway. Significant improvement of sensitivity to neutrino-less double beta decay can be achieved by using 10 Mo enriched Ca 100MoO4 crystals with good energy resolution and low background. Further reduction of background induced by 48 Ca two neutrino double beta decay can be achieved by using 48Ca depletion. We are planning to install several kilograms of Ca 100MoO4 crystals depleted in 48Ca at underground laboratory for the neutrino-less double beta decay experiment in the near future.

A search for the neutrinoless double-beta decay of 124 Sn was carried out using the tin-loaded liquid scintillator for an active source-detector technique. Tin (32.6%) in weight was successfully loaded into the liquid scintillator, and light output was as high as 57% of the unloaded liquid scintillator. A tin-loaded liquid scintillator with 1.1 l volume was installed at the 700 m underground laboratory in YangYang, and data were taken for 5285 h. No evidence for the 0 ν β β decay was found and a lower limit on the 124 Sn half-life was obtained to be 2.0 × 10 19 year with 90% C.L. The new limit represents a significant improvement with respect to those previously available for 124 Sn .

We investigated bioadhesion (bacterial and cell adhesion) and biocompatibility of poly(tetrafluoroethylene-co-perfluoro-3,6-dioxa-4-methyl-7-octenesulfonic acid) (Nafion) and compared the results with those obtained with poly(vinylidene fluoride-co-hexafluoropropylene) (PVFHFP). When incubated with bacteria for 4 h to 7 days, Nafion film exhibited scarce bacterial adhesion at 6 h, after which the adhesion gradually increasing to relatively low levels. In contrast, significant bacterial adhesion to PVFHFP film was observed at 4 h, and much higher adhesion levels were shown thereafter. Although HEp-2 human cells adhered normally to both films, reaching confluence in 7-8 days, the cells adhered to Nafion appeared more lively and stable than those to PVFHFP. Subcutaneous implantation in mice revealed that Nafion elicited a mild acute inflammatory reaction without chronic inflammation or tissue necrosis, indicating excellent biocompatibility in mice. PVFHFP, however, provoked a moderate and prolonged acute inflammatory response. These differences in the biological characteristics of Nafion and PVFHFP films may be attributable to the differences in the chemical and physical natures of these polymer films. Nafion film provided a sufficiently solid support, expressing a high surface charge density and good water-wettability. In summary, Nafion is suitable for use in biomedical applications that require biocompatibility with a reduced possibility of post-operative infections.

This study examined the feasibility of the combining HDDR-process (hydrogenation, disproportionation, desorption and recombination) with mechanical milling to prepare single domain Nd₂Fe 14 B particles from a Nd-Fe-B alloy ingot. The Nd 15 Fe 77 B? alloy was HDDR-treated and then subjected to a roller-milling. In the HDDRtreated Nd 15 Fe 77 B? alloy, very small Nd₂Fe 14 B grains comparable to their critical single domain size (0.3 ㎛) were observed. These fine individual grains were separated successfully along the grain boundaries by a rollermilling. The separated Nd₂Fe 14 B grains were found to be single domain particles. These results suggest that single domain particles of the Nd₂Fe 14 B phase can be prepared from a Nd-Fe-B ingot alloy by combining a HDDR-process with mechanical milling.

Replacement of dopant P by Si in LiF:Mg,Cu,P has provided an improved LiF:Mg,Cu,Si TLD material. Responses of indigenously developed Korean NaturalLiF:Mg,Cu,Si. 6LiF:Mg,Cu,Si and 7LiF:Mg,Cu,Si TLDs to gamma rays and neutrons were evaluated and compared with the commercially available LiF based TLDs. The intrinsic gamma ray sensitivity of NaturalLiF:Mg,Cu,Si was found to be the highest among the studied TLDs. The gamma ray sensitivities of 6LiF:Mg,Cu,Si and 7LiF:Mg,Cu,Si were about 27 and 32 times higher than that of Harshaw LiF:Mg,Ti. The relative neutron sensitivities (ratio of TL/mGy to neutron and gamma rays) of 6LiF TLDs doped with Mg,Cu,P and Mg,Cu,Si were about the same but lower than that of Harshaw 6LiF:Mg,Ti (TLD-600) due to the difference in their LET dependences. The high intrinsic TL sensitivity of 6LiF:Mg,Cu,Si outweighs the higher relative neutron sensitivity of TLD-600. In the testing following ANSI criteria, the performance quotient of the pairs of 6LiF:Mg,Cu,Si / 7LiF:Mg,Cu,Si held in Har...

During the last 10 years, optically stimulated luminescence (OSL) has emerged as a formidable competitor not only to thermoluminescence dosimetry (TLD) but also to several other dosimetry systems. Though a large number of materials have been synthesized and studied for OSL, Al 2 O 3 :C continues to dominate the dosimetric applications. Re-investigations of OSL in BeOindicate that this material might provide an alternative to Al 2 O 3 :C. Study of OSL of electronic components of mobile phones and ID cards appears to have opened up a feasibility of dosimetry and dose reconstruction using the electronic components of gadgets of everyday use in the events of unforeseen situations of radiological accidents, including the event of a dirty bomb by terrorist groups. Among the newly reported materials, a very recent development of NaMgF 3 :Eu 2+ appears fascinating because of its high OSL sensitivity and tolerable tissue equivalence. In clinical dosimetry, an OSL as a passive dosimeter could do all that TLD can do, much faster with a better or at least the same efficiency; and in addition, it provides a possibility of repeated readout unlike TLD, in which all the dose information is lost in a single readout. Of late, OSL has also emerged as a practical real-time dosimeter for in vivo measurements in radiation therapy (for both external beams and brachytherapy) and in various diagnostic radiological examinations including mammography and CT dosimetry. For in vivo measurements, a probe of Al 2 O 3 :C of size of a fraction of a millimeter provides the information on both the dose rate and the total dose from the readout of radioluminescence and OSL signals respectively, from the same probe. The availability of OSL dosimeters in various sizes and shapes and their performance characteristics as compared to established dosimeters such as plastic scintillation dosimeters, diode detectors, MOSFET detectors, radiochromic films, etc., shows that OSL may soon become the first choice for point dose measurements in clinical applications. A brief review of the recent developments is presented.

We have studied the energy resolution, α / β ratio, temperature dependence of the scintillation properties, and the radioactive contamination of CaMoO4 crystal scintillators. We have also examined the use of pulse-shape discrimination to distinguish γ rays and α particles. A high sensitivity experiment to search for the 0 ν 2 β decay of Mo 100 using CaMoO4 scintillators is discussed.

The die-upset Nd15Fe77B8 material consisting of near single domain Nd2Fe14B grains was prepared using the HDDR-treated material. Texture (c-axis alignment) of the Nd2Fe14B grains in the die-upset HDDR material was investigated, and compared with that in the die-upset melt-spun Nd-Fe-B material. The die-upset HDDR material showed a texture, in which the easy magnetisation c-axis of the Nd2Fe14B grains was aligned parallel to the compression direction. The texture obtained from the die-upset HDDR material was much poorer with respect to that from the die-upset melt-spun material (Nd13.5Fe80Ga0.5B6). The poor texture in the HDDR material was due to the greater grain size of the material. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Results of searches for the β + / EC decays of 64 Zn and 112 Sn, and the ββ decay of 124 Sn to excited states in 124 Te are presented. This work was done at the ChyungPyung Underground Laboratory. An ultra-low background HPGe detector with/without CsI(T l ) crystal was used for gamma tagging. No evidence of any of these decay modes has been found. Lower limits on the half-lives on the 124 Sn decay to different excited channels of ββ decay are set in the range of 10 18 – 10 19 years by 90% C.L. Lower limits of the half-lives of β + / EC decay of 64 Zn, 112 Sn are obtained to be 9.1 × 10 17 years and 1.3 × 10 20 years by 90% C.L., respectively.

BACKGROUND AND PURPOSE: Rhabdoid meningioma (RM) is a recently described variant of malignant meningioma, with radiologic features currently not well characterized in the medical literature. The purpose of this study was to describe and characterize clinical features and imaging findings associated with RM. MATERIALS AND METHODS: CT (n = 8) and MR (n = 15) images of 15 patients (4 men and 11 women; mean age, 52 years; range, 22–75 years) with 16 pathologically proved RMs along with associated clinical records were retrospectively reviewed. All of the patients underwent surgical resection and had additional radiation therapy except for 1 patient. After surgery, the patients had follow-up brain MR imaging to evaluate for tumor recurrence. RESULTS: Nine lesions (56%) were located in the cerebral convexity, and 4 lesions (25%) were located in the parasagittal areas. The tumors were isointense (n = 15) to gray matter on T1-weighted images, whereas they were hyperintense (n = 14) on T2-weighted images. On gadolinium-enhanced T1-weighted images, homogeneous enhancement was seen in 10 lesions, and heterogeneous enhancement was seen in 6 lesions that had cysts. Cystic components were noted in 6 lesions (38%). Severe peritumoral edema was seen in 12 lesions (75%). Nine lesions (56%) had hyperostosis, and 5 of them also had bone destruction. Among the 8 cases with initial CT scans, only 1 had amorphous calcifications (13%). There was only 1 recurrence of RM found during the follow-up period after surgical resection. CONCLUSION: RMs tend to have prominent peritumoral edema, cystic components, and bone involvement.

A great deal of effort have been invested in improving the structural performance and feasibilities of mechanical systems, which are composed of many components. In order to analyse the complex systems, the substructuring techniques based on the behaviour of each component can widely be used in the assembly model that each component is initially incompatible and needs the feasible responses of components. In this paper, this technique is applied to the vehicle body design, and their feasibilities are verified.

Four head of Korean indigenous cattle were presented to the Chonbuk Animal Medical Centre, Chonbuk National University, with the complaint of the presence of extra limb(s) since birth. The accessory limb(s) were underdeveloped in all the cases and attached to the lateral side of the withers craniodorsal to the right scapula in Case 1 and 2; in Case 3, right dorsally to the 4 th cervical vertebra and in Case 4 it was ventrolateral to the thorax caudally to the right forelimb. In all the cases, the congenital anomaly was diagnosed as the presence of supernumerary ectopic limb(s) (SEL), which were removed by surgical excisions under general anaesthesia. In all the cases, the surgical corrections resulted in normal locomotion and better quality of life. No postoperative complications were observed during a 1-year follow up period. The SEL can be successfully removed by surgical excisions, which can result in normal locomotion and better aesthesis of the animal.

The neuronal basis of hyperkinetic movement disorders has long been unclear. We now test the hypothesis that changes in the firing pattern of neurons in the globus pallidus internus (GPi) are related to dyskinesias induced by low doses of apomorphine in patients with advanced Parkinson's disease (PD). During pallidotomy for advanced PD, the activity of single neurons was studied both before and after administration of apomorphine at doses just adequate to induce dyskinesias (21 neurons, 17 patients). After the apomorphine injection, these spike trains demonstrated an initial fall in firing from baseline. In nine neurons, the onset of on was simultaneous with that of dyskinesias. In these spike trains, the initial fall in firing rate preceded and was larger than the fall at the onset of on with dyskinesias. Among the three neurons in which the onset of on occurred before that of dyskinesias, the firing rate did not change at the time of onset of dyskinesias. After injection of apomorphine, dyskinesias during on with dyskinesias often fluctuated between transient periods with dyskinesias and those without. Average firing rates were not different between these two types of transient periods. Transient periods with dyskinesias were characterized by interspike interval (ISI) independence, stationary spike trains, and higher variability of ISIs. A small but significant group of neurons demonstrated recurring ISI patterns during transient periods of on with dyskinesias. These results suggest that mild dyskinesias resulting from low doses of apomorphine are related to both low GPi neuronal firing rates and altered firing patterns.

Near-field scanning optical microscopy (NSOM) studies of self-assembled InAs quantum dot broad area laser diodes (QD-BALDs) with different active layer were performed. The high resolution (

We report on the unusual behaviors of the optical properties for self-assembled InAs/GaAs quantum dots (QDs) by using photoluminescence (PL) spectroscopy. Distinctive double-emission QD peaks are observed in the PL spectra of the samples grown on high growth-temperature condition. From the excitation power-dependent and temperature-dependent PL measurements, these double-emission peaks are associated with the ground-state transitions from InAs QDs with two different size branches. In addition, the variation in the bimodal size distribution of the QD ensembles with different InAs coverage is demonstrated.

Three Cocker Spaniel dogs, 2-3 months old, weighing 3-4 kg, were presented to the Chonbuk Animal Medical Centre, Chonbuk National University, with intersex anomalies. Physical, radiological, gross, histological, hormonal and cytogenetic studies were performed. Physical examination of the external genitalia revealed that the dogs possessed the vulva with an enlarged clitoris protruding from the vulvar juncture and the scrotum with an undescended testis in Case 1 and 2, and both testes remained undescended in Case 3. Hyperoestrogenaemia and low testosterone serum concentrations were found. Laparotomy revealed persistent Mullerian ducts (PMD) in Case 1 and 2, and abdominally located testicle(s) in all the cases. Histological examinations of the gonads revealed inactive seminiferous tubules. Cytogenetic analysis showed 78XY male karyotype in Case 1 and 2, whereas Case 3 showed 79XX female karyotype. The congenital defects were diagnosed as male pseudohermaphroditism (MPH) and PMD in Case 1 and 2, and XX sex reversal MPH in Case 3.

Tin-loaded liquid scintillator offers some advantages as a detector for double beta decay experiment. A research program was carried out with the objective of developing such scintillators. Several organometals were loaded into pseudocumene-based liquid scintillator (LS) and light output variation was studied. Up to 50% of tetramethyltin (32.6% w of tin) was successfully loaded into LS and light output was as high as 57% of unloaded LS. We have studied the characteristics and stability of the one liter tin-loaded LS contained in a Teflon vessel. Several γ -ray radioactive sources were used for energy calibration and calibration data were compared with Monte Carlo simulation. Data-taking at the 700 m underground laboratory in Yangyang is ongoing for the search of 0 ν β β decay of 124 Sn.

SummaryThis study investigated the frequency and distribution of patellar luxation in the dogs presented to the Chonbuk National University Animal Medical Centre during January 2000 to September 2005. Patellar luxations were classified as medial or lateral, and unilateral or bilateral, were graded I to IV, and were subdivided according to age, sex and size of the dogs. The incidence of medial patellar luxation (MPL) was greater than the incidence of lateral patellar luxation (LPL) in both small and large dogs. Small-breed dogs were admitted almost exclusively with MPL. LPL was found uncommon; however it was observed more often in larger-breed dogs. Surgical correction was performed primarily in the dogs (165 stifles in 111 dogs) with grade II, III and IV patellar luxations following different surgical techniques. The combination of the surgical techniques was found to be more effective for the management of the disease. The prognosis was found to be favourable, because when the grade was low, the dog was younger, without cruciate ligament rupture, and as the surgical correction was performed with combination of more techniques.

LiF-based thermoluminescence (TL) materials have been widely used for radiation dosimetry due to their attractive features. LiF:Mg,Cu,P is one of the most sensitive tissue-equivalent TL materials, approximately 40 times more sensitive than LiF:Mg,Ti (TLD-100), but it has two main drawbacks: a thermal loss of the TL sensitivity when annealed at temperatures>240 degrees C, and a relatively high-residual signal. Recently, LiF:Mg,Cu,Na,Si TL material was developed to overcome these drawbacks at the Korea Atomic Energy Research Institute, but it provided only marginal improvements in reducing the residual signal. The newly developed LiF:Mg,Cu,Si TL material has a significantly lower residual signal and a better stability to thermal treatments. In this article, the preparation method and some dosimetric properties (sensitivity and residual signal) of the new LiF:Mg,Cu,Si TL material are presented. At the end of the preparation procedures, a dual-step annealing method is introduced and this has proved as a very efficient method to reduce the high-temperature peak and is the cause of residual signal. Therefore, the high-temperature peak in the glow curve was significantly reduced. The sensitivity is approximately 20 times higher than that of TLD-100 and the residual signal was estimated to be approximately 0.04%.

Current–voltage and low frequency excess electrical noise characteristics of two different—Schottky diode and n-i-n diode—GaAs structures embedded with self-assembled In(Ga)As quantum dots are reported. We find the growth of quantum dots induces defects not only near the quantum dot but also extended to quite a distance toward the growth direction. In Schottky diode structure, comparing with the reference sample without the quantum dot layer, the current dependence of the low frequency noise spectral density indicated that the noise is from the generated interface states with the density increasing towards the band tail. Also the crystal quality of the Schottky diode including the quantum dot layer, deduced from the Hooge parameter, was slightly worse than that of the reference sample. For n-i-n diode structure, the current–voltage relation was linear, and a quadratic current dependence of the noise spectral density was observed. The Hooge parameter for the n-i-n structure was determined to be on the order of unity indicating the general degradation of the structure.

We report some comparative results on the normal-incidence device characteristics accomplished with a couple of self-assembled InAs/GaAs quantum-dot infrared photodetectors (QDIPs) doped in InAs QDs and GaAs barriers. The peak values of responsivity and detectivity for the barrier-doped device are 650 mA/W and 3.2 × 108 cm Hz1/2/W (18 K) at λp ≅ 5 μm, respectively, which are approximately two and ten times higher than those for the QD-doped one. In addition, while there is no spectral response over 6 μm in the QD-doped structure, a strong photoresponse is extended up to around 10 μm in the barrier-doped one. Although the direct doping in InAs QDs is effective for blocking the dark current, the doping in GaAs barriers has better device performance of QDIP.

We have extensively studied the mechanism of the 137 Cs and 134 Cs contamination in CsI compounds. The nuclei 137 Cs and 134 Cs in various samples have been studied using a HPGe detector at deep underground. The main source of the 137 Cs contamination in CsI powder was water dissolved 137 Cs used in the chemical process of cesium extraction at company side. We also found that 134 Cs was produced mainly from 133 Cs by neutron capture. We have successfully produced CsI powder containing no more than 2 mBq/kg of 137 Cs by using only ultra-pure water for whole extraction

Scintillation properties of calcium molybdate are investigated. The emission spectrum is broad with a maximum at 520 nm. At room temperature the light yield is 4% of CsI(Tl) (400 photoelectrons/MeV) and the decay time is 17 /spl mu/s. During cooling the light yield and decay time increase. Prospects of optimization of this scintillator are also discussed. The feasibility of the material for the search of neutrinoless double beta decay of /sup 100/Mo is analyzed. A half life limit of T/sub 1/2/=1/spl middot/10/sup 25/ years (68% CL) seems feasible with CaMoO/sub 4/ scintillator, running with 10 kg of /sup 100/Mo for 5 years. The background due to two neutrino double beta decay of /sup 48/Ca is also considered. Requirements for new scintillators for double beta decay search are formulated.

A single slab in which one Ni(001) atom layer embedded between two of four Rh layers is considered to examine the oscillation of magnetic moment in each layer. The all electron total-energy full-potential linearized augmented plane wave(FLAPW) method was used to calculate the spin densities, magnetic moments, density of states(DOS), and the number of electrons within each muffin-tin(MT) sphere. The magnetic moment of the center layer Ni(C) in the system of 4Rh/Ni/4Rh is calculated to be 0.34, which is 40% have magnetic moment at the interface layers by strong band hybridization with Ni(C) when Ni(001) monolayers is inserted, and the magnetic moment shows a damped oscillation as we go from center Ni(C) layer to the surface Rh(S). From the calculated density of states, it is found that the Fermi level shifts inside the energy band of the Ni(C) in affection of Rh(001).

We examined the prognostic significance of tumor budding in patients with esophageal squamous cell carcinoma, particularly in comparison to other routine pathological findings. Fifty-six cases who underwent an esophagectomy were reviewed. We defined tumor budding as an isolated single cancer cell or a cluster composed of fewer than five cancer cells and divided these into two grades; low-grade (5 budding foci) and high-grade (or = 5 budding foci) within a microscopic field of x 200. There were 22 (39.3%) and 34 (60.7%) cases with low- and high-grade budding, respectively. There were significant differences in the patients with low- and high-grade budding in relation to tumor size, pT stage, lymphovascular invasion, perineural invasion, circumferential resection margin involvement, and AJCC stage (P0.05). The 3-year survival rates of the patients with low- and high-grade budding were 72.3% and 30.7%, respectively (P = 0.04). We propose that tumor budding may be a pathological marker suggesting high malignancy potential and decreased postoperative survival in patients with esophageal squamous cell carcinoma.

The magnetic properties of V and Fe at the interface in V/Fe(110) are investigated theoretically by using the all-electron full-potential linearized augmented plane wave (FLAPW) method within the generalized gradient approximation (GGA) for exchange and correlation. In order to take into account both interface and surface magnetic properties, we considered 2 V monolayers on Fe(110) substrate. The calculated magnetic moments for V and Fe layers exhibit the induced magnetic moments in V couple antiferromagnetically to the Fe one, which is in agreement with other theoretical and experimental results for Fe/V/Fe(110) trilayers. The interface V layer has larger magnetic moment than the surface one, which indicates that the induced V magnetic moment is mainly located at the interface and the surface has nearly no effect to the V/Fe(110). The calculated magnetic moment for interface Fe exhibits slightly reduced value compared with the calculated bulk moment, which is consistent with previous results for Fe/V(110) and implies that there is strong hybridization between the V and Fe layers at the interface.

A total of 80 pigs were used to investigate the effect of dietary glycine betaine( N,N,N -trimethylglycine) onpork quality during cold storage. About 70 kg pigs were randomly alloted into one of four experimental dietgroups(0%, 0.2%, 0.4% and 0.6% glycine betaine). Pigs were slaughtered at approximately 110 kg liveweight, and pH, color(CIE L* a* b*), shear force, sarcomere length, lipid oxidation and composition of fat-ty acid were measured in pork loin for 13 days of cold storage. The concentration of glycine betaine inpork loin was significantly increased(P < 0.05) with incr easing of glycine betaine level in diet. Pork loinsfrom dietary betaine groups showed significantly higher muscle pH and lower CIE b* values compared tocontrol group after 13 days of storage. There were significant differences in shear force values among porkloins from diet groups at 24 hrs postmortem. However, pork loins from control diet showed longer sarco-mere length than those of dietary betaine groups. Dietar y glycine betaine increased the ratio of saturated fattyacids and decreased unsaturated fatty acids in pork loins. Especially the ratios of linoleic and myristic acid were de-creased with increasing dietary betaine level. However, d ietary glycine betaine did not affect lipid oxidation(TBARS) and sensory evaluation during cold storage.

A coupled-channel method was used for the estimation of nucleon optical potential parameters for the actinide region based on the axial rigid-rotor model built on a saturated coupling scheme. A new global form of optical potential was proposed to incorporate energy dependences guided by physical principles. Best-fit potential parameters were searched for to reproduce experimental nucleon scattering angular distributions, low-energy observables (strength functions and scattering radii) and neutron total cross sections of 238U and 232Th. It was found that the present form of the optical potential could reproduce both the neutron- and proton-data for a wide energy range, namely from 1 keV to 200 MeV. Available experimental data for other actinides were also described to a good accuracy with the same set of parameters only by adjusting the deformation parameters for each nucleus.