Barium molybdate up-conversion nanoscale particles with IR-LED chip, temperature sensing, and anti-counterfeiting applications.

Barium molybdate nanoparticles exhibiting up-conversion luminescence were synthesized via the solvothermal method. Analysis revealed a prominent signal corresponding to the (112) plane in the XRD pattern, indicating the tetragonal structure of the synthesized nanoparticles. Raman spectroscopy detected the symmetric stretching frequencies of MoO4. When excited at 980 nm, the nanoparticles emitted a green spectrum with peaks at 532 and 553 nm. The luminescence intensity varied with the excitation light source, supporting the mechanism involving energy transfer from Yb-doped Er ions via the two-photon effect of the up-conversion phosphor. Moreover, the synthesized nanoparticles exhibited diminished luminous intensity with increasing temperature, suggesting potential for flexible composite sensor fabrication. Integration with a 980 nm LED chip yielded a green emission color. Furthermore, when applied to banknotes, plastic cards, fabrics, and artwork, the opaque solution mixed with polymers remained invisible to the naked eye; however, under 980 nm laser irradiation, the distinct green color became apparent, offering a viable approach for anti-counterfeiting measures.

Synthesis of Rare-Earth-Doped Strontium Tungstate Phosphor at Room Temperature and Applied Flexible Composite.

In this study, we successfully synthesized rare-earth-doped crystalline SrWO4 at room temperature by co-precipitation. The results from the X-ray diffraction analysis showed a main diffraction peak related to the (112) plane. Phosphors doped with either Dy3+ or Sm3+ ions showed strong light absorption in the UV region and blue-yellow and red light emission. To synthesize a white light phosphor, Dy3+ and Sm3+ ions were co-doped to produce a SrWO4:[Sm3+]/[Dy3+] phosphor. When the Sm3+ ion concentration was increased and the Dy3+ concentration was maintained, the red light intensity increased while the blue-yellow light intensity decreased. The composites were combined with polydimethylsiloxane (PDMS), and a flexible composite material was fabricated. The composite exhibited various luminescence properties under UV and visible light, which suggested its potential for use as an LED color filter.

Rare-Earth-Doped Barium Molybdate Up-Conversion Phosphor with Potential Application in Optical Temperature Sensing.

A BaMoO4:[Er3+]/[Yb3+] up-conversion (UC) phosphor was synthesized by co-precipitation and calcination of the precursor at 800 °C. The main peak (112) for the synthesized phosphor was strongly detected in the XRD pattern and had a tetragonal structure. The doping of rare-earth ions affected the crystal lattice by shifting the main peak, decreasing the lattice constant, and shifting the position of the Raman signal. The synthesized upconverted phosphor exhibited strong green signals at 530 and 553 nm and weak red signals at 657 nm when excited at 980 nm. The green light emission intensity of the UC phosphor increased as the pump power of the laser increased due to the two-photon effect. The synthesized upconverted phosphor was prepared as a pellet and flexible composite. Thermal quenching led to a decrease in luminescence intensity as the temperature increased, which means that the phosphor can be applied to optical temperature sensing.

Up-conversion luminescence properties with temperature change of strontium tungstate phosphors.

Thermally stable SrWO4:[Er3+]/[Yb3+] upconversion phosphors were synthesized. X-ray diffraction analysis indicated a crystalline inorganic phosphor material with a tetragonal structure having a clear peak in the (112) phase, which is the main peak. The upconversion phosphor was synthesized using a precursor prepared by co-precipitation and sintered at 800 °C. When the phosphor was excited by a 980 nm laser with a pumping power of 200 mW, a strong green light was emitted. As the concentration of Er3+ ions increased, it was observed that the emission intensity decreased due to concentration quenching. The changes in the intensity of luminescence according to the pumping power are due to a two-photon process. As the temperature increased, the green emission intensity of the up-conversion phosphor increased. This was thought to be a phenomenon caused by efficient energy transfer between Yb3+ and Er3+ ions by the SrWO4 host with negative thermal expansion. A composite was prepared by mixing phosphor powder and PDMS, that could be used for temperature sensing.

Barium molybdate white emitting phosphor synthesized at room temperature by co-precipitation.

Crystalline BaMoO4:Dy3+ and BaMoO4:Sm3+ phosphors were synthesized by co-precipitation at room temperature. The main peak (112) phase and tetragonal structure were confirmed using X-ray diffraction analysis. The lattice constant and Raman signal on d (112) were changed by the rare earth doping. A strong absorption wavelength appeared in the UV region, and BaMoO4:Dy3+ excited with UV wavelength showed a yellow spectrum. BaMoO4:Sm3+ showed a reddish orange spectrum. BaMoO4:[Sm3+]/[Dy3+] was synthesized for use as a white light phosphor, and the change in the emission characteristics of yellow, white, and reddish orange could be observed depending on the doping concentration of Sm3+ ions. The synthesized phosphor powder and PDMS polymer were mixed to form a flexible composite, and when applied on a UV-LED chip, the same color as the powder was realized, suggesting its use as an LED color filter.

Fabricated Flexible Composite for a UV-LED Color Filter and Anti-Counterfeiting Application of Calcium Molybdate Phosphor Synthesized at Room Temperature.

Crystalline CaMoO4 and rare-earth-doped CaMoO4:RE3+ (RE = Tb, Eu) phosphors were synthesized at room temperature using a co-precipitation method. The crystal structure of the synthesized powder was a tetragonal structure with a main diffraction peak (112) phase. When CaMoO4 was excited at 295 nm, it showed a central peak of 498 nm and light emission in a wide range of 420 to 700 nm. Rare-earth-ion-doped CaMoO4:Tb3+ was excited at 288 nm and a green light emission was observed at 544 nm, and CaMoO4:Eu3+ was excited at 292 nm and a red light emission was observed at 613 nm. To take advantage of the light-emitting characteristics, a flexible composite was manufactured and a color filter that could be used for UV-LEDs was manufactured. In addition, it was suggested that an ink that could be checked only by UV light could be produced and applied to banknotes so as to prevent counterfeiting.

Development of clinical application program for radiotherapy induced cancer risk calculation using Monte Carlo engine in volumetric-modulated arc therapy.

BACKGROUND: The purpose of this study is to develop a clinical application program that automatically calculates the effect for secondary cancer risk (SCR) of individual patient. The program was designed based on accurate dose calculations using patient computed tomography (CT) data and Monte Carlo engine. Automated patient-specific evaluation program was configured to calculate SCR. METHODS: The application program is designed to re-calculate the beam sequence of treatment plan using the Monte Carlo engine and patient CT data, so it is possible to accurately calculate and evaluate scatter and leakage radiation, difficult to calculate in TPS. The Monte Carlo dose calculation system was performed through stoichiometric calibration using patient CT data. The automatic SCR evaluation program in application program created with a MATLAB was set to analyze the results to calculate SCR. The SCR for organ of patient was calculated based on Biological Effects of Ionizing Radiation (BEIR) VII models. The program is designed to sequentially calculate organ equivalent dose (OED), excess absolute risk (EAR), excess relative risk (ERR), and the lifetime attributable risk (LAR) in consideration of 3D dose distribution analysis. In order to confirm the usefulness of the developed clinical application program, the result values from clinical application program were compared with the manual calculation method used in the previous study. RESULTS: The OED values calculated in program were calculated to be at most approximately 13.3% higher than results in TPS. The SCR result calculated by the developed clinical application program showed a maximum difference of 1.24% compared to the result of the conventional manual calculation method. And it was confirmed that EAR, ERR and LAR values can be easily calculated by changing the biological parameters. CONCLUSIONS: We have developed a patient-specific SCR evaluation program that can be used conveniently in the clinic. The program consists of a Monte Carlo dose calculation system for accurate calculation of scatter and leakage radiation and a patient-specific automatic SCR evaluation program using 3D dose distribution. The clinical application program that improved the disadvantages of the existing process can be used as an index for evaluating a patient treatment plan.

Enhanced Crystallinity and Luminescence Characteristics of Hexagonal Boron Nitride Doped with Cerium Ions According to Tempering Temperatures.

Hexagonal boron nitride was synthesized by pyrolysis using boric acid and melamine. At this time, to impart luminescence, rare earth cerium ions were added to synthesize hexagonal boron nitride nanophosphor particles exhibiting deep blue emission. To investigate the changes in crystallinity and luminescence according to the re-heating temperature, samples which had been subjected to pyrolysis at 900 °C were subjected to re-heating from 1100 °C to 1400 °C. Crystallinity and luminescence were enhanced according to changes in the reheating temperature. The synthesized cerium ion-doped hexagonal boron nitride nanoparticle phosphor was applied to the anti-counterfeiting field to prepare an ink that can only be identified under UV light.

Solitary Testicular Myofibroma in a Rabbit.

Myofibromas are mesenchymal tumours of myofibroblastic origin that occur in solitary or multicentric forms. Solitary benign myofibromas mainly occur on the head and neck, especially in the subcutaneous region. They rarely occur in visceral organs in humans, but visceral myofibroma has not been reported in animals. We now report a case of testicular myofibroma in a 6-year-old rabbit in which orchiectomy revealed an enlarged testis with a multinodular surface. The cut surface of the testis showed a thick, homogeneous white-yellow mass surrounding the testicular parenchyma. Histopathologically, the mass was composed of collagen and eosinophilic fascicles of spindle cells that were immunopositive for α-smooth muscle actin but not desmin, S-100 or von Willebrand factor. These features distinguished the myofibroma from other spindle cell tumours. To the best of our knowledge, this is the first report of solitary testicular myofibroma in any animal species.

Structure and Photoluminescence Properties of Rare-Earth (Dy3+, Tb3+, Sm3+)-Doped BaWO4 Phosphors Synthesized via Co-Precipitation for Anti-Counterfeiting.

Barium tungstate (BaWO4) powders with various sintering temperatures, and BaWO4:Dy3+ phosphor samples with concentrations of different rare-earth (RE) activator ions (Dy3+, Sm3+, Tb3+) were prepared through co-precipitation. The structural, morphological, and photoluminescent characteristics of barium tungstate phosphors depend on the concentration of RE ions. The crystallographic characteristics of the synthesized BaWO4 were analyzed using X-ray diffraction (XRD) patterns. The size and shape of the crystalline particles were estimated based on images measured with a field emission scanning electron microscope (FE-SEM). As the sintering temperature of the BaWO4 particles increased from 400 °C to 1000 °C, the size of the particles gradually increased and showed a tendency to clump together. In the sample doped with 7 mol % Dy3+ ions, the intensity of all emission bands reached their maximum. The emission spectra of the RE3+-doped BaWO4 powders by excitation at 325 nm were composed of yellow (Dy3+), red (Sm3+), and green (Tb3+) band at 572, 640, and 544 nm. This indicates that most of the RE3+ ions absorbed the position without reversal symmetry in the BaWO4 lattice. These results propose that strong emission intensity and tunable color for the phosphors can be accomplished by rare-earth doped host with an suitable quantity. In addition, the phosphor thin films, having high transparency from aqueous colloidal solutions, were deposited on banknotes, and it is considered whether it is suitable for anti-counterfeiting applications.

Fabry disease: characterisation of the plasma proteome pre- and post-enzyme replacement therapy.

BACKGROUND: Fabry disease is characterised by the progressive accumulation of globotriaosylceramide (Gb3) and related glycosphingolipids in vascular endothelial cells. Enzyme replacement therapy (ERT) clears this accumulation. We analysed plasma proteome profiles before and after ERT to characterise its molecular pathology. METHODS: Two-dimensional electrophoresis and matrix-assisted laser desorption/ionisation-time of flight tandem mass spectrometry (MALDI-TOF MS) and tandem mass spectrometry (MS/MS) were done using plasma samples before and after ERT in eight patients with classical Fabry disease RESULTS: After short-term ERT (4-12 months), the levels of 15 plasma proteins involved in inflammation, oxidative and ischaemic injury, or complement activation were reduced significantly. Among them, ß-actin (ACTB), inactivated complement C3b (iC3b), and C4B were elevated significantly in pre-ERT Fabry disease plasma compared with control plasma. After longer-term ERT (46-96 months), iC3b levels gradually decreased, whereas the levels of other proteins varied. The gradual reduction of iC3b was comparable to that of Gb3 levels. In addition, iC3b increased significantly in pre-ERT Fabry disease mouse plasma, and C3 deposits were notable in renal tissues of pre-enzyme replacement therapy patients. CONCLUSION: These results indicated that C3-mediated complement activation might be altered in Fabry disease and ERT might promote its stabilisation.

Dosimetric perturbations due to an implanted cardiac pacemaker in MammoSite(®) treatment.

PURPOSE: To investigate dose perturbations for pacemaker-implanted patients in partial breast irradiation using high dose rate (HDR) balloon brachytherapy. METHODS: Monte Carlo (MC) simulations were performed to calculate dose distributions involving a pacemaker in Ir-192 HDR balloon brachytherapy. Dose perturbations by varying balloon-to-pacemaker distances (BPD = 50 or 100 mm) and concentrations of iodine contrast medium (2.5%, 5.0%, 7.5%, and 10.0% by volume) in the balloon were investigated for separate parts of the pacemaker (i.e., battery and substrate). Relative measurements using an ion-chamber were also performed to confirm MC results. RESULTS: The MC and measured results in homogeneous media without a pacemaker agreed with published data within 2% from the balloon surface to 100 mm BPD. Further their dose distributions with a pacemaker were in a comparable agreement. The MC results showed that doses over the battery were increased by a factor of 3, compared to doses without a pacemaker. However, there was no significant dose perturbation in the middle of substrate but up to 70% dose increase in the substrate interface with the titanium capsule. The attenuation by iodine contrast medium lessened doses delivered to the pacemaker by up to 9%. CONCLUSIONS: Due to inhomogeneity of pacemaker and contrast medium as well as low-energy photons in Ir-192 HDR balloon brachytherapy, the actual dose received in a pacemaker is different from the homogeneous medium-based dose and the external beam-based dose. Therefore, the dose perturbations should be considered for pacemaker-implanted patients when evaluating a safe clinical distance between the balloon and pacemaker.

Rotational alignment of femoral component for minimal medial collateral ligament release in total knee arthroplasty.

PURPOSE: We attempted to determine the degree of rotation of the femoral component to achieve an ideal rectangular flexion gap with minimal medial collateral ligament (MCL) release using a modified measured technique. MATERIALS AND METHODS: Group I consisted of 60 osteoarthritis patients (72 cases) who underwent total knee arthroplasty (TKA) with minimal MCL release and Group II consisted of 48 patients without osteoarthritis (61 cases). We performed computed tomography (CT) scanning of the knee with 90 degree flexion in all of the patients and analyzed the angles between the distal femur landmarks and the tibial mechanical axis using a Picture Archiving Communication system. External rotation of the femoral component from the Whiteside line and posterior condylar line was measured in group I who underwent TKA with minimum MCL release. The variance in the mediolateral flexion gap according to the degree of rotation was also measured using an Auto-Computer Aided Design program. RESULTS: The CT scans showed that the Whiteside line, posterior condylar line, and transepicondylar line was more internally rotated on average from the longitudinal axis of tibia by 4.12°, 5.54°, and 4.64°, respectively, in group I compared to group II. In group I, the femoral component was inserted with an average external rotation of 5.6° from the posterior condylar line and with an average external rotation of 2.0° from the Whiteside line with minimal MCL release. From the measurements of the femoral component size and the variance in the degree of rotation using an Auto-CAD program, it was found that the change in the mediolateral flexion gap was greater when the rotation angle was greater and it was greater when the size of femoral component was larger at the same rotation angle. CONCLUSIONS: The average rotation angle of the femoral component to achieve an ideal rectangular flexion gap with minimal MCL release in TKA was an external rotation of 5.6° from the posterior condylar line and an external rotation of 2.0° from the Whiteside line. We concluded that when a femoral component is small in size, greater than average external rotation needs to be applied and when a femoral component is large in size, less than average external rotation needs to be applied.

Characteristics and clinical outcomes of renal cell carcinoma in children: a single center experience.

The present study aimed to assess the clinicopathological characteristics and the prognosis of renal cell carcinoma (RCC) in children. We retrospectively reviewed the medical records of 11 Korean children (7 boys and 4 girls) undergoing radical nephrectomy for RCC between September 1997 and January 2008 at our institution. Mean age at diagnosis was 12.7 years. The presenting clinical signs and symptoms included gross hematuria (55%), abdominal mass (45%) and abdominal pain (45%). Two (18%) of the cases were discovered incidentally. Five (45%) were conventional clear cell, four (36%) were papillary, one was a chromophobe and one was a translocation carcinoma. Seven children were T1N0M0, three were T2N0M0 and one child was T1N1M0. While one patient with T2 disease died of disease 89 months postoperatively, the remaining 10 patients, including a patient with regional nodal disease who received adjuvant immunochemotherapy, survived without evidence of recurrence at a mean follow-up of 6.8 years. Our data suggest that the clinical presentation, pathological characteristics and clinical behavior of pediatric RCC are different from those of adult RCC.

Spectroscopic and photochemical analysis of proteorhodopsin variants from the surface of the Arctic Ocean.

Proteorhodopsin (PR), a retinal-containing seven transmembrane helix protein, functions as a light-driven proton pump. Using PCR, we isolated 18 PR variants originating from the surface of the Arctic Ocean. Their absorption maxima were between 517 and 546 nm at pH 7. One of the isolates turned out to be identical to GPR (green light-absorbing proteorhodopsin) from Monterey Bay. Interestingly, 10 isolates had replaced a tyrosine in the retinal-binding site (Tyr200 in GPR) with Asn. They showed a slower photocycle, more blue-shifted absorption maxima at pH 10, and relatively larger DeltaH and DeltaS of activation of the transition between the O intermediate and the ground state compared to GPR.

Evaluation of the prognosis and causes of failure in 182 cases of autogenous tooth transplantation.

OBJECTIVES: Autotransplantation is a viable option for treating missing teeth when a donor tooth is available. The aim of this study was to evaluate the prognosis in addition to the causes of failure in 182 autotransplanted teeth. STUDY DESIGN: A total of 182 cases of autotransplantation were analyzed. All the transplants were performed according to a computer-aided rapid prototyping technique with an average extraoral time of 7.58 minutes. These cases were followed for 2 to 60 months after surgery. The prognosis was divided into 4 groups, complete healing, incomplete healing, uncertain healing, and failure. The initial stability, root resorption, and ankylosis were also analyzed. RESULTS: Most transplanted teeth showed complete healing between postoperative 2 months and 8 months. The transplanted teeth with a good initial stability showed better initial healing than those with a poor initial stability. The average extraoral time was 7.58 min (range: immediately after extraction up to 25 min). There was no relationship (P > .05) between the extraoral time and either root resorption (4 cases, 2.4%) or ankylosis (18 cases, 10.7%) within this experimental time period. Nine cases (4.5%) failed. CONCLUSION: This study showed a 4.5% failure rate during the short to intermediate observation period. Autotransplantation is a very useful method for replacing missing teeth, provided that the extraoral time and other factors are well controlled.

Kinetic inactivation study of mushroom tyrosinase: intermediate detection by denaturants.

The unfolding and inhibition study of mushroom tyrosinase have been studied in the presence of different denaturants such as sodium dodecyl sulfate (SDS), guanidine hydrochloride (GdnHCl), and urea. The kinetic two-phase rate constants were commonly measured from semilogarithmic plots of the activity versus time, which resolved into two straight lines, indicating that the inactivation process consisted of fast and slow phases as a first-order reaction. This result also implied that transient partially folded intermediate existed during tyrosinase unfolding pathway. Mushroom tyrosinase had different behaviors to denaturants in regard with: noncooperative binding manner by SDS while cooperative interactions by GdnHCl and urea; in equilibrium state, SDS-micelle never completely inactivated enzyme activity while GdnHCl has single step denaturation and urea induced a typical transition-like process. Various kinetic parameters for each denaturant were calculated and the possible unfolding pathway scheme was discussed.

Cellulose production by Gluconacetobacter hansenii in a medium containing ethanol.

The addition of 1% (v/v) ethanol to the basal medium inhibited growth of Gluconacetobacter hansenii but decreased the numbers of non-cellulose producing cells. Cellulose production increased 1.7 times to approx. 2.5 g l(-1) and showed a pattern of mixed growth-associated production. Microbial cells produced rigid pellicle-type bacterial cellulose as the shell of a large lump of bacterial cellulose like a static culture. The inoculum cultivated for 3 d maintained cellulose production by the fifth batch.