Near-Infrared to Visible Up-Conversion Luminescence Characteristics of Er, Yb Co-Doped LaVO4 Phosphors.

Er3+ and Yb3+ co-doped LaVO4 phosphors were synthesized by the facile solid state reaction method. Er3+ ions concentrations were changed from 0.01 to 0.2 mol for the fixed Yb3+ ions concentration at 0.15 mol. The crystalline structures of the phosphors were investigated by X-ray diffraction (XRD). The composition of the phosphors were investigated by X-ray photoelectron spectroscopy (XPS) analysis. The photoluminescence emissions based on the blue emission near 466 nm and green emission near 553 nm were observed and the highest emission intensity occurred for the sample LaVO4:Yb0.15, Er0.20. The green and red up-conversion emissions were observed in Er3+, Yb3+ co-doped LaVO4 phosphors under the excitation of 980 nm laser diode. LaVO3:Yb3+, Er3+ phosphors could be utilized to produce green colored LEDs by excitation for infra-red LED.

Up-Conversion Luminescence Properties of LaGaO3:Yb3+, Er3+ Phosphors.

LaGaO3:Er3+, Yb3+ powder with different Er3+ contents (0.01~0.10 mol) was synthesized by a conventional solid-state reaction. The structure, morphology and photoluminescence properties of the as-prepared phosphors were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and fluorescence spectrophotometer techniques, respectively. The photoluminescence (PL) emissions based on the green emission near 522 and 544 nm were observed and the highest emission intensity occurred for the sample LaGaO3:Yb0.15, Er0.07. The green and red up-conversion emissions were observed in Er3+, Yb3+ co-doped LaGaO3 phosphors under the excitation of 980 nm laser diode.

Tunable heptamethine-azo dye conjugate as an NIR fluorescent probe for the selective detection of mitochondrial glutathione over cysteine and homocysteine.

Although a lot of mitochondria-targeting biothiol probes have been developed and applied to cellular imaging through thiol-induced disulfide cleavage or Michael addition reactions, relatively few probes assess mitochondrial GSH with high selectivity over Cys and Hcy and with NIR fluorescence capable of noninvasive imaging in biological samples. In order to monitor mitochondrial GSH with low background autofluorescence, we designed a heptamethine-azo conjugate as an NIR fluorescent probe by introducing a tunable lipophilic cation unit as the biomarker for mitochondria and a nitroazo group as the GSH-selective reaction site as well as the fluorescence quencher. The probe exhibited a dramatic off-on NIR fluorescence response toward GSH with high selectivity over other amino acids including Cys and Hcy. Further application to cellular imaging indicated that the probe was highly responsive to the changes of mitochondrial GSH in cells.

Disrupted functional brain connectivity during verbal working memory in children and adolescents with schizophrenia.

Children and adolescents who develop schizophrenia tend to have greater symptom severity than adults who develop the illness. Since the brain continues to mature into early adulthood, developmental differences in brain structure and function may provide clues to the underlying neurobiology of schizophrenia. With an emerging body of evidence supporting disrupted connectivity contributing to the underlying pathophysiology of schizophrenia, it was our goal to assess differences in functional connectivity in children and adolescents who develop schizophrenia. Participants included a total of 28 children and adolescents (14 patients with schizophrenia and 14 age- and gender-matched controls). All subjects underwent a functional magnetic resonance imaging scan involving a modified Sternberg Item Recognition Paradigm with 3 working memory (WkM) loads. Patients had poorer performance at all 3 WkM loads without a load by diagnosis interaction. Functional imaging results demonstrated 3 specific brain networks disrupted in children and adolescents with schizophrenia. These networks include 1) the anterior cingulate and the temporal lobes, bilaterally; 2) the cerebellum with subcortical regions; and 3) the occipital lobe and the cerebellum. Patients with early-onset schizophrenia demonstrate abnormal functional connectivity in networks involving limbic, temporal lobe, cerebellum, and early visual processing streams.

Dysregulation of working memory and default-mode networks in schizophrenia using independent component analysis, an fBIRN and MCIC study.

Deficits in working memory (WM) are a consistent neurocognitive marker for schizophrenia. Previous studies have suggested that WM is the product of coordinated activity in distributed functionally connected brain regions. Independent component analysis (ICA) is a data-driven approach that can identify temporally coherent networks that underlie fMRI activity. We applied ICA to an fMRI dataset for 115 patients with chronic schizophrenia and 130 healthy controls by performing the Sternberg Item Recognition Paradigm. Here, we describe the first results using ICA to identify differences in the function of WM networks in schizophrenia compared to controls. ICA revealed six networks that showed significant differences between patients with schizophrenia and healthy controls. Four of these networks were negatively task-correlated and showed deactivation across the posterior cingulate, precuneus, medial prefrontal cortex, anterior cingulate, inferior parietal lobules, and parahippocampus. These networks comprise brain regions known as the default-mode network (DMN), a well-characterized set of regions shown to be active during internal modes of cognition and implicated in schizophrenia. Two networks were positively task-correlated, with one network engaging WM regions such as bilateral DLPFC and inferior parietal lobules while the other network engaged primarily the cerebellum. Our results suggest that DLPFC dysfunction in schizophrenia might be lateralized to the left and intrinsically tied to other regions such as the inferior parietal lobule and cingulate gyrus. Furthermore, we found that DMN dysfunction in schizophrenia exists across multiple subnetworks of the DMN and that these subnetworks are individually relevant to the pathophysiology of schizophrenia. In summary, this large multisite study identified multiple temporally coherent networks, which are aberrant in schizophrenia versus healthy controls and suggests that both task-correlated and task-anticorrelated networks may serve as potential biomarkers.

Fabrication of nanowire channels with unidirectional alignment and controlled length by a simple, gas-blowing-assisted, selective-transfer-printing technique.

A printing-based lithographic technique for the patterning of V(2)O(5) nanowire channels with unidirectional orientation and controlled length is introduced. The simple, directional blowing of a patterned polymer stamp with N(2) gas, inked with randomly distributed V(2)O(5) nanowires, induces alignment of the nanowires perpendicular to the long axis of the line patterns. Subsequent stamping on the amine-terminated surface results in the selective transfer of the aligned nanowires with a controlled length corresponding to the width of the relief region of the polymer stamp. By employing such a gas-blowing-assisted, selective-transfer-printing technique, two kinds of device structures consisting of nanowire channels and two metal electrodes with top contact, whereby the nanowires were aligned either parallel (parallel device) or perpendicular (serial device) to the current flow in the conduction channel, are fabricated. The electrical properties demonstrate a noticeable difference between the two devices, with a large hysteresis in the parallel device but none in the serial device. Systematic analysis of the hysteresis and the electrical stability account for the observed hysteresis in terms of the proton diffusion in the water layer of the V(2)O(5) nanowires, induced by the application of an external bias voltage higher than a certain threshold voltage.

Auditory oddball deficits in schizophrenia: an independent component analysis of the fMRI multisite function BIRN study.

Deficits in the connectivity between brain regions have been suggested to play a major role in the pathophysiology of schizophrenia. A functional magnetic resonance imaging (fMRI) analysis of schizophrenia was implemented using independent component analysis (ICA) to identify multiple temporally cohesive, spatially distributed regions of brain activity that represent functionally connected networks. We hypothesized that functional connectivity differences would be seen in auditory networks comprised of regions such as superior temporal gyrus as well as executive networks that consisted of frontal-parietal areas. Eight networks were found to be implicated in schizophrenia during the auditory oddball paradigm. These included a bilateral temporal network containing the superior and middle temporal gyrus; a default-mode network comprised of the posterior cingulate, precuneus, and middle frontal gyrus; and multiple dorsal lateral prefrontal cortex networks that constituted various levels of between-group differences. Highly task-related sensory networks were also found. These results indicate that patients with schizophrenia show functional connectivity differences in networks related to auditory processing, executive control, and baseline functional activity. Overall, these findings support the idea that the cognitive deficits associated with schizophrenia are widespread and that a functional connectivity approach can help elucidate the neural correlates of this disorder.

Novel candidate targets of Wnt/beta-catenin signaling in hepatoma cells.

The activity of beta-catenin/TCF, the key component of Wnt signaling pathway, is frequently deregulated in HCC, resulting in the activation of genes whose dysregulation has significant consequences on tumor development. Therefore, identifying the target genes of Wnt signaling is important for understanding beta-catenin-mediated carcinogenesis. We analyzed the transcriptome profile of human hepatoma cell lines using cDNA microarrays representing 15,127 unique, liver-enriched gene loci to identify the target genes of beta-catenin-mediated transcription (p<0.005). This analysis yielded 130 potential Wnt-associated classifier genes, and we found 33 of them contain consensus TCF-binding sites in presumptive transcriptional regulatory sequences. These genes were, then, tested for their Wnt-dependence of expression in experimental models of Wnt activation. Genes such as RPL29, NEDD4L, FUT8, LYZ, STMN2, STARD7 and KIAA0998 were proven to be up-regulated upon Wnt/beta-catenin activation. Gene ontology analysis of the 33 candidate genes indicated the presence of functional categories relevant to Wnt pathway such as cell growth, proliferation, adhesion and signal transduction. In conclusion, we identified a number of candidate Wnt/beta-catenin target genes that can be useful for studying the role of altered Wnt signaling in liver cancer development, and showed that some of them might be direct targets of Wnt signaling in hepatoma cells.

Compact RF ion source for industrial electrostatic ion accelerator.

Korea Multi-purpose Accelerator Complex is developing a single-ended electrostatic ion accelerator to irradiate gaseous ions, such as hydrogen and nitrogen, on materials for industrial applications. ELV type high voltage power supply has been selected. Because of the limited space, electrical power, and robust operation, a 200 MHz RF ion source has been developed. In this paper, the accelerator system, test stand of the ion source, and its test results are described.

Production of superoxide anion and hydrogen peroxide by the red tide dinoflagellate Karenia mikimotoi.

We found that the red tide dinoflagellate Karenia mikimotoi (Gymnodinium mikimotoi) generates reactive oxygen species (ROS). In chemiluminescence analysis using an O2- specific probe, a slightly lower but significant level of O2- was detected in a K. mikimotoi cell suspension as compared to one containing Chattonella marina, a well-known ROS-producing red tide phytoplankton. Interestingly, the chemiluminescence response pattern caused by K. mikimotoi was different from that of C. marina, although both responses were almost completely abolished in the presence of superoxide dismutase (SOD). By fluorescence spectrophotometric analysis, H2O2 was also detected in the K. mikimotoi cell suspension, but the level of H2O2 was approximately 10% of that in the C. marina suspension based on the cell number. No significant increase in O2- generation by K. mikimotoi was observed in the presence of lectins such as concanavalin A (Con A) and wheat germ agglutinin (WGA) or fish mucus substances prepared from the skin and gills of yellowtail, whereas C. marina generated an increased level of O2- in response to these stimuli. Furthermore, O2- production in C. marina, but not in K. mikimotoi, was inhibited by treatment with proteinase K.

Clinical significance of free-to-total prostate-specific antigen (PSA) ratio in advanced prostate cancer patients with PSA less than 0.1 ng/ml after hormone treatment.

PURPOSE: We analyzed the pattern of change in the free-to-total prostate-specific antigen (f/t PSA) ratio and the progression to castration-resistant prostate cancer (CRPC) in patients with advanced prostate cancer who received hormone treatment and whose PSA nadir was below 0.1 ng/ml. MATERIALS AND METHODS: We retrospectively analyzed the medical records of 52 patients with advanced prostate cancer. All patients were treated with maximum androgen blockade (gonadotrophin-releasing hormone agonist and anti-androgen agents). The patients were divided into two groups: those with a nadir f/t PSA ratio above 60% and those with a nadir f/t PSA ratio of 60% or below. Age, initial PSA, clinical stage, lymph node metastasis, bone metastasis, and follow-up data, including PSA, free PSA, and f/t PSA ratio, were collected. The Mann-Whitney U-test, Fisher exact test, chi-square test, Kaplan-Meier survival analysis, and log rank test were used. RESULTS: There were 24 patients in the group with a nadir f/t PSA ratio above 60% and 28 patients in the group with a nadir f/t PSA ratio of 60% or below. After hormone therapy, the median f/t PSA ratio in each group increased from 37% and 34% at 3 months to 75% and 60% at 6 months, respectively. At 9 months, however, the f/t PSA ratio increased to 80% in the group with a nadir f/t PSA ratio above 60%, whereas it decreased to 31% in the group with a nadir f/t PSA ratio of 60% or below. From 9 to 15 months, the f/t PSA ratio showed a tendency to decrease (75 to 37% and 27 to 20%, respectively). The progression to CRPC was significantly different between the two groups (10 vs. 24). CONCLUSIONS: Progression to CRPC was significantly higher in the group with a lower f/t PSA ratio. Additionally, the pattern of change in the f/t PSA ratio was significantly different after 9 months. Collectively, the f/t PSA ratio can be used as an additional marker for prognosis of hormone treatment.

Compact microwave ion source for industrial applications.

A 2.45 GHz microwave ion source for ion implanters has many good properties for industrial application, such as easy maintenance and long lifetime, and it should be compact for budget and space. But, it has a dc current supply for the solenoid and a rf generator for plasma generation. Usually, they are located on high voltage platform because they are electrically connected with beam extraction power supply. Using permanent magnet solenoid and multi-layer dc break, high voltage deck and high voltage isolation transformer can be eliminated, and the dose rate on targets can be controlled by pulse duty control with semiconductor high voltage switch. Because the beam optics does not change, beam transfer components, such as focusing elements and beam shutter, can be eliminated. It has shown the good performances in budget and space for industrial applications of ion beams.

Therapeutic monitoring of vancomycin according to initial dosing regimen in pediatric patients.

PURPOSE: This study aimed to determine the optimal initial vancomycin dose to achieve appropriate trough levels in pediatric patients. METHODS: We analyzed clinical data for 309 children treated with intravenous vancomycin between 2004 and 2009 at 2 different hospitals in South Korea. The patients were 1-16 years old and exhibited normal renal function. Patient data, including reason for treatment and initial dosing regimen, were reviewed. Two subgroups were identified and compared according to initial vancomycin dose: 40 (35-45) mg/kg/day and 60 (55-65) mg/kg/day. Trough levels were obtained at steady state after at least 4 doses of vancomycin. RESULTS: Patients who received vancomycin had post-operation or wound-related infections (37.2%), localized infection (12.9%), catheter-related infections (9.4%), meningitis (8.7%), or endocarditis (6.8%). Pathogens were confirmed in 79 cases: 28 cases of methicillin-resistant Staphylococcus epidermidis (35.4%) and 25 of methicillin-resistant Staphylococcus aureus (31.6%). Out of the 309 patients, 201 (65%) received vancomycin at 40 mg/kg/day and 108 (35%) at 60 mg/kg/day. Average trough concentrations were significantly different between the groups (P<0.001). Trough levels over 10 mg/L were less likely to be achieved in the 40 mg/kg/day group (14%) than in the 60 mg/kg/day group (49%) (P<0.001). There were no differences in renal function deterioration between the groups. CONCLUSION: A common vancomycin dosing regimen, 40 mg/kg/day, was not high enough to achieve trough levels of over 10 mg/L in pediatric patients. Careful drug monitoring must be performed, and increasing initial dose of vancomycin should be considered in pediatric patients.

Identification of imaging biomarkers in schizophrenia: a coefficient-constrained independent component analysis of the mind multi-site schizophrenia study.

A number of recent studies have combined multiple experimental paradigms and modalities to find relevant biological markers for schizophrenia. In this study, we extracted fMRI features maps from the analysis of three experimental paradigms (auditory oddball, Sternberg item recognition, sensorimotor) for a large number (n=154) of patients with schizophrenia and matched healthy controls. We used the general linear model (GLM) and independent component analysis (ICA) to extract feature maps (i.e. ICA component maps and GLM contrast maps), which were then subjected to a coefficient-constrained independent component analysis (CCICA) to identify potential neurobiological markers. A total of 29 different feature maps were extracted for each subject. Our results show a number of optimal feature combinations that reflect a set of brain regions that significantly discriminate between patients and controls in the spatial heterogeneity and amplitude of their feature signals. Spatial heterogeneity was seen in regions such as the superior/middle temporal and frontal gyri, bilateral parietal lobules, and regions of the thalamus. Most strikingly, an ICA feature representing a bilateral frontal pole network was consistently seen in the ten highest feature results when ranked on differences found in the amplitude of their feature signals. The implication of this frontal pole network and the spatial variability which spans regions comprising of bilateral frontal/temporal lobes and parietal lobules suggests that they might play a significant role in the pathophysiology of schizophrenia.

A large cystic phyllodes tumor of the prostate.

We report a 65 year-old man with a large cystic phyllodes tumor of the prostate. The patient complained of abdominal discomfort and had a soft palpable mass. Computer tomography showed a solid and cystic mass in the pelvic fossa; the mass was adjacent only to the prostate. We excised the mass. Microscopic findings of the mass showed hyperplastic epithelium lined cysts with leaf-like intraluminal epithelia lined stromal projections, less than 2 mitotic counts/10 HPF, low-to-moderated cellularity, and mild-to-moderate cytoplasm atypia. The pathological findings were consistent with a phyllodes tumor of the prostate, a low-grade tumor. Twenty-eight months after the operation, the patient was well with no recurrence or metastases.

Facile transfer of thickness controllable poly(methyl methacrylate) patterns on a nanometer scale onto SiO2 substrates via microcontact printing combined with simplified Langmuir-Schaefer technique.

We report on the facile patterning of poly(methyl methacrylate) (PMMA) layers onto SiO2 substrates via microcontact printing combined with the simplified Langmuir-Schaefer (LS) technique. Langmuir film of PMMA was formed just by dropping a dilute PMMA solution onto the air/water surface in a glass Petri dish via self-assembly, and it was used as an ink for the patterned poly(dimethylsilioxane) (PDMS) stamp. The transferred film properties were systematically investigated with variation of postannealing temperature, molecular weight of PMMA, and the inking number. The patterned PMMA film surface was smooth with no vacancy defect in a few micrometers scale AFM images over the whole film area after post-annealing process. The thickness of the PMMA patterns was controlled on the nanometer scale by the number of inkings of the LS layer of PMMA on the PDMS stamp. By using the PMMA patterns as a barrier and a sacrificial layer against the chemical etching and metal deposition, SiO2 and metal patterns were fabricated, respectively. The PMMA layers also worked as a passivation layer against the patterning of V2O5 nanowires and the selective adsorption of single-walled carbon nanotubes (SWCNTs). We also fabricated thin film transistors using patterned SWCNTs with different percolation states and investigated the electrical properties.

STMN2 is a novel target of beta-catenin/TCF-mediated transcription in human hepatoma cells.

The activity of beta-catenin/TCF, the key component of Wnt signaling pathway, is frequently deregulated in human cancers, resulting in the activation of genes whose dysregulation has significant consequences on tumor development. Therefore, identifying the target genes of Wnt signaling is important for understanding beta-catenin-mediated carcinogenesis. Here, we report STMN2, a gene implicated in the regulation of microtubule dynamics, as a novel target of beta-catenin-mediated transcription. STMN2 was up-regulated in hepatoma and cirrhotic liver tissues compared to normal liver and also in cell lines where beta-catenin/TCF is constitutively activated. Transient activation of beta-catenin/TCF either by transfection of a constitutively active form of beta-catenin or by LiCl treatment induced the STMN2 mRNA expression in PLC/PRF/5 cells. Of the four members of STMN gene family, only STMN2 showed a Wnt-dependent expression pattern. Through promoter mapping and chromatin immunoprecipitation assays, we found that STMN2 is a direct target of beta-catenin/TCF-mediated transcription and that the TCF binding site at -1713 of STMN2 promoter is critical for beta-catenin/TCF-dependent expression regulation. siRNA-mediated knock-down of STMN2 expression indicated that STMN2 is required for maintaining the anchorage-independent growth state of beta-catenin/TCF-activated hepatoma cells. Our results suggest that STMN2 might be a novel player of beta-catenin/TCF-mediated carcinogenesis in the liver.

Promoter analysis and regulatory characteristics of vvhBA encoding cytolytic hemolysin of Vibrio vulnificus.

Cytolytic hemolysin, a gene product of vvhA, is a putative virulence factor of the pathogenic bacterium Vibrio vulnificus. We have previously shown that hemolysin production is repressed by adding glucose to culture media and that production can be restored by adding cAMP. In this study, hemolysin activity and the level of vvh transcript were determined to reach a maximum in late exponential phase and were repressed when cells entered stationary phase. Northern blot and primer extension analyses revealed that vvhA is cotranscribed with a second gene, vvhB, located upstream of vvhA. Transcription of the vvhBA operon begins at a single site and is under the direction of a single promoter, P(vvh). A crp null mutation decreased hemolysin production and the level of vvhBA transcript by reducing the activity of P(vvh), indicating that the P(vvh) activity is under the positive control of cAMP receptor protein (CRP). A direct interaction between CRP and the regulatory region of the vvhBA operon was demonstrated by gel-mobility shift assays. The CRP binding site, centered at 59.5 bp upstream of the transcription start site, was mapped by deletion analysis of the vvhBA promoter region and confirmed by DNase I protection assays. These results demonstrate that the vvhBA expression is activated by CRP in a growth-dependent manner and that CRP exerts its effects by directly binding to DNA upstream of P(vvh).