91 research outputs found

    A Wide Tuning-Range CMOS VCO with a Tunable Active Inductor

    Get PDF
    This study describes a wide tuning-range VCO using tunable active inductor (TAI) topology and cross-coupled pair configuration for radio frequency operation. The TAI used two feedback loops to form a cascode circuit to obtain more degrees of freedom for inductance value. The TAI-VCO was fabricated using a 0.18 μm CMOS technology. The coarse frequency tuning is achieved by TAIs while the fine tuning is controlled by varactors. The fabricated circuit provides an output frequency range from 0.6 to 7.2 GHz (169%). The measured phase noise is from −110.38 to −86.01 dBc/Hz at a 1 MHz offset and output power is from −11.11 to −3.89 dBm within the entire frequency range under a 1.8 V power supply

    The Relationship between Brown Adipose Tissue Activity and Neoplastic Status: an 18F-FDG PET/CT Study in the Tropics

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Brown adipose tissue (BAT) has thermogenic potential. For its activation, cold exposure is considered a critical factor though other determinants have also been reported. The purpose of this study was to assess the relationship between neoplastic status and BAT activity by 2-deoxy-2-[18F]fluoro-D-glucose (<sup>18</sup>F-FDG) positron emission tomography/computed tomography (PET/CT) in people living in the tropics, where the influence of outdoor temperature was low.</p> <p>Methods</p> <p><sup>18</sup>F-FDG PET/CT scans were reviewed and the total metabolic activity (TMA) of identified activated BAT quantified. The distribution and TMA of activated BAT were compared between patients with and without a cancer history. The neoplastic status of patients was scored according to their cancer history and <sup>18</sup>F-FDG PET/CT findings. We evaluated the relationships between the TMA of BAT and neoplastic status along with other factors: age, body mass index, fasting blood sugar, gender, and outdoor temperature.</p> <p>Results</p> <p>Thirty of 1740 patients had activated BAT. Those with a cancer history had wider BAT distribution (<it>p </it>= 0.043) and a higher TMA (<it>p </it>= 0.028) than those without. A higher neoplastic status score was associated with a higher average TMA. Multivariate analyses showed that neoplastic status was the only factor significantly associated with the TMA of activated BAT (<it>p </it>= 0.016).</p> <p>Conclusions</p> <p>Neoplastic status is a critical determinant of BAT activity in patients living in the tropics. More active neoplastic status was associated with more vigorous TMA of BAT.</p

    A novel deep intronic variant strongly associates with Alkaptonuria.

    Get PDF
    Alkaptonuria is a rare autosomal recessive inherited disorder of tyrosine metabolism, which causes ochronosis, arthropathy, cardiac valvular calcification, and urolithiasis. The epidemiology of alkaptonuria in East Asia is not clear. In this study, patients diagnosed with alkaptonuria from January 2010 to June 2020 were reviewed. Their clinical and molecular features were further compared with those of patients from other countries. Three patients were found to have alkaptonuria. Mutation analyses of the homogentisate 1,2-dioxygenase gene (HGD) showed four novel variants c.16-2063 A > C, p.(Thr196Ile), p.(Gly344AspfsTer25), and p.(Gly362Arg) in six mutated alleles (83.3%). RNA sequencing revealed that c.16-2063 A > C activates a cryptic exon, causing protein truncation p.(Tyr5_Ile6insValTer17). A literature search identified another 6 patients with alkaptonuria in East Asia; including our cases, 13 of the 18 mutated alleles have not been reported elsewhere in the world. Alkaptonuria is rare in Taiwan and East Asia, with HGD variants being mostly novel and private

    Effects of Metformin on the Cerebral Metabolic Changes in Type 2 Diabetic Patients

    Get PDF
    Metformin, a widely used antidiabetic drug, has numerous effects on human metabolism. Based on emerging cellular, animal, and epidemiological studies, we hypothesized that metformin leads to cerebral metabolic changes in diabetic patients. To explore metabolism-influenced foci of brain, we used 2-deoxy-2-[18F]fluoro-D-glucose (FDG) positron emission tomography for type 2 diabetic patients taking metformin (MET, n=18), withdrawing from metformin (wdMET, n=13), and not taking metformin (noMET, n=9). Compared with the noMET group, statistical parametric mapping showed that the MET group had clusters with significantly higher metabolism in right temporal, right frontal, and left occipital lobe white matter and lower metabolism in the left parahippocampal gyrus, left fusiform gyrus, and ventromedial prefrontal cortex. In volume of interest (VOI-) based group comparisons, the normalized FDG uptake values of both hypermetabolic and hypometabolic clusters were significantly different between groups. The VOI-based correlation analysis across the MET and wdMET groups showed a significant negative correlation between normalized FDG uptake values of hypermetabolic clusters and metformin withdrawal durations and a positive but nonsignificant correlation in the turn of hypometabolic clusters. Conclusively, metformin affects cerebral metabolism in some white matter and semantic memory related sites in patients with type 2 diabetes

    Improved Image Quality for Static BLADE Magnetic Resonance Imaging Using the Total-Variation Regularized Least Absolute Deviation Solver.

    Get PDF
    In order to improve the image quality of BLADE magnetic resonance imaging (MRI) using the index tensor solvers and to evaluate MRI image quality in a clinical setting, we implemented BLADE MRI reconstructions using two tensor solvers (the least-squares solver and the L1 total-variation regularized least absolute deviation (L1TV-LAD) solver) on a graphics processing unit (GPU). The BLADE raw data were prospectively acquired and presented in random order before being assessed by two independent radiologists. Evaluation scores were examined for consistency and then by repeated measures analysis of variance (ANOVA) to identify the superior algorithm. The simulation showed the structural similarity index (SSIM) of various tensor solvers ranged between 0.995 and 0.999. Inter-reader reliability was high (Intraclass correlation coefficient (ICC) = 0.845, 95% confidence interval: 0.817, 0.87). The image score of L1TV-LAD was significantly higher than that of vendor-provided image and the least-squares method. The image score of the least-squares method was significantly lower than that of the vendor-provided image. No significance was identified in L1TV-LAD with a regularization strength of λ= 0.4-1.0. The L1TV-LAD with a regularization strength of λ= 0.4-0.7 was found consistently better than least-squares and vendor-provided reconstruction in BLADE MRI with a SENSitivity Encoding (SENSE) factor of 2. This warrants further development of the integrated computing system with the scanner

    4β-Hydroxywithanolide E from Physalis peruviana (golden berry) inhibits growth of human lung cancer cells through DNA damage, apoptosis and G2/M arrest

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>The crude extract of the fruit bearing plant, <it>Physalis peruviana </it>(golden berry), demonstrated anti-hepatoma and anti-inflammatory activities. However, the cellular mechanism involved in this process is still unknown.</p> <p>Methods</p> <p>Herein, we isolated the main pure compound, 4β-Hydroxywithanolide (4βHWE) derived from golden berries, and investigated its antiproliferative effect on a human lung cancer cell line (H1299) using survival, cell cycle, and apoptosis analyses. An alkaline comet-nuclear extract (NE) assay was used to evaluate the DNA damage due to the drug.</p> <p>Results</p> <p>It was shown that DNA damage was significantly induced by 1, 5, and 10 μg/mL 4βHWE for 2 h in a dose-dependent manner (<it>p </it>< 0.005). A trypan blue exclusion assay showed that the proliferation of cells was inhibited by 4βHWE in both dose- and time-dependent manners (<it>p </it>< 0.05 and 0.001 for 24 and 48 h, respectively). The half maximal inhibitory concentrations (IC<sub>50</sub>) of 4βHWE in H1299 cells for 24 and 48 h were 0.6 and 0.71 μg/mL, respectively, suggesting it could be a potential therapeutic agent against lung cancer. In a flow cytometric analysis, 4βHWE produced cell cycle perturbation in the form of sub-G<sub>1 </sub>accumulation and slight arrest at the G<sub>2</sub>/M phase with 1 μg/mL for 12 and 24 h, respectively. Using flow cytometric and annexin V/propidium iodide immunofluorescence double-staining techniques, these phenomena were proven to be apoptosis and complete G<sub>2</sub>/M arrest for H1299 cells treated with 5 μg/mL for 24 h.</p> <p>Conclusions</p> <p>In this study, we demonstrated that golden berry-derived 4βHWE is a potential DNA-damaging and chemotherapeutic agent against lung cancer.</p

    Household secondhand smoke exposure of elementary schoolchildren in Southern Taiwan and factors associated with their confidence in avoiding exposure: a cross-sectional study

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Exposure to household Secondhand Smoke (SHS) poses a major health threat to children after an indoor smoking ban was imposed in Taiwan. This study aimed to assess the household SHS exposure in elementary school children in southern Taiwan and the factors associated with their avoidance of SHS exposure before and after the implementation of Taiwan's new Tobacco Hazards Prevention Act in 2009.</p> <p>Methods</p> <p>In this cross-sectional school-based study, data on household SHS exposure, avoidance of SHS and related variables was obtained from the 2008 and 2009 Control of School-aged Children Smoking Study Survey. A random sample of 52 elementary schools was included. A total of 4450 3-6 graders (aged 8-13) completed the questionnaire. Regression models analyzed factors of children's self-confidence to avoid household SHS exposure.</p> <p>Results</p> <p>Over 50% of children were found to have lived with a family member who smoked in front of them after the new law enacted, and 35% of them were exposed to household SHS more than 4 days a week. Having a positive attitude toward smoking (β = -0.05 to -0.06) and high household SHS exposure (β = -0.34 to -0.47) were significantly associated with a lower avoidance of SHS exposure. Comparing to girls, boys had lower scores in their knowledge of tobacco hazards; and this factor was significantly related to their SHS avoidance (β = 0.13-0.14).</p> <p>Conclusions</p> <p>The intervention program should enhance school children do actively avoid exposure to SHS in home settings, and more importantly, provide tobacco hazard knowledge to male students to avoid exposure to household SHS for themselves. The results also provide further evidence that Tobacco Hazards Prevention Act should perhaps be extended to the family environment in order to protect children from the hazards of household SHS exposure.</p

    Effects of Taiwanofungus camphoratus on non-specific and specific immune activities in mice

    No full text
    Taiwanofungus camphoratus is a precious medicinal fungus endemic to Taiwan and has been used as traditional medicine for a long time. Many pharmacological studies have revealed that T. camphoratus possessed various biological activities, such as immunomodulatory effects, anticancer activity and liver protective function. The aim of this study is to investigate the non-specific and antigen (ovalbumin [OVA])-specific immunomodulation effects of solid-state cultivated powder of T. camphoratus (Leader Antrodia cinnamomea [LAC]) in BABL/c male mice. In non-specific and antigen-specific immune function studies, 8-week-old mice were orally administered with LAC for 6 and 8 weeks, respectively. The results have shown that the proliferation of splenic immune cells, phagocytic activity of macrophages and cytolytic activity of natural killer cells were enhanced by LAC. Additionally, LAC increased the levels of IL-2, TNF-α, INF-γ, GM-CSF and serum OVA-IgG and OVA-IgM. These findings provided evidences that LAC had the immunomodulation effects on both antigen-specific and non-specific immune responses in mice

    A KaKa -Band GaAs MMIC Traveling-Wave Switch With Absorptive Characteristic

    No full text
    corecore