2,618 research outputs found
Regulation of phospholipase C-beta 3 activity by Na+/H+ exchanger regulatory factor 2
No full textAmong the phospholipase C that catalyzes the hydrolysis of phosphatidylinositol 4,5-bisphosphate, four mammalian phospholipase C-beta (PLC-beta) isotypes (isotypes 1-4) are activated through G protein-coupled receptors (GPCRs). Although the regulation of the PLC-beta s by GPCRs and heterotrimeric G proteins has been extensively studied, little is known about the molecular determinants that regulate their activity. The PLC-beta isozymes carry a putative PSD-95/Dlg/ZO-1 (PDZ) binding motif (X(S/T)X(V/L)COOH) at their carboxyl terminus, which is implicated in specific interactions with anchor proteins. Using the yeast two-hybrid system, me identified Na+/H+ exchanger regulatory factor 2 (NHERF2) as a protein that interacted with a C-terminal heptapeptide of PLC-beta 3. Immunoprecipitation studies revealed that NHERF2 interacts specifically with PLC-beta 3, but not with other PLC-beta isotypes. Furthermore, PLC-beta 3 interacted with NHERF2 rather than with other PDZ-containing proteins. This interaction required the COOH-terminal NTQL sequence of PLC-beta 3 and the second PDZ domain of NHERF2. Interestingly, NHERF2 potentiated the PLC-beta activation by carbachol in COS7 and HeLa cells, while mutant NHERF2, lacking the second PDZ domain, had no such effect. Taken together, the data suggest that NHERF2 may act as a modulator underlying the process of PLC-beta 3-mediated signaling
Highly valuable chemicals production from catalytic upgrading of radiata pine sawdust-derived pyrolytic vapors over mesoporous MFI zeolites
No full textThe catalytic upgrading of pyrolytic vapors derived from radiata pine sawdust was carried out over mesoporous MEI zeolite synthesized using an amphiphilic organosilane. Its catalytic activity was compared with those of conventional HZSM-5 and mesoporous material from HZSM-5 (MMZ(ZSM-5)). The effect of gallium incorporation into mesoporous MEI zeolite on the product distribution and chemical composition of bio-oil was also investigated. The catalysts synthesized were characterized using ICP, XRD, N(2)-sorption, NH(3)-TPD, and H(2)-TPR methods. After catalytic upgrading, products were analyzed by GC-TCD, GC-FID, GC-MS, and Karl Fischer titration. The mesoporous MEI zeolite exhibited the best activity in deoxygenation and aromatization during the upgrading of pyrolytic vapors. In particular, mesoporous MEI zeolite showed high selectivity for highly valuable aromatics, such as benzene, toluene, and xylenes (BTX), even though it decreased the overall organic fraction of the bio-oil. The incorporation of gallium into the mesoporous MEI zeolite increased both the organic fraction of the bio-oil and resistance to coke deposition. Moreover, the selectivity for BTX aromatics was enhanced when the appropriate amount of gallium was introduced. (C) 2010 Elsevier B.V. All rights reserved.R.R. acknowledges support from the Korean Ministry of
Education, Science and Technology through the National Honor
Scientist Program
Prevalence of Endocrine Disorders in Childhood Brain Tumor Survivors in South Korea
No full textBACKGROUND/AIM: This longitudinal study aimed to analyze the prevalence of endocrine disorders in childhood brain tumor survivors in South Korea using claims data.
PATIENTS AND METHODS: We identified in 1,058 patients from a nationwide cohort of patients diagnosed with brain tumors between January 1st 2009 to March 29th 2016. Multivariable logistic regression was used to evaluate associations between clinical factors and endocrine disorders.
RESULTS: After a median follow-up of 60.0 months, 393 (37.1%) patients had at least 1 endocrine disorder. The commonest endocrine disorders were hypopituitarism (17.4%) and hypothyroidism (6.1%). Female gender (odds ratio(OR)=1.45, p=0.005) and age <10 years (OR=1.65, p=0.001) conferred a higher risk. Patients who received radiotherapy were more likely to have endocrine disorders compared to those who did not (OR=1.79, p<0.001).
CONCLUSION: Regular assessment of endocrine function and timely interventions are necessary for childhood brain tumor survivors with a risk of endocrine disorders
Modification of the local phonon modes and electron-phonon coupling strengths in Dy3+-doped sulfide glasses for efficient 1.3 mu m amplification
No full textThe effect of changes in the local phonon modes and electron-phonon coupling strengths on the 1.31 mu m fluorescence efficiency of Dy3+-doped sulfide glass was investigated. An addition of 10 mole% CsBr resulted in a sharp increase in the 1.31 mu m emission intensity at the expense of the 1.75 mu m emission. The lifetime of the 1.31 mu m emission level (F-6(11/2)-H-6(9/2)) increased to 1.58 ms, which was more than 40 times larger than that of the Ge-Ga-S host. Quantum efficiency increased from 17% to approximately 100%. These changes in the optical characteristics resulted from the large changes in the local phonon modes and electron-coupling strengths through the addition of CsBr to Ge25Ga10S65 glass. (C) 2000 Elsevier Science B.V. All rights reserved.X1141sciescopu
Enhancement of the 1.31-mu m emission properties of Dy3+-doped Ge-Ga-S glasses with the addition of alkali halides
No full textAlkali halides such as KBr, KI, CsBr, and CsI were added to Dy3+-doped Ge-Ga-S glasses, and their effects on the 1.31-mum emission property were investigated, The intensities of the 1.31-mum emission (F-6(11/2) . H-6(9/2) --> H-6(15/2)) increased at the expense of the 1.75-mum emission intensity (H-6(11/2) --> H-6(15/2)) With the alkali halide addition. The lifetimes of the 1.31-mum emission level also increased as much as 35 times from 38 mus for Ge-Ga-S glass to 1320 mus for the glass containing 10 mol% CsBr. These enhancements occurred only when the ratio of MX (M = K, Cs; X = Pr, I)/Ga was equal to or larger than unity, Raman spectra of Ge-Ga-S-CsBr glasses indicated the formation of [GaS3/2Br](-) complexes, which provide the preferred sites for Dy3+. Due to this new local environment of Dy3+, the multiphonon relaxation rates from the Dy3+:F-6(11/2) . H-6(9/2) level decreased by approximately four orders of magnitude. The enhancement in the 1.31-mum emission properties with alkali halide addition supports the potentials of these glasses as hosts for the Dy3+-doped fiber-optic amplifiers.X1143sciescopu
Compositional dependence of the 1.3 mu m emission and energy transfer mechanism in Ge-Ga-S glasses doped with Pr3+
No full textEffects of concentration on the amplification efficiency at 1.3 mu m were investigated in Ge-Ga-S glass doped with 100-5000 ppm (in wt.) Pr3+. Quantum efficiencies and figure-of-merits (sigma(g)tau(m)) increased from 49%, 26.3 +/- 0.5 x 10(-25) cm(2) s to 66%, 31.1 +/- 0.5 x 10(-25) cm(2) s, respectively, with sulfur concentration decreasing from 69 to 63 at.%. Optimum compositions of the host glasses are Ge32Ga5S63 and Ge28Ga20S62 (at.%). Concentration of Pr3+ must be <500 ppm in weight to minimize detrimental cross relaxation, which is the major energy transfer process in glasses. A linear dependence of the reduced diffusion coefficients indicated an inhomogeneous distribution of Pr3+ in glasses. (C) 1999 Elsevier Science B.V. All rights reserved.X1115sciescopu
The use of machine learning to identify the correctness of HS Code for the customs import declarations
No full textAs an increasing volume of international trade activities around the world, the amount of cross-boarder import declarations grows rapidly, resulting in an unprecedented scale of potentially fraudulent transactions, in particular false commodity code (e.g., HS Code). The incorrect HS Code will cause duty risk and adversely impact the revenue collection. Physical investigation by the customs administrations is impractical due to the substantial quantity of declarations. This paper provides an automatic approach by harnessing the power of machine learning techniques to relief the burden of customs targeting officers. We introduced a novel model based on the off-the-shelf embedding encoder to identify the correctness of HS Code without any human effort. Determining whether the HS Code is correctly matched with commodity description is a classification task, so the labelled data is typically required. However, the lack of gold standard labelled data sets in customs domain limits the development of supervised-based approach. Our model is developed by the unsupervised mechanism and trained on the unlabelled historical declaration records, which is robust and able to be smoothly adapted by the different customs administrations. Rather than typically classifying whether the HS Code is correct or not, our model predicts the score to indicate the degree of the HS Code being correct. We have evaluated our proposed model on the ground-truth data set provided by Dutch customs officers. Results show promising performance of 71% overall accuracy.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Information and Communication Technolog
HS-stability and complex products in involution semigroups
No full textWhen does the complex product of a given number of subsets of a group generate the same subgroup as their union? We answer this question in a more general form by introducing HS-stability and characterising the HS-stable involution subsemigroup generated by a subset of a given involution semigroup. We study HS-stability for the special cases of regular ∗-semigroups and commutative involution semigroups.</p
Clinical course of peripheral precocious puberty in girls due to autonomous ovarian cysts
No full textObjective: Peripheral precocious puberty (PPP) is the precocious development of secondary sexual characteristics without pulsatile gonadotropin-releasing hormone (GnRH) secretion. In girls, PPP suggests a hyper-oestrogenic state, such as autonomous ovarian cysts and McCune–Albright syndrome (MAS). We aimed to investigate PPP in girls with ovarian cysts, with or without MAS. Design: A retrospective study design was used. Patients and Measurements: The study included 12 girls diagnosed with ovarian cysts with PPP between January 2003 and May 2022. Pelvic sonography was performed in cases of vaginal bleeding or areolar pigmentation in PPP. The clinical characteristics, clinical course and pelvic sonographic findings of girls with ovarian cysts were investigated. Results: We found 18 episodes of ovarian cysts in the 12 girls. The median size of the ovarian cysts was 27.5 mm. Five of the girls were diagnosed with MAS. The median time to spontaneous regression was 6 months. Later, 4 out of 12 girls progressed to central precocious puberty (CPP), and three of them had a recurrence of ovarian cysts. Compared to the non-recurrent and recurrent groups, there was a difference in peak luteinizing hormone (LH) in the GnRH stimulation test and period to cyst regression. Conclusions: Most ovarian cysts in PPP spontaneously disappear. However, this could be one of the findings of MAS. Some girls progress from PPP to CPP. Therefore, follow-up is necessary for ovarian cysts in patients with PPP. The recurrence of ovarian cysts may occur when spontaneous regression is prolonged
DY3+ DOPED GE-GA-SB-SE GLASSES AND OPTICAL FIBERS FOR THE MID-IR GAIN MEDIA
No full textDy3+-doped selenide glasses and their optical fibers in the Ge-Ga-Sb-Se glass-forming system were fabricated and their mid infrared (MIR) emission (2.5-5 mu m) characteristics were analyzed. Optimum concentration for 3 pm emission band was determined as 0.02 mol% due to cross relaxation between Dy3+ ions. Sensitizers such as Pr3+, Ho3+, Tb3+ or Tm3+ ions were co-doped to improve MIR emissions front Dy3+.Pr3+ provided the highest emission intensity of Dy3+:H-6(13/2)-> H-6(15/2) but suffered from the efficient energy transfer between two ions involved. Tm3+ showed further enhancement due to its co-excitation wavelength of 1.8 mu m. (C)2008 The Ceramic Society of Japan. All rights reserved.X1124sciescopu
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