904 research outputs found

    Pointwise convergence of sequential Schr\"odinger means

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    We study pointwise convergence of the fractional Schr\"odinger means along sequences tnt_n which converge to zero. Our main result is that bounds on the maximal function sup⁥n∣eitn(−Δ)α/2f∣\sup_{n} |e^{it_n(-\Delta)^{\alpha/2}} f| can be deduced from those on sup⁥0<t≀1∣eit(−Δ)α/2f∣\sup_{0<t\le 1} |e^{it(-\Delta)^{\alpha/2}} f| when {tn}\{t_n\} is contained in the Lorentz space ℓr,∞\ell^{r,\infty}. Consequently, our results provide seemingly optimal results in higher dimensions, which extend the recent work of Dimou-Seeger, and Li-Wang-Yan to higher dimensions. Our approach based on a localization argument also works for other dispersive equations and provides alternative proofs of previous results on sequential convergence

    Pointwise convergence of sequential Schrödinger means

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    We study pointwise convergence of the fractional Schrödinger means along sequences tn that converge to zero. Our main result is that bounds on the maximal function supn|eitn(−Δ)α/2f| can be deduced from those on sup0<t≀1|eit(−Δ)α/2f| , when {tn} is contained in the Lorentz space ℓr,∞ . Consequently, our results provide seemingly optimal results in higher dimensions, which extend the recent work of Dimou and Seeger, and Li, Wang, and Yan to higher dimensions. Our approach based on a localization argument also works for other dispersive equations and provides alternative proofs of previous results on sequential convergence

    Genome-wide expression patterns associated with oncogenesis and sarcomatous transdifferentation of cholangiocarcinoma

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    BACKGROUND: The molecular mechanisms of CC (cholangiocarcinoma) oncogenesis and progression are poorly understood. This study aimed to determine the genome-wide expression of genes related to CC oncogenesis and sarcomatous transdifferentiation. METHODS: Genes that were differentially expressed between CC cell lines or tissues and cultured normal biliary epithelial (NBE) cells were identified using DNA microarray technology. Expressions were validated in human CC tissues and cells. RESULTS: Using unsupervised hierarchical clustering analysis of the cell line and tissue samples, we identified a set of 342 commonly regulated (>2-fold change) genes. Of these, 53, including tumor-related genes, were upregulated, and 289, including tumor suppressor genes, were downregulated (<0.5 fold change). Expression of SPP1, EFNB2, E2F2, IRX3, PTTG1, PPARÎł, KRT17, UCHL1, IGFBP7 and SPARC proteins was immunohistochemically verified in human and hamster CC tissues. Additional unsupervised hierarchical clustering analysis of sarcomatoid CC cells compared to three adenocarcinomatous CC cell lines revealed 292 differentially upregulated genes (>4-fold change), and 267 differentially downregulated genes (<0.25 fold change). The expression of 12 proteins was validated in the CC cell lines by immunoblot analysis and immunohistochemical staining. Of the proteins analyzed, we found upregulation of the expression of the epithelial-mesenchymal transition (EMT)-related proteins VIM and TWIST1, and restoration of the methylation-silenced proteins LDHB, BNIP3, UCHL1, and NPTX2 during sarcomatoid transdifferentiation of CC. CONCLUSION: The deregulation of oncogenes, tumor suppressor genes, and methylation-related genes may be useful in identifying molecular targets for CC diagnosis and prognosis

    Sequence Variations and Haplotypes of the GJB2 Gene Revealed by Resequencing of 192 Chromosomes from the General Population in Korea

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    ObjectivesHearing impairment (HI) is the most common sensory deficit in human. The Gap Junction Protein, Beta-2 (GJB2) gene encodes the protein connexin 26, and this gene accounts for up to half of the cases of autosomal recessive nonsyndromic HI. This study was conducted to obtain a set of sequence variations (SVs) of the GJB2 gene among Koreans from the general population for making molecular genetic diagnoses and performing genetic counseling.MethodsWe resequenced the GJB2 gene in 192 chromosomes from 96 adult individuals of Korean descent and who were without a history of hearing difficulty. The data of the SVs was obtained and the haplotypes were reconstructed from the data.ResultsFive SVs were observed, including a novel one (c.558G>A; p.T186T), with the allele frequencies ranging from 0.5% (1/192) to 41% (79/192). The linkage disequilibrium study and haplotype construction showed that some of the SVs are in tight linkage, resulting in a limited number of haplotypes.ConclusionWe observed SVs of the GJB2 gene with different allele frequencies, and a limited number of haplotypes were constructed. The data from this study can be used as reference data for GJB2-related hearing genetic studies, including studies on the founder effect and population genetics, and this data is particularly relevant to people of East Asian decent

    PCR Marker-Based Evaluation of the Eating Quality of Japonica Rice (Oryza sativa L.)

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    Evaluation of eating quality in early breeding generations of rice is critical to developing varieties with better palatability. This paper reports DNA markers associated with eating quality of temperate japonica rice and an evaluation method aided by multiple regression analysis. A total of 30 markers comprising STSs, SNPs, and SSRs were tested for their association with palatability using 22 temperate japonica varieties with different palatability values. Eating quality-related traits of the 22 varieties were also measured. Of the 30 markers, 18 were found to be significantly associated with palatability and, consequently, a model regression equation with an R2 value of 0.99 was formulated to estimate the palatability by the marker data set. Validation of the model equation using selected breeding lines indicated that the marker set and the equation are highly applicable to evaluation of the palatability of cooked rice in temperate japonica varieties

    A Case of Pulmonary Arterial Hypertension Associated With Hyperthyroidism, Persistent After Euthyroidism Was Obtained

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    Cardiovascular manifestations in hyperthyroidism occur frequently with various phenotypes. An association between hyperthyroidism and pulmonary arterial hypertension has been reported. In previously reported cases, the hemodynamic and symptomatic recovery of pulmonary arterial hypertension is usually concomitant with achievement of euthyroidism. We report a patient who had pulmonary arterial hypertension associated with Graves' disease, which persisted after euthyroidism was obtained

    Primary Osteosarcoma Arising from the Middle Turbinate in a Pediatric Patient

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    Osteosarcomas usually occur as secondary tumors after radiation therapy or chemotherapy. Without a history of irradiation to the head and neck area, primary osteosarcoma of the turbinate is extremely rare. We report here a rare case of primary turbinate osteosarcoma presenting as a relatively small, well-circumscribed, turbinate mass. Its appearance mimicked a benign nasal mass like mucocele and polyp. We also reviewed the previously reported cases of tumor arising from turbinate
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