85 research outputs found

    Maximum weight triangulation of a special convex polygon

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    In this paper, we investigate the maximum weight triangulation of a special convex polygon, called `semi-circled convex polygon'. We prove that the maximum weight triangulation of such a polygon can be found in O(n2) time.Natural Sciences and Engineering Research Council of CanadaNational Natural Science Foundation of Chin

    Maximum weight triangulation of a special convex polygon

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    In this paper, we investigate the maximum weight triangulation of a special convex polygon, called `semi-circled convex polygon'. We prove that the maximum weight triangulation of such a polygon can be found in O(n2) time.Natural Sciences and Engineering Research Council of CanadaNational Natural Science Foundation of Chin

    The Physical Properties of Star-Forming Galaxies with Strong [O III] Lines at z=3.25

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    We present an analysis of physical properties of 34 [O III] emission-line galaxies (ELGs) at z=3.254±\pm0.029 in the Extended Chandra Deep Field South (ECDFS). These ELGs are selected from deep narrow H2S(1) and broad Ks imaging of 383 arcmin2^{2} obtained with CFHT/WIRCam. We construct spectral energy distributions (SEDs) from U to Ks to derive the physical properties of ELGs. These [O III] ELGs are identified as starburst galaxies with strong [O III] lines of L([O III]) ~ 1042.6^{42.6} - 1044.2^{44.2} erg s1^{-1}, and have stellar masses of M* ~ 109.0^{9.0}-1010.6^{10.6} M_\odot and star formation rates of ~ 10-210 M_\odot yr1^{-1}. Our results show that 24% of our sample galaxies are dusty with Av > 1 mag and EW(OIII)rest_{rest} ~ 70-500 A˚\AA, which are often missed in optically selected [O III] ELG samples. Their rest-frame UV and optical morphologies from HST/ACS and HST/WFC3 deep imaging reveal that these [O III] ELGs are mostly multiple-component systems (likely mergers) or compact. And 20% of them are nearly invisible in the rest-frame UV owing to heavy dust attenuation. Interestingly, we find that our samples reside in an overdensity consisting of two components: one southeast (SE) with an overdensity factor of δgal\delta_{gal} ~ 41 over a volume of 133^{3} cMpc3^{3} and the other northwest (NW) with δgal\delta_{gal} ~ 38 over a volume of 103^{3} cMpc3^{3}. The two overdense substructures are expected to be virialized at z=0 with a total mass of ~ 1.1 x 1015^{15} M_\odot and ~ 4.8 x 1014^{14} M_\odot, and probably merge into a Coma-like galaxy cluster.Comment: 22 pages, 11 figures, 3 tables. Accepted for publication in Ap

    Peritumoral CD16b positive-neutrophil accumulation strongly correlates with regional lymph node metastasis in thoracic esophageal squamous cell cancer

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    BackgroundThe mechanism underlying cancer cell metastasis from the tumor to regional lymph nodes is not yet fully understood. We hypothesized that peritumoral neutrophil accumulation promotes regional lymph node metastasis in thoracic esophageal squamous cell cancer.MethodsBetween 2010 and 2019, 126 thoracic esophageal squamous cell cancer patients received curative (R0) esophagectomy without preoperative treatment in our hospital. Using paraffin-embedded resected tumors, we performed immunohistochemical analysis of CD16b-positive neutrophil accumulation in the peritumoral area, which was defined as a 1-mm region centered on the border separating the malignant cell nests from the host tissue. The relationship between the density of peritumoral CD16b staining and pathological lymph node metastasis or 5-year overall survival was evaluated.ResultsAlthough the clinicopathological characteristics of CD16b-high and CD16b-low patients did not differ, greater pathological lymph node metastasis (P 25 (P < .001). On the other hand, blood neutrophil counts did not correlate with lymph node metastasis

    Exdpf Is a Key Regulator of Exocrine Pancreas Development Controlled by Retinoic Acid and ptf1a in Zebrafish

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    Both endocrine and exocrine pancreatic cells arise from pancreatic-duodenal homeobox 1 (pdx1)-positive progenitors. The molecular mechanisms controlling cell fate determination and subsequent proliferation, however, are poorly understood. Unlike endocrine cells, less is known about exocrine cell specification. We report here the identification and characterization of a novel exocrine cell determinant gene, exocrine differentiation and proliferation factor (exdpf), which is highly expressed in the exocrine cell progenitors and differentiated cells of the developing pancreas in zebrafish. Knockdown of exdpf by antisense morpholino caused loss or significant reduction of exocrine cells due to lineage-specific cell cycle arrest but not apoptosis, whereas the endocrine cell mass appeared normal. Real-time PCR results demonstrated that the cell cycle arrest is mediated by up-regulation of cell cycle inhibitor genes p21Cip, p27Kip, and cyclin G1 in the exdpf morphants. Conversely, overexpression of exdpf resulted in an overgrowth of the exocrine pancreas and a severe reduction of the endocrine cell mass, suggesting an inhibitory role for exdpf in endocrine cell progenitors. We show that exdpf is a direct target gene of pancreas-specific transcription factor 1a (Ptf1a), a transcription factor critical for exocrine formation. Three consensus Ptf1a binding sites have been identified in the exdpf promoter region. Luciferase assay demonstrated that Ptf1a promotes transcription of the exdpf promoter. Furthermore, exdpf expression in the exocrine pancreas was lost in ptf1a morphants, and overexpression of exdpf successfully rescued exocrine formation in ptf1a-deficient embryos. Genetic evidence places expdf downstream of retinoic acid (RA), an instructive signal for pancreas development. Knocking down exdpf by morpholino abolished ectopic carboxypeptidase A (cpa) expression induced by RA. On the other hand, exdpf mRNA injection rescued endogenous cpa expression in embryos treated with diethylaminobenzaldehyde, an inhibitor of RA signaling. Moreover, exogenous RA treatment induced anterior ectopic expression of exdpf and trypsin in a similar pattern. Our study provides a new understanding of the molecular mechanisms controlling exocrine cell specification and proliferation by a novel gene, exdpf. Highly conserved in mammals, the expression level of exdpf appears elevated in several human tumors, suggesting a possible role in tumor pathogenesis

    Actively implementing an evidence-based feeding guideline for critically ill patients (NEED): a multicenter, cluster-randomized, controlled trial

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    Background: Previous cluster-randomized controlled trials evaluating the impact of implementing evidence-based guidelines for nutrition therapy in critical illness do not consistently demonstrate patient benefits. A large-scale, sufficiently powered study is therefore warranted to ascertain the effects of guideline implementation on patient-centered outcomes. Methods: We conducted a multicenter, cluster-randomized, parallel-controlled trial in intensive care units (ICUs) across China. We developed an evidence-based feeding guideline. ICUs randomly allocated to the guideline group formed a local "intervention team", which actively implemented the guideline using standardized educational materials, a graphical feeding protocol, and live online education outreach meetings conducted by members of the study management committee. ICUs assigned to the control group remained unaware of the guideline content. All ICUs enrolled patients who were expected to stay in the ICU longer than seven days. The primary outcome was all-cause mortality within 28 days of enrollment. Results: Forty-eight ICUs were randomized to the guideline group and 49 to the control group. From March 2018 to July 2019, the guideline ICUs enrolled 1399 patients, and the control ICUs enrolled 1373 patients. Implementation of the guideline resulted in significantly earlier EN initiation (1.20 vs. 1.55 mean days to initiation of EN; difference − 0.40 [95% CI − 0.71 to − 0.09]; P = 0.01) and delayed PN initiation (1.29 vs. 0.80 mean days to start of PN; difference 1.06 [95% CI 0.44 to 1.67]; P = 0.001). There was no significant difference in 28-day mortality (14.2% vs. 15.2%; difference − 1.6% [95% CI − 4.3% to 1.2%]; P = 0.42) between groups. Conclusions: In this large-scale, multicenter trial, active implementation of an evidence-based feeding guideline reduced the time to commencement of EN and overall PN use but did not translate to a reduction in mortality from critical illness. Trial registration: ISRCTN, ISRCTN12233792. Registered November 20th, 2017
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