608 research outputs found

    Temporal and Spatial Dynamics of Carbon Fixation by Moso Bamboo (Phyllostachys pubescens) in Subtropical China

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    To study the temporal and spatial dynamics of carbon fixation by Moso bamboo (Phyllostachys pubescens) in subtropical China, carbon fixation of leaves within the canopy of P. pubescens was measured with a LI-6400 portable photosynthesis system. The results showed that the capability of carbon fixation of P. pubescens leaves had obvious temporal and spatial dynamic variations. It was revealed that there were two peak periods and two low periods in the season variation of carbon fixation capability. Data also revealed that the capability of carbon fixation by five-year-old P. pubescens was more than that of one-year-old and three-year-old. Daily and seasonal carbon fixation showed a negative correlation with the CO2 concentration. The temporal and spatial dynamics of carbon fixation by P. pubescens described above provided a scientific basis for development of technologies in bamboo timber production

    Analyzing and modeling the construction-drive of China

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    2000-2001 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

    Repeatability of Corneal Elevation Maps in Keratoconus Patients Using the Tomography Matching Method

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    To assess repeatability of corneal tomography in successive measurements by Pentacam in keratoconus (KC) and normal eyes based on the Iterative Closest Point (ICP) algorithm. The study involved 143 keratoconic and 143 matched normal eyes. ICP algorithm was used to estimate six single and combined misalignment (CM) parameters, the root mean square (RMS) of the difference in elevation data pre (PreICP-RMS) and post (PosICP-RMS) tomography matching. Corneal keratometry, expressed in the form of M, J0 and J45 (power vector analysis parameters), was used to evaluate the effect of misalignment on corneal curvature measurements. The PreICP-RMS and PosICP-RMS were statistically higher (P < 0.01) in KC than normal eyes. CM increased significantly (p = 0.00), more in KC (16.76 ± 20.88 μm) than in normal eyes (5.43 ± 4.08 μm). PreICP-RMS, PosICP-RMS and CM were correlated with keratoconus grade (p < 0.05). Corneal astigmatism J0 was different (p = 0.01) for the second tomography measurements with misalignment consideration (−1.11 ± 2.35 D) or not (−1.18 ± 2.35 D), while M and J45 kept similar. KC corneas consistently show higher misalignments between successive tomography measurements and lower repeatability compared with healthy eyes. The influence of misalignment is evidently clearer in the estimation of astigmatism than spherical curvature. These higher errors appear correlated with KC progression

    Smad3 promotes cancer progression by inhibiting E4BP4-mediated NK cell development

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    Back-incident SiGe-Si multiple quantum-well resonant-cavity-enhanced photodetectors for 13-mu m operation

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    A back-incident Si-0.65 Ge-0.35/Si multiple quantum-well resonant-cavity-enhanced photodetector operating near 1.3 mum is demonstrated on a separation-by-implantation-oxygen substrate. The resonant cavity is composed of an electron-beam evaporated SiO2-Si distributed Bragg reflector as a top mirror and the interface between the buried SiO2 and the Si substrate as a bottom mirror. We have obtained the responsivity as high as 31 mA/WI at 1.305 mum and the full width at half maximum of 14 nm

    Evaluating the repeatability of corneal elevation through calculating the misalignment between Successive topography measurements during the follow up of LASIK

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    The study aims to evaluate, using the Iterative Closest Point (ICP) algorithm, the repeatability of successive corneal elevation measurements taken post-LASIK. Two topography maps of 98 LASIK participants were recorded preoperatively (Pre), 1 month (Pos1M) and 3 months postoperatively (Pos3M). Elevation of the second measurement was fitted to the first measurement by calculating using ICP, and correcting for, both translational and rotational misalignment components. The RMS of elevation differences between anterior corneal measurements were statistically significant post-LASIK compared to preoperation (P < 0.05). A misalignment ratio used to describe the weighting of the elevation difference caused by misalignment relative to the total difference remained stable (0.40 and 0.23 for anterior and posterior corneal surfaces, respectively) in different periods. The study also considered the combined misalignment parameter (CM), which represents the total effect of all individual misalignment components on the repeatability of corneal topography maps. CM was significantly greater post-LASIK relative to pre-LASIK (P < 0.05). Overall, the contribution of misalignment to the total difference between successive corneal measurements remained stable pre and post operation, while the combined effect of refractive error correction and optical diameter appeared to have a significant influence on the elevation repeatability in the early stages of the follow up period

    Enhanced Recovery After Surgery Program in Patients Undergoing Pancreaticoduodenectomy A PRISMA-Compliant Systematic Review and Meta-Analysis

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    Enhanced recovery after surgery (ERAS) pathways are multimodal, evidence-based approaches to optimize patient outcome after surgery. However, the use of ERAS protocols to improve morbidity and recovery time without compromising safety following pancreaticoduodenectomy (PD) remains to be elucidated. We conducted a systemic review and meta-analysis to assess the safety and efficacy of ERAS protocols compared with conventional perioperative care (CPC) in patients following PD. PubMed, Medline, Embase, and Science Citation Index Expanded and Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library were searched between January 2000 and June 2015. The patients who underwent PD with ERAS protocols or CPC were eligible. The studies that compared postoperative length of hospital stay (PLOS), postoperative complications, or in-hospital costs in the 2 groups were included. A meta-analysis, meta-regression, sensitivity analysis, and subgroup analysis were performed to estimate the postoperative outcomes between the 2 groups and identified the potential confounders. We used the methodological index for nonrandomized studies checklist to assess methodological qualities. Weighted mean differences (WMD) or odds ratios (OR) were calculated with their corresponding 95% confidence intervals (CI). The publication bias tests were also performed through the funnel plots. In total, 14 nonrandomized comparative studies with 1409 ERAS cases and 1310 controls were analyzed. Implementation of an ERAS protocol significantly reduced PLOS (WMD: −4.17 days; 95%CI: −5.72 to −2.61), delayed gastric emptying (OR: 0.56; 95%CI: 0.44–0.71), overall morbidity (OR: 0.63; 95% CI: 0.54–0.74), and in-hospital costs compared to CPC (all P < 0.001). There were no statistically significant differences in other postoperative outcomes. Age, gender, and ERAS component implementation did not significantly contribute to heterogeneity for PLOS as shown by meta-regression analysis. Our study suggested that ERAS was as safe as CPC and improved recovery of patients undergoing PD, thus reducing in-hospital costs. General adoption of ERAS protocols during PD should be recommended

    Decomposition of Gene Expression State Space Trajectories

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    Representing and analyzing complex networks remains a roadblock to creating dynamic network models of biological processes and pathways. The study of cell fate transitions can reveal much about the transcriptional regulatory programs that underlie these phenotypic changes and give rise to the coordinated patterns in expression changes that we observe. The application of gene expression state space trajectories to capture cell fate transitions at the genome-wide level is one approach currently used in the literature. In this paper, we analyze the gene expression dataset of Huang et al. (2005) which follows the differentiation of promyelocytes into neutrophil-like cells in the presence of inducers dimethyl sulfoxide and all-trans retinoic acid. Huang et al. (2005) build on the work of Kauffman (2004) who raised the attractor hypothesis, stating that cells exist in an expression landscape and their expression trajectories converge towards attractive sites in this landscape. We propose an alternative interpretation that explains this convergent behavior by recognizing that there are two types of processes participating in these cell fate transitions—core processes that include the specific differentiation pathways of promyelocytes to neutrophils, and transient processes that capture those pathways and responses specific to the inducer. Using functional enrichment analyses, specific biological examples and an analysis of the trajectories and their core and transient components we provide a validation of our hypothesis using the Huang et al. (2005) dataset

    Observation of a ppb mass threshoud enhancement in \psi^\prime\to\pi^+\pi^-J/\psi(J/\psi\to\gamma p\bar{p}) decay

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    The decay channel ψπ+πJ/ψ(J/ψγppˉ)\psi^\prime\to\pi^+\pi^-J/\psi(J/\psi\to\gamma p\bar{p}) is studied using a sample of 1.06×1081.06\times 10^8 ψ\psi^\prime events collected by the BESIII experiment at BEPCII. A strong enhancement at threshold is observed in the ppˉp\bar{p} invariant mass spectrum. The enhancement can be fit with an SS-wave Breit-Wigner resonance function with a resulting peak mass of M=186113+6(stat)26+7(syst)MeV/c2M=1861^{+6}_{-13} {\rm (stat)}^{+7}_{-26} {\rm (syst)} {\rm MeV/}c^2 and a narrow width that is Γ<38MeV/c2\Gamma<38 {\rm MeV/}c^2 at the 90% confidence level. These results are consistent with published BESII results. These mass and width values do not match with those of any known meson resonance.Comment: 5 pages, 3 figures, submitted to Chinese Physics
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