BackgroundOsteosarcoma is the most common bone cancer, mainly occurring in children and adolescents, among which distant metastasis (DM) still leads to a poor prognosis. Although nomogram has recently been used in tumor areas, there are no studies focused on diagnostic and prognostic evaluation of DM in primary osteosarcoma patients.MethodsThe data of osteosarcoma patients diagnosed between 2004 and 2015 were extracted from the Surveillance, Epidemiology, and End Results (SEER) database. Univariate and multivariate logistic regression analyses were used to identify independent risk factors for DM in osteosarcoma patients, and univariate and multivariate Cox proportional hazards regression analyses were used to determine independent prognostic factors of osteosarcoma patients with DM. We then established two novel nomograms and the results were evaluated by receiver operating characteristic (ROC) curves, calibration curves, and decision curve analysis (DCA).ResultA total of 1,657 patients with osteosarcoma were included, and 267 patients (16.11%) had DM at the time of diagnosis. The independent risk factors for DM in patients with osteosarcoma include age, grade, T stage, and N stage. The independent prognostic factors for osteosarcoma patients with DM are age, chemotherapy and surgery. The results of ROC curves, calibration, DCA, and Kaplan–Meier (K-M) survival curves in the training, validation, and expanded testing sets, confirmed that two nomograms can precisely predict occurrence and prognosis of DM in osteosarcoma patients.ConclusionTwo nomograms are expected to be effective tools for predicting the risk of DM for osteosarcoma patients and personalized prognosis prediction for patients with DM, which may benefit clinical decision-making.

The design of high efficiency, high pressure ratio, and wide flow range centrifugal impellers is a challenging task. The paper describes the application of a multiobjective, multipoint optimization methodology to the redesign of a transonic compressor impeller for this purpose. The aerodynamic optimization method integrates an improved nondominated sorting genetic algorithm II (NSGA-II), blade geometry parameterization based on NURBS, a 3D RANS solver, a self-organization map (SOM) based data mining technique, and a time series based surge detection method. The optimization results indicate a considerable improvement to the total pressure ratio and isentropic efficiency of the compressor over the whole design speed line and by 5.3% and 1.9% at design point, respectively. Meanwhile, surge margin and choke mass flow increase by 6.8% and 1.4%, respectively. The mechanism behind the performance improvement is further extracted by combining the geometry changes with detailed flow analysis.

The current understanding of the boundary layer transition is reviewed briefly. The effects of leading edge geometry, inlet turbulence, and surface waviness, on boundary layer transition on a flat plate are predicted using a commercial computational fluid dynamics (CFD) code, STAR-CCM+ which incorporates the γ − R θ correlation model. The investigations on surface waviness were focused on sinusoidal waves with the ratios of wave amplitude to wavelength h/ Lw and wave amplitude to boundary layer displacement thickness h/ δ* in the range 0.0025–0.015 and 0.3–2.8, respectively. It is recommended that in wind tunnel testing/CFD analysis of boundary layer transition, a leading edge aspect ratio of 12 is maintained to avoid significant effect of leading edge geometry. The predictions for the effect of surface waviness on transition for multiple waves, using γ − R θ model, agree well with those using the stability theory. New correlations for the effect of waviness on transition Reynolds number are proposed. The correlations combine the effects of upstream boundary layer displacement thickness, wave height, and wavelength ( h* or h**). It is recommended that a value of h* < 2 or h** < 0.03 is maintained on aircraft surfaces to avoid any significant effect of waviness on drag. The variation of transition Reynolds number with h* for a surface with waviness is of the same order to that on a surface with a forward facing step, but significantly smaller when compared with a surface with a backward facing step (BFS). A value of h* < 0.5 is recommended for a BFS to avoid significant effect on transition.

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Tryptophyllins are a group of small (4-14 amino acids), heterogenous peptides, mostly from the skins of hylid frogs from the genera, Phyllomedusa and Litoria. To date, more than forty TPHs have been discovered in species from these two genera. Here, we describe the identification of a novel tryptophyllin type 3 peptide, PhT-3, from the extracts of skin of the orange-legged monkey frog, Phyllomedusa hypochondrialis, and molecular cloning of its precursor-encoding cDNA from a cDNA library constructed from the same skin sample. Full primary structural characterization was achieved using a combination of direct Edman degradation, mass spectrometry and deduction from cloned skin-derived cDNA. The open-reading frame of the precursor cDNA was found to consist of 63 amino acid residues. The mature peptide arising from this precursor contains a post-translationally modified N-terminal pyroglutamate (pGlu) residue, formed from acid-mediated cyclization of an N-terminal Gln (Q) residue, and with the structure: pGlu-Asp-Lys-Pro-Phe-Trp-Pro-Pro-Pro-Ile-Tyr-Pro-Met. Pharmacological assessment of a synthetic replicate of this peptide on phenylephrine preconstricted rat tail artery segments, revealed a reduction in relaxation induced by bradykinin. PhT-3 was also found to mediate antiproliferative effects on human prostate cancer cell lines.