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Programmed cell death ligand-1 (PD-L1) is an ideal checkpoint for immunohistochemical detection. The method of obtaining PD-L1 expression through biopsy can impact the accurate assessment of PD-L1 expression due to the spatial and temporal heterogeneity of tumors. Because of the limited sample size, biopsies often give only a localized picture of the tumor. In this retrospective study, a total of 2,386 metabolic tumor volume (MTV) features were extracted from 18F-FDG PET-CT images. A radiomics model was developed to holistically and non-invasively assess PD-L1 expression in patients with esophageal squamous cell carcinoma by identifying seven independent factors through feature screening. The radiomics model shows effective discrimination, with an area under the receiver operating characteristic curve of 0.888 [95% confidence interval (CI): 0.831–0.945] and 0.889 (95% CI: 0.706–1.000) for the training and validation cohorts, respectively. The results of the decision curve analysis demonstrated that utilizing the radiation model to forecast PD-L1 expression levels yielded more net benefits at threshold probabilities below 0.669. The clinical impact curves demonstrate that when the threshold probability is less than 0.501, the loss-to-benefit ratio is less than one in all cases. [ABSTRACT FROM AUTHOR]

During the transient process of load rejection, the hydraulic pressure applied to the pump-turbine and plant concrete changes dramatically and induces high dynamic stress on the spiral case. The preloading spiral case has been widely used in large-scale pumped-storage power stations due to its excellent load-bearing capacity. However, studies on the impact of preloading pressure on the structural response during load rejection are still few in number. In this paper, 3D flow domain and structural models of a prototype pump-turbine are designed to analyze the hydraulic characteristics and flow-induced dynamic behavior of the preloading steel spiral case under different preloading pressures during load rejection. The results show that the asymmetric design of the logarithmic spiral lines ensures an axially symmetric potential flow within the spiral case domain with uniform pressure distribution. Higher preloading pressure provides larger preloading clearance, leading to greater flow-induced deformation and stress, with their maximum values located at the mandoor and the inner edge, respectively. The combined effect of the asymmetrical shape, internal hydraulic pressure and unbalanced hydraulic force leads to an asymmetrical preloading clearance distribution, resulting in an asymmetrical distribution along the axial direction but a symmetrical characteristic near the waistline of the structural response. Stress variations at sections and between sections share similar characteristics during load rejection. It follows the same trend as the hydraulic pressure under lower preloading pressures, while there is a delayed peak of stress due to the delayed contact phenomenon when the preloading pressure reaches the maximum static head. The conclusions provide scientific guidance for optimizing the preloading pressure selection and structural design for the stable operation of units. [ABSTRACT FROM AUTHOR]

Combustion process of bituminous coal, steam coal, anthracite (AC) and semi-coke were investigated through thermogravimetric analysis method and influence of metamorphic grade as well as heating rate on combustion characteristics were analyzed. Results show that combustion performance could not be represented by single combustion characteristic parameter. Through analysis of comprehensive combustion characteristic indexes, with increase of metamorphic grade combustion performance of coal is lowered, and combustion performance of semi-coke and AC are close to each other. With increase of heating rate, combustion curves move into high temperature region and comprehensive combustion characteristic indexes are increased, which show that the combustion performance is improved. Random pore model (RPM), unreacted shrinking core model (URCM) and volume model were used to calculate kinetic parameters of combustion process. Results show that RPM has the best performance to represent combustion process of the four samples and through calculation by RPM kinetic energy of combustion process for all samples are between 43.08 and 99.43 kJ/mol, and there is compensation effect during combustion process.

An investigation had been made into the insect communities in Hohhot farmland. Between January and December 2011-2012, in order to approach the effects of different habitat types in Hohhot on insect diversity, an investigation was conducted on the insects in four types of habitats in Hohhot, Inner Mongolia. On the basis of a comprehensive investigation, combined with the Shannon-Wiener diversity index, evenness index, dominance index, the systematic analysis of Hohhot, the insect community composition in different seasons. A total of 5305 insects were collected , belonging to 164 species, 75 families and 11 orders, among which, Orthoptera, Hemiptera, Coleoptera, Diptera, Hymenoptera were the dominant taxa. The insect species diversity and evenness, summer>autumn>spring; dominance, spring>autumn>summer.

Poly(trimethylene terephthalate)-poly(ethylene oxide terephthalate) block copolymer (PTG)/multiwalled carbon nanotubes (MWCNTs) composites were prepared via in situ polymerization. To improve the dispersion of MWCNTs in the PTG matrix, the poly(ethylene glycol)-grafted multiwalled carbon nanotubes (MWCNT-PEG) were produced by the 'graft to' method. The transmission electron microscopy observation demonstrated that a homogeneous dispersion of MWCNT-PEG was obtained. As a consequence, the percolation threshold for the rheology was around 0.5 wt% and the conductivity was ~1 wt%, respectively. Differential scanning calorimetry and polarized optical microscopy results confirmed that MWCNT-PEG can act as an effective heterogeneous nucleating agent. Interestingly, the effects of MWCNT-PEG on crystallization and melting of the poly(ethylene oxide terephthalate) blocks were more pronounced than on those of the PTT blocks. POLYM. ENG. SCI., 53:914-922, 2013. © 2012 Society of Plastics Engineers, INTRODUCTION Since the discovery of carbon nanotubes (CNTs) in 1991 by Iijima (1), the properties and application of carbon nanotubes and related materials have been very active research fields over [...]

In this article, the particular phase morphology of immiscible polyamide 12/polystyrene (PAl2/PS) blends prepared via in situ anionic ring-opening polymerization of laurolactam (LL) in the presence of polystyrene (PS) was investigated. Scanning electron microscopy (SEM) and Fourier Transform infrared Spectroscopy (FTIR) were used to analyze the morphology of the blends. The results show that the PS is dispersed as small droplets in the continuous matrix of PAl2 when PS content is 5 wt%. However, when the PS content is higher than 10 wt%, two particular phase morphologies appeared. Firstly, dispersed PS-rich particles with the spherical inclusions of PAl2 can be found when PS content is between 10 and 15 wt%. Then the phase inversion occurred (the phase morphology of the PAl2/PS blends changed from the PS dispersed/PAl2 matrix to PAl2 dispersed/PS matrix system) when PS content is 20 wt% or higher, which is unusual for polymer blends prepared via conventional methods such as mixing, hydrolytic polycondensation and so on. The formation of this particular phase morphology development was simply elucidated via a phase inversion mechanism. Furthermore, the stability of the phase morphology of the PAl2/PS blends after annealing at 230°C was also investigated via SEM. POLYM. ENG. SCI., 52:1831-1838, 2012. © 2012 Society of Plastics Engineers, INTRODUCTION The blending of miscible polymers for production of new tailor made materials at low cost has gained great interest in recent years, as this enables getting better mechanical properties [...]

Nylon 12 blends (BP) with nitrile-butadiene ultrafine full-vulcanized powdered rubber (NBUFPR) were successfully synthesized in a corotating intermeshing twin screw extruder via anionic ring-opening polymerization of lauryllactam at 250°C. The in situ formed blends were characterized by mechanical test, fourier transform infrared spectroscopy, scanning electron microscopy, and thermogravimetric analysis. A brittle-tough transition occurs when NBUFPR content is 4 wt%. And the notched Izod impact strength achieves 989 J [m.sup.-1] when 5 wt% NBUFPR was added. Because of the good dispersion property of NBUFPR during the process of reactive extrusion, the interparticle distance decrease remarkably. Besides, the in situ formed NBUFPR--PA12 leads to better adhesion between the two phases. For comparison, another series of blends (BL) were also prepared by melt blending hydrolytic-polymeric PA12 and NBUFPR in the same twin screw extruder. Brittle-tough transition did not appear in BL blends within the same range of NBUFPR content. POLYM. ENG. SCI., 50:1178-1185, 2010. [C]2010 Society of Plastics Engineers, INTRODUCTION The rapid anionic polymerization of lactams has received considerable attention since its discovery in the 1950s (1-27). Fast reaction kinetics, clean polymerization reaction without any by-products and a crystalline [...]