A new laser-driven proton therapy facility is being designed by Peking University. The protons will be produced by laser–plasma interaction, using a 2-PW laser to reach proton energies up to 100 MeV. ...We hope that the construction of this facility will promote the real-world applications of laser accelerators. Based on the experimental results and design experience of existing devices in Peking University, we propose a beam transmission system which is suitable for the beam produced by laser acceleration, and demonstrate its feasibility through theoretical simulation. It is designed with two transport lines to provide both horizontal and vertical irradiation modes. We have used a locally-achromatic design method with new canted-cosine-theta (CCT) magnets. These two measures allow us to mitigate the negative effects of large energy spread produced by laser-acceleration, and to reduce the overall weight of the vertical beamline. The beamline contains a complete energy selection system, which can reduce the energy spread of the laser-accelerated beam enough to meet the application requirements. The users can select the proton beam energy within the range 40–100 MeV, which is then transmitted through the rest of the beamline. A beam spot with diameter of less than 15 mm and energy spread of less than 5% can be provided at the horizontal and vertical irradiation targets.
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•The nanocomposites porous C/TiO2 film were fabricated via PIPS method.•The HRTEM reveals the size of carbon nanoparticles is about 1.1nm.•The PVP advantages residual carbon content but suppresses ...its crystallization.•The film exhibits high α (0.928–0.959) with low ε (0.074–0.105) for single layer.
Newly proposed selective solar absorbers of porous carbon–titania nanocomposite films with a well-defined interconnected macropores structure were prepared via a polymer-assisted photopolymerization-induced phase-separation method. The microstructure and optical properties of as-deposited nanocomposite films were characterized and discussed in detail. The results show that non-ionic water-soluble polymer polyvinylpyrrolidone works as a sol modifier advantaging the mean size of the interconnected macropores, residual carbon content, and films thickness, but suppresses the order degree of the carbon remained in the films. The high-resolution transmission electron microscopy demonstrated that a small amount of graphite particles with size of around 1.1nm embedded in the cavity of the porous while the wall of the porous consists of amorphous carbon and titania composites. The single layer of as-prepared porous C/TiO2 nanocomposite films exhibits high solar absorptance (α=0.928–0.959) with low thermal emittance (ε=0.074–0.105), yielding an optimized photothermal conversion efficiency η=α−ε of 0.864 corresponding to a film thickness of around 338nm, indication of such film is fair enough to serve as an excellent solar absorber.
PURPOSE:To quantify retinal microvasculature within the macular ganglion cell-inner plexiform layer (GCIPL) in primary open-angle glaucoma (POAG) and normal eyes, determine association of vessel ...parameters with structural and functional measures, and report diagnostic accuracy of vessel parameters.
METHODS:POAG and normal patients underwent 6×6 mm macula scans Angioplex optical coherence tomography angiography (OCTA); Cirrus HD-OCT 5000; and Humphrey Field Analyzer II-i 24-2 visual field (VF). Prototype software performed semiautomatic segmentation to create GCIPL en face images, and quantified vessel area density (VAD), vessel skeleton density (VSD), and vessel complexity index (VCI) for the macula (globally, hemifields, and 6 focal sectors). Linear regression assessed association of OCTA parameters with VF mean deviation (MD) and GCIPL thickness globally and focally.
RESULTS:A total of 34 POAG and 21 normal eyes were studied. VAD, VSD, and VCI were reduced in POAG versus normal (0.463 vs. 0.486, P=0.00029; 0.230 vs. 0.219, P=0.0014; 1.15 vs. 1.09, P=0.0044, respectively), with a trend of worsening with increased POAG severity. Reduced global VF MD was associated with reduced VAD and VCI, controlling for age and intereye correlation (P=0.0060, 0.0080; R=0.205, 0.211). Both superior and inferior hemifield MD were associated with corresponding VAD, VSD, and VCI (all P<0.007; R ranged from 0.12 to 0.29). Global GCIPL thickness was not associated with global OCTA parameters, and only inferior sector GCIPL thickness was associated with corresponding VAD, VSD, and VCI (P<0.05; R ranged from 0.15 to 0.16). Area under curves for VAD, VSD, and VCI were fair to good (0.83, 0.79, 0.82; respectively; P<0.0001).
CONCLUSIONS:Glaucomatous eyes had reduced GCIPL microcirculation. OCTA parameters had stronger associations with functional rather than structural measures of glaucoma. This observation deserves further study.
Coatings of porous ceramic foams have potential applications in thermal protection systems of space shuttles. This paper develops a mechanics model for evaluation of thermal stress of porous ceramic ...foam coating/substrate structures under thermal shock temperature variation. Numerical results show that interfacial stresses exhibit singularity at the edge of ceramic foam coating. Stress intensity factor will reduce when ceramic foam coating has a larger density or a larger thermal conductivity. Comparison between beam model and membrane model is made and it suggests that consideration of bending stiffness is essential for correct evaluation of the thermal stress in the ceramic foams.
•Power output of a porous annular thermoelectric generator (TEG) is evaluated.•Analytical and simplified expressions of power output are derived.•Effect of gas velocity on the power output is ...relatively insignificant.•The optimized porosity of TEG for maximum power output is given.
Comparing with traditional thermoelectric generators (TEGs) heating a solid body and extracting heat indirectly, porous TEGs can directly extract heat from gaseous/liquid medias and convert them into electric power. This paper considers the electrical and thermal contact resistances between the heat source/heat sink and TEG, and evaluates the power output of a porous annular TEG for waste heat harvesting. A theoretical model for the effects of gas velocity, the external resistance, porosity and the electrical/thermal contact resistances on power output is proposed. Analytical and simplified expressions of power output are derived. The analysis demonstrates that the porous structure can significantly enhance the performance of TEG comparing to the bulk TEG. It is found that power output is proportional to the temperature difference across the TEG and inversely proportional to the cross-sectional area of the TEG. Effect of gas velocity on the power output is relatively insignificant. The power output increases to a peak value and then decreases with porosity, external electrical resistance and cross section area of TEG. The optimized area of cross section and porosity of TEG for maximum power output are given. With the increase of external electrical resistance, porosity should be enhanced to obtain the maximum power output. Relation between the optimized porosity and pore diameter of sample is presented.
Recognition and elimination of malignant cells by cytotoxic T lymphocytes depends on antigenic peptides generated by proteasomes. It has been established that impairment of the immunoproteasome ...subunits, that is, PSMB8, PSMB9 and PSMB10 (PSMBs), is critical for malignant cells to escape immune recognition. We report here the regulatory mechanism of the repression of PU.1-dependent activation of PSMBs by PML/RARα in the pathogenesis of acute promyelocytic leukemia (APL) and the unidentified function of all-trans retinoic acid (ATRA) as an immunomodulator in the treatment of APL. Chromatin immunoprecipitation and luciferase reporter assays showed that PU.1 directly bound to and coordinately transactivated the promoters of PSMBs, indicating that PSMBs were transcriptional targets of PU.1 and PU.1 regulated their basal expression. Analysis of expression profiling data from a large population of acute myeloid leukemia (AML) patients revealed that the expression levels of PSMBs were significantly lower in APL patients than in non-APL AML patients. Further evidence demonstrated that the decrease in their expression was achieved through PML/RARα-mediated repression of both PU.1-dependent transactivation and PU.1 expression. Moreover, ATRA but not arsenic trioxide induced the expression of PSMBs in APL cells, indicating that ATRA treatment might activate the antigen-processing/presentation machinery. Finally, the above observations were confirmed in primary APL samples. Collectively, our data demonstrate that PML/RARα suppresses PU.1-dependent activation of the immunosubunits, which may facilitate the escape of APL cells from immune surveillance in leukemia development, and ATRA treatment is able to reactivate their expression, which would promote more efficient T-cell-mediated recognition in the treatment.
Previous studies have reported the adverse cognitive effects of high folate status in older individuals with vitamin B12 (VB12) deficiency. Thus, the aim of this study was to investigate how high ...serum folate and VB12 deficiency could collaboratively aggravate neuronal degeneration. In total, 146 older non-demented diabetic individuals with an average age of 75 ± 3.9 were recruited. VB12 deficiency and high folate status were based on high serum methylmalonic acid (MMA) concentrations (> 0.3 μmol/L) and the serum folate concentration being in the top tertile (> 31.4 nmol/L) respectively. Among these subjects, there were 20 with elevated MMA and high folate. The structural magnetic resonance imaging data of these subjects were analyzed by performing flexible factorial analysis with the “folate level” and “MMA level” added as main effects, and the interaction effect of folate and VB12 on brain volume was evaluated. The results showed significant gray matter atrophy of the right middle occipital gyrus and the opercular part of the inferior frontal gyrus in subjects with a simultaneous high folate status and VB12 deficiency. Together with previous observational studies on cognitive function, this study lends support to the notion that high serum folate concentrations in older people with VB12 deficiency may be associated with increased neurodegeneration..
► We develop a decomposition-based approach (DBA) for flexible flow shop scheduling. ► DBA combines and exploits SPT rule and GA to deal with stochastic processing times. ► A neighbouring K-means ...clustering algorithm groups machines into clusters. ► Two back propagation networks assigns either SPT or GA to solve each machine cluster. ► DBA outperforms SPT and GA alone for FFS scheduling with stochastic processing times.
Flexible flow shop scheduling problems are NP-hard and tend to become more complex when stochastic uncertainties are taken into consideration. Although some methods have been developed to address such problems, they remain inherently difficult to solve by any single approach. This paper presents a novel decomposition-based approach (DBA), which combines both the shortest processing time (SPT) and the genetic algorithm (GA), to minimizing the makespan of a flexible flow shop (FFS) with stochastic processing times. In the proposed DBA, a neighbouring K-means clustering algorithm is developed to firstly group the machines of an FFS into an appropriate number of machine clusters, based on their stochastic nature. Two optimal back propagation networks (BPN), corresponding to the scenarios of simultaneous and non-simultaneous job arrivals, are then selectively adopted to assign either SPT or GA to each machine cluster for sub-schedule generation. Finally, an overall schedule is generated by integrating the sub-schedules of machine clusters. Computation results show that the DBA outperforms SPT and GA alone for FFS scheduling with stochastic processing times.
The family of polypeptide N-acetylgalactosaminyltransferases (GalNAc-Ts) is responsible for the altered glycosylation in cancer. The purpose of our study was to investigate the clinical significance ...of two isoforms, GalNAc-T6 and -T3, and their correlation with the prognosis of pancreatic cancer.
Immunohistochemistry was used to analyse GalNAc-T6 and -T3 expressions in 70 clinicopathologically characterised pancreatic cancer cases.
Positive expressions of GalNAc-T6 and -T3 were immunohistochemically identified in 51% (36 of 70) and in 77% (54 of 70) of patients, respectively. A close relationship was noted between GalNAc-T6 positive expression and pathological well/moderate differentiated type (P=0.001), small tumour size (P=0.044), absence of vascular invasion (P=0.009), and low stage of the American Joint Committee on Cancer systems (P=0.043). The expression of GalNAc-T3 significantly correlated with good differentiation (P=0.001), but not with other clinicopathologic features. Furthermore, univariate and multivariate analyses revealed that GalNAc-T6 expression was an independent prognosis indicator for the disease, whereas GalNAc-T3 expression had no impact on clinical outcome, even though 33 of 36 GalNAc-T6-positive cases also had a positive expression of GalNAc-T3 (P=0.001, r=0.356).
Both GalNAc-T6 and -T3 expressions correlated significantly with tumour differentiation, whereas only GalNAc-T6 expression predicted prognosis in pancreatic cancer.
Tuberculosis (TB) affects people globally and is being reconsidered as a serious public health problem in China. Reliable forecasting is useful for the prevention and control of TB. This study ...proposes a hybrid model combining autoregressive integrated moving average (ARIMA) with a nonlinear autoregressive (NAR) neural network for forecasting the incidence of TB from January 2007 to March 2016. Prediction performance was compared between the hybrid model and the ARIMA model. The best-fit hybrid model was combined with an ARIMA (3,1,0) × (0,1,1)12 and NAR neural network with four delays and 12 neurons in the hidden layer. The ARIMA-NAR hybrid model, which exhibited lower mean square error, mean absolute error, and mean absolute percentage error of 0·2209, 0·1373, and 0·0406, respectively, in the modelling performance, could produce more accurate forecasting of TB incidence compared to the ARIMA model. This study shows that developing and applying the ARIMA-NAR hybrid model is an effective method to fit the linear and nonlinear patterns of time-series data, and this model could be helpful in the prevention and control of TB.
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