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We present a method to calculate the energy gap of a charge-neutral excitation using only ground-state calculations. We report Quantum Monte Carlo calculations of $\Gamma\rightarrow\Gamma$ and $\Gamma\rightarrow X$ particle-hole excitation energies in diamond carbon. We analyze the finite-size effect and find the same $1/L$ decay rate as that in a charged excitation, where L is the linear extension of the supercell. This slow decay is attributed to the delocalized nature of the excitation in supercells too small to accommodate excitonic binding effects. At larger system sizes the apparent $1/L$ decay crosses over to a $1/L^3$ behavior. Estimating the scale of exciton binding can be used to correct finite-size effects of neutral gaps.

Synergistic strengthening is increasingly explored for developing high-performance copper matrix composite. In this work, the hybrid copper matrix composites reinforced with carbon nanotubes (CNTs) and micro- TiB2 particles（（CNTs-TiB2）/Cu composites）were prepared by electroless copper plating, powder metallurgy and hot extrusion. The arc erosion resistance of the hybrid copper matrix composites was studied in JF04C electrical contact testing system. And the synergistic effect of CNTs and TiB2 particles in different content ratios on the arc erosion resistance of composites was analyzed emphatically. The action mechanism of CNTs and TiB2 particles in arc erosion process is discussed in detail. Results show that the arc duration and arc energy of the hybrid copper matrix composites are lower than that of copper matrix composites single reinforced with CNTs or TiB2 particles. When the volume fraction of CNTs is 4.2% (The content of TiB2 particles is 1.6%), the arc erosion resistance of the hybrid copper matrix composites is optimal. In arc erosion process, CNTs can form a network structure parallel to the extrusion direction in copper matrix, and the continuous CNTs network structure can effectively disperse cathode arc, promote arc movement, increase work function of copper matrix composites, inhibit electron emission and reduce total emission current density. And the micro- TiB2 particles are helpful to improve the viscosity of molten pool, which can reduce the material mass loss and erosion pit on the surface of composites. Under the combined actions of CNTs and TiB2 particles (4.2CNTs-1.6TiB2)/Cu composite presents better arc erosion resistance stability, lower arc duration and energy.

Xiaoming Wang,* Yunjin Bai,* Facai Zhang, Yubo Yang, Dechao Feng, Ao Li, Zhiqiang Yang, Dengxiong Li, Yin Tang, Xin Wei, Wuran Wei, Ping Han Department of Urology/Institute of Urology, West China Hospital, Sichuan University, Chengdu, Sichuan Province 610041, People’s Republic of China*These authors contributed equally to this workCorrespondence: Ping HanDepartment of Urology/Institute of Urology, West China Hospital, Sichuan University, Chengdu, Sichuan Province 610041, People’s Republic of ChinaTel +86 18980601955Fax +86 28 85582944Email hanpingwch@163.comBackground: Bladder cancer (BC) is a common malignancy worldwide that accounts for 3% of global cancer diagnoses. Chemotherapy resistance limits the therapeutic effect of chemotherapeutic agents in patients with BC. Prolyl 4-hydroxylase, beta polypeptide (P4HB) is an endoplasmic reticulum (ER) chaperone that is upregulated in bladder cancer tissues (The Cancer Genome Atlas, TCGA datasets). Knockdown or suppression of P4HB exerts anticancer activity and sensitizes cells to chemotherapy in various types of cancer.Purpose: We aimed to investigate whether the inhibition of P4HB enhances the anticancer efficacy of gemcitabine (GEM) in BC cells and to study the underlying molecular mechanisms.Patients and Methods: The P4HB mRNA expression levels of 411 BC patients from the TCGA database and P4HB expression level of eighty BC paraffin-embedded samples detected by immunohistochemistry (IHC) staining were used for clinical feature and prognostic analyses. Bioinformatics analysis was utilized for the mechanistic investigation. Highly P4HB-expressed BC cell lines (T24 and 5637) treated with P4HB inhibitor (Bacitracin, BAC) were used to study the effects of BAC on the sensitivity of BC cells to GEM and the potential mechanism. P4HB inhibition experiments were performed in highly P4HB-expressed BC cells, and cell viability, colony formation, cell cycle, reactive oxygen species (ROS), apoptosis and pathway proteins were assessed in T24 and 5637 cells.Results: Western blot analysis showed that P4HB expression was significantly higher in BC tissues than in paired normal tissues. IHC showed that patients with high P4HB expression had a poorer overall survival (OS) rate than those with low P4HB expression. Furthermore, increased P4HB expression was demonstrated to be an independent prognostic marker for BC. Functionally, P4HB inhibition by BAC decreased the cell proliferation ability in vitro. Moreover, BAC treatment sensitized BC cells to GEM. Molecular mechanism analysis indicated that inhibition of P4HB by BAC treatment enhanced the anticancer effects of GEM through increasing cellular ROS content and promoting cell apoptosis and PERK/eIF2α/ATF4/CHOP signaling.Conclusion: High P4HB expression was significantly correlated with poor prognosis in BC patients. Inhibition of P4HB by BAC decreased the cell proliferation ability and sensitized BC cells to GEM by activating apoptosis and the PERK/eIF2α/ATF4/CHOP pathways.Keywords: P4HB, ER stress, bladder cancer, gemcitabine, bacitracin

Synergistic strengthening is increasingly explored for developing high-performance metal matrix composites. In the present work, copper matrix composites reinforced with carbon nanotubes (CNTs) and TiB2 microparticles were fabricated via electroless deposition, powder metallurgy, hot extrusion, and water quenching. The synergistic strengthening effect of the nano-and micro-reinforcements was elaborated and analyzed based on experimental investigation and theoretical calculation. (1CNT-4TiB2)/Cu composite exhibited a better combination of the tensile strength of 375 MPa with elongation of 32.4% than other composites, representing 86.3%, 71.5%, and 22.8% strength increment in comparison with pure Cu, 4TiB2/Cu composite, and 1CNT/Cu composite, respectively. The strengthening efficiency of CNTs in (1CNT-4TiB2)/Cu composite is markedly higher than that in 1CNT/Cu composite (126.7 and 82.3, respectively), confirming the synergistic strengthening effect in enhancing the mechanical properties. Quantitative analysis and experimental characterization indicated that the thermal mismatch and load transfer mechanism of CNTs were the main factors contributing to the tensile strength enhancement of the composite. The synergistic strengthening effect was attributed to that TiB2 microparticles improved the homogeneous dispersion of CNTs, promoting the proportion of thermal mismatch and load transfer mechanisms. The present work may provide a new sight into improving the synergistic strengthening effect in metal matrix composites.

According to the perishable characteristics of refrigerated food and the objective of minimizing the total cost, the mathematical optimization model of cold chain logistics distribution center location problem is established by introducing such constraints as the freshness and time window. In order to solve the problems of slow convergence and easy to fall into local optimal solution in the process of the traditional wolf colony optimization, an immune wolf colony hybrid algorithm is proposed to solve the location problem of distribution center. In this hybrid algorithm, the idea of vaccination of immune algorithm is introduced into the wolf colony algorithm. By adjusting the antibody concentration and selecting immune operator, the diversity of the wolf colony algorithm is improved, and then the search space of the solution is expanded; the convergence speed and solution accuracy of the wolf colony algorithm are improved by using immune memory cells and immune vaccine. The simulation results show that the immune wolf colony algorithm can quickly converge to the global optimal solution and optimize the location model of logistics distribution center. The algorithm has good feasibility and robustness.

In this paper, we propose a verifiable quantum cloud computation scheme based on blind quantum computation which effectively solves the privacy and verifiability problem for clients when interfacing with quantum computer in cloud computation. Different from most of present works (e.g. using brickwork state as resource state), we use cluster state with grid distributed structure to realize the universal and cryptographic calculation which is more suitable for the distributed architecture of cloud computation. Throughout the process, the random key is always held by the client that effectively promote the confidentiality. Moreover, we propose a new method to make the client Alice verifies the correctness of the results through only classical calculation. Security analysis shows that cloud server Bob can only obtain the dimension of input state and cluster state from the calculation, but cannot obtain any information of the input, the output and the algorithm. Dishonest Bob will be detected during the verification.

The physiological changes and the mechanism of stress tolerance in tomato were studied under low temperature and low light conditions. Two growth chamber experiments evaluated three temperatures regimes under standard and relatively low illumination levels with three tomato genotypes. Both experiments used a completely randomized split-plot design (CRD), with temperature regime as the main plot and tomato genotype as the split-plot. The three tomato varieties were “Fenyan No.1”, “SV0313TG”, and “Ousa”. In both experiments, activity of superoxide dismutase (SOD) and peroxidases (POD) in tomato seedlings decreased under low temperature regime and the combination of low temperature and low light. Decreasing temperature had the greatest effect on the increase in enzyme activity. Decrease in POD activity was the greatest under low light and low temperature. The concentration of malondialdehyde (MDA) in plant tissue also decreased under low temperature (20°C/10°C day/night) compared to the standard temperature control (25°C/16°C day/night), but increased at 15°C/5°C day/night temperatures in both experiments and was the greatest under the lowest light and temperature conditions. In both experiments, proline concentrations were the greatest under the standard light intensity (30,000 lux), and proline concentrations increased as temperature decreased. The content of soluble sugar decreased under only low temperature stress but increased under double stresses. The relative value of osmotic potential increased a little under low temperature stress but decreased under double stresses.

Hydroponics has been an increasingly important field of vegetable production. However, a big issue with hydroponics is that certain crops can quickly accumulate high levels of nitrate-N (NO3 ± -N) from the hydroponic system. The objective of this research was to decrease NO3 accumulation and increase the nutritional value and yield of vegetable crops using lettuce and oilseed rape as a model under hydroponic production. In this study, two technologies were applied to leafy vegetable production: 1) using supplementary lighting (blue-violet diode) by manipulating illumination and 2) removing fertilization before harvest for a short term (3 or 5 days), thus providing a practical experiment for improving yield and edible qualities of hydroponic leaf vegetable production. Illumination was applied 4 hours a day (0500–0700 hr and 1700–1900 hr) during good weather, or 12 hours a day during bad weather with insufficient natural light (3 content (26.3% and 30.8%, respectively), and increased total soluble solids (24.1% and 30.6%, respectively). The 5-day fertilizer-free treatment before harvest resulted in 19.2%, 6.4%, and 16.5% yield increases; and 26.0%, 24.3%, and 47.8% NO3 decreases in oilseed rape cultivar Ao-Guan Pakchoi and lettuce cultivars Da-Su-Sheng and Ou-Luo, respectively.