基于Flowmaster液环真空泵系统运行性能的研究（英文）

目前液环真空泵系统的研究主要侧重于实际应用方面,有关系统性能的基础研究非常有限。本文采用流动系统模拟软件Flowmaster对液环真空泵系统进行建模计算,探讨了系统运行工况与液环泵性能和装置性能的相互关系,得到了液环泵参数(转速、叶轮尺寸)和装置参数(管路长度、管路内径、阀门开度、被抽容器压力)对液环真空泵系统运行工况及性能的影响规律,为工程设计及应用提供理论依据。

基于DPM模型的离心泵非定常固液两相流及磨损计算（英文）

In this paper, the discrete phase model （DPM） and semi-empirical wear model were used to simulatethe unsteady solid-liquid two-phase flows and wear in a centrifugal pump, to explore the solid particle movementand the wear of the pump. The liquid phase was solved by the fluid governing equations in the Euler coordinatesystem; the solid particle phase was treated as a discrete medium and solved by the equations of particle motion inLagrange coordinate. The solid-liquid phase coupling was performed using iterative numerical method. An IS typecentrifugal pump was selected in the simulation. Water and sand particle were chosen as the continuous phase andthe discrete phase, respectively. The particle volumetric ratio at the pump inlet was in the range of 0.5%-3%with the particle size of 0.05-0.2 mm. The flow characteristics of the solid-liquid two-phase flows, the trajectoryof the particle cluster and the distribution of wear rate in the centrifugal pump were obtained by the simulation.

Bacterial outer membrane vesicles-based therapeutic platform eradicates triple-negative breast tumor by combinational photodynamic/chemo-/immunotherapy

Bacterial outer membrane vesicles(OMVs)are potent immuno-stimulating agents and have the potentials to be bioengineered as platforms for antitumor nanomedicine.In this study,OMVs are demonstrated as promising antitumor therapeutics.OMVs can lead to beneficial M2-to-M1 polarization of macrophages and induce pyroptosis to enhance antitumor immunity,but the therapeutic window of OMVs is narrow for its toxicity.We propose a bioengineering strategy to enhance the tumor-targeting ability of OMVs by macrophage-mediated delivery and improve the antitumor efficacy by co-loading of photosensitizer chlorin e6(Ce6)and chemotherapeutic drug doxorubicin(DOX)into OMVs as a therapeutic platform.We demonstrate that systemic injection of the DOX/Ce6-OMVs@M therapeutic platform,providing combinational photodynamic/chemo-/immunotherapy,eradicates triple-negative breast tumors in mice without side effects.Importantly,this strategy also effectively prevents tumor metastasis to the lung.This OMVs-based strategy with bioengineering may serve as a powerful therapeutic platform for a synergic antitumor therapy.

Modulation of expression of P16 and Her2 in rat breast tissues of mammary hyperplasia model by external use of Rupifang Extract

tract in external use on expression of proto-onco- genes her2 and tumor suppression genes p16 in rat breast tissues of mammary hyperplasia model. To explore the mechanisms of Rupifang Extract in external use for preventing and treating mammary hyperplasia. METHODS Thirty virginal female Wistar rats were randomized into 5 groups, 6 in each, A： blank con- trol group; B： model group; C： the low dose group of Rupifang; D： the middle dose group of Rupifang; and E： The high dose group of Rupifang. The mam- mary hyperplasia rat models were produced by in- jecting estradiol benzoate and progesterone and ir- ritating by tail nipping. Drug intervention was also launched during the model formation. After 30 days, the expression of her2 and p16 in breast tis- sues of rats in each group were detected by the SP immunohistochemical method. RESULTS： Compared with Blank control group, the expression of her2 in breast tissues in Model group was higher, and the expression of p16 was lower （P〈O.05 or P〈O.01）. After intervention with Rupi- fang Extract, compared with Model group, the ex- pression of her2 in breast tissues in Rupifang groups was lower, and the expression of p16 higher （P〈O.05 or P〈O.01）. CONCLUSION： The mechanisms of Rupifang Ex- tract in external application for preventing and treating mammary hyperplasia may be reducing the expression of proto-oncogenes her2 and in- creasing the expression of tumor suppression genes p16.

Construction of Magnetic Resonance Imaging Visible Polymeric Vector for Efficient Tumor Targeted siRNA Delivery

RNA interference(RNAi),known for the highly efficient targeted gene silencing,has been demonstrated to be a promising means for cancer treatment.Meanwhile,an effective approach for siRNA delivery is urgently needed to meet the needs for its clinical application.Herein,we constructed a polymeric vector labeled with superparamagnetic iron oxide(SPIO)for magnetic resonance imaging(MRI)visible siRNA delivery.EGFR antibody was also modified to the surface of nanodrug to enhance the delivery effect.Our results showed that the vector exhibited great siRNA complexation ability and mediated an increased endocytosis of siRNA without obvious cytotoxicity.Besides,both in vitro and in vivo studies evidenced the vector could effectively deliver siRNA into tumor cells,exert highly interfering effect,and show potent MR imaging capacity.The study provides a promising MRI-visible and EGFR targeting delivery system to improve RNAi efficacy for cancer therapy.

Modeling study of source contributions and emergency control effects during a severe haze episode over the Beijing-Tianjin-Hebei area

In February 2014, the Beijing-Tianjin-Hebei(BTH) area experienced a weeklong episode of heavy haze pollution. Cities such as Beijing(BJ) and Shijiazhuang(SJZ) issued heavy pollution alerts for the first time and took emergency control measures. This study employed the Nested Air Quality Prediction Modeling System(NAQPMS) to simulate and analyze the three-dimensional structure of the source contributions of PM2.5 in the BTH area during this pollution episode and quantitatively assessed the effects of the emergency control measures. The results showed that during the polluted period(February 19–26), surface PM2.5 mainly originated from local sources(48%–72%). In the entire BTH area, southern Hebei(SHB) represented the largest internal contribution(33%), while the main external contributions came from Shandong(SD)(10%) and Henan(HN)(4%). Vertically, the local contribution was constrained below the near-ground layer, and rapidly decreased with altitude. The regional transport path from SHB and Shanxi(SX) to BJ appeared at 0.5–1.5 and 1.5–2.5 km, with contributions of 32%–42% and 13%–27%, respectively. The non-local source regions for the BTH area were SD below 1 km and mainly SX and HN above 1 km. Compared to the non-polluted period(February 27–28), the contribution from regional transport increased during the polluted period, indicating the key role of regional transport in the pollution formation. The emergency control measures had a relatively large effect on NOx and SO2 concentrations, but a limited effect on PM2.5. The stronger regional transport during the polluted period may have weakened the effects of the local emergency control measures. These results indicated that a coordinated emission control should be implemented not only over the BTH area but also over its surrounding provinces(e.g. SD, HN).

Wear calculation of sandblasting machine based on EDEM-FLUENT coupling

Sandblasting machines are widely used in chemical, mechanical and other engineering fields. The internal flow field of the sandblasting machine belongs to a complex gas-solid two-phase flow, and impact by the continuous abrasive sand can cause the machine to wear or even fail. In this study, the EDEM-FLUENT coupling method was used to calculate the transient flow field of the gas phase and the motion, dynamic and collision characteristics of the sand. Air in the sandblasting machine was treated as the ideal gas and the continuous phase. The sand was regarded as the discrete phase solid in the computation. Using the Archard wear model, the wear amount of the sandblasting machine was calculated and the wear law was analysed, to provide a theoretical basis for optimising the design and operation method of the blasting machine.

Wear calculation of sandblasting machine based on EDEM-FLUENT coupling

Sandblasting machines are widely used in chemical,mechanical and other engineering fields.The internal flow field of the sandblasting machine belongs to a complex gas-solid two-phase flow,and impact by the continuous abrasive sand can cause the machine to wear or even fail.In this study,the EDEM-FLUENT coupling method was used to calculate the transient flow field of the gas phase and the motion,dynamic and collision characteristics of the sand.Air in the sandblasting machine was treated as the ideal gas and the continuous phase.The sand was regarded as the discrete phase solid in the computation.Using the Archard wear model,the wear amount of the sandblasting machine was calculated and the wear law was analysed,to provide a theoretical basis for optimising the design and operation method of the blasting machine.