可见光响应的碳修饰纳米棒状p型CaFe_2O_4半导体光催化降解有机污染物（英文）

制备了C/CaFe_2O_4纳米棒复合材料,并考察了其光催化性能,同时深入研究了C修饰对CaFe_2O_4活性的影响.研究发现,复合材料的光催化降解活性与C和CaFe_2O_4的质量比密切相关.其最佳的碳含量为58 wt%,所得复合光催化剂对亚甲基蓝(MB)的降解速率常数达到0.0058 min^(-1),是铁酸钙的4.8倍.进一步研究表明,C修饰在CaFe_2O_4表面显著提高了样品对亚甲基蓝染料的吸附性能.吸附等温线结果发现,MB以单分子层形式吸附于CaFe_2O_4表面.总体而言,C覆盖在CaFe_2O_4表面可以使光生电子和空穴更有效的分离和传输,可以显著提高催化剂对MB的吸附性能,还可以增强样品对光的吸收能力,因而催化剂光催化降解MB性能增加.表征结果表明,复合光催化剂表面含有大量羧基和羟基基团,导致光催化剂表面带负电荷,从而有利于阳离子的MB的静电吸附.为了进一步验证该吸附机理,我们选择了另外两种染料分子,阳离子的罗丹明B和阴离子的甲基橙.结果显示,该光催化剂对罗丹明B同样具有较强的吸附能力和较好的光催化降解活性,但对甲基橙几乎没有吸附和光催化性能.这充分说明亚甲基蓝染料通过静电相互作用的形式吸附于催化剂表面,较好的吸附性能进一步促进了光催化剂的降解活性.为了讨论光催化机理,向反应体系中加入不同的捕获剂来研究光催化反应过程中产生的活性物种.研究显示,羟基自由基在光催化降解亚甲基蓝的反应中几乎没有作用,光生空穴发挥了次要作用,而超氧自由基在整个反应中发挥了主导作用.因此,光催化降解的机理如下:CaFe_2O_4在可见光激发下产生光生电子和空穴,电子快速转移到C材料的表面并与空气中的氧气反应生成超氧自由基,后者再与吸附在光催化剂表面的染料分子反应产生低毒或无毒的降解产物.此外。

气固鼓泡床结构双流体模型及其模拟验证

气固鼓泡流化床因具有较好的传热传质特性已被广泛应用于工业生产,而气泡这类非均匀结构普遍存在于流化床中,它显著影响流化床内动量、能量和质量传递以及化学反应过程。合理描述非均匀结构与三传一反的定量关系对提高连续介质模型模拟的准确性至关重要。结构双流体模型在控制方程及本构关系方面均考虑气固系统内非均匀特性的影响,是一种逻辑自洽、完备地考虑了介尺度结构的全新连续介质模型;本研究拓展了结构双流体模型应用于鼓泡流化床的数值模拟,在构造控制方程时将系统划分成颗粒主导的乳化相和气体主导的气泡相这两类相互渗透的连续流体,同时构造本构关系时涉及的气泡直径、乳化相固含率及黏度等均考虑非均匀结构影响。模拟结果表明,结构双流体模型可成功预测鼓泡床系统内的气固流动特性,同时确定气泡直径影响稀/密相相间相互作用,对模拟结果影响显著。

Chinese Expert Consensus on Microvascular Protection Strategy During Emergency Percutaneous Coronary Intervention Therapy in Patients With ST-elevation Myocardial Infarction

Microcirculatory dysfunction(CMD)typically occurs in patients with acute ST-segment elevation myocardial infarction during percutaneous coronary intervention,which is associated with more severe myocardial injury and a worse prognosis.With the advancement of intracoronary physiology and imaging technology,the prevention and therapeutic interventions of CMD have attracted more attention.However,relevant guidelines or consensus on CMD are lacking in China.The current consensus summarizes the prevention and diagnostic strategies of emergency percutaneous coronary intervention-related CMD and gives suggestions to improve the prognosis of ST-segment elevation myocardial infarction patients based on evidence from recent clinical studies,guidelines,and consensus from international sources.

MYBPC3和RYR2双基因突变致肥厚型心肌病合并室性心动过速1例

肥厚型心肌病(HCM)是一种常见的遗传性心肌病,临床表现差异较大,多数无临床症状,部分以心原性猝死为首发表现。该文报道1例家族性HCM合并室性心动过速的老年患者,基因测序发现该患者携带HCM4型的明确致病突变MYBPC3基因c.1504C>T杂合错义变异,以及可能与致心律失常右心室发育不良相关的RYR2基因c.6298C>T杂合错义变异,探讨了其临床特征及鉴别诊断,强调了HCM早期筛查、早期诊断、规范治疗的重要性。

Liquidity of China’s government bond market: Measures and driving forces

We construct a daily liquidity index of China’s government bond market using transaction data from the national interbank market during 2001–2020.The index is a composite of popular price-based and quantity-based metrics of liquidity.The composite indices,ob-tained by averaging across different metrics and by applying the principal component analysis,respectively,both point to a better liquidity condition after 2010.Market liquidity swings appear to be highly correlated with domestic funding liquidity and financial mar-ket volatility,but display fewer correlations with global macrofinan-cial indicators.Our findings suggest that the further deepening of the government bond market would support domestic financial stability and monetary operations down the road.

Development and Application of a Regional Land Subsidence Model for the Plain of Tianjin

In this paper, a coupled numerical groundwater and land subsidence model was developed for the Tianjin Plain. The model was employed to investigate the groundwater resources and their changes over the last decade, and to further predict the changing patterns of the groundwater level and associated land subsidence in future. First, according to the regional hydrogeology, the simulation area was defined with an area of 10.6×103 km2, which was divided into six aquifer units. A coupled groundwater and land subsidence numerical model was built by using Modflow2005 and the land subsidence simulation module SUB（subsidence and aquifer-system compaction）, in which the groundwater flow was modeled as three-dimensional unsteady flow and the land subsidence simulation was based on one-dimensional consolidation theory. The model was then calibrated by using the groundwater level contour lines, hydrographs, and land subsidence hydrographs over the period of 1998–2008. In addition, groundwater balance analysis of the simulation period indicated that under multi-year groundwater withdrawal condition the cross-flow recharge, compression release, and lateral boundary inflow contributed 44.43%, 32.14%, and 21.88% to the deep aquifer recharge, respectively. Finally, the model was applied to predict the changing patterns of the groundwater levels and the associated variations in land subsidence under the control of groundwater exploitation after implementation of the south-to-north water diversion project. The simulation results demonstrated that the groundwater level may gradually increase year by year with an decrease in the groundwater withdrawal; and the land in dominated land subsidence regions including the urban area, Dagang, Hangu, Jinghai, Wuqing, and Jinnan, may rebound at an average rate of 2–3 mm/a, and the land subsidence rate in the other regions may decrease.

Fabrication and characterization of microfibrillated cellulose and collagen composite films

Microfibrillated cellulose(MFC)-collagen composite films were prepared with a dispersion of acid swollen collagen fibers and carboxylated MFC at different ratios in an alkaline homogenous system.The surface topographic results obtained from SEM analyses indicated that the MFC entangled uniformly with collagen in the film and formed a closely interwoven network to reinforce the film structure.However,the MFC addition decreased the smoothness and light transparency of the films due to the aggregation of MFC.Compared to the film prepared with pure collagen,the hybrid composite film showed a higher strength and Young’s modulus but lower elongation.The swelling of the composite film in water increased with the increase of the MFC ratio in the film matrix.DSC and TG analyses demonstrated that adding MFC to collagen benefited the thermal stability of the films,due to the conformational and crystal changes in the MFC/collagen structure indicated by the FT-IR and XRD results.The MFC/collagen composite film can potentially be used as an edible material in the food and packaging industry,in particular for meat products.

Osteopontin targeted theranostic nanoprobes for laser-induced synergistic regression of vulnerable atherosclerotic plaques

Vulnerable atherosclerotic plaque(VASPs)is the major pathological cause of acute cardiovascular event.Early detection and precise intervention of VASP hold great clinical significance,yet remain a major challenge.Photodynamic therapy(PDT)realizes potent ablation efficacy under precise manipulation of laser irradiation.In this study,we constructed theranostic nanoprobes(NPs),which could precisely regress VASPs through a cascade of synergistic events triggered by local irradiation of lasers under the guidance of fluorescence/MR imaging.The NPs were formulated from human serum albumin(HSA)conjugated with a high affinity-peptide targeting osteopontin(OPN)and encapsulated with photosensitizer IR780 and hypoxia-activatable tirapazamine(TPZ).After intravenous injection into atherosclerotic mice,the OPN-targeted NPs demonstrated high specific accumulation in VASPs due to the overexpression of OPN in activated foamy macrophages in the carotid artery.Under the visible guidance of fluorescence and MR dual-model imaging,the precise near-infrared(NIR)laser irradiation generated massive reactive oxygen species(ROS),which resulted in efficient plaque ablation and amplified hypoxia within VASPs.In response to the elevated hypoxia,the initially inactive TPZ was successively boosted to present potent biological suppression of foamy macrophages.After therapeutic administration of the NPs for 2 weeks,the plaque area and the degree of carotid artery stenosis were markedly reduced.Furthermore,the formulated NPs displayed excellent biocompatibility.In conclusion,the developed HSA-based NPs demonstrated appreciable specific identification ability of VASPs and realized precise synergistic regression of atherosclerosis.

Novel Hemorrhagic Risk Score in Elderly Patients with Coronary Artery Disease and Gastrointestinal Malignant Tumor Comorbidity:A 10-year Clinical Inpatient Data Analysis from 2 Medical Centers

Objective:Older patients with comorbidity,such as coronary heart disease(CHD)and malignant gastrointestinal tumors,are at a high risk of bleeding events.However,risk prediction models based on risk factor assessment remain unclear.This study aimed to establish an individualized bleeding risk assessment system based on the analysis of 10-year inpatient clinical big data.Methods:Total clinical data of 56,819 patients with CHD and 25,988 patients with malignant digestive tract tumors(admitted from January 2008 to December 2017)were retrospectively collected at the First and Second Medical Centers of Chinese People's Liberation Army General Hospital.Among them,1307 patients with CHD and malignant digestive tract tumors were screened as the derivation cohort.The dependent variable was the occurrence of major clinical bleeding events.Baseline statistics and hypothesis tests of differences were performed for independent variables according to the occurrence of bleeding.Decision Tree,eXtreme Gradient Boosting(XGBoost),logistic regression,and random forest models were used for comparison.The accuracy,sensitivity,specificity,and area under the receiver operating characteristic curve(AUC-ROC)were applied as the criteria for evaluating and verifying model performance.To evaluate this developed model,another cohort comprising 454 patients(admitted from January 2018 to December 2019)was prospectively enrolled as the validation cohort based on the same inclusion and exclusion criteria.Results:Among the 64 variables with<50%missing values,the recursive feature elimination method with a random forest model was used to screen the selected variables.The highest accuracy was obtained following the selection of 10 scalars,and the final model was constructed accordingly.XGBoost demonstrated the best performance comprehensively.The AUC-ROC of this model was 0.981,with an accuracy,sensitivity,and specificity of 0.939,0.950,and 0.927,respectively.In the validation cohort,the AUC-ROC,accuracy,sensitivity,and specificity of the XGBoost model were 0.702,0.718,0.636,and 0.725,respectively.The rate of major bleeding events has a positive correlation with the bleeding risk score quintiles.To allow for convenient clinical application,a smartphone application was developed for easy access and calculation(http://fir.master-wx.com/sghr).Conclusion:We successfully established a risk model and score for predicting bleeding events in older patients with comorbidity,such as CHD and gastrointestinal cancer.