Dynamic Modeling Framework of Sediment Trapped by Check-Dam Networks:A Case Study of a Typical Watershed on the Chinese Loess Plateau

Check-dam construction is an effective and widely used method for sediment trapping in the Yellow River Basin and other places over the world that are prone to severe soil erosion.Quantitative estimations of the dynamic sediment trapped by check dams are necessary for evaluating the effects of check dams and planning the construction of new ones.In this study,we propose a new framework,named soil and water assessment tool(SWAT)–dynamic check dam(DCDam),for modeling the sediment trapped by check dams dynamically,by integrating the widely utilized SWAT model and a newly developed module called DCDam.We then applied this framework to a typical loess watershed,the Yan River Basin,to assess the time-varying effects of check-dam networks over the past 60 years(1957–2016).The DCDam module generated a specific check-dam network to conceptualize the complex connections at each time step(monthly).In addition,the streamflow and sediment load simulated by using the SWAT model were employed to force the sediment routing in the check-dam network.The evaluation results revealed that the SWAT-DCDam framework performed satisfactorily,with an overestimation of 11.50%,in simulating sediment trapped by check dams,when compared with a field survey of the accumulated sediment deposition.For the Yan River Basin,our results indicated that the designed structural parameters of check dams have evolved over the past 60 years,with higher dams(37.14%and 9.22%increase for large dams and medium dams,respectively)but smaller controlled areas(46.03%and 10.56%decrease for large dams and medium dams,respectively)in recent years.Sediment retained by check dams contributed to approximately 15.00%of the total sediment load reduction in the Yan River during 1970–2016.Thus,our developed framework can be a promising tool for evaluating check-dam effects,and this study can provide valuable information and support to decision-making for soil and water conservation and check-dam planning and management.

Water Stability Improvement of Acid Fine Aggregate-Based Asphalt Concrete

In general,acid aggregates are not used in combination with asphalt concrete because of their poor compatibility with the asphalt binder,which typically results in a scarce water stability of the concrete.In the present study,the feasibility of a new approach based on the combination of acid granite fine aggregate with alkaline limestone coarse aggregate and Portland cement filler has been assessed.The mineral and chemical compositions of these three materials have first been analyzed and compared.Then,the effect of different amounts of Portland cement(0%,25%,50%,75%and 100%of the total filler by weight)on the mechanical performance and water stability of the asphalt concrete has been considered.Asphalt concrete has been designed by using the Marshall method,and the mechanical performance indexes of this material,including the Marshall stability and indirect tensile strength(ITS),have been measured together with the related water stability indexes(namely the Marshall stability(RMS)and tensile strength ratio(TSR)).The results indicate that the alkaline limestone coarse aggregate and Portland cement filler can balance the drawback caused by the acid granite fine aggregate.The asphalt concrete has good mechanical performances and water stability when the amount of common limestone powder filler replaced by cement is not less than 75%.

Can the Grain-for-Green Program Really Ensure a Low Sediment Load on the Chinese Loess Plateau?

The Chinese Loess Plateau is the most seriously eroded area in the world and contributes the vast majority of the sediment that goes into the Yellow River.Since the 1950s,progressive soil and water conservation measures have been implemented—in particular,large-scale ecological restoration has been ongoing since 1999—resulting in a significant reduction of the sediment load.However,the mechanism of the sediment transport dynamics is not fully understood due to multiple and complicated influencing factors including climate change and human activities(e.g.,ecological restoration).A challenging question,then,arises:Is the current low sediment level a“new normal”in this era and in the future?To address this question,we selected a typical loess hilly region where considerable ecological restoration has been implemented,and which is regarded as the site of the first and most representative Grainfor-Green program in the Loess Plateau.We investigated the evolution of discharge–sediment relationships in the past decades(1960–2010)and their association with the soil and water conservation measures in this area.The results showed that there was a distinct change in the regression parameters of the commonly used annual discharge–sediment regression equation—a continuously increasing trend of parameter b and a decreasing trend of parameter a,accompanying the ecological restoration.The increase in exponent b(i.e.,a steeper slope)implies a potential lower sediment load resulting from low discharge and a potential higher sediment load resulting from large discharge.This finding may question the new normal of a low sediment level and implies the potential risk of a large sediment load during extremely wet years.

Application of TCM constitution in lifetime health maintenance

Healthy full life cycle has become an important national strategy,which indicates that attention needs to be given to human health throughout the life course.The full life cycle includes the whole process of conception and birth,development,growth,aging,and death,which has been recorded in Yellow Emperor's Canon of Medicine.From the perspective of traditional Chinese medicine (TCM) constitution theory,the TCM constitution focuses on the life process in a continuous evolution based on individual development at different phases or stages from infancy to senility.The development of TCM constitution is beneficial in accumulating the theoretical and practical experience for promoting the application of TCM constitution health service into the full life cycle,and providing theory,technique and method for TCM health service in the full life cycle,as well.Through this review,we've found that TCM constitution has being widely used for clinical practice,but still needs further improvement.

超选择栓塞治疗急性肾出血及CT血管成像在显示责任血管中的作用

目的研究超选择肾动脉栓塞(renal artery embolization,RAE)治疗急性肾出血的成功率,以及栓塞前CT血管成像(computed tomography an giography,CTA)在显示责任血管中的作用。方法选择2016年1月至2021年12月苏州大学附属第一医院介入科和苏州市相城人民医院介入科完成的RAE病例。以发现并栓塞责任血管、出血停止、血压恢复为技术成功,以康复出院为临床成功,以RAE前后肌酐、尿素氮、肾小球滤过率的变化,以及栓塞相关并发症评价安全性。进一步筛选,病因为创伤或医源性损、有确切出血征象、有术前增强CT的病例。将增强CT数据回传工作站,行最大密度投影(maximal intensity projection,MIP)、曲面重建(curved planar reformation,CPR)、容积再现(volume rendering,VR)重建。以RAE术中造影为金标准,研究CTA的灵敏度和特异度。结果共纳入52例,首次技术成功率90.4%,补救技术成功率96.2%,临床成功率92.3%。临床成功的48例患者中,RAE前后血清肌酐、尿素氮、肾小球滤过率差异无统计学意义,均在正常值范围内。随访期间无RAE相关并发症。共16例完成CTA重建。MIP、VR、CPR的灵敏度分别为68.8%、62.5%、68.8%。综合3种重建方法,CTA总的灵敏度为75.0%,特异度均为100%。结论我中心超选择RAE治疗急性肾出血的技术成功率为96.2%。对于创伤或医源性损伤所致的急性肾出血,栓塞前CTA可显示出血责任血管,联合多种重建方法效果更好。

Regulation of aerobic glycolysis to decelerate tumor proliferation by small molecule inhibitors targeting glucose transporters

Dear Editor,Different from normal differentiated cells,metabolic reprogramming was spotted in cancer cells,due to increased demand for energy and macromolecule synthesis during their rapid proliferation(Hanahan and Weinberg,2011;Pavlova and Thompson,2016).Most cancer cells prefer anaerobic glycolysis even with oxygen in the environment due to its higher speed to produce macromolecular materials required for biosynthesis(Vander Heiden et al.,2009;DeBerardinis and Chandel,2016).But to compensate for the lower efficiency of anaerobic glycolysis in producing ATP,these cancer cells demand much higher glucose supply(Warburg,1956;Vander Heiden et al.,2009).These metabolic characteristics point to the huge demand of cancer cells for carbohydrate substrates,which creates the possibility of treating tumors by exploiting this feature(Patra et al.,2013;DeBerardinis and Chandel,2016).

3D electronic and photonic structures as active biological interfaces

Biocompatible materials and structures with three-dimensional(3D)architectures establish an ideal platform for the integration of living cells and tissues,serving as desirable interfaces between biotic and abiotic systems.While conventional 3D bioscaffolds provide a mechanical support for biomatters,emerging developments of micro-,nano-,and mesoscale electronic and photonic devices offer new paradigms in analyzing and interrogating biosystems.In this review,we summarize recent advances in the development of 3D functional biointerfaces,with a particular focus on electrically and optically active materials,devices,and structures.We first give an overview of representative methods for manufacturing 3D biointegrated structures,such as chemical synthesis,microfabrication,mechanical assembly,and 3D printing.Subsequently,exemplary 3D nano-,micro-,and mesostructures based on various materials,including semiconductors,metals,and polymers are presented.Finally,we highlight the latest progress on versatile applications of such active 3D structures in the biomedical field,like cell culturing,biosignal sensing/modulation,and tissue regeneration.We believe future 3D micro-,nano-,and mesostructures that incorporate electrical and/or optical functionalities will not only profoundly advance the fundamental studies in biological sciences,but also create enormous opportunities for medical diagnostics and therapies.