中医治未病领域中免疫组库(TCR/BCR)作为一种新型“全息”生物标志物的应用与展望

中医“治未病”理论构成了中医药健康管理的主要内容,“治未病”思想为中医药健康管理体系赋予科学内涵,中医药健康管理体系也是“治未病”思想的外在体现,该体系的建立与完善离不开中医“治未病”思想的深度解析。“治未病”思想的深度解析需要从科学意义上深度思考三个关键问题:一是如何客观描述“未病”的生物学基础并阐明“未病”发生机制;二是如何阐释中医“治未病”科学内涵及中药复方的特殊药理效应机制;三是如何构建以中医“治未病”为内核的中医药精准健康管理新模式。本文从监管科学角度出发,首次提出“全息”生物标志物免疫组库(TCR/BCR)可作为新型“全息”生物标志物,用以客观表征中医治未病生物学基础和干预效果的科学评价体系,进而作为新的科学证据解释上述三个关键科学问题。

Optimal design of nanofiltration system for surface water treatment

Both reverse osmosis(RO) and nanofiltration(NF) membranes have been increasingly used for water purification and desalination. However, the salt rejection of NF membranes is quite different from that of RO membranes,which makes a significant distinction in their process designs. This work started from the performance investigation of a single NF membrane element and then focused on the process design of the NF system for surface water treatment. In experimental tests, it was found that the observed rejection of the NF element becomes nearly constant when the concentrate flow is large enough, while the membrane flux of the NF element is quite stable regardless of the water flow across the membrane surface. These findings can be used to instruct the process design of the NF system for surface water treatment. In process design, a two-stage arrangement is sufficient for the NF system to reach the highest water recovery, while the RO system requires a three-stage arrangement.

Analysis of Bubble Behavior in a Horizontal Rectangular Channel under Subcooled Flow Boiling Conditions

Experiments on subcooled flow boiling have been conducted using water in a rectangular flow channel.Similar to the coolant channel in internal combustion engines(IC engines),the flow channel in this experiment was asymmetrically heated.Bubble images were captured using a high speed camera from the side view of the channel.The experimental conditions in terms of bulk temperature,bulk velocity,pressure and heat flux ranged from 65°C–75°C,0.25 m/s–0.75 m/s,1–1.7 bar and 490 kW/m2–700 kW/m2,respectively.On the basis of these tests,a statistical analysis of the bubble size has been conducted considering a population of 1400 samples.It has been found that the mean Sauter bubble diameter increases with the decrease of subcooling,bulk velocity,pressure and increased heat flux.A modified correlation has been finally proposed to predict the mean Sauter bubble diameter under subcooled flow boiling conditions upstream of the onset of significant void,which shows good accuracy with the experimental results.

A Solution-Processed n-Type Conducting Polymer Without Side Chains Formed via Nonmetal-Participated Polymerization and in Situ n-Doping

Solution-processed conducting polymers(CPs)are emerging as promising multifunctional materials and are motivating the development of several electronic applications.However,there are fewer highperformance electron conduction-dominated n-type CPs than p-types.Thus,the exploration of other material designs and synthesis methods is required.Accordingly,we developed a facile metal catalystfree method by combining polymerization and in situ n-doping to produce an n-type conducting polymer,poly(benzodithiophenedione)(PBTDO).The doping procedure enabled interaction between the charged conjugated backbones and solvent,dimethyl sulfoxide,making the doped conducting polymer soluble without the assistance of side chains or surfactants.PBTDO exhibited an extremely low-lying reduction level,moderate conductivity,and good air stability with potential applications in n-type organic thermoelectric devices.Moreover,it was found that the in situ doping efficiency in the reaction was highly dependent on the energy level and backbone planarity.Doping cannot occur for polymers with a high lowest unoccupied molecular orbital level and distorted conjugated chains prevent a high doping efficiency from being obtained.This study gains deeper insight into the n-doping mechanisms of conjugated polymers,with guidance for the design of highperformance n-type CPs.

激光熔覆Ni-Al/Al_(2)O_(3)-13%TiO_(2)金属陶瓷涂层的组织性能研究

为了进一步研究激光熔覆Ni-Al/Al_(2)O_(3)-13%TiO_(2)金属陶瓷涂层的硬度及耐磨性,应用YLS-2000光纤激光器在45钢基体上分别制备Ni-Al涂层及Ni-Al/Al_(2)O_(3)-13%TiO_(2)金属陶瓷涂层。通过金相显微镜、扫描电子显微镜、X射线能谱分析、X射线衍射等系统地研究涂层的组织形貌、物相组成及元素分布。采用HXD-1000TB维氏硬度仪测定涂层截面显微硬度分布,利用M-2000磨损试验机进行磨损试验。结果表明,Ni-Al/Al_(2)O_(3)-13%TiO_(2)金属陶瓷涂层的宏观成形质量较好,无裂纹,其涂层的截面最高硬度约为Ni-Al涂层的2倍,约为基体的4倍;其磨损体积约是45钢基体的1/8,相较于Ni-Al涂层的磨损体积降低了30%。Ni-Al/Al_(2)O_(3)-13%TiO_(2)金属陶瓷涂层组织更加均匀致密,其硬度及耐磨性能相较于Ni-Al涂层及基体材料显著提升,该研究对于金属陶瓷材料的整体性能分析具有一定的参考意义。

Surface modification of biomaterials by photochemical immobilization and photograft polymerization to improve hemocompatibility

Thrombus formation and blood coagulation are serious problems associated with blood contacting products,such as catheters,vascular grafts,artificial hearts,and heart valves.Recent progresses and strategies to improve the hemocompatibility of biomaterials by surface modification using photochemical immobilization and photograft polymerization are reviewed in this paper.Three approaches to modify biomaterial surfaces for improving the hemocompatibility,i.e.,bioinert surfaces,immobilization of anticoagulative substances and biomimetic surfaces,are introduced.The biomimetic amphiphilic phosphorylcholine and Arg-Gly-Asp(RGD)sequence are the most effective and most often employed biomolecules and peptide sequence for improving hemocompatibility of material surfaces.The RGD sequence can enhance adhesion and growth of endothelial cells(ECs)on material surfaces and increase the retention of ECs under flow shear stress conditions.This surface modification is a promising strategy for biomaterials especially for cardiovascular grafts and functional tissue engineered blood vessels.

Hemocompatible polyurethane/gelatin-heparin nanofibrous scaffolds formed by a bi-layer electrospinning technique as potential artificial blood vessels

In this paper,a scaffold,which mimics the morphology and mechanical properties of a native blood vessel is reported.The scaffold was prepared by sequential bi-layer electrospinning on a rotating mandrel-type collector.The tubular scaffolds(inner diameter 4 mm,length 3 cm)are composed of a polyurethane(PU)fibrous outer-layer and a gelatin-heparin fibrous inner-layer.They were fabricated by electrospinning technology,which enables control of the composition,structure,and mechanical properties of the scaffolds.The microstructure,fiber morphology and mechanical properties of the scaffolds were examined by means of scanning electron microscopy(SEM)and tensile tests.The PU/gelatinheparin tubular scaffolds have a porous structure.The scaffolds achieved a breaking strength(3.7±0.13 MPa)and an elongation at break(110±8%)that are appropriate for artificial blood vessels.When the scaffolds were immersed in water for 1 h,the breaking strength decreased slightly to 2.2±0.3 MPa,but the elongation at break increased to 145
21%.In platelet adhesion tests the gelatin-heparin fibrous scaffolds showed a significant suppression of platelet adhesion.Heparin was released from the scaffolds at a fairly uniform rate during the period of 2nd day to 9th day.The scaffolds are expected to mimic the complex matrix structure of native arteries,and to have good biocompatibility as an artificial blood vessel owing to the heparin release.

Electrospinning of polycarbonate urethane biomaterials

Polycarbonate urethane(PCU)nano-fibers were fabricated via electrospinning using N,Ndimethylformamide(DMF)and tetrahydrofuran(THF)as the mixed solvent.The effect of volume ratios of DMF and THF in the mixed solvent on the fiber structures was investigated.The results show that nano-fibers with a narrow diameter distribution and a few defects were obtained when mixed solvent with the appropriate volume ratio of DMF and THF as 1∶1.When the proportion of DMF was more than 75%in the mixed solvent,it was easy to form many beaded fibers.The applied voltage in the electrospinning process has a significant influence on the morphology of fibers.When the electric voltage was set between 22 and 32 kV,the average diameters of the fibers were found between 420 and 570 nm.Scanning electron microscopy(SEM)images showed that fiber diameter and structural morphology of the electrospun PCU membranes are a function of the polymer solution concentration.When the concentration of PCU solution was 6.0 wt-%,a beaded-fiber microstructure was obtained.With increasing the concentration of PCU solutions above 6.0 wt-%,beaded fiber decreased and finally disappeared.However,when the PCU concentration was over 14.0 wt-%,the average diameter of fibers became large,closed to 2μm,because of the high solution viscosity.The average diameter of nanofibers increased linearly with increasing the volume flow rate of the PCU solution(10.0 wt-%)when the applied voltagewas 24 kV.The results show that the morphology of PCU fibers could be controlled by electrospinning parameters,such as solution concentration,electric voltage and flow rate.

Discrete element method dynamic simulation of icosahedral particle packing under three-dimensional mechanical vibration

Packing densification of monosized regular icosahedral particles under three-dimensional mechanical vibration has been simulated by the discrete element method (DEM).The effects of the vibration conditions and container size on packing densification were systematically investigated.In addition to the macroscale properties (packing density and porosity),the microscale properties,such as the coordination number (CN),radial distribution function (RDF),particle contact type,particle orientation distribution,and stresses/forces,in random loose packing (RLP) and random close packing (RCP) were also characterized and analyzed.The results show that transformation of icosahedral particle packing from RLP to RCP can be realized by properly controlling the vibration conditions.The maximum random packing density without the wall effect reaches 0.7078.Microscale property analysis shows that the average CN increases after vibration.The RDF curves contain two clear peaks for RLP and three for RCP.From RLP to RCP,the probability of face to face contact between two particles increases,while the probabilities of edge to edge,edge to face,and face to vertex contact decrease.The orientation correlation functions indicate the randomness of the vibrated packing structure.In addition,more uniform force and stress distributions are observed within the dense packing structure.

Multistage second-order microring-resonator filters with box-like spectral responses and relaxed fabrication tolerances

We demonstrate an optical filter based on multistage second-order microring resonators（MRs） with box-like spectral responses. Compared with single-stage high-order optical filters with the same number of MRs,the demonstrated structure has comparable performances in the aspects of passband flatness, rolling-off slope and insertion loss. Moreover, the architecture relaxes the fabrication tolerance, electrical wiring and tuning difficulty since there are only two MRs in each stage. We experimentally demonstrate this kind of optical filter with five stages, which shows a 3-dB bandwidth of ~17 GHz, a rolling-off slope of ~5 dB/GHz and an on-chip insertion loss of ~6 dB.