实施ICRP建议的主要挑战:近期和未来的发展（英文）

自2007年国际放射防护委员会(ICRP)发布一般性建议以来,在解决将这些建议付诸实践所面临的挑战方面取得了一些进展。值得注意的是,为放射防护管理而提出三类照射情况后(即,计划照射、现存照射及应急照射),我们进一步研究了它们在几个领域的应用,如涉及天然放射性物质的工业领域以及核事故发生后的应急与恢复领域。本文着重介绍了最近一些出版物提出的以及持续开展的工作中所涉及的主要问题,重点围绕与放射防护体系伦理基础有关的研究进展、放射防护体系在管理现存照射情况中的应用以及环境放射防护与ICRP防护体系的融合。最后,本文介绍了2022年ICRP成立的与放射防护体系应用相关的新工作组的工作目标。     

Study of the Role of the Tyrosine Kinase Receptor MerTK in the Development of Kidney Ischemia-Reperfusion Injury in RCS Rats

Renal ischaemia reperfusion (I/R) triggers a cascade of events including oxidative stress, apoptotic body and microparticle (MP) formation as well as an acute inflammatory process that may contribute to organ failure. Macrophages are recruited to phagocytose cell debris and MPs. The tyrosine kinase receptor MerTK is a major player in the phagocytosis process. Experimental models of renal I/R events are of major importance for identifying I/R key players and for elaborating novel therapeutical approaches. A major aim of our study was to investigate possible involvement of MerTK in renal I/R. We performed our study on both natural mutant rats for MerTK (referred to as RCS) and on wild type rats referred to as WT. I/R was established by of bilateral clamping of the renal pedicles for 30′ followed by three days of reperfusion. Plasma samples were analysed for creatinine, aspartate aminotransferase (ASAT), lactate dehydrogenase (LDH), kidney injury molecule -1 (KIM-1), and neutrophil gelatinase-associated lipocalin (NGAL) levels and for MPs. Kidney tissue damage and CD68-positive cell requirement were analysed by histochemistry. monocyte chemoattractant protein-1 (MCP-1), myeloperoxidase (MPO), inducible nitric oxide synthase (iNOS), and histone 3A (H3A) levels in kidney tissue lysates were analysed by western blotting. The phagocytic activity of blood-isolated monocytes collected from RCS or WT towards annexin-V positive bodies derived from cultured renal cell was assessed by fluorescence-activated single cell sorting (FACS) and confocal microscopy analyses. The renal I/R model for RCS rat described for the first time here paves the way for further investigations of MerTK-dependent events in renal tissue injury and repair mechanisms.     

Physical mapping of chromosomes VII and XV of Saccharomyces cerevisiae at 3·5 kb average resolution to allow their complete sequencing

The high resolution complete physical maps of chromosomes VII and XV were constructed to form the basis for sequencing these chromosomes as part of the European systematic sequencing programme of the yeast genome, using a unique cosmid library from strain FY1679, and an original top-down mapping strategy involving I-Sce I chromosome fragmentation. A total of 138 and 196 cosmid clones were used to construct the maps for VII and XV, respectively, forming two unique contigs that cover the entirety of chromosomes (1091 kb each), except the telomeric repeats. Colinearity of the cosmid inserts with yeast DNA was verified, and the physical maps were eventually compared with the independently generated genetic maps. © 1998 John Wiley & Sons, Ltd.     

Flow monitoring in liquid composite molding based on linear direct current sensing technique

On‐line monitoring of the Liquid Composite Molding (LCM) process is a key element to improve part quality and to reduce manufacturing cost. In this context, direct current (DC) resistance measurement is a promising sensing technique allowing to track both flow front position and degree of curing of the resin during injection. An original measurement technique called Linear Direct Current (LDC) based on the same physical principle as DC was developed to record the flow front position continuously and not only at discrete nodes location. Preliminary measurements in a 1D‐flow channel have shown the large influence of the hardware configuration on the accuracy of the LDC system. Further experiments were conducted with the support of an embedded print plate in the flow channel as LDC sensor. These 2D measurements have demonstrated the relatively good spatial accuracy and stability of the LDC system. Permeability characterization in the 1D‐flow channel based on flow front position delivered by LDC, ultrasound monitoring techniques and visual recording is also presented in this paper. The flow front position determined by conventional methods based on video capture is taken as reference. Comparison of the permeability values (K_visual, K_LDC and K_US) shows a maximum deviation of 6.93% given by the LDC‐system. The ultrasound interface change measurement principle allows very accurate and reproducible punctual flow front tracking and shows a maximum deviation compared to the reference permeability (K_visual) of 3.32%. This study shows the potential of the investigated techniques for flow front monitoring of LCM injection processes.     

Direct extraction of the mean particle size from a digital hologram

Digital holography, which consists of both acquiring the hologram image in a digital camera and numerically reconstructing the information, offers new and faster ways to make the most of a hologram. We describe a new method to determine the rough size of particles in an in-line hologram. This method relies on a property that is specific to interference patterns in Fresnel holograms: Self-correlation of a hologram provides access to size information. The proposed method is both simple and fast and gives results with acceptable precision. It suppresses all the problems related to the numerical depth of focus when large depth volumes are analyzed.     

Single crystalline nature of para-sexiphenyl crystallites grown on KCl(100)

This work focuses on studies of the single crystal nature of para-sexiphenyl structures grown on freshly cleaved KCl(100) surfaces. Two different kinds of morphologies, namely terrace like structures and needle like structures, are found by atomic force microscopy as well as by electron microscopy. Regardless of the morphology the individual crystallites show highly regular shapes. The crystalline alignment and the degree of order of the crystallites on the surface are determined by X-ray diffraction. Several epitaxial alignments of para-sexiphenyl on KCl(100) are observed and all of them are perfectly aligned on the surface. The rocking curve widths of the organic crystallites do not exceed 800" which is approximately only the four fold of the substrates' ones. The single crystalline nature of para-sexiphenyl crystallites is proven by transmission electron microscopy, diffraction patterns, dark field imaging and high resolution techniques. Single crystalline terraced mounds reach diameters of several microns and heights of 50 nm. Single crystal needles show heights and breadths of more than 100 nm and lengths of several microns.     

Modeling iron binding to organic matter

The aim of the present work is to model iron speciation during its interaction with natural organic matter. Experimental data for iron speciation were achieved with an insolubilised humic acid used as an organic matter analogue for 30microM to 1.8 mM total iron concentrations and 2< or = pH< or = 5.5. IHA was found to be able to impose its redox potential to the solution and therefore the Fe(ll)/Fe(lll) ratio. Model VI and the NICA-Donnan model have been adjusted to experimental results of acid-base titrations, total iron measurements, and redox speciation in solution. They both describe well pH and concentration dependence of iron adsorption. For high iron concentration, Fe(lll) solution activity is limited by precipitation of a poorly ordered Fe oxyhydroxide with a higher solubility (log Ks = 5.6-5.7) than ferryhydrite described in the litterature.     

Optimization of star-oriented and layer-oriented wavefront sensing concepts for ground layer adaptive optics

Multiconjugate adaptive optics is one of the major challenges in adaptive optics. It requires the measurement of the volumic distribution of the turbulence. Two wavefront sensing (WFS) concepts have been proposed to perform the wavefront analysis for such systems: the star-oriented and layer-oriented approaches. We give a performance analysis and a comparison of these two concepts in the framework of the simplest of the multi-guide-star adaptive optics systems, that is, ground layer adaptive optics. A phase-related criterion is proposed to assess analytically the performance of both concepts. This study highlights the main advantages and drawbacks of each WFS concept and shows how it is possible to optimize the concepts with respect to the signal to noise ratio on the phase measurement. A comparison of their optimized versions is provided and shows that one can expect very similar performance with the two optimized concepts.     

Interface study on heterostructured GaP-GaAs nanowires

The interface chemical composition of heterostructured GaP-GaAs nanowire segments was studied by the use of energy-dispersive x-ray analysis. An arsenic-rich tail in the GaP segments following GaAs could be minimized by reducing the AsH(3) molar fraction and the growth rate. For the temperature regime used for vapour-liquid-solid growth, we observe the opposite trend on interface sharpness compared to high-temperature layer-by-layer growth, that is, the sharpness of the interface improves with reducing temperature.