用于治疗诊断学的手性无机纳米材料

无机手性纳米材料因其优越的手性光学活性和物理性能而被广泛关注,其中贵金属和半导体等手性材料的制备取得了重大进展。本文介绍了几种具有良好生物相容性和低细胞毒性的手性纳米材料,并重点介绍了它们的合成方法以及手性光学特性。此外,我们总结了手性纳米材料在一些常见疾病的诊断和治疗中的应用,如阿尔茨海默症(AD)、帕金森症(PD)、糖尿病甚至癌症等,无机手性的引入将为诊断和治疗这些疾病提供一种新的策略。

Health Monitoring of Long-Haul Fiber Communication System Using Chaotic OTDR

A novel chaotic optical time-domain reflectometry(OTDR)-based approach was proposed for monitoring long-haul fiber communication systems with multiple fiber segments. The self-phase modulation and group velocity dispersion effects of the optical cable was considered in demonstrating the proof-of-concept experiment and simulation. In experiments, the correlation peaks are clearly obtained from the correlation trace between the reference and reflected(or scattered) light signals propagating in three optical-fiber segments. The technique affords a high spatial resolution of 2 m, and further long-haul fiber simulations indicate that the sensing distance can be more than 3300 km. Thus, the new proposed technique can be effectively applied for health monitoring of long-haul fiber communication systems.

Chaos Raman distributed optical fiber sensing

The physics principle of pulse flight positioning is the main theoretical bottleneck that restricts the spatial resolution of the existing Raman distributed optical fiber sensing scheme.Owing to the pulse width of tens of nanoseconds,the spatial resolution of the existing Raman distributed optical fiber sensing scheme with kilometer-level sensing distance is limited to the meter level,which seriously restricts the development of the optical time-domain reflection system.In this paper,a chaos laser is proposed in the context of the physical principle of the Raman scattering effect,and a novel theory of chaos Raman distributed optical fiber sensing scheme is presented.The scheme reveals the characteristics of chaos Raman scattering light excited by a chaotic signal on the sensing fiber.Further,the chaos time-domain compression demodulation mechanism between the temperature variation information and chaos correlation peak is demonstrated.Then,the position of the temperature variation signal is precisely located using the delay time of the chaos correlation peak combined with the chaos pulse flight time.Based on this novel optical sensing mechanism,an experiment with 10 cm spatial resolution and 1.4 km sensing distance was conducted,and the spatial resolution was found to be independent of the sensing distance.Within the limit of the existing spatial resolution theory,the spatial resolution of the proposed scheme is 50 times higher than that of the traditional scheme.The scheme also provides a new research direction for optical chaos and optical fiber sensing.

Performance Improvement of Raman Distributed Temperature System by Using Noise Suppression

在拉曼散布了温度系统，为表演改进的关键因素是噪音抑制，它严重影响察觉到的距离和温度精确性。因此，我们建议并且试验性地示威动态噪音差别算法和小浪变换模量最大值(WTMM ) 到降噪拉曼反 -- 司烧信号。察觉到的距离能从 3 km 增加到 11.5 km 和温度精确性的试验性的结果表演增加到 1.58 ? 臨? 臨?

Performance improvement in double-ended RDTS by suppressing the local external physics perturbation and intermodal dispersion

We propose and experimentally demonstrate a novel Raman-based distributed fiber-optics temperature sensor(RDTS) for improving the temperature measurement accuracy and engineering applicability.The proposed method is based on double-ended demodulation with a reference temperature and dynamic dispersion difference compensation method, which can suppress the effect of local external physics perturbation and intermodal dispersion on temperature demodulation results.Moreover, the system can omit the pre-calibration process by using the reference temperature before the temperature measurement.The experimental results of dispersion compensation indicate that the temperature accuracy optimizes from 5.6℃ to 1.2℃, and the temperature uncertainty decreases from 16.8℃ to 2.4℃.Moreover, the double-ended configuration can automatically compensate the local external physics perturbation of the sensing fiber, which exhibits a distinctive improvement.

微生物修复返溶铬污染场地的研究进展

目前,我国历史遗留铬渣堆场多数采用湿法解毒工艺进行处理,但大量化学药剂的添加不仅增加了成本,引入了污染物,而且随时间的延长铬渣中的Cr(Ⅵ)源源不断的返溶,场地出现返黄现象,形成二次污染。为了持久稳定的修复铬渣,研究人员提出用微生物修复技术处理湿法解毒后铬渣中Cr(Ⅵ)的返溶。文中综述了国内外微生物修复铬渣污染场地的研究进展,首先简述了铬渣的危害、处理现状及传统的铬污染修复技术,并以湿法解毒铬污染为例,重点揭示了处理后铬渣中Cr(Ⅵ)的返溶机理,由此可知湿法解毒后的二次污染不可避免。随后详述了微生物修复Cr(Ⅵ)过程中生物还原、生物吸附和生物矿化三大作用机理,并阐述了铬污染场地修复过程中微生物物种的响应及群落结构的演替,最后,总结了微生物修复铬渣的研究进展并展望了未来的研究方向。

Physics and applications of Raman distributed optical fiber sensing

Raman distributed optical fiber sensing has been demonstrated to be a mature and versatile scheme that presents great flexibility and effectivity for the distributed temperature measurement of a wide range of engineering applications over other established techniques.The past decades have witnessed its rapid development and extensive applicability ranging from scientific researches to industrial manufacturing.However,there are four theoretical or technical bottlenecks in traditional Raman distributed optical fiber sensing:(ⅰ)The difference in the Raman optical attenuation,a low signal-to-noise ratio(SNR)of the system and the fixed error of the Raman demodulation equation restrict the temperature measurement accuracy of the system.{ⅱ)The sensing distance and spatial resolution cannot be reconciled.(ⅲ)There is a contradiction between the SNR and measurement time of the system.(ⅳ)Raman distributed optical fiber sensing cannot perform dual-parameter detection.Based on the above theoretical and technical bottlenecks,advances in performance enhancements and typical applications of Raman distributed optical fiber sensing are reviewed in this paper.Integration of this optical system technology with knowledge based,that is,demodulation technology etc.can further the performance and accuracy of these systems.

Proteomic and molecular investigations revealed that Acidithiobacillus caldus adopts multiple strategies for adaptation to NaCl stress

Acidithiobacillus caldus plays an important role in commercial bioleaching.To understand how NaCl stress adaptation occurs in A.caldus,we grew A.caldus strain SM-1 in media containing high NaCl concentrations.SM-1 grew at concentrations of up to 1.0-mol L^(-1)NaCl,but growth was severely inhibited at higher concentrations.Proteomic analysis showed that SM-1 used multiple strategies to respond to NaCl stress.In addition to several heatshock proteins,enzymes involved in proline biosynthesis increased under NaCl stress.In addition,two DNA-binding proteins and a third protein of unknown function(Atc_(1291)),which was subsequently identified as a putative single-stranded DNA-binding protein,were up-regulated in the presence of NaCl stress.These DNA-binding proteins might play a role in response to osmotic stress.Atc_(1291)was cloned and expressed in Escherichia coli.Surprisingly,we found that E.coli BL21/pET28a-atc_(1291)grew to higher cell densities than E.coli BL21/pET28a,regardless of NaCI stress.Homologs to Atc_(1291)were identified in several groups of Proleohacleria.The role of Atc_(1291)in enhancing cell growth needs further investigation.

Slope-assisted Raman distributed optical fiber sensing

Raman distributed optical fiber sensing is required to achieve accurate temperature measurements in a micro-scale area.In this study,we first analyze and demonstrate the pulse transmission feature in the temperature variation area and the superposition characteristics of Raman optical time-domain reflectometry(OTDR)signals by numerical simulation.The equations of superimposed Raman anti-Stokes scattered signals at different stages are presented,providing a theoretical basis for the positioning and physical quantity demodulation of whole optical fiber systems based on the OTDR principle.Moreover,we propose and experimentally demonstrate a slope-assisted sensing principle and scheme in a Raman distributed optical fiber system.To the best our knowledge,this is the first experimental demonstration of Raman distributed optical fiber sensing in a centimeter-level spatial measurement region.

Simultaneous Strain and Temperature Measurement Based on Chaotic Brillouin Optical Correlation-Domain Analysis in Large-Effective-Area Fibers

Chaotic Brillouin optical correlation domain analysis(BOCDA)has been proposed and experimentally demonstrated with the advantage of high spatial resolution.However,it faces the same issue of the temperature and strain cross-sensitivity.In this paper,the simultaneous measurement of temperature and strain can be preliminarily achieved by analyzing the two Brillouin frequencies of the chaotic laser in a large-effective-area fiber(LEAF).A temperature resolution of 1℃ and a strain resolution of 20μξ can be obtained with a spatial resolution of 3.9cm.The actual temperature and strain measurement errors are 0.37℃ and 10μξ,respectively,which are within the maximum measurement errors.

Bioactive citrate-based polyurethane tissue adhesive for fast sealing and promoted wound healing

As a superior alternative to sutures,tissue adhesives have been developed significantly in recent years.However,existing tissue adhesives struggle to form fast and stable adhesion between tissue interfaces,bond weakly in wet environments and lack bioactivity.In this study,a degradable and bioactive citrate-based polyurethane adhesive is constructed to achieve rapid and strong tissue adhesion.The hydrophobic layer was created with polycaprolactone to overcome the bonding failure between tissue and adhesion layer in wet environments,which can effectively improve the wet bonding strength.This citrate-based polyurethane adhesive provides rapid,non-invasive,liquid-tight and seamless closure of skin incisions,overcoming the limitations of sutures and commercial tissue adhesives.In addition,it exhibits biocompatibility,biodegradability and hemostatic properties.The degradation product citrate could promote the process of angiogenesis and accelerate wound healing.This study provides a novel approach to the development of a fast-adhering wet tissue adhesive and provides a valuable contribution to the development of polyurethane-based tissue adhesives.