Gamma irradiation of protein-based textiles for historical collections decontamination

In order to investigate the effect of gamma rays on cultural heritage materials, samples of silk and wool fabrics were subjected to accelerated ageing testing and then irradiated with different gamma-ray doses: 10 and 25 kGy. In the data analysis, combining thermal analysis (TG and DTG), infrared spectroscopy (FTIR-ATR) and mechanical tests allowed us to explore the changes in physical and chemical features for silk and wool, in relationship to the radiation doses. This analytical protocol offers a way to examine the behaviour of the textiles made of wool and silk within museum collections and their response to gamma-rays irradiation treatment. An exposure to a dose of 10 kGy did not cause significant changes in the tested properties; however, higher doses initiated irreversible loss in the physical and chemical stability of protein-based fabrics. Increasing the irradiation dose above 10 kGy has drastic effects in the loss of elasticity and the mechanical resistance of the tested yarns.     

Integration of functional myotubes with a Bio-MEMS device for non-invasive interrogation

We have developed a biological micro-electromechanical system (Bio-MEMS) device consisting of surface-modified microfabricated silicon cantilevers and an AFM detection apparatus for the study of cultured myotubes. With this system we are able to selectively stimulate the myotubes as well as report on a variety of physiological properties of the myotubes in real time and in a high-throughput manner. This system will serve as the foundation for future work integrating multiple tissue types for the creation of Bio-MEMS analogues of complex tissues and biological circuits.     

Calibration-Free Laser-Induced Breakdown Spectroscopy: State of the art

The aim of this paper is offering a critical review of Calibration-Free Laser-Induced Breakdown Spectroscopy (CF-LIBS), the approach of multi-elemental quantitative analysis of LIBS spectra, based on the measurement of line intensities and plasma properties (plasma electron density and temperature) and on the assumption of a Boltzmann population of excited levels, which does not require the use of calibration curves or matrix-matched standards. The first part of this review focuses on the applications of the CF-LIBS method. Quantitative results reported in the literature, obtained in the analysis of various materials and in a wide range of experimental conditions, are summarized, with a special emphasis on the departure from nominal composition values. The second part is a discussion of the simplifying assumptions which lie at the basis of the CF-LIBS algorithm (stoichiometric ablation and complete atomization, thermal equilibrium, homogeneous plasma, thin radiation, detection of all elements). The inspection of the literature suggests that the CF-LIBS method is more accurate in analyzing metallic alloys rather than dielectrics. However, the full exploitation of the method seems to be still far to come, especially for the lack of a complete characterization of the effects of experimental constraints. However, some general directions can be suggested to help the analyst in designing LIBS measurements in a way which is more suited for CF-LIBS analysis.     

Application of a portable XRF spectrometer for the non-invasive analysis of museum metal artefacts

The present paper reviews examples of the application of a portable - in house developed- XRF spectrometer for the analysis of museum metal artefacts in Greece. Specific topics are addressed, in particular, to which extent the qualitative or quantitative XRF analyses reveal important information about the raw materials and manufacture techniques used for gold, silver and bronze alloys in antiquity. The analytical information that it is gained by means of the XRF measurements is further assessed in comparison with the existing archaeometallurgical knowledge.     

Human biomonitoring of emerging pollutants through non-invasive matrices: state of the art and future potential

Human biomonitoring (HBM) is a scientific technique that allows us to assess whether and to what extent environmental pollutants enter humans. We review here the current HBM efforts for organophosphate esters, emerging flame retardants, perfluoroalkyl substances, and phthalate esters. Use of some of these chemicals has already been banned or restricted; they are regularly detected in the environment, wildlife, and human matrices. Traditionally, blood and urine collection have been widely used as sampling methods. New non-invasive approaches (e.g., saliva, hair, nails) are emerging as valid alternatives since they offer advantages with respect to sampling, handling, and ethical aspects, while ensuring similar reliability and sensitivity. Nevertheless, the identification of biomarkers of exposure is often difficult because chemicals may be metabolized in the human body. For many of the above-mentioned compounds, the mechanisms of the favorable metabolization pathways have not been unraveled, but research on important metabolites that could be used as biomarkers of exposure is growing. This review summarizes the state of the art regarding human exposure to, (non-invasive) HBM of, and metabolism of major organophosphate esters, emerging flame retardants, perfluoroalkyl substances, and phthalate esters currently detected in the environment.

Weak aggregation: State of the art,expectations and open questions

This paper gives an overview of weak aggregation due to long-range molecular forces beyond the first neighbor. Such subtle self-assemblies are an important part of modern colloidal chemistry and concern organic molecules as well as inorganic electrolytes and hybrid aggregates. Diverse aspects of such colloidal aggregations, as described in this special issue, can be characterized by the effective free energy per molecule involved. We discuss here expectations about emerging knowledge in this field and predictive modeling of inorganic as well as organic colloids and hybrid aggregates. Some still open questions are also given.     

State of the art of coherent forward scattering spectroscopy

Summary Magneto-optic rotation produced by the Faraday or the Voigt configuration has been employed to determine trace elements in an atomic vapour under the name of coherent forward scattering spectroscopy (CFS). Theoretically and experimentally, at low atomic density, the forward scattering radiation intensity is proportional to the square of the atomic density. Therefore, highly sensitive detection can be expected. However, from the opposite point of view, CFS signal drops very rapidly with the concentration near the detection limit, and CFS degrades sensitivity when it is utilized to detect atomic species at low concentration. The alleviation of this unattractive feature and that of small dynamic range were attempted by the experimental set-up of the Voigt configuration: a transverse magnetic field of 10 kOe around a graphite furnace with Rochon prisms as polarizer and analyzer. Then the analytical applications of CFS for the determination of trace elements in several metals following simple sample dissolving procedure were carried out. One of the advantage of the CFS: capability of simultaneous multielement analysis with simpler instrumentation could be ascertained using a xenon lamp as a radiation source.

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Stand der Spektroskopie durch kohärente Vorwärtsstreuung

Zusammenfassung Magneto-optische Rotation, beobachtet in Faraday- oder Voigt-Konfiguration, wurde unter dem Namen kohärente Vorwärtsstreuung (CFS) benutzt, um Spurenelemente in atomarem Dampf zu bestimmen. Bei niedrigen Atomdichten ist die vorwärtsgestreute Intensität, theoretisch und experimentell, proportional dem Quadrat der Atomzahldichte. Daher kann eine hohe Empfindlichkeit erwartet werden. Vom entgegengesetzten Standpunkt aus gesehen fällt jedoch das CFS-Signal zu Konzentrationen nahe der Nachweisgrenze hin rasch ab, was für den Nachweis von Atomen bei niedrigen Konzentrationen nachteilig ist. Es wurde versucht, diese ungünstige Eigenschaft sowie den kleinen dynamischen Bereich durch den experimentellen Aufbau der Voigt-Konfiguration zu verbessern: ein transversales Magnetfeld, in dem sich der Graphitrohrofen befindet, mit Rochon-Prismen als Polarisator und Analysator. Damit wurde die CFS für die Bestimmung von Spurenelementen in mehreren Metallen nach einfachem Lösen der Probe angewandt. Einer der Vorteile der CFS ist die Möglichkeit der simultanen Multielementanalyse mit einfacher instrumenteller Ausrüstung mit Hilfe einer Xenonlampe als Strahlungsquelle.

     

Electrochemical disinfection – State of the art and tendencies

Electrochemical disinfection has gained increasing interest in many sectors of social and industrial life. The reason is the growing need to disinfect the air, water, and special surfaces of different nature such as drinking water, wastewater, pool water, and other water qualities or surfaces. New research studies are reported and discussed. A stronger orientation on engineering aspects is intended. Following tendencies can be identified - research on complex liquid systems, implementation of risks consideration seen from by-product formation, and better cooperation between researchers and industry oriented to improve cell design and disinfection technology. Partially, reaction kinetics is studied and discussed at higher levels of likelihood. Furthermore, it can be found that more and more research papers deal with hybrid technologies to create novelty, to use synergistic effects and to meet the demands of real system treatment under practical conditions. A major focus can be identified for wastewater treatment/disinfection emphasizing electrocoagulation and electro-photocatalysis.     

混合色谱填料的研究进展

随着科学技术的发展,人们需要分离分析的样品越来越复杂,尤其是多肽、蛋白质类生物样品的复杂性使得单一模式色谱难以满足分离分析的要求。混合模式色谱因其独特的分离性能,可以在一次分离中获得与多维色谱相当的分离效果,而且可以避免多维色谱系统结构复杂、流动相兼容性差、分析时间长等问题,成为近年来的研究热点之一。混合模式色谱的研究重点是色谱固定相的设计与开发。混合模式色谱固定相包括反相/离子交换混合固定相、反相/亲水混合固定相、亲水/离子交换混合固定相、两性离子交换混合固定相及三相混合固定相。本文综述了近年来混合模式色谱填料的研究及应用进展,并对混合模式色谱及固定相的发展前景进行了展望。     

State of the art in the delivery of photosensitizers for photodynamic therapy

In photodynamic therapy, one of the problems limiting the use of many photosensitizers (PS) is the difficulty in preparing pharmaceutical formulations that enable their parenteral administration. Due to their low water solubility, the hydrophobic PS cannot be simply injected intravenously. Different strategies, including polymer-PS conjugation or encapsulation of the drug in colloidal carriers such as oil-dispersions, liposomes and polymeric particles, have been investigated. Although these colloidal carriers tend to accumulate selectively in tumour tissues, they are rapidly taken up by the mononuclear phagocytic system. In order to reduce this undesirable uptake by phagocytic cells, long-circulating carriers that consist of surface modified carriers have been developed. Moreover, considerable effort has been directed towards using other types of carriers to improve tumour targeting and to minimize the side effects. One of the approaches is to entrap PS into the lipophilic core of low-density lipoproteins (LDL) without altering their biological properties. The LDL receptor pathway is an important factor in the selective accumulation of PS in tumour tissue owing to the increased number of LDL receptors on the proliferating cell surface. Specific targeting can also be achieved by binding of monoclonal antibodies or specific tumour-seeking molecules to PS or by the coating of PS loaded carriers.     

State of the art in time-resolved laser-induced fluorescence for actinides analysis: Applications and trends

Time-resolved laser-induced fluorescence (TRLIF) is a method of choice for actinides and lanthanides determination at low level in nuclear, biological and environmental samples. This technique is based on pulsed laser excitation followed by temporal resolution of the fluorescence signal. This technique has many advantages such as: high sensitivity, rapidity, triple selectivity and is applicable in a wide range of activity concentrations. TRLIF has been used in several fields such as; geology, in the PUREX process, in the medical field, in the environments and for nuclear waste disposal applications. Trends are towards the use of TRLIF for remote determination via fiber optics and optode as well a speciation.     

State of the art in catalytic oxidation of chlorinated volatile organic compounds

Chlorine-containing organic compounds (Cl-VOC) require special attention due to their distinct toxicity, high stability and persistence in the environment. Removal of Cl-VOC by catalytic oxidation over a wide variety of catalysts has been presented in literature. This paper reviews the state of the art in this subject, including different model compounds, nature of catalysts, and oxidation activity. Catalyst selectivity (CO₂ vs. CO and HCl vs. Cl₂), by-products formation and the causes of deactivation are also analyzed as the most important factors in the catalyst selection for practical applications.