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Cell-free expression systems have drawn increasing attention as a tool to achieve complex biological functions outside of the cell. Several applications of the technology involve the delivery of functionality to challenging environments, such as field-forward diagnostics or point-of-need manufacturing of pharmaceuticals. To achieve these goals, cell-free reaction components are preserved using encapsulation or lyophilization methods, both of which often involve an embedding of components in porous matrices like paper or hydrogels. Previous work has shown a range of impacts of porous materials on cell-free expression reactions. Here, we explored a panel of 32 paperlike materials and 5 hydrogel materials for the impact on reaction performance. The screen included a tolerance to lyophilization for reaction systems based on both cell lysates and purified expression components. For paperlike materials, we found that (1) materials based on synthetic polymers were mostly incompatible with cell-free expression, (2) lysate-based reactions were largely insensitive to the matrix for cellulosic and microfiber materials, and (3) purified systems had an improved performance when lyophilized in cellulosic but not microfiber matrices. The impact of hydrogel materials ranged from completely inhibitory to a slight enhancement. The exploration of modulating the rehydration volume of lyophilized reactions yielded reaction speed increases using an enzymatic colorimetric reporter of up to twofold with an optimal ratio of 2:1 lyophilized reaction to rehydration volume for the lysate system and 1.5:1 for the purified system. The effect was independent of the matrices assessed. Testing with a fluorescent nonenzymatic reporter and no matrix showed similar improvements in both yields and reaction speeds for the lysate system and yields but not reaction speeds for the purified system. We finally used these observations to show an improved performance of two sensors that span reaction types, matrix, and reporters. In total, these results should enhance efforts to develop field-forward applications of cell-free expression systems.

The identification of paper composition, pH, early signs of paper degradation, and emitting volatile organic compounds (VOCs) are mandatory for effective preventive conservation of paper/books. Sampling restrictions in the analysis of cultural heritage materials limit the choice of appropriate analytical methods. Solvent-free analytical techniques with nondestructive sampling are needed. Addressing this challenge, an electronic nose based on six-coated piezoelectric quartz crystals was assembled and used to analyze VOCs emitted from books. Careful selection of sensor coatings and cluster analysis allowed us to achieve a clear distinction between cotton/linen rag and wood pulp paper, and among the letter group, the discrimination between papers manufactured from alkaline and acidic stocks. This six-element sensor array was therefore able to replace destructive tests as the ones ordinarily used for paper pH measurements. The same electronic nose was able to separate aged pale-yellow paper, a visible initial sign of paper degradation, from well-preserved still white papers, even when made from the same raw material. One of the used sensors detected furfural, often seen as a marker of cellulose degradation, at lower levels than the detection limit found in the literature with gas chromatography-mass spectrometry, a much more complex bulky and expensive instrument.

International audience; Electron paramagnetic resonance (EPR), also known as electron spin resonance (ESR), is more and more used in archaeology, and types of materials analyzed or purposes expand each year. Among its applications, dating is one of the most important. Many materials containing quartz or carbonates could be dated, from sediments to tephras including heated lithic artifacts and potteries, but also teeth, speleothems, shells, corals, and even mortars or plasters. The thermal history is also an important information which can be obtained by EPR to understand ancient ways of using fire for cooking or for lithic or ceramic industry. A third application is the determination of the soil or water source, which could help to understand whence original matter used for lithic or ceramic industry came or to describe climatic environment of settlements. Archaeological artifacts can also be studied, leading to the knowledge of ancient pigments and techniques used in glasses, oil paintings, or inks. Ideas of aging status or processes can be obtained for organic materials such as paper, wood, or leather. Finally, other alternative EPR experiments, such as other frequencies than X-band, EPR microscopy, and pulsed EPR, will be described. In several archaeological research domains, EPR has been, only recently, frequently used, and a lot of effort is spent to increase reliability of the results, especially in EPR dating of the earliest or oldest samples, but also in thermal history, and tendencies to try to normalize procedures for better accuracies and easier comparisons are observed.

This paper reviews recent studies by the authors on the surface characterization of biomedically significant materials through electroosmosis determination. The surfaces studied include transparent and nontransparent materials such as quartz, ceramics, paper, and cast polymer capillaries, slides, and particles, in both native and surface modified form. The method is nondestructive, relatively fast, mechanistically simple, automatable to varying degrees, and can be used to analyze samples under physiologically compatible conditions. New experimental and mathematical modeling approaches allow estimates to be obtained with regard to the surface density and pK of various chemical groups, as well as the thickness of polymer or other surface coatings. Surface modifications which may be characterized include, covalent alteration via radiofrequency plasma discharge or organosilane grafting, noncovalent alteration via polymer adsorption, and covalent grafting of neutral polymers, such as poly(ethylene glycol) or dextran. Results complement those from other surface analysis techniques, and correlate with physiologically significant phenomena such as protein adsorption.

A new method for zinc pre-concentration/separation and determination by molecular fluorescence is proposed. The metal was complexed with o-phenanthroline and eosin at pH 7.5 in Tris; a piece of filter paper was used as a solid support and solid fluorescent emission measured using a conventional quartz cuvette. Under optimal conditions, the limits of detection and quantification were 0.36 x 10-3 and 1.29 x 10-3 µg L−1, respectively, and the linear range from 1.29 x 10-3 to 4.50 µg L−1. This method showed good sensitivity and selectivity, and it was applied to the determination of zinc in foods and tap water. The absence of filtration reduced the consumption of water and electricity. Additionally, the use of common filter papers makes it a simpler and more rapid alternative to conventional methods, with sensitivity and accuracy similar to atomic spectroscopies using a typical laboratory instrument. Fil: Talio, María Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Química de San Luis; Argentina Fil: Acosta, Maria Gimena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Química de San Luis; Argentina Fil: Acosta, Mariano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Química de San Luis; Argentina Fil: Olsina, Roberto Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Química de San Luis; Argentina. Universidad Nacional de San Luis. Facultad de Quimica, Bioquimica y Farmacia. Departamento de Quimica. Area de Quimica Analitica; Argentina Fil: Fernandez, Liliana Patricia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Química de San Luis; Argentina. Universidad Nacional de San Luis. Facultad de Quimica, Bioquimica y Farmacia. Departamento de Quimica. Area de Quimica Analitica; Argentina

The usefulness of microwave muffle furnaces for increasing the efficiency of sulfated ash determination through automation was investigated. Substances critical in their behavior were selected as model substances for this purpose: megestrol acetate and a phthalazine derivative as substances with high foaming indices and azelaic acid as a substance with a high spatter index. The selection of an optimal temperature sequence in conjunction with quartz crucibles and/or with a spatter guard made of quartz filter paper made it possible to handle even these critical substances. The analysis results were comparable and reproducible in terms of classical pharmacopeia methodology.