Search

Paper has the potential to dramatically reduce the cost of electronic components. In fact, paper is 10 000 times cheaper than crystalline silicon, motivating the research to integrate electronic materials on paper substrates. Among the different electronic materials, van der Waals materials are attracting the interest of the scientific community working on paper-based electronics because of the combination of high electrical performance and mechanical flexibility. Up to now, different methods have been developed to pattern conducting, semiconducting and insulating van der Waals materials on paper but the integration of superconductors remains elusive. Here, the deposition of NbSe2, an illustrative van der Waals superconductor, on standard copy paper is demonstrated. The deposited NbSe2 films on paper display superconducting properties (e.g. observation of Meissner effect and resistance drop to zero-resistance state when cooled down below its critical temperature) similar to those of bulk NbSe2., Paper has the potential to dramatically reduce the cost of electronic components but the integration of electronic materials is challenging. Here the integration of NbSe2, a van der Waals superconductor, on paper is demonstrated.

In this work, a novel paper-based analytical device (PAD) coupled to LED induced fluorescence (LIF) detection (fPAD) for the rapid, selective, and sensitivequantification of phenylalanine (Phe) in neonatal samples was developed. EnzymesPhenylalanine dehydrogenase (PheDH) and diaphorase were immobilized on a papermicrozone previously modified with zinc oxide nanoparticles (ZnONPs) coated withchitosan (CH-ZnONPs). Phe was extracted from the blood spots collected samples on filter paper and was mixed with nicotinamide adenine dinucleotide (NAD+) and resazurin. Then the mixture was deposited on the reaction microzone of the fPAD where PheDH converts the Phe and NAD+ to phenylpyruvate and NADH, respectively.Finally, NADH was oxidized by diaphorase with the consequent reduction fromresazurin to resorufin. This latter was detected by LIF using an excitation wavelength of 535 nm and an emission of 580 nm in a synchronized video microscope. We compare the responses of the PADs with and without nanomaterials to demonstrate the improved analytical performance of the developed devices. For this, the PADs were modified with the same concentration of horseradish peroxidase (HRP). The fluorescent signal obtained from the PADs with nanomaterials was higher than that of the unmodified PADs.Our method exhibited within- and between-assay variation coefficients below 5.23% and 6.67%, was 0.125 μM. The proposed fPAD allowed the simple, rapid, low-cost, and sensitivedetection of Phe in neonatal blood samples. Fil: Moreira, Cristian Matias. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentina Fil: Marin Barroso, Evelyn del Valle. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentina Fil: Pereira, Sirley Vanesa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentina Fil: Raba, Julio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentina Fil: Messina, Germán Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentina Fil: Bertolino, Franco Adrián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentina

Uniformly dispersing silver nanowires (AgNWs) in polymer matrices is of paramount importance for developing high-performance electromagnetic interference (EMI) shielding materials. Herein, new flexible and robust high-efficiency bacterial cellulose (BC)-based EMI shielding papers were developed via a modified step-by-step in situ biosynthesis method, in which, AgNWs were well distributed in the BC network. The BC nanofibers and AgNWs could form an effective entangled network with hydrogen bonding, efficiently strengthening the produced BC/AgNW papers. An electrical conductivity of 608365 S m1 was achieved for a BC/AgNW paper with a AgNW content of 36.5 wt%, which is superior to almost all AgNW-containing papers reported so far. Moreover, the BC/AgNW paper could sustain mechanical deformation and vigorous washing, without losing electrical conductivity. Additionally, this paper presents an ultrahigh specific EMI shielding effectiveness of 6400 dB mm1, which is higher than almost all previously reported AgNW-based polymer composites. The proposed approach in this study provides a facile and scalable fabrication route for producing flexible and highly conductive BC/AgNW papers, which are of great potential as electrically conductive components and EMI shielding elements in advanced applications., This work was supported by the National Natural Science Foundation of China (Grant Nos. 51973058 and 31870963), Jiangxi Provincial Natural Science Foundation (Grant No. 20202ACBL214007), Key Research and Development Program of Jiangxi Province (Grant No. 20192ACB80008) and the Key Project of Natural Science Foundation of Jiangxi Province (20202ACBL204013)., info:eu-repo/semantics/publishedVersion

For the first time, a novel analytical method based on a paper based enzymatic biosensor assisted by digital image processing and first-order multivariate calibration has been reported for rapid determination of nitrate in food samples. The platform of the biosensor includes a piece of Whatman filter paper impregnated with Griess reagent (3-nitroaniline, 1-naphthylamine and hydrochloric acid) and nitrate reductase. After dropping a distinct volume of nitrate solution onto the biosensor surface, nitrate reductase selectively reduces nitrate to nitrite and then the Griess reagent selectively reacts with nitrite to produce a red colored azo dye. Therefore, the color intensity of the produced azo dye is correlated with nitrate concentration. After image capture, the images were processed and digitized in the MATLAB environment by the use of an image processing toolbox and the vectors produced by the digital image processing step were used as inputs of the first-order multivariate calibration algorithms. Several multivariate calibration algorithms and pre-processing techniques have been used to build multivariate calibration models for verifying which technique offers the best predictions towards nitrate concentrations in synthetic samples and the best algorithm has been chosen for nitrate determination in potato, onion, carrot, cabbage and lettuce samples as real cases. Fil: Jalalvand, Ali R.. Kermanshah University Of Medical Sciences; Irán Fil: Mahmoudi, Majid. Kermanshah University Of Medical Sciences; Irán Fil: Goicoechea, Hector Casimiro. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Litoral; Argentina

The design of selective and efficient catalysts for electrochemical CO2 reduction is highly desirable yet still challenging, in particular, if the aim is to make them binder-free and self-standing. Here, we report a new and straightforward strategy to incorporate Ni single atoms into a commercially available carbon paper to prepare a self-standing electrode. This is accomplished by consecutive acid activation, adsorption of Ni2+ ions, and pyrolysis steps. Structural characterizations and calculations based on density functional theory consistently suggest that the Ni single atoms are coordinated with three N and one S atoms on the carbon paper. When used for CO2 electroreduction, the electrode exhibits an optimal selectivity (91%), activity (3.4 mA cm-2), and stability (at least 14 h) for CO production in water at an overpotential of 660 mV. This report may inspire the design and incorporation of single atoms of various metal types into carbon papers, or other kinds of carbon substrates, for a wide range of electrocatalytic processes. This journal is

A series of bio-based additives derived from citric acid as a renewable chemical source were synthesised. The chemical composition and purity of 1–4 were confirmed by the combination of NMR, FTIR and MS. The thermal behaviour, stability and degradation pattern of the compounds 1–4 were investigated by TGA and DSC methods. PVC based formulations with compounds 1–4 were prepared through a simple mixing method. The formulations were treated at different temperatures (130–210 °C) to investigate the potential of these materials in industrial curing settings. L*a*b* data were used to monitor and to assess a colour change in the coated paper samples; this showed a correlation with degradation data of the pure compounds 1–4. SEM analysis of the final paper samples indicated that the compounds 1–4 show gas formation within the cellular structure; however compounds 3 and 4 result in a glossy smooth surface. This study showed that the compounds 3 and 4 exhibit promising properties in PVC formulations for application in industrial settings.

Reduced graphene oxide (rGO) integrated nano-fibrillated cellulose (NFC) grafted poly(ionic liquid) (PIL) composite paper with enhanced hydrophobicity, ductility and toughness was fabricated by vacuum filtration of an aqueous dispersion of rGO/NFC-graft-PIL (NFC-g-PIL). The NFC-g-PIL was synthesized by growing PIL chains from the NFC surface using free radical polymerization of a pyridinium acrylate-based ionic liquid monomer. publishedVersion

Depending on the reaction conditions, either guest or host truncation is observed upon self-assembly of [Cp*Fe(η5-P5)], [(CpCr)2(η5-As5)] and copper halides., Pentaphosphaferrocene [Cp*Fe(η5-P5)] in combination with Cu(i) halides is capable of a template-directed synthesis of fullerene-like spheres. Herein, we present the use of a triple decker complex as template that leads to the formation of unprecedented ‘nano-bowls’. These spherical domes resemble the truncated fullerenes Ih-C80 and represent a novel spherical arrangement in the chemistry of spherical molecules.

Colorimetric detection methods that produce results readable by eye are important for diagnostic tests in resource-limited settings. In this work, we have compared three main types of colorimetric methods – enzymatic reactions, silver deposition catalyzed by gold nanoparticles, and polymerization-based amplification – in a paper-based immunoassay for detection of Plasmodium falciparum histidine-rich protein 2, a biomarker of malarial infection. We kept the binding events in the immunoassay constant in order to isolate the effect of the detection method on the outcome of the test. We have highlighted that the optimal readout time in a test can vary significantly – ranging from immediately after addition of a visualization agent to 25 minutes after addition of a visualization agent – depending on the colorimetric method being used, and accurate time keeping is essential to prevent false positives in methods where substantial color develops over time in negative tests. We have also shown that the choice of a colorimetric method impacts the calculated limit-of-detection, the ease of visual perception of the readout, and the total cost of the assay, and therefore directly impacts the feasibility and the ease-of-use of a test in field settings., Massachusetts Institute of Technology (Jonathan Whitney Fund), Massachusetts Institute of Technology (Haas Family Fellowship in Chemical Engineering), Massachusetts Institute of Technology (Charles E. Reed Faculty Initiative Fund)

The gluten-free diet is a unique, effective treatment for different conditions related to gluten consumption. Therefore, it is crucial the availability of new methodologies for the sensitive and specific determination of gluten content in food samples. Herein, a screen printed electrode modified with carbon nanofibers coupled to a paper immunoaffinity platform was reported for the determination of gliadin in foods samples. The paper microzone covalently functionalized with specific anti-gliadin antibodies was placed on the modified electrode surface for the electrochemical determination of gliadin. The surface of the electrode modified with carbon nanofibers was characterized by scanning electron microscopy (SEM) and cyclic voltammetry (CV), which showed the improved sensitivity of the modified surface. The developed device was evaluated using different flour samples obtaining a favorable response. The calculated limit of detection for the device in analyzed samples was 0.005 mg kg -1 and for the enzyme-linked immunosorbent assay was 1.5 mg kg -1 . The coefficient of variation (CV) for the determination of 20 μg kg -1 of gliadin was 4.11%. The disposable electrochemical sensor developed, represents an easy-to-use and low-cost strategy for the determination of gliadin in food samples. Fil: Marin Barroso, Evelyn del Valle. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentina Fil: Messina, Germán Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentina; Argentina Fil: Bertolino, Franco Adrián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentina; Argentina Fil: Raba, Julio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentina; Argentina Fil: Pereira, Sirley Vanesa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentina; Argentina

Reproduced from Ref. Green Chem., 2016,18, pp. 1117-1124. with permission from the Royal Society of Chemistry., Recent progress in portable and wearable electronics has promoted a growing demand for high-performance and flexible energy-storage devices that are abundant and affordable. Because reduced graphene oxide (rGO), originating from inexpensive graphite, serves as a higher-performance energy-storage electrode than conventional activated carbons and carbon nanotubes, research and development of rGO/polymer composite electrodes for flexible supercapacitors have become a center of attraction. However, the fabrication of rGO-based flexible electrodes frequently requires a long time with high-temperature treatment or toxic chemical treatment, resulting in the lack of scalability and eco-friendliness. Here we show a fast, scalable, and environment-compatible route to fabricate a high-performance rGO/cellulose paper supercapacitor electrode. Single-layer graphene oxide (GO) sheets and recycled waste pulp fibers were successfully fabricated into a paper composite by a well-established scalable papermaking process, followed by a room-temperature, additive-free, and millisecond-timescale flash reduction process. The as-prepared rGO/paper electrode had a high specific capacitance, up to 212 F g-1, for an all paper-based flexible supercapacitor, comparable to those of state-of-the-art rGO-based electrodes, while dramatically decreasing the reduction time of GO from the conventional hour timescale to milliseconds. This work will pave the way for green, flexible, and mass-producible energy-storage paper in future wearable electronics.

In this work, an Android application for measurement of nitrite concentration and pH determination in combination with a low-cost paper-based microfluidic device is presented. The application uses seven sensing areas, containing the corresponding immobilized reagents, to produce selective color changes when a sample solution is placed in the sampling area. Under controlled conditions of light, using the flash of the smartphone as a light source, the image captured with the built-in camera is processed using a customized algorithm for multidetection of the colored sensing areas. The developed image-processing allows reducing the influence of the light source and the positioning of the microfluidic device in the picture. Then, the H (hue) and S (saturation) coordinates of the HSV color space are extracted and related to pH and nitrite concentration, respectively. A complete characterization of the sensing elements has been carried out as well as a full description of the image analysis for detection. The results show good use of a mobile phone as an analytical instrument. For the pH, the resolution obtained is 0.04 units of pH, 0.09 of accuracy, and a mean squared error of 0.167. With regard to nitrite, 0.51% at 4.0 mg L(-1) of resolution and 0.52 mg L(-1) as the limit of detection was achieved.

The transport of molecules and particles across adjacent flow streams is a key process in several operations implemented in microfluidic paper-based analytical devices (μPADs). Here, the transverse dispersion of analytes was quantitatively evaluated by theory and experiments. Different tests were carried out to independently measure the coefficients of both Brownian diffusion and mechanical dispersion under capillary-driven flow. The dispersion width was found to be independent of fluid velocity and analyte properties, and fully determined by the dispersivity coefficient, which is a characteristic of the paper microstructure. This information introduces a change of paradigm for the design of mixers, diluters, and concentration gradient generators on μPADs; therefore, efforts were made to rationalize these operations on paper. The research reveals that mixers and concentration gradient generators can be much more efficient than their counterparts made on conventional microchannels; in contrast, separators such as the H-filter need to be appropriately engineered on paper, because the working principle can be hindered by mechanical dispersion. The knowledge gained throughout this work would contribute to the design of μPADs with a new level of precision and control over the formation of localized concentration profiles. Fil: Urteaga, Raul. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Física del Litoral. Universidad Nacional del Litoral. Instituto de Física del Litoral; Argentina Fil: Elizalde, Emanuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Física del Litoral. Universidad Nacional del Litoral. Instituto de Física del Litoral; Argentina Fil: Berli, Claudio Luis Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina

Using a miniaturized near infrared spectrometer associated to chemometrics we developed a rapid and non destructive procedure to characterise paper and investigate its aging with the aim of solving dating problems. Two sets of paper were considered in this study (books and sheets) in order to ensure the results are not dependent of the storage conditions. The MicroNIR has the ability to distinguish paper according to the chemical composition of the surface as a function of the period of manufacturing. The optimized analytical platform is fast and simple, avoiding sample pre-treatment procedures. As a consequence, the approach may be considered as the optimal technology to carry out analysis of ancient paper or other similar materials for diagnostic or forensic purposes as it is entirely portable and non-destructive.

In this work, an application of a design of experiments approach for the optimization of an isoniazid assay on a single-area inkjet-printed paper-based analytical device (PAD) is described. For this purpose, a central composite design was used for evaluation of the effect of device geometry and amount of assay reagents on the efficiency of the proposed device. The factors of interest were printed length, width, and sampling volume as factors related to device geometry, and amounts of the assay reagents polyvinyl alcohol (PVA), NH4OH, and AgNO3. Deposition of the assay reagents was performed by a thermal inkjet printer. The colorimetric assay mechanism of this device is based on the chemical interaction of isoniazid, ammonium hydroxide, and PVA with silver ions to induce the formation of yellow silver nanoparticles (AgNPs). The in situ-formed AgNPs can be easily detected by the naked eye or with a simple flat-bed scanner. Under optimal conditions, the calibration curve was linear in the isoniazid concentration range 0.03-10 mmol L-1 with a relative standard deviation of 3.4% (n = 5 for determination of 1.0 mmol L-1). Finally, the application of the proposed device for isoniazid determination in pharmaceutical preparations produced satisfactory results.

Electrically conductive flexible carbon papers were prepared, based on hydroxyl functionalized few layer graphene (G-OH). G-OH was obtained from the reaction of KOH with nanosized graphite with a very high surface area (HSAG), greater than 300 m2 g−1, and with high shape anisotropy, with the help of mechanical and thermal energy. Wide angle X-ray and Raman analyses showed that the core of G-OH had the structure of infinite and ideal graphene layers and that the interlayer distance between the few stacked graphene layers was the same as in pristine HSAG. Hydroxyl groups were thus essentially located in peripheral positions. High resolution transmission electron microscopy revealed the presence of graphene aggregates made by a number of layers as low as 6. Stable water suspensions were obtained, with concentrations up to 4 mg mL−1. Mild centrifugation of such suspensions had interesting efficiency as a method for producing few layer graphene: about 35% by mass of pristine HSAG was isolated as few layer graphene from supernatant suspensions. Flexible and electrically conductive carbon papers were prepared by coating a paper support with a G-OH water suspension. This work demonstrates that carbon papers can be prepared without adopting the traditional oxidation–reduction procedure, avoiding harsh reaction conditions, dangerous and toxic reagents, solvents and catalysts.

A rhodium(III) complex, [Rh(MQ)(DMSO)2Cl2] (1), with 8-hydroxy-2-methylquinoline as the ligand was synthesized and characterized. Complex 1 exhibited cytotoxicity against BEL-7404, Hep-G2, NCI-H460, T-24, and A549 cell lines with IC50 values in the micromolar range (6.52–17.86 μM). Various experiments on the Hep-G2 cells showed that complex 1 caused cell cycle arrest at the S phase, downregulation of cdc25 A, cyclin A, cyclin B and CDK2, and upregulation of p21, p27 and p53. Furthermore, cytotoxicity mechanism studies suggested that complex 1-induced apoptosis was achieved via disruption of the mitochondrial function, which led to a significant loss of the mitochondrial membrane potential, an increase in the cellular levels of reactive oxygen species, cytochrome c, and apaf-1, and a fluctuation of the intracellular Ca2+ concentration. Taken altogether, complex 1 can trigger cancer cell death by inducing apoptosis through a mitochondrial dysfunction pathway.

This paper aims to evaluate the reduction in greenhouse gas emissions of rice and wheat and their supply chains by incorporating carbon capture, utilisation and storage into fertiliser production mainly from the ammonia process, which is a part of the fertiliser that produces most of the carbon dioxide. Greenhouse gas emissions of these grains without carbon capture, utilisation and storage are provided from the results of life cycle assessment in the literature. After that, carbon dioxide emission from fertiliser production is quantified. The alternative considered for utilisation is enhanced oil recovery and it is compared with the conventional way of oil production. The effects of carbon capture, utilisation, and storage on greenhouse gas reduction are presented in terms of the supply chains of rice and wheat to make people conscious about the use and optimisation of food. The reduction of greenhouse gas is around 6–7% in the rice supply chain e.g. rice milk, spoons of uncooked rice and 14–16% in the wheat supply chain e.g. pasta, one slice of bread. Although the alternative for carbon dioxide storage demonstrates marginally higher greenhouse gas reduction, enhanced oil recovery may offer an economic incentive from additional oil production that could reduce the cost of rice and wheat.

Sodium dithionite is utilized as a reducing agent in the organosolv fractionation of lignocellulose to concomitantly produce cellulosic pulp and promote the reductive conversion of lignin into phenolic monomers. Reactions with model compounds highlight the role of sodium dithionite with respect to the reductive cleavage of β-O-4 bonds in lignin and the consequent formation of phenolic monomers.

Quaternary ammonium compounds (QACs) are broad-spectrum disinfectants used in a range of everyday materials. Their high usage rates, limited regulation and reporting has meant their environmental release is largely uncontrolled and impact unknown. With links to antimicrobial resistance (AMR) and adsorption to wastewater solids (that are recycled), there is a need for more controlled disposal measures and monitoring. These environmental matrices are highly complex requiring methods that are often laborious and costly to undertake. Using a robust quantitative reversed-phase LC-MS/MS method, we have shown that an ‘off the shelf’ QuEChERS product can reliably extract (

Flint biosolids monitoring data demonstrate a sustained decline in total lead release to potable water from plumbing since the 2014–2015 Flint Water Crisis (FWC), due to enhanced corrosion control treatment (3 mg L−1 orthophosphate as PO4) and removing of ∼80% of lead and galvanized iron service lines through early 2020. The official 90th percentile water lead levels, which have now met the federal Lead and Copper Rule threshold of 15 μg L−1 for the last four years, are in agreement with those predicted by a previously established biosolids regression model. There is also no longer a correlation between the percentage of children under 6 years of age with blood lead ≥ 5 μg dL−1 and biosolids lead mass in the 44 months post-FWC (Nov 2015–Jun 2019), nor are there continued correlations between plumbing-related metals in the biosolids, with the exception of Cu:Zn found in brass alloys that remain installed in homes. After Flint achieves 100% replacement of lead and galvanized service line pipes, a biosolids data analysis predicts that the remaining sources of waterborne lead including leaded brass, lead solder and legacy lead in pipe scale, will still release about 16–28% of the pre-FWC lead mass to potable water. The efficacy of enhanced corrosion control and replacement of service lines that contain lead is, therefore, on the order of 72–84% effective at reducing citywide lead exposure, yet some significant water lead sources will still remain even after pipe replacement is complete.

The process of stabilization is essential in the production of carbon fibers from lignins. During stabilization, the initially thermoplastic lignin polymer is converted to a thermoset polymer allowing for high-temperature treatment without a change in shape. In this work, hardwood (HKL) and softwood (SKL) Kraft lignins were stabilized in air at temperatures between 190 and 340 °C before carbonization at 800 °C in a nitrogen atmosphere. Due to the differences in side-chain linkages, functional groups and molar mass, the lignins exhibit different structural changes upon stabilization and hence develop different porosities upon carbonization. Both lignins undergo major crosslinking reactions in the side chains at low temperatures and degradation reactions at high temperatures during stabilization. Crosslinking gives rise to narrow pore size distributions with mainly (sub-) nanometer pores, whereas degradation reactions lead to a more open pore structure with additional mesoporosity (>2 nm). When both types of reactions take place simultaneously, highly accessible (sub-) nanoporosity can be effectively created, which boosts the performance of supercapacitors operating in 6 M KOH(aq). This effect terminates when the crosslinking reactions cease and mainly degradation reactions take place, which occurs in HKL at 340 °C. SKL shows both a lower degree of crosslinking and degradation and hence develops less specific surface area. The optimum performance in an aqueous alkaline supercapacitor is achieved with HKL stabilized at 310 °C. It shows a specific gravimetric capacitance of 164 F g−1 at 0.1 A g−1 and 119 F g−1 at 250 A g−1 with a capacitance retention of more than 90% after 10 000 cycles. M. J. M. L. and D. C. A. thank Spanish Ministry of Science, Innovation and Universities and FEDER (project RTI2018-095291-B-I00) for financial support. C. P. G. and C. O'K. thank Shell. MMT and PS thank RISE AB for co-funding Philipp Schlee's PhD position.

Softwood is an abundantly available feedstock for the bio-based industry. However, achieving cost-effective sugar release is particularly challenging, owing to its guaiacyl-only lignin. Here, we report the highly effective pretreatment of the softwood pine (Pinus sylvestris) using ionoSolv pretreatment, a novel ionic liquid-based lignocellulose fractionation technology. Three protic, low-cost ionic liquids, 1-butylimidazolium hydrogen sulfate, triethylammonium hydrogen sulfate and N,N-dimethylbutylammonium hydrogen sulfate, were used to fractionate the biomass into a carbohydrate-rich pulp and a lignin. The carbohydrate-rich pulp was hydrolysed into fermentable sugars by enzymatic saccharification. Under the most successful pretreatment conditions, quantitative glucose release from the pulp was achieved, which equates to a projected glucose release of 464 mg per gram of pine wood entering the process. We further intensified the process by increasing the solid to solvent ratio up to 1 : 2 g g−1 while maintaining saccharification yields of 75% of the theoretical maximum. We also demonstrate for the first time that N,N-dimethylbutylammonium hydrogen sulfate, [DMBA][HSO4], is an excellent low-cost pretreatment solvent, surpassing the pretreatment effectiveness of its symmetrically substituted analogue triethylammonium hydrogen sulfate. This shows that ionoSolv pretreatment with protic hydrogen sulfate ionic liquids is a truly feedstock-independent pretreatment option, further increasing the commercial potential of this pretreatment technology.

International audience; A rapid and effective dissolution and activation of cellulose was demonstrated by a reversible reaction of CO2 with the hydroxyl groups of the cellulose backbone in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU). The obtained carbonate complex of cellulose was subsequently subjected to in situ derivatization with succinic anhydride without the need of any additional catalyst under very mild conditions. As a result of optimization studies, cellulose was succesfully converted to cellulose succinates with degrees of substitution (DS) ranging from 1.51 to 2.64, depending on the reaction conditions and the molar ratio of succinic anhydride. The optimized reaction conditions were successfully applied to different types of cellulose samples including microcrystalline cellulose (MCC) and organosolv wood pulp (WP), exhibiting similar conversions. Furthermore, the carboxylic acid moiety, introduced by the succinylation, was further converted via Passerini three-component reactions (Passerini-3CR) and Ugi four-component reactions (Ugi-4CR). 31 P NMR revealed the quantitative conversions of carboxylic acid moieties on the cellulose backbone under mild conditions. The obtained products were thoroughly characterized by ATR-IR, 1 H, 13 C, and 31 P NMR spectroscopies as well as by gel permeation chromatography (GPC). Thermal properties of the obtained products were investigated by differential scanning calorimetry (DSC) and by thermogravimetric analysis (TGA), revealing glass transitions (Tg) for all the Passerini and Ugi products between 76-116 °C and high thermal stability between 263-290 °C. The reported methodology represents a very mild, highly efficient and sustainable route for the dissolution of cellulose and the synthesis of cellulose succinates. The subsequent modifications of the obtained cellulose succinates via multicomponent reactions resulted in materials with improved thermal properties and offers a straightforward and versatile modification strategy for cellulose.

The environmental impact of biomass processing can best be minimized by utilizing many components of the biomass and by getting maximum utility out of any solvent used. A Switchable-Hydrophilicity Solvent (SHS) has been used for a complete extraction of hydrophobic and hydrophilic molecules in the solvent's opposite-hydrophilicity states, thus simplifying microalgal biomass extraction and increasing the solvent usefulness.

The valorization of vegetable waste can create opportunities to produce new valuable bioplastics.In thisstudy, a one-step process to fully convert a variety of vegetable waste materials into bioplasticfilms is reported. The process is carried out in a diluted aqueous HCl solution at room temperature,it is easily scalable, and with no environmental concerns associated with the use of organic ordangerous chemicals. The generated bioplastics arecompletely biodegradable and environmentallyfriendly. Freestanding, flexible bioplastic films were obtained from vegetable waste like carrot,parsley, radicchio and cauliflower. They have similar mechanical properties with other bioplastics, like thermoplastic starch, and showed to have little migration in a food simulant. The color andthe functional properties (i.e. antioxidant capability) of the starting vegetables are preserved inthe bioplastics, thanks to the mild conditions of the fabrication process. The new conversionprocess allows the blending of the bioplastics with other natural or synthetic polymers, in order to improve their mechanical and gas barrier properties, like the oxygen permability (OP), thusexpanding their field of applications. Poly vinyl alcohol (PVA)/carrot bioplastic film showed an OPof 31.2 cm3 μm m−2 day−1 kPa−1, which is lower than the OP for other synthetic films, like highdensity polyethylene films (HDPE), and similar to edible materials like chitosan. &nbsp

Environmental concerns have brought attention to the requirement for more efficient and renewable processes for chemicals production. Lignin is the second most abundant natural polymer, and might serve as a sustainable resource for manufacturing fuels and aromatic derivatives for the chemicals industry after being depolymerised. In this work, the mediator 2,2′-azino-bis(3-ethylbenthiazoline-6-sulfonic acid) diammonium salt (ABTS), commonly used with enzyme degradation systems, has been evaluated by means of cyclic voltammetry (CV) for enhancing the oxidation of the non-phenolic lignin model compound veratryl alcohol and three types of lignin (organosolv, Kraft and lignosulfonate) in the ionic liquid 1-ethyl-3-methylimidazolium ethyl sulfate, ([C2mim][C2SO4]). The presence of either veratryl alcohol or organosolv lignin increased the second oxidation peak of ABTS under select conditions, indicating the ABTS-mediated oxidation of these molecules at high potentials in [C2mim][C2SO4]. Furthermore, CV was applied as a quick and efficient way to explore the impact of water in the ABTS-mediated oxidation of both organosolv and lignosulfonate lignin. Higher catalytic efficiencies of ABTS were observed for lignosulfonate solutions either in sodium acetate buffer or when [C2mim][C2SO4] (15 v/v%) was present in the buffer solution, whilst there was no change found in the catalytic efficiency of ABTS in [C2mim][C2SO4]–lignosulfonate mixtures relative to ABTS alone. In contrast, organosolv showed an initial increase in oxidation, followed by a significant decrease on increasing the water content of a [C2mim][C2SO4] solution.

Would it not be nice to have an organic solvent nanofiltration membrane made from renewable resources that can be manufactured as simply as producing paper? Here the production of nanofiltration membranes made from nanocellulose by applying a papermaking process is demonstrated. Manufacture of the nanopapers was enabled by inducing flocculation of nanofibrils upon addition of trivalent ions.

Electrodeposition of nanoparticles on graphene is described, providing a convenient approach for making graphene–nanoparticle composites as well as insight into the electrochemical activity of graphene. To avoid complications due to surface contamination, chemical vapour deposition grown graphene was used directly on its copper growth substrate. We identify and isolate two nanoparticle growth processes for both silver and palladium deposition: electroless deposition that appears to occur preferentially at defects and edges next to the underlying copper, and conventional electrodeposition that occurs uniformly across the graphene surface. We show that control over electrodeposited nanoparticle size and number density can be achieved through varying electrodeposition conditions. The resultant nanoparticles are homogeneously dispersed across the graphene surface, suggesting that here both edge-plane and basal-plane graphene sites are electroactive. These results demonstrate that, as with other carbon nanostructures, electrodeposition is a powerful and flexible tool for forming functional composites with graphene.

In this work, solar disinfection of wastewater was studied, focusing on the effect of selected environmental variables, namely light intensity, continuous/intermittent light delivery, and post-irradiation storage as well as dilution in lake water. These variables were studied for their effect on the disinfection efficiency and on post-irradiation survival/regrowth in undiluted wastewater and in wastewater diluted in lake water at different dilution rates. The bacterial inactivation curves were studied, and distinct kinetic phases were identified and interpreted. The dose primarily influenced the demonstration of phases and total inactivation times, independently of the irradiance. Intermittent illumination unevenly prolonged the required exposure time and highlighted the need for extended illumination times when unstable weather conditions are expected. Post-irradiation survival/regrowth in undiluted wastewater showed three distinct kinetic profiles, with transitions among them largely determined by the applied light dose. Lower doses resulted in similar inactivation profiles to the higher ones, when irradiation was followed by prolonged storage at high dilution rates in lake water. The studied factors show significant design and operation implications for solar wastewater applications based on local environmental conditions and water receptor restrictions.

The main goal of water companies is to deliver to each consumer microbiologically safe drinking water (DW), adequate in quantity and delivery pressure and acceptable in terms of taste, odour and appearance. Drinking water distribution systems (DWDS) are known to harbour biofilms, even in the continuous presence of a disinfectant. These biofilms are a source of planktonic bacteria, which will remain present when the water is delivered through a consumer’s tap. The presence of biofilms in DWDS constitutes one of the currently recognized hazards affecting the microbiological quality of the product and may lead to a number of unwanted effects on the organoleptic quality of the distributed water. Importantly, biofilms constitute a persistent reservoir of pathogenic microorganisms, which are responsible for several waterborne diseases. Antimicrobial products, particularly chlorine, have been the main weapons used to disinfect DW. Although this strategy is widespread, there are not yet standardized disinfection strategies with reliable efficacy in the control of biofilms. This review covers the advances in the knowledge of public health problems caused by the presence of biofilms in DWDS and the current strategies for DW disinfection and associated biofilms., This work was supported by the Operational Programme for Competitiveness Factors - COMPETE and by FCT - the Portuguese Foundation for Science and Technology through Project Bioresist - PTDC/EBB-EBI/105085/2008 (Manuel Simoes) and the post-doctoral grant SFRH/BPD/81982/2011 (Lucia C. Simoes).

Organic semiconductor materials are widely used in the field of organic electronic devices due to their wide variety, low price, and light weight. However, their developments are still restrained by their low stability and carrier mobility. Density functional theory (DFT) was used to study the influence of doped oxygen group elements (O, S, Se, and Te) on the properties of organic semiconductor materials (seven-membered benzothiophene, o-pentacene, thiophene derivatives, and pentacene) in this paper. Based on the calculation of EHOMO, ELUMO, ΔE, and total energy, the performances of organic semiconductor materials without and with doped elements were compared, and it was found that the doping of multi-element Te makes the material have high stability and potential high mobility. For these studied organic semiconductor materials, when the atoms of the doped site change in the order of O, S, Se, and Te, the carrier mobility gradually increases, and the molecules show a tendency of stability. In this paper, promising doping elements and doping methods for these studied molecules are determined through calculations and screening out suitable materials more efficiently and economically without a large amount of repetitive experimental work, which may provide a theoretical basis and guidance for preparing high-performance organic semiconductor materials.

This paper presents a comparison of a graph-based genetic algorithm (GB-GA) and machine learning (ML) results for the optimization of log P values with a constraint for synthetic accessibility and shows that the GA is as good as or better than the ML approaches for this particular property., This paper presents a comparison of a graph-based genetic algorithm (GB-GA) and machine learning (ML) results for the optimization of log P values with a constraint for synthetic accessibility and shows that the GA is as good as or better than the ML approaches for this particular property. The molecules found by the GB-GA bear little resemblance to the molecules used to construct the initial mating pool, indicating that the GB-GA approach can traverse a relatively large distance in chemical space using relatively few (50) generations. The paper also introduces a new non-ML graph-based generative model (GB-GM) that can be parameterized using very small data sets and combined with a Monte Carlo tree search (MCTS) algorithm. The results are comparable to previously published results (Sci. Technol. Adv. Mater., 2017, 18, 972–976) using a recurrent neural network (RNN) generative model, and the GB-GM-based method is several orders of magnitude faster. The MCTS results seem more dependent on the composition of the training set than the GA approach for this particular property. Our results suggest that the performance of new ML-based generative models should be compared to that of more traditional, and often simpler, approaches such a GA.

In this reply, we address the concerns that were raised about our paper on CsPbBr3 single crystals. M. Szafranski criticized the dielectric and DSC data in our original paper claiming that they were a ´ ffected by the experimental artefacts or poor quality of the investigated single crystals, as his DSC and dielectric data did not show any low temperature anomalies in CsPbBr3. We argue in this reply that our main conclusions were not made based on the DSC and dielectric experiments. Here, we emphasize the importance of other experiments like EPR and XRD that were performed to understand if there are any structural transformations of CsPbBr3 at low temperatures. We believe that M. Szafranski did not take ´ into account all the discussion that was presented in our original paper. We hope to clear the doubts in this reply. published

This paper describes the development of a test kit for the selective detection of glyphosate (GlyP). A copper(ii)-pyrocatechol violet complex was selected by a screening approach from a pool of 96 combinations of metal ions and commercially available indicators and subsequently incorporated as a detection zone into a hydrophobic C18 solid support. With this kit, detection of 20 μM GlyP in tap water by the “naked eye” is possible and quantifications by smartphone analysis with a limit of detection as low as 2.66 μM (450 μg L−1) have been demonstrated in a proof-of-principle study., This paper describes the development of a test kit for the naked-eye detection of glyphosate (GlyP) using a copper(ii)-pyrocatechol violet complex immobilized on a C18 solid support.

11 pags., 5 figs., 3 tabs. -- We adknowledge support by the CSIC Open Access Publication Initiative through its Unit Information Resources for Research (URICI). -- Open Access funded by Creative Commons Atribution Licence 3.0, Absolute total electron scattering cross sections (TCS) for nitrobenzene molecules with impact energies from 0.4 to 1000 eV have been measured by means of two different electron-transmission experimental arrangements. For the lower energies (0.4–250 eV) a magnetically confined electron beam system has been used, while for energies above 100 eV a linear beam transmission technique with high angular resolution allowed accurate measurements up to 1000 eV impact energy. In both cases random uncertainties were maintained below 5–8%. Systematic errors arising from the angular and energy resolution limits of each apparatus are analysed in detail and quantified with the help of our theoretical calculations. Differential elastic and integral elastic, excitation and ionisation as well as momentum transfer cross sections have been calculated, for the whole energy range considered here, by using an independent atom model in combination with the screening corrected additivity rule method including interference effects (IAM-SCARI). Due to the significant permanent dipole moment of nitrobenzene, additional differential and integral rotational excitation cross sections have been calculated in the framework of the Born approximation. If we ignore the rotational excitations, our calculated total cross section agrees well with our experimental results for impact energies above 15 eV. Additionally, they overlap at 10 eV with the low energy Schwinger Multichannel method with Pseudo Potentials (SMCPP) calculation available in the literature (L. S. Maioli and M. H. F. Bettega, J. Chem. Phys., 2017, 147, 164305). We find a broad feature in the experimental TCS at around 1.0 eV, which has been related to the formation of the NO2 anion and assigned to the p*(b1) resonance, according to previous mass spectra available in the literature. Other local maxima in the TCSs are found at 4.0 0.2 and 5.0 0.2 eV and are assigned to core excited resonances leading to the formation of the NO2 and O2 anions, respectively. Finally, for energies below 10 eV, differences found between the present measurements, the SMCPP calculation and our previous data for non-polar benzene have revealed the importance of accurately calculating the rotational excitation contribution to the TCS before comparing theoretical and experimental data. This comparison suggests that our dipole-Born calculation for nitrobenzene overestimates the magnitude of the rotational excitation cross sections below 10 eV., This study has partially been supported by the Spanish Ministerio de Ciencia, Innovacion y Universidades (Project FIS2016-80440) and CSIC (Project LINKA 20085). F. C. acknowledges Radiation Biology and Biophysics Doctoral Training Programme (RaBBiT, PD/00193/2012); UCIBIO (UIDB/04378/2020) and together with P. L. V. the Portuguese National Funding Agency FCT through the Research Grants CEFITEC (UIDB/00068/2020) and PTDC/FISAQM/31281/2017. M. J. B. thanks the Australian Research Council for funding through grants DP160102787 and DP180101655. The authors acknowledge Dr N. C. Jones for providing her full experimental TCS data on NBz molecules and Dr L. S. Maioli and Prof. M. H. F. Bettega for providing numerical tables of their SMCPP calculation and taking part in helpful discussions related to this paper. We acknowledge support of the publication fee by the CSIC Open Access Publication Support Initiative through its Unit of Information Resources for Research (URICI). Finally we also acknowledge Dr L. Campbell for his contributions to the final version of this paper.

Post-print This is a pre-copyedited, author-produced version of a paper published as: Richards, L.C., Davey, N.G., Gill, C.G. & Krogh, E.T. (2020). Discrimination and geo-spatial mapping of atmospheric VOC sources using full scan direct mass spectral data collected from a moving vehicle. Environmental Science: Processes & Impacts, 22(1), 173-186. https://doi.org/10.1039/C9EM00439D Volatile and semi-volatile organic compounds (S/VOCs) are ubiquitous in the environment, come from a wide variety of anthropogenic and biogenic sources, and are important determinants of environmental and human health due to their impacts on air quality. They can be continuously measured by direct mass spectrometry techniques without chromatographic separation by membrane introduction mass spectrometry (MIMS) and proton-transfer reaction time-of-flight mass spectrometry (PTR-ToF-MS). We report the operation of these instruments in a moving vehicle, producing full scan mass spectral data to fingerprint ambient S/VOC mixtures with high temporal and spatial resolution. We describe two field campaigns in which chemometric techniques are applied to the full scan MIMS and PTR-ToF-MS data collected with a mobile mass spectrometry lab. Principal Component Analysis (PCA) has been successfully employed in a supervised analysis to discriminate VOC samples collected near known VOC sources including internal combustion engines, sawmill operations, composting facilities, and pulp mills. A Gaussian mixture model and a density-based spatial clustering of application with noise (DBSCAN) algorithm have been used to identify sample clusters within the full time series dataset collected and we present geospatial maps to visualize the distribution of VOC sources measured by PTR-ToF-MS. The authors gratefully acknowledge Vancouver Island University and the University of Victoria for ongoing support of the Applied Environmental Research Laboratories and Graduate Student Researchers. The mobile mass spectrometry lab was made possible with the support of the Canada Foundation for Innovation (CFI32238) and the British Columbia Knowledge Development Fund. The research was supported through the Natural Sciences and Engineering Research Council of Canada (NSERC Discovery Grant 2016-06454), the Fraser Basin Council supported the project through their BC Clean Air Research Fund, and the MITACS Accelerate Program. Post-print This is a pre-copyedited, author-produced version of a paper published as: Richards, L.C., Davey, N.G., Gill, C.G. & Krogh, E.T. (2020). Discrimination and geo-spatial mapping of atmospheric VOC sources using full scan direct mass spectral data collected from a moving vehicle. Environmental Science: Processes & Impacts, 22(1), 173-186. https://doi.org/10.1039/C9EM00439D https://viurrspace.ca/bitstream/handle/10613/23488/GillKrogh.ES.2020.pdf?sequence=3

25I-NBOH is a new potent serotonin 5-HT2A receptor agonist recently identified in blotter paper seizures. This compound is a thermolabile molecule that undergoes degradation under routine gas chromatography– mass spectrometry analysis leading to misidentification. In this paper, the voltammetric behavior of 25I-NBOH and 2C-I was investigated and their electroanalytical characteristics were determined. A novel, fast and sensitive electrochemical method for the detection of 25I-NBOH using a SPCE is described and all method characteristics demonstrated the method to be analytically valuable. This method is selective and achieves full differentiation between 25I-NBOH, 2C-I and 25I-NBOMe.

This paper reports that various thermodynamic properties in aqueous media for certain individual ions and for compounds are linear functions of the inverse cube root of the solid respective ionic and compound solid state volumes, V m –1/3 . This is similar to the situation which has been fully exploited in solid state thermodynamics and out of which Volume–Based Thermodynamics, VBT evolved. A short resume of these various VBT applications is provided for the general reader and an improved lattice potential energy equation emerges using the state of the art data presented in this paper.

In this paper, small angle X-ray scattering has been used to study a series of ionic liquids, alkylammonium alkanoates ([N0 0 0 n][CmCO2]), with varying alkyl chain lengths in the cation and the anion. We investigate the behaviour and the structure of such ionic liquids in their neat state, and in binary mixtures with water. To the best of our knowledge, this is the first structural study dealing with the behaviour of propylammonium propanoate [N0 0 0 3][C2CO2], butylammonium propanoate [N0 0 0 4][C2CO2], propylammonium butanoate [N0 0 0 3][C3CO2] and butylammonium butanoate [N0 0 0 4][C3CO2] when mixed in water. Generally, in the ionic liquids containing alkyl chains on both the cation and the anion, the correlation distance and the resulting scattering peak, which signal intermediate range order, are affected equally by both of the chains. The interesting result obtained regarding these systems is that the shift of the pre- and principal peaks with the addition of water depends on the overall molar concentration of the chains and is generally cumulative. Although, for a given sum of cation and anion chain lengths, the shift is reliant on the cation-anion combination in the neat state, it is not the case in their mixtures with water. In some recent papers, it has been reported that with addition of water, the pre-peak position remains constant, but our results show a shift in both pre- and principal Q peaks.

Nitrogen oxides are considered to be important astrochemical precursors of complex species and prebiotics. However, apart from the hydrogenation of solid NO that leads to the surface formation of hydroxylamine, little is known about the full solid state reaction network involving both nitrogen and oxygen. Our study is divided into two papers, hereby called Part I and Part II. In the accompanying paper, we investigate the surface reactions NO + O/O_2/O_3 and NO + N with a focus on the formation of NO_2 ice. Here, we complement this study by measurements of the surface destruction of solid NO2, e.g., NO_2 + H/O/N. Experiments are performed in two separate ultra-high vacuum setups and therefore under different experimental conditions to better constrain the experimental results. Surface reaction products are monitored by means of Fourier Transform Reflection Absorption Infrared Spectroscopy (FT-RAIRS) and Temperature Programmed Desorption (TPD) techniques using mass spectrometry. The surface destruction of solid NO_2 leads to the formation of a series of nitrogen oxides such as NO, N_(2)O, N_(2)O_3, and N_(2)O_4 as well as HNO, NH_(2)OH, and H_(2)O. When NO_2 is mixed with an interstellar more relevant apolar (i.e., CO) ice, solid CO_2 and HCOOH are also formed due to interactions between different reaction routes. The astrophysical implications of the full nitrogen and oxygen reaction network derived from Parts I and II are discussed.

Total reflection X-ray fluorescence (TXRF) is a powerful technique for trace elemental analysis of various liquid samples. A small volume of the liquid sample is dropped onto a flat substrate, and the dried residue is measured using TXRF. Usually, the substrate surface is treated with a silicone solution to make it hydrophobic. Such hydrophobic substrates are useful to concentrate the analyte at a small point, leading to a dot-type residue. However, the solution sample will provide a residue with a height of several tens of μm depending on the matrix of the solution, in which self-absorption is a serious problem. In this paper, the authors applied a He atmospheric pressure plasma jet (APPJ) treatment to a glass substrate to obtain a hydrophilic surface. The chemical properties of the glass substrate surface were drastically changed by the application of the He APPJ. The contact angle of the liquid droplet was 5.2° on the APPJ-treated glass, while it was 88.8° on the glass with a silicone layer. A droplet of the liquid solution smoothly spread over the APPJ-treated glass substrate, leading to a thin film-like residue. The recovery and detection limits for TXRF analysis of a standard solution sample were improved especially for low-Z elements by using the APPJ-treated glass substrates. This new sample preparation technique was also applied for TXRF analysis of a red wine sample. We found that this hydrophilic glass substrate gave a film-like residue from a small droplet of the red wine. Reasonable TXRF quantitative results were obtained by the Ga internal standard method. The preliminary experimental results suggested that the film-type residue produced on the APPJ-treated substrate was effective in decreasing the matrix effect especially for low-Z elements.

Understanding the interplay between topology and ordering in systems on curved manifolds, governed by anisotropic interactions, takes a central role in many fields of physics. In this paper, we investigate the effects of lattice symmetry and local positional order on orientational ordering in systems of long-range interacting point quadrupoles on a sphere in the zero temperature limit. Locally triangular spherical lattices show long-range ordered quadrupolar configurations only for specific symmetric lattices as strong geometric frustration prevents general global ordering. Conversely, the ground states on Caspar-Klug lattices are more diverse, with many different symmetries depending on the position of quadrupoles within the fundamental domain. We also show that by constraining the quadrupole tilts with respect to the surface normal, which models interactions with the substrate, and by considering general quadrupole tensors, we can manipulate the ground state configuration symmetry., 16 pages, 8 figures, Supplemental material

Polymer self-assembly is used to form nanomaterials with a wide range of structures. While self-assembly of polymers in bulk has been thoroughly explored, the same process in solution remains widely used but partially unresolved, due to the formation of structures which are often kinetically trapped. In this paper we report kinetic state diagrams of polystyrene-b-poly(ethylene oxide) block copolymer in water by changing the solvent-switch assembly conditions. We study 36 different conditions for a single block copolymer, exploring three parameters: polymer concentration, temperature and rate addition of selective solvent. The data shows that polymer concentration plays an important role in determining which morphologies are accessible within a given set of experimental parameters and provides evidence that vesicles can evolve into particles with complex internal structures, supportive of recent mechanistic studies. Most importantly, the data shows a complex relationship between all parameters and the resulting kinetically trapped morphologies indicating that combinedin situandex situstudies are required to gain a fundamental understanding of kinetically controlled block copolymer assembly processes.

This paper presents the design and fabrication of a magnetic double network (DN) composite, which consists of permanent magnet chains embedded in an elastomer matrix, and was capable of large yet fully recoverable deformation. The initially connected magnets served as reusable sacrificial components in the composite. The strong magnetic attraction between neighboring magnetics endowed the composite with the high strength while the compliance of the elastomer matrix provided the high extensibility. Having a similar mechanism as DN gels, the composite was found to be significantly tougher than either of the constituents. The nonlinear behavior in the composite separated it into two coexisting phases - a softer phase with separated magnet links and a stiffer phase with connected magnet links - which led to the stress plateau on the tensile curve. Further stretching was manifested by the growth of the disconnected softer phase at the expense of the linked stiffer phase, until all magnets were separated. The unloading curves appeared drastically different from the loading curves, as the force needed to separate two magnets was much higher than the force at which two separated magnets snapped back. Such asymmetry between loading and unloading was the main cause of the hysteresis in the stress-strain curve and the energy dissipation. To further understand the physical mechanism and the damage process of the magnetic DN composite, a simple model was developed to examine the deformation and damage dissipation process of composite. With very few parameters, the model predictions agree qualitatively with the measured properties of the material, and the difference can be further reduced by accounting for the interfacial friction/adhesion, a second means of energy dissipation. With a combination of desired properties including high stretchability, self-healing, and high toughness, the magnetic DN composite is a viable candidate for various applications.

Age determination of minerals using the U–Pb technique is widely used to quantify time in Earth's history. A number of geochronology laboratories produce the highest precision U–Pb dates employing the EARTHTIME 202Pb–205Pb–233U–235U tracer solution for isotope dilution, and the EARTHTIME ET100 and ET2000 solutions for system calibration and laboratory intercalibration. Here, we report ET100 and ET2000 solution data from the geochronology laboratory of University of Geneva obtained between 2008 and 2021 and compare the most recent data with results from the geochronology laboratories of Princeton University and ETH Zürich. This compilation demonstrates that (i) the choice of the thermal ionization mass spectrometer model has no influence on precision and accuracy of the data; (ii) the often observed excess scatter of apparent ET100 solution 206Pb/238U dates can be mitigated by more careful tracer-sample equilibration; and (iii) natural zircon reference materials are not suitable for evaluating intra-laboratory repeatability and inter-laboratory reproducibility, since they combine several phenomena of natural system complexities (especially domains of different age within the same zircon grain, and residual loss of radiogenic lead in domains of high decay damage after chemical abrasion pre-treatment). We provide our best estimates of apparent dates for the ET100 solution (206Pb/238U date, 100.173 ± 0.003 Ma), for ET2000 solution (207Pb/206Pb date, 1999.935 ± 0.063 Ma), as well as for natural reference zircon Temora-2 (206Pb/238U date, 417.353 ± 0.052 Ma). These data will allow U–Pb laboratories to evaluate their analytical performance and to independently calibrate non-EARTHTIME tracer solutions in use., This paper presents U, Pb isotopic data of synthetic EARTHTIME solutions and natural reference materials together with suggestions how to ensure long-term intra- and inter-laboratory reproducibility of high-precision TIMS U–Pb geochronology.

Soft elastomers with their ability to integrate strain-adaptive stiffening and coloration have recently received significant research attention for application in artificial muscle and active camouflage. However, there is a lack of theoretical understanding of their complex molecular dynamics and mechanochromic coupling/decoupling. In this study, a topological dynamics model is proposed to understand the anchoring-mediated topology signature of self-assembled elastomers. Based on the constrained molecular junction model, a free-energy function is firstly formulated to describe the working principles of strain-adaptive stiffening and coloration in the self-assembled elastomer. A coupled ternary "rock-paper-scissors" model is proposed to describe the topological dynamics of self-assembly, mechanochromic coupling and mechanoresponsive stiffening of the self-assembled elastomers, in which there are three fractal geometry components in the topology network. Finally, the proposed models are verified using the experimental results reported in the literature. This study provides a fundamental approach to understand the working mechanism and topological dynamics in the self-assembled elastomers, with molecularly encoded stiffening and coloration.

Exosomes have been recognized as promising sources of biomarkers for early cancer diagnosis due to their important role in the occurrence and metastasis of cancer, and so the development of a sensitive low-cost detection method for exosomes is highly desirable. In this paper, we report a fluorescence method for the competitive detection of exosomes based on an aptamer specific to CD63 (an exosome transmembrane protein). Aptamer-modified magnetic beads were hybridized with a Cy3-labeled short sequence complementary to a region of the aptamer. In the presence of exosomes, the CD63 on the exosomes bound to the aptamer, resulting in the shedding of the short sequence into the supernatant. The quantity of the exosomes could be estimated by detecting the fluorescence intensity in the supernatant. This method could detect exosomes at a concentration as low as 1.0 × 105 particles per μL under optimal conditions, and the feasibility of the method for exosome detection in complex clinical samples was also proved using simulated serum samples. The detection cost and difficulty are significantly reduced compared to conventional methods, while ensuring sensitivity, and so this method provides a basis for subsequent exosome detection in specific cancer cells.

In Ce3+ activated SrLn2O4 type phosphors (Ln = Y, Lu, Sc, etc.) only one Ce3+ center was previously reported to show a blue emission band. In this paper, we report the observation of a second Ce3+ center in SrLu2O4:Ce3+. The new center shows a red emission band peaking at 600 nm with an excitation band at 485 nm. We attributed the new center (Ce(II)) to the substitution of the Lu3+ site and the original blue center (Ce(I)) to the substitution of the Sr2+ site. Spectroscopy studies indicate that Ce(I) centers are preferentially formed at a low doping concentration and the number ratio of Ce(I)/Ce(II) decreases with increasing Ce3+ concentration until beyond 0.002. The fluorescence lifetimes of the two centers were measured for various doping concentrations. Energy transfer from Ce(I) to Ce(II) was observed. It was found that the emission intensity of Ce(II) centers reduces much faster than that of Ce(I) with increasing temperature from 83 K up to 350 K, implying their potential application in temperature sensing based on their temperature dependent intensity ratios. A relative sensing sensitivity as high as 2.28% K−1 at 283 K was achieved.

This paper describes a straightforward electrochemical method for rapid and robust urinary microRNA (miRNA) quantification using disposable biosensors that can discriminate between urine from diabetic kidney disease (DKD) patients and control subjects. Aberrant miRNA expression has been observed in several major human disorders, and we have identified a urinary miRNA signature for DKD. MiRNAs therefore have considerable promise as disease biomarkers, and techniques to quantify these transcripts from clinical samples have significant clinical and commercial potential. Current RT-qPCR-based methods require technical expertise, and more straightforward methods such as electrochemical detection offer attractive alternatives. We describe a method to detect urinary miRNAs using diazo sulfonamide-modified screen printed carbon electrode-based biosensors that is amenable to parallel analysis. These sensors showed a linear response to buffered miR-21, with a 17 fM limit of detection, and successfully discriminated between urine samples (n = 6) from DKD patients and unaffected control subjects (n = 6) by differential miR-192 detection. Our technique for quantitative miRNA detection in liquid biopsies has potential for development as a platform for non-invasive high-throughput screening and/or to complement existing diagnostic procedures in disorders such as DKD., In this study we have developed an electrochemical microRNA biosensor sensitive to 17 fM and capable of detecting an established downregulation of urinary miR-192 in diabetic kidney disease patients.