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Calcium phosphate nanoparticles (60 nm) were stabilized with either polyethyleneimine (PEI; polycationic electrolyte) or carboxymethylcellulose (CMC; polyanionic electrolyte). Next, a silica shell was added and terminated with either azide or alkyne groups via siloxane coupling chemistry. The particles were covalently functionalized by copper-catalyzed azide-alkyne cycloaddition (CuAAC; click chemistry) with proteins or gold nanoparticles that carried the complementary group, i.e., either alkyne or azide. The model proteins hemoglobin and bovine serum albumin (BSA) were attached as well as ultrasmall gold nanoparticles (2 nm). The number of protein molecules and gold nanoparticles attached to each calcium phosphate nanoparticle was quantitatively determined by extensive fluorescent labelling and UV–Vis spectroscopy on positively (PEI) or negatively (CMC) charged calcium phosphate nanoparticles, respectively. Depending on the cargo and the nanoparticle charge, this number was in the range of several hundreds to thousands. The functionalized calcium phosphate particles were well dispersible in water as shown by dynamic light scattering and internally amorphous as shown by X-ray powder diffraction. They were easily taken up by HeLa cells and not cytotoxic. This demonstrates that the covalent surface functionalization of calcium phosphate nanoparticles is a versatile method to create transporters with firmly attached cargo molecules into cells.

The analysis of complex samples is a big analytical challenge due to the vast number of compounds present in these samples as well as the influence matrix components could cause in the methodology. In this way, comprehensive two-dimensional gas chromatography coupled to mass spectrometry (GC × GC–MS) is a very powerful tool to achieve the characterization of complex samples. Nevertheless, due to possible coelutions occurring in these matrices, mixed spectra are generally obtained with electron ionization (EI) which could extremely complicate the identification of the analytes. Thereby, new methodology setups are required to improve the confidence on the identification in non-targeted determinations. Here, we present a high-throughput methodology consisting of GC × GC with flow modulation coupled to high-resolution atmospheric pressure mass spectrometry (HRMS) via a novel tube plasma ion source (TPI). The flow modulator allows to easily automate the GC × GC method compared to traditional cryo-modulators, while the soft ionization provided by TPI helps to preserve the [M]+• or [M+H]+ ions, thus increasing the confidence in the identification. Additionally, the combination of a flow modulation with an atmospheric pressure mass spectrometer significantly improves the sensitivity over flow modulated GC × GC-EI-MS methods because no split is required. This methodology was applied to the analysis of a complex sample such as vermouth where the volatile profile is usually considered by consumers as a product quality indicator since it raises the first sensations produced during its consumption. Using this approach, different classes of compounds were tentatively identified in the sample, including monoterpenes, terpenoids, sesquiterpenoids and carboxylic acid, and carboxylate esters among others, showing the great potential of a GC × GC-TPI-qTOF-MS platform for improving the confidence of the identifications in non-targeted applications.

For various reasons, students receive less formative feedback at post-secondary institutions compared to secondary school. Considering feedback as one of the most important influencing factors on learning processes, formative feedback is a promising approach to improving students’ performances. In this context, new technologies, such as learning management systems (LMS) or intelligent tutoring systems (ITS), can make a valuable contribution to improving higher education teaching by providing automated and individualized error-specific just-in-time (JIT) feedback. However, the digitalization especially of paper-based open-ended tasks that can be used by LMS is currently still associated with a loss of quality. In this paper, we present an approach that allows us to transfer open-ended paper-based tasks in the field of chemistry into online tasks without losing quality and provide large university courses with automated and individualized error-specific JIT feedback. Results of a study of 238 first-year chemistry students reveal that the automated individualized error-specific JIT feedback had a significant positive influence on students’ performance.

Aromatic amines (AA) are carcinogenic compounds that can enter the human body through many sources, one of the most important being tobacco smoke. They are excreted with the urine, from which they can be extracted and measured. To that end, hollow fiber-liquid-phase microextraction (HF-LPME) and parallel artificial liquid membrane extraction (PALME) were optimized for the analysis of representative aromatic amines, as alternatives to liquid–liquid extraction (LLE). Relevant extraction parameters, namely organic solvent, extraction time, agitation speed, and acceptor solution pH, were studied, and the two optimized techniques—HF-LPME: dihexyl ether, 45 min, 250 rpm, and pH 1; PALME: undecane, 20 min, 250 rpm and pH 1—were compared. Comparison of the optimized methods showed that significantly higher recoveries could be obtained with PALME than with HF-LPME. Therefore, PALME was further validated. The results were successful for nine different AA, with regression coefficients (R2) of at least 0.991, limits of detection (LOD) of 45–75 ng/L, and repeatability and peak area relative standard deviations (RSD) below 20%. Furthermore, two urine samples from smokers were measured as proof of concept, and 2-methylaniline was successfully quantified in one of them. These results show that PALME is a great green alternative to LLE. Not only does it use much smaller volumes of toxic organic solvents, and sample—enabling the study of samples with limited available volumes—but it is also less time consuming and labor intensive, and it can be automated. Graphical Abstract

Membrane science and technology is growing rapidly worldwide and continues to play an increasingly important role in diverse fields by offering high separation efficiency with low energy consumption. Membranes have also shown great promise for “green” separation. A majority of the investigations in the field are devoted to the membrane fabrication and modification with the ultimate goals of enhancing the properties and separation performance of membranes. However, less attention has been paid to membrane life cycle management, particularly at the end of service. This is becoming very important, especially taking into account the trends toward sustainable development and carbon neutrality. On the contrary, this can be a great opportunity considering the large variety of membrane processes, especially in terms of the size and capacity of plants in operation. This work aims to highlight the prominent aspects that govern membrane life cycle management with special attention to life cycle assessment (LCA). While fabrication, application, and recycling are the three key aspects of LCA, we focus here on membrane (module) recycling at the end of life by elucidating the relevant aspects, potential criteria, and strategies that effectively contribute to the achievement of green development and sustainability goals.

In the last decade, trends for competing electrocatalytic processes have been largely captured by volcano plots, which can be constructed by the analysis of adsorption free energies as derived from electronic structure theory in the density functional theory approximation. One prototypical example refers to the four-electron and two-electron oxygen reduction reactions (ORRs), resulting in the formation of water and hydrogen peroxide, respectively. The conventional thermodynamic volcano curve illustrates that the four-electron and two-electron ORRs reveal the same slopes at the volcano legs. This finding is related to two facts, namely, that only a single mechanistic description is considered in the model, and electrocatalytic activity is assessed by the concept of the limiting potential, a simple thermodynamic descriptor evaluated at the equilibrium potential. In the present contribution, the selectivity challenge of the four-electron and two-electron ORRs is analyzed, thereby accounting for two major expansions. First, different reaction mechanisms are included into the analysis, and second, Gmₐₓ(U), a potential-dependent activity measure that factors overpotential and kinetic effects into the evaluation of adsorption free energies, is applied for approximation of electrocatalytic activity. It is illustrated that the slope of the four-electron ORR is not constant at the volcano legs but rather is prone to change as soon as another mechanistic pathway is energetically preferred or another elementary step becomes the limiting one. Due to the varying slope of the four-electron ORR volcano, a trade-off between activity and selectivity for hydrogen peroxide formation is observed. It is demonstrated that the two-electron ORR is energetically preferred at the left and right volcano legs, thus opening a new strategy for the selective formation of H₂O₂ by an environmentally benign route. CA Exner

Abstract Diclofenac, ibuprofen, and carbamazepine are three of the most widely detected and most concerning pharmaceutical residues in aquatic ecosystems. The aim of this study was to identify bacteria that may be involved in their degradation from a bacterial biofilm. Selective enrichment cultures in mineral salt solution containing pharmaceutical compounds as sole source of carbon and energy were set up, and population dynamics were monitored using shotgun metagenome sequencing. Bacterial genomes were reconstructed using genome-resolved metagenomics. Thirty bacterial isolates were obtained, identified at species level, and tested regarding pharmaceutical biodegradation at an initial concentration of 1.5 mg l−1. The results indicated that most probably diclofenac biodegrading cultures consisted of members of genera Ferrovibrio, Hydrocarboniphaga, Zavarzinia, and Sphingopyxis, while in ibuprofen biodegradation Nocardioides and Starkeya, and in carbamazepine biodegradation Nocardioides, Pseudonocardia, and Sphingopyxis might be involved. During the enrichments, compared to the initial state the percentage relative abundance of these genera increased up to three orders of magnitude. Except Starkeya, the genomes of these bacteria were reconstructed and annotated. Metabolic analyses of the annotated genomes indicated that these bacteria harbored genes associated with pharmaceutical biodegradation. Stenotrophomonas humi DIC_5 and Rhizobium daejeonense IBU_18 isolates eliminated diclofenac and ibuprofen during the tests in the presence of either glucose (3 g l−1) or in R2A broth. Higher than 90% concentration reduction was observed in the case of both compounds.

Raman spectra obtained by UV laser excitation above 260 nm are contaminated by spectrally overlapping UV-excited fluorescence. Here, we demonstrate a picosecond UV Kerr-gated Raman spectroscopy setup to suppress the fluorescence in Raman spectra excited by 280 nm laser pulses. Specifically, we use a model sample that consists of acetonitrile contaminated by a small amount of toluene for generating UV-excited fluorescence. We were able to acquire a Raman spectrum of acetonitrile by suppressing the UV-excited fluorescence of toluene by the action of a 1-mm thick fused silica-based UV Kerr gate operated by 1030 nm, ~1 ps gating pulses. These results also indicate the challenges that must be overcome in the future for realizing UV-fluorescence-free UV resonance Raman (UVRR) spectroscopy studies of molecules exhibiting electronic resonances around 280 nm using laser excitation wavelengths right at or close to this resonance.

High spatial resolution mass spectrometry imaging has been identified as a key technology needed to improve understanding of the chemical components that influence antibiotic resistance within biofilms, which are communities of micro-organisms that grow attached to a surface. Time-of-flight secondary ion mass spectrometry (ToF–SIMS) offers the unique ability for label-free 3D imaging of organic molecules with sub-micrometer spatial resolution and high sensitivity. Several studies of biofilms have been done with the help of ToF–SIMS, but none of those studies have shown 3D imaging of antibiotics in native-state hydrated biofilms with cell-level resolution. Because ToF–SIMS measurements must be performed in a high-vacuum environment, cryogenic preparation and analysis are necessary to preserve the native biofilm structure and antibiotic spatial distribution during ToF–SIMS measurements. In this study, we have investigated the penetration of the antibiotic ciprofloxacin into Bacillus subtilis biofilms using sub-micrometer resolution 3D imaging cryo-ToF–SIMS. B. subtilis biofilms were exposed to physiologically relevant levels of ciprofloxacin. The treated biofilms were then plunge-frozen in liquid propane and analyzed with ToF–SIMS under cryogenic conditions. Multivariate analysis techniques, including multivariate curve resolution (MCR) and inverse maximum signal factor (iMSF) denoising, were used to aid analysis of the data and facilitate high spatial resolution 3D imaging of the biofilm, providing individually resolved cells and spatially resolved ciprofloxacin intensity at “real world” concentrations. Graphical Abstract

In the present study, DOPO-based alkoxysilane (DOPO-ETES) and amido alkoxysilane (DOPO-AmdPTES) were synthesized by one-step and without by-products as halogen-free flame retardants. The flame retardants were applied on cotton fabric utilizing sol–gel method and pad-dry-cure finishing process. The flame retardancy, the thermal stability and the combustion ehaviour of treated cotton were evaluated by surface and bottom edge ignition flame test (according to EN ISO 15025), thermogravimetric analysis (TGA) and micro-scale combustion calorimeter (MCC). Unlike CO/DOPO-ETES sample, cotton treated with DOPO-AmdPTES nanosols exhibits self-extinguishing ehaviour with high char residue, an improvement of the LOI value and a significant reduction of the PHRR, HRC and THR compared to pristine cotton. Cotton finished with DOPO-AmdPTES reveals a semi-durability after ten laundering cycles keeping the flame-retardant properties unchanged. According to the results obtained from TGA-FTIR, Py-GC/MS and XPS, the major activity of flame retardant occurs in the condensed phase via catalytic induced char formation as physical barrier along with the activity in the gas phase derived mainly from the dilution effect. The early degradation of CO/DOPO-AmdPTES compared to CO/DOPO-ETES, triggered by the cleavage of the weak bond between P and C=O, as the DFT study indicated, provides the beneficial effect of this flame retardant on the fire resistance of cellulose. Graphical abstract

The black-odor water body restoration is an unfinished business in protecting and maintaining the ecological functions of natural water systems in China. Magnetic coagulation (MC) had found a vast application prospect for its high-efficient separation. In this work, the performance of MC was analyzed to explore its role in natural water protection, with a focus on identification and removal mechanisms of the dissolved organic matters (DOM) by absorption and fluorescence spectroscopy in terms of the spectroscopic indices, two-dimensional correlation spectroscopy (2D-COS), and parallel factor analysis (PARAFAC) methods. MC presented an excellent performance for suspended and colloidal matters, phosphorus, and DOMs, and showed high adaptability in pollution interception and water restoration. Tryptophan-like, tyrosine-like, and humics were identified as the key components in the wastewater, which were mainly recently produced or microbial-derived. The targeted pollutants were DOMs with high molecular weight, hydrophobicity, polarity, and aromaticity for the high affinity with the hydrolyzed Al species. Polyaluminum chloride (PAC) was the key in dissolved pollutants removal, while the mix stage is crucial for DOMs with low MW or humic-like substances as PAM facilitated the flocs formation and the absorption process. However, the residual PAM and the redissolved DOMs from the recycled magnetic seeds also act as the DOM source. This work identified the DOM composition and removal mechanism in MC, which would promote its application in natural water protection. CA extern

Poly(oxanorbornene)s bearing TPP and PEGylated ZnPc with varying compositions have been synthesized. Thus, highest reported singlet oxygen generation for a Pc derivative in water (ΦΔ = 0.93) and excellent biological activity have been accomplished.

Lysine-selective molecular tweezers (MTs) are supramolecular host molecules displaying a remarkably broad spectrum of biological activities. MTs act as inhibitors of the self-assembly and toxicity of amyloidogenic proteins using a unique mechanism. They destroy viral membranes and inhibit infection by enveloped viruses, such as HIV-1 and SARS-CoV-2, by mechanisms unrelated to their action on protein self-assembly. They also disrupt biofilm of Gram-positive bacteria. The efficacy and safety of MTs have been demonstrated

The phase width of the copper hydroxycarbonate malachite, Cu

Sterilization is a major prerequisite for the utilization of nanoparticle colloids in biomedicine, a process well examined for particles derived from chemical synthesis although highly underexplored for electrostatically stabilized ligand-free gold nanoparticles (AuNPs). Hence, in this work, we comprehensively examined and compared the physicochemical characteristics of laser-generated ligand-free colloidal AuNPs exposed to steam sterilization and sterile filtration as a function of particle size and mass concentration and obtained physicochemical insight into particle growth processes. These particles exhibit long-term colloidal stability (up to 3 months) derived from electrostatic stabilization without using any ligands or surfactants. We show that particle growth attributed to cluster-based ripening occurs in smaller AuNPs (∼5 nm) following autoclaving, while larger particles (∼10 and ∼30 nm) remain stable. Sterile filtration, as an alternative effective sterilizing approach, has no substantial impact on the colloidal stability of AuNPs, regardless of particle size, although a mass loss of 5-10% is observed. Finally, we evaluated the impact of the sterilization procedures on potential particle functionality in proton therapy, using the formation of reactive oxygen species (ROS) as a readout. In particular, 5 nm AuNPs exhibit a significant loss in activity upon autoclaving, probably dedicated to specific surface area reduction and surface restructuring during particle growth. The filtered analog enhanced the ROS release by up to a factor of ∼2.0, at 30 ppm gold concentration. Our findings highlight the need for carefully adapting the sterilization procedure of ligand-free NPs to the desired biomedical application with special emphasis on particle size and concentration.

in press

The role of Cu:Co composition in bi-metallic Cu-Co/ZnAl₂O₄ catalysts on higher alcohol synthesis (HAS) was investigated at H₂:CO = 4. The addition of Cu strongly facilitated Co reduction upon catalyst activation and suppressed coke deposition during HAS. Formation of predominantly hydrocarbons and higher alcohols was observed on the bi-metallic catalysts. Co/ZnAl₂O₄ produced mainly CH₄ and Cu/ZnAl₂O₄ mainly CH₃OH, while at Cu:Co = 0.6 the best ethanol selectivity of 4.5 % was reached. The microstructure of the spent catalysts confirmed a close interaction of Cu and Co. in press

Many natural proteins contain flexible loops utilizing well-defined complementary surface regions of their interacting partners and usually undergo major structural rearrangements to allow perfect binding. The molecular recognition of such flexible structures is still highly challenging due to the inherent conformational dynamics. Notably, protein-protein interactions are on the other hand characterized by a multivalent display of complementary binding partners to enhance molecular affinity and specificity. Imitating this natural concept, we here report the rational design of advanced multivalent supramolecular tweezers that allow addressing two lysine and arginine clusters on a flexible protein surface loop. The protease Taspase 1, which is involved in cancer development, carries a basic bipartite nuclear localization signal (NLS) and thus interacts with Importin α, a prerequisite for proteolytic activation. Newly established synthesis routes enabled us to covalently fuse several tweezer molecules into multivalent NLS ligands. The resulting bi- up to pentavalent constructs were then systematically compared in comprehensive biochemical assays. In this series, the stepwise increase in valency was robustly reflected by the ligands' gradually enhanced potency to disrupt the interaction of Taspase 1 with Importin α, correlated with both higher binding affinity and inhibition of proteolytic activity.

Nowadays, coatings need to fulfill a variety of requirements such as having excellent mechanical, chemical, and optical properties at low baking temperatures. On a large scale, polyisocyanates, amines or melamines are used as crosslinking agents in the coatings industry. In this work, a new self-crosslinking agent based on a hydroxy functional 6-membered carbonate with high ring tension and thus presumably lower baking temperature was synthesized and the behavior as self-crosslinking agent was compared to the crosslinking agent derived from the commercially available 5-membered glycerol carbonate. The hydroxy functional 6-membered carbonate monomer was synthesized enzymatically under mild reaction conditions from commercially available substances, linked to a hexamethylene diisocyanate trimer and self-polymerized afterward. NMR- and IR-spectroscopy and GC-MS analysis were found to be suitable techniques to characterize monomers and crosslinking agents. DSC measurements were performed to evaluate appropriate reaction parameters for the attachment reaction of the 6-membered cyclic carbonate to the polyisocyanate without ring opening. The progress of self-crosslinking has been followed by characteristic changes in IR spectra as well as time and temperature-dependent changes of storage and loss modulus while oscillating rheological crosslinking. Furthermore, glass transition temperatures of the resulting coating films are determined, and sol gel analysis was performed to estimate the degree of crosslinking. After application on steel, aluminum and glass plates application tests were performed. In addition to excellent mechanical and chemical properties, the coating film showed good adhesion to the surface and was colorless. Combining these properties with relatively low baking temperatures, 6-membered cyclic carbonate crosslinking agents could represent a new technology for the coatings industry.

Es handelt sich hier um Schulhefte des Schülers Helmut Berthold (geb. 1922). Er besuchte in den 1930er und 1940er Jahren die Schule und strebte sein Abitur am Friedrich-Nietzsche-Reformgymnasium (heute Herder-Gymnasium) in Halle (Saale) an. Die Schulhefte bilden heute einen wichtigen Bestandteil des Schularchivs der Integrierten Gesamtschule Am Steintor. Diese Hefte stammen aus verschiedenen Schuljahren und Fächern. Sie enthalten zum Teil Skizzen, Zeichnungen, weitere Erläuterungszettel und Kommentare. Sie geben Hinweise auf Inhalte des Schulunterrichts und Formen der Bildungsarbeit. Zugleich zeigen die Quellen die Vereinnahmung der Schulen für Ziele des Nationalsozialismus. These are exercise books of the pupil Helmut Berthold (born 1922). He attended school in the 1930s and 1940s and aimed for his Abitur at the Friedrich Nietzsche Reform Gymnasium (now Herder Gymnasium) in Halle (Saale). Today, the exercise books form an important part of the school archive of the Integrated Comprehensive School Am Steintor. These notebooks come from various school years and subjects. Some of them contain sketches, drawings, further explanatory notes and comments. They provide information on the content of school lessons and forms of educational work. At the same time, the sources show how the schools were appropriated for the aims of National Socialism., Schularchiv IGS Am Steintor Halle (Saale)

Carbon-based electrocatalysts for oxygen reduction reaction (ORR) are prepared by a direct pathway including a two-step thermal treatment process applied to porous spheres of natural biopolymer blends. Cellulose blends with chitosan are first thermally treated at moderate temperatures (e.g., 200 °C), then pyrolyzed at elevated temperature (800–1000 °C), both steps under a constant nitrogen flow. By blending of cellulose with chitosan, the nitrogen content in the final carbon-based catalyst can be considerably increased. The influence of the composition of the precursor biopolymer blend on the ORR electrocatalytic activity is analyzed in correlation with the elemental composition and other structural features of the catalyst. The polymer blend containing cellulose:chitosan = 75:25, thermally treated 1 h at 200 °C and pyrolyzed 1 h at 800 °C under nitrogen atmosphere, shows the highest electrocatalytic ORR activity. This is attributed to an increased surface area combined with relatively high nitrogen content and a higher pyridinic/pyrrolic species ratio.

Chlorine dioxide (ClO

The development of three dimensional geometries by electrospinning of nonwoven, bioresorbable PDLLA nanoand microfibers is a prerequisite for multimodal growth factor delivery by biohybrids. Electrospinning of 3D tubes is a formidable task since the deposited nanofibers on the rotating mandrel adhere so strongly that newly formed tubes cannot be removed. A specific electrospinning instrument setup with a "removable mandrel sleeve" technique facilitated the reproducible synthesis of tubes for guided bone and future vascular applications. It is shown, that this technique not only allows the preparation of tubes but also of self-supported 3D rings and sandwich panels which can be functionally doped by growth factors such as rhBMP-2 to biohybrids.

In order to reduce the time and cost for near infrared (NIR) model development and maintenance, the transfer of NIR spectra measured on four different portable spectrometers (one master and three target instruments) for predicting the lignin content of pulp wood is investigated in this work. Eighty-two wood samples were prepared by chipping and grinding, and their NIR spectra were recorded with four spectrometers. Calibration models for the determination of lignin in pulp wood have been developed by partial least squares (PLS) regression, while average Mahalanobis distances (AMD) and average differences of spectra (ADS) were used to quantify the spectral differences. Then piecewise direct standardization (PDS) has been applied, and compared to direct standardization (DS), slope/bias correction (SBC) and canonical correlation analysis (CCA). The accuracy of the models has been evaluated by comparing their prediction performance. The results indicated that the prediction performances of the three target instruments are greatly improved by using the three algorithms. The advantage of the PDS algorithm is that fewer samples are required for the transfer sets, which means lower model maintenance cost for practical applications. When it comes to window size setting procedure, it was found that if there are large spectral differences between the master and the target spectrometer, a large window size should be used and if the spectral difference is a significant lateral shift, an asymmetric window with appropriate window size is necessary to ensure a good transfer performance for the PDS algorithm.

The α-Al2O3(0001) surface has been extensively studied because of its significance in both fundamental research and application. Prior work suggests that in ultra-high-vacuum (UHV), in the absence of water, the so-called Al–I termination is thermodynamically favored, while in ambient, in contact with liquid water, a Gibbsite-like layer is created. While the view of the α-Al2O3(0001)/H2O(l) interface appears relatively clear in theory, experimental characterization of this system has resulted in estimates of surface acidity, i.e., isoelectric points, that differ by 4 pH units and surface structure that in some reports has non-hydrogen-bonded surface aluminol (Al–OH) groups and in others does not. In this study, we employed vibrational sum frequency spectroscopy (VSFS) and density functional theory (DFT) simulation to study the surface phonon modes of the differently terminated α-Al2O3(0001) surfaces in both UHV and ambient. We find that, on either water dosing of the Al–I in UHV or heat-induced dehydroxylation of the Gibbsite-like in ambient, the surfaces do not interconvert. This observation offers a new explanation for disagreements in prior work on the α-Al2O3(0001)/liquid water interface─different preparation methods may create surfaces that do not interconvert─and shows that the surface phonon spectral response offers a novel probe of interfacial hydrogen bonding structure.

in press

The analysis of fatty acid methyl esters (FAMEs) is of high relevance for monitoring and control of various industrial processes and biological systems. In this study, a novel, green analytical approach for the determination of 24 FAMEs from aqueous samples is proposed, which is based on a headspace solid-phase microextraction (SPME) arrow followed by gas chromatography coupled to tandem mass spectrometry (GC–MS/MS). The method was substantially accelerated to a run time of 44 min per sample by thorough optimization and automation of the relevant parameters. The limiting parameters, mostly based on expediting equilibrium attainment, were found to be parameters of extraction: material, pH, time, and temperature, which were optimized to divinylbenzene polydimethylsiloxane (DVB-PDMS), pH 2, 20 min, and 70 °C, respectively. The optimization and automation of the method led to low method detection limits (9–437 ng L−1) and high selectivity. Evaluation of the method on real samples was done by analyzing the aqueous phase of a bioreactor, whereby the matrix effect could be greatly reduced due to dilution and headspace sampling. The rapid, sensitive, selective, and matrix-reduced approach is found to be not only a novel method for water analysis but is promising for further applications, e.g., with solid and gaseous samples containing FAMEs. Graphical abstract

CotA laccase was successfully expressed from Pichia pastoris. Magnetic reduced graphene oxide (MRGO) nanocomposite was synthesized and functionalized with iminodiacetic acid (IDA-NH2), and then chelated with Cu2+ for effective immobilization with His-tagged CotA laccase. The Cu2+-chelated MRGO (MRGO-IDA-Cu2+) showed 175 mg/g-support adsorption capacity. The immobilization of CotA laccase with MRGO-IDA-Cu2+ nano-hybrid composite was confirmed by Raman spectroscopy, Thermal Gravimetric Analysis, and X-ray diffraction. The use of nano-hybrid MRGO-IDA-Cu2+ composite to improve heavy oil recovery was investigated. The findings revealed that the interfacial tension between oil and water was reduced to ~ 90% of its original value, and the wettability was changed from the oil-wet state [θ = ∼ 115.2 − 124.5°] to the water-wet state [θ = ∼ 8.9 − 30.1°]. The increase of immobilized CotA laccase concentration and the ratio of nano-hybrid MRGO-IDA-Cu2+ composite decreases the value of interfacial tension (IFT) and contact angle (CA). The core-flooding studies revealed that the oil recovery process of 0.3 wt% nano-hybrid MRGO-IDA-Cu2+ composite was enhanced by 82.8%. Graphical Abstract

In this eye-tracking experiment, we compared instructional videos with static signals, dynamic signals and no signaling in a within-subject design. We tracked eye movements from 28 undergraduate chemistry students while they were watching instructional videos about reaction mechanisms in the different signaling conditions. Further, we assessed students' cognitive load, as well as retention performance. We employed a Latin square design to control for sequencing and content effects of the instructional videos. Our data showed that dynamic signals helped students to better focus their attention to the relevant features of the representations virtually across the entire time of the video presentation. Furthermore, dynamic signals increased retention performance while they decreased extraneous cognitive load. Overall, our findings show the crucial role of pairing the signaling principle with the temporal contiguity principle in instructional videos to help students navigate through complex symbolic representations and improve their learning success.

The uptake of fluorescently labeled ultrasmall gold nanoparticles (2 nm) by Gram-negative Escherichia coli bacteria occurs within 1–3 hours. This was demonstrated by confocal laser scanning microscopy (CLSM), structured illumination microscopy (SIM), stochastic optical reconstruction microscopy (STORM), and flow cytometry. For imaging, eGFP-expressing and DsRed2-expressing E. coli strains were used in addition to non-fluorescing E. coli strains. Gold nanoparticles were labeled with fluoresceine (FITC), Cy3, and AF647, respectively. Importantly, gold nanoparticles showed no toxicity to the bacteria, indicating a non-lethal nature of the uptake, that is, not related to cell injury. OA Förderung 2022

The achievable grinding fineness of spiral jet mills does not only depend on the comminution efficiency in the region of the nozzle jets but is also significantly affected by the separation efficiency in the region of the product outlet. Therefore, the aim of this study is to investigate the influences of the product outlet diameter and different particle trap rings on the flow conditions and the grinding performance, optimizing the classifying efficiency of spiral jet mills. The velocity fields analyzed by particle image velocimetry and the experimental grinding results show that the classification process can be optimized by both reducing the product outlet diameter and installing a particle trap ring. in press

Pronounced magnetocaloric effects are typically observed in materials that often contain expensive and rare elements and are therefore costly to mass produce. However, they can rather be exploited on a small scale for miniaturized devices such as magnetic micro coolers, thermal sensors, and magnetic micropumps. Herein, a method is developed to generate magnetocaloric microstructures from an equiatomic iron–rhodium (FeRh) bulk target through a stepwise process. First, paramagnetic near-to-equiatomic solid-solution FeRh nanoparticles (NPs) are generated through picosecond (ps)-pulsed laser ablation in ethanol, which are then transformed into a printable ink and patterned using a continuous wave laser. Laser patterning not only leads to sintering of the NP ink but also triggers the phase transformation of the initial γ- to B2-FeRh. At a laser fluence of 246 J cm−², a partial (52%) phase transformation from γ- to B2-FeRh is obtained, resulting in a magnetization increase of 35 Am² kg−¹ across the antiferromagnetic to ferromagnetic phase transition. This represents a ca. sixfold enhancement compared to previous furnace-annealed FeRh ink. Finally, herein, the ability is demonstrated to create FeRh 2D structures with different geometries using laser sintering of magnetocaloric inks, which offers advantages such as micrometric spatial resolution, in situ annealing, and structure design flexibility. in press

The role of \(\beta\)-CoOOH crystallographic orientations in catalytic activity for the oxygen evolution reaction (OER) remains elusive. We combine correlative electron backscatter diffraction/scanning electrochemical cell microscopy with X-ray photoelectron spectroscopy, transmission electron microscopy, and atom probe tomography to establish the structure–activity relationships of various faceted \(\beta\)-CoOOH formed on a Co microelectrode under OER conditions. We reveal that \(\approx\)6 nm \(\beta\)-CoOOH(01\(\overline{1}\)0, grown on [\(\overline{1}\)2\(\overline{1}\)0]-oriented Co, exhibits higher OER activity than \(\approx\)3 nm \(\beta\)-CoOOH(10\(\overline{1}\)3) or \(\approx\)6 nm \(\beta\)-CoOOH(0006) formed on [02\(\overline{2}\)1]- and [0001]-oriented Co, respectively. This arises from higher amounts of incorporated hydroxyl ions and more easily reducible Co\(^{III}\)−O sites present in \(\beta\)-CoOOH(01\(\overline{1}\)0) than those in the latter two oxyhydroxide facets. Our correlative multimodal approach shows great promise in linking local activity with atomic-scale details of structure, thickness and composition of active species, which opens opportunities to design pre-catalysts with preferred defects that promote the formation of the most active OER species.

Platinum is the best electrocatalyst for the hydrogen evolution reaction (HER). Here, we demonstrate that by contact electrification of Pt nanoparticle satellites on a gold or silver core, the Fermi level of Pt can be tuned. The electronic properties of Pt in such hybrid nanocatalysts were experimentally characterized by X-ray photoelectron spectroscopy (XPS) and surface-enhanced Raman scattering (SERS) with the probe molecule 2,6-dimethyl phenyl isocyanide (2,6-DMPI). Our experimental findings are corroborated by a hybridization model and density functional theory (DFT) calculations. Finally, we demonstrate that tuning of the Fermi level of Pt results in reduced or increased overpotentials in water splitting.

As a rule, helical structures at the molecular level are formed by non-planar units. This makes the design of helices, starting from planar building blocks via self-assembly, even more fascinating. Until now, however, this has only been achieved in rare cases, where hydrogen and halogen bonds were involved. Here, we show that the carbonyl-tellurium interaction motif is suitable to assemble even small planar units into helical structures in solid phase. We found two different types of helices: both single and double helices, depending on the substitution pattern. In the double helix, the strands are connected by additional Te⋅⋅⋅Te chalcogen bonds. In the case of the single helix, a spontaneous enantiomeric resolution occurs in the crystal. This underlines the potential of the carbonyl-tellurium chalcogen bond to generate complex three-dimensional patterns. in press