Exploring the oxidation behavior of undiluted and diluted iron particles for energy storage: Mössbauer spectroscopic analysis and kinetic modeling.

Iron is an abundant and non-toxic element that holds great potential as energy carrier for large-scale and long-term energy storage. While from a general viewpoint iron oxidation is well-known, the detailed kinetics of oxidation for micrometer sized particles are missing, but required to enable large-scale utilization for energy production. In this work, iron particles are subjected to temperature-programmed oxidation. By dilution with boron nitride a sintering of the particles is prevented enabling to follow single particle effects. The mass fractions of iron and its oxides are determined for different oxidation times using Mössbauer spectroscopy. On the basis of the extracted phase compositions obtained at different times and temperatures (600-700 °C), it can be concluded that also for particles the oxidation follows a parabolic rate law. The parabolic rate constants are determined in this transition region. Knowledge of the particle size distribution and its consideration in modeling the oxidation kinetics of iron powder has proven to be crucial.

Increasing Accessible Active Site Density of Non-Precious Metal Oxygen Reduction Reaction Catalysts through Ionic Liquid Modification.

Non-precious metal catalysts show great promise to replace the state-of-the-art Pt-based catalysts for catalyzing the oxygen reduction reaction (ORR), while their catalytic activity still needs to be greatly improved before their broad-based application. Here, we report a facile approach to improving the performance of zeolitic imidazolate framework-derived carbon (ZDC) toward the ORR by incorporating a small amount of ionic liquid (IL). The IL would preferentially fill the micropores of ZDC and greatly enhance the utilization of the active sites within the micropores, which are initially not accessible due to insufficient surface wetting. It is also disclosed that the ORR activity in terms of kinetic current at 0.85 V depends on the loading amount of the IL, and the maximum activity is obtained at a mass ratio of IL to ZDC at 1.2. The optimum stems from the counterbalance between the enhanced utilization of the active sites within the micropores and the retarded diffusion of the reactants within the IL phase due to its high viscosity.

MXene Aerogel Derived Ultra-Active Vanadia Catalyst for Selective Conversion of Sustainable Alcohols to Base Chemicals.

Selective oxidation reactions are an important class of the current chemical industry and will be highly important for future sustainable chemical production. Especially, the selective oxidation of primary alcohols is expected to be of high future interest, as alcohols can be obtained on technical scales from biomass fermentation. The oxidation of primary alcohols produces aldehydes, which are important intermediates. While selective methanol oxidation is industrially established, the commercial catalyst suffers from deactivation. Ethanol selective oxidation is not commercialized but would give access to sustainable acetaldehyde production when using renewable ethanol. In this work, it is shown that employing 2D MXenes as building blocks allows one to design a nanostructured oxide catalyst composed of mixed valence vanadium oxides, which outperforms on both reactions known materials by nearly an order of magnitude in activity, while showing high selectivity and stability. The study shows that the synthesis route employing 2D materials is key to obtain these attractive catalysts. V4C3Tx MXene structured as an aerogel precursor needs to be employed and mildly oxidized in an alcohol and oxygen atmosphere to result in the aspired nanostructured catalyst composed of mixed valence VO2, V6O13, and V3O7. Very likely, the bulk stable reduced valence state of the material together coupled with the nanorod arrangement allows for unprecedented oxygen mobility as well as active sites and results in an ultra-active catalyst.

Effective treatment of highest instability in a subacute fragility fracture of the pelvis (FFP IV) using a cement augmented transsacral screw only.

The highest instability in fragility fractures of the pelvis (FFP) is noted in presence of H-, U-type sacral fractures. Suggested surgical treatment options include uni- or bilateral sacroiliac or transsacral screw fixation at different levels or in combination, as well as lumbopelvic and bilateral triangular lumbopelvic stabilization. However, distinct treatment recommendations for this subset of injuries are scarce. We present a case sustaining rapid FFP crescendo instability following initial conservative treatment of a FFP type II injury resulting in a U-type spinopelvic dissociation. Fixation using one percutaneous cement augmented transsacral S1 screw resulted in perpetual clinical improvements in pain and mobility in presence of radiologic fracture consolidation.

Scalable Microreactor Concept for the Continuous Kolbe Electrolysis of Carboxylic Acids Using Aqueous Electrolyte.

The Kolbe electrolysis is a promising reaction to combine the usage of electrons as reagents and the application of renewable generated carboxylic acids as raw materials producing value added chemicals. Within this study, the electrolysis was conducted in a specially developed concept electrochemical microreactor and draws the particular attention to continuous operation and reuse of the aqueous electrolyte as well as of the dissolved unreacted feedstock. The electrolysis was conducted in alkaline aqueous solution using n-octanoic acid as model substance. Platinized titanium as anode material in an undivided cell setup was shown to give Kolbe selectivity above 90 %. During the technically relevant conditions of current densities up to 0.6 A cm-2 and overall electrolysis times of up to 3 h, a high electrode stability was observed. Finally, a proof-of-concept continuous operation and the numbering up potential of the ECMR could be demonstrated.

Receptor Activator of NF-κB (RANK) Confers Resistance to Chemotherapy in AML and Associates with Dismal Disease Course.

Although treatment options of acute myeloid leukemia (AML) have improved over the recent years, prognosis remains poor. Better understanding of the molecular mechanisms influencing and predicting treatment efficacy may improve disease control and outcome. Here we studied the expression, prognostic relevance and functional role of the tumor necrosis factor receptor (TNFR) family member Receptor Activator of Nuclear Factor (NF)-κB (RANK) in AML. We conducted an experimental ex vivo study using leukemic cells of 54 AML patients. Substantial surface expression of RANK was detected on primary AML cells in 35% of the analyzed patients. We further found that RANK signaling induced the release of cytokines acting as growth and survival factors for the leukemic cells and mediated resistance of AML cells to treatment with doxorubicin and cytarabine, the most commonly used cytostatic compounds in AML treatment. In line, RANK expression correlated with a dismal disease course as revealed by reduced overall survival. Together, our results show that RANK plays a yet unrecognized role in AML pathophysiology and resistance to treatment, and identify RANK as "functional" prognostic marker in AML. Therapeutic modulation of RANK holds promise to improve treatment response in AML patients.

Eliminating viscosity bias in lateral flow tests.

Despite the widespread application of point-of-care lateral flow tests, the viscosity dependence of these assay results remains a significant challenge. Here, we employ centrifugal microfluidic flow control through the nitrocellulose membrane of the strip to eliminate the viscosity bias. The key feature is the balancing of the sample flow into the cassette of the lateral flow test with the air flow out of the cassette. A viscosity-independent flow rate of 3.01 ± 0.18 µl/min (±6%) is demonstrated for samples with viscosities ranging from 1.1 mPas to 24 mPas, a factor greater than 20. In a model human IgG lateral flow assay, signal-intensity shifts caused by varying the sample viscosity from 1.1 mPas to 2.3 mPas could be reduced by more than 84%.

Avoiding Pitfalls in Comparison of Activity and Selectivity of Solid Catalysts for Electrochemical HMF Oxidation.

Electrocatalytic oxidation of 5-hydroxymethylfurfural (HMF) offers a renewable approach to produce the value-added platform chemical 2,5-furandicarboxylic acid (FDCA). The key for the economic viability of this approach is to develop active and selective electrocatalysts. Nevertheless, a reliable catalyst evaluation protocol is still missing, leading to elusive conclusions on criteria for a high-performing catalyst. Herein, we demonstrate that besides the catalyst identity, secondary parameters such as materials of conductive substrates for the working electrode, concentration of the supporting electrolyte, and electrolyzer configurations have profound impact on the catalyst performance and thus need to be optimized before assessing the true activity of a catalyst. Moreover, we highlight the importance of those secondary parameters in suppressing side reactions, which has long been overlooked. The protocol is validated by evaluating the performance of free-standing Cu-foam, and CuCoO modified with NaPO2 H2 and Ni, which were immobilized on boron-doped diamond (BDD) electrodes. Recommended practices and figure of merits in carefully evaluating the catalyst performance are proposed.

An Fc-Optimized CD133 Antibody for Induction of NK Cell Reactivity against B Cell Acute Lymphoblastic Leukemia.

In recent decades, antibody-dependent cellular cytotoxicity (ADCC)-inducing monoclonal antibodies (mAbs) have revolutionized cancer immunotherapy, and Fc engineering strategies have been utilized to further improve efficacy. A promising option is to enhance the affinity of an antibody's Fc-part to the Fc-receptor CD16 by altering the amino acid sequence. Herein, we characterized an S239D/I332E-modified CD133 mAb termed 293C3-SDIE for treatment of B cell acute lymphoblastic leukemia (B-ALL). Flow cytometric analysis revealed CD133 expression on B-ALL cell lines and leukemic cells of 50% (14 of 28) B-ALL patients. 293C3-SDIE potently induced NK cell reactivity against the B-ALL cell lines SEM and RS4;11, as well as leukemic cells of B-ALL patients in a target antigen-dependent manner, as revealed by analysis of NK cell activation, degranulation, and cytotoxicity. Of note, CD133 expression did not correlate with BCR-ABL, CD19, CD20, or CD22, which are presently used as therapeutic targets in B-ALL, which revealed CD133 as an independent target for B-ALL treatment. Increased CD133 expression was also observed in MLL-AF4-rearranged B-ALL, indicating that 293C3-SDIE may constitute a particularly suitable treatment option in this hard-to-treat subpopulation. Taken together, our results identify 293C3-SDIE as a promising therapeutic agent for the treatment of B-ALL.

Nanoscale Hybrid Amorphous/Graphitic Carbon as Key Towards Next-Generation Carbon-Based Oxidative Dehydrogenation Catalysts.

A new strategy affords "non-nano" carbon materials as dehydrogenation catalysts that perform similarly to nanocarbons. Polymer-based carbon precursors that combine a soft-template approach with ion adsorption and catalytic graphitization are key to this synthesis strategy, thus offering control over macroscopic shape, texture, and crystallinity and resulting in a hybrid amorphous/graphitic carbon after pyrolysis. From this intermediate the active carbon catalyst is prepared by removing the amorphous parts of the hybrid carbon materials via selective oxidation. The oxidative dehydrogenation of ethanol was chosen as test reaction, which shows that fine-tuning the synthesis of the new carbon catalysts allows to obtain a catalytic material with an attractive high selectivity (82 %) similar to a carbon nanotube reference, while achieving 10 times higher space-time yields at 330 °C. This new class of carbon materials is accessible via a technically scalable, reproducible synthetic pathway and exhibits spherical particles with diameters around 100 µm, allowing unproblematic handling similar to classic non-nano catalysts.

Probing CO2 Reduction Pathways for Copper Catalysis Using an Ionic Liquid as a Chemical Trapping Agent.

The key to fully leveraging the potential of the electrochemical CO2 reduction reaction (CO2RR) to achieve a sustainable solar-power-based economy is the development of high-performance electrocatalysts. The development process relies heavily on trial and error methods due to poor mechanistic understanding of the reaction. Demonstrated here is that ionic liquids (ILs) can be employed as a chemical trapping agent to probe CO2RR mechanistic pathways. This method is implemented by introducing a small amount of an IL ([BMIm][NTf2 ]) to a copper foam catalyst, on which a wide range of CO2RR products, including formate, CO, alcohols, and hydrocarbons, can be produced. The IL can selectively suppress the formation of ethylene, ethanol and n-propanol while having little impact on others. Thus, reaction networks leading to various products can be disentangled. The results shed new light on the mechanistic understanding of the CO2RR, and provide guidelines for modulating the CO2RR properties. Chemical trapping using an IL adds to the toolbox to deduce the mechanistic understanding of electrocatalysis and could be applied to other reactions as well.

Porous graphite as stationary phase for the chromatographic separation of polymer additives - determination of adsorption capability by Raman spectroscopy and physisorption.

Additives are added to polymers in small concentration to achieve desired application properties widely used to tailor the properties. The rapid diversification of their molecular structures, with often only minute differences, necessitates the development of adequate chromatographic techniques. While modified silica so far is the workhorse as stationary phase we have probed the potential of porous graphitic carbon (HypercarbTM) for this purpose. The results show that the multitude of physicochemical interactions between analyte molecules and the graphitic surface enables separations of polyolefin stabilizers with unprecedented selectivity. To support the chromatographic results the adsorption capability of HypercarbTM for selected antioxidants and UV absorbers has been determined by Raman spectroscopy and argon physisorption measurements. The shift of the Graphite-band in the Raman spectra of HypercarbTM upon infusion with additives correlates with the changes in the Adsorption Potential Distributions. The results of argon physisorption measurements go hand in hand with the chronology of desorption of the additives in liquid chromatography experiments. The elution sequence can be explained by van der Waals or London forces, π-π-interactions and electron lone pair donor-acceptor interactions between the graphite surface and analyte functional groups.

Methanol conversion on borocarbonitride catalysts: Identification and quantification of active sites.

Borocarbonitrides (BCNs) have emerged as highly selective catalysts for the oxidative dehydrogenation (ODH) reaction. However, there is a lack of in-depth understanding of the catalytic mechanism over BCN catalysts due to the complexity of the surface oxygen functional groups. Here, BCN nanotubes with multiple active sites are synthesized for oxygen-assisted methanol conversion reaction. The catalyst shows a notable activity improvement for methanol conversion (29%) with excellent selectivity to formaldehyde (54%). Kinetic measurements indicate that carboxylic acid groups on BCN are responsible for the formation of dimethyl ether, while the redox catalysis to formaldehyde occurs on both ketonic carbonyl and boron hydroxyl (B─OH) sites. The ODH reaction pathway on the B─OH site is further revealed by in situ infrared, x-ray absorption spectra, and density functional theory. The present work provides physical-chemical insights into the functional mechanism of BCN catalysts, paving the way for further development of the underexplored nonmetallic catalytic systems.

Revision of a blade cut-out in PFN-A fixation: Blade exchange, cement augmentation and a cement plug as a successful salvage option.

A potential and feared complication of proximal femur nails with cephalomedullary fixation is migration of the cephalomedullary screw or blade (cut-out or cut-through). In patients not suitable (e.g. low demand, comorbidities) for conversion to total hip arthroplasty blade exchange with cement augmentation may be an option. This article describes the first successful clinical use of a salvage procedure of a previously published technique, which allows the surgeon to avoid intraarticular cement leakage by using a standard cement plug to close the defect in the femoral head.

Quantifying the asymmetries of the human face.

Asymmetries in the human face are quite common but do not get enough attention with regard to forensics and criminalistics. A face with asymmetries has a higher recognition value than a face without such morphological deviations. Therefore it is useful to determine the frequency of facial asymmetries to be able to evaluate the individual asymmetries focusing their rarity. This can be used primarily in forensic anthropology, particularly in the identification of persons. This aspect is the basis of this study. Therefore several structures in the faces of 130 volunteers (65 male, 65 female) from southern Germany were examined for asymmetries based on 3D laser scans. The study showed that asymmetries frequently occur in the eyes, the mouth and the ears. Rarer are asymmetries in the bridge of the nose and the shape of the chin. There is also considerable variation in the degree of asymmetry. Basically it can be said that small-scale structures, such as those in the eye area, have less pronounced asymmetries than large-scale structures such as the nose, mouth, chin and ear.

Paper-Based Microfluidics for Electrochemical Applications.

Paper-based microfluidics is characteristic of fluid transportation through spontaneous capillary action of paper and has exhibited great promise for a variety of applications especially for sensing. Furthermore, paper-based microfluidics enables the design of miniaturized electrochemical devices to be applied in the energy sector, which is especially attractive for the rapid growing market of small size disposable electronics. This review gives a brief summary on the basics of paper chemistry and capillary-driven microfluidic behavior, and highlights recent advances of paper-based microfluidics in developing electrochemical sensing devices and miniaturized energy storage/conversion devices. Their structural features, working principles and exemplary applications are comprehensively elaborated and discussed. Additionally, this review also points out the existing challenges and future opportunities of paper-based microfluidic electronics.

Induction of NK Cell Reactivity against B-Cell Acute Lymphoblastic Leukemia by an Fc-Optimized FLT3 Antibody.

Antibody-dependent cellular cytotoxicity (ADCC) is a major mechanism by which antitumor antibodies mediate therapeutic efficacy. At present, we evaluate an Fc-optimized (amino acid substitutions S239D/I332E) FLT3 antibody termed 4G8-SDIEM (FLYSYN) in patients with acute myeloid leukemia (NCT02789254). Here we studied the possibility to induce NK cell ADCC against B-cell acute lymphoblastic leukemia (B-ALL) by Fc-optimized FLT3 antibody treatment. Flow cytometric analysis confirmed that FLT3 is widely expressed on B-ALL cell lines and leukemic cells of B-ALL patients. FLT3 expression did not correlate with that of CD20, which is targeted by Rituximab, a therapeutic monoclonal antibody (mAb) employed in B-ALL treatment regimens. Our FLT3 mAb with enhanced affinity to the Fc receptor CD16a termed 4G8-SDIE potently induced NK cell reactivity against FLT3-transfectants, the B-ALL cell line SEM and primary leukemic cells of adult B-ALL patients in a target-antigen dependent manner as revealed by analyses of NK cell activation and degranulation. This was mirrored by potent 4G8-SDIE mediated NK cell ADCC in experiments with FLT3-transfectants, the cell line SEM and primary cells as target cells. Taken together, the findings presented in this study provide evidence that 4G8-SDIE may be a promising agent for the treatment of B-ALL, particularly in CD20-negative cases.

Activated Carbon in the Third Dimension-3D Printing of a Tuned Porous Carbon.

A method for obtaining hierarchically structured porous carbons, employing 3D printing to control the structure down to the lower µm scale, is presented. To successfully 3D print a polymer precursor and transfer it to a highly stable and structurally conformal carbon material, stereolithography 3D printing and photoinduced copolymerization of pentaerythritol tetraacrylate and divinylbenzene are employed. Mechanically stable structures result and a resolution of ≈15 µm is demonstrated. This approach can be combined with liquid porogen templating to control the amount and size (up to ≈100 nm) of transport pores in the final carbonaceous material. Additional CO2 activation enables high surface area materials (up to 2200 m2 g-1) that show the 3D printing controlled µm structure and nm sized transport pores. This unique flexibility holds promise for the identification of optimal carbonaceous structures for energy application, catalysis, and adsorption.