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Magnesium as biodegradable biomaterial could serve as bone augmentation material in implant dentistry. The knowledge about the predictability of the biodegradation process is essential as this process needs to go hand in hand with the formation of new bone to gradually replace the augmentation material. Therefore, this work aimed to assess if the electrochemistry (EC) measurements of the corrosion process correlate with the surface features at various time points during the surface degradation, in order to describe the degradation process of Mg and Mg alloys more reliably, under the assumption that differences in EC behavior can be detected and related to specific patterns on the surface. In this test setup, a special optical chamber was used for electrochemical measurements on Mg and Mg-alloys (Mg2Ag, Mg4Ag, and Mg6Ag). Specimens were investigated using different circulating cell culture solutions as electrolytes, these were minimum essential medium (MEM), Hank's Balanced Salt Solution (HBSS), and MEM+ (MEM with added sodium hydrogen carbonate) at 37 °C. Open circuit potential measurements (OCP) over 30 min followed by cyclic polarization were performed. The electrochemistry data, including OCP, exchange current density and corrosion potential, were compared with visible changes at the surface during these treatments over time. The results show that the addition of silver (Ag) leads to a “standardization” of the degradation regardless of the selected test medium. It is currently difficult to correlate the visible microscopic changes with the data taken from the measurements. Therefore, further investigations are necessary., Graphical abstract Image 1, Highlights • MgXAg alloys were investigated electrochemically in MEM, HBSS and MEM+ at 37℃ in circulated electrolyte. • A correlation between optical appearance and electrochemical data was performed. • Visible high activity on the surface corresponded with high electrochemical activity.

International audience; Hydroxamic acids are metal-chelating compounds that show important biological activity including anti-tumor effects. We have recently engineered the transketolase from Geobacillus stearothermopilus (TKgst) to convert benzaldehyde as a non-natural acceptor substrate. Realizing the structural and electronic similarity to nitrosobenzene, we studied the TK-catalyzed conversion of nitrosoarenes to yield N-arylated hydroxamic acids. Here we demonstrate that wild-type and variants of this versatile TKgst enzyme indeed induce the rapid biocatalytic conversion of variously p-, m- and o-substituted nitrosoarenes to produce a variety of corresponding N-aryl hydroxamic acids via creation of a carbon-nitrogen instead of a carbon-carbon bond. Further structural modifications can be introduced by varying the donor component, such as hydroxypyruvate or pyruvate.

The present review reports on the preparation and atomic‐scale characterization of the thinnest possible films of the glass‐forming materials silica and germania. To this end state‐of‐the‐art surface science techniques, in particular scanning probe microscopy, and density functional theory calculations have been employed. The investigated films range from monolayer to bilayer coverage where both, the crystalline and the amorphous films, contain characteristic XO4 (X=Si,Ge) building blocks. A side‐by‐side comparison of silica and germania monolayer, zigzag phase and bilayer films supported on Mo(112), Ru(0001), Pt(111), and Au(111) leads to a more general comprehension of the network structure of glass former materials. This allows us to understand the crucial role of the metal support for the pathway from crystalline to amorphous ultrathin film growth., Ultrathin films: Comparison of silica and germania thin films to understand the crucial role of the metal support for the pathway from crystalline to amorphous structures.

Defined sialoglycoconjugates are important molecular probes for studying the role of sialylated glycans in biological systems. We show that the α2,3‐sialyltransferase from Photobacterium phosphoreum JT‐ISH‐467 (2,3SiaTpph) tolerates a very broad substrate scope for modifications in the sialic acid part, including bulky amide variation, C5/C9 substitution, and C5 stereoinversion. To reduce the enzyme's hydrolytic activity, which erodes the product yield, an extensive structure‐guided mutagenesis study identified three variants that show up to five times higher catalytic efficiency for sialyltransfer, up to ten times lower efficiency for substrate hydrolysis, and drastically reduced product hydrolysis. Variant 2,3SiaTpph (A151D) displayed the best performance overall in the synthesis of the GM3 trisaccharide (α2,3‐Neu5Ac‐Lac) from lactose in a one‐pot, two‐enzyme cascade. Our study demonstrates that several complementary solutions can be found to suppress the common problem of undesired hydrolysis activity of microbial GT80 sialyltransferases. The new enzymes are powerful catalysts for the synthesis of a wide variety of complex natural and new‐to‐nature sialoconjugates for biological studies., Be tolerant: An engineered sialyltransferase has exceptional tolerance for a wide variety of substrate modifications, both in glycosyl donor and acceptor moieties. Its undesired promiscuous hydrolytic activity was significantly reduced through deep mutational scanning around the active site. The resultant enzyme is a powerful catalyst for the one‐pot cascade synthesis of novel molecular probes for biological studies.

Rotenone ([2R-(2α,6aα,12aα)]-1,2,12,12a-tetrahydro-8,9-dimethoxy-2-(1-methylethenyl)-[1]benzopyran[3,4-b]furo [2,3-h][1]benzopyran-6(6aH)-one) is a naturally occurring compound derived from the roots and stems of Derris, Tephrosia, Lonchocarpus and Mundulea plant species. Since its discovery at the end of the 19th century, rotenone has been widely used as a pesticide for controlling insects, ticks and lice, and as a piscicide for management of nuisance fish in lakes and reservoirs. In 2000, Betarbet et al. reproduced most of the behavioural, biochemical and pathological features of Parkinson's disease (PD) in rotenone-treated rats. Since that time, rotenone has received much attention as it would be one of the environmental neurotoxins implicated in etiopathogenesis of PD. Moreover, it represents a common experimental model to investigate the underlying mechanisms leading to PD and evaluate the new potential therapies for the disease. In the current general review, we aimed to address recent advances in the hazards of the environmental applications of rotenone and discuss the updates on the rotenone model of PD and whether it is implicated in the etiopathogenesis of the disease.

In mass spectrometry-based proteomics, heavy internal standards are used to validate target peptide detections and to calibrate peptide quantification. Here we report light contamination present in heavy labelled synthetic peptides of high isotopic enrichment. Application of such peptides as assay-internal standards potentially compromises the detection and quantification especially of low abundant cellular peptides. Therefore, it is important to adopt guidelines to prevent false-positive identifications of endogenous light peptides as well as errors in their quantification from biological samples.

A new two‐dimensional (2D) germanium dioxide film has been prepared. The film consists of interconnected germania tetrahedral units forming a bilayer structure, weakly coupled to the supporting Pt(111) metal‐substrate. Density functional theory calculations predict a stable structure of 558‐membered rings for germania films, while for silica films 6‐membered rings are preferred. By varying the preparation conditions the degree of order in the germania films is tuned. Crystalline, intermediate ordered and purely amorphous film structures are resolved by analysing scanning tunnelling microscopy images.

Glycoside hydrolases, particularly cellulases, xylanases and mannanases, are essential for the depolymerisation of lignocellulosic substrates in various industrial bio-processes. In the present study, a novel glycoside hydrolase from Paenibacillus mucilaginosus (PmGH) was expressed in E. coli, purified and characterised. Functional analysis indicated that PmGH is a 130 kDa thermophilic multi-modular and multi-functional enzyme, comprising a GH5, a GH6 and two CBM3 domains and exhibiting cellulase, mannanase and xylanase activities. The enzyme displayed optimum hydrolytic activities at pH 6 and 60 °C and moderate thermostability. Homology modelling of the full-length protein highlighted the structural and functional novelty of native PmGH, with no close structural homologs identified. However, homology modelling of the individual GH5, GH6 and the two CBM3 domains yielded excellent models based on related structures from the Protein Data Bank. The catalytic GH5 and GH6 domains displayed a (β/α)8 and a distorted seven stranded (β/α) fold, respectively. The distinct homology at the domain level but low homology of the full-length protein suggests that this protein evolved by exogenous gene acquisition and recombination.

The search for osteoinductive as well as osteoconductive materials has led to the novel idea of using titanium in bone augmentations of the alveolar crest. Due to its excellent biocompatibility and favorable osteogenic properties, highly porous TiO2 granules has been proposed as a promising material for non-resorbable synthetic bone grafts in the restoration of large bone defects, and for bone augmentation in dental applications. Objectives The aim of this study was to investigate the osteoconductive properties and biological performance of porous titanium granules used in osseous defects adjacent to the maxillary sinus in sheep. The experimental animal study involved 15 yearling sheep with a focus on the osteogenic potential of porous titanium used for subantral augmentation. Material and methods Calibrated defects were prepared in the subantral region of sheep. The defects were randomized into tests and control group. The test defects were grafted with porous titanium granules (PTG), whereas control defects were left empty (sham). Defects were left for healing for 30, 60, and 90 days. After healing, the grafted areas were removed and finally osteoconductivity was analyzed by an orthopantograph (OPG} and histology. Results Significantly more new bone formed in PTG grafted defects compared with sham. The control group showed significantly less expression of key inflammation cells, but with no significant difference in key inflammation cells compared with the experimental groups. Conclusion Porous titanium can offer as an effective alternative to calcium phosphate and bone collagen-based materials used for subantral augmentation of the maxillary bone in cases of dental implantation.

International audience; We propose an ecofriendly, efficient, stereoselective procedure for the two-carbon elongation of nonphosphorylated aldoses (C4–C6) to the corresponding Cn+2 ketoses (C6–C8) in one step, using hydroxypyruvate (HPA) as a ketol donor substrate and an evolved thermostable transketolase from Geobacillus stearothermophilus (TKgst) as a biocatalyst. Simultaneous site saturation mutagenesis (SSM) at two or three key positions in the TKgst active site yielded efficient variants, L382F/F435Y, R521Y/S385/H462N, and R521V/S385D/H462S, with increased activity compared to wild-type TKgst for conversion of two tetroses (d-threose, l-erythrose), two pentoses (d-xylose, d-ribose), and two hexoses (d-allose, d-glucose), respectively. These six Cn aldoses as acceptor and HPA as donor substrates were transformed by the TKgst variants at 60 °C with practically complete conversion. The corresponding Cn+2 ketoses, including two hexuloses (d-tagatose, l-psicose), two heptuloses (d-altro-heptulose, d-ido-heptulose), and two octuloses (d-glycero-d-ido-octulose, d-glycero-d-altro-octulose) are naturally rare compounds with important biological functions, which were obtained with high diastereoselectivity.

Cemented carbides prepared from mixes of WC and stainless steel powder have been proposed as possible alternatives to WC-Co. However, phase formation in such systems is not well described in the literature, in particular with regard to the possible formation of Cr-carbides. In this work, cemented carbides have been prepared from batches of coarse WC powder and 20 wt% AISI 360 L stainless steel powder, considering different carbon black additions to vary the final carbon contents to 4.9, 5.64, 5.75 wt% C. Both experimental results and thermodynamic calculations show that no classical two phase area – containing only WC and metallic binder- can be expected in these alloys. (Cr, Fe)-carbides are observed at all carbon contents in equilibrium with eta phases and binder, and at the highest carbon content also with graphite. As a consequence of the formation of (Cr, Fe)-carbides the amount of metallic binder decreases significantly, and the composition of the binder changes drastically. The binder phase in the sintered materials constitute an Fe-15Ni alloy with about 5 wt% Cr and 2 wt% W in solid solution, which is more similar to a maraging steel rather than a stainless steel. Both thermodynamic calculations and experimental results confirm that the maximum amount of Cr that can be retained in the metallic binder is around 5 wt% Cr which implies that, after sintering, the stainless steel properties will be lost.

Purpose To characterize retinal microaneurysms (MAs) in patients with diabetes using adaptive optics optical coherence tomography (AOOCT) and compare details found in AOOCT with those found in commercially available retinal imaging techniques. Methods Patients with diabetes and MA in the macular area were included in this pilot study. The area of interest, identified in standard fluorescein angiography, was imaged using an AO fundus camera and AOOCT. Microaneurysms were characterized in AOOCT (visibility, reflectivity, feeding/draining vessels, and intraretinal location) and compared with findings in AO fundus camera, OCT angiography, and fluorescein angiography. Results Fifty-three MAs were imaged in 15 eyes of 10 patients. Feeding and/or draining vessels from both capillary plexus could be identified in 34 MAs in AOOCT images. Of 45 MAs imaged with OCT angiography, 18 (40%) were visible in the superior plexus, 12 (27%) in the deep capillary plexus, and 15 MAs (33%) could not be identified at all. Intraluminal hyperreflectivity, commonly seen in AO fundus camera, corresponded only in 8 of 27 cases (30%) to intraluminal densities seen in AOOCT. Conclusion Adaptive optics OCT imaging revealed that MAs located in the inner nuclear layer were connected to the intermediate and/or deep capillary plexus. Intraluminal hyperreflectivity seen on AO fundus camera images originated from a strong reflection from the vessel wall and only in a third of the cases from intraluminal clots. Currently, AOOCT is the most expedient in vivo imaging method to capture morphologic details of retinal microvasculature in 3D and in the context of the surrounding retinal anatomy.

The optimized superconducting stellarator device Wendelstein 7-X (with major radius , minor radius , and plasma volume) restarted operation after the assembly of a graphite heat shield and 10 inertially cooled island divertor modules. This paper reports on the results from the first high-performance plasma operation. Glow discharge conditioning and ECRH conditioning discharges in helium turned out to be important for density and edge radiation control. Plasma densities of with central electron temperatures were routinely achieved with hydrogen gas fueling, frequently terminated by a radiative collapse. In a first stage, plasma densities up to were reached with hydrogen pellet injection and helium gas fueling. Here, the ions are indirectly heated, and at a central density of a temperature of with was transiently accomplished, which corresponds to with a peak diamagnetic energy of and volume-averaged normalized plasma pressure . The routine access to high plasma densities was opened with boronization of the first wall. After boronization, the oxygen impurity content was reduced by a factor of 10, the carbon impurity content by a factor of 5. The reduced (edge) plasma radiation level gives routinely access to higher densities without radiation collapse, e.g. well above line integrated density and central temperatures at moderate ECRH power. Both X2 and O2 mode ECRH schemes were successfully applied. Core turbulence was measured with a phase contrast imaging diagnostic and suppression of turbulence during pellet injection was observed.

Age-related macular degeneration (AMD) is the predominant cause of vision loss in the elderly with a major impact on ageing societies and healthcare systems. A major challenge in AMD management is the difficulty to determine the disease stage, the highly variable progression speed and the risk of conversion to advanced AMD, where irreversible functional loss occurs. In this study we developed an optical coherence tomography (OCT) imaging based spatio-temporal reference frame to characterize the morphologic progression of intermediate age-related macular degeneration (AMD) and to identify distinctive patterns of conversion to the advanced stages macular neovascularization (MNV) and macular atrophy (MA). We included 10,040 OCT volumes of 518 eyes with intermediate AMD acquired according to a standardized protocol in monthly intervals over two years. Two independent masked retina specialists determined the time of conversion to MNV or MA. All scans were aligned to a common reference frame by intra-patient and inter-patient registration. Automated segmentations of retinal layers and the choroid were computed and en-face maps were transformed into the common reference frame. Population maps were constructed in the subgroups converting to MNV (n=135), MA (n=50) and in non-progressors (n=333). Topographically resolved maps of changes were computed and tested for statistical significant differences. The development over time was analysed by a joint model accounting for longitudinal and right-censoring aspect. Significantly enhanced thinning of the outer nuclear layer (ONL) and retinal pigment epithelium (RPE)–photoreceptorinner segment/outer segment (PR-IS/OS) layers within the central 3 mm and a faster thinning speed preceding conversion was documented for MA progressors. Converters to MNV presented an accelerated thinning of the choroid and appearance changes in the choroid prior to MNV onset. The large-scale automated image analysis allowed us to distinctly assess the progression of morphologic changes in intermediate AMD based on conventional OCT imaging. Distinct topographic and temporal patterns allow to prospectively determine eyes with risk of progression and thereby greatly improving early detection, prevention and development of novel therapeutic strategies.

Objective Telescopic crowns are suitable components of partial dentures to efficiently anchor dental supra-structures to teeth or dental implants and achieve high chewing performance and wear comfort. Usually alloy- or metal-based structures are used for the primary and the secondary crowns. The advantage is the possibility to produce precise structures with a high perfection and sufficient friction force, but the disadvantage is the corrosion instability. The recent introduction of zirconia ceramics has enabled the fabrication of ceramic primary crowns, thus reducing corrodibility. The novel application of the high-performance polymer polyetheretherketone (PEEK) as another metal-free alternative material offers a new perspective for such applications. Therefore, the aim of this work was to assess the performance of telescopic crowns of PEEK by comparing telescopic crowns based on the combination of PEEK (prim. crown) + PEEK (sec. crown) with the pairings ZrO2 (prim. crown) + PEEK (sec. crown) and CoCr-alloy (prim. crown) + PEEK (sec. crown). Methods All specimens were CAD/CAM planned and manufactured based on a model of a tooth 26. One master dental technician performed the post-treatment. For each group of material pairing, n = 9 telescopic crown pairs were manufactured and tested. Herein not only the maximum retention force was measured but also the retention force vs. pull-off distance were analyzed. As there is no commonly accepted test protocol available, the influence of various pull off speeds were tested as well. All measurements were first made with three blocks of three crowns (3C), subsequently with three blocks of two crowns (2C) and finally with nine single crowns (1C). The long-term behavior was estimated by performing 10.000 cycles, which is related to a life-time of more than 10 years. Results The maximum retention force in case of PEEK + PEEK was higher in comparison to the other tested material pairings. In the range between 1 and 10 mm/ min pull off speed there was no significant influence by the pull off speed. More influence on the friction force would be expected by changes of the number of the crowns acting simultaneously. The friction force was decreasing with decreasing number of crowns but not linearly in any tested case. The long-term test has shown that the friction force remained constant. Significance The performance of PEEK + PEEK telescopes is comparable with the usually applied material pairings. Over long time no loss in retention force could be observed. The retention force - distance progression in the PEEK + PEEK pairing offers more security against a possible loss of retention during repair or relining. For further tests of the performance of telescopic crowns or to estimate of friction force limits, a setup with at least two, but preferably three, crowns tested in parallel is suggested.

MYO7A gene encodes unconventional myosin VIIA, which, when mutated, causes a phenotypic spectrum ranging from recessive hearing loss DFNB2 to deaf-blindness, Usher Type 1B (USH1B). MYO7A mutations are reported in nine DFNB2 families to date, none from sub-Saharan Africa.In DNA, from a cohort of 94 individuals representing 92 families from the Limpopo province of South Africa, eight MYO7A variations were detected among 10 individuals. Family studies identified homozygous and compound heterozygous mutations in 17 individuals out of 32 available family members. Four mutations were novel, p.Gly329Asp, p.Arg373His, p.Tyr1780Ser, and p.Pro2126Leufs*5. Two variations, p.Ser617Pro and p.Thr381Met, previously listed as of uncertain significance (ClinVar), were confirmed to be pathogenic. The identified mutations are predicted to interfere with the conformational properties of myosin VIIA through interruption or abrogation of multiple interactions between the mutant and neighbouring residues. Specifically, p.Pro2126Leufs*5, is predicted to abolish the critical site for the interactions between the tail and the motor domain essential for the autoregulation, leaving a non-functional, unregulated protein that causes hearing loss. We have identified MYO7A as a possible key deafness gene among indigenous sub-Saharan Africans. The spectrum of MYO7A mutations in this South African population points to DFNB2 as a specific entity that may occur in a homozygous or in a compound heterozygous state.

The manuscript presents a systematic study on three groups of Ni-based cemented carbides (WC-20 wt% Ni, WC-20 wt% Ni15Cr and WC-20 wt% Ni11Cr6Mo) based on thermodynamic calculations and experimental studies. Samples were prepared with different gross carbon contents (carbon activities) with the aim to provide a comprehensive overview on: constitution and phase formation, solubility of elements in the binder phase, binder and composite hardness, as well as their corrosion behaviour. A WC-20 wt% Co8Cr was used as standard binder system for comparison. The results show that the amount of alloying elements that can be dissolved in the binder phase is significantly higher in the Ni binder as compared to the Co binder (e.g., the solubility of W in WC-Ni is about double of that observed in conventional WC-Co). The degree of alloying is primarily affected by the carbon content. The lower the gross carbon content within the processing window, the higher is the degree of binder alloying. In WC-Ni, up to 12 at.% W is observed in solution in low carbon alloys, as compared to 4 at.% W in high carbon grades. Additions of Cr are limited to 9–11 at.% Cr, depending on the gross carbon content. When exceeding this value, Cr3C2 is formed in high carbon Ni alloys. The solubility of Mo in WC-NiCrMo cemented carbides is limited to about 2 at.%, at higher additions a carbide is formed, most likely (W,Mo)C. The high hardness values observed in NiCr and NiCrMo alloys when compared to plain Ni alloys can be attributed to the effect of Cr and Mo as WC grain growth inhibitors, and not to a significant enhancement of the intrinsic binder hardness. In contrast, our standard Co grade demonstrated a significantly higher binder and composite hardness than all of the nickel variants studied. Finally, high-alloyed materials (low carbon NiCr- and NiCrMo alloys) did present a superior corrosion resistance compared to the CoCr grade even in the most severe corrosion environments. Higher degree of alloying (i.e., higher amounts of Cr, W, and Mo present in solid solution in the binder) is indicative of superior corrosion behaviour due to the nature of the protective layers formed under corrosive environments.

Design of experiments was employed to investigate the combinations of 3D-printing parameters for Polyether ether ketone (PEEK) with a fused filament fabrication (FFF) process and to quantitatively evaluate the quality of 3D printed parts. This research was conducted using a newly developed FFF 3D printer and PEEK filament. Standard PEEK parts were 3D printed for bending and compression tests. Based on the Box-Behnken design, a three factors based experiment was designed using the Response Surface Methodology (RSM). Nozzle diameter, nozzle temperature and printing speed were involved. The density and dimensional accuracy of these printed parts were evaluated, and the bending and compression tests were conducted. The nozzle diameter was found to be the most significant parameter affecting the bending and compression performance of the printed PEEK samples, followed by printing speed and nozzle temperature. The highest accuracy in sample width was obtained with a 0.6 mm nozzle while the most accurate diameter was obtained with a 0.4 mm nozzle. A combination of a 0.4 mm nozzle diameter, 430 °C nozzle temperature and printing speed of 5 mm/s was beneficial to get the densest samples and therefore the highest bending strength; a reduction of internal defects was achieved with a 0.2 mm nozzle, a higher nozzle temperature of 440 °C and slower printing speed leading to better bending modulus. The best compression properties were achieved with a 0.6 mm nozzle, with relatively low influence of the other parameters. Different parameter combinations have been found to obtain optimal mechanical properties. Optimized parameters for better dimension accuracy of small additively manufactured PEEK parts were also achieved depending on the shape of the specimens.

Objective Plasma treatment can be used as surface treatment of PEEK (poly-ether-ether-ketone) to increase the bonding strength between veneering composite and dental prosthetic frameworks of PEEK or enhance biocompatibility of PEEK implants. These improvements are probably based on chemical changes of the PEEK surface. However, the aim of the study was to evaluate the impact of different low-pressure plasma treatments on surface properties of PEEK, such as roughness, hydrophilicity, micro-hardness, crystallinity and biological activity of PEEK. Methods Due to different plasma treatments, 143 disc-shaped specimens of pure implantable PEEK were divided into 4 groups: PEEK (no plasma treatment, n = 29), H-PEEK (hydrogen plasma treatment, n = 38), O-PEEK (oxygen plasma treatment, n = 38), H/O-PEEK (hydrogen/oxygen plasma treatment with a gas mix ratio of 2:1, n = 38). Subsequently, surface roughness, surface contact angle, surface crystallinity, surface micro-hardness and human osteoblast cell coverage area of each group were examined. Results The hydrophilicity, crystallinity and micro-hardness of the plasma-treated groups increased significantly compared to the untreated group, whereas significant differences in the results of the micro-hardness tests could be shown between all groups up to a test force of 0.02N. Cell density was significantly higher on treated vs. untreated PEEK surfaces. Oxygen and H/O plasma treatments revealed to be most effective, whereas H/O plasma worked ten times faster to achieve the same effects. Significance The hydrogen-oxygen, 2/1-mixed plasma treatment combines the effect of hydrogen and oxygen plasma which strongly improve the surface properties of PEEK implant material, such as hydrophilicity, crystallinity, surface micro-hardness and HOB cell adhesion.

International audience; We describe an efficient three‐enzyme, sequential one‐pot cascade reaction where both transketolase substrates are generated in situ in a convergent fashion. The nucleophilic donor substrate hydroxypyruvate was obtained from l‐serine and pyruvate by a transaminase‐catalyzed reaction. In parallel, three different (2S)‐α‐hydroxylated aldehydes, l‐glyceraldehyde, d‐threose, and l‐erythrose, were generated as electrophilic acceptors from simple achiral compounds glycolaldehyde and formaldehyde by d‐fructose‐6‐phosphate aldolase catalysis. The compatibility of the three enzymes was studied in terms of temperature, enzyme ratio and substrate concentration. The efficiency of the process relied on the irreversibility of the transketolase reaction, driving a shift of the reversible transamination reaction and securing the complete conversion of all substrates. Three valuable (3S,4S)‐ketoses, l‐ribulose, d‐tagatose, and l‐psicose were obtained in good yields with high diastereoselectivity.

In food biotechnology, Pleurotus ostreatus is of great interest as a source of natural antioxidants and angiotensin-converting enzyme (ACE) inhibitors. However, research in this area has not yet been completed. The effect of various drying methods on the structural properties and the rehydration capacity of mushrooms was investigated in this paper. The content of secondary metabolites, the peptide profile, and the antioxidative effect and ACE inhibitory activity of dry mushrooms were investigated in vitro, simulating the process of gastrointestinal digestion. X-ray microtomography has confirmed that structure of lyophilic and sun-dried mushrooms is dominated by open pores, and in mushrooms dried with hot air and microwave, closed pores. Experiments have shown that the conditions of freeze drying and sun drying of Pleurotus ostreatus provide a higher rehydration capacity of dried mushrooms. The maximum activity of radical absorption of the oyster mushroom after microwave drying was observed. The iron restoring capacity of the mushrooms is maximally maintained with microwave drying and hot-air drying. The properties of the antioxidant product with an emphasis on the high activity of inhibiting lipid oxidation of the mushroom maximized after drying in the sun. Mushrooms dried lyophilically and in the sun showed the highest ACE inhibitory activity.

In this review, we discuss the parameters of fused deposition modeling (FDM) technology used in finished parts made from polyether ether ketone (PEEK) and also the possibility of printing small PEEK parts. The published articles reporting on 3D printed PEEK implants were obtained using PubMed and search engines such as Google Scholar including references cited therein. The results indicate that although many have been experiments conducted on PEEK 3D printing, the consensus on a suitable printing parameter combination has not been reached and optimized parameters for printing worth pursuing. The printing of reproducible tiny-sized PEEK parts with high accuracy has proved to be possible in our experiments. Understanding the relationships among material properties, design parameters, and the ultimate performance of finished objects will be the basis for further improvement of the quality of 3D printed medical devices based on PEEK and to expand the polymers applications.

International audience; The thermostable transketolase from Geobacillus stearothermophilus (TKgst) was successfully engineered for the synthesis of aliphatic acyloins with varying carbon backbone lengths (C5−C10) based on protein structure‐guided studies. Efficient TKgst variants were identified with enhanced activities for substrate combinations of aliphatic aldehydes as acceptors together with aliphatic pyruvate homologues as donors. The TKgst single variant L382F was able to catalyze efficiently the transfer of the ketol group from hydroxypyruvate on all targeted aliphatic aldehydes (C3−C8) to give the corresponding 1,3‐dihydroxy ketones with good yields and excellent enantioselectivity. The combination of the H102L/H474S mutation previously designed for the improved utilization of aliphatic pyruvate homologues together with a F435I exchange gave the new variant H102L/H474S/F435I, which is able to transfer the acyl goup of 2‐oxobutyrate and 2‐oxovalerate to aliphatic aldehydes, giving mono hydroxylated ketones.

A protein engineering approach for expanding the substrate scope of the (S)-selective Chromobacterium violaceum amine transaminase is presented. Amino acid residues in the small binding pocket of the active site were targeted in order to increase the pocket size for acceptance of primary amines bearing two bulky groups. A highly sensitive fluorescence assay was then used to evaluate the generated enzyme variants for their activity towards propyl- and benzyl-substituted screening substrates. The best variant, L59A/F88A, was successfully applied in the kinetic resolution of 1,2-diphenylethylamine using different conditions and substrate loadings. The variant L59A/F88A generated enantiomerically pure (R)-1,2-diphenylethylamine with ee>99% under all tested conditions. The variant also holds great promise for synthesis of hydrophobic compounds as it shows optimum activity when 20-30% (v/v) DMSO is applied as cosolvent. The variant L59A/F88A provides a great addition to the available catalyst toolbox for synthesis of chiral amines, as it is the first published (S)-selective amine transaminase showing activity towards benzyl-substituted primary amines.

Ophthalmology is at the forefront of deep learning applications due to the ability to image the retina with OCT. We present how deep learning is used for quantification of imaging biomarkers and predicting disease progression.

The chapter summarizes genetic and breeding basics of 2255 medicinal, aromatic, and stimulant plant species. This special plant group contains very different species from all plant families. The DNA C-value is one of the basics for several molecular methods. The gametophytic and sporophytic chromosome numbers show the ploidy level and support selection of an appropriate breeding method. Another important prerequisite to effective breeding work is basic knowledge of flower and pollination biology of the respective species. The compilation can serve as a stepping stone for planning new breeding projects.

Asymmetric aldol addition of simple aldehydes and ketones to electrophiles is a cornerstone reaction for the synthesis of unusual sugars and chiral building blocks. We investigated D-fructose-6-phosphate aldolase from E. coli (FSA) D6X variants as catalysts for the aldol additions of linear and cyclic non-functionalized aliphatic ketones or ethanal as nucleophiles to non-phosphorylated hydroxyaldehydes. Thus, addition of propanone, cyclobutanone, cyclopentanone or ethanal to 3-hydroxypropanal or (S)- or (R)-3-hydroxybutanal catalyzed by FSA D6H and D6Q variants furnished rare deoxysugars in 8-77% isolated yields with high stereoselectivity (97:3 dr and >95% ee). © 2018 American Chemical Society., This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No 635595 (CarbaZymes), the Ministerio de Economía y Competitividad (MINECO), the Fondo Europeo de Desarrollo Regional (FEDER) (grant CTQ2015-63563-R to P.C. and CTQ2015-64436-P to T.P.), COST action CM1303 Systems Biocatalysis and funding from the Auvergne council.

Endospores of thermophilic bacilli are a major concern for producers of dairy powders. In this study, we heat treated 10 different spore suspensions at 110 °C in skim milk and skim milk concentrate (36% dry matter) of the species Geobacillus stearothermophilus (10 min) and Anoxybacillus flavithermus (5 min) in a new shear-heating device. The highest log reduction in skim milk concentrate was 3.5. The death behavior of the spores was strain dependent. Particle formation and Maillard reaction were observed. By increasing the shear-rate up to 1500 s−1 the particle size was reduced for both heating times (D90 reduction: 57.4 and 77.0%, respectively). The particle size was lessened by a reduction of dry matter of 27%, compared to 36%. This work emphasizes, that heat treatment of concentrated dairy products represents a technological option to reduce thermophilic spores in skim milk concentrate and powders produced thereof.

The properties of cemented carbides are heavily influenced by the tungsten carbide (WC) powders used in its production. Overall particle size of the WC is most influential, however, in the medium- and coarse-grained tungsten carbide particle range the internal crystallographic structure of the polycrystalline WC is important as well. To investigate the crystal formation of WC and it's resulting structure, selected crystal growth experiments were performed. The transition of ditungsten carbide (W2C) into tungsten carbide (WC) during carburization of tungsten powder was studied. The experimental strategy was to obtain W2C along with WC within the growing carbide particles. Electron microscopy methods were utilized to study the growth mechanism during conversion of W2C into WC, and to detect the existence of preferred crystallographic orientations during the transition process.

In general the cemented carbide industry uses cobalt as a raw material for the production of WC-Co cemented carbide. However the here presented publication shows that even if 100% of the cobalt of the cemented carbide is replaced with Co3O4 prior sintering, dense WC-Co cemented carbide can be achieved when the sintering program contains a hydrogen treatment. The point of the matter when using a cemented carbide powder which contains cobalt oxide (WC-Co3O4) are the huge differences in the compressibility compared to a conventional powder (WC-Co). Depending on the ratio of cobalt and cobalt oxide in the cemented carbide composition the compressibility of the powder/granule can be adjusted in a wide range. This opens up the possibility to produce different cemented carbide grades with an identical compressibility. As a consequence costs for additional pressing tools can be saved.

Transglutaminase from Streptomyces mobaraensis (MTG) has become a powerful tool to covalently and highly specifically link functional amines to glutamine donor sites of therapeutic proteins. However, details regarding the mechanism of substrate recognition and interaction of the enzyme with proteinaceous substrates still remain mostly elusive. We have determined the crystal structure of the Streptomyces papain inhibitory protein (SPIp ), a substrate of MTG, to study the influence of various substrate amino acids on positioning glutamine to the active site of MTG. SPIp exhibits a rigid, thermo-resistant double-psi-beta-barrel fold that is stabilized by two cysteine bridges. Incorporation of biotin cadaverine identified Gln-6 as the only amine acceptor site on SPIp accessible for MTG. Substitution of Lys-7 demonstrated that small and hydrophobic residues in close proximity to Gln-6 favor MTG-mediated modification and are likely to facilitate introduction of the substrate into the front vestibule of MTG. Moreover, exchange of various surface residues of SPIp for arginine and glutamate/aspartate outside the glutamine donor region influences the efficiency of modification by MTG. These results suggest the occurrence of charged contact areas between MTG and the acyl donor substrates beyond the front vestibule, and pave the way for protein engineering approaches to improve the properties of artificial MTG-substrates used in biomedical applications.

Cuboidal and coherent precipitates form in ternary cobalt-aluminium‑tungsten systems and are described to increase high temperature toughness of superalloys for gas turbines. γ’ is a metastable phase in the form of Co3(Al,W) which is stabilized by the substitution of cobalt with nickel. Strengthening of cobalt binder (γ) in cemented carbides by precipitation hardening is of interest as it potentially increases hardness and wear resistance without sacrificing tensile strength or toughness of the composite materials. Infiltration of preliminary produced cobalt-base and cobalt‑nickel-base superalloys into tungsten carbide powder beds yielded a γ/γ’ binder microstructure. It was shown that nickel stabilizes the γ’ phase in superalloys as well as in cemented carbides, but carbon may lead to the formation of an additional κ phase with E21 structure.

Four new components named aethusifolins A–D (1–4), together with ten known (5–14) were isolated from the dried aerial parts of a traditional Mongolian medicinal herb Clematis aethusifolia Turcz. The planar structures were established based on extensive spectroscopic analysis (HRMS, 1D and 2D NMR), and the absolute configurations were determined by modified Mosher’s method, hydrolysis method. The cytotoxicities of isolated compounds against a panel of five human solid tumor cell lines were assayed. Compounds 5, 8, and 13 showed moderate cytotoxicity against A-375 with IC50 values of 15–18 μM, while compound 8 also showed cytotoxicity against SH-SY5Y with IC50 values of 20 μM.

In chemistry and physics the electronic charge on a species or material is one important determinant of its properties. In the present Minireview, the essential requirements for a model catalyst system suitable to study charge control are discussed. The ideal model catalyst for this purpose consists of a material system, which comprises a single crystal metal support, covered by an epitaxially grown ultrathin oxide film, and flat, two-dimensional nanoparticles residing on this film. Several examples from the literature are selected and presented, which illustrate various aspects of electron transport from the support to the nanoparticle and vice versa. Key experiments demonstrate charge control within such model catalysts and give direct evidence for a chemical reaction at the perimeter of Au nanoparticles. The concepts derived from these studies are then taken a step further to see how they may be applied for bulk powder oxide supported nanoparticles as they are frequently found in catalytically active materials.

Recycling is an essential part of the global tungsten flow. A wide variety of recycling technologies for tungsten exists today. Processes are tailored to deal with different scrap types and to produce well-defined recycling products. The paper presents the current share of recycling in the global tungsten flow and elaborates on the economy of recycling. The available recycling technologies and their industrial relevance is summarized. Based on the tungsten end-use pattern and the associated tungsten products, the future potential of tungsten recycling is discussed.