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31.
32.
Nina-Katharina Krahe Prof. Dr. Dr. Ralf G. Berger Lukas Kahlert Dr. Franziska Ersoy 《Chembiochem : a European journal of chemical biology》2021,22(19):2857-2861
The valuable aroma compound piperonal with its vanilla-like olfactory properties is of high interest for the fragrance and flavor industry. A lipoxygenase (LOXPsa1) of the basidiomycete Pleurotus sapidus was identified to convert piperine, the abundant pungent principle of black pepper (Piper nigrum), to piperonal and a second volatile product, 3,4-methylenedioxycinnamaldehyde, with a vanilla-like odor through an alkene cleavage. The reaction principle was co-oxidation, as proven by its dependence on the presence of linoleic or α-linolenic acid, common substrates of lipoxygenases. Optimization of the reaction conditions (substrate concentrations, reaction temperature and time) led to a 24-fold and 15-fold increase of the piperonal and 3,4-methylenedioxycinnamaldehyde concentration using the recombinant enzyme. Monokaryotic strains showed different concentrations of and ratios between the two reaction products. 相似文献
33.
Dniel Zmb Anja Schlosser Pascal Rusch Franziska Lübkemann Julian Koch Herbert Pfnür Nadja C. Bigall 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(16)
3D nanoparticle assemblies offer a unique platform to enhance and extend the functionality and optical/electrical properties of individual nanoparticles. Especially, a self‐supported, voluminous, and porous macroscopic material built up from interconnected semiconductor nanoparticles provides new possibilities in the field of sensing, optoelectronics, and photovoltaics. Herein, a method is demonstrated for assembling semiconductor nanoparticle systems containing building blocks possessing different composition, size, shape, and surface ligands. The method is based on the controlled destabilization of the particles triggered by trivalent cations (Y3+, Yb3+, and Al3+). The effect of the cations is investigated via X‐ray photoelectron spectroscopy. The macroscopic, self‐supported aerogels consist of the hyperbranched network of interconnected CdSe/CdS dot‐in‐rods, or CdSe/CdS as well as CdSe/CdTe core‐crown nanoplatelets is used to demonstrate the versatility of the procedure. The non‐oxidative assembly method takes place at room temperature without thermal activation in several hours and preserves the shape and the fluorescence of the building blocks. The assembled nanoparticle network provides longer exciton lifetimes with retained photoluminescence quantum yields, that make these nanostructured materials a perfect platform for novel multifunctional 3D networks in sensing. Various sets of photoelectrochemical measurements on the interconnected semiconductor nanorod structures also reveal the enhanced charge carrier separation. 相似文献
34.
Franziska Lübkemann Jan Frederick Miethe Frank Steinbach Pascal Rusch Anja Schlosser Dniel Zmb Thea Heinemeyer Dominik Natke Dorian Zok Dirk Dorfs Nadja C. Bigall 《Small (Weinheim an der Bergstrasse, Germany)》2019,15(39)
Nanoparticle‐based voluminous 3D networks with low densities are a unique class of materials and are commonly known as aerogels. Due to the high surface‐to‐volume ratio, aerogels and xerogels might be suitable materials for applications in different fields, e.g. photocatalysis, catalysis, or sensing. One major difficulty in the handling of nanoparticle‐based aerogels and xerogels is the defined patterning of these structures on different substrates and surfaces. The automated manufacturing of nanoparticle‐based aerogel‐ or xerogel‐coated electrodes can easily be realized via inkjet printing. The main focus of this work is the implementation of the standard nanoparticle‐based gelation process in a commercial inkjet printing system. By simultaneously printing semiconductor nanoparticles and a destabilization agent, a 3D network on a conducting and transparent surface is obtained. First spectro‐electrochemical measurements are recorded to investigate the charge–carrier mobility within these 3D semiconductor‐based xerogel networks. 相似文献
35.
Phil Opitz Laura Besch Martin Panthöfer Anke Kabelitz Ronald E. Unger Franziska Emmerling Mihail Mondeshki Wolfgang Tremel 《Advanced functional materials》2021,31(3):2007830
A protein-free formation of bone-like apatite from amorphous precursors through ball-milling is reported. Mg2+ ions are crucial to achieve full amorphization of CaCO3. Mg2+ incorporation generates defects which strongly retard a recrystallization of ball-milled Mg-doped amorphous calcium carbonate (BM-aMCC), which promotes the growth of osteoblastic and endothelial cells in simulated body fluid and has no effect on endothelial cell gene expression. Ex situ snapshots of the processes revealed the reaction mechanisms. For low Mg contents (<30%) a two phase system consisting of Mg-doped amorphous calcium carbonate (ACC) and calcite “impurities” was formed. For high (>40%) Mg2+ contents, BM-aMCC follows a different crystallization path via magnesian calcite and monohydrocalcite to aragonite. While pure ACC crystallizes rapidly to calcite in aqueous media, Mg-doped ACC forms in the presence of phosphate ions bone-like hydroxycarbonate apatite (dahllite), a carbonate apatite with carbonate substitution in both type A (OH−) and type B (PO43−) sites, which grows on calcite “impurities” via heterogeneous nucleation. This process produces an endotoxin-free material and makes BM-aMCC an excellent “ion storage buffer” that promotes cell growth by stimulating cell viability and metabolism with promising applications in the treatment of bone defects and bone degenerative diseases. 相似文献
36.
Hung-Chin Wu Franziska Lissel Ging-Ji Nathan Wang David M. Koshy Shayla Nikzad Hongping Yan Jie Xu Shaochuan Luo Naoji Matsuhisa Yuan Cheng Fan Wang Baohua Ji Dechang Li Wen-Chang Chen Gi Xue Zhenan Bao 《Advanced functional materials》2021,31(11):2009201
The backbone of diketopyrrolopyrrole-thiophene-vinylene-thiophene-based polymer semiconductors (PSCs) is modified with pyridine (Py) or bipyridine ligands to complex Fe(II) metal centers, allowing the metal–ligand complexes to act as mechanophores and dynamically crosslink the polymer chains. Mono- and bi-dentate ligands are observed to exhibit different degrees of bond strengths, which subsequently affect the mechanical properties of these Wolf-type-II metallopolymers. The counter ion also plays a crucial role, as it is observed that Py-Fe mechanophores with non-coordinating BPh4– counter ions (Py-FeB) exhibit better thin film ductility with lower elastic modulus, as compared to the coordinating chloro ligands (Py-FeC). Interestingly, besides mechanical robustness, the electrical charge carrier mobility can also be enhanced concurrently when incorporating Py-FeB mechanophores in PSCs. This is a unique observation among stretchable PSCs, especially that most reports to date describe a decreased mobility when the stretchability is improved. Next, it is determined that improvements to both mobility and stretchability are correlated to the solid-state molecular ordering and dynamics of coordination bonds under strain, as elucidated via techniques of grazing-incidence X-ray diffraction and X-ray absorption spectroscopy techniques, respectively. This study provides a viable approach to enhance both the mechanical and the electronic performance of polymer-based soft devices. 相似文献
37.
DNA Primer Extension with Cyclopropenylated 7‐Deaza‐2′‐deoxyadenosine and Efficient Bioorthogonal Labeling in Vitro and in Living Cells
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Dr. Damian Ploschik Dr. Franziska Rönicke Hanna Beike Dr. Ralf Strasser Prof. Dr. Hans‐Achim Wagenknecht 《Chembiochem : a European journal of chemical biology》2018,19(18):1949-1953
A deoxyadenosine triphosphate (dATP) analogue for DNA labeling was synthesized with the 1‐methylcyclopropene (1MCP) group at the 7‐position of 7‐deaza‐2′‐deoxyadenosine and applied for primer extension experiments. The real‐time kinetic data reveals that this 1MCP‐modified dATP analogue is incorporated into DNA much faster than that of the similarly 1MCP‐modified deoxyuridine triphosphate (dUTP) analogue. The postsynthetic fluorescent labeling of these oligonucleotides works efficiently according to PAGE analysis, and can be applied for immobilization of a functional antibody on a surface. Site‐specific labeling at two different positions in DNA was achieved and the bioorthogonality of the postsynthetic fluorescent labeling was demonstrated in living HeLa cells. 相似文献
38.
Adrian Lis Slavo Kicin Franziska Brem Christian Leinenbach 《Journal of Electronic Materials》2017,46(2):729-741
The potential of transient liquid-phase (TLP) bonding for chip packaging applications has been evaluated, focusing on three interlayer arrangements (Ag-Sn-Ag, Ni-Sn-Ni, and Ag-Sn-Ni). Shear tests on TLP-bonded components provided the interlayer-dependent mechanical strength as well as failure mode and position. Critical local stresses, i.e., failure criteria, within the intermetallic compound (IMC) layer were derived by replicating the shear test conditions with finite-element methods. The missing coefficient of thermal expansion for Ag3Sn IMC was obtained by producing small IMC bulk samples and subjecting them to dilatometric measurements. The experimental results were implemented into a finite-element model of a representative power module architecture to provide first predictions on thermally induced residual stresses that could be classified into fail/safe, as successfully validated by TLP chip bonding experiments. A numerical parameter study then assessed thermal stresses, including failure prediction and design optimization for TLP-bonded Si chips, considering the influence of process temperature, service conditions, TLP interlayer system, and metallization layers within the TLP joint. The presented procedure serves as a guideline to choose an appropriate TLP interlayer system for predefined boundary conditions, or vice versa. 相似文献
39.
Franziska Gsottberger Carolin Brandl Kerstin Wendland Srdjan Petkovic Charlotte Emmerich Ramona Erber Carol Geppert Arndt Hartmann Andreas Mackensen Lars Nitschke Fabian Müller 《International journal of molecular sciences》2021,22(19)
Targeted immunotherapies have greatly changed treatment of patients with B cell malignancies. To further enhance immunotherapies, research increasingly focuses on the tumor microenvironment (TME), which differs considerably by organ site. However, immunocompetent mouse models of disease to study immunotherapies targeting human molecules within organ-specific TME are surprisingly rare. We developed a myc-driven, primary murine lymphoma model expressing a human-mouse chimeric CD22 (h/mCD22). Stable engraftment of three distinct h/mCD22+ lymphoma was established after subcutaneous and systemic injection. However, only systemic lymphoma showed immune infiltration that reflected human disease. In this model, myeloid cells supported lymphoma growth and showed a phenotype of myeloid-derived suppressor cells. The human CD22-targeted immunotoxin Moxetumomab was highly active against h/mCD22+ lymphoma and similarly reduced infiltration of bone marrow and spleen of all three models up to 90-fold while efficacy against lymphoma in lymph nodes varied substantially, highlighting relevance of organ-specific TME. As in human aggressive lymphoma, anti-PD-L1 as monotherapy was not efficient. However, anti-PD-L1 enhanced efficacy of Moxetumomab suggesting potential for future clinical application. The novel model system of h/mCD22+ lymphoma provides a unique platform to test targeted immunotherapies and may be amenable for other human B cell targets such as CD19 and CD20. 相似文献
40.
Franziska Brauneck Elisa Seubert Jasmin Wellbrock Julian Schulze zur Wiesch Yinghui Duan Tim Magnus Carsten Bokemeyer Friedrich Koch-Nolte Stephan Menzel Walter Fiedler 《International journal of molecular sciences》2021,22(23)
This study aimed to characterize different natural killer (NK) cell phenotypes on bone marrow and peripheral blood cells from acute myeloid leukemia (AML) patients and healthy donors (HDs). Our data show that CD56dimCD16− and CD56brightCD16− NK cells represent the predominant NK cell subpopulations in AML, while the CD56dimCD16+ NK cells are significantly reduced compared to HDs. Moreover, TIGIT+ and PVRIG+ cells cluster on the CD56dimCD16+ subset whereas CD39+ and CD38+ cells do so on CD56brightCD16− NK cells in AML. Furthermore, functional effects of (co-)blockade of TIGIT and CD39 or A2AR on NK cell functionality were analyzed. These experiments revealed that the single blockade of the TIGIT receptor results in an increased NK-92 cell-mediated killing of AML cells in vitro. Combined targeting of CD39 or A2AR significantly augments the anti-TIGIT-mediated lysis of AML cells. Our data indicate that distinct NK cell subsets in AML exhibit different immunosuppressive patterns (via the TIGIT/PVRIG receptors and the purinergic pathway). In summary, we conclude that TIGIT, CD39, and A2AR constitute relevant inhibitory checkpoints of NK cells in AML patients. A combinatorial blockade synergistically strengthens NK-92 cell-mediated cytotoxicity. As inhibitors of TIGIT, CD39, and A2AR are clinically available, studies on their combined use could be conducted in the near future. 相似文献