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201.
Maria Saladina Pablo Simón Marqués Anastasia Markina Safakath Karuthedath Christopher Wöpke Clemens Göhler Yue Chen Magali Allain Philippe Blanchard Clément Cabanetos Denis Andrienko Frédéric Laquai Julien Gorenflot Carsten Deibel 《Advanced functional materials》2021,31(8):2007479
In organic solar cells, photogenerated singlet excitons form charge transfer (CT) complexes, which subsequently split into free charge carriers. Here, the contributions of excess energy and molecular quadrupole moments to the charge separation process are considered. The charge photogeneration in two separate bulk heterojunction systems consisting of the polymer donor PTB7-Th and two non-fullerene acceptors, ITIC and h-ITIC, is investigated. CT state dissociation in these donor–acceptor systems is monitored by charge density decay dynamics obtained from transient absorption experiments. The electric field dependence of charge carrier generation is studied at different excitation energies by time delayed collection field (TDCF) and sensitive steady-state photocurrent measurements. Upon excitation below the optical gap, free charge carrier generation becomes less field dependent with increasing photon energy, which challenges the view of charge photogeneration proceeding through energetically lowest CT states. The average distance between electron–hole pairs at the donor–acceptor interface is determined from empirical fits to the TDCF data. The delocalization of CT states is larger in PTB7-Th:ITIC, the system with larger molecular quadrupole moment, indicating the sizeable effect of the electrostatic potential at the donor–acceptor interface on the dissociation of CT complexes. 相似文献
202.
Prasoon Kumar Khalid Baig Mirza Kaushik Choudhury Magali Cucchiarini Henning Madry Pratyoosh Shukla 《Advanced functional materials》2021,31(31):2009663
Tissue engineering is a systematic approach of assembling cells onto a 3D scaffold to form a functional tissue in the presence of critical growth factors. The scaffolding system guides stem cells through topological, physiochemical, and mechanical cues to differentiate and integrate to form a functional tissue. However, cellular communication during tissue formation taking place in a reactor needs to be understood properly to enable appropriate positioning of the cells in a 3D environment. Hence, sensors and actuators integrated with cyber-physical system (CPS) may be able to sense the tissue microenvironment and direct cells/cellular aggregates to an appropriate position, respectively. This can facilitate better cell-to-cell communication and cell–extracellular matrix communication for proper tissue morphogenesis. Advancements are made in the field of smart scaffolds that can morph cells/cellular aggregates after sensing the cellular microenvironment in a desired 3D architecture by providing appropriate cues. Recent scientific developments in the additive manufacturing technology have enabled the fabrication of smart scaffolds to create structural and functional tissue constructs. Sensors/actuators, cyber-systems, smart materials, and additive manufacturing put together is expected to lead to improved tissue-engineered medical products. The present review aims to highlight the possibilities of advancement of BioCPS for tissue engineering and regenerative medicine. 相似文献
203.
Carolina F. Rodrigues Patrícia T. Borges Magali F. Scocozza Diogo Silva Andr Taborda Vnia Brissos Carlos Frazo Lígia O. Martins 《International journal of molecular sciences》2021,22(19)
Bacillus subtilis BsDyP belongs to class I of the dye-decolorizing peroxidase (DyP) family of enzymes and is an interesting biocatalyst due to its high redox potential, broad substrate spectrum and thermostability. This work reports the optimization of BsDyP using directed evolution for improved oxidation of 2,6-dimethoxyphenol, a model lignin-derived phenolic. After three rounds of evolution, one variant was identified displaying 7-fold higher catalytic rates and higher production yields as compared to the wild-type enzyme. The analysis of X-ray structures of the wild type and the evolved variant showed that the heme pocket is delimited by three long conserved loop regions and a small α helix where, incidentally, the mutations were inserted in the course of evolution. One loop in the proximal side of the heme pocket becomes more flexible in the evolved variant and the size of the active site cavity is increased, as well as the width of its mouth, resulting in an enhanced exposure of the heme to solvent. These conformational changes have a positive functional role in facilitating electron transfer from the substrate to the enzyme. However, they concomitantly resulted in decreasing the enzyme’s overall stability by 2 kcal mol−1, indicating a trade-off between functionality and stability. Furthermore, the evolved variant exhibited slightly reduced thermal stability compared to the wild type. The obtained data indicate that understanding the role of loops close to the heme pocket in the catalysis and stability of DyPs is critical for the development of new and more powerful biocatalysts: loops can be modulated for tuning important DyP properties such as activity, specificity and stability. 相似文献
204.
205.
Rodrigo Teodoro Daniel Gündel Winnie Deuther-Conrad Lea Ueberham Magali Toussaint Guy Bormans Peter Brust Rare-Petru Moldovan 《International journal of molecular sciences》2021,22(15)
Cannabinoid receptors type 2 (CB2R) represent an attractive therapeutic target for neurodegenerative diseases and cancer. Aiming at the development of a positron emission tomography (PET) radiotracer to monitor receptor density and/or occupancy during a CB2R-tailored therapy, we herein describe the radiosynthesis of cis-[18F]1-(4-fluorobutyl-N-((1s,4s)-4-methylcyclohexyl)-2-oxo-1,2-dihydro-1,8-naphthyridine-3-carboxamide ([18F]LU14) starting from the corresponding mesylate precursor. The first biological evaluation revealed that [18F]LU14 is a highly affine CB2R radioligand with >80% intact tracer in the brain at 30 min p.i. Its further evaluation by PET in a well-established rat model of CB2R overexpression demonstrated its ability to selectively image the CB2R in the brain and its potential as a tracer to further investigate disease-related changes in CB2R expression. 相似文献
206.
Daniel Gündel Masoud Sadeghzadeh Winnie Deuther-Conrad Barbara Wenzel Paul Cumming Magali Toussaint Friedrich-Alexander Ludwig Rare-Petru Moldovan Mathias Kranz Rodrigo Teodoro Bernhard Sattler Osama Sabri Peter Brust 《International journal of molecular sciences》2021,22(4)
The expression of monocarboxylate transporters (MCTs) is linked to pathophysiological changes in diseases, including cancer, such that MCTs could potentially serve as diagnostic markers or therapeutic targets. We recently developed [18F]FACH as a radiotracer for non-invasive molecular imaging of MCTs by positron emission tomography (PET). The aim of this study was to evaluate further the specificity, metabolic stability, and pharmacokinetics of [18F]FACH in healthy mice and piglets. We measured the [18F]FACH plasma protein binding fractions in mice and piglets and the specific binding in cryosections of murine kidney and lung. The biodistribution of [18F]FACH was evaluated by tissue sampling ex vivo and by dynamic PET/MRI in vivo, with and without pre-treatment by the MCT inhibitor α-CCA-Na or the reference compound, FACH-Na. Additionally, we performed compartmental modelling of the PET signal in kidney cortex and liver. Saturation binding studies in kidney cortex cryosections indicated a KD of 118 ± 12 nM and Bmax of 6.0 pmol/mg wet weight. The specificity of [18F]FACH uptake in the kidney cortex was confirmed in vivo by reductions in AUC0–60min after pre-treatment with α-CCA-Na in mice (−47%) and in piglets (−66%). [18F]FACH was metabolically stable in mouse, but polar radio-metabolites were present in plasma and tissues of piglets. The [18F]FACH binding potential (BPND) in the kidney cortex was approximately 1.3 in mice. The MCT1 specificity of [18F]FACH uptake was confirmed by displacement studies in 4T1 cells. [18F]FACH has suitable properties for the detection of the MCTs in kidney, and thus has potential as a molecular imaging tool for MCT-related pathologies, which should next be assessed in relevant disease models. 相似文献
207.
Andrea Magali Gonzlez-Mora Patricia Garcia-Lopez 《International journal of molecular sciences》2021,22(22)
Hormonal factors may participate in the development and progression of glioblastoma, the most aggressive primary tumor of the central nervous system. Many studies have been conducted on the possible involvement of estrogen receptors (ERs) in gliomas. Since there is a tendency for a reduced expression of ERs as the degree of malignancy of such tumors increases, it is important to understand the role of these receptors in the progression and treatment of this disease. ERs belong to the family of nuclear receptors, although they can also be in the plasmatic membrane, cytoplasm and mitochondria. They are classified as estrogen receptors alpha and beta (ER⍺ and ERβ), each with different isoforms that have a distinct function in the organism. ERs regulate multiple physiological and pathological processes through the activation of genomic and nongenomic pathways in the cell. Nevertheless, the role of each isoform in the development and progression of glioblastoma is not completely clear. Diverse in vitro and in vivo studies have shown encouraging results for endocrine therapy as a treatment for gliomas. At the same time, many questions have arisen concerning the nature of ERs as well as the mechanism of action of the proposed drugs. Hence, the aim of the current review is to describe the drugs that could possibly be utilized in endocrine therapy for the treatment of high-grade gliomas, analyze their interaction with ERs, and explore the involvement of these drugs and receptors in resistance to standard chemotherapy. 相似文献
208.
Marie-Sophie Bounaix Hervé Robert Magali Remaud-Siméon Catherine Fontagné-Faucher 《International journal of food microbiology》2010,144(1):1-9
Sourdough was previously demonstrated to be a fruitful biotope for isolation of lactic acid bacteria producing exopolysaccharides and more accurately diverse glycan polymers which have interesting applications as texturing agents or prebiotics. Characterization of polymers by 1H and 13C NMR spectroscopy analysis demonstrated that these strains could synthesize glucans of high structural variety and containing different amounts of α-(1 → 2), α-(1 → 3) and α-(1 → 6) linkages. In this study, fifteen glucan-producing Leuconostoc mesenteroides and L. citreum strains from sourdoughs were characterized according to carbohydrate fermentation, rep-PCR fingerprinting using (GTG)5 primers and glycansucrase activity (soluble or cell-associated). Enzyme characterization using SDS-PAGE and in situ polymer production after incubation with sucrose correlated with synthesis of classical or α-(1 → 2) branched dextrans, alternan and levan. In addition, the presence of genes coding for alternansucrase was detected by PCR and partially characterized by sequence analysis. We thus provide new information on the biodiversity of glucan production by sourdough Leuconostoc strains. 相似文献
209.
NMR-based structural glycomics for high-throughput screening of carbohydrate-active enzyme specificity 总被引：1，自引：0，他引：1
Irague R Massou S Moulis C Saurel O Milon A Monsan P Remaud-Siméon M Portais JC Potocki-Véronèse G 《Analytical chemistry》2011,83(4):1202-1206
We report here the development of a straightforward, sensitive, and quantitative NMR-based method for high-throughput characterization of carbohydrate structure and screening of carbohydrate active enzyme (CAZyme) specificity. Automated assays starting from gene library expression to carbohydrate structure determination directly from crude reaction media have been established and successfully used to screen a library of 4032 CAZymes obtained by combinatorial engineering, at a rate of 480 enzyme variants per day. This allowed one to accurately discriminate 303 enzyme variants with altered specificity. The results demonstrate the potential of high-throughput NMR technology in glycomics, to mine artificial and natural enzyme diversity for novel biocatalysts. 相似文献
210.
Leidy C Ortiz Araque Magali Darré Cristian M Ortiz Juan F Massolo Ariel R Vicente 《International Journal of Dairy Technology》2018,71(2):340-346
Milk processing conditions can exert a large influence on the quality of acid‐coagulated cheeses. Herein, we evaluated the influence of milk fat content and coagulant type on Ricotta yield and physical, chemical and sensory properties. Fat‐free Ricotta was hard and whiter than reduced‐fat or full‐fat Ricotta. Ricotta produced from low‐fat and whole milk showed no differences in acceptability, indicating that fat content could be substantially reduced without impairing quality. Milk coagulation by citric acid decreased Ricotta moisture, firmness and yield, whereas calcium chloride produced a white Ricotta with desired firmness and high consumer acceptability. 相似文献