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排序方式: 共有165条查询结果,搜索用时 171 毫秒
161.
Oliver Pabst Stefan Hölzer Erik Beckert Jolke Perelaer Ulrich S. Schubert Ramona Eberhardt Andreas Tünnermann 《Organic Electronics》2014,15(11):3306-3315
All inkjet printed piezoelectric actuators based on poly(vinylidene fluoride-co-trifluoroethylene) (P(VDF–TrFE)) for applications as pump actuators in microfluidic lab-on-a-chip systems (LOC) are manufactured and investigated in terms of their morphology and actuator performance. Furthermore, a pump demonstrator with an all-printed P(VDF–TrFE) actuator is characterized here for the first time. The actuators are manufactured in a fully additive and flexible way by successive inkjet printing of a P(VDF–TrFE) film sandwiched between two silver electrodes on a polyethylene terephthalate (PET) substrate. Different from most current micropumps where actuator elements are fabricated separately, no additional joining step is required in the manufacturing approach employed here. Actuator performance is investigated by measurements of piezoelectric d31 coefficients as well as remanent polarization Prem for different thermal treatments of the as-printed P(VDF–TrFE) films. A strong dependence of the device performance on the annealing temperature is found with maximum values for d31 and Prem of approximately 10 pm V−1 and 5.8 μC cm−2, respectively. Morphology investigations of the printed films by differential scanning calorimetry (DSC), X-ray diffraction (XRD) and Atomic Force Microscopy (AFM) indicate an increased degree of crystallinity of the piezoelectric β-phase for samples annealed at temperatures above 110 °C, which coincides with improved device performance. A basic pumping function with pump rates of up to 130 μL min−1 is demonstrated, which is promising for future applications in LOC. Furthermore, the process chain and characterization presented here can be employed to design and manufacture also other P(VDF–TrFE)-based devices and allows the combination with additional printed on-chip functionalities in future LOC. 相似文献
162.
Rosalba Siracusa Francesco Monaco Ramona DAmico Tiziana Genovese Marika Cordaro Livia Interdonato Enrico Gugliandolo Alessio Filippo Peritore Rosalia Crupi Salvatore Cuzzocrea Daniela Impellizzeri Roberta Fusco Rosanna Di Paola 《International journal of molecular sciences》2021,22(13)
Treating postoperative (PO) pain is a clinical challenge. Inadequate PO pain management can lead to worse outcomes, for example chronic post-surgical pain. Therefore, acquiring new information on the PO pain mechanism would increase the therapeutic options available. In this paper, we evaluated the role of a natural substance, epigallocatechin-3-gallate (EGCG), on pain and neuroinflammation induced by a surgical procedure in an animal model of PO pain. We performed an incision of the hind paw and EGCG was administered for five days. Mechanical allodynia, thermal hyperalgesia, and motor dysfunction were assessed 24 h, and three and five days after surgery. At the same time points, animals were sacrificed, and sera and lumbar spinal cord tissues were harvested for molecular analysis. EGCG administration significantly alleviated hyperalgesia and allodynia, and reduced motor disfunction. From the molecular point of view, EGCG reduced the activation of the WNT pathway, reducing WNT3a, cysteine-rich domain frizzled (FZ)1 and FZ8 expressions, and both cytosolic and nuclear β-catenin expression, and the noncanonical β-catenin–independent signaling pathways, reducing the activation of the NMDA receptor subtype NR2B (pNR2B), pPKC and cAMP response element-binding protein (pCREB) expressions at all time points. Additionally, EGCG reduced spinal astrocytes and microglia activation, cytokines overexpression and nuclear factor kappa-light-chain-enhancer of activated B cells (NFkB) pathway, downregulating inducible nitric oxide synthase (iNOS) activation, cyclooxygenase 2 (COX-2) expression, and prostaglandin E2 (PGE2) levels. Thus, EGCG administration managing the WNT/β-catenin signaling pathways modulates PO pain related neurochemical and inflammatory alterations. 相似文献
163.
Tiziana Genovese Marika Cordaro Rosalba Siracusa Daniela Impellizzeri Sebastiano Caudullo Emanuela Raffone Francesco Macrí Livia Interdonato Enrico Gugliandolo Claudia Interlandi Rosalia Crupi Ramona DAmico Roberta Fusco Salvatore Cuzzocrea Rosanna Di Paola 《International journal of molecular sciences》2022,23(10)
Endometriosis is usually associated with inflammation and chronic pelvic pain. This paper focuses the attention on the anti-inflammatory, anti-oxidant and analgesic effects of cannabidiol (CBD) and on its potential role in endometriosis. We employed an in vivo model of endometriosis and administered CBD daily by gavage. CBD administration strongly reduced lesions diameter, volume and area. In particular, it was able to modify lesion morphology, reducing epithelial glands and stroma. CBD showed anti-oxidant effects reducing lipid peroxidation, the expression of Nox-1 and Nox-4 enzymes. CBD restored the oxidative equilibrium of the endogenous cellular defense as showed by the SOD activity and the GSH levels in the lesions. CBD also showed important antifibrotic effects as showed by the Masson trichrome staining and by downregulated expression of MMP-9, iNOS and TGF-β. CBD was able to reduce inflammation both in the harvested lesions, as showed by the increased Ikb-α and reduced COX2 cytosolic expressions and reduced NFkB nuclear localization, and in the peritoneal fluids as showed by the decreased TNF-α, PGE2 and IL-1α levels. CBD has important analgesic effects as showed by the reduced mast cells recruitment in the spinal cord and the reduced release of neuro-sensitizing and pro-inflammatory mediators. In conclusion, the collected data showed that CBD has an effective and coordinated effects in endometriosis suppression. 相似文献
164.
Stefanie Ramona Weisenfeld Jana Jakobs Lothar Rink 《Molecular nutrition & food research》2023,67(15):2200772
Scope
Zinc is important for a balanced immune system, but the mechanisms are not yet fully elucidated. One possibility is an interaction of zinc with the tricarboxylic acid cycle (TCA), in which zinc inhibits the mitochondrial aconitase leading to an increase in intracellular citrate concentration as described for prostate cells. Therefore, the immune modulatory effects of zinc and citrate and their interaction in mixed lymphocyte cultures (MLC) are studied.Methods and results
After allogeneic (MLC) or superantigen stimulation, the interferon-γ (IFNγ) production is quantified by ELISA and T cell subpopulations are determined by Western Blot. Intracellular concentrations of citrate and zinc are measured. Zinc and citrate reduce the IFNγ expression and the pro-inflammatory T helper cells (Th) 1 and Th17 in MLC. While zinc increases regulatory T cells, citrate reduces them. After superantigen stimulation IFNγ production is decreased only by citrate but increased by zinc. Zinc does not affect citrate concentration, while citrate impairs zinc uptake. Thus, zinc and citrate independently regulate IFNy expression.Conclusion
These results may explain the immunosuppressive effect of blood products anticoagulated by citrate. In addition, high citrate consumption may lead to immunosuppressive effects, so upper limits for citrate should be established. 相似文献165.
Development and Characterization of a 96-Well Exposure System for Safety Assessment of Nanomaterials
Yvonne Kohl Michelle Müller Marielle Fink Marc Mamier Siegfried Fürtauer Roland Drexel Christine Herrmann Stephan Dähnhardt-Pfeiffer Ramona Hornberger Marius I. Arz Christoph Metzger Sylvia Wagner Sven Sängerlaub Heiko Briesen Florian Meier Tobias Krebs 《Small (Weinheim an der Bergstrasse, Germany)》2023,19(23):2207207
In this study, a 96-well exposure system for safety assessment of nanomaterials is developed and characterized using an air–liquid interface lung epithelial model. This system is designed for sequential nebulization. Distribution studies verify the reproducible distribution over all 96 wells, with lower insert-to-insert variability compared to non-sequential application. With a first set of chemicals (TritonX), drugs (Bortezomib), and nanomaterials (silver nanoparticles and (non-)fluorescent crystalline nanocellulose), sequential exposure studies are performed with human lung epithelial cells followed by quantification of the deposited mass and of cell viability. The developed exposure system offers for the first time the possibility of exposing an air–liquid interface model in a 96-well format, resulting in high-throughput rates, combined with the feature for sequential dosing. This exposure system allows the possibility of creating dose-response curves resulting in the generation of more reliable cell-based assay data for many types of applications, such as safety analysis. In addition to chemicals and drugs, nanomaterials with spherical shapes, but also morphologically more complex nanostructures can be exposed sequentially with high efficiency. This allows new perspectives on in vivo-like and animal-free approaches for chemical and pharmaceutical safety assessment, in line with the 3R principle of replacing and reducing animal experiments. 相似文献