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排序方式: 共有2553条查询结果,搜索用时 15 毫秒
51.
Susanne Jung Marco Maria Moser Johannes Kleinheinz Arndt Happe 《International journal of molecular sciences》2021,22(14)
Gingivafibroblasts were cultured on lithium disilicate, on zirconia dioxide, and on titanium with two different surface roughnesses (0.2 µm and 0.07 µm); Proliferation (MTT), Living/Dead staining, cytotoxicity (LDH), proliferation (FGF2), and inflammation (TNFα) were analyzed after 1 day and 21 days. Furthermore, alteration in cell morphology (SEM) was analyzed. The statistical analysis was performed by a Kruskal–Wallis test. The level of significance was set at p < 0.05. There were no distinct differences in cellular behavior between the tested roughness. There were slight differences between tested materials. Cells grown on zirconia dioxide showed higher cytotoxic effects. Cells grown on lithium disilicate showed less expression of TNFα compared to those grown on zirconia dioxide or titanium. These effects persisted only during the first time span. The results indicate that the two tested high-strength ceramics and surface properties are biologically suitable for transmucosal implant components. The findings may help clinicians to choose the most appropriate biomaterial as well as the most appropriate surface treatment to use in accordance with specific clinical dental applications. 相似文献
52.
Adam Chojecki Hervé Jobic Andreas Jentys Thomas E. Müller Johannes A. Lercher 《Catalysis Letters》2004,97(3-4):155-162
Inelastic Neutron Scattering (INS) spectroscopy was used to characterize the catalytic hydrogenation of butyronitrile on the surface of parent and LiOH-modified Raney-Co. At low pressure hydrogen is mainly adsorbed on 3-fold sites. Co-adsorbed butyronitrile and hydrogen react on the unmodified Raney-Co sample to several partially hydrogenated products that contain N-H bonds. The nature of the species suggests that bi-molecular condensation leading to N-Butylidene-1-butanamine is feasible. 相似文献
53.
Diana Belschner Melanie Rosenberger Dr. Zeynep Atamer Jörg Hinrichs Thomas Kosian Johannes Rauschnabel 《化学,工程师,技术》2023,95(6):934-943
The aim of the present study was to evaluate the concentration of sodium pyruvate in growth media by using the most-probable number method to decompose carried-over liquid hydrogen peroxide (H2O2) without negative influences on correct enumeration of Geobacillus stearothermophilus spores. An equivalent molar ratio of sodium pyruvate and H2O2 was verified to be sufficient for a complete decomposition. The results showed that by exposition of G. stearothermophilus spores in different liquid hydrogen peroxide and by carry-over of concentrations ranging from 3.56 · 10−6 up to 1.69 · 10−4 mol, a sodium pyruvate concentration of 0.05 mol L−1 in growth media was most efficient for the recovery of spores. 相似文献
54.
Johannes Neukäufer Mohamed Adel Ashour Nadin Sarajlic Harald Klein Sebastian Rehfeldt Heiko Hallmann Sebastian Meinicke Jürgen Paschold Carsten Knösche Thomas Grützner 《American Institute of Chemical Engineers》2023,69(3):e17902
This publication presents a general approach for the enhancement of packings regarding scalability, separation efficiency, and fluid dynamic properties using three-dimensional (3D) printing. The methodology is used to develop miniaturized, scalable packings for process development, and scale-up applications. For this purpose, a 3D printable computer-aided design version of the Rombopak 9M industrial packing (RP9M-3D), which is known for its positive scalability properties, was created. An initial characterization by means of computational fluid dynamics simulations and mass transfer measurements reveals positive but also negative design properties. These findings are used to create a more advanced, miniaturized packing structure, the XW-Pak. The evolved structure is compared to the RP9M-3D. The simulation and experimental results show that the enhanced packing, which is still in the early stages of development, exhibits higher separation efficiencies with improved scalability properties at the same void fraction and surface area than the RP9M-3D. 相似文献
55.
Katja Lerch Prof. Dr.‐Ing. Jörg Hinrichs Patrizia Dittmer Dr. Johannes Rauschnabel 《化学,工程师,技术》2013,85(3):323-332
Falling films in wash down process are of major interest for pharmaceutical isolators, which are used for processing of highly potent pharmaceutical products. In this study multiple process parameters were examined with common materials of isolator systems. The importance of material and surface finish in respect of cleanability and complete wetting as well as a combination of process parameters are presented and discussed. For cleaning validation an effect of high interest was discovered: swab sampling areas changed their properties over many repeated cycles and showed decreased cleanability. 相似文献
56.
Johannes C. Jansen Marialuigia Macchione Raniero Mendichi Enrico Drioli 《Polymer》2005,46(25):11366-11379
Asymmetric gas separation membranes were prepared by the dry-casting technique from PEEKWC, a modified amorphous glassy poly(ether ether ketone). The phase inversion process and membrane performance were correlated to the properties of the polymer and the casting solution (molar mass, polymer concentration, solution rheology and thermodynamics). It was found that a broad molar mass distribution of the polymer in the casting solution is most favourable for the formation of a highly selective membrane with a dense skin and a porous sub-layer. Thus, membranes with an effective skin thickness of less than 1 μm were obtained, exhibiting a maximum O2/N2 selectivity of 7.2 and a CO2/CH4 selectivity of 39, both significantly higher than in a corresponding thick dense PEEKWC membrane and also comparable to or higher than that of the most commonly used polymers for gas separation membranes. The CO2 and O2 permeance were up to 9.5×10−3 and 1.8×10−3 m3/(m2 h bar) (3.5 and 0.67 GPU), respectively. 相似文献
57.
58.
Wadman MW van Zadelhoff G Hamberg M Visser T Veldink GA Vliegenthart JF 《Lipids》2005,40(11):1163-1170
Oxylipins are associated with important processes of the fungal life cycle, such as spore formation. Here, we report the formation
of FA metabolites in Agaricus bisporus. Incubation of a crude extract of lamellae with linoleic acid (18∶2) led to the extensive formation of two oxylipins. They
were identified as 8(R)-hydroxy-9Z,12Z-octadecadienoic acid (8-HOD) and 8(R),11(S)-dihydroxy-9Z,12Z-octadecadienoic acid (8,11-diHOD) by using RP-HPLC, GC-MS, IR, GC-MS analysis of diastereomeric derivatives, and 1H NMR and 13C NMR spectroscopy. Neither compound has been reported before in A. bisporus. Oleic (18∶1), α-linolenic (18∶3n−3), and γ-linolenic (18∶3n−6) acids were converted into their 8-hydroxy derivatives as
well, and 18∶3n−3 was further metabolized to its 8,11-diol derivative. Reactions with [U-13C]18∶2 demonstrated that the compounds 8-HOD and 8,11-diHOD were formed from exogenously supplied 18∶2. When [U-13C]8-HOD was supplied, it was not converted into 8,11-diHOD, indicating that it was not an intermediate in the formation of
8,11-diHOD. When a crude extract of A. bisporus was incubated under an atmosphere of 16O2/18O2, the two hydroxyl groups of 8,11-diHOD contained either two 18O atoms or two 16O atoms. Species that contained one of each isotope could not be detected. We propose that the formation of the 8,11-dihydroxy
compounds occurs through either an 8,11-endoperoxy, an 8-peroxo free radical, or an 8-hydroperoxy intermediate. In the latter
case, the reaction should be catalyzed by dioxygenase with novel specificity. 相似文献
59.
Patrick Otto Ludl Raoul Heese Johannes Höller Norbert Asprion Michael Bortz 《Frontiers of Chemical Science and Engineering》2022,16(2):183-197
Flowsheet simulations of chemical processes on an industrial scale require the solution of large systems of nonlinear equations,so that solvability becomes a practical issue.Additional constraints from technical,economic,environmental,and safety considerations may further limit the feasible solution space beyond the convergence requirement.A priori,the design variable domains for which a simulation converges and fulfills the imposed constraints are usually unknown and it can become very time-consuming to distinguish feasible from infeasible design variable choices by simply running the simulation for each choice.To support the exploration of the design variable space for such scenarios,an adaptive sampling technique based on machine learning models has recently been proposed.However,that approach only considers the exploration of the convergent domain and ignores additional constraints.In this paper,we present an improvement which particularly takes the fulfillment of constraints into account.We successfully apply the proposed algorithm to a toy example in up to 20 dimensions and to an industrially relevant flowsheet simulation. 相似文献
60.
Tatiana S. Driva Christoph Schatz Monika Sobo
an Johannes Haybaeck 《International journal of molecular sciences》2022,23(7)
Adenomyosis, endometriosis, endometritis, and typical endometrial hyperplasia are common non-cancerous diseases of the endometrium that afflict many women with life-impacting consequences. The mammalian target of the rapamycin (mTOR) pathway interacts with estrogen signaling and is known to be dysregulated in endometrial cancer. Based on this knowledge, we attempt to investigate the role of mTOR signaling in benign endometrial diseases while focusing on how the interplay between mTOR and eukaryotic translation initiation factors (eIFs) affects their development. In fact, mTOR overactivity is apparent in adenomyosis, endometriosis, and typical endometrial hyperplasia, where it promotes endometrial cell proliferation and invasiveness. Recent data show aberrant expression of various components of the mTOR pathway in both eutopic and ectopic endometrium of patients with adenomyosis or endometriosis and in hyperplastic endometrium as well. Moreover, studies on endometritis show that derangement of mTOR signaling is linked to the establishment of endometrial dysfunction caused by chronic inflammation. This review shows that inhibition of the mTOR pathway has a promising therapeutic effect in benign endometrial conditions, concluding that mTOR signaling dysregulation plays a critical part in their pathogenesis. 相似文献