Using the National Institute of Standards and Technology high-accuracy cryogenic radiometer (HACR), we have realized a scale of absolute spectral response between 406 and 920 nm. The HACR, an electrical-substitution radiometer operating at cryogenic temperatures, achieves a combined relative standard uncertainty of 0.021%. Silicon photodiode light-trapping detectors were calibrated against the HACR with a typical relative standard uncertainty of 0.03% at nine laser wavelengths between 406 and 920 nm. Modeling of the quantum efficiency of these detectors yields their responsivity throughout this range with comparable accuracy. 相似文献
CBS encodes a pyridoxal 5′-phosphate-dependent enzyme that catalyses the condensation of homocysteine and serine to form cystathionine. Due to its implication in some cancers and in the cognitive pathophysiology of Down syndrome, the identification of pharmacological inhibitors of this enzyme is urgently required. However, thus far, attempts to identify such molecules have only led to the identification of compounds with low potency and limited selectivity. We consequently developed an original, yeast-based screening method that identified three FDA-approved drugs of the 8-hydroxyquinoline family: clioquinol, chloroxine and nitroxoline. These molecules reduce CBS enzymatic activity in different cellular models, proving that the molecular mechanisms involved in yeast phenotypic rescue are conserved in mammalian cells. A combination of genetic and chemical biology approaches also revealed the importance of copper and zinc intracellular levels in the regulation of CBS enzymatic activity—copper promoting CBS activity and zinc inhibiting its activity. Taken together, these results indicate that our effective screening approach identified three new potent CBS inhibitors and provides new findings for the regulation of CBS activity, which is crucial to develop new therapies for CBS-related human disorders. 相似文献
A coating technology based on low molecular weight hyaluronic acid (HA) and ferulic acid (FA) was applied to the coating of low generation poly(propylene imine) dendrimers through a biocompatible hexa(ethylene glycol) spacer. The ensuing HA-FA-HEG-PPID dendrimeric materials showed interesting loading capability (between 7.65% and 9.08%) regarding anticancer agent doxorubicin, and their interactions with the drug appeared to hamper the drug release in the physiological environment. Thus, the stable nanostructured loaded delivery systems were able to internalize into cells expressing the HA receptor CD44 and to demonstrate high cytotoxicity comparable to that shown by equivalent amounts of free doxorubicin. Thus, HA-FA-HEG-PPID dendrimeric materials were proposed as biocompatible drug carriers capable of transporting anticancer doxorubicin to tumor cells. 相似文献
The robotic process automation (RPA) paradigm is a discipline that is becoming increasingly popular thanks to the great interest shown by the industry. In such context, RPA solutions based on artificial intelligence, i.e., cognitive solutions, are receiving increasing attention. In a cognitive RPA project, the RPA developer is in charge of selecting the most suitable components that solve specific tasks from the sets of components provided by different RPA platforms. This selection is very challenging, especially since there is no homogeneity in component names or component classifications. Such a situation turns an RPA project’s development into a time-consuming, error-prone, and very tedious process. Therefore, supporting the RPA developer in developing a cognitive RPA project is desired. The industry has also pointed out this need. This work presents a proposal for supporting the users in developing a cognitive RPA project. To be more precise, an incremental method to automatically generate taxonomies from cognitive RPA platforms is proposed. Such taxonomies can be dynamically adapted when necessary. In previous work, the initial aspects of this research were presented. However, the current work greatly enhances such previous work by: (1) extending the proposed method to improve the management of real-world use cases from industry, (2) developing a proof-of-concept tool that is based on the proposed approach, (3) validating the proposed method by applying it to real-world use cases from industry, and (4) performing a literature review on related topics. The results obtained are auspicious and demonstrate that the proposed approach substantially improves the support given to users during the development of a cognitive RPA project.
Conducting polymers show attractive characteristics as electrode materials for micro-electrochemical energy storage (MEES). However, there is a lack of characterization techniques to study conjugated/conducting polymer-based nanostructured electrodes. Here, scanning electrochemical microscopy (SECM) is introduced as a new technique for in situ characterization and acceleration of degradation processes of conducting polymers. Electrodes of PEDOT:PSS on flat silicon, silicon nanowires (SiNWs) and silicon nanotrees (SiNTrs) are analyzed by SECM in feedback mode with approach curves and chronoamperometry. The innovative degradation method using SECM reduces the time required to locally degrade polymer samples to a few thousand seconds, which is significantly shorter than the time usually required for such studies. The degradation rate is modeled using Comsol Multiphysics. The model provides an understanding of the phenomena that occur during degradation of the polymer electrode and describes them using a mathematical constant A0 and a time constant τ. 相似文献
The purpose of this study was to investigate of structural changes induced in apple texture upon dehydration with classical methods, as freeze-drying and convective-air drying, compared to apples dried by packaging in innovative films based on natural polysaccharides. ESEM microscopy was used to detect structural changes. Our studies has shown that apples obtained by freeze-drying had a more broken tissue texture, and that the composition of the films has an effect both on structure and re-hydration kinetics. Olfactory characteristics of the different dried apples were also investigated by using an electronic nose device and compared with tissue texture properties. Apples that have shown the most intact cell walls are those that better retain olfactory properties. 相似文献