Comparative modeling of microwave and ultrasound assisted extraction of phenolics and berberine from Coptis teeta Wall. rhizomes

Coptis teeta rhizomes are a rich source of bioactive phytochemicals with significant applications in the food and nutraceutical industries. Standardized methods and solvent compositions are crucial to sustainably maximize bioactive yield while ensuring industrial feasibility. This study models and compares microwave (MAE) and ultrasound (UAE) assisted extraction of phenolics and berberine – the primary active alkaloid in Coptis teeta rhizomes. Previous studies on extracting phytochemicals from Coptis teeta have relied on the central composite design, which is limited in handling multiple independent variables. To address this limitation, a Box–Behnken design along with a response surface method was utilized, where independent variables included the solvent concentration (water[thin space (1/6-em)]:[thin space (1/6-em)]methanol), power level, extraction time, and solid–liquid ratio, and dependent variables were total phenolic content (TPC) and antioxidant activity. The results showed that for MAE, using 65% solvent concentration, 310 W power, 30 min extraction time, and 1[thin space (1/6-em)]:[thin space (1/6-em)]39 g mL−1 solid–liquid ratio resulted in a TPC of 210.04 mg GAE 100 g−1 and antioxidant activity of 98.57%. Whereas for UAE, 36% solvent concentration, 160 W ultrasound power, 10 min extraction time, and 1[thin space (1/6-em)]:[thin space (1/6-em)]78 g mL−1 solid–liquid ratio resulted in a TPC of 251.11 mg GAE 100 g−1 and 97.82% antioxidant activity. Berberine concentration in MAE extract was 212.18 ppm, whereas it was 162.96 ppm in UAE extract. While MAE yielded a higher berberine content, UAE was superior in extracting total phenolics. The findings provide a foundation for developing standardized methods and solvent compositions suitable for food and nutraceutical formulations

How to compute a special function with near machine-precision accuracy

Based on my experience as developer and maintainer of some numerical open-source libraries (libcerf, libkww, libformfactor), I will explain key concepts for writing code that computes a special function or integral with high accuracy and high speed.- Choose different numerical algorithms for different argument regions.- Don't be afraid of divergent series or ill-conditioned recursions. - Confine Chebyshev fits to small subregions. - Use code instrumentation and bisection to ensure continuity where the algorithm changes. - Beware of literature that is only concerned with truncation. Near machine precision, cancellation is the bigger problem. Visualization may reveal the difference. - Never rely on non-standard facilities. "Long double" makes no sense if it is not longer than "double"? Tell Apple. - Generate test references and hard-coded coefficients with high-precision scripts (e.g. mpmath based). - Be graceful with relative accuracy measures near zeros and for real or imaginary parts of complex numbers.- Don't trust any performance measure you haven't tweaked yourself. Take caching into account

Soft phonon and the central peak at the cubic-to-tetragonal phase transition in SrTiO3_{3}

The continuous displacive phase transition in SrTiO3 near ≈105 K features a central elastic peak in neutron-scattering investigations at temperatures above , i.e., before the corresponding soft phonon mode is overdamped upon cooling. The origin of this central peak is still not understood. Here, we report an inelastic x-ray scattering investigation of the cubic-to-tetragonal phase transition in SrTiO3. We compare quantitatively measurements of the soft phonon mode on two differently grown samples and discuss the findings regarding results from thermodynamic and transport probes such as specific heat and thermal conductivity. Furthermore, we use inelastic x-ray scattering to perform elastic scans with both high momentum and milli-electronvolt energy-resolution and, thus, are able to separate elastic intensities of the central peak from low-energy quasielastic phonon scattering. Our results indicate that the evolution of the soft mode is similar in both samples though the intensities of the central peak differ by a factor of four. Measurements revealing anisotropic correlation lengths on cooling towards , indicate that local properties of the crystals to which collective lattice excitations are insensitive are likely at the origin of the central elastic line in SrTiO3

A high-frequency artificial nerve based on homogeneously integrated organic electrochemical transistors

Artificial nerves that are capable of sensing, processing and memory functions at bio-realistic frequencies are of potential use in nerve repair and brain–machine interfaces. n-type organic electrochemical transistors are a possible building block for artificial nerves, as their positive-potential-triggered potentiation behaviour can mimic that of biological cells. However, the devices are limited by weak ionic and electronic transport and storage properties, which leads to poor volatile and non-volatile performance and, in particular, a slow response. We describe a high-frequency artificial nerve based on homogeneously integrated organic electrochemical transistors. We fabricate a vertical n-type organic electrochemical transistor with a gradient-intermixed bicontinuous structure that simultaneously enhances the ionic and electronic transport and the ion storage. The transistor exhibits a volatile response of 27 μs, a 100-kHz non-volatile memory frequency and a long state-retention time. Our integrated artificial nerve, which contains vertical n-type and p-type organic electrochemical transistors, offers sensing, processing and memory functions in the high-frequency domain. We also show that the artificial nerve can be integrated into animal models with compromised neural functions and that it can mimic basic conditioned reflex behaviour

From structure to electrochemistry: the influence of transition metal ordering on Na+^{+} /vacancy orderings in P2-type Nax_{x}MO2_{2} cathode materials for sodium-ion batteries

P2-type layered oxides are attractive cathode active materials for sodium-ion batteries, however, these materials typically suffer from detrimental Na+/vacancy orderings. In this work, we investigate the origin as well as the influence of the transition metal ratio on Na+/vacancy orderings in P2-type cathode materials. A combination of X-ray diffraction (XRD), neutron diffraction, advanced electrochemical methods, operando XRD and DFT calculations is applied to study Na+/vacancy orderings in P2-NaxNi1/3Mn2/3O2 and P2-NaxMn3/4Ni1/4O2. In P2-NaxNi1/3Mn2/3O2, a honeycomb Ni/Mn superstructure leads to charge ordering within the transition metal slab and pronounced Na+/vacancy orderings, causing distinct voltage jumps at specific sodium contents (x = 2/3, 1/2 and 1/3). For P2-Na0.60Mn3/4Ni1/4O2, the Ni/Mn superstructure is disrupted, resulting in more complex charge orderings within the transition metal slab, partially suppressed Na+/vacancy orderings and an overall smoother potential profile. Based on our findings, guidelines to suppress Na+/vacancy orderings in P2-type cathode materials for sodium-ion batteries are postulated and discussed with respect to electrochemical measurements of various transition metal compositions. These guidelines can serve to predict the tendency towards Na+/vacancy orderings for a given cathode composition or to design new cathode compositions for enhanced cycle life based on the absence of Na+/vacancy orderings

PrIcosa: High-Precision 3D Camera Calibration with Non-Overlapping Field of Views

Multi-camera systems are being used more and more frequently, from autonomous mobile robots to intelligentvisual servoing cells. Determining the pose of the cameras to each other very accurately is essential for manyapplications. However, choosing the most suitable calibration object geometry and utilizing it as effectivelyas possible still remains challenging. Disadvantageous geometries provide only subpar datasets, increasingthe need for a larger dataset and decreasing the accuracy of the calibration results. Moreover, an unrefinedcalibration method can lead to worse accuracies even with a good dataset. Here, we introduce a probabilisticmethod to increase the accuracy of 3D camera calibration. Furthermore, we analyze the effects of the calibrationobject geometry on the data properties and the resulting calibration accuracy for the geometries cube andicosahedron. The source code for this project is available at GitHub