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101.
Marijan Marijan Anamarija Mitar Lejsa Jakupovi Jasna Prli Kardum Marijana Zovko Kon
i 《Molecules (Basel, Switzerland)》2022,27(2)
Olive leaf is a rich source of phenolic compounds with numerous activities related to skin health and appearance. In this study, a green extraction method was developed using eco-friendly solvents: polypropylene glycol (PPG), lactic acid (LA), and water. The optimal extraction conditions were established, including solvent, extraction time, technique (magnetic stirrer vs. ultrasound-assisted extraction), and herbal material/solvent ratio. The composition of the solvent mixture was optimized using a mixture design. The content of phenolic compounds, including oleuropein and verbascoside, was determined using high-performance liquid chromatography (HPLC) and spectrophotometric methods. Using different extraction conditions, three extracts were prepared and their phytochemical compositions and antioxidant and skin-related bioactivities were investigated. The extracts were excellent inhibitors of elastase, collagenase, tyrosinase, and lipoxygenase. The best activity was shown by the extract richest in phenolics and prepared using magnetic-stirrer-assisted extraction for 20 min, with 0.8 g of herbal material extracted in 10 mL of PPG/LA/water mixture (28.6/63.6/7.8, w/w/w), closely followed by the extract prepared using the same extraction conditions but with 0.42 g of herbal material. The investigated PPG/LA/water mixtures contributed to the overall enzyme-inhibitory activity of the extracts. The prepared extracts were appropriate for direct use in cosmetic products, thus saving the time and energy consumption necessary for the evaporation of conventional solvents. 相似文献
102.
A simple light-sensitive CMOS ring oscillator, the oscillation frequency of which depends on the chip ambient illumination, is presented. An experimental 21-stage ring oscillator fabricated in 0.5 μm CMOS changes the pulse frequency from 50 Hz in total darkness to 2 MHz in extreme bright ambient at Vdd=1 V 相似文献
103.
Milena Rmandi Ana Staji Jasna Jan
i Janko Samardi Neboja Jovi Anelija Malenovi 《Molecules (Basel, Switzerland)》2022,27(15)
In this research, a UHPLC–MS/MS method was developed and validated for the determination of zonisamide in dried plasma spots (DPS) and dried blood spots (DBS). Detection of zonisamide and internal standard, 1-(2,3-dichlorphenyl)piperazine, was carried out in ESI+ mode by monitoring two MRM transitions per analyte. Total run time, less than 2.5 min, was achieved using Acquity UPLC BEH Amide (2.1 × 100 mm, 1.7 µm particle size) column with mobile phase comprising acetonitrile–water (85:15%, v/v) with 0.075% formic acid. The flow rate was 0.225 mL/min, the column temperature was 30 °C and the injection volume was 3 µL. Desolvation temperature, desolvation gas flow rate, ion source temperature and cone gas flow rate were set by the IntelliStart software tool in combination with tuning. All of the Guthrie cards were scanned, and DPS/DBS areas were determined by the image processing tool. The influence of hematocrit values (20–60%) on accuracy and precision was evaluated to determine the range within which method for DBSs is free from Hct or dependency is within acceptable limits. The validated method was applied to the determination of zonisamide levels in DPS and DBS samples obtained from patients confirming its suitability for clinical application. Finally, the distribution of zonisamide into the red blood cells was estimated by correlating its DPS and DBS levels. 相似文献
104.
105.
Nadja Frömmgen Dimiter L. Balabanski Mark L. Bissell Jacek Bieroń Klaus Blaum Bradley Cheal Kieran Flanagan Stephan Fritzsche Christopher Geppert Michael Hammen Magdalena Kowalska Kim Kreim Andreas Krieger Rainer Neugart Gerda Neyens Mustafa M. Rajabali Wilfried Nörtershäuser Jasna Papuga Deyan T. Yordanov 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2015,69(6):164
106.
107.
Reconstructing free energy profiles is an important problem in bimolecular reactions, protein folding or allosteric conformational
changes. Nonequilibrium trajectories are readily measured experimentally, but their statistical significance and relation
to equilibrium system properties still call for rigorous methods of assessment and interpretation. Here we introduce methods
to compute the equilibrium free energy profile of a given variable from a set of short nonequilibrium trajectories, obtained
by externally driving a system out of equilibrium and subsequently observing its relaxation. This protocol is not suitable
for the Jarzynski equality since the irreversible work on the system is instantaneous. Assuming that the variable of interest
satisfies an overdamped Langevin equation, which is frequently used for modeling biomolecular processes, we show that the
trajectories sample a nonequilibrium stationary distribution that can be calculated in closed form. This allows for the estimation
of the free energy via an inversion procedure that is analogous to that used in equilibrium and bypasses more complicated
path integral methods, which we derive for comparison. We generalize the inversion procedure to systems with a diffusion constant
that depends on the reaction coordinate, as is the case in protein folding, as well as to protocols in which the trajectories
are initiated at random points. Using only a statistical pool of tens of synthetic trajectories, we demonstrate the versatility
of these methods by reconstructing double and multi-well potentials, as well as a proposed profile for the hydrophobic collapse
of a protein. 相似文献
108.
Switching between states in a dispersive bistable injection-locked slave laser has been theoretically investigated. We show that the switching can be achieved by relatively small and short (≈10-50?ps) variation of the master laser injection power or frequency, which, besides the variation of the slave laser optical power, leads to significant variation of its photon phase (≈5π/6). By using an analytical model, we calculate the switching time dependence on the magnitude of the injection power and the frequency detuning variation. 相似文献
109.
An HPLC/MS/MS method has been developed and validated for the quantification and confirmation of nicarbazin and ionophores (lasalocid, monensin, salinomycin, and narasin) in eggs. Nicarbazin is determined in the negative electrospray mode with a basic mobile phase that supports creation of negative ions. Consequently, our ability to maintain instrument sensitivity over time has significantly improved. The analysis of the ionophores is done in the positive electrospray mode using ammonium buffer for HPLC separation. Monitoring ammonium adduct parent ions resulted in enhanced sensitivity and better reproducibility of the ionophore analysis. The validation of this improved HPLC/MS/MS method for the detection of nicarbazin and the ionophores demonstrated excellent precision of below 10% RSD and lower LOD values (microg/kg) for nicarbazin (0.018), lasalocid (0.015), monensin (0.015), salinomycin (0.033), and narasin (0.039). 相似文献
110.
Nebojsa Jankovic Zhongfu Zhou Steve Batcup Petar Igic 《International Journal of Electronics》2013,100(7):767-779
An advanced sub-circuit model of the punch-trough insulated gate bipolar transistor (PT IGBT) based on the physics of internal device operation has been described in this article. The one-dimensional physical model of low-gain wide-base BJT is employed based on the equivalent non-linear lossy transmission line, whereas a SPICE Level 3 model is used for the diffused MOST part. The influence of voltage dependent drain-to-gate overlapping capacitance and the conductivity modulated base (drain) ohmic resistance are modelled separately. The main advantages of novel PT IGBT model are a small set of model parameters, an easy implementation in SPICE simulator and the high accuracy confirmed by comparing the simulation results with the electrical measurements of test power circuit. 相似文献