Optical spectroanalyzer with extended dynamic range for pharmacokinetic investigations of photosensitizers in biotissue

Currently, the most promising method for the study of pharmacokinetics of drugs with fluorescent properties is the spectral-fluorescent method. In this article, we propose an algorithm for expanding the dynamic range of the spectrum analyzer by automatically monitoring the maximum spectral density in the recorded fluorescence spectrum and automatically controlled changes in the accumulation time depending on this value, followed by compensation of the output signal with regard to this change, as well as hardware circuit solutions that allow this algorithm.Testing of LESA-01-"Biospeс" spectrum analyzer, upgraded using the proposed approach, was carried out on photosensitizer dispersions based on tetra-3-phenylthiophthalocyanine hydroxyaluminium of various concentrations (from 0.01 mg/l to 50 mg/l), approximately corresponding to the concentrations realized in the process of studying pharmacokinetics in calibration samples and tissues of experimental animals.The proposed solutions that implement the algorithm for recording fluorescence spectra with automatic change of accumulation time depending on the signal level, ensured a significant expansion of the dynamic range of the spectrum analyzer (up to 3.5 orders of magnitude) and improved accuracy in pharmacokinetic studies.

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Broadband Digital Predistortion Utilizing Parallel Quasi- Wiener-Hammerstein Model with Extended Dynamic Range

2021 IEEE MTT-S International Wireless Symposium (IWS) ◽

10.1109/iws52775.2021.9499484 ◽

2021 ◽

Author(s):

Xin Liu ◽

Wenhua Chen ◽

Zhenghe Feng

Keyword(s):

Dynamic Range ◽

Hammerstein Model ◽

Digital Predistortion ◽

Extended Dynamic

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Multi-Bit Sigma Delta ADC with Reduced Feedback Levels, Extended Dynamic Range and Increased Tolerance for Analog Imperfections

2007 IEEE Custom Integrated Circuits Conference ◽

10.1109/cicc.2007.4405685 ◽

2007 ◽

Cited By ~ 6

Author(s):

Jian-Yi Wu ◽

Ahmad Bahai ◽

Raj Subramoniam ◽

Zhenyong Zhang ◽

Ali Djabbari ◽

...

Keyword(s):

Dynamic Range ◽

Sigma Delta ◽

Sigma Delta Adc ◽

Extended Dynamic

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The limitation of the dynamic range of a spectrum analyzer due to nonlinear processes in the mixer

Measurement Techniques ◽

10.1007/s11018-008-9119-9 ◽

2008 ◽

Vol 51 (7) ◽

pp. 786-790 ◽

Cited By ~ 2

Author(s):

I. P. Sivokon’ ◽

S. A. Sinel’nikov

Keyword(s):

Dynamic Range ◽

Spectrum Analyzer ◽

Nonlinear Processes

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Photodetector resistant to background light noise with extended dynamic range of input signals

Технология и конструирование в электронной аппаратуре ◽

10.15222/tkea2021.3-4.03 ◽

2021 ◽

pp. 3-8

Author(s):

V. M. Lipka ◽

V. V. Ryukhtin ◽

Yu. G. Dobrovolsky

Keyword(s):

Dynamic Range ◽

Automatic Gain Control ◽

Modulation Frequency ◽

Low Frequency ◽

Gain Control ◽

Ambient Air ◽

Frequency Range ◽

Background Light ◽

Useful Signal ◽

Extended Dynamic

Measurement of periodic optical information signals in the background light noise with a photodetector with extended dynamic range is an urgent task of modern electronics and thus has become the aim of this study. To increase the dynamic range of the photodetector, a new version of the automatic gain control (AGC) circuit has been developed, which consists of an AGC controller, an output photodetector amplifier and an AGC detector. The authors measured the dynamic range of the photodetector when receiving optical radiation with a wavelength of 1064 nm in the power range from 2.10–8 to 2.10–5 W at a modulation frequency of 20 kHz with the AGC on. Under these conditions, the dynamic range of the photodetector was found to be up to 67 dB. If the AGC was off, the dynamic range did not exceed 30 dB. Thus, the study made it possible to create a photodetector with an extended dynamic range up to 67 dB based on a new version of the AGC circuit. The design of the photodetector allowed choosing a useful signal of a particular modulation frequency in the frequency range from 3 to 45 kHz and effectively suppresses the frequencies caused by optical interference in the low frequency range from the frequency of the input signal of constant amplitude up to 3 kHz inclusive. This compensates the current up to 15 mA, which is equivalent to the power of light interference of about 15 mW. Further research should address the issues of reliability of the proposed photodetector design and optimization of its optical system. The photodetector can be used in geodesy and ambient air quality monitoring.

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FBG-Embedded Oblong Diaphragms with Extended Dynamic Range

IEEE Sensors Letters ◽

10.1109/lsens.2018.2822875 ◽

2018 ◽

Vol 2 (2) ◽

pp. 1-4 ◽

Cited By ~ 2

Author(s):

Arnaldo G. Leal-Junior ◽

Anselmo Frizera ◽

Camilo R. Diaz ◽

Moises R. N. Ribeiro ◽

Maria Jose Pontes

Keyword(s):

Dynamic Range ◽

Extended Dynamic

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Quantification and Brain Targeting of Eugenol-Loaded Surface Modified Nanoparticles Through Intranasal Route in the Treatment of Cerebral Ischemia

Drug Research ◽

10.1055/a-0596-7288 ◽

2018 ◽

Vol 68 (10) ◽

pp. 584-595 ◽

Cited By ~ 21

Author(s):

Niyaz Ahmad ◽

Rizwan Ahmad ◽

Md Alam ◽

Farhan Ahmad

Keyword(s):

Cerebral Ischemia ◽

Rat Brain ◽

Dynamic Range ◽

Internal Standard ◽

Drug Uptake ◽

Brain Targeting ◽

Pharmacokinetic Studies ◽

Drug Bioavailability ◽

Elution Time

Abstract Objective To enhance brain bioavailability for intranasally administered Eugenol-encapsulated-chitosan-coated-PCL-Nanoparticles (CS-EUG-PCL-NPs). Methods Chitosan-coated-PCL-Nanoparticles (CS-PCL-NPs) were developed through double emulsification-solvent evaporation technique and further characterized for particle size, zeta potential, size distribution, encapsulation efficiency as well as in vitro drug release. UPLC-PDA method was developed to evaluate brain-drug uptake for optimized CS-EUG-PCL-NPs and to determine it’s pharmacokinetic in rat’s brain as well as plasma. Results Mean particles size (224.5±5.31), polydispersity index (PDI) i. e. (0.216±0.020) and entrapment efficiency (68.13±5.03) was determined for developed NPs. UPLC-PDA-eλ study showed a significantly high mucoadhesive potential of CS-EUG-PCL-NPs and least for conventional and homogenized nanoformulation; elution time for EUG and internal standard (IS) thymoquinone as 3.50 and 3.61 min were observed respectively. Furthermore, intra and inter-assay (%CV) of 0.25–1.57, %accuracy (97.11-99.00%) as well as a linear dynamic range (100.00 ng/mL–2500.0 ng/mL), was observed. Pharmacokinetic studies in Wistar rat brain and plasma exhibited a high AUC0-24 alongwith an amplified Cmax (p**<0.01) as compared to i. v. treated group. Conclusions Intranasal administration of developed CS-coated-EUG-loaded-PCL-NPs enhanced the drug bioavailability in rat brain and thus preparation of Eugenol-NPs may help treat cerebral ischemia effectively. The toxicity studies performed at the end revealed safe nature of optimized nanoformulation.

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