A Novel DSP-Based MPPT Control Design for Photovoltaic Systems Using Neural Network Compensator

In this study, based on the slope of power versus voltage, a novel maximum-power-point tracking algorithm using a neural network compensator was proposed and implemented on a TI TMS320F28335 digital signal processing chip, which can easily process the input signals conversion and the complex floating-point computation on the neural network of the proposed control scheme. Because the output power of the photovoltaic system is a function of the solar irradiation, cell temperature, and characteristics of the photovoltaic array, the analytic solution for obtaining the maximum power is difficult to obtain due to its complexity, nonlinearity, and uncertainties of parameters. The innovation of this work is to obtain the maximum power of the photovoltaic system using a neural network with the idea of transferring the maximum-power-point tracking problem into a proportional-integral current control problem despite the variation in solar irradiation, cell temperature, and the electrical load characteristics. The current controller parameters are determined via a genetic algorithm for finding the controller parameters by the minimization of a complicatedly nonlinear performance index function. The experimental result shows the output power of the photovoltaic system, which consists of the series connection of two 155-W TYN-155S5 modules, is 267.42 W at certain solar irradiation and ambient temperature. From the simulation and experimental results, the validity of the proposed controller was verified.

Novel Photosensitizer β-Mannose-Conjugated Chlorin e6 as a Potent Anticancer Agent for Human Glioblastoma U251 Cells

A photosensitizer is a molecular drug for photodynamic diagnosis and photodynamic therapy (PDT) against cancer. Many studies have developed photosensitizers, but improvements in their cost, efficacy, and side effects are needed for better PDT of patients. In the present study, we developed a novel photosensitizer β-mannose-conjugated chlorin e6 (β-M-Ce6) and investigated its PDT effects in human glioblastoma U251 cells. U251 cells were incubated with β-M-Ce6, followed by laser irradiation. Cell viability was determined using the Cell Counting Kit-8 assay. The PDT effects of β-M-Ce6 were compared with those of talaporfin sodium (TS) and our previously reported photosensitizer β-glucose-conjugated chlorin e6 (β-G-Ce6). Cellular uptake of each photosensitizer and subcellular distribution were analyzed by fluorescence microscopy. β-M-Ce6 showed 1000× more potent PDT effects than those of TS, and these were similar to those of β-G-Ce6. β-M-Ce6 accumulation in U251 cells was much faster than TS accumulation and distributed to several organelles such as the Golgi apparatus, mitochondria, and lysosomes. This rapid cellular uptake was inhibited by low temperature, which suggested that β-M-Ce6 uptake uses biological machinery. β-M-Ce6 showed potent PDT anti-cancer effects compared with clinically approved TS, which is a possible candidate as a next generation photosensitizer in cancer therapy.

High frequency acoustic cell stimulation promotes exosome generation regulated by a calcium-dependent mechanism

Exosomes are promising disease diagnostic markers and drug delivery vehicles, although their use in practice is limited by insufficient homogeneous quantities that can be produced. We reveal that exposing cells to high frequency acoustic irradiation stimulates their generation without detriment to cell viability by exploiting their innate membrane repair mechanism, wherein the enhanced recruitment of calcium ions from the extracellular milieu into the cells triggers an ESCRT pathway known to orchestrate exosomal production. Given the high post-irradiation cell viabilities (≈95%), we are able to recycle the cells through iterative irradiation and post-excitation incubation steps, which facilitate high throughput production of a homogeneous population of exosomes—a particular challenge for translating exosome therapy into clinical practice. In particular, we show that approximately eight- to ten-fold enrichment in the number of exosomes produced can be achieved with just 7 cycles over 280 mins, equivalent to a yield of around 1.7–2.1-fold/h.

Effects of photobiomodulation on the redox state of healthy and cancer cells

Photobiomodulation (PBM) uses light to stimulate cells. The molecular basis of the effects of PBM is being unveiled, but it is stated that the cytochrome-c oxidase enzyme in mitochondria, a photon acceptor of PBM, contributes to an increase in ATP production and modulates the reduction and oxidation of electron carriers NADH and FAD. As it can stimulate cells, PBM is not used on tumors. Thus, it is interesting to investigate if its effects correlate to mitochondrial metabolism and if so, how it could be linked to the optical redox ratio (ORR). To that end, fibroblasts and oral cancer cells were irradiated with a light source of 780 nm and a total dose of 5 J/cm2, and imaged by optical microscopy. PBM down-regulated the SCC-25 ORR by 10%. Furthermore, PBM led to an increase in ROS and ATP production in cancer cells after 4 h, while fibroblasts only had a modest ATP increase 6 h after irradiation. Cell lines did not show distinct cell cycle profiles, as both had an increase in G2/M cells. This study indicates that PBM shifts the redox state of oral cancer cells towards glycolysis and affects normal and tumor cells through distinct pathways. To our knowledge, this is the first study that investigated the effects of PBM on mitochondrial metabolism from the initiation of the cascade to DNA replication. This is an essential step in the investigation of the mechanism of action of PBM in an effort to avoid misinterpretations of a variety of combined protocols.

Viability Test of Photodynamic Therapy with Diode Laser Waves Length 405 nm on BHK-21 Fibroblast Cells with Various Irradiation Distances

Background: Photodynamic therapy has now become popular, but its cytotoxic effect is still unclear. In order to be considered suitable for oral cavity therapy, the therapy must not be toxic or cause adverse effects on the target tissue. Viability testing for photodynamic therapy is important to do. Fibroblast cells are often used for testing the toxicity of dentistry because they are the most important cells in the components of the pulp, periodontal ligament, and gingiva. Purpose: To prove the effect of irradiation distance on photodynamic therapy on the viability of BHK-21 fibroblast cells. Method: Viability test was performed with BHK-21 fibroblast cells placed on a 96 well microplate which was then irradiated with 405 nm photodynamic therapy with varying irradiation distances of 1, 4, 7, 10, 13, and 16 mm. After irradiation, cell viability was tested by MTT assay and ELISA Reader. Data were analyzed using Kolmogorov-Smirnov, Levene’s test, Kruskall Wallis, and Tukey HSD. Result: Fibroblast cells with 4 mm irradiation distance have viability over control cells, whereas at irradiation distances 1, 7, 10, 13, and 16 mm have less viability than control cells. Conclusion: Photodynamic therapy 405 nm with 4 mm irradiation distance gives a biostimulation response so that the viability of BHK-21 fibroblast cells increases.

THE CELL FOR ELECTRON IRRADIATION OF STRESSED STEEL SAMPLES IN A SUPERCRITICAL WATER FLOW FOR CORROSION EVALUATION

To study experimentally the stress enhanced corrosion of structural materials in a water coolant flow under electron irradiation, a novel design of the target irradiation cell was developed. The stress application scheme is described and the stress-strain state of samples is calculated. Hydraulic resistance of the stainless steel 12X18H10T samples loaded cell has been measured at a dedicated facility and is discussed in terms of hydraulic and hydrodynamic models. System Thermal Hydraulics calculations have shown the device capability to operate efficiently in a natural convection driven Supercritical Water Circulation Loop.

Phototoxicity Evaluation of Hair Cleansing Conditioners

Photoactivation of cosmetic products and/or their ingredients may be associated with adverse skin reactions. Concerns have been raised regarding potential adverse health effects associated with the use of WEN by Chaz Dean (WCD) hair-cleansing conditioners, including alleged symptoms of redness, burning sensation, and irritation. The objective of this study was to use a validated phototoxicity test to evaluate the phototoxic potential of WCD hair-cleansing conditioners, and to demonstrate this assay’s applicability to personal care and cosmetic products. Balb/c 3T3 mouse fibroblast cells were exposed to the test articles for one hour. Following the incubation, one set of treated 3T3 cells were irradiated with 5 J/cm2 Solar Simulated Light (SSL), while a duplicate set of treated 3T3 cells were kept in the dark. After UV irradiation, cell viability was determined by neutral red uptake. The difference in cell viability between the SSL exposed and non-exposed 3T3 cells were used to determine the phototoxic potential of the test articles. Under the conditions tested, WCD hair-cleansing conditioners were not phototoxic, while the positive control was significantly phototoxic. Taken together, these results demonstrate that that the use of WCD hair-cleansing conditioners would not be expected to cause phototoxicity in consumers.