Irradiation Devices Research Articles

Effectiveness of laser pulsed irradiation for antimicrobial photodynamic therapy

The aim of this study was to compare two types of light irradiation devices for antimicrobial photodynamic therapy (aPDT). A 660-nm light-emitting diode (LED) and a 665-nm laser diode (LD) were used for light irradiation, and 0.1 mg/L TONS 504, a cationic chlorin derivative, was used as the photosensitizer. We evaluated the light attenuation along the vertical and horizontal directions, temperature rise following light irradiation, and aPDT efficacy against Staphylococcus aureus under different conditions: TONS 504 only, light irradiation only, and TONS 504 with either LED (30 J/cm2) or LD light irradiation (continuous: 30 J/cm2; pulsed: 20 J/cm2 at 2/3 duty cycle, 10 J/cm2 at 1/3 duty cycle). Both LED and LD light intensities were inversely proportional to the square of the vertical distance from the irradiated area. Along the horizontal distance from the nadir of the light source, the LED light intensity attenuated according to the cosine quadrature law, while the LD light intensity did not attenuate within the measurable range. Following light irradiation, the temperature rise increased as the TONS 504 concentration increased in the order of pulsed LD < continuous LD < LED irradiation. aPDT with light irradiation only or TONS 504 only had no antimicrobial effect, while aPDT with TONS 504 under continuous or pulsed LD light irradiation provided approximately 3 log reduction at 30 J/cm2 and 20 J/cm2 and approximately 2 log reduction at 10 J/cm2. TONS 504-aPDT under pulsed LD light irradiation provided anti-microbial effect without significant temperature rise.

How Imaging Advances Are Defining the Future of Precision Radiation Therapy.

Radiation therapy is fundamental in the treatment of cancer. Imaging has always played a central role in radiation oncology. Integrating imaging technology into irradiation devices has increased the precision and accuracy of dose delivery and decreased the toxic effects of the treatment. Although CT has become the standard imaging modality in radiation therapy, the development of recently introduced next-generation imaging techniques has improved diagnostic and therapeutic decision making in radiation oncology. Functional and molecular imaging techniques, as well as other advanced imaging modalities such as SPECT, yield information about the anatomic and biologic characteristics of tumors for the radiation therapy workflow. In clinical practice, they can be useful for characterizing tumor phenotypes, delineating volumes, planning treatment, determining patients' prognoses, predicting toxic effects, assessing responses to therapy, and detecting tumor relapse. Next-generation imaging can enable personalization of radiation therapy based on a greater understanding of tumor biologic factors. It can be used to map tumor characteristics, such as metabolic pathways, vascularity, cellular proliferation, and hypoxia, that are known to define tumor phenotype. It can also be used to consider tumor heterogeneity by highlighting areas at risk for radiation resistance for focused biologic dose escalation, which can impact the radiation planning process and patient outcomes. The authors review the possible contributions of next-generation imaging to the treatment of patients undergoing radiation therapy. In addition, the possible roles of radio(geno)mics in radiation therapy, the limitations of these techniques, and hurdles in introducing them into clinical practice are discussed. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

Recovery Effect of Hot-Carrier Stress on γ-ray-Irradiated 0.13 μm Partially Depleted SOI n-MOSFETs

Many silicon-on-insulator (SOI) metal–oxide–semiconductor field-effect transistors (MOSFETs) are used in deep space detection systems because they have higher radiation resistance than bulk silicon devices. However, SOI devices have to face the double challenge of radiation and conventional reliability problems, such as hot carrier stress, at the same time. Thus, we wondered whether there is any interaction between reliability degradation and irradiation damage. In this paper, the effect of hot-carrier injection (HCI) on γ-ray-irradiated partially depleted (PD) SOI n-MOSFETs with a T-shaped gate structure is investigated. A strange phenomenon that accelerated the annealing effect on irradiation devices caused by HCI in 5 s was observed. That is, HCI has fast recovery ability on the irradiated narrow-channel n-MOSFETs. We explain the physical mechanism of this recovery effect qualitatively. Moreover, we designed a comparable experiment to evaluate the effect on the wide-channel devices. These results show that the narrow-channel devices are more sensitive to irradiation and HCI effects than wide-channel devices.

Promising Highly Targeted Therapies for Cholangiocarcinoma: A Review and Future Perspectives.

To overcome the poor prognosis of cholangiocarcinoma (CCA), highly targeted therapies, such as antibody-drug conjugates (ADCs), photodynamic therapy (PDT) with/without systemic chemotherapy, and experimental photoimmunotherapy (PIT), have been developed. Three preclinical trials have investigated the use of ADCs targeting specific antigens, namely HER2, MUC1, and glypican-1 (GPC1), for CCA. Trastuzumab emtansine demonstrated higher antiproliferative activity in CCA cells expressing higher levels of HER2. Similarly, "staphylococcal enterotoxin A-MUC1 antibody" and "anti-GPC1 antibody-monomethyl auristatin F" conjugates showed anticancer activity. PDT is effective in areas where appropriate photosensitizers and light coexist. Its mechanism involves photosensitizer excitation and subsequent reactive oxygen species production in cancer cells upon irradiation. Hematoporphyrin derivatives, temoporfin, phthalocyanine-4, talaporfin, and chlorine e6 derivatives have mainly been used clinically and preclinically in bile duct cancer. Currently, new forms of photosensitizers with nanotechnology and novel irradiation catheters are being developed. PIT is the most novel anti-cancer therapy developed in 2011 that selectively kills targeted cancer cells using a unique photosensitizer called "IR700" conjugated with an antibody specific for cancer cells. PIT is currently in the early stages of development for identifying appropriate CCA cell targets and irradiation devices. Future human and artificial intelligence collaboration has potential for overcoming challenges related to identifying universal CCA cell targets. This could pave the way for highly targeted therapies for CCA, such as ADC, PDT, and PIT.

Real-time monitoring of ultra-high dose rate electron beams using bremsstrahlung photons

Recently, as the clinically positive biological effects of ultra-high dose rate (UHDR) radiation beams have been revealed, interest in flash radiation therapy has increased. Generally, FLASH preclinical experiments are performed using UHDR electron beams generated by linear accelerators. Real-time monitoring of UHDR beams is required to deliver the correct dose to a sample. However, it is difficult to use typical transmission-type ionization chambers for primary beam monitoring because there is no suitable electrometer capable of reading high pulsed currents, and collection efficiency is drastically reduced in pulsed radiation beams with ultra-high doses. In this study, a monitoring method using bremsstrahlung photons generated by irradiation devices and a water phantom was proposed. Charges collected in an ionization chamber located at the back of a water phantom were analyzed using the bremsstrahlung tail on electron depth dose curves obtained using radiochromic films. The dose conversion factor for converting a monitored charge into a delivered dose was determined analytically for the Advanced Markus® chamber and compared with experimentally determined values. It is anticipated that the method proposed in this study can be useful for monitoring sample doses in UHDR electron beam irradiation.

Thermal annealing effects on the electrical characteristics of alpha particles irradiated MIS device AuTa2O5GaAs

An alpha particle-irradiated MIS device made of AuTa2O5GaAs was used to study how thermal annealing affects the I-V characteristics and how the current changes with annealing temperature, radiation energy, and voltage biassing. The super-gate of the MIS structure was made by using thermal evaporation to build a 1000°A thick layer of gold under a vacuum of about 10-5 torr. At room temperature, the devices were exposed to alpha particles from the radioactive source 226Ra (0.5 Ci) with energies of 5.1, 4, 3, 1.8, and 1.2 MeV for 0–30 minutes. After 30 minutes of annealing at 150, 200, and 300 o C in a vacuum of 10-3 torr, the current-voltage (I-V) characteristics of the irradiation devices were found. During thermal annealing, different results were seen with bias voltages of 0.4, 1, and 2 V and temperatures of 150, 200, and 300 o C. Annealing the device at 150 o C doesn't change how stable it is, but annealing it at 300 o C causes ohmic conduction in the device's properties. The device's current can be fixed best when the device is heated to 200 o C and then cooled. Also, thermal annealing seems to have different effects on the I–V electrical characteristics of the devices depending on the energy of the particles and the voltage biassing.

Ventilation Improvements Among K–12 Public School Districts — United States, August–December 2022

Improving ventilation has been one of several COVID-19 prevention strategies implemented by kindergarten through grade 12 (K-12) schools to stay open for safe in-person learning. Because transmission of SARS-CoV-2 occurs through inhalation of infectious viral particles, it is important to reduce the concentration of and exposure time to infectious aerosols (1-3). CDC examined reported ventilation improvement strategies among U.S. K-12 public school districts using telephone survey data collected during August-December 2022. Maintaining continuous airflow through school buildings during active hours was the most frequently reported strategy by school districts (50.7%); 33.9% of school districts reported replacement or upgrade of heating, ventilation, and air conditioning (HVAC) systems; 28.0% reported installation or use of in-room air cleaners with high-efficiency particulate air (HEPA) filters; and 8.2% reported installation of ultraviolet (UV) germicidal irradiation (UVGI) devices, which use UV light to kill airborne pathogens, including bacteria and viruses. School districts in National Center for Education Statistics (NCES) city locales, the West U.S. Census Bureau region, and those designated by U.S. Census Bureau Small Area Income Poverty Estimates (SAIPE) as high-poverty districts reported the highest percentages of HVAC system upgrades and HEPA-filtered in-room air cleaner use, although 28%-60% of all responses were unknown or missing. Federal funding remains available to school districts to support ventilation improvements. Public health departments can encourage K-12 school officials to use available funding to improve ventilation and help reduce transmission of respiratory diseases in K-12 settings.

Characterization of irradiation channels in the carousel of TRIGA Mark I IPR-R1 research reactor, Brazil, aiming at the application of k 0-standardization method of neutron activation analysis.

New values of neutron fluxes and spectral parameters f and α were determined experimentally in all irradiation devices of the TRIGA Mark I IPR-R1 nuclear research reactor at Nuclear Technology Development Centre (CDTN), Belo Horizonte, Brazil. Sets of monitors Au, Fe, Zn and Zr were irradiated bare and Cd-covered, according to "Cd-ratio for multi-monitor" method. Values were validated by analysing the certified reference material BCR-320R irradiated in chosen channels. The calculations were made based on irradiation channel values and the average values of the Carousel. The results of E n -score point out that the k 0-method is producing reliable results. From now on, the values of mass fractions in several matrices, the production and studies with radioisotopes will be more accurate and the activities calculated more precisely.

Fuel Irradiation Devices Test of Feedthroughs Equipped With Optical Fibers in support of the development of innovative instrumentation

Fuel Irradiation Devices Test of Feedthroughs Equipped With Optical Fibers in support of the development of innovative instrumentation

Lung stereotactic radiation therapy: Intercomparison of irradiation devices in terms of outcome and predictive factors

PurposeTo compare three different radiotherapy devices able to perform pulmonary stereotactic radiotherapy: CyberKnife® (CK), Helical Tomotherapy® (HT), and volumetric modulated arc therapy (VMAT). This study aims to define the patients’ outcome in terms of SBRT efficacy and toxicities depending of the device choice. Materials and methodsWe retrospectively analyzed the clinical, radiological, and dosimetric data of patients treated with lung SBRT between 2016 and 2020 at Lausanne University Hospital, using the Chi2 test for proportions, the t-test for means comparisons, the Kaplan-Meier method for survival, and the Log-rank test and Cox-regression for intergroups comparisons. ResultsWe identified 111 patients treated by either CK (59.9%), VMAT (38.0%), or HT (2.1%). Compared to other techniques, CK treated comparable gross tumor volume (GTV; 2.1 vs. 1.4cm3, P=0.84) with smaller planning treatment volume (PTV; 12.3 vs. 21.9cm3, P=0.013) and lower V5 (13.5 vs. 19.9cm3, P=0.002). Local control rates at 2years were not different whatever the irradiation device, respectively of 96.2% (range, 90.8–100) and 98.1% (range, 94.4–100), P=0.68. Toxicity incidence significantly increased with V5 value>17.2% (56.0 vs. 77.4%, P=0.021). ConclusionCompared to other SBRT techniques, CK treatments permitted to treat comparable GTV with reduced PTV and V5. Toxicity incidence was less frequent when reducing the V5. CK is particularly attractive in case of multiple courses of lung SBRT or lung reirradiation.

Conducting hematopoietic stem cell transplantation in low and middle income countries

ABSTRACT Background Hematopoietic stem cell transplantation (HSCT) is a well-recognized therapeutic procedure; costs limit its widespread use in low and middle income countries (LMIC). Methods Over a 30-year period, we have conducted HSCT in LMIC, making adaptations to the conventional procedures conducted in high-income countries (HIC). Results These salient observations stem from our practice: (1) Start with autologous transplantations in patients with hematological malignancies, specifically multiple myeloma; cell freezing devices are not necessary. (2) Next, consider auto-HSCT in patients with autoimmune diseases. (3) Introduce allogeneic transplants, initially using reduced intensity conditioning regimens. Conducting the HSCT on an outpatient basis is cheaper and safer. (4) Do not build HEPA-filtered rooms nor laminar flow cabins. (5) Do not graft cord blood cells nor start a cord blood blank. (6) Engage in haploidentical transplantations which are more feasible and cost-effective. (7) Matched unrelated donors are extremely expensive. (8) Use generic drugs and biosimilars. (9) Blood product irradiation devices are not necessary. (10) Do not try to reproduce other HSCT programs from HIC; develop your own methods. Conclusions HSCT can be conducted in LMIC with reduced costs and similar efficacy, thus making this therapeutic option affordable for more persons.

Temporal evolution characteristics and mechanism analysis of CCD breakdown induced by nanosecond and picosecond pulse lasers

Studies on the interaction between laser irradiation and charge-coupled devices (CCDs) have been reported to potentially bring new opportunities in the field of photoelectric countermeasures. It is known that the complete failure of CCD caused by pulsed laser originates from the destruction of CCD internal structure, but the detailed damage mechanism of laser-induced CCD breakdown is still a dilemma. Here, the thermal-mechanical coupling model of CCD irradiated by laser is established by finite element method, and the damage threshold and damage characteristics of CCD in point damage, line damage, black-and-white split screen and complete damage stages are characterized. The results show that the temperature rise effect of silicon substrate damage is predominant in the lateral direction, which increases by 300–3000 K; while it only increases by 300–400 K in the longitudinal direction. The complete damage threshold of CCD irradiated by nanosecond laser is 509 mJ/cm2; while that irradiated by picosecond laser is 190 mJ/cm2. When the silicon dioxide insulation layer is completely ablated, CCD completely fails due to the clock confusion caused by a short circuit between silicon electrodes.

The Concept of the Heat Removal System of a High-Flux Research Reactor

Achieving high neutron fluxes in research pressurized water reactors is directly related to the intensity of the coolant flow through the core and the pressure in it, which provides an increased saturation temperature and a margin to critical heat flux. Therefore, it is practically impossible to provide very high neutron fluxes in pool-type reactors, especially in the case of downward movement of the coolant in the core. At the same time, vessel-type research reactors (for example, SM-3 and HFIR) make it possible to achieve neutron flux densities up to 4 × 1015 n/(cm2 s), but at the same time, the risks of core degradation in case of violations in the heat removal system become quite high. The proposed concept of a heat removal system for a high-flux reactor facility combines the increased reliability of safe heat removal from the core and the convenience of handling irradiation cells, for example, in the production of isotopes. The concept provides for the location of a compact core in a pressurized vessel and the placement of a neutron reflector around the vessel in the reactor pool. Cooling of the reactor core in the housing and the irradiation channels in the neutron reflector is carried out by different systems of forced circulation of the coolant. At the same time, at the shutdown reactor, after opening the natural circulation valves, safe heat removal from the reactor core and the neutron reflector can be carried out by the water of the reactor pool. However, even with a complete failure of all forced circulation circuits, the evaporation of water from the surface of the pool makes it possible to safely remove the residual heat from the fuel assemblies and from the irradiation devices in the cells of the reflector.

Metrological Traceability and Crucial Detector Characteristics for UVC Metrology in UVGI Applications

Ultraviolet-C (UVC) radiation-based sanitization has globally gained enormous importance in the current COVID-19 (caused by SARS-COV-2 virus) pandemic situation. The effectiveness of radiation sanitization is quantified in terms of ‘radiation dose’, which in turn is derived from a radiometric parameter ‘irradiance’, measured using UVC radiometer. Metrological traceability of irradiance/dose measurement is essentially required for achieving requisite accuracy of measurements, and hence germicidal efficacy. In the present article, the derivation of traceability for irradiance measurement using UVC radiometer is demonstrated. The critical conditions to be considered while using detector/radiometer for measuring UVC irradiance/dose in practical conditions are elaborated, avoiding which, significant errors in the UVC irradiance/dose may arise, and hence, may compromise the performance of the Ultraviolet Germicidal Irradiation (UVGI) devices.

Reevaluation of Spectral Parameters and Neutron Fluxes in IC-7 Irradiation Channel of TRIGA MARK I IPR-R1 Research Nuclear Reactor

Abstract The core configuration of the Training Research Isotopes General Atomics (TRIGA) MARK I IPR-R1 nuclear research reactor at Nuclear Technology Development Centre (CDTN), Belo Horizonte, Brazil, has been modified six times since the first criticality and the neutron fluxes have been determined using experimental and semitheoretical methodologies determining the neutron fluxes in different irradiation channels and devices, applying different procedures and materials. This reactor operates at 100 kW; however, after new configuration for 250 kW in 2001, the carousel no longer rotates during irradiations aiming at preserving the rotation mechanism. In 2003, the spectral parameters were determined experimentally by the “Cd-ratio for multimonitor” in five specific channels aiming at the application of neutron activation analysis (NAA) k0-standardized method. The determinations were repeated applying the same procedure in 2016, 2018, and 2019. Values for thermal and epithermal neutron fluxes as well as f and α spectral parameters were determined. The experimental results for certified reference material BCR-320R were calculated by the k0-method of NAA, using the spectral parameters for irradiation channel IC-7 obtained in 2003, 2016, 2018, and 2019 and evaluated by En-score. The values showed that the differences in the results compared to those in 2003 were lower than 2.5%, inside the uncertainty of the method. It shows that the k0-method installed in CDTN is reliable and useful for various purposes. The results of the spectral parameter f presented small differences, in a period of 16 years, pointing out the stability of operation of the reactor TRIGA MARK I IPR-R1.

Efficacy of a 365 nm Ultraviolet A1 light Emitting Diode (UVA1-LED) in invitro Extracorporeal Photopheresis.

Extracorporeal photochemotherapy (ECP) is one of the more effective cell therapies for graft-versus-host disease (GvHD). ECP is a widely recommended therapeutic approach for the treatment of chronic GvHD, particularly steroid-refractory GVHD. In recent years, the use of a light emitting diode (LED) in the clinic has attracted considerable interest. In this study, we examined the issue of whether an ultraviolet A1-light emitting diode (UVA1-LED) can be used as a light source in ECP. To compare the efficacy of ECP with conventional UVA lamp and a UVA1-LED, we established an invitro ECP model. Treatment efficacy was evaluated by measuring the % apoptosis and the inhibition of T-cell proliferation. To investigate the effect of ECP on the innate immune reaction, THP-1 cells with a luciferase reporter gene driven by a NF-kB response element (THP-1 luc NF-kB) were treated with ECP. The LED-ECP induced apoptosis and inhibition of T-cell proliferation as efficiently as a conventional ECP. However, LED-ECP induced less innate immunity in THP-1. Since LED devices are more compact compared with conventional UVA irradiation devices, the use of a UVA1-LED in the treatment of ECP may be a better alternative to conventional ECP therapy.

A Review on Precision Polishing Technology of Single-Crystal SiC

Single-crystal SiC is a typical third-generation semiconductor power-device material because of its excellent electronic and thermal properties. An ultrasmooth surface with atomic surface roughness that is scratch free and subsurface damage (SSD) free is indispensable before its application. As the last process to reduce the surface roughness and remove surface defects, precision polishing of single-crystal SiC is essential. In this paper, precision polishing technologies for 4H-SiC and 6H-SiC, which are the most commonly used polytypes of single-crystal SiC, such as chemical mechanical polishing (CMP), photocatalytic chemical mechanical polishing (PCMP), plasma-assisted polishing (PAP), electrochemical mechanical polishing (ECMP), and catalyst-referred etching (CARE), were reviewed and compared with emphasis on the experimental setup, polishing mechanism, material removal rate (MRR), and surface roughness. An atomically smooth surface without SSD can be obtained by CMP, PCMP, PAP, and CARE for single-crystal SiC. However, their MRRs are meager, and the waste treatment after CMP is difficult and expensive. Moreover, PAP’s operation is poor due to the complex polishing system, plasma generation, and irradiation devices. A high MRR can be achieved by ECMP. In addition, it is an environmentally friendly precision polishing process for single-crystal SiC since the neutral salt solution is generally used as the electrolyte in ECMP. However, the formation of the egglike protrusions at the oxide/SiC interface during anodic oxidation would lead to a bigger surface roughness after ECMP than that after PAP is processed. The HF solution used in CARE was toxic, and Pt was particularly expensive. Ultrasonic vibration-assisted single-crystal SiC polishing and electrolyte plasma polishing (EPP) were discussed; furthermore, the research direction of further improving the surface quality and MRR of single-crystal SiC was prospected.

Inactivation of Escherichia coli, Salmonella enterica and Listeria monocytogenes on apple peel and apple juice by ultraviolet C light treatments with two irradiation devices

Following the market trends, the consumption of fresh and cold-pressed juice in Europe is increasing. However, a primary concern – particularly in apple juice – is the related outbreaks caused by food-borne pathogens. One of the challenges is to find methods able to reduce pathogenic loads while avoiding deterioration of nutritional properties and bioactive compounds that occur in thermal pasteurization processes. In this study, the inactivation of Escherichia coli, Salmonella enterica and Listeria monocytogenes was evaluated under different ultraviolet C (UVC254nm) light treatments (up to 10,665.9 ± 28.1 mJ/cm2), in two different steps of the production chain (before and after juice processing): on apple peel discs and in apple juice. The systems proposed were a horizontal chamber with UVC254nm emitting lamps treating the product disposed at a distance of 12 cm, and a tank containing UVC254nm lamps and in which the product is immersed and agitated. Final reductions ranged from 3.3 ± 0.5 to 5.3 ± 0.4 logarithmic units, depending on the microorganism, matrix and used device. The survival curves were adjusted to Weibull and biphasic models (R2-adj ≥ 0.852), and UVC doses needed for the first decimal reduction were calculated, being lower for the apple peel discs (0.20 to 83.83 mJ/cm2) than they were for apple juice (174.60 to 1273.31 mJ/cm2), probably for the low transmittance of the apple juice compared to the surface treatment occurring on the peels. Within the treatments evaluated, the UVC254nm irradiation of apple peels immersed in water was the best option as it resulted in a reduction of the tested microorganisms of ca. 2–3 log units at lower UVC254nm doses (< 500 mJ/cm2) when compared to those occurring in apple peel treated with the UVC chamber and in juice. As contamination can proceed from apples, the sanitization of these fruit prior to juice production may be helpful in reducing the safety risks of the final product, reducing the drawbacks related to the poor transmittance of the fruit juices.

Preclinical Model of Stereotactic Ablative Lung Irradiation Using Arc Delivery in the Mouse: Is Fractionation Worthwhile?

Lung stereotactic body radiation therapy is characterized by a reduction in target volumes and the use of severely hypofractionated schedules. Preclinical modeling became possible thanks to rodent-dedicated irradiation devices allowing accurate beam collimation and focal lung exposure. Given that a great majority of publications use single dose exposures, the question we asked in this study was as follows: in incremented preclinical models, is it worth using fractionated protocols or should we continue focusing solely on volume limitation? The left lungs of C57BL/6JRj mice were exposed to ionizing radiation using arc therapy and 3 × 3 mm beam collimation. Three-fraction schedules delivered over a period of 1 week were used with 20, 28, 40, and 50 Gy doses per fraction. Lung tissue opacification, global histological damage and the numbers of type II pneumocytes and club cells were assessed 6 months post-exposure, together with the gene expression of several lung cells and inflammation markers. Only the administration of 3 × 40 Gy or 3 × 50 Gy generated focal lung fibrosis after 6 months, with tissue opacification visible by cone beam computed tomography, tissue scarring and consolidation, decreased club cell numbers and a reactive increase in the number of type II pneumocytes. A fractionation schedule using an arc-therapy-delivered three fractions/1 week regimen with 3 × 3 mm beam requires 40 Gy per fraction for lung fibrosis to develop within 6 months, a reasonable time lapse given the mouse lifespan. A comparison with previously published laboratory data suggests that, in this focal lung irradiation configuration, administering a Biological Effective Dose ≥ 1000 Gy should be recommended to obtain lung fibrosis within 6 months. The need for such a high dose per fraction challenges the appropriateness of using preclinical highly focused fractionation schedules in mice.

26977 Synergistic blend of green tea and lotus protects against blue light-induced free radicals

Background: Growing evidence suggests that blue light emission stemming from solar irradiation and electronic devices, including computer screens, tablets and smartphones, has an effect on the molecular mechanism of premature photoaging. Exposure to blue light induces the generation of free radicals and reactive oxygen species (ROS) that cause inflammation and extrinsic skin aging. Quenching and scavenging free radicals can help mitigate and prevent signs of skin damage. We developed a patent-pending, nature-based blend of green tea and lotus that demonstrated a synergistic skin health benefit using DPPH assay.