Photochemistry and photobiology
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Photochem. Photobiol. · Sep 2020
ReviewSystematic Review of Photobiomodulation Therapy (PBMT) on the Experimental Calcaneal Tendon Injury in Rats.
This systematic review analyzed the light parameters and the effects of photobiomodulation therapy (PBMT) through low-level laser therapy (LLLT) and/or LED (light-emitting diode) on tendon repair of rats submitted to calcaneal injury. This study was conducted in accordance with the guidelines of the Preferred Reporting Items for Meta-Analysis, and PubMed and MEDLINE databases were accessed to search eligible studies published in English. The search terms were as follows: "Achilles tendon" or "Calcaneal tendon" or "tendon injuries" or "soft tissue injuries" and "tendinopathy" or "tendinitis" and "low-level light therapy" or "low-level laser therapy" or "low intensity power therapy" or "light-emitting diode" or photobiomodulation." The SYRCLE (SYstematic Review Center for Laboratory animal Experimentation) risks of bias was used to assess the risk of bias for selected studies. ⋯ Light parameters at red spectra, continuous versus pulsed mode, and PBMT combined or compared with other therapies such as ultrasound, and studies using unhealthy rats (ovariectomized and/or diabetic models) were also identified and grouped according to these similarities. The main effects found were decreased inflammatory markers and signs of inflammatory process. PBMT (laser/LED) has positive effects in reducing the inflammatory and time for tissue repair in animal models of tendon injury and/or tendinitis using parameters identified.
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Photochem. Photobiol. · Sep 2020
UVC Germicidal Units: Determination of Dose Received and Parameters to be Considered for N95 Respirator Decontamination and Reuse.
The COVID-19 pandemic has resulted in an international shortage of personal protective equipment including N95 filtering facepiece respirators (FFRs), resulting in many institutions using ultraviolet germicidal irradiation (UVGI) technology for N95 FFR decontamination. To ensure proper decontamination, it is crucial to determine the dose received by various parts of the FFR in this process. ⋯ The results demonstrate that all parts of the N95 FFR received at least 1 J cm-2 after one complete decontamination cycle with this unit. As there are a variety of UVGI devices and different types of FFRs, this study provides a model by which UVC dose received by different areas of the FFRs can be accurately assessed to ensure proper decontamination for the safety of healthcare providers.
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Photochem. Photobiol. · Jul 2020
Estimated Inactivation of Coronaviruses by Solar Radiation With Special Reference to COVID-19.
Using a model developed for estimating solar inactivation of viruses of biodefense concerns, we calculated the expected inactivation of SARS-CoV-2 virus, cause of COVID-19 pandemic, by artificial UVC and by solar ultraviolet radiation in several cities of the world during different times of the year. The UV sensitivity estimated here for SARS-CoV-2 is compared with those reported for other ssRNA viruses, including influenza A virus. The results indicate that SARS-CoV-2 aerosolized from infected patients and deposited on surfaces could remain infectious outdoors for considerable time during the winter in many temperate-zone cities, with continued risk for re-aerosolization and human infection. Conversely, the presented data indicate that SARS-CoV-2 should be inactivated relatively fast (faster than influenza A) during summer in many populous cities of the world, indicating that sunlight should have a role in the occurrence, spread rate and duration of coronavirus pandemics.
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Photochem. Photobiol. · Jul 2013
ReviewUltraviolet germicidal irradiation: future directions for air disinfection and building applications.
Ultraviolet germicidal irradiation (UVGI) for air disinfection applications has relied on low-pressure mercury vapor lamps for decades. New design requirements have generated the need for alternatives in some uses. This study describes the current state of UVGI technology and describes future directions for technology development, including the use of lamps produced from nontoxic materials and light-emitting diode lamps. Important applications are discussed such as the use of ultraviolet germicidal lamps in developing countries, in heating, ventilating and air-conditioning systems to improve energy efficiency and indoor air quality, and for whole room disinfection.
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Photochem. Photobiol. · Jul 2013
Upper-room ultraviolet germicidal irradiation (UVGI) for air disinfection: a symposium in print.
Upper-room ultraviolet germicidal irradiation (UVGI) has several applications, its most important use is to reduce tuberculosis transmission in high-burden, resource-limited settings, especially those dealing with epidemics of drug-resistant disease. The efficacy of upper-room (UVGI) to reduce the transmission of airborne infection in real-world settings is no longer in question. International application (dosing) guidelines are needed, as are safety standards and commissioning procedures. A recent symposium to build consensus on guidelines discussed specifications for affordable UVGI fixture designs, safety, performance, computer-aided design (CAD) for UVGI, maintenance, dosimetry, gonioradiometric measurement and innovation using germicidal LEDs.