Natural Light Exposure Research Articles

Fabrication of chitosan-protocatechuic acid conjugates to inhibit lipid oxidation and improve the stability of β-carotene in Pickering emulsions: Effect of molecular weight of chitosan

In this study, chitosan (CS) with different molecular weights was functionalized with protocatechuic acid (PA) by free-radical grafting reaction, and used for the inhibition of lipid oxidation and the enhancement of stability of β-carotene in Pickering emulsions. The order of grafting ratio of PA in CS-PA conjugates was CS400 (400 kDa CS) > CS200 (200 kDa CS) > CS100 (100 kDa CS). UV–vis, FT-IR and 1H NMR spectra proved that PA was covalently bonded to CS through amino and ester linkages. Compared with native CS, three CS-PA conjugates exhibited reduced crystallinity and thermal stability and improved antioxidant activity, with a molecular weight-dependent relationship. Besides, CS-PA-conjugate particles formed by ionic gelling procedure were spherically shaped and homogeneously dispersed, which substantially improved the stability of β-carotene in Pickering emulsions than CS particles under ultraviolet irradiation, natural light exposure and heat treatment, and the retention rates of β-carotene were in the following order: CS200-PA- > CS400-PA- > CS100-PA-conjugate particles. Furthermore, the oxidation stability of Pickering emulsions fabricated by CS-PA-conjugate particles was also higher than that of CS particles. These results will provide valuable information for the application of CS-PA conjugates to protect bioactive components and inhibit lipid oxidation in emulsion systems.

Plasma Vitamin D (25-Hydroxyvitamin D) Levels in Hispaniolan Amazon Parrots (Amazona ventralis) Housed Indoors Over Time.

Vitamin D is a hormone that can be ingested or synthesized in the body when skin is exposed to ultraviolet radiation (UV), typically from sunlight. In captivity, birds with no sunlight exposure may develop vitamin D deficiencies that may contribute to hypocalcemic conditions, even when fed a diet supplemented with vitamin D. An initial pilot study with Hispaniolan Amazon parrots (Amazona ventralis) conducted approximately 18 mo prior indicated there were significant differences in the 25-hydroxyvitamin D (vit D) plasma levels between the resident parrots (indoor-only housing) and a new group of historically outdoor-housed parrots (new parrots) 5 days after the arrival of the latter at our institution. The goals of this study were to determine if vit D, ionized calcium (Ca2+), and ionized magnesium (Mg2+) levels changed from baseline values (taken 18 mo prior) in the new birds as well as to compare those values to those of the resident birds over time. The treatment was a change in husbandry for the new parrots (no UV exposure and diet as provided for the resident parrots). To accomplish this, the authors compared vit D levels in the same two groups of birds that were fed the same vit D-fortified diet and given no access to natural or artificial UV light exposure for 18 mo. The resident parrots (N = 9) had been housed indoors for approximately 20 yr with no exposure to natural or supplemented UV light. The second group of birds (new parrots; N = 8) had been housed outdoors prior to the initiation of the pilot study in 2016 and were fed a similar-but not identical-diet prior to their arrival. Plasma samples were sent to the Michigan State University Diagnostic Center for Population and Animal Health for analysis. Test results demonstrated differences between the two groups of parrots, largely attributed to the decrease in vit D plasma levels in the new parrots over time to values equivalent to those measured in the resident birds. Differences were seen in plasma Ca2+, while no differences were demonstrated relative to Mg2+. We discuss these findings and suggest that plasma vit D levels decrease in the absence of UV light, even when animals are maintained on a vit D-fortified and balanced diet.

Light, sleep-wake rhythm, and behavioural and psychological symptoms of dementia in care home patients: Revisiting the sundowning syndrome.

ObjectivesIt is believed that inadequate environmental light, especially in facilities such as care homes, contribute to the diurnal changes of behavioural and psychological symptoms of dementia (BPSD) historically referred to as “sundowning syndrome”. Conceptual models of sundowning phenomena have shifted emphasis from the role of light in vision (image forming) to its role in circadian rhythm modulation. However, the grounds for this change are unclear and the evidence on which it is based has not been examined comprehensively.MethodsWe have searched literature on sundowning syndrome and its association with light and studies evaluating BPSD, behavioural rhythm and environmental light in care homes in four databases (PubMed, Web of Science, Embase and Cochrane Library) from inception to 31 January 2021.ResultsOf the nine studies investigating light, behavioural rhythm and BPSD in care homes identified, we found evidence that insufficient natural light exposure was associated with worsening of BPSD and disrupted activity rhythm but it was not clear whether this related to image forming or disrupted circadian rhythm. There was a paucity of evidence in relation to the role of low levels of light for image forming in the context of a specific BPSD symptom: visual hallucinations. We also found literature on the possible role of light outside the visible spectrum influencing cognition. Based on the evidence, we proposed a new model integrating different components of light in BPSD and sundowning syndrome that combines its image forming and circadian roles.ConclusionsInadequate light may be a risk factor for BPSD and sundowning syndrome for dementia patients through a range of different mechanisms. It is recommended that multiple neuro‐endocrinological and socio‐environmental factors relevant to light such as adjusting the environmental setting, increasing light exposure, and scheduling activities should be considered when treating dementia patients with BPSD.

Risk factors, time to onset and recurrence of delirium in a mixed medical-surgical ICU population: A secondary analysis using Cox and CHAID decision tree modeling.

A retrospective secondary analysis of 4,200 patients was collected from two academic medical centers. Delirium was assessed using the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) in all patients. Univariate and multivariate Cox models, logistic regression analysis, and Chi-square Automatic Interaction Detector (CHAID) decision tree modeling were used to explore delirium risk factors. Increased delirium risk was associated with exposed only to artificial light (AL) hazard ratio (HR) 1.84 (95 % CI: 1.66-2.044, P<0.001), physical restraint application 1.11 (95 % CI: 1.001-1.226, P=0.049), and high nursing care requirements (>8 hours per 8-hour shift) 1.18 (95 % CI: 1.048-1.338, P=0.007). Delirium incidence was inversely associated with greater family engagement 0.092 (95 % CI: 0.014-0.596, P=0.012), low staff burnout and anticipated turnover scores 0.093 (95 % CI: 0.014-0.600, P=0.013), non-ICU length-of-stay (LOS)<15 days 0.725 (95 % CI: 0.655-0.804, P<0.001), and ICU LOS ≤15 days 0.509 (95 % CI: 0.456-0.567, P<0.001). CHAID modeling indicated that AL exposure and age <65 years were associated with a high risk of delirium incidence, whereas SOFA score ≤11, APACHE IV score >15 and natural light (NL) exposure were associated with moderate risk, and female sex was associated with low risk. More rapid time to delirium onset correlated with baseline sleep disturbance (P=0.049), high nursing care requirements (P=0.019), and prolonged ICU and non-ICU hospital LOS (P<0.001). Delirium recurrence correlated with age >65 years (HR 2.198; 95 % CI: 1.101-4.388, P=0.026) and high nursing care requirements (HR 1.978, 95 % CI: 1.096-3.569), with CHAID modeling identifying AL exposure (P<0.001) and age >65 years (P=0.032) as predictive variables. Development of ICU delirium correlated with application of physical restraints, high nursing care requirements, prolonged ICU and non-ICU LOS, exposure exclusively to AL (rather than natural), less family engagement, and greater staff burnout and anticipated turnover scores. ICU delirium occurred more rapidly in patients with baseline sleep disturbance, and recurrence correlated with the presence of delirium on ICU admission, exclusive AL exposure, and high nursing care requirements.

Association of natural light exposure and delirium according to the presence or absence of windows in the intensive care unit.

BackgroundPatients in the intensive care unit (ICU) have increased risks of delirium, which is associated with worse outcomes. As pharmacologic treatments for delirium are ineffective, prevention is important. Nonpharmacologic preventive strategies include exposure to natural light and restoring circadian rhythm. We investigated the effect of exposure to natural light through windows on delirium in the ICU.MethodsThis retrospective cohort study assessed all patients admitted to the medical ICU of a university-affiliated hospital between January and June 2020 for eligibility. The ICU included 12 isolation rooms, six with and six without windows. Patients with ICU stays of >48 hours were included and were divided into groups based on their admission to a single room with (window group) or without windows (windowless group). The primary outcome was the cumulative incidence of delirium. The secondary outcomes were the numbers of delirium- and mechanical ventilation-free days, ICU and hospital length of stay, and in-ICU and 28-day mortalities.ResultsOf the 150 included patients (window group: 83 [55.3%]; windowless group: 67 [44.7%]), the cumulative incidence of delirium was significantly lower in the window group than in the windowless group (21.7% vs. 43.3%; relative risk, 1.996; 95% confidence interval [CI], 1.220–3.265). Other secondary outcomes did not differ between groups. Admission to a room with a window was independently associated with a decreased risk of delirium (adjusted odds ratio, 0.318; 95% CI, 0.125–0.805).ConclusionsExposure to natural light through windows was associated with a lower incidence of delirium in the ICU.

Long-term cumulative light exposure from the natural environment and sleep: A cohort study.

We analysed (A) the association of short-term as well as long-term cumulative exposure to natural light, and (B) the association of detailed temporal patterns of natural light exposure history with three indicators of sleep: sleep duration, sleep problems, and diurnal preference. Data (N=1,962; 55% women; mean age 41.4years) were from the prospective Young Finns Study, which we linked to daily meteorological data on each participant's neighbourhood natural light exposure using residential postal codes. Sleep outcomes were self-reported in 2011. We first examined associations of the sleep outcomes with cumulative light exposure of 5-year, 2-year, 1-year, and 2-month periods prior to the sleep assessment using linear and Poisson regression models adjusting for potential confounders. We then used a data-driven time series approach to detect clusters of participants with different light exposure histories and assessed the associations of these clusters with the sleep outcomes using linear and Poisson regression analyses. A greater cumulative light exposure over ≥1year was associated with a shorter sleep duration (β=-0.10, 95% confidence interval [CI] -0.15 to -0.04), more sleep problems (incident rate ratio [IRR] 1.04, 95% CI 1.0-1.07) and diurnal preference towards eveningness (β=-0.09, 95% CI -0.14 to -0.03). The data-driven exposure pattern of "slowly increasing" light exposure was associated with fewer overall sleep problems (IRR 0.93, 95% CI 0.88-0.98) compared to a "recently declining" light exposure group representing the "average-exposure" group. These findings suggest that living in an area with relatively more intense light exposure for a longer period of time influences sleep.

Area light source-triggered latent angiogenic molecular mechanisms intensify therapeutic efficacy of adult stem cells.

Light‐based therapy such as photobiomodulation (PBM) reportedly produces beneficial physiological effects in cells and tissues. However, most reports have focused on the immediate and instant effects of light. Considering the physiological effects of natural light exposure in living organisms, the latent reaction period after irradiation should be deliberated. In contrast to previous reports, we examined the latent reaction period after light exposure with optimized irradiating parameters and validated novel therapeutic molecular mechanisms for the first time. we demonstrated an organic light‐emitting diode (OLED)‐based PBM (OPBM) strategy that enhances the angiogenic efficacy of human adipose‐derived stem cells (hADSCs) via direct irradiation with red OLEDs of optimized wavelength, voltage, current, luminance, and duration, and investigated the underlying molecular mechanisms. Our results revealed that the angiogenic paracrine effect, viability, and adhesion of hADSCs were significantly intensified by our OPBM strategy. Following OPBM treatment, significant changes were observed in HIF‐1α expression, intracellular reactive oxygen species levels, activation of the receptor tyrosine kinase, and glycolytic pathways in hADSCs. In addition, transplantation of OLED‐irradiated hADSCs resulted in significantly enhanced limb salvage ratio in a mouse model of hindlimb ischemia. Our OPBM might serve as a new paradigm for stem cell culture systems to develop cell‐based therapies in the future.

Relationships of Light to Enzyme and Sucrose Transformations in Sugarcane Treated with Paraquat

Relationships of Light to Enzyme and Sucrose Transformations in Sugarcane Treated with Paraquat

Sleep and circadian rhythm characteristics in individuals from the general population during the French COVID-19 full lockdown.

SummaryThe full 2‐month lockdown to fight the coronavirus disease 2019 (COVID‐19) pandemic in 2020 led to substantial disruption of daily life and routines. The present study aimed to comprehensively identify the lockdown’s effects on sleep, daily rhythms and emotions of the French population. A survey was published online during the last week of the 2‐month full lockdown and 1,627 individuals completed the online survey. The survey was self‐administered and included standardised questionnaires. Sleep schedules were delayed during lockdown in more than half of the participants. New severe delayed sleep phase affected 10% of participants with sleep schedules delayed by ≥3 hr during the lockdown compared to before. A significant decrease in exposure to morning (p < 0.001) and evening natural light (p < 0.001), a significant increase in screen exposure time (with a significant screen exposure >3 hr during the evening for 45% of the participants during lockdown versus 18% before lockdown, p < 0.001), an increase in substance use for one‐quarter of participants, a poorer sleep quality in 56% of participants, and less regular sleep schedules in 48% of participants were observed. We also found a poorer sleep quality in women than men during lockdown (p = 0.004). The French full lockdown had a severe impact on sleep quality, sleep–wake rhythms, and sleep behaviours. The implementation of public health strategies for the prevention and care of sleep–wake cycles during lockdown are therefore essential.

A combined use of image and range-based data acquisition for the three-dimensional information mapping archaeological heritage

Acquisition of accurate archaeological heritage data is fundamental for the prospective steps of architectural conservation process. As of today, digital data capturing technologies such as image-based and range-based systems are rapidly becoming prevalent and generating digital surface representations of the object(s) in the form of three-dimensional point clouds. Point clouds assist heritage experts to carry out heritage analysis in digital forms, in particular to conduct condition assessment based on orthophotos of archaeological assets. In this paper, we introduce an integrated strategy by using Terrestrial Laser Scanning (TLS) and photogrammetry for the scope of obtaining orthophotos as basis for analyzing geometric, texture and color information of archaeological remains. Such a combination allows overcoming insufficiencies especially in terms of color due to the high natural light exposure. To remedy such visual obstacles, this paper demonstrates results to generate maximum visual data coverage of an archaeological heritage asset for the conservation process.

Effects of brightness levels on stress recovery when viewing a virtual reality forest with simulated natural light

Although previous studies have shown that both forest and natural light exposure can significantly affect psycho-physiological responses, how different natural light levels influence stress recovery efficacy in forest environments has not been discussed yet. A pretest-posttest design was used to explore the influence of varying brightness levels on stress recovery effect in a virtual forest environment. Six immersive virtual environments (IVE) stimuli were generated from the lightest to the darkest through virtual reality simulation software. A total of 120 participants viewed the IVE using head-mounted display. Physiological and psychological responses and perceived environmental features were evaluated. The results of the present study confirmed previous findings that bright sunlight scenes (i.e., the lightest, lighter, light) allay stress more effectively than the darkest night scenes in the virtual forest. Another noteworthy finding is that dark scenes, such as daybreak without sunlight but with a little brightness, also has this property. An unexpected finding was that exposure to the natural light of medium-brightness (i.e., lighter, light, dark) in the virtual forest could significantly reduce the stress of the participants, compared to overly bright (i.e., the lightest level) or overly dark (i.e., the darkest level) levels. In addition, this study also found that perceived environmental features (i.e., maintenance, visibility, accessibility, variety, and perceived safety) and stress recovery were associated with different levels of brightness in the simulated forest environment. The results of this study contribute to existing forest therapy theory and offer insights for follow-up research to explore forest therapy and bright light therapy.

The impact of SARS-CoV-2 on sleep

Free AccessLetters to the EditorThe impact of SARS-CoV-2 on sleep Sogol Javaheri, MD, MPH, Shahrokh Javaheri, MD Sogol Javaheri, MD, MPH Division of Sleep Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts Search for more papers by this author , Shahrokh Javaheri, MD Division of Pulmonary and Sleep Medicine, Bethesda North Hospital, Cincinnati, Ohio Search for more papers by this author Published Online:August 15, 2020https://doi.org/10.5664/jcsm.8598Cited by:1SectionsAbstractPDF ShareShare onFacebookTwitterLinkedInRedditEmail ToolsAdd to favoritesDownload CitationsTrack Citations AboutABSTRACTCitation:Javaheri S, Javaheri S. The impact of SARS-CoV-2 on sleep. J Clin Sleep Med. 2020;16(8):1413.INTRODUCTIONThe COVID-19 pandemic not only has devastating impacts on health care and the economy, it has adversely affected the most basic aspects of life, including sleep. Over the last 2 months, we have observed concerning trends in the sleep health of our patients and suspect these trends are universal in parts of the country with similar sheltering mandates.Significant stressors including school closures, economic insecurity, fear of death, and the psychological and physical effects of social distancing have important implications, including sleep disturbances. Difficulty falling and staying asleep has increased among our patients with and without prior history of insomnia for a variety of reasons including increased anxiety levels, caffeine use, alcohol consumption, and blue light exposure secondary to increased screen time.In addition to insomnia, sheltering at home appears to have resulted in alterations in sleep circadian pattern, predominantly with sleep phase delays. Many patients are delaying sleep time from 10 pm to midnight and rise time from 6–7 to 8–9 am, a disorder called delayed sleep phase syndrome. Additionally, frequency of daytime napping has increased. Once daily obligations resume, the expected impacts include difficulty falling asleep and waking up earlier, increased fatigue, and excessive daytime sleepiness.Alcohol consumption has increased considerably based on patient reporting and spikes in alcohol sales, particularly online. Many restaurants are also offering sale of alcohol with carryout food for the first time, and bars are offering virtual happy hours.1 Alcohol inhibits the immune response and has a proinflammatory effect,2 which may increase susceptibility to COVID-19 infection and disease severity. Furthermore, alcohol worsens obstructive sleep apnea by relaxing upper airway musculature, causes sleep maintenance insomnia during the latter half of the night, and reduces rapid eye movement sleep3 with deleterious consequences.Moreover, opioid use and overdoses have increased during sheltering. In Toronto, opioid overdose deaths, which had been declining, are at their highest since March 20194 (US statistics pending) and opioid-induced sleep apnea could be a contributing factor. Moreover, patient-reported use and demand for marijuana has also increased,5 and according to the National Institute of Drug Abuse, marijuana and opioid use may increase vulnerability with COVID-19 infection, particularly if inhaled.6Therefore, we recommend that our patients maintain consistent sleep/wake patterns, according to their usual work hours, minimize substance use including alcohol, and maintain physical activity and natural light exposure. For patients with obstructive sleep apnea, fixed continuous positive airway pressure may not be adequate to control obstruction, which is worsened by depressants like alcohol and opiates. Additionally, given the potential to aerosolize COVID-19 through the exhalation port of the device, we recommend patients with mild, uncomplicated obstructive sleep apnea living with others refrain from use, and those with moderate or severe disease sleep in a separate bedroom from bed partners while using continuous positive airway pressure.DISCLOSURE STATEMENTAll authors have seen and approved the manuscript. The authors report no conflicts of interest.REFERENCES1. Associated Press. US online alcohol sales jump 243% during coronavirus pandemic, Market Watch, 2 April. https://www.marketwatch.com/story/us-alcohol-sales-spike-during-coronavirus-outbreak-2020-04-01. Accessed May 2, 2020. Google Scholar2. Szabo G, Saha B. Alcohol’s effect on host defense. Alcohol Res. 2015;37(2):159–170. Google Scholar3. Ebrahim IO, Shapiro CM, Williams AJ, Fenwick PB. Alcohol and sleep I: effects on normal sleep. Alcohol Clin Exp Res. 2013;37(4):539–549. https://doi.org/10.1111/acer.12006 CrossrefGoogle Scholar4. Jeffords S. Coronavirus: Ontario opioid crisis worsens during pandemic as services for drug users scale back. The Canadian Press, 30 April. https://globalnews.ca/news/6890040/coronavirus-opioid-crisis-worsens-ontario/. Accessed May 2, 2020. Google Scholar5. Schaneman B. Wholesale cannabis flower prices in Massachusetts climb on mounting demand, sluggish supply. Marijuana Business Daily, 16 March. https://mjbizdaily.com/wholesale-cannabis-flower-prices-massachusetts-climb-on-mounting-demand/. Accessed May 2, 2020. Google Scholar6. Volkow N. COVID-19: Potential Implications for Individuals with Substance Use Disorders. National Institute on Drug Abuse, 11 June 2020. Retrieved from https://www.drugabuse.gov/about-nida/noras-blog/2020/04/covid-19-potential-implications-individuals-substance-use-disorders. Accessed May 5, 2020. Google Scholar Previous article Next article FiguresReferencesRelatedDetailsCited by The COVID-19 pandemic, an environmental neurology perspectiveReis J, Buguet A, Román G and Spencer P Revue Neurologique, 10.1016/j.neurol.2022.02.455, Vol. 178, No. 6, (499-511), Online publication date: 1-Jun-2022. Volume 16 • Issue 8 • August 15, 2020ISSN (print): 1550-9389ISSN (online): 1550-9397Frequency: Monthly Metrics History Submitted for publicationMay 7, 2020Submitted in final revised formMay 18, 2020Accepted for publicationMay 19, 2020Published onlineAugust 15, 2020 Information© 2020 American Academy of Sleep MedicinePDF download

Study of the residential structure’s development planning influence on the insolation regime and natural illumination of the territory

The problem of residential buildings’ insolation is one of the fundamental in the housing planning projects’ development. Currently, two normalized parameters are estimated in Russia: the insolation itself and the coefficient of natural light exposure. These two parameters together govern the planning decisions’ adoption, including from the standpoint of the premises and territories’ natural disinfection. At the same time, these two parameters make it possible to regulate the spot development and prevent the cases of standards violation. There are several generally accepted types of buildings characteristic of modern cities: group, perimeter, lowercase, free. Each type of building is characterized by its own layout of buildings. Accordingly, each scheme determines the insolation mode and natural illumination of buildings and territories. Mathematical analysis and full-scale experiment will allow to evaluate the advantages and disadvantages of the considered types of residential areas’ development. In addition to the planning structure, insolation and natural illumination of territories are affected by the number of storeys in the building. The higher is the number of storeys, the less are the considered indicators. Accordingly, when considering the issues of insolation and natural light, along with the planning structure of residential buildings, attention should be paid to the number of storeys in the building. The theoretical and field studies presented in this work will allow in practice, when developing the new planning solutions, as well as reconstructing the existing buildings, to adopt the type of residential planning that most fully meets the regulatory requirements for insolation and natural light.

Improvement of the storage stability of C-phycocyanin in beverages by high-pressure processing

This study investigates the effect of high-pressure processing (HPP) on the structure and color stability of phycocyanin, phycocyanin-whey protein, and phycocyanin-carrageenan mixtures. All samples at pH 3.0 are very stable during HPP treatment, as evidenced by the minimal color loss and minor structural changes of phycocyanin. However, at pH 5.0 and 7.0, the materials are not stable under the same HPP treatment, losing 10–30% of the blue color intensity. Circular dichroism and intrinsic fluorescence confirmed the samples at pH 5.0 lose more secondary structure than those at pH 3.0 and pH 7.0 after HPP treatment. Electrophoresis revealed that phycocyanin-whey protein samples at pH 5.0 form large protein aggregates after HPP treatment. In addition, we also studied the stability of these HPP-treated samples under natural light exposure and found the light stability of the phycocyanin-whey protein mixture at pH 5.0 significantly improved after HPP treatment at both 450 MPa and 600 MPa. The light stability of phycocyanin-carrageenan at pH 7.0 was also improved after HPP treatment at 450 MPa. HPP treatment of the phycocyanin-whey protein and phycocyanin-carrageenan samples appears to encapsulate the blue chromophore inside the apoprotein network and decrease the attack of oxidizing radicals. This study illustrates the changes of phycocyanin under HPP treatment and yield insights to improve its storage stability under light exposure.

0782 Duration Of Sun Exposure In Medical Students Impactschronotype

Abstract Introduction Timing of the human sleep-wake cycle is determined by social constraints, biological processes (sleep homeostasis and circadian rhythmicity) and environmental factors, particularly natural and electrical light exposure. However the effect of environmental factors, especially duration of sun exposure, on circadian rhythmicity remains unknown. We aimed to study the relationship between duration of sun exposure and chronotype among medical students. Methods Eighty-six GW medical students (62 F [71%], 24 M [29%]; ages 21-33 y [mean 24.4 y]) completed the Munich Chronotype Questionnaire (MCTQ). Mid points, the middle of the participants reported bedtime and wake time on workdays, were used to determine chronotype. Two independent groups based on the mean split (mean = 45) of the distribution of minutes of sun exposure were created: 45 minutes or more (n=31) vs less than 45 minutes (n = 55) of sun exposure. Independent samples t-test was performed to compare the measured midpoint with the following pairs of groups of reported work day sunlight exposure (in minutes): less than 45 min (n = 55) versus 45 min or more (n = 31). Results In the total sample (n = 86), no significant association between duration of sun exposure and midpoints was found using Pearson correlation. However, medical students with reported sun exposure of greater than or equal to 45 minutes a day had a significantly earlier chronotype compared to students reporting a sun exposure of less than 45 minutes a day [mid point 2.196 (SD 0.085) versus a mid point 3.386 (SD 1.084); t(69) = 2.021; p = .047]. Conclusion We found that, in GW medical students, greater amounts of sun exposure during the day was advancing the circadian rhythm. This may have implications on sleep duration and quality. Support NA

M85. LIGHT-DARK AND ACTIVITY RHYTHM THERAPY TO IMPROVE SLEEP IN SCHIZOPHRENIA SPECTRUM DISORDERS: EXPERT CONSENSUS, INTERVENTION DEVELOPMENT AND FEASIBILITY TESTING

BackgroundSleep problems are prevalent in schizophrenia spectrum disorders, and include psychophysiological insomnia, and sleep disturbances caused predominantly by circadian dysregulation. Studies using motion sensing wearables (including actigraphy) have shown a diverse range of rest activity patterns, including mis-timed sleep, irregular sleep, or non-24hr (free-running) sleep patterns. Sleep and circadian rhythm disturbances impact negatively on functioning and quality of life, and long term poor sleep is linked to weight gain, and other serious physical health conditions. Many of the factors supposed to cause or maintain poor sleep in this group are modifiable through behavioural and environmental alterations.MethodsAn expert consensus study (Delphi study) was conducted to examine and explore the views of relevant experts, regarding the appropriate contents and format of an occupational therapy intervention to improve sleep in schizophrenia spectrum disorders. Experts were recruited with expertise in: occupational therapy, sleep, insomnia, circadian rhythm, and schizophrenia spectrum disorders. Experts with clinical and/or research expertise were sought, as well as service users and carers. We conducted three rounds of online surveys, individual interviews, and a day of content presentation, comments and voting, and discussion groups with service users and carers. Quantitative data were analysed using descriptive statistics and presented graphically for comparisons. Qualitative data (survey comments and interviews) was analysed using thematic analysis. Analysis and data collection was iterative; with later rounds exploring views raised during earlier rounds. The results informed the development of the intervention now being tested in a single group feasibility study recruiting twenty participants. Using mixed methods, this study will evaluate acceptability, homework adherence and trial related procedures, informing adjustments prior to larger scale testing.ResultsThe Delphi study recruited and retained participants well (n=82 of target=85, 66% uptake from professionals approached, 97% completion), suggesting a high level of interest in this topic. Participants reached consensus regarding relevant content within the initial assessment, increasing daytime natural light exposure (when possible), approaches to evening routine, and the approach to activity and occupation. Views varied regarding the relative importance of sleep restriction and building ‘sleep drive’, versus reducing arousal such as through relaxation, mindfulness, or cognitive approaches to anxiety. Often service users’ and carers’ views reflected those of professionals, however on some areas views between these groups differed, such as acceptable levels of intervention burden, and regarding wearables. Overall views highlighted the importance of a tailored intervention, with adjustable and selectable elements. The tailoring of recommendations will be achieved through a thorough assessment, including longitudinal use of light and movement sensing wearables, and a detailed initial interview. Many intervention components are optional based on needs, and the homework recommendations from ‘core’ intervention elements will vary depending upon individual needs, preferences, and baseline problems and situation.DiscussionThe diversity of sleep disturbance presentations within this group poses a unique challenge when developing a brief first-line intervention. Individually tailored recommendations can be derived through the combination of wearable technology and self-report, and a growing body of work informing models of sleep disturbance in this group.

Iron phthalocyanine-sensitized magnetic catalysts for BPA photodegradation

The catalytic behavior of iron phthalocyanine (FePc)-sensitized magnetic nanocatalysts was evaluated for their application in the oxidative treatment of Bisphenol A (BPA) under mild environmental conditions. Two types of FePc (Fe(II)Pc and Fe(III)Pc), which are highly photosensitive compounds, were immobilized on the surface of functionalized magnetite. The nanomaterials were characterized by high resolution transmission electron microscopy (HR-TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analyses (TGA). The generation of singlet oxygen by nanomaterials was also investigated. In the presence of UVA light exposure (365 nm) and 15 mM H2O2, the M@Fe(III)Pc photocatalyst gave the best results; for a catalyst concentration of 2.0 g L − 1, around 60% BPA was removed after 120 min of reaction. These experimental conditions were further tested under natural solar light exposure, for which also M@Fe(III)Pc exhibited enhanced oxidative catalytic activity, being able to remove 83% of BPA in solution. The water samples were less cytotoxic after treatment, this being confirmed by the MCF-7 cell viability assay.

Adsorptive and Photocatalytic Dye Removal from Wastewater Using Metal-Organic Frameworks

Trimesic acid in conjunction with microwave-assisted ball milling was used to produce Fe-based metal-organic frameworks (Fe-MOFs). Fe-MOFs were then used to eliminate organic dyes from aqueous solutions. Our results indicated Fe-MOFs eliminated nearly all Methylene Blue (MB) and Methyl Orange (MO). Within 120 min of Xe or natural light exposure, Fe-MOFs were able to remove 93.11% and 91.6%, respectively, of 10 mg/L MB in a 200 mL solution. Within 300 min of Xe or natural light exposure, Fe MOFs were able to remove 96.34% and 52.32%, respectively, of 5 mg/L MO from a 200 mL solution. Collectively, these results show that both dyes are suitable for use in the second kinetic model.

Furosemide in water matrix: HPLC-UV method development and degradation studies

This study developed a method for furosemide quantification through high performance liquid chromatographic technique. Special attention was given to solute loss and storage stability due to furosemide’s low solubility and photosensitivity, respectively. The performance of Nylon and PVDF filters was tested in a 2 mg.L-1 furosemide solution. PVDF filters showed better recovery capacity and therefore are more suitable for furosemide filtration. Over eight days, three different storage conditions were studied to access furosemide degradation susceptibility: (i) exposure to light at room temperature, (ii) storage at room temperature without exposure to light, and (iii) storage at 4ºC without exposure to light. The study demonstrated that after 48 h under natural light exposure furosemide was completely degraded. Furosemide solution stored in the dark was stable. Storage temperature did not seem to affect furosemide concentration. The study shows that the selection of more suitable filter and storage conditions for furosemide determination is crucial to avoid underestimation errors.

Impact of natural light exposure on delirium burden in adult patients receiving invasive mechanical ventilation in the ICU: a prospective study

ObjectiveTo determine whether potential exposure to natural light via windows is associated with reduced delirium burden in critically ill patients admitted to the ICU in a single room.DesignProspective single-center study.SettingMedical ICU of a university hospital, Paris, France.PatientsAdult patients receiving invasive mechanical ventilation.MethodsConsecutive patients admitted to a single room with (LIGHT group) or without (DARK group) exposure to natural light via windows were evaluated for delirium. The primary endpoint was the incidence of delirium. Main secondary endpoints included incidence of severe agitation intervened with antipsychotics and incidence of hallucinations.ResultsA total of 195 patients were included (LIGHT group: n = 110; DARK group: n = 85). The incidence of delirium was similar in the LIGHT group and the DARK group (64% vs. 71%; relative risk (RR) 0.89, 95% CI 0.73–1.09). Compared with the DARK group, patients from the LIGHT group were less likely to be intervened with antipsychotics for agitation episodes (13% vs. 25%; RR 0.52, 95% CI 0.27–0.98) and had less frequent hallucinations (11% vs. 22%; RR 0.49, 95% CI 0.24–0.98). In multivariate logistic regression analysis, natural light exposure was independently associated with a reduced risk of agitation episodes intervened with antipsychotics (adjusted odds ratio = 0.39; 95% CI 0.17–0.88).ConclusionAdmission to a single room with potential exposure to natural light via windows was not associated with reduced delirium burden, as compared to admission to a single room without windows. However, natural light exposure was associated with a reduced risk of agitation episodes and hallucinations.