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1.
Water Sci Technol ; 82(6): 1166-1175, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33055406

RESUMO

Escherichia coli (E. coli) first-order decay rates ranging from 3.34 to 11.9 d-1 (25-75% data range, N = 128) were recorded in two outdoor pilot-scale (0.88 m3) high rate algal ponds (HRAPs) continuously fed primary domestic wastewater over two years (influent E. coli cell count of 4.74·106 ± 3.37·106 MPN·100 mL-1, N = 142). The resulting removal performance was relatively constant throughout the year (log10-removal averaging 1.77 ± 0.54, N = 128), apart from a significant performance drop during a cold rainy period. E. coli removal performance was not strongly correlated to any of the meteorological or operational parameters recorded (e.g. sunlight intensity, pH, temperature). Hourly monitoring of E. coli cell count evidenced that E. coli removal, pH, dissolved oxygen (DO) and pond temperature peaked in the late afternoon of sunny summer days. Such improved daytime removal was, however, not evidenced in spring, even under sunny conditions causing milder increases in pH, DO and temperature. Overall, the data confirm the potential of HRAPs to support efficient E. coli removal during secondary domestic wastewater treatment and suggests E. coli decay was mainly caused by dark mechanisms episodically enhanced by indirect sunlight-mediated mechanisms and/or high pH toxicity.


Assuntos
Tanques , Águas Residuárias , Escherichia coli , Luz Solar , Eliminação de Resíduos Líquidos
2.
Adv Exp Med Biol ; 1268: 3-15, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32918211

RESUMO

How to deal with the powerful rays of the sun represents a fundamental question of environmental medicine, affecting skin cancer prevention campaigns and many other aspects of public health. However, when preparing recommendations for sunlight exposure, physicians, scientists, and other health authorities are in a dilemma, because solar radiation exerts both positive and negative effects on human health. While positive effects are at least in part mediated via the UV(Ultraviolet)-B-induced cutaneous synthesis of vitamin D, negative effects include the UV-mediated photocarcinogenesis of skin cancer. During the last century, interest in the positive effects of the sun on our health increased dramatically after the introduction of the so-called vitamin D/cancer hypothesis. In the late 1930s, Peller and Stephenson reported higher rates of skin cancer but lower rates of other cancers among the US Navy personnel. Several years later, Apperly reported an association between latitude and cancer mortality rate in North America. He argued that the "relative immunity to cancer is a direct effect of sunlight". Although the hypothesis that sun exposure may be beneficial against cancer had been proposed early, these observations supporting the hypothesis were ignored for nearly 40 years, until a clear mechanism was proposed. In the 1980s, Garland and Garland published a pilot study focusing on colon cancer and suggested that the possible benefits of sun exposure could be attributed to vitamin D. Later, the proposed protective role of vitamin D was extended to many other types of cancer. Subsequent laboratory investigations supported potential anti-carcinogenic effects of vitamin D compounds. We know today that many, but not all, of the positive effects of the sun on human health are mediated by the UV-induced cutaneous synthesis of vitamin D and other photoproducts. However, because of the abovementioned dilemma, there is an ongoing controversial discussion in scientific communities and in the general population that how much sunlight is optimal for human health. This chapter summarizes the content of the third edition of "Sunlight, Vitamin D and Skin Cancer," a book specifically designed and organized to be an up-to-date review covering the most important aspects of the ongoing debate on how much sun is good for human health and how to balance between the positive and negative effects of solar and artificial UV-radiation, including lessons learned from Paleolithic models and evolution .


Assuntos
Saúde , Luz Solar , Humanos , Medição de Risco , Luz Solar/efeitos adversos , Raios Ultravioleta/efeitos adversos , Vitamina D
3.
Adv Exp Med Biol ; 1268: 19-36, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32918212

RESUMO

Vitamin D is the sunshine vitamin for good reason. During exposure to sunlight, the ultraviolet B photons enter the skin and photolyze 7-dehydrocholesterol to previtamin D3 which in turn is isomerized by the body's temperature to vitamin D3. Most humans have depended on sun for their vitamin D requirement. Skin pigment, sunscreen use, aging, time of day, season, and latitude dramatically affect previtamin D3 synthesis. Vitamin D deficiency was thought to have been conquered, but it is now recognized that more than 50% of the world's population is at risk for vitamin D deficiency. This deficiency is in part due to the inadequate fortification of foods with vitamin D and the misconception that a healthy diet contains an adequate amount of vitamin D. Vitamin D deficiency causes growth retardation and rickets in children and will precipitate and exacerbate osteopenia, osteoporosis and increase risk of fracture in adults. The vitamin D deficiency pandemic has other serious consequences including increased risk of common cancers, autoimmune diseases, infectious diseases, and cardiovascular disease. There needs to be a renewed appreciation of the beneficial effect of moderate sensible sunlight for providing all humans with their vitamin D requirement for health.


Assuntos
Saúde , Neoplasias Cutâneas , Luz Solar , Raios Ultravioleta , Vitamina D , Humanos , Neoplasias Induzidas por Radiação/etiologia , Neoplasias Induzidas por Radiação/prevenção & controle , Medição de Risco , Neoplasias Cutâneas/etiologia , Neoplasias Cutâneas/prevenção & controle , Deficiência de Vitamina D/epidemiologia
4.
Adv Exp Med Biol ; 1268: 115-122, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32918215

RESUMO

Increasing sun exposure is related to lower prevalence of death in cardiovascular disease (CVD), type 2 diabetes, and other noncancer non-CVD. In this chapter we aim to make a short update on the knowledge regarding sun exposure and all-cause mortality. Data support the hypothesis that low sun exposure habits are a major risk factor for all-cause mortality. Low sun exposure is related to an increased risk of death due to CVD and noncancer/non-CVD, and a minor reduction in risk of cancer. Active sun exposure habits have a dual effect; it increases the incidence of skin cancer, but also improves the prognosis in terms of all-cause mortality. In a low solar intensity region, we should carefully assess both risk and benefits of sun exposure in order to obtain balanced recommendations.


Assuntos
Causas de Morte , Luz Solar , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/prevenção & controle , Diabetes Mellitus Tipo 2/epidemiologia , Diabetes Mellitus Tipo 2/prevenção & controle , Humanos , Fatores de Risco , Neoplasias Cutâneas/epidemiologia , Neoplasias Cutâneas/etiologia
5.
Adv Exp Med Biol ; 1268: 319-331, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32918226

RESUMO

Sunlight, in particular UV-B radiation, is an important factor for endogenous vitamin D production as 80-90% of the required vitamin D needs to be photosynthesized in the skin. The active form of vitamin D, vitamin D3 or calcitriol, binds to the ligand-activated transcription factor vitamin D receptor (VDR) for genomic and non-genomic effects. Recently, calcitriol and analogs have been shown to have antiproliferative effects in mouse and human BCC and SCC cell lines in vitro. As UV radiation plays a critical role in the photosynthesis of vitamin D, stringent sun protection, as recommended for xeroderma pigmentosum (XP) patients, may impact their vitamin D levels.XP is a rare autosomal recessive disorder with a worldwide prevalence of 1 in 1,000,000. XP can be divided into seven different complementation groups: XP-A to XP-G. The complementation groups correspond with the underlying gene defect. Defects in these genes lead to a defective nucleotide excision repair (NER), which is necessary to remove UV-induced DNA damage such as the UV photoproducts cyclobutane pyrimidine dimers (CPD) and 6-4 pyrimidine-pyrimidone (6-4 PP) dimer. Additionally, a variant form with a mutation in the translational polymerase η gene (PolH), also called XP variant (XPV), exists. Patients with XPV show a defect in translesion synthesis. Due to their inability to repair UV-induced lesions, XP patients exhibit an increased risk for UV-induced nonmelanoma skin cancer (NMSC) such as basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) as well as melanoma. Although no curative therapy for XP exists today, numerous options for the treatment and prophylaxis of skin cancer have become available.


Assuntos
Luz Solar , Vitamina D , Xeroderma Pigmentoso , Animais , Humanos , Raios Ultravioleta , Vitamina D/biossíntese , Vitaminas/biossíntese , Xeroderma Pigmentoso/genética , Xeroderma Pigmentoso/metabolismo
6.
Hautarzt ; 71(10): 772-785, 2020 Oct.
Artigo em Alemão | MEDLINE | ID: mdl-32915242

RESUMO

The sun is of great importance for human health. One important reason for this is the production of vitamin D, endorphins and many other hormones by the skin due to stimulation by sunlight. Insufficient access to sunlight increases the risk for vitamin D deficiency, a pandemic which would affect more than one billion people worldwide and under which ca. 60% of the population in Germany would suffer. The skin has a unique position in vitamin D metabolism as elementary steps for vitamin D production take place here and it is furthermore a target organ for actions of vitamin D. Due to the many positive effects of the sun, a healthy balance must be found between UV protection to shield against skin cancer but also ensuring sufficient vitamin D production. For regulation of this fragile balance between photoprotection and vitamin D production, which has accompanied mankind throughout evolution, sunscreens are an integral part of the modern lifestyle, although critical reports on possible risks for their use have recently become more frequent. This article discusses the current state of knowledge on the importance of vitamin D metabolism in human skin and the use of sun creams.


Assuntos
Neoplasias Cutâneas/prevenção & controle , Luz Solar/efeitos adversos , Raios Ultravioleta/efeitos adversos , Vitamina D/uso terapêutico , Alemanha , Humanos , Protetores Solares , Terapia Ultravioleta , Deficiência de Vitamina D
7.
PLoS One ; 15(9): e0237797, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32870919

RESUMO

In this study, the effect of glazing-to-total-wall-area ratio on the thermal performance of different wall materials is numerically investigated in terms of heat transmission load. The investigation was performed for a South-facing wall in Elazig, Turkey. The heat transmission load through walls and windows are determined separately for summer and winter climate conditions. In this analysis, the frame area of the window is not considered. Therefore, whereas the glazing area on uninsulated and insulated walls is increased from 0% to 100%, the heat gain and losses are calculated separately according to the glazing type. The transmission loads through the wall are determined by an implicit finite difference procedure under steady periodic conditions. Concrete, briquettes, bricks, and autoclaved aerated concrete are selected as structure materials. Results show that in the uninsulated wall, the wall material affected the glazing area, whereas in the insulated wall, the effect of wall material on glazing area is insignificant.


Assuntos
Materiais de Construção , Temperatura , Ar , Luz Solar , Turquia
8.
Clin Dermatol ; 38(4): 485-488, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32972607

RESUMO

Many factors affect the health and physiology of human skin, with some of them arising from outer space. This contribution explores four celestial influences on the skin: (1) the sun's ultraviolet light, which has both beneficial and deleterious dermatologic effects, (2) meteorite injuries, (3) possible lunar effects on the body's health, and (4) cosmic radiation as a risk factor for skin cancer and pregnancy-related complications. Some of these extraterrestrial influences on skin health have taken on added significance as human beings increasingly spend more time at higher altitudes in aircraft, spaceships, and space stations.


Assuntos
Radiação Cósmica/efeitos adversos , Neoplasias Cutâneas/etiologia , Pele/lesões , Pele/efeitos da radiação , Luz Solar/efeitos adversos , Raios Ultravioleta/efeitos adversos , Aeronaves , Altitude , Dermatite de Contato/etiologia , Feminino , Humanos , Masculino , Meteoroides , Lua , Gravidez , Complicações na Gravidez/etiologia
9.
Sci Total Environ ; 738: 140298, 2020 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-32806347

RESUMO

Imipramine (IMI) is a frequently prescribed tricyclic antidepressant and widely detected in the natural waters, while the environmental fate of IMI is yet poorly understood. Here, we investigated the photodegradation of IMI under simulated sunlight in the presence of humic substances (HS), typically including humic acid (HA) and fulvic acid (FA). The direct and indirect IMI photodegradation was found to increase both with increasing pH and with deoxygenation of the reaction solutions. The excited triplet state of HS (3HS⁎) was mainly responsible for the photosensitized degradation of IMI according to the steady-state quenching and direct time-resolved experiments. The electron transfer interaction between 3HS⁎ and IMI was observed by laser flash photolysis (LFP) with bimolecular reaction rate constants of (4.9 ± 0.4) × 109 M-1 s-1. Evidence of electron transfer from IMI to 3HS⁎ was further demonstrated by the photoproduct analysis. The indirect photodegradation was triggered off in the side chain of IMI with the nonbonding nitrogen electron transferring to 3HS⁎, followed by hydroxylation, demethylation and cleavage of the side chain. Very important that HS photosystem does not lose its efficiency with decreasing of IMI concentration, meaning that the studied photosystem still be used at environmentally relevant concentrations of IMI. These results suggest that photodegradation could be an important attenuation pathway for IMI in HS-rich and anaerobic natural waters.


Assuntos
Substâncias Húmicas/análise , Poluentes Químicos da Água , Imipramina , Fotólise , Luz Solar
10.
J Alzheimers Dis ; 77(1): 113-125, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32804145

RESUMO

BACKGROUND: A system of photosensitive retinal ganglion cells provides 'non-visual' information on the circadian sequences of light to the suprachiasmatic nucleus (SCN), which, as the 'master clock', synchronizes the chronobiological mechanisms of all the biological clocks. Damage to SCN structure alters circadian behavioral and hormonal rhythms and interferes with a regular sleep-wake pattern. Several studies have shown that, in aging and in Alzheimer's disease (AD), circadian rhythms change their synchronization with the environment and behavior loses sync with light. OBJECTIVE: The current overview aims to examine research studies showing the effect of bright light therapy (BLT) on sleep disorders and sleep-wake patterns in AD. METHODS: A literature search was conducted, taking into consideration the relevant studies over the last 20 years. Fifteen studies have been thorough: seven followed an environmental-architectural approach and eight followed a treatment devices approach. RESULTS: Studies agree in considering BLT as a promising non-pharmacological intervention to compensate for circadian rhythm alterations and they support the need for standardized protocols that allow a comparison between multicenter studies. CONCLUSION: Interestingly, in an attempt to contain the spread of the COVID-19 pandemic, health authorities have forced the population to stay home. Therefore, AD people are not currently able to enjoy exposure to sunlight. It is predictable that they may experience an exacerbation of circadian disturbances and that the BLT can be an effective response to prevent such exacerbation.


Assuntos
Doença de Alzheimer/terapia , Fototerapia/métodos , Transtornos do Sono-Vigília/terapia , Doença de Alzheimer/complicações , Doença de Alzheimer/fisiopatologia , Infecções por Coronavirus , Humanos , Pandemias , Pneumonia Viral , Transtornos do Sono-Vigília/etiologia , Transtornos do Sono-Vigília/fisiopatologia , Luz Solar , Núcleo Supraquiasmático
11.
PLoS One ; 15(8): e0237149, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32764774

RESUMO

PURPOSE: To investigate the association between daily sunlight exposure duration and diabetic retinopathy in Korean adults with diabetes. METHODS: This study used data from the 2008-2011 Korea National Health and Nutrition Examination Survey. Overall, 1,089 patients with diabetes aged >40 years were included. The duration of daily sunlight exposure was assessed via health interviews. Comprehensive ophthalmic evaluations, including standard retinal fundus photography after pupil dilation, were conducted. Diabetic retinopathy was graded using the modified Airlie House Classification. Multivariate logistic regression analysis was performed to analyze the association between daily sunlight exposure duration and the diagnosis of diabetic retinopathy and non-proliferative diabetic retinopathy. RESULTS: The risk of diabetic retinopathy was 2.66 times higher in the group with ≥5 h of daily sunlight exposure than in the group with less exposure after adjusting for risk factors such as duration of diabetes, serum hemoglobin A1c level, hypertension, and dyslipidemia (P = 0.023). Furthermore, the risk of non-proliferative diabetic retinopathy was 3.13 times higher in the group with ≥5 h of daily sunlight exposure than in the group with less exposure (P = 0.009). In patients with diabetes for <10 years, the risks of diabetic retinopathy and non-proliferative diabetic retinopathy were 4.26 and 4.82 times higher in the group with ≥5 h of daily sunlight exposure than the group with less exposure, respectively (P < 0.05). CONCLUSIONS: This study revealed that sunlight exposure for ≥5 h a day was significantly associated with an increased risk of diabetic retinopathy and non-proliferative diabetic retinopathy in Korean patients with diabetes. The risks were significantly higher in patients with diabetes for <10 years. Therefore, reducing daily sunlight exposure could be an early preventive strategy against diabetic retinopathy in people with diabetes.


Assuntos
Retinopatia Diabética/epidemiologia , Luz Solar/efeitos adversos , Idoso , Estudos Transversais , Retinopatia Diabética/diagnóstico , Retinopatia Diabética/etiologia , Retinopatia Diabética/prevenção & controle , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Inquéritos Nutricionais/estatística & dados numéricos , Estresse Oxidativo/efeitos da radiação , Fotografação , Fotoperíodo , Prevalência , República da Coreia/epidemiologia , Retina/diagnóstico por imagem , Retina/efeitos da radiação , Fatores de Risco , Índice de Gravidade de Doença , Fatores de Tempo
12.
Bull Environ Contam Toxicol ; 105(3): 433-439, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32740745

RESUMO

Direct photolysis of the emerging contaminant 2-(thiocyanomethylthio) benzothiazole (TMCTB) was performed in aqueous solution at different concentrations with high-pressure mercury lamp (5.0, 8.0, 13.0, 16.0, 20.0, 23.0, 27.0, 35.0, 40.0, 45.0, and 50.0 mg L- 1) and with natural sunlight radiation (6.0, 30.0, and 60.0 mg L- 1). TCMTB underwent rapid degradation by direct photolysis with a high-pressure mercury lamp in aqueous solutions, with 99% removal after 30 min at all concentrations studied. For sunlight photolysis, TCMTB degradation was observed with 96%, 81%, and 64% removal for initial concentrations of 6.0, 30.0, and 60.0 mg L- 1, respectively, after 7 h of exposure to sunlight. The degradation of TCMTB in lab-scale wastewater had kinetic constant and t1/2 in the same order when compared to the photodegradation of TCMTB in aqueous solutions. In addition, the results showed that photolysis with a high-pressure mercury lamp and sunlight were governed by the same kinetic order, however the kinetic parameters showed that degradation with sunlight was 40 times slower than photolysis with the mercury lamp. Twelve transformation products (TP) were identified, and eight of the TP have not been described in the literature. Furthermore, prediction of toxicity with ECOSAR software was carried out for fish, daphnids, and green algae species. It showed that photolytic treatment is efficient for reducing the toxicity of the compound, since the degradation formed compounds with lower toxicity than the primary compound. In conclusion, this study suggests that photolysis is an efficient way to remove the studied contaminant, and it highlights the potential of this technique for the degradation of emerging contaminants in industrial wastewater treatment plants.


Assuntos
Benzotiazóis/metabolismo , Poluentes Químicos da Água/metabolismo , Cinética , Fotólise , Luz Solar , Água , Poluentes Químicos da Água/análise
13.
Water Res ; 185: 116226, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32738603

RESUMO

Water contamination with the enteroprotozoan parasite Cryptosporidium is a current challenge worldwide. Solar water disinfection (SODIS) has been proved as a potential alternative for its inactivation, especially at household level in low-income environments. This work presents the first comprehensive kinetic model for the inactivation of Cryptosporidium parvum oocysts by sunlight that, based on the mechanism of the process, is able to describe not only the individual thermal and spectral actions but also their synergy. Model predictions are capable of estimating the required solar exposure to achieve the desired level of disinfection under variable solar spectral irradiance and environmental temperature conditions for different locations worldwide. The thermal contribution can be successfully described by a modified Arrhenius equation while photoinactivation is based on a series-event mechanistic model. The wavelength-dependent spectral effect is modeled by means of the estimation of the C. parvum extinction coefficients and the determination of the quantum yield of the inactivation process. Model predictions show a 3.7% error with respect to experimental results carried out under a wide range of temperature (30 to 45 °C) and UV irradiance (0 to 50 W·m-2). Furthermore, the model was validated in three scenarios in which the spectral distribution radiation was modified using different plastic materials common in SODIS devices, ensuring accurate forecasting of inactivation rates for real conditions.


Assuntos
Criptosporidiose , Cryptosporidium parvum , Cryptosporidium , Purificação da Água , Animais , Desinfecção , Luz Solar , Água
14.
Proc Biol Sci ; 287(1932): 20201326, 2020 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-32752991

RESUMO

Captive rearing of monarch butterflies is a commercial and personal pursuit enjoyed by many different groups and individuals. However, the practice remains controversial, especially after new evidence showed that both a group of commercially derived monarchs reared outdoors and a group of wild-derived but indoor-reared monarchs failed to orient south, unlike wild-derived monarchs reared outdoors. To more fully characterize the mechanisms responsible for the loss of orientation in both commercial and indoor-reared monarchs, we performed flight simulator experiments to determine (i) whether any fraction of commercial monarchs maintains a southern heading over multiple tests, and (ii) whether indoor conditions with the addition of sunlight can induce southern flight in wild-derived monarchs. Commercial monarchs changed their flight direction more often over the course of multiple tests than wild-derived monarchs. While as a group the commercial monarchs did not fly south on average, a subset of individuals did orient south over multiple tests, potentially explaining the discordance between flight simulator assays and the recovery of tagged commercial monarchs at overwintering locations. We also show that even when raised indoors with sunlight, wild-derived monarchs did not consistently orient south in the flight simulator, though wild-derived monarchs reared outdoors did orient south.


Assuntos
Migração Animal , Borboletas/fisiologia , Animais , Voo Animal , Orientação , Luz Solar
15.
Water Res ; 185: 116241, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32777596

RESUMO

The transmission of antibiotic resistance in surface water has attracted much attention due to its increasing threat to human health. The role of sunlight irradiation and the effect of dissolved organic matter (DOM) on the transmission of antibiotic resistance are still unclear. In this study, photo-inactivation of antibiotic resistant bacteria (ARB) was investigated using antibiotic resistant E. coli (AR E. coli) that contained the tetracycline resistance gene (Tc-ARG) as a representative. The results showed that AR E. coli underwent significant photo-inactivation due to the membrane damage induced by direct irradiation and by the generated reactive oxygen species. Simulated sunlight irradiation specifically suppressed the expression of tetracycline resistance, which is attributed to the destruction of tetracycline-specific efflux pump. Tetracycline inhibited the photo-inactivation of AR E. coli due to its selective pressure on tetracycline resistant E. coli and competitive light absorption effect. Suwannee River fulvic acid (SRFA), a representative DOM, promoted the inactivation of AR E. coli and further inhibited the expression of tetracycline resistance gene due to the generation of its excited triplet state, singlet oxygen, and hydroxyl radical. The extracellular Tc-ARG also underwent fast photodegradation under light irradiation and in the presence of SRFA, which leads to the decrease of its transformation efficiency. This study provided insight into the sunlight-induced inactivation of ARB, which is of significance for understanding the transmission of tetracycline resistance in surface water.


Assuntos
Luz Solar , Poluentes Químicos da Água , Antibacterianos/farmacologia , Bactérias , Escherichia coli/genética , Fotólise , Tetraciclina/farmacologia , Poluentes Químicos da Água/análise
16.
J Water Health ; 18(4): 494-504, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32833676

RESUMO

Solar disinfection (SODIS) has been shown to reduce the risk associated with the contraction of water borne diseases such as cholera. However, little or no research has been undertaken in exploring the role played by the immune system following the consumption of solar inactivated water pathogens. This study investigated the potential for solar inactivated Vibrio cholerae to induce the maturation of dendritic cells in vitro. Dendritic cells are professional antigen presenting cells found in mammals. However, only in their mature form are dendritic cells able to play their role towards a long lasting immune response. Three strains of V. cholerae were solar irradiated for 7 hours. Thereafter, the solar irradiated, non-solar irradiated, phosphate buffered saline prepared and heat/chemically inactivated cultures of V. cholerae as well as lipopolysaccharide and cholerae toxin-ß subunit were used to stimulate immature dendritic cells. After 48 hours, the dendritic cells were assessed for the expression of CD54, CD80, CD83, CD86, MHC-I and MHC-II cell surface markers. Results show that solar inactivated V. cholerae was able to induce maturation of the dendritic cells in vitro. These findings suggest that there may be an immunological benefit in consuming SODIS treated water.


Assuntos
Cólera , Células Dendríticas , Luz Solar , Vibrio cholerae , Animais , Anticorpos Antibacterianos , Linhagem Celular
17.
Sci Total Environ ; 746: 141332, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32758990

RESUMO

Psychoactive drug diazepam is one of benzodiazepines widely used in human medicine. It has been found to be relatively resistant to chlorination and photolysis. Here we investigated the transformation mechanism of diazepam in aqueous solution through UV/chlorine and simulated sunlight/chlorine treatments. The results showed that the UV/chlorine and sunlight/chlorine processes significantly increased the degradation of diazepam in water. These observed degradations can be elucidated by in-situ generation of reactive species including hydroxyl radical (HO), reactive chlorine species (RCS) and ozone (O3) during photolysis of chlorine. In the UV/chlorine treatment, the degradation efficiency of diazepam for HO, chlorine, UV and RCS reaction at 90 min was calculated to be 62.1%, 3.8%, 11.9% and 12.3%, respectively. In the simulated sunlight/chlorine treatment, the calculated degradation of 53.1%, 8.1% and 11.2% was attributed to HO, chlorine and RCS reaction, with negligible loss by O3 reaction and sunlight irradiation. In the UV/chlorine and sunlight/chlorine treatments, a total of 70 transformation products was detected using a high-resolution TripleTOF mass system. Six transformation pathways have been tentatively proposed for the diazepam, which includes hydroxylation, chlorination, hydrolyzation, N-demethylation, loss of phenyl group, benzodiazepine ring rearrangement and contraction. Most of the obtained transformation products were less toxic to aquatic organisms including fish, daphnia and green algae than diazepam itself according to the toxicity prediction tool, and did not cause significant changes in toxicity to luminescent bacteria.


Assuntos
Poluentes Químicos da Água/análise , Purificação da Água , Animais , Cloro , Diazepam , Cinética , Oxirredução , Fotólise , Luz Solar , Raios Ultravioleta , Água
18.
J Environ Sci (China) ; 95: 155-164, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32653175

RESUMO

The heterogeneous degradation of nitrogen dioxide (NO2) on five samples of natural Icelandic volcanic particles has been investigated. Laboratory experiments were carried out under simulated atmospheric conditions using a coated wall flow tube (CWFT). The CWFT reactor was coupled to a blue light nitrogen oxides analyzer (NOx analyzer), and a long path absorption photometer (LOPAP) to monitor in real time the concentrations of NO2, NO and HONO, respectively. Under dark and ambient relative humidity conditions, the steady state uptake coefficients of NO2 varied significantly between the volcanic samples probably due to differences in magma composition and morphological variation related with the density of surface OH groups. The irradiation of the surface with simulated sunlight enhanced the uptake coefficients by a factor of three indicating that photo-induced processes on the surface of the dust occur. Furthermore, the product yields of NO and HONO were determined under both dark and simulated sunlight conditions. The relative humidity was found to influence the distribution of gaseous products, promoting the formation of gaseous HONO. A detailed reaction mechanism is proposed that supports our experimental observations. Regarding the atmospheric implications, our results suggest that the NO2 degradation on volcanic particles and the corresponding formation of HONO is expected to be significant during volcanic dust storms or after a volcanic eruption.


Assuntos
Atmosfera , Ácido Nitroso , Poeira , Dióxido de Nitrogênio , Luz Solar
19.
J Environ Sci (China) ; 95: 165-171, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32653176

RESUMO

As an important indoor pollutant, nitrous acid (HONO) can contribute to the concentration of indoor OH radicals by photolysis via sunlight penetrating into indoor environments, thus affecting the indoor oxidizing capability. In order to investigate the concentration of indoor HONO and its impact factors, three different indoor environments and two different locations in urban and suburban areas were selected to monitor indoor and outdoor pollutants simultaneously, including HONO, NO, NO2, nitrogen oxides (NOx), O3, and particle mass concentration. In general, the concentration of indoor HONO was higher than that outdoors. In the urban area, indoor HONO with high average concentration (7.10 ppbV) was well-correlated with the temperature. In the suburban area, the concentration of indoor HONO was only about 1-2 ppbV, and had a good correlation with indoor relative humidity. It was mainly attributed to the heterogeneous reaction of NO2 on indoor surfaces. The sunlight penetrating into indoor environments from outside had a great influence on the concentration of indoor HONO, leading to a concentration of indoor HONO close to that outdoors.


Assuntos
Poluição do Ar em Ambientes Fechados/análise , Ácido Nitroso/análise , Óxidos de Nitrogênio , Fotólise , Luz Solar
20.
Environ Pollut ; 266(Pt 3): 115181, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32683092

RESUMO

The pressure on natural water resources associated with increasing water scarcity highlights the value of using reclaimed water through the development of efficient and environmentally friendly treatment technologies. In this work, the use of magnetic nanoparticles in photo-Fenton catalysis for water disinfection was considered to inactivate natural enteric bacteria present in municipal wastewater effluents under white light and neutral pH. The most recommended ranges were evaluated in key variables such as the loading and composition of nanoparticles (NPs), hydrogen peroxide (H2O2) concentration, the light source (UV and visible) and treatment time were evaluated in wastewater disinfection expressed in terms of total coliforms and Escherichia coli colony forming units (CFU). The magnetic separation of NPs allowed the disinfection process to be carried out in different cycles, facilitating the recovery of the nanocatalyst and avoiding its discharge with the treated effluent.


Assuntos
Microbioma Gastrointestinal , Purificação da Água , Catálise , Desinfecção , Compostos Férricos , Peróxido de Hidrogênio , Concentração de Íons de Hidrogênio , Ferro , Luz Solar , Águas Residuárias/análise
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