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1.
Guillermo De Castro‐Maqueda Jos V. Gutierrez‐Manzanedo Jorge R. Fernandez‐Santos Mario Linares‐Barrios Magdalena De Troya Martín 《Photochemistry and photobiology》2019,95(6):1468-1472
The high prevalence and increasing incidence of skin cancer (SC) is a significant public health problem. We can address its main risk factor, which is incident and accumulated solar radiation, and its damages by disseminating knowledge and promoting changes in habits and attitudes toward the sun. The influence of teachers in the education of young people is crucial. Physical education teachers (PET) spend the majority of their time outdoors, thereby exposing themselves to solar radiation daily and greatly increasing the risk of SC. We carried out a case–control study matching for age and gender through surveys about photoexposure and photoprotection habits on a sample of 200 teachers (100 PET and 100 non‐PET) on South of Spain. The results confirmed that there is a significant difference in sun exposure during the workday; PET group showed higher exposure (P < 0.01). We ascertained that photoprotection habits are deficient across the population. These data contribute to the understanding of the danger associated with poor sun protection among teachers (primary and secondary school teachers) and its mitigation. It is also worth noting that future prevention campaigns will be necessary for the subsequent correct transmission of the habits to students. 相似文献
2.
Sarah E. Cole Makenzie Hawkins Kimberly A. Miller Martin W. Allen Myles Cockburn 《Photochemistry and photobiology》2023,99(3):1037-1046
Melanoma incidence is increasing, with poor prognosis cases growing faster in California Hispanics than in non-Hispanic whites. Ultraviolet Radiation (UVR) exposure as a child has been found to disproportionately increase the risk of melanoma. To determine correlates of UVR exposure in this high-risk population, we conducted a study in predominately Hispanic 4th and 5th grade classrooms in Los Angeles County, a high UVR environment, during the spring. To address potential reporting bias, electronic UV dosimeters were utilized to objectively measure the association between UVR exposure and constructs (acculturation, sun protective behavior and knowledge, family interventions) obtained on baseline questionnaires (n = 125). Tanning attitude (wanting to get a tan) was associated with lower median time spent outside (1.73 min versus 22.17, AUC 82.08, Sensitivity 0.78, Specificity 0.73) and standard erythemal dose (SED) on weekends, but positively associated with sun protective knowledge. Sun protective knowledge and family discussion of sunscreen were also inversely associated with objectively measured time outside. Students spent a median 30.61 (IQR 19.88) minutes outside per day (SED 0.30, IQR 0.20), with only 35.70% of it occurring in nonschool hours. We determined the majority of UVR exposure in this population occurs at school, providing valuable guidance for future interventions. 相似文献
3.
Ethyl 2-diazo-4,4,4-trifluoro-3-oxobutanoate is a highly versatile intermediate for the synthesis of a wide range of trifluoromethyl heterocycles. With the use of rhodium(II) or copper(II) catalyzed carbene X-H insertion reactions as key steps, a diverse set of trifluoromethyl-oxazoles, -thiazoles, -imidazoles, -1,2,4-triazines, and -pyridines are available from the diazoketoester, either directly in a single step or with just one additional step. 相似文献
4.
Childhood sun exposure is linked to excessive pigmented mole development and melanoma risk. Clothing provides a physical barrier, protecting skin from ultraviolet radiation (UVR). Extending sleeves to elbow length and shorts to knee length has been shown to significantly reduce mole acquisition in preschoolers from tropical Queensland. We used publicly available uniform images and guidelines from primary schools in Townsville (latitude 19.25°S, n = 43 schools), Cairns (16.87°S, n = 46) and the Atherton Tablelands (17.26°S, n = 23) in tropical Australia to objectively determine the body surface proportion covered by regulation school uniforms. Uniforms of nongovernment, large (≥800 students), urban, educationally advantaged schools with comprehensive sun protection policies covered more skin than those of government schools (63.2% vs 62.0%; P < 0.001), smaller schools (63.4% vs 62.3%; P = 0.009), rural (62.7% vs 61.9%; P = 0.002) and educationally disadvantaged schools (62.8% vs 62.3%; P < 0.001) with underdeveloped sun protection policies (62.8% vs 62.2%; P = 0.002). Overall, SunSmart and non‐SunSmart school uniforms covered identical body surface proportions (62.4%, P = 0.084). Although wearing regulation school uniforms is mandatory at most Australian primary schools, this opportunity to improve children's sun protection is largely overlooked. Recent evidence suggests that even encouraging minor alterations to school uniforms (e.g. slightly longer sleeves/dresses/skirts/shorts) to increase skin coverage may reduce mole acquisition and melanoma risk, especially in high‐risk populations. 相似文献
5.
Katarzyna A. Baczynska Luke L. A. Price Michael P. Higlett John B. O'Hagan 《Photochemistry and photobiology》2016,92(1):193-200
Exposure to ultraviolet radiation and sunburn during childhood and adolescence is linked to increased risks of melanoma and basal cell carcinoma later in life. Infants and toddlers are thought to be unusually vulnerable to UVR because of lower levels of melanin, a thinner stratum corneum and a higher surface area/body mass ratio. The aim of this study was to assess variations in the available erythema effective radiant doses to young children in day care nurseries in South Oxfordshire, UK over 7 years between 2008 and 2014. The data were analyzed in three distinct seasons according to a series of realistic exposure scenarios taking into account nursery routines. The results indicate the time of year when high doses are to be expected and provide strong support for arguments in favor of raising public awareness of sun protection earlier in the year. 相似文献
6.
Rachel E. Neale Abbey R. Hamilton Monika Janda Peter Gies Adele C. Green 《Photochemistry and photobiology》2010,86(2):445-448
Generating accurate population-specific public health messages regarding sun protection requires knowledge about seasonal variation in sun exposure in different environments. To address this issue for a subtropical area of Australia, we used polysulphone badges to measure UVR for the township of Nambour (26° latitude) and personal UVR exposure among Nambour residents who were taking part in a skin cancer prevention trial. Badges were worn by participants for two winter and two summer days. The ambient UVR was approximately three times as high in summer as in winter. However, participants received more than twice the proportion of available UVR in winter as in summer (6.5%vs 2.7%, P < 0.05), resulting in an average ratio of summer to winter personal UVR exposure of 1.35. The average absolute difference in daily dose between summer and winter was only one-seventh of a minimal erythemal dose. Extrapolating from our data, we estimate that ca. 42% of the total exposure received in the 6 months of winter (June–August) and summer (December–February) is received during the three winter months. Our data show that in Queensland a substantial proportion of people’s annual UVR dose is obtained in winter, underscoring the need for dissemination of sun protection messages throughout the year in subtropical and tropical climates. 相似文献
7.
Paul D. Scesa Eric W. Schmidt 《Angewandte Chemie (International ed. in English)》2023,62(39):e202311406
Thousands of coral terpenes originate from simple scaffolds that undergo oxidative tailoring. While corals are excellent sources of drug leads, the challenge of supplying structurally complex drug leads from marine organisms has sometimes slowed their development. Making this even more challenging, in comparison to other organisms, such as plants and microbes, for which the terpene literature is substantial, very little is known about how the unique coral terpenes are biosynthesized and elaborated in nature. In this study, we used a semisynthetic strategy to produce at gram scale in yeast the eunicellane scaffold that underlies >200 coral compounds. Synthetic oxidation reactions were explored, generating key scaffolds that reflect three of the four structural classes derived from eunicellane and enabling the first asymmetric syntheses of the natural products solenopodin C and klysimplexin Q. Biomimetic methods and detailed mechanistic studies of synthetic reactions shed light on potential enzymological reactivity, including the role of epoxide rearrangement in eunicellane biosynthesis. 相似文献
8.
Ndidi U. N. Iwumene Daniel. F. Moseley Robert D. C. Pullin Michael C. Willis 《Chemical science》2022,13(5):1504
Rhodium-catalyzed hydroacylation using alkynes substituted with pendant nucleophiles, delivers linear α,β-unsaturated enone intermediates with excellent regioselectivity. These adducts are used to construct a broad range of diversely substituted, saturated O-, N- and S-heterocycles in a one-pot process. Judicious choice of cyclisation conditions enabled isolation of O-heterocycles with high levels of diastereoselectivity. A variety of derivatisation reactions are also performed, generating functionalised hydroacylation products. This sequence serves as a general approach for the synthesis of fully saturated heterocycles.We demonstrate a one-pot hydroacylation/intramolecular conjugate-addition sequence to access a series of complex stereodefined heterocycles. Subsequent diversification of products is achieved, furnishing functionalized sp3-rich fragments. 相似文献
9.
Taizong Wu Angela A. Salim Paul V. Bernhardt Robert J. Capon 《Molecules (Basel, Switzerland)》2022,27(24)
This study showcases the application of an integrated workflow of molecular networking chemical profiling (GNPS), together with miniaturized microbioreactor cultivation profiling (MATRIX) to successfully detect, dereplicate, prioritize, optimize the production, isolate, characterize, and identify a diverse selection of new chemically labile natural products from the Queensland sheep pasture soil-derived fungus Aspergillus sp. CMB-MRF324. More specifically, we report the new tryptamine enamino tripeptide aspergillamides E–F (7–8), dihydroquinoline-2-one aflaquinolones H–I (11–12), and prenylated phenylbutyrolactone aspulvinone Y (14), along with an array of known co-metabolites, including asterriquinones SU5228 (9) and CT5 (10), terrecyclic acid A (13), and aspulvinones N-CR (15), B (16), D (17), and H (18). Structure elucidation was achieved by a combination of detailed spectroscopic and chemical analysis, biosynthetic considerations, and in the case of 11, an X-ray crystallographic analysis. 相似文献
10.
Shuyu Guo Peter Gies Kerryn King Robyn M Lucas 《Photochemistry and photobiology》2014,90(6):1455-1461
Vitamin D deficiency is more common in Northeast‐Asian immigrants to western countries than in the local population; prevalence equalizes as immigrants adopt the host country's culture. In a community‐based study of 100 Northeast‐Asian immigrants in Canberra, Australia, we examined predictors of vitamin D status, its association with indicators of acculturation (English language use; time since migration) and mediators of that association. Participants completed a sun and physical activity diary and wore an electronic ultraviolet radiation (UVR) dosimeter for 7 days. Skin colour was measured by reflectance spectrophotometry. Serum concentrations of 25‐hydroxyvitamin D (25(OH)D) and cardio‐metabolic biomarkers were measured on fasting blood. In a multiple linear regression model, predictors for 25(OH)D concentration were season of blood collection, vitamin D supplementation, UVR exposure, body mass index, physical activity and having private health insurance (R2 = 0.57). Greater acculturation was associated with lower risk of vitamin D deficiency (de‐seasonalized 25(OH)D level <50 nmol L?1) (Adjusted Odds Ratio (AOR): 0.22 [95%CI 0.04–0.96]); this association was statistically mediated by physical activity and time outdoors. Vitamin D deficiency was associated with higher total cholesterol levels (>5.0 mmol L?1) (AOR: 7.48 [95%CI 1.51–37.0]). Targeted public health approaches are required to manage the high prevalence of vitamin D deficiency in migrants retaining a traditional lifestyle. 相似文献
11.
Hartmuth C. Kolb M. G. Finn K. Barry Sharpless 《Angewandte Chemie (International ed. in English)》2001,40(11):2004-2021
Examination of nature's favorite molecules reveals a striking preference for making carbon–heteroatom bonds over carbon–carbon bonds—surely no surprise given that carbon dioxide is nature's starting material and that most reactions are performed in water. Nucleic acids, proteins, and polysaccharides are condensation polymers of small subunits stitched together by carbon–heteroatom bonds. Even the 35 or so building blocks from which these crucial molecules are made each contain, at most, six contiguous C−C bonds, except for the three aromatic amino acids. Taking our cue from nature's approach, we address here the development of a set of powerful, highly reliable, and selective reactions for the rapid synthesis of useful new compounds and combinatorial libraries through heteroatom links (C−X−C), an approach we call “click chemistry”. Click chemistry is at once defined, enabled, and constrained by a handful of nearly perfect “spring‐loaded” reactions. The stringent criteria for a process to earn click chemistry status are described along with examples of the molecular frameworks that are easily made using this spartan, but powerful, synthetic strategy. 相似文献
12.
Rachel C. Chiaroni‐Clarke Jane E. Munro Angela Pezic Joanna E. Cobb Jonathan D. Akikusa Roger C. Allen Terence Dwyer Anne‐Louise Ponsonby Justine A. Ellis 《Photochemistry and photobiology》2019,95(3):867-873
Cutaneous sun exposure is an important determinant of circulating vitamin D. Both sun exposure and vitamin D have been inversely associated with risk of autoimmune disease. In juvenile idiopathic arthritis (JIA), low circulating vitamin D appears common, but disease‐related behavioral changes may have influenced sun exposure. We therefore aimed to determine whether predisease sun exposure is associated with JIA. Using validated questionnaires, we retrospectively measured sun exposure for 202 Caucasian JIA case–control pairs born in Victoria Australia, matched for birth year and time of recruitment. Measures included maternal sun exposure at 12 weeks of pregnancy and child sun exposure across the life‐course prediagnosis. We converted exposure to UVR dose and looked for case–control differences using logistic regression, adjusting for potential confounders. Higher cumulative prediagnosis UVR exposure was associated with reduced risk of JIA, with a clear dose–response relationship (trend P = 0.04). UVR exposure at 12 weeks of pregnancy was similarly inversely associated with JIA (trend P = 0.011). Associations were robust to sensitivity analyses for prediagnosis behavioral changes, disease duration and knowledge of the hypothesis. Our data indicate that lower UVR exposure may increase JIA risk. This may be through decreased circulating vitamin D, but prospective studies are required to confirm this. 相似文献
13.
Gary D. Zhang Lucinda J. Black Matthew N. Cooper Robyn M. Lucas Shelley Gorman 《Photochemistry and photobiology》2019,95(6):1433-1440
Obesity is a significant health problem worldwide. Exposure to low‐dose ultraviolet radiation (like that in sunlight) suppresses the development of obesity in mice; however, the nature of the associations between sun exposure and adiposity is not well understood in humans. The present study characterized cross‐sectional relationships between sun exposure and adiposity in a convenience cohort of breast (n = 269; mean age = 58 years) and prostate (n = 78; mean age = 69 years) cancer patients. Participants were enrolled in a 3‐month exercise program in Perth, Australia. Self‐reported questionnaires measured time spent outdoors (previous week, winter and summer), sex, age, treatment received and physical activity levels. Adiposity measures included body mass index, waist‐hip ratio and body fat percentage (measured via DXA). In unadjusted models, greater time spent outdoors across all times was significantly associated with lower waist‐hip ratio, while greater time spent outdoors in the last winter was associated with lower body fat percentage, but not when stratified by sex. There were no statistically significant associations between time spent outdoors and adiposity after adjusting for sex, age, treatments received and physical activity. Longitudinal studies in larger populations may elucidate significant associations not found in our study due to the cross‐sectional design and power limitations. 相似文献
14.
E. Ann Holmes Rachael M. Rodney Harris Robyn M. Lucas 《Photochemistry and photobiology》2019,95(1):105-118
The incidence and prevalence of inflammatory bowel disease (IBD) are increasing worldwide. Some ecological studies show increasing incidence with increasing latitude. Ambient ultraviolet radiation varies inversely with latitude, and sun exposure of the skin is a major source of vitamin D. Vitamin D deficiency is common in patients with IBD. Sun exposure and vitamin D have immune effects that could plausibly reduce, or be protective for, IBD. One quarter of new IBD cases are diagnosed in childhood or adolescence, but most research is for adult‐onset IBD. Here, we review the evidence for low sun exposure and/or vitamin D deficiency as risk factors for IBD, focusing where possible on pediatric IBD, where effects of environmental exposures may be clearer. The literature provides some evidence of a latitude gradient of IBD incidence, and evidence for seasonal patterns of timing of birth or disease onset is inconsistent. High prevalence of vitamin D deficiency occurs in people with IBD, but cannot be interpreted as being a causal risk factor. Evidence of vitamin D supplementation affecting disease activity is limited. Further research on predisease sun exposure and well‐designed supplementation studies are required to elucidate whether these potentially modifiable exposures are indeed risk factors for IBD. 相似文献
15.
Skovsen E Snyder JW Lambert JD Ogilby PR 《The journal of physical chemistry. B》2005,109(18):8570-8573
In time- and spatially resolved experiments, singlet molecular oxygen, O(2)(a(1)Delta(g)), was created in a single nerve cell upon irradiation of a sensitizer incorporated in the cell nucleus using a focused laser beam. The singlet oxygen thus produced was detected by its infrared phosphorescence. Data obtained indicate that, contrary to common perception, this reactive species can be quite long-lived in a cell and, as such, can diffuse over appreciable distances including across the cell membrane into the extra-cellular environment. These results provide a new perspective for mechanistic studies of photoinduced cell death and intracellular signaling. 相似文献
16.
17.
系统考察质子交换膜燃料电池组装(锁紧力,0.45~11.3 MPa)对其性能和寿命的影响,并确定了最佳锁紧力.以最佳锁紧力(3.2 MPa)的单电池作2000 h寿命测试,根据该单电池不同运行时间下的极化和功率曲线分析,得到与其活化区对应的电化学参数.XRD检测表明,电池组装施加的锁紧力不但影响电池的接触电阻,而且还影响由MEA微观结构决定的电池反应动力学性能.在最佳锁紧力作用下运行2000 h后的单电池在大电流密度区出现了明显的性能衰减,这主要是由于催化剂的团聚效应引起的.但在非最佳锁紧力作用下,阴极催化剂的团聚作用远大于阳极催化剂. 相似文献
18.
Ratnayake R Lacey E Tennant S Gill JH Capon RJ 《Chemistry (Weinheim an der Bergstrasse, Germany)》2007,13(5):1610-1619
The kibdelones are a novel family of bioactive heterocyclic polyketides produced by a rare soil actinomycete, Kibdelosporangium sp. (MST-108465). Complete relative stereostructures were assigned to kibdelones A-C (1-3), kibdelone B rhamnoside (5), 13-oxokibdelone A (7), and 25-methoxy-24-oxokibdelone C (8) on the basis of detailed spectroscopic analysis and chemical interconversion, as well as mechanistic and biosynthetic considerations. Under mild conditions, kibdelones B (2) and C (3) undergo a facile equilibration to kibdelones A-C (1-3), while kibdelone B rhamnoside (5) equilibrates to a mixture of kibdelone A-C rhamnosides (4-6). A plausible mechanism for this equilibration is proposed and involves air oxidation, quinone/hydroquinone redox transformations, and a choreographed sequence of keto/enol tautomerizations that aromatize ring C via a quinone methide intermediate. Kibdelones exhibit potent and selective cytotoxicity against a panel of human tumor cell lines and display significant antibacterial and nematocidal activity. 相似文献
19.
Mahlako Malesele Nkogatse Motsehoa Cynthia Ramotsehoa Frederick Christofel Eloff Caradee Yael Wright 《Photochemistry and photobiology》2019,95(1):439-445
The exposure of outdoor car guards to solar ultraviolet radiation (UVR), the majority with deeply pigmented skin, to solar UVR was measured for five consecutive days during early spring (September 2017) in South Africa using electronic UVR dosimeters attached to the upper arm of each participant. The exposure of the nape of the neck, forehead, nose, cheek and hand was extrapolated from the measurements. The onsite ambient solar UVR on a flat, horizontal, unshaded surface was measured concurrently. The sun‐related knowledge, behavior and attitudes of the car guards were evaluated using questionnaires. Total personal daily solar UVR exposure as a percentage of the ambient solar UVR exposure was 24%. The exposure of car guards on several body sites was in excess of the occupational threshold limit value. Sleeved shirts and hats were the most commonly used sun protection measures (worn by 70% and 80%, respectively). Considering the high levels of solar UVR reported on most days throughout the year in South Africa, more studies quantifying the personal exposure of outdoor workers in both the informal and formal sectors are necessary. 相似文献
20.
Dr. Emma C. Barnes Dr. Juangjun Jumpathong Prof. Saisamorn Lumyong Priv.‐Doz. Dr. Kerstin Voigt Prof. Dr. Christian Hertweck 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(13):4551-4555
Thailand possesses a rich diversity of orchid species that, in turn, live in symbiosis with a wide variety of fungi. Such endophytes have the potential to produce secondary metabolites with bioactivity against orchid and/or human pathogens. The orchid‐associated fungal strain Daldinia eschscholtzii was found to produce a diverse range of aromatic polyketides including the new naphthalene derivatives daldionin, nodulones B and C, and daldinones F and G along with eight known compounds. Daldionin possesses an unprecedented oxane‐linked binaphthyl ring system. These compounds demonstrate the high diversity of structural variations that are constructed during fungal biosynthesis, and the results include important observations concerning the biosynthesis of binaphthyl derivatives. Daldionin was found to have weak antiproliferative activity against HUVEC and K‐562 cell lines. All but one of the isolated compounds showed moderate antimicrobial activity towards at least one of the four tested microbial strains. 相似文献