We evaluated the effects of red and blue light on the repair of UV-B radiation-induced damage in tetraspores of Chondrus ocellatus Holm. Tetraspores of C. ocellatus were treated with different UV-B radiation levels(0,...We evaluated the effects of red and blue light on the repair of UV-B radiation-induced damage in tetraspores of Chondrus ocellatus Holm. Tetraspores of C. ocellatus were treated with different UV-B radiation levels(0,36,72,108,144 and 180 J/m2),and thereafter subjected to PAR,darkness,or red or blue light during a 2-h repair stage,each day for 48 days. The diameters and cellular contents of cyclobutane pyrimidine dimmers(CPDs),chlorophyll a(Chl a),phycoerythrin,and UV-B-absorbing mycosporinelike amino acids(MAAs) contents of the tetraspores were determined. Our results show that low doses of UV-B radiation(36 and 72 J/m 2) promoted the growth of C. ocellatus; however,increased UV-B radiation gradually reduced the C. ocellatus growth(greater than 72 J/m2). The MAAs(palythine and asterina-330) in C. ocellatus were detected and analyzed by LC/MS. Our results suggest that moderate red light could induce the growth of this alga in aquaculture. In addition,photorepair was inhibited by red light,so there may be some other DNA repair mechanism activated by red light. Blue light promoted the activity of DNA photolyase,greatly improving remediation efficiency. Red and blue lights were found to reduce the capacity of C. ocellatus to form MAAs. Therefore,PAR,red light,and blue light play different roles during the repair processes for damage induced by UV-B radiation.展开更多
This study assessed the feasibility of developing a machine vision system equipped with ultraviolet (UV) light, using changes in fish-surface color to predict aerobic plate count (APC, a standard freshness indicator) ...This study assessed the feasibility of developing a machine vision system equipped with ultraviolet (UV) light, using changes in fish-surface color to predict aerobic plate count (APC, a standard freshness indicator) during storage. The APC values were tested and images of the fish surface were taken when fish were stored at room temperature. Then, images</span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">’</span></span></span><span><span><span><span> color-space conversion among RGB, HSV, and L*a*b* color spaces was carried out and analyzed. The results revealed that a* and b* values from the UV-light image decreased linearly during storage. A further regression analysis of these two parameters with APC value demonstrated a good exponential relationship between the a* value and the APC value (R</span><sup><span>2</span></sup><span> = 0.97), followed by the b* (R</span><sup><span>2</span></sup><span> = 0.85). Therefore, our results suggest that the change in color of the fish surface under UV light can be used to assess fish freshness during storage.展开更多
After comparison of Trichoderma population density and test of colonization ability in rhizospheres were conducted. Auxotrophic mutants of T. harzianum tolerant to carbendazim and UV-light were obtained by UV-light mu...After comparison of Trichoderma population density and test of colonization ability in rhizospheres were conducted. Auxotrophic mutants of T. harzianum tolerant to carbendazim and UV-light were obtained by UV-light mutagenesis and carbendazim stress on PDA medium and a basis medium with hot pepper root exudation by adding the fungicide. The results showed: all four different isolates of Trichoderma had certain colonization ability in rhizosphere with the characteristic of growing as roots and distributing many more around root tips. The ability, however, was different for the 4 isolates, showing the wild isolates colonized weakly in rhizosphere. Around 5% spores alive and mutants could be obtained after the isolates were irradiated under a 20W UV-light at 25 cm distance for 5 min. The mutants tolerant to carbendazim were screened out by adding the fungicide into PDA medium, which increased resistance to the fungicide 100 times higher than their original isolates and showed auxotrophic. Three mutants,G7n,G20n and G5n, grew very well on PDA and a basic medium with hot pepper root exudation. Therefore, these mutants could be used as the isolates with good colonization ability for further research.展开更多
Syntheses of zince oxide（ZnO） nanoparticles by direct precipitation and surface modification with oleic acid were reported. ZnO nanoparticles were characterized via X-ray diffractometry（XRD）, transmission electron...Syntheses of zince oxide（ZnO） nanoparticles by direct precipitation and surface modification with oleic acid were reported. ZnO nanoparticles were characterized via X-ray diffractometry（XRD）, transmission electron microscopy（TEM）, infrared spectroscopy（IR） and UV-Vis spectroscopy. The prepared ZnO nanoparticles were nearly spherical and highly crystalline with an average size of 29 nm. In addition, high UV-light absorption properties of oleic acid surface modified ZnO nanoparticles were successfully obtained for a dispersion of ZnO nanoparticles in ethanol.展开更多
Based on previous work, it has been hypothesized that the energetics of ultraviolet (UV) light disrupts effects induced by receptor-binding ligands. If this hypothesis is true, then UV light should (i) disrupt a broad...Based on previous work, it has been hypothesized that the energetics of ultraviolet (UV) light disrupts effects induced by receptor-binding ligands. If this hypothesis is true, then UV light should (i) disrupt a broad variety of endpoints and (ii) disrupt effects produced by ligands that bind to diverse receptor types. This was tested directly in the present study by using ligands selective for four different receptors (one ionotropic, three metabotropic) and three different behavioral endpoints. The selective dopamine D2 receptor antagonist (–)sulpiride (0.1 uM) dose-relatedly decreased spontaneous locomotor velocity, the selective nicotinic acetylcholine receptor agonist nicotine (1, 3, 5 mM) and the selective muscarinic acetylcholine receptor agonist pilocarpine (20, 30, 50 mM) induced seizure-like activity, and the selective-opioid receptor agonist U-50,488H (10 uM) produced physical dependence (manifested as abstinence-induced withdrawal) in planarian models. Each of these diverse ligand and receptor-mediated effects were attenuated by UV light (254 nm = 7.83 × 10–19 J = 4.89 eV). These findings provide further evidence that UV light disrupts ligand-receptor mediated interactions and that UV light might provide a useful tool for examining drug-receptor interactions.展开更多
High qualityβ-Ga_(2)O_(3)single crystal nanobelts with length of 2−3 mm and width from tens of microns to 132μm were synthesized by carbothermal reduction method.Based on the grown nanobelt with the length of 600μm...High qualityβ-Ga_(2)O_(3)single crystal nanobelts with length of 2−3 mm and width from tens of microns to 132μm were synthesized by carbothermal reduction method.Based on the grown nanobelt with the length of 600μm,the dual-Schottky-junctions coupling device(DSCD)was fabricated.Due to the electrically floating Ga_(2)O_(3)nanobelt region coupling with the double Schottky-junctions,the current I_(S2)increases firstly and rapidly reaches into saturation as increase the voltage V_(S2).The saturation current is about 10 pA,which is two orders of magnitude lower than that of a single Schottky-junction.In the case of solar-blind ultraviolet(UV)light irradiation,the photogenerated electrons further aggravate the coupling physical mechanism in device.I_(S2)increases as the intensity of UV light increases.Under the UV light of 1820μW/cm^(2),I_(S2)quickly enters the saturation state.At V_(S2)=10 V,photo-to-dark current ratio(PDCR)of the device reaches more than 104,the external quantum efficiency(EQE)is 1.6×10^(3)%,and the detectivity(D*)is 7.5×10^(12)Jones.In addition,the device has a very short rise and decay times of 25−54 ms under different positive and negative bias.DSCD shows unique electrical and optical control characteristics,which will open a new way for the application of nanobelt-based devices.展开更多
Understanding chemical transformations of contaminants and the resulting products is extremely important in devising proper monitoring methods for such contaminants and in assessing potential human exposure to the tra...Understanding chemical transformations of contaminants and the resulting products is extremely important in devising proper monitoring methods for such contaminants and in assessing potential human exposure to the transformation products in the environment. Ultraviolet (UV) light from the sun can induce various photochemical transformations of contaminants in the environment. Alkylnaphthalenes are light-molecular-weight polycyclic aromatic hydrocarbons (PAHs) which are one of the most widespread organic pollutants present in ambient air as a result of a variety of incomplete combustion sources. In this study, 1-methylnapthalene,a typical example of an alkylnaphthalene, was subjected to UV irradiation to investigate its transformation in the presence and absence of air. Twenty-one products were detected in the reaction mixtures. Some photo-oxidation products were identified, including both ring-opened and ring-retained oxygenated compounds, such as 1-naphthaldehyde, 1-naphthoic acid, 1-naphthalenemethanol and phthalic anhydride. Although dimeric products were observed in the presence of air, more were found in the presence of helium or argon gas, indicating a different photo-oxidation pathway from those commonly observed in other media, such as water. Under just 48 hours of exposure to the UV light in the presence of air, three major products were formed with a production yield of about 10% each. Compared to 1-methylnapthalene, the UV induced transformation products observed in this study are more volatile, acidic, water soluble or toxic. The formation of these products may significantly change our understanding of the risks assessed solely from the parent compound in contaminants research and supports the inclusion of airborne transformations of the parent compound in risk assessment.展开更多
We evaluated the effects of ultraviolet-B(UV-B) radiation and different light conditions on the repair of UV-B-induced damage in carpospores of C hondrus ocellatus Holm(Rhodophyta) in laboratory experiments. Carpospor...We evaluated the effects of ultraviolet-B(UV-B) radiation and different light conditions on the repair of UV-B-induced damage in carpospores of C hondrus ocellatus Holm(Rhodophyta) in laboratory experiments. Carpospores were treated daily with different doses of UV-B radiation for 48 days,when vertical branches had formed in all treatments; after each daily treatment,the carpospores were subjected to photosynthetically active radiation(PAR),darkness,red light,or blue light during a 2-h repair stage. Carpospore diameters were measured every 4 days. We measured the growth and cellular contents of cyclobutane pyrimidine dimers(CPDs),chlorophyll a,phycoerythrin,and UV-B-absorbing mycosporine-like amino acids(MAAs) in carpospores on Day 48. Low doses of UV-B radiation(36 and 72 J/m 2) accelerated the growth of C. ocellatus. However,as the amount of UV-B radiation increased,the growth rate decreased and morphological changes occurred. UV-B radiation significant damaged DNA and photosynthetic pigments and induced three kind of MAAs,palythine,asterina-330,and shinorine. PAR conditions were best for repairing UV-B-induced damage. Darkness promoted the activity of the DNA darkrepair mechanism. Red light enhanced phycoerythrin synthesis but inhibited light repair of DNA. Although blue light,increased the activity of DNA photolyase,greatly improving remediation efficiency,the growth and development of C. ocellatus carpospores were slower than in other light treatments.展开更多
To explore the method of evaluating the soothing effect of human skin damage,a human skin damage model was established using UV light induction.Four test areas were set up,namely blank control area,UV damage preventio...To explore the method of evaluating the soothing effect of human skin damage,a human skin damage model was established using UV light induction.Four test areas were set up,namely blank control area,UV damage prevention and soothing area,immediate soothing area after UV damage and soothing area after UV damage.Five skin parameters,including skin melanin,red pigment value,skin pigmentation value,a*value,and skin redness value,were used to characterize skin pigmentation before and after using the sample Changes in properties such as skin erythema and skin pigment.The results showed that the method showed significant changes in the skin condition of volunteers before and after using the sample,and could achieve a soothing effect,which has certain reference significance.展开更多
基金Supported by the Program for New Century Excellent Talents in University(No.NCET-05-0597)the National Natural Science Foundation of China(No.30270258)
文摘We evaluated the effects of red and blue light on the repair of UV-B radiation-induced damage in tetraspores of Chondrus ocellatus Holm. Tetraspores of C. ocellatus were treated with different UV-B radiation levels(0,36,72,108,144 and 180 J/m2),and thereafter subjected to PAR,darkness,or red or blue light during a 2-h repair stage,each day for 48 days. The diameters and cellular contents of cyclobutane pyrimidine dimmers(CPDs),chlorophyll a(Chl a),phycoerythrin,and UV-B-absorbing mycosporinelike amino acids(MAAs) contents of the tetraspores were determined. Our results show that low doses of UV-B radiation(36 and 72 J/m 2) promoted the growth of C. ocellatus; however,increased UV-B radiation gradually reduced the C. ocellatus growth(greater than 72 J/m2). The MAAs(palythine and asterina-330) in C. ocellatus were detected and analyzed by LC/MS. Our results suggest that moderate red light could induce the growth of this alga in aquaculture. In addition,photorepair was inhibited by red light,so there may be some other DNA repair mechanism activated by red light. Blue light promoted the activity of DNA photolyase,greatly improving remediation efficiency. Red and blue lights were found to reduce the capacity of C. ocellatus to form MAAs. Therefore,PAR,red light,and blue light play different roles during the repair processes for damage induced by UV-B radiation.
文摘This study assessed the feasibility of developing a machine vision system equipped with ultraviolet (UV) light, using changes in fish-surface color to predict aerobic plate count (APC, a standard freshness indicator) during storage. The APC values were tested and images of the fish surface were taken when fish were stored at room temperature. Then, images</span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">’</span></span></span><span><span><span><span> color-space conversion among RGB, HSV, and L*a*b* color spaces was carried out and analyzed. The results revealed that a* and b* values from the UV-light image decreased linearly during storage. A further regression analysis of these two parameters with APC value demonstrated a good exponential relationship between the a* value and the APC value (R</span><sup><span>2</span></sup><span> = 0.97), followed by the b* (R</span><sup><span>2</span></sup><span> = 0.85). Therefore, our results suggest that the change in color of the fish surface under UV light can be used to assess fish freshness during storage.
文摘After comparison of Trichoderma population density and test of colonization ability in rhizospheres were conducted. Auxotrophic mutants of T. harzianum tolerant to carbendazim and UV-light were obtained by UV-light mutagenesis and carbendazim stress on PDA medium and a basis medium with hot pepper root exudation by adding the fungicide. The results showed: all four different isolates of Trichoderma had certain colonization ability in rhizosphere with the characteristic of growing as roots and distributing many more around root tips. The ability, however, was different for the 4 isolates, showing the wild isolates colonized weakly in rhizosphere. Around 5% spores alive and mutants could be obtained after the isolates were irradiated under a 20W UV-light at 25 cm distance for 5 min. The mutants tolerant to carbendazim were screened out by adding the fungicide into PDA medium, which increased resistance to the fungicide 100 times higher than their original isolates and showed auxotrophic. Three mutants,G7n,G20n and G5n, grew very well on PDA and a basic medium with hot pepper root exudation. Therefore, these mutants could be used as the isolates with good colonization ability for further research.
基金Supported by the Key Project of the National Eleventh Five-Year Research Programe of China(No.2008BAE66B00)
文摘Syntheses of zince oxide（ZnO） nanoparticles by direct precipitation and surface modification with oleic acid were reported. ZnO nanoparticles were characterized via X-ray diffractometry（XRD）, transmission electron microscopy（TEM）, infrared spectroscopy（IR） and UV-Vis spectroscopy. The prepared ZnO nanoparticles were nearly spherical and highly crystalline with an average size of 29 nm. In addition, high UV-light absorption properties of oleic acid surface modified ZnO nanoparticles were successfully obtained for a dispersion of ZnO nanoparticles in ethanol.
文摘Based on previous work, it has been hypothesized that the energetics of ultraviolet (UV) light disrupts effects induced by receptor-binding ligands. If this hypothesis is true, then UV light should (i) disrupt a broad variety of endpoints and (ii) disrupt effects produced by ligands that bind to diverse receptor types. This was tested directly in the present study by using ligands selective for four different receptors (one ionotropic, three metabotropic) and three different behavioral endpoints. The selective dopamine D2 receptor antagonist (–)sulpiride (0.1 uM) dose-relatedly decreased spontaneous locomotor velocity, the selective nicotinic acetylcholine receptor agonist nicotine (1, 3, 5 mM) and the selective muscarinic acetylcholine receptor agonist pilocarpine (20, 30, 50 mM) induced seizure-like activity, and the selective-opioid receptor agonist U-50,488H (10 uM) produced physical dependence (manifested as abstinence-induced withdrawal) in planarian models. Each of these diverse ligand and receptor-mediated effects were attenuated by UV light (254 nm = 7.83 × 10–19 J = 4.89 eV). These findings provide further evidence that UV light disrupts ligand-receptor mediated interactions and that UV light might provide a useful tool for examining drug-receptor interactions.
基金supported by Natural Science Basic Research Program in Shaanxi Province of China(No.2023-JCYB-574)National Natural Science Foundation of China(No.62204203).
文摘High qualityβ-Ga_(2)O_(3)single crystal nanobelts with length of 2−3 mm and width from tens of microns to 132μm were synthesized by carbothermal reduction method.Based on the grown nanobelt with the length of 600μm,the dual-Schottky-junctions coupling device(DSCD)was fabricated.Due to the electrically floating Ga_(2)O_(3)nanobelt region coupling with the double Schottky-junctions,the current I_(S2)increases firstly and rapidly reaches into saturation as increase the voltage V_(S2).The saturation current is about 10 pA,which is two orders of magnitude lower than that of a single Schottky-junction.In the case of solar-blind ultraviolet(UV)light irradiation,the photogenerated electrons further aggravate the coupling physical mechanism in device.I_(S2)increases as the intensity of UV light increases.Under the UV light of 1820μW/cm^(2),I_(S2)quickly enters the saturation state.At V_(S2)=10 V,photo-to-dark current ratio(PDCR)of the device reaches more than 104,the external quantum efficiency(EQE)is 1.6×10^(3)%,and the detectivity(D*)is 7.5×10^(12)Jones.In addition,the device has a very short rise and decay times of 25−54 ms under different positive and negative bias.DSCD shows unique electrical and optical control characteristics,which will open a new way for the application of nanobelt-based devices.
文摘Understanding chemical transformations of contaminants and the resulting products is extremely important in devising proper monitoring methods for such contaminants and in assessing potential human exposure to the transformation products in the environment. Ultraviolet (UV) light from the sun can induce various photochemical transformations of contaminants in the environment. Alkylnaphthalenes are light-molecular-weight polycyclic aromatic hydrocarbons (PAHs) which are one of the most widespread organic pollutants present in ambient air as a result of a variety of incomplete combustion sources. In this study, 1-methylnapthalene,a typical example of an alkylnaphthalene, was subjected to UV irradiation to investigate its transformation in the presence and absence of air. Twenty-one products were detected in the reaction mixtures. Some photo-oxidation products were identified, including both ring-opened and ring-retained oxygenated compounds, such as 1-naphthaldehyde, 1-naphthoic acid, 1-naphthalenemethanol and phthalic anhydride. Although dimeric products were observed in the presence of air, more were found in the presence of helium or argon gas, indicating a different photo-oxidation pathway from those commonly observed in other media, such as water. Under just 48 hours of exposure to the UV light in the presence of air, three major products were formed with a production yield of about 10% each. Compared to 1-methylnapthalene, the UV induced transformation products observed in this study are more volatile, acidic, water soluble or toxic. The formation of these products may significantly change our understanding of the risks assessed solely from the parent compound in contaminants research and supports the inclusion of airborne transformations of the parent compound in risk assessment.
基金Supported by the Program for New Century Excellent Talents in University(No.NCET-05-0597)the National Natural Science Foundation of China(No.30270258)
文摘We evaluated the effects of ultraviolet-B(UV-B) radiation and different light conditions on the repair of UV-B-induced damage in carpospores of C hondrus ocellatus Holm(Rhodophyta) in laboratory experiments. Carpospores were treated daily with different doses of UV-B radiation for 48 days,when vertical branches had formed in all treatments; after each daily treatment,the carpospores were subjected to photosynthetically active radiation(PAR),darkness,red light,or blue light during a 2-h repair stage. Carpospore diameters were measured every 4 days. We measured the growth and cellular contents of cyclobutane pyrimidine dimers(CPDs),chlorophyll a,phycoerythrin,and UV-B-absorbing mycosporine-like amino acids(MAAs) in carpospores on Day 48. Low doses of UV-B radiation(36 and 72 J/m 2) accelerated the growth of C. ocellatus. However,as the amount of UV-B radiation increased,the growth rate decreased and morphological changes occurred. UV-B radiation significant damaged DNA and photosynthetic pigments and induced three kind of MAAs,palythine,asterina-330,and shinorine. PAR conditions were best for repairing UV-B-induced damage. Darkness promoted the activity of the DNA darkrepair mechanism. Red light enhanced phycoerythrin synthesis but inhibited light repair of DNA. Although blue light,increased the activity of DNA photolyase,greatly improving remediation efficiency,the growth and development of C. ocellatus carpospores were slower than in other light treatments.
文摘To explore the method of evaluating the soothing effect of human skin damage,a human skin damage model was established using UV light induction.Four test areas were set up,namely blank control area,UV damage prevention and soothing area,immediate soothing area after UV damage and soothing area after UV damage.Five skin parameters,including skin melanin,red pigment value,skin pigmentation value,a*value,and skin redness value,were used to characterize skin pigmentation before and after using the sample Changes in properties such as skin erythema and skin pigment.The results showed that the method showed significant changes in the skin condition of volunteers before and after using the sample,and could achieve a soothing effect,which has certain reference significance.
