为提高鲜切苹果的贮藏品质,以吉县红富士苹果为原料,采用UVC照射结合大豆分离蛋白(Soy protein isolate,SPI)涂膜的方式对鲜切苹果进行处理,研究其对贮藏期内鲜切苹果品质的影响。实验结果表明,在整个贮藏期内,UVC照射结合SPI涂膜处理...为提高鲜切苹果的贮藏品质,以吉县红富士苹果为原料,采用UVC照射结合大豆分离蛋白(Soy protein isolate,SPI)涂膜的方式对鲜切苹果进行处理,研究其对贮藏期内鲜切苹果品质的影响。实验结果表明,在整个贮藏期内,UVC照射结合SPI涂膜处理鲜切苹果与对照组相比,显著抑制了微生物的生长、维持其感官品质、减缓了营养品质的流失以及降低了抗氧化相关酶活性。其中,经SPI+UVC 10 min处理后的鲜切苹果在贮藏5 d后,其失重率仅为2.1%,硬度、Vc含量、可溶性固形物比贮藏前分别仅下降16.4%、28.2%、18.5%,褐变度、POD酶、PPO酶活性、菌落总数分别为对照组的53.4%、65.2%、51.7%、48.9%,此时其可接受度评分为9分,仍具有一定的商品性,相比对照组将鲜切苹果的货架期延长了66%。展开更多
Objective Alkaline comet assay was used to evaluate DNA repair (nucleotide excision repair, NER) capacity of human fresh lymphocytes from 12 young healthy non-smokers (6 males and 6 females). Methods Lymphocytes were ...Objective Alkaline comet assay was used to evaluate DNA repair (nucleotide excision repair, NER) capacity of human fresh lymphocytes from 12 young healthy non-smokers (6 males and 6 females). Methods Lymphocytes were exposed to UV-C (254 nm) at the dose rate of 1.5 J/m2/sec. Novobiocin (NOV) and aphidicolin (APC), DNA repair inhibitors, were utilized to imitate the deficiency of DNA repair capacity at the incision and ligation steps of NER. Lymphocytes from each donor were divided into three grougs: UVC group, UVC plus NOV group, and UVC plus APC group. DNA single strand breaks were detected in UVC irradiated cells incubated for 0, 30, 60, 90, 120, 180, and 240 min after UVC irradiation. DNA repair rate (DRR) served as an indicator of DNA repair capacity. Results The results indicated that the maximum DNA damage (i.e. maximum tail length) in the UVC group mainly appeared at 90 min. The ranges of DRRs in the UVC group were 62.84%-98.71%. Average DRR value was 81.84%. The DRR difference between males and females was not significant (P<0.05). However, the average DRR value in the UVC plus NOV group and the UVC plus APC group was 52.98% and 39.57% respectively, which were significantly lower than that in the UVC group (P<0.01). Conclusion The comet assay is a rapid, simple and sensitive screening test to assess individual DNA repair (NER) capacity. It is suggested that the time to detect DNA single strand breaks in comet assay should include 0 (before UV irradiation), 90 and 240 min after exposure to 1.5 J·m-2 UVC at least. The DRR, as an indicator, can represent the individual DNA repair capacity in comet assay.展开更多
Ultraviolet radiation by its wavelength is divided into: UVA, UVB and UVC. Only UVA and UVB manage to penetrate the ozone layer, but due to anthropological activities, all of them are capable of interacting with human...Ultraviolet radiation by its wavelength is divided into: UVA, UVB and UVC. Only UVA and UVB manage to penetrate the ozone layer, but due to anthropological activities, all of them are capable of interacting with humans to a greater or lesser extent, and can generate adverse effects such as cellular stress when interacting with intra-and extracellular biomolecules. The skin is the first organ in contact with UV radiation, and the stress it generates can be analyzed by the expression of a bioindicator of cellular damage such as Hsp70. Therefore, the objective of the project was: to determine the effect of UVA, UVB and UVC radiation on HaCaT epithelial cells, by analyzing the expression of Hsp70. Materials and methods: HaCaT cells were cultured in vitro, which were irradiated with UVA, UVB and UVC light at different doses, to subsequently determine the degree of Hsp70 expression by Immunodetection by PAGE-SDS and Western Blot. Results: Basal expression of Hsp70 was observed in no irradiated HaCaT cells. When HaCaT cells were irradiated with UVA, UVB, UVC, an increase in this Hsp70 protein was observed. With UVA, a higher degree of expression was observed at a time of 30 minutes of irradiation. With UVB the highest expression shifted to a time of 20 minutes. With UVC, overexpression was observed after 10 minutes. Conclusion: UV radiation generates cellular stress on HaCaT cells, evaluated by the stress bioindicator Hsp70. According to the wavelength of UV radiation, those that have a shorter wavelength have a greater potential for cellular damage, such as UVC.展开更多
A ten-month field research study was meticulously conducted at Robert Moses State Park (RMSP) on the south shore of Long Island, NY. The objective was to determine if aerial phenomena of an unknown nature exist over a...A ten-month field research study was meticulously conducted at Robert Moses State Park (RMSP) on the south shore of Long Island, NY. The objective was to determine if aerial phenomena of an unknown nature exist over a coastal location and to characterize their properties and behaviors. Primary and secondary field observation methods were utilized in this data-centric study. Forensic engineering principles and methodologies guided the study. The challenges set forward were object detection, observation, and characterization, where multispectral electro-optical devices and radar were employed due to limited visual acuity and intermittent presentation of the phenomena. The primary means of detection utilized a 3 cm X-band radar operating in two scan geometries, the X- and Y-axis. Multispectral electro-optical devices were utilized as a secondary means of detection and identification. Data was emphasized using HF and LF detectors and spectrum analyzers incorporating EM, ultrasonic, magnetic, and RF field transducers to record spectral data in these domains. Data collection concentrated on characterizing VIS, NIR, SWIR, LWIR, UVA, UVB, UVC, and the higher energy spectral range of ionizing radiation (alpha, beta, gamma, and X-ray) recorded by Geiger-Müller counters as well as special purpose semiconductor diode sensors.展开更多
目的:研究沙棘(Hippophae rhamnoides L.)水提物对短波紫外线(UVC)辐射人永生化角质形成(Ha Ca T)细胞增殖与凋亡、线粒体膜电位(ΔΨm)的影响,探讨沙棘水提物对UVC辐射Ha Ca T细胞是否具有防护功能及其作用机制。方法:体外培养Ha Ca T...目的:研究沙棘(Hippophae rhamnoides L.)水提物对短波紫外线(UVC)辐射人永生化角质形成(Ha Ca T)细胞增殖与凋亡、线粒体膜电位(ΔΨm)的影响,探讨沙棘水提物对UVC辐射Ha Ca T细胞是否具有防护功能及其作用机制。方法:体外培养Ha Ca T细胞株,设置对照组(不加药、不照射)、UVC组和药物组(UVC辐射+不同浓度的沙棘水提物),CCK-8法测定细胞增殖、Annexin V/PI流式细胞术检测细胞凋亡、JC-1检测ΔΨm。结果:与UVC组比较,药物组CCK-8吸光度值(OD值)明显升高(P<0.01),且呈剂量依赖;细胞凋亡率降低,发生线粒体膜电位下降的细胞数比例(F值)下降。结论:沙棘水提物能够抑制Ha Ca T细胞凋亡、促进细胞增殖,其机制可能与保护线粒体功能有关。展开更多
文摘Objective Alkaline comet assay was used to evaluate DNA repair (nucleotide excision repair, NER) capacity of human fresh lymphocytes from 12 young healthy non-smokers (6 males and 6 females). Methods Lymphocytes were exposed to UV-C (254 nm) at the dose rate of 1.5 J/m2/sec. Novobiocin (NOV) and aphidicolin (APC), DNA repair inhibitors, were utilized to imitate the deficiency of DNA repair capacity at the incision and ligation steps of NER. Lymphocytes from each donor were divided into three grougs: UVC group, UVC plus NOV group, and UVC plus APC group. DNA single strand breaks were detected in UVC irradiated cells incubated for 0, 30, 60, 90, 120, 180, and 240 min after UVC irradiation. DNA repair rate (DRR) served as an indicator of DNA repair capacity. Results The results indicated that the maximum DNA damage (i.e. maximum tail length) in the UVC group mainly appeared at 90 min. The ranges of DRRs in the UVC group were 62.84%-98.71%. Average DRR value was 81.84%. The DRR difference between males and females was not significant (P<0.05). However, the average DRR value in the UVC plus NOV group and the UVC plus APC group was 52.98% and 39.57% respectively, which were significantly lower than that in the UVC group (P<0.01). Conclusion The comet assay is a rapid, simple and sensitive screening test to assess individual DNA repair (NER) capacity. It is suggested that the time to detect DNA single strand breaks in comet assay should include 0 (before UV irradiation), 90 and 240 min after exposure to 1.5 J·m-2 UVC at least. The DRR, as an indicator, can represent the individual DNA repair capacity in comet assay.
文摘Ultraviolet radiation by its wavelength is divided into: UVA, UVB and UVC. Only UVA and UVB manage to penetrate the ozone layer, but due to anthropological activities, all of them are capable of interacting with humans to a greater or lesser extent, and can generate adverse effects such as cellular stress when interacting with intra-and extracellular biomolecules. The skin is the first organ in contact with UV radiation, and the stress it generates can be analyzed by the expression of a bioindicator of cellular damage such as Hsp70. Therefore, the objective of the project was: to determine the effect of UVA, UVB and UVC radiation on HaCaT epithelial cells, by analyzing the expression of Hsp70. Materials and methods: HaCaT cells were cultured in vitro, which were irradiated with UVA, UVB and UVC light at different doses, to subsequently determine the degree of Hsp70 expression by Immunodetection by PAGE-SDS and Western Blot. Results: Basal expression of Hsp70 was observed in no irradiated HaCaT cells. When HaCaT cells were irradiated with UVA, UVB, UVC, an increase in this Hsp70 protein was observed. With UVA, a higher degree of expression was observed at a time of 30 minutes of irradiation. With UVB the highest expression shifted to a time of 20 minutes. With UVC, overexpression was observed after 10 minutes. Conclusion: UV radiation generates cellular stress on HaCaT cells, evaluated by the stress bioindicator Hsp70. According to the wavelength of UV radiation, those that have a shorter wavelength have a greater potential for cellular damage, such as UVC.
文摘A ten-month field research study was meticulously conducted at Robert Moses State Park (RMSP) on the south shore of Long Island, NY. The objective was to determine if aerial phenomena of an unknown nature exist over a coastal location and to characterize their properties and behaviors. Primary and secondary field observation methods were utilized in this data-centric study. Forensic engineering principles and methodologies guided the study. The challenges set forward were object detection, observation, and characterization, where multispectral electro-optical devices and radar were employed due to limited visual acuity and intermittent presentation of the phenomena. The primary means of detection utilized a 3 cm X-band radar operating in two scan geometries, the X- and Y-axis. Multispectral electro-optical devices were utilized as a secondary means of detection and identification. Data was emphasized using HF and LF detectors and spectrum analyzers incorporating EM, ultrasonic, magnetic, and RF field transducers to record spectral data in these domains. Data collection concentrated on characterizing VIS, NIR, SWIR, LWIR, UVA, UVB, UVC, and the higher energy spectral range of ionizing radiation (alpha, beta, gamma, and X-ray) recorded by Geiger-Müller counters as well as special purpose semiconductor diode sensors.
文摘目的:研究沙棘(Hippophae rhamnoides L.)水提物对短波紫外线(UVC)辐射人永生化角质形成(Ha Ca T)细胞增殖与凋亡、线粒体膜电位(ΔΨm)的影响,探讨沙棘水提物对UVC辐射Ha Ca T细胞是否具有防护功能及其作用机制。方法:体外培养Ha Ca T细胞株,设置对照组(不加药、不照射)、UVC组和药物组(UVC辐射+不同浓度的沙棘水提物),CCK-8法测定细胞增殖、Annexin V/PI流式细胞术检测细胞凋亡、JC-1检测ΔΨm。结果:与UVC组比较,药物组CCK-8吸光度值(OD值)明显升高(P<0.01),且呈剂量依赖;细胞凋亡率降低,发生线粒体膜电位下降的细胞数比例(F值)下降。结论:沙棘水提物能够抑制Ha Ca T细胞凋亡、促进细胞增殖,其机制可能与保护线粒体功能有关。
