番茄红素对臭氧致大鼠肺氧化损伤的拮抗作用(英文)

背景:臭氧是一种强氧化剂,在体内引发脂质过氧化反应,损伤机体抗氧化酶类,形成氧化损伤。肺是人体与外界进行气体交换的主要器官,直接与外界相通,最早受到臭氧的攻击而形成氧化损伤。番茄红素是一种重要的类胡罗卜素,具有多种生物学作用,如抗氧化,抗肿瘤,诱导细胞间隙连接通讯等。目的:探讨臭氧对大鼠造成的氧化损伤和番茄红素的保护作用。设计:随机对照的实验研究。单位:哈尔滨医科大学公共卫生学院卫生检验中心,黑龙江省疾病控制中心,哈尔滨医科大学附属第一医院检验科。材料:实验地点为哈尔滨医科大学公共卫生学院动物室。选用纯种雄性SD大鼠40只,由哈尔滨医科大学附属第二医院实验动物中心提供。干预:分为正常对照组、臭氧损伤模型组、番茄红素低剂量组(10mg/kg)和番茄红素高剂量组(20mg/kg)。除对照组外,其余各组大鼠吸入臭氧染毒,番茄红素组给予番茄红素,模型组和对照组不给番茄红素,3周后处死,取血清和肺组织并制备匀浆。主要观察指标:血清和肺匀浆中超氧化物歧化酶(superoxidedismutase,SOD)活性、谷胱甘肽过氧化物酶(glutathioneperoxiduse,GSH-Px)活力及丙二醛含量。结果:臭氧能够明显影响大鼠抗氧化酶活性,降低SOD活性血清犤(4645.60±891.85)μkat/L,肺(566.28±164.70)nkat/g〗。

Tomato detection method using domain adaptive learning for dense planting environments

This study aimed to address the challenge of accurately and reliably detecting tomatoes in dense planting environments,a critical prerequisite for the automation implementation of robotic harvesting.However,the heavy reliance on extensive manually annotated datasets for training deep learning models still poses significant limitations to their application in real-world agricultural production environments.To overcome these limitations,we employed domain adaptive learning approach combined with the YOLOv5 model to develop a novel tomato detection model called as TDA-YOLO(tomato detection domain adaptation).We designated the normal illumination scenes in dense planting environments as the source domain and utilized various other illumination scenes as the target domain.To construct bridge mechanism between source and target domains,neural preset for color style transfer is introduced to generate a pseudo-dataset,which served to deal with domain discrepancy.Furthermore,this study combines the semi-supervised learning method to enable the model to extract domain-invariant features more fully,and uses knowledge distillation to improve the model's ability to adapt to the target domain.Additionally,for purpose of promoting inference speed and low computational demand,the lightweight FasterNet network was integrated into the YOLOv5's C3 module,creating a modified C3_Faster module.The experimental results demonstrated that the proposed TDA-YOLO model significantly outperformed original YOLOv5s model,achieving a mAP(mean average precision)of 96.80%for tomato detection across diverse scenarios in dense planting environments,increasing by 7.19 percentage points;Compared with the latest YOLOv8 and YOLOv9,it is also 2.17 and 1.19 percentage points higher,respectively.The model's average detection time per image was an impressive 15 milliseconds,with a FLOPs(floating point operations per second)count of 13.8 G.After acceleration processing,the detection accuracy of the TDA-YOLO model on the Jetson Xavier NX development board is 90.95%,the mAP value is 91.35%,and the detection time of each image is 21 ms,which can still meet the requirements of real-time detection of tomatoes in dense planting environment.The experimental results show that the proposed TDA-YOLO model can accurately and quickly detect tomatoes in dense planting environment,and at the same time avoid the use of a large number of annotated data,which provides technical support for the development of automatic harvesting systems for tomatoes and other fruits.

Effects of Oyster Shell Soil Amendmenton Fruit Auality and Soil Chemical Properties in Greenhouse Tomato Acidic Soils

[Objective]The aim was to explore the feasibility of applying oyster shell soil amendment for tomato production in order to determine proper quantity of the soil conditional.[Method]Field tests were performed to research effects of the soil conditioner on tomato yield,quality and soil p H.[Result]The results showed that tomato yield increased in the treatment groups with oyster shell soil amendment.The group SC50 increased the most by 16.5%than the control group.Based on normal fertilization,tomato growth was promoted by the soil amendment,and per tomato weight and lycopene content both improved during peak-fruiting period.Besides,soil p H value was enhanced by the soil amendment also.[Conclusion]It can be concluded that the effect was the best when soil conditioner was applied at 750 kg/hm2.

Effect of the Chemical Mutagens Sodium Azide on Plant Regeneration of Two Tomato Cultivars under Salinity Stress Condition in vitro

The study was carried out to induce variations and stimulate callus induction, plant regeneration from different explants of two tomato （Lycopersicon esculentum Mill.） cultivars Trescantos and super Regina by using tissue culture technique and Sodium azide as a chemical mutagens at concentrations （0.0, 2.0 and 4.0） mM under salinity stress condition at the levels（3.0, 6.0 and 9.0） dS/m. Different plant growth regulators were tested for their potentials in callus induction. The results revealed that treated seeds with SA （sodium azide） at concentration （2.0） mM increased seed germination percentage, seedling height and root length as compare to control treatment. While （4.0） mM concentration cause a reduction in all parameters mentioned above. Concerning to callus induction both cultivars showed a different response against different tested media with varying concentrations of plant growth regulators and despite their variable response to all tested media a combination of （2.0） mg from Kinetin （KIN） and lndol acetic acid （IAA） was found to be the most effective as compare to other treatments. Moreover, when callus transferred to a stressed media the variation was observed in explants fresh weight, and high reduction with the increment of salt level were recorded. Similarly the regeneration efficiency from stressed callus were observed at the level 3.0 and 6.0 dS/m while 9.0 dS/m the callus failed to regenerate plants for all three explants of both tomato cultivars.

Kinetic Study of Color Changes of Tomato Purees with Microwave and Conventional Drying

Kinetics of color change in tomato purees dried using microwave and conventional method were investigated. For this purpose, the color parameters of Hunter L,a,b and browning index （A42o）, and estimated values of chroma, hue angle, AE, Hunter a/b and a ~ b were examined. The changes in color of tomato samples followed both zero and first order kinetic models to describe visual color changes, and ＆E parameters followed first order kinetic. It was concluded that Hunter axb parameters can be used adequately to follow up the color change of tomato samples during the drying.

Use of Spent Mushroom Substrate as Growing Media for Tomato and Cucumber Seedlings

The aim of this research was to evaluate weathered spent mushroom substrate （SMS）, made from spent Flammulina velutipes mushroom substrate, as a growing medium for nursery seedlings. Two vegetable species, cucumber （Cucumis sativus L. cv. Jinchun No. 2） and tomato （Solanurn lycopersicum L. cv. Mandy）, were grown in 8 media of SMS in various ratios with perlite or vermiculite. A mixed substrate of peat with perlite （1：1; v：v） was used as the control （CK）. The experiment was arranged in a completely randomized design under greenhouse conditions. Prior to sowing, some physical and chemical properties of the growing media were determined. Results showed that all the mixtures had desirable physical and chemical properties for their use in nursery tomato and cucumber seedlings except for the T4 （SMS：vermiculite = 1：1; v：v） and the T8 （SMS：perlite = 2：1; v：v） mixtures. Compared with the CK, increased plant height, leaf area, fresh weight, dry weight and index of seedling quality were found in the T3 （SMS：vermiculite = 2：1; v：v） and T6 （SMS：perlite = 4：1; v：v） growing media. SMS should be considered as an alternative for the widely used but expensive and resource-limited peat in greenhouse cultivation.