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Effect of Titanium Dioxide Nanoparticles on Growth and Biomass Accumulation in Lettuce (Lactuca sativa)

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American Journal of Plant Sciences 2024年第1期15卷 1-13页

作者： Channa B. rajashekar Brenden Armstrong Department of Horticulture and Natural Resources Kansas State University Manhattan KS USA

The use of titanium dioxide nanoparticles (nTiO2) is gaining interest in agriculture because of their impact on many aspects of plant growth. The present study examines the effects of nTiO2 (5 nm and 10 nm) applied to seeds and the seedlings as a foliar application on various aspects of growth characteristics and biomass accumulation in lettuce (Lactuca sativa, cv. Grand Rapids). Application of 10 nm nTiO2 to seeds through imbibition resulted in a significant reduction in shoot biomass accumulation while 5 nm nTiO2 did not affect the biomass accumulation in lettuce. The application of 10 nm nTiO2 reduced the fresh shoot biomass accumulation by about 18% compared to the control plants. Other growth characteristics such as shoot dry biomass, root fresh and dry biomass, plant height, and leaf area were not affected by the application of both 5 nm and 10 nm nTiO2. In addition, foliar application of these nanoparticles to the lettuce seedlings did not have a significant effect on most of the growth parameters examined, and the increasing concentration ranging from 5 nm/L to 400 mg/L did not produce a consistent response in lettuce. Thus, nTiO2 application to lettuce seeds had a notable negative impact on shoot growth while foliar application did not have a significant effect on many plant growth characteristics. However, foliar applications produced some symptoms of toxicity to the foliage in the form of necrotic or chlorotic patches on the leaves, which were more pronounced with increasing concentrations of both 5 nm and 10 nm nTiO2. However, these symptoms were apparent at a concentration as low as 50 mg/L of nTiO2. Thus, foliar application of nTiO2 may not have a significant impact on many of the growth characteristics in lettuce, but it can result in foliar toxicity.

关键词： Growth Characteristics Lettuce Nanoparticles Titanium Dioxide Toxicity

Potential use of Clerodendrum capitatum extracts and its formulation for control of three major stored product beetles

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Food Quality and Safety 2019年第3期3卷 179-185页

作者： Jacobs Mobolade Adesina Anjanappa Raghavendra Yallappa rajashekar Thomas Inomisan Ofuya Department of Crop Soil and Pest Management TechnologyRufus Giwa PolytechnicOwoNigeria Insect Resources Laboratory Animal Resources ProgrammeInstitute of Bioresources and Sustainable DevelopmentDepartment of BiotechnologyGovernment of IndiaImphal Division of Insect Ecology National Bureau of Agricultural Insect ResourcesBangaloreIndia Department of Crop Soil and Pest ManagementFederal University of TechnologyAkureNigeria

Objective:Insecticidal activity of Clerodendrum capitatum extracts against the stored product insect pest,Sitophilus oryzae(L.),Rhyzopertha dominica(F.),and Tribolium castaneum(Herbst)were *** and Methods:Hundred grams of *** powder was sequentially extracted with a series of solvents of increasing polarity in a Soxhlet apparatus and the extracts were concentrated on rotary evaporator to make it solvent free and the residue dissolved in a known volume of methanol and the solution was assayed for insecticidal activity by the fumigant *** extract which showed maximum activity was selected for the preparation of herbal formulation and for its insecticidal properties and *** herbal formulation obtained from leaves of *** was investigated by GCMS and GC/***:Clerodendrum capitatum ethyl extract had a very strong repellent activity to adults of all three major stored grain insects and was significantly repellent at a 1.58 mg/cm^(2).The hexane extract(oil)had high fumigant activity with LC_(50) values in the range between 25 and 32μg/L.A total of 14 components representing 97.8%of the formulation were identified and the main compounds in the formulation were found to be 2-Heptanone,3-methyl(33.9%)and Hexahydrofarnesyl acetone(25.3%)followed by 3-Dodecen-1-al(10.2%)and 8-Methyl-1-undecene(4.9%).Further,herbal formulation was found to be highly toxic to mixed age cultures of all three major stored grain insect pests which recorded 80%-90%mortality at dose of 200μg/L in 24 h exposure,where as 100%mortality achieved at dose of 200μg/L in 72 h exposure,***:The results indicate that extracts and formulation of *** has the potential to be developed in to a natural insecticide or repellent for controlling of stored product beetles.

关键词： fumigation gas chromatography mass spectrometry(GCMS) herbal formulation repellence stored product beetles

Potential of edible insects as source of functional foods:biotechnological approaches for improving functionality

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Systems Microbiology and Biomanufacturing 2022年第3期2卷 461-472页

作者： Wahengbam Deepanita Devi Rajkumari Bonysana Kokho Kapesa Amit Kumar Rai Pulok Kumar Mukherjee Yallappa rajashekar Insect Bioresources Laboratory Animal Resources ProgrammeInstitute Bioresources and Sustainable Development(IBSD)Takyelpat Imphal WestManipur 795001India Institute of Bioresources and Sustainable Development Mizoram NodeAizwalMizoram 796001India

Consumption of insects as food has a long history and has been documented by many ***,it is extensively practiced in Africa,Asia,Australia,and Latin America as traditional food providing nutritional,economic and ecological benefit for rural *** today’s world,edible insects are limelight by many researchers and industrialist due to the presence of enormous nutrient potential as well as bioactive *** review mainly focuses on the potential of edible insect for its diverse nutraceutical properties,production and processing as a functional food and its acceptance and boost in the market trends in global *** consumption of edible insects is purely based on ethnic traditional knowledge of the local *** studies on edible insects have shown their potential as source of nutraceuticals with promote health benefit and can be an alternative source of *** of the edible insects are rich source of protein,energy,vitamins,essential fatty acids and *** these insects can be a source of bioactive compounds especially peptides,which can be applied in functional food *** many countries,the traditional knowledge of entomophagy is being applied for production of value-added products using modern technology.

关键词： Edible insects Functional foods Nutrition Biotechnology approaches

Dual Role of Plant Phenolic Compounds as Antioxidants and Prooxidants

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American Journal of Plant Sciences 2023年第1期14卷 15-28页

作者： Channa B. rajashekar Department of Horticulture and Natural Resources Kansas State University Manhattan USA

Natural phenolic compounds are secondary metabolites found in a wide range of plants including food crops. As many of them are known to be antioxidants and can prevent several chronic and degenerative diseases in humans, they are a part of a healthy diet. However, these antioxidants can act as prooxidants under high phenolic concentration, high pH, or in the presence of transition metal ions such as Cu2+ or Fe3+, producing reactive oxygen species (ROS) including hydroxyl radicals resulting in oxidative stress and cell toxicity. While this can lead to pathogenesis including the development of various types of cancers, elevated levels of ROS are beneficial to kill malignant cells and foodborne pathogens to improve food safety. Thus, the dual nature of phenolic compounds allows them to act as antioxidants and prooxidants. Similarly, depending on the level of prooxidant activity, ROS can induce either pathogenesis or serve as a potential agent to kill malignant cells and foodborne pathogens.

关键词： Anticancer Antimicrobial Antioxidants Food Safety Phenolic Compounds Prooxidants

Lesion-symptom mapping with NIHSS sub-scores in ischemic stroke patients

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Stroke & vascular Neurology 2022年第2期7卷 124-131页

作者： Deepthi rajashekar Matthias Wilms M Ethan MacDonald Serena Schimert Michael D Hill Andrew Demchuk Mayank Goyal Sean P Dukelow Nils Daniel Forkert Biomedical Engineering Graduate Program Hotchkiss Brain InstituteUniversity of CalgaryCalgaryAlbertaCanada Department of Radiology Cumming School of MedicineUniversity of CalgaryCalgaryAlbertaCanada Hotchkiss Brain Institute University of CalgaryCalgaryAlbertaCanada Department of Clinical Neurosciences University of CalgaryCalgaryAlbertaCanada Department of Electrical and Computer Engineering University of CalgaryCalgaryAlbertaCanada Department of Community Health Sciences Cumming School of MedicineUniversity of CalgaryCalgaryAlbertaCanada Department of Medicine Cumming School of MedicineUniversity of CalgaryCalgaryAlbertaCanada Alberta Children's Hospital Research Institute University of CalgaryCalgaryABCanada

Background Lesion-symptom mapping(LSM)is a statistical technique to investigate the population-specific relationship between structural integrity and post-stroke clinical *** clinical practice,patients are commonly evaluated using the National Institutes of Health Stroke Scale(NIHSS),an 11-domain clinical score to quantitate neurological deficits due to *** far,LSM studies have mostly used the total NIHSS score for analysis,which might not uncover subtle structure–function relationships associated with the specific sub-domains of the NIHSS ***,the aim of this work was to investigate the feasibility to perform LSM analyses with sub-score information to reveal category-specific structure–function relationships that a total score may not *** Employing a multivariate technique,LSM analyses were conducted using a sample of 180 patients with NIHSS assessment at 48-hour post-stroke from the ESCAPE *** NIHSS domains were grouped into six categories using two *** was conducted for each category of the two groupings and the total NIHSS *** Sub-score LSMs not only identify most of the brain regions that are identified as critical by the total NIHSS score but also reveal additional brain regions critical to each function category of the NIHSS assessment without requiring extensive,specialised *** These findings show that widely available sub-scores of clinical outcome assessments can be used to investigate more specific structure–function relationships,which may improve predictive modelling of stroke outcomes in the context of modern clinical stroke assessments and neuroimaging.

关键词： patients score category

Flame-retardant properties of in situ sol-gel synthesized inorganic borosilicate/silicate polymer scaffold matrix comprising ionic liquid

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Frontiers in Energy 2019年第1期13卷 163-171页

作者： Kumar Sai SMARAN rajashekar BADAM Raman vEDARAJAN Noriyoshi MATSUMI School of Materials Science Japan Advanced Institute of Science and Technology1-1 AsahidaiNomiIshikawa 923-1292Japan Division of Chemistry Graduate School of Humanities and SciencesOchanomizu University2-1-1OhtsukaBunkyo-kuTokyo 112-8610Japan School of Materials Science Japan Advanced Institute of Science and Technology1-1 AsahidaiNomi.Ishikawa 923-1292Japan Surface Science Laboratory Toyota Technological Institute2-12-1 HisakataTempaku Nagoya 468-8511Japan Centre for Fuel Cell Technology International Advanced Research Center for Powder Metallurgy and New MaterialsChennaiIndia

This paper focuses on the superiority of organic?inorganic hybrid ion-gel electrolytes for lithiumion batteries(LiBs)over commercial electrolytes,such as 1 M LiPF6 in 1:1 ethylene carbonate(EC):dimethyl carbonate{DMC){1 M LiPF6-EC:DMC},in terms of their flame *** ion-gel electrolytes possess ionic liquid monomers,which are confined within the borosilicate or silicate matrices that are ideal for *** flame tests confirm that the organicinorganic hybrid electrolytes are less susceptible to flames,and these electrolytes do not suffer from a major loss in terms of *** addition,the hybrids are ***,these hybrids are only oxidized when subjected to a flame unlike other commercial electrolytes used in lithium-ion *** analyses using differential scanning calorimetric studies reveal that the hybrids are glassy until the temperature reaches more than 100℃.The current results are consistent with previously published data on the organic-inorganic hybrids.

关键词： inorganic polymeric borosilicate network organic-inorganic hybrids self-extinguishability non flammability lithium batteries flame-retardants

Grain Protection Potential of Decaleside II, a New Plant-Derived Natural Insecticide

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Advances in Entomology 2014年第3期2卷 144-150页

作者： Yallappa rajashekar Thimmappa Shivanandappa Department of Food Protectants and Infestation Control Central Food Technological Research Institute (Council of Scientific and Industrial Research) Mysore India

Decaleside II is the novel trisaccharide isolated from the edible roots of Decalepis hamiltonii that belong to a new class of natural insecticides. In the present study we have investigated grain protection potential and persistence activity of Decaleside II against stored-product pests such as Rhyzopertha dominica, Sitophilus oryzae, Tribolium castaneum and Callosobruchus chinensis. Decaleside II usually increased parental mortality and reduced F1 progeny in residual toxicity bioassays. At 7 days of the storage period of treated grains and pulses, the mortality was 100% of all four stored product insects. Both wheat and green gram treated with Decaleside II were totally free from infestation for the longer period of storage up to 210 d. Decaleside II being a natural trisaccharide, does not pose any toxic hazard from the treated grain and the lack of toxicity is attributed to the 1, 4 α linkage of the sugars which are easily hydrolyzed by the digestive enzymes such as glucosidases. Therefore, the insect selectivity and mammalian safety of Decaleside II make them highly suitable for use as novel grain protectants of natural origin.

关键词： Decaleside II Insecticidal Activity Grain Protectants Seed viability Mammalian Safety

Elevated CO<sub>2</sub>Levels Affect Phytochemicals and Nutritional Quality of Food Crops

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American Journal of Plant Sciences 2018年第2期9卷 150-162页

作者： C. B. rajashekar Department of Horticulture and Natural Resources Kansas State University Manhattan USA

Rising atmospheric CO2 levels pose many challenges to global climate, thus to all forms of life including plants. The impact of elevated CO2 on plant growth and development and the nutritional quality in relation to major nutrients in many crops has been explored extensively. However, information on the elevated CO2 effects on the health-promoting phytochemicals in food crops is rather limited. Major nutrients in food crops including protein, phosphorus, potassium, calcium, iron, zinc and other micronutrients in many food crops are known to be suppressed at elevated CO2 levels. Elevated CO2 increases carbohydrate accumulation but decreases nitrogen accumulation in plants thus affecting their C-N ratio. A number of studies show that high C-N ratio and nitrogen limiting conditions in plants can result in the accumulation of carbon-based secondary metabolites, many of which are health-promoting phytochemicals and allelochemicals involved in plants’ defense against pathogens and herbivory. Although the results from these studies are variable, it can be concluded that while elevated CO2 is known to suppress the content of major nutrients, it may actually have a favorable impact on the accumulation of carbon-based phytochemicals in food crops.

关键词： Elevated CO2 Food Crops Nutritional Quality Phytochemicals Secondary Metabolites

Elevated Carbon Dioxide Level Suppresses Nutritional Quality of Lettuce and Spinach

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American Journal of Plant Sciences 2016年第1期7卷 246-258页

作者： Anju Giri Brenden Armstrong Channa B. rajashekar Department of Horticulture Forestry and Recreational Resources Kansas State University Manhattan KS USA

Rising global CO2 levels are a major factor that impacts not only the environment but also many plant functions including growth, productivity and nutritional quality. The study examined the impact of elevated [CO2] on nutritional quality and growth characteristics of lettuce (Lactuca sativa) and spinach (Spinacia oleracea). Elevated [CO2] decreased the concentration of many important nutrients including nitrogen (protein), potassium and phosphorus in the edible parts of both lettuce and spinach. The nitrogen concentration in lettuce shoots was reduced by more than 30% at elevated [CO2] compared to the plants grown at ambient level of CO2. Similarly the concentration of a number of micronutrients including sulfur, zinc, copper and magnesium, was depressed in lettuce shoots. Although the total phenolic content and antioxidant capacity were higher in lettuce at elevated CO2, they were not affected in spinach. The photosynthetic activity was variable among the plant species while there was no increase in the carbon accumulation in these plants at elevated [CO2]. However, there was significant reduction in the leaf stomatal conductance in both lettuce and spinach in response to higher [CO2], which is likely affect both water loss from the leaves and their photosynthetic activity. The results indicate a broad adverse impact of rising [CO2] on the nutritional quality of commonly consumed leafy vegetables namely, lettuce and spinach.

关键词： Elevated Carbon Dioxide Lettuce Nutritional Quality Phytochemicals Protein Deficiency Spinach