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Herein, we report the fluoride anion sensing properties of a commercially available and inexpensive organic compound, isatin, which is found to be a highly selective and sensitive sensor. In naked-eye experiments, by addition of fluoride anions, isatin shows a dramatic color change from pale yellow to violet at room temperature, while the addition of other anions, i.e. Cl−,$\mathrm{Cl}^-,$Br−,I−,ClO4−,H2PO4−andPF6−,$\mathrm{Br}^-,\mathrm I^-,\mathrm{ClO}_4^-,{\mathrm H}_2\mathrm{PO}_4^-\,\mathrm{and}\,\mathrm{PF}_6^-,$did not induce any colour change. Additionally, recognition and titration studies have also been done through UV/Vis spectroscopy. Isatin displayed a new absorption band at 533 nm after the addition of fluoride anions, which is presumably due to acid-base interaction between isatin and fluoride anions, while other anions did not trigger noticeable spectral changes. The detection limit was observed to be 0.367 ppm. DFT calculations were also performed to further explain the behavior of receptor 1 towards the Fˉ anion. Owing to high sensitivity and selectivity, isatin can be useful in the detection of biologically or environmentally important fluoride anions at very low concentration.

In this paper, we will construct a few types of graphs based on the ideal-annihilator, right-ideal-annihilator, left-ideal-annihilator for a KU-algebras. We will also study some graph invariants, such as connectivity, regularity, and planarity for these graphs. [ABSTRACT FROM AUTHOR]

Salinity is a major abiotic environmental factor around the world that affects plant growth deleteriously. A pot experiment of purple variety of Solanum melongena L. (brinjal) was conducted during the growth season of 2021 with completely randomized block design. Different treatments of sodium fluoride (NaF) (300ppm and 400ppm) revealed that NaF showed harmful effects on plant height, shoot length and root length of brinjal. It also decreased no. of leaves, leaf area, and no. of branches along with yield parameters and biochemical attributes. Crop production can be improved by using nanotechnology under fluoride stress. The reduction in growth parameters caused by NaF can be ameliorated by treating the plants with different concentrations of zinc oxide nanoparticles (ZnONPs) (100ppm, 200ppm, 300ppm, 400ppm, and 500ppm) using soil drench and foliar spray methods. The ZnOPs were synthesized from java palm (Syzygium cumini L.) utilizing the green synthesis method. Exogenous application of ZnOPs enhanced growth parameters of brinjal plants under NaF stress. The upsurge level of chlorophyll a, chlorophyll b, total chlorophyll content, and carotenoids decline the toxic effect of NaF. The ZnOPs concentration at 500ppm increased biomass production at vegetative and reproductive stages. [ABSTRACT FROM AUTHOR]

The aim of the present study was to examine the effect of salicylic acid on the salinity tolerance of two varieties (RKS-510 and Classic) of pea (Pisum sativum L.). Sodium fluoride (NaF), in concentrations of 50, 100, 150, and 200 ppm, was applied, in a pot experiment during the growth season 2015-2016, to the plants as a soil drench on a biweekly basis to create a stressed condition by its gradual accumulation causing toxic effects on the biochemical processes of the plants. Salicylic acid, in concentrations of 100, 200, and 300 ppm, was also given exogenously to the fluoride-stressed plants as a foliar application to examine its effect on two anti-oxidative enzymes, ascorbate peroxidase and peroxidase. Control plants were treated with tap water. At 44 days after sowing (DAS), the activity of ascorbate peroxidase was lowest in the control plants for both cultivars (controls: 0.47 and 0.45 µmol/min/g fresh weight for RKS-510 and Classic, respectively) and increased with increasing concentrations of NaF (50 ppm: 0.57 and 0.54; 100 ppm: 0.76 and 0.72; 150 ppm: 0.85 and 0.82; 200 ppm: 0.93 and 0.90 µmol/min/g fresh weight for RKS-510 and Classic, respectively). Similarly, the activity of peroxidase was lowest in the control plants for both cultivars (controls: 0.27 and 0.25 units of enzyme activity g-1 fresh weight min-1 for RKS-510 and Classic, respectively) and increased with increasing concentrations of NaF (50 ppm: 0.35 and 0.32; 100 ppm: 0.38 and 0.35; 150 ppm: 0.44 and 0.43; 200 ppm: 0.49 and 0.47 units of enzyme activity g-1 fresh weight min-1 for RKS-510 and Classic, respectively). Compared to the NaFtreated group, the foliar application of the application of both salicylic acid (foliar application) and NaF (soil drench) lowered the fluoride-induced stress resulting in lower activity levels for ascorbate peroxidase and peroxidase. However, at higher concentrations, salicylic acid itself may cause a high level of stress in plants and was less effective. We concluded that the foliar application of salicylic acid has an ameliorative effect on the impaired salinity tolerance in the RKS-510 and Classic cultivars of Pisum sativum L. produced by sodium fluoride stress. [ABSTRACT FROM AUTHOR]

Fluoride is present naturally in the environment and may reach levels that impair the bio-physiological processes in plants. The aim of the present study was to examine the effect of sodium fluoride (NaF) stress on the yield of Solanum melongena L., (aubergine, brinjal, eggplant), a member of the Solanaceae family with edible properties. In a pot experiment, lasting from August to October 2017, NaF was applied twice weekly as a soil drench and a foliar spray in concentrations of 100, 200, 300, 400, 500, and 600 ppm. The yield of S. melongena was severely affected by the NaF in a doserelated manner with the maximum yield reduction observed at 600 ppm NaF. The soil drench affected the plants more than the foliar spray application. The results showed that S. melongena is a salt sensitive crop. [ABSTRACT FROM AUTHOR]

Fluoride is a naturally accruing element which harms our environment. Accumulation of excess fluoride in the environment poses a serious threat to plants. It causes various changes in the biophysiological processes of plants. The present study was conducted to determine the effect of NaF on Solanum melongena L. (brinjal, bengun, aubergine, eggplant). S. melongena belongs to the family Solanaceae and is an important edible plant. It was grown during the crop season (August-October, 2017) in pots. Different concentrations of NaF, i.e., 100, 200, 300, 400, 500, and 600 ppm, were applied, along with a control, as a soil drench and foliar spray twice a week. The parameters examined to determine the effect of the stress of NaF on the plant growth were the shoot and root length and the number and the area of the leaves. There was a dose-related reduction in growth with the NaF treatment. In general, the soil drench affected growth more than the foliar spray. The results show that Solanum melongena L. is a salt sensitive crop. [ABSTRACT FROM AUTHOR]

Fluoride in our physical environment causes several health hazards, not only to humans but to plants as well. Its high concentration in soil, water, and vegetation is a major problem for today's world. The present study was conducted to assess the impact of salicylic acid on the growth and biomass production of Pisum sativum L. grown under sodium fluoride (NaF) stress. Pisum sativum L. (pea) is an edible plant used to nourish humans as its seeds are rich in protein and carbohydrates. Two varieties of Pisum sativum, RKS-510 and Classic, were grown during the 2015-16 season with various concentrations of NaF, i.e., 50, 100, 150, and 200 ppm, being applied as a soil drench on a biweekly basis to create stress for the plants. The gradual accumulation of the fluoride ion caused toxic effects on the biochemical processes of the plants. A foliar application of 100, 200, and 300 ppm salicylic acid was also given exogenously to examine its effects on the plants under NaF stress. It was observed that the plant height and biomass production of both the varieties of pea plant decreased under NaF stress while this decline was overcome by the exogenous application of salicylic acid at the 100 and 200 ppm levels. One hundred and 200 ppm salicylic acid enhanced the growth of the plants while 300 ppm salicylic acid had a reducing effect similar to that of NaF. As salicylic acid at 100 and 200 ppm had ameliorative effects in on plants under NaF stress, we concluded that the foliar application of salicylic acid promotes salt tolerance in two different cultivars of Pisum sativum L. [ABSTRACT FROM AUTHOR]

In this paper, we define JU-algebras and discuss the concept of p- closure ideals of JU-algebras which we denote as Jpc for a non-empty subset J of a JU-algebra X. Moreover, we investigate related proper- ties of JU-algebras and p-closures of subsets of JU-algebras. Through p-closure of subsets of X we also define a closure operator. We estab- lish a relation between f(Jpc) and (f(J))pc for a JU-homomorphism f and prove that Jpc is the least closed p-ideal containing J for any ideal J of X. [ABSTRACT FROM AUTHOR]

In this study, an examination was made of the size, fresh weight, and dry weight of turnip, Brassica rapa L., at 70 days after sowing (DAS) when different concentrations of sodium fluoride (NaF) (0 [control], 50 [NaF-50], 100, 150, 200, and 300 [NaF-300] ppm) were applied. The size of the turnip was maximal in the control plants, 20.82 cm2. In the plants given NaF-50, as both a soil drench and as a foliar spray, the sizes were 16.32 cm2 and 18.08 cm2, respectively. The size of the turnip gradually decreased as the NaF stress was increased and was at a minimum with NaF-300 for both methods of application (soil drench: 2.47 cm², foliar spray 4.35 cm²). At 70 DAS, the fresh weight was greatest, 66.60 g, in the control plants, followed by 43.06 g, in the plants given NaF-50 by foliar spray. The fresh weight successively declined as the concentration of NaF increased and at NaF-300 and it reached a minimum for both the soil drench, 1.36 g, and the foliar spray, 2.43 g. The dry weight was recorded by oven drying the fresh turnip at 70 DAS, and found to be at a maximum in the control plants, 6.60 g. When a fluoride stress was applied with NaF-50, as a soil drench and a foliar spray, the dry weight decreased to 4.30 g and 5.06 g, respectively. As the concentration of NaF increased, the dry weights decreased in a manner similar to that found with the fresh weights and the lowest values were found with NaF-300 (soil drench: 0.556 g, foliar spray: 1.20 g). In conclusion, NaF applied as both a soil drench and a foliar spray, at concentrations of 50-300 ppm, reduced the size, fresh weight, and dry weight of turnip compared to a control group with 0 ppm NaF. The application of the NaF by soil drench caused a greater degree of stress to the turnip than did the application by foliar spray. [ABSTRACT FROM AUTHOR]

The production of crops in Pakistan is severely affected by the widely prevalent problem of salinity in the soil with salts including fluoride. The aim of the present study was to examine, in a pot experiment, the effects of sodium fluoride (NaF), applied as a foliar spray and as a soil drench, on the growth and other attributes of turnip (Brassica rapa L.). The percentage reduction in root length after treatment with a soil drench and a foliar spray was found to be at a maximum in plants treated with 300 ppm NaF, 62.6% and 51.02%, respectively, at 50 days after sowing (DAS) and 66.4% and 54.59%, respectively, at 70 DAS. The percentage reductions in the number of leaves, at 50 and 70 DAS, was 50.03% and 65.23%, respectively, for plants having an application of 300 ppm sodium fluoride by soil drench, while the corresponding reductions for the application of the 300 ppm NaF by foliar spray were 50.03% and 58.7%, respectively. At 50 DAS, the least percentage reduction in leaf area, 2.18%, occurred when the plants were given 50 ppm NaF by foliar spray and the highest value, 59.87%, was for the plants given 300 ppm NaF by soil drench. After 50 DAS, the percentage decrease in shoot fresh weight was found to be highest, 78.84%, when 300 ppm NaF was used as a soil drench, with the corresponding figure for the foliar spray application being 76.65%. Similarly, at 70 DAS, the percentage reduction in fresh shoot weight increased gradually with higher concentrations of NaF and was a maximum at 300 ppm NaF with both methods of application. We concluded that the application of NaF as a soil drench caused a greater reduction in the various parameters of turnip plant growth than did application as a foliar spray. [ABSTRACT FROM AUTHOR]

A representation of strictly convergent power series as Newton interpolating series is given. In the case of one indeterminate bounded Newton interpolating series are studied as a generalization of strictly convergent power series. A method for analytic p-adic continuation by means of bounded Newton interpolating series is presented. [ABSTRACT FROM AUTHOR]