scholarly journals In Vitro Lead Tolerance Testing in White Poplar Genotypes on Acidic Medium

2020 ◽  
Vol 11 (2) ◽  
pp. 153-160
Author(s):  
Branislav Kovačević ◽  
Gordana Tišma ◽  
Nataša Nikolić ◽  
Marina Milović ◽  
Vanja Vuksanović ◽  
...  
Keyword(s):  
Citric Acid ◽  
Chlorophyll A ◽  
Acidic Medium ◽  
Photosynthetic Parameters ◽  
White Poplar ◽  
Shoot Height ◽  
M 10 ◽  
Lead Tolerance ◽  
Tolerance Indices

This study evaluates in vitro tolerance of white poplar genotypes to the presence of lead in an acidic rooting medium. Lead was supplemented in form of Pb(NO3)2, in the following concentrations: 0 M (Control), 10-6 M, 10-5 M, 10-4 M and 10-3 M. After four weeks of cultivation, the following characters were measured: number of roots, the length of the longest root, the shoot height, dry root mass and dry shoot mass, and parameters related to photosynthetic pigments: content of chlorophyll a, b, a+b, and of carotenoids in fresh mass, as well as chlorophyll a/b ratio. For further statistical analysis, tolerance indices by Turner and Marshal (TI) were calculated for each measured character. The strongest inhibitory effect was achieved on the medium with 10-4 M Pb(NO3)2, but the best differentiation between genotypes was achieved on the medium with 10-5 M Pb(NO3)2. The highest tolerance indices for the length of the longest root and shoot height had genotypes L-12 and LBM, and for root and shoot dry mass genotypes LCM and L-12. There were no significant differences between genotypes in tolerance indices by any of the examined photosynthetic parameters. The obtained results suggest that both low pH and the presence of citric acid as chelating agent improved evaluation of lead tolerance in comparison with the results obtained on media with standard pH and without citric acid in similar studies. In vitro tests on acidic medium with citric acid can efficiently differentiate examined genotypes for lead tolerance, which could be important for their use in phytoextraction projects, especially on acidic soils.

scholarly journals The effect of low initial medium pH on in vitro white poplar growth

2013 ◽  
pp. 67-80
Author(s):  
Branislav Kovacevic ◽  
Dragana Miladinovic ◽  
Marina Katanic ◽  
Zoran Tomovic ◽  
Sasa Pekec
Keyword(s):  
Biomass Accumulation ◽  
Dry Mass ◽  
White Poplar ◽  
Medium Ph ◽  
Shoot Height ◽  
Initial Ph ◽  
The Media ◽  
Initial Medium ◽  
Shoot Mass

The effect of low initial medium pH on shoot and root development of five white poplar (Populus alba L.) genotypes was tested. The shoot height, fresh mass of shoots per jar, dry mass of shoots per jar, number of roots, as well as the length of the longest root were measured and final pH of the media determined, after 35 days of culture in vitro. Three initial pH values of the medium were tested: 3.0, 4.0 and 5.5 as control. Agar solidification at pH 3.0 was not achieved after sterilization in autoclave, but it was successful after sterilizing in a microwave oven. The obtained results indicate that the tested genotypes are able to significantly influence the changes of media pH during culture. The effect of differences among the examined media was significant for biomass accumulation and final media pH. Generally, significantly higher values of fresh and dry shoot mass, shoot height and the longest root length were recorded on a medium with initial pH 3.0 then on a standard medium with pH 5.5.The implications of the obtained results for the improvement of in vitro propagation of white poplars are discussed.

scholarly journals Lead Tolerance and Accumulation in White Poplar Cultivated In Vitro

2013 ◽  
Vol 4 (1) ◽  
pp. 3-12 ◽  
Author(s):  
Branislav Kovačević ◽  
Dragana Miladinović ◽  
Saša Orlović ◽  
Marina Katanić ◽  
Marko Kebert ◽  
...  
Keyword(s):  
White Poplar ◽  
Lead Tolerance

scholarly journals In-Vitro Silanization of Dental Enamel to Prevent Demineralization

2021 ◽  
pp. 353-363
Author(s):  
José R. Gutiérrez-Camacho ◽  
Luis Alejandro Aguilera-Galavíz ◽  
G. Sánchez-Balderas ◽  
Gabriela Palestino ◽  
Norma Verónica Zavala-Alonso ◽  
...  
Keyword(s):  
Citric Acid ◽  
Acidic Medium ◽  
Tooth Enamel ◽  
Dental Enamel ◽  
Hydrophobic Modification ◽  
Dental Tissues ◽  
Before And After ◽  
Topical Fluoride ◽  
Scanning Electron

Introduction. Caries is a multifactorial disease that can negatively affect dental tissues through the demineralization process, which produces acids deriving from the metabolism of carbohydrates. Some strategies to prevent this process have been proposed, such as topical fluoride application, resin-based restorations, pit and fissures sealers, infiltrated resins, vaccines, mouthwashes, and several brushing techniques. Objective. To evaluate in vitro enamel hydrophobic modification as a method of prevention against demineralization. Materials and Methods. A descriptive and comparative study was carried out. Thirty premolars extracted for orthodontic reasons were obtained, encapsulated in epoxy resin, sectioned, and sanded to obtain specimens 3mm in thickness. The samples were pretreated with NaOCl and EDTA, incubated with 1 and 4% octadeyltrichlorosilane (OTS) or with 3 and 6% octadecyltriethoxysilane (TEOS) for 5min and for 8h. Subsequently, the samples were immersed in citric acid for 2 months. The samples were analyzed by their contact angle, infrared spectroscopy, scanning electron microscopy, atomic and confocal force, before and after treatment in citric acid. Results. The samples coated with 1 and 4% OTS for 5min and 8h kept the silanizing agent on their surface after 2 months in citric acid. The treatment with TEOS was only effective at 6% with a reaction time of 5min. Conclusions. The modification with 1 and 4% OTS protects the surface of the tooth enamel from demineralization in acidic medium. The results indicate that treatment with 4% OTS is effective from 5min, which makes it appropriate in clinical practice.

scholarly journals Development and In Vitro-In Vivo Evaluation of a Novel Sustained-Release Loxoprofen Pellet with Double Coating Layer

Pharmaceutics ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 260 ◽  
Author(s):  
Dongwei Wan ◽  
Min Zhao ◽  
Jingjing Zhang ◽  
Libiao Luan
Keyword(s):  
Citric Acid ◽  
Drug Release ◽  
Sustained Release ◽  
Release Rate ◽  
Diffusion Rate ◽  
Immediate Release ◽  
Pharmacokinetic Studies ◽  
Release Tablet

This study aimed to develop a novel sustained release pellet of loxoprofen sodium (LXP) by coating a dissolution-rate controlling sub-layer containing hydroxypropyl methyl cellulose (HPMC) and citric acid, and a second diffusion-rate controlling layer containing aqueous dispersion of ethyl cellulose (ADEC) on the surface of a LXP conventional pellet, and to compare its performance in vivo with an immediate release tablet (Loxinon®). A three-level, three-factor Box-Behnken design and the response surface model (RSM) were used to investigate and optimize the effects of the citric acid content in the sub-layer, the sub-layer coating level, and the outer ADEC coating level on the in vitro release profiles of LXP sustained release pellets. The pharmacokinetic studies of the optimal sustained release pellets were performed in fasted beagle dogs using an immediate release tablet as a reference. The results illustrated that both the citric acid (CA) and ADEC as the dissolution- and diffusion-rate controlling materials significantly decreased the drug release rate. The optimal formulation showed a pH-independent drug release in media at pH above 4.5 and a slightly slow release in acid medium. The pharmacokinetic studies revealed that a more stable and prolonged plasma drug concentration profile of the optimal pellets was achieved, with a relative bioavaibility of 87.16% compared with the conventional tablets. This article provided a novel concept of two-step control of the release rate of LXP, which showed a sustained release both in vitro and in vivo.

scholarly journals Effect of Citric Acid on Color Changes of Calcium Silicate-Based Cements an In Vitro Study

2021 ◽  
Vol 11 (5) ◽  
pp. 2339
Author(s):  
Joanna Metlerska ◽  
Till Dammaschke ◽  
Mariusz Lipski ◽  
Irini Fagogeni ◽  
Anna Machoy-Mokrzyńska ◽  
...  
Keyword(s):  
Citric Acid ◽  
Calcium Silicate ◽  
In Vitro Study ◽  
Vitro Study ◽  
Color Measurement ◽  
Color Changes ◽  
Naked Eye ◽  
Root Canal Irrigants ◽  
The Difference

The aim of the present in vitro study was to investigate the effects of 10% and 40% citric acid (CA) on the color of calcium silicate–based cements (CSCs) in comparison to the effects of common root canal irrigants. Samples of six CSCs (n = 6)—ProRoot MTA (Dentsply, Tulsa, OK, USA), Biodentine (Septodont, Saint-Maur-des-Fossés, France), MTA Plus (Avalon Biomed Inc, by Prevest Denpro Limited, Jammu, India), MTA Repair HP (Angelus, Londrina, PR, Brazil), Ortho MTA (BioMTA, Seoul, Korea), and Retro MTA (BioMTA, Seoul, Korea)—were immersed in 10% and 40% CA as well as 15% EDTA, 2% NaOCl, 2% CHX, and 0.9% NaCl for 15 min, 1 h, and 24 h. ΔE values, representing the difference between the final and baseline values of the color components, were then determined using a VITA Easyshade Compact 5.0 spectrophotometer. Naked-eye evaluation of the changes in color and structures of the materials was performed using our own scale. Upon immersion of the materials in both 10% and 40% CA, there were statistically significant differences between spectrophotometric color measurement results for all CSCs (P < 0.05). However, CA does not cause dark discoloration, observable with the naked eye, of any of the materials, such as NaOCl and CHX. Significant statistical differences were also found between all CSCs in terms of submersion duration (P < 0.05). CA, which could be an alternative to EDTA use, caused greater CSCs discoloration and changed some of their structures. Unless required by the therapeutic procedure, clinicians should pay attention to the fact that the irrigant may affect the CSCs discoloration and minimize the contact time of irrigant with CSCs.

scholarly journals Crude Citric Acid of Trichoderma asperellum: Tomato Growth Promotor and Suppressor of Fusarium oxysporum f. sp. lycopersici

Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 222
Author(s):  
Abdulaziz A. Al-Askar ◽  
WesamEldin I. A. Saber ◽  
Khalid M. Ghoneem ◽  
Elsayed E. Hafez ◽  
Amira A. Ibrahim
Keyword(s):  
Citric Acid ◽  
Plant Growth ◽  
Organic Acid ◽  
Wilt Disease ◽  
Growth And Yield ◽  
Total Phenolic ◽  
Growth Promoters ◽  
Chlorophyll Pigments

Presently, the bioprocessing of agricultural residues to various bioactive compounds is of great concern, with the potential to be used as plant growth promoters and as a reductive of various diseases. Lycopersiconesculentum, one of the most consumed crops in the human diet, is attacked by Fusarium wilt disease, so the main aim is to biocontrol the pathogen. Several fungal species were isolated from decayed maize stover (MS). Trichodermaasperellum was chosen based on its organic acid productivity and was molecularly identified (GenBank accession number is MW195019). Citric acid (CA) was the major detected organic acid by HPLC. In vitro, CA of T.asperellum at 75% completely repressed the growth of Fusariumoxysporum f. sp. lycopersici (FOL). In vivo, soaking tomato seeds in CA enhanced the seed germination and vigor index. T. asperellum and/or its CA suppressed the wilt disease caused by FOL compared to control. There was a proportional increment of plant growth and yield, as well as improvements in the biochemical parameters (chlorophyll pigments, total phenolic contents and peroxidase, and polyphenol oxidase activities), suggesting targeting both the bioconversion of MS into CA and biological control of FOL.

Modified Technique for Measuring Platelet Aggregation

1997 ◽  
Vol 3 (3) ◽  
pp. 196-202 ◽  
Author(s):  
Alexander Kaplan ◽  
Svetlana Kaplan ◽  
Karen F. Marcoe ◽  
Lester R. Sauvage ◽  
William P. Hammond
Keyword(s):  
Platelet Aggregation ◽  
Citric Acid ◽  
Platelet Rich Plasma ◽  
Antiplatelet Agents ◽  
Current Approach ◽  
Molar Ratio ◽  
Maximum Height ◽  
Modified Technique ◽  
Aggregation Pattern

The turbidimetric method of Bom is the current approach for assessing the aggregation behavior of platelets. It has been of modest practical value, due to difficulty in standardizing laboratory techniques for plasma preparation and inadequate quantification of the aggregation process. We report a new technique of sedimented platelet rich plasma (SPRP) preparation that reduces the irregularities caused by factors associated with procuring and preparing blood samples and permits a more flexible protocol for laboratory practice. We quantified results with a platelet aggregation score, which is calculated by multiplying the ratio of the height of the initial wave of aggregation to the maximum height of the aggregation pattern by the total area under the aggregation curve and by the ratio of the whole blood platelet count and the number of platelets in the sample. Comparative analysis of platelet aggregation scores (n = 95) obtained with both plasma preparation techniques using a paired t test demonstrated no statistical differences ( t = 1.368, p = 0.174). To demonstrate the application of this modified method to evaluation of antiplatelet agents, the effects of aspirin and aspirin combined with citric acid on platelet aggregation were studied in vitro. The antiaggregatory effect of aspirin combined with citric acid was dependent on the pH and on their molar ratio, and was greater than the effect of aspirin alone. The SPRP protocol with platelet aggregation scoring methodology could be a valid alternative for measurement of the platelets' propensity to aggregate and the effect of antithrombotic treatments. Key Words: Platelet aggregation— Aspirin—Citric acid.

In Vitro Effects of Citric Acid Application Techniques on Dentin Surfaces

1992 ◽  
Vol 63 (11) ◽  
pp. 883-889 ◽  
Author(s):  
C. Rosa Wen ◽  
Raul G. Caffesse ◽  
Edith C. Morrison ◽  
Carlos E. Nasjleti ◽  
Udayan K. Parikh
Keyword(s):  
Citric Acid ◽  
Application Techniques ◽  
In Vitro Effects

scholarly journals The Epiphytic FernElaphoglossum luridum(Fée) Christ. (Dryopteridaceae) from Central and South America: Morphological and Physiological Responses to Water Stress

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Bruno Degaspari Minardi ◽  
Ana Paula Lorenzen Voytena ◽  
Marisa Santos ◽  
Áurea Maria Randi
Keyword(s):  
Water Stress ◽  
Water Deficit ◽  
Chlorophyll A ◽  
Tca Cycle ◽  
Photosynthetic Parameters ◽  
Relative Water ◽  
Physiological Studies ◽  
Cycle Regulation ◽  
Epiphytic Fern ◽  
Chlorophyll A Content

Elaphoglossum luridum(Fée) Christ. (Dryopteridaceae) is an epiphytic fern of the Atlantic Forest (Brazil). Anatomical and physiological studies were conducted to understand how this plant responds to water stress. TheE. luridumfrond is coriaceus and succulent, presenting trichomes, relatively thick cuticle, and sinuous cell walls in both abaxial and adaxial epidermis. Three treatments were analyzed: control, water deficit, and abscisic acid (ABA). Physiological studies were conducted through analysis of relative water content (RWC), photosynthetic pigments, chlorophyll a fluorescence, and malate content. No changes in RWC were observed among treatments; however, significant decreases in chlorophyll a content and photosynthetic parameters, including optimal irradiance (Iopt) and maximum electron transport rate (ETRmax), were determined by rapid light curves (RLC). No evidence of crassulacean acid metabolism (CAM) pathway was observed inE. luridumin response to either water deficit or exogenous application of ABA. On the other hand, malate content decreased in theE. luridumfrond after ABA treatment, seeming to downregulate malate metabolism at night, possibly through tricarboxylic acid (TCA) cycle regulation.

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