Bioaccumulation of 60Co2+ ions in tobacco plants

Tobacco has previously been used in investigations of metals and radionuclide uptake. This study presents determination of bioaccumulation and translocation of 60Co2+ ions in tobacco plants (Nicotiana tabacum L.) grown in Hoagland’s nutrient solution. Cobalt concentration in tobacco plants increased with increasing concentration in nutrient solution. Bioaccumulation from the initial concentration C0 = 0.96 μM Co reached 90% after 7 day cultivation. Only small amounts of Co accumulated in roots, up to 2 - 4 % were removable from roots by washing with 0.1 M CoCl2, indicating that this portion of Co is bound to the root surface in ion-exchangeable form. Tobacco roots retained approximately 2/3 of accumulated cobalt and 1/3 was transported to shoots. Autoradiography revealed that 60Co was preferentially localized in younger leaves. Prolongation of cultivation time did not change the [Co]roots : [Co]shoots ratio significantly. Relationships between growth rate, transpiration rate, uptake and distribution of cobalt in plant tissue are discussed.

Dentin tubule occlusion by a 38% silver diamine fluoride gel: an in vitro investigation

Objective Silver diamine fluoride (SDF) is effective in treatment of dentin hypersensitivity and caries lesions. However, the non-viscous solution does not easily allow clinicians to control the application area. A 38% SDF experiment gel was compared in vitro to commercial SDF for its ability to penetrate and occlude dentinal tubules. Materials and methods Human root surface dentin specimens were treated with gelled or standard 38% SDF or negative control. Penetration behavior was established by Drop Shape Analysis. Precipitates at the surface and within tubules were analyzed by SEM and EDX after treatment; Results: penetration depths up to 500 µm were observed for both SDF formulations. Both formulations occluded dentinal tubules similarly. Precipitates on the dentin surface and within dentinal tubules were found for both SDF formulations, with a slight tendency for the experimental gel SDF product to be more abundant than the commercially available one. Discussion: behavior of the experimental 38% SDF gel formulation appeared indistinguishable from the commercial 38% SDF product with respect to dentinal tubule penetration and occlusion. Conclusions The experimental 38% SDF gel may be a suitable intervention for the prevention of dentin hypersensitivity.

Effect of Root Surface Biomodification on Multiple Recession Coverage with Modified Coronally Advanced Tunnel Technique and Subepithelial Connective Tissue Graft: A Retrospective Analysis

To improve treatment efficacy of gingival recessions (GR), chemical preparation of the exposed root surface was advocated. The aim of this study was to compare the additional influence of root biomodifications with 24% ethylenediaminetetraacetic acid (EDTA) alone or with enamel matrix derivative (EMD) on the 12 month outcomes of modified coronally advanced tunnel (MCAT) with subepithelial connective tissue graft in the treatment of multiple GR. Average root coverage (ARC), complete root coverage (CRC), reduction in GR, reduction in recession width (RW), gain in clinical attachment level (CAL), increase in gingival thickness (GT), increase in keratinized tissue width (KTW) and changes in root coverage esthetic score (RES) were evaluated. A total of 60 patients with 215 GR were enrolled. In 70, GR root surfaces were treated with EDTA + EMD, in other 72, with EDTA, while in the remaining 73 saline solution was applied. ARC was 94%, 89%, and 91% in the EDTA + EMD, the EDTA and the saline groups, respectively (p = 0.8871). Gains in clinical attachment level (CAL; 2.1 ± 1.1 mm) and RES values (9.6 ± 0.9) were significantly higher in the EDTA + EMD group, when compared with two other groups. The differences between other preoperative and postoperative parameters showed statistical significance only within but not between groups. MCAT outcomes may benefit from adjunctive use of EDTA + EMD regarding 12 month CAL gain and professionally assessed esthetics using RES following treatment of GR.

Diagnosis and detection of VicK gene in Streptococcus mutans isolated from the saliva of patients with diabetic type 2 with tooth decay in the Iraqi population

Type 2 diabetes mellitus (T2DM) is gradually becoming more common in Iraq. Salivary changes and proliferation of specific bacterial communities cause oral disease that can adversely affect systemic conditions such as diabetes. Fifty saliva samples were collected from people with T2DM suffering from tooth decay and twenty-five people without T2DM suffering from tooth decay. The periodontal status, the extent of the root surface, and coronal caries were evaluated. Saliva was cultured for investigating Streptococcus mutans. The results showed that patients with type 2 diabetes had significantly more severe Periodontitis and a higher prevalence and magnitude of bacterial caries. Diabetic subjects had higher levels of Hemoglobin A1c (HbA1c) and Random Blood Sugar (R.B.S.). The S. mutans diagnosis by PCR for Sanger Sequencing technique by using VicK gene sequences (1300bp). The PCR products of the isolate were submitted to Macrogen Company for sequencing. Selected seven isolates as new isolates registered in global gene bank as locally S. Mutans isolates in Bagdad city/Iraq and their accepted accession numbers include LOCUS MT603520, MT603521, MT603522, MT603523, MT603524, MT603525,and MT603526 of nucleotide sequence. The VicK genes isolates' phylogenetic trees revealed a genotype that was closely connected to other isolates in GenBank. Furthermore, gene sequencing demonstrated a success rate of 99 percent. resemblance to other isolates in the GenBank database The likelihood of a link between S. Mutans and dental carries was determined by these findings.

Isolation and Screening of Quorum Quenching Rhizobacterial Isolates from the Experimental Farms of Gandhi krishi vigyana Kendra, Bengaluru, Karnataka, India

A group of synergistic bacteria that nestles on the root surface and provide a benefitting response to the plants are the rhizobacteria. The rhizobacteria benefit the plants by promoting growth and acts as biocontrol agents. Antibiosis, competition, synthesis of cell wall degrading enzymes, and eliciting induced systemic resistance are the mechanisms of biocontrol exhibited by rhizobacteria. Quorum quenching (QQ) is a new mechanism of biocontrol of pathogens whose virulence is induced by population density dependant chemical signaling. Efficient quorum quenching rhizobacteria isolated from the crop rhizospheres can be used as potential inoculums to control phytopathogens. Soft rot is one pernicious plant and storage disease affecting almost all vegetable crops. Hence, the present study was conducted to isolate rhizobacteria from the rhizospheres of six crops Rice (Oryza sativa), Maize (Zea mays), Finger millet (Eleusine coracana), Dolichos Bean (Lablab purpureus), Amaranthus (Amaranthus viridis), Field bean (Vicia faba) from the environs of GKVK. A total number of 96 rhizobacterial cultures were isolated from experimental fields of GKVK. The isolated cultures were screened for their quorum quenching ability by soft agar overlay assay and twenty-four out of ninety-six cultures were affirmative quorum quenchers. Proportionately, 25% of the total rhizobacterial isolates were quorum quenchers. The isolates were characterized morphologically and biochemically and a discussion of the obtained results are deliberately discussed.

On the Below- and Aboveground Phenology in Deciduous Trees: Observing the Fine-Root Lifespan, Turnover Rate, and Phenology of Fagus sylvatica L., Quercus robur L., and Betula pendula Roth for Two Growing Seasons

We tested the relation between the below- and aboveground tree phenology, determining if beech and oak have a greater fine-root lifespan and a smaller turnover rate than birch and if thinner fine-roots or fine-roots born in spring have a shorter lifespan and greater turnover rate than thicker fine-roots or fine-roots born in another season. The fine-root phenology, bud burst, and leaf senescence in Belgian stands were monitored using minirhizotrons, visual observations, and chlorophyll measurements, respectively. The fine-root phenology and the lifespan and turnover rate were estimated using generalized additive models and Kaplan–Meier analyses, respectively. Unlike the aboveground phenology, the belowground phenology did not show a clear and repeating yearly pattern. The cumulative root surface remained stable for birch but peaked for beech and oak around summer to autumn in 2019 and spring in 2020. The new root count was larger in 2019 than in 2020. The mean lifespan of fine-roots with a diameter below 0.5 mm (308 to 399 days) was shorter than those with a diameter between 0.5 to 1 mm (438 to 502 days), 1 to 2 mm (409 to 446 days), or above 2 mm (418 to 471 days). Fine-roots born in different seasons showed a species-specific lifespan and turnover rate.