جستجوی مقالات مرتبط با کلیدواژه "بور" در نشریات گروه "پزشکی"

 Noninvasive treatments are preferred for tooth enamel remineralization, and metal nanocomposites could be used for this purpose. The present study investigated the effect of boron nanocomposites doped on the hydroxyapatite-chitosan surface on the microhardness of demineralized tooth enamel.

 In this laboratory study, boron nanocomposites doped on the hydroxyapatite-chitosan surface were made by the sol-gel method. A total of 45 healthy human teeth were selected and divided into buccal and lingual halves. The demineralization cycle of the samples was performed for 14 days to demineralize the tooth enamel surface. The samples were randomly divided into three equal groups based on the use of remineralizing materials, G1:hydroxyapatite-chitosan nanocomposites; G2:boron nanocomposites doped on the hydroxyapatite-chitosan surface, and G3:control group without nanocomposite. Nanocomposites were applied on the surface of the teeth for 28 days (twice a day). The microhardness of the samples was performed by the Vickers test at three points. The SPSS software (version 19), one-way analysis of variance, and Tukey's test were used for statistical analysis of the data (α=0.05). The surface morphology of the groups was examined by SEM[A1] .

 There was a statistically significant difference between the three studied groups (P<0.001). The highest mean was first observed in the G2(368.12) and then in the G1(342.62). Moreover, the lowest mean was related to the control group(267.53). Pair-by-pair comparison of groups showed that there was a significant statistical difference between groups 1 and 2, 1 and 3 as well as 2 and 3 (P<0.05).

 Both HApC and B@HApC compounds improve remineralization and increase the microhardness of tooth enamel; however, this increase was greater in the presence of a boron-containing compound.

Boron is widely found in raw materials and wastewater of the tile industry and its removal from aquatic environments is very complex. The aim of this study was to remove boron from wastewater of ceramic tile industry using coagulation and flocculation-adsorption process.

This was an experimental study. Initially, for the coagulation process, pH parameters between 5 to 11, concentrations of 150 to 450 mg/L of poly-aluminum chloride (PAC) and concentrations of 0.5 to 2.5 mg/L of anionic and cationic polymers were examined. Then, in the adsorption process, the effect of pH between 2 to 7 at contact times of 5 to 20 min was investigated. Finally, the data were analyzed using Pearson’s correlation test.

The results showed that the percentage of boron removal by poly-aluminum chloride at the optimum pH equal 8 and the concentration of 400 mg/L was 35.7% and in combination with 1.5 and 2.5 mg/L anionic and cationic polymer, removal efficiency of 54.2 % (from 35 to 16 mg/L) was observed. Then, in the adsorption process with an optimum pH equal 5 and contact time of 15 minutes, removal efficiency of 50% (from 16 to 8 mg/L) was obtained. Examination of isotherms in the adsorption process showed that boron adsorption follows the Freundlich isotherm and first-degree kinetics.

According to the results, the combined process of coagulation and flocculation with adsorption can be introduced as an effective process in boron removal.

Osteoarthritis is the most common joint disorder in modern societies. Elemental boron supplementation can support the influential effect of calcium, magnesium and vitamin D in the body. In that regard, the purpose of this study was to investigate the effect of boron on damaged knee joint cartilage in rats. In this study 30 adult Sprague Dawley male rats were randomly divided into five groups: Control group with no intervention, Sham group with 50 ml saline (vehicle) injection into the right knee joint space, Mono- sodium acetate (MIA) group with 3 mg MIA injection into articular space, prophylactic group with 3 mg MIA injection into articular space and 15 mg/kg boron in drinking water, receiving daily from the first day of injection and therapeutic group with 3 mg MIA injection into articular space and 15 mg/kg boron in drinking water, receiving daily from the third week after injection. Seven weeks after injections, the animals were killed, right knee joint were fixated, decalcified and processed. Five micrometer articular slides were stained with Safranin O + Fast Green. Articular cartilage injuries were assessed in accordance with the Modified Mankin's grading system based on the rate of articular cartilage staining and the number of chondrocyte colonies in the articular cartilage. Articular cartilage staining, mean number of chondrocyte colonies and cartilage chondrocytes in MIA, therapeutic and prophylactic groups significantly reduced in compare to control. On the other hand, the degree of articular cartilage staining, mean number of chondrocyte colonies and cartilage chondrocytes were significantly increased in both therapeutic and prophylactic groups in compare to MIA group (P<0.05). In the present study, boron could greatly reduce the effects of MIA and prevent cartilage damage. It also showed a good therapeutic effect in preventing the destruction of cartilage in this osteoarthritis model.