24 research outputs found

    Root and Canal Morphology of Mandibular Molars in a Selected Iranian Population Using Cone-Beam Computed Tomography

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    Introduction: The aim of this study was to evaluate the root canal morphology of mandibular first and second molars using cone-beam computed tomography (CBCT) in northern Iranian population and also to indicate the thinnest area around root canals. Methods and Materials: We evaluated CBCT images of 154 first molars and 147 second molars. By evaluating three axial, sagittal and coronal planes of each tooth we determined the number of root canals, prevalence of C-shaped Melton types, and prevalence of Vertucci configuration and inter orifice distance. Also the minimum wall thickness of root canals was determined by measuring buccal, lingual, distal and mesial wall thicknesses of each canal in levels with 2 mm intervals from apex to orifice. Results: Amongst 154 first mandibular molars, 149 (96.7%) had two roots, 3 (1.9%) had three roots and 2 (1.2%) had C-shaped root configuration. Of 147 second mandibular molars, 120 (81.6%) had two roots, 1 (0.6%) had three roots and 26 (17.6%) had C-shaped roots. There was no significant difference in the prevalence of Vertucci’s type between two genders. The most common configuration in mesial roots of first and second molars were type IV (57%-42.9%) and type II (31.5%-28%). Mesial and distal walls had the most frequency as the thinnest wall in all levels of root canals with mostly less than 1 mm thickness. In second molars the DB-DL inter orifice distance and in first molars the MB-ML distance were the minimum. MB-D in first molars had the maximum distance while ML-DL, MB-DB and ML-D had the same and maximum distance in second molars. Conclusion: Vertucci’s type IV and type I were the most prevalent configurations in mesial and distal roots of first and second mandibular molars and the thickness of thinnest area around the canals should be considered during endodontic treatments.Keywords: Cone-Beam Computed Tomography; C-Shaped Root Canals; Mandibular First Molar; Mandibular Second Molar; Root Canal Anatomy; Root Canal Morpholog

    The effects of CPAP therapy on metabolic profile and subjective sleep parameters in patients with OSA: a prospective trial study

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    Objective: Several studies confirmed a positive association between obstructive sleep apnea (OSA) and metabolic syndrome. Continuous positive airway pressure (CPAP) is the main treatment for patients with moderate and severe OSA. CPAP therapy in adults with OSA results in reduction in sleepiness, blood pressure and improvement of metabolic profile. In this study, we aimed to evaluate the effects of CPAP therapy on various components of metabolic syndrome and subjective sleep parameters in patients with OSA. Material and Methods: In this prospective trial study, 28 patients with moderate and severe OSA enrolled. Patients were asked to fill out the validated Persian version of questionnaires including Epworth sleepiness scale, insomnia severity index, STOP-BANG and Beck depression inventory - II, before and after treatment with CPAP. Weight and blood pressure were recorded before and after treatment. Only 14 patients agreed to blood sampling before and after CPAP therapy (at least 3 months of treatment). Fasting blood samples were analyzed for measuring the levels of FBS (fasting blood sugar), TG (triglyceride), total cholesterol, HDL, LDL, AST, and ALT. Results: Diastolic blood pressure, ISI and STOP-BANG score significantly decreased after treatment (p-value: 0.008, 0.022 and 0.004, respectively). FBS and TG levels decreased after treatment, but only TG levels had significant difference (p-value: 0.46 and 0.016, respectively). Discussion: CPAP therapy had positive effects on diastolic blood pressure, TG levels and ISI score. More studies with larger sample size and longer follow-up periods are warranted to investigate the effects of CPAP therapy on blood pressure, and metabolic parameters

    Berberine as a Natural Modifier of Gut Microbiota to Promote Metabolic Status in Animal Studies and Clinical Trials: A Systematic Review

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    As a phytochemical, berberine can modulate metabolic parameters via altering gut flora. However, findings are conflicting. In the present systematic review, we aimed to summarize the effects of berberine on gut microbiota in the models of metabolic disorders in both animal studies and clinical trials. Publications in five electronic databases including PubMed, SCOPUS, EMBASE, Web of Science, and Cochrane Library were searched systematically up to 31 May 2021 to find relevant articles with English language. Out of 4102 studies (including 2125 duplicates), 35 studies were included. In animal studies, various effects of berberine on beneficial and harmful microbiota were reported. However, findings also indicated that berberine can decrease the Firmicutes to Bacteroidetes (F/B) ratio. Three out of five studies showed positive effects of berberine on the production of short-chain fatty acids (SCFA), particularly butyrate. In three animal studies, Lipopolysacaride (LPS) concentrations decreased with berberine administration. In clinical trials (n=3) positive effects on microbiota and metabolic status were also reported. However, the quality of clinical trials was mainly low.The present systematic review showed that berberine can modulate key metabolic parameters through improving the balance of intestinal microbiome, decreasing the abundance of harmful microbiota and LPS concentrations, and increasing the production of SCFAs, particularly butyrate in animal models. However, there are limited high-quality evidence regarding the effects of berberine on gut flora in clinical trials. Although berberine can be an effective prebiotic supplement to modulate metabolic parameters, further high-quality clinical trials are needed to confirm this potential

    Removal of Cd(II), Ni(II), and Pb(II) Ions in an Aqueous Solution by Chemically Modified Nanoporous MCM-41

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    MCM-41 includes a group of silica mesopore components with a high surface area whose adsorption capacities can be enhanced by modifying their surface with amine groups. In this study, the modified NH2-MCM-41 was used to investigate adsorption of Cd(II), Ni(II) and Pb(II) ions in a mixture of aqueous solutions. All the experiments were carried out in a batch system containing a solution of metal ions to study the effects of the initial metal concentration, adsorbent dosage, contact time, and solution pH. The results showed that optimum adsorption would be achieved at pH 5 and that adsorption capacity increased with increasing metal ion concentration but with decreasing adsorbent dosage. Experimental data were fitted with Langmauir and Freundlich models. Maximum adsorption capacities for Ni(II), Cd(II), and Pb(II) were 12.36, 18.25 and 57.74 mg/g, respectively. The results indicate that NH2-MCM-41 is an effective adsorbent for Ni(II), Cd(II) and Pb(II) ions with a high adsorption capacity

    Rare Earths in fluorite deposits of Elika Formation (East of Mazandaran Province

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    Introduction The Central Alborz in eastern Mazandaran province is host to the most important carbonate-hosted fluorite deposits in Iran, such as Pachi-Miana, Sheshroodbar, Era and Kamarposht. In these deposits, mineralization occurs in the upper parts of the middle Triassic Elika formation (Vahabzadeh et al., 2009 and references therein). These deposits have long been studied, and various models are presented for ore genesis. Nevertheless, ore genesis in these deposits is still unclear. The present study of the geochemistry of the REEs of these deposits is intended to improve genetic models. Materials and methods Three hundred samples were taken from above mentioned deposits. Samples were categorized into 5 groups: (1) fluorite ore types, (2) ore-stage calcite, (3) carbonate host rocks, (4) basaltic rock around the deposits, and (5) shale of the Shemshak formation. Fourteen pure fluorite samples, 4 samples of pure calcite, 4 samples of carbonate host rock, 1 sample of basalt and 1 sample of shale were analyzed for REEs by ICP-MS at West Lab in Australia. Results Analytical data on fluorite from the Elika deposits show very low REE concentrations (0.5-18ppm), in calcite(0.5-3ppm) in carbonate host rocks – limestone (1.8-7ppm), and in dolomitic limestone 6.5ppm, compared with upper Triassic basalt (43ppm) and shale (261ppm). REE in fluorite of these deposits are strongly enriched (10 3 to 10 6 times) relative to normal sea water, ore stage calcite and carbonate host rocks, especially for mid-REEs (Eu, Gd) and heavy REEs (Lu, Yb, La/Yb=~0.05). Also, LREEs depletion (La/Sm= 2-10) and HREEs (La/Yb=0.01-0.08) relatively enrichment of fluorites compared with limestone (La/Sm=2.5-4, La/Yb=0.1-1.5) and dolomitic limestone (La/Sm=4.28, La/Yb=0.07-0.4) host rocks as well as positive Eu anomaly are the most important REEs signatures in fluorites. Fluorite elsewhere in the world with low total REE conten thas been interpreted to have a sedimentary origin (Ronchi et al., 1993; Hill et al., 2000; Sasmaz et al., 2005). Strong enrichment of REEs in fluorite and carbonate host rocks worldwide, relative to normal sea water indicates that diagenetic and/or hydrothermal processes have contributed to the process. Depletion of LREEs and moderately strong HREE enrichment in fluorite relative to carbonate host rocks is interpreted to be post-sedimentation (Ronchi et al., 1993;Hill et al., 2000). Thisis supported by the hydrothermal character of the fluorite in the Elika deposits and similarity between REE profiles and those of fluorine-rich MVT deposits with hydrothermal origin (Chesley et al.,1994; Bau et al., 2003). Positive Eu anomalies in fluorite elsewhere suggest deposition reduced conditions and temperatures~250°C (Bau et al., 2003; Sverjensky, 1989). The present study indicates that low total REEcontents in fluorite precipitated from reduced hydrothermal solutions could be caused by (1) increasing pH of the ore-forming solution during interaction with carbonate host-rock, (2) gradually decreasing F concentration in hydrothermal solutions due to different generations of fluorite mineralization, and (3) low REE contents of carbonate hostrocks. References Bau, M., Romer, R.L., Luders, V. and Dulski, P., 2003. Tracing element sources of hydrothermal mineral deposits: REE and Y distribution and Sr-Nd-Pb isotopes in fluorite from MVT deposits in the Pennine Orefield, England. Mineralium Deposita, 38(8): 992–1008. Chesley, J.T., Halliday, A.N., Kyser, T.K. and Spry, P.G., 1994. Direct Dating of MississipValley-type mineralization: Use of Sm-Nd in fluorite. Economic Geology, 89(9):1192-1199. Hill, G.T., Campbell, A.R., and Kyle, P.R., 2000. Geochemistry of southwestern New Mexico fluorite occurrences: implications for precious metals exploration in fluorite-bearing systems. Journal of Geochemical Exploration, 68(1): 1–20. Ronchi, L.H., Touray, J.C., Michard, A.¬ and Dardenne, M.A., 1993. The Riberia fluorite district, Southern Brazil. Geological and geochemical (REE, Sm–Nd isotopes) characteristics. Mineralium Deposita, 28(1): 40–52. Sasmaz, A., Yavuz, F., Sagiroglu, A.¬ and Akgul, B., 2005. Geochemical patterns of the Akdagmadeni (Yozgat, Central Turkey) fluorite deposits and implications. Journal of Asian Earth Sciences, 24 (3): 469–479. Sverjensky, D.A., 1989. The diverse origins of Mississippi Valley-type Zn–Pb–Ba–F deposits. Chronicle of mineral research and exploration, 495(1): 5 – 13. Vahabzadeh, G., Khakzad, A., Rasa, I.¬ and Mosavi, M.R., 2009. Study on S isotopes in galena and barite of Savad Kuh fluorite deposits. Journal of Basic Science, Islamic Azad University, 69(18): 99-108 (in Persian). <br

    Synthesis and Application of Chitosan Nanoparticles for Removal of Lead Ions from Aqueous Solutions

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    Biosorbents have become increasingly important for removal of heavy metal from water and wastewater due to their and biodegradability low costs. Chitosan is a hydrophilic and cationic polymer product of chitin deacetylation and used as an absorbent for removal of heavy metals. In the present study, the adsorption of Pb(II) metal ions from aqueous solution by chitosan nanoparticles was investigated. Nanoparticles are formed by reacting of the free amino groups of chitosan with carboxyl groups of maleic acid as crosslinking agent. Nanoparticles were characterized by Scanning Electron Microscopy (SEM) and fourier transform infrared spectrometry (FT-IR). The average size of the nanoparticles obtained was about 65-250 nm. Adsorption experiments were performed at room temperature in batch system. The effects of pH, concentration of metal ions and adsorbent dose were conducted. Optimization of adsorption was carried out by the initial solution pH ranged from 3 to 6, the initial metal ions concentration ranged from 10 to 100 mg/l and the adsorbent dose ranged from 1 to 7.5 g/l. Under these conditions, optimal values of initial pH solution, concentration of metal ions and adsorbent dose were found at 6, 100 mg/l and 2.5 g/l respectively. The maximum removal efficiently of 86% for Pb(II) in concentration of 10mg/l was achieved. The adsorption data fairly fitted to Langmuir and Freundlich isotherms. The maximum adsorption capacity of 25.8 mg/g based on Langmuir isotherm was obtained

    Lead Removal from Aqueous Solution Using Date-Palm Leaf Ash in Batch System

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    In this study potential usefulness of date-palm leaf (Phoenix dactylifera) ashes as an inexpensive adsorbent for Pb(II) ions has been demonstrated. For this purpose, some variables such as pH, Pb (II) ion concentrations, adsorbent dosage and temperature in batch systems were investigated. The obtained results showed that the optimum pH for removal of Pb (II) ions from aqueous solutions was equal to 5. Also, the adsorption efficiency at 60 minutes with 50, 100, 150, 200, 250 and 300 mg/l Pb(II) concentrations were 99.46, 91.47, 80.49, 69.62, 57.34 and 51.29% respectively, by 0.5 g/l adsorbent dosage and at temperature of 20ËšC. Consideration of adsorbent in this study showed that with increasing of adsorbent dosage from 0.1 to 2g/l the adsorption rate increased. Also, thermodynamic consideration showed that adsorption process was dependent to temperature and results showed that removal efficiency order was 40 ËšC > 30ËšC > 20 ËšC. This study concluded date-palm leaf ashes, have good potential as an adsorbent to remove toxic heavy metals like lead from aqueous solutions

    Combination of Nonionic Surfactants with Thermal-activated Persulfate for Simultaneous Removal of Phenanthrene and Pyrene from Alluvial Soil: A Kinetic Study

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    Polycyclic aromatic hydrocarbons have adverse effects on the organisms, plants, and soil structure. Therefore, they should be removed by an appropriate and effective method. In this study, simultaneous removal of 500 mg/kg(soil) of phenanthrene and pyrene was investigated for the individual and combined application of Tween 80, Triton X-100, and sodium persulfate from the alluvial soil. The results revealed that the maximum removal efficiencies of phenanthrene (94.06 +/- 0.30%) and pyrene (90.07 +/- 0.19%) were observed in the presence of Triton X-100 + sodium persulfate (0.5 M) within 1 hour, respectively. Also, individual application of surfactants and sodium persulfate had efficiencies of less than 80%. It should be noted that the removal of phenanthrene and pyrene followed the first-order kinetic model. Economic evaluations of combined treatment demonstrated that the application of more proportion of Triton X-100 (10000 mg/L) + less proportion of sodium persulfate (0.3 M) is more cost-effective for the remediation of soil in the field study. Based on the results, the combined application of the washing process by Triton X-100 and persulfate oxidant can significantly improve the removal efficiencies and is a promising technique in the remediation of polycyclic aromatic hydrocarbons contaminated soil

    Simultaneous anaerobic decolorization/degradation of Reactive Black-5 azo dye and chromium(VI) removal by Bacillus cereus strain MS038EH followed by UV-C/H2O2 post-treatment for detoxification of biotransformed products

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    The existence of synthetic dyes and heavy metals in textile wastewater is a serious problem. These compounds should be removed before discharge into the environment by an appropriate method. The present study was conducted for the characterization of efficient multi-functional strain Bacillus cereus MS038EH for the simultaneous removal of Reactive Black-5 and Chromium(VI). Maximum decolorization efficiency of 94.74% was achieved at pH 7, 35 degrees C, and 4% inoculum size for 900 mg/L of Reactive Black-5. Also, 94.10% efficiency was observed in the presence of 8 g/L of yeast extract as an optimum nitrogen source, while carbon sources had no significant effect on decolorization. It should be pointed out that the decolorization efficiency was decreased from 94 to 64% by increasing NaCl concentrations from 0 to 50 g/L, respectively. Bacillus cereus strain MS038EH could decolorize 94.31% of Reactive Black-5 (900 mg/L) and remove 87.31% of chromium(VI) (30 mg/L) within 36 h. Results of Gas chromatography-mass spectrometry and Fourier transform-infrared spectroscopy proved that Reactive Black-5 was cleaved into the lower molecular weight products without any azo bonds. However, the phyto-toxicity analysis showed that Reactive Black-5 was not toxic for Triticum aestivum and Maize, while biologically treated Reactive Black-5 was toxic for seeds. Therefore, ultraviolet-C/H2O2 was applied for the detoxification of biotransformed products. When ultraviolet-C/H2O2 was applied as post-treatment, the seeds were germinated completely. It is demonstrated that the application of ultraviolet-C/H2O2 after anaerobic treatment is effective for toxicity reduction of textile wastewater
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