13 research outputs found

    Insights into the Impacts of Synthesis Parameters on Lignin-based Activated Carbon and Its Application for: Methylene Blue Adsorption

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    In the current research, lignin was successfully extracted from industrial waste Kraft black liquor using the acid precipitation method. In the following step, powdered carbon was synthesized through the H3PO4-chemical activation method. The effects of synthesis parameters, including activation temperature (T) within the range of 400-600 ⁰C and two H3PO4/Lignin mass ratios (R) of 2 and 3 on activated carbon (AC) structure, were investigated. The physical and morphological properties of the ACs were obtained through BET, SEM, and FTIR analyses. The potential application of ACs was studied by measuring their adsorption capacity in the adsorption process of Methylene blue (MB) from an aqueous solution. The sensitized AC at R=2, and T= 500 ⁰C (AC-2-500) showed the highest specific surface area (1573.31 m2/g) and the pore volume (0.89 cm3/g), as well as the highest adsorption capacity of MB. This adsorbent was applied in the equilibrium adsorption experiments and kinetic description. The results from kinetic experiments and adsorption isotherms indicated that the pseudo-first-order model and Langmuir model were in correspondence with the experimental data most. The maximum adsorption capacity was 188 mg/g. The study proved there is a high potential for the conversion of black liquor to greatly porous Lignin-based adsorbents. Moreover, the considerable maximum adsorption capacity suggested a significant potential of Lignin-based AC for wastewater treatment

    Antimicrobial activity of three different endodontic sealers on the enterococcus faecalis and lactobacillus (in vitro)

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    Introduction: Growth and proliferation of the remaining microorganisms within the root canals may destroy the surrounding tissue of the root and leads to periapical lesion. Consequently, the complete elimination of microorganisms from the root canal is an important goal of endodontic therapy. Endodontic sealers do not provide complete seal in root canal system, and micro spaces have always remained between the material and canal walls that lead to penetration of these spaces, so, an antibacterial activity is essential for sealers. The aim of the present study was the in vitro evaluation of antimicrobial activity of the three endodontic sealers on two microorganisms. Methods: To study the effect of each sealer; AH26, MTA Fillapex and ADseal on Enterococcus Faecalis and Lactobacillus bacteria 10 samples were considered. In this experimental study, 60 plates were exposed to bacteria and 10 plates were considered for control group. Sealer antibacterial effect on bacterial growth was studied after 48 hours. Firstly, the freshly prepared sealers were poured inside the micro tube and diffused in the wall of the micro tube. Then solution of nutrient broth was poured into a micro tube and the determined volume of solution of bacterial suspension was added into a microtube and was kept 24 hours in the incubator to grow the bacteria. Then, it was poured in the plates of blood agar and cultured after 24 hours and then the colonies grown on the plates were counted in sufficient light. The data were analyzed with MANOVA statistical test and SPSS Version 18. Results: Most bacteria grew in the plates of ADseal sealer and MTA fillapex sealer with means of 5113.00CFU and 3077.00CFU respectively, while the lowest number of bacteria grew in the plates of AH26 sealer with a mean of 1345.15CFU. Conclusions: Most antibacterial activities of each enterococcus faecalis and lactobacillus bacteria sample was for AH26 sealer and MTA fillapex sealer. The lowest antibacterial activity was for ADseal sealer

    The global burden of cancer attributable to risk factors, 2010-19 : a systematic analysis for the Global Burden of Disease Study 2019

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    Background Understanding the magnitude of cancer burden attributable to potentially modifiable risk factors is crucial for development of effective prevention and mitigation strategies. We analysed results from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 to inform cancer control planning efforts globally. Methods The GBD 2019 comparative risk assessment framework was used to estimate cancer burden attributable to behavioural, environmental and occupational, and metabolic risk factors. A total of 82 risk-outcome pairs were included on the basis of the World Cancer Research Fund criteria. Estimated cancer deaths and disability-adjusted life-years (DALYs) in 2019 and change in these measures between 2010 and 2019 are presented. Findings Globally, in 2019, the risk factors included in this analysis accounted for 4.45 million (95% uncertainty interval 4.01-4.94) deaths and 105 million (95.0-116) DALYs for both sexes combined, representing 44.4% (41.3-48.4) of all cancer deaths and 42.0% (39.1-45.6) of all DALYs. There were 2.88 million (2.60-3.18) risk-attributable cancer deaths in males (50.6% [47.8-54.1] of all male cancer deaths) and 1.58 million (1.36-1.84) risk-attributable cancer deaths in females (36.3% [32.5-41.3] of all female cancer deaths). The leading risk factors at the most detailed level globally for risk-attributable cancer deaths and DALYs in 2019 for both sexes combined were smoking, followed by alcohol use and high BMI. Risk-attributable cancer burden varied by world region and Socio-demographic Index (SDI), with smoking, unsafe sex, and alcohol use being the three leading risk factors for risk-attributable cancer DALYs in low SDI locations in 2019, whereas DALYs in high SDI locations mirrored the top three global risk factor rankings. From 2010 to 2019, global risk-attributable cancer deaths increased by 20.4% (12.6-28.4) and DALYs by 16.8% (8.8-25.0), with the greatest percentage increase in metabolic risks (34.7% [27.9-42.8] and 33.3% [25.8-42.0]). Interpretation The leading risk factors contributing to global cancer burden in 2019 were behavioural, whereas metabolic risk factors saw the largest increases between 2010 and 2019. Reducing exposure to these modifiable risk factors would decrease cancer mortality and DALY rates worldwide, and policies should be tailored appropriately to local cancer risk factor burden. Copyright (C) 2022 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license.Peer reviewe

    Bacterial Leakage Assessment for Different Types of Resin-Based Dental Restorations Applied Using Various Placement Methods

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    Introduction: Although composite resins have improved greatly since their introduction, microleakage is one of the most frequently encountered problems. This study compared the effects of different monomer systems and layering techniques on the bacterial leakage of Cl I composite resin restorations. Methods: Eighty-two sound human third molars were used. The teeth were randomly divided into six groups of 12 teeth each and two positive and negative control groups of five teeth. Class I cavities, measuring 4×4×2 mm, were prepared. The first three groups were filled with a silorane-based composite (Filtek P90) using three different methods of filling (bulk, incremental and snowplow) and the remaining three groups were filled with a methacrylate-based composite (Clearfil AP-X) using the same techniques. The specimens were stored for 24 hours at 37°C and then thermocycled up to 1000 cycles. The bacterial leakage of the specimens was assessed in a microbiological laboratory and statistical analyses of data were performed by Fisher’s exact and chi-squared tests (P0.05). Conclusion: Leakage occurred similarly in both silorane- and methacrylate-based composite resins and three filling techniques.

    A study on the possibility of drug delivery approach through ultrasonic sensitive nanocarriers

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    Physical drug delivery through smart nanocarrier and external stimulus could lead to significant improvements of drug potency as well as noticeable decrease in unwanted side effects. Currently, many external energy sources such as light, magnetic fields, ultrasound, ...,  are under investigation as external stimulus for physical drug delivery. The purpose of this paper is to review most recent developments of triggered release of drugs and biomolecules under external ultrasound exposure. A special attention has also been paid to the metal nanostructures for ultrasound mediated drug delivery and also, other nanostructures were also considered. We briefly introduced ultrasound regulation and safety consideration. Further it is concluded that the use of nanostructures for delivery of active biomolecules in combination with ultrasound as a stimulus to trigger drug release from the nanocarriers and increased drug penetration has gained much attention for effective drug delivery and overcoming difficulties of multi-drug resistance of cancer

    Evaluation of the quality of services delivered in qazvin’s hospitals to attract medical tourists: Joint commission international approach

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    Medical tourism can be considered as a travel to promote mental, physical, and spiritual health of individuals, families, and groups. The present study was aimed at evaluating the level of preparation of the selected hospitals in Qazvin to attract medical tourists based on the standards of Joint Commission International (JCI). The present study was a descriptive crosssectional research carried out in 7 hospitals of Qazvin. The data collection instrument was the translated version of Joint Commission International Standards Checklist which includes 13 standards. The patient-and organization-oriented sections include 7 and 6 standards, respectively. The checklist was based on a 5-point Likert scale. Descriptive statistics techniques were employed to analyze the collected data. Among the 7 patient-oriented standards, the highest and lowest preparation scores were respectively related to Anesthesia and Surgical Care (77.5%) and Patient and Family Education (52.5%). Among the 6 organization-oriented standards, the highest and the lowest preparation scores were respectively related to management of information and communication (75.8%) and Facility Management and Safety (50%). According to the results of the present study, it seems that the hospitals under investigation had a relative preparation in attracting medical tourists. One of the most significant weakness of hospitals was lack of a systematic educational program for the personnel and patients and their families; therefore, it is recommended that necessary measures be taken in this regar
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