84 research outputs found
bbThermodynamic quantities and Urmia Sea water evaporation
The relation between climatic parameters (relative air humidity) and the water activity of the Urmia Sea water determines the possible maximum evaporation of the lake. Using the Pitzer thermodynamic approach, the activity of the Urmia Lake water during evaporation was calculated and compared to the present relative air humidity above the water. Present climatic conditions allow the Urmia Sea water to evaporate down to water with activity of 0.55, corresponding to the lowest air humidity measured over the lake. This water activity falls in the range of halite precipitation, while carnalite precipitation starts at somewhat lower (a H2O = 0.499) point. Our dynamic model predicts that for air humidity as low as 55% (reflecting present climate conditions), the Urmia Sea level may drop to as low as 1270 m (i. e., 1270 m above mean sea level). At that point, the lake water volume will have a volume of 11 km3. For the sake of comparison, at the beginning of 1990, the level of the lake was 1275 m, its volume was 25 km3, and its surface area was 5145 km2
Antimicrobial Photodynamic Therapy as an Adjunctive Modality in the Treatment of Chronic Periodontitis
INTRODUCTION: Due to penetration of pathogenic bacteria into the periodontal tissues in moderate to severe periodontitis, the mechanical methods are not sufficient in these cases. Therefore, administration of local/systemic antibiotic is recommended following mechanical root debridement. However, side effects of antibiotics such as microbial resistance and patient allergy led to development of alternative methods. One of the suggested methods is the antimicrobial photodynamic therapy (aPDT). aPDT is a local non invasive treatment modality without the side effects caused by antibiotics. The aim of this study was to collect the clinical articles related to the application of aPDT in the treatment of chronic periodontitis.METHODS: In order to find related clinical articles, a search of PubMed, Google Scholar and Science Direct until 2012 was performed.RESULTS: A total of 11 articles were found. In 7 of the 11 articles, the assessment of aPDT led to a significant improvement in the clinical attachment and probing depth. In 4 studies, there was no difference between the scaling & root planing (SRP) and adjunctive application of aPDT. aPDT in most cases resulted in less gingival bleeding compare to SRP alone. Furthermore, its application in multiple doses was more effective in comparison to a single dose treatment.CONCLUSION: It appears that aPDT is effective as an adjunctive therapy compared to conventional non_surgical treatment alone, and is recommended in multiple doses in order to achieve more appropriate results
Niosomal Formulation for Co-Administration of Hydrophobic Anticancer Drugs into MCF-7 Cancer Cells
Introduction: Designing and developing drug delivery systems has received tremendous attention during the last decade. The treatment of cancer cells is a complicated process due to the existence of different biological pathways. Therefore, the co-delivery of different drugs could have a synergic effect on the treatment process.Materials and Methods: In this study, different types of span (20, 60, 80) and cholesterol were utilized to formulate tamoxifen/curcumin co-loaded niosomes as a drug carrier system for breast cancer chemotherapy. Niosome characterization was performed through a set of instrument analysis techniques including scanning electron microscopy (SEM) and dynamic light scattering. Release behavior was studied by dialysis method at (pH = 5, 7.4). The stability was monitored during two months storage at two temperatures (4 and 25 °C). Cytotoxicity activity of the best niosomal formulation were assessed on MCF-7 cells, using MTT assay.Results: The optimal niosomal formulation with span 80 and lipid-to-drug molar ratio of 20 was selected, with maximum encapsulation of both drugs and minimum size. Drug release behavior at physiological pH (7.4) (with significant drug release under acidic conditions (pH = 5) and storage stability of up to 2 weeks with little change in drug efficacy and measurement makes it a proper candidate for breast cancer treatment.Conclusion: Finally, the results of this study showed the importance of creating highly biocompatible formulations, allowing the simultaneous transfer of two drugs with controlled release to cancer cells which could improve the chemotherapy process with the synergistic effect of the two drugs
Effect of Ginkgo biloba pill on patients with major depression treated with electroconvulsive therapy
Background and purpose: One of the most common complications of depression and treatment with ECT as one of the most effective treatments for depression is problem related to memory. This study was performed with aim of determination of the effects of Ginkgo pill on depression and cognition disturbance in this patients. Materials and methods: In this clinical trial study, 81 major depressed inpatients who was admitted in Hajar hospital allocated randomly in two groups (case and control). patients had indications of bilateral ECT. Before and at the end of treatment period with ECT, cognition status of patients was evaluated by Mini Mental State Exam questionnaire and depression severity was evaluated with Hamilton depression questionnaire. In case group, patients was treated with Ginkgo pill 40 mg each 8 hours and control group was treated with placebo for ECT treatment period (2weeks). Data analyzed by software SPSS 11 / 5 t-test, mean and ANOVA. Results: Between the two groups there was no statistically significant differences between age, gender, marital status, employment, duration of disease, depression and cognition score (P>0.05). The average scores in the field of cognitive problems and depression status of patients before and after ECT in both groups had significant difference (P<0.001) and case groups was better in both condition. Conclusion: Result of this study revealed the effectiveness of Ginkgo biloba in, cognition and depression status of major depress patients who treated with ECT, probably related to flavenoids and antioxidant component of this plant
Comparison of Fracture Resistance of the Endodontically Treated Roots with Two Sealer Types: An In Vitro Study
Evaluation of antibacterial effect of sesame oil, olive oil and their synergism on Staphylococcus aureus in vitro
Background and aims: Nosocomial infections are the main cause of the problems
related to health and health care costs. One of the pathogens that causes these infections
is Staphylococcus aureus. Its resistance to antibiotics forced researchers to find herbal
substitution such as Sesame and Olive. This study was aimed to determine antibacterial
effect of sesame oil, olive oil and their synergism on S. aureus.
Methods: In this experimental study, at first, olive oil and sesame oil was extracted by
cold press assay and the mixture of them was prepared with equal proportion of both
oils, and then the standard strain of lyophilized S. aureus ATCC 25923 was prepared
from the Iranian Research Organization for Science and Technology. To determine
minimum inhibitory concentration (MIC) and minimum bactericidal concentration
(MBC) of the oils, micro-broth dilution method was used.
Results: This study indicated the amounts of MIC for sesame oil, olive oil and their
synergism; 32 mg/ml, 32 mg/ml, 8 mg/ml and the amounts of MBC; 128 mg/ml,
128 mg/ml, 32 mg/ml, respectively.
Conclusion: The results showed the same antibacterial activity for olive oil and sesame
oil. It also showed that mixture of these oils enhances the growth inhibitory and
bactericidal properties of the oils compared to using them individually
The relationship between cellular adhesion and surface roughness for polyurethane modified by microwave plasma radiation
Surface modification of medical polymers is carried out to improve biocompatibility. In this study, conventional polyurethane was exposed to microwave plasma treatment with oxygen and argon gases for 30 seconds and 60 seconds. Attenuated total reflection Fourier transform infrared spectra investigations of irradiated samples indicated the presence of functional groups. Atomic force microscope images of samples irradiated with inert and active gases indicated the nanometric topography of the sample surfaces. Samples irradiated by oxygen plasma indicated high roughness compared with those irradiated by inert plasma for the different lengths of time. In addition, surface roughness increased with time, which can be due to a reduction of contact angle of samples irradiated by oxygen plasma. Contact angle analysis indicated a reduction in samples irradiated with both types of plasma. However, samples irradiated with oxygen plasma indicated lower contact angle compared with those irradiated by argon plasma. Cellular investigations with unrestricted somatic stem cells showed better adhesion, cell growth, and proliferation among samples radiated by oxygen plasma for longer than for normal samples
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