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

جستجوی thermo در مقالات مجلات علمی
  • Behzad Sharif Makhmalzadeh_Anayatollah Salimi * Aida Niroomand
    Poor bioavailability of ophthalmic drops is mainly due to drainage through the nasal-lacrimal duct and a very low permeability through corneal epithelium. The aim of our study was to prepare and characterize an ocular hydrogel of loratadine, as an example of a lipophilic drug, to increase drug concentration and residence time at the site of action in the eye. In this study,a 23full factorial design was employed to design and compare the properties of eight different loratadine - containing hydrogel formulations. Results showed a significant correlation between the swelling and porosity ratios of the hydrogels and the Pluronic percentage and Pluronic/carbomer ratio in the formulations. Moreover, the release profiles showed fast and sustained release of all the formulations. Evaluation of hydrogels structure by the FT-IR technique indicated that Pluronic interacts with hydroxyl and carboxylic groups in carbomer, which is the main reason for the hydrogel network formation and interacts with loratadine.The permeation of loratadine through rabbit cornea showed that drug permeation percentages for the F2 and F7 formulations were 15 and 70 folds more than that of the control.
    Keywords: Hydrogel, Thermo, responsible, Ocular drug delivery, Loratadine, Corneal permeability
  • Farhad Mohammadi, Soliman Mohammadi Samani, Nader Tanideh, Fatemeh Ahmadi *
    Purpose
    Cartilage regeneration by using polymeric scaffolds is a new option for treatment of osteoarthritis. A good scaffold for tissue engineering should copy the characteristics of natural extracellular matrix. The purpose of this study was to make a dosage form with proper reliability and stability for cartilage repair.
    Methods
    Hybrid scaffolds containing different ratios of hyaluronic acid (HA) and collagen were prepared and loaded with prednisolone as anti-inflammatory agent. Two different dosage forms (lyophilized implantable disk and thermo-sensitive gels) were examined. A scaffold of cross-linked HA was used as control. Different characterization tests were considered including differential scanning calorimetry (DSC), scanning electron microscopy, mechanical evaluations, and drug release.
    Results
    The physical and chemical performance of hybrid-scaffolds was better than HA scaffold. Increasing the concentration of HA and collagen improved the physical and chemical characteristics. Regarding the mechanical properties of the hybrid scaffold, the pore size was 20-200µm, compressive modulus was 54.77±0.31 kPa, more than 1200% water uptake was observed after 4 days, gelation temperature was 32±0.16°C, gelation time was 2.4±0.1 min, and drug release was controlled for 5 days by Higuchi release kinetic model.
    Conclusion
    It seems that this porous hybrid scaffold could be a suitable choice in cartilage regeneration as well as a controlled-release system for delivery of prednisolone in osteoarthritis.
    Keywords: Scaffold, Hyaluronic acid, Collagen, Implantable disk, Thermo, sensitive gel, Cartilage regeneration
  • یوسف دادبان شهامت، روشنک رضایی کلانتری، محمدعلی ززولی، علی بخشی، داریوش زینال زاده
    سابقه و هدف
    بسیاری از روش های گندزدایی متداول پساب دارای مشکلات راندمان پایین، مسایل فنی و هزینه های بالا می باشند. لذا این تحقیق به منظور افزایش کارایی فرایند گندزدایی پساب واقعی با استفاده از ازن زنی کاتالیزوری انجام شده است و از لحاظ اقتصادی با فرایند کلرزنی مورد مقایسه قرار گرفته است.
    مواد و روش ها
    در این فرایند، کربن فعال مغناطیسی به عنوان کاتالیست در راکتور نیمه پیوسته برای گندزدایی پساب شهری تصفیه خانه فاضلاب بندرگز در سال 1394 استفاده شد. راندمان گندزدایی با استفاده از شاخص کلیفرم های گرماپای صورت گرفت و تاثیر پارامترهای غلظت کاتالیست (صفر، 5/0، 1، 2 و 5 گرم در لیتر)، زمان تماس (1، 2، 5، 10، 20 و 40 دقیقه) و دانسیته میکروبی و بازیابی مجدد کاتالیست بر فرایند گندزدایی به روش شرایط بهینه مورد بررسی قرار گرفت و در پایان، هزینه های اقتصادی آن با روش مرسوم کلرزنی مقایسه گردید.
    یافته ها
    راندمان گندزدایی با افزایش غلظت نانوکامپوزیت کربنی و زمان تماس افزایش می یابد؛ به طوری که در غلظت g/L1 از کاتالیست، با 99/1 لگاریتم حذف پس از 2 دقیقه زمان تماس، استاندارد تخلیه پساب حاصل شد. این در حالی بود که کاهش میکروارگانیسم ها برای ازناسیون منفرد، 91/1 لگاریتم سنجش شد. ثابت سینتیک درجه اول فرایند در ازن زنی منفرد، min-142/0 بود که با افزودن کاتالیست (g/L2) افزایش 9 برابری یافت. هم چنین نانوکامپوزیت کربنی، بدون کاهش محسوس در راندمان (5/1 درصد)، تا 7 مرتبه مورد استفاده مجدد قرار گرفت و در بررسی اقتصادی، کاهش بیش از 57 درصد هزینه های گندزدایی در یک دوره 5 ساله، نسبت به کلریناسیون محاسبه گردید.
    استنتاج: روش ازن زنی کاتالیزوری با کاتالیست جدید به دلیل زمان اندک فرایند و راندمان بالا در گندزدایی پساب و نیز مقرون به صرفه بودن نسبت به روش های متداول می تواند به عنوان روشی موثر و مقرون به صرفه در تصفیه خانه های فاضلاب های شهری به کار رود.
    کلید واژگان: ازناسیون کاتالیزوری, پساب, گندزدایی, کلیفرم گرماپای, نانوکامپوزیت کربنی
    Yousef Dadban Shahamat, Roshanak Rezaei Kalantary, Mohammad Ali Zazouli, Ali Bakhshi, Dariush Zeynalzadeh
    Background and
    Purpose
    Many conventional disinfection methods of effluents raise some health, efficiency and economic concerns. In order to increase the efficiency of disinfection of real effluent, in this study, the catalytic ozonation process was performed and economically compared with chlorination.
    Materials And Methods
    Magnetic activated carbon was used as acatalyst in a semi-continuous reactor for disinfection of effluent of municipal wastewater treatment plant in Bandargaz, Iran in 2015. The efficiency of disinfection was determined by thermo-tolerant coliform as indication, and the effect of parameters such as catalyst concentration (0, 0.5, 1, 2, and 5 g/L), initial number of coliforms, contact time (1, 2, 5, 10, 20 and 40 min) and catalyst reuse on disinfection process was evaluated. Finally economic comparison was done with the chlorination.
    Results
    The results showed that the efficiency of disinfection was increased by increase in the concentration of carbon nano-composite and contact time; at 1 g/L concentration of Catalyst about 1.99 log reduction was observed after 2 min exposure time in which the effluent standards were obtained; while 1.91 log reduction of micro-organisms was measured for single ozonation. The first-order kinetics constant of single ozonation (0.42 min-1) showed an approximately 9-fold increase when the catalyst (2 g/L) was added to the solution. After 7 times reuse of nano-composite, the diminution of efficiency was negligible (1.5%); and more than 57% fall of the cost was observed in a 5-year operational period compared with chlorination.
    Conclusion
    The catalytic ozonation with the new catalyst of effluent could effectively disinfect the effluent in a short-contact-time, and due to economic considerations it can be used as an effective and economical method in wastewater treatment plants.
    Keywords: catalytic ozonation, effluent, disinfection, thermo, tolerant coliform, nano carbon composite
  • N. Banaee *, H.A. Nedaie
    Background
    7-LiF: Mg,Cu,P (GR-207A) is one kind of thermo-luminescent dosimeters (TLD) which can be used in diagnostic radiology and radiotherapy applications. Because of having suitable properties such as good sensitivity, small size and being tissue equivalent, thermo-luminescent dosimetry has been one of the most important techniques in medicine over many years. Choosing a correct energy for TLDs’ calibration is one of the most important factors in the accuracy of the absorbed dose.
    Materials And Methods
    In order to evaluate the effect of calibration energy on the response of GR-207A TLDs, calibration of the TLDs were done with 120kVp, 200kVp, 6MV, 18MV and 60Co beams. Then the responses of TLDs were normalized to 60Co and energy dependence was calculated for each dose step.
    Results
    The results confirmed that this kind of TLD dose not have the same response in different energies and reference dose affects on the amount of energy dependence.
    Discussion
    Energy dependence of this type of TLDs is more significant at lower energies compared to megavoltage beams. Relative response to 60Co illustrates that GR-207A dose not have uniform response to different steps of energies and the amount of energy dependence is totally different in various dose levels.
    Keywords: Dosimetry, thermo, luminescent dosimeters, TLD, energy dependence
  • Mrs. N. Banaee, H.A. Nedaie
    Background
    7-LiF: Mg,Cu,P (GR-207A) is one kind of thermo-luminescent dosimeters (TLD) which can be used in diagnostic radiology and radiotherapy applications. Because of having suitable properties such as good sensitivity, small size and being tissue equivalent, thermo-luminescent dosimetry has been one of the most important techniques in medicine over many years. Choosing a correct energy for TLDs’ calibration is one of the most important factors in the accuracy of the absorbed dose
    Materials And Methods
    In order to evaluate the effect of calibration energy on the response of GR-207A TLDs, calibration of the TLDs were done with 120kVp, 200kVp, 6MV, 18MV and 60Co beams. Then the responses of TLDs were normalized to 60Co and energy dependence was calculated for each dose step.
    Results
    The results confirmed that this kind of TLD dose not have the same response in different energies and reference dose affects on the amount of energy dependence.
    Discussion
    Energy dependence of this type of TLDs is more significant at lower energies compared to megavoltage beams. Relative response to 60Co illustrates that GR-207A dose not have uniform response to different steps of energies and the amount of energy dependence is totally different in various dose levels.
    Keywords: Dosimetry, thermo, luminescent dosimeters, TLD, energy dependence
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