Effect of hydroalcoholic extract of Matricaria chamomilla on passive avoidance memory and pain induced by global cerebral ischemia in Wistar rat

زمینه و هدف : ایسکمی مغزی و خونرسانی مجدد علت اصلی ناتوانی جدی و طولانی مدت در جهان است. هدف از مطالعه حاضر بررسی اثر عصاره هیدروالکلی بابونه بر اختلالات حافظه و درد ناشی از ایسکمی بود. روش بررسی: گل‌های خشک بابونه (Matricaria chamomilla) از عطاری تهیه شده و توسط الکل 70 درصد عصاره گیری شد. حیوانات به صورت تصادفی به 6 گروه 7 تایی تقسیم شدند. گروه کنترل فقط نرمال سالین دریافت کردند، گروه ایسکمی تحت ایسکمی قرار گرفته و نرمال سالین دریافت کردند، گروه شاهد(sham): تحت جراحی قرار گرفتند بدون اینکه شریان‌های کاروتید آن‌ها بسته شود. گروه‌های درمانی با عصاره تحت ایسکمی قرار گرفته و عصاره بابونه را به صورت داخل صفاقی در دوز 50، 100 و 200 میلی‌گرم بر کیلوگرم وزن بدن دریافت کردند. تست رفتاری توسط شاتل باکس و تست ضد درد توسط تست تیل فیلیک انجام شد. یافته ها : عصاره بابونه در غلظت‌های 50، 100 و 200 میلی‌گرم بر کیلوگرم حافظه احترازی غیرفعال موش‌های صحرایی تحت ایسکمی را به طور معنی‌دار افزایش داد. علاوه بر این عصاره بابونه زمان تأخیر ظهور رفلکس دردناک دم را در تست تیل فلیک به طور معنی‌داری افزایش داد و غلظت 50 میلی‌گرم بر کیلوگرم عصاره اثر بیشتری نسبت به غلظت‌های بالاتر آن نشان داد. بحث و نتیجه گیری: نتایج مطالعه حاضر حاکی از اثرات حفاظتی عصاره بابونه در برابر اختلال حافظه احترازی و درد ایجاد شده در اثر ایسکمی بود که احتمالا به دلیل اثرات آنتی‌اکسیدانی و ضدالتهابی عصاره گیاه می‌باش

Fibre Optic pH Sensor Using Optimized Layer-by-Layer Coating Approach

In this study the design and characterization of a high resolution wavelength dependent pH optical sensor fabricated using the layer-by-layer technique was undertaken. In this approach, brilliant yellow (BY) as a pH indicator and poly (allylamine hydrochloride) [PAH] as a cross-linker have been deposited on an uncladded silica fibre. A number of key parameters, such as the number of bilayers, the concentration of the BY solution and the shape of the fibre, as well as its core diameter have been varied with a view to optimizing the design and performance of the pH sensor. The results obtained from a series of evaluations show that the sensitivity was enhanced by reducing the concentration of the indicator solution used and by designing a U-bend configuration sensor probe with a sharply bent fibre. However, when making an overall comparison, the straight (unbent) fibre probe resulted in a more sensitive probe when compared to the use of a high radius bend. Further, utilizing a small core diameter of the fibre allows a wide pH range to be measured and with high sensitivity. Additionally, the performance was shown to be improved for measurements over a narrower range of pH, by using a fibre with a larger core diameter. Considering the effect of the number of layers, work carried out has shown that probes with 5-6 bilayers presented the best performance. The sensitivity has been shown to diminish when more than 6 layers were used and the sensing range shifts towards higher pH values. When monitored, the value of pKa (the dissociation constant) of the thin film showed the smallest change of any of the design factors considered. In summary, using a larger core diameter, employing a larger curve radius, a higher number of bilayers, a higher concentration of the indicator solution and applying PAH as an outer layer, all cause a higher pKa value and consequently the probe sensitivity moves towards alkaline region

Coupling of CFD and semiempirical methods for designing three-phase condensate separator: case study and experimental validation

This study presents an approach to determine the dimensions of three-phase separators. First, we designed different vessel configurations based on the fluid properties of an Iranian gas condensate field. We then used a comprehensive computational fluid dynamic (CFD) method for analyzing the three-phase separation phenomena. For simulation purposes, the combined volume of fluid–discrete particle method (DPM) approach was used. The discrete random walk (DRW) model was used to include the effect of arbitrary particle movement due to variations caused by turbulence. In addition, the comparison of experimental and simulated results was generated using different turbulence models, i.e., standard k–ε, standard k–ω, and Reynolds stress model. The results of numerical calculations in terms of fluid profiles, separation performance and DPM particle behavior were used to choose the optimum vessel configuration. No difference between the dimensions of the optimum vessel and the existing separator was found. Also, simulation data were compared with experimental data pertaining to a similar existing separator. A reasonable agreement between the results of numerical calculation and experimental data was observed. These results showed that the used CFD model is well capable of investigating the performance of a three-phase separator

Lutein and lutein esters in wheat during grain development and post-harvest storage

I R Soriano, H Y Law, N Raoufi-Rad and D J Mareshttp://meeting.aaccnet.org/cerealchem08/default.ht

Template-assisted extrusion of biopolymer nanofibers under physiological conditions

Biomedical applications ranging from tissue engineering to drug delivery systems require versatile biomaterials based on the scalable and tunable production of biopolymer nanofibers under physiological conditions. These requirements can be successfully met by a novel extrusion process through nanoporous aluminum oxide templates, which is presented in this study. With this simple method we are able to control the nanofiber diameter by chosing the size of the nanopores and the concentration of the biopolymer feed solution. Nanofiber assembly into different hierarchical fiber arrangements can be achieved with a wide variety of different proteins ranging from the intracellular proteins actin, α-actinin and myosin to the extracellular matrix components collagen, fibronectin, fibrinogen, elastin and laminin. The extrusion of nanofibers can even be applied to the polysaccharides hyaluronan, chitosan and chondroitin sulphate. Moreover, blends of different proteins or proteins and polysaccharides can be extruded into composite nanofibers. With these features our template-assisted extrusion process will lead to new avenues in the development of nanofibrous biomaterials

Radiation-induced expression of platelet endothelial cell adhesion molecule-1 in cerebral endothelial cells

Background: Radiation-induced molecular changes on the endothelial surface of brain arteriovenous malformaions (AVM) may be used as markers for specific vascular targeting agents. In this study, we examined the level of expression of platelet endothelial cell adhesion molecule-1 (PECAM-1) on brain endothelial cell surface after radiation treatment, with the aim of targeting the radiation-induced PECAM-1 on the AVM endothelium with prothrombotic agents to selectively occlude AVM vessels. Materials and Methods: Mouse cerebral endothelial cells (bEnd.3) were irradiated with 5, 15, or 25 Gy. Real-time quantitative polymerase chain reaction (PCR) and in-cell enzyme-linked immunosorbent assay (ELISA) were performed to quantify the temporal gene and surface PECAM-1 protein expression up to 168 hours post-irradiation. Two-tailed unpaired t-tests were used to determine statistical significance. Results: PECAM-1 gene expression was found to be significantly elevated post-irradiation in real-time quantitative PCR, with the maximum level of gene expression being evident at 120 hours post-irradiation representing an 11-fold increase in comparison to non-irradiated controls (p<0.001). In-cell ELISA detected a similar up-regulation for protein expression on the cell surface with delayed peak time. Conclusion: Ionising radiation can induce the up-regulation of PECAM-1 on brain endothelial cell surface. This protein may be a potential candidate for facilitating selective AVM vessel occlusion through the application of radiosurgery followed by vascular targeting.8 page(s

Self Doping of the Transport Layers Decreases the Bimolecular Recombination by Reducing Static Disorder

Electron transport layers ETLs have a crucial role in the solar cells performance. Generally, ETLs are characterized in terms of the interface properties and conductivity rather than their effect on the photoactive layer. Herein, two ETLs, 2,9 bis 3 3 dimethylamino propyl amino propyl anthra[2,1,9 def 6,5,10 d amp; 8242;e amp; 8242;f amp; 8242;]diisoquinoline 1,3,8,10 2H,9H tetraone PDINN and 2,9 bis[3 dimethyloxidoamino propyl]anthra[2,1,9 def 6,5,10 d amp; 8242;e amp; 8242;f amp; 8242;]diisoquinoline 1,3,8,10 2H,9H tetrone, are compared in the conventional PM6 Y6 organic solar cell OSC structure and the influence of the ETL on the photoactive layer is shown. It is shown that a significant portion of the unpaired electrons of PDINN is mobile by combining electron paramagnetic resonance and Hall effect measurements. It is established that the high doping in PDINN ETL changes the dark electron concentration of the photoactive layer. The impacts of this change in the photoactive layer can be observed in the reduced static energetic disorder, and subsequently in the nonradiative recombination of free carriers. The results can be used to suppress nonradiative recombination in OSC, which can significantly boost their efficienc