Dissolution enhancement of gliclazide using pH change approach in presence of twelve stabilizers with various physico-chemical properties

Purpose. The micronization using milling process to enhance dissolution rate is extremely inefficient due to a high energy input, and disruptions in the crystal lattice which can cause physical or chemical instability. Therefore, the aim of the present study is to use in situ micronization process through pH change method to produce micron-size gliclazide particles for fast dissolution hence better bioavailability. Methods. Gliclazide was recrystallized in presence of 12 different stabilizers and the effects of each stabilizer on micromeritic behaviors, morphology of microcrystals, dissolution rate and solid state of recrystallized drug particles were investigated. Results. The results showed that recrystallized samples showed faster dissolution rate than untreated gliclazide particles and the fastest dissolution rate was observed for the samples recrystallized in presence of PEG 1500. Some of the recrystallized drug samples in presence of stabilizers dissolved 100% within the first 5 min showing at least 10 times greater dissolution rate than the dissolution rate of untreated gliclazide powders. Micromeritic studies showed that in situ micronization technique via pH change method is able to produce smaller particle size with a high surface area. The results also showed that the type of stabilizer had significant impact on morphology of recrystallized drug particles. The untreated gliclazide is rod or rectangular shape, whereas the crystals produced in presence of stabilizers, depending on the type of stabilizer, were very fine particles with irregular, cubic, rectangular, granular and spherical/modular shape. The results showed that crystallization of gliclazide in presence of stabilizers reduced the crystallinity of the samples as confirmed by XRPD and DSC results. Conclusion. In situ micronization of gliclazide through pH change method can successfully be used to produce micron-sized drug particles to enhance dissolution rate

Decentralized Adaptive Helper Selection in Multi-channel P2P Streaming Systems

In Peer-to-Peer (P2P) multichannel live streaming, helper peers with surplus bandwidth resources act as micro-servers to compensate the server deficiencies in balancing the resources between different channel overlays. With deployment of helper level between server and peers, optimizing the user/helper topology becomes a challenging task since applying well-known reciprocity-based choking algorithms is impossible due to the one-directional nature of video streaming from helpers to users. Because of selfish behavior of peers and lack of central authority among them, selection of helpers requires coordination. In this paper, we design a distributed online helper selection mechanism which is adaptable to supply and demand pattern of various video channels. Our solution for strategic peers' exploitation from the shared resources of helpers is to guarantee the convergence to correlated equilibria (CE) among the helper selection strategies. Online convergence to the set of CE is achieved through the regret-tracking algorithm which tracks the equilibrium in the presence of stochastic dynamics of helpers' bandwidth. The resulting CE can help us select proper cooperation policies. Simulation results demonstrate that our algorithm achieves good convergence, load distribution on helpers and sustainable streaming rates for peers

The effect of individual counseling, line follow-up, and free nicotine replacement therapy on smoking cessation in the samples of Iranian smokers: Examination of transtheoretical model

Background: According to transtheoretical model(TTM), Stage matched interventions are more effective in quitting. The objective of current study was to investigate the effect of individual counseling, line follow-up, and free nicotine replacement therapy(NRT) on smoking cessation in smokers who are in preparation stage of smoking. Materials and Methods: In a randomized clinical trial design, through sending the short message system, potential participants in preparation stage of smoking were recruited and divided into control(n=60)and treatment(n=50) groups. The treatment group received an in-person counseling, line follow-up, and free NRT. TTM variables trend; pros and cons of smoking, behavioral and experiential processes, temptation, were assessed at baseline, 3 and 6months follow-up along with point prevalence and continuous abstinence. Results: Continuous abstinence at 6-month follow-up were 3.3%(n=2) in control group and 46%(n=23) in the treatment group(x 2 = 34.041, P < 0.001). Time � group analyses indicated that except cons of smoking (P > 0.05), all TTM constructs had significantly changed; temptation(F=36.864, P<0.001), pros (F=12.172, P<0.001), experiential processes(F=3.377, P<0.001), and behavioral processes(F=11.131, P<0.001). Conclusion: Interventions based on TTM variables increased the quite rate in prepared and motivated people. Our findings suggest that interventions through individual counseling along with free NRT and line follow-up in people who prepare for quitting are beneficial for our country

Remote probing of inhomogeneous media using parameter optimization techniques

Remote probing of inhomogeneous media using parameter optimization technique

Integrated Performance Assessment of Engineering Projects at the Interface of Emergent Properties and Uncertainty

Investigation of the performance of engineering project organizations is critical for understanding and eliminating inefficiencies in today’s dynamic global markets. The existing theoretical frameworks consider project organizations as monolithic systems and attribute the performance of project organizations to the characteristics of the constituents. However, project organizations consist of complex interdependent networks of agents, information, and resources whose interactions give rise to emergent properties that affect the overall performance of project organizations. Yet, our understanding of the emergent properties in project organizations and their impact on project performance is rather limited. This limitation is one of the major barriers towards creation of integrated theories of performance assessment in project organizations. The objective of this paper is to investigate the emergent properties that affect the ability of project organization to cope with uncertainty. Based on the theories of complex systems, we propose and test a novel framework in which the likelihood of performance variations in project organizations could be investigated based on the environment of uncertainty (i.e., static complexity, dynamic complexity, and external source of disruption) as well as the emergent properties (i.e., absorptive capacity, adaptive capacity, and restorative capacity) of project organizations. The existence and significance of different dimensions of the environment of uncertainty and emergent properties in the proposed framework are tested based on the analysis of the information collected from interviews with senior project managers in the construction industry. The outcomes of this study provide a novel theoretical lens for proactive bottom-up investigation of performance in project organizations at the interface of emergent properties and uncertaint

Effect of licorice root hydroalcoholic extract to improve the quality of fertility in hyperandrogenism- induced polycystic ovary syndrome by letrozole in mice.

زمینه و هدف: سندرم تخمدان پلی­کیستیک (PCOS) شایع­ترین اختلال غدد درون­ریز در زنان می­باشد. این سندرم با علایم افزایش هورمون­های آندروژنی، عدم تخمک­گذاری، ناباروری و چاقی مشخص می­گردد. مهم­ترین نشانه برای وجود تخمدان پلی­سیستیک، افزایش آندروژن­های خونی می­باشد. هدف از این تحقیق بررسی اثر عصاره هیدروالکلی ریشه شیرین بیان بر عوارض هایپرآندروژنیسم ایجاد شده توسط تخمدان پلی کیستیک تجربی بر توان باروری موش­های سوری ماده می­باشد. روش بررسی: در این بررسی، 84 قطعه موش سوری به 6 گروه تقسیم شدند: گروه­های کنترل، هایپرآندروژن، تیمار 1 mg/kg)150 (، تیمار 2 mg/kg)300 (، تیمار 3 mg/kg)450 ( و تجویز شیرین­بیان تنها با دوز mg/kg450 صورت گرفت. گروه­های هایپرآندروژن و تیمار 21 روز متوالی لتروزول با دوز mg/kg 2 لتروزول از طریق خوراکی دریافت کردند. گروه­های تیماری دو ساعت بعد عصاره شیرین­بیان با دوزهای یاد شده از طریق خوراکی دریافت کردند. بعد از پایان دوره درمان از هر گروه 10 قطعه موش به طور تصادفی برای انجام فرایند لقاح داخل آزمایشگاهی انتخاب شدند. در روند لقاح داخل آزمایشگاهی درصد اووسیت­ها، میزان لقاح و رویان و بلاستوسیست و توقف آن­ها بین گروه­های مختلف مقایسه شد. یافته ها: مقایسه نتایج در گروه­های مختلف نشان داد که در گروه هایپرآندروژن عوامل باروری موش­ها به شدت افت کرده و عصاره شیرین بیان توانسته اثرات محافظتی نسبی داشته باشد. این اثرات در گروه تیمار 2 بیشتر بود. نتیجه­گیری: نهایتاً می­توان نتیجه گرفت که اثرات سوء استفاده از لتروزول، پتانسیل کاهش توان باروری در جنس ماده را داشته و استفاده از عصاره هیدروالکلی شیرین­بیان با دوز مناسب، بعنوان یک آنتی­اکسیدانت تا حدودی می­تواند اثرات سوء هایپرآندروژنیسم ناشی از سندروم تخمدان پلی­کیستیک بر توان باروری موش ماده را بهبود بخشد