118 research outputs found
Spectrophotometric and Spectrofluorimetric Determination of Terazosin in Tablets by Eosin Y
تم وصف طريقتين بسيطتين وحساستين ودقيقتين لتقدير التيرازوسين . تعتمد الطريقة الطيفية (A) على قياس امتصاص معقد التجمع الايوني الناتج من ارتباط التيرازوسين مع الايوسينY في وسط الخلات المنظم دالته الحامضية 3 عند الطول الموجي 545 نانوميتر. الطريقة (B) تعتمد على تأثير الاخماد الكمي للتيرازوسين على شدة تفلور الايوسين عند الدالة الحامضية 3.5. اذ تم قياس الاخماد في شدة تفلور الايوسينYعند 556 نانوميتر بطول موجة اثارة 345 نانوميتر، اتبعت الطريقتين قانون بير ضمن مديات التراكيز 0.1-8 مايكروغرام/مللتر و0.05-7 مايكروغرام/مللتر للطريقتين A وB على التوالي. وتم تطبيق كلتا الطريقتين بنجاح في تقدير التيرازوسين في الاقراص الدوائية..Simple, sensitive and accurate two methods were described for the determination of terazosin. The spectrophotometric method (A) is based on measuring the spectral absorption of the ion-pair complex formed between terazosin with eosin Y in the acetate buffer medium pH 3 at 545 nm. Method (B) is based on the quantitative quenching effect of terazosin on the native fluorescence of Eosin Y at the pH 3. The quenching of the fluorescence of Eosin Y was measured at 556 nm after excitation at 345 nm. The two methods obeyed Beer’s law over the concentration ranges of 0.1-8 and 0.05-7 µg/mL for method A and B respectively. Both methods succeeded in the determination of terazosin in its tablet
The Structural Synthesis of Non-fractionated, Three-degree-of-freedom Planetary Gear Mechanisms
Planetary gear trains (PGTs) with one or more degrees of freedom (DOFs) have numerous uses in PGT-based mechanisms. The majority of the currently available synthesis methods have focused on 1-DOF PGTs, with only a few investigations on multi-DOF PGT synthesis. The method for synthesizing 7-link 3-DOF PGMs is outlined. All possible link assortments are produced, labeled spanning trees are generated, and potential geared graphs are constructed. The guidelines for including geared edges and how to synthesize geared graphs are outlined. Vertex-degree arrays are generated to validate the geared graphs. Isomorphic geared graphs are identified by comparing the isomorphic identification numbers of geared graphs with the same spanning tree. Fractionated geared graphs are identified using the reachability matrix method. The new method has a straightforward algorithm. In contrast to what is reported in the literature, the results of the synthesis of 7-link 3-DOF PGMs show that there are seven non-fractionated mechanisms. MATLAB programs are used to acquire the vertex-degree arrays
Spatial planning, urban governance and the economic context: The case of 'Mehr' housing plan, Iran
With the increasing concentration of population and economic activities in metropolitan regions, dwelling shortages and housing quality have become critical issues in urban management. Town plans considering social, economic, political, and cultural features of local communities have been developed with the aim of supporting housing, especially in emerging economies. In Iran, the 'Mehr Housing' Plan has been considered as one of the most relevant strategies for social housing since the 2000s. However, the acceptance of 'Mehr Housing' plans at the community scale has been rather low, reflecting the fact that it is a top-down, non-participatory policy. The present study investigates the most important factors affecting social acceptance of 'Mehr Housing' plans by interviewing 45 experts through a structured questionnaire that evaluated multiple analyses' dimensions of housing and urban planning in Iran. Results showed that six dimensions (physical, institutional-managerial, economic, socio-cultural, legal, and locational) had contributed to social dissatisfaction with 'Mehr Housing' local initiatives. In particular, socio-cultural and legal dimensions were demonstrated to have a large impact on local communities' dissatisfaction
Non-syndromic cleft palate: Association analysis on three gene polymorphisms of the folate pathway in Asian and Italian populations
Periconceptional folic acid supplementation can reduce the risk of inborn malformations, including orofacial clefts. Polymorphisms of MTHFR, TCN2, and CBS folate-related genes seem to modulate the risk of cleft lip with or without cleft palate (CL/P) in some populations. CL/P and cleft palate only (CPO) are different malformations that share several features and possibly etiological causes. In the present investigation, we conducted a family-based, candidate gene association study of non-syndromic CPO. Three single nucleotide polymorphisms, namely, rs1801133 of MTHFR, rs1801198 of TCN2, and rs4920037 of CBS, were investigated in a sample that included 129 Italian and 65 Asian families. No evidence of association between the three genotyped polymorphisms and CPO was found in the Italian and Asian cases, indeed the transmission disequilibrium test did not detect any asymmetry of transmission of alleles. This investigation, although with some limitation, further supports that CL/P and CPO diverge in their genetic background
Novel MMP-inhibiting peptides for stabilizing atherosclerotic plaques
Aim:
Matrix-degrading metalloproteases (MMPs) play an essential role in the atherogenic process, from the initial lesion to plaque rupture. A growing body of evidence show that inhibition of MMP activity or rebalancing the MMP/TIMP (tissue inhibitor of MMP) equilibrium has a potential therapeutic strategy for atherosclerosis. We studied the in vitro effects of newly designed peptides on MMP activity in endothelial cells and macrophages.
Methods:
Eight peptides were designed in silico and synthesized using the solid phase synthesis and characterized by circular dichroism and Dynamic Light Scattering. The mouse macrophage cell line J774A.1 and the human endothelial cell line EA.hy926 were treated with the peptides (10 \ub5\uf06dM and 10 \ub5\uf06dM) for 24 hours. Then, conditioned medium was collected and MMP-2, and MMP-9 activity was determined by gelatin gel zymography.
Results:
Analysis of the zymograms showed that upon 10 \ub5M treatment in endothelial cells, three out of eight peptides reduced the activity of proMMP-9 and proMMP-2 by more than 60 and 40 percent, respectively. Whereas, upon treatment at 100 \ub5M the proMMP-9 levels were less or not reduced. These could be consequent to aggregation of the peptide at a concentration higher than 50 \ub5\uf06dM. In macrophages, two of these peptides reduced the activity of proMMP-2 by more than 40 percent, but had no effect on proMMP-9 activity. The peptides, did not show any effects on MMP mRNA levels.
Conclusions:
These data show that these peptides show a promising inhibitory effect on MMP-9 and MMP-2 activity in endothelial cells and macrophages
Angular and energy dependence of ion bombardment of Mo/Si multilayers
The process of ion bombardment is investigated for the fabrication of Mo/Si multilayer x-ray mirrors using e-beam evaporation. The ion treatment is applied immediately after deposition of each of the Si layers to smoothen the layers by removing an additional thickness of the Si layer. In this study the parameters of Kr+ ion bombardment have been optimized within the energy range 300 eV-2 keV and an angular range between 20 degrees and 50 degrees. The optical performance of the Mo/Si multilayers is determined by absolute measurements of the near-normal-incidence reflectivity at 14.4 nm wavelength. The multilayer structures are analyzed further with small-angle reflectivity measurements using both specular reflectivity and diffuse x-ray scattering. The optimal smoothening parameters are obtained by determining the effect of ion bombardment on the interface roughness of the Si layer. The optimal conditions are found to be 2 keV at 50 degrees angle of incidence with respect to the surface. These settings result in 47% reflectivity at 85 degrees (lambda = 14.4 nm) for a 16-period Mo/Si multilayer mirror, corresponding to an interface roughness of 0.21 nm rms. Analysis shows that the interface roughness is determined by ion induced viscous flow, an effect which increases with ion energy as well as angle of incidence. In order to determine the effect of intermixing of the Si and Mo atoms, the penetration depth of the Kr+ ions is calculated as a function of ion energy and angle of incidence. Furthermore, the angular dependence of the etch yield, obtained from the in situ reflectivity measurements, is investigated in order o determine the optimal ion beam parameters for the production of multilayer mirrors on curved substrates. (C) 1997 American Institute of Physics
Intraventricular Hemorrhage in Preterm Infants, Review Article
Intraventricular hemorrhage (IVH) or germinal matrix (GM) in other words, is a condition that can occur in premature births and can lead to long-term medical and developmental effects. While GM/IVH can happen in full-term infants, the hemorrhage in this group of infants is different from periventricular hemorrhage (PVH)/IVH in premature infants. Family members and caregivers of preterm infants and those at risk of preterm birth are confronted with two significant uncertainties concerning these newborns: Is the survival of this child likely? Will the child experience long-term sequelae, particularly developmental sequelae, if they survive? The significance of these questions lies in their potential to impact future medical decisions, including the level of intensity in the care provided. Infants born prematurely can suffer from various acquired lesions in the central nervous system (CNS), leading to long-term disability. These lesions include GM/IVH, periventricular white matter injury, hemorrhage, and diffuse injury to the developing brain. GM/IVH continues to be a major contributor to both illness and death in premature newborns. GM/IVH is primarily diagnosed by brain imaging techniques, typically cranial ultrasonography, as depicted below. Screening and serial examinations are essential for diagnosing GM/IVH, as it can occur without any noticeable clinical indications
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