Effects of Pentoxifylline and Alprostadil on Ocular Hemodynamics in Healthy Humans

PURPOSE. Alprostadil, a prostaglandin (PG)E 1 analogue and pentoxifylline, an alkylxanthine derivate, have been shown to exert vasodilatory effects in several vascular beds. The purpose of the present study was to investigate the effect of PGE 1 and pentoxifylline on the ocular circulation. METHODS. A placebo-controlled, double-masked, three-way, crossover study was performed in 15 healthy male subjects. Subjects received pentoxifylline (300 mg), PGE 1 (alprostadil 60 g), or placebo intravenously over 2 hours on three trial days. Choroidal red blood cell flow was assessed with laser Doppler flowmetry and pulsatile choroidal blood flow with laser interferometric measurement of fundus pulsation amplitude (FPA). Retinal blood cell flow was calculated based on the measurements of maximum erythrocyte velocity in a retinal vein assessed with bidirectional laser Doppler velocimetry, and diameter measurements of retinal vessels were obtained with a retinal vessel analyzer. RESULTS. Pentoxifylline increased FPA by 15.4% Ϯ 1.1% (P Ͻ 0.001 versus placebo and baseline). Alprostadil tended to increase FPA, but this effect did not reach the level of significance (P ϭ 0.07 versus placebo). Choroidal blood flow as measured with laser Doppler flowmetry tended to increase during pentoxifylline and PGE 1 infusion by 8.9% Ϯ 2.9% (P ϭ 0.062) and 4.5% Ϯ 6.2% (P ϭ 0.29), respectively, but none of these effects was significant. The drugs under study had no effect on mean red blood cell velocity in retinal veins, on retinal vessel diameters, intraocular pressure, blood pressure, or pulse rate. CONCLUSIONS. PGE 1 did not alter the parameters of retinal or choroidal circulation in healthy subjects. Pentoxifylline increased FPA, but did not change choroidal blood flow as measured with laser Doppler flowmetry and did not affect retinal blood flow parameters. Accordingly, neither pentoxifylline nor PGE 1 appears to be suitable to improve ocular blood flow in healthy subjects. Whether long-term treatment with alprostadil would improve choroidal blood flow in patients with vascular disease remains to be established. (Invest Ophthalmol Vis Sci

BOND STRENGTH OF CFRP RODS IN SIMPLY SUPPORTED RC BEAM WITH HANGING REGION

ABSTRACT This paper presents an experimental study on bond behavior of longitudinal bars in hanging region of RC beam failed in bond. In order to realize the bond splitting failure, CFRP rods were used as longitudinal reinforcement instead of steel bars. Totally sixteen simply supported RC beams were tested in order to know the magnitude of bond stress in hanging region. The main test variables are (a) transverse reinforcement ratio and additional embedment length in the hanging region, and (b) transverse reinforcement ratio in the shear span. Based on the test results a model for predicting tension force at the support was presented

Frequency of Electrolyte Derangement after Transurethral Resection of Prostate: Need for Postoperative Electrolyte Monitoring

Objective. To determine the electrolyte derangement following transurethral resection of prostate (TURP). Methods. All patients undergoing TURP from June 2012 to April 2013 were included. Preoperative electrolytes were performed within a week of procedures. Monopolar TURP using 1.5% glycine was performed. Serum Na + and K + were assessed within 1 hour postoperatively and subsequently if clinically indicated. Results. The study included 280 patients. Sixty-six patients (23.6%) had electrolyte derangement after TURP. Patients with deranged electrolytes were older (mean age of 73.41 ± 4.08 yrs. versus 68.93 yrs. ± 10.34) and had a longer mean resection time (42.5 ± 20.04 min versus 28.34 ± 14.64 min). Mean weight of tissue resected (41.49 ± 34.46 g versus 15.33 ± 9.74 g) and volume of irrigant used (23.55 ± 15.20 L versus 12.81 ± 7.57 L) were also significantly higher in patients with deranged electrolytes (all = 0.00). On multivariate logistic regression analysis preoperative sodium level was found to be a significant predictor of postoperative electrolyte derangement (odds ratio 0.267, S.E. = 0.376, and value = 0.00). Conclusion. Electrolyte derangement occurs in older patients, with larger amount of tissue and longer time of resection and higher volume of irrigant, and in those with lower serum preoperative sodium levels

ANALITICAL STUDY ON COMPRESISVE STRENGTH OF REACTIVE POWDER CONCRETE

This work focuses on development of Artificial Neural Networks (ANNs) in prediction of compressive strength of reactive powder concrete after 28 days. To predict the compressive strength of reactive powder concrete nine input parameters that are cement, water, silica fume, fly ash, Ground granulated blast Furnace slag, super plasticizer, fine aggregate, Quartz sand and steel fibres are identified. A total of 35 different data sets of concrete were collected from the technical literatures. Number of layers, number of neurons, activation functions were considered and the results were validated using an independent validation data set. A detailed study was carried out, considering single hidden layers for the architecture of neural network. The performance of the 9-3-1 architecture was the best possible architecture. The results of the present investigation indicate that ANNs have strong potential as a feasible tool for predicting the compressive strength of reactive powder concrete

Open for discussion till

ABSTRACT Basic aspects of noise sampling, signal processing and analysis, and data processing, analysis, and interpretation in vibro-acoustic diagnostics of turbine cavitation are investigated in a series of prototype and model experiments. Several weak points of the practice are identified, and improvements and new techniques are developed. These techniques enable extraction of data on cavitation details and early detection of detrimental effects met in turbine exploitation. A brief review of weak points of the practice, developed improvements, and new techniques, as well as examples of application, are presented in the paper. RÉSUMÉ Des aspects de base de l'enregistrement du bruit, des traitements et analyses analogiques et numériques des signaux, avec leur interprétation dans le diagnostic vibro-acoustique de la cavitation de turbine, sont étudiés dans une série d'expériences de prototype et de modèle. Plusieurs points faibles de la pratique sont identifiés, et des améliorations et de nouvelles techniques sont développées. Ces techniques permettent l'extraction de données sur des détails de cavitation et la détection précoce des effets néfastes rencontrés dans l'exploitation de turbine. Un bref examen des points faibles de la pratique, des améliorations développées, et de nouvelles techniques, aussi bien que des exemples d'application, sont présentés dans le papier

On the History of Computer Algebra at the Keldysh Institute of Applied Mathematics

Abstract: The authors consider the history of Computer Algebra (CA) developmen

The Effect of a Grain Boundary on Deformation in an Aluminum Bicrystal with a Common Tensile Axis of [100]

The effect of a grain boundary on deformation has been examined using an aluminum bicrystal specimen composed of crystals having a common tensile axis of [100] by the measurement of orientation change with the electron backscatter diffraction technique. After deformation to a strain of 20%, the crystal rotation axis (CRA) map, which provides the orientation distribution of crystal rotation axes relative to the initial crystal orientations, reveals areas affected by the grain boundary. The thickness of the affected zone was 100 mm in one crystal and 150 mm in the other. In both crystals, the crystal rotation axis relative to the initial crystal orientation differed between the affected zone and the crystal interior. In the crystal interior, two slip systems showed a higher activity than the other slip systems, whereas in the affected zone, three or four slip systems were more active than the other slip systems. The CRA map showed that the width and shape of the affected zones across the grain boundary were not symmetrical with respect to the grain boundary

A NEW OFF-LINE COMPUTER MODEL FOR IMPROVING WIDTH REDUCTION IN ROUUGHINHG TRAINS OF HOT STRIP MILLS OF MOBARAKEH STEEL COMPANY-Branch Member of Young researcher Club

ABSTRACT Edging of slab is an important process to reduce and control width in the roughing area of hot strip mills. Width reduction amount that is required for edger in every pass is computed in the form of a very complicated on-line computer model. The model which previously was used for computation of width in roughing strip mill of Iran's Foolad Mobarakeh Company did not have acceptable accuracy and caused many problems in final product width. Obviating these problems and adopting a reasonable and optimal way in allocating the width reduction amount of edger in every pass, the process of width reduction was put under close examination and an off-line computer model was written that precisely computes the width reduction. The performed computations by this model in roughing strip mill of this company were put to use; this was followed by very satisfactory results. Finally, according to the obtained results, the on-line model was corrected. Correction of the aforementioned model has had a significant effect in increase of quality and decrease of damages of hot strip mill products

Oyster Mushroom Cultivation on Different Cellulose Substrates

Abstract Four lignocellulosic substrates (sawdust, peat of coconut husk, narrow leaf cattails and bagasse) were used for Pleurotus ostreatus cultivation, and 3-6 flushes were obtained from these substrates. A bagasse substrate accelerated the mushroom growing processes. The mycelial completed colonization, primordium initiation and fruiting body formation were found within 28, 40 and 44 days, respectively. The sawdust gave the maximum mushroom yield (536.85 g per 1 kg substrate) and this yield was significantly different to those found from bagasse (360.84 g), peat of coconut husk (278.78 g) and narrow leaf cattails (112.10 g) at a confidence level of 95%. However, the highest percentages of biological efficiency was obtained in bagasse substrate even it showed lower mushroom yield than sawdust. Low percentages of biological efficiency were found in peat of coconut husk (56.76%) and narrow leaf cattails (44.67%). Even the highest percentage of biological efficiency was obtained from bagasse (103.56%) but this percentage was insignificant differences at a confidence level of 95% to those found in control (95.02%; sawdust). When the percentage of biological efficiency was taking into account the lignocellulosic substrate likes bagasse has shown great potential for use as a raw material instead of sawdust since this substrate provides an economically acceptable production alternative for P. ostreatus cultivation