Maximum Percentage Increase Research Articles

Overall heat transfer coefficient and pressure drop in a typical tubular exchanger employing alumina nano-fluid as the tube side hot fluid

Nano-fluids are used to improve the heat transfer rates in heat exchangers, especially; the shell-and-tube heat exchanger that is considered one of the most important types of heat exchangers. In the present study, an experimental loop is constructed to study the thermal characteristics of the shell-and-tube heat exchanger; at different concentrations of Al2O3 nonmetallic particles (0.0, 2, 4, and 6 %). This material concentrations is by volume concentrations in pure water as a base fluid. The effects of nano-fluid concentrations on the performance of shell and tube heat exchanger have been conducted based on the overall heat transfer coefficient, the friction factor, the pressure drop in tube side, and the entropy generation rate. The experimental results show that; the highest heat transfer coefficient is obtained at a nano-fluid concentration of 4 % of the shell side. In shell side the maximum percentage increase in the overall heat transfer coefficient has reached 29.8 % for a nano-fluid concentration of 4 %, relative to the case of the base fluid (water) at the same tube side Reynolds number. However; in the tube side the maximum relative increase in pressure drop has recorded the values of 12, 28 and 48 % for a nano-material concentration of 2, 4 and 6 %, respectively, relative to the case without nano-fluid, at an approximate value of 56,000 for Reynolds number. The entropy generation reduces with increasing the nonmetallic particle volume fraction of the same flow rates. For increase the nonmetallic particle volume fraction from 0.0 to 6 % the rate of entropy generation decrease by 10 %.

Experimental and numerical performance analysis of a converging channel heat exchanger for PV cooling

An experimental and numerical investigation of a cooling technique called as converging channel cooling intended to achieve low and uniform temperature on the surface of PV panel is presented in this paper. Experimental evaluation for an uncooled PV system and a converging channel cooled PV system was carried out subjected to the hot climate of Saudi Arabia for the month of June and December. Detailed modeling was performed using numerical analysis to investigate the effect of changing the converging angle on the thermal characteristics of the PV system. Based on the developed model, two degrees angle showed the best performance in terms of temperature distribution and average cell temperature with a standard deviation of 0.91°C. A comprehensive system model was developed to assess the performance of PV systems numerically by coupling the optical, radiation, thermal, computational fluid dynamics, and electrical model. Thermal measurements for an uncooled PV showed cell temperature as high as 71.2°C and 48.3°C for the month of June and December, respectively. By employing converging cooling, cell temperature was reduced significantly to 45.1°C for June and to 36.4°C for December. Maximum percentage improvement in power output was 35.5% whereas maximum percentage increase in the conversion efficiency was 36.1% when compared to the performance of an uncooled PV system. For cost feasibility of an uncooled and cooled PV system, levelized cost of energy (LCE) analysis was performed using the annual energy yield simulation for both systems. LCE was found to be 1.95(€/kWh) for an uncooled PV system which was reduced to 1.57(€/kWh) for converging cooled PV system with a relative percentage decrease of 19.5%, hence making it economically viable.

PP.27.03

Objective: Endothelial dysfunction is recognized as an independent risk factor for cardiovascular events. It is measured non-invasively as brachial artery flow-mediated dilation (FMD) and as reactive hyperemia index (RHI). This study aimed to address the relationship of these two methods for assessing endothelial function comparing the two possible techniques with lower (forearm) and upper (arm) cuff occlusion. Design and method: In 17 young healthy subjects (9 males, age 29 ± 4 years) FMD and RHI were measured simultaneously in two separate occasions by 5 minutes of ischemia with lower (L) and upper (U) cuff occlusion. FMD was measured by ultrasounds as maximum percentage increase in brachial diameter by an automated system (FMD studio, Quipu s.r.l., Pisa, Italy). Baseline and Hyperemic Shear rate (SR) were also computed. RHI was assessed by finger arterial tonometry (EndoPAT 2000, Itamar Medical, Israel) and log-transformed. Results: L-FMD (7.32 ± 4.87%) and L-RHI (0.61 ± 0.29%) were significantly lower (p < 0.05 and p < 0.01, respectively) as compared to U-FMD (10.48 ± 5.67%) and U-RHI (0.86 ± 0.23%). L-FMD was not related to U-FMD (r = 0.39; p = 0.12). No significant relation was found between L-RHI and U-RHI (r = 0.49; p = 0.06). L-FMD was significantly related to L-SR (r = 0.62; p < 0.01), but not to L-RHI (r = 0.17; p = 0.54). L-RHI was not significantly correlated with L-SR (r = 0.24; p = 0,38). U-RHI was related to U-FMD (r = 0.50; p < 0.05) and to U-SR (r = 0.50, p < 0.04). In multiple regression analysis (full model: r2 = 0.23) U-FMD but not U-SR was associated with U-RHI (r2 = 0.20; p = 0.05). Conclusions: In healthy subjects, the assessment of FMD and RHI with lower and upper cuff occlusion is not equivalent. L-FMD, but not U-FMD is related to SR increase, thus possibly representing a better marker for conduit artery endothelial function. Conversely, U-RHI and U-FMD are independently related, both providing similar information on vascular reactivity, although possibly less specifically for endothelial function. Thus, caution is deemed in interpreting studies on vascular reactivity conducted with different techniques and methodologies.

Initiation and failure mechanism of base instability of excavations in clay triggered by hydraulic uplift

Excavations in clay overlying an aquifer may cause catastrophic basal failure due to hydraulic uplift. Although case histories with hydraulic uplift failures are reported worldwide from time to time, the initiation and failure mechanism of the base instability are not well studied and understood. To address these two issues, dimensional analysis is firstly conducted to propose dimensionless groups (DGs) possibly relevant to this subject. Effects of these DGs on the initiation and failure mechanism of base instability are then investigated, by carrying out a series of finite element analyses, in which constitutive models and model parameters have been previously validated against centrifuge test results. It is revealed that the initiation and failure mechanism of base instability due to hydraulic uplift is mainly governed by a ratio of excavation width over the thickness of soft clay inside excavation (B/D). As excavation becomes narrower (i.e., B/D decreases), the hydraulic pressure (Pi) required to initiate uplift movement of clay inside excavation increases significantly (maximum percentage increase = 50%), due to increased effect of downward shear stress acting along soil–wall interface on basal resistance. Based on the parametric study, a calculation chart is developed for estimating Pi of excavations with varied B/D and undrained shear strength of clay. At basal failure caused by hydraulic uplift, the dominant failure mode changes from simple shear in relatively narrow excavations (i.e., B/D &lt; 4) to combined modes of triaxial compression, triaxial extension, and simple shear in relatively wide excavations (i.e., B/D &gt; 4).

Impaired Compensatory Responses to Hypovolemic Circulatory Stress in Women with Vasovagal Syncope

ObjectiveA fall in cardiac output (CO) due to a reduced venous return has been suggested as an important factor for the hemodynamic instability in vasovagal syncope (VVS). The aim was to investigate compensatory mechanisms to defend central blood volume during hypovolemic stress in women with VVS.Design and MethodsSingle (30 mmHg) and graded (20 to 70 mmHg) lower body negative pressure (LBNP) were used to create hypovolemic stress in 15 young women with VVS and 15 matched controls. Peripheral mobilization of venous blood from the arm (capacitance response), net fluid absorption and lower limb blood pooling were evaluated with volumetric technique. Hemodynamic responses and plasma norepinephrine (P‐NE) were measured.ResultsAlthough CO decreased in both groups during graded LBNP (P &lt; 0.05), VVS presented a significantly lower CO at LBNP of 40 mmHg (P = 0.045). Mobilization of capacitance blood from the peripheral circulation (ml/100 ml) was reduced in VVS (LBNP 40 mmHg, 0.194±0.02 vs. 0.299±0.02, P = 0.007; LBNP 50 mmHg, 0.172±0.01 vs. 0.314±0.04, P = 0.003), and net fluid absorption was ~40% lower (P = 0.019). VVS displayed a blunted percentage increase in P‐NE (P = 0.009) and a reduced maximal percentage increase in TPR (P = 0.041) during graded LBNP. Lower limb blood pooling was comparable in VVS and controls.ConclusionsImportant compensatory mechanisms to defend central blood volume during hypovolemic stress were impaired in VVS. This may seriously impede maintenance of cardiac output during hypovolemic stress and could contribute to the pathogenesis of VVS.

Análisis de la regresión temporal en el ensanchamiento del intervalo QRS inducido por bupivacaína con la administración de Intralipid. Estudio en un modelo experimental porcino

ObjectiveThe principal mechanism of cardiac toxicity of bupivacaine relates to the blockade of myocardial sodium channels, which leads to an increase in the QRS duration. Recently, experimental studies suggest that lipid emulsion is effective in reversing bupivacaine cardiac toxicity. We aimed to evaluate the temporal evolution of the QRS widening induced by bupivacaine with the administration of Intralipid. Material and methodsTwelve pigs were anesthetized with intravenous sodium thiopental 5mg kg−1 and sevoflurane 1 MAC (2.6%). Femoral artery and vein were canalized for invasive monitoring, analysis of blood gases and determination of bupivacaine levels. After instrumentation and monitoring, a bupivacaine bolus of 4-6mg kg−1 was administered in order to induce a 150% increase in QRS duration (defined as the toxic point). The pigs were randomized into two groups of six individuals. Intralipid group (IL) received 1.5mL kg−1of IL over oneminute, followed by an infusion of 0.25mL kg min−1. Control group (C) received the same volume of a saline solution. The electrocardiographic parameters were recorded, and blood samples were taken after bupivacaine and 1, 5, 10 and 30minutes after Intralipid/saline administration. ResultsBupivacaine (4.33±0.81mg/kg in IL group and 4.66±1.15mg/kg in C group) induced similar electrocardiographic changes in both groups; mean maximal percent increase in QRS interval was 184±62% in IL group, and 230±56% in control group (NS). Lipid administration reversed the QRS widening previously impaired by bupivacaine. After ten minutes of the administration of IL, the mean QRS interval decreased to 132±56% vs. 15±76% relative to the maximum widening induced by bupivacaine, in IL and C group, respectively. ConclusionIntralipid reversed the lengthening of QRS interval induced by the injection of bupivacaine. Time to normalization of electrocardiographic parameters can last more than 10minutes. While the phenomena of cardiac toxicity persist, resuscitation measures and adequate monitoring should be continued until adequate heart conduction parameters are restored.

Heat transfer performance of silver/water nanofluid in a solar flat-plate collector

An experimental study is carried out to investigate the heat transfer characteristics of silver/water nanofluid in a solar flatplate collector. The solar radiation heat flux varies between 800 W/m2and 1000W/m2, and the particle concentration varies between 0.01%, 0.03%, and 0.04%. The fluid Reynolds number varies from 5000 to 25000. The influence of radiation heat flux, mass flow rate of nanofluid, inlet temperature into the solar collector, and volume concentration of the particle on the convective heat transfer coefficient and the collector efficiency are studied. Both parameters increase with increase in the particle volume concentration and flow rate. The maximum percentage increase obtained in the convective heat transfer coefficient is 18.4% for the 0.04% volume concentration at a Reynolds number of 25000. An increase in the performance of nanofluid is also witnessed when compared to the base fluid, which has a strong dependency on volume concentration and mass flow rate. MgO. The nanofluid achieved a 3°C temperature difference during the daytime peak solar radiation compared with the base fluids. With a concentration of 0.2% ZnO, a temperature difference of 2.55°C for daytime and 1°C for nighttime was reached, and this was determined to be the most attractive option for solar energy utilization. Yousefi et al. [15] witnessed a 28% performance improvement in a flat-plate collector when it was operated with water-Al2O nanofluids. Tyagi [16] theoretically compared the conventional flat-plate collector with a direct absorption solar collector (DAC) and observed the former to be 10% more efficient. Otanicar [17] studied the conomic and environmental influences of using nanofluids to enhance solar collector efficiency with conventional solar collectors. Dongxiao et al. [18] presented excellent photothermal properties of carbon-black aqueous nanofluids at highvolume fractions. Further work on nanofluids’ application to direct solar absorption has been carried out by Lijuan Mu [19] using a custom-made direct solar absorber. The radiative properties of several nanofluids are tested for the highest temperature difference across the heat exchangers. Based on the above-mentioned review of the literature, it has been clearly observed that most of the previous studies on solar flat-plate collectors were conducted using metal oxide nanoparticles in relatively high concentrations. These high concentrations of metal oxide nanoparticles cause a higher pressure drop that then requires a higher pumping power. Since a limited number of studies exists in the literature with respect to pure metal nanoparticles, it is recommended to study the heat transfer characteristics of pure metal nanoparticles with relatively low concentrations (<1%) by volume and high thermal conductivity compared with metal oxides. Therefore, in the present study, the efficiency of a solar flat-plate collector is studied with a low particle volume concentration of less than 0.04% silver-water nanofluid. These experiments are conducted for a solar radiation flux ranging from 800 W/m2 to 1000 W/m2, and the Reynolds number varying from 5000 to 25000. The effect of radiative heat flux, mass flow rate, inlet temperature, and volume concentration on the convective heat transfer coefficient and the collector efficiency are studied. The tailormade setup for a collector area is 2.4m2 and the collector plate is made of nine parallel copper strips

Sex-specific alterations in NOS regulation of vascular function in aorta and mesenteric arteries from spontaneously hypertensive rats compared to Wistar Kyoto rats.

The present study tested the hypothesis that spontaneously hypertensive rats (SHR) have impaired nitric oxide synthase (NOS)‐mediated regulation of vascular function versus Wistar‐Kyoto rats (WKY). Aorta and small mesenteric arteries were studied from male and female SHR (M SHR and F SHR) and WKY (M WKY and F WKY). Phenylephrine (PE)‐induced vasoconstriction was greater in aorta of M SHR versus all others (P < 0.05); there were neither sex nor strain differences in PE contraction in mesenteric arteries. The NOS inhibitor l‐Nitro‐Arginine Methyl Ester (l‐NAME) increased PE‐induced vasoconstriction in all rats, although the increase was the least in male SHR (P < 0.05), revealing a blunted vasoconstrictor buffering capacity of NOS. l‐NAME increased sensitivity to PE‐induced constriction only in mesenteric arteries of SHR, although, the maximal percent increase in contraction was comparable among groups. ACh‐induced relaxation was also less in aorta from M SHR versus all others (P < 0.05). ACh relaxation was comparable among groups in mesenteric arteries, although SHR exhibited a greater NOS component to ACh‐induced relaxation than WKY. To gain mechanistic insight into sex and strain differences in vascular function, NOS activity and NOS3 protein expression were measured. Aortic NOS activity was comparable between groups and M SHR had greater NOS3 expression than M WKY. In contrast, although vascular function was largely maintained in mesenteric arteries of SHR, NOS activity was less in SHR versus WKY. In conclusion, M SHR exhibit a decrease in NOS regulation of vascular function compared to F SHR and WKY, although this is not mediated by decreases in NOS activity and/or expression.

Assessing Articulatory Speed Performance as a Potential Factor of Slowed Speech in Older Adults

PURPOSE To improve our understanding about the underlying factors of aging-related speaking rate decline, the authors sought to determine if lip and jaw speeds are physiologically constrained in older adults. METHOD Thirty-six females-10 young adults (ages 22-27 years), 9 middle-aged adults (ages 45-55 years), 10 young-old adults (65-74 years), and 7 very old adults (ages 87-95 years)-completed metronome-paced syllable repetitions while moving the lower lip or jaw to a fixed target with each repetition. Metronome paces incrementally increased from 1.4 Hz to 6.7 Hz. Lip and jaw movements were tracked using a 3-dimensional motion capture system. RESULTS Older adults' maximum percent increase in lip and jaw peak speed was comparable to or tended to be even greater than that of middle-aged and young adults. By contrast, lip and jaw stiffness, indexed by peak speed-displacement ratios, tended to decrease with age during fast and very fast repetition rates and were associated with mildly prolonged movement durations. CONCLUSIONS The findings suggest that lip and jaw speeds are not constrained in older adults. The trend of reduced stiffness during fast rates, however, suggests that fine-force regulation becomes difficult for older adults. Thus, older adults may implement reduced habitual speaking rates as a behavioral strategy to compensate for diminished articulatory control.

Biochemical alterations in leaves of resistant and susceptible cotton genotypes infected systemically by cotton leaf curl Burewala virus

Leaf curl disease caused by Cotton Leaf Curl Burewala virus (CLCuBuV) has been recognized as serious threat to cotton in Indian subcontinent. However, information about cotton–CLCuBuV interaction is still limited. In this study, the level of phenolic compounds, total soluble proteins, and malondialdehyde (MDA) and the activities of phenylalanine ammonia-lyase (PAL), peroxidase (POX), catalase (CAT), proteases, superoxide dismutase (SOD), and polyphenol oxidase (PPO) were studied in leaves of two susceptible (CIM-496 & NIAB-111) and two resistant (Ravi and Co Tiep Khac) cotton genotypes. Disease symptoms were mild in the resistant genotypes but were severe in highly susceptible genotypes. The results showed that phenolic compounds, proteins, PAL, POX, CAT, proteases, SOD, PPO, and MDA play an active role in disease resistance against CLCuBuV. The amount of total phenols, proteases, MDA, and PPO was significantly higher in leaves of CLCuBuV-inoculated plants of both resistant genotypes as in non-inoculated plants, and decreased in CLCuBuV-inoculated plants of both susceptible genotypes over their healthy plants. POX, protein content, SOD, and PAL activities showed lower values in resistant genotypes, while they decreased significantly in susceptible genotypes as compared to the noninoculated plants except PAL, which showed non-significant decrease. CAT was found to be increased in both susceptible and resistant genotypes with maximum percent increase in resistant genotype Ravi, as compared to non-inoculated plants. The results showed significantly higher concentrations of total phenols and higher activity of protease, MDA, SOD, and PPO in resistant genotype Ravi after infection with CLCuBuV, suggesting that there is a correlation between constitutive induced levels of these enzymes and plant resistance that could be considered as biochemical markers for studying plant-virus compatible and incompatible interactions.

Effect of Nitrite Toxicity in Carbohydrate Metabolism to Fresh Water Fish Cirrhinus Mrigala

The aim of the present study was to evaluate about the glucose, glycogen content in liver and muscle in fresh water fish Cirrhinus mrigala exposed to nitrite toxicity. Plasma glucose level of Cirrhinus mrigala exposed to sublethal toxicity (28.31) of nitrite exhibited a significant increase throughout the study period (Table 20 and Fig. 19). The significant increase in plasma glucose level was directly proportional to the exposure period showing a minimum percent increase of 3.69, 5.55, 13.34, 20.53 at the end of 7 th, 14 th , 21 st , 28 th , day and a maximum percent increase of 23.86 at the end of 35 th day. The changes in the liver glycogen content of fish Cirrhinus mrigala exposed to sublethal concentration of nitrite were presented in Table 21 and Fig. 20. The liver glycogen content was gradually increased as the exposure extended showing a percent increase of 1.24, 1.34, 2.04, 3.64 and 3.95 at the end of 7 th , 14 th , 21 st , 28 th , and 35 th days respectively. Table 22 and Fig.21 present the data on changes in the muscle glycogen content of fish Cirrhinus mrigala exposed to sublethal concentration of nitrite for 35 days. During the above treatment period the muscle glycogen content was decreased throughout the study period showing a percent decrease of -7.44, -3.79, -10.37, -16.27, -31.03 at the end of 7 th , 14 th , 21 st , 28 th and 35 th days, respectively.

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Introduction: There are an estimated 390 million dengue virus infections worldwide, 96 million manifesting clinically, resulting in substantial morbidity and mortality in tropical and sub-tropical regions. Infected patients are at risk for dengue hemorrhagic fever and death from plasma leakage, decreased intravascular volume, and shock. Early recognition and proper intravascular volume resuscitation improve morbidity and mortality. The purpose of this study was to evaluate a noninvasive method which could potentially provide a real-time assessment of the risk for shock. Methods: Dengue patients admitted to Queen Sirikit National Institute for Child Health in Bangkok were enrolled in the study. Hematocrits (Hct) were determined at least once daily and the time of maximum Hct was noted. A blood sample was also taken 4–5 days after hospital discharge to assess baseline Hct and determine the maximum percent increase in Hct for each patient. An increase in Hct greater than 20% indicated plasma leakage and an enhanced risk for shock. A noninvasive SmO2 sensor was placed on the upper arm or thigh of the patient and SmO2 data were recorded intermittently during their 2–4 day hospital stay. SmO2 nearest the time of maximum Hct was extracted from the recorded data; only patients who had SmO2 values within 8 hours of the blood measurement were included. SmO2 at the time of maximum Hct was compared between patients with and without significant hemoconcentration using a t-test. Results: There were 11 patients with Hct increase >20% and 17 patients with Hct increase ≤20%. SmO2 was 53 ± 11% for patients with hemoconcentration and 62 ± 10% for those patients without; p=0.03. Conclusions: SmO2 was significantly lower for patients with substantial hemoconcentration in agreement with previous work that showed SmO2 to be a sensitive indicator of hypovolemia. Further work is required to determine if real-time assessment of SmO2 can help direct therapy to minimize the risk for shock in dengue patients.

Magnetism and magnetocaloric effect in multicomponent Laves-phase compounds: Study and comparative analysis

This paper presents a review and results of comparative study of the influence of Gd on some physical properties of (R0.9R′0.1)1−xGdxCo2 solid solutions with R=Dy, Ho and R′=Er, Ho and x varied from 0.05 to 0.15. Powder X-ray diffraction analysis performed at room temperature revealed that all studied solid solutions solidify with the formation of a Laves-phase MgCu2-type structure (space group Fd−3m). The magnetization behavior and the magnetic transition are analyzed in terms of the Landau theory. The studies of magnetic properties and heat capacity showed that a relatively small Gd addition significantly increases TC of the compounds. The maximum percentage increase in TC, namely, ~43% was observed for (Ho0.9Er0.1)1−xGdxCo2. However, the highest temperature was noted for the (Dy0.9Ho0.1)0.85Gd0.15Co2 solid solution; it is TC=183.4K. Below the ordering temperature, all samples are ferrimagnetically ordered; at high temperatures, they are Curie–Weiss paramagnets. Moreover, a small Gd addition eliminates the field-induced magnetic transition near TC and, as consequence, transforms the nature of magnetic transition from the first- to second-order.The magnetocaloric effect has been estimated in terms of both isothermal magnetic entropy and adiabatic temperature changes. The highest adiabatic temperature change ΔTad=3K and highest isothermal entropy change ΔSmag=12.1J/kgK were observed for (Ho0.9Er0.1)0.95Gd0.05Co2 at ~90K in magnetic fields of 2T and 3T, respectively. A decrease in the entropy change has been observed with increasing Gd content in all studied samples. The smallest values of ΔSmag were observed for the (Dy0.9Ho0.1)1−xGdxCo2 solid solutions. Under an external field change of from 0 to 3T, the maximum entropy change for (Dy0.9Ho0.1)1−xGdxCo2 compounds decreases from 6.9at x=0.05–4.3J/kgK at x=0.15. The refrigerant capacity for all solid solutions (with 0.05≤x≤0.15) is reported. The effect of increasing Gd content in the solid solutions on their magnetic and magnetocaloric properties is discussed.

Molecular Simulation of CO2 Adsorption in the Presence of Water in Single-Walled Carbon Nanotubes

The adsorption of carbon dioxide in the presence of water in single-walled carbon nanotubes is studied using Monte Carlo simulation, at 300, 325, and 350 K. We also investigate the influence of the diameter and chirality of the nanotubes on the adsorption isotherms of CO2. It is observed that increasing the nanotube diameter from 1.36 nm (10, 10) to 2.03 nm (15, 15) leads to enhanced CO2 capacity, while change in chirality has little effect on the adsorption capacity of carbon nanotubes. Our results show that the influence of preadsorbed water on CO2 adsorption is dependent on both the effects of excluded volume and H2O–CO2 interactions. The maximum adsorbed amount of CO2 decreases linearly with the loading of water, and drops more rapidly in narrower nanotubes. The structure of water in hydrophobic nanopores is in the form of hydrogen-bonded clusters, and its adsorption does not affect the arrangement and orientation of CO2 molecules (i.e., it does not affect the mechanism of CO2 adsorption). The average size of water clusters coexisting with CO2 depends strongly on the adsorbed amount of CO2; however, it is shown that splitting large water clusters into smaller ones can lead to significant enhancement of CO2 adsorption, due to the resulting stronger water–CO2 interaction. The maximum percentage increase in the excess adsorption of CO2 is as high as 53.4% when a single cluster is split into multiple smaller clusters. This finding demonstrates that the efficiency of CO2 capture from flue gas can be significantly improved by controlling the structure of coexisting water in carbon nanotubes.

Pharmacodynamic stimulation of thrombogenesis by angiotensin (1–7) in recurrent ovarian cancer patients receiving gemcitabine and platinum-based chemotherapy

This randomized, double-blind, placebo-controlled Phase 2 study evaluated safety and efficacy of A(1-7) for reduction in Grade 3-4 thrombocytopenia in patients receiving myelosuppressive chemotherapy. Pharmacodynamic activity of A(1-7) in platelet production and retention of scheduled dose intensity were also determined. Thirty-four patients with ovarian, Fallopian tube, or peritoneal carcinoma receiving gemcitabine and carboplatin or cisplatin were evaluated. Patients were randomized to receive study drug subcutaneously at 100 mcg/kg (n = 11), 300 mcg/kg (n = 13), or placebo (n = 10) following chemotherapy for up to six cycles. Hematologic variables were obtained throughout each treatment cycle. There were no drug-related safety issues. There were no instances of Grade 4 thrombocytopenia in patients who received 100 mcg/kg treatment compared to 6 % of chemotherapy cycles for patients receiving placebo (p = 0.07). The maximal percentage increase in platelet concentration from baseline was higher for patients who received 100 mcg/kg A(1-7) compared to placebo (p = 0.02). This increase was accompanied by a reduction in the nadir absolute neutrophil count (p = 0.04). Relative dose intensity for the combination chemotherapy was higher for patients who received 100 mcg/kg A(1-7) compared to placebo (p = 0.04). There were no differences in outcomes for patients receiving 300 mcg/kg dose compared to placebo. A 100 mcg/kg dose of A(1-7) was shown to produce pharmacodynamic effects on peripheral blood platelet counts, preserve planned dose intensity, and reduce Grade 3-4 thrombocytopenia following gemcitabine and platinum chemotherapy. These findings are consistent with A(1-7)-induced stimulation of thrombogenesis in the bone marrow following marrow-toxic chemotherapy.

Microvascular Effects of Subatmospheric Pressure in Striated Muscle

Topical application of subatmospheric pressure (TASAP) promotes faster wound healing, but tissue effects are not entirely understood. This study investigated microvascular effects of TASAP in striated muscle with the hypothesis being that TASAP elicits arteriolar vasodilation and decreases interstitial accumulation of protein. Rat cremasteric microcirculation was directly examined in two experiments utilizing a novel technique. First, TASAP was applied to the cremaster in three experimental groups and a non-TASAP control group. Arteriolar diameters were directly measured before and after TASAP. In experiment two, intravascular fluorescein isothiocyanate (FITC)-labeled albumin and topical leukotriene B4 (LTB4) were delivered to the cremaster. Microvascular permeability was assessed by measuring the accumulation/disappearance of FITC-albumin in the interstitial tissue. TASAP produced significant arteriolar vasodilation compared with control values. The mean maximum percent increase in diameter with TASAP was 8.70% at -2 kPa (p < 0.05), 7.16% at -4 kPa (p < 0.05), and 10.43% at -6 kPa (p < 0.01). TASAP decreased interstitial FITC-albumin by 26.3% (p < 0.008) following LTB4; the control group showed a steady increase in interstitial FITC-albumin. These results support the hypothesis that TASAP elicits significant arteriolar vasodilation with a subsequent increase in blood flow as well as a decrease in interstitial protein accumulation.

Numerical Simulation of Airfoil Aerodynamic Penalties and Mechanisms in Heavy Rain

Numerical simulations that are conducted on a transport-type airfoil, NACA 64-210, at a Reynolds number of2.6×106and LWC of 25 g/m3explore the aerodynamic penalties and mechanisms that affect airfoil performance in heavy rain conditions. Our simulation results agree well with the experimental data and show significant aerodynamic penalties for the airfoil in heavy rain. The maximum percentage decrease inCLis reached by 13.2% and the maximum percentage increase inCDby 47.6%. Performance degradation in heavy rain at low angles of attack is emulated by an originally creative boundary-layer-tripped technique near the leading edge. Numerical flow visualization technique is used to show premature boundary-layer separation at high angles of attack and the particulate trajectories at various angles of attack. A mathematic model is established to qualitatively study the water film effect on the airfoil geometric changes. All above efforts indicate that two primary mechanisms are accountable for the airfoil aerodynamic penalties. One is to cause premature boundary-layer transition at low AOA and separation at high AOA. The other occurs at times scales consistent with the water film layer, which is thought to alter the airfoil geometry and increase the mass effectively.

Eccentricity effects of microhole arrays on drag reduction efficiency of microchannels with a hydrophobic wall

This paper experimentally investigates the effects of microhole eccentricity on the slip lengths of Stokes flow in microchannels with the bottom wall made of microhole arrays. The wettability of such microhole structures fabricated by the replica molding of polydimethylsiloxane is first analyzed measuring both static and dynamic contact angles. Subsequently, the drag reduction performance of the microchannels with such hydrophobic microhole surfaces is evaluated. The results indicate that the impact of microhole eccentricity on drag reduction performance correlates well with the contact angle hysteresis rather than with the static contact angle. Furthermore, microhole arrays with large normalized width and zero eccentricity show the minimum contact angle hysteresis of 18.7°. In these microchannels, the maximum percentage increase in the relative velocity is 39% corresponding to a slip length of 2.49 μm. For the same normalized width, increasing the normalized eccentricity to 2.6 increases the contact angle hysteresis to 36.5° that eventually reduces the percentage increase in relative velocity and slip length down to 16% and 0.91 μm, respectively. The obtained results are in qualitative agreement with the existing theoretical and numerical models. These findings provide additional insights in the design and fabrication of efficient micropatterned channels for reducing the flow resistance, and leave open questions for theoreticians to further investigate in this field.

Resource and Cost Adjustment in the Design of Allocation Funding Formulas in Public Health Programs

Multiple federal public health programs use funding formulas to allocate funds to states. To characterize the effects of adjusting formula-based allocations for differences among states in the cost of implementing programs, the potential for generating in-state resources, and income disparities, which might be associated with disease risk. Fifty US states and the District of Columbia. Formula-based funding allocations to states for 4 representative federal public health programs were adjusted using indicators of cost (average salaries), potential within-state revenues (per-capita income, the Federal Medical Assistance Percentage, per-capita aggregate home values), and income disparities (Theil index). Percentage of allocation shifted by adjustment, the number of states and the percentage of US population living in states with a more than 20% increase or decrease in funding, maximum percentage increase or decrease in funding. Each adjustor had a comparable impact on allocations across the 4 program allocations examined. Approximately 2% to 8% of total allocations were shifted, with adjustments for variations in income disparity and housing values having the least and greatest effects, respectively. The salary cost and per-capita income adjustors were inversely correlated and had offsetting effects on allocations. With the exception of the housing values adjustment, fewer than 10 states had more than 20% increases or decreases in allocations, and less than 10% of the US population lived in such states. Selection of adjustors for formula-based funding allocations should consider the impacts of different adjustments, correlations between adjustors and other data elements in funding formulas, and the relationship of formula inputs to program objectives.

2132 IMPACT OF RENAL TRANSPLANT ON VASCULOGENIC AND NEUROGENIC DETERMINANTS OF ERECTILE DYSFUNCTION IN PATIENTS WITH CHRONIC RENAL FAILURE

You have accessJournal of UrologyTransplantation & Vascular Surgery: Renal Transplantation, Vascular Surgery I1 Apr 20122132 IMPACT OF RENAL TRANSPLANT ON VASCULOGENIC AND NEUROGENIC DETERMINANTS OF ERECTILE DYSFUNCTION IN PATIENTS WITH CHRONIC RENAL FAILURE Bhuvanesh Nanjappa, Shrawan Kumar Singh, Ravimohan Mavuduru, Manish Modi, Mukut Minz, Arup Kumar Mandal, and Vinay Sakhuja Bhuvanesh NanjappaBhuvanesh Nanjappa Chandigarh, India More articles by this author , Shrawan Kumar SinghShrawan Kumar Singh Chandigarh, India More articles by this author , Ravimohan MavuduruRavimohan Mavuduru Chandigarh, India More articles by this author , Manish ModiManish Modi Chandigarh, India More articles by this author , Mukut MinzMukut Minz Chandigarh, India More articles by this author , Arup Kumar MandalArup Kumar Mandal Chandigarh, India More articles by this author , and Vinay SakhujaVinay Sakhuja Chandigarh, India More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2012.02.2302AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Erectile dysfunction (ED) is common in chronic renal failure, it has multifactorial causes which may get reverse following transplantation. Present study was conducted to assess endothelial dysfunction by flow mediated dilatation (FMD) and neuropathy by sympathetic skin response (SSR) and nerve conduction studies (NCS) in uremics before and after renal transplantation. METHODS Patients awaiting transplantation were subjected to history, clinical evaluation, IIEF-5 questionnaires. SSR and NCS were assessed using Nicolet Biomedical EA-4. FMD of brachial artery estimated using high resolution ultrasound after occluding brachial artery for 5 minutes, expressed as maximum percentage increase in diameter. Patients were evaluated again for above parameters, 3 months after successful transplantation. The statistical analysis was performed by paired 't' test and Pearson coefficient of correlation. RESULTS Total 171 male patients underwent renal transplantation during the study period. Thirty nine patients with diabetes mellitus, four with graft dysfunction and one with multiple myeloma were excluded from the study. Data of remaining 127 patients were analyzed. Prevalence of ED before and after transplantation was 75.6% and 55.9% respectively (p < 0.001). Serum testosterone levels, FMD and IIEF scores improved significantly (8.05±1.70 to 9.43±2.16, p < 0.000), (12.61±6.15% vs 20.10±8.60, p<0.000 and 17.47±4.30 vs. 19.26±4.41, p<0.000). IIEF scores correlated significantly with age (r= −0.298, p<0.001), FMD (r=444, p<0.000) & cholesterol (r=−0.178, p<0.045). FMD correlated negatively with age (r=−0.284, p<0.001). There was no significant difference in IIEF score with respect to the type of renal arterial anastomosis (Internal iliac 19.78±4.52 vs. External iliac 18.79±4.28; p=0.984). SSR and NCS were abnormal in 20 and 28 patients before and 9 and 8 patients after transplantation, respectively. IIEF and FMD were significantly low in patients with abnormal NCS and SSR. CONCLUSIONS Prevalence of ED is high in uremics and improves following transplantation. The improvement is associated with improvement in vasculogenic and neurogenic determinants of erectile function. A substantial number of them still may continue to have ED. It may improve with passage of time in patients with normal graft function. However, it requires further study with longer follow-up. © 2012 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetailsCited byPyrgidis N, Mykoniatis I, Sokolakis I, Minopoulou I, Nigdelis M, Sountoulides P, Verze P, Hatzichristodoulou G and Hatzichristou D (2020) Renal Transplantation Improves Erectile Function in Patients with End-Stage Renal Disease: A Systematic Review and Meta-AnalysisJournal of Urology, VOL. 205, NO. 4, (1009-1017), Online publication date: 1-Apr-2021. Volume 187Issue 4SApril 2012Page: e861 Advertisement Copyright & Permissions© 2012 by American Urological Association Education and Research, Inc.MetricsAuthor Information Bhuvanesh Nanjappa Chandigarh, India More articles by this author Shrawan Kumar Singh Chandigarh, India More articles by this author Ravimohan Mavuduru Chandigarh, India More articles by this author Manish Modi Chandigarh, India More articles by this author Mukut Minz Chandigarh, India More articles by this author Arup Kumar Mandal Chandigarh, India More articles by this author Vinay Sakhuja Chandigarh, India More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...