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The Humpback whale tubercles have been studied for more than a decade. Tubercle Leading Edge (TLE) effectively reduces the separation bubble size and helps in delaying stall. They are very effective in case of low Reynolds number flows. The current Computational Fluid Dynamics (CFD) study is on NACA 4415 airfoil, at a Reynolds number 120,000. Two TLE shapes are tested on NACA 4415 airfoil. The tubercle designs implemented on the airfoil are sinusoidal and spherical. A parametric study is also carried out considering three amplitudes (0.025c, 0.05c and 0.075c), the wavelength (0.25c) is fixed. Structured mesh is utilized to generate grid and Transition SST turbulence model is used to capture the flow physics. Results clearly show spherical tubercles outperform sinusoidal tubercles. Furthermore experimental study considering spherical TLE is carried out at Reynolds number 200,000. The experimental results show that spherical TLE improve performance compared to clean airfoil.

NACA 0015 and NACA 4415 aerofoil are most common four digits and broadly used aerodynamic shape. Both of the shapes are extensively used for various kind of applications including turbine blade, aircraft wing and so on. NACA 0015 is symmetrical and NACA 4415 is unsymmetrical in shape. Consequently, they have big one-of-a-kind in aerodynamic traits at the side of widespread differences of their utility and performance. Both of them undergo the same fluid principle while applied in any fluid medium giving dissimilar outcomes in aerodynamics behavior. On this work, experimental and numerical investigation of each NACA 0015 and NACA 4415 is done to decide their performance. For this purpose, aerofoil section is tested for a prevalence range attack of angle (AOA). The study addresses the performance of NACA 0015 and NACA 4415 and evaluates the dynamics of flow separation, lift, drag, pressure and velocity contour and so on. This additionally enables to layout new optimistic aerofoil, which is critical to enhance the efficiency and performance of an aircraft in terms of lift enhancement and drag reduction.

Objectives: In this work Rapid prototype model is used to reduce the noise of an axial cooling fan. Methods/Analysis: Reverse engineering is considered for modeling the fan and computational fluid dynamics methods are applied to the existing fan to evaluate the noise levels. Changed the existed axial fan blade profile with NACA 63-006 airfoil to decrease noise levels. The local flow field of the fan was computed with rapid prototype model. The flow patterns throughout the fan are visualized using numerical techniques. Findings: By decreasing the no. of blades with airfoil cross section, noise is reduced and also increased fan performance. The overall sound intensity levels are observed for modified fan a series of NACA Airfoil and it has been observed that the minimum noise level of NACA 63-006 RPT fan is 60.5 dB. Novelty/ Improvement: Large broadband noise reduction is obtained due to RPT fan a NACA 63-006 airfoil profile of blade geometry.

The ability of active flow control through synthetic jet actuator to reattach the stalled flow on a NACA 0025 at low Reynolds number was investigated experimentally. Wind tunnel tests were performed where boundary layer velocity profiles were measured by hot-wire anemometry. The effects of excitation frequency and momentum input, quantified by the blowing ratio were the focus of the measurements. Using both low- and high-frequency actuation, the boundary layer was reattached in a time-averaged sense, however the mechanism of control was not the same. Low-frequency excitation lead to oscillations in the boundary layer at the control frequency due to the passage of a vortex transporting high-momentum to the inner boundary layer. Conversely, high-frequency control caused a steady reattachment of the boundary layer.

Leading-edge protuberances on airfoils or wings have been considered as a viable passive control method for flow separation. In this paper, the aerodynamic performance of a modified airfoil with a single leading-edge protuberance was investigated and compared with the baseline NACA 634-021 airfoil. Spalart–Allmaras turbulence model was applied for the numerical simulation. Compared to the sharp decline of baseline lift coefficient, the stall angle of the modified foil decreased and the decline of the lift coefficient became mild. The poststall performance of the modified airfoil was improved, while the prestall performance was declined. Asymmetric flows along the spanwise direction were observed on the modified airfoil, and the local region around one shoulder of the protuberance suffered from leading-edge separation at prestall angles of attack, which may be responsible for the performance decline. At poststall angles of attack, the attached flows along the peak of the protuberance with a sideward velocity component would help improving the total performance of the airfoil. Experimental visualization methods, including surface tuft and smoke flow, were performed, and the asymmetric flow pattern past the protuberance was successfully captured. This specific phenomenon may be largely related to the formation of the biperiodic condition and other complicated flow patterns induced by multiple leading-edge protuberances. The formation mechanism and suppression method of the symmetry breaking phenomenon should be investigated more deeply in the future to guide the practical application of this passive control method.

Contrast-induced nephropathy (CIN) is a leading cause of hospital-acquired acute kidney injury (AKI) due to apoptosis induced in renal tubular cells. Our previous study demonstrated the novel N-acetylcysteine amide (NACA); the amide form of N-acetyl cysteine (NAC) prevented renal tubular cells from contrast-induced apoptosis through inhibiting p38 MAPK pathway in vitro. In the present study, we aimed to compare the efficacies of NACA and NAC in preventing CIN in a well-established rat model and investigate whether thioredoxin-1 (Trx1) and apoptosis signal-regulating kinase 1 (ASK1) act as the potential activator for p38 MAPK. NACA significantly attenuated elevations of serum creatinine, blood urea nitrogen, and biomarkers of AKI. At equimolar concentration, NACA was more effective than NAC in reducing histological changes of renal tubular injuries. NACA attenuated activation of p38 MAPK signal, reduced oxidative stress, and diminished apoptosis. Furthermore, we demonstrated that contrast exposure resulted in Trx1 downregulation and increased ASK1/p38 MAPK phosphorylation, which could be reversed by NACA and NAC. To our knowledge, this is the first report that Trx1 and ASK1 are involved in CIN. Our study highlights a renal protective role of NACA against CIN through modulating Trx1 and ASK1/p38 MAPK pathway to result in the inhibition of apoptosis among renal cells.

A 2D CFD modelof a modified turbine blade was investigated numerically in this work. The turbine utilized NACA 0018 which had airfoil chord length of 0.75 m and operated at Reynolds number (Re) of 1.07 × 106. The model was simulated using OpenFoam with steady solver named simpleFoam. The aim of airfoil modification was to gain more power by increasing turbine lift force. The increase of lift force was obtained by truncating the trailing edge at 15 % chord length. The investigation of single normal and blunt were conducted prior to evaluation of turbine power. Some CFD simulation parameters were evaluated in the normal single NACA 0018 model and the best parameter combination were decided to resolve the physical turbulence phenomena and the fluid airfoil interaction. The best parameters was chosen by validating the simulation result to some reference data and then assigned to a CFD model of blunt NACA 0018. From the simulation result, it was found that the blunt NACA 0018 had 15.83 % higher lift coefficient than the normal and the turbine power was increase significantly when use blunt airfoil.

Importance of Small Wind Turbines (SWTs) for harnessing wind energy in the context of India is stated. Relevance of vertical axis wind turbine (VAWT) in the small wind is explained. In the present work, a three bladed Small Vertical Axis Wind Turbine (SVAWT) has been designed, manufactured and tested. Three NACA profile blades, namely NACA 0012, NACA 0015 and NACA 0018 were used to conduct the experiment. The blades, link rod, rotor, stator and column can be manufactured with the engineering facilities available even at sub-district (Tehsil) levels. The shaft hub assembly of the conventional system is replaced by the bicycle rear wheel hub shaft, which is easily available in the market, to make it cost effective. The blade parameters have been taken into consideration during the design stage. Experiment has been performed to find the torque - speed characteristics of the SVAWT. Comparison of various parameters has been made for the three types of NACA profiles for the wind conditions of Kota, Rajasthan, India.

One of the most important factors for cost-effective SB-VAWT product is the selection of an appropriate airfoil to achieve desired aerodynamic performance and to optimise the overall dimensions of the SB-VAWT. Design changes related to airfoil also have the potential for increasing the cost effectiveness of SB-VAWTs. This research aims to perform a detailed performance analysis on a series of low Reynolds number (RN) airfoils selected to enhance the performance of smaller capacity fixed-pitch SB-VAWT. Three low RN airfoils have been selected as candidates for the blades of a smaller-capacity SB-VAWT. The research compares their performances with that of a conventionally used symmetric NACA 0015 airfoil. It was found that all candidate low RN airfoils produced higher torque than the NACA 0015 at lower tip speed ratios.

The purpose of this study was to explore the effects of wind speed, airfoil thickness and setting angle of blades on the output performance of a VAWT system. Three shapes of the blades as NACA6422, NACA6412, and NACA6404 were fabricated and installed in the support mechanism to test the effect of airfoil thickness on the output performance. Results indicated that the section shape of blade with a cambered NACA 64XX series is prior to the ordinary symmetric NACA0022 series used in VAWT systems. The statistic analysis showed that the contribution of setting angle on the output performance is 12.27%, which is higher than that of thickness of airfoil as 2.93% when the extra load was applied on the VAWT system during tests. For application of VAWT systems in the densely populated urban areas, it is suggested that the blades with cambered airfoil of NACA6422 is suitable for electrical power generation.

Methamphetamine (METH), a highly addictive drug used worldwide, induces oxidative stress in various animal organs. Recent animal studies indicate that methamphetamine also induces oxidative stress in the retina, which is an embryonic extension of the forebrain. The aim of this study, therefore, was to evaluate the protecttive effects of N-acetylcysteine amide (NACA) against oxidative stress induced by METH in retinal pigment epithelium (RPE) cells. Our studies showed that NACA protected against METH-induced oxidative stress in retinal pigment epithelial cells. Although METH significantly decreased glutathione (GSH) levels and increased reactive oxygen species (ROS) and malondialdehyde (MDA) levels, these returned to control levels with NACA treatment. Overall observations indicated that NACA protected RPE cells against oxidative cell damage and death by inhibiting lipid peroxidation, scavenging ROS, increasing levels of intracellular GSH, and maintaining the antioxidant enzyme activity and the integrity of the bloodretinal barrier (BRB). The effectiveness of NACA should be further evaluated to determine its potential for the treatment of numerous retinal diseases caused by oxidative stress.

Using split cardiac Na+/Ca2+exchangers (NCX1), we previously demonstrated that phospholemman (PLM) regulates NCX1 by interacting with the proximal linker domain (residues 218–358) of the intracellular loop of NCX1. With the use of overlapping loop deletion mutants, interaction sites are localized to two regions spanning residues 238–270 and residues 300–328 of NCX1. In this study, we used alanine (Ala) linker scanning to pinpoint the residues in the proximal linker domain involved in regulation of NCX1 by PLM. Transfection of human embryonic kidney (HEK)293 cells with wild-type (WT) NCX1 or its Ala mutants but not empty vector resulted in NCX1 current ( INaCa). Coexpression of PLM with WT NCX1 inhibited INaCa. Mutating residues 248–252 (PASKT) or 300–304 (QKHPD) in WT NCX1 to Ala resulted in loss of inhibition of INaCaby PLM. By contrast, inhibition of INaCaby PLM was preserved when residues 238–242, 243–247, 253–257, 258–262, 263–267, 305–309, 310–314, 315–319, 320–324, or 325–329 were mutated to Ala. While mutating residue 301 to alanine completely abolished PLM inhibition, mutation of any single residue 250–252, 300, or 302–304 resulted in partial reduction in inhibition. Mutating residues 248–252 to Ala resulted in significantly weaker association with PLM. The NCX1-G503P mutant that lacks Ca2+-dependent activation retained its sensitivity to PLM. We conclude that residues 248–252 and 300–304 in the proximal linker domain of NCX1 were involved in its inhibition by PLM.

To compare a commercial contrast agent (CA) Dotarem and a necrosis-avid CA (NACA) for their ability to evaluate the therapeutic necrosis with a vascular disrupting agent (VDA) on magnetic resonance imaging in rodent liver tumors to determine which could better correlate with the histopathologic outcome.: After the VDA treatment, 16 rats with 32 liver rhabdomyosarcomas were randomized into Dotarem and NACA groups (n = 8 per group) for both interindividual and intraindividual comparisons. T2-weighted imaging, T1-weighted imaging (T1WI), contrast-enhanced T1-weighted imaging (CE-T1WI), and diffusion-weighted imaging were performed at baseline, after VDA treatment and CA injections. The enhancing efficacy of CAs at immediate and delayed enhancement on CE-T1WI in viable tumor and necrosis was compared. Tumor necrosis ratios calculated from NACA and Dotarem were compared and correlated with gold-standard histopathology.: On the immediate CE-T1WI, viable tumor was enhanced by either CA. On the delayed CE-T1WI at 30 minutes, both CAs failed to demarcate viable tumor from necrosis. At 24 hours post-NACA, the necrosis was clearly distinguished from viable tumor and thus derived necrosis ratio matched that from histopathology (P = 0.99); necrosis ratio from Dotarem was significantly lower than that from NACA and histopathology (P0.05, both), with a higher correlation of NACA than that of Dotarem with histopathology (r = 0.99 vs. r = 0.82).: NACA better evaluated VDA-induced tumor necrosis than nonspecific CA on T1WI in tumor models of rat liver. NACA showed a closer correlation with histopathology than nonspecific CA for the delineation of true necrosis. Delayed enhancement on T1WI with nonspecific CA is not suitable for the assessment of VDA-induced tumor necrosis.

The ·OH and ·OOH radical scavenging activity of N-acetylcysteine amide (NACA) has been studied using density functional theory, specifically the M05-2X functional. All possible reaction sites have been considered, and the branching ratios have been estimated. The efficiency of different mechanisms of reaction has been evaluated, and it has been concluded that NACA reacts exclusively by hydrogen atom transfer (HAT). The overall reactivity of NACA toward OH radicals is proposed to be diffusion-controlled in both non-polar and polar media. The values of the overall rate coefficients are 3.80 × 109 and 1.36 × 109 L mol−1 s−1 for benzene and aqueous solutions, respectively. The reactivity of NACA toward ·OOH, on the other hand, is much lower but still higher than those of melatonin and caffeine. HAT from the –SH site is proposed to be the channel accounting for most of the radical scavenging activity of NACA in aqueous solution. In non-polar environments, two channels of reaction were found to similarly contribute to the overall reactivity of NACA toward OH radicals. They are those corresponding to hydrogen atom transfer from –CH2 and –SH sites.

Oxidative stress plays a critical role in accelerating retinal pigment epithelial dysfunction and death in degenerative retinal diseases, including age-related macular degeneration. Given the key role of oxidative stress–induced retinal pigment epithelial cell death and secondary photoreceptor loss in the pathogenesis of age-related macular degeneration, we hypothesized that a novel thiol antioxidant, N-acetylcysteine amide (NACA), might ameliorate cellular damage and subsequent loss of vision. Treatment of human retinal pigment epithelial cells with NACA protected against oxidative stress–induced cellular injury and death. NACA acted mechanistically by scavenging existing reactive oxygen species while halting production of reactive oxygen species by reversing lipid peroxidation. Furthermore, NACA functioned by increasing the levels of reduced glutathione and the phase II detoxification enzyme glutathione peroxidase. Treatment of mice exposed to phototoxic doses of light with NACA maintained retinal pigment epithelial cell integrity and prevented outer nuclear layer cell death as examined by histopathologic methods and rescued photoreceptor function as measured by electroretinography. These observations indicate that NACA protects against oxidative stress–induced retinal pigment epithelial and photoreceptor cell death in vitro and in vivo. The data suggest that NACA may be a novel treatment in rescuing retinal function and preventing vision loss secondary to retinal degenerative diseases, including age-related macular degeneration.

The effects of N-acetylcysteine amide (NACA), a free radical scavenger, on cataract development were evaluated in Wistar rat pups. Cataract formation was induced in these animals with an intraperitoneal injection of a glutathione (GSH) synthesis inhibitor, l-buthionine-(S,R)-sulfoximine (BSO). To assess whether NACA has a significant impact on BSO-induced cataracts, the rats were divided into four groups: (1) control, (2) BSO only, (3) NACA only, and (4) NACA+BSO. The control group received only saline ip injections on postpartum day 3, the BSO-only group was given ip injections of BSO (4mmol/kg body wt), the NACA-only group received ip injections of only NACA (250mg/kg body wt), and the NACA+BSO group was given a dose of NACA 30min before administration of the BSO injection. The pups were sacrificed on postpartum day 15, after examination under a slit-lamp microscope. Their lenses were analyzed for selective oxidative stress parameters, including glutathione (reduced and oxidized), protein carbonyls, catalase, glutathione peroxidase, glutathione reductase, and malondialdehyde. The lenses of pups in both the control and the NACA-only groups were clear, whereas all pups within the BSO-only group developed well-defined cataracts. It was found that supplemental NACA injections during BSO treatment prevented cataract formation in most of the rat pups in the NACA+BSO group. Only 20% of these pups developed cataracts, and the rest retained clear lenses. Further, GSH levels were significantly decreased in the BSO-only treated group, but rats that received NACA injections during BSO treatment had these levels of GSH replenished. Our findings indicate that NACA inhibits cataract formation by limiting protein carbonylation, lipid peroxidation, and redox system components, as well as replenishing antioxidant enzymes.

Mixed cationic Ca2+/Na+(Mg2+) polyphosphates, regarded as potential biocomposite fillers, were fabricated by solid-state reactions. Most of them demonstrated low solubility (assessed also by the Glasser and Jenkins approach) from 1 ± 0.2 g/L for Ca(PO3)2 to 5 ± 0.4 g/L for NaCa(PO3)3 and 50 ± 2 g/L for soluble phase of NaPO3. Liquid-state NMR of the soluble part of polyphosphates gave the degree of polymerization of their chains ranging from 10 to 30 for NaCa(PO3)3 and ca. 1000 monomeric units for NaPO3.

BackgroundObjectification of the spread of National Advisory Committee for Aeronautics (NACA) scoring system for selected homogeneous groups based on retrospective data, and diagnosis and analysis of the influence of a given validatation date to the valuation accuracy based on prospective data.Material and MethodsRecords of emergency operations from the data pool of the NACA-X database of emergency medical systems (EMS) Innsbruck and surroundings with a retrospective study period over 6 years and a prospective study period of 9 months with the possibility to record the NACA score on three different time points.ResultsAll diagnostic groups with 2596 records show a striking retrospective dispersion in the NACA evaluation. Prospectively “hypoglycemia” (n=31) and “intoxication” (n=93) show a highly (p

This paper describes the effect of some design parameters on the performance of a Giromill vertical axis wind turbine. A Giromill wind turbine has been designed, manufactured and tested. The turbine performance has been investigated with varying the design parameters such as, pitch angle, number of blades, airfoil type, turbine radius and its chord length. Then, the results were used for the comparison between the performance achieved while changing the design parameters. Vast number of experiments have been performed with changing the above mentioned parameters. The effect of each parameter on the power coefficient and torque coefficient has been studied and explanation of the results was also discussed. It has been found that the pitch angle, turbine radius and chord length have a significant effect on turbine power coefficient. The maximum power coefficient obtained in this research was 25% using turbine radius of 40 cm, chord length 15 cm, pitch angle of 10°, airfoil type NACA 0024, and four blades (which is found to be the best configuration in this study). For the effect of pitch angle, the obtained maximum power coefficient is decreasing, this decrease in performance was due to increasing in the pitch angle above 10° and also due to decreasing it below this value showing the high effect of pitch angle. It was also noticed that, when decreasing the turbine radius to 20 cm at 0° pitch angle the maximum power coefficient is much decreased. Moreover, decreasing the chord length to 12 cm at 10° pitch angle decreases the maximum power coefficient significantly, which again show the high effect of turbine radius and chord length. In order to compare the effect of airfoil type; the blades with NACA 4420 were used compared to NACA 0024 at the same above parameters of turbine radius 40 cm, chord length 15 cm, pitch angle of 10° and four blades. The maximum power coefficient obtained was 15%. Finally, the effect of the number of blades have been investigated using two, three and four blades at 0° pitch angle and the same other above parameters of turbine radius 40 cm, chord length 15 cm and airfoil type NACA 0024. The obtained maximum power coefficients were decreased significantly when decreasing the number of blades from four to two blades.

Simulations of the aerodynamics performance of NACA 4312 airfoil at various gurney flap angles and incoming airspeed (wind velocities) have been conducted. The gurney flap's size was set at 5.0% length of the chord line. Two airfoil models with gurney flap at 45° and 90° were simulated and compared with the results of plain airfoil (without gurney flap) model with the incoming airspeed of 10.0 m/s, 70.0 m/s and 200.0 m/s. The results have shown that increasing the value of gurney flap angle to 45° and 90° will increase the lifting force of the airfoil and decrease the drag force.

An increased risk of HIV-1 associated dementia (HAD) has been observed in patients abusing methamphetamine (METH). Since both HIV viral proteins (gp120, Tat) and METH induce oxidative stress, drug abusing patients are at a greater risk of oxidative stress-induced damage. The objective of this study was to determine if N-acetylcysteine amide (NACA) protects the blood brain barrier (BBB) from oxidative stress-induced damage in animals exposed to gp120, Tat and METH. To study this, CD-1 mice pre-treated with NACA/saline, received injections of gp120, Tat, gp120 + Tat or saline for 5 days, followed by three injections of METH/saline on the fifth day, and sacrificed 24 h after the final injection. Various oxidative stress parameters were measured, and animals treated with gp120 + Tat + Meth were found to be the most challenged group, as indicated by their GSH and MDA levels. Treatment with NACA significantly rescued the animals from oxidative stress. Further, NACA-treated animals had significantly higher expression of TJ proteins and BBB permeability as compared to the group treated with gp120 + Tat + METH alone, indicating that NACA can protect the BBB from oxidative stress-induced damage in gp120, Tat and METH exposed animals, and thus could be a viable therapeutic option for patients with HAD.

The objective of this article is to formulate numerical models for two-dimensional potential flow over the NACA 4412 Airfoil using linear vortex panel methods. By satisfying the no penetration boundary condition and Kutta condition, the circulation density on each boundary points (end point of every panel) are obtained and according to which, surface pressure distribution and lift coefficients of the airfoil are predicted and validated by Xfoil, an interactive program for the design and analysis of airfoil. The sensitivity of results to the number of panels is also investigated in the end, which shows that the results are sensitive to the number of panels when panel number ranges from 10 to 160. With the increasing panel number (N>160), the results become relatively insensitive to it.

Level-flightperformancetestswereconductedonatypicallightgeneralaviationsingle-engineretractableaircraft with partially and fully extended partial-span single-slotted flaps in both gear-up and gear-extended configurations. A parabolic variation in the aircraft equivalent parasite drag area with flap deflection was observed for both configurations.Alinearrelationwasdiscovered betweentheaircraft equivalentparasitedragareaandthesquareof the flapdeflection anglefor both configurations.This result suggests thatlevel-flight performance tests in thestowed and fully extended flap configurations will yield adequate data for estimating performance for intermediate flap deflections. A similar linear relation was confirmed for an NACA 23012 airfoil equipped with a single-slotted flat using classical NACA wind-tunnel data. The flight tests showed that the aircraft equivalent parasite drag area increased by a factor of 1.16 at 10, by 1.81 at 20, and by 3.14 at a full flap deflection of 32 in the gear-up configuration. With the gear extended, the equivalent parasite drag area increased by a factor of 1.14 at 10, by 1.29 at 20, and by 1.67 at the 32 full flap deflection. The results are expected to be typical for similar aircraft.

This report is using the finite element analysis method to investigate the performance of an airfoil (NACA 0100-35), which uses 2D computational fluid dynamics simulations based on ANSYS to find the lift and drag coefficients under different conditions. The boundary conditions are defined as follows: The density is 1kg/m3, gauge pressure is 0, and airflow velocity is 50m/s. Also the Reynolds number is considered during the simulation. As a result, the simulation shows the stalling points and efficiencies of the airfoil under different angles of attack. The simulation also plots the contours and stream lines in these conditions.

This paper discusses the performance of three blade vertical axis wind turbine. 2D computational flow analysis is carried out for different rotational speeds of the blades in a plane normal to wind turbine axis. It is implied that turbine blades have infinite aspect ratio. The selection is done based on the lift and drags generated by the various NACA series airfoil (NACA 0012, NACA 0015, NACA 0018, and NACA 0021) at a different angle of attacks, among them NACA 0015 airfoil is found to be most suitable one. A triangular meshed geometry is created and computational fluid dynamics (CFD) simulation is carried out. The computational analysis is performed at various speeds of VAWT blade rotation where the position of the airfoil is made with respect to the wind. Torques generated at different blade positions in a VAWT and the forces by the turbine over one full complete cycle were studied.

Introduction: Ice-climbing is widely considered to be a hazardous sport with a high risk of injury. To date, there has been no scientific analysis to characterize and reveal the prevalence of injury in this sport. The purpose of this study was to quantify and rate ice-climbing injuries. Methods: Eighty-eight ice-climbers (water ice) (13 female, 75 male, mean age 34.6 years) from nine countries completed a comprehensive questionnaire on ice-climbing accidents and injuries, climbing frequency and risk taking behaviour. Iceclimbing hours were quantified and injuries rated according to the NACA (National Advisory Committee for Aeronautics) score. To enable comparison to other sports, the injury risk was calculated per 1000 hours of participation in a given sport. Results: Seventeen athletes (19%) reported a total of 35 overuse syndromes resulting from ice-climbing. Ninety-five injuries were retrospectively reported for a consecutive 3-year period. The incidence and respective grading of the acute injuries were: 67 for NACA 1, 24 for NACA 2, and 4 for NACA 3. Most acute injuries were open wounds (55.2%) and haematomas (21.9%). These injuries occurred 61.3% of the time while lead climbing, 23.8% while following and the rest during belaying, approach or return. The incidence of overuse injury syndromes was 0.77/1000 hours of sports participation. The injury incidence was 4.07/1000hr for NACA 1-3 with 2.87/1000hr in NACA 1, and none in NACA 4-7. Body mass index (BMI) correlated significantly (P

We retrospectively assessed the survival benefit of novel anticancer agents (NACA) after volume-reduction surgery for far-advanced gastric cancer (FAGC). From 1995 to 2005, 41 patients with FAGC underwent chemotherapy after volume-reduction surgery. Those treated since 2000 who received NACA were referred to as group A, and those treated before 2000, who received anticancer agents other than NACA, were referred to as group B. In addition, 21 patients with unresectable gastric cancer treated since 2000 who received NACA were referred to as group C. We investigated the significance of volume-reduction surgery during treatment with NACA. The median survival time (MST) was significantly prolonged in group A (626 days) compared to group B (364 days; P = 0.0156). Multivariate analysis showed that having one noncurative factor (NCF), and the use of NACA, were factors that contributed to survival time. Comparison between the subgroup of group A that had one NCF and the subgroup that had two or more NCFs revealed MSTs of 700 days and 180 days, respectively, with a significantly longer MST among the patients with one NCF (P = 0.0021). In addition, no difference from the MST of 333 days in group C was seen among the group A patients with two or more NCFs. The postoperative survival time of patients with one NCF was prolonged by the advent of NACA, but no significant prolongation was observed in the patients with two or more NCFs.

Myofibrillogenesis, the precise assembly of sarcomeric proteins into the highly organized sarcomeres, is essential for muscle cell differentiation and function. Myofibrillogenesis requires proper folding and assembly of newly synthesized sarcomeric proteins. sknac (skeletal naca) is an alternatively spliced isoform of naca, which encodes the nascent polypeptide-associated complex alpha polypeptide that binds to newly synthesized polypeptides emerging from the ribosome. sknac is specifically expressed in skeletal and cardiac muscles. However, little is known about the function of skNAC in muscle development in vivo. To determine skNAC function, we have isolated and characterized the sknac gene from zebrafish. Zebrafish sknac cDNA differs from naca by containing an extra large exon that encodes 815 aa. Knockdown of sknac expression by antisense oligos resulted in zebrafish embryos with skeletal muscle defects. The sknac-knockdown embryos showed a paralyzed phenotype with little muscle contraction. In contrast, injection of a control oligo had no effect. Immunostaining and histological analyses revealed that sknac-knockdown embryos contained disorganized thick and thin filaments. Western blot analysis revealed that myosin protein levels were significantly reduced. Collectively, these results demonstrate that skNAC plays a vital role in myofibril assembly and function during muscle cell differentiation.

The entrepreneurial space industry today faces challenges similar to those facing the commercial aircraft industry in the early part of the last century. At that time the National Advisory Committee for Aeronautics (NACA) helped develop many of the key technologies that enabled air travel to become effective, economical and safe. Today, in discussing how best to support the realization of a commercial space economy, we suggest revisiting what an NACA-style organization can contribute. This paper outlines the key concepts that made the NACA so successful: a committee structure, open source publication, a willingness to try any useful experimental method, and a focus on problem definition.

The antioxidant potential of N-acetylcysteine amide (NACA), also known as AD4, was assessed by employing different in vitro assays. These included reducing power, free radical scavenging capacities, peroxidation inhibiting activity through linoleic acid emulsion system and metal chelating capacity, as compared to NAC and three widely used antioxidants, alpha-tocopherol, ascorbic acid and butylated hydroxytoluene (BHT). Of the antioxidant properties that were investigated, NACA was shown to possess higher 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) radical scavenging ability and reducing power than NAC, at all the concentrations, whereas the scavenging ability of H(2)O(2) differed with concentration. While NACA had greater H(2)O(2) scavenging capacity at the highest concentration, NAC was better than NACA at lower concentrations. NAC and NACA had a 60% and 55% higher ability to prevent beta-carotene bleaching, respectively, as compared to control. The chelating activity of NACA was more than 50% that of the metal chelating capacity of EDTA and four and nine times that of BHT and alpha-tocopherol, respectively. When compared to NACA and NAC; alpha-tocopherol had higher DPPH scavenging abilities and BHT and alpha-tocopherol had better beta-carotene bleaching power. These findings provide evidence that the novel antioxidant, NACA, has indeed enhanced the antioxidant properties of NAC.

In this computational work, the influence of a delta wing vortex generator on the boundary layer that develops upstream of a submerged air intake is studied. The state-of-the-art analysis and design of these intakes is discussed in detail. The flow in a conventional NACA inlet is analyzed numerically and its results are considered as a reference for the cases in which the vortex generator is included. A delta wing vortex generator is designed and mounted to the conventional NACA inlet, and the result of this configuration is studied through parametric variations of the vortex generator geometry. Finally, a support mast of the vortex generator is designed and included in the model, and simulations are performed for the configuration NACA inlet with vortex generator and mast. Three sideslip angles are considered for the mast. The results show that the use of the delta wing vortex generator is responsible for considerable reductions of the boundary-layer thickness and, consequently, significant improvements of the performance parameters of the NACA inlet. The improvements relative to the conventional NACA intake in terms of ram-recovery ratio and mass flow rate are of up to 53 and 19%, respectively.

The self-noise of NACA 0012 and NACA 0021 airfoils are recorded at a Reynolds numbers of 96,000 in an anechoic wind tunnel at an angle-of-attack range of \(-5^\circ \)–\(40^\circ \). Results suggest that the low angle-of-attack tonal noise of the airfoils behaves differently, with the NACA 0021 producing tones at much higher angles-of-attack but not near \(0^\circ \). Noise generated at the onset of stall is subtlely different, with signature of the NACA 0012 forming over a larger angular range compared to the NACA 0021 where the stall signature forms suddenly.

Inflammatory explosion and oxidative stress are important mechanisms of injury in acute necrotizing pancreatitis (ANP). This study investigated the effects of N-acetylcysteine amid (NACA), a novel cell-permeant antioxidant with anti-inflammatory activity, on experimental ANP in rats.Fifty-two adult male Sprague-Dawley rats were used, and ANP was induced by cerulein. The animals were divided into four groups which were sham + saline, sham + NACA, ANP + saline, and ANP + NACA. NACA (2.2 mg/kg, i.p) was administered for 6 h, after the induction of ANP. The extent of acinar cell injury, mortality, systemic cardiorespiratory variables, functional capillary density, renal/hepatic functions, and changes in some enzyme markers for pancreas and lung tissues were investigated.Induction of ANP increased mortality from 0% in the sham group to 43.75% in the ANP + saline group (P 0.05), and administration of NACA significantly reduced mortality to 12.5% (P 0.05). Induction of ANP also caused increases in pancreatic necrosis, serum amylase, alanine aminotransferase (ALT), interleukin-6, LDH in bronchoalveolar lavage fluid, serum urea, tissue myeloperoxidase in pancreas and lung tissues and malondialdehyde. There was less pronounced increase in these parameters in NACA treated group. Compared with ANP group, ANP + NACA group had lower levels of pancreatic necrosis (0.5 ± 0.2 versus 1.45 ± 0.2, P 0.05) and inflammation (0.6 ± 0.2 versus 1.29 ± 00.3, P 0.05) scores.Administration of NACA significantly decreased the ANP-induced mortality and also provided significant improvements in hemodynamic changes. The obtained positive effects of NACA on the course of pancreatitis indicates its potential usefulness in the management of ANP.

Leading-edge protuberances on airfoils or hydrofoils have been considered as a viable passive method for flow separation control recently. In this article, the hydrodynamic performance of a NACA 634-021 (baseline) foil and two modified foils with leading-edge protuberances was numerically investigated using the Spalart–Allmaras turbulence model. It was found that modified foils performed worse than the baseline foil at pre-stall angles, while the lift coefficients at high angles of attack of the modified foils were increased. Both the deterioration of pre-stall and the improvement of post-stall performance were enhanced with larger amplitude of protuberance. Near-wall flow visualizations showed that the leading-edge protuberances worked in pairs at high angles of attack, producing different forms of streamwise vortices. An attached flow along some valley sections was observed, leading to a higher local lift coefficient at post-stall angles. The leading-edge protuberances were considered as sharing a similar mechanism as delta wings, increasing nonlinear lift at large angles of attack. The specific stall characteristics of this leading-edge modification could provide some guidelines for the design of some special hydrofoils or airfoils.

Nascent polypeptide-associated complex (NAC) is a conserved heterodimeric protein consisting of alpha and beta subunits. In addition to acting as a protein translation chaperone by forming a heterodimer with the beta subunit, NAC alpha (NACA) also shows important immune significance independent of NAC beta in mammalian cells. In lower vertebrates, however, the immunological relevance of NACA has not been revealed yet. In the present study, we identified and characterized a NACA gene (termed poNACA) involved in innate immune response in Japanese flounder Paralichthys olivaceus. poNACA encodes a 215-amino-acid protein, with an apparent molecular weight of 23.5 kDa and an isoelectric point of 4.51. Tissue distribution analysis revealed that poNACA gene was constitutively expressed in all examined tissues and showed dominant expression in hepatopancreas and gonad tissues. In enriched Japanese flounder head kidney macrophages and peripheral blood leucocytes, the expression of poNACA mRNA transcript was significantly induced by LPS, Poly(I:C) and zymosan stimulations. In vivo experiments further revealed that poNACA gene expression was up-regulated in head kidney, gill and spleen tissues in response to Edwardsiella tarda challenges. Furthermore, overexpression of poNACA in Japanese flounder FG-9307 cells resulted in increased gene expression of IL-1beta, IL-11 and TNF-alpha, and myxovirus resistance (Mx). Taken together, our findings indicate that an immune response gene, poNACA, involved in innate immune regulation in P. olivaceus has been identified.

More than 100 research articles have referred to an experimental study by [Feldkamp (1987][1]) on the California sea lion, which mentions that its body resembles a symmetric airfoil, NACA 66018. We believe that perhaps an oversimplification has been made in this comparison. This conclusion may be