Design of a thermic detection system applied to chick embryonated eggs irradiated with infrared rays

Infrared radiations are widely used in medical therapeutics. It has been argued that the doses and the periods of time employed in experimental animals are higher than those used in clinic. Thus, we considered of interest to analyse aspects of dosimetry and thermic effects of infrared rays with current methods in medical practice, using the in ovo chick embryo as a model of easy control. To this end we designed a system to measure temperatures and their acquisitions and software for its handling. The system consists of: a) thermic points: thermocuples or termistores adaptable to the experimental requirements and calibrated with a greater precision within a range of ten degrees around the incubation temperature; b) acquirer circuit of thermic data (hardware): it generates a time base that varies with the thermic sensor. Software: the PC XT or AT detects changes in the time base by means of a programs' in a Turbo Pascal; c) storage and analysis of data allows, through a menu (expansibles) the scale selection, time of program data to be acquired, storage and recovery of the diskette information and graphic impression; d) chick's embryonated eggs. This system allows to measure temperature distribution in small physical spaces with little disturbance of the system to be measured in irradiated bodies, to analyse variations of the temperatures in time and to secure a greater confidence and automatism to obtain the required data.     

Microstructural characterization of controlled forged HSLA-80 steel by transmission electron microscopy

In this study, transmission electron microscopy (TEM) was used to evaluate the effect of controlled forging followed by cooling at various rates on microstructure of an HSLA-80 steel. The observations demonstrate that water-quenched steel has finer multiphase constituents of lath martensite, bainite and twined martensite, whereas air-cooling has resulted in a mixture of bainitic ferrite, retained austenite or MA constituents along with some Widmanstatten ferrite. When the steel is cooled in sand, the maximum volume fraction of polygonal ferrite (PF) was produced which, in turn, increased volume fraction of MA constituents. Precipitation of fine -Cu, Nb and Ti carbides and carbonitrides was observed and identified using energy dispersive spectrometric analysis (EDS) and electron diffraction.     

Testing to predict outcome after transurethral resection of the prostate

PURPOSE: We assessed the ability of routine clinical tests to predict outcome following transurethral resection of the prostate. MATERIALS AND METHODS: A total of 556 men randomized into a trial of surgery versus watchful waiting was evaluated preoperatively with symptom interview, quality of life assessment, uroflowmetry, urinalysis, standard chemistry panel, post-void residual urine determination and cystoscopy. The ability to predict avoidance of postoperative complications, and improvement in quality of life and genitourinary symptoms was assessed in the 249 men randomized to undergo transurethral resection of the prostate. RESULTS: Patients with the highest symptom scores were most likely to have symptom improvement and those most bothered by the symptoms were most likely to have improvement in quality of life. No objective tests measuring physiological parameters made clinically significant contributions toward predicting these outcomes. Lower obstructive symptom scores and larger perioperative infusions of intravenous fluids were associated with a greater chance of complications. CONCLUSIONS: Symptom analysis and quality of life assessment are most useful in selecting patients for transurethral resection of the prostate. Objective diagnostic tests are of limited additional benefit.     

Molecular characterization and phylogenetic distribution of the streptococcal superantigen gene (ssa) from Streptococcus pyogenes

A striking increase in the frequency and severity of invasive infections caused by Streptococcus pyogenes has occurred in recent years. Among these diseases is streptococcal toxic-shock-like syndrome (TSLS), a condition characterized by fulminant soft-tissue destruction and multiorgan failure. Streptococcal superantigen (SSA), a superantigen isolated from a TSLS-inducing, serotype M3 S. pyogenes strain, has recently been identified. We here describe the cloning, sequencing, and phylogenetic distribution of the SSA structural gene. The 783-bp open reading frame encodes a predicted 260-amino-acid protein that is similar in size to several other bacterial superantigens. The deduced sequence of the mature protein is 60.2% identical to that of staphylococcal enterotoxin B but only 49% identical to that of streptococcal pyrogenic exotoxin A. Southern blot and PCR analysis of 138 group A streptococcal strains representing 65 M protein serotypes and 15 nontypeable isolates identified ssa in 68 strains from 10 distinct clonal lineages. All ssa-positive clones expressed SSA. Of the two clones associated with TSLS, the ET 2-M3 lineage, but not the ET 1-M1 lineage, carried the SSA gene. Further analysis of the ET 2-M3 lineage found evidence for temporal variation in ssa association. Contemporary ET 2-M3 disease isolates had ssa, but two older isolates of this clone recovered in 1910 and 1920 lacked the gene. The clonal and temporal distribution patterns of ssa suggest a relatively recent acquisition of this superantigen-encoding gene by the ET 2-M3 lineage, perhaps by horizontal transfer and recombination.     

Subcutaneous compared with intravenous epoetin in patients receiving hemodialysis. Department of Veterans Affairs Cooperative Study Group on Erythropoietin in Hemodialysis Patients

BACKGROUND: Several studies have suggested that if recombinant human erythropoietin (epoetin) is administered subcutaneously rather than intravenously, a lower dose may be sufficient to maintain the hematocrit at a given level. METHODS: In a randomized, unblinded trial conducted at 24 hemodialysis units at Veterans Affairs medical centers, we assigned 208 patients who were receiving long-term hemodialysis and epoetin therapy to treatment with either subcutaneous or intravenous epoetin. The dose was initially reduced until the hematocrit was below 30 percent and then was gradually increased to a level that would maintain the hematocrit in the range of 30 to 33 percent for 26 weeks. We compared the average doses in the 26-week maintenance phase and the discomfort associated with the two routes of administration. RESULTS: For the 107 patients treated by the subcutaneous route, the average weekly dose of epoetin during the maintenance phase was 32 percent less than that for the 101 patients treated by the intravenous route (mean [+/-SD], 95.1+/-75.0 vs. 140.3+/-88.5 U per kilogram of body weight per week; P<0.001). Only one patient in the subcutaneous-therapy group withdrew from the study because of pain at the injection site, and 86 percent rated the pain associated with subcutaneous administration as ranging from absent to mild. CONCLUSIONS: In patients receiving hemodialysis, subcutaneous administration of epoetin can maintain the hematocrit in a desired target range, with an average weekly dose of epoetin that is lower than with intravenous administration.     

On The Optimization of Fractional Order Low-Pass Filters

This paper presents three different optimization cases for normalized fractional order low-pass filters (LPFs) with numerical, circuit and experimental results. A multi-objective optimization technique is used for controlling some filter specifications, which are the transition bandwidth, the stop band frequency gain and the maximum allowable peak in the filter pass band. The extra degree of freedom provided by the fractional order parameter allows the full manipulation of the filter specifications to obtain the desired response required by any application. The proposed mathematical model is further applied to a case study of a practical second- generation current conveyor (CCII)-based fractional low-pass filter. Circuit simulations are performed for two different fractional order filters, with orders 1.6 and 3.6, with cutoff frequencies 200 and 500 Hz, respectively. Experimental results are also presented for LPF of 4.46 kHz cutoff frequency using a fabricated fractional capacitor of order 0.8, proving the validity of the proposed design approach.     

Effect of close-fit sliplining on the hydraulic capacity of a pressurized pipeline

A full-scale laboratory testing setup was used to examine the flow conditions through a new steel pipe with relatively smooth interior (no tubercles, encrustations, holes, scales, etc.) before and after sliplining with a high density polyethylene (HDPE) liner. Results of the tests indicate that the relative roughness of the lined pipe section was generally lower than that of the new steel pipe at Reynolds Numbers of 200,000 to 500,000. The average friction factor (Swamee–Jain) for the lined pipe was 0.0180 compared to 0.0185 for the original steel pipe. The minimum and maximum friction coefficients were 0.0146 and 0.0208 for the lined pipe and 0.0148 and 0.0241 for the new steel pipe, respectively. This indicates that a deteriorated pipe with significant roughness could be restored back to its original condition using close-fit sliplining. Meanwhile, installation of the 6.35 mm (1/4 in.) thick liner in the 152.4 mm (6 in.) pipe reduced its cross-sectional flow area by about 16% and, accordingly, would decrease the flow by about 20% under the same head loss. To further explore this condition, two design parameters, the liner thickness and its buckling resistance, were examined analytically using a practical application of 152.4 mm (6 in.) pipeline with an internal negative pressure due to a water hammer. Results of the analysis indicate that a 3.4 mm (1/8 in.) thick HDPE liner with average quality installation would provide about 100 kPa ( 10 m or 33 ft water column) of buckling resistance, but would also reduce the flow capacity by about 12.7%. While the laboratory tests were only performed on one type of liner material (i.e., HDPE), the general concepts and findings of this study would apply to other types of polymeric liners.     

Microstructure control in functionally graded Al-Si castings

Al-Si functionally graded castings (FGCs) were prepared under centrifugal force. Three compositions were selected; 356, 413 and 390 representing hypoeutectic, eutectic and hypereutectic alloys, respectively. The microstructure and the mechanical properties of the FGCs at different positions were dependent on the centrifugal force. This was more pronounced in 390 FGCs, where the hardness and wear resistance increased towards the inner surface containing the highest volume fraction of primary Si. Grain refining of α-Al was observed in the inner section of 356-FGCs. In 413FGCs, Fe-intermetallics were refined gradually towards the outer surface. Heat treatment spherodized the eutectic Si in case of 356FGCs and increased the hardness from ~60 to 83 (HV). In 390FGCs, precipitation hardening raised the hardness by 20 % while no improvement was observed in 413FGCs. These results emphasize the role of centrifugal force and heat treatment in controlling the microstructure and the mechanical properties of Al-Si FGCs.     

Investigation into Reactions of Starch with Monochlorotriazinyl-β-Cyclodextrin and Application of their Products in Textile Sizing

This article presents a study on the chemical modification of starch and hydrolyzed starches through their reactions with reactive cyclodextrin (RCD). Monochlorotriazinyl-β-cyclodextrin was investigated under a variety of conditions. The results obtained signify that the reaction was favored in an alkaline media rather than an acidic media, and in shorter rather than larger liquor ratios. Maximization of the reaction could also be achieved at 40°C for 60 min. Of the several alkaline catalysts used, NaOH proved to be the best when used at a concentration of 10 g/l. The reaction of starch and hydrolyzed starches with RCD was determined using a concentration of the latter. The apparent viscosity of the resulting polymeric products depends upon both the extent of reaction, expressed as a nitrogen percentage, and the degree of acid hydrolysis prior to the modification. Evidence for involvement of starch and RCD via chemical bonding was obtained through FT-IR analysis. Furthermore, the newly synthesized starch-based polymeric products were applied to a light cotton fabric and further evaluation of the sized materials was conducted by monitoring the size add-on, size removal, and strength properties of the fabric was conducted.     

A method to calibrate a solar pyranometer for measuring reference diffuse irradiance

Accurate pyranometer calibrations, traceable to internationally recognized standards, are critical for solar irradiance measurements. One calibration method is the component summation, where the pyranometers are calibrated outdoors under clear sky conditions, and the reference global solar irradiance is calculated as the sum of two reference components, the diffuse and subtended beam solar irradiances. The beam component is measured with pyrheliometers traceable to the World Radiometric Reference, while there is no internationally recognized reference for the diffuse component. In the absence of such a reference, we present a method to consistently calibrate pyranometers for measuring the diffuse component with an estimated uncertainty of ±(3% of reading+1 W/m²). The method is based on using a modified shade/unshade method, and pyranometers with less than 1 W/m² thermal offset errors. We evaluated the consistency of our method by calibrating three pyranometers four times. Calibration results show that the responsivity change is within ±0.52% for the three pyranometers. We also evaluated the effect of calibrating pyranometers unshaded, then using them shaded to measure diffuse irradiance. We calibrated three unshaded pyranometers using the component summation method. Their outdoor measurements of clear sky diffuse irradiance, from sunrise to sundown, showed that the three calibrated pyranometers can be used to measure the diffuse irradiance to within ±1.4 W/m² variation from the reference irradiance.