A Method of Measuring Acoustic Wave Attenuation in the Laboratory

The measurement of attenuation is performed by directly determining the attenuation operator (or the impulse response of the medium) in the time domain. In this way, it is possible to separate the attenuation operator from other non-attenuation effects, e.g. reflections. The Wiener filtering technique, or the damped least-squares, is used to calculate the attenuation operator. For the damped least squares, we have corrected for the effect due to the addition of the damping constant using a perturbation method. Numerical tests are carried out to illustrate the technique. The geometric beam spreading of ultrasonic waves generated by a source of finite size can strongly affect the result of attenuation measurements. Corrections are made by equating the received signal to the average pressure over the receiver surface. The technique is used to measure ultrasonic attenuation in water, glycerol and mud. The measurement in water offers a test of the corrections made for the geometric beam spreading. The measurement in glycerol and mud shows that, in the frequency range of 0.2-1.5 MHz, the attenuation of glycerol increases rapidly with frequency, whereas the attenuation of mud is proportional to frequency, exhibiting a constant Q behavior. The measurements show that the technique used here is an effective approach to the measurement of attenuation.Massachusetts Institute of Technology. Full Waveform Acoustic Logging Consortiu

Outcomes of Cancer Patients Undergoing Percutaneous Pericardiocentesis for Pericardial Effusion

AbstractBackgroundPericardial effusion (PE) is common in cancer patients, but the optimal therapeutic approach is not well defined. Percutaneous pericardiocentesis is less invasive than surgery, but its long-term effectiveness and safety have not been well documented.ObjectivesThe goal of this study was to evaluate outcomes of cancer patients undergoing percutaneous pericardiocentesis for PE and assess the procedure’s safety in patients with thrombocytopenia.MethodsCancer patients who underwent percutaneous pericardiocentesis for PE between November 2009 and October 2014 at the MD Anderson Cancer Center were included. Procedure-related complications, effusion recurrence rate, and overall survival were analyzed.ResultsOf 1,645 cancer patients referred for PE, 212 (13%) underwent percutaneous pericardiocentesis. The procedure was successful in 99% of the cases, and there were no procedure-related deaths. Four patients had major procedure-related bleeding that did not vary by platelet count <50,000/μl or ≥50,000/μl (p = 0.1281). Patients with catheter drainage for 3 to 5 days had the lowest recurrence rate (10%). Median overall survival was 143 days; older age (i.e., >65 years), lung cancer, platelet count <20,000/μl, and malignant pericardial fluid were independently associated with poor prognosis. Lung cancer patients with proven malignant effusions had a significantly shorter median 1-year survival compared with those with nonmalignant effusions (16.2% vs. 49.0%, respectively; log-rank test p = 0.0101). A similar difference in 1-year survival was not observed in patients with breast cancer (40.2% vs. 40.0%; log-rank test p = 0.4170).ConclusionsPercutaneous pericardiocentesis with extended catheter drainage was safe and effective as the primary treatment for PE in cancer patients, including in those with thrombocytopenia. Malignant PE significantly shortened the survival outcome of patients with lung cancer but not those with breast cancer

Effect of Compost and Humic Acid on Potato Growth and Quality

an experiment was carried out in Karbala on 10/9/2014 using the compost of palm residues at four levels (0, 20, 30, 40) tan.h-1 and the humic acid in three concentrations (0,1.5, 3)ml.L-1 to determine the effect of these factors and their interaction in growth and quality characteristics of potato and find organic fertilizer combination instead of chemical fertilizers. The addition of the compost of the residue palm has a significant and positive effect on all studied traits (Number of branches.plant-1, Plant height, percent of the dry weight of vegetative growth, percent of nitrogen, phosphorus and potassium in tubers, ratio of total soluble solids in tubers, percent of starch in tubers, the market yield of the plant), While not affecting on not valid for the marketing year. Spraying of the humic acid caused a significant increase in all the mentioned characteristics except for the percent of phosphorus in the tubers and the not valid for marketing yield. Interaction between palm waste compost and humic acid had a significant effect on the studied indicators except for the percent of phosphorus in the tubers and the not valid for marketing yield of the plant

Dialyzer Reuse Impact on Dialyzer Efficiency, Patient Morbidity and Mortality and Cost Effectiveness

Since the introduction of dialyzer reuse more than three decades ago, several studies have reported its safety, efficacy and cost effectiveness. Reuse of hemodialyzer was prospectively studied in ten chronic hemodialysis (HD) patients recruited from the renal unit, the King Khalid University Hospital, Riyadh, Saudi Arabia, for three months. During the study period, 66 dialyzers were used for 408 sessions of HD, with a mean reuse of 6.2 &#x00B1; 5.3 episodes per dialyser, the mean of maximum reuse episodes being 13.7 &#x00B1; 8.0. The urea reduction ratio was maintained between 73 &#x00B1; 5&#x0025; at baseline to 71.2 &#x00B1; 9.03&#x0025; (p=0.53) at the maximum reuse. Similarly phosphate reduction with each HD session was maintained; mean decrease in phosphate levels was 0.67 mmol/L. Significant increase in heparin requirement was noted; however, the risk of bleeding was not increased. Hematocrit levels increased from 30.4 &#x00B1; 4.1&#x0025; to 33.2 &#x00B1; 3.6&#x0025; at the end of the study (p=0.6). Albumin leak in dialysate decreased with each reuse; baseline 8.27 &#x00B1; 7.93 mg/L to 2.8 &#x00B1; 0.4 mg/L at maximum reuse (p=0.04). Serum albumin levels remained stable. No short-term adverse effects on patients&#x2032; morbidity and mortality were noted. Total cost savings of 53&#x0025; was achieved with the reuse of dialyzers, excluding capital equipment used for preparation for reuse. In conclusion, dialyzer reuse seems to be safe and may provide an economical and efficient dialysis. Studies involving larger number of patients is required to validate this observation

Prevalence of Glomerular Diseases: King Khalid University Hospital, Saudi Arabia

To obtain a more recent and comprehensive insight into the prevalence of glomerular diseases in our patient population, medical records of 200 patients with biopsy proven glomerulonephritis (GN), between January 1994 and June 1999, at the King Khalid University Hospital, Riyadh, Saudi Arabia were analyzed. Primary glomerular disease was found to be the most prevalent, accounting for 63.5&#x0025; of all glomerular diseases. Among primary glomerular diseases, focal and segmental glomerulosclerosis (FSGS) was the most common histological lesion (34.6&#x0025;) and was associated with a high prevalence of hypertension (86.4&#x0025;), nephrotic syndrome (68.18&#x0025;), hematuria (63.6&#x0025;) and renal functional impairment (27.3&#x0025;). Mesangioproliferative GN was the second most common lesion (25.1&#x0025;) followed by mesangiocapillary GN (15.7&#x0025;), IgA nephropathy (10.2&#x0025;), and minimal change disease (8.5&#x0025;). Amongst secondary glomerular diseases, lupus nephritis was the most prevalent (24.5&#x0025;). In conclusion, primary glomerular diseases constituted the commonest group encountered and the prevalence of FSGS was quite high with male sex and young adults predominating. FSGS was also associated with a high prevalence of end-stage renal disease. Further collaborative studies are necessary to explore the predisposing factors and associations of glomerular disease, especially FSGS