Coagulation and fibrinolysis after moderate and very heavy exercise in healthy male subjects

OBJECTIVES To correlate renal function with the site of the ectopic orifice in patients with a single ectopic ureter and to evaluate the role of ureteric reimplantation in the preservation of renal function. PATIENTS AND METHODS: Forty-four patients (41 female, age 1.5 months to 20 years) with a single ectopic ureter have been managed in our institution in the last 21 years. The classical symptom of continuous wetting with intermittent normal micturition was reported in most of the female patients. The investigative evaluation included intravenous urography (i.v.U), cysto-urethroscopy, vaginoscopy with retrograde ureteric catheterization, micturating cysto-urethrography (MCU) and ultrasonography. Diuretic renography was carried out in four patients after it became available in 1992. Renal function was assessed in relation to urinary tract anomalies and with outcome after ureteric re-implantation. RESULTS: Thirty-eight patients (two males) had a unilateral ectopic ureter; the ectopic orifice was vaginal in 12, vestibular in 11, urethral in nine, at the bladder neck in two, the seminal vesicle in one and undetermined in three. Twenty-one patients had renal and/or ureteric abnormalities, with reflux detected on MCU in three ureters. Associated anomalies included hypospadias (two, one female), skeletal anomalies (two), anorectal malformations (three), cryptorchidism (two), and unilateral cystic ovary (one). Two patients had preoperative hypertension. In 15 patients, renal function was considered sufficient to justify ureteric reimplantation, 14 of whom regained continence. One girl had suprapubic leakage from the bladder and died during secondary nephroureterectomy. Another girl had persistent incontinence; she was found to have contralateral duplex ureters with a vestibular ectopic orifice and was cured after upper polar heminephroureterectomy. i.v.U and renography carried out in two patients each within 4 weeks of surgery showed a moderate improvement in renal function. Eight patients reported for follow-up after ureteric reimplantation (mean duration 11 months); none had hypertension or urinary infection. Twenty-three patients with rudimentary kidneys underwent nephroureterectomy. Histopathological examination of the excised kidneys showed moderate to severe dysplasia with chronic pyelonephritis. Six patients (one male) had bilateral single ectopic ureters, with normal renal function in the five females. Unilateral reimplantation in the boy resolved the symptoms; one girl died before surgery and the other four underwent bilateral ureteric reimplantation, after which one was dry for up to 3 h while the other three were incontinent, one of whom subsequently underwent urinary diversion. CONCLUSIONS: There was no clear correlation of renal function with the site of the ectopic ureteric orifice, as most of the patients with a vaginal ectopic ureter had sufficient renal function to justify renal preservation. Ureteric reimplantation preserved renal function, although the improvement after surgery was determined by the degree of renal dysplasia.     

Selective and uniform laser-induced failure of antireflection-coated LiNbO3surfaces

LiNbO3surfaces with different antireflection coatings and from different vendors were damaged with 1.06 μm 9.5 ns full width at half maximum laser pulses. By probing with a laser spot smaller than the separation of isolated surface defects, it was possible to separate uniform damage, which was characteristic of the coating itself, from premature defect-driven localized failures. Uniform failure modes were identified and thresholds extracted for each by multithreshold analysis. Frequency of defect damage was determined at several fluences much lower than required for uniform failure. It is likely that defect-driven selective failures reduce the apparent damage threshold of flood-loaded samples. Tentative identification of a selective damage threshold was made and correlated with large-spot multimode test results. Incorporation of these results into a product-improvement program has resulted in LiNbO3Q-switches with increased resistance to selective damage.     

Collector performance enhancement with flat reflectors

The use of diffuse and specular flat reflectors to enhance the performance of flat-plate solar collectors has been explored by means of Fortran routines which optimize the size, shape, and placement of reflector and collector. Configuration factors for systems with a diffuse reflector and a collector whose absorptance varies with incidence angle are presented. Specular reflectors are more effective than diffuse reflectors, and, if south-facing, should be used with collectors which are elongated in the east-west direction. Design curves for the specific system of horizontal collector and south-facing reflector are presented. In this system, a moderately sized reflector can increase the midwinter yield per unit collector area by several times.     

Pulsed laser-induced melting of precision diamond- machined Cu, Ag, and Au at infrared wavelengths

Threshold for characteristics of pulsed laser-induced damage have been measured on precision diamond-machined Cu, Ag, and Au surfaces at 10.6, 3.8, 2.7, and 1.06 μm wavelengths. Pulse lengths range from 2 μs to 9 ns, and focal spot diameters range from 238 to 52 μm. Comparison is made with melt thresholds calculated from one-dimensional heat flow considerations with a spot-size correction. The calculation incorporates waveform shape, as well as temperature-dependent absorption and thermal properties. Agreement is excellent for Ag, except at 1.06 μm, while agreement for Cu and Au is good only at 10.6 μm. Results suggest that disturbance of crystalline surface order has an important influence, especially at wavelengths shorter than 10.6 μm. A singular departure from calculated Cu and Au thresholds at 3.8 μm, using a multipeaked waveform, may have important implications for repetitively pulsed applications. For Cu at 10.6 μm, damage scales with pulse length according to thesqrt{tau}law provided the pulse length as appropriately defined.     

Effect of surface preparation methods on laser-induced pitting of copper mirrors at the 10.6 µm wavelength

Ten precision Cu laser mirrors prepared by eight different methods were evaluated at 10.6 μm for resistance to spatially selective laser-induced damage (pitting). Surfaces essentially free of pitting and with melt thresholds close to that of intrinsic Cu were produced by electron-beam melting bulk Cu, followed by diamond turning; by diamond turning with a 20° negative top rake angle; by chemical vapor deposition of pure Cu on a diamond-turned Cu substrate; and by polishing bulk Cu on a hard lap with high pressure. The electron-beam melted surface was the most damage resistant, but residual stresses left by the melting process degraded the optical surface figure. A special cleaning method was developed to remove optically absorbing contaminants trapped by surface defects.