Long-term efficacy of dietary weight loss in sleep apnoea/hypopnoea syndrome

Weight loss is associated with clinical improvement in sleep apnoea/ hypopnoea syndrome (SAHS). The aim of this study was to ascertain whether the therapeutic efficacy of dietary weight loss is maintained in the long-term. From a total of 216 overweight SAHS patients treated by only a weight reduction programme, 24 cured by this method (apnoea/hypopnoea index (AHI) at diagnosis 443+/-27.8, after weight loss 3+/-3.1) were re-evaluated after a mean (+/-SD) period of 94.3+/-27.4 months post-cure. No correlation was found between changes in AHI and body mass index experienced by each patient in the two phases of the study (diagnosis to cure and cure to long-term follow-up), r=0.29, p=0.156, demonstrating a marked intra-individual variability. Six of the 13 patients who maintained their weight presented recurrence of SAHS (AHI 40.5+/-24.1) as did eight of the 11 who had regained weight (AHI 44.3+/-23.). Weight maintenance was more frequent among patients who had continued to attend periodic appointments, 10/11 versus 3/13 (p<0.001). In conclusion, weight-loss efficacy is maintained in the long-term in some sleep apnoea/hypopnoea syndrome patients. This study indicates the need for periodic follow-up of these patients as a reinforcement for weight maintenance and for early detection of the reappearance of sleep apnoea/hypopnoea syndrome.     

Hoechst 33342 stain and u.v. laser exposure do not induce genotoxic effects in flow-sorted boar spermatozoa

Sex selection by flow cytometry/cell sorting involves the staining of spermatozoa with Hoechst 33342 in combination with the impact of a u.v. laser beam, two potentially mutagenic agents. A phenotypic and cytogenetic study of lymphocytes of piglets born after insemination with spermatozoa stained with Hoechst 33342 and from piglets obtained from stain-sorted spermatozoa was performed to evaluate the genotoxic effect of Hoechst 33342 staining and u.v. laser irradiation on the offspring. Lymphocytes from piglets born after insemination with unstained spermatozoa, but from the same ejaculate, were used as a control group. Peripheral blood lymphocytes from these piglets were cultured following a standard cell culture protocol. Cells were then collected by centrifugation, subjected to hypotonic solution and fixed and dropped onto slides. Sister chromatid exchanges (SCEs) and chromosome aberrations (CAs: including chromosome and chromatid breaks) per cell were scored in 50-s division metaphase spreads from each donor. Reproductive parameters and litter performance of all inseminations performed were also recorded in all groups. Data were analyzed by ANOVA. No significant increase (P > 0.05) of SCE and CA frequencies were observed in piglets born from stained spermatozoa or from stain-sorted spermatozoa with respect to controls (untreated sperm). The results indicated that no mutagenic effect on spermatozoa, expressed as increases in the incidence of abnormalities in the resulting offspring and also as increases in SCE and CA frequencies on lymphocytes from these individuals, was induced by the staining of boar spermatozoa with Hoechst 33342, nor by combination of staining with laser impact during flow cytometry.     

Respiratory allergies on the staff of the police force

The aim of the study was to evaluate respiratory allergies of an occupational nature in the staff of the police force. Five hundred and eighty-five subjects were submitted for lung function tests by dynamic spirometry. Subjects with a history of respiratory symptoms and border line respiratory function underwent bronchial provocation tests with methacholine. If FEV1 was < 80%, a bronchial reversibility test was performed. Allergic tests (skin and RAST) for inhalating allergens (perennial, seasonal and occupational) were performed. The results suggested asthmatic symptoms in 57 subjects, eight of whom were positive to skin and RAST tests for occupational inhalating allergens. Among these eight subjects, three had FEV1 < 80% of the theoretical value without therapy, and five showed obstruction of small caliber airways (MEF 25, MEF 50, FEF 25-75 < 65% of the theoretical value). The analysis showed a low percentage of respiratory occupational allergies. Among 21 subjects positive to Dermatophagoides, seven worked as archivists. In these workers, a concomitant occupational cause for the symptomatological and functional pattern was established.     

Band-Pass Filter Design with Diagnosis Facilities Based on Predictive Techniques

We have studied the feasibility of designing a second-order band-pass filter which can provide itself information about its central frequency when it is led to an specific operation mode (calibration mode). The filter has been built with discrete components around a TL071 Operational Amplifier. When a control digital signal toggles the calibration mode, the filter components are reconfigured into an oscillator thanks to some analog switches. The oscillation frequency allows predicting the filter central frequency with an rms error of 0.33%. Since there are many possibilities to reconfigure the filter into an oscillator and the choice of the best test-mode oscillator in terms of predictability demands a great deal of computational effort, we have found out a simple criterion for choosing the best scheme avoiding that effort. This criterion takes into account the sensitivities of the performance parameters (the central frequency) and the test observables (the oscillation frequency) with respect to the passive and active components of the filter.     

High deposition rate hydrogenated polymorphous silicon characterized by different capacitance techniques

High deposition rate hydrogenated polymorphous silicon thin films were analyzed using different capacitance techniques. The distribution of localized states and some electrical properties were studied by the temperature, frequency and bias dependence of the Schottky barrier capacitance and deep level transient spectroscopy. Our different samples present different groups of gap states depending on the preparation conditions. A comparison with standard amorphous silicon films reveals a reduced density of states in the gap for high deposition rate samples. Our results show that the samples, which represent only one group of gap states and lower density of states in the gap, were the samples grown at deposition rate of 8 Å/s.     

Kinetics of alkaline decomposition and cyanidation of argentian ammonium jarosite in lime medium

The alkaline decomposition of argentian ammonium jarosite in lime medium is characterized by an induction period and a conversion period in which the sulfate and ammonium ions pass to the solution whereas calcium is incorporated in the residue jointly with iron; this residue is amorphous in nature. The process is chemically controlled and the order of reaction with respect to the hydroxide concentration is 0.4; the activation energy is 70 kJ mol⁻¹. Cyanidation of argentian ammonium jarosite in lime medium presents the same reaction rate in the range of 0–10.2 mol m⁻³ CN⁻; in this range of concentration, the cyanide process can be described, as in other jarosites, in a two-step process: a step of alkaline decomposition that controls the overall process followed by a fast step of silver complexation. For higher cyanide concentration, the order of reaction with respect to cyanide is 0.65, and kinetic models of control by chemical reaction and diffusion control through the products layer both fit well; the activation energy obtained is 29 kJ mol⁻¹; this is indicative of a mixed control of the cyanidation process in the experimental conditions employed. The process is faster than was observed in ammonium jarosite generated in zinc hydrometallurgy (Industrial Minera México, San Luís Potosí, México); it seems that the reaction rate decreases when the substitution level in the jarosite lattice increases; this behavior is similar to that observed for synthetic potassium jarosite and arsenical potassium jarosite from gossan ores (Rio Tinto, Spain) presented in a previous paper.     

Characterization of crosstalk noise in submicron CMOS integratedcircuits: an experimental view

A way to characterize the crosstalk noise susceptibility for integrated circuits fabrication technologies is presented. A comparison between 0.7- and 0.35-μm technologies shows the increasing importance of crosstalk noise and, therefore, the need to consider this effect at the design level in submicron integrated circuits. An approach to measure the internal crosstalk generated by long metal interconnects based on using an RS latch sensor is proposed. An implementation and experimental measurements for 0.7-μm technology are reported, confirming the very high noise peak values     

Measurement of crosstalk-induced delay errors in integratedcircuits

Coupling between lines may cause a variation in the effective transition delay in a digital signal path if there exists a simultaneous transition in the coupled lines. The authors present a measurement method for this effect, using a specifically designed integrated circuit. It is shown that the effect may produce either an increase or a decrease in the critical path, therefore altering the maximum frequency specification of a synchronous sequential circuit