Thermal radiation transferred to the guided modes of optical interference coatings.

An electromagnetic model is developed to predict the thermal radiation which is trapped in a multilayer structure and transferred to its guided modes. The theory is based on the electromagnetic power supplied by the thermal currents given by the fluctuation-dissipation theorem. The source of the radiation is the ambient temperature or that caused by the optical absorption of the component subjected to spatio-temporal illumination. A numerical example is given for a multi-dielectric mirror at thermodynamic equilibrium. It is shown that the thermal radiation transferred to the guided modes of the multilayer can be much larger or lower than the radiation emerging in free space outside the component.

Photo-induced thermal radiation of optical interference coatings submitted to a spatio-temporal illumination.

We present an electromagnetic model for photo-induced thermal radiation in multi-layer interference filters subjected to arbitrary pulsed illumination with limited beam size. Numerical calculation is used to analyze various structures affecting thermal radiation, such as multi-dielectric mirrors in the mid-infrared range. Other zero-admittance structures are shown to strongly confine and enhance the thermal radiation with an emissivity close to unity at pre-defined frequencies (wavelength and angles). Calculation tools are chosen that encourage the use of techniques for synthesizing thin-film multilayers able to control thermal radiation.

Photo-induced temperature in optical interference coatings.

The photo-induced temperature in multilayer systems is calculated using an original analytical model based on optical/thermal analogies. Various illumination regimes are considered, ranging from ps pulses to a continuous regime, while taking into account a variable repetition rate. The temporal and spatial (3D) resolutions are quantified, and the distributions of temperature and stationary optical field are compared. The temperature spectra are given as a function of the illumination wavelength. Thermal and electromagnetic damage thresholds are compared. Lastly, the thermal fringes resulting from structured optical illumination are studied.

Validation of two methods to measure posterior tilt in femoral neck fractures.

INTRODUCTION: Posterior tilt of the femoral head in femoral neck fractures (FNF) may influence stability of the fracture and may therefore affect the treatment outcome. Posterior tilt can be measured with different methods. The Lateral Garden Angle (LGA) has been used for this purpose for decades and more recently the Posterior Tilt Measurement (PTM) was introduced. Despite the fact that both methods (LGA and PTM) are used in multiple studies, they have never been compared for reliability in a direct study. The aim of this study is to analyze the intra and inter observer reliability of the LGA described by Garden and the PTM according to Palm. METHODS: Four observers measured the posterior tilt on the radiographs of 50 FNF two times with both methods. Intra and inter observer reliability were determined for the LGA and the PTM. RESULTS: The intra observer reliability for both methods is substantial with an intra class coefficient of 0.75. The inter observer reliability of the PTM is also substantial with an intra class coefficient of 0.75 compared to a moderate reliability of the LGA with an intraclass coefficient of 0.60. CONCLUSION: Based on our results we believe the LGA and the PTM are both reliable methods to measure posterior tilt. Yet the Posterior Tilt Measurement seems to have a better inter observer reliability and therefore has a slight preference over the Lateral Garden Angle.

[The prevalence of type II diabetes mellitus in rural urban population over 35 years of age in Lublin region (Eastern Poland)]. / Badania nad wystepowaniem cukrzycy typu 2 w populacji powyzej 35 roku zycia na wsi i w miescie w regionie lubelskim.

The prevalence of type 2 diabetes mellitus (DM 2) has increased dramatically in the last decade. Data relating to the number of undetected cases of diabetes are underestimated. The aim of the study was to evaluate the prevalence of DM 2, obesity, hypertension, and lipid disturbances in a representative group of urban and rural population in the Lublin region (Eastern Poland). The study was performed in 1998-2001. A two-layer draw was applied: two groups of 3000 people were drawn from the population of Lublin town and from the rural areas each comprising 100,000 inhabitants. In all subjects physical examination was performed and body weight, height, and blood pressure measurements were obtained. Blood samples were taken from the basilic vein to estimate: blood glucose, lipids and insulin concentration. Venous blood glucose concentration was measured using a Glucotrend glucometer. Oral glucose tolerance test (OGTT) after a 75 g-glucose load was performed in subjects without previously diagnosed diabetes mellitus and when the fasting blood glucose was < 8.0 mmol/l (144 mg/l). The LDL-cholesterol level was calculated according to Friedewald formula. DM 2 was identified according to the WHO criteria from 1985. Obesity and hypertension were diagnosed according to the new WHO criteria (Body Mass Index > or = 30 kg/m2, blood pressure > or = 140/90 mm Hg). 3782 subjects: 1809 in the rural area and 1973 in Lublin town were examined. The response rate among rural and urban population was 60.3% and 65.8% respectively. The prevalence of DM 2 was assessed in 17.6% of rural and in 14.1% of urban population. 75% of diabetics in the rural areas and 56% in the town were the newly diagnosed cases. We found impaired glucose tolerance in 30.3% of rural and in 21.6% of urban population, BMI > or = 30 kg/m2 in 30.8% and 30.1%, hypertension in 69.4% (29.2% newly diagnosed) and 68.6% (27.7% newly diagnosed), hypercholesterolaemia (total cholesterol > or = 5.2 mmol/l (200 mg/dl)) in 66.4% and 60%, hyper-LDL-cholesterolaemia (> or = 3.5 mmol/l (135 mg/dl)) in 57.3% and 52.6%, hypo-HDL--cholesterolaemia in 21.7% and 31.4%, hypertriglyceridemia (> or = 2.3 mmol/l (200 mg/dl)) in 15.1% and 22% respectively. This finding indicates the urgent need for introducing a national program for early diagnosis and prevention of DM 2 and concomitant metabolic disturbances.

Destination of debris during intramedullary reaming. An experimental study on sheep femurs.

This study was designed to further explain the better fracture healing in fractures treated with a reamed nail. It investigates the location and quantity of the reaming debris in an ex vivo animal model to test the autograft theory. In 10 cadaveric sheep femurs, a 5-mm semicircular gap was created at the midshaft. The medullary cavity was opened and the reaming debris that dropped from the gap during reaming and the debris from the proximal opening were collected and weighed separately. The mean harvest of reaming debris at the gap was 0.99 g +/- 0.12 g (24%) and from the proximal opening at the medullary cavity 3.08 g +/- 0.31 g (76%) (total 4.07 +/- 0.34 g). This study proves that a significant amount of reaming debris collects at an artificial fracture gap during reaming of the medullary cavity. This finding supports the theory of bone autografting.

Diagnostic dilemma of an unsuspected hyperfunctioning accessory parathyroid gland after total parathyroidectomy with autotransplantation in a peritoneal dialysis patient.

Persistent or recurrent hyperparathyroidism in patients with chronic renal failure may be a frustrating problem. We report a case history of a peritoneal dialysis patient who underwent total parathyroidectomy with autotransplantation for secondary hyperparathyroidism, developed tertiary hyperparathyroidism, and in an attempt to control hypercalcemia underwent seven partial resections of the autotransplant. Subsequently, a total excision of the parathyroid autograft was performed, but the patient continued to have hyperparathyroidism and unexpectedly was found to have a hyperplastic fifth parathyroid gland identified by thallium-technetium subtraction scan. The fifth gland was removed, and a part was implanted in the right forearm; however, the autoimplant had to be completely removed because of rapidly developing hypercalcemia. Hypercalcemia was controlled, but elevated levels of parathormone persisted. Remaining parathyroid tissue could not be found.

Comparative antitussive effects of dextrorphan, dextromethorphan and phencyclidine.

The possible antitussive effects of dextrorphan (the (+) isomer of levorphanol) and phencyclidine (PCP) were compared to well known antitussive properties of dextromethorphan in the post-halothane anesthetized decerebrate cat in which cough was elicited by direct electrical stimulation of the cough center. Dextrorphan, when injected i.a. (0.05-0.32 mg kg-1) or i.v. (1 to 3 mg kg-1), PCP i.a. (0.1-0.32 mg kg-1) or i.v. (1.0 mg kg-1) had no effect on electrically elicited cough. After i.v. administration, dextrorphan caused a variable effect on respiration but did not have any respiratory effect with i.a. administration of the drug. PCP injection i.a. at 0.32 mg kg-1 severely inhibited respiration though coughing could still be elicited. But i.v. administration of 1.0 mg/kg-1 suppressed both cough and respiration for several hours. Dextromethorphan inhibited cough upon both i.a. and i.v. injection. The mean effective i.a. dose was 0.063 mg kg-1. A ten times higher dose was necessary (0.65 mg kg-1) for cough suppression by the i.v. route. It is concluded from the i.a./i.v. ratio that dextromethorphan has specific central antitussive activity not possessed by dextrorphan and PCP.

Comparative effects of diazepam and midazolam on paraoxon toxicity in rats.

The present study was undertaken to compare the effectiveness of a new water-soluble benzodiazepine, midazolam, to diazepam, both administered im for protection against diethyl-p-nitrophenyl phosphate (paraoxon) toxicity. Adult male Sprague-Dawley rats were pretreated with midazolam or diazepam (0.32-32.0 mg/kg) alone or in combination with atropine (10.0 mg/kg). Twenty minutes later 2 X LD50 of paraoxon was injected sc and the incidence of seizures and death were recorded for 24 hr. In another series of experiments, the LD50 of paraoxon was evaluated in the rats pretreated im with atropine (10.0 mg/kg) and midazolam or diazepam (10.0 mg/kg). Pretreatment with atropine alone did not prevent paraoxon-induced seizures but did reduce mortality. Both benzodiazepines were very effective alone or when combined with atropine in reducing the incidence of paraoxon-induced seizures. When given alone, neither benzodiazepine protected against paraoxon-induced mortality. However, when combined with atropine both benzodiazepines dramatically decreased the lethality of 2 X LD50 of paraoxon. In equal doses given im, midazolam proved to be more potent than diazepam.

Evidence for a central site of action for the antitussive effects of caramiphen.

The antitussive properties of caramiphen edisylate were studied in the decerebrate cat in which cough was elicited by direct electrical stimulation of the cough center. In this preparation dextromethorphan hydrobromide was compared to caramiphen as an antitussive agent. Dextromethorphan was somewhat more potent when given i.v. as well as when given directly into the left vertebral artery (i.a.). Both agents were far more effective when given i.a. than when given i.v. The effective dose ratios of i.v./i.a. were about 12 and 14 for caramiphen and 11 and 7 for dextromethorphan (actual and cumulative doses). These ratios indicate that both agents have a central rather than a peripheral site of antitussive action. Both drugs had antitussive effects in i.a. doses which did not alter arterial blood pressure or respiration greatly. However, after i.v. administration transient changes in both arterial blood pressure and respiration were observed with both agents. It was concluded that the antitussive action of both caramiphen and dextromethorphan is due to a selective effect on the cough center in the brainstem of the cat. On a milligram per kilogram basis, caramiphen required a 3 to 4 times larger dose than dextromethorphan for equieffective antitussive effects.

Scopolamine, morphine, and brain-stem auditory evoked potentials in awake monkeys.

The effects of scopolamine and morphine sulfate on brain-stem auditory evoked potentials (BAEPs) were studied in 10 rhesus (Macaca mulatta) monkeys. Study drugs were given intravenously to unanesthetized animals and BAEPs recorded at 3-min and 30-min intervals after administration of 0.1 mg/kg and 0.32 mg/kg of scopolamine and 15 min after administration of 3.2 mg/kg morphine at the end of the experiment. No significant change in either latency or amplitude of different components of BAEPs was observed.