Structured surface reflector design for oblique incidence beam splitter at 610 GHz.

An iterative alternate projection-based algorithm is developed to design structured surface reflectors to operate as beam splitters at GHz and THz frequencies. To validate the method, a surface profile is determined to achieve a reflector at 610 GHz that generates four equal-intensity beams towards desired directions of ±12.6° with respect to the specular reflection axis. A prototype is fabricated and the beam splitter behavior is experimentally demonstrated. Measurements confirm a good agreement (within 1%) with computer simulations using Feko, validating the method. The beam splitter at 610 GHz has a measured efficiency of 78% under oblique incidence illumination that ensures a similar intensity between the four reflected beams (variation of about 1%).

Modeling of soiling based on silica-soda-lime glass exposure at six European sites.

Samples of silica-soda-lime float glass, a material selected as a pertinent soiling sensor, were exposed for up to 28 months at four urban sites (Athens, Krakow, London and Prague) and at a semi-urban one (Monte Libretti, near Rome), sheltered from rain. This exhaustive experience permitted to complete and to test the generalisation ability of the results previously obtained on the same material, exposed according to the same protocol, during 24 months, at a single site (Paris). The model previously fitted for the Paris experiment, the Hill equation, could be successfully generalised for four other sites of exposure (Athens, Krakow, Prague and Rome). The analytical form of this model was interpreted in terms of a physical description of the soiling phenomenon. Some of the model coefficients were different from one site to another, depending on the specific environment of exposure (air pollution levels, meteorological factors), while the other ones were rather equivalent. The analysis of the model coefficients, on the one hand, led to an estimation of the period after which soiling is close to its saturation level, and on the other hand, it will permit to correlate these coefficients to the environmental factors, in order to select the most appropriate ones for building dose-response functions for soiling, with broad geographical application.

Testis tumors: review of 125 cases at the Cleveland Clinic.

One hundred twenty-five cases of testicular tumor are reviewed. The prognostic significance of clinical features, certain laboratory test results, and histologic type are evaluated, and treatment results are presented. The most important prognostic clinical feature is the presence or absence of clinically evident metastases. The urinary gonadotropin levels are useful prognostically, but the intravenous pyelogram and lymphangiogram are statistically unreliable. The presence of tumor in retroperitoneal lymph nodes influenced survival only in the patients with embryonal carcinoma. Tumor type influenced survival more than any other pathologic factor. Vascular invasion, local extension, and Leydig cell hyperplasia did not correlate with tumor behavior in germinal neoplasms. Patients with clinical Stage IA or IB teratocarcinoma had an 85 per cent survival rate with a wide variety of treatment.

Hyperactivity and altered amphetamine sensitivity in premature juvenile rats.

'Premature' rats that were delivered by cesarean section on day 21 of gestation and 'normal' rats that were delivered spontaneously on day 22 of gestation were tested for basal locomotor activity and locomotor stimulation in response to D-amphetamine at 19-21 days of age. Compared to normal rats, premature rats had increased basal levels of locomotor activity and showed enhanced sensitivity to the locomotor stimulant effects of D-amphetamine. Cesarean-delivered premature rats may be a useful animal model for investigating mechanisms of neurobehavioral deficits associated with premature birth in humans.

Enhanced cocaine self-administration in adult rats prenatally exposed to cocaine.

Rats that had been prenatally exposed to either cocaine or saline were examined as adults using continuous reinforcement (FR1) cocaine self-administration. Initially these rats were water-deprived and trained to bar-press for water; no differences across prenatal treatments were observed during this training phase. After complete rehydration and implantation of an intravenous cannula into the external jugular vein, animals were introduced to cocaine self-administration with a nocturnal and subsequent 3 h exposure. During daily test sessions rats were allowed to self-administer cocaine for 1 h/day. Prenatal cocaine exposure led to a marked and stable enhancement of the rates of self-administration for up to 13 days, the longest time point examined. These results suggest that prenatal cocaine exposure can alter cocaine reinforcement in adult animals.

Evidence of pre-industrial air pollution from the Heads of the Kings of Juda statues from Notre Dame Cathedral in Paris.

Pollution originating from wood combustion characterised the urban atmospheres of the past and led to the formation of thin grey crusts on the surface of the stone of monuments. The grey crusts discovered on the Heads of the Kings of Juda statues, which adorned the facade of Notre Dame in Paris from the 13th century until 1792, constitute a material record of the effects of this ancient air pollution. The height at which the statues stood suggests that the effect was not the result of a point phenomenon, but was caused by a generalised pollution of the Paris atmosphere at the time.

The incidence of renal anomalies at full term in fetal rats is synergistically increased by estradiol (but not testosterone) supplementation on day 18 of alcoholic gestation.

BACKGROUND/PURPOSE: Fetal alcohol syndrome is characterized by facial dysmorphology, mental and growth retardation, and somatic anomalies including hydronephrosis. The authors sought to determine the influence of exogenous testosterone or estradiol on the incidence of hydronephrosis in a rodent model of fetal alcohol syndrome (FAS). METHODS: Pregnant rats were fed a liquid diet containing 35% ethanol-derived calories from gestation day 6 through 15, with exogenous testosterone or estradiol supplementation on day 18. On day 20, fetal kidneys were examined for evidence of hydronephrosis, and fetal serum estradiol concentrations were determined by radioimmunoassay. RESULTS: Maternal estrogen supplementation resulted in very high fetal serum estradiol levels that were not additionally increased by alcoholism. Despite this fact, the expression of renal malformations was highest in the alcoholic, estradiol-supplemented offspring. Additionally, the rate of renal malformations was significantly higher in the estrogen-supplemented alcoholic group than in the strictly estradiol animals, yet the fetal serum estradiol concentrations did not differ between the two groups. CONCLUSIONS: This suggests that ethanol may act synergistically with estradiol to increase the rate of renal anomalies including hydronephrosis. Such damage may persist via a suppression of normal testosterone-stimulated renal growth and development. FAS includes significant renal anomalies characterized by hydronephrosis in both animal models and affected children. Although the long-term functional sequelae of hydronephrosis and reflux are well known, the progression of renal disease in FAS children remains to be documented.

Dose-response function for the soiling of silica-soda-lime glass due to dry deposition.

Several exposure campaigns of silica-soda-lime window glass have been performed in 30 European sites and 1 in Canada in order to understand, quantify and model the phenomenon of soiling. In this purpose samples were exposed sheltered from the rain. Parallel to exposure, several meteorological parameters and pollution concentrations have been monitored. This paper shows first results on the establishment of a dose-response function for glass soiling. Statistical analyses show that PM(10) is not the only parameter, but also SO(2) and NO(2) atmospheric concentrations seem to be responsible for the optical impairment of glass surfaces, expressed as haze.

Scaling law in carbon nanotube electromechanical devices.

We report a method for probing electromechanical properties of multiwalled carbon nanotubes (CNTs). This method is based on atomic force microscopy measurements on a doubly clamped suspended CNT electrostatically deflected by a gate electrode. We measure the maximum deflection as a function of the applied gate voltage. Data from different CNTs scale into an universal curve within the experimental accuracy, in agreement with a continuum model prediction. This method and the general validity of the scaling law constitute a very useful tool for designing actuators and in general conducting nanowire-based nanoelectromechanical systems.

[Study of dental fluorosis using an ionic microanalyzer]. / Etude de la fluorose dentaire au microanalyseur ionique

Permanent teeth with endemic dental fluorosis, showing mild and moderate mottled enamel, according to the classfication of Dean, were examined with a SMI 300 Cameca ion micro-analyser. In the external third of enamel, abnormally large "sheaths" were disclosed as well as zones characterized by the destruction of prisms. In the dentine, the presence of peritubular dentine rich in Ca, P, FCa, PO, Mg, Na and K has been noted. Hypomineralized spots, poor in these various elements were observed in the intertubular dentine.

Effects of intrauterine position on the hepatic microsomal polysubstrate monooxygenase and cytosolic glutathione S-transferase activity, plasma sex steroids and relative organ weights in adult male and female Long-Evans rats.

The intrauterine position of rat fetuses between siblings of the same or opposite sex has been reported to alter sexually dimorphic behavioral and reproductive traits in the adult. The intrauterine fetal position of adult rats is identified by a three letter code as mMm (a male, M, located between two male siblings, m-m) and fFf (a female, F, positioned between two females, f-f). This study sought to determine whether intrauterine location affected the hepatic polysubstrate monooxygenase and glutathione S-transferase activity, plasma sex steroid levels and organ weights in adult Long-Evans rats. The hepatic microsomal cytochrome P-450 content was higher in females located in utero between two male littermates (mFm) than in females positioned between two females (fFf). NADPH cytochrome c reductase activity was higher in mMm males (positioned in utero between two males) than in fMf males (males contiguous to two female littermates) and female rats. Hepatic microsomal testosterone 2 alpha- and 6 beta-hydroxylase activity was undetectable in fFf female but both activities were measurable in mFm female rats. Testosterone 7 alpha-hydroxylase and 5 alpha-reductase activity was higher in females than in males, and higher in fFf than in mFm females. Glutathione S-transferase activity was not altered by fetal contiguity in male and female rats. Adult mMm males had a higher plasma testosterone level and relative gonadal weight, and lower plasma estradiol concentration than fMf males. The plasma progesterone concentration of fFf female was lower than that of mFm female rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Lateral decompression of a pathological disc in the treatment of lumbar pain and sciatica.

The posterolateral approach external to the vertebral canal allows decompression and the escape of disintegrating bits of abnormal nucleus pulposus. This simple, rapid, and least traumatic procedure is sufficient to relieve and to cure a significant number of patients (approximately 40%) suffering from intervertebral disc-related lumbar pain or sciatica. Among 225 patients with 338 discs operated on by the lateral decompression technique in the interval from 1978 to 1984, the overall results are encouraging.

The study of human dentine with secondary ion microscopy and electron diffraction.

The highly polished surface of serial transverse ground sections of human coronal dentine were coated under vacuum with an aluminium grid and studied with a SMI 300 ion microanalyser (Cameca, Paris) based on mass spectrography. Secondary ion microscopy demonstrated a qualitative distribution of calcium, phosphorus, magnesium, sodium and potassium. A higher content in Ca, P and Mg was noted in peritubular dentine. Selective area electron diffreaction patterns of this zone, using LiF as standard, showed the presence of whitlockite in peritubular dentine where about 1% in weight of magnesium seemed to be incorporated.