Measuring thermal conductivity of thin films by Scanning Thermal Microscopy combined with thermal spreading resistance analysis.

While measuring the thermal properties of a thin film, one of the most often encountered problems is the influence of the substrate thermal properties on measured signal and the need for its separation. In this work an approach for determining the thermal conductivity κ of a thin layer is presented. It bases on Scanning Thermal Microscopy (SThM) measurement combined with thermal spreading resistance analysis for a system consisting of a single layer on a substrate. Presented approach allows to take into account the influence of the substrate thermal properties on SThM signal and to estimate the true value of a thin film κ. It is based on analytical solution of the problem being a function of dimensionless parameters and requires numerical solution of relatively simple integral equation. As the analysis utilizes a solution in dimensionless parameters it can be used for any substrate-layer system. As an example, the method was applied for determination of the thermal conductivities of 4 different thin layers of thicknesses from 12 to 100nm. The impact of model parameters on the uncertainty of the estimated final κ value was analyzed.

Favism in a female newborn infant whose mother ingested fava beans before delivery.

We describe a case of favism in a female newborn infant with glucose-6-phosphate dehydrogenase (G6PD) deficiency whose mother had ingested fava beans 5 days before delivery. At birth there were clinical and hematologic signs of hemolytic anemia, hemoglobinuria, and no blood group immunization. Study of the G6PD activity and 2-deoxy-glucose-6-phosphate utilization rate revealed that the infant and the mother were heterozygous for G6PD deficiency.

Increased bilirubin production, ceruloplasmin concentrations and hyperbilirubinaemia in full-term newborn infants.

Ceruloplasmin possesses antioxidant activity in vitro, but such a property has not been substantiated in vivo so far. However, it has been suggested that the lack of factors protective against oxidative haemolysis might have a role in neonatal hyperbilirubinaemia. Ceruloplasmin and alphafetoprotein concentrations were measured in cord blood in 78 unselected full-term singleton newborn infants without G6PD deficiency and haemolytic disease of the newborn; in the same infants, the carboxyhaemoglobin level was assessed on the fourth day of life and taken as an index of bilirubin production. The relationship between these variables and maximum bilirubin level in the first 4 days was studied by multiple regression analysis. High carboxyhaemoglobin levels and low ceruloplasmin concentrations, but not alphafetoprotein resulted, associated with hyperbilirubinaemia (P < 0.001). No relationship was found between carboxyhaemoglobin and ceruloplasmin levels. These results exclude an important role for ceruloplasmin in protecting against possible oxidative haemolysis in full-term newborn infants. Ceruloplasmin levels in cord blood are most probably related to hepatic metabolism and are better predictors of hyperbilirubinaemia than alphafetoprotein concentrations.

[The Silver-Russell syndrome]. / Sindrome di Silver-Russell.

The authors describe a case of Silver-Russell Syndrome with severe deficit growth. They display the major and minor features of the syndrome, and discuss about the possible pathogenetic causes.

'Idiopathic' jaundice in Sardinian full-term newborn infants: a multivariate study.

'Idiopathic' hyperbilirubinaemia in the first 4 days of life was studied in 431 unselected healthy full-term (gestational age > or = 37 weeks) singleton Sardinian infants with birthweight > or = 2500 g. All infants were free from malformations or any disease requiring treatment other than jaundice, they were ABO and Rh compatible with their mothers and were not G6PD deficient. The serum bilirubin level was > 11.9 mg/dl (204 mumol/l) and > 14.9 mg/dl (256 mumol/l) in 37.1% and 15.3% of the study subjects. The vast majority of the infants (94%) were breast fed; no difference in the incidence of jaundice was found between breast-fed and bottle-fed infants. A logistic regression analysis indicated that high alpha-fetoprotein concentrations in cord blood, history of neonatal jaundice in previous full-term siblings, delayed first meconium passage and weight loss were associated with jaundice, defined as a serum bilirubin level > 11.9 mg/dl. These results suggest that the high rate of neonatal hyperbilirubinaemia in Sardinia is mostly related to constitutional and possibly hereditary factors.

[Trisomy 18: phenotypic and biochemical variability]. / Trisomia 18: variabilità fenotipica e biochimica.

We report a case of Edward's syndrome showing some symptoms infrequently described in trisomy 18. The authors suggest that the phenotypic expression of symptoms rarely observed in the syndrome may be better interpreted as non specific consequence of the chromosomal imbalance, rather than directly related to genes on chromosome 18. A gene dosage effect for the enzyme Peptidase A, whose gene is mapped on chromosome 18, was also observed.

[The gene-dose effect for peptidase A on the erythrocytes of a patient with Edwards' syndrome]. / Effetto gene-dose per l'enzima peptidasi A su eritrociti di un paziente con sindrome di Edwards.

The study of gene/dosage effect may be essential in tracing the pathogenetic steps which lead from an unbalanced chromosome anomaly to a pathological phenotype. We present a newborn with a clinical and pathological picture compatible with a diagnosis of Edwards' syndrome. Chromosome analysis on lymphocytes and fibroblasts confirmed the diagnosis showing the presence of trisomy 18. On chromosome 18 the enzyme peptidase A is mapped, and we demonstrated the gene/dosage effect for Pep A in the erythrocytes of our patient.

[Gene-dosage effect of esterase D enzyme on erythrocytes in a patient with Patau's syndrome]. / Effetto gene-dose per l'enzima esterasi D su eritrociti di un paziente con sindrome di Patau.

The study of gene/dosage effect may be essential in tracing the pathogenetic steps which lead from an unbalanced chromosome anomaly to a pathological phenotype. We present a newborn with a clinical and pathological picture compatible with a diagnosis of Patau Syndrome. A chromosome analysis confirmed the diagnosis showing the presence of trisomy 13. On chromosome 13 the enzyme Esterase D (ESD) is mapped, and we demonstrated the gene/dosage effect for ESD in the erythrocytes of our patient.

[Clavicular fractures in the newborn infant]. / La frattura della clavicola nel neonato.

The frequency of the fracture of clavicle in liveborn infants delivered in the Obstetric Department of the School of Medicine of Sassari was retrospectively evaluated for the years 1977, 1978 and 1979. Moreover, all the fractured live infants born in 1980 were prospectively identified and compared to a group of unmatched controls, which included the live infant born immediately before and that born immediately after the index case. The same procedure was adopted when the fracture was identified in two infants born consecutively. The following variables were studied: date and hour of delivery, sex, birthweight, gestational age, type of labour, presentation and mode of delivery, Apgar at one minute, parity of the mother. There were 108 cases and 194 controls. The frequency of the fracture of clavicle showed a linear increase from 2.2/100 live births in 1977 to 4.8/100 live births in 1980; males were slightly more affected than females and the right clavicle was more frequently fractured than the left one (67% for the four years altogether). In the prospective study the only statistically significant differences between cases and controls were found for birthweight (less than 0.001) and mode of delivery (P less than 0.025): cases weighed more and were more frequently born by instrumental delivery (vacuum or forceps) than controls; none of the fractured infants was born by caesarean section. One of the fractured infants was affected by osteogenesis imperfecta and two other presented a transitory paresis of the omolateral brachial plexus; in the remaining cases the prognosis was good.