46,XX/69,XXX diploid-triploid mixoploidy with hypothyroidism and precocious puberty

We report a 20 month old female patient with diploid-triploid mixoploidy (46,XX/69,XXX) syndrome with hypothyroidism and precocious puberty. The triploid cell line was only expressed in the fibroblast culture and comprised the majority (95%) of the cells. Chromosome analysis of the fetal blood sample and peripheral blood sample were normal. The patient shows typical features of full triploidy (growth and severe mental retardation, cranial and facial dysmorphism, complete syndactyly of fingers 3/4, partial syndactyly of toes 2/3) and facial but no body asymmetry. At the age of 5 months central hypothyroidism and precocious puberty were diagnosed. Thin pigmented streaks were visible on the wrists and legs of the patient at the age of 16 months. This is the first patient reported so far with 46,XX/69,XXX mixoploidy suffering from hypothyroidism and precocious puberty.     

Reminiscence: diffraction and the mountains of Alaska

Discusses, from a personal point of view, experiments carried out to study the diffraction and propagation of VHF, HF and MF radio waves in the early-mid 1950s in the mountains of Alaska     

Transvaginal multifetal pregnancy reduction: Which? When? How many?

This report contains the experience of our centre, using the transvaginally guided puncture procedure, to reduce the number of fetuses in a multifetal pregnancy to a lower number. The aim of the procedure was to improve perinatal outcome and/or to meet the personal desires of patients and their families. We surveyed 148 multifetal pregnancy reductions. The fetus or fetuses overlying the internal os was most commonly reduced. The total uncorrected loss of the entire pregnancy was 13.4%. The corrected pregnancy loss was 11%. Of the 63 twins left after the reduction, 33 delivered preterm. Of the 36 singletons, two delivered preterm. Our conclusion was that multifetal pregnancy reduction is a safe procedure for the mother and has an acceptable loss rate of the entire pregnancy. The reduction of a fetus overlying the internal os by the transvaginal puncture procedure seems to yield results at least as good as the transabdominally performed puncture procedures for multifetal pregnancy reduction.     

The effects of suppressed beta tin nucleation on the microstructural evolution of lead-free solder joints

Most lead-free solders comprise tin (Sn) as the majority component, and nominally pure β-Sn is the majority phase in the microstructure of these solders. It is well established that nucleation of β-Sn from Sn-base liquid alloys is generally difficult. Delays in the onset of β-Sn formation have a profound effect upon the microstructural development of solidified Sn-base alloys. Utilizing stable and metastable phase diagrams, along with solidification principles, the effects of inhibited β-Sn nucleation on microstructural development are discussed, employing the widely studied Sn–Ag–Cu (SAC) alloy as a model system. This analysis shows that the main effect of suppressed β-Sn nucleation on near-eutectic SAC solders is to increase the number and/or volume fraction of primary or primary-like microconstituents, while simultaneously decreasing the volume fraction of eutectic microconstituent. General strategies are outlined for avoiding unwanted microconstituent development in these materials, including the use of metastable phase diagrams for selecting alloy compositions, employment of inoculants to promote β-Sn nucleation, and utilization of high cooling rates to limit solid phase growth. Finally, areas for future research on the development of inoculated Sn-base solder alloys are outlined.     

A comparison of two correlation schemes

Processes involving the cross-correlation of two noisy data streams are frequently encountered in signal processing. The performances of two commonly used correlators, the simple and complex correlators, are examined. The conventional view is that the complex correlator is superior to the simple correlator by a factor of the square root of two in output signal-to-noise ratio (SNR). However, by modifying the simple correlator to utilize all the available information, its performance is improved. The development of the modified correlator is explained, and a computer simulation shows that this modified correlator is approximately equivalent to the complex correlator in noise performance