Notes: Double-heterostructure devices of type AlxGa1−xAs/GaAs have been fabricated in thin films grown by the cleavage of lateral epitaxial film for transfer process. The electron lifetime in the p-type GaAs is measured by photoluminescence and found to be 32 ns at the 5×1016 cm−3 doping level. This is the largest reported lifetime for a freestanding GaAs thin film.

Notes: Ab initio quadrupole coupling constants χ(D), χ(14N) for deuterium and nitrogen nuclei are obtained for the sequence of linear (HCN)n clusters (up to n=6) at the RHF/6-31+G* level, complementing previous studies of n-dependent "cooperative'' effects in these C–H...N hydrogen-bonded species. For the dimer and trimer, the theoretical values are compared with experimental equilibrium values of Gutowsky and co-workers and found to successfully reproduce both the magnitudes and patterns of measured shifts. For larger (HCN)n clusters, the n-dependent trends in χ(D), χ(14N) appear to be correlated with cooperativity effects found previously (binding energies, geometrical parameters, dipole moments, ir frequencies and intensities). This suggests that quadrupole coupling measurements can provide a useful probe of cooperative H-bonding phenomena in gaseous and condensed media. © 1995 American Institute of Physics.

Notes: YLM, a codaominant polymerase chain reaction (PCR) marker linked to Yd2, could substantially improve the precision and efficiency of barley yellow dwarf virus (BYDV) resistance breeding. The aim of this study was to assess the effectiveness of YLM in a marker-assisted introgression programme and to quantify associations between the presence of Yd2 and other agronomic and quality traits. The Yd2 gene was introgressed into a BYDV-susceptible background through two cycles of marker-assisted backcrossing. BC2 F2-derived lines, either carrying or not carrying the YLM allele associated with resistance, were compared in the presence and absence of BYDV. The YLM marker was shown to be effective in the introgression of Yd2. Lines carrying the YLM allele associated with resistance produced significantly fewer leaf symptoms and showed a reduction in yield loss when infected with BYDV. There were no deleterious effects associated with the introgression of Yd2 on grain yield, grain size or malting quality. The implications of marker-assisted selection for Yd2 on barley improvement are discussed.

Notes: Background and objectives A reduced capacity of antigen presenting cells (APC) to provide pro-T helper 1 (Th1) signals, such as IL-12, to T cells during early life may be implicated in the development of T helper 2 (Th2)-mediated allergic disease. In this study we examined the relationships between the capacity for IL-12 responses in the neonatal period and atopic risk (family allergy), in vitro T cell responses to allergens, and the subsequent development of allergic disease at 6 yearsMethods The capacity of circulating neonatal (and maternal) APC to produce IL-12 p70 in response to LPS (and IFN-γ) stimulation was assessed in a group of 60 children with previously well-characterized immune responses to allergens and atopic outcomes. The IL-12 responses were compared with allergen-induced lymphoproliferation (to house dust mite (HDM) ovalbumin (OVA), cat and β-lactoglobulin (BLG)) and IL-13 and IFN-γ cytokine responses (to OVA, HDM and phytohaemaglutinin (PHA)) in the neonatal and postnatal periods. IL-12 responses were also compared according to atopic risk and atopic outcomes (doctor-diagnosed asthma, eczema, food allergies and sensitization as evidenced by skin prick testing) at 6 years clinical follow-up.Results Maternal peripheral blood mononuclear cells (PBMC) synthesized significantly greater amounts of IL-12 than neonatal PBMC, though within maternal-infant pairs IL-12 responses were significantly correlated (r = 0.4, P = 0.019). Moreover, neonatal IL-12 responses were positively correlated with neonatal allergen proliferation for HDM (r = 0.6, P 〈 0.0001), OVA (r = 0.55, P 〈 0.0001), cat (r = 0.5, P = 0.003) and BLG (r = 0.55, P = 0.001), but negatively correlated with neonatal IL-13 responses to both allergens tested (HDM: r = − 0.4, P = 0.03 and OVA: r = − 0.5, P = 0.001). Both neonatal and maternal IL-12 responses were positively correlated with postnatal IFN-γ responses to HDM at 12, 18 and 24 months of age (responses after age of 2 years were not assessed). There was no relationship between atopic risk and IL-12 capacity in the neonatal period, but there was a (non-significant) trend for neonatal IL-12 responses to be lower in the high-risk children who developed clinical allergy at 6 years (compared with the low risk group) although the number in this analysis was small.Conclusions Reduced APC IL-12 production in the perinatal period was associated with reduced T cell activation (lymphoproliferation), stronger neonatal Th2 responses, and weaker Th1 responses to allergen in the postnatal period. This supports the notion that variations in APC function in early life may contribute to altered allergen-specific cytokine responses associated with later allergy.

Notes: In this study a review of 1948 nipple discharge (ND) samples from 1530 patients in the age range of 18–83 years was undertaken to determine whether cytological findings from ND smears could provide useful diagnostic information regarding various breast lesions. The study included 1494 females and 36 males and was carried out during a period of 20 years 8 months. The clinical information in all patients was obtained from clinicians (coauthors†), medical records and a review of biopsies in 205 patients who had undergone surgery following the cytodiagnosis. Of the ND samples examined, 1480 were unilateral while 468 were from 234 bilateral ND. The cytodiagnoses were: benign 624, inadequate (despite two to three repeat samples) 492, inflammatory 96, papillary lesion not otherwise specified (NOS) 229, suspicious 22 (21 females, one male) and malignant 67 (63 females, four males). A breast biopsy in the 22 suspicious cases revealed breast carcinoma in 18 cases (females n = 17, male n = 1), atypical ductal hyperplasia (female n = 1), fibroadenoma (female n = 1) and a papilloma in two females. In the 67 cases with a diagnosis of malignancy 65 revealed a breast carcinoma in the biopsy (female n = 62, male n = 3) while one female was diagnosed as fibroadenoma and one male as florid gynaecomastia. In 63 cases (females n = 61; males n = 2) with clinical lumpy areas consistent with the diagnosis of fibrocystic condition in ND, the biopsy confirmed a fibrocystic process. In 53 of 229 cases with ND findings suggestive of a papillary lesion (NOS) the biopsy revealed a papilloma in 41 cases while in 12 cases no lesion was found. In the remaining cases of all the groups only a clinical follow-up and appropriate investigations were performed with no untoward outcome. Based on our study it is felt that cytological examination of ND smears seems to be a reasonably specific method in the diagnosis of malignant and suspicious cases but may be somewhat less specific for other diagnoses.