Polybrominated diphenyl ether (PBDE) concentrations in house dust are related to hormone levels in men

Despite documented widespread human exposure to polybrominated diphenyl ethers (PBDEs) through dietary intake and contact with or inhalation of indoor dust, along with growing laboratory evidence for altered endocrine function following exposure, human studies of PBDE exposure and endocrine effects remain limited. We conducted a preliminary study within an ongoing study on the impact of environmental exposures on male reproductive health. We measured serum hormone levels and PBDE concentrations (BDE 47, 99 and 100) in house dust from 24 men recruited through a US infertility clinic. BDE 47 and 99 were detected in 100% of dust samples, and BDE 100 was detected in 67% of dust samples, at concentrations similar to those reported in previous US studies. In multivariable regression models adjusted for age and BMI, there was a statistically significant inverse relationship between dust PBDE concentrations and free androgen index. Dust PBDE concentrations were also strongly and inversely associated with luteinizing hormone (LH) and follicle stimulating hormone (FSH), and positively associated with inhibin B and sex hormone binding globulin (SHBG). Finally, consistent with limited recent human studies of adults, PBDEs were positively associated with free T4. In conclusion, the present study provides compelling evidence of altered hormone levels in relation to PBDE exposures estimated as concentrations in house dust, and that house dust is an important source of human PBDE exposure, but more research is urgently needed.     

22-nm Half-pitch extreme ultraviolet node development at the SEMATECH Berkeley microfield exposure tool

Microfield exposure tools continue to play a dominant role in the development of extreme ultraviolet (EUV) resists. Here we present an update on the SEMATECH Berkeley 0.3-NA microfield exposure tool and summarize the latest test results from high-resolution line-space printing. Printing down to 20-nm is presented with large process latitude at 22-nm half-pitch lines. Also presented are line-edge roughness results along with a discussion of the importance of mask contributors to line-edge roughness measured in resist. Finally we briefly describe an upgrade to the tool that will enable EUV resist development at the 16-nm half-pitch node and beyond. (This paper was presented in MNE 2008 conference, <http://www.mne08.org>, <http://www.mne-conf.org>).     

Fractal dimension measurement of engineering surfaces

Many types of engineered surfaces have been observed to exhibit a fractal geometry. In some cases, modeling the generation of the surfaces predicts this and provides correlation between the dimension and history and properties of the surfaces. The complex process of machining precision surfaces does not yet lend itself to such detailed modeling, but observations of the correlations between production methods and surface dimension, independent of material type and hardness, offer encouragement.     

Study of MnAs as a Spin Injector for GaAs-Based Semiconductor Heterostructures

We report studies of two key factors involved in the use of MnAs as a spin injector, namely, Mn diffusion and spin injection properties when it is grown on GaAs-based semiconductor heterostructures. Depth profile of Mn concentration in a sample consisting of a MnAs film grown on GaAs is investigated with time-of-flight secondary ion mass spectroscopy. The result shows that Mn diffusion into GaAs is negligible, unlike the case of Ga_1?x Mn _x As/GaAs, in which Mn diffusion is significant. Meanwhile, robust spin injection is observed with MnAs as a spin injector for a GaAs-based light emitting diode, persisting up to room temperature.     

Investigations of the effects of gender, diurnal variation, and age in human urinary metabolomic profiles

Metabolomics may have the capacity to revolutionize disease diagnosis through the identification of scores of metabolites that vary during environmental, pathogenic, or toxicological insult. NMR spectroscopy has become one of the main tools for measuring these changes since an NMR spectrum can accurately identify metabolites and their concentrations. The predominant approach in analyzing NMR data has been through the technique of spectral binning. However, identification of spectral areas in an NMR spectrum is insufficient for diagnostic evaluation, since it is unknown whether areas of interest are strictly caused by metabolic changes or are simply artifacts. In this paper, we explore differences in gender, diurnal variation, and age in a human population. We use the example of gender differences to compare traditional spectral binning techniques (NMR spectral areas) to novel targeted profiling techniques (metabolites and their concentrations). We show that targeted profiling produces robust models, generates accurate metabolite concentration data, and provides data that can be used to help understand metabolic differences in a healthy population. Metabolites relating to mitochondrial energy metabolism were found to differentiate gender and age. Dietary components and some metabolites related to circadian rhythms were found to differentiate time of day urine collection. The mechanisms by which these differences arise will be key to the discovery of new diagnostic tests and new understandings of the mechanism of disease.     

Dynamic computational geometry on meshes and hypercubes

Parallel algorithms are given for determining geometric properties of systems of moving point-objects. The objects are assumed to be moving in a Euclidean space such that each coordinate of a point's motion is a polynomial of bounded degree in the time variable. The properties investigated include nearest (farthest) neighbor, closest (farthest) pair, collision, convex hull, diameter, and containment. Several of these properties are investigated from both the dynamic and steady-state points of view. Efficient, and often optimal, implementations of these algorithms are given for the mesh and hypercube.Research partially supported by a grant from the Niagara University Research Council.Research partially supported by National Science Foundation grants DCR-8608640 and IRI-8800514.     

Compact electro-thermal simulation of ESD-protection elements

Numerical simulations at the circuit level can improve the understanding of the behaviour of protection structures under system aspects. Full protection circuits with the influence of HBM ESD tester parasitics and additional parasitic elements in the circuitry have been investigated. Compact electro-thermal models for single protection elements (diodes and snapback nMOSFETs) have been developed. They help to explain differences between expected ESD-hardness and HBM-failure thresholds of protection structures.