Publications

Implantable neuroelectronic interfaces have enabled significant advances in both fundamental research and treatment of neurological diseases, yet traditional intracranial depth electrodes require invasive surgery to place and can disrupt the neural networks during implantation. To address these limitations, we have developed an ultra-small and flexible endovascular neural probe that can be implanted into small 100-micron scale blood vessels in the brains of rodents without damaging the brain or vasculature. The structure and mechanical properties of the flexible probes were designed to meet the key constraints for implantation into tortuous blood vessels inaccessible with existing techniques. In vivo electrophysiology recording of local field potentials and single-unit spikes has been selectively achieved in the cortex and the olfactory bulb. Histology analysis of the tissue interface showed minimal immune response and long-term stability. This platform technology can be readily extended as both research tools and medical devices for the detection and intervention of neurological diseases.

No abstract is provided for this article.

'Polypropylene Carbonate (PPC)' published in 'Encyclopedia of Nanotechnology'

We report a general approach for the synthesis of single-crystal silicon nanotubes, involving epitaxial deposition of silicon shells on germanium nanowire templates followed by removal of the germanium template by selective wet etching. By exploiting advances in the synthesis of germanium nanowires, we were able to rationally tune the nanotube internal diameters (5-80 nm), wall thicknesses (3-12 nm), and taper angles (0-9°) and additionally demonstrated branched silicon nanotube networks. Field effect transistors fabricated from p-type nanotubes exhibited a strong gate effect, and fluid transport experiments demonstrated that small molecules could be electrophoretically driven through the nanotubes. These results demonstrate the suitability of silicon nanotubes for the design of nanoelectrofluidic devices.

Higher intake of a Western dietary pattern may be associated with a higher risk of recurrence and mortality among patients with stage III colon cancer treated with surgery and adjuvant chemotherapy. Further studies are needed to delineate which components of such a diet show the strongest association.

Two luminescent ruthenium complexes containing tripod-type end groups linked through a rigid spacer to a phenanthroline derivative, able to confer an axial geometry to the complexes, are described. One of the compounds is functionalized with thioacetate groups in order to link the metal complex to metallic surfaces. The photophysical and electrochemical behavior of the complexes are studied in solution and on conductive substrates and, furthermore, self-assembled monolayers are investigated in a junction using gold and an indium gallium eutectic, as electrodes, and by time-resolved confocal microscopy. The results show that the complexes form very stable and well-ordered monolayers because of the tripod system, which can anchor the complex almost perpendicular to the surfaces.

No abstract is provided for this article.

Introduction: It remains unclear whether circulating testosterone and sex hormone-binding globulin (SHBG) are associated with cardiometabolic disease risk and mortality. Hypothesis: Higher SHBG and lower testosterone levels are associated with reduced risk of incident type 2 diabetes (T2D), cardiovascular disease (CVD), and all-cause mortality in women. Methods: Baseline testosterone and SHBG measures were available on 11,314 women from the Nurses’ Health Study I and II, who were part of 9 separate nested case-control studies and were free of CVD, T2D, and cancer at study baseline. Total testosterone was assayed by a radioimmunoassay or liquid chromatography tandem mass spectrometry; SHBG was measured by an immunoassay. Free testosterone was calculated based on a standard clinical formula. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox regressions, adjusted for study design characteristics, established risk factors and confounders including menopausal statues, hormone therapy, and continuous body mass index. Results: During up to 22 years of follow-up (215,120 person-years), 891 incident T2D cases, 1,089 CVD cases (fatal myocardial infarction, nonfatal coronary heart disease, and fatal/nonfatal stroke), and 1,818 deaths occurred. In multivariable analyses, circulating SHBG levels were inversely associated with incident T2D (comparing the highest to lowest quartiles, HR [95% CI]: 0.34 [0.24-0.47]; P trend <0.001) and all-cause mortality (HR: 0.78 [0.65-0.95]; P trend =0.03). Total testosterone was inversely associated with T2D (HR: 0.71 [0.53-0.96]; P trend =0.04), while free testosterone was positively associated with T2D (HR: 1.99 [1.44-2.75]; P trend <0.001) and all-cause mortality (HR: 1.22 [1.00-1.48]; P trend =0.02). No association was observed between SHBG, nor free or total testosterone and CVD. Conclusions: Lower circulating levels of SHBG and higher levels of free testosterone were associated with increased risk of T2D and all-cause mortality, but not CVD, in women.

The objective of this study was to describe the temperament dimension profiles assessed by the Temperament and Character Inventory (TCI) among young adults with the DSM-III-R personality disorder (PD). Our hypothesis was that PD clusters and separate PDs can be distinguished from one another by their specific temperament profiles. As a part of the 31-year follow-up survey of the prospective Northern Finland 1966 Birth Cohort, the cohort members living in the city of Oulu at the age of 31 years (n=1609) were invited to participate in a two-phase field study. The Structured Clinical Interview for DSM-III-R for PDs (SCID–II) was used as diagnostic instrument. The final study sample consisted of the 1311 subjects who had completed the Hopkins Symptom Check List-25 questionnaire for screening and had given a written informed consent. Of the 321 SCID interviewed subjects, 74 met the criteria for at least one PD and had completed the TCI. The mean TCI scores of subjects with PD and control subjects without PD (n=910) were compared. Low Novelty Seeking, high Harm Avoidance and low Reward Dependence characterized cluster A and C PDs. Subjects with a cluster B PD did not differ from controls, except for Novelty Seeking, which was high. The temperament dimensions could not distinguish different PDs very well, with the only exception of persons with obsessive–compulsive PD. PD clusters were associated with different profiles of temperament, lending some support for Cloninger's typology.