University of Rochester

About: University of Rochester is a education organization based out in Rochester, New York, United States. It is known for research contribution in the topics: Population & Laser. The organization has 63915 authors who have published 112762 publications receiving 5484122 citations. The organization is also known as: Rochester University.

Electronic States and Luminescence in Porous Silicon Quantum Dots: The Role of Oxygen

Abstract: Depending on the size, the photoluminescence (PL) of silicon quantum dots present in porous silicon can be tuned from the near infrared to the ultraviolet when the surface is passivated with Si-H bonds. After exposure to oxygen, the PL shifts to the red by as much as 1 eV. This shift and the changes in PL intensity and decay time, show that both quantum confinement and surface passivation determine the electronic states of silicon quantum dots. A theoretical model in which new electronic states appear in the band gap of the smaller quantum dots when a Si-O bond is formed, is in good agreement with experiments. This result clarifies the controversy regarding the PL mechanisms in porous silicon.

Cell and environment interactions in tumor microregions: the multicell spheroid model

Abstract: Abnormal vascularization of malignant tumors is associated with the development of microregions of heterogeneous cells and environments. Experimental models such as multicell spheroids and a variety of new techniques are being used to determine the characteristics of these microregions and to study the interactions of the cells and microenvironments. The special cellular microecology of tumors influences responsiveness to therapeutic agents and has implications for future directions in cancer research.

Unified huntington’s disease rating scale: Reliability and consistency

Abstract: The Unified Huntington's disease Rating Scale (UHDRS) was developed as a clinical rating scale to assess four domains of clinical performance and capacity in HD: motor function, cognitive function, behavioral abnormalities, and functional capacity. We assessed the internal consistency and the intercorrelations for the four domains and examined changes in ratings over time. We also performed an interrater reliability study of the motor assessment. We found there was a high degree of internal consistency within each of the domains of the UHDRS and that there were significant intercorrelations between the domains of the UHDRS, with the exception of the total behavioral score. There was an excellent degree of interrater reliability for the motor scores. Our limited longitudinal database indicates that the UHDRS may be useful for tracking changes in the clinical features of HD over time. The UHDRS assesses relevant clinical features of HD and appears to be appropriate for repeated administration during clinical studies.

The effects of instructors' autonomy support and students' autonomous motivation on learning organic chemistry: A self-determination theory perspective

Abstract: This prospective study applied self-determination theory to investigate the effects of students' course-specific self-regulation and their perceptions of their instructors' autonomy support on adjustment and academic performance in a college-level organic chemistry course. The study revealed that: (1) students' reports of entering the course for relatively autonomous (vs. controlled) reasons predicted higher perceived competence and interest/enjoyment and lower anxiety and grade-focused performance goals during the course, and were related to whether or not the students dropped the course; and (2) students' perceptions of their instructors' autonomy support predicted increases in autonomous self-regulation, perceived competence, and interest/enjoyment, and decreases in anxiety over the semester. The change in autonomous self-regulation in turn predicted students' performance in the course. Further, instructor autonomy support also predicted course performance directly, although differences in the initial level of students' autonomous self-regulation moderated that effect, with autonomy support relating strongly to academic performance for students initially low in autonomous self-regulation but not for students initially high in autonomous self-regulation. © 2000 John Wiley & Sons, Inc. Sci Ed84:740–756, 2000.