Novel anti‐tumor mechanism of galanin receptor type 2 in head and neck squamous cell carcinoma cells

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/102710/1/cas12315.pd

Desempeños del alumnado de Educación Secundaria en la evaluación de una investigación científica en el contexto de la industria láctea

En este estudio se analizan los desempeños de estudiantes de 2.º, 3.º y 4.º de ESO (14, 15 y 16 años) que cursan la asignatura de Física y química, cuando evalúan el diseño de una investigación sobre un problema de precipitación identificado en la industria láctea. Los desempeños se examinan por separado para cada dimensión del diseño: identificación de la cuestión objeto de investigación, formulación de hipótesis, planificación de la investigación y selección del criterio de finalización. Para el análisis de resultados, se recogen sus propuestas, en las que han de estar desarrolladas las siguientes tareas: seleccionar la mejor opción, justificar su elección y modificar la opción alternativa para convertirla en correcta. Los resultados menos adecuados corresponden a las dos últimas dimensiones citadas.In this paper we analyse the performance of 8th, 9th and 10th grade students (14, 15 and 16 years old respectively), attending Physics and Chemistry lessons, when assessing the design of scientific research on a precipitation problem identified in the dairy industry. Students' performances are examined separately for each dimension involved in the design: identifying the issue to be studied, posing the hypotheses, planning the research and selecting the ending criterion. For the analysis, we collect participants' individual proposals, which have to include the following tasks: selecting the best option, justifying their choice and modifying the alternative option so that it will be correct. The less adequate results correspond to the last two dimensions

Persistent High Polarization of Excited Spin Ensembles During Light Emission in Semiconductor Quantum-Dot-Well Hybrid Nanosystems

We demonstrate persistent high degrees of spin polarization (SPD) up to 70% during light emission in (In1-xGax) As quantum-dot-well (QD-QW) hybrid nanosystems, where QD excited states are laterally tunnel coupled through the adjacent two-dimensional QW potential depending on the QW thickness. Spinpolarized electrons are photo-excited by using circularly polarized light pulses. The decay time of spin relaxation, obtained by that of the SPD, is 70 times larger than the photoluminescence decay time. The temporally constant SPD is sustained by a selective transfer of minority spins among QDs after flipping from the majority spins, which is promoted by a moderate state filling of lower-energy spin sublevels in surrounding QDs. The spin transfer times are deduced as functions of the QW thickness and excited-spin density. These results can provide a precise control of lateral interdot spin-transfer dynamics and resultant suppression of spin relaxation in QD ensembles

Interdot carrier and spin dynamics in a two-dimensional high-density quantum-dot array of InGaAs with quantum dots embedded as local potential minima

Interdot carrier and spin dynamics were studied in a two-dimensional array of high-density small quantum dots (SQDs) of InGaAs with an average diameter of 16 nm and a sheet density of 1.2 x 10(11) cm(-2), in which 24 nm diametric large QDs (LQDs) were embedded as local potential minima. We observed a delayed photoluminescence (PL) rise from the lower-lying LQD states and a considerably faster PL decay from the higher-lying SQD states, indicating carrier transfer from the two-dimensionally coupled SQDs into the LQDs. In addition, inverse carrier tunneling from the LQDs into the SQDs was thermally induced, which is characterized by the thermal activation energy between the LQDs and SQDs. Moreover, circularly polarized transient PL behavior from the SQD states exhibits a suppression of the spin polarization decay in the initial time region, depending on the excited spin density. This tentatively suppressed spin relaxation can be quantitatively explained by selective interdot transfer of minority-spin electrons from the SQDs into LQDs, when the majority spin states in both QDs are sufficiently populated by excited spins. These findings indicate that the high-density SQDs behave as the main emitters with suppressed spin relaxation, while the scattered LQDs with lower potential behave as the receivers of minority-spin electrons

Interdot spin transfer dynamics in laterally coupled excited spin ensemble of high-density InGaAs quantum dots

Interdot spin transfer dynamics is studied in a laterally coupled excited spin ensemble of high-density InGaAs quantum dots (QDs). We observe a rise time of the photoluminescence intensity of similar to 100 ps and a simultaneous increase in the spin polarization of the excited spin ensemble, indicating spin injection from higher-energy levels in smaller QDs. Moreover, this coupled ensemble exhibits decay properties of the spin polarization that vary with the excited spin density. This phenomenon can be quantitatively understood by considering interdot spin transfer into lower-energy levels of the surrounding QDs, where the transfer rate depends on the degree of state filling of each QD level. Published by AIP Publishing

Acidogenicity of Streptococcus mutans at Different pH Conditions in a Chemostat.

This study was presented at the Rochester AADR Winter Meeting, March 1991