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The photovoltaic effect of the silicon (Si)/silicon carbide (SiC) quantum dot super lattice (QDSL) and multi-quantum well (QW) strucutres is presented based on numerical simulation and experimental studies. The QDSL and QW structures act as an intermediate layer in a p-i-n Si solar cell. The QDSL consists of a stack of four 4-nm Si nano disks and 2-nm SiC barrier layers embedded in a SiC matrix fabricated with a top-down etching process. The Si nano disks were observed with bright field-scanning transmission electron microscopy. The simulation results based on the 3D finite element method confirmed that the quantum effect on the band structure for the QDSL and QW structures was different and had different effects on solar cell operation. The effect of vertical wave-function coupling to form a miniband in the QDSL was observed based on the solar-cell performance, showing a dramatic photovoltaic response in generating a high photocurrent density Jsc of 29.24 mA/cm2, open circuit voltage Voc of 0.51 V, fill factor FF of 0.74, and efficiency η of 11.07% with respect to a i-QW solar cell with Jsc of 25.27 mA/cm2, Voc of 0.49 V, FF of 0.69, and η of 8.61% and an i-Si solar cell with Jsc of 27.63 mA/cm2, Voc of 0.55 V, FF of 0.61, and η of 10.00%. A wide range of photo-carrier transports by the QD arrays in the QDSL solar cell is possible in the internal quantum efficiency spectra with respect to the internal quantum efficiency of the i-QW solar cell. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The aim of the present study using near-infrared spectroscopy (NIRS) is to evaluate the correlation of cerebral (parieto-temporal lobe) hemoglobin changes and vertiginous sensation during unilateral caloric stimulation. During the hot water (44° C) stimulus, cerebral hemoglobin was increased bilaterally, but it was dominant ipsilaterally. During the unilateral cold water (30° C) stimulus, cerebral hemoglobin was decreased on both sides, especially on the ipsilateral side. Vertigious sensation was strong in cases with marked left-right difference of cerebral hemoglobin changes. The usefulness of NIRS to investigate the relationship between peripheral vestibular organ and vestibular cortex was verified. [ABSTRACT FROM AUTHOR]

The cyclin-dependent kinase (CDK) inhibitor p21Waf1/CiP1/Sdi1 was identified initially as a gene induced in senescent cells and itself has been shown to cause permanent growth arrest/senescence. Reactive oxygen species (ROS), a byproduct of oxidative processes, can also induce an irreversible growth arrest similar to senescence. Here we show that p21 increased intracellular levels of ROS both in normal fibroblasts and in p53-negative cancer cells. N-acetyl-L-cysteine, an ROS inhibitor, rescued p21-induced senescence, showing that ROS elevation is necessary for induction of the permanent growth arrest phenotype. p16Ink4a, a CDK4- and CDK6-specific inhibitor, failed to increase ROS levels, and cell cycle arrest induced by p16 was reversible following its down-regulation, demonstrating the specificity of this p21 effect. A p21 mutant that tacked the ability to bind proliferating cell nuclear antigen (PCNA) retained the ability to induce both ROS and permanent growth arrest. All of these findings establish that p21 mediates senescence by a mechanism involving ROS accumulation which does not require either its PCNA binding or the CDK inhibitory functions shared with p16. [ABSTRACT FROM AUTHOR]

This is the first complete report on the histopathologic study of the temporal bones from an infant with a well-documented Pierre Robin syndrome (micrognathia, glossoptosis and cleft palate), demonstrating multiple middle and inner ear anomalies. The anomalies are basically architectural malformations rather than neural or end organ developmental anomalies. The anomalies in this case, except for a few points, are somewhat similar in both ears. Multiple anomalies include: abnormal narrowing of the cms commune-utricle junction, superiorly located cms commune and posterior semicircular canal, underdeveloped modiolus, absence of the bony septum between the middle and apical coil (existence of scala communis in left ear), abnormally small internal auditory meatus, and abnormal direction of internal auditory canal, large cartilaginous mass around the superior semicircular canal and in the tympanic end of the fissula ante fenestram, small facial nerve, large facial bony canal dehiscence, anomalic stapes, etc. [ABSTRACT FROM AUTHOR]

A pair of temporal bones obtained from a thoracopagus conjoined twin revealed malformation of the facial nerve and vestibular fenestra (oval window) on one side, and underdeveloped petrous bone and aplastic inner ear apparatus on the other. [ABSTRACT FROM AUTHOR]

Pilots and astronauts experience fluid shifts in variable gravity. Acute effects of fluid shifts on the cardiovascular system were monitored on NASA's KC-135 aircraft during parabolic flight The variability of R-R intervals in the electrocardiogram was measured as an indication of vagal cardiac neural activity. R-R intervals were measured during the gravity transition from 2-G to 0-G produced by parabolic flight to assess the involvement of the autonomic nervous system in regulating the acute effects of fluid shifts. In seven subjects, a BoMed noninvasive continuous cardiac output monitor (NCCOM 3) monitored thoracic fluid index (TFI, ohms), heart rate (bpm), and cardiac output (1/min). Data were stored on a lap-top computer with the subject in one of four postures: sitting, standing, supine, and semi-supine, during one of four sets of eight to ten parabolas. Five seconds of data were averaged: before parabola onset (1.3-G); parabola entry (1.9-G); 0-G; and parabola exit (1.7-G). Three to eight parabolas were averaged for subjects in each posture; the mean for each posture was calculated. In each of five additional subjects, the coefficient of variation was calculated by dividing mean value by the standard deviation of 3 to 15 R-R intervals. Eight to ten parabolas were averaged for each postural set. Compared with values collected before 0-G, standing values during 0-G showed that the thoracic fluid index decreased 2.5 ohms, heart rate decreased 22 bpm, and cardiac output increased 1 L/min. During sitting, thoracic fluid index decreased 1.25 ohms, heart rate decreased 10 bpm, whereas cardiac output increased 0.5 L/min. In the supine position, thoracic fluid index and heart rate were constant whereas cardiac output decreased 0.55 L/min. In the semi-supine position, thoracic fluid index and heart rate were constant. Compared with values collected from 2-G and 0-G the coefficient of variation increased 66.4% in the standing position, 53.4% in the sitting position, and 43.3% in the semi-supine position and decreased 11.6% in the supine position. The data indicated that cardiovascular changes are dependent on posture and gravity. During the four sets of parabolas in the four different postures, the greatest and smallest changes were observed in the standing and supine positions, respectively, during 0-G. Fluid shifts from the legs to the thorax occurred during 0-G in the supine and standing positions. The high values of the coefficient of variation at the onset of 0-G suggest that vagal cardiac neural activity increases, but not significantly, in all positions except supine. [ABSTRACT FROM AUTHOR]

Equilibrium disturbances may occur after neck lesions such as whiplash injuries. Abnormal proprioceptive inputs and vascular changes which involve not only the peripheral labyrinth, but also the brain stem are major factors producing these disturbances. Neck proprioceptor ablation was performed in healthy young adult squirrel monkeys by unilateral section of C1, C2 dorsal roots, or by injection of 1 cc of 1 percent Xylocaine® without epinephrine into the unilateral deep neck region. The dorsal root section was histologically confirmed by investigating spinal ganglion and adjacent nerve tissues. The Nauta stained spinal cord cross sections showed neuronal degeneration coming from the dorsal root. No spontaneous nystagmus was observed in the present series after section of the C1, C2 dorsal roots or Xylocaine® injection. After the Xylocaine® deep neck injection, the slow phase eye speed of optokinetic nystagmus declined in either direction in all animals. Slight decline of the quick component was also noticed. The wave form was also changed. The decline of slow phase eye speed partly represents the ablative effect of neck proprioceptors (joints, ligaments, and muscles), although the effect produced through other channels or by systemic toxicity cannot be eliminated. After the left C1, C2 dorsal root section, the slow phase eye speed declined only when there was clockwise stimulation. Statistical studies suggested significant differences between pre- and postoperative status. This finding suggested that the cervical input is connected to the oculo-oculomotor pathway. Immediately after left C1, C2 dorsal root section, a reduction of the slow phase eye speed of postrotatory nystagmus occurred after counter-clockwise rotation. The randomization test was used, and it was found that the postoperative scores are significantly lower than the pre-operative scores. After the ablation of C1, C2 dorsal root, subjects failed to demonstrate any significant change in the pattern or numbers of pendular rotation nystagmic responses. On the other hand, three monkeys after Xylocaine® deep neck injection showed some change. The present experimental results indicate that the slow phase eye speed is a proper nystagmic parameter to study the neck proprioceptor contribution to oculomotor function. All animals after unilateral C1, C2 dorsal root section in the present series demonstrated moderate dysequilibrium (measured by the squirrel monkey rail test) confirming that neck injury can produce ataxia. There was no clear postoperative directional dominance of falls. For the diagnosis or investigation of the prognosis of many cervical disorders, bodily equilibrium examination is also important in addition to studying oculomotor function. [ABSTRACT FROM AUTHOR]