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Using C60 molecule as a kind of surface-passivated agent to modify the electronic structure of Si nanocrystallites in porous silicon, we disclose that this kind of C60/nanocrystalline Si coupling system can show a strong blue emission at ∼460 nm when stored in air for more than one year. After a full characterization of the photoluminescence properties, we propose a luminescent center in the SiOx layer at the surface of a Si nanocrystallite. It is a pair consisting of an oxygen vacancy and an interstitial oxygen. The interstitial oxygen also forms a peroxy linkage with a neighboring lattice oxygen. Radiative recombination of carriers photogenerated from Si nanocrystallite cores in the luminescent centers results in the observed blue photoluminescence. Neutron irradiation experiments support our assignment of the blue emission mechanism. This work improves the understanding of the origin of blue emission from silicon/oxygen-related nanostructured materials. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Muscle specific RING finger protein-1 (MuRF1) is a member of the muscle specific RING finger protein family, and it is specifically expressed in cardiac and skeletal muscle tissues and is involved in myocyte differentiation, development and morphogenesis. In this study the complete open reading frame (ORF) of the porcine MuRF1 gene consisting of 354 amino acids was obtained and it shared 93% and 90% identity with those of the human and mice, respectively. Using the INRA radiation hybrid panel (IMpRH) technique, the MuRF1 gene was assigned to SSC6q closely linked to microsatellite markers SW1823 and SW709. The tissue distribution patterns revealed that MuRF1 mRNA was exclusively expressed in cardiac and skeletal muscle tissues. Real-time quantitative reverse transcriptase-polymerase chain reaction (RT-qPCR) results displayed that MuRF1 mRNA was up-regulated in Landrace pigs during the prenatal skeletal muscle development stages. A synonymous T/C single nucleotide polymorphism (SNP) was identified in MuRFI exon 3 and then a Hin61 PCR - RFLP was developed for SNP genotyping in two pig populations. Association of the genotypes with growth and carcass traits showed that different genotypes of MuRF1 were genetically significantly associated with average daily gain from birth to 90 kg and loin muscle area in one experimental population. The study suggested that the porcine MuRF1 gene might affect muscle growth and development, and could be a potential candidate gene for muscle production traits in the pig. [ABSTRACT FROM AUTHOR]

Objective: To observe the difference of pulmonary function among patients with dysphagia after stroke, patients without dysphagia and normal people, and to explore the correlation between swallowing function and pulmonary function. Methods: From September 2018 to April 2019, 310 stroke patients were enrolled from the rehabilitation department and neurology department of sun yat-sen memorial hospital, sun yat-sen university, of which 60 were selected as standard stroke patients. Pulmonary function of the three groups was assessed by pulmonary function detector and further compared. The swallowing function of the dysphagia group after stroke was examined by using videofluroscopic swallowing study (VFSS). The swallowing function was quantitatively assessed by Rosenbek penetration-aspiration scale (PAS), dysphagia outcome and severity scale (DOSS) and videofluoroscopy dysphagia scale (VDS), and the correlation between swallowing function and respiratory function was analyzed. Results: There were significant differences in pulmonary function among three groups ( P< 0.05). Besides the FEF25,FVC, FIVC between patients with dysphagia after stroke and patients without dysphagia, the FEF75 between patients without dysphagia and normal people (all P> 0.05), there were significant differences in the pairwise comparison of other indicators (all P< 0.05). There were correlations between PAS and MIP ( r= -0.618, P= 0.001),PAS and MEP ( r= -0.410, P= 0.038), PAS and PEF ( r= -0.443, P= 0.024), DOSS and MIP ( r= 0.602, P= 0.000),DOSS and MEP ( r= 0.496, P= 0.005), DOSS and PEF ( r= 0.553, P= 0.002), VDS and MEP ( r= -0.483, P= 0.012),VDS and PEF ( r= -0.494, P= 0.010), respectively. Conclusion: The pulmonary function of dysphagia patients after stroke decrease significantly, and the severity of dysphagia is correlated with the decrease of pulmonary function.

Effects of guanosine 5'-O-(3-thiotriphosphate) (GTP gamma S) and cations on 2-[125I]iodomelatonin binding were investigated in membrane preparations of the chicken spinal cord. At concentrations of 10 and 50 mumol/l, GTP gamma S dose-dependently increased (p < 0.05) the equilibrium dissociation constant (Kd) and depressed (p < 0.05) the maximum number of binding sites (Bmax). Na+ at a concentration of 125 mmol/l significantly increased (p < 0.05) the Kd and decreased (p < 0.05) the Bmax, and Mg2+ (2.5 mmol/l) significantly increased (p < 0.05) the Bmax without changes in Kd. In addition, Na+ and Mg2+ affected the interactions of GTP gamma S with melatonin receptors. In the spinal cord explants, melatonin (10 nmol/l) attenuated forskolin-stimulated cyclic AMP production by 53.1%, and preincubation with pertussis toxin abolished this effect of melatonin. These results suggest that the melatonin receptors in the chicken spinal cord are linked to its second messenger via a pertussis-toxin-sensitive guanine-nucleotide-binding protein, and that cations modulate these receptors. Our studies further support a previous hypothesis that melatonin exerts a direct action on spinal cord functions.