RESUMEN
Solution-processed organic-inorganic perovskites are fascinating due to their remarkable photo-conversion efficiency and great potential in the cost-effective, versatile and large-scale manufacturing of optoelectronic devices. In this paper, we demonstrate that the perovskite nanocrystal sizes can be simply controlled by manipulating the precursor solution concentrations in a two-step sequential deposition process, thus achieving the feasible tunability of excitonic properties and lasing performance in hybrid metal-halide perovskites. The lasing threshold is at around 230 µJ cm-2 in this solution-processed organic-inorganic lead-halide material, which is comparable to the colloidal quantum dot lasers. The efficient stimulated emission originates from the multiple random scattering provided by the micro-meter scale rugged morphology and polycrystalline grain boundaries. Thus the excitonic properties in perovskites exhibit high correlation with the formed morphology of the perovskite nanocrystals. Compared to the conventional lasers normally serving as a coherent light source, the perovskite random lasers are promising in making low-cost thin-film lasing devices for flexible and speckle-free imaging applications.
RESUMEN
A promising method to promote the lasing performance of solution-processed organic-inorganic lead-halide perovskites has been demonstrated. With the adding Ag and PMMA thin films, the threshold excitation power for low-temperature lasing action in perovskites can be greatly reduced by over two orders of magnitude than that acquired in bare perovskite layers, ascribing to the strong exciton-plasmon coupling between the Ag and perovskite films. Also, the PMMA layer can be exploited to prevent the perovskite degradation from the hydrolysis in ambient environment, achieving long-lasting light-emitting performance. The advantages exhibited by the hybrid perovskite configuration would be very promising in making practical laser devices.
RESUMEN
Objective To detect the mecA gene and tst gene of toxic shock syndrome toxin 1 (TSST-1)of Staphylococcus aureus by using PCR and to learn the carrier condition of tst gene.Methods The mecA gene and tst gene of Staphylococcus aureus strains that isolated from clinical sources in our hospital during August 2006 to May 2007 were amplified in vitro using PCR,and to establish the rapid,specific,and sensitive method of detecting tst gene of methicillin resistant Staphylococcus aureus(MRSA).Results The mecA gene and tst gene were detected,and were made the gene sequencing successfully.Forty-one of 84 strains had mecA gene(48.81%),16 of 84 strains had tst gene(19.05%),10 of 84 strains had both of them,and the positive rate was 24.39%(10/41).Conclusion The proportion of tst gene positive strains of MRSA iS high in clinic,and it must be paid more attention.
RESUMEN
Objective To investigate the effect of total gastrectomy for gastric malignancy(GM). Methods The clinical data of total gastrectomy in 113 patients with GM were analysed retrospectively. Results Radical total gastrectomy was performed in 97 cases, palliative total gastrectomy in 16 cases, combined with resection of head or tail of pancreas, splenectomy, transverse colectomy or parital hepatectomy in 19 cases. Reconstruction of digestive tract : Roux-en-Y esophagojejunostomy in 26 cases, Braun esophagojejunostomy in 19 cases, Roux-en-Y jejunal p-type anastomosis in 68 cases, Postopterative complications occurred in15 cases,including pancreatic fistula in one cases,anastomostic leakage in 3; operative death was happened in 2 cases. 86 patients (76%)have been followed up, the postoperative 1-,3-,5-year survival rate in radical total gastrectomy, combined resection organs and palliative total gastrectomy was 77.9％,45.7％,37.2％;88.8％,55.5％,33.3％; and 80％,0％,0％ respectively. Conclusions The effect of total gastrectomy for gastric malignancy can be successful, if the indications are stricted and combined with rational viscers resection.
RESUMEN
Objective To investigate the effect of total gastrectomy for gastric malignancy(GM). Methods The clinical data of total gastrectomy in 113 patients with GM were analysed retrospectively. Results Radical total gastrectomy was performed in 97 cases, palliative total gastrectomy in 16 cases, combined with resection of head or tail of pancreas, splenectomy, transverse colectomy or parital hepatectomy in 19 cases. Reconstruction of digestive tract : Roux en Y esophagojejunostomy in 26 cases, Braun esophagojejunostomy in 19 cases, Roux en Y jejunal p type anastomosis in 68 cases, Postopterative complications occurred in15 cases,including pancreatic fistula in one cases,anastomostic leakage in 3; operative death was happened in 2 cases. 86 patients (76%)have been followed up, the postoperative 1 ,3 ,5 year survival rate in radical total gastrectomy, combined resection organs and palliative total gastrectomy was 77.9%,45.7%,37.2%;88.8%,55.5%,33.3%; and 80%,0%,0% respectively. Conclusions The effect of total gastrectomy for gastric malignancy can be successful, if the indications are stricted and combined with rational viscers resection.