In this paper, based on the phonon-exciton mechanism, the superconductivity of yttrium barium copper oxide (YBCO) system is explained. The transition temperature (Tc) 's formula is derived by the extended BCS-Eliashberg theory, i.e. phonon-exciton mechanism and McMillan's energy gap function, and the Tc's expressions isreduced by using the Einstein spectrum. Last, the calculating method of element metal effective phonon spectrum is used to the high Tc cuprate YBCO system by using a crystal average atom approximation model. The theoretical analysis and calculational results show that the superconductivity of high Tc YBCO system maybe described by phonon-exciton model.

Objective To investigate the long-term effect of inflammation on behavior,microglias and dopaminergic (DA) neurons in the substantia nigra of intracephalic inflammation rat models induced by intracerebroventricular injection of low-dose(10μg) lipopolysaccharide (LPS).To analyze the relationship between activation of microglias and DA neurons degeneration in order to explore the mechanism of inflammation in the progressive process of Parkinson' s disease (PD).Methods 50 healthy male SD rats were randomly assigned into saline-injected control group and 10μg LPS-injected group.All injections were made intracerebroventricularly on right side of rats with saline or LPS.Moving speed was measured at different time points.At 24 weeks and 40 weeks after saline or LPS injection,specific antibodies of OX-42 and OX-6 were used separately to detect the changes of microglia in the substantia nigra of rat.The changes in morphology and numbers of substantia nigra DA neurons were observed by tyrosine hydroxylase(TH) immunohistochemical staining.The expression and distribution of the degenerated neurons in substantia nigra were detected by using Fluoro-Jade B(FJB).Results ①Analysis of moving speed sho wed that the moving speed of 10μg LPS-injected group rats and saline-injected group rats was similar from 4 weeks to 36 weeks after injection.At 40 weeks post injection,moving speed of 10μg LPS-injected group rats decreased by 24.6％ compared with that of saline-injected group rats (P＞ 0.05 ).②At 24 weeks and 40 weeks after injection,there were many activated OX-42 positive microglias in the substantia nigra of 10μg LPS-injected group rats,but there was almost no significant activated OX-42 positive microglia in saline-injected group.OX-6 positive microglias were not found in the substantia nigra of both of two groups.③At 24 weeks and 40 weeks post injection,the number of TH-positive neurons in the substantia nigra of 10μg LPS-injected group rats decreasedby 24.2％ ( t=4.803,P＜0.01) and 27.6％ ( t=3.212,P＜0.01) respectively compared with those of salineinjected group.④ There was no FJB positive neurons in the substantia nigra of the two group rats.Conclusion Intraventricular injection of low-dose LPS ( l0μg) in rats may induce long-term activation of microglias and chronic degeneration of DA neurons in the subs tantia nigra of rats although the necrosis are not occurs to DA neurons till 40 weeks post LPS injection.Intraventricular injection of low-dose LPS in rats could be ideal model to study the mechanism of chronic degeneration of DA neurons in PD.

Infectious stones are produced by urease producing microorganisms, which have a fast generation rate, high recurrence and mortality rates, and are prone to complications related to infection. At present, the treatment of infectious stones includes surgical treatment and drug treatment, and the research on its treatment methods has become one of the hotspots in the field of urology. This article provides a review of the research progress in the treatment of infectious stones, with the aim of improving understanding of the treatment of infectious stones.

Objective:To explore the value of nomogram based on dual-energy CT (DECT) enhanced imaging in predicting postoperative recurrence-free survival (RFS) of early-stage glottic carcinoma (EGC).Methods:The clinicopathological and DECT data of patients with EGC confirmed by pathology in the Tianjin First Central Hospital from January 2015 to July 2018 were analyzed retrospectively. A total of 178 patients were enrolled, including 162 males and 16 females, with the age from 44 to 86 (62±9) years old. According to the follow-up data, the patients were divided into recurrent group ( n=32) and non-recurrent group ( n=146). The differences of clinicopathological data and DECT iodine maps parameters between the two groups were analyzed using χ 2 test, independent-sample t test and Mann-Whitney U test. The survival related cut-off values of the quantitative data between the two groups were selected by X-tile software. The survival curve was drawn using Kaplan-Meier method, and the difference of survival rate was tested with log-rank analysis. The variables with statistical differences were included in the Cox proportional hazard model for multivariate analysis to select the independent predictors of postoperative RFS. Based on the multivariate Cox analysis, the nomogram was drawn to predict the RFS at 1, 2 and 5 years. The prediction efficiency and clinical benefit of the nomogram were evaluated by C-index, calibration curve and decision curve analysis. Results:The median follow-up time was 24.3 months, ranging from 2 to 63 months. There was a significant difference in T-stage between recurrent and non-recurrent groups (χ2=9.21, P=0.002). The prognostic cutoff values obtained by X-tile software were arterial phase standardized iodine concentration (SIC AP)=0.28 and venous phase standardized iodine concentration (SIC VP)=0.87. The results of log-rank test showed that there were significant differences in RFS among patients with different T-stage, SIC AP and SIC VP (χ2=10.74, 15.50, 17.97, P=0.001,<0.001,<0.001). T-stage, SIC AP and SIC VP were identified as independent predictors of postoperative RFS (hazard ratio=2.271, 3.552, 3.266, P=0.026,<0.001, 0.003). The C-index of the nomogram combined with DECT parameter and T-stage was 0.785, which was higher than that of T-stage alone (0.622). The calibration curve showed that there was good consistency between the actual and predicted probability of the sample. The decision curve analysis showed that the clinical benefit of the nomogram was higher than that of the T-stage alone. Conclusion:The nomogram based on preoperative clinical factors (T-stage) and DECT iodine map factors (SIC AP and SIC vp) can predict the postoperative RFS of patients with EGC.

OBJECTIVETo introduce the application and clinical effect of self-made liver fixing device in laparoscopic radical gastrectomy.

METHODSClinical data of 469 patients underwent laparoscopic radical gastrectomy in Nanfang Hospital, Southern Medical University from March 2014 to January 2017 were analyzed retrospectively. In laparoscopic radical gastrectomy, self-made liver fixing device was used to expose surgical field covered by hepatic lobe in gastric lesser curvature and hepatic flexure of colon. Manufacture of the self-made liver fixing device: appropriate length of the catheter was cut according to the size of liver; the lotus suture needle with a thread was put through two catheters to connect them. Then the prepared liver fixing device was sent into abdominal cavity through a 12-mm Trocar hole with needle holder and was fixed on the free hepatic lateral hepatogastric ligament with hemo-lock. Finally the application effect of the liver fixing device was evaluated by reviewing the surgical videos.

RESULTSA mean time of 40.3 seconds was required to complete liver fixing by using the self-made liver fixing device in laparoscopic radical gastrectomy and liver did not slip down in all the cases. Liver secondary manual fixing by assistants was 2 times averagely. Three cases had mild liver injury.

CONCLUSIONThe self-made liver fixing device in laparoscopic radical gastrectomy is easy to operate and can effectively expose sufficient surgical field, with high security and convenient materials.