Strategies for Management of Peritoneal Dialysis Patients in Singapore during COVID-19 Pandemic.

Peritoneal dialysis (PD) is the only well-established home-based dialysis therapy in Singapore. As it is a home-based modality, PD should be considered as a preferred mode of kidney replacement therapy (KRT) for patients with kidney failure during this COVID-19 pandemic as it avoids frequent visits to hospitals and/or satellite dialysis centres. The highly infectious nature of this virus has led to the implementation of the Disease Outbreak Response System Condition orange status in Singapore since early February 2020. This paper summarises the strategies for management of several aspects of PD in Singapore during this COVID-19 pandemic, including PD catheter insertion, PD training, home visit and assisted PD, outpatient PD clinic, inpatient management of PD patients with or without COVID-19 infection, PD as KRT for COVID-19 patients with acute kidney injury, management of common complications in PD (peritonitis and fluid overload), and management of PD inventory.

[Influence of different surface treatments on porcelain surface topography].

OBJECTIVE: To evaluate the influence of different surface treatments on porcelain surface topography. METHODS: Metal ceramic prostheses in 6 groups were treated according to the different surface treatment methods, and the surface topography was observed through scanning electron microscope (SEM). Group A was the control one (untreated), group B was etched by 9.6% hydrofluoric acid(HF), group C was deglazed by grinding and then etched by 9.6% HF, group D was treated with Nd: YAG laser irradiation(0.75 W) and HF etching, group E was treated with Nd: YAG laser irradiation (1.05 W) and HF etching, and group F was treated with laser irradiation (1.45 W) and HF etching. RESULTS: Surface topography was different in different groups. A lot of inerratic cracks with the shapes of rhombuses and grid, and crater with a shape of circle were observed on the ceramic surface after treatment with energy parameters of 1.05 W Nd: YAG laser irradiation and 9.6% HF etching (group E). Surface topography showed a lot of concaves on the inner wall of the cracks, and the concaves with diameter of 1-5 microm could be observed on the inner wall of the holes, which had a diameter of 20 microm under SEM. CONCLUSION: The use of Nd: YAG laser irradiation with the energy parameters of 1.05 W and the HF with a concentration of 9.6% can evenly coarsen the porcelain surface, that is an effective surface treatment method.

[Sutural physical model building in the three-dimensional finite-element model of maxillofacial bones].

OBJECTIVE: To build the physical model of four suturae which are related to the growth of maxilla in the three-dimensional finite-element model of maxillofacial bones. METHODS: A 16 years old volunteer with individual normal occlusion, good periodontium health condition and without diseases of temporomandibular joint was chosen to be the material of modeling. The three-dimensional finite-element model of the volunteer's maxillofacial bones was built using the CT scan and the finite-element modeling method. Finally we built the physical model of four suturae which were related to the growth of maxilla in the model of maxillofacial bones. RESULTS: The model of maxillofacial bones with 86,575 nodes and 485,915 elements was generated. This model contained four suturae including sutura frontomaxillaris, sutura zygomaticomaxillaris, sutura temporozygomatica and sutura pterygopalatine. CONCLUSION: A three-dimensional finite-element model of maxillofacial bones with good biological similarity was developed.