Studies on the GS impregnated calcium sulfate implants / 生物医学工程学杂志

The gentamicin sulfate carried calcium sulfate (GSCS) implants were fabricated by the coagulating method, and the release rate of the gentamicin tested by UV-spectrometer and the absorbing rate of the calcium sulfate carrier in vitro were studied. The release patterns of two types of GSCS were compared. The trend of daily weight loss of GSCS was found being similar to that of pure calcium sulfate, which suggested that the gentamicin part has little effect on the absorbing pattern of calcium sulfate. The release rate of gentamicin is controlled by the erosion rate of calcium sulfate, so GSCS with different amount of gentamicin has the same release patterns. The DRP value of ED is higher than that of CO during the early stage, while the DRP value of ED is lower than that of CO during the late stage. The GSCS samples were implanted into the defect mold on the radii of the rabbits to investigate the potential for the use of GSCS implants as bone fillers, and the results revealed that new bone had been induced in a great part of the defect at 14 weeks after operation.

Circuit Design of Signal-collecting System for On-line Water Electrical Conductivity / 医疗卫生装备

Objective In order to eliminate the influences caused by temperature and electrode-polarization, a new circuit of measuring electrical conductivity of water is designed by AT89S52 single-chip. Methods The system adopts the bi-directional pulsed voltage as its exciting source and the DS18B20 sensor as temperature compensation circuit component. Results Three functions which include auto-control, signal-collecting and display are realized by using C51 high-level language to write the modularization program. The precision of system is improved by an auto-temperature compensation way to avoid the blindness of temperature coefficient. Conclusion The system has such advantages as high accuracy and simple operation. Through further fulfilling, it can accord with user applying.

Water Quality Analysis of the Field Seawater Desalination Reverse Osmosis Device by RO Process / 医疗卫生装备

Objective To study the operating parameters of the field seawater desalination reverse osmosis device by RO process and analyze quality of the product water.Methods In pressure of 4.90～6.37 MPa,the influence of operating pressure on salt rejection and water flux is researched to determine the best parameter.Except some conventional item test,the water quality analysis also includes BOD,COD,TOC,fluorescence spectra,ultraviolet spectra and chromatography of ions analysis.Results Operating pressure of 5.88 ～6.37 MPa,the water flux reaches 18 ～22 L/h and the ratio of desalinization exceeds 97.4%.The device has an organic contaminant elimination ratio higher than 95% and ion desalination ratio also more than 96%.The fundamental index is consistent with drinking water sanitary standard.Conclusion The field seawater desalination reverse osmosis device by RO process can effectively wipe off bacteria and contaminant of water and also can reduce salt salinity in untreated water to produce pure water for drinking.