The preparation of series of the controllable degradation coral-hydroxyapatite (SCHA-200R) and the on its application as the scaffold in bone tissue-engineering / 中华整形外科杂志

<p><b>OBJECTIVE</b>Fabricate series of the controllable degradation coral-hydroxyapatite.</p><p><b>METHODS</b>The natural coral undergo a chemical reaction with (NH4)2 HPO4 at high temperature and pressure for different time-lengths. After getting the products, the components and the special structures were analyzed. Observe the biologic degradation of the reaction products and analyze the metal elements and their contents. Haemolysis tests, cytotoxity tests and bone compatibility tests were performed to assess the biocompatibility of the products.</p><p><b>RESULTS</b>When hydrothermal reactions happened under different conditions, the different gradients of CaCO3/hydroxyapatite materials were produced. These types of materials kept the characteristic of interconnected micro-porous network structures. A thin layer of compact material can be seen on the surface of its trabecula ultra-micro structure. The SCHA-200R has a good biocompatibility.</p><p><b>CONCLUSIONS</b>Gradient HA (SCHA-200R) materials can be formed by adjusting the same temperature, same pressure and different time-length of the reaction. This kind of gradient material keeps the quality of micro-porous network structures. The SCHA-200R is a potential candidate scaffold for bone tissue engineering.</p>

Development and Application of RNAi Interference Library in Functional Genomics / 中国生物工程杂志

RNA interference ( RNAi) is a process in which double-stranded RNA ( dsRNA) induces specific postranscriptional silencing of homologous transcripts. Systematic silencing of genes on a genome-wide scale using RNAi library targeting many thousands of genes provides a powerful research tool in functional genomics. RNAi libraries, which may be derived from plasmids cloning, virus packaging, PCR amplification, chemically synthesis or enzymatic digestion, have been successfully used to identify gene function, dissect signaling pathway and discover drug targets, etc. Promising progresses have been made in this field. The development, application and problems of RNAi library methodology and future prospects were reviewed.

Study on the RNA of severe acute respiratory syndrome (SARS) associated coronavirus in the blood and excretion of convalescent patients with SARS / 中华流行病学杂志

<p><b>OBJECTIVE</b>To examine the RNA of severe acute respiratory syndrome-associated coronavirus (SARS-CoV) in the blood and excretion of convalescent patient with SARS for prevention and treatment of the disease.</p><p><b>METHODS</b>A total of 276 samples, including plasma, urine, feces and sputum, obtained from 23 convalescent patients with SARS were studied at 3 time-points at least 21 days after the onset of symptoms. RNA was extracted and nested reverse transcription-polymerase chain reaction (RT-PCR) was carried out using SARS-CoV specific primers.</p><p><b>RESULTS</b>Among the 276 samples, SARS-CoV RNA was detected in 6 cases (38.8%) by nested RT-PCR. The positive rates of SARS-CoV RNA was 5.8% in feces and 2.9% in sputum samples but SARS-CoV RNA was not detectable in plasma and urine of all the cases.</p><p><b>CONCLUSION</b>The existence of SARS-CoV RNA in the excretion of some convalescent patients with SARS showed that the excretion from these patients should be carefully treated whilthe re-transmission of SARS by which, should be further studied.</p>