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建筑工程施工安全技术 建筑物装设避雷针、避雷线、避雷网、避雷带都是防护______的主要措施。
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Stem Cell Therapy May Help Repair the HeartAccording to scientists in the USA, stem cell therapy may one day be able to repair the hearts of people with heart failure. Researchers at Pittsburgh University School of Medicine examined 20 patients who had severe heart failure and were going to have surgery.They injected stem cells into the parts of their hearts that were damaged. They then compared their hearts with those of people who had undergone surgery without having the stem cells injected into them (they had also suffered from severe heart failure). The patients who had the stem cells injected had hearts that were able to pump (用泵抽水) more blood than the others.According to Professor Robert Kormos, one of the researchers, these results could revolutionize heart treatment. Although previous studies had indicated that there might be a benefit, this is the first study that has actually proved that stem cell therapy can help the failing heart work better.All the patients in this study had hearts that could not pump blood properly. The scientists measured their ejection fraction (射血分数). This is a measure of heart performance; you measure how much blood is being pumped out by the left ventricle (心室).Healthy people"s ejection fraction is about 55%. These patients had ejection fraction of under 35%. They all had by-pass surgery (搭桥手术) performed on them. Some of the patients had stem cells taken from their hip bones and injected into 25-30 sites in the damaged heart muscle. Six months later their ejection fraction rate was 46.1% while those who just had surgery but no stem cell injections averaged 37.2%.No side effects were reported.Heart failure is a common problem all over the world. In the UK alone about 650,000 people suffer from heart failure every year. As the number of people suffering from heart failure increases in the world in general these findings are particularly significant.Current treatments relieve the symptoms. This new stem cell therapy actually repairs the damaged muscle in the heart and has the potential of curing the disease. The ejection fraction rate of the patients with stem cell injections decreased.
矿山安全技术 火区启封时，若火区范围大，火源是否完全熄灭难以确认，在此情况下，应采用______启封火区。
建筑工程施工安全技术 人工开挖土方，两人横向间距不得小于2m，纵向间距不得小于______m。
建筑工程施工安全技术 井架与施工用电梯和脚手架等与建筑物通道的两侧边必须设______，地面通道上部应装设______，双笼井架通道中间应设______。
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