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By imposing an economic ban on China in retaliation for the alleged sale of missile parts to Pakistan, the United States has done the right thing, but has gone only half-way towards the goal of limiting the spread of weapons.
The simple aggregation of pluripotent ES ßcells with morulae-stage embryos can result in viable chimaeras at a similar frequency to that of blastocyst injection. The savings in time and equipment inherent in the aggregation techniques, however, make this approach well worth considering.
Cell culture systems for the growth of endothelial cells and keratinocytes, a reagent for the removal of free label from antibody-label conjugate preparations and a radiochromatography flow monitor are featured this week.