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The increasing stocking density of algal often results in lowered carbon and light levels. In this study, Pyropia haitanensis were cultured under four different conditions, i.e., 390 μL·L -1 (ambient carbon supply) + ambient sunlight, 20 μL·L -1 (decreased carbon supply) + ambient sunlight, 390 μL·L -1 + decreased sunlight (20% of ambient sunlight), 20 μL·L -1 + decreased sunlight. The activity of carbonic anhydrase (CA), photosynthetic rate and quantum efficiency of open photosynthetic system 2 (F v '/F m ') of the algae under different temperatures were measured to investigate the effects of decreased carbon supply and lowered light on photosynthetic functions of P. haitanensis. The results showed the CA activities of the algae at decreased carbon supply and lowered sunlight was increased. The maximum C i -saturated photosynthetic rates (V max ) were elevated under the low sunlight compared with that under the ambient sunlight. The V max of the algae at low carbon seawater was lower than that at ambient carbon seawater under lowered sunlight. Under ambient sunlight, the V max of the decreased carbon-grown algae was higher than that of ambient carbon-grown algae. The F v '/F m ' values of the algae grown at lowered carbon supply and decreased sunlight conditions showed no variation at low temperature (10 ℃) and high temperature (30 ℃), whereas it was decreased by about 76.4% when cultured at 390 μL·L -1 + ambient sunlight at 200 min than that at 40 min under 30 ℃. These results suggested that decreased carbon supply and lowered sunlight intensity would improve in the capacity of HCO 3 - utilization and resistance to short-term temperature change in P. haitaneisis. The effects of low carbon on photosynthetic rate of the algae were dependent on light context.

Recent outbreak of H1N1 virus worldwide has caused 16 226 deaths in over 213 countries and districts. Binding between the virus and the receptor on the host cell surface is the key initial event for the infection, which results in the fusion of viral host cell membrane. Hemagglutinin (HA) is the viral protein that mediates the receptor binding and membrane fusion. The receptor binding sites (RBSs) are located at the membrane-distal part of each subunit of the HA trimer and are formed by three secondary structure elements, 190 helix (residues 190 to 198), 130 loop (residues 135 to 138), and 220 loop (residues 221 to 228). HA1 with 327 amino acid sequences in length was collected from 1221 H1N1 viruses between 1918 and 2009, and bioinformatic studies were carried out through sequence comparison, entropy calculation for each amino acid residue, and 3D structure modeling. The results showed that the RBSs of different viruses with different hosts have different entropies, and the RBSs in HA1 with different hosts have different favorite amino acid sequences. The 3D modeling indicates the subtly conformation changes in the 190 helix region between different HA1s in H1N1. This study explores new characters of the RBS structure in different HA1s, and provides new information for the further investigation of the infection mechanism.

A novel reaction-enzymatic ammonolysis discovered in the mid of 1990s has been demonstrated to be a very promising alternative in the preparation of optically pure compounds. The effects of organic solvent, initial water activity, temperature and additives on lipase Novozym435-catalyzed enantioselective ammonolysis of racemic phenylglycine methyl ester were investigated systematically in this paper. Enzymatic reaction of ammonolysis showed higher activity and enantioselectivity than the corresponding reaction of hydrolysis and alcoholysis.