Comparative study on the inactivation of MS2 and M13 bacteriophages using energetic femtosecond lasers

Femtosecond (fs) laser irradiation techniques are emerging tools for inactivating viruses that do not involve ionizing radiation. In this work, the inactivation of two bacteriophages representing protective capsids with different geometric constraints, that is, the near‐spherical MS2 (with a diameter of 27 nm) and the filamentous M13 (with a length of 880 nm) is compared using energetic visible and near‐infrared fs laser pulses with various energies, pulse durations, and exposure times. Intriguingly, the results show that inactivation using 400 nm lasers is substantially more efficient for MS2 compared to M13. In contrast, using 800 nm lasers, M13 was slightly more efficiently inactivated. For both viruses, the genome was exposed to a harmful environment upon fs‐laser irradiation. However, in addition to the protection of the genome, the metastable capsids differ in many properties required for stepwise cell entry that may explain their dissimilar behavior after (partial) disassembly. For MS2, the dominant mechanism of fs‐laser inactivation was the aggregation of the viral capsid proteins, whereas aggregation did not affect M13 inactivation, suggesting that the dominant mechanism of M13 inactivation was related to breaking of secondary protein links.     

The world distribution of the electrophoretic variants of the red cell enzyme esterase D.

The phenotypic variation in the esterase D phenotypes among 2,405 individuals in 14 samples from populations in Europe, Africa and Asia are reported. There exists a marked difference in esterase D allele frequencies in different continental regions. Comparison of the world population data so far available show that esterase D is another useful genetic parameter for the study of population diversity.     

Screening for natural inhibitors of human topoisomerases from medicinal plants with bio-affinity ultrafiltration and LC–MS

Phytochemistry Reviews - The continuing rise in cancer morbidity and mortality all over the world makes cancer the No. 2 cause of death in humans, posing a major public health challenge. Currently,...