A surge of light at the birth of a supernova.

It is difficult to establish the properties of massive stars that explode as supernovae. The electromagnetic emission during the first minutes to hours after the emergence of the shock from the stellar surface conveys important information about the final evolution and structure of the exploding star. However, the unpredictable nature of supernova events hinders the detection of this brief initial phase. Here we report the serendipitous discovery of a newly born, normal type IIb supernova (SN 2016gkg), which reveals a rapid brightening at optical wavelengths of about 40 magnitudes per day. The very frequent sampling of the observations allowed us to study in detail the outermost structure of the progenitor of the supernova and the physics of the emergence of the shock. We develop hydrodynamical models of the explosion that naturally account for the complete evolution of the supernova over distinct phases regulated by different physical processes. This result suggests that it is appropriate to decouple the treatment of the shock propagation from the unknown mechanism that triggers the explosion.

A new technique of laparoscopic surgery for rectal disease.

Laparoscopic rectal surgery is a technique that has to be done in a narrow space: the pelvis. If an immoderate operation is performed with a difficult view, for example in female where the field is disturbed by uterus, it is possible to produce organ trauma or an unexpected bleeding. Taking these problems in mind, we performed laparoscopic surgery in 44 cases of rectal disease with several techniques which we have invented. In these cases either the uterus or the rectum was retracted in the narrow space, and if an anterior resection was to be done, the tape was tied tightly around the rectum below the tumor to avoid touching the tumor and leaving adequate vascular irrigation to the remnant rectum. With the use of our techniques, we did not have female intestinal injury or unexpected bleeding. In addition laparoscopic anterior resection of rectum did not cause any intestinal injury, or unexpected bleeding or anastomotic leakage; also we did not have any local tumor recurrence. It is our belief that these techniques can decrease complications that traumatize the grasping intestine with intestinal forceps and prevent implantation in the anastomosis. This technical report validate that our technique modifications for rectal laparoscopic surgery are useful when a surgeon has to work in a narrow space.

Phylogenetic analysis of the long terminal repeat of feline immunodeficiency viruses from Japan, Argentina and Australia.

The nucleotide sequences of the long terminal repeat of five Japanese, five Argentine and three Australian isolates of feline immunodeficiency virus (FIV) were determined and compared with those of isolates previously described. The results revealed that the Japanese isolates were found to cluster with nucleotide sequence similarity of 95.6%-99.4%. The Australian isolates also clustered with nucleotide sequence similarity of 97.2%-99.4%. The Argentine isolates formed two groups; the LP9 isolate is closely related to the Japanese isolates, whereas the LP1, LP3, LP20 and LP24 isolates are distant from both the Japanese and Australian isolates. From these results, FIV can be divided into three groups, namely: (I) the Californian, Australian and British isolates; (II) the Japanese isolates and one Argentine LP9 isolate; (III) the other Argentine isolates.

High-performance liquid chromatographic separation of enantiomeric alkyl glycerol ethers.

The resolution of a series of racemic 1-alkyl-3-trityl-rac-glycerols and 1-alkyl-2-benzyl-rac-glycerols into their enantiomers by high-performance liquid chromatography (HPLC) was investigated. Of the racemic glycerol derivatives studied, only three (1,2-0-isopropylidene-rac-glycerol, 1,2-0-isopropylidene-3-benzyl-rac-glycerol and 1-hexadecyl-2-benzyl-rac-glycerol) could be resolved into their enantiomers. The compounds were resolved on a silica (10 µm) column coated with cellulose tribenzoate and eluted isocratically with hexane/isopropanol as mobile phase. The effects of mobile phase composition, column temperature and flow rate on the resolution of enantiomeric pairs were investigated. Also, the effect of substituents,i.e., trityl, benzyl, hydroxyl or alkyl, on the resolution of the alkyl glycerol ethers by HPLC was evaluated.