Low energy multiple blue light-emitting diode light Irradiation promotes melanin synthesis and induces DNA damage in B16F10 melanoma cells.

Visible light is present everywhere in our lives. Widespread use of computers and smartphones has increased the daily time spent in front of screens. What effect does this visible light have on us? Recent studies have shown that short-wavelength blue light (400-450nm) irradiation, similar to UV, inhibits the cell proliferation and differentiation, induces the intracellular oxidative stress, promotes the cell apoptosis and causes some other negative effects. However, it's unusual that directly face to such short-wavelength and high-energy blue light in daily life. Therefore, the effects of blue light with longer wavelength (470nm), lower energy (1, 2 J/cm2) and multiple times (simulated daily use) exposure on cells have been studied in this experiment. In our results, low energy density multiple blue light inhibited cell proliferation and metastatic capability with a weak phototoxicity. Blue light also promoted intracellular reactive oxygen species and caused DNA damage. Furthermore, the melanin synthesis was also promoted by low energy density multiple blue light exposure. Together, these results indicate that longer wavelength and low energy density blue light multiple exposure is still harmful to our cells. Furthermore, prolonged exposure to screens likely induces dull skin through induction of melanin synthesis. These results further mentioned us should paid more attention to controlling the daily use of digital device.

Tetrad analysis of sake yeast and identification of an RFLP marker for the absence of phenolic off-flavour production.

Mating is a promising breeding method for industrial yeast. Although sake yeast has a low spore-formation ability, segregants exhibiting a mating type have been isolated from sake yeast K7. Here, we constructed zygotes from a cross between those segregants and a laboratory yeast strain. Because most sake and brewing yeast strains are prototrophs, we developed a PCR-based method to confirm that mating had taken place based on genome sequencing data and differences in nucleotide sequences between the two parental strains. The mated strain, termed S. cerevisiae MITOY123, showed restored spore-formation ability, unlike most sake and brewing yeast strains. By using the mated yeast strain MITOY123, it was possible to carry out tetrad analysis for the trait of the absence of off-flavour due to phenolic products such as 4-vinylguiacol (4-VG) in sake yeast K7. This tetrad analysis indicated that a single genetic region around the gene PAD1 is responsible for the absence of phenolic off-flavour in sake yeast K7. In order to aid the breeding of sake and brewing yeast strains by mating, we also identified a restriction fragment length polymorphism (RFLP) marker for the absence of phenolic off-flavour production in strains derived from sake yeast K7. Collectively, our data show that it is possible to breed new sake and brewing yeast strains by mating and to test for the absence of phenolic off-flavour production in resultant strains easily by RFLP analysis.

Analysis of dynamic sitting balance on the independence of gait in hemiparetic patients.

The purpose of this study was to investigate the relationship between dynamic sitting balance and walking ability in stroke patients. Patients were evaluated using functional independence measure (FIM), and those with a locomotion score of 5 or below were categorized into the dependent walking and below group (dependent group) and those with a score of 6 or above were categorized into the independent walking group (independent group). They were asked to take a sitting position at the center of an unstable platform (seesaw). The experimenter passively tilted the unstable platform to the paretic side or non-paretic side by 10 degrees in the frontal plane. The unstable platform was released suddenly, with the experimenter supporting the platform with both hands, and the subjects were asked to control their posture so that their body axis came to the vertical position and the platform came to the horizontal position in the frontal plane. As a result, the body axis of left hemiplegic patients significantly tilted to the non-paretic side. On the other hand, in the dependent group in the right as well as left hemiplegic patients, the patients heads were tilted to the side from which tilting was started, though not significantly in both conditions. This study demonstrated that patients with poor walking function have a deviated verticality of the head and the body axis. We surmise that patients whose body axis tilts towards the non-paretic side during a dynamic balance maintenance task like this test would have lower walking independence.

Catalytic and highly enantioselective reactions of alpha-sulfonyl carbanions with chiral bis(oxazoline)s.

The enantioselective reactions of lithiated benzyl trifluoromethyl sulfones with a substoichiometric amount of a bis(oxazoline) and various aldehydes is disclosed. The products were formed with excellent diastereo- and enantioselectivities. Fluorination of the sulfone with N-fluorobenzenesulfonimide and a stoichiometric amount of a bis(oxazoline) gave products with extremely high enantioselectivities (up to 99% ee; ee=enantiomeric excess). The enantioselective reaction was confirmed to proceed through a dynamic thermodynamic resolution pathway.