National Institute of Advanced Industrial Science and Technology

About: National Institute of Advanced Industrial Science and Technology is a government organization based out in Tsukuba, Ibaraki, Japan. It is known for research contribution in the topics: Catalysis & Thin film. The organization has 22114 authors who have published 65856 publications receiving 1669827 citations. The organization is also known as: Sangyō Gijutsu Sōgō Kenkyū-sho.

Inhibitory effects of sudanese medicinal plant extracts on hepatitis C virus (HCV) protease.

Abstract: One hundred fifty-two methanol and water extracts of different parts of 71 plants commonly used in Sudanese traditional medicine were screened for their inhibitory effects on hepatitis C virus (HCV) protease (PR) using in vitro assay methods. Thirty-four extracts showed significant inhibitory activity (>/=60% inhibition at 100 microg/mL). Of these, eight extracts, methanol extracts of Acacia nilotica, Boswellia carterii, Embelia schimperi, Quercus infectoria, Trachyspermum ammi and water extracts of Piper cubeba, Q. infectoria and Syzygium aromaticum, were the most active (>/=90% inhibition at 100 microg/mL). From the E. schimperi extract, two benzoquinones, embelin (I) and 5-O-methylembelin (II), were isolated and found as potent HCV-PR inhibitors with IC(50) values of 21 and 46 microM, respectively. Inhibitory activities of derivatives of I against HCV-PR as well as their effects on other serine proteases were also investigated.

Firefly bioluminescence quantum yield and colour change by pH-sensitive green emission

Abstract: Firefly bioluminescence1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19 is the most well-known ideal photo-emitter system in biophotonics, known in particular for its extremely high quantum yield, 88 ± 25% (refs 2,3) or higher4,5,6, and its magnificent pH-dependent emission-colour change3,7 between yellow-green and red, modelled as the chemical equilibrium between two corresponding states8,9,10,11,12,13,14 However, the need for re-examination has also been discussed4,5,6 In this letter we quantify quantum yields and colour changes using our new total-photon-flux spectrometer20,21 We determine the highest quantum yield to be 410 ± 74% (1 standard deviation (sd) estimate, coverage factor k = 1), and find that bioluminescence spectra are systematically decomposed into one pH-sensitive and two pH-insensitive gaussian components There is no intensity conversion between yellow-green and red emissions through pH equilibrium, but simple intensity variation of the pH-sensitive gaussian peak at 22 eV causes the changes in emission colours This represents a paradigm shift in the concept of colour determination from long-standing interpretation based on pH equilibrium

Functional identification and reconstitution of an odorant receptor in single olfactory neurons

Abstract: The olfactory system is remarkable in its capacity to discriminate a wide range of odorants through a series of transduction events initiated in olfactory receptor neurons. Each olfactory neuron is expected to express only a single odorant receptor gene that belongs to the G protein coupled receptor family. The ligand–receptor interaction, however, has not been clearly characterized. This study demonstrates the functional identification of olfactory receptor(s) for specific odorant(s) from single olfactory neurons by a combination of Ca2+-imaging and reverse transcription–coupled PCR analysis. First, a candidate odorant receptor was cloned from a single tissue-printed olfactory neuron that displayed odorant-induced Ca2+ increase. Next, recombinant adenovirus-mediated expression of the isolated receptor gene was established in the olfactory epithelium by using green fluorescent protein as a marker. The infected neurons elicited external Ca2+ entry when exposed to the odorant that originally was used to identify the receptor gene. Experiments performed to determine ligand specificity revealed that the odorant receptor recognized specific structural motifs within odorant molecules. The odorant receptor-mediated signal transduction appears to be reconstituted by this two-step approach: the receptor screening for given odorant(s) from single neurons and the functional expression of the receptor via recombinant adenovirus. The present approach should enable us to examine not only ligand specificity of an odorant receptor but also receptor specificity and diversity for a particular odorant of interest.