Authenticated logarithmic-order supersingular isogeny group key exchange

International Journal of Information Security - We present the first constant-round, tree-based, group key exchange protocol based on SIDH with logarithmic-order communication and memory...     

Class III Polyphosphate Kinase 2 Enzymes Catalyze the Pyrophosphorylation of Adenosine-5′-Monophosphate

Polyphosphate kinase 2 (PPK2) transfer phosphate from inorganic polyphosphate to nucleotides. According to their activity, PPK2 enzymes are classified into three groups. Among them, class III enzymes catalyze both the phosphorylation of nucleotide mono- to diphosphates and di- to triphosphates by using polyphosphate, which is a very inexpensive substrate. Therefore, class III enzymes are very attractive for use in biotechnological applications. Despite several studies on class III enzymes, a detailed mechanism of how phosphate is transferred from the polyphosphate to the nucleotide remains to be elucidated. Herein, it is reported that PPK2 class III enzymes from two different bacterial species catalyze the phosphorylation of adenosine mono- (AMP) into triphosphate (ATP) not only through step-by-step phosphorylation, but also by pyrophosphorylation. These are the first PPK2 enzymes that have been shown to possess polyphosphate-dependent pyrophosphorylation activity.     

Examination of original plant of mulberry bark extract, a natural food additive, based on composition of the constituents

Mulberry bark extract, a natural food additive, is described as a "root bark extract from Morus bombycis" (Japanese name: Yamaguwa) in the Notice (1996) relating to existing food additives used in Japan. The results of analyses by LC/UV and LC/MS suggested that the Mulberry bark extract products that were tested were actually made from the root bark of Morus alba (Japanese name: Maguwa) or its hybrid species, because the compositions of the constituents in the products are more similar to those in the extracts of the dried root bark of M. alba and hybrid species that are cultivated in Japan than to those of M. bombycis. In addition, the constituents of the food additive products were different from those of the natural medicine Mori Cortex products ('Souhakuhi' in Japanese) made from the root bark of mulberry grown in China, and which is described as being derived from M. alba in the Japanese pharmacopoeia. These results were also corroborated by Principal Component Analysis using the peak areas of LC/MS analysis as explanatory variables. After this study, it was decided that Mulberry bark extract is one of the existing food additives that should be excluded from the list this year in Japan.     

BRCA1 and p53 Tumor Suppressor Molecules in Alzheimer’s Disease

Tumor suppressor molecules play a pivotal role in regulating DNA repair, cell proliferation, and cell death, which are also important processes in the pathogenesis of Alzheimer’s disease. Alzheimer’s disease is the most common neurodegenerative disorder, however, the precise molecular events that control the death of neuronal cells are unclear. Recently, a fundamental role for tumor suppressor molecules in regulating neurons in Alzheimer’s disease was highlighted. Generally, onset of neurodegenerative diseases including Alzheimer’s disease may be delayed with use of dietary neuro-protective agents against oxidative stresses. Studies suggest that dietary antioxidants are also beneficial for brain health in reducing disease-risk and in slowing down disease-progression. We summarize research advances in dietary regulation for the treatment of Alzheimer’s disease with a focus on its modulatory roles in BRCA1 and p53 tumor suppressor expression, in support of further therapeutic research in this field.     

Simultaneous Observation of the Lever Arm and Head Explains Myosin VI Dual Function

Myosin VI is an adenosine triphosphate (ATP)‐driven dimeric molecular motor that has dual function as a vesicle transporter and a cytoskeletal anchor. Recently, it was reported that myosin VI generates three types of steps by taking either a distant binding or adjacent binding state (noncanonical hand‐over‐hand step pathway). The adjacent binding state, in which both heads bind to an actin filament near one another, is unique to myosin VI and therefore may help explain its distinct features. However, detailed information of the adjacent binding state remains unclear. Here simultaneous observations of the head and tail domain during stepping are presented. These observations show that the lever arms tilt forward in the adjacent binding state. Furthermore, it is revealed that either head could take the subsequent step with equal probability from this state. Together with previous results, a comprehensive stepping scheme is proposed; it includes the tail domain motion to explain how myosin VI achieves its dual function.     

Brewer's yeast cell wall affects microbiota composition and decreases Bacteroides fragilis populations in an anaerobic gut intestinal model

Brewer's yeast cell wall (BYC) has been reported to have prebiotic activity that improves the microbiotal composition of the human gut. To understand the precise effect of BYC on gut microbiota and its metabolism, we used a three-stage continuous-flow reactor system that mimicked the environment of the large intestine. The reactor system was able to maintain the bacterial community stably for a week. The Bacteroides fragilis population decreased drastically after the addition of BYC into this system while the number of Lactobacillus was stably maintained. In addition, propionate and acetate levels increased drastically. This metabolic change correlated with an increase in a number of specific operational taxonomic units annotated to the genus Veillonella and Megasphaella. These results suggest that BYC affects the composition of microbiota in an in vitro model system.     

Power Generation of a p-Type Ca3Co4O9/n-Type CaMnO3 Module

Thermoelectric modules composed of eight pairs of p -type Ca_2.7Bi_0.3Co₄O₉ (Co-349) and n -type CaMn_0.98Mo_0.02O₃ (Mn-113) bulks were constructed using Ag electrodes and paste including powder of the n -type oxide. The former bulks were prepared by hot pressing. On the other hand, the latter were densified using a cold isostatic pressing technique and sintered in atmospheric pressure. Dimensions of both oxide legs were 5 mm wide and thick and 4.5 mm high. An alumina plate was used as a substrate, and there was no alumina plate on the other side of the modules. When the substrate side was heated, the module could generate up to 1.0 V and 0.17 W of open circuit voltage ( V _O) and maximum power ( P _max), respectively, at a hot-side temperature of 1273 K (furnace temperature as a heat source) and a cold-side temperature of 298 K (circulated water temperature) in air. But internal resistance R _I reached a value of 1.5 Ω, which is about six times higher than the calculated one from resistivity of both p - and n -type bulks. When the substrate side was cooled, V _O and P _max reached 0.7 V and 0.34 W of V _O and P _max, respectively, at a furnace temperature of 1273 K.