A novel ATP regeneration system using polyphosphate-AMP phosphotransferase and polyphosphate kinase

Polyphosphate-AMP phosphotransferase (PAP) and polyphosphate kinase (PPK) were used for designing a novel ATP regeneration system, named the PAP-PPK ATP regeneration system. PAP is an enzyme that catalyzes the phospho-conversion of AMP to ADP, and PPK catalyzes ATP formation from ADP. Both enzymes use inorganic polyphosphate [poly(P)] as a phosphate donor. In the PAP-PPK ATP regeneration system, ATP was continuously synthesized from AMP by the coupling reaction of PAP and PPK using poly(P). Poly(P) is a cheap material compared to acetyl phosphate, phosphoenol pyruvate and creatine phosphate, which are phosphate donors used for conventional ATP regeneration systems. To achieve efficient synthesis of ATP from AMP, an excessive amount of poly(P) should be added to the reaction solution because both PAP and PPK consume poly(P) as a phosphate donor. Using this ATP generation reaction, we constructed the PAP-PPK ATP regeneration system with acetyl-CoA synthase and succeeded in synthesizing acetyl-CoA from CoA, acetate and AMP. Since too much poly(P) may chelate MG2+ and inhibit enzyme activity, the Mg2+ concentration was optimized to 24 mM in the presence of 30 mM poly(P) in the reaction. In this reaction, ATP was regenerated 39.8 times from AMP, and 99.5% of CoA was converted to acetyl-CoA. In addition, since the PAP-PPK ATP regeneration system can regenerate GTP from GMP, it could also be used as a GTP regeneration system.     

Geometrical indications of adsorbed hydrogen atoms on graphite producing star and ellipsoidal like features in scanning tunneling microscopy images: Ab initio study

Recent scanning tunneling microscopy (STM) experiments display images with star and ellipsoidal like features resulting from unique geometrical arrangements of a few adsorbed hydrogen atoms on graphite. Based on first-principles STM simulations, we have found that the model with three hydrogen atoms, in which the hydrogen atoms are symmetrically placed on the graphene sheet in an equilateral triangle, encompassing a complete hexagon ring of carbon atoms, reproduces the experimentally observed starlike STM patterns. Additionally, we confirm that an ortho-hydrogen pair is the configuration corresponding to the ellipsoidal images. These calculations reveal that when the hydrogen pairs are in the same orientation, they are energetically more stable.     

Design and Simulation of a Nanophotonic Traceable Memory Using Localized Energy Dissipation and Hierarchy of Optical Near-Field Interactions

Optical near-field interactions allow energy localization at scales smaller than the diffraction limit of light. They also show intrinsic hierarchical responses, meaning that optical near-fields exhibit different physical behavior at different scales. In this paper, by combining the localized energy dissipation and hierarchy properties, we present an architecture for a novel traceable optical memory that records memory access events to each bit, which is useful in applications such as high-security information transfer. The basic principles are demonstrated by numerical simulations using a metal nanostructure.     

First principles study on desorption of chemisorbed hydrogen atoms from single-walled carbon nanotubes under external electric field

Based on first principles calculations, we suggest a new way to release chemisorbed hydrogen atoms from the single-walled carbon nanotubes. The transverse external electric field serves as the key source for this mechanism. As the electric field strength increases, there is a notable increase in the C–H bond lengths at the sharp highly curved sites of the carbon nanotube. The compression of the tube along the direction of electric field results in the release of hydrogen atoms from the sharp sites. The synergetic action of electric field and compression turns out the desorption process easier at favorable field strengths. This present investigation provides a new alternative way to release hydrogen atoms from the hydrogenated carbon nanotubes under the influence of external electric field that requires comparatively lower temperature suitable for hydrogen based fuel cells used in mobile applications.     

Structures of Mn clusters

The geometries of several Mn clusters in the size range Mn₁₃-Mn{on23} are studied via the generalized gradient approximation to density functional theory. For the 13-and 19-atom clusters, the icosahedral structures are found to be most stable, while for the 15-atom cluster, the bcc structure is more favoured. The clusters show ferrimagnetic spin configurations.     

Two siblings with adult-onset sialidosis type I (cherry-red spot-myoclonus syndrome)

A questionnaire was sent to 967 schoolchildren, in two age groups, in northern Finland in order to investigate the prevalence of chronic knee pain. A response rate of 88.5% was achieved. Adolescents (aged 14-15 years) had significantly more knee pain (p < 0.0001) than children (aged 9-10 years). The total prevalence of chronic knee pain at the time of the evaluation was 18.5% among adolescents and 3.9% among children. There was no significant difference in the prevalence of chronic knee pain between boys and girls in these age groups. Overweight was not a predisposing factor in chronic knee pain.     

In vitro and in vivo antibacterial activities of AM-1155 in the fields of obstetrics and gynecology

OBJECTIVES: Until relatively recently southern Europe was regarded as having a medium to low multiple sclerosis prevalence, of about 20 or less per 100,000. However, recent studies in Sardinia, Sicily, continental Italy, Cyprus and Spain have yielded higher MS prevalence rates, between 32 and 102.6 per 100,000. We present the results of a prevalence study of MS in the municipality of M6stoles, central Spain. MATERIAL AND METHODS: To ascertain the prevalence of multiple sclerosis in M6stoles (195,979 inhabitants), an intensive study was undertaken using several sources of information. We used the Poser criteria in diagnosis. RESULTS: There were 85 patients (53 women and 32 men) classified as definite or probable, prevalence 43.4/100,000 (95% CI, 34.7 to 53.7). The incidence rate was 3.8/100,000/year (95% CI, 2.7 to 5.3) in the last 5 years. Mean age on prevalence day was 38.8+/-10.9 years. Mean age at onset was 31.7+/-9.3 years. Mean interval between initial symptoms and diagnosis was 1.7 years. Mean duration of disease was 7.6+/-6.1 years. Overall, 70.6% had a relapsing-remitting course, 18.8% had a primary progressive and 10.5% had a secondary progressive. Mean EDSS score was 2.7+/-1.9. CONCLUSION: The M6stoles study confirms the conclusions of previous smaller population studies that Spain is a moderately high or medium MS risk zone.     

Small-angle X-ray scattering of long-period structures forming bundles

Small-angle X-ray scattering (SAXS) patterns have been calculated based on a structure model, which consisted of the bundles of long-period structures. The proposed model has produced various scattering patterns of polymers, such as the equatorial, layer line, four-spot, droplet-shaped and triangular scattering. The 0.5th order scattering has arisen when the disorder in or between the long-period structures was large even though the structure did not have the periodicity directly related to the scattering maximum. A slight decrease in the disorder due to slip between the long-period structures has accounted for the sudden change of the SAXS pattern of a poly(ethylene terephthalate) fiber from the four-spot to the layer line scattering which was caused by a slight tensile deformation.