Pd–P Hydrogenation Catalyst: Nanoparticle Nature and Surface Layer State

Lyudmila B. Belykh,Nikita I. Skripov,Tatyana P. Sterenchuk,Vitaliy A. Umanets,Fedor K. Schmidt 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2016 NANO Vol.11 No.6

The Pd–P selective catalyst for liquid-phase hydrogenation of o-chloronitrobenzene (o-CNB) was obtained by the reduction of Pd(acac)2 with hydrogen at 80℃ in the presence of white phosphorus (P/Pd=1) in N,N-dimethylformamide (DMF). It has been shown [(high-resolution transmission electron microscopy (HRTEM), energy dispersive X-ray spectroscopy (EDX), X-ray powder diffraction (XRD)] that such low-temperature synthesis of the Pd–P catalyst affords nanoparticles of palladium phosphides (Pd5P2, PdP2), the Pd5P2 phosphide being prevailing. On the nanoparticle surface, palladium is present as a phosphide (BE (Pd3d5/2)=336.2 eV; BE (P2p3/2)=130 eV) and as palladium clusters of 1 nm in diameter. The formation of the Pd–P catalyst proceeds through a number of stages: a redox process between Pd(acac)2 and white phosphorus affording mainly PdP2 nanoparticles, H3PO3 and acacH; next follows the reduction of unreacted Pd(acac)2 with hydrogen at 80℃ and the reaction of Pd(0) atoms with each other and with PdP2. It is assumed that formation of small palladium clusters on the surface of the Pd5P2 nanoparticles ensures the high selectivity of the Pd–P catalyst in the o-CNB hydrogenation.

Investigation of cellular targeting of carotenoid pathway enzymes in Pichia pastoris

Lee, P.C.,Yoon, Y.g.,Schmidt-Dannert, C. Elsevier Science Publishers 2009 Journal of biotechnology Vol.140 No.3

Cellular targeting of lycopene biosynthetic enzymes was investigated in Pichia pastoris X-33. Three lycopene pathway enzymes, CrtE, CrtB, and CrtI, were fused to fluorescent EGFPs with or without a peroxisomal targeting sequence (PTS1) and then expressed in P. pastoris. When P. pastoris was grown in YPD, the PTS1 fusion enzymes were found to be localized in peroxisomes, whereas the enzymes not fused with PTS1 were equally distributed throughout the entire cell. A similar targeting pattern was also observed in P. pastoris strains that were grown in peroxisome-proliferating medium, YPOT. Analysis of the fluorescent images of isolated peroxisomes showed that the PTS1 fused enzymes were dominantly present in peroxisomes whereas small amount of the enzymes not fused with PTS1 were non-specifically sent to peroxisomes. These results indicate that PTS1 specifically target lycopene pathway enzymes into peroxisomes and this targeting pathway was strong enough to overcome their inherent targeting program. In conclusion, we first showed that carotenogenic enzymes can be targeted into the specific cellular location of recombinant hosts and this targeting strategy can serve as the basis for the subsequent development of sophisticated pathway engineering in microorganisms.

Intron 4 VNTR (4a/b) Polymorphism of the Endothelial Nitric Oxide Synthase Gene Is Associated with Breast Cancer in Mexican Women

Ramírez-Patiño Ramiro,Figuera Luis Eduardo,Puebla-Pérez Ana María,Delgado-Saucedo Jorge Ivan,Legazpi-Macias María Magdalena,Mariaud-Schmidt Rocio Patricia,Ramos-Silva Adriana,Gutiérrez-Hurtado Itzae A 대한의학회 2013 Journal of Korean medical science Vol.28 No.11

The endothelial nitric oxide synthase (eNOS) gene plays an important role in several biological functions. Polymorphisms of the eNOS gene have been associated with cancer. It has been suggested that the VNTR 4 a/b polymorphism may affect the expression of eNOS and contributes to tumor promotion in the mammary gland. We examined the role of the eNOS4 a/b polymorphism by comparing the genotypes of 281 healthy Mexican women with the genotypes of 429 Mexican women with breast cancer (BC). The observed genotype frequencies for control and BC patients were 0.6% and 0.7% for a/a (polymorphic); 87% and 77% for a/a (wild type); and 12% and 22% for a/b respectively. We found that the odds ratio (OR) was 1.9, with a 95% confidence interval (95%CI) of 1.29-2.95, P=0.001 for genotypes a/a-a/b, b/c. The association was also evident when comparing the distribution of the a/a-a/b genotypes in patients with high levels of glutamate-oxaloacetate transaminase (SGOT) (OR, 1.93; 95% CI, 1.14-3.28; P=0.015); undergoing menopause with high levels of SGOT (OR, 2.0; 95% CI, 1.1-3.84); and with high levels of glutamic-pyruvic transaminase (SGPT) (OR, 3.5; 95% CI, 1.56-8.22). The genotypes a/a-a/b are associated with BC susceptibility in the analyzed samples from the Mexican population.

Sub-100-fs Cr:YAG laser mode-locked by monolayer graphene saturable absorber.

Davide Di Dio Cafiso, Samuele,Ugolotti, Elena,Schmidt, Andreas,Petrov, Valentin,Griebner, Uwe,Agnesi, Antonio,Cho, Won Bae,Jung, Bo Hee,Rotermund, Fabian,Bae, Sukang,Hong, Byung Hee,Reali, Giancarlo,P Optical Society of America 2013 Optics letters Vol.38 No.10

<P>We report on mode-locking of a Cr:YAG laser at 1516 nm using a monolayer graphene-based saturable absorber of transmission type generating 91 fs pulses with a Fourier product of 0.38 at an average output power exceeding 100 mW. Stable single-pulse mode-locked operation without any sign of Q-switching instabilities or multiple pulses is achieved.</P>

Rotation periods and astrometric motions of the Luhman 16AB brown dwarfs by high-resolution lucky-imaging monitoring

Mancini, L.,Giacobbe, P.,Littlefair, S. P.,Southworth, J.,Bozza, V.,Damasso, M.,Dominik, M.,Hundertmark, M.,Jørgensen, U. G.,Juncher, D.,Popovas, A.,Rabus, M.,Rahvar, S.,Schmidt, R. W.,Skottfelt, J.,S EDP Sciences 2015 Astronomy and astrophysics Vol.584 No.-

<P>Context. Photometric monitoring of the variability of brown dwarfs can provide useful information about the structure of clouds in their cold atmospheres.The brown-dwarf binary system Luhman16AB is an interesting target for such a study, because its components stand at the L/T transition and show high levels of variability. Luhman16AB is also the third closest system to the solar system, which allows precise astrometric investigations with ground-based facilities. Aims. The aim of the work is to estimate the rotation period and study the astrometric motion of both components. Methods. We have monitored Luhman16AB over a period of two years with the lucky-imaging camera mounted on the Danish 1.54m telescope at La Silla, through a special i + z long-pass filter, which allowed us to clearly resolve the two brown dwarfs into single objects. An intense monitoring of the target was also performed over 16 nights, in which we observed a peak-to-peak variability of 0.20±0.02mag and 0.34±0.02mag for Luhman16A and 16B, respectively. Results. We used the 16-night time-series data to estimate the rotation period of the two components. We found that Luhman16B rotates with a period of 5.1 ±0.1h, in very good agreement with previous measurements. For Luhman16A, we report that it rotates more slowly than its companion, and even though we were not able to get a robust determination, our data indicate a rotation period of roughly 8h. This implies that the rotation axes of the two components are well aligned and suggests a scenario in which the two objects underwent the same accretion process. The 2-year complete data set was used to study the astrometric motion of Luhman16AB. We predict a motion of the system that is not consistent with a previous estimate based on two months of monitoring, but cannot confirm or refute the presence of additional planetary-mass bodies in the system.</P>

UNNOTICED MAGNETIC FIELD OSCILLATIONS IN THE VERY QUIET SUN REVEALED BY SUNRISE/IMaX

Martí,nez Gonzá,lez, M. J.,Asensio Ramos, A.,Manso Sainz, R.,Khomenko, E.,Martí,nez Pillet, V.,Solanki, S. K.,Ló,pez Ariste, A.,Schmidt, W.,Barthol, P.,Gandorfer, A. IOP Publishing 2011 ASTROPHYSICAL JOURNAL LETTERS - Vol.730 No.2

<P>We present observational evidence for oscillations of magnetic flux density in the quiet areas of the Sun. The majority of magnetic fields on the solar surface have strengths of the order of or lower than the equipartition field (300-500 G). This results in a myriad of magnetic fields whose evolution is largely determined by the turbulent plasma motions. When granules evolve they squash the magnetic field lines together or pull them apart. Here, we report on the periodic deformation of the shapes of features in circular polarization observed at high resolution with SUNRISE. In particular, we note that the area of patches with a constant magnetic flux oscillates with time, which implies that the apparent magnetic field intensity oscillates in antiphase. The periods associated with this oscillatory pattern are compatible with the granular lifetime and change abruptly, which suggests that these oscillations might not correspond to characteristic oscillatory modes of magnetic structures, but to the forcing by granular motions. In one particular case, we find three patches around the same granule oscillating in phase, which means that the spatial coherence of these oscillations can reach 1600 km. Interestingly, the same kind of oscillatory phenomenon is also found in the upper photosphere.</P>

COMPARISON BETWEEN Mg II<i>k</i>AND Ca II H IMAGES RECORDED BY SUNRISE/SuFI

Danilovic, S.,Hirzberger, J.,Riethmü,ller, T. L.,Solanki, S. K.,Barthol, P.,Berkefeld, T.,Gandorfer, A.,Gizon, L.,Knö,lker, M.,Schmidt, W.,Rodrí,guez, J. Blanco,Iniesta, J. C. Del Toro IOP Publishing 2014 The Astrophysical journal Vol.784 No.1

<P>We present a comparison of high-resolution images of the solar surface taken in the MgII k and Ca II H channels of the Filter Imager on the balloon-borne solar observatory SUNRISE. The Mg and Ca lines are sampled with 0.48 nm and 0.11 nm wide filters, respectively. The two channels show remarkable qualitative and quantitative similarities in the quiet Sun, in an active region plage and during a small flare. However, the Mg filtergrams display 1.4-1.7 times higher intensity contrast and appear more smeared and smoothed in the quiet Sun. In addition, the fibrils in a plage are wider. Although the exposure time is 100 times longer for Mg images, the evidence suggests that these differences cannot be explained only with instrumental effects or the evolution of the solar scene. The differences at least partially arise because of different line-formation heights, the stronger response of Mg k emission peaks to the higher temperatures, and the larger height range sampled by the broad Mg filter used here. This is evidently manifested during the flare when a surge in Mg evolves differently than in Ca.</P>

THE FRONTIER BETWEEN SMALL-SCALE BIPOLES AND EPHEMERAL REGIONS IN THE SOLAR PHOTOSPHERE: EMERGENCE AND DECAY OF AN INTERMEDIATE-SCALE BIPOLE OBSERVED WITH SUNRISE/IMaX

Guglielmino, S. L.,Martí,nez Pillet, V.,Bonet, J. A.,del Toro Iniesta, J. Carlos,Bellot Rubio, L. R.,Solanki, S. K.,Schmidt, W.,Gandorfer, A.,Barthol, P.,Knö,lker, M. IOP Publishing 2012 The Astrophysical journal Vol.745 No.2

<P>We report on the photospheric evolution of an intermediate-scale (approximate to 4 Mm footpoint separation) magnetic bipole, from emergence to decay, observed in the quiet Sun at high spatial (0 ''.3) and temporal (33 s) resolution. The observations were acquired by the Imaging Magnetograph Experiment imaging magnetograph during the first science flight of the Sunrise balloon-borne solar observatory. The bipole flux content is 6x10(17) Mx, representing a structure bridging the gap between granular scale bipoles and the smaller ephemeral regions. Footpoints separate at a speed of 3.5 km s(-1) and reach a maximum distance of 4.5 Mm before the field dissolves. The evolution of the bipole is revealed to be very dynamic: we found a proper motion of the bipole axis and detected a change of the azimuth angle of 90 degrees in 300 s, which may indicate the presence of some writhe in the emerging structure. The overall morphology and behavior are in agreement with previous analyses of bipolar structures emerging at the granular scale, but we also found several similarities with emerging flux structures at larger scales. The flux growth rate is 2.6 x 10(15) Mx s(-1), while the mean decay rate is one order of magnitude smaller. We describe in some detail the decay phase of the bipole footpoints that includes break up into smaller structures, and interaction with preexisting fields leading to cancellation, but it appears to be dominated by an as-yet unidentified diffusive process that removes most of the flux with an exponential flux decay curve. The diffusion constant (8 x 10(2) km(2) s(-1)) associated with this decay is similar to the values used to describe the large-scale diffusion in flux transport models.</P>

Oxazole - Acetonitrile - Water 삼성분계의 정압 기액평형

Schmidt, A P,박소진 한국화학공학회 1991 NICE Vol.9 No.3

The role of mutations in COL6A3 in isolated dystonia

Lohmann, K.,Schlicht, F.,Svetel, M.,Hinrichs, F.,Zittel, S.,Graf, J.,Lohnau, T.,Schmidt, A.,Mir, P.,Krause, P. Springer Science + Business Media 2016 Journal of neurology: Zeitschrift für Neurolo Vol.263 No.4

<P>Specific mutations in COL6A3 have recently been reported as the cause of isolated recessive dystonia, which is a rare movement disorder. In all patients, at least one mutation was located in Exons 41 and 42. In an attempt to replicate these findings, we assessed by direct sequencing the frequency of rare variants in Exons 41 and 42 of COL6A3 in 955 patients with isolated or combined dystonia or with another movement disorder with dystonic features. We identified nine heterozygous carriers of rare variants including five different missense mutations and an extremely rare synonymous variant. In these nine patients, we sequenced the remaining 41 coding exons of COL6A3 to test for a second mutation in the compound heterozygous state. In only one of them, a second rare variant was identified (Thr732Met + Pro3082Arg). Of note, this patient had been diagnosed with ParkinsonA ' s disease (with dystonic posturing) due to homozygous PINK1 mutations. The COL6A3 mutations clearly did not segregate with the disease in the four affected siblings of this family. Further, there was no indication for a disease-modifying effect of the COL6A3 mutations since disease severity or age at onset did not correlate with the number of COL6A3 mutated alleles in this family. In conjunction with the relatively high frequency of homozygous carriers of reported mutations in publically available databases, our data call a causal role for variants in COL6A3 in isolated dystonia into question.</P>