Rediscovery of the <i>Ochromonas</i> type species <i>Ochromonas triangulata</i> (Chrysophyceae) from its type locality (Lake Veysove, Donetsk region, Ukraine)

Andersen, Robert A.,Graf, Louis,Malakhov, Yuriy,Yoon, Hwan Su Informa UK (TaylorFrancis) 2017 Phycologia Vol.56 No.6

<P>Ochromonas triangulata, the type species for a genus with over 125 taxa, was collected for only the second time, again from the type locality. Cell morphology, cell division, palmelloid stage and cyst structure generally agreed with the original description. Molecular phylogenetic analysis based on the 18S rRNA gene revealed 13 clades of Ochromonas-like flagellates as well as the clade represented by our O. triangulata strain and the nearly identical strain RCC-21/AC025. We also conducted a concatenated analysis using the 18S rRNA and the rbcL genes, and we recovered the same 14 clades. One clade, containing strains CCAP 933/27 and CCMP1861, previously named Ochromonas tuberculata, was re-identified as Chrysastrella paradoxa and Chrysastrella breviappendiculata, respectively. One clade included the Poterioochromonas strains but we were unable to convincingly connect species names to the strains because authentic strains were unknown or not examined. Organisms in the clade that included the well-known Ochromonas danica were assigned to Chlorochromonas. The generic name Melkoniania gen. nov. was proposed for one distinct clade of marine flagellates. These changes addressed some of the issues associated with the polyphyletic Ochromonas sensu lato but many problems remained.</P>

One-Dimensional Exchange NMR Studies on Semicrystalline Polyethylenes

신은지,윤도영,Robert Graf,Hans Wolfgang Spiess 한국고분자학회 2004 한국고분자학회 학술대회 연구논문 초록집 Vol.29 No.2

Mantle cell lymphoma relapsed after autologous stem cell transplantation: a single-center experience

Aaron Wu,Solomon A. Graf,Nicholas Burwick,Jonathan E. Grim,Zhao Ming Dong,Robert E. Richard,Thomas R. Chauncey 대한혈액학회 2020 Blood Research Vol.55 No.1

BackgroundAutologous stem cell transplantation (autoSCT) can extend remission of mantle cell lym-phoma (MCL), but the management of subsequent relapse is challenging.MethodsWe examined consecutive patients with MCL who underwent autoSCT at Veterans Affairs Puget Sound Health Care System between 2009 and 2017 (N=37).ResultsTen patients experienced disease progression after autoSCT and were included in this analysis. Median progression free survival after autoSCT was 1.8 years (range, 0.3‒7.1) and median overall survival after progression was only 0.7 years (range, 0.1 to not reached). The 3 patients who survived more than 1 year after progression were treated with ibrutinib.ConclusionOur findings suggest that ibrutinib can achieve relatively prolonged control of MCL pro-gressing after autoSCT.

High-temperature in situ crystallographic observation of reversible gas sorption in impermeable organic cages

Baek, Seung Bin,Moon, Dohyun,Graf, Robert,Cho, Woo Jong,Park, Sung Woo,Yoon, Tae-Ung,Cho, Seung Joo,Hwang, In-Chul,Bae, Youn-Sang,Spiess, Hans W.,Lee, Hee Cheon,Kim, Kwang S. National Academy of Sciences 2015 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF Vol.112 No.46

<P><B>Significance</B></P><P>Crystallographic observation of adsorbed gas molecules at high temperatures is a highly challenging task due to their rapid motion. We provide evidence of restrained motions in a self-assembled organic crystal with small isolated cages, inside which the confined CO<SUB>2</SUB> molecules can be identified with in situ X-ray diffraction technique at the high temperature. Although the crystal is nonporous, the CO<SUB>2</SUB> molecules can permeate into the crystal because of thermally activated transient pathways between the cages. We show that the flexible nature of the transient pathways leads to the temperature-driven reversible CO<SUB>2</SUB> sorption, understanding of which can contribute to the design of a system with controlled capture/release of gas molecules.</P><P>Crystallographic observation of adsorbed gas molecules is a highly difficult task due to their rapid motion. Here, we report the in situ single-crystal and synchrotron powder X-ray observations of reversible CO<SUB>2</SUB> sorption processes in an apparently nonporous organic crystal under varying pressures at high temperatures. The host material is formed by hydrogen bond network between 1,3,5-tris-(4-carboxyphenyl)benzene (H<SUB>3</SUB>BTB) and <I>N,N</I>-dimethylformamide (DMF) and by π–π stacking between the H<SUB>3</SUB>BTB moieties. The material can be viewed as a well-ordered array of cages, which are tight packed with each other so that the cages are inaccessible from outside. Thus, the host is practically nonporous. Despite the absence of permanent pathways connecting the empty cages, they are permeable to CO<SUB>2</SUB> at high temperatures due to thermally activated molecular gating, and the weakly confined CO<SUB>2</SUB> molecules in the cages allow direct detection by in situ single-crystal X-ray diffraction at 323 K. Variable-temperature in situ synchrotron powder X-ray diffraction studies also show that the CO<SUB>2</SUB> sorption is reversible and driven by temperature increase. Solid-state magic angle spinning NMR defines the interactions of CO<SUB>2</SUB> with the organic framework and dynamic motion of CO<SUB>2</SUB> in cages. The reversible sorption is attributed to the dynamic motion of the DMF molecules combined with the axial motions/angular fluctuations of CO<SUB>2</SUB> (a series of transient opening/closing of compartments enabling CO<SUB>2</SUB> molecule passage), as revealed from NMR and simulations. This temperature-driven transient molecular gating can store gaseous molecules in ordered arrays toward unique collective properties and release them for ready use.</P>

Protein can be taken up by damaged wheat roots and transported to the stem

Jay Rasmussen,Brandon H. Gilroyed,Tim Reuter,Ana Badea,François Eudes,Robert Graf,André Laroche,Nat NV Kav,Tim A. McAllister 한국식물학회 2015 Journal of Plant Biology Vol.58 No.1

Proteins of animal origin can represent a portion of the overall nitrogen (N) pool in the soil environment and there is a possibility that plants may utilize animal proteins as a N source. Using wheat (Triticum aestivum L.) we investigated if the model protein, ovalbumin was taken up into the roots and transported within the plant. In roots, ovalbumin was associated with the epidermis when no root damage was evident, but with minor root damage, it was present in intercellular spaces throughout the cortex and at the endodermis. Ovalbumin was only found in the stem when minor damage to the root system was evident. Suspension cultures of wheat protoplasts revealed that ovalbumin was not assimilated into individual plant cells. Our results suggest that ovalbumin uptake and subsequent movement in wheat is possible only after root damage has occurred. Apoplastic movement may enable animal protein to enter plant tissues above the soil level where they could be consumed by grazers.

Self-Repairing Complex Helical Columns Generated via Kinetically Controlled Self-Assembly of Dendronized Perylene Bisimides

Percec, Virgil,Hudson, Steven D.,Peterca, Mihai,Leowanawat, Pawaret,Aqad, Emad,Graf, Robert,Spiess, Hans W.,Zeng, Xiangbing,Ungar, Goran,Heiney, Paul A. American Chemical Society 2011 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.133 No.45

<P>The dendronized perylene 3,4:9,10-tetracarboxylic acid bisimide (PBI), (3,4,5)12G1-3-PBI, was recently reported to self-assemble in complex helical columns containing tetramers of PBI as basic repeat unit. These tetramers contain a pair of two molecules arranged side-by-side and another pair in the next stratum of the column turned upside-down and rotated around the column axis. Intra- and intertetramer rotation angles and stacking distances are different. At high temperature, (3,4,5)12G1-3-PBI self-assembles via a thermodynamically controlled process in a 2D hexagonal columnar phase while at low temperature in a 3D orthorhombic columnar array via a kinetically controlled process. Here, we report the synthesis and structural analysis, by a combination of differential scanning calorimetry, X-ray and electron diffraction, and solid-state NMR performed at different temperatures, on the supramolecular structures generated by a library of (3,4,5)<I>n</I>G1-3-PBI with <I>n</I> = 14–4. For <I>n</I> = 11–8, the kinetically controlled self-assembly from low temperature changes in a thermodynamically controlled process, while the orthorhombic columnar array for <I>n</I> = 9 and 8 transforms from the thermodynamic product into the kinetic product. The new thermodynamic product at low temperature for <I>n</I> = 9, 8 is a self-repaired helical column with an intra- and intertetramer distance of 3.5 Å forming a 3D monoclinic periodic array via a kinetically controlled self-assembly process. The complex dynamic process leading to this reorganization was elucidated by solid-state NMR and X-ray diffraction. This discovery is important for the field of self-assembly and for the molecular design of supramolecular electronics and solar cell.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jacsat/2011/jacsat.2011.133.issue-45/ja208501d/production/images/medium/ja-2011-08501d_0011.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ja208501d'>ACS Electronic Supporting Info</A></P>

Conformational Analysis of Oxygen-Induced Higher Ordered Structure of A, B-Alternating Poly(arylene vinylene) Copolymers by Solid-State NMR and Molecular Dynamics Simulations

Jung, In-Sun,Lee, Young Joo,Jeong, Daun,Graf, Robert,Choi, Tae-Lim,Son, Won-Joon,Bulliard, Xavier,Spiess, Hans Wolfgang American Chemical Society 2016 Macromolecules Vol.49 No.8

<P>Two types of poly(arylene vinylene) copolymer derivatives, one containing heptoxy side chains and the other containing octyl side chains, are investigated by solid-state nuclear magnetic resonance (NMR) spectroscopy and molecular dynamics (MD) simulation in order to understand the effect of the chemical structure of the side chains on the molecular packing structure and the charge transport-properties. Solid-state NMR study shows that octyl-functionalized polymer has higher side chain mobility, indicating a higher degree of molecular stacking disorder than heptoxy-functionalized polymer. MD simulations suggest that these differences in molecular packing and mobility are associated with the different side chain geometry. Overall, we demonstrate how the new poly(arylene vinylene) copolymer derivatives with a small change-in polymer side chain (alkyl vs alkoxy) lead to large changes in the molecular packing arrangement and thereby the improved hole mobility in organic thin-film transistors.</P>

Self-Assembly of Dendronized Perylene Bisimides into Complex Helical Columns

Percec, Virgil,Peterca, Mihai,Tadjiev, Timur,Zeng, Xiangbing,Ungar, Goran,Leowanawat, Pawaret,Aqad, Emad,Imam, Mohammad R.,Rosen, Brad M.,Akbey, Umit,Graf, Robert,Sekharan, Sivakumar,Sebastiani, Danie American Chemical Society 2011 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.133 No.31

<P>The synthesis of perylene 3,4:9,10-tetracarboxylic acid bisimides (PBIs) dendronized with first-generation dendrons containing 0 to 4 methylenic units (<I>m</I>) between the imide group and the dendron, (3,4,5)12G1-<I>m</I>-PBI, is reported. Structural analysis of their self-organized arrays by DSC, X-ray diffraction, molecular modeling, and solid-state <SUP>1</SUP>H NMR was carried out on oriented samples with heating and cooling rates of 20 to 0.2 °C/min. At high temperature, (3,4,5)12G1-<I>m</I>-PBI self-assemble into 2D-hexagonal columnar phases with intracolumnar order. At low temperature, they form orthorhombic (<I>m</I> = 0, 2, 3, 4) and monoclinic (<I>m</I> = 1) columnar arrays with 3D periodicity. The orthorhombic phase has symmetry close to hexagonal. For <I>m</I> = 0, 2, 3, 4 ,they consist of tetramers as basic units. The tetramers contain a pair of two molecules arranged side by side and another pair in the next stratum of the column, turned upside-down and rotated around the column axis at different angles for different <I>m</I>. In contrast, for <I>m</I> = 1, there is only one molecule in each stratum, with a four-strata 2<SUB>1</SUB> helical repeat. All molecules face up in one column, and down in the second column, of the monoclinic cell. This allows close and extended π-stacking, unlike in the disruptive up–down alteration from the case of <I>m</I> = 0, 2, 3, 4. Most of the 3D structures were observed only by cooling at rates of 1 °C/min or less. This complex helical self-assembly is representative for other classes of dendronized PBIs investigated for organic electronics and solar cells.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jacsat/2011/jacsat.2011.133.issue-31/ja204366b/production/images/medium/ja-2011-04366b_0026.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ja204366b'>ACS Electronic Supporting Info</A></P>