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Rods and rings

Wen-Yong Lai, Cheng Cheng, Yi Jiang, Cheng-Fang Liu, Jian-Dong Zhang, Wei Huang
A novel set of star-shaped polycyclic aromatic hydrocarbons (PAHs) based on naphthalenes-fused truxenes, named as TrNaCn (n = 1-4), were synthesized and characterized. Oxidative cyclodehydrogenation was carried out following the microwave-assisted six-fold Suzuki coupling reaction. It is worthwhile to mention that multiple dehydrocyclization samples can be isolated effectively in one reaction, suggesting that the oxidative cyclodehydrogenation was a stepwise ring-closed process. Thermal, optical, and electrochemical properties, and self-assembly behaviors of the resulting oxidized samples were investigated to understand the impact of the ring-fused process on the properties of star-shaped PAHs...
October 18, 2016: Chemistry, An Asian Journal
Zhenyu Deng, Yangwei Jiang, Linli He, Linxi Zhang
By employing molecular dynamics simulations, we explored the conformation transition of nanoparticles (NPs) in semiflexible ring polymer nanocomposite melts. A novel aggregation- dispersion transition for NPs in ring polymer nanocomposites occurs when the bending energy of ring chains increases. The conformations of flexible ring chains near NPs are radial distribution, and the entropic depletion interactions between a pair of NPs in flexible ring polymer nanocomposite melts are attractive, however, the rod-like ring chains are wrapped around the NPs and the entropic depletion interactions between NPs in rod-like ring polymer melts are repulsive...
October 18, 2016: Journal of Physical Chemistry. B
Chun Bi, Qiugen Wang, Christopher Nagelli, Jianhong Wu, Qian Wang, Jiandong Wang
BACKGROUND The aim of this study was to assess the clinical results of treatment for unstable posterior pelvic fractures using a pedicle screw-rod fixator compared to use of a locking compression plate. MATERIAL AND METHODS A retrospective study was performed between June 2010 and May 2014 and the data were collected from 46 patients with unstable posterior pelvic ring fractures. All patients were treated using either a pedicle screw-rod fixator (study group, 24 patients) or locking compression plate (control group, 22 patients)...
October 17, 2016: Medical Science Monitor: International Medical Journal of Experimental and Clinical Research
Gerson Dierley Keppeke, Monica Simon Prado, Eunice Nunes, Sandro Felix Perazzio, Silvia Helena Rodrigues, Maria Lucia Gomes Ferraz, Edward K L Chan, Luis Eduardo Coelho Andrade
Some HCV patients using ribavirin and interferon alpha (IFN-α) develop anti-rods and rings (RR) autoantibodies, the main target of which is inosine monophosphate dehydrogenase (IMPDH), the rate-determining enzyme in de novo GTP biosynthesis. In vitro inhibition of IMPDH by ribavirin induces RR formation. Here we investigate whether other commonly used drugs that interfere with GTP biosynthesis can induce RR structures in vitro and vivo and elicit generation of autoantibodies. HEp-2 cells treated for 24h with ribavirin, mycophenolic acid (MPA), azathioprine, methotrexate or acyclovir were positive for RR structures...
October 13, 2016: Clinical Immunology: the Official Journal of the Clinical Immunology Society
Nikolaus Leisch, Nika Pende, Philipp M Weber, Harald R Gruber-Vodicka, Jolanda Verheul, Norbert O E Vischer, Sophie S Abby, Benedikt Geier, Tanneke den Blaauwen, Silvia Bulgheresi
The reproduction mode of uncultivable microorganisms deserves investigation as it can largely diverge from conventional transverse binary fission. Here, we show that the rod-shaped gammaproteobacterium thriving on the surface of the Robbea hypermnestra nematode divides by FtsZ-based, non-synchronous invagination of its poles-that is, the host-attached and fimbriae-rich pole invaginates earlier than the distal one. We conclude that, in a naturally occurring animal symbiont, binary fission is host-oriented and does not require native FtsZ to polymerize into a ring at any septation stage...
October 10, 2016: Nature Microbiology
Sei Yano, Yasuchika Aoki, Atsuya Watanabe, Takayuki Nakajima, Makoto Takazawa, Hiroyuki Hirasawa, Kazuhisa Takahashi, Koichi Nakagawa, Arata Nakajima, Hiroshi Takahashi, Sumihisa Orita, Yawara Eguchi, Takane Suzuki, Seiji Ohtori
Pelvic ring fractures are defined as life-threatening injuries that can be treated surgically with external or internal fixation. The authors report on an 81-year-old woman with an unstable pelvic fracture accompanying multiple traumas that was successfully treated with a less invasive procedure. The patient was injured in a traffic accident and sustained a total of 20 fractures, including pelvic ring, bilateral rib, and lumbar transverse processes fractures, and multiple fractures of both upper and lower extremities...
October 7, 2016: Journal of Neurosurgery. Spine
Afshin Vahid, Timon Idema
Membrane tubes and tubular networks are ubiquitous in living cells. Inclusions like proteins are vital for both the stability and the dynamics of such networks. These inclusions interact via the curvature deformations they impose on the membrane. We analytically study the resulting membrane mediated interactions in strongly curved tubular membranes. We model inclusions as constraints coupled to the curvature tensor of the membrane tube. First, as special test cases, we analyze the interaction between ring- and rod-shaped inclusions...
September 23, 2016: Physical Review Letters
James Richman, Adam Cota, Steven Weinfeld
BACKGROUND: Surgical strategies to address deformities of the ankle and hindfoot in patients with Charcot arthropathy include the use of retrograde intramedullary nails and ring fixators. The literature has not shown superiority of one technique over the other. This study presents a single surgeon's case series of Charcot arthropathy patients treated with either a ring fixator or retrograde intramedullary nail to achieve tibiotalocalcaneal arthrodesis. METHODS: We performed a retrospective analysis of 27 consecutive patients with Charcot arthropathy who underwent a tibiotalocalcaneal arthrodesis using either a retrograde intramedullary (IM) nail (n = 16 patients) or a ring fixator (RF) (n = 11 patients) by a single surgeon...
October 2, 2016: Foot & Ankle International
Mihori Baba, Kousuke Iwamoto, Ryota Iino, Hiroshi Ueno, Mayu Hara, Atsuko Nakanishi, Jun-Ichi Kishikawa, Hiroyuki Noji, Ken Yokoyama
F1- and V1-ATPase are rotary molecular motors that convert chemical energy released upon ATP hydrolysis into torque to rotate a central rotor axle against the surrounding catalytic stator cylinder with high efficiency. How conformational change occurring in the stator is coupled to the rotary motion of the axle is the key unknown in the mechanism of rotary motors. Here, we generated chimeric motor proteins by inserting an exogenous rod protein, FliJ, into the stator ring of F1 or of V1 and tested the rotation properties of these chimeric motors...
October 4, 2016: Proceedings of the National Academy of Sciences of the United States of America
Saikat Ghosh, Nihar R Pradhan, Hamid Mashayekhi, Qiu Zhang, Bo Pan, Baoshan Xing
Environmental mobility of C60 fullerene can be significantly affected in the presence of naturally abundant α-FeOOH. However, α-FeOOH vary significantly in sizes, shapes and associated properties that can greatly influence the fate and transport of C60 fullerene in environmental media. Therefore, colloidal hetero-association between well crystallized low aspect (LAsp) α-FeOOH and nC60 fullerene may differ substantially to weakly crystallized high-aspect (HAsp) counterpart. In contrast to LAsp α-FeOOH, inherent crystal defects and surface charge generation in HAsp α-FeOOH facilitated strong Coulombic attraction and aggregation with fullerene in acidic pH...
September 13, 2016: Environmental Pollution
Emmanuelle R J Quemin, Petr Chlanda, Martin Sachse, Patrick Forterre, David Prangishvili, Mart Krupovic
UNLABELLED: Similar to many eukaryotic viruses (and unlike bacteriophages), viruses infecting archaea are often encased in lipid-containing envelopes. However, the mechanisms of their morphogenesis and egress remain unexplored. Here, we used dual-axis electron tomography (ET) to characterize the morphogenesis of Sulfolobus spindle-shaped virus 1 (SSV1), the prototype of the family Fuselloviridae and representative of the most abundant archaea-specific group of viruses. Our results show that SSV1 assembly and egress are concomitant and occur at the cellular cytoplasmic membrane via a process highly reminiscent of the budding of enveloped viruses that infect eukaryotes...
2016: MBio
Irina Kulemzina, Keven Ang, Xiaodan Zhao, Jun-Thing Teh, Vikash Verma, Sasikala Suranthran, Alap P Chavda, Roland G Huber, Birgit Eisenhaber, Frank Eisenhaber, Jie Yan, Dmitri Ivanov
Cohesin is a ring-shaped protein complex that is capable of embracing DNA. Most of the ring circumference is comprised of the anti-parallel intramolecular coiled coils of the Smc1 and Smc3 proteins, which connect globular head and hinge domains. Smc coiled coil arms contain multiple acetylated and ubiquitylated lysines. To investigate the role of these modifications, we substituted lysines for arginines to mimic the unmodified state and uncovered genetic interaction between the Smc arms. Using scanning force microscopy, we show that wild-type Smc arms associate with each other when the complex is not on DNA...
September 15, 2016: Molecular Cell
Ana R Pereira, Jen Hsin, Ewa Król, Andreia C Tavares, Pierre Flores, Egbert Hoiczyk, Natalie Ng, Alex Dajkovic, Yves V Brun, Michael S VanNieuwenhze, Terry Roemer, Rut Carballido-Lopez, Dirk-Jan Scheffers, Kerwyn Casey Huang, Mariana G Pinho
UNLABELLED: A mechanistic understanding of the determination and maintenance of the simplest bacterial cell shape, a sphere, remains elusive compared with that of more complex shapes. Cocci seem to lack a dedicated elongation machinery, and a spherical shape has been considered an evolutionary dead-end morphology, as a transition from a spherical to a rod-like shape has never been observed in bacteria. Here we show that a Staphylococcus aureus mutant (M5) expressing the ftsZ(G193D) allele exhibits elongated cells...
2016: MBio
Dae Yup Han, Habib Safigholi, Abraam Soliman, Ananth Ravi, Eric Leung, Daniel J Scanderbeg, Zhaowei Liu, Amir Owrangi, William Y Song
PURPOSE: To perform a comprehensive comparative planning study evaluating the utility of the proposed direction modulated brachytherapy (DMBT) tandem applicator against standard applicators, in the setting of image guided adaptive brachytherapy of cervical cancer. METHODS AND MATERIALS: A detailed conceptual article was published in 2014. The proposed DMBT tandem applicator has 6 peripheral grooves of 1.3-mm width, along a 5.4-mm-thick nonmagnetic tungsten alloy rod of density 18...
October 1, 2016: International Journal of Radiation Oncology, Biology, Physics
Chia-Hsiang Chen, Laura Abella, Maira R Cerón, Miguel A Guerrero-Ayala, Antonio Rodríguez-Fortea, Marilyn M Olmstead, Xian B Powers, Alan L Balch, Josep M Poblet, Luis Echegoyen
A non-isolated pentagon rule metallic carbide clusterfullerene containing a heptagonal ring, Sc2C2@Cs(hept)-C88, was isolated from the raw soot obtained by electric arc vaporization of graphite rods packed with Sc2O3 and graphite powder under a helium atmosphere. The Sc2C2@Cs(hept)-C88 was purified by multistage high-performance liquid chromatography (HPLC), cocrystallized with Ni-(octaethylporphyrin), and characterized by single-crystal X-ray diffraction. The diffraction data revealed a zigzag Sc2C2 unit inside an unprecedented Cs(hept)-C88 carbon cage containing 13 pentagons, 32 hexagons, and 1 heptagon...
October 5, 2016: Journal of the American Chemical Society
T Apivatthakakul, N Rujiwattanapong
INTRODUCTION: Anterior pelvic internal fixator (INFIX) is used to treat unstable pelvic ring injuries. Nerve injury complications with this procedure have been reported. OBJECTIVES: This anatomic study attempted to identify structures at risk after application of INFIX. MATERIALS AND METHODS: INFIX was applied in fifteen fresh, frozen, anatomical specimens using polyaxial pedicular screws and subcutaneous rods. Surgical dissection was done to identify the structures at risk including the femoral nerve (FN), femoral artery (FA), femoral vein (FV) and the lateral femoral cutaneous nerve (LFCN) related to which are potentially affected by the implant...
October 2016: Injury
Carlos Avendaño, George Jackson, Erich A Müller, Fernando A Escobedo
Materials comprising porous structures, often in the form of interconnected concave cavities, are typically assembled from convex molecular building blocks. The use of nanoparticles with a characteristic nonconvex shape provides a promising strategy to create new porous materials, an approach that has been recently used with cagelike molecules to form remarkable liquids with "scrabbled" porous cavities. Nonconvex mesogenic building blocks can be engineered to form unique self-assembled open structures with tunable porosity and long-range order that is intermediate between that of isotropic liquids and of crystalline solids...
August 30, 2016: Proceedings of the National Academy of Sciences of the United States of America
Laureen M Lopez, Alissa Bernholc, Mario Chen, Thomas W Grey, Conrad Otterness, Carolyn Westhoff, Alison Edelman, Frans M Helmerhorst
BACKGROUND: Obesity has reached epidemic proportions around the world. Effectiveness of hormonal contraceptives may be related to metabolic changes in obesity or to greater body mass or body fat. Hormonal contraceptives include oral contraceptives (OCs), injectables, implants, hormonal intrauterine contraception (IUC), the transdermal patch, and the vaginal ring. Given the prevalence of overweight and obesity, the public health impact of any effect on contraceptive efficacy could be substantial...
2016: Cochrane Database of Systematic Reviews
Amir Sheikhi, Han Yang, Md Nur Alam, Theo G M van de Ven
Nanoparticles, as one of the key materials in nanotechnology and nanomedicine, have gained significant importance during the past decade. While metal-based nanoparticles are associated with synthetic and environmental hassles, cellulose introduces a green, sustainable alternative for nanoparticle synthesis. Here, we present the chemical synthesis and separation procedures to produce new classes of hairy nanoparticles (bearing both amorphous and crystalline regions) and biopolymers based on wood fibers. Through periodate oxidation of soft wood pulp, the glucose ring of cellulose is opened at the C2-C3 bond to form 2,3-dialdehyde groups...
2016: Journal of Visualized Experiments: JoVE
T Porter, D Frederick, E Johnson, P G Jones
As similarly observed in nutrient-poor media at 37°C, Escherichia coli forms small rods in nutrient-rich media at temperatures near 8°C, the minimum temperature of growth. A study was initiated to identify proteins required to facilitate the small rod morphology at low temperature. E. coli contains three nonessential SPOR domain proteins (DamX, RlpA, and DedD) that have been demonstrated to bind to the septal ring. In contrast to the normal growth and small rod morphology of damX and rlpA null mutants at 10°C, the dedD null mutant exhibited reduced growth and formed filamentous cells...
September 12, 2016: Journal of General and Applied Microbiology
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