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Laura Sordo, Rui Santos, Joao Reis, Alona Shulika, Joao Silva
Most ocean acidification (OA) experimental systems rely on pH as an indirect way to control CO2. However, accurate pH measurements are difficult to obtain and shifts in temperature and/or salinity alter the relationship between pH and pCO2. Here we describe a system in which the target pCO2 is controlled via direct analysis of pCO2 in seawater. This direct type of control accommodates potential temperature and salinity shifts, as the target variable is directly measured instead of being estimated. Water in a header tank is permanently re-circulated through an air-water equilibrator...
2016: PeerJ
Ester Vázquez-Fernández, Matthijn R Vos, Pavel Afanasyev, Lino Cebey, Alejandro M Sevillano, Enric Vidal, Isaac Rosa, Ludovic Renault, Adriana Ramos, Peter J Peters, José Jesús Fernández, Marin van Heel, Howard S Young, Jesús R Requena, Holger Wille
The structure of the infectious prion protein (PrPSc), which is responsible for Creutzfeldt-Jakob disease in humans and bovine spongiform encephalopathy, has escaped all attempts at elucidation due to its insolubility and propensity to aggregate. PrPSc replicates by converting the non-infectious, cellular prion protein (PrPC) into the misfolded, infectious conformer through an unknown mechanism. PrPSc and its N-terminally truncated variant, PrP 27-30, aggregate into amorphous aggregates, 2D crystals, and amyloid fibrils...
September 2016: PLoS Pathogens
Engin Baysoy, Dursun Korel Yildirim, Cagla Ozsoy, Senol Mutlu, Ozgur Kocaturk
OBJECTIVES: A new microfabrication method to produce low profile radio frequency (RF) resonant markers on catheter shafts was developed. A semi-active RF resonant marker incorporating a solenoid and a plate capacitor was constructed on the distal shaft of a 5 Fr guiding catheter. The resulting device can be used for interventional cardiovascular MRI procedures. MATERIALS AND METHODS: Unlike current semi-active device visualization techniques that require rigid and bulky analog circuit components (capacitor and solenoid), we fabricated a low profile RF resonant marker directly on guiding the catheter surface by thin film metal deposition and electroplating processes using a modified physical vapor deposition system...
September 7, 2016: Magma
Chang Jiang, Troy A Lionberger, Diane M Wiener, Edgar Meyhofer
Magnetic tweezers are powerful tools to manipulate and study the mechanical properties of biological molecules and living cells. In this paper we present a novel, bona fide electromagnetic tweezer (EMT) setup that allows independent control of the force and torque applied via micrometer-sized magnetic beads to a molecule under study. We implemented this EMT by combining a single solenoid that generates force (f-EMT) with a set of four solenoids arranged into a symmetric quadrupole to generate torque (τ-EMT)...
August 2016: Review of Scientific Instruments
James T MacDonald, Burak V Kabasakal, David Godding, Sebastian Kraatz, Louie Henderson, James Barber, Paul S Freemont, James W Murray
The ability to design and construct structures with atomic level precision is one of the key goals of nanotechnology. Proteins offer an attractive target for atomic design because they can be synthesized chemically or biologically and can self-assemble. However, the generalized protein folding and design problem is unsolved. One approach to simplifying the problem is to use a repetitive protein as a scaffold. Repeat proteins are intrinsically modular, and their folding and structures are better understood than large globular domains...
September 13, 2016: Proceedings of the National Academy of Sciences of the United States of America
Martin Ston, Radomir Cabala, Vaclav Matej Bierhanzl, Jan Krajicek, Zuzana Bosakova
Improvement and testing of a flow modulator for the application in comprehensive two-dimensional gas chromatography separations is the subject of the presented paper. This improved setup constructed from two independent capillary branches each consisting of a pressure regulator, a pressure sensor, a two-way solenoid valve and a microfluidic T-connector, allows an independent and easy settings of the pressures and flow velocities in the modulator and provides system flexibility in an operation without need of any component exchange...
August 18, 2016: Journal of Chromatographic Science
Barret Daniels, Christopher Ireland, Steven Kraus, John Racadio, Nicole Hilvert, Richard Dunn, Charles Dumoulin
BACKGROUND: Establishing postnatal nutrition delivery is challenging in neonates with immature sucking and swallowing ability. Enteral feeding is the gold standard for such patients, but their small size and fragility present challenges in nasogastric (NG) feeding tube placement. Feeding tubes are typically placed with x-ray guidance, which provides minimal soft tissue contrast and exposes the baby to ionizing radiation. This research investigates magnetic resonance (MR) guidance of NG feeding tube placement in neonates to provide improved soft tissue visualization without ionizing radiation...
August 8, 2016: JPEN. Journal of Parenteral and Enteral Nutrition
Timothy V Kirk, Marco Pc Marques, Anand N Pallipurath Radhakrishnan, Nicolas Szita
BACKGROUND: Microbioreactors have emerged as a new tool for early bioprocess development. The technology has advanced rapidly in the last decade and obtaining real-time quantitative data of process variables is nowadays state of the art. In addition, control over process variables has also been achieved. The aim of this study was to build a microbioreactor capable of controlling dissolved oxygen (DO) concentrations and to determine oxygen uptake rate in real time. RESULTS: An oscillating jet driven, membrane-aerated microbioreactor was developed without comprising any moving parts...
March 2016: Journal of Chemical Technology and Biotechnology
Dilshadbek T Usmanov, Kenzo Hiraoka
RATIONALE: For the development of on-site mass spectrometry for security and safety, point-of-care analysis, etc., the gas volume introduced into the vacuum should be reduced to a minimum. To cope with this demand, a discontinuous atmospheric pressure interface using a solenoid pulse valve was developed. METHODS: The sample gas was introduced discontinuously into the ionization cell with a volume of 0.17 cm(3) . The sampled gas in the cell was ionized by an alternating current (ac) corona discharge...
August 30, 2016: Rapid Communications in Mass Spectrometry: RCM
Shima Fardad, Alessandro Salandrino, Akbar Samadi, Matthias Heinrich, Zhigang Chen, Demetrios N Christodoulides
The Poynting vector S plays a central role in electrodynamics as it is directly related to the power and the momentum carried by an electromagnetic wave. In the presence of multiple electromagnetic waves with different polarizations and propagation directions, the Poynting vector may exhibit solenoidal components which are not associated to any power flow. Here, we demonstrate theoretically and experimentally that the presence of such solenoidal components has physical consequences, and it is not a mere artifact of the gauge invariance of S...
August 1, 2016: Optics Letters
Markus Kornprobst, Martin Turk, Nikola Kellner, Jingdong Cheng, Dirk Flemming, Isabelle Koš-Braun, Martin Koš, Matthias Thoms, Otto Berninghausen, Roland Beckmann, Ed Hurt
The 90S pre-ribosome is an early biogenesis intermediate formed during co-transcriptional ribosome formation, composed of ∼70 assembly factors and several small nucleolar RNAs (snoRNAs) that associate with nascent pre-rRNA. We report the cryo-EM structure of the Chaetomium thermophilum 90S pre-ribosome, revealing how a network of biogenesis factors including 19 β-propellers and large α-solenoid proteins engulfs the pre-rRNA. Within the 90S pre-ribosome, we identify the UTP-A, UTP-B, Mpp10-Imp3-Imp4, Bms1-Rcl1, and U3 snoRNP modules, which are organized around 5'-ETS and partially folded 18S rRNA...
July 14, 2016: Cell
Ognjen Perišić, Tamar Schlick
While the genetic information is contained in double helical DNA, gene expression is a complex multilevel process that involves various functional units, from nucleosomes to fully formed chromatin fibers accompanied by a host of various chromatin binding enzymes. The chromatin fiber is a polymer composed of histone protein complexes upon which DNA wraps, like yarn upon many spools. The nature of chromatin structure has been an open question since the beginning of modern molecular biology. Many experiments have shown that the chromatin fiber is a highly dynamic entity with pronounced structural diversity that includes properties of idealized zig-zag and solenoid models, as well as other motifs...
2016: Physical Biology
Thomas Hrabe, Lukasz Jaroszewski, Adam Godzik
MOTIVATION: Repeat proteins, which contain multiple repeats of short sequence motifs, form a large but seldom-studied group of proteins. Methods focusing on the analysis of 3D structures of such proteins identified many subtle effects in length distribution of individual motifs that are important for their functions. However, similar analysis was yet not applied to the vast majority of repeat proteins with unknown 3D structures, mostly because of the extreme diversity of the underlying motifs and the resulting difficulty to detect those...
September 15, 2016: Bioinformatics
Gualtiero Alvisi, David A Jans
No abstract text is available yet for this article.
June 2016: Acta Crystallographica. Section D, Structural Biology
Maher M Kassem, Yong Wang, Wouter Boomsma, Kresten Lindorff-Larsen
Bactofilins constitute a recently discovered class of bacterial proteins that form cytoskeletal filaments. They share a highly conserved domain (DUF583) of which the structure remains unknown, in part due to the large size and noncrystalline nature of the filaments. Here, we describe the atomic structure of a bactofilin domain from Caulobacter crescentus. To determine the structure, we developed an approach that combines a biophysical model for proteins with recently obtained solid-state NMR spectroscopy data and amino acid contacts predicted from a detailed analysis of the evolutionary history of bactofilins...
June 7, 2016: Biophysical Journal
Marcos Tadeu Geraldo, Agnes Alessandra Sekijima Takeda, Antônio Sérgio Kimus Braz, Ney Lemke
Alpha solenoid proteins play a key role in regulating the classical nuclear import pathway, recognizing a target protein and transporting it into the nucleus. Importin-α (Impα) is the solenoid responsible for cargo protein recognition, and it has been extensively studied by X-ray crystallography to understand the binding specificity. To comprehend the main motions of Impα and to extend the information about the critical interactions during carrier-cargo recognition, we surveyed different conformational states based on molecular dynamics (MD) and normal mode (NM) analyses...
2016: PloS One
I Kvachadze, A Tsibadze, G Sanadiradze, D Mzhavanadze, G Chichinadze
The aim of the study was to evaluate the vegetative regulatory action in healthy, untrained and trained individuals in different geomagnetic conditions. The study involved 94 healthy untrained young men aged 18-22 years - I group (control), and 60 trained volunteers aged 18-25 years - II group, who during the period of the study and for at least three years prior have been following active regular physical exercise regimen(weight lifting), but were not professional athletes. In order to evaluate the heart rate variability the following statistical indicators were studied: arithmetic mean, the arithmetic mean of the error variance, dispersion, the arithmetic mean deviation, coefficient of skewness, kurtosis, standard deviation of the mean...
April 2016: Georgian Medical News
Xuejuan Wang, Huanyu Chu, Mengjuan Lv, Zhihui Zhang, Shuwan Qiu, Haiyan Liu, Xuetong Shen, Weiwu Wang, Gang Cai
The ataxia-telangiectasia mutated (ATM) protein is an apical kinase that orchestrates the multifaceted DNA-damage response. Normally, ATM kinase is in an inactive, homodimer form and is transformed into monomers upon activation. Besides a conserved kinase domain at the C terminus, ATM contains three other structural modules, referred to as FAT, FATC and N-terminal helical solenoid. Here we report the first cryo-EM structure of ATM kinase, which is an intact homodimeric ATM/Tel1 from Schizosaccharomyces pombe...
2016: Nature Communications
Michał Michalec, Łukasz Tymecki, Robert Koncki
A general concept for the development of flow analysis system for non-invasive, bloodless monitoring of uremic toxins' removal in the course of clinical hemodialysis treatment is presented. The monitor operates in both (discrete and continuous) modes of measurements. In this study as a model uremic marker creatinine has been chosen. The monitor is based on solenoid operated microdevices (pumps and valves) and an optoelectronic flow-through detector made of paired light emitting diodes allowing photometric determination of this metabolite using Jaffé method...
September 5, 2016: Journal of Pharmaceutical and Biomedical Analysis
Ming Cong, Xinjun Wu, Chunqiao Qian
A new electromagnetic acoustic transducer (EMAT) design, employing a special structure of the permanent magnet chain, is proposed to generate and receive longitudinal guided waves for pipe inspection based on the magnetostriction mechanism. Firstly, a quantitative analysis of the excitation forces shows the influence of the radial component can be ignored. Furthermore, as the axial component of the static magnetic field is dominant, a method of solenoid testing coils connected in series is adopted to increase the signal amplitude...
2016: Sensors
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