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Kyle Spivack, Matthew Tucker, Devon Zimmerman, Matthew Nicholas, Osheiza Abdulmalik, Noelle Comolli, Jacob Elmer
Since donated red blood cells must be constantly refrigerated, they are often unavailable in remote areas and battlefields. The goal of this study was to synthesize a highly stable blood substitute that does not require refrigeration. Specifically, the extracellular haemoglobin (a.k.a. erythrocruorin, Ec) of the earthworm Lumbricus terrestris erythrocruororin (LtEc) was cross-linked with poly(acrylic acid) (PAA) and ethylene diamine (EDA). PAGE analysis of the LtEc nanoparticles reveals cross-linking between subunits, while dynamic light scattering and scanning electron microscopy show that cross-linking significantly increases the size of the LtEc nanoparticles (164 ± 13...
June 19, 2018: Artificial Cells, Nanomedicine, and Biotechnology
Fernando M Boubeta, Silvina A Bieza, Mauro Bringas, Darío A Estrin, Leonardo Boechi, Sara E Bari
The reaction of hydrogen sulfide (H2 S) with hemeproteins is a key physiological reaction; still, its mechanism and implications are not completely understood. In this work, we propose a combination of experimental and theoretical tools to shed light on the reaction in model system microperoxidase 11 (MP11-FeIII ) and myoglobin (Mb-FeIII ), from the estimation of the intrinsic binding constants of the species H2 S and hydrosulfide (HS- ), and the computational description of the overall binding process. Our results show that H2 S and HS- are the main reactive species in Mb-FeIII and MP11-FeIII , respectively, and that the magnitude of their intrinsic binding constants are similar to most of the binding constants reported so far for hemeproteins systems and model compounds...
June 19, 2018: Inorganic Chemistry
Xingliang Li, Zhicheng Zhang, Leigh R Martin, Shunzhong Luo, Linfeng Rao
N-(2-Hydroxyethyl)ethylenediamine- N, N', N'-triacetic acid (HEDTA, denoted as H3 L in this work, and the three dissociable protons represent those of the three carboxylic groups) is a strong chelating ligand and plays an important role in the treatment and disposal of nuclear wastes as well as separation sciences of f-elements. In this work, the complexation of HEDTA with U(VI) was studied thermodynamically and structurally in aqueous solutions. Potentiometry and microcalorimetry were used to measure the complexation constants (298-343 K) and enthalpies (298 K), respectively, at I = 1...
June 19, 2018: Inorganic Chemistry
Wolf-Ulrich Palm
Dark and photolysis reactions in solution were investigated for 9-acridinecarboxaldehyde (ACL). ACL reacts in the dark at T = 20 °C and pH = 7.0 in an air saturated solution to the main product 9-acridinecarboxylic acid (ACA) and to the minor product 9-acridinemethanol (ACM) with a lifetime of τ = 4.3 days. The dissociation constant of the base ACLH+ was determined to be pKa ± σ = 4.38 ± 0.04. The photolysis of ACL was investigated using a polychromatic Xe-light source. The quantum yield in aqueous solution at T = 20 °C in a concentration range of c0(ACL) = 0...
June 19, 2018: Photochemical & Photobiological Sciences
Xu Nan, Zhang Huihui, Zhong Haixiu, Wu Yining, Li Jinbo, Xin Li, Yin Zepeng, Zhu Wenxu, Qu Yi, Sun Guangyu
This paper selected clonal cutting seedlings from the F1 hybrid varieties of Physocarpus amurensis Maxim (♀) × P. opulifolius "Diabolo" (♂) as research material to study the response of the photosynthetic gas exchange parameters and chlorophyll fluorescence parameters of P. amurensis hybrids and their parental leaves to NaCl stress (with concentrations of 0, 50, 100, and 200 mmol⋅L-1 ). The results showed that under salt stress, the stomatal conductance ( G s ), transpiration rate ( T r ), and net photosynthetic rate ( P n ) of the three kinds of P...
2018: Frontiers in Plant Science
Sebastian Virreira Winter, Florian Meier, Christoph Wichmann, Juergen Cox, Matthias Mann, Felix Meissner
We developed EASI-tag (easily abstractable sulfoxide-based isobaric-tag), a new type of amine-derivatizing and sulfoxide-containing isobaric labeling reagents for highly accurate quantitative proteomics analysis using mass spectrometry. We observed that EASI-tag labels dissociate at low collision energy and generate peptide-coupled, interference-free reporter ions with high yield. Efficient isolation of 12 C precursors and quantification at the MS2 level allowed accurate determination of quantitative differences between up to six multiplexed samples...
June 18, 2018: Nature Methods
Viktor Rozsa, Ding Pan, Federico Giberti, Giulia Galli
The phase diagram of water at extreme conditions plays a critical role in Earth and planetary science, yet remains poorly understood. Here we report a first-principles investigation of the liquid at high temperature, between 11 GPa and 20 GPa-a region where numerous controversial results have been reported over the past three decades. Our results are consistent with the recent estimates of the water melting line below 1,000 K and show that on the 1,000-K isotherm the liquid is rapidly dissociating and recombining through a bimolecular mechanism...
June 18, 2018: Proceedings of the National Academy of Sciences of the United States of America
Brian M Sweis, Erin B Larson, A David Redish, Mark J Thomas
The nucleus accumbens shell (NAcSh) is involved in reward valuation. Excitatory projections from infralimbic cortex (IL) to NAcSh undergo synaptic remodeling in rodent models of addiction and enable the extinction of disadvantageous behaviors. However, how the strength of synaptic transmission of the IL-NAcSh circuit affects decision-making information processing and reward valuation remains unknown, particularly because these processes can conflict within a given trial and particularly given recent data suggesting that decisions arise from separable information-processing algorithms...
June 18, 2018: Proceedings of the National Academy of Sciences of the United States of America
Xun Sun, H Jane Dyson, Peter E Wright
Aggregation of transthyretin (TTR) is the causative agent for TTR cardiomyopathy and polyneuropathy amyloidoses. Aggregation is initiated by dissociation of the TTR tetramer into a monomeric intermediate, which self-assembles into amyloid. The coupled multiple-step equilibria and low-concentration, aggregation-prone intermediates are challenging to probe using conventional assays. We report a 19 F-NMR assay that leverages a highly sensitive trifluoroacetyl probe at a strategic site that gives distinct 19 F chemical shifts for the TTR tetramer and monomeric intermediate and enables direct quantification of their populations during the aggregation process...
June 18, 2018: Proceedings of the National Academy of Sciences of the United States of America
David C McDonald, Brendan C Sweeny, Shaun G Ard, Joshua J Melko, Jennifer E Ruliffson, Melanie C White, Albert A Viggiano, Nicholas S Shuman
The temperature dependent kinetics of Ni+ + O3 and of NiO+ + CH4/CD4 are measured from 300 - 600 K using a selected-ion flow tube apparatus. Together, these reactions comprise a catalytic cycle converting CH4 to CH3OH. The reaction of Ni+ + O3 proceeds at the collisional limit, faster than previously reported at 300 K. The NiO+ product reacts further with O3, also at the collisional limit, to yield both higher oxides (up to NiO5+ is observed) as well as undergoing an apparent reduction back to Ni+. This apparent reduction channel is due to the oxidation channel yielding NiO2+* with sufficient energy to dissociate...
June 18, 2018: Journal of Physical Chemistry. A
Elisabeth Hansson, Linda Block, Johan Forshammar, Christopher Lundborg, Björn Biber
Background Long-term or chronic pain represents a major health problem and is associated with significant socio-economic costs. During injury, pain can be dissociated from its normal physiological role. It can persist for a longer period of time, even after the primary noxious stimulus has more or less subsided. Analgesic drugs, with predominant neuronal sites of actions, seem to be relatively ineffective. Chronic pain is probably partly a consequence of ongoing neuroinflammation. The mechanisms behind these phenomena, and how the neuronal and non-neuronal activities evoked by painful stimuli and inflammation are processed in the brain and throughout the CNS, are not well understood...
December 29, 2017: Scandinavian Journal of Pain
Erik A Fransén, Peter J Ahlström
Aims Axonal hyperexcitability in peripheral nerves has been observed in patients with neuropathic pain [1]. The use-dependent propagation of double pulses, recovery cycles, was found to be different in patients relative to healthy controls. Methods We study the mechanisms underlying the recovery cycle phenomenon using a biophysical model of a C-fiber [2]. The model represents the spatial extent of the axon including its passive properties as well as ion channels of Hodgkin-Huxley type. In vitro voltage clamp recordings from dissociated small DRG somata from rat were performed to assess model predictions...
December 29, 2017: Scandinavian Journal of Pain
Caspar Skau Madsen, Nanna Brix Finnerup, Ulf Baumgärtner
Background and purpose Conventional neurophysiological techniques do not assess the function of nociceptive pathways and are inadequate to detect abnormalities in patients with small-fiber damage. This overview aims to give an update on the methods and techniques used to assess small fiber (Aδ- and C-fibers) function using evoked potentials in research and clinical settings. Methods Noxious radiant or contact heat allows the recording of heat-evoked brain potentials commonly referred to as laser evoked potentials (LEPs) and contact heat-evoked potentials (CHEPs)...
December 29, 2017: Scandinavian Journal of Pain
Anna-Maria Kuivalainen, Freja Ebeling, Per Rosenberg
Background and purpose Local infiltration anaesthesia is frequently painful due to low pH of the used anaesthetics, such as lidocaine. Usually pH of the solution is near 4.0, which causes tissue irritation and excitation of the pain mediating nerve endings. Warming and buffering the local anaesthetic solution have been shown to reduce the patient's experience of pain and unpleasantness during infiltration. Buffering reduces the dissociation of the local anaesthetic molecule and may enhance the anaesthetic's entrance into nerve cells...
December 29, 2017: Scandinavian Journal of Pain
Youmei Chen, Jing Xu, Li Zhou, Ya Zheng
BACKGROUND: Anhedonia, the reduced capacity to experience pleasure, has long been regarded as a cardinal symptom in depression and schizophrenia. Recent evidence highlights that anhedonia is not a single construct but consists of an anticipatory component and a consummatory component, which is captured by the Temporal Experience of Pleasure Scale (TEPS). The current event-related potential study examined the electrophysiological underpinnings of anticipatory and consummatory aspects of anhedonia as assessed by the TEPS in a non-clinical sample...
May 29, 2018: Journal of Affective Disorders
Ekaterina A Proshina, Alexander N Savostyanov, Andrey V Bocharov, Gennady G Knyazev
The S allele of serotonin transporter gene (5-HTTLPR) has been found to increase the risk of depression and other mental health problems, but some evidence suggests that S-allele carriers outperform subjects carrying the long allele in an array of cognitive tasks. Evidence linking this polymorphism with individual variation in electrophysiological properties of resting state brain networks is very limited. This study investigated the effect of 5-HTTLPR polymorphism on EEG current source density, connectivity, and topological properties of resting state networks...
June 15, 2018: Brain Research
Fanmao Liu, Ignasi Fina, Guillaume Sauthier, Florencio Sanchez, Andrew M Rappe, Josep Fontcuberta
Ferroelectric perovskites hold promise of enhanced photovoltaic efficiency and photocatalytic activity. Consequently, the photoresponse of oxide ferroelectric thin films is an active field of research. In electrode/ferroelectric/electrode devices, internal charge in the ferroelectric, free charge in the electrodes, and buried adsorbates at interfaces combine to screen the ferroelectric polarization and to stabilize the polar state. Under illumination, photo-induced carriers and photo-dissociated adsorbates may disrupt the screening equilibrium, modifying the switchable polarization and altering its expected benefits...
June 18, 2018: ACS Applied Materials & Interfaces
Sara Jahfari, K Richard Ridderinkhof, Anne G E Collins, Tomas Knapen, Lourens J Waldorp, Michael J Frank
Why are we so slow in choosing the lesser of 2 evils? We considered whether such slowing relates to uncertainty about the value of these options, which arises from the tendency to avoid them during learning, and whether such slowing relates to frontosubthalamic inhibitory control mechanisms. In total, 49 participants performed a reinforcement-learning task and a stop-signal task while fMRI was recorded. A reinforcement-learning model was used to quantify learning strategies. Individual differences in lose-lose slowing related to information uncertainty due to sampling, and independently, to less efficient response inhibition in the stop-signal task...
April 18, 2018: Cerebral Cortex
Marissa A Scavuzzo, Jessica Teaw, Diane Yang, Malgorzata Borowiak
The pancreas is a complex organ composed of many different cell types that work together to regulate blood glucose homeostasis and digestion. These cell types include enzyme-secreting acinar cells, an arborized ductal system responsible for the transportation of enzymes to the gut, and hormone-producing endocrine cells. Endocrine beta-cells are the sole cell type in the body that produce insulin to lower blood glucose levels. Diabetes, a disease characterized by a loss or the dysfunction of beta-cells, is reaching epidemic proportions...
June 2, 2018: Journal of Visualized Experiments: JoVE
Daud Tai Shan Chou, Ibraheim El-Daly, Arun Ranganathan, Alexander Montgomery, Paul Culpan, Peter Bates
INTRODUCTION: Spinopelvic dissociation is a rare injury resulting in discontinuity between the spine and pelvis. We review the English- language literature and discuss critical treatment controversies. We present a series of spinopelvic dissociation cases from a level I trauma center. METHODS: In this retrospective review of 18 consecutive cases treated surgically over a period of 4 years, we collected patient, injury, and surgical demographics and clinical and radiographic outcome measures...
June 14, 2018: Journal of the American Academy of Orthopaedic Surgeons
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