bluuebunny/crossref_metadata_2025_split huggingface dataset:
El'gygytgyn impact crater, Chukotka, Arctic Russia: Impact cratering aspects of the 2009 ICDP drilling project
Authors: Koeberl Christian , Pittarello Lidia , Reimold Wolf Uwe , Raschke Ulli , Brigham‐Grette Julie , Melles Martin , Minyuk Pavel 
Published: July 2013

AbstractThe El'gygytgyn impact structure in Chukutka, Arctic Russia, is the only impact crater currently known on Earth that was formed in mostly acid volcanic rocks (mainly of rhyolitic, with some andesitic and dacitic, compositions). In addition, because of its depth, it has provided an excellent sediment trap that records paleoclimatic information for the 3.6 Myr since its formation. For these two main reasons, because of the importance for impact and paleoclimate research, El'gygytgyn was the subject of an International Continental Scientific Drilling Program (ICDP) drilling project in 2009. During this project, which, due to its logistical and financial challenges, took almost a decade to come to fruition, a total of 642.3 m of drill core was recovered at two sites, from four holes. The obtained material included sedimentary and impactite rocks. In terms of impactites, which were recovered from 316.08 to 517.30 m depth below lake bottom (mblb), three main parts of that core segment were identified: from 316 to 390 mblb polymict lithic impact breccia, mostly suevite, with volcanic and impact melt clasts that locally contain shocked minerals, in a fine‐grained clastic matrix; from 385 to 423 mblb, a brecciated sequence of volcanic rocks including both felsic and mafic (basalt) members; and from 423 to 517 mblb, a greenish rhyodacitic ignimbrite (mostly monomict breccia). The uppermost impactite (316–328 mblb) contains lacustrine sediment mixed with impact‐affected components. Over the whole length of the impactite core, the abundance of shock features decreases rapidly from the top to the bottom of the studied core section. The distinction between original volcanic melt fragments and those that formed later as the result of the impact event posed major problems in the study of these rocks. The sequence that contains fairly unambiguous evidence of impact melt (which is not very abundant anyway, usually less than a few volume%) is only about 75 m thick. The reason for this rather thin fallback impactite sequence may be the location of the drill core on an elevated part of the central uplift. A general lack of large coherent melt bodies is evident, similar to that found at the similarly sized Bosumtwi impact crater in Ghana that, however, was formed in a target composed of a thin layer of sediment above crystalline rocks.
The Ktr potassium transport system in Staphylococcus aureus and its role in cell physiology, antimicrobial resistance and pathogenesis
Authors: Gries Casey M. , Bose Jeffrey L. , Nuxoll Austin S. , Fey Paul D. , Bayles Kenneth W. 
Published: July 2013

SummaryPotassium (K+) plays a vital role in bacterial physiology, including regulation of cytoplasmic pH, turgor pressure and transmembrane electrical potential. Here, we examine the Staphylococcus aureus Ktr system uniquely comprised of two ion‐conducting proteins (KtrB and KtrD) and only one regulator (KtrA). Growth of Ktr system mutants was severely inhibited under K+ limitation, yet detectable after an extended lag phase, indicating the presence of a secondary K+ transporter. Disruption of both ktrA and the Kdp‐ATPase system, important for K+ uptake in other organisms, eliminated regrowth in 0.1 mM K+, demonstrating a compensatory role for Kdp to the Ktr system. Consistent with K+ transport mutations, S. aureus devoid of the Ktr system became sensitive to hyperosmotic conditions, exhibited a hyperpolarized plasma membrane, and increased susceptibility to aminoglycoside antibiotics and cationic antimicrobials. In contrast to other organisms, the S. aureus Ktr system was shown to be important for low‐K+ growth under alkaline conditions, but played only a minor role in neutral and acidic conditions. In a mouse competitive index model of bacteraemia, the ktrA mutant was significantly outcompeted by the parental strain. Combined, these results demonstrate a primary mechanism of K+ uptake in S. aureus and a role for this system in pathogenesis.
Decreased coenzyme A levels in ridA mutant strains of Salmonella enterica result from inactivated serine hydroxymethyltransferase
Authors: Flynn Jeffrey M. , Christopherson Melissa R. , Downs Diana M. 
Published: July 2013

SummaryThe RidA/Yer057/UK114 family of proteins is well represented across the domains of life and recent work has defined both an in vitro activity and an in vivo role for RidA. RidA proteins have enamine deaminase activity, and in their absence the reactive 2‐aminoacrylate (2‐AA) accumulates and inactivates at least some pyridoxal 5′‐phosphate (PLP)‐containing enzymes in Salmonella enterica. The conservation of RidA suggested that 2‐AA was a ubiquitous cellular stressor that was generated in central metabolism. Phenotypically, strains of S. enterica that lack RidA accumulated significantly more pyruvate in the growth medium than wild‐type strains. Here we dissected this ridA mutant phenotype and showed it was an indirect consequence of damage to serine hydroxymethyltransferase (GlyA; E.C. 2.1.2.1). The results here identified a fourth PLP enzyme as a target of enamine stress in Salmonella.
Metabolism of dimethylsulphoniopropionate by Ruegeria pomeroyi DSS‐3
Authors: Reisch Chris R. , Crabb Warren M. , Gifford Scott M. , Teng Quincy , Stoudemayer Melissa J. , Moran Mary Ann , Whitman William B. 
Published: July 2013

SummaryRuegeria pomeroyi DSS‐3 possesses two general pathways for metabolism of dimethylsulphoniopropionate (DMSP), an osmolyte of algae and abundant carbon source for marine bacteria. In the DMSP cleavage pathway, acrylate is transformed into acryloyl‐CoA by propionate‐CoA ligase (SPO2934) and other unidentified acyl‐CoA ligases. Acryloyl‐CoA is then reduced to propionyl‐CoA by AcuI or SPO1914. Acryloyl‐CoA is also rapidly hydrated to 3‐hydroxypropionyl‐CoA by acryloyl‐CoA hydratase (SPO0147). A SPO1914 mutant was unable to grow on acrylate as the sole carbon source, supporting its role in this pathway. Similarly, growth on methylmercaptopropionate, the first intermediate of the DMSP demethylation pathway, was severely inhibited by a mutation in the gene encoding crotonyl‐CoA carboxylase/reductase, demonstrating that acetate produced by this pathway was metabolized by the ethylmalonyl‐CoA pathway. Amino acids and nucleosides from cells grown on 13C‐enriched DMSP possessed labelling patterns that were consistent with carbon from DMSP being metabolized by both the ethylmalonyl‐CoA and acrylate pathways as well as a role for pyruvate dehydrogenase. This latter conclusion was supported by the phenotype of a pdh mutant, which grew poorly on electron‐rich substrates. Additionally, label from [13C‐methyl] DMSP only appeared in carbons derived from methyl‐tetrahydrofolate, and there was no evidence for a serine cycle of C‐1 assimilation.
Vascular endothelial cells as targets for photochemical internalization (PCI)
Authors: Vikdal Marie , Weyergang Anette , Selbo Pål Kristian , Berg Kristian 
Published: July 2013

AbstractCancer treatment can be exerted by targeting both cancer cells and the vasculature supplying solid tumors. Photochemical internalization (PCI) is a modality for cytosolic drug delivery, but recent data on contrast‐enhanced MRI have indicated that the method also reduces blood perfusion in HT1080 fibrosarcoma xenografts. The present report aims to investigate if PCI may exert direct cytotoxic effects on endothelial cells. PCI of saporin was performed on endothelial human umbilical vein endothelial cell (HUVEC) and fibrosarcoma cells (HT1080) using two PCI‐relevant photosensitizers, TPPS2a and AlPcS2a. A 22‐ and 13‐fold higher photosensitizer uptake was detected in the endothelial cells compared with the HT1080 cells for AlPcS2a and TPPS2a, respectively. PCI of saporin was, however, found more effective in HT1080 cells. For HT1080 cells, PCI with saporin increased cell killing 1.9‐fold over photodynamic therapy alone, but under the same conditions, only increased HUVEC cell killing by 1.6‐ and 1.3‐fold with AlPcS2a and TPPS2a, respectively. Saporin uptake was higher in HUVECs than in the HT1080 cells, hence did not reflect the cell line differences in PCI efficacy. This is the first report on PCI‐mediated kill of endothelial cells and lays the foundation for further preclinical evaluation of the PCI technology as an antivascular strategy to ablate tumors.
Congenital plaque‐like glomangioma treated successfully with dual wavelength pulsed‐dye and neodymium:yttrium‐aluminum‐garnet laser
Authors: Grillo Emiliano , Boixeda Pablo , Paoli John , Vano‐Galván Sergio , Carrillo Rosario , Jaén Pedro 
Published: July 2013

SummaryGlomovenous malformations are disseminated variants of cutaneous glomus tumors. These malformations are subdivided into regional or localized, disseminated, and congenital plaque‐like forms. The congenital plaque‐like form is the rarest variant. Most treatment modalities have been disappointing in the treatment of large glomangiomas, leading to high recurrence rates. We report a case of a 34‐year‐old man with a congenital plaque‐like glomangioma on his left arm and forearm treated successfully with sequential pulsed‐dye neodymium yttrium aluminum garnet laser.
Second‐degree burn within a tattoo after intense‐pulsed‐light epilation
Authors: Riml Stefan , Larcher Lorenz , Grohmann Martin , Kompatscher Peter 
Published: July 2013

SummaryThe use of high energy light sources [laser, intense pulsed light (IPL)] is booming in aesthetic surgery. A trend, especially concerning usage of photoepilation in cosmetic institutes, is detectable. Photoepilation works through selective photothermolysis, by heating the chromophore melanin within the hair follicles. We present a case impressionably demonstrating that high‐energy light demands profound knowledge of its mechanism of action, and can cause severe harm in absence of basic knowledge. Photoepilation is a balancing act between maximal therapeutic effect and minimal side effect risk. Nevertheless, complications have to be clearly distinguished from professional errors. The latter are rising especially with IPL devices, mainly because its use depicts a legal grey area in most of the countries and is not bound to physicians' supervision. Due to its worse risk–benefit profile as compared with that of laser therapy, we advise against the use of IPL devices and claim for stricter regulation of its use, similar to laser devices.
Professional killer cell deficiencies and decreased survival in pulmonary arterial hypertension
Authors: Edwards Adrienne L , Gunningham Sarah P , Clare Geoffrey C , Hayman Matthew W , Smith Mark , Frampton Christopher MA , Robinson Bridget A , Troughton Richard W , Beckert Lutz EL 
Published: July 2013

AbstractBackground and objectiveIncreasing evidence implicates lymphocytes in pulmonary arterial hypertension (PAH) pathogenesis. Rats deficient in T‐lymphocytes show increased propensity to develop PAH but when injected with endothelial progenitor cells are protected from PAH (a mechanism dependent on natural killer (NK) cells). A decreased quantity of circulating cytotoxic CD8+ T‐lymphocytes and NK cells are now reported in PAH patients; however, the effect of lymphocyte depletion on disease outcome is unknown.MethodsThis prospective study analysed the lymphocyte profile and plasma brain natriuretic peptide (BNP) levels of patients with idiopathic PAH (IPAH), connective tissue disease‐associated PAH (CTD‐APAH) and matched healthy controls. Lymphocyte surface markers studied include: CD4+ (helper T‐cell marker), CD8+ (cytotoxic T‐cell marker), CD56/CD16 (NK cell marker) and CD19+ (mature B‐cell marker). Lymphocyte deficiencies and plasma BNP levels were then correlated with clinical outcome.ResultsFourteen patients with PAH (9 IPAH, 5CTD) were recruited. Three patients were deceased at 1‐year follow‐up; all had elevated CD4 : CD8 ratios and deficiencies of NK cells and cytotoxic CD8+ T‐lymphocytes at recruitment. Patients with normal lymphocyte profiles at recruitment were all alive a year later, and none were on the active transplant list. As univariate markers, cytotoxic CD8+ T‐cell and NK cell counts were linked to short‐term survival.ConclusionsDeficiencies in NK cells and cytotoxic CD8+ T‐cells may be associated with an increased risk of death in PAH patients. Further research is required in larger numbers of patients and to elucidate the mechanism of these findings.
Oil Spill Causation and the Deepwater Horizon Spill
Authors: Kurtz Rick S. 
Published: July 2013

AbstractTheApril 20, 2010,BPDeepwater Horizon blowout riveted citizen and elected officials' attention on coastal oil spills in ways not seen since the ill‐fated 1989ExxonValdezcrisis. A commonly voiced lament included why was the tragedy not prevented? Why the seemingly poor safety practices and who is to blame? Could a spill of such catastrophic proportion happen elsewhere in the future? Applying a spill prevention causation framework developed through the examination of other major near‐shore incidents over a 23‐year period, the author finds Deepwater Horizon exhibited a pattern of shortcomings evident in these other spills. These shortcomings are rooted in policy imperfections, a weak regulatory regime, organizational deviance in lieu of integrity, and interorganizational structure deficiencies.
How Large‐Scale Research Facilities Connect to Global Research
Authors: Lauto Giancarlo , Valentin Finn 
Published: July 2013

AbstractPolicies for large‐scale research facilities (LSRFs) often highlight their spillovers to industrial innovation and their contribution to the external connectivity of the regional innovation system hosting them. Arguably, the particular institutional features of LSRFs are conducive for collaborative research. However, based on data on publications produced in 2006–2009 at the Neutron Science Directorate of Oak Ridge National Laboratory in Tennessee (United States), we find that internationalization of its collaborative research is restrained by coordination costs similar to those characterizing other institutional settings. Policies mandating LSRFs should consider that research prioritized on the basis of technological relevance limits the international reach of collaborations. Additionally, the propensity for international collaboration is lower for resident scientists than for those affiliated with domestic universities or government laboratories. Policies conceiving LSRFs as “knowledge attractors” therefore should consider the complementarities between research at a LSRF and in its academic context at a regional or national level.
Effects of pepper crop residues and inorganic fertilizers on soil properties relevant to carbon cycling and broccoli production
Authors: Moreno‐Cornejo J. , Zornoza R. , Faz A. , Rosales R. M. 
Published: July 2013

AbstractWe conducted a two‐year experiment to evaluate the effects of fresh pepper residues (CRtreatment) on soil properties and broccoli yield compared with the application of chemical fertilizers (CFtreatment). Soil‐state13Cnuclear magnetic resonance (13C NMR) spectroscopy was used to characterize the organic composition of added residues and surface soil. We also measured total and soluble organic carbon and different biochemical properties associated with theCcycle. The results show that large application rates ofCRincreased microbial biomass carbon (MBC) and arylesterase and β‐glucosidase activities compared with the control. There was a significant increase inMBCfor theCFtreatment only with the greatest application rate. No differences in soil organic carbon composition and structure were found between treatments with soil organicC, solubleC, basal soil respiration, arylesterase and β‐glucosidase activities correlated positively with the soil carboxylic region and negatively with the aromatic region of the spectra. Broccoli yield was significantly more for the second crop cycle with maximum values for the greatest application rates ofCFandCRindicating that crop residues with a minimum amount of chemical fertilizers can be used to obtain an adequate yield. The use of pepper residues as an organic amendment improved biochemical properties of the soil with positive effects on broccoli quality and had no negative impact on yield.
Cyclooxygenase‐2, prostaglandin E2 glycerol ester and nitric oxide are involved in muscarine‐induced presynaptic enhancement at the vertebrate neuromuscular junction
Authors: Lindgren Clark A. , Newman Zachary L. , Morford Jamie J. , Ryan Steven B. , Battani Kathryn A. , Su Zheng 
Published: July 2013

Key points
The synapse between a nerve and muscle, called the neuromuscular junction (NMJ), undergoes a biphasic modulation, a decrease followed by an increase, when muscarinic acetylcholine receptors are continuously activated.
The initial depression is caused by the endocannabinoid 2‐arachidonylglycerol (2‐AG), which is synthesized in and released from the muscle; 2‐AG then activates cannabinoid receptors on the presynaptic nerve.
In the work presented here, we explored the mechanism responsible for the delayed enhancement, uncovering a role for the enzyme cyclooxygenase‐2 and locating it in the glial cells at the NMJ called perisynaptic Schwann cells (PSCs) where it converts 2‐AG into the glycerol ester of prostaglandin E2.
These results reveal a complex mechanism for regulating neurotransmitter release that involves the nerve, muscle and PSCs (i.e. the tripartite synapse) and may serve to ensure reliable neuromuscular transmission during periods of intense or long‐term activity.
Abstract  Previous work has demonstrated that activation of muscarinic acetylcholine receptors at the lizard neuromuscular junction (NMJ) induces a biphasic modulation of evoked neurotransmitter release: an initial depression followed by a delayed enhancement. The depression is mediated by the release of the endocannabinoid 2‐arachidonylglycerol (2‐AG) from the muscle and its binding to cannabinoid type 1 receptors on the motor nerve terminal. The work presented here suggests that the delayed enhancement of neurotransmitter release is mediated by cyclooxygenase‐2 (COX‐2) as it converts 2‐AG to the glycerol ester of prostaglandin E2 (PGE2‐G). Using immunofluorescence, COX‐2 was detected in the perisynaptic Schwann cells (PSCs) surrounding the NMJ. Pretreatment with either of the selective COX‐2 inhibitors, nimesulide or DuP 697, prevents the delayed increase in endplate potential (EPP) amplitude normally produced by muscarine. In keeping with its putative role as a mediator of the delayed muscarinic effect, PGE2‐G enhances evoked neurotransmitter release. Specifically, PGE2‐G increases the amplitude of EPPs without altering that of spontaneous miniature EPPs. As shown previously for the muscarinic effect, the enhancement of evoked neurotransmitter release by PGE2‐G depends on nitric oxide (NO) as the response is abolished by application of either NG‐nitro‐l‐arginine methyl ester (l‐NAME), an inhibitor of NO synthesis, or carboxy‐PTIO, a chelator of NO. Intriguingly, the enhancement is not prevented by AH6809, a prostaglandin receptor antagonist, but is blocked by capsazepine, a TRPV1 and TRPM8 receptor antagonist. Taken together, these results suggest that the conversion of 2‐AG to PGE2‐G by COX‐2 underlies the muscarine‐induced enhancement of neurotransmitter release at the vertebrate NMJ.
Energy and Exergy Analyses of a New Triple-Staged Refrigeration Cycle Using Solar Heat Source
Authors: Khaliq Abdul , Kumar Rajesh , Dincer Ibrahim , Khalid Farrukh 
Published: July 2013

AbstractIn this paper, energy and exergy analyses of a new solar-driven triple-staged refrigeration cycle using Duratherm 600 oil as the heat transfer fluid are performed. The proposed cycle is an integration of absorption refrigeration cycle (ARC), ejector (EJE) refrigeration cycle (ERC), and ejector expansion Joule–Thomson (EJT) refrigeration cryogenic cycles which could produce refrigeration output of different magnitude at different temperature simultaneously. Both exergy destruction and losses in each component and hence in the overall system are determined to identify the causes and locations of the thermodynamic imperfection. Several design parameters, including the hot oil outlet temperature, refrigerant turbine inlet pressure, and the evaporator temperature of ERC and EJT cycle are also tested to evaluate their effects on energy and exergy performance. It is observed that largest contribution to cycle irreversibility comes from the central receiver and heliostat field with the heat recovery vapor generator (HRVG), condenser, and ejector of ERC itself also contributing considerably. The exergy efficiency of the solar-driven triple-staged refrigeration cycle is 4% which is much lower than its energy efficiency of 10%, respectively. The results clearly reveal that thermodynamic investigations based on energy analysis alone cannot legitimately be complete unless the exergy concept becomes a part of the analysis.
Role of 6-Gingerol in Reduction of Cholera Toxin Activity
In Vitro
and
In Vivo
Authors: Saha Pallashri , Das Bornita , Chaudhuri Keya 
Published: July 2013

ABSTRACT

Vibrio cholerae
is one of the major bacterial pathogens responsible for the devastating diarrheal disease called cholera. Chemotherapy is often used against
V. cholerae
infections; however, the emergence of
V. cholerae
with multidrug resistance (MDR) toward the chemotherapeutic agents is a serious clinical problem. This scenario has provided us with the impetus to look into herbal remediation, especially toward blocking the action of cholera toxin (CT). Our studies were undertaken to determine the antidiarrheal potential of 6-gingerol (6G) on the basis of its effect on CT, the virulence factor secreted by
V. cholerae
. We report here that 6G binds to CT, hindering its interaction with the GM1 receptor present on the intestinal epithelial cells. The 50% inhibitory concentration (IC
50
) was determined to be 10 μg/ml. The detailed mechanistic study was conducted by enzyme-linked immunosorbent assay (ELISA), fluorescence spectroscopy, and isoelectric focusing. These results were validated with
in vitro
studies performed with the CHO, HeLa, and HT-29 cell lines, whereas a rabbit ileal loop assay was done to estimate the
in vivo
action, which confirms the efficacy of 6G in remediation of the choleragenic effects of CT. Thus, 6G can be an effective adjunctive therapy with oral rehydration solution for severe CT-mediated diarrhea.