Publications by authors named "Johnston E"

Purpose: To compare the size of ablation zones derived from nonperfused ex vivo livers with ablation zones created using an ex vivo perfused porcine liver model.

Materials And Methods: Six fresh porcine livers were used to evaluate microwave ablation (MWA). Perfused (n = 3) and nonperfused (n = 3) livers were warmed to 37°C by oxygenated, O-positive human blood reconstituted with Ringer solution, using an organ perfusion circuit.

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The synthesis of two molecular iron complexes, a dinuclear iron(iii,iii) complex and a nonanuclear iron complex, based on the dinucleating ligand 2,2'-(2-hydroxy-5-methyl-1,3-phenylene)bis(1H-benzo[d]imidazole-4-carboxylic acid) is described. The two iron complexes were found to drive the oxidation of water by the one-electron oxidant [Ru(bpy)3](3+).

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Bone loss is a well-known medical consequence of disuse such as in long-term space flight. Immobilization in many animals mimics the effects of space flight on bone mineral density. Decreases in metabolism are also thought to contribute to a loss of skeletal mass.

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Objectives The study objective was to examine the prevalence of maternal multivitamin use and associations with preterm birth (<37 weeks gestation) in the United States. We additionally examined whether associations differed by race/ethnicity. Methods Using the Pregnancy Risk Assessment Monitoring System, we analyzed 2009-2010 data among women aged ≥18 years with a singleton live birth who completed questions on multivitamin use 1 month prior to pregnancy (24 states; n = 57,348) or in the last 3 months of pregnancy (3 states, n = 5095).

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How soil microbial communities contrast with respect to taxonomic and functional composition within and between ecosystems remains an unresolved question that is central to predicting how global anthropogenic change will affect soil functioning and services. In particular, it remains unclear how small-scale observations of soil communities based on the typical volume sampled (1-2 g) are generalizable to ecosystem-scale responses and processes. This is especially relevant for remote, northern latitude soils, which are challenging to sample and are also thought to be more vulnerable to climate change compared to temperate soils.

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Background: The strategy for preoperative management of biliary obstruction in hilar cholangiocarcinoma (HCCA) patients with regards to drainage by endoscopic (EBD) or percutaneous (PTBD) methods is not clearly defined. The aim of this study was to investigate the utility, complications and therapeutic efficacy of these methods in HCCA patients, with a secondary aim to assess the use of portal vein embolization (PVE) in patients undergoing drainage.

Methods: Studies incorporating HCCA patients undergoing biliary drainage prior to curative resection were included (EMBASE and Medline databases).

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The United States has experienced an unsustainable increase of the biomedical research workforce over the past 3 decades. This expansion has led to a myriad of consequences, including an imbalance in the number of researchers and available tenure-track faculty positions, extended postdoctoral training periods, increasing age of investigators at first U.S.

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A 69-year-old man who presented with abdominal discomfort was, on examination, found to have a palpable abdominal mass. Contrast-enhanced CT showed a mass arising from the inferior vena cava, which biopsy confirmed to be a leiomyosarcoma. One month after chemoradiotherapy, CT demonstrated a new 15 mm solitary central right liver metastasis.

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Background: As an alternative to hospital admission, crisis resolution teams (CRTs) provide intensive home treatment to people experiencing mental health crises. Trial evidence supports the effectiveness of the CRT model, but research suggests that the anticipated reductions in inpatient admissions and increased user satisfaction with acute care have been less than hoped for following the scaling up of CRTs nationally in England, as mandated by the National Health Service (NHS) Plan in 2000. The organisation and service delivery of the CRTs vary substantially.

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Offshore oil and gas activities can result in the discharge of large amounts of drilling muds. While these materials have generally been regarded as non-toxic to marine organisms, recent studies have demonstrated negative impacts to suspension feeding organisms. We exposed the arctic-boreal sponge Geodia barretti to the primary particulate components of two water-based drilling muds; barite and bentonite.

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Lytic polysaccharide monooxygenases (LPMOs) are copper-containing enzymes that oxidatively break down recalcitrant polysaccharides such as cellulose and chitin. Since their discovery, LPMOs have become integral factors in the industrial utilization of biomass, especially in the sustainable generation of cellulosic bioethanol. We report here a structural determination of an LPMO-oligosaccharide complex, yielding detailed insights into the mechanism of action of these enzymes.

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Soil microbial communities are essential for ecosystem function, but linking community composition to biogeochemical processes is challenging because of high microbial diversity and large spatial variability of most soil characteristics. We investigated soil bacterial community structure in a switchgrass stand planted on soil with a history of grassland vegetation at high spatial resolution to determine whether biogeographic trends occurred at the centimeter scale. Moreover, we tested whether such heterogeneity, if present, influenced community structure within or among ecosystems.

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Background: Infliximab and adalimumab have established roles in inflammatory bowel disease (IBD) therapy. UK regulators mandate reassessment after 12 months' anti-TNF therapy for IBD, with consideration of treatment withdrawal. There is a need for more data to establish the relapse rates following treatment cessation.

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Although iron- and sulfate-reducing bacteria in subsurface environments have crucial roles in biogeochemical cycling of C, Fe, and S, how specific electron donors impact the compositional structure and activity of native iron- and/or sulfate-reducing communities is largely unknown. To understand this better, we created bicarbonate-buffered batch systems in duplicate with three different electron donors (acetate, lactate, or glucose) paired with ferrihydrite and sulfate as the electron acceptors and inoculated them with subsurface sediment as the microbial inoculum. Sulfate and ferrihydrite reduction occurred simultaneously and were faster with lactate than with acetate.

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Background: Adolescent girls involved with the juvenile justice system have higher rates of sexually transmitted infections and pregnancy than their nondetained peers. Although they may receive reproductive health care while detained, following clinician recommendations and accessing services in the community can be challenging.

Objectives: This study aimed to determine the barriers this population faces 1) accessing reproductive health care and 2)following the recommendations they receive when they are in the community.

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Biofilms are integral to many marine processes but their formation and function may be affected by anthropogenic inputs that alter environmental conditions, including fertilisers that increase nutrients. Density composition and connectivity of biofilms developed in situ (under ambient and elevated nutrients) were compared using 454-pyrosequencing of the 16S gene. Elevated nutrients shifted community composition from bacteria involved in higher processes (eg Pseudoalteromonas spp.

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Study Design Randomized controlled trial. Objective The aim of this study was to assess the efficacy of the bone grafting substitute silicate-substituted calcium phosphate (SiCaP) compared with recombinant human bone morphogenetic protein 2 (rhBMP-2) and to evaluate the clinical outcomes over a period of 2 years. Methods Patients undergoing PLF surgery for DDD at a single center were recruited and randomized to one of two groups: SiCaP (n = 9) or rhBMP-2 (n = 10).

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Alcohol oxidases, including carbohydrate oxidases, have a long history of research that has generated fundamental biological understanding and biotechnological applications. Despite a long history of study, the galactose 6-oxidase/glyoxal oxidase family of mononuclear copper-radical oxidases, Auxiliary Activity Family 5 (AA5), is currently represented by only very few characterized members. Here we report the recombinant production and detailed structure-function analyses of two homologues from the phytopathogenic fungi Colletotrichum graminicola and C.

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Global seascapes are increasingly modified to support high levels of human activity in the coastal zone. Modifications include the addition of defense structures and boating infrastructure, such as seawalls and marinas that replace natural habitats. Artificial structures support different macrofaunal communities to those found on natural rocky shores; however, little is known about differences in microbial community structure or function in urban seascapes.

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Understanding interactive effects of contaminants is critical to predict how human activities change ecosystem structure and function. We examined independent and interactive effects of two contaminants (fertiliser and copper paint) on the recruitment, mortality, and total abundance of developing invertebrate communities in the field, 2, 4, 6, and 8 weeks after substrate submersion. Contaminants affected community structure differently, and produced an intermediate community in combination.

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Budd-Chiari syndrome is a rare disorder characterised by hepatic venous outflow obstruction. It affects 1.4 per million people, and presentation depends upon the extent and rapidity of hepatic vein occlusion.

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The derivation of second-generation biofuels from non-edible biomass is viewed as crucial for establishing a sustainable bio-based economy for the future. The inertness of lignocellulosic biomass makes its breakdown for conversion into fuels and other compounds a challenge. Enzyme cocktails can be utilized in the bio-refinery for lignocellulose deconstruction but until recently their costs were regarded as high.

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Many genes that affect replicative lifespan (RLS) in the budding yeast Saccharomyces cerevisiae also affect aging in other organisms such as C. elegans and M. musculus.

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Spectroscopic and computational methods have been used to determine the protonation state of the edge sulfur ligand in the CuS Cu form of the active site of nitrous oxide reductase (NOR) in its 3CuCu (1-hole) and 2Cu2Cu (2-hole) redox states. The EPR, absorption, and MCD spectra of 1-hole Cu indicate that the unpaired spin in this site is evenly delocalized over Cu, Cu, and Cu. 1-hole Cu is shown to have a μ-thiolate edge ligand from the observation of S-H bending modes in the resonance Raman spectrum at 450 and 492 cm that have significant deuterium isotope shifts (-137 cm) and are not perturbed up to pH 10.

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