1,422 research outputs found
Recombinant canine single chain insulin analogues: Insulin receptor binding capacity and ability to stimulate glucose uptake
Virtually all diabetic dogs require exogenous insulin therapy to control their hyperglycaemia. In the UK, the only licensed insulin product currently available is a purified porcine insulin preparation. Recombinant insulin is somewhat problematic in terms of its manufacture, since the gene product (preproinsulin) undergoes substantial post-translational modification in pancreatic β cells before it becomes biologically active. The aim of the present study was to develop recombinant canine single chain insulin (SCI) analogues that could be produced in a prokaryotic expression system and which would require minimal processing. Three recombinant SCI constructs were developed in a prokaryotic expression vector, by replacing the insulin C-peptide sequence with one encoding a synthetic peptide (GGGPGKR), or with one of two insulin-like growth factor (IGF)-2 C-peptide coding sequences (human: SRVSRRSR; canine: SRVTRRSSR). Recombinant proteins were expressed in the periplasmic fraction of Escherichia coli and assessed for their ability to bind to the insulin and IGF-1 receptors, and to stimulate glucose uptake in 3T3-L1 adipocytes.
All three recombinant SCI analogues demonstrated preferential binding to the insulin receptor compared to the IGF-1 receptor, with increased binding compared to recombinant canine proinsulin. The recombinant SCI analogues stimulated glucose uptake in 3T3-L1 adipocytes compared to negligible uptake using recombinant canine proinsulin, with the canine insulin/cIGF-2 chimaeric SCI analogue demonstrating the greatest effect. Thus, biologically-active recombinant canine SCI analogues can be produced relatively easily in bacteria, which could potentially be used for treatment of diabetic dogs
The phosphoproteome of Arabidopsis plants lacking the oxidative signal-inducible1 (OXI1) protein kinase
The AGC protein kinase OXI1 is a key protein in plant responses to oxidative signals, and is important for two oxidative burst-mediated processes: basal resistance to microbial pathogens and root hair growth. To identify possible components of the OXI1 signalling pathway, phosphoproteomic techniques were used to detect alterations in the abundance of phosphorylated proteins and peptides in an oxi1 null mutant of Arabidopsis thaliana. The relative abundance of phosphorylated proteins was assessed either using two-dimensional gel electrophoresis and staining with the phosphoprotein stain Pro-Q Diamond or by the identification and quantification, by mass spectrometry, of stable-isotope labelled phosphopeptides. A number of proteins show altered phosphorylation in the oxi1 mutant. Five proteins, including a putative F-box and 3-phosphoinositide-dependent kinase 1, show reduced phosphorylation in the oxi1 mutant, and may be direct or indirect targets of OXI1. Four proteins, including ethylene insensitive 2 and phospholipase d-gamma, show increased phosphorylation in the oxi1 mutant. This study has identified a range of candidate proteins from the OXI1 signalling pathway. The diverse activities of these proteins, including protein degradation and hormone signalling, may suggest crosstalk between OXI1 and other signal transduction cascades.</p
Evaluating 3D-printed bioseparation structures using multi-length scale tomography
X-ray computed tomography was applied in imaging 3D-printed gyroids used for bioseparation in order to visualize and characterize structures from the entire geometry down to individual nanopores. Methacrylate prints were fabricated with feature sizes of 500 µm, 300 µm, and 200 µm, with the material phase exhibiting a porous substructure in all cases. Two X-ray scanners achieved pixel sizes from 5 µm to 16 nm to produce digital representations of samples across multiple length scales as the basis for geometric analysis and flow simulation. At the gyroid scale, imaged samples were visually compared to the original computed-aided designs to analyze printing fidelity across all feature sizes. An individual 500 µm feature, part of the overall gyroid structure, was compared and overlaid between design and imaged volumes, identifying individual printed layers. Internal subvolumes of all feature sizes were segmented into material and void phases for permeable flow analysis. Small pieces of 3D-printed material were optimized for nanotomographic imaging at a pixel size of 63 nm, with all three gyroid samples exhibiting similar geometric characteristics when measured. An average porosity of 45% was obtained that was within the expected design range, and a tortuosity factor of 2.52 was measured. Applying a voidage network map enabled the size, location, and connectivity of pores to be identified, obtaining an average pore size of 793 nm. Using Avizo XLAB at a bulk diffusivity of 7.00 × 10⁻¹¹ m2s⁻¹ resulted in a simulated material diffusivity of 2.17 × 10⁻¹¹ m²s⁻¹ ± 0.16 × 10⁻¹¹ m2s⁻¹
Imaging the Renner-Teller effect using laser-induced electron diffraction
Structural information on electronically excited neutral molecules can be
indirectly retrieved, largely through pump-probe and rotational spectroscopy
measurements with the aid of calculations. Here, we demonstrate the direct
structural retrieval of neutral carbonyl disulfide (CS) in the BB
excited electronic state using laser-induced electron diffraction (LIED). We
unambiguously identify the ultrafast symmetric stretching and bending of the
field-dressed neutral CS molecule with combined picometer and attosecond
resolution using intrapulse pump-probe excitation and measurement. We invoke
the Renner-Teller effect to populate the BB excited state in neutral
CS, leading to bending and stretching of the molecule. Our results
demonstrate the sensitivity of LIED in retrieving the geometric structure of
CS, which is known to appear as a two-center scatterer
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Rillenkarren at Vayia: geomorphology and a new class of Early Bronze Age fortified settlement in Southern Greece
With ever more inhibited programmes of excavation, new methods of site survey are always
welcome. Here a soil geomorphologist joins forces with archaeologists to read the history of
limestone blocks exposed on the surface at sites in southern Greece. Rillenkarren for example are
vertical grooves caused by rainfall on stones that remained for long periods in the same place.
These and other observations showed that what looked like clearance cairns had in fact been piled
up in the Early Bronze Age and led in turn to the definition of a new type of settlementKeywords: fortifications, stone cairns, karst geomorphology, Greece, Early Bronze AgeKeywords: fortifications, stone cairns, karst geomorphology, Greece, Early Bronze Ag
A Church-based Diabetes Self-management Education Program for African Americans With Type 2 Diabetes
INTRODUCTION: Diabetes self-management education interventions in community gathering places have been moderately effective, but very few studies of intervention effectiveness have been conducted among African Americans with type 2 diabetes. This paper describes a church-based diabetes self-management education intervention for African Americans, a randomized controlled trial to evaluate the intervention, and baseline characteristics of study participants. METHODS: A New DAWN: Diabetes Awareness & Wellness Network was conducted among 24 churches of varying size in North Carolina. Each church recruited congregants with type 2 diabetes and designated a diabetes advisor, or peer counselor, to be part of the intervention team. Participants were enrolled at each church and randomized as a unit to either the special intervention or the minimal intervention. The special intervention included one individual counseling visit, twelve group sessions, three postcard messages from the participant's diabetes care provider, and twelve monthly telephone calls from a diabetes advisor. Baseline data included measures of weight, hemoglobin A1c, blood pressure, physical activity, dietary and diabetes self-care practices, and psychosocial factors. The study to evaluate the intervention (from enrollment visit to last follow-up) began in February 2001 and ended in August 2003. RESULTS: Twenty-four churches (with 201 total participants) were randomized. Sixty-four percent of the participants were women. On average, the participants were aged 59 years and sedentary. They had an average of 12 years of education, had been diagnosed with diabetes for 9 years, had a body mass index of 35, had a hemoglobin A1c level of 7.8%, and had a reported dietary intake of 39% of calories from fat. CONCLUSION: A New DAWN is a culturally sensitive, church-based diabetes self-management education program for African Americans with type 2 diabetes that is being evaluated for effectiveness in a randomized controlled trial. The outcomes of A New DAWN will contribute to the literature on community-based interventions for minority populations and help to inform the selection of approaches to improve diabetes care in this population
Evidence for an ηc(1S)π−resonance in B0→ηc(1S)K+π−decays
A Dalitz plot analysis of B0→ηc(1S)K+π− decays is performed using data samples of pp collisions collected with the LHCb detector at centre-of-mass energies of s√=7, 8 and 13TeV, corresponding to a total integrated luminosity of 4.7 fb −1. A satisfactory description of the data is obtained when including a contribution representing an exotic ηc(1S)π− resonant state. The significance of this exotic resonance is more than three standard deviations, while its mass and width are 4096±20 +18−22MeV and 152±58 +60−35MeV, respectively. The spin-parity assignments JP=0+ and JP=1− are both consistent with the data. In addition, the first measurement of the B0→ηc(1S)K+π− branching fraction is performed and gives B(B0→ηc(1S)K+π−)=(5.73±0.24±0.13±0.66)×10−4, where the first uncertainty is statistical, the second systematic, and the third is due to limited knowledge of external branching fractions
Study of prompt D 0 meson production in pPb collisions at √sNN=5 TeV
Production of prompt D 0 mesons is studied in proton-lead and lead-proton collisions recorded at the LHCb detector at the LHC. The data sample corresponds to an integrated luminosity of 1.58±0.02 nb −1 recorded at a nucleon-nucleon centre-of-mass energy of sNN=5 TeV. Measurements of the differential cross-section, the forward-backward production ratio and the nuclear modification factor are reported using D 0 candidates with transverse momenta less than 10 GeV/c and rapidities in the ranges 1.5 < y ∗ < 4.0 and −5.0 < y ∗ < −2.5 in the nucleon-nucleon centre-of-mass system
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