1,400 research outputs found
Excessive anticoagulation identified by emergency medical service through point-of-care coagulometry
Bleeding because of excessive anticoagulation is a well-recognized complication of coumadin therapy. In cases of potentially life-threatening bleeding such as intracranial haemorrhage, reversal of anticoagulation should be carried out as soon as possible. Here we report the case of an emergency patient in whom excessive anticoagulation was diagnosed at the scene by emergency medical service personnel through the use of a point-of-care coagulometer. Following hospital admission, findings were confirmed by central laboratory assessment of prothrombin time. The time gained through the use of portable coagulometers may contribute to improved pre-hospital emergency management of anticoagulated patients
Program of large high perveance ionizer studies
Large porous tungsten sources of cesium ions - ionizer performance at high current densities and relation of performance to physical propertie
Post-exercise hypotension time-course is influenced by exercise intensity: a randomised trial comparing moderate-intensity, high-intensity, and sprint exercise
Reductions in blood pressure (BP) induced by exercise training may be associated with the acute reduction in BP observed minutes to hours following an exercise session, termed post-exercise hypotension (PEH). However, the magnitude and time-course of PEH, including the optimal exercise characteristics to maximise it, are still unclear. Using a randomised crossover design, 16 normotensive participants (median age (range) 22 (19–31) years; 50% female) undertook three different exercise sessions: sprint interval exercise (SIE, 30 × 8-s sprints with 32 s recovery), high-intensity interval exercise (HIIE, 15 × 1-min intervals at 90% peak heart rate (HR) with 1-min recovery), and moderate-intensity continuous exercise (MICE, 48 min at 65% peak HR). BP and HR were monitored before and up to 90 min following each session. The three exercise sessions each showed distinct PEH and of similar overall magnitude up to 90 min post exercise; however, there were distinct differences in the time-course. Systolic BP was lower 40 min after MICE compared to HIIE (−7.7 (−13.9 to −2.4) mmHg) and diastolic BP was higher 5 min after HIIE compared to SIE (8.5 (2.3–14.7) mmHg). MICE induced lower HR up to 40 min after exercise compared to HIIE and SIE. HIIE and SIE induced PEH of similar magnitude to MICE. A phasic or ‘W-shaped’ time-course of PEH observed following HIIE and SIE contrasted to a distinct ‘V-shaped’ PEH following MICE, indicating the physiological mechanisms driving BP regulation after exercise are influenced by exercise intensity
Conserved noncoding sequences highlight shared components of regulatory networks in dicotyledonous plants
Conserved noncoding sequences (CNSs) in DNA are reliable pointers to regulatory elements controlling gene expression. Using a comparative genomics approach with four dicotyledonous plant species (Arabidopsis thaliana, papaya [Carica papaya], poplar [Populus trichocarpa], and grape [Vitis vinifera]), we detected hundreds of CNSs upstream of Arabidopsis genes. Distinct positioning, length, and enrichment for transcription factor binding sites suggest these CNSs play a functional role in transcriptional regulation. The enrichment of transcription factors within the set of genes associated with CNS is consistent with the hypothesis that together they form part of a conserved transcriptional network whose function is to regulate other transcription factors and control development. We identified a set of promoters where regulatory mechanisms are likely to be shared between the model organism Arabidopsis and other dicots, providing areas of focus for further research
Molecular heterogeneity in major urinary proteins of Mus musculus subspecies: potential candidates involved in speciation
When hybridisation carries a cost, natural selection is predicted to favour evolution of traits that allow assortative mating (reinforcement). Incipient speciation between the two European house mouse subspecies, Mus musculus domesticus and M.m.musculus, sharing a hybrid zone, provides an opportunity to understand evolution of assortative mating at a molecular level. Mouse urine odours allow subspecific mate discrimination, with assortative preferences evident in the hybrid zone but not in allopatry. Here we assess the potential of MUPs (major urinary proteins) as candidates for signal divergence by comparing MUP expression in urine samples from the Danish hybrid zone border (contact) and from allopatric populations. Mass spectrometric characterisation identified novel MUPs in both subspecies involving mostly new combinations of amino acid changes previously observed in M.m.domesticus. The subspecies expressed distinct MUP signatures, with most MUPs expressed by only one subspecies. Expression of at least eight MUPs showed significant subspecies divergence both in allopatry and contact zone. Another seven MUPs showed divergence in expression between the subspecies only in the contact zone, consistent with divergence by reinforcement. These proteins are candidates for the semiochemical barrier to hybridisation, providing an opportunity to characterise the nature and evolution of a putative species recognition signal
Effectiveness of interventions to increase hepatitis C testing uptake among high-risk groups: a systematic review
Background: People who inject drugs are at the greatest risk of acquiring hepatitis C virus infection in many high-income countries, including those in Europe. Our review examined the effectiveness of interventions aimed at increasing hepatitis C virus testing uptake. Methods: We undertook a systematic review of controlled studies. Searches of 13 databases were supplemented with citation searching, and manual searches of reference lists and websites. Studies of interventions that aimed to increase testing uptake among high-risk groups were included. Testing uptake was our primary outcome measure of interest and secondary outcomes were engagement in follow-up services and treatment. A narrative synthesis was undertaken. Results: Eight controlled studies were included. Three studies examined interventions in primary care; one examined dried blood spot testing as an alternative method of testing, and two examined outreach provision. Two further studies examined interventions to improve hepatitis C management. Targeted case finding in primary care, support and training for primary care practitioners, offering alternative testing and provision of outreach testing all increased uptake of testing; however, intervention effects were variable. Conclusions: Evidence from the available studies suggests that increases in testing uptake can be achieved. Careful attention needs to be paid to the resource implications associated with implementation of interventions in primary care settings and also of the potential for interventions to improve outcomes once a positive diagnosis has been made. Further research on the cost-effectiveness of the intervention approaches examined in this review is required
Electron-hole asymmetry in two-terminal graphene devices
A theoretical model is proposed to describe asymmetric gate-voltage
dependence of conductance and noise in two-terminal ballistic graphene devices.
The model is analyzed independently within the self-consistent Hartree and
Thomas-Fermi approximations. Our results justify the prominent role of metal
contacts in recent experiments with suspended graphene flakes. The
contact-induced electrostatic potentials in graphene demonstrate a power-law
decay with the exponent varying from -1 to -0.5. Within our model we explain
electron-hole asymmetry and strong Fabri-Perot oscillations of the conductance
and noise at positive doping, which were observed in many experiments with
submicrometer samples. Limitations of the Thomas-Fermi approximation in a
vicinity of the Dirac point are discussed.Comment: 7 pages, 8 figure
Characterisation of urinary WFDC12 in small nocturnal basal primates, mouse lemurs (Microcebus spp.)
Mouse lemurs are basal primates that rely on chemo- and acoustic signalling for social interactions in their dispersed social systems. We examined the urinary protein content of two mouse lemurs species, within and outside the breeding season, to assess candidates used in species discrimination, reproductive or competitive communication. Urine from Microcebus murinus and Microcebus lehilahytsara contain a predominant 10 kDa protein, expressed in both species by some, but not all, males during the breeding season, but at very low levels by females. Mass spectrometry of the intact proteins confirmed the protein mass and revealed a 30 Da mass difference between proteins from the two species. Tandem mass spectrometry after digestion with three proteases and sequencing de novo defined the complete protein sequence and located an Ala/Thr difference between the two species that explained the 30 Da mass difference. The protein (mature form: 87 amino acids) is an atypical member of the whey acidic protein family (WFDC12). Seasonal excretion of this protein, species difference and male-specific expression during the breeding season suggest that it may have a function in intra- and/or intersexual chemical signalling in the context of reproduction, and could be a cue for sexual selection and species recognition
Poisson-de Rham homology of hypertoric varieties and nilpotent cones
We prove a conjecture of Etingof and the second author for hypertoric
varieties, that the Poisson-de Rham homology of a unimodular hypertoric cone is
isomorphic to the de Rham cohomology of its hypertoric resolution. More
generally, we prove that this conjecture holds for an arbitrary conical variety
admitting a symplectic resolution if and only if it holds in degree zero for
all normal slices to symplectic leaves.
The Poisson-de Rham homology of a Poisson cone inherits a second grading. In
the hypertoric case, we compute the resulting 2-variable Poisson-de
Rham-Poincare polynomial, and prove that it is equal to a specialization of an
enrichment of the Tutte polynomial of a matroid that was introduced by Denham.
We also compute this polynomial for S3-varieties of type A in terms of Kostka
polynomials, modulo a previous conjecture of the first author, and we give a
conjectural answer for nilpotent cones in arbitrary type, which we prove in
rank less than or equal to 2.Comment: 25 page
Direct characterization of the native structure and mechanics of cyanobacterial carboxysomes
Carboxysomes are proteinaceous organelles that play essential roles in enhancing carbon fixation in cyanobacteria and some proteobacteria. These self-assembling organelles encapsulate Ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) and carbonic anhydrase using a protein shell structurally resembling an icosahedral viral capsid. The protein shell serves as a physical barrier to protect enzymes from the cytosol and a selectively permeable membrane to mediate transport of enzyme substrates and products. The structural and mechanical nature of native carboxysomes remain unclear. Here, we isolate functional β-carboxysomes from the cyanobacterium Synechococcus elongatus PCC7942 and perform the first characterization of the macromolecular architecture and inherent physical mechanics of single β-carboxysomes using electron microscopy, atomic force microscopy (AFM) and proteomics. Our results illustrate that the intact β-carboxysome comprises three structural domains, a single-layered icosahedral shell, an inner layer and paracrystalline arrays of interior Rubisco. We also observe the protein organization of the shell and partial β-carboxysomes that likely serve as the β-carboxysome assembly intermediates. Furthermore, the topography and intrinsic mechanics of functional β-carboxysomes are determined in native conditions using AFM and AFM-based nanoindentation, revealing the flexible organization and soft mechanical properties of β-carboxysomes compared to rigid viruses. Our study provides new insights into the natural characteristics of β-carboxysome organization and nanomechanics, which can be extended to diverse bacterial microcompartments and are important considerations for the design and engineering of functional carboxysomes in other organisms to supercharge photosynthesis. It offers an approach for inspecting the structural and mechanical features of synthetic metabolic organelles and protein scaffolds in bioengineering
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