453 research outputs found
Alternating Copolymers Incorporating Dithienogemolodithiophene for Field-Effect Transistor Applications
We report the synthesis of an electron-rich
fused dithienogemolodithiophene
monomer containing straight chain tetradecyl solubilizing groups.
Copolymers were prepared with four different electron accepting monomers
of varying reduction potential. We report how the choice of acceptor
influences the optical properties and molecular energy levels as well
as the solid state packing. Field effect transistor devices were fabricated
using silver source-drain electrodes, with a promising charge carrier
mobility up to 0.26 cm<sup>2</sup> V<sup>−1</sup> s<sup>−1</sup> for films deposited
from non-chlorinated solvents. These results suggest dithienogemolodithiophene
is a useful building block for the development of high performance
semiconducting polymers
Domesticating the ‘troubled family’: Racialised sexuality and the postcolonial governance of family life in the UK
This article examines how the UK’s Troubled Families Programme (TFP) works as a strategy of domestication which produces and delimits certain forms of ‘family life’. Drawing upon critical geographies of home and empire, the article explores how the TFP works to manage the troubled family as part of a longer history of regulating unruly households in the name of national health and civilisation. Viewing the TFP as part of the production of heteronormative order, highlights how the policy remobilises and reconfigures older forms of colonial rule which work to demarcate between civility/savagery, the developable/undevelopable. In examining the postcolonial dimension of neoliberal social policy, the article stresses how the TFP relies on racializing and sexualised logics of socio-biological control borrowed from imperial eugenics. Reading the TFP in this way contributes to our understanding of neoliberal rule. That the troubled family can be either domesticated or destroyed (through benefit sanctions and eviction) equally reveals the extent to which domesticity works as a key site for the production of both ‘worthy’ and ‘surplus’ life
Uncovering treatment burden as a key concept for stroke care: a systematic review of qualitative research
<b>Background</b> Patients with chronic disease may experience complicated management plans requiring significant personal investment. This has been termed ‘treatment burden’ and has been associated with unfavourable outcomes. The aim of this systematic review is to examine the qualitative literature on treatment burden in stroke from the patient perspective.<p></p>
<b>Methods and findings</b> The search strategy centred on: stroke, treatment burden, patient experience, and qualitative methods. We searched: Scopus, CINAHL, Embase, Medline, and PsycINFO. We tracked references, footnotes, and citations. Restrictions included: English language, date of publication January 2000 until February 2013. Two reviewers independently carried out the following: paper screening, data extraction, and data analysis. Data were analysed using framework synthesis, as informed by Normalization Process Theory. Sixty-nine papers were included. Treatment burden includes: (1) making sense of stroke management and planning care, (2) interacting with others, (3) enacting management strategies, and (4) reflecting on management. Health care is fragmented, with poor communication between patient and health care providers. Patients report inadequate information provision. Inpatient care is unsatisfactory, with a perceived lack of empathy from professionals and a shortage of stimulating activities on the ward. Discharge services are poorly coordinated, and accessing health and social care in the community is difficult. The study has potential limitations because it was restricted to studies published in English only and data from low-income countries were scarce.<p></p>
<b>Conclusions</b> Stroke management is extremely demanding for patients, and treatment burden is influenced by micro and macro organisation of health services. Knowledge deficits mean patients are ill equipped to organise their care and develop coping strategies, making adherence less likely. There is a need to transform the approach to care provision so that services are configured to prioritise patient needs rather than those of health care systems
Measurement of the top quark mass using the matrix element technique in dilepton final states
We present a measurement of the top quark mass in pp¯ collisions at a center-of-mass energy of 1.96 TeV at the Fermilab Tevatron collider. The data were collected by the D0 experiment corresponding to an integrated luminosity of 9.7 fb−1. The matrix element technique is applied to tt¯ events in the final state containing leptons (electrons or muons) with high transverse momenta and at least two jets. The calibration of the jet energy scale determined in the lepton+jets final state of tt¯ decays is applied to jet energies. This correction provides a substantial reduction in systematic uncertainties. We obtain a top quark mass of mt=173.93±1.84 GeV
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Divergent evolution of the activity and regulation of the glutamate decarboxylase systems in Listeria monocytogenes EGD-e and 10403S : roles in virulence and acid tolerance
The glutamate decarboxylase (GAD) system has been shown to be important for the survival of Listeria monocytogenes in low pH environments. The bacterium can use this faculty to maintain pH homeostasis under acidic conditions. The accepted model for the GAD system proposes that the antiport of glutamate into the bacterial cell in exchange for γ-aminobutyric acid (GABA) is coupled to an intracellular decarboxylation reaction of glutamate into GABA that consumes protons and therefore facilitates pH homeostasis. Most strains of L. monocytogenes possess three decarboxylase genes (gadD1, D2 & D3) and two antiporter genes (gadT1 & gadT2). Here, we confirm that the gadD3 encodes a glutamate decarboxylase dedicated to the intracellular GAD system (GADi), which produces GABA from cytoplasmic glutamate in the absence of antiport activity. We also compare the functionality of the GAD system between two commonly studied reference strains, EGD-e and 10403S with differences in terms of acid resistance. Through functional genomics we show that EGD-e is unable to export GABA and relies exclusively in the GADi system, which is driven primarily by GadD3 in this strain. In contrast 10403S relies upon GadD2 to maintain both an intracellular and extracellular GAD system (GADi/GADe). Through experiments with a murinised variant of EGD-e (EGDm) in mice, we found that the GAD system plays a significant role in the overall virulence of this strain. Double mutants lacking either gadD1D3 or gadD2D3 of the GAD system displayed reduced acid tolerance and were significantly affected in their ability to cause infection following oral inoculation. Since EGDm exploits GADi but not GADe the results indicate that the GADi system makes a contribution to virulence within the mouse. Furthermore, we also provide evidence that there might be a separate line of evolution in the GAD system between two commonly used reference strains
Hyperpolarized 13C-Pyruvate Metabolism as a Surrogate for Tumor Grade and Poor Outcome in Renal Cell Carcinoma-A Proof of Principle Study.
Differentiating aggressive clear cell renal cell carcinoma (ccRCC) from indolent lesions is challenging using conventional imaging. This work prospectively compared the metabolic imaging phenotype of renal tumors using carbon-13 MRI following injection of hyperpolarized [1-13C]pyruvate (HP-13C-MRI) and validated these findings with histopathology. Nine patients with treatment-naïve renal tumors (6 ccRCCs, 1 liposarcoma, 1 pheochromocytoma, 1 oncocytoma) underwent pre-operative HP-13C-MRI and conventional proton (1H) MRI. Multi-regional tissue samples were collected using patient-specific 3D-printed tumor molds for spatial registration between imaging and molecular analysis. The apparent exchange rate constant (kPL) between 13C-pyruvate and 13C-lactate was calculated. Immunohistochemistry for the pyruvate transporter (MCT1) from 44 multi-regional samples, as well as associations between MCT1 expression and outcome in the TCGA-KIRC dataset, were investigated. Increasing kPL in ccRCC was correlated with increasing overall tumor grade (ρ = 0.92, p = 0.009) and MCT1 expression (r = 0.89, p = 0.016), with similar results acquired from the multi-regional analysis. Conventional 1H-MRI parameters did not discriminate tumor grades. The correlation between MCT1 and ccRCC grade was confirmed within a TCGA dataset (p < 0.001), where MCT1 expression was a predictor of overall and disease-free survival. In conclusion, metabolic imaging using HP-13C-MRI differentiates tumor aggressiveness in ccRCC and correlates with the expression of MCT1, a predictor of survival. HP-13C-MRI may non-invasively characterize metabolic phenotypes within renal cancer
Enhanced Monocyte Response and Decreased Central Memory T Cells in Children with Invasive Staphylococcus aureus Infections
Staphylococcus aureus has emerged as a significant pathogen causing severe invasive disease in otherwise healthy people. Despite considerable advances in understanding the epidemiology, resistance mechanisms, and virulence factors produced by the bacteria, there is limited knowledge of the in vivo host immune response to acute, invasive S. aureus infections. Herein, we report that peripheral blood mononuclear cells from patients with severe S. aureus infections demonstrate a distinctive and robust gene expression profile which is validated in a distinct group of patients and on a different microarray platform. Application of a systems-wide modular analysis framework reveals significant over-expression of innate immunity genes and under-expression of genes related to adaptive immunity. Simultaneous flow cytometry analyses demonstrated marked alterations in immune cell numbers, with decreased central memory CD4 and CD8 T cells and increased numbers of monocytes. CD14+ monocyte numbers significantly correlated with the gene expression levels of genes related to the innate immune response. These results demonstrate the value of applying a systems biology approach that reveals the significant alterations in the components of circulating blood lymphocytes and monocytes in invasive S. aureus infections
Adoption of practice guidelines and assessment tools in substance abuse treatment
<p>Abstract</p> <p>Background</p> <p>The gap between research and practice limits utilization of relevant, progressive and empirically validated strategies in substance abuse treatment.</p> <p>Methods</p> <p>Participants included substance abuse treatment programs from the Northeastern United States. Structural equation models were constructed with agency level data to explore two outcome variables: adoption of practice guidelines and assessment tools at two points in time; models also included organizational, staffing and service variables.</p> <p>Results</p> <p>In 1997, managed care involvement and provision of primary care services had the strongest association with increased use of assessment tools, which, along with provision of counseling services, were associated with a greater use of practice guidelines. In 2001, managed care involvement, counseling services and being a stand-alone drug treatment agency were associated with a greater use of assessment tools, which was in turn related to an increase in the use of practice guidelines.</p> <p>Conclusions</p> <p>This study provides managers, clinicians and policy-makers with a framework for understanding factors related to the adoption of new technologies in substance abuse treatment.</p
A Dual Receptor Crosstalk Model of G-Protein-Coupled Signal Transduction
Macrophage cells that are stimulated by two different ligands that bind to G-protein-coupled receptors (GPCRs) usually respond as if the stimulus effects are additive, but for a minority of ligand combinations the response is synergistic. The G-protein-coupled receptor system integrates signaling cues from the environment to actuate cell morphology, gene expression, ion homeostasis, and other physiological states. We analyze the effects of the two signaling molecules complement factors 5a (C5a) and uridine diphosphate (UDP) on the intracellular second messenger calcium to elucidate the principles that govern the processing of multiple signals by GPCRs. We have developed a formal hypothesis, in the form of a kinetic model, for the mechanism of action of this GPCR signal transduction system using data obtained from RAW264.7 macrophage cells. Bayesian statistical methods are employed to represent uncertainty in both data and model parameters and formally tie the model to experimental data. When the model is also used as a tool in the design of experiments, it predicts a synergistic region in the calcium peak height dose response that results when cells are simultaneously stimulated by C5a and UDP. An analysis of the model reveals a potential mechanism for crosstalk between the Gαi-coupled C5a receptor and the Gαq-coupled UDP receptor signaling systems that results in synergistic calcium release
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