1,459 research outputs found

    A Terminal Velocity on the Landscape: Particle Production near Extra Species Loci in Higher Dimensions

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    We investigate particle production near extra species loci (ESL) in a higher dimensional field space and derive a speed limit in moduli space at weak coupling. This terminal velocity is set by the characteristic ESL-separation and the coupling of the extra degrees of freedom to the moduli, but it is independent of the moduli's potential if the dimensionality of the field space is considerably larger than the dimensionality of the loci, D >> d. Once the terminal velocity is approached, particles are produced at a plethora of nearby ESLs, preventing a further increase in speed via their backreaction. It is possible to drive inflation at the terminal velocity, providing a generalization of trapped inflation with attractive features: we find that more than sixty e-folds of inflation for sub-Planckian excursions in field space are possible if ESLs are ubiquitous, without fine tuning of initial conditions and less tuned potentials. We construct a simple, observationally viable model with a slightly red scalar power-spectrum and suppressed gravitational waves; we comment on the presence of additional observational signatures originating from IR-cascading and individual massive particles. We also show that moduli-trapping at an ESL is suppressed for D >> d, hindering dynamical selection of high-symmetry vacua on the landscape based on this mechanism.Comment: 46 pages, 6 figures. V3: typos corrected compared to JHEP version, conclusions unchange

    The importance of both setting and intensity of physical activity in relation to non-clinical anxiety and depression

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    Physical activity is associated with good physical and mental health. Current recommendations suggest that people should achieve 30 minutes of moderate-intensity activity most days of the week to gain health benefits. This activity may be accumulated in leisure time, in active commuting, at work or in the home. Here we look at the cross-sectional relationship between physical activity and mental health as measured by the HADS anxiety and depression scores in a sample of 1,742 participants from a Scottish general population survey. The participants were men and women in three age cohorts aged around 24, 44 and 64 years who, in 1995, were interviewed face to face and also self-completed the HADS depression and anxiety scale. Respondents reported their levels of physical activity at work, in the home and in leisure time; the intensities of activity were also determined. Physical activity was related to depression scores but not to anxiety scores. There was no relationship between work physical activity and depression score. Among women, depression score increased with each additional episode of vigorous home activity. In both sexes, depression score decreased with each additional episode of vigorous leisure activity, but among men the decrease in depression score with moderate leisure activity was reversed if a lot of moderate activity was undertaken. We have found a variable relationship between depression scores and various settings for physical activity. Researchers, policymakers and practitioners who are interested in the relationship between physical activity and mental health should take into account the setting for activity as well as frequency, duration and intensity of activity

    Direct exfoliation and dispersion of two-dimensional materials in pure water via temperature control

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    The high-volume synthesis of two-dimensional (2D) materials in the form of platelets is desirable for various applications. While water is considered an ideal dispersion medium, due to its abundance and low cost, the hydrophobicity of platelet surfaces has prohibited its widespread use. Here we exfoliate 2D materials directly in pure water without using any chemicals or surfactants. In order to exfoliate and disperse the materials in water, we elevate the temperature of the sonication bath, and introduce energy via the dissipation of sonic waves. Storage stability greater than one month is achieved through the maintenance of high temperatures, and through atomic and molecular level simulations, we further discover that good solubility in water is maintained due to the presence of platelet surface charges as a result of edge functionalization or intrinsic polarity. Finally, we demonstrate inkjet printing on hard and flexible substrates as a potential application of water-dispersed 2D materials.close1

    Effects of patient selection on the applicability of results from a randomised clinical trial (EORTC 10853) investigating breast-conserving therapy for DCIS

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    Selection of patients for randomised clinical trials may have a large impact on the applicability of the study results to the general population presenting the same disorder. However, clinical characteristics and outcome data on non-entered patients are usually not available. The effects of patient selection for the EORTC 10853 trial investigating the role of radiotherapy in breast conserving therapy for ductal carcinoma in situ have been studied, in an analysis of all patients treated for ductal carcinoma in situ in five participating institutes. The reasons for not entering patients were evaluated and treatment results of the randomised patients were compared to those not entered. A total of 910 patients were treated for ductal carcinoma in situ. Of these, 477 (52%) were ineligible, with the size of the lesion being the main reason for ineligibility (30% of all ductal carcinoma in situ). Of the 433 eligible patients, 278 (64%) were randomised into the trial. The main reasons for non-entry of eligible patients were either physicians' preference for one of the treatment arms (26%) or patients' refusal (9%). These percentages showed significant variation among the institutes. At 4 years follow-up, those patients not entered in the trial and treated with local excision and radiotherapy, had higher local recurrence rates than the patients randomised in the trial and treated with the same approach, (17 vs 2%, P=0.03). The patients treated with local excision alone had equal local recurrence rates (11% in both groups). Selection of patients may explain the differences in outcome of the randomised patients, and those not-entered. Thus, the results of this trial may not be applicable to all patients with ductal carcinoma in situ

    A novel PCR-based method for high throughput prokaryotic expression of antimicrobial peptide genes

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    <p>Abstract</p> <p>Background</p> <p>To facilitate the screening of large quantities of new antimicrobial peptides (AMPs), we describe a cost-effective method for high throughput prokaryotic expression of AMPs. EDDIE, an autoproteolytic mutant of the N-terminal autoprotease, Npro, from classical swine fever virus, was selected as a fusion protein partner. The expression system was used for high-level expression of six antimicrobial peptides with different sizes: Bombinin-like peptide 7, Temporin G, hexapeptide, Combi-1, human Histatin 9, and human Histatin 6. These expressed AMPs were purified and evaluated for antimicrobial activity.</p> <p>Results</p> <p>Two or four primers were used to synthesize each AMP gene in a single step PCR. Each synthetic gene was then cloned into the pET30a/His-EDDIE-GFP vector via an <it>in vivo </it>recombination strategy. Each AMP was then expressed as an Npro fusion protein in <it>Escherichia coli</it>. The expressed fusion proteins existed as inclusion bodies in the cytoplasm and the expression levels of the six AMPs reached up to 40% of the total cell protein content. On <it>in vitro </it>refolding, the fusion AMPs was released from the C-terminal end of the autoprotease by self-cleavage, leaving AMPs with an authentic N terminus. The released fusion partner was easily purified by Ni-NTA chromatography. All recombinant AMPs displayed expected antimicrobial activity against <it>E. coli</it>, <it>Micrococcus </it>luteus and <it>S. cerevisia</it>.</p> <p>Conclusions</p> <p>The method described in this report allows the fast synthesis of genes that are optimized for over-expression in <it>E. coli </it>and for the production of sufficiently large amounts of peptides for functional and structural characterization. The Npro partner system, without the need for chemical or enzymatic removal of the fusion tag, is a low-cost, efficient way of producing AMPs for characterization. The cloning method, combined with bioinformatic analyses from genome and EST sequence data, will also be useful for screening new AMPs. Plasmid pET30a/His-EDDIE-GFP also provides green/white colony selection for high-throughput recombinant AMP cloning.</p

    Dental management considerations for the patient with an acquired coagulopathy. Part 1: Coagulopathies from systemic disease

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    Current teaching suggests that many patients are at risk for prolonged bleeding during and following invasive dental procedures, due to an acquired coagulopathy from systemic disease and/or from medications. However, treatment standards for these patients often are the result of long-standing dogma with little or no scientific basis. The medical history is critical for the identification of patients potentially at risk for prolonged bleeding from dental treatment. Some time-honoured laboratory tests have little or no use in community dental practice. Loss of functioning hepatic, renal, or bone marrow tissue predisposes to acquired coagulopathies through different mechanisms, but the relationship to oral haemostasis is poorly understood. Given the lack of established, science-based standards, proper dental management requires an understanding of certain principles of pathophysiology for these medical conditions and a few standard laboratory tests. Making changes in anticoagulant drug regimens are often unwarranted and/or expensive, and can put patients at far greater risk for morbidity and mortality than the unlikely outcome of postoperative bleeding. It should be recognised that prolonged bleeding is a rare event following invasive dental procedures, and therefore the vast majority of patients with suspected acquired coagulopathies are best managed in the community practice setting

    Understanding and meeting the needs of those using growth hormone injection devices

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    BACKGROUND: Recombinant human growth hormone (r-hGH) is used to treat: growth hormone deficiency in children and adults; children born small for gestational age; Turner's syndrome; and chronic renal failure. r-hGH is administered by daily subcutaneous injection and may be given using a number of different administration devices. The aim of this survey was, firstly, to identify which attributes of an r-hGH administration device are considered most important to physicians, teenage patients, parents of young children requiring GH and nurses who have experience of r-hGH administration, and, secondly, to determine how they rate existing devices in each of these key attributes. METHODS: The opinions of 67 individuals with experience in r-hGH administration were captured in discussion sessions. Parents, physicians and nurses were asked to rate 19 device attributes by completing a questionnaire, and to rank four different r-hGH administration devices (including a conceptual electronic device) in order of preference. RESULTS: Reliability, ease of use, lack of pain during injection, safety in use, storage, and number of steps in preparation before use, during use and after were considered to be the five most desirable attributes of an r-hGH administration device. An electronic device was preferred to an automatic, multi-dose injection device, a needle-free injection device or a manual, ready-to-use, disposable injection device. CONCLUSION: In the opinion of physicians, nurses and parents using r-hGH injection devices, an ideal device must combine reliability with simplicity, while delivering treatment with minimal pain. An electronic device, which combines many of the most useful features of existing devices with novel functions, was the preferred option for r-hGH administration

    Acute paranoid psychosis as sole clinical presentation of hepatic artery thrombosis after living donor liver transplantation

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    <p>Abstract</p> <p>Background</p> <p>Hepatic artery thrombosis is a devastating complication after orthotopic liver transplantation often requiring revascularization or re-transplantation. It is associated with considerably increased morbidity and mortality. Acute cognitive dysfunction such as delirium or acute psychosis may occur after major surgery and may be associated with the advent of surgical complications.</p> <p>Case presentation</p> <p>Here we describe a case of hepatic artery thrombosis after living-donor liver transplantation which was not preceded by signs of liver failure but rather by an episode of acute psychosis. After re-transplantation the patient recovered without sequelae.</p> <p>Conclusion</p> <p>This case highlights the need to remain cautious when psychiatric disorders occur in patients after liver transplantation. The diagnostic procedures should not be restricted to medical or neurological causes of psychosis alone but should also focus vascular complications related to orthotopic liver transplantation.</p

    A randomized, controlled, prospective trial to evaluate the haemostatic effect of Lyostypt versus Surgicel in arterial bypass anastomosis: "COBBANA" trial

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    <p>Abstract</p> <p>Background</p> <p>The development of suture hole bleeding at peripheral arterial bypass anastomoses using PTFE graft prostheses is a common problem in peripheral vascular surgery. Traditionally the problem is managed by compression with surgical swabs and reversal heparin or by using several haemostatic device (e.g. different forms of collagen, oxidized cellulose, gelatine sponge, ethylcyanoacrylate glue or fibrin) with various success. Preclinical data suggest that the haemostatic effect of collagen is stronger than that of oxidized cellulose, but no direct clinical comparison of their hemostatic performance has been published so far.</p> <p>Design</p> <p>This randomized, controlled, prospective trial evaluates the haemostatic effect of Lyostypt versus Surgicel in arterial bypass anastomosis. 28 patients undergoing an elective peripheral vascular reconstruction due to peripheral vascular disease will be included. Suture hole bleeding occurring at the arterial bypass anastomosis using a PTFE prostheses will be stopped by the application of Lyostypt and/or Surgicel. The proximal anastomoses will be randomized intraoperatively. The patients will be allocated into 4 different treatment groups. Group1 Lyostypt distal/Surgicel proximal; Group 2: Lyostypt proximal/Surgicel distal; Group 3: Surgicel distal and proximal; Group 4: Lyostypt distal and proximal. Primary endpoint of the study is time to haemostasis. Secondary endpoints are the number of intraoperatively used haemostatic devices, postoperative mortality within 30 days as well as the intraoperative efficacy rating of the two devices evaluated by the surgeon. As a safety secondary parameter, the local and general complication occurring till 30 ± 10 days postoperatively will also be analysed. After hospital discharge the investigator will examine the enrolled patients again at 30 days after surgery.</p> <p>Discussion</p> <p>The COBBANA trial aims to assess, whether the haemostatic effect of Lyostypt is superior to Surgicel in suture hole bleedings of arterial bypass anastomoses.</p> <p>Trial registration</p> <p>NCT00837954</p
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