1,896 research outputs found

    Probing temperature- and solvent-dependent protein dynamics using terahertz time-domain spectroscopy

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    The effect of temperature on the terahertz-frequency-range material properties of lyophilized and single-crystal hen egg-white lysozyme has been measured using terahertz time-domain spectroscopy, with the results presented and discussed in the context of protein and solvent dynamical and glass transitions. Lyophilized hen egg-white lysozyme was measured over a temperature range from 4 to 290 K, and a change in the dynamical behaviour of the sample at around 100 K was observed through a change in the terahertz absorption spectrum. Additionally, the effect of cryoprotectants on the temperature-dependent absorption coefficient is studied, and it is demonstrated that terahertz time-domain spectroscopy is capable of resolving the true glass transition temperature of single-crystal hen egg-white lysozyme at 150 K, which is in agreement with literature values measured using differential scanning calorimetry

    Chlamydiosis in British Garden Birds (2005–2011): Retrospective Diagnosis and Chlamydia psittaci Genotype Determination

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    The significance of chlamydiosis as a cause of mortality in wild passerines (Order Passeriformes), and the role of these birds as a potential source of zoonotic Chlamydia psittaci infection, is unknown. We reviewed wild bird mortality incidents (2005–2011). Where species composition or post-mortem findings were indicative of chlamydiosis, we examined archived tissues for C. psittaci infection using PCR and ArrayTube Microarray assays. Twenty-one of 40 birds tested positive: 8 dunnocks (Prunella modularis), 7 great tits (Parus major), 3 blue tits (Cyanistes caeruleus), 2 collared doves (Streptopelia decaocto, Order Columbiformes), and 1 robin (Erithacus rubecula). Chlamydia psittaci genotype A was identified in all positive passerines and in a further three dunnocks and three robins diagnosed with chlamydiosis from a previous study. Two collared doves had genotype E. Ten of the 21 C. psittaci-positive birds identified in the current study had histological lesions consistent with chlamydiosis and co-localizing Chlamydia spp. antigens on immunohistochemistry. Our results indicate that chlamydiosis may be a more common disease of British passerines than was previously recognized. Wild passerines may be a source of C. psittaci zoonotic infection, and people should be advised to take appropriate hygiene precautions when handling bird feeders or wild birds

    Drowning is an apparent and unexpected recurrent cause of mass mortality of Common starlings (Sturnus vulgaris)

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    Drowning is infrequently reported as a cause of death of wild birds and such incidents typically involve individual, rather than multiple, birds. Over a 21-year period (1993 to 2013 inclusive), we investigated 12 incidents of mortality of multiple (2-80+) Common starlings (Sturnus vulgaris) in Great Britain that appeared to be due to drowning. More than ten birds were affected in ten of these reported incidents. These incidents always occurred during the spring and early summer months and usually involved juvenile birds. In all cases, circumstantial evidence and post-mortem examinations indicated drowning to be the most likely cause of death with no underlying disease found. A behavioural explanation seems likely, possibly related to the gregarious nature of this species combined with juvenile inexperience in identifying water hazards. A review of data from the ringed bird recovery scheme across Great Britain (1913-2013 inclusive) of both starlings and Common blackbirds (Turdus merula), also a common garden visitor, identified additional suspected drowning incidents, which were significantly more common in the former species, supporting a species predisposition to drowning. For each species there was a marked seasonal peak from April to August. Drowning should be included as a differential diagnosis when investigating incidents of multiple starling mortality, especially of juveniles

    FDG‐PET/CT after two cycles of R‐CHOP in DLBCL predicts complete remission but has limited value in identifying patients with poor outcome – final result of a UK National Cancer Research Institute prospective study

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    The UK National Cancer Research Institute initiated a prospective study (UKCRN‐ID 1760) to assess the prognostic value of early fluorodeoxyglucose (FDG)‐positron emission tomography (PET)/computed tomography (CT) in diffuse large B‐cell lymphoma (DLBCL). In total, 189 patients with DLBCL treated with R‐CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone) had baseline and post‐cycle‐2 PET (PET2) within a quality assurance framework. Treatment decisions were based on CT; PET2 was archived for central blinded reporting after treatment completion. The association of PET2 response with end‐of‐treatment CT, progression‐free (PFS) and overall survival (OS) was explored. The end‐of‐treatment complete response rate on CT was 83·9%, 75·0%, 70·5%, 40·4% and 36·4% for Deauville score (DS) 1 (n = 34), 2 (n = 39), 3 (n = 46), 4 (n = 56) and 5 (n = 14) (P < 0·001); and 64·1% and 50·0% for the maximum standardised uptake value (∆SUVmax) of ≥66% (n = 168) and <66% (n = 21), respectively (P = 0·25). After a median 5·4 years of follow‐up, the 5‐year PFS was 69·4%, 72·8%, 76·7%, 71·2% and 47·6% by DS 1–5 (P = 0·01); and 72·6% and 57·1% by ∆SUVmax of ≥66% and <66% (P = 0·03), respectively. The association with DS remained in multivariable analyses, and was consistent for OS. Early complete metabolic response (DS 1–3) at interim PET/CT after two cycles of R‐CHOP in DLBCL was associated with a higher end‐of‐treatment complete and overall response rate; however, only DS‐5 patients had inferior PFS and OS

    Performance of bulk SiC radiation detectors

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    SiC is a wide-gap material with excellent electrical and physical properties that may make it an important material for some future electronic devices. The most important possible applications of SiC are in hostile environments, such as in car/jet engines, within nuclear reactors, or in outer space. Another area where the material properties, most notably radiation hardness, would be valuable is in the inner tracking detectors of particle physics experiments. Here, we describe the performance of SiC diodes irradiated in the 24 GeV proton beam at CERN. Schottky measurements have been used to probe the irradiated material for changes in I–V characteristics. Other methods, borrowed from III–V research, used to study the irradiated surface include atomic force microscope scans and Raman spectroscopy. These have been used to observe the damage to the materials surface and internal lattice structure. We have also characterised the detection capabilities of bulk semi-insulating SiC for α radiation. By measuring the charge collection efficiency (CCE) for variations in bias voltage, CCE values up to 100% have been measured

    Melaena with Peutz-Jeghers syndrome: a case report

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    Introduction: Peutz-Jeghers syndrome (PJS) is a rare familial disorder characterised by mucocutaneous pigmentation, gastrointestinal and extragastrointestinal hamartomatous polyps and an increased risk of malignancy. Peutz-Jeghers polyps in the bowel may result in intussusception. This complication usually manifests with abdominal pain and signs of intestinal obstruction. Case Presentation: We report the case of a 24-year-old Caucasian male who presented with melaena. Pigmentation of the buccal mucosa was noted but he was pain-free and examination of the abdomen was unremarkable. Upper gastrointestinal endoscopy revealed multiple polyps. An urgent abdominal computed tomography (CT) scan revealed multiple small bowel intussusceptions. Laparotomy was undertaken on our patient, reducing the intussusceptions and removing the polyps by enterotomies. Bowel resection was not needed. Conclusion: Melaena in PJS needs to be urgently investigated through a CT scan even in the absence of abdominal pain and when clinical examination of the abdomen shows normal findings. Although rare, the underlying cause could be intussusception, which if missed could result in grave consequences

    Randomized controlled trial of mailed Nicotine Replacement Therapy to Canadian smokers: study protocol

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    <p>Abstract</p> <p>Background</p> <p>Considerable public health efforts are ongoing Canada-wide to reduce the prevalence of smoking in the general population. From 1985 to 2005, smoking rates among adults decreased from 35% to 19%, however, since that time, the prevalence has plateaued at around 18-19%. To continue to reduce the number of smokers at the population level, one option has been to translate interventions that have demonstrated clinical efficacy into population level initiatives. Nicotine Replacement Therapy (NRT) has a considerable clinical research base demonstrating its efficacy and safety and thus public health initiatives in Canada and other countries are distributing NRT widely through the mail. However, one important question remains unanswered - do smoking cessation programs that involve mailed distribution of free NRT work? To answer this question, a randomized controlled trial is required.</p> <p>Methods/Design</p> <p>A single blinded, panel survey design with random assignment to an experimental and a control condition will be used in this study. A two-stage recruitment process will be employed, in the context of a general population survey with two follow-ups (8 weeks and 6 months). Random digit dialing of Canadian home telephone numbers will identify households with adult smokers (aged 18+ years) who are willing to take part in a smoking study that involves three interviews, with saliva collection for 3-HC/cotinine ratio measurement at baseline and saliva cotinine verification at 8-week and 6-month follow-ups (N = 3,000). Eligible subjects interested in free NRT will be determined at baseline (N = 1,000) and subsequently randomized into experimental and control conditions to receive versus not receive nicotine patches. The primary hypothesis is that subjects who receive nicotine patches will display significantly higher quit rates (as assessed by 30 day point prevalence of abstinence from tobacco) at 6-month follow-up as compared to subjects who do not receive nicotine patches at baseline.</p> <p>Discussion</p> <p>The findings from the proposed trial are timely and highly relevant as mailed distribution of NRT require considerable resources and there are limited public health dollars available to combat this substantial health concern. In addition, findings from this randomized controlled trial will inform the development of models to engage smokers to quit, incorporating proactive recruitment and the offer of evidence based treatment.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov: <a href="http://www.clinicaltrials.gov/ct2/show/NCT01429129">NCT01429129</a></p

    A roadmap to advance delirium research: recommendations from the NIDUS Scientific Think Tank

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    Delirium is an acute disorder of attention and cognition. It occurs across the life span, yet it is particularly common among older adults, and is closely linked with underlying neurocognitive disorders. Evidence is mounting that intervening on delirium may represent an important opportunity for delaying the onset or progression of dementia. To accelerate the current understanding of delirium, the Network for Investigation of Delirium: Unifying Scientists (NIDUS) held a conference “Advancing Delirium Research: A Scientific Think Tank” in June 2019. This White Paper encompasses the major knowledge and research gaps identified at the conference: advancing delirium definition and measurement, understanding delirium pathophysiology, and prevention and treatment of delirium. A roadmap of research priorities is proposed to advance the field in a systematic, interdisciplinary, and coordinated fashion. A call is made for an international consortium and biobank targeted to delirium, as well as a public health campaign to advance the field.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/155509/1/alz12076_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/155509/2/alz12076.pd
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