23 research outputs found
Preparation and reactions of polymers and copolymers of 2-methylbut-1-en-3-one, and related studies.
Poly(2-methylbut-1-en-3-one) was prepared by bulk polymerisation with azobisisobutyronitrile as initiator. Six copolymers of 2-methylbut-l-en-3-one and styrene in various ratios were prepared similarly. The homopolymer on treatment in solution with hydrogen chloride gave a product in which water had been condensed from neighbouring acetyl side-chains to give a polymer containing series of conjugated double bonds. The homopolymer was oxidised with aqueous alkaline potassium permanganate to give a copolymer of methacrylic acid and 3-niethylbut-3-en-2-oxo-1-oic acid. The homopolymer was reduced with lithium aluminium hydride in tetrahydrofuran to give a product containing 70% of secondary alcohol groups. The homopolymer was treated with hydroxylamine hydrochloride in pyridine to give a product containing oxime groups, oxime anhydride groups and unreacted ketone groups. The 1:2-copolymer was brominated to give a product in which all the methyl ketone side-chains had been converted to bromomethyl ketone side-chains. The brominated 1:2-copolymer was reacted with thiourea to give a copolymer in which all the bromine had been replaced by isothiourea groups. Where possible low molecular weight analogues of the polymers were prepared, based on 2,2-dimethylbutan-3-one. The infra-red spectra of the polymers and polymeric derivatives were compared with those of the low molecular weight analogues. The reactivities of the above polymeric compounds are discussed in relation to the characteristics of the corresponding molecular models
Introduction: Shakespeare's public spheres
Habermasâ sense of a âcultural Public Sphereâ is a notoriously complex term and, when applied to Early Modern cultures, needs careful definition. This essay both introduces the variety of methods by which we might approach playtexts with a view to their public â auditory â impact and contributes to a debate about an audience's understanding of Shakespeare's plays. By selecting two words and their spread of use in one play, Twelfth Night, we might appreciate the potential for meaningful ambiguity latent in how we hear the language of live performance. If we search for how certain terms (in this case, the cluster of semes derived from repetitions of âfancyâ and âplayâ), we might find at times incompatible senses, yet we get near to appreciating the range of Early Modern dramatic language
Variation in Structure and Process of Care in Traumatic Brain Injury: Provider Profiles of European Neurotrauma Centers Participating in the CENTER-TBI Study.
INTRODUCTION: The strength of evidence underpinning care and treatment recommendations in traumatic brain injury (TBI) is low. Comparative effectiveness research (CER) has been proposed as a framework to provide evidence for optimal care for TBI patients. The first step in CER is to map the existing variation. The aim of current study is to quantify variation in general structural and process characteristics among centers participating in the Collaborative European NeuroTrauma Effectiveness Research in Traumatic Brain Injury (CENTER-TBI) study. METHODS: We designed a set of 11 provider profiling questionnaires with 321 questions about various aspects of TBI care, chosen based on literature and expert opinion. After pilot testing, questionnaires were disseminated to 71 centers from 20 countries participating in the CENTER-TBI study. Reliability of questionnaires was estimated by calculating a concordance rate among 5% duplicate questions. RESULTS: All 71 centers completed the questionnaires. Median concordance rate among duplicate questions was 0.85. The majority of centers were academic hospitals (n = 65, 92%), designated as a level I trauma center (n = 48, 68%) and situated in an urban location (n = 70, 99%). The availability of facilities for neuro-trauma care varied across centers; e.g. 40 (57%) had a dedicated neuro-intensive care unit (ICU), 36 (51%) had an in-hospital rehabilitation unit and the organization of the ICU was closed in 64% (n = 45) of the centers. In addition, we found wide variation in processes of care, such as the ICU admission policy and intracranial pressure monitoring policy among centers. CONCLUSION: Even among high-volume, specialized neurotrauma centers there is substantial variation in structures and processes of TBI care. This variation provides an opportunity to study effectiveness of specific aspects of TBI care and to identify best practices with CER approaches
BHPR research: qualitative1.âComplex reasoning determines patients' perception of outcome following foot surgery in rheumatoid arhtritis
Background: Foot surgery is common in patients with RA but research into surgical outcomes is limited and conceptually flawed as current outcome measures lack face validity: to date no one has asked patients what is important to them. This study aimed to determine which factors are important to patients when evaluating the success of foot surgery in RA Methods: Semi structured interviews of RA patients who had undergone foot surgery were conducted and transcribed verbatim. Thematic analysis of interviews was conducted to explore issues that were important to patients. Results: 11 RA patients (9 â, mean age 59, dis dur = 22yrs, mean of 3 yrs post op) with mixed experiences of foot surgery were interviewed. Patients interpreted outcome in respect to a multitude of factors, frequently positive change in one aspect contrasted with negative opinions about another. Overall, four major themes emerged. Function: Functional ability & participation in valued activities were very important to patients. Walking ability was a key concern but patients interpreted levels of activity in light of other aspects of their disease, reflecting on change in functional ability more than overall level. Positive feelings of improved mobility were often moderated by negative self perception ("I mean, I still walk like a waddling duckâ). Appearance: Appearance was important to almost all patients but perhaps the most complex theme of all. Physical appearance, foot shape, and footwear were closely interlinked, yet patients saw these as distinct separate concepts. Patients need to legitimize these feelings was clear and they frequently entered into a defensive repertoire ("it's not cosmetic surgery; it's something that's more important than that, you know?â). Clinician opinion: Surgeons' post operative evaluation of the procedure was very influential. The impact of this appraisal continued to affect patients' lasting impression irrespective of how the outcome compared to their initial goals ("when he'd done it ... he said that hasn't worked as good as he'd wanted to ... but the pain has goneâ). Pain: Whilst pain was important to almost all patients, it appeared to be less important than the other themes. Pain was predominately raised when it influenced other themes, such as function; many still felt the need to legitimize their foot pain in order for health professionals to take it seriously ("in the end I went to my GP because it had happened a few times and I went to an orthopaedic surgeon who was quite dismissive of it, it was like what are you complaining aboutâ). Conclusions: Patients interpret the outcome of foot surgery using a multitude of interrelated factors, particularly functional ability, appearance and surgeons' appraisal of the procedure. While pain was often noted, this appeared less important than other factors in the overall outcome of the surgery. Future research into foot surgery should incorporate the complexity of how patients determine their outcome Disclosure statement: All authors have declared no conflicts of interes
International genome-wide meta-analysis identifies new primary biliary cirrhosis risk loci and targetable pathogenic pathways.
Primary biliary cirrhosis (PBC) is a classical autoimmune liver disease for which effective immunomodulatory therapy is lacking. Here we perform meta-analyses of discovery data sets from genome-wide association studies of European subjects (n=2,764 cases and 10,475 controls) followed by validation genotyping in an independent cohort (n=3,716 cases and 4,261 controls). We discover and validate six previously unknown risk loci for PBC (Pcombined<5 Ă 10(-8)) and used pathway analysis to identify JAK-STAT/IL12/IL27 signalling and cytokine-cytokine pathways, for which relevant therapies exist
Finishing the euchromatic sequence of the human genome
The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers âŒ99% of the euchromatic genome and is accurate to an error rate of âŒ1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead
Variation in general supportive and preventive intensive care management of traumatic brain injury: a survey in 66 neurotrauma centers participating in the Collaborative European NeuroTrauma Effectiveness Research in Traumatic Brain Injury (CENTER-TBI) study
Abstract
Background
General supportive and preventive measures in the intensive care management of traumatic brain injury (TBI) aim to prevent or limit secondary brain injury and optimize recovery. The aim of this survey was to assess and quantify variation in perceptions on intensive care unit (ICU) management of patients with TBI in European neurotrauma centers.
Methods
We performed a survey as part of the Collaborative European NeuroTrauma Effectiveness Research in Traumatic Brain Injury (CENTER-TBI) study. We analyzed 23 questions focused on: 1) circulatory and respiratory management; 2) fever control; 3) use of corticosteroids; 4) nutrition and glucose management; and 5) seizure prophylaxis and treatment.
Results
The survey was completed predominantly by intensivists (nâ=â33, 50%) and neurosurgeons (nâ=â23, 35%) from 66 centers (97% response rate).
The most common cerebral perfusion pressure (CPP) target was >â60 mmHg (nâ=â39, 60%) and/or an individualized target (nâ=â25, 38%). To support CPP, crystalloid fluid loading (nâ=â60, 91%) was generally preferred over albumin (nâ=â15, 23%), and vasopressors (nâ=â63, 96%) over inotropes (nâ=â29, 44%). The most commonly reported target of partial pressure of carbon dioxide in arterial blood (PaCO2) was 36â40 mmHg (4.8â5.3 kPa) in case of controlled intracranial pressure (ICP) <â20 mmHg (nâ=â45, 69%) and PaCO2 target of 30â35 mmHg (4â4.7 kPa) in case of raised ICP (nâ=â40, 62%). Almost all respondents indicated to generally treat fever (nâ=â65, 98%) with paracetamol (nâ=â61, 92%) and/or external cooling (nâ=â49, 74%). Conventional glucose management (nâ=â43, 66%) was preferred over tight glycemic control (nâ=â18, 28%). More than half of the respondents indicated to aim for full caloric replacement within 7 days (nâ=â43, 66%) using enteral nutrition (nâ=â60, 92%). Indications for and duration of seizure prophylaxis varied, and levetiracetam was mostly reported as the agent of choice for both seizure prophylaxis (nâ=â32, 49%) and treatment (nâ=â40, 61%).
Conclusions
Practice preferences vary substantially regarding general supportive and preventive measures in TBI patients at ICUs of European neurotrauma centers. These results provide an opportunity for future comparative effectiveness research, since a more evidence-based uniformity in good practices in general ICU management could have a major impact on TBI outcome
Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19
IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19.
Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19.
DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 nonâcritically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022).
INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (nâ=â257), ARB (nâ=â248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; nâ=â10), or no RAS inhibitor (control; nâ=â264) for up to 10 days.
MAIN OUTCOMES AND MEASURES The primary outcome was organ supportâfree days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes.
RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ supportâfree days among critically ill patients was 10 (â1 to 16) in the ACE inhibitor group (nâ=â231), 8 (â1 to 17) in the ARB group (nâ=â217), and 12 (0 to 17) in the control group (nâ=â231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ supportâfree days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively).
CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes.
TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570
Preparation and reactions of polymers and copolymers of 2-methylbut-1-en-3-one, and related studies.
Poly(2-methylbut-1-en-3-one) was prepared by bulk polymerisation with azobisisobutyronitrile as initiator. Six copolymers of 2-methylbut-l-en-3-one and styrene in various ratios were prepared similarly. The homopolymer on treatment in solution with hydrogen chloride gave a product in which water had been condensed from neighbouring acetyl side-chains to give a polymer containing series of conjugated double bonds. The homopolymer was oxidised with aqueous alkaline potassium permanganate to give a copolymer of methacrylic acid and 3-niethylbut-3-en-2-oxo-1-oic acid. The homopolymer was reduced with lithium aluminium hydride in tetrahydrofuran to give a product containing 70% of secondary alcohol groups. The homopolymer was treated with hydroxylamine hydrochloride in pyridine to give a product containing oxime groups, oxime anhydride groups and unreacted ketone groups. The 1:2-copolymer was brominated to give a product in which all the methyl ketone side-chains had been converted to bromomethyl ketone side-chains. The brominated 1:2-copolymer was reacted with thiourea to give a copolymer in which all the bromine had been replaced by isothiourea groups. Where possible low molecular weight analogues of the polymers were prepared, based on 2,2-dimethylbutan-3-one. The infra-red spectra of the polymers and polymeric derivatives were compared with those of the low molecular weight analogues. The reactivities of the above polymeric compounds are discussed in relation to the characteristics of the corresponding molecular models