40 research outputs found

    To bend or not to bend – are heteroatom interactions within conjugated molecules effective in dictating conformation and planarity?

    Get PDF
    We consider the roles of heteroatoms (mainly nitrogen, the halogens and the chalcogens) in dictating the conformation of linear conjugated molecules and polymers through non-covalent intramolecular interactions. Whilst hydrogen bonding is a competitive and sometimes more influential interaction, we provide unambiguous evidence that heteroatoms are able to determine the conformation of such materials with reasonable predictability

    Magnitude of and Prognostic Factors Associated With 1-Year Mortality After Hospital Discharge for Acute Decompensated Heart Failure Based on Ejection Fraction Findings

    Get PDF
    BACKGROUND: Limited data exist about the magnitude of and the factors associated with prognosis within 1 year for patients discharged from the hospital after acute decompensated heart failure. Data are particularly limited from the more generalizable perspective of a population-based investigation and should be further stratified according to currently recommended ejection fraction (EF) findings. METHODS AND RESULTS: The hospital medical records of residents of the Worcester, Massachusetts, metropolitan area who were discharged after acute decompensated heart failure from all 11 medical centers in central Massachusetts during 1995, 2000, 2002, 2004, and 2006 were reviewed. The average age of the 4025 study patients was 75 years, 93% were white, and 44% were men. Of these, 35% (n=1414) had reduced EF ( \u3c /=40%), 13% (n=521) had borderline preserved EF (41-49%), and 52% (n=2090) had preserved EF ( \u3e /=50%); at 1 year after discharge, death rates were 34%, 30%, and 29%, respectively (P=0.03). Older age, a history of chronic obstructive pulmonary disease, systolic blood pressure findings \u3c 150 mm Hg on admission, and hyponatremia were important predictors of 1-year mortality for all study patients, whereas several comorbidities and physiological factors were differentially associated with 1-year death rates in patients with reduced, borderline preserved, and preserved EF. CONCLUSIONS: This population-based study highlights the need for further contemporary research into the characteristics, treatment practices, natural history, and long-term outcomes of patients with acute decompensated heart failure and varying EF findings and reinforces ongoing discussions about whether different treatment guidelines may be needed for these patients to design more personalized treatment plans

    Survival after hospital discharge for ST-segment elevation and non-ST-segment elevation acute myocardial infarction: a population-based study

    Get PDF
    BACKGROUND: Limited recent data are available describing differences in long-term survival, and factors affecting prognosis, after ST-segment elevation myocardial infarction (STEMI) and non-ST-segment elevation myocardial infarction (NSTEMI), especially from the more generalizable perspective of a population-based investigation. The objectives of this study were to examine differences in post-discharge prognosis after hospitalization for STEMI and NSTEMI, with a particular focus on factors associated with reduced long-term survival. METHODS: We reviewed the medical records of residents of the Worcester, MA, USA metropolitan area hospitalized at eleven central Massachusetts medical centers for acute myocardial infarction (AMI) during 2001, 2003, 2005, and 2007. RESULTS: A total of 3762 persons were hospitalized with confirmed AMI; of these, 2539 patients (67.5%) were diagnosed with NSTEMI. The average age of study patients was 70.3 years and 42.9% were women. Patients with NSTEMI experienced higher post-discharge death rates with 3-month, 1-year, and 2-year death rates of 12.6%, 23.5%, and 33.2%, respectively, compared to 6.1%, 11.5%, and 16.4% for patients with STEMI. After multivariable adjustment, patients with NSTEMI were significantly more likely to have died after hospital discharge (adjusted hazards ratio 1.28; 95% confidence interval 1.14-1.44). Several demographic (eg, older age) and clinical (eg, history of stroke) factors were associated with reduced long-term survival in patients with NSTEMI and STEMI. CONCLUSIONS: The results of this study in residents of central Massachusetts suggest that patients with NSTEMI are at higher risk for dying after hospital discharge, and several subgroups are at particularly increased risk

    Non-covalent close contacts in fluorinated thiophene-phenylene-thiophene conjugated units: understanding the nature and dominance of O···H versus S···F and O···F interactions towards the control of polymer conformation

    Get PDF
    Using a simple -conjugated trimer, EDOT-phenylene-EDOT (where EDOT = 3,4-ethylenedioxythiophene), we evaluate the effect that fluorine substituents have upon changes in conformation, conjugation and oxidation potentials in -conjugated structures. These variations are assessed as a function of the fluorine atom’s propensity to feature in hydrogen and/or halogen bonding with other heteroatoms. The molecular motif was chosen because the EDOT unit presents the possibility of competing O···X or S···X non-covalent contacts (where X = H or F). Such non-bonding interactions are acknowledged to be highly influential in dictating molecular and polymer morphology and inducing changes in certain physical properties. We have studied four compounds, beginning with an unsubstituted bridging phenylene ring and then adding one, two or four fluorine units to the parent molecule. Our studies involve single crystal XRD studies, cyclic voltammetry, absorption spectroscopy and density functional theory calculations to identify the dominant non-covalent interactions and elucidate their effects on the molecules described. Experimental studies have also been carried out on the corresponding electrochemically synthesized polymers to confirm that these non-covalent interactions and their effects persist in polymers. Our findings show that hydrogen bonding and halogen bonding feature in these molecules and their corresponding polymers. ABSTRACT: Using a simple -conjugated trimer, EDOT-phenylene-EDOT (where EDOT = 3,4-ethylenedioxythiophene), we evaluate the effect that fluorine substituents have upon changes in conformation, conjugation and oxidation potentials in -conjugated structures. These variations are assessed as a function of the fluorine atom’s propensity to feature in hydrogen and/or halogen bonding with other heteroatoms. The molecular motif was chosen because the EDOT unit presents the possibility of competing O···X or S···X non-covalent contacts (where X = H or F). Such non-bonding interactions are acknowledged to be highly influential in dictating molecular and polymer morphology and inducing changes in certain physical properties. We have studied four compounds, beginning with an unsubstituted bridging phenylene ring and then adding one, two or four fluorine units to the parent molecule. Our studies involve single crystal XRD studies, cyclic voltammetry, absorption spectroscopy and density functional theory calculations to identify the dominant non-covalent interactions and elucidate their effects on the molecules described. Experimental studies have also been carried out on the corresponding electrochemically synthesized polymers to confirm that these non-covalent interactions and their effects persist in polymers. Our findings show that hydrogen bonding and halogen bonding feature in these molecules and their corresponding polymers

    Accelerated surgery versus standard care in hip fracture (HIP ATTACK): an international, randomised, controlled trial

    Get PDF

    Proceedings of the Thirteenth International Society of Sports Nutrition (ISSN) Conference and Expo

    Get PDF
    Meeting Abstracts: Proceedings of the Thirteenth International Society of Sports Nutrition (ISSN) Conference and Expo Clearwater Beach, FL, USA. 9-11 June 201

    PANC Study (Pancreatitis: A National Cohort Study): national cohort study examining the first 30 days from presentation of acute pancreatitis in the UK

    Get PDF
    Abstract Background Acute pancreatitis is a common, yet complex, emergency surgical presentation. Multiple guidelines exist and management can vary significantly. The aim of this first UK, multicentre, prospective cohort study was to assess the variation in management of acute pancreatitis to guide resource planning and optimize treatment. Methods All patients aged greater than or equal to 18 years presenting with acute pancreatitis, as per the Atlanta criteria, from March to April 2021 were eligible for inclusion and followed up for 30 days. Anonymized data were uploaded to a secure electronic database in line with local governance approvals. Results A total of 113 hospitals contributed data on 2580 patients, with an equal sex distribution and a mean age of 57 years. The aetiology was gallstones in 50.6 per cent, with idiopathic the next most common (22.4 per cent). In addition to the 7.6 per cent with a diagnosis of chronic pancreatitis, 20.1 per cent of patients had a previous episode of acute pancreatitis. One in 20 patients were classed as having severe pancreatitis, as per the Atlanta criteria. The overall mortality rate was 2.3 per cent at 30 days, but rose to one in three in the severe group. Predictors of death included male sex, increased age, and frailty; previous acute pancreatitis and gallstones as aetiologies were protective. Smoking status and body mass index did not affect death. Conclusion Most patients presenting with acute pancreatitis have a mild, self-limiting disease. Rates of patients with idiopathic pancreatitis are high. Recurrent attacks of pancreatitis are common, but are likely to have reduced risk of death on subsequent admissions. </jats:sec

    Factors Associated with Revision Surgery after Internal Fixation of Hip Fractures

    Get PDF
    Background: Femoral neck fractures are associated with high rates of revision surgery after management with internal fixation. Using data from the Fixation using Alternative Implants for the Treatment of Hip fractures (FAITH) trial evaluating methods of internal fixation in patients with femoral neck fractures, we investigated associations between baseline and surgical factors and the need for revision surgery to promote healing, relieve pain, treat infection or improve function over 24 months postsurgery. Additionally, we investigated factors associated with (1) hardware removal and (2) implant exchange from cancellous screws (CS) or sliding hip screw (SHS) to total hip arthroplasty, hemiarthroplasty, or another internal fixation device. Methods: We identified 15 potential factors a priori that may be associated with revision surgery, 7 with hardware removal, and 14 with implant exchange. We used multivariable Cox proportional hazards analyses in our investigation. Results: Factors associated with increased risk of revision surgery included: female sex, [hazard ratio (HR) 1.79, 95% confidence interval (CI) 1.25-2.50; P = 0.001], higher body mass index (fo

    Fisheries long term monitoring program : Mud Crab (Scylla serrata) Report: 2000-–2002

    Get PDF
    The Queensland Department of Primary Industries and Fisheries (DPI&F) manages the harvest of Queensland’s fish, mollusc and crustacean species and the habitats they live in and is committed to monitor the condition and trends in fish populations and their habitats. This information is used to assess the effectiveness of fisheries management strategies ensuring that the fisheries continue to be ecologically sustainable. Two species of mud crab, Scylla serrata and S. olivacea, are found in Queensland waters (Keenan et al. 1998). The most abundant of these species in Queensland is S. serrata. The annual Queensland harvest of mud crabs, primarily S. serrata, has been steadily increasing from approximately 200 t in 1988 to around 1000 t in 2000 - 2001. Commercial catch rates remained relatively constant at about 20 kg/day until 1997, increasing to 26 kg/day in 2000 - 2001. The high value of the fishery ($10.4 M) (Williams 2002), increasing catch rates and increasing total effort combined with general public pressure to review the suitability of current management arrangements, resulted in mud crabs being included in the DPI&F, Long Term Monitoring Program (LTMP). The objectives of the mud crab monitoring was to obtain fishery-independent catch per unit effort data to estimate annual changes in relative abundance, record size frequency and sex ratios for long-term comparison of population structure and population sustainability indicators, and to record changes in habitat, water quality, effects of fishing pressure and several additional abiotic variables. The sampling design included 17 regions statewide, from the Gulf of Carpentaria in north-western Queensland to Moreton Bay in south-eastern Queensland. Each region was stratified into four locations - foreshore, mouth, mid- and upper-estuarine. Standard commercially available Munyana© brand crab pots are used to conduct 20 pot sets annually at each location. Bycatch (species not targeted and not kept) in the mud crab fishery, is relatively low in both amount and diversity when compared to other fisheries (Barker et al. 2004). Bycatch retained in pots is predominantly alive and can be released in good condition at the point of capture. The setting of pots to reduce exposure during periods of low tide can reduce the mortality of bycatch species. The statewide summary of water quality data yields few correlations between the various water quality parameters and mud crab catches. However, there is anecdotal evidence from LTMP staff, researchers and recreational and commercial fishers that water quality does effect the location, sex and number of crabs that can be caught. Significant differences in mean carapace width were observed between male and female crabs, between regions and between locations. However, the magnitude of these differences was often small. The size frequency of male crabs declines sharply above the 150 mm minimum carapace width where as female crabs show a bimodal size frequency distribution. This correlates with the minimum legal size, and it is likely the size frequency of male crab is influenced by fishing mortality. The difference in mean carapace width between locations showed a trend towards smaller crabs the further upstream the sampling occurred. Investigation of mean standardised catch rates shows lower catch rates and lower proportions of female crabs in the Gulf of Carpentaria than on the east coast. There were higher proportions of sub-legal male crabs than legal male crabs in close proximity to major urban areas a result that suggests fishing pressure (commercial and recreational) is higher in these areas
    corecore