104 research outputs found

    Wall slip, shear banding, and instability in the flow of a triblock copolymer micellar solution

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    The shear flow of a triblock copolymer micellar solution (PEO--PPO--PEO Pluronic P84 in brine) is investigated using simultaneous rheological and velocity profile measurements in the concentric cylinder geometry. We focus on two different temperatures below and above the transition temperature TcT_c which was previously associated with the apparition of a stress plateau in the flow curve. (i) At T=37.0T=37.0^\circC <Tc<T_c, the bulk flow remains homogeneous and Newtonian-like, although significant wall slip is measured at the rotor that can be linked to an inflexion point in the flow curve. (ii) At T=39.4T=39.4^\circC >Tc>T_c, the stress plateau is shown to correspond to stationary shear-banded states characterized by two high shear rate bands close to the walls and a very weakly sheared central band, together with large slip velocities at the rotor. In both cases, the high shear branch of the flow curve is characterized by flow instability. Interpretations of wall slip, three-band structure, and instability are proposed in light of recent theoretical models and experiments.Comment: 13 pages, 13 figure

    National Vascular Registry: 2015 Annual Report.

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    The National Vascular Registry is commissioned by the Healthcare Quality Improvement Partnership (HQIP) to measure the quality and outcomes of care for patients who undergo major vascular surgery in NHS hospitals in England and Wales. It aims to provide comparative information on the performance of NHS vascular units and thereby support local quality improvement as well as inform patients about major vascular interventions delivered in the NHS. As such, all NHS hospitals in England, Wales, Scotland and Northern Ireland are encouraged to participate in the Registry. The measures used to describe the patterns and outcomes of care are drawn from various national guidelines including: the “Provision of Services for Patients with Vascular Disease” document and the Quality Improvement Frameworks published by the Vascular Society, and the National Institute for Health and Care Excellence (NICE) guidelines on stroke and peripheral arterial disease. This report provides a description of the care provided by NHS vascular units, and contains information on the process and outcomes of care for: (i) patients undergoing abdominal aortic aneurysm (AAA) repair, (ii) patients undergoing carotid endarterectomy, (iii) patients undergoing a revascularisation procedure (angioplasty/stent or bypass) or major amputation for lower-limb peripheral arterial disease (PAD). In addition, the report presents the findings of an organisational audit conducted in August 2015

    National Vascular Registry: 2014 Progress Report.

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    The National Vascular Registry is commissioned by the Healthcare Quality Improvement Partnership (HQIP) to measure the quality and outcomes of care for patients who undergo major vascular surgery in NHS hospitals in England and Wales. It aims to provide comparative information on the performance of NHS hospitals and thereby support local quality improvement as well as inform patients about the care delivered in the NHS. As such, all NHS hospitals in England, Wales, Scotland and Northern Ireland are encouraged to participate in the Registry. The measures used to describe the patterns and outcomes of care are drawn from various national guidelines including: the “2014 The Provision of Services for Patients with Vascular Disease” and the Quality Improvement Frameworks published by the Vascular Society, and the National Institute for Health and Care Excellence (NICE) guidelines on stroke and peripheral arterial disease. In 2014, the Registry published NHS trust and surgeon-level information for elective infrarenal Abdominal Aortic Aneurysm (AAA) repair and carotid endarterectomy on the Registry website. From 28 October, information on both procedures has been available on the www.vsqip.org.uk website for all UK NHS trusts that currently perform them. For English NHS trusts, the same information was published for individual consultants, as part of NHS England’s “Everyone Counts: Planning for Patients 2013/4” initiative. Consultant-level information was also published for NHS hospitals in Wales, Scotland and Northern Ireland for consenting surgeons. This progress report aims to complement that information by (1) providing an overview of care delivered by the NHS at a national level, and (2) describing various developments within the National Vascular Registry. The Registry will publish its next annual report on major vascular surgery in November 2015

    Editor's Choice - Delays to Surgery and Procedural Risks Following Carotid Endarterectomy in the UK National Vascular Registry.

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    OBJECTIVE: Guidelines recommend that patients suffering an ischaemic transient ischaemic attack (TIA) or stroke caused by carotid artery stenosis should undergo carotid endarterectomy (CEA) within 14 days. METHOD: The degree to which UK vascular units met this standard was examined and whether rapid interventions were associated with procedural risks. The study analysed patients undergoing CEA between January 2009 and December 2014 from 100 UK NHS hospitals. Data were collected on patient characteristics, intervals of time from symptoms to surgery, and 30-day postoperative outcomes. The relationship between outcomes and time from symptom to surgery was evaluated using multilevel multivariable logistic regression. RESULTS: In 23,235 patients, the median time from TIA/stroke to CEA decreased over time, from 22 days (IQR 10-56) in 2009 to 12 days (IQR 7-26) in 2014. The proportion of patients treated within 14 days increased from 37% to 58%. This improvement was produced by shorter times across the care pathway: symptoms to referral, from medical review to being seen by a vascular surgeon, and then to surgery. The spread of the median time from symptom to surgery among NHS hospitals shrank between 2009 and 2013 but then grew slightly. Low-, medium-, and high-volume NHS hospitals all improved their performance similarly. Performing CEA within 48 h of symptom onset was associated with a small increase in the 30-day stroke and death rate: 3.1% (0-2 days) compared with 2.0% (3-7 days); adjusted odds ratio 1.64 (95% CI 1.04-2.59) but not with longer delays. CONCLUSIONS: The delay from symptom to CEA in symptomatic patients with ipsilateral 50-99% carotid stenoses has reduced substantially, although 42% of patients underwent CEA after the recommended 14 days. The risk of stroke after CEA was low, but there may be a small increase in risk during the first 48 h after symptoms

    Improving 1-Year Outcomes of Infrainguinal Limb Revascularization: Population-Based Cohort Study of 104 000 Patients in England.

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    BACKGROUND: The availability and diversity of lower limb revascularization procedures have increased in England in the past decade. We investigated whether these developments in care have translated to improvements in patient pathways and outcomes. METHODS: Individual-patient records from Hospital Episode Statistics were used to identify 103 934 patients who underwent endovascular (angioplasty) or surgical (endarterectomy, profundaplasty, or bypass) lower limb revascularization for infrainguinal peripheral artery disease in England between January 2006 and December 2015. Major lower limb amputations and deaths within 1 year after revascularization were ascertained from Hospital Episode Statistics and Office for National Statistics mortality records. Competing risks regression was used to estimate the cumulative incidence of major amputation and death, adjusted for patient age, sex, comorbidity score, indication for the intervention (intermittent claudication, severe limb ischemia without record of tissue loss, severe limb ischemia with a record of ulceration, severe limb ischemia with a record of gangrene/osteomyelitis), and comorbid diabetes mellitus. RESULTS: The estimated 1-year risk of major amputation decreased from 5.7% (in 2006-2007) to 3.9% (in 2014-2015) following endovascular revascularization, and from 11.2% (2006-2007) to 6.6% (2014-2015) following surgical procedures. The risk of death after both types of revascularization also decreased. These trends were observed for all indication categories, with the largest reductions found in patients with severe limb ischemia with ulceration or gangrene. Overall, morbidity increased over the study period, and a larger proportion of patients was treated for the severe end of the peripheral artery disease spectrum using less invasive procedures. CONCLUSIONS: Our findings show that from 2006 to 2015, the overall survival increased and the risk of major lower limb amputation decreased following revascularization. These observations suggest that patient outcomes after lower limb revascularization have improved during a period of centralization and specialization of vascular services in the United Kingdom

    BIOAKTIVITAS ASAP CAIR DAUN JATI (Tectona grandis) TERHADAP JAMUR PELAPUK PUTIH (Schizophyllum commune): Bioactivity of Liquid Smoke from Teak Leafs (Tectona grandis) Agains White Root Fungus (Schizophyllum commune)

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    This research aimed to evaluate the bioactivity of liquid smoke from teak leaves to the Schizophyllum commune Fries fungus. The research was conducted in several steps,i.e., pyrolysis of liquid smoke and efficacy test of liquid smoke as an antifungal. The agar media used was PDA (potatoes dextrose agar). The concentration of liquid smoke used for the treatment were 0; 0.25%; 0.50%; 0.75%; 1.00%; 1.25%; and 1.50% (v/v). The results indicated that the liquid smoke inhibited the Schizophyllum commune fungi growth. The concentration of liquid smoke resulted in significantly different antifungal activities. Liquid smoke with a concentration of 1% and 1.25% produced an average antifungal activity of 44.44% with a somewhat resistant category. The contents of organic fractions of liquid smoke, such as acid and phenol, might be responsible for these antifungal activities.Penelitian ini bertujuan untuk mengetahui bioaktivitas asap cair dari daun jati (Tectona grandis) terhadap jamur schizophyllum commune. Penelitian ini dilakukan dalam beberapa langkah, yaitu pirolisis asap cair dan uji efikasi asap cair sebagai antijamur. Media yang digunakan adalah PDA (Potato Detxtrose Agar). Konsentrasi asap cair yang digunakan untuk pengujian adalah 0,25%, 0,50%, 0,75%, 1%, dan 1,25% (v/v). Hasilnya menunjukan bahwa cairan asap cair daun jati menghambat pertumbuhan jamur Schizophyllum commune. Konsentrasi asap cair menghasilkan aktifitas antijamur yang berbeda secara signifikan. Asap cair dengan konsentrasi 1% dan 1,25% menghasilkan nilai rata-rata aktifitas antijamur sebesar 44,44% dengan kategorI agak tahan. Kandungan fraksi organik dalam&nbsp; asap cair seperti fenol dan asam asetat diduga menjadi penyebab terjadinya aktifitas antijamur

    Population-based study of mortality and major amputation following lower limb revascularization.

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    BACKGROUND: The aim of this study was to estimate separate risks of major lower limb amputation and death following revascularization for peripheral artery disease (PAD) using competing risks analysis. METHODS: Routinely collected data from Hospital Episode Statistics (HES) were used to identify patients who underwent endovascular or open lower limb revascularization for PAD in England from 2005 to 2015. The primary outcomes were major lower limb amputation and death within 5 years of revascularization. Cox proportional hazards and Fine-Gray competing risks regression were used to examine the competing risks of these outcomes. RESULTS: Some 164 845 patients underwent their first lower limb revascularization for PAD during the study interval. Most were men (64·6 per cent) and the median age was 71 (i.q.r. 62-78) years. Following endovascular revascularization, the 5-year cumulative incidence of amputation was 4·2 per cent in patients with intermittent claudication and 18·0 per cent in those with a record of tissue loss. The corresponding rates were 10·8 and 25·3 per cent respectively after open revascularization, and 8·1 and 25·0 per cent after combined procedures. The 5-year cumulative incidence of death varied from 24·5 to 39·8 per cent, depending on procedure type. Competing risks methods consistently produced lower estimates than standard methods. CONCLUSION: The 5-year risk of major amputation following lower limb revascularization for PAD appears lower than estimated previously. Patients undergoing revascularization for tissue loss and those who require an open procedure are at highest risk of limb loss

    Long-term survival after endovascular and open repair of unruptured abdominal aortic aneurysm.

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    BACKGROUND: The aim of this study was to examine patterns of 10-year survival after elective repair of unruptured abdominal aortic aneurysms (AAAs) in different patient groups. METHODS: Patients having open repair or endovascular aneurysm repair (EVAR) in the English National Health Service between January 2006 and December 2015 were identified from Hospital Episode Statistics data. Postoperative survival among patients of different age and Royal College of Surgeons of England (RCS) modified Charlson co-morbidity score profiles were analysed using flexible parametric survival models. The relationship between patient characteristics and risk of rupture after repair was also analysed. RESULTS: Some 37 138 patients underwent elective AAA repair, of which 15 523 were open and 21 615 were endovascular. The 10-year mortality rate was 38·1 per cent for patients aged under 70 years, and the survival trajectories for open repair and EVAR were similar when patients had no RCS-modified Charlson co-morbidity. Among older patients or those with co-morbidity, the 10-year mortality rate rose, exceeding 70 per cent for patients aged 80 years. Mean survival times over 10 years for open repair and EVAR were often similar in subgroups of older and more co-morbid patients, but their survival trajectories became increasingly dissimilar, with open repair showing greater short-term risk within 6 months but lower 10-year mortality rates. The risk of rupture over 9 years was 3·4 per cent for EVAR and 0·9 per cent for open repair, and was weakly associated with patient factors. CONCLUSION: Long-term survival patterns after elective open repair and EVAR for unruptured AAA vary markedly across patients with different age and co-morbidity profiles

    Volumetric versus single slice measurements of core abdominal muscle for Sarcopenia

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    Objectives: We investigated whether total psoas muscle area (TPMA) was representative of the total psoas muscle volume (TPMV). Secondly, we assessed whether there was a relationship between the two commonly used single slice measurements of sarcopenia, TPMA and total abdominal muscle area (TAMA). Methods: Pre-operative CT imaging of 110 patients undergoing elective endovascular aneurysm repair were analysed by two trained independent observers. TPMA was measured at individual vertebral levels between the second lumbar vertebrae and sacrum. TPMV was also estimated between the second lumbar vertebrae and sacrum. TAMA was measured at the third lumbar vertebrae (L3). Observer differences were assessed using Bland-Altman plots. Associations between the different measures were assessed using linear regression and Pearson's correlation. Results: We found single slice measurements of the TPMA to be representative of the TPMV at individual levels between L2 to the sacrum. The strongest association was seen at L3 (adjusted regression coefficient 16.7, 95% CI 12.1 to 21.4, p < 0.001). There was no association between TPMA and TAMA (adjusted regression coefficient - 0.7, 95% CI - 4.1 to 2.8, p = 0.710). Conclusions: We demonstrate that measurements of the TPMA between L2 to the sacrum are representative of the TPMV, with the greatest association at the third lumbar vertebrae. There was no association between the TPMA and TAMA. Advances in Knowledge: We demonstrate that a single slice measurement of TPMA at L3 is representative of the muscle volume, contrary to previous criticism. Future sarcopenia studies can continue to measure TPMA which is representative of the TPMV
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