| 1. |
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| 2. |
- Abelev, Betty, et al.
(författare)
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Underlying Event measurements in pp collisions at root s=0.9 and 7 TeV with the ALICE experiment at the LHC
- 2012
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Ingår i: Journal of High Energy Physics. - 1029-8479. ; :7
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Tidskriftsartikel (refereegranskat)abstract
- We present measurements of Underlying Event observables in pp collisions at root s = 0 : 9 and 7 TeV. The analysis is performed as a function of the highest charged-particle transverse momentum p(T),L-T in the event. Different regions are defined with respect to the azimuthal direction of the leading (highest transverse momentum) track: Toward, Transverse and Away. The Toward and Away regions collect the fragmentation products of the hardest partonic interaction. The Transverse region is expected to be most sensitive to the Underlying Event activity. The study is performed with charged particles above three different p(T) thresholds: 0.15, 0.5 and 1.0 GeV/c. In the Transverse region we observe an increase in the multiplicity of a factor 2-3 between the lower and higher collision energies, depending on the track p(T) threshold considered. Data are compared to PYTHIA 6.4, PYTHIA 8.1 and PHOJET. On average, all models considered underestimate the multiplicity and summed p(T) in the Transverse region by about 10-30%.
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| 3. |
- Khatri, C, et al.
(författare)
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Outcomes after perioperative SARS-CoV-2 infection in patients with proximal femoral fractures: an international cohort study
- 2021
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Ingår i: BMJ open. - : BMJ. - 2044-6055. ; 11:11, s. e050830-
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Tidskriftsartikel (refereegranskat)abstract
- Studies have demonstrated high rates of mortality in people with proximal femoral fracture and SARS-CoV-2, but there is limited published data on the factors that influence mortality for clinicians to make informed treatment decisions. This study aims to report the 30-day mortality associated with perioperative infection of patients undergoing surgery for proximal femoral fractures and to examine the factors that influence mortality in a multivariate analysis.SettingProspective, international, multicentre, observational cohort study.ParticipantsPatients undergoing any operation for a proximal femoral fracture from 1 February to 30 April 2020 and with perioperative SARS-CoV-2 infection (either 7 days prior or 30-day postoperative).Primary outcome30-day mortality. Multivariate modelling was performed to identify factors associated with 30-day mortality.ResultsThis study reports included 1063 patients from 174 hospitals in 19 countries. Overall 30-day mortality was 29.4% (313/1063). In an adjusted model, 30-day mortality was associated with male gender (OR 2.29, 95% CI 1.68 to 3.13, p<0.001), age >80 years (OR 1.60, 95% CI 1.1 to 2.31, p=0.013), preoperative diagnosis of dementia (OR 1.57, 95% CI 1.15 to 2.16, p=0.005), kidney disease (OR 1.73, 95% CI 1.18 to 2.55, p=0.005) and congestive heart failure (OR 1.62, 95% CI 1.06 to 2.48, p=0.025). Mortality at 30 days was lower in patients with a preoperative diagnosis of SARS-CoV-2 (OR 0.6, 95% CI 0.6 (0.42 to 0.85), p=0.004). There was no difference in mortality in patients with an increase to delay in surgery (p=0.220) or type of anaesthetic given (p=0.787).ConclusionsPatients undergoing surgery for a proximal femoral fracture with a perioperative infection of SARS-CoV-2 have a high rate of mortality. This study would support the need for providing these patients with individualised medical and anaesthetic care, including medical optimisation before theatre. Careful preoperative counselling is needed for those with a proximal femoral fracture and SARS-CoV-2, especially those in the highest risk groups.Trial registration numberNCT04323644
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| 4. |
- Mishra, A, et al.
(författare)
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Diminishing benefits of urban living for children and adolescents' growth and development
- 2023
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 1476-4687 .- 0028-0836. ; 615:7954, s. 874-883
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Tidskriftsartikel (refereegranskat)abstract
- Optimal growth and development in childhood and adolescence is crucial for lifelong health and well-being1–6. Here we used data from 2,325 population-based studies, with measurements of height and weight from 71 million participants, to report the height and body-mass index (BMI) of children and adolescents aged 5–19 years on the basis of rural and urban place of residence in 200 countries and territories from 1990 to 2020. In 1990, children and adolescents residing in cities were taller than their rural counterparts in all but a few high-income countries. By 2020, the urban height advantage became smaller in most countries, and in many high-income western countries it reversed into a small urban-based disadvantage. The exception was for boys in most countries in sub-Saharan Africa and in some countries in Oceania, south Asia and the region of central Asia, Middle East and north Africa. In these countries, successive cohorts of boys from rural places either did not gain height or possibly became shorter, and hence fell further behind their urban peers. The difference between the age-standardized mean BMI of children in urban and rural areas was <1.1 kg m–2 in the vast majority of countries. Within this small range, BMI increased slightly more in cities than in rural areas, except in south Asia, sub-Saharan Africa and some countries in central and eastern Europe. Our results show that in much of the world, the growth and developmental advantages of living in cities have diminished in the twenty-first century, whereas in much of sub-Saharan Africa they have amplified.
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| 5. |
- Quintana, Miguel, et al.
(författare)
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Assessment of atrial regional and global electromechanical function by tissue velocity echocardiography : a feasibility study on healthy individuals
- 2005
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Ingår i: Cardiovascular Ultrasound. - : Springer Science and Business Media LLC. - 1476-7120. ; 3:18 February 2005
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The appropriate evaluation of atrial electrical function is only possible by means of invasive electrophysiology techniques, which are expensive and therefore not suitable for widespread use. Mechanical atrial function is mainly determined from atrial volumes and volume-derived indices that are load-dependent, time-consuming and difficult to reproduce because they are observer-dependent. AIMS: To assess the feasibility of tissue velocity echocardiography (TVE) to evaluate atrial electromechanical function in young, healthy volunteers. SUBJECTS AND METHODS: We studied 37 healthy individuals: 28 men and nine women with a mean age of 29 years (range 20-47). Standard two-dimensional (2-D) and Doppler echocardiograms with superimposed TVE images were performed. Standard echocardiographic images were digitized during three consecutive cardiac cycles in cine-loop format for off-line analysis. Several indices of regional atrial electrical and mechanical function were derived from both 2-D and TVE modalities. RESULTS: Some TVE-derived variables indirectly reflected the atrial electrical activation that follows the known activation process as revealed by invasive electrophysiology. Regionally, the atrium shows an upward movement of its walls at the region near the atrio-ventricular ring with a reduction of this movement towards the upper levels of the atrial walls. The atrial mechanical function as assessed by several TVE-derived indices was quite similar in all left atrium (LA) walls. However, all such indices were higher in the right (RA) than the LA. There were no correlations between the 2-D- and TVE-derived variables expressing atrial mechanical function. Values of measurement error and repeatability were good for atrial mechanical function, but only acceptable for atrial electrical function. CONCLUSION: TVE may provide a simple, easy to obtain, reproducible, repeatable and potentially clinically useful tool for quantifying atrial electromechanical function.
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| 6. |
- Quintana, Miguel, et al.
(författare)
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Cardiac incoordination induced by left bundle branch block : its relation with left ventricular systolic function in patients with and without cardiomyopathy
- 2008
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Ingår i: Cardiovascular Ultrasound. - : Springer Science and Business Media LLC. - 1476-7120. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Although left bundle branch block (LBBB) alters the electrical activation of the heart, it is unknown how it might change the process of myocardial coordination (MC) and how it may affect the left ventricular (LV) systolic function. The present study assessed the effects of LBBB on MC in patients with LBBB with and without dilated (DCMP) or ischemic cardiomyopathy (ICMP). METHODS: Tissue Doppler echocardiography (TDE) was performed in 86 individuals: 21 with isolated LBBB, 26 patients with DCMP + LBBB, 19 patients with ICMP + LBBB and in 20 healthy individuals (Controls). MC was assessed analyzing the myocardial velocity profiles obtained from six basal segments of the LV using TDE. The LV systolic function was assessed by standard two-dimensional echocardiography and by TDE. RESULTS: Severe alterations in MC were observed in subjects with LBBB as compared with controls (P < 0.01 for all comparisons); these derangements were even worse in patients with DCMP and ICMP (P < 0.001 for comparisons with Controls and P < 0.01 for comparison with individuals with isolated LBBB). Some parameters of MC differed significantly between DCMP and ICMP (P < 0.01). A good or very good correlation coefficient was found between variables of MC and variables of LV systolic function. CONCLUSION: LBBB induces severe derangement in the process of MC that are more pronounced in patients with cardiomyopathies and that significantly correlates with the LV systolic function. The assessment of MC may help in the evaluation of the etiology of dilated cardiomyopathy.
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| 7. |
- Quintana, Miguel
(författare)
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Unstable post-infarction ischemia : identification and risk stratification with special emphasis on noninvasive methods
- 1996
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Although in-hospital mortality after acute myocardial infarction has decreased, long-term mortality is still high. This study tested the prognostic value of detecting residual myocardial ischemia by different techniques in 74 patients recovering from an acute myocardial infarction. The prevalence and prognostic significance of ST-segment depression detected by ambulatory electrocardiography was studied. The prognosis in 22 (30%) patients with ST-segment depression was worse than in 52 (70%) without, regarding short-term cardiac events (defined as death or reinfarction or revascularization) (P<0.01), long-term mortality (P=0.01) and long-term cardiac events (P<0.001). Compared with clinical variables in a multivariate regression analysis, ST-segment depression was the strongest covariate assessing prognosis. Due to the high prevalence of prolonged or fixed ST-segment depression during ambulatory electrocardiography, new methods to detect ST-segment changes were assessed. ST-segment changes were analyzed from four reference levels. ST-segment elevation was measured 0 to 5 ms after the J point. The presence of ST-segment elevation measured from a 24-hour median level was statistically associated with mortality (P=0.03). The sensitivity, specificity and accuracy of ST-depression/ST-elevation measured from the 24-hour median level in predicting mortality were 78%, 71% and 73%, respectively. These values are higher than those reported for ST-segment depression detected during exercise testing. The prognostic value of ST-segment depression detected by ambulatory electrocardiography was compared with the outcome of exercise testing. Both tests were able to predict death, death or nonfatal infarction and cardiac events. The sensitivity of both methods to assess death and death or nonfatal infarction was similar. The specificity of ambulatory electrocardiography was superior in predicting death (P=0.01) and death or nonfatal infarction (P=0.001). When both techniques were combined, the studied population could be classified in groups with low, medium and high risks. ST-segment depression detected by ambulatory electrocardiography was a stronger covariatein predicting mortality than exercise-induced ST-segment depression. The prognostic value of predischarge stress echocardiography was studied. The method was compared with exercise testing and clinical variables. A positive stress echocardiography was associated with a poor prognosis (mortality:P=0.0002; cardiac events: P<0.0001). Even revascularization procedures, subsequently decided upon the results of exercise testing and clinical symptoms, were predicted by the initial stress echocardiogram (P=0.02). A new-onset wall motion abnormality during stress echocardiography was the strongest variable predicting death and death or nonfatal infarction. The cardiac sympatho-vagal regulation was studied immediately after the acute phase of AMI. Heart rate variability was evaluated in the time and frequency domains. Heart rate variability was compared in survivors, nonsurvivors and a group of 24 healthy controls. Heart rate variability was higher in survivors than in nonsurvivors (P=0.005), higher in controls than in survivors (P=0.05), higher in controls than in nonsurvivors (P=0.0001) and higher inpatients without cardiac events and reinfarction (P=0.03 and P=0.03, respectively). In a multivariate regression analysis, including clinical variables and left ventricular ejection fraction in the model, heart rate variability retained its independent and additive prognostic value. The prognostic value of several clinical variables and variables derived from diverse noninvasive methods was investigated in a two-stage multivariate stepwise regression analysis. The following covariates were tested: clinical variables, ST-segment changes detected on ambulatory electrocardiography and exercise testing, heart rate variability, ejection fraction, wall motion score index, worsened or new-onset wall motion abnormality on stress echocardiography and different physiological variables obtained during exercise testing. At the second stage of this multivariate analysis only new-onset wall motion abnormality, ST-segment depression on ambulatory electrocardiography and decreased heart rate variability had additive and independent value to predict mortality. In conclusion, residual myocardial ischemia detected by different techniques was the strongest factor predicting long-term mortality and should be studied in all patients recovering from an acute myocardial infarction.
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| 8. |
- Sadigh, Bita, et al.
(författare)
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The ischemic preconditioning effect of adenosine in patients with ischemic heart disease
- 2009
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Ingår i: Cardiovascular Ultrasound. - : Springer Science and Business Media LLC. - 1476-7120. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: In vivo and in vitro evidence suggests that adenosine and its agonists play key roles in the process of ischemic preconditioning. The effects of low-dose adenosine infusion on ischemic preconditioning have not been thoroughly studied in humans. AIMS: We hypothesised that a low-dose adenosine infusion could reduce the ischemic burden evoked by physical exercise and improve the regional left ventricular (LV) systolic function. MATERIALS AND METHODS: We studied nine severely symptomatic male patients with severe coronary artery disease. Myocardial ischemia was induced by exercise on two separate occasions and quantified by Tissue Doppler Echocardiography. Prior to the exercise test, intravenous low-dose adenosine or placebo was infused over ten minutes according to a randomized, double blind, cross-over protocol. The LV walls were defined as ischemic if a reduction, no increment, or an increment of < 15% in peak systolic velocity (PSV) was observed during maximal exercise compared to the baseline values observed prior to placebo-infusion. Otherwise, the LV walls were defined as non-ischemic. RESULTS: PSV increased from baseline to maximal exercise in non-ischemic walls both during placebo (P = 0.0001) and low-dose adenosine infusion (P = 0.0009). However, in the ischemic walls, PSV increased only during low-dose adenosine infusion (P = 0.001), while no changes in PSV occurred during placebo infusion (P = NS). CONCLUSION: Low-dose adenosine infusion reduced the ischemic burden and improved LV regional systolic function in the ischemic walls of patients with exercise-induced myocardial ischemia, confirming that adenosine is a potential preconditioning agent in humans.
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| 9. |
- Santos, Sara M., et al.
(författare)
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Use of bacterial cellulose in degraded paper restoration. Part I : application on model papers
- 2016
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Ingår i: Journal of Materials Science. - : Springer Science and Business Media LLC. - 0022-2461 .- 1573-4803. ; 51:3, s. 1541-1552
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Tidskriftsartikel (refereegranskat)abstract
- The disappearance of bibliographic heritage is one of the biggest problems facing libraries. One of the most common methods used to restore paper, lining, is to apply a reinforcing layer to the document. This study focuses on lining papers with bacterial cellulose (BC) sheets from Gluconacetobacter sucrofermentans. For this purpose, several model papers have been selected. They have been characterized before and after the lining with this BC and a specific Japanese paper (JP) to compare both materials. Taking into account the differences between bacterial and vegetal cellulose is expected that the results may be similar to other BC and JP. The samples have been characterized before and after an aging process. There are no significant differences in some of the characteristics studied. Nevertheless, BC-lined papers present higher gloss values and b* coordinate. The wettability decreases with both BC and JP. However, in papers lined with BC, the wettability decreases more markedly and independently of the model paper used. This is related to the sealing of the surface structure by BC, which also leads to a reduction of air permeability. When the lined papers go through an aging process, there are no significant changes in any characteristic, except in b* and L* color coordinates. Additionally, the wettability rate decreases in all cases. This study indicates that papers lined with BC are stable over time. Finally, the use of BC as reinforcing material may offer advantages for specific conservation treatments, being more suitable for certain types of paper than JP.
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| 10. |
- Santos, Sara M., et al.
(författare)
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Use of bacterial cellulose in degraded paper restoration. Part II : application on real samples
- 2016
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Ingår i: Journal of Materials Science. - : Springer Science and Business Media LLC. - 0022-2461 .- 1573-4803. ; 51:3, s. 1553-1561
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Tidskriftsartikel (refereegranskat)abstract
- Preservation of documentary heritage is one of the biggest challenges facing paper conservators today. The singular properties of bacterial cellulose (BC) lead us to propose to reinforce paper with BC sheets. In the first part of this study, the reinforcing capability of BC was tested on model papers of well-known fiber composition. The aim of the present study was to verify the suitability of rebuilding degraded old papers with BC. The degraded papers were characterized before and after the reinforcement. In addition, lined samples were characterized before and after an aging process in order to study the stability in time. The same methodology was used with Japanese paper (JP), a material commonly used by paper conservators, in order to compare both materials as reinforcement. Mechanical properties of paper lined with BC are as good as those obtained with JP. Papers lined with BC have more marked modifications on their optical properties than those restored with JP. Nevertheless, letters in books lined with BC are more legible. Moreover, only the papers restored with BC show high changes in porosity. The aging process leads to a slight decrement in burst index. Changes on tear index and optical properties with the aging process depend on the paper to be restored. This study suggests that BC improves deteriorated paper quality, without altering the information contained therein, and that this improvement is maintained over time. Hence, BC is a promising alternative material for the restoration of paper.
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