100 research outputs found
Analyzing Domino Effects Occurring on Gasoline Storage Tanks at the Bulk Oil Storage and Transportation (BOST) Depot
Since processed crude oil products are very vulnerable (susceptible) and highly flammable to cause massive catastrophes, such as fire and explosion, which are frequent and can create a chain reaction (Domino effects). This research was carried out at the Bulk Oil Storage and Transportation LTD depot on the Accra plain in Ghana where gasoline and Gasoil are stored. The research was conducted on a flammable gasoline area subjected to a vapor cloud explosion and the hazardous zone. Analyzing domino effects, propagation of a gasoline flammable vapor cloud caused by the explosion, ALOHA (Areal Location of Hazardous Atmospheres) software was used to find out how to apply effective safety measures to prevent future risks at any BOST facilities across the country. After the analysis, it was realized that 5.0 miles to the west-south-west the fuel concentration in the air was 2100 ppm lower than the explosive limit (LEL), and could not be as severe as that at 2.3 miles distance from the source point (12600 ppm LEL) with a greater fuel concentration in the atmosphere. The results made available would be useful in maximizing (improving) safety at the facility, residential area, and as well as minimizing future incidents
How the risk of liver cancer changes after alcohol cessation: A review and meta-analysis of the current literature
<p>Abstract</p> <p>Background</p> <p>It is well established that drinking alcohol raises the risk of liver cancer (hepatocellular carcinoma). However, it has not been sufficiently established as to whether or not drinking cessation subsequently reduces the risk of liver cancer and if it does reduce the risk how long it takes for this heightened risk to fall to that of never drinkers. This question is important for effective policy design and evaluation, to establish causality and for motivational treatments.</p> <p>Methods</p> <p>A systematic review and meta-analysis using the current available evidence and a specific form of Generalised Least Squares is performed to assess how the risk of liver cancer changes with time for former drinkers.</p> <p>Results</p> <p>Four studies are found to have quantified the effect of drinking cessation on the risk of liver cancer. The meta-analysis suggests that the risk of liver cancer does indeed fall after cessation by 6-7% a year, but there remains a large uncertainty around this estimate both statistically and in its interpretation. As an illustration it is estimated that a time period of 23 years is required after drinking cessation, with a correspondingly large 95% confidence interval of 14 to 70 years, for the risk of liver cancer to be equal to that of never drinkers.</p> <p>Conclusion</p> <p>This is a relatively under researched area and this is reflected in the uncertainty of the findings. It is our view that it is not possible to extrapolate the results found here to the general population. Too few studies have addressed this question and of the studies that have, all have significant limitations. The key issue amongst the relevant studies is that it appears that current drinkers, abstainers and former drinkers are not composed of, or effectively adjusted to be, similar populations making inferences about risk changes impossible. This is a very difficult area to study effectively, but it is an important topic. More work is required to reduce both statistical uncertainty and tackle the various study limitations this paper highlights and until this is done, the current result should be considered preliminary.</p
Анализ эффектов домино, возникающих в резервуарах для хранения бензина на складе хранения и транспортировки нефтепродуктов
Since processed crude oil products are very vulnerable (susceptible) and highly flammable to cause massive catastrophes, such as fire and explosion, which are frequent and can create a chain reaction (Domino effects). This research was carried out at the Bulk Oil Storage and Transportation LTD depot on the Accra plain in Ghana where gasoline and Gasoil are stored. The research was conducted on a flammable gasoline area subjected to a vapor cloud explosion and the hazardous zone. Analyzing domino effects, propagation of a gasoline flammable vapor cloud caused by the explosion, ALOHA (Areal Location of Hazardous Atmospheres) software was used to find out how to apply effective safety measures to prevent future risks at any BOST facilities across the country. After the analysis, it was realized that 5.0 miles to the west-south-west the fuel concentration in the air was 2100 ppm lower than the explosive limit (LEL), and could not be as severe as that at 2.3 miles distance from the source point (12600 ppm LEL) with a greater fuel concentration in the atmosphere. The results made available would be useful in maximizing (improving) safety at the facility, residential area, and as well as minimizing future incidents.Переработанные сырые нефтепродукты очень уязвимы (восприимчивы) и легко воспламеняются, что может вызвать массовые катастрофы, такие как пожары и взрывы, они случаются часто и могут вызвать цепную реакцию (эффект домино). Это исследование было проведено на складе компании Bulk Oil Storage and Transportation LTD на равнине Аккра в Гане, где хранятся бензин и дизельное топливо. Исследование проводилось на подвергшемся взрыву парового облака участке с легковоспламеняющимся бензином и на опасной зоне. Для анализа эффекта домино от распространения вызванного взрывом облака горючих паров бензина было использовано программное обеспечение ALOHA (Areal Location of Hazardous Atmospheres), чтобы выяснить, как применять эффективные меры безопасности для предотвращения будущих рисков на любых объектах BOST по всей стране. После анализа было установлено, что в 5,0 мили к западу-юго-западу концентрация топлива в воздухе была на 2100 ppm ниже предела взрываемости (LEL) и не могла быть такой сильной, как на расстоянии 2,3 мили от исходной точки (12600 ppm LEL) с большей концентрацией топлива в атмосфере. Полученные результаты будут полезны для максимизации (повышения) безопасности на объекте, в жилом районе, а также для минимизации будущих инцидентов
Haemoglobin level at birth is associated with short term outcomes and mortality in preterm infants
Background Blood volume and haemoglobin (Hb) levels are increased by delayed umbilical cord clamping, which has been reported to improve clinical outcomes of preterm infants. The objective was to determine whether Hb level at birth was associated with short term outcomes in preterm infants born at ≤32 weeks gestation. Methods Data were collected retrospectively from electronic records: Standardised Electronic Neonatal Database, Electronic Patient Record, Pathology (WinPath), and Blood Bank Electronic Database. The study was conducted in a tertiary perinatal centre with around 5,500 deliveries and a neonatal unit admission of 750 infants per year. All inborn preterm infants of 23 to 32 weeks gestational age (GA) admitted to the neonatal unit from January 2006 to September 2012 were included. The primary outcomes were intra-ventricular haemorrhage, necrotising entero-colitis, broncho-pulmonary dysplasia, retinopathy of prematurity, and death before discharge. The secondary outcomes were receiving blood transfusion and length of intensive care and neonatal unit days. The association between Hb level (g/dL) at birth and outcomes was analysed by multiple logistic regression adjusting for GA and birth weight (BWt). Results Overall, 920 infants were eligible; 28 were excluded because of missing data and 2 for lethal congenital malformation. The mean (SD) GA was 28.3 (2.7) weeks, BWt was 1,140 (414) g, and Hb level at birth was 15.8 (2.6) g/dL. Hb level at birth was significantly associated with all primary outcomes studied (P <0.001) in univariate analyses. Once GA and BWt were adjusted for, only death before discharge remained statistically significant; the OR of death for infants with Hb level at birth <12 g/dL compared with those with Hb level at birth of ≥18 g/dL was 4.1 (95% CI, 1.4–11.6). Hb level at birth was also significantly associated with blood transfusion received (P <0.01) but not with duration of intensive care or neonatal unit days. Conclusions Low Hb level at birth was significantly associated with mortality and receiving blood transfusion in preterm infants born at ≤32 weeks gestation. Further studies are needed to determine the association between Hb level at birth and long-term neurodevelopmental outcomes
The silent HIV epidemic among pregnant women within rural Northern Tanzania
BACKGROUND: Many national antenatal clinics (ANC) based HIV surveillance systems in sub-Saharan Africa have limited coverage of remote rural sites, a weakness that compromises adequate estimation, monitoring and development of effective preventive and care programmes. To address this void in rural Manyara and Singida within Northern Tanzania, we conducted antenatal clinic-based sentinel surveillance. METHODS: We consecutively enrolled 1377 counselled and consenting pregnant women attending ANC clinics for the first time during the current pregnancy. The study was conducted in six antenatal clinics, within three divisions of rural Manyara and Singida regions in 2003/2004. Interviews were conducted and blood samples for routine purposes were collected and tested for anti-HIV IgG antibody anonymously, using Bionor HIV-1 & 2 assay (®). RESULTS: Among enrolees, 94% (1296/1377) participated fully. The overall prevalence of HIV was 2.0% (95%CI: 1.34–2.97). The highest HIV prevalence was among women aged between 15–19 years in both rural and remote rural populations. The odds of HIV infection was 4.3 (95%CI: 1.42–12.77) times among women reporting more than one lifetime sexual partners compared with those with one partner. HIV infection was associated with history of genital sores or foul smelling discharge, OR 6.8 (95%CI: 2.78–16.66) and age at first pregnancy (2.5 times higher likelihood of infection if before the age of 18 years versus at a later age). CONCLUSION: Including rural remote sites, as part of the national ANC routine surveillance, is crucial in order to discover imminent silent epidemics such as the one described in this paper. Scaling up HIV prevention efforts is mandatory to prevent the imminent escalation of the HIV epidemic highly associated with a history of sexually transmitted infections (STIs), multiple sexual partners and pregnancies at a younger age. Ignorance of relevant knowledge and low utilisation of condoms underscores the urgency for large-scale preventive efforts. Research to capture a wider representation of the risk factors in the general population should be a priority to enable further customised HIV prevention efforts
Analysis of stiffness and flexural strength of a reinforced concrete beam using an invented reinforcement system
In this study, we conducted experimental tests on two specimens of reinforced
concrete beams using a three-point bending test to optimize the flexure and stiffness designs. The
first specimen is a reinforced concrete beam with an ordinary reinforcement, and the second
specimen has an invented reinforcement system that consists of an ordinary reinforcement in
addition to three additional bracings using steel bars and steel plates. The results of the flexure test
were collected and analyzed, and the flexural strength, the rate of damage during bending, and the
stiffness were determined. Finite element modeling was applied for both specimens using the LSDYNA program, and the simulation results of the flexure test for the same outputs were
determined. The results of the experimental tests showed that the flexural strength of the invented
reinforcement system was significantly enhanced by 15.5% compared to the ordinary system.
Moreover, the flexural cracks decreased to a significant extent, manifesting extremely small and
narrow cracks in the flexure spread along the bottom face of the concrete. In addition, the
maximum deflection for the invented reinforced concrete beam decreased to 1/3 compared to that
of an ordinary reinforced concrete beam. The results were verified through numerical simulations,
which demonstrated excellent similarities between the flexural failure and the stiffness of the
beam. The invented reinforcement system exhibited a high capability in boosting the flexure
design and stiffness
Publication Bias in Antipsychotic Trials: An Analysis of Efficacy Comparing the Published Literature to the US Food and Drug Administration Database
A comparison of data held by the U.S. Food and Drug Administration (FDA) against data from journal reports of clinical trials enables estimation of the extent of publication bias for antipsychotics
Semaglutide and cardiovascular outcomes in patients with obesity and prevalent heart failure: a prespecified analysis of the SELECT trial
Background: Semaglutide, a GLP-1 receptor agonist, reduces the risk of major adverse cardiovascular events (MACE) in people with overweight or obesity, but the effects of this drug on outcomes in patients with atherosclerotic cardiovascular disease and heart failure are unknown. We report a prespecified analysis of the effect of once-weekly subcutaneous semaglutide 2·4 mg on ischaemic and heart failure cardiovascular outcomes. We aimed to investigate if semaglutide was beneficial in patients with atherosclerotic cardiovascular disease with a history of heart failure compared with placebo; if there was a difference in outcome in patients designated as having heart failure with preserved ejection fraction compared with heart failure with reduced ejection fraction; and if the efficacy and safety of semaglutide in patients with heart failure was related to baseline characteristics or subtype of heart failure. Methods: The SELECT trial was a randomised, double-blind, multicentre, placebo-controlled, event-driven phase 3 trial in 41 countries. Adults aged 45 years and older, with a BMI of 27 kg/m2 or greater and established cardiovascular disease were eligible for the study. Patients were randomly assigned (1:1) with a block size of four using an interactive web response system in a double-blind manner to escalating doses of once-weekly subcutaneous semaglutide over 16 weeks to a target dose of 2·4 mg, or placebo. In a prespecified analysis, we examined the effect of semaglutide compared with placebo in patients with and without a history of heart failure at enrolment, subclassified as heart failure with preserved ejection fraction, heart failure with reduced ejection fraction, or unclassified heart failure. Endpoints comprised MACE (a composite of non-fatal myocardial infarction, non-fatal stroke, and cardiovascular death); a composite heart failure outcome (cardiovascular death or hospitalisation or urgent hospital visit for heart failure); cardiovascular death; and all-cause death. The study is registered with ClinicalTrials.gov, NCT03574597. Findings: Between Oct 31, 2018, and March 31, 2021, 17 604 patients with a mean age of 61·6 years (SD 8·9) and a mean BMI of 33·4 kg/m2 (5·0) were randomly assigned to receive semaglutide (8803 [50·0%] patients) or placebo (8801 [50·0%] patients). 4286 (24·3%) of 17 604 patients had a history of investigator-defined heart failure at enrolment: 2273 (53·0%) of 4286 patients had heart failure with preserved ejection fraction, 1347 (31·4%) had heart failure with reduced ejection fraction, and 666 (15·5%) had unclassified heart failure. Baseline characteristics were similar between patients with and without heart failure. Patients with heart failure had a higher incidence of clinical events. Semaglutide improved all outcome measures in patients with heart failure at random assignment compared with those without heart failure (hazard ratio [HR] 0·72, 95% CI 0·60-0·87 for MACE; 0·79, 0·64-0·98 for the heart failure composite endpoint; 0·76, 0·59-0·97 for cardiovascular death; and 0·81, 0·66-1·00 for all-cause death; all pinteraction>0·19). Treatment with semaglutide resulted in improved outcomes in both the heart failure with reduced ejection fraction (HR 0·65, 95% CI 0·49-0·87 for MACE; 0·79, 0·58-1·08 for the composite heart failure endpoint) and heart failure with preserved ejection fraction groups (0·69, 0·51-0·91 for MACE; 0·75, 0·52-1·07 for the composite heart failure endpoint), although patients with heart failure with reduced ejection fraction had higher absolute event rates than those with heart failure with preserved ejection fraction. For MACE and the heart failure composite, there were no significant differences in benefits across baseline age, sex, BMI, New York Heart Association status, and diuretic use. Serious adverse events were less frequent with semaglutide versus placebo, regardless of heart failure subtype. Interpretation: In patients with atherosclerotic cardiovascular diease and overweight or obesity, treatment with semaglutide 2·4 mg reduced MACE and composite heart failure endpoints compared with placebo in those with and without clinical heart failure, regardless of heart failure subtype. Our findings could facilitate prescribing and result in improved clinical outcomes for this patient group. Funding: Novo Nordisk
Role of CCL3L1-CCR5 Genotypes in the Epidemic Spread of HIV-1 and Evaluation of Vaccine Efficacy
Polymorphisms in CCR5, the major coreceptor for HIV, and CCL3L1, a potent CCR5 ligand and HIV-suppressive chemokine, are determinants of HIV-AIDS susceptibility. Here, we mathematically modeled the potential impact of these genetic factors on the epidemic spread of HIV, as well as on its prevention.Ro, the basic reproductive number, is a fundamental concept in explaining the emergence and persistence of epidemics. By modeling sexual transmission among HIV+/HIV- partner pairs, we find that Ro estimates, and concordantly, the temporal and spatial patterns of HIV outgrowth are highly dependent on the infecting partners' CCL3L1-CCR5 genotype. Ro was least and highest when the infected partner possessed protective and detrimental CCL3L1-CCR5 genotypes, respectively. The modeling data indicate that in populations such as Pygmies with a high CCL3L1 gene dose and protective CCR5 genotypes, the spread of HIV might be minimal. Additionally, Pc, the critical vaccination proportion, an estimate of the fraction of the population that must be vaccinated successfully to eradicate an epidemic was <1 only when the infected partner had a protective CCL3L1-CCR5 genotype. Since in practice Pc cannot be >1, to prevent epidemic spread, population groups defined by specific CCL3L1-CCR5 genotypes might require repeated vaccination, or as our models suggest, a vaccine with an efficacy of >70%. Further, failure to account for CCL3L1-CCR5-based genetic risk might confound estimates of vaccine efficacy. For example, in a modeled trial of 500 subjects, misallocation of CCL3L1-CCR5 genotype of only 25 (5%) subjects between placebo and vaccine arms results in a relative error of approximately 12% from the true vaccine efficacy.CCL3L1-CCR5 genotypes may impact on the dynamics of the HIV epidemic and, consequently, the observed heterogeneous global distribution of HIV infection. As Ro is lowest when the infecting partner has beneficial CCL3L1-CCR5 genotypes, we infer that therapeutic vaccines directed towards reducing the infectivity of the host may play a role in halting epidemic spread. Further, CCL3L1-CCR5 genotype may provide critical guidance for optimizing the design and evaluation of HIV-1 vaccine trials and prevention programs
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