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•Biodiesel–n-butanol blends were tested in a diesel engine for blends up to 40% n-butanol.•Exhaust gas emissions and PAHs were extensively determined and analyzed.•Most of the PAHs ...were emitted as semi-volatile compounds and not bound to particulate matter.•Blending more than 20% n-butanol with biodiesel also increased the toxicity of PAH emission.
Polycyclic aromatic hydrocarbons (PAHs), described as unregulated emissions, are harmful to the environment, human health and engines, and need to be controlled and reduced. Two of the most common alternative fuel types are biodiesel and alcohols, and their effects on PAH formation are not well-known, currently. Since biodiesel (B) fuels do not contain aromatic components and are suitable for use in diesel engines, the use of biodiesel as the base fuel for studying the effect of n-butanol (Bu) on PAH formation is natural.
With this purpose in mind, waste oil methyl ester, which is a compatible alternative fuel with diesel engines, was blended with 10%, 20% and 40% of n-butanol by volume, and BBu10, BBu20 and BBu40 blends were created. After determining fuel properties, these blends were tested in an ONAN diesel generator under four engine loads at 1800rpm to quantify PAHs and to determined engine performance characteristics and regulated emissions. Separately, in order to quantify PAHs under the same engine conditions, GC–MS PAH speciation method was applied to real samples obtained from the engine. Cold flow properties were improved by adding n-butanol to biodiesel. For PAHs, it was shown that most of the aromatic hydrocarbons were emitted as semi-volatile compounds and were not bound to particulate matter. Blending more than 20% n-butanol into biodiesel also increased the toxicity of PAHs. No significant change in the aromaticity of the PAH emissions was found between blends.
To increase the use of biofuels in diesel engines and reduce harmful emissions emitted from diesel fuel, biodiesel and higher alcohols are fuel sources at the forefront of research. The aim of this ...study is to understand the effect of water-containing n-butanol-biodiesel blends on regulated emissions, emphasizing nitrogen oxides (NOx) and polycyclic aromatic hydrocarbons (PAHs), which are harmful for the environment and engine durability. 10% n-butanol (B90Bu10) and 10% n-butanol-1% water (B89Bu10W1) were blended with 89% waste-oil biodiesel and tested in a diesel engine at four engine loads at a constant engine speed. PAH samples were analyzed using gas chromatography-mass spectrometry (GC-MS). Results showed B100, B90Bu10 and B89Bu10W1 blends increased break specific fuel consumption (BSFC), exhaust gas temperatures (EGT), carbon monoxide (CO) and hydrocarbon (HC) emissions. However, NOx emissions significantly decreased using butanol and butanol-water blends. Compared to diesel, biodiesel and blended fuels significantly reduced total PAHs and PAH toxicity up to 75.0%. However, B89Bu10W1 increased total PAH and PAH toxicity by 35.7%. Overall, the biodiesel-butanol blend, which emits less carcinogenic pollutants and low-cyclic PAHs than water-containing fuel, was found to reduce the risk of wetstacking in diesel engines operating under low loads.
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•Aromatic-free fuels were tested for regulated and unregulated emissions (PAHs).•Blending 10% n-butanol and 10% n-butanol-1% water with biodiesel decreased NOx.•Water addition increased total PAHs and toxicity as compared to B100 and B90Bu10.•Biodiesel-n-butanol blend reduced wetstacking risks in diesel engines at idle.
Summary Background In 2015, five randomised trials showed efficacy of endovascular thrombectomy over standard medical care in patients with acute ischaemic stroke caused by occlusion of arteries of ...the proximal anterior circulation. In this meta-analysis we, the trial investigators, aimed to pool individual patient data from these trials to address remaining questions about whether the therapy is efficacious across the diverse populations included. Methods We formed the HERMES collaboration to pool patient-level data from five trials (MR CLEAN, ESCAPE, REVASCAT, SWIFT PRIME, and EXTEND IA) done between December, 2010, and December, 2014. In these trials, patients with acute ischaemic stroke caused by occlusion of the proximal anterior artery circulation were randomly assigned to receive either endovascular thrombectomy within 12 h of symptom onset or standard care (control), with a primary outcome of reduced disability on the modified Rankin Scale (mRS) at 90 days. By direct access to the study databases, we extracted individual patient data that we used to assess the primary outcome of reduced disability on mRS at 90 days in the pooled population and examine heterogeneity of this treatment effect across prespecified subgroups. To account for between-trial variance we used mixed-effects modelling with random effects for parameters of interest. We then used mixed-effects ordinal logistic regression models to calculate common odds ratios (cOR) for the primary outcome in the whole population (shift analysis) and in subgroups after adjustment for age, sex, baseline stroke severity (National Institutes of Health Stroke Scale score), site of occlusion (internal carotid artery vs M1 segment of middle cerebral artery vs M2 segment of middle cerebral artery), intravenous alteplase (yes vs no), baseline Alberta Stroke Program Early CT score, and time from stroke onset to randomisation. Findings We analysed individual data for 1287 patients (634 assigned to endovascular thrombectomy, 653 assigned to control). Endovascular thrombectomy led to significantly reduced disability at 90 days compared with control (adjusted cOR 2·49, 95% CI 1·76–3·53; p<0·0001). The number needed to treat with endovascular thrombectomy to reduce disability by at least one level on mRS for one patient was 2·6. Subgroup analysis of the primary endpoint showed no heterogeneity of treatment effect across prespecified subgroups for reduced disability (pinteraction =0·43). Effect sizes favouring endovascular thrombectomy over control were present in several strata of special interest, including in patients aged 80 years or older (cOR 3·68, 95% CI 1·95–6·92), those randomised more than 300 min after symptom onset (1·76, 1·05–2·97), and those not eligible for intravenous alteplase (2·43, 1·30–4·55). Mortality at 90 days and risk of parenchymal haematoma and symptomatic intracranial haemorrhage did not differ between populations. Interpretation Endovascular thrombectomy is of benefit to most patients with acute ischaemic stroke caused by occlusion of the proximal anterior circulation, irrespective of patient characteristics or geographical location. These findings will have global implications on structuring systems of care to provide timely treatment to patients with acute ischaemic stroke due to large vessel occlusion. Funding Medtronic.
High-fidelity intracranial electrode arrays for recording and stimulating brain activity have facilitated major advances in the treatment of neurological conditions over the past decade. Traditional ...arrays require direct implantation into the brain via open craniotomy, which can lead to inflammatory tissue responses, necessitating development of minimally invasive approaches that avoid brain trauma. Here we demonstrate the feasibility of chronically recording brain activity from within a vein using a passive stent-electrode recording array (stentrode). We achieved implantation into a superficial cortical vein overlying the motor cortex via catheter angiography and demonstrate neural recordings in freely moving sheep for up to 190 d. Spectral content and bandwidth of vascular electrocorticography were comparable to those of recordings from epidural surface arrays. Venous internal lumen patency was maintained for the duration of implantation. Stentrodes may have wide ranging applications as a neural interface for treatment of a range of neurological conditions.
•Biodiesel–butanol blends as a function of butanol concentration are tested and compared to standard diesel fuel.•Exhaust gas emissions are reported.•Advantages and disadvantages of butanol as an ...additive are discussed.
The purpose of this work is to investigate the effect of butanol–biodiesel blends on the emissions and performance characteristics of a four-stroke, naturally aspirated, water-cooled, indirect injection diesel engine (IDI). Testing was performed comparing butanol blended with biodiesel, standard diesel (D100) and neat biodiesel (B100) at four engine loads. The biodiesel–butanol blends were 5%, 10%, and 20% butanol in volume basis (B95Bu5, B90Bu10, B80Bu20). Compared to biodiesel, butanol blended fuels showed lower exhaust gas temperatures and nitrogen oxides (NOx) emissions while exhibiting higher carbon monoxide (CO) and unburned hydrocarbons (HC) emissions. Butanol blended fuels produced lower CO and higher NOx emissions than diesel fuel for low concentrations of butanol (5% and 10%), but there was no significant change in terms of HC emissions. The biodiesel blend containing the highest concentration of butanol (20%) caused higher CO and HC emissions and lower NOx emission than diesel. Brake specific fuel consumption increased with biodiesel and biodiesel blended fuels as compared to diesel.
Cellular diversity in tumors is a key factor for therapeutic failures and lethal outcomes of solid malignancies. Here, we determined the single-cell transcriptomic landscape of liver cancer ...biospecimens from 19 patients. We found varying degrees of heterogeneity in malignant cells within and between tumors and diverse landscapes of tumor microenvironment (TME). Strikingly, tumors with higher transcriptomic diversity were associated with patient's worse overall survival. We found a link between hypoxia-dependent vascular endothelial growth factor expression in tumor diversity and TME polarization. Moreover, T cells from higher heterogeneous tumors showed lower cytolytic activities. Consistent results were found using bulk genomic and transcriptomic profiles of 765 liver tumors. Our results offer insight into the diverse ecosystem of liver cancer and its impact on patient prognosis.
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•HCC and iCCA have a varying degree of transcriptomic diversity•Tumor transcriptomic diversity is associated with patient outcomes•Tumor-derived VEGF drives microenvironmental reprogramming•T cells derived from higher heterogeneous tumors showed lower cytolytic activities
Ma et al. perform single-cell RNA sequencing of primary liver cancers and find heterogeneity in malignant cells and in the tumor microenvironment, the degree of which negatively associates with patient prognosis. They demonstrate that VEGF expression is linked to tumor diversity and T cell dysfunction.
In patients with ischemic stroke and a proximal cerebral arterial occlusion and salvageable tissue on imaging, alteplase followed by thrombectomy with a stent retriever was more effective than ...alteplase alone in improving reperfusion, neurologic recovery, and functional outcome.
The results of the Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands (MR CLEAN) trial,
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which showed reduced disability among patients with ischemic stroke who were treated with endovascular thrombectomy in addition to standard care, represent an advance in stroke care. The MR CLEAN study followed several trials that had neutral findings with respect to the use of endovascular thrombectomy.
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In the largest of these trials, the Interventional Management of Stroke 3 (IMS-3) study, investigators compared the administration of 0.9 mg of alteplase per kilogram of body weight to a bridging strategy of . . .
Distinguishing between stroke subtypes and knowing the time of stroke onset are critical in clinical practice. Thrombolysis and thrombectomy are very effective treatments in selected patients with ...acute ischemic stroke. Neuroimaging helps decide who should be treated and how they should be treated but is expensive, not always available and can have contraindications. These limitations contribute to the under use of these reperfusion therapies.
An alternative approach in acute stroke diagnosis is to identify blood biomarkers which reflect the body's response to the damage caused by the different types of stroke. Specific blood biomarkers capable of differentiating ischemic from hemorrhagic stroke and mimics, identifying large vessel occlusion and capable of predicting stroke onset time would expedite diagnosis and increase eligibility for reperfusion therapies.
To date, measurements of candidate biomarkers have usually occurred beyond the time window for thrombolysis. Nevertheless, some candidate markers of brain tissue damage, particularly the highly abundant glial structural proteins like GFAP and S100β and the matrix protein MMP-9 offer promising results. Grouping of biomarkers in panels can offer additional specificity and sensitivity for ischemic stroke diagnosis. Unbiased "omics" approaches have great potential for biomarker identification because of greater gene, protein, and metabolite coverage but seem unlikely to be the detection methodology of choice because of their inherent cost.
To date, despite the evolution of the techniques used in their evaluation, no individual candidate or multimarker panel has proven to have adequate performance for use in an acute clinical setting where decisions about an individual patient are being made. Timing of biomarker measurement, particularly early when decision making is most important, requires urgent and systematic study.
Background Unintentional poisoning deaths have been increasing dramatically over the past decade, and the majority of this increase has resulted from overdoses of specific prescription drugs. Despite ...this trend, there are limited existing data examining hospitalizations for poisonings, both unintentional and intentional, associated with prescription drugs. A better understanding of these hospitalizations may help identify high-risk populations in need of intervention to prevent subsequent mortality. Purpose This article aims to describe the incidence and characteristics of hospitalizations resulting from poisoning by prescription opioids, sedatives, and tranquilizers in the U.S. from 1999 to 2006 and make comparisons to hospitalizations for all other poisonings during this time period. Methods Hospitalizations for poisonings were selected from the Nationwide Inpatient Sample (NIS), a stratified, representative sample of approximately 8 million hospitalizations each year, according to the principal discharge diagnosis. Intentionality of the poisoning was determined by external cause of injury codes. SAS callable SUDAAN software was used to calculate weighted estimates of poisoning hospitalizations by type and intentionality. Demographic and clinical characteristics of poisoning cohorts were compared. Data were analyzed in 2009. Results From 1999 to 2006, U.S. hospitalizations for poisoning by prescription opioids, sedatives, and tranquilizers increased a total of 65%. This increase was double the increase observed in hospitalizations for poisoning by other drugs and substances. The largest increase in the number of hospitalized cases over the 7-year period was seen for poisonings by benzodiazepines, whereas the largest percentage increase was observed for methadone (400%). In comparison to patients hospitalized for poisoning from other substances, those hospitalized for prescription opioids, sedatives, and tranquilizers were more likely to be women, aged >34 years, and to present to a rural or urban nonteaching hospital. Conclusions Prescription opioids, sedatives, and tranquilizers are an increasing cause of hospitalization. The hospital admission provides an opportunity to better understand the contextual factors contributing to these cases, which may aid in the development of targeted prevention strategies.
Summary Background Results of initial randomised trials of endovascular treatment for ischaemic stroke, published in 2013, were neutral but limited by the selection criteria used, early-generation ...devices with modest efficacy, non-consecutive enrolment, and treatment delays. Recent developments In the past year, six positive trials of endovascular thrombectomy for ischaemic stroke have provided level 1 evidence for improved patient outcome compared with standard care. In most patients, thrombectomy was performed in addition to thrombolysis with intravenous alteplase, but benefits were also reported in patients ineligible for alteplase treatment. Despite differences in the details of eligibility requirements, all these trials required proof of major vessel occlusion on non-invasive imaging and most used some imaging technique to exclude patients with a large area of irreversibly injured brain tissue. The results indicate that modern thrombectomy devices achieve faster and more complete reperfusion than do older devices, leading to improved clinical outcomes compared with intravenous alteplase alone. The number needed to treat to achieve one additional patient with independent functional outcome was in the range of 3·2–7·1 and, in most patients, was in addition to the substantial efficacy of intravenous alteplase. No major safety concerns were noted, with low rates of procedural complications and no increase in symptomatic intracerebral haemorrhage. Where next? Thrombectomy benefits patients across a range of ages and levels of clinical severity. A planned meta-analysis of individual patient data might clarify effects in under-represented subgroups, such as those with mild initial stroke severity or elderly patients. Imaging-based selection, used in some of the recent trials to exclude patients with large areas of irreversible brain injury, probably contributed to the proportion of patients with favourable outcomes. The challenge is how best to implement imaging in clinical practice to maximise benefit for the entire population and to avoid exclusion of patients with smaller yet clinically important potential to benefit. Although favourable imaging identifies patients who might benefit despite long delays from symptom onset to treatment, the proportion of patients with favourable imaging decreases with time. Health systems therefore need to be reorganised to deliver treatment as quickly as possible to maximise benefits. On the basis of available trial data, intravenous alteplase remains the initial treatment for all eligible patients within 4·5 h of stroke symptom onset. Those patients with major vessel occlusion should, in parallel, proceed to endovascular thrombectomy immediately rather than waiting for an assessment of response to alteplase, because minimising time to reperfusion is the ultimate aim of treatment.
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