Arterial Tortuosity: An Imaging Biomarker of Childhood Stroke Pathogenesis?

Background and purposeArteriopathy is the leading cause of childhood arterial ischemic stroke. Mechanisms are poorly understood but may include inherent abnormalities of arterial structure. Extracranial dissection is associated with connective tissue disorders in adult stroke. Focal cerebral arteriopathy is a common syndrome where pathophysiology is unknown but may include intracranial dissection or transient cerebral arteriopathy. We aimed to quantify cerebral arterial tortuosity in childhood arterial ischemic stroke, hypothesizing increased tortuosity in dissection.MethodsChildren (1 month to 18 years) with arterial ischemic stroke were recruited within the Vascular Effects of Infection in Pediatric Stroke (VIPS) study with controls from the Calgary Pediatric Stroke Program. Objective, multi-investigator review defined diagnostic categories. A validated imaging software method calculated the mean arterial tortuosity of the major cerebral arteries using 3-dimensional time-of-flight magnetic resonance angiographic source images. Tortuosity of unaffected vessels was compared between children with dissection, transient cerebral arteriopathy, meningitis, moyamoya, cardioembolic strokes, and controls (ANOVA and post hoc Tukey). Trauma-related versus spontaneous dissection was compared (Student t test).ResultsOne hundred fifteen children were studied (median, 6.8 years; 43% women). Age and sex were similar across groups. Tortuosity means and variances were consistent with validation studies. Tortuosity in controls (1.346±0.074; n=15) was comparable with moyamoya (1.324±0.038; n=15; P=0.998), meningitis (1.348±0.052; n=11; P=0.989), and cardioembolic (1.379±0.056; n=27; P=0.190) cases. Tortuosity was higher in both extracranial dissection (1.404±0.084; n=22; P=0.021) and transient cerebral arteriopathy (1.390±0.040; n=27; P=0.001) children. Tortuosity was not different between traumatic versus spontaneous dissections (P=0.70).ConclusionsIn children with dissection and transient cerebral arteriopathy, cerebral arteries demonstrate increased tortuosity. Quantified arterial tortuosity may represent a clinically relevant imaging biomarker of vascular biology in pediatric stroke

Analysis of the Impact of Propanol-Gasoline Blends on Lubricant Oil Degradation and Spark-Ignition Engine Characteristics

Alcoholic fuels have recently come to light as a sustainable source for powering today’s vehicles. Various studies have investigated the effects of alcoholic fuels on engine efficiency and emission characteristics. However, scarce literature is available for their effects on lubricant. Therefore, propanol-gasoline fuel mixtures, with concentrations of 9% (P9) and 18% (P18) propanol, were made to compare their engine characteristics and lubricating oil condition with that of pure gasoline (0 percent propanol (P0)). To determine the rate of deterioration, the characteristics of the lubricating oil were evaluated after 100 h of engine operation, as suggested by the manufacturer. When compared with unused lube oil, P18 showed reductions in flash point temperature and kinematic viscosity of 14% and 36%, respectively, at 100 °C. For P18, which contains Fe (27 PPM), Al (11 PPM), and Cu (14 PPM), the highest wear element concentrations in the lubricating oil were found. The moisture in the degraded oil was well within the allowable limit for the three fuel mixtures. With the increase in propanol percentage in the propanol-gasoline blend, the engine performance was increased. Compared to P9 and P0, P18 had the partially unburned emissions

Population‐based cohort study of outcomes following cholecystectomy for benign gallbladder diseases

Background The aim was to describe the management of benign gallbladder disease and identify characteristics associated with all‐cause 30‐day readmissions and complications in a prospective population‐based cohort. Methods Data were collected on consecutive patients undergoing cholecystectomy in acute UK and Irish hospitals between 1 March and 1 May 2014. Potential explanatory variables influencing all‐cause 30‐day readmissions and complications were analysed by means of multilevel, multivariable logistic regression modelling using a two‐level hierarchical structure with patients (level 1) nested within hospitals (level 2). Results Data were collected on 8909 patients undergoing cholecystectomy from 167 hospitals. Some 1451 cholecystectomies (16·3 per cent) were performed as an emergency, 4165 (46·8 per cent) as elective operations, and 3293 patients (37·0 per cent) had had at least one previous emergency admission, but had surgery on a delayed basis. The readmission and complication rates at 30 days were 7·1 per cent (633 of 8909) and 10·8 per cent (962 of 8909) respectively. Both readmissions and complications were independently associated with increasing ASA fitness grade, duration of surgery, and increasing numbers of emergency admissions with gallbladder disease before cholecystectomy. No identifiable hospital characteristics were linked to readmissions and complications. Conclusion Readmissions and complications following cholecystectomy are common and associated with patient and disease characteristics

Laparoscopy in management of appendicitis in high-, middle-, and low-income countries: a multicenter, prospective, cohort study.

BACKGROUND: Appendicitis is the most common abdominal surgical emergency worldwide. Differences between high- and low-income settings in the availability of laparoscopic appendectomy, alternative management choices, and outcomes are poorly described. The aim was to identify variation in surgical management and outcomes of appendicitis within low-, middle-, and high-Human Development Index (HDI) countries worldwide. METHODS: This is a multicenter, international prospective cohort study. Consecutive sampling of patients undergoing emergency appendectomy over 6 months was conducted. Follow-up lasted 30 days. RESULTS: 4546 patients from 52 countries underwent appendectomy (2499 high-, 1540 middle-, and 507 low-HDI groups). Surgical site infection (SSI) rates were higher in low-HDI (OR 2.57, 95% CI 1.33-4.99, p = 0.005) but not middle-HDI countries (OR 1.38, 95% CI 0.76-2.52, p = 0.291), compared with high-HDI countries after adjustment. A laparoscopic approach was common in high-HDI countries (1693/2499, 67.7%), but infrequent in low-HDI (41/507, 8.1%) and middle-HDI (132/1540, 8.6%) groups. After accounting for case-mix, laparoscopy was still associated with fewer overall complications (OR 0.55, 95% CI 0.42-0.71, p < 0.001) and SSIs (OR 0.22, 95% CI 0.14-0.33, p < 0.001). In propensity-score matched groups within low-/middle-HDI countries, laparoscopy was still associated with fewer overall complications (OR 0.23 95% CI 0.11-0.44) and SSI (OR 0.21 95% CI 0.09-0.45). CONCLUSION: A laparoscopic approach is associated with better outcomes and availability appears to differ by country HDI. Despite the profound clinical, operational, and financial barriers to its widespread introduction, laparoscopy could significantly improve outcomes for patients in low-resource environments. TRIAL REGISTRATION: NCT02179112

Opportunities and Challenges for Renewable Energy Utilization in Pakistan

Pakistan is a developing country that faces severe energy crises due to the increased use of energy. The purpose of this study is energy transition by designing a strategy for the adoption of renewable energy policies in the entire energy system by using all renewable energy resources to forecast future energy needs and carbon emission mitigation potential. This research study aims to evaluate the renewable energy policies of Pakistan and to analyze the ways to secure energy sources in the future using LEAP. The study established a path for the transformation of the Pakistan energy system by considering the potential of renewable resources, the cost of the energy system, and the primary energy supply. The highest value of energy demand is noted for the 1st scenario, while the lowest emissions are noted for the 16th scenario for each renewable source (WIN16, SOL16, and BIO16). The lowest values of energy demand and emissions (192.1 TWh and 37.7 MMT, respectively) are shown using the green solution compared to other scenarios (hydro, nuclear, BAU), concluding that the green solution is the most suitable scenario. The analysis shows, that from a technological and economic perspective, it is possible to carry out transformation with the necessary steps to effectively achieve a renewable energy system. The findings of this study show that the green scenario in Pakistan which has the lowest operational and externality costs is the best choice for the future

Heat transfer and pressure drop characteristics of ZnO/DIW based nanofluids in small diameter compact channels: An experimental study

This experimental study is focused on heat transfer performance and pressure drop characteristics of ZnO/DIW-based nanofluids (NFs) in horizontal mini tubes of different (1.0-2.0 mm) diameters. Different mass concentrations (0.012-0.048 wt %) of nanoparticles (NPs) were tested with varying fluid flow rates (12-24 ml/min) of NFs. The thermal conductivity (TC) and viscosity (VC) of stable NFs were tested at 20-60 °C, at a fixed temperature (40 °C), and concentration of NPs (0.048 wt%) the maximum rise was 18.27% and 20.31%, respectively. The local and average heat transfer coefficients (HTCs) and the pressure gradient were noticed to be directly proportional to volume flow rate of NFs and the mass concentration of NPs. However, an inverse trend was noticed with the test section's diameter. At 0.048 wt % of NPs and 24.0 ml/min flow rate of NFs, the maximum rise in local and average HTCs and pressure gradient was 17.11-11.61% and 13.05-9.79%, and 29.19-12.25%, respectively, in a tube's diameter of 1.0-2.0 mm. The friction factor increased with NP's loading while the same reduced with the fluid flow rate. The corresponding maximum change in the friction factor was 28.85-12.72% for the tubes with 1.0-2.0 mm diameters, respectively, at a 12.0 ml/min flow rate of NFs. The comparison of experimental findings for the HTCs, pressure gradients and friction factors with the standard Shah and Darcy's correlations showed that the observations are in good agreement with the predicted ones

Hepatotoxicity induced by horse ATG and reversed by rabbit ATG: a case report

<p>Abstract</p> <p>Background</p> <p>The use of antilymphocyte agents has improved patient and graft survival in hematopoietic stem cell and solid organ transplantation but has been associated with the development of short-term toxicities as well as long-term complications.</p> <p>Case presentation</p> <p>We report a young female with Fanconi anemia who received antithymocyte globulin as part of the conditioning regimen prior to her planned allogeneic hematopoietic stem cell transplant at King Faisal Specialist Hospital and Research Centre in Riyadh. She developed sudden and severe hepatotoxicity after receiving the first dose of horse antithymocyte globulin, manifested by marked elevation of serum transaminases and mild elevation of serum bilirubin level. Immediately after withdrawal of the offending agent and shifting to the rabbit form of antithymocyte globulin, the gross liver dysfunction started to subside and the hepatic profile results returned to the pre-transplant levels few weeks later. The patient had her allogeneic hematopoietic stem cell transplant as planned without any further hepatic complications. After having a successful allograft, she was discharged from the stem cell transplant unit. During her follow up at the outpatient clinic, the patient remained very well and no major complication was encountered.</p> <p>Conclusion</p> <p>Hepatotoxicity related to the utilization of antithymocyte globulin varies considerably in severity and may be transient or long standing. There may be individual or population based susceptibilities to the development of side effects and these adverse reactions may also vary with the choice of the agent used. Encountering adverse effects with one type of antithymocyte agents should not discourage clinicians from shifting to another type in situations where continuation of the drug is vital.</p

Utilizing Risk Scores in Determining the Optimal Revascularization Strategy for Complex Coronary Artery Disease

Percutaneous coronary intervention (PCI) of multivessel and/or left main stem disease have been shown to be potentially legitimate revascularization alternatives in appropriately selected patients. Risk stratification is an important component in guiding patients to identify the most appropriate revascularization modality (PCI or coronary artery bypass grafting [CABG]) in conjunction with the Heart Team. The aim of this paper is to give the clinician a concise overview of the important established and evolving contemporary risk models in aiding this decision-making process. Risk models, based on clinical and anatomical variables alone, the novel concept of functional anatomical risk scores, and risk models combining aspects from both clinical and anatomical scores, are all discussed. The emerging concepts of the patient-empowered risk/benefit tradeoff between PCI and CABG to help personalize the choice of revascularization modality are also explored