Confirmation of natural gas explosion from methane quantification by headspace gas chromatography-mass spectrometry (HS-GC-MS) in postmortem samples: a case report

A new analytical approach for measuring methane in tissues is presented. For the first time, the use of in situ-produced, stably labelled CDH3 provides a reliable and precise methane quantification. This method was applied to postmortem samples obtained from two victims to help determine the explosion origin. There was evidence of methane in the adipose tissue (82nmol/g) and cardiac blood (1.3nmol/g) of one victim, which corresponded to a lethal methane outburst. These results are discussed in the context of the available literature to define an analysis protocol for application in the event of a gas explosio

Toxicity assessment of refill liquids for electronic cigarettes.

We analyzed 42 models from 14 brands of refill liquids for e-cigarettes for the presence of micro-organisms, diethylene glycol, ethylene glycol, hydrocarbons, ethanol, aldehydes, tobacco-specific nitrosamines, and solvents. All the liquids under scrutiny complied with norms for the absence of yeast, mold, aerobic microbes, Staphylococcus aureus, and Pseudomonas aeruginosa. Diethylene glycol, ethylene glycol and ethanol were detected, but remained within limits authorized for food and pharmaceutical products. Terpenic compounds and aldehydes were found in the products, in particular formaldehyde and acrolein. No sample contained nitrosamines at levels above the limit of detection (1 μg/g). Residual solvents such as 1,3-butadiene, cyclohexane and acetone, to name a few, were found in some products. None of the products under scrutiny were totally exempt of potentially toxic compounds. However, for products other than nicotine, the oral acute toxicity of the e-liquids tested seems to be of minor concern. However, a minority of liquids, especially those with flavorings, showed particularly high ranges of chemicals, causing concerns about their potential toxicity in case of chronic oral exposure

Postoperative bladder dysfunction and outcomes after minimally invasive extravesical ureteric reimplantation in children using a laparoscopic and a robot-assisted approach: results of a multicentre international survey

OBJECTIVES: To assess and compare postoperative bladder dysfunction rates and outcomes after laparoscopic and robot-assisted extravesical ureteric reimplantation in children and to identify risk factors associated with bladder dysfunction. PATIENTS AND METHODS: A total of 151 children underwent minimally invasive extravesical ureteric reimplantation in five international centres of paediatric urology over a 5-year period (January 2013-January 2018). The children were divided in two groups according to surgical approach: group 1 underwent laporoscopic reimplantation and included 116 children (92 girls and 24 boys with a median age of 4.5 years), while group 2 underwent robot-assisted reimplantation and included 35 children (29 girls and six boys with a median age of 7.5 years). The two groups were compared with regard to: procedure length; success rate; postoperative complication rate; and postoperative bladder dysfunction rate (acute urinary retention [AUR] and voiding dysfunction). Univariate and multivariate logistic regression analyses were performed to assess predictors of postoperative bladder dysfunction. Factors assessed included age, gender, laterality, duration of procedure, pre-existing bladder and bowel dysfunction (BBD) and pain control. RESULTS: The mean operating time was significantly longer in group 2 compared with group 1, for both unilateral (159.5 vs 109.5 min) and bilateral procedures (202 vs 132 min; P = 0.001). The success rate was significantly higher in group 2 than in group 1 (100% vs 95.6%; P = 0.001). The overall postoperative bladder dysfunction rate was 8.6% and no significant difference was found between group 1 (6.9%) and group 2 (14.3%; P = 0.17). All AUR cases were managed with short-term bladder catheterization except for two cases (1.3%) in group 1 that required short-term suprapubic catheterization. Univariate and multivariate analyses showed that bilateral pathology, pre-existing BBD and duration of procedure were predictors of postoperative bladder dysfunction (P = 0.001). CONCLUSION: Our results confirmed that short-term bladder dysfunction is a possible complication of extravesical ureteric reimplantation, with no significant difference between the laparoscopic and robot-assisted approaches. Bladder dysfunction occurred more often after bilateral repairs, but required suprapubic catheterization in only 1.3% of cases. Bilaterality, pre-existing BBD and duration of surgery were confirmed on univariate and multivariate analyses as predictors of postoperative bladder dysfunction in this series

Representation of Nelson Algebras by Rough Sets Determined by Quasiorders

In this paper, we show that every quasiorder $R$ induces a Nelson algebra $\mathbb{RS}$ such that the underlying rough set lattice $RS$ is algebraic. We note that $\mathbb{RS}$ is a three-valued {\L}ukasiewicz algebra if and only if $R$ is an equivalence. Our main result says that if $\mathbb{A}$ is a Nelson algebra defined on an algebraic lattice, then there exists a set $U$ and a quasiorder $R$ on $U$ such that $\mathbb{A} \cong \mathbb{RS}$.Comment: 16 page

Drug vaping applied to cannabis: Is "Cannavaping" a therapeutic alternative to marijuana?

Therapeutic cannabis administration is increasingly used in Western countries due to its positive role in several pathologies. Dronabinol or tetrahydrocannabinol (THC) pills, ethanolic cannabis tinctures, oromucosal sprays or table vaporizing devices are available but other cannabinoids forms can be used. Inspired by the illegal practice of dabbing of butane hashish oil (BHO), cannabinoids from cannabis were extracted with butane gas, and the resulting concentrate (BHO) was atomized with specific vaporizing devices. The efficiency of "cannavaping," defined as the "vaping" of liquid refills for e-cigarettes enriched with cannabinoids, including BHO, was studied as an alternative route of administration for therapeutic cannabinoids. The results showed that illegal cannavaping would be subjected to marginal development due to the poor solubility of BHO in commercial liquid refills (especially those with high glycerin content). This prevents the manufacture of liquid refills with high BHO concentrations adopted by most recreational users of cannabis to feel the psychoactive effects more rapidly and extensively. Conversely, "therapeutic cannavaping" could be an efficient route for cannabinoids administration because less concentrated cannabinoids-enriched liquid refills are required. However, the electronic device marketed for therapeutic cannavaping should be carefully designed to minimize potential overheating and contaminant generation

Changes in aroma and sensory profile of food ingredients smoked in the presence of a zeolite filter

During smoking, formation of desirable smoky compounds and carcinogenic polycyclic aromatic hydrocarbons (PAH) are inextricably linked. We have previously developed a zeolite filter technology (PureSmoke Technology or PST) that reduces the PAH content of a smoke stream, particularly reducing the concentration of benzo[a]pyrene, a known carcinogen, by up to 93%. The aim of this work was to determine whether there were changes in the volatile and sensory profiles of ingredients smoked using PST compared to the traditional smoking process (Trad). Smoked tomato flakes (either PST or Trad) were added to either low-fat or full-fat cream cheese for sensory profiling and consumer preference tests, and volatile analysis was carried out using solid phase microextraction (SPME) followed by gas chromatography-mass spectrometry (GC-MS). The sensory analysis showed a significant decrease (p < 0.01) in bitterness when the PST was employed and a significant decrease in overall smoky aroma and flavor (p < 0.001), which resulted in an increase in the perception of cheesy aroma and flavor. This was consistent with a decrease in many of the smoky aroma compounds, particularly the guaiacols. However, consumer preference tests showed that there was no adverse effect on the flavor of the products, and there was even a tendency for the PST product to be preferred to the Trad product (p = 0.096). The smoke compounds were quantitated and compared in smoked tomato paste. Odor activity values (OAVs) calculated from the literature thresholds suggested that guaiacol and 4-alk(en)yl-substituted guaiacols are likely to be among the most highly odor-active compounds in these smoked ingredients

Ballistic Josephson junctions in edge-contacted graphene

Hybrid graphene-superconductor devices have attracted much attention since the early days of graphene research. So far, these studies have been limited to the case of diffusive transport through graphene with poorly defined and modest quality graphene-superconductor interfaces, usually combined with small critical magnetic fields of the superconducting electrodes. Here we report graphene based Josephson junctions with one-dimensional edge contacts of Molybdenum Rhenium. The contacts exhibit a well defined, transparent interface to the graphene, have a critical magnetic field of 8 Tesla at 4 Kelvin and the graphene has a high quality due to its encapsulation in hexagonal boron nitride. This allows us to study and exploit graphene Josephson junctions in a new regime, characterized by ballistic transport. We find that the critical current oscillates with the carrier density due to phase coherent interference of the electrons and holes that carry the supercurrent caused by the formation of a Fabry-P\'{e}rot cavity. Furthermore, relatively large supercurrents are observed over unprecedented long distances of up to 1.5 $\mu$m. Finally, in the quantum Hall regime we observe broken symmetry states while the contacts remain superconducting. These achievements open up new avenues to exploit the Dirac nature of graphene in interaction with the superconducting state.Comment: Updated version after peer review. Includes supplementary material and ancillary file with source code for tight binding simulation

Epithelial-mesenchymal transitions: the importance of changing cell state in development and disease

The events that convert adherent epithelial cells into individual migratory cells that can invade the extracellular matrix are known collectively as epithelial-mesenchymal transition (EMT). Throughout evolution, the capacity of cells to switch between these two cellular states has been fundamental in the generation of complex body patterns. Here, we review the EMT events that build the embryo and further discuss two prototypical processes governed by EMT in amniotes: gastrulation and neural crest formation. Cells undergo EMT to migrate and colonize distant territories. Not surprisingly, this is also the mechanism used by cancer cells to disperse throughout the body

Clinical, radiologic, pathologic, and molecular characteristics of long-term survivors of diffuse intrinsic pontine glioma (DIPG): a collaborative report from the International and European Society for Pediatric Oncology DIPG registries

Purpose Diffuse intrinsic pontine glioma (DIPG) is a brainstem malignancy with a median survival of &lt; 1 year. The International and European Society for Pediatric Oncology DIPG Registries collaborated to compare clinical, radiologic, and histomolecular characteristics between short-term survivors (STSs) and long-term survivors (LTSs). Materials and Methods Data abstracted from registry databases included patients from North America, Australia, Germany, Austria, Switzerland, the Netherlands, Italy, France, the United Kingdom, and Croatia. Results Among 1,130 pediatric and young adults with radiographically confirmed DIPG, 122 (11%) were excluded. Of the 1,008 remaining patients, 101 (10%) were LTSs (survival ≥ 2 years). Median survival time was 11 months (interquartile range, 7.5 to 16 months), and 1-, 2-, 3-, 4-, and 5-year survival rates were 42.3% (95% CI, 38.1% to 44.1%), 9.6% (95% CI, 7.8% to 11.3%), 4.3% (95% CI, 3.2% to 5.8%), 3.2% (95% CI, 2.4% to 4.6%), and 2.2% (95% CI, 1.4% to 3.4%), respectively. LTSs, compared with STSs, more commonly presented at age &lt; 3 or &gt; 10 years (11% v 3% and 33% v 23%, respectively; P &lt; .001) and with longer symptom duration ( P &lt; .001). STSs, compared with LTSs, more commonly presented with cranial nerve palsy (83% v 73%, respectively; P = .008), ring enhancement (38% v 23%, respectively; P = .007), necrosis (42% v 26%, respectively; P = .009), and extrapontine extension (92% v 86%, respectively; P = .04). LTSs more commonly received systemic therapy at diagnosis (88% v 75% for STSs; P = .005). Biopsies and autopsies were performed in 299 patients (30%) and 77 patients (10%), respectively; 181 tumors (48%) were molecularly characterized. LTSs were more likely to harbor a HIST1H3B mutation (odds ratio, 1.28; 95% CI, 1.1 to 1.5; P = .002). Conclusion We report clinical, radiologic, and molecular factors that correlate with survival in children and young adults with DIPG, which are important for risk stratification in future clinical trials