Silica Nanochannel Array Film Supported by ß-Cyclodextrin-Functionalized Graphene Modified Gold Film Electrode for Sensitive and Direct Electroanalysis of Acetaminophen

Convenient and sensitive detection of active analytes in complex matrix is crucial in biological, medical, and environmental analysis. Silica nanochannel array film (SNF) equipped electrochemical sensors have shown excellent anti-fouling performance in direct analysis of complex samples. In this work, we demonstrated an electrochemical sensor with anti-fouling performance for highly sensitive detection of acetaminophen (APAP) based on SNF supported by ß-cyclodextrin-graphene (CDG) nanocomposite modified Au film electrode (AuF). Because of their rich surface hydroxyls and 2D lamellar structure, CDG on AuF can serve as the nanoadhesive for compact binding SNF, which can be grown by electrochemical assisted self-assembly method in a few seconds. Attributable to the electrocatalytic property of graphene and the synergistic enrichment from both CD and SNF nanochannels towards analyte, the SNF/CDG/AuF sensor demonstrates sensitive detection of acetaminophen ranged from 0.2 to 50 μM with an ultralow limit-of-detection of 14 nM. Taking advantage of the anti-fouling ability of SNF, the sensor is able to realize accurate and convenient analysis of APAP in commercially available paracetamol tablets.

Direct in vivo Analysis of CBD- and THC-Acid Type Cannabinoids and Classification of Cannabis Cultivars by SpiderMass

In the recent years, Cannabis and hemp-based products have become increasingly popular for various applications ranging from recreational use, edibles, beverages to health care products and medicines. The rapid detection and differentiation of phytocannabinoids is, therefore, essential to assess the potency, therapeutic and nutritional values of cannabis cultivars. Here, we implemented the SpiderMass technology for the in vivo detection of cannabidiol acid (CBDA) and tetrahydrocannabinol acid (THCA) and other endogenous organic plant compounds to access distribution gradients within the plants and differentiate cultivars. The SpiderMass system is composed of an IR- laser handheld microsampling probe connected to the mass spectrometer through a transfer tube. The analysis was performed in situ on different plant organs from freshly cultivated Cannabis plants in only a few seconds. SpiderMass analysis easily discriminated the two acid phytocannabinoid isomers by MS/MS and the built statistical models differentiated between four Cannabis cultivars. Different abundancies of acid phytocannabinoids were also found along the plant as well as between different cultivars. All together, these results introduce the direct analysis by SpiderMass as a compelling analytical alternative for forensic and hemp industrial analysis.

Bacteremia caused by Helicobacter cinaedi: a case report

Objectives Helicobacter cinaedi is a Gram-negative, spiral-shaped bacterium that primarily affects immunosuppressed patients. Case presentation A 49-year-old patient with ulcerative colitis diagnosed in 1992, who presented to the ED of our hospital with fever and testicular complaints. The patient was discharged with a diagnosis of left-sided acute epididymitis, which was probably sexually transmitted. At the ED, he was administered intravenous Ceftriaxone and discharged with a prescription of doxycycline for 10 days, with a good progress. Aerobic cultures were positive at three days from collection. Gram staining showed Gram-negative, corkscrew-shaped bacteria. The analysis of the blood culture bottles, and the colonies grown in Campylosel agar incubated in microaerophilic conditions at 42 °C were identified as H. cinaedi on the Maldi-TOF Biotyper 3.0 system (Bruker Diagnostics Inc.). Conclusions Direct analysis of the blood culture bottle on the Maldi-TOF system allowed for the identification of the etiology of the bacteremia since H. cinaedi could not have been grown in standard culture conditions. The treatment of this infection is a matter of debate; however, the combination of ceftriaxone with doxycycline can be ineffective for bacteremia caused by H. cinaedi infection since it occurs by the translocation of the bacteria from the gastrointestinal tract. This type of bacteremia is associated with intestinal mucosal damage secondary to ulcerative colitis, and it primarily affects immunosuppressed patients.

Dynamics of exposure to mercury in a population of the upper Madeira River, Rondônia – Brazil

This work evaluates the influence of cognitive and sociodemographic functions on the dynamics of human exposure to mercury in communities on the upper Madeira River in the state of Rondônia, Brazil. In this longitudinal epidemiological study of convenience sampling (2009 to 2019), semi-structured questionnaires on cognitive and sociodemographic aspects were applied to 1,089 participants (646 men and 443 women) divided into 6 groups with distinct geographic characteristics and lifestyles. Total mercury concentrations in hair samples were determined by direct analysis using atomic spectroscopy. In this population, cognitive (memory, attention span, concentration and difficulties in reading, writing and mathematical calculations) and sociodemographic (location, gender, age, education, alcohol consumption, smoking habits, time of residence in the region, occupation) grouping showed the differentiation between the groups with lifestyle directly related and dependent on extractivism/gold mining dispersed along the Madeira River (G1 and G2), and the groups that have urban dynamics on the margins of the federal highway BR-364 (G3, G4, G5 and G6). Sex, age and lifestyle (groups) were significant indicators of total mercury concentrations in hair. The organization of participants according to cognitive and sociodemographic profiles, regardless of geographic location, highlights the contribution of individualized social dynamics to mercury exposure in the Madeira River basin region. Despite socio-historical and socio-economic similarities, cognitive and sociodemographic functions show individualized social behaviors within communities, which may influence the process of exposure to THg.

ANALYSIS OF THE STRESS-STRAIN STATE OF AN ASYNCHRONOUS MOTOR WITH A SHORT-CIRCUITED ROTOR UNDER AXIAL LOADS

A comparative description of the most popular and professional 3D modeling packages using the finite element method in solving problems is given. The choice of using the SolidWorks Simulation package at this stage of research is justified. Its main advantages are given. A 3D model of a real functioning asynchronous motor has been designed and modified to perform linear displacement operations. A static analysis of the strength of an asynchronous motor with linear displacement of the actuator using the plug-in module SolidWorks Simulation was performed. A direct analysis of the obtained result of the stress-strain state of the engine is carried out. Conclusions are drawn about its suitability to work with axial loads. The main directions of subsequent research of asynchronous motors with a short-circuited rotor under axial loads are determined.

Volatile Organic Compound Profile Fingerprints Using DART–MS Shows Species-Specific Patterns in Fusarium Mycotoxin Producing Fungi

Fungal volatile organic compounds (VOCs) are low-molecular weight fungal metabolites that have high vapor pressure at ambient temperatures and can function as airborne signals. Here, we report a VOC study of several different species of Fusarium. Direct analysis in real time mass spectrometry (DART–MS) was applied for non-invasive VOC fingerprinting of Fusarium isolates growing under standardized conditions. A large number of ions were detected from the headspaces of the Fusarium species sampled here. Ions were detected with distinctively high concentrations in some species. While there were few VOCs produced by only one species, the relative concentrations of VOCs differed between species. The methodology has potential for convenient detection and identification of Fusarium contamination in agricultural commodities.