Spike by spike frequency analysis of amperometry traces provides statistical validation of observations in the time domain.

Amperometry is a commonly used electrochemical method for studying the process of exocytosis in real-time. Given the high precision of recording that amperometry procedures offer, the volume of data generated can span over several hundreds of megabytes to a few gigabytes and therefore necessitates systematic and reproducible methods for analysis. Though the spike characteristics of amperometry traces in the time domain hold information about the dynamics of exocytosis, these biochemical signals are, more often than not, characterized by time-varying signal properties.

Applying machine learning to international drug monitoring: classifying cannabis resin collected in Europe using cannabinoid concentrations.

In Europe, concentrations of ∆-tetrahydrocannabinol (THC) in cannabis resin (also known as hash) have risen markedly in the past decade, potentially increasing risks of mental health disorders. Current approaches to international drug monitoring cannot distinguish between different types of cannabis resin which may have contrasting health effects due to THC and cannabidiol (CBD) content. Here, we compared concentrations of THC and CBD in different types of cannabis resin collected in Europe (either Moroccan-type, or Dutch-type).

Advances in nano/microscale electrochemical sensors and biosensors for analysis of single vesicles, a key nanoscale organelle in cellular communication.

The study of subcellular targets and biochemical processes within a living cell is valuable for biological and medical research. Secretory vesicles, one such important intracellular target, are nanoscale lipid structures that are capable of storage, transport, and secretion of, for example, neurotransmitters, hormones, proteins or waste products. Vesicles play an essential role in intercellular communication systems, as they facilitate the release of chemical messaging agents.

Cannabis adulterated with the synthetic cannabinoid receptor agonist MDMB-4en-PINACA and the role of European drug checking services.

Background: European drug checking services exchange information on drug trends within the Trans European Drug Information (TEDI) network, allowing monitoring and coordination of responses. Starting in Spring 2020, several services detected the synthetic cannabinoid receptor agonist MDMB-4en-PINACA in adulterated low-THC cannabis products.

Methods: Cannabis products suspected of adulteration were analyzed for the presence of MDMB-4en-PINACA by 9 services in 8 countries within the TEDI network.

Cannabis and COVID-19: Reasons for Concern.

The lockdown measures implemented to curb the spread of SARS-CoV-2 may affect (illicit) drug consumption patterns. This rapid response study investigated changes in cannabis use in a non-probability sample of cannabis users in the Netherlands during the early lockdown period. We fielded an online cross-sectional survey 4-6 weeks after implementation of lockdown measures in the Netherlands on March 15, 2020.

Signatures of knee osteoarthritis in women in the temporal and fractal dynamics of human gait.

Background: Osteoarthritis of the knee is characterized by progressive cartilage deterioration causing pain and function loss. Symptoms develop late with limited disease-modifying opportunities. Osteoarthritis is a major cause of immobility, with a higher prevalence above 60 years.

Biomechanical Alterations during Sit-to-Stand Transfer Are Caused by a Synergy between Knee Osteoarthritis and Obesity.

Osteoarthritis is one of the major causes of immobility and its current prevalence in elderly (>60 years) is 18% in women and 9.6% in men. Patients with osteoarthritis display altered movement patterns to avoid pain and overcome movement limitations in activities of daily life, such as sit-to-stand transfers.

Electrochemical sensing with single nanoskived gold nanowires bisecting a microchannel.

We suspended a single nanoskived gold nanowire in a microfluidic channel. In this preliminary report, a 200 nm-diameter nanowire was used as an electrode to perform hydrodynamic voltammetry in the center of solution flow. Suspended nanowires exhibit superior current response due to highly efficient mass transport in the area of fastest flow.

Fused Deposition Modeling 3D Printing for (Bio)analytical Device Fabrication: Procedures, Materials, and Applications.

In this work, the use of fused deposition modeling (FDM) in a (bio)analytical/lab-on-a-chip research laboratory is described. First, the specifications of this 3D printing method that are important for the fabrication of (micro)devices were characterized for a benchtop FDM 3D printer. These include resolution, surface roughness, leakage, transparency, material deformation, and the possibilities for integration of other materials.

Implementing oxygen control in chip-based cell and tissue culture systems.

Oxygen is essential in the energy metabolism of cells, as well as being an important regulatory parameter influencing cell differentiation and function. Interest in precise oxygen control for in vitro cultures of tissues and cells continues to grow, especially with the emergence of the organ-on-a-chip and the desire to emulate in vivo conditions. This was recently discussed in this journal in a Critical Review by Brennan et al.

Bisecting Microfluidic Channels with Metallic Nanowires Fabricated by Nanoskiving.

This paper describes the fabrication of millimeter-long gold nanowires that bisect the center of microfluidic channels. We fabricated the nanowires by nanoskiving and then suspended them over a trench in a glass structure. The channel was sealed by bonding it to a complementary poly(dimethylsiloxane) structure.