China 
Africa 
Explore chapters and articles related to this topic
Order Blubervirales: Surface Protein
Published in Paul Pumpens, Peter Pushko, Philippe Le Mercier, Virus-Like Particles, 2022
Paul Pumpens, Peter Pushko, Philippe Le Mercier
Remarkably, the ZZ-BNCs adsorbed onto the gold surface of the sensor chip of the quartz crystal microbalance markedly enhanced the sensitivity and antigen-binding capacity of the chip (Iijima et al. 2011). Moreover, using high-speed atomic force microscopy, Iijima et al. (2012) showed that the ZZ-BNCs tethered a maximum of 60 IgG molecules, displayed the Fv regions outwardly in an oriented-immobilization manner, and enabled the Fv regions to undergo rotational Brownian motion.
Toxicity Analysis of Ag and Au Nanoparticles
Published in Suresh C. Pillai, Yvonne Lang, Toxicity of Nanomaterials, 2019
The NP flow rate in a solution (physiological liquids or incubation media) is a parameter that has often been neglected when studying the transport processes of NPs. NP transport experiments have been performed under static conditions in a Petri dish. Upright and inverted cell cultures have been studied by Cho et al., reporting that cellular uptake of Au-NPs depends on the sedimentation and diffusion velocities of the NPs [43]. Other researchers explored the gravitational settling of NPs [44] and the time linearity of the intracellular concentration of NPs. They showed also that the uptake of NPs is essentially irreversible [44]. These studies were performed under static conditions and the NPs were tested in a Petri dish following the NP settlement onto a cell culture. Quartz crystal microbalance with dissipation monitoring (QCM-D) was used in a flow chamber to follow the particles deposition/sedimentation under flow conditions [45]. Although the flow in a QCM-D chamber does not precisely depict how particles/NPs will move over a real human system, it brings researchers one step further in mimicking a real in vivo experiment in which the NPs are exposed to flow rates. To get a glimpse into understanding how the flow rate affects the NPs’ deposition rate, researchers studied the NPs’ behaviour under no-flow conditions and under different flow rates (from 50 to 250 µL/min).
Artificial Olfactory Systems Can Detect Unique Odorant Signature Of Cancerous Volatile Compounds
Published in Raquel Cumeras, Xavier Correig, Volatile organic compound analysis in biomedical diagnosis applications, 2018
The sensors can base their working principle on the measurement of different physical parameters, such as electrical conductivity (chemiresistors; conducting polymers), piezoelectric properties (quartz crystal microbalance (QCM); surface acoustic wave (SAW)), optical properties (optical sensors; colorimetric sensors), or work function (field effect transistors (FET)) (Arshak et al., 2004). Figure 4.1 shows the signals acquired by a QCM sensor exposed to the breath samples of different individuals, which captured the resonance frequency shift caused by the interaction of the sensing material with the volatile organic compounds (VOCs) from the breath.
Effects of crosslink density in zwitterionic hydrogel coatings on their antifouling performance and susceptibility to silt uptake
Published in Biofouling, 2020
Julian Koc, Eric Schönemann, Robin Wanka, Nick Aldred, Anthony S. Clare, Harrison Gardner, Geoffrey W. Swain, Kelli Hunsucker, Andre Laschewsky, Axel Rosenhahn
The water uptake of the films when immersed in water was quantified using a quartz crystal microbalance. As shown in Figure 2B, water uptake from solution was much faster than from the humid atmosphere, reaching its final value in <1 min. The extent of water uptake also correlated inversely with the degree of crosslinking (Figure 2B and Table 4). The largest water uptake was observed for the films of PxSPE-1, which exhibited a 25 kHz shift of the resonance frequency due to the water uptake. This corresponds to an 184% increase of the frequency and thus of the total film mass due to swelling. The water uptake was considerably lower for the coating made of copolymer PxSPE-10 with the highest crosslinker density, limiting the relative increase of the frequency, and thus of the swelling, to 95%. The trend of increasing water uptake with decreasing crosslink density is in line with the spectroscopic ellipsometry experiments in high humidity. As a result of being in direct contact with water, the swelling of PXSPE-1 is four times larger in the QCM measurement compared to the ellipsometry measurement, which only allowed the films to absorb water from a saturated water vapor atmosphere.
Antifouling properties of layer by layer DNA coatings
Published in Biofouling, 2019
Guruprakash Subbiahdoss, Guanghong Zeng, Hüsnü Aslan, Jakob Ege Friis, Joseph Iruthayaraj, Alexander N. Zelikin, Rikke Louise Meyer
A quartz crystal microbalance with dissipation monitoring (QCM, Q-Sense AB, Gothenburg, Sweden) was used to monitor the LBL self-assembly process, where change in resonance frequency and dissipation of an oscillating quartz crystal indicates change in the mass and viscoelastic properties of the coating. In brief, the sensor crystal (QSX 304 stainless steel, SS2343) was stored in 2% SDS, washed with MilliQ water, dried in a stream of nitrogen gas, and subjected to UV-ozone treatment for 40 min. UV-treated sensor crystals were washed with MilliQ water and dried in a stream of nitrogen gas before being mounted in the QCM-D mounting chambers. Assembly of the multi-layer on the crystal was carried out by contacting PEI solution (0.5 mg ml−1) and DNA solution (0.5 mg ml−1) alternately at a flow rate of 0.1 ml min−1. To remove the loosely bound molecules, MilliQ water was rinsed for 5 min at 0.1 ml min−1 between each adsorption. Measurements were carried out with the Q-Sense E4 system (Q-Sense AB) temperature maintained at 22 °C. Each sensor crystal was monitored using the Q-soft software at different overtones (3rd, 5th, 7th, 9th and 11th). The adsorbed mass change Δm during the film assembly was calculated using the Sauerbrey equation (Cortez et al. 2010) given below: −2 Hz−1, ΔF is the frequency change and n is the overtone.
Monovalent TNF receptor 1-selective antibody with improved affinity and neutralizing activity
Published in mAbs, 2019
Fabian Richter, Kirstin A. Zettlitz, Oliver Seifert, Andreas Herrmann, Peter Scheurich, Klaus Pfizenmaier, Roland E. Kontermann
Binding kinetics were determined by quartz crystal microbalance measurements using a A-100 C-Fast or Cell-200 C-Fast (Attana, Stockholm, Sweden). Human TNFR1-Fc was immobilized on the sensor chip according to the manufacturer’s amine coupling protocol at the indicated densities. Studies were performed using PBST (0.1% Tween-20, pH 7.4) as running buffer at 37 °C, applying a flow rate of 25 µl/min. Reference measurements were performed after every second protein injection using PBST and subtracted from the obtained binding curves. Sensor chips were regenerated after each measurement and reference injection using 25 µl 5 mM NaOH or 20 mM glycine, pH 2.0. Data analysis was performed using Attaché Office Evaluation software (Attana, Stockholm, Sweden) and TraceDrawe (ridgview instruments, Vange, Sweden).