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Face Masks and Hand Sanitizers
Published in Hanadi Talal Ahmedah, Muhammad Riaz, Sagheer Ahmed, Marius Alexandru Moga, The Covid-19 Pandemic, 2023
Shahzad Sharif, Mahnoor Zahid, Maham Saeed, Izaz Ahmad, M. Zia-Ul-Haq, Rizwan Ahmad
A novel system comprising polyethylene-based nanofiber with modifications like thermal stability, self-ability to sanitize and re-usability was developed. System for thermal stability basically increases or decreases the dissipation of heat according to environmental requirements. Getting a silver layer into it, avoids the loss of heat when temperature is low. Due to high dispersal of heat from the human body, the material also exhibited an excellent cooling effect [99].
Commissioning and Routine Quality Assurance of the C-RAD Catalyst™ and Sentinel™ 4D-CT Systems
Published in Jeremy D. P. Hoisak, Adam B. Paxton, Benjamin Waghorn, Todd Pawlicki, Surface Guided Radiation Therapy, 2020
Alonso N. Gutierrez, Dennis N. Stanley
The temporal system drift and static spatial reproducibility should be performed as one of the initial evaluation metrics when commissioning both the Catalyst and Sentinel 4D-CT imaging systems. AAPM TG-147 recommends monitoring and recording a test pattern device at initial startup of the equipment for at least 90 min or until sufficient stability is achieved due to system thermal drift vulnerability.13 To evaluate the thermal system drift, the system can be initialized from a cold start where the entire system has been powered down. After thermal stability is achieved, the static spatial reproducibility can be evaluated by monitoring the position of a static device for a period. These tests are also recommended to be performed at least annually or after equipment changes.
Cytochrome P450 Enzymes for the Synthesis of Novel and Known Drugs and Drug Metabolites
Published in Peter Grunwald, Pharmaceutical Biocatalysis, 2019
Sanjana Haque, Yuqing Gong, Sunitha Kodidela, Mohammad A. Rahman, Sabina Ranjit, Santosh Kumar
CYPBM3 can also be engineered to enhance thermal stability (Eiben et al., 2007; Geronimo et al., 2016) and H2O2 utilization (Whitehouse et al., 2009; Lim and Sikes, 2015). One approach is to replace the CYPBM3 reductase domain with FAD/FMN reductase domain to improve temperature catalytic tolerance. The maximum activity of this engineered CYPBM3 was obtained at 51°C, and the half-life of the engineered CYPBM3 was ten times longer than the wild-type CYPBM3 (Eiben et al., 2007). Additionally, a recent study showed a targeted region on CYPBM3, which can be used to improve stability. They showed the structural data for wide-type CYPBM3 and R47L/F87V/L188Q/E267V/F81I pentuple mutant (PM) with the native substrate palmitic acid. Then they performed a high-temperature molecular dynamics simulations, and identified labile regions in PM that can be targeted for mutation to improve stability (Geronimo et al., 2016). In addition, engineering of CYPBM3 can also optimize the production of H2O2, which is an important element in redox biology. For example, I401P, an engineered CYPBM3, was able to alter NADPH consumption rates and had more reduction potential than the wild-type CYPBM3 (Whitehouse et al., 2009). Recently, the production of H2O2 by this engineered CYPBM3 and wild-type CYPBM3 was measured using a genetically encoded H2O2 sensor. The result showed that engineered CYPBM3 has an enhanced H2O2 production compared to wild-type CYPBM3 (Lim and Sikes, 2015).
The impact of standard accelerated stability conditions on antibody higher order structure as assessed by mass spectrometry
Published in mAbs, 2019
Richard A. Kerr, David A. Keire, Hongping Ye
Importantly, our data highlighted that the structural stability of ‘x’ increased over time at the expense of both the native conformation and proceeding unfolding intermediate (intermediate 1, Figure 2). The increased stability of ‘x’ was further observed in tandem with the reduced lifetime of the native-like fold under CIU conditions (Figure 2). Taken together these observations are attributed to the thermal stability decrease of the biotherapeutics tested over time. The reduced thermal stability of the native conformation may indicate an increased risk of protein misfolding that may in turn act as a pathway to subsequent protein aggregation.44 Furthermore, the existence of such misfolded species could further increase the inherent risk of immunogenic responses, either directly or through an downstream subvisible aggregate formation.45
Immobilization of Trichoderma harzianum α-amylase on PPyAgNp/Fe3O4-nanocomposite: chemical and physical properties
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2018
Saleh A. Mohamed, Majed H. Al-Harbi, Yaaser Q. Almulaiky, Ibrahim H. Ibrahim, Hala A. Salah, Mohamed O. El-Badry, Azza M. Abdel-Aty, Afaf S. Fahmy, Reda M. El-Shishtawy
The optimum temperature of soluble α-amylase and immobilized α-amylase on 10% PPyAgNp/Fe3O4-nanocomposite was detected at 40 °C and 50 °C, respectively (Figure 7). At 80 °C, the results appeared that the immobilized enzyme retained 40% of its initial activity, while the soluble enzyme retained 20%. The results showed that optimum temperature for the immobilized enzyme shifted towards higher temperatures. The same results reported that the temperature optimum of free α-amylase shifted from 40 °C to 50 °C after immobilization of α-amylase on magnetic Fe2O3 nanoparticles [17]. The slow degradation of the substrate was detected at higher temperature because the structure of enzyme is altered [29]. After immobilization an increase in temperature optimum of immobilized enzymes revealed that the enzyme might be more rigid to structural changes induced by heat [30,31]. On the contrary, the low and the same optimum temperature of free and immobilized α-amylase on nano-polyethylene film was 30 °C [21]. The maximum activity was also observed at 40 °C for both free and immobilized α-amylase amino-functionalized magnetite nanoparticles [19]. The study of thermal stability is shown in Figure 8. Up to 50 °C the two enzymes were thermal stable after incubation for one hour, whereas at 80 °C the soluble and immobilized α-amylases lost 85% and 70% of its activity, respectively.
Challenges and new frontiers in analytical characterization of antibody-drug conjugates
Published in mAbs, 2018
Anil Wagh, Hangtian Song, Ming Zeng, Li Tao, Tapan K. Das
The moieties added in an ADC via the drug and linker may introduce more liability to light-induced degradation that are not present in the antibody, the drug, or the linker. Cockrell et al. evaluated light exposure in a model ADC system and demonstrated that aggregate and particulate formation specific to the ADC is due to light sensitivity, and these phenomena were not observed in the starting antibody or the linker payload alone.88 Thermal stability using differential scanning calorimetry was studied by Acchione et al. for a series of lysine-linked, thiol-linked, and carbohydrate-linked model IgG1-biotin conjugates. The primary finding from this work was that the thiol coupling had a greater destabilizing effect on the antibody than lysine coupling. It was also observed that partial antibody reduction using tris-(2-carboxyethyl)-phosphine had very minimal effect on overall thermal stability, suggesting that the observed loss of stability is not directly due to partial reduction of antibody.79