Correlation between the median particle size of chewed frankfurter sausage and almonds during masticatory performance test

The correlation between chewing and gastric function is best reflected when the same food type is used during both tests. We proposed frankfurter sausage as test food for masticatory performance as it can also be used in gastric emptying test. The suitability of frankfurter sausage to determine masticatory performance, however, has never been examined. To examine the correlations between the median particle size of frankfurter sausage and almonds (as standard test food) after different numbers of chewing cycles. Twenty‐seven subjects performed masticatory performance tests by chewing 2 types of test foods, that is, a piece of almond or 5‐g frankfurter sausage cubes placed in a sealed latex bag, for 5 and 15 chewing cycles. For each individual, right and left sides were tested separately. Chewed samples obtained from both sides were pooled. Median particle sizes were determined using a multiple sieving method. Spearman’s rank correlation was used to examine any correlation between median particle sizes of the 2 test foods after 5 and 15 cycles. Median particle sizes after 5 and 15 cycles were 2.04 ± 0.87 and 0.95 ± 0.58 mm for almonds and 4.16 ± 0.19 and 3.73 ± 0.25 mm for frankfurter sausage, respectively. Significant correlations were observed between the median particle size of chewed frankfurter sausage after 15 cycles and that of chewed almonds after 5 and 15 cycles (r = .76, P < .01 and r = .52, P = .01, respectively). Frankfurter sausage chewed for 15 cycles may be suitable for the determination of masticatory performance in conjunction with gastric emptying test.     

Hardening of Additive Manufactured 316L Stainless Steel by Using Bimodal Powder Containing Nanoscale Fraction

The particle size distribution significantly affects the material properties of the additively manufactured parts. In this work, the influence of bimodal powder containing nano- and micro-scale particles on microstructure and materials properties is studied. Moreover, to study the effect of the protective atmosphere, the test samples were additively manufactured from 316L stainless steel powder in argon and nitrogen. The samples fabricated from the bimodal powder demonstrate a finer subgrain structure, regardless of protective atmospheres and an increase in the Vickers microhardness, which is in accordance with the Hall-Petch relation. The porosity analysis revealed the deterioration in the quality of as-built parts due to the poor powder flowability. The surface roughness of fabricated samples was the same regardless of the powder feedstock materials used and protective atmospheres. The results suggest that the improvement of mechanical properties is achieved by adding a nano-dispersed fraction, which dramatically increases the total surface area, thereby contributing to the nitrogen absorption by the material.     

Comparative numerical modeling of inhaled micron-sized particle deposition in human and rat nasal cavities

Abstract

Micron-sized particle deposition in anatomically realistic models of a rat and human nasal cavity was numerically investigated. A steady laminar inhalation flow rate was applied and particles were released from the outside air. Particles showing equivalent total particle deposition fractions were classified into low, medium and high inertial particle. Typical particle sizes are 2.5, 9 and 20 μm for the human model and 1, 2 and 3 μm for the rat model, respectively. Using a surface-mapping technique the 3D nasal cavity surface was “unwrapped” into a 2D domain and the particle deposition locations were plotted for complete visual coverage of the domain surface. The total surface area comparison showed that the surface area of the human nasal model was about ten times the size of the rat model. In contrast, the regional surface area percentage analysis revealed the olfactory region of the rat model was significantly larger than all other regions making up ～55.6% of the total surface area, while that of the human nasal model only occupying 10.5%. Flow pattern comparisons showed rapid airflow acceleration was found at the nasopharynx region and the nostril region for the human and rat model, respectively. For the human model, the main passage is the major deposition region for micro-particles. While for the rat model, it is the vestibule. Through comparing the regional deposition flux between human and rat models, this study can contribute towards better extrapolation approach of inhalation exposure data between inter-subject species.     

Human Antibody Fragments Specific for the Epidermal Growth Factor Receptor Selected from Large Non-immunised Phage Display Libraries

Antibodies to EGFR have been shown to display anti-tumour effects mediated in part by inhibition of cellular proliferation and angiogenesis, and by enhancement of apoptosis. Humanised antibodies are preferred for clinical use to reduce complications with HAMA and HAHA responses frequently seen with murine and chimaeric antibodies. We have used depletion and subtractive selection strategies on cells expressing the EGFR to sample two large antibody fragment phage display libraries for the presence of human antibodies which are specific for the EGFR. Four Fab fragments and six scFv fragments were identified, with affinities of up to 2.2 nM as determined by BIAcore analysis using global fitting of the binding curves to obtain the individual rate constants (k_a and k_d). This overall approach offers a generic screening method for the identification of growth factor specific antibodies and antibody fragments from large expression libraries and has potential for the rapid development of new therapeutic and diagnostic reagents.     

Aerosol particle generation from solution-based pressurized metered dose inhalers: a technical overview of parameters that influence respiratory deposition

Abstract

There are a multitude of formulation factors to consider when developing a solution-based pressurized metered dose inhaler (pMDI). Evaluation of these variables and their underpinning driving force has been performed over the years. Key components, including formulation composition and device design, play significant roles in determining the aerosol performance of these solution-based formulations. This review outlines research efforts that have focused on these essential governing factors, how the aerosol performance changes when these variables are modified and fundamental mechanisms affecting the delivery efficiency of such formulations.     

Broad neutralization against SARS-CoV-2 variants induced by ancestral and B.1.351 AS03-Adjuvanted recombinant Plant-Derived Virus-Like particle vaccines

Since 2019, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection resulting in the coronavirus disease 2019 (COVID-19) has afflicted hundreds of millions of people in a worldwide pandemic. Several safe and effective COVID-19 vaccines are now available. However, the rapid emergence of variants and risk of viral escape from vaccine-induced immunity emphasize the need to develop broadly protective vaccines. A recombinant plant-derived virus-like particle vaccine for the ancestral COVID-19 (CoVLP) recently authorized by Canadian Health Authorities and a modified CoVLP.B1351 targeting the B.1.351 variant (both formulated with the adjuvant AS03) were assessed in homologous and heterologous prime-boost regimen in mice. Both strategies induced strong and broadly cross-reactive neutralizing antibody (NAb) responses against several Variants of Concern (VOCs), including B.1.351/Beta, B.1.1.7/Alpha, P.1/Gamma, B.1.617.2/Delta and B.1.1.529/Omicron strains. The neutralizing antibody (NAb) response was robust with both primary vaccination strategies and tended to be higher for almost all VOCs following the heterologous prime-boost regimen.     

Immune-pineal axis protects rat lungs exposed to polluted air

Environmental pollution in the form of particulate matter <2.5 μm (PM_2.5) is a major risk factor for diseases such as lung cancer, chronic respiratory infections, and major cardiovascular diseases. Our goal was to show that PM_2.5 eliciting a proinflammatory response activates the immune-pineal axis, reducing the pineal synthesis and increasing the extrapineal synthesis of melatonin. Herein, we report that the exposure of rats to polluted air for 6 hours reduced nocturnal plasma melatonin levels and increased lung melatonin levels. Melatonin synthesis in the lung reduced lipid peroxidation and increased PM_2.5 engulfment and cell viability by activating high-affinity melatonin receptors. Diesel exhaust particles (DEPs) promoted the synthesis of melatonin in a cultured cell line (RAW 264.7 cells) and rat alveolar macrophages via the expression of the gene encoding for AANAT through a mechanism dependent on activation of the NFκB pathway. Expression of the genes encoding AANAT, MT1, and MT2 was negatively correlated with cellular necroptosis, as disclosed by analysis of Gene Expression Omnibus (GEO) microarray data from the human alveolar macrophages of nonsmoking subjects. The enrichment score for antioxidant genes obtained from lung gene expression data (GTEx) was significantly correlated with the levels of AANAT and MT1 but not the MT2 melatonin receptor. Collectively, these data provide a systemic and mechanistic rationale for coordination of the pineal and extrapineal synthesis of melatonin by a standard damage-associated stimulus, which activates the immune-pineal axis and provides a new framework for understanding the effects of air pollution on lung diseases.