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Background With the increase in production and use of engineered nanoparticles (NP; ≤ 100 nm), safety concerns have risen about the potential health effects of occupational or environmental NP exposure. Results of animal toxicology studies suggest that inhalation of NP may cause pulmonary injury with subsequent acute or chronic inflammation. People with chronic respiratory diseases like asthma or allergic rhinitis may be even more susceptible to toxic effects of inhaled NP. Few studies, however, have investigated adverse effects of inhaled NP that may enhance the development of allergic airway disease. Methods We investigated the potential of polyethylene glycol coated amorphous silica NP (SNP; 90 nm diameter) to promote allergic airway disease when co-exposed during sensitization with an allergen. BALB/c mice were sensitized by intranasal instillation with 0.02% ovalbumin (OVA; allergen) or saline (control), and co-exposed to 0, 10, 100, or 400 μg of SNP. OVA-sensitized mice were then challenged intranasally with 0.5% OVA 14 and 15 days after sensitization, and all animals were sacrificed a day after the last OVA challenge. Blood and bronchoalveolar lavage fluid (BALF) were collected, and pulmonary tissue was processed for histopathology and biochemical and molecular analyses. Results Co-exposure to SNP during OVA sensitization caused a dose-dependent enhancement of allergic airway disease upon challenge with OVA alone. This adjuvant-like effect was manifested by significantly greater OVA-specific serum IgE, airway eosinophil infiltration, mucous cell metaplasia, and Th2 and Th17 cytokine gene and protein expression, as compared to mice that were sensitized to OVA without SNP. In saline controls, SNP exposure did cause a moderate increase in airway neutrophils at the highest doses. Conclusions These results suggest that airway exposure to engineered SNP could enhance allergen sensitization and foster greater manifestation of allergic airway disease upon secondary allergen exposures. Whereas SNP caused innate immune responses at high doses in non-allergic mice, the adjuvant effects of SNP were found at lower doses in allergic mice and were Th2/Th17 related. In conclusion, these findings in mice suggest that individuals exposed to SNP might be more prone to manifest allergic airway disease, due to adjuvant-like properties of SNP.

\"The Pendulum: A Case Study in Physics\" describes one physical system - the pendulum - and its manifestations in classical and modern physics. While being a technical work, this remarkable study is set within the context of the technological, historical, and cultural developments to which the pendulum has contributed.

The pendulum is a unique physical system which exhibits remarkably varied and complex behavior under many different conditions. Seven 'tales', detailing different important facets of the pendulum, show the exciting diversity of the science of the pendulum, and its untold significance in the history of human intellectual development.

To determine whether inhaled immunostimulatory DNA sequence oligonucleotides containing CpG motifs mitigate the pathophysiologic manifestation of the asthmatic phenotype (airways hyperresponsiveness and airways remodeling), rhesus monkeys with experimentally induced allergic airways disease were treated seven times with inhaled immunostimulatory oligonucleotides (or sham) periodically for 33 weeks. Airways hyperresponsiveness was reduced twofold in immunostimulatory DNA sequence-treated compared with sham-treated monkeys. Airways from immunostimulatory oligonucleotide-treated monkeys had thinner reticular basement membranes, fewer mucous cells, fewer eosinophils, and fewer mast cells than sham-treated allergic monkeys. We conclude that inhaled immunostimulatory oligonucleotides can attenuate the magnitude of airway hyperreactivity and airways remodeling produced in nonhuman primates with experimentally induced allergic airways disease.

Excitation of hexanuclear molybdenum complexes such as Mo6Cl12 and its derivatives in the ultraviolet results in a strongly red-shifted luminescence centered at 750nm. Since oxygen efficiently quenches the luminescence, these thermally stable inorganic complexes are candidate lumophores for real-time, high temperature optical fiber based sensing of oxygen. Sol-gel films containing the acetonitrile complex of Mo6Cl12 were deposited on quartz substrates by dip coating. After drying, the films were heated at 200∘C for 1 h. The luminescence lineshapes of films before and after heating were unchanged, indicating that heating did not adversely affect the cluster photophysics. Compared to solutions of the acetonitrile complex, quenching by oxygen was smaller in the as-prepared films, but heating at 200∘C for 1 h increased the quenching, apparently due to increased oxygen permeability resulting from the loss of water or other small molecules from the matrix. These results confirm the potential of hexanuclear molybdenum complexes such as Mo6Cl12⋅2CH3CN as the lumophores in fiber optic oxygen sensors that can operate up to 200∘C.

Remodeling of the epithelial basement membrane zone (BMZ) involves increased deposition of collagen, resulting in thickening of the BMZ. The current study focuses on fibroblast growth factor-2 (FGF-2) in the tracheal BMZ in house dust mite allergen (HDMA)-sensitized infant rhesus monkeys, challenged with HDMA at a time when the BMZ is undergoing active postnatal development. To detect structural changes in the BMZ, we measured collagens I, III, and V. To detect changes in the function of the BMZ, we measured immunoreactivity of the heparan sulfate proteoglycan, perlecan, and FGF-2. We found significant thickening of the tracheal BMZ (p < 0.05) with each of these parameters. We also found that all HDMA tracheal samples expressed thin focal areas of the BMZ associated with leukocyte trafficking. These areas were depleted of perlecan and FGF-2; however, increased FGF-2 immunoreactivity was present in the adjacent basal cells. We conclude that basal cells and FGF-2 are involved with significant remodeling of the BMZ in the developing trachea of infant rhesus monkeys exposed to HDMA.

The pendulum: a case study in physics is a unique book in several ways. Firstly, it is a comprehensive quantitative study of one physical system, the pendulum, from the viewpoint of elementary and more advanced classical physics, modern chaotic dynamics, and quantum mechanics. In addition, coupled pendulums and pendulum analogs of superconducting devices are also discussed. Secondly, this book treats the physics of the pendulum within a historical and cultural context, showing, for example, that the pendulum has been intimately connected with studies of the earth's density, the earth's motion, and timekeeping. While primarily a physics book, the work provides significant added interest through the use of relevant cultural and historical vignettes. This approach offers an alternative to the usual modern physics courses. The text is amply illustrated and augmented by exercises at the end of each chapter.

A key challenge in measuring gene expression changes in the lung in response to site-selective toxicants is differentiating between target and nontarget areas. The toxicity for the cytotoxicant 1-nitronaphthalene is highly localized in the airway epithelium. Target cells comprise but a fraction of the total lung cell mass; measurements from whole lung homogenates are not likely to reflect what occurs at the target site. Additionally, the use of generic microarrays to measure expression in airway epithelium may not provide a good representation of transcripts present at the site of toxic action. cDNA libraries from airway and alveolar subcompartments of rat lung were sequenced for the development of a custom microarray representative of these lung regions. We identified 7,460 nonredundant rat lung sequences. Nearly 30% of the sequences on this array are not present on the Affymetrix Rat GeneChip 230. A 20,000-element microarray was developed that delineates differences in gene expression between subcompartments. This is the first in a series of articles employing this microarray for detecting gene expression changes during acute injury produced by 1-nitronaphthalene and subsequent repair.