4,071 research outputs found

    Aging effects on airflow dynamics and lung function in human bronchioles

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    Background and objective The mortality rate for patients requiring mechanical ventilation is about 35% and this rate increases to about 53% for the elderly. In general, with increasing age, the dynamic lung function and respiratory mechanics are compromised, and several experiments are being conducted to estimate these changes and understand the underlying mechanisms to better treat elderly patients. Materials and methods Human tracheobronchial (G1 ~ G9), bronchioles (G10 ~ G22) and alveolar sacs (G23) geometric models were developed based on reported anatomical dimensions for a 50 and an 80-year-old subject. The aged model was developed by altering the geometry and material properties of the model developed for the 50-year-old. Computational simulations using coupled fluid-solid analysis were performed for geometric models of bronchioles and alveolar sacs under mechanical ventilation to estimate the airflow and lung function characteristics. Findings The airway mechanical characteristics decreased with aging, specifically a 38% pressure drop was observed for the 80-year-old as compared to the 50-year-old. The shear stress on airway walls increased with aging and the highest shear stress was observed in the 80-year-old during inhalation. A 50% increase in peak strain was observed for the 80-year-old as compared to the 50-year-old during exhalation. The simulation results indicate that there is a 41% increase in lung compliance and a 35%-50% change in airway mechanical characteristics for the 80-year-old in comparison to the 50-year-old. Overall, the airway mechanical characteristics as well as lung function are compromised due to aging. Conclusion Our study demonstrates and quantifies the effects of aging on the airflow dynamics and lung capacity. These changes in the aging lung are important considerations for mechanical ventilation parameters in elderly patients. Realistic geometry and material properties need to be included in the computational models in future studies

    Lesions of either anterior orbitofrontal cortex or ventrolateral prefrontal cortex in marmoset monkeys heighten innate fear and attenuate active coping behaviors to predator threat.

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    The ventral prefrontal cortex is an integral part of the neural circuitry that is dysregulated in mood and anxiety disorders. However, the contribution of its distinct sub-regions to the regulation of negative emotion are poorly understood. Recently we implicated both the ventrolateral prefrontal cortex (vlPFC) and anterior orbitofrontal cortex (antOFC) in the regulation of conditioned fear and anxiety responses to a social stimulus, i.e., human intruder, in the marmoset monkey. In the present study we extend our investigations to determine the role of these two regions in regulating innate responses and coping strategies to a predator stimulus, i.e., a model snake. Both the vlPFC and antOFC lesioned groups exhibited enhanced anxiety-related responses to the snake in comparison to controls. Both groups also showed a reduction in active coping behavior. These results indicate that the vlPFC and antOFC contribute independently to the regulation of both innate fear and, as previously reported, conditioned fear, and highlight the importance of these regions in producing stimulus-appropriate coping responses. The finding that dysregulation in two distinct prefrontal regions produces the apparently similar behavioral phenotype of heightened negative emotion provides insight into the varied etiology that may underlie this symptom across a wide variety of neuropsychiatric conditions with implications for personalized treatment strategies.This research was supported by a Medical Research Programme Grant (G0901884) from the Medical Research Council (MRC), UK to Angela C. Roberts. Yoshiro Shiba was supported by the Long Term Student Support Program provided by Osaka University and the Ministry of Education, Culture, Sports, Science and Technology of Japan and currently by the MRC Programme grant (G0901884). Andrea M. Santangelo, until October 2011, by a J. S. McDonnell Foundation grant (Principle Investigators; E. Phelps, T. W. Robbins, co-investigators; J. E. LeDoux, and Angela C. Roberts) and currently by the MRC Programme grant (G0901884). Work was carried out within the Behavioral and Clinical Neurosciences Institute supported by a consortium award from the Wellcome Trust and the MRC. We thank Dr. Carmen Agustín-Pavón for conducting the lesion surgeries, Dr. Katrin Braesicke for help with statistical analyses and Dr. Mercedes Arroyo for the preparation of histological material.This is the final published version of the paper, which first appeared in Frontiers Systems Neuroscience, 21 January 2015, doi: 10.3389/fnsys.2014.0025

    Use of Imaging Spectrometer Data and Multispectral Imagery for Improved Earthquake Response

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    Imaging and Applied Optics Technical Digest, 2012Multispectral imagery and imaging spectrometer data are used to develop prototype map products for improved earthquake response. A tiered approach keyed to post-event communications infrastructure is directed at providing critical information to emergency services personnel.This research is supported by the Science and Technology (S&T) Directorate, Department of Homeland Security (DHS). We gratefully acknowledge the participation of emergency responders and managers from the cities and counties of Monterey, Los Angeles, San Diego, and Riverside California. We also appreciate contributions during project definition stage and follow-ups by the California Emergency Management Agency (Cal EMA) and the Federal Emergency Management Agency (FEMA), the U.S. Geological Survey, and DHS. AVIRIS data were acquired by NASA/JPL. The LiDAR data were provided by the Association of Monterey Bay Area Governments, via a USGS grant through the American Reinvestment and Recovery Act of 2009. WV-2 data were provided by the National Geospatial Intelligence Agency (NGA) under the NextView imagery license agreement

    Alcohol-dysregulated miR-30a and miR-934 in head and neck squamous cell carcinoma.

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    BackgroundAlcohol consumption is a well-established risk factor for head and neck squamous cell carcinoma (HNSCC); however, the molecular mechanisms by which alcohol promotes HNSCC pathogenesis and progression remain poorly understood. Our study sought to identify microRNAs that are dysregulated in alcohol-associated HNSCC and investigate their contribution to the malignant phenotype.MethodUsing RNA-sequencing data from 136 HNSCC patients, we compared the expression levels of 1,046 microRNAs between drinking and non-drinking cohorts. Dysregulated microRNAs were verified by qRT-PCR in normal oral keratinocytes treated with biologically relevant doses of ethanol and acetaldehyde. The most promising microRNA candidates were investigated for their effects on cellular proliferation and invasion, sensitivity to cisplatin, and expression of cancer stem cell genes. Finally, putative target genes were identified and evaluated in vitro to further establish roles for these miRNAs in alcohol-associated HNSCC.ResultsFrom RNA-sequencing analysis we identified 8 miRNAs to be significantly upregulated in alcohol-associated HNSCCs. qRT-PCR experiments determined that among these candidates, miR-30a and miR-934 were the most highly upregulated in vitro by alcohol and acetaldehyde. Overexpression of miR-30a and miR-934 in normal and HNSCC cell lines produced up to a 2-fold increase in cellular proliferation, as well as induction of the anti-apoptotic gene BCL-2. Upon inhibition of these miRNAs, HNSCC cell lines exhibited increased sensitivity to cisplatin and reduced matrigel invasion. miRNA knockdown also indicated direct targeting of several tumor suppressor genes by miR-30a and miR-934.ConclusionsAlcohol induces the dysregulation of miR-30a and miR-934, which may play crucial roles in HNSCC pathogenesis and progression. Future investigation of the alcohol-mediated pathways effecting these transformations will prove valuable for furthering the understanding and treatment of alcohol-associated HNSCC

    An Assessment of Nutrition Practices and Attitudes in Family Child-Care Homes: Implications for Policy Implementation

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    Introduction: Family child-care homes (FCCHs) provide care and nutrition for millions of US children, including 28% in Rhode Island. New proposed regulations for FCCHs in Rhode Island require competencies and knowledge in nutrition. We explored nutrition-related practices and attitudes of FCCH providers in Rhode Island and assessed whether these differed by provider ethnicity or socioeconomic status of the enrolled children. Methods: Of 536 licensed FCCHs in Rhode Island, 105 randomly selected FCCH providers completed a survey about provider nutrition attitudes and practices, demographics of providers, and characteristics of the FCCH, including participation in the federal Child and Adult Care Food Program (CACFP). No differences between CACFP and non-CACFP participants were found; responses were compared by provider ethnicity using χ2 tests and multivariate models. Results: Nearly 70% of FCCHs reported receiving nutrition training only 0 to 3 times during the past 3 years; however, more than 60% found these trainings to be very helpful. More Hispanic than non-Hispanic providers strongly agreed to sitting with children during meals, encouraging children to finish their plate, and being involved with parents on the topics of healthy eating and weight. These differences persisted in multivariate models. Discussion: Although some positive practices are in place in Rhode Island FCCHs, there is room for improvement. State licensing requirements provide a foundation for achieving better nutrition environments in FCCHs, but successful implementation is key to translating policies into real changes. FCCH providers need culturally and linguistically appropriate nutrition-related training

    Gas Adsorption in Novel Environments, Including Effects of Pore Relaxation

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    Adsorption experiments have been interpreted frequently with simplified model geometries, such as ideally flat surfaces and slit or cylindrical pores. Recent explorations of unusual environments, such as fullerenes and metal-organic-framework materials, have led to a broadened scope of experimental, theoretical and simulation investigations. This paper reviews a number of such studies undertaken by our group. Among the topics receiving emphasis are these: universality of gas uptake in pores, relaxation of a porous absorbent due to gas uptake and the novel phases of gases on a single nanotube, all of which studies have been motivated by recent experiments

    Virus-templated Au and Au–Pt core–shell nanowires and their electrocatalytic activities for fuel cell applications

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    A facile synthetic route was developed to make Au nanowires (NWs) from surfactant-mediated bio-mineralization of a genetically engineered M13 phage with specific Au binding peptides. From the selective interaction between Au binding M13 phage and Au ions in aqueous solution, Au NWs with uniform diameter were synthesized at room temperature with yields greater than 98% without the need for size selection. The diameters of Au NWs were controlled from 10 nm to 50 nm. The Au NWs were found to be active for electrocatalytic oxidation of CO molecules for all sizes, where the activity was highly dependent on the surface facets of Au NWs. This low-temperature high yield method of preparing Au NWs was further extended to the synthesis of Au–Pt core–shell NWs with controlled coverage of Pt shell layers. Electro-catalytic studies of ethanol oxidation with different Pt loading showed enhanced activity relative to a commercial supported Pt catalyst, indicative of the dual functionality of Pt for the ethanol oxidation and Au for the anti-poisoning component of Pt. These new one-dimensional noble metal NWs with controlled compositions could facilitate the design of new alloy materials with tunable properties.United States. Army Research Office (Institute for Collaborative Biotechnologies, grant W911NF-09-0001)National Science Foundation (U.S.) (MRSEC Program, award no. DMR–0819762)Samsung (Firm) (Samsung Foundation of Culture, Samsung Scholarship
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