8,187 research outputs found
Long term outcomes in men screened for abdominal aortic aneurysm : prospective cohort study
PMID: 22563092 [PubMed - indexed for MEDLINE] PMCID: PMC3344734 Free PMC ArticlePeer reviewedPublisher PD
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High-throughput continuous dielectrophoretic separation of neural stem cells.
We created an integrated microfluidic cell separation system that incorporates hydrophoresis and dielectrophoresis modules to facilitate high-throughput continuous cell separation. The hydrophoresis module consists of a serpentine channel with ridges and trenches to generate a diverging fluid flow that focuses cells into two streams along the channel edges. The dielectrophoresis module is composed of a chevron-shaped electrode array. Separation in the dielectrophoresis module is driven by inherent cell electrophysiological properties and does not require cell-type-specific labels. The chevron shape of the electrode array couples with fluid flow in the channel to enable continuous sorting of cells to increase throughput. We tested the new system with mouse neural stem cells since their electrophysiological properties reflect their differentiation capacity (e.g., whether they will differentiate into astrocytes or neurons). The goal of our experiments was to enrich astrocyte-biased cells. Sorting parameters were optimized for each batch of neural stem cells to ensure effective and consistent separations. The continuous sorting design of the device significantly improved sorting throughput and reproducibility. Sorting yielded two cell fractions, and we found that astrocyte-biased cells were enriched in one fraction and depleted from the other. This is an advantage of the new continuous sorting device over traditional dielectrophoresis-based sorting platforms that target a subset of cells for enrichment but do not provide a corresponding depleted population. The new microfluidic dielectrophoresis cell separation system improves label-free cell sorting by increasing throughput and delivering enriched and depleted cell subpopulations in a single sort
Using cosmic neutrinos to search for non-perturbative physics at the Pierre Auger Observatory
The Pierre Auger (cosmic ray) Observatory provides a laboratory for studying
fundamental physics at energies far beyond those available at colliders. The
Observatory is sensitive not only to hadrons and photons, but can in principle
detect ultrahigh energy neutrinos in the cosmic radiation. Interestingly, it
may be possible to uncover new physics by analyzing characteristics of the
neutrino flux at the Earth. By comparing the rate for quasi-horizontal, deeply
penetrating air showers triggered by all types of neutrinos, with the rate for
slightly upgoing showers generated by Earth-skimming tau neutrinos, we
determine the ratio of events which would need to be detected in order to
signal the existence of new non-perturbative interactions beyond the TeV-scale
in which the final state energy is dominated by the hadronic component. We use
detailed Monte Carlo simulations to calculate the effects of interactions in
the Earth and in the atmosphere. We find that observation of 1 Earth-skimming
and 10 quasi-horizontal events would exclude the standard model at the 99%
confidence level. If new non-perturbative physics exists, a decade or so would
be required to find it in the most optimistic case of a neutrino flux at the
Waxman-Bahcall level and a neutrino-nucleon cross-section an order of magnitude
above the standard model prediction.Comment: 8 pages revtex, 4 eps figure
TXNL6 Is a Novel Oxidative Stress-Induced Reducing System for Methionine Sulfoxide Reductase A Repair of α-Crystallin and Cytochrome C in the Eye Lens
A key feature of many age-related diseases is the oxidative stress-induced accumulation of protein methionine sulfoxide (PMSO) which causes lost protein function and cell death. Proteins whose functions are lost upon PMSO formation can be repaired by the enzyme methionine sulfoxide reductase A (MsrA) which is a key regulator of longevity. One disease intimately associated with PMSO formation and loss of MsrA activity is age-related human cataract. PMSO levels increase in the eye lens upon aging and in age-related human cataract as much as 70% of total lens protein is converted to PMSO. MsrA is required for lens cell maintenance, defense against oxidative stress damage, mitochondrial function and prevention of lens cataract formation. Essential for MsrA action in the lens and other tissues is the availability of a reducing system sufficient to catalytically regenerate active MsrA. To date, the lens reducing system(s) required for MsrA activity has not been defined. Here, we provide evidence that a novel thioredoxin-like protein called thioredoxin-like 6 (TXNL6) can serve as a reducing system for MsrA repair of the essential lens chaperone α-crystallin/sHSP and mitochondrial cytochrome c. We also show that TXNL6 is induced at high levels in human lens epithelial cells exposed to H2O2-induced oxidative stress. Collectively, these data suggest a critical role for TXNL6 in MsrA repair of essential lens proteins under oxidative stress conditions and that TXNL6 is important for MsrA defense protection against cataract. They also suggest that MsrA uses multiple reducing systems for its repair activity that may augment its function under different cellular conditions
Self-assembling nanoparticles containing dexamethasone as a novel therapy in allergic airways inflammation.
Nanocarriers can deliver a wide variety of drugs, target them to sites of interest, and protect them from degradation and inactivation by the body. They have the capacity to improve drug action and decrease undesirable systemic effects. We have previously developed a well-defined non-toxic PEG-dendritic block telodendrimer for successful delivery of chemotherapeutics agents and, in these studies, we apply this technology for therapeutic development in asthma. In these proof-of-concept experiments, we hypothesized that dexamethasone contained in self-assembling nanoparticles (Dex-NP) and delivered systemically would target the lung and decrease allergic lung inflammation and airways hyper-responsiveness to a greater degree than equivalent doses of dexamethasone (Dex) alone. We found that ovalbumin (Ova)-exposed mice treated with Dex-NP had significantly fewer total cells (2.78 ± 0.44 × 10(5) (n = 18) vs. 5.98 ± 1.3 × 10(5) (n = 13), P<0.05) and eosinophils (1.09 ± 0.28 × 10(5) (n = 18) vs. 2.94 ± 0.6 × 10(5) (n = 12), p<0.05) in the lung lavage than Ova-exposed mice alone. Also, lower levels of the inflammatory cytokines IL-4 (3.43 ± 1.2 (n = 11) vs. 8.56 ± 2.1 (n = 8) pg/ml, p<0.05) and MCP-1 (13.1 ± 3.6 (n = 8) vs. 28.8 ± 8.7 (n = 10) pg/ml, p<0.05) were found in lungs of the Dex-NP compared to control, and they were not lower in the Dex alone group. In addition, respiratory system resistance was lower in the Dex-NP compared to the other Ova-exposed groups suggesting a better therapeutic effect on airways hyperresponsiveness. Taken together, these findings from early-stage drug development studies suggest that the encapsulation and protection of anti-inflammatory agents such as corticosteroids in nanoparticle formulations can improve efficacy. Further development of novel drugs in nanoparticles is warranted to explore potential treatments for chronic inflammatory diseases such as asthma
Shocked Gas in IRAS F17207-0014: ISM Collisions and Outflows
We combine optical and near-infrared AO-assisted integral field observations
of the merging ULIRG IRAS F17207-0014 from the Wide-Field Spectrograph (WiFeS)
and Keck/OSIRIS. The optical emission line ratios [N II]/H, [S
II]/H, and [O I]/H reveal a mixing sequence of shocks present
throughout the galaxy, with the strongest contributions coming from large radii
(up to 100% at 5 kpc in some directions), suggesting galactic-scale
winds. The near-infrared observations, which have approximately 30 times higher
spatial resolution, show that two sorts of shocks are present in the vicinity
of the merging nuclei: low-level shocks distributed throughout our
field-of-view evidenced by an H/Br line ratio of 0.6-4, and
strong collimated shocks with a high H/Br line ratio of
4-8, extending south from the two nuclear disks approximately 400 pc
(0.5 arcsec). Our data suggest that the diffuse shocks are caused by the
collision of the interstellar media associated with the two progenitor galaxies
and the strong shocks trace the base of a collimated outflow coming from the
nucleus of one of the two disks.Comment: accepted to MNRA
A Nurse Practitioner Model for Delivering Primary and Coordinated Care to Adults with Disabilities - CLASS Inc., Lawrence, MA and Academic Partners, Brandeis University and University of Massachusetts Lowell
The project will (1) design and plan the implementation of a nurse practitioner model for delivering primary and coordinated care to adults with disabilities who are receiving day habilitation services, and (2) evaluate the design and planning processes using a participatory and iterative approach. The project is a collaborative effort between a university-based research center, provider agencies, a nursing school, and government officials. Products include a logic model of the intervention, materials for training nurses to provide care and service coordination, and an analysis of the process to disseminate lessons learned, support a demonstration project and encourage replication efforts
Qualitative study of loneliness in a senior housing community: the importance of wisdom and other coping strategies.
ObjectiveOlder adults are at a high risk for loneliness, which impacts their health, well-being, and longevity. While related to social isolation, loneliness is a distinct, internally experienced, distressing feeling. The present qualitative study sought to identify characteristics of loneliness in older adults living independently within a senior housing community, which is typically designed to reduce social isolation.MethodSemi-structured qualitative interviews regarding the experience of loneliness, risk factors, and ways to combat it were conducted with 30 older adults, ages 65-92 years. The interviews were audiotaped, transcribed, and coded using a grounded theory analytic approach based on coding, consensus, co-occurrence, and comparison.ResultsThree main themes with multiple subthemes are described: (A) Risk and Protective factors for loneliness: age-associated losses, lack of social skills or abilities, and protective personality traits; (B) Experience of loneliness: Sadness and lack of meaning as well as Lack of motivation; and (C) Coping strategies to prevent or overcome loneliness: acceptance of aging, compassion, seeking companionship, and environment enables socialization.DiscussionDespite living within a communal setting designed to reduce social isolation, many older adults described feeling lonely in stark negative terms, attributing it to aging-associated losses or lack of social skills and abilities. However, interviewees also reported positive personal qualities and actions to prevent or cope with loneliness, several of which mirrored specific components of wisdom. The results support the reported inverse relationship between loneliness and wisdom and suggest a potential role for wisdom-enhancing interventions to reduce and prevent loneliness in older populations
Women's perceptions of their healthcare experience when they choose not to breastfeed
Research Question How do women who choose not to breastfeed perceive their healthcare experience? Method This qualitative research study used a phenomenographic approach to explore the healthcare experience of women who do not breastfeed. Seven women were interviewed about their healthcare experience relating to their choice of feeding, approximately four weeks after giving birth. Six conceptions were identified and an outcome space was developed to demonstrate the relationships and meaning of the conceptions in a visual format. Findings There were five unmet needs identified by the participants during this study. These needs included equity, self sufficiency, support, education and the need not to feel pressured. Conclusion Women in this study who chose not to breastfeed identified important areas where they felt that their needs were not met. In keeping with the Code of Ethics for Nurses and Midwives, the identified needs of women who do not breastfeed must be addressed in a caring, compassionate and just manner. The care and education of women who formula feed should be of the highest standard possible, even if the choice not to breastfeed is not the preferred choice of healthcare professionals
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