308 research outputs found

    The function and regulation of acid-sensing ion channels (ASICs) and the epithelial Na(+) channel (ENaC): IUPHAR Review 19.

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    Acid-sensing ion channels (ASICs) and the epithelial Na(+) channel (ENaC) are both members of the ENaC/degenerin family of amiloride-sensitive Na(+) channels. ASICs act as proton sensors in the nervous system where they contribute, besides other roles, to fear behaviour, learning and pain sensation. ENaC mediates Na(+) reabsorption across epithelia of the distal kidney and colon and of the airways. ENaC is a clinically used drug target in the context of hypertension and cystic fibrosis, while ASIC is an interesting potential target. Following a brief introduction, here we will review selected aspects of ASIC and ENaC function. We discuss the origin and nature of pH changes in the brain and the involvement of ASICs in synaptic signalling. We expose how in the peripheral nervous system, ASICs cover together with other ion channels a wide pH range as proton sensors. We introduce the mechanisms of aldosterone-dependent ENaC regulation and the evidence for an aldosterone-independent control of ENaC activity, such as regulation by dietary K(+) . We then provide an overview of the regulation of ENaC by proteases, a topic of increasing interest over the past few years. In spite of the profound differences in the physiological and pathological roles of ASICs and ENaC, these channels share many basic functional and structural properties. It is likely that further research will identify physiological contexts in which ASICs and ENaC have similar or overlapping roles

    Development and Validation of eRADAR: A Tool Using EHR Data to Detect Unrecognized Dementia.

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    ObjectivesEarly recognition of dementia would allow patients and their families to receive care earlier in the disease process, potentially improving care management and patient outcomes, yet nearly half of patients with dementia are undiagnosed. Our aim was to develop and validate an electronic health record (EHR)-based tool to help detect patients with unrecognized dementia (EHR Risk of Alzheimer's and Dementia Assessment Rule [eRADAR]).DesignRetrospective cohort study.SettingKaiser Permanente Washington (KPWA), an integrated healthcare delivery system.ParticipantsA total of 16 665 visits among 4330 participants in the Adult Changes in Thought (ACT) study, who undergo a comprehensive process to detect and diagnose dementia every 2 years and have linked KPWA EHR data, divided into development (70%) and validation (30%) samples.MeasurementsEHR predictors included demographics, medical diagnoses, vital signs, healthcare utilization, and medications within the previous 2 years. Unrecognized dementia was defined as detection in ACT before documentation in the KPWA EHR (ie, lack of dementia or memory loss diagnosis codes or dementia medication fills).ResultsOverall, 1015 ACT visits resulted in a diagnosis of incident dementia, of which 498 (49%) were unrecognized in the KPWA EHR. The final 31-predictor model included markers of dementia-related symptoms (eg, psychosis diagnoses, antidepressant fills), healthcare utilization pattern (eg, emergency department visits), and dementia risk factors (eg, cerebrovascular disease, diabetes). Discrimination was good in the development (C statistic = .78; 95% confidence interval [CI] = .76-.81) and validation (C statistic = .81; 95% CI = .78-.84) samples, and calibration was good based on plots of predicted vs observed risk. If patients with scores in the top 5% were flagged for additional evaluation, we estimate that 1 in 6 would have dementia.ConclusionThe eRADAR tool uses existing EHR data to detect patients with good accuracy who may have unrecognized dementia. J Am Geriatr Soc 68:103-111, 2019

    Functional Status After Colon Cancer Surgery in Elderly Nursing Home Residents

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/91352/1/jgs3915.pd

    A new approach for the heliometric optics

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    The heliometer of Fraunhofer in Koenigsberg (1824) is a refractor in which the lens is split into two halves to which is applied a linear displacement along the cut. Later in 1890s a variation of the heliometer has been realized in Goettingen using a beam splitting wedge: these methods were both subjected to chromatic and refractive aberrations; the second configuration being much less affected by thermal fluctuations. The reflector version of the heliometer conceived at the Observatorio Nacional of Rio de Janeiro overcome these problems: the two halves of the vitrified ceramic mirror split at a fixed heliometric angle produce the two images of the Sun exempt of chromatisms and distortions. The heliometer of Rio is a telescope which can rotate around its axis, to measure the solar diameter at all heliolatitudes. A further development of that heliometer, now under construction, is the annular heliometer, in which the mirrors are concentric, with symmetrical Point Spread Functions. Moreover the location of the Observatory of Rio de Janeiro allows zenithal observations, with no atmospheric refraction at all heliolatitudes, in December and January

    Testbeam and Laboratory Characterization of CMS 3D Pixel Sensors

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    The pixel detector is the innermost tracking device in CMS, reconstructing interaction vertices and charged particle trajectories. The sensors located in the innermost layers of the pixel detector must be upgraded for the ten-fold increase in luminosity expected with the High- Luminosity LHC (HL-LHC) phase. As a possible replacement for planar sensors, 3D silicon technology is under consideration due to its good performance after high radiation fluence. In this paper, we report on pre- and post- irradiation measurements for CMS 3D pixel sensors with different electrode configurations. The effects of irradiation on electrical properties, charge collection efficiency, and position resolution of 3D sensors are discussed. Measurements of various test structures for monitoring the fabrication process and studying the bulk and surface properties, such as MOS capacitors, planar and gate-controlled diodes are also presented.Comment: 14 page

    Discrimination in Healthcare Settings is Associated with Disability in Older Adults: Health and Retirement Study, 2008–2012

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    BACKGROUNDAs our society ages, improving medical care for an older population will be crucial. Discrimination in healthcare may contribute to substandard experiences with the healthcare system, increasing the burden of poor health in older adults. Few studies have focused on the presence of healthcare discrimination and its effects on older adults.OBJECTIVEWe aimed to examine the relationship between healthcare discrimination and new or worsened disability.DESIGNThis was a longitudinal analysis of data from the nationally representative Health and Retirement Study administered in 2008 with follow-up through 2012.PARTICIPANTSSix thousand and seventeen adults over the age of 50 years (mean age 67years, 56.3% female, 83.1% white) were included in this study.MAIN MEASURESHealthcare discrimination assessed by a 2008 report of receiving poorer service or treatment than other people by doctors or hospitals (never, less than a year=infrequent; more than once a year=frequent). Outcome was self-report of new or worsened disability by 2012 (difficulty or dependence in any of six activities of daily living). We used a Cox proportional hazards model adjusting for age, race/ethnicity, gender, net worth, education, depression, high blood pressure, diabetes, cancer, lung disease, heart disease, stroke, and healthcare utilization in the past 2years.KEY RESULTSIn all, 12.6 % experienced discrimination infrequently and 5.9% frequently. Almost one-third of participants (29%) reporting frequent healthcare discrimination developed new or worsened disability over 4years, compared to 16.8% of those who infrequently and 14.7% of those who never experienced healthcare discrimination (p < 0.001). In multivariate analyses, compared to no discrimination, frequent healthcare discrimination was associated with new or worsened disability over 4years (aHR = 1.63, 95% CI 1.16–2.27).CONCLUSIONSOne out of five adults over the age of 50 years experiences discrimination in healthcare settings. One in 17 experience frequent healthcare discrimination, and this is associated with new or worsened disability by 4years. Future research should focus on the mechanisms by which healthcare discrimination influences disability in older adults to promote better health outcomes for an aging population.Electronic supplementary materialThe online version of this article (doi:10.1007/s11606-015-3233-6) contains supplementary material, which is available to authorized users

    Severe hyperkalemia is rescued by low-potassium diet in renal βENaC-deficient mice.

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    In adulthood, an induced nephron-specific deficiency of αENaC (Scnn1a) resulted in pseudohypoaldosteronism type 1 (PHA-1) with sodium loss, hyperkalemia, and metabolic acidosis that is rescued through high-sodium/low-potassium (HNa &lt;sup&gt;+&lt;/sup&gt; /LK &lt;sup&gt;+&lt;/sup&gt; ) diet. In the present study, we addressed whether renal βENaC expression is required for sodium and potassium balance or can be compensated by remaining (α and γ) ENaC subunits using adult nephron-specific knockout (Scnn1b &lt;sup&gt;Pax8/LC1&lt;/sup&gt; ) mice. Upon induction, these mice present a severe PHA-1 phenotype with weight loss, hyperkalemia, and dehydration, but unlike the Scnn1a &lt;sup&gt;Pax8/LC1&lt;/sup&gt; mice without persistent salt wasting. This is followed by a marked downregulation of STE20/SPS1-related proline-alanine-rich protein kinase (SPAK) and Na &lt;sup&gt;+&lt;/sup&gt; /Cl &lt;sup&gt;-&lt;/sup&gt; co-transporter (NCC) protein expression and activity. Most of the experimental Scnn1b &lt;sup&gt;Pax8/LC1&lt;/sup&gt; mice survived with a HNa &lt;sup&gt;+&lt;/sup&gt; /LK &lt;sup&gt;+&lt;/sup&gt; diet that partly normalized NCC phosphorylation, but not total NCC expression. Since salt loss was minor, we applied a standard-sodium/LK &lt;sup&gt;+&lt;/sup&gt; diet that efficiently rescued these mice resulting in normokalemia and normalization of NCC phosphorylation, but not total NCC expression. A further switch to LNa &lt;sup&gt;+&lt;/sup&gt; /standard-K &lt;sup&gt;+&lt;/sup&gt; diet induced again a severe PHA-1-like phenotype, but with only transient salt wasting indicating that low-K &lt;sup&gt;+&lt;/sup&gt; intake is critical to decrease hyperkalemia in a NCC-dependent manner. In conclusion, while the βENaC subunit plays only a minor role in sodium balance, severe hyperkalemia results in downregulation of NCC expression and activity. Our data demonstrate the importance to primarily correct the hyperkalemia with a low-potassium diet that normalizes NCC activity

    Silicon Sensors for Future Particle Trackers

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    Several future high-energy physics facilities are currently being planned. The proposed projects include high energy e+ee^+ e^- circular and linear colliders, hadron colliders and muon colliders, while the Electron-Ion Collider (EIC) has already been approved for construction at the Brookhaven National Laboratory. Each proposal has its own advantages and disadvantages in term of readiness, cost, schedule and physics reach, and each proposal requires the design and production of specific new detectors. This paper first presents the performances required to the future silicon tracking systems at the various new facilities, and then it illustrates a few possibilities for the realization of such silicon trackers. The challenges posed by the future facilities require a new family of silicon detectors, where features such as impact ionization, radiation damage saturation, charge sharing, and analog readout are exploited to meet these new demands
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