5,849 research outputs found
Effects of zinc supplementation on cognitive function in healthy middle-aged and older adults: the ZENITH study
A randomised double-blind placebo-controlled design was employed to investigate the effects of Zn supplementation on cognitive function in 387 healthy adults aged 55ā87 years. Several measures of visual memory, working memory, attention and reaction time were obtained using the Cambridge Automated Neuropsychological Test Battery at baseline and then after 3 and 6 months of 0 (placebo), 15 or 30 mg Zn/d. Younger adults (70 years), and performance improved with practice on some measures. For two out of eight dependent variables, there were significant interactions indicating a beneficial effect (at 3 months only) of both 15 and 30 mg/d on one measure of spatial working memory and a detrimental effect of 15 mg/d on one measure of attention. Further work is required to establish whether these findings generalise to older adults in poorer mental and physical health and with less adequate Zn intake and status than the present sample
Multiple Use SiPM Integrated Circuit (MUSIC) for Large Area and High Performance Sensors
The 8-channel Multiple Use Silicon Photo-multiplier (SiPM) Integrated Circuit (MUSIC) Application specific integrated circuit (ASIC) for SiPM anode readout has been designed for applications where large photo-detection areas are required. MUSIC offers three main features: (1) Sum of the eight input channels using a differential output driver, (2) eight individual single ended (SE) analog outputs, and (3) eight individual SE binary outputs using a time over threshold technique. Each functionality, summation and individual readout includes a selectable dual-gain configuration. Moreover, the signal sum implements a dual-gain output providing a 15-bit dynamic range. The circuit contains a tunable pole zero cancellation of the SiPM recovery time constant to deal with most of the available SiPM devices in the market. Experimental tests show how MUSIC can linearly sum signals from different SiPMs and distinguish even a few photons. Additionally, it provides a single photon output pulse width at half maximum (FWHM) between 5-10 ns for the analog output and a single-photon time resolution (SPTR) around 118 ps sigma using a Hamamatsu SiPM S13360-3075CS for the binary output. Lastly, the summation mode has a power consumption of approximate to 200 mW, whereas the individual readout consumes approximate to 30 mW/ch
Effects of acute and repeated treatment with methocinnamox, a mu opioid receptor antagonist, on fentanyl self-administration in rhesus monkeys
Methocinnamox (MCAM), a mu opioid receptor antagonist with a long duration of action, attenuates heroin self-administration in rhesus monkeys, suggesting it could be an effective treatment for opioid use disorder (OUD). This study examined effects of acute and repeated MCAM administration on self-administration of the high-efficacy mu opioid receptor agonist fentanyl and characterized MCAM pharmacokinetics. Four rhesus monkeys self-administered i.v. infusions of fentanyl (0.00032āmg/kg/infusion) or cocaine (0.032āmg/kg/infusion). MCAM (0.1ā0.32āmg/kg) or the opioid receptor antagonist naltrexone (0.001ā0.032āmg/kg) was injected prior to test sessions to evaluate acute effects. On a separate occasion, 0.32āmg/kg MCAM was injected every 12 days for 5 total injections to evaluate the effectiveness of repeated treatment. Following acute injection, MCAM and naltrexone decreased fentanyl self-administration on the day of treatment, with attenuation lasting for up to 2 weeks after the larger MCAM dose and <1 day after naltrexone. Repeated MCAM administration decreased fentanyl self-administration for more than 2 months without altering cocaine self-administration. MCAM plasma concentrations peaked 15ā45āmin after injection, with a half-life ranging from 13.7 to 199.8āmin, and decreased markedly 1 day after injection. MCAM selectively reduced opioid self-administration and remained effective with repeated administration. Moreover, MCAM was effective at times when plasma levels were very low, suggesting that pharmacodynamic (i.e., pseudoirreversible binding to mu opioid receptors) and not pharmacokinetic factors play a significant role in its long-lasting effects. Taken together with previous studies, these data indicate that MCAM could be a safe, effective, and long-acting treatment for OUD
MATRIX16: A 16-Channel Low-Power TDC ASIC with 8 ps Time Resolution
This paper presents a highly configurable 16-channel TDC ASIC designed in a commercial 180 nm technology with the following features: time-of-flight and time-over-threshold measurements, 8.6 ps LSB, 7.7 ps jitter, 5.6 ps linearity error, up to 5 MHz of sustained input rate per channel, 9.1 mW of power consumption per channel, and an area of 4.57 mm2 . The main contributions of this work are the novel design of the clock interpolation circuitry based on a resistive interpolation mesh circuit and the capability to operate at different supply voltages and operating frequencies, thus providing a compromise between TDC resolution and power consumption. Keywords: TDC; time-to-digital converter; fast timing; PET; VLSI; ASIC; ToF; ToT; low power; frontend electronic
Bad metallic transport in a cold atom Fermi-Hubbard system
Charge transport is a revealing probe of the quantum properties of materials.
Strong interactions can blur charge carriers resulting in a poorly understood
"quantum soup". Here we study the conductivity of the Fermi-Hubbard model, a
testing ground for strong interaction physics, in a clean quantum system -
ultracold Li in a 2D optical lattice. We determine the charge diffusion
constant in our system by measuring the relaxation of an imposed density
modulation and modeling its decay hydrodynamically. The diffusion constant is
converted to a resistivity, which exhibits a linear temperature dependence and
exceeds the Mott-Ioffe-Regel limit, two characteristic signatures of a bad
metal. The techniques we develop here may be applied to measurements of other
transport quantities, including the optical conductivity and thermopower
Stage-specific sensitivity to p53 restoration during lung cancer progression
2011 May 25Tumorigenesis is a multistep process that results from the sequential accumulation of mutations in key oncogene and tumour suppressor pathways. Personalized cancer therapy that is based on targeting these underlying genetic abnormalities presupposes that sustained inactivation of tumour suppressors and activation of oncogenes is essential in advanced cancers. Mutations in the p53 tumour-suppressor pathway are common in human cancer and significant efforts towards pharmaceutical reactivation of defective p53 pathways are underway1, 2, 3. Here we show that restoration of p53 in established murine lung tumours leads to significant but incomplete tumour cell loss specifically in malignant adenocarcinomas, but not in adenomas. We define amplification of MAPK signalling as a critical determinant of malignant progression and also a stimulator of Arf tumour-suppressor expression. The response to p53 restoration in this context is critically dependent on the expression of Arf. We propose that p53 not only limits malignant progression by suppressing the acquisition of alterations that lead to tumour progression, but also, in the context of p53 restoration, responds to increased oncogenic signalling to mediate tumour regression. Our observations also underscore that the p53 pathway is not engaged by low levels of oncogene activity that are sufficient for early stages of lung tumour development. These data suggest that restoration of pathways important in tumour progression, as opposed to initiation, may lead to incomplete tumour regression due to the stage-heterogeneity of tumour cell populations.National Cancer Institute (U.S.) (Cancer Center Support Grant P30-CA14051)American Cancer Society (New England Area Fellow)Leukemia & Lymphoma Society of America (Fellow)Massachusetts Institute of Technology. Undergraduate Research Program (John Reed Fund)Damon Runyon Cancer Research Foundation (Merck Fellow)Genentech, Inc. (Postdoctoral Fellow)Howard Hughes Medical Institut
Interleukin 10 and Heart Fatty Acid-Binding Protein as Early Outcome Predictors in Patients With Traumatic Brain Injury
Background: Patients with traumatic brain injury (TBI) exhibit a variable and unpredictable outcome. The proteins interleukin 10 (IL-10) and heart fatty acid-binding protein (H-FABP) have shown predictive values for the presence of intracranial lesions. Aim: To evaluate the individual and combined outcome prediction ability of IL-10 and H-FABP, and to compare them to the more studied proteins S100Ī², glial fibrillary acidic protein (GFAP), and neurofilament light (NF-L), both with and without clinical predictors. Methods: Blood samples from patients with acute TBI (all severities) were collected <24 h post trauma. The outcome was measured >6 months post injury using the Glasgow Outcome Scale Extended (GOSE) score, dichotomizing patients into: (i) those with favorable (GOSEā„5)/unfavorable outcome (GOSE ā¤ 4) and complete (GOSE = 8)/incomplete (GOSE ā¤ 7) recovery, and (ii) patients with mild TBI (mTBI) and patients with TBIs of all severities. Results: When sensitivity was set at 95-100%, the proteins' individual specificities remained low. H-FABP showed the best specificity (%) and sensitivity (100%) in predicting complete recovery in patients with mTBI. IL-10 had the best specificity (50%) and sensitivity (96%) in identifying patients with favorable outcome in patients with TBIs of all severities. When individual proteins were combined with clinical parameters, a model including H-FABP, NF-L, and ISS yielded a specificity of 56% and a sensitivity of 96% in predicting complete recovery in patients with mTBI. In predicting favorable outcome, a model consisting IL-10, age, and TBI severity reached a specificity of 80% and a sensitivity of 96% in patients with TBIs of all severities. Conclusion: Combining novel TBI biomarkers H-FABP and IL-10 with GFAP, NF-L and S100Ī² and clinical parameters improves outcome prediction models in TBI.</p
INTERLEUKIN 10 AND HEART FATTY-ACID BINDING PROTEIN AS EARLY OUTCOME PREDICTORS IN PATIENTS WITH TRAUMATIC BRAIN INJURY
Background: Patients with traumatic brain injury (TBI) exhibit a variable and unpredictable outcome. The proteins interleukin 10 (IL-10) and heart fatty acid-binding protein (H-FABP) have shown predictive values for the presence of intracranial lesions. Aim: To evaluate the individual and combined outcome prediction ability of IL-10 and H-FABP, and to compare them to the more studied proteins S100Ī², glial fibrillary acidic protein (GFAP), and neurofilament light (NF-L), both with and without clinical predictors. Methods: Blood samples from patients with acute TBI (all severities) were collected 6 months post injury using the Glasgow Outcome Scale Extended (GOSE) score, dichotomizing patients into: (i) those with favorable (GOSEā„5)/unfavorable outcome (GOSE ā¤ 4) and complete (GOSE = 8)/incomplete (GOSE ā¤ 7) recovery, and (ii) patients with mild TBI (mTBI) and patients with TBIs of all severities. Results: When sensitivity was set at 95ā100%, the proteins' individual specificities remained low. H-FABP showed the best specificity (%) and sensitivity (100%) in predicting complete recovery in patients with mTBI. IL-10 had the best specificity (50%) and sensitivity (96%) in identifying patients with favorable outcome in patients with TBIs of all severities. When individual proteins were combined with clinical parameters, a model including H-FABP, NF-L, and ISS yielded a specificity of 56% and a sensitivity of 96% in predicting complete recovery in patients with mTBI. In predicting favorable outcome, a model consisting IL-10, age, and TBI severity reached a specificity of 80% and a sensitivity of 96% in patients with TBIs of all severities. Conclusion: Combining novel TBI biomarkers H-FABP and IL-10 with GFAP, NF-L and S100Ī² and clinical parameters improves outcome prediction models in TBI
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