1,068 research outputs found
A new multiplex real-time PCR test for HSV1/2 and syphilis: an evaluation of its impact in the laboratory and clinical setting
Singular solutions of fully nonlinear elliptic equations and applications
We study the properties of solutions of fully nonlinear, positively
homogeneous elliptic equations near boundary points of Lipschitz domains at
which the solution may be singular. We show that these equations have two
positive solutions in each cone of , and the solutions are unique
in an appropriate sense. We introduce a new method for analyzing the behavior
of solutions near certain Lipschitz boundary points, which permits us to
classify isolated boundary singularities of solutions which are bounded from
either above or below. We also obtain a sharp Phragm\'en-Lindel\"of result as
well as a principle of positive singularities in certain Lipschitz domains.Comment: 41 pages, 2 figure
The Victorian Newsletter (Fall 1981)
The Victorian Newsletter is sponsored for the Victorian Group of Modern Language Association by the Western Kentucky University and is published twice annually.Tennyson and Carlyle: A Source for "The Eagle" / Paul F. Mattheisen -- The Schooling of John Bull: Form and Moral in Talbot Baines Reed's Boys' Stories and in Kipling's Stalky & Co. / Patrick Scott -- How It Struck A Contemporary: Tennyson's "Lancelot and Elaine" and Pre-Raphaelite Art / Catherine Barnes Stevenson -- Amours de Voyage and Matthew Arnold in Love: An Inquiry / Eugene R. August -- Tennyson's "Ulysses" as Rhetorical Monologue / Mary Saunders -- The Mathematical References to the Adoption of the Gregorian Calendar in Lewis Carroll's Alice's Adventures in Wonderland / Laurence Dreyer -- Self-Helpers and Self-Seekers: Some Changing Attitudes to Wealth, 1840-1910 / J. L. Winte
Control of interjoint coordination during the swing phase of normal gait at different speeds
BACKGROUND: It has been suggested that the control of unconstrained movements is simplified via the imposition of a kinetic constraint that produces dynamic torques at each moving joint such that they are a linear function of a single motor command. The linear relationship between dynamic torques at each joint has been demonstrated for multijoint upper limb movements. The purpose of the current study was to test the applicability of such a control scheme to the unconstrained portion of the gait cycle – the swing phase. METHODS: Twenty-eight neurologically normal individuals walked along a track at three different speeds. Angular displacements and dynamic torques produced at each of the three lower limb joints (hip, knee and ankle) were calculated from segmental position data recorded during each trial. We employed principal component (PC) analysis to determine (1) the similarity of kinematic and kinetic time series at the ankle, knee and hip during the swing phase of gait, and (2) the effect of walking speed on the range of joint displacement and torque. RESULTS: The angular displacements of the three joints were accounted for by two PCs during the swing phase (Variance accounted for – PC1: 75.1 ± 1.4%, PC2: 23.2 ± 1.3%), whereas the dynamic joint torques were described by a single PC (Variance accounted for – PC1: 93.8 ± 0.9%). Increases in walking speed were associated with increases in the range of motion and magnitude of torque at each joint although the ratio describing the relative magnitude of torque at each joint remained constant. CONCLUSION: Our results support the idea that the control of leg swing during gait is simplified in two ways: (1) the pattern of dynamic torque at each lower limb joint is produced by appropriately scaling a single motor command and (2) the magnitude of dynamic torque at all three joints can be specified with knowledge of the magnitude of torque at a single joint. Walking speed could therefore be altered by modifying a single value related to the magnitude of torque at one joint
Probing the Balance of AGN and Star-Forming Activity in the Local Universe with ChaMP
The combination of the SDSS and the Chandra Multiwavelength Project (ChaMP)
currently offers the largest and most homogeneously selected sample of nearby
galaxies for investigating the relation between X-ray nuclear emission, nebular
line-emission, black hole masses, and properties of the associated stellar
populations. We present here novel constraints that both X-ray luminosity Lx
and X-ray spectral energy distribution bring to the galaxy evolutionary
sequence H II -> Seyfert/Transition Object -> LINER -> Passive suggested by
optical data. In particular, we show that both Lx and Gamma, the slope of the
power-law that best fits the 0.5 - 8 keV spectra, are consistent with a clear
decline in the accretion power along the sequence, corresponding to a softening
of their spectra. This implies that, at z ~ 0, or at low luminosity AGN levels,
there is an anti-correlation between Gamma and L/Ledd, opposite to the trend
exhibited by high z AGN (quasars). The turning point in the Gamma -L/Ledd LLAGN
+ quasars relation occurs near Gamma ~ 1.5 and L/Ledd ~ 0.01. Interestingly,
this is identical to what stellar mass X-ray binaries exhibit, indicating that
we have probably found the first empirical evidence for an intrinsic switch in
the accretion mode, from advection-dominated flows to standard (disk/corona)
accretion modes in supermassive black hole accretors, similar to what has been
seen and proposed to happen in stellar mass black hole systems. The
anti-correlation we find between Gamma and L/Ledd may instead indicate that
stronger accretion correlates with greater absorption. Therefore the trend for
softer spectra toward more luminous, high redshift, and strongly accreting
AGN/quasars could simply be the result of strong selection biases reflected in
the dearth of type 2 quasar detections.Comment: 23 pages, 8 figures, 1 long (3 page) table, to appear in Ap
The INTEGRAL/IBIS AGN catalogue I: X-ray absorption properties versus optical classification
In this work we present the most comprehensive INTEGRAL AGN sample which
lists 272 objects. Here we mainly use this sample to study the absorption
properties of active galaxies, to probe new AGN classes and to test the AGN
unification scheme. We find that half (48%) of the sample is absorbed while the
fraction of Compton thick AGN is small (~7%). In line with our previous
analysis, we have however shown that when the bias towards heavily absorbed
objects which are lost if weak and at large distance is removed, as it is
possible in the local Universe, the above fractions increase to become 80% and
17%. We also find that absorption is a function of source luminosity, which
implies some evolution in the obscuration properties of AGN. Few peculiar
classes, so far poorly studied in the hard X-ray band, have been detected and
studied for the first time such as 5 XBONG, 5 type 2 QSOs and 11 LINERs. In
terms of optical classification, our sample contains 57% of type 1 and 43% of
type 2 AGN; this subdivision is similar to that found in X-rays if unabsorbed
versus absorbed objects are considered, suggesting that the match between
optical and X-ray classification is overall good. Only a small percentage of
sources (12%) does not fulfill the expectation of the unified theory as we find
22 type 1 AGN which are absorbed and 10 type 2 AGN which are unabsorbed.
Studying in depth these outliers we found that most of the absorbed type 1 AGN
have X-ray spectra characterized by either complex or warm/ionized absorption
more likely due to ionized gas located in an accretion disk wind or in the
biconical structure associated to the central nucleus, therefore unrelated to
the toroidal structure. Among 10 type 2 AGN which resulted to be unabsorbed, at
most 3-4% is still eligible to be classified as a "true" type 2 AGN.Comment: 21 pages, 6 figures, 5 tables. Accepted for publication on MNRAS.
arXiv admin note: text overlap with arXiv:0709.2077 by other author
Development and implementation of ISAR, a new synthesis platform for radiopharmaceutical production
Abstract
Background
PET radiopharmaceutical development and the implementation of a production method on a synthesis module is a complex and time-intensive task since new synthesis methods must be adapted to the confines of the synthesis platform in use. Commonly utilized single fluid bus architectures put multiple constraints on synthesis planning and execution, while conventional microfluidic solutions are limited by compatibility at the macro-to-micro interface. In this work we introduce the ISAR synthesis platform and custom-tailored fluid paths leveraging up to 70 individually addressable valves on a chip-based consumable. The ISAR synthesis platform replaces traditional stopcock valve manifolds with a fluidic chip that integrates all fluid paths (tubing) and valves into one consumable and enables channel routing without the single fluid bus constraint. ISAR can scale between the macro- (10 mL), meso- (0.5 mL) and micro- (≤0.05 mL) domain seamlessly, addressing the macro-to-micro interface challenge and enabling custom tailored fluid circuits for a given application. In this paper we demonstrate proof-of-concept by validating a single chip design to address the challenge of synthesizing multiple batches of [13N]NH3 for clinical use throughout the workday.
Results
ISAR was installed at an academic PET Center and used to manufacture [13N]NH3 in > 96% radiochemical yield. Up to 9 batches were manufactured with a single consumable chip having parallel paths without the need to open the hot-cell. Quality control testing confirmed the ISAR-based [13N]NH3 met existing clinical release specifications, and utility was demonstrated by imaging a rodent with [13N]NH3 produced on ISAR.
Conclusions
ISAR represents a new paradigm in radiopharmaceutical production. Through a new system architecture, ISAR integrates the principles of microfluidics with the standard volumes and consumables established in PET Centers all over the world. Proof-of-concept has been demonstrated through validation of a chip design for the synthesis of [13N]NH3 suitable for clinical use.https://deepblue.lib.umich.edu/bitstream/2027.42/152186/1/41181_2019_Article_77.pd
The association of health literacy with adherence in older 2 adults, and its role in interventions: a systematic meta-review
Background: Low health literacy is a common problem among older adults. It is often suggested to be associated with poor adherence. This suggested association implies a need for effective adherence interventions in low health literate people. However, previous reviews show mixed results on the association between low health literacy and poor adherence. A systematic meta-review of systematic reviews was conducted to study the association between health literacy and adherence in adults above the age of 50. Evidence for the effectiveness of adherence interventions among adults in this older age group with low health literacy was also explored. Methods: Eight electronic databases (MEDLINE, ERIC, EMBASE, PsycINFO, CINAHL, DARE, the Cochrane Library, and Web of Knowledge) were searched using a variety of keywords regarding health literacy and adherence. Additionally, references of identified articles were checked. Systematic reviews were included if they assessed the association between health literacy and adherence or evaluated the effectiveness of interventions to improve adherence in adults with low health literacy. The AMSTAR tool was used to assess the quality of the included reviews. The selection procedure, data-extraction, and quality assessment were performed by two independent reviewers. Seventeen reviews were selected for inclusion. Results: Reviews varied widely in quality. Both reviews of high and low quality found only weak or mixed associations between health literacy and adherence among older adults. Reviews report on seven studies that assess the effectiveness of adherence interventions among low health literate older adults. The results suggest that some adherence interventions are effective for this group. The interventions described in the reviews focused mainly on education and on lowering the health literacy demands of adherence instructions. No conclusions could be drawn about which type of intervention could be most beneficial for this population. Conclusions: Evidence on the association between health literacy and adherence in older adults is relatively weak. Adherence interventions are potentially effective for the vulnerable population of older adults with low levels of health literacy, but the evidence on this topic is limited. Further research is needed on the association between health literacy and general health behavior, and on the effectiveness of interventions
Increased S-nitrosylation and proteasomal degradation of caspase-3 during infection contribute to the persistence of adherent invasive escherichia coli (AIEC) in immune cells
Adherent invasive Escherichia coli (AIEC) have been implicated as a causative agent of Crohn's disease (CD) due to their isolation from the intestines of CD sufferers and their ability to persist in macrophages inducing granulomas. The rapid intracellular multiplication of AIEC sets it apart from other enteric pathogens such as Salmonella Typhimurium which after limited replication induce programmed cell death (PCD). Understanding the response of infected cells to the increased AIEC bacterial load and associated metabolic stress may offer insights into AIEC pathogenesis and its association with CD. Here we show that AIEC persistence within macrophages and dendritic cells is facilitated by increased proteasomal degradation of caspase-3. In addition S-nitrosylation of pro- and active forms of caspase-3, which can inhibit the enzymes activity, is increased in AIEC infected macrophages. This S-nitrosylated caspase-3 was seen to accumulate upon inhibition of the proteasome indicating an additional role for S-nitrosylation in inducing caspase-3 degradation in a manner independent of ubiquitination. In addition to the autophagic genetic defects that are linked to CD, this delay in apoptosis mediated in AIEC infected cells through increased degradation of caspase-3, may be an essential factor in its prolonged persistence in CD patients
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