155 research outputs found
Confinement of Monolithic Stationary Phases in Targeted Regions of 3D-Printed Titanium Devices Using Thermal Polymerization
Abstract
In this study, we have prepared thermally initiated polymeric monolithic stationary phases within discrete regions of 3D-printed titanium devices. The devices were created with controllable hot and cold regions. The monolithic stationary phases were first locally created in capillaries inserted into the channels of the titanium devices. The homogeneity of the monolith structure and the interface length were studied by scanning a capacitively coupled conductivity contactless detector (C4D) along the length of the capillary. Homogeneous monolithic structures could be obtained within a titanium device equipped with a hot and cold jacket connected to two water baths. The confinement method was optimized in capillaries. The sharpest interfaces (between monolith and empty channel) were obtained with the hot region maintained at 70 °C and the cold region at 4 or 10 °C, with the latter temperature yielding better repeatability. The optimized conditions were used to create monoliths bound directly to the walls of the titanium channels. The fabricated monoliths were successfully used to separate a mixture of four intact proteins using reversed-phase liquid chromatography. Further chromatographic characterization showed a permeability (Kf) of âŒ4 Ă 10â15 m2 and a total porosity of 60%.
Since their introduction in the chromatographic world, porous polymer monoliths have proven to be powerful separation media. These chromatographic supports have been widely applied for applications, such as microscale liquid chromatography (LC) of peptides and proteins, but have also been used in capillary electrochromatography (CEC),(1) gas chromatography (GC),(2) sample preparation,(3) and catalysis.(4) The ease of preparation of monoliths, diverse chemistry options, and high permeabilities have made them popular materials for analytical devices, such as microfluidic chips for LC. In the past decade, miniaturization has been realized by developing lab-on-a-chip solutions, where several analytical processes can be integrated within a few square centimeters. In such systems, due to the small channels and articulated geometries, the particle-packing procedure has proven to be challenging.(5) In contrast, monolithic beds are usually created in situ by free-radical polymerization of monomers in the presence of porogens and they are well-suited for chip-based separations. The proliferation of microfluidic devices has spurred new interest in polymer monoliths for applications such as enzymatic reactors(6,7) and microfluidic mixers.(8) This development has been boosted by the advent of additive manufacturing (or 3D-printing), which allows for rapid prototyping of complex structures, converting computer-aided-design (CAD) models into physical objects. Unfortunately, the use of 3D-printed analytical devices for chromatographic analysis is limited by the solvent compatibility of some materials (e.g., acrylate-based polymers) and in some cases by their transparency at the desired wavelength (e.g., UV or IR wavelengths). Several successful steps have been taken to locally photopolymerize monolithic stationary phases in discrete regions of microfluidic devices.(9â12) Heat is an alternative way to transfer energy to the monomer precursors for initiating the polymerization. However, accurate control of temperature in small confined spaces is more difficult to achieve, and so far only few steps have been taken in this direction.(13) In this work, two methods are explored to achieve confined thermal polymerization. The first approach involves direct contact (DC) between Peltier elements and the surface of a titanium device. In the second approach, recirculating jackets are used for localized heating and cooling (heating/cooling jackets, HCJ). The latter approach resembles a recirculation-based freezeâthaw valve.(14) In both approaches, defined hot (HR) and cold (CR) regions are created. We aim to fabricate poly(styrene-co-divinylbenzene) (PS-DVB) monolithic stationary phases within a 3D-printed titanium microfluidic device through polymerization at 70 °C, and to separate intact proteins using this device
Feasibility and acceptability of an oral pathology asynchronous tele-mentoring intervention: A protocol
Introduction: Oral cancer remains prevalent, despite being largely preventable. The widespread use of technology at chairside, combined with advances in electronic health record (EHR) capabilities, present opportunities to improve oral cancer screening by dentists, especially for disadvantaged patients with severe health needs. Design and methods: Using a mixed-methods approach, we will evaluate the feasibility and acceptability of integrating a tele-mentoring component into the identification of oral lesions using the following 3 methods: 1) administering provider surveys that consist of a checklist of 10 key components of the intervention based on process, and asking the dental provider subjects if each one was covered; 2) conducting semi-structured interviews informed by the Consolidated Framework for Implementation Research and the Implementation Outcomes Framework with dental resident subjects to assess specific barriers to sustaining the intervention and strategies for addressing these barriers to facilitate integration of the intervention into the routine workflow of the dental clinics; and 3) administering brief exit interviews with patient subjects regarding the acceptability of the intervention to assess satisfaction with the use of intra-oral cameras at chairside to screen for and refer patients with oral lesions and identification of these oral lesions via EHR and secure e-mail tele-mentoring with an oral pathology expert.Expected impact of the study for public health: If successful, then later clinical trials will maximize the external validity of the intervention and facilitate the widespread implementation and dissemination of the model for the teaching of dentists and residents, with the ultimate goal of improving patient care
Dirofilaria repens testicular infection in child, Italy
Testicular Dirofilaria repens infection was identified and confirmed by sequence analysis in a child in northeastern Italy. Because human dirofilariasis is emerging in southern and eastern Europe, this parasitic infection should be considered in the differential diagnosis of scrotal swelling in disease-endemic countries to avoid unnecessary interventions, such as orchiectomy
First observation of Îł rays emitted from excited states south-east of Sn132: The Ïgâ19/2âÎœf7/2 multiplet of In83132
A. Jungclaus et al. ; 6 pĂĄgs.; 4 figs. ; Rapid CommunicationsFor the first time, the Îł decay of excited states has been observed in a nucleus situated in the quadrant south-east of doubly magic Sn132, a region in which experimental information so far is limited to ground-state properties. Six Îł rays with energies of 50, 86, 103, 227, 357, and 602 keV were observed following the ÎČ-delayed neutron emission from Cd85133, populated in the projectile fission of a U238 beam at the Radioactive Isotope Beam Factory at RIKEN within the EURICA project. The new experimental information is compared to the results of a modern realistic shell-model calculation, the first one in this region very far from stability, focusing in particular on the Ï0g9/2-1 - Îœ1f7/2 particle-hole multiplet in In83132. In addition, theoretical estimates based on a scaling of the two-body matrix elements for the Ïh11/2-1 - Îœg9/2 analog multiplet in Tl127208, one major proton and one major neutron shell above, are presented. ©2016 American Physical SocietyWe thank the staff of the RIKEN Nishina Center accelerator
complex for providing stable beams with high intensities to
the experiment. We acknowledge the EUROBALL Owners
Committee for the loan of germanium detectors and the
PreSpec Collaboration for the readout electronics of the
cluster detectors. This work was supported by the Spanish
Ministerio de Ciencia e InnovaciĂłn under Contract No.
FPA2011-29854-C04 and the Spanish Ministerio de EconomĂa
y Competitividad under Contract No. FPA2014-57196-C5-
4-P, the Generalitat Valenciana (Spain) under Grant No.
PROMETEO/2010/101, the National Research Foundation of
Korea (NRF) grant funded by the Korea government (MEST)
(No. NRF-2012R1A1A1041763), the Priority Centers Research
Program in Korea (2009-0093817), OTKA Contract
No. K-100835, JSPS KAKENHI (Grant No. 25247045), the
European Commission through the Marie Curie Actions call
PEOPLE-2011FP7-IEF under Contract No. 300096 and the
German BMBF (No. 05P12RDCIA and No. 05P12RDNUP),
and Helmholtz International Center for FAIR.Peer Reviewe
ÎČ decay of 129Cd and excited states in 129In
J. Taprogge et al.; 11 pags.; 8 figs.; 2 tabs.; PACS number(s): 23.20.Lv, 23.40.âs, 21.60.Cs, 27.60.+j©2015 American Physical Society. The ÎČ decay of 129Cd, produced in the relativistic fission of a 238U beam, was experimentally studied at the
RIBF facility at the RIKEN Nishina Center. From the Îł radiation emitted after the ÎČ decays, a level scheme of 129In was established comprising 31 excited states and 69 Îł -ray transitions. The experimentally determined level
energies are compared to state-of-the-art shell-model calculations. The half-lives of the two ÎČ-decaying states in 129Cd were deduced and the ÎČ feeding to excited states in 129In were analyzed. It is found that, as in most cases
in the Z < 50, N 82 region, both decays are dominated by the Îœ0g7/2 â Ï0g9/2 GamowâTeller transition,
although the contribution of first-forbidden transitions cannot be neglected.This work was supported
by the Spanish Ministerio de Ciencia e Innovacion
under contracts FPA2009-13377-C02 and FPA2011-29854-
C04, the Generalitat Valenciana (Spain) under grant PROMETEO/2010/101,
the National Research Foundation of Korea
(NRF) grant funded by the Korea government (MEST) (No.
NRF-2012R1A1A1041763), the Priority Centers Research
Program in Korea (2009-0093817), OTKA contract number
K-100835, JSPS KAKENHI (Grant No. 25247045), the
European Commission through the Marie Curie Actions call
FP7-PEOPLE-2011-IEF under Contract No. 300096, the US
Department of Energy, Office of Nuclear Physics, under
Contract No. DE-AC02-06CH11357, the âRIKEN foreign
research program,â and the German BMBF (No. 05P12RDCIA
and 05P12RDNUP) and HIC for FAIR.Peer Reviewe
Language production impairments in patients with a first episode of psychosis
Language production has often been described as impaired in psychiatric diseases such as in psychosis. Nevertheless, little is known about the characteristics of linguistic difficulties and their relation with other cognitive domains in patients with a first episode of psychosis (FEP), either affective or non-affective. To deepen our comprehension of linguistic profile in FEP, 133 patients with FEP (95 non-affective, FEP-NA; 38 affective, FEP-A) and 133 healthy controls (HC) were assessed with a narrative discourse task. Speech samples were systematically analyzed with a well-established multilevel procedure investigating both micro- (lexicon, morphology, syntax) and macro-linguistic (discourse coherence, pragmatics) levels of linguistic processing. Executive functioning and IQ were also evaluated. Both linguistic and neuropsychological measures were secondarily implemented with a machine learning approach in order to explore their predictive accuracy in classifying participants as FEP or HC. Compared to HC, FEP patients showed language production difficulty at both micro- and macro-linguistic levels. As for the former, FEP produced shorter and simpler sentences and fewer words per minute, along with a reduced number of lexical fillers, compared to HC. At the macro-linguistic level, FEP performance was impaired in local coherence, which was paired with a higher percentage of utterances with semantic errors. Linguistic measures were not correlated with any neuropsychological variables. No significant differences emerged between FEP-NA and FEP-A (pâ„0.02, after Bonferroni correction). Machine learning analysis showed an accuracy of group prediction of 76.36% using language features only, with semantic variables being the most impactful. Such a percentage was enhanced when paired with clinical and neuropsychological variables. Results confirm the presence of language production deficits already at the first episode of the illness, being such impairment not related to other cognitive domains. The high accuracy obtained by the linguistic set of features in classifying groups support the use of machine learning methods in neuroscience investigations
A population of gamma-ray emitting globular clusters seen with the Fermi Large Area Telescope
Globular clusters with their large populations of millisecond pulsars (MSPs)
are believed to be potential emitters of high-energy gamma-ray emission. Our
goal is to constrain the millisecond pulsar populations in globular clusters
from analysis of gamma-ray observations. We use 546 days of continuous
sky-survey observations obtained with the Large Area Telescope aboard the Fermi
Gamma-ray Space Telescope to study the gamma-ray emission towards 13 globular
clusters. Steady point-like high-energy gamma-ray emission has been
significantly detected towards 8 globular clusters. Five of them (47 Tucanae,
Omega Cen, NGC 6388, Terzan 5, and M 28) show hard spectral power indices and clear evidence for an exponential cut-off in the range
1.0-2.6 GeV, which is the characteristic signature of magnetospheric emission
from MSPs. Three of them (M 62, NGC 6440 and NGC 6652) also show hard spectral
indices , however the presence of an exponential cut-off
can not be unambiguously established. Three of them (Omega Cen, NGC 6388, NGC
6652) have no known radio or X-ray MSPs yet still exhibit MSP spectral
properties. From the observed gamma-ray luminosities, we estimate the total
number of MSPs that is expected to be present in these globular clusters. We
show that our estimates of the MSP population correlate with the stellar
encounter rate and we estimate 2600-4700 MSPs in Galactic globular clusters,
commensurate with previous estimates. The observation of high-energy gamma-ray
emission from a globular cluster thus provides a reliable independent method to
assess their millisecond pulsar populations that can be used to make
constraints on the original neutron star X-ray binary population, essential for
understanding the importance of binary systems in slowing the inevitable core
collapse of globular clusters.Comment: Accepted for publication in A&A. Corresponding authors: J.
Kn\"odlseder, N. Webb, B. Pancraz
Fermi Large Area Telescope Constraints on the Gamma-ray Opacity of the Universe
The Extragalactic Background Light (EBL) includes photons with wavelengths
from ultraviolet to infrared, which are effective at attenuating gamma rays
with energy above ~10 GeV during propagation from sources at cosmological
distances. This results in a redshift- and energy-dependent attenuation of the
gamma-ray flux of extragalactic sources such as blazars and Gamma-Ray Bursts
(GRBs). The Large Area Telescope onboard Fermi detects a sample of gamma-ray
blazars with redshift up to z~3, and GRBs with redshift up to z~4.3. Using
photons above 10 GeV collected by Fermi over more than one year of observations
for these sources, we investigate the effect of gamma-ray flux attenuation by
the EBL. We place upper limits on the gamma-ray opacity of the Universe at
various energies and redshifts, and compare this with predictions from
well-known EBL models. We find that an EBL intensity in the optical-ultraviolet
wavelengths as great as predicted by the "baseline" model of Stecker et al.
(2006) can be ruled out with high confidence.Comment: 42 pages, 12 figures, accepted version (24 Aug.2010) for publication
in ApJ; Contact authors: A. Bouvier, A. Chen, S. Raino, S. Razzaque, A.
Reimer, L.C. Reye
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