270 research outputs found
Development of a High-Throughput Functional Screen Using Nanowell-Assisted Cell Patterning
Living-cell-based screens can facilitate lead discovery of functional therapeutics of interest. A versatile and scalable method is reported that uses dense arrays of nanowells for imparting defined patterns on monolayers of cells. It is shown that this approach can coordinate a multi-component biological assay by designing and implementing a high-throughput, functional nanoliter-scale neutralization assay to identify neutralizing antibodies against HIV.National Cancer Institute (U.S.) (P30-CA14051
Вплив жорсткості приєднаних конструкцій на стійкість балок
The work contains expressions for taking into account the effect of the shear and torsional stiffness of structures attached to the steel beam, namely profiled floor and discrete connection, on the stability factor. The article deals with the comparative analysis of methods for determining the carrying capacity by stability of the flexible I-beams, which go under bending. The complex of their advantages as well as disadvantages was revealed successfully. The offer to revise construction norms in the direction of increasing material saving was made by detailed calculation.У роботі отримано вирази для врахування впливу зсувної та крутильної жорсткості приєднаних до сталевої балки конструкцій, а саме профільованого настилу та дискретних в’язей, на коефіцієнт стійкості балки при згині, проведено порівняльний аналіз методик визначення несучої здатності за стійкістю гнучких двотаврових елементів, що зазнають впливу згину. Виявлено їх переваги та недоліки. Запропоновано переглянути будівельні норми у бік збільшення економії матеріалу шляхом деталізації розрахунку
Long-Term High-Temperature Stability of Functionalized Graphene Oxide Nanoplatelets in Arab-D and API Brine
Partially reduced graphene oxide (prGO) was covalently functionalized with a zwitterionic polymer polyzwitterionic polymer to afford a composite material with excellent dispersibility and long-term stability in high salinity brines including standard API and Arab-D found in deep oil reservoirs. When heated at 90 °C, the dispersions remained stable in excess of 140 days. These results suggest the utility of imidazolium-based polymers for brine stabilization as well as the use of diazonium containing polymers for a “grafting-to” approach to nanocarbon functionalization.Saudi Aramco (MIT Energy Initiative)Massachusetts Institute of Technology. Institute for Soldier NanotechnologiesCamille & Henry Dreyfus Foundation. Postdoctoral Program in Environmental Chemistry (Fellowship
Spectroscopic Observations of Lyman-Break Galaxies at Redshift ~ 4, 5 and 6 in the GOODS-South Field
We report on observations of Lyman-break galaxies (LBGs) selected from the
Great Observatories Origins Deep Survey at mean redshift z~4, 5 and 6, obtained
with FORS2 spectrograph at the ESO-VLT.This program has yielded spectroscopic
identifications for 114 galaxies of which 51 are at z~4, 31 at z~5, and 32 at
z~6. The adopted selection criteria are effective, identifying galaxies at the
expected redshift with minimal foreground contamination. Once selection effects
are properly accounted for, the rest-frame UV spectra of the higher-redshift
LBGs appear to be similar to their counterparts at z~3. As at z~3, LBGs at z~4
and z~5 show Lya both in emission and in absorption; when in absorption, strong
interstellar lines and red UV spectra are observed, a fact also measured at z~2
and 3. At z~6, sensitivity issues bias our sample towards galaxies with Lya in
emission; nevertheless, these spectra appear to be similar to their
lower-redshift counterparts. As in other studies at similar redshifts, we find
clear evidence that brighter LBGs tend to have weaker Lya emission lines. At
fixed rest-frame UV luminosity, the equivalent width of the Lya emission line
is larger at higher redshifts. At all redshifts where the measurements can be
reliably made, the redshift of the Lya emission line turns out to be larger
than that of the interstellar absorption lines,with a median velocity
difference DeltaV~400 km/s at z~4 and 5, consistent with results at lower
redshifts. This shows that powerful, large-scale winds are common at high
redshift.In general,there is no strong correlation between the morphology of
the UV light and the spectroscopic properties. However, galaxies with deep
interstellar absorption lines and strong Lya absorption appear to be more
diffuse than galaxies with Lya in emission.(abridged)Comment: 58 pages, 19 figures, accepted for publication in The Astrophysical
Journa
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Fabrication and evaluation of uniform and gradient density epoxies
Filled epoxy materials which vary in density in a designed manner have been fabricated and their mechanical properties evaluated. Density variations were produced by incorporating different volume fractions of either glass microballoons (GMB) or alumina. Several different sample types were evaluated including uniform density (0.8 g/cm{sup 3} < {rho} < 2.0 g/cm{sup 3}) samples and gradient density samples (GMB only, 0.8 g/cm{sup 3} < {rho} < 1.2 g/cm{sup 3}). The uniform density specimens were evaluated for the effects of filler type and concentration on modulus and toughness. Results indicated that addition of alumina filler significantly increased the resulting modulus while addition of GMB had little measurable effect. These differences could be understood in terms of the differing moduli of the additives relative to that of the epoxy matrix. In the former case the alumina particulates had a modulus much greater than that of the epoxy while in the latter case, the modulus of the GMB additive was only slightly greater than that of the matrix. Addition of either filler significantly degraded the toughness of the composite specimens and precluded the use of gradients to enhance toughness performance. Discontinuous {open_quotes}block{close_quotes} gradients used for testing were fabricated by simple sequential pours of formulations with different GMB loadings and were evaluated for modulus, strength and ductility. Continuous gradients were fabricated in process studies by programmed shifts in the peristaltic pumping/mixing ratio of epoxies filled with either alumina or GMB. None of the continuous gradient materials were mechanically tested. These results suggest that applications utilizing gradient materials containing alumina and similar high modulus fillers to provide designed stiffness rather than improved toughness are the most appropriate targets for future investigation
Automated pipeline for rapid production and screening of HIV-specific monoclonal antibodies using pichia pastoris
Monoclonal antibodies (mAbs) that bind and neutralize human pathogens have great therapeutic potential. Advances in automated screening and liquid handling have resulted in the ability to discover antigen-specific antibodies either directly from human blood or from various
combinatorial libraries (phage, bacteria or yeast). There remain, however, bottlenecks in the cloning, expression and evaluation of such lead antibodies identified in primary screens that hinder high-throughput screening. As such, ‘hit-to-lead identification’ remains both expensive and
time-consuming. By combining the advantages of overlap extension PCR (OE-PCR) and a genetically stable yet easily manipulatable microbial expression host Pichia pastoris, we have developed an automated pipeline for the rapid production and screening of full-length antigenspecific
mAbs. Here, we demonstrate the speed, feasibility and cost-effectiveness of our approach by generating several broadly neutralizing antibodies against human immunodeficiency virus (HIV).Bill & Melinda Gates FoundationUnited States. Defense Advanced Research Projects AgencySpace and Naval Warfare Systems Center San Diego (U.S.) (Contract N66001-13-C-4025)W. M. Keck FoundationNational Institute of Allergy and Infectious Diseases (U.S.) (U19AI090970).National Cancer Institute (U.S.) (David H. Koch Institute for Integrative Cancer Research at MIT. Support (Core) Grant P30-CA14051
Automated cross-identifying radio to infrared surveys using the LRPY algorithm: A case study
Cross-identifying complex radio sources with optical or infra red (IR) counterparts in surveys such as the Australia Telescope Large Area Survey (ATLAS) has traditionally been performed manually. However, with new surveys from the Australian Square Kilometre Array Pathfinder detecting many tens of millions of radio sources, such an approach is no longer feasible. This paper presents new software (LRPY - Likelihood Ratio in PYTHON) to automate the process of cross-identifying radio sources with catalogues at other wavelengths. LRPY implements the likelihood ratio (LR) technique with a modification to account for two galaxies contributing to a sole measured radio component. We demonstrate LRPY by applying it to ATLAS DR3 and a Spitzer-based multiwavelength fusion catalogue, identifying 3848 matched sources via our LR-based selection criteria. A subset of 1987 sources have flux density values for all IRAC bands which allow us to use criteria to distinguish between active galactic nuclei (AGNs) and star-forming galaxies (SFG). We find that 936 radio sources (˜47 per cent) meet both of the Lacy and Stern AGN selection criteria. Of the matched sources, 295 have spectroscopic redshifts and we examine the radio to IR flux ratio versus redshift, proposing an AGN selection criterion below the Elvis radio-loud AGN limit for this dataset. Taking the union of all three AGNs selection criteria we identify 956 as AGNs (˜48 per cent). From this dataset, we find a decreasing fraction of AGNs with lower radio flux densities consistent with other results in the literature
国際公共財の供給に関する考察(2)
4 国際公共財の基本モデル 5 新しい国際公共財の供給主体(今後の国際システムの三つのシナリオ) 6 最小協力連合 7 共同指導システムの下での国際公共財 8 おわりに
Q-LET - Quick Lensing Estimation Tool - An application to SN2003es
Q-LET is a FORTRAN 77 code that enables a quick estimate of the gravitational
lensing effects on a point- or an extended source. The user provided input
consists of the redshifts, angular positions relative to the source, mass or
velocity dispersion estimate and halo type for the lens galaxies. The
considered halo types are the Navarro-Frenk-White and the Singular Isothermal
Sphere. The code uses the so-called multiple lens-plane method to find the
magnification and intrinsic shape of the source. This method takes into account
the multiple deflections that may arise when several mass accumulations are
situated at different redshifts close to the line-of-sight.
The Q-LET code is applied to the recently discovered supernova, SN2003es,
which is likely to be of Type Ia as its host galaxy is classified as an
elliptical. We find that SN2003es is likely to have been significantly
magnified by gravitational lensing and that this should be considered in high-z
studies if this SN is to be used to determine the cosmological parameters.
Q-LET was motivated by the supernova searches, where lensing can be a
problem, but it can also be applied to any simple lens system where a quick
estimate is wanted, e.g. the single lens case.Comment: 16 pages, 5 figures. Submitted to JCAP. Software available at
http://www.physto.se/~cg/qlet/qlet.ht
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