1,342 research outputs found
Enhanced uptake of nanoparticle drug carriers via a thermoresponsive shell enhances cytotoxicity in a cancer cell line
Polymer particles consisting of a biodegradable poly[lactide-co-glycolide] (PLGA) core and a thermoresponsive shell have been formulated to encapsulate the dye rhodamine 6G and the potent cytotoxic drug paclitaxel. Cellular uptake of these particles is significantly enhanced above the thermal transition temperature (TTT) of the polymer shells in the human breast carcinoma cell line MCF-7 as determined by flow cytometry and fluorescence microscopy. Paclitaxel-loaded particles display reduced and enhanced cytotoxicity below and above the TTT respectively compared to unencapsulated drug. The data suggests a potential route to enhanced anti-cancer efficacy through temperature-mediated cell targeting.© The Royal Society of Chemistry 2013
Carbon monoxide measurements at Mace Head, Ireland
The North Atlantic Ocean is bordered by continents which may each, under the influence of seasonal weather patterns, act as sources of natural and anthropogenic trace gas and particulate species. Photochemically active species such as carbon monoxide (CO) react to form ozone (O3), a species of critical importance in global climate change. CO is sparingly soluble in water, and the relatively long lifetime of CO in the troposphere makes this species an ideal tracer of air masses with origin over land. We have measured CO using a nondispersive infrared gas filter correlation analyzer at Mace Head on the west coast of Ireland nearly continuously since August 9, 1991. Measurements of CO were acquired at 20-sec resolution and recorded as 60-sec averages. Daily, monthly, and diurnal variation data characteristics of CO mixing ratios observed at this site are reported. Depending on source regions of air parcels passing over this site, 60-min concentrations of CO range from clean air values of approximately 90 ppbv to values in excess of 300 ppbv. Data characterizing the correlation between 60-min CO and O3 mixing ratio data observed at this site are reported also
New apparatus for DTA at 2000 bar: thermodynamic studies on Au, Ag, Al and HTSC oxides
A new DTA (Differential Thermal Analysis) device was designed and installed
in a Hot Isostatic Pressure (HIP) furnace in order to perform high-pressure
thermodynamic investigations up to 2 kbar and 1200C. Thermal analysis can be
carried out in inert or oxidising atmosphere up to p(O2) = 400 bar. The
calibration of the DTA apparatus under pressure was successfully performed
using the melting temperature (Tm) of pure metals (Au, Ag and Al) as standard
calibration references. The thermal properties of these metals have been
studied under pressure. The values of DV (volume variation between liquid and
solid at Tm), ROsm (density of the solid at Tm) and ALPHAm (linear thermal
expansion coefficient at Tm) have been extracted. A very good agreement was
found with the existing literature and new data were added. This HP-DTA
apparatus is very useful for studying the thermodynamics of those systems where
one or more volatile elements are present, such as high TC superconducting
oxides. DTA measurements have been performed on Bi,Pb(2223) tapes up to 2 kbar
under reduced oxygen partial pressure (p(O2) = 0.07 bar). The reaction leading
to the formation of the 2223 phase was found to occur at higher temperatures
when applying pressure: the reaction DTA peak shifted by 49C at 2 kbar compared
to the reaction at 1 bar. This temperature shift is due to the higher stability
of the Pb-rich precursor phases under pressure, as the high isostatic pressure
prevents Pb from evaporating.Comment: 6 figures, 3 tables, Thermodynamics, Thermal property, Bi-2223,
fundamental valu
Finite temperature bosonization
Finite temperature properties of a non-Fermi liquid system is one of the most
challenging probelms in current understanding of strongly correlated electron
systems. The paradigmatic arena for studying non-Fermi liquids is in one
dimension, where the concept of a Luttinger liquid has arisen. The existence of
a critical point at zero temperature in one dimensional systems, and the fact
that experiments are all undertaken at finite temperature, implies a need for
these one dimensional systems to be examined at finite temperature.
Accordingly, we extended the well-known bosonization method of one dimensional
electron systems to finite temperatures. We have used this new bosonization
method to calculate finite temperature asymptotic correlation functions for
linear fermions, the Tomonaga-Luttinger model, and the Hubbard model.Comment: REVTex, 48 page
Implementation Challenges Using a Novel Method for Collecting Patient-Reported Outcomes After Injury
Molecular Genetics of T Cell Development
T cell development is guided by a complex set of transcription factors that act recursively, in different combinations, at each of the developmental choice points from T-lineage specification to peripheral T cell specialization. This review describes the modes of action of the major T-lineage-defining transcription factors and the signal pathways that activate them during intrathymic differentiation from pluripotent precursors. Roles of Notch and its effector RBPSuh (CSL), GATA-3, E2A/HEB and Id proteins, c-Myb, TCF-1, and members of the Runx, Ets, and Ikaros families are critical. Less known transcription factors that are newly recognized as being required for T cell development at particular checkpoints are also described. The transcriptional regulation of T cell development is contrasted with that of B cell development, in terms of their different degrees of overlap with the stem-cell program and the different roles of key transcription factors in gene regulatory networks leading to lineage commitment
Genome of the Root-Associated Plant Growth-Promoting Bacterium Variovorax paradoxus Strain EPS
Variovorax paradoxus is a ubiquitous betaproteobacterium involved in plant growth promotion, the degradation of xenobiotics, and quorum-quenching activity. The genome of V. paradoxus strain EPS consists of a single circular chromosome of 6,550,056 bp, with a 66.48% G+C content
Disentangling the climatic and biotic factors driving changes in the dynamics of Quercus suber populations across the species’ latitudinal range
We thank A.J. Muñoz‐Pajares, L. Rodríguez and G. Rutten for their
help and logistic support during field sampling and M.E. Sánchez,
M. Serrano and M.A. Romero for pathogen analyses and interest‐
ing discussions.Data will be available from the Dryad Digital Repository upon
acceptance.Aim: Impacts of different global change drivers are altering the performance of plant
species worldwide. However, these pressures usually differ across the species’ distri‐
bution range. To properly assess the combined effect of global change at species
level, we need to evaluate its consequences across their complete distribution. We
focused on recent decline in Cork oak (Quercus suber L.) populations given its high
ecological and economic relevance.
Location: We selected 10 different sites (and two populations per site) separated
about one degree in latitude across the core distribution of Q. suber, following a
transcontinental aridity gradient.
Methods: To evaluate the current trends in population dynamics across the species’
distribution and the factors implied on population decline, we evaluated the effect of
latitude, aridity, pathogens (Phytophthora cinnamomi), stand density and tree size on
seed and crop size, demographic structure, dominance of recruitment bank, defolia‐
tion and mortality.
Results: We found an increase in seed weight as latitude decreased, with a homogene‐
ous low crop size across the complete distribution. Demographic structure was deter‐
mined by latitude, precipitation and pathogen abundance. We detected a trend towards
reduced sapling densities towards the southern edge of the distribution, with a demo‐
graphic structure dominated by old trees. The low sapling density at the southern edge
translates into a loss of dominance with respect to other woody species, suggesting an
alteration of community structure in the mid‐term future. Tree density, precipitation
and pathogen abundance determined tree mortality across the species distribution,
with a higher abundance of pathogens in central‐latitude populations.
Main conclusions: Our results allow the early detection of declining trends and the
evaluation of the main risks for species’ conservation, suggesting potential for range
displacement of the species driven by the recruitment failure at the southern edge of
the distribution and a likely range expansion at northern populations.This research was funded by the Large Research
Grant (6007210) awarded from the British Ecological Society to L.M.
L.G.A. acknowledges support from the MICINN project INTERCAPA
(CGL‐2014‐56739‐R) and European FEDER Fund
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