1,486 research outputs found
Potential of MMP-9 based nanoparticles at optimizing the cow dry period: pulling apart the effects of MMP-9 and nanoparticles
The cow dry period is a non-milking interval where the mammary gland involutes and regenerates
to guarantee an optimal milk production in the subsequent lactation. Important bottlenecks such
as the high risk of intramammary infections complicate the process. Antibiotics have been routinely
used as a preventive treatment but the concerns about potential antibiotic resistance open a new
scenario in which alternative strategies have to be developed. Matrix metalloproteinase-9 (MMP-9) is
an enzyme able to degrade the extracellular matrix, triggering the involution and immune function of
cow mammary gland. We have studied the infusion into the mammary gland of MMP-9 inclusion bodies
as protein-based nanoparticles, demonstrating that 1.2 mg of MMP-9 enhanced the involution and
immune function of the cow mammary gland. However, the comparison of the efects triggered by the
administration of an active and an inactive form of MMP-9 led to conclude that the response observed
in the bovine mammary gland was mainly due to the protein format but not to the biological activity of
the MMP-9 embedded in the inclusion body. This study provides relevant information on the future use
of protein inclusion bodies in cow mammary gland and the role of MMP-9 at dry-of.info:eu-repo/semantics/publishedVersio
WS2/MoS2 Heterostructures through Thermal Treatment of MoS2 Layers Electrostatically Functionalized with W3S4 Molecular Clusters
The preparation of 2D stacked layers that combine flakes of different nature, gives rise to countless number of heterostructures where new band alignments, defined at the interfaces, control the electronic properties of the system. Among the large family of 2D/2D heterostructures, the one formed by the combination of the most common semiconducting transition metal dichalcogenides WS2/MoS2, has awaken great interest due to its photovoltaic and photoelectrochemical properties. Solution as well as dry physical methods have been developed to optimize the synthesis of these heterostructures. Here a suspension of negatively charged MoS2 flakes is mixed with a methanolic solution of a cationic W3S4-core cluster, giving rise to a homogeneous distribution of the clusters over the layers. In a second step, a calcination under N2 of this molecular/2D heterostructure leads to the formation of clean WS2/MoS2 heterostructures where the photoluminescence of both counterparts is quenched, proving an efficient interlayer coupling. Thus, this chemical method combines the advantages of a solution approach (simple, scalable and low-cost) with the good quality interfaces reached by using more complicated traditional physical methods
A new approach to obtain pure and active proteins from Lactococcus lactis protein aggregates
The production of pure and soluble proteins is a complex, protein-dependent and time-consuming
process, in particular for those prone-to-aggregate and/or difcult-to-purify. Although Escherichia coli is
widely used for protein production, recombinant products must be co-purifed through costly processes
to remove lipopolysaccharide (LPS) and minimize adverse efects in the target organism. Interestingly,
Lactococcus lactis, which does not contain LPS, could be a promising alternative for the production
of relevant proteins. However, to date, there is no universal strategy to produce and purify any
recombinant protein, being still a protein-specifc process. In this context and considering that L. lactis
is also able to form functional protein aggregates under overproduction conditions, we explored the use
of these aggregates as an alternative source of soluble proteins. In this study, we developed a widely
applicable and economically afordable protocol to extract functional proteins from these nanoclusters.
For that, two model proteins were used: mammary serum amyloid A3 (M-SAA3) and metalloproteinase
9 (MMP-9), a difcult-to-purify and a prone-to-aggregate protein, respectively. The results show that
it is possible to obtain highly pure, soluble, LPS-free and active recombinant proteins from L. lactis
aggregates through a cost-efective and simple protocol with special relevance for difcult-to-purify or
highly aggregated proteins.info:eu-repo/semantics/publishedVersio
Hadron Energy Reconstruction for the ATLAS Calorimetry in the Framework of the Non-parametrical Method
This paper discusses hadron energy reconstruction for the ATLAS barrel
prototype combined calorimeter (consisting of a lead-liquid argon
electromagnetic part and an iron-scintillator hadronic part) in the framework
of the non-parametrical method. The non-parametrical method utilizes only the
known ratios and the electron calibration constants and does not require
the determination of any parameters by a minimization technique. Thus, this
technique lends itself to an easy use in a first level trigger. The
reconstructed mean values of the hadron energies are within of the
true values and the fractional energy resolution is . The value of the ratio
obtained for the electromagnetic compartment of the combined calorimeter is
and agrees with the prediction that for this
electromagnetic calorimeter. Results of a study of the longitudinal hadronic
shower development are also presented. The data have been taken in the H8 beam
line of the CERN SPS using pions of energies from 10 to 300 GeV.Comment: 33 pages, 13 figures, Will be published in NIM
Quantitative characterization of metabolism and metabolic shifts during growth of the new human cell line AGE1.HN using time resolved metabolic flux analysis
For the improved production of vaccines and therapeutic proteins, a detailed understanding of the metabolic dynamics during batch or fed-batch production is requested. To study the new human cell line AGE1.HN, a flexible metabolic flux analysis method was developed that is considering dynamic changes in growth and metabolism during cultivation. This method comprises analysis of formation of cellular components as well as conversion of major substrates and products, spline fitting of dynamic data and flux estimation using metabolite balancing. During batch cultivation of AGE1.HN three distinct phases were observed, an initial one with consumption of pyruvate and high glycolytic activity, a second characterized by a highly efficient metabolism with very little energy spilling waste production and a third with glutamine limitation and decreasing viability. Main events triggering changes in cellular metabolism were depletion of pyruvate and glutamine. Potential targets for the improvement identified from the analysis are (i) reduction of overflow metabolism in the beginning of cultivation, e.g. accomplished by reduction of pyruvate content in the medium and (ii) prolongation of phase 2 with its highly efficient energy metabolism applying e.g. specific feeding strategies. The method presented allows fast and reliable metabolic flux analysis during the development of producer cells and production processes from microtiter plate to large scale reactors with moderate analytical and computational effort. It seems well suited to guide media optimization and genetic engineering of producing cell lines
Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC
The uncertainty on the calorimeter energy response to jets of particles is
derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the
calorimeter response to single isolated charged hadrons is measured and
compared to the Monte Carlo simulation using proton-proton collisions at
centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009
and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter
response to specific types of particles (positively and negatively charged
pions, protons, and anti-protons) is measured and compared to the Monte Carlo
predictions. Finally, the jet energy scale uncertainty is determined by
propagating the response uncertainty for single charged and neutral particles
to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3%
for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table,
submitted to European Physical Journal
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