752 research outputs found
Measurement Of Quasiparticle Transport In Aluminum Films Using Tungsten Transition-Edge Sensors
We report new experimental studies to understand the physics of phonon
sensors which utilize quasiparticle diffusion in thin aluminum films into
tungsten transition-edge-sensors (TESs) operated at 35 mK. We show that basic
TES physics and a simple physical model of the overlap region between the W and
Al films in our devices enables us to accurately reproduce the experimentally
observed pulse shapes from x-rays absorbed in the Al films. We further estimate
quasiparticle loss in Al films using a simple diffusion equation approach.Comment: 5 pages, 6 figures, PRA
Small Force, Big Impact: Next Generation Organ-on-a-Chip Systems Incorporating Biomechanical Cues
Mechanobiology-on-a-chip is a growing field focusing on how mechanical inputs modulate physico-chemical output in microphysiological systems. It is well known that biomechanical cues trigger a variety of molecular events and adjustment of mechanical forces is therefore essential for mimicking in vivo physiologies in organon-a-chip technology. Biomechanical inputs in organ-on-a-chip systems can range from variations in extracellular matrix type and stiffness and applied shear stresses to active stretch/strain or compression forces using integrated flexible membranes. The main advantages of these organ-on-a-chip systems are therefore (a) the control over spatiotemporal organization of in vivo-like tissue architectures, (b) the ability to precisely control the amount, duration and intensity of the biomechanical stimuli, and (c) the capability of monitoring in real time the effects of applied mechanical forces on cell, tissue and organ functions. Consequently, over the last decade a variety of microfluidic devices have been introduced to recreate physiological microenvironments that also account for the influence of physical forces on biological functions. In this review we present recent advances in mechanobiological lab-on-a-chip systems and report on lessons learned from these current mechanobiological models. Additionally, future developments needed to engineer next-generation physiological and pathological organ-on-a-chip models are discussed
Expression, purification and in vitro biological activity from human recombinant BMP-2 produced by a novel approach
Bone morphogenetic proteins have promoted great
biomedical interest due to their ability in inducing
new bone formation when used as powerful
osteoinductive components of several late-stage
bone grafting products. Recombinant human bone
morphogenetic protein-2 (rhBMP-2) is obtained from
mammalian cell expressing systems in low amounts
or from bacteria inclusion bodies after timeconsuming
refolding methods. Thus, there is a need
to establish novel approaches for producing rhBMP-2
in high yields by simple and cheap procedures.Portuguese Foundation for Science and Technolog
y, FCT (PhD Grant to PC
Bessa
, SFRH/BD/17049/2004). This work was also partially supported
by the European STREP HIPPOCRATES (NMP3
-
CT
-
2003
-
505758) and carried out under the scope of European
NoE
EXPERTISSUES (NMP3
-
CT
-
2004
-
500283).info:eu-repo/semantics/publishedVersio
A novel approach for the production of human recombinant BMP-2 for bone tissue engineering applications
Bone tissue engineering has been an increasing field of research during the last years. The ideal approach for a regenerative application would consist in
the use of cells from the patient, scaffolding materials and differentiation growth factors. Bone morphogenetic protein-2 (BMP-2) is one such growth factors
with a strong ability to induce new bone and cartilage formation and has been used as a powerful osteoinductive component of several late-stage tissue
engineering products for bone grafting. In this work, we aimed at obtaining high yields of human recombinant BMP-2 in a stable, pure and biologically active
form by use of a new bacteria expression system that circumvents the disadvantages of conventional recombinant protein preparation methods and to
perform a study of the stability conditions and the functionality of these peptides in vitro in human mesenchymal stem cells and C2C12 murine cell line.info:eu-repo/semantics/publishedVersio
Expression, purification and in vitro biological activity from human recombinant BMP-2 produced by a novel approach
Bone tissue engineering has been an increasing field of research during the last years. The ideal approach for a regenerative application would consist in the use of cells from the patient, scaffolding materials and
differentiation growth factors. Bone morphogenetic protein-2 (BMP-2) is one such growth factors with a strong ability to induce new bone and cartilage formation and has been used as a powerful osteoinductive
component of several late-stage tissue engineering products for bone grafting. In this work, we aimed at obtaining high yields of human recombinant BMP-2 in a stable, pure and biologically active form by use of a
new bacteria expression system that circumvents the disadvantages of conventional recombinant protein preparation methods and to perform a study of the stability conditions and functionality of these peptides in vitro in human mesenchymal stem cells and C2C12 murine cell line.Portuguese Foundation for Science and Technology, FCT (PhD Grant
to PC Bessa, to PC Bessa, SFRH/BD/17049/2004 SFRH/BD/17049/2004
). This work was ). This work was also partially supported by the European STREP HIPPOCRATES (NMP3 also partially supported by the European STREP HIPPOCRATES (NMP3--CTCT--2003 2003--505758) and carried out under the scope of
505758) and carried out under the scope of
European NoE EXPERTISSUES (NMP3 European NoE EXPERTISSUES (NMP3--CTCT-
-2004 2004 --500283). 500283info:eu-repo/semantics/publishedVersio
A novel system for producing human recombinant BMP-2 and study of the growth factor stabilizing conditions
Bone tissue engineering has been an increasing field of research during the last years. The ideal approach for a regenerative application would consist in the use
of cells from the patient, scaffolding materials and differentiation growth factors. Bone morphogenetic protein-2 (BMP-2) is one such growth factors with a strong
ability to induce new bone and cartilage formation and has been used as a powerful osteoinductive component of several late-stage tissue engineering products for
bone grafting. In this work, we aimed at obtaining high yields of human recombinant BMP-2 in a stable, pure and biologically active form by use of a new bacteria
expression system that circumvents the disadvantages of conventional recombinant protein preparation methods and to perform a study of the stability conditions
and the functionality of these peptides in vitro in human mesenchymal stem cells and C2C12 murine cell line.Portuguese Foundation for Science and Technology (PhD Grant to PC Bessa,
SFRH/BD/17049/2004). This work was also partially supported by the
European STREP HIPPOCRATES (NMP3-CT-2003-505758) and carried out
under the scope of European NoE EXPERTISSUES (NMP3-CT-2004-
500283).info:eu-repo/semantics/publishedVersio
Nonlinear Optimal Filter Technique For Analyzing Energy Depositions In TES Sensors Driven Into Saturation
We present a detailed thermal and electrical model of superconducting transition edge sensors (TESs) connected to quasiparticle (qp) traps, such as the W TESs connected to Al qp traps used for CDMS (Cryogenic Dark Matter Search) Ge and Si detectors. We show that this improved model, together with a straightforward time-domain optimal filter, can be used to analyze pulses well into the nonlinear saturation region and reconstruct absorbed energies with optimal energy resolution
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