367 research outputs found
The deep history of Earth's biomass
This paper was improved by the comments and suggestions of Graham Shields-Zhou and two anonymous reviewers. We thank E. Buitenhuis for sharing insights into aquatic biomass. S.M. acknowledges support from the European Union’s Horizon 2020 Research and Innovation Programme under Marie Skłodowska-Curie grant agreement 747877.Peer reviewedPostprin
Comparison of Robotics, Functional Electrical Stimulation, and Motor Learning Methods for Treatment of Persistent Upper Extremity Dysfunction After Stroke: A Randomized Controlled Trial
Objective To compare response to upper-limb treatment using robotics plus motor learning (ML) versus functional electrical stimulation (FES) plus ML versus ML alone, according to a measure of complex functional everyday tasks for chronic, severely impaired stroke survivors. Design Single-blind, randomized trial. Setting Medical center. Participants Enrolled subjects (N=39) were \u3e1 year post single stroke (attrition rate=10%; 35 completed the study). Interventions All groups received treatment 5d/wk for 5h/d (60 sessions), with unique treatment as follows: ML alone (n=11) (5h/d partial- and whole-task practice of complex functional tasks), robotics plus ML (n=12) (3.5h/d of ML and 1.5h/d of shoulder/elbow robotics), and FES plus ML (n=12) (3.5h/d of ML and 1.5h/d of FES wrist/hand coordination training). Main Outcome Measures Primary measure: Arm Motor Ability Test (AMAT), with 13 complex functional tasks; secondary measure: upper-limb Fugl-Meyer coordination scale (FM). Results There was no significant difference found in treatment response across groups (AMAT: P≥.584; FM coordination: P≥.590). All 3 treatment groups demonstrated clinically and statistically significant improvement in response to treatment (AMAT and FM coordination: P≤.009). A group treatment paradigm of 1:3 (therapist/patient) ratio proved feasible for provision of the intensive treatment. No adverse effects. Conclusions Severely impaired stroke survivors with persistent (\u3e1y) upper-extremity dysfunction can make clinically and statistically significant gains in coordination and functional task performance in response to robotics plus ML, FES plus ML, and ML alone in an intensive and long-duration intervention; no group differences were found. Additional studies are warranted to determine the effectiveness of these methods in the clinical setting
Tunable Growth Factor Delivery from Injectable Hydrogels for Tissue Engineering
Current sustained delivery strategies of protein therapeutics are limited by the fragility of the protein, resulting in minimal quantities of bioactive protein delivered. In order to achieve prolonged release of bioactive protein, an affinity-based approach was designed which exploits the specific binding of the Src homology 3 (SH3) domain with short proline-rich peptides. Specifically, methyl cellulose was modified with SH3-binding peptides (MC-peptide) with either a weak affinity or strong affinity for SH3. The release profile of SH3-rhFGF2 fusion protein from hyaluronan MC-SH3 peptide (HAMC-peptide) hydrogels was investigated and compared to unmodified controls. SH3-rhFGF2 release from HAMC-peptide was extended to 10 days using peptides with different binding affinities compared to the 48 h release from unmodified HAMC. This system is capable of delivering additional proteins with tunable rates of release, while maintaining bioactivity, and thus is broadly applicable
Controlling cell behavior through the design of polymer surfaces
Polymers have gained a remarkable place in the biomedical
fi eld as materials for the fabrication of various devices and
for tissue engineering applications. The initial acceptance or
rejection of an implantable device is dictated by the crosstalk
of the material surface with the bioentities present in the
physiological environment. Advances in microfabrication
and nanotechnology offer new tools to investigate the
complex signaling cascade induced by the components of
the extracellular matrix and consequently allow cellular
responses to be tailored through the mimicking of some
elements of the signaling paths. Patterning methods and
selective chemical modifi cation schemes at different length
scales can provide biocompatible surfaces that control
cellular interactions on the micrometer and sub-micrometer
scales on which cells are organized. In this review, the
potential of chemically and topographically structured
micro- and nanopolymer surfaces are discussed in hopes
of a better understanding of cell–biomaterial interactions,
including the recent use of biomimetic approaches or
stimuli-responsive macromolecules. Additionally, the focus
will be on how the knowledge obtained using these surfaces
can be incorporated to design biocompatible materials for
various biomedical applications, such as tissue engineering,
implants, cell-based biosensors, diagnostic systems, and basic
cell biology. The review focusses on the research carried out
during the last decade.The research leading to these results has received partial funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement no. NMP4-SL-2009-229292 and by the FCT projects PTDC/FIS/68517/2006, PTDC/QUI/69263/2006, PTDC/FIS/68209/2006, and PTDC/QUI/68804/2006
Design and Synthesis of Binding Growth Factors
Growth factors play important roles in tissue regeneration. However, because of their instability and diffusible nature, improvements in their performance would be desirable for therapeutic applications. Conferring binding affinities would be one way to improve their applicability. Here we review techniques for conjugating growth factors to polypeptides with particular affinities. Conjugation has been designed at the level of gene fusion and of polypeptide ligation. We summarize and discuss the designs and applications of binding growth factors prepared by such conjugation approaches
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