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Publications

In vitro culture increases mechanical stability of human tissue engineered cartilage constructs by prevention of microscale scaffold buckling

Cornell Affiliated Author(s)
Author
J.M. Middendorf
S. Shortkroff
C. Dugopolski
S. Kennedy
J. Siemiatkoski
L.R. Bartell
Itai Cohen
L.J. Bonassar
Abstract

Many studies have measured the global compressive properties of tissue engineered (TE) cartilage grown on porous scaffolds. Such scaffolds are known to exhibit strain softening due to local buckling under loading. As matrix is deposited onto these scaffolds, the global compressive properties increase. However the relationship between the amount and distribution of matrix in the scaffold and local buckling is unknown. To address this knowledge gap, we studied how local strain and construct buckling in human TE constructs changes over culture times and GAG content.

Journal
Journal of Biomechanics
Date Published
Funding Source
1536463
DGE-1650441
DMR-1120296
1F31-AR069977
Research Area
Group (Lab)
Itai Cohen Group

Lifetimes and spatio-temporal response of protein crystals in intense X-ray microbeams

Cornell Affiliated Author(s)
Author
M.A. Warkentin
H. Atakisi
J.B. Hopkins
D. Walko
R.E. Thorne
Abstract

Serial synchrotron-based crystallography using intense microfocused X-ray beams, fast-framing detectors and protein microcrystals held at 300 K promises to expand the range of accessible structural targets and to increase overall structure-pipeline throughputs. To explore the nature and consequences of X-ray radiation damage under microbeam illumination, the time-, dose- and temperature-dependent evolution of crystal diffraction have been measured with maximum dose rates of 50 MGy s-1.

Journal
IUCrJ
Date Published
Research Area
Group (Lab)
Robert Thorne Group

Excited states using semistochastic heat-bath configuration interaction

Cornell Affiliated Author(s)
Author
Adam Holmes
C. Umrigar
Sandeep Sharma
Abstract

We extend our recently developed heat-bath configuration interaction (HCI) algorithm, and our semistochastic algorithm for performing multireference perturbation theory, to calculate excited-state wavefunctions and energies. We employ time-reversal symmetry, which reduces the memory requirements by more than a factor of two. An extrapolation technique is introduced to reliably extrapolate HCI energies to the full CI limit.

Journal
Journal of Chemical Physics
Date Published
Funding Source
1534965
Group (Lab)
Cyrus Umrigar Group

Light microscopy at maximal precision

Cornell Affiliated Author(s)
Author
M. Bierbaum
B.D. Leahy
A.A. Alemi
Itai Cohen
J.P. Sethna
Abstract

Microscopy is the workhorse of the physical and life sciences, producing crisp images of everything from atoms to cells well beyond the capabilities of the human eye. However, the analysis of these images is frequently little more accurate than manual marking. Here, we revolutionize the analysis of microscopy images, extracting all the useful information theoretically contained in a complex microscope image.

Journal
Physical Review X
Date Published
Funding Source
1053575
1120296
DMR-1120296
DMR-1507607
ACI-1053575
PRF 56046-ND7
Group (Lab)
Itai Cohen Group
James Sethna Group

Stretchable surfaces with programmable 3D texture morphing for synthetic camouflaging skins

Cornell Affiliated Author(s)
Author
J.H. Pikul
S. Li
H. Bai
R.T. Hanlon
Itai Cohen
R.F. Shepherd
Abstract

Technologies that use stretchable materials are increasingly important, yet we are unable to control how they stretch with much more sophistication than inflating balloons. Nature, however, demonstrates remarkable control of stretchable surfaces; for example, cephalopods can project hierarchical structures from their skin in milliseconds for a wide range of textural camouflage. Inspired by cephalopod muscular morphology, we developed synthetic tissue groupings that allowed programmable transformation of two-dimensional (2D) stretchable surfaces into target 3D shapes.

Journal
Science
Date Published
Funding Source
FA9550-09-0346
W911NF-16-1-0006
Group (Lab)
Itai Cohen Group

Designing solid-liquid interphases for sodium batteries

Cornell Affiliated Author(s)
Author
S. Choudhury
S. Wei
Y. Ozhabes
D. Gunceler
M.J. Zachman
Z. Tu
J.H. Shin
P. Nath
A. Agrawal
L.F. Kourkoutis
Tomas Arias
L.A. Archer
Abstract

Secondary batteries based on earth-abundant sodium metal anodes are desirable for both stationary and portable electrical energy storage. Room-temperature sodium metal batteries are impractical today because morphological instability during recharge drives rough, dendritic electrodeposition. Chemical instability of liquid electrolytes also leads to premature cell failure as a result of parasitic reactions with the anode.

Journal
Nature Communications
Date Published
Funding Source
1654596
DMR-1654596
-AR0000750
KUS-C1-018-02
Group (Lab)
Tomas Arias Group

How confinement-induced structures alter the contribution of hydrodynamic and short-ranged repulsion forces to the viscosity of colloidal suspensions

Cornell Affiliated Author(s)
Author
M. Ramaswamy
N.Y.C. Lin
B.D. Leahy
C. Ness
A.M. Fiore
J.W. Swan
Itai Cohen
Abstract

Confined systems ranging from the atomic to the granular are ubiquitous in nature. Experiments and simulations of such atomic and granular systems have shown a complex relationship between the microstructural arrangements under confinement, the short-ranged particle stresses, and flow fields. Understanding the same correlation between structure and rheology in the colloidal regime is important due to the significance of such suspensions in industrial applications.

Journal
Physical Review X
Date Published
Funding Source
1232666
1509308
Group (Lab)
Itai Cohen Group

Lifshitz transition from valence fluctuations in YbAl3

Cornell Affiliated Author(s)
Author
S. Chatterjee
J.P. Ruf
H.I. Wei
K.D. Finkelstein
D.G. Schlom
K.M. Shen
Abstract

In mixed-valent Kondo lattice systems, such as YbAl3, interactions between localized and delocalized electrons can lead to fluctuations between two different valence configurations with changing temperature or pressure. The impact of this change on the momentum-space electronic structure is essential for understanding their emergent properties, but has remained enigmatic.

Journal
Nature Communications
Date Published
Funding Source
DMR-1120296
0335765
0847385
0903653
1120296
1144153
1332208
DGE-0903653
DGE-1144153
DMR-0847385
DMR-1332208
FA2386-12-1-3013
GBMF3850
2002S
Group (Lab)
Kyle Shen Group

Mechanical properties and structure-function relationships of human chondrocyte-seeded cartilage constructs after in vitro culture

Cornell Affiliated Author(s)
Author
J.M. Middendorf
D.J. Griffin
S. Shortkroff
C. Dugopolski
S. Kennedy
J. Siemiatkoski
Itai Cohen
L.J. Bonassar
Abstract

Autologous Chondrocyte Implantation (ACI) is a widely recognized method for the repair of focal cartilage defects. Despite the accepted use, problems with this technique still exist, including graft hypertrophy, damage to surrounding tissue by sutures, uneven cell distribution, and delamination. Modified ACI techniques overcome these challenges by seeding autologous chondrocytes onto a 3D scaffold and securing the graft into the defect.

Journal
Journal of Orthopaedic Research
Date Published
Funding Source
1536463
DGE-1650441
1120296
1144153
DMR-1120296
Research Area
Group (Lab)
Itai Cohen Group

Review of pseudogaps in strongly interacting Fermi gases

Cornell Affiliated Author(s)
Author
E.J. Mueller
Abstract

A central challenge in modern condensed matter physics is developing the tools for understanding nontrivial yet unordered states of matter. One important idea to emerge in this context is that of a 'pseudogap': the fact that under appropriate circumstances the normal state displays a suppression of the single particle spectral density near the Fermi level, reminiscent of the gaps seen in ordered states of matter. While these concepts arose in a solid state context, they are now being explored in cold gases.

Journal
Reports on Progress in Physics
Date Published
Funding Source
1508300