Skip to main content

Publications

Effects of protein-crystal hydration and temperature on side-chain conformational heterogeneity in monoclinic lysozyme crystals

Cornell Affiliated Author(s)
Author
H. Atakisi
D.W. Moreau
R.E. Thorne
Abstract

The modulation of main-chain and side-chain conformational heterogeneity and solvent structure in monoclinic lysozyme crystals by dehydration (related to water activity) and temperature is examined. Decreasing the relative humidity (from 99 to 11%) and decreasing the temperature both lead to contraction of the unit cell, to an increased area of crystal contacts and to remodeling of primarily contact and solvent-exposed residues. Both lead to the depopulation of some minor side-chain conformers and to the generation of new conformations.

Journal
Acta Crystallographica Section D: Structural Biology
Date Published
Research Area
Group (Lab)
Robert Thorne Group

Local and global measurements show that damage initiation in articular cartilage is inhibited by the surface layer and has significant rate dependence

Cornell Affiliated Author(s)
Author
L.R. Bartell
M.C. Xu
L.J. Bonassar
Itai Cohen
Abstract

Cracks in articular cartilage are a common sign of joint damage, but failure properties of cartilage are poorly understood, especially for damage initiation. Cartilage failure may be further complicated by rate-dependent and depth-dependent properties, including the compliant surface layer. Existing blunt impact methods do not resolve local cartilage inhomogeneities and traditional fracture mechanics tests induce crack blunting and may violate underlying assumptions of linear elasticity.

Journal
Journal of Biomechanics
Date Published
Funding Source
DMR-1719875
CMMI 1536463
F31AR069977
Group (Lab)
Itai Cohen Group

Synthesis science of SrRuO3 and CaRuO3 epitaxial films with high residual resistivity ratios

Cornell Affiliated Author(s)
Author
H.P. Nair
Y. Liu
J.P. Ruf
N.J. Schreiber
S.-L. Shang
D.J. Baek
B.H. Goodge
L.F. Kourkoutis
Z.-K. Liu
K.M. Shen
D.G. Schlom
Abstract

Epitaxial SrRuO3 and CaRuO3 films were grown under an excess flux of elemental ruthenium in an adsorption-controlled regime by molecular-beam epitaxy (MBE), where the excess volatile RuOx (x = 2 or 3) desorbs from the growth front leaving behind a single-phase film. By growing in this regime, we were able to achieve SrRuO3 and CaRuO3 films with residual resistivity ratios (Ï300 K/Ï4 K) of 76 and 75, respectively.

Journal
APL Materials
Date Published
Funding Source
1709255
Group (Lab)
Kyle Shen Group

X-ray absorption spectroscopy study of annealing process on Sr1-xLaxCuO2 electron-doped cuprate thin films

Cornell Affiliated Author(s)
Author
A. Galdi
P. Orgiani
C. Sacco
B. Gobaut
P. Torelli
C. Aruta
N.B. Brookes
M. Minola
J.W. Harter
K.M. Shen
D.G. Schlom
L. Maritato
Abstract

The superconducting properties of Sr1-xLaxCuO2 thin films are strongly affected by sample preparation procedures, including the annealing step, which are not always well controlled. We have studied the evolution of Cu L2,3 and O K edge x-ray absorption spectra (XAS) of Sr1-xLaxCuO2 thin films as a function of reducing annealing, both qualitatively and quantitatively.

Journal
Journal of Applied Physics
Date Published
Funding Source
DMR-1719875
ECCS-15420819
1719875
DMR-1610781
Group (Lab)
Kyle Shen Group

Facilitated recruitment of mesenchymal stromal cells by bone marrow concentrate and platelet rich plasma

Cornell Affiliated Author(s)
Author
H.L. Holmes
B. Wilson
J.P. Goerger
J.L. Silverberg
Itai Cohen
W.R. Zipfel
L.A. Fortier
Abstract

Background Biologics containing growth factors are frequently used to enhance healing after musculoskeletal injuries. One mechanism of action is thought to be though the ability of biologics to induce homing and migration of endogenous mesenchymal stromal cells (MSCs) to a target tissue. However, the ability of biologics to stimulate chemotaxis (directed migration of cells) and chemokinesis (increase rate of cell migration) of MSCs is unknown.

Journal
PLoS ONE
Date Published
Funding Source
T32RR018269
C028097
Research Area
Group (Lab)
Itai Cohen Group

Coherent generation of photonic fractional quantum Hall states in a cavity and the search for anyonic quasiparticles

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

We present and analyze a protocol in which polaritons in a noncoplanar optical cavity form fractional quantum Hall states. We model the formation of these states and present techniques for subsequently creating anyons and measuring their fractional exchange statistics. In this protocol, we use a rapid adiabatic passage scheme to sequentially add polaritons to the system, such that the system is coherently driven from n- to (n+1)-particle Laughlin states. Quasiholes are created by slowly moving local pinning potentials in from outside the cloud.

Journal
Physical Review A
Date Published
Funding Source
1508300
PHY-1508300
W9111NF-14-1-0003

Excited States of Methylene, Polyenes, and Ozone from Heat-Bath Configuration Interaction

Cornell Affiliated Author(s)
Author
Alan Chien
Adam Holmes
Matthew Otten
C. Umrigar
Sandeep Sharma
Paul Zimmerman
Abstract

The electronically excited states of methylene (CH2), ethylene (C2H4), butadiene (C4H6), hexatriene (C6H8), and ozone (O3) have long proven challenging due to their complex mixtures of static and dynamic correlations. The semistochastic heat-bath configuration interaction (SHCI) algorithm, which efficiently and systematically approaches the full configuration interaction (FCI) limit, is used to provide close approximations to the FCI energies in these systems.

Journal
Journal of Physical Chemistry A
Date Published
Funding Source
ACI-1445606
ACI-1534965
Group (Lab)
Cyrus Umrigar Group

Temperature-dependence of stress and elasticity in wet-transferred graphene membranes

Cornell Affiliated Author(s)
Author
R. De Alba
T.S. Abhilash
A. Hui
I.R. Storch
H.G. Craighead
J.M. Parpia
Abstract

We report measurements of the mechanical properties of two suspended graphene membranes in the temperature range of 80 K to 550 K. For this entire range, the resonant frequency and quality factor of each device were monitored continuously during cooling and heating. Below 300 K, we have additionally measured the resonant frequency's tunability via electrostatic force, and modeled this data to determine graphene's tension and elastic modulus; both of these parameters are found to be strongly temperature-dependent in this range.

Journal
Journal of Applied Physics
Date Published
Funding Source
ECCS-1542081
1708341
DMR-1202991
DMR-1708341
DMR-1120296
Group (Lab)
Jeevak Parpia Group

Electrically tunable single- and few-layer MoS2 nanoelectromechanical systems with broad dynamic range

Cornell Affiliated Author(s)
Author
J. Lee
Z. Wang
K. He
R. Yang
J. Shan
P.X.-L. Feng
Abstract

Atomically thin semiconducting crystals [such as molybdenum disulfide (MoS2)] have outstanding electrical, optical, and mechanical properties, thus making them excellent constitutive materials for innovating new two-dimensional (2D) nanoelectromechanical systems (NEMS). Although prototype structures have recently been demonstrated toward functional devices such as ultralow-power, high-frequency tunable oscillators and ultrasensitive resonant transducers, both electrical tunability and large dynamic range (DR) are critical and desirable.

Journal
Science Advances
Date Published
Funding Source
0907477
DMR-0907477
61774029
Group (Lab)
Jie Shan Group