Read by QxMD icon Read


Fu-Lai Wen, Yu-Chiun Wang, Tatsuo Shibata
During embryonic development, epithelial sheets fold into complex structures required for tissue and organ functions. Although substantial efforts have been devoted to identifying molecular mechanisms underlying epithelial folding, far less is understood about how forces deform individual cells to sculpt the overall sheet morphology. Here we describe a simple and general theoretical model for the autonomous folding of monolayered epithelial sheets. We show that active modulation of intracellular mechanics along the basal-lateral as well as the apical surfaces is capable of inducing fold formation in the absence of buckling instability...
June 20, 2017: Biophysical Journal
Anthony C Schramm, Glen M Hocky, Gregory A Voth, Laurent Blanchoin, Jean-Louis Martiel, Enrique M De La Cruz
Computational and structural studies have been indispensable in investigating the molecular origins of actin filament mechanical properties and modulation by the regulatory severing protein cofilin. All-atom molecular dynamics simulations of cofilactin filament structures determined by electron cryomicroscopy reveal how cofilin enhances the bending and twisting compliance of actin filaments. Continuum mechanics models suggest that buckled cofilactin filaments localize elastic energy at boundaries between bare and cofilin-decorated segments because of their nonuniform elasticity, thereby accelerating filament severing...
June 20, 2017: Biophysical Journal
Kyung-In Jang, Kan Li, Ha Uk Chung, Sheng Xu, Han Na Jung, Yiyuan Yang, Jean Won Kwak, Han Hee Jung, Juwon Song, Ce Yang, Ao Wang, Zhuangjian Liu, Jong Yoon Lee, Bong Hoon Kim, Jae-Hwan Kim, Jungyup Lee, Yongjoon Yu, Bum Jun Kim, Hokyung Jang, Ki Jun Yu, Jeonghyun Kim, Jung Woo Lee, Jae-Woong Jeong, Young Min Song, Yonggang Huang, Yihui Zhang, John A Rogers
Low modulus, compliant systems of sensors, circuits and radios designed to intimately interface with the soft tissues of the human body are of growing interest, due to their emerging applications in continuous, clinical-quality health monitors and advanced, bioelectronic therapeutics. Although recent research establishes various materials and mechanics concepts for such technologies, all existing approaches involve simple, two-dimensional (2D) layouts in the constituent micro-components and interconnects. Here we introduce concepts in three-dimensional (3D) architectures that bypass important engineering constraints and performance limitations set by traditional, 2D designs...
June 21, 2017: Nature Communications
Leyla Niyaz, Ozlem Eski Yucel, Adem Gul
PURPOSE: The hypothesis that the extraocular muscle insertion distance and muscle width may be associated with the type and size of deviation was tested. METHODS: This was a prospective study of 129 patients who had surgery for horizontal strabismus or retinal detachment. The insertion distances and widths of the medial rectus (MR) and lateral rectus (LR) muscles were measured intraoperatively in esotropia, exotropia, and buckling surgery (control group) patients...
June 20, 2017: Current Eye Research
Meng Hu, Julong He, Zhisheng Zhao, Timothy A Strobel, Wentao Hu, Dongli Yu, Hao Sun, Lingyu Liu, Zihe Li, Mengdong Ma, Yoshio Kono, Jinfu Shu, Ho-Kwang Mao, Yingwei Fei, Guoyin Shen, Yanbin Wang, Stephen J Juhl, Jian Yu Huang, Zhongyuan Liu, Bo Xu, Yongjun Tian
Carbon's unique ability to have both sp(2) and sp(3) bonding states gives rise to a range of physical attributes, including excellent mechanical and electrical properties. We show that a series of lightweight, ultrastrong, hard, elastic, and conductive carbons are recovered after compressing sp(2)-hybridized glassy carbon at various temperatures. Compression induces the local buckling of graphene sheets through sp(3) nodes to form interpenetrating graphene networks with long-range disorder and short-range order on the nanometer scale...
June 2017: Science Advances
Kevin J Boyd, Nathan N Alder, Eric R May
Mitochondrial metabolic function is affected by the morphology and protein organization of the mitochondrial inner membrane (MIM). Cardiolipin (CL) is a unique tetra-acyl lipid that is involved in the maintenance of the highly-curved shape of the MIM as well as spatial organization of the proteins necessary for respiration and oxidative phosphorylation. Cardiolipin has been suggested to self-organize into lipid domains due to its inverted conical molecular geometry, though the driving forces for this organization are not fully understood...
June 19, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
Ryu-Suke Nozawa, Lora Boteva, Dinesh C Soares, Catherine Naughton, Alison R Dun, Adam Buckle, Bernard Ramsahoye, Peter C Bruton, Rebecca S Saleeb, Maria Arnedo, Bill Hill, Rory R Duncan, Sutherland K Maciver, Nick Gilbert
Higher eukaryotic chromosomes are organized into topologically constrained functional domains; however, the molecular mechanisms required to sustain these complex interphase chromatin structures are unknown. A stable matrix underpinning nuclear organization was hypothesized, but the idea was abandoned as more dynamic models of chromatin behavior became prevalent. Here, we report that scaffold attachment factor A (SAF-A), originally identified as a structural nuclear protein, interacts with chromatin-associated RNAs (caRNAs) via its RGG domain to regulate human interphase chromatin structures in a transcription-dependent manner...
June 15, 2017: Cell
K N Buckle, P C Bingham
No abstract text is available yet for this article.
July 2017: Veterinary Pathology
Xinpeng Xu, Samuel A Safran
We theoretically predict the nonlinear elastic responses of polydisperse biopolymer gels to uniaxial compression. We analyze the competition between compressive stiffening due to polymer densification by out-going solvent flow and compressive softening due to continuous polymer buckling. We point out that the polydispersity in polymer lengths can result in an intrinsic, equilibrium mode of nonaffine compression: nonuniform strain but with uniform force distribution, which is found to be more energetically preferable than affine deformation...
May 2017: Physical Review. E
Sumitabha Brahmachari, John F Marko
We present a statistical-mechanical model for the behavior of intertwined DNAs, with a focus on their torque and extension as a function of their catenation (linking) number and applied force, as studied in magnetic tweezers experiments. Our model produces results in good agreement with available experimental data and predicts a catenation-dependent effective twist modulus distinct from what is observed for twisted individual double-helix DNAs. We find that buckling occurs near the point where experiments have observed a kink in the extension versus linking number, and that the subsequent "supercoiled braid" state corresponds to a proliferation of multiple small plectoneme structures...
May 2017: Physical Review. E
Christina Kurzthaler, Thomas Franosch
Exact solutions for the elastic and thermodynamic properties for the wormlike chain model are elaborated in terms of Mathieu functions. The smearing of the classical Euler buckling instability for clamped polymers is analyzed for the force-extension relation. Interestingly, at strong compression forces the thermal fluctuations lead to larger elongations than for the elastic rod. The susceptibility defined as the derivative of the force-extension relation displays a prominent maximum at a force that approaches the critical Euler buckling force as the persistence length is increased...
May 2017: Physical Review. E
Yumino Hayase, Takahiro Sakaue, Hiizu Nakanishi
Configurations of a single semiflexible polymer is studied when it is pushed into a nanochannel in the case where the polymer persistence length l_{p} is much longer than the channel diameter D:l_{p}/D≫1. Using numerical simulations, we show that the polymer undergoes a sequence of recurring structural transitions upon longitudinal compression: random deflection along the channel, a helix going around the channel wall, double-fold random deflection, double-fold helix, etc. We find that the helix transition can be understood as buckling of deflection segments, and the initial helix formation takes place at very small compression with no appreciable weak compression regime of the random deflection polymer...
May 2017: Physical Review. E
François Sicard, Alberto Striolo
The buckling mechanism in droplets stabilized by solid particles (armored droplets) is tackled at a mesoscopic level using dissipative particle dynamics simulations. We consider one spherical water droplet in a decane solvent coated with nanoparticle monolayers of two different types: Janus (particles whose surface shows two regions with different wetting properties) and homogeneous. The chosen particles yield comparable initial three-phase contact angles, selected to maximize the adsorption energy at the interface...
June 14, 2017: Nanoscale
Bin Ouyang, Shiyun Xiong, Zhi Yang, Yuhang Jing, Yongjie Wang
The structural phase transition in MoS2 promises applications in novel nanoelectronic devices. Elastic strain engineering can not only serve as a potential route for phase transition engineering, but also reveal potential ferroelastic behavior of MoS2 nanostructures. However, the elastic strain required for phase transition in monolayer MoS2 is far beyond its elastic limit, thus inhibiting the experimental realization. In this study, employing density functional theory calculations, we uncover that by forming heterostructure with buckled 2D materials, such as silicene, germanene and stanene, the critical phase transition strain required in monolayer MoS2 can be drastically reduced...
June 12, 2017: Nanoscale
Gabriele C DeLuca, Guy Buckle, Irene Cortese, Jennifer S Graves, June Halper, Scott D Newsome, Nancy Sicotte, Corey C Ford
Multiple sclerosis (MS) is a complex neurologic disorder that affects people with ever-changing needs. The MS health-care field has entered an era of exponential knowledge growth in which better understanding of the immunologic dysregulation of the disease has translated into an expanding array of treatment options. It is estimated that, if it has not already, within the next decade the demands of a growing MS patient population will outstrip the number of professionals dedicated to the management of this chronic, lifelong disease...
May 2017: International Journal of MS Care
Tsung-Han Lee, Yi-Hao Chen, Hsi-Kung Kuo, Yung-Jen Chen, Chih-Hsin Chen, Jong-Jer Lee, Pei-Chang Wu
PURPOSE: Basketball is a popular sport involving significant body contact, which may frequently result in ocular trauma. The aim of this study was to evaluate the characteristics and visual outcomes of retinal detachment associated with basketball-related injury. DESIGN: Retrospective, interventional case series. METHODS: We reviewed the course of patients who sustained traumatic retinal detachment from basketball-related ocular trauma between 2003 and 2015...
June 6, 2017: American Journal of Ophthalmology
Petra Meier
The number of retinal detachments in children is rarely compared to the number of retinal detachments in adults; only 3 - 7% occur in children. The main predisposing factors are trauma, myopia, hereditary vitreoretinopathies, retinopathy of prematurity, malformations and Coats' disease. The most frequent paediatric retinal detachments are trauma-associated and vitreoretinopathies are the most common cause of inherited retinal detachment. Disease-specific surgical treatments are discussed. Episcleral buckling surgery should be the preferred method in any case of clear lens, especially for treatment of oradialysis and well-defined localization of peripherally retinal tears...
June 9, 2017: Klinische Monatsblätter Für Augenheilkunde
Fabio Leoni, Yair Shokef
We show how including attraction in interparticle interactions reverses the effect of fluctuations in ordering of a prototypical artificial frustrated system. Buckled colloidal monolayers exhibit the same ground state as the Ising antiferromagnet on a deformable triangular lattice, but it is unclear if ordering in the two systems is driven by the same geometric mechanism. By a real-space expansion we find that, for buckled colloids, bent stripes constitute the stable phase, whereas in the Ising antiferromagnet straight stripes are favored...
May 26, 2017: Physical Review Letters
Tyler W Herod, Samuel P Veres
Tendinopathic tissue has long been characterized by changes to collagen microstructure. However, initial tendon damage from excessive mechanical loading-a hallmark of tendinopathy development-could occur at the nanoscale level of collagen fibrils. Indeed, it is on this scale that tenocytes interact directly with tendon matrix, and excessive collagen fibril damage not visible at the microscale could trigger a degenerative cascade. In this study we explored whether initiation of tendon damage during cyclic loading occurs via a longitudinal compression-induced buckling mechanism of collagen fibrils leading to nanoscale kinkband development...
June 9, 2017: Journal of Orthopaedic Research: Official Publication of the Orthopaedic Research Society
Jake W Sharp, Rachael M Edwards
This is the 38th installment of a series that will highlight one case per publication issue from the bank of cases available online as part of the American Society of Emergency Radiology (ASER) educational resources. Our goal is to generate more interest in and use of our online materials. To view more cases online, please visit the ASER Core Curriculum and Recommendations for Study online at:
June 7, 2017: Emergency Radiology
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"