Read by QxMD icon Read


J James Frost, Kenneth J Pienta, Donald S Coffey
Symmetry and symmetry breaking concepts from physics and biology are applied to the problem of cancer. Three categories of symmetry breaking in cancer are examined: combinatorial, geometric, and functional. Within these categories, symmetry breaking is examined for relevant cancer features, including epithelial-mesenchymal transition (EMT); tumor heterogeneity; tensegrity; fractal geometric and information structure; functional interaction networks; and network stabilizability and attack tolerance. The new cancer symmetry concepts are relevant to homeostasis loss in cancer and to its origin, spread, treatment and resistance...
February 20, 2018: Oncotarget
Guang-Kui Xu, Xi-Qiao Feng, Huajian Gao
Mechanical cues from the microenvironments play a regulating role in many physiological and pathological processes, such as stem cell differentiation and cancer cell metastasis. Experiments showed that cells adhered on a compliant substrate may change orientation with an externally applied strain in the substrate. By accounting for actin polymerization, actin retrograde flow, and integrin binding dynamics, here we develop a mechanism-based tensegrity model to study the orientations of polarized cells on a compliant substrate under biaxial stretches...
February 6, 2018: Biophysical Journal
Chenxia Hu, Lanjuan Li
Various diseases and toxic factors easily impair cellular and organic functions in mammals. Organ transplantation is used to rescue organ function, but is limited by scarce resources. Mesenchymal stem cell (MSC)-based therapy carries promising potential in regenerative medicine because of the self-renewal and multilineage potency of MSCs; however, MSCs may lose biological functions after isolation and cultivation for a long time in vitro. Moreover, after they are injected in vivo and migrate into the damaged tissues or organs, they encounter a harsh environment coupled with death signals due to the inadequate tensegrity structure between the cells and matrix...
February 1, 2018: Journal of Cellular and Molecular Medicine
Christopher John Schlicksup, Joseph Che-Yen Wang, Samson Francis, Balasubramanian Venkatakrishnan, William W Turner, Michael VanNieuwenhze, Adam Zlotnick
Defining mechanisms of direct-acting antivirals facilitates drug development and our understanding of virus function. Heteroaryldihydropyrimidines (HAPs) inappropriately activate assembly of hepatitis B virus (HBV) core protein (Cp), suppressing formation of virions. We examined a fluorophore-labeled HAP, HAP-TAMRA. HAP-TAMRA induced Cp assembly and also bound pre-assembled capsids. Kinetic and spectroscopic studies imply that HAP-binding sites are usually not available but are bound cooperatively. Using cryo-EM, we observed that HAP-TAMRA asymmetrically deformed capsids, creating a heterogeneous array of sharp angles, flat regions, and outright breaks...
January 29, 2018: ELife
Błażej Cieślik, Ireneusz Podsiadły, Michał Kuczyński, Bożena Ostrowska
OBJECTIVE: The aim of this study was to investigate the effects of normalized muscle tension via tensegrity-based massage on postural stability in a sample of female young adults. METHODS: Nineteen females aged 21.8 ± 1.9 years were recruited presenting abnormal tension at muscles adhering to any of the following structural sites: superior iliac spine, lateral sacropelvic surface, linea aspera at 1/2 of femur length, and superior nuchal line of the occiput. Balance and postural control were assessed during bipedal stance using a force platform in multiple conditions: hard surface or soft foam surface with the head in either a neutral posture or tilted backward...
November 6, 2017: Journal of Back and Musculoskeletal Rehabilitation
Noshin Afshan, Mashooq Ali, Meng Wang, Mirza Muhammad Faran Ashraf Baig, Shou-Jun Xiao
Using small circular DNA molecules of different lengths as scaffolds, we successfully synthesised DNA nanotubes consisting of Mao's DNA tensegrity triangle tiles with four-arm junctions (Holliday junctions) at all vertices. Due to the intrinsic curvature of the triangle tile and the consecutive tile alignment, the 2D arrays are organised in the form of nanotubes. Two sized triangle tiles with equilateral side lengths of 1.5 and 2.5 full helical turns are connected by the sticky ended cohesion of a duplex with a length of 2...
November 16, 2017: Nanoscale
Carina Hernandez, Jens J Birktoft, Yoel P Ohayon, Arun Richard Chandrasekaran, Hatem Abdallah, Ruojie Sha, Vivian Stojanoff, Chengde Mao, Nadrian C Seeman
There is an increasing appreciation for structural diversity of DNA that is of interest to both DNA nanotechnology and basic biology. Here, we have explored how DNA responds to torsional stress by building on a previously reported two-turn DNA tensegrity triangle and demonstrating that we could introduce an extra nucleotide pair (np) into the original sequence without affecting assembly and crystallization. The extra np imposes a significant torsional stress, which is accommodated by global changes throughout the B-DNA duplex and the DNA lattice...
November 16, 2017: Cell Chemical Biology
Lüwen Zhou, Chen Zhang, Fan Zhang, Shouqin Lü, Shujin Sun, Dongyuan Lü, Mian Long
Translocation of dense nucleus along gravity vector initiates mechanical remodeling of a eukaryotic cell. In our previous experiments, we quantified the impact of gravity vector on cell remodeling by placing an MC3T3-E1 cell onto upward (U)-, downward (D)-, or edge-on (E)- orientated substrate. Our experimental data demonstrate that orientation dependence of nucleus longitudinal translocation is positively correlated with cytoskeletal (CSK) remodeling of their expressions and structures and also is associated with rearrangement of focal adhesion complex (FAC)...
August 17, 2017: Biomechanics and Modeling in Mechanobiology
Michelle Wall, David Butler, Alicia El Haj, Josephine C Bodle, Elizabeth G Loboa, Albert J Banes
Advances in mechanobiology have evolved through insights from multiple disciplines including structural engineering, biomechanics, vascular biology, and orthopaedics. In this paper, we reviewed the impact of key reports related to the study of applied loads on tissues and cells and the resulting signal transduction pathways. We addressed how technology has helped advance the burgeoning field of mechanobiology (over 33,600 publications from 1970 to 2016). We analyzed the impact of critical ideas and then determined how these concepts influenced the mechanobiology field by looking at the citation frequency of these reports as well as tracking how the overall number of citations within the field changed over time...
August 17, 2017: Journal of Orthopaedic Research: Official Publication of the Orthopaedic Research Society
Steven Lessard, Pattawong Pansodtee, Ash Robbins, Leya Breanna Baltaxe-Admony, James M Trombadore, Mircea Teodorescu, Adrian Agogino, Sri Kurniawan
Wearable robots can potentially offer their users enhanced stability and strength. These augmentations are ideally designed to actuate harmoniously with the user's movements and provide extra force as needed. The creation of such robots, however, is particularly challenging due to the underlying complexity of the human body. In this paper, we present a compliant, robotic exosuit for upper extremities called CRUX. This exosuit, inspired by tensegrity models of the human arm, features a lightweight (1.3 kg), flexible multi-joint design for portable augmentation...
July 2017: IEEE ... International Conference on Rehabilitation Robotics: [proceedings]
O Mendoza, P Calmet, I Alves, S Lecomte, M Raoux, C Cullin, J Elezgaray
Control of transport across membranes, whether natural or synthetic, is fundamental in many biotechnology applications, including sensing and drug release. Mutations of naturally existing protein channels, such as hemolysin, have been explored in the past. More recently, DNA channels with conductivities in the nanosiemens range have been designed. Regulating transport across DNA channels in response to external stimuli remains an important challenge. Previous designs relied on steric hindrance to control the inner diameter of the channel, which resulted in unstable electric signatures...
July 13, 2017: Nanoscale
Giuseppina Marsico, Luca Tateo
In this article we propose a development of the Dialogical Self Theory by introducing the notions of borders, cogenetic logic and tensegrity that we have elaborated during the last 5 years, in order to introduce a stronger developmental and dynamic perspective within the theory. We start from the discussion of some recent advancements of the model proposed by Hermans et al. (Integrative Psychological and Behavioural Science, 51(4), 2017), who refer to the metaphor of democratic society of the Self to understand the challenges and possible directions of adaptation that the persons can face in those border-crossing processes characterizing contemporary western societies...
December 2017: Integrative Psychological & Behavioral Science
Ke Liu, Jiangtao Wu, Glaucio H Paulino, H Jerry Qi
Tensegrity structures with detached struts are naturally suitable for deployable applications, both in terrestrial and outer-space structures, as well as morphing devices. Composed of discontinuous struts and continuous cables, such systems are only structurally stable when self-stress is induced; otherwise, they lose the original geometrical configuration (while keeping the topology) and thus can be tightly packed. We exploit this feature by using stimulus responsive polymers to introduce a paradigm for creating actively deployable 3D structures with complex shapes...
June 14, 2017: Scientific Reports
Robert P Bywater
Hydrogen-bonding networks in proteins considered as structural tensile elements are in balance separately from any other stabilising interactions that may be in operation. The hydrogen bond arrangement in the network is reminiscent of tensegrity structures in architecture and sculpture. Tensegrity has been discussed before in cells and tissues and in proteins. In contrast to previous work only hydrogen bonds are studied here. The other interactions within proteins are either much stronger - covalent bonds connecting the atoms in the molecular skeleton or weaker forces like the so-called hydrophobic interactions...
May 2017: Heliyon
Nina I Gabarayeva, Valentina V Grigorjeva
Our findings suggest a new approach to pollen ontogenetic investigations, entailing consideration of physical factors, which enable a better understanding of exine developmental processes. The sporopollenin-containing part of the pollen wall-the exine-is one of the most complex cell walls in plants. By tracing each stage of microspore development in Larix decidua with TEM, we aimed to understand the underlying mechanisms of its exine establishment. Our hypothesis is that self-assembly interferes with exine development...
May 5, 2017: Planta
Xiao Wang, Ruojie Sha, Martin Kristiansen, Carina Hernandez, Yudong Hao, Chengde Mao, James W Canary, Nadrian C Seeman
A 3D array of organic semiconductors was assembled using a DNA scaffold. An octameric aniline molecule ("octaniline") was incorporated into a DNA building block based on a dimeric tensegrity triangle. The construct self-assembled to form a 3D crystal. Reversible redox conversion between the pernigraniline and leucoemeraldine states of the octaniline is retained in the crystal. Protonic doping gave emeraldine salt at pH 5, corresponding to the conductive form of polyaniline. Redox cycling within the crystal was visualized by color changes and Raman microscopy...
June 1, 2017: Angewandte Chemie
M Vassaux, J L Milan
Recent experiments hint that adherent cells are sensitive to their substrate curvature. It is already well known that cells behaviour can be regulated by the mechanical properties of their environment. However, no mechanisms have been established regarding the influence of cell-scale curvature of the substrate. Using a numerical cell model, based on tensegrity structures theory and the non-smooth contact dynamics method, we propose to investigate the mechanical state of adherent cells on concave and convex hemispheres...
August 2017: Biomechanics and Modeling in Mechanobiology
Joseph S Melinger, Ruojie Sha, Chengde Mao, Nadrian C Seeman, Mario G Ancona
DNA crystals make it possible to organize guest molecules into specific periodic 3D patterns at the nanoscale, and thereby to create novel macroscopic objects with potentially useful functionality. Here, we describe the fluorescence and energy transfer properties of DNA crystals that are self-assembled from DNA tensegrity triangles with covalently attached Cy3 and Cy5 dyes. When compared to reference DNA strands in solution, the fluorescence measurements indicate that the dyes in the crystal experience a more homogeneous environment, resulting in a 2-fold increase in Cy3 quantum yield and single-exponential Cy3 fluorescence decays...
December 8, 2016: Journal of Physical Chemistry. B
Nadrian C Seeman, Ruojie Sha, Jens Birktoft, Jianping Zheng, Wenyan Liu, Tong Wang, Chengde Mao
The simplest practical route to producing precisely designed 3D macroscopic objects is to form a crystalline arrangement by self-assembly, because such a periodic array has only conceptually simple requirements: a motif that has a robust 3D structure, dominant affinity interactions between parts of the motif when it self-associates, and predictable structures for these affinity interactions. Fulfilling these three criteria to produce a 3D periodic system is not easy, but should readily be achieved with well-structured branched DNA motifs tailed by sticky ends (Zheng et al...
2017: Methods in Molecular Biology
Guang-Kui Xu, Bo Li, Xi-Qiao Feng, Huajian Gao
Deciphering the mechanisms underlying the high sensitivity of cells to mechanical microenvironments is crucial for understanding many physiological and pathological processes, e.g., stem cell differentiation and cancer cell metastasis. Here, a cytoskeletal tensegrity model is proposed to study the reorientation of polarized cells on a substrate under biaxial cyclic deformation. The model consists of four bars, representing the longitudinal stress fibers and lateral actin network, and eight strings, denoting the microfilaments...
October 4, 2016: Biophysical Journal
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"