4,822 research outputs found
Endoglin Is Essential for the Maintenance of Self-Renewal and Chemoresistance in Renal Cancer Stem Cells.
Renal cell carcinoma (RCC) is a deadly malignancy due to its tendency to metastasize and resistance to chemotherapy. Stem-like tumor cells often confer these aggressive behaviors. We discovered an endoglin (CD105)-expressing subpopulation in human RCC xenografts and patient samples with a greater capability to form spheres in vitro and tumors in mice at low dilutions than parental cells. Knockdown of CD105 by short hairpin RNA and CRISPR/cas9 reduced stemness markers and sphere-formation ability while accelerating senescence in vitro. Importantly, downregulation of CD105 significantly decreased the tumorigenicity and gemcitabine resistance. This loss of stem-like properties can be rescued by CDA, MYC, or NANOG, and CDA might act as a demethylase maintaining MYC and NANOG. In this study, we showed that Endoglin (CD105) expression not only demarcates a cancer stem cell subpopulation but also confers self-renewal ability and contributes to chemoresistance in RCC
A modified model of non-locally corrected gravity: Cosmology and the Newtonian limit
A modified form of non-locally corrected theory of gravity is investigated in
the context of cosmology and the Newtonian limit. This form of non-local
correction to classic Einstein-Hilbert action can be locally represented by a
triple-scalar-tensor theory in which one of the scalar degree of freedom is
phantom-like and the other two are quintessence-like. We show that there exists
a stable de Sitter solution for the cosmological dynamics if a suitable form of
potential function (or equivalently, ) is selected. However, no
matter what a potential function is selected, there is always an early time
repeller solution corresponding to a radiation dominated universe. Besides, the
equations for linear scalar perturbations are presented and it is shown that
the form of potential function is stringently constrained by the
Solar system test, although the post-Newtonian parameter is not
directly affected by this function.Comment: 11 pages, 2 figures; V2:reference added; matched with the published
versio
Ultrafast All Optical Switching via Tunable Fano Interference
Tunneling induced quantum interference experienced by an incident probe in asymmetric double
quantum wells can easily be modulated by means of an external control light beam. This phenomenon,
which is here examined within the dressed-state picture, can be exploited to devise a novel all-optical
ultrafast switch. For a suitably designed semiconductor heterostructure, the switch is found to exhibit
frequency bandwidths of the order of 0.1 THz and response and recovery times of about 1 ps
Competition between linear and cyclic structures in monochromium carbide clusters CrCn- and CrCn (n=2-8): A photoelectron spectroscopy and density functional study
Photoelectron spectroscopy (PES) is combined with density functional theory (DFT) to study the monochromium carbide clusters CrCân and CrCnâ(n=2â8). Well-resolved PES spectra were obtained, yielding structural, electronic, and vibrational information about both the anionic and neutral clusters. Experimental evidence was observed for the coexistence of two isomers for CrCâ2, CrCâ3, CrCâ4, and CrCâ6. Sharp and well-resolved PES spectra were observed for CrCânâ(n=4,6,8), whereas broad spectra were observed for CrCâ5 and CrCâ7. Extensive DFT calculations using the generalized gradient approximation were carried out for the ground and low-lying excited states of all the CrCân and CrCn species, as well as coupled-cluster calculations for CrCâ2 and CrC2. Theoretical electron affinities and vertical detachment energies were calculated and compared with the experimental data to help the assignment of the ground states and obtain structural information. We found that CrCâ2 and CrCâ3 each possess a close-lying cyclic and linear structure, which were both populated experimentally. For the larger CrCân clusters with n=4, 6, 8, linear structures are the overwhelming favorite, giving rise to the sharp PES spectral features. CrCâ7 was found to have a cyclic structure. The broad PES spectra of CrCâ5 suggested a cyclic structure, whereas the DFT results predicted a linear one
Critical current degradation caused by winding process of Bi-2223/Ag HTS wire in the form of a coil
High T, superconducting (HTS) (Bi,Pb)2Sr2Ca2 Cu3010+xA g-clad wire has potential for practical applications in the form of a coil or a winding. This HTS wire has strong magnetic field-dependent and mechanical strain-dependent critical currents, consequently it faces a severe problem of critical current degradation when it is used in the form of a coil. To design a winding with this conductor, the critical current degradation has to be identified with relation to the magnetic fields and the winding process. This is important to optimize an appropriate coil winding procedure using this HTS wire. A specially designed non-inductive sample has been made with a (Bi,Pb)2Sr2Ca2 C U J O ~A~g+-c~la d 27-filament wire, and the critical current degradation, which is caused by the magnetic field generated and the mechanical winding procedure used to form a coil, has been separated into two factors accordingly, and discussed in this paper
Gravitating Global k-monopole
A gravitating global k-monopole produces a tiny gravitational field outside
the core in addition to a solid angular deficit in the k-field theory. As a new
feature, the gravitational field can be attractive or repulsive depending on
the non-canonical kinetic term.Comment: 9 pages, 2 figures, references added, typos corrected, accepted by
Class. Quantum Gra
Infant attraction: why social bridging matters for female leadership in Tibetan macaques
Leadership is a key issue in the study of collective behavior in social animals. Affiliationâleadership models predict that dyadic partner preferences based on grooming relationships or alliance formation positively affect an individualâs decision to follow or support a conspecific. In the case of many primate species, females without young infants are attracted to motherâinfant dyads. However, the effects of motherâinfantâfemale associations on affiliationâleadership models remain less clear. In free-ranging Tibetan macaques Macaca thibetana, we used social network analysis to examine the importance of âmother-infant-adult femaleâ social bridging events as a predictor of who leads and who follows during group movement. Social bridging is a common behavior in Tibetan macaques and occurs when 2 adults, generally females, engage in coordinated infant handling. Using eigenvector centrality coefficients of social bridging as a measure of social affiliation, we found that among lactating females, initiating bridging behavior with another female played a significant role in leadership success, with the assisting female following the mother during group movement. Among nonlactating females, this was not the case. Our results indicate that infant attraction can be a strong trigger in collective action and directing group movement in Tibetan macaques and provides benefits to mothers who require helpers and social support in order to ensure the safety of their infants. Our study provides new insights into the importance of the third-party effect in rethinking affiliationâleadership models in group-living animals
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