Cancer cells grow in an environment comprised of multiple components that support tumor growth and contribute to therapy resistance. Major cell types in the tumor microenvironment are fibroblasts, ...endothelial cells and infiltrating immune cells all of which communicate with cancer cells. One way that these cell types promote cancer progression is by altering the expression of microRNAs (miRNAs), small noncoding RNAs that negatively regulate protein expression, either in the cancer cells or in the associated normal cells. Changes in miRNA expression can be brought about by direct interaction between the stromal cells and cancer cells, by paracrine factors secreted by any of the cell types or even through direct communication between cells through secreted miRNAs. Understanding the role of miRNAs in the complex interactions between the tumor and cells in its microenvironment is necessary if we are to understand tumor progression and devise new treatments.
Free decay of homogeneous vortex tangle in superfluid has been studied for ultra-quantum and quasi-classical regimes at zero temperature limit. It is found that the decay process is associated with ...heating by means of phonon generation into the system, even at such a zero temperature limit. An explicit expression for the time evolution of temperature due to the heating has been derived. Such heating affects the motion of vortex strings by (a) decreasing their cyclotron frequencies and (b) shortening their length. This length shortening is a secondary decay process initiated by the primary free decay of vortex tangles. The effect of quasiparticles (phonons) on the wave collapse and energy dissipation of the turbulent states has also been studied through the modulation theory.
Multiple periodic domain formation due to a modulation instability in a boson–fermion mixture superfluid in the unitary regime has been studied. The periodicity of the structure evolves with time. At ...the early stage of evolution, bosonic domains show the periodic nature, whereas the periodicity in the fermionic (Cooper pair) domains appears at the late stage of evolution. The nature of interatomic interspecies interactions affects the domain formation. In a harmonic trap, the mixture executes an undamped oscillation. The frequency of the oscillation depends on the relative coupling strength between boson–fermion and fermion–fermion. The repulsive boson–fermion interaction reduces the oscillation frequency, whereas the attractive interaction enhances the frequency significantly.
Lag structure in resting-state fMRI Mitra, A; Snyder, A Z; Hacker, C D ...
Journal of neurophysiology,
06/2014, Letnik:
111, Številka:
11
Journal Article
Recenzirano
Odprti dostop
The discovery that spontaneous fluctuations in blood oxygen level-dependent (BOLD) signals contain information about the functional organization of the brain has caused a paradigm shift in ...neuroimaging. It is now well established that intrinsic brain activity is organized into spatially segregated resting-state networks (RSNs). Less is known regarding how spatially segregated networks are integrated by the propagation of intrinsic activity over time. To explore this question, we examined the latency structure of spontaneous fluctuations in the fMRI BOLD signal. Our data reveal that intrinsic activity propagates through and across networks on a timescale of ∼1 s. Variations in the latency structure of this activity resulting from sensory state manipulation (eyes open vs. closed), antecedent motor task (button press) performance, and time of day (morning vs. evening) suggest that BOLD signal lags reflect neuronal processes rather than hemodynamic delay. Our results emphasize the importance of the temporal structure of the brain's spontaneous activity.
By starting from fundamental physical principles, a generalized theoretical framework was developed to engineer the intercalation-induced mechanical degradation in SEI-coated carbon particles from ...the surrounding electrolyte in rechargeable lithium-ion batteries (LIBs). Six elemental regimes of fracture formation in spherical electrochemically active carbon particles of radius,
r
p
, coated with an SEI layer of thickness,
δ
≪
r
p
, have been identified: The
pristine regime
, the
SEI debonding regime
, the
SEI surface flaw regime
, the
surface carbon flaw regime
(delithiation), the
internal circular carbon flaw regime
(lithiation), and the
carbon exfoliation regime
(lithiation); as well as four combined regimes during delithiation and four combined regimes during lithiation. Results are summarized in terms of C-Rate versus particle size, degradation maps, to identify LIB operation conditions where the performance can be optimized, while suppressing the decrepitation of the SEI-coated carbon particle system. Improved porous electrode layers that deliver longer battery life are possible by selecting electrolytes that considering the design of SEI-coated carbon particles of tailored elastic stiffness and critical stress intensity factor, so that they are safe from developing a chemomechanically induced flaw, exfoliation, or carbon re-forming, during both lithiation or delithiation in the 1 to 10
μ
m size particle, and C-Rates < 1 C.
Long non-coding RNAs (ncRNAs) have been shown to regulate important biological processes that support normal cellular functions. Aberrant regulation of these essential functions can promote tumor ...development. In this review, we underscore the importance of the regulatory role played by this distinct class of ncRNAs in cancer-associated pathways that govern mechanisms such as cell growth, invasion, and metastasis. We also highlight the possibility of using these unique RNAs as diagnostic and prognostic biomarkers in malignancies.
The long term outcome of stent implantation is affected by a process called in stent restenosis (ISR). Multiple contributory factors have been identified, but clear understanding of the overall ...underlying mechanism remains an enigma. ISR progresses through several different phases and involves numerous cellular and molecular constituents. Platelets and macrophages play a central role via vascular smooth muscle cell migration and proliferation in the intima to produce neointimal hyperplasia, which is pathognomic of ISR. Increased extracellular matrix formation appears to form the bulk of the neointimal hyperplasia tissue. Emerging evidence of the role of inflammatory cytokines and suppressors of cytokine signalling make this an exciting and novel field of antirestenosis research. Activation of Akt pathway triggered by mechanical stretch may also be a contributory factor to ISR formation. Prevention of ISR appears to be a multipronged attack as no therapeutic “magic bullet” exists to block all the processes in one go.
A total of 304 patients with severe secondary mitral regurgitation were randomly assigned to undergo percutaneous valve repair or to receive medical therapy. At 12 months, the rate of death or ...hospitalization for heart failure did not differ significantly between the groups.
Bismuth impregnation on pure TiO2 (BiTiO2) was carried out and tested in microbial fuel cell (MFC) as photocathode catalyst. UV–Visible spectral observation confirmed higher catalytic activity of ...BiTiO2 under visible light irradiation with reduced band gap of 2.80 eV as compared to pure TiO2 (3.26 eV). Electrochemical impedance spectroscopy also showed two times higher exchange current density with lower charge transfer resistance for BiTiO2 (1.90 Ω) than pure TiO2 (3.95 Ω), thus confirming it as superior oxygen reduction reaction catalyst. MFC operated with BiTiO2 could generate a maximum power density of 224 mW m−2, which was higher than MFC with Pt as cathode catalyst (194 mW m−2) and much higher than MFCs with TiO2 catalyzed cathode (68 mW m−2) and without any cathode catalyst (60 mW m−2). The results thus promote Bi doped TiO2 as a superior low-cost alternative to the costly Pt catalyst to take this MFC technology forward for field application.
•Bi doped TiO2 (BiTiO2) was synthesized by incipient wet impregnation method.•Synthesized BiTiO2 tested in microbial fuel cell as photocathode catalyst.•Higher photocatalytic activity of BiTiO2 was observed compared to pure TiO2.•3.7 times higher power density in MFC with BiTiO2 catalyst than control MFC.•BiTiO2 as a low-cost alternative to the costly Platinum to produce same power.
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