3,860 research outputs found

    THE ROLE OF STREPTOCOCCUS GALLOLYTICUS SUBSPECIES GALLOLYTICUS IN COLON CANCER DEVELOPMENT

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    Colorectal cancer (CRC) is the third most common cancer in men and women and is also the third most common cause of cancer death. A large body of evidence points towards the possibility that bacteria can have a significant impact on the development of cancer. It has been suggested that Streptococcus gallolyticus subsp. gallolyticus, a group D streptococci, may play a role in the development of CRC. Sg, formerly S. bovis biotype I, has been shown to be highly associated with CRC. In observing patients with either Sg bacteremia or endocarditis it was found that 25-80% of patients with Sg bacteremia had tumors and 18-62% of patients with Sg endocarditis had colonic neoplasias. However, other closely related Streptococcal strains, such as S. pasterianus and S. infantarius, have not been shown to have this strong association with CRC. In fact, it has been shown that biotype I is more often associated with CRC (94%) as compared to biotype II (18%). This knowledge has important clinical implications, and yet little is known about the role of Sg on CRC and the underlying mechanisms. Here we show that mice treated with Sg had significantly more tumors, higher tumor burden and dysplasia grade, and increased cell proliferation and β-catenin level in colonic crypts compared to mice treated with control bacteria. Sg strains that promoted proliferation were also more efficient at adhering to CRC cell lines and colonizing a mouse model. Additionally, in human patients Sg was highly prevalent in CRC patients and tumor tissues had an increased Sg burden in comparison to normal adjacent tissues. These results provide exciting new information and establish a tumor-promoting role of Sg that involves specific bacterial and host factors

    Adaptive Backstepping Control for Fractional-Order Nonlinear Systems with External Disturbance and Uncertain Parameters Using Smooth Control

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    In this paper, we consider controlling a class of single-input-single-output (SISO) commensurate fractional-order nonlinear systems with parametric uncertainty and external disturbance. Based on backstepping approach, an adaptive controller is proposed with adaptive laws that are used to estimate the unknown system parameters and the bound of unknown disturbance. Instead of using discontinuous functions such as the sign\mathrm{sign} function, an auxiliary function is employed to obtain a smooth control input that is still able to achieve perfect tracking in the presence of bounded disturbances. Indeed, global boundedness of all closed-loop signals and asymptotic perfect tracking of fractional-order system output to a given reference trajectory are proved by using fractional directed Lyapunov method. To verify the effectiveness of the proposed control method, simulation examples are presented.Comment: Accepted by the IEEE Transactions on Systems, Man and Cybernetics: Systems with Minor Revision

    Condensation and superfluidity of dilute Bose gases with finite-range interaction

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    We investigate an ultracold and dilute Bose gas by taking into account a finite-range two-body interaction. The coupling constants of the resulting Lagrangian density are related to measurable scattering parameters by following the effective-field-theory approach. A perturbative scheme is then developed up to the Gaussian level, where both quantum and thermal fluctuations are crucially affected by finite-range corrections. In particular, the relation between spontaneous symmetry breaking and the onset of superfluidity is emphasized by recovering the renowned Landau's equation for the superfluid density in terms of the condensate one.Comment: 18 pages, 4 figures, invited contribution to New Journal of Physics Focus Issue on Quantum Transport in Ultracold Atom

    Correlations and enlarged superconducting phase of tt-J⊥J_\perp chains of ultracold molecules on optical lattices

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    We compute physical properties across the phase diagram of the tt-J⊥J_\perp chain with long-range dipolar interactions, which describe ultracold polar molecules on optical lattices. Our results obtained by the density-matrix renormalization group (DMRG) indicate that superconductivity is enhanced when the Ising component JzJ_z of the spin-spin interaction and the charge component VV are tuned to zero, and even further by the long-range dipolar interactions. At low densities, a substantially larger spin gap is obtained. We provide evidence that long-range interactions lead to algebraically decaying correlation functions despite the presence of a gap. Although this has recently been observed in other long-range interacting spin and fermion models, the correlations in our case have the peculiar property of having a small and continuously varying exponent. We construct simple analytic models and arguments to understand the most salient features.Comment: published version with minor modification

    Staging the tumor and staging the host: A two centre, two country comparison of systemic inflammatory responses of patients undergoing resection of primary operable colorectal cancer

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    Background: How systemic inflammation-based prognostic scores such as the modified Glasgow Prognostic Score (mGPS) and neutrophil:lymphocyte ratio (NLR) differ across populations of patients with colorectal cancer (CRC) remains unknown. The present study examined the mGPS and NLR in patients from United Kingdom (UK) and Japan. Methods: Patients undergoing resection of TNM I-III CRC in two centres in the UK and Japan were included. Differences in clinicopathological characteristics and mGPS (0-CRP≤10 mg/L, 1-CRP>10 mg/L, 2-CRP>10 mg/L, albumin<35 g/L) and NLR (≤5/>5) were examined. Results: Patients from UK (n = 581) were more likely to be female, high ASA and BMI, present as an emergency (all P < 0.01) and have higher T stage compared to those from Japan (n = 559). After controlling for differences in tumor and host characteristics, patients from Japan were less likely to be systemically inflamed (OR: mGPS: 0.37, 95%CI 0.27–0.50, P < 0.001; NLR: 0.53, 95%CI 0.35–0.79, P = 0.002). Conclusion: Systemic inflammatory responses differ between populations with colorectal cancer. Given their prognostic value, reporting of systemic inflammation-based scores should be incorporated into future studies reporting patient outcomes. Summary: Although the systemic inflammatory response is recognised as a prognostic factor in patients with colorectal cancer, it is not clear how these may differ between distinct geographical populations. The present study examines differences in the prevalence of elevated systemic inflammatory responses (modified Glasgow Prognostic Score and neutrophil:lymphocyte ratio) between two populations undergoing resection of colorectal cancer in the United Kingdom and Japan
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