4,752 research outputs found

    Myocardial survival and function under conditions of anoxia

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    Thesis (M.A.)--Boston UniversityRat heart muscle was subjected to quantitated conditions of anoxia achieved by extracting oxygen from Ringer's solution under vacuum and heat. Special Van Slyke analyses measured the amount of oxygen remaining in solution after the extraction procedures had been carried out. Myocardial response to anoxia was studied in terms of survival, or the ability of the heart tissue to remain alive during anoxia with resumption of function when placed in an oxygenated environment, and in terms of function, or the ability of heart muscle to contract during anoxia [TRUNCATED

    A-infinity algebra of an elliptic curve and Eisenstein series

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    We compute explicitly the A-infinity structure on the Ext-algebra of the collection (OC,L)({\mathcal O}_C, L), where LL is a line bundle of degree 1 on an elliptic curve CC. The answer involves higher derivatives of Eisenstein series.Comment: 13 pages, 3 figures; v3: added remark on the limit at the cus

    Prostate cancer treatment with Irreversible Electroporation (IRE): Safety, efficacy and clinical experience in 471 treatments.

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    BackgroundIrreversible Electroporation (IRE) is a novel image-guided tissue ablation technology that induces cell death via very short but strong pulsed electric fields. IRE has been shown to have preserving properties towards vessels and nerves and the extracellular matrix. This makes IRE an ideal candidate to treat prostate cancer (PCa) where other treatment modalities frequently unselectively destroy surrounding structures inducing severe side effects like incontinence or impotence. We report the retrospective assessment of 471 IRE treatments in 429 patients of all grades and stages of PCa with 6-year maximum follow-up time.Material and findingsThe patient cohort consisted of low (25), intermediate (88) and high-risk cancers (312). All had multi-parametric magnetic resonance imaging, and 199 men had additional 3D-mapping biopsy for diagnostic work-up prior to IRE. Patients were treated either focally (123), sub-whole-gland (154), whole-gland (134) or for recurrent disease (63) after previous radical prostatectomy, radiation therapy, etc. Adverse effects were mild (19.7%), moderate (3.7%) and severe (1.4%), never life-threatening. Urinary continence was preserved in all cases. IRE-induced erectile dysfunction persisted in 3% of the evaluated cases 12 months post treatment. Mean transient IIEF-5-Score reduction was 33% within 12-month post IRE follow-up and 15% after 12 months. Recurrences within the follow-up period occurred in 10% of the treated men, 23 in or adjacent to the treatment field and 18 outside the treatment field (residuals). Including residuals for worst case analysis, Kaplan Maier estimation on recurrence rate at 5 years resulted in 5.6% (CI95: 1.8-16.93) for Gleason 6, 14.6% (CI95: 8.8-23.7) for Gleason 7 and 39.5% (CI95: 23.5-61.4) for Gleason 8-10.ConclusionThe results indicate comparable efficacy of IRE to standard radical prostatectomy in terms of 5-year recurrence rates and better preservation of urogenital function, proving the safety and suitability of IRE for PCa treatment. The data also shows that IRE, besides focal therapy of early PCa, can also be used for whole-gland ablations, in patients with recurrent PCa, and as a problem-solver for local tumor control in T4-cancers not amenable to surgery and radiation therapy anymore

    Painleve versus Fuchs

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    The sigma form of the Painlev{\'e} VI equation contains four arbitrary parameters and generically the solutions can be said to be genuinely ``nonlinear'' because they do not satisfy linear differential equations of finite order. However, when there are certain restrictions on the four parameters there exist one parameter families of solutions which do satisfy (Fuchsian) differential equations of finite order. We here study this phenomena of Fuchsian solutions to the Painlev{\'e} equation with a focus on the particular PVI equation which is satisfied by the diagonal correlation function C(N,N) of the Ising model. We obtain Fuchsian equations of order N+1N+1 for C(N,N) and show that the equation for C(N,N) is equivalent to the NthN^{th} symmetric power of the equation for the elliptic integral EE. We show that these Fuchsian equations correspond to rational algebraic curves with an additional Riccati structure and we show that the Malmquist Hamiltonian p,qp,q variables are rational functions in complete elliptic integrals. Fuchsian equations for off diagonal correlations C(N,M)C(N,M) are given which extend our considerations to discrete generalizations of Painlev{\'e}.Comment: 18 pages, Dedicated to the centenary of the publication of the Painleve VI equation in the Comptes Rendus de l'Academie des Sciences de Paris by Richard Fuchs in 190

    A central limit theorem for the zeroes of the zeta function

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    On the assumption of the Riemann hypothesis, we generalize a central limit theorem of Fujii regarding the number of zeroes of Riemann's zeta function that lie in a mesoscopic interval. The result mirrors results of Soshnikov and others in random matrix theory. In an appendix we put forward some general theorems regarding our knowledge of the zeta zeroes in the mesoscopic regime.Comment: 22 pages. Incorporates referees suggestions. Contains minor corrections to published versio

    Nanotoxicity and life cycle assessment: First attempt towards the determination of characterization factors for carbon nanotubes

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    Carbon materials, whether at macro, micro or at nanoscale, play an important role in the battery industry, as they can be used as electrodes, electrode enhancers, bipolar separators, or current collectors. When conducting a Life Cycle Assessment (LCA) of novel batteries manufacturing processes, we also need to consider the fate of potentially emitted carbon based nanomaterials. However, the knowledge generated in the last decade regarding the behavior of such materials in the environment and its toxicological effects has yet to be included in the Life Cycle Impact Assessment (LCIA) methodologies. Conventional databases of chemical products (e.g. ECHA, ECOTOX) offer little information regarding engineered nanomaterials (ENM). It is thus necessary to go one step further and compile physicochemical and toxicological data directly from scientific literature. Such studies do not only differ in their results, but also in their methodologies, and several calls have been made towards a more consistent approach that would allow us model the fate of ENM in the environment as well as their potentially harmful effects. Trying to overcome these limitations we have developed a tool based on Microsoft Excel® combining several methods for the estimation of physicochemical properties of carbon nanotubes (CNT). The information generated with this tool is combined with degradation rates and toxicological data consistent with the methods followed by the USEtox methodology. Thus, it is possible to calculate the characterization factors of CNTs and integrate them as a first proxy in future LCA of products including these ENM

    Mg II Absorption Systems in SDSS QSO Spectra

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    We present the results of a MgII absorption-line survey using QSO spectra from the SDSS EDR. Over 1,300 doublets with rest equivalent widths greater than 0.3\AA and redshifts 0.366≤z≤2.2690.366 \le z \le 2.269 were identified and measured. We find that the λ2796\lambda2796 rest equivalent width (W0λ2796W_0^{\lambda2796}) distribution is described very well by an exponential function ∂N/∂W0λ2796=N∗W∗e−W0W∗\partial N/\partial W_0^{\lambda2796} = \frac{N^*}{W^*} e^{-\frac{W_0}{W^*}}, with N∗=1.187±0.052N^*=1.187\pm0.052 and W∗=0.702±0.017W^*=0.702\pm0.017\AA. Previously reported power law fits drastically over-predict the number of strong lines. Extrapolating our exponential fit under-predicts the number of W0≤0.3W_0 \le 0.3\AA systems, indicating a transition in dN/dW0dN/dW_0 near W0≃0.3W_0 \simeq 0.3\AA. A combination of two exponentials reproduces the observed distribution well, suggesting that MgII absorbers are the superposition of at least two physically distinct populations of absorbing clouds. We also derive a new redshift parameterization for the number density of W0λ2796≥0.3W_0^{\lambda2796} \ge 0.3\AA lines: N∗=1.001±0.132(1+z)0.226±0.170N^*=1.001\pm0.132(1+z)^{0.226\pm0.170} and W∗=0.443±0.032(1+z)0.634±0.097W^*=0.443\pm0.032(1+z)^{0.634\pm 0.097}\AA. We find that the distribution steepens with decreasing redshift, with W∗W^* decreasing from 0.80±0.040.80\pm0.04\AA at z=1.6z=1.6 to 0.59±0.020.59\pm0.02\AA at z=0.7z=0.7. The incidence of moderately strong MgII λ2796\lambda2796 lines does not show evidence for evolution with redshift. However, lines stronger than ≈2\approx 2\AA show a decrease relative to the no-evolution prediction with decreasing redshift for z≲1z \lesssim 1. The evolution is stronger for increasingly stronger lines. Since W0W_0 in saturated absorption lines is an indicator of the velocity spread of the absorbing clouds, we interpret this as an evolution in the kinematic properties of galaxies from moderate to low z.Comment: 50 pages, 26 figures, accepted for publication in Ap
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