91 research outputs found

    The Persistence Length of a Strongly Charged, Rod-like, Polyelectrolyte in the Presence of Salt

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    The persistence length of a single, intrinsically rigid polyelectrolyte chain, above the Manning condensation threshold is investigated theoretically in presence of added salt. Using a loop expansion method, the partition function is consistently calculated, taking into account corrections to mean-field theory. Within a mean-field approximation, the well-known results of Odijk, Skolnick and Fixman are reproduced. Beyond mean-field, it is found that density correlations between counterions and thermal fluctuations reduce the stiffness of the chain, indicating an effective attraction between monomers for highly charged chains and multivalent counterions. This attraction results in a possible mechanical instability (collapse), alluding to the phenomenon of DNA condensation. In addition, we find that more counterions condense on slightly bent conformations of the chain than predicted by the Manning model for the case of an infinite cylinder. Finally, our results are compared with previous models and experiments.Comment: 13 pages, 2 ps figure

    Serum acute phase proteins in cows with SARA (Subacute Ruminal Acidosis) suspect

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    The aim of this study was to evaluate the variations of Acute Phase Proteins (APPs) and other blood constituents during the onset of the sub-acute ruminal acidosis (SARA) pathological status. A total of 108 cows from 12 dairy herds were randomly selected and divided into three Groups of 36 animals each. All animals were subjected to a rumenocentesis. Group A was composed by subjects with a rumen pH>5.8, Group B was composed by subjects with a rumen pH ≤5.5≤5.8 and Group C was composed by subjects with a rumen pH<5.5. Blood samples were collected by jugular venipuncture and Haptoglobin (Hp), Serum Amyloid A (SAA), Total Proteins, Albumin and White Blood Cells (WBC) were determined. One-way ANOVA showed a statistical significance on Rumen pH, Hp, SAA. SARA seems not stimulate the APPs production from liver

    Elliptic flow of identified hadrons in Pb-Pb collisions at 1asNN = 2.76 TeV

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    The elliptic flow coefficient (v2) of identified particles in Pb-Pb collisions at 1asNN = 2.76 TeV was measured with the ALICE detector at the Large Hadron Collider (LHC). The results were obtained with the Scalar Product method, a two-particle corre- lation technique, using a pseudo-rapidity gap of | 06\u3b7| > 0.9 between the identified hadron under study and the reference particles. The v2 is reported for \u3c0\ub1, K\ub1, K0S, p+p, \u3c6, \u39b+\u39b, \u39e 12+\u39e+ and \u3a9 12+\u3a9+ in several collision centralities. In the low transverse momentum (pT) region, pT 3 GeV/c

    Modern sea surface productivity and temperature estimations off Chile as detected by coccolith accumulation rates

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    Recent coccoliths from 74 surface sediment samples recovered from the southeastern Pacific off Chile were examined quantitatively to investigate modern regional gradients of sea surface productivity and temperature. All findings are based on coccolith accumulation rates. Therefore an approach was designed to estimate recent sedimentation rates based on 210Pb and bulk chemistry analyses of the same set of surface samples. Highest total coccolith accumulation rates were found off north-central Chile, where seasonal upwelling takes place. Based on a multiple linear regression between calculated coccolith accumulation rates and World Ocean Atlas derived sea surface temperatures, a calibration model to reconstruct annual average temperatures of the uppermost 75 m of the water column is provided. The model was cross-validated and the SST estimates were compared with SST observed and SST estimates based on diatoms and planktonic foraminifera, showing a good correlation

    A RIETE registry analysis of recurrent thromboembolism and hemorrhage in patients with catheter-related thrombosis.

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    Few studies have investigated the treatment and the outcomes of patients with catheter-related thrombosis (CRT). The RIETE registry (Registro Informatizado de Enfermedad TromboEmbólica [Computerized Registry of Patients with Venous Thromboembolism]) is a prospective international registry of consecutive patients with objectively confirmed venous thromboembolism (VTE). We analyzed the characteristics, treatment, and outcomes of patients with CRT. Of 558 patients with CRT, 45 (8%) presented with a pulmonary embolism (PE) concomitantly. More patients had central line-associated thrombosis compared with port systems, but catheter type did not influence the risk of presenting with a PE. Patients with only CRT were more often prescribed low-molecular-weight heparin for the duration of their anticoagulant treatment compared with patients presenting with concomitant PE. VTE recurrences and major bleeding events occurred frequently during treatment with anticoagulation (7 per 100 patient-years and 8.9 per 100 patient years, respectively). The rates of fatal PE recurrences (1.85 per 100 patient-years) and fatal bleeding (2.32 per 100 patient-years) were similar. Patients with an additional transient risk factor for VTE had the lowest risk for VTE recurrences (odds ratio [OR], 0.07; 90% confidence interval [CI], 0.01-0.45) compared with patients with CRT and no additional transient risk factors. PE at presentation increased the risk of recurrent thrombosis by 2.4 times. Renal insufficiency was also an independent predictor of recurrent thrombosis (OR, 3.93; 90% CI, 2.0-7.7). The odds of recurrent thrombosis was decreased by 77% in patients who received anticoagulation therapy for &gt;90 days compared with patients with a shorter treatment (OR, 0.23; 90% CI, 0.1-0.56). Concomitant PE occurs less frequently in CRT than lower extremity deep venous thrombosis, but it is associated with a worse outcome. CRT occurs in high-risk patients, and duration of anticoagulation must be predicated on balancing these risks

    Hochfeste Sinterstaehle durch Fluessigphasensintern Schlussbericht. Abschlussdatum: April 1981

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    TIB: RN 2598 (83-139)+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman
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