135 research outputs found

    Two photon decays of heavy vector mesons, BBγγB^{*}\to B\gamma \gamma,DDγγD^{*}\to D\gamma \gamma, and the possible determination of the gB(D)B(D)πg_{B^{*}(D^{*})B(D)\pi} and gB0B0γg_{{B^{*}}^0B^0\gamma} couplings

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    We study the novel decays BBγγB^{*}\to B\gamma\gamma and DDγγD^{*}\to D\gamma \gamma using the framework of the Heavy Meson Chiral Lagrangian (HMχ\chiL) to leading order in chiral perturbation theory. The branching ratios of these decays are expressed in terms of the strong gB(D)B(D)πg_{B^{*}(D^{*})B(D)\pi} and the electromagnetic gB(D)B(D)γg_{B^{*}(D^*)B(D)\gamma} couplings, thus providing a possible tool for their determination. In the charm case, using the experimentally determined ratios (D0,+Dπ)/(D0,+Dγ),({D^*}^{0,+}\to D\pi)/({D^*}^{0,+}\to D\gamma), we are able to express the branching ratio as a function of the strong coupling only. We thus find 1.6×106<Br(D0D0γγ)<3.3×1051.6\times 10^{-6}<{\rm Br} ({D^{*}}^{0}\to D^0\gamma\gamma)<3.3\times 10^{-5} for 0.25<g<1,0.25<g<1, where gg is the strong coupling of HMχ\chiL. In the beauty sector, the Br(B0B0γγ){\rm Br}({B^{*}}^{0} \to B^0 \gamma\gamma) which we estimate to be in the 10710510^{-7}-10^{-5} range is a function of both gBBπg_{B^{*}B\pi} and gBBγ.g_{B^{*}B\gamma}. Its behaviour does not afford an unambiguous determination of these couplings except for the region of high gg values like g>0.6.g>0.6. The expected two-photon differential distributions are presented for both B0B0γγ{B^{*}}^{0} \to B^0 \gamma\gamma and D0D0γγ,{D^{*}}^{0}\to D^0\gamma\gamma, for different values of the couplings involved.Comment: 22 pages, LaTeX, 5 ps-figures (uses subfigure.sty). Accepted by Phys. Rev.

    Phosphorus Is Associated with Coronary Artery Disease in Patients with Preserved Renal Function

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    High serum phosphorus levels have been associated with mortality and cardiovascular events in patients with chronic kidney disease and in the general population. In addition, high phosphorus levels have been shown to induce vascular calcification and endothelial dysfunction in vitro. The aim of this study was to evaluate the relation of phosphorus and coronary calcification and atherosclerosis in the setting of normal renal function. This was a cross-sectional study involving 290 patients with suspected coronary artery disease and undergoing elective coronary angiography, with a creatinine clearance >60 ml/min/1.73 m2. Coronary artery obstruction was assessed by the Friesinger score and coronary artery calcification by multislice computed tomography. Serum phosphorus was higher in patients with an Agatston score >10 than in those with an Agatston score ≤10 (3.63±0.55 versus 3.49±0.52 mg/dl; p = 0.02). In the patients with Friesinger scores >4, serum phosphorus was higher (3.6±0.5 versus 3.5±0.6 mg/dl, p = 0.04) and median intact fibroblast growth factor 23 was lower (40.3 pg/ml versus 45.7 pg/ml, p = 0.01). Each 0.1-mg/dl higher serum phosphate was associated with a 7.4% higher odds of having a Friesinger score >4 (p = 0.03) and a 6.1% greater risk of having an Agatston score >10 (p = 0.01). Fibroblast growth factor 23 was a negative predictor of Friesinger score (p = 0.002). In conclusion, phosphorus is positively associated with coronary artery calcification and obstruction in patients with suspected coronary artery disease and preserved renal function

    Circulating MicroRNAs Are Not Eliminated by Hemodialysis

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    BACKGROUND: Circulating microRNAs are stably detectable in serum/plasma and other body fluids. In patients with acute kidney injury on dialysis therapy changes of miRNA patterns had been detected. It remains unclear if and how the dialysis procedure itself affects circulating microRNA level. METHODS: We quantified miR-21 and miR-210 by quantitative RT-PCR in plasma of patients with acute kidney injury requiring dialysis and measured pre- and post-dialyser miRNA levels as well as their amount in the collected spent dialysate. Single treatments using the following filters were studied: F60 S (1.3 m(2), Molecular Weight Cut Off (MWCO): 30 kDa, n = 8), AV 1000 S (1.8 m(2), MWCO: 30 kDa, n = 6) and EMiC 2 (1.8 m(2), MWCO: 40 kDa, n = 6). RESULTS: Circulating levels of miR-21 or -210 do not differ between pre- and post-dialyzer blood samples independently of the used filter surface and pore size: miR-21: F60S: p = 0.35, AV 1000 S p = 1.0, EMiC2 p = 1.0; miR-210: F60S: p = 0.91, AV 1000 S p = 0.09, EMiC2 p = 0.31. Correspondingly, only traces of both miRNAs could be found in the collected spent dialysate and ultrafiltrate. CONCLUSIONS: In patients with acute kidney injury circulating microRNAs are not removed by dialysis. As only traces of miR-21 and -210 are detected in dialysate and ultrafiltrate, microRNAs in the circulation are likely to be transported by larger structures such as proteins and/or microvesicles. As miRNAs are not affected by dialysis they might be more robust biomarkers of acute kidney injury

    Hypoxia Inducible Factor 1-Alpha (HIF-1 Alpha) Is Induced during Reperfusion after Renal Ischemia and Is Critical for Proximal Tubule Cell Survival

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    Acute tubular necrosis (ATN) caused by ischemia/reperfusion (I/R) during renal transplantation delays allograft function. Identification of factors that mediate protection and/or epithelium recovery could help to improve graft outcome. We studied the expression, regulation and role of hypoxia inducible factor 1-alpha (HIF-1 α), using in vitro and in vivo experimental models of I/R as well as human post-transplant renal biopsies. We found that HIF-1 α is stabilized in proximal tubule cells during ischemia and unexpectedly in late reperfusion, when oxygen tension is normal. Both inductions lead to gene expression in vitro and in vivo. In vitro interference of HIF-1 α promoted cell death and in vivo interference exacerbated tissue damage and renal dysfunction. In pos-transplant human biopsies, HIF-1 α was expressed only in proximal tubules which exhibited normal renal structure with a significant negative correlation with ATN grade. In summary, using experimental models and human biopsies, we identified a novel HIF-1 α induction during reperfusion with a potential critical role in renal transplant

    Micromechanical Properties of Injection-Molded Starch–Wood Particle Composites

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    The micromechanical properties of injection molded starch–wood particle composites were investigated as a function of particle content and humidity conditions. The composite materials were characterized by scanning electron microscopy and X-ray diffraction methods. The microhardness of the composites was shown to increase notably with the concentration of the wood particles. In addition,creep behavior under the indenter and temperature dependence were evaluated in terms of the independent contribution of the starch matrix and the wood microparticles to the hardness value. The influence of drying time on the density and weight uptake of the injection-molded composites was highlighted. The results revealed the role of the mechanism of water evaporation, showing that the dependence of water uptake and temperature was greater for the starch–wood composites than for the pure starch sample. Experiments performed during the drying process at 70°C indicated that the wood in the starch composites did not prevent water loss from the samples.Peer reviewe

    Controversies in acute kidney injury: conclusions from a Kidney Disease: Improving Global Outcomes (KDIGO) conference

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    In 2012, Kidney Disease: Improving Global Outcomes (KDIGO) published a guideline on the classification and management of acute kidney injury (AKI). The guideline was derived from evidence available through February 2011. Since then, new evidence has emerged that has important implications for clinical practice in diagnosing and managing AKI. In April of 2019, KDIGO held a controversies conference entitled Acute Kidney Injury with the following goals: determine best practices and areas of uncertainty in treating AKI; review key relevant literature published since the 2012 KDIGO AKI guideline; address ongoing controversial issues; identify new topics or issues to be revisited for the next iteration of the KDIGO AKI guideline; and outline research needed to improve AKI management. Here, we present the findings of this conference and describe key areas that future guidelines may address

    Incidence and mortality of acute kidney injury after myocardial infarction: a comparison between KDIGO and RIFLE criteria.

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    BACKGROUND: Acute kidney injury (AKI) increases the risk of death after acute myocardial infarction (AMI). Recently, a new AKI definition was proposed by the Kidney Disease Improving Global Outcomes (KDIGO) organization. The aim of the current study was to compare the incidence and the early and late mortality of AKI diagnosed by RIFLE and KDIGO criteria in the first 7 days of hospitalization due to an AMI. METHODS AND RESULTS: In total, 1,050 AMI patients were prospectively studied. AKI defined by RIFLE and KDIGO occurred in 14.8% and 36.6% of patients, respectively. By applying multivariate Cox analysis, AKI was associated with an increased adjusted hazard ratio (AHR) for 30-day death of 3.51 (95% confidence interval [CI] 2.35-5.25, p<0.001) by RIFLE and 3.99 (CI 2.59-6.15, p<0.001) by KDIGO and with an AHR for 1-year mortality of 1.84 (CI 1.12-3.01, p=0.016) by RIFLE and 2.43 (CI 1.62-3.62, p<0.001) by KDIGO. The subgroup of patients diagnosed as non-AKI by RIFLE but as AKI by KDIGO criteria had also an increased AHR for death of 2.55 (1.52-4.28) at 30 days and 2.28 (CI 1.46-3.54) at 1 year (p<0.001). CONCLUSIONS: KDIGO criteria detected substantially more AKI patients than RIFLE among AMI patients. Patients diagnosed as AKI by KDIGO but not RIFLE criteria had a significantly higher early and late mortality. In this study KDIGO criteria were more suitable for AKI diagnosis in AMI patients than RIFLE criteria

    Ertapenem versus Ceftriaxone Followed by Appropriate Oral Therapy for Treatment of Complicated Urinary Tract Infections in Adults: Results of a Prospective, Randomized, Double-Blind Multicenter Study

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    The efficacy and safety of intravenous (i.v.) ertapenem (1 g once a day) with the option to switch to an oral agent for treatment of adults with complicated urinary tract infections (UTIs) were compared with that of i.v. ceftriaxone (1 g daily) with the same oral switch option in a multicenter, double-blind, prospective, randomized study. At entry, 592 patients were assigned to one of two strata: acute pyelonephritis or other complicated UTI without acute pyelonephritis. After a minimum of 3 days, patients could be switched to an oral antimicrobial agent. A total of 159 patients in the ertapenem group and 171 patients in the ceftriaxone group were microbiologically evaluable. Approximately 95% of patients in each treatment group were switched to oral therapy. The most common pathogens were Escherichia coli and Klebsiella pneumoniae. At the primary efficacy endpoint 5 to 9 days after treatment, 91.8% of patients who received ertapenem and 93.0% of those who received ceftriaxone had a favorable microbiological response (95% confidence interval for the difference, adjusting for strata, −7.6 to 5.1%), indicating that outcomes in the two treatment groups were equivalent. Microbiological success rates for the two treatment groups were similar when compared by stratum and also by severity of infection. The frequency and severity of drug-related adverse events were generally similar in both treatment groups. In this study, ertapenem was as effective as ceftriaxone for the initial treatment of complicated UTIs in adults, was generally well tolerated, and had a similar overall safety profile

    Acute renal failure and the sepsis syndrome

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    Universidade Federal de São Paulo, Escola Paulista Med, Disciplina Nefrol, BR-04023900 São Paulo, BrazilTufts Univ, Sch Med, Boston, MA 02111 USAUniv São Paulo, Inst Ciencias Biol, São Paulo, BrazilUniv Rio de Janeiro, UNI Rio, Rio de Janeiro, BrazilSao Jose Do Roi Preto Med Sch, São Paulo, BrazilEscola Baiana Med & Saude Publ, Salvador, BA, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Disciplina Nefrol, BR-04023900 São Paulo, BrazilWeb of Scienc
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