378 research outputs found

    Theory of high energy features in angle-resolved photo-emission spectra of hole-doped cuprates

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    The recent angle-resolved photoemission measurements performed up to binding energies of the order of 1eV reveals a very robust feature: the nodal quasi-particle dispersion breaks up around 0.3-0.4eV and reappears around 0.6-0.8eV. The intensity map in the energy-momentum space shows a waterfall like feature between these two energy scales. We argue and numerically demonstrate that these experimental features follow naturally from the strong correlation effects built in the familiar t-J model, and reflect the connection between the fermi level and the lower Hubbard band. The results were obtained by a mean field theory that effectively projects electrons by quantum interference between two bands of fermions instead of binding slave particles.Comment: 5 pages 2 fig

    The effect of goal-directed therapy on mortality in patients with sepsis - earlier is better: A meta-analysis of randomized controlled trials

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    __Introduction:__ The Surviving Sepsis Campaign guidelines recommend goal-directed therapy (GDT) for the early resuscitation of patients with sepsis. However, the findings of the ProCESS (Protocolized Care for Early Septic Shock) trial showed no benefit from GDT for reducing mortality rates in early septic shock. We performed a meta-analysis to integrate these findings with existing literat

    The impact of uncorrected mild aortic insufficiency at the time of left ventricular assist device implantation

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    OBJECTIVE: The study objective was to investigate the progression of uncorrected mild aortic insufficiency and its impact on survival and functional status after left ventricular assist device implantation. METHODS: We retrospectively reviewed 694 consecutive patients who underwent implantation of a continuous-flow left ventricular assist device between January 2006 and March 2018. Pre-left ventricular assist device transthoracic echocardiography identified 111 patients with mild aortic insufficiency and 493 patients with trace or no aortic insufficiency. To adjust for differences in preoperative factors, propensity score matching was used, resulting in 101 matched patients in each of the mild aortic insufficiency and no aortic insufficiency groups. RESULTS: Although both groups showed similar survival (P = .58), the mild aortic insufficiency group experienced higher incidence of readmission caused by heart failure (hazard ratio, 2.62; 95% confidence interval, 1.42-4.69; P \u3c .01). By using the mixed effect model, pre-left ventricular assist device mild aortic insufficiency was a significant risk factor for both moderate or greater aortic insufficiency and worsening New York Heart Association functional status (P \u3c .01). CONCLUSIONS: Patients with uncorrected mild aortic insufficiency had a higher risk of progression to moderate or greater aortic insufficiency after left ventricular assist device implantation with worse functional status and higher incidence of readmission caused by heart failure compared with patients without aortic insufficiency. Further investigations into the safety and efficacy of concomitant aortic valve procedures for mild aortic insufficiency at the time of left ventricular assist device implant are warranted to improve patients\u27 quality of life, considering the longer left ventricular assist device use as destination therapy and bridge to transplant with the new US heart allocation system

    Prospective associations between accelerometry-derived physical activity and sedentary behaviors and mortality among cancer survivors

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    BACKGROUND: Survival benefits of self-reported recreational physical activity (PA) during cancer survivorship are well-documented in common cancer types, yet there are limited data on the associations between accelerometer-derived PA of all domains, sedentary behavior, and mortality in large, diverse cohorts of cancer survivors. METHODS: Participants included adults who reported a cancer diagnosis in the National Health and Nutrition Examination Survey and wore an accelerometer for up to 7 days in 2003-2006. Participants were followed for subsequent mortality through 2015. We examined the association of light PA, moderate to vigorous PA, total PA, and sedentary behavior, with all-cause mortality. Cox proportional hazards models estimated hazard ratios (HRs) and 95% confidence intervals (CIs), adjusting for demographics and health indicators. RESULTS: A total of 480 participants (mean age of 68.8 years [SD = 12.4] at the time of National Health and Nutrition Examination Survey assessment) reported a history of cancer. A total of 215 deaths occurred over the follow-up period. For every 1-h/d increase in light PA and moderate to vigorous PA (MVPA), cancer survivors had 49% (HR = 0.51, 95% CI = 0.34 to 0.76) and 37% (HR = 0.63 , 95% CI = 0.40 to 0.99) lower hazards of all-cause mortality, respectively. Total PA demonstrated similar associations with statistically significantly lower hazards of death for each additional hour per day (HR = 0.68, 95% CI = 0.54 to 0.85), as did every metabolic equivalents of task-hour per day increase in total PA estimations of energy expenditure (HR = 0.88, 95% CI = 0.82 to 0.95). Conversely, more sedentary time (1 h/d) was not associated with statistically significantly higher hazards (HR = 1.08, 95% CI = 0.94 to 1.23). CONCLUSIONS: These findings reinforce the current recommendations for cancer survivors to be physically active and underscore the continued need for widespread PA promotion for long-term survival in older cancer survivors

    Systematic review of the effect of reflective materials around a phototheraphy unit on biirubin reduction among neonates with physiologic jaundice in developing countries

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    Objective: To identify the efficacy and safety of the use of various cost-effective reflective materials around phototherapy units to reduce the duration of phototherapy and hasten the reduction of bilirubin among neonates with physiologic jaundice. Data Sources: A systematic review of randomized controlled trials identified from searches in the Cumulative Index to Nursing and Allied Health Literature, Science Direct, Embase, and the Cochrane Library with the use of keywords, MeSH terms, operators, and the review of reference lists of retrieved articles. Study Selection: From a total of 186 studies initially screened, five were eventually included in this analysis. Data Extraction: Two authors independently reviewed each study with a standard template. Review parameters included the quality of each study based on the Physiotherapy Evidence Database scale and the Consolidated Standards of Reporting Trials guidelines. Data Synthesis: All studies were generalizable and were rated as high quality on the Physiotherapy Evidence Database scale; one study scored 8 points, and the other four scored 6 points each. The reflective materials used in these studies included the following: white 100% cotton cloths (one study), white plastic covers (two studies), underpads (one study), and silver fabric cloth (one study). Pooled analysis of three studies indicated that reflective materials significantly reduced the duration of phototherapy with a large effect size of 0.82 (p =.04). Pooled analysis of another three studies indicated that the mean decrease of the total serum bilirubin 4 hours after the initiation of phototherapy was significantly greater when reflective materials were added (mean difference of 11.39 μmol/L, 95% confidence interval [2.26, 20.52 μmol/L], p =.01). Conclusion: The addition of reflective materials to phototherapy units may be therapeutic for neonates with physiologic jaundice

    Structural and transport properties of Sr2VO{3-delta}FeAs superconductors with different oxygen deficiencies

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    Sr2VO{3-delta}FeAs superconductors with different oxygen deficiencies have been successfully fabricated. It is found that the superconducting transition temperature drops down monotonically with the increase of oxygen deficiency. The diminishing of superconductivity is accompanied by the enhancement of residual resistivity, indicating an unraveled scattering effect induced by the oxygen deficiency. The highest superconducting transition temperature at about 40 K is achieved near the stoichiometrical sample Sr2_2VO3_{3}FeAs. Surprisingly, the X-ray photoelectron spectroscopy (XPS) shows that the vanadium has a "5+" valence state in the samples. The Hall effect measurements reveal that the density of charge carriers (electron-like here) varies qualitatively with the increase of oxygen deficiency. Magnetotransport measurements show that the superconducting transition changes from one-step-like shape at low fields to two-step-like one at high fields, indicating a high anisotropy.Comment: 6 pages, 6 figure

    Pulmonary-to-Systemic Arterial Shunt to Treat Children With Severe Pulmonary Hypertension

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    BACKGROUND: The placement of a pulmonary-to-systemic arterial shunt in children with severe pulmonary hypertension (PH) has been demonstrated, in relatively small studies, to be an effective palliation for their disease. OBJECTIVES: The aim of this study was to expand upon these earlier findings using an international registry for children with PH who have undergone a shunt procedure. METHODS: Retrospective data were obtained from 110 children with PH who underwent a shunt procedure collected from 13 institutions in Europe and the United States. RESULTS: Seventeen children died in-hospital postprocedure (15%). Of the 93 children successfully discharged home, 18 subsequently died or underwent lung transplantation (20%); the mean follow-up was 3.1 years (range: 25 days to 17 years). The overall 1- and 5-year freedom from death or transplant rates were 77% and 58%, respectively, and 92% and 68% for those discharged home, respectively. Children discharged home had significantly improved World Health Organization functional class (P < 0.001), 6-minute walk distances (P = 0.047) and lower brain natriuretic peptide levels (P < 0.001). Postprocedure, 59% of children were weaned completely from their prostacyclin infusion (P < 0.001). Preprocedural risk factors for dying in-hospital postprocedure included intensive care unit admission (hazard ratio [HR]: 3.2; P = 0.02), mechanical ventilation (HR: 8.3; P < 0.001) and extracorporeal membrane oxygenation (HR: 10.7; P < 0.001). CONCLUSIONS: A pulmonary-to-systemic arterial shunt can provide a child with severe PH significant clinical improvement that is both durable and potentially free from continuous prostacyclin infusion. Five-year survival is comparable to children undergoing lung transplantation for PH. Children with severely decompensated disease requiring aggressive intensive care are not good candidates for the shunt procedure

    Evaluation of several adjuvants in avian influenza vaccine to chickens and ducks

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    The effects of three different adjuvants, mineral oil, Montanide™ ISA 70M VG, and Montanide™ ISA 206 VG, were evaluated on reverse genetics H5N3 avian influenza virus cell cultured vaccine. The immune results of SPF chickens after challenging with highly pathogenic avian influenza (HPAI) virus demonstrated that mineral oil adjuvant group and 70M adjuvant group provided 100% protection efficiency, but 206 adjuvant group provided only 40%. Statistical analysis indicated that the protection effects of mineral oil adjuvant group and the 70M adjuvant showed no significant difference to each other, but with significant difference to 206 adjuvant group. All three groups could induce high titres of antibody after immunizing SPF ducks, but there was no significant difference among them. The immunization effect of 70M adjuvant group on SPF chickens were the best and showed significant difference compared with optimized 70Mi Montanide™ eight series adjuvants groups. These results suggest that 70M adjuvant could be a novel adjuvant for preparing avian influenza vaccine
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