Signatures of Dissipation Driven Quantum Phase Transition in Rabi Model.

By using the worldline Monte Carlo technique, matrix product state, and a variational approach à la Feynman, we investigate the equilibrium properties and relaxation features of the dissipative quantum Rabi model, where a two level system is coupled to a linear harmonic oscillator embedded in a viscous fluid. We show that, in the Ohmic regime, a Beretzinski-Kosterlitz-Thouless quantum phase transition occurs by varying the coupling strength between the two level system and the oscillator. This is a nonperturbative result, occurring even for extremely low dissipation magnitude. By using state-of-the-art theoretical methods, we unveil the features of the relaxation towards the thermodynamic equilibrium, pointing out the signatures of quantum phase transition both in the time and frequency domains. We prove that, for low and moderate values of the dissipation, the quantum phase transition occurs in the deep strong coupling regime. We propose to realize this model by coupling a flux qubit and a damped LC oscillator.

Minimal clinically important difference of the 6-min walking test in patients with asthma.

BACKGROUND: The 6-min walking test (6MWT) is responsive to physiological changes and pulmonary rehabilitation (PR) in patients with asthma. The minimal clinically important difference (MCID) has not been established yet.OBJECTIVE: To determine the MCID of 6MWT in patients with asthma.METHODS: Using the perceived change in walking ability and the modified Medical Research Council (mMRC) score as anchors, receiver operating characteristic curves and quantile regression, we evaluated 6MWT before and after PR in these patients. The St George Respiratory Questionnaire (SGRQ), the COPD assessment test (CAT) and other outcome measures were also assessed.RESULTS: Of 142 patients with asthma, 37 were enrolled. After PR, 6MWT increased from 453.4 m ± 88.8 to 493.0 m ± 97.2 (P = 0.0001); other outcome measures also increased. There was a slight correlation between baseline 6MWT and SGRQ, CAT and mMRC. No significant correlations were found between post-PR changes in 6MWT and in other outcome measures. Comparing different methods of assessment, the MCID ranged from 26 m to 27 m.CONCLUSION: The most conservative estimate of the MCID of 6MWT after PR was 26 m in patients with asthma. This estimate may be useful in clinical interpretation of data, particularly in response to intervention studies.

Serosurvey on Sheep Unravel Circulation of Rift Valley Fever Virus in Nigeria.

Rift Valley fever is an arboviral zoonoses causing severe morbidity and mortality among humans and animals in many African countries. A cross-sectional study in populations of sheep reared around the Gidan-Waya Forest Reserve located in Jema'a LGA of Kaduna State, Nigeria to determine the serological evidence of exposure to Rift Valley fever virus (RVFV) using a commercial competitive enzyme-linked immunosorbent assay. Of the 200 sheep sampled, 9 (4.5%; 95 CI 2.23-8.33) were positive for antibodies to the RVFV. The detection of antibodies suggests a covert circulation among the sheep and may be indicative of a subclinical infection.

Agitated saline echo testing: Two useful indications in critical care patients / Ecocardiograma con solución salina agitada: dos indicaciones útiles en pacientes críticos

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Clinical and microbiological outcome in septic patients with extremely low 25-hydroxyvitamin D levels at initiation of critical care.

A relationship between vitamin D status and mortality in patients in intensive care units (ICU) has been documented. The present study aims to describe the clinical profile and sepsis-related outcome of critically ill septic patients with extremely low (<7 ng/mL) vitamin D levels at ICU admission. We conducted an observational study in the ICU of a teaching hospital including all patients admitted with severe sepsis/septic shock and undergoing 25-hydroxyvitamin D (25(OH)D) testing within the first 24 hours from admission. We studied 107 patients over 12 months. At ICU admission vitamin D deficiency (≤20 ng/mL) was observed in 93.5% of the patients: 57 (53.3%) showed levels <7 ng/mL. As primary outcome, sepsis-related mortality rate was higher in patients with vitamin D levels <7 ng/mL (50.9% versus 26%). Multivariate regression analysis showed that vitamin D concentration <7 ng/mL on ICU admission (p 0.01) and higher mean SAPS II (p <0.01) score were independent predictors of sepsis-related mortality. Patients with very low vitamin D levels suffered higher rate of microbiologically confirmed infections but a lower percentage of microbiological eradication with respect to patients whose values were >7 ng/mL (80.7% versus 58%, p 0.02; 35.3% versus 68%; p 0.03, respectively). Post hoc analysis showed that, in the extremely low vitamin D group, the 52 patients with pneumonia showed a longer duration of mechanical ventilation (9 days (3.75-12.5 days) versus 4 days (2-9 days), p 0.04) and the 66 with septic shock needed vasopressor support for a longer period of time (7 days (4-10 days) versus 4 days (2-7.25 days), p 0.02). Our results suggest that in critical septic patients extremely low vitamin D levels on admission may be a major determinant of clinical outcome. Benefits of vitamin D replacement therapy in this population should be elucidated.

Epidemic history of major genotypes of hepatitis C virus in Uruguay.

Worldwide, more than 170 million people are chronically infected with the hepatitis C virus (HCV) and every year die more than 350,000 people from HCV-related liver diseases. Recently, HCV was reclassified into seven major genotypes and 67 subtypes. Some subtypes as 1a, 1b and 3a, have become epidemic as a result of the new parenteral transmission routes and are responsible for most HCV infections in Western countries. HCV 1a subtype have been sub-categorized into two separate sub clades. Recent studies based on the analysis of NS5B genome region, reveal that HCV epidemics in Argentina and Brazil are characterized by multiple introductions events of subtypes 1a, 1b and 3a, followed by subsequent local dispersion. There is no data about HCV genotypes circulating in Uruguay and their evolutionary and demographic history. To this end, a total of 153 HCV NS5B gene sequences were obtained from Uruguayan patients between 2005 and 2011. 86 (56%) sequences grouped with subtype 1a, 40 (26%) with subtype 3a and 27 (18%) with subtype 1b. Furthermore, subtype 1a sequences were distributed among both clades, 1 (n=62, 72%) and 2 (n=24, 28%). Four local HCV clades were found: UY-1a(I), UY-1a(II), UY-1a(III) and UY-3a; comprising a 39% of all HCV viruses analyzed in this study. HCV epidemic in Uruguay has been driving by multiple introductions of subtypes 1a, 1b and 3a and by local dissemination of a few country-specific strains. The evolutionary and demographic history of the major Uruguayan HCV clade UY-1a(I) was reconstructed under two different molecular clock rate models and displayed an epidemic history characterized by an initial phase of rapid expansion followed by a more recent reduction of growth rate since 2000-2005. This is the first comprehensive study about the molecular epidemiology and epidemic history of HCV in Uruguay.

Complicaciones graves en la intubación orotraqueal en cuidados intensivos: estudio observacional y análisis de factores de riesgo / Severe complications of orotracheal intubation in the Intensive Care Unit: An observational study and analysis of risk factors

Objetivo Conocer las características de los procedimientos de intubación orotraqueal (IOT) en una Unidad de Medicina Intensiva, describir las complicaciones graves relacionadas con el procedimiento y los factores de riesgo asociados a su aparición. Diseño Estudio prospectivo de cohorte, observacional, durante un periodo de 2 años. Ámbito Unidad de Cuidados Intensivos polivalente de un hospital universitario de segundo nivel. Pacientes Se incluyeron todas las IOT (309 procedimientos) realizadas por el intensivista. Intervenciones Ninguna. Variables de interés principal Datos clínicos previos a la IOT, durante y posintubación, motivo de IOT y sus complicaciones. Análisis de factores de riesgo mediante regresión logística múltiple. Resultados El 76% de las IOT se realizaron de forma inmediata. Se llevaron a cabo mayoritariamente por el médico interno residente de la Unidad de Cuidados Intensivos (60%). El 34% de los procedimientos presentaron complicaciones graves con alteración respiratoria (16%), hemodinámica (5%) o ambas (10%). Fallecieron 3 pacientes (1%) y presentaron parada cardiaca el 2% de los casos. El análisis de regresión logística mostró que la edad (OR 1,1; IC 95%: 1,1-1,2), la tensión arterial sistólica≤90mmHg (OR 3,0; IC 95%: 1,4-6,4) y la SapO2≤90% (OR 4,4; IC 95%: 2,3-8,1) previos a la intubación, la presencia de secreciones (OR 2,2; IC 95%: 1,1-4,6) y la necesidad de más de un intento (OR 3,5; IC 95%: 1,4-8,7) fueron factores independientes para la aparición de complicaciones. Conclusiones La IOT del paciente crítico se asocia a complicaciones respiratorias y hemodinámicas. Los factores de riesgo independientes relacionados con la aparición de complicaciones fueron la edad avanzada, la hipotensión, la hipoxemia previa, las secreciones y la necesidad de más de un intento (AU)

Objective A study is made to determine the characteristics of endotracheal intubation (ETI) procedures performed in an Intensive Care Unit, and to describe the associated severe complications and related risk factors. Design A prospective cohort study involving a 2-year period was carried out. Setting The combined clinical/surgical Intensive Care Unit in a secondary university hospital. Patients All ETIs carried out by intensivists were included. Interventions None. Main variables We analyzed the data associated with the patient, the procedure and the postoperative complications after intubation. The study of risk factors was performed using multiple logistic regression analysis. Results Seventy-six percent of the ETIs were performed immediately. Most of them were carried out by Intensive Care Units residents (60%). A total of 34% of the procedures had severe complications, including respiratory (16%) or hemodynamic (5%) disorders, or both (10%). Three patients died (1%), and 2% of the subjects experienced cardiac arrest. Logistic regression analysis identified the following independent risk factors for complications: age (OR 1.1; 95% CI: 1.1-1.2), systolic blood pressure≤90mmHg (OR 3.0; 95% CI: 1.4-6.4) and SpO2≤90% (OR 4.4; 95% CI: 2.3-8.1) prior to intubation, the presence of secretions (OR 2.2; 95% CI: 1.1-4.6), and the need for more than one ETI attempt (OR 3.5; 95% CI: 1.4-8.7).Conclusions ETI in Intensive Care Unit patients is associated with respiratory and hemodynamic complications. The independent risk factors associated with the development of complications were advanced age, hypotension and previous hypoxemia, the presence of secretions, and the need for more than one ETI attempt (AU)

[Severe complications of orotracheal intubation in the Intensive Care Unit: An observational study and analysis of risk factors]. / Complicaciones graves en la intubación orotraqueal en cuidados intensivos: estudio observacional y análisis de factores de riesgo.

OBJECTIVE: A study is made to determine the characteristics of endotracheal intubation (ETI) procedures performed in an Intensive Care Unit, and to describe the associated severe complications and related risk factors. DESIGN: A prospective cohort study involving a 2-year period was carried out. SETTING: The combined clinical/surgical Intensive Care Unit in a secondary university hospital. PATIENTS: All ETIs carried out by intensivists were included. INTERVENTIONS: None. MAIN VARIABLES: We analyzed the data associated with the patient, the procedure and the postoperative complications after intubation. The study of risk factors was performed using multiple logistic regression analysis. RESULTS: Seventy-six percent of the ETIs were performed immediately. Most of them were carried out by Intensive Care Units residents (60%). A total of 34% of the procedures had severe complications, including respiratory (16%) or hemodynamic (5%) disorders, or both (10%). Three patients died (1%), and 2% of the subjects experienced cardiac arrest. Logistic regression analysis identified the following independent risk factors for complications: age (OR 1.1; 95% CI: 1.1-1.2), systolic blood pressure≤90mmHg (OR 3.0; 95% CI: 1.4-6.4) and SpO2≤90% (OR 4.4; 95% CI: 2.3-8.1) prior to intubation, the presence of secretions (OR 2.2; 95% CI: 1.1-4.6), and the need for more than one ETI attempt (OR 3.5; 95% CI: 1.4-8.7). CONCLUSIONS: ETI in Intensive Care Unit patients is associated with respiratory and hemodynamic complications. The independent risk factors associated with the development of complications were advanced age, hypotension and previous hypoxemia, the presence of secretions, and the need for more than one ETI attempt.

Use of conventional PCR and smear microscopy to diagnose pulmonary tuberculosis in the Amazonian rainforest area

The diagnostic usefulness of Ziehl-Neelsen (ZN)-stained sputum smears combined with conventional polymerase chain reaction (ZN/PCR) to amplify IS6110 region DNA extracted from ZN slides was evaluated. The objective was to verify if this association could improve tuberculosis (TB) diagnosis in patients at remote sites. The study was carried out in 89 patients with culture-confirmed pulmonary TB as defined by the Brazilian Manual for TB Treatment. The participants were recruited in a reference unit for TB treatment in Rondônia, a state in the Amazonian area in northern Brazil. ZN, PCR, and culture performed in the sputum samples from these patients were analyzed in different combinations (i.e., ZN plus PCR and ZN plus culture). The prevalence rates of pulmonary TB in these patients were 32.6 and 28.1% considering culture and ZN/PCR, respectively. The sensitivity and specificity of ZN/PCR were 86 and 93%, respectively. ZN/PCR was able to detect more TB cases than ZN alone. This method could offer a new approach for accurate tuberculosis diagnosis, especially in remote regions of the world where culture is not available.

Use of conventional PCR and smear microscopy to diagnose pulmonary tuberculosis in the Amazonian rainforest area.

The diagnostic usefulness of Ziehl-Neelsen (ZN)-stained sputum smears combined with conventional polymerase chain reaction (ZN/PCR) to amplify IS6110 region DNA extracted from ZN slides was evaluated. The objective was to verify if this association could improve tuberculosis (TB) diagnosis in patients at remote sites. The study was carried out in 89 patients with culture-confirmed pulmonary TB as defined by the Brazilian Manual for TB Treatment. The participants were recruited in a reference unit for TB treatment in Rondônia, a state in the Amazonian area in northern Brazil. ZN, PCR, and culture performed in the sputum samples from these patients were analyzed in different combinations (i.e., ZN plus PCR and ZN plus culture). The prevalence rates of pulmonary TB in these patients were 32.6 and 28.1% considering culture and ZN/PCR, respectively. The sensitivity and specificity of ZN/PCR were 86 and 93%, respectively. ZN/PCR was able to detect more TB cases than ZN alone. This method could offer a new approach for accurate tuberculosis diagnosis, especially in remote regions of the world where culture is not available.

Phylogeography and evolutionary history of rodent-borne hantaviruses.

Hantavirus (Family Bunyaviridae) are mostly associated to rodents and transmitted to man by inhalation of aerosolized infected excreta of these animals. The human infection by hantaviruses can lead to severe diseases such as hemorrhagic fever with renal syndrome (HFRS) in Asia and Europe, and pulmonary syndrome (HPS) in the Americas. To determine the origin, spreading and evolutionary dynamics of rodent-borne hantaviruses, 190 sequences of nucleoprotein (N) of hantaviruses identified in 30 countries, from 1985 to 2010, were retrieved from the GenBank and analyzed using the BEAST program. Our evolutionary analysis indicates that current genetic diversity of N gene of rodent-borne hantaviruses probably was originated around 2000 years ago. Hantavirus harbored by Murinae and Arvicolinae subfamilies, probably, were originated in Asia 500-700 years ago and later spread toward Siberia, Europe, Africa and North America. Hantavirus carried by Neotominae subfamily, probably, emerged 500-600 years ago in Central America and spread toward North America. Finally, hantaviruses associated to Sigmodontinae occurred in Brazil 400 years ago and were, probably, originated from Neotominae-associated virus from northern South America. These data offer subsidies to understand the time-scale and worldwide dissemination dynamics of rodent-borne hantaviruses.

New membranes for extracorporeal blood purification in septic conditions.

Severe sepsis and septic shock are still the leading cause of mortality and morbidity in the intensive care unit. The inflammatory response to infection is associated with an impressive, systemic release of pro- and anti-inflammatory mediators, which results in generalized endothelial damage, multiple organ failure and altered cellular immunological responsiveness. Over the last years, the substantial advances in the understanding of sepsis have led to the development of a large number of new approaches and technologies in the management of septic patients. Extracorporeal blood purification techniques using various membrane materials have been proposed to modulate multiple inflammatory mediators, and seem to be a potential adjuvant in the treatment of sepsis. However, the use of extracorporeal blood purification techniques during sepsis still remains controversial, thus precluding any definitive recommendations on the benefit of these methods. More data are needed to better recognize septic patients who are most likely to benefit from blood purification treatments, and clarify the optimal timing, duration, and number of applications of these techniques in the daily clinical practice.

Expression of vitellogenin receptor gene in the ovary of wild and captive Atlantic bluefin tuna (Thunnus thynnus).

The cDNA sequences of vitellogenin receptor proteins (VgR(+) and VgR(-)), containing or lacking the O-linked sugar domain, were determined in Atlantic bluefin tuna (Thunnus thynnus L.). VgR(-) gene expression in the ovary was compared in captive-reared and wild Atlantic bluefin tuna during the reproductive cycle. Gonad samples from adult fish were sampled from 2008 to 2010 from stocks reared in captivity at different commercial fattening operations in the Mediterranean Sea and from wild individuals caught either by traditional tuna traps during their migration towards the spawning grounds in the Mediterranean Sea or by the long-line artisanal fishery. In addition, juvenile male and female Atlantic bluefin tuna were sampled from a farming facility, to obtain baseline information and pre-adulthood amounts of VgR(-). The total length of VgR(+) cDNA was 4006 nucleotides (nt) and that of VgR(-) was 3946 nt. Relative amounts of VgR(-) were greater in juvenile females and in those adults having only previtellogenic oocytes (119 ± 55 and 146 ± 26 folds more than juvenile males, respectively). Amounts of VgR(-) were less in individuals with yolked oocytes (ripening stage, May-June) and increased after spawning in July (92 ± 20 and 113 ± 13 folds more than juvenile males in ripening and post-spawning fish, respectively). These data suggest that regulation of VgR(-) is not under oestrogen control. During the ripening period, greater VgR(-) gene expression was observed in wild fish than in fish reared in captivity, possibly because of (a) differences in water temperature exposure and/or energy storage, and/or (b) an inadequate diet in reared Atlantic bluefin tuna.

Evidence that severe acute stress and starvation induce rapid atresia of ovarian vitellogenic follicles in Atlantic bluefin tuna, Thunnus thynnus (L.) (Osteichthyes: Scombridae).

The effects of different stressors on the atretic degeneration of ovarian vitellogenic follicles, as well as on the ovarian mass, were examined in female Atlantic bluefin tuna, Thunnus thynnus (L.), from the Mediterranean Sea. The stressors taken into consideration were short-term starvation (up to 14 days), long-term cage rearing (1 year) and crowding-induced severe panic frenzy. Wild-caught individuals were used as a control group. Fish subjected to either severe panic frenzy or starvation exhibited a decrease in gonad mass and had significantly higher intensity of α atresia in the vitellogenic follicles (means: 78% and 58%, respectively; range: 36-100%) than either wild or long-term caged individuals (means: 32% and 30%, respectively; range: 19-44%). The extensive atresia in fish stressed by severe panic frenzy was observed as early as 24 h after the stressing event. The present study represents the first evidence of the extreme susceptibility of Atlantic bluefin tuna to severe acute stress during vitellogenesis; it also shows that starvation is associated with progressive reabsorption of vitellogenic oocytes.

Steroids in severe pneumonia: a literature review.

Despite more than sixty years of scientific medical research, severe pneumonia, either community-acquired or nosocomial, remains a leading cause of death regardless of the patients' immunity state. The clinical introduction of new and more potent antibiotic molecules and the continuous development of efficient respiratory assistance devices may not be able to radically improve the clinical outcome of pneumonia. Adjunctive therapies based on the physiopathological mechanisms of lung damage in severe pneumonia have been strongly advocated, and corticosteroids, which present many properties that theoretically interfere with these pathways, have been widely used, with conflicting results. The aim of this review is to examine existing literature data on steroid use in severe pneumonia. Molecular, endocrinological and clinical studies will be described to help physicians to clarify the reasons for the historical debate about steroid use as an adjunctive treatment in severe pneumonia. There is growing evidence that, during lung infection, an excessive inflammatory response can have deleterious effects and contribute to tissue damage mechanisms. Because of their immunomodulatory properties, glucocorticoids have been suggested as a useful tool for regulating the complex balance of cytokine networks, and they are commonly used as an adjunctive therapy during serious infections. In severe pneumonia, preclinical data, including cytokine level detection and animal studies, have shown encouraging results, although the clinical data is controversial. Moreover, large randomized controlled trials have not been conducted to determine steroid side effects and the risk of immunosuppression-induced superinfections. The benefits of steroid use in patients with severe pneumonia have not been proven by current literature, but ongoing investigations of anti-inflammatory molecules probably represent the key point of severe infection management in the near future.

Making innovations accessible to the poor through implementation research.

Within countries, poorer populations have greater health needs and less access to good medical care than better-off populations. This is particularly true for tuberculosis (TB), the archetypal disease of poverty. Innovations also tend to become available to better-off populations well before they become available to those who need them the most. In a new era of innovations for TB diagnosis and treatment, it is increasingly important not only to be sure that these innovations can work in terms of accuracy and efficacy, but also that they will work, especially for the poor. We argue that after an innovation or a group of innovations has been endorsed, based on demonstrated accuracy and/or efficacy, introduction into routine practice should proceed through implementation by research. Cluster-randomised pragmatic trials are suited to this approach, and permit the prospective collection of evidence needed for full impact assessment according to a previously published framework. The novel approach of linking transmission modelling with operational modelling provides a methodology for expanding and enhancing the range of evidence, and can be used alongside evidence from pragmatic implementation trials. This evidence from routine practice should then be used to ensure that innovations in TB control are used for positive action for all, and particularly the poor.