Surface magnon-polaritons at a dielectric/graphene/gyromagnetic interface in a perpendicular applied magnetic field.

We present a theoretical study of the surface magnon-polaritons at an interface formed by vacuum and a gyromagnetic medium (that can be either ferromagnetic or antiferromagnetic), when there is a graphene layer deposited between the media at the interface and a magnetic field is applied perpendicular to the interface. The retarded-mode dispersion relations are calculated by considering a superposition of transverse magnetic and transversal electric electromagnetic waves in both media. Our results reveal the appearance of the surface magnon-polariton modes (with frequencies typically of a few GHz) that do not exist in the absence of graphene at the interface. Also, a typical magnon-polariton dispersion relation with damping is revealed, including a resonant frequency that depends on the applied magnetic field. The effects of varying the doping levels, which modify the Fermi energies in the graphene, and varying the perpendicular applied magnetic field are presented, revealing a strong influence exerted by the presence of graphene on the surface magnon-polariton modes. Other effects include the control of the slope of the dispersion curves (with respect to the in-plane wave vector) for the modes as the Fermi energies of the graphene sheet are changed and the distinctive localization properties for the emerging surface modes.

Superstatistical and DNA sequence coding of the human genome.

In this work, by considering superstatistics we investigate the short-range correlations (SRCs) and the fluctuations in the distribution of lengths of strings of nucleotides. To this end, a stochastic model provides the distributions of the size of the exons based on the q-Gamma and inverse q-Gamma distributions. Specifically, we define a time series for exon sizes to investigate the SRC and the fluctuations through the superstatistics distributions. To test the model's viability, we use the Project Ensembl database of genes to extract the time evolution of exon sizes, calculated in terms of the number of base pairs (bp) in these biological databases. Our findings show that, depending on the chromosome, both distributions are suitable for describing the length distribution of human DNA for lengths greater than 10 bp. In addition, we used Bayesian statistics to perform a selection model approach, which revealed weak evidence for the inverse q-Gamma distribution for a considerable number of chromosomes.

Magnon-polaritons in graphene/gyromagnetic slab heterostructures.

We present a theoretical study for the surface magnon-polaritons in structures formed by graphene layer(s) on an insulating gyromagnetic medium (that can be either ferromagnetic or antiferromagnetic) surrounded by vacuum. We consider different doping levels to vary the Fermi energies in the graphene, including both semi-infinite and slab magnetic samples. Our results reveal a strong influence, exerted by the presence of graphene, on the surface magnon-polariton modes. The effects include control of the group velocities for the modes as the Fermi energies of the graphene sheet are varied, modified nonreciprocal and reciprocal mode propagation properties depending on the type of magnetic material, and distinct localization properties for the emerging surface modes.

Phononic topological states in 1D quasicrystals.

In this work, we address the study of phonons propagating on a one-dimensional quasiperiodic lattice, where the atoms are considered bounded by springs whose strength are modulated by equivalent Aubry-André hoppings. As an example, from the equations of motion, we obtained the equivalent phonon spectrum of the well known Hofstadter butterfly. We have also obtained extended, critical, and localized regimes in this spectrum. By introducing the equivalent Aubry-André model through the variation of the initial phase [Formula: see text], we have shown that border states for phonons are allowed to exist. These states can be classified as topologically protected states (topological states). By calculating the inverse participation rate, we describe the localization of phonons and verify a phase transition, characterized by the critical value of [Formula: see text], where the states of the system change from extended to localized, precisely like in a metal-insulator phase transition.

Analysis of human DNA through power-law statistics.

We report an analysis of Homo sapiens DNA through the formalism of κ statistics, which encompasses power-law correlations and provides an optimization principle that permits us to model distinct physical systems; i.e., the power-law distribution of the length of DNA bases is calculated from a general model which follows arguments similar to those proposed in Maxwell's deduction of statistical distributions. The viability of the model is tested using a data set from a catalog of proteins collected from the Ensembl Project. The results indicate that the short-range correlations, always present in coding DNA sequences, are appropriately captured through the Kaniadakis power-law distribution, adequately describing the cumulative length distribution of DNA bases, in contrast with the case of the traditional exponential statistical model.

Physical activity and improved diastolic function in spinal cord-injured subjects.

PURPOSE: Subjects with spinal cord injury (SCI) have been reported to present impaired left ventricular (LV) diastolic function in comparison with able-bodied (AB) ones. The present study investigated the effect of regular physical activity on the cardiac structure and function of SCI subjects. METHODS: Fifty-eight SCI men (29 sedentary [SCI-S] and 29 athletes [SCI-A]) and 29 AB men were cross-sectionally evaluated by clinical, laboratory, hemodynamic, and echocardiographic analysis. All enrolled subjects were normotensive, nondiabetic, nonsmoker, and normolipemic, and the studied groups presented similar age and body mass index. RESULTS: SCI-S presented similar LV structural and systolic parameters but higher E/Em (8.0 ± 0.5) and lower Em/Am (1.18 ± 0.09) ratios than SCI-A and AB (E/Em = 6.4 ± 0.3 and 5.9 ± 0.3, respectively; Em/Am = 1.57 ± 0.12 and 1.63 ± 0.08, respectively; all P < 0.05 compared with SCI-S). Analysis of SCI individuals according to injury level revealed that tetraplegic athletes had similar features compared with sedentary tetraplegic subjects, except for higher Em (10.9 ± 0.6 vs 8.6 ± 0.7 cm s, P < 0.05) and lower E/Em ratio (6.3 ± 0.4 vs 8.8 ± 0.8, P < 0.05), whereas paraplegic athletes had similar features compared with sedentary paraplegic individuals, except for higher LV end-diastolic diameter (49.4 ± 1.4 vs 45.0 ± 1.0 mm, P < 0.05) and Em/Am ratio (1.69 ± 0.20 vs 1.19 ± 0.08, P < 0.05) and lower LV relative wall thickness (0.330 ± 0.012 vs 0.369 ± 0.010, P < 0.05) and heart rate (67.1 ± 4.2 vs 81.9 ± 2.8 bpm, P < 0.05). CONCLUSION: Regular physical activity is associated with improved LV diastolic function in SCI subjects and might exert distinct cardiac structural effects in tetraplegic and paraplegic subjects.

Avaliação da qualidade microbiológica e parasitológica de alimentos servidos às crianças de escolas do ensino infantil de um município da região de São José do Rio Preto - SP

Todos os anos, milhões de pessoas no mundo são hospitalizadas ou morrem devido às doenças de origem alimentar, que de acordo com os dados do Ministério da Saúde de 2000 a 2013 foram notificados 8.746 surtos de Doenças Transmitidas por Alimentos, resultando em 112 óbitos no Brasil, que são resultados da contaminação por micro-organismos, produtores de toxinas ou patogênicos, e, ou parasitas. Segundo dados da Secretaria de Vigilância em Saúde (SVS) as escolas ocupam o terceiro lugar em ocorrências de surtos.

Avaliação da higiene de pratos e colheres utilizados por alunos de escolas do ensino infantil e fundamental de uma cidade da região de São José do Rio Preto SP

Em ambientes de alimentação, um dos fatores que podem estar relacionados com as Doenças Transmitidas por Alimentos (DTA), são os utensílios contaminados com micro-organismos, principalmente devido a sua higiene ou armazenamento inadequado. Os manipuladores de alimentos são peças fundamentais na segurança alimentar e podem contribuir na transmissão de patógenos se a higienização dos utensílios utilizados em refeições for inadequada, no entanto, a educação dos manipuladores é fundamental na prevenção da maioria dos tipos de DTA, visto que estes surtos ocupam o terceiro lugar de ocorrências nas escolas, de acordo com os dados da Secretaria de Vigilância em Saúde (SVS).

Changes in the blood parameters of the Amazonian manatee (Trichechus inunguis) after long-distance transportation - doi: 10.4025/actascibiolsci.v35i4.20081

In this study we report the hematological, biochemical and hormonal parameters in a juvenile male Amazonian manatee measured before transport, immediately after transport, and during adaptation to a new facility. The animal was transported from Manaus, Amazonas, Brazil, to São Paulo, São Paulo, Brazil, (2,733 km) within 6 hours. Among all blood parameters analyzed, we observed obvious neutrophilia, lymphopenia, and increases in the neutrophil/lymphocyte ratio and serum glucose and aspartate aminotransferase (AST) levels, but these parameters subsequently returned to normal. These results suggest that transport and changes in the environment are temporary stressful events for Amazonian manatees. We, therefore, recommend monitoring the hematological and biochemical parameters before and after translocation to minimize the effects of handling stressors in this species

P-selectin knockout mice have improved outcomes with both warm ischemia and small bowel transplantation.

AIM: To analyze the role of P-selectin in intestinal ischemia and reperfusion injury (IRI) using murine models. METHODS: A model of warm IRI wherein the SMA was occluded for 100 minutes was undertaken in the following groups (10 mice per group): Group 1 (control) wild-type (WT) C57BL6, no treatment; Group 2: 0.4 mg/kg of r-PSGL1-lg 10 minutes before and after clamping; Group 3: PSGL KO mice. Survival was assessed at 7 days; the intestine was assayed for histopathology, apoptosis, myeloperoxidase (MPO), IL1, and TNF. A second model of cold IRI followed by intestinal transplantation (IT) was undertaken in the following groups (two mice per group): Group A WT --> WT: Group B PSGL KO --> WT (1-hour ischemia); Group C: PSGL KO --> WT (2 hour ischemia). Survival only was assessed. RESULTS: Survival was 50% in group 1, 90% in group 2, and 100% in group 3. Graded histopathology and crypt apoptosis demonstrated significantly less injury in groups B and C. MPO was not different between groups. IL1 and TNF were significantly reduce in groups 2 and 3. Following IT, survival was <12 hours in group A, >7 days in group B, and <72 hours in group C. CONCLUSION: This study clearly demonstrates the importance of P-selectin in warm and cold IRI in that the blockade of P-selectin using rPSGL1-lg or the absence of P-selectin using KO mice confers a survival advantage and reduction in tissue injury. The mechanism is unclear but appears to be independent of neutrophil infiltration.

Heavy chain ferritin acts as an antiapoptotic gene that protects livers from ischemia reperfusion injury.

Heme oxygenase-1 (HO-1) is induced under a variety of pro-oxidant conditions such as those associated with ischemia-reperfusion injury (IRI) of transplanted organs. HO-1 cleaves the heme porphyrin ring releasing Fe2+, which induces the expression of the Fe2+ sequestering protein ferritin. By limiting the ability of Fe2+ to participate in the generation of free radicals through the Fenton reaction, ferritin acts as an anti-oxidant. We have previously shown that HO-1 protects transplanted organs from IRI. We have linked this protective effect with the anti-apoptotic action of HO-1. Whether the iron-binding properties of ferritin contributed to the protective effect of HO-1 was not clear. We now report that recombinant adenovirus mediated overexpression of the ferritin heavy chain (H-ferritin) gene protects rat livers from IRI and prevents hepatocellular damage upon transplantation into syngeneic recipients. The protective effect of H-ferritin is associated with the inhibition of endothelial cell and hepatocyte apoptosis in vivo. H-ferritin protects cultured endothelial cells from apoptosis induced by a variety of stimuli. These findings unveil the anti-apoptotic function of H-ferritin and suggest that H-ferritin can be used in a therapeutic manner to prevent liver IRI and thus maximize the organ donor pool used for transplantation.

Liver transplantation at Dumont-UCLA Transplant Center: an experience with over 3,000 cases.

Liver transplantation has seen extraordinary advances over the past 2 decades and now represents the only life-saving therapy for many patients with decompensated liver disease, regardless of etiology. As the indications for transplantation expand, the patient waiting list continues to grow, while the number of available donors each year remains relatively constant. As a result, there is a marked shortage of donor organs, prolonging the waiting time and thereby increasing the mortality of patients while waiting for OLT. At UCLA, we are actively pursuing novel approaches to increase retrieval of transplant organs. The use of in-vivo split-liver transplantation represents an effective technique to safely expand the number of organs and also provides a size-matched organ for pediatric patients. Living-donor liver transplantation represents a significant surgical achievement in an effort to expand the critical shortage of donor organs. However, the added risk imposed on a healthy individual by the use of this technique raises serious bio-ethical concerns. Although the results of OLT have improved substantially, most of the current recipient morbidity and mortality results from recurrence of disease, infectious complications, rejection, PNF, and technical complications. The development of effective pharmacological agents to prevent disease recurrence, as well as improvements in immunosuppression therapy will be important issues in the upcoming decade.

In vitro reconstitution of a functional duck hepatitis B virus reverse transcriptase: posttranslational activation by Hsp90.

Reverse transcription in hepatitis B viruses is initiated through a unique protein priming mechanism whereby the viral reverse transcriptase (RT) first assembles into a ribonucleoprotein (RNP) complex with its RNA template and then initiates DNA synthesis de novo using the RT itself as a protein primer. RNP formation and protein priming require the assistance of host cell factors, including the molecular chaperone heat shock protein 90 (Hsp90). To better understand the mechanism of RT activation by Hsp90, we have now mapped the minimal RT sequences of the duck hepatitis B virus that are required for chaperone binding, RNP formation, and protein priming. Furthermore, we have reconstituted in vitro both RNP formation and protein priming using purified RT proteins and host factors. Our results show that (i) Hsp90 recognizes two independent domains of the RT, both of which are necessary for RNP formation and protein priming; (ii) Hsp90 function is required not only to establish, but also to maintain, the RT in a state competent for RNA binding; and (iii) Hsp90 is not required during RT synthesis and can activate the RT posttranslationally. Based on these findings, we propose a model for Hsp90 function whereby the chaperone acts as an active interdomain bridge to bring the two RT domains into a poised but labile conformation competent for RNP formation. It is anticipated that the reconstitution system established here will facilitate the isolation of additional host factors required for RT functions and further elucidation of the mechanisms of RT activation.

The Cool Kids Coalition.

The Cool Kids Coalition was initiated as a community response to more than 214 hospitalizations of children under the age of five for burns over a 6-year period in one township in Long Island, NY. The coalition was started by public health nurses in partnership with the local chapter of the National Safe Kids Campaign. Goals included: 1. parent education regarding scald burn prevention; 2. development of innovative interventions for those at risk; and 3, development of innovative community approaches to scald prevention. Coalition members had diverse backgrounds and the coalition integrated non-traditional partners in injury control. The coalition doubled in size due to overwhelming community interest, growing within a few months from an initial group of 15 to a well-represented group of 30. Innovative programs were implemented that reached more than 3,000 parents, both in the community and home. Teaching was conducted with parents in the target population in Head Start centers, homeless shelters, the home, libraries, child care centers, a shelter for teen parents, etc. Member agencies incorporated the booklet and materials into their individual programs. The development of the Cool Kids Coalition illustrates the power of nursing in community health.

A program to educate woman who test positive for the hepatitis B virus during the perinatal period.

This computerized patient education program targeted the woman's self-identified learning needs and educated her about etiology, prognosis, and risk of transmission to the infant and other contacts. The educational program is an 18-page color slide presentation intended to be viewed jointly by the nurse and patient during a home visit. It uses strategies known to be effective for women with low literacy skills; the nurse uses this as an adjunct teaching tool to traditional one-on-one verbal instruction. Because many women who test positive for hepatitis B surface antigen during the perinatal period lack basic knowledge regarding the hepatitis B virus, it is essential that nurses teach this important information to at-risk populations.

Reduction of hepatic ischemia/reperfusion injury by a soluble P-selectin glycoprotein ligand-1.

OBJECTIVE: The authors' goal was to determine the effects of specific binding and blockade of P- and E-selectins by a soluble P-selectin glycoprotein ligand-1 (PSGL-1) in rat models of hepatic in vivo warm ischemia and ex vivo cold ischemia. The authors also sought to determine the effect of selectin blockade on isograft survival in a syngeneic rat orthotopic liver transplant model. SUMMARY BACKGROUND DATA: Ischemia/reperfusion (I/R) injury is a major factor in poor graft function after liver transplantation, which may profoundly influence early graft function and late changes. It is hypothesized that I/R injury leads to the upregulation of P-selectin, which is then rapidly translocated to endothelial cell surfaces within 5 minutes of reperfusion of the liver, initiating steps leading to tethering of polymorphonuclear neutrophil leukocytes to the vascular intima. Local production by leukocytes of interleukin-1, tumor necrosis factor-alpha, or both induces P-selectin expression on the endothelium and continues the cascade of events, which increases cell adherence and infiltration of the organ. METHODS: To examine directly the effects of selectins in a warm hepatic I/R injury model, 100 microg of PSGL-1 or saline was given through the portal vein at the time of total hepatic inflow occlusion. The effects of PSGL-1 in cold ischemia were assessed using an isolated perfused rat liver after 6 hours of 4 degrees C storage in University of Wisconsin (UW) solution, with or without the instillation of PSGL-1 before the storage. To evaluate the effect of selectin blockade on liver transplant survival, syngeneic orthotopic liver transplants were performed between inbred male Sprague-Dawley rats after 24 hours of cold ischemic storage in UW solution. A separate group of animals received two doses of 100 microg of PSGL-1 through the portal vein before storage and before reperfusion of the transplanted liver. Recipient survival was assessed at 7 days, and the Kaplan-Meier product limit estimate method was used for univariate calculations of time-dependent recipient survival events. RESULTS: In an in vivo warm rat liver ischemia model, perfusion with PSGL-1 afforded considerable protection from I/R injury, as demonstrated by decreased transaminase release, reduced histologic hepatocyte damage, and suppressed neutrophil infiltration, versus controls (p < 0.05). When cold stored livers were reperfused, PSGL-1 reduced the degree of hepatocyte transaminase release, reduced neutrophil infiltration, and decreased histologic hepatocyte damage (p < 0.05 vs. UW-only controls). On reperfusion, livers treated with PSGL-1 demonstrated increased portal vein blood flow and bile production (p < 0.05 vs. UW-only controls). In addition, 90% of the rats receiving liver isografts stored in UW solution supplemented with PSGL-1 survived 7 days versus 50% of those whose transplanted syngeneic livers had been stored in UW alone (p < 0.05). CONCLUSIONS: Selectins play an important role in I/R injury of the liver. Early modulation of the interaction between P-selectin and its ligand decreases hepatocyte injury, neutrophil adhesion, and subsequent migration in both warm and cold rat liver ischemia models. In addition, the use of PSGL-1 before ischemic storage and before transplantation prevents hepatic injury, as documented by a significant increase in liver isograft survival. These findings have important clinical ramifications: early inhibition of alloantigen-independent mechanisms during the I/R damage may influence both short- and long-term survival of liver allografts.

Nalbuphine's reversal of hypovolemic shock in the anesthetized rat.

Nalbuphine is an agonist-antagonist analgesic chemically related to the opiate agonist oxymorphone and to the opiate antagonist naloxone. Because naloxone has been shown to be beneficial in hemorrhagic shock, this study was undertaken to investigate the hemodynamic effects of nalbuphine in anesthetized rats. The animals were bled 1% of body weight, which caused a significant decrease in mean arterial pressure (MAP) and heart rate (HR). Results indicate an immediate increase in MAP and HR above posthemorrhage values in the rats treated with 1 and 5 mg/kg nalbuphine compared with no improvement for the rats in the saline-treated group. The increases in MAP were sustained for periods up to 120 min postadministration of nalbuphine. Measurements of cardiac output and regional distribution of blood flow indicate that nalbuphine caused an increase in cardiac output, heart rate, stroke volume, and dP/dt with no change in total peripheral resistance.