Respiratory virus detection among healthcare professionals in Brazil: work-related contact and episode recurrence during the COVID-19 pandemic.

OBJECTIVES: Since the beginning of the COVID-19 pandemic, changes in the circulation of respiratory viruses have been observed after measures to control the spread of SARS-CoV-2 were implemented. In this sense, we aimed to understand the circulation of the respiratory virus and its impact in a controlled healthy population of healthcare professional (HCP) volunteers in phase III of the clinical trial of the ChadOx nCoV1 conducted in São Paulo, Brazil. STUDY DESIGN: This was a nested observational cohort study within a clinical trial. METHODS: We performed RT-qPCR to detect SARS-CoV-2, influenza virus A and B (IVA and IVB), respiratory syncytial virus (RSV), human rhinovirus (HRV), human metapneumovirus (hMPV), human coronaviruses (hCoVs: HKU-1, NL63, OC43, and 229-E), parainfluenza virus (PiV) I-IV, and q-PCR for adenovirus in nasopharyngeal and oropharyngeal samples obtained from HCP enrolled in the clinical trial to assess respiratory viruses infection among vaccinated and non-vaccinated. RESULTS: From July 2020 to January 2022, 876 samples were included from 737 volunteers (median age: 33 years, 62.9% female). New episodes were registered for 119 individuals. We observed an overall positivity of 37.7% for SARS-CoV-2 and 16.4% for other respiratory viruses; HRV was the second most detected virus (8%), followed by RSV (2.4%). Fully vaccinated individuals accounted for 53.3% of collected samples, and 52.9% presented at least one respiratory virus infection, with SARS-CoV-2 being the most predominant etiologic agent (62.3%). Influenza and hMPV were not detected among the tested samples. Among the subjects that presented more than one episode, SARS-CoV-2 and HRV infections were related to direct contact with patients (P < 0.002). CONCLUSIONS: Data show high infection rates among HCPs even under mask policies and contact precautions, highlighting the need for improvement in infection control measures in this population regardless of the vaccination program.

Distinctive g-Factor of Moiré-Confined Excitons in van der Waals Heterostructures.

We investigated the valley Zeeman splitting of excitonic peaks in the microphotoluminescence (µPL) spectra of high-quality hBN/WS2/MoSe2/hBN heterostructures under perpendicular magnetic fields up to 20 T. We identify two neutral exciton peaks in the µPL spectra; the lower-energy peak exhibits a reduced g-factor relative to that of the higher energy peak and much lower than the recently reported values for interlayer excitons in other van der Waals (vdW) heterostructures. We provide evidence that such a discernible g-factor stems from the spatial confinement of the exciton in the potential landscape created by the moiré pattern due to lattice mismatch or interlayer twist in heterobilayers. This renders magneto-µPL an important tool to reach a deeper understanding of the effect of moiré patterns on excitonic confinement in vdW heterostructures.

In vitro digestibility of four high moisture grains used in liquid pig feeding.

One of the main challenges in the livestock sector is the need to increase sustainability and production efficiency. In pig production, feed is the main production cost. High moisture grains (HMGs) have recently emerged as an interesting alternative to conventional feedstuffs. In this study, the nutritional value for pigs of eight HMGs was determined considering the chemical composition and the in vitro digestibility. We have used four seeds (lupine, barley, wheat, and corn) and two substrates (water and whey). Lupine HMG showed higher values of crude fat (2.12%) and crude protein (8.59%). Within cereal HMGs, corn HMG showed higher DM (34.37%), OM (36.27%), and starch (27.17%) values; wheat HMG stood out for crude protein content (4.23%) and barley for NDF (5.68%). The pH values were low for all HMG, with lupine having the highest value (4.39). Ammoniacal nitrogen had the highest value for wheat HMG (6.10%). When whey was used as substrate, it improved the characteristics of the HMG. Regarding in vitro digestibility, of the four HMGs studied, wheat showed the highest value for DM (89.93%), while lupine showed the highest value for crude protein (96.12%). When considering the substrates, whey showed better results for all in vitro digestibility's parameters (87.48%, 90.95%, and 90.59%, for DM, OM, and crude protein, respectively). Overall, all HMGs showed good conservation of nutritional value and high in vitro digestibility. The use of whey as a substrate was beneficial for HMG quality. Results show that the analyzed HMG can be efficiently used in the framework of swine production.

Zitterbewegung of Moiré Excitons in Twisted MoS_{2}/WSe_{2} Heterobilayers.

The moiré pattern observed in stacked noncommensurate crystal lattices, such as heterobilayers of transition metal dichalcogenides, produces a periodic modulation of their band gap. Excitons subjected to this potential landscape exhibit a band structure that gives rise to a quasiparticle dubbed the moiré exciton. In the case of MoS_{2}/WSe_{2} heterobilayers, the moiré trapping potential has honeycomb symmetry and, consequently, the moiré exciton band structure is the same as that of a Dirac-Weyl fermion, whose mass can be further tuned down to zero with a perpendicularly applied field. Here we show that, analogously to other Dirac-like particles, the moiré exciton exhibits a trembling motion, also known as Zitterbewegung, whose long timescales are compatible with current experimental techniques for exciton dynamics. This promotes the study of the dynamics of moiré excitons in van der Waals heterostructures as an advantageous solid-state platform to probe Zitterbewegung, broadly tunable by gating and interlayer twist angle.

Influence of feeding supplements of almond hulls and ensiled citrus pulp on the milk production, milk composition, and methane emissions of dairy cows.

Almond hulls and citrus pulp have been fed to dairy cows with variable responses for milk production, but no information exists on their effect on enteric methane emissions. This experiment examined the effects of dietary supplementation with either almond hulls or ensiled citrus pulp on the milk yield, milk composition, and enteric methane emissions of dairy cows. Thirty-two Holstein dairy cows in mid lactation were offered 1 of 3 diets over a 28-d experiment. Twelve cows received a control (CON) diet, 10 cows a diet containing almond hulls (ALH), and 10 cows a diet containing ensiled citrus pulp (CIT). All cows were offered 6.0 kg of dry matter (DM)/d of crushed corn, 2.0 kg of DM/d of cold-pressed canola, and 0.2 kg of DM/d of a mineral mix. In addition, cows fed the CON diet were offered 14.5 kg of DM/d of alfalfa cubes; cows fed the ALH diet were offered 10.5 kg of DM/d of alfalfa cubes and 4.0 kg of DM/d of almond hulls; and cows on the CIT diet were offered 11.5 kg of DM/d of alfalfa cubes and 3.0 kg of DM/d of ensiled citrus pulp. Milk yield was measured daily and milk composition was measured on 4 d of each week. Individual cow methane emissions were measured by a sulfur hexafluoride tracer technique on d 24 to 28 of the experiment. The mean milk yield of cows fed the CON diet (27.4 kg/d) was greater than the mean milk yield of cows fed the ALH diet (24.6 kg/cow per day), whereas the mean milk yield of cows fed the CIT diet (26.2 kg/cow per day) was not different from the mean milk yield from cows fed the other 2 diets. Dietary treatment did not influence the concentrations of milk fat, protein, and lactose or fat yields, but the mean protein yield from cows fed the CON diet (0.87 kg/d) was greater than that from cows fed the ALH diet (0.78 kg/d) but not different to those fed the CIT diet (0.85 kg/d). In general, we found no differences in the proportion of individual fatty acids in milk. The mean pH of ruminal fluid from cows offered the CON diet was not different to the pH in the ruminal fluids of cows offered the ALH or the CIT diets. The mean methane emissions (g/d) and yields (g/kg of DM intake) were not influenced by dietary treatment. These findings indicate that, although almond hulls and ensiled citrus pulp can be used as a low-cost feed supplement, almond hulls did negatively affect milk production and neither inhibited enteric methane emissions.

BACTERIAL COMMUNITY DYNAMICS AND ECOTOXICOLOGICAL ASSESSMENT DURING BIOREMEDIATION OF SOILS CONTAMINATED BY BIODIESEL AND DIESEL/BIODIESEL BLENDS.

The gradual introduction of biodiesel in the Brazilian energy landscape has primarily occurred through its blending with conventional petroleum diesel (e.g., B20 (20% biodiesel) and B5 (5% biodiesel) formulations). Because B20 and lower-level blends generally do not require engine modifications, their use as transportation fuel is increasing in the Brazilian distribution networks. However, the environmental fate of low-level biodiesel blends and pure biodiesel (B100) is poorly understood and the ecotoxicological-safety endpoints of biodiesel-contaminated environments are unknown. Using laboratory microcosms consisting of closed reactor columns filled with clay loam soil contaminated with pure biodiesel (EXPB100) and a low-level blend (EXPB5) (10% w/v), this study presents soil ecotoxicity assessement and dynamics of culturable heterotrophic bacteria. Most-probable-number (MPN) procedures for enumeration of bacteria, dehydrogenase assays and soil ecotoxicological tests using Eisenia fetida have been performed at different column depths over the course of incubation. After 60 days of incubation, the ecotoxicity of EXPB100-derived samples showed a decrease from 63% of mortality to 0% while EXPB5-derived samples exhibited a reduction from 100% to 53% and 90% on the top and at the bottom of the reactor column, respectively. The dehydrogenase activity of samples from EXPB100 and EXPB5 increased significantly compared to pristine soil after 60 days of incubation. Growth of aerobic bacterial biomass was only observed on the top of the reactor column while the anaerobic bacteria exhibited significant growth at different column depths in EXPB100 and EXPB5. These preliminary results suggest the involvement of soil indigenous microbiota in the biodegradation of biodiesel and blends. However, GC-FID analyses for quantification of fatty acid methyl esters (FAMEs) and aliphatic hydrocarbons and targeted sequencing of 16S rRNA tags using illumina platforms will provide important insights into the profiles and underlying mechanisms of (bio)diesel biodegradation in soil environments.

Production, Nutritional Quality and In vitro Methane Production from Andropogon gayanus Grass Harvested at Different Maturities and Preserved as Hay or Silage.

Andropogon gayanus is an important grass due to its high biomass production, drought tolerance and favorable growth on low fertility acidic soils. Currently, there is little research on the impact of growth stage on the nutritional quality or the degree of CH4 production that may arise from this forage during ruminal fermentation. The objectives of this study were to determine the effects of regrowth stage of A. gayanus on its chemical composition, in vitro production of gas and CH4, as well as in vitro dry matter (DM) digestibility when grown under tropical Brazilian conditions and conserved as hay or as silage. The nutritional value of A. gayanus grass declined with increasing maturity; however digestible DM yield linearly increased. After 112 d of regrowth, A. gayanus produced higher quality silage (higher lactate and lower pH and butyrate content) and higher DM yield. However, the low levels of crude protein at this time would make protein supplementation a necessity for proper rumen fermentation. No differences in CH4 kinetic parameters were found with advancing maturity or preservation method (hay or silage).

Identification of phenotypic markers of B cells from patients with Chagas disease.

Chagas disease was discovered more than a hundred years ago, but its pathogenesis is still not completely understood. Autoimmunity is one of the mechanisms shown to contribute to its pathogenesis, which may indicate an important participation of B lymphocytes. Patients with Chagas disease have shown increased percentage of B cells producing IL-10. However, there are no reports of the phenotypic markers of B cells producing IL-10 in patients with Chagas disease. For the first time in the literature, we evaluated the phenotypic profile of distinct markers of B cells from peripheral blood of noninfected individuals and patients with Chagas disease. Our results showed that patients with Chagas disease had a higher expression of CD21 and CD24 on the surface of CD19+ B cells, while CD43 and CD23 were expressed equally in all groups. Moreover, the expression of MHC-II (HLA-DR), CD80, CD86, caspase-3, granzyme B and intracellular IL-10 and TGF-ß by CD19+ B cells was higher in patients with Chagas disease. The results of IL-10 production within CD19+ CD5+ CD1d+ B cells showed a higher percentage of this cytokine in patients with Chagas disease. Thus, our data bring a new knowledge about distinct markers of B cells in immune responses of Chagas disease.

Identification of Waitea circinata as a Pathogen of the Moss Bryum argenteum var. argenteum on a Golf Course Fairway.

Waitea circinata Warcup and Talbot (also referred to as W. circinata var. circinata) is an important fungal pathogen of amenity turfgrasses and is especially problematic on Poa annua in putting greens in the late spring or early summer. The pathogen was first identified in 2005 from Japan and has since been seen widely throughout the United States (1,2). On occasion, the pathogen has been observed attacking creeping bentgrass (Agrostis stolonifera) but is typically less virulent. Disease symptoms include prominent yellow rings appearing throughout established turf and moderate leaf necrosis. In the summer of 2012, moss from a section of fairway on a golf course in Edwards, CO was observed to be rapidly killed by a fungal pathogen producing copious amounts of aerial mycelium and appearing similar to Waitea microscopically. Aerial mycelium was transferred to acidified potato dextrose agar (PDA) (1 ml lactic/L). After 1 day at 25°C, mycelia were transferred to PDA. After 2 weeks, plates were covered with white aerial mycelium and separate, spherical, 0.5-mm diameter, salmon-colored sclerotia, which turned dark brown within a few days and were produced submerged throughout the media. Spores were never produced and right-angled branching of mycelia, characteristic of Waitea, was observed in mature cultures. Mycelial plugs were incubated in nutrient broth and DNA was extracted using a MoBio Power Plant DNA extraction kit. Amplification of ribosomal ITS sequences with ITS4 and ITS5 resulted in a 100% identity match with GenBank sequence HM807352, W. circinata var. circinta (3). To demonstrate pathogenicity on Bryum argenteum, unaffected moss from the submitted sample (identified as B. argenteum var. argenteum via 100% sequence identity with the published GenBank sequence GU907062) was removed from the originally submitted sample and placed in separate growth chambers at 95% humidity and 21, 26, and 31°C. An additional experiment employed local B. agenteum plants collected from the URI Kingston, RI campus. Agar plugs from the isolated W. circinata were placed on top of the moss and within 2 days the fungus had caused complete mortality at all three temperatures. The experiment was also undertaken using the same environmental conditions with 5-week-old annual bluegrass (P. annua) and creeping bentgrass cv. A4 grown from seed. Plants were inoculated with infected rye grains at 31, 26, and 21°C. After 1 week, the P. annua plants showed significant mortality at 26 and 31°C with little infection at 21°C and the A. stolonifera plants showed moderate mortality at 26°C and little infection at the other two temperatures. All experiments utilized an additional uninoculated control treatment that showed no moss/turf necrosis or mortality. Experiments were all repeated once and used three replicates per experiment. While moss is not intentionally cultivated on golf courses, it does occur with regularity and often presents itself as a difficult pest to manage. This particular isolate of W. circinata has identical ribosomal and physiological characteristics of the reported P. annua pathogen but can attack one moss species and may be a possible candidate for selective biological control of moss in golf course settings. It is unclear how widespread moss pathogenicity is within W. circinata. References: (1) E. N. Njambere et al. Plant Dis. 95:78 2011. (2) T. Toda et al. Plant Dis. 89:536, 2005. (3) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications, 1990.

In vitro Fermentation, Digestion Kinetics and Methane Production of Oilseed Press Cakes from Biodiesel Production.

Following the extraction of oil for biodiesel production, oilseed press cakes are high in fat. As the dietary supplementation of fat is currently considered the most promising strategy of consistently depressing methanogenesis, it follows that oilseed press cakes may have a similar potential for CH4 abatement. As such, this study aimed to characterise the nutritive value of several oilseed press cakes, glycerine and soybean meal (SBM) and to examine their effects on in vitro ruminal fermentation, digestion kinetics and CH4 production. Moringa press oil seeds exhibited the greatest in sacco effective degradability (ED) of DM and CP (p<0.05). In vitro gas production (ml/g digested DM) was not affected (p = 0.70) by supplement at 48 h of incubation. In vitro DMD was increased with the supplementation of glycerine and SBM at all levels of inclusion. Moringa oilseed press cakes produced the lowest CH4 (mg/g digested DM) at 6 and 12 h of incubation (p<0.05). The findings suggest that moringa oilseed press cake at 400 g/kg DM has the greatest potential of the oilseed press cakes examined in this study, to reduce CH4 production, without adversely affecting nutrient degradability.

Prevalence of dystrophic epidermolysis bullosa in Spain: a population-based study using the 3-source capture-recapture method. Evidence of a need for improvement in care.

BACKGROUND: Dystrophic epidermolysis bullosa (DEB) is a rare disease that represents a heavy burden for both the patient and the health care system. There are currently no data on the prevalence of DEB in Spain. OBJECTIVE: To determine the prevalence of DEB in Spain. METHODS: We used data from 3 incomplete population-based sources (hospital dermatology departments, diagnostic laboratories performing antigenic mapping, genetic testing or both, and the Spanish Association of Epidermolysis Bullosa Patients [DEBRA]) and combined them using the 3-source capture-recapture methodology. RESULTS: We identified 152 living DEB patients. The estimated prevalence of DEB was 6.0 cases per million (95% CI, 4.2-11.8) in adults and 15.3 (95% CI, 10.4-40.8) in children under 18 years of age. The data indicated that 77% of the patients were not being followed up in specialized centers of reference; 65% had not had a genetic diagnosis, and 76% were not members of DEBRA. CONCLUSIONS: The prevalence of DEB in Spain is 6.0 patients per million (95% CI, 4.2-11.8), a figure higher than previous estimates in many areas, but similar to those found in other southern Europe countries. The north-south difference may represent real geographic differences in prevalence, but it might be due to the fact that most of the data come from registries with a lower than expected catchment. Many patients are not being followed up in centers of reference, do not have genetic diagnosis, and are not members of patients' associations, suggesting that there is room for considerable improvement in their care.

Factors that Influence Placement of Gastrostomy Tube in Infants with Complex Congenital Heart Disease: A Single Center Study.

BACKGROUND: Factors that determine the need for Gastrostomy tube (G-tube) placement in infants with complex congenital heart defects (CHD) are variable. We aim to identify factors that improve counseling of expectant parents regarding postnatal outcomes and management. METHODS: We performed a retrospective review of medical record of infants with prenatal diagnoses of complex CHD between 2015-2019 in a single tertiary care center and assessed risk factors for G-tube placement with linear regression. RESULTS: Of the 105 eligible infants with complex CHD, 44 infants required G-tube (42%). No significant association was observed between G-tube placement and chromosomal abnormalities, cardiopulmonary bypass time or type of CHD. Median days on noninvasive ventilation (4 [IQR 2-12] vs. 3 [IQR 1-8], p = 0.035), time at which gavage-tube feeds were started postoperatively (3 [IQR 2-8] vs. 2 [IQR 0-4], p = 0.0013), time to reach full-volume gavage-tube feeds (6 [IQR 3-14] vs. 5 [IQR 0-8], p = 0.038) and intensive care unit (ICU) length of stay (LOS) (41 [IQR: 21 - 90] vs. 18 [IQR: 7 - 23], p < 0.01) were associated with G-tube placement. Infants with ICU LOS duration longer than median had almost 7 times the odds of requiring a G-tube (OR: 7.23, 95% CI: 2.71-19.32; by regression). CONCLUSIONS: Delay in initiation and in reaching full-volume gavage-tube feeds after cardiac surgery, increased number of days spent on non-invasive ventilation and in the ICU were found to be significant predictors for G-tube placement. The type of CHD and the need for cardiac surgery were not significant predictors for G-tube placement.

Characterization of CD4⁺ cytotoxic lymphocytes and apoptosis markers induced by Trypanossoma cruzi infection.

Although the pathophysiology of Chagas disease is not completely understood, it is widely accepted that involvement of the immune response is critical in determining the outcome of the disease. In this context, CD4⁺ T cells may play an important role in generating different mechanisms of protection. In addition to effector and regulatory functions, CD4⁺ T cells may be also involved with lytic activities against the parasite and may have a relevant role on control of the infection. In this study, we have evaluated CD4⁺ T cells expressing cytotoxic and apoptosis markers in response to Trypanossoma cruzi infection in indeterminate (IND) and cardiac (CARD) patients with Chagas disease and non-infected individuals (NI). Our data demonstrated that: (1) CD4⁺ T cells presented higher ex vivo granzyme B expression in patients with Chagas disease compared with healthy individuals and that antigen induced a greater granzyme B expression in IND patients; (2) CD95L expression in CD4⁺ CD95⁺ T cells from IND patients is higher than in CARD and NI; (3) IND and CARD patients had an increased frequency of caspase-3 after in vitro stimulation and also expressed a high frequency of annexinV⁺ 7ADD⁺ within CD4⁺ T cells; (4) Lastly, a positive correlation was seen between cytotoxic molecules and CD45RO memory marker in CD4⁺ T cells and between caspase-3 and CD95L within CD4⁺ CD95⁺ T cells. These results suggest new insights into the functional competence of CD4⁺ T cells among the different clinical forms of Chagas disease, which will lead to a better understanding of their influence during immune responses against T. cruzi.

Methane Production of Different Forages in In vitro Ruminal Fermentation.

An in vitro rumen batch culture study was completed to compare effects of common grasses, leguminous shrubs and non-leguminous shrubs used for livestock grazing in Australia and Ghana on CH4 production and fermentation characteristics. Grass species included Andropodon gayanus, Brachiaria ruziziensis and Pennisetum purpureum. Leguminous shrub species included Cajanus cajan, Cratylia argentea, Gliricidia sepium, Leucaena leucocephala and Stylosanthes guianensis and non-leguminous shrub species included Annona senegalensis, Moringa oleifera, Securinega virosa and Vitellaria paradoxa. Leaves were harvested, dried at 55°C and ground through a 1 mm screen. Serum bottles containing 500 mg of forage, modified McDougall's buffer and rumen fluid were incubated under anaerobic conditions at 39°C for 24 h. Samples of each forage type were removed after 0, 2, 6, 12 and 24 h of incubation for determination of cumulative gas production. Methane production, ammonia concentration and proportions of VFA were measured at 24 h. Concentration of aNDF (g/kg DM) ranged from 671 to 713 (grasses), 377 to 590 (leguminous shrubs) and 288 to 517 (non-leguminous shrubs). After 24 h of in vitro incubation, cumulative gas, CH4 production, ammonia concentration, proportion of propionate in VFA and IVDMD differed (p<0.05) within each forage type. B. ruziziensis and G. sepium produced the highest cumulative gas, IVDMD, total VFA, proportion of propionate in VFA and the lowest A:P ratios within their forage types. Consequently, these two species produced moderate CH4 emissions without compromising digestion. Grazing of these two species may be a strategy to reduce CH4 emissions however further assessment in in vivo trials and at different stages of maturity is recommended.

Modulation of persistent current in graphene quantum rings.

We investigate the effect of long-range impurity potentials on the persistent current of graphene quantum rings in the presence of an uniform perpendicular magnetic field. The impurity potentials are modeled as finite regions of the ring with a definite length. We show that, due to the relativistic and massless character of the charge carriers in graphene, the effect of such non-uniform potentials on the energy spectrum and on the persistent current of the rings can be reliably modeled by assuming a non-perturbed ring and including an additional phase due to the interaction of the charge carriers with the potential. In addition, the results show the presence of localized states in the impurity regions. Moreover, we show that for the case of a potential created by a p-n-p junction, the persistent current can be modulated by controlling the voltage at the junction.

The relationship of enamel defects and caries: a cohort study.

OBJECTIVE: Is there a relationship between enamel defects and early childhood caries? METHODS: A total of 275 children participated in a cohort study from birth to 54 months of age. Enamel defects were determined by the development defects enamel index and dental caries was registered according to the WHO criteria. Data were analyzed using descriptive, analytical techniques, multivariate analysis, and evidence-based tools as number needed to harm (NNH). RESULTS: In the follow up, 224 children were still in the study, 81.3% presented at least one tooth with enamel defect and 44.2% had dental caries. An association was found between enamel defects and dental caries (P = 0.0091). Multivariate analysis showed that night bottle-feeding, absence of fluoride and enamel defects were predictors of dental caries at 18 months (P < 0.05). Enamel defect was the only statistically significant variable to influence the development of caries at 24, 30, 36, and 42 months. At 48 months, the use of fluoride toothpaste had effect on the decrease of caries (P < 0.05). The NNH for enamel defects in relation to dental caries was 3.0, at 24 months and 5.0 at 54 months. CONCLUSION: Enamel defect is a predisposing factor for ECC.

Gap opening in graphene nanoribbons by application of simple shear strain and in-plane electric field.

The effects of shear strain and applied in plane electric field on the electronic properties of monolayer graphene nanoribbons (GNRs) are theoretically investigated. Band structures and the probability densities are calculated within the tight-binding model and the mechanical stresses submitted to the GNRs are taken into account by using the theory of linear elasticity with joint modifications in the elongation of the nearest-neighbor vectors and the modification of the hopping parameters. The energy gaps for specific widths of (semiconducting) armchair nanoribbons are verified also in the presence of either strain or field, whereas zigzag nanoribbons are metallic for any value of strain and exhibit a small gap for any value of field. However, our results demonstrate that when both strain and electric field are combined, a significant energy gap is always observed in the band structure, for any width or edge type of the ribbon. Moreover, the obtained total wave function is asymmetric along the ribbon width due to the applied electric field that pushes the electrons to one side of the ribbon and, under shear strain, a peak at the center of the ribbon in the spatial distribution is also observed owing to the preferable localization around the almost undeformed carbon bonds at ribbon center.

Apical hypertrophic cardiomyopathy: A case series at a Brazilian referral center with a maximal follow-up of 15 years.

BACKGROUND: Apical hypertrophic cardiomyopathy (AHCM) is a rare cardiomyopathy, in which hypertrophy occurs predominantly in the ventricular apex, and in some cases with a high risk of sudden cardiac death. OBJECTIVE: The aim of this paper is to present a case series of patients with AHCM and describe their main clinical, echocardiographic and electrocardiographic characteristics, the recommendation for an implantable cardioverter-defibrillator (ICD) and the frequency of sudden cardiac death (SCD). METHODS: A retrospective case series was conducted at the referral center of a federal teaching hospital, between the years 2005 to 2020, involving patients with an echocardiographic diagnosis of AHCM. The parameters of the American College of Cardiology and the European Society of Cardiology were used to assess the risk of SCD. RESULTS: A total of 11 individuals were assessed with a mean age of 55.3 years, mean follow-up of 41.2 months, most of whom were symptomatic at diagnosis (72.7%). The most frequent symptom was dyspnea (27.3%). A family history of SCD was described in 45.5% of cases. Due to a high risk of SCD, four patients received ICDs. One patient presented sudden cardiac death after having refused the ICD. CONCLUSIONS: Symptoms and alterations in the imaging exams are significant factors in the clinical and prognostic assessment of patients with AHCM.

[Factors associated to high-flow nasal cannula treatment failure in pediatric patients with respiratory failure in two pediatric intensive care units at high altitude]. / Factores asociados al fracaso de la terapia con cánulas nasales de alto flujo en pacientes pediátricos con insuficiencia respiratoria en dos unidades de cuidados críticos pediátricos a gran altitud.

INTRODUCTION: Acute respiratory failure is the leading cause of hospitalization in pediatrics. High-flow nasal cannulas (HFNCs) offer a new alternative, but the evidence and indications are still debated. The performance of HFNCs at high altitude has not been described to date. OBJECTIVE: To describe the use of HFNCs in pediatric patients admitted with respiratory failure and explore the factors associated with treatment failure. METHODOLOGY: A prospective cohort study was carried out in patients between 1 month and 18 years of age managed with HFNCs. The demographic and treatment response data were recorded at baseline and after 1, 6 and 24hours. The number of failures was determined, as well as the length of stay, complications and mortality. Patients with treatment failure were compared with the rest. RESULTS: A total of 539 patients were enrolled. Infants (70.9%) of male sex (58.4%) and airway diseases such as asthma and bronchiolitis (61.2%) were more frequent. There were 53 failures (9.8%), with 21 occurring in the first 24hours. The median length of stay was 4 days (IQR 4); there were 5 deaths (0.9%) and 13 adverse events (epistaxis) (2.2%). Improvement was observed in vital signs and severity over time, with differences in the group that failed, but without interactions. The final logistic model established an independent relationship of failure between the hospital (OR 2.78, 95%CI 1.48-5.21) and the initial respiratory rate (OR 1.56, 95%CI 1.21-2.01). CONCLUSIONS: HFNCs afford good clinical response, with few complications and a low failure rate. The differences found between institutions suggest a subjective relationship in the decision of therapy failure.

Effects of nonstructural carbohydrate concentration in alfalfa on fermentation and microbial protein synthesis in continuous culture.

Insufficient readily fermentable energy combined with extensive degradation of proteins in alfalfa (Medicago sativa L.) may result in poor forage N utilization by ruminants. Using the inherent genetic variability and differences between harvests, our objective was to compare the effect of contrasting concentrations of nonstructural carbohydrates (NSC) in alfalfa on rumen fermentation and microbial protein synthesis. Individual genotypes of the alfalfa cultivar AC Caribou grown near Québec City, Québec, Canada, were harvested at the vegetative and early flowering stages, dried at 55 degrees C, ground, and analyzed for soluble carbohydrates (fructose + sucrose + glucose + pinitol) and starch. Approximately 20 genotypes having, respectively, the highest and lowest NSC concentrations were pooled to constitute 2 contrasted 1-kg forage samples. Samples of high- (17.9% DM) and low- (7.4% DM) NSC alfalfa were respectively allocated to separate dual-flow fermenters in a completely randomized design with 3 replications. Rumen inoculum was obtained from 4 ruminally fistulated cows in early lactation that were fed a TMR with a 50:50 forage to concentrate ratio. A 10-d incubation period was used, with the first 6 d serving as an adaptation period followed by 4 d of sampling with solid and liquid dilution rates in the fermenters set at approximately 2.0 and 4.3%/h, respectively. High versus low NSC concentration in alfalfa significantly enhanced the apparent digestibility of OM (59.1% for high-NSC alfalfa vs. 54.4% for low-NSC alfalfa) and DM (60.0 vs. 54.3%) and the true digestibility of DM (74.1 vs. 64.7%). Increasing NSC concentration in alfalfa (high vs. low) significantly decreased ruminal pH (6.85 vs. 7.08) and NH(3)-N concentration (26.0 vs. 33.6 mg/dL) and increased total VFA concentration (94.9 vs. 83.0mM). Molar proportions of acetate, isobutyrate, and isovalerate significantly decreased, whereas molar proportions of propionate and butyrate significantly increased with high-NSC alfalfa, resulting in a more glucogenic fermentation. More importantly, microbial N flow (263 vs. 230 mg/d) and bacterial N efficiency (41.1 vs. 29.6% of available N), measured using (15)N as a microbial marker, both significantly increased with the high-NSC alfalfa. These results indicate that increasing the concentration of NSC in alfalfa promotes a glucogenic fermentation and enhances microbial N synthesis in the rumen.