Sensitive nanoscale magnetic resonance imaging of target spins using nitrogen-vacancy (NV) centers in diamond requires a quantitative understanding of dominant noise at the surface. We probe this ...noise by applying dynamical decoupling to shallow NVs at calibrated depths. Results support a model of NV dephasing by a surface bath of electronic spins having a correlation rate of 200 kHz, much faster than that of the bulk N spin bath. Our method of combining nitrogen delta-doping growth and nanoscale depth imaging paves a way for studying spin noise present in diverse material surfaces.
The recent discovery of graphene has led to many advances in two-dimensional physics and devices. The graphene devices fabricated so far have relied on SiO(2) back gating. Electrochemical top gating ...is widely used for polymer transistors, and has also been successfully applied to carbon nanotubes. Here we demonstrate a top-gated graphene transistor that is able to reach doping levels of up to 5x1013 cm-2, which is much higher than those previously reported. Such high doping levels are possible because the nanometre-thick Debye layer in the solid polymer electrolyte gate provides a much higher gate capacitance than the commonly used SiO(2) back gate, which is usually about 300 nm thick. In situ Raman measurements monitor the doping. The G peak stiffens and sharpens for both electron and hole doping, but the 2D peak shows a different response to holes and electrons. The ratio of the intensities of the G and 2D peaks shows a strong dependence on doping, making it a sensitive parameter to monitor the doping.
Hepatitis A virus (HAV) is a major causative agent of acute hepatitis worldwide. Although discovered in 1973, due to limitations of applicable serological and/or molecular methods, HAV remained under ...limited diagnosis until the late 1980s. This study aimed to retrospectively evaluate the serological and molecular prevalence of the HAV infection among 421 (n = 421) patients with a clinical and laboratory suspicion of acute hepatitis who were admitted in a reference laboratory in the Brazilian Eastern Amazon during 1982 and 1983. The 421 serum samples were screened for anti‐HAV IgM antibodies by enzymatic immunoassays. Positive samples were submitted to total RNA purification and tested by Nested reverse‐transcription polymerase chain reaction to amplify the HAV‐RNA VP1‐2A (522 bp) region. Anti‐HAV IgM antibodies were detected in 66% (278/421) of the patients. The highest prevalence was observed among males (57.9%, 161/278), and most often among children under 10 years old (63.3%, 176/278). HAV‐RNA was detected in 74.4% (207/278) of anti‐HAV IgM positive samples. HAV genotyping was performed in 71 samples, and 69 were classified into subgenotype IA. Two samples belonged to the HAV subgenotype IIIA. In this sense, retrospective studies can help in understanding the evolution and determination of wild genotypes and subtypes of HAV.
Highlights
Serological and molecular evaluation of 421 suspected cases of hepatitis A from the Brazilian Amazon in 1982 and 1983.
Anti‐HAV IgM antibodies were detected in 66% (278/421) of the patients.
Higher serological prevalence among children younger than 10 years old.
The HAV‐RNA was detected in 74.4% (207/278) of anti‐HAV IgM positive samples.
HAV genotyping was performed in 71 samples, and 69 were classified into subgenotype IA and two belonged to subgenotype IIIA.
We present first results on polarization swings in optical emission of blazars obtained by RoboPol, a monitoring programme of an unbiased sample of gamma-ray bright blazars specially designed for ...effective detection of such events. A possible connection of polarization swing events with periods of high activity in gamma-rays is investigated using the data set obtained during the first season of operation. It was found that the brightest gamma-ray flares tend to be located closer in time to rotation events, which may be an indication of two separate mechanisms responsible for the rotations. Blazars with detected rotations during non-rotating periods have significantly larger amplitude and faster variations of polarization angle than blazars without rotations. Our simulations show that the full set of observed rotations is not a likely outcome (probability ≤1.5 × 10−2) of a random walk of the polarization vector simulated by a multicell model. Furthermore, it is highly unlikely (∼5 × 10−5) that none of our rotations is physically connected with an increase in gamma-ray activity.
Visceral Leishmaniasis (VL) is a neglected tropical disease that afflicts some of the poorest populations in the world including people living in the Bihar state of India. Due to efforts from local ...governments, NGOs and international organizations, the number of VL cases has declined in recent years. Despite this progress, the reservoir for transmission remains to be clearly defined since it is unknown what role post kala-azar dermal leishmaniasis (PKDL) and asymptomatic infections play in transmission. This information is vital to establish effective surveillance and monitoring to sustainably eliminate VL.
We performed a longitudinal study over a 24-month period to examine VL transmission and seroconversion in households with VL, PKDL and asymptomatic infections in the Saran and Muzaffarpur districts of Bihar. During the initial screening of 5,144 people in 16 highly endemic villages, 195 cases of recently treated VL, 116 healthy rK39 positive cases and 31 PKDL cases were identified. Approximately half of the rK39-positive healthy cases identified during the initial 6-month screening period were from households (HHs) where a VL case had been identified. During the 18-month follow-up period, seroconversion of family members in the HHs with VL cases, PKDL cases, and rK39-positive individuals was similar to control HHs. Therefore, seroconversion was highest in HHs closest to the time of VL disease of a household member and there was no evidence of higher transmission in households with PKDL or healthy rK39-positive HHs. Moreover, within the PKDL HHs, (the initial 31 PKDL cases plus an additional 66 PKDL cases), there were no cases of VL identified during the initial screen or the 18-month follow-up. Notably, 23% of the PKDL cases had no prior history of VL suggesting that infection resulting directly in PKDL is more common than previously estimated.
These observations argue that acute VL cases represent the major reservoir for transmission in these villages and early identification and treatment of VL cases should remain a priority for VL elimination. We were unable to obtain evidence that transmission occurs in HHs with a PKDL case.
Little is known about clinical characteristics and management of severe yellow fever as previous yellow fever epidemics often occurred in times or areas with little access to intensive care units ...(ICU). We aim to describe the clinical characteristics of severe yellow fever cases requiring admission to the ICU during the 2018 yellow fever outbreak in São Paulo, Brazil. Furthermore, we report on preliminary lessons learnt regarding clinical management of severe yellow fever.
Retrospective descriptive cohort study. Demographic data, laboratory test results on admission, clinical follow-up, and clinical outcomes were evaluated.
From 10 January to 11 March 2018, 79 patients with laboratory confirmed yellow fever were admitted to the ICU in a tertiary hospital in Sao Paolo because of rapid clinical deterioration. On admission, the median AST was 7,000 IU/L, ALT 3,936 IU/L, total bilirubin 5.3 ml/dL, platelet 74 × 103/mm3, INR 2.24 and factor V 37%. Seizures occurred in 24% of patients, even without substantial intracranial hypertension. The high frequency of pancreatitis and rapidly progressive severe metabolic acidosis were notable findings. 73% of patients required renal replacement therapy. The in-hospital fatality rate was 67%. Patients with diabetes mellitus had a higher case fatality rate (CFR) of 80%, while patients without diabetes had a CFR of 65%. Leading causes of death were severe gastrointestinal bleeding, epileptic status, severe metabolic acidosis, necrohemorrhagic pancreatitis, and multi-organ failure.
Severe yellow fever is associated with a high CFR. The following management lessons were learnt: Anticonvulsant drugs in patients with any symptoms of hepatic encephalopathy or arterial ammonia levels >70 μmol/L was commenced which reduced the frequency of seizures from 28% to 17%. Other new therapy strategies included early institution of plasma exchange. Due to the high frequency of gastric bleeding, therapeutic doses of intravenous proton pump inhibitors should be administered.
Understanding the causes and timing of death in extremely premature infants may guide research efforts and inform the counseling of families.
We analyzed prospectively collected data on 6075 deaths ...among 22,248 live births, with gestational ages of 22 0/7 to 28 6/7 weeks, among infants born in study hospitals within the National Institute of Child Health and Human Development Neonatal Research Network. We compared overall and cause-specific in-hospital mortality across three periods from 2000 through 2011, with adjustment for baseline differences.
The number of deaths per 1000 live births was 275 (95% confidence interval CI, 264 to 285) from 2000 through 2003 and 285 (95% CI, 275 to 295) from 2004 through 2007; the number decreased to 258 (95% CI, 248 to 268) in the 2008-2011 period (P=0.003 for the comparison across three periods). There were fewer pulmonary-related deaths attributed to the respiratory distress syndrome and bronchopulmonary dysplasia in 2008-2011 than in 2000-2003 and 2004-2007 (68 95% CI, 63 to 74 vs. 83 95% CI, 77 to 90 and 84 95% CI, 78 to 90 per 1000 live births, respectively; P=0.002). Similarly, in 2008-2011, as compared with 2000-2003, there were decreases in deaths attributed to immaturity (P=0.05) and deaths complicated by infection (P=0.04) or central nervous system injury (P<0.001); however, there were increases in deaths attributed to necrotizing enterocolitis (30 95% CI, 27 to 34 vs. 23 95% CI, 20 to 27, P=0.03). Overall, 40.4% of deaths occurred within 12 hours after birth, and 17.3% occurred after 28 days.
We found that from 2000 through 2011, overall mortality declined among extremely premature infants. Deaths related to pulmonary causes, immaturity, infection, and central nervous system injury decreased, while necrotizing enterocolitis-related deaths increased. (Funded by the National Institutes of Health.).
•Review on application of Sugercane Bagase in its original form.•Review on treated Sugercane Bagase and its applications.•Review on manipulation of manufacturing methodologies.
The natural, ...bio-degradable features and chemical constituents of the sugarcane bagasse (SCB) have been attracting attention as a highly potential and versatile ingredient in composite materials. Eco-friendly and low cost considerations have set the momentum for material science researchers to identify green materials that give low pollutant indexes. Various components of SCB is shown to possess the ability of being applied as raw material for manufacturing of composite materials at multiple levels of properties and performances. Studies on the impacts, performances and applications of SCB in its original condition; transformed forms; treated with appropriate chemicals and/or processes; in combination with materials of distinct properties and manipulation of manufacturing methodologies have been duly considered. This paper attempts to summarize a review of current literature on the extensive studies that have been undertaken in an attempt to explore plausible applications and potentials of SCB for composite material.
ABSTRACT
We present the design and performance of RoboPol, a four-channel optical polarimeter operating at the Skinakas Observatory in Crete, Greece. RoboPol is capable of measuring both relative ...linear Stokes parameters q and u (and the total intensity I) in one sky exposure. Though primarily used to measure the polarization of point sources in the R band, the instrument features additional filters (B, V, and I), enabling multiwavelength imaging polarimetry over a large field of view (13.6′ × 13.6′). We demonstrate the accuracy and stability of the instrument throughout its 5 yr of operation. Best performance is achieved within the central region of the field of view and in the R band. For such measurements the systematic uncertainty is below 0.1 per cent in fractional linear polarization, p (0.05 per cent maximum likelihood). Throughout all observing seasons the instrumental polarization varies within 0.1 per cent in p and within ∼1° in polarization angle.
Neutrinos are one of the most promising messengers for signals of new physics Beyond the Standard Model (BSM). On the theoretical side, their elusive nature, combined with their unknown mass ...mechanism, seems to indicate that the neutrino sector is indeed opening a window to new physics. On the experimental side, several long-standing anomalies have been reported in the past decades, providing a strong motivation to thoroughly test the standard three-neutrino oscillation paradigm. In this Snowmass21 white paper, we explore the potential of current and future neutrino experiments to explore BSM effects on neutrino flavor during the next decade.
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