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1.
Clin Radiol ; 79(4): 303-311, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38310059

RESUMO

AIM: To determine the frequency and classification of addenda seen in paediatric brain magnetic resonance imaging (MRI) reports. MATERIALS AND METHODS: A retrospective review of the addenda of brain MRI reports from a large tertiary children's hospital was undertaken between January 2013 to December 2021 and a subset of above radiology reports was used to classify addenda over 6-month periods, October to March, spanning 2018 to 2021. A radiology fellow and a medical doctor classified the addenda into previously published categories using their best judgement. RESULTS: Out of 73,643 brain MRI reports over 9 years (108 months) included in the study, only 923 reports (1.25%) had addenda. There was a total of 13,615 brain MRI reports from 6-month periods, of which only 179 reports (1.31%) had an addendum. The number of errors according to categories were: observational 88/13,615 (0.65%); interpretational 16/13,615 (0.12%); non-observational and non-interpretative 82/13,615 (0.6%). Notifications to referring physician made in 29/13,615 (0.21%). CONCLUSIONS: The overall proportion of addenda to the brain MRI reports of children in the present study was low, at 1.25%. Categorisation of different addenda revealed the most common errors to be observational in 0.65%, including under-reading in the region of interest in 0.25%. Appropriate measures can now be introduced to minimise the error-based addenda further and improve MRI diagnosis in children. Other paediatric practices may choose to follow suit in evaluating their addenda and errors to improve practice.


Assuntos
Imageamento por Ressonância Magnética , Radiologia , Humanos , Criança , Erros de Diagnóstico , Relatório de Pesquisa , Estudos Retrospectivos
2.
Phys Rev Lett ; 131(1): 011801, 2023 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-37478458

RESUMO

Neutrino-induced charged-current single π^{+} production in the Δ(1232) resonance region is of considerable interest to accelerator-based neutrino oscillation experiments. In this Letter, high statistic differential cross sections are reported for the semiexclusive reaction ν_{µ}A→µ^{-}π^{+}+ nucleon(s) on scintillator, carbon, water, iron, and lead targets recorded by MINERvA using a wideband ν_{µ} beam with ⟨E_{ν}⟩≈6 GeV. Suppression of the cross section at low Q^{2} and enhancement of low T_{π} are observed in both light and heavy nuclear targets compared with phenomenological models used in current neutrino interaction generators. The cross sections per nucleon for iron and lead compared with CH across the kinematic variables probed are 0.8 and 0.5 respectively, a scaling which is also not predicted by current generators.

3.
Phys Rev Lett ; 131(5): 051801, 2023 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-37595210

RESUMO

MINERvA has measured the ν_{µ}-induced coherent π^{+} cross section simultaneously in hydrocarbon (CH), graphite (C), iron (Fe), and lead (Pb) targets using neutrinos from 2 to 20 GeV. The measurements exceed the predictions of the Rein-Sehgal and Berger-Sehgal PCAC based models at multi-GeV ν_{µ} energies and at produced π^{+} energies and angles, E_{π}>1 GeV and θ_{π}<10°. Measurements of the cross-section ratios of Fe and Pb relative to CH reveal the effective A scaling to increase from an approximate A^{1/3} scaling at few GeV to an A^{2/3} scaling for E_{ν}>10 GeV.

4.
Public Health ; 225: 160-167, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37931485

RESUMO

OBJECTIVE: Current national severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination policy covers children aged >12 years. Unvaccinated, uninfected children remain susceptible to SARS-CoV-2 and play a role in community transmission, as paediatric infection is mostly mild or asymptomatic. To estimate the proportion of susceptible children in a community for public health measures, there is a need to assess the extent of natural infection. STUDY DESIGN: We performed a cross-sectional household serosurvey of SARS-CoV-2 antibodies in unvaccinated children aged between 6 and 18 years after the second COVID-19 wave. METHODS: Anti-SARS-CoV-2 immunoglobin G (IgG) testing in serum was done using chemiluminescence immunoassay. We used a logistic regression model to investigate predicted factors of seropositivity. RESULTS: We observed a high prevalence (weighted average: 68.3%) of anti-SARS-CoV-2 IgG in 2700 enrolled children. Logistic regression for predictors of IgG seropositivity showed lower odds in households with completely vaccinated adults (adjusted odds ratio [OR]: 0.43, 95% confidence interval [CI]: 0.26-0.71, P = 0.0011) compared with households with unvaccinated adults. Other factors for low seropositivity included frontline workers as family members (adjusted OR: 0.69, 95% CI: 0.52-0.91, P = 0.0091) and non-crowded households (adjusted OR: 0.74, 95% CI: 0.61-0.89, P = 0.0019). CONCLUSION: A high SARS-CoV-2 IgG prevalence in unvaccinated children was indicative of previous exposure to potentially infected contacts. This implies in-person academic activities for children can be continued during future community transmission. Comparatively lower seropositivity in children of completely vaccinated households or frontline workers suggests decreased transmission due to vaccination-induced immunity of family members. Vaccination will still be required in these children to maintain protective IgG levels, particularly in low seroprevalence groups.


Assuntos
COVID-19 , SARS-CoV-2 , Adulto , Criança , Humanos , Adolescente , Pandemias , Estudos Transversais , Prevalência , Estudos Soroepidemiológicos , COVID-19/epidemiologia , Índia/epidemiologia , Imunoglobulina G
5.
Basic Res Cardiol ; 117(1): 39, 2022 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-35970954

RESUMO

The Hatter Cardiovascular Institute biennial workshop, originally scheduled for April 2020 but postponed for 2 years due to the Covid pandemic, was organised to debate and discuss the future of Remote Ischaemic Conditioning (RIC). This evolved from the large multicentre CONDI-2-ERIC-PPCI outcome study which demonstrated no additional benefit when using RIC in the setting of ST-elevation myocardial infarction (STEMI). The workshop discussed how conditioning has led to a significant and fundamental understanding of the mechanisms preventing cell death following ischaemia and reperfusion, and the key target cyto-protective pathways recruited by protective interventions, such as RIC. However, the obvious need to translate this protection to the clinical setting has not materialised largely due to the disconnect between preclinical and clinical studies. Discussion points included how to adapt preclinical animal studies to mirror the patient presenting with an acute myocardial infarction, as well as how to refine patient selection in clinical studies to account for co-morbidities and ongoing therapy. These latter scenarios can modify cytoprotective signalling and need to be taken into account to allow for a more robust outcome when powered appropriately. The workshop also discussed the potential for RIC in other disease settings including ischaemic stroke, cardio-oncology and COVID-19. The workshop, therefore, put forward specific classifications which could help identify so-called responders vs. non-responders in both the preclinical and clinical settings.


Assuntos
Isquemia Encefálica , COVID-19 , Precondicionamento Isquêmico Miocárdico , Acidente Vascular Cerebral , Animais , Educação , Isquemia , Resultado do Tratamento
6.
Phys Rev Lett ; 129(2): 021803, 2022 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-35867435

RESUMO

Neutrino charged-current quasielastic-like scattering, a reaction category extensively used in neutrino oscillation measurements, probes nuclear effects that govern neutrino-nucleus interactions. This Letter reports the first measurement of the triple-differential cross section for ν_{µ} quasielastic-like reactions using the hydrocarbon medium of the MINERvA detector exposed to a wideband beam spanning 2≤E_{ν}≤20 GeV. The measurement maps the correlations among transverse and longitudinal muon momenta and summed proton kinetic energies, and compares them to predictions from a state-of-art simulation. Discrepancies are observed that likely reflect shortfalls with modeling of pion and nucleon intranuclear scattering and/or spectator nucleon ejection from struck nuclei. The separate determination of leptonic and hadronic variables can inform experimental approaches to neutrino-energy estimation.

7.
Clin Radiol ; 77(10): e776-e782, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35940927

RESUMO

AIM: To compare targeted and global liver stiffness measured by magnetic resonance elastography (MRE) with liver biopsy in patients who have undergone the Fontan procedure, and to assess the relationship between liver stiffness and fibrosis stage. MATERIALS AND METHODS: Targeted and global liver stiffness was compared with a quantification of liver fibrosis measured by percentage of Sirius Red (%SR) staining of biopsy samples. MRE values were compared with three other biopsy-scoring methods: Ishak, Scheuer/Ludwig-Batts/Metavir, and congestive hepatic fibrosis score (CHFS). Additionally, in patients who had two or more MRE studies, global liver stiffness was compared for longitudinal assessment. RESULTS: Thirty-four patients were included in the study, with a mean age of 16.2 years. There was no statistically significant correlation between MRE-derived liver stiffness and Ishak score, Metavir score, %SR staining, and CHFS score. Twenty patients had multiple MRE studies, with a mean age of 16.5 years, and these showed a statistically significant increase in mean liver stiffness from 3.72 to 4.68 (26% increase) within an average period of 24 months. CONCLUSIONS: The lack of correlation of liver stiffness with fibrosis stage observed in this study indicates that the effects of venous congestion in Fontan patients can confound the use of liver stiffness as a biomarker for fibrosis as assessed by percentage of SR staining, Ishak score, Metavir score, and CHFS score. These results provide motivation for further development of magnetic resonance imaging-based biomarkers to increase the specificity in the assessment of Fontan-associated liver disease. A steady increase in liver stiffness observed in these patients may be useful for longitudinal follow-up of liver health.


Assuntos
Técnicas de Imagem por Elasticidade , Técnica de Fontan , Hiperemia , Hepatopatias , Adolescente , Técnicas de Imagem por Elasticidade/métodos , Fibrose , Técnica de Fontan/efeitos adversos , Humanos , Hiperemia/diagnóstico por imagem , Hiperemia/etiologia , Hiperemia/patologia , Fígado/diagnóstico por imagem , Fígado/patologia , Cirrose Hepática/patologia , Hepatopatias/etiologia , Imageamento por Ressonância Magnética/métodos , Estudos Retrospectivos
8.
Mol Genet Metab ; 132(2): 94-99, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-32713717

RESUMO

Respiratory outcomes in Mucopolysaccharidosis Type I (MPS I), have mainly focused on upper airway obstruction, with the evolution of the restrictive lung disease being poorly documented. We report the long-term pulmonary function outcomes and examine the potential factors affecting these in 2 cohorts of MPS I patients, those who have undergone Haematopoietic Stem Cell Transplantation (HSCT) and those treated with Enzyme Replacement Therapy (ERT). The results were stratified using the American Thoracic Society (ATS) guidelines. 66 patients, capable of adequately performing testing, were identified by a retrospective case note review, 46 transplanted (45 Hurler, 1 Non-Hurler) and 20 having ERT (17 Non-Hurler and 3 Hurler diagnosed too late for HSCT). 5 patients died; 4 in the ERT group including the 3 Hurler patients. Overall 14% of patients required respiratory support (non-invasive ventilation (NIV) or supplemental oxygen)) at the end of follow up. Median length of follow-up was 12.2 (range = 4.9-32) years post HSCT and 14.34 (range = 3.89-20.4) years on ERT. All patients had restrictive lung disease. Cobb angle and male sex were significantly associated with more severe outcomes in the HSCT cohort, with 49% having severe to very severe disease. In the 17 Non-Hurler ERT treated patients there was no variable predictive of severity of disease with 59% having severe to very severe disease. During the course of follow up 67% of the HSCT cohort had no change or improved pulmonary function as did 52% of the ERT patients. However, direct comparison between therapeutic modalities was not possible. This initial evidence would suggest that a degree of restrictive lung disease is present in all treated paediatrically diagnosed MPS I and is still a significant cause of morbidity, though further stratification incorporating diffusing capacity for carbon monoxide (DLCO) is needed.


Assuntos
Obstrução das Vias Respiratórias/terapia , Pneumopatias Obstrutivas/terapia , Mucopolissacaridose I/terapia , Adolescente , Adulto , Idade de Início , Idoso , Idoso de 80 Anos ou mais , Obstrução das Vias Respiratórias/complicações , Obstrução das Vias Respiratórias/epidemiologia , Obstrução das Vias Respiratórias/patologia , Monóxido de Carbono/metabolismo , Criança , Pré-Escolar , Terapia de Reposição de Enzimas , Feminino , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Humanos , Lactente , Pneumopatias Obstrutivas/complicações , Pneumopatias Obstrutivas/epidemiologia , Pneumopatias Obstrutivas/patologia , Masculino , Pessoa de Meia-Idade , Mucopolissacaridose I/complicações , Mucopolissacaridose I/epidemiologia , Mucopolissacaridose I/patologia , Adulto Jovem
9.
Diabet Med ; 38(4): e14368, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-32743838

RESUMO

AIM: This prospective observational study evaluated the role of infrared (IR) dermal thermometry in the management of diabetic foot ulcers. METHODS: Thirty participants with unilateral neuropathic diabetic foot ulcers of University of Texas grade 1 or 2 (stage A) were followed up monthly for 1 year. At each visit, skin temperatures were measured with an IR dermal thermometer at corresponding sites on both feet, using the contralateral feet without ulcers as controls. RESULTS: Average temperature and ulcer temperature in affected feet were significantly higher than in unaffected feet, with a mean difference of 1.2 °C [95% confidence interval (CI) 0.7 to 1.7] and 3.1 °C (95% CI 2.3 to 3.9), respectively. Although the gradient between average temperature of affected foot and that of unaffected foot normalized (mean difference 0.2 °C, 95% CI -0.2 to 0.7) at healing, the temperature gradient between the ulcer and a corresponding site on the unaffected foot decreased but did not normalize (mean difference 2.1 °C, 95% CI 1.2 to 3.1) even at healing, as documented by skin closure, and persisted for up to 1 month after skin closure. A gradient of ≥1 °C between average temperature of affected foot and that of unaffected foot at initial presentation or at any time during ulcer healing was found to predict impaired healing and should alert clinicians to ulcers requiring more attention. An incremental trend in temperature gradient (median difference 2.2 °C; range 0.1-6.3 °C) at a site on the foot was predictive of a recurrent ulcer involving the same site. CONCLUSIONS: IR dermal thermometry may have a role in predicting diabetic foot ulcer healing, in determining the completeness of healing and in guiding the duration of offloading. Serial monitoring of the temperature gradient may predict the development of recurrent diabetic foot ulcers.


Assuntos
Pé Diabético/terapia , Raios Infravermelhos/uso terapêutico , Termometria/métodos , Adulto , Temperatura Corporal , Estudos de Casos e Controles , Pé Diabético/diagnóstico , Pé Diabético/patologia , Pé Diabético/fisiopatologia , Progressão da Doença , Feminino , Pé/fisiopatologia , Humanos , Índia , Masculino , Pessoa de Meia-Idade , Gravidade do Paciente , Prognóstico , Cicatrização/fisiologia
10.
Br J Dermatol ; 184(6): 1132-1142, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33152110

RESUMO

BACKGROUND: The absence of melanocytes poses a challenge for long-term tissue homeostasis in vitiligo. Surprisingly, while individuals with Fitzpatrick phototypes I-II (low melanin content) have a higher incidence of melanoma and nonmelanoma skin cancer, people with vitiligo are at a decreased risk for the same. OBJECTIVES: To understand the molecular mechanisms that protect vitiligo skin from ultraviolet (UV)-induced DNA damage by (i) characterizing differentially expressed microRNAs in lesional vs. nonlesional epidermis and (ii) identifying their upstream regulators and downstream gene targets. METHODS: Genome-wide microRNA profiling of nonlesional and lesional epidermis was performed on five individuals with stable nonsegmental vitiligo using next-generation RNA sequencing. The relevance of the upstream regulator and downstream target gene of the most differentially expressed microRNA was studied. RESULTS: Our study found sirtuin1 (SIRT1), an NAD-dependent deacetylase, to be a direct target of miR-211 - the most significantly downregulated microRNA in lesional epidermis. Inhibition of SIRT1 with EX-527 downregulated keratin 10 and involucrin, suggesting that SIRT1 promotes keratinocyte differentiation. Overexpression of miR-211 mimic led to a significant increase in γ-H2AX positivity and cyclobutane pyrimidine dimer (CPD) formation, hallmarks of UVB-mediated DNA damage. These effects could be ameliorated by the addition of resveratrol, a SIRT1 activator. Furthermore, a long noncoding RNA, MALAT1, was identified as a negative upstream regulator of miR-211. Overexpression of MALAT1 resulted in increased expression of SIRT1 and a concomitant removal of UVB-induced CPDs in primary keratinocytes. CONCLUSIONS: These findings establish a novel MALAT1-miR-211-SIRT1 signalling axis that potentially confers protection to the 'amelanotic' keratinocytes in vitiligo.


Assuntos
Dano ao DNA , MicroRNAs , RNA Longo não Codificante , Sirtuína 1 , Raios Ultravioleta/efeitos adversos , Vitiligo , Epiderme , Humanos , MicroRNAs/genética , RNA Longo não Codificante/genética , Sirtuína 1/genética , Vitiligo/genética
11.
J Exp Biol ; 224(23)2021 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-34755862

RESUMO

Lantern bugs are amongst the largest of the jumping hemipteran bugs, with body lengths reaching 44 mm and masses reaching 0.7 g. They are up to 600 times heavier than smaller hemipterans that jump powerfully using catapult mechanisms to store energy. Does a similar mechanism also propel jumping in these much larger insects? The jumping performance of two species of lantern bugs (Hemiptera, Auchenorrhyncha, family Fulgoridae) from India and Malaysia was therefore analysed from high-speed videos. The kinematics showed that jumps were propelled by rapid and synchronous movements of both hind legs, with their trochantera moving first. The hind legs were 20-40% longer than the front legs, which was attributable to longer tibiae. It took 5-6 ms to accelerate to take-off velocities reaching 4.65 m s-1 in the best jumps by female Kalidasa lanata. During these jumps, adults experienced an acceleration of 77 g, required an energy expenditure of 4800 µJ and a power output of 900 mW, and exerted a force of 400 mN. The required power output of the thoracic jumping muscles was 21,000 W kg-1, 40 times greater than the maximum active contractile limit of muscle. Such a jumping performance therefore required a power amplification mechanism with energy storage in advance of the movement, as in their smaller relatives. These large lantern bugs are near isometrically scaled-up versions of their smaller relatives, still achieve comparable, if not higher, take-off velocities, and outperform other large jumping insects such as grasshoppers.


Assuntos
Hemípteros , Animais , Fenômenos Biomecânicos , Extremidades , Feminino , Locomoção , Músculo Esquelético
12.
Public Health ; 198: 273-279, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34492508

RESUMO

OBJECTIVES: The role of overcrowded and multigenerational households as a risk factor for COVID-19 remains unmeasured. The objective of this study is to examine and quantify the association between overcrowded and multigenerational households and COVID-19 in New York City (NYC). STUDY DESIGN: Cohort study. METHODS: We conducted a Bayesian ecological time series analysis at the ZIP Code Tabulation Area (ZCTA) level in NYC to assess whether ZCTAs with higher proportions of overcrowded (defined as the proportion of the estimated number of housing units with more than one occupant per room) and multigenerational households (defined as the estimated percentage of residences occupied by a grandparent and a grandchild less than 18 years of age) were independently associated with higher suspected COVID-19 case rates (from NYC Department of Health Syndromic Surveillance data for March 1 to 30, 2020). Our main measure was an adjusted incidence rate ratio (IRR) of suspected COVID-19 cases per 10,000 population. Our final model controlled for ZCTA-level sociodemographic factors (median income, poverty status, White race, essential workers), the prevalence of clinical conditions related to COVID-19 severity (obesity, hypertension, coronary heart disease, diabetes, asthma, smoking status, and chronic obstructive pulmonary disease), and spatial clustering. RESULTS: 39,923 suspected COVID-19 cases were presented to emergency departments across 173 ZCTAs in NYC. Adjusted COVID-19 case rates increased by 67% (IRR 1.67, 95% CI = 1.12, 2.52) in ZCTAs in quartile four (versus one) for percent overcrowdedness and increased by 77% (IRR 1.77, 95% CI = 1.11, 2.79) in quartile four (versus one) for percent living in multigenerational housing. Interaction between both exposures was not significant (ßinteraction = 0.99, 95% CI: 0.99-1.00). CONCLUSIONS: Overcrowdedness and multigenerational housing are independent risk factors for suspected COVID-19. In the early phase of the surge in COVID cases, social distancing measures that increase house-bound populations may inadvertently but temporarily increase SARS-CoV-2 transmission risk and COVID-19 disease in these populations.


Assuntos
COVID-19 , Teorema de Bayes , Estudos de Coortes , Humanos , SARS-CoV-2 , Fatores Socioeconômicos
13.
Med J Armed Forces India ; 77(4): 403-407, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34594067

RESUMO

BACKGROUND: Soldiers native to lowlands, while sojourning at high altitude (HA), are referred to tertiary care centers with electrocardiographic (ECG) abnormalities. Exposure to HA may precipitate myocardial ischemia in subjects with underlying coronary artery disease (CAD). Conversely, it may produce physiological ECG changes mimicking those of CAD, causing a diagnostic dilemma. This study sought to correlate the presence of CAD on coronary angiography (CAG) with a putative diagnosis of CAD based on clinical findings and ECG. METHODS: A prospective study was conducted on patient's from HA areas, referred for evaluation for CAD to a single center at near-sea-level. Thirty-five minimally symptomatic/asymptomatic soldiers with ECG changes suggestive of CAD, underwent CAG. Correlation was sought between ECG and CAG evidence of CAD. RESULTS: The association of CAD on CAG with clinical and ECG diagnosis of CAD was not significant, 4 of the 35 soldiers (11.4%) showing CAG evidence of CAD (chi square 3.849, p = 0.697). The association between symptoms and coronary artery lesions was, also, not significant, only four of twenty-three (17.4%) minimally symptomatic subjects having CAD on CAG. CONCLUSION: Insignificant numbers of previously healthy persons, who present with minimal symptoms and ECG changes suggestive of CAD while sojourning at HA, have coronary artery involvement on CAG. Those with incidental ECG changes, without symptomatology, do not have CAD on CAG.

14.
Phys Rev Lett ; 124(12): 121801, 2020 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-32281855

RESUMO

We measure neutrino charged-current quasielasticlike scattering on hydrocarbon at high statistics using the wideband Neutrinos at the Main Injector beam with neutrino energy peaked at 6 GeV. The double-differential cross section is reported in terms of muon longitudinal (p_{∥}) and transverse (p_{⊥}) momentum. Cross section contours versus lepton momentum components are approximately described by a conventional generator-based simulation, however, discrepancies are observed for transverse momenta above 0.5 GeV/c for longitudinal momentum ranges 3-5 and 9-20 GeV/c. The single differential cross section versus momentum transfer squared (dσ/dQ_{QE}^{2}) is measured over a four-decade range of Q^{2} that extends to 10 GeV^{2}. The cross section turnover and falloff in the Q^{2} range 0.3-10 GeV^{2} is not fully reproduced by generator predictions that rely on dipole form factors. Our measurement probes the axial-vector content of the hadronic current and complements the electromagnetic form factor data obtained using electron-nucleon elastic scattering. These results help oscillation experiments because they probe the importance of various correlations and final-state interaction effects within the nucleus, which have different effects on the visible energy in detectors.

15.
Phys Chem Chem Phys ; 22(16): 8557-8564, 2020 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-32255091

RESUMO

Alkali metal dimers attached to the surface of helium nanodroplets are found to be efficiently doubly ionized by electron transfer mediated decay (ETMD) when photoionizing the helium droplets. This process is evidenced by detecting in coincidence two energetic ions created by Coulomb explosion and one low-kinetic energy electron. The kinetic energy spectra of ions and electrons are reproduced by simple model calculations based on diatomic potential energy curves, and are in agreement with ab initio calculations for the He-Na2 and He-KRb systems. This work demonstrates that ETMD is an important decay channel in heterogeneous nanosystems exposed to ionizing radiation.

16.
Nature ; 513(7517): 219-23, 2014 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-25209800

RESUMO

The hydroxyl radical (OH) is a key oxidant involved in the removal of air pollutants and greenhouse gases from the atmosphere. The ratio of Northern Hemispheric to Southern Hemispheric (NH/SH) OH concentration is important for our understanding of emission estimates of atmospheric species such as nitrogen oxides and methane. It remains poorly constrained, however, with a range of estimates from 0.85 to 1.4 (refs 4, 7-10). Here we determine the NH/SH ratio of OH with the help of methyl chloroform data (a proxy for OH concentrations) and an atmospheric transport model that accurately describes interhemispheric transport and modelled emissions. We find that for the years 2004-2011 the model predicts an annual mean NH-SH gradient of methyl chloroform that is a tight linear function of the modelled NH/SH ratio in annual mean OH. We estimate a NH/SH OH ratio of 0.97 ± 0.12 during this time period by optimizing global total emissions and mean OH abundance to fit methyl chloroform data from two surface-measurement networks and aircraft campaigns. Our findings suggest that top-down emission estimates of reactive species such as nitrogen oxides in key emitting countries in the NH that are based on a NH/SH OH ratio larger than 1 may be overestimated.


Assuntos
Atmosfera/química , Radical Hidroxila/química , Modelos Teóricos , Poluentes Atmosféricos/química , Clorofórmio/química , Simulação por Computador , Óxidos de Nitrogênio/química
17.
Proc Natl Acad Sci U S A ; 114(46): 12156-12161, 2017 11 14.
Artigo em Inglês | MEDLINE | ID: mdl-29087326

RESUMO

We propose a hitherto-unexplored concept in quantum thermodynamics: catalysis of heat-to-work conversion by quantum nonlinear pumping of the piston mode which extracts work from the machine. This concept is analogous to chemical reaction catalysis: Small energy investment by the catalyst (pump) may yield a large increase in heat-to-work conversion. Since it is powered by thermal baths, the catalyzed machine adheres to the Carnot bound, but may strongly enhance its efficiency and power compared with its noncatalyzed counterparts. This enhancement stems from the increased ability of the squeezed piston to store work. Remarkably, the fraction of piston energy that is convertible into work may then approach unity. The present machine and its counterparts powered by squeezed baths share a common feature: Neither is a genuine heat engine. However, a squeezed pump that catalyzes heat-to-work conversion by small investment of work is much more advantageous than a squeezed bath that simply transduces part of the work invested in its squeezing into work performed by the machine.

18.
Environ Monit Assess ; 192(2): 122, 2020 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-31953601

RESUMO

Chilika Lake is the largest coastal lagoon in Asia and the second largest in the world covering an area of 1100 km2 and spread over three districts of Odisha state of India. It is the first Indian wetland designated as a wetland of international importance under the Ramsar Convention in 1981. The lake ecosystem sustains large and diversified resources of plants and animals including fisheries. Pollution of the ecosystem caused by residues of pesticides originating from different sources was assessed through multiple sampling from 2012 to 2016 from three potential sites of contamination, viz., Palur Bridge, Daya River Estuary, and Makara River. Incidence of organochlorinated (OC) pesticide residues was noticed in about 25% water samples. HCH (α, γ&δ), DDD (op|), DDE (op|&pp.|) and heptachlor were the OCs detected in concentration varying from 0.025 to 23.4 µg/l. None of the eight targeted synthetic pyrethroid (SP) pesticides was found in water, but among the organophosphates (OP), chlorpyrifos (0.019-2.73 µg/l), and dichlorvos (0.647 µg/l) were recorded. In sediment samples, residues of OC or OP pesticides were not present, but one SP pesticide was recorded. Fish samples were contaminated to the extent of 55%, mostly with residues of OCs and OPs and less with SPs. However, their concentrations were below the permissible limit, so there was no direct threat of health hazards to humans.


Assuntos
Monitoramento Ambiental , Resíduos de Praguicidas/análise , Poluentes Químicos da Água/análise , Animais , Ecossistema , Peixes , Heptacloro/análise , Hidrocarbonetos Clorados/análise , Índia , Inseticidas , Lagos/química , Praguicidas/análise , Piretrinas , Rios/química , Áreas Alagadas
19.
J Appl Microbiol ; 126(4): 1233-1244, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30614180

RESUMO

AIMS: To evaluate the protective efficacy of Pediococcus pentosaceus GS4 in cadmium (Cd)-induced toxicity in Swiss albino mice. METHODS AND RESULTS: The previously reported probiotic P. pentosaceus GS4 interaction with Cd was evaluated experimentally. Swiss albino mice were segregated randomly into three different groups containing nine animals each. The binding ability of P. pentosaceus GS4 and Cd was demonstrated by atomic absorption spectrometry, Fourier transform infrared spectroscopy and scanning electron microscopy analysis respectively. Cd challenge was attenuated by the P. pentosaceus GS4 treatment and was evaluated by estimating Cd level in liver and faeces, corresponding biomarkers for toxicity in liver and intestines and histopathological analysis with brush border membrane (BBM) integrity. Results showed that P. pentosaceus GS4 bound Cd effectively. Pediococcus pentosaceus GS4 intervention significantly enhanced faecal evacuation of Cd with an effect of reduced tissue deposition. Histologically, Cd-induced gut was found significantly replenished with lactobacilli in addition to reduced hyperplasia, lowered lymphocytes infiltration and enhancement of BBM-based disaccharidases, proving its role in protecting membrane integrity. CONCLUSIONS: Probiotic P. pentosaceus GS4 efficiently alleviated toxicity from vital organs such as liver and intestine caused by Cd exposure in a murine model. SIGNIFICANCE AND IMPACT OF THE STUDY: Intervention of P. pentosaceus GS4 alleviated Cd-induced toxicity, and thus it may be employed therapeutically to protect Cd toxicity.


Assuntos
Cádmio/toxicidade , Fígado/efeitos dos fármacos , Microvilosidades/efeitos dos fármacos , Pediococcus pentosaceus/fisiologia , Probióticos/uso terapêutico , Animais , Cádmio/metabolismo , Fezes/química , Microbioma Gastrointestinal/efeitos dos fármacos , Intestinos/efeitos dos fármacos , Intestinos/imunologia , Intestinos/microbiologia , Intestinos/patologia , Fígado/metabolismo , Camundongos , Microvilosidades/enzimologia , Microvilosidades/patologia , Pediococcus pentosaceus/metabolismo , Probióticos/metabolismo
20.
Med Vet Entomol ; 33(3): 375-387, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-30913314

RESUMO

Chikungunya virus (CHIKV) is primarily transmitted by Aedes spp. mosquitoes. The present study investigated vector competence for CHIKV in Aedes aegypti and Aedes albopictus mosquitoes found in Madurai, South India. The role of receptor proteins on midguts contributing to permissiveness of CHIKV to Aedes spp. mosquitoes was also undertaken. Mosquitoes were orally infected with CHIKV DRDE-06. Infection of midguts and dissemination to heads was confirmed by immunofluorescence assay at different time points. A plaque assay was performed from mosquito homogenates at different time points to study CHIKV replication. Presence of putative CHIKV receptor proteins on mosquito midgut epithelial cells was detected by virus overlay protein binding assay (VOPBA). The identity of these proteins was established using mass spectrometry. CHIKV infection of Ae. aegypti and Ae. albopictus midguts and dissemination to heads was observed to be similar. A plaque assay performed with infected mosquito homogenates revealed that CHIKV replication dynamics was similar in Aedes sp. mosquitoes until 28 days post infection. VOPBA performed with mosquito midgut membrane proteins revealed that prohibitin could serve as a putative CHIKV receptor on Aedes mosquito midguts, whereas an absence of CHIKV binding protein/s on Culex quinquefasciatus midguts can partially explain the non-permissiveness of these mosquitoes to infection.


Assuntos
Aedes/virologia , Vírus Chikungunya/fisiologia , Culex/virologia , Mosquitos Vetores/virologia , Animais , Febre de Chikungunya/transmissão , Índia
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