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1.
An Acad Bras Cienc ; 95(suppl 1): e20220436, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37436230

RESUMO

To evaluate the effects in adults rats submitted of a low-protein, high-carbohydrate (LPHC; 6% protein, 74% carbohydrate) diet and reversion (R) to a balanced diet introduced after weaning. Research methods & procedures: Male rats weigting approximately 100g (30 to 32 d old) were treated with control (C; 17% protein, 63% carbohydrate) or LPHC diets for 120 days. The reverse group (R) was treated with the LPHC diet for 15 days, and changed to C diet for another 105 days. Results: The LPHC group showed an increase in serum fasting triglycerides (TAG). Serum adiponectin was increased only in the LPHC group. Lipoprotein lipase (LPL) activity was decreased in the extensor digitorum longus (EDL) and cardiac muscles. The adiponectin receptor 1 content is the same among groups in the cardiac muscle, but it is lower in the EDL muscle in the LPHC group. In animals from the R group, these parameters are the same as the LPHC group. Thus, the LPHC diet administered for a long period, it promotes an increase in TAG. It is possible that there is adiponectin resistance in the EDL muscle, due to the lower LPL activity. The reversal of the LPHC diet did not normalize these parameters.


Assuntos
Adiponectina , Carboidratos da Dieta , Ratos , Masculino , Animais , Ratos Wistar , Desmame , Carboidratos da Dieta/metabolismo , Dieta , Dieta com Restrição de Proteínas , Músculo Esquelético/metabolismo
2.
An Acad Bras Cienc ; 94(3): e20210902, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35857934

RESUMO

This study investigated whether increased food intake after 15 days of low-protein, high-carbohydrate (LPHC) and its normalization in the later period of development change the content of key proteins related to leptin or adiponectin signaling in the hypothalamus. Male rats were divided into five groups: Control groups received a control diet (17% protein, 63% carbohydrate) for 15 (C15) or 45 (C45) days; LPHC groups received an LPHC diet (6% protein, 74% carbohydrate) for 15 (LPHC15) or 45 (LPHC45) days; and Reverse group (R): received LPHC diet for 15 days followed by control diet for another 30 days. The LPHC15 group showed increased adiposity index, leptin level, and adiponectin level, as well as decreased the leptin receptor (ObRb) and pro-opiomelanocortin (POMC) content in the hypothalamus compared with the C15 group. LPHC diet for 45 days or diet reversion (R group) rescued these alterations, except the adiponectin level in LPHC45 rats, which was higher. In summary, LPHC diet reduced hypothalamic leptin action by diminishing ObRb and POMC levels, leading to hyperphagia and adiposity body. Medium-term administration of LPHC diet or reverting to control diet restored the levels of these proteins, thereby improving body lipid mass rearrangement in adulthood.


Assuntos
Leptina , Pró-Opiomelanocortina , Adiponectina , Animais , Carboidratos , Dieta com Restrição de Proteínas , Hiperfagia/etiologia , Hiperfagia/metabolismo , Leptina/metabolismo , Masculino , Obesidade/metabolismo , Pró-Opiomelanocortina/metabolismo , Ratos , Ratos Wistar
3.
Blood Cells Mol Dis ; 82: 102413, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32109669

RESUMO

Hereditary Xerocytosis (HX) is an autosomal dominantly inherited congenital hemolytic anemia associated with erythrocyte dehydration due to decreased intracellular potassium content resulting in increased mean corpuscular hemoglobin concentration. The affected members of HX families show compensated anemia with splenomegaly, hemosiderosis, and perinatal edema but are in large part transfusion independent. Functional studies show a link between mutations in mechanosensitive ion channel, encoded by PIEZO1 gene and the HX. We identified new PIEZO1 variants that are likely pathogenic in three phenotypically characterized multi-generational HX Brazilian families. Interestingly, one missense variant of the PIEZO1 gene identified, p.E2494V was associated in trans with the previously reported most frequent pathogenic duplication p.E2496ELE. The three-dimensional structure of the human protein modeled using structural coordinates of the mouse Piezo1 solved by cryo-electron microscopy (Cryo-ME) showed that the two identified variants, p.M2007L and p.T2014I, are localized to an important mechanosensitive transmembrane domain suggesting a conformational mechanism for altered channel's gating. The p.E2496ELE variant identified alters the extension of helix α1 bringing it much closer to the beam affecting the position of it structure at the end of the pore.


Assuntos
Anemia Hemolítica Congênita/genética , Hidropisia Fetal/genética , Canais Iônicos , Mutação de Sentido Incorreto , Adolescente , Adulto , Substituição de Aminoácidos , Animais , Criança , Feminino , Humanos , Recém-Nascido , Canais Iônicos/química , Canais Iônicos/genética , Masculino , Camundongos , Pessoa de Meia-Idade , Conformação Proteica em alfa-Hélice , Domínios Proteicos
4.
Phys Rev Lett ; 125(21): 217401, 2020 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-33274990

RESUMO

SrRuO_{3}, a ferromagnet with an approximately 160 K Curie temperature, exhibits a T^{2}-dependent dc resistivity below ≈30 K. Nevertheless, previous optical studies in the infrared and terahertz range show non-Drude dynamics at low temperatures, which seem to contradict Fermi-liquid predictions. In this work, we measure the low-frequency THz range response of thin films with residual resistivity ratios, ρ_{300K}/ρ_{4K}≈74. At temperatures below 30 K, we find both a sharp zero frequency mode which has a width narrower than k_{B}T/ℏ as well as a broader zero frequency Lorentzian that has at least an order of magnitude larger scattering. Both features have temperature dependences consistent with a Fermi liquid with the wider feature explicitly showing a T^{2} scaling. Above 30 K, there is a crossover to a regime described by a single Drude peak that we believe arises from strong interband electron-electron scattering. Such two channel Drude transport sheds light on reports of the violation of Matthiessen's rule and extreme sensitivity to disorder in metallic ruthenates.

5.
Phys Rev Lett ; 123(2): 027201, 2019 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-31386489

RESUMO

The quantum dimer magnet (QDM) is the canonical example of quantum magnetism. The QDM state consists of entangled nearest-neighbor spin dimers and often exhibits a field-induced triplon Bose-Einstein condensate (BEC) phase. We report on a new QDM in the strongly spin-orbit coupled, distorted honeycomb-lattice material Yb_{2}Si_{2}O_{7}. Our single crystal neutron scattering, specific heat, and ultrasound velocity measurements reveal a gapped singlet ground state at zero field with sharp, dispersive excitations. We find a field-induced magnetically ordered phase reminiscent of a BEC phase, with exceptionally low critical fields of H_{c1}∼0.4 and H_{c2}∼1.4 T. Using inelastic neutron scattering in an applied magnetic field we observe a Goldstone mode (gapless to within δE=0.037 meV) that persists throughout the entire field-induced magnetically ordered phase, suggestive of the spontaneous breaking of U(1) symmetry expected for a triplon BEC. However, in contrast to other well-known cases of this phase, the high-field (µ_{0}H≥1.2 T) part of the phase diagram in Yb_{2}Si_{2}O_{7} is interrupted by an unusual regime signaled by a change in the field dependence of the ultrasound velocity and magnetization, as well as the disappearance of a sharp anomaly in the specific heat. These measurements raise the question of how anisotropy in strongly spin-orbit coupled materials modifies the field induced phases of QDMs.

6.
Colorectal Dis ; 21(7): 775-781, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30848537

RESUMO

AIM: Studies addressing the benefit of early intervention are prone to lead-time bias, which results in an artificial improvement in cancer-specific mortality. We have previously compared the age at death for patients with colorectal cancer presenting on an emergency or elective basis. In this study, we aimed to repeat the analysis with a minimum follow-up of 10 years. METHOD: A nonscreen-detected cohort of patients presenting with colorectal cancer to three Lanarkshire Hospitals between 2000 and 2006 were entered into a prospective database, with analysis performed on 28 November 2016. The following data were collected: age at death, presentation type (emergency/elective), operative intent (palliative/curative) and Dukes stage. Results are presented as [mean (95% confidence intervals)]. Statistical analysis was undertaken using Student's t-test and multivariate analysis performed using Cox proportional hazard models. RESULTS: One thousand six hundred and thirty-six patients were identified. Elective patients presented younger than emergency patients [67.9 (67.3-68.5) vs 70.9 (69.6-72.2) years; P < 0.0001]. Overall mortality was 71.1% at time of analysis; no difference was seen in the mean age at death between emergency and elective presentation [73.5 (72.4-74.8) vs 73.6 (72.3-74.9) years; P = 0.841]. CONCLUSION: Current early detection strategies to diagnose colorectal cancer may improve cancer-specific survival by increasing lead-time bias. However, in our cohort of symptomatic patients, treatment on an elective or emergency basis does not influence overall survival. These data suggest that in selected patients, particularly where there is comorbidity, it may be reasonable to adopt a more expectant approach to investigate and treat colorectal symptoms.


Assuntos
Fatores Etários , Neoplasias Colorretais/mortalidade , Procedimentos Cirúrgicos Eletivos/mortalidade , Tratamento de Emergência/mortalidade , Fatores de Tempo , Idoso , Viés , Neoplasias Colorretais/patologia , Neoplasias Colorretais/cirurgia , Bases de Dados Factuais , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Modelos de Riscos Proporcionais , Estudos Prospectivos
7.
An Acad Bras Cienc ; 91(1): e20180314, 2019 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-30916157

RESUMO

Our objective was to establish a diabetes mellitus type 2 (DM2) model in rats using a high-fat diet and streptozotocin (HF-STZ). Male Wistar rats (240-250g) were divided into a control group (commercial feed), and HF-STZ group, (66.5%-commercial feed, 13.5%-lard, and 20%-sugar). STZ (40mg/kg i.p.) or vehicle was administered on the 13th day. An oral glucose tolerance test (OGTT) was performed (2.5mg of glucose/kg v.o.) on both groups. After 39 days of treatment, blood and tissue samples were collected for analyses. The weight gain after STZ administration was lower in the HF-STZ group than in the control group with reductions in muscle mass and adipose tissue. The HF-STZ group showed hyperglycemia after STZ administration (glucose on day 39: HF-STZ: 499 ± 60; control: 134 ± 9mg/dL). Serum glucagon was 23% lower, and insulin levels were unaltered. The HOMA index was 4-times higher in the HF-STZ. The HF-STZ group showed increased post-prandial (330%) and fasting (125%) triglycerides, and while glycogen content in the liver and muscles decreased (70-80%). The area under the curve (OGTT) was 282% higher in the HF-STZ group. The combination of high-fat diet with STZ (i.p) generated rats with hyperglycemia associated with hypertriglyceridemia and introduced many other alterations present in human DM2.


Assuntos
Diabetes Mellitus Experimental/patologia , Diabetes Mellitus Tipo 2/patologia , Dieta Hiperlipídica , Resistência à Insulina/fisiologia , Animais , Glicemia/metabolismo , Peso Corporal , Diabetes Mellitus Experimental/induzido quimicamente , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Feminino , Teste de Tolerância a Glucose , Insulina/metabolismo , Lipídeos/sangue , Masculino , Gravidez , Ratos Wistar , Estreptozocina/administração & dosagem , Aumento de Peso
8.
An Acad Bras Cienc ; 91(2): e20180452, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31269107

RESUMO

The aim of this study was investigate the effects of a low-protein, high-carbohydrate (LPHC) diet introduced to rats soon after weaning. The animals were distributed in the following groups: LPHC45: fed an LPHC diet (6%-protein, 74%-carbohydrate) for 45 days; C45: fed a control (C) diet (17%-protein, 63%-carbohydrate) for 45 days; R (Reverse): fed with LPHC for 15 days followed by C diet for 30 days. The LPHC45 group showed alterations in the energetic balance with an increase in brown adipose tissue, and in glucose tolerance, and lower final body weight, muscle mass and total protein in blood when compared with C45 group. The HOMA-IR index was similar between LPHC45 and C45 groups, but this parameter was lower in LPHC45 compared with R groups. Serum adiponectin was higher in LPHC45 group than C45 and R groups. The R group presented higher fed insulin than C45 and LPHC45 and higher T4 compared with C45 group. Total cholesterol in R group was higher when compared with LPHC45 group. Thus, the data show that the change of the diet LPHC for a balanced diet led to different metabolic evolution and suggest that the different response can be due to different levels of adiponectin.


Assuntos
Adiponectina/sangue , Glicemia/metabolismo , Dieta com Restrição de Proteínas , Carboidratos da Dieta/metabolismo , Homeostase/fisiologia , Animais , Masculino , Ratos , Ratos Wistar
9.
Gut ; 67(2): 299-306, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-27789658

RESUMO

OBJECTIVES: Colorectal polyp cancers present clinicians with a treatment dilemma. Decisions regarding whether to offer segmental resection or endoscopic surveillance are often taken without reference to good quality evidence. The aim of this study was to develop a treatment algorithm for patients with screen-detected polyp cancers. DESIGN: This national cohort study included all patients with a polyp cancer identified through the Scottish Bowel Screening Programme between 2000 and 2012. Multivariate regression analysis was used to assess the impact of clinical, endoscopic and pathological variables on the rate of adverse events (residual tumour in patients undergoing segmental resection or cancer-related death or disease recurrence in any patient). These data were used to develop a clinically relevant treatment algorithm. RESULTS: 485 patients with polyp cancers were included. 186/485 (38%) underwent segmental resection and residual tumour was identified in 41/186 (22%). The only factor associated with an increased risk of residual tumour in the bowel wall was incomplete excision of the original polyp (OR 5.61, p=0.001), while only lymphovascular invasion was associated with an increased risk of lymph node metastases (OR 5.95, p=0.002). When patients undergoing segmental resection or endoscopic surveillance were considered together, the risk of adverse events was significantly higher in patients with incomplete excision (OR 10.23, p<0.001) or lymphovascular invasion (OR 2.65, p=0.023). CONCLUSION: A policy of surveillance is adequate for the majority of patients with screen-detected colorectal polyp cancers. Consideration of segmental resection should be reserved for those with incomplete excision or evidence of lymphovascular invasion.


Assuntos
Algoritmos , Pólipos do Colo/patologia , Pólipos do Colo/cirurgia , Neoplasias Colorretais/patologia , Neoplasias Colorretais/cirurgia , Recidiva Local de Neoplasia/diagnóstico , Conduta Expectante , Idoso , Vasos Sanguíneos/patologia , Colectomia , Colonoscopia , Intervalo Livre de Doença , Detecção Precoce de Câncer , Medicina Baseada em Evidências , Feminino , Humanos , Metástase Linfática , Vasos Linfáticos/patologia , Masculino , Invasividade Neoplásica , Neoplasia Residual , Fatores de Risco , Escócia , Taxa de Sobrevida
10.
Nanotechnology ; 26(26): 265701, 2015 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-26057323

RESUMO

Scanning thermal microscopy has been implemented in a cross-sectional geometry, and its application for quantitative, nanoscale analysis of thermal conductivity is demonstrated in studies of an ErAs/GaAs nanocomposite superlattice. Spurious measurement effects, attributable to local thermal transport through air, were observed near large step edges, but could be eliminated by thermocompression bonding to an additional structure. Using this approach, bonding of an ErAs/GaAs superlattice grown on GaAs to a silicon-on-insulator wafer enabled thermal signals to be obtained simultaneously from Si, SiO2, GaAs, and ErAs/GaAs superlattice. When combined with numerical modeling, the thermal conductivity of the ErAs/GaAs superlattice measured using this approach was 11 ± 4 W m(-1) K(-1).

11.
Can J Physiol Pharmacol ; 92(6): 460-6, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24830680

RESUMO

The our objective was to investigate the adaptations induced by a low-protein, high-carbohydrate (LPHC) diet in growing rats, which by comparison with the rats fed a control (C) diet at displayed lower fasting glycemia and similar fasting insulinemia, despite impairment in insulin signaling in adipose tissues. In the insulin tolerance test the LPHC rats showed higher rates of glucose disappearance (30%) and higher tolerance to overload of glucose than C rats. The glucose uptake by the soleus muscle, evaluated in vivo by administration of 2-deoxy-[(14)C]glucose, increased by 81%. The phosphoenolpyruvate carboxykinase content and the incorporation of [1-(14)C]pyruvate into glucose was also higher in the slices of liver from the LPHC rats than in those from C rats. The LPHC rats showed increases in l-lactate as well as in other gluconeogenic precursors in the blood. These rats also had a higher hepatic production of glucose, evaluated by in situ perfusion. The data obtained indicate that the main substrates for gluconeogenesis in the LPHC rats are l-lactate and glycerol. Thus, we concluded that the fasting glycemia in the LPHC animals was maintained mainly by increases in the hepatic gluconeogenesis from glycerol and l-lactate, compensating, at least in part, for the higher glucose uptake by the tissues.


Assuntos
Glicemia/metabolismo , Dieta com Restrição de Proteínas , Carboidratos da Dieta/administração & dosagem , Jejum/sangue , Gluconeogênese , Glucose/biossíntese , Fígado/metabolismo , Tecido Adiposo/metabolismo , Animais , Teste de Tolerância a Glucose , Glicerol/sangue , Insulina/sangue , Ácido Láctico/sangue , Masculino , Músculo Esquelético/metabolismo , Fosfoenolpiruvato Carboxiquinase (GTP)/metabolismo , Ratos
12.
Sci Total Environ ; 926: 171721, 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38494028

RESUMO

Black Carbon (BC), formed by incomplete combustion, absorbs solar radiation and heats the atmosphere. We investigated the enhancement in optical absorption of BC due to coatings of water-soluble (WS) species in the polluted South Asian atmosphere. The BC Mass Absorption Cross-section (MAC; 678 nm) was estimated before and after removal of the WS components. Wintertime samples were collected from three South Asian receptor observatories intercepting large-footprint outflow: Bangladesh Climate Observatory Bhola (BCOB; integrating outflow of the Indo-Gangetic Plain), Maldives Climate Observatories at Hanimaadhoo (MCOH) and at Gan (MCOG), both reflecting outflow from the South Asian region. The ambient MAC observed at BCOB, MCOH and MCOG were 4.2 ± 1.4, 7.9 ± 1.9 and 7.1 ± 1.5 m2 g-1, respectively. The average enhancement of the BC MAC due to WS coatings (i.e., ws-EMAC) was identical at all three sites (1.6 ± 0.5) indicating that the anthropogenic aerosols had already evolved to a fully coated morphology at BCOB and/or that subsequent aging involved two compensating evolution processes of the coating. Inspecting the key coating component sulfate; the sulfate-to-BC ratio increased threefold when transitioning from BCOB to MCOH and by about 1.5 times from BCOB to MCOG. Conversely, both WS organic carbon (WSOC)/BC and water-insoluble OC (WIOC)/BC ratios declined with distance: WSOC/BC diminished by 84 % from BCOB to MCOH and by 80 % from BCOB to MCOG, while WIOC/BC dropped by about 63 % and 59 %, respectively. Such declines in WSOC and WIOC reflect a combination of photochemical oxidation and more efficient washout of OC compared to BC. The observed changes in the SO42-/BC and WSOC/BC ratios across South Asia highlight the significant impact of aerosol composition on the optical properties of Black Carbon (BC). These findings emphasize the need for detailed studies on aerosol composition to improve climate models and develop effective strategies for reducing the impact of anthropogenic aerosols on the climate.

13.
Front Endocrinol (Lausanne) ; 14: 1201547, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37766684

RESUMO

Introduction: The pharmacological target for progesterone, different progestins, and Selective Progesterone Receptor Modulators (SPRMs) is the nuclear progesterone receptor (PR). EC313 is a new member of a subgroup of SPRMs, mesoprogestins, which combine especially PR- agonistic and PR-antagonistic activities in one molecule. Methods: The suitable in vivo-model for the differentiation of SPRMs from the subgroup of mesoprogestins is the estrogen-primed juvenile rabbit endometrium assay (McPhail Assay). Remarkably, in contrast to other well-known SPRMs with no agonistic effects in this test, EC313 shows clear partial PR-agonistic effects that are higher than that of the well-known mesoprogestin Asoprisnil which already demonstrated remarkable clinical effectiveness for the treatment of uterine fibroids and endometriosis. The findings from the guinea pig studies presented here can be the impetus for further preclinical development of EC313. This model shows the same features for the termination of pregnancy by antiprogestins such as Mifepristone and Ulipristal acetate (UPA) in humans. Moreover, it is possible to distinguish between progestational and anti-progestational activities in the same experiment. Results: The EC313 treatment reveals PR dominance in the genital tract and inhibits unopposed estrogenic effects. In very high doses (30.0 mg/animal/day subcutaneously (s.c.)) given twice on pregnancy days 43 and 44, no premature labor was induced (in contrast to UPA, dosed at 10.0 and 30. mg/animal/day s.c.). The anti-ovulatory activity of EC313 exceeds that of Ulipristal acetate or Mifepristone. EC313 binds to the steroid receptors in vitro with a similar affinity as the natural ligand progesterone. At the glucocorticoid receptor (GR) EC313 acts as a weak inhibitor. Minor activities at the human androgen receptor (AR) and mineralocorticoid receptor (MR) are considered negligible. No binding to the estradiol receptor was detected. In contrast to some in vitro-receptor findings, estrogenic, anti-estrogenic, androgenic, anti-androgenic, glucocorticoid, and anti-glucocorticoid actions were absent in vivo. The tissue selectivity of EC313 was demonstrated previously by reducing the growth and proliferation of uterine fibroids in animal models (lowest effective dosage 0.1 mg/kg/day s.c.).. As shown in this article, the anti-fibroid activity of EC313 was confirmed with a 10 times lower dosage (0.01 mg/kg/day s.c.). It was also shown that EC313 reduces the growth of endometriotic lesions in a human xenograft immune-deficient (NOD-SCID) mice model with a comparatively very low dosage range. In the aforementioned EC313 activity model, UPA was tested as the reference compound, the clinical effectiveness of which has already been demonstrated. Discussion: For an explanation of these findings, the possibility is discussed that the mixed agonistic/antagonistic feature of EC313 is tissue target-specific based on its super-additive synergism characteristic for active bifunctional agents. In conclusion, the specific pharmacodynamic profile of this compound opens the possibility for the development of a drug with a distinct pharmaco-endocrinological profile against uterine fibroids, endometriosis, and other PR-dependent gynecological diseases.


Assuntos
Endometriose , Receptores de Progesterona , Camundongos , Feminino , Gravidez , Humanos , Animais , Cobaias , Coelhos , Camundongos Endogâmicos NOD , Camundongos SCID , Progesterona , Mifepristona/farmacologia , Progestinas , Estrogênios
14.
NPJ Clim Atmos Sci ; 6(1): 39, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37252186

RESUMO

Anthropogenic aerosols mask the climate warming caused by greenhouse gases (GHGs). In the absence of observational constraints, large uncertainties plague the estimates of this masking effect. Here we used the abrupt reduction in anthropogenic emissions observed during the COVID-19 societal slow-down to characterize the aerosol masking effect over South Asia. During this period, the aerosol loading decreased substantially and our observations reveal that the magnitude of this aerosol demasking corresponds to nearly three-fourths of the CO2-induced radiative forcing over South Asia. Concurrent measurements over the northern Indian Ocean unveiled a ~7% increase in the earth's surface-reaching solar radiation (surface brightening). Aerosol-induced atmospheric solar heating decreased by ~0.4 K d-1. Our results reveal that under clear sky conditions, anthropogenic emissions over South Asia lead to nearly 1.4 W m-2 heating at the top of the atmosphere during the period March-May. A complete phase-out of today's fossil fuel combustion to zero-emission renewables would result in rapid aerosol demasking, while the GHGs linger on.

15.
N Engl J Med ; 361(27): 2628-36, 2009 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-20042754

RESUMO

BACKGROUND: In April 2009, an outbreak of novel swine-origin influenza A (2009 H1N1 influenza) occurred at a high school in Queens, New York. We describe the outbreak and characterize the clinical and epidemiologic aspects of this novel virus. METHODS: The New York City Department of Health and Mental Hygiene characterized the outbreak through laboratory confirmation of the presence of the 2009 H1N1 virus in nasopharyngeal and oropharyngeal specimens and through information obtained from an online survey. Detailed information on exposure and the onset of symptoms was used to estimate the incubation period, generation time, and within-school reproductive number associated with 2009 H1N1 influenza, with the use of established techniques. RESULTS: From April 24 through May 8, infection with the 2009 H1N1 virus was confirmed in 124 high-school students and employees. In responses to the online questionnaire, more than 800 students and employees (35% of student respondents and 10% of employee respondents) reported having an influenza-like illness during this period. No persons with confirmed 2009 H1N1 influenza or with influenza-like illness had severe symptoms. A linkage with travel to Mexico was identified. The estimated median incubation period for confirmed 2009 H1N1 influenza was 1.4 days (95% confidence interval [CI], 1.0 to 1.8), with symptoms developing in 95% of cases by 2.2 days (95% CI, 1.7 to 2.6). The estimated median generation time was 2.7 days (95% CI, 2.0 to 3.5). We estimate that the within-school reproductive number was 3.3. CONCLUSIONS: The findings from this investigation suggest that 2009 H1N1 influenza in the high school was widespread but did not cause severe illness. The reasons for the rapid and extensive spread of influenza-like illnesses are unknown. The natural history and transmission of the 2009 H1N1 influenza virus appear to be similar to those of previously observed circulating pandemic and interpandemic influenza viruses.


Assuntos
Surtos de Doenças , Vírus da Influenza A Subtipo H1N1 , Influenza Humana/epidemiologia , Adolescente , Adulto , Transmissão de Doença Infecciosa/estatística & dados numéricos , Feminino , Inquéritos Epidemiológicos , Humanos , Vírus da Influenza A Subtipo H1N1/genética , Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Influenza Humana/complicações , Influenza Humana/transmissão , Masculino , Pessoa de Meia-Idade , Cidade de Nova Iorque/epidemiologia , Reação em Cadeia da Polimerase , Instituições Acadêmicas , Adulto Jovem
16.
Public Health ; 126(3): 202-205, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22325615

RESUMO

With ageing populations, increased economic prosperity and the ensuing lifestyle changes, there has been a dramatic increase in the burden of chronic non-communicable diseases in countries of the developing world. The distribution of risk factors for chronic diseases among populations in developing countries has traditionally been very different from that in their Western counterparts, thus resulting in considerable variation in disease distribution in these settings. However, with the increase in globalization along with rapid advancements in technology, many developing countries are now faced with the challenge of a dual disease burden, battling existing communicable infectious diseases as well as the emerging epidemic of non-communicable chronic diseases. This paper highlights the need for multiple cohort studies on chronic diseases around the world, and explores some of the challenges in establishing and maintaining these studies in resource-constrained settings.


Assuntos
Doença Crônica/epidemiologia , Estudos de Coortes , Saúde Global , Projetos de Pesquisa , Epidemias , Humanos , Internacionalidade
17.
Public Health ; 126(3): 223-226, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22326603

RESUMO

The countries in South-east Asia have wide disparities in socio-economic and health indicators. This region accounts for almost one-third of global mortality in neonates and children under 5 years of age, and many countries in the region are unlikely to attain Millennium Development Goal 4. Over the past decade, several countries have initiated innovative projects with the aim of improving child health. This paper examines the innovations in neonatal health in four countries--Bangladesh, India, Sri Lanka and Thailand--and analyses the extent to which these have been successful in meeting their goals. This case study will inform national governments and donor agencies wishing to scale up or modify existing neonatal health interventions.


Assuntos
Serviços de Saúde da Criança/tendências , Mortalidade da Criança/tendências , Mortalidade Infantil/tendências , Sudeste Asiático/epidemiologia , Criança , Pré-Escolar , Humanos , Lactente , Recém-Nascido , Inovação Organizacional
18.
Microbiome ; 10(1): 71, 2022 05 06.
Artigo em Inglês | MEDLINE | ID: mdl-35524279

RESUMO

Although the rapid spread of antimicrobial resistance (AMR), particularly in relation to clinical settings, is causing concern in many regions of the globe, remote, extreme environments, such as Antarctica, are thought to be relatively free from the negative impact of human activities. In fact, Antarctica is often perceived as the last pristine continent on Earth. Such remote regions, which are assumed to have very low levels of AMR due to limited human activity, represent potential model environments to understand the mechanisms and interactions underpinning the early stages of evolution, de novo development, acquisition and transmission of AMR. Antarctica, with its defined zones of human colonisation (centred around scientific research stations) and large populations of migratory birds and animals, also has great potential with regard to mapping and understanding the spread of early-stage zoonotic interactions. However, to date, studies of AMR in Antarctica are limited. Here, we survey the current literature focussing on the following: i) Dissection of human-introduced AMR versus naturally occurring AMR, based on the premise that multiple drug resistance and resistance to synthetic antibiotics not yet found in nature are the results of human contamination ii) The potential role of endemic wildlife in AMR spread There is clear evidence for greater concentrations of AMR around research stations, and although data show reverse zoonosis of the characteristic human gut bacteria to endemic wildlife, AMR within birds and seals appears to be very low, albeit on limited samplings. Furthermore, areas where there is little, to no, human activity still appear to be free from anthropogenically introduced AMR. However, a comprehensive assessment of AMR levels in Antarctica is virtually impossible on current data due to the wide variation in reporting standards and methodologies used and poor geographical coverage. Thus, future studies should engage directly with policymakers to promote the implementation of continent-wide AMR reporting standards. The development of such standards alongside a centralised reporting system would provide baseline data to feedback directly into wastewater treatment policies for the Antarctic Treaty Area to help preserve this relatively pristine environment. Video Abstract.


Assuntos
Antibacterianos , Farmacorresistência Bacteriana , Animais , Animais Selvagens , Regiões Antárticas , Antibacterianos/farmacologia , Bactérias , Aves
19.
J Phys Condens Matter ; 33(2): 025802, 2021 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-33055379

RESUMO

We explored the electronic and magnetic properties of the lanthanide double perovskite Dy2FeCoO6 by combining magnetization, Raman and Mössbauer spectroscopy and neutron diffraction along with density functional theory (DFT) calculations. Our magnetization measurements revealed two magnetic phase transitions in Dy2FeCoO6. First, a paramagnetic to antiferromagnetic transition at T N = 248 K and subsequently, a spin reorientation transition at T SR = 86 K. In addition, a field-induced magnetic phase transition with a critical field of H c ≈ 20 kOe is seen at 2 K. Neutron diffraction data suggested cation-disordered orthorhombic structure for Dy2FeCoO6 in Pnma space group which is supported by Raman scattering results. The magnetic structures ascertained through representational analysis indicate that at T N, a paramagnetic state is transformed to Γ5(Cx, Fy, Az) antiferromagnetic structure while, at T SR, Fe/Co moments undergo a spin reorientation to Γ3(Gx, Ay, Fz). The refined magnetic moment of (Fe/Co) is 1.47(4) µ B at 7 K. The antiferromagnetic structure found experimentally is supported through the DFT calculations which predict an insulating electronic state in Dy2FeCoO6.

20.
Nat Commun ; 12(1): 59, 2021 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-33397949

RESUMO

Superconductivity is among the most fascinating and well-studied quantum states of matter. Despite over 100 years of research, a detailed understanding of how features of the normal-state electronic structure determine superconducting properties has remained elusive. For instance, the ability to deterministically enhance the superconducting transition temperature by design, rather than by serendipity, has been a long sought-after goal in condensed matter physics and materials science, but achieving this objective may require new tools, techniques and approaches. Here, we report the transmutation of a normal metal into a superconductor through the application of epitaxial strain. We demonstrate that synthesizing RuO2 thin films on (110)-oriented TiO2 substrates enhances the density of states near the Fermi level, which stabilizes superconductivity under strain, and suggests that a promising strategy to create new transition-metal superconductors is to apply judiciously chosen anisotropic strains that redistribute carriers within the low-energy manifold of d orbitals.

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