1,119 research outputs found
A Truly Visible Vessel in an Endoscopic Submucosal Dissection Scare: Thinking Outside Recommendations
Glauber Critical Dynamics: Exact Solution of the Kinetic Gaussian Model
In this paper, we have exactly solved Glauber critical dynamics of the
Gaussian model on three dimensions. Of course, it is much easy to apply to low
dimensional case. The key steps are that we generalize the spin change
mechanism from Glauber's single-spin flipping to single-spin transition and
give a normalized version of the transition probability . We have also
investigated the dynamical critical exponent and found surprisingly that the
dynamical critical exponent is highly universal which refer to that for one-
two- and three-dimensions they have same value independent of spatial
dimensionality in contrast to static (equilibrium) critical exponents.Comment: 9 page
Solvable Kinetic Gaussian Model in External Field
In this paper, the single-spin transition dynamics is used to investigate the
kinetic Gaussian model in a periodic external field. We first derive the
fundamental dynamic equations, and then treat an isotropic d-dimensional
hypercubic lattice Gaussian spin system with Fourier's transformation method.
We obtain exactly the local magnetization and the equal-time pair correlation
function. The critical characteristics of the dynamical, the complex
susceptibility, and the dynamical response are discussed. The results show that
the time evolution of the dynamical quantities and the dynamical responses of
the system strongly depend on the frequency and the wave vector of the external
field.Comment: 11 page
Network-wide abnormalities explain memory variability in hippocampal amnesia
Patients with hippocampal amnesia play a central role in memory neuroscience but the neural underpinnings of amnesia are hotly debated. We hypothesized that focal hippocampal damage is associated with changes across the extended hippocampal system and that these, rather than hippocampal atrophy per se, would explain variability in memory between patients. We assessed this hypothesis in a uniquely large cohort of patients (n = 38) after autoimmune limbic encephalitis, a syndrome associated with focal structural hippocampal pathology. These patients showed impaired recall, recognition and maintenance of new information, and remote autobiographical amnesia. Besides hippocampal atrophy, we observed correlatively reduced thalamic and entorhinal cortical volume, resting-state inter-hippocampal connectivity and activity in posteromedial cortex. Associations of hippocampal volume with recall, recognition, and remote memory were fully mediated by wider network abnormalities, and were only direct in forgetting. Network abnormalities may explain the variability across studies of amnesia and speak to debates in memory neuroscience
Block-Diagonalization and f-electron Effects in Tight-Binding Theory
We extend a tight-binding total energy method to include f-electrons, and
apply it to the study of the structural and elastic properties of a range of
elements from Be to U. We find that the tight-binding parameters are as
accurate and transferable for f-electron systems as they are for d-electron
systems. In both cases we have found it essential to take great care in
constraining the fitting procedure by using a block-diagonalization procedure,
which we describe in detail.Comment: 9 pages, 6 figure
Loss of estrogen receptor beta expression correlates with shorter overall survival and lack of clinical response to chemotherapy in ovarian cancer patients
Background: Estrogen receptor beta (ERβ) belongs to a large family of nuclear receptors. Recent studies have suggested that ERβ in contrast to ERα might act as a tumour suppressor in ovarian cancer (OVCA). Materials and Methods: Expression of ERβ was detected by immunocytochemistry in 11 OVCA cell lines and by immunohistochemistry in 43 (41 FIGO stage III) OVCA specimens prepared before chemotherapy and 30 specimens from the same group after chemotherapy. Cisplatin sensitivity in the 11 cell lines was also analysed. Results: No significant correlations between cisplatin-sensitivity and expression of ERβ was found in the cell lines. In the cases which responded well to chemotherapy (complete response) ERβ expression at preliminary laparotomy (PL) was significantly higher (p=0.0004) than in those with progressive disease. Kaplan-Meier analysis revealed that the patients with higher ERβ expression (>30% of cells) at PL had an increased overall survival time and progression-free time (p=0.00161 and p=0.03255, respectively) than the patients with lower ERβ espression. Significantly shorter overall survival time characterized the cases with lower immunoreactivity score of ERβ expression at secondary cytoreduction (SCR) (p=0.00346). Conclusion: The loss of ERβ expression in ovarian tumours may be a feature of malignant transformation
The impact of silent vascular brain burden in cognitive impairment in Parkinson's disease
White matter hyperintensities (WMHs) detected by magnetic
resonance imaging (MRI) of the brain are associated with dementia and cognitive
impairment in the general population and in Alzheimer's disease. Their effect in
cognitive decline and dementia associated with Parkinson's disease (PD) is still
unclear. METHODS: We studied the relationship between WMHs and cognitive state in
111 patients with PD classified as cognitively normal (n = 39), with a mild
cognitive impairment (MCI) (n = 46) or dementia (n = 26), in a cross-sectional
and follow-up study. Cognitive state was evaluated with a comprehensive
neuropsychological battery, and WMHs were identified in FLAIR and T2-weighted
MRI. The burden of WMHs was rated using the Scheltens scale. RESULTS: No
differences in WMHs were found between the three groups in the cross-sectional
study. A negative correlation was observed between semantic fluency and the
subscore for WMHs in the frontal lobe. Of the 36 non-demented patients
re-evaluated after a mean follow-up of 30 months, three patients converted into
MCI and 5 into dementia. Progression of periventricular WMHs was associated with
an increased conversion to dementia. A marginal association between the increase
in total WMHs burden and worsening in the Mini Mental State Examination was
encountered. CONCLUSIONS: White matter hyperintensities do not influence the
cognitive status of patients with PD. Frontal WMHs have a negative impact on
semantic fluency. Brain vascular burden may have an effect on cognitive
impairment in patients with PD as WMHs increase overtime might increase the risk
of conversion to dementia. This finding needs further confirmation in larger
prospective studies
Pathologic tearfulness after limbic encephalitis: A novel disorder and its neural basis
Objective We investigated the nature and neural foundations of pathologic tearfulness in a uniquely large cohort of patients who had presented with autoimmune limbic encephalitis (aLE). Methods We recruited 38 patients (26 men, 12 women; median age 63.06 years; interquartile range [IQR] 16.06 years) in the postacute phase of aLE who completed questionnaires probing emotion regulation. All patients underwent structural/functional MRI postacutely, along with 67 age- and sex-matched healthy controls (40 men, 27 women; median age 64.70 years; IQR 19.87 years). We investigated correlations of questionnaire scores with demographic, clinical, neuropsychological, and brain imaging data across patients. We also compared patients diagnosed with pathologic tearfulness and those without, along with healthy controls, on gray matter volume, resting-state functional connectivity, and activity. Results Pathologic tearfulness was reported by 50% of the patients, while no patient reported pathologic laughing. It was not associated with depression, impulsiveness, memory impairment, executive dysfunction in the postacute phase, or amygdalar abnormalities in the acute phase. It correlated with changes in specific emotional brain networks: volume reduction in the right anterior hippocampus, left fusiform gyrus, and cerebellum, abnormal hippocampal resting-state functional connectivity with the posteromedial cortex and right middle frontal gyrus, and abnormal hemodynamic activity in the left fusiform gyrus, right inferior parietal lobule, and ventral pons. Conclusions Pathologic tearfulness is common following aLE, is not a manifestation of other neuropsychiatric features, and reflects abnormalities in networks of emotion regulation beyond the acute hippocampal focus. The condition, which may also be present in other neurologic disorders, provides novel insights into the neural basis of affective control and its dysfunction in disease
Equine infectious anemia affects the athletic performance of equines from the Brazilian Pantanal region.
The objective of this work was to evaluate the effects of equine infectious anemia (EIA) on the physical performance of equines from the Brazilian Pantanal region. A total of 16 males were evaluated, divided into two groups: 8 seronegative (G1) and 8 seropositive (G2) for EIA. Two graded exercise tests were carried out before (T1) and after (T2) 42 days of training. Heart rate, lactate concentration, distance covered, and hematocrit level were recorded. In both tests, G1 covered a greater distance. In T2, G2 had lower hematocrit levels and lower speeds reached at different lactate concentrations and heart rates. The athletic performance of the evaluated equines is affected by equine infectious anemia. O objetivo deste trabalho foi avaliar o efeito da anemia infecciosa equina (AIE) no desempenho físico de equinos da região do Pantanal brasileiro. Foram avaliados 16 machos, divididos em dois grupos: 8 soronegativos (G1) e 8 soropositivos (G2) para AIE. Dois testes de esforço progressivo foram realizados, antes (T1) e após (T2) 42 dias de treinamento. Foram registrados frequência cardíaca, concentração de lactato, distância percorrida e níveis de hematócrito. Em ambos os testes, o G1 percorreu uma distância maior. No T2, o G2 apresentou menores níveis de hematócrito e menor velocidade obtida a diferentes concentrações de lactato e frequências cardíacas. O desempenho atlético dos equídeos avaliados é afetado pela anemia infecciosa equina
Peso e rendimento de carcaça de cordeiros de diferentes grupos genéticos criados no semiárido brasileiro.
Resumo: Objetivou-se com esse estudo avaliar o peso e rendimento de carcaça de cordeiros de diferentes grupos genéticos Morada Nova x Morada Nova, Rabo Largo x Morada Nova e Santa Inês x Morada Nova. Foram utilizados 15 cordeiros machos, não castrados, com peso vivo médio inicial de 6,7 kg, em delineamento inteiramente casualizado, com cinco repetições em cada tratamento. Os animais foram mantidos em pastagem nativa da Caatinga e ao final da tarde suplementados com volumoso e ração concentrada a base de milho, farelo de soja e calcário, com água e sal mineral à vontade. Os animais foram abatidos ao atingirem oito meses de idade, com aproximadamente 25 kg de peso vivo. Após o abate, registraram-se os pesos e rendimentos da carcaça. Os dados foram submetidos a análise de variância e as médias comparadas pelo teste de Duncan pelo programa estatístico SAS®. Houve efeito do cruzamento para as variáveis peso vivo ao abate (PVA), peso da carcaça quente (PCQ), peso da carcaça fria (PCF) e rendimento biológico verdadeiro (RBV). Os cordeiros cruzas Rabo Largo x Morada Nova e Santa Inês x Morada apresentaram valores superiores para PVA, PCQ, PCF e RBV. Os grupos genéticos estudados proporcionam pesos de carcaça diferentes, o que denota que os mesmos podem ser usados de acordo com os objetivos dos produtores e do sistema de produção. [Weight and Yields of carcass of lambs of different genetic groups created in the Brazilian semiarid]. Abstract: The aim was to evaluate the weight and yield of carcass of lambs of different genetic groups: Morada Nova x Morada Nova, Rabo Largo x Morada Nova and Santa Ines x Morada Nova. Were used fifteen lambs, not castrated, with an average live weight of 6.7 kg, in a randomized design with five replicates in each treatment. The animals were kept on native pasture Caatinga and late afternoon supplemented with forage and ration concentrate based on corn, soybean meal and limestone, with access water and mineral salt ad libitum. The animals were slaughtered to reached eight months of age, with approximately 25 kg live weight. After slaughter, were recorded the weights and yield of carcass. Data were submitted to analysis of variance and means were compared by Duncan test by SAS® software. There was effect of crossing to the variables live weight at slaughter (LWS), hot carcass weight (HCW), cold carcass weight (CCW) and true biological yield (TBY). The crossbred lambs Rabo Largo x Morada Nova and Santa Ines x Morada Nova showed higher values for LWS, HCW, CCW and TBY. The genotypes utilized this research did provide weights different, which indicates that they may be used in accordance with the objectives of the producers and production system
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