2,005 research outputs found
Defect-Seeded Atomic Layer Deposition of Metal Oxides on the Basal Plane of 2D Layered Materials
Atomic layer deposition (ALD) on mechanically exfoliated 2D layered materials spontaneously produces network patterns of metal oxide nanoparticles in triangular and linear deposits on the basal surface. The network patterns formed under a range of ALD conditions and were independent of the orientation of the substrate in the ALD reactor. The patterns were produced on MoS2 or HOPG when either tetrakis(dimethylamido)titanium or bis(ethylcyclopentadienyl)manganese were used as precursors, suggesting that the phenomenon is general for 2D materials. Transmission electron microscopy revealed the presence, prior to deposition, of dislocation networks along the basal plane of mechanically exfoliated 2D flakes, indicating that periodical basal plane defects related to disruptions in the van der Waals stacking of layers, such as perfect line dislocations and triangular extended stacking faults networks, introduce a surface reactivity landscape that leads to the emergence of patterned deposition
Studies on the clinical significance of nonesterified and total cholesterol in urine
Gas-liquid chromatographic determinations of nonesterified and total urinary cholesterol were performed in 137 normals, 264 patients with various internal diseases without evidence of neoplasias or diseases of the kidney or urinary tract, 497 patients with malignancies and 236 patients with diseases of the kidney, urinary tract infections or prostatic adenoma with residual urine. A normal range (mean±2 SD) of 0.2–2.2 mg/24 hours nonesterified cholesterol (NEC) and of 0.3–3.0 mg/24 hours total cholesterol (TC) was calculated.
Values of urinary cholesterol excretion were independent of age and sex and did not correlate with cholesterol levels in plasma. Patients with various internal diseases, without evidence of neoplasias nor diseases of the kidney or obstruction of the urinary tract, showed normal urinary cholesterol excretions, as did patients with infections of the urinary tract.
However, elevated urinary cholesterol was found in patients with diseases of the kidney or urinary tract obstruction (prostatic adenoma with residual urine), malignant diseases of the urogenital tract and metastasing carcinoma of the breast. In patients with other malignant diseases urinary cholesterol was usually normal.
Lesions of the urothelial cell membranes are considered to be the most likely cause of urinary cholesterol hyperexcretion. The clinical value of urinary cholesterol determinations as a possible screening test for urogenital carcinomas in unselected populations is limited by lacking specificity, expensive methodology and low prevalence of the mentioned carcinomas, although elevated urinary cholesterol excretions have been observed in early clinical stages of urogenital cancers
Prevalence and Risk Factors of Mastitis among Dairy Buffaloes from the Departments of Antioquia and Córdoba, Colombia
Background: Mastitis is the most common disease among dairy buffaloes worldwide, and it significantly affects the economic profitability of buffalo farms as well as animal welfare and public health.
Methods: This study was conducted between 2018 and 2019 at the Colombian departments of Antioquia and Córdoba, where 41% of the country’s total buffalo population is concentrated. Overall, 1,018 dairy buffaloes, including 603 in Antioquia and 415 in Córdoba, distributed among 11 farms, were assessed in the study. These animals were evaluated using the California mastitis test (CMT) and somatic cell count (SCC) to determine the presence of subclinical mastitis (SM). They were considered positive for SM when the results of CMT were higher than traces and SCC was >200,000 cells/mL.
Results: The total prevalence of the disease was 7.9%, and microbiological culture was performed on the samples obtained from the SM-positive animals. The main isolated bacterium was coagulase-negative Staphylococcus. Furthermore, risk factors affecting milking routine, hygiene, and farm facilities were determined. Manual milking, milking in the barn, non-disinfection of milkers' hands, etc., were identified as risk factors for the disease.
Conclusion: To the best of our knowledge, this is the first large-scale study of mastitis among buffaloes in Colombia
When is Affect Variability Bad for Health? The Association between Affect Variability and Immune Response to the Influenza Vaccination
Objectives—This study addresses methodological and theoretical questions about the association between affect and physical health. Specifically, we examine the role of affect variability and its interaction with mean levels of affect to predict antibody (Ab) levels in response to an influenza vaccination.
Methods—Participants (N = 83) received the vaccination and completed daily diary measures of affect four times a day for 13 days. At one and four months post-vaccination, blood was collected from the participants to assess Ab levels.
Results—Findings indicate that affect variability and its interaction with mean levels of affect predict an individual’s immune response. Those high in mean positive affect (PA) who had more PA variability were more likely to have a lower Ab response in comparison to those who had high mean PA and less PA variability. Although it did not interact with mean negative affect (NA), NA variability on its own was associated with Ab response, whereby those with less NA variability mounted a more robust immune response.
Conclusion—Affect variability is related to immune response to an influenza vaccination and, in some cases, interacts with mean levels of affect. These oscillations in affective experiences are critical to consider in order to unpack the intricacies of how affect influences health. These findings suggest that future researchers should consider the important role of affect variability on physical health-relevant outcomes as well as examine the moderating effect of mean affect levels
Transition and Gap Models of Forest Dynamics
Article discussing transition and gap models of forest dynamics
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Misremembering pain: A memory blindness approach to adding a better end.
How people remember feeling in the past informs future decisions; however, memory for past emotion is subject to a number of biases. Previous research on choice blindness has shown that people often fail to notice when they are exposed to misinformation about their own decisions, preferences, and memories. This type of misinformation can influence how they later remember past events. In the present study, we examined the memory blindness effect in a new domain: memory for pain. Participants (N = 269) underwent a cold-pressor task and rated how much pain, distress, and positive and negative affect they had experienced. Later, participants were shown their pain ratings and asked to explain them. Some of the participants were shown lower pain ratings than they had actually made. In a second session, participants recalled how painful the task had been and how much distress and positive and negative affect they remembered experiencing. The results indicated that the majority of participants who were exposed to misinformation failed to detect the manipulation, and subsequently remembered the task as being less painful. The participants in the misinformation condition were not overall more willing to repeat the study tasks, but the participants who recalled less distress, less negative affect, and more positive affect were more willing to repeat the study tasks again in a future experiment. These results demonstrate the malleability of memory for painful experiences and that willingness to repeat aversive experiences may depend more on memory for affective reactions to the original experience than on memory for the physical pain itself
Environment-driven reactivity of H2 on PdRu surface alloys
The dissociative adsorption of molecular hydrogen on PdxRu1−x/Ru(0001) (0 ≤ x ≤ 1) has been investigated by means of He atom scattering, Density Functional Theory and quasi-classical trajectory calculations. Regardless of their surroundings, Pd atoms in the alloy are always less reactive than Ru ones. However, the reactivity of Ru atoms is enhanced by the presence of nearest neighbor Pd atoms. This environment-dependent reactivity of the Ru atoms in the alloy provides a sound explanation for the striking step-like dependence of the initial reactive sticking probability as a function of the Pd concentration observed in experiments. Moreover, we show that these environment-dependent effects on the reactivity of H2 on single atoms allow one to get around the usual constraint imposed by the Brønsted–Evans–Polanyi relationship between the reaction barrier and chemisorption energy.Fil: Ramos Acevedo, Maximiliano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Física de Rosario (i); Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Exactas, Ingeniería y Agrimensura; ArgentinaFil: Minniti, M.. Universidad Autónoma de Madrid; EspañaFil: Díaz, C.. Universidad Autónoma de Madrid; EspañaFil: Farias, D.. Universidad Autónoma de Madrid; EspañaFil: Miranda, R.. Universidad Autónoma de Madrid; España. Instituto Madrileño de Estudios Avanzados en Nanociencia; EspañaFil: Martín, F.. Universidad Autónoma de Madrid; España. Instituto Madrileño de Estudios Avanzados en Nanociencia; EspañaFil: Martinez, Alejandra Elisa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Física de Rosario (i); Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Exactas, Ingeniería y Agrimensura; ArgentinaFil: Busnengo, Heriberto Fabio. Universidad Nacional de Rosario. Facultad de Ciencias Exactas, Ingeniería y Agrimensura; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Física de Rosario (i); Argentin
Canonical Notch signaling is required for bone morphogenetic protein‐mediated human osteoblast differentiation
Osteoblast differentiation of bone marrow‐derived human mesenchymal stem cells (hMSC) can be induced by stimulation with canonical Notch ligand, Jagged1, or bone morphogenetic proteins (BMPs). However, it remains elusive how these two pathways lead to the same phenotypic outcome. Since Runx2 is regarded as a master regulator of osteoblastic differentiation, we targeted Runx2 with siRNA in hMSC. This abrogated both Jagged1 and BMP2 mediated osteoblastic differentiation, confirming the fundamental role for Runx2. However, while BMP stimulation increased Runx2 and downstream Osterix protein expression, Jagged1 treatment failed to upregulate either, suggesting that canonical Notch signals require basal Runx2 expression. To fully understand the transcriptomic profile of differentiating osteoblasts, RNA sequencing was performed in cells stimulated with BMP2 or Jagged1. There was common upregulation of ALPL and extracellular matrix genes, such as ACAN, HAS3, MCAM, and OLFML2B. Intriguingly, genes encoding components of Notch signaling (JAG1, HEY2, and HES4) were among the top 10 genes upregulated by both stimuli. Indeed, ALPL expression occurred concurrently with Notch activation and inhibiting Notch activity for up to 24 hours after BMP administration with DAPT (a gamma secretase inhibitor) completely abrogated hMSC osteoblastogenesis. Concordantly, RBPJ (recombination signal binding protein for immunoglobulin kappa J region, a critical downstream modulator of Notch signals) binding could be demonstrated within the ALPL and SP7 promoters. As such, siRNA‐mediated ablation of RBPJ decreased BMP‐mediated osteoblastogenesis. Finally, systemic Notch inhibition using diabenzazepine (DBZ) reduced BMP2‐induced calvarial bone healing in mice supporting the critical regulatory role of Notch signaling in BMP‐induced osteoblastogenesis.Bone morphogenetic protein (BMP) stimulation of bone‐marrow‐derived human mesenchymal progenitor cells (hMSCs) increases Notch proteins via increased Notch ligand Jagged1 expression. Canonical Notch signaling is required for BMP‐induced ALPL expression and osteoblastic commitment of hMSCs. Both BMP‐induced osteoblastogenesis and Notch‐induced osteoblastogenesis require Runx2.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/162778/2/stem3245_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162778/1/stem3245.pd
Affect Variability and Cortisol in Context: The Moderating Roles of Mean Affect and Stress
Positive and negative affect have been shown to have implications for hormones like cortisol but how moment to moment changes in affect (i.e., affect variability) influence cortisol secretion is less well understood. Additionally, context characteristics such as mean affect and stress may influence the association between affect variability and cortisol output. In the current study, we examined affect, stress, and cortisol data from 113 participants (age range = 25–63, M = 35.63, SD = 11.34; 29 % male; 42 % White/Caucasian, 37 % Asian or Pacific Islander, 13 % Hispanic/Latino, 4 % Black/African American, 1 % Native American, Eskimo, or Aleut, 4 % selected “other” for their race/ethnicity). Participants completed ecological momentary assessments assessing positive and negative affect and stress four times per day for five days and provided saliva samples at each time point. Saliva was assayed for cortisol, and area under the curve with respect to ground was computed. In a three-way interaction, both positive affect mean level and stress moderated the association between positive affect variability and cortisol (b = −1.55, t(100) = −3.29, SE = 0.47, p \u3c.01, β = −4.05). When breaking down this three-way interaction, in the context of low stress and high mean positive affect, variability was positively related to total cortisol output. In contrast, in the context of high stress and high mean positive affect, variability was negatively related to total cortisol output. While greater positive affect variability is generally worse for health-relevant outcomes (as prior research has shown and as we show here at low levels of stress), at high levels of stress, fluctuation in affect may be adaptive. For someone experiencing a high stress week, having fluctuations in positive affect may mean that they are adaptively changing to meet their environmental needs especially when they typically report high mean positive affect levels. There were no associations between negative affect variability and cortisol secretion nor did mean negative affect or stress play a moderating role for negative affect variability. This study provides evidence that positive affect variability’s association with cortisol secretion throughout the day may vary based on stress and mean positive affect levels
METEORITOS Y ASTROBLEMAS DE LA PATAGONIA ARGENTINA
Todos hemos escuchado hablar de meteoritos, o visto sus devastadores impactos en películas de ficción. Pero, ¿qué son?, ¿cómo se producen y de dónde provienen? ¿Con qué frecuencia llegan a nuestro planeta? ¿Impactan o han impactado alguna vez en nuestra región? Los meteoritos son trozos de asteroides que vagan por el espacio recorriendo órbitas propias. Buena parte de ellos proviene del cinturón de asteroides que hay entre Marte y Júpiter. Este artículo ofrece un recorrido por los posibles cráteres de impacto meteorítico y una guía de los meteoritos hallados en su territorio
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