1,043 research outputs found
Interacting Antiferromagnetic Droplets in Quantum Critical CeCoIn_5
The heavy fermion superconductor CeCoIn_5 can be tuned between
superconducting and antiferromagnetic ground states by hole doping with Cd.
Nuclear magnetic resonance (NMR) data indicate that these two orders coexist
microscopically with an ordered moment ~0.7 \mu_B. As the ground state evolves,
there is no change in the low frequency spin dynamics in the disordered state.
These results suggest that the magnetism emerges locally in the vicinity of the
Cd dopants.Comment: 4 pages, 4 figure
Disorder in a Quantum Critical Superconductor
In four classes of materials, the layered copper-oxides, organics,
iron-pnictides and heavy-fermion compounds, an unconventional superconducting
state emerges as a magnetic transition is tuned toward absolute zero
temperature, that is, toward a magnetic quantum-critical point (QCP). In most
materials, the QCP is accessed by chemical substitutions or applied pressure.
CeCoIn5 is one of the few materials that are born as a quantum-critical
superconductor and, therefore, offers the opportunity to explore the
consequences of chemical disorder. Cadmium-doped crystals of CeCoIn5 are a
particularly interesting case where Cd substitution induces long-range magnetic
order, as in Zn-doped copper-oxides. Applied pressure globally supresses the
Cd-induced magnetic order and restores bulk superconductivity. Here we show,
however, that local magnetic correlations, whose spatial extent decreases with
applied pressure, persist at the extrapolated QCP. The residual droplets of
impurity-induced magnetic moments prevent the reappearance of conventional
signatures of quantum criticality, but induce a heterogeneous electronic state.
These discoveries show that spin droplets can be a source of electronic
heterogeneity in classes of strongly correlated electron systems and emphasize
the need for caution when interpreting the effects of tuning a correlated
system by chemical substitution.Comment: main text and supplementary informatio
Paramonga : caso de una cooperativa de producci?n agroindustrial
Tiene por objeto analizar el desarrollo y la estructura actual de la Cooperativa Agraria de Producci?n Paramonga Ltda. n.? 37. El Estudio responde fundamentalmente a la necesidad de conocer la manera como una empresa de raigambre capitalista se convierte en cooperativa. En este sentido, se analiza especialmente la forma en que el poder de gesti?n y el producto de la actividad empresarial pasan de la compa??a americana Grace a manos de los socios cooperativistas, quienes tambi?n est?n adquiriendo progresivamente la propiedad del capital social. En la primera parte del estudio se examinan los antecedentes hist?ricos del complejo agroindustrial de Paramonga y c?mo su propietaria, la Grace, a ra?z de la expropiaci?n por el Estado de la parte agr?cola al aplicar la ley de Reforma Agraria, asegura sus operaciones empresariales en el pa?s mediante la consolidaci?n de sus actividades industriales en Lima, Paramonga y Trujillo. En la segunda y tercera parte se analizan los varios aspectos constitutivos, econ?micos y organizativos de esta cooperativa y los problemas que se presentan al asumir los trabajadores la gesti?n y el control de la empresa
Microscopic evidence for field-induced magnetism in CeCoIn
We present NMR data in the normal and superconducting states of CeCoIn
for fields close to T in the plane. Recent
experiments identified a first-order transition from the normal to
superconducting state for T, and a new thermodynamic phase below 290
mK within the superconducting state. We find that the Knight shifts of the
In(1), In(2) and the Co are discontinuous across the first-order transition and
the magnetic linewidths increase dramatically. The broadening differs for the
three sites, unlike the expectation for an Abrikosov vortex lattice, and
suggests the presence of static spin moments in the vortex cores. In the
low-temperature and high-field phase the broad NMR lineshapes suggest ordered
local moments, rather than a long wavelength quasiparticle spin density
modulation expected for an FFLO phase.Comment: 4 pages, 4 figures. to appear in Phys. Rev. Let
Imaging diagnostics and pathology in sars-cov-2-related diseases
In December 2019, physicians reported numerous patients showing pneumonia of unknown origin in the Chinese region of Wuhan. Following the spreading of the infection over the world, The World Health Organization (WHO) on 11 March 2020 declared the novel severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) outbreak a global pandemic. The scientific community is exerting an extraordinary effort to elucidate all aspects related to SARS-CoV-2, such as the structure, ultrastructure, invasion mechanisms, replication mechanisms, or drugs for treatment, mainly through in vitro studies. Thus, the clinical in vivo data can provide a test bench for new discoveries in the field of SARS-CoV-2, finding new solutions to fight the current pandemic. During this dramatic situation, the normal scientific protocols for the development of new diagnostic procedures or drugs are frequently not completely applied in order to speed up these processes. In this context, interdisciplinarity is fundamental. Specifically, a great contribution can be provided by the association and interpretation of data derived from medical disciplines based on the study of images, such as radiology, nuclear medicine, and pathology. Therefore, here, we highlighted the most recent histopathological and imaging data concerning the SARS-CoV-2 infection in lung and other human organs such as the kidney, heart, and vascular system. In addition, we evaluated the possible matches among data of radiology, nuclear medicine, and pathology departments in order to support the intense scientific work to address the SARS-CoV-2 pandemic. In this regard, the development of artificial intelligence algorithms that are capable of correlating these clinical data with the new scientific discoveries concerning SARS-CoV-2 might be the keystone to get out of the pandemic
Modelo de simulación para el proceso de producción en empresas de confección textil
The UTS is developing the project Information System of production costs for micro and small children's clothing companies in Bucaramanga, adjusted to the conditions and requirements of these organizations which has in its most elementary part in order to determine the elements that must be integrated into the production costs in micro and small children garment companies also facilitates understanding the methodology associated with the techniques, methods, processes and procedures to be applied to the costing system according to the conditions and parameters of production operations in companies, therefore it is an input for the training of stakeholders.Las UTS tiene en ejecución el proyecto Sistema de información de costos de producción para las micros y pequeñas empresas del sector confecciones infantiles de Bucaramanga, ajustado a las condiciones y requerimientos de estas organizaciones que cuenta en su parte más elemental con el objeto de determinar los elementos que se deben integrar a los costos de producción en las micros y pequeñas empresas de confección infantil; además permite la comprensión de la metodologÃa relacionada con las técnicas, métodos, procesos y procedimientos que se aplican al sistema de costeo de acuerdo a las condiciones y parámetros de las operaciones de producción en las micro y pequeñas empresas de confección textil [ECT], por lo tanto es un insumo par
Assessment of sars-cov-2 infection through rapid serology testing in the homeless population in the city of rome, Italy. Preliminary results
Background: The development of COVID-19 pandemic has affected all segments of the population; however, it had a significant impact on vulnerable subjects, such as in people experiencing homelessness. The aim of this study was to evaluate the prevalence of COVID-19 spread in homeless persons in the city of Rome, Italy. Design and Methods: Patients included in the study underwent a clinical evaluation and rapid antibody analysis on capillary blood for the presence of immunoglobulin G (IgG) and immunoglobulin M (IgM) antibodies to SARS-CoV-2 virus. Symptomatic patients were not included in the screening and immediately referred to local hospitals for further evaluation. Results: One-hundred seventy-three patients of both sexes were tested for SARS-CoV-2 infection through rapid serological test. Age range was 10-80 years; people came from 35 different countries of origin and 4 continents. Test results were negative for most patients (170-98.2%); two patients had positive IgM (1.2%) and one patient had positive IgG (0.6%). Conclusions: Our study is the first to evaluate the prevalence of SARS-CoV-2 infection in people experiencing homelessness in the city of Rome, Italy. Most patients were negative for COVID-19, although several factors may have had an impact on this result, such as the exclusion of symptomatic patients, the limited sensitivity of rapid serological tests in the initial stage of infection and the prevention measures adopted in these populations. Larger studies on fragile populations are needed to prevent and intercept new clusters of infection in the upcoming months
The Satisfaction of the Students on Home-Based Distance Learning in the Philippines
Distance education has quickly been integrated into the education system anywhere, and the pandemic has intensified the need for it. The Philippines is just one of the countries that grappled with the effects of the unseen enemy; therefore, leaning mainly to home-based learning just cope to the need for learning and continuity. This study aimed to elicit the satisfaction level of Filipino college students both enrolled in private and public higher education in the country. To proceed with the study, the researchers adapted an 18-item questionnaire to find out the satisfaction level of the students in the home-based learning modality implemented in the entire country during the school year 2022 – 2023. Using the satisfaction scale adapted from Nabayra and Tambong (2023), results showed that Filipino students had an overall slight satisfaction with the implemented home-based learning modality. Moreover, the demographics, namely gender, year level, type of institution, and type of home-based learning modality, are not directly associated with students' level of satisfaction, which can only contribute less than 1% of the variance to their satisfaction
Immune system alterations in lung cancer patients.
The immune system plays an important role in the defense against neoplastic disease and immune responses show temporal changes related to circadian variations of antibodies, total lymphocytes in the peripheral blood and cell mediated immune responses. In this study we evaluate, lymphocyte subpopulations and interleukin-2 (IL-2) serum levels in peripheral blood samples collected at four-hour intervals for 24-hours starting at 06.00h from ten healthy subjects aged 65–79 years (mean age ± S.E. 67.28 ±3.11) and from ten subjects suffering from untreated non small cell lung cancer aged 65–78 years (mean age ± S.E. 68.57 ± 1.81). Areas under the curve, mean diurnal levels (mean of 06.00–10.00–14.00 h) and mean nocturnal levels (mean of 18.00–22.00–02.00 h) were calculated, and the presence of circadian rhythmicity was evaluate. When we compared AUC values there was a decrease in CD8bright (T suppressor subset) and an increase in CD16 (natural killer cells) and of IL-2 serum levels in cancer patients. When we compared mean diurnal levels, CD8 (T suppressor/cytotoxic subset) and CD8bright levels were lower, and CD16 levels were higher in cancer patients. When we compared mean nocturnal levels, CD16 and CD25 (T and B activated lymphocytes with expression of the a chain of IL-2 receptor) levels were higher, while CD8, CD8bright, CD20 (total B-cells), TcRd1 (epitope of the constant domain of d chain of T-cell receptor 1) and dTcS1 (epitope of the variable domain of d chain of T-cell receptor1) levels were lower in cancer patients. A clear circadian rhythm was validated for the time-qualified changes in CD4, CD20, HLA-DR with acrophase at night, and CD8, CD8bright, CD8dim, CD16, TcRd1 and dTcS1 with acrophase in the morning in the control group. A clear circadian rhythm was validated for the time-qualified changes in CD4 with acrophase at night, in the group of cancer patients. Results obtained in our study show that lung cancer is associated with anomalies of proportion and circadian variations of lymphocyte subsets that must be considered when adoptive immunotherapy has to be planned
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