1,693 research outputs found
Quantum spin fluctuations and the stability of atomically-sized Bloch points
We reveal the role of the spin variables' zero-point fluctuations (ZPFs) on
the stability of Bloch point (BP) singularities. As topological solitons, BPs
are important in topological transitions in nanomagnets. BPs present a
singularity at their core, where the long-length-scale approximation fails. We
found that ZPFs bloom nearby this core, reducing the effective magnetic moment
and increasing the BP's stability. As suggested by classical models, the
magnonic eigenmodes found by our methods fit with the bound state of an
electron surrounding a dyon, with a magnetic and an electric charge.Comment: Main: 5 pages, 4 figures. Supplementary material: 3 pages, 4 figure
Sinovitis Transitoria de Cadera: estudio Prospectivo de su Epidemiología y Valoración Diagnóstica
Se ha realizado un estudio prospectivo durante seis años del tratamiento
de 62 casos de Sinovitis Transitoria de Cadera sobre un total de 59 pacientes. La incidencia
anual media fué de 3,57 casos por 10.000 habitantes menores de 10 años de edad. El riesgo
de sufrir algún episodio de recurrencia era 300 veces mayor que el riesgo de sufrir un
primer episodio.
Se observó una mayor frecuencia en los meses de primavera y otoño.
Los valores de las pruebas de laboratorio y las radiografías standard fueron normales
en la mayoría de los casos; nosotros no hemos observado los signos indirectos clásicos de
derrame articular.
La enfermedad de Perthes se diagnosticó en dos casos, pero al revisar retrospectivamente
las radiografías iniciales se observó que uno de los casos presentaba signos de
necrosis avascular, mientras en el otro caso eran normales.
Para el diagnostico diferencial y la evolución, la gammagrafía ósea nos proporcionó un
relevante valor.The authors carried out a prospective study on 62 cases of Acute
Transient Synovitis of the Hip in 59 patients. The follow up was six years. The
average annual incidence was 3,57 per 10.000 population younge r than 10 years,
and the risk of recurrence was 300 greater than the risk of having a single
episode.
The greatest frequency was observed in Spring and Autum.
In most cases, the values of laboratory test and standard Rx was normal, we
observed no classic indirect signs from articular effusion.
Perthes'disease was diagnosed in two cases, but in retrospective review of
the initial radiographs revealed sings of avascular necrosis in one of them, and
the another case has had completely normal radiograph.
For the differential diagnosis and follow-up, the bone scintigraphy has a
relevant importance
Upcycling Mask Waste to Carbon Capture Sorbents: A Combined Experimental and Computational Study
Massive plastic pollution and grand scale emission of CO2 into the atmosphere represent two major and deeply connected societal challenges, which can have adverse impacts on climate, human health, and marine ecosystems. In particular, the COVID-19 pandemic led to substantially increased production, use, and discarding of disposable masks, a problem that requires urgent and effective technological solutions to mitigate their negative environmental impacts. Furthermore, over the years significant research efforts have sought to address the challenges of plastic waste and CO2 emission, such as development of chemical upcycling methods and low-cost CO2 capture sorbents at scale, respectively. In this work, we introduce a simple and scalable method for directly converting surgical polypropylene mask waste into sulfur-doped carbon fibers, which can exhibit a high CO2 sorption capacity of ≤3.11 mmol/g and high selectivity (\u3e45) against N2 gas. This excellent performance is attributed to the high affinity between sulfur heteroatoms in the carbon framework and CO2 gas molecules, confirmed by combined experimental and simulation investigations. This work provides an industrially viable approach for upcycling plastic waste into carbon-based products with increased value, which can then be employed to address the environmental challenges of CO2 remediation
On the uniqueness of the surface sources of evoked potentials
The uniqueness of a surface density of sources localized inside a spatial
region and producing a given electric potential distribution in its
boundary is revisited. The situation in which is filled with various
metallic subregions, each one having a definite constant value for the electric
conductivity is considered. It is argued that the knowledge of the potential in
all fully determines the surface density of sources over a wide class of
surfaces supporting them. The class can be defined as a union of an arbitrary
but finite number of open or closed surfaces. The only restriction upon them is
that no one of the closed surfaces contains inside it another (nesting) of the
closed or open surfaces.Comment: 16 pages, 5 figure
All for One and One for All: Voluntary Physicians in the Intensive Medicine Units During the COVID-19 Outbreak in Spain
COVID-19; Intensive care medicine; Hospital organizationCOVID-19; Medicina intensiva; Organització hospitalàriaCOVID-19; Medicina Intensiva; Organización hospitalariaObjectives: Our purpose was to determine the intensive care units' (ICU's) medical staff surge capacity during the coronavirus disease 2019 (COVID-19) outbreak in Spring 2020 in Spain.
Methods: A multicenter retrospective survey was performed addressing the medical specialties present in the ICUs and the increase in bed capacity during this period.
Results: Sixty-seven centers (62.04%) answered the questionnaire. The ICU bed capacity during the pandemic outbreak increased by 160% (95% confidence interval [CI], 128.97-191.03%). The average number of beds per intensive care medicine (ICM) specialist was 1.5 ± 0.60 and 3.71 ± 2.44 beds/specialist before and during the COVID-19 outbreak, respectively. Non-ICM specialists and residents were present in 50 (74.63%) and 23 (34.3%) ICUs during the outbreak, respectively. The number of physicians (ICM and non-ICM residents and specialists) in the ICU increased by 89.40% (95% CI, 64.26114.53%). The increase in ICM specialists was, however, 4.94% (95% CI, -1.35-11.23%). Most non-ICM physicians were anesthetists, followed by pediatricians and cardiologists.
Conclusions: The majority of ICUs in our study were able to rapidly expand critical care capacity by adapting areas outside of the normal ICU to manage critically ill patients, and by extending the critical care staff with noncritical care physicians working as force multipliers
Antigenic and genetic characterization of a divergent African virus, Ikoma lyssavirus
In 2009, a novel lyssavirus (subsequently named Ikoma lyssavirus, IKOV) was detected in the brain of an African civet (Civettictis civetta) with clinical rabies in the Serengeti National Park of Tanzania. The degree of nucleotide divergence between the genome of IKOV and those of other lyssaviruses predicted antigenic distinction from, and lack of protection provided by, available rabies vaccines. In addition, the index case was considered likely to be an incidental spillover event, and therefore the true reservoir of IKOV remained to be identified. The advent of sensitive molecular techniques has led to a rapid increase in the discovery of novel viruses. Detecting viral sequence alone, however, only allows for prediction of phenotypic characteristics and not their measurement. In the present study we describe the in vitro and in vivo characterization of IKOV, demonstrating that it is (1) pathogenic by peripheral inoculation in an animal model, (2) antigenically distinct from current rabies vaccine strains and (3) poorly neutralized by sera from humans and animals immunized against rabies. In a laboratory mouse model, no protection was elicited by a licensed rabies vaccine. We also investigated the role of bats as reservoirs of IKOV. We found no evidence for infection among 483 individuals of at least 13 bat species sampled across sites in the Serengeti and Southern Kenya
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Intermittent Escherichia coli O157:H7 colonisation at the terminal rectum mucosa of conventionally-reared lambs§
In cattle, the lymphoid rich regions of the rectal-anal mucosa at the terminal rectum are the preferred site for Escherichia coli O157:H7 colonisation. All cattle infected by rectal swab administration demonstrate long-term E. coli O157:H7 colonisation, whereas orally challenged cattle do not demonstrate long-term E. coli O157:H7 colonisation in all animals. Oral, but not rectal challenge of sheep with E. coli O157:H7 has been reported, but an exact site for colonisation in sheep is unknown. To determine if E. coli O157:H7 can effectively colonise the ovine terminal rectum, in vitro organ culture (IVOC) was initiated. Albeit sparsely, large, densely packed E. coli O157:H7 micro-colonies were observed on the mucosa of ovine and control bovine terminal rectum explants. After necropsy of orally inoculated lambs, bacterial enumeration of the proximal and distal gastrointestinal tract did suggest a preference for E. coli O157:H7 colonisation at the ovine terminal rectum, albeit for both lymphoid rich and non-lymphoid sites. As reported for cattle, rectal inoculation studies were then conducted to determine if all lambs would demonstrate persistent colonisation at the terminal rectum. After necropsy of E. coli O157:H7 rectally inoculated lambs, most animals were not colonised at gastrointestinal sites proximal to the rectum, however, large densely packed micro-colonies of E. coli O157:H7 were observed on the ovine terminal rectum mucosa. Nevertheless, at the end point of the study (day 14), only one lamb had E. coli O157:H7 micro-colonies associated with the terminal rectum mucosa. A comparison of E. coli O157:H7 shedding yielded a similar pattern of persistence between rectally and orally inoculated lambs. The inability of E. coli O157:H7 to effectively colonise the terminal rectum mucosa of all rectally inoculated sheep in the long term, suggests that E. coli O157:H7 may colonise this site, but less effectively than reported previously for cattle
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