Search

Johan Tham,1 Inga Odenholt,1 Mats Walder,2 Lina Andersson,1 Eva Melander2,3 1Infectious Diseases Unit, Department of Clinical Sciences, Lund University, Malmö, 2Medical Microbiology, Department of Laboratory Medicine, Lund University, Malmö, 3Department of Infection Control, Laboratory Medicine, Skåne County, Sweden Background: It is important to identify patients who are at risk for infections with extended-spectrum β-lactamase (ESBL)-producing bacteria in order to reduce mortality, to avoid spread of resistant bacteria in hospitals, and to minimize the number of patients receiving unnecessary treatment with broad-spectrum antibiotics. A case-control survey among Swedish patients was performed at Skåne University Hospital to identify risk factors for developing an infection with ESBL-producing Escherichia coli in a low endemic country. Methods: We used a computerized database to identify patients with growth of ESBL-producing E. coli (n = 109) in urine or blood cultures and an equal number of controls matched for age and gender with non ESBL-producing E. coli in urine and blood diagnosed between January and October 2008. We used unadjusted P-values. Results: Patients with ESBL-producing E. coli had a significantly (P < 0.05) higher likelihood of having traveled to Asia including Turkey and the Middle East including Egypt (14/58) than the non-ESBL-positive group (4/53). Hospital stay during the previous year (P < 0.04), especially for more than one month, was another significant (P = 0.01) risk factor for infection with ESBL-producing E. coli (8/58). A stay in the surgical department was a further risk factor (P < 0.01). Conclusion: In this study, we identified 22 of 58 (38%) patients with ESBL-producing E. coli by considered significant risk factors before starting antibiotics. Keywords: extended-spectrum β-lactamase, Enterobacteriaceae, resistant bacteria, risk factors, Escherichia coli

El dolor es considerado un signo vital, y es monitorizado tanto como la frecuencia cardiaca, frecuencia respiratoria, tensión arterial y temperatura. De su control depende en gran parte la calidad de vida de nuestros pacientes. Es por esto que requiere ser manejado de manera tal que a partir de él, quien lo presenta pueda desembolverse en sus actividades diarias, familiares, lúdicas, entre otras. Nuestra especialidad, lleva a cabo un papel muy relevante en la atención de los pacientes que sufren dolor, cualquiera sea su origen, utilizando los diferentes recursos de rehabilitación que se tienen a nuestro alcance y aciendo medición del impacto que este genera.

Reportamos el caso de un paciente con enfermedad diabética tipo 1 que sufrió un ACV isquémico lacunar talámico derecho y simultáneamente otro en la pirámide bulbar derecha, con manifestaciones sensitivas y motoras. Este cuadro clínico se consideró asociado a microangiopatía vascular por el antecedente personal de diabetes tipo 1 y debido a que los demás estudios realizados durante la atención médica no mostraron otra causa aparente.

Introducción: el Evento Cerebro Vascular (ECV) es una patología común en nuestro medio causante de múltiples secuelas y afecciones sociales, laborales y familiares. Impacta de manera importante el sistema de salud por los tratamientos requeridos. Objetivo: medir objetivamente el impacto funcional que genera el ECV a través de escalas NIHSS (severidad) y Barthel, determinando el grado de independencia funcional en los pacientes que lo sufrieron. Diagnosticar factores pronósticos y de riesgo en dicha población. Materiales y métodos: estudio descriptivo; evaluó 50 pacientes con ECV del Hospital Militar Central- Bogotá, con el fin de identificar sus factores pronósticos y de riesgo, aplicando escalas que reflejen el impacto real durante fase inicial (NIHSS antes de 72 horas - BARTHEL a los 8 días). Resultados: el 38% de pacientes presentaron severidad mayor inicial según escala NISHH, mostrando dependencia funcional grave o total al aplicar escala funcional Barthel una semana después. El 8% presentaron independencia funcional con escala Barthel. 16 % fallecieron durante la hospitalización por causas directas o indirectas. Las limitaciones funcionales más frecuente fueron al realizar traslados de silla-cama y deambulación (26%). El 20% presentaron alteración para el control intestinal y vesical. Conclusión: la medición de la discapacidad inicial en Evento Cerebro Vascular, permite identificar aspectos de mayor afección, definir metas individuales de rehabilitación y facilita seguir la evolución natural de la enfermedad. Una semana después del Ictus el 92% de pacientes presenta algún grado de dependencia funcional, por tanto las metas establecidas deben ser claras e individualizadas para una mayor ganancia a largo plazo durante rehabilitación.

The fission process still remains a main factor that determines the stability of the atomic nucleus of heaviest elements. Fission half-lives vary over a wide range, 10−19−1024 s. Present experimental techniques for the synthesis of the superheavy elements that usually measure α-decay chains are sensitive only in a limited range of half-lives, often 10−5−103 s. In the past years, measurement techniques for very short-lived and very long-lived nuclei were significantly improved at the gas-filled recoil separator TASCA at GSI Darmstadt. Recently, several experimental studies of fission-related phenomena have successfully been performed. In this paper, results on 254−256Rf and 266Lr are presented and corresponding factors for retarding the fission process are discussed.

Nuclides that are considered to be isotopes of element Z = 115 were produced in the reaction 48Ca + 243Am at the GSI Helmholtzzentrum für Schwerionenforschung Darmstadt. The detector setup TASISpec was used. It was mounted behind the gas-filled separator TASCA. Thirty correlated α-decay chains were found, and the energies of the particles were determined with high precision. Two important spectroscopic aspects of the offline data analysis are discussed in detail: the handling of digitized preamplified signals from the silicon strip detectors, and the energy reconstruction of particles escaping to upstream detectors relying on pixel-by-pixel dead-layer thicknesses.

Fast regrowth from deep roots and rhizomes makes it difficult to mechanically control the perennials Cirsium arvense and Tussilago farfara respectively. It is, however, not clear whether new shoots originate mainly from fragments of roots/rhizomes in upper soil layers or from an intact system below depth of soil cultivation. Here we present results from three experiments with natural infestations of C. arvense, and two with both C. arvense and T. farfara. Plots of 1 m2 were excavated to different depths (13–25 cm), all below‐ground plant parts in the topsoil were collected and thereafter fragments were either returned to or removed from the plots. Regrowth from disturbed plots with removed or returned fragments was compared. The origin of regrown shoots, that is, whether they originated from seeds, intact below‐ground root/rhizome systems or returned fragments, was examined. More C. arvense shoots originated from the intact root system (48%–84%) than from root fragments (16%–52%). The final aboveground biomass was not affected by removal of the top‐soil fragments. For T. farfara, a small proportion (3%) of new shoots originated from the intact rhizome system, and the rest from fragments. We conclude that the intact root system of C. arvense contributes at least as much as root fragments to regrowth after soil cultivation, which might imply that time of treatment and depth of cultivation are crucial for the effect of mechanical control. For T. farfara, the results suggest that tillage equipment with high capacity to fragment the rhizome system will contribute to efficient control. [ABSTRACT FROM AUTHOR]

Boundaries between space plasmas occur in numerous contexts and scales, from astrophysical jets to planetary magnetospheres. Mass and momentum transport across boundaries poses a fundamental problem in magnetospheric physics. Kelvin-Helmholtz instability (KHI) is a promising mechanism to facilitate transport. Although previous studies have suggested KHI occurrence in various space plasmas, theory predicts that compressibility prevents KHI excitation at boundaries with large density gradients because of previously considered boundary structures where density varies with velocity. Based on the observations of a large density gradient boundary by MAVEN at Mars, where we can observe an extreme case, in this study, we show that it is the entropy, instead of the previously considered density, that varies with the velocity in the real velocity-sheared boundary. The entropy-based boundary structure places the velocity shear in a lower-density region than the traditional density-based structure and weakens the compressibility effect. This new boundary structure thus enables KHI excitation even at large density gradient boundaries, such as at the ionopause of unmagnetized planets and the plasmapause of magnetized planets. The result suggests the ubiquitous occurrence of KHI in the plasma universe and emphasizes its important role in planetary cold plasma escape from unmagnetized planets. [ABSTRACT FROM AUTHOR]

An unusually low density solar wind event was observed in December 2022 moving past both Earth and Mars. The source was traced back to a coronal hole and active region on the Sun's surface. The resulting solar wind lead to the development of a co‐rotating interaction region (CIR) and trailing rarefaction region that lasted for multiple solar rotations. Within this structure, the solar wind conditions, including density, velocity, and magnetic field magnitude and orientation drastically changed. In this study we analyze the response of the Martian ionosphere using MAVEN data to these changing solar wind conditions. The low density solar wind region associated with the December event resulted in the expansion of the Martian ionospheric boundaries. We show that the ion composition boundary (ICB) is located at extreme altitudes that are beyond previously observed locations from the MAVEN mission between 2015 and 2018. Furthermore, the boundary between shocked solar wind and the Martian ionosphere identified using electron and ion data moved together on the dayside of the planet with the changing solar wind conditions. However, at the flank region these boundaries do not move together, and we show here that the decoupling of the two boundaries may be the result of a change in the interplanetary magnetic field azimuthal angle. Plain Language Summary: The Sun constantly emits fast moving charged particles into interplanetary space in what is known as the solar wind. In December 2022, a region of fast moving solar wind overtook a region of slower moving solar wind. The fast solar wind acted as a broom sweeping up and compressing the slower wind preceding it. This interaction of two solar wind speeds is observed to rotate with the Sun. Trailing this interaction region is a region of low density solar wind. In December 2022, this type of interplanetary solar wind structure interacted with Mars' electrically charged atmosphere, or ionosphere. Throughout this period, the ionosphere boundary characterized by a transition from solar wind ions to planetary ions moved up and down relative to the planet near dusk. As the rarefaction region passed through the system, the ionosphere expanded to unusually high heights as it was not compressed by the solar wind. However, the flapping of the ionospheric boundary seems to depend on the orientation that the solar wind interacts with Mars. Key Points: The disappearing solar wind event observed at Mars in December 2022 was caused by a co‐rotating interaction regionMars' ionosphere expanded further than previously observed locations between 2015 through 2018The flank ion composition boundary experiences large fluctuations in altitude after a change in the interplanetary magnetic field direction [ABSTRACT FROM AUTHOR]

On 26 December 2022 the solar wind density dropped by over an order of magnitude and remained low for about a day. We have utilized in‐situ plasma measurements made by the Mars Atmosphere and Volatile EvolutioN mission to determine how this change affected the Mars‐solar wind interaction. During this time period, on inbound orbit segments, MAVEN sampled the terminator ionosphere, which switched from a magnetized to unmagnetized state immediately following the minimum in solar wind density. The magnetic field amplitude was typically 5–10 nT within the upper ionosphere prior to the event and consistently <1 nT after. During the event the magnetic pressure dominated immediately above the ionosphere while within the ionosphere the ionospheric plasma pressure dominated. The high altitude terminator ionosphere remained in this unmagnetized state throughout the event, suggesting that it was the new equilibrium state of the system. The terminator upper ionosphere returned to its original magnetized state once the solar wind density had recovered. The outbound orbit segments sampled the dayside subsolar region which remained magnetized throughout the event: the magnetization state of the ionosphere varied locally, dependent upon the solar zenith angle and corresponding incident solar wind dynamic pressure. Such conditions are different to the commonly reported unmagnetized ionospheric state at Venus during solar maximum conditions, where the interplanetary magnetic field is repelled from the entire dayside ionosphere. Drastic changes in the upstream solar wind are able to change the Mars‐solar wind interaction state on timescales less than one MAVEN orbit (∼3.5 hr). Plain Language Summary: Our Sun emits a continuous stream of charged particles radially outward into our solar system, known as the solar wind. Much like flowing water in a river is deflected around rocks and other objects in the river, the solar wind is also deflected around most obstacles in our solar system, including the planets. The physical forces that control this deflection differ depending upon the characteristics of the planet and the solar wind as it encounters the obstacle. We have studied a rare event at the planet Mars when the solar wind density dropped to very low values over the course of a day. Using orbiting spacecraft observations we have shown that the physical processes that control how the solar wind flows around the planet change directly in response to this event. These processes reverted back to their prior states once the solar wind density recovered a few days later, demonstrating that the planet‐wide system responds to large changes in the solar wind density on timescales of a few hours or less. Key Points: The Mars terminator ionosphere transitioned to an unmagnetized state in response to the 'disappearing solar wind event' in December 2022The Mars‐solar wind interaction system responds to changes in the solar wind density on timescales <3.5 hrThe event shares similarities with when the Venus ionosphere is unmagnetized, but the localized nature is an important difference [ABSTRACT FROM AUTHOR]

In December 2022, an extremely low‐density solar wind stream encountered first the Earth and then Mars, shortly after the radial alignment of the two planets (i.e., Mars opposition). As the low‐density stream passed Mars, the properties of the Mars‐solar wind interaction changed dramatically in response to the low solar wind Alfvénic Mach number and dynamic pressure. The Martian magnetosphere and its boundaries expanded by thousands of kilometers, extending outside of the nominal average bow shock location. The low upstream Mach number resulted in a low ratio of plasma to magnetic field pressure in the magnetosheath, allowing the formation of a very high but stable ion temperature anisotropy, together with a very low level of electromagnetic instabilities. Meanwhile, the decrease in solar wind dynamic pressure caused the Martian upper ionosphere at the terminator to transition from a magnetized state to an unmagnetized state. This event provides an opportunity to study a unique end‐member state of the Mars‐solar wind interaction. Plain Language Summary: The solar wind consists of a supersonic flow of hot ionized gas (plasma) from the Sun that flows outward through the solar system. The solar wind interacts with planetary atmospheres and magnetic fields, which form shielded regions known as magnetospheres. The characteristics of the solar wind, including its density and speed, vary over a wide range. The shape, extent, and physical characteristics of planetary magnetospheres in turn respond to these changes in the solar wind. In this work, we study the response of the Martian magnetosphere to an extremely low‐density solar wind stream. During the passage of this stream, the Martian magnetosphere expanded by thousands of kilometers, and its physical characteristics changed dramatically. This event reveals a unique outlier state for the Mars‐solar wind interaction. Key Points: An extremely low‐density solar wind stream encountered the Earth and Mars just after Mars opposition in December 2022The Martian magnetosheath developed very unusual properties, with a low level of plasma instabilities and a high ion anisotropyThe Martian magnetosphere and its boundaries expanded by thousands of km, extending outside of the location of the nominal bow shock [ABSTRACT FROM AUTHOR]