42 research outputs found
Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study
Background Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide.Methods A multimethods analysis was performed as part of the GlobalSurg 3 study-a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital.Findings Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3.85 [95% CI 2.58-5.75]; p<0.0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63.0% vs 82.7%; OR 0.35 [0.23-0.53]; p<0.0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer.Interpretation Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised
Evidence for widespread hydrated minerals on asteroid (101955) Bennu
Early spectral data from the Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) mission reveal evidence for abundant hydrated minerals on the surface of near-Earth asteroid (101955) Bennu in the form of a near-infrared absorption near 2.7 µm and thermal infrared spectral features that are most similar to those of aqueously altered CM-type carbonaceous chondrites. We observe these spectral features across the surface of Bennu, and there is no evidence of substantial rotational variability at the spatial scales of tens to hundreds of metres observed to date. In the visible and near-infrared (0.4 to 2.4 µm) Bennu’s spectrum appears featureless and with a blue (negative) slope, confirming previous ground-based observations. Bennu may represent a class of objects that could have brought volatiles and organic chemistry to Earth
The dynamic geophysical environment of (101955) Bennu based on OSIRIS-REx measurements
The top-shaped morphology characteristic of asteroid (101955) Bennu, often found among fast-spinning asteroids and binary asteroid primaries, may have contributed substantially to binary asteroid formation. Yet a detailed geophysical analysis of this morphology for a fast-spinning asteroid has not been possible prior to the Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) mission. Combining the measured Bennu mass and shape obtained during the Preliminary Survey phase of the OSIRIS-REx mission, we find a notable transition in Bennu’s surface slopes within its rotational Roche lobe, defined as the region where material is energetically trapped to the surface. As the intersection of the rotational Roche lobe with Bennu’s surface has been most recently migrating towards its equator (given Bennu’s increasing spin rate), we infer that Bennu’s surface slopes have been changing across its surface within the last million years. We also find evidence for substantial density heterogeneity within this body, suggesting that its interior is a mixture of voids and boulders. The presence of such heterogeneity and Bennu’s top shape are consistent with spin-induced failure at some point in its past, although the manner of its failure cannot yet be determined. Future measurements by the OSIRIS-REx spacecraft will provide insight into and may resolve questions regarding the formation and evolution of Bennu’s top-shape morphology and its link to the formation of binary asteroids
Untersuchung von Blochwänden und Domänen in Bariumferrit mit magnetischer Kernspinresonanz
Das Ziel dieser Arbeit ist es, zu untersuchen, welche Information über die Struktur und Bewegung einer Blochwand aus der Kernspin-Resonanz zu gewinnen ist. Die beste Information kann man erhalten, wenn die Resonanzfrequenz anisotrop ist, so daß eine getrennte Messung der verschiedenen Magnetisierungsrichtungen in der Wand möglich ist. Aus diesem Grund haben wir den Bariumferrit für unsere Messungen ausgewählt. Das Untergitter "a" ist besonders für die Untersuchung geeignet, da es eine große Anisotropie und hohe Intensität hat. In Domänen wurde der Verstärkungsfaktor , Spin-Gitter- und Spin-Spin-Relaxationszeit T und T gemessen, damit aus dem Vergleich dieser Größen mit den entsprechenden Meßergebnissen aus Blochwänden einige Schlußfolgerungen gezogen werden können. Aus der Messung der Abhängigkeit der Frequenz vom Feld für die Untergitter "a" und "c" ergibt sich, daß für beide Linien die Untergittermagnetisierungstreng antiparallel ist, dies steht in Widerspruch mit Messungen von Petrov und Kunevich. In dieser Arbeit ist zum ersten Mal der Zusammenhang zwischen und der Stelle in der Wand gemessen worden. Der Verlauf des Verstärkungsfaktors konnte mit dem üblichen Modell der 180 Blochwand, das Anisotropie und Austauschenergie berücksichtigt, erklärt werden. Der größte Verstärkungs faktor beträgt 6000 und ist 300-mal größer als der in Domänen. Dieser Wert ist erheblich kleiner als der abgeschätzte Wert für von 8 x 10 unter der Bedingung, daß die Wand dem äußeren Wechselfeld trägheitslos folgen kann. Die Wandmasse und die Bindungskräfte müssen also eine erhebliche Rolle spielen, obwohl die Verschiebung der Wand in dem We~hselfeld nur etwa 1 0/00 derWanddicke und die Geschwindigkeit um etwa 0.1 cm/s beträgt. Der Spin-Gitter-Relaxationsprozeß ist wesentlich stärker in Blochwänden als in Domänen. In dieser Arbeit wurde T als Funktion der Frequenz gemessen. Damit wurde zum ersten Mal der Zusammenhang zwischen T und - innerhalb einer Blochwand bestätigt; aus diesem Zusammenhang haben wir festgestellt, daß die Spin-Gitter-Relaxation in der Wand durch einen Einmagnonenprozeß entsteht. Andererseits ist auch die Spin-Spin-Relaxationszeit T in Blochwänden viel kürzer als in Domänen; dabei erfolgt die Kopplung zwischen zwei Fe-Kernen durch die Anregung und Absorption von Wandoszillationen ähnlich wie bei der Suhl-Nakamura-Wechselwirkung durch die Emission und Absorption von Magnonen in den homogen magnetisierten Bereichen
Nuclear spin-lattice and spin-spin relaxation in domain walls of hexagonal bariumferrite BaFe12O19
First Human Cases of <i>Leishmania (Viannia) lainsoni</i> Infection and a Search for the Vector Sand Flies in Ecuador
<div><p>An epidemiological study of leishmaniasis was performed in Amazonian areas of Ecuador since little information on the prevalent <i>Leishmania</i> and sand fly species responsible for the transmission is available. Of 33 clinical specimens from patients with cutaneous leishmaniasis (CL), causative parasites were identified in 25 samples based on cytochrome <i>b</i> gene analysis. As reported previously, <i>Leishmania (Viannia) guyanensis</i> and <i>L</i>. <i>(V</i>.<i>) braziliensis</i> were among the causative agents identified. In addition, <i>L</i>. <i>(V</i>.<i>) lainsoni</i>, for which infection is reported in Brazil, Bolivia, Peru, Suriname, and French Guiana, was identified in patients with CL from geographically separate areas in the Ecuadorian Amazon, corroborating the notion that <i>L</i>. <i>(V</i>.<i>) lainsoni</i> is widely distributed in South America. Sand flies were surveyed around the area where a patient with <i>L</i>. <i>(V</i>.<i>) lainsoni</i> was suspected to have been infected. However, natural infection of sand flies by <i>L</i>. <i>(V</i>.<i>) lainsoni</i> was not detected. Further extensive vector searches are necessary to define the transmission cycle of <i>L</i>. <i>(V</i>.<i>) lainsoni</i> in Ecuador.</p></div
Identification of sand fly species and detection of flagellates within individual sand flies by microscopic examinations.
<p>Identification of sand fly species and detection of flagellates within individual sand flies by microscopic examinations.</p
Phylogenetic tree of <i>cyt</i> b gene sequences among species.
<p>Leishmanial <i>cyt</i> b genes were amplified and sequenced from flagellates-positive sand flies, <i>Lutzomyia (Lu</i>.<i>) yuilli yuilli</i> (1, 4, 7, 8, 9, 11, 12, 15, and 16) and <i>Lu</i>. <i>davisi</i>, and a phylogenetic analysis of <i>cyt</i> b gene sequences was performed by the neighbor-joining method together with sequences from 12 <i>Leishmania</i> and 2 <i>Endotrypanum</i> species. The scale bar represents 0.05% divergence. Bootstrap values are shown above or below branches.</p
Identification of <i>Leishmania</i> species from patient specimens.
<p>Identification of <i>Leishmania</i> species from patient specimens.</p