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1.
Public Health ; 228: 100-104, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38342075

RESUMEN

OBJECTIVES: Malawi's disease surveillance system is built on several different data sources and systems and is informed by the Integrated Diseases Surveillance and Response (IDSR) strategy. This study was carried out as part of a larger multicountry study to identify context-specific factors, which influence the operationalization of integrated disease surveillance. STUDY DESIGN AND METHODS: A total of six focus group discussions were conducted with 43 relevant personnel at the primary and secondary healthcare levels in two districts (Lilongwe and Dowa) and at the national level. The discussions were analyzed and sorted into predefined categories based on the domains of the International Association of Public Health conceptual framework. RESULTS: We found ongoing efforts to enhance integrated disease surveillance operationalization, including the establishment of the Public Health Institute of Malawi for coordination, digitalizing the surveillance system through One Health Surveillance Platform, and improving communication among rapid response teams using WhatsApp. The adoption of World Health Organization's third edition IDSR technical guidelines was also underway. Nonetheless, there were major implementation barriers such as parallel and uncoordinated surveillance systems, priority conditions that cannot be diagnosed at the point of reporting, lack of case definitions and diagnostic codes for priority conditions, reporting forms with unexplained acronyms, illegible data sources, unstable electronic data transfers, inadequate supervision and training, poor enforcement of reporting from private health facilities, high reporting burden, and lack of and feedback to those reporting. CONCLUSIONS: The results fit well into the predefined categories used. The study reveals basic problems with the operationalization, tools, and reporting forms used for IDSR. These findings may have implications for practice and policy in Malawi and other countries where IDSR is the national strategy for surveillance.


Asunto(s)
Control de Enfermedades Transmisibles , Brotes de Enfermedades , Humanos , Control de Enfermedades Transmisibles/métodos , Malaui/epidemiología , Salud Pública , Atención a la Salud , Vigilancia de la Población/métodos
2.
Public Health ; 225: 141-146, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37925838

RESUMEN

OBJECTIVES: Integrated disease surveillance (IDS) offers the potential for better use of surveillance data to guide responses to public health threats. However, the extent of IDS implementation worldwide is unknown. This study sought to understand how IDS is operationalized, identify implementation challenges and barriers, and identify opportunities for development. STUDY DESIGN: Synthesis of qualitative studies undertaken in seven countries. METHODS: Thirty-four focus group discussions and 48 key informant interviews were undertaken in Pakistan, Mozambique, Malawi, Uganda, Sweden, Canada, and England, with data collection led by the respective national public health institutes. Data were thematically analysed using a conceptual framework that covered governance, system and structure, core functions, finance and resourcing requirements. Emerging themes were then synthesised across countries for comparisons. RESULTS: None of the countries studied had fully integrated surveillance systems. Surveillance was often fragmented, and the conceptualization of integration varied. Barriers and facilitators identified included: 1) the need for clarity of purpose to guide integration activities; 2) challenges arising from unclear or shared ownership; 3) incompatibility of existing IT systems and surveillance infrastructure; 4) workforce and skills requirements; 5) legal environment to facilitate data sharing between agencies; and 6) resourcing to drive integration. In countries dependent on external funding, the focus on single diseases limited integration and created parallel systems. CONCLUSIONS: A plurality of surveillance systems exists globally with varying levels of maturity. While development of an international framework and standards are urgently needed to guide integration efforts, these must be tailored to country contexts and guided by their overarching purpose.


Asunto(s)
Salud Pública , Humanos , Grupos Focales , Investigación Cualitativa , Uganda/epidemiología , Recolección de Datos
3.
Anaesthesia ; 69(11): 1227-40, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-24974961

RESUMEN

Surgical anaesthesia with haemodynamic stability and opioid-free analgesia in fragile patients can theoretically be provided with lumbosacral plexus blockade. We compared a novel ultrasound-guided suprasacral technique for blockade of the lumbar plexus and the lumbosacral trunk with ultrasound-guided blockade of the lumbar plexus. The objective was to investigate whether the suprasacral technique is equally effective for anaesthesia of the terminal lumbar plexus nerves compared with a lumbar plexus block, and more effective for anaesthesia of the lumbosacral trunk. Twenty volunteers were included in a randomised crossover trial comparing the new suprasacral with a lumbar plexus block. The primary outcome was sensory dermatome anaesthesia of L2-S1. Secondary outcomes were peri-neural analgesic spread estimated with magnetic resonance imaging, sensory blockade of dermatomes L2-S3, motor blockade, volunteer discomfort, arterial blood pressure change, block performance time, lidocaine pharmacokinetics and complications. Only one volunteer in the suprasacral group had sensory blockade of all dermatomes L2-S1. Epidural spread was verified by magnetic resonance imaging in seven of the 34 trials (two suprasacral and five lumbar plexus blocks). Success rates of the sensory and motor blockade were 88-100% for the major lumbar plexus nerves with the suprasacral technique, and 59-88% with the lumbar plexus block (p > 0.05). Success rate of motor blockade was 50% for the lumbosacral trunk with the suprasacral technique and zero with the lumbar plexus block (p < 0.05). Both techniques are effective for blockade of the terminal nerves of the lumbar plexus. The suprasacral parallel shift technique is 50% effective for blockade of the lumbosacral trunk.


Asunto(s)
Plexo Lumbosacro , Bloqueo Nervioso/métodos , Ultrasonografía Intervencional/métodos , Adulto , Estudios Cruzados , Método Doble Ciego , Voluntarios Sanos , Humanos , Lidocaína/sangre , Imagen por Resonancia Magnética , Estudios Prospectivos
4.
Phys Rev Lett ; 110(12): 126804, 2013 Mar 22.
Artículo en Inglés | MEDLINE | ID: mdl-25166834

RESUMEN

A combined experimental and theoretical study of doping individual Fe atoms into Bi(2)Se(3) is presented. It is shown through a scanning tunneling microscopy study that single Fe atoms initially located at hollow sites on top of the surface (adatoms) can be incorporated into subsurface layers by thermally activated diffusion. Angle-resolved photoemission spectroscopy in combination with ab initio calculations suggest that the doping behavior changes from electron donation for the Fe adatom to neutral or electron acceptance for Fe incorporated into substitutional Bi sites. According to first principles calculations within density functional theory, these Fe substitutional impurities retain a large magnetic moment, thus presenting an alternative scheme for magnetically doping the topological surface state. For both types of Fe doping, we see no indication of a gap at the Dirac point.

5.
Phys Rev Lett ; 108(25): 256811, 2012 Jun 22.
Artículo en Inglés | MEDLINE | ID: mdl-23004640

RESUMEN

The robustness of the gapless topological surface state hosted by a 3D topological insulator against perturbations of magnetic origin has been the focus of recent investigations. We present a comprehensive study of the magnetic properties of Fe impurities on the prototypical 3D topological insulator Bi(2)Se(3) using local low-temperature scanning tunneling spectroscopy and integral x-ray magnetic circular dichroism techniques. Single Fe adatoms on the Bi(2)Se(3) surface, in the coverage range ≈ 1% of a monolayer, are heavily relaxed into the surface and exhibit a magnetic easy axis within the surface plane, contrary to what was assumed in recent investigations on the supposed opening of a gap. Using ab initio approaches, we demonstrate that an in-plane easy axis arises from the combination of the crystal field and dynamic hybridization effects.

6.
Euro Surveill ; 17(33)2012 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-22913978

RESUMEN

The impact of influenza on work absenteeism is poorly documented. We used data from the national registry and Norway Post AS (>14,000 employees) to explore sickness absence patterns from 2005/06 through 2009/10 in Norway. Annually, an estimated 2.868% (mean 95% confidence interval (CI): 2.405-4.820%) of the working population obtained sick leave for influenza, of whom 0.915% (mean 95% CI: 0.453-1.590%) had diagnoses for other respiratory illnesses with influenza as underlying cause. In the 2009/10 pandemic season, the absence rate increased 1.5-fold, mainly due to a 73% increase in influenza-diagnosed sick leaves. At Norway Post AS, absence related to seasonal influenza accounted for 0.351% (mean 95% CI: 0.126-0.704%) of total person-days annually (excluding parental care absence), of which 32-43% were estimated to be self-certified. Medically certified sick leave increased 1.3-fold in the pandemic season to 0.458% (95% CI: 0.176-0.856), while self-certified sick leave remained at a level typical for seasonal influenza. We found a significant four-fold increase in work loss to care for sick children, 0.048% (95% CI: 0.031-0.070%) of person-days, compared with 0.012% (95% CI: 0.004-0.028%) in 2008/09. In conclusion, GP-certified and parental care work absence were higher in the pandemic season. More studies are needed to quantify the burden of self-certified sick leave.


Asunto(s)
Absentismo , Epidemias , Subtipo H1N1 del Virus de la Influenza A , Gripe Humana/epidemiología , Ausencia por Enfermedad/estadística & datos numéricos , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Noruega/epidemiología , Sistema de Registros , Análisis de Regresión , Trabajo , Adulto Joven
7.
Nat Commun ; 13(1): 3096, 2022 Jun 02.
Artículo en Inglés | MEDLINE | ID: mdl-35654938

RESUMEN

In spintronics, the two main approaches to actively control the electrons' spin involve static magnetic or electric fields. An alternative avenue relies on the use of optical fields to generate spin currents, which can bolster spin-device performance, allowing for faster and more efficient logic. To date, research has mainly focused on the optical injection of spin currents through the photogalvanic effect, and little is known about the direct optical control of the intrinsic spin-splitting. To explore the optical manipulation of a material's spin properties, we consider the Rashba effect. Using time- and angle-resolved photoemission spectroscopy (TR-ARPES), we demonstrate that an optical excitation can tune the Rashba-induced spin splitting of a two-dimensional electron gas at the surface of Bi2Se3. We establish that light-induced photovoltage and charge carrier redistribution - which in concert modulate the Rashba spin-orbit coupling strength on a sub-picosecond timescale - can offer an unprecedented platform for achieving optically-driven spin logic devices.

8.
Phys Rev Lett ; 107(9): 096802, 2011 Aug 26.
Artículo en Inglés | MEDLINE | ID: mdl-21929260

RESUMEN

We report a Rashba spin splitting of a two-dimensional electron gas in the topological insulator Bi(2)Se(3) from angle-resolved photoemission spectroscopy. We further demonstrate its electrostatic control, and show that spin splittings can be achieved which are at least an order-of-magnitude larger than in other semiconductors. Together these results show promise for the miniaturization of spintronic devices to the nanoscale and their operation at room temperature.

9.
J Phys Chem A ; 115(45): 13061-71, 2011 Nov 17.
Artículo en Inglés | MEDLINE | ID: mdl-21863852

RESUMEN

Analysis of accurate experimental and theoretical structure factors of diamond and silicon reveals that the contraction of the core shell due to covalent bond formation causes significant perturbations of the total charge density that cannot be ignored in precise charge density studies. We outline that the nature and origin of core contraction/expansion and core polarization phenomena can be analyzed by experimental studies employing an extended Hansen-Coppens multipolar model. Omission or insufficient treatment of these subatomic charge density phenomena might yield erroneous thermal displacement parameters and high residual densities in multipolar refinements. Our detailed studies therefore suggest that the refinement of contraction/expansion and population parameters of all atomic shells is essential to the precise reconstruction of electron density distributions by a multipolar model. Furthermore, our results imply that also the polarization of the inner shells needs to be adopted, especially in cases where second row or even heavier elements are involved in covalent bonding. These theoretical studies are supported by direct multipolar refinements of X-ray powder diffraction data of diamond obtained from a third-generation synchrotron-radiation source (SPring-8, BL02B2).

10.
Epidemiol Infect ; 138(11): 1559-68, 2010 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-20334732

RESUMEN

Influenza can be a serious, sometimes deadly, disease, especially for people in high-risk groups such as the elderly and patients with underlying, severe disease. In this paper we estimated the influenza-related excess mortality in Norway for 1975-2004, comparing it with dominant virus types and estimates of the reproduction number. Analysis was done using Poisson regression, explaining the weekly all-cause mortality by rates of reported influenza-like illness, together with markers for seasonal and year-to-year variation. The estimated excess mortality was the difference between the observed and predicted mortality, removing the influenza contribution from the prediction. We estimated the overall influenza-related excess mortality as 910 deaths per season, or 2.08% of the overall deaths. Age-grouped analyses indicated that the major part of the excess mortality occurred in the > or =65 years age group, but that there was also a significant contribution to mortality in the 0-4 years age group. Estimates of the reproduction number R, ranged from about 1 to 1.69.


Asunto(s)
Gripe Humana/epidemiología , Gripe Humana/mortalidad , Adolescente , Adulto , Distribución por Edad , Anciano , Niño , Preescolar , Humanos , Lactante , Recién Nacido , Persona de Mediana Edad , Noruega/epidemiología , Distribución de Poisson , Estaciones del Año , Factores de Tiempo , Adulto Joven
11.
Euro Surveill ; 14(45)2009 Nov 12.
Artículo en Inglés | MEDLINE | ID: mdl-19941789

RESUMEN

In Norway there is an ongoing outbreak in pigs of infections with pandemic influenza A(H1N1)v virus. The first herd was confirmed positive on 10 October 2009. As of 26 October, a total of 23 herds have been diagnosed as positive. The majority of the herds seem to have been infected by humans. Sequence analysis of pig viruses from the index farm shows that they are identical or virtually identical to human viruses from the same geographical region.


Asunto(s)
Brotes de Enfermedades/veterinaria , Subtipo H1N1 del Virus de la Influenza A/aislamiento & purificación , Gripe Humana/virología , Infecciones por Orthomyxoviridae/veterinaria , Enfermedades de los Porcinos/transmisión , Animales , Brotes de Enfermedades/prevención & control , Femenino , Humanos , Gripe Humana/transmisión , Masculino , Cavidad Nasal/virología , Noruega/epidemiología , Infecciones por Orthomyxoviridae/prevención & control , Infecciones por Orthomyxoviridae/transmisión , Sus scrofa , Porcinos , Enfermedades de los Porcinos/epidemiología , Enfermedades de los Porcinos/prevención & control
12.
Euro Surveill ; 14(17)2009 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-19422767

RESUMEN

Hand hygiene represents the single most effective way to prevent healthcare-associated infections. The World Health Organization, as part of its First Global Patient Safety Challenge, recommends implementation of multi-faceted strategies to increase compliance with hand hygiene. A questionnaire was sent by the European Centre for Disease Prevention and Control to 30 European countries, regarding the availability and organisation of their national hand hygiene campaigns. All countries responded. Thirteen countries had organised at least one national campaign during the period 2000-2009 and three countries were in the process of organising a national campaign. Although the remaining countries did not have a national campaign, several reported regional and local hand hygiene activities or educational resources on national websites.


Asunto(s)
Control de Enfermedades Transmisibles/métodos , Control de Enfermedades Transmisibles/estadística & datos numéricos , Desinfección de las Manos/métodos , Promoción de la Salud/organización & administración , Promoción de la Salud/estadística & datos numéricos , Higiene , Europa (Continente) , Humanos
13.
J Am Chem Soc ; 130(25): 7988-96, 2008 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-18512920

RESUMEN

The charge density (CD) of coordination polymer Co3(C8H4O4)4(C4H12N)2(C5H11NO)3 (1) has been determined from multipole modeling of structure factors obtained from single-crystal synchrotron X-ray diffraction measurements at 16 K. The crystal structure formally contains a negatively charged framework with cations and neutral molecules in the voids. However, the CD suggests that the framework is close to neutral, and therefore qualitative conclusions based on formal charge counting, e.g., about guest inclusion properties, will be incorrect. There are considerable differences in the charge distributions of the three unique benzenedicarboxylic acid linkers, which are widely used in coordination polymers. This suggests that the electrostatic properties of coordination polymer cavities, and thereby their inclusion properties, are highly tunable. The electron density topology shows that the tetrahedrally coordinated Co atom has an atomic volume which is 15% larger than that of the octahedrally coordinated Co atom. The crystal structure has both ferromagnetic and antiferromagnetic interactions, but no direct metal-metal bonding is evidenced in the CD. The magnetic ordering therefore takes place through superexchange in the oxygen bridges and the aromatic linkers. Bonding analysis of the experimental CD reveals that two oxygen atoms, O(1) and O(11), have significant covalent contributions to the metal-ligand bonding, whereas all other oxygen atoms have closed-shell interactions with the metals. This indicates that these two oxygen atoms are the key mediators of the magnetic ordering.

14.
Acta Neurochir (Wien) ; 150(4): 337-44; discussion 344, 2008 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-18297231

RESUMEN

BACKGROUND: In patients with supratentorial tumours, intracranial pressure is a strong predictor of intra-operative brain swelling and thresholds for ICP associated with brain swelling have been defined. Whether these ICP thresholds can be applied during infratentorial surgery is uncertain. We studied the relationship between subdural ICP and the degree of brain swelling after opening of the dura mater in patients subjected to infratentorial surgery. Thresholds for ICP associated with brain swelling were defined. METHODS: One hundred and nine adult patients subjected to infratentorial surgery were studied. Subdural ICP was measured immediately before opening of the dura and the degree of brain swelling was estimated by the neurosurgeon according to a four-point scale. FINDINGS: At ICP less than 7 mmHg brain swelling did not occur. In the range from 7 to 13 mmHg 21 of 39 patients (54%) had moderate swelling, but not pronounced swelling. At ICP greater than 13 mmHg some degree of swelling occurred in all patients, and at ICP exceeding 24 mmHg pronounced cerebral swelling was found in all patients. Using logistic regression analysis specific thresholds for ICP associated with brain swelling were defined as follows: at an ICP equal to or greater than 13 mmHg, brain swelling occurred with 95% probability; and at an ICP less than 6 mmHg brain swelling occurred with 5% probability. CONCLUSIONS: Subdural ICP measured before opening of the dura mater can predict the risk of brain swelling during infratentorial surgery. Thresholds for ICP associated with brain swelling are close to thresholds defined in patients undergoing supratentorial surgery.


Asunto(s)
Edema Encefálico/fisiopatología , Craneotomía , Neoplasias Infratentoriales/cirugía , Malformaciones Arteriovenosas Intracraneales/cirugía , Presión Intracraneal/fisiología , Complicaciones Intraoperatorias/fisiopatología , Neuralgia del Trigémino/cirugía , Adulto , Anciano , Edema Encefálico/diagnóstico , Duramadre/cirugía , Femenino , Humanos , Neoplasias Infratentoriales/fisiopatología , Malformaciones Arteriovenosas Intracraneales/fisiopatología , Complicaciones Intraoperatorias/diagnóstico , Modelos Logísticos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Monitoreo Intraoperatorio , Espacio Subdural , Tomografía Computarizada por Rayos X , Neuralgia del Trigémino/fisiopatología
15.
J Environ Qual ; 37(5): 1710-8, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18689732

RESUMEN

Pesticides applied to agricultural soils are subject to environmental concerns because leaching to groundwater reservoirs and aquatic habitats may occur. Knowledge of field variation of pesticide-related parameters is required to evaluate the vulnerability of pesticide leaching. The mineralization and sorption of the pesticides glyphosate and metribuzin and the pesticide degradation product triazinamin in a field were measured and compared with the field-scale variation of geochemical and microbiological parameters. We focused on the soil parameters clay and organic carbon (C) content and on soil respiratory and enzymatic processes and microbial biomass. These parameters were measured in soil samples taken at two depths (Ap and Bs horizon) in 51 sampling points from a 4-ha agricultural fine sandy soil field. The results indicated that the spatial variation of the soil parameters, and in particular the content of organic C, had a major influence on the variability of the microbial parameters and on sorption and pesticide mineralization in the soil. For glyphosate, with a co-metabolic pathway for degradation, the mineralization was increased in soils with high microbial activity. The spatial variability, expressed as the CV, was about five times higher in the Bs horizon than in the Ap horizon, and the local-scale variation within 100 m(2) areas were two to three times lower than the field-scale variation within the entire field of about 4 ha.


Asunto(s)
Herbicidas/química , Dióxido de Silicio/química , Microbiología del Suelo , Contaminantes del Suelo/química , Suelo/análisis , Adsorción , Biomasa , Dinamarca , Glicina/análogos & derivados , Glicina/química , Residuos de Plaguicidas , Plaguicidas/química , Triazinas/química , Glifosato
16.
Dalton Trans ; 47(27): 9136-9142, 2018 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-29946581

RESUMEN

Synthesis of phase pure hopeite pigment through a solvothermal flow method is reported here for the first time. The products show two-step dehydration behaviour from thermogravimetric analysis (TGA), and a higher degree of purity and homogeniety than commercial zinc phosphate pigment. By increasing the reaction temperature stepwise from room temperature to 350 °C it was possible to decrease the size of the individual crystallite sheets and to tune their packing into larger assemblies. The conversion of reactants to product proved to be significantly higher at increased temperature with a measured yield of 98.7% at 250 °C versus 85.4% at room temperature. The synthesis route demonstrated here is environmentally sustainable, increases cost-efficiency through minimization of waste, and is compatible with a scale-up strategy.

17.
Nat Commun ; 8: 14074, 2017 01 17.
Artículo en Inglés | MEDLINE | ID: mdl-28094258

RESUMEN

The discovery of high-temperature superconductivity in Fe-based compounds triggered numerous investigations on the interplay between superconductivity and magnetism, and on the enhancement of transition temperatures through interface effects. It is widely believed that the emergence of optimal superconductivity is intimately linked to the suppression of long-range antiferromagnetic (AFM) order, although the exact microscopic picture remains elusive because of the lack of atomically resolved data. Here we present spin-polarized scanning tunnelling spectroscopy of ultrathin FeTe1-xSex (x=0, 0.5) films on bulk topological insulators. Surprisingly, we find an energy gap at the Fermi level, indicating superconducting correlations up to Tc∼6 K for one unit cell FeTe grown on Bi2Te3, in contrast to the non-superconducting bulk FeTe. The gap spatially coexists with bi-collinear AFM order. This finding opens perspectives for theoretical studies of competing orders in Fe-based superconductors and for experimental investigations of exotic phases in superconducting layers on topological insulators.

19.
Chem Commun (Camb) ; 52(16): 3434-7, 2016 Feb 25.
Artículo en Inglés | MEDLINE | ID: mdl-26832849

RESUMEN

γ-Fe2O3@SiO2, TiO2@SiO2, and α-Fe2O3@SiO2 core-shell nanoparticles were synthesized by a surfactant-free hydrothermal method in a continuous flow dual-stage reactor. Uniform silica shells of 2 nm thickness were obtained when grown on γ-Fe2O3 and TiO2 nanoparticles while thicker and more irregular shells were deposited on α-Fe2O3 due to low pH.

20.
Dalton Trans ; 45(9): 3798-805, 2016 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-26820716

RESUMEN

The layered semiconductor SnS2 spurs much interest for both intercalation and optoelectronic applications. Despite the wealth of research in the field of metal dichalcogenides, the structure-property relationship of this compound remains unclear. Here we present a thorough study combining single-crystal X-ray diffraction and DFT calculations on SnS2 in the pressure range 0 < p < 20 GPa. The anisotropic compression of the unit cell is clearly linked to the van der Waals interactions between the S-Sn-S sandwich layers, as the compression mainly affects the interlayer distance. This compression behavior is coincidal with the compression of other well-known layered compounds (graphite and boron nitride) but differs significantly from the compression of other MS2 compounds, making it clear that SnS2 presents a unique and interesting case in the field of metal dichalcogenides. The compression leads to a significant increase in S···S interlayer interaction which in turn results in a change in the electronic structure, documented through DFT band structure calculations. The calculated narrowing of the band gap is supported by a significant, reversible color change of the single crystal. At 20 GPa, the size of the band gap has decreased from 2.15 to 0.88 eV, and band gap closure is predicted to occur at 33 GPa.

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