RESUMEN
This work presents a study on a new uranium iron arsenide UFe5As3. By implementing Bi-flux synthesis, we were able to grow mm-sized single crystals of this compound, which show twinning. UFe5As3 is one of only two known uranium iron arsenides. It adopts a monoclinic, UCr5P3-type crystal structure (space group P21/m, Pearson symbol mP18, a = 7.050(2) Å, b = 3.8582(9) Å, c = 9.634(1) Å, ß = 100.25(1)°). The magnetic susceptibility of UFe5As3 indicates it to be an antiferromagnet with TN = 47 K and µeff = 4.94 µB per formula unit, signaling that both U and Fe are likely magnetic in this material. The material appears to be anisotropic, with a small (likely ferromagnetic) spin reorientation transition around T = 29 K. The Sommerfeld coefficient γ0 = 135 mJ mol-1 K-2 suggests enhanced effective electron mass in UFe5As3, while electrical resistivity indicates metallic, Kondo-like behavior.
RESUMEN
This study investigated transfer of improvements in stability recovery performance to novel perturbations. Thirty adults (20-53 yr) were assigned equally to three treadmill walking groups: groups exposed to eight trip perturbations of either low or high magnitude and a third control group that walked unperturbed. Following treadmill walking, participants were exposed to stability loss from a forward-inclined position (lean-and-release) and an overground trip. Lower limb joint kinematics for the swing phase of recovery steps was compared for the three tasks using statistical parametric mapping and recovery performance was analysed by margin of stability and base of support. The perturbation groups improved stability (greater margin of stability) over the eight gait perturbations. There was no group effect for stability recovery in lean-and-release. For the overground trip, both perturbation groups showed similar enhanced stability recovery (margin of stability and base of support) compared to controls. Differences in joint angle kinematics between treadmill-perturbation and lean-and-release were more prolonged and greater than between the two gait perturbation tasks. This study indicates that: (i) practising stability control enhances human resilience to novel perturbations; (ii) enhancement is not necessarily dependent on perturbation magnitude; (iii) differences in motor response patterns between tasks may limit transfer.
Asunto(s)
Equilibrio Postural , Caminata , Adulto , Humanos , Equilibrio Postural/fisiología , Caminata/fisiología , Marcha/fisiología , Fenómenos Biomecánicos , Prueba de EsfuerzoRESUMEN
The ability to effectively increase the base of support is crucial to prevent from falling due to stability disturbances and has been commonly assessed using the forward-directed lean-and-release test. With this multicentre study we examined whether the assessment of stability recovery performance using two different forward lean-and-release test protocols is reliable in adults over a wide age range. Ninety-seven healthy adults (age from 21 to 80 years) were randomly assigned to one out of two lean angle protocols: gradual increase to maximal forward-lean angle (maximal lean angle; n = 43; seven participants were excluded due to marker artefacts) or predefined lean angle (single lean angle; n = 26; 21 participants needed to be excluded due to multiple stepping after release or marker artefacts). Both protocols were repeated after 0.5 h and 48 h to investigate intra- and inter-session reliability. Stability recovery performance was examined using the margin of stability at release (MoSRL) and touchdown (MoSTD) and increase in base of support (BoSTD). Intraclass correlation coefficients (confidence intervals at 95%) for the maximal lean angle and for the single lean angle were respectively 0.93 (0.89-0.96) and 0.94 (0.89-0.97) in MoSRL, 0.85 (0.77-0.91) and 0.67 (0.48-0.82) in MoSTD and 0.88 (0.81-0.93) and 0.80 (0.66-0.90) in BoSTD, with equivalence being revealed for each parameter between all three measurements (p < 0.01). We concluded that the assessment of stability recovery performance parameters in adults over a wide age range with the means of the forward lean-and-release test is reliable, independent of the used lean angle protocol.
Asunto(s)
Accidentes por Caídas , Equilibrio Postural , Adulto , Humanos , Recién Nacido , Estudios Multicéntricos como Asunto , Ensayos Clínicos Controlados Aleatorios como Asunto , Reproducibilidad de los ResultadosRESUMEN
The quantum Hall effect (QHE) is traditionally considered to be a purely two-dimensional (2D) phenomenon. Recently, however, a three-dimensional (3D) version of the QHE was reported in the Dirac semimetal ZrTe5. It was proposed to arise from a magnetic-field-driven Fermi surface instability, transforming the original 3D electron system into a stack of 2D sheets. Here, we report thermodynamic, spectroscopic, thermoelectric and charge transport measurements on such ZrTe5 samples. The measured properties: magnetization, ultrasound propagation, scanning tunneling spectroscopy, and Raman spectroscopy, show no signatures of a Fermi surface instability, consistent with in-field single crystal X-ray diffraction. Instead, a direct comparison of the experimental data with linear response calculations based on an effective 3D Dirac Hamiltonian suggests that the quasi-quantization of the observed Hall response emerges from the interplay of the intrinsic properties of the ZrTe5 electronic structure and its Dirac-type semi-metallic character.
RESUMEN
Differences in the adaptation processes between muscle and tendon in response to mechanical loading can lead to non-uniform mechanical properties within the muscle-tendon unit (MTU), potentially increasing injury risk. The current study analysed the mechanical properties of the triceps surae (TS) MTU in 10 young (YS; 22 ± 3 yrs) and 10 older (OS; age 65 ± 8 yrs; i.e. master) (inter)national level sprinters and 11 young recreationally active adults (YC; 23 ± 3 yrs) to detect possible non-uniformities in muscle and tendon adaptation due to habitual mechanical loading and ageing. Triceps surae muscle strength, tendon stiffness and maximal tendon strain were assessed in both legs during maximal voluntary isometric plantarflexion contractions via dynamometry and ultrasonography. Irrespective of the leg, OS and YC in comparison to YS demonstrated significantly (P < 0.05) lower TS muscle strength and tendon stiffness, with no differences between OS and YC. Furthermore, no group differences were detected in the maximal tendon strain (average of both legs: OS 3.7 ± 0.8%, YC 4.4 ± 0.8% and YS 4.3 ± 0.9%) as well as in the inter-limb symmetry indexes in muscle strength, tendon stiffness and maximal tendon strain (range across groups: -5.8 to 4.9%; negative value reflects higher value for the non-preferred leg). Thus, the findings provide no clear evidence for a disruption in the TS MTU uniformity in master sprinters, demonstrating that ageing tendons can maintain their integrity to meet the increased functional demand due to elite sports.
Asunto(s)
Contracción Isométrica , Tendones , Fenómenos Biomecánicos , Músculo Esquelético/diagnóstico por imagen , Tendones/diagnóstico por imagen , UltrasonografíaAsunto(s)
Fracturas Óseas , Luxaciones Articulares , Huesos Metatarsianos , Huesos Tarsianos , Fracturas Óseas/diagnóstico por imagen , Fracturas Óseas/cirugía , Humanos , Luxaciones Articulares/diagnóstico por imagen , Luxaciones Articulares/cirugía , Huesos Metatarsianos/diagnóstico por imagen , Huesos Metatarsianos/cirugía , Huesos Tarsianos/diagnóstico por imagen , Huesos Tarsianos/cirugíaRESUMEN
We investigate the possibility of indirectly constraining the B + â K + τ + τ - decay rate using precise data on the B + â K + µ + µ - dimuon spectrum. To this end, we estimate the distortion of the spectrum induced by the B + â K + τ + τ - â K + µ + µ - re-scattering process, and propose a method to simultaneously constrain this (non-standard) contribution and the long-distance effects associated to hadronic intermediate states. The latter are constrained using the analytic properties of the amplitude combined with data and perturbative calculations. Finally, we estimate the sensitivity expected at the LHCb experiment with present and future datasets. We find that constraints on the branching fraction of O ( 10 - 3 ) , competitive with current direct bounds, can be achieved with the current dataset, while bounds of O ( 10 - 4 ) could be obtained with the LHCb upgrade-II luminosity.
RESUMEN
Tick-borne encephalitis virus (TBEV) and louping-ill virus (LIV) are two closely related zoonotic flaviviruses leading to neurological diseases and belonging to the tick-borne encephalitis (TBE) serocomplex. Both viruses are transmitted by the same ixodid tick vector, Ixodes ricinus. Due to global warming affecting vector biology and pathogen transmission, the viruses pose an emerging threat for public health in Europe and Asia. These flaviviruses share some hosts, like sheep, goats and humans, although the main hosts for LIV and TBEV are sheep and small rodents, respectively. Whereas LIV has been detected in Spanish sheep and goat herds, circulating antibodies against TBEV have only been reported in dogs and horses from particular regions in this country. The limited available information about the prevalence of these viruses in Spain led us to investigate the serological evidence of TBE flaviviruses in horses from Spain. Serum neutralization tests (SNT) were performed using sera from 495 breeding and sport horses collected during two periods (2011-2013 and 2015-2016). A seroprevalence of 3.1 % (95 % CI 1.5-4.6) was found and cross-reactivity with West Nile virus was excluded in the positive samples. Sport horses showed a significantly higher TBE serocomplex seropositivity compared to breeding horses. An increased seroprevalence was observed in the second sampling period (2015-2016). Our results demonstrate for the first time the presence of antibodies against TBE flaviviruses in horses residing in mainland Spain; further epidemiological surveys are necessary in order to understand and monitor the active transmission of TBE flaviviruses in this country and rule out the presence of other flaviviruses co-circulating in Spain.
Asunto(s)
Virus de la Encefalitis Transmitidos por Garrapatas/aislamiento & purificación , Encefalitis Transmitida por Garrapatas/veterinaria , Enfermedades de los Caballos/epidemiología , Animales , Anticuerpos Antivirales/sangre , Encefalitis Transmitida por Garrapatas/diagnóstico , Encefalitis Transmitida por Garrapatas/epidemiología , Encefalitis Transmitida por Garrapatas/virología , Femenino , Enfermedades de los Caballos/diagnóstico , Enfermedades de los Caballos/virología , Caballos , Masculino , Prevalencia , Estudios Seroepidemiológicos , España/epidemiologíaRESUMEN
An efficient application of a material is only possible if we know its physical and chemical properties, which is frequently obstructed by the presence of micro- or macroscopic inclusions of secondary phases. While sometimes a sophisticated synthesis route can address this issue, often obtaining pure material is not possible. One example is TaGeIr, which has highly sample-dependent properties resulting from the presence of several impurity phases, which influence electronic transport in the material. The effect of these minority phases was avoided by manufacturing, with the help of focused-ion-beam, a µm-scale device containing only one phase-TaGeIr. This work provides evidence for intrinsic semiconducting behavior of TaGeIr and serves as an example of selective single-domain device manufacturing. This approach gives a unique access to the properties of compounds that cannot be synthesized in single-phase form, sparing costly and time-consuming synthesis efforts.
RESUMEN
BACKGROUND: Frailty and the metabolic Syndrome (MetS) are frequently found in old subjects and have been associated with increased risk of functional decline and dependency. Moreover, central characteristics of the MetS like inflammation, obesity and insulin resistance have been associated with the frailty syndrome. However, the relationship between MetS and frailty has not yet been studied in detail. Aim of the current analysis within the Berlin Aging Study II (BASE-II) was to explore associations between MetS and frailty taking important co-variables such as nutrition (total energy intake, dietary vitamin D intake), physical activity and vitamin D-status into account. METHODS: Complete cross-sectional data of 1,486 old participants (50.2% women, 68.7 (65.8-71.3) years) of BASE-II were analyzed. MetS was defined following the joint interim statement of the International Diabetes Federation Task Force on Epidemiology and Prevention; National Heart, Lung, and Blood Institute; American Heart Association; World Heart Federation; International Atherosclerosis Society; and International Association for the Study of Obesity in 2009. Frailty was defined according to the Fried criteria. Limitations in physical performance were assessed via questionnaire, muscle mass was measured using dual energy X-ray absorptiometry (DXA) and grip strength using a Smedley dynamometer. Adjusted regression models were calculated to assess the association between MetS and Frailty. RESULTS: MetS was prevalent in 37.6% of the study population and 31.9% were frail or prefrail according to the here calculated frailty index. In adjusted models the odds of being frail/prefrail were increased about 50% with presence of the MetS (OR1.5; 95% CI 1.2,1.9; p= 0.002). Moreover the odds of being prefrail/frail were significantly increased with low HDL-C (OR: 1.5 (95%CI: 1.0-2.3); p = 0.037); and elevated waist circumference (OR: 1.65 (95%CI: 1.1-2.3); p = 0.008). CONCLUSION: The current analysis supports an association between MetS and frailty. There are various metabolic, immune and endocrine alterations in MetS that also play a role in mechanisms underlying the frailty syndrome. To what extent cytokine alterations, inflammatory processes, vitamin D supply and hormonal changes in age and in special metabolic states as MetS influence the development of frailty should be subject of further research.
Asunto(s)
Fragilidad/epidemiología , Síndrome Metabólico/epidemiología , Anciano , Berlin/epidemiología , Estudios Transversales , Femenino , Anciano Frágil , Humanos , MasculinoRESUMEN
BACKGROUND: Coccygodynia is still often considered a mystery, and many patients are not taken seriously with their problems and pain. CASE: A 51-year-old thin lady presented at our clinic with lifelong, persistent low back pain. The clinical examination indicated suspicion of coccygodynia. A functional Xray revealed a hypermobile os coccygeum with dorsal tilt. After a total coccygectomy via a y-shaped approach, she was completely pain free at the 12 months follow-up examination. No surgical site infection occurred in this period.
Asunto(s)
Dolor de la Región Lumbar , Dolor Musculoesquelético , Cóccix , Femenino , Humanos , Persona de Mediana Edad , Radiografía , Resultado del TratamientoRESUMEN
Cuprates exhibit antiferromagnetic, charge density wave (CDW), and high-temperature superconducting ground states that can be tuned by means of doping and external magnetic fields. However, disorder generated by these tuning methods complicates the interpretation of such experiments. Here, we report a high-resolution inelastic x-ray scattering study of the high-temperature superconductor YBa2Cu3O6.67 under uniaxial stress, and we show that a three-dimensional long-range-ordered CDW state can be induced through pressure along the a axis, in the absence of magnetic fields. A pronounced softening of an optical phonon mode is associated with the CDW transition. The amplitude of the CDW is suppressed below the superconducting transition temperature, indicating competition with superconductivity. The results provide insights into the normal-state properties of cuprates and illustrate the potential of uniaxial-pressure control of competing orders in quantum materials.
RESUMEN
In the publication of this article [1], there are reference errors in four positions the respective references are missing since reference Fischer [26] was omitted.
RESUMEN
BACKGROUND: The focus of this case report is on the role of inflammation as a contributor to pain in plantar fasciitis and its cure by the injection of local anesthetics. CASE PRESENTATION: This is a case report on a 24-year-old white man, a middle-distance runner, with chronic unilateral plantar fasciitis and perceived heel pain for almost 1.5 years. He was treated with neural therapy (that is, injection of < 1 ml procaine 1% which is a local anesthetic with strong anti-inflammatory properties) of the surgical scar and along the surgical puncture channel. The follow-up period from the time of first presentation until publication was 2.5 years. At admission, pain intensity (visual analog scale) in the affected leg was severe (10 cm, visual analog scale; range 0-10 cm) when walking and moderate (5 cm, visual analog scale) when standing. After the first session of injections he could stand pain-free and pain when walking was markedly reduced (- 90%). After the third session, he reported no pain in the affected leg and could return to sports at his former level (no difference in training load compared to non-injured state). There was no recurrence of inflammatory signs or heel pain despite intense athletics training up to the date of publication. CONCLUSIONS: In prolonged cases of plantar fasciitis, inflammation is an important component in the development of persistent pain. The results of our case describe the effects of three neural therapy sessions that abolished inflammation and associated heel pain. Neural therapy might be an effective and time-efficient approach in the treatment of plantar fasciitis, enabling an early return to sports.
Asunto(s)
Anestésicos Locales/administración & dosificación , Antiinflamatorios/administración & dosificación , Fascitis Plantar/tratamiento farmacológico , Inflamación/tratamiento farmacológico , Dolor/tratamiento farmacológico , Procaína/administración & dosificación , Traumatismos en Atletas/diagnóstico , Traumatismos en Atletas/tratamiento farmacológico , Traumatismos en Atletas/etiología , Traumatismos en Atletas/cirugía , Fascitis Plantar/complicaciones , Fascitis Plantar/cirugía , Fasciotomía , Talón , Humanos , Inflamación/diagnóstico , Inflamación/etiología , Inflamación/cirugía , Masculino , Dolor/diagnóstico , Dolor/etiología , Dolor/cirugía , Manejo del Dolor , Dimensión del Dolor , Carrera/lesiones , Resultado del Tratamiento , Adulto JovenRESUMEN
BACKGROUND: Taking part in physical education is an important element of social participation for children with chronic diseases. Nevertheless, children suffering from rheumatism mostly receive recommendations to stop sport activities either completely or partially, without underlying scientific guidelines. OBJECTIVE: The aim was the development of an IT-tool based on scientific data in order to create individualized recommendations for sport activities plus verification of its practical feasibility. MATERIAL AND METHODS: An interdisciplinary group of experts developed and approved a prototype of the rheumatism and sports compass (Rheuma und Sport Kompass, RSK) based on the literature and own experience. They considered individual health factors and biomechanics of sports functions. The prototype was tested, revised and reconsidered in an interim evaluation. The resulting RSKv1 was evaluated in a clinical observation phase with 61 patients. The results were subsequently incorporated into the final version of RSK during an interdisciplinary decision-making process. This was verified in a feasibility study with a follow-up survey of rheumatic patients with a RSK partial participation certification for physical education including: clinical assessment during 8 lessons of physical education and after 8 lessons of physical education. Teachers rated the RSK online after 8 lessons. The evaluation was descriptive and differences in mean values were tested. RESULTS AND DISCUSSION: In this study 50 patients and 31 teachers were evaluated. The affliction of pain decreased in terms of frequency, amount and duration after physical education with RSK. No worsening in health was reported after participation in sports. The teachers rated the RSK as understandable, practicable and they felt confident to allow the patients to participate in classes. The RSK was rated significantly better than a standard certification text. With the RSK, patients can be advised to safely take part in physical education.
Asunto(s)
Educación y Entrenamiento Físico , Enfermedades Reumáticas , Deportes , Certificación , Niño , Humanos , Examen Físico , Enfermedades Reumáticas/diagnósticoRESUMEN
BACKGROUND: Minimal invasive screw fixation is common for treating posterior pelvic ring pathologies, but lack of bone quality may cause anchorage problems. The aim of this study was to report in detail a new technique combining iliosacral screw fixation with in-screw cement augmentation (ISFICA). DESCRIPTION OF TECHNIQUE: The patient was put under general anesthesia and placed in the supine position. A K-wire was inserted under inlet-outlet view to guide the fully threaded screw. The screw placement followed in adequate position. Cement was applied through a bone filler device, inserted at the screwdriver. The immediate control of cement distribution, accurate screw placement and potential leakage were obtained via intraoperative CT scan. PATIENTS AND METHODS: Twenty consecutive patients treated with ISFICA were included in this study. The mean age was 74.4 years (range 48-98). Screw placement, possible cement leakage and screw positioning were evaluated via intraoperative CT scan. Postoperative neurologic deficits, pain reduction and immediate postoperative mobilization were clinically evaluated. RESULTS: Twenty-six screws were implanted. All patients were postoperatively, instantly mobilized with reduced pain. No neurologic deficits were apparent postoperatively. No cement leakage occurred. One breach of the iliac cortical bone was noted due to severe osteoporosis. One screw migration was seen after 1 year and two patients showed iliosacral joint arthropathy, which led to screw removal. CONCLUSION: ISFICA is a very promising technique in terms of safety, precision and initial postoperative outcome. Long-term outcomes such as lasting mechanical stability or pain reduction and screw loosening despite cement augmentation should be investigated in further studies with larger patient numbers.
Asunto(s)
Tornillos Óseos , Fracturas Óseas/cirugía , Huesos Pélvicos/lesiones , Sacro/lesiones , Anciano , Anciano de 80 o más Años , Cementos para Huesos , Femenino , Fijación Interna de Fracturas , Fracturas Óseas/diagnóstico por imagen , Humanos , Ilion/lesiones , Cuidados Intraoperatorios , Masculino , Persona de Mediana Edad , Tomografía Computarizada por Rayos X , Resultado del TratamientoRESUMEN
A ferromagnetic quantum critical point is thought not to exist in two- and three-dimensional metallic systems yet is realized in the Kondo lattice compound YbNi_{4}(P,As)_{2}, possibly due to its one-dimensionality. It is crucial to investigate the dimensionality of the Fermi surface of YbNi_{4}P_{2} experimentally, but common probes such as angle-resolved photoemission spectroscopy and quantum oscillation measurements are lacking. Here, we study the magnetic-field dependence of transport and thermodynamic properties of YbNi_{4}P_{2}. The Kondo effect is continuously suppressed, and additionally we identify nine Lifshitz transitions between 0.4 and 18 T. We analyze the transport coefficients in detail and identify the type of Lifshitz transitions as neck or void type to gain information on the Fermi surface of YbNi_{4}P_{2}. The large number of Lifshitz transitions observed within this small energy window is unprecedented and results from the particular flat renormalized band structure with strong 4f-electron character shaped by the Kondo lattice effect.
RESUMEN
The most effective and sustainable method to control and eliminate rabies in wildlife is the oral rabies vaccination (ORV) of target species, namely foxes and raccoon dogs in Europe. According to WHO and OIE, the effectiveness of oral vaccination campaigns should be regularly assessed via disease surveillance and ORV antibody monitoring. Rabies antibodies are generally screened for in field animal cadavers, whose body fluids are often of poor quality. Therefore, the use of alternative methods such as the enzyme-linked immunosorbent assay (ELISA) has been proposed to improve reliability of serological results obtained on wildlife samples. We undertook an international collaborative study to determine if the commercial BioPro ELISA Rabies Ab kit is a reliable and reproducible tool for rabies serological testing. Our results reveal that the overall specificity evaluated on naive samples reached 96.7%, and the coefficients of concordance obtained for fox and raccoon dog samples were 97.2% and 97.5%, respectively. The overall agreement values obtained for the four marketed oral vaccines used in Europe were all equal to or greater than 95%. The coefficients of concordance obtained by laboratories ranged from 87.2% to 100%. The results of this collaborative study show good robustness and reproducibility of the BioPro ELISA Rabies Ab kit.
Asunto(s)
Anticuerpos Antivirales/sangre , Ensayo de Inmunoadsorción Enzimática/métodos , Programas de Inmunización , Vacunas Antirrábicas/inmunología , Virus de la Rabia/inmunología , Rabia/veterinaria , Administración Oral , Animales , Animales Salvajes/virología , Zorros/virología , Cooperación Internacional , Rabia/epidemiología , Rabia/inmunología , Rabia/prevención & control , Vacunas Antirrábicas/administración & dosificación , Perros Mapache/virología , Juego de Reactivos para Diagnóstico , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
Two 4-month-old female Doberman puppies were presented with clinical signs of acute diarrhea and emesis. They also showed sneezing and nasal discharge. The clinical presentation and neutropenia were suggestive of a parvovirus infection. The puppies were hospitalized for several days and treated symptomatically. Fecal samples tested negative for parasites. Virological examination of feces using polymerase chain reaction (PCR) and immune electron microscopy failed to confirm a parvovirus infection. With a recently developed PCR, bocavirus could be identified, thus making an infection with this virus a possible diagnosis. This case report presents a less well-known viral puppy disease and its successful therapy.