Magnetism in Atomic-Sized Palladium Contacts and Nanowires

We have investigated Pd nanowires theoretically, and found that, unlike either metallic or free atomic Pd, they exhibit Hund's rule magnetism. In long, monoatomic wires, we find a spin moment of 0.7 Bohr magnetons per atom, whereas for short, monoatomic wires between bulk leads, the predicted moment is about 0.3 Bohr magnetons per wire atom. In contrast, a coaxial (6,1) wire was found to be nonmagnetic. The origin of the wire magnetism is analyzed.Comment: 6 pages, including 4 figure

Enhanced weak superconductivity in trigonal γ\gamma-PtBi2_2

Electrical transport experiments show superconductivity in a high-quality single crystal of trigonal $\gamma$-PtBi$_2$. The critical temperature shows a large dependence on the electrical current and in the limit of very low currents, a $T_c$ = 1.1 K is observed, while a zero temperature critical field $B_c$(0) $\approx$ 1.5 Tesla is estimated. These are the highest superconducting parameters reported (at ambient pressure) in a stoichiometric $\gamma$-PtBi$_2$ bulk sample so far. Under a magnetic field a strict zero resistance state is no longer observed even though an incipient superconducting transition is seen. Such a behavior is most probably associated with very low critical currents and is reminiscent of filamentary superconductivity. The superconducting state is elusive to magnetization measurements discarding a bulk phase down to $T =$ 0.3 K.Comment: 5 pages, 5 figure

Condiciones de trabajo y morbilidad entre mineros del carbón en Guachetá, Cundinamarca: La mirada de los legos

Introduction: Investigations in Colombia about work and health conditions in coal mining are scarce and few have focused on the perception of the exposed population and their behaviors in response to inherent risks. Objective: To determine the association between work conditions and the perception of morbidity among coal miners in Guachetá, Cundinamarca. Materials and methods: A cross-sectional study was performed with 154 workers selected randomly from the total registered with the municipality. Information about social and demographic characteristics and work and health conditions in the mines was gathered. The prevalence was estimated for respiratory, musculoskeletal and auditory disorders. The associations between certain work conditions, and events with a prevalence over 30% were explored using bivariate and multivariate analyses with Poisson regressions with robust variance. Results: Workers were mostly men. Ages ranged from 18 to 77 years. Most frequently reported health problems were: back pain (46.1 %), pain in an upper limb (40.3%), pain in a lower limb (34.4 %), andrespiratory (17.5 %) and auditory problems (13.6 %). Significant differences in perception were found depending on time on the job and underground or ground work conditions. Conclusions: The most recognized risks were those associated with musculoskeletal disorders since they were closer in time to the work performed (time discount). Some actions to identify psychological traits are proposed in order to improve risk perception among coal miners

Perfil clínico y social del paciente adicto hospitalizado

Objetivos: Determinar las características clínicas y morbilidad de los pacientes (pac.) adictos ingresados a un Servicio de Clínica Médica. Material y métodos: Estudio protocolizado, observacional, descriptivo y transversal. Criterio de inclusión: pac. adicto con consumo de sustancias ilícitas. Informe preliminar: Periodo: 24 meses. Datos analizados en Epi info 6.4 Resultados: Se incluyeron 40 pac. Prevalencia: 0.2/1000 egresos. El 82.5% eran hombres. Edad media: 31.5 años (DS±9.65). Permanencia media: 11 días (DS±13.98) vs 7.12 (DS±10.1) del Servicio (p=0.016). Consumían cocaína el 82.5% (IC95%67.22-92.66) marihuana el 77.5% (IC95% 61.65- 89.16), tolueno el 10% (IC95%2.79-23.66), floripondio y hachis el 2.5% (IC95% 0.06-13.16) cada uno. En el 2.5% la vía de administración era endovenosa y el 60% eran poliadictos. Solo el 10% recibió tratamiento para abandonar la adicción (100% tratamiento psicológico y 5.13% farmacológico). De clase social pobre el 75%. El 62.5% de los pac. estaban desocupados, tenían antecedentes judiciales el 10% y el 7.5% había estado en prisión. El 92.5% (IC95% 76.34-97.21) era heterosexual, 2.5% hombres que tenían sexo con hombres y bisexuales 5% (IC95% 0.61-16.92). Solo el 10% tenían secundaria completa. El 80% ingreso por Emergencias y por causa infecciosa el 45%. El 12.5% ingreso por complicaciones de la adicción. Las manifestaciones relacionadas con la adicción fueron: manifestaciones del sistema nervioso central: 12.5% (IC95%4.19-26.80); síndrome de abstinencia y temblor 7.5% cada uno y excitación psicomotriz, delirium, signo de foco neurológico y rigidez 5% cada uno. El 100% presentaba alguna comórbida; tabaquismo 80%, depresión 12.8% Y alcoholismo 57.5%, entre otras. Presentaban enfermedades de transmisión sexual 5 pac. (4 HIV, 2 VHC y 1 pediculus pubis). No hubo mortalidad hospitalaria. Conclusión: El paciente adicto internado se caracteriza por ser joven, pertenecer a un grupo social desprotegido, sin trabajo y sin educación, tener poliadicción, con alta carga de comórbidas y de internación, principalmente por complicaciones infecciosas.Objectives: To determine the clinical features and morbidity of addict patients (pac.) admitted to a Service of Medical Clinic. Material and Methods: In a protocolized, descriptive and observational study of 24 month we studied patients patient addicted to consumption of illicit substances. Preliminary Report. Data was analized with Epi Info 6.4. Results: 40 patients included. Prevalence: 0.2/1000 exits. The 82.5% (CI95%67.22-92.66) were men. Average Age: 31.5 years (SD±9.65), the mean hospital stay: 11 days (SD±13.98) vs. 7.12 (SD±10.1) of the Service (p=0.016). The 82.5% cocaine consumers (CI95%67.22-92.66) 77.5% marijuana consumers (CI95% 61.65-77.92), toluene 10 % (CI95%2.79-23.66), Datura metel and Hashish 2.5% (CI95 0.06-13.16) each. In the 2.5%, the way of administration was endovenous and 60% were poli-addicts. Only 10% received treatment to quit the addiction (100% psychological treatment and 5.13% pharmacological). Poor social class 75% (CI95%58.80-87.31); middle class 22.5% (CI95%10.84-38.45) and vagrant 2.5%. The 62.5% of the patients were unemployed (CI95%45.80-77.27), a 10% had a criminal record (CI95%2.79- 23.66), and the 7.5% had been in prison. The 92.5% were heterosexual, 2.5% men had had sex with men and 5% were bisexual. Only 10% had completed secondary education. The 80% admission by emergencies (CI95% 64.35- 90.95) and 45% by infectious cause (CI95%29.26-61.51). The events associated with addiction were: manifestations of central nervous system: 12.5% (CI95%4.19-26.80); abstinence and tremor 7.5% each and psychomotor hyperactivity, delirium, a sign of neurological focus and rigidity 5 percent each. The 100% had any comorbidities; smoking 80%, depression 12.82% and alcoholism 57.5%, among others; 5 patients presented sexually transmitted diseases (4 HIV, 2 HCV and 1 pediculus pubis). There was no hospital mortality. Conclusion: The hospitalized addicted patient is characterized by being young, belonging to a social group unprotected, unemployed and uneducated, having poli-addiction, with high burden of comorbid and of hospitalization, mainly by infectious complications.Fil: Santolín, María. Hospital Luis Lagomaggiore (Mendoza, Argentina). Servicio de Clínica MédicaFil: Zabala, P.. Hospital Luis Lagomaggiore (Mendoza, Argentina). Servicio de Clínica MédicaFil: Salomón, Susana Elsa. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Departamento de Medicina InternaFil: Carena, José Alberto. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Departamento de Medicina Intern

Analysis of the sporting context of Spanish female competitive cyclists and triathletes

El objetivo del presente estudio fue conocer y comparar las características psicosociales de las ciclistas y triatletas federadas en España estableciendo unas pautas de actuación que mejoren su situación en el deporte de competición. Se analizan dos deportes con aspectos comunes (uso de la bicicleta en competición, participantes que realizan ambos deportes…) y diferenciadores (deporte clásico vs deporte moderno), con el objeto de descubrir las posibles diferencias y/o similitudes entre ambos. En este estudio descriptivo participaron 80 ciclistas y 126 triatletas. Se determinó el perfil sociodemográfico promedio de las ciclistas y triatletas mediante 2 cuestionarios semiestructurados que permitieron definirlas como deportistas a) amateurs con tendencia competidora, b) iniciadas a una edad tardía en su especialidad deportiva, c) con una amplia experiencia deportiva, d) con un nivel alto de estudios completado o en curso, y e) pertenecientes a un estrato social medio. Tras el análisis de los resultados creemos que se hace necesario un cambio en la política deportiva de las federaciones deportivas así como iniciativas tendentes a la mejora de las condiciones de competición de estas deportistasThe aim of this study was to know and compare the psychosocial characteristics from Spanish under-licence female cyclists and triathletes establishing guidelines to improve their situation in competitive sport. We compared two sports with common aspects (use of a bicycle in competition, participants who participate in both sports...) and differentiating ones (classic sport vs. modern), with the aim of uncover potential differences and/or similarities between the two. 80 cyclists and 126 triathletes took part in this descriptive study. We determined the average socio-demographic profile of cyclists and triathletes through 2 semistructured questionnaires. The athletes’ average socio-sporting profile was defined as a) amateur with a competitive tendency; b) who became specialised in the sport at a late age; c) having vast sporting experience; d) having completed, or completing, a high level of education; e) belonging to the middle class. We believe a change in politics in sports federations is needed, as are initiatives to improve competition conditions for these athletesEstudio financiado por el Ministerio de Educación y ciencia (AP2009-0529) y por la Real Federación Española de Ciclism

Carbohydrates alone or mixing with beef or whey protein promote similar training outcomes in resistance training males: A double blind, randomized controlled clinical trial

Beef powder is a new high-quality protein source scarcely researched relative to exercise performance. The present study examined the impact of ingesting hydrolyzed beef protein, whey protein, and carbohydrate on strength performance (1RM), body composition (via plethysmography), limb circumferences and muscular thickness (via ultrasonography), following an 8-week resistance-training program. After being randomly assigned to one of the following groups: Beef, Whey, or Carbohydrate, twenty four recreationally physically active males (n = 8 per treatment) ingested 20 g of supplement, mixed with orange juice, once a day (immediately after workout or before breakfast). Post intervention changes were examined as percent change and 95% CIs. Beef (2.0%, CI, 0.2–2.38%) and Whey (1.4%, CI, 0.2–2.6%) but not Carbohydrate (0.0%, CI, -1.2–1.2%) increased fat-free mass. All groups increased vastus medialis thickness: Beef (11.1%, CI, 6.3–15.9%), Whey (12.1%, CI, 4.0, -20.2%), Carbohydrate (6.3%, CI, 1.9–10.6%). Beef (11.2%, CI, 5.9–16.5%) and Carbohydrate (4.5%, CI, 1.6–7.4%), but not Whey (1.1%, CI, -1.7–4.0%), increased biceps brachialis thickness, while only Beef increased arm (4.8%, CI, 2.3–7.3%) and thigh (11.2%, 95%CI 0.4–5.9%) circumferences. Although the three groups significantly improved 1RM Squat (Beef 21.6%, CI 5.5–37.7%; Whey 14.6%, CI, 5.9–23.3%; Carbohydrate 19.6%, CI, 2.2–37.1%), for the 1RM bench press the improvements were significant for Beef (15.8% CI 7.0–24.7%) and Whey (5.8%, CI, 1.7–9.8%) but not for carbohydrate (11.4%, CI, -0.9-23.6%). Protein-carbohydrate supplementation supports fat-free mass accretion and lower body hypertrophy. Hydrolyzed beef promotes upper body hypertrophy along with similar performance outcomes as observed when supplementing with whey isolate or maltodextrin

Magnetic phenomena in 5d transition metal nanowires

We have carried out fully relativistic full-potential, spin-polarized, all-electron density-functional calculations for straight, monatomic nanowires of the 5d transition and noble metals Os, Ir, Pt and Au. We find that, of these metal nanowires, Os and Pt have mean-field magnetic moments for values of the bond length at equilibrium. In the case of Au and Ir, the wires need to be slightly stretched in order to spin polarize. An analysis of the band structures of the wires indicate that the superparamagnetic state that our calculations suggest will affect the conductance through the wires -- though not by a large amount -- at least in the absence of magnetic domain walls. It should thus lead to a characteristic temperature- and field dependent conductance, and may also cause a significant spin polarization of the transmitted current.Comment: 7 pages, 5 figure

Spontaneous magnetization of aluminum nanowires deposited on the NaCl(100) surface

We investigate electronic structures of Al quantum wires, both unsupported and supported on the (100) NaCl surface, using the density-functional theory. We confirm that unsupported nanowires, constrained to be linear, show magnetization when elongated beyond the equilibrium length. Allowing ions to relax, the wires deform to zig-zag structures with lower magnetization but no dimerization occurs. When an Al wire is deposited on the NaCl surface, a zig-zag geometry emerges again. The magnetization changes moderately from that for the corresponding unsupported wire. We analyse the findings using electron band structures and simple model wires.Comment: submitted to PHys. Rev.

A multi-ingredient containing carbohydrate, proteins L-glutamine and L-carnitine attenuates fatigue perception with no effect on performance, muscle damage or immunity in soccer players

We investigated the effects of ingesting a multi-ingredient (53g carbohydrate, 14.5g whey protein, 5g glutamine, 1.5g L-carnitine-L-tartrate) supplement, carbohydrate only, or placebo on intermittent performance, perception of fatigue, immunity, and functional and metabolic markers of recovery. Sixteen amateur soccer players ingested their respective treatments before, during and after performing a 90-min intermittent repeated sprint test. Primary outcomes included time for a 90-min intermittent repeated sprint test (IRS) followed by eleven 15 m sprints. Measurements included creatine kinase, myoglobin, interleukine-6, Neutrophil; Lymphocytes and Monocyte before (pre), immediately after (post), 1h and 24h after exercise testing period. Overall, time for the IRS and 15 m sprints was not different between treatments. However, the perception of fatigue was attenuated (P<0.001) for the multi-ingredient (15.9±1.4) vs. placebo (17.8±1.4) but not for the carbohydrate (17.0±1.9) condition. Several changes in immune/inflammatory indices were noted as creatine kinase peaked at 24h while Interleukin-6 and myoglobin increased both immediately after and at 1h compared with baseline (P<0.05) for all three conditions. However, Myoglobin (P<0.05) was lower 1h post-exercise for the multi-ingredient (241.8±142.6 ng·ml-1) and CHO (265.4±187.8 ng·ml-1) vs. placebo (518.6±255.2 ng·ml-1). Carbohydrate also elicited lower neutrophil concentrations vs. multi-ingredient (3.9±1.5 109/L vs. 4.9±1.8 109/L, P = 0.016) and a reduced (P<0.05) monocytes count (0.36±0.09 109/L) compared to both multi-ingredient (0.42±0.09 109/L) and placebo (0.42±0.12 109/L). In conclusion, multi-ingredient and carbohydrate supplements did not improve intermittent performance, inflammatory or immune function. However, both treatments did attenuate serum myoglobin, while only carbohydrate blunted post-exercise leukocytosis

The effect of sodium fluorescein angiography on erythrocyte properties

© 1998 – IOS Press. All rights reservedSodium fluorescein angiography is a widely used routine ophthalmological diagnostic procedure which enables the study of chorioretinal microcirculation and consists of the injection of sodium fluorescein into the systemic bloodstream. The aim of the present study was to evaluate whether or not fluorescein interferes with erythrocyte properties during the angiographic procedure. In a group of 37 patients, 26 with non-insulin-dependent diabetes mellitus (DM) with and without retinopathy, and 11 without diabetes mellitus (non-DM) although affected by other ophthalmological diseases, all undergoing routine angiography, blood samples were drawn before (T0) and 30 min (T30) after fluorescein injection. The erythrocyte aggregation index (EAI), membrane lipid fluidity and erythrocyte acetylcholinesterase activity were determined in both groups. After fluorescein injection there was no statistical change in EAI and erythrocyte membrane fluidity in either group. Erythrocyte acetylcholinesterase activity, a marker of membrane protein integrity, decreased significantly (p < 0:01) in the DM group. Membrane lipid fluidity did not change with fluorescein injection, however, (i) in the DM group erythrocyte membranes became more rigid than in the non-DM (DPH: p < 0:01); (ii) EAI and membrane lipid fluidity became significantly correlated (r = 0:6263, p < 0:05) in non-DM patients at T30. In conclusion, fluorescein administration for angiographic procedures seems to interact with erythrocyte membrane, namely, in diabetic patients, which may interfere with the blood flow in the microcirculation