Monte Carlo simulation of a LSC based on stacked layers of fiber arrays with core-coating different absorbing properties.

In this work, a Monte Carlo ray-tracing model for the simulation and optimization of a fiber Luminescent Solar Concentrator (LSC) based on stacked layers of fiber arrays is developed and validated. The fiber LSC efficiency improvements are compared against a conventional planar LSC. We developed a new model to analyze the performance of different configurations of bulk-doped fibers and fibers constituted by a doped coating and a passive core. These configurations are analyzed also varying fiber packing geometry diameters, and length. Due to the exceptionally low absorption coefficient of the silica fibers (αwg ≈ 10-4 cm-1), concentration factors of up to 1.9 are predicted when dimensions are scaled over 1 m2, which improve more than twice the maximum concentration factor ever reported. These results serve as a preliminary theoretical study for the future development of a new LSC design based on flexible silica micro-fibers coated with Si-QDs doped poly(lauryl methacrylate) (PLMA) layers.

Continuous fiberizing by laser melting (Cofiblas): Production of highly flexible glass nanofibers with effectively unlimited length.

The development of nanofibers is expected to foster the creation of outstanding lightweight nanocomposites and flexible and transparent composites for applications such as optoelectronics. However, the reduced length of existing nanofibers and nanotubes limits mechanical strengthening and effective manufacturing. Here, we present an innovative method that produces glass nanofibers with lengths that are, effectively, unlimited by the process. The method uses a combination of a high-power laser with a supersonic gas jet. We describe the experimental setup and the physical processes involved, and, with the aid of a mathematical simulation, identify and discuss the key parameters which determine its distinctive features and feasibility. This method enabled the production of virtually unlimited long, solid, and nonporous glass nanofibers that display outstanding flexibility and could be separately arranged and weaved.

Fabrication and Deposition of Copper and Copper Oxide Nanoparticles by Laser Ablation in Open Air.

The proximity of the "post-antibiotic era", where infections and minor injuries could be a cause of death, there are urges to seek an alternative for the cure of infectious diseases. Copper nanoparticles and their huge potential as a bactericidal agent could be a solution. In this work, Cu and Cu oxide nanoparticles were synthesized by laser ablation in open air and in argon atmosphere using 532 and 1064 nm radiation generated by nanosecond and picosecond Nd:YVO4 lasers, respectively, to be directly deposited onto Ti substrates. Size, morphology, composition and the crystalline structure of the produced nanoparticles have been studied by the means of field emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM), the energy dispersive spectroscopy of X-rays (EDS), selected area electron diffraction (SAED) and X-ray diffraction (XRD). The UV-VIS absorbance of the thin layer of nanoparticles was also measured, and the antibacterial capacity of the obtained deposits tested against Staphylococcus aureus. The obtained deposits consisted of porous coatings composed of copper and copper oxide nanoparticles interconnected to form chain-like aggregates. The use of the argon atmosphere contributed to reduce significantly the formation of Cu oxide species. The synthesized and deposited nanoparticles exhibited an inhibitory effect upon S. aureus.

Neurocardiovascular pathology in pre-manifest and early-stage Huntington's disease.

BACKGROUND AND PURPOSE: Cardiovascular events are a major cause of early death in the Huntington's disease (HD) population. Dysautonomia as well as deterioration of circadian rhythms can be detected early in the disease progression and can have profound effects on cardiac health. The aim of the present study was to determine if patients with HD and pre-manifest mutation carriers present a higher risk of cardiovascular disease than non-mutation-carrying controls. METHODS: This was a prospective, cross-sectional, multicentre study of 38 HD mutation carriers (23 pre-manifest and 15 early-stage patients) compared with 38 age- and gender-matched healthy controls. Clinical and epidemiological variables, including the main haematological vascular risk factors, were recorded. Ambulatory blood-pressure monitoring and carotid intima-media thickness (CIMT) measurement were performed to assess autonomic function and as target-organ damage markers. RESULTS: Most (63.2%) patients with HD (86.7% and 47.8%, respectively, of the early-stage and pre-manifest patients) were non-dippers compared with 23.7% of controls (P = 0.001). CIMT values were in the 75th percentile in 46.7% and 43.5%, respectively, of the early-stage and pre-manifest patients, whereas none of the controls presented pathological values (P = 0.001 and P = 0.006, respectively). Nocturnal non-dipping was significantly associated with CIMT values in patients (P = 0.002) but not in controls. CONCLUSIONS: These results suggest that higher cardiovascular risks and target-organ damage are present even in pre-manifest patients. Although larger studies are needed to confirm these findings, clinicians should consider these results in the cardiovascular management of patients with HD.

Síndrome de parkinsonismo-hiperpirexia / Parkinsonism hyperpyrexia syndrome

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Magnetic and structural properties of glass-coated Heusler-type microwires exhibiting martensitic transformation.

We have studied magnetic and structural properties of the Heusler-type Ni-Mn-Ga glass-coated microwires prepared by Tailor-Ulitovsky technique. As-prepared sample presents magnetoresistance effect and considerable dependence of magnetization curves (particularly magnetization values) on magnetic field attributed to the magnetic and atomic disorder. Annealing strongly affects the temperature dependence of magnetization and Curie temperature of microwires. After annealing of the microwires at 973 K, the Curie temperature was enhanced to about 280 K which is beneficial for the magnetic solid state refrigeration. The observed hysteretic anomalies on the temperature dependences of resistance and magnetization in the as-prepared and annealed samples are produced by the martensitic transformation. The magnetoresistance and magnetocaloric effects have been investigated to illustrate a potential technological capability of studied microwires.

Temblor ortostático secundario al uso recreativo de disolventes / Orthostatic tremor secondary to recreational use of solvents

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The high prevalence of impulse control behaviors in patients with early-onset Parkinson's disease: A cross-sectional multicenter study.

INTRODUCTION: In Parkinson's disease patients, impulse control disorders (ICDs) have been associated with younger age and early disease onset, yet the prevalence of ICDs in early-onset Parkinson's disease (EOPD) patients has yet to be studied. Thus, we set out to compare the prevalence of impulse control behaviors (ICBs) in a cohort of EOPD patients with that in age and gender matched healthy controls (HCs), as well as to analyze the association of these symptoms with the use of dopaminergic drugs and other clinical or demographic factors. METHODS: A cross-sectional, multicenter study was carried out on patients recruited from outpatient Movement Disorder Clinics, assessing ICBs using the short form of the Questionnaire for Impulsive-Compulsive Disorders in Parkinson's Disease (QUIP). In addition, depression and quality of life (QoL) were measured, along with other demographic and clinical variables. RESULTS: Of the 87 EOPD patients, 49 (58.3%) displayed an ICB, as did 28 of the 87 HCs (32.9%; p=0.001). Most of the EOPD patients that displayed an ICB (91.8%) were medicated with a dopamine agonist (DA) and accordingly, DA treatment was associated with a 7-fold increased risk of developing an ICB. Patients with ICBs had a higher depression score and a worse QoL. CONCLUSIONS: ICBs are much more prevalent in EOPD patients than in HCs and they are associated with DA intake, depression and a worse QoL.

Reaction time and rhythm of movement in Huntington's disease.

Huntington disease (HD) is characterized by several hyperkinesias though motor slowness is also another cardinal in this disease. In addition, self-paced timing movements are also disturbed in HD, which may also affect several rhythmic voluntary movements such as gait. Motor slowness can be measured with clinical scales such as the Unified Huntington's Disease Rating Scale (UHDRS) and timed tests, but also with the reaction time (RT) paradigm. We evaluated RT as a measure of motor slowness in 30 patients with genetically confirmed Huntington's disease and 24 control subjects. We also evaluated self-paced timing precision (SPTP) by applying a simple software program devised by our group. Clinical assessment was performed according to the UHDRS, including motor section, total functional capacity (TFC) and cognitive section (verbal fluency test, symbol digit, and Stroop test) The mean values obtained for RT and SPTP were statistically different in HD as compared with those from controls (p<0.0005). We observed a statistically significant correlation between RT and TFC scores (rs=-0.57, p<0.005 Spearman's correlation) and also between SPTP values and TFC scores (rs=-0.40, p<0.05 Spearman's correlation). In addition, RT and SPTP significantly correlated with cognitive scores (including digit symbol, verbal fluency and Stroop tests). Simple tests such as RT and SPTP provide an objective evaluation of motor impairment in HD yielding measures that correlate with clinical assessment and functional disability.

Determinants of survival and hospitalization in older, heart failure patients receiving home healthcare.

INTRODUCTION: Since reported evidence is both scarce and controversial, the objective of this study is to determine the risk factors involved in the prognosis of older patients with heart failure (HF) receiving home healthcare from primary care professionals. METHODS: Retrospective cohort community study was carried out in 52 primary healthcare centers in Barcelona (Spain). A follow-up was performed between January 2009 and December 2012 with 7461 HF patients aged >64years. Information was obtained from primary care electronic medical records containing clinical data, functional and cognitive status, total mortality, and hospital admissions for cardiovascular events. RESULTS: Mortality and hospitalization during follow-up were higher in older, HF patients who received home healthcare than those who did not (HR 1.39, 95% CI 1.22-1.58 and 1.92 95% CI 1.72-2.14, respectively). The most relevant determinants for mortality were male gender (HR 1.40, 95%CI 1.10-1.79), previous hospital admission for HF (HR 1.29 95%CI 1.05-1.60), and severe dependence in activities for daily living (ADL) (HR 1.33, 95%CI 1.06-1.67). In contrast, severely dependent ADL patients were not more frequently hospitalized as a consequence of cardiovascular events (0.97, 95% CI 0.77-1.23). CONCLUSIONS: Due to their greater comorbidity and age, mortality and hospitalization in patients requiring home healthcare were higher than those who did not. Among the HF patients receiving home care, mortality and hospital admissions were higher in men, older patients, and in those previously hospitalized for HF. Severe dependence in ADL determined a higher mortality but was not related to increased hospital admission rates.

Agonistas dopaminérgicos en la enfermedad de Parkinson / Dopaminergic agonists in Parkinson’s disease

Introducción: Los agonistas dopaminergicos no ergoticos (AD) son tratamientos útiles en la enfermedad de Parkinson (EP). Revisamos la farmacología, el grado de evidencia en cuanto a eficacia y tolerabilidad de pramipexol, ropinirol y rotigotina, y proponemos algunas recomendaciones para su uso en la practica clínica. Desarrollo: En el momento actual se dispone de formas de liberacion prolongada (LP) de pramipexol y ropinirol y de administración transdermica de rotigotina, que contribuyen a una mayor estabilidad plasmatica de los valores del fármaco. En la EP inicial los 3 fármacos mejoran de forma significativa las escalas de incapacidad de los pacientes, retrasan la aparición de discinesias y permiten retrasar la introducción de levodopa. En la EP avanzada reducen el tiempo off, mejoran la Unified Parkinson’s Disease Rating Scale (UPDRS) en on y en off y permiten reducir la dosis total de levodopa. Además, los 3 han sido capaces de inducir una mejora significativa en las escalas de la calidad de vida relacionada con la salud. Las formulas de LP han demostrado la no inferioridad frente a las de liberación inmediata, e incluso una mejor tolerabilidad (ropinirol). A pesar de su buen perfil de seguridad, entre los efectos adversos graves cabe destacar el trastorno de control de impulsos, cuya aparición puede ser precoz, y los accesos de sueño (sleep attacks). Aunque la terapia combinada no ha sido estudiada específicamente, algunas asociaciones (como la de apomorfina y otros AD) pueden ser beneficiosas. El cambio de un AD a otro es factible de un día para otro, aunque en los primeros días puede haber una sumación de efectos adversos dopaminergicos que debe tenerse en cuenta. La suspensión brusca del tratamiento con AD puede inducir un síndrome de deprivacion dopaminergica. La retirada de cualquier AD, en particular pramipexol, se ha asociado a aparición de apatía que puede ser grave. Conclusiones: Los nuevos AD no ergoticos constituyen una opción valida de tratamiento de la EP tanto inicial como avanzada. A pesar de su buen perfil de tolerabilidad, no están exentos de efectos adversos graves, que pueden tener un efecto atoplastico en la EP y que deben monitorizarse

Background: Non-ergoline dopamine agonists (DA) are effective treatments for Parkinson’s disease (PD). This review presents the pharmacology, evidence of efficacy and safety profile of pramipexole, ropinirole, and rotigotine, and practical recommendations are given regarding their use in clinical practice. Results: Extended-release formulations of pramipexole and ropinirole and transdermal continuous delivery rotigotine patches are currently available; these may contribute to stabilizing of plasma levels. In early PD, the three drugs significantly improve disability scales, delay time to dyskinesia and allow a later introduction of levodopa. In late PD they reduced total ’off’-time, improved Unified Parkinson’s Disease Rating Scale (UPDRS) in both ’on’ and ’off’ state and allowed a reduction in total levodopa dosage. A significant improvement in quality of life scales has also been demonstrated. Extended-release formulations have proved to be non-inferior to the immediate release formulations and are better tolerated (ropinirole). Despite a generally good safety profile, serious adverse events, such as impulse control disorder and sleep attacks, need to be routinely monitored. Although combination therapy has not been addressed in scientific literature, certain combinations, such as apomorphine and another DA, may be helpful. Switching from one DA to another is feasible and safe, although in the first days an overlap of dopaminergic side effects may occur. When treatment with DA is stopped abruptly, dopamine withdrawal syndrome may present. Suspending any DA, especially pramipexole, has been linked to onset of apathy, which may be severe. Conclusions: New non-ergotine DAs are a valuable option for the treatment of both early and late PD. Despite their good safety profile, serious adverse effects may appear; these effects may have a pathoplastic effect on the course of PD and need to be monitored

Dopaminergic agonists in Parkinson's disease.

BACKGROUND: Non-ergoline dopamine agonists (DA) are effective treatments for Parkinson's disease (PD). This review presents the pharmacology, evidence of efficacy and safety profile of pramipexole, ropinirole, and rotigotine, and practical recommendations are given regarding their use in clinical practice. RESULTS: Extended-release formulations of pramipexole and ropinirole and transdermal continuous delivery rotigotine patches are currently available; these may contribute to stabilising of plasma levels. In early PD, the three drugs significantly improve disability scales, delay time to dyskinesia and allow a later introduction of levodopa. In late PD they reduced total 'off'-time, improved Unified Parkinson's Disease Rating Scale (UPDRS) in both 'on' and 'off' state and allowed a reduction in total levodopa dosage. A significant improvement in quality of life scales has also been demonstrated. Extended-release formulations have proved to be non-inferior to the immediate release formulations and are better tolerated (ropinirole). Despite a generally good safety profile, serious adverse events, such as impulse control disorder and sleep attacks, need to be routinely monitored. Although combination therapy has not been addressed in scientific literature, certain combinations, such as apomorphine and another DA, may be helpful. Switching from one DA to another is feasible and safe, although in the first days an overlap of dopaminergic side effects may occur. When treatment with DA is stopped abruptly, dopamine withdrawal syndrome may present. Suspending any DA, especially pramipexole, has been linked to onset of apathy, which may be severe. CONCLUSIONS: New non-ergotine DAs are a valuable option for the treatment of both early and late PD. Despite their good safety profile, serious adverse effects may appear; these effects may have a pathoplastic effect on the course of PD and need to be monitored.

Effect of the current annealing (without and with tensile stress) on the soft magnetic behaviour of Fe73.5-x(Co0.5Ni0.5)xSi13.5B9Nb3Cu1 alloy ribbons (x = 2.5, 5 and 10).

Experimental data on microstructural (crystalline volume fraction, grain size) and magnetic (coercive field) properties in amorphous and nanocrystalline Fe73.5-x(Co0.5Ni0.5)xSi13.5B9Nb3Cu1 alloy ribbons (x = 2.5, 5 and 10) are presented. Nanocrystalline structure was developed by annealing the precursor amorphous ribbons by current annealing (CA) and stress-current-annealing (SA). Microstructural analysis of the treated ribbons using X-ray Diffraction showed a high content of amorphous phase in the bulk. In addition, substantial changes in the crystalline state such as grain size of the samples annealed at different conditions were observed. The alloy composition also affects greatly the grain size,: increasing the (Co,Ni) content leads to higher values of the average grain size. The evolutions of the coercive field with the two kinds of thermal treatment were analysed, allowing us to conclude that the addition of (Co,Ni) tends to reduce the magnetic softness character of the original material, while the treated SA samples show higher coercivities higher than those treated without by CA.

Three-dimensional bioactive glass implants fabricated by rapid prototyping based on CO(2) laser cladding.

Three-dimensional bioactive glass implants were produced by rapid prototyping based on laser cladding without using moulds. CO(2) laser radiation was employed to melt 45S5 and S520 bioactive glass particles and to deposit the material layer by layer following a desired geometry. Controlled thermal input and cooling rate by fine tuning of the processing parameters allowed the production of crack-free fully dense implants. Microstructural characterization revealed chemical composition stability, but crystallization during processing was extensive when 45S5 bioactive glass was used. Improved results were obtained using the S520 bioactive glass, which showed limited surface crystallization due to an expanded sintering window (the difference between the glass transition temperature and crystallization onset temperature). Ion release from the S520 implants in Tris buffer was similar to that of amorphous 45S5 bioactive glass prepared by casting in graphite moulds. Laser processed S520 scaffolds were not cytotoxic in vitro when osteoblast-like MC3T3-E1 cells were cultured with the dissolution products of the glasses; and the MC3T3-E1 cells attached and spread well when cultured on the surface of the materials.

Laser-assisted production of spherical TiO2 nanoparticles in water.

TiO(2) nanoparticles with controllable average diameter have been obtained by laser ablation in water. A monomode ytterbium doped fiber laser (YDFL) was used to ablate a metallic titanium target placed in deionized water. The resulting colloidal solutions were subjected to laser radiation to study the resizing effect. The crystalline phases, morphology and optical properties of the obtained nanoparticles were characterized by means of transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), x-ray energy dispersive spectroscopy (EDS) and UV-vis absorption spectroscopy. The colloidal suspensions produced consisting of titanium dioxide crystalline nanoparticles show almost perfect spherical shape with diameters ranging from 3 to 40 nm. The nanoparticles are polycrystalline and exhibit anatase as well as rutile phases.

[Apathy in Parkinson's disease]. / Apatía en la enfermedad de Parkinson.

INTRODUCTION: Apathy is a behavioural syndrome due to dysfunction of the process that gives rise to actions induced by external or personal stimuli. Apathy is very common in Parkinson's disease, with a prevalence that ranges between 16-48%. Three subtypes of apathy are currently accepted, which are anatomically and functionally different: cognitive, emotional and due to a deficit in auto-activation. Each of these subtypes is involved to a variable degree in the apathy of Parkinson's disease. The diagnosis is desupported by clinical, diagnostic and neuropsychological tests. The evaluation of the apathy must be done simultaneously along with with depression cognitive deficit. CONCLUSIONS: Apathy has become a very important symptom to bear in mind in Parkinson's disease patients as it has significant repercussions on the quality of life of the patient. It is very important to do a differential diagnosis with the depression and the cognitive deficit since the therapeutic approach is different. Specific scales to measure this symptom should be included in the evaluation protocols of cognitive function in Parkinson's disease.