Effect of the Photoexcitation Wavelength and Polarization on the Generated Heat by a Nd-Doped Microspinner at the Microscale.

Thermal control at small scales is critical for studying temperature-dependent biological systems and microfluidic processes. Concerning this, optical trapping provides a contactless method to remotely study microsized heating sources. This work introduces a birefringent luminescent microparticle of NaLuF4:Nd3+ as a local heater in a liquid system. When optically trapped with a circularly polarized laser beam, the microparticle rotates and heating is induced through multiphonon relaxation of the Nd3+ ions. The temperature increment in the surrounding medium is investigated, reaching a maximum heating of ≈5 °C within a 30 µm radius around the static particle under 51 mW laser excitation at 790 nm. Surprisingly, this study reveals that the particle's rotation minimally affects the temperature distribution, contrary to the intuitive expectation of liquid stirring. The influence of the microparticle rotation on the reduction of heating transfer is analyzed. Numerical simulations confirm that the thermal distribution remains consistent regardless of spinning. Instead, the orientation-dependence of the luminescence process emerges as a key factor responsible for the reduction in heating. The anisotropy in particle absorption and the lag between the orientation of the particle and the laser polarization angle contribute to this effect. Therefore, caution must be exercised when employing spinning polarization-dependent luminescent particles for microscale thermal analysis using rotation dynamics.

Light-to-Heat Conversion of Optically Trapped Hot Brownian Particles.

Anisotropic hybrid nanostructures stand out as promising therapeutic agents in photothermal conversion-based treatments. Accordingly, understanding local heat generation mediated by light-to-heat conversion of absorbing multicomponent nanoparticles at the single-particle level has forthwith become a subject of broad and current interest. Nonetheless, evaluating reliable temperature profiles around a single trapped nanoparticle is challenging from all of the experimental, computational, and fundamental viewpoints. Committed to filling this gap, the heat generation of an anisotropic hybrid nanostructure is explored by means of two different experimental approaches from which the local temperature is measured in a direct or indirect way, all in the context of hot Brownian motion theory. The results were compared with analytical results supported by the numerical computation of the wavelength-dependent absorption efficiencies in the discrete dipole approximation for scattering calculations, which has been extended to inhomogeneous nanostructures. Overall, we provide a consistent and comprehensive view of the heat generation in optical traps of highly absorbing particles from the viewpoint of the hot Brownian motion theory.

Encefalitis autoinmune seronegativa asociada a síndrome de Sjögren primario / Autoimmune seronegative encephalitis associated to primary Sjögren's disease

La encefalitis autoinmune es un trastorno inmunomediado que compromete distintos territorios del parénquima cerebral, involucrando frecuentemente la materia gris profunda o la corteza, con o sin compromiso de la materia blanca, meninges o médula espinal. Se asocia frecuentemente con enfermedades autoinmunes o paraneoplásicas, y constituye un reto diagnóstico. Reportamos el caso de una mujer de 55 años con antecedente de síndrome de Sjögren que consultó a Emergencias por cefalea y confusión. El líquido cefalorraquídeo (LCR) presentaba leucocitosis con neutrofilia. En la resonancia magnética nuclear (RMN) cerebral se evidenciaron múltiples imágenes de comportamiento restrictivo, de señal hiperintensa en T2 y FLAIR, a predominio córtico-subcortical a nivel occipital bilateral, hemisferio cerebeloso derecho y parietal derecho. Se descartaron infecciones y neoplasias. El panel de anticuerpos para encefalitis autoinmune aquaporina-4 y anti-MOG en LCR fue negativo. Recibió metilprednisolona endovenosa con mejoría progresiva de los síntomas.

Autoimmune encephalitis is an immune-mediated disorder that affects different areas of the brain parenchyma, often involving deep gray matter or the cortex, with or without involvement of white matter, meninges, or spinal cord. It is frequently associated with autoimmune or paraneoplastic diseases and is a diagnostic challenge. We report the case of a 55-year-old woman with history of Sjögren's syndrome who presented to the emergency department with headache and episodes of confusion. Cerebrospinal fluid (CSF) analysis showed leukocytosis with neutrophilia. Brain MRI revealed multiple restricted diffusion lesions with hyperintense signal on T2 and FLAIR sequences, predominantly in the bilateral occipital region, right cerebellar hemisphere, and right parietal region. Infections and neoplasms were ruled out. The panel of antibodies for autoimmune encephalitis, including Aquaporin-4 and anti-MOG in CSF, was negative. She received intravenous methylprednisolone, leading to symptom improvement.

Electrothermoplasmonic flow in gold nanoparticles suspensions: Nonlinear dependence of flow velocity on aggregate concentration.

Efficient mixing and pumping of liquids at the microscale is a technology that is still to be optimized. The combination of an AC electric field with a small temperature gradient leads to a strong electrothermal flow that can be used for multiple purposes. Combining simulations and experiments, an analysis of the performance of electrothermal flow is provided when the temperature gradient is generated by illuminating plasmonic nanoparticles in suspension with a near-resonance laser. Fluid flow is measured by tracking the velocity of fluorescent tracer microparticles in suspension as a function of the electric field, laser power, and concentration of plasmonic particles. Among other results, a non-linear relationship is found between the velocity of the fluid and particle concentration, which is justified in terms of multiple scattering-absorption events, involving aggregates of nanoparticles, that lead to enhanced absorption when the concentration is raised. Simulations provide a description of the phenomenon that is compatible with experiments and constitute a way to understand and estimate the absorption and scattering cross-sections of both dispersed particles and/or aggregates. A comparison of experiments and simulations suggests that there is some aggregation of the gold nanoparticles by forming clusters of about 2-7 particles, but no information about their structure can be obtained without further theoretical and experimental developments. This nonlinear behavior could be useful to get very high ETP velocities by inducing some controlled aggregation of the particles.

Intervention by a clinical pharmacist carried out at discharge of elderly patients admitted to the internal medicine department: influence on readmissions and costs.

BACKGROUND: Patient education on pharmacological treatment could reduce readmissions. Our objective was to carry out a pharmacist intervention focused on providing information about high-risk medications to chronic patients and to analyse its influence on readmissions and costs. METHODS: A single-centre study with an intervention group and a retrospective control group was conducted. The intervention was carried out in all polymedicated patients ≥ 65 years who were admitted to internal medicine and signed the informed consent between June 2017 and February 2018. Patients discharged to nursing homes or long-term hospitals were excluded. The control group were all the patients who were admitted during the same months of 2014 who met the same inclusion criteria. The patients were classified according to the HOSPITAL score as having a low, intermediate, or high risk of potentially avoidable readmission. Outcome measures were 30-day readmission and cost data. To analyse the effect of the intervention on readmission, a logistic regression was performed. RESULTS: The study included 589 patients (286 intervention group; 303 control group). The readmission rate decreased from 20.13% to 16.43% in the intervention group [OR = 0.760 95% CI (0.495-1.166); p = 0.209)]. The incremental cost for the intervention to prevent one readmission was €3,091.19, and the net cost saving was €1,301.26. In the intermediate- and high-risk groups, readmissions were reduced 10.91% and 10.00%, and the net cost savings were €3,3143.15 and €3,248.71, respectively. CONCLUSIONS: The pharmacist intervention achieved savings in the number of readmissions, and the net cost savings were greater in patients with intermediate and high risks of potentially avoidable readmission according to the HOSPITAL score.

El rol de la universidad en la prevención de la obesidad / The role of the university in the prevention of obesity

Introducción: La obesidad es la enfermedad crónica no transmisible más prevalente. El aumento de la prevalencia de esta enfermedad está asociado con la edad, razón por la cual los estudiantes universitarios son un grupo importante, el cual puede ser influenciado por programas de bienestar universitario. Materiales y Métodos: Articulo de reflexión, que discute las políticas colombianas y estrategias para la prevención de la obesidad y las enfermedades cardiovasculares. Resultados: Literatura muestra que hay puntos críticos aplicables en la prevención de la obesidad y las enfermedades cardiovasculares en la comunidad universitaria. Estos puntos incluyen pobre participación de prevención de universidades, inadecuada articulación de sectores involucrados para resolver deficiencias del sistema y así esperar mejores desenlaces en la comunidad. Discusión: Pese al conocimiento de estrategias que favorecen la actividad física en la población universitaria y población general, no hay una red articulada entre las universidades y el gobierno que permitan generar impacto en la prevención de enfermedad cardiovascular y obesidad. Se requiere participación de universidades (bienestar universitario), estudiantes y gobernantes para promover y ejecutar programas y políticas sostenibles a largo plazo. Conclusiones: Pese a la existencia de leyes y normas que regulan el bienestar universitario en Colombia, no existen intervenciones eficaces para la prevención de la obesidad. Se deben intervenir grupos en riesgo, así como adecuar espacios apropiados para la alimentación y realización de actividad física. Estas reformas implican la participación articulada de estudiantes, personal administrativo y líderes políticos, en coordinación con los centros de bienestar universitario.

Introduction: Obesity is the most prevalent non-communicable chronic disease. The increased prevalence of the disease is associated with early age, due to this, college students are an important group, which can be influenced by student welfare programs. Materials and Methods: A reflection article was prepared, which discusses the Colombian policies and strategies for the prevention of obesity and cardiovascular disease in this population. Results: Literature shows that there are critical points applicable in prevention of obesity and cardiovascular disease in the college community. These points include poor participation of academic institutions prevention, inadequate articulation of sectors involved to resolve deficiencies in the system and thus expect better outcomes in the community. Discussion: Despite the knowledge of strategies that promote physical activity in the student population and the general population, there is an articulated network between universities and the government to allow an impact in the prevention of cardiovascular disease and obesity. Participation of colleges (Welfare programs), students and leaders to promote and implement sustainable programs and policies over time is required. Conclusions: Despite the existence of laws and regulations governing the academic institutions in Colombia, there are no effective obesity prevention interventions. It should involve risk groups and adapt appropriate spaces for food and doing physical activity. These reforms involve the coordinated participation of students, staff and political leaders, in coordination with welfare programs.

Systolic heart murmur as first manifestation of high output heart failure due to the vein of galen malformation.

The vein of Galen aneurysmal malformation (VGAM) is an extremely rare arterio-venous malformation. The VGAM clinical manifestations vary depending on the magnitude of vascular compromise and the age at initial presentation. Neonates typically present with severe congestive heart failure. Here we present a case in which a systolic heart murmur was the first manifestation of high output heart failure due to a VGAM.

Systolic heart murmur as first manifestation of high output heart failure due to the vein of galen malformation / Soplo sistólico como primera manifestación de insuficiencia cardiaca de gasto alto secundaria a malformación de la vena de Galeno

The vein of Galen aneurysmal malformation (VGAM) is an extremely rare arteriovenous malformation. The VGAM clinical manifestations vary depending on the magnitude of vascular compromise and the age at initial presentation. Neonates typically present with severe congestive heart failure. Here we present a case in which a systolic heart murmur was the first manifestation of high output heart failure due to a VGAM.

Las malformaciones de la vena cerebral de Galeno (MVG) son extremadamente raras. Sus manifestaciones clínicas varían dependiendo de la magnitud del compromiso vascular y la edad inicial de presentación. En neonatos, típicamente se presenta con una insuficiencia cardiaca congestiva grave. Se presenta un caso en el cual un soplo sistólico cardiaco fue la primera manifestación de una insuficiencia cardíaca de gasto alto secundaria a una malformación aneurismática de la vena de Galeno.