Elements of Weight Management Among Pre-Kidney Transplant Candidates: The Patient Perspective.

Obesity and related comorbidities heighten risks for complications in kidney transplant settings. While pre-transplant patients often have access to nutrition counseling and health support, literature is limited on patients' perceptions of weight and motivation to lose weight prior to transplantation. We conducted a survey among ≥18-year-old patients on the kidney transplant waitlist at a single center. Questions addressed weight perception, motivation for weight loss, available resources, and engagement in physical activity. Medical records provided demographic and clinical data. Statistical tests analyzed quantitative data, while free-text responses were thematically grouped and described. Of 1055 patients, 291 responded and were matched with demographic data. Perceived weight changes correlated with actual changes in body mass index (BMI) (<24.9) were more receptive to weight center resources (<30 kg/m2) are most interested in weight loss resources and demonstrate motivation. Furthermore, pre-transplant nutrition counseling correlates with healthier behaviors. Integrating patients' perspectives enhances pre-transplant protocols by encouraging active involvement in health decisions.

Geospatial mapping of surgical systems for earthquake emergency planning in Guerrero, Mexico: an ecological study.

Background: Accessibility to surgical services can impact earthquake preparedness and response. We aimed to estimate the population with timely access to surgical care in Guerrero, a Mexican state with high tectonic activity, and identify populations at risk in the event of an earthquake. Methods: We conducted an ecological study using open government data. We extracted data from Guerrero municipalities regarding their earthquake risk, social vulnerability, social inequality, marginalisation, and resilience indices. The latest combines municipalities' resistance to unexpected events and capacity to maintain optimal functionality without immediate federal or international support. Geographical coordinates of active public and private surgical facilities in Guerrero were combined with ancillary spatial data on roads and municipalities' population density to estimate population coverage within 30-min and 1-h driving time to surgical facilities in Redivis. We built an ordered beta regression model for each driving time estimate. Findings: We identified 25 public and 16 private facilities capable of providing surgical care in Guerrero. The population with access to facilities with surgical capacity within 30 min and 1-h driving times were 48.4% and 69.1%, respectively. We found that municipalities with very high levels of earthquake risk, social vulnerability, social inequality, and marginalisation, and very low levels of resilience had decreased coverage. In the multivariable analysis, the resilience index was statistically significant only for the 30-min model, with an effect size of 0.524 (95% CI 0.082, 1.089). Interpretation: Access to surgical care remains unequally distributed in Guerrero municipalities at the highest risk for earthquakes. Municipalities' resilience was the most significant predictor of higher surgical care coverage in 30-min driving time. Our study provides insights on how surgical system strengthening can enhance earthquake emergency disaster planning. Funding: No funding.

Availability of laparoscopic surgery in Mexico's public health system: a nationwide retrospective analysis.

Background: Laparoscopic surgery remains limited in low-resource settings. We aimed to examine its use in Mexico and determine associated factors. Methods: By querying open-source databases, we conducted a nationwide retrospective analysis of three common surgical procedures (i.e., cholecystectomies, appendectomies, and inguinal hernia repairs) performed in Mexican public hospitals in 2021. Procedures were classified as laparoscopic based on ICD-9 codes. We extracted patient (e.g., insurance status), clinical (e.g., anaesthesia technique), and geographic data (e.g., region) from procedures performed in hospitals and ambulatories. Multivariable analysis with random forest modelling was performed to identify associated factors and their importance in adopting laparoscopic approach. Findings: We included 97,234 surgical procedures across 676 public hospitals. In total, 16,061 (16.5%) were performed using laparoscopic approaches, which were less common across all procedure categories. The proportion of laparoscopic procedures per 100,000 inhabitants was highest in the northwest (22.2%, 16/72) while the southeast had the lowest (8.3%, 13/155). Significant factors associated with a laparoscopic approach were female sex, number of municipality inhabitants, region, anaesthesia technique, and type of procedure. The number of municipality inhabitants had the highest contribution to the multivariable model. Interpretation: Laparoscopic procedures were more commonly performed in highly populated, urban, and wealthy northern areas. Access to laparoscopic techniques was mostly influenced by the conditions of the settings where procedures are performed, rather than patients' non-modifiable characteristics. These findings call for tailored interventions to sustainably address equitable access to minimally invasive surgery in Mexico. Funding: None.

Estimating the economic impact of interpersonal violence in Mexico in 2021: projecting three hypothetical scenarios for 2030.

Objective: To calculate the economic impact of violence across Mexico in 2021 and project costs for 2021-2030. Methods: Incidence data was obtained from the Executive Secretariat of the National Public Security System, (SESNSP), National Population Council (CONAPO), National Institute of Statistics and Geography (INEGI), and the National Survey of Victimization and Perception of Public Safety (ENVIPE). Our model incorporates incidence estimates of the costs of events associated with violence (e.g., homicides, hospitalizations, rapes, extortions, robbery, etc). Results: The economic impact of crime and violence in Mexico for the year 2021 has been estimated at about $192 billion US dollars, which corresponds to 14.6% of the national GDP. By reducing violence 50% by 2030, we estimate savings of at least US$110 billion dollars. This represents a saving of US$1 376 372 for each company and more than US$66 771 for each Mexican. Conclusion: Violence and homicides have become one of the most pressing public health and economic concerns for their effect on health, development, and economic growth. Due to low cost and high impact, prevention is the most efficient way to respond to crime and violence while also being an essential component of sustainable strategies aimed at improving citizen security.

Estimating the economic impact of interpersonal violence in Mexico in 2021: projecting three hypothetical scenarios for 2030

[ABSTRACT]. Objective. To calculate the economic impact of violence across Mexico in 2021 and project costs for 2021–2030. Methods. Incidence data was obtained from the Executive Secretariat of the National Public Security System, (SESNSP), National Population Council (CONAPO), National Institute of Statistics and Geography (INEGI), and the National Survey of Victimization and Perception of Public Safety (ENVIPE). Our model incorporates incidence estimates of the costs of events associated with violence (e.g., homicides, hospitalizations, rapes, extortions, robbery, etc). Results. The economic impact of crime and violence in Mexico for the year 2021 has been estimated at about $192 billion US dollars, which corresponds to 14.6% of the national GDP. By reducing violence 50% by 2030, we estimate savings of at least US$110 billion dollars. This represents a saving of US$1 376 372 for each com- pany and more than US$66 771 for each Mexican. Conclusion. Violence and homicides have become one of the most pressing public health and economic concerns for their effect on health, development, and economic growth. Due to low cost and high impact, prevention is the most efficient way to respond to crime and violence while also being an essential component of sustainable strategies aimed at improving citizen security.

[RESUMEN]. Objetivo. Calcular el impacto económico de la violencia en el 2021 en todo México y proyectar sus costos para el período 2021–2030. Métodos. Los datos de incidencia se obtuvieron del Secretariado Ejecutivo del Sistema Nacional de Segu- ridad Pública (SESNSP), el Consejo Nacional de Población (CONAPO), el Instituto Nacional de Estadística y Geografía (INEGI), y la Encuesta Nacional de Victimización y Percepción sobre Seguridad Pública (ENVIPE). Nuestro modelo incorpora estimaciones de la incidencia de los costos de los eventos asociados a la violencia (por ejemplo, homicidios, hospitalizaciones, violaciones, extorsiones, robos, etc.) Resultados. Se ha estimado que el impacto económico del delito y la violencia en México para el año 2021 es de alrededor de US$ 192 000 millones de dólares estadounidenses, lo que corresponde al 14,6% del PIB nacional. Estimamos que una reducción del 50% de la violencia para el 2030 supondría un ahorro de al menos US$110 000 millones. Esto representa un ahorro de US$1 376 372 para cada empresa y de más de US$66 771 para cada mexicano. Conclusión. La violencia y los homicidios se han convertido en una de las preocupaciones económicas y de salud pública más apremiantes por su efecto sobre la salud, el desarrollo y el crecimiento económico. Debido a su bajo costo y alto impacto, la prevención es la forma más eficiente de responder al delito y la violencia, al tiempo que es un componente esencial de las estrategias sostenibles dirigidas a mejorar la seguridad ciudadana.

[RESUMO]. Objetivo. Estimar o impacto econômico da violência no México em 2021 e fazer a projeção de custos para o período 2021–2030. Métodos. Os dados de incidência da violência no país foram obtidos da Secretaria Executiva do Sistema Nacional de Segurança Pública (SESNSP), do Conselho Nacional de População (CONAPO), do Instituto Nacional de Estatística e Geografia (INEGI) e da Pesquisa Nacional de Vitimização e Percepção de Segu- rança Pública (ENVIPE). O modelo incorpora estimativas de incidência de custos de eventos associados à violência (como homicídios, internações hospitalares, estupros, extorsões e roubos). Resultados. O impacto econômico da criminalidade e da violência no México foi estimado em torno de US$192 bilhões em 2021, o que equivale a 14,6% do produto interno bruto (PIB) nacional. Estima-se que reduzir a violência em 50% até 2030 pode resultar em uma economia de US$ 110 bilhões ou mais, o que representa uma redução de gastos de US$1 376 372 para cada empresa e de mais de US$66 771 para cada cidadão do México. Conclusão. A violência e os homicídios são um dos problemas econômicos e de saúde pública mais pre- mentes por suas consequências à saúde, ao desenvolvimento e ao crescimento econômico do país. Devido ao seu baixo custo e alto impacto, a prevenção é a forma mais eficiente de combater a criminalidade e a violência, além de ser um componente essencial de qualquer estratégia sustentável para aumentar a segu- rança da população.

Outcomes of perineal wound closure techniques after abdominoperineal resections in rectal cancer: an NSQIP propensity score matched study.

Perineal defects following abdominoperineal resections (APRs) for rectal cancer may require myocutaneous or omental flaps depending upon anatomic, clinical and oncologic variables. However, studies comparing their efficacy have shown contradictory results. We aim to compare postoperative complication rates of APR closure techniques in rectal cancer using propensity score-matching. The American College of Surgeons Proctectomy Targeted Data File was queried from 2016 to 2019. The study population was defined using CPT and ICD-10 codes for patients with rectal cancer undergoing APR, stratified by repair technique. Perioperative demographic and oncologic variables were controlled for by propensity-score matching. Multivariate logistic regression analysis was performed for wound and major complications (MCs). Of the 3291 patients included in the study, 85% underwent primary closure (PC), 8.3% rectus abdominis myocutaneous (RAM) flap, 4.9% pedicled omental flap with PC, and 1.9% lower extremity (LE) flap repair. Primary closure rates were significantly higher for patients with stage T1 and T2 tumors (p < 0.001). RAM and LE flaps were most used with multi-organ resections, 24% and 25%, respectively (p < 0.001). Similarly, cases with T4 tumors used these flaps more frequently, 30% and 40%, respectively (p < 0.001). After propensity score matching for comorbidities and oncologic variables, there was no significant difference in 30-day postoperative wound or MC rates between perineal closure techniques. The complication rates of the different closure techniques are comparable when tumor stage is considered. Therefore, tumor staging and concurrent procedures should guide clinical decision making regarding the appropriate use of each technique.

Rethinking referral systems in rural chiapas: A mixed methods study.

Background: Despite the assurance of universal health coverage, large disparities exist in access to surgery in the state of Chiapas. The purpose of this study was to determine the effectiveness of the surgical referral system at hospitals operated by the Ministry of Health in Chiapas. Methods: 13 variables were extracted from surgical referrals data from three public hospitals in Chiapas over a three-year period. Interviews were performed of health care workers involved in the referral system and surgical patients. The quantitative and qualitative data was analyzed convergently and reported using a narrative approach. Findings: In total, only 47.4% of referred patients requiring surgery received an operation. Requiring an elective, gynecological, or orthopedic surgery and each additional surgery cancellation were significantly associated with lower rates of receiving surgery. The impact of gender and surgical specialty, economic fragility of farmers, dependence upon economic resources to access care, pain leading people to seek care, and futility leading patients to abandon the public system were identified as main themes from the mixed methods analysis. Interpretation: Surgical referral patients in Chiapas struggle to navigate an inefficient and expensive system, leading to delayed care and forcing many patients to turn to the private health system. These mixed methods findings provide a detailed view of often overlooked limitations to universal health coverage in Chiapas. Moving forward, this knowledge must be applied to improve referral system coordination and provide hospitals with the necessary workforce, equipment, and protocols to ensure access to guaranteed care. Funding: Harvard University and the Abundance Fund provided funding for this project. Funding sources had no role in the writing of the manuscript or decision to submit it for publication.

Estimating the economic impact of interpersonal violence in Mexico in 2021: projecting three hypothetical scenarios for 2030 / Estimación del impacto económico de la violencia interpersonal en México en el 2021: proyección de tres escenarios hipotéticos para el 2030 / Estimativa do impacto econômico da violência interpessoal no México em 2021: projeção de três cenários hipotéticos para 2030

ABSTRACT Objective. To calculate the economic impact of violence across Mexico in 2021 and project costs for 2021-2030. Methods. Incidence data was obtained from the Executive Secretariat of the National Public Security System, (SESNSP), National Population Council (CONAPO), National Institute of Statistics and Geography (INEGI), and the National Survey of Victimization and Perception of Public Safety (ENVIPE). Our model incorporates incidence estimates of the costs of events associated with violence (e.g., homicides, hospitalizations, rapes, extortions, robbery, etc). Results. The economic impact of crime and violence in Mexico for the year 2021 has been estimated at about $192 billion US dollars, which corresponds to 14.6% of the national GDP. By reducing violence 50% by 2030, we estimate savings of at least US$110 billion dollars. This represents a saving of US$1 376 372 for each company and more than US$66 771 for each Mexican. Conclusion. Violence and homicides have become one of the most pressing public health and economic concerns for their effect on health, development, and economic growth. Due to low cost and high impact, prevention is the most efficient way to respond to crime and violence while also being an essential component of sustainable strategies aimed at improving citizen security.

RESUMEN Objetivo. Calcular el impacto económico de la violencia en el 2021 en todo México y proyectar sus costos para el período 2021-2030. Métodos. Los datos de incidencia se obtuvieron del Secretariado Ejecutivo del Sistema Nacional de Seguridad Pública (SESNSP), el Consejo Nacional de Población (CONAPO), el Instituto Nacional de Estadística y Geografía (INEGI), y la Encuesta Nacional de Victimización y Percepción sobre Seguridad Pública (ENVIPE). Nuestro modelo incorpora estimaciones de la incidencia de los costos de los eventos asociados a la violencia (por ejemplo, homicidios, hospitalizaciones, violaciones, extorsiones, robos, etc.) Resultados. Se ha estimado que el impacto económico del delito y la violencia en México para el año 2021 es de alrededor de US$ 192 000 millones de dólares estadounidenses, lo que corresponde al 14,6% del PIB nacional. Estimamos que una reducción del 50% de la violencia para el 2030 supondría un ahorro de al menos US$110 000 millones. Esto representa un ahorro de US$1 376 372 para cada empresa y de más de US$66 771 para cada mexicano. Conclusión. La violencia y los homicidios se han convertido en una de las preocupaciones económicas y de salud pública más apremiantes por su efecto sobre la salud, el desarrollo y el crecimiento económico. Debido a su bajo costo y alto impacto, la prevención es la forma más eficiente de responder al delito y la violencia, al tiempo que es un componente esencial de las estrategias sostenibles dirigidas a mejorar la seguridad ciudadana.

RESUMO Objetivo. Estimar o impacto econômico da violência no México em 2021 e fazer a projeção de custos para o período 2021-2030. Métodos. Os dados de incidência da violência no país foram obtidos da Secretaria Executiva do Sistema Nacional de Segurança Pública (SESNSP), do Conselho Nacional de População (CONAPO), do Instituto Nacional de Estatística e Geografia (INEGI) e da Pesquisa Nacional de Vitimização e Percepção de Segurança Pública (ENVIPE). O modelo incorpora estimativas de incidência de custos de eventos associados à violência (como homicídios, internações hospitalares, estupros, extorsões e roubos). Resultados. O impacto econômico da criminalidade e da violência no México foi estimado em torno de US$192 bilhões em 2021, o que equivale a 14,6% do produto interno bruto (PIB) nacional. Estima-se que reduzir a violência em 50% até 2030 pode resultar em uma economia de US$ 110 bilhões ou mais, o que representa uma redução de gastos de US$1 376 372 para cada empresa e de mais de US$66 771 para cada cidadão do México. Conclusão. A violência e os homicídios são um dos problemas econômicos e de saúde pública mais prementes por suas consequências à saúde, ao desenvolvimento e ao crescimento econômico do país. Devido ao seu baixo custo e alto impacto, a prevenção é a forma mais eficiente de combater a criminalidade e a violência, além de ser um componente essencial de qualquer estratégia sustentável para aumentar a segurança da população.

Ungual Spitz Nevus: Description of Dermoscopic Data.

Introduction: Spitz nevus is an uncommon, benign melanocytic proliferation that primarily appears on face, trunk or lower extremities of children. This lesion may share clinical and microscopical characteristics with melanoma, making it a diagnostic and management challenge. Case Report: A 13-year old male presented with an asymptomatic chronic dermatosis located on the third left-hand nail. Cutaneous examination revealed a homogeneous dark brown melanonychia which extended up to the cuticle. Upon dermoscopy, longitudinal bands measuring less than 3 mm wide of heterogeneous colors ranging from light to dark brown, and positive Hutchinson's sign were observed. Discussion/Conclusion: We report the second case of a Spitz nevus ungually localized which strongly resembled an ungual melanoma with a positive Hutchinson's sign upon dermoscopy. Describing the infrequent presentation and location of the Spitz nevus poses an opportunity to establish diagnostic and management criteria in the near future.

[Remnant gallbladder cholecystitis, an increasingly common entity: Case report]. / Colecistitis del remanente vesicular, una entidad en incremento: reporte de caso.

Background: Subtotal cholecystectomy was described in 1985 as an alternative to total cholecystectomy in cases of difficult cholecystectomy. It was classified as reconstituted and fenestrated subtotal. In spite of being a viable alternative, up to 10.6% of biliary leakage is reported and 2.2% of patients present with cholecystitis of the gallbladder remnant. The objective of this report is to describe and emphasize the importance of an adequate diagnosis of complications in patients with a history of subtotal cholecystectomy. Clinical case: 72-year-old male with a history of open subtotal cholecystectomy 6 years prior to his admission to the emergency department due to right hypochondrium pain and vomiting. He had a history of biliary pancreatitis and choledocholithiasis after subtotal cholecystectomy resolved by endoscopic retrograde cholangiopancreatography (ERCP). It was decided to admit the patient and a diagnosis of cholecystitis of the gallbladder remnant was made. Laparoscopic cholecystectomy of the remnant was performed with subsequent clinical resolution. Conclusions: Although subtotal cholecystectomy may be the only option in cases of difficult cholecystectomy, it may result in future complications. The possibility of more complex surgical reinterventions should be considered. Our case report demonstrates that total cholecystectomy in cases of cholecystitis should be performed whenever possible to avoid potential complications caused by subtotal cholecystectomy.

Introducción: la colecistectomía subtotal fue descrita en 1985 como una alternativa a la colecistectomía total en casos de colecistectomía difícil. Fue clasificada como subtotal reconstituida y fenestrada. A pesar de ser una alternativa viable, se reporta hasta un 10.6% de fuga biliar y 2.2% de los pacientes presentan colecistitis del remanente vesicular. El objetivo de este reporte de caso es incluir la colecistitis del remanente vesicular como diagnóstico diferencial en pacientes con antecedente de colecistectomía subtotal y dolor abdominal. Caso clínico: hombre de 72 años con antecedente de colecistectomía subtotal abierta. Seis años antes de su ingreso, acudió a un servicio de urgencias por dolor en hipocondrio derecho y vómito. Contaba con antecedente de pancreatitis biliar y coledocolitiasis posterior a colecistectomía subtotal resueltas por colangiopancreatografía retrógrada endoscópica (CPRE). Se decidió ingresar al paciente y se integró diagnóstico de colecistitis del remanente de la vesícula biliar. Se realizó colecistectomía laparoscópica del remanente con posterior resolución clínica. Conclusiones: a pesar de que la colecistectomía subtotal puede ser la única opción en casos de colecistectomía difícil, esta puede resultar en complicaciones futuras. La posibilidad de reintervenciones quirúrgicas más complejas debe ser considerada. Con nuestro reporte de caso podemos inferir que la colecistectomía total en casos de colecistitis debe realizarse siempre que sea posible para evitar potenciales complicaciones causadas por la colecistectomía subtotal.

Hospital volume is associated with cost and outcomes variation in 2,942 pelvic reconstructions.

BACKGROUND: Complex pelvic reconstruction is challenging for plastic and reconstructive surgeons following surgical resection of the lower gastrointestinal or genitourinary tract. Complication rates and hospital costs are variable and may be linked to the hospital case volume of pelvic reconstructions performed. A comprehensive examination of these factors has yet to be performed. METHODS: Data were retrieved for patients undergoing pedicled flap reconstruction after pelvic resections in the American National Inpatient Sample database between 2010 and 2014. Patients were then separated into three groups based on hospital case volume for pelvic reconstruction. Multivariate logistic regression and gamma regression with log-link function were used to analyze associations between hospital case volume, surgical outcomes, and cost. RESULTS: In total, 2,942 patients underwent pelvic flap reconstruction with surgical complications occurring in 1,466 patients (49.8%). Total median cost was $38,469.40. Pelvic reconstructions performed at high-volume hospitals were significantly associated with fewer surgical complications (low: 51.4%, medium: 52.8%, high: 34.8%; p < 0.001) and increased costs (low: $35,645.14, medium: $38,714.92, high: $44,967.29; p < 0.001). After regression adjustment, high hospital volume was the strongest independently associated factor for decreased surgical complications (Exp[ß], 0.454; 95% Confidence Interval, 0.346-0.596; p < 0.001) and increased hospital cost (Exp[ß], 1.351; 95% Confidence Interval, 1.285-1.421; p < 0.001). CONCLUSIONS: Patients undergoing pelvic flap reconstruction after oncologic resections experience high complication rates. High case volume hospitals were independently associated with significantly fewer surgical complications but increased hospital costs. Reconstructive surgeons may approach these challenging patients with greater awareness of these associations to improve outcomes and address cost drivers.

Evaluation of online Spanish and English health materials for preventive mastectomy. are we providing adequate information?

PURPOSE: Breast cancer remains the leading cause of cancer-related death in US Hispanic women. When present, lower health literacy levels potentially within this patient population require tailored materials to address health disparities. We aim to evaluate and compare Spanish and English online health care informative resources on preventive mastectomy. METHODS: A Google web search using "preventive mastectomy" and "mastectomía preventiva" was conducted. The first ten institutional/organizational websites in each language were selected. Assessment of mean reading grade level, cultural sensitivity, understandability, and actionability was carried out utilizing validated tools. RESULTS: The mean reading grade level for English materials was 14.69 compared with 11.3 for Spanish, both exceeding the recommended grade level established by the AMA and NIH. The mean cultural sensitivity score for English information was 2.20 compared with 1.88 for Spanish information, both below the acceptability benchmark of 2.5. English webpages scored 65% and 35% for understandability and actionability, respectively, while Spanish webpages scored 47% and 18%. CONCLUSIONS: Online English and Spanish preventive mastectomy materials were written at an elevated reading level and lacked cultural sensitivity. Spanish language information demonstrated inferior understandability, actionability, and cultural sensitivity. Addressing these issues provides an opportunity to help resolve health literature disparities regarding preventive mastectomy for US Hispanic women.

Electric field induced structural colour tuning of a silver/titanium dioxide nanoparticle one-dimensional photonic crystal.

An electric field is employed for the active tuning of the structural colour in photonic crystals, which acts as an effective external stimulus with an impact on light transmission manipulation. In this work, we demonstrate structural colour in a photonic crystal device comprised of alternating layers of silver nanoparticles and titanium dioxide nanoparticles, exhibiting spectral shifts of around 10 nm for an applied voltage of only 10 V. The accumulation of charge at the metal/dielectric interface with an applied electric field leads to an effective increase of the charges contributing to the plasma frequency in silver. This initiates a blue shift of the silver plasmon band with a simultaneous blue shift of the photonic band gap as a result of the change in the silver dielectric function (i.e. decrease of the effective refractive index). These results are the first demonstration of active colour tuning in silver/titanium dioxide nanoparticle-based photonic crystals and open the route to metal/dielectric-based photonic crystals as electro-optic switches.

Ultrafast Hole Transfer from (6,5) SWCNT to P3HT:PCBM Blend by Resonant Excitation.

Nowadays, SWCNTs are envisaged to enhance the charge separation or transport of conjugated polymer-fullerene derivatives blends. In this work we studied, by means of ultrafast transient absorption spectroscopy, three components blends in which commercially available SWCNTs are added to the standard bulk heterojunction. We explored three different configurations that give rise to diverse interfacing scenarios. We found strong evidence of a direct hole transfer from photoexcited SWCNTs to the P3HT polymer. The transfer efficiency depends on the interface configuration. It is the highest for the blend where we achieve closer contact between the (6,5) SWCNTs and the polymer. When the polymer blend is deposited on top of the nanotube film or the nanotube film is deposited onto the polymer blend, the process is slowed down due to less or missing interfacing of the carbon nanotubes with the polymer chains. Additionally we demonstrate a cascading effect in the electron path, which stabilizes charge separation by further transferring the electron left behind by hole transfer to the polymer to the adjacent (7,5) SWCNTs. Our results highlight the potential of semiconducting SWCNTs to improving the performance of organic solar cells.

Broadband pump-probe spectroscopy at 20-MHz modulation frequency.

We introduce an innovative high-sensitivity broadband pump-probe spectroscopy system, based on Fourier-transform detection, operating at 20-MHz modulation frequency. A common-mode interferometer employing birefringent wedges creates two phase-locked delayed replicas of the broadband probe pulse, interfering at a single photodetector. A single-channel lock-in amplifier demodulates the interferogram, whose Fourier transform provides the differential transmission spectrum. Our approach combines broad spectral coverage with high sensitivity, due to high-frequency modulation and detection. We demonstrate its performances by measuring two-dimensional differential transmission maps of a carbon nanotubes sample, simultaneously acquiring the signal over the entire 950-1350 nm range with 2.7·10-6 rms noise over 1.5 s integration time.

Análisis de riesgos para el trabajo con un analizador de diagnóstico de cámaras gamma / Risk analysis for working with an analyzer for gamma cameras diagnostic

Se realizó un estudio de los riesgos asociados al trabajo con un analizador para el diagnóstico de cámaras gamma. Para ello se utilizó el método Hazard Rating Number, el cual se basa en la determinación del número de riesgo. Los resultados mostraron que los riesgos con mayor HRN son por electrocución con un valor de 100 y por tocar el contenedor de la fuente con las manos, con 75. Estos riesgos se clasificaron como “Muy Alto” y “Alto” respectivamente. Como “Importante” se clasificaron los siguientes riesgos: caída del contenedor de la fuente (HRN = 25), dosis elevada de la muestra en el contenedor (HRN = 20) y fractura del cristal del detector (HRN = 30). El mal blindaje del contenedor de la fuente (HRN = 10) es un riesgo que se clasificó como “Bajo”. Se indican reglas de seguridad para uso del sistema. También se presenta un plan de acción para la gestión de los riesgos.

In this work, a risk analysis for working with an analyzer for gamma cameras diagnostic was made. The method employed is based on determining the Hazard Rating Number (HRN). The results showed that the risks with higher value of HRN are electrocution with 100 and touch source container with hands with 75. These risks were classified as "Very High" and "High" respectively. The following risks were classified as "Important": Fall of the source container (HRN = 25), high dose of the sample in the container (HRN = 20) and fracture of glass detector (HRN = 30). The wrong shielding of the source container (HRN= 10) is a risk that was classified as "Low". Safety rules for use of the system are indicated. An action plan for risk management is also presented.

La gestión del riesgo como eje transversal de los proyectos curriculares

El documento hace énfasis en la inclusión de la gestión del riesgo en los programas curriculares, en la cultura y la conceptualización del tema de riesgo por parte de los docentes.