Label-free detection and profiling of individual solution-phase molecules.

Most chemistry and biology occurs in solution, in which conformational dynamics and complexation underlie behaviour and function. Single-molecule techniques1 are uniquely suited to resolving molecular diversity and new label-free approaches are reshaping the power of single-molecule measurements. A label-free single-molecule method2-16 capable of revealing details of molecular conformation in solution17,18 would allow a new microscopic perspective of unprecedented detail. Here we use the enhanced light-molecule interactions in high-finesse fibre-based Fabry-Pérot microcavities19-21 to detect individual biomolecules as small as 1.2 kDa, a ten-amino-acid peptide, with signal-to-noise ratios (SNRs) >100, even as the molecules are unlabelled and freely diffusing in solution. Our method delivers 2D intensity and temporal profiles, enabling the distinction of subpopulations in mixed samples. Notably, we observe a linear relationship between passage time and molecular radius, unlocking the potential to gather crucial information about diffusion and solution-phase conformation. Furthermore, mixtures of biomolecule isomers of the same molecular weight and composition but different conformation can also be resolved. Detection is based on the creation of a new molecular velocity filter window and a dynamic thermal priming mechanism that make use of the interplay between optical and thermal dynamics22,23 and Pound-Drever-Hall (PDH) cavity locking24 to reveal molecular motion even while suppressing environmental noise. New in vitro ways of revealing molecular conformation, diversity and dynamics can find broad potential for applications in the life and chemical sciences.

Predictive models for health outcomes due to SARS-CoV-2, including the effect of vaccination: a systematic review.

BACKGROUND: The interaction between modelers and policymakers is becoming more common due to the increase in computing speed seen in recent decades. The recent pandemic caused by the SARS-CoV-2 virus was no exception. Thus, this study aims to identify and assess epidemiological mathematical models of SARS-CoV-2 applied to real-world data, including immunization for coronavirus 2019 (COVID-19). METHODOLOGY: PubMed, JSTOR, medRxiv, LILACS, EconLit, and other databases were searched for studies employing epidemiological mathematical models of SARS-CoV-2 applied to real-world data. We summarized the information qualitatively, and each article included was assessed for bias risk using the Joanna Briggs Institute (JBI) and PROBAST checklist tool. The PROSPERO registration number is CRD42022344542. FINDINGS: In total, 5646 articles were retrieved, of which 411 were included. Most of the information was published in 2021. The countries with the highest number of studies were the United States, Canada, China, and the United Kingdom; no studies were found in low-income countries. The SEIR model (susceptible, exposed, infectious, and recovered) was the most frequently used approach, followed by agent-based modeling. Moreover, the most commonly used software were R, Matlab, and Python, with the most recurring health outcomes being death and recovery. According to the JBI assessment, 61.4% of articles were considered to have a low risk of bias. INTERPRETATION: The utilization of mathematical models increased following the onset of the SARS-CoV-2 pandemic. Stakeholders have begun to incorporate these analytical tools more extensively into public policy, enabling the construction of various scenarios for public health. This contribution adds value to informed decision-making. Therefore, understanding their advancements, strengths, and limitations is essential.

Pachymeningeal disease: a systematic review and metanalysis.

BACKGROUND: Pachymeningeal disease (PMD) is a newly recognized pattern of brain metastasis (BrM) failure that specifically occurs following surgery with adjuvant stereotactic radiosurgery (SRS) and has unique prognostic implications relative to leptomeningeal disease (LMD). Here, we report its prevalence, prognostic implications, and associated risk factors. METHODS: A literature search was performed in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses on PUBMED and Cochrane from January 2000 to June 2023. RESULTS: We identified 12 studies that included a total of 3992 BrM patients, 659 (16.5%) of whom developed meningeal disease (MD) following surgery plus adjuvant SRS, including either PMD or LMD. The mean prevalence of MD across studies was 20.9% (7.9-38.0%), with PMD accounting for 54.6% of this prevalence and LMD comprising the remaining 45.4%. Mean of the median overall survivals following diagnosis of PMD and LMD was 10.6 months and 3.7 months p = 0.007, respectively, a significant difference. Only 2 risk factors for PMD were reported in ≥ 2 studies and also identified as statistically significant per our meta-analysis: infratentorial location and controlled systemic disease status. CONCLUSION: While PMD has a superior prognosis to LMD, it is nevertheless a critical oncologic event associated with significant mortality and remains poorly recognized. PMD is predominantly observed in patients with controlled systemic disease status and infratentorial location. Future treatment strategies should focus on reducing surgical seeding and sterilizing surgical cavities.

Electromagnetic deactivation spectroscopy of human coronavirus 229E.

An investigation of the deactivation of pathogens using electromagnetic waves in the microwave region of the spectrum is achieved using custom-built waveguide structures. The waveguides feature sub-wavelength gratings to allow the integration of an air cooling system without disturbing the internal propagating fields. The waveguides are tapered to accommodate an experimental sample internally with sufficient surrounding airflow. The proposed methodology allows for precise control over power densities due to the well-defined fundamental mode excited in each waveguide, in addition to temperature control of the sample due to microwave exposure over time. Human coronavirus (HCoV-229E) is investigated over the 0-40 GHz range, where a peak 3-log viral reduction is observed in the 15.0-19.5 GHz sub-band. We conclude HCoV-229E has an intrinsic resonance in this range, where nonthermal structure damage is optimal through the structure-resonant energy transfer effect.

Label-free observation of individual solution phase molecules.

The vast majority of chemistry and biology occurs in solution, and new label-free analytical techniques that can help resolve solution-phase complexity at the single-molecule level can provide new microscopic perspectives of unprecedented detail. Here, we use the increased light-molecule interactions in high-finesse fiber Fabry-Pérot microcavities to detect individual biomolecules as small as 1.2 kDa with signal-to-noise ratios >100, even as the molecules are freely diffusing in solution. Our method delivers 2D intensity and temporal profiles, enabling the distinction of sub-populations in mixed samples. Strikingly, we observe a linear relationship between passage time and molecular radius, unlocking the potential to gather crucial information about diffusion and solution-phase conformation. Furthermore, mixtures of biomolecule isomers of the same molecular weight can also be resolved. Detection is based on a novel molecular velocity filtering and dynamic thermal priming mechanism leveraging both photo-thermal bistability and Pound-Drever-Hall cavity locking. This technology holds broad potential for applications in life and chemical sciences and represents a major advancement in label-free in vitro single-molecule techniques.

Translation, adaptation, and validation of the MeNTS score in colombian population: The MeNTS Col score.

Objective: To evaluate and validate the medically necessary and time sensitive score by testing the variables, in order to create a surgical preoperative score for procedure prioritization in COVID-19 pandemic in Colombia. Methods: A multicenter retrospective cross-sectional study of instrument validation with a cultural adaptation and translation into the Spanish language was carried out in Bogota, Colombia. Patients over 18 years of age who had undergone elective procedures of general surgery and subspecialties were included. The translation of the medically necessary and time sensitive score into Spanish was performed independently by two bilingual surgeons fluent in both English and Spanish. A final version of the Spanish questionnaire (MeNTS Col) for testing was then produced by an expert committee. After translation and cultural adaptation, it was submitted to evaluate the psychometric properties of the medically necessary and time sensitive score. Cronbach's α was used to represent and evaluate the internal consistency and assess reliability. Results: A total of 172 patients were included, with a median age of 54 years; of which 96 (55.8%) patients were females. The vast majority of patients were treated for general surgery (n = 60) and colon and rectal surgery (n = 31). The evaluation of the internal consistency of the scale items in Spanish version was measured, and values of 0.5 for 0.8 were obtained. In the reliability and validation process, Cronbach's α values in all items remained higher than 0.7. The new MeNTS Col model was analyzed, and a result of 0.91 was obtained. Conclusions: The Spanish version of the medically necessary and time sensitive, the MeNTS Col score, and its respective Spanish translation perform similarly to the original version. Therefore, they can be useful and reproducible in Latin American countries.

A culture-free biphasic approach for sensitive and rapid detection of pathogens in dried whole-blood matrix.

Blood stream infections (BSIs) cause high mortality, and their rapid detection remains a significant diagnostic challenge. Timely and informed administration of antibiotics can significantly improve patient outcomes. However, blood culture, which takes up to 5 d for a negative result, followed by PCR remains the gold standard in diagnosing BSI. Here, we introduce a new approach to blood-based diagnostics where large blood volumes can be rapidly dried, resulting in inactivation of the inhibitory components in blood. Further thermal treatments then generate a physical microscale and nanoscale fluidic network inside the dried matrix to allow access to target nucleic acid. The amplification enzymes and primers initiate the reaction within the dried blood matrix through these networks, precluding any need for conventional nucleic acid purification. High heme background is confined to the solid phase, while amplicons are enriched in the clear supernatant (liquid phase), giving fluorescence change comparable to purified DNA reactions. We demonstrate single-molecule sensitivity using a loop-mediated isothermal amplification reaction in our platform and detect a broad spectrum of pathogens, including gram-positive methicillin-resistant and methicillin-susceptible Staphylococcus aureus bacteria, gram-negative Escherichia coli bacteria, and Candida albicans (fungus) from whole blood with a limit of detection (LOD) of 1.2 colony-forming units (CFU)/mL from 0.8 to 1 mL of starting blood volume. We validated our assay using 63 clinical samples (100% sensitivity and specificity) and significantly reduced sample-to-result time from over 20 h to <2.5 h. The reduction in instrumentation complexity and costs compared to blood culture and alternate molecular diagnostic platforms can have broad applications in healthcare systems in developed world and resource-limited settings.

Guía de práctica clínica para el manejo de la neumonía adquirida en la comunidad / Clinical Practice Guideline for the management of community-acquired pneumonia

Resumen La neumonía sigue siendo una de las principales causas de consulta y de hospitalización a la que, además de su un alto impacto en términos de morbilidad y mortalidad, se suma la actual problemática de resistencia a los antimicrobianos, por lo que establecer directrices que permitan su adecuado diagnóstico y tratamiento es de gran importancia para obtener mejores desenlaces clínicos y promover un uso racional de antibióticos en estos pacientes. La presente guía de práctica clínica (GPC) contiene recomendaciones basadas en la evidencia para el diagnóstico y tratamiento de la neumonía adquirida en la comunidad en adultos, las cuales fueron realizadas mediante el proceso de adaptación de GPC basadas en la evidencia para el contexto colombiano.

Abstract Pneumonia continues to be one of the main causes of consultation and hospitalization to which, besides its high impact on morbidity and mortality, the current problem of antimicrobial resistance is added; thus, establishing guidelines that allow its adequate diagnosis and treatment is of great importance to obtain better clinical outcomes and promote a rational use of antibiotics in these patients. This clinical practice guideline (CPG) contains evidence-based recommendations for the diagnosis and treatment of community-acquired pneumonia in adult population; these recommendations were made by means of the process of adaptation of evidence-based CPGs for the Colombian context.

Microstrip sensor and methodology for the determination of complex anisotropic permittivity using perturbation techniques.

In this work, a sensor in microstrip technology and a methodology for measuring the real part and the imaginary part of the complex uniaxial permittivity of solid anisotropic samples are presented. The sensor is based on a pair of parallel lines coupled resonators and a cleft arranged in the coupling region which allows to hold the samples under test (SUTs). The proposed methodology relates the change in the even/odd resonance frequency with the real part of the permittivity in the vertical/horizontal direction, and the change in the Q factor of the even/odd mode with the imaginary part of the permittivity in the vertical/horizontal direction. The methodology was successfully verified with the characterization, at 2.43 GHz of anisotropic samples of printed PLA, Diclad 880, and RO4350B using the knowns materials: RT5870, PTFE and RO4003.

Culture-free biphasic approach for sensitive detection of Escherichia coli O157:H7 from beef samples.

Foodborne illnesses are a major threat to public health also leading to significant mortality and financial and reputational damage to industry. It is very important to detect pathogen presence in food products early, rapidly, and accurately to avoid potential outbreaks and economic loss. However, "gold standard" culture methods, including enrichment of pathogens, can take up to several days. Moreover, the food matrix often interferes with nucleic acid amplification methods of detection, requiring DNA extraction from the sample for successful molecular detection of pathogens. Here, we introduce a "biphasic" amplification method that can achieve high sensitivity detection with background noise from ground beef food samples without culture or other extraction methods in 2.5 h. Homogenized ground beef is dried resulting in an increase in porosity of the dried food matrix to allowing amplification enzymes and primers to access the target DNA and initiate the reaction within the dried food matrix. Using Loop Mediated Isothermal Amplification, we demonstrate the detection of 1-3 cfu of Escherichia coli bacteria in 30 mg of dried food matrix. Our approach significantly lowers the time to result to less than a few hours and have a pronounced impact on reduction of instrumentation complexity and costs.

Prevalencia de síndrome de burnout en postulantes al examen de residencia médica / Prevalence of Burnout syndrome among Medical Residency applicants

Introducción: Los médicos que se preparan para rendir el examen de residencia médica, están expuestos a estrés laboral, debido a que adicionalmente tienen que trabajar para poder solventar sus estudios. Objetivos: Determinar la prevalencia del síndrome de burnout en médicos generales que se preparan para el examen de residencia médica. Métodos: Se realizó un estudio descriptivo y transversal, se aplicó el cuestionario Maslach Burnout Inventory (MBI) a médicos generales que trabajaban y que se preparaban para rendir el examen de residencia médica, que voluntariamente aceptaron participar en el estudio. Se realizó estadística univariada y bivariada; los cálculos fueron realizados con un nivel de confianza del 95 por ciento. Resultados: Se incluyó a un total de 306 médicos. El 56,9 por ciento fueron de sexo femenino y el promedio de edad fue de 28,5 ± 4,3 años. El 2,3 por ciento (7) de los médicos presentaron síndrome de burnout; las subescalas de despersonalización (42,2 por ciento) y agotamiento emocional (32 por ciento) tuvieron mayores porcentajes de índices altos. Conclusiones: La prevalencia de síndrome de burnout fue baja en los médicos generales que se preparan para el examen de residencia médica. Las subescalas con mayores índices fueron despersonalización y agotamiento emocional(AU)

Introduction: Doctors who are preparing to take the medical residency exam are exposed to work stress, because they have to work to pay their studies. Objectives: To determine the prevalence of Burnout syndrome in general practitioners preparing for the residency exam. Methods: A descriptive and cross-sectional study was carried out, the Maslach Burnout Inventory (MBI) was applied in general practitioners who worked and were preparing to take the medical residency exam were included, who voluntarily agreed to participate in the study. Univariate and bivariate statistics were performed, the calculations were performed with a confidence level of 95 percent. Results: A total of 306 general practitioners were included. 56,9 percent were female and the average age was 28,5 ± 4,3 years. 2,3 percent (7) of the doctors had Burnout syndrome, the subscales of depersonalization (42,2 percent) and emotional exhaustion (32 percent) had higher percentages of high indexes. Conclusions: The prevalence of Burnout syndrome was low in general practitioners preparing for the medical residency examination. The subscales with the highest indices were depersonalization and emotional exhaustion(AU)

3D printed millimeter-wave beam-steering reflector using dielectric fluids.

A three-dimensional printed beam-steering reflector surface with dielectric fluids as the tuning agent is presented. The reflector is made using ECO-ABS with six rows of 19 parallel channels of square cross-sections. The permittivity of the ECO-ABS was measured at 2.55 with a loss tangent of 0.053. A conductor is placed at the back of the dielectric. The squared channels are filled with either distilled water or air. The effective permittivity within the reflector changes according to the material used to fill the channels. As an incident wave propagates through the printed dielectric, the configuration of air-water channels shapes the exiting phase front of the wave by locally controlling its phase delay. The resulting phase profile created by the air-water configuration leads to a steered beam. Numerical full-wave simulations show steerable angles ranging from -42∘ to 23° for a set of air-water configurations at 30 GHz. A prototype was fabricated and tested for the same configurations. Experiments confirm a wide range of angles starting at -40∘ up to 20°.

Tunable fiber Fabry-Perot cavities with high passive stability.

We present three high finesse tunable monolithic fiber Fabry-Perot cavities (FFPCs) with high passive mechanical stability. The fiber mirrors are fixed inside slotted glass ferrules, which guarantee an inherent alignment of the resonators. An attached piezoelectric element enables fast tuning of the FFPC resonance frequency over the entire free-spectral range for two of the designs. Stable locking of the cavity resonance is achieved for sub-Hertz feedback bandwidths, demonstrating the high passive stability. At the other limit, locking bandwidths up to tens of kilohertz, close to the first mechanical resonance, can be obtained. The root-mean-square frequency fluctuations are suppressed down to ∼2% of the cavity linewidth. Over a wide frequency range, the frequency noise is dominated by the thermal noise limit of the system's mechanical resonances. The demonstrated small footprint devices can be used advantageously in a broad range of applications like cavity-based sensing techniques, optical filters or quantum light-matter interfaces.

Clinical practice guideline for screening of patients at risk of colonization by carbapenemase-producing Enterobacterales and the treatment of infections caused by these bacteria / Guía de práctica clínica para la tamización de pacientes con riesgo de colonización por Enterobacterales productores de carbapenemasasy el manejo de infecciones causadas por estas bacterias

Abstract Carbapenemase-producing Enterobacterales (CPE) infections have increased in recent years. Colombia has become an endemic country for this group of microorganisms, and the infections they cause have a serious impact in terms of morbidity and mortality. The early identification of CPE carriers who are admitted to health care centers as patients is necessary to implement adequate isolation and infection control measures to limit the spread of this type of microorganisms in hospitals. Furthermore, treating these infections is a challenging task due to the limited therapeutic alternatives available and the fact that there are only a few studies proving their effectiveness in this setting. Therefore, the objective of the present work is to develop a clinical practice guideline (CPG) for the screening of patients at risk of CPE colonization and the treatment of inpatients with suspected or confirmed infections caused by this type of bacteria through a CPG adaptation process based on the ADAPTE methodology. With this purpose in mind, evidence-informed recommendations for the screening and timely identification of CPE carriers admitted to hospitals are made, as well as for the adequate pharmacological treatment of CPE infections in this context.

Resumen Las infecciones por Enterobacterales productores de carbapenemasas (EPC) han aumentado en los últimos años. Colombia se ha convertido en un país endémico para este grupo de microorganismos y las infecciones que causan tienen un impacto importante en términos de morbimortalidad. La identificación temprana de los portadores de EPC que ingresan como pacientes a las instituciones de salud es necesaria para implementar medidas de aislamiento y control de infecciones adecuadas que limiten la diseminación de este tipo de microorganismos en los hospitales. Además, el tratamiento de estas infecciones es difícil debido a las limitadas alternativas terapéuticas disponibles y la escasez de estudios que demuestren su efectividad en este escenario. Por lo anterior, el objetivo del presente trabajo es desarrollar una guía de práctica clínica (GPC) para la tamización de pacientes con riesgo de colonización por EPC y para el manejo de pacientes con infecciones, ya sea sospechadas o confirmadas, causadas por este tipo de bacterias, mediante un proceso de adaptación de GPC basado en la metodología ADAPTE. Con este propósito en mente, se hacen recomendaciones informadas en evidencia para realizar la tamización y oportuna identificación de portadores de EPC admitidos en instituciones hospitalarias, así como para el adecuado manejo farmacológico de las infecciones por CPE en este escenario.

Detection of Leishmania RNA Virus in Clinical Samples from Cutaneous Leishmaniasis Patients Varies according to the Type of Sample.

Leishmania RNA virus (LRV) is a double-stranded RNA virus belonging to the Totiviridae family detected as cytoplasmic inclusions in some strains of the human parasite Leishmania spp. Experimental evidence supports the hypothesis that human coinfection with Leishmania spp.-LRV triggers an exacerbated immune response in the host that can be responsible for the observed complicated outcomes in cutaneous leishmaniasis (CL), such as mucosal leishmaniasis (ML) and treatment failure of CL. However, the reported frequencies of LRV associated with complicated outcomes in patient's series are highly variable, diminishing the relevance on the virus presence in the pathogenesis of the disease. To assess whether or not the inconsistent information about the frequency of LRV associated with CL complicated outcomes could be related to the virus detection approach, the present study evaluated the LRV presence in clinical samples using a diagnostic algorithm according to the type of the sample. In 36 samples with diagnosis of complicated forms of CL (15 of ML and 21 of CL antimony treatment failure) and six samples with non-Leishmania spp. infection, the LRV presence was assessed by RT-PCR, RT-qPCR, and nested RT-PCR. Viral load was estimated in parasite clinical isolates. By combining the methods, LRV1 presence was confirmed in 45% (9/20) of isolates and 37.5% (6/16) of the incisional biopsies. Remarkably, in some cases (4/8), LRV1 was undetectable in the isolates but present in their respective biopsies, and less frequently, the opposite was observed (1/8), suggesting the possibility of loss of parasites harboring LRV1 during the in vitro growth.

Extraction of a malpositioned maxillary anterior implant and simultaneous flapless ridge augmentation: a case report.

Periimplantitis in a malpositioned maxillary anterior implant is one of the most challenging situations in implant dentistry. Since the regenerative treatment can often be unpredictable and have esthetic consequences such as soft tissue recession due to flap raising, extraction is sometimes recommended. In order to place a new implant after extraction, a bone regeneration procedure must be carried out. This implies raising a flap and therefore the risk of further interproximal gingival recession. In the case presented in this article, a hopeless implant at position 11 presented severe periimplantitis and soft tissue recession, which also affected the mesial part of tooth 12. Tooth 21 had a root canal treatment and a crown. After the implant extraction, a minimally invasive simultaneous bone regeneration and soft tissue graft procedure was performed to reconstruct the remaining ridge using xenograft, a collagen membrane, and a connective tissue graft (CTG). Ten months later, in order to improve the ridge profile, an augmentation procedure was carried out using a CTG. Three months later, an implant was placed and immediately loaded. Three months after loading, the right lateral incisor that still presented a mesial gingival recession was slowly extruded by orthodontic treatment until the papilla was symmetrical to the contralateral one. At the end of the orthodontic extrusion, an implant-supported crown was placed at position 11 and a tooth-supported crown delivered in place of tooth 21. A composite restoration was performed on tooth 12. One year later, the soft tissue level was almost symmetrical at incisor level and the periimplant bone level at implant 11 was stable.

Colombian consensus on the diagnosis, treatment, and prevention of Candida Spp. disease in children and adults, / Consenso Colombiano Para el Diagnóstico, Tratamiento y Prevención de la Enfermedad por Candida Spp. en Niños y Adultos

Invasive Candidiasis (IC) and candidemia (as its most frequent manifestation) have become the main cause of opportunistic mycosis at hospital settings. This study, made by members of the Colombian Association of Infectious Diseases (ACIN), was aimed at providing a set of recommendations for the management, follow-up and prevention of IC / candidemia and mucous membrane candida infection in adult, pediatric and neonatal patients in a hospital setting, including the hemato-oncological and critical care units. All the data obtained through an exhaustive search were reviewed and analyzed in a comprehensive manner by all the members of the group, and the recommendations issued are being made after a careful review of the scientific literature available and the consensus of all specialists involved; the emergence of Candida Spp. problem is highlighted and a correct orientation to health professionals regarding the management of patients with candidiasis is provided in a rational and practical way, emphasizing patient evaluation, diagnostic strategies, prophylaxis, empirical treatment, directed treatment and preventative therapy.

La Candidiasis Invasora (CI) y la candidemia, como su manifestación más frecuente, se ha convertido en la principal causa de micosis oportunista a nivel hospitalario. Este manuscrito realizado por miembros de la Asociación Colombiana de Infectología (ACIN), tuvo como objetivo proporcionar un conjunto de recomendaciones para manejo, seguimiento y prevención de la CI/candidemia y de la infección candidiásica de mucosas, en población adulta, pediátrica y neonatal, en un entorno hospitalario, incluyendo las unidades hemato-oncológicas y unidades de cuidado crítico. Todos los datos obtenidos mediante una búsqueda exhaustiva, fueron revisados y analizados de manera amplia por todos los miembros del grupo, y las recomendaciones emitidas se elaboraron luego de la evaluación de la literatura científica disponible, y el consenso de todos los especialistas involucrados, reconociendo el problema de la emergencia de las infecciones por Candida Spp. y brindando una correcta orientación a los profesionales de la salud sobre el manejo de pacientes con enfermedad candidiásica, de una forma racional y práctica, enfatizando en la evaluación del paciente, estrategias de diagnóstico, profilaxis, tratamiento empírico, tratamiento dirigido y terapia preventiva.

Reconstrucción endovascular de aneurisma intracraneal mediante dispositivo diversor de flujo Pipeline®. Reporte de 2 casos y revisión de la literatura / Endovascular reconstruction of intracranial aneurysm using a Pipeline® flow diversifier device

Resumen Introducción: Los aneurismas intracraneales son anomalías vasculares cerebrales con una prevalencia aproximada a nivel mundial del 2-3%. Son la principal causa de hemorragia subaracnoidea no traumática, el diagnóstico y tratamiento preventivo de esta entidad puede reducir considerablemente la morbimortalidad que de ella deviene. Con la aparición de nuevos dispositivos de terapia endovascular cerebral como los diversores de flujo se ha logrado ofrecer al paciente un procedimiento menos invasivo que no requiere cirugía convencional, y una importante reducción en el número de días de estancia intrahospitalaria y de recuperación, con alto grado de seguridad. El tratamiento endovascular para aneurismas intracraneales ha evolucionado sustancialmente en las últimas dos décadas, convirtiéndose en el tratamiento de elección en diversas situaciones clínicas. Reporte de caso: Caso 1: Varón de 62 años edad que ingresa a unidad hospitalaria después de sufrir un traumatismo craneoencefálico moderado con pérdida transitoria del estado de alerta y cefalea holocraneana. Se realizó una tomografía de cráneo simple y con contraste ante la sospecha de hemorragia subaracnoidea. Se evidenció la presencia de un aneurisma intracraneal en la arteria carótida interna izquierda, segmento comunicante posterior de 4 x 3 mm con cuello de 3 mm. Se realizó tratamiento mediante la colocación de dispositivo diversor de flujo Pipeline®, así como control angiográfico a los 3 meses post-tratamiento con una evolución satisfactoria. Caso 2: Mujer de 59 años de edad que acudió por presentar hemiparesia facial y brazo ipsilateral, con incremento gradual de la intensidad y duración. Se inició protocolo de estudio con resonancia magnética. Se evidenció la presencia de aneurisma intracraneal de 15 mm de diámetro en el segmento comunicante de la arteria carótida interna derecha y otro de 8 mm contralateral. Fue programada para colocación de dispositivo diversor de flujo Pipeline® con adecuada evolución. Conclusión: El uso de dispositivos diversores de flujo es una excelente alternativa para el tratamiento de aneurismas intracraneales incidentales, con importantes ventajas de costo-efectividad, reduciendo tiempos quirúrgicos, de estancia hospitalaria y de recuperación. Además de tener un porcentaje de curación superior al 95% a 5 años.

Abstract Introduction: Intracranial aneurysms are cerebral vascular anomalies with an approximate global prevalence of 2 to 3% and are the main cause of non-traumatic subarachnoid hemorrhage. Diagnosis and preventive treatment of this entity can considerably reduce morbidity and mortality. With the advent of new devices for cerebral endovascular therapy such as flow diverters, the patient now has the option of choosing a less invasive procedure, which does not require conventional surgery. This represents a significant reduction in the number of days of in hospital stay and recovery. The procedure has showed a high degree of security. The endovascular treatment for intracranial aneurysms has evolved substantially in the last two decades, and has become the treatment of choice. Case report: Case 1: A 62-year-old male was admitted in the hospital after a moderate cranioencephalic trauma with transient loss of conscious and a holocranial headache. A cerebral angiography was performed to rule out subarachnoid hemorrhage. The angiography showed an intracranial aneurysm. It was localized in left internal carotid-posterior communicating artery. The measures were of 4mm X 3mm with a 3mm neck. The treatment was performed with a pipeline flow-diverting device, as well as an angiographic control 3 months after the treatment with a satisfactory evolution. Case 2: A 59-year-old female patient with facial hemiparesis and ipsilateral arm, that showed a gradual increase in intensity and duration. A magnetic resonance study protocol was initiated and an intracranial aneurysm was observed in the communicating segment of the right internal carotid artery. The diameter of the aneurysmal sac was of 15 mm and also, a contralateral of 8 mm. Placement of a flow-diverting device was programmed. Conclusion: The use of flow-diverting devices is an excellent alternative for the treatment of incidental intracranial aneurysms, with important cost-effectiveness advantages, surgical time, hospital stay and recovery reduction. In addition to having a recovery percentage of 95% in 5 years.

Conversion of "Customizable Units" into N-Alkyl Amino Acids and Generation of N-Alkyl Peptides.

An efficient conversion of hydroxyproline "customizable" units into new amino acids with a variety of N-alkyl substituents is described. The process is versatile and can afford valuable N-methyl amino acids and N, O-acetals. In addition, it allows the introduction of N-homoallylic substituents and N-chains with terminal ester, ketone, or cyano groups. These chains could be used for peptide extension or conjugation to other molecules (e.g., by olefin metathesis, peptide ligation, etc.). The transformation is carried out in just two (for R = CH2OAc) or three steps (scission of the pyrrolidine ring, manipulation of the α-chain, and the N-substituent) under mild, metal-free conditions, affording products with high optical purity.