Tunable Color of Aggregation-Induced Emission Enhancement in a Family of Hydrogen-Bonded Azines and Schiff Bases.

A simple synthesis strategy afforded a family of hydrogen-bonded azines and Schiff-bases. Although in dilute solution these dyes are faint light emitters, all exhibit bright luminescence upon aggregation. Changing the peripheral substituents from electron donating to electron withdrawing allows emission fine-tuning in a range from bluish-green to orange-red. The crystal structures of the materials reveal that the restriction of intramolecular rotations is the main mechanism for the aggregation-induced emission enhancement properties.

Natural glycoconjugates with antitumor activity.

Cancer is one of the major causes of death worldwide. As a consequence, many different therapeutic approaches, including the use of glycosides as anticancer agents, have been developed. Various glycosylated natural products exhibit high activity against a variety of microbes and human tumors. In this review we classify glycosides according to the nature of their aglycone (non-saccharidic) part. Among them, we describe anthracyclines, aureolic acids, enediyne antibiotics, macrolide and glycopeptides presenting different strengths and mechanisms of action against human cancers. In some cases, the glycosidic residue is crucial for their activity, such as in anthracycline, aureolic acid and enediyne antibiotics; in other cases, Nature has exploited glycosylation to improve solubility or pharmacokinetic properties, as in the glycopeptides. In this review we focus our attention on natural glycoconjugates with anticancer properties. The structure of several of the carbohydrate moieties found in these conjugates and their role are described. The structure­activity relationship of some of these compounds, together with the structural features of their interaction with the biological targets, are also reported. Taken together, all this information is useful for the design of new potential anti-tumor drugs.

Rheological Study of Phenol Formaldehyde Resole Resin Synthesized for Laminate Application.

Heat explosions are sometimes observed during the synthesis of phenol formaldehyde (PF) resin. This scenario can be attributed to the high latent heat that was released and not dissipated leading to the occurrence of a runaway reaction. The synthesis temperature and time played important roles in controlling the heat release, hence preventing the resin from hardening during the synthesis process. This study aims to assess the rheological and viscoelasticity behaviors of the PF resin prepared using paraformaldehyde. The prepared PF resin was designed for laminate applications. The rheological behavior of the PF resin was assessed based on the different molar ratios of phenol to paraformaldehyde (P:F) mixed in the formulation. The molar ratios were set at 1.00:1.25, 1.00:1.50 and 1.00:1.75 of P to F, respectively. The rheological study was focused at specific synthesis temperatures, namely 40, 60, 80 and 100 °C. The synthesis time was observed for 240 min; changes in physical structure and viscosity of the PF resins were noted. It was observed that the viscosity values of the PF resins prepared were directly proportional to the synthesis temperature and the formaldehyde content. The PF resin also exhibited shear thickening behavior for all samples synthesized at 60 °C and above. For all PF resin samples synthesized at 60 °C and above, their viscoelasticity results indicated that the storage modulus (G'), loss modulus(G″) and tan δ are proportionally dependent on both the synthesis temperature and the formaldehyde content. Heat explosions were observed during the synthesis of PF resin at the synthesis temperature of 100 °C. This scenario can lead to possible runaway reaction which can also compromise the safety of the operators.

When "the Cure" Is the Risk: Understanding How Substance Use Affects HIV and HCV in a Layered Risk Environment in San Juan, Puerto Rico.

BACKGROUND: Substance use, particularly injection drug use, continues to fuel the HIV/HCV (hepatitis C virus) epidemics in San Juan, Puerto Rico (PR). AIM: This article examines individual and sociostructural factors that affect HIV/HCV risk among people who use drugs (PWUD) living with or at risk for HIV/HCV in San Juan, PR. Findings were used to inform a community-level intervention to enhance HIV care access and retention for this population. METHOD: A rapid ethnographic assessment in collaboration with a community-based organization was conducted. Data collection took place between June and December 2013 and included field observations, 49 unstructured interviews with PWUD, and 19 key informant interviews with community stakeholders. Fieldnotes, photographs, and interview transcripts were analyzed for recurrent themes and to address the intervention-planning needs. Study results are presented as fieldnote excerpts, direct quotes from interviews, and photographs. RESULTS: Findings suggest that PWUD in PR face myriad challenges that affect HIV/HCV risk and hinder linkage to and retention in care. Results describe a layered risk environment where PWUD encounter many barriers to prevention, care, and treatment such as transience, social isolation, stigma, limited housing options, and inadequate medical and substance use disorder treatment services. DISCUSSION: These observed circumstances provide an empirical basis for the development and evaluation of comprehensive interventions that may serve to reduce barriers to care and link individuals to other supportive services. CONCLUSION: New approaches and comprehensive interventions are needed to break the structures that perpetuate risk and lack of engagement and retention in HIV care and substance use disorder treatment in San Juan.

Duplicación del apéndice vermiforme. Reporte de caso / Vermiform appendix duplication - case report

Dar a conocer una presentación inusual de una patología frecuente. Se presenta caso de paciente masculino de 27 años con cuadro clínico de apendicitis aguda. Se realiza apendicetomía abierta en la cual se identifican dos apéndices vermiformes. Se confirma el diagnóstico por medio de anatomía patología, una con apendicitis aguda perforada y otra con peri-apendicitis. Es importante el conocimiento de esta patología para que se pueda reconocer y evitar errores de juicio durante el procedimiento quirúrgico y futuras complicaciones para el paciente. (AU)

Report an unusual presentation of a common pathology. A case of a 27-year-old male with a clinical picture of acute appendicitis is presented. An open appendectomy is performed in which two vermiform appendages are identified. The diagnosis is confirmed by pathology, one with perforated acute appendicitis and the other with peri-appendicitis. Knowledge of this pathology is important so that errors of judgment can be recognized and avoided during the surgical procedure and future complications for the patient. (AU)

Decisions about the diagnostic and treatment criteria of dental caries among a group of dental students, faculty staff and dentists within the city of Medellin, Colombia / Decisiones sobre los criterios de diagnóstico y tratamiento de la caries dental entre un grupo de estudiantes de odontología, profesores y odontólogos de la ciudad de Medellín, Colombia

Objective: To analyze the criteria for diagnosis and treatment decision-making in relation to dental caries in different participants (teachers of dentistry, dental students at dental schools, and dentists practicing at public oral health services) in the city of Medellin (Colombia). Material and Methods: A cross-sectional study was applied in the period September 2015-december 2016 by means of an international validated questionnaire in 340 participants (dental teachers: 69, dental students: 193, dentists: 78). The survey addressed several topics related to detection and restorative threshold, preferences of preparation type, restorative materials used and opinions about diagnosis and treatment for dental caries. A descriptive analysis was carried out and Chi square tests were applied to observe statistically significant differences between the study variables.Results: 340 participants were surveyed among teachers who teach cariology, health care dentists, and undergraduate final-year students. Most participants were women (70%). The age mean was higher for DDSs (46 ± 9 years). On average, practicing dentists and dental teachers had a work experience of 21 ± 9 years. In case of treatment decisions, the majority of the surveyed would use immediate operative restorative treatment for advanced carious lesions (inner one-third of the dentin for approximal and grade 5 for occlusal). In addition, respondents reported different cavities diagnosis for clinical occlusal cases and some significant statistically differences were found for restorative treatment decisions and type of materials according to the type of participant. Conclusion: Criteria for diagnosis and treatment of dental caries differed among the student, dentist and dental teachers with variety in diagnosis and treatment concepts. However, a conservative tendency for restorative treatment decisions was observed. Strategies for incorporating non-restorative and minimal measures in professional practice should be considered in curricula of universities.

Objetivo: Analizar los criterios para la toma de decisiones diagnósticas y terapéuticas en relación a la caries dental en diferentes participantes (docentes, estudiantes de odontología de las facultades de odontología y odontólogos de los servicios públicos de salud bucal) de la ciudad de Medellín (Colombia). Material y Métodos: Se aplicó un estudio transversal en el período septiembre 2015 - diciembre 2016 mediante cuestionario internacional validado en 340 participantes (profesores de odontología: 69, estudiantes de odontología: 193, odontólogos: 78). La encuesta abordó varios temas relacionados con la detección y el umbral de restauración, las preferencias del tipo de preparación, los materiales de restauración utilizados y las opiniones sobre el diagnóstico y el tratamiento de la caries dental. Se realizó un análisis descriptivo y se aplicaron pruebas de Chi cuadrado para observar diferencias estadísticamente significativas entre las variables de estudio. Resultados: Se encuestó a 340 participantes entre profesores que imparten clases de cariología, odontólogos y estudiantes de último año de pregrado. La mayoría de los participantes eran mujeres (70%). La edad media fue mayor para los odontólogos (46 ± 9 años). En promedio, los odontólogos y los profesores de odontología tenían una experiencia laboral de 21 ± 9 años. En caso de decisiones de tratamiento, la mayoría de los encuestados utilizaría tratamiento restaurador quirúrgico inmediato para lesiones cariosas avanzadas (tercio interno de la dentina para proximal y grado 5 para oclusal). Además, los encuestados informaron diferentes diagnósticos de caries para los casos clínicos oclusales y se encontraron algunas diferencias estadísticamente significativas para las decisiones de tratamiento restaurativo y el tipo de materiales según el tipo de participante. Conclusion: Los criterios para el diagnóstico y tratamiento de la caries dental fueron diferentes entre los estudiantes, odontólogos y profesores de odontología con variedad en los conceptos de diagnóstico y tratamiento. Sin embargo, se observó una tendencia conservadora para las decisiones de tratamiento restaurativo. Las estrategias para incorporar medidas mínimas y no restaurativas en la práctica profesional deben ser consideradas en los planes de estudio de las universidades.

Demonstration of a left atrial input to the atrioventricular node in humans.

BACKGROUND: During right atrial stimulation, the anterior and posterior approaches provide inputs to the atrioventricular (AV) node. The purpose of the present study was to determine how activation proceeding from the left atrium reaches the AV node. METHODS AND RESULTS: We studied AV nodal conduction during right and left atrial (coronary sinus) stimulation in 46 patients (27 women and 19 men; mean age, 46+/-4 years) who had structurally normal hearts. At an identical cycle length (600 ms), left atrial stimulation resulted in shorter A-H intervals than right atrial stimulation (73+/-3 ms versus 99+/-3 ms; P<0.05). In addition, atrial electrograms recorded close to the His bundle changed from near to far field potentials when stimulation was shifted to the left atrium. The A-H interval prolonged as the site of pacing was progressively moved from the distal to the proximal coronary sinus. During constant pacing from the distal coronary sinus, atrial activation close to the His bundle could be advanced by late extrastimuli delivered at the anterior and posterior approaches (up to 11+/-2 ms and 9+/-1 ms, respectively), without altering His bundle activation time. In contrast, late extrastimuli delivered at the inferoparaseptal mitral annulus advanced both the A and H electrograms in 19 of 20 patients, which is consistent with a left-sided input to the AV node. Right and left atrial stimulation resulted in similar AV nodal function. CONCLUSION: The mitral annulus provides a left atrial input to the human AV node.

Effect of right atrial pacing, intravenous amiodarone and beta blockers for suppression of atrial fibrillation after coronary artery bypass surgery: a pilot study.

OBJECTIVE: This pilot study aimed to compare right atrial pacing, intravenous amiodarone and oral beta-blockers in the prevention, time to onset, duration and effect on hospital stay of postoperative atrial fibrillation (AF) after coronary artery bypass graft surgery (CABG) at our center. BACKGROUND: AF is the most common arrhythmic complication after CABG and is related to increased morbidity, length of hospital stay and costs. Trials with different drugs and other therapeutic modalities including beta-blockers, intravenous amiodarone and override suppression of automatic atrial foci by atrial pacing have shown partial success as preventive measures. However, a comparison between those three interventions has not been reported. METHODS: Thirty-six consecutive patients that underwent CABG at our institution were randomly assigned to atrial pacing (18 patients) and intravenous amiodarone (18 patients) after baseline clinical, electrocardiographic and hemodynamic assessment. All patients received concomitant oral metoprolol or atenolol right after extubation. Thirty-three patients who had CABG at our center in the previous two months and that only received beta-blockers during their perioperative period served as a control group. RESULTS: The majority of baseline clinical and hemodynamic characteristics were similar in all groups. Only one patient (5.6%) developed AF in the atrial pacing group versus five (27.8%) on amiodarone and six (18.2%) who only received beta-blockers. That finding, however, did not attain statistical significance (p > 0.05). After adjusting for potential confounders, the odds of occurrence of AF was 77% lower in atrial pacing patients (OR = 0.23; 95% CI: 0.02, 2.20; p = 0.09) and 2.36 times higher in those on amiodarone (95% CI: 0.55, 10.24; P = 0.053) when compared to patients which only received beta blockers. Since only one patient on right atrial pacing developed atrial fibrillation, the analysis of the median time to onset and median duration of atrial fibrillation was restricted to those assigned to amiodarone and those who only received beta-blockers showing no statistically significant differences (p > 0.05). Although no statistical significance was achieved, the median hospital stay was one-day shorter in the beta-blockers group. Most of the side effects were minor and resolved without sequelae. CONCLUSION: This pilot study showed a trend in favor of atrial pacing versus intravenous amiodarone or beta-blockers in the prevention of postoperative AF after CABG in our center. Randomization of a larger patient sample would be required in order to ascertain the true value of the observed trend.

Nanoliposomes presenting on surface a cis-glycofused benzopyran compound display binding affinity and aggregation inhibition ability towards Amyloid ß1-42 peptide.

Nanoliposomes decorated on their surface with ligands for Aß-peptides, the key morphological features of Alzheimer's disease (AD), have been synthesized and characterized for their ability to target Aß-peptide aggregates. A tricyclic benzopyrane-glycofused structure has been exploited as Aß-peptide ligand, which was linked to liposomes via a copper-free, chemoselective, biocompatible click chemistry reaction. The tricyclic-decorated liposomes presented a mean diameter in the nanomolar range (150-200 nm), a negative z-potential and a good stability, at least up to one month. Integrity studies performed in the presence of serum proteins indicated that these decorated nanoliposomes fulfill the requirements for in vivo applications. NMR experiments carried out with Aß1-42 oligomers using both surface functionalized and plain (control) liposomes, revealed that the binding ability of the nanoliposomes was mediated by the presence of the tricyclic ligand on their surface. Finally ThT assay carried out with tricyclic-decorated liposomes showed significant decrease in thioflavine T fluorescence after 24 h, suggesting a significant inhibition/delay of Aß1-42 aggregation.

cis-Glyco-fused benzopyran compounds as new amyloid-ß peptide ligands.

A small library of glyco-fused benzopyran compounds has been synthesised. Their interaction features with Aß peptides have been characterised by using STD-NMR and trNOESY experiments. The conformational analysis of the compounds has also been carried out through molecular mechanics (MM) and molecular dynamics (MD) simulations.

Calcium phosphate nucleation on surface-modified PTFE membranes.

Highly porous PTFE membranes are currently being used in facial reconstructive surgery. The present study aims at improving this biomaterial through creating a more bioactive surface by introducing ionic groups onto the surface. The unmodified PTFE membrane does not induce inorganic growth after immersion in simulated body fluid (SBF) for up to 4 weeks. Copolymeric grafting with acrylic acid (AAc) by means of gamma irradiation and subsequent in vitro testing in SBF reveals that this copolymer initially acts as an ion-exchange material and subsequently induces growth of a calcium phosphate phase (Ca/P=2.7) when large amounts (15%) of pAAc are introduced onto the membrane surface. This copolymer is not expected to function well from a biomaterials perspective since SEM showed the pores on the surface to be partly blocked. In contrast, the surface of monoacryloxyethyl phosphate (MAEP)-modified samples is altered at a molecular level only. Yet the modified materials are able to induce calcium phosphate nucleation when the external surface coverage is 44% or above. The initial inorganic growth on these membranes in SBF has a (Ca+Mg)/P ratio of 1.1 (presumably Brushite or Monetite). The secondary growth, possibly calcium-deficient apatite or tricalcium phosphate, has a (Ca+Mg)/P ratio of 1.5. This result is a promising indicator of a bioactive biomaterial.

V-A block during atrioventricular nodal reentrant tachycardia: reentry confined to the AV node.

Retrograde block during atrioventricular (AV) nodal reentrant tachycardia is considered a rare phenomenon that can potentially occur in the AV node or in the atrium. A patient with slow-fast AV nodal reentrant tachycardia and transient VA block localized in the AV node is presented. Pharmacological and stimulation maneuvers identified the site of block in the AV node and not in the atrium. Thus, AV nodal reentry can be confined to the AV node.

Síntomas somáticos durante el climaterio, asociados con estados depresivos / Somatic symptoms during menopause associated to depressive states

Antecedentes: El periodo del climaterio ha sido un tema de interés desde el siglo pasado, por ser una etapa que se caracteriza por una gran variedad de síntomas en los diferentes sistemas. Las explicaciones que se han dado hasta el momento abarcan desde lo fisiológico hasta lo afectivo. En la actualidad se conoce que el 75 por ciento de las mujeres presentan una diversidad de trastornos los cuales estan asociados a factores de tipo afectivo, presetándose por las circunstancias propias de la historia y situación de vida, involucrando también la visión de la sexualidad, todo lo anterior identifica a la menopausia con un detonador de los síntomas emocionales, como en la depresión en mujeres climatéicas. Objetivo: Realizar mediciones en todas aquellas características emocionales que la literatura ha consignado, para poder obtener un perfil de nuestra población de pacientes en la etapa climatérica. Material y método: Por tal motivo se realizó una investigación exploratoria, transversal, con 149 pacientes de la clínica de climeterio del INPer. Las variables: independienteclimaterio; dependientes-depresión-sintomatología; controladas-edad-escolaridad-estado-civil-socio-económico. Los instrumentos empleados fueron: EAMD, encuesta de síntomas, los resultados refieren a una población con un promedio de edad de 49 años, perteneciente a la etapa postmenopáusica el 53.7 por ciento, 98 por ciento pertenecen a una clase media y baja, con una educación promedio de 9.06, y respecto a su ocupación, el 66.4 por ciento se dedicaba al hogar y su estado civil fue preponderantemente de mujeres casadas 57.7 por ciento, el promedio de embarazos fue de 4.63 y de hijos vivos de 3.4. Resultados: De la encuesta de síntomas, se encontró que de los 10 síntomas más frecuentes contestados 6 muestran aspectos de tipo psicológico. Con un promedio 16.29 síntomas referido por paciente. El 70.79 por ciento presentan síntomas de tipo depresivo. Conclusión: Las quejas somáticas múltiples referidas como severas, están asociadas de manera importante con estados emocionales de fondo depresivo. La atención integral de la paciente en el climaterio de contemplar la incorporación en el equipo interdisciplinario, de personal del área de la salud mental