Photocatalytic ATRA reaction promoted by iodo-Bodipy and sodium ascorbate.

Using ascorbate as a sacrificial reductant, iodo-Bodipy dye 1b is able to promote the ATRA reaction between bromoderivatives and alkenes. This finding expands the possibility of using Bodipy dyes to promote photocatalytic reactions in efficient ways.

A machine learning tool for re-planning and adaptive RT: A multicenter cohort investigation.

PURPOSE: To predict patients who would benefit from adaptive radiotherapy (ART) and re-planning intervention based on machine learning from anatomical and dosimetric variations in a retrospective dataset. MATERIALS AND METHODS: 90 patients (pts) treated for head-neck cancer (H&N) formed a multicenter data-set. 41 H&N pts (45.6%) were considered for learning; 49 pts (54.4%) were used to test the tool. A homemade machine-learning classifier was developed to analyze volume and dose variations of parotid glands (PG). Using deformable image registration (DIR) and GPU, patients' conditions were analyzed automatically. Support Vector Machines (SVM) was used for time-series evaluation. "Inadequate" class identified patients that might benefit from replanning. Double-blind evaluation by two radiation oncologists (ROs) was carried out to validate day/week selected for re-planning by the classifier. RESULTS: The cohort was affected by PG mean reduction of 23.7±8.8%. During the first 3weeks, 86.7% cases show PG deformation aligned with predefined tolerance, thus not requiring re-planning. From 4th week, an increased number of pts would potentially benefit from re-planning: a mean of 58% of cases, with an inter-center variability of 8.3%, showed "inadequate" conditions. 11% of cases showed "bias" due to DIR and script failure; 6% showed "warning" output due to potential positioning issues. Comparing re-planning suggested by tool with recommended by ROs, the 4th week seems the most favorable time in 70% cases. CONCLUSIONS: SVM and decision-making tool was applied to overcome ART challenges. Pts would benefit from ART and ideal time for re-planning intervention was identified in this retrospective analysis.

A dendritic antenna for near-infrared emission of Nd3+ ions.

An interior of 18 amide groups and a periphery functionalized with 24 dansyl groups forms a light-harvesting dendrimer which features intense absorption bands in the near-UV spectral region and a strong fluorescence band in the visible region. Upon encapsulation of Nd(3+) ions, the fluorescence of the dansyl groups is quenched and an intense sensitized near-infrared emission of Nd(3+) is observed. The associated energy transfer is shown in the cartoon.

Eosin molecules hosted into a dendrimer which carries thirty-two dansyl units in the periphery: a photophysical study.

A fourth generation POPAM dendrimer functionalized at the periphery with 32 dansyl groups (circles in the picture) can host up to six eosin dye molecules (black ovals) in two different sites (triangle, square). Efficient energy transfer processes from the dansyl to eosin molecules occur. The picture shows some characteristic wavelengths and lifetimes of these transitions; excitation, emission, and energy transfer processes are represented by dotted, dashed, and full arrows, respectively.

[Multidimensional appraisal in patients suffering from chronic idiopathic constipation]. / Valutazione multidimensionale in pazienti affetti da stipsi cronica idiopatica.

A multidimensional appraisal of the patient suffering from chronic idiopatic constipation is used in this study. 16 consecutive patients affected by chronic idiopatic constipation defined by Rome criteria were enrolled. The following assessments were performed: radiological study of colorectal transit time using radiopaque markers, anorectal manometry, proctography, psychiatric appraisal, with the somministration of The Minnesota Multiphasic Personality Inventory 2, Hamilton Rating Scales for Depression, Hamilton Rating Scales for Anxiety, Toronto Alexithymia Scales, quality of life appraisal, by means of Short Form 36. The present study must be considered a pilot-study, lead on a limited champion of 16 cases; the reported data express therefore tendencies. Chronic idiopatic constipation appears to be a disturbance with a strong impact on the patient's quality of life. The study moreover confirms the hypothesis of a multifactorial genesis for chronic idiopatic constipation, in which psychopathological aspects (anxiety, depression and alessitimia in particular) and personality traits play a fundamental role, as much as the physiopathological alterations. Colorectal transit time study and anorectal manometry confirm to be valid instruments for the evaluation of physiopathological characteristics, useful for a classification of patients, particularly with respect to the presence of a normal or slowed colorectal transit and to the relief of pelvic floor dysfunctions. The differences between subgroups based on physiopathological characteristics, with respect to quality of the life and personality traits, expressed as tendency, need a confirm form studies lead on larger champions.

Synthesis and electronic properties of covalent assemblies of oligophenylenevinylene units arising from a calix.

Assemblies of four oligophenylenevinylene moieties arising from a calix[4]arene core, i.e., calix[4]oligophenylenevinylenes, have been prepared by Heck-type cross-coupling reactions of styrene derivatives with a tetraiodinated cone-calix[4]arene precursor. Photophysical studies in solution have revealed that there are electronic ground state interactions between the covalently bonded OPV moieties. The absorption spectra of the calix[4]oligophenylenevinylenes are significantly different from those obtained by summing the spectra of four model units and their emission is red-shifted when compared to the corresponding model compounds. Electrochemical studies have shown that the redox processes of the four OPV subunits do not take place at the same potentials indicating also a strong electronic interaction among them in the calix[4]oligophenylenevinylenes.

A photosensitizer dinuclear ruthenium complex: intramolecular energy transfer to a covalently linked fullerene acceptor.

A fullerene derivative (5) in which a dinuclear ruthenium complex is covalently linked to a fulleropyrrolidine (FP) through a rigid spacer has been prepared through azomethine ylide cycloaddition to C60. Electrochemical and photophysical studies revealed that ground-state electronic interactions between the bimetallic ruthenium chromophore and the FP moiety are small. The absorption spectrum of 5 displays a metal-to-ligand charge transfer (MLCT) transition at about 620 nm in CH2Cl2 which is shifted by nearly 160 nm relative to that of a previously reported mononuclear dyad (8). The photophysical investigations have also shown that both in dichloromethane and acetonitrile the photoexcited MLCT state of dyad 5 transforms into the fullerene triplet excited state with a quantum yield of 0.19 and that, contrary to mononuclear dyad 8, electron transfer, if any under the applied conditions, is negligible relative to energy transfer.

Tétanos en consulta de urgencia: ¿mito o realidad? / Tetanus in urgency services: myth or reality?

El tétanos, patología infecciosa causada por el bacilo Clostridum tetani, constituye actualmente en Chile una patología infrecuente gracias al programa nacional de vacunación en heridas de riesgo. Es por ello que su presentación en servicios de urgencia es raro. Por lo cual se consideró muy útil recordar la plena vigencia de esta antigua patología, así como sus severas consecuencias a través del análisis de dos casos clínicos en nuestro Hospital.