Low-temperature study of a new nevirapine pseudopolymorph

The title compound (systematic name: 11-cyclo­propyl-4-methyl-5,11-dihydro-6H-dipyrido[3,2-b:2′,3′-e][1,4]diazepin-6-one butanol 0.3-solvate), C15H14N4O·0.3C4H9OH, was crystallized in a new triclinic pseudopolymorphic form, a butanol solvate, and the crystal structure determined at 150 K. The mol­ecular conformation of this new form differs from that reported previously, although the main inter­molecular hydrogen-bond pattern remains the same. N—H⋯O hydrogen bonds [N⋯O = 2.957 (3) Å] form centrosymmetric dimers and the crystal packing of this new pseudopolymorph generates infinite channels along the b axis

Novel silver‐functionalized poly(ɛ‐caprolactone)/biphasic calcium phosphate scaffolds designed to counteract post‐surgical infections in orthopedic applications

In this study, we designed and developed novel poly(ε‐caprolactone) (PCL)‐based biomaterials, for use as bone scaffolds, through modification with both biphasic calcium phosphate (BCP), to impart bioactive/bioresorbable properties, and with silver nitrate, to provide antibacterial protection against Staphylococcus aureus, a microorganism involved in prosthetic joint infections (PJIs). Field emission scanning electron microscopy (FESEM) showed that the samples were characterized by square‐shaped macropores, and energy dispersive X‐ray spectroscopy analysis confirmed the presence of PCL and BCP phases, while inductively coupled plasma–mass spectrometry (ICP–MS) established the release of Ag+ in the medium (~0.15–0.8 wt% of initial Ag content). Adhesion assays revealed a significant (p < 0.0001) reduction in both adherent and planktonic staphylococci on the Ag‐functionalized biomaterials, and the presence of an inhibition halo confirmed Ag release from enriched samples. To assess the potential outcome in promoting bone integration, preliminary tests on sarcoma osteogenic‐2 (Saos‐2) cells indicated PCL and BCP/PCL biocompatibility, but a reduction in viability was observed for Ag‐added biomaterials. Due to their combined biodegrading and antimicrobial properties, the silver‐enriched BCP/PCL-based scaffolds showed good potential for engineering of bone tissue and for reducing PJIs as a microbial anti‐adhesive tool used in the delivery of targeted antimicrobial molecules, even if the amount of silver needs to be tuned to improve osteointegration

N-Phenyl­nicotinamide

In the title compound, C12H10N2O, the dihedral angle between the phenyl and pyridine rings is 64.81 (1)°. Inter­molecular N—H⋯O hydrogen bonds connect the mol­ecules into chains running along the b axis

Evaluation of the bactericidal activity of a hyaluronic acid-vehicled clarithromycin antibiotic mixture by confocal laser scanning microscopy

Confocal laser scanning microscopy (CLSM) was used to evaluate the antibacterial effect and depth of action of a novel clarithromycin-containing triple antibiotic mixture, which was proposed for root canal disinfection in dental pulp regeneration. A previous study reported that this mixture had no tooth discoloration effects in vitro. After infection with Enterococcus faecalis for 3 weeks, the dentinal tubules in the cylindrical root specimens were exposed to different antibiotic mixtures: ciprofloxacin, metronidazole and minocycline (3-MIX); ciprofloxacin, metronidazole and clarithromycin (3-MIXC) and ciprofloxacin and metronidazole (2-MIX). Each antibiotic formulation was mixed with macrogol (MG) or hyaluronic acid (HA) vehicles. CLSM and viability staining were used to quantitatively analyze the mean depth of the antibacterial effect and the proportions of dead and live bacteria inside the dentinal tubules. The 3-MIX and 3-MIXC demonstrated a similar depth of action. The mean proportion of dead bacteria was similar in the 3-MIX and 3-MIXC groups, and both were statistically higher than that of 2-MIX (p = 0.014). Each antibiotic mixture showed a higher bactericidal efficacy if conveyed with HA, compared to MG (3-MIX, p = 0.019; 3-MIXC, p = 0.013 and 2-MIX, p = 0.0125). The depth of action and the antibacterial efficacy of 3-MIXC seemed comparable with 3-MIX

Características epidemiológicas y moleculares de <i>Chlamydia psittaci</i> provenientes de 8 casos humanos de psitacosis y de 4 aves relacionadas en la Argentina

In Argentina, the epidemiological and molecular characteristics of Chlamydia psittaci infections are still not sufficiently known. A total of 846 respiratory and 10 ocular samples from patients with suspected human psittacosis were tested for C. psittaci from January 2010 to March 2015. Four samples of birds related to these patients were also studied. Forty-eight samples were positive for C. psittaci by a nested PCR. The molecular characterization of twelve C. psittaci PCR-positive samples received in the National Reference Laboratory INEI-ANLIS “Dr. Carlos G. Malbrán”, Buenos Aires, Argentina was performed. Eight positive samples from humans and four from birds were genotyped by ompA gene sequencing. C. psittaci genotype A was found in all human samples and in the related birds. This report contributes to our increasing knowledge of the epidemiological and molecular characteristics of C. psittaci to conduct effective surveillance of its zoonotic infections.En la Argentina, aún no se conocen suficientemente las características epidemiológicas y moleculares de las infecciones por Chlamydia psittaci. Entre enero del 2010 y marzo del 2015 se estudiaron 846 muestras respiratorias y 10 oculares de pacientes con sospecha de psitacosis para la búsqueda de C. psittaci. También se estudiaron 4 muestras de aves relacionadas con estos pacientes. De ese total, 48 muestras fueron positivas para C. psittaci mediante una reacción en cadena de la polimerasa (PCR) anidada. Posteriormente, se realizó en el INEI-ANLIS «Dr. Carlos G. Malbrán» la caracterización molecular de 12 muestras positivas para C. psittaci, 8 de humanos y 4 de aves, que fueron genotipificadas por secuenciación del gen ompA. C. psittaci genotipo A se encontró en todas esas muestras. Este informe contribuye a mejorar nuestro conocimiento de las características epidemiológicas y moleculares de C. psittaci para lograr una vigilancia efectiva de la zoonosis que produce.Facultad de Ciencias Veterinaria

Reflectividad infrarroja de SrRuO₃

En este trabajo presentamos los espectros de reflectividad infrarroja a temperatura ambiente y a 80K piara la perovskita distorsionada SrRuO₃. Con las relaciones de Krammers-Kronig calculamos las funciones ópticas y reconstruimos el espectro de reflectividad con un modelo basado en la generalización de la relación de Lyddane- Sachs-Teller y el modelo de Drude. Con estos datos calculamos el número de portadores, la movilidad efectiva y la conductividad óptica, comparando nuestros resultados con los conocidos para diferentes compuestos.Centro de Química Inorgánic