Characterizing Granuloma Annulare in 73 Pediatric Patients.

Background: Granuloma annulare (GA) is a common, benign, idiopathic inflammatory dermatosis. Aside from case reports and small studies, there are limited data about the characteristics of GA in children. Objective: This study aimed to better characterize the epidemiologic and clinical features, triggering factors, disease associations, and outcomes of GA in the pediatric population. Methods: We conducted a retrospective study of 73 pediatric patients diagnosed with GA at the University of Rochester Medical Center over a 7-year period. Results: The most common subtype was localized GA (71.2%, n = 52), followed by subcutaneous (also known as "deep GA"; 16.4%, n = 12) and generalized (12.3%, n = 9) subtypes. Over 90% of patients had idiopathic GA, with the remaining patients reporting viral infection or trauma as triggers. Half of the patients studied had comorbid conditions, most frequently atopic dermatitis (17.8%, n = 13), obesity (9.59%, n = 7), asthma (6.85%, n = 5), and allergic rhinitis (6.85%, n = 5). The median duration of the disease was 11.00 months (interquartile range (IQR) 15.75 months); generalized GA had the shortest duration (median 10.00 months, IQR 15.50 months), while subcutaneous GA had the longest duration (median 12.00 months and IQR 29.00 months). Although recurrence rates for subcutaneous and generalized GA were high at 45.5% and 33.3%, respectively, most patients achieved clearance or improvement with treatment. Conclusion: Most cases of GA in our study were idiopathic, with no clear differences between GA subtypes and associated comorbidities. Topical steroids were the most prescribed treatment with mixed efficacy.

New Organotin (IV) Compounds Derived from Dehydroacetic Acid and Thiosemicarbazides: Synthesis, Rational Design, Cytotoxic Evaluation, and Molecular Docking Simulation.

Organotin complexes were prepared through a one-pot reaction with three components by reacting thiosemicarbazide or 4-methyl-3-thiosemicarbazide or 4-phenylthiosemicarbazide, dehydroacetic acid (DHA) and dibutyl, diphenyl, dicyclohexyl, and bis[(trimethylsilyl)methyl]tin(IV) oxides; all complexes were characterized by infrared (IR), ultraviolet-visible (UV-vis), mass spectrometry (MS), and nuclear magnetic resonance (NMR) spectroscopy. The 119Sn NMR revealed chemical shifts corresponding to a pentacoordinated environment in solution. The X-ray crystallography of the two complexes evidenced the formation of monomeric complexes with a pentacoordinated geometry around tin via three donor atoms from the ligand, the sulfur of the thiol, the nitrogen of the imine group, and the oxygen of the pyran ring. The geometries of the five-coordinated complexes 3a (Bu2SnL3), 3c (Ph2SnL3), and 3d (Cy2SnL3) acid were intermediate between square pyramidal and trigonal bipyramidal, and complex 1a (Bu2SnL1) adopted a bipyramidal trigonal geometry (BPT). The sulforhodamine B assay assessed the cytotoxicity of organotin(IV) complexes against the MDA-MB-231 and MCF-7 (human mammary adenocarcinoma) cell lines and one normal COS-7 (African green monkey kidney fibroblast). The IC50 values evidenced a significant antiproliferative effect on cancer cells; the complexes were more potent than the positive cisplatin control and the corresponding ligands, dehydroacetic acid thiosemicarbazone (L1), dehydroacetic acid-N(4)-methylthiosemicarbazone (L2), and dehydroacetic acid-N(4)-phenylthiosemicarbazone (L3). The IC50 values also indicated that the organotin(IV) complexes were more cytotoxic against the triple-negative breast cell line MDA-MB-231 than MCF-7, inducing significant morphological alterations. The interactions of organotin(IV) 1c (Ph2SnL1), 1d (Cy2SnL1), and 1e (((CH3)3SiCH2)2SnL1) were evaluated with ss-DNA by fluorescence; intensity changes of the fluorescence were indicative of the displacement of ethidium bromide (EB), confirming the interaction of the organotin(IV) complexes with ss-DNA; the results showed a DNA binding affinity. The thermodynamic parameters obtained through isothermal titration calorimetry showed that the interaction of 1c (Ph2SnL1), with ss-ADN, was exothermic. Molecular docking studies also demonstrated that the organotin(IV) complexes were intercalated in DNA by conventional hydrogen bonds, carbon-hydrogen bonds, and π-alkyl interactions. These complexes furthermore showed a greater affinity towards DNA than cisplatin.

Nanocomposites of Silicon Oxides and Carbon: Its Study as Luminescent Nanomaterials.

In this work, hybrid structures formed by nanostructured layers, which contain materials, such as porous silicon (PSi), carbon nanotubes (CNTs), graphene oxide (GO), and silicon-rich oxide (SRO), were studied. The PSi layers were obtained by electrochemical etching over which CNTs and GO were deposited by spin coating. In addition, SRO layers, in which silicon nanocrystals are embedded, were obtained by hot filament chemical vapor deposition (HFCVD) technique. Photoluminescence (PL) spectra were obtained from the hybrid structures with which a comparative analysis was completed among different PL ones. The SRO layers were used to confine the CNTs and GO. The main purpose of making these hybrid structures is to modulate their PL response and obtain different emission energy regions in the PL response. It was found that the PL spectra of the CNTs/SRO and GO/SRO structures exhibit a shift towards high energies compared to those obtained from the PSi layers; likewise, the PSi/CNTs/SRO and PSi/GO/SRO structures show a similar behavior. To identify the different emission mechanisms originated by PSi, GO, CNTs, and SRO, the PL spectra were deconvolved. It was found that the Psi/CNTs/SRO and Psi/GO/SRO structures exhibit a PL shift in respect to the PSi layers, for this reason, the modulation of the PL emission of the structures makes these hybrid structures promising candidates to be applied in the field of photonic and electroluminescent devices.

Impacts of human activities on the supply of marine ecosystem services: A conceptual model for offshore wind farms to aid quantitative assessments.

Increased pressures from human activities may cause cumulative ecological effects on marine ecosystems. Increasingly, the study of ecosystem services is applied in the marine environment to assess the full effects of human activities on the ecosystem and on the benefits it provides. However, in the marine environment, such integrated studies have yet to move from qualitative and score-based to fully quantitative assessments. To bridge this gap, this study proposed a 4-tiered method for summarizing available knowledge and modelling tools to aid in quantitative assessments of ecosystem services supply. First, the ecosystem functioning mechanisms underlying the supply of services are conceptually mapped. Second, the impacts of the human activity of interest are summarized and linked to the first conceptual model in a case-specific model of ecosystem services supply. Third, indicators are selected that would best represent changes in the most important parameters of the conceptual model in a quantitative manner. Fourth, the knowledge gained in the previous steps is used to select models that are most useful to quantify changes in ecosystem services supply under the human pressure of interest. This approach was applied to the case study of offshore wind energy in the Belgian part of the North Sea, which is one of the most rapidly expanding industries in the marine environment globally. This study provides a useful tool to proceed towards quantification of marine ecosystem services, highlighting the need for a fully integrated approach to developing environmental impact assessment tools.

MIS-Like Structures with Silicon-Rich Oxide Films Obtained by HFCVD: Their Response as Photodetectors.

MIS-type structures composed of silicon-rich oxide (SRO), thin films deposited by hot filament chemical vapor deposition (HFCVD), show interesting I-V and I-t properties under white light illumination and a response as photodetectors. From electrical measurements, it was found that at a reverse bias of -4 V, the illumination current increased by up to three orders of magnitude relative to the dark current, which was about 82 nA, while the photogenerated current reached a value of 25 µA. The reported MIS structure with SRO as the dielectric layer exhibited a hopping conduction mechanism, and an ohmic conduction mechanism was found with low voltage. I-t measurements confirmed the increased photogenerated current. Furthermore, the MIS structure, characterized by current-wavelength (I-λ) measurements, exhibited a maximum responsivity value at 254 mA/W, specific detectivity (D*) at 2.21 × 1011 cm Hz1/2 W-1, and a noise equivalent power (NEP) of 49 pW at a wavelength of 535 nm. The structure exhibited good switching behavior, with rise and fall times between 120 and 150 ms, respectively. These rise and decay times explain the generation and recombination of charge carriers and the trapping and release of traps, respectively. These results make MIS-type structures useful as photodetectors in the 420 to 590 nm range.

Tiny Earth: A Big Idea for STEM Education and Antibiotic Discovery.

The world faces two seemingly unrelated challenges-a shortfall in the STEM workforce and increasing antibiotic resistance among bacterial pathogens. We address these two challenges with Tiny Earth, an undergraduate research course that excites students about science and creates a pipeline for antibiotic discovery.

Parameterizing a tumor humeral prosthesis and development of a set.

BACKGROUND: The reconstruction of the proximal humerus is possible from the resection of the tumor and the placement of a prosthesis. In some cases, they do not meet the anthropometric aspects of the patients. OBJECTIVE: To determine the parameters to size the components of a humeral prosthesis and the development of a set, using design software. METHOD: Forty patients were selected for prostheses, radiographs and CT scans were analyzed and statistical tests were applied to the measurements. RESULTS: The length of the tumors was 8-20 cm. The minimum length of the humerus was 28 cm and 33 cm the maximum. Correlation was observed between the humerus and the tumor and the height of the patient with p = 0.93088 and p = 0.904564, respectively; humerus diameter, p = 0.2345. The set will include three components, diameter 6-10 mm, and length of 24, 26 and 28 cm. Three modular spacers with lengths of 6, 8.5 and 13 cm. Crowns 6.5 and 8.5 cm long, 1.3 cm in diameter and 5 mm nut. CONCLUSION: With the development of the set, poorly calculated resections and adaptation to any humerus size can be resolved.

ANTECEDENTES: La reconstrucción del húmero proximal es posible a partir de la resección del tumor y la colocación de una prótesis. En algunos casos, las prótesis no cumplen con los aspectos antropométricos de los pacientes. OBJETIVO: Determinar los parámetros para dimensionar los componentes de una prótesis de húmero y el desarrollo de un set, mediante software de diseño. MÉTODO: Se seleccionaron 40 pacientes para prótesis, se analizaron radiografías y tomografías computarizadas, y se aplicaron pruebas estadísticas a las mediciones. RESULTADOS: La longitud de los tumores fue de 8-20 cm. La longitud mínima del húmero fue de 28 cm y la máxima fue de 33 cm. Se observó correlación entre el húmero y el tumor y la altura del paciente, con p = 0.93088 y p = 0.904564, respectivamente; para el diámetro del húmero, p = 0.2345. El set incluye tres componentes, con diámetro de 6-10 mm y longitud de 24, 26 y 28 cm; tres espaciadores modulares con longitudes de 6, 8,5 y 13 cm; coronas de 6,5 y 8,5 cm de largo, 1,3 cm de diámetro y tuerca de 5 mm. CONCLUSIÓN: Con el desarrollo del set se pueden resolver resecciones mal calculadas y la adaptación a cualquier tamaño de húmero.

Spectroscopic Properties of Si-nc in SiOx Films Using HFCVD.

In the present work, non-stoichiometric silicon oxide films (SiOx) deposited using a hot filament chemical vapor deposition technique at short time and simple parameters of depositions are reported. This is motivated by the numerous potential applications of SiOx films in areas such as optoelectronics. SiOx films were characterized with different spectroscopic techniques. The deposited films have interesting characteristics such as the presence of silicon nanoclusters without applying thermal annealing, in addition to a strong photoluminescence after applying thermal annealing in the vicinity of 1.5 eV, which may be attributed to the presence of small, oxidized silicon grains (less than 2 nm) or silicon nanocrystals (Si-nc). An interesting correlation was found between oxygen content, the presence of hydrogen, and the formation of defects in the material, with parameters such as the band gap and the Urbach energies. This correlation is interesting in the development of band gap engineering for this material for applications in photonic devices.

A pediatric case of pigmented epithelioid melanocytoma with chromosomal copy number alterations in 15q and 17q and a novel NTRK3-SCAPER gene fusion.

Pigmented epithelioid melanocytoma (PEM) represents a group of rare, heavily pigmented melanocytic tumors encompassing lesions previously designated as "animal-type melanomas" and "epithelioid blue nevi." Despite the association of multiple such tumors in the setting of Carney complex, most cases of PEM occur spontaneously as solitary neoplasms in otherwise healthy patients. PEM may arise in both children and adults, and has a known propensity to spread to the regional lymph nodes. Despite this latter finding, recurrence at the biopsy site or spread beyond the lymph node basin is exceptionally uncommon. Although the molecular basis for PEM continues to be characterized, findings to date suggest that this category of melanocytic neoplasia has genetic alterations distinct from those seen in common nevi, dysplastic nevi, Spitz nevi, and melanoma. Herein, we present an in-depth clinical, histopathologic, and molecular analysis of a case of PEM occurring on the scalp of a young African American girl found to have a novel NTRK3-SCAPER gene fusion.

Volumetric measurement of the acetabular cavity in patients with unilateral neglected developmental dysplasia of the dislocated hip operated in a single time.

BACKGROUND: Plain radiography is the most often imaging method used for postoperative assessment of inveterate developmental dysplasia of the hip. This technique does not permit to achieve an accurate diagnose of intra-articular changes, specifically articular congruity. OBJECTIVE: analyze the morphological changes of the acetabular volume by computed tomography, in patients operated by medium adductor myotomy, psoas tenotomy, open hip reduction, diaphysectomy, varus osteotomy and derotating and Dega-type acetabuloplasty. METHOD: A pilot clinical trial was conducted including six patients with unilateral inveterate dysplasia admitted to the Rehabilitation National Institute. Computed tomography were analyzed using an engineering design software. RESULTS: It was found that in all cases analyzed, operated acetabular volume was greater than the contralateral (8 to 48%), however, no significant difference between the volumes was found (p = 2.46). Significant difference between the volume and the age of patients, in multifactorial ANOVA tests (p = 0.006), Cochran's (p = 0.00019) and Kruskal-Wallis (p = 2.925 × 10-8) was found. CONCLUSION: It is clear that the proposed measurement technique is able to identify differences between volumes (operated and contralateral). The clinical monitoring of these patients can validate the results obtained by this measurement technique, and it will serve to estimate the effectiveness of the surgical technique applied in patients.

ANTECEDENTES: El método más utilizado para la evaluación posquirúrgica de la displasia del desarrollo de la cadera inveterada es la radiografía convencional, lo que impide medir con precisión cambios intraarticulares. OBJETIVO: Analizar los cambios morfológicos del volumen acetabular mediante tomografía computarizada en pacientes operados con miotomía de aductor mediano, tenotomía de psoas, reducción abierta de cadera, diafisectomía, osteotomía varizante y desrotadora, y acetabuloplastia tipo Dega. MÉTODO: Se realizó un estudio piloto en el que se analizaron tomografías de seis pacientes del Instituto Nacional de Rehabilitación con displasia inveterada unilateral, por medio de software de diseño para determinar el volumen acetabular. RESULTADOS: Se encontró que el volumen acetabular operado fue mayor que el contralateral (8 vs. 48%), pero no se halló diferencia significativa entre los volúmenes (p = 2.46). Se encontraron diferencias significativas entre los volúmenes y la edad de los pacientes, evaluadas mediante ANOVA multifactorial (p = 0.006), Cochran (p = 2.925 × 10−8) y Kruskal-Wallis (p = 0.00019). CONCLUSIÓN: Es claro que la técnica de medición propuesta permite identificar diferencias entre volúmenes (operado y contralateral). El seguimiento clínico de estos pacientes podrá validar los resultados obtenidos por este método y servirá para poder estimar la eficacia de la técnica quirúrgica aplicada en los pacientes.

Selección de lo mejor del año 2017 en hipertensión pulmonar / Selection of the best of 2017 in pulmonary hypertension

No disponible

Polifarmacia en el adulto mayor: ¿es posible su prevención? / Poly-pharmacy in the aged adult: is it its prevention possible?

Los adultos mayores generalmente presentan reacciones adversas debido a la polifarmacia que utilizan por la asociación de varias enfermedades que existen por la edad, alteraciones en la fármaco-cinética y la fármaco-dinámica de los medicamentos. Evaluar el estado de la polifarmacia, fármaco-vigilancia y posología geriátrica para poder prevenir el uso inadecuado de fármacos. Se realiza un estudio observacional prospectivo del estado de la fármaco-vigilancia en el adulto mayor que es admitido en el Hospital Provincial Clínico Quirúrgico Dr León Cuervo Rubio, de Pinar del Río en el periodo de enero a julio de 2013. Se determina que no se aplica fármaco vigilancia por el personal de enfermería en 12, 60 por ciento y el 50 por ciento tiene necesidades de aprendizaje, el comienzo de los síntomas no fue posible determinarlo y la gravedad prevaleció en los antibióticos. Los eventos adversos mas reportados fueron en los pacientes mayores de 65 años. Se revisa la calidad de la prescripción médica, adherencia farmacológica y posología, observándose que hubo indicación justificada y dosificación geriátrica en la mayoría de los pacientes. Se detecta una pobre percepción de las reacciones adversas a medicamentos y un subregistro de la notificación que refuerza la necesidad de establecer un programa continuo de fármaco-vigilancia y generalizar estrategias que garanticen la seguridad y racionalidad en los adultos mayores(AU)

Ages adults generally present adverse reactions due to poly-pharmacy used for the association of several diseases existing at their age, alterations in the pharmacokinetics and pharmaco-dynamics of medicaments. The objective was to evaluate the state of poly-pharmacy, pharmaco-surveillance and geriatric posology to prevent the medication improper consumption. A prospective observational study was carried out of the state of pharmaco-surveillance in the aged adult admitted into the Pinar del Rio Dr León Cuervo Rubio Clinical Surgical Provincial Teaching Hospital, in the period from January to July 2013. It has been determined that pharmaco-surveillance is not applied by the nursing staff in the 12.6 per cent, while the 50 per cent has learning needs, it was not possible to determine the onset of symptoms, and seriousness prevailed among antibiotics. The most reported adverse effects were in the patient over 65 years of age. The quality of the medical prescription, medication adherence and posology were reviewed, concluding that there were justified prescription and geriatric dosing in the majority of the patients. It was detected a poor perception of adverse reactions to medications and a low record of notification reinforcing the need for establishing a continual program of pharmaco-surveillance and the generalization of strategies guaranteeing the security and rationality of the aged adults(AU)

Polifarmacia en el adulto mayor: ¿es posible su prevención? / Poly-pharmacy in the aged adult: is it its prevention possible?

Introducción: los adultos mayores generalmente presentan reacciones adversas debido a la polifarmacia que utilizan por la asociación de varias enfermedades que existen por la edad, alteraciones en la fármaco-cinética y la fármaco-dinámica de los medicamentos. Objetivo: evaluar el estado de la polifarmacia, fármaco-vigilancia y posología geriátrica para poder prevenir el uso inadecuado de fármacos. Material y método: se realiza un estudio observacional prospectivo del estado de la fármaco-vigilancia en el adulto mayor que es admitido en el Hospital Provincial Clínico Quirúrgico Dr. León Cuervo Rubio, de Pinar del Río en el periodo de enero a julio de 2013. Resultados: se determina que no se aplica fármaco vigilancia por el personal de enfermería en 12, 60% y el 50% tiene necesidades de aprendizaje, el comienzo de los síntomas no fue posible determinarlo y la gravedad prevaleció en los antibióticos. Los eventos adversos mas reportados fueron en los pacientes mayores de 65 años. Se revisa la calidad de la prescripción médica, adherencia farmacológica y posología, observándose que hubo indicación justificada y dosificación geriátrica en la mayoría de los pacientes. Conclusiones: se detecta una pobre percepción de las reacciones adversas a medicamentos y un subregistro de la notificación que refuerza la necesidad de establecer un programa continuo de fármaco-vigilancia y generalizar estrategias que garanticen la seguridad y racionalidad en los adultos mayores.

Introduction: ages adults generally present adverse reactions due to poly-pharmacy used for the association of several diseases existing at their age, alterations in the pharmacokinetics and pharmaco-dynamics of medicaments. Objective: to evaluate the state of poly-pharmacy, pharmaco-surveillance and geriatric posology to prevent the medication improper consumption. Method: a prospective observational study was carried out of the state of pharmaco-surveillance in the aged adult admitted into the Pinar del Rio Dr. León Cuervo Rubio Clinical Surgical Provincial Teaching Hospital, in the period from January to July 2013. Results: it has been determined that pharmaco-surveillance is not applied by the nursing staff in the 12.6%, while the 50% has learning needs, it was not possible to determine the onset of symptoms, and seriousness prevailed among antibiotics. The most reported adverse effects were in the patient over 65 years of age. The quality of the medical prescription, medication adherence and posology were reviewed, concluding that there were justified prescription and geriatric dosing in the majority of the patients. Conclusions: it was detected a poor perception of adverse reactions to medications and a low record of notification reinforcing the need for establishing a continual program of pharmaco-surveillance and the generalization of strategies guaranteeing the security and rationality of the aged adults.

Chlorido{1-[(dimethylamino)methyl]ferrocenyl-κ(2) C (2),N}(tri-phenyl-stibine-κSb)palladium(II).

In the title compound, [FePdCl(C5H5)(C8H11N)(C18H15Sb)], obtained by reaction of diphen-yl(N,N-di-methyl-amino-methyl-ferrocen-yl)stibine with sodium tetra-chlorido-palladate(II) in acetone, the Pd(II) atom is coordinated in a slightly distorted square-planar geometry by a C atom of the ferrocenyl ring, and by N, Cl and Sb atoms. The Sb and N atoms are trans to each other.

Modelo de sistema basado en conocimiento para apoyo en la investigación y p'roceso clínico de la diabetes / Knowledge-based system model to support diabetes research and clinical process

Due to the great amount of information generated and supported by the explosive evolution of computer science systems since the end of the last century, the expansion and transference of scientific knowledge has caused a rapid transformation of scientific discoveries in products and applications that have positive effects in the life quality of societies. Today, a great amount of data in medicine is obtained by the application of biotechnological methods that constantly evolve. Thus, scientific research related to diabetes keeps improving. In this context, productivity and competitiveness must be sustained on knowledge which facilitates and encourages organizational innovation capacity. For this reason, knowledge based systems emerge as a useful tool to help organizations solve difficult assignments or improve their processes. In this work, derivate from known diabetes group of symptoms and interactions that diabetes research maintains with the biotechnological processes, the authors carried out a brief analysis of the knowledge involved as well as the role that knowledge-based systems have played, and keep playing in support of them. Additionally, with the systemic perspective obtained by the authors regarding aspects like knowledge, practices and resources needed in clinical and laboratory practices, they propose a systemic model that can support diabetes research and clinical process.

Debido a la gran cantidad de información generada y apoyada por la evolución explosiva de sistemas de la ciencia computacional, desde finales del siglo pasado, la expansión y transferencia de conocimiento científico ha provocado una rápida transformación de los descubrimientos científicos en productos y aplicaciones que afectan positivamente la calidad de vida de las sociedades. Actualmente, una gran cantidad de datos en medicina se obtiene por la aplicación de métodos biotecnológicos que constantemente evolucionan. De igual manera, la investigación científica sobre diabetes mantiene una mejora constante. En este contexto, tanto la productividad como la competitividad se deben apoyar con conocimiento que facilite y promueva la capacidad de innovación organizacional. Por esta razón, los sistemas basados en conocimiento emergen como una herramienta útil para coadyuvar con las organizaciones en la solución de situaciones difíciles o en la mejora de sus procesos. En este trabajo, derivado del conocido grupo de síntomas y de las interacciones que la investigación en diabetes mantiene con los procesos biotecnológicos, los autores realizan un breve análisis del conocimiento implicado y del rol que los sistemas basados en el conocimiento han desempeñado, -y continúan desempeñando, en apoyo a tales procesos. Adicionalmente, con la perspectiva sistémica obtenida por los autores respecto al conocimiento y recursos necesarios en prácticas clínicas y de laboratorio, proponen un modelo sistémico capaz de apoyar la investigación y el proceso clínico de la diabetes.

Cyclometalated [Os(C-N)x(N-N)(3-x)]m+ mimetics of tris(2,2'-bipyridine)osmium(II): covering a 2 V potential range by known (x = 0, 1) and new (x = 2, 3) species (C-N = o-2-phenylpyridinato).

Electrochemical studies of [Os(C-N)(x)(N-N)(3-x)](m+) (1) consisting of known Os(II) species with x = 0 (a) and 1 (b) and crystallographically characterized new Os(III) bis- and tris-metalacycles with x = 2 (c) and 3 (d) (N-N = 2,2'-bipyridine, (-)C-N = 2-phenylpyridinato) revealed a Nernstian behavior in MeCN. A stepwise replacement of neutral N-N ligands by three anionic C-N donors covers a 2 V potential range from -1 to +1 V vs. Ag/AgCl for the Os(III)/Os(II) feature.

Heptacoordinate tin(IV) compounds derived from pyridine Schiff bases: synthesis, characterization, in vitro cytotoxicity, anti-inflammatory and antioxidant activity.

Tin(IV) complexes 2a--q derived from pyridine Schiff bases were prepared and characterized. Four complexes of this series were evaluated in vitro against different carcinogenic cell lines; besides their anti-inflammatory and antioxidant properties were also tested. Combination of mass spectrometry, multinuclear NMR and X-ray diffraction techniques evidenced the formation of heptacoordinated monomeric species. The X-ray diffraction analysis of 2a, 2b, 2i, 2j and 2n led to establish the heptacoordination around the tin atom in solid state and also revealed that the ligand occupies the equatorial positions of the distorted pentagonal bipyramidal geometry and the two alkyl or aryl groups the axial positions. The in-vitro study for complexes 2a--d against six tumor cell lines showed varied antiproliferative activity, the IC50 for all tested complexes was lower than that of the cis-platin. Compounds 2a--d also exhibited anti-inflammatory activity where complex 2c resulted to be more active (IC50=0.11 microM) than the indomethacin IC50=0.27 microM which was used as reference. The antioxidant activity in rat brain homogenate on inhibition of thiobarbituric acid reactive substances (TBARS) indicated that 2c (IC50=1.77 microM) is more active than the quercetine (4.11 microM) and alpha-tocopherol (IC50=569.09 microM).

Easy access to bio-inspired osmium(II) complexes through electrophilic intramolecular C(sp2)-H bond cyclometalation.

Mild electrophilic C(sp2)-H cyclometalation of 2-phenylpyridine and N,N-dimethylbenzylamine by the chloro-bridged osmium(II) dimer [OsCl(micro-Cl)(eta6-C6H6)]2 in acetonitrile affords cyclometalated pseudotetrahedral OsII complexes [Os(C approximately N)(eta6-C6H6)(NCMe)]PF6 (C approximately N=o-C6H4py-kappa C,N (2) and o-C6H4CH2NMe2-kappa C,N (5), respectively) in good to excellent yields. The cyclometalation reactions are super sensitive to the nature of an external base. Sodium hydroxide is essential for cyclometalation of 2-phenylpyridine, but NaOH retards metalation of N,N-dimethylbenzylamine, the tertiary amine being self-sufficient as a base. Further reactions of compounds 2 and 5 with 1,10-phenanthroline or 2,2'-bipyridine (N approximately N) lead to the substitution of the eta6-bound benzene to produce octahedral species [Os(C approximately N)(N approximately N)(NCMe)2]PF6 or [Os(C approximately N)(N approximately N)2]PF6 in MeCN or MeOH as solvent, respectively. The cis configuration of the MeCN ligands in [Os(C approximately N)(phen)(NCMe)2]PF6 has been confirmed by an X-ray crystallographic study. Electrochemical investigation of the octahedral osma(II)cycles by cyclic voltammetry showed a pseudoreversible MIII/II redox feature at (-50)-(+109) and 190-300 mV versus Ag/AgCl in water and MeCN, respectively. As a possible application of the compounds, a rapid electron exchange between the reduced active site of glucose oxidase enzyme from Aspergillus niger and the electrochemically generated OsIII species has been demonstrated. The corresponding second-order rate constants cover the range (0.7-4.8)x10(6) M(-1) s(-1) at 25 degrees C and pH 7.

Synthesis, characterization, and electrochemistry of biorelevant photosensitive low-potential orthometalated ruthenium complexes.

Redox potentials of photosensitive cyclometalated RuII derivatives of 2-phenylpyridine or 2-(4-tolyl)pyridine are controllably decreased by up to 0.8 V within several minutes. This is achieved by irradiation of the ruthena(II)cycles cis-[Ru(o-X-2-py)(LL)(MeCN)2]PF6 (2, X = C6H4 (a) or 4-MeC6H3 (b), LL = 1,10-phenanthroline or 2,2'-bipyridine). The cis geometry of the MeCN ligands has been confirmed by the X-ray structural studies. The sigma-bound sp2 carbon of the metalated ring is trans to LL nitrogen. Complexes 2 are made from [Ru(o-X-2-py)(MeCN)4]PF6 (1) and LL. This "trivial" ligand substitution is unusual because 1a reacts readily with phen in MeCN as solvent to give cis-[Ru(o-C6H4-2-py)(phen)(MeCN)2]PF6 (2c) in a 83% yield, but bpy does not afford the bpy-containing 2 under the same conditions. cis-[Ru(o-C6H4-2-py)(bpy)(MeCN)2]PF6 (2e) has been prepared in CH2Cl2 (74%). Studies of complexes 2c,e by cyclic voltammetry in MeOH in the dark reveal RuII/III quasy-reversible redox features at 573 and 578 mV (vs Ag/AgCl), respectively. A minute irradiation 2c and 2e converts them into new species with redox potentials of -230 and 270 mV, respectively. An exceptional potential drop for 2c is accounted for in terms of a photosubstitution of both MeCN ligands by methanol. ESR, 1H NMR, and UV-vis data indicate that the primary product of photolysis of 2c is an octahedral monomeric low-spin (S = 1/2) RuIII species, presumably cis-[RuIII(o-C6H4-2-py)(phen)(MeOH)2]2+. The primary photoproduct of bpy complex 2e is cis-[RuII(o-C6H4-2-py)(bpy)(MeCN)(MeOH)]+, and this accounts for a lower decrease in the redox potential. Irradiation of 2c in the presence of added chloride affords [(phen)(o-C6H4-2-py)ClRuIIIORuIVCl(o-C6H4-2-py)(phen)]PF6, a first mu-oxo-bridged mixed valent dimer with a cyclometalated unit. The structure of the dimer has been established by X-ray crystallography.