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1.
Chem Commun (Camb) ; 56(76): 11219-11222, 2020 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-32818220

RESUMO

By exploiting an established on-surface metallation strategy, we address the ability of the corrolic macrocycle to stabilise transition metal ions in high-valent (III) oxidation states in metal-supported molecular layers. This approach offers a route to engineer adsorbed metal complexes that cannot be easily fabricated by organic synthesis methods and bear a vacant axial coordination site for catalytic conversions.

2.
J Chem Phys ; 150(9): 094702, 2019 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-30849887

RESUMO

We have experimentally determined the lateral registry and geometric structure of free-base porphine (2H-P) and copper-metalated porphine (Cu-P) adsorbed on Cu(111), by means of energy-scanned photoelectron diffraction (PhD), and compared the experimental results to density functional theory (DFT) calculations that included van der Waals corrections within the Tkatchenko-Scheffler approach. Both 2H-P and Cu-P adsorb with their center above a surface bridge site. Consistency is obtained between the experimental and DFT-predicted structural models, with a characteristic change in the corrugation of the four N atoms of the molecule's macrocycle following metalation. Interestingly, comparison with previously published data for cobalt porphine adsorbed on the same surface evidences a distinct increase in the average height of the N atoms above the surface through the series 2H-P, Cu-P, and cobalt porphine. Such an increase strikingly anti-correlates the DFT-predicted adsorption strength, with 2H-P having the smallest adsorption height despite the weakest calculated adsorption energy. In addition, our findings suggest that for these macrocyclic compounds, substrate-to-molecule charge transfer and adsorption strength may not be univocally correlated.

3.
Langmuir ; 34(15): 4548-4553, 2018 04 17.
Artigo em Inglês | MEDLINE | ID: mdl-29551068

RESUMO

Chiroptical methods have been proven to be superior compared to their achiral counterparts for the structural elucidation of many compounds. To expand the use of chiroptical systems to everyday applications, the development of functional materials exhibiting intense chiroptical responses is essential. Particularly, tailored and robust interfaces compatible with standard device operation conditions are required. Herein, we present the design and synthesis of chiral allenes and their use for the functionalization of gold surfaces. The self-assembly results in a monolayer-thin room-temperature-stable upstanding chiral architecture as ascertained by ellipsometry, X-ray photoelectron spectroscopy, and near-edge X-ray absorption fine structure. Moreover, these nanostructures anchored to device-compatible substrates feature intense chiroptical second harmonic generation. Both straightforward preparation of the device-compatible interfaces along with their chiroptical nature provide major prospects for everyday applications.

4.
Chemistry ; 24(26): 6787-6797, 2018 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-29493819

RESUMO

We demonstrate here that theory-assisted near-edge X-ray absorption fine-structure (NEXAFS) spectroscopy enables the site-sensitive monitoring of on-surface chemical reactions, thus, providing information not accessible by other techniques. As a prototype example, we have used free-base 5,10,15-tris(pentafluorophenyl)corroles (3H-TpFPC) adsorbed on Ag(111) and present a detailed investigation of the angle-dependent NEXAFS of this molecular species as well as of their thermally induced derivatives. For this, we have recorded experimental C and N K-edge NEXAFS spectra and interpret them based on XAS cross-section calculations by using a continuous fraction approach and core-hole including multiprojector PAW pseudopotentials within DFT. We have characterized the as-deposited low temperature (200 K) phase and unraveled the subsequent changes induced by dehydrogenation (at 330 K) and ring-closure reactions (at 430 K). By exemplarily obtaining profound insight into the on-surface chemistry of free-base corrolic species adsorbed on a noble metal this work highlights how angle-dependent XAS combined with accurate theoretical modeling can serve for the investigation of on-surface reactions, whereby even highly similar molecular structures, such as tautomers and isomers, can be distinguished.

5.
Rev. argent. radiol ; 81(4): 262-269, dic. 2017. ilus, graf, tab
Artigo em Espanhol | LILACS | ID: biblio-897425

RESUMO

Objetivos: Determinar la precisión de la angiotomografía renal (ATR) en la evaluación del sistema arterial y las variantes anatómicas en el donante vivo, con la correlación con su ablación quirúrgica. Materiales y métodos: Se evaluaron retrospectivamente los pacientes sometidos a nefrectomía laparoscópica como donantes vivos renales y sus ATR, entre 2014 y 2016 en nuestra Institución. Se utilizó análisis estadístico descriptivo para presentar los resultados. En la ATR se evaluaron: número de arterias renales principales, presencia y número de arterias polares y alteraciones del calibre de la arteria renal. Resultados: Se incluyeron 21 pacientes sometidos a nefrectomía laparoscópica como donantes vivos, 10 mujeres y 11 hombres (entre 23 y 61 años). En todos los casos se realizó la ablación del riñón izquierdo. De los 21 pacientes analizados, 15 no presentaron variantes anatómicas ni alteraciones del calibre en la ATR (una arteria renal principal, sin polares). Estos mismos hallazgos se certificaron en la ablación. En un caso, la ATR observó doble arteria renal principal con el mismo hallazgo quirúrgico; y en tres casos la ATR reconoció una única arteria polar, las cuales se corroboraron en la ablación. En estos 19 casos se demostró correlación entre la ATR y la ablación, con una precisión del 90,4% En los 2 casos restantes, hubo discrepancias. Conclusión: El conocimiento detallado del sistema arterial es necesario para la planificación quirúrgica de la nefrectomía laparoscópica del donante vivo renal. La angiotomografía renal constituye el método de elección para su evaluación, demostrando muy buena correlación entre sus hallazgos y los de la ablación.


Objective: To determine the accuracy of computed tomography renal angiography (CTRA) in the assessment and diagnosis of arterial vascular anatomy of the kidney and its variations in living kidney donors, with its correlation in harvesting kidneys. Materials and methods: Patients who had undergone laparoscopic nephrectomy as living kidney donors and their CTRA were retrospectively evaluated between 2014 and 2016 in our institution. Results are presented using statistical descriptive analysis. The following were assessed in the CTRA report: number of main renal arteries, presence and number of accessory polar arteries, and anomalies related to renal artery calibre. Results: Of the 21 patients that had undergone laparoscopic nephrectomy as living donors, there were 10 female and 11 male donors (age range 23 - 61 years). Renal harvesting included left kidney in all cases. In 15 cases, no anatomical variations or arterial renal dilations were found in computed tomography renal angiography (CTRA): (one main renal artery, without accessories arteries). The same findings were certified during the surgery. In one case CTRA showed a double renal artery, and the same finding occurred in the surgical harvesting; and three cases in which one single polar accessory artery was certified at surgery. An overall accuracy of 90.4% for CTRA was obtained in 19 cases. In the remaining 2 cases, a discrepancy was found. Conclusion: Detailed knowledge of the renal arterial anatomy is important for the preoperative evaluation of the laparoscopic nephrectomy in living renal donors. Computed tomography renal angiography (CTRA) is the technique of choice for these patients, as it demonstrates a high correlation between tomography findings and surgery harvesting.


Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Angiografia por Tomografia Computadorizada/métodos , Transplante de Rim , Doadores Vivos , Artéria Renal/transplante , Interpretação Estatística de Dados
6.
Phys Chem Chem Phys ; 19(12): 8282-8287, 2017 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-28277577

RESUMO

Single-molecule magnets based on lanthanide double-deckers are attracting significant attention due to their unrivaled single-ion anisotropy. To exploit their fascinating electronic and magnetic properties in devices for information storage or spin transport, studies on the preservation or variation of electronic and magnetic functionalities upon adsorption on surfaces are necessary. Herein, we introduced a comprehensive scanning tunneling microscopy (STM) and X-ray photoelectron spectroscopy (XPS) surface science study, complemented by density functional theory (DFT) simulations, of a recently synthesized single-molecule magnet based on porphyrazine deckers, conveniently equipped with ethyl moieties to make them soluble and sublimable. We demonstrated that the double-decker species were intactly adsorbed on Au(111), Ag(111), and Cu(111) in a flat-on fashion and self-assembled in hexagonal close-packed layers. Systematic multi- and monolayer XPS was performed on the surface-confined species, confirming the preservation of the electronic properties of the ligands and the lanthanide center upon adsorption.

7.
Rev. argent. radiol ; 80(2): 127-135, jun. 2016. ilus
Artigo em Espanhol | LILACS | ID: biblio-843215

RESUMO

La ecografía es el método de elección para la evaluación inicial de las partes blandas y el sistema muscular, siendo una técnica accesible, portátil y de bajo costo. Sin embargo, ha sido excluida de la exploración y evaluación de las patologías óseas debido a la idea de que es incapaz de penetrar la superficie del hueso. De hecho, muchos radiólogos admiten que esta es una de las pocas localizaciones donde la ecografía no resulta efectiva. Si bien algunos de estos conceptos son ciertos, este método puede aportar valiosa información diagnóstica sobre el estado del hueso, principalmente sobre la cortical ósea, en variadas circunstancias. La ecografía de la cortical ósea es posible por el artefacto de reflexión hiperecogénico lineal y regular que esta genera. En manos experimentadas, el reconocimiento y exploración de la superficie ósea permiten obtener datos muy útiles. Los tumores óseos generan reacciones periósticas fácilmente observables y caracterizables por ultrasonido, con la ventaja adicional de que el Doppler color identifica la vascularización del tumor. Las fracturas se observan como disrupciones de la cortical y la patología degenerativa se puede sospechar ante irregularidades corticales. Asimismo, es posible reconocer patologías como avulsiones, callos óseos de procesos previos e incluso fracturas por estrés. En este ensayo iconográfico mostramos diferentes casos de ecografías de partes blandas que evidenciaron hallazgos patológicos en la cortical ósea, permitiendo arribar a un diagnóstico o guiando en la elección de un estudio adicional.


Ultrasound is the best choice to evaluate soft tissues and the muscular system because of its accessibility, low cost and portability. Historically, the assumption has been that because ultrasound waves cannot penetrate bone, it is not useful in the evaluation of the skeletal system and its diseases. Radiologists admit that one of the very few tissue types which ultrasound cannot evaluate is bone. There is, of course, much truth in this, but recent studies suggest that ultrasound can provide valuable diagnostic information regarding the state of bone in some circumstances. The high reflectivity of sound at the bone-soft tissue interface is what allows the bone surface to be visualised. Valuable diagnostic information can be obtained by exploring bone surface in detail. The fact that bone tumours manifest themselves as periosteal reactions makes them easily recognisable by ultrasound, with the additional advantage if using Doppler colour. Bone fractures could be seen as interruptions of the bone continuity, and degenerative diseases should be suspected when an irregular surface is observed. Likewise, other pathologies such as avulsion fractures, bone callus stemming from previous processes, and even stress fractures can be identified. In this pictorial essay different cases are presented of musculoskeletal ultrasound in which bone surface was evaluated and abnormalities discovered, making a diagnosis or suggesting an additional test.


Assuntos
Humanos , Ultrassonografia , Osso Cortical/diagnóstico por imagem , Neoplasias de Tecidos Moles , Ultrassonografia Doppler em Cores , Ultrassonografia Doppler , Mãos/diagnóstico por imagem
8.
Phytomedicine ; 19(14): 1285-7, 2012 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-22951394

RESUMO

The aim of the present report was to evaluate antimicrobial/anti-biofilm activity of 7-(2-oxohexyl)-taxodione, a novel taxodione derivative isolated from n-hexane extract of Salvia austriaca hairy roots. Antimicrobial assays showed that 7-(2-oxohexyl)-taxodione was at least 4 times more active than taxodione against methicillin-susceptible as well against methicillin-resistant staphylococci with MIC of 1.25-2.5 µgml(-1). This compound was less active against vancomycin-resistant enterococci (VRE), on the same level as taxodione (MIC ranged 10.0-20.0 µgml(-1)). The presence of 7-(2-oxohexyl)-taxodione in the culture medium (at MIC, ½ MIC or » MIC) decreased adhesion of staphylococci to abiotic surfaces, which in turn caused a reduction in biofilm formation during 24h, by approximately 25-30%. Also, the extent of established biofilm eradication was found to be significant, although it required an increased concentration of the compound. This is the first report on the antimicrobial activity of this, up to now not known compound, isolated from transformed roots of S. austriaca.


Assuntos
Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Diterpenos/farmacologia , Fenantrenos/farmacologia , Extratos Vegetais/farmacologia , Salvia/química , Staphylococcus/efeitos dos fármacos , Antibacterianos/isolamento & purificação , Aderência Bacteriana/efeitos dos fármacos , Diterpenos/isolamento & purificação , Enterococcus/efeitos dos fármacos , Resistência a Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Fenantrenos/isolamento & purificação , Extratos Vegetais/química , Raízes de Plantas/química , Staphylococcus/patogenicidade , Resistência a Vancomicina/efeitos dos fármacos
9.
Bull Entomol Res ; 102(4): 453-60, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22273154

RESUMO

The composition of cuticular and internal n-alkanes in Lucilia sericata larvae, pupae, and male and female imagines were studied. The cuticular and internal lipid extracts were separated by HPLC-LLSD, after which the hydrocarbon fraction was identified by GC/MS in selected ion monitoring (SIM) and total ion current (TIC) modes. The cuticular lipids of the larvae contained seven n-alkanes from C23 to C31. The major n-alkane in L. sericata larvae was C29 (42.1%). The total cuticular n-alkane content in the cuticular lipids was 31.46 µg g-1 of the insect body. The internal lipids of L. sericata larvae contained five n-alkanes ranged from C25 to C31. The most abundant compound was C27 (61.71 µg g-1 of the insect body). Eighteen n-alkanes from C14 to C31 were identified in the cuticular lipids of the pupae. The most abundant n-alkanes ranged from C25 to C31; those with odd-numbered carbon chains were particularly abundant, the major one being C29:0 (59.5%). Traces of eight cuticular n-alkanes were present. The internal lipids of L. sericata pupae contained five n-alkanes, ranging from C25 to C31. The cuticular lipids of female imagines contained 17 n-alkanes from C12 to C30. Among the cuticular n-alkanes of females, C27 (47.5%) was the most abundant compound. Four n-alkanes, with only odd-numbered carbon chains, were identified in the internal lipids of females. The lipids from both sexes of L. sericata had similar n-alkane profiles. The cuticular lipids of adult males contained 16 n-alkanes ranging from C13 to C31. C27 (47.9%) was the most abundant cuticular n-alkanes in males. The same n-alkanes only with odd-numbered carbon chains and in smaller quantities of C27 (0.1%) were also identified in the internal lipids of males. The highest amounts of total cuticular n-alkanes were detected in males and females of L. sericata (330.4 and 158.93 µg g-1 of the insect body, respectively). The quantities of total cuticular alcohols in larvae and pupae were smaller (31.46 µg g-1 and 42.08 µg g-1, respectively). The internal n-alkane contents of larvae, pupae, and male and female imagines were significantly higher than the cuticular n-alkane contents (153.53, 99.60, 360.06 and 838.76 µg g-1 of the insect body, respectively).


Assuntos
Alcanos/análise , Dípteros/química , Larva/química , Pupa/química , Animais , Composição Corporal , Cromatografia Líquida de Alta Pressão/métodos , Feminino , Cromatografia Gasosa-Espectrometria de Massas/métodos , Lipídeos/análise , Masculino
10.
Klin Oczna ; 94(5-6): 161-2, 1992.
Artigo em Polonês | MEDLINE | ID: mdl-1453681

RESUMO

Twenty four patients with retinal pigment dystrophy were subjected to examination of pupillary reaction. Evaluated was the amplitude of pupillary reaction on a standard light flash. The results received were compared with the field changes. It was noted that the amplitude is diminished depending on the changes in the visual field.


Assuntos
Reflexo Pupilar/fisiologia , Retinose Pigmentar/diagnóstico , Acuidade Visual/fisiologia , Campos Visuais/fisiologia , Adolescente , Adulto , Criança , Eletrorretinografia , Humanos , Luz , Pessoa de Meia-Idade , Retinose Pigmentar/fisiopatologia
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