A tetraiodo cuprate NHC-MIC biscarbene proligand: coordination chemistry and preliminary catalysis

La preparación de una sal híbrida conteniendo cationes imidazolio/triazolio [NHC-MIC]²+ fue llevada a cabo en tres pasos sintéticos utilizando la cicloadición de azida-alquino catalizada por cobre (CuAAC) y la subsecuente N-metilación del 1,2,-3 triazol. Deprotonación selectiva de la sal mixta con NaH en presencia de un precursor metálico (M= Pd, Rh) permite la síntesis de NHC-metálicos conteniendo fragmentos catiónicos de tipo triazolio [NHC∙(M)-MIC]+. La subsecuente deprotonación del triazolio con KOᵗBu en presencia de Mpermite entonces la síntesis de complejos inusuales tipo quelato conteniendo carbenos clásicos tipo NHC y carbenos mesoiónicos MIC con estructura general [NHC∙(M)∙MIC]+MX₂-. Todos los compuestos han sido caracterizados mediante RMN de ¹H y ¹³C, FT-IR y cristalografía de rayos-X de monocristal. Estudios catalíticos preliminares de los nuevos complejos en procesos de formación de α-cetoamidas serán discutidos.A novel linked imidazolium/triazolium salt [NHC-MIC]²+ was preparedin three synthetic stepsusing copper catalyzed alkyne azide cycloaddition (CuAAC) and N-methylation protocols. Metallation of the imidazolium moiety using KHMDS in presence of a metallic precursor (M = Pd, Rh) yields NHC-anchored/pendent triazolium species [NHC∙(M)-MIC]+ in good yields. The subsequent deprotonation of the triazolium fragment with KOᵗBu in presence of one equivalent of M delivers the rare chelating mixed classical NHC/mesionic biscarbene complexes with the general formula [NHC∙(M)∙MIC]+MX₂-. All the complexes were fully characterized by ¹H and ¹³C NMR, FT-IR and single crystal X-ray diffraction. Preliminary catalytic performances of the new complexes in the oxidativepreparation of α-ketoamides will be discussed

Determination of plasma frequency, damping constant, and size distribution from the complex dielectric function of noble metal nanoparticles

This paper develops a novel method for simultaneously determining the plasma frequency ωP  ωP   and the damping constant γfreeγfree in the bulk damped oscillator Drude model, based on experimentally measured real and imaginary parts of the metal refractive index in the IR wavelength range, lifting the usual approximation that restricts frequency values to the UV-deep UV region. Our method was applied to gold, silver, and copper, improving the relative uncertainties in the final values for ωpωp (0.5%–1.6%) and for γfreeγfree (3%–8%), which are smaller than those reported in the literature. These small uncertainties in ωpωp and γfreeγfree determination yield a much better fit of the experimental complex dielectric function. For the case of nanoparticles (Nps), a series expansion of the Drude expression (which includes ωpωp and γfreeγfree determined using our method) enables size-dependent dielectric function to be written as the sum of three terms: the experimental bulk dielectric function plus two size corrective terms, one for free electron, and the other for bound-electron contributions. Finally, size distribution of nanometric and subnanometric gold Nps in colloidal suspension was determined through fitting its experimental optical extinction spectrum using Mie theory based on the previously determined dielectric function. Results are compared with size histogram obtained from Transmission Electron Microscopy (TEM).Fil: Mendoza Herrera, Luis Joaquin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Centro de Investigaciones Opticas (i); Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; Argentina. Universidad Nacional de La Plata; ArgentinaFil: Muñetón Arboleda, David. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Centro de Investigaciones Opticas (i); Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; Argentina. Universidad Nacional de La Plata; ArgentinaFil: Schinca, Daniel C.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Centro de Investigaciones Opticas (i); Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; Argentina. Universidad Nacional de La Plata. Facultad de Ingenieria; ArgentinaFil: Scaffardi, Lucia Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Centro de Investigaciones Opticas (i); Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; Argentina. Universidad Nacional de La Plata. Facultad de Ingenieria; Argentin

Centerscope

Centerscope, formerly Scope, was published by the Boston University Medical Center "to communicate the concern of the Medical Center for the development and maintenance of improved health care in contemporary society.

Anomalous ocean load tide signal observed in lake-level variations in Tierra del Fuego

We demonstrate the application of a 100 km long lake as a sensor for studying the tidal effects on Tierra del Fuego main island. The lake-level variations observed in Lago Fagnano reflect both the direct response to the tidal potential and the indirect effect of the ocean tidal loading. Modeling both contributions explains the observed tidal signal in the lake to about 70%. Underestimated model load tide amplitudes are found to be probably responsible for the remaining difference. We interpret this discrepancy as a hint for regional elastic lithosphere properties differing substantially from those represented by currently available global models.Fil: Richter, Andreas Jorg. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Technische Universität Dresden; AlemaniaFil: Hormaechea, José Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Dietrich, R.. Technische Universität Dresden; AlemaniaFil: Perdomo, Raul Anibal. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Departamento de Astrometría; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Fritsche, M.. Technische Universität Dresden; AlemaniaFil: del Cogliano, Daniel Hector. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Departamento de Astrometría; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Liebsch, G.. Bundesamt fur Kartografie und Geodasie; AlemaniaFil: Mendoza, Luciano Pedro Oscar. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Departamento de Astrometría; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentin

Brokered Graph State Quantum Computing

We describe a procedure for graph state quantum computing that is tailored to fully exploit the physics of optically active multi-level systems. Leveraging ideas from the literature on distributed computation together with the recent work on probabilistic cluster state synthesis, our model assigns to each physical system two logical qubits: the broker and the client. Groups of brokers negotiate new graph state fragments via a probabilistic optical protocol. Completed fragments are mapped from broker to clients via a simple state transition and measurement. The clients, whose role is to store the nascent graph state long term, remain entirely insulated from failures during the brokerage. We describe an implementation in terms of NV-centres in diamond, where brokers and clients are very naturally embodied as electron and nuclear spins.Comment: 5 pages, 3 figure

Failed limb salvage by microsurgery, resolved by super-microsurgery

Advances in perforating artery flaps have improved reconstruction in various body parts, particularly the lower extremities, offering benefits in patient quality of life and reduced public health service costs. The use of flaps and microsurgery extends beyond trauma to address conditions like osteomyelitis, tumor resection, osteoarthritis, and post-radiation necrosis. Notably, the superficial circumflex iliac artery perforator flap (SCIP) is highlighted for its thin profile and utility in limb coverage, minimizing donor site morbidity. Microsurgical techniques contribute to limb salvage, reducing amputation risks in severe fractures and post-osteosynthesis complications. A 29-year-old male with cerebral palsy suffered bimalleolar fracture from a high-energy motor vehicle accident. Initial ALT flap reconstruction failed, leading to flap removal and osteosynthesis exposure. After 48 hours, removal of the flap was necessary due to venous thrombosis. Salvage with SCIP flap involved anastomosis to perforators of both posterior tibial artery and vein. This case details a patient with a bimalleolar fracture post-motorcycle accident, initially treated with conventional microsurgery using an ALT flap. Complications arose from venous thrombosis, necessitating flap removal. Salvage was achieved through a SCIP flap with supermicrosurgery techniques, employing 0.5 mm anastomosis for improved functionality and reduced complications in flap recovery and donor site comorbidities. Successful outcomes in microsurgery and supermicrosurgery necessitate comprehensive training. Specialized limb salvage centers must possess specific equipment and instruments for these techniques. The literature reviewed doesn't indicate contraindications related to the patient's mental state for the execution of microsurgery and supermicrosurgery

Seroprevalence and Risk Factors for Rickettsia and Leptospira Infection in Four Ecologically Distinct Regions of Peru.

Rickettsia and Leptospira spp. are under-recognized causes of acute febrile disease worldwide. Rickettsia species are often placed into the spotted fever group rickettsiae (SFGR) and typhus group rickettsiae (TGR). We explored the antibody prevalence among humans for these two groups of rickettsiae in four regions of Peru (Lima, Cusco, Puerto Maldonado, and Tumbes) and for Leptospira spp. in Puerto Maldonado and Tumbes. We also assessed risk factors for seropositivity and collected serum samples and ectoparasites from peri-domestic animals from households in sites with high human seroprevalence. In total, we tested 2,165 human sera for antibodies (IgG) against SFGR and TGR by ELISA and for antibodies against Leptospira by a microscopic agglutination test. Overall, human antibody prevalence across the four sites was 10.6% for SFGR (ranging from 6.2% to 14.0%, highest in Tumbes) and 3.3% for TGR (ranging from 2.6% to 6.4%, highest in Puerto Maldonado). Factors associated with seroreactivity against SFGR were male gender, older age, contact with backyard birds, and working in agriculture or with livestock. However, exposure to any kind of animal within the household decreased the odds ratio by half. Age was the only variable associated with higher TGR seroprevalence. The prevalence of Leptospira was 11.3% in Puerto Maldonado and 5.8% in Tumbes, with a borderline association with keeping animals in the household. We tested animal sera for Leptospira and conducted polymerase chain reaction (PCR) to detect Rickettsia species among ectoparasites collected from domestic animals in 63 households of seropositive participants and controls. We did not find any association between animal infection and human serostatus

Comparative regulomics supports pervasive selection on gene dosage following whole genome duplication

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