An Organocopper(III) Fluoride Triggering C-CF3 Bond Formation.

Copper(III) fluorides are catalytically competent, yet elusive, intermediates in cross-coupling. The synthesis of [PPh4 ][CuIII (CF3 )3 F] (2), the first stable (isolable) CuIII -F, was accomplished via chloride addition to [CuIII (CF3 )3 (py)] (1) yielding [PPh4 ][CuIII (CF3 )3 Cl(py)] (1⋅Cl), followed by treatment with AgF. The CuIII halides 1⋅Cl and 2 were fully characterized using nuclear magnetic resonance (NMR) spectroscopy, single crystal X-ray diffraction (Sc-XRD) and elemental analysis (EA). Complex 2 proved capable of forging C-CF3 bonds from silyl-capped alkynes. In-depth mechanistic studies combining probes, theoretical calculations, trapping of intermediate 4a ([PPh4 ][CuIII (CF3 )3 (C≡CPh)]) and radical tests unveil the key role of the CuIII acetylides that undergo facile 2e- reductive elimination furnishing the trifluoromethylated alkynes (RC≡CCF3 ), which are industrially relevant synthons in drug discovery, pharma and agrochemistry.

In silico design of bio-marker detection fluorescent probes.

Fluorescent probes capable of sensing the biological medium are of utmost importance in medical diagnostics. However, the optical spectrum of such probes needs to be tuned with care for compatibility with living tissues. More specifically, fluorescent bioprobes must be adjusted so as to avoid light interference with pigments (e.g. hemoglobin), tissue photodamage, scattering of the emitted light, and autofluorescence. This leads to two important conditions on the optical spectrum of the probes. On the one hand, the emission wavelength must be in an optical window of 650 to 950 nm. On the other hand, the Stokes shift must be large, ideally greater than 150 nm. In this paper, we showcase the in-silico design of potential fluorescent biomarkers fulfilling these two conditions by means of heteroatomic substitution and conjugation on a 1,2,4-triazole core initially far away from biological standards.

Calculation of the ELF in the excited state with single-determinant methods.

Since its first definition, back in 1990, the electron localization function (ELF) has settled as one of the most commonly employed techniques to characterize the nature of the chemical bond in real space. Although most of the work using the ELF has focused on the study of ground-state chemical reactivity, a growing interest has blossomed to apply these techniques to the nearly unexplored realm of excited states and photochemistry. Since accurate excited electronic states usually require to account appropriately for electron correlation, the standard single-determinant ELF formulation cannot be blindly applied to them, and it is necessary to turn to correlated ELF descriptions based on the two-particle density matrix (2-PDM). The latter requires costly wavefunction approaches, unaffordable for most of the systems of current photochemical interest. Here, we compare the exact, 2-PDM-based ELF results with those of approximate 2-PDM reconstructions taken from reduced density matrix functional theory. Our approach is put to the test in a wide variety of representative scenarios, such as those provided by the lowest-lying excited electronic states of simple diatomic and polyatomic molecules. Altogether, our results suggest that even approximate 2-PDMs are able to accurately reproduce, on a general basis, the topological and statistical features of the ELF scalar field, paving the way toward the application of cost-effective methodologies, such as time-dependent-Hartree-Fock or time-dependent density functional theory, in the accurate description of the chemical bonding in excited states of photochemical relevance.

Capabilities of global high-level isolation units: A pre-workshop survey.

OBJECTIVE: To assess experience, physical infrastructure, and capabilities of high-level isolation units (HLIUs) planning to participate in a 2018 global HLIU workshop hosted by the US National Emerging Special Pathogens Training and Education Center (NETEC). DESIGN: An electronic survey elicited information on general HLIU organization, operating costs, staffing models, and infection control protocols of select global units. SETTING AND PARTICIPANTS: The survey was distributed to site representatives of 22 HLIUs located in the United States, Europe, and Asia; 19 (86%) responded. METHODS: Data were coded and analyzed using descriptive statistics. RESULTS: The mean annual reported budget for the 19 responding units was US$484,615. Most (89%) had treated a suspected or confirmed case of a high-consequence infectious disease. Reported composition of trained teams included a broad range of clinical and nonclinical roles. The mean number of HLIU beds was 6.37 (median, 4; range, 2-20) for adults and 4.23 (median, 2; range, 1-10) for children; however, capacity was dependent on pathogen. CONCLUSIONS: Responding HLIUs represent some of the most experienced HLIUs in the world. Variation in reported unit infrastructure, capabilities, and procedures demonstrate the variety of HLIU approaches. A number of technical questions unique to HLIUs remain unanswered related to physical design, infection prevention and control procedures, and staffing and training. These key areas represent potential focal points for future evidence and practice guidelines. These data are important considerations for hospitals considering the design and development of HLIUs, and there is a need for continued global HLIU collaboration to define best practices.

Electron Localization Function in Excited States: The Case of the Ultrafast Proton Transfer of the Salicylidene Methylamine.

The physical characterization of the chemical bond in the ground state has been a central theme to theoretical chemistry. Among many techniques, quantum chemical topology (QCT) has emerged as a robust technique to understand the features of the chemical bond and electron organization within molecules. One consolidate tool within QCT is the topological analysis of the electron localization function (ELF). Most research on ELF and chemical bond has focused either on singlet ground states or the first excited triplet. However, most photochemical reactions and photophysical processes occur in excited states with the same spin-symmetry as the ground state. In this work, we develop a proposal on how to compute the ELF in excited states of any symmetry within linear-response time-dependent density functional theory. Then, we study the evolution of the chemical bonds in the ground- and excited-state intramolecular proton transfer (ESIPT) of a prototypal Schiff base (the salicylidene methylamine). We found that the topological analysis of the ELF along reaction paths explains the presence of a barrier for the proton transfer in the ground state and the absence of it in the excited state. Briefly, in the ground state, the cleavage of the O-H bond results in a structure with high electrostatic potential energy due to an excess of electron lone-pairs (3) in the oxygen atom, which explains the barrier. In the excited state, the electronic transition promotes an enhancement of the basicity of nitrogen by allocating three nonbonding electrons in the basin of its lone-pair. This excess of electrons in the N exerts an electrostatic attraction of the proton, which we suggest as the primary driven-force of the barrierless reaction. Because in excited states the molecule can develop more vibrational kinetic energy than in the ground state, we performed an ab initio molecular dynamics of the proton transfer in the excited state and corroborate that our conclusions on the topology of the ELF do not change due to dynamic effects.

Dimers of formic acid: Structures, stability, and double proton transfer.

A stochastic search of the potential energy surface for the formic acid dimers results in 21 well-defined minima. A number of structures are reported here for the first time, others have already been experimentally detected or computationally predicted. Four types of different hydrogen bonds (HBs) are at play stabilizing the clusters: primary C=O⋯ H-O and H-O⋯ H-O and secondary C=O⋯ H-C and H-O⋯ H-C HBs corresponding to well-characterized bonding paths are identified. A novel C=O⋯ C stabilizing interaction is also reported. The double proton transfer reaction is calculated to occur in a synchronous fashion, with an energy barrier smaller than the energy needed to break up the dimers.

Cardiovascular health among Philadelphia adolescents: analysis of youth risk behaviour data, 2011.

Improving population-level cardiovascular health is a public health priority. Guided by the American Heart Association's metrics for ideal heart health, we examined the prevalence of behavioural heart health indicators using a representative sample of urban adolescents. Less than 1% (0.6%) of the sample had ideal heart health. The alarmingly low percentage of ideal behavioural heart health suggests that primary prevention approaches to address cardiovascular health in youth are warranted.

Odontología para pacientes autistas / Dentistry for the Autistic Patient

La relación entre enfermedades orales y mala higiene oral ha sido bien establecida en la literatura. Sin embargo, su relación directa con el autismo no ha sido demostrada. A pesar de su discapacidad psicomotora, el paciente autista no está limitado para utilizar los servicios odontológicos, más bien, la falta de conocimiento y entrenamiento de los odontólogos generales para la atención de este grupo de pacientes parece ser el problema. El propósito de este artículo es hacer una revisión detallada de la literatura científica existente encontrada en las principales bases de datos internacionales, con el fin de ofrecerle al odontólogo general y al odontopediatra una herramienta para el entendimiento de la condición autista, los conceptos básicos, generalidades, etiología y una detallada descripción de las condiciones orales y los distintos enfoques de tratamiento odontológico. Se describirán con detalle las técnicas de manejo del comportamiento y técnicas de comunicación necesarias para que el profesional de la salud pueda brindar una atención integral desde el punto de vista clínico y humano, teniendo en cuenta que para lograr mantener la salud y mejorar la calidad de vida de este grupo de pacientes, se requiere un enfoque multidisciplinario, donde el odontólogo es parte fundamental del grupo.

The relationship between oral diseases and poor oral hygiene has been well established, however, there is a lack of direct relation with autism. Despite their psychomotor disabilities, the autistic patient is not limited to use the dental services, in the contrary, the lack of knowledge and training of general practitioners to care for this group of patients seem to be the problem. The purpose of this article consists in a detailed scientific literature review found in the major international databases, to provide to the general dentist and the pediatric dentist a tool for understanding the autistic condition, the basic concepts, overview, etiology, and a detailed description of oral conditions and dental treatment approaches. This article describes in detail the behavior management and communication techniques necessary for the dentist to provide a comprehensive and humanized dental care, taking into account that in order to maintain health and improve quality of life, this patients require a multidisciplinary approach, where the dentist is a fundamental part of the group.