(Methyldiphenyl­phospho­ranylidene)­ammonium chloride

The title compound, C13H15NP+·Cl−, was obtained by hydrolysis of the N-trimethysilyl derivative of methydiphenyl­imino­phosphine. The dihedral angle between the phenyl rings in the cation is 61.5 (3)°. In the crystal structure, inter­molecular N—H⋯Cl hydrogen bonds links the two components, forming a centrosymmetric 2 + 2 aggregate

Aqua­[1,8-bis­(pyridin-2-yl)-3,6-dithia­octane-κ4 N,S,S′,N′]copper(II) dinitrate acetonitrile monosolvate

In the title compound, [Cu(C16H20N2S2)(H2O)](NO3)2·CH3CN, the CuII atom displays a distorted square-pyramidal coordination, in which a water mol­ecule occupies the apical position and the basal plane is formed by two N atoms and two S atoms of a 1,8-bis­(pyridin-2-yl)-3,6-dithia­octane ligand. The crystal packing is stabilized by O—H⋯O and C—H⋯O hydrogen bonds

Pooled analysis of WHO Surgical Safety Checklist use and mortality after emergency laparotomy

Background The World Health Organization (WHO) Surgical Safety Checklist has fostered safe practice for 10 years, yet its place in emergency surgery has not been assessed on a global scale. The aim of this study was to evaluate reported checklist use in emergency settings and examine the relationship with perioperative mortality in patients who had emergency laparotomy. Methods In two multinational cohort studies, adults undergoing emergency laparotomy were compared with those having elective gastrointestinal surgery. Relationships between reported checklist use and mortality were determined using multivariable logistic regression and bootstrapped simulation. Results Of 12 296 patients included from 76 countries, 4843 underwent emergency laparotomy. After adjusting for patient and disease factors, checklist use before emergency laparotomy was more common in countries with a high Human Development Index (HDI) (2455 of 2741, 89.6 per cent) compared with that in countries with a middle (753 of 1242, 60.6 per cent; odds ratio (OR) 0.17, 95 per cent c.i. 0.14 to 0.21, P <0001) or low (363 of 860, 422 per cent; OR 008, 007 to 010, P <0.001) HDI. Checklist use was less common in elective surgery than for emergency laparotomy in high-HDI countries (risk difference -94 (95 per cent c.i. -11.9 to -6.9) per cent; P <0001), but the relationship was reversed in low-HDI countries (+121 (+7.0 to +173) per cent; P <0001). In multivariable models, checklist use was associated with a lower 30-day perioperative mortality (OR 0.60, 0.50 to 073; P <0.001). The greatest absolute benefit was seen for emergency surgery in low- and middle-HDI countries. Conclusion Checklist use in emergency laparotomy was associated with a significantly lower perioperative mortality rate. Checklist use in low-HDI countries was half that in high-HDI countries.Peer reviewe

Propuesta de implementación del mantenimiento autónomo en el área de inyección de la empresa Ave Colombiana S.A.S

En este proyecto se presenta una propuesta para la elaboración de una guía metodológica de la implementación de Mantenimiento Autónomo como estrategia de mantenimiento con el fin de reducir las fallas en las máquinas de esta manera tener mayor y disponibilidad de los equipos. Se basó en la explicación de uno de los pilar que hace parte de la estrategia TPM (Mantenimiento Autónomo) el cual inicia con las etapas de: limpieza inicial en donde se eliminan todo tipo de suciedad, escapes, polvo y ajustes menores, luego se harán acciones correctivas en la fuente evitando que el equipo se ensucie nuevamente, facilitar su acceso, inspección y limpieza inicial; reducir el tiempo empleado en la limpieza profunda, Inspección general el entrenamiento para la inspección haciendo uso de manuales, eliminación de pequeñas averías y mayor conocimiento del equipo a través de la verificación, para posteriormente continuar con la técnica japonesa de 5s clasificación (Seiri), orden (Seiton), limpieza (Seiso), estandarización (Seiketsu) y disciplina (Shitsuke). Al1 Título de la Investigación 2 Problema de investigación 3 objetivos de la investigación 4 Justificación y delimitación 5 Marco referencia 6 Marco Metodológico 7 Impactos alcanzados y esperados 8 Análisis financiero 9 Conclusiones y recomendaciones 10 BibliografíaInvestigación CuantitativaEspecializaciónEspecialista en Gerencia de MantenimientoEspecialización en Gerencia de Mantenimient

Au-TiO2 Synthesized by a Microwave- and Sonochemistry-Assisted Sol-Gel Method: Characterization and Application as Photocatalyst

Titanium dioxide (TiO2) is a widely used and well studied photocatalyst synthesized using different methodologies, including sol-gel, which allows one to modify the material in a one-pot step. By using a microwave- and sonochemistry-assisted sol-gel method, x wt.% Au-TiO2 photocatalysts were successfully synthesized. Physicochemical characterization of the photocatalysts shows an average crystallite size of 10.5 nm and an even morphological distribution of spherical particles with the sonochemistry synthesis method. For the microwave method an average value of crystallite size of 8.3 nm was found and it presents an increase with the amount of Au load. The cyclic voltammetric response and Mott-Schottky analysis are consistent with a semiconductor material containing metallic particles and for a heterophase junction of anatase and brookite with oxygen vacancies, respectively. The photocatalytic activity was assessed by paracetamol degradation in an aqueous solution as model. The sonochemistry-synthesized photocatalysts display the most promising results as they have a better paracetamol removal and the amount of gold in the catalyst (0.7 wt.%) was found to be optimal for this process

4-Ferrocenylpyridine- and 4-Ferrocenyl-3-ferrocenylmethyl-3,4-dihydropyridine-3,5-dicarbonitriles: Multi-Component Synthesis, Structures and Electrochemistry

The reactions of 2-cyano-3-ferrocenylacrylonitrile (1) with malononitrile (2) in a MeOH/H2O or 2-PrOH/H2O medium in the presence of Na2CO3 afforded 6-alkoxy-2-amino-4-ferrocenylpyridine-3,5-dicarbonitriles 3a,b (multi-component condensation) and 6-alkoxy-2-amino-4-ferrocenyl-3-ferrocenylmethyl-3,4-dihydropyridine-3,5-dicarbonitriles 4a,b (multi-component cyclodimerization). Analogous reactions of 1 with 2 in an MeOH/H2O medium in the presence of NaOH, piperidine, or morpholine gave compounds 3a, 4a and 2-amino-4-ferrocenyl-6-hydroxy-, 6-piperidino- and 6-morpholinopyridine-3,5-dicarbonitriles 3c–e, respectively. The structures of the compounds 3b, 4a and 4b were established by the spectroscopic data and X-ray diffraction analysis. The electrochemical behaviour of compounds 3b, 3d and 4b was investigated by means of cyclic voltammetry

Coexistence of intramolecular ligand-mediated and through hydrogen-bond magnetic interactions in a chain of dicopper(II) units

The reaction of 2,8-dimethyl-5,11-bis(pyridin-2-ylmethyl)-1,4,5,6,7,10,11,12-octahydroimidazo[4,5-h]imidazo[4,5-c][1,6]-diazecine (dimp) with copper(II) nitrate in water produces the compound [Cu(2)(dimp)(H(2)O)(2)(NO(3))(2)](NO(3))(2). The single-crystal X-ray structure shows the formation of hydrogen-bonded chains in the lattice that are formed by dicopper(II) units doubly connected by nitrate/water bridges. Within the one-dimensional chains, the Cu ions are separated by either intramolecular or intermolecular distances of 7.309(2) Å or 6.255(2) Å, respectively. The magnetic susceptibility data revealing weak antiferromagnetic exchange interactions between the copper(II) ions were interpreted by considering two possible models, namely, an isolated dinuclear and a 1-D chain picture. The latter leads to an alternation J(1) = -11.6 and J(2) = -3.0 cm(-1) along the chain. In order to clarify the relative strengths of the exchange couplings through hydrogen bonds and via the bridging dimp ligand, solution EPR studies and quantum chemical calculations were carried out. EPR studies unambiguously conclude on the existence of an exchange interaction J(a) mediated by the dinucleating dimp ligand, while the through-H coupling J(b) is physically absent in solution. On the basis of dinuclear units extracted from the X-ray data, J(a) was estimated around -5.0 cm(-1) from DFT-based calculations (M06 functional), whereas J(b) is negligible. In contrast, wave function configuration interaction calculations (DDCI) support a description where both inter- and intramolecular pathways coexist with a preeminent role of H bonds with J(a) = -2.8 and J(b) = -10.4 cm(-1). Not only are these values very consistent with the extracted set of parameters (J(1), J(2) = -11.6, -3.0 cm(-1)) but the possibility to generate leading exchange coupling through weak bonds is evidenced by means of wave function-based calculations

Indirect quantification of glyphosate by SERS Using an incubation process with hemin as the reporter molecule: a contribution to signal amplification mechanism

"The indirect determination of the most used herbicide worldwide, glyphosate, was achieved by the SERS technique using hemin chloride as the reporter molecule. An incubation process between hemin and glyphosate solutions was required to obtain a reproducible Raman signal on SERS substrates consisting of silicon decorated with Ag nanoparticles (Si-AgNPs). At 780 nm of excitation wavelength, SERS spectra from hemin solutions do not show extra bands in the presence of glyphosate. However, the hemin bands increase in intensity as a function of glyphosate concentration. This allows the quantification of the herbicide using as marker band the signal associated with the ring breathing mode of pyridine at 745 cm−1. The linear range was from 1 × 10−10 to 1 × 10−5 M and the limit of detection (LOD) was 9.59 × 10−12 M. This methodology was successfully applied to the quantification of the herbicide in honey. From Raman experiments with and without silver nanoparticles, it was possible to state that the hemin is the species responsible for the absorption in the absence or the presence of the herbicide via vinyl groups. Likewise, when the glyphosate concentration increases, a subtle increase occurs in the planar orientation of the vinyl group at position 2 in the porphyrin ring of hemin over the silver surface, favoring the reduction of the molecule. The total Raman signal of the hemin-glyphosate incubated solutions includes a maximized electromagnetic contribution by the use of the appropriate laser excitation, and chemical contributions related to charge transfer between silver and hemin, and from resonance properties of Raman scattering of hemin. Incubation of the reporter molecule with the analyte before the conjugation with the SERS substrate has not been explored before and could be extrapolated to other reporter-analyte systems that depend on a binding equilibrium process"

Intramolecular Conversions of (Aminoferrocenylpenta-1,4dienyl)-ferrocenylcarbenes: Synthesis of Diferrocenylmono-, bi-, tricycles and Amino(diferrocenyl)hexa-1,3,5-trienes

molecule

ELECTROCHEMICAL STUDY OF CIS-DIFERROCENYLETHENE DERIVATES

Ferrocene derivatives have been used in the synthesis of polymeric materials with thermal resistance and nonlinear optical properties, and in the field of supramolecular electrochemistry as redox switching receptors. For these reasons, during the past few years the electrochemical studies on ferrocenyl derivatives have been growing up. In order to characterize molecules with potential uses in the synthesis of polymeric materials and to understand its electrochemical functioning, this paper presents electrochemical studies on these chemicals: 1) cis-diferrocenylethenes derivates (Isopropyl cis-2,3-Diferrocenylacrylate; 2) cis-2,3-Diferrocenylacrylic Acid; 3) cis-2,3- Diferrocenylacrylohydrazide; 4) cis-2,3-Diferrocenylacrylic Acid Piperidide; 5) cis-3,4- Diferrocenyl-2-methylbut-3-en-ol, and 6) cis-1,1-Diphehyl-2,3-Diferrocenylprop-2-en-1-ol. All of the chemicals presented two oxidation processes (I-II), which were thought to be caused by the oxidation of the ferrocene groups, E1/2(I), E1/2(II), ¿E1/2 (II-I). The comproportionation constant Kcom was calculated. According to this value, it can be proposed that the molecules containing a carbonyl group (1-4) present larger electronic communication compared to molecules with a hydroxy group (5-6). Uv-vis espectra of all compounds in butironitrile solution were obtained. A correlation between Kcom and ¿ max was also observed