(μ-2,2′-Bipyrimidine-κ4 N 1,N 1′:N 3,N 3′)bis­[triaqua­(sulfato-κO)manganese(II)]

The title complex, [Mn2(SO4)2(C8H6N4)(H2O)6], is the second monoclinic polymorph [De Munno et al. (1995 ▶). Inorg. Chem. 34, 408–411; Hong et al. (1996 ▶). Polyhedron, 15, 447–452]. The asymmetric unit contains two crystallographically independent half-mol­ecules of the binuclear MnII complex; an inversion centre is located at the centroid of each complex. The two MnII atoms in each complex mol­ecules are bridged by a bis-chelating 2,2′-bipyrimidine (bpym) ligand and each MnII atom is six-coordinated in a considerably distorted octa­hedral environment defined by two N atoms of the bridging bpym ligand and four O atoms from one sulfato anionic ligand and three water mol­ecules. In the crystal, the complex mol­ecules are linked by O—H⋯O hydrogen bonds between the water and sulfato ligands, forming a three-dimensional network

Synthesis of a rod-based porous coordination polymer from a nucleotide as a sequential chiral inductor

We report the two-step synthesis of a novel chiral rod-based porous coordination polymer (PCP). The chemical approach consists on the use of a previously prepared bis(ethylendiamine) copper monomer of formula [Cu(en)]2(NO3)2 [where en = ethylendiamine] reacting with the cytidine 5'-monophosphate (CMP) nucleotide. The bis(ethylendiamine) copper compound -stabilized by the axial coordination of nitrate counter-anions- reacts in the presence of sodium salt of CMP to yield right-handed copper(II) chains of P helicity with formula [Cu2(en)2(CMP)2] . 5H2O (1). The axial coordination of the CMP2- ligands through the N3 and O2 sites (free nitrogen and carbonyl groups) of the cytosine nucleobase and oxygen atoms of phosphate moieties, ensure the stabilization of the neutral chiral polymer. The supramolecular organization involves strong hydrogen bonding interactions to build supramolecular chains of the same helicity. The resulting PCP constitutes one of the few examples of CMP compounds exhibiting a such coordination involving both nucleobase and phosphate moieties, where a highly stable metal complex is used as precursor for the rational construction of rod-based hydrogen metal-organic frameworks (HMOFs). Furthermore, it is underlined the intrinsic capability of biomolecules to act as chiral transfer systems

Aprehender álgebra utilizando contextos significativos

En la enseñanza tradicional no se tienen suficientemente en cuenta las dificultades en la comprensión, por parte del alumno, del tratamiento algebraico para la solución de situaciones problemáticas; logrando, en el mejor de los casos, que el alumno se convierta en un mero repetidor de procedimientos absolutamente rígidos, sin profundizar en el origen y significado de las distintas representaciones algebraicas y sus métodos de solución

Las emociones : factores imprescindibles en el aprendizaje de la matemática

Las emociones forman parte sustancialmente de la vida humana. Constantemente se experimentan emociones, pero raramente el ser humano reflexiona sobre qué son las emociones, por qué se experimentan, cómo influyen en el pensamiento, en el comportamiento y en el aprendizaje. Se sabe que las emociones desagradables (como ira, tensión, tristeza, entre otras) desvían la atención, interfiriendo en la concentración. En este trabajo, se realizaron encuestas a estudiantes para consultarles cómo el confinamiento provocado por la pandemia de Sars Covid-2 afectó social y educativamente sus vidas en el año 2020, y qué emociones y sentimientos experimentaron durante ese tiempo y cuáles de ellas han podido experimentar al regresar a la presencialidad. Además, se propone un diseño de estrategias didácticas que fomenten y permitan incorporar la Educación Emocional en las clases de Matemática II donde se generen nuevos espacios para el conocimiento y la expresión de las emociones.Fil: Berliansky, Ana Federica. Universidad Nacional de Cuyo. Facultad de Ciencias Económicas.Fil: De Munno, Cecilia Yasmín. Universidad Nacional de Cuyo. Facultad de Ciencias Económicas.Fil: Mancinelli, Carolina Cecilia. Universidad Nacional de Cuyo. Facultad de Ciencias Económicas

The azido ligand: a useful tool in designing chain compounds exhibiting alternating ferro- and antiferro-magnetic interactions

A one-pot reaction of NiII 1, CoII 2, FeII 3 and MnII 4 with 2,2A-bipyridine (bipy) and azide in water leads to [M(bipy)(N3)2]n chains where the metal ion is alternatively bridged by double end-on (EO) and end-to-end (EE) azido bridges; theoretical analysis of the variable-temperature magnetic susceptibility data of 1 and 4 reveals the occurrence of intrachain alternating ferro- (through EO) and antiferro-magnetic (through EE) interactions.Julve Olcina, Miguel, [email protected] ; Lloret Pastor, Francisco, [email protected] ; Clemente Juan, Juan Modesto, [email protected]

Enhancement of the Intermolecular Magnetic Exchange through Halogen···Halogen interactions in Bisadeninium Rhenium(IV) Salts

Two novel Re^IV salts of general formula [H₂ade]₂[Re^IVX₆]­X₂·4H₂O [H₂ade²⁺ = 9<i>H</i>-adenine-1,7-diium; X = Cl­(<b>1</b>) and Br­(<b>2</b>)] have been synthesized and magnetostructurally characterized. <b>1</b> and <b>2</b> are isostructural salts that crystallize in the orthorhombic system with space group <i>Fdd</i>2. Both compounds are made up of discrete mononuclear [Re^IVX₆]^2– and X^– anions and doubly protonated adenine cations. The six-coordinate rhenium­(IV) ion is bonded to six halide ligands [X = Cl (<b>1</b>) and Br (<b>2</b>)] in an octahedral geometry. Short intermolecular Re^IV–X···X–Re^IV interactions, as well as Re^IV–X···H–N­(H₂ade) and Re^IV–X···H–O_w hydrogen bonds, are present in the crystal lattice of <b>1</b> and <b>2</b>. Magnetic susceptibility measurements on polycrystalline samples of <b>1</b> and <b>2</b> in the temperature range 2.0–300 K show the occurrence of significant intermolecular antiferromagnetic interactions in both compounds, resulting in the observation of maxima in χ_M at ca. 6.0 (<b>1</b>) and 12.0 K (<b>2</b>). The larger spin delocalization from the Re^IV ion onto the peripheral bromide ligands when compared to the chloride ligands accounts for the enhancement of the magnetic exchange observed in <b>2</b>

A novel supramolecular assembly in an iron(III) compound exhibiting magnetic ordering at 70 K

Ethyl-substituted ammonium cation allows the preparation of an unprecedented oxo- and oxalato-bridged supramolecular three-dimensional network. The compound exhibits magnetic ordering with Tc = 70 K due to a weak spin canting.Julve Olcina, Miguel, [email protected] ; Lloret Pastor, Francisco, [email protected]

Self-assembly, binding ability and magnetic properties of dicopper(ii) pyrazolenophanes

A novel series of dinuclear copper(II) pyrazolenophanes of the formula [Cu-2(mu-4-Mepz)(2)(mu-ClO4)(ClO4)(bpm)(2)] (1), [Cu-2(mu-pz)(2)(mu-H2O)(ClO4)(4,7-Me(2)phen)(2)]ClO4 center dot H2O center dot CH3CN (2), [Cu-2(mu-pz)(2)(mu-H2O)(ClO4)(3/2)(H2O)(1/2)(phen)(2)](2)[Cu-2(mu-pz)(2)(mu-ClO4)(ClO4)(2)(phen)(2)]center dot 8H(2)O (3), and [Cu-2(mu-pz)(2)(CH3CN)(2)(3,4,7,8-Me(4)phen)(2)](ClO4)(2) (4) (Hpz = pyrazole, H-4-Mepz = 4-methylpyrazole, bpm = 2,2'-bipyrimidine, phen = 1,10-phenanthroline, 4,7-Me(2)phen = 4,7-dimethyl-1,10-phenanthroline, and 3,4,7,8-Me(4)phen = 3,4,7,8-tetramethyl-1,10-phenanthroline) have been synthesized and magneto-structurally investigated. The crystal structures of 1-4 contain bis(pyrazolate)(perchlorate)-(1 and 3), bis(pyrazolate)(aqua)-(2 and 3), or bis(pyrazolate)-bridged (4) dicopper(II) entities of the metallacyclophane-type with bpm (1), 4,7-Me(2)phen (2), phen (3), and 3,4,7,8-Me(4)phen (4) as blocking bidentate ligands. All of them exhibit a saddle conformation with an overall not planar but bent, six-membered Cu-(N-N')(2)-Cu metallacyclic core with relatively short intermetallic distances across the bis(pyrazolate)(perchlorate) [r = 3.3076(5) (1) and 3.382(1) angstrom (3)], bis(pyrazolate)(aqua) [r = 3.383(1) (2) and 3.357(1) angstrom (3)], and bis(pyrazolate) bridges [r = 3.098(1) angstrom (4)]. The analyses of the variable-temperature magnetic susceptibility of 1-4 reveal the occurrence of a moderately strong antiferromagnetic coupling across the bis(pyrazolate)(perchlorate) [-J = 228 (1) and 193 cm(-1) (3)], bis(pyrazolate)(aqua) [-J = 189 (2) and 221 cm(-1) (3)], and bis(pyrazolate) bridges [-J = 197 cm(-1) (4)] (the spin Hamiltonian being defined as H = -JS(1).S-2 with S-1 = S-2 = S-Cu = 1/2).A novel series of dinuclear copper(II) pyrazolenophanes of the formula [Cu2(μ-4-Mepz)2(μ-ClO4)(ClO4)(bpm)2] (1), [Cu2(μ-pz)2(μ-H2O)(ClO4)(4,7-Me2phen)2]ClO4·H2O·CH3CN (2), [Cu2(μ-pz)2(μ-H2O)(ClO4)3/2(H2O)1/2(phen)2]2[Cu2(μ-pz)2(μ-ClO4)(ClO4)2(phen)2]·8H2O183437449COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESsem informaçãoThis work was supported by the Ministerio Español de Economía y Competitividad (Project CTQ2013-44844P and Unidad de Excelencia MDM-2015-0538) and the Generalitat Valenciana (PROMETEOII/2014/070). We also acknowledge the financial support from Brazilian

Discriminant analysis on small cell lung cancer and non-small cell lung cancer by means of NSE and CYFRA-21.1

A correct diagnosis of small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC) is essential both for prognostic and therapeutic reasons. We used discriminant analysis as a method to optimize the discriminant power of serum tumour marker levels for differentiation between SCLC and NSCLC. A panel of serum markers, including neurone specific enolase (NSE), cytokeratin fragment antigen 21.1 (CYFRA-21.1), tissue polypeptide antigen (TPA) and carcinoembryonic antigen (CEA) was obtained in 50 consecutive NSCLC and 17 SCLC. Data were analysed by the BMDP statistical program after logarithmic transformation of marker levels. The variables selected were NSE and CYFRA-21.1. Considered together, they were able to give a 97% rate of correct classification. The formula generated (canonic variable, CV) was validated on a group of seven SCLC and 22 NSCLC patients. Only two errors occurred. We therefore conclude that the canonic variable tested, based on NSE and CYFRA-21.1, provides a good discrimination between the two types of lung cancer. The method is rapid, relatively inexpensive, and based on simple serum tests

Fatores estressantes da equipe de enfermagem atuantes em cti: Revisão sistemática / Stressing factors of the nursing team acting in intensive care centers

Objetivos: Explanar sobre os principais fatores estressantes para a equipe de enfermagem atuantes nos Centro de Terapia Intensiva (CTI). Metodologia: Os critérios de elegibilidade para o estudo foram estudos publicados nos últimos 10 anos (datados de 2010 a 2020), que continham as palavras-chave/descritores no título, abordando a temática em questão Resultados: A busca nas bases de dados resultou na identificação de 58 artigos, 50 foram excluídos, restando 8 artigos elegíveis para esse estudo. Conclusão: Observou-se com os resultados desta revisão que o trabalho no CTI favoreceu o surgimento de doenças psicossomáticas relevantes, adquiridas devido as condições e fatores em que a equipe de enfermagem está exposta. Demonstrando a necessidade de um olhar atento aos profissionais de saúde, em relação ao estado mental, afim atender às necessidades exclusivas da enfermagem, com foco na saúde mental em ambientes críticos de saúde como os centros de terapia intensiva