Preparation and reactivity of a square-planar PNP cobalt(ii)-hydrido complex: isolation of the first {Co-NO}-hydride.

The synthesis of a square-planar cobalt(ii) hydrido complex supported by a pyrrole-based PNP ligand has been reinvestigated and its reactivity with various small molecules examined. Preparation of the complex was accomplished by treatment of the corresponding chloride complex, [CoCl(PNP)] (PNP = anion of 2,5-bis((di-tert-butylphosphino)methyl)pyrrole), with di-iso-butylaluminum hydride (DIBAL). Reaction of [CoCl(PNP)] with other hydride sources such as NaEtBH and LiAlH resulted in mixtures of the desired Co(ii) hydride along with the reduced Co(i) species, [Co(N)(PNP)], as the primary product.

Low cytotoxicity of anisotropic gold nanoparticles coated with lysine on peripheral blood mononuclear cells "in vitro".

The aim of this study was to evaluate the cytotoxic effects of anisotropic (non spherical morphologies) gold nanoparticles coated with the amino acid Lysine (Lys) on peripheral blood mononuclear cells (PBMC) "in vitro". Gold (Au) nanoparticles tested in this study were synthesized by a seed-mediated growth using Lys as a structure and shape directing agent. Cytotoxic effects were evaluated by cell viability (resazurin assay), reactive oxygen species (ROS) induction (2',7'-dichlorofluorescein diacetate assay), DNA damage (comet assay) and apoptosis/necrosis (AnnexinV/propidium iodide assay) after PBMC were exposed to increasing concentrations (10, 25, 50, 100, and 250μM) of AuNPs coated with Lys (AuNPs-Lys) at different exposure times (3, 6, 12, and 24h).

Synthesis and characterisation of ruthenium-nitrosyl complexes in oxygen-rich ligand environments.

A series of new {Ru-NO} complexes containing Kläui's tripodal oxygen ligand, [CpCo{P(O)(OMe)}] (L), and substituted catecholates have been prepared by chloride exchange with [Ru(L)(NO)Cl]. The [Ru(L)(NO)(cat)] complexes (cat = dianion of catechol, 3,5-di-tert-butylcatechol, tetrabromocatechol, or 2,3-dihydroxynaphthalene) demonstrate spectroscopic features and redox properties consistent with the electronic character of the catecholate ligands. Several of the compounds display reversible oxidation events by cyclic voltammetry arising from the redox non-innocence of the catecholate ligands.

Biomonitoring of persistent organic pollutants (POPs) in child populations living near contaminated sites in Mexico.

The aim of this study was to conduct a POP biomonitoring programme for children in high-risk areas. We evaluated 247 serum samples from children between the ages of 6 and 12years old from two zones in Mexico: (1) indigenous zones, which included Cuatlamayan (CUA), Tocoy (TOC), and Santa Maria Picula (SAM); and (2) industrial zones, which included Tercera Chica (TC), Industrial San Luis (IND) and Rincon de San Jose (SJR); Mundo Nuevo (MN); and Alpuyeca (ALP). Our results showed that α-endosulfan was similar to CUA, TOC, SAM, TC and MN (178.

Synthesis, characterization, and binding affinity of hydrosulfide complexes of synthetic iron(II) porphyrinates.

The binding and reactivity of the hydrosulfide ion (HS) to iron(II) porphyrinates has been examined for several synthetic meso-tetraphenylporphine (TPP) derivatives. In all cases, HS coordinates to the iron centers in a 1:1 stoichiometry with formation constants (K) that reflect the electronic characteristics of the porphyrinate ligands. In the case of the FTPP ligand (FTPP=dianion of 5,10,15,20-tetrakis(2,6-difluorophenyl)porphine), an intermediate complex proposed as the hydrosulfide bridged dimer, (BuN)[Fe(μ-SH)(FTPP)], was identified by NMR spectroscopy en route to formation of (BuN)[Fe(SH)(FTPP)].

SERS-active Au/SiO2 clouds in powder for rapid ex vivo breast adenocarcinoma diagnosis.

In the present work, we report a dry-based application technique of Au/SiO2 clouds in powder for rapid ex vivo adenocarcinoma diagnosis through surface-enhanced Raman scattering (SERS); using low laser power and an integration time of one second. Several characteristic Raman peaks frequently used for the diagnosis of breast adenocarcinoma in the range of the amide III are successfully enhanced by breading the tissue with Au/SiO2 powder. The SERS activity of these Au/SiO2 powders is attributed to their rapid rehydration upon contact with the wet tissues, which promotes the formation of gold nanoparticle aggregates.

Bone Formation is Affected by Matrix Advanced Glycation End Products (AGEs) In Vivo.

Advanced glycation end products (AGEs) accumulate in bone extracellular matrix as people age. Although previous evidence shows that the accumulation of AGEs in bone matrix may impose significant effects on bone cells, the effect of matrix AGEs on bone formation in vivo is still poorly understood. To address this issue, this study used a unique rat model with autograft implant to investigate the in vivo response of bone formation to matrix AGEs.

High-resolution analytical imaging and electron holography of magnetite particles in amyloid cores of Alzheimer's disease.

Abnormal accumulation of brain metals is a key feature of Alzheimer's disease (AD). Formation of amyloid-β plaque cores (APC) is related to interactions with biometals, especially Fe, Cu and Zn, but their particular structural associations and roles remain unclear. Using an integrative set of advanced transmission electron microscopy (TEM) techniques, including spherical aberration-corrected scanning transmission electron microscopy (Cs-STEM), nano-beam electron diffraction, electron holography and analytical spectroscopy techniques (EDX and EELS), we demonstrate that Fe in APC is present as iron oxide (Fe3O4) magnetite nanoparticles.

Gallium(III) Tetraphenylporphyrinates Containing Hydrosulfide and Thiolate Ligands: Structural Models for Sulfur-Bound Iron(III) Hemes.

Gallium(III) tetraphenylporphyrinates (TPP) containing anionic sulfur ligands have been prepared and characterized in the solid state and solution. The complexes serve as structural models for iron(III) heme sites containing sulfur coordination that otherwise prove challenging to synthesize due to the propensity for reduction to iron(II). The compounds prepared include the first well-characterized example of a trivalent metalloporphyrinate containing a terminal hydrosulfide ligand, [Ga(SH)(TPP)], as well as [Ga(SEt)(TPP)], [Ga(SPh)(TPP)], and [Ga(SSi(i)Pr3)(TPP)].

NBu4SH provides a convenient source of HS(-) soluble in organic solution for H2S and anion-binding research.

Hydrogen sulfide (H2S) has gained significant interest within the scientific community due to its expanding roles in different (patho)physiological processes. Despite this importance, the chemical mechanisms by which H2S exerts its action remain under-scrutinized. Biomimetic investigations in organic solution offer the potential to clarify these mechanisms and to delineate the differential reactivity between H2S and HS(-).

Homoleptic transition metal complexes of the 7-azaindolide ligand featuring κ(1)-N1 coordination.

Homoleptic complexes of the anion of 7-azaindole (AzaIn) were synthesized and characterized for a series of 3d transition metals. For Mn(II), Fe(II), and Co(II), complexes of formula Na2[M(AzaIn)4]·2L (L = tetrahydrofuran (THF), 2-MeTHF, toluene, or benzene) were isolated by treatment of the corresponding metal chloride salts with 7-azaindole in the presence of sodium hexamethyldisilazide. The complexes adopt tetrahedral geometries with exclusive coordination to the transition metal ion through the pyrrolic N1 nitrogen atoms of the AzaIn ligands.

Analysis of cytotoxic effects of silver nanoclusters on human peripheral blood mononuclear cells 'in vitro'.

The antimicrobial properties of silver nanoparticles (AgNPs) have made these particles one of the most used nanomaterials in consumer products. Therefore, an understanding of the interactions (unwanted toxicity) between nanoparticles and human cells is of significant interest. The aim of this study was to assess the in vitro cytotoxicity effects of silver nanoclusters (AgNC, < 2 nm diameter) on peripheral blood mononuclear cells (PBMC).

Age-Related Effects of Advanced Glycation End Products (Ages) in Bone Matrix on Osteoclastic Resorption.

Advanced glycation end products (AGEs) accumulate in bone extracellular matrix as people age. Previous studies have shown controversial results regarding the role of in situ AGEs accumulation in osteoclastic resorption. To address this issue, this study cultured human osteoclast cells directly on human cadaveric bone slices from different age groups (young and elderly) to warrant its relevance to in vivo conditions.

Refined Frequency Doubling Perimetry Analysis Reaffirms Central Nervous System Control of Chronic Glaucomatous Neurodegeneration.

Purpose: Refined analysis of frequency doubling perimetric data was performed to assess binocular visual field conservation in patients with comparable degrees of bilateral glaucomatous damage, to determine whether unilateral visual field loss is random, anatomically symmetric, or non-random in relation to the fellow eye.

Methods: Case control study of 41 consecutive patients with bilaterally mild to severe glaucoma; each right eye visual field locus was paired with randomly-selected co-isopteric left eye loci, performing 690,000 (10,000 complete sets of 69 loci) such iterations per subject. The potential role of anatomic symmetry in bilateral visual field conservation was also assessed by pairing mirror-image loci of the right- and left-eye fields.

Synthesis, characterization, and atropisomerism of iron complexes containing the tetrakis(2-chloro-6-fluorophenyl)porphyrinate ligand.

Iron complexes of the meso-(tetraaryl)porphyrin, 5,10,15,20-tetrakis(2-chloro-6-fluorophenyl)porphine (H2ClFTPP) are reported. This unique ligand affords the opportunity to study atropisomerism in a porphyrin system containing similar substituents in the 2 and 6 positions of the meso-aryl rings. The atropisomerism displayed by the iron porphyrinates is observed to be a function of both the oxidation state of the metal and the nature of the axial ligand.

Validation of the Inventory of Callous-Unemotional Traits Among a Portuguese Sample of Detained Juvenile Offenders.

The main aim of the present study was to examine the psychometric properties of the Inventory of Callous-Unemotional Traits (ICU) among a sample of incarcerated male Portuguese juvenile offenders (N = 221). Based on this sample, the Portuguese version of the ICU demonstrated promising psychometric properties, namely, in terms of factor structure, internal consistency, convergent validity, discriminant validity, and concurrent validity that generally justifies its use among this population. Statistically significant associations were found with conduct disorder, age of criminal onset, crime seriousness, physical violence use in committing crimes, alcohol use, cannabis use, and cocaine/heroin use.

Characterization of conductive nanobiomaterials derived from viral assemblies by low-voltage STEM imaging and Raman scattering.

New technologies require the development of novel nanomaterials that need to be fully characterized to achieve their potential. High-resolution low-voltage scanning transmission electron microscopy (STEM) has proven to be a very powerful technique in nanotechnology, but its use for the characterization of nanobiomaterials has been limited. Rotavirus VP6 self-assembles into nanotubular assemblies that possess an intrinsic affinity for Au ions.

Studies of iron(III) porphyrinates containing silanethiolate ligands.

The chemistry of several iron(III) porphyrinates containing silanethiolate ligands is described. The complexes are prepared by protonolysis reactions of silanethiols with the iron(III) precursors, [Fe(OMe)(TPP)] and [Fe(OH)(H2O)(TMP)] (TPP = dianion of meso-tetraphenylporphine; TMP = dianion of meso-tetramesitylporphine). Each of the compounds has been fully characterized in solution and the solid state.

Advanced microscopy of star-shaped gold nanoparticles and their adsorption-uptake by macrophages.

Metallic nanoparticles have diverse applications in biomedicine, as diagnostics, image contrast agents, nanosensors and drug delivery systems. Anisotropic metallic nanoparticles possess potential applications in cell imaging and therapy + diagnostics (theranostics), but controlled synthesis and growth of these anisotropic or branched nanostructures has been challenging and usually require use of high concentrations of surfactants. Star-shaped gold nanoparticles were synthesized in high yield through a seed mediated route using HEPES as a precise shape-directing capping agent.

Artery buckling: new phenotypes, models, and applications.

Arteries are under significant mechanical loads from blood pressure, flow, tissue tethering, and body movement. It is critical that arteries remain patent and stable under these loads. This review summarizes the common forms of buckling that occur in blood vessels including cross-sectional collapse, longitudinal twist buckling, and bent buckling.

Nickel(II) complexes containing a pyrrole-diphosphine pincer ligand.

A new pincer ligand, (P(2)(Ph)Pyr)(-), based on the anion of 2,5-bis[(diphenylphosphino)methyl]pyrrole has been prepared in four steps from pyrrole. The ligand undergoes oxidation to diphosphine oxide under ambient conditions and was therefore isolated as its borane adduct, H(P(2)(Ph)Pyr)·2BH(3) (2). Delivery of the ligand to nickel(II) was accomplished by the direct reaction of NiCl(2) with 2 in the presence of Et(2)NH to afford [NiCl(P(2)(Ph)Pyr)].

Survey of Computational Algorithms for MicroRNA Target Prediction.

MicroRNAs (miRNAs) are 19 to 25 nucleotides non-coding RNAs known to possess important post-transcriptional regulatory functions. Identifying targeting genes that miRNAs regulate are important for understanding their specific biological functions. Usually, miRNAs down-regulate target genes through binding to the complementary sites in the 3' untranslated region (UTR) of the targets.