Electron Transport through Linear-, Broken-, and Cross-Conjugated Polycyclic Compounds.

Quantum interference (QI) effects offer unique opportunities to modulate charge transport through single molecules. In recent years, several transmission selection rules have been developed to determine constructive and destructive QIs in an intuitive and simple manner, although some of these rules fail for cross-conjugated systems. In this work, we evaluate the performance of distinct transmission rules on a broad series of anthracene and fluorene derivatives with distinctive structural features including linear-, broken-, and cross-conjugation, heteroatoms, and five-membered rings as such species affords a predictive challenge for the qualitative selection rules for QI effects.

Similarities and Differences in Benzene Reduction with Ca, Sr, Yb and Sm: Strong Evidence for Tetra-Anionic Benzene.

Inverse sandwich complexes of Yb and Sm stabilized by a bulky β-diketiminate (BDI) ligand have been prepared: (BDI)Ln(η,η-CH)Ln(BDI); Ln=lanthanide. Coordinated benzene ligands can be neutral, di-anionic or, often controversially discussed, even tetra-anionic. The formal charge on benzene is correlated to assignment of the metal oxidation state which generally poses a problem.

T-Shaped Palladium and Platinum {MNO} Nitrosyl Complexes.

The synthesis and characterization of a homologous series of T-shaped {MNO} nitrosyl complexes of the form [M(PR)(NO)] (M = Pd, Pt; R = Bu, Ad) are reported. These diamagnetic nitrosyls are obtained from monovalent or zerovalent precursors by treatment with NO and NO, respectively, and are notable for distinctly bent M-NO angles of ∼123° in the solid state. Adoption of this coordination mode in solution is also supported by the analysis of isotopically enriched samples by N NMR spectroscopy.

Modulation of Metal Carbonyl Stretching Frequencies in the Second Coordination Sphere through the Internal Stark Effect.

Spectroscopic and computational examination of a homologous series of rhodium(I) pybox carbonyl complexes has revealed a correlation between the conformation of the flanking aryl-substituted oxazoline donors and the carbonyl stretching frequency. This relationship is also observed experimentally for octahedral rhodium(III) and ruthenium(II) variants and cannot be explained through the classical, Dewar-Chatt-Duncanson, interpretation of metal-carbonyl bonding. Instead, these findings are reconciled by local changes in the magnitude of the electric field that is projected along the metal-carbonyl vector: the internal Stark effect.

Histopathological growth patterns of liver metastasis: updated consensus guidelines for pattern scoring, perspectives and recent mechanistic insights.

The first consensus guidelines for scoring the histopathological growth patterns (HGPs) of liver metastases were established in 2017. Since then, numerous studies have applied these guidelines, have further substantiated the potential clinical value of the HGPs in patients with liver metastases from various tumour types and are starting to shed light on the biology of the distinct HGPs. In the present guidelines, we give an overview of these studies, discuss novel strategies for predicting the HGPs of liver metastases, such as deep-learning algorithms for whole-slide histopathology images and medical imaging, and highlight liver metastasis animal models that exhibit features of the different HGPs.

Myopericytoma of the Parotid and Molecular Profiling: Report of a Rare Case and Review of the Literature.

Myopericytomas are uncommon tumors defined by their round to spindle shaped cells often arranged in a concentric pattern of perivascular growth. They are typically well-circumscribed, nodular, slow-growing lesions that occur in the soft tissue of the extremities. Here, we present a 30-year-old female with a 2.

Prediction of the bioavailability of potentially toxic elements in freshwaters. Comparison between speciation models and passive samplers.

The aim of this work is to predict the bioavailability of the Potentially Toxic Elements (PTEs) Cd, Pb, Hg, Ni, Cu, Zn, As, Cr and Se in 6 sites within the Ebro River basin. In situ Diffusive gradient in thin-films (DGTs) and classical sampling have been used and compared. The potentially bioavailable fractions of each PTE was estimated by modelling their chemical speciation using three programs (WHAM 7.

Human health risks of formaldehyde indoor levels: An issue of concern.

Formaldehyde is a carcinogenic substance for humans. Exposure to formaldehyde may also cause eye and respiratory tract irritation, as well as skin sensitization. The main indoor sources of formaldehyde are wood-pressed products, insulation materials, paints, varnishes, household cleaning products and cigarettes, among others.

Metal bioavailability in freshwater sediment samples and their influence on ecological status of river basins.

The general aim of this work has been to check the ecological impact of metals on the Ebro river basin. In order to evaluate this, metal behavior considering water, sediment as well as metal bioaccumulation in fish has been studied. Total concentrations of metals, as well as the potentially bioavailable fraction of metals in sediment has also been analyzed by the application of the sequential extraction method (BCR method).

Ecotoxicity of sediments in rivers: Invertebrate community, toxicity bioassays and the toxic unit approach as complementary assessment tools.

The determination of the real toxicity of sediments in aquatic ecosystems is challenging and necessary for an appropriate risk assessment. Different approaches have been developed and applied over the last several decades. Currently, the joint implementation of chemical, ecological and toxicological tools is recommended for an appropriate and successful toxicity risk assessment.

Assessment of sediment ecotoxicological status as a complementary tool for the evaluation of surface water quality: the Ebro river basin case study.

According to the European Water Framework Directive (WFD), assessment of surface water status is based on ecological and chemical status that is not always in coherence. In these situations, ecotoxicity tests could help to obtain a better characterization of the ecosystems. The general aim of this work is to design a methodology to study the ecotoxicological status of freshwater systems.

Integrated study of metal behavior in Mediterranean stream ecosystems: a case-study.

The objective of the present work was to assess the ecosystem status of Francolí river (Catalonia, Spain), a Mediterranean stream basin with contrasting human influences. An integrated approach was designed by combining physicochemical, biological and ecotoxicological analyses. The content of metals (As, Cd, Cr, Co, Cu, Hg, Ni, Pb, and Zn) was analyzed in samples of water, benthic sediments and aquatic macroinvertebrates.

In vitro tests to assess toxic effects of airborne PM(10) samples. Correlation with metals and chlorinated dioxins and furans.

Inhalation is an important exposure pathway to airborne pollutants such as heavy metals, polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and particulate matter. Chronic exposure to those chemicals, which form part of complex environmental mixtures, may mean important human health risks. In the present study, the suitability of different in vitro tests to evaluate the toxic effects of air PM(10) pollutants is investigated.

Novel approach for assessing heavy metal pollution and ecotoxicological status of rivers by means of passive sampling methods.

In order to study the pollution of fluvial ecosystems, it is necessary to analyze not only the levels of chemical contaminants in water, but also those accumulated in the sediment matrix, as well as to assess its ecotoxicological status. Eleven Catalan (Spain) river sections (one sampling point per river) located near urban and industrial areas were sampled during winter of 2009. Water pollutants were collected by using passive samplers as Diffusive Gradient in Thin-Films (DGTs) and Semi-Permeable Membrane Devices (SPMDs).

[Surgical treatment of a pheocromocytoma bilateral in a 5 year old patient with the von Hippel-Lindau disease].

Introduction: The disease of Von Hippel Lindau (VHL) is hereditary and causes a predisposition to the development of tumours. Organs such as the cerebellum, the pancreas, the kidney, the suprarenal glands and the retina are more usually affected by this disease.

Clinical Case: We present the case of a 5-year-old patient who suffers from asiymptomatic high blood pressure.

Snake instability of a spatiotemporal bright soliton stripe.

We study experimentally the snake instability of the bright soliton stripe of the (2+1)-dimensional hyperbolic nonlinear Schrödinger equation. The instability is observed, through spectral measurements, on spatially extended femtosecond pulses propagating in a normally dispersive self-defocusing semiconductor planar waveguide.