Coordination controlled electrodeposition and patterning of layers of palladium/copper nanoparticles on top of a self-assembled monolayer.

A scheme for the generation of bimetallic nanoparticles is presented which combines electrodeposition of one type of metal, coordinated to a self-assembled monolayer (SAM), with another metal deposited from the bulk electrolyte. In this way PdCu nanoparticles are generated by initial complexation of Pd to a SAM of 3-(4-(pyridine-4-yl)phenyl)propane-1-thiol (PyP3) on Au/mica and subsequent reduction in an acidic aqueous CuSO electrolyte. Cyclic voltammetry reveals that the onset of Cu deposition is triggered by Pd reduction.

Performance of local optimization in single-plane fluoroscopic analysis for total knee arthroplasty.

Fluoroscopy-derived joint kinematics plays an important role in the evaluation of knee prostheses. Fluoroscopic analysis requires estimation of the 3D prosthesis pose from its 2D silhouette in the fluoroscopic image, by optimizing a dissimilarity measure. Currently, extensive user-interaction is needed, which makes analysis labor-intensive and operator-dependent.

Photophysical Properties and Electronic Structure of Chlorin-Imides: Bridging the Gap between Chlorins and Bacteriochlorins.

Efficient light harvesting for molecular-based solar-conversion systems requires absorbers that span the photon-rich red and near-infrared (NIR) regions of the solar spectrum. Reported herein are the photophysical properties of a set of six chlorin-imides and nine synthetic chlorin analogues that extend the absorption deeper (624-714 nm) into these key spectral regions. These absorbers help bridge the gap between typical chlorins and bacteriochlorins.

Synthesis and characterisation of BODIPY radical anions.

The redox processes associated with BODIPY analogues are studied by electrochemical and spectroscopic methods revealing a characteristic profile for the persistent BODIPY radical and quenching of fluorescence upon reduction.

Electrodeposition of palladium onto a pyridine-terminated self-assembled monolayer.

The electrodeposition of Pd onto self-assembled monolayers (SAMs) of 3-(4-pyridine-4-ylphenyl)propane-1-thiol on Au(111) has been investigated by scanning tunneling microscopy. Two schemes are compared: One involves an established two-step procedure where Pd(2+) ions are first coordinated to the pyridine moieties and subsequently reduced in Pd(2+)-free electrolyte. The second deposition routine involves electroreduction in an electrolyte containing low concentration of Pd(2+) which merges both steps and, thus, significantly simplifies metal deposition onto pyridine-terminated SAMs.

A "push-pull" mechanism for heterolytic o-o bond cleavage in hydroperoxo manganese porphyrins.

A water-soluble manganese porphyrin, 5,10,15,20-tetrakis-(1,3-dimethylimidazolium-2-yl)porphyrinatomanganese(III) (Mn(III)TDMImP) is shown to react with H(2)O(2) to generate a relatively stable dioxomanganese(V) porphyrin complex (a compound I analog). Stopped-flow kinetic studies revealed Michaelis Menton-type saturation kinetics for H(2)O(2). The visible spectrum of a compound 0 type intermediate, assigned as Mn(III)(OH)(OOH)TDMImP, can be directly observed under saturating H(2)O(2) conditions (Soret band at 428 nm and Q bands at 545 and 578 nm).

De novo synthesis of long-wavelength absorbing chlorin-13,15-dicarboximides.

Chlorins bearing a six-membered imide ring spanning positions 13-15, commonly referred to as purpurinimides, exhibit long-wavelength absorption yet have heretofore only been available via semisynthesis from naturally occurring chlorophylls. A concise route to synthetic chlorins, which bear a geminal dimethyl group in the pyrroline ring, has been extended to provide access to chlorin-13,15-dicarboximides. The new route entails (i) synthesis of a 13-bromochlorin, (ii) palladium-catalyzed carbamoylation at the 13-position, (iii) regioselective 15-bromination under acidic conditions, and (iv) one-flask palladium-mediated carbonylation and ring closure to form the imide.

Regioselective bromination tactics in the de novo synthesis of chlorophyll b analogues.

The ability to introduce substituents at designated sites about the perimeter of the chlorin or 13(1)-oxophorbine macrocycle is essential for fundamental studies related to chlorophylls. A chlorin is a dihydroporphyrin, whereas a 13(1)-oxophorbine is a chlorin containing an annulated oxopentano ring spanning positions 13 and 15. 13(1)-Oxophorbines bearing auxochromes at the 7-position of the macrocycle are valuable targets given their resemblance to chlorophyll a or b, which contains the 13(1)-oxophorbine skeleton and bears a 7-methyl or 7-formyl group, respectively.

Self-assembly of a pyridine-terminated thiol monolayer on Au(111).

Self-assembled monolayers (SAMs) of 3-(4-pyridine-4-yl-phenyl)-propane-1-thiol (PyP3) on Au(111)/mica have been studied by scanning tunneling microscopy (STM), polarization-modulated infrared reflection absorption spectroscopy (PM-IRRAS), high-resolution X-ray photoemission spectroscopy (HRXPS), and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy. The quality of the SAM is found to be strongly dependent on the solvent. Substantial gold corrosion is observed if pure ethanol is used.

Work-related sickness absences and mandatory occupational health surveillance.

Background: To prevent work-related ill-health, selection of workers for mandatory occupational health surveillance should be based on the actual risk of work-related disease.

Aims: (i) To determine the proportion of sick-listed workers with self-reported work-related health problems not under mandatory occupational health surveillance. (ii) To determine whether self-reported work-related sickness absences occur more frequently among workers under mandatory occupational health surveillance or among workers not under mandatory surveillance.

Modeling the haloperoxidases: reversible oxygen atom transfer between bromide ion and an oxo-Mn(V) porphyrin.

The manganese meso-dimethylimidazolium porphyrin complex Mn(III)[TDMImP] reacted with HOBr/OBr(-) to generate the corresponding oxo-Mn(V)[TDMImP] species. The rate of this process accelerated with increasing pH. A forward rate constant, k(for), of 1.

Design and synthesis of manganese porphyrins with tailored lipophilicity: investigation of redox properties and superoxide dismutase activity.

Thirteen new manganese porphyrins and two porphodimethenes bearing one to three different substituents at the meso positions in a variety of architectures have been synthesized. The substituents employed generally are (i) electron-withdrawing to tune the reduction potential to the desirable range (near +0.3V vs NHE), and/or (ii) lipophilic to target the interior of lipid bilayer membranes and/or the blood-brain barrier.

An analysis of the communication during an enhanced and structured information exchange between social insurance physicians and occupational physicians in disability management in Belgium.

Purpose: The overall objective of this study was to analyse the inter-physician communication during an intervention that aimed at enhancing and structuring the information exchange practices among Belgian social insurance physicians and occupational physicians. We aimed at determining: (i) the communication frequency; (ii) the communication content; and (iii) the type of patients for whom social insurance physicians want communication with occupational physicians.

Method: We analysed inter-physician information exchange data derived from communication forms.

Does enhanced information exchange between social insurance physicians and occupational physicians improve patient work resumption? A controlled intervention study.

Background: Patient work resumption after sickness absence varies even among patients with similar pathologies and characteristics. Explanations remain uncertain. One newly investigated field is "information asymmetry", a situation in which critical information is not appropriately exchanged between stakeholders in disability management.

Dynamics of carbon monoxide binding to cystathionine beta-synthase.

Cystathionine beta-synthase (CBS) condenses homocysteine, a toxic metabolite, with serine in a pyridoxal phosphate-dependent reaction. It also contains a heme cofactor to which carbon monoxide (CO) or nitric oxide can bind, resulting in enzyme inhibition. To understand the mechanism of this regulation, we have investigated the equilibria and kinetics of CO binding to the highly active catalytic core of CBS, which is dimeric.

Disability management through positive intervention in stakeholders' information asymmetry. A pilot study.

Background: One increasingly attractive hypothesis to account for prolonged sickness absence from work is the presence of 'information asymmetry' among stakeholders. Information asymmetry refers to a situation in which critical information is not (appropriately) exchanged, in this case among those involved in disability management.

Aim: The purpose of this study was to intervene positively in the information asymmetry that currently exists between social insurance physicians and occupational physicians in Belgium.

Return to work after surgery for lumbar disc herniation. A rehabilitation-oriented approach in insurance medicine.

Study Design: An intervention study by the medical advisers of a social security sickness fund on a mandatorily insured patient population after open discectomy for herniated lumbar intervertebral disc. The medical advisers were randomized into two groups: a control group (n = 30) and an intervention group (n = 30).

Objectives: To compare a rehabilitation-oriented approach in insurance medicine focused primarily on early mobilization and early resumption of professional activities with the usual claim-based practice.

Central role of epidermal growth factor (EGF) receptor density in anchorage-independent growth of normal rat kidney cells.

Epidermal growth factor (EGF) receptor levels are known to play a central role in density dependent growth regulation of normal rat kidney (NRK) fibroblasts. Here we show that EGF receptor expression is strongly decreased when NRK cells are cultured under anchorage independent conditions, and that expression is returned to original levels upon cell readherence. Agents that stimulate anchorage independent growth (AIG) of NRK cells in the presence of EGF are shown to upregulate both EGF receptor promoter activity and (125)I-EGF binding capacity.

Phenotypic transformation of normal rat kidney fibroblasts by endothelin-1. Different mode of action from lysophosphatidic acid, bradykinin, and prostaglandin f2alpha.

In the present study, we compared the effects of endothelin (ET)-1 on cell proliferation and second messenger induction in normal rat kidney (NRK) fibroblasts, with those of other activators of G-protein-coupled receptors such as prostaglandin (PG)-F2alpha, bradykinin (BK), and lysophosphatidic acid (LPA). LPA is mitogenic by itself, while the other factors require the presence of EGF. In density-arrested NRK cells, ET-1 and LPA induce phenotypic transformation rapidly, with similar kinetics as retinoic acid (RA) and transforming growth factor (TGF)-beta, while BK and PGF2alpha only do so with delayed kinetics.

Epidermal growth factor (EGF) receptor density controls mitogenic activation of normal rat kidney (NRK) cells by EGF.

Normal rat kidney (NRK) fibroblasts are immortalized cells that are strictly dependent on externally added growth factors for proliferation. When cultured in the presence of epidermal growth factor (EGF) as the only growth stimulating hormone, these cells have a normal phenotype and undergo density-dependent growth inhibition. It has been postulated that this density-arrest results from a decrease of EGF receptor levels below a threshold level which makes these cells unresponsive to stimulation by EGF.

Effect of bradykinin on loss of density-dependent growth inhibition of normal rat kidney cells.

Normal rat kidney fibroblasts, density-arrested in the presence of epidermal growth factor (EGF), can be restimulated to proliferate in a synchronous way and acquire a transformed phenotype following treatment with additional growth factors like retinoic acid (RA) and transforming growth factor (TGF)-beta. It was found that bradykinin has a strong inhibitory effect on growth stimulation induced by these factors, an effect which cannot be mimicked by PGF2 alpha. The growth-inhibiting effect can be blocked by inhibitors of cyclo-oxygenase activity, indicating that the relevant second messenger is most likely a prostaglandin.

Survey of cobalt exposure and respiratory health in diamond polishers.

This cross-sectional study was undertaken after the discovery of cobalt-related fibrosing alveolitis and bronchial asthma in diamond polishers occupationally exposed to cobalt. A total of 194 workers from 10 diamond polishing workshops and 59 workers from three other workshops from the diamond industry (control subjects) were studied; a questionnaire was administered and spirometry was performed. Cobalt exposure was assessed by environmental air sampling using both area and personal sampling and by measuring urinary cobalt concentration.

Exposure of diamond polishers to cobalt.

Interstitial pulmonary fibrosis due to 'hard metal' exposure is well known, and the presence of cobalt has always been considered as the causative factor. Recently interstitial pulmonary fibrosis has been described in diamond polishing workers. In this study the dust composition in different polisher's workplaces where diamond disks are in use has been determined.

[Hydrocholecystitis in children and newborn infants. Apropos of 3 cases].

We report two cases of hydrocholecystitis in children and one in a neonate. One child had hepatitis A and the other had typhoid fever. A beta-hemolytic group B streptococcal infection was found in the neonate.

Value of the diagnostic sodium calcium edetate mobilization test as a criterion of lead absorption.

Among the laboratory tests available for the follow-up of lead-exposed workers, the EDTA mobilization test is presently underestimated in the diagnosis of lead intoxication. The authors present the results of regression comparison between the urinary lead excretion 3 h (PbU 3) or 6 h (PbU 6) after EDTA injection and blood lead (PbB), urinary aminolaevulinic acid (ALAU) and urinary lead (PbU). The results were collected from 133 medical examinations of workers exposed to lead, who put in a claim for compensation to the 'Fund of Occupational Diseases' in Belgium.