D Simon - Academia.edu (original) (raw)

Papers by D Simon

Molecular and Cellular Biology, 1988

Expression of the epidermal growth factor (EGF) was analyzed in six human hepatocellular carcinom... more Expression of the epidermal growth factor (EGF) was analyzed in six human hepatocellular carcinoma-derived and one human hepatoblastoma-derived cell line, each of which retained the differentiated phenotype and functions of the parenchymal hepatocyte. The level of receptor expression of each hepatoma cell line was similar to that of the normal human fibroblast, approximately 10(5) molecules per cell. However, NPLC/PRF/5, a subline of the PLC/PRF/5 cell line obtained following reestablishment of a xenograft tumor in vitro, was found to express 4 x 10(6) high-affinity EGF receptor molecules per cell. Proliferation of the NPLC/PRF/5 cell line was inhibited in the presence of nanomolar quantities of ligand. Receptor overexpression was found to result from EGF receptor gene amplification without apparent rearrangement of the EGF receptor coding sequences. Although cell-specific variability in posttranslational processing of EGF receptor N-linked oligosaccharides in the hepatoma cell line...

Surface Science, 2006

Catalytic hydrogenation of aromatic compounds is an important process in petroleum industry. Unde... more Catalytic hydrogenation of aromatic compounds is an important process in petroleum industry. Understanding it through experimental or theoretical research can help to improve its efficiency. This work presents a first principles density functional theory study of the intermediates for the first four hydrogenations steps of the smallest aromatic compound, benzene, into C6H10 species, on two popular catalytic metals, palladium and platinum, described by periodic models. Different structures have been studied for the intermediate C6H6+n species, with a various degree of conservation of the conjugation. Some intermediates would present in gas phase a closed-shell conjugated structure, while other would correspond to multiple radicals with a massive destruction of the benzene π system. The Pd and Pt(111) surfaces strongly differ in terms of most stable structure for the intermediates. On Pd the most conjugated intermediates, i.e. the most stable in gas phase, is clearly preferred. In contrast, on Pt, multiple radical species, highly unstable in gas phase, are strongly stabilized by coupling with the surface. This thermodynamic study indicates a different trend for the hydrogenation mechanism: a clear successive 1–2–3… hydrogenation of neighboring carbon atoms on Pd keeping the largest conjugated fragment, and a nonconsecutive attack, with a maximum breaking of benzene conjugation on Pt.

International Journal of Obesity, 1998

OBJECTIVE: To assess ethnic differences in androgenic status related to non insulin-dependent dia... more OBJECTIVE: To assess ethnic differences in androgenic status related to non insulin-dependent diabetes mellitus (NIDDM) in male and female Melanesians and Europeans of New Caledonia. DESIGN: This is a case-control study nested in a prevalence study for diabetes mellitus in the multiracial population of New Caledonia. SUBJECTS: 186 male subjects were included in the survey (77 Melanesians and 16 Europeans in each case and control group). Each case and control group included 104 female Melanesian subjects (69 premenopausal and 35 postmenopausal). METHODS: Diabetic subjects were matched for age, gender, ethnic group and location, with healthy normoglycaemic subjects. Testosterone levels in men and sex hormone-binding globulin (SHBG) levels in women (measured by radioimmunoassay, RIA) were compared between NIDDM and control subjects in relation to obesity, central adiposity and insulin levels. RESULTS: In both ethnic groups, NIDDM was associated with lower testosterone levels but there was a marked difference among Europeans. Testosterone was negatively associated with the body mass index (BMI) (r 70.35, P`0.01) and fasting insulin (r 70.37, P`0.001) in control Melanesians only. In Melanesian women, NIDDM was associated with lower SHBG levels in pre-and postmenopausal women (P`0.001). SHBG mean level was not associated with menopausal status. CONCLUSION: Our results con®rm in a Paci®c population that NIDDM is associated with low levels of testosterone in men and low levels in SHBG in women. In contrast to white populations, Melanesian women have a more androgenic pro®le, whatever their menopausal status.

Revue de Physique Appliquée, 1970

Journal de Chimie Physique et de Physico-Chimie Biologique, 1999

The first part of this work is a qualitative and quantitative study of the corrosion of a materia... more The first part of this work is a qualitative and quantitative study of the corrosion of a material, constituted of brass covered with an electrochemical nickel coating (thickness &amp;ap;5~mum) and with a gold coating (thickness &amp;ap;0.4~mum or &amp;ap;1~mum), used in electrical contact applications. Tests of corrosion have been carried out in the humid synthetic air (humidity ratio varying from 15%

Eosinophils in Health and Disease, 2013

Gene regulation 10.3 % Granule proteins 11.3 % Metabolism 7.6 % Cytoskeleton/Migration 24.7 % FIG... more Gene regulation 10.3 % Granule proteins 11.3 % Metabolism 7.6 % Cytoskeleton/Migration 24.7 % FIGURE 13.2.2 Distribution of the eosinophil proteins according to their biological functions. The largest proportion of proteins is related to the cytoskeleton and metabolism of the cell. However, as much as 11% of total proteins identified are granule secretory components. PTM, posttranslational modification.

The Journal of Physical Chemistry B, 2001

We present total energy and NO stretching frequency calculations for the low-coverage adsorption ... more We present total energy and NO stretching frequency calculations for the low-coverage adsorption of NO on palladium-manganese Pd 3 Mn (100) and (111) surfaces, on the basis of density-functional theory periodic calculations. A complete description of all the different adsorption sites and corresponding NO vibrations is given and a theoretical interpretation of the experimental IR spectra is proposed. On both Pd 3 Mn (100) and (111) surfaces, the highly coordinated vertical adsorption sites are always energetically favored. The atop adsorption on the surface manganese atom is also a stable site. On Pd 3 Mn (100), a new horizontal dibridge site is reported. The adsorption on these palladium-manganese alloy surfaces is weaker than the adsorption on the pure corresponding palladium surfaces. The anharmonic NO stretching frequencies on the Pd 3 Mn surfaces are shifted by 60-100 cm-1 toward the lower frequencies by comparison with the pure palladium surfaces. The weakening of the adsorption strength and the global shift for the NO frequencies has been correlated with the presence of the surface manganese atoms, which play a predominant role for the electronic interactions between the magnetic NO molecule and the alloy periodic surface. An interpretation of the alloying effect on the strength of the NO bond and the NO adsorption is proposed on the basis of a qualitative Mulliken population analysis. The empty states on the surface manganese atoms are responsible for an increased electron-transfer toward NO, and hence of the smaller vibrational frequency on the alloy compared to pure Pd. Indeed these empty states interact with the π* NO and push it below the Fermi level, resulting in a transfer from the "surface electron reservoir" toward the π* NO molecular orbital.

Physical Review Letters, 2005

Journal of Hepatology, 2001

Journal of Biomedical Materials Research Part B: Applied Biomaterials, 2013

Neural interfaces have traditionally been fabricated on rigid and planar substrates, including si... more Neural interfaces have traditionally been fabricated on rigid and planar substrates, including silicon and engineering thermoplastics. However, the neural tissue with which these devices interact is both 3D and highly compliant. The mechanical mismatch at the biotic-abiotic interface is expected to contribute to the tissue response that limits chronic signal recording and stimulation. In this work, novel ternary thiol-ene=acrylate polymer networks are used to create softening substrates for neural recording electrodes. Thermomechanical properties of the substrates are studied through differential scanning calorimetry and dynamic mechanical analysis both before and after exposure physiological conditions. This substrate system softens from more than 1 GPa to 18 MPa on exposure to physiological conditions: reaching body temperature and taking up less than 3% fluid. The impedance of 177 mm 2 gold electrodes electroplated with platinum black fabricated on these substrates is measured to be 206 kX at 1 kHz. Specifically, intracortical electrodes are fabricated, implanted, and used to record driven neural activity. This work describes the first substrate system that can use the full capabilities of photolithography, respond to physiological conditions by softening markedly after insertion, and record driven neural activity for 4 weeks. V

Journal of Autism and Developmental Disorders, 2013

Children with ASD demonstrate significant heterogeneity in their profiles of social interaction a... more Children with ASD demonstrate significant heterogeneity in their profiles of social interaction and stress responsivity. We evaluated behavior and stress response in 52 male children ages 8 to 12 in a naturalistic playground interaction paradigm involving a child with autism spectrum disorder, a typically developing peer, and a same-age confederate. Younger children in the ASD group engaged in 5.8 times more approach behavior and showed a lower cortisol response than their older peers. Those that verbally initiated with their peers also showed a higher cortisol response. Older children with ASD exhibited the highest stress responsivity, while younger children with ASD showed more willingness to approach others without apparent stress. Intervening early and often may contribute to improvements in social engagement in youth with ASD.

Journal of Animal Breeding and Genetics, 1987

Chronic circadian dysfunction impairs declarative memory in humans but has little effect in commo... more Chronic circadian dysfunction impairs declarative memory in humans but has little effect in common rodent models of arrhythmia caused by clock gene knockouts or surgical ablation of the suprachiasmatic nucleus (SCN). An important problem overlooked in these translational models is that human dysrhythmia occurs while SCN circuitry is genetically and neurologically intact. Siberian hamsters (Phodopus sungorus) are particularly well suited for translational studies because they can be made arrhythmic by a one-time photic treatment that severely impairs spatial and recognition memory. We found that once animals are made arrhythmic, subsequent SCN ablation completely rescues memory processing. These data suggest that the inhibitory effects of a malfunctioning SCN on cognition require preservation of circuitry between the SCN and downstream targets that are lost when these connections are severed. Deficits in cognitive performance caused by disrupted circadian timing have become a growing concern among health care professionals (1). Recent clinical studies have found that age-related declines in circadian function can lead to mild cognitive impairment or dementia (2, 3). These memory deficits are not simply a consequence of poorer sleep, because reductions in circadian rhythm amplitude and robustness can accelerate progression of mild cognitive impairment or dementia even when sleep quality is maintained (2, 3). The observation that circadian timing is substantially weakened among people with Alzheimer's disease has raised the possibility that cognitive deficits might be treated by improving circadian function (4-6). However, there are no mouse or rat models of adult-onset circadian dysfunction in genetically and neurologically intact animals living in standard laboratory conditions.

Journal für die reine und angewandte Mathematik (Crelles Journal), 2009

This is the second in a series of papers in which we study the n-Selmer group of an elliptic curv... more This is the second in a series of papers in which we study the n-Selmer group of an elliptic curve. In this paper, we show how to realize elements of the n-Selmer group explicitly as curves of degree n embedded in P n−1. The main tool we use is a comparison between an easily obtained embedding into P n 2 −1 and another map into P n 2 −1 that factors through the Segre embedding P n−1 ×P n−1 → P n 2 −1. The comparison relies on an explicit version of the local-to-global principle for the n-torsion of the Brauer group of the base field.

IEEE Transactions on Control Systems Technology, 1993

Experimental and Clinical Endocrinology & Diabetes, 2009

Retinoic acids (RA) regulate growth and differentiation of normal epithelial tissue. They have be... more Retinoic acids (RA) regulate growth and differentiation of normal epithelial tissue. They have been employed in anticancer treatment and showed positive effects in hematopoetic and various epithelial tumors. Experimental data with follicular thyroid tumor cells showed strong evidence of induction of differentiated cell function and antiproliferative effects. Based on these data a consecutive series of 10 patients with advanced thyroid carcinoma were treated with 13-cis-retinoic acid (Roaccutan) 1.5 mg/kg body weight for six weeks. Follow-up demonstrated renewed uptake of radioiodine in 4 of 10 patients allowing performance of further radioiodine therapy. Reduction in tumor size due to antiproliferative effects of RA could not yet be verified.

Diabetes & Metabolism, 2007

In France, prevalence of drug-treated diabetes reached 3.60% in 2005, with 92% of type 2 diabetic... more In France, prevalence of drug-treated diabetes reached 3.60% in 2005, with 92% of type 2 diabetic patients. In 2007, there are probably nearly 3 000 000 diagnosed or undiagnosed diabetic patients. Ageing of the population and increase in obesity are the main causes of this "diabetes epidemic". Type 2 diabetes is a multifactorial disease, defined as resulting from defects in insulin secretion (including abnormalities in pulsatility and kinetics, quantitative and qualitative abnormalities of insulin, β-cell loss progressing with time) associated with insulin resistance (affecting liver, and skeletal muscle) and increased glucagon secretion. The lack of compensation of insulin resistance by augmented insulin secretion results in rise in blood glucose. To achieve satisfactory glycaemic control in order to prevent diabetes related complications, drug therapy is generally required in addition to life style changes. Currently available oral therapies offer a large panel of complementary drugs, but they have several contraindications and side effects. In spite of major advances in the management of type 2 diabetes, and the strictness of new guidelines, some goals remain unachieved and the new family of insulin-secretors (DPP-IV inhibitors, GLP-1 analogues) should enrich therapeutic approaches.

Dermatology, 2006

Background: Controlled studies established the efficacy and good tolerability of pimecrolimus cre... more Background: Controlled studies established the efficacy and good tolerability of pimecrolimus cream 1% for the treatment of atopic dermatitis but they may not reflect real-life use. Objective: To evaluate the efficacy, tolerability and cosmetic acceptance of a pimecrolimus-based regimen in daily practice in Switzerland. Methods: This was a 6-month, open-label, multicentre study in 109 patients (55% ≧18 years) with atopic dermatitis. Pimecrolimus cream 1% was incorporated into patients’ standard treatment protocols. Results: The pimecrolimus-based treatment was well tolerated and produced disease improvement in 65.7% of patients. It was particularly effective on the face (improvement rate: 75.0%). Mean pimecrolimus consumption decreased from 6.4 g/day (months 1–3) to 4.0 g/day (months 3–6) as disease improved. Most patients (74.1%) rated their disease control as ‘complete’ or ‘good’ and 90% were highly satisfied with the cream formulation. Conclusion: The use of a pimecrolimus-based ...

Der Hautarzt, 2007

... topische Kortikosteroide oder Tacroli-mus, D-Penicillinamin, Penizillin, intralä- sionäres In... more ... topische Kortikosteroide oder Tacroli-mus, D-Penicillinamin, Penizillin, intralä- sionäres Interferon-γ, UVA1, Psoralen plus UVA (PUVA), photodynamische Thera-pie (PDT ... wIRA führte bei unserer Patientin zu einer deutlichen Abnahme der Sklerosie-rung und Krankheitsaktivität ...

Clinical Chemistry and Laboratory Medicine (CCLM), 2006

Background: Severe traumatic brain injury (TBI) is associated with a 30%-70% mortality rate. S100... more Background: Severe traumatic brain injury (TBI) is associated with a 30%-70% mortality rate. S100B has been proposed as a biomarker for indicating outcome after TBI. Nevertheless, controversy has arisen concerning the predictive value of S100B for severe TBI in the context of multitrauma. Therefore, our aim was to determine whether S100B serum levels correlate with primary outcome following isolated severe TBI or multitrauma in males. Methods: Twenty-three consecutive male patients (age 18-65 years), victims of severe TBI wGlasgow Coma Scale (GCS) 3-8x (10 isolated TBI and 13 multitrauma with TBI) and a control group consisting of eight healthy volunteers were enrolled in this prospective study. Clinical outcome variables of severe TBI comprised: survival, time to intensive care unit (ICU) discharge, and neurological assessment wGlasgow Outcome Scale (GOS) at ICU dischargex. Venous blood samples were taken at admission in the ICU (study entry), 24 h later, and 7 days later. Serum S100B concentration was measured by an immunoluminometric assay.