The glucosinolate-myrosinase system. New insights into enzyme-substrate interactions by use of simplified inhibitors

Myrosinase, a thioglucoside glucohydrolase, is the only enzyme able to hydrolyse glucosinolates, a unique family of molecules bearing an anomeric O-sulfated thiohydroximate function. Non-hydrolysable myrosinase inhibitors have been devised and studied for their biological interaction. Diverse modifications of the O-sulfate moiety did not result in a significant inhibitory effect, whereas replacing the D-glucopyrano residue by its carba-analogue allowed inhibition to take place. X-Ray experiments carried out after soaking allowed for the first time inclusion of a non-hydrolysable inhibitor inside the enzymatic pocket. Structural tuning of the aglycon part in its pocket is being used as a guide for the development of simplified and more potent inhibitors.     

Syntheses of the tedanolides and myriaporones

This review covers the synthetic contributions leading to the syntheses of the polyketides tedanolide, 13-deoxytedanolide and the structurally related myriaporones. Fragment syntheses that lead to valuable insight into the subtle synthetic problems of the tedanolides are also presented.     

Perfect graphs with noP 5 and noK 5

We prove that Berge’s Strong Perfect Graph Conjecture is true for graphs with no induced path on five vertices and no clique of size five.     

Solutions of elliptic equations involving critical Sobolev exponents with neumann boundary conditions

We consider the problem −Δu=|u| ^p−1u+λu in Ω with on δΩ, where Ω is a bounded domain inR ^N ,p=(N+2)/(N−2) is the critical Sobolev exponent,n the outward pointing normal and λ a constant. Our main result is that if Ω is a ball inR ^N , then for every λ∈R the problem admits infinitely many solutions. Next we prove that for every bounded domain Ω inR ³, symmetric with respect to a plane, there exists a constant μ>0 such that for every λ<μ this problem has at least one non-trivial solution. This work was supported by the Paris VI-Leiden exchange program Supported by the Netherlands organisation for scientific research NWO, under number 611-306-016.     

Hybrid multi-objective Bayesian estimation of distribution algorithm: a comparative analysis for the multi-objective knapsack problem

Nowadays, a number of metaheuristics have been developed for efficiently solving multi-objective optimization problems. Estimation of distribution algorithms are a special class of metaheuristic that intensively apply probabilistic modeling and, as well as local search methods, are widely used to make the search more efficient. In this paper, we apply a Hybrid Multi-objective Bayesian Estimation of Distribution Algorithm (HMOBEDA) in multi and many objective scenarios by modeling the joint probability of decision variables, objectives, and the configuration parameters of an embedded local search (LS). We analyze the benefits of the online configuration of LS parameters by comparing the proposed approach with LS off-line versions using instances of the multi-objective knapsack problem with two to five and eight objectives. HMOBEDA is also compared with five advanced evolutionary methods using the same instances. Results show that HMOBEDA outperforms the other approaches including those with off-line configuration. HMOBEDA not only provides the best value for hypervolume indicator and IGD metric in most of the cases, but it also computes a very diverse solutions set close to the estimated Pareto front.     

Phase transitions and vibrational study of Rb2SeO4·Te(OH)6 and Rb1.12(NH4)0.88SO4·Te(OH)6

Calorimetry, conductivity, IR and Raman studies of the two ionic-protonic conductors Rb₂SeO₄·Te(OH)₆ (RbSeTe) and Rb_1.12(NH₄)_0.88SO₄·Te(OH)₆ (RNST) have been recorded and analyzed. These compounds crystallize in the monoclinic system, the space groups being, respectively, P2₁/c and P2₁/a for (RbSeTe) and (RNST) with four formula units in their unit cells.

The main feature of these atomic arrangements is the coexistence of two independent and different types of anions in the unit cell, connected by hydrogen bonds, which insure the cohesion of the crystalline edifice. Differential scanning calorimetry traces show three peaks for both the materials, corresponding to three phase transitions, at 430, 470 and 493 K for RbSeTe and at 418, 458 and 483?K for RNST.

A sudden surge in the temperature dependence of conductivity confirms the presence of the third transition, which is characterized by a high conductivity. The Raman spectra of these two materials were investigated in the range 295–600?K and IR spectra achieved at room temperature between 10 and 4000?cm^?1, confirm the presence of the phase transitions and show that anionic groups coexist independently in the same crystal.     

The reactions of general practitioners, nurses and midwives in Flanders concerning breast cancer risks in a high-risk situation

OBJECTIVE: To investigate the reactions of general practitioners (GPs), nurses and midwives concerning the cancer risks in a high-risk family. METHODS: Questionnaires were sent to 356 GPs, 881 nurses and 119 midwives. RESULTS: The response rate was 60% for GPs, 58% for midwives and 33% for nurses. The breast cancer risk of an unaffected patient from a high-risk family as well as the risk of her daughter were mostly (>80%) correctly evaluated as increased. The percentage answering 'increased risk' dropped to 40% for the daughters of the patient's brother. Half of the GPs and nurses/midwives explicitly mentioned that a predictive DNA test was available. Less than one third would recommend such a test for a young child. Reluctance was also observed regarding prophylactic mastectomy. CONCLUSION: These results should be taken into account in genetic education initiatives for GPs, nurses and midwives.