Operating Quantum States in Single Magnetic Molecules: Implementation of Grover's Quantum Algorithm.

Quantum algorithms use the principles of quantum mechanics, such as, for example, quantum superposition, in order to solve particular problems outperforming standard computation. They are developed for cryptography, searching, optimization, simulation, and solving large systems of linear equations. Here, we implement Grover's quantum algorithm, proposed to find an element in an unsorted list, using a single nuclear 3/2 spin carried by a Tb ion sitting in a single molecular magnet transistor. The coherent manipulation of this multilevel quantum system (qudit) is achieved by means of electric fields only. Grover's search algorithm is implemented by constructing a quantum database via a multilevel Hadamard gate. The Grover sequence then allows us to select each state. The presented method is of universal character and can be implemented in any multilevel quantum system with nonequal spaced energy levels, opening the way to novel quantum search algorithms.

Prevalence of cholecystolithiasis and its management among kidney/pancreas-transplanted type 1 (insulin-dependent) diabetic patients.

BACKGROUND: Simultaneous pancreas/kidney transplantation (SPK) should be the procedure of choice for (pre)uremic patients with type 1 diabetes. All standard immunosuppressive protocols for SPK include a calcineurin-inhibitor. Both calcineurin inhibitors, cyclosporine (CyA) and probably tacrolimus (FK506) too, are associated with the occurrence of cholelithiasis due to their metabolic side effects. PATIENTS AND METHODS: We evaluated the prevalence of cholelithiasis in 83 kidney/pancreas transplanted type I-diabetic patients (46 males, 37 females, mean age 42.8 +/- 7.5 years) by conventional B-mode ultrasound 5 years after transplantation. 56 patients received CyA (group 1) and 27 received tacrolimus (group 2) as first-line-immunosuppressive drug. Additional immunosuppression consisted of steroids, azathioprine or mycophenolate mofetil. Additionally, laboratory analyses of cholestasis parameters (gamma-GT and alcalic phosphatasis) were performed. RESULTS: In total, 23 patients (28%) revealed gallstones and 52 patients (62%) revealed a completely normal gallbladder. In eight patients (10%) a cholecystectomy was performed before or during transplantation because of already known gallstones. No concrements in the biliary ducts (choledocholithiasis) could be detected. In group 2 the number of patients with gallstones was slightly lower (22%) compared with group 1 patients (30%), but without statistical significance. - Cholestasis parameters were not increased and HbA1c values were normal in both groups of patients. CONCLUSION: The prevalence of biliary disease in kidney/pancreas transplanted type I-diabetic patients with 28% is increased in comparison to the general population (10-15%). Lithogenicity under tacrolimus seems to be lower as under cyclosporine based immunosuppressive drug treatment. We recommend regular sonographical examinations to detect an acute or chronic cholecystis as early as possible, which may develop occultly in these patients.

Cloning and sequencing of IS1086, an Alcaligenes eutrophus insertion element related to IS30 and IS4351.

A new insertion sequence (IS), designated IS1086, was isolated from Alcaligenes eutrophus CH34 by being trapped in plasmid pJV240, which contains the Bacillus subtilis sacB and sacR genes. The 1,106-bp IS1086 element contains partially matched (22 of 28 bp) terminal-inverted repeats and a long open reading frame. Hybridization data suggest the presence of one copy of IS1086 in the strain CH34 heavy-metal resistance plasmid pMOL28 and at least two copies in its chromosome. Analysis of the IS1086 nucleotide sequence revealed striking homology with two other IS elements, IS30 and IS4351, suggesting that they are three close members in a family of phylogenetically related insertion sequences. One open reading frame of the Spiroplasma citri phage SpV1-R8A2 B was also found to be related to this IS family but to a lesser extent. Comparison of the G+C contents of IS30 and IS1086 revealed that they conform to their respective hosts (46 versus 50% for IS30 and Escherichia coli and 64.5% for IS1086 and A. eutrophus). The pressure on the AT/GC ratio led to a very different codon usage in these two closely related IS elements. Results suggesting that IS1086 transposition might be activated by some forms of stress are discussed.

Characterization of amber mutations in bacteriophage Mu transposase: a functional analysis of the protein.

We have characterized a series of amber mutations in the A gene of bacteriophage Mu encoding the phage transposase. We tested different activities of these mutant proteins either in a sup0 strain or in different sup bacteria. In conjunction with the results described in the accompanying paper by Bétermier et al. (1989) we find that the C-terminus of the protein is not absolutely essential for global transposase function, but is essential for phage growth. Specific binding to Mu ends is defined by a more central domain. Our results also reinforce the previous findings (Bétermier et al., 1987) that more than one protein may be specified by the A gene.

[Influence of blood pressure on the progression rate of advanced chronic renal insufficiency]. / Influence de la pression artérielle sur la vitesse de progression de l'insuffisance rénale chronique avancée.

Influence of systemic arterial pressure on the progression rate of renal function in patients with advanced CRF is still controversial. In a retrospective analysis of 167 patients with well-characterized primitive nephropathy, we analyzed the influence of mean arterial pressure (MAP), either treated or untreated, on the progression rate of CRF as judged by the time interval elapsed between plasma creatinine 500 mumol/l and first iterative hemodialysis (500-HD). In the whole group, mean 500-HD interval was 15.5 +/- 10.5 months (mean +/- SD). Linear regression analysis showed a weak correlation between MAP and 500-HD (r = -0.20; p less than 0.02). Significant correlation could not be found in subgroup analysis of patients with chronic glomerulonephritis (n = 68), angionephrosclerosis (n = 22), or polycystic kidney disease (n = 35). A significant negative correlation between MAP and 500-HD was demonstrated in the subgroup of 42 patients with chronic interstitial nephritis (r = -0.47; p less than 0.002). Stratification analysis according to MAP values did not reveal significant differences in 500-HD interval except for the patients with MAP less than or equal to 95 mmHg whose 500-HD was 24.7 +/- 18.4 months versus 14.7 +/- 9.0 months in patients with MAP greater than 95 mmHg (p less than 0.001). These results suggest that MAP may not be a determinant factor in the progression rate of advanced CRF, except possibly for patients with chronic interstitial nephritis and/or very low MAP.