Asking photons where they have been.

We present surprising experimental evidence regarding the past of photons passing through an interferometer. The information about the positions through which the photons pass in the interferometer is retrieved from modulations of the detected signal at the vibration frequencies of mirrors the photons bounce off. From the analysis we conclude that the past of the photons is not represented by continuous trajectories, although a "common sense" analysis adopted in various welcher weg measurements, delayed-choice which-path experiments, and counterfactual communication demonstrations yields a single trajectory. The experimental results have a simple explanation in the framework of the two-state vector formalism of quantum theory.

[ISO 9001-2000 certification for refractive laser treatment]. / Certification ISO 9001-2000 des traitements réfractifs par laser cornéen.

PURPOSE: To obtain ISO 9001-2000 certification for laser corneal refractive treatment, never before sought in Europe. MATERIAL AND METHODS: The consulting firm Veritas led the certification process with the clinic's staff manager. This ISO norm is dedicated to the implementation of a quality management system. We assessed and optimized all necessary resources, evaluating customer satisfaction using patient and referring-physician surveys. We started quality rounds including surgeons, nurses, and technicians. Based on this preparation, we redefined and explained all processes including staff responsibilities and necessary resources in the quality manual. The procedure lasted 14 months with substantial involvement on the part of the management. RESULTS: Unconditional ISO 9001-2000 certification was granted by the independent audit firm, BVQI, in december 2003 for refractive laser treatment. CONCLUSION: The 2000 version of the new ISO 9001-2000 seeks to meet the demand for improving health care delivery in this field, most particularly by establishing a clear procedural orientation. Such certification enhances team work, stabilizes methodologies, and reinforces cohesion and self-audit. Patients notice that the center follows a consistent quality policy and are assured that the clinic respects rules and regulations. Certification is an advantageous alternative when accreditation cannot be considered. Our article discusses the steps taken in upper management, quality management, procedural guidance, as well as customer and staff counselling. It also discusses the project's cost/benefit ratio for the organization.

beta-Glycosides of 2,3-Diazido-2,3-dideoxy-D-mannose, a Synthetic Precursor of a Rare Bacterial Cell-Wall Building Unit.

2,3-Diazido-2,3-dideoxy-beta-D-mannopyranoside derivatives were synthesized in order to prepare beta-glycosides of 2,3-diacetamido-2,3-dideoxy-D-mannuronic acid, a rare moiety of bacterial oligosaccharides. A direct glycosyl donor, 4,6-di-O-acetyl-2,3-diazido-2,3-dideoxy-alpha-D-mannopyranosyl bromide, was prepared, and its synthetic capacity was tested in glycosylation reactions. An indirect route was also elaborated: 3-azido-3-deoxy-beta-D-glucopyranosides were converted into beta-D-mannopyranosides. The cis vicinal diazido function successfully tolerated the conditions of mild acidic hydrolysis, tritylation, Jones oxidation, TEMPO oxidation, acetolysis, and bromination with TiBr(4).

Synthesis and antiparasitic activities of amidinic azolated derivatives.

A set of heterocyclic N-acetamidinium hydrochlorides were prepared from the corresponding N-acetonitriles. The antiparasitic screening showed that, while all amidines are practically inactive, some nitriles present leishmanicide properties.

[Synthesis and antiparasitic activity of various N-acetylacetates of nitrogen heterocycles]. / Synthèse et activité antiparasitaire de divers N-éthylacétates d'hétérocycles azotés.

The synthesis and the study of the antiparasitic activity of various heterocyclic N-ethylacetates derived from substituted derivatives of piperazine, benzimidazole and benzotriazole do not show antiparasitic property. A slight activity on Entamoeba histolytica and Trichomonas vaginalis is noted with the nitro derivatives of benzimidazole and benzotriazole.