Small footprint phase locking system for a large tiled aperture laser array

A phase sensing system fitted to the control of coherent laser beam array of large cross section is experimented. It is based on the use of a fiber bundle that collects a weak part of the synthetic wavefront, that scales it down (1/40) and that reshapes it in a more compact arrangement (2D to 1D array). Then, the reconfigured beam array can be analyzed by a small footprint system making the large laser beam array easier to phase-lock. The discrete laser array wavefront transmitted by the meter long fiber bundle was stabilized thanks to a multiple arm servo loop. Laser array phase locking was further ensured by random scattering through a diffuser, associated to an alternating projection algorithm. Six fiber laser beams constituting a 110 mm diameter synthetic aperture, were phase-locked with λ/16 accuracy.

Chernobyl and Fukushima nuclear accidents: what has changed in the use of atmospheric dispersion modeling?

The threat of a major accidental or deliberate event that would lead to hazardous materials emission in the atmosphere is a great cause of concern to societies. This is due to the potential large scale of casualties and damages that could result from the release of explosive, flammable or toxic gases from industrial plants or transport accidents, radioactive material from nuclear power plants (NPPs), and chemical, biological, radiological or nuclear (CBRN) terrorist attacks. In order to respond efficiently to such events, emergency services and authorities resort to appropriate planning and organizational patterns. This paper focuses on the use of atmospheric dispersion modeling (ADM) as a support tool for emergency planning and response, to assess the propagation of the hazardous cloud and thereby, take adequate counter measures. This paper intends to illustrate the noticeable evolution in the operational use of ADM tools over 25 y and especially in emergency situations. This study is based on data available in scientific publications and exemplified using the two most severe nuclear accidents: Chernobyl (1986) and Fukushima (2011). It appears that during the Chernobyl accident, ADM were used few days after the beginning of the accident mainly in a diagnosis approach trying to reconstruct what happened, whereas 25 y later, ADM was also used during the first days and weeks of the Fukushima accident to anticipate the potentially threatened areas. We argue that the recent developments in ADM tools play an increasing role in emergencies and crises management, by supporting stakeholders in anticipating, monitoring and assessing post-event damages. However, despite technological evolutions, its prognostic and diagnostic use in emergency situations still arise many issues.

A large single-center experience with allogeneic stem-cell transplantation for peripheral T-cell non-Hodgkin lymphoma and advanced mycosis fungoides/Sezary syndrome

BACKGROUND

The prognosis for patients with most forms of T-cell lymphoma is poor. Allogeneic hematopoietic stem-cell transplantation (HSCT) may improve the outcome.

PATIENTS AND METHODS

This study examines the outcome of 52 patients who underwent ablative or nonablative allogeneic HSCT for peripheral T-cell lymphoma (PTCL) or advanced mycosis fungoides/Sezary syndrome over a 12-year period at a single institution. We divided the patients into those with predominantly nodal histologies: peripheral T-cell not otherwise specified (PTCL NOS), angioimmunoblastic (AITL), or anaplastic large cell lymphoma, T/null type (systemic) (ALCL), and predominantly extranodal histologies: natural killer (NK)/T cell, enteropathy type, hepatosplenic, subcutaneous panniculitic, mycosis fungoides, or T cell or NK cell other.

RESULTS

Median follow-up of survivors is 49 months. Non-relapse mortality and relapse at 3 years was 27% and 43%, respectively. The incidence of grade II-IV acute graft-versus-host disease (GVHD) was 21%. The incidence of extensive chronic GVHD at 2 years was 27%. The 3-year progression-free survival was 30%: 45% in patients with predominantly nodal histologies (PTCL NOS, AITL, and ALCL) and 6% in patients with predominantly extranodal histologies (P = 0.016). Overall survival at 3 years was 41% for all patients.

CONCLUSION

Allogeneic HSCT can produce long-term remissions in relapsed/refractory T-cell lymphoma, especially those with nodal histologies.

Outcome of allo-SCT for women with MDS or AML occurring after breast cancer therapy

Women with breast cancer who receive adjuvant therapy are at risk for developing therapy-related myelodysplastic syndrome (MDS) or AML (tMDS/AML). Patients with tMDS/AML are often referred for consideration of allogeneic hematopoietic SCT (HSCT). However, the outcomes of HSCT in such patients have not been well described. We report a retrospective study of all women who were treated with HSCT for MDS or AML at our institution between 1991 and 2008. We compared the transplantation outcomes for 24 women with a history of breast cancer with those for 271 women with de novo disease. Three-year OS and disease-free survival (DFS) for patients with a history of breast cancer were 41 and 45%, respectively. The cumulative incidences of tMDS/AML relapse and non-relapse mortality (NRM) were 38 and 17%, respectively. Those outcomes were very similar to those of patients with de novo disease. In multivariable analyses, a history of breast cancer had no impact on OS, DFS, relapse or NRM. A significant proportion of women with tAML/MDS after breast cancer treatment experience DFS after HSCT, similar to that of patients with de novo MDS or AML. This justifies consideration of HSCT for selected patients in this setting.

Measurement and modelling of radioxenon plumes in the Ottawa Valley

Since 2001 a real-time radiation monitoring network of Canadian nuclear facilities and major population centres has been implemented for response to nuclear incidents including a possible terrorist attack. Unshielded NaI(Tl) spectroscopic detectors are employed to measure gamma radiation from airborne radioactivity and radioactivity deposited on the ground. These detectors are composed of a standard 3''x3'' cylindrical NaI(Tl) spectrometers with data storage and integrated telemetry. Some of the detectors have been deployed in the Ottawa Valley near Chalk River Laboratories and Ottawa, which has a complex radioxenon environment due to the proximity of nuclear power reactors, and medical isotope facilities. Although not a health threat, these releases have provided an opportunity for the Canadian Meteorological Centre and the Commissariat à l'Energie Atomique to validate their meteorological models. The meteorological models of the two organizations are in good agreement on the origin and the source terms of these releases.

K3Ga2(PO4)3 and Na3Ga(PO4)2

The structures of tripotassium digallium tris(phosphate), K3Ga2(PO4)3, and trisodium gallium bis(phosphate), Na3Ga(PO4)2, have different irregular one-dimensional alkali ion-containing channels along the a axis of the orthorhombic and triclinic unit cells, respectively. The anionic subsystems consist of vortex-linked PO4 tetrahedra and GaO4 tetrahedra or GaO5 trigonal bipyramids in the first and second structure, respectively.

A high-temperature Raman scattering study of the phase transitions in GaPO(4) and in the AlPO(4)-GaPO(4) system

Al(1-x)Ga(x)PO(4) solid solutions (x = 0.2, 0.3, 0.38, 0.7) and the pure AlPO(4) (x = 0) and GaPO(4) (x = 1) end members with the α-quartz-type structure were studied by Raman scattering. An investigation as a function of composition enabled the various modes to be assigned, in particular coupled and decoupled vibrations. The tetrahedral tilting modes, which have been linked to high-temperature phase transitions to β-quartz-type forms, were found to be decoupled. In addition, it is shown that Raman spectroscopy is a powerful technique for determining the gallium content of these solid solutions. Single crystals with x = 0.2, 0.38, and 1.0 (GaPO(4)) were investigated at high temperature. The composition Al(0.8)Ga(0.2)PO(4) was found to exhibit sequential transitions upon heating to the β-quartz and β-cristobalite forms at close to 993 K and 1073 K, respectively. Direct α-quartz-β-cristobalite transitions were observed for the two other compositions at close to 1083 K and 1253 K, respectively, upon heating. The spectra of the β-quartz and β-cristobalite forms indicate the presence of significant disorder. Back transformation to the α-quartz-type form occurred readily with a hysteresis of less than 100 K for the composition x = 0.38 and for pure GaPO(4). Rapid cooling was necessary to obtain the metastable α-cristobalite form. In contrast, for Al(0.80)Ga(0.20)PO(4), the α-cristobalite form was obtained even upon slow cooling.

Chiral N-substituted glycines can form stable helical conformations

BACKGROUND

Short sequence-specific heteropolymers of N-substituted glycines (peptoids) have emerged as promising tools for drug discovery. Recent work on medium-length peptoids containing chiral centers in their sidechains has demonstrated the existence of stable chiral conformations in solution. In this report, we explore the conformational properties of these N alpha chiral peptoids by molecular mechanics calculations and we propose a model for the solution conformation of an octamer of (S)-N-(1-phenylethyl)glycine.

RESULTS

Molecular mechanics calculations indicate that the presence of N-substituents in which the N alpha carbons are chiral centers has a dramatic impact on the available backbone conformations. These results are supported by semi-empirical quantum mechanical calculations and coincide qualitatively with simple steric considerations. They suggest that an octamer of (S)-N-(1-phenylethyl)glycine should form a right-handed helix with cis amide bonds, similar to the polyproline type I helix. This model is consistent with circular dichorism studies of these molecules.

CONCLUSIONS

Peptoid oligomers containing chiral centers in their sidechains present a new structural paradigm that has promising implications for the design of stably folded molecules. We expect that their novel structure may provide a scaffold to create heteropolymers with useful functionality.

NMR determination of the major solution conformation of a peptoid pentamer with chiral side chains

Polymers of N-substituted glycines ("peptoids") containing chiral centers at the alpha position of their side chains can form stable structures in solution. We studied a prototypical peptoid, consisting of five para-substituted (S)-N-(1-phenylethyl)glycine residues, by NMR spectroscopy. Multiple configurational isomers were observed, but because of extensive signal overlap, only the major isomer containing all cis-amide bonds was examined in detail. The NMR data for this molecule, in conjunction with previous CD spectroscopic results, indicate that the major species in methanol is a right-handed helix with cis-amide bonds. The periodicity of the helix is three residues per turn, with a pitch of approximately 6 A. This conformation is similar to that anticipated by computational studies of a chiral peptoid octamer. The helical repeat orients the amide bond chromophores in a manner consistent with the intensity of the CD signal exhibited by this molecule. Many other chiral polypeptoids have similar CD spectra, suggesting that a whole family of peptoids containing chiral side chains is capable of adopting this secondary structure motif. Taken together, our experimental and theoretical studies of the structural properties of chiral peptoids lay the groundwork for the rational design of more complex polypeptoid molecules, with a variety of applications, ranging from nanostructures to nonviral gene delivery systems.

Sequence-specific polypeptoids: a diverse family of heteropolymers with stable secondary structure

We have synthesized and characterized a family of structured oligo-N-substituted-glycines (peptoids) up to 36 residues in length by using an efficient solid-phase protocol to incorporate chemically diverse side chains in a sequence-specific fashion. We investigated polypeptoids containing side chains with a chiral center adjacent to the main chain nitrogen. Some of these sequences have stable secondary structure, despite the achirality of the polymer backbone and its lack of hydrogen bond donors. In both aqueous and organic solvents, peptoid oligomers as short as five residues give rise to CD spectra that strongly resemble those of peptide alpha-helices. Differential scanning calorimetry and CD measurements show that polypeptoid secondary structure is highly stable and that unfolding is reversible and cooperative. Thermodynamic parameters obtained for unfolding are similar to those obtained for the alpha-helix to coil transitions of peptides. This class of biomimetic polymers may enable the design of self-assembling macromolecules with novel structures and functions.

Pressor effect of oral tyramine during treatment with befloxatone, a new reversible monoamine oxidase-A inhibitor, in healthy subjects

The interaction between tyramine and befloxatone, a new selective, reversible monoamine oxidase-A (MAO-A) inhibitor, was studied in a single-blind, parallel-group study in 30 healthy male volunteers whose fasting tyramine 30 dose (Tyr30) was 400 or 600 mg. Each subject completed a placebo run-in period followed by a befloxatone period. Befloxatone was given in repeated doses according to one of three regimens: befloxatone 20 mg once daily at the end of a meal rich in tyramine or befloxatone 10 or 20 mg twice daily 2 hours before a meal rich in tyramine. Subjects were given increasing daily doses of tyramine mixed with the meal, until a systolic blood pressure increase of at least 30 mm Hg was achieved (Tyr30). The mean Tyr30 decreased from 1220 mg (range, 600-1800 mg) during placebo to 290 mg (range, 150-500 mg) during befloxatone 20 mg once daily, 250 mg (range, 100-300) during befloxatone 10 mg twice daily, and 155 mg (range, 100-250 mg) during befloxatone 20 mg twice daily; corresponding to a potentiation factor of 5.2-, 6.5-, and 7.9-fold, respectively. The extent and the duration of the systolic blood pressure increase did not significantly differ between the placebo and the befloxatone regimens, except for a longer duration with the 20-mg twice daily regimen. These results are similar to those reported with the therapeutic dosage of other selective MAO-A inhibitors. They suggest that there would be little risk of hypertensive crisis in patients treated in clinical studies with befloxatone, and thus dietary restrictions appear to be unnecessary when the drug is given in a regimen of up to 20-mg once daily after meals.

[Pharmacokinetics of low-dose lithium in healthy volunteers]

The pharmacokinetics of lithium in healthy volunteers receiving low doses of lithium as Lithium Oligosol by sublingual route were investigated in two randomized crossover studies (lithium vs placebo) with a two week wash-out period. In the first study, 8 volunteers received a single dose (1.68 mg) of lithium and in the second 8 another volunteers received repetitive doses of lithium (0.56 mg twice a day) during 11 days. The plasma concentration of lithium was determined by an electrothermal atomic absorption spectrometry. The plasma concentrations of lithium measured during the placebo period were about 1 microgram/L, the peak concentration was 99.4 +/- 22.2 micrograms/L in the single dose study and 49.6 +/- 5.4 micrograms/L in the multiple doses study. In this last one, the residual plasma levels of lithium were between 20 and 25 micrograms/L. The pharmacokinetics parameters measured were: T1/2 = 22.6 +/- 3.1 h; Vd/F = 0.70 +/- 0.09 L/kg and Cl/F = 1.53 +/- 0.12 L/h. The plasma concentrations of lithium are strictly dependent on intake from food or drugs.

A novel basic helix-loop-helix protein is expressed in muscle attachment sites of the Drosophila epidermis

We have found that a novel basic helix-loop-helix (bHLH) protein is expressed almost exclusively in the epidermal attachments sites for the somatic muscles of Drosophila melanogaster. A Drosophila cDNA library was screened with radioactively labeled E12 protein, which can dimerize with many HLH proteins. One clone that emerged from this screen encoded a previously unknown protein of 360 amino acids, named delilah, that contains both basic and HLH domains, similar to a group of cellular transcription factors implicated in cell type determination. Delilah protein formed heterodimers with E12 that bind to the muscle creatine kinase promoter. In situ hybridization with the delilah cDNA localized the expression of the gene to a subset of cells in the epidermis which form a distinct pattern involving both the segmental boundaries and intrasegmental clusters. This pattern was coincident with the known sites of attachment of the somatic muscles to tendon cells in the epidermis. delilah expression persists in snail mutant embryos which lack mesoderm, indicating that expression of the gene was not induced by attachment of the underlying muscles. The similarity of this gene to other bHLH genes suggests that it plays an important role in the differentiation of epidermal cells into muscle attachment sites.