Determination and benchmarking of 27Al(d,α) and 27Al(d,p) reaction cross sections for energies and angles relevant to NRA.

The cross-sections of deuteron-induced nuclear reactions suitable for ion beam analysis, measured in different laboratories, are often significantly different. In the present work, differential cross-sections of 27Al(d,p) and 27Al(d,α) reactions were measured, and the cross sections benchmarked with thick target spectra obtained from pure aluminium for the first time in two independent laboratories. The 27Al(d,p) and (d,α) differential cross-sections were measured between 1.4 and 2 MeV at scattering angles of 165°, 150°, and 135° in the VDGT laboratory in Tehran (Iran), and the same measurements for detector angle of 150° were repeated from scratch, including target making, with independent equipment on the SAFIR platform at INSP in Paris (France). The results of these two measurements at 150° are in good agreement, and for the first time a fitted function is proposed to describe the Al-cross sections for which no suitable theoretical expression exists. The obtained differential cross-sections were validated through benchmarking, by fitting with SIMNRA deuteron-induced particle spectra obtained from a high purity bulk Al target at both labs for deuteron incident energies between 1.6 and 2 MeV. The thick target spectra are well-reproduced. The evaluated and benchmarked cross sections have been uploaded to the ion beam analysis nuclear data library database (www-nds.iaea.org/ibandl/).

Molecular simulation of the water-triolein-oleic acid mixture: Local structure and thermodynamic properties.

An artificial oil-in-water emulsion analogous to those found in bioresources or food matrices is simulated and studied experimentally. It is composed of one of the major natural free fatty acids (the oleic acid, OA) and the corresponding triacylglyceride (trioleic glyceride, or triolein, GTO). Because of the large time and length scales involved, the molecular simulations are done with the Martini force field, a coarse-grained model. This allowed us to study the water-OA-GTO system at different compositions with more than 20 000 molecules and up to 2 µs. Interfacial tension was measured using the pendant drop method and compared with molecular simulation results. We observe very good agreement at high OA concentrations and deviations up to 15% at low OA concentrations. The water solubility in the lipid phase is in fair agreement with experiments, between 0.03 and 0.32 mol/l, rising with the OA content. The area occupied by OA and GTO at the interface between water and the pure product fitted with experimental data (AOA = 36.6 Å2 and AGTO = 152.1 Å2). The consistency between simulation and experimental results allowed a structural analysis of the interface. A bilayer structure of the lipids at the water/oil interface is proposed, containing preferentially oleic acid but also triolein. Through all these results, the usefulness of coarse-grained simulation for the description of water-oil interfacial organization is demonstrated. This method will be used later to bring local information on the organization of target compounds, necessary in biomass fractionation processes or food additive formulations, for example.

Sequestration of bovine seminal plasma proteins by different assemblies of phosphatidylcholine: A new technical approach.

Binder of SPerm (BSP) proteins, the main proteins from bovine seminal plasma, are known to partially intercalate into the outer leaflet of the spermatozoa membrane and bind to choline-containing lipids being present therein. This insertion generates a negative effect on semen quality after cryopreservation by inducing an early-stage capacitation of spermatozoa. The assumption of surface properties exhibited by BSP proteins was checked by tensiometry measurements: BSP proteins are highly surface active. This suggests that BSP proteins can reach the interface covered by phospholipids not only by interactions between one and each other but also due to their own surface activity. The insertion of BSP proteins into the lipid domains outer leaflet of spermatozoa was reproduced on a biomimetic system such as Langmuir monolayers. The insertion of BSP proteins can be performed in the compressible fluid domains which contain choline-bearing lipids. Monolayer films were used as well to study the complexation of BSP proteins by two phospholipid assemblies: low density lipoprotein (LDLs) from egg yolk or liposomes produced from egg phospholipids. Irrespective of the phospholipid structure (lipoprotein or liposome), BSP was hindered to alter the structure of the membrane. Only the overall ratio BSP proteins:phosphatidylcholine was important. The difference between the two sequestering agents lies on their surface properties: LDL have a strong tendency to merge with the outer layer whereas liposomes mainly remain in the bulk on the same time scale.

Organization of lipids in the artificial outer membrane of bull spermatozoa reconstructed at the air-water interface.

Cryopreservation is widely used to preserve the quality of bull spermatozoa over time. Sequestration of seminal plasma proteins by low density lipoproteins and formation of a protective film around the spermatozoa membrane by low density lipoproteins were the main mechanisms proposed. However, the organization of lipids in the outer leaflet of the spermatozoa membrane has been never considered as a possible parameter. This study evaluated whether a change in the organization of the outer leaflet of the spermotozoa membrane could occur during cooling down. The organization of the main components of the spermatozoa membrane's outer layer at the liquid-gas interface was analysed. Cryopreservative media (at 8° and 34°C) were used to study the miscibility of the spermatozoa membrane lipids using epifluorescence imaging and by tensiometry on Langmuir films. The results show that the four lipids: sphingomyelin, cholesterol, 1-palmitoyl-2-docosahexaenoyl-sn-glycero-3-phosphocholine (PC) and plasmalogen 1-(1Z-octadecenyl)-2-docosahexaenoyl-sn-glycero-3-phosphocholine (P-PC) were not fully miscible and their organization was controlled by temperature. Cholesterol and sphingomyelin form condensed domains surrounded by a mixture of PC and P-PC at 34°C while these condensed domains are surrounded by separated domains of pure PC and pure P-PC at 8°C. The organization of the outer membrane lipids, in particular the separation of PC and P-PC lipids during cooling down, must be considered to fully understand preservation of membrane integrity during cryopreservation.

Interfacial interaction between transmembrane ocular mucins and adhesive polymers and dendrimers analyzed by surface plasmon resonance.

PURPOSE: Development of the first in vitro method based on biosensor chip technology designed for probing the interfacial interaction phenomena between transmembrane ocular mucins and adhesive polymers and dendrimers intended for ophthalmic administration. METHODS: The surface plasmon resonance (SPR) technique was used. A transmembrane ocular mucin surface was prepared on the chip surface and characterized by QCM-D (Quartz Crystal Microbalance with Dissipation) and XPS (X-ray photoelectron spectroscopy). The mucoadhesive molecules tested were: hyaluronic acid (HA), carboxymethyl cellulose (CMC), hydroxypropylmethyl cellulose (HPMC), chitosan (Ch) and polyamidoamine dendrimers (PAMAM). RESULTS: While Ch originated interfacial interaction with ocular transmembrane mucins, for HA, CMC and HPMC, chain interdiffusion seemed to be mandatory for bioadherence at the concentrations used in ophthalmic clinical practise. Interestingly, PAMAM dendrimers developed permanent interfacial interactions with transmembrane ocular mucins whatever their surface chemical groups, showing a relevant importance of co-operative effect of these multivalent systems. Polymers developed interfacial interactions with ocular membrane-associated mucins in the following order: Ch(1 %) > G4PAMAM-NH(2)(2 %) = G4PAMAM-OH(2 %) > G3.5PAMAM-COOH(2 %)>> CMC(0.5 %) = HA(0.2 %) = HPMC(0.3 %). CONCLUSIONS: The method proposed is useful to discern between the mucin-polymer chemical interactions at molecular scale. Results reinforce the usefulness of chitosan and dendrimers as polymers able to increase the retention time of drugs on the ocular surface and hence their bioavailability.

[Medical abortion from 12 through 14 weeks' gestation: a retrospective study with 126 patients]. / L'interruption volontaire de grossesse médicamenteuse de 12 à 14 semaines d'aménorrhée : étude rétrospective portant sur 126 patientes.

OBJECTIVE: To assess the efficacy of medical abortion performed according to a single protocol from 12 through 14 weeks. STUDY DESIGN: Retrospective observational study of medical abortions from 12 through 14 weeks performed from January 2007 through March 2009. The protocol combined 600 mg de mifepristone orally, followed 48 h later by 400 µg of misoprostol, administered orally, and repeated after 3h, four times a day (during two days), if patient did not begin to abort. Outcome measures were the abortion rate, the rate of complication, the rate of manual uterine revision or vacuum aspiration, the time of expulsion and the misoprostol dose. RESULTS: The study included 126 medical abortions. The abortion rate was 98% and the secondary manual revision or vacuum aspiration rate was 41%. The mean time to expulsion was 10.4 (±8.8)h, and the mean misoprostol dose 1040 (±420) µg. Higher parity was significantly correlated with shorter time to expulsion (P=0.02). CONCLUSION: Medical abortion was consistently effective from 12 through 14 weeks but with high rate of secondary manual revision or vacuum aspiration.

Evaluation of the specific interactions between glycodendrimeric porphyrins, free or incorporated into liposomes, and concanavalin A by fluorescence spectroscopy, surface pressure, and QCM-D measurements.

In photodynamic therapy, the specificity of a photosensitizer and its penetration into tumor cells are crucial. We have analyzed the ability of newly synthesized meso-(tetraphenyl)porphyrins to be recognized by a model of mannose-specific proteins overexpressed at the surface of retinoblastoma cells. The specific interaction of porphyrin with Con A was studied by surface pressure measurements, fluorescence spectroscopy, dynamic light scattering, and QCM-D. The extent of porphyrins binding to Con A was highly dependent upon their chemical structure. Glycodendrimeric porphyrins showed the higher binding constant to Con A. The length of the spacer separating the sugar from the tetrapyrrolic ring appeared to be crucial in controlling the interaction of the compounds with the lectin in solution or immobilized onto a solid substrate. The methodology used proved to be efficient for the selection of potentially active compounds. The glycodendrimeric porphyrins, especially the derivative having the longer spacer, interacted more significantly with the lectin than the compound devoid of any sugar.

Spatiotemporal variations in microcystin concentrations and in the proportions of microcystin-producing cells in several Microcystis aeruginosa populations.

With the aim of explaining the variations in microcystin (MC) concentrations during cyanobacterial blooms, we studied several Microcystis aeruginosa populations blooming in different freshwater ecosystems located in the same geographical area. As assessed by real-time PCR, it appeared that the potentially MC-producing cells (mcyB(+)) were predominant (70 to 100%) in all of these M. aeruginosa populations, with the exception of one population in which non-MC-producing cells always dominated. Apart from the population in the Grangent Reservoir, we found that the proportions of potentially MC-producing and non-MC-producing cells varied little over time, which was consistent with the fact that according to a previous study of the same populations, the intergenic transcribed spacer (ITS) genotype composition did not change (38). In the Grangent Reservoir, the MC-RR variant was the dominant microcystin variant throughout the bloom season, despite changes in the ITS composition and in the proportions of mcyB(+) cells. Finally, the variations in total MC concentrations (0.3 to 15 microg liter(-1)) and in the MC cellular quotas (0.01 to 3.4 pg cell(-1)) were high both between and within sites, and no correlation was found between the MC concentrations and the proportion of mcyB(+) cells. All of these findings demonstrate that very different results can be found for the proportions of potentially MC-producing and non-MC-producing cells and MC concentrations, even in M. aeruginosa populations living in more or less connected ecosystems, demonstrating the importance of the effect of very local environmental conditions on these parameters and also the difficulty of predicting the potential toxicity of Microcystis blooms.

Development of a pilot-scale 1 for Legionella elimination in biofilm in hot water network: heat shock treatment evaluation.

AIMS: (i) To develop an analytical tool in order to evaluate the effectiveness of anti-Legionella treatment in biofilm and (ii) study the fate of Legionella populations in water and biofilm after applying a heat shock treatment. METHODS AND RESULTS: A pilot-scale unit simulating a hot water system was built and designed by the Scientific and Technical Building Centre (CSTB, France). At the end of the contamination period, a stable cultivable Legionella spp. concentration of 5x10(5) CFU l(-1) was obtained. Two heat shock treatments (70 degrees C for 30 min) were applied. The results showed that the first treatment had a transitional effect on the abatement of Legionella concentrations, while the second treatment had no detectable effect on Legionella populations in water and biofilm. The DAPI (4',6'-diamidino-2-phenylindole), Legionella PCR and GVPC (glycocolle vancomycin pyrophosphate cycloheximide) counts measured in the dead leg water of the Test Loop were 1, 2 and 2 log units higher than results found in the Test Loop water. Moreover, Legionella spp. count in tap water was about 10(4) GU l(-1). These analyses revealed that they are responsible for the rapid recolonization as well as the uncomplete destroyed biofilm. In addition, a resistance test was conducted and showed that Legionella in the second heat shock treatment was not thermo-resistant but thermo-acclimated. CONCLUSION: Thermal disinfection does not seem to be efficient enough to eliminate Legionella when it is used as a curative treatment. SIGNIFICANCE AND IMPACT OF THE STUDY: This work could help water managers for a better management of water network and for a better control of Legionella.

[Basal cell carcinoma of the first toenail]. / Carcinome basocellulaire de l'appareil unguéal de l'hallux.

BACKGROUND: Basal cell carcinoma is a very common form of skin cancer but its occurrence on the toenail unit is very rare. We report such a case of basal cell carcinoma localized on the proximal nail fold of the right hallux. CASE REPORT: A 67-year-old woman had a 7-year history of a non-healing ulcer on the proximal nail fold of the right hallux after antibiotics and treatment of her onychomycosis. Bowen's disease and squamous cell carcinoma were suspected. Histopathologic examination of a biopsy specimen revealed infiltrative basal cell carcinoma. The lesion was surgically excised with a 0.5 cm margin and the defect was repaired by full-thickness skin graft with good functional and cosmetic results. DISCUSSION: Basal cell carcinoma is the most common skin cancer but its localization on fingers, toes and nail units is very rare. Only six cases of basal cell carcinoma on the toe nail unit have been reported to date in the literature. Clinical aspects often mimic benign processes, resulting in misdiagnosis. Treatment requires simple excision or Mohs micrographic surgery. Our case emphasizes the value of biopsy for all nail unit lesions of atypical appearance, course or therapeutic response.

Self-assembled monolayers of peptide nucleic acids on gold surfaces: a spectroscopic study.

We have characterized self-assembled monolayers (SAMs) of thiol-derivatized peptide nucleic acid (PNA) chains adsorbed on gold surfaces by using reflection absorption infrared spectroscopy (RAIRS) and X-ray photoemission spectroscopy (XPS) techniques. We have found that the molecular orientation of PNAs strongly depends on surface coverage. At low coverage, PNA chains lie flat on the surface, while at high coverage, PNA molecules realign their molecular axes with the surface normal and form SAMs without the need of co-immobilization of spacers or other adjuvant molecules. The change in the molecular orientation has been studied by infrared spectroscopy and it has been confirmed by atomic force microscopy (AFM). PNA immobilization has been followed by analyzing the N(1s) XPS core-level peak. We show that the fine line shape of the N(1s) core-level peak at optimal concentration for biosensing is due to a chemical shift. A combination of the above-mentioned techniques allow us to affirm that the structure of the SAMs is stabilized by molecule-molecule interactions through noncomplementary adjacent nucleic bases.

Egg yolk phosvitin: preparation of metal-free purified protein by fast protein liquid chromatography using aqueous solvents.

Two chromatographic methods for hen egg yolk phosvitin purification avoiding organic solvents were evaluated. Hydrophobic interaction and ion-exchange chromatographies were applied to isolated phosvitin. Hydrophobic interaction chromatography has better capacity than ion-exchange chromatography to fractionate phosvitin in their different polypeptides, but its protein yield was lower (0.7 vs. 1.7% of egg yolk dry matter). Finally, ion-exchange chromatography was selected and allowed to fractionate phosvitin polypeptides, including the recovering of phosphoproteins with high electrophoretic mobility: phosvettes. Highly purified (>98%) and free metal protein was obtained in reduced time. Phosvitin polypeptide heterogeneity was evidenced.

Quantitative and kinetic evolution of wound healing through image analysis.

To define a healing function based on parameters measured on digitized images of wounds, and to use it to compare the rate of healing of two skin graft donor sites, one treated with petrolatum gauze (Pg) and the other with a topical preparation containing alginates (A). Digital photographs of donor sites (depth 0.6 mm) taken every two days between day 6 and day 12 were analyzed blind using the same algorithm, following changes in color and homogeneity. Analysis of variance was used to identify those parameters that changed during healing. The healing function was constructed using measurements made in six patients (group 1) randomly chosen from ten requiring skin grafts, and was applied and validated using data from the remaining four patients (group 2). The results given by this healing function were compared with those provided by principal component analysis. The most significant healing parameters were those measuring wound homogeneity, and our healing function reflects how these change with time. The time-dependent curves of the function calculated for groups 1 and 2 matched well enough to be considered as being derived from the same set of measurements. The results given by this healing function explained, by analogy, the meaning of the first principal component of principal component analysis. From day 6 to day 12, the healing function followed the same time-course for the Pg and A treatments, but healing was achieved significantly earlier (4 days, p < 0.03) with A. This suggests that the effect of A on wound healing is achieved in the first six days, before the visual changes from epidermalization are analyzable.

Can one lung ventilation prevent air embolism in the lung injury victim?

The current literature indicates that patients with hilar lung injury who are receiving positive pressure ventilation are at risk for systemic air embolism, but no studies have yet tested an alternative to the current management: immediate thoracotomy and hilar clamping. We wanted to demonstrate that one lung ventilation of the uninjured lung protects against the formation of arterial air embolism in the presence of contralateral hilar lung injury.In 6 juvenile swine, the right bronchus was selectively ventilated, and ultrasound of the abdominal aorta was used to detect air emboli. The hilum of the left lung was stabbed with a scalpel; after a brief period of monitoring to detect air emboli, the tip of the endotracheal tube was withdrawn into the trachea and the left lung ventilated.Air emboli were detected in 2 animals. The air emboli did not form while the lung was isolated, but they did appear immediately when the endotracheal tube was withdrawn into the trachea. Air was also noted in the chambers of the heart and coronary arteries, and led to fibrillation and death.One lung ventilation appears to protect against arterial air embolism in unilateral hilar lung injury. (Curr Surg 57:349-353)

Kinematics of prehension and pointing movements in C6 quadriplegic patients.

AIMS: C6 quadriplegic patients lack voluntary control of their triceps muscle but can still perform reaching movements to grasp objects or point to targets. The present study documents the kinematic properties of reaching in these patients. MATERIALS AND METHODS: We investigated the kinematics of prehension and pointing movements in four quadriplegic patients and five control subjects. Prehension and pointing movements were recorded for each subject using various object positions (ie different directions and distances from the subject). The 3D motion was analyzed with Fastrack Polhemus sensors. RESULTS: During prehension tasks the velocity profile of control subjects showed two peaks (go and return); the first velocity peak was scaled to the distance of the object. In quadriplegic patients there was a third intermediary peak corresponding to the grasping of the object. The amplitude of the first peak was slightly smaller than in control subjects. Velocity was scaled to the distance of the object, but with a greater dispersion than in control subjects. Total movement time was longer in quadriplegics because of the prolonged grasping phase. There were few differences in the pointing movements of normal and quadriplegic subjects. The scapula contributed more to the reaching phase of both movements in quadriplegic patients. CONCLUSION: In spite of some quantitative differences, the kinematics of the hand during reaching and pointing in quadriplegic patients are surprisingly similar to those of control subjects. Spinal Cord (2000) 38, 354 - 362.

Lipolysis in muscles during refrigerated storage as related to the metabolic type of the fibres in the rabbit.

The relation between lipolysis and the metabolic fibre type was investigated during refrigerated storage of rabbit muscles. Free fatty acid, monoacylglycerol and diacylglycerol contents and free fatty acid composition were compared in five muscles immediately after slaughter and after a 7-day-storage at 4°C. The results showed that. (1) The amount of free fatty acids sharply increased during the refrigerated storage (from 2-10 to 11-32 mg/100 g of muscle), especially that of long chain polyunsaturated fatty acids (from less than 0.1 to 1.4-3.3 mg/100 g of muscle). (2) The glycolytic muscles contained 1.5 times less free fatty acids than the oxidative ones. However, the rates of phospholipid and triacylglycerol hydrolysis were not related to the metabolic type of the fibres. (3) The contribution of phospholipids to free fatty acid fraction was twice that of triacylglycerols in the glycolytic muscles whereas it was similar or lower to that of triacylglycerols in the oxidative muscles.

Comparison of adjuvants with Leishmania antigens in a guinea pig model to induce delayed-type hypersensitivity responses.

BACKGROUND AND PURPOSE: Guinea pigs have been a traditional model for studies of delayed-type hypersensitivity. They are the natural host of Leishmania enriettii and have been experimentally infected with other species of Leishmania. They have been used as a skin-test model to screen potential antigens for use in diagnostic tests for Leishmania. Use of complete Freund's adjuvant (CFA), along with whole promastigote Leishmania antigen, was necessary to sensitize guinea pigs to invoke a sufficient cell-mediated immune response. However, use of CFA has come under scrutiny by Animal Care and Use Committees due to the pathologic changes associated with its use. METHODS: Thirty-two specific-pathogen-free male Hartley guinea pigs were inoculated with Leishmania antigens alone or mixed with one of three adjuvants (CFA, TiterMax, and liposomes), and were skin tested 2 weeks later. RESULTS: For the Leishmania antigens tested, guinea pigs that received liposomes as an adjuvant had skin-test responses comparable to those of guinea pigs that received CFA. TiterMax was also tested, but cellular responses at antigen test sites were poor. CONCLUSIONS: Liposomes can be used in this model as a safe, effective adjuvant.