Co-doped Dy3+ and Pr3+ Ga5Ge20Sb10S65 fibers for mid-infrared broad emission.

Rare earth ion doped materials are means to obtain cost-effective infrared light sources, with enough brilliance for applications such as gas sensing. Within a sulfide matrix, the simultaneous luminescence of both Pr3+ and Dy3+ in the Ga5Ge20Sb10S65 glass is reported. The use of these two rare earths is giving rise to a broad continuous luminescence in the 2.2-5.5 µm wavelength range, which could be used as a mid-infrared light source for gas-sensing applications. The demonstration of CO2 and CH4 detection using a fiber drawn from these materials is reported.

Wavelength conversion in Er(3+) doped chalcogenide fibers for optical gas sensors.

We report for the first time the conversion of incoherent infrared light around 4.4µm into a near-infrared signal at 810nm in erbium-doped GaGeSbS fibers and bulk glass samples. This energy conversion is made possible by pumping erbium doped chalcogenide samples at 982 nm and simultaneously exciting them with a 4.4µm infrared signal. This result paves the way for the development of an "all-optical" gas sensor able to detect various gas traces using a remote detection based on commercial silica fibers.

Study of Ga incorporation in glassy arsenic selenides by high-resolution XPS and EXAFS.

Effect of Ga addition on the structure of vitreous As2Se3 is studied using high-resolution X-ray photoelectron spectroscopy and extended X-ray absorption fine structure techniques. The "8-N" rule is shown to be violated for Ga atoms and, possibly, for certain number of As atoms. On the contrary, Se keeps its 2-fold coordination according to "8-N" rule in the amorphous phase throughout all the compositions. Crystalline inclusions appear in the amorphous structure of the investigated glasses at Ga concentrations greater than 3 at. %. These inclusions are presumably associated with Ga2Se3 crystallites and transition phases/defects formed at the boundaries of these crystallites and host amorphous matrix. The existence of Ga-As and Se-Se bonds in the samples with higher Ga content is supported by present studies.

Structural evolution of Ga-Ge-Te glasses by combined EXAFS and XPS analysis.

The structural evolution of GaxGeyTe100-x-y glasses in the vicinity of GeTe4-GaTe3 pseudo-binary tie-line is determined with high-resolution X-ray photoelectron (XPS) and extended X-ray absorption fine structure (EXAFS) spectroscopies. The analysis of XPS data is complicated by similar electronegativity values for the constituent chemical elements, but then the interpretation is facilitated by information from complementary EXAFS analysis of the structure around each element independently. The results show 4∕4∕2 coordination for Ga∕Ge∕Te atoms and absence of Ga(Ge)-Ge(Ga) bonds or extended Te clusters in significant concentrations within the whole range of studied composition. The observed structural features correlate well with the measured basic physical properties of Ga-containing germanium telluride glasses.

77Se solid-state NMR investigations on As(x)Se(1-x) glasses using CPMG acquisition under MAS.

(77)Se (I=1/2) solid-state NMR is a very sensitive probe of the local structure of selenide glasses, which themselves are promising for optical applications. In this work, we show that although (77)Se has a low natural abundance (7.58%) and a wide spectral range, the sensitivity can be dramatically increased using Carr-Purcell-Meiboom-Gill (CPMG) trains of rotor-synchronized π pulses during the detection of (77)Se magnetization but may be affected by chemical shift anisotropy when the Magic Angle Spinning rate is not fast enough and by offset effects. The indirect dimension of the T(2)(CPMG)-resolved spectrum shows a strong influence of the J-couplings between naturally occurring (77)Se pairs. The resulting spectra show that the structural model known as "chains crossing model" is not entirely suitable to describe the glassy network of the Se-rich compositions.

Infrared single mode chalcogenide glass fiber for space.

An important measuring technique under study for the DARWIN planet finding mission, is nulling interferometry, enabling the detection of the weak infrared emission lines of an orbiting planet. This technique requires a perfect wavefront of the light beams to be combined in the interferometer. By using a single mode waveguide before detection, wavefront errors are filtered and a virtually perfect plane wavefront is obtained. In this paper the results on the development and the optical characterisation of suitable infrared transmitting chalcogenide glasses and mid-IR guiding optical fibers are reported. Two different perform techniques for manufacturing core-cladding chalcogenide fibers are described. Two types of step index fibers, prepared with Te(2)As(3)Se(5) chalcogenide glasses, offer single mode guidance at 10.6 mum.

Experimental design approach for deposition optimization of RF sputtered chalcogenide thin films devoted to environmental optical sensors.

The development of the optical bio-chemical sensing technology is an extremely important scientific and technological issue for diagnosis and monitoring of diseases, control of industrial processes, environmental detection of air and water pollutants. Owing to their distinctive features, chalcogenide amorphous thin films represent a keystone in the manufacture of middle infrared integrated optical devices for a sensitive detection of biological or environmental variations. Since the chalcogenide thin films characteristics, i.e. stoichiometric conformity, structure, roughness or optical properties can be affected by the growth process, the choice and control of the deposition method is crucial. An approach based on the experimental design is undoubtedly a way to be explored allowing fast optimization of chalcogenide film deposition by means of radio frequency sputtering process. Argon (Ar) pressure, working power and deposition time were selected as potentially the most influential factors among all possible. The experimental design analysis confirms the great influence of the Ar pressure on studied responses: chemical composition, refractive index in near-IR (1.55 µm) and middle infrared (6.3 and 7.7 µm), band-gap energy, deposition rate and surface roughness. Depending on the intended application and therefore desired thin film characteristics, mappings of the experimental design meaningfully help to select suitable deposition parameters.

Free-Volume Nanostructurization in Ga-Modified As2Se3 Glass.

Different stages of intrinsic nanostructurization related to evolution of free-volume voids, including phase separation, crystalline nuclei precipitation, and growth, were studied in glassy As2Se3 doped with Ga up to 5 at. %, using complementary techniques of positron annihilation lifetime spectroscopy, X-ray powder diffraction, and scanning electron microscopy with energy-dispersive X-ray analysis. Positron lifetime spectra reconstructed in terms of a two-state trapping model testified in favor of a native void structure of g-As2Se3 modified by Ga additions. Under small Ga content (below 3 at. %), the positron trapping in glassy alloys was dominated by voids associated with bond-free solid angles of bridging As2Se4/2 units. This void agglomeration trend was changed on fragmentation with further Ga doping due to crystalline Ga2Se3 nuclei precipitation and growth, these changes being activated by employing free volume from just attached As-rich glassy matrix with higher content of As2Se4/2 clusters. Respectively, the positron trapping on free-volume voids related to pyramidal AsSe3/2 units (like in parent As2Se3 glass) was in obvious preference in such glassy crystalline alloys.

Body image perception among men in three countries.

OBJECTIVE: The authors tested the hypothesis that men in modern Western societies would desire to have a much leaner and more muscular body than the body they actually had or perceived themselves to have. METHOD: The height, weight, and body fat of college-aged men in Austria (N=54), France (N=65), and the United States (N=81) were measured. Using the somatomorphic matrix, a computerized test devised by the authors, the men chose the body image that they felt represented 1) their own body, 2) the body they ideally would like to have, 3) the body of an average man of their age, and 4) the male body they believed was preferred by women. The men's actual fat and muscularity was compared with that of the four images chosen. RESULTS: Only slight demographic and physical differences were found among the three groups of men. Modest differences were found between the men's measured fat and the fat of the images chosen. However, measures of muscularity produced large and highly significant differences. In all three countries, men chose a ideal body that was a mean of about 28 lb (13 kg) more muscular than themselves and estimated that women preferred a male body about 30 lb (14 kg) more muscular than themselves. In a pilot study, however, the authors found that actual women preferred an ordinary male body without added muscle. CONCLUSIONS: The wide discrepancy between men's actual muscularity and their body ideals may help explain the apparent rise in disorders such as muscle dysmorphia and anabolic steroid abuse.

Autologous bone marrow transplantation using TBI and CBV for disseminated high/intermediate grade cutaneous non-epidermotropic non-Hodgkin's lymphoma.

Patients with stage IV high/intermediate grade cutaneous non-epidermotropic lymphoma of skin as first localization of the disease have a poor prognosis. In this setting, autologous bone marrow transplantation (BMT) has rarely been evaluated. We report here on the treatment of four patients with such lymphomas with autologous BMT using 12 Gy total body irradiation (TBI) and CBV (cyclophosphamide, carmustine and etoposide). Using a plexiglass screen, TBI delivered an homogenized dose to the skin. With this conditioning regimen, all patients are still in complete remission 22, 44, 46 and 51, respectively, months after high-dose chemotherapy, TBI and autologous BMT.

Keratinocyte-lymphocyte interaction in cutaneous T-cell lymphoma. Modulation of keratinocyte antigen My7 by a soluble factor produced by T lymphocytes.

OBJECTIVE: To test the hypothesis that the modulation of My7 antigen in the basal keratinocytes is directly related to the effect of dermal lymphocyte infiltrate of epidermotropic cutaneous T-cell lymphoma (CTCL). DESIGN: In vitro study with reconstituted skin model. SETTING: Department of Dermatology of University Hospital, Nantes, France. PATIENTS: Lymphocytes extracted from 11 skin samples with lesions of epidermotropic CTCL (mycosis fungoides, stages IIa to IV) and 6 skin samples with lesions of atopic dermatitis (control population) together with the supernatants of these infiltrating lymphocytes were incubated with normal reconstituted skin samples either alone or in the presence of interferon alfa-2a (10(2) IU/ mL). Moreover, normal peripheral blood mononuclear cells of 7 patients and 4 controls were incubated with reconstituted skin. INTERVENTION: None MAIN OUTCOME MEASURES: None. RESULTS: Ten of 11 samples of lymphocytes extracted from CTCL and 7 of 11 of their supernatants inhibited partially or completely My7 expression by basal cells. NO inhibition was noted for lymphocytes extracted from inflammatory skin or their supernatants. Addition of interferon alfa-2a in a culture medium of extracted lymphocytes or their supernatants blocked inhibition of My7 expression by keratinocytes in 8 of 10 reconstituted skin samples. No abrogation of My7 expression was noted with peripheral mononuclear cells. CONCLUSIONS: Our in vitro study demonstrated a direct and specific interaction between the tumor infiltrate of CTCL and keratinocytes. Moreover, this interaction appeared to be closely associated with a soluble factor produced by the tumor T-cell infiltrate and was at least partially blocked by interferon alfa-2a.

MY7 monoclonal antibody for diagnosis of cutaneous T-cell lymphoma.

Infiltrate in cutaneous T-cell lymphomas (CTCLs) is composed mainly of CD4 helper cells with a phenotype very similar to that of benign cutaneous lymphoid infiltrate. MY7 (CD13) is a monoclonal antibody that is normally expressed on peripheral granulocytes and monocytes but also cross-reacts with an antigen expressed on epidermal basal cells. We studied MY7 expression on basal cells of the epidermis and CD4 cell infiltrate in 34 CTCLs, 11 pseudolymphomas, and 29 other benign cutaneous lesions. An indirect immunofluorescence technique with double labeling and an immunoperoxidase technique were used. We found that in benign inflammatory infiltrate, less than 10% of CD4 cells expressed MY7 antigen associated with normal MY7 monoclonal antibody labeling of basal cells, whereas in CTCLs more than 50% of CD4 tumoral cells in dermis expressed MY7 antigens; however, basal cells were MY7 negative. Thus, it is demonstrated that MY7 monoclonal antibody with its double modulation on epidermis (basal cells) and dermis (CD4 cells) has diagnostic value for differentiating CTCLs with CD4+ MY7+ tumor cells in dermis and MY7-negative basal cells from benign inflammatory lesions with CD4+ MY7- cells in dermis and MY7-positive basal cells. This modulation of MY7 labeling could be related to the secretion of epidermal cytokines.

In vitro induction of basal keratinocyte MY7 antigen expression in cutaneous T-cell lymphoma is associated with response to interferon-alfa therapy.

BACKGROUND: Normal basal cell keratinocytes express an antigen recognized by monoclonal antibody MY7. This expression is lost in cutaneous T-cell lymphoma (CTCL) and may be reinduced under interferon-alfa-2a therapy. We investigated whether similar modulation of MY7 antigen could be obtained in vitro and determined the relationship between in vitro modulation and clinical response. SUBJECTS: We studied MY7 expression by basal cell keratinocytes in reconstituted skin specimens from 10 patients with CTCL and from skin specimens from five control patients and determined its modulation by interferon-alfa-2a and interleukin 1 using the indirect immunofluorescence technique. Concurrently, clinical examination and in vivo immunologic study on cutaneous biopsy specimens were carried out for these 10 patients before and while receiving interferon-alfa-2a therapy. RESULTS: In vitro studies showed that in five control specimens MY7 expression by basal cells was constant without modulation by interferon-alfa-2a or interleukin 1. Two of 10 CTCL specimens spontaneously expressed MY7 antigen while an additional five did so after incubation with interferon-alfa-2a and the last three never did. CONCLUSION: The three patients with CTCL for whom no MY7 expression was observed in reconstituted skin studies were "poor responders" to interferon-alfa-2a therapy. The five patients with CTCL for whom in vitro MY7 expression was induced by interferon-alfa-2a were responders. For the last two patients, results were variable. Thus, in vitro MY7 antigen is expressed in normal basal cell keratinocytes, absent in CTCL basal cell keratinocytes, but can be induced by interferon-alfa-2a. Moreover this in vitro modulation appears to be possibly correlated with interferon-alfa efficacy in vivo.

Metabolic imaging of tissues by infrared fiber-optic spectroscopy: an efficient tool for medical diagnosis.

Infrared fingerprints of molecules in biology contain much information on cells metabolism allowing one to distinguish between healthy and altered tissues. Here, to collect infrared signatures, we used evanescent wave spectroscopy based on an original infrared transmitting tapered glass fiber. A strict control of the fiber diameter in the tapered sensing zone allows high sensitivity and wide spectral range exploration from 800 to 3000 cm(-1). Then, merely in depositing the mouse liver biopsies on the fiber, this device has enable us to differentiate between tumorous and healthy tissues.

Role of aluminium in skin reactions after diphtheria-tetanus-pertussis-poliomyelitis vaccination: an experimental study in rabbits.

The occurrence of subcutaneous nodules at the injection site is one of the complications of diphtheria-tetanus-pertussis-poliomyelitis vaccination, but the causes and mechanisms involved are still poorly understood. An experimental study in the New Zealand rabbit enabled us to determine the frequency of occurrence of these nodules, how long they persist and the histopathologic features of the cells involved. Aluminium (Al) assays by electrothermal atomic absorption spectrometry allowed us to study concentrations both in nodules and the organism (serum, normal skin). The results show an absence of Al diffusion outside nodules, a correlation between infiltrate intensity and Al concentration in nodules and modifications in the histological constituents of nodule cells. The histological picture indicates a foreign body reaction to Al. All these data underscore the role of Al in the formation of early postvaccinal nodules at the injection site.

In situ sensing of volatile organic compounds in groundwater: first field tests of a mid-infrared fiber-optic sensing system.

A prototype mid-infrared sensor system for the determination of volatile organic pollutants in groundwater was developed and tested under real-world conditions. The sensor comprises a portable Fourier transform infrared spectrometer, coupled to the sensor head via mid-infrared transparent silver halide fiber-optic cables. A 10 cm unclad middle section of the 6-m-long fiber is coated with ethylene propylene copolymer in order to enrich the analytes within the penetration depth of the evanescent field protruding from the fiber sensor head. A mixture of tetrachloroethylene, dichlorobenzene, diethyl phthalate, and xylene isomers at concentrations in the low ppm region was investigated qualitatively and quantitatively in an artificial aquifer system filled with Munich gravel. This simulated real-world site at a pilot scale enables in situ studies of the sensor response and spreading of the pollutants injected into the system with controlled groundwater flow. The sensor head was immersed into a monitoring well of the aquifer system at a distance of 1 m downstream of the sample inlet and at a depth of 30 cm. Within one hour, the analytes were clearly identified in the fingerprint region of the IR spectrum (1300 to 700 cm(-1)). The results have been validated by head-space gas chromatography, using samples collected during the field measurement. Five out of six analytes could be discriminated simultaneously; for two of the analytes the quantitative results are in agreement with the reference analysis.

[Pituitary enlargement in congenital adrenal hyperplasia]. / Retentissement hypophysaire d'une hyperplasie congénitale des surrénales.

The aim of the suppression of pituitary adrenal axis in the management of patients with congenital adrenal hyperplasia is to reduce the hypersecretion of adrenal androgens. However, the local consequences of the hyperreactivity of corticotropin cells during inadequate therapy is not well defined. In this case report, we present the observation of a 28-year-old patient with congenital adrenal hyperplasia with inadequate treatment in whom a pituitary enlargement was detected after MR imaging for headaches. This observation underlines the need for a pituitary follow-up in these specific patients.

[Combination of fotemustine-dacarbazine and interferon alpha in the treatment of metastatic malignant melanoma]. / Association fotémustine-dacarbazine et interféron alpha dans le traitement des mélanomes malins métastasés.

In the treatment of disseminated malignant melanoma (DMM), the results obtained with fotemustine associated or not with dacarbazine are promising and those obtained with interféron alpha are also interesting. Therefore, we have investigated the efficacy and the toxicity of a combined chemotherapy with fotemustine-dacarbazine and interferon alpha in DMM. We present in this work our results on 44 patients who entered into this opened study. 37 patients were evaluable. 29 (78.4 p. 100) had previously received one or more cytotoxic chemotherapy. The regimen consisted of an induction treatment with fotemustine (100 mg/m2) on days 1.8, and 60 dacarbazine (400 mg/m2) on days 1, and 60 and subcutaneous injections of interféron (9.10(6) UI) alpha three times weekly. Responding and stabilized patients were given maintenance treatment with a monthly infusion of fotemustine (100 mg/m2) and dacarbazine (400 mg/m2) and interferon alpha carried on at the same dose. The response rate was 10.8 p. 100 (3 PR + 1 CR). Responses have depended on metastatic sites (cerebral site 18,2 p. 100). The median duration of response was 28 weeks. Toxicity was mainly hematologic and was acceptable. These results are not as good as those reported before with fotemustine and dacarbazine. Even if reasons related to patients and protocol could be discussed, the association of interferon alpha, fotemustine and dacarbazine seems devoid of interest during induction treatment.

[Blue rubber bleb nevus]. / Blue rubber bleb naevus.

Blue Rubber Bleb Naevus (BRBN) is characterized by the presence of bluish haemangiomas on the skin and in the digestive tract. We report a new familial case of this rare entity. Analysis of this female patient's pedigree confirmed that BRBN is transmitted as an autosomal dominant trait. In this particular case gastrointestinal haemangiomas appeared over a 4-year period. Although all treatments of this disease have proved disappointing on the skin as well as in the digestive tract, we insist on the need for a regular and prolonged surveillance.

[Epstein-Barr virus research by in situ hybridization in 65 cutaneous T cell epidermotropic lymphomas]. / Recherche de l'Epstein-Barr virus par hybridation in situ chez 65 malades atteints de lymphomes cutanés T épidermotropes.

BACKGROUND: The Epstein-Barr virus (EBV) is a highly mutagenic virus known to be the cause of several types of lymphoma. There has been some controversy concerning EBV in cutaneous T-cell lymphomas. The aim of this study was to search for EBV with a sensitive method: in situ hybridization in 65 patients with cutaneous T-cell lymphomas. PATIENTS AND METHODS: From 1990 to 1995, 158 samples from 65 patients with cutaneous T-cell lymphoma (2 stage IA, 12 IB, 4 IIA, 29 IIB, 16 Sézary syndrome, 2 stage IV) were collected. In situ hybridization with EBER and Bam W probes recognizing the viral latency genes were used to search for EBV. RESULTS: EBV was evidenced with at least one of the two probes in 43 samples (26 p. 100). Prior to alpha interferon treatment, 18 p. 100 of the samples were positive for EBER compared with 18 p. 100 for Bam W. After alpha interferon treatment, there was a significantly higher percentage of EBER positive samples (39 p. 100; p = 0.03). Inversely, there was no difference for the Bam W probe (p = 0.2). Clinical stage had no effect on the presence of EBV (p = 0.18). CONCLUSION: Our series evidenced the variable presence of EBV, identified by in situ hybridization, in cutaneous T-cell lymphoma. Few infiltrating cells are infected. This would be an argument in favor of an indirect role of the EBV in the transformation process. In addition, alpha interferon increases the life time of EBERs, sensitizing detection of this latency gene.