92 research outputs found

    Application of tunable diode lasers as local oscillators in an Infrared Heterodyne Radiometer (IHR)

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    The utility of diode lasers as local oscillators (LOs) in a heterodyne receiver application was investigated. The CW power, spectral tunability, spectral stability, and spatial intensity distribution of the TDL outputs were measured. A tunable diode laser LO was incorporated into a laboratory Dicke-switched infrared heterodyne setup and used to measure radiometer sensitivity as well as spectroscopic characteristics of selected absorption lines of ammonia. The test results on one of the two tunable diode lasers are emphasized in an attempt to provide a comprehensive data package which may be useful for future planning purposes. The second tunable diode laser exhibits characteristics similar to the fully tested TDL with the exception that some changes in its performance characteristics as it was temperature cycled between room temperature and the operating temperature of approximately 50K occurred

    Fine wavelength id for tunable laser local oscillators

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    A wavelength ID device which consists of an electronic show that the etalon has a finesse F 30 which is maintainable for several days. These tests also demonstrate that the etalon system is capable of resonance frequency stability during similar time periods. With currently available coatings, this level of performance is achievable over an optical bandwidth delta lambda = 3 micrometers centered at lambda = 10 micrometers

    CD157 signaling promotes survival of acute myeloid leukemia cells and modulates sensitivity to cytarabine through regulation of anti-apoptotic Mcl-1.

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    CD157/BST-1 (a member of the ADP-ribosyl cyclase family) is expressed at variable levels in 97% of patients with acute myeloid leukemia (AML), and is currently under investigation as a target for antibody-based immunotherapy. We used peripheral blood and bone marrow samples from patients with AML to analyse the impact of CD157-directed antibodies in AML survival and in response to cytarabine (AraC) ex vivo. The study was extended to the U937, THP1 and OCI-AML3 AML cell lines of which we engineered CD157-low versions by shRNA knockdown. CD157-targeting antibodies enhanced survival, decreased apoptosis and reduced AraC toxicity in AML blasts and cell lines. CD157 signaling activated the PI3K/AKT/mTOR and MAPK/ERK pathways and increased expression of Mcl-1 and Bcl-XL anti-apoptotic proteins, while decreasing expression of Bax pro-apoptotic protein, thus preventing Caspase-3 activation. The primary CD157-mediated anti-apoptotic mechanism was Bak sequestration by Mcl-1. Indeed, the Mcl-1-specific inhibitor S63845 restored apoptosis by disrupting the interaction of Mcl-1 with Bim and Bak and significantly increased AraC toxicity in CD157-high but not in CD157-low AML cells. This study provides a new role for CD157 in AML cell survival, and indicates a potential role of CD157 as a predictive marker of response to therapies exploiting Mcl-1 pharmacological inhibition

    Safety and efficacy of administering 0.2 mg of recombinant human TSH for two consecutive days as an adjuvant to low-dose radioiodine therapy in out-patients with large non-toxic multinodular goitre.

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    Recombinant human TSH (rhTSH) has recently been used as an adjuvant to the treatment of non-toxic multinodular goitre (MNG) by means of 131I. The aim of our study was to evaluate the efficacy of 0.2 mg rhTSH or placebo administered im on 2 consecutive days before a fixed therapeutic dose of 14 mCi of 131I. Thirteen elderly patients (71\ub17 years) with large non-toxic MNG (group 1) were treated with rhTSH plus 131I. While a control group of 8 patients, matched for age and non-toxic MNG volume, was treated with placebo plus 131I (group 2)

    Safety and efficacy of administering 0.2 mg of recombinant human TSH for two consecutive days as an adjuvant to therapy with low radioiodine doses in elderly out-patients with large nontoxic multinodular goiter

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    AIM: The aim of this study was to evaluate the efficacy of recombinant human TSH (rhTSH) as an adjuvant to radioiodine therapy for nontoxic multinodular goiter (MNG) in elderly subjects. METHODS: Twelve elderly out-patients with large MNG (group 1) were studied. The effect of adjuvant rhTSH administration (0.2 mg i.m. on 2 consecutive days) before low-dose (131)I was compared with that of radioiodine alone in 8 out-patients matched for age and MNG volume (group 2). The follow-up period was similar in both groups. RESULTS: The number and severity of side-effects during the first month of treatment were similar in both groups. On final examination, the number of patients symptomatic for goiter was significantly lower in group 1 than in group 2 (P=0.03). In group 1, TSH levels peaked at 40.3+/-9.5 mU/L on day 3, from the baseline value of 0.5+/-0.1 mU/L (P<0.001). In group 2, baseline TSH was 0.4+/-0.1 mU/L. Although a marked increase in f-T3, f-T4 and Tg (P<0.001) was noted in both groups during the first 2 weeks of treatment, peak values were much higher in group 1 than in group 2. On final examination, a slightly significant increase (P=0.01) in TSH levels from the baseline was noted in both groups (group 1: 1.2+/-0.2 mU/L; group 2: 1.4+/-0.3 mU/L). The percentage of patients who did not need therapies to control TSH secretion at the last examination was higher in group 1 (83%) than in group 2 (38%). Only in group 1, a significant reduction was noted in mean anterior-posterior lobar width (31+/-1.7 mm) from the baseline value (24.5+/-1.7 mm, P=0.04). Thyroid volume was reduced from 78.1+/-11.7 mL to 49.4+/-13.4 mL (P=0.001) in group 1 and from 89.8+/-25.2 mL to 67.1+/-20.5 mL (P=0.04) in group 2. Six months after (131)I therapy, slight changes in thyroid length and tracheal lumen were noted in both groups. CONCLUSIONS: This long-term controlled study demonstrates that 0.2 mg of rhTSH on 2 consecutive days increases the efficacy of ambulatory (131)I dosages in treating nontoxic MNG in elderly subjects. Adequate drug preparation generally prevents side-effects due to short-term but marked thyrotoxicosis that is aggravated by rhTSH administration. An increase in thyroid volume reduction seems to be the most important effect of rhTSH administered before (131)I

    Evaluation of effective renal plasma flow with I-127 ortho-iodohippurate and I-123 ortho-iodohippurate in rabbits

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    Preparation of 99mTc-HMPAO: influence of pH, volume recovery and storage conditions of the physiological solution on radiochemical purity and stability.

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    99mTc-HMPAO is currently used to image cerebral blood flow and for in vitro leukocyte labeling. The jield of this liphophilic complex plays an important role in diffusion across the blood brain barrier and in cell labeling. Instability in the vial occurs relatively fast at RT and can limit the use of 99mTc-HMPAO to only a short interval following its preparation. We studied the influence, on the radiochemical purity and stability of this 99mTc complex of different characteristics of the 0,9% NaCl used to dilute generator-produced sodium pertechnetate
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