57 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

    Clinical experience with recombinant human thyrotrophin (rhTSH) in the management of patients with differentiated thyroid cancer

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    The purpose of this work was to gain clinical experience with and to identify the optimal conditions for the use of recombinant human TSH (rhTSH, commercially available as Thyrogen) in the management of patients with differentiated thyroid cancer (DTC). The study involved 22 patients for a total of 27 administration cycles of rhTSH, for either diagnostic (in 19 instances) and/or therapeutic purposes (in 8 instances). There were 19 patients with papillary cancer (follicular variant in 4, columnar variant in 1) and 3 patients with follicular cancer (1 Hurtle cell variant). All patients had previously undergone total thyroidectomy and 1-5 cycles of 131I-therapy. Thyrogen was administered i.m. according to the suggested protocol: 0.9 mg i.m. on days 1 and 2, radioiodine on day 3. Peak serum TSH levels between 68-237 microIU/mL were observed after rhTSH administration; these were on average 65% higher, on a patient-by-patient basis, than peak serum TSH observed after conventional withdrawal of thyroxine treatment in 19 patients, while in 3 patients they were 28% lower, but still in the potent stimulation range (86-94 microIU/mL). There was general agreement between imaging results obtained under rhTSH stimulation and those obtained on prior occasions during thyroxine withdrawal, although radioiodine uptake was interpreted as less intense following Thyrogen administration. Of 18 patients undergoing rhTSH administration for diagnostic purposes, 11 patients had a negative radioiodine whole-body scan (WBS) and 7 had a positive WBS. Three of the WBS-negative patients were shown to be actually affected by tumor recurrence, respectively by PET with [18F]FDG (in 2 cases) and by post-131I therapy scan. Serum thyroglobulin (hTg) increased to abnormal levels following rhTSH stimulation in 3/7 of the WBS-positive patients as well as in 1/11 WBS-negative patients. In 3/7 WBS-positive as well as in 3/11 WBS-negative patients, serum hTg progressively rose under rhTSH stimulation, yet still remaining below 3 ng/mL. Post-131I therapy scans following Thyrogen administration showed good radioiodine uptake in 7/8 patients, the single unsuccessful case being most likely due to expansion of the iodine pool because of recent use of an iodinated contrast medium. The overall results show the feasibility and practical advantages of employing rhTSH stimulation in the general clinical setting rather than thyroxine withdrawal in the management of DTC patients. Caution should be raised on the interpretation of the serum hTg response to such potent but short-lived TSH stimulation

    Applied multi-criteria ideal rehabilitation model for budget allocation across road infrastructure

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    The solution of prioritization problem for budget allocation across road infrastructure rehabilitation projects is highly complicated. This complexity is often due to the contradictions exist in budget allocation process. Such process concerns allocation of rehabilitation funds across various road infrastructures and taking into account multiple evaluation criteria. Therefore, budget allocation is a complex process with too many contradictions in form of criteria or attributes. According to the Systematic Innovation methodology, solving a problem means removing a contradiction. This paper presents a decision support approach for management of budget in rehabilitation process of road infrastructure, introducing Applied Multi-Criteria Ideal Rehabilitation Model. To achieve this, with the help of multi-criteria decision analysis, the Degree of Ideality is introduced as a function of all criteria. "Ideality" is the measure of how close the system is to the ideal final result. If the useful feature improves or harmful feature lessens, the ideality improves. In order to maximize the Degree of Ideality in the proposed Model, contradictions and resources are identified and ideal final result is introduced. This will result in a simple mechanism for allocation of budget across all the road infrastructures need to be rehabilitated

    Direct relationship between cell density and FDG uptake in asymptomatic aortic aneurysm close to surgical threshold: an in vivo and in vitro study.

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    ABSTRACT: Purpose: Conflicting results have been reported about the clinical value of fluorodeoxyglucose (FDG) imaging in predicting the risk of rupture of abdominal aortic aneurysm (AAA). The present study tests the hypothesis that FDG uptake is low in asymptomatic noninflammatory AAA due to the low cell density in aneurysmal walls. Methods: Positron emission tomography (PET)/CT imaging was performed in 12 consecutive candidates for AAA surgical repair and in 12 age- and sex-matched controls. At intervention, aneurysmal walls were cut into three sequential blocks. Block A was frozen to cut three 5-\ub5m slices for incubation with 2-3 MBq of FDG for 5 min. Block C was first incubated with the same tracer solution for the same time and subsequently frozen to cut three 5-\ub5m slices. Autoradiographic images were coregistered with immunohistochemical pictures of cell density, type and DNA synthesis as assessed on block B. Results: No visible uptake in abdominal aorta occurred in any patient or control subject. Immunohistochemistry documented a severe loss of wall structure, with low numbers of cells. Tracer retention directly correlated with overall cell density and with prevalence of cells synthesizing DNA. The metabolic nature of FDG uptake was confirmed by the selective effect of preliminary freezing that decreased tracer content by 90% in regions with high cell density and only by 34% in cold acellular areas. Conclusion: The loss of tissue structure and the marked decrease in cell density account for the low prevalence of positive findings at FDG PET imaging, at least in asymptomatic patients bearing AAAs whose diameter is close to surgical indication

    Predicted distribution of the Sunda clouded leopard Neofelis diardi (Mammalia: Carnivora: Felidae) on Borneo

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    The Sunda clouded leopard Neofelis diardi is a medium sized (15–25 kg) cat, found only on the Sundaic islands of Borneo and Sumatra. In recent years intensive camera-trapping surveys in Borneo have begun to shed light on the habitat associations and basic ecology of this elusive wild cat, but its distribution on an island-wide scale remains very poorly known. Such information is an essential element in the assessment of the Sunda clouded leopard’s conservation status and in the development of conservation action. In this paper we use MaxEnt niche distribution modelling to make predictions regarding the current distribution of this cat on Borneo. We collected a total of 259 occurrence records for the Sunda clouded leopard, stemming from all Bornean regions apart from Brunei and South Kalimantan, of which 48 (Balanced Model) or 94 (Spatial Filtering Model) were used in our modelling. Our habitat suitability model suggests that this species has a widespread distribution over a large contiguous portion of Borneo. The only exception is South Kalimantan, which is predicted largely to comprise unsuitable habitat. The predicted distribution closely follows the current distribution of little-encroached forest on Borneo (including selectively logged and unlogged areas). The species is notably predicted to be absent from the extensive areas of oil palm plantation, particularly in much of the low-lying coastal land. The predicted range encompasses a large proportion of the existing and proposed protected area network on Borneo. We highlight the priority areas for the conservation of the Sunda clouded leopard in Borneo based on our predicted distribution

    Predicted distribution of the Sunda clouded leopard Neofelis diardi (Mammalia: Carnivora: Felidae) on Borneo

    No full text
    The Sunda clouded leopard Neofelis diardi is a medium sized (15–25 kg) cat, found only on the Sundaic islands of Borneo and Sumatra. In recent years intensive camera-trapping surveys in Borneo have begun to shed light on the habitat associations and basic ecology of this elusive wild cat, but its distribution on an island-wide scale remains very poorly known. Such information is an essential element in the assessment of the Sunda clouded leopard’s conservation status and in the development of conservation action. In this paper we use MaxEnt niche distribution modelling to make predictions regarding the current distribution of this cat on Borneo. We collected a total of 259 occurrence records for the Sunda clouded leopard, stemming from all Bornean regions apart from Brunei and South Kalimantan, of which 48 (Balanced Model) or 94 (Spatial Filtering Model) were used in our modelling. Our habitat suitability model suggests that this species has a widespread distribution over a large contiguous portion of Borneo. The only exception is South Kalimantan, which is predicted largely to comprise unsuitable habitat. The predicted distribution closely follows the current distribution of little-encroached forest on Borneo (including selectively logged and unlogged areas). The species is notably predicted to be absent from the extensive areas of oil palm plantation, particularly in much of the low-lying coastal land. The predicted range encompasses a large proportion of the existing and proposed protected area network on Borneo. We highlight the priority areas for the conservation of the Sunda clouded leopard in Borneo based on our predicted distribution
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