1,377 research outputs found

    Proposal for a Universal Particle Detector Experiment

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    The Universal Particle Detector Experiment (UPDE), which consists of parallel planes of two diode laser beams of different wavelengths and a large surface metal oxide semiconductor (MOS) impact detector, is proposed. It will be used to perform real-time monitoring of contamination particles and meteoroids impacting the spacecraft surface with high resolution of time, position, direction, and velocity. The UPDE will discriminate between contaminants and meteoroids, and will determine their velocity and size distribution around the spacecraft environment. With two different color diode lasers, the contaminant and meteroid composition will also be determined based on laboratory calibration with different materials. Secondary particles dislodged from the top aluminum surface of the MOS detector will also be measured to determine the kinetic energy losses during energetic meteoroid impacts. The velocity range of this instrument is 0.1 m/s to more than 14 km/s, while its size sensitivity is from 0.2 microns to millimeter-sized particles. The particulate measurements in space of the kind proposed will be the first simultaneous multipurpose particulate experiment that includes velocities from very slow to hypervelocities, sizes from submicrometer- to pellet-sized diameters, chemical analysis of the particulate composition, and measurements of the kinetic energy losses after energetic impacts of meteroids. The experiment will provide contamination particles and orbital debris data that are critically needed for our present understanding of the space environment. The data will also be used to validate contamination and orbital debris models for predicting optimal configuration of future space sensors and for understanding their effects on sensitive surfaces such as mirrors, lenses, paints, and thermal blankets

    Isolation and characterization of antimicrobial, anti-inflammatory and chemopreventive flavones from premna odorata blanco

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    Premna odorata Blanco (Verbenaceae) is a native tree of the Philippines where its leaves are used traditionally for vaginal irrigation and tuberculosis. It is one of the seven components of a commercialized Philippine herbal preparation called "Pito-Pito". Its medicinal uses, however, have not been scientifically validated. This tree is not commonly cultivated and thrive in the less accessible limestone forests of the Philippines. Solvent partitioning and fractionation of the ethanolic crude extract of the leaves isolated two yellow amorphous powders. The identities of these compounds were determined by LC/MS/MS and NMR spectroscopic analyses, and their spectra were compared with literature data. The isolates were flavone aglycones which were the widespread acacetin and the nonwidespread diosmetin. These flavones were isolated from the P. odorata for the first time ever. They had been reported by earlier studies to exhibit medicinal properties as antimicrobial, anti-inflammatory and chemopreventive. Thus, the current study has provided a scientific evidence of the medicinal properties of the leaves of P. odorata that could become the popular basis for the plant's sustainable use, conservation and cultivation. © 2011 Academic Journals.published_or_final_versio

    Stainless steel top-seat angle beam-to-column connection: Full-scale test and analytical modelling

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    Stainless steel (SS) is increasingly used for structural applications in the construction industry as its beneficial properties outweigh initial material costs when sustainability aspects and the whole life cycle of structures are appropriately accounted for in the structural design. Despite the well-recognised significance of connections in bare metallic construction, experimental research on SS beam-to-column connections, especially full-scale test results, are scarce. This paper presents a full-scale experimental investigation on the semi-rigid behaviour of top-seat bolted connection (also known as ‘flange cleat’ connection) made from austenitic SS. Deformation characteristics of various elements of the connection were carefully investigated and subsequently used to calibrate nonlinear FE models for parametric analysis. Obtained numerical results were used to develop a four-parameter power model that relies on simplified expressions for key input parameters to predict the semi-rigid behaviour of bolted top-seat connections. Results predicted using the proposed model and those obtained using currently available techniques based on carbon steel behaviour were compared. Outcomes of the current research highlighted the significance of appropriate inclusion of stain hardening offered by austenitic grade to capture the semi-rigid response of such connections

    Geometric Semantic Grammatical Evolution

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    This is the author accepted manuscript. The final version is available from Springer via the DOI in this record.Geometric Semantic Genetic Programming (GSGP) is a novel form of Genetic Programming (GP), based on a geometric theory of evolutionary algorithms, which directly searches the semantic space of programs. In this chapter, we extend this framework to Grammatical Evolution (GE) and refer to the new method as Geometric Semantic Grammatical Evolution (GSGE). We formally derive new mutation and crossover operators for GE which are guaranteed to see a simple unimodal fitness landscape. This surprising result shows that the GE genotypephenotype mapping does not necessarily imply low genotype-fitness locality. To complement the theory, we present extensive experimental results on three standard domains (Boolean, Arithmetic and Classifier)

    Adrenal Vein Cortisol to Metanephrine Ratio for Localizing ACTH-Independent Cortisol-Producing Adenoma: A Case Report

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    Context: Finding the source of adrenocorticotropic hormone (ACTH)-independent cortisol-producing adenoma in the patients with subclinical Cushing syndrome (SCS) and bilateral adrenal nodules is sometimes challenging. Computed tomography (CT) and positron emission tomography are helpful, but adrenal venous sampling (AVS) is the gold standard approach. However, interpretation of AVS is important to improve the accuracy of decision-making for surgery. We report a case and review of the literature to assess the benefit of using adrenal vein cortisol to metanephrine ratio to determine the source of cortisol production in SCS and bilateral nodules. Evidence Acquisition: Three authors searched PubMed for data on patients with SCS who had AVS procedure and measurements of cortisol and catecholamines. Case Description: A 51-year-old woman with SCS and hypertension crisis presented to our clinic. Paraclinical investigations revealed that she had an ACTH-independent cortisol-producing adenoma and her CT scan showed bilateral adrenal nodules. After AVS, cortisol (high to low) lateralization ratio could not determine the source of cortisol production but the cortisol to metanephrine ratio localized the source to the left side, which included the larger nodule according to CT measurements. Left adrenalectomy led to clinical and paraclinical improvement. Conclusion: There is a possibility of co-secretion of other steroids accompanied with cortisol in the setting of ACTH-independent SCS. Moreover, cortisol measurement alone and interpretation of AVS results based on cortisol values may not help lateralizing the source of cortisol production with bilateral adrenal nodules. Therefore, we suggest applying cortisol to metanephrine ratio with the same gradient (gradient \u3e 2.3, highest to lowest concentration) when the source of cortisol production cannot be determined by cortisol lateralization ratio

    Accidental Prehabilitation: a case of increased exercise frequency before thoracic surgery

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    Case Diagnosis: 67 year-old man was found down with dysarthria, dysphagia, and right lower limb weakness. He was diagnosed with left anterior cerebral artery ischemic stroke, acute renal failure, atrial fibrillation, and deep venous thrombosis. He remained hospitalized for months as he did not have insurance for inpatient rehabilitation care and could not be safely discharged home. Case Description: During that time, he got physical therapy 5 times per week and then 2 times per week. While hospitalized, he was subsequently diagnosed with left upper lobe nodule from T2aN0M0 lung adenocarcinoma. Physical therapy was increased back to 5 times per week for at least two weeks prior to left upper lobectomy and mediastinal lymphadenectomy by video-assisted thorascopic surgery 2.5 months after admission. Hospital course was complicated by anticoagulation and postoperative hemothorax, which responded to evacuation. He was discharged to subacute care after rate negotiation and then home. Discussions: We present the case of a patient who got physical therapy five times weekly in the 14 days prior to thoracic surgery. Although it is well established that exercise improves aerobic parameters and outcomes, the typical outpatient insurance benefit is under 120 minutes or only twice per week. 150 minutes a week is the current recommended amount of exercise for cancer patients. Since this patient could not be discharged due to lack of insurance for acute rehabilitation or outpatient care, he remained inpatient and received physical therapy five times weekly prior to surgery. Despite risk factors, he was safely discharged and recovered well. Conclusions: Our patient got a greater frequency and higher dose of exercise than most presurgical thoracic patients; this may be why he was able to tolerate thoracic surgery with multiple serious risk factors

    Enantiomer‐selective pharmacokinetics and metabolism of ketorolac in children

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/110020/1/cptclpt1999381.pd
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