254 research outputs found

    A lightweight electronically commutated dc motor for electric passenger vehicles

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    A functional model breadboard converter and a rare-earth-cobalt, permanent magnet motor; as well as an engineering model converter and PM motor suitable for vehicle installations were developed and tested. The converter and motor achieved an 88% peak efficiency, a maximum output of 26 kW at 26,000 rpm, and a continuous rating of 15 kW. The system also generated power to the source during braking, with a demonstrated peak power available at the converter terminals of approximately 26 kW at 88% efficiency. Major conclusions include: (1) the SAE J227a(D) driving cycle efficiency for the converter/motor is 86% to 88% when energy available for recovery at the converter terminals is included; (2) the converter initial cost is approximately five times that of the permanent magnet motor, but can be reduced by means of LSI logic and integrated liquid cooled semiconductor packages; and (3) an electronically commutated motor with a liquid cooled converter will operate reliably without service or maintenance for the life of a passenger vehicle

    Time-resolved two-photon spectroscopy of photosystem I determines hidden carotenoid dark-state dynamics

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    We present time-resolved fs two-photon pump-probe data measured with photosystem I (PS I) of Thermosynechococcus elongatus. Two-photon excitation (λexc/2) 575 nm) in the spectral region of the optically forbidden first excited singlet state of the carotenoids, Car S1, gives rise to a 800 fs and a 9 ps decay component of the Car S1f Sn excited-state absorption with an amplitude of about 47 ( 16 % and 53 ( 10%, respectively. By measuring a solution of pure "-carotene under exactly the same conditions, only a 9 ps decay component can be observed. Exciting PS I at exactly the same spectral region via one-photon excitation (λexc) 575 nm) also does not show any sub-ps component. We ascribe the observed constant of 800 fs to a portion of about 47 ( 16 % "-carotene states that can potentially transfer their energy efficiently to chlorophyll pigments via the optically dark Car S1 state. We compared these data with conventional one-photon pump-probe data, exciting the optically allowed second excited state, Car S2. This comparison demonstrates that the fast dynamics of the optically forbidden state can hardly be unravelled via conventional one-photon excitation only because the corresponding Car S1 populations are too small after Car S2 f Car S1 internal conversion. A direct comparison of the amplitudes of the Car S1 f Sn excited-state absorption of PS I and "-carotene observed after Car S2 excitation allows determination of a quantum yield for the Car S1 formation in PS I of 44 ( 5%. In conclusion, an overall Car S2f Chl energy-transfer efficiency of∌69 ( 5 % is observed at room temperature with 56 ( 5 % being transferred via Car S2 and probably very hot Car S1 states and 13 ( 5 % being transferred via hot and “cold ” Car S1 states

    Selected tools to visualize membrane interactions

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    In the past decade, we developed various fluorescence-based methods for monitoring membrane fusion, membrane docking, distances between membranes, and membrane curvature. These tools were mainly developed using liposomes as model systems, which allows for the dissection of specific interactions mediated by, for example, fusion proteins. Here, we provide an overview of these methods, including two-photon fluorescence cross-correlation spectroscopy and intramembrane Förster energy transfer, with asymmetric labelling of inner and outer membrane leaflets and the calibrated use of transmembrane energy transfer to determine membrane distances below 10 nm. We discuss their application range and their limitations using examples from our work on protein-mediated vesicle docking and fusion

    Toxaphene and Other Organochlorines in Arctic Ocean Fauna: Evidence for Atmospheric Delivery

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    Residues of the insecticide toxaphene (polychlorinated camphenes, PCCs) and other organochlorines (OCs) were determined in air, snow, seawater, zooplankton, and benthic amphipods collected from an ice island in the Canadian Arctic. The simultaneous determination of OCs in the atmospheric, hydrologic, and biologic compartments provided evidence of an atmospheric link to polar food chains. PCCs were identified and quantified using capillary gas chromatography - negative ion mass spectrometry. The order of OCs abundance in arctic air was: hexachlorocyclohexanes (HCHs) > hexachlorobenzene > PCCs > polychlorinated biphenyls (PCBs) > chlordanes > DDTs. In seawater, PCCs were exceeded only by the HCHs. Concentrations of PCBs and PCCs in two samples of benthic amphipods were the highest of the OCs detected.Key words: Arctic, Canada, pollution, organochlorines, air, water, biotaMots clés: Arctique, Canada, pollution, organochlorés, air, eau, biot

    Syndrome Keratitis-Ichtyosis-Deafness (KID) chez un enfant togolais issu d’un mariage consanguin

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    Le syndrome KID est une affection génétique rare associant kératite, ichtyose et surdité. Nous rapportons un cas dont la surdité s'est compliquée de mutisme chez un enfant togolais issu d'un mariage consanguin.Il s'agissait d'une fillette de 9 ans admise en dermatologie pour une peau sÚche et une kératodermie palmoplantaire évoluant depuis l'enfance, une surdité sévÚre et un mutisme total évoluant depuis la naissance. Il n'y avait pas d'histoire familiale connue de syndrome KID. Les parents de cet enfant sont des cousins germains. A l'examen, on notait une kératodermie palmoplantaire typique en cuir grossier, une peau sÚche ichtyosiforme finement squameuse avec un aspect pachydermique aux genoux et un aspect arlequin aux jambes. L'examen ophtalmologique avait noté une blépharo-conjonctivite, une xérophtalmie, une photophobie et une absence de sourcils. L'examen ORL avait objectivé une hypotrophie des pavillons des oreilles, une surdité sévÚre et un mutisme total. La particularité de cette observation réside dans la sévérité de l'atteinte auditive qui s'est compliquée de mutisme. Notre enfant étant née de parents consanguins sains, sans histoire familiale de KID, nous pensons que le mode de transmission est probablement sporadique. Une étude moléculaire du cas index et de ses parents, non réalisée à cause de notre plateau technique limité aurait pu le confirmer

    Relationship between a Weighted Multi-Gene Algorithm and Blood Pressure Control in Hypertension

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    Hypertension (HTN) is a complex disease with interactions among multiple organ systems, including the heart, vasculature, and kidney with a strong heritable component. Despite the multifactorial nature of HTN, no clinical guidelines utilize a multi-gene approach to guide blood pressure (BP) therapy. Non-smokers with a family history of HTN were included in the analysis (n = 384; age = 61.0 ± 0.9, 11% non-white). A total of 17 functional genotypes were weighted according to the previous effect size in the literature and entered into an algorithm. Pharmacotherapy was ranked from 1⁻4 as most to least likely to respond based on the algorithmic assessment of individual patient's genotypes. Three-years of data were assessed at six-month intervals for BP and medication history. There was no difference in BP at diagnosis between groups matching the top drug recommendation using the multi-gene weighted algorithm (n = 92) vs. those who did not match (n = 292). However, from diagnosis to nadir, patients who matched the primary recommendation had a significantly greater drop in BP when compared to patients who did not. Further, the difference between diagnosis to current 1-year average BP was lower in the group that matched the top recommendation. These data suggest an association between a weighted multi-gene algorithm on the BP response to pharmacotherapy.Geneticure Inc.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

    Primary Malignant Musculosqueletal Tumors of Members in Adult in Togo

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    Abstract Purpose: Primary malignant musculosqueletal tumors in adult are rare affections group and its treatment is still a real challenge today. The aim of this work was to describe the epidemiologic and treatment aspects of these tumors in the national reference center of our country. Materiel and Methods: It was a retrospective review of primary malignant musculosqueletal tumors treated in orthopedics and trauma unit of Sylvanus Olympio teaching hospital of Lomé, Togo from January 2000 to December 2014. Results: During the study period, 28 cases were selected and reviewed. There were 17 men (60.71%) and 11 women (39.29%). The average age was 32.7 years. There were 20 cases (71%) of primary malignant bone tumors (PMBT) and 8 cases (29%) of primary malignant soft tissues tumors (PMSTT). There were 6 (30%) of osteosarcoma. The tumor was located in the bones of the forearm and wrist/hand in 2 (10%) patients for each anatomical site; for the lower limb, around knee in 7 (35%) patients. Eight patients had PMSTT (28, 57%). There were three cases of rhabdomyosarcoma, 2 cases of fibrosarcoma. Tumors were located around knee in 4 cases and around ankle/foot in 3 cases. In the two groups of tumor, tumor resection was performed in 5 patients (17.86%) and limb amputation indicated in 23 patients (82.14%), was performed in 15 (53.57%) and 8 patients (37.78%), rejected it and left hospital against medical advice. Conclusion: Malignant musculoskeletal tumors are relatively rare in Togo. Their treatment is based on radical surgery which is often not supervised by adjuvant therapies. Ignorance, poverty of the population and embryonic state of diagnostic and treatment infrastructures are the obstacles to their care. Education and awareness must be integrated to care and fight against this group of diseases

    Ketogenic diet as a glycine lowering therapy in nonketotic hyperglycinemia and impact on brain glycine levels

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    BACKGROUND: Nonketotic hyperglycinemia (NKH) is a severe neurometabolic disorder characterized by increased glycine levels. Current glycine reduction therapy uses high doses of sodium benzoate. The ketogenic diet (KD) may represent an alternative method of glycine reduction. AIM: We aimed to assess clinical and biochemical effects of two glycine reduction strategies: high dose benzoate versus KD with low dose benzoate. METHODS: Six infants with NKH were first treated with high dose benzoate therapy to achieve target plasma glycine levels, and then switched to KD with low dose benzoate. They were evaluated as clinically indicated by physical examination, electroencephalogram, plasma and cerebral spinal fluid amino acid levels. Brain glycine levels were monitored by magnetic resonance spectroscopy (MRS). RESULTS: Average plasma glycine levels were significantly lower with KD compared to benzoate monotherapy by on average 28%. Two infants underwent comparative assessments of brain glycine levels via serial MRS. A 30% reduction of brain glycine levels was observed in the basal ganglia and a 50% reduction in the white matter, which remained elevated above normal, and was equivalent between the KD and high dose benzoate therapies. CSF analysis obtained while participants remained on the KD showed a decrease in glycine, serine and threonine levels, reflecting their gluconeogenetic usage. Clinically, half the patients had seizure reduction on KD, otherwise the clinical impact was variable. CONCLUSION: KD is an effective glycine reduction method in NKH, and may provide a more consistent reduction in plasma glycine levels than high-dose benzoate therapy. Both high-dose benzoate therapy and KD equally reduced but did not normalize brain glycine levels even in the setting of low-normal plasma glycine
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