The Experts below are selected from a list of 500025 Experts worldwide ranked by ideXlab platform
Yasuaki Maeda - One of the best experts on this subject based on the ideXlab platform.
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aspects of ultrasonically assisted transesterification of various vegetable oils with methanol
Ultrasonics Sonochemistry, 2007Co-Authors: Carmen Stavarache, M Vinatoru, Yasuaki MaedaAbstract:The batch transesterification of vegetable oil with methanol, in the presence of potassium hydroxide as catalyst, by means of low frequency Ultrasound (40 kHz) was studied with the aim of gaining more knowledge on intimate reaction mechanism. The concentration of fatty acid methyl esters, of mono-, di- and triglycerides of the actual reaction mixture were determined at short reaction time by HPLC. The effect of Ultrasounds on the lipids transesterification correlated with triglyceride structures is discussed. It was found that under ultrasonic activation the rate-determining reaction switches from DG → MG (classical mechanic agitation) to MG + ROH → Gly + ME (ultrasonically driven transesterification).
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fatty acids methyl esters from vegetable oil by means of ultrasonic energy
Ultrasonics Sonochemistry, 2005Co-Authors: Carmen Stavarache, M Vinatoru, Rokuro Nishimura, Yasuaki MaedaAbstract:The transesterification of vegetable oil with short-chain alcohols, in the presence of base-catalyst, by means of low frequency Ultrasound (28 and 40 kHz) in order to obtain biodiesel fuel was studied. By using Ultrasounds the reaction time is much shorter (10-40 min) than for mechanical stirring. The quantity of required catalyst is 2 or 3 times lower. The molar ratio of alcohol/oil used is only 6:1. Normal chain alcohols react fast, while secondary and tertiary alcohols show some or no conversion after 60 min of reaction. Surprisingly, 40 kHz Ultrasounds are much more effective in the reduction of the reaction time (10-20 min). Twenty eight kilohertz give slightly better yields (98-99%), but longer reaction time, while higher frequencies are not useful at all for the transesterification of fatty acids.
Mary Ann Thomas - One of the best experts on this subject based on the ideXlab platform.
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prenatal diagnosis of monosomy 1p36 a focus on brain abnormalities and a review of the literature
American Journal of Medical Genetics Part A, 2008Co-Authors: Philippe M. Campeau, Katherine L Mackay, Lola Cartier, Mary Ann Thomas, Vazken Der M Kaloustian, Lisa G. ShafferAbstract:Monosomy 1p36 is an increasingly recognized chromosomal anomaly. We describe two patients with monosomy 1p36 who had brain abnormalities detected on prenatal Ultrasound. The first patient was ascertained prenatally with Ultrasound abnormalities, including ventriculomegaly, a single umbilical artery, a unilateral club foot, a ventricular septal defect, and intra-uterine growth retardation. Amniocentesis showed a normal karyotype. A postnatal MRI showed moderate to severe non-obstructive hydrocephalus, bilateral colpocephaly, and abnormal myelination of the anterior limb of the internal capsule. A postnatal karyotype demonstrated a deletion of 1p36.3 that was not detected prenatally due to low resolution. Molecular studies by array comparative genome hybridization (CGH) identified a terminal deletion of ∼10 Mb. Our second patient was a fetus who had brain abnormalities suggestive of holoprosencephaly identified on prenatal Ultrasound. Amniocentesis showed 46,XX,der(1)t(1;20)(p36.1;p12.2), that was found to be maternally inherited. Fetal autopsy demonstrated hydrocephalus, focal polymicrogyria, and cerebellar hypoplasia. However, holoprosencephaly was not confirmed. In addition to describing two patients with monosomy 1p36 who had abnormal brain anatomy on prenatal Ultrasounds, we review the literature of other prenatally detected patients with monosomy 1p36 and review brain abnormalities seen both prenatally and postnatally. © 2008 Wiley-Liss, Inc.
David Muyodi - One of the best experts on this subject based on the ideXlab platform.
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web based quality assurance process drives improvements in obstetric Ultrasound in 5 low and middle income countries
Global health science and practice, 2016Co-Authors: Jonathan O Swanson, David Plotner, Holly L Franklin, David L Swanson, Victor Lokomba Bolamba, Adrien Lokangaka, Irma Sayury Pineda, Lester Figueroa, Ana Garces, David MuyodiAbstract:High quality is important in medical imaging, yet in many geographic areas, highly skilled sonographers are in short supply. Advances in Internet capacity along with the development of reliable portable Ultrasounds have created an opportunity to provide centralized remote quality assurance (QA) for Ultrasound exams performed at rural sites worldwide. We sought to harness these advances by developing a web-based tool to facilitate QA activities for newly trained sonographers who were taking part in a cluster randomized trial investigating the role of limited obstetric Ultrasound to improve pregnancy outcomes in 5 low- and middle-income countries. We were challenged by connectivity issues, by country-specific needs for website usability, and by the overall need for a high-throughput system. After systematically addressing these needs, the resulting QA website helped drive Ultrasound quality improvement across all 5 countries. It now offers the potential for adoption by future Ultrasound- or imaging-based global health initiatives.
Carmen Stavarache - One of the best experts on this subject based on the ideXlab platform.
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aspects of ultrasonically assisted transesterification of various vegetable oils with methanol
Ultrasonics Sonochemistry, 2007Co-Authors: Carmen Stavarache, M Vinatoru, Yasuaki MaedaAbstract:The batch transesterification of vegetable oil with methanol, in the presence of potassium hydroxide as catalyst, by means of low frequency Ultrasound (40 kHz) was studied with the aim of gaining more knowledge on intimate reaction mechanism. The concentration of fatty acid methyl esters, of mono-, di- and triglycerides of the actual reaction mixture were determined at short reaction time by HPLC. The effect of Ultrasounds on the lipids transesterification correlated with triglyceride structures is discussed. It was found that under ultrasonic activation the rate-determining reaction switches from DG → MG (classical mechanic agitation) to MG + ROH → Gly + ME (ultrasonically driven transesterification).
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fatty acids methyl esters from vegetable oil by means of ultrasonic energy
Ultrasonics Sonochemistry, 2005Co-Authors: Carmen Stavarache, M Vinatoru, Rokuro Nishimura, Yasuaki MaedaAbstract:The transesterification of vegetable oil with short-chain alcohols, in the presence of base-catalyst, by means of low frequency Ultrasound (28 and 40 kHz) in order to obtain biodiesel fuel was studied. By using Ultrasounds the reaction time is much shorter (10-40 min) than for mechanical stirring. The quantity of required catalyst is 2 or 3 times lower. The molar ratio of alcohol/oil used is only 6:1. Normal chain alcohols react fast, while secondary and tertiary alcohols show some or no conversion after 60 min of reaction. Surprisingly, 40 kHz Ultrasounds are much more effective in the reduction of the reaction time (10-20 min). Twenty eight kilohertz give slightly better yields (98-99%), but longer reaction time, while higher frequencies are not useful at all for the transesterification of fatty acids.
Nicole A Cipriani - One of the best experts on this subject based on the ideXlab platform.
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thyroid nodule size at Ultrasound as a predictor of malignancy and final pathologic size
Thyroid, 2017Co-Authors: Allison Cavallo, Daniel N Johnson, Michael G White, Saaduddin Siddiqui, Tatjana Antic, Melvy Sarah Mathew, Raymon H Grogan, Peter Angelos, Edwin L Kaplan, Nicole A CiprianiAbstract:Background: Thyroid-related mortality has remained constant despite the increasing incidence of thyroid carcinoma. Most thyroid nodules are benign; therefore, Ultrasound and fine needle aspiration (FNA) are integral in cancer screening. We hypothesize that increased nodule size at Ultrasound does not predict malignancy and correlation between nodule size at Ultrasound and pathologic exam is good. Methods: Resected thyroids with preoperative Ultrasounds were identified. Nodule size at Ultrasound, FNA diagnosis by Bethesda category, size at pathologic examination, and final histologic diagnosis were recorded. Nodule characteristics at Ultrasound and FNA diagnoses were correlated with gross characteristics and histologic diagnoses. Nodules for which correlation could not be established were excluded. Results: Of 1003 nodules from 659 patients, 26% were malignant. Nodules <2 cm had the highest malignancy rate (∼30%). Risk was similar (∼20%) for nodules ≥2 cm. Of the 548 subject to FNA, 38% were malignant. Dec...
