1,855 research outputs found

    trans-4-(1-Naphth­yl)-2-oxo-1,3-oxazolidine-5-carboxylic acid

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    The crystal structure of the title compound, C14H11NO4, is influenced by N—H⋯O and O—H⋯O hydrogen bonds, linking mol­ecules into one-dimensional tapes running along the [010] direction

    Barrier Inhomogeneity of Schottky Diode on Nonpolar AlN Grown by Physical Vapor Transport

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    An aluminum nitride (AlN) Schottky barrier diode (SBD) was fabricated on a nonpolar AlN crystal grown on tungsten substrate by physical vapor transport. The Ni/Au-AlN SBD features a low ideality factor n of 3.3 and an effective Schottky barrier height (SBH) of 1.05 eV at room temperature. The ideality factor n decreases and the effective SBH increases at high temperatures. The temperature dependences of n and SBH were explained using an inhomogeneous model. A mean SBH of 2.105 eV was obtained for the Ni-AlN Schottky junction from the inhomogeneity analysis of the current-voltage characteristics. An equation in which the parameters have explicit physical meanings in thermionic emission theory is proposed to describe the current-voltage characteristics of inhomogeneous SBDs.Comment: 6 pages, 6 figure

    Accumulation Pattern of Flavonoids in Cabernet Sauvignon Grapes Grown in a Low-Latitude and High-Altitude Region

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    Particular climate conditions in a low-latitude and high-altitude region endow grape berries with distinctivequality characteristics. So far, few reports have been concerned with the formation of berry flavour in such aregion. This study aimed to investigate the accumulation pattern of flavonoids in Vitis vinifera L. cv. CabernetSauvignon grape berries growing at different altitudes of the highland in southwest China in two consecutivevintages. In addition to the 3-O-monoglucosides and 3-O-acyl monoglucosides of the five main anthocyanidins(delphinidin, cyanidin, peonidin, petunidin and malvidin), some uncommon anthocyanins, such as threediglucosides of anthocyanidins and pelargonidin-3-O-glucoside, were detected in the grape berries. Higheraltitude cultivation greatly promoted the production of anthocyanins and flavonols, particularly cyanidintypeanthocyanins and quercetin-type flavonols from the F3’H branch of the flavonoid biosynthetic pathway.Flavan-3-ols from both branches were comparatively less influenced by vineyard altitude. Vintage in thishigh-altitude region also had a dramatic influence on the accumulation of flavonoids. Most of the anthocyaninand flavonol components were affected more by vineyard altitude than by vintage, whereas the accumulationof flavan-3-ols differed mainly between vintages. The present data will not only improve the understandingof flavonoid accumulation in grapes from a high-altitude region with different climates, but also providepractical guidance for the production of high-quality grapes and wine

    Factors related to children’s caries: a structural equation modeling approach

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    BACKGROUND: Dental caries among preschool children is highly prevalent in many less-developed countries. METHODS: A model which explored the factors related to children’s dental caries was tested in this study using structural equation modeling. Caregivers of children aged 5 years were surveyed on their socioeconomic status, and their oral health knowledge, attitudes and practices. In addition, information on their children’s oral health practices, dental insurance and dental service utilization were collected. Examination of caries was conducted on all children who returned fully completed questionnaires. RESULTS: The results showed that socioeconomic factors influenced children’s oral health practices through the impact of caregivers’ oral health knowledge and practices; that caregivers’ oral health knowledge affected children’s oral health practices through the influence of caregivers’ oral health attitudes and practices; and finally, that children’s oral health practices were linked directly to their caries. CONCLUSION: The findings have important applications for promoting policies aimed at advancing children’s oral health

    A giant hemolymphangioma of the pancreas in a 20-year-old girl: a report of one case and review of the literature

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    <p>Abstract</p> <p>Background</p> <p>Hemolymphangioma of the pancreas is a very rare benign tumor. There were only six reports of this disease until December 2008. Herein, we report a case of giant hemolymphangioma of the pancreas in a 20-year-old girl.</p> <p>Case presentation</p> <p>We describe a 20-year-old girl who presented with a mass in abdominal cavity and epigastric discomfort about a week. Physical examination showed a great abdominal mass. Abdominal computed tomography showed extrinsic duodenal compression due to a large retroperitoneal tumor possibly arising from pancreas. The tumor enucleation was performed and a diagnosis of hemolymphangioma of the pancreas was made. The patient had a complication of chylous leakage, which was successfully managed. The patient is alive and well, after 26 months of follow-up, with no complaints or recurrence.</p> <p>Conclusion</p> <p>From this case and literature, we can conclude that hemolymphangioma of the pancreas in adult is a rare benign tumor, and accurate diagnosis can not be preoperatively established. Tumor resection should be performed whenever possible. The risk of recurrence seems very low.</p

    Imidazolium 3-nitro­benzoate

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    In the title compound, C3H5N2 +·C7H4NO4 −, the benzene ring forms a dihedral angle of 40.60 (5)° with the imidizolium ring. The nitro­benzoate anion is approximately planar: the benzene ring makes dihedral angles of 3.8 (3) and 3.2 (1)° with the nitro and carboxyl­ate groups, respectively. In the crystal structure, the cations and anions are linked by inter­molecular N—H⋯O hydrogen bonds, forming a zigzag chain along the b axis

    Dual-energy computed tomography iodine uptake in differential diagnosis of inflammatory and malignant pulmonary nodules

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    PURPOSEThe aim of this study was to evaluate the diagnostic performance of iodine uptake parameters using dual-energy computed tomography (DECT) in discriminating inflammatory nodules from malignant tumors.METHODSThis retrospective study included 116 solid pulmonary nodules from 112 patients who were admitted to our hospital between January and September 2018. All nodules were confirmed by surgery or puncture. The degree of enhancement of a single-section region of interest was evaluated. After total tumor volume-of-interest segmentation, the mean iodine density of the whole tumor was measured. Meanwhile, iodine uptake parameters, including total iodine uptake volume, total iodine concentration, vital iodine uptake volume, and vital iodine concentration, were calculated, and a predictive model was established. The overall ability to discriminate between inflammatory and malignant nodules was analyzed using an independent samples t-test for normally distributed variables. The diagnostic accuracy and prognostic performance of DECT parameters were evaluated and compared using receiver operating characteristic curve analysis and logistic regression analysis. A multivariate logistic regression analysis was used to determine the prognostic factors and goodness-of-fit of the whole tumor mean iodine and iodine uptake parameters for discriminating malignant nodules.RESULTSThere were 116 non-calcified nodules, including 64 inflammatory nodules and 52 malignant nodules. The degree of enhancement in malignant nodules was significantly lower than that in inflammatory nodules (P=.043). All iodine uptake parameters in malignant nodules were significantly higher than those in inflammatory nodules (P < .001). The area under the receiver operating curve value, accuracy, sensitivity, and specificity of the established model based on iodine uptake parameters were 0.803, 76.72%, 82.69%, and 84.37%, respectively, which exhibited better diagnostic performance than the degree of enhancement on weighted average images with respective values of 0.609, 59.48%, 61.54%, and 59.38%.CONCLUSIONThe iodine uptake parameters of DECT exhibited better diagnostic accuracy in discriminating inflammatory nodules from malignant nodules than the degree of enhancement on weighted average images
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