9,522 research outputs found

    Method for Synthesizing Bulk Ceramics and Structures from Polymeric Ceramic Precursors

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    A method and product made by using a liquid polymeric ceramic precursor to synthesize dense, crack-free bulk ceramics in a technique using a sacrificial mold provides a ceramic structure for many technical, medical and industrial applications. The novel process uses an open cell material as a sacrificial mold to shape a liquid ceramic precursor during curing. The cured ceramic green body can be machined and shaped to form the desired ceramic structure prior to final pyrolysis. The open cell material forms gas release paths to release large amount of gases generated during the pyrolysis of the cured ceramic precursor. After pyrolysis, an intact, dense, crack-free ceramic structure with high purity, strength and durability is obtained. Uses of the present invention include, but are not limited to, bulk ceramic parts, ceramic crucibles, a replacement material in some applications involving glass, silicon carbides, silicon nitrides, hafnium carbide and the like

    Talk on the Block: Using public forum sentiment to predict housing prices

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    This paper develops a textual analysis methodology to quantify sentiment on public market forums to predict outcomes in the real estate market. This paper draws inspiration from Soo (2018) which quantified sentiment through real estate news media. We believe that analyzing public forums allows us to understand public sentiment in its most unedited, casual form; whereas real estate news media is limited to perspectives and interpretations of an editor. Antweiler and Frank (2004) showed that public forums are significant when predicting stock market outcomes, lending validity to our text source. Our methodology includes identifying a relevant dictionary of positive and negative words, scraping BiggerPockets real estate forums, running a textual sentiment analysis, and finally regressing against fundamental housing market indicators in 34 large metropolitan statistical areas (MSAs) to assess sentiment’s predictability on home prices. Our regression results suggest that sentiment significance varies more in the short-run with public forum text than it does with news media because news media is “marked-to-market daily.” Marking-to-market is the practice of valuing securities, or portfolios of securities, at their current market value, as opposed to a book value. Because news media is updated every day, and sometimes more than once a day, we find that it is capturing current market home values much more quickly than forum sentiment. Additionally, we conclude that discussion on real estate public forums can predict housing prices in the long-run, suggesting that the users are engaging in conversation that is targeting long-term investments and trying to make sense of the potential future value of a home that they are considering buying and/or selling

    Treatment exhaustion of highly active antiretroviral therapy (HAART) among individuals infected with HIV in the United Kingdon: multicentre cohort study

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    Objectives: To investigate whether there is evidence that an increasing proportion of HIV infected patients is starting to experience increases in viral load and decreases in CD4 cell count that are consistent with exhaustion of available treatment options. Design: Multicentre cohort study. Setting: Six large HIV treatment centres in southeast England. Participants: All individuals seen for care between 1 January 1996 and 31 December 2002. Main outcome measures: Exposure to individual antiretroviral drugs and drug classes, CD4 count, plasma HIV RNA burden. Results: Information is available on 16 593 individuals (13 378 (80.6%) male patients, 10 340 (62.3%) infected via homosexual or bisexual sex, 4426 (26.7%) infected via heterosexual sex, median age 34 years). Overall, 10 207 of the 16 593 patients (61.5%) have been exposed to any antiretroviral therapy. This proportion increased from 41.2% of patients under follow up at the end of 1996 to 71.3% of those under follow up in 2002. The median CD4 count and HIV RNA burden of patients under follow up in each year changed from 270 cells/mm3 and 4.34 log10 copies/ml in 1996 to 408 cells/mm3 and 1.89 log10 copies/ml, respectively, in 2002. By 2002, 3060 (38%) of patients who had ever been treated with antiretroviral therapy had experienced all three main classes. Of these, around one quarter had evidence of “viral load failure” with all these three classes. Patients with three class failure were more likely to have an HIV RNA burden > 2.7 log10 copies/ml and a CD4 count < 200 cells/mm3. Conclusions: The proportion of individuals with HIV infection in the United Kingdom who have been treated has increased gradually over time. A substantial proportion of these patients seem to be in danger of exhausting their options for antiretroviral treatment. New drugs with low toxicity, which are not associated with cross resistance to existing drugs, are urgently needed for such patients

    Transfer information remotely via noise entangled coherent channels

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    In this contribution, a generalized protocol of quantum teleportation is suggested to investigate the possibility of remotely transfer unknown multiparities entangled coherent state. A theoretical technique is introduced to generate maximum entangled coherent states which are used as quantum channels. We show that the mean photon number plays a central role on the fidelity of the transferred information. The noise parameter can be considered as a control parameter only for small values of the mean photon number

    Observation of a Distribution of Internal Transverse Magnetic Fields in a Mn12-Based Single Molecule Magnet

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    A distribution of internal transverse magnetic fields has been observed in single molecule magnet (SMM) Mn12-BrAc in the pure magnetic quantum tunneling (MQT) regime. Magnetic relaxation experiments at 0.4 K are used to produce a hole in the distribution of transverse fields whose angle and depth depend on the orientation and amplitude of an applied transverse ``digging field.'' The presence of such transverse magnetic fields can explain the main features of resonant MQT in this material, including the tunneling rates, the form of the relaxation and the absence of tunneling selection rules. We propose a model in which the transverse fields originate from a distribution of tilts of the molecular magnetic easy axes.Comment: 4 page

    Evaluation of preferences of women and healthcare professionals in Singapore for implementation of noninvasive prenatal testing for Down syndrome

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    INTRODUCTION: Invasive prenatal diagnosis (IPD) has long been used to prenatally diagnose Down syndrome (DS), but is associated with a small risk of miscarriage. Meanwhile, noninvasive prenatal testing (NIPT) is a highly sensitive screening test using cell-free DNA in maternal blood for detection of DS that removes the risk of miscarriage, but confers a small risk of false-positive and false-negative results. Their implementations into clinical practice require an understanding of stakeholder preferences. METHODS: A total of 69 health professionals (HPs) and 301 women took part in a discrete choice experiment (DCE) in which preferences for four prenatal test attributes (accuracy, time of results, risk of miscarriage and amount of information provided) were assessed, and conditional logit regression was used to analyse data. Data on demographics and ranked preferences for test attributes were collected, and a direct choice between NIPT, IPD or neither test was given. RESULTS: Women showed a preference for test safety, whereas HPs prioritised test accuracy above all other attributes. When offered a direct choice between NIPT, IPD or neither test, women aged over 35 years, those with previous miscarriage or who knew a child with DS were more likely to choose NIPT than IPD. Chinese women preferred NIPT whereas Indian women preferred IPD. CONCLUSION: Our data highlight the need for patient-specific counselling, taking into account previous experiences and cultural factors. Since women and HPs prioritise different test attributes, it is essential that HPs recognise these differences in order to provide non-biased counselling

    Tris(morpholinium) hexa-μ3-hydroxido-hexa-μ2-oxido-dodeca­oxidohexa­molybdenum(VI)chromate(III) tetra­hydrate

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    In the title organic–inorganic hybrid compound, (C4H10NO)3[H6CrMo6O24]·4H2O, the Anderson-type [H6CrMo6O24]3− polyoxoanion is centrosymmetric, with the CrIII ion lying on an inversion center. One of the two crystallographiclly independent morpholinium cations is half-occupied. Inter­molecular N—H⋯O and O—H⋯O hydrogen bonds link the cations, polyoxoanions and uncoordinated water mol­ecules

    Associations between reliable changes in depression and changes in BMI, total body fatness and visceral adiposity during a 12-month weight loss trial.

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    We investigated associations between changes in depression and body composition over a 12-month weight loss trial. Of the 298 adults (BMI &gt; 27 m/kg2), 219 with complete depression and body composition data were included. A 10-item Center for Epidemiologic Studies Depression Scale measured depression; dual-energy X-ray absorptiometry measured body composition. Multinomial logistic regression predicted reliable changes in depression by BMI, body fat (BF) and visceral adiposity (VAT). Multiplicative interaction terms tested modification by sex and ethnicity. Participants with increases in body composition were less likely to experience improvements in depression (BMI: RRR = 0.79 (0.68-0.91), p &lt; 0.01; BF: RRR = 0.97 (0.94 - 0.99), p = 0.01; VAT: RRR = 0.99 (0.98-1.00), p = 0.02), but not worsening of depression (BMI: RRR = 1.29 (0.96-1.73), p = 0.10; BF: RRR = 1.04 (0.99-1.09), p = 0.15; VAT: RRR = 1.01 (1.00-1.03), p = 0.18). Sex and ethnicity interaction terms were not significant. However, the relationship was only significant among females, among non-Latinos for BMI and BF, and among Latinos for VAT. Our study supports the association between depression and obesity and highlights the need for longitudinal studies investigating VAT and depression in diverse ethnic groups

    Children's Medicines in Tanzania: A National Survey of Administration Practices and Preferences.

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    The dearth of age-appropriate formulations of many medicines for children poses a major challenge to pediatric therapeutic practice, adherence, and health care delivery worldwide. We provide information on current administration practices of pediatric medicines and describe key stakeholder preferences for new formulation characteristics. We surveyed children aged 6-12 years, parents/caregivers over age 18 with children under age 12, and healthcare workers in 10 regions of Tanzania to determine current pediatric medicine prescription and administration practices as well as preferences for new formulations. Analyses were stratified by setting, pediatric age group, parent/caregiver education, and healthcare worker cadre. Complete data were available for 206 children, 202 parents/caregivers, and 202 healthcare workers. Swallowing oral solid dosage forms whole or crushing/dissolving them and mixing with water were the two most frequently reported methods of administration. Children frequently reported disliking medication taste, and many had vomited doses. Healthcare workers reported medicine availability most significantly influences prescribing practices. Most parents/caregivers and children prefer sweet-tasting medicine. Parents/caregivers and healthcare workers prefer oral liquid dosage forms for young children, and had similar thresholds for the maximum number of oral solid dosage forms children at different ages can take. There are many impediments to acceptable and accurate administration of medicines to children. Current practices are associated with poor tolerability and the potential for under- or over-dosing. Children, parents/caregivers, and healthcare workers in Tanzania have clear preferences for tastes and formulations, which should inform the development, manufacturing, and marketing of pediatric medications for resource-limited settings
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