71 research outputs found

    Nuclear effects on J/{\psi} production in proton-nucleus collisions

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    The study of nuclear effects for J/{\psi} production in proton-nucleus collisions is crucial for a correct interpretation of the J/{\psi} suppression patterns experimentally observed in heavy-ion collisions. By means of three representative sets of nuclear parton distribution, the energy loss effect in the initial state and the nuclear absorption effect in the final state are taken into account in the uniform framework of the Glauber model. A leading order phenomenological analysis is performed on J/{\psi} production cross-section ratios RW/Be(xF) for the E866 experimental data. The J/{\psi} suppression is investigated quantitatively due to the different nuclear effects. It is shown that the energy loss effect with resulting in the suppression on RW/Be(xF) is more important than the nuclear effects on parton distributions in high xF region. The E866 data in the small xF keep out the nuclear gluon distribution with a large anti-shadowing effect. However, the new HERA-B measurement is not in support of the anti-shadowing effect in the nuclear gluon distribution. It is found that the J/{\psi}-nucleon inelastic cross section {\sigma} J/{\psi} abs depends on the kinematical variable xF, and increases as xF in the region xF > 0.2. 1 Introductio

    Phase Stability Effects on Hydrogen Embrittlement Resistance in Martensite–Reverted Austenite Steels

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    Earlier studies have shown that interlath austenite in martensitic steels can enhance hydrogen embrittlement (HE) resistance. However, the improvements were limited due to microcrack nucleation and growth. A novel microstructural design approach is investigated, based on enhancing austenite stability to reduce crack nucleation and growth. Our findings from mechanical tests, X-ray diffraction, and scanning electron microscopy reveal that this strategy is successful. However, the improvements are limited due to intrinsic microstructural heterogeneity effects

    Large expert-curated database for benchmarking document similarity detection in biomedical literature search

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    Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

    Thailand’S Universal Coverage Scheme And Its Impact On Health-Seeking Behavior

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    Background: Thailand’s Universal Coverage Scheme (UCS) has improved healthcare access and utilization since its initial introduction in 2002. However, a substantial proportion of beneficiaries has utilized care outside the UCS boundaries. Because low utilization may be an indication of a policy gap between people’s health needs and the services available to them, we investigated the patterns of health-seeking behavior and their social/contextual determinants among UCS beneficiaries in the year 2013. Results: The study findings from the outpatient analysis showed that the use of designated facilities for care was significantly higher in low-income, unemployed, and chronic status groups. The findings from the inpatient analysis showed that the use of designated facilities for care was significantly higher in the low-income, older, and female groups. Particularly, for the low-income group, we found that they (1) had greater health care needs, (2) received a larger number of services from designated facilities, and (3) paid the least for both inpatient and outpatient services. Conclusions: This pro-poor impact indicated that the UCS could adequately respond to beneficiaries’ needs in terms of vertical equity. However, we also found that a considerable proportion of beneficiaries utilized out-of-network services, which implied a lack of universal access to policy services from a horizontal equity point of view. Thus, the policy should continue expanding and diversifying its service benefits to strengthen horizontal equity. Particularly, private sector involvement for those who are employed as well as the increased unmet health needs of those in rural areas may be important policy priorities for that. Lastly, methodological issues such as severity adjustment and a detailed categorization of health-seeking behaviors need to be further considered for a better understanding of the policy impact

    Reliability Estimates Of Clinical Measures Between Minimum Data Set And Online Survey Certification And Reporting Data Of Us Nursing Homes

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    Background: Evidence-based quality improvement in nursing homes relies heavily on administrative data. Minimum Data Set (MDS) and Online Survey Certification and Reporting (OSCAR) are the 2 largest sources of national nursing home administrative data. Although clinical measures in each of the data systems have frequently and independently been used to measure nursing home performance, no study has systematically examined their relative reliability. Objectives: This study estimates the reliability of clinical measures between MDS and OSCAR data and discusses the utility of these databases in research. Research Design: We analyzed 4 waves of national MDS and OSCAR data (1999-2002). A comparable group of 24 clinical indicators from both datasets was selected for the reliability test. Spearman rank-order correlation analyses were used to measure the test-retest reliability relationships. Results: Across the 4 years, the majority of coefficients of clinical measures exhibit good reliability. There are 17 clinical measures (71% of the total measures) with correlation coefficients greater than 0.4, the minimally acceptable reliability threshold according to Morris. The highest correlation coefficients were associated with tube feeding at 0.883. Conclusions: Our findings indicate that the target clinical measures in OSCAR and MDS are generally consistent and reliable. However, researchers should use OSCAR self-reported clinical measures to measure nursing home outcomes in place of corresponding MDS clinical measures with caution because some indicators in the administrative data are more reliable than others
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