177,549 research outputs found
Magnitude and Kinetics of Decrease in Liver Stiffness After Anti-viral Therapy in Patients With Chronic Hepatitis C: A Systematic Review and Meta-analysis
No full textAppropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
Assessment of selenium levels and risk factors for stroke and other cardiovascular disease: a cross sectional study in a seleniferous area of Punjab, India
No full textBackground and aims: Rural areas of Punjab in India have been found to have soil rich in selenium (Se); about 2160 hectare area is seleniferous and is populated by about 10,000 inhabitants. Selenium concentrations in these villages were reported to be as high as 65 times over non-seleniferous areas. The aim of this cross-sectional study was to evaluate selenium levels in blood, hair and nails in a group of subjects living in this area, and to evaluate the correlation between selenium exposure levels and a relevant cardiovascular risk factor and blood pressure.
Methods: In a random sample of rural residents in three districts of a seleniferous area of Punjab, we determined selenium concentration in hair, nail clippings and serum samples. Analyses were carried out using atomic absorption spectrophotometry at National Dairy Research Institute (NDRI), Karnal, India. Data analysis was performed using the STATA 15.0 software (STATA Corp. TX).
Results: A total of 680 human subjects were recruited in this study, with a male/female ratio of 0.65 and a median age of 43 (IQR 32-52). Medium selenium levels in blood, hair and nail were 86.7 μg/l (IQR 55.9-200.3), 20.7 μg/g (IQR 12.6-40.3) and 56.9 μg/g (IQR 42.8-83.9), respectively, with lower levels in women in all three kind of samples. Concerning systolic blood pressure, Pearson’s correlation coefficients were 0.102 (95 % CI -0.025 to 0.226, p=0.116); 0.076 (95% CI -0.010 to 0.160, p=0.085); 0.072 (95% CI -0.015 to 0.157, p=0.104) with blood, hair and nail, respectively. For diastolic blood pressure, Pearson’s correlation coefficients are 0.106 (95% CI -0.022 to 0.230, p=0.104), 0.036 (95% CI -0.050 to 0.122, p=0.409), 0.049 (95% CI -0.038 to 0.135, p=0.272), respectively.
Conclusions: Our findings indicate a positive correlation between selenium content in blood, hair and nails and increasing systolic and diastolic pressure levels, in line with previous epidemiologic findings, indicating a possible health concern for this highly exposed population. The possible relation between selenium over-exposure and onset of hypertension and other cardiovascular diseases deserves further investigation
Exposure to a high selenium environment in Punjab, India: Biomarkers and health conditions
No full textSeleniferous areas have been identified and described in many parts of the world. Despite the interest in selenium as a trace element of considerable toxicologic and nutritional relevance, however, only a few studies have been carried out on human health effects of such high selenium environments. We collected blood, hair and nail samples from 680 adult volunteers (267 men and 413 women) living in seven villages located in the seleniferous area of Punjab, India. We measured selenium levels in these specimens. We also administered a questionnaire to collect information about diet and other lifestyle characteristics, to identify the sources of selenium exposure and to correlate it with a number of health conditions. Serum and hair selenium contents were highly correlated, while the association of these biomarkers with nail selenium content was weaker. Serum selenium showed limited association with consumption of locally produced foods, while pulses and vegetables, along with cereals and pulses, were associated to higher hair and nail selenium contents, respectively. Association of a number of adverse health endpoints with serum and hair selenium was stronger than for nail selenium contents. Such endpoints included higher prevalence of nausea and vomiting, bad breath, worm infestation, breathlessness exert and bad breath, chest pain, hair and nail abnormalities and loss, garlic odor, edema, spontaneous abortion, and overall selenosis. In contrast, we gathered no evidence of dermatitis or loss of appetite in residents most exposed to selenium. Overall, and despite some statistical imprecision in effect estimates, these results confirm the occurrence of adverse health effects in subjects exposed to high levels of environmental selenium. Nail selenium contents may be less adequate to reflect and monitor such overexposure, compared with blood and hair levels
sj-jpg-4-tag-10.1177_17562848221098243 – Supplemental material for Changes in the gut microbiome associated with liver stiffness improvement in nonalcoholic steatohepatitis
No full textSupplemental material, sj-jpg-4-tag-10.1177_17562848221098243 for Changes in the gut microbiome associated with liver stiffness improvement in nonalcoholic steatohepatitis by Suzanne R. Sharpton, Ondrej Podlaha, Jen-Chieh Chuang, Yevgeniy Gindin, Robert P. Myers and Rohit Loomba in Therapeutic Advances in Gastroenterology</p
sj-jpg-1-tag-10.1177_17562848221098243 – Supplemental material for Changes in the gut microbiome associated with liver stiffness improvement in nonalcoholic steatohepatitis
No full textSupplemental material, sj-jpg-1-tag-10.1177_17562848221098243 for Changes in the gut microbiome associated with liver stiffness improvement in nonalcoholic steatohepatitis by Suzanne R. Sharpton, Ondrej Podlaha, Jen-Chieh Chuang, Yevgeniy Gindin, Robert P. Myers and Rohit Loomba in Therapeutic Advances in Gastroenterology</p
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
sj-jpg-2-tag-10.1177_17562848221098243 – Supplemental material for Changes in the gut microbiome associated with liver stiffness improvement in nonalcoholic steatohepatitis
No full textSupplemental material, sj-jpg-2-tag-10.1177_17562848221098243 for Changes in the gut microbiome associated with liver stiffness improvement in nonalcoholic steatohepatitis by Suzanne R. Sharpton, Ondrej Podlaha, Jen-Chieh Chuang, Yevgeniy Gindin, Robert P. Myers and Rohit Loomba in Therapeutic Advances in Gastroenterology</p
sj-jpg-3-tag-10.1177_17562848221098243 – Supplemental material for Changes in the gut microbiome associated with liver stiffness improvement in nonalcoholic steatohepatitis
No full textSupplemental material, sj-jpg-3-tag-10.1177_17562848221098243 for Changes in the gut microbiome associated with liver stiffness improvement in nonalcoholic steatohepatitis by Suzanne R. Sharpton, Ondrej Podlaha, Jen-Chieh Chuang, Yevgeniy Gindin, Robert P. Myers and Rohit Loomba in Therapeutic Advances in Gastroenterology</p
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