A surname-based bibliometric indicator: publications in biomedical journal

Surnames have been used as a proxy in studies on health care for various ethnic groups and also applied to ascribe ethnicity in studies on the genetic structure of a population. The aim of this study was to use a surname-based bibliometric indicator to assess the representation of Jewish authors in US biomedical journals. The other aim was to test the hypothesis that the representation of Jewish authors in US biomedical journals corresponds to their representation among US Nobel Prize winners in Medicine, 1960–2009. From among articles published 1960–2009 in all journals covered by Medline (>5,000), and in the top 10 US biomedical journals we counted articles by authors from the following three groups: Kohenic–Levitic surnames, other common Jewish surnames, and the most frequent non-Jewish surnames in the USA. The frequency of a surname in the US population (1990 US Census) was used to calculate the expected number of scientific publications: the total number of published articles multiplied by a surname’s frequency. The actual number of articles with that surname was also determined. The ratio of actual to expected number of articles was used as a measure of representation proportionality. It was found that the ratio of actual to expected number of articles in both Jewish groups is close to 10 among all (>5,000) journals, and close to 20 in the top 10 journals. The ratio of actual to expected numbers of Jewish Nobel Laureates in the USA is also close to 20. In conclusion, the representation of Jewish authors in top 10 US biomedical journals corresponds to the representation of Jewish Nobel Laureates among US laureates. We hypothesize that disproportional representation of Jewish scientists as authors in top biomedical journals and among Nobel Prize laureates in Medicine is mostly due to their overrepresentation as research participants, not because of the increased chances for reward for a Jewish researcher per se.     

Biomedical research productivity and economic crisis in Greece: a 22-year study

This article aims to study the effect of the current financial crisis (2010–2017) on biomedical productivity and impact of Greece-affiliated investigators. PubMed, Scopus and Web of Science were searched for articles published in biomedical journals with at least one Greek affiliation during the period 1995–2016 (date of last search October 19, 2017). The impact of Greek articles was the citations received by published articles during the first 2 years following the year of publication adjusted to the number of Greek and global articles. A discrepancy in the absolute article productivity between the databases was observed: a mean annual increase before the crisis was observed in all databases, while after the crisis the increase persisted in PubMed, in Scopus a decline was observed and in the Web of Science a smaller increase was observed. The changes in relative productivity were similar for both study periods in all databases (increasing before and decreasing after crisis, p?<?0.001 for trend in both periods). A continuous increase in total citations in both periods was observed (mean 2347?±?1622 before and 2627?±?3374 after the crisis). A continuous increase in the impact indices following adjustment for Greek (mean annual increase 0.27?±?0.30 before to 0.37?±?0.62 during the crisis, p?=?0.58) and global productivity (mean annual increase from 0.0024?±?0.0018 to 0.0007?±?0.004, p?=?0.95) was observed throughout the study period. In conclusion, the decline observed in the relative productivity of Greek affiliated articles during crisis compared to the period before was not reflected in their impact.     

Comparative analysis of the factors associated with citation and media coverage of clinical research

Our objective was to study the relationship between the design and content of randomized clinical trials (RCTs) and the subsequent number of citations in the medical literature and attention in online news and social media. We studied RCTs published during 2014 in five highly cited medical journals. This was a retrospective review focusing on characteristics of the individual trials and measures of citation and lay media attention. Primary outcome measures included citation count and Altmetric^® scores (a composite score measuring attention in news, blogs, Twitter^®, and Facebook^®). Two hundred and forty two RCTs were included in the final analysis. Trial characteristics that were positive predictors of citation count included investigation of Hepatitis C treatment (r = 0.35, p < 0.001), private funding (r = 0.24, p < 0.001), mortality-related endpoint (r = 0.22, p < 0.001), and research setting within the United States (r = 0.13, p < 0.001). The trial characteristic that positively predicted Altmetric score was the population size potentially affected (r = 0.39, p < 0.001). The only negative predictor of citation count was the size of the population potentially affected (r = ?0.21, p < 0.001). Negative predictors of the Altmetric score included investigation of Hepatitis C treatment (r = ?0.21, p < 0.001) and private funding (r = ?0.13, p < 0.001). While correlation magnitudes were weak, the predictors of biomedical literature citation and non-academic media coverage were different. These predictors may affect editorial decisions and, given the rising influence of health journalism, further study is warranted.     

Mapping farm animal welfare research in an enlarged Europe: international collaboration,bibliometric output,research resources and relation to economic indices

Against the background of divergent political developments across Europe, farm animal welfare (FAW) science has evolved during the last three decades as an inter-disciplinary research area. Recent achievements include pan-European research projects and the implementation of animal welfare assessment systems on-farm. The aim of this study was mapping activities for FAW science and investigating geographical differences in FAW research in Europe (EU28 + candidate countries and the European Economic Area) with regard to available resources (e.g. human resources, infrastructure, funding) and research output (e.g. collaborations and publications). Further, we enquired if economic attributes such as the Coefficient of National Innovation Capacity (NIC) were associated with the reported available resources and research output factors (publications and collaborations) of FAW research. Based on questionnaires sent out to a wide researcher network in regions of an enlarged Europe, we found differences with regard to ‘input factors’ such as human resources, animal and laboratory facilities and national and international research funding and ‘output factors’ such as inter/national collaboration, participation in EU-funded projects related to FAW and number of publications. Respondents were allocated to 4 Western and 4 Eastern geographical clusters of countries (‘hubs’). There were a larger number of researchers, students and technical staff per laboratory in Western compared to Eastern hubs. A pronounced difference was found for funding, as 35% of respondents in the Eastern hubs stated that they lack funded FAW projects compared to 4% in the West. In general, respondents from the Western hubs stated significantly more often that they run projects in the field of FAW research (p = 0.034). Furthermore they were significantly more involved in EU-funded schemes, such as FP7 (EU’s Research and Innovation Funding Programme for 2007–2013) with 24% (p = 0.013) and in ERA-NET Cofund projects (European Research Area—Coordination of Research Programmes) with 5.7% (p = 0.042). The average sum of impact factors from 5 self-named citations was 3.0 ± 2.8 (mean, SD) in the Eastern hubs and 7.5 ± 4.4 in the Western Hubs. When investigating associations of the economic status of EU countries with resource factors and achievements in FAW research, the ‘Coefficient of National Innovation Capacity (NIC)’ was moderately correlated with the input factors for FAW research such as the average number of PhDs currently employed in the institutions (r _s = 0.66; p < 0.001) and the total number of employed researchers (r _s = 0.56; p < 0.01). Stronger associations were found between the scientific output and the economic ranking, here represented by the cumulative impact factor of their published papers (r _s = 0.74; p < 0.001), and between the number of EC-project reports published in CORDIS 2015 with NIC (r _s = 0.67; p < 0.001). We conclude that due to economic disadvantages as represented by the lower NIC or rare participation in EU-funding schemes, the Eastern Hubs could not reach the same level of output factors as the Western Hubs, which negatively impacts on the number of young researchers (PhDs) and impact factors, thus resulting in lower visibility and influence.     

Online distribution channel increases article usage on Mendeley: a randomized controlled trial

Prior research shows that article reader counts (i.e. saves) on the online reference manager, Mendeley, correlate to future citations. There are currently no evidenced-based distribution strategies that have been shown to increase article saves on Mendeley. We conducted a 4-week randomized controlled trial to examine how promotion of article links in a novel online cross-publisher distribution channel (TrendMD) affect article saves on Mendeley. Four hundred articles published in the Journal of Medical Internet Research were randomized to either the TrendMD arm (n = 200) or the control arm (n = 200) of the study. Our primary outcome compares the 4-week mean Mendeley saves of articles randomized to TrendMD versus control. Articles randomized to TrendMD showed a 77% increase in article saves on Mendeley relative to control. The difference in mean Mendeley saves for TrendMD articles versus control was 2.7, 95% CI (2.63, 2.77), and statistically significant (p < 0.01). There was a positive correlation between pageviews driven by TrendMD and article saves on Mendeley (Spearman’s rho r = 0.60). This is the first randomized controlled trial to show how an online cross-publisher distribution channel (TrendMD) enhances article saves on Mendeley. While replication and further study are needed, these data suggest that cross-publisher article recommendations via TrendMD may enhance citations of scholarly articles.     

The effect of characteristics of title on citation rates of articles

This study aimed to assess the association between some features of articles title and number of citations in a volume of Addictive Behavior journal. All research articles published in the volume number 32 (2007) in the Addictive Behaviors journal (n = 302) were analyzed by two independent authors. For each article, the following information has been extracted: number of citations up to June 2013 in the Scopus citation database, type of and characteristics of titles, having different words in the keywords, reference to place and presence of an acronym. The summary statistics showed that mean number of citation was 16.36 ± 19.55 times. Articles with combinational title (use of a hyphen or a colon separating different ideas within a sentence) and articles with different words in the keywords (at least two different keywords) had higher number of citations. The number of citations was not correlated with the number of words in the title (r = 0.05, P = 0.325). Our results suggested that some features in the paper such as type of the title and articles with keywords different from words included in the title can help to predict the number of citation counts. These findings can be used by authors and reviewers in order to maximize the impact of articles. The length of title is not associated with citation counts. Therefore, the guide for authors of journals can be more flexible regarding the length of the title.     

Comparison of imaging methods used for dental implant osseous integration assessment

Two different imaging techniques used to determine bone tissue response to dental implants were compared. Dental implants were implanted into the maxillae of 18 pigs, which were sacrificed after 4, 8 and 12 weeks. Implants with surrounding bone tissue were retrieved for methyl methacrylate histology and contact radiography. On identical sections peri-implant bone density and bone implant contact (BIC) ratio were assessed with two different imaging methods. Evaluation of Giemsa eosin stained and contact radiographed sections showed direct osseous integration for all implants and both methods showed a strong correlation with correlation coefficient r = 0.930 (P < 0.0001) for peri-implant bone density and r = 0.817 (P < 0.0001) for bone implant contact ratio. While the two imaging methods showed moderate differences for peri-implant bone density there were significant differences between the BIC values determined. In general, contact radiography tends to underestimate BIC for approximately 4.5 % (P = 0.00003).     

Internal migration of scientists in Russia and the USA: the case of physicists

To assess endocrinologic and metabolic research productivity in East Asia (i.e., China, Japan, and South Korea) and correlations between socioeconomic factors and endocrinologic and metabolic research productivity. Articles (except editorials, conference abstracts, letters, news, and corrections) published in 134 endocrinology and metabolism journals in 2005–2014 were screened with the Web of Science database. Total and annual numbers of articles, study designs, impact factors, citations, and articles in high-impact-factor journals were determined for China, Japan, and South Korea. Annual numbers of articles were related to socioeconomic factors for each country. In 2005–2014, there were 144,660 articles from East Asia published in endocrinology and metabolism journals: 10,190, 9470, and 3124 from Japan, China, and South Korea, respectively. Japan published the most randomized controlled trials, followed by China and South Korea, respectively. China had the most articles in high-impact-factor journals, followed by Japan and South Korea, respectively. South Korea had the highest average impact factor and number of citations. During the period studied, annual numbers of articles from China and South Korea increased remarkably (P < 0.05) but remained stable for Japan. Annual numbers of articles from China and South Korea were positively correlated with gross domestic product and expenditure on health care (P < 0.05). The increase in endocrinology and metabolism articles during 2005–2014 in China and South Korea was associated with improved socioeconomic conditions. China has made progress in scientific publication in the past decade; however, there is still room for improvement.     

Trend and impact of international collaboration in clinical medicine papers published in Malaysia

Research collaboration is the way forward in order to improve quality and impact of its research findings. International research collaboration has resulted in international co-authorship in scientific communications and publications. This study highlights the collaborating research and authorship trend in clinical medicine in Malaysia from 2001 to 2010. Malaysian-based author affiliation in the Web of Science (Science Citation Index Expanded) and clinical medicine journals (n = 999) and articles (n = 3951) as of 30th Oct 2011 were downloaded. Types of document analyzed were articles and reviews, and impact factors (IF) in the 2010 Journal Citation Report Science Edition were taken to access the quality of the articles. The number of publications in clinical medicine increased from 4.5 % (n = 178) in 2001 to 23.9 % (n = 944) in 2010. The top three contributors in the subject categories are Pharmacology and Pharmacy (13.9 %), General and Internal Medicine (13.6 %) and Tropical Medicine (7.3 %). By journal tier system: Tier 1 (18.7 %, n = 738), Tier 2 (22.5 %, n = 888), Tier 3 (29.6 %, n = 1170), Tier 4 (27.2 %, n = 1074), and journals without IF (2.1 %, n = 81). University of Malaya was the most productive. Local collaborators accounted for 60.3 % and international collaborations 39.7 %. Articles with international collaborations appeared in journals with higher journal IFs than those without international collaboration. They were also cited more significantly than articles without international collaborations. Citations, impact factor and journal tiers were significantly associated with international collaboration in Malaysia’s clinical medicine publications. Malaysia has achieved a significant number of ISI publications in clinical medicine participation in international collaboration.     

Low awareness of the link between science and innovation affects public policies in developing countries: The Chilean case

Developing countries share disbelief about the benefits of the endogenous production of science as a tool for economical growth. Hence, public policies to strengthen science and technology and promote the culture of innovation are, in general, weak and sometimes incoherent. Patenting has become not only an icon to protect discoveries which can yield profits and enable socio-economical growth but also a potent informetric tool to assess innovation and certainly, since the seminal work of Narin, to understand the multidimensional interactions between science, technology and innovation. In this article we examine the impact of Chilean research articles on world technology as viewed by the link between articles produced in Chile and US patents. Our results show that from 1987 to 2003, 509 US patents had 562 citations to 273 articles produced at least, by one author working in a Chilean institution. US, not Chilean companies are the holders of patents citing Chilean produced articles. The research articles covered many disciplines but a clear concentration occurred in the biomedical field. Additionally, chemistry was also well cited. Our results confirm that in Chile a non-patenting culture which involves researchers and institutions still prevails. Hence, public policies need to be designed and implemented to foster scientific production and innovation in order to advance progress in the current knowledge-economy-driven society which sustains competitiveness in the globalized world.     

Shock compression of Cu<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>Zr<Subscript>100−<Emphasis Type="Italic">x</Emphasis></Subscript> metallic glasses from molecular dynamics simulations

The shock response of Cu _x Zr_100?x (x = 30, 50 and 70) metallic glasses (MGs) is characterized using large-scale molecular dynamics simulations. A wide range of piston velocities U _p = 0.125–2.5 km/s are simulated corresponding to shock pressures from 3 to 130 GPa. Independent of composition, the metallic glasses exhibit the following shock wave propagation regimes: (1) single elastic shock wave for U _p < 0.25 km/s, (2) split elastic and plastic shock waves for 0.25 < U _p < 0.75 km/s and (3) overdriven plastic shock wave with a narrow elastic precursor for U _p > 0.75 km/s. Within the split wave and overdriven regimes, the amplitude of the elastic precursor increases with increasing shock intensity, thereby indicating a pressure-dependent yield criterion. Hugoniot states are strongly dependent on the Cu content of the MG with Cu₇₀Zr₃₀ exhibiting a much higher resistance to plastic deformation than either Cu₅₀Zr₅₀ or Cu₃₀Zr₇₀.     

Can a bibliometric indicator predict the success of an analgesic?

In the assessment of success of new analgesic drugs over the past 50 years (Kissin, Anesth Analg 110:780–789, 2010) we observed a difference in the publication response to a new drug between biomedical journals in general and top journals: number of published articles on a drug increased (and declined) more rapidly in the top journals. Based on this phenomenon we present a new publication indicator—the Top Journal Selectivity Index (TJSI). It represents the ratio between the number of all types of articles in the top 20 biomedical journals and the number of articles in all (>5,000) journals covered by Medline, over 5 years after a drug’s introduction. Ten analgesics developed during the period 1986–2009 were selected for analysis. Three publication indices were used for assessment: the number of all types of articles presented in Medline, the number of articles covering only randomized controlled trials (RCT), and the Top Journal Selectivity Index. We also assessed the success score in the development of these analgesics based on the following criteria: novelty of molecular target, analgesic efficacy, and response by the pharmaceutical market. The relationships between the publication indices and analgesic’s success score were determined with the use of the Pearson correlation coefficient. Positive relationship was found only with the Top Journal Selectivity Index (r = 0.876, p < 0.001). We suggest that this index can predict success in drug development at least in the field of analgesics.     

International comparative study on nanofiltration membrane technology based on relevant publications and patents

This study adopts a bibliometric approach to quantitatively assess current research trends in nanofiltration membrane technology (NFM), a new membrane separation technology widely used in various fields. It analyses scientific papers published between 1988–2011 in all journals contained in the Science Citation Index and patent data with the same time span from the Derwent patent database. The study examines developments in basic NFM research and technological innovations. Over the past 24 years, there has been a notable growth in publication outputs. Compared with other countries, China exhibited a rapid growth, particularly from 2000–2011, with its total number of papers ranking second only to the United States (US). Chinese NFM papers focus on energy and agriculture, while the US focuses on biochemistry and molecular biology. China holds the most global NFM patents, with rapid growth in patent numbers from 2005–2011. China, the US and Japan together hold 78 % of the total global NFM patents and have a strong technological advantage in water treatment and separation technology. Although there are four Chinese institutions in the top 10 patentee list, most are application patents that focus on the integrated application of existing nanofiltration membrane. In contrast the patents owned by foreign patentees are mostly research patents involving technology innovations of the nanofiltration membrane itself. Therefore, NFM research capacity in China should be further strengthened to maximize the advantages gained via research to date.     

Predicting author h-index using characteristics of the co-author network

The objective of this work was to test the relationship between characteristics of an author’s network of coauthors to identify which enhance the h-index. We randomly selected a sample of 238 authors from the Web of Science, calculated their h-index as well as the h-index of all co-authors from their h-index articles, and calculated an adjacency matrix where the relation between co-authors is the number of articles they published together. Our model was highly predictive of the variability in the h-index (R ² = 0.69). Most of the variance was explained by number of co-authors. Other significant variables were those associated with highly productive co-authors. Contrary to our hypothesis, network structure as measured by components was not predictive. This analysis suggests that the highest h-index will be achieved by working with many co-authors, at least some with high h-indexes themselves. Little improvement in h-index is to be gained by structuring a co-author network to maintain separate research communities.     

Effect of stents coated with a combination of sirolimus and alpha-lipoic acid in a porcine coronary restenosis model

The aim of this study was to evaluate antiproliferative sirolimus- and antioxidative alpha-lipoic acid (ALA)-eluting stents using biodegradable polymer [poly-l-lactic acid (PLA)] in a porcine coronary overstretch restenosis model. Forty coronary arteries of 20 pigs were randomized into four groups in which the coronary arteries had a bare metal stent (BMS, n = 10), ALA-eluting stent with PLA (AES, n = 10), sirolimus-eluting stent with PLA (SES, n = 10), or sirolimus- and ALA-eluting stent with PLA (SAS, n = 10). A histopathological analysis was performed 28 days after the stenting. The ALA and sirolimus released slowly over 30 days. There were no significant differences between groups in the injury or inflammation score; however, there were significant differences in the percent area of stenosis (56.2 ± 11.78 % in BMS vs. 51.5 ± 12.20 % in AES vs. 34.7 ± 7.23 % in SES vs. 28.7 ± 7.30 % in SAS, P < 0.0001) and fibrin score [1.0 (range 1.0–1.0) in BMS vs. 1.0 (range 1.0–1.0) in AES vs. 2.0 (range 2.0–2.0) in SES vs. 2.0 (range 2.0–2.0) in SAS, P < 0.0001] between the four groups. The percent area of stenosis based on micro-computed tomography corresponded with the restenosis rates based on histopathological stenosis in different proportions in the four groups (54.8 ± 7.88 % in BMS vs. 50.4 ± 14.87 % in AES vs. 34.5 ± 7.22 % in SES vs. 28.9 ± 7.22 % in SAS, P < 0.05). SAS showed a better neointimal inhibitory effect than BMS, AES, and SES at 1 month after stenting in a porcine coronary restenosis model. Therefore, SAS with PLA can be a useful drug combination for coronary stent coating to suppress neointimal hyperplasia.     

Gender differences in compensation in academic medicine: the results from four neurological specialties within the University of California Healthcare System

This study demonstrates the continued existence of gender disparity with respect to salary in four neurologic specialties in the largest public healthcare system of the Western United States without the bias of self-report. We extracted physician salary information from the publicly available UC pay system database and obtained Scopus (http://www.scopus.com/home.url) and Web of Science publication counts and h-indices via searching individual faculty by name and specialty. Faculty gender, institution, specialty, ranking, chairmanship, degrees, and salary data were collected through review of departmental websites and individual faculty profiles. All faculty members (n = 433) from the departments of ophthalmology, otolaryngology, neurosurgery and neurology in the UC pay system database in 2008 were selected for analysis. We found that female faculty members in the 2008 UC healthcare system were significantly underrepresented from the highest salary brackets, representing only 12.5 and 2.6 % of those earning $300,001–$400,000 and over $400,000, respectively (p < 0.01). The female-to-male salary ratio in 2008 for all UC physicians earning over $100,000 was 0.698 (p < 0.00001). Multivariate regression modeling demonstrated a 12 % salary deficit (95 % CI 2–21 %, p = 0.02) for women in the UC healthcare system after controlling for institution, professorial rank, chairmanship, specialty, Scopus publication count, and Scopus h-index. Despite recent efforts at educational equality in the training of physicians, gender disparities still persist within academic medicine.     

Meta-analysis in psychology: a bibliometric study

Meta-analysis refers to the statistical methods used in research synthesis for combining and integrating results from individual studies. The present study draws on the strengths of bibliometric methods in order to offer an overview of meta-analytic research activity in psychology, as well as to characterize its most important aspects and their evolution over time. A total of 2,874 articles published in scientific journals were identified and standard bibliometric indicators (e.g., number of articles, productivity by country, and national and international collaborations) and laws (e.g., Price’s and Lotka’s law) were applied to these data. The results suggest a clear upward trend not only in the number of articles published since the 1970s (with a peak of productivity in 2010), but also in both the number of authors by article ( $ \bar{x} = 2. 7 5 $ , SD = 1.53) and internationalization, especially since the 1990s. The interest in meta-analysis extends to many authors (n = 5,445), countries (n = 44) and scientific journals (n = 394), as well as to several areas of psychology that mostly fit a growing exponential model. In future studies it would be interesting to explore the citing behaviour and patterns in the meta-analysis literature.     

The top-cited research works in the Science Citation Index Expanded

This study aimed to identify and analyze the characteristics of the top-cited articles published in the Science Citation Index Expanded from 1991 to 2010. Articles that have been cited more than 1,000 times since publication to 2010 were assessed regarding their distribution in indexed journals and categories of the Web of Science. Five bibliometric indicators were used to evaluate source institutions and countries. A new indicator, the Y-index, is proposed to assess publication quantity and the character of contribution to articles. We identify 3,652 top-cited articles with 71 % originating from US. The fourteen most productive institutions were all located in US. Science, Nature, New England Journal of Medicine, and Cell hosted the most cited publications. In addition, the Y-index was successfully applied to evaluate the publication character of authors, institutions, and countries.     

Acoustic Emission by Quartz Tuning Forks and Other Oscillating Structures in Cryogenic 4He Fluids

We report on experimental investigations of acoustic emission by quartz tuning forks resonating at frequencies 32 kHz, 38 kHz, 77 kHz and 100 kHz immersed in cold gaseous ⁴He and its normal and superfluid liquid phases. Frequency dependence of the observed low-drive-linewidth at 350 mK together with the temperature and pressure dependences (1.3 K < T < 4.2 K, 0 < p < 25 bar) of the observed damping of the high frequency (77 and 100 kHz) resonators measured in normal liquid ⁴He and its superfluid phase provide strong and direct evidence of the importance of sound emission by these tuning forks. Three analytical models of acoustic emission by vibrating tuning forks are developed and compared with the experimental results. We also discuss the importance of sound emission for experiments with the commonly used 32 kHz tuning forks as well as other oscillating structures??spheres, wires, grids and various micromachined sensors. We compare the relative importance of dissipative losses due to laminar viscous/ballistic drag and acoustic emission in liquid and superfluid ⁴He.