bims-evares Biomed News
on Evaluation of research
Issue of 2020‒05‒24
twenty-one papers selected by
Thomas Krichel
Open Library Society


  1. J Endod. 2020 May 14. pii: S0099-2399(20)30306-X. [Epub ahead of print]
    Ahmad P, Mohamed Elgamal HA.
      INTRODUCTION: Bibliometric analysis is the quantitative measure of the impact of a scientific article in its respective field of research. The aim of this study was to identify and analyze the main features of the top 50 most-cited articles published in Journal of Endodontics since its inception as well as the top 50 most downloaded articles in 2017 and 2018 in order to evaluate the changing trends and other bibliometric parameters of the contemporary literature as compared to the classic literature.METHODS: An electronic search was conducted on the Clarivate Analytics' Web of Science (WoS) "All Databases to identify and analyze the top 50 most frequently cited scientific papers. After ranking the articles in a descending order based on their citation counts, each article was then cross matched with the citation counts in Scopus, Google Scholar and PubMed.
    RESULTS: The citation counts of the 50 selected most-cited articles ranged between 218 and 731 (WoS). The years in which most top 50 articles were published were 2004 and 2008 (n=5). Among 131 authors, the greatest contribution was made by Torabinejad M (n=14). Most of the articles originated from the United States (n=38) with the greatest contributions from the School of Dentistry, Loma Linda University, USA (n=15). Basic research-technology was the most frequent study design (n=18). A negative, significant correlation occurred between citation density and publication age (correlation coefficient = -0.708, p < 0.01).
    CONCLUSIONS: Several interesting differences were found between the main characteristics of the most-cited articles and the most downloaded articles.
    Keywords:  Bibliometric analysis; citation classics; most downloaded papers
    DOI:  https://doi.org/10.1016/j.joen.2020.04.014
  2. Rev Med Inst Mex Seguro Soc. 2020 Jan 01. pii: http://revistamedica.imss.gob.mx/editorial/index.php/revista_medica/article/view/1582/3743. [Epub ahead of print]58(1): 37-49
    Robles-Silva L, García-Barragán TL, Ramírez-Contreras MG.
      The aim of this review is to describe the development of the aging and public health field in Mexico, in order to identify its trends, its main authors and their impact, based on the scientific production generated between the 1970s and 2000s decades. 166 articles on population-based studies about Mexican older people living in Mexico were included. The analysis involved bibliometric indicators regarding productivity, authorship, and impact. The findings show that the volume of scientific output was low, 28 articles, and they were published in Spanish at the beginning of the period; however, during the 2000s decade, scientific production increased considerably, with 138 articles, most of them published in English and in international journals. Epidemiology of aging was the main domain of knowledge (79%) and health services articles were the secondary domain; 96% of studies used quantitative methods. Most of the articles were published in journals with impact factor and in the second and third quartiles, besides the average number of citation was 16.2 and 17 articles were the top-cited publications. The scientific community had 465 authors, but only 54 authors were the ones who guided the main production of this field, among them, 17 prolific authors were notable because of their productivity and participation. This review shows the consolidation of epidemiology of aging as a field of public health in Mexico.
    Keywords:  Aging; Bibliometrics; Mexico; Public Health
  3. Int J Infect Dis. 2020 May 17. pii: S1201-9712(20)30320-9. [Epub ahead of print]
    Li C, Ojeda-Thies C, Renz N, Margaryan D, Perka C, Trampuz A.
      OBJECTIVES: The purpose of the present study was to estimate the trends and state of research of periprosthetic joint infection (PJI).METHODS: Publications on PJI published between 1998 and 2018 were searched from the Web of Science database and analyzed using bibliometrics. The Altmetric score and Research Interest score were combined to provide a weighted count. The scope of the Altmetric score includes >16 weighted composite scores from websites such as Twitter, Facebook and YouTube, whereas the Research Interest score is calculated from information derived from ResearchGate.
    RESULTS: A total of 3245 documents were published. The largest contribution was made by the United States (US), with the most contributive institution the Rothman Institute. The most relative articles were published by the Journal of Arthroplasty, whereas the highest citation frequency journal was Clinical Orthopaedics and Related Research. There was a positive correlation between citation counts and Research Interest scores, while the Altmetric Attention score showed a negative value for highly cited articles.
    CONCLUSIONS: Based on the current trends of globalization, there is a rising trend in publications on PJI, with the largest annual contributions made by the US. The most influential contributors are researchers from the US and Europe. Twitter is used as a platform to communicate knowledge by most PJI researchers. More recent research will focus on the diagnosis and risk factors of PJI.
    Keywords:  arthroplasty; bibliometrics; medical Information sciences; periprosthetic joint infection; publications
    DOI:  https://doi.org/10.1016/j.ijid.2020.05.014
  4. Medicine (Baltimore). 2020 May;99(20): e20114
    Tian L, Zhang Y, Zeng J, Wang L, Gao H, Su Y, Li Y.
      INTRODUCTION: Venous thromboembolism (VTE) in children not only imposes a heavy burden on the medical resources and economy of the society, but also seriously affects the growth and development of children, even threaten children's lives. A large number of publications have been performed in this field in recent years. In this bibliometric analysis, publications on VTE in children were examined and analyzed to explain the present research hotspots.METHODS: Articles related to VTE in children published in the PubMed database from 1988 to June 18, 2019 were selected as the research sample. BICOMB software was used to retrieve the annual publications, journals, journal source countries and the high-frequency major medical subject headings (MeSH) terms on the articles. Then, the co-word matrix was constructed by BICOMB using the selected high-frequency MeSH terms. Next, gCLUTO software was used to analyze the matrix by double clustering and visual analysis in a strategy of hotspot identification. In addition, CiteSpace software was used to perform the knowledge map of co-authors to explore the core authors.
    RESULTS: One thousand seven hundred seventy-nine articles on VTE in children were obtained. Seven hundred ninety academic journals distributed in 58 countries have published articles on VTE in children, and the developed countries and the United States were the major force in the journal source countries. Nowak-Göttl U occupied an important position in this field. We constructed a co-word matrix composing of 37 high-frequency MeSH terms, generated visual matrix and visual hill, and classified the hot-spots into 5 aspects based on 8 categories.
    CONCLUSION: The results show that the research trend of children's VTE has been increasing gradually, and the sound achievement has been obtained in these hotspots in relation to the area of inherited thrombophilia, prevention and control, treatment, diagnosis, prevalence, risk factors, and complication study. However, there is a lack of communication and cooperation in this field, and the gap of national and regional research results is huge. To sum up, this study provides evidence and guidance for researchers, clinicians, and educators.
    DOI:  https://doi.org/10.1097/MD.0000000000020114
  5. Environ Geochem Health. 2020 May 20.
    Olisah C, Adams JB.
      Since the addition of polybrominated diphenyls and organochlorine pesticides (OCPs) to the world banned list, toxic organophosphate contaminants (OPCs) such as organophosphate flame retardants and organophosphate pesticides have been, respectively, used as substitutes. These chemicals are reported to be more toxic than their halogenated counterparts. It is rare to find a study that focuses on visualising the publication trends of these chemical classes. In this study, we employed a bibliometric model to systematically map research activities between 1990 and 2018 using OPC articles retrieved from the WoS and Scopus databases. A total of 1090 articles were retrieved from the hybrid databases with an article/author and author/article ratio of 0.33 and 3.02, respectively. Articles on OPC studies were positively correlated with the number of years (r2 = 0.96; y = 0.23x2 - 3.82x + 27.90) suggesting an increase in the number of articles on this subject in future. The USA ranked first in terms of articles (n = 245) and citations (n = 12,922) followed by China and India (203 and 89 articles, respectively). Articles from China and the USA had strong collaboration with other countries. Research priorities and top author keywords included pesticides (n = 112), organophosphate (n = 83) and acetylcholinesterase (n = 60) and were also well represented in keywords-plus. Developed countries had higher outputs compared to developing countries. It was observed that from our thematic literature classifications, human toxicity, ecotoxicological impacts, and environmental monitoring of OPCs were of greater importance to scholars, thus indicating the direction of future research. Futuristic studies need to foster partnership with policymakers, journalists, consultants, farmers, artisans and community workers on OPC research. This will not only enhance scientific communication and community engagement but will also increase the awareness of these pollutants to the general public.
    Keywords:  Bibliometric analysis; Organophosphate contaminants; Scopus; Web of science
    DOI:  https://doi.org/10.1007/s10653-020-00594-3
  6. Acta Orthop Traumatol Turc. 2020 May 22.
    Demirtaş A, Karadeniz H, Akman YE, Duymuş TM, Çarkcı E, Azboy İ.
      OBJECTIVE: This study aimed to investigate the academic productivity of and the obstacles encountered by orthopedic residents in Turkey.METHODS: Overall, 220 orthopedic specialists who were registered in the Ministry of Health and had started orthopedic residency between 2009 and 2010 were invited to participate in a survey through e-mail. The survey comprised a total of 19 questions to evaluate the academic works conducted and obstacles encountered during residency. Academic work was defined as an article published in the peer-reviewed journals as well as an oral or poster presentation at a national or international congress. Case reports, letters to the editor, and technical notes were excluded.
    RESULTS: Data were obtained from 116 respondents who completed the survey. In peer-reviewed journals in Science Citation Index (SCI) or SCI-Expanded, the mean number of articles published with and without the first name per resident was 0.09 and 0.73, respectively. In peer-reviewed journals other than those in SCI and SCI-Expanded, the mean number of articles published with and without the first name per resident was 0.37 and 1, respectively. The mean number of oral and poster presentations per resident at national and international congresses was 2.63 and 4.67, respectively. No significant difference in the number of academic works was noted between the regions and institutions (p>0.05). A significant positive correlation was observed between the number of associate professors and assistant professors in the clinic and the total number of academic works (article plus presentation) (p<0.01 and p=0.017, respectively). Regarding encouragement and support to academic works, 6.9% of the respondents found the clinic to be excellent, 20.7% good, 24.1% moderate, and 48.3% bad. No significant difference in encouragement and support to academic works was noted among the institutions (p=0.115). The most common obstacle encountered in conducting academic works was long working hours (74.5%).
    CONCLUSION: Regardless of the region and institution, the participation of orthopedic residents in academic works is low in Turkey. Several obstacles were encountered in conducting academic works, with the most common being long working hours.
    LEVEL OF EVIDENCE: Level IV, Diagnostic study.
    DOI:  https://doi.org/10.5152/j.aott.2020.03.243
  7. Plast Reconstr Surg Glob Open. 2020 Apr;8(4): e2712
    Esmaeeli S, Xu TQ, Wiegmann AL, Jaraczewski T, Seu M, Akin J, Dorafshar AH.
      Background: We aimed to longitudinally study the relative research contributions of US and international plastic surgeons by evaluating publications within the premier plastic surgery journal over the last 2 decades. We hypothesized that even with an increased pressure to publish in this journal, the relative research contributions from American plastic surgeons will continue to be the largest overall and in all subspecialties.Methods: Data for the surgical subspecialty, corresponding author's country of origin, and region were extracted from all original articles in 2 randomly selected monthly issues of Plastic & Reconstructive Surgery (PRS) from the last 2 decades to evaluate longitudinal trends. Data were also extracted from all of the original articles published in PRS for the last 3 years to analyze the recent distribution of research output.
    Results: During the last 2 decades, the relative proportion of total original articles written by US authors has increased. They have published proportionally more articles in the Reconstructive and Breast field while publishing relatively less in the hand/peripheral nerve field. From the first decade of analysis, US authors wrote relatively fewer articles in the hand/peripheral nerve field, whereas in the second decade, the US authors wrote relatively fewer articles in the Experimental field. In the last 3 years, US authors published relatively fewer articles in the Experimental and Cosmetic fields.
    Conclusions: Each country's scientific productivity in PRS is related to funding, interest, patients' demand, and healthcare market pressure. In this study, we see that these factors influence trends within research publications over the last 2 decades.
    DOI:  https://doi.org/10.1097/GOX.0000000000002712
  8. Int J Environ Res Public Health. 2020 May 18. pii: E3526. [Epub ahead of print]17(10):
    Jurado de Los Santos P, Moreno-Guerrero AJ, Marín-Marín JA, Soler Costa R.
      The term "equity" (EQUI) is a complex concept to be defined, because it depends on many factors, mainly political ideals. The objective of this research is to determine the evolution and development of the term equity in education by the scientific community. The main objective is to identify the scientific production and performance of the term equity in the field of education. The research method developed is based on bibliometrics, specifically on the technique of scientific mapping, and a process of quantification, analysis, evaluation and estimation of scientific documents was developed. The results indicate there is no established line of research or strong connections between the themes. This shows the existing variety of research on the term equity. Thus, the trend in research on the term equity is focused on the early periods of study on the students' diversity in order to evolve to more concrete and specific aspects of equity, such as gender and race. It is concluded that the theoretical framework of reference shows how equity should be incorporated into the education system under the parameters of equal opportunities, of equality in access to higher education, regardless of gender or socio-cultural background.
    Keywords:  Web of Science; bibliometric analysis; education; equity; scientific mapping; scientific production
    DOI:  https://doi.org/10.3390/ijerph17103526
  9. Mar Drugs. 2020 May 18. pii: E264. [Epub ahead of print]18(5):
    Rumin J, Nicolau E, Junior RGO, Fuentes-Grünewald C, Picot L.
      A bibliographic database of scientific papers published by authors affiliated to research institutions worldwide, especially focused in Europe and in the European Atlantic Area, and containing the keywords "microalga(e)" or "phytoplankton" was built. A corpus of 79,020 publications was obtained and analyzed using the Orbit Intellixir software to characterize the research trends related to microalgae markets, markets opportunities and technologies that could have important impacts on markets evolution. Six major markets opportunities, the production of biofuels, bioplastics, biofertilizers, nutraceuticals, pharmaceuticals and cosmetics, and two fast-evolving technological domains driving markets evolution, microalgae harvesting and extraction technologies and production of genetically modified (GM-)microalgae, were highlighted. We here present an advanced analysis of these research domains to give an updated overview of scientific concepts driving microalgae markets.
    Keywords:  Europe; GMO; bibliometric; biofertilizers; bioplastics; biotechnology; cosmetics; food; market; microalgae; nutraceuticals; pharmaceuticals; research
    DOI:  https://doi.org/10.3390/md18050264
  10. Environ Toxicol Pharmacol. 2020 May 19. pii: S1382-6689(20)30089-2. [Epub ahead of print] 103413
    Andreo-Martínez P, Oliva J, Giménez-Castillo JJ, Motas M, Quesada-Medina J, Cámara MÁ.
      This work aims to provide a comprehensive study of the available research information on pesticide residues in honey through literature analysis. The research advancements within this research field from 1948 to 2019 are addressed using the Web of Science database. The results from the 685 articles analyzed indicate that this research field is in the focus of interest nowadays (Price index: 47.5 %). The yearly production increased steadily from 2001 on, and authors, journals, and institutions followed Lotka's law. On the other hand, Pico, Y (Spain) (2.5 %), Journal of Chromatography A (5.8 %), the USA (15.0 %) and Agricultural Research Service (USA) (4.0 %) were the most productive author, journal, country and institution, respectively. The research hotspots of this field, according to keyword analysis, are related to the chromatographic techniques for the determination of pesticides such as imidacloprid, neonicotinoids, or coumaphos in honey and derivate products such as propolis and wax.
    Keywords:  Bibliometric review; Honey; Honey-bees; Pesticide; Residues
    DOI:  https://doi.org/10.1016/j.etap.2020.103413
  11. Inflamm Bowel Dis. 2020 May 22. pii: izaa091. [Epub ahead of print]
    Barash Y, Klang E, Tau N, Ben-Horin S, Mahajna H, Levartovsky A, Arebi N, Soffer S, Kopylov U.
      BACKGROUND AND AIM: Inflammatory bowel disease (IBD) research is extensive and increasing, with topics varying and shifting foci over time. A comprehensive analysis of the trends in IBD publications may help us grasp knowledge gaps and map future areas of interest. The aim of our study was to create a map of IBD research for the last 25 years using computational text-mining techniques.METHODS: We retrieved all available MEDLINE/PubMed annual datasets between 1992 and 2016. We categorized article characteristics by using word combination and title match techniques. We also assigned country of origin for each article from the first author's affiliation.
    RESULTS: During the study period, 18,653 publications that appeared on PubMed were classified as IBD-related. The annual number of publications increased almost 4-fold (354 to 1361) during the study period. The United States had the highest total number of publications (n = 3179/16,358, 19.4%) and Denmark, Sweden, and Israel had the highest rate of publications per capita. There were 7986 articles successfully assigned with a main subject. Therapeutics, surgical treatment, and endoscopy were the 3 leading topics, with n = 2432/7986 (30%), 1707/7986 (21%), and 981/7986 (12%), respectively. When analyzing trends in topics over time, we found an increase in the proportion of articles on imaging (2.2% in 1992-1996 to 8% in 2012-2016) and a decrease in the proportion of articles on surgical treatment (30% in 1992-1996 to 19% in 2012-2016).
    CONCLUSIONS: There is steady increase in the number of IBD-related publications. Although the United States is a world leader in the number of IBD publications, Denmark, Sweden, and Israel publish the most per population size. Medical therapeutics is the most popular topic, yet there is a steady increase in publications devoted to imaging and monitoring.
    Keywords:  Crohn; PubMed; ulcerative colitis
    DOI:  https://doi.org/10.1093/ibd/izaa091
  12. Simul Healthc. 2020 May 18.
    Lydon S, Madden C, De Bhulbh Á, Maher S, Byrne D, OʼConnor P.
      STATEMENT: Publication in peer-reviewed journals, and serving on editorial boards, is considered an indicator of academic productivity and success, and a means of influencing discourse and practice in a field. This bibliometric review explored gender in authorship, and editorship, across the 3 existing English language, nonspecialty specific healthcare simulation journals. In total, 40.4% of publications had women first authors and 34.4% had women senior authors. There were no differences by journal and no apparent changes over time. Poor participation of women on editorial boards (38.1% of editorial board members were women) was observed. The observed level of representation of women as first and senior authors, and on editorial boards, is comparable with other health sciences domains but nonetheless warrants attention and improvement. Future research examining the profile of those working within simulation or evaluating strategies to improve the participation of women within healthcare simulation research and journals would be of interest.
    DOI:  https://doi.org/10.1097/SIH.0000000000000453
  13. Free Radic Biol Med. 2020 May 18. pii: S0891-5849(20)30616-X. [Epub ahead of print]
    Agarwal A, Baskaran S, Panner Selvam MK, Finelli R, Barbarosie C, Robert KA, Iovine C, Master K, Henkel R.
      Unraveling the role of reactive oxygen species and associated oxidative stress (OS) in male reproduction is one of the key areas of male reproductive research. This article illustrates the scientific landscape of OS in male reproductive research over the past several decades (1941-2018) using a scientometric approach. Scientometric data (articles per year, authors, affiliations, journals, and countries) on OS related to male reproduction were retrieved from the Scopus database and analyzed for each decade. Our analysis revealed an increasing trend in OS-based male reproductive research from 1941 to 2018 with a steep raise in publications and research collaborations starting from the period 1991-2000 (R2 = 0.81). Semen abnormalities and varicocele were the major areas investigated in relation to OS with the highest positive trend in publications from the time interval of 1981-1990 to 2011-2018. Analysis of publications based on OS assessment techniques revealed chemiluminescence (n = 180) and evaluation of antioxidants (n = 300) as the widely used direct and indirect test, respectively. Furthermore, prognostic/diagnostic studies on OS evaluation increased significantly over the time. Our analysis highlights the evolution of OS in male reproductive research and its emergence as an important prognostic and diagnostic tool in the evaluation of male infertility.
    Keywords:  Diagnosis; Male infertility; Oxidative stress; Prognosis; Publications; Scientometric analysis
    DOI:  https://doi.org/10.1016/j.freeradbiomed.2020.05.008
  14. Int J Environ Res Public Health. 2020 May 19. pii: E3540. [Epub ahead of print]17(10):
    Phan HT, Vu GV, Vu GT, Ha GH, Pham HQ, Latkin CA, Tran BX, Ho CSH, Ho RCM.
      Globally, approximately 335 million people are being affected by asthma. Given that asthma is a chronic airway condition that cannot be cured, the disease negatively impacts physical health and results in losses of productivity of people experiencing asthma, leading to decrease in quality of life. This study aims at demonstrating the research trends worldwide and identifying the research gaps in interventions for improving quality of life of patients with asthma. Bibliometric approach and content analysis, which can objectively evaluate the productivity and research landscapes in this field, were utilized. In this study, we systematically quantified the development of research landscapes associated with interventions for improving quality of life of people experiencing asthma. Along with the gradual growth in the number of publications, these research topics have relatively expanded in recent years. While the understanding of the pathophysiology, diagnosis and treatment of asthma has been well-established, recent research has showed high interest in the control and management of asthma. Findings of this study suggest the need for more empirical studies in developing countries and further investigation into the effects of environment factors on asthma outcomes, as well as the economic burden of asthma.
    Keywords:  HRQoL; asthma; content analysis; interventions; quality of life; scientometrics; text mining
    DOI:  https://doi.org/10.3390/ijerph17103540
  15. Proc Natl Acad Sci U S A. 2020 May 19. pii: 201910160. [Epub ahead of print]
    Packalen M, Bhattacharya J.
      The National Institutes of Health (NIH) plays a critical role in funding scientific endeavors in biomedicine. Funding innovative science is an essential element of the NIH's mission, but many have questioned the NIH's ability to fulfill this aim. Based on an analysis of a comprehensive corpus of published biomedical research articles, we measure whether the NIH succeeds in funding work with novel ideas, which we term edge science. We find that edge science is more often NIH funded than less novel science, but with a delay. Papers that build on very recent ideas are NIH funded less often than are papers that build on ideas that have had a chance to mature for at least 7 y. We have three further findings. First, the tendency to fund edge science is mostly limited to basic science. Papers that build on novel clinical ideas are not more often NIH funded than are papers that build on well-established clinical knowledge. Second, novel papers tend to be NIH funded more often because there are more NIH-funded papers in innovative areas of investigation, rather than because the NIH funds innovative papers within research areas. Third, the NIH's tendency to have funded papers that build on the most recent advances has declined over time. In this regard, NIH funding has become more conservative despite initiatives to increase funding for innovative projects. Given our focus on published papers, the results reflect both the funding preferences of the NIH and the composition of the applications it receives.
    Keywords:  biomedicine; funding; ideas; novelty; science
    DOI:  https://doi.org/10.1073/pnas.1910160117
  16. Nature. 2020 May 20.
    Viglione G.
      
    Keywords:  Publishing; Research management
    DOI:  https://doi.org/10.1038/d41586-020-01294-9
  17. Clin Chem. 2020 May 20. pii: hvaa093. [Epub ahead of print]
    McGrath TA, Bowdridge JC, Prager R, Frank RA, Treanor L, Dehmoobad Sharifabadi A, Salameh JP, Leeflang M, Korevaar DA, Bossuyt PM, McInnes MDF.
      BACKGROUND: To compare the frequency of "spin" in systematic reviews of diagnostic accuracy studies in high-impact journals with the frequency a previously assessed series of reviews.METHODS: Medline was searched from January 2010 to January 2019. Systematic reviews of diagnostic accuracy studies were included if they reported a meta-analysis and were published in a journal with an impact factor >5. Two investigators independently scored each included systematic review for positivity of conclusions and for actual and potential overinterpretation practices.
    RESULTS: Of 137 included systematic reviews, actual overinterpretation was present in ≥1 form in the abstract in 63 (46%) and in the full-text report in 52 (38%); 108 (79%) contained a form of potential overinterpretation. Compared with the previously assessed series (reviews published 2015-2016), reviews in this series were less likely to contain ≥1 form of actual overinterpretation in the abstract and full-text report or ≥1 form of potential overinterpretation (P < 0.001 for all comparisons). The significance of these comparisons did not persist for actual overinterpretation in sensitivity analysis in which Cochrane systematic reviews were removed. Reviews published in the Cochrane Database of Systematic Reviews were less likely to contain actual overinterpretation in the abstract or the full-text report than reviews in other high-impact journals (P < 0.001 for both comparisons).
    CONCLUSIONS: Reviews of diagnostic accuracy studies in high-impact journals are less likely to contain overinterpretation or spin. This difference is largely due to the reviews published in the Cochrane Database of Systematic Reviews, which contain spin less often than reviews published in other high-impact journals.
    DOI:  https://doi.org/10.1093/clinchem/hvaa093
  18. Antioxidants (Basel). 2020 May 18. pii: E439. [Epub ahead of print]9(5):
    McElroy T, Allen AR.
      Oxidative stress is considered one of the possible mechanisms behind chemobrain or the cognitive dysfunction persistent after chemotherapy treatment. Breast cancer patients have reported chemobrain symptoms since the 1990s. In this present bibliometric review, we employed the VOSviewer tool to describe the existing landscape on literature concerning oxidative stress, breast cancer chemotherapies, and chemobrain. As of 2019, 8799 papers were listed in the Web of Science database, with more than 900 papers published each year. As expected, terms relating to oxidative stress, mitochondria, breast cancer, and antioxidants have occurred very often in the literature throughout the years. In recent years, there has been an increase in the occurrence of terms related to nanomedicine. Only within the last decade do the keywords 'brain', 'blood-brain barrier', and 'central nervous system' appear, reflecting an increased interest in chemobrain. China has become the most prolific producer of oxidative stress and chemotherapy related papers in the last decade followed by the USA and India. In conclusion, the subject of oxidative stress as a mechanism behind chemotherapies' toxicities is an active area of research.
    Keywords:  antioxidants; chemobrain; chemotherapy; cognitive dysfunction; oxidative stress
    DOI:  https://doi.org/10.3390/antiox9050439
  19. BMC Med Res Methodol. 2020 May 18. 20(1): 121
    Marušić MF, Fidahić M, Cepeha CM, Farcaș LG, Tseke A, Puljak L.
      BACKGROUND: A crucial element in the systematic review (SR) methodology is the appraisal of included primary studies, using tools for assessment of methodological quality or risk of bias (RoB). SR authors can conduct sensitivity analyses to explore whether their results are sensitive to exclusion of low quality studies or a high RoB. However, it is unknown which tools do SR authors use for assessing quality/RoB, and how they set threshold for quality/RoB in sensitivity analyses. The aim of this study was to assess quality/RoB assessment tools, the types of sensitivity analyses and quality/RoB thresholds for sensitivity analyses used within SRs published in high-impact pain/anesthesiology journals.METHODS: This was a methodological study. We analyzed SRs published from January 2005 to June 2018 in the 25% highest-ranking journals within the Journal Citation Reports (JCR) "Anesthesiology" category. We retrieved the SRs from PubMed. Two authors independently screened records, full texts, and extracted data on quality/RoB tools and sensitivity analyses. We extracted data about quality/RoB tools, types of sensitivity analyses and the thresholds for quality/RoB used in them.
    RESULTS: Out of 678 analyzed SRs, 513 (76%) reported the use of quality/RoB assessments. The most commonly reported tools for assessing quality/RoB in the studies were the Cochrane tool for risk of bias assessment (N = 251; 37%) and Jadad scale (N = 99; 15%). Meta-analysis was conducted in 451 (66%) of SRs and sensitivity analysis in 219/451 (49%). Most commonly, sensitivity analysis was conducted to explore the influence of study quality/RoB (90/219; 41%) on the results. Quality/RoB thresholds used for sensitivity analysis for those studies were clearly reported in 47 (52%) articles that used them. The quality/RoB thresholds used for sensitivity analyses were highly heterogeneous and inconsistent, even when the same tool was used.
    CONCLUSIONS: A quarter of SRs reported using quality/RoB assessments, and some of them cited tools that are not meant for assessing quality/RoB. Authors who use quality/RoB to explore the robustness of their results in meta-analyses use highly heterogeneous quality/RoB thresholds in sensitivity analyses. Better methodological consistency for quality/RoB sensitivity analyses is needed.
    Keywords:  Bias; Quality assessment; Sensitivity analysis; Systematic review
    DOI:  https://doi.org/10.1186/s12874-020-00966-4
  20. Scientometrics. 2020 ;123(2): 707-733
    González-Alcaide G, Pinargote H, Ramos JM.
      In co-authorship networks, some nodes play the key role of cut-point, facilitating the integration of other authors and favoring connectivity among different research communities. The present study uses bibliometric and network embeddedness indicators to analyze the scientific activity on ventilator-associated pneumonia and the roles of 17 research communities and 30 cut-points therein. In addition to fostering network connectivity and cohesion, cut-points are characterized by other differential features compared to other authors, including a much higher level of productivity and greater participation in leadership positions, higher betweenness values, lower clustering coefficients and higher levels of constraint. The cut-points identified have different characteristics in terms of the connectivity they facilitate between research communities: some cut-points have established weak intercommunity ties in the form of bridges with a single author from a different community; in other cases, they serve as gatekeepers due to their connection with different authors of a community that they link with their own; cut-points may also act as structural folds, that is, actors with an overlapping role between two cohesive communities. The cut-points present very diverse connectivity degrees, with some cut-points whose elimination would provoke severe network fragmentation and others who are responsible for linking far fewer external authors to their network. The cut-points that present both the main mechanisms for obtaining social capital-that is, filling structural holes and participating in cohesive network structures-can be considered key actors/players because their participation is crucial for ensuring both integration into the main research focus of some communities with high research performance and the overall cohesion of a co-authorship network.
    Keywords:  Bridges; Brokers; Connectivity roles; Gatekeepers; Pneumonia; Research performance
    DOI:  https://doi.org/10.1007/s11192-020-03404-w