Bibliometric and visual analysis of cardiovascular diseases and COVID-19 research

Research on therapeutic clinical trials including immunotherapy in triple-negative breast cancer: a bibliometric analysis

Background

Breast cancer, particularly triple-negative (TNBC), is a leading malignancy with aggressive traits and high metastasis rates. Clinical trial is an important tool for optimizing therapeutic strategies in the evaluation of the safety and efficacy for TNBC. Our bibliometric study of TNBC clinical trials aims to assess therapeutic strategies, identify trends, and explore advancements in treatment. We focus on mapping knowledge development, including key research entities and topics, and analyzing research trends and emerging methods. This analysis intends to inform future research, especially in personalized and precision medicine for TNBC.

Methods

We selected publications on clinical trials for the treatment of TNBC from 1997 to 2024 in the Web of Science Core Collection (WoSCC). After an initial screening, we downloaded key data including titles, publication years, authors, countries, institutional affiliations, journals, keywords, and abstracts, and saved them in BibTex format. We then conducted a bibliometric analysis using Bibliometrix in R and VOSviewer to illustrate the prospects, highlights, and trends of TNBC treatment options. Furthermore, to emphasize the hot topics in TNBC treatment strategies, we performed a bibliometric analysis of immunotherapy using the same approach.

Results

1907 publications were included, most of which were from China, Italy, and the United States. The number of annual publications has increased dramatically since 2010. The focus of TNBC clinical trial research has shifted from understanding the biology, such as breast cancer subtyping and genotyping, to novel therapeutic approaches. The major advancement in clinical trials is the switch from late-stage palliative treatment to early preoperative neoadjuvant therapy, as more TNBC cases are discovered at an early stage. Immunotherapy is also highlighted with additional alternatives for advanced or metastasized TNBC, such as targeted inhibitors with unusual mutation rates and antibody drug conjugates (ADC).

Conclusions

This investigation made it apparent how immunotherapy has recently made major advancements in TNBC treatment plans and how ADCs, or targeted therapies, are currently popular for TNBC. By identifying significant papers, comprehending trending topics, and collaborating across multiple disciplines, this study may accelerate research on TNBC therapy options.

A bibliometric analysis of myocardial bridge combined with myocardial infarction

BACKGROUND

The aim of this study is to analyze the process and frontiers of research in myocardial bridges (MB) to identify future research directions in the last 3 decades.

METHODS

Relevant literature on MB combined with myocardial infarction (MI) was searched from 1991 to 2023 in the Web of Science database, and was analyzed by bibliometric analysis using VOSviewer, CiteSpace, and the R package "bibliometrix."

RESULTS

A total of 1233 English articles were included in this study. The number of published articles showed an increasing trend yearly. From 2017 to 2022, the annual publication volume rose rapidly, and in 2021 the publication volume even reached 95 articles, which was the highest in all years. These publications were from 68 countries and 1854 institutions, with the leading country being the U.S. and the leading institution being Columbia University. Myoho Clinical International has a close collaborative relationship with Columbia University, while in recent years, the Harvard Medical School has explored the study of MB combined with MI. Annals of Thoracic Surgery was the journal with the highest number of publications, and Takayama Hiroo and Naka Yoshifumi were the authors with the highest number of publications. The most common keywords were MI, cardiogenic shock, and MB.

CONCLUSIONS

Our findings can help researchers explore the current status of MB combined with MI research and choose new survey routes for upcoming studies. Prevalence and prognosis, mechanism of MB combined with MI and molecular mechanism may become the focus of future research. In addition, more research and cooperation are needed worldwide.

A bibliometric analysis of the knowledge related to mental health during and post COVID-19 pandemic

Objective

COVID-19 led to a horrific global pandemic, with strict lockdowns and prolonged indoor stays increasing the risk of mental health problems, affecting people of different ages, genders, regions, and types of work to varying degrees. This study provides a bibliometric summary of the knowledge map related to mental health during and post COVID-19 pandemic.

Methods

Publications related to mental health during and post COVID-19 pandemic were searched in the Web of Science Core Collection (WoSCC) database through March 19, 2024. After screening the search results, the literature included in the final was first quantitatively analyzed using GraphPad Prism software and then visualized using VOSviewer, CiteSpace, and R (the bibliometrix package).

Results

The 7,047 publications from 110 countries were included, with the highest number of publications from China and the United States, and the number of publications related to mental health during and post the COVID-19 pandemic increased annually until 2023, after which it began to decline. The major institutions were University of Toronto, University of London, Harvard University, King's College London, University College London, University of California System, University of Melbourne, Institut National De La Sante Et De La Recherche Medicale (Inserm), Mcgill University, and University of Ottawa; Frontiers in Psychiatry had the highest number of publications, and the Journal of Affective Disorders had the highest number of co-citations; 36,486 authors included, with Xiang, Yu-Tao, Cheung, Teris, Chung, Seockhoon published the most papers, and World Health Organization, Kroenke K, and Wang CY were the most co-cited; epidemiologically relevant studies on mental health related to COVID-19, and the importance of mental health during normalized epidemic prevention and control are the main directions of this research area, especially focusing on children's mental health; "pandemic," "sars-cov-2," "epidemic," "depression," "coronavirus anxiety," "anxiety," "longitudinal," "child," "coronavirus anxiety," "longitudinal," "child," and "coronavirus" are the top keywords in recent years.

Conclusion

This comprehensive bibliometric study summarizes research trends and advances in mental health during and after the COVID-19 Pandemic. It serves as a reference for mental health research scholars during and after the COVID-19 pandemic, clarifying recent research preoccupations and topical directions.

Saliva-based detection of SARS-CoV-2: a bibliometric analysis of global research

Saliva has emerged as a promising noninvasive biofluid for the diagnosis of oral and systemic diseases, including viral infections. During the coronavirus disease 2019 (COVID-19) pandemic, a growing number of studies focused on saliva-based detection of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Taking advantage of the WoS core collection (WoSCC) and CiteSpace, we retrieved 1021 articles related to saliva-based detection of SARS-CoV-2 and conducted a comprehensive bibliometric analysis. We analyzed countries, institutions, authors, cited authors, and cited journals to summarize their contribution and influence and analyzed keywords to explore research hotspots and trends. From 2020 to 2021, research focused on viral transmission via saliva and verification of saliva as a reliable specimen, whereas from 2021 to the present, the focus of research has switched to saliva-based biosensors for SARS-CoV-2 detection. By far, saliva has been verified as a reliable specimen for SARS-CoV-2 detection, although a standardized procedure for saliva sampling and processing is needed. Studies on saliva-based detection of SARS-CoV-2 will promote the development of saliva-based diagnostics and biosensors for viral detection. Collectively, our findings could provide valuable information to help scientists perceive the basic knowledge landscapes on saliva-based detection of SARS-CoV-2, the past and current research hotspots, and future opportunities.

Bibliometric analysis of research trends and active research areas in chimeric antigen receptor T cell therapy for hematologic malignancies

BACKGROUND

In the past decade, chimeric antigen receptor (CAR) T-cells have successfully treated cancers, especially hematologic malignancies. Although many articles have been published on CAR T-cell therapy for hematologic malignancies, bibliometric analysis remains unexplored.

AIM

This study aimed to investigate and analyze existing trends and active research areas on CAR T-cell therapy for hematologic malignancies, providing novel perspectives for clinical decision-making and scientific research.

METHOD

From 2000 to 2023, the Web of Science Core Collection was searched for articles published on CAR T-cells for the treatment of hematologic malignancies. Comprehensive visual analyses of annual publication, country, institutions, authors, co-cited references, and keywords were performed using CiteSpace software and VOSviewer.

RESULTS

A total of 2,451 articles on CAR T-cells were published to treat hematologic malignancies from 01 January 2000 to 31 August 2023. The United States, China, and Germany were the top three nations in publications. In the keyword analysis, "immunotherapy" and "chimeric antigen receptor" were used most frequently. Moreover, the yellow node, which included terms such as "chimeric antigen receptor T cells," "efficacy," "CAR T-cell therapy," "toxicity," "CAR-NK," and "tumor microenvironment" were most active research areas.

CONCLUSION

This study provided a comprehensive analysis of publications on CAR T-cell therapy for hematologic malignancies from 2000 to 2023. The findings provide current trends and potential hotspots in CAR T-cell therapy for hematologic malignancies and contribute valuable direction for future studies in this field.

Evolutionary trend analysis and knowledge structure mapping of endothelial dysfunction in sepsis: a bibliometrics study

BACKGROUND

A pathophysiological feature of septic organ failure is endothelial dysfunction in sepsis (EDS). The physiological and pathological mechanism of sepsis is considered to be vascular leakage caused by endothelial dysfunction. These pathological changes lead to systemic organ injury. However, an analysis using bibliometric methods has not yet been conducted in the field of EDS. This study was conducted to provide an overview of knowledge structure and research trends in the field of EDS.

METHODS

Based on previous research, a literature search was performed in the Web of Science Core Collection (WoSCC) for publications associated with EDS published between the year 2003 and 2023. Various types of data from the publications, such as citation frequency, authorship, keywords and highly cited articles, were extracted. The "Create Citation Report" feature in the WoSCC was employed to calculate the Hirsch index (h-index) and average citations per item (ACI) of authors, institutions, and countries. To conduct bibliometric and visualization analyses, three bibliometric tools were used, including R-bibliometrix, CiteSpace (co-citation analysis of references), and VOSviewer (co-authorship analysis of institutions, co-authorship analysis of authors, co-occurrence analysis of keywords).

RESULTS

After excluding invalid records, the study finaly included 4,536 publications with 135,386 citations. Most of these publications originated in the USA, China, Germany, Canada, and Japan. Harvard University emerged as the most prolific institution, while professor Jong-Sup Bae and his research team at Kyungpook National University emerged as authors with the greatest influence. The "protein C", "tissue factor", "thrombin", "glycocalyx", "acute kidney injury", "syndecan-1" and "biomarker" were identified as prominent areas of research. Future research may focus on molecular mechanisms (such as as vascular endothelial [VE]-cadherin regulation) and therapeutic interventions to enhance endothelial repair and function.

CONCLUSION

Our findings show a growing interest in EDS research. Key areas for future research include signaling pathways, molecular mechanisms, endothelial repair, and interactions between endothelial cells and other cell types in sepsis.

COVID-19 and chronic kidney disease: a bibliometric analysis

Background

The COVID-19 pandemic has caused over 656 million confirmed cases and over 6.6 million deaths worldwide. Chronic kidney disease (CKD) is considered a high-risk factor for COVID-19; therefore, considerable research has been conducted in this field. Therefore, this study aims to conduct a bibliometric analysis of publications related to COVID-19 and CKD.

Methods

Publications were retrieved from the Web of Science Core Collection database on 16 January 2023 and screened based on inclusion criteria. Then the authors used Microsoft Excel and CiteSpace to analyze the included publications from the following seven aspects: countries/regions, institutions, journals, authors, cited references, and keywords.

Results

In total, 622 publications were included in the study. The USA has the most publications in this field, followed by China. The Icahn School of Medicine at Mount Sinai and Harvard Medical School had the highest number of publications in the field. Journal of Clinical Medicine had the largest number of publications, and Lancet was the most cited journal. Alberto Ortiz was the author with the largest number of publications, but there were no influential authors in this field. The highly cited references are mainly clinical studies on COVID-19. Research hotspots in this field include end-stage recent disease, cardiovascular disease, kidney metastasis, diabetes Mellitus, acute kidney injury, meta-analysis, and consistent plasma.

Conclusions

The USA, China, and some European countries and their institutions are major contributors to these publications. End-stage renal disease, acute kidney injury, kidney transplantation and convalescent plasma are current hot topics in the field.

Intraocular lens power calculation formulas: a scientometric analysis

Background

The most accurate method of intraocular lens (IOL) power calculation in cataract surgery has not been determined, and further studies are needed to reach a consensus. The aim of this study was to assess publications related to IOL power calculation formulas, mapping their yearly trends, most productive authors, top publishing countries and institutions, and areas of specialization for IOL power formulas.

Methods

We conducted a comprehensive analysis of research articles published on the topic of IOL power calculation formulas. Using PubMed, we employed appropriate search terms and filtered the results for the period of January 1, 1946, to June 28, 2023. Data were analyzed using CiteSpace, VOSviewer, and Microsoft Excel programs. The visual representations of the collected data through the use of figures was provided to demonstrate the aspects of IOL power calculation research.

Results

We retrieved 5475 documents in the initial search. Analysis of these documents revealed an increase in the number of publications, from one publication in 1946 to 201 publications in 2023. The top three countries contributing to these publications were the United States, China, and Japan, collectively accounting for over 27% of the total articles. However, the two institutions with the highest contributions were located in the United Kingdom and Hungary, neither of which was among the top 10 countries in overall contributions. Overall 15 326 authors contributed to publications pertaining to IOL power calculation formulas. Among these authors, the most prolific contributors included Achim Langenbucher from Saarland University (Germany), Giacomo Savini from G.B. Bietti Foundation I.R.C.C.S. (Italy), and Kenneth J Hoffer from the University of California (United States). Saarland University emerged as the most productive institution, contributing equally to two distinct departments: the Dr. Rolf M. Schwiete Center for Limbal Stem Cell Research and Congenital Aniridia, as well as the Department of Experimental Ophthalmology. The School of Physical Science at the Open University in the United Kingdom engaged in partnership with various institutions including Eye & Laser Clinic Castrop Rauxel in Germany and Johannes Kepler University Linz in Austria. Among the top 10 keywords found in the publications were "cataract", "cataract surgery", and "intraocular lens".

Conclusions

This study represents the first scientometric analysis of publications related to IOL power calculation formulas. The study offers valuable insights into the geographic distribution, contributing authors, and emphasis of research on the IOL power calculation formulas. Further cooperation is essential to pinpoint the most suitable formula and to address gaps in our current understanding.

Global research trends and prospects related to tumor microenvironment within Triple Negative Breast Cancer: a bibliometric analysis

Background and aims

The tumor microenvironment (TME) has pivotal parts within multiple tumor models of onset/progression, such as triple-negative breast cancer (TNBC). This bibliometric analysis was developed to explore trends and research niches revolving around TME in TNBC.

Methods

Web of Science Core Collection was queried for identifying studies linked with TME in TNBC, after which the VOSviewer, CiteSpace, and R software programs were used to conduct bibliometric analyses and to generate corresponding visualizations.

Results

In total, this study included 1,604 studies published from 2005-2023. The USA and China exhibited the highest numbers of citations, and the research institutions with the greatest output in this field included Harvard University, the University of Texas System, and Fudan University. Ying Wang from Sun Yat-Sen University was the most published and most cited author in this space. The highest number of articles were published in Cancer, while the greatest co-citation number was evident in Breast Cancer Research. Important keywords related to this research topic included metastasis, tumor-infiltrating lymphocytes, immunotherapy, chemotherapy, and nanoparticles. In particular, pembrolizumab, immunotherapy, nanoparticles, combination treatment, and biomarkers were topics of marked interest in recent reports.

Conclusion

The TME in TNBC is an area of rapidly growing and evolving research interest, with extensive global collaboration helping to drive this field forward. Antitumor therapies targeting the TME in TNBC patients represent an emerging topic of future research, providing opportunities for translational findings. The results of this analysis may provide additional guidance for work focused on the TME in TNBC.

A Scientometric Evaluation of COVID-19 and Male Reproductive Research

The COVID-19 pandemic due to the SARS-CoV-2 coronavirus showed acute and prolonged effects on human health. In addition, over the past four years, there has been a tremendous surge in COVID-19-related scientific publications, as shown by bibliometric and scientometric studies. However, such analysis of the scientific literature is lacking in the area of male reproduction. The current scientometric study analyzes publication characteristics of articles related to male reproduction and COVID-19 infection. We used the Scopus database to analyze scientometric data (the number of publications, journals, countries, type of documents, and subject area) related to COVID-19 and male reproductive research. Our literature search identified 345 articles related to COVID-19 and male reproductive research. Most of the articles were published in the USA (n = 72), Italy (n = 55), and China (n = 51). Such research was mainly focused around medicine (57.1%), followed by biochemistry, genetics, and molecular biology (25.7%). Also, in the area of male reproduction, only 37.1% (n = 128) of the articles contributed towards original research, whereas 52.8% (n = 182) were review articles and editorials focusing more on sexual dysfunction than infertility. Such a small number of studies published on COVID-19-related effects on male reproduction warrants a significant increase in research, which is required to decipher the mechanism(s) underlying SARS-CoV-2 infection-associated impairment of male reproductive function.

Research landscape on COVID-19 and liver dysfunction: A bibliometric analysis

BACKGROUND

The global spread of severe acute respiratory syndrome coronavirus 2, responsible for coronavirus disease 2019 (COVID-19), poses a significant risk to public health. Beyond the respiratory issues initially associated with the condition, severe cases of COVID-19 can also lead to complications in other organs, including the liver. Patients with severe COVID-19 may exhibit various clinical signs of liver dysfunction, ranging from minor elevations in liver enzymes without symptoms to more serious cases of impaired liver function. Liver damage is more commonly observed in patients with severe or critical forms of the disease.

AIM

To present the research landscape on COVID-19 and liver dysfunction while also offering valuable insights into the prominent areas of interest within this particular domain.

METHODS

On 18 February 2023, Scopus was utilised to conduct a comprehensive exploration of the relationship between COVID-19 and the liver dysfunction. The investigation encompassed the period from 1 January 2020 to 31 December 2022. Primary sources were meticulously examined and organised in a Microsoft Excel 2013 spreadsheet, categorised by journal, institution, funding agency, country and citation type. VOSviewer version 1.6.18 was employed to explore the prominent topics and knowledge network related to the subject.

RESULTS

There were 2336 publications on COVID-19 and liver dysfunction analysed in this study, of which 558 were published in 2020, 891 in 2021 and 887 in 2022. Researchers from 111 different countries participated in the retrieved documents. The United States contributed the most studies, with 497 documents, representing 21.28% of the total, followed by China with 393 documents (16.82%) and Italy with 255 documents (10.92%). In the context of research related to COVID-19 and the liver, co-occurrence analysis identified three distinct clusters of topics: (1) 'COVID-19 vaccines in liver transplant recipients'; (2) 'liver function tests as a predictor of the severity and clinical outcomes in hospitalised patients'; and (3) 'care of patients with liver disease during the COVID-19 pandemic'.

CONCLUSION

This bibliometric study provides a comprehensive overview of liver-related publications in COVID-19 research over the past 3 years. This study highlights the significant contributions of high-income nations, particularly the United States, China, and Italy, to the production of liver-related scholarly literature in this field. Most of the articles focused on liver dysfunction in patients with COVID-19 and the implications of the virus for gastroenterologists and hepatologists.

A Forty-Year Analysis of the Literature on Babesia Infection (1982-2022): A Systematic Bibliometric Approach

Babesia infection is a tick-borne protozoan disease associated with significant veterinary, economic, and medical importance. This infection affects many hosts, ranging from wild to domestic animals and including man. All vertebrates serve as potential carriers due to the huge diversity of the species. Babesiosis has been associated with severe economic loss in livestock production, especially in cattle farming, and is also a major public health concern in man, which could be fatal. The infection is usually opportunistic, ranging from asymptomatic to symptomatic, usually in immunocompromised subjects or under conditions of stressful management. This study was designed to uncover trends in relation to publication growth and further explore research output regarding babesiosis from data indexed in the WoS. The WoS is the only platform used to map publications on Babesia infection. The search term "babesiosis" or "Babesia infection" was used to extract articles published across the study period from 1982 to 2022. The inclusion criteria were restricted to only articles for the analysis. The results from the search query showed that a total of 3763 articles were published during the study period with an average of 91.70 ± 43.87 articles annually and an average total citation (n = 1874.8). An annual growth rate of 2.5% was recorded during the study period. The year 2021 had the highest number of published articles (n = 193, 5.1%) and citations (n = 7039). The analysis of the most relevant keywords and titles showed that infection (n = 606, 16.1%), babesiosis (n = 444, 11.7%), and Babesia (n = 1302, 16%) were the most relevant keyword plus (ID), author keyword (DE), and title, respectively. The common conceptual framework analysis through K-means clustering showed two clusters comprising 4 and 41 elements, respectively. The United States of America is the top-performing country in terms of article production (n = 707, 20.8%) and the leading funder for babesiosis research, with two of its agencies ranked at the top. These are the Department of Health and Human Services (n = 254, 6.7%) and the National Institute of Health (n= 238,6.3%). Igarashi I. is the top-performing author (n = 231, 6.1%), while Veterinary Parasitology is ranked the top journal (n = 393, 10.4%) in terms of babesiosis publications. Overall, an increase in publications was observed in the study period, with significant output from developed nations.

How has the field of metastatic breast cancer in bones evolved over the past 22 years?

Background

Although knowledge on metastatic breast cancer in bones (MBCB) has increased rapidly over the past 22 years, a comprehensive and objective bibliometric analysis is still lacking.

Materials and methods

We used R, VOSviewer, and Citespace software to conduct a bibliometric analysis of 5,497 papers on MBCB from the Web of Science Core Collection (WOSCC) using author, institution, country/region, citation, and keyword indicators.

Results

A general strong sense of scholarly collaboration was noted in the MBCB field at the author, research institution, and country/region levels. We discovered some outstanding authors and highly productive institutions, but with less collaboration with other academic groups. Unbalanced and uncoordinated developments were observed among countries/regions in the field of MBCB research. We also found that by using various indicators and applying different analysis methods to them, we were able to broadly identify primary clinical practices, relevant clinical experiments, and directions for bioinformatics regarding MBCB, changes over the past 22 years, and current challenges in the field. The development of knowledge on MBCB is progressing greatly; however, MBCB is still incurable.

Conclusion

This study is the first to use bibliometrics to provide an overall analysis of the scientific output of MBCB studies. Palliative therapies for MBCB are mostly in a mature state. However, research on the molecular mechanisms and immune response to tumors related to the development of treatments to cure MBCB remains relatively immature. Therefore, further research should be undertaken in this area.

Role of Angiotensin II in Cardiovascular Diseases: Introducing Bisartans as a Novel Therapy for Coronavirus 2019

Cardiovascular diseases (CVDs) are the main contributors to global morbidity and mortality. Major pathogenic phenotypes of CVDs include the development of endothelial dysfunction, oxidative stress, and hyper-inflammatory responses. These phenotypes have been found to overlap with the pathophysiological complications of coronavirus disease 2019 (COVID-19). CVDs have been identified as major risk factors for severe and fatal COVID-19 states. The renin-angiotensin system (RAS) is an important regulatory system in cardiovascular homeostasis. However, its dysregulation is observed in CVDs, where upregulation of angiotensin type 1 receptor (AT1R) signaling via angiotensin II (AngII) leads to the AngII-dependent pathogenic development of CVDs. Additionally, the interaction between the spike protein of severe acute respiratory syndrome coronavirus 2 with angiotensin-converting enzyme 2 leads to the downregulation of the latter, resulting in the dysregulation of the RAS. This dysregulation favors AngII/AT1R toxic signaling pathways, providing a mechanical link between cardiovascular pathology and COVID-19. Therefore, inhibiting AngII/AT1R signaling through angiotensin receptor blockers (ARBs) has been indicated as a promising therapeutic approach to the treatment of COVID-19. Herein, we review the role of AngII in CVDs and its upregulation in COVID-19. We also provide a future direction for the potential implication of a novel class of ARBs called bisartans, which are speculated to contain multifunctional targeting towards COVID-19.

Bibliometric analysis of medical and health research collaboration between China and ASEAN countries

Objective

To reveal the characteristics, development trend and potential opportunities of China-ASEAN collaboration in the medical and health field based on bibliometrics.

Methods

Scopus and International Center for the Study of Research Lab (ICSR Lab) was used to analyze the scale, collaboration network and distribution, impact of cooperative papers, collaboration dominance and evolution of the literature on China-ASEAN medical and health collaboration in the Scopus database from 1992 to 2022.

Results

From 1992 to 2022, 19,764 articles on medical and health collaboration between China and ASEAN were filtered for analysis. The number of China-ASEAN collaborations has shown a clear upward trend over the years, indicating a gradually closer and improved collaboration relationship overall. The institutional collaboration network between China and ASEAN countries was obviously clustered, and the network connectivity was limited. The substantial differences between the median and mean values of citation impact of China-ASEAN medical and health research collaboration reflected that the collaboration was 'less' but 'better'. The dominance share of collaboration between China and the main ASEAN countries was fluctuating upward and has become more and more stable after 2004. Most of the China-ASEAN collaboration focused on their own characteristic research topics. In recent years, collaboration in infectious diseases and public health had expanded significantly, while other research topics had maintained in a complementary development trend.

Conclusion

Collaboration between China and ASEAN in the medical and health field has exhibited a progressively closer relationship, and the trend of complementary research has remained stable. However, there are still areas of concern, including the limited scale of collaboration, narrow scope of participation and weak dominance.