A bibliometric analysis of global research on vitamin D and reproductive health between 2012 and 2021: Learning from the past, planning for the future

Global trends in poliomyelitis research over the past 20 years: A bibliometric analysis

Poliomyelitis is an acute infectious disease caused by poliovirus. This bibliometric analysis aims to examine the status of poliomyelitis research in the past 20 years. Information regarding polio research was obtained from the Web of Science Core Collection database. CiteSpace, VOSviewer, and Excel were used to perform visual and bibliometric analysis with respect to countries/regions, institutions, authors, journals and keywords. A total of 5,335 publications on poliomyelitis were published from 2002 to 2021. The USA was the county with the majority of publications. Additionally, the most productive institution was the Centers for Disease Control and Prevention. Sutter, RW produced the most papers and had the most co-citations. Vaccine was the journal with the most polio-related publications and citations. The most common keywords were mainly about polio immunology research ("polio," "immunization," "children," "eradication" and "vaccine"). Our study is helpful for identifying research hotspots and providing direction for future research on poliomyelitis.

Global trends and current status in pheochromocytoma: a bibliometric analysis of publications in the last 20 years

Objective

Pheochromocytoma is a rare catecholamine-producing neuroendocrine tumour originating from the chromaffin cells of the adrenal medulla or extra-adrenal paraganglia. However, there are few bibliometric studies on Pheochromocytoma. Therefore, this study was employed to summarize the global trends and current status in pheochromocytoma by bibliometric analysis.

Materials and methods

The Web of Science (WOS) core collection database was searched for publications relating to pheochromocytoma from 2001 to 2021. Bibliometric analysis was used to examine the data, and Microsoft Excel was utilized to create bar graphs. In addition, VOSviewer was used to carry out co-authorship analysis, co-citation analysis and co-occurrence analysis. CiteSpace was used to analyze the keywords citation bursts.

Results

A total of 8,653 publications published in 1,806 journals by 38,590 authors in 6,117 organizations from 100 countries/regions were included in our study. Among them, USA was the leading countries in terms of total publications and sum of time cited, whereas Eunice Kennedy Shriver Natl Inst Child Hlth & Hum was the leading institutions. The main publications for pheochromocytoma-related articles were Journal of clinical endocrinology &metabolism. Pacak karel and Eisenhofer Graeme were the main contributing authors. The studies on pheochromocytoma could be grouped into five clusters: Treatment, Mechanism, Etiology, Radiology and Hormones study. Moreover, the radiology study, etiology study and some specific keywords such germlines mutation, mesenchymal stem-cells, autophagy, neuroinflammation, neurotoxicity, and hemodynamic instability, may become the hot spots of future.

Conclusion

Although the number of articles on pheochromocytoma has fluctuated slightly over the past 20 years, there has been an overall upward trend. In general, precision medicine research on pheochromocytoma, especially metastatic pheochromocytoma, in terms of diagnosis, treatment, and etiology will be a hot research topic in the future. This study helps to understand the research perspectives, hot spots and trends of pheochromocytoma and provide new insight and a basis for future pheochromocytoma research quickly.

Interaction of air pollution and meteorological factors on IVF outcomes: A multicenter study in China

BACKGROUND

Previous studies revealed associations between air-pollutant exposure and in vitro fertilization (IVF) outcomes. However, modification effects of air pollution on IVF outcomes by meteorological conditions remain elusive.

METHODS

This multicenter retrospective cohort study included 15,217 women from five northern Chinese cities during 2015-2020. Daily average concentrations of air pollutants (PM_2.5, PM₁₀, O₃, NO₂, SO₂, and CO) and meteorological factors (temperature, relative humidity, wind speed, and sunshine duration) during different exposure windows were calculated as individual approximate exposure. Generalized estimating equations models and stratified analyses were conducted to assess the associations of air pollution and meteorological conditions with IVF outcomes and estimate potential interactions.

RESULTS

Positive associations of wind speed and sunshine duration with pregnancy outcomes were detected. In addition, we observed that embryo transfer in spring and summer had a higher likelihood to achieve a live birth compared with winter. Exposure to PM_2.5, SO₂, and O₃ was adversely correlated with pregnancy outcomes in fresh IVF cycles, and the associations were modified by air temperature, relative humidity, and wind speed. The inverse associations of PM_2.5 and SO₂ exposure with biochemical pregnancy were stronger at lower temperatures and humidity. Negative associations of PM_2.5 with clinical pregnancy were only significant at lower temperatures and wind speeds. Moreover, the effects of O₃ on live birth were enhanced by higher wind speed.

CONCLUSIONS

Our results suggested that the associations between air-pollutant exposure and IVF outcomes were modified by meteorological conditions, especially temperature and wind speed. Women undergoing IVF treatment should be advised to reduce outdoor time when the air quality was poor, particularly at lower temperatures.

Research Trends of Vitamin D Metabolism Gene Polymorphisms Based on a Bibliometric Investigation

Vitamin D requires activation to show its pharmacological effect. While most studies investigate the association between vitamin D and disease, only a few focus on the impact of vitamin D metabolism gene polymorphisms (vitDMGPs). This bibliometric study aims to provide an overview of current publications on vitDMGPs (CYP27B1, CYP24A1, CYP2R1, CYP27A1, CYP2R1, DHCR7/NADSYN1), compare them across countries, affiliations, and journals, and inspect keywords, co-citations, and citation bursts to identify trends in this research field. CiteSpace© (version 6.1.R3, Chaomei Chen), Bibliometrix© (R version 4.1.3 library, K-Synth Srl, University of Naples Federico II, Naples, Italy), VOSviewer© (version 1.6.1, Nees Jan van Eck and Ludo Waltman, Leiden University, Leiden, Netherlands) and Microsoft® Excel 365 (Microsoft, Redmond, Washington, USA) classified and summarized Web of Science articles from 1998 to November 2022. We analyzed 2496 articles and built a timeline of co-citations and a bibliometric keywords co-occurrence map. The annual growth rate of vitDMGPs publications was 18.68%, and their relative research interest and published papers were increasing. The United States of America leads vitDMGPs research. The University of California System attained the highest quality of vitDMGPs research, followed by the American National Institutes of Health and Harvard University. The three productive journals on vitDMGPs papers are J. Steroid. Biochem. Mol. Biol., PLOS ONE, and J. Clin. Endocrinol. Metab. We highlighted that the vitDMGPs domain is relatively new, and many novel research opportunities are available, especially those related to studying single nucleotide polymorphisms or markers in a specific gene in the vitamin D metabolism cycle and their association with disease. Genome-wide association studies, genetic variants of vitDMGPs, and vitamin D and its role in cancer risk were the most popular studies. CYP24A1 and CYB27A1 were the most-studied genes in vitDMGPs. Insulin was the longest-trending studied hormone associated with vitDMGPs. Trending topics in this field relate to bile acid metabolism, transcriptome and gene expression, biomarkers, single nucleotide polymorphism, and fibroblast growth factor 23. We also expect an increase in original research papers investigating the association between vitDMGPs and coronavirus disease 2019, hypercalcemia, Smith-Lemli-Opitz syndrome, 27-hydroxycholesterol, and mendelian randomization. These findings will provide the foundations for innovations in the diagnosis and treatment of a vast spectrum of conditions.

Global trends and current status of distraction osteogenesis: Bibliometric analysis of publications from 1980 to 2021

Introduction: Distraction osteogenesis (DO) has become an important technology for the correction of various congenital and acquired skeletal ridge deformities. It is widely used in oral and maxillofacial surgery, orthopedics, and other disciplines. From 1980 to 2021, the cutting-edge research of DO has been continuously promoted, and the interaction between disciplines has also been deepening. However, the analysis on the global trend and status of DO is relatively rare. Therefore, the aim of our study was to summarize the global trends and current status of DO through bibliometrics. Materials and methods: Web of Science (WOS) core collection database and Medline were used to search DO-related literatures published during 1980-2021. The collected data are imported into Microsoft Excel, Microsoft Word, VOSviewer software for analysis and drawing figure/table. Results: A total of 7,721 publications were included in this study. The United States is the main contributing country to DO (ranking first in terms of total publications, sum of times cited and H-index). Harvard University was the main contributing institution to DO. Journal of Craniofacial Surgery is the main contributing journal of DO related articles. Buchman, SR is the main contributing author to DO related articles. DO related publications can be summarized into 7 clusters: 1) "mechanism study", 2) "limb bone distraction study", 3) "alveolar bone distraction study", 4) "temporomandibular joint ankylosis study", 5) "maxillofacial surgery study", 6) "skull distraction study" and 7) "mandible distraction study". Mandible distraction study has been a hot topic in recent years. In addition, the "management", "osteogenesis" and "reconstruction" of DO have been the research hotspots from 1980 to 2021. Conclusion: From 1980 to 2021, the total number of DO articles has increased rapidly and maintained a steady trend. The United States is the predominant country in the field. Surgery, dental, and oral surgery and orthopaedics are hot fields of DO research. The study of mandible distraction has been paid more and more attention and will become a hotspot in the future. Our study is beneficial for scientists to specify the research hotspot and development direction of DO.