A bibliometric analysis of COVID-19 publications in the ten psychology-related Web of Science categories in the social science citation index.

OBJECTIVE: The aim of this study was to analyze the characteristics of the COVID-19 publications in the ten psychology-related Web of Science categories in the social science citation index 10-month following the COVID-19 outbreak. METHODS: Six publication indicators were examined across authors, institutions, and countries. RESULTS: Analyses showed that the United States has produced the highest number of empirical investigations into the psychological impact of COVID-19, and the majority of the research across all countries was in clinical and psychopathology. Distribution of journals and psychology-related Web of Science categories were analyzed. Frequently used words in article title, author keywords, and KeyWords Plus were also presented. CONCLUSIONS: The findings suggest that there are substantial clinical implications associated with COVID-19. There are recommendations offered for future research and clinical practice.

Biocontrol of Tomato Bacterial Wilt by Foliar Spray Application of a Novel Strain of Endophytic Bacillus sp.

The aim of the present study was to identify a strain of endophytic Bacillus species that control tomato bacterial wilt by foliar spray application. Fifty heat-tolerant endophytic bacteria were isolated from the surface-sterilized foliar tissues of symptomless tomato plants that had been pre-inoculated with the pathogen Ralstonia pseudosolanacearum. In the primary screening, we assessed the suppressive effects of a shoot-dipping treatment with bacterial strains against bacterial wilt on tomato seedlings grown on peat pellets. Bacillus sp. strains G1S3 and G4L1 significantly suppressed the incidence of tomato bacterial wilt. In subsequent pot experiments, the biocontrol efficacy of foliar spray application was examined under glasshouse conditions. G4L1 displayed consistent and significant disease suppression, and, thus, was selected as a biocontrol candidate. Moreover, the pathogen population in the stem of G4L1-treated plants was markedly smaller than that in control plants. A quantitative real-time PCR analysis revealed that the foliar spraying of tomato plants with G4L1 up-regulated the expression of PR-1a and LoxD in stem and GluB in roots upon the pathogen inoculation, implying that the induction of salicylic acid-, jasmonic acid-, and ethylene-dependent defenses was involved in the protective effects of this strain. In the re-isolation experiment, G4L1 efficiently colonized foliar tissues for at least 4| |weeks after spray application. Collectively, the present results indicate that G4L1 is a promising biocontrol agent for tomato bacterial wilt. Furthermore, to the best of our knowledge, this is the first study to report the biocontrol of bacterial wilt by the foliar spraying with an endophytic Bacillus species.

Potential Use of L-arabinose for the Control of Tomato Bacterial Wilt.

The present study aimed to investigate the potential of simple sugars for use as protection agents in the control of tomato bacterial wilt caused by Ralstonia pseudosolanacearum. Based on the sugar assimilation patterns of the pathogen, four unassimilable sugars (L-arabinose, maltose, D-raffinose, and D-ribose) were selected from 10 representative sugars present in tomato root exudates. These sugars were evaluated for their effects on bacterial wilt using a tomato seedling bioassay. The application of 0.25% L-arabinose significantly reduced disease severity and was, thus, selected as a candidate for further evaluations in a pot experiment under glasshouse conditions. The results obtained showed that the disease suppressive effects of L-arabinose slightly increased at higher concentrations; drench treatments at 0.1, 0.25, and 0.5% reduced disease severity by ca. 48, 70, and 87%, respectively. The drench treatment with 0.5% L-arabinose significantly reduced the pathogen population in the rhizosphere and stem tissues of tomato plants without any antibacterial activity. Real-time reverse-transcription PCR revealed that the expression of salicylic acid-dependent and ethylene-dependent defense genes was significantly enhanced in the stem tissues of L-arabinose-treated tomato plants following the pathogen inoculation. These results suggest that soil drenching with L-arabinose effectively suppresses tomato bacterial wilt by preventing pathogen proliferation in the rhizosphere and stem tissues of tomato plants. This is the first study to report the potential of L-arabinose as a safe, eco-friendly, and cost-effective plant protection agent for the control of tomato bacterial wilt.

Global performance and development on sustainable city based on natural science and social science research: A bibliometric analysis.

Sustainable city has been a global concern in recent years, involving natural science and social science research. However, few studies have attempted to map the global research of sustainable city. This study aimed to reveal the global performance and development of sustainable city research during 1992 to 2016, using a bibliometric analysis based on Science Citation Index Expanded (SCI-EXPANDED) and Social Sciences Citation Index (SSCI) on Web of Science. Research performance, research emphases and trends were illustrated by bibliometric indicators and newly developed visualization tools, like Science of Science (Sci2), Gephi, and alluvial diagram. Sustainable city research in natural science and social science were well-matched in quantity, and had similar and different characteristics in terms of different investigated aspects. China ranked first in natural science research, while the USA was the leading country in social science research. More categories and clusters were involved in sustainable city field, indicating more interdisciplinary integration was undergoing. Energy and fuels in natural science field, and interdisciplinary applications mathematics in social science field started to attract more attention. Statistical analysis of words in title, author keywords, and KeyWords Plus has been investigated to monitor the development of sustainable city research. Finally, three critical issues in sustainable city research based on the clues by the analysis of these keywords were reviewed and discussed.

Global development and trend of wind tunnel research from 1991 to 2014: a bibliometric analysis.

Development and trend of global wind tunnel research from 1991 to 2014 were evaluated by bibliometric analysis. Based on the statistical data from Science Citation Index Expanded from Web of Science, publication performance of wind tunnel research was analyzed from various aspects, including publication output, category distributions, journals, countries, institutions, leading articles, and words analysis. The results show that scientific articles associated with wind tunnel increased dramatically, with Journal of Wind Engineering and Industrial Aerodynamics as the most productive journal. The USA has been leading in publication output since 1991, while China has become a new-rising force of wind tunnel research. NASA was the dominant institution in wind tunnel field which published most single institution articles and nationally and internationally collaborative articles. The citation lifecycles of the leading articles exhibited different patterns of their trends, but all reached a plateau in certain years. Based on synthesized analysis of title words, abstract words, author keywords, and KeyWords Plus, computational fluid dynamic (CFD) was found to be a hot issue, which needs experimental validation by wind tunnels. Wind loads and wind turbine also caused increasing attentions while lepidoptera and sex pheromone were less studied. In the wind tunnel articles, numerical simulation of CFD was increasingly mentioned while field measurement showed minor change, suggesting the rapid developments of CFD.

Highly cited articles in wind tunnel-related research: a bibliometric analysis.

Wind tunnels have been widely employed in aerodynamic research. To characterize the high impact research, a bibliometric analysis was conducted on highly cited articles related to wind tunnel based on the Science Citation Index Expanded (SCI-EXPANDED) database from 1900 to 2014. Articles with at least 100 citations from the Web of Science Core Collection were selected and analyzed in terms of publication years, authors, institutions, countries/territories, journals, Web of Science categories, and citation life cycles. The results show that a total of 77 highly cited articles in 37 journals were published between 1959 and 2008. Journal of Fluid Mechanics published the most of highly cited articles. The USA was the most productive country and most frequent partner of internationally collaboration. The prolific institutions were mainly located in the USA and UK. The authors who were both first author and corresponding author published 88% of the articles. The Y index was also deployed to evaluate the publication characteristics of authors. Moreover, the articles with high citations in both history and the latest year with their citation life cycles were examined to provide insights for high impact research. The highly cited articles were almost earliest wind tunnel experimental data and reports on their own research specialty, and thus attracted high citations. It was revealed that classic works of wind tunnel research was frequently occurred in 1990s but much less in 2000s, probably due to the development of numerical models of computational fluid dynamic (CFD) in recent decades.

Cameroon publications in the Science Citation Index Expanded: Bibliometric analysis / Publicaciones de Camerún en el Science Citation Index Expanded: análisis bibliométrico

Resumen Camerún es uno de los seis países de África Central con más de 20 millones de habitantes. Para caracterizar el desempeño de la investigación de Camerún, las publicaciones de los Camerúnes en el Science Citation Index Expanded durante el período de 1936-2015, indexadas en la base de datos Thomson Reuters SCI-EXPANDED, fueron estudiadas en este trabajo. Todos los documentos de ese período con Camerún en el campo de dirección fueron incluidos en el estudio. Se analizaron el tipo de documento, el idioma, la tendencia y las colaboraciones, así como el resultado de diferentes categorías de temas. También se analizaron las interpretaciones de los países, instituciones y autores, incluyendo el total, único, colaborativo, primer autor, y publicaciones de autor correspondientes. Los artículos fueron analizados por la producción científica y los resultados de investigación de individuos, instituciones y países colaborativos con Camerún. Los análisis incluyeron 8 457 artículos (85 % de 10 591 publicaciones de Camerún). Estos análisis bibliométricos de las publicaciones camerunesas aportaron ideas interesantes sobre autores, instituciones y modelos de colaboración. Los resultados mostraron que la investigación en Camerún era altamente dependiente de colaboraciones extranjeras, y la colaboración internacional fue responsable del creciente número de publicaciones a lo largo de los años. Se encontró que los artículos con autores primarios o autores correspondientes de fuera de Camerún obtuvieron más citas que los otros y que los artículos sin ninguna colaboración internacional tenían citas más bajas. El número de artículos indexados por SCI-EXPANDED ha mostrado un aumento en términos de artículos cameruneses que es considerablemente mayor que el aumento en el número de todos los artículos en SCI-EXPANDED. Los artículos eran más frecuentes que otros tipos de publicación y en su mayor parte en inglés. La Universidad de Yaundé I ocupó el primer lugar en artículos de colaboración interinstitucional, el rango de los artículos de colaboración interinstitucional y el rango de los artículos del primer autor y los artículos de autores correspondientes. La Universidad de Yaundé I también estuvo en una posición de liderazgo absoluta desde 1970 hasta 2015, seguida muy de lejos por las otras instituciones. Las categorías de medicina tropical, ciencias vegetales, salud pública ambiental y ocupacional, y enfermedades infecciosas, representaron el mayor número de artículos publicados. Aunque la física y la química dominaron el ranking de los 20 mejores autores cameruneses, un artículo independiente de matemáticas fue el más citado, con 60 citas en 2015 a un autor camerunés. Los tres principales investigadores productivos fueron: T. C. Kofane, B. T. Ngadjui, P. Woafo, todos de la Universidad de Yaundé I. Francia y Estados Unidos dominaron el ranking de países con una fuerte colaboración científica con Camerún.

Abstract Cameroon is one of the six countries of Central Africa with more than 20 000 000 residents. To characterize the Cameroon research performance, Cameroonians publications in the Science Citation Index Expanded during the period of 1936-2015, indexed in the Thomson Reuters SCI-EXPANDED database, were studied in this work. All documents of that period with Cameroon in the address field were included in the study. The document type, language, trend and collaborations were analyzed, as well as the output of different subject categories. Performances of countries, institutions and authors, including total, single, collaborative, first author, and corresponding author publications were also analyzed. Articles were analyzed by the scientific output and research performances of individuals, institutions and collaborative countries with Cameroon. Analyses included 8 457 articles (85 % of 10 591 Cameroonian publications). These bibliometric analyses of Cameroonian publications provided interesting insights concerning authors, institutions and collaboration patterns. Results showed that research in Cameroon was highly dependent on foreign collaborations, and the international collaboration was responsible for the increasing number of publications over the years. It was found that the articles with either first authors or corresponding authors from outside Cameroon got more citations than the others, and that the articles without any international collaboration had lower citations. The number of articles indexed by SCIEXPANDED has seen an increase in terms of Cameroonian articles that is considerably greater that the increase in number of all articles in SCI-EXPANDED. Articles were more frequent than other types of publication and they were mostly in English. The University of Yaoundé I ranked top one in inter-institutionally collaborative articles, the rank of the total inter-institutionally collaborative articles, and the rank of first author articles and corresponding author articles. The University of Yaoundé I also was in an absolute leading position from 1970s to 2015, followed far away by the other institutions. The categories of tropical medicine, plant sciences, environmental and occupational public health, and infectious diseases, represented the largest number of published articles. Even though physics and chemistry dominated the ranking of the top 20 best Cameroonian authors, an independent mathematics article was the most cited, with 60 citations in 2015 to a Cameroonian author. The top three productive researchers were T. C. Kofane, B. T. Ngadjui, P. Woafo, all from University of Yaoundé I. France and the USA dominated the ranking of countries with strong scientific collaboration with Cameroon.

Characteristics and trends on global environmental monitoring research: a bibliometric analysis based on Science Citation Index Expanded.

A bibliometric analysis based on the Science Citation Index Expanded from Web of Science was carried out to provide insights into research activities and trends of the environmental monitoring from 1993 to 2012. Study emphases covered publication outputs, language, categories, journals, countries/territories, institutions, words, and hot issues. The results indicated that the annual output of environmental monitoring publications increased steadily. The environmental sciences and analytical chemistry were the two most common categories. Environmental Monitoring and Assessment published the most articles. The USA and the UK ranked in the top two in terms of all five indicators. The U.S. Environmental Protection Agency took the leading position of the institutions in terms of publication output. The synthesized analysis by words in title, author keywords, and KeyWords Plus provided important clues for hot issues. Researchers paid more attention on water environment monitoring than other environmental factors. The contaminants including organic contaminants, heavy metal, and radiation were most common research focuses, and the organic contaminants and heavy metal of the degree of concern were gradually rising. Sensor and biosensor played an important role in the field of environmental monitoring devices. In addition to conventional device detection method, the remote sensing, GIS, and wireless sensor networks were the mainstream environmental monitoring methods. The international organization, social awareness, and the countries' positive and effective political and policies promoted the published articles.

Research trends and hotspots related to ammonia oxidation based on bibliometric analysis.

Ammonia oxidation is the rate-limiting and central step in global biogeochemistry cycle of nitrogen. A bibliometric analysis based on 4314 articles extracted from Science Citation Index Expanded database was carried out to provide insights into publication performances and research trends of ammonia oxidation in the period 1991-2014. These articles were originated from a wide range of 602 journals and 95 Web of Science Categories, among which Applied and Environmental Microbiology and Environmental Sciences took the leading position, respectively. Furthermore, co-citation analysis conducted with help of CiteSpace software clearly illustrated that ammonia-oxidizing bacteria (AOB), ammonia-oxidizing archaea (AOA), and anaerobic ammonia oxidation (anammox) were three dominant research themes. A total of 15 landmark works identified with the highest co-citation frequencies at every 8 years were extracted, which demonstrated that the establishments of culture-independent molecular biotechnologies as well as the discoveries of anammox and AOA played the most significant roles in promoting the evolution and development of ammonia oxidation research. Finally, word cluster analysis further suggested that microbial abundance and community of AOA and AOB was the most prominent hotspot, with soil and high-throughput sequencing as the most promising ecosystem and molecular biotechnology. In addition, application of anammox in nitrogen removal from wastewater has become another attractive research hotspot. This study provides a basis for better understanding the situations and prospective directions of the research field of ammonia oxidation.

Estimating municipal solid waste generation by different activities and various resident groups in five provinces of China.

The quantities and composition of municipal solid waste (MSW) are important factors in the planning and management of MSW. Daily human activities were classified into three groups: maintenance activities (meeting the basic needs of food, housing and personal care, MA); subsistence activities (providing the financial support requirements, SA); and leisure activities (social and recreational pursuits, LA). A model, based on the interrelationships of expenditure on consumer goods, time distribution, daily activities, residents groups, and waste generation, was employed to estimate MSW generation by different activities and resident groups in five provinces (Zhejiang, Guangdong, Hebei, Henan and Sichuan) of China. These five provinces were chosen for this study and the distribution patterns of MSW generated by different activities and resident groups were revealed. The results show that waste generation in SA and LA fluctuated slightly from 2003 to 2008. For general waste generation in the five provinces, MA accounts for more than 70% of total MSW, SA approximately 10%, and LA between 10% and 16% by urban residents in 2008. Females produced more daily MSW than males in MA. Males produced more daily MSW than females in SA and LA. The wastes produced at weekends in MA and LA were far greater than on weekdays, but less than on weekdays for SA wastes. Furthermore, one of the model parameters (the waste generation per unit of consumer expenditure) is inversely proportional to per-capita disposable income of urban residents. A significant correlation between gross domestic product (GDP) and waste generation by SA was observed with a high coefficient of determination.

Mapping of drinking water research: a bibliometric analysis of research output during 1992-2011.

A bibliometric analysis based on the Science Citation Index Expanded from the Web of Science was carried out to provide insights into research activities and tendencies of the global drinking water from 1992 to 2011. Study emphases included performance of publication covering annual outputs, mainstream journals, Web of Science categories, leading countries, institutions, research tendencies and hotspots. The results indicated that annual output of the related scientific articles increased steadily. Water Research, Environmental Science & Technology, and Journal American Water Works Association were the three most common journals in drinking water research. The USA took a leading position out of 168 countries/territories, followed by Japan and Germany. A summary of the most frequently used keywords obtained from words in paper title analysis, author keyword analysis and KeyWords Plus analysis provided the clues to discover the current research emphases. The mainstream research related to drinking water was water treatment methods and the related contaminants. Disinfection process and consequent disinfection by-products attracted much attention. Ozonation and chlorination in disinfection, and adsorption were common techniques and are getting popular. Commonly researched drinking water contaminants concerned arsenic, nitrate, fluoride, lead, and cadmium, and pharmaceuticals emerged as the frequently studied contaminants in recent years. Disease caused by contaminants strongly promoted the development of related research.

Independent research of China in Science Citation Index Expanded during 1980-2011.

The study explores the characteristics of China's independent research articles published from 1980 to 2011, based on the database of Science Citation Index Expanded. The publication outputs of seven major industrialized countries including Canada, France, Japan, Germany, Italy, the UK, and the USA were compared with China. Annual production, field performance, research emphases and trends, top articles, as well as main institutional and individual contributors by its top cited articles were analyzed. Some newly developed indicators related to words in title, author keywords, KeyWords Plus, first author, corresponding author, and Y-index were employed to provide in-depth information on topic and author contributions. Results showed that China has been closing the gap with the USA with the greatest growth, and has stood the second since 2006. Most top cited articles were published in 2000s, made up approximately seven tenths of total articles. Pronounced activities were found in chemistry and physics related categories. The core categories included multidisciplinary chemistry, physical chemistry, multidisciplinary materials science, and applied physics. Moreover, China's performance of nanotechnology and science, especially carbon nanotubes, nanoparticles, nanowires, and nanostructures showed dramatic growth. Six top articles with at least 1000 citations were examined, and were observed to concern medicine, nanotube, and adsorption. In addition, main contributing institutions and authors were also revealed and evaluated. Chinese Academy of Sciences played a dominant role, and Tsinghua University, Peking University and five universities in Hong Kong showed good scientific performance.

The most frequently cited adsorption research articles in the Science Citation Index (Expanded).

The 126 most frequently cited articles published in the adsorption field between 1900 and 2011 were identified and characterized using the Science Citation Index (Expanded). The data analyzed cover a range of publication years, journals, Web of Science categories, authors, institutions, countries/territories, life citation cycle curves, and characteristics of frequently cited articles. The 126 most-frequently-cited articles were each cited an average of 1014 times, ranging from 502 to 9922 citations per article from 1918 to 2006; 80% of these articles were published after 1970. Fifty-five journals were represented, led by the Journal of the American Chemical Society, and followed by Science and Nature. Three categories out of the 35 Web of Science categories constituted 60% of the citations. The three categories were: physical chemistry, multidisciplinary chemistry, and multidisciplinary sciences. Thirteen of the authors contributed three or more articles. Harvard University, the Massachusetts Institute of Technology, and the University of Washington led the list of 107 institutions, while the United States led the list of 17 countries/territories, comprising more than half of the articles. Collaboration among the top authors was a frequent occurrence, while inter-institutional collaboration and national collaboration was not obvious among the topmost articles. Moreover, the citation patterns as a function of time varied widely among the topmost articles. As evidenced by citation life cycles, the well known BET and Langmuir isotherms have received considerable attention during the study period, and will probably continue to be popular in the adsorption field. Some emerging hotspots are likely to receive particular attention in the near future; these include the new family of "M41S" materials, pseudo-second-order kinetic models, and the nudged elastic band method.

Estimating municipal solid waste generation by different activities and various resident groups: a case study of Beijing.

Reliable and accurate determinations of the quantities and composition of wastes is required for the planning of municipal solid waste (MSW) management systems. A model, based on the interrelationships of expenditure on consumer goods, time distribution, daily activities, residents groups, and waste generation, was developed and employed to estimate MSW generation by different activities and resident groups in Beijing. The principle is that MSW is produced by consumption of consumer goods by residents in their daily activities: 'Maintenance' (meeting the basic needs of food, housing and personal care), 'Subsistence' (providing the financial requirements) and 'Leisure' (social and recreational pursuits) activities. Three series of important parameters - waste generation per unit of consumer expenditure, consumer expenditure distribution to activities in unit time, and time assignment to activities by different resident groups - were determined using a statistical analysis, a sampling survey and the Analytic Hierarchy Process, respectively. Data for analysis were obtained from the Beijing Statistical Yearbook (2004-2008) and questionnaire survey. The results reveal that 'Maintenance' activity produced the most MSW, distantly followed by 'Leisure' and 'Subsistence' activities. In 2008, in descending order of MSW generation the different resident groups were floating population, non-civil servants, retired people, civil servants, college students (including both undergraduates and graduates), primary and secondary students, and preschoolers. The new estimation model, which was successful in fitting waste generation by different activities and resident groups over the investigated years, was amenable to MSW prediction.

Model of municipal solid waste source separation activity: a case study of Beijing.

One major challenge faced by Beijing is dealing with the enormous amount of municipal solid waste (MSW) generated, which contains a high percentage of food waste. Source separation is considered an effective means of reducing waste and enhancing recycling. However, few studies have focused on quantification of the mechanism of source separation activity. Therefore, this study was conducted to establish a mathematical model of source separation activity (MSSA) that correlates the source separation ratio with the following parameters: separation facilities, awareness, separation transportation, participation atmosphere, environmental profit, sense of honor, and economic profit. The MSSA consisted of two equations, one related to the behavior generation stage and one related to the behavior stability stage. The source separation ratios of the residential community, office building, and primary and middle school were calculated using the MSSA. Data for analysis were obtained from a 1-yr investigation and a questionnaire conducted at 128 MSW clusters around Beijing. The results revealed that office buildings had an initial separation ratio of 80% and a stable separation ratio of 65.86%, whereas residential communities and primary and middle schools did not have a stable separation ratio. The MSSA curve took on two shapes. In addition, internal motivations and the separation transportation ratio were found to be key parameters of the MSSA. This model can be utilized for other cities and countries.

A bibliometric analysis of solid waste research during the period 1993-2008.

This study is a bibliometric analysis of solid waste research to evaluate the current trends, using the literature in the Science Citation Index (SCI) database from 1993 to 2008. Analyzed aspects included document type, language, and publication output as well as distribution of journals, subject category, countries, institutes, title-words, author keywords, and 'Keywords Plus'. An evaluating indicator, h-index, was applied to characterize the solid waste publications. The trend of publication outputs during 1993-2008 coincided with a power and an exponential model. Based on the exponential model during 2001-2008, the number of articles on solid waste in 2013 is predicted to be twice that in 2008. The most common subject category is environmental science and the most productive journal is Waste Management. The USA with most publications and China with the highest growth rate were compared. Finally, author keywords, words in title, and 'Keywords Plus' were analyzed to provide research emphasis. The results showed that mainstream research was centered on the following methods: recycling, landfilling, composting and waste-to-energy. Heavy metals, fly ash and sewage sludge were considered recent research hotspots.