Nephrology Research Performance of Indian Scientists in Science Citation Index Expanded: A Scientometric Profile

Nephrology is the Greek word nephros means «kidney», (combined with the suffix -logy, «the study of») is a specialty of medicine and pediatrics that concerns itself with the kidneys: deals with the adult and pediatric study of the kidneys and its related diseases [1]. The nephrologists deal with the diagnosis and management of kidney diseases. The kidneys are vital for maintaining normal fluid and electrolyte balance in the body. Nephrologists deal with kidney disorders, including fluid and electrolyte disorders, acid-base disorders, kidney stones, glomerular diseases, tubulointerstitial diseases, mineral metabolism, acute kidney disease, acute renal failure, chronic kidney diseases, chronic renal failure and end stage renal disease and dialysis [2]. They need to be well aware of medications and clinical pharmacology, high blood pressure management, diabetes management and its’ complications, epidemiology of diseases and infections as well as nutritional management for prevention and treatment of kidney related diseases.


Introduction
Nephrology is the Greek word nephros means «kidney», (combined with the suffix -logy, «the study of») is a specialty of medicine and pediatrics that concerns itself with the kidneys: deals with the adult and pediatric study of the kidneys and its related diseases [1]. The nephrologists deal with the diagnosis and management of kidney diseases. The kidneys are vital for maintaining normal fluid and electrolyte balance in the body. Nephrologists deal with kidney disorders, including fluid and electrolyte disorders, acid-base disorders, kidney stones, glomerular diseases, tubulointerstitial diseases, mineral metabolism, acute kidney disease, acute renal failure, chronic kidney diseases, chronic renal failure and end stage renal disease and dialysis [2]. They need to be well aware of medications and clinical pharmacology, high blood pressure management, diabetes management and its' complications, epidemiology of diseases and infections as well as nutritional management for prevention and treatment of kidney related diseases.
Scientometrics is one of the statistical and quantitative techniques which is widely used to identify the research trends in scientific and scholarly communications on any discipline, topic, country, research institutions like IITs, IIMs, Universities, and even any individual scientists, or scholars, etc. According to Glossary of Thompson, 2008, Scientometric is the quantitative study of the disciplines of science based on published literature and communication. It includes identifying emerging areas of scientific research, examining the development of research over time, or geographic and organizational distributions of research. Moreover, Scientometrics is one of the most important measures for the assessment of scientific productions. It is part of the sociology of science and has applications to science policy-making. It involves quantitative studies of scientific activities, others, publications, and overlaps on bibliometrics to some extent [3,4]. Scientific literature is a reflection of scientific activity and productivity [5].
Velmurugan [6] analyzed to identify the publications, trend on fossil fuels in Indian perspective with 943 and its h-index was 73 and average citations per item was 28.63, total sum of times cited was 26,997, without self citations was 26,159, citing articles was 21,694, without self citations was 21,324 scores. The results showed that there was no such a study carried out on Fossil Fuel towards the scientific publication research retrieved from the Web of Science bibliometric database using Scientometric tools and techniques so far. Further, Indian Journal of Biotechnology [7], Phytochemistry [8,9], Nanotechnology [10] research have been carried out in recent years to observe the various parameters. This study has been carried out Nephrology literature to investigate the various factors such as research growth, ranking of journals, author productivity, etc.

Objectives of the Study
The major objectives are framed in the present study:

Material and Methods
The data were collected from the Web of Science Core Collection database by using the keywords which are given below: The data were exported to MS Excel spreadsheet to analyze statistically and tabulated and figured. This study covers a period of five years from 2011 to 2016 (both the years inclusive). All the records during the period of study have been downloaded completely from the Web of Science online database. The researcher has applied percentage analysis and average score analysis as the basic tools. Apart from the above the specific bibliometric statistical tools such as Collaborative index, Degree of Collaboration, R2 value and Mean, Standard Deviation, C.V and softwares such as HistCite, VOS Viewer have also been applied.

Data Analysis
Year-wise growth on Nephrology Table 1 shows that out of 2622 research papers, the highest number of papers, i.e. 510 (19.5%) scholarly publications along with 1707 Total Global Citation Score and 185 Total Local Citation Score which is ranked in first in 2014. The lowest number, i.e. 382 (14.6%) research output with 3098 Total Global Citation Score (TGCS) and the Total Local Citation Score (TLCS) is 365 in the year 2011. It is identified that the average number of research articles was 437 and standard deviation and coefficient variance has also been calculated during the period of study. Table 2 indicates types of literature output in the forms of research Article, Review, Editorial Material, Meeting Abstracts, Letters, Article; Proceedings Paper News Item, Biographical-Item, Correction, Article; Book Chapter and Review; Book Chapter. Based on the analysis, the result shows that out of 2622, the majority of (69.5%) papers from journal articles with 9151 global citations has been placed in first position and followed by 304(11.6%) reviews, 230(8.8%) editorial material, 165(6.3%) meeting abstract, 41(1.6%) letter, 25(1.0) proceeding papers, 11(0.4) News items, 9(0.3) Bibliographic item, 9(0.3) Correction, 3(0.1) Article; book chapters, 2(0.1) Reviews; book chapter were found during the study period. It is interesting to note that based on the global citation score in the field of Nephrology; review manuscript has been placed in first position with 9151 TGCS, and followed by articles with 2234 TGCS which has occupied in the second place. It is noticed that most of the manuscript has cited in the form of articles globally. When as compared with documents, there is a significant between journal articles and other document.

Language Wise Research Output
It is identified in the language wise research output in the field of Nephrology for the present study. The languages such as English, Spanish, French, German, Portuguese, Polish, Russian, Italian, Serbian, Korean, Turkish, and Rumanian have been used in which the highest numbers of (91.0%) articles with11713 TGCS are published in the English language which is the predominant and followed by Spanish articles are in the second position with 120(4.6%) and the small amount of articles are written in, Turkish , Korean, Serbian and Italian (each 0.1%) languages. Table 3 shows that out of 380, researcher has selected only top 25 predominant institutions for the present study. To view this, the highest number of (3.4%) literature output with 620 total global citations contributed by University of Amsterdam Research Center has occupied the first position and followed by the same record count contributed by unknown contributors and Mayo Clinical which contributed 12 articles each with a different citation score such as 29 and 43 respectively.

Geographical Wise Production
It can be observed from Table 4 that 108 countries have contributed in the field of Nephrology during the period of 6 years. Out of 108 countries, USA has been placed with 845 research output and the percentage rate is 32.2 and also the global citation score is 5306 and has got the first place based on the record count and followed by Italy, which has 216 records with a 1634 global citation score and occupied the second rank, Canada got next position with 206 articles with a 1912 citation score, and followed by the UK has 202 records with a 1732 citation score globally which is ranked fourth. It is found that the USA has been placed in first place based on the majority of citation score, i.e. 5036 which got Canada has been ranked in the second position with a 1912 citation score and followed by the UK got placed in the third position with a 1732 citation score. Based on the above analysis, there is a significant relationship between institution and country production during the period of study.   It is observed from the Table 5 that about 90% of papers was contributed by multi authors. Out of 633 papers, the highest number of papers was published by double authors which accounts for 203(32.07%) followed by three authored articles which lead 198(31.28%.) 17.38% of articles were published by four authors. Table 6 represents that out of 2622 articles the maximum number publications 86.15% were done by joint authors while the rest 363(13.85%) papers were contributed by single authors. It is found that the majority of the articles has been contributed only by solo author. The Table 6 also shows the degree of collaboration (DC) on authorship in the field of Nephrology during the period of study. It is very clear that the percentage of single authored is more than multi-authored papers. To estimate the degree of collaboration in quantitative terms, the formula given by K Subramanyam [11] was used. The degree of collaboration ranges from 0.79 to 0.91 and the average degree of collaboration is 0.86.

Pattern of Collaborative Index
It is identified from the Table 7 Table 8 shows that top 12 ranking of journals according to their productivity. Six journals have published 2622 articles. The American Journal of Kidney Diseases was ranked first (global citation score) 1101(5.5%), The Nephrology Dialysis Transplantation is in the second rank (global citation score) 765(5.5%), The Clinical Journal of the American Society of Nephrology got ranked third (global citation 1324) (5.3%) during the period of study. The Pediatric Nephrology was placed fourth (global citation score) 404(5.0%) articles during the period of study.

Most Productive Keywords
It was also measured to know about the most productive keywords on Nephronology research output during the study period. Out of 4702 words; researchers have considered the top 15 words for research purpose. It was noted hat the majority of the papers (32.1%) with TLCS is 566 and TGCS is 2093 which got placed in the first position for being used the word ''NEPHROLOGY'', followed by ''KIDNEY'' with 671 papers

Conclusion
Scientometric analysis computes to a scientific publication which has highlighted the contribution of institutions, journals, and individual researchers. This study has been carried on Research productivity of Indian Scientists on Nephrology from 2011 to 2016. The data were collected from web of science database by using the document search provision in science citation index and analyzed through HistCite software. It was measured that the highest (19.5%) of papers were published in 2014 and the collaborative research has also been measured in the field of Nephrology in terms of literature output. The USA has maximum number of literature output, which is 32.2% with 5306 total global citations and it ranks in the first position. The degree of collaboration (DC) was determined among the productivity authors. The percentage of multi-authored is more than that of single-authored papers and the average degree of collaboration was 0.86. The pattern of collaborative index was evaluated and the maximum range of collaborative index was 0.19 in the years 2011 respectively. It is concluded that the scholarly communications in Nephrology have been increasing year by year at a substantial rate.