A historical review and bibliometric analysis of research on estuary pollution

Microplastics: A potential proxy for tracing extreme flood events in estuarine environments

The transport of microplastics (MPs) is susceptible to being influenced by catchment hydrology; however, there is a notable lack of research on their retention and responses to flood events in estuarine sedimentary records. Herein, we collected two cores in the Yangtze Estuary to explore their microplastic pollution, influencing factors and linkage to flood events. MP abundance exhibited a decreasing trend from the top to the bottom in both cores. Both plastic production and sediment mean grain size showed a significant positive correlation with MP abundance. The sedimentary record displayed a marked surge in MP abundance during the extreme flood period, suggesting a direct influence of flooding on MP deposition. The resuspension of upstream MPs and erosion of land-based MPs by heavy rain might be responsible for this increase. Furthermore, our study identified significant periodicities in MP abundance, closely aligned with the hydrological patterns of the Yangtze River. This study highlights the role of floods in fluvial MP distribution and proposes MPs as a proxy of extreme floods from the 20th century in estuarine environments.

Uncovering the world's largest carbon sink-a profile of ocean carbon sinks research

As the world's largest carbon sink, the oceans are essential to achieving the 1.5 °C target. Marine ecosystems play a crucial role in the "sink enhancement" process. A deeper comprehension of research trends, hotspots, and the boundaries of ocean carbon sinks is necessary for a more effective response to climate change. To this end, academic literature in the field of ocean carbon sinks was investigated and analyzed using the core database of the Web of Science. The results show that (1) The ocean carbon sink is a global study. The number of literatures in the field of ocean carbon sinks is growing, and the USA and China are the main leaders, with the USA accounting for 31.19% of the global publications and China accounting for 26.57% of the global publications, and the environmental science discipline is the most popular in this field. (2) Keyword burst detection shows that the keywords "sink, sensitivity, land, dynamics, and seagrass" appear earliest and have high burst intensity, which are the hot spots of research in this field; the keyword clustering shows that the global ocean carbon sinks research mainly focuses on three themes: (i) carbon cycle and climate change; (ii) carbon sinks estimation models and techniques; and (iii) carbon sinks capacity and ocean biological carbon sequestration in different seas. Finally, targeted research recommendations are proposed to further match the ocean carbon sink research.

Global trends in research related to functional dyspepsia and anxiety or depression over the past two decades: a bibliometric analysis

Background and purpose

Functional dyspepsia (FD) is a prevalent global disorder of the upper digestive tract characterized by functional impairment. It often coexists with anxiety/depression, significantly impairing occupational productivity and overall quality of life. This study aimed to identify emerging patterns and prominent themes within FD and anxiety/depression research through bibliometric analysis to help explore new innovative avenues for investigating this type of FD.

Methods

A comprehensive review of literature encompassing FD and anxiety/depression was conducted using the Science Citation Index Extension of the Web of Science Core Collection from 2003 to 2023. Information extracted comprised "Full Record and Cited References." Bibliometric analysis of relevant publications, including country, institution, author, journal, citations, and keywords, was conducted using CiteSpace, VOSviewer, and Bibliometrix package in R and Excel.

Results

Studies related to FD and anxiety/depression have demonstrated an ascending trajectory since 2003. Our bibliometric analysis identified 338 studies published by 2023. NEUROGASTROENTEROLOGY AND MOTILITY emerged as the most prolific journal, while GASTROENTEROLOGY retained pre-eminence within the top 10 published journals. China emerged as the most prolific country, with two institutions within the top 10 in terms of volume of publications. The Mayo Clinic stood as the foremost institution in terms of publication volume, with the Chengdu University of Traditional Chinese Medicine exhibiting robust collaborative engagement. Eminent author influence was attributed to Talley NJ of Newcastle University, Australia. Clusters of extensively cited papers and prevalent keywords delineate the status and trend of FD and anxiety/depression research. This encompasses FD, anxiety, depression, sleep disorders, and functional gastrointestinal disorders. Furthermore, the timeline view map or trend-term analysis suggested that duodenal low-grade inflammation ("duodenal eosinophilia" and "mast cells") might be a new concern associated with FD and anxiety/depression.

Conclusion

Employing bibliometric analysis, this study revealed prevalent focal areas and new trends within FD and anxiety/depression research. These insights serve as valuable guidance for scholars seeking to delve into new research avenues.

Challenges towards the Sustainability and Enhancement of the Indian Sundarban Mangrove's Blue Carbon Stock

The Sundarban is the world's largest contiguous mangrove forest and stores around 26.62 Tg of blue carbon. The present study reviewed the factors causing a decline in its blue carbon content and poses a challenge in enhancing the carbon stock of this region. This review emphasized that recurrent tropical cyclones, soil erosion, freshwater scarcity, reduced sediment load into the delta, nutrient deficiency, salt-stress-induced changes in species composition, mangrove clearing, and anthropogenic pollution are the fundamental drivers which can potentially reduce the total blue carbon stock of this region. The southern end of the Ganges-Brahmaputra-Meghna Delta that shelters this forest has stopped its natural progradation due to inadequate sediment flow from the upper reaches. Growing population pressure from the north of the Sundarban Biosphere Reserve and severe erosion in the southern end accentuated by regional sea-level rise has left minimal options to enhance the blue carbon stock by extending the forest premises. This study collated the scholarly observations of the past decades from this region, indicating a carbon sequestration potential deterioration. By collecting the existing knowledge base, this review indicated the aspects that require immediate attention to stop this ecosystem's draining of the valuable carbon sequestered and, at the same time, enhance the carbon stock, if possible. This review provided some key recommendations that can help sustain the blue carbon stock of the Indian Sundarban. This review stressed that characterizing the spatial variability of blue carbon with more sampling points, catering to the damaged trees after tropical cyclones, estuarine rejuvenation in the upper reaches, maintaining species diversity through afforestation programs, arresting coastal erosion through increasing sediment flow, and combating marine pollution have become urgent needs of the hour. The observations synthesized in this study can be helpful for academics, policy managers, and decision makers willing to uphold the sustainability of the blue carbon stock of this crucial ecosystem.

The global research of microbiota in colorectal cancer screening: a bibliometric and visualization analysis

Aims

We conducted bibliometric and visualization analyses to evaluate the current research status, hotspots, and trends related to the human microbiota markers in colorectal cancer screening.

Methods

The related studies were acquired from the Web of Science Core Collection (WoSCC) database on 5 January 2023. Analyses of the co-occurrence and cooperation relationships between the cited authors, institutions, countries/regions, cited journals, cited articles, and keywords in the studies were carried out using CiteSpace 5.8.R3 software and the Online Analysis platform of Literature Metrology. Additionally, relevant knowledge graphs were drawn to perform visualization analyses; a keywords cluster analysis and a burst analysis were also conducted.

Results

After analyzing 700 relevant articles, this bibliometric analysis found that the annual publications showed an increasing trend from 1992 to 2022. Yu Jun from the Chinese University of Hong Kong had the highest cumulative number of publications, whereas Shanghai Jiao Tong University was the most productive institution. China and the USA have contributed the largest number of studies. The keywords frequency analysis demonstrated that "colorectal cancer," "gut microbiota," "Fusobacterium nucleatum," "risk," and "microbiota" were the most frequent keywords, and the keywords cluster analysis found that the current hotspots were as follows: (a) the precancerous lesions of colorectal cancer (CRC) that need to be screened, such as inflammatory bowel disease (IBD) and advanced adenoma, (b) the gut-derived microbiome for CRC screening, and (c) the early detection of CRC. The burst analysis further showed that the combination of microbiomics with metabolomics might be the future research trend in the field of CRC screening.

Conclusion

The findings of the current bibliometric analysis firstly provide an insight into the current research status, hotspots, and future trends in the field of CRC screening based on the microbiome; the research in this field is becoming more in-depth and diversified. Some human microbiota markers, especially "Fusobacterium nucleatum," are promising biomarkers in CRC screening, and a future hotspot might be the combined analysis of microbiomics and metabolomics for CRC risk screening.

The interaction between microbiota and immune in intestinal inflammatory diseases: Global research status and trends

Aims

This study aimed to conduct a bibliometric analysis of the relevant literature on the interaction between microbiota and immune in intestinal inflammatory diseases, and show its current status, hotspots, and development trends.

Methods

The related literature was acquired from the Web of Science Core Collection on October 12, 2022. Co-occurrence and cooperation relationship analysis of authors, institutions, countries, references, and keywords in the literature were carried out through CiteSpace 6.1.R3 software and the Online Analysis platform of Literature Metrology. At the same time, the relevant knowledge maps were drawn, and the keywords cluster analysis and emergence analysis were performed.

Results

3,608 related publications were included, showing that the number of articles in this field is increasing year by year. The results showed that Gasbarrini A and Sokol H were the authors with the highest cumulative number of articles with 25, and the institution with the most articles was Harvard University with 142 articles. The USA was far ahead in the article output, with 1,131 articles, and had a dominant role, followed by China with 707 articles. The journal Frontiers in Immunology contributed the most to this research field with 213 articles. In the cooperation network analysis, the USA, Harvard University, and Xavier RJ were the most widely collaborated country, institution, and author, respectively, which implied a high level of influence. Keywords analysis showed that there were 770 keywords, which were mainly classified as internal related diseases, such as "inflammatory bowel disease", "irritable bowel syndrome", "colorectal cancer", and the mechanism of interaction of microbiota and immune, such as "intestinal microbiota", "commensal microbiota", "regulatory T cell", "dendritic cell", "barrier function", "activation", "anti-inflammatory properties", "intestinal epithelium", and "diversity". Emerging analysis showed that future research hotspots and trends might be the short-chain fatty acid, gut dysbiosis, gut-liver axis, and fusobacterium nucleatum.

Conclusion

This research was the first bibliometric analysis of publications in the field of interaction between microbiota and immune in intestinal inflammatory diseases using visualization software and data information mining, and obtained the current status, hotspots, and development of this field, which provides a theoretical basis for its scientific research.

Research hotspot and trend analysis in the diagnosis of inflammatory bowel disease: A machine learning bibliometric analysis from 2012 to 2021

Aims

This study aimed to conduct a bibliometric analysis of the relevant literature on the diagnosis of inflammatory bowel disease (IBD), and show its current status, hot spots, and development trends.

Methods

The literature on IBD diagnosis was acquired from the Science Citation Index Expanded of the Web of Science Core Collection. Co-occurrence and cooperation relationship analysis of authors, institutions, countries, journals, references, and keywords in the literature were carried out through CiteSpace software and the Online Analysis platform of Literature Metrology. At the same time, the relevant knowledge maps were drawn, and the keywords cluster analysis and emergence analysis were performed.

Results

14,742 related articles were included, showing that the number of articles in this field has increased in recent years. The results showed that PEYRIN-BIROULET L from the University Hospital of Nancy-Brabois was the author with the most cumulative number of articles. The institution with the most articles was Mayo Clin, and the United States was far ahead in the article output and had a dominant role. Keywords analysis showed that there was a total of 818 keywords, which were mainly focused on the research of related diseases caused or coexisted by IBD, such as colorectal cancer and autoimmune diseases, and the diagnosis and treatment methods of IBD. Emerging analysis showed that future research hotspots and trends might be the treatment of IBD and precision medicine.

Conclusion

This research was the first bibliometric analysis of publications in the field of IBD diagnosis using visualization software and data information mining, and obtained the current status, hotspots, and development of this field. The future research hotspot might be the precision medicine of IBD, and the mechanism needed to be explored in depth to provide a theoretical basis for its clinical application.

The bibliometric analysis and visualization mapping of net environmental benefit analysis (NEBA)

This paper aims to determine the worldwide research trends on searching queries of "oil spill* and risk assessment*" and "net environmental benefit analysis" and its most productive authors and journals. A bibliometric approach was performed to analyze publications including highly cited papers and only papers that were published in the Dimensions database from 2000 to 2022, April was selected. The necessary data were extracted from the Dimensions database and processed using visualization and mapping software such as VOSviewer 1.6.17 and Tableau Public 2021.1. The findings identified significant study fields, co-cited authors, country contributions, productive journals, as well as the most cited authors' articles. This study contributes significantly to the relevant studies as one of the few that utilizes bibliometric analysis as a network visualization and mapping technique for the analysis of one of the primary oil spill response decision-making tools and risk assessment sciences. The findings of this study can assist the researcher perform their research more effectively by providing insight into journal selection, contributing authors, research trends, countries, and keywords. Further research is recommended in light of longer period data contained in oil spill response strategies, oil spill modeling, or oil spill risk subjects.

The General Growth Tendency: A tool to improve publication trend reporting by removing record inflation bias and enabling quantitative trend analysis

The trend of the number of publications on a research field is often used to quantify research interest and effort, but this measure is biased by general publication record inflation. This study introduces a novel metric as an unbiased and quantitative tool for trend analysis and bibliometrics. The metric was used to reanalyze reported publication trends and perform in-depth trend analyses on patent groups and a broad range of field in the life-sciences. The analyses confirmed that inflation bias frequently results in the incorrect identification of field-specific increased growth. It was shown that the metric enables a more detailed, quantitative and robust trend analysis of peer reviewed publications and patents. Some examples of the metric’s uses are quantifying inflation-corrected growth in research regarding microplastics (51% ± 10%) between 2012 and 2018 and detecting inflation-corrected growth increase for transcriptomics and metabolomics compared to genomics and proteomics (Tukey post hoc p<0.0001). The developed trend-analysis tool removes inflation bias from bibliometric trend analyses. The metric improves evidence-driven decision-making regarding research effort investment and funding allocation.

A Bibliometric Analysis of Research on Selenium in Drinking Water during the 1990-2021 Period: Treatment Options for Selenium Removal

A bibliometric analysis based on the Scopus database was carried out to summarize the global research related to selenium in drinking water from 1990 to 2021 and identify the quantitative characteristics of the research in this period. The results from the analysis revealed that the number of accumulated publications followed a quadratic growth, which confirmed the relevance this research topic is gaining during the last years. High research efforts have been invested to define safe selenium content in drinking water, since the insufficient or excessive intake of selenium and the corresponding effects on human health are only separated by a narrow margin. Some important research features of the four main technologies most frequently used to remove selenium from drinking water (coagulation, flocculation and precipitation followed by filtration; adsorption and ion exchange; membrane-based processes and biological treatments) were compiled in this work. Although the search of technological options to remove selenium from drinking water is less intensive than the search of solutions to reduce and eliminate the presence of other pollutants, adsorption was the alternative that has received the most attention according to the research trends during the studied period, followed by membrane technologies, while biological methods require further research efforts to promote their implementation.

Bioremediation of PAHs and heavy metals co-contaminated soils: Challenges and enhancement strategies

Systemic studies on the bioremediation of co-contaminated PAHs and heavy metals are lacking, and this paper provides an in-depth review on the topic. The released sources and transport of co-contaminated PAHs and heavy metals, including their co-occurrence through formation of cation-π interactions and their adsorption in soil are examined. Moreover, it is investigated that co-contamination of PAHs and heavy metals can drive a synergistic positive influence on bioremediation through enhanced secretion of extracellular polymeric substances (EPSs), production of biosynthetic genes, organic acid and enzymatic proliferation. However, PAHs molecular structure, PAHs-heavy metals bioavailability and their interactive cytotoxic effects on microorganisms can exert a challenging influence on the bioremediation under co-contaminated conditions. The fluctuations in bioavailability for microorganisms are associated with soil properties, chemical coordinative interactions, and biological activities under the co-contaminated PAHs-heavy metals conditions. The interactive cytotoxicity caused by the emergence of co-contaminants includes microbial cell disruption, denaturation of DNA and protein structure, and deregulation of antioxidant biological molecules. Finally, this paper presents the emerging strategies to overcome the bioavailability problems and recommends the use of biostimulation and bioaugmentation along with the microbial immobilization for enhanced bioremediation of PAHs-heavy metals co-contaminated sites. Better knowledge of the bioremediation potential is imperative to improve the use of these approaches for the sustainable and cost-effective remediation of PAHs and heavy metals co-contamination in the near future.

Indigenous Forestry Tourism Dimensions: A Systematic Review

Tourism activities developed in forested areas are a non-wood forest exploitation method that contributes to sustainability objectives, even more so when they consider the participation of the community and the government in favor of its conservation. Under this context, this article will review the different investigations that relate to indigenous tourism, the conservation of the ecosystem and what attributes are important when measuring them. To do this, a scientometric meta-analysis was carried out, which extracts a set of articles that strictly refer to the themes of indigenous tourism in forests, considering two databases integrated into the Core Collection Web of Science, the selection process of which is aligned with the guidelines of the PRISMA methodology, establishing, with the PICOS tool, the eligibility criteria of the articles, which were applied to a qualitative systematic review. Finally, a model for measuring attributes in levels on indigenous tourism stands out, which incorporates the limit between the number of visitors to the tourist destination; the incorporation of tourists guides the identification of the necessary infrastructure facilities for an adequate experience and environmental conservation.

Reviewing the effects of contamination on the biota of Brazilian coastal ecosystems: Scientific challenges for a developing country in a changing world

Pollution is a major worldwide problem that is increasing with urban growth, mainly along coastal areas. Pollution is often worse, governance is poorer and managerial strategies to improve environmental quality are less advanced in developing than developed countries. Here, we present an overview of the current scientific knowledge of the impacts of contamination on the biota of coastal ecosystems of Brazil and evaluate the scientific challenges to provide baseline information for local managerial purposes. We compiled data from 323 peer-reviewed published papers from the extensive Brazilian coast. We critically evaluated the produced knowledge (target contaminants, sources, ecosystems, taxa, response variables) and the science behind it (rigour and setting) within its socioenvironmental context (land occupation, use of the coast, sanitation status, contamination history). Research was driven largely by environmental outcomes of industrial development with a focus on the single effects of metals on the biota. The current knowledge derives mainly from laboratory manipulative experiments or from correlative field studies of changes in the biota with varying levels of contamination. Of these, 70% had problems in their experimental design. Environmental impacts have mainly been assessed using standard indicators of populations, mostly in ecotoxicological studies. Benthic assemblages have mostly been studied using structural indicators in field studies. Future assessments of impacts should expand research to more taxonomic groups and ecosystem compartments, adding combined functional and structural responses. Furthermore, further investigations need to consider the interactive effects of contaminants and other environmental stressors. By doing so, researchers would deliver more robust and effective results to solve problems of pollution.

Marine litter: A review of educative interventions

Marine litter is claimed to be one of the most meaningful environmental crises of the century. Education that supports behavior change is a tool to tackle this problem. However, there is a lack of research linking educational initiatives and marine litter issues. A literature review was conducted through a bibliometric and content analysis to explore the state of knowledge regarding educational actions. The results revealed that 2019 was the year with the highest number of publications and that 83.4% of the documents were collaborative efforts. Concerning educational approaches, hands-on and technological activities are being explored to raise awareness and stimulate behavior change. Students and questionnaires represent, respectively, the most common audience and evaluating method. More integrative actions and respective long-term methodological triangulation evaluation were identified as necessary in future studies. This paper is expected to contribute to innovative knowledge in the area by identifying the main gaps in the literature.

A Bibliometric Analysis and Visualization of Current Research Trends in the Treatment of Cervical Spondylotic Myelopathy

STUDY DESIGN

Bibliometric analysis.

OBJECTIVE

Cervical spondylotic myelopathy (CSM) has become the most common cause of spinal cord dysfunction. Many topics of CSM still remain controversial. This study aimed to illustrate the overall knowledge structure and development trends of CSM.

METHODS

Research data sets were acquired from the Web of Science database and the time span was defined as "2000 to 2019." VOS viewer and Citespace software was used to analyze the data and generate visualization knowledge maps. Annual trends of publications, distribution, H-index status, co-authorship status, and research hotspots were analyzed.

RESULTS

A total of 2367 publications met the requirement. The largest number of articles was from the United States, followed by Japan, China, Canada, and India. The highest H-index was found for articles from the United States. The highest number of articles was published in Spine. The cooperation between the countries, institutes, and authors were relatively weak. Cervical sagittal alignment, predictive factor, diffusion tensor imaging, and the natural history of CSM may become a frontier in this research field.

CONCLUSION

The number of publications showed an upward trend with a stable rise. Most of the publications are limited to a few countries and institutions with relatively weak interaction. The United States, Canada, Japan, China, and India have made significant contributions to the field of CSM. The United States is the country with the highest productivity, not only in quality but also in quantity. Cervical sagittal alignment, predictive factor, diffusion tensor imaging, and the natural history of CSM are the research hotspots in the recent years.

How to Measure Environmental Performance in Ports

Oceans, seas, and marine resources are highly relevant for achieving the Sustainable Development Goals. Such relevance has given rise to the blue economy approach, where scholars and policymakers see activities carried out in cargo ports from a different perspective. The blue economy approach stresses the emergence of multiple transnational networks in relation to these topics and the development of green ports plus environmental measurements at seaports in general. In this context, our study aimed to review the various scientifically documented methods for measuring environmental performance in ports, ports companies, or port authorities in the maritime transport and inland waterways framework. The study followed a scientometric meta-analytic methodology to accomplish its goals. The study strictly referred to the Environmental Performance in Ports (EPP) and extracted the corpus to analyze data held in five databases embedded in the Web of Science Core Collection. Then, the selection was processed and refined with the PRISMA guidelines to establish the eligibility criteria for articles with the PICOS (Population, Interventions, Comparators, Outcomes, and Study) tool. A limited study set was identified. This included port environmental performance indicators and studies that were strongly influenced by the European Sea Ports Organization and Green Marine networks. These were compared based on the ecological Sustainable Development Goals (SDGs), scale structure, and diversity in application. Finally, we assessed two measurement forms documented in the scientific research on the subject at a global level and discussed their pros and cons.

Municipal Wastewater: A Sustainable Source for the Green Microalgae Chlorella vulgaris Biomass Production

The need to reduce the costs associated with microalgae cultivation encouraged scientific research into coupling this process with wastewater treatment. Thus, the aim of this work was to assess the growth of Chlorella vulgaris (Chlorophyta) in different effluents from a municipal wastewater treatment plant (WWTP), namely secondary effluent (SE) and sludge run-off (SR). Assays were performed, under the same conditions, in triplicate with 4 dilution ratios of the wastewaters (25%, 50%, 75% and 100%) with the standard culture medium bold basal medium double nitrated (BBM2N) as a control. The capability of C. vulgaris for biomass production, chlorophyll synthesis and nutrients removal in the SE and SR was evaluated. The 25% SE and 25% SR showed increased specific growth rates (0.47 and 0.55 day−1, respectively) and higher biomass yields (8.64 × 107 and 1.95 × 107 cells/mL, respectively). Regarding the chlorophyll content, the 100% SR promoted the highest concentration of this pigment (2378 µg/L). This green microalga was also able to remove 94.8% of total phosphorus of SE, while in 50% SR, 31.2% was removed. Removal of 73.9% and 65.9% of total nitrogen in 50% and 100% SR, respectively, was also observed. C. vulgaris growth can, therefore, be maximized with the addition of municipal effluents, to optimize biomass production, while cleansing the effluents.

A bibliometric analysis: what do we know about metals(loids) accumulation in wild birds?

Metals and metalloids pollution is an important worldwide problem due to the social and ecological effects and therefore has been the subject of many disciplines and the adverse impacts have been documented. In this study, content analysis and trends of studies focused on heavy metal accumulation in birds were presented. For this purpose, a bibliometric network analysis of the studies that use the concepts of "pollution," "heavy metal," and "birds" together in the abstract, keywords, and titles of the papers was carried out. The purpose of choosing this research method was summarizing the relation between birds and environmental pollution in an understandable manner to determine metals(loids) pollution, which become an important environmental problem. Bibliometric data consisting of approximately 971 papers were evaluated with VOSviewer program using the network analysis method to answer the research questions. The results revealed that birds act as bioindicators in the determination of environmental pollution and that the contaminant metals deposited in the various tissues of birds provide preliminary information about environmental pollution. The most of bird studies emphasized that the metal accumulation was mostly in the liver, kidneys, and feathers and the accumulation caused serious problems in most of the vital activities of the birds. The USA is in the leading country in birds-heavy metal studies followed by Spain, Canada, and China. In addition, the mercury (Hg) was the most extensively studied heavy metal in these studies.

Estuarine sediment toxicity testing with an indigenous subtropical amphipod

This study reports on a sediment toxicity test developed with a native amphipod strain of Ptilohyale barbicornis where sediments from 10 estuarine stations along the western coastline of Taiwan were evaluated with respect to trace metals and PAHs. The test was validated by determining dose-response relationships for aqueous copper, and cadmium and sodium dodecyl sulfate as well as copper-spiked sediment, showing a sensitivity of P. barbicornis indicating its capability serving as a toxicity test species. A significant negative correlation between growth effects after 28 days of exposure to field-collected contaminated sediments and PAHs concentrations was observed. Similarly, the chronic toxicity test showed that growth was mostly inhibited compared to controls, body lengths in particular being significantly different from controls (p < 0.05). Various estuarine sediment pollutants in the quality guidelines can be further evaluated using P. barbicornis to understand their comprehensive biological effects and ecological risks.

A Bibliometric Analysis and Visualization of Current Research Trends in Chinese Medicine for Osteosarcoma

BACKGROUND

To illustrate the research framework, overall knowledge structure, and development trends of Chinese medicine (CM) treatment for osteosarcoma (OS) by using a bibliometric analysis and newly developed visualization tools.

METHODS

Research datasets were acquired from the Web of Science (WOS) database from January 1, 1980 to September 30, 2019. VOS viewer and Citespace software was used to analyze the data and generate visualization knowledge maps. Annual trends of publications, distribution of institutes, distribution of journals, citation and H-index status, co-authorship status, research hotspots and co-citation status were analyzed.

RESULTS

A total of 223 publications in the WOS database met the requirement. The number of published articles showed a rise but the citation frequency and the H-index of China were relatively low. The cooperation between the countries, institutes and authors were relatively weak. Most publications were basic researches. Most of the previous researches focused on basic mechanisms of CM in treating OS, and therapy and improvement of dosage form may become a frontier in this research field.

CONCLUSIONS

Compared with other fields, the field of CM treatment for osteosarcome is still in infancy. The distribution of researches is imbalanced and cooperation between countries, institutions and authors remains to be strengthened. Furthermore, basic research occupies an absolute dominant position, and the exploration of the molecular mechanism of CM in preventing and treating OS may become a key point in the future.

Applicability of water quality models around the world-a review

Water quality models are important tools used in the management of water resources. The models are usually developed for specific regions, with particular climates and physical characteristics. Thus, applying these models in regions other than those they were designed for can generate large simulation errors. With consideration to these discrepancies, the goal of this study is to identify the models employed in different countries and assist researchers in the selection of the most appropriate models for management purposes. Published studies from the last 21 years (1997-2017) that discuss the application of water quality models were selected from three engineering databases: SpringerLink, Web of Science, and Scopus. Seven models for water quality simulations have been widely applied around the world: AQUATOX, CE-QUAL-W2, EFDC, QUALs, SWAT, SPARROW, and WASP. The countries most frequently applying water quality models are the USA, followed by China, and South Korea. SWAT was the most used model, followed by the QUAL group and CE-QUAL-W2. This study provides the opportunity for researchers, who wish to study countries with fewer cases of applied water quality models, to easily identify the work from that region. Furthermore, this work collated central themes of interest and the most simulated parameters for the seven countries that most frequently employed the water quality models.

Phytoremediation of Heavy Metal Pollution: A Bibliometric and Scientometric Analysis from 1989 to 2018

This paper aims to evaluate the knowledge landscape of the phytoremediation of heavy metals (HMs) by constructing a series of scientific maps and exploring the research hotspots and trends of this field. This study presents a review of 6873 documents published about phytoremediation of HMs in the international context from the Web of Science Core Collection (WoSCC) (1989–2018). Two different processing software applications were used, CiteSpace and Bibliometrix. This research field is characterized by high interdisciplinarity and a rapid increase in the subject categories of engineering applications. The basic supporting categories mainly included “Environmental Sciences & Ecology”, “Plant Sciences”, and “Agriculture”. In addition, there has been a trend in recent years to focus on categories such as “Engineering, Multidisciplinary”, “Engineering, Chemical”, and “Green & Sustainable Science & Technology”. “Soil”, “hyperaccumulator”, “enrichment mechanism/process”, and “enhance technology” were found to be the main research hotspots. “Wastewater”, “field crops”, “genetically engineered microbes/plants”, and “agromining” may be the main research trends. Bibliometric and scientometric analysis are useful methods to qualitatively and quantitatively measure research hotspots and trends in phytoremediation of HM, and can be widely used to help new researchers to review the available research in a certain research field.

The application of bioturbators for aquatic bioremediation: Review and meta-analysis

Human activities introduce significant contamination into aquatic systems that impact biodiversity and ecosystem function. Many contaminants accumulate, and remediation options are now required worldwide. One method for bioremediation involves the application of macrofauna to stimulate microbial ecosystem processes including contaminant removal. However, if we are to confidently apply such a technique, we need clarity on the effect of bioturbators on different contaminants and how these vary under different environmental scenarios. Here we used a systematic review and meta-analysis to analyse current knowledge on the activities of bioturbating macrofauna in contaminated sediments and quantify how bioturbation-bioremediation changes depend on the taxonomic group, the aquatic ecosystem and important environmental variables. Three common contaminant classes were reviewed and analysed: metals, nutrients (i.e. ammonia and phosphorous) and polycyclic aromatic hydrocarbons (PAH). In addition, meta-regressions were calculated to estimate the effect of environmental and experimental design variables on effect sizes. Meta-analytic results revealed that deeper burrowing and more active sediment surface animals (e.g. polychaetes) increased metal release from sediments, nutrients and oxygen uptake by microbial fractions in comparison to bioturbators that inhabit shallower depths in sediments. In addition, there was a different effect of bioturbators on response variables in different aquatic systems. Finally, bioturbator effects on nutrient and metal release appeared modulated by context-specific variables such as temperature, pH, sediment grain size, animal density and experimental duration. Our findings highlight critical knowledge gaps such as field applications, less studied macrobenthic fauna and the incorporation of molecular approaches. Our results provide the first quantitative synthesis of the effects of bioturbators on contaminant fate and the variables that need to be considered for the optimization of this method as a viable approach for sediment remediation and contaminant management in aquatic systems.

Performance assessment and major trends in open government data research based on Web of Science data

Purpose

The purpose of this paper is to evaluate the global progress and explore research areas and development trends of open government data (OGD) field from the Web of Science (WOS) database by applying the bibliometric visualization approach.

Design/methodology/approach

This paper conducted a bibliometric mapping study on OGD scientific research publications based on WOS from six aspects.

Findings

There are six research perspectives on OGD research. European countries and developed countries pay more attention to OGD movement. The 20 most cited and highly influential research documents were identified. What’s more, the analysis of journals level highlights the interdisciplinary and cross-disciplinary characteristics of OGD research. Current six research topics for OGD research that have been formed and two major emerging research priorities in OGD research fields were identified.

Research limitations/implications

The limitation is that data retrieval result which decided to include only 180 publications in the WOS-indexed publications produced a bias against research publications published in non-WOS publication sources. A fuller research trend would be obtained with the more extensively used electronic databases.

Practical implications

By dint of bibliometric analysis, this paper may be able to quantify research patterns on OGD, to analyze what has been done in this field and to identify the main research hotspots. Therefore, it can aid academic researchers and practicing professionals in contributing to the field more effectively and advancing scientific progress in the field of OGD research.

Social implications

The results can also promote the study on OGD movement in academia, government and industry and also enrich the theory of OGD and provide some new perspectives for research on OGD.

Originality/value

This is the first study to quantify and evaluate global research patterns and development trends in OGD research based on WOS database, which provides a quantitative perspective on OGD studies that may assist in advancing the development of the field.

Environmental regeneration processes in the Anthropocene: The Bilbao estuary case (northern Spain)

This work tackles a multidisciplinary study on the recent sedimentary record of the Bilbao estuary (northern Spain), which is the backbone of a city that was primarily industrial and now is widely recognized as a successful example of urban transformation. Although hotspots of heavily polluted materials still remain at the mouth of the two main tributaries (Galindo and Gobelas), the data obtained confirm the ongoing formation of a new layer of sediments (here called "postindustrial zone") covering historically polluted and azoic deposits. It is characterized by largely variable levels of metals and magnetic susceptibility and moderate-to-high abundances of benthic foraminifera. Monitoring of the evolution of this layer appears a key factor to assess environmental improvement and decision-making in polluted estuaries.

The way forward confronting eco-environmental challenges during land-use practices: a bibliometric analysis

With rapid urbanisation and industrialisation, land-use practice, while satisfying the ever-increasing desires of our material civilisation in the short term, may undermine natural ecosystems on a local, regional and global scale in the long run. Innovative and sustainable land-use practices should be developed in response, so that eco-environmental problems can assessed and dealt with during the whole process of land-use planning, construction, operation, maintenance and management. Using a bibliometric analysis, this study has traced global trends in land-use research from 1992 to 2016, as indexed in the Science Citation Index EXPANDED (SCI-EXPANDED) and the Social Sciences Citation Index (SSCI). A novel method called 'word cluster analysis' has revealed that hotspot analysis is one of the emerging techniques, tools and strategies used to respond to, improve, and protect deteriorating ecosystems during land use. Based on involving various elements, the emerging analytical techniques and tools, including geographical information systems (GIS) and remote sensing, have attracted attention for their ability to assess and solve increasingly serious eco-environmental problems, such as climate change, deforestation, soil erosion, greenhouse gas (GHG) emissions and eutrophication. Ecosystem services, biodiversity conservation, protected areas, and sustainable development are also potential resilience strategies used to confront eco-environmental destruction. The maximum benefits that can be derived from natural ecosystems should be pursued to achieve environmentally sustainable land-use development, strengthening the socio-economy and eco-environment, as well as enhancing the well-being of people and nature.

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.

Global development of the studies focused on antibiotics in aquatic systems from 1945 to 2017

Antibiotics are used to fight diseases in humans and farm animals. Their residues, however, can enter aquatic environments and affect the resistance of non-target microbial strains, and the prevalence of antibiotic resistance genes (ARGs) potentially poses negative impacts on human health. In order to better understand how the studies of antibiotics have been conducted, we analyzed the publications on antibiotics in aquatic systems for the period of 1945-2017. We applied a bibliometric analysis method by coupling cluster analysis and network analysis. Results indicated that early research on antibiotics in water was mostly performed in America and Europe, while, in recent years, publications for the same subject were dominated by China and the USA. The majority of the articles were published in journal Chemosphere and the most representative subject categories of the seven sections were "Environmental science and ecology," "Chemistry," "Engineering," "Biochemistry and molecular biology," "Water resources," "Agriculture," and "Pharmacology and pharmacy." The most studied class of antibiotics was tetracyclines in wastewater. Antibiotic resistance, ARGs, Escherichia coli, and some mechanistic studies such as adsorption, toxicity, degradation, and kinetics were common topics in this field. ARGs present a major public health concern and much attention should be directed at the problems with antibiotics in the future studies of water.

A bibliometric review of nitrogen research in eutrophic lakes and reservoirs

The global application of nitrogen is far greater than phosphorus, and it is widely involved in the eutrophication of lakes and reservoirs. We used a bibliometric method to quantitatively and qualitatively evaluate nitrogen research in eutrophic lakes and reservoirs to reveal research developments, current research hotspots, and emerging trends in this area. A total of 2695 articles in the past 25years from the online database of the Scientific Citation Index Expended (SCI-Expanded) were analyzed. Articles in this area increased exponentially from 1991 to 2015. Although the USA was the most productive country over the past 25years, China achieved the top position in terms of yearly publications after 2010. The most active keywords related to nitrogen in the past 25years included phosphorus, nutrients, sediment, chlorophyll-a, carbon, phytoplankton, cyanobacteria, water quality, modeling, and stable isotopes, based on analysis within 5-year intervals from 1991 to 2015 as well as the entire past 25years. In addition, researchers have drawn increasing attention to denitrification, climate change, and internal loading. Future trends in this area should focus on: (1) nutrient amounts, ratios, and major nitrogen sources leading to eutrophication; (2) nitrogen transformation and the bioavailability of different nitrogen forms; (3) nitrogen budget, mass balance model, control, and management; (4) ecosystem responses to nitrogen enrichment and reduction, as well as the relationships between these responses; and (5) interactions between nitrogen and other stressors (e.g., light intensity, carbon, phosphorus, toxic contaminants, climate change, and hydrological variations) in terms of eutrophication.

Environmental risk assessment of cobalt and manganese from industrial sources in an estuarine system

A total of 74 samples of soil, sediment, industrial sludge, and surface water were collected in a Mediterranean estuarine system in order to assess the potential ecological impact of elevated concentrations of Co and Mn associated with a Terephthalic (PTA) and Isophthalic (PIPA) acids production plant. Samples were analyzed for elemental composition (37 elements), pH, redox potential, organic carbon, and CaCO₃ content, and a group of 16 selected samples were additionally subjected to a Tessier sequential extraction. Co and Mn soil concentrations were significantly higher inside the industrial facility and around its perimeter than in background samples, and maximum dissolved Co and Mn concentrations were found in a creek near the plant's discharge point, reaching values 17,700 and 156 times higher than their respective background concentrations. The ecological risk was evaluated as a function of Co and Mn fractionation and bioavailability which were controlled by the environmental conditions generated by the advance of seawater into the estuarine system during high tide. Co appeared to precipitate near the river mouth due to the pH increase produced by the influence of seawater intrusion, reaching hazardous concentrations in sediments. In terms of their bioavailability and the corresponding risk assessment code, both Co and Mn present sediment concentrations that result in medium to high ecological risk whereas water concentrations of both elements reach values that more than double their corresponding Secondary Acute Values.

Benchmarking the scientific research on wastewater-energy nexus by using bibliometric analysis

With an exponential increase in urbanization and industrialization, water pollution is an inevitable consequence of relatively lagging wastewater treatment facilities. The conventional activated sludge process for wastewater treatment primarily emphasizes the removal of harmful substances to maintain increasingly stringent effluent discharged standards, which is considered an energy-intensive technique. Therefore, innovative and sustainable wastewater treatment should pay more attention to energy and resource recovery in dealing with fossil fuel depletion, global-scale energy security, and climate change. A bibliometric analysis was applied to trace wastewater-energy nexus-related research during the period 1991 to 2015, with respect to the Science Citation Index EXPANDED (SCI-EXPANDED) database. Journal of Hazardous Materials, ranking 1st in h-index (79), was the most productive journal (431, 4.5%) during the same time, followed by International Journal of Hydrogen Energy (422, 4.4%) and Water Research (393, 4.1%) journal, the latter owning a topmost journal impact factor. Though, China (2154, 22.5%) was the most productive country, while the USA with highest h-index (88) was the favorest collaborative country. The Chinese Academy of Sciences, China (241, 2.5%) produced the maximum publications. A novel method called "word cluster analysis" showed that the emerging sustainable processes and novel renewable energy application are applied in response to the desire for a net wastewater-energy nexus system. Based on different wastewater types, the emerging energy and sources recovery treatment processes of Anammox, anaerobic digestion, and microbial fuel cells gained extensive innovation. Evaluation indicators including sustainability, life cycle assessment, and environmental impact were appropriately used to dissert feasibility of the novel treatment methods in regard of renewable energy utilization, energy savings, and energy recovery. The transformation of the new concept of "broaden income source, economize on expenditures and exploit inner potential" should be generalized in order to achieve an environmentally sustainable development of wastewater-energy nexus system.

Temporal patterns of induction and recovery of biomarker transcriptional responses to 4-Nonylphenol and 17β-estradiol in the estuarine arrow goby, Clevelandia ios

Several estuaries along the Pacific Ocean coast of North America were identified recently as having elevated 4-nonylphenol (4-NP) in sediments and biota, raising concerns about reproductive impacts for wildlife given 4-NP's established estrogenic activity as an endocrine-disrupting compound. Here we characterize 4-NP mediated induction and recovery of estrogen-sensitive gene transcripts in the arrow goby (Clevelandia ios), an intertidal fish abundant in estuarine mud flats on the west coast of North America. Male gobies were exposed to waterborne 4-NP at 10 μg/L or 100 μg/L for 20 days followed by a 20 day depuration period. Additional males were treated with 17β-estradiol (E2; 50 ng/L). 4-NP at 100 μg/L elevated hepatic mRNAs encoding vitellogenins A (vtgA) and C (vtgC) and choriogenin L (chgL) within 72 h, and choriogenin H minor (chgHm) within 12 days. Hepatic mRNAs encoding estrogen receptor alpha (esr1) were also elevated after 12 days of 4-NP exposure, but returned to pre-exposure levels at 20 days even under continuing 4-NP treatment. 4-NP did not alter mRNA levels of estrogen receptor gamma (esr2a) in the liver, or of esr1, esr2a, and cytochrome P450 aromatase B (cyp19a1b) in the brain. The temporal pattern of initial induction for hepatic vtgA, vtgC, and chgL transcripts by 4-NP mirrored the pattern by E2, while chgHm and esr1 mRNA induction by 4-NP lagged 2-11 days behind the responses of these transcripts to E2. These findings establish 4-NP concentration- and time-dependent induction patterns of choriogenin and vitellogenin transcription following exposure to environmentally relevant 4-NP concentrations, while concurrently demonstrating tissue-specific induction patterns for esr1 by estrogenic compounds. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 1513-1529, 2017.

Response of microbial communities colonizing salt marsh plants rhizosphere to copper oxide nanoparticles contamination and its implications for phytoremediation processes

This study aimed to investigate Cu oxide nanoparticles (CuO NP) effect on microbial communities associated with salt marsh plants (Halimione portulacoides and Pragmites australis) rhizosphere and its implications for phytoremediation processes. Experiments were conducted, under controlled conditions, over one week. Rhizosediment soaked in the respective elutriate (a simplified natural medium) with or without plants, was doped with CuO NP or with Cu in ionic form. Microbial community in rhizosediments was characterized in terms of abundance (by DAPI) and structure (by ARISA). Metal uptake by plants was evaluated by measuring Cu in plant tissues (by atomic absorption spectroscopy). Results revealed significant metal uptake but only in plant roots, which was significantly lower (H. portulacoides) or not significant (P. australis) when the metal was in NP form. Microbial community structure was significantly changed by the treatment (absence/presence of Cu, ionic Cu or CuO NP) as showed by multivariate analysis of ARISA profiles and confirmed by analysis of similarities (Global test - one way ANOSIM). Moreover, in P. australis rhizosediments microbial abundance, bacterial richness and diversity indexes were significantly affected (increased or decreased) due to metal presence whereas in H. portulacoides rhizosediment microbial abundance showed a significant decrease, particularly when the metal was in NP form. Accordingly, Cu presence affected the response of the rhizosphere microbial community and in some cases that response was significantly different when Cu was in NP form. The response of the microbial communities to Cu NP might also contribute to the lower metal accumulation by plants when the metal was in this form. So, Cu NP may cause disturbances in ecosystems functions, ultimately affecting phytoremediation processes. These facts should be considered regarding the use of appropriate salt marshes plants to remediate moderately impacted areas such as estuaries, where NPs can be found.

Effect of 4-nonylphenol on the immune response of the Pacific oyster Crassostrea gigas following bacterial infection with Vibrio campbellii

The xenoestrogen 4-nonylphenol (NP) is a ubiquitous aquatic pollutant and has been shown to impair reproduction, development, growth and, more recently, immune function in marine invertebrates. We investigated the effects of short-term (7 d) exposure to low (2 μg l^-1) and high (100 μg l^-1) levels of NP on cellular and humoral elements of the innate immune response of Crassostrea gigas to a bacterial challenge. To this end, we measured 1) total hemocyte counts (THC), 2) relative transcript abundance of ten immune-related genes (defh1, defh2, bigdef1, bigdef2, bpi, lysozyme-1, galectin, C-type lectin 2, timp, and transglutaminase) in the hemocytes, gill and mantle, and 3) hemolymph plasma lysozyme activity, following experimental Vibrio campbellii infection. Both low and high levels of NP were found to repress a bacteria-induced increase in THC observed in the control oysters. While several genes were differentially expressed following bacterial introduction (bigdef2, bpi, lysozyme-1, timp, transglutaminase), only two genes (bpi in the hemocytes, transglutaminase in the mantle) exhibited a different bacteria-induced expression profile following NP exposure, relative to the control oysters. Independently of infection-status, exposure to NP also altered mRNA transcript abundance of several genes (bpi, galectin, C-type lectin 2) in naïve, saline-injected oysters. Finally, plasma lysozyme activity levels were significantly higher in low dose NP-treated oysters (both naïve and bacteria challenged) relative to control oysters. Combined, these results suggest that exposure to ecologically-relevant (low) and extreme (high) levels of NP can alter both cellular and humoral elements of the innate immune response in C. gigas, an aquaculture species of global economic importance.

Guiana Dolphins (Sotalia guianensis) and DR-CALUX for Screening Coastal Brazilian Environments for Dioxins and Related Compounds

Guiana dolphin is the top predator of highest toxicological concern in Brazil and many studies on levels of persistent, bioaccumulative, and toxicant (PBT) pollutants have been performed on the species. However, due to high costs of the analyses, only one investigation comprised the determination of dioxins and related compounds (DRCs) in Guiana dolphin tissues. The dioxin responsive-chemically activated luciferase gene expression (DR-CALUX(®)) cell bioassay was used in the present study for the analyses of hepatic samples from 28 male Guiana dolphins in order to screen estuarine environments for DRCs, comprising three regions (Northeastern, Southeastern, and Southern) and four states [Paraná (PR), Rio de Janeiro (RJ), Espírito Santo (ES), and Ceará (CE)] of Brazil. High bioanalytical equivalent (BEQ) concentrations [dioxins (pg BEQ/g lipid)] were found, varying from 1.94 to 15.6 pg BEQ/g. A significant negative correlation between BEQ concentrations and total length was found in Guiana dolphins from Brazil (all analysed dolphins). This pattern also was verified for RJ state, pointing to (1) chemically induced developmental disruption or to (2) increasing efficiency of the detoxifying activity with the growth of the animal. Comparison was performed with literature data and significantly higher BEQ levels were found in Brazilian Guiana dolphins than in those reported for North Sea harbour porpoises. Higher levels were found in Southeastern (the most PBT-contaminated area of the country) than in Southern region. However, it is not possible to affirm that Guiana dolphins are more contaminated by DRCs in SE than in S region, because individuals were lengthier in S than in SE region. Our results seem to have mirrored dolphin exposure to PCBs in Brazil according to the literature. Further studies are required for investigating the hypotheses 1 and 2 mentioned above.

Spatial assessment and source identification of heavy metals pollution in surface water using several chemometric techniques

This study presents the determination of the spatial variation and source identification of heavy metal pollution in surface water along the Straits of Malacca using several chemometric techniques. Clustering and discrimination of heavy metal compounds in surface water into two groups (northern and southern regions) are observed according to level of concentrations via the application of chemometric techniques. Principal component analysis (PCA) demonstrates that Cu and Cr dominate the source apportionment in northern region with a total variance of 57.62% and is identified with mining and shipping activities. These are the major contamination contributors in the Straits. Land-based pollution originating from vehicular emission with a total variance of 59.43% is attributed to the high level of Pb concentration in the southern region. The results revealed that one state representing each cluster (northern and southern regions) is significant as the main location for investigating heavy metal concentration in the Straits of Malacca which would save monitoring cost and time.

CAPSULE

The monitoring of spatial variation and source of heavy metals pollution at the northern and southern regions of the Straits of Malacca, Malaysia, using chemometric analysis.

Metal bioaccumulation and physiological condition of the Pacific oyster (Crassostrea gigas) reared in two shellfish basins and a marina in Normandy (northwest France)

A 5-month experiment combining a geochemical survey of metals with a bioaccumulation study in batches of Crassostrea gigas was conducted in two shellfish farming areas and a marina in Normandy (France). Various endpoints at different levels of biological organization were studied. ROCCH data showed differences in biota contamination between the two shellfish areas but the present study revealed only slight differences in metallic contamination and biomarkers. By contrast, significantly different values were recorded in the marina in comparison with the two other sites. Indeed, higher levels of Cd, Cu and Zn were measured in the oysters from the marina, and these oysters also showed a poorer physiological condition (e.g., condition index, histopathological alterations and neutral lipid content). For coastal monitoring, the multi-biomarker approach coupled with an assessment of metallic contamination in biota appeared to be suitable for discriminating spatial differences in environmental quality after only a few months of exposure.

Response of a salt marsh microbial community to antibiotic contamination

Salt marsh plants and associated microorganisms can have an important role in contaminant removal from estuaries, through bioremediation processes. Nevertheless, the interaction between emerging contaminants, namely antibiotics, and plant-microorganism associations in estuarine environment are still scarcely known. In this vein, the aim of the present study was to evaluate, in controlled conditions, the response of a salt marsh plant-microorganism association to a contamination with a veterinary antibiotic. For that a salt marsh plant (Phragmites australis) and its respective rhizosediment were collected in a temperate estuary (Lima estuary, NW Portugal) and exposed for 7 days to enrofloxacin (ENR) under different nutritional conditions in sediment elutriates. Response was evaluated in terms of ENR removal and changes in microbial community structure (evaluated by ARISA) and abundance (estimated by DAPI). In general, no significant changes were observed in microbial abundance. Changes in bacterial richness and diversity were observed but only in unplanted systems. However, multivariate analysis of ARISA profiles showed significant effect of both the presence of plant and type of treatment on the microbial community structure, with significant differences among all treatment groups. In addition, plants and associated microorganisms presented a potential for antibiotic removal that, although highly dependent on their nutritional status, can be a valuable asset to recover impacted areas such as estuarine ones.

Global Performance and Trend of QSAR/QSPR Research: A Bibliometric Analysis

A bibliometric analysis based on the Science Citation Index Expanded was conducted to provide insights into the publication performance and research trend of quantitative structure-activity relationship (QSAR) and quantitative structure-property relationship (QSPR) from 1993 to 2012. The results show that the number of articles per year quadrupled from 1993 to 2006 and plateaued since 2007. Journal of Chemical Information and Modeling was the most prolific journal. The internal methodological innovations in acquiring molecular descriptors and modeling stimulated the articles' increase in the research fields of drug design and synthesis, and chemoinformatics; while the external regulatory demands on model validation and reliability fueled the increase in environmental sciences. "Prediction endpoints", "statistical algorithms", and "molecular descriptors" were identified as three research hotspots. The articles from developed countries were larger in number and more influential in citation, whereas those from developing countries were higher in output growth rates.

Sexual dimorphism in Grp78 and Hsp90A heat shock protein expression in the estuarine copepod Eurytemora affinis

Aquatic organisms are constantly exposed to both natural and anthropogenic stressors. Under stress conditions, they elicit a cellular stress response, involving heat shock proteins (HSPs). HSPs are essential to protect proteins against aggregation and to help in the folding of native proteins or refolding of damaged ones. Because of their conservation among taxons and their inducibility after environmental/chemical stress, HSPs are commonly used as ecological and ecotoxicological biomarkers. However, the appropriate use of such molecular tools requires the investigation of the influence of biotic factors on their basal levels. As a first step in biomarker characterization, the present study aims to evaluate the impact of the reproductive cycle on the expression of the two major HSPs, Grp78 and Hsp90A in the estuarine copepod Eurytemora affinis. The constitutive expression of both genes in males was weak when compared to female levels suggesting gender-specific stress tolerance. Transcript levels gradually increased during oogenesis and maximal levels were recorded in ovigerous females. The present data support the view that the reproductive condition of individuals has to be considered as a confounding factor in stress evaluation by HSP quantification.