Comparative growth inhibition of 6PPD and 6PPD-Q on microalgae Selenastrum capricornutum, with insights into 6PPD-induced phototoxicity and oxidative stress.

Widespread environmental detection of tire additive N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (6PPD) and its toxic metabolite 6PPD-Q has raised great concerns for their potential impact on aquatic biota. This study investigated the effects of 6PPD and 6PPD-Q on the model green microalgae (Selenastrum capricornutum). Results showed that 6PPD at the concentrations of 1-5 mg·L stimulated S.

Metabolisms and multiple functions of laminaran in marine algae under global change: A critical review.

Laminaran is a major storage of carbohydrate in marine algae. Its high content and potential functions draw increasing attention. However, our understanding of its metabolisms and functions is still fragmented.

Spatiotemporal profile and ecological impacts of major and trace elements in surface sediments of marginal seas of the Arctic and Northern Pacific Oceans.

The status and ecological impacts of sedimentary elements of the marginal seas of Arctic and Northern Pacific Oceans was investigated during 2016 to 2018 by using inductively coupled plasma mass spectrometry. Industrial (0.006 mg kg-64.

Resolving the dynamics of chrysolaminarin regulation in a marine diatom: A physiological and transcriptomic study.

Diatom containing different active biological macromolecules are thought to be an excellent microbial cell factory. Phaeodactylum tricornutum, a model diatom, is a superb chassis organism accumulating chrysolaminarin with important bioactivities. However, the characteristic of chrysolaminarin accumulation and molecular mechanism of the fluctuated chrysolaminarin in diatom are still unknown.

Urbanization influenced the interactions between dissolved organic matter and bacterial communities in rivers.

Increased urbanization and anthropogenic activities can alter dissolved organic matter (DOM) and complicate its interaction with bacteria in rivers' ecosystems, however, there is limited information about how bacterial communities respond to DOM components in rivers with different urbanization levels. Here, we combined spectroscopy-based DOM analysis and 16S rRNA gene amplicon sequencing to investigate the associations of bacterial taxa and DOM properties as well as the impacts of DOM on bacterial niche breadth in North River (NR) and West River (WR) of Jiulong River watershed, southern China, which had low and high urbanization levels, respectively. Spectroscopy analysis showed that hydrophilic DOM was predominant in both rivers whereas chromophoric DOM was higher in WR.

Transmission mechanisms of antibiotic resistance genes in arsenic-contaminated soil under sulfamethoxazole stress.

Numerous studies have revealed the spread mechanism of antibiotic resistance genes (ARGs) in single antibiotic-contaminated soils. However, the comprehensive impacts of heavy metals and antibiotics on ARGs and the underlying mechanisms are still unknown. Here, high-throughput quantitative PCR and high-throughput sequencing were used to investigate changes in ARGs and bacterial communities under various sulfamethoxazole (SMX) regimes (0, 1, 10, 50 mg kg) in arsenic (As) contaminated soils.

Poultry manure gleaned antibiotic residues in soil environment: A perspective of spatial variability and influencing factors.

The antibiotics released by human and animals end up in the environmental sinks like soil and water to cause contamination and induce resistance in the microflora. The knowledge of fate and behavior of antibiotics in diverse geographical, climatological, and physicochemical is limited. Therefore, present study investigated the spatial distribution of antibiotics and their relationship with various factors and the source-sink relationship between soil and poultry manure.

Factors leading to the academic failure of undergraduate medical students - Predict early to prevent.

Objectives: The main objective of the study was to explore the factors to predict academic failure before the first major assessment.

Methods: An exploratory qualitative study was conducted from March 2021 to August 2021 at Riphah International University. Using the purposive sampling technique, 16 students and seven teachers were included in the study.

Insight into variation and controlling factors of dissolved organic matter between urban rivers undergoing different anthropogenic influences.

Dissolved organic matter (DOM), known as a key to the aquatic carbon cycle, is influenced by abiotic and biotic factors. However, the compositional variation and these factors' effects on fluorescence DOM (FDOM) in urban rivers undergoing different anthropogenic pressure are poorly investigated. Herein, using fluorescence excitation-emission matrix and parallel factor analysis (EEM-PARAFAC), four FDOM components (C1, C2, C3, and C4) were identified in a less urbanized north river (NR) and a more urbanized west river (WR) of Jiulong River Watershed in Fujian province, China.

Spatial autocorrelation and temporal variation of contaminants of emerging concern in a typical urbanizing river.

The distribution and fate of contaminants of emerging concern (CECs) was studied in relation to hydrological conditions, land use characteristics, and spatial contiguity in Houxi River. Thirty-four CECs were detected in the surface water during a three-year sampling campaign. Caffeine was most prevalent (99% frequency), while bisphenol A had the highest median concentration (78.

Microalgal mediated antibiotic co-metabolism: Kinetics, transformation products and pathways.

The mutual interaction of a microalga Chlorella vulgaris with four antibiotics viz. sulfamethoxazole (SMX), trimethoprim (TMP), azithromycin (AZI), and levofloxacin (LEV) individually and in mixture was studied in batch culture. SMX, TMP, and LEV stimulated algal growth, while AZI inhibited its growth.

Integrated assessment of major and trace elements in surface and core sediments from an urban lagoon, China: Potential ecological risks and influencing factors.

Marine sediments serve as a sink for contaminants of anthropogenic origin. Here, 25 major and trace elements were determined in surface and core sediments from an urban lagoon (Yundang Lagoon), China. The median concentrations of Pb, Cd, Cu, and Zn in both surface and core sediments exceeded global and crustal averages.

Volumetric Modulated Arc Therapy (VMAT): A modern radiotherapy technique - A single institutional experience.

Objective: To evaluate VMAT plans for conformity and homogeneity of radiation dose to the target in order to share our experience as a pioneering institute to use VMAT technology in Pakistan.

Methods: Since December 2014 to January 2018, 530 patients of various anatomical sites were treated by VMAT technique at Neurospinal Cancer Care Institute (NCCI) Karachi Pakistan. ERGO++ planning system (Version 1.

Horizontal and vertical gene transfer drive sediment antibiotic resistome in an urban lagoon system.

Rapid urbanization has resulted in pervasive occurrence of antibiotic resistance genes (ARGs) in urban aquatic ecosystems. However, limited information is available concerning the ARG profiles and the forces responsible for their assembly in urban landscape lagoon systems. Here, we employed high-throughput quantitative PCR (HT-qPCR) to characterize the spatial variations of ARGs in surface and core sediments of Yundang Lagoon, China.

Checklist of earthworm species (Oligochaeta) of the North Eastern Region of India.

A checklist of earthworm species hitherto recorded from North Eastern Region (NER) of India is presented. In total, 128 species/subspecies belonging to 26 genera spread over 9 families are listed. Of these, 72 species are recognized as endemics, 18 as near endemics, 5 as native peregrines and 32 as exotics.

Co-selection of antibiotic resistance genes, and mobile genetic elements in the presence of heavy metals in poultry farm environments.

Environmental selection of antibiotic resistance genes (ARGs) is considered to be caused by antibiotic or metal residues, frequently used in livestock. In this study we examined three commercial poultry farms to correlate the co-occurrence patterns of antibiotic and metal residues to the presence of ARGs. We quantified 283 ARGs, 12 mobile genetic elements (MGEs), 49 targeted antibiotics, 7 heavy metals and sequenced 16S rRNA genes.

Distinct mechanisms underlying the assembly of microeukaryotic generalists and specialists in an anthropogenically impacted river.

Microeukaryotic communities are sensitive to environmental changes; and are considered essential for microbial food webs and biogeochemical cycles. Therefore, understanding the community responses of microeukaryotes to environmental changes is of great ecological significance. Very little is known about the assembly mechanisms underlying the microeukaryotic communities, especially for the key ecological groups (e.

Homogeneous selection drives antibiotic resistome in two adjacent sub-watersheds, China.

Rivers are a significant reservoir of antibiotic resistance genes (ARGs), yet the biogeographic pattern of riverine ARGs and its underlying driving forces remain poorly understood. Here, we used metagenomic approach to investigate the spatio-temporal variation of ARGs in two adjacent sub-watersheds viz. North River (NR) and West River (WR), China.

Simultaneous analysis of multiclass antibiotic residues in complex environmental matrices by liquid chromatography with tandem quadrupole mass spectrometry.

A simultaneous extraction and cleanup method was optimized and validated for the determination of 40 antibiotics from cephalosporin, fluoroquinolone, lincosamide, macrolide, nitroimidazole, quinolone, sulfonamide and tetracycline groups in sediments by liquid chromatography with tandem quadrupole mass spectrometry (LC-MS/MS). The method involved hydration of freeze-dried sediment sample (2.0 g) with 2.

Strong impact of micropollutants on prokaryotic communities at the horizontal but not vertical scales in a subtropical reservoir, China.

Micropollutants have become of great concern, because of their disrupting effects on the structure and function of microbial communities. However, little is known about the relative importance of trace micropollutants on the aquatic prokaryotic communities as compared to the traditional physico-chemical characteristics, especially at different spatial dimensions. Here, we investigated free-living (FL) and particle-associated (PA) prokaryotic communities in a subtropical water reservoir, China, across seasons at horizontal (surface water) and vertical (depth-profile) scales by using 16S rRNA gene amplicon sequencing.

Dissipation of antibiotics by microalgae: Kinetics, identification of transformation products and pathways.

Dissipation potential of four algae viz. Haematococcus pluvialis, Selenastrum capricornutum, Scenedesmus quadricauda and Chlorella vulgaris was investigated against ten antibiotics (sulfamerazine, sulfamethoxazole, sulfamonomethoxine, trimethoprim, clarithromycin, azithromycin, roxithromycin, lomefloxacin, levofloxacin and flumequine) in a series of synthetic wastewater batch culture experiments, maintained at 20, 50 and 100 μg L initial concentration levels and incubated over a period of 40 days. Generally, the antibiotic removal was achieved with overall dissipation percentage (%) varying among the algal species and different antibiotics.

Response of prokaryotic communities to extreme precipitation events in an urban coastal lagoon: A case study of Yundang lagoon, China.

Increasing extreme precipitation events (EPEs) can induce biogeochemical disturbances in the coastal lagoon ecosystems. Very little is known about the response of prokaryotic communities to such influences, which are the key components mediating the biogeochemical cycling in lagoons. Here 16S rRNA gene amplicon sequencing and high-through quantitative PCR (HT-qPCR) were employed to investigate the distribution of prokaryotic communities and fecal indicator genes in the surface waters of Yundang lagoon, Xiamen, China during EPEs, respectively.

Immobilized cells of a novel bacterium increased the degradation of methylated carbamates under low temperature conditions.

Carbamates are synthetic pesticides, extensively used throughout the world due to their broad specificity against various insect pests. However, their enormous and inadequate use have made them a potential threat to the environment. At low temperature, degradation of carbamates becomes difficult mainly because of low biological activity.

Environmental Filtering Drives the Assembly of Habitat Generalists and Specialists in the Coastal Sand Microbial Communities of Southern China.

Coastal sands harbor diverse microbial assemblages that play a critical role in the biogeochemical cycling of beach ecosystems. However, little is known about the relative importance of the different ecological processes underlying the assembly of communities of sand microbiota. Here, we employed 16S rDNA amplicon sequencing to investigate the sand microbiota of two coastal beaches, in southern China.