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Northern East Asia was inhabited by modern humans as early as 40 thousand years ago (ka), as demonstrated by the Tianyuan individual. Using genome-wide data obtained from 25 individuals dated to 33.6-3.4 ka from the Amur region, we show that Tianyuan-related ancestry was widespread in northern East Asia before the Last Glacial Maximum (LGM). At the close of the LGM stadial, the earliest northern East Asian appeared in the Amur region, and this population is basal to ancient northern East Asians. Human populations in the Amur region have maintained genetic continuity from 14 ka, and these early inhabitants represent the closest East Asian source known for Ancient Paleo-Siberians. We also observed that EDAR V370A was likely to have been elevated to high frequency after the LGM, suggesting the possible timing for its selection. This study provides a deep look into the population dynamics of northern East Asia.
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Dinâmica Populacional , DNA Antigo/análise , Ásia Oriental , Feminino , Variação Genética , Genética Populacional , Genoma Humano , Geografia , Humanos , Camada de Gelo , Funções Verossimilhança , Masculino , Modelos Genéticos , Filogenia , Análise de Componente Principal , Fatores de TempoRESUMO
Many cases of an unknown disease exhibiting the clinical features of limb gangrene, blisters, ulceration, and exfoliation have been reported in Daping village (DV) in southwestern China. However, the pathogenesis is unknown and has puzzled doctors for many years. A preliminary study on heavy metals and symptoms indicated that arsenic might pose the greatest threat to the health of local residents. Here, to explore the sources of and factors influencing arsenic enrichment in DV, whose residents exhibit signs of arsenic poisoning, the As contents in soil, water, and plants were systematically measured. The results indicated high As contents in plant and soil samples obtained from the area, and the source of As may be linked to the weathering of black shale rock. Ingestion of soil and consumption of plants were the two main As exposure pathways among children and adults, respectively, and children exhibited a higher health risk than adults. We presume and emphasize that when extreme drought events occur, humans might face unusual risks resulting from exposure to toxic elements and the direct consumption of highly polluted water. Our study provides a new perspective and sheds light on the environmental geochemistry and health links of this disease.
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Arsênio , Metais Pesados , Poluentes do Solo , Criança , Adulto , Humanos , Arsênio/toxicidade , Arsênio/análise , Doenças Endêmicas , Monitoramento Ambiental/métodos , Poluentes do Solo/análise , Metais Pesados/análise , Solo/química , Plantas , Água , China/epidemiologia , Medição de RiscoRESUMO
In the present work, hematite-boron-carbonitride (Fe2O3-BCN) nanosheets were synthesized by a simple hydrothermal reaction and the following high temperature treatment. The morphology, structure and chemical composition of the as-prepared material were carefully characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The Fe2O3-BCN nanosheets were used to modified on the surface of the glassy carbon electrode to fabricate an electrochemical sensor for lead ions (Pb(II)) via differential pulse anodic stripping voltammetry (DPASV). At the same time, the influence of the modification concentration, solution acidity, deposition potential and deposition time on response peak current of Pb(II) at the Fe2O3-BCN-based electrochemical sensor was well investigated. Under the optimized conditions, the electrochemical signal and concentration of Pb(II) show two-stage linear relationship in the range of 0.5 - 40 µg/L and 40 -140 µg/L, with a limit of detection (LOD) of 0.129 µg/L. The Fe2O3-BCN-based electrochemical sensor shows excellent selectivity and anti-interference ability in the anti-interference experiments and actual sample analysis experiments, revealing its broad application in environmental monitoring of Pb(II).
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Nanopartículas , Água , Compostos Férricos , Íons , ChumboRESUMO
BACKGROUND: The heavy metal ion Cd2+ is acutely toxic, and excessive concentrations can have adverse effects on human production and life, and even lead to significant public health risks and environmental impacts. There are several mature non-electrochemical methods for heavy metal detection, but these methods are characterized by high cost, which makes it difficult to be applied to the field for timely detection. Therefore, it is necessary to prepare a new electrochemical sensor that is environmentally friendly and capable of detecting Cd2+ in the environment quickly, easily and sensitively. RESULTS: In this study, hydrogen-bonded organic frameworks (HOFs) were synthesized by a simple hydrothermal reaction. The prepared materials consisted of only C, N and O and had a thin lamellar structure. The HOFs were integrated into a novel electrochemical sensor to achieve accurate detection of Cd2+ ions in real aqueous environments by square wave anodic dissolution voltammetry. The sensor has a wide linear range and a detection limit as low as 0.13 µg/L. Several real water samples, such as tap water, lake water, and e-cigarette digest, were analyzed to simulate the working environment of the sensor, and the results showed that the recoveries of Cd2+ ranged from 95.75 % to 101.2 %. SIGNIFICANCE: We pioneered the detection of heavy metal ions Cd2+ in e-cigarette digestate samples with the innovative use of HOFs as the sensor material, which demonstrated the potential application in electrochemical sensing with extremely low background current value and high sensitivity, providing new ideas for environmental monitoring and public health control.
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Cádmio , Técnicas Eletroquímicas , Ligação de Hidrogênio , Cádmio/análise , Cádmio/química , Estruturas Metalorgânicas/química , Poluentes Químicos da Água/análise , Limite de Detecção , Íons/análise , Íons/químicaRESUMO
Understanding long-term dynamics is vitally important for explaining current biodiversity patterns and setting conservation goals in a changing world. However, the changes in biodiversity in time and space, particularly the dynamics at the centuries or even longer time scales, are poorly documented because of a lack of continuous monitoring data. The sedimentary DNA (sedDNA) has a great potential for paleo-community reconstruction, and it has recently been used as a powerful tool to characterize past dynamics in terms of biodiversity over geological timescales. In particular, it is useful for prokaryotes and eukaryotes that do not fossilize; hence, it is revolutionizing the scope of paleoecological research. Here, a "Research Weaving" method was performed with systematic maps and bibliometric webs based on the Web of Science for Science Citation Index Expanded, presenting a comprehensive landscape of the sedDNA that traces biological dynamics. We identified that most sedDNA-based studies have focused on microbial dynamics and on using samples from multitypes of sediments. This review summarized the advantages and common applications of sedDNA, focused on the biodiversity in microbial communities, and provided an outlook for the future of sedDNA research.
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Biodiversidade , Sedimentos Geológicos , DNA , Eucariotos/genética , EcossistemaRESUMO
A simple and efficient coagulation method was used for the rapid preparation of nitrogen-doped copper-cobalt oxide (N-Cu0.92Co2·08O4) supported on cerium dioxide (CeO2), that is, N-Cu0.92Co2·08O4@CeO2. A low concentration of N-Cu0.92Co2·08O4@CeO2 (0.15 g L-1) was shown to rapidly activate permonosulfate (PMS) (0.15 g L-1) to achieve 100% degradation of ranitidine within 10 min. A 100% degradation of ranitidine enabled by the catalyst was achieved over a wide range of pH (5.5-9.0), which could be completed within 8 min in the presence of anionic H2PO4-. Moreover, the N-Cu0.92Co2·08O4@CeO2 catalyst enabled more than 90% degradation of various typical antibiotics within 30 min, including tetracycline, sulfaixoxazole, and chloramphenicol, with degradation rates of 100%, 93.51%, and 90.01%, respectively. Even after four catalytic cycles, N-Cu0.92Co2·08O4@CeO2 could be regenerated to achieve 100% degradation of ranitidine. Electrochemical analysis demonstrated that the combination of N-Cu0.92Co2·08O4@CeO2 and PMS immediately produced a strong current density, thereby rapidly producing reactive oxygen species (ROS) with high performance for the degradation of the target pollutant. Combined ion quenching and electron paramagnetic resonance analyses indicated that the main ROS was the non-free radical 1O2. Finally, a plausible ranitidine degradation pathway was deduced based on liquid chromatography-mass spectrometry (LC-MS) analysis, wherein the toxic substance N-nitrosodimethylamine was not produced during the degradation process. In short, this study provides a new perspective for preparing ternary metal catalysts for advanced oxidation processes with practical application significance.
Assuntos
Cério , Nanopartículas , Espécies Reativas de Oxigênio , Ranitidina , Nitrogênio , Nanopartículas/química , Cério/química , Peróxidos/químicaRESUMO
Microbes serve as important components of ecosystem services and biogeochemical processes in plateau lakes. However, the features of microbiota assembly, abundance and diversity in plateau lakes remain unclear. The microbial communities in surface water from nine plateau lakes in Yunnan Plateau, southwestern China, in the dry and rainy seasons were explored using 16S rRNA gene and 18S rRNA gene sequencing. The results showed that the bacterial community compositions were homogeneous while those of micro-eukaryotes were heterogeneous in plateau lakes. In both seasons, the bacterial phyla of Proteobacteria and Actinobacteriota predominated in oligotrophic lakes. The mesotrophic lakes were dominated by Proteobacteria, Actinobacteriota, Bacteroidota and Cyanobacteria. The eutrophic lakes were mainly dominated by Proteobacteria, Actinobacteriota and Cyanobacteria. The phylum SAR_k_norank had the major micro-eukaryotes in these plateau lakes. The alpha-diversity of bacteria declined in the rainy season, while that of micro-eukaryotes varied from lake to lake. The drivers of microbiotic community assembly in the dry season were identified as nutrient level-related factors. In the rainy season, however, the microbiota in oligotrophic lakes were related to nutrient levels. Microbial communities were driven by precipitation in mesotrophic and eutrophic lakes with large water volumes, while those in lakes with small water volumes were regulated by nutrient level-related factors. Our findings pose first and unique insights into the microbiota of the nine plateau lakes in Yunnan Plateau, providing important ecological knowledge for these lakes with different characteristics.
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Cianobactérias , Microbiota , Lagos/química , China , RNA Ribossômico 16S/genética , Cianobactérias/genética , Proteobactérias/genética , ÁguaRESUMO
Peroxymonosulfate (PMS) driven by halloysite nanotubes (HNTs) modified with nanomanganese cobaltate (MnCo2O4) generates reactive oxygen species (ROS) that offer high degradation efficiency and mineralization rates for many typical antibiotic pollutants, such as ornidazole (ONZ). The experimental results show that halloysite nanotubes (HNTs) modified with nanomanganese cobaltate (MnCo2O4@HNTs denoted as MCO@HNTs) can degrade ONZ completely over a wide pH range (6.08-11.00) with little influence of the pH value. MCO@HNTs + PMS exhibited higher catalytic activity and lower Co- and Mn-ion leaching rates. It also showed a strong anti-interference effect on natural lake water and anions. Additionally, PMS can be quickly activated and consumed in natural lakes to avoid secondary pollution. The roasting of MCO@HNTs showed good catalytic activity and stability after degrading ONZ. The combination of ion quenching and electron paramagnetic resonance (EPR) analysis illustrated that the MCO@HNTs + PMS system had a strong oxidation capacity, and the produced singlet oxygen (1O2) was the main ROS for ONZ degradation. The degradation pathway of ONZ via the MCO@HNTs + PMS system was proposed based on the types of intermediates determined via liquid chromatography-mass spectrometry (LC-MS). This comprehensive study shows the preparation of a simple, environmentally friendly, and cheap PMS activation catalyst that has practical application value in the treatment of antibiotic wastewater and provides a focus on actual water testing with residual amount of PMS.
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Nanotubos , Ornidazol , Argila , Espécies Reativas de Oxigênio , Peróxidos/química , Antibacterianos , ÁguaRESUMO
Trace metal(loid) (TM) contamination, especially of aquatic ecosystems, is a global ongoing environmental problem. Fully and accurately determining their anthropogenic sources is a key requirement for formulating remediation and management strategies. Herein, we developed a multiple normalization procedure, combined with principal component analysis (PCA) to assess the influence of data-treatment and environmental factors on the traceability of TMs in surface sediments of Lake Xingyun, China. Multiple contamination indices, i.e., Enrichment factor (EF), Pollution Load Index (PLI), Pollution Contribution Rate (PCR) and Exceeded multiple discharge standard limits (BSTEL) suggest that contamination is dominated by Pb with the average EF exceed 3, especially within the estuary aeras with the PCR >40 %. The analysis demonstrates that the mathematical normalization of data, which adjusts it for various geochemical influences, has a significant effect on analysis outputs and interpretation. Routine (Log) and extreme (outlier removing) transformations may mask and skew important information contained within the original (raw) data, which create biased or meaningless principal components. Granulometric and geochemical normalization procedures can obviously identify the influence of grain size and other environmental impact on TM contents in principal components, but incorrectly explains the potential sources and contamination on different sites. Reducing the influence of organic matter by normalization allowed the mineralogy, bio-degradation, salinity, and anthropogenic sources associated with local sewage and anthropogenic smelting to be identified and interpreted more clearly. Moreover, the co-occurrence network analysis also confirms that the influence of grain size, salinity, and organic matter content are the primary factors controlling the spatial variability in the type and concentrations of TMs.
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The lability and controlling factors of arsenic (As) at the sediment-water interface (SWI) are crucial for understanding As behaviors and fates in As-contaminated areas. In this study, we combined high-resolution (5 mm) sampling using diffusive gradients in thin films (DGT) and equilibrium dialysis sampling (HR-Peeper), sequential extraction (BCR), fluorescence signatures, and fluorescence excitation-emission matrices (EEMs)-parallel factor analysis (PARAFAC) to explore the complex mechanisms of As migration in a typical artificially polluted lake, Lake Yangzong (YZ). The study results showed that a high proportion of the reactive As fractions in sediments can resupply pore water in soluble forms during the change from the dry season (winter, oxidizing period) to the rainy season (summer, reductive period). In dry season, the copresence of Fe oxide-As and organic matter (OM)-As complexes was related to the high dissolved As concentration in pore water and limited exchange between the pore water and overlying water. In the rainy season, with the change in redox conditions, the reduction of Fe-Mn oxides and OM degradation by microorganisms resulted in As deposition and exchange with the overlying water. Partial least squares path modelling (PLS-PM) indicated that OM affected the redox and As migration processes through degradation. Based on comprehensive analyses of the As, Fe, Mn, S and OM levels at the SWI, we suggest that the complexation and desorption of dissolved organic matter and Fe oxides play an important role in As cycling. Our findings shed new light on the cascading drivers of As migration and OM features in seasonal lakes and constitute a valuable reference for scenarios with similar conditions.
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This study investigated the influence of nitrate/nitrite on the degradation and transformation pathway of triclosan (TCS) in UV, UV/peracetic acid (PAA) and UV/HClO processes. The results indicated that the function of nitrate/nitrite significantly depended on the UV source and wavelength, especially nitrate. Generally, the presence of nitrate decreased the direct photo-degradation of TCS in the UV based disinfection. In the LED-UV and LED-UV/HClO processes, the presence of nitrate improved the radical oxidation, and transformation pathway of TCS was varied accordingly. However, nitrate more played a role of photo-competitor in the UV/PAA process, and the reactive nitrogen species (RNS) was difficult to participant in the degradation of TCS due to low redox potential. Compared to nitrate, the presence of nitrite decreased the degradation of TCS in three different UV based disinfection processes. Under UV irradiation, nitrite primarily acted as an irradiation competitor and radical scavenger. Thus, the indirect photo-degradation of TCS was reduced. Noticeably, nitrate/nitrite were the improtant precersors of nitrogenous products in the UV base disinfection. Many new nitrogenous products were identified. But RNS preferentially reacted with the intermediates by -NO2 addition compared to directly reacted with TCS.
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Triclosan , Poluentes Químicos da Água , Purificação da Água , Desinfecção , Humanos , Nitratos , Nitritos , Nitrogênio , Oxirredução , Ácido Peracético , Raios Ultravioleta , Purificação da Água/métodosRESUMO
This research focuses on the health risks caused by heavy metal (HM) environmental pollution. Soil, water, corn, rice, and patients' hair samples from Daping Village, Yunnan Province, China, were analyzed for seven selected HMs. Geoaccumulation index (Igeo), pollution indexes (PI), and the Nemerow integrated pollution index (PN) were used to evaluate pollution levels. We employed principal component analysis (PCA), correlation analysis (CA), and spatial distribution to identify the source and distribution characteristics of HMs in soil. Health risks of HMs and exposure pathways were accessed by calculating the hazard quotient (HQ) and hazard index (HI). The Igeo, PI, and PN results show that cadmium (Cd) and arsenic (As) pollution is severe in soil, while other pollution is relatively little. PCA, CA, and spatial distribution show that HMs may be derived from black shale weathering and enrichment. Residents' drinking water is relatively safe. Arsenic is the element most threatening to local residents (HI = 3.8). Soil (HI = 3.55) ingestion and plant (HI = 1.67) ingestion are the primary exposure pathways to HMs. This unusual disease may be caused by children's relatively low immunity and long-term exposure to As. We must enhance the protection of children and encourage avoiding soil contact as much as possible. Our results highlight the importance of investigating HM pollution from geological sources and blocking potential exposure pathways.
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Metais Pesados , Poluentes do Solo , Criança , China , Doenças Endêmicas , Monitoramento Ambiental , Humanos , Metais Pesados/análise , Medição de Risco , Solo , Poluentes do Solo/análiseRESUMO
Water quality and safety are vital to the ecological environment, social development, and ecological susceptibility. The extensive use and continuous discharge of antibiotics have caused serious water pollution; antibiotics are widely found in freshwater, drinking water, and reservoirs; and this pollution has become a common phenomenon and challenge in global water ecosystems, as water polluted by antibiotics poses serious risks to human health and the ecological environment. Therefore, the antibiotic content in water should be identified, monitored, and eliminated. Nevertheless, there is no single method that can detect all different types of antibiotics, so various techniques are often combined to produce reliable results. This review summarizes the sources of antibiotic pollution in water, covering three main aspects: (1) wastewater discharges from domestic sewage, (2) medical wastewater, and (3) animal physiology and aquaculture. The existing analytical techniques, including extraction techniques, conventional detection methods, and biosensors, are reviewed. The electrochemical biosensors have become a research hotspot in recent years because of their rapid detection, high efficiency, and portability, and the use of nanoparticles contributes to these outstanding qualities. Additionally, the comprehensive quality evaluation of various detection methods, including the linear detection range, detection limit (LOD), and recovery rate, is discussed, and the future of this research field is also prospected.
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Toxic trace elements represent an ongoing environmental problem in aquatic ecosystems. However, a lack of quantitative analysis and accurate evaluation has led to unguided control and water management strategies. Lake Yangzong is the main freshwater resource for nearly one million people in Yunnan Province in southwestern China. It has been heavily contaminated in recent years by significant anthropogenic activities including an industrial phosphor-gypsum spill, sewage effluent, and chemical remediation processes. Herein, we combine eco-environmental indices with multiple statistical analyses to determine the ecological risk and degree of contamination of 11 toxic trace elements in the upper sediments of the lakebed. Local geochemical background concentrations were determined using robust regression models developed from sediment core data. Pollution indices (EF/PLI) indicate that severe As contamination was centralized in the southwestern part of the lake. Other toxic trace elements (e.g., Cd, Cu, Pb) are slightly to moderately enriched, and progressively decrease from the northwestern to the southeastern areas of the lake. A more accurate and sensitive index (PCR) was proposed herein, suggesting that contamination was dominated by As and Pb in different lake sections. The northern section of the lake and the southwestern bay exhibited higher contaminant levels than other regions of the lake. Bio-toxic indices (ERF/PERI) indicate that As and Cd pose a high ecological risk, whereas Cu and Pb pose a low risk to biota. Statistical analyses (PCA/PMF) demonstrate that metal contaminants originated from three types of anthropogenic sources: the smelting of metal ores, the leakage of tailings effluent, and coal consumption.
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Sedimentos Geológicos , Lagos , Oligoelementos , Poluentes Químicos da Água , Arsênio/análise , Arsênio/toxicidade , Cádmio/análise , Cádmio/toxicidade , China , Cobre/análise , Cobre/toxicidade , Ecossistema , Sedimentos Geológicos/química , Humanos , Lagos/química , Chumbo/análise , Chumbo/toxicidade , Medição de Risco , Oligoelementos/análise , Oligoelementos/toxicidade , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidadeRESUMO
Persulfate-based advanced oxidation processes (AOPs) cannot easily achieve the efficient degradation of persistent organic pollutants (POPs) with high stability. In this study, a simple in situ precipitation method was used to prepare an amorphous Co@TiO2 heterojunction catalyst. The deposition of Co oxide on TiO2, which is relatively nontoxic, efficiently activated peroxymonosulfate (PMS) to degrade sulfamethazine (SMT) and reduce the leaching of Co ions (0.915%). A catalytic system prepared using 0.3 g L-1 Co@TiO2 and 0.5 g L-1 PMS could degrade SMT within 30 min with a degradation rate of 95.8%. Co@TiO2 could activate PMS over a wide pH range (5.00-9.00) to efficiently degrade other antibiotics and dyes. Radical-capture experiments and electron paramagnetic resonance analysis suggested that SMT degradation occurs through a combination of the free radical and non-radical pathways, in which singlet 1O2 played a major role. Owing to the novelty of the proposed composite materials, the degradation path of SMT, which was determined through liquid chromatography-mass spectrometry, differed from that reported previously. This study provides not only an advanced and renewable catalyst for SMT degradation but also a feasible strategy for designing materials for AOPs.
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Poluentes Orgânicos Persistentes , Sulfametazina , Antibacterianos/química , Corantes , Peróxidos/química , Sulfametazina/química , TitânioRESUMO
Trapa japonica was observed to have inhibiting effects and could be used as a potential environment-friendly control strategy for cyanobacterial blooms in freshwater. However, the changes and effecting mechanisms in eukaryotic and prokaryotic communities by T. japonica are not yet clear. In this study, the effects of T. japonica on microbial communities were assessed in Lake Qionghai and Lake Erhai by 18S rRNA and 16S rRNA amplicon sequencing, respectively. The results showed that T. japonica can improve biodiversity and change the microbial community structures to varying degrees in both lakes. The alpha diversity indexes of microbial communities (e.g., Shannon, Sobs, Ace and Chao 1) were higher in the water inhabited by T. japonica (TJ group) than the water uninhabited by T. japonica (control) (P < 0.05). The PCoA results suggested that the microbial community compositions differed between the two groups (PERMANOVA P = 0.001). In Lake Qionghai, the relative abundances of dominant taxa and nutrients level showed little differences between the two groups. These may result from the homogenous water condition in Lake Qionghai. While the genera Cyanobium_PCC-6307, the majority of Cyanobacteria, decreased significantly in TJ group than control according to 16S rRNA gene sequencing. In Lake Erhai, environmental variables were distinctly affected by T. japonica, which was found to drive Cryptophyceae to become the main taxa through taxonomic analysis of 18S rRNA. Based on 16S rRNA gene sequencing, T. japonica reduced the relative abundance of Cyanobacteria, such as Planktothrix_NIVA-CYA_15 and Cyanobium_PCC-6307, by enriching cyanobactericidal bacteria and growth-inhibiting bacteria (e.g., Limnohabitans and Flavobacterium) and changing environmental parameters. Our results revealed that T. japonica acts in shaping microbial communities in lakes on the community level, shedding new lights on eutrophication mitigation, one of the most serious global ecological problems we are facing.
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Cianobactérias , Microbiota , Cianobactérias/genética , Eutrofização , Lagos , RNA Ribossômico 16S/genéticaRESUMO
Considering the complexity of traditional cobalt phosphide (Co2P) loaded biochar synthesis research on a simple and efficient synthesis method has practical significance. In this study, after phosphoric acid activation, Neosinocalamus affinis biochar (NAB) and nanoplate Co3O4 quickly formed a Co2P-NAB composite material with high Co2P crystallinity and was uniformly dispersed on the surface of NAB in a microwave reactor. Co2P-NAB has an excellent catalytic degradation effect in the activation of peroxymonosulfate (PMS) to degrade tetracycline (TC). The optimal TC degradation efficiency was achieved with the addition of 50 mg L-1 TC concentration, 0.2 g L-1 catalysts, 0.406 mM PMS and pH = 6.02. In addition, according to the pseudo-first-order reaction rate constant calculation, the composite of Co2P-NAB and PMS the synergy efficiency is 81.55 %. Compared with Co2P-NAB (10.83 %) and PMS (7.62 %) alone, the Co2P-NAB/PMS system has a significant promotion effect on the degradation of TC molecules. Additionally, the Co2P-NAB/PMS system had a TC mineralization rate of 68 % in 30 min. Furthermore, after a series of characterization, detection and analysis, and influencing factor experiments, we proposed a potential mechanism for the Co2P-NAB/PMS reaction system to degrade TC and found that singlet oxygen (1O2) plays an essential role in the non-radical degradation process. Finally, according to the liquid chromatography-mass spectrometry (LC-MS) detection of TC degradation intermediates, a possible degradation route was proposed. Therefore, this work uses microwave technology to present a novel and simple synthesis method for transition metal phosphides, which provides potential application value for the treatment of actual wastewater with heterogeneous catalysts.
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Antibacterianos , Tetraciclina , Carvão Vegetal , Concentração de Íons de Hidrogênio , PeróxidosRESUMO
Graphene photocatalysis is a new method for harmful algae and water pollution control. However, microbial communities undergoing graphene photocatalysis treatment in freshwater lakes have been poorly studied. Here, using 16S rRNA and 18S rRNA gene high-throughput sequencing, the responses of microbial communities to graphene photocatalysis were analyzed in the eutrophic lake, Lake Xinyun, southwestern China. For microeukaryotes, we found that Arthropoda was dominant in summer, while its abundant level declined in spring under natural conditions. The evident reduction of Arthropods was observed after graphene photocatalysis treatment in summer and then reached a relatively stable level. For bacteria, Cyanobacteria decreased in summer due to the graphene photocatalysis-mediated inactivation. However, Cyanobacteria was higher in the treated group in spring with a genera group-shift. Functional analysis revealed that microeukaryotes showed higher potential for fatty acid oxidation and TCA cycle in the treated group in summer, but they were more abundant in control in spring. Pathways of starch and sucrose metabolism and galactose metabolism were more abundant in control in summer, while they were enriched in the treated group in spring for bacteria. This study offers insights into the effects of graphene photocatalysis on microbial communities and their functional potential in eutrophic lake.
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Cianobactérias , Grafite , Microbiota , China , Cianobactérias/genética , Sedimentos Geológicos/microbiologia , Lagos/microbiologia , RNA Ribossômico 16S/genéticaRESUMO
Steppe bison are a typical representative of the Mid-Late Pleistocene steppes of the northern hemisphere. Despite the abundance of fossil remains, many questions related to their genetic diversity, population structure and dispersal route are still elusive. Here, we present both near-complete and partial mitochondrial genomes, as well as a partial nuclear genome from fossil bison samples excavated from Late Pleistocene strata in northeastern China. Maximum-likelihood and Bayesian trees both suggest the bison clade are divided into three maternal haplogroups (A, B and C), and Chinese individuals fall in two of them. Bayesian analysis shows that the split between haplogroup C and the ancestor of haplogroups A and B dates at 326 ky BP (95% HPD: 397-264 ky BP). In addition, our nuclear phylogenomic tree also supports a basal position for the individual carrying haplogroup C. Admixture analyses suggest that CADG467 (haplogroup C) has a similar genetic structure to steppe bison from Siberia (haplogroup B). Our new findings indicate that the genetic diversity of Pleistocene bison was probably even higher than previously thought and that northeastern Chinese populations of several mammalian species, including Pleistocene bison, were genetically distinct.
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Bison , Genoma Mitocondrial , Animais , Bison/genética , Teorema de Bayes , Genoma Mitocondrial/genética , Fósseis , Evolução BiológicaRESUMO
The stable physicochemical properties of polyaniline/closo-[B12H12]2- (PA/B12) obtained by an ion exchange technique combined with polyaniline (PA) and closo-[B12H12]2- (B12) can realize rapid kinetic adsorption and complete removal of Cr(vi) and cationic dye pollutants at low concentrations. The reversible adsorption/desorption process of pollutants represents that PA/B12 has practical industrial use value.