Mercury (Hg) is a notorious toxic heavy metal, causing neurotoxicity and liver damage, posing grave threats to human health and environmental safety. There is an urgent imperative for developing novel Hg2+ detection methods. In this work, we developed a CRISPR-based method for Hg2+ detection named CRISPR-Hg. A CRISPR/ Cas12a system was employed and could be activated by the PCR product, generating fluorescence signals based on the trans-cleavage activity. CRISPR-Hg exhibited remarkable selectivity and specificity, achieving a detection limit of 10 pM and minimal interference with background signals. This approach has been successfully applied to detect Hg2+ in real samples, including water, soil, and mushroom. Ulteriorly, a portable device was devised to streamline the readout of fluorescence signals by a smartphone within 30 min. We offer an affordable, highly selective and visually interpretable method for Hg2+ detection, with the potential for broad application in Hg2+ monitoring for food safety and public health.
Perennial ornamental grasses are often recommended for rain gardens, but few data support their use. We conducted two experiments to evaluate the ability of ornamental grass cultivars to grow while subjected to cyclical fl ooding, submergence, and drought typical of rain gardens. Our objectives were to determine the effects of cyclical fl ood and drought (Expt. 1) and submergence depth and duration (Expt. 2) on grass growth and survival. Seven cultivars were evaluated during greenhouse trials, including Pixie Fountain tufted hairgrass [Deschampsia cespitosa (L.) P. Beauv.], Northwind switchgrass (Panicum virgatum L.), Red October big bluestem (Andropogon gerardii Vitman), Purpurascens Chinese silvergrass (Miscanthus sinensis Andersson), Blue HeavenVR V R little bluestem [Schizachyrium scoparium (Michx.) Nash], Blonde Ambition blue grama grass [Bouteloua gracilis (Kunth) Lag. ex Griffiths], fi ths], and Karl Foerster feather reed grass [Calamagrostis xacutiflora fl ora (Schrad.) DC]. During Expt. 1, grasses underwent four cycles of fl ooding duration (2 days or 7 days) followed by drought (drying to volumetric soil water contents of 0.14 or 0.07 cm3cm23). 3 cm 2 3 ). During Expt. 2, grasses were cyclically submerged at 15 or 30 cm above the soil surface for 2, 4, or 7 days, followed by fl oodwater removal and drainage for 2 days before being resubmerged. Cyclical submergence continued until the 7-day submergence treatments completed four cycles. Both experiments were replicated in a full factorial randomized complete block design. Controls were included in both experiments. Plants were measured to determine plant height, shoot count, visual damage rating, shoot dry weight, and root dry weight. Floodwater chemistry and soil reducing conditions were measured during Expt. 2. Chinese silvergrass and switchgrass survived cyclical soil fl ooding/drought and submergence for 7 days at a depth of 30 cm while maintaining acceptable foliar damage. All grasses survived cyclical fl ood and drought when the soil volumetric water content was maintained at 14%, suggesting they can withstand periodic soil fl ooding as long as the water is not too deep. As water depth and duration increased from 4 days to 7 days, little bluestem, blue grama grass, and feather reed grass experienced significant fi cant foliar damage. Tufted hair grass and big bluestem experienced signifi- fi- cant foliar damage when submerged for 2 days. Our results showed that perennial ornamental grasses can tolerate cyclical fl ood and drought and periodic submergence, but that plant conditions and survival vary, which can inform strategic plant placement within rain gardens, bioretention basins, and other stormwater management systems.
Animal logging is one of the most ancient wood extraction methods and it is still applied in different parts of the world, including industrialised countries. Animal logging is often imagined as a low-impact method and sometimes, or rather often, it is recommended as a best-management practice. However, the literature findings depict a more complex scenario, and the goal of the present review is to shed light on the topic of environmental sustainability of logging operations performed by animals. Usually, animal logging causes less pollutant emissions and less damage to the residual stand in comparison to ground-based mechanised extraction methods. However, when applied in commercial forestry interventions such as coppicing, animal logging showed levels of soil compaction in line with those of ground-based machinery like tractors, skidders and forwarders. Specifically developed trials revealed that in the animal skid trails a strong disturbance to the soil microarthropod community occurred. Furthermore, the soil features in the animal trails seemed to get worse over time after logging, thus suggesting the possible presence of strong localised erosion along these trails. Despite the strong need to further investigate this topic, concerning the ecological aspects of forest soil which were generally neglected by the literature, the use of animal logging can be recommended in the case of small-scale forestry with wooden material sparsely located throughout the logging site. In the case of commercial logging on steep slopes instead it is recommended to replace animal logging with cable-based extraction systems.
Hg2+ is one of the most toxic heavy metal ions, which can cause air, soil, and water pollution, seriously damaging human health. Therefore, developing effective analytical methods to detect Hg2+ in environmental systems is particularly important. Fluorescent probes have been widely used to detect Hg2+ due to their advantages, such as high sensitivity, good selectivity, fast response time, and real-time online detection. In this paper, a novel turn-on fluorescent probe (2-(pyren-1-yl)-1,3-oxathiolane, POX) with 1,3-oxathiolane as receptor was designed and synthesized based on Hg2+-promoted deprotection reaction of thioacetal, and H-1 NMR, C-13 NMR, and HRMS characterized its structure. The selectivity, competitiveness, concentration titration, pH titration, time dependence, the limit of detection, and recognition mechanism of POX for the detection of Hg2+ in CH3CH2OH/H2O solution were investigated. The results showed that POX could quickly recognize Hg2+ in a wide pH range and exhibited high selectivity and sensitivity. Adding Hg2+ to the solution of POX resulted in a clear fluorescence emission peak at 386 nm, indicating that POX showed a remarkable turn-on fluorescence for Hg2+, and its recognition process was almost unaffected by other metal ions. Fluorescence titration experiments indicated that POX had a good linear response (R-2=0.999 4) in the range of Hg2+ from 0 similar to 6.5 mu mol.L-1, with a detection limit of 0.168 mu mol.L-1. The RSD of POX for detecting Hg2+ in actual water samples was less than 2.92%. The simple synthesis, easy availability of raw materials, and wide pH applicability of POX suggested that it could be used as a potential tool for the qualitative and quantitative detection of Hg2+ in the environment.
Draining peatlands to create agricultural land has been the norm in Europe, but in the context of climate change and the loss of biodiversity, these rich ecosystems may reactivate their functions as greenhouse gas sinks and retreat spaces for animals and plants. Against this background, the National Moor Rewetting Strategy was put into effect in Germany in 2023, together with the Natural Climate Protection Action Plan. This article examines the methodology of peatland rewetting from scientific, administrative, social, and technical perspectives. The article focuses on an example of moor rewetting in central Germany: the Rathsbruch moor near the municipality of Zerbst, Saxony-Anhalt. To illustrate the importance of rewetting projects for degraded peatlands, five scenarios with different target soil water levels were considered, and the associated greenhouse gas emissions were calculated for a period of five years. For the planning solution, an estimate of the medium-to-long-term development of the habitat types was made based on current use and the dynamics typical of the habitat. The results for the Rathsbruch moor area showed that increasing the water level in steps of 1, 0.8, or 0.5 m has no significant influence on reducing the CO2 emissions situation, while a depth of 0.3 m has a slight influence. When the water was raised to 0.1 m below the surface (Scenario 5), a significant CO2 reduction was observed. The calculated avoided CO2 costs due to environmental damage show that the environmental benefits multiply with every decimeter of water level increase. The rising groundwater levels and extensification favor the establishment of local biotopes. This means that two of the biggest man-made problems (extinction of species and climate change) can be reduced. Therefore, this research is applicable to the development and planning of recultivation work at municipal and regional levels in Germany and beyond within the framework of EU restoration policy.
The intake of methylmercury (MeHg)-contaminated rice poses immense health risks to rice consumers. However, the mechanisms of MeHg accumulation in rice plants are not entirely understood. The knowledge that the MeHg-Cysteine complex was dominant in polished rice proposed a hypothesis of co-transportation of MeHg and cysteine inside rice plants. This study was therefore designed to explore the MeHg accumulation processes in rice plants by investigating biogeochemical associations between MeHg and amino acids. Rice plants and underlying soils were collected from different Hg-contaminated sites in the Wanshan Hg mining area. The concentrations of both MeHg and cysteine in polished rice were higher than those in other rice tissues. A significant positive correlation between MeHg and cysteine in rice plants was found, especially in polished rice, indicating a close geochemical association between cysteine and MeHg. The translocation factor (TF) of cysteine showed behavior similar to that of the TF of MeHg, demonstrating that these two chemical species might share a similar transportation mechanism in rice plants. The accumulation of MeHg in rice plants may vary due to differences in the molar ratios of MeHg to cysteine and the presence of specific amino acid transporters. Our results suggest that cysteine plays a vital role in MeHg accumulation and transportation inside rice plants.
Challenges related to sustainability arise in all areas of human activity, but with a significant impact on the environment considering that the construction industry is held accountable for nearly one-third of the world's final energy consumption. The aim of this paper is to assess through the use of the Bob-Dencsak specific model a sustainable slope design taking into account environmental, economic, and safety variables. Thus, analysis was performed on four intervention works, two versions of reinforced concrete retaining walls and two versions of reinforced soil with a biaxial geogrid, which ensure the stability of a slope that serves as a base for an access road to an ecological landfill located in Alba County, Romania. The study's analysis points out that reinforced soil retaining walls are far more sustainable, providing the best sustainability indices, which is also supported by the impact of geogrids compared to reinforced concrete, thus resulting in the finding that reinforced concrete is less sustainable, achieving increases of up to 23% for embodied energy and 66% of CO2 emissions in the atmosphere. Finally, the paper provides recommendations for future research on the sustainability assessment of slopes, with the intention of reducing environmental damage, while keeping costs to a minimum.
Plastics thrown out as trash are an everlasting threat to our biosphere and ecosystem. A sustainable remedy within our reach is the use of agricultural biomass. Herein, the lignocellulosic residue of switchgrass biomass, extracted using alkaline and bleaching treatments and solubilized in ZnCl2 solution followed by crosslinking with calcium ions, is used to develop biodegradable films. The films have been characterized for color, transparency, thickness, moisture, water solubility, water absorption, water vapor permeability, tensile strength, elongation, and soil biodegradation. Mathematical modeling of the water absorption and biodegradation behavior have also been studied. The films are transparent, possess high tensile strength and low water vapor permeability, and biodegrade completely within 40 days at 30% soil moisture. The tensile strength and whiteness of films increase with CaCl2 concentration, but elongation, water absorption, water solubility, water vapor permeability, and biodegradation decrease. Overall, the strong and biodegradable switchgrass residue-based films open up a new window of opportunities to design and develop reusable, recyclable, and compostable films from underutilized, inexpensive, and abundant agricultural biomass contributing to the circular bioeconomy in a friendly and sus-tainable manner.
本文以新疆天山乌鲁木齐河源一号冰川退缩区为研究区域,通过210Pbex、137Cs放射性同位素测年和侵蚀性堆积地貌判定退缩区的年代演替序列,并据此设置了系列采样点,对土壤进行分层采样,测定样品总汞浓度等指标,计算各年代退缩区的汞累积速率,探究乌鲁木齐河源一号冰川退缩区土壤中汞的分布特征及其累积过程.结果表明:冰川退缩区土壤汞含量和汞储量随着退缩时间增长呈现出增加的趋势,各层土壤汞的平均含量由大到小依次为:0~5cm[(13.28±6.60)μg/kg]>5~10cm[(11.47±7.34)μg/kg]>10~15cm[(10.19±6.57)μg/kg]>基岩[(0.23±0.09)μg/kg];冰川退缩区植被生长促进了土壤汞的富集,退缩区内土壤汞浓度与土壤有机碳、氮含量呈显著正相关,而且由于植被生物量很小,退缩区土壤中汞的累积速率也较低(0.09~33.43μg/(m2·a),平均值为16.92μg/(m2·a));近250a来(1777年以来),天山一号冰川退缩区土壤汞累积速...
本文以新疆天山乌鲁木齐河源一号冰川退缩区为研究区域,通过210Pbex、137Cs放射性同位素测年和侵蚀性堆积地貌判定退缩区的年代演替序列,并据此设置了系列采样点,对土壤进行分层采样,测定样品总汞浓度等指标,计算各年代退缩区的汞累积速率,探究乌鲁木齐河源一号冰川退缩区土壤中汞的分布特征及其累积过程.结果表明:冰川退缩区土壤汞含量和汞储量随着退缩时间增长呈现出增加的趋势,各层土壤汞的平均含量由大到小依次为:0~5cm[(13.28±6.60)μg/kg]>5~10cm[(11.47±7.34)μg/kg]>10~15cm[(10.19±6.57)μg/kg]>基岩[(0.23±0.09)μg/kg];冰川退缩区植被生长促进了土壤汞的富集,退缩区内土壤汞浓度与土壤有机碳、氮含量呈显著正相关,而且由于植被生物量很小,退缩区土壤中汞的累积速率也较低(0.09~33.43μg/(m2·a),平均值为16.92μg/(m2·a));近250a来(1777年以来),天山一号冰川退缩区土壤汞累积速...