Comparative Assessment of APTT Reagents for Evaluating Anticoagulant Sensitivity of Fucosylated Glycosaminoglycans (FGs) Derived from Sea Cucumbers.

Fucosylated glycosaminoglycans (FGs) derived from sea cucumbers exhibit potent intrinsic Xase (iXase) inhibition, anticoagulation, and antithrombosis. Plasma activated partial thromboplastin time (APTT), a widely used screening test worldwide, is crucial for evaluating anticoagulant efficacy. However, the applicability of these commercially available APTT reagents for assessing anticoagulation of FGs remains unreported. In this study, we investigated the disparity between ellagic acid and colloidal silica APTT reagents in evaluating anticoagulation of dHG-5 and dHLFG-4, two depolymerized FGs, and elucidated the underlying rationale. The results demonstrated that dHG-5 and dHLFG-4 exhibited heightened sensitivity to the ellagic acid APTT reagent both in vitro and in vivo, and did not significantly affect the activation of APTT reagents for plasma. In addition, both ellagic acid and colloidal silica APTT reagents inhibited the anti-iXase of dHG-5 and dHLFG-4, and the inhibition of the ellagic acid APTT reagent was less pronounced compared to the colloidal silica APTT reagent. These findings suggest that the reduced impact of the ellagic acid APTT reagent on the anti-iXase activity of dHG-5 and dHLFG-4 is responsible for the increased sensitivity in plasma APTT analysis. This study offers valuable insights into the characteristics of two APTT reagents applied for assessing the anticoagulant activity of FG-related compounds.

Potential benefits and risks of solar photovoltaic power plants on arid and semi-arid ecosystems: an assessment of soil microbial and plant communities.

Exponential increase in photovoltaic installations arouses concerns regarding the impacts of large-scale solar power plants on dryland ecosystems. While the effects of photovoltaic panels on soil moisture content and plant biomass in arid ecosystems have been recognized, little is known about their influence on soil microbial communities. Here, we employed a combination of quantitative PCR, high-throughput sequencing, and soil property analysis to investigate the responses of soil microbial communities to solar panel installation. We also report on the responses of plant communities within the same solar farm. Our findings showed that soil microbial communities responded differently to the shading and precipitation-alternation effects of the photovoltaic panels in an arid ecosystem. By redirecting rainwater to the lower side, photovoltaic panels stimulated vegetation biomass and soil total organic carbon content in the middle and in front of the panels, positively contributing to carbon storage. The shade provided by the panels promoted the co-occurrence of soil microbes but inhibited the abundance of 16S rRNA gene in the soil. Increase in precipitation reduced 18S rRNA gene abundance, whereas decrease in precipitation led to decline in plant aboveground biomass, soil prokaryotic community alpha diversity, and dehydrogenase activity under the panels. These findings highlight the crucial role of precipitation in maintaining plant and soil microbial diversities in dryland ecosystems and are essential for estimating the potential risks of large-scale solar power plants on local and global climate change in the long term.

Trace metals in sediment from Chaohu Lake in China: Bioavailability and probabilistic risk assessment.

Bioavailability-based probabilistic risk assessment is an effective approach for risk characterization of trace metals towards aquatic species. However, it has not been routinely applied in lake management due to limited research. In this study, Chaohu Lake (Anhui Province, China) was selected as a case study, and total and bioavailable concentrations of trace metals in surface sediment were investigated using chemical extraction and diffusive gradients in thin films (DGT). Probabilistic risk assessment (PRA) was performed using Monte Carlo simulation. In addition, the species sensitivity distribution (SSD) was constructed using acute toxicity data to model the sensitivity of aquatic species towards metals. Three evaluation methods, namely, toxic units based on total content, modified potential ecological risk index (RI) based on chemical fractionation and DGT-SSD coupled PRA, were implemented and compared. Results showed that trace metals, especially Cd, were significantly affected by anthropogenic activities. Chemical fractionation analysis revealed that the majority of Cd was readily available to aquatic organisms, while Cr was stable under normal conditions. Toxic units based on the total content demonstrated that metals in sediment were at 91.6 % low and 8.4 % medium toxicity levels, while the modified RI based on chemical fractionation found toxicity levels of 84.1 % low and 15.9 % medium. Furthermore, the combined toxicity calculated from DGT-SSD coupled PRA showed that trace metals in sediment had a 24.8 % probability of toxic effects towards aquatic organisms, with Cu, Zn, Cd, and Ni being the main contributors. Comparative analysis suggested that the DGT-SSD coupled PRA could provide a more objective and scientific evidence for lake management with regard to metal contamination.

Source tracing with cadmium isotope and risk assessment of heavy metals in sediment of an urban river, China.

The Nanfei River was one of dominant inflowing rivers of the fifth largest freshwater Chaohu Lake in China, which had been subjected to increasing nutrients and contaminants from population expansion, rapid industrialization and agricultural intensification in recent decades. In present study, surface sediment from the Nanfei River was collected to investigate the anthropogenic impact on distribution and bioavailability of heavy metals. Possible Cd sources along the river were constrained by using Cd isotope signatures and labile concentrations of heavy metals in sediment were determined through the DGT technique for risk assessment. Results showed that Cd in river sediment showed greatest enrichment (EF 0.8-9.4), indicating massive pollution from anthropogenic activities. Among the various possible Cd source materials, urban road dust, industrial soil and chicken manure, displayed higher Cd abundance and enrichment that might contribute to Cd accumulation in river sediment. Cadmium isotopic composition in river sediment was ranged from -0.21 ± 0.01‰ to 0.13 ± 0.03‰, whereas yielded relative variation from -0.31 ± 0.02‰ to 0.23 ± 0.01‰ in source materials. Accordingly, Cd sources along the river were constrained, i.e. traffic and industrial activities in the upper and middle reaches whereas agricultural activities in the lower reaches. Furthermore, the evaluation on ecological risk of heavy metals in sediment on basis of SQGs and DGT-labile concentrations demonstrated that Pb and Zn might pose higher risk on aquatic species. The present study confirmed that Cd isotopes were promising source tracer in environmental studies.

Carbon footprint, yield and economic performance assessment of different mulching strategies in a semi-arid spring maize system.

Crop productivity maximization while minimizing carbon emissions is of critical importance for achieving sustainable agriculture. Socio-economic and ecological benefits should be taken together under the circumstance of stagnant farming profitability and climatic variability. The effectiveness of various mulching strategies in rain-fed semiarid areas has been confirmed, but scarce the comprehensive evaluations of the conventional and new mulching strategies in terms of yield, economic benefit, and carbon footprint based on life cycle assessment (LCA) have been conducted. Hence, a two-year field experiment was conducted on maize (Zea mays L.) crop to explore the effects of four mulching strategies (PM: plastic-film mulching, SM: maize straw mulching, BM: biodegradable-film mulching, and NM: no mulching) on the yield, net return, greenhouse gas (GHG) emissions, and carbon footprint (CF). The results revealed that PM and BM significantly increased maize yield by 11.3-13.3% and 9.4-10.6%. PM marginally raised the net return by 2.0-2.4% whereas BM slightly reduced it by 4.6-8.8% relative to NM. Unexpectedly, the yield and net return were the lowest under SM, and intensified N2O emissions, GWPdirect, and yield-scaled GWPdirect were observed. When the GHGs using LCA concept and SOC sequestration rate were considered, the lowest net GWP (1804.1-1836.4 kg CO2-eq ha-1) and CF (148.9-119.9kg CO2-eq t-1) were observed in the SM treatment due to the boost of soil organic carbon (SOC) sequestration. Conversely, PM and BM significantly increased the net GWP and CF compared to NM. When the tradeoffs between the high production, high net return and low net GWP were assessed by an integrated evaluation framework, the NM was recommended as an efficient low-carbon agricultural practice in the rain-fed semiarid areas.

Polydopamine nanodots-based cost-effective nanoprobe for glucose detection and intracellular imaging.

The cellular glucose detection remains a vital topic, which could provide some essential information about the glucose-based pathological and physiological processes. In this study, a smart polydopamine nanodots-based cost-effective fluorescence turn-on nanoprobe (denoted as PDA-Ag-GOx) for intracellular glucose detection is established. Silver nanoparticles (AgNPs) are directly formed in one step by the reduction of fluorescent polydopamine nanodots (PDADs) which have much phenolic hydroxyls on the surface. The fluorescence of PDADs could be quenched by AgNPs through surface plasmon-enhanced energy transfer (SPEET) from donor PDADs to acceptor AgNPs. Glucose oxidase (GOx) is modified on the PDA-Ag NPs by covalent bond. In the presence of glucose, GOx could catalyze glucose to produce H2O2 and gluconic acid. The generated acid and H2O2 would degrade AgNPs into Ag+, the PDADs release and restore its fluorescence. The proposed nanoprobe has some advantages, such as cost-effective, easy preparation, and excellent selectivity toward glucose, which could be successfully utilized to intracellular glucose imaging.

Risk assessment and management of preoperative venous thromboembolism following femoral neck fracture.

BACKGROUND: Limited studies are available to investigate the prevalence of preoperative venous thromboembolism (VTE) in elderly patients with femoral neck fractures. Our primary aim was to determine the incidences of VTE and its risk or protective factors in such patient population. The secondary objective was to evaluate the need of therapeutic anticoagulation for isolated calf muscular venous thrombosis (ICMVT) prior to femoral neck fracture surgery. METHODS: This is a retrospective case-control study, including 301 femoral neck fracture patients who were admitted to our institution between January 2014 and March 2017. Bilateral Doppler ultrasonography was performed in each of the patients as a preoperative VTE screening. The event rate of VTE was calculated, and significant risk or protective factors were determined by using a multivariate logistic regression model. Patients with ICMVT were divided into anticoagulation and no anticoagulation groups to assess the efficacy and safety of preoperative therapeutic anticoagulation. Intraoperative blood loss, drainage volume, blood transfusion, perioperative hemoglobin change, and rate of thrombosis extension were compared between the two groups. RESULTS: The overall preoperative incidence of VTE in patients with femoral neck fracture was 18.9% (57/301), in which deep vein thrombosis (DVT) was 18.9% and pulmonary embolism (PE) was 1%. Among the DVT cases, 77.2% (44/57) were ICMVTs. Multiple fractures (odds ratio [OR] = 9.418; 95% confidence interval [CI] = 2.537 to 34.96), coexisting movement disorder (OR = 3.862; 95% CI = 1.658 to 8.993), bed rest for more than 7 days (OR = 2.082; 95% CI = 1.011 to 4.284) as well as elevated levels of D-dimer (OR = 1.019; 95% CI = 1.002 to 1.037) and fibrinogen (OR = 1.345; 95% CI = 1.008 to 1.796) led to an increase in the risk of VTE, while the recent use of antiplatelet drug (OR = 0.424; 95% CI = 0.181 to 0.995) and prophylactic anticoagulation (OR = 0.503; 95% CI = 0.263 to 0.959) decreased the risk of VTE. For the 39 patients with ICMVT undergoing femoral neck fracture surgery, there were no significant differences in the rate of thrombosis extension between anticoagulation and no anticoagulation groups, but significantly decreased postoperative hemoglobin was observed in the anticoagulation group. CONCLUSION: Our findings showed a high prevalence of preoperative VTE in elderly patients with femoral neck fracture, with risk factors identified. We found that the most detected VTE were ICMVTs. Our study suggested that a direct surgery without preoperative use of therapeutic anticoagulation for ICMVT would not reduce the risk of thrombus extension, and the therapeutic use of anticoagulation may worsen postoperative anemia.