•We assessed the relationship between biodiversity and ecosystem multifunctionality of alpine meadows.•We used a neural network model to predict the importance of biodiversity to ecosystem ...multifunctionality.•Biodiversity collectively explains ecosystem multifunctional processes.•Species richness is an essential driver of ecosystem multifunctionality.
Exploring the spatial pattern of biodiversity in different dimensions and its relationship with ecosystem multifunctionality was one of the hot topics in ecological research, and elevation was an important topographic factor affecting biodiversity changes. The maintenance mechanism of ecosystem multifunctionality (EMF) relationship between different dimensions of biodiversity and ecosystem multifunctionality in alpine meadows on the eastern Qinghai-Tibetan Plateau was still unclear. This paper investigates the elevation patterns of species, functions, and phylogenetic diversity of plant communities in alpine meadows on the eastern Qinghai-Tibetan Plateau and their effects on EMF using factor analysis and the radial basis function (RBF) neural network model. The results showed that (1) the species and phylogenetic diversity indices (except MPD index) increased and then decreased with elevation; the functional diversity indices FRic and FEve showed a decreasing trend with elevation, while FDiv showed the opposite. (2) Ecosystem multifunctional indices for the five elevation gradients were 3000 m > 3250 m > 3500 m > 3750 m > 4000 m. There were significant correlations between biodiversity and ecosystem functions. Species richness, Simpson, FRic, and FDiv increased with increasing EMF, but the relationship between phylogenetic diversity and EMF was insignificant. (3) Among the biodiversity indices, species richness and functional richness indices had a greater impact on EMF and were also important drivers to explain changes in EMF, followed by PD indices. The high biodiversity of alpine meadows can contribute to the supply of multifunctional ecosystems, making them healthier and more stable.
In this work, a novel and robust electrochemical sensor was developed by modifying EDTA and β-cyclodextrin functionalized reduced graphene oxide (EDTA-β-CD-rGO) onto the Glassy carbon electrodes ...(GCE) to quantify 1,1-diphenyl-2-picryl-hydrazyl free radical (DPPH). The morphology and structures of the nanocomposite were characterized by the UV–vis spectroscopy, Fourier transform infrared (FT-IR) spectra, Scanning electronic microscope (SEM) and X-ray photoelectron spectroscopy (XPS). The nanocomposite exhibits great electrochemical signal enhancement towards DPPH oxidation, which attributes to the good electrical properties and high specific surface area of rGO along with the enrichment of amounts of DPPH onto the EDTA-β-CD-rGO/GCE by forming host-guest inclusion complex and chelated compounds with β-CD and EDTA, respectively. Under the optimal conditions, the linear range for DPPH was from 1.0 × 10
− 8
to 0.01 mol/L with a low detection limit of 3.0 × 10
− 9
mol/L. The sensor also showed the advantages of simple preparation, low cost, good stability and repeatability. These characteristics make the sensor promising for the detection of DPPH. Moreover, EDTA-β-CD-rGO showed strong DPPH scavenging activity, and it can be used as an artificially synthesized antioxidant.
Graphic abstract
EDTA-β-CD-rGO has been successfully synthesized via hydrothermal process. The nanocomposite shows great electrochemical signal enhancement towards DPPH oxidation not only owing to the large surface area and good electrical properties of rGO, but also due to incorporating amount of DPPH on the electrode by forming stable host–guest inclusion complexes and chelate compound with the presence of β-CD and EDTA, respectively. Meanwhile, EDTA-β-CD-rGO showed strong DPPH scavenging activity, and it can be used as an artificially synthesized antioxidant.
In this work, a novel electrochemical aptasensor was developed for sensitive and selective detection of myoglobin based on meso-tetra (4-carboxyphenyl) porphyrin-functionalized graphene-conjugated ...gold nanoparticles (TCPP-Gr/AuNPs). Due to its good electric conductivity, large specific surface area, and excellent mechanical properties, TCPP-Gr/AuNPs can act as an enhanced material for the electrochemical detection of myoglobin. Meanwhile, it provides an effective matrix for immobilizing myoglobin-binding aptamer (MbBA). The electrochemical aptasensor has a sensitive response to myoglobin in a linear range from 2.0 × 10
M to 7.7 × 10
M with a detection limit of 6.7 × 10
M (S/N = 3). Furthermore, the method has the merits of high sensitivity, low price, and high specificity. Our work will supply new horizons for the diagnostic applications of graphene-based materials in biomedicine and biosensors.
Economic developments and a lack of surface water resources often result in the overexploitation of the groundwater, which lead to groundwater funnels, land subsidence, groundwater pollution and ...other environmental geological disasters. This phenomenon is particularly serious in developing countries. In such circumstances, to accurately calculate the regulation storage of the underground aquifers, evaluate the capacity of an underground reservoir and to restore the groundwater funnels are of great significance to the control of groundwater overexploitation at a global scale. In this paper, a calculation method for regulation storage of an underground reservoir is introduced, and the storage capacity is determined. First, the groundwater overdraft and hydrogeological materials are collected, and the geological structure to partition the hydrogeological units is analyzed. The representative drills are chosen, and profiles are drawn to describe the spatial distributions of the aquifers. Then, based on the lithology, the study area is divided into different hydrogeological units. Finally, the regulation storage is calculated using the volumetric method. In addition, using Surfer software, the second method is used to verify the calculation results. Through the establishment of a comprehensive evaluation index system for the underground reservoir regulation capacity, a gray correlation analysis of the index system is conducted, and the indices are reduced to six. Then, the regulation capacity is evaluated using the projection pursuit model. Taking Weifang of northern China as an example, the regulation storage is calculated and the regulation capacity is evaluated.
The estimation of design flood is mainly focused on the peak flow and the volume, ignoring the underlying surface factor and flood rising and falling process. Three basic conceptual hydrological ...models, XAJ, TANK and SCS, are selected and applied for design flood estimation in two small-scale basins of northern China. Model parameter calibration is based on both the optimization algorithm SCE-UA and artificial adjusting, by using a combined objecting function of flood peak, volume and process. Each model singles out a set of optimal parameters as input to simulate the design flood process. The simulation results are compared with original engineering design standards and instantaneous unit hydrograph method. The results show that the XAJ model has the best performance in simulating the 100-year design flood in study basins. The SCS model also gives acceptable results, but the TANK model on the other hand in an underestimated flood peak with a prolonged recession period, which is not likely to be applicable. This study is to test the applicability of the conceptual hydrological models in simulating the design flood process in small-scale watersheds and should be a supplement to the traditional methods and further deliberation to a ungauged basin. Starting from the most basic models with simple structures, it is hoped that the methodology can be transferred to more complicated and physically based models with more realistic description of the rainfall-runoff transformation mechanism and dynamic mechanism for climate change.
Appropriate location for installing purifier in the bedroom can improve the air quality inside the bedroom. With standard k-ε turbulence model, this paper made the numerical simulation analysis of ...pollutant concentration distribution after installation of indoor air purification device, and found the best place to put purifier. Numerical simulation results show that formaldehyde concentration is low in the place of strength turbulence intensity and the place of outlet. When purification device is located in the opposite of bed, purification effect is the best, and purification speed also the fastest.
Leukemia-associated alternative splicing of IKZF1 can result in proteins with loss of one to four copies of its N-terminal zinc finger domains (N-ZnF). The best characterized pathogenic splice ...isoforms, Ik-6 and Ik-8, have been commonly found in BCR-ABL1+ acute lymphoblastic leukemia (ALL) and a subset of BCR-ABL1-like ALL. Infantile and childhood ALL that express these pathogenic IKZF1 isoforms have shown inferior clinical outcomes and can be resistant to tyrosine kinase inhibitors. Using ALL cell lines, we designed and validated a method to detect abnormal IKZF1 transcripts. In the SUP-B15 leukemia cell line, we noted novel IKZF1 transcripts that include both an Ik-6 splice and a transcript with a 14 base pair insertion at the C-terminus. There was also increased IKZF2 protein in SUP-B15 as compared to other ALL lines. Expression of Ik-6 could be suppressed by treatment with the pro-apoptotic type II histone deacetylase inhibitor givinostat. In 17 adult ALL samples, we noted the Ik-6 isoforms in 6 of 15 BCR-ABL1−, and 1 of 2 BCR-ABL1+ cases, with Ik-8 also expressed in one case. Cases with Ik-6 expression showed inferior survival as well as older age at presentation, lower expression of CD10 and more commonly a diploid karyotype.
A dual signal and label-free electrochemical aptasensor for mucin 1 was constructed based on hemin/graphene@PdPtNPs nanocomposite (H-Gr@PdPtNPs). Hemin attached on the graphene surface not only ...improves the solubility of graphene and acts as an in-situ electrochemical probe but also exhibits excellent peroxidase-like properties to electrocatalyze the reduction of H2O2. PdPtNPs also show outstanding catalytic capacity to the reduction of H2O2 and provide numerous binding sites for loading dDNA (mucin 1 aptamer and cDNA) to form the sensing interface. In the presence of mucin 1, due to the specific affinity between aptamer and mucin 1, double helix would be induced dissociation and the aptamer would be pulled off from the electrode. As a result, the electrochemical signals of hemin and H2O2 were recovered. Based on these properties, the label-free and sensitive dual signal electrochemical biosensor for mucin 1 detection has been developed. The one is differential pulse voltammetry (DPV) signal of hemin and the other is chronoamperometry signal arisen from the catalytic reduction of H2O2. The linear ranges for mucin 1 were 8.0 pg mL−1 to 80 ng mL−1 and 0.8 pg mL−1 to 80 ng mL−1 with the limit of detection 2.5 pg mL−1 and 0.25 pg mL−1 by DPV and chronoamperometry, respectively. The recovery of mucin 1 in human blood serum samples was from 95.0% to 104.2%. The detection platform does not need signal labeling which greatly reduced the sophisticated and expensive procedures. The aptasensor provide a promising strategy for the determination of mucin 1 in clinical diagnostics.
•A dual signal and label-free electrochemical aptansensor for mucin 1 was constructed based on H-Gr@PdPtNPs.•Hemin acts as an in-situ probe and also can catalyze electrochemical reaction of H2O2 due to its high peroxidase activity.•DPV signal of hemin and chronoamperometry signal of H2O2 were used for mucin 1 detection.•The method displayed wide linear range and low limit of detection.•The aptasensor was applied to detect mucin 1 in human blood serum samples.
A triple-amplified and ratiometric electrochemical aptasensor for CA125 was designed based on hemin–graphene/SH-β-cyclodextrin@PdPt nanoflower (H-Gr/SH-β-CD@PdPtNF) composites and an exonuclease I ...(Exo I)-assisted strategy. In the nanocomposite, hemin acts as an internal reference signal owing to the reversible heminox/heminred pair. PdPtNFs can significantly improve the electron transfer rate. SH-β-CD can efficiently enrich quercetin probes through host–guest recognition and increase the second indicator signal. In the presence of CA125, due to the specific binding between the aptamer and CA125, the conformational change of dsDNA (designed by the CA125 aptamer and its complementary DNA) results in the release of quercetin embedded in dsDNA. Subsequently, the free quercetin and DNA fragments are enriched on the H-Gr/SH-β-CD@PdPtNF-modified electrode. Thus, an enhanced oxidation peak from quercetin (I Q) and a reduced peak from hemin (I hemin) can indicate the same biological identification event. In addition, the recycling amplification of CA125 by Exo I can effectively assist the increase of the quercetin signal. The value of I Q/I hemin is linear with the concentration of CA125 in the range from 6.0 × 10–4 to 1.0 × 103 ng/mL, and the limit of detection is 1.4 × 10–4 ng/mL. The recovery of CA125 in human blood serum samples was from 99.2 to 104.4%. The proposed sensor is sensitive and reliable, which provides an avenue for the development of triple amplification and ratiometric signal strategies for detecting tumor markers in clinical diagnostics.
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