Arbuscular mycorrhizal fungi (AMF) establish symbiotic interaction with 80% of known land plants. It has a pronounced impact on plant growth, water absorption, mineral nutrition, and protection from ...abiotic stresses. Plants are very dynamic systems having great adaptability under continuously changing drying conditions. In this regard, the function of AMF as a biological tool for improving plant drought stress tolerance and phenotypic plasticity, in terms of establishing mutualistic associations, seems an innovative approach towards sustainable agriculture. However, a better understanding of these complex interconnected signaling pathways and AMF-mediated mechanisms that regulate the drought tolerance in plants will enhance its potential application as an innovative approach in environmentally friendly agriculture. This paper reviews the underlying mechanisms that are confidently linked with plant-AMF interaction in alleviating drought stress, constructing emphasis on phytohormones and signaling molecules and their interaction with biochemical, and physiological processes to maintain the homeostasis of nutrient and water cycling and plant growth performance. Likewise, the paper will analyze how the AMF symbiosis helps the plant to overcome the deleterious effects of stress is also evaluated. Finally, we review how interactions between various signaling mechanisms governed by AMF symbiosis modulate different physiological responses to improve drought tolerance. Understanding the AMF-mediated mechanisms that are important for regulating the establishment of the mycorrhizal association and the plant protective responses towards unfavorable conditions will open new approaches to exploit AMF as a bioprotective tool against drought.
In this work, a simple and label-free electrochemical biosensor is developed for microRNA (miRNA) detection on the basis of an arched probe mediated isothermal exponential amplification reaction ...(EXPAR). The arched probe assembled on the electrode surface consists of two strands that are partially complementary to each other at both ends. The target can hybridize with the complementary sequence of the arched structure, leading to the cleavage of the probe. The strand fixed on the surface of the electrode self-assembles, in the presence of hemin, to G-quadruplex unit, yielding electrochemical signals. The other strand liberated into the solution triggers the EXPAR to recycle and regenerate targets. This method exhibits ultrahigh sensitivity toward miRNA with detection limits of 5.36 fM and a detection range of 3 orders of magnitude. The biosensor is capable of discriminating a single-nucleotide difference between concomitant miRNA and performs well in analyzing crude extractions from cancer cell lines.
Global climate change is predicted to have large impacts on the phenology and reproduction of alpine plants, which will have important implications for plant demography and community interactions, ...trophic dynamics, ecosystem energy balance, and human livelihoods. In this article we report results of a 3‐year, fully factorial experimental study exploring how warming, snow addition, and their combination affect reproductive phenology, effort, and success of four alpine plant species belonging to three different life forms in a semiarid, alpine meadow ecosystem on the central Tibetan Plateau. Our results indicate that warming and snow addition change reproductive phenology and success, but responses are not uniform across species. Moreover, traits associated with resource acquisition, such as rooting depth and life history (early vs. late flowering), mediate plant phenology, and reproductive responses to changing climatic conditions. Specifically, we found that warming delayed the reproductive phenology and decreased number of inflorescences of Kobresia pygmaea C. B. Clarke, a shallow‐rooted, early‐flowering plant, which may be mainly constrained by upper‐soil moisture availability. Because K. pygmaea is the dominant species in the alpine meadow ecosystem, these results may have important implications for ecosystem dynamics and for pastoralists and wildlife in the region.
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•Janus MoSSe shows a high sensitivity and selectivity to SO2 and its Se-layer shows higher response to SO2 than its S-layer.•The work function based sensor is more gear to Janus MoSSe ...due to intense work function change induced by SO2 adsorption.•Our work reveals the intrinsic mechanism for modulation of applied strain on the SO2-sensing performance of Janus MoSSe.•The SO2-sensing performance on Se-layer of MoSSe exhibits much higher sensitivity to biaxial strain than S-layer.
Four main SF6 decompositions (H2S, SO2, SOF2 and SO2F2) adsorption on S-layer and Se-layer of the Janus MoSSe monolayer was investigated by first principles calculation in this work. Our calculations implied that both the S-layer and Se-layer of Janus MoSSe are more sensitive and selective to SO2 than other three SF6 decompositions and the Se-layer is more sensitive than the S-layer. Furthermore, it is found that the applied strain can more effectively modulate the sensing performance of Janus MoSSe than that of normal transition metal chalcogenides (TMDs). Our further investigation indicated that the unique interior electric field of Janus MoSSe played an important role in enhancing the modulation effect. In sum, we concluded that the Janus MoSSe monolayer is a highly strain-sensitive gas sensing material to detect SF6 decompositions. Our work can help avoid harm from hazardous SF6 decompositions.
In this work, a facile electrochemical sensor based on poly(diallyldimethylammonium chloride) (PDDA) functionalized graphene (PDDA-G) and graphite was fabricated. The composite electrode exhibited ...excellent selectivity and sensitivity towards uric acid (UA), owing to the electrocatalytic effect of graphene nanosheets and the electrostatic attractions between PDDA-G and UA. The anodic peak current of UA obtained by cyclic voltammetry (CV) increased over 10-fold compared with bare carbon paste electrode (CPE). And the reversibility of the oxidation process was improved significantly. Differential pulse voltammetry (DPV) was used to determine UA in the presence of ascorbic acid (AA) and dopamine (DA). It was found that all of oxidation peaks of three species could be well resolved, and the peak current of UA was much stronger than the other two components. More importantly, considerable-amount of AA and DA showed negligible interference to UA assay. The calibration curve for UA ranged from 0.5 to 20μmolL−1 with a correlation coefficient of 0.9934. The constructed sensor has been employed to quantitatively determine UA in urine samples.
•A facile UA sensor based on PDDA-G and graphite was fabricated.•The electrode showed excellent sensitivity and selectivity towards UA detection.•The sensor can eliminate the interferences from excess AA and DA.•UA in human urine samples were detected directly without pretreatment.
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► CoHCF nanoparticles modified MWCNTs/graphite electrode use for electrochemistry on electrophoresis microchip for the first time. ► Simultaneous, rapid, and sensitive electrochemical ...detection of hydrazine and isoniazid in real samples. ► An exemplary work of CME sensor assembly onto microchip for determination of analytes with environmental significance. ► Manifestation of the applicability and flexibility of CME sensor for electroanalysis on microfluidic chip.
Nanomaterial-based electrochemical sensor has received significant interest. In this work, cobalt hexacyanoferrate modified multi-walled carbon nanotubes/graphite composite electrode was electrochemically prepared and exploited as an amperometric detector for microchip electrophoresis. The prepared sensor displayed rapid and sensitive response towards hydrazine and isoniazid oxidation, which was attributed to synergetic electrocatalytic effect of cobalt hexacyanoferrate and multi-walled carbon nanotubes. The sensitivity enhancement with nearly two orders of magnitude was gained, compared with the bare carbon paste electrode, with the detection limit of 0.91
μM (
S/
N
=
3) for hydrazine. Acceptable repeatability of the microanalysis system was verified by consecutive eleven injections of hydrazine without chip and electrode treatments, the RSDs for peak current and migration time were 3.4% and 2.1%, respectively. Meanwhile, well-shaped electrophoretic peaks were observed, mainly due to fast electron transfer of electroactive species on the modified electrode. The developed microchip-electrochemistry setup was successfully applied to the determination of hydrazine and isoniazid in river water and pharmaceutical preparation, respectively. Several merits of the novel electrochemical sensor coupled with microfluidic platform, such as comparative stability, easy fabrication and high sensitivity, hold great potential for hydrazine compounds assay in the lab-on-a-chip system.
•A simple and sensitive electrochemical sensor was established for the determination of NMN based on p-m-ABSA film modified glassy carbon electrode.•The fabricated sensor was irreversible and ...adsorption controlled in the process of detecting NMN.•Common interfering substances hardly affected the modified electrode performance.•The modified electrode shows a considerable sensitivity, stability and reproducibility to NMN.
In the present study, a novel and facile poly-m-amino-benzenesulfonic acid (p-m-ABSA) film on glassy carbon electrode (GCE) was developed using pulse potentiostatic method (PPM), which is employed with the oxidative polymerization of m-ABSA at anode potential. Meanwhile, a simple and sensitive sensor was fabricated to detect normetanephrine (NMN), which is one of the significant diagnostic markers for diseases. Compared with bare GCE, the p-m-ABSA film prepared on GCE surface has the advantage of increasing electrode surface area and active sites distinctly, thus obviously improving the electrocatalytic activity. The results demonstrated that the developed electrochemical sensor exhibited high sensitivity, stability, selectivity and excellent electrocatalytic activity towards NMN. The surface morphology of p-m-ABSA/GCE was characterized by scanning electron microscopy (SEM), indicating that the electrode surface had a layered structure. The preparation conditions and analysis methods of sensors were studied in detail. Under optimum conditions, peak current and concentrations of NMN were linearly related well from 0.5 to 30.0 µM with a limit of detection (S/N = =3) of 0.17 µM. Moreover, this modified sensor has also been successfully used for the detection of NMN in human serum samples.
In this paper, freshness monitoring model on small larimichthys polyactis based on multiple sensor array system (MSAS) combined with total volatile basic nitrogen (TVB-N) examination was studied. ...Larimichthys polyactis was obtained and prepared as detecting samples. MSAS was developed based on volatile gas content of the fish samples. Meanwhile, TVB-N was examined to provide quality reference for MSAS measurement. MSAS responding data were processed by principal component analysis (PCA) and non-linear signal analysis model. Larimichthys polyactis freshness deciding model was developed by non-linear fitting between signal processing features and TVB-N parameters. Results indicated that the method studied in this work presented good freshness deciding accuracy for larimichthys polyactis. This method also presented some advantages including rapid analysis, easy operation, and low cost. It is promising in aquatic products quality raped determination.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
The Great Wall of China was a military facility that has been continuously built and used for over thousands of years, and is a world-renowned cultural heritage site today. The plants growing on top ...surface of the Great Wall caused the damage of the Great Wall, but the process of removing these plants may further damage the body of the Great Wall. In this paper, based on the Analytic Hierarchy Process and the expert Delphi method, we selected 13 specific indices from three Constraint Layer factors, and then estimated and identified 45 species/categories of plants on top surface of the Dazhuangke section of the Great Wall. The results showthe constitution and the evaluation gradeof the evaluation system. The factor of Disruptive Effects plays the main guidance role in the evaluation system of the Constraint Layer; The indices of Impact on the Near Side Wall is the core element of the evaluation model with the highest weight of the Standard Layer. And the “Preservation”, “Partial Preservation”and “Removal” recommendations were given based on three evaluation grade (from Grade I to Grade III). This research provides scientific basis for the protective repair of the Great Wallheritage as well as "Garden on the Great Wall".
Metal-organic frameworks (MOFs) have been extensively used as modified materials of electrochemical sensors in the food industry and agricultural system. In this work, two kinds of copper-based MOFs ...(Cu-MOFs) with a two dimensional (2D) sheet-like structure and three dimensional (3D) octahedral structure for H
O
detection were synthesized and compared. The synthesized 2D and 3D Cu-MOFs were modified on the glassy carbon electrode to fabricate electrochemical sensors, respectively. The sensor with 3D Cu-MOF modification (HKUST-1/GCE) presented better electrocatalytic performance than the 2D Cu-MOF modified sensor in H
O
reduction. Under optimal conditions, the prepared sensor displayed two wide linear ranges of 2 μM-3 mM and 3-25 mM and a low detection limit of 0.68 μM. In addition, the 3D Cu-MOF sensor exhibited good selectivity and stability. Furthermore, the prepared HKUST-1/GCE was used for the detection of H
O
in milk samples with a high recovery rate, indicating great potential and applicability for the detection of substances in food samples. This work provides a convenient, practical, and low-cost route for analysis and extends the application range of MOFs in the food industry, agricultural and environmental systems, and even in the medical field.
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