ABSTRACT
Reactive oxygen species (ROS) are widely considered to the effective therapeutics for fighting bacterial infections especially those associated with biofilm. However, biofilm microenvironments including hypoxia, limited H2O2, and high glutathione (GSH) level seriously limit the therapeutic efficacy of ROS-based strategies. Herein, we have developed an acidic biofilm microenvironment-responsive antibacterial nanoplatform consisting of copper-dopped bovine serum albumin (CBSA) loaded with copper peroxide (CuO2) synthesized in situ and indocyanine green (ICG). The three-in-one nanotherapeutics (CuO2/ICG@CBSA) are capable of releasing Cu2+ and H2O2 in a slightly acidic environment, where Cu2+ catalyzes the conversion of H2O2 into hydroxyl radical (â¢OH) and consumes the highly expressed GSH to disrupt the redox homeostasis. With the assistance of an 808 nm laser, the loaded ICG not only triggers the production of singlet oxygen (1O2) by a photodynamic process, but also provides photonic hyperpyrexia that further promotes the Fenton-like reaction for enhancing â¢OH production and induces thermal decomposition of CuO2 for the O2-self-supplying 1O2 generation. The CuO2/ICG@CBSA with laser irradiation demonstrates photothermal-augmented multi-mode synergistic bactericidal effect and is capable of inhibiting biofilm formation and eradicating the biofilm bacteria. Further in vivo experiments suggest that the CuO2/ICG@CBSA can effectively eliminate wound infections and accelerate wound healing. The proposed three-in-one nanotherapeutics with O2/H2O2-self-supplied ROS generating capability show great potential in treating biofilm-associated bacterial infections. STATEMENT OF SIGNIFICANCE: Here, we have developed an acidic biofilm microenvironment-responsive nanoplatform consisting of copper-dopped bovine serum albumin (CBSA) loaded with copper peroxide (CuO2) synthesized in situ and indocyanine green (ICG). The nanotherapeutics (CuO2/ICG@CBSA) are capable of releasing Cu2+ and H2O2 in an acidic environment, where Cu2+ catalyzes the conversion of H2O2 into â¢OH and consumes the overexpressed GSH to improve oxidative stress. With the aid of an 808 nm laser, ICG provides photonic hyperpyrexia for enhancing â¢OH production, and triggers O2-self-supplying 1O2 generation. CuO2/ICG@CBSA with laser irradiation displays photothermal-augmented multi-mode antibacterial and antibiofilm effect. Further in vivo experiments prove that CuO2/ICG@CBSA effectively eliminates wound infection and promotes wound healing. The proposed three-in-one nanotherapeutics show great potential in treating biofilm-associated bacterial infections.
ABSTRACT
Actin remodeling proteins are important in immune diseases and regulate cell cytoskeletal responses. These responses play a pivotal role in maintaining the delicate balance of biological events, protecting against acute or chronic inflammation in a range of diseases. Cofilin (CFL) and actin depolymerization factor (ADF) are potent actin-binding proteins that cut and depolymerize actin filaments to generate actin cytoskeleton dynamics. Although the molecular mechanism by which actin induces actin cytoskeletal reconstitution has been studied for decades, the regulation of actin in the inflammatory process has only recently become apparent. In this paper, the functions of the actin cytoskeleton and ADF/cofilin superfamily members are briefly introduced, and then focus on the role of CFL1 in inflammatory response.
ABSTRACT
With global climate change leading to increasing intensity and frequency of droughts, as well as the growing problem of soil salinization, these factors significantly affect crop growth, yield, and resilience to adversity. Oats are a cereal widely grown in temperate regions and are rich in nutritive value; however, the scientific literature on the response of oat to drought and salt stress has not yet been analyzed in detail. This study comprehensively analyzed the response of oat to drought stress and salt stress using data from the Web of Science core database and bibliometric methods with R (version4.3.1), VOSviewer (version 1.6.19), and Citespace (version6.3.1.0) software. The number of publications shows an increasing trend in drought stress and salt stress in oat over the past 30 years. In the field of drought-stress research, China, the United States, and Canada lead in terms of literature publication, with the most academic achievements being from China Agricultural University and Canadian Agricultural Food University. The journal with the highest number of published papers is Field Crops Research. Oat research primarily focuses on growth, yield, physiological and biochemical responses, and strategies for improving drought resistance. Screening of drought-tolerant genotypes and transformation of drought-tolerant genes may be key directions for future oat drought research. In the field of salt-stress research, contributions from China, the United States, and India stand out, with the Chinese Academy of Agricultural Sciences and Inner Mongolia Agricultural University producing the most significant research results. The largest number of published articles has been found in the Physiologia Plantarum journal. Current oat salt-stress research primarily covers growth, physiological and biochemical responses, and salt-tolerance mechanisms. It is expected that future oat salt research will focus more on physiological and biochemical responses, as well as gene-editing techniques. Despite achievements under single-stress conditions, combined drought and salt-stress effects on oat remain understudied, necessitating future research on their interaction at various biological levels. The purpose of this study is to provide potential theoretical directions for oat research on drought and salt stress.
ABSTRACT
Psoriasis is a prevalent skin disease affecting approximately 1%-3% of the population and imposes significant medical, social and economic burdens. Psoriasis involves multiple organs and is often complicated with obesity, diabetes, dyslipidemia, and hypertension. Because of the benefits of lipid-lowering agents and antidiabetic medications for psoriasis, metabolic abnormalities possibly play a pathogenic role in psoriasis.This review focuses on the impacts of a variety of metabolic disorders on psoriasis and the underlying mechanisms.In psoriasis, enhanced glycolysis, glutamine metabolism and altered fatty acid composition in the psoriatic lesion and plasma result in the excessive proliferation of keratinocytes and secretion of inflammatory cytokines. Altered metabolism is associated with the activation of MTORC signaling pathway and transcription factors such as HIF and S6K1. Therefore, MTORC1 can be a target for the treatment of psoriasis. Additionally, there are diabetes drugs and lipid-lowering drugs including TZDs, GLP-1 RAs, Metformin, statins and fibrates, which improve both metabolic levels and psoriasis symptoms.
Subject(s)
Psoriasis , Psoriasis/drug therapy , Psoriasis/metabolism , Psoriasis/complications , Humans , Metabolic Diseases/drug therapy , Metabolic Diseases/metabolism , Hypoglycemic Agents/therapeutic use , Hypoglycemic Agents/pharmacology , Signal Transduction/drug effectsABSTRACT
Psoriasis is characterized by excessive angiogenesis, with increased distortion and dilation of the dermal blood vessels. These vascular alterations are ascribed, at least in part, to the changes in dermal microvascular endothelial cell functions. However, despite the recognition of vascular normalization as an emerging strategy for the treatment of psoriasis, in-depth studies of human dermal microvascular endothelial cells (HDMECs) have been missing. The difficulty of isolation and culture of HDMECs has impeded the study of endothelial dysfunction in psoriasis. Researchers have done a great deal of work to study the abnormal characteristics of keratinocytes, fibroblasts, and leukocytes in psoriatic skin tissue. Recently, with successful isolation of HDMECs from psoriasis, great progress has been made in the elucidation of the pathogenic role of these cells in psoriasis. It is of great therapeutic significance to study the molecular mechanism of HDMECs in psoriasis. We review here the abnormalities of HDMECs in psoriasis.
Subject(s)
Endothelial Cells , Microvessels , Neovascularization, Pathologic , Psoriasis , Skin , Humans , Psoriasis/pathology , Psoriasis/physiopathology , Endothelial Cells/pathology , Endothelial Cells/metabolism , Skin/blood supply , Skin/pathology , Microvessels/pathology , Microvessels/physiopathology , Microvessels/metabolism , Animals , Signal Transduction , Phenotype , AngiogenesisABSTRACT
Autoimmune skin disease is a kind of heterogeneous disease with complicated pathogenesis. Many factors such as genetic, infectious, environmental and even psychological factors may interact together to trigger a synergistic effect for the development of abnormal innate and adaptive immune responses. Although the exact mechanisms remain unclear, recent evidence suggests that pyroptosis plays a pivotal role in the development of autoimmune skin disease. The feature of pyroptosis is the first formation of pores in cellular membranes, then cell rupture and the release of intracellular substances and pro-inflammatory cytokines, such as interleukin-1 beta (IL-1ß) and IL-18. This hyperactive inflammatory programmed cell death damages the homeostasis of the immune system and advances autoimmunity. This review briefly summarises the molecular regulatory mechanisms of pyrin domain-containing protein 3 (NLRP3) inflammasome and gasdermin family, as well as the molecular mechanisms of pyroptosis, highlights the latest progress of pyroptosis in autoimmune skin disease, including systemic lupus erythematosus, psoriasis, atopic dermatitis and systemic scleroderma and attempts to identify its potential advantages as a therapeutic target or prognostic biomarker for these diseases.
Subject(s)
Autoimmune Diseases , Inflammasomes , NLR Family, Pyrin Domain-Containing 3 Protein , Pyroptosis , Humans , Autoimmune Diseases/immunology , Autoimmune Diseases/metabolism , Inflammasomes/metabolism , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , Skin Diseases/immunology , Animals , Phosphate-Binding Proteins/metabolism , Interleukin-1beta/metabolism , Scleroderma, Systemic/immunology , Lupus Erythematosus, Systemic/immunology , Intracellular Signaling Peptides and Proteins/metabolism , Psoriasis/immunology , Psoriasis/metabolism , Autoimmunity , Interleukin-18/metabolism , Dermatitis, Atopic/immunologyABSTRACT
ErbB3-binding protein 1(Ebp1) has two isoforms, p42 Ebp1 and p48 Ebp1, both of which can regulate cell growth and differentiation. But these isoforms often have opposite effects, including contradictory roles in regulation of cell growth in different tissues and cells. P48 Ebp1 belongs to the full-length sequence, while conformational changes in the crystal structure of p42 Ebp1 reveals a lack of an α helix at the amino terminus. Due to the differences in the structures of these two isoforms, they have different binding partners and protein modifications. Ebp1 can function as both an oncogene and a tumor suppressor factor. However, the underlying mechanisms by which these two isoforms exert opposite functions are still not fully understood. In this review, we summarize the genes and the structures of protein of these two isoforms, protein modifications, binding partners and the association of different isoforms with diseases.
Subject(s)
Protein Isoforms , Humans , Protein Isoforms/metabolism , Animals , RNA-Binding Proteins/metabolism , RNA-Binding Proteins/chemistry , Adaptor Proteins, Signal Transducing/metabolism , Adaptor Proteins, Signal Transducing/chemistry , CCAAT-Enhancer-Binding Proteins/metabolism , Neoplasms/metabolism , Protein BindingABSTRACT
Alfalfa (Medicago sativa L.) is one of the most important forage crops in the world. Drought is recognized as a major challenge limiting alfalfa production and threatening food security. Although some literature reviews have been conducted in this area, bibliometric reviews based on large amounts of published data are still lacking. In this paper, a bibliometric analysis of alfalfa drought stress from 1998-2023 was conducted using the Web of Science Core Collection database in order to assess global trends in alfalfa drought stress research and to provide new directions for future research. The results showed that the annual publication output maintained an increase in most years, with China and the United States contributing significantly to the field. Most of the journals published are specialized journals in botany, environmental science, soil science and crop science, as well as related agribusiness journals. "plant growth" and "yield" were the most frequently used keywords, reflecting the important purpose of research in this field. And two main research directions were identified: research on drought response mechanism of alfalfa and exploration of drought-resistant technology. In addition, physiological, biochemical, and molecular responses of drought tolerance and high yield in alfalfa, transgenics, and microbial fertilizer research have been hot research topics in recent years and may continue in the future. The ultimate goal of this paper is to provide a foundational reference for future research on alfalfa's drought resistance and yield optimization mechanisms, thereby enhancing the crop's application in agricultural production.
ABSTRACT
BACKGROUND: Psoriasis is a prevalent chronic inflammatory dermatosis characterized by excessive proliferation of keratinocytes. Protein lysine 2-hydroxyisobutyrylation (Khib) is a newly identified post-translational modification that regulates various biological processes. Abnormal Khib modification has been closely associated with the development of autoimmune diseases. OBJECTIVE: To investigate the abnormal Khib profile and its pathogenic role in psoriasis. METHODS: We utilized liquid chromatography-tandem mass spectrometry to analyze Khib-modified proteins in the epidermis of psoriasis and healthy controls. Mutated cells and mice with downregulated Ebp1Khib210 were generated to investigate its functional effects in psoriasis. RESULTS: The omic analysis revealed dysregulation of Khib modification in psoriatic lesions, exhibiting a distinct profile compared to controls. We observed the downregulation of Ebp1Khib210 in psoriatic lesions and IMQ-induced psoriatic mice. Notably, the expression of Ebp1Khib210 was upregulated in psoriatic patients following effective treatment. Decreased Ebp1Khib210 enhanced keratinocyte viability, proliferation, and survival while inhibiting apoptosis in vitro. Additionally, Pa2g4K210A mice with downregulated Ebp1Khib210 exhibited more severe psoriatic lesions and enhanced keratinocyte proliferation. Moreover, we found that Ebp1K210A mutation increased the interaction between Ebp1 and nuclear Akt, thereby inhibiting MDM2-mediated TIF-IA ubiquitination, and resulting to increased rRNA synthesis and keratinocyte proliferation. The downregulation of Ebp1Khib210 was attributed to inflammation-induced increases in HDAC2 expression. CONCLUSION: Our findings demonstrate that downregulation of Ebp1Khib210 promotes keratinocyte proliferation through modulation of Akt signaling and TIF-IA-mediated rRNA synthesis. These insights into Khib modification provide a better understanding of the pathogenesis of psoriasis and suggest potential therapeutic targets.
ABSTRACT
Background: The systemic immune-inflammation index (SII),as measured by lymphocyte, neutrophil and platelet counts in peripheral blood, is regarded as a favorable indicator of both inflammatory state and immune response. Psoriasis is an immune-mediated disease notable for its chronic inflammation of the entire system. Our research sought to explore the latent link between psoriasis and SII. Methods: We performed a cross-sectional investigation utilizing data extracted from the National Health and Nutrition Examination Survey (NHANES, 2009-2014). Employing multivariate linear regression models and subgroup analysis, we sought to uncover the association between SII and psoriasis. Results: This study enrolled a total of 17,913 participants as part of its research cohort. Our multivariate linear regression analysis revealed a notable and positive correlation between SII and psoriasis [1.013 (1.000, 1.026)]. As SII tertiles increased, the risk of psoriasis demonstrated an upward trend. The significant dependence on this positive association were maintained in women, BMI(≥ 30 kg/m2),non-stroke and non-cancer subjects in subgroup analysis and interaction tests. Furthermore, we identified a significant association between SII and psoriasis, characterized by two consecutive inverted U-shaped patterns. Notably, the analysis revealed the most prominent inflection point at a specific value of 797.067. Conclusions: The results indicate a significant correlation between elevated SII levels and the presence of psoriasis. However, to corroborate and strengthen these results, additional large-scale prospective studies are required.
Subject(s)
Psoriasis , Research , Humans , Female , Cross-Sectional Studies , Nutrition Surveys , Inflammation , Psoriasis/epidemiologyABSTRACT
The formation of soil in karst ecosystem has always been a scientific problem of great concern to human beings. Algae can grow on the exposed and non-nutrition carbonate surface, inducing and accelerating weathering of rock substrates, thus promoting soil formation. Yet the actual contribution of algae to solutional weathering intensity remains unclear. In this study, we performed weathering simulation experiment on two algae species (Klebsormidium dissectum (F.Gay) H.Ettl & G.Gärtner and Chlorella vulgaris Beijerinck), which were screened from carbonated rock surfaces from a typical karst region in South China. The results showed: (1) both algae have solutional weathering effect on carbonate rock, (2) there is no difference of solutional intensity observed, yet the solutional modes are different, suggesting different ecological adaptative strategies, (3) algae on carbonate rocks have higher carbonic anhydrase activity (CAA) and secrete more extracellular polysaccharide (EPS), accelerating rock weathering. (4) The absolute dissolution amount of carbonate rock with algae participation is 3 times of that of without algae. These results indicate the significant impact of terrestrial algae on carbonate rock solutional weathering and provides quantitative evidence that terrestrial algae are pioneer species. It also contributes to our further understanding of soil formation in karst ecosystems in South China.
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OBJECTIVE: Increased angiogenesis is a pathological feature of psoriasis, but the pathomechanisms of angiogenesis in psoriasis are not clear. Interleukin-17A (IL-17A) is the major effect factor in the pathogenesis of psoriasis. Our results showed that IL-17A can promote angiogenesis and cause endothelial cell inflammation. Autophagy plays an important role not only in regulating inflammation, but also in regulating angiogenesis. Whether angiogenesis in psoriasis is related to autophagy remains unclear. In this study, we treated human umbilical vein endothelial cells (HUVECs) with IL-17A to simulate increased angiogenesis to study whether increased angiogenesis in psoriasis is related to autophagy. METHODS AND RESULTS: Our results showed that treatment of HUVECs with IL-17A significantly increased angiogenesis and expression levels of mRNA for multiple proinflammatory cytokines (CCL20, IL-8, CCL2, IL-6, and IL-1ß) and, while decreasing intracellular levels of nitric oxide (NO) and NO synthase (NOS) activity. Moreover, IL-17A inhibited autophagy as shown that IL-17A significantly increased expression levels of LC3II and p62 proteins. Induction of autophagy ameliorated IL-17A-mediated inflammatory response and inhibited angiogenesis, accompanied by increased p-AMPKα(Thr172) and p-ULK1(Ser555) expression, and decreased p-mTOR(Ser2448) and p-ULK1(Ser757) expression. Furthermore, inhibition of either AMPK or lysosomal acidification completely overrode autophagy-induced changes in angiogenesis and NOS activity. Finally, induction of autophagy decreased apoptosis and caspase-3 activity in IL-17A-treated HUVECs. CONCLUSIONS: These results showed that IL-17A is involved in angiogenesis and inflammatory response by inhibiting autophagy through AMPK signaling pathway, suggesting that autophagy may be a new therapeutic target for psoriasis.
Subject(s)
Interleukin-17 , Psoriasis , Humans , AMP-Activated Protein Kinases/pharmacology , AMP-Activated Protein Kinases/therapeutic use , Autophagy , Endothelial Cells/pathology , Hyperplasia , Inflammation/pathology , Interleukin-17/metabolism , Psoriasis/drug therapyABSTRACT
Given afferent functions, sensory nerves have recently been found to exert efferent effects and directly alter organ physiology. Additionally, several studies have highlighted the indirect but crucial role of sensory nerves in the regulation of the physiological function of osteoclasts. Nonetheless, evidence regarding the direct sensory nerve efferent influence on osteoclasts is lacking. In the current study, we found that high levels of efferent signals were transported directly from the sensory nerves into osteoclasts. Furthermore, sensory hypersensitivity significantly increased osteoclastic bone resorption, and sensory neurons (SNs) directly promoted osteoclastogenesis in an in vitro coculture system. Moreover, we screened a novel neuropeptide, Cyp40, using an isobaric tag for relative and absolute quantitation (iTRAQ). We observed that Cyp40 is the efferent signal from sensory nerves, and it plays a critical role in osteoclastogenesis via the aryl hydrocarbon receptor (AhR)-Ras/Raf-p-Erk-NFATc1 pathway. These findings revealed a novel mechanism regarding the influence of sensory nerves on bone regulation, i.e., a direct promoting effect on osteoclastogenesis by the secretion of Cyp40. Therefore, inhibiting Cyp40 could serve as a strategy to improve bone quality in osteoporosis and promote bone repair after bone injury.
Subject(s)
Bone Resorption , Osteogenesis , Humans , Peptidylprolyl Isomerase/metabolism , Osteoclasts/metabolism , Bone Resorption/metabolismABSTRACT
Introducing cover crops into maize rotation systems is widely practiced to increase crop productivity and achieve sustainable agricultural development, yet the potential for crop rotational diversity to contribute to environmental benefits in soils remains uncertain. Here, we investigated the effects of different crop rotation patterns on the physicochemical properties, enzyme activities, microbial biomass and microbial communities in soils from field experiments. Crop rotation patterns included (i) pure maize monoculture (CC), (ii) maize-garlic (CG), (iii) maize-rape (CR) and (iv) maize-annual ryegrass for one year (Cir1), two years (Cir2) and three years (Cir3). Our results showed that soil physicochemical properties varied in all rotation patterns, with higher total and available phosphorus concentrations in CG and CR and lower soil organic carbon and total nitrogen concentrations in the maize-ryegrass rotations compared to CC. Specifically, soil fertility was ranked as CG > Cir2 > CR > Cir3 > CC > Cir1. CG decreased enzyme activities but enhanced microbial biomass. Cir2 decreased carbon (C) and nitrogen (N) acquiring enzyme activities and soil microbial C and N concentrations, but increased phosphorus (P) acquiring enzyme activities and microbial biomass P concentrations compared to CC. Soil bacterial and fungal diversity (Shannon index) were lower in CG and Cir2 compared to CC, while the richness (Chao1 index) was lower in CG, CR, Cir1 and Cir2. Most maize rotations notably augmented the relative abundance of soil bacteria, including Chloroflexi, Gemmatimonadetes and Rokubacteria, while not necessarily decreasing the abundance of soil fungi like Basidiomycota, Mortierellomycota and Anthophyta. Redundancy analysis indicated that nitrate-N, ammonium-N and microbial biomass N concentrations had a large impact on soil bacterial communities, whereas nitrate-N and ammonium-N, available P, soil organic C and microbial biomass C concentrations had a greater effect on soil fungal communities. In conclusion, maize rotations with garlic, rape and ryegrass distinctly modify soil properties and microbial compositions. Thus, we advocate for garlic and annual ryegrass as maize cover crops and recommend a two-year rotation for perennial ryegrass in Southwest China.
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The mutual optical intensity (MOI) model is a partially coherent radiation propagation tool that can sequentially simulate beamline optics and provide beam intensity, local degree of coherence and phase distribution at any location along a beamline. This paper extends the MOI model to non-ideal two-dimensional (2D) optical systems, such as ellipsoidal and toroidal mirrors with 2D figure errors. Simulation results show that one can tune the trade-off between calculation efficiency and accuracy by varying the number of wavefront elements. The focal spot size of an ellipsoidal mirror calculated with 100â ×â 100 elements gives less than 0.4% deviation from that with 250â ×â 250 elements, and the computation speed is nearly two orders of magnitude faster. Effects of figure errors on 2D focusing are also demonstrated for a non-ideal ellipsoidal mirror and by comparing the toroidal and ellipsoidal mirrors. Finally, the MOI model is benchmarked against the multi-electron Synchrotron Radiation Workshop (SRW) code showing the model's high accuracy.
ABSTRACT
Bistable cholesteric liquid crystals have promising application prospects in various fields, such as smart windows and displays. However, the long-term stability of two individual states is not easy to achieve, hindering their practical use. In this research, the bistable feature was enhanced by constructing a microsphere-type polymer with a liquid-crystalline epoxy/thiol monomer in negative dielectric anisotropic cholesteric liquid crystals. Spectroscopic and optical examinations revealed that either the transparent planar state or the opaque focal conic state can be maintained without the aid of an external field. Moreover, they can be switched to each other by applying a high- or low-frequency electric field. Further, factors such as the chemical structure of thiol compounds, curing temperature and curing time were investigated to explore their influences on the micro morphology of the polymer and thereby the electro-optical properties. In addition, the frequency-dependent driving scheme was analysed. Finally, bistable switching was demonstrated using an optimized sample. This energy-efficient bistable film shines light on future applications in smart windows, photonic paper and other electro-optical devices.
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Psoriasis is a chronic inflammatory skin disease. The histopathological features of psoriasis include excessive proliferation of keratinocytes and infiltration of immune cells. The S100 proteins are a group of EF-hand Ca2+-binding proteins, including S100A2, -A7, -A8/A9, -A12, -A15, which expression levels are markedly upregulated in psoriatic skin. These proteins exert numerous functions such as serving as intracellular Ca2+ sensors, transduction of Ca2+ signaling, response to extracellular stimuli, energy metabolism, and regulating cell proliferation and apoptosis. Evidence shows a crucial role of S100 proteins in the development and progress of inflammatory diseases, including psoriasis. S100 proteins can possibly be used as potential therapeutic target and diagnostic biomarkers. This review focuses on the pathogenic role of S100 proteins in psoriasis.
Subject(s)
Psoriasis , S100 Proteins , Humans , S100 Proteins/metabolism , S100 Calcium Binding Protein A7/metabolism , Skin/pathology , Keratinocytes/metabolismABSTRACT
Introduction: The production of root exudates with biological nitrification inhibition (BNI) effects is a strategy adopted by ammonium-N (NH4+-N) tolerant plant species that occur in N-limited environments. Most knowledge on BNI comes from plant species that occur in acidic soils. Methods: Here, combining field sampling and laboratory culture, we assessed the BNI-capacity of Leymus chinensis, a dominant grass species in alkaline grasslands in eastern Asia, and explored why L. chinensis has BNI ability. Results and discussion: The results showed that L. chinensis has strong BNI-capacity. At a concentration of 1 mg mL-1, L. chinensis' root exudates inhibited nitrification in soils influenced by Puccinellia tenuiflora by 72.44%, while DCD only inhibited it by 68.29%. The nitrification potential of the soil of L. chinensis community was only 53% of the P. tenuiflora or 41% of the Suaeda salsa community. We also showed that the supply of NH4+-N driven by L. chinensis' BNI can meet its requirements . In addition, NH4+-N can enhance plant adaptation to alkaline stress by regulating pH, and in turn, the uptake of nitrate-N (NO3--N). We further demonstrated that the regulatory function of NH4+-N is greater than its nutritional function in alkaline environment. The results offer novel insights into how L. chinensis adapts to high pH and nutrient deficiency stress by secreting BNIs, and reveal, for the first time, differences in the functional roles of NH4+-N and NO3--N in growth and adaptation under alkaline conditions in a grass species.
ABSTRACT
Manipulating and integrating the microstructures at different scales is crucial to tune the electrical and thermal properties of a given compound. High-pressure sintering can modify the multiscale microstructures and thus empower the cutting-edge thermoelectric performance. In this work, the high-pressure sintering technique followed by annealing is adopted to prepare Gd-doped p-type (Bi0.2Sb0.8)2(Te0.97Se0.03)3 alloys. First, the high energy of high-pressure sintering promotes the reduction of grain size, thus increasing the content of 2D grain boundaries. Next, high-pressure sintering induces strong interior strain, where 1D dense dislocations are generated near the strain field. More interestingly, the rare-earth element Gd with a high melting temperature is dissolved into the matrix via high-pressure sintering, thus promoting the formation of 0D extrinsic point defects. This concurrently improves the carrier concentration and density-of-state effective mass, resulting in an enhanced power factor. In addition, the integrated 0D point defects, 1D dislocations, and 2D grain boundaries by high-pressure sintering strengthen phonon scattering, thereby achieving a low lattice thermal conductivity of 0.5 Wm-1 K-1 at 348 K. Consequently, a maximum zT value of â¼1.1 at 348 K is achieved in the 0.4 at % Gd-doped (Bi0.2Sb0.8)2(Te0.97Se0.03)3 sample. This work demonstrates that high-pressure sintering enables microstructure modification to enhance the thermoelectric performance of Bi2Te3-based and other bulk materials.