摘要:
This paper investigates the impact of environmental courts on pollution abatement at the city level, utilizing the establishment of environmental courts in China as a quasi-experiment. A spatial difference-in-differences model is employed to control for the influence of environmental courts on neighbouring non-pilot cities. The results underscore the effectiveness of environmental courts in reducing industrial pollutant emissions, evident in both the pilot areas and adjacent non-pilot areas. The influence of environmental courts on pollution abatement is more pronounced in cities characterized by stronger environmental regulations, higher level of economic agglomeration, and higher level of openness. Mechanism analysis shows that environmental courts promote environmental supervision by governments, public participation in environmental protection, and expenditure on environmental governance by firms. In summary, this paper unveils the tangible effects of environmental courts on pollution abatement and elucidates the mechanisms underpinning this relationship. These findings provide timely implications for regulators concerned with environmental protection.
摘要:
Cancer immunotherapy, particularly with immune checkpoint inhibitors, has revolutionized the paradigm of cancer treatment. Nevertheless, the efficacy of cancer immunotherapy remains limited in most clinical settings due to the lack of a preexisting antitumor T-cell response in tumors. Therefore, the clinical outcomes of cancer immunotherapy must be improved crucially. With increased awareness of the importance of the innate immune response in the recruitment of T cells, as well as the onset and maintenance of the T cell response, great interest has been shown in activating the cGAS-STING signaling pathway to awaken the innate immune response, thereby orchestrating both innate and adaptive immune responses to induce tumor clearance. However, tumor cells have evolved to overexpress ectonucleotide pyrophosphate phosphodiesterase 1 (ENPP1), which degrades the immunotransmitter 2',3'-cGAMP and promotes the production of immune-suppressing adenosine, resulting in inhibition of the anticancer immune response in the tumor microenvironment. Clinically, ENPP1 overexpression is closely associated with poor prognosis in patients with cancer. Conversely, depleting or inhibiting ENPP1 has been verified to elevate extracellular 2',3'-cGAMP levels and inhibit the generation of adenosine, thereby reinvigorating the anticancer immune response for tumor elimination. A variety of ENPP1 inhibitors have recently been developed and have demonstrated significant promise for cancer immunotherapy. In this review, we provide an overview of ENPP1, dissect its immunosuppressive mechanisms, and discuss the development of ENPP1 inhibitors with the potential to further improve the efficacy of cancer immunotherapy.
期刊:
Global Change Biology,2024年30(2):e17158- ISSN:1354-1013
通讯作者:
Wang, JJ
作者机构:
[Wang, Jianjun; Wen, Shuailong; Jiang, Shuyu; Han, Lei; Hu, Ang; Zhong, Jicheng] Chinese Acad Sci, Nanjing Inst Geog & Limnol, Key Lab Lake & Watershed Sci Water Secur, Nanjing, Peoples R China.;[Jiang, Shuyu] Nanjing Normal Univ, Coll Life Sci, Nanjing, Peoples R China.;[Han, Lei] Hunan Agr Univ, Coll Resources & Environm, Changsha, Peoples R China.;[Jang, Kyoung-Soon] Korea Basic Sci Inst, Biochem Anal Team, Cheongju, South Korea.;[Tanentzap, Andrew J.] Univ Cambridge, Dept Plant Sci, Cambridge, England.
通讯机构:
[Wang, JJ ] C;Chinese Acad Sci, Nanjing Inst Geog & Limnol, Key Lab Lake & Watershed Sci Water Secur, Nanjing, Peoples R China.
关键词:
carbon quality temperature hypothesis;carbon-climate feedback;chemodiversity;functional traits;geography;global warming;greenhouse gas;lake ecosystems
摘要:
The mean value of temperature sensitivity of organic carbon decomposition in lake sediments is 1.78 ± 0.62. The quantity of sediment organic carbon determines the absolute rate of decomposition, while the quality of organic carbon determines the sensitivity of decomposition to warming. At both molecular and compositional levels, functional traits of DOM revealed the positive correlation between Q10 and biochemical recalcitrance, thus supporting the carbon quality temperature hypothesis. Abstract Organic carbon decomposition in lake sediments contributes substantially to the global carbon cycle and is strongly affected by temperature. However, the magnitude of temperature sensitivity (Q10) of decomposition and the underlying factors remain unclear at the continental scale. Carbon quality temperature (CQT) hypothesis asserts that less reactive and more recalcitrant molecules tend to have higher temperature sensitivities, but its support is challenged by complex composition of organic matter and environmental constraints. Here, we quantified Q10 of the sediments across 50 freshwater ecosystems along a 3500 km north–south transect, and characterized the quality of sediment dissolved organic carbon with chemodiversity reflected in molecular richness, functional traits (i.e., molecular weight, bioavailability, etc.) and composition. We further included classic environmental variables, such as climatic, physicochemical and microbial factors, to explore how Q10 is constrained by these factors or carbon quality. We found that Q10 varied greatly across lakes, with the mean value of 1.78 ± 0.62, but showed nonsignificant latitudinal pattern. Q10 was primarily predicted by chemodiversity and showed an increasing trend with the biochemical recalcitrance indicated by traits such as aromaticity and standard Gibb's Free Energy at both molecular and compositional levels. This suggests that carbon quality is the crucial determinant of Q10 in lakes, supporting the CQT hypothesis. Moreover, Q10 decreased linearly with the increase of molecular richness, implying that the resistance of decomposition to warming is associated with higher molecular diversity. Compared with the structural equation model containing only environmental variables, inclusion of chemodiversity increased 32.8% of the explained variation in Q10, and chemodiversity was the only driver showing direct effects. Collectively, this study illustrates the importance of chemodiversity in shaping the pattern of Q10, and has significant implications for accurately predicting the carbon turnover in lake ecosystems in the context of global warming.
摘要:
Self-constructed water-in-oil emulsions can be stabilized by a natural pentacyclic triterpenoid, betulin. A higher betulin concentration (3%) results in smaller emulsion droplet sizes. Microscopy, confocal laser scanning microscopy and rheology indicate that the stabilizing mechanism is attributed to betulin crystals on the emulsion interface and within the continuous phase, thereby enabling excellent freeze/thaw and thermal stability. The betulin Pickering emulsion (1%) significantly increased betulin bioaccessibility (22.4%) compared to betulin alone (0.2%) and betulin-oil physical mixture (7.9%). A higher level of betulin at 3% leads to smaller emulsion particle size, potentially resulting in a greater surface area. This, in return, promotes a higher release of free fatty acids (FFA), contributing to the release and solubilization of betulin from emulsions. Additionally, it leads to the formation of micelles, further increasing betulin bioaccessibility (29.3%). This study demonstrates Pickering emulsions solely stabilized by phytochemical betulin provides an innovative way to improve its bioaccessibility.
摘要:
Micromelalopha sieversi (Staudinger, 1892) is a significant pest of Poplar trees in China. In this study, we used high-throughput sequencing to sequence the whole mitochondrial genome of M. sieversi. The length of the genome was 15,373 base pairs. The nucleotide composition was 39.8%, 11.5%, 8.0%, and 40.7% for A, C, G, and T, respectively. We used the maximum-likelihood method to construct a molecular phylogenetic tree based on complete mitogenome sequences of 19 Noctuoidea species as ingroups and five Geometroidea species as outgroups. The results indicate that the genus Micromelalopha is closely related to the genus Clostera in family Notodontidae.
摘要:
Chilling is a major abiotic stress affecting rice growth, development and geographical distribution. Plant vacuolar processing enzymes (VPEs) contribute to the seed storage protein processing and mediate the programmed cell death by abiotic and biotic stresses. However, little is known about the roles of plant VPEs in cold stress responses and tolerance regulation. Here, we found that OsVPE2 was a chilling-responsive gene. The early-indica rice variety Xiangzaoxian31 overexpressing OsVPE2 was more sensitive to chilling stress, whereas the OsVPE2-knockout mutants generated by the CRISPR-Cas9 technology exhibited significantly enhanced chilling tolerance at the seedling stage without causing yield loss. Deficiency of OsVPE2 reduces relative electrolyte leakage, accumulation of toxic compounds such as reactive oxygen species and malondialdehyde, and promotes antioxidant enzyme activities under chilling stress conditions. It was indicated that OsVPE2 mediated the disintegration of vacuoles under chilling stress, accompanied by the entry of swollen mitochondria into vacuoles. OsVPE2 suppressed the expression of genes that have a positive regulatory role in antioxidant process. Moreover, haplotype analysis suggested that the natural variation in the OsVPE2 non-coding region may endow OsVPE2 with different expression levels, thereby probably conferring differences in cold tolerance between japonica and indica sub-population. Our results thus reveal a new biological function of the VPE family in regulating cold resistance, and suggest that the gene editing or natural variations of OsVPE2 can be used to create cold tolerant rice varieties with stable yield.
通讯机构:
[Zhou, N ] H;Hunan Agr Univ, Hunan Engn Res Ctr Biochar, Changsha 410128, Peoples R China.;Hunan Agr Univ, Coll Chem & Mat Sci, Changsha 410128, Peoples R China.
摘要:
Transition-metal-catalyzed reactive oxygen species (ROS) play an important role in existing bactericidal systems, but there are some problems, such as poor stability, ease of dissolution, and difficulty in reusing. To address the issue of stability, we have developed a sufficient electron-donating (SED) system. In the presence of the two most active transition metals with multiple valences, several as-formed redox pairs can provide sufficient electrons, and then effectively trigger the reduction of H2O/O-2 to produce O-1(2), <middle dot>OH and <middle dot>O-2(-) without any assistance from extra energy or other active oxidants. Consequently, the SED system showed 100% removal efficiency for Escherichia coli in 2 h, and also showed remarkable stability and reusability with 85% inactivation after 11 repetitions. It is worth noting that <middle dot>OH and O-1(2) play a major role in the bactericidal process. While <middle dot>O-2(-) mainly plays a role in promoting the formation of O-1(2) and <middle dot>OH.
作者机构:
[Chen, Yinke; Peng, Yan; Teng, Zhenning; Duan, Meijuan; Ye, Nenghui; Qin, Zhonge; Liu, Bohan; Yu, Huihui; Ye, NH; Meng, Shuan; Lv, Jiahan; Duan, MJ] Hunan Agr Univ, Coll Agron, Hunan Prov Key Lab Rice Stress Biol, Changsha 410128, Peoples R China.;[Teng, Zhenning; Zhang, Jianhua; Yu, Huihui] Chinese Univ Hong Kong, Sch Life Sci, Hong Kong 999077, Peoples R China.;[Teng, Zhenning; Zhang, Jianhua; Yu, Huihui] Chinese Univ Hong Kong, State Key Lab Agrobiotechnol, Hong Kong 999077, Peoples R China.;[He, YC; He, Yuchi] Hubei Univ, Sch Life Sci, State Key Lab Biocatalysis & Enzyme Engn, Wuhan 430000, Peoples R China.;[Zhang, Jianhua; Ye, Nenghui; Ye, NH] Hong Kong Baptist Univ, Dept Biol, Hong Kong 999077, Peoples R China.
通讯机构:
[He, YC ; Zhang, JH; Ye, NH ; Duan, MJ] H;[Zhang, JH ] C;Hunan Agr Univ, Coll Agron, Hunan Prov Key Lab Rice Stress Biol, Changsha 410128, Peoples R China.;Chinese Univ Hong Kong, Sch Life Sci, Hong Kong 999077, Peoples R China.;Chinese Univ Hong Kong, State Key Lab Agrobiotechnol, Hong Kong 999077, Peoples R China.
摘要:
Low-temperature germination (LTG) is an important agronomic trait for direct-seeding cultivation of rice (Oryza sativa). Both OsMYB30 and OsTPP1 regulate the cold stress response in rice, but the function of OsMYB30 and OsTPP1 in regulating LTG and the underlying molecular mechanism remains unknown. Employing transcriptomics and functional studies revealed a sugar signaling pathway that regulates seed germination in response to low temperature (LT). Expression of OsMYB30 and OsTPP1 was induced by LT during seed germination, and overexpressing either OsMYB30 or OsTPP1 delayed seed germination and increased sensitivity to LT during seed germination. Transcriptomics and qPCR revealed that expression of OsTPP1 was upregulated in OsMYB30-overexpressing lines but downregulated in OsMYB30-knockout lines. In vitro and in vivo experiments revealed that OsMYB30 bound to the promoter of OsTPP1 and regulated the abundance of OsTPP1 transcripts. Overaccumulation of trehalose (Tre) was found in both OsMYB30- and OsTPP1-overexpressing lines, resulting in inhibition of alpha-amylase 1a (OsAMY1a) gene during seed germination. Both LT and exogenous Tre treatments suppressed the expression of OsAMY1a, and the osamy1a mutant was not sensitive to exogenous Tre during seed germination. Overall, we concluded that OsMYB30 expression was induced by LT to activate the expression of OsTPP1 and increase Tre content, which thus inhibited alpha-amylase activity and seed germination. This study identified a phytohormone-independent pathway that integrates environmental cues with internal factors to control seed germination. Low temperature increases the abundance of a transcription factor, which activates the biosynthesis of trehalose and consequently inhibits seed germination by impeding alpha-amylase activity in rice.
摘要:
Effects of steam explosion (SE) treatment (0.3-1.0 MPa, 30-90s) on the physicochemical and functional properties of dietary fiber (DF) extracted from tea residue were investigated. Results showed that SE led to the formation of porous and less compact microstructures of tea residues. Compared with the control sample (12.41 g/100 g), the content of soluble dietary fiber (SDF) was markedly increased by SE, reaching the maximum of 23.03 g/100 g when steam explored at 0.5 MPa for 90 s, due to the degradation of insoluble dietary fiber (IDF). The physicochemical and functional properties were significantly influenced by SE treatments. IDF exhibited decreased water holding capacity (WHC), swelling capacity (SC), oil holding capacity (OHC) after SE, whereas the physicochemical properties of SDF from SE-treated tea residues (0.3 MPa, 90s) were greatly improved. The glucose absorption capacity (GAC), cholesterol adsorption capacity (CAC), and nitrite ion adsorption capacity (NIAC) of both IDF and SDF showed trends of first increasing and then decreasing, indicating that excessive SE treatment resulted in poor properties of DF. These findings are of great value for the high-value utilization of agricultural by-product and development of functional foods.
摘要:
Cadmium (Cd) is a highly toxic heavy metal that can be readily absorbed by plants and enriched in human body. Rice (Oryza sativa L.) yield and grain quality are affected by excessive Cd in the soil. Therefore, understanding the mechanisms of Cd absorption, accumulation and detoxification in the root apex is crucial for developing low-Cd rice cultivars. After Cd treatment, Cd concentration in rice root tips (RT) was 1.4 times higher than that in basal roots (BR). To uncover the distinct molecular responses to Cd toxicity, we conducted transcriptomic, proteomic, and metabolomic analyses on the two root sections. The results revealed that the RT exhibited 1.2-2.0 fold higher transcript or protein abundance of several Cd-related transporters than the BR, including Nramp1, Nramp5, IRT1, and HMA3, thereby contributing to more Cd accumulation in the RT. Furthermore, multi-omics analysis unveiled that the RT had enhanced activity in 'phenylpropanoid metabolism', 'AsA-GSH cycle' and 'tryptophan metabolism', conferring the stronger antioxidant system. While the BR showed higher activation in 'cell wall remodeling' and 'terpenoid biosynthesis'. This comprehensive study provides insights into the regulatory network of genes, proteins and metabolites involved in the differential responses to Cd toxicity between rice root tips and mature zones.
摘要:
The species and contents of a-dicarbonyls in commercial black tea were examined, along with the effects of the manufacturing process and drying temperature on the formation of a-dicarbonyls. Ten a-dicarbonyls were quantified in commercial and in -process black tea samples by using UPLC-MS/MS and their derived quinoxalines. The a-dicarbonyls content in commercial black tea decreased significantly (p < 0.05) in the following order: 3deoxyglucosone > glucosone > 3-deoxypentosone = threosone > galactosone >= methylglyoxal = glyoxal >= 3deoxygalactosone = 3-deoxythreosone = diacetyl. Except for 3-deoxyglucosone and 3-deoxygalactosone, a further eight a-dicarbonyls were identified in all manufacturing steps of black tea. Except for the drying step, the rolling and fermenting played important roles in the formation of a-dicarbonyls. The total contents of a-dicarbonyls in black tea infusion ranged from 16.48 to 75.32 mu g/g based on our detected ten a-dicarbonyls.
摘要:
BACKGROUND: Dichlorvos (DDVP), as a highly effective insecticide, is widely used in agricultural production. However, DDVP residue in foodstuffs adversely affects human health. Conventional instrumental analysis can provide highly sensitive and accurate detection of DDVP, while the need of bulky and expensive equipment limits their application in resource-poor areas and on-site detection. Therefore, the development of easily portable sensing platforms for convenient, rapid and sensitive quantification of DDVP is very essential for ensuring food safety. RESULT: A portable colorimetric sensing platform for rapid and sensitive quantification of DDVP is developed based on nanozyme-participated highly efficient chromogenic catalysis. The Fe-Mn bimetallic oxide (FeMnOx) nanozyme possesses excellently oxidase-like activity and can efficiently catalyze oxidation of 3, 3', 5, 5'-tetramethylbenzidine (TMB) into a blue oxide with a very low Michaelis constant (K(m)) of 0.0522mM. The nanozyme-catalyzed chromogenic reaction can be mediated by DDVP via inhibiting the acetylcholinesterase (AChE) activity. Thus, trace DDVP concentration-dependent color evolution is achieved and DDVP can be sensitively detected by spectrophotometry. Furthermore, a smartphone-integrated 3D-printed miniature lightbox is fabricated as the colorimetric signal acquisition and processing device. Based on the FeMnOx nanozyme and smartphone-integrated lightbox system, the portable colorimetric sensing platform of DDVP is obtained and it has a wide linear range from 1 to 3000ngmL(-1) with a low limit of detection (LOD) of 0.267ngmL(-1) for DDVP quantification. SIGNIFICANCE: This represents a new portable colorimetric sensing platform that can perform detection of DDVP in foodstuffs with simplicity, sensitivity, and low cost. The work not only offers an alternative to rapid and sensitive detection of DDVP, but also provides a new insight for the development of advanced sensors by the combination of nanozyme, 3D-printing and information technologies.
通讯作者:
Xin Long Xu<&wdkj&>Xin Long Xu Xin Long Xu Xin Long Xu
作者机构:
[Liu, Shun Jia] Hunan Agr Univ, Sch Business, Changsha, Peoples R China.;[Zhu, Xiaoqian; Li, Jianping] Univ Chinese Acad Sci, Sch Econ & Management, Beijing, Peoples R China.;[Zhu, Xiaoqian; Li, Jianping] UCAS, MOE Social Sci Lab Digital Econ Forecasts & Policy, Beijing, Peoples R China.;[Wu, Dengsheng] Chinese Acad Sci, Inst Sci & Dev, Beijing, Peoples R China.;[Xu, Xin Long] Hunan Normal Univ, Coll Tourism, Changsha, Peoples R China.
通讯机构:
[Xin Long Xu; Xin Long Xu Xin Long Xu Xin Long Xu] C;College of Tourism, Hunan Normal University, Changsha, China<&wdkj&>Institute of Interdisciplinary Studies, Hunan Normal University, Changsha, China
摘要:
Existing studies on the environmental Kuznets curve (EKC) neglect the inverse effect of pollution transfer from environmental regulation interactions on pollution reduction from a risk analysis perspective. Based on the regional differentiated attitudes on the environmental regulation reached in risk communication by the risk awareness biases of multiple interest groups, this article clarifies the causality between risk communication and risk transfer based on multistakeholder engagement processes; furthermore, the article incorporates the simultaneous action of the technological innovation effect and pollution risk transfer effect to construct a spatial environmental hyperbolic model with a bidirectional correlation between pollution emissions and economic growth in different regions. To verify our model, we select the pollution from agricultural watersheds in China as a sample to examine the two inverse effects. The results demonstrate that (1) agricultural watershed pollution and economic growth show an inverted U-shaped relation and a U-shaped relation in the local region and adjacent regions, respectively; (2) the pollution reduction assessment of the classical EKC model can be largely attributed to pollution risk transfer behavior; and (3) the turning point of the U-shaped curve appears earlier than that of the inverted U-shaped curve in the spatial hyperbola model. The findings suggest that stakeholders should consider the risk awareness bias caused by the imbalance of regional economic development and the scenarios that provide a "haven" for pollution risk transfer. Moreover, our study expands the theoretical connotation of the classical EKC hypothesis and is more suitable for pollution reduction scenarios in developing countries.
摘要:
Efforts to curtail the escalating health threat posed by methicillin-resistant Staphylococcus aureus (MRSA), a formidable superbug, necessitate the development of innovative treatment strategies. Leveraging potential compounds from natural sources in tandem with antibiotics has emerged as a promising approach against MRSA. These strategies should enhance the antibiotic efficacy, reduce dosage and toxicity, and bypass MRSA resistance. In this study, we used a checkerboard assay to illustrate the significant synergistic anti-MRSA effect of shikimic acid (SA), a naturally occurring compound, and ceftiofur (CF). Time-kill curves further revealed that a combination of 1/4 of the minimum inhibitory concentration (MIC) of SA and 1/8 MIC of the sodium CF eradicated MRSA within 2h, with no noticeable toxicity observed with these concentrations. In vivo experiments confirmed that this combination therapy demonstrated robust antimicrobial activity against MRSA-induced bacteremia in mice, significantly reducing bacterial loads in the kidneys, liver, and spleen, attenuating inflammatory cell infiltration, and alleviating pathological damage. This study not only offers a compelling strategy, capitalizing on the synergistic potential of SA and CF, to rapidly address antibiotic resistance but also contributes significantly to the refinement of antimicrobial therapeutic strategies.
摘要:
Unsupervised cross-modal hashing is a topic of considerable interest due to its advantages in terms of low storage costs and fast retrieval speed. Despite the impressive achievements of existing solutions, two challenges remain unaddressed: (1) Semantic similarity obtained without supervision is not accurate enough, and (2) the preservation of similarity structures lacks effectiveness due to the neglect of both global and local similarity. This paper introduces a new method, Multi-Grained Similarity Preserving and Updating (MGSPU), to tackle these challenges. To overcome the first challenge, MGSPU employs a newly designed strategy to update the semantic similarity matrix, effectively generating a high-confidence similarity matrix by eliminating noise in the original cross-modal features. For the second challenge, a novel multi-grained similarity preserving method is proposed, aiming to enhance cross-modal hash code learning by learning consistency in multi-grained similarity structures. Comprehensive experiments on two widely used datasets with nine state-of-the-art competitors validate the superior performance of our method in cross-modal hashing.
摘要:
Pseudorabies virus (PRV) is one of the major viral pathogens leading to reproductive disorders in swine. However, little is known about the effects of PRV infection on porcine reproductive system. Ovarian granulosa cells are somatic cells surrounding oocytes in ovary and required for folliculogenesis. The present study aimed to investigate the interference of PRV on functions of porcine ovarian granulosa cells in vitro. Primary granulosa cells were isolated from porcine ovaries. To investigate the PRV infectivity, transmission electron microscopy (TEM) was used to check the presence of viral particles, and the expression of viral gE gene was detected by quantitative real-time PCR (qPCR) in PRV-inoculated cells. After PRV infection, cell viability was detected by MTS assay, Ki67 for proliferative status was determined by immunofluorescence assay (IFA), cell cycle and apoptosis were detected by flow cytometry, and progesterone (P4) and estradiol (E2) were determined by radioimmunoassay. The checkpoint genes of cell cycle and apoptosis-related proteins were studied by qPCR and western blotting. Virus particles were observed in the nucleus and cytoplasm of PRV-infected granulosa cells by TEM imaging, and the expression of viral gE gene increased in a time-dependent manner post infection. PRV infection inhibited cell viability and blocked cell cycle at S phase in porcine granulosa cells, accompanied by decreases in expression of Ki67 protein and checkpoint genes related to S phase. Radioimmunoassay revealed decreased levels in P4 and E2, and the expressions of key steroidogenic enzymes were also down-regulated post PRV-infection. In addition, PRV induced apoptosis with an increase in Bax expression and activation of caspase 9, and the phosphorylation of JNK, ERK and p38 MAPKs were significantly up-regulated in porcine ovarian granulosa cells post PRV infection. The data indicate that PRV causes infection on porcine ovarian granulosa cells and interferes the cell functions through apoptosis, and the MAPK signaling pathway is involved in the viral pathogenesis.
摘要:
Lemon essential oil (LEO) is a common natural antibacterial substance, and encapsulating LEO into nanoemulsions (NEs) can improve their stability and broaden its application. Our study aimed to investigate the bacterial inhibitory effect of LEO-NEs against Escherichia coli (E. coli). Results showed that the minimum inhibitory concentration (MIC) of LEO-NEs was 6.25mg/mL, and the time-kill curve showed that E. coli were significantly killed by LEO-NEs after 5h of treatment at 1MIC. Flow-cytometry analysis showed that LEO-NEs adversely affected the cell-membrane depolarisation, cell-membrane integrity, and efflux pump function of E. coli. Confocal laser scanning microscopy demonstrated that 8MIC of LEO-NEs induced changes in the cell-membrane permeability and cell-wall integrity of E. coli. Proteomic results suggested that the mode of action LEO-NEs against E. coli was to enhance bacterial chemotaxis and significantly inhibit ribosomal assembly. They may also affect butyric acid, ascorbic acid and aldehyde metabolism, and sulphur-relay system pathways. In conclusion, LEO-NEs had potential application as a natural antibacterial agent for the control of E. coli in the food industry.
关键词:
Soil organic matter;Spatial prediction;Digital soil mapping;Sampling density optimization;Random forest
摘要:
Purpose Spatial prediction of soil organic matter (SOM) in cultivated land is crucial for evaluating soil productivity and its role in terrestrial carbon cycling. Cultivated soils in mountainous regions are commonly scattered on the footslope whereas those in the plain regions are continuously planar distributed; hence, they are quite different in the degree of variation in soil-forming factors and thereby the soil properties including SOM. Materials and methods In this study, we used the digital soil mapping approach (DSM) to predict SOM (0-20 cm) in cultivated soils in a hill-mountain region, Longshan County (LS), and a plain-platform region, Nanxian County (NX), which are both located at the same latitude in Southern China. By using 6746 and 9571 soil sampling points for LS and NX, respectively, together with 33 environmental covariates, the optimal spatial interpolation models and the reasonable sample strategy were carefully discussed. Results and discussion Descriptive statistical results showed that SOM in LS and NX were both moderate variations (coefficient variation, 0.34) and were approximately normal distribution. SOM in NX was strongly spatially dependent while SOM in LS was a moderate spatial dependence. The conditional Latin hypercube sampling (cLHS) was more appropriate compared with the Simple Random Sampling (SRS) as the sampling strategy. The optimal model for predicting cultivated land SOM was the Random Forest (RF) model for both LS and NX. The prediction accuracy was positively correlated with the sampling density. Specifically, to obtain a high prediction accuracy, the reasonable sampling density for SOM in LS should be controlled at >= 4.0 per km(2), higher than that in NX (>= 2.0 per km(2)). Conclusions The combination of cLHS and the RF model probably is the best choice for cultivated land SOM spatial prediction in different terrains. Therefore, our results provide a basis for future DSM of SOM in similar regions and help optimize soil sampling density.
摘要:
The fall armyworm, known as Spodoptera frugiperda, is a notorious invasive pest wreaking havoc on agricultural crops globally. In the course of this study, a novel variant of the S. litura multiple nucleopolyhedrovirus (SpltMNPV-T0) was isolated from S. litura larvae found on tobacco plants in China. This research delved into the molecular and biological characteristics of SpltMNPV-T0. Electron microscopy revealed that this variant exhibited the characteristics features of a baculovirus. The complete genome of SpltMNPV-T0 was 137,925 bp in length, with a G + C content of 42.88 %, housing a total of 130 open reading frames (ORFs). Phylogenetically, this variant was similar to the published genome of the SpltMNPV-G2 strain, aligning itself with the Alphabaculovirus group II. However, it distinguished itself from the SpltMNPV-II in terms of sequence similarity (76.45 %), shared ORFs (only 63 genes in common), and gene order (exhibiting inversion and reordering). Crucially, SpltMNPV-T0 demonstrated notable effectiveness in controlling third-instar larvae of S. frugiperda and S. litura. Furthermore, the virulence of crude SpltMNPV-T0 matched that of the commercially available virus-based pesticide (SpltMNPV-KY), as evident in terms of mortality rates and speed of kill. These findings yield valu able insights into the molecular biology and functional genomics of this newly discovered variant, characterized by its high virulence. Such knowledge holds promise for advancing bio-control technologies aimed at mitigating the destructive impact of the pest S. frugiperda.