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1.
Sensors (Basel) ; 24(11)2024 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-38894276

RESUMEN

Malicious social bots pose a serious threat to social network security by spreading false information and guiding bad opinions in social networks. The singularity and scarcity of single organization data and the high cost of labeling social bots have given rise to the construction of federated models that combine federated learning with social bot detection. In this paper, we first combine the federated learning framework with the Relational Graph Convolutional Neural Network (RGCN) model to achieve federated social bot detection. A class-level cross entropy loss function is applied in the local model training to mitigate the effects of the class imbalance problem in local data. To address the data heterogeneity issue from multiple participants, we optimize the classical federated learning algorithm by applying knowledge distillation methods. Specifically, we adjust the client-side and server-side models separately: training a global generator to generate pseudo-samples based on the local data distribution knowledge to correct the optimization direction of client-side classification models, and integrating client-side classification models' knowledge on the server side to guide the training of the global classification model. We conduct extensive experiments on widely used datasets, and the results demonstrate the effectiveness of our approach in social bot detection in heterogeneous data scenarios. Compared to baseline methods, our approach achieves a nearly 3-10% improvement in detection accuracy when the data heterogeneity is larger. Additionally, our method achieves the specified accuracy with minimal communication rounds.

2.
Emerg Microbes Infect ; 13(1): 2341142, 2024 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38581279

RESUMEN

H6N6 avian influenza viruses (AIVs) have been widely detected in wild birds, poultry, and even mammals. Recently, H6N6 viruses were reported to be involved in the generation of H5 and H7 subtype viruses. To investigate the emergence, evolutionary pattern, and potential for an epidemic of H6N6 viruses, the complete genomes of 198 H6N6 viruses were analyzed, including 168 H6N6 viruses deposited in the NCBI and GISAID databases from inception to January 2019 and 30 isolates collected from China between November 2014 and January 2019. Using phylogenetic analysis, the 198 strains of H6N6 viruses were identified as 98 genotypes. Molecular clock analysis indicated that the evolution of H6N6 viruses in China was constant and not interrupted by selective pressure. Notably, the laboratory isolates reassorted with six subtype viruses: H6N2, H5N6, H7N9, H5N2, H4N2, and H6N8, resulting in nine novel H6N6 reassortment events. These results suggested that H6N6 viruses can act as an intermediary in the evolution of H5N6, H6N6, and H7N9 viruses. Animal experiments demonstrated that the 10 representative H6N6 viruses showed low pathogenicity in chickens and were capable of infecting mice without prior adaptation. Our findings suggest that H6N6 viruses play an important role in the evolution of AIVs, and it is necessary to continuously monitor and evaluate the potential epidemic of the H6N6 subtype viruses.


Asunto(s)
Pollos , Evolución Molecular , Genoma Viral , Virus de la Influenza A , Gripe Aviar , Filogenia , Virus Reordenados , Animales , China/epidemiología , Virus Reordenados/genética , Virus Reordenados/clasificación , Virus Reordenados/aislamiento & purificación , Gripe Aviar/virología , Gripe Aviar/epidemiología , Ratones , Pollos/virología , Virus de la Influenza A/genética , Virus de la Influenza A/clasificación , Virus de la Influenza A/aislamiento & purificación , Genotipo , Humanos
3.
Artículo en Inglés | MEDLINE | ID: mdl-38253396

RESUMEN

Amylosucrase (EC 2.4.1.4) is a versatile enzyme with significant potential in biotechnology and food production. To facilitate its efficient preparation, a novel expression strategy was implemented in Bacillus licheniformis for the secretory expression of Neisseria polysaccharea amylosucrase (NpAS). The host strain B. licheniformis CBBD302 underwent genetic modification through the deletion of sacB, a gene responsible for encoding levansucrase that synthesizes extracellular levan from sucrose, resulting in a levan-deficient strain, B. licheniformis CBBD302B. Neisseria polysaccharea amylosucrase was successfully expressed in B. licheniformis CBBD302B using the highly efficient Sec-type signal peptide SamyL, but its extracellular translocation was unsuccessful. Consequently, the expression of NpAS via the twin-arginine translocation (TAT) pathway was investigated using the signal peptide SglmU. The study revealed that NpAS could be effectively translocated extracellularly through the TAT pathway, with the signal peptide SglmU facilitating the process. Remarkably, 62.81% of the total expressed activity was detected in the medium. This study marks the first successful secretory expression of NpAS in Bacillus species host cells, establishing a foundation for its future efficient production. ONE-SENTENCE SUMMARY: Amylosucrase was secreted in Bacillus licheniformis via the twin-arginine translocation pathway.


Asunto(s)
Bacillus licheniformis , Glucosiltransferasas , Neisseria , Bacillus licheniformis/metabolismo , Señales de Clasificación de Proteína/genética , Fructanos , Arginina , Proteínas Bacterianas/genética
5.
Open Med (Wars) ; 18(1): 20230628, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36874361

RESUMEN

Long intergenic noncoding RNA 00511 (LINC00511) predicts poor prognosis in various malignancies and functions as an oncogene in distinct malignant tumors. The role of LINC00511 in melanoma progression was assessed. In our research, expression of LINC00511 in melanoma cells was detected by quantitative reverse transcription PCR. Colony formation and CCK8 assays were used to detect cell proliferation. Cell metastasis was evaluated by transwell and wound healing assays. Downstream target of LINC00511 was investigated by luciferase activity assay. As a results, LINC00511 was elevated in melanoma cells and tissues. Loss of LINC00511 decreased cell viability, reduced proliferation, invasion, and migration of melanoma. miR-610 was target of LINC00511, and miR-610 binds to 3'UTR of nucleobindin-2 (NUCB2). Inhibition of miR-610 attenuated LINC00511 deficiency-induced decrease of NUCB2 in melanoma cells. Loss of miR-610 weakened LINC00511 deficiency-induced decrease of cell viability, proliferation, invasion, and migration of melanoma. In conclusion, silence of LINC00511 reduced cell proliferation and metastasis of melanoma through down-regulation of miR-610-mediated NUCB2.

6.
Environ Pollut ; 320: 120962, 2023 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-36621716

RESUMEN

Improper discharge of slag from mining will pollute the surrounding soil, thereby affecting the ecology and becoming an important global problem. The available copper (ACu) content in polluted soil is an important factor affecting plant growth and development. When investigating a large area of soil with ACu, manual sampling by points and inspection are mainly used, due to the heterogeneity of soil, the efficiency and accuracy are lower. The Unmanned aerial vehicle (UAV) equipped with a hyperspectral sensor as a remote sensing technology is widely used in soil indicator monitoring because of its rapid and convenience. Meanwhile, using the relationship between soil organic matter and available copper has the potential to predict available copper. In this study, we selected the study area with tailings area in the Jianghan Plain of China and used a UAV equipped with a hyperspectral sensor to predict ACu and soil organic matter (SOM) in the soil with two datasets. Firstly, 74 soil samples were collected in the study area, and the ACu and SOM of the soil samples were determined. Second, a hyperspectral image of the study area is obtained using a UAV equipped with a hyperspectral sensor. Thirdly, we combine hyperspectral data with competitive adaptive reweighted sampling (CARS) to obtain feature bands and utilize simulated annealing deep neural network (SA-DNN) to generate estimation models. Finally, maps of the distribution of ACu and SOM in the area were generated using the model. In two datasets, the model of ACu with R2 values both are 0.89, and R2 on the model of SOM is 0.89 and 0.88. The results show that the combination of UAV hyperspectral imagery with the SA-DNN model has good performance in the prediction of organic matter and available copper, which is helpful for soil environmental monitoring.


Asunto(s)
Cobre , Suelo , Dispositivos Aéreos No Tripulados , Estanques , Redes Neurales de la Computación
7.
Comb Chem High Throughput Screen ; 26(5): 1001-1014, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-35713138

RESUMEN

OBJECTIVE: Malignant melanoma with gastric cancer is one of the most malignant tumors. However, there have been no reports on the effects of KAI1 and miRNA-633 on the survival and prognosis of patients with malignant melanoma with gastric cancer. METHODS: Fifty patients with malignant melanoma and gastric cancer were collected from October 2017 to December 2019. The clinical parameters included clinical information, such as sex, age, tumor size, and tumor staging. RT-qPCR was used to detect the expression of KAI1 and miRNA- 633. The role of KAI1 and miRNA-633 on the overall survival of melanoma was explored by the Pearson chi-square test, Spearman-rho correlation test, Univariate and multivariate cox regression analyses, and Kaplan-Meier method. Furthermore, the bioinformatic analysis was used to verify the role of KAI1 and miRNA-633 on malignant melanoma with gastric cancer. RESULTS: The expression of KAI1 and miRNA-633 was significantly related with the tumor size and staging of tumor (p<0.05) based on the Pearson chi-square test. Spearman's correlation coefficient displayed that KAI1 was significantly correlated with the miRNA-633 (ρ=-0.439, p=0.001). The result of multivariate cox proportional regression analysis showed that KAI1 (HR =0.109, 95% CI: 0.031-0.375, p< 0.001), and miRNA-633 (HR = 13.315, 95% CI: 3.844-46.119, p<0.001) were significantly associated with overall survival. CONCLUSION: The low expression level of KAI1 and high expression of miRNA-633 are significantly correlated with the poor overall survival prognosis of malignant melanoma with gastric cancer, to provide a basis for KAI1 and miRNA-633 to become novel molecular targets for malignant melanoma with gastric cancer.


Asunto(s)
Melanoma , MicroARNs , Neoplasias Gástricas , Humanos , Neoplasias Gástricas/diagnóstico , Neoplasias Gástricas/genética , MicroARNs/genética , Proteína Kangai-1/genética , Proteína Kangai-1/análisis , Proteína Kangai-1/metabolismo , Melanoma/diagnóstico , Melanoma/genética , Biomarcadores de Tumor/metabolismo , Estadificación de Neoplasias , Melanoma Cutáneo Maligno
8.
IEEE Trans Vis Comput Graph ; 29(1): 1016-1025, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36155436

RESUMEN

The IEEE VIS Conference (VIS) recently rebranded itself as a unified conference and officially positioned itself within the discipline of Data Science. Driven by this movement, we investigated (1) who contributed to VIS, and (2) where VIS stands in the scientific world. We examined the authors and fields of study of 3,240 VIS publications in the past 32 years based on data collected from OpenAlex and IEEE Xplore, among other sources. We also examined the citation flows from referenced papers (i.e., those referenced in VIS) to VIS, and from VIS to citing papers (i.e., those citing VIS). We found that VIS has been becoming increasingly popular and collaborative. The number of publications, of unique authors, and of participating countries have been steadily growing. Both cross-country collaborations, and collaborations between educational and non-educational affiliations, namely "cross-type collaborations", are increasing. The dominance of the US is decreasing, and authors from China are now an important part of VIS. In terms of author affiliation types, VIS is increasingly dominated by authors from universities. We found that the topics, inspirations, and influences of VIS research is limited such that (1) VIS, and their referenced and citing papers largely fall into the Computer Science domain, and (2) citations flow mostly between the same set of subfields within Computer Science. Our citation analyses showed that award-winning VIS papers had higher citations. Interactive visualizations, replication data, source code and supplementary material are available at https://32vis.hongtaoh.com and https://osf.io/zkvjm.

9.
Sci Rep ; 12(1): 21942, 2022 12 19.
Artículo en Inglés | MEDLINE | ID: mdl-36536070

RESUMEN

Pullulanase, a starch debranching enzyme, is required for the preparation of high glucose/maltose syrup from starch. In order to expand its narrow reaction conditions and improve its application value, Bacillus naganoensis pullulanase (PulA) was mutated by site-directed mutagenesis and the biochemical characteristics of the mutants were studied. The mutant PulA-N3 with mutations at asparagine 467, 492 and 709 residues was obtained. It displayed the activity maximum at 60 °C and pH 4.5 and exceeded 90% activities between 45 and 60 °C and from pH 4.0 to pH 5.5, which was improved greatly compared with wild-type PulA. Its thermostability and acidic pH stability were also remarkably improved. Its catalytic rate (kcat/Vmax) was 2.76 times that of PulA. In the preparation of high glucose syrup, the DX (glucose content, %) values of glucose mediated by PulA-N3 and glucoamylase reached 96.08%, which were 0.82% higher than that of PulA. In conclusion, a new pullulanase mutant PulA-N3 was successfully developed, which has high debranching activity in a wide range of temperature and pH, thereby paving the way for highly efficient starch saccharification.


Asunto(s)
Glicósido Hidrolasas , Almidón , Temperatura , Glicósido Hidrolasas/genética , Concentración de Iones de Hidrógeno
10.
Polymers (Basel) ; 14(22)2022 Nov 13.
Artículo en Inglés | MEDLINE | ID: mdl-36433022

RESUMEN

Novel poly(butylene succinate-butylene furandicarboxylate/polyethylene glycol succinate) (PBSF-PEG) was synthesized using two-step transesterification and polycondensation in the melt. There are characterized by intrinsic viscosity, GPC, 1H NMR, DSC, TGA, tensile, water absorption tests, and water degradation at different pH. GPC analysis showed that PBSF-PEG had high molecular weight with average molecular weight (Mw) up to 13.68 × 104 g/mol. Tensile tests showed that these polymers possessed good mechanical properties with a tensile strength as high as 30 MPa and elongation at break reaching 1500%. It should be noted that the increase of PEG units improved the toughness of the polyester material. In addition, the introduction of PEG promoted the water degradation properties of PBSF, and the copolymer showed a significantly faster water degradation rate when the PEG unit content was 20%. This suggests that the amount of PEG introduced could be applied to regulate the water degradation rate of the copolymers. Hence, these new polymers have great potential for application as environmentally friendly and sustainable plastic packaging materials.

11.
J Virol ; 96(18): e0123822, 2022 09 28.
Artículo en Inglés | MEDLINE | ID: mdl-36037479

RESUMEN

The H7N9 subtype influenza A viruses pose a serious threat to public health, and there is still a lack of vaccines or drugs for humans against H7N9 influenza viruses. In this study, we screened two monoclonal antibodies (MAbs), 4H1E8 and 7H9A6, that specifically recognize the hemagglutinin (HA) protein of H7N9 influenza virus and display highly neutralizing activity against H7N9 virus. The epitopes recognized by two MAbs are nearly all conserved within all known H7 subtypes. Characteristic identification showed that two MAbs have high avidity for the HA protein but no hemagglutinin inhibition activity or antibody-dependent cellular cytotoxicity. Mechanistically, the 4H1E8 and 7H9A6 antibodies inhibit the pH-dependent conformational change of HA and block the HA-mediated membrane fusion. More importantly, 4H1E8 and 7H9A6 exhibit promising prophylactic and therapeutic effects against lethal challenge with H7N9 virus. Moreover, 4H1E8- and 7H9A6-treated mice displayed inhibition of pulmonary viral replication and reduced lung lesions after viral challenge. Together, these findings indicate that antibodies 4H1E8 and 7H9A6 recognize unique epitopes in the HA protein and possess the neutralizing activity and protective efficacy against the H7N9 influenza A viruses. IMPORTANCE In 2013, H7N9 influenza viruses appeared in China and other countries resulting in more than 1,500 individual infections or death. There are still limited studies on vaccines or drugs for humans against H7N9 influenza viruses. Alternative approaches against H7N9 virus infection need to be developed. Here, we identified two monoclonal antibodies (4H1E8 and 7H9A6) that possess neutralizing activity by blocking the pH-dependent HA-mediated membrane fusion. Additionally, the two monoclonal antibodies protect mice against the H7N9 virus challenge prophylactically or therapeutically. Therefore, our study demonstrates that 4H1E8 and 7H9A6 could be used for the prevention and treatment of the H7N9 influenza virus, and the conserved epitopes we identified may contribute to the development of a broad H7N9 vaccine and provide insights into unique antiviral approaches.


Asunto(s)
Subtipo H7N9 del Virus de la Influenza A , Gripe Humana , Infecciones por Orthomyxoviridae , Animales , Anticuerpos Monoclonales/farmacología , Anticuerpos Monoclonales/uso terapéutico , Anticuerpos Antivirales , Antivirales/farmacología , Antivirales/uso terapéutico , Epítopos/metabolismo , Glicoproteínas Hemaglutininas del Virus de la Influenza/metabolismo , Humanos , Gripe Humana/tratamiento farmacológico , Ratones , Ratones Endogámicos BALB C , Infecciones por Orthomyxoviridae/tratamiento farmacológico , Replicación Viral/efectos de los fármacos
12.
J Int Med Res ; 50(8): 3000605221116758, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-35942551

RESUMEN

OBJECTIVE: This study aimed to investigate the correlation between KAI1 (CD82) and miR-633 expression and prognosis and survival time of patients with melanoma combined with colorectal cancer (CRC). METHODS: Clinical and follow-up data of melanoma and CRC patients were recorded, and the expression levels of KAI1 and miR-633 were detected. Pearson chi-square tests and Spearman correlation coefficient were used to analyze the relationship between prognosis and related parameters in these patients. Cox proportional risk regression and receiver operating characteristic curve analyses were used. RESULTS: Overall, 195 patients were included. KAI1 and miR-633 expression levels were significantly correlated with the prognosis of patients with melanoma combined with CRC. Spearman correlation analysis showed that the expression levels of KAI1 and miR-633 were significantly correlated with the prognosis of patients. Multivariate Cox regression analysis suggested that low expression levels of KAI1 and high expression levels of miR-633 indicated shorter survival time for patients. CONCLUSIONS: KAI1 expression was significantly correlated with melanoma and CRC patient prognosis. When KAI1 expression levels were low, the patient survival time was poor.


Asunto(s)
Neoplasias Colorrectales , Proteína Kangai-1/metabolismo , Melanoma , MicroARNs , Biomarcadores de Tumor/metabolismo , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/patología , Humanos , Proteína Kangai-1/análisis , Proteína Kangai-1/genética , Melanoma/genética , Melanoma/patología , MicroARNs/genética , Estadificación de Neoplasias , Pronóstico
13.
J Ind Microbiol Biotechnol ; 49(3)2022 May 25.
Artículo en Inglés | MEDLINE | ID: mdl-35325171

RESUMEN

Bacillus licheniformis is a well-known platform strain for production of industrial enzymes. However, the development of genetically stable recombinant B. licheniformis for high-yield enzyme production is still laborious. Here, a pair of plasmids, pUB-MazF and pUB'-EX1, were firstly constructed. pUB-MazF is a thermosensitive, self-replicable plasmid. It was able to efficiently cure from the host cell through induced expression of an endoribonuclease MazF, which is lethal to the host cell. pUB'-EX1 is a nonreplicative and integrative plasmid. Its replication was dependent on the thermosensitive replicase produced by pUB-MazF. Transformation of pUB'-EX1 into the B. licheniformis BL-UBM harboring pUB-MazF resulted in both plasmids coexisting in the host cell. At an elevated temperature, and in the presence of isopropyl-1-thio-ß-d-galactopyranoside and kanamycin, curing of the pUB-MazF and multiple-copy integration of pUB'-EX1 occurred, simultaneously. Through this procedure, genetically stable recombinants integrated multiple copies of amyS, from Geobacillus stearothermophilus ATCC 31195 were facilely obtained. The genetic stability of the recombinants was verified by repeated subculturing and shaking flask fermentations. The production of α-amylase by recombinant BLiS-002, harboring five copies of amyS, in a 50-l bioreactor reached 50 753 U/ml after 72 hr fermentation. This strategy therefore has potential for production of other enzymes in B. licheniformis and for genetic modification of other Bacillus species.


Asunto(s)
Bacillus licheniformis , Bacillus , Amilasas , Bacillus/genética , Bacillus licheniformis/genética , Bacillus licheniformis/metabolismo , Plásmidos/genética , alfa-Amilasas/genética , alfa-Amilasas/metabolismo
14.
PLoS Pathog ; 18(2): e1010299, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-35171955

RESUMEN

Influenza A viruses (IAVs) continuously challenge the poultry industry and human health. Elucidation of the host factors that modulate the IAV lifecycle is vital for developing antiviral drugs and vaccines. In this study, we infected A549 cells with IAVs and found that host protein contactin-1 (CNTN1), a member of the immunoglobulin superfamily, enhanced viral replication. Bioinformatic prediction and experimental validation indicated that the expression of CNTN1 was reduced by microRNA-200c (miR-200c) through directly targeting. We further showed that CNTN1-modulated viral replication in A549 cells is dependent on type I interferon signaling. Co-immunoprecipitation experiments revealed that CNTN1 specifically interacts with MAVS and promotes its proteasomal degradation by removing its K63-linked ubiquitination. Moreover, we discovered that the deubiquitinase USP25 is recruited by CNTN1 to catalyze the deubiquitination of K63-linked MAVS. Consequently, the CNTN1-induced degradation cascade of MAVS blocked RIG-I-MAVS-mediated interferon signaling, leading to enhanced viral replication. Taken together, our data reveal novel roles of CNTN1 in the type I interferon pathway and regulatory mechanism of IAV replication.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/metabolismo , Contactina 1/metabolismo , Proteína 58 DEAD Box/metabolismo , Virus de la Influenza A/metabolismo , Gripe Humana/virología , MicroARNs/metabolismo , Receptores Inmunológicos/metabolismo , Ubiquitina Tiolesterasa/metabolismo , Células A549 , Interacciones Microbiota-Huesped , Humanos , Interferón Tipo I/metabolismo , Transducción de Señal , Ubiquitinación , Replicación Viral
15.
Vaccine ; 40(6): 886-896, 2022 02 07.
Artículo en Inglés | MEDLINE | ID: mdl-34991927

RESUMEN

Live and killed vaccines impart a significant role in preventing of Newcastle disease (ND) in China. Vaccine efficacy could be ameliorated by improving vaccine-induced cellular immunity and antibody persistency. Previous studies substantiated the potency of silicon dioxide (SiO2) in the control-release of drugs and as a vaccine adjuvant, and polyethylenimine (PEI) merits as a mucosal adjuvanticity with electro-positivity. The present study employed SiO2 and PEI to prepare biomimetic silicon mineralized nanoparticle G7M@SiO2-PEI and microparticle (SiO2 + PEI)@G7M vaccines of G7M, a candidate for live attenuated vaccine of genotype VII Newcastle disease virus (NDV). The zeta potential experiment confirmed the significant increase in the average zeta potential of the nanoparticle G7M@SiO2-PEI and microparticle (SiO2 + PEI)@G7M relative to G7M before mineralization. The results of RT-qPCR revealed more than 99% mineralization efficiency of the G7M@SiO2-PEI and (SiO2 + PEI)@G7M. The morphology detected by transmission electron microscopy reported that the diameters of G7M@SiO2-PEI were similar to those of G7M, while for (SiO2 + PEI)@G7M, it was about five times larger than that of G7M. Silicon was detected on the surface of both mineralization particles, except for G7M, as observed from the elemental distribution detected by elemental mapping and energy dispersive X-ray spectrogram. Indirect immunofluorescence assays validated that mineralization virus have replicated ability in BHK-21F cells. In vivo experiments revealed higher than 5.50 log2 of antibody in nanoparticles G7M@SiO2-PEI group until 10-week post-vaccination, and significant proliferation of antigen-specific CD3+CD4+ in nanoparticles G7M@SiO2-PEI immunized group corroborated improved cellular immune responses. Vaccines provided full protection to the immunized chickens, whereas all the chickens receiving mock immunizations succumbed to the disease. Overall, our study concluded the efficacy of biomimetic mineralization of live attenuated vaccine in nanoparticles to improve humoral and cellular immune responses.


Asunto(s)
Enfermedad de Newcastle , Enfermedades de las Aves de Corral , Vacunas Virales , Animales , Anticuerpos Antivirales , Biomimética , Pollos , Virus de la Enfermedad de Newcastle , Polietileneimina , Enfermedades de las Aves de Corral/prevención & control , Dióxido de Silicio , Vacunas Atenuadas
16.
Plant Divers ; 43(4): 264-274, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-34485768

RESUMEN

Topography and soil factors are known to play crucial roles in the species composition of plant communities in subtropical evergreen-deciduous broadleaved mixed forests. In this study, we used a systematic quantitative approach to classify plant community types in the subtropical forests of Hubei Province (central China), and then quantified the relative contribution of drivers responsible for variation in species composition and diversity. We classified the subtropical forests in the study area into 12 community types. Of these, species diversity indices of three communities were significantly higher than those of others. In each community type, species richness, abundance, basal area and importance values of evergreen and deciduous species were different. In most community types, deciduous species richness was higher than that of evergreen species. Linear regression analysis showed that the dominant factors that affect species composition in each community type are elevation, slope, aspect, soil nitrogen content, and soil phosphorus content. Furthermore, structural equation modeling analysis showed that the majority of variance in species composition of plant communities can be explained by elevation, aspect, soil water content, litterfall, total nitrogen, and total phosphorus. Thus, the major factors that affect evergreen and deciduous species distribution across the 12 community types in subtropical evergreen-deciduous broadleaved mixed forests include elevation, slope and aspect, soil total nitrogen content, soil total phosphorus content, soil available nitrogen content and soil available phosphorus content.

17.
J Ind Microbiol Biotechnol ; 48(5-6)2021 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-34124759

RESUMEN

Ammonium hydroxide is conventionally used as an alkaline reagent and cost-effective nitrogen source in enzyme manufacturing processes. However, few ammonia-inducible enzyme expression systems have been described thus far. In this study, genomic-wide transcriptional changes in Bacillus licheniformis CBBD302 cultivated in media supplemented with ammonia were analyzed, resulting in identification of 1443 differently expressed genes, of which 859 genes were upregulated and 584 downregulated. Subsequently, the nucleotide sequences of ammonia-inducible promoters were analyzed and their functionally-mediated expression of amyL, encoding an α-amylase, was shown. TRNA_RS39005 (copA), TRNA_RS41250 (sacA), TRNA_RS23130 (pdpX), TRNA_RS42535 (ald), TRNA_RS31535 (plp), and TRNA_RS23240 (dfp) were selected out of the 859 upregulated genes and each showed higher transcription levels (FPKM values) in the presence of ammonia and glucose than that of the control. The promoters, PcopA from copA, PsacA from sacA, PpdpX from pdpX, Pald from ald, and Pplp from plp, except Pdfp from dfp, were able to mediate amyL expression and were significantly induced by ammonia. The highest enzyme expression level was mediated by Pplp and represented 23% more α-amylase activity after induction by ammonia in a 5-L fermenter. In conclusion, B. licheniformis possesses glucose-independent ammonia-inducible promoters, which can be used to mediate enzyme expression and therefore enhance the enzyme yield in fermentations conventionally fed with ammonia for pH adjustment and nitrogen supply.


Asunto(s)
Amoníaco/metabolismo , Bacillus licheniformis/metabolismo , Regiones Promotoras Genéticas , alfa-Amilasas/metabolismo , Bacillus licheniformis/genética , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Secuencia de Bases , ADN Bacteriano , Fermentación , Perfilación de la Expresión Génica , Regulación Bacteriana de la Expresión Génica , Concentración de Iones de Hidrógeno , Microbiología Industrial , Nitrógeno/metabolismo , Estrés Fisiológico , alfa-Amilasas/genética
18.
PLoS Pathog ; 17(2): e1009300, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-33577621

RESUMEN

Influenza A virus (IAV) has evolved various strategies to counteract the innate immune response using different viral proteins. However, the mechanism is not fully elucidated. In this study, we identified the PB1 protein of H7N9 virus as a new negative regulator of virus- or poly(I:C)-stimulated IFN induction and specifically interacted with and destabilized MAVS. A subsequent study revealed that PB1 promoted E3 ligase RNF5 to catalyze K27-linked polyubiquitination of MAVS at Lys362 and Lys461. Moreover, we found that PB1 preferentially associated with a selective autophagic receptor neighbor of BRCA1 (NBR1) that recognizes ubiquitinated MAVS and delivers it to autophagosomes for degradation. The degradation cascade mediated by PB1 facilitates H7N9 virus infection by blocking the RIG-I-MAVS-mediated innate signaling pathway. Taken together, these data uncover a negative regulatory mechanism involving the PB1-RNF5-MAVS-NBR1 axis and provide insights into an evasion strategy employed by influenza virus that involves selective autophagy and innate signaling pathways.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/metabolismo , Autofagia , Proteínas de Unión al ADN/metabolismo , Inmunidad Innata/inmunología , Gripe Humana/inmunología , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo , Proteínas Virales/metabolismo , Proteínas Adaptadoras Transductoras de Señales/genética , Proteínas de Unión al ADN/genética , Células HEK293 , Humanos , Subtipo H7N9 del Virus de la Influenza A/fisiología , Gripe Humana/metabolismo , Gripe Humana/patología , Gripe Humana/virología , Péptidos y Proteínas de Señalización Intracelular/genética , Mitocondrias/metabolismo , Transducción de Señal , Ubiquitina/metabolismo , Ubiquitina-Proteína Ligasas/genética , Ubiquitinación , Proteínas Virales/genética , Replicación Viral
19.
Environ Pollut ; 273: 116521, 2021 Jan 18.
Artículo en Inglés | MEDLINE | ID: mdl-33508627

RESUMEN

Approximately 1/3 of vegetables in China are produced in solar greenhouses. Most farmers use conventional irrigation with over fertilisation (CIF), thereby applying approximately 2000 kg N ha-1 fertiliser over two cropping seasons per year. Here, we tested the effect of drip irrigation with reduced fertilisation (DIF) combined with straw incorporation on reducing N2O emissions and nitrogen leaching from solar greenhouse vegetable production systems. Over three consecutive tomato cropping seasons, N2O emissions and nitrogen leaching were monitored in high temporal resolution, thereby producing a unique dataset. Compared to CIF, the realised drip fertigation scheme reduces N2O emission and nitrogen leaching of nitrate and dissolved organic nitrogen by approximately a factor of 5-10 (N2O-DIF: 10.3, CIF: 47.5 kg N ha-1 yr-1; N leaching-DIF: 83.6, CIF: 863 kg N ha-1 yr-1). Straw incorporation in CIF, though advantageous for soil health, resulted in pollution swapping as soil N2O emissions increased while NO3- leaching losses decreased. On the contrary, no significant negative environmental N effects of straw incorporation were found for DIF. As crop productivity was not affected by straw incorporation, neither for CIF nor for DIF, our study provides a sound basis for policy advice to recommend farmers to adopt drip fertigation combined with straw application. Wide scale adoption of this technique will result in reductions of environment N losses, alleviate major soil degradation signs, including soil acidity, nutrient imbalance and deterioration of soil microbial community structure, while allowing to maintaining high yields of vegetables in solar greenhouse production systems.

20.
Oncol Lett ; 21(2): 88, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33376521

RESUMEN

The aim of the present study was to determine the impact of microRNA (miRNA/miR)-633 on the biological properties of malignant melanoma cells. Kang-Ai 1 (KAI1), also known as cluster of differentiation 82, is an important transcriptional regulator and tumor suppressor gene present in different types of tumors. miRNAs that potentially bind with KAI1 were predicted via bioinformatics analyses. In total, six putative miRNA regulators of KAI1 were identified in the present analysis, among which miR-633 was upregulated the most in melanoma tissues compared with the control group. The expression levels of miR-633 and KAI1 in melanoma tissues compared with adjacent normal tissues were then assessed. It was found that miR-633 was significantly upregulated in melanoma cells compared with the control group, whereas the expression levels of KAI1 showed the opposite results. miR-633 was predicted to target the 3'-untranslated region of KAI1 using predictive online tools, and results from luciferase reporter assays confirmed the direct regulation of KAI1 promoter activity by miR-633. Furthermore, miR-633 mimics over expression was shown to suppress both mRNA and protein expression of KAI1, while miR-633 inhibition resulted in decreased viability and migrationin melanoma cells in vitro. Taken together, the present study demonstrated, to the best of the authors' knowledge for the first time, that miR-633 exerts an important role in melanoma through targeting KAI1.

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