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1.
Plant Physiol ; 196(3): 1908-1922, 2024 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-39186538

RESUMO

The fascinating scent of rose (Rosa genus) flowers has captivated human senses for centuries, making them one of the most popular and widely used floral fragrances. Despite much progress over the last decade, many biochemical pathways responsible for rose scents remain unclear. We analyzed the floral scent compositions from various rose varieties and selected the modern cultivar Rosa hybrida "Double Delight" as a model system to unravel the formation of rose dominant volatile terpenes, which contribute substantially to the rose fragrance. Key genes involved in rose terpene biosynthesis were functionally characterized. Cytosolic geranyl diphosphate (GPP) generated by geranyl/farnesyl diphosphate synthase (G/FPPS1) catalysis played a pivotal role in rose scent production, and terpene synthases in roses play an important role in the formation of most volatile terpenes, but not for geraniol, citral, or ß-citronellol. Subsequently, a series of enzymes, including geraniol dehydrogenase, geranial reductase, 12-oxophytodienoate reductase, and citronellal reductase, were characterized as involved in the transformation of geraniol to ß-citronellol in roses through three successive steps. Interestingly, the ß-citronellol biosynthesis pathway appears to be conserved in other horticultural plants like Lagerstroemia caudata and Paeonia lactiflora. Our findings provide valuable insights into the biosynthesis of rose volatile terpenoid compounds and offer essential gene resources for future breeding and molecular modification efforts.


Assuntos
Monoterpenos Acíclicos , Rosa , Terpenos , Compostos Orgânicos Voláteis , Rosa/metabolismo , Rosa/genética , Monoterpenos Acíclicos/metabolismo , Terpenos/metabolismo , Compostos Orgânicos Voláteis/metabolismo , Monoterpenos/metabolismo , Flores/metabolismo , Flores/genética , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Alquil e Aril Transferases/metabolismo , Alquil e Aril Transferases/genética , Odorantes/análise , Regulação da Expressão Gênica de Plantas , Genes de Plantas
2.
Bull Environ Contam Toxicol ; 110(4): 71, 2023 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-36991215

RESUMO

Titanium dioxide nanoparticles (TiO2 NPs) are ubiquitous in the environment and enter the terrestrial food chain via plant uptake. However, plant uptake behaviors of TiO2 NPs remain elusive. Here, the uptake kinetics of TiO2 NPs by wheat (Triticum aestivum L.) seedlings and the effects on cation flux in roots were examined in a hydroponic system. Uptake rate of TiO2 NPs ranged from 119.0 to 604.2 mg kg- 1 h- 1 within 8 h exposure. NP uptake decreased by 83% and 47%, respectively, in the presence of sodium azide (NaN3) and carbonyl cyanide m-chlorophenylhydrazone (CCCP), indicating an energy-dependent uptake of TiO2 NPs. Moreover, accompanied with TiO2 NP uptake, net influx of Cd2+ decreased by 81%, while Na+ flux shifted from inflow to outflow at the meristematic zone of root. These findings provide valuable information for understanding plant uptake of TiO2 NPs.


Assuntos
Nanopartículas , Plântula , Triticum , Titânio , Cátions
3.
Bull Environ Contam Toxicol ; 109(3): 470-476, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35441855

RESUMO

The buildup of silver nanoparticles (AgNPs) in soil has raised mounting concerns on their impact on human health. Human are exposed to AgNPs in soils via hand-to-mouth activities (direct exposure) and food consumption (indirect exposure). However, the bioaccessibility of AgNPs under these exposure scenarios remains largely unknown. We used a physiologically based extraction test (PBET) to assess Ag bioaccessibility in AgNP-containing soils and in earthworms (Pheretima guillemi) cultured in these soils. Silver bioaccessibility was 1.2 - 8.4% and 8.1 - 78.7% upon direct exposure and indirect exposure, respectively. These results indicated greater Ag bioaccessibility in earthworms than in soils. Moreover, particle size decreased upon direct exposure, but remained constant upon indirect exposure in wetland soil, as revealed by single particle inductively coupled plasma-mass spectrometry (spICP-MS) analysis. Our results highlight the importance of indirect exposure to NPs.


Assuntos
Nanopartículas Metálicas , Oligoquetos , Poluentes do Solo , Animais , Humanos , Nanopartículas Metálicas/química , Prata/química , Solo/química , Poluentes do Solo/análise
4.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 39(2): 301-310, 2022 Apr 25.
Artigo em Zh | MEDLINE | ID: mdl-35523551

RESUMO

Electrocardiogram (ECG) can visually reflect the physiological electrical activity of human heart, which is important in the field of arrhythmia detection and classification. To address the negative effect of label imbalance in ECG data on arrhythmia classification, this paper proposes a nested long short-term memory network (NLSTM) model for unbalanced ECG signal classification. The NLSTM is built to learn and memorize the temporal characteristics in complex signals, and the focal loss function is used to reduce the weights of easily identifiable samples. Then the residual attention mechanism is used to modify the assigned weights according to the importance of sample characteristic to solve the sample imbalance problem. Then the synthetic minority over-sampling technique is used to perform a simple manual oversampling process on the Massachusetts institute of technology and Beth Israel hospital arrhythmia (MIT-BIH-AR) database to further increase the classification accuracy of the model. Finally, the MIT-BIH arrhythmia database is applied to experimentally verify the above algorithms. The experimental results show that the proposed method can effectively solve the issues of imbalanced samples and unremarkable features in ECG signals, and the overall accuracy of the model reaches 98.34%. It also significantly improves the recognition and classification of minority samples and has provided a new feasible method for ECG-assisted diagnosis, which has practical application significance.


Assuntos
Memória de Curto Prazo , Redes Neurais de Computação , Algoritmos , Arritmias Cardíacas/diagnóstico , Eletrocardiografia , Humanos , Processamento de Sinais Assistido por Computador
5.
BMC Genomics ; 22(1): 885, 2021 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-34886808

RESUMO

BACKGROUND: Rose is one of the most popular flowers in the wold. Its field growth and quality are negatively affected by aphids. However, the defence mechanisms used by rose plants against aphids are unclear. Therefore, to understand the defence mechanism of rose under aphid stress, transcriptome and metabolome techniques were used to investigate the regulation mechanism in R. longicuspis infected with M. rosivorum. RESULT: In our study, after inoculation with M. rosivorum, M. rosivorum quickly colonized R. longicuspis. A total of 34,202 genes and 758 metabolites were detected in all samples. Under M. rosivorum stress, R. longicuspis responded by MAPK cascades, plant hormone signal transduction pathway activation, RlMYBs and RlERFs transcription factors expression and ROS production. Interestingly, the 'brassinosteroid biosynthesis' pathway was significantly enriched in A3 d-vs.-A5 d. Further analysis showed that M. rosivorum induced the biosynthesis of secondary metabolites such as terpenoids, tannins and phenolic acids, among others. Importantly, the 'glutathione metabolic' and 'glucosinolate biosynthesis' pathways were significantly enriched, which involved in the rose against aphids. CONCLUSION: Our study provides candidate genes and metabolites for Rosa defence against aphids. This study provides a theoretical basis for further exploring the molecular regulation mechanism of rose aphid resistance and aphid resistance breeding in the future.


Assuntos
Afídeos , Rosa , Animais , Afídeos/genética , Regulação da Expressão Gênica de Plantas , Reguladores de Crescimento de Plantas , Rosa/genética , Transcriptoma
6.
J Gene Med ; 23(2): e3297, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33217097

RESUMO

BACKGROUND: The antibody-dependent enhancement (ADE) of dengue virus (DENV) has critically restricted vaccine development. Prior research suggested pr4 as the probable ADE epitope of DENV. METHODS: Chimeric DENV was constructed by replacing the DENV pr4 gene with the corresponding Japanese encephalitis virus (JEV) gene to determine whether it can reduce ADE activities. An alanine scanning method and bioinformatics analysis were utilized to identify the amino acid of pr4 that was crucial as an ADE epitope. RESULTS: Chimeric virus reduced ADE and virulence. The amino acids at the following locations on the mutant peptides showed significantly reduced binding ability to prM antibody: pr4.5 (position 5 - leucine), pr4.6 (position 6 - leucine), pr4.7 (position 7 - phenyalanine) and pr4.16 (position 16 - cysteine). The four amino acids had formed a pocket-like structure, which could increase the possibility of binding to an antibody. CONCLUSIONS: ADE activities could be reduced by replacing the DENV pr4 gene with the corresponding JEV gene. Leucine at position 5, leucine at position 6, phenyalanine at position 7 and cysteine at position 16 were the key amino acid sites in the ADE response of DENV. The occurrence of ADE can potentially be reduced by the replacement of key amino acids, hence highlighting its possible contribution to dengue vaccine design, paving a way for future vaccine research.


Assuntos
Anticorpos Facilitadores , Vírus da Dengue/genética , Vírus da Dengue/imunologia , Dengue/imunologia , Proteínas do Envelope Viral/genética , Proteínas do Envelope Viral/imunologia , Vacinas Virais/imunologia , Aminoácidos/química , Animais , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Linhagem Celular , Quimera/genética , Quimera/imunologia , Dengue/virologia , Vírus da Encefalite Japonesa (Espécie)/genética , Vírus da Encefalite Japonesa (Espécie)/imunologia , Humanos , Células K562 , Modelos Moleculares , Mutação , Estrutura Terciária de Proteína , Desenvolvimento de Vacinas
7.
BMC Plant Biol ; 21(1): 223, 2021 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-34001006

RESUMO

BACKGROUND: Rose is an important economic crop in horticulture. However, its field growth and postharvest quality are negatively affected by grey mould disease caused by Botrytis c. However, it is unclear how rose plants defend themselves against this fungal pathogen. Here, we used transcriptomic, metabolomic and VIGS analyses to explore the mechanism of resistance to Botrytis c. RESULT: In this study, a protein activity analysis revealed a significant increase in defence enzyme activities in infected plants. RNA-Seq of plants infected for 0 h, 36 h, 60 h and 72 h produced a total of 54 GB of clean reads. Among these reads, 3990, 5995 and 8683 differentially expressed genes (DEGs) were found in CK vs. T36, CK vs. T60 and CK vs. T72, respectively. Gene annotation and cluster analysis of the DEGs revealed a variety of defence responses to Botrytis c. infection, including resistance (R) proteins, MAPK cascade reactions, plant hormone signal transduction pathways, plant-pathogen interaction pathways, Ca2+ and disease resistance-related genes. qPCR verification showed the reliability of the transcriptome data. The PTRV2-RcTGA1-infected plant material showed improved susceptibility of rose to Botrytis c. A total of 635 metabolites were detected in all samples, which could be divided into 29 groups. Metabonomic data showed that a total of 59, 78 and 74 DEMs were obtained for T36, T60 and T72 (T36: Botrytis c. inoculated rose flowers at 36 h; T60: Botrytis c. inoculated rose flowers at 60 h; T72: Botrytis c. inoculated rose flowers at 72 h) compared to CK, respectively. A variety of secondary metabolites are related to biological disease resistance, including tannins, amino acids and derivatives, and alkaloids, among others; they were significantly increased and enriched in phenylpropanoid biosynthesis, glucosinolates and other disease resistance pathways. This study provides a theoretical basis for breeding new cultivars that are resistant to Botrytis c. CONCLUSION: Fifty-four GB of clean reads were generated through RNA-Seq. R proteins, ROS signalling, Ca2+ signalling, MAPK signalling, and SA signalling were activated in the Old Blush response to Botrytis c. RcTGA1 positively regulates rose resistance to Botrytis c. A total of 635 metabolites were detected in all samples. DEMs were enriched in phenylpropanoid biosynthesis, glucosinolates and other disease resistance pathways.


Assuntos
Botrytis/patogenicidade , Resistência à Doença/genética , Glucosinolatos/biossíntese , Glucosinolatos/genética , Imunidade Vegetal/genética , Rosa/genética , Rosa/microbiologia , China , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Horticultura , Interações Hospedeiro-Patógeno/genética , Metaboloma , Reprodutibilidade dos Testes , Transcriptoma
8.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 38(5): 848-857, 2021 Oct 25.
Artigo em Zh | MEDLINE | ID: mdl-34713652

RESUMO

The automatic detection of arrhythmia is of great significance for the early prevention and diagnosis of cardiovascular diseases. Traditional arrhythmia diagnosis is limited by expert knowledge and complex algorithms, and lacks multi-dimensional feature representation capabilities, which is not suitable for wearable electrocardiogram (ECG) monitoring equipment. This study proposed a feature extraction method based on autoregressive moving average (ARMA) model fitting. Different types of heartbeats were used as model inputs, and the characteristic of fast and smooth signal was used to select the appropriate order for the arrhythmia signal to perform coefficient fitting, and complete the ECG feature extraction. The feature vectors were input to the support vector machine (SVM) classifier and K-nearest neighbor classifier (KNN) for automatic ECG classification. MIT-BIH arrhythmia database and MIT-BIH atrial fibrillation database were used to verify in the experiment. The experimental results showed that the feature engineering composed of the fitting coefficients of the ARMA model combined with the SVM classifier obtained a recall rate of 98.2% and a precision rate of 98.4%, and the F 1 index was 98.3%. The algorithm has high performance, meets the needs of clinical diagnosis, and has low algorithm complexity. It can use low-power embedded processors for real-time calculations, and it's suitable for real-time warning of wearable ECG monitoring equipment.


Assuntos
Fibrilação Atrial , Eletrocardiografia , Algoritmos , Frequência Cardíaca , Humanos , Processamento de Sinais Assistido por Computador , Máquina de Vetores de Suporte
9.
Molecules ; 23(2)2018 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-29439505

RESUMO

Rosa chinensis var. spontanea, an endemic and endangered plant of China, is one of the key ancestors of modern roses and a source for famous traditional Chinese medicines against female diseases, such as irregular menses and dysmenorrhea. In this study, the complete chloroplast (cp) genome of R. chinensis var. spontanea was sequenced, analyzed, and compared to congeneric species. The cp genome of R. chinensis var. spontanea is a typical quadripartite circular molecule of 156,590 bp in length, including one large single copy (LSC) region of 85,910 bp and one small single copy (SSC) region of 18,762 bp, separated by two inverted repeat (IR) regions of 25,959 bp. The GC content of the whole genome is 37.2%, while that of LSC, SSC, and IR is 42.8%, 35.2% and 31.2%, respectively. The genome encodes 129 genes, including 84 protein-coding genes (PCGs), 37 transfer RNA (tRNA) genes, and eight ribosomal RNA (rRNA) genes. Seventeen genes in the IR regions were found to be duplicated. Thirty-three forward and five inverted repeats were detected in the cp genome of R. chinensis var. spontanea. The genome is rich in SSRs. In total, 85 SSRs were detected. A genome comparison revealed that IR contraction might be the reason for the relatively smaller cp genome size of R. chinensis var. spontanea compared to other congeneric species. Sequence analysis revealed that the LSC and SSC regions were more divergent than the IR regions within the genus Rosa and that a higher divergence occurred in non-coding regions than in coding regions. A phylogenetic analysis showed that the sampled species of the genus Rosa formed a monophyletic clade and that R. chinensis var. spontanea shared a more recent ancestor with R. lichiangensis of the section Synstylae than with R. odorata var. gigantea of the section Chinenses. This information will be useful for the conservation genetics of R. chinensis var. spontanea and for the phylogenetic study of the genus Rosa, and it might also facilitate the genetics and breeding of modern roses.


Assuntos
Cloroplastos/genética , Genes de Plantas , Genoma de Cloroplastos , Filogenia , Rosa/genética , Composição de Bases , Evolução Biológica , China , Duplicação Gênica , Ontologia Genética , Tamanho do Genoma , Sequências Repetidas Invertidas , Anotação de Sequência Molecular , Fases de Leitura Aberta , Rosa/classificação , Análise de Sequência de DNA
10.
J Integr Plant Biol ; 60(1): 34-44, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28895654

RESUMO

Rose has emerged as a model ornamental plant for studies of flower development, senescence, and morphology, as well as the metabolism of floral fragrances and colors. Virus-induced gene silencing (VIGS) has long been used in functional genomics studies of rose by vacuum infiltration of cuttings or seedlings with an Agrobacterium suspension carrying TRV-derived vectors. However, VIGS in rose flowers remains a challenge because of its low efficiency and long time to establish silencing. Here we present a novel and rapid VIGS method that can be used to analyze gene function in rose, called 'graft-accelerated VIGS', where axillary sprouts are cut from the rose plant and vacuum infiltrated with Agrobacterium. The inoculated scions are then grafted back onto the plants to flower and silencing phenotypes can be observed within 5 weeks, post-infiltration. Using this new method, we successfully silenced expression of the RhDFR1, RhAG, and RhNUDX1 in rose flowers, and affected their color, petal number, as well as fragrance, respectively. This grafting method will facilitate high-throughput functional analysis of genes in rose flowers. Importantly, it may also be applied to other woody species that are not currently amenable to VIGS by conventional leaf or plantlet/seedling infiltration methods.


Assuntos
Flores/genética , Inativação Gênica , Genômica , Vírus de Plantas/fisiologia , Rosa/genética , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Plantas Geneticamente Modificadas
11.
Microb Pathog ; 111: 402-409, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28826765

RESUMO

Since 2013, a novel Influenza A (H7N9) virus strain has continued to circulate within poultry and causing human disease. Influenza A (H7N9) virus results in two types of infection: mild and severe. The different results of clinical findings may be related with host susceptibility and characteristics of the virus itself. In order to investigate potential pathogenesis of Influenza A (H7N9) virus, we performed pathogenecity and cytokines analysis of two isolates, A/Guangdong/6/2013 H7N9 virus (GD-6) from a patient with a mild infection, and A/Guangdong/7/2013 H7N9 virus (GD-7) from a patient with a fatal infection. We found that GD-7 replicated to higher levels than GD-6 in human peripheral blood mononuclear cells (PBMCs), lung tissues, and mice. Furthermore, GD-7 infection resulted in more severe lung damage in mice lung tissues than GD-6 infection. GD-7 elicited higher levels of interleukin-6 (IL-6) and tumor necrosis factor-α(TNF-α) than GD-6 did. In conclusion, GD-7 was more pathogenic and induced higher levels of proinflammatory cytokines than GD-6 did.


Assuntos
Subtipo H7N9 do Vírus da Influenza A/patogenicidade , Influenza Humana/virologia , Interleucina-6/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Animais , Citocinas/genética , Citocinas/metabolismo , Feminino , Humanos , Subtipo H7N9 do Vírus da Influenza A/genética , Subtipo H7N9 do Vírus da Influenza A/isolamento & purificação , Subtipo H7N9 do Vírus da Influenza A/fisiologia , Influenza Humana/metabolismo , Influenza Humana/mortalidade , Influenza Humana/patologia , Interleucina-6/genética , Pulmão/metabolismo , Pulmão/patologia , Pulmão/virologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Mutação , Fator de Necrose Tumoral alfa/genética , Virulência , Replicação Viral
12.
Appl Microbiol Biotechnol ; 99(22): 9685-98, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26219500

RESUMO

Severe dengue is more likely found during secondary heterologous dengue virus (DENV) infection or primary infection of infants born to dengue-immune mothers and led to the hypothesis of antibody-dependent enhancement (ADE). It has been reported that pre-membrane (prM)-reactive antibodies do not efficiently neutralize DENV infection but instead potently promote ADE infection. Meanwhile, these enhancing anti-prM antibodies mainly react with the precursor (pr) peptide. To evaluate the effect of pr gene substitution on neutralization and ADE of DENV infection, a novel chimeric dengue virus (JEVpr/DENV2) was rationally constructed by replacing the DENV pr gene with Japanese encephalitis virus (JEV) pr gene, based on the full-length infectious complementary DNA (cDNA) clone of DENV2 ZS01/01. We found that chimeric JEVpr/DENV2 showed reduced virulence and good immunogenicity. In addition, anti-JEVpr/DENV2 sera showed broad cross-reactivity and efficient neutralizing activity with all four DENV serotypes and immature DENV2 (ImDENV2). Most importantly, compared with anti-DENV2 sera, anti-JEVpr/DENV2 sera showed significantly reduced enhancing activity of DENV infection in K562 cells. These results suggest that the ADE activities could be reduced by replacing the DENV pr gene with JEV pr gene. These findings may help us better understand the pathogenesis of DENV infection and provide a reference for the development of a vaccine against DENV.


Assuntos
Anticorpos Antivirais/imunologia , Anticorpos Facilitadores , Vírus da Dengue/genética , Vírus da Dengue/imunologia , Vírus da Encefalite Japonesa (Subgrupo)/genética , Genética Reversa , Proteínas do Envelope Viral/metabolismo , Linhagem Celular , Humanos , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Recombinação Genética , Virulência
13.
Appl Microbiol Biotechnol ; 99(14): 5917-27, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25822571

RESUMO

Dengue vaccine development is considered a global public health priority, but the antibody-dependent enhancement (ADE) issues have critically restricted vaccine development. Recent findings have demonstrated that pre-membrane (prM) protein was involved in dengue virus (DENV) infection enhancement. Although the importance of prM antibodies have been well characterized, only a few epitopes in DENV prM protein have ever been identified. In this study, we screened five potential linear epitopes located at positions pr1 (1-16aa), pr3 (13-28aa), pr4 (19-34aa), pr9 (49-64aa), and pr10 (55-70aa) in pr protein using peptide scanning and comprehensive bioinformatics analysis. Then, we found that only pr4 (19-34aa) could elicit high-titer antibodies in Balb/c mice, and this epitope could react with sera from DENV2-infected patients, suggesting that specific antibodies against epitope peptide pr4 were elicited in both DENV-infected mice and human. In addition, our data demonstrated that anti-pr4 sera showed limited neutralizing activity but significant ADE activity toward standard DENV serotypes and imDENV. Hence, it seems responsible to hypothesize that anti-pr4 serum was infection-enhancing antibody and pr4 was infection-enhancing epitope. In conclusion, we characterized a novel infection-enhancing epitope on dengue pr protein, a finding that may provide new insight into the pathogenesis of DENV infection and contribute to dengue vaccine design.


Assuntos
Anticorpos Antivirais/imunologia , Anticorpos Facilitadores , Vírus da Dengue/imunologia , Vírus da Dengue/patogenicidade , Mapeamento de Epitopos , Epitopos de Linfócito B/imunologia , Proteínas do Envelope Viral/imunologia , Animais , Linhagem Celular , Humanos , Camundongos Endogâmicos BALB C
14.
Angew Chem Int Ed Engl ; 54(22): 6452-6, 2015 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-25864686

RESUMO

Sodium-ion batteries are a very promising alternative to lithium-ion batteries because of their reliance on an abundant supply of sodium salts, environmental benignity, and low cost. However, the low rate capability and poor long-term stability still hinder their practical application. A cathode material, formed of RuO2 -coated Na3 V2 O2 (PO4 )2 F nanowires, has a 50 nm diameter with the space group of I4/mmm. When used as a cathode material for Na-ion batteries, a reversible capacity of 120 mAh g(-1) at 1 C and 95 mAh g(-1) at 20 C can be achieved after 1000 charge-discharge cycles. The ultrahigh rate capability and enhanced cycling stability are comparable with high performance lithium cathodes. Combining first principles computational investigation with experimental observations, the excellent performance can be attributed to the uniform and highly conductive RuO2 coating and the preferred growth of the (002) plane in the Na3 V2 O2 (PO4 )2 F nanowires.

15.
BMC Microbiol ; 14: 233, 2014 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-25520151

RESUMO

BACKGROUND: Currently, a licensed vaccine for Dengue Virus (DENV) is not yet available. Virus-like particles (VLP) have shown considerable promise for use as vaccines and have many advantages compared to many other types of viral vaccines. VLPs have been found to have high immunogenic potencies, providing protection against various pathogens. RESULTS: In the current study, four DENV-VLP serotypes were successfully expressed in Pichia pastoris, based on co-expression of the prM and E proteins. The effects of a tetravalent VLP vaccine were also examined. Immunization with purified, recombinant, tetravalent DENV1-4 VLPs induced specific antibodies against all DENV1-4 antigens in mice. The antibody titers were higher after immunization with the tetravalent VLP vaccine compared to titers after immunization with any of the dengue serotype VLPs alone. Indirect immunofluorescence assay (IFA) results indicated that sera from VLP immunized mice recognized the native viral antigens. TNF-α and IL-10 were significantly higher in mice immunized with tetravalent DENV-VLP compared to those mice received PBS. The tetravalent VLP appeared to stimulate neutralizing antibodies against each viral serotype, as shown by PRNT50 analysis (1:32 against DENV1 and 2, and 1:16 against DENV3 and 4). The highest titers with the tetravalent VLP vaccine were still a little lower than the monovalent VLP against the corresponding serotype. The protection rates of tetravalent DENV-VLP immune sera against challenges with DENV1 to 4 serotypes in suckling mice were 77, 92, 100, and 100%, respectively, indicating greater protective efficacy compared with monovalent immune sera. CONCLUSIONS: Our results provide an important basis for the development of the dengue VLP as a promising non-infectious candidate vaccine for dengue infection.


Assuntos
Vacinas contra Dengue/imunologia , Dengue/prevenção & controle , Vacinas de Partículas Semelhantes a Vírus/imunologia , Animais , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Dengue/imunologia , Vacinas contra Dengue/administração & dosagem , Vacinas contra Dengue/genética , Vacinas contra Dengue/isolamento & purificação , Vírus da Dengue/genética , Vírus da Dengue/imunologia , Feminino , Técnica Indireta de Fluorescência para Anticorpo , Expressão Gênica , Imunização Passiva , Interleucina-10/metabolismo , Camundongos Endogâmicos BALB C , Testes de Neutralização , Pichia/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/metabolismo , Análise de Sobrevida , Fator de Necrose Tumoral alfa/metabolismo , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/genética , Vacinas Sintéticas/imunologia , Vacinas Sintéticas/isolamento & purificação , Vacinas de Partículas Semelhantes a Vírus/administração & dosagem , Vacinas de Partículas Semelhantes a Vírus/genética , Vacinas de Partículas Semelhantes a Vírus/isolamento & purificação , Proteínas do Envelope Viral/genética , Proteínas do Envelope Viral/imunologia , Proteínas do Envelope Viral/metabolismo
16.
Phys Chem Chem Phys ; 16(33): 17936-42, 2014 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-25050421

RESUMO

A novel sandwich-like structured Co-Al LDH-Carbon Nanotube (CNT) composite has been successfully synthesized by the elegant combination between exfoliated Co-Al LDH nanosheets and modified CNTs, which was achieved through an electrostatic assembly method. It is worth noting that the negatively charged CNTs, sandwiched between the positively charged nanosheets via the electrostatic force, can not only expand the area of contact of electrolyte ions but also highly improve the conductivity. The as-prepared Co-Al LDHs-CNTs composite exhibited a high specific capacitance of 884 F g(-1) and a good cycle stability over 2000 cycles. Therefore, such a facile synthetic route to fabricate the layered structure composite may open a new strategy to prepare other composites with largely enhanced electrochemical properties, which can be of great promise in energy storage device application.

17.
Genes (Basel) ; 15(3)2024 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-38540336

RESUMO

The flower's color is regarded as one of the most outstanding features of the rose. Rosa praelucens Byhouwer, an endemic and critically endangered decaploid wild rose species, is abundant in phenotypic diversity, especially in flower color variation, from white to different degrees of pink. The mechanism underlying this variation, e.g., the level of petal-color-related genes, is worth probing. Seven candidate reference genes for qRT-PCR analysis, including tubulin α chain (TUBA), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), histone H2B (Histone2A), eukaryotic translation elongation factor 1-α (EEF1A), 60S ribosomal protein (RPL37), eukaryotic translation initiation factor 1-α (EIF1A), and aquaporins (AQP), were detected from the transcriptome datasets of full blooming flowers of white-petaled and pink-petaled individuals, and their expression stabilities were evaluated through qRT-PCR analysis. According to stability rankings analysis, EEF1A showed the highest stability and could be chosen as the most suitable reference gene. Moreover, the reliability of EEF1A was demonstrated via qRT-PCR analysis of six petal-color-related target genes, the expression patterns of which, through EEF1A normalization, were found to be consistent with the findings of transcriptome analysis. The result provides an optimal reference gene for exploring the expression level of petal-color-related genes in R. praelucens, which will accelerate the dissection of petal-color-variation mechanisms in R. praelucens.


Assuntos
Rosa , Humanos , Rosa/genética , Reprodutibilidade dos Testes , Perfilação da Expressão Gênica , Transcriptoma , Reação em Cadeia da Polimerase
18.
Viruses ; 16(6)2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38932174

RESUMO

Influenza A viruses continue to be a serious health risk to people and result in a large-scale socio-economic loss. Avian influenza viruses typically do not replicate efficiently in mammals, but through the accumulation of mutations or genetic reassortment, they can overcome interspecies barriers, adapt to new hosts, and spread among them. Zoonotic influenza A viruses sporadically infect humans and exhibit limited human-to-human transmission. However, further adaptation of these viruses to humans may result in airborne transmissible viruses with pandemic potential. Therefore, we are beginning to understand genetic changes and mechanisms that may influence interspecific adaptation, cross-species transmission, and the pandemic potential of influenza A viruses. We also discuss the genetic and phenotypic traits associated with the airborne transmission of influenza A viruses in order to provide theoretical guidance for the surveillance of new strains with pandemic potential and the prevention of pandemics.


Assuntos
Adaptação ao Hospedeiro , Vírus da Influenza A , Influenza Humana , Humanos , Influenza Humana/transmissão , Influenza Humana/virologia , Influenza Humana/epidemiologia , Animais , Vírus da Influenza A/genética , Vírus da Influenza A/fisiologia , Influenza Aviária/transmissão , Influenza Aviária/virologia , Aves/virologia , Pandemias
19.
Ying Yong Sheng Tai Xue Bao ; 35(7): 1897-1906, 2024 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-39233419

RESUMO

Rosa multiflora, originated from East Asia, is one of the original ancestors of modern roses. It is also an important genetic resource and rootstock for rose cultivation. Due to its high resistance and vigorous growth, R. multiflora has become an invasive species in some introduction sites, such as North America. To explore the correlation between the suitable habitat of R. multiflora and climate change, we predicted its potential geographic distribution with an optimized MaxEnt model based on 1246 distribution records and nine bioclimatic variables. The results showed that the mean temperature of the coldest quarter, minimum temperature of the coldest month, precipitation of the warmest quarter, and isothermality were significant bioclimatic variables affecting the potential geographic distribution of R. multiflora. Under current climate conditions, R. multiflora naturally distributed in the plains and hilly areas to the east and south of the Loess Plateau. The distribution pattern in the mid-holocene was similar to its current distribution, but the highly suitable distribution area was in the south of North China Plain, the Sichuan Basin, and parts of the Middle-Lower Yangtze Plain. During the last interglacial, the suitable areas generally contrac-ted southward, while the highly suitable areas significantly expanded and mainly located in the Sichuan Basin, the Middle-Lower Yangtze Plains, the Yunnan-Guizhou Plateau, and the Southeast Hills. Beyond its natural distribution in East Asia, R. multiflora had been introduced and spread to most parts of Europe and the central and eastern United States. The distribution area of R. multiflora would expand under three warming scenarios of different shared socioeconomic pathways (SSP1-2.6, SSP2-4.5, and SSP5-8.5) during 2041-2060 and 2081-2100. Its average distribution center (centroid) would shift towards higher latitude, indicating that the distribution of R. multiflora was closely related to climate change and that global warming might lead to an expansion of its distribution area. These results would improve our understanding of the ecological adaptability of R. multiflora, facilitate the predicting of its future distribution, and provide a theoretical basis for monitoring and early warning measures following its introduction.


Assuntos
Mudança Climática , Ecossistema , Espécies Introduzidas , Rosa , Rosa/crescimento & desenvolvimento , China , Simulação por Computador , Dispersão Vegetal
20.
Emerg Microbes Infect ; 13(1): 2300762, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38164794

RESUMO

Ebola virus (EBOV) belongs to Filoviridae family possessing single-stranded negative-sense RNA genome, which is a serious threat to human health. Nowadays, no therapeutics have been proven to be successful in efficiently decreasing the mortality rate. RNA binding proteins (RBPs) are reported to participate in maintaining cell integrity and regulation of viral replication. However, little is known about whether and how RBPs participate in regulating the life cycle of EBOV. In our study, we found that RNA binding motif protein 4 (RBM4) inhibited the replication of EBOV in HEK293T and Huh-7 cells by suppressing viral mRNA production. Such inhibition resulted from the direct interaction between the RRM1 domain of RBM4 and the "CU" enrichment elements located in the PE1 and TSS of the 3'-leader region within the viral genome. Simultaneously, RBM4 could upregulate the expression of some cytokines involved in the host innate immune responses to synergistically exert its antiviral function. The findings therefore suggest that RBM4 might serve as a novel target of anti-EBOV strategy.


Assuntos
Ebolavirus , Doença pelo Vírus Ebola , Humanos , Ebolavirus/genética , RNA , Células HEK293 , Replicação Viral , Motivos de Ligação ao RNA , Genômica , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo
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