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In this paper, we study a time-delayed nonlocal reaction-diffusion model of within-host viral infections. We introduce the basic reproduction number R 0 and show that the infection-free steady state is globally asymptotically stable when R 0 ≤ 1 , while the disease is uniformly persistent when R 0 > 1 . In the case where all coefficients and reaction terms are spatially homogeneous, we obtain an explicit formula of R 0 and the global attractivity of the positive constant steady state. Numerically, we illustrate the analytical results, conduct sensitivity analysis, and investigate the impact of drugs on curtailing the spread of the viruses.
Assuntos
Viroses , Humanos , Número Básico de Reprodução , DifusãoRESUMO
Benzoxazinoids (BXs) are unique bioactive metabolites with protective and allelopathic properties in maize in response to diverse stresses. The production of BXs involves the fine regulations of BXs biosynthetic gene cluster (BGC). However, little is known about whether and how the expression pattern of BGC members is impacted by biotic and abiotic stresses. Here, maize BGC was systemically investigated and 26 BGC gene members were identified on seven chromosomes, for which Bin 4.00-4.01/4.03-4.04/7.02 were the most enriched regions. All BX proteins were clearly divided into three classes and seven subclasses, and ten conserved motifs were further identified among these proteins. These proteins were localized in the subcellular compartments of chloroplast, endoplasmic reticulum, or cytoplasmic, where their catalytic activities were specifically executed. Three independent RNA-sequencing (RNA-Seq) analyses revealed that the expression profiles of the majority of BGC gene members were distinctly affected by multiple treatments, including light spectral quality, low-temperature, 24-epibrassinolide induction, and Asian corn borer infestation. Thirteen differentially expressed genes (DEGs) with high and specific expression levels were commonly detected among three RNA-Seq, as core conserved BGC members for regulating BXs biosynthesis under multiple abiotic/biotic stimulates. Moreover, the quantitative real-time PCR (qRT-PCR) verified that six core conserved genes in BGC were significantly differentially expressed in leaves of seedlings upon four treatments, which caused significant increases in 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA) content under darkness and wound treatments, whereas a clear decrease in DIMBOA content was observed under low-temperature treatment. In conclusion, the changes in BX metabolites in maize were regulated by BGC gene members in multiple stress presences. Therefore, the identification of key genes associated with BX accumulation under biotic/abiotic stresses will provide valuable gene resources for breeding maize varieties with enhanced capability to adapt to environmental stresses.
Assuntos
Benzoxazinas , Regulação da Expressão Gênica de Plantas , Família Multigênica , Estresse Fisiológico , Zea mays , Zea mays/genética , Zea mays/metabolismo , Benzoxazinas/metabolismo , Estresse Fisiológico/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Perfilação da Expressão Gênica , FilogeniaRESUMO
In this research, the authors studied the synthesis of a silicon-based quaternary ammonium material based on the coupling agent chloromethyl trimethoxysilane (KH-150) as well as its adsorption and separation properties for Th(IV). Using FTIR and NMR methods, the silicon-based materials before and after grafting were characterized to determine the spatial structure of functional groups in the silicon-based quaternary ammonium material SG-CTSQ. Based on this, the functional group grafting amount (0.537 mmol·g-1) and quaternization rate (83.6%) of the material were accurately calculated using TGA weight loss and XPS. In the adsorption experiment, the four materials with different grafting amounts showed different degrees of variation in their adsorption of Th(IV) with changes in HNO3 concentration and NO3- concentration but all exhibited a tendency toward anion exchange. The thermodynamic and kinetic experimental results demonstrated that materials with low grafting amounts (SG-CTSQ1 and SG-CTSQ2) tended to physical adsorption of Th(IV), while the other two tended toward chemical adsorption. The adsorption mechanism experiment further proved that the functional groups achieve the adsorption of Th(IV) through an anion-exchange reaction. Chromatographic column separation experiments showed that SG-CTSQ has a good performance in U-Th separation, with a decontamination factor for uranium in Th(IV) of up to 385.1, and a uranium removal rate that can reach 99.75%.
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Multiple sclerosis (MS) is an inflammatory-mediated demyelinating disease of the central nervous system (CNS). Although studies have demonstrated that microglia facilitate remyelination in demyelinating diseases, the underlying mechanisms are still not fully characterized. We found that aryl hydrocarbon receptor (AhR), an environment sensor, was upregulated within the corpus callosum in the cuprizone model of CNS demyelination, and upregulated AhR was mainly confined to microglia. Deletion of AhR in adult microglia inhibited efficient remyelination. Transcriptome analysis using RNA-seq revealed that AhR-deficient microglia displayed impaired gene expression signatures associated with lysosome and phagocytotic pathways. Furthermore, AhR-deficient microglia showed impaired clearance of myelin debris and defected phagocytic capacity. Further investigation of target genes of AhR revealed that spleen tyrosine kinase (SYK) is the downstream effector of AhR and mediated the phagocytic capacity of microglia. Additionally, AhR deficiency in microglia aggravated CNS inflammation during demyelination. Altogether, our study highlights an essential role for AhR in microglial phagocytic function and suggests the therapeutic potential of AhR in demyelinating diseases.
Assuntos
Doenças Desmielinizantes , Receptores de Hidrocarboneto Arílico , Remielinização , Animais , Camundongos , Corpo Caloso/metabolismo , Cuprizona/toxicidade , Doenças Desmielinizantes/tratamento farmacológico , Modelos Animais de Doenças , Camundongos Endogâmicos C57BL , Microglia/metabolismo , Bainha de Mielina/metabolismo , Receptores de Hidrocarboneto Arílico/genética , Receptores de Hidrocarboneto Arílico/metabolismo , Remielinização/fisiologiaRESUMO
The transient receptor potential vanilloid 1 (TRPV1) is a non-selective cation channel that is activated by capsaicin (CAP), the main component of chili pepper. Despite studies in several neurological diseases, the role of TRPV1 in demyelinating diseases remains unknown. Herein, we reported that TRPV1 expression was increased within the corpus callosum during demyelination in a cuprizone (CPZ)-induced demyelination mouse model. TRPV1 deficiency exacerbated motor coordinative dysfunction and demyelination in CPZ-treated mice, whereas the TRPV1 agonist CAP improved the behavioral performance and facilitated remyelination. TRPV1 was predominantly expressed in Iba1+ microglia/macrophages in human brain sections of multiple sclerosis patients and mouse corpus callosum under demyelinating conditions. TRPV1 deficiency decreased microglial recruitment to the corpus callosum, with an associated increase in the accumulation of myelin debris. Conversely, the activation of TRPV1 by CAP enhanced the recruitment of microglia to the corpus callosum and potentiated myelin debris clearance. Using real-time live imaging we confirmed an increased phagocytic function of microglia following CAP treatment. In addition, the expression of the scavenger receptor CD36 was increased, and that of the glycolysis regulators Hif1a and Hk2 was decreased. We conclude that TRPV1 is an important regulator of microglial function in the context of demyelination and may serve as a promising therapeutic target for demyelinating diseases such as multiple sclerosis.
Assuntos
Doenças Desmielinizantes , Esclerose Múltipla , Animais , Humanos , Camundongos , Cuprizona , Doenças Desmielinizantes/induzido quimicamente , Doenças Desmielinizantes/tratamento farmacológico , Modelos Animais de Doenças , Camundongos Endogâmicos C57BL , Microglia/metabolismo , Esclerose Múltipla/tratamento farmacológico , Esclerose Múltipla/metabolismo , Bainha de Mielina/metabolismo , Canais de Cátion TRPV , Capsaicina/farmacologiaRESUMO
Many infectious diseases cannot be transmitted from human to human directly, and the transmission needs to be done via a vector. It is well known that vectors' life cycles are highly dependent on their living environment. In order to investigate dynamics of vector-borne diseases under environment influence, we propose a vector-borne disease model with almost periodic coefficients. We derive the basic reproductive number [Formula: see text] for this model and establish a threshold type result on its global dynamics in terms of [Formula: see text]. As an illustrative example, we consider an almost periodic model of malaria transmission. Our numerical simulation results show that the basic reproductive number may be underestimated if almost periodic coefficients are replaced by their average values . Finally, we use our model to study the dengue fever transmission in Guangdong, China. The parameters are chosen to fit the reported data available for Guangdong. Numerical simulations indicate that the annual dengue fever case in Guangdong will increase steadily in the near future unless more effective control measures are implemented. Sensitivity analysis implies that the parameters with strong impact on the outcome are recovery rate, mosquito recruitment rate, mosquito mortality rate, baseline transmission rates between mosquito and human. This suggests that the effective control strategies may include intensive treatment, mosquito control, decreasing human contact number with mosquitoes (e.g., using bed nets and preventing mosquito bites), and environmental modification.
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Dengue , Malária , Doenças Transmitidas por Vetores , Animais , Humanos , Mosquitos Vetores , Doenças Transmitidas por Vetores/epidemiologia , Doenças Transmitidas por Vetores/prevenção & controle , Malária/epidemiologia , Malária/prevenção & controle , Simulação por Computador , Dengue/epidemiologia , Dengue/prevenção & controleRESUMO
Maize seedlings contain high amounts of 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA), and the effect of DIMBOA is directly associated with multiple insect-resistance against insect pests such as Asian corn borer and corn leaf aphids. Although numerous genetic loci for multiple insect-resistant traits have been identified, little is known about genetic controls regarding DIMBOA content. In this study, the best linear unbiased prediction (BLUP) values of DIMBOA content in two ecological environments across 310 maize inbred lines were calculated; and their phenotypic data and BLUP values were used for marker-trait association analysis. We identified nine SSRs that were significantly associated with DIMBOA content, which explained 4.30-20.04% of the phenotypic variation. Combined with 47 original genetic loci from previous studies, we detected 19 hot loci and approximately 11 hot loci (in Bin 1.04, Bin 2.00-2.01, Bin 2.03-2.04, Bin 4.00-4.03, Bin 5.03, Bin 5.05-5.07, Bin 8.01-8.03, Bin 8.04-8.05, Bin 8.06, Bin 9.01, and Bin 10.04 regions) supported pleiotropy for their association with two or more insect-resistant traits. Within the 19 hot loci, we identified 49 candidate genes, including 12 controlling DIMBOA biosynthesis, 6 involved in sugar metabolism/homeostasis, 2 regulating peroxidases activity, 21 associated with growth and development [(auxin-upregulated RNAs (SAUR) family member and v-myb avian myeloblastosis viral oncogene homolog (MYB)], and 7 involved in several key enzyme activities (lipoxygenase, cysteine protease, restriction endonuclease, and ubiquitin-conjugating enzyme). The synergy and antagonism interactions among these genes formed the complex defense mechanisms induced by multiple insect pests. Moreover, sufficient genetic variation was reported for DIMBOA performance and SSR markers in the 310 tested maize inbred lines, and 3 highly (DIMBOA content was 402.74-528.88 µg g-1 FW) and 15 moderate (DIMBOA content was 312.92-426.56 µg g-1 FW) insect-resistant genotypes were major enriched in the Reid group. These insect-resistant inbred lines can be used as parents in maize breeding programs to develop new varieties.
Assuntos
Melhoramento Vegetal , Zea mays , Animais , Zea mays/genética , Insetos/genética , Variação Genética , Estudos de Associação GenéticaRESUMO
Synergetic elongation of mesocotyl and coleoptile are crucial in governing maize seedlings emergence, especially for the maize sown in deep soil. Studying the genomic regions controlling maize deep-sowing tolerance would aid the development of new varieties that are resistant to harsh conditions, such as drought and low temperature during seed germination. Using 346 F2:3 maize population families from W64A × K12 cross at three sowing depths, we identified 33 quantitative trait loci (QTLs) for the emergence rate, mesocotyl, coleoptile, and seedling lengths via composite interval mapping (CIM). These loci explained 2.89% to 14.17% of phenotypic variation in a single environment, while 12 of 13 major QTLs were identified at two or more sowing environments. Among those, four major QTLs in Bin 1.09, Bin 4.08, Bin 6.01, and Bin 7.02 supported pleiotropy for multiple deep-sowing tolerant traits. Meta-analysis identified 17 meta-QTLs (MQTLs) based on 130 original QTLs from present and previous studies. RNA-Sequencing of mesocotyl and coleoptile in both parents (W64A and K12) at 3 cm and 20 cm sowing environments identified 50 candidate genes expressed differentially in all major QTLs and MQTLs regions: six involved in the circadian clock, 27 associated with phytohormones biosynthesis and signal transduction, seven controlled lignin biosynthesis, five regulated cell wall organization formation and stabilization, three were responsible for sucrose and starch metabolism, and two in the antioxidant enzyme system. These genes with highly interconnected networks may form a complex molecular mechanism of maize deep-sowing tolerance. Findings of this study will facilitate the construction of molecular modules for deep-sowing tolerance in maize. The major QTLs and MQTLs identified could be used in marker-assisted breeding to develop elite maize varieties.
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Melhoramento Vegetal , Zea mays , Humanos , Zea mays/genética , Mapeamento Cromossômico , Locos de Características Quantitativas/genética , Fenótipo , Plântula/genética , RNARESUMO
Serotonin (5-HT), an indoleamine compound, has been known to mediate many physiological responses of plants under environmental stress. The deep-seeding (≥20 cm) of maize seeds is an important cultivation strategy to ensure seedling emergence and survival under drought stress. However, the role of 5-HT in maize deep-seeding tolerance remains unexplored. Understanding the mechanisms and evaluating the optimal concentration of 5-HT in alleviating deep-seeding stress could benefit maize production. In this study, two maize inbred lines were treated with or without 5-HT at both sowing depths of 20 cm and 3 cm, respectively. The effects of different concentrations of 5-HT on the growth phenotypes, physiological metabolism, and gene expression of two maize inbred lines were examined at the sowing depths of 20 cm and 3 cm. Compared to the normal seedling depth of 3 cm, the elongation of the mesocotyl (average elongation 3.70 cm) and coleoptile (average elongation 0.58 cm), secretion of indole-3-acetic acid (IAA; average increased 3.73 and 0.63 ng g-1 FW), and hydrogen peroxide (H2O2; average increased 1.95 and 0.63 µM g-1 FW) in the mesocotyl and coleoptile were increased under 20 cm stress, with a concomitant decrease in lignin synthesis (average decreased 0.48 and 0.53 A280 g-1). Under 20 cm deep-seeding stress, the addition of 5-HT activated the expression of multiple genes of IAA biosynthesis and signal transduction, including Zm00001d049601, Zm00001d039346, Zm00001d026530, and Zm00001d049659, and it also stimulated IAA production in both the mesocotyl and coleoptile of maize seedlings. On the contrary, 5-HT suppressed the expression of genes for lignin biosynthesis (Zm00001d016471, Zm00001d005998, Zm00001d032152, and Zm00001d053554) and retarded the accumulation of H2O2 and lignin, resulting in the elongation of the mesocotyl and coleoptile of maize seedlings. A comprehensive evaluation analysis showed that the optimum concentration of 5-HT in relieving deep-seeding stress was 2.5 mg/L for both inbred lines, and 5-HT therefore could improve the seedling emergence rate and alleviate deep-seeding stress in maize seedlings. These findings could provide a novel strategy for improving maize deep-seeding tolerance, thus enhancing yield potential under drought and water stress.
Assuntos
Cotilédone , Plântula , Plântula/metabolismo , Cotilédone/metabolismo , Zea mays/metabolismo , Serotonina/metabolismo , Lignina/metabolismo , Peróxido de Hidrogênio/metabolismo , Ácidos Indolacéticos/farmacologia , Ácidos Indolacéticos/metabolismoRESUMO
INTRODUCTION: Posterolateral approach has been advocated for the treatment of ankle fractures involving the posterior malleolus and satisfactory results were demonstrated in several studies. The Bartonicek classification based on 3-dimensional CT scanning was commonly used for treatment recommendation of posterior malleolar fracture (PMF). The aim of this retrospective study was to evaluate the clinical effect of the posterolateral approach for the treatment of PMF and present outcomes of patients with different types of Bartonicek classification. METHOD: We retrospectively reviewed the clinical outcomes of 72 patients with ankle fractures involving posterior malleolus (PM) from January 2016 to December 2018. Posterior malleolus fractures (PMFs) were all directly reduced and fixed by a posterolateral approach using lag screws and/or buttress plates. AOFAS score and VAS pain score were used as the primary functional outcome measures. The radiographic evaluation included the quality of the reduction and Kellgren-Lawrence (KL) osteoarthritis classification. According to the CT-based Bartonicek classification, all patients were classified into three groups: 42 type II, 18 type III and 12 type IV. Bartonicek type II patients were further divided into subtype IIa 19 cases, subtype IIb 16 cases and subtype IIc 7 cases. The radiological and functional outcomes were analyzed among different types and subtypes of Bartonicek classification. RESULTS: Sixty-eight patients (94.5%) achieved good or excellent reduction of PMF after surgery. The mean AOFAS score was 81.35 ± 6.15 at 6 months and 90.56 ± 4.98 at the final follow-up, respectively. The VAS score was 6.62 ± 1.03 one week after surgery, and 1.20 ± 0.92 at the final follow-up. Radiological evaluation at the final follow-up showed that primary bone union was achieved in all patients and 65 patients (88.9%) got no (KL grade 0) or just doubtable (KL grade 1) post-traumatic osteoarthritis. AOFAS scores decreased significantly with the severity of Bartonicek classification at 6 month (p < 0.001) and final follow-up (p < 0.05), while there was no statistical difference of VAS pain score among different types of Bartonicek classification. Reduction quality and the presence of osteoarthritis was not correlated to Bartonicek classification either. Besides, AOFAS scores at the final follow-up were statistically different among three subtypes of Bartonicek type II fractures (p < 0.05), and Bartonicek subtype IIa fractures had the highest AOFAS scores as 93 ± 4.99. Presence and severity of osteoarthritis was lower in patients with subtype IIa PMF compared to other subtype groups, this finding was statistically significant (p < 0.05). CONCLUSION: The posterolateral approach could achieve good clinical outcomes in the treatment of posterior malleolus fracture. Patients with a Bartonicek type II fracture had a better functional outcome measured by the AOFAS score compared to other types. Bartonicek type IIa fractures got a higher AOFAS score and a lower incidence of osteoarthritis at the final follow-up than the other two subtypes. Classification of PMFs according to the Bartonicek classification was reliable.
Assuntos
Fraturas do Tornozelo , Osteoartrite , Humanos , Fraturas do Tornozelo/diagnóstico por imagem , Fraturas do Tornozelo/cirurgia , Estudos Retrospectivos , Fixação Interna de Fraturas/métodos , Articulação do Tornozelo/cirurgia , Dor , Resultado do TratamentoRESUMO
Twenty-three new riminophenazine and pyrido[3,2-b]quinoxaline derivatives were prepared and examined for their antimycobacterial activities against Mycobacterium marinum and Mycobacterium tuberculosis H37Rv, taking clofazimine (1) as the lead. Structure-activity relationship (SAR) analysis revealed that the introduction of a heterocycle or diethylamine substituted benzene moiety on the N-5 atom might be beneficial for activity. The most potent compound 7m also displayed enhanced activity against wild-type as well as multidrug-resistant (MDR) and extensively drug-resistant (XDR) TB clinical isolates, with the MICs ranging from 0.08 to 1.25 µg/mL, especially effective toward strain M20A507, resistant to 1. Further mechanism study indicated that its anti-TB activity was independent of cell membrane disruption, but related to NDH-2 reduction and the resulting high ROS production. Our study provides instructive guidance for the further development of clofazimine derivatives into promising antimicrobial agents against MDR and XDR TB.
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Mycobacterium tuberculosis , Tuberculose Resistente a Múltiplos Medicamentos , Antituberculosos/farmacologia , Clofazimina/farmacologia , Humanos , Testes de Sensibilidade Microbiana , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico , Tuberculose Resistente a Múltiplos Medicamentos/microbiologiaRESUMO
Cholera is a water- and food-borne infectious disease caused by V. cholerae. To investigate multiple effects of human behavior change, seasonality and spatial heterogeneity on cholera spread, we propose a reaction-advection-diffusion model that incorporates human hosts and aquatic reservoir of V. cholerae. We derive the basic reproduction number [Formula: see text] for this system and then establish a threshold type result on its global dynamics in terms of [Formula: see text]. Further, we show that the bacterial loss at the downstream end of the river due to water flux can reduce the disease risk, and describe the asymptotic behavior of [Formula: see text] for small and large diffusion in a special case (where the diffusion rates of infected human and the pathogen are constant). We also study the transmission dynamics at the early stage of cholera outbreak numerically, and find that human behavior change may lower the infection level and delay the disease peak. Moreover, the relative rate of bacterial loss, together with convection rate, plays an important role in identifying the severely infected areas. Meanwhile spatial heterogeneity may dilute or amplify cholera infection, which in turn would increase the complexity of disease spread.
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Cólera , Epidemias , Vibrio cholerae , Número Básico de Reprodução , Cólera/epidemiologia , Humanos , Modelos BiológicosRESUMO
Deep-seeding is an important way to improve maize drought resistance, mesocotyl elongation can significantly enhance its seedling germination. To improve our understanding of transcription-mediated maize mesocotyl elongation under deep-seeding stress. RNA-sequencing was used to identify differentially expressed genes (DEGs) in both deep-seeding tolerant W64A and intolerant K12 mesocotyls following culture for 10 days after 2.0 mg·L-1 24-epibrassinolide (EBR) induced stress at the depths of 3 and 20 cm. Phenotypically, the mesocotyl length of both maize significantly increased under 20 cm stress and in the presence of EBR. Microstructure observations revealed that the mesocotyls underwent programmed cell death under deep-seeding stress, which was alleviated by EBR. This was found to be regulated by multiple DEGs encoding cysteine protease/senescence-specific cysteine protease, aspartic protease family protein, phospholipase D, etc. and transcription factors (TFs; MYB, NAC). Additionally, some DEGs associated with cell wall components, i.e., cellulose synthase/cellulose synthase like protein (CESA/CSL), fasciclin-like arabinogalactan (APG), leucine-rich repeat protein (LRR) and lignin biosynthesis enzymes including phenylalanine ammonia-lyase, S-adenosyl-L-methionine-dependent methyltransferases, 4-coumarate-CoA ligase, cinnamoyl CoA reductase, cinnamyl alcohol dehydrogenase, catalase, peroxiredoxin/peroxidase were found to control cell wall sclerosis. Moreover, in auxin, ethylene, brassinosteriod, cytokinin, zeatin, abscisic acid, gibberellin, jasmonic acid, and salicylic acid signaling transduction pathways, the corresponding DEGs were activated/inhibited by TFs (ARF, BZR1/2, B-ARR, A-ARR, MYC2, ABF, TGA) and synthesis of phytohormones-related metabolites. These findings provide information on the molecular mechanisms controlling maize deep-seeding tolerance and will aid in the breeding of deep-seeding maize varieties.
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Brassinosteroides , Zea mays , Brassinosteroides/metabolismo , Regulação da Expressão Gênica de Plantas , Melhoramento Vegetal , RNA/metabolismo , Análise de Sequência de RNA , Estresse Fisiológico/genética , Zea mays/genética , Zea mays/metabolismoRESUMO
Mesocotyl length (MES) is an important trait that affects the emergence of maize seedlings after deep-seeding and is closely associated with abiotic stress. The elucidation of constitutive-QTLs (cQTLs) and candidate genes for MES and tightly molecular markers are thus of great importance in marker-assisted selection (MAS) breeding. Therefore, the objective of this study was to perform detailed genetic analysis of maize MES across 346 F2:3 families, 30/30 extreme bulks of an F2 population, and two parents by conventional QTL analysis, bulked-segregation analysis (BSA), and RNA-sequencing when maize was sown at the depths of 3, 15, and 20 cm, respectively. QTL analysis identified four major QTLs in Bin 1.09, Bin 3.04, Bin 4.06-4.07, and Bin 6.01 under two or more environments, which explained 2.89-13.97% of the phenotypic variance within a single environment. BSA results revealed the presence of seven significantly linked SNP/InDel regions on chromosomes 1 and 4, and six SNP/InDel regions and the major QTL of qMES4-1 overlapped and formed a cQTL, cQMES4, within the 160.98-176.22 Mb region. In total, 18,001 differentially expressed genes (DEGs) were identified across two parents by RNA-sequencing, and 24 of these genes were conserved core DEGs. Finally, we validated 15 candidate genes in cQMES4 to involve in cell wall structure, lignin biosyntheis, phytohormones (auxin, abscisic acid, brassinosteroid) signal transduction, circadian clock, and plant organ formation and development. Our findings provide a basis for MAS breeding and enhance our understanding of the deep-seeding tolerance of maize.
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Locos de Características Quantitativas , Zea mays , Mapeamento Cromossômico/métodos , Humanos , Fenótipo , RNA , Análise de Sequência de RNA , Zea mays/genéticaRESUMO
A determination method for trace 24-epibrassinolide (EBL) in plant tissues was developed using ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The plant tissue samples were extracted using a methanol-formic acid solution, and the corresponding supernatant was purified with ODS C18 solid-phase extraction column. The extracts were separated using a Zorbax Eclipse Plus C18 (2.1 mm × 50 mm, 1.8 µm) column with methanol and 0.1% formic acid as the mobile phase. The ion source for the mass spectrometry was an electrospray ionization source with positive ion mode detection. The linear range of the target compound was 0.7~104 µg/kg, the limit of detection (LOD) was 0.11~0.37 µg/kg, the limit of quantification (LOQ) was 0.36~1.22 µg/kg, the recovery rate was 84.0~116.3%, and the relative standard deviation (RSD%) was 0.8~10.5. The samples of maize plumule, brassica rapeseed flower, and marigold leaf were detected using the external standard method. The optimization of the extraction method and detection method of EBL improved the detection sensitivity, laid a foundation for the artificial synthesis of EBL, improved the extraction rate of EBL, and provided a theoretical basis for the study of EBL in many plants.
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Brassica napus/química , Brassinosteroides , Flores/química , Folhas de Planta/química , Zea mays/química , Brassinosteroides/química , Brassinosteroides/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Cromatografia Líquida , Avaliação de Medicamentos , Espectrometria de Massas em TandemRESUMO
In this paper, we propose a periodic reaction-diffusion model of Zika virus with seasonal and spatial heterogeneous structure in host and vector population. We introduce the basic reproduction ratio [Formula: see text] for this model and show that the disease-free periodic solution is globally asymptotically stable if [Formula: see text], while the system admits a globally asymptotically stable positive periodic solution if [Formula: see text]. Numerically, we study the Zika transmission in Rio de Janeiro Municipality, Brazil, and investigate the effects of some model parameters on [Formula: see text]. We find that the neglect of seasonality underestimates the value of [Formula: see text] and the maximum carrying capacity affects the spread of Zika virus.
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Modelos Biológicos , Infecção por Zika virus , Brasil , Humanos , Estações do Ano , Zika virus , Infecção por Zika virus/epidemiologia , Infecção por Zika virus/transmissãoRESUMO
BACKGROUND: Although hematologic review criteria for general hospitals have been established, they may be insufficient for cancer hospitals. This study aimed to establish the appropriate review criteria for hematology analyzers in cancer hospitals. METHODS: A total of 1003 samples from our hospital were randomly selected for blood smear preparation and microscopic review. The review criteria of the International Consensus Group for Hematology Review (ICGH) and Chinese consensus group were used to obtain the review, true-negative (TN), true-positive (TP), false-negative (FN), and false-positive (FP) rates, as well as the triggered rules. Our review criteria were established by comparing flag or numeric value information of TP and FP samples, adjusting rules to obtain better efficiency, a low slide review rate, and an acceptable FN rate. RESULTS: Overall, 197 (19.64%) samples showed positive smear findings. Compared to the ICGH criteria, the slide review rate of the newly established criteria declined from 51.25% to 39.28%, and the TP and TN rates increased from 17.85% and 46.06% to 23.13% and 55.83%, respectively. The FN rate of the newly established criteria was 3.69%. Another set of samples used to validate the newly established criteria yielded the review, FN, and FP rates as 33.49%, 1.86%, and 25.58%, respectively. CONCLUSION: The newly established review criteria for hematology analyzers enabled the prompt identification, smear, and further verification of doubtful specimens, without a significant increase in the workload, thus improving the efficiency of the review process. This study provided data support for other cancer hospitals to establish review criteria.
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Institutos de Câncer , Testes Hematológicos/instrumentação , Testes Hematológicos/normas , Laboratórios Hospitalares , Eritrócitos/patologia , Reações Falso-Negativas , Reações Falso-Positivas , Testes Hematológicos/métodos , Humanos , Leucócitos/patologia , Linfócitos/patologiaRESUMO
The biological activities of the primary metabolites and secondary metabolites of 69 green cabbage varieties were tested. The LC-MS detection method was used to determine the content of 19 free amino acids (lysine, tryptophan, phenylalanine, methionine, threonine, isoleucine, leucine, valine, arginine, asparagine, glycine, proline, tyrosine, glutamine, alanine, aspartic acid, serine, and glutamate). The content of 10 polyphenols (chlorogenic acid, gallic acid, 4-coumaric acid, ferulic acid, gentisic acid, cymarin, erucic acid, benzoic acid, rutin, and kaempferol) was determined by the HPLC detection method. Considering the complexity of the data obtained, variance analysis, diversity analysis, correlation analysis, hierarchical cluster analysis (HCA), and principal component analysis (PCA) were used to process and correlate amino acid or polyphenol data, respectively. The results showed that there were significant differences between the different amino acids and polyphenols of the 69 cabbage varieties. The most abundant amino acids and polyphenols were Glu and rutin, respectively. Both amino acids and polyphenols had a high genetic diversity, and multiple groups of significant or extremely significant correlations. The 69 cabbage varieties were divided into two groups, according to 19 amino acid indexes, by PCA. Among them, seven varieties with high amino acid content all fell into the fourth quadrant. The HCA of amino acids also supports this view. Based on 10 polyphenols, the 69 cabbage varieties were divided into two groups by HCA. Based on 29 indexes of amino acids and polyphenols, 69 cabbage varieties were evaluated and ranked by PCA. Therefore, in this study, cabbage varieties were classified in accordance with the level of amino acids and polyphenols, which provided a theoretical basis for the genetic improvement of nutritional quality in cabbage.
Assuntos
Aminoácidos/análise , Brassica/química , Polifenóis/análise , Análise MultivariadaRESUMO
KEY MESSAGE: CRISPR-edited variants at the 3'-end of OsLOGL5's coding sequence (CDS), significantly increased rice grain yield under well-watered, drought, normal nitrogen, and low nitrogen field conditions at multiple geographical locations. Cytokinins impact numerous aspects of plant growth and development. This study reports that constitutive ectopic overexpression of a rice cytokinin-activation enzyme-like gene, OsLOGL5, significantly reduced primary root growth, tiller number, and yield. Conversely, mutations at the 3'-end of OsLOGL5 CDS resulted in normal rice plant morphology but with increased grain yield under well-watered, drought, normal nitrogen, and low nitrogen field conditions at multiple geographical locations. Six gene edited variants (Edit A to F) were created and tested in the field. Edit-B and Edit-F plants increased, but Edit-D and Edit-E plants decreased, the panicle number per plant. All OsLOGL5-edited plants significantly increased seed setting rate, total grain numbers, full-filled grain numbers per panicle, and thousand seed weight under drought conditions, suggesting that OsLOGL5 is likely involved in the regulation of both seed development and grain filling processes. Our results indicate that the C-terminal end of OsLOGL5 protein plays an important role in regulating rice yield improvement under different abiotic stress conditions, and OsLOGL5 is important for rice yield enhancement and stability.