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1.
EMBO Rep ; 24(11): e56850, 2023 11 06.
Artigo em Inglês | MEDLINE | ID: mdl-37846507

RESUMO

The remodeling and stiffening of the extracellular matrix (ECM) is a well-recognized modulator of breast cancer progression. How changes in the mechanical properties of the ECM are converted into biochemical signals that direct tumor cell migration and metastasis remain poorly characterized. Here, we describe a new role for the autophagy-inducing serine/threonine kinases ULK1 and ULK2 in mechanotransduction. We show that ULK1/2 activity inhibits the assembly of actin stress fibers and focal adhesions (FAs) and as a consequence impedes cell contraction and migration, independent of its role in autophagy. Mechanistically, we identify PXN/paxillin, a key component of the mechanotransducing machinery, as a direct binding partner and substrate of ULK1/2. ULK-mediated phosphorylation of PXN at S32 and S119 weakens homotypic interactions and liquid-liquid phase separation of PXN, impairing FA assembly, which in turn alters the mechanical properties of breast cancer cells and their response to mechanical stimuli. ULK1/2 and the well-characterized PXN regulator, FAK/Src, have opposing functions on mechanotransduction and compete for phosphorylation of adjacent serine and tyrosine residues. Taken together, our study reveals ULK1/2 as important regulator of PXN-dependent mechanotransduction.


Assuntos
Neoplasias da Mama , Humanos , Feminino , Paxilina/metabolismo , Mecanotransdução Celular , Fosforilação , Movimento Celular , Serina/metabolismo , Proteína Homóloga à Proteína-1 Relacionada à Autofagia/genética , Proteína Homóloga à Proteína-1 Relacionada à Autofagia/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo
2.
BMC Med Educ ; 24(1): 62, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38225611

RESUMO

BACKGROUND: Modern medicine emphasizes that medical professionals engage in interprofessional collaboration to better meet the diverse needs of patients from physical, psychological, and social perspectives. As nursing students are the future reserve of the clinical nursing workforce, nursing educators worldwide should pay close attention to nursing students' interprofessional learning attitudes and take responsibility for training qualified interprofessional nursing personnel. However, little is known about the relationship between nursing students' readiness for interprofessional learning and academic self-efficacy. Thus, this study aims to investigate the level of readiness for interprofessional learning and academic self-efficacy among nursing students, and to explore the relationship between the two. METHODS: A cross-sectional survey was conducted with a sample of 741 undergraduate nursing students pursuing four-year degrees from a school in Jinan, Shandong Province, China from November to December 2021. The social-demographic questionnaire, Readiness for Interprofessional Learning Scale, and Academic Self-efficacy Scale were used for data collection. Descriptive statistics used to analyze the data included: Cronbach's alpha, t-test, one-way ANOVA, Pearson's correlation, and multiple linear regression analysis. RESULTS: Readiness for interprofessional learning mean score was (3.91 ± 0.44) and mean academic self-efficacy was (3.47 ± 0.42). Significant differences were found in the research variables according to participants' sex, grade, choice of nursing profession, and frequency of communication with health-related major students in studies (p < 0.05, p < 0.001). Pearson correlation analysis showed that academic self-efficacy was positively related to readiness for interprofessional learning (r = 0.316, p < 0.01). The hierarchical regression analysis showed that academic self-efficacy was positively related to readiness for interprofessional learning (ß = 0.307, p < 0.001), The model explained 15.6% of the variance in readiness for interprofessional learning (F = 18.038, p < 0.001). CONCLUSIONS: Readiness for interprofessional learning and academic self-efficacy were in the middle level among nursing students. Moreover, there was a significant positive correlation between the two. Therefore, it is very important for nursing educators to improve nursing students' academic self-efficacy before improving their readiness for interprofessional learning.


Assuntos
Bacharelado em Enfermagem , Estudantes de Ciências da Saúde , Estudantes de Enfermagem , Humanos , Estudantes de Enfermagem/psicologia , Estudos Transversais , Estudantes de Ciências da Saúde/psicologia , Autoeficácia , Atitude do Pessoal de Saúde , Inquéritos e Questionários , Relações Interprofissionais
3.
Int J Mol Sci ; 24(10)2023 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-37240101

RESUMO

Lampriform fishes (Lampriformes), which primarily inhabit deep-sea environments, are large marine fishes varying from the whole-body endothermic opah to the world's longest bony fish-giant oarfish, with species morphologies varying from long and thin to deep and compressed, making them an ideal model for studying the adaptive radiation of teleost fishes. Moreover, this group is important from a phylogenetic perspective owing to their ancient origins among teleosts. However, knowledge about the group is limited, which is, at least partially, due to the dearth of recorded molecular data. This study is the first to analyze the mitochondrial genomes of three lampriform species (Lampris incognitus, Trachipterus ishikawae, and Regalecus russelii) and infer a time-calibrated phylogeny, including 68 species among 29 orders. Our phylomitogenomic analyses support the classification of Lampriformes as monophyletic and sister to Acanthopterygii; hence, addressing the longstanding controversy regarding the phylogenetic status of Lampriformes among teleosts. Comparative mitogenomic analyses indicate that tRNA losses existed in at least five Lampriformes species, which may reveal the mitogenomic structure variation associated with adaptive radiation. However, codon usage in Lampriformes did not change significantly, and it is hypothesized that the nucleus transported the corresponding tRNA, which led to function substitutions. The positive selection analysis revealed that atp8 and cox3 were positively selected in opah, which might have co-evolved with the endothermic trait. This study provides important insights into the systematic taxonomy and adaptive evolution studies of Lampriformes species.


Assuntos
Genoma Mitocondrial , Animais , Filogenia , Peixes/genética , RNA de Transferência/genética
4.
Int J Mol Sci ; 24(20)2023 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-37895011

RESUMO

Fruit ripening is a highly complicated process that is accompanied by the formation of fruit quality. In recent years, a series of studies have demonstrated post-transcriptional control play important roles in fruit ripening and fruit quality formation. Till now, the post-transcriptional mechanisms for watermelon fruit ripening have not been comprehensively studied. In this study, we conducted PacBio single-molecule long-read sequencing to identify genome-wide alternative splicing (AS), alternative polyadenylation (APA) and long non-coding RNAs (lncRNAs) in watermelon fruit. In total, 6,921,295 error-corrected and mapped full-length non-chimeric (FLNC) reads were obtained. Notably, more than 42,285 distinct splicing isoforms were derived from 5,891,183 intron-containing full-length FLNC reads, including a large number of AS events associated with fruit ripening. In addition, we characterized 21,506 polyadenylation sites from 11,611 genes, 8703 of which have APA sites. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that fructose and mannose metabolism, starch and sucrose metabolism and carotenoid biosynthesis were both enriched in genes undergoing AS and APA. These results suggest that post-transcriptional regulation might potentially have a key role in regulation of fruit ripening in watermelon. Taken together, our comprehensive PacBio long-read sequencing results offer a valuable resource for watermelon research, and provide new insights into the molecular mechanisms underlying the complex regulatory networks of watermelon fruit ripening.


Assuntos
Processamento Alternativo , Citrullus , Citrullus/genética , Citrullus/metabolismo , Poliadenilação , Frutas/genética , Frutas/metabolismo , Splicing de RNA , Regulação da Expressão Gênica de Plantas
5.
J Integr Plant Biol ; 65(10): 2336-2348, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37219233

RESUMO

Watermelon (Citrullus lanatus) as non-climacteric fruit is domesticated from the ancestors with inedible fruits. We previously revealed that the abscisic acid (ABA) signaling pathway gene ClSnRK2.3 might influence watermelon fruit ripening. However, the molecular mechanisms are unclear. Here, we found that the selective variation of ClSnRK2.3 resulted in lower promoter activity and gene expression level in cultivated watermelons than ancestors, which indicated ClSnRK2.3 might be a negative regulator in fruit ripening. Overexpression (OE) of ClSnRK2.3 significantly delayed watermelon fruit ripening and suppressed the accumulation of sucrose, ABA and gibberellin GA4 . Furthermore, we determined that the pyrophosphate-dependent phosphofructokinase (ClPFP1) in sugar metabolism pathway and GA biosynthesis enzyme GA20 oxidase (ClGA20ox) could be phosphorylated by ClSnRK2.3 and thereby resulting in accelerated protein degradation in OE lines and finally led to low levels of sucrose and GA4 . Besides that, ClSnRK2.3 phosphorylated homeodomain-leucine zipper protein (ClHAT1) and protected it from degradation to suppress the expression of the ABA biosynthesis gene 9'-cis-epoxycarotenoid dioxygenase 3 (ClNCED3). These results indicated that ClSnRK2.3 negatively regulated watermelon fruit ripening by manipulating the biosynthesis of sucrose, ABA and GA4 . Altogether, these findings revealed a novel regulatory mechanism in non-climacteric fruit development and ripening.


Assuntos
Citrullus , Frutas , Frutas/metabolismo , Açúcares/metabolismo , Citrullus/genética , Citrullus/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Sacarose/metabolismo , Ácido Abscísico/metabolismo
6.
New Phytol ; 236(1): 165-181, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35739643

RESUMO

In acidic soils, aluminum (Al) toxicity is the main factor inhibiting plant root development and reducing crops yield. STOP1 (SENSITIVE TO PROTON RHIZOTOXICITY 1) was a critical factor in detoxifying Al stress. Under Al stress, STOP1 expression was not induced, although STOP1 protein accumulated, even in the presence of RAE1 (STOP1 DEGRADATION E3-LIGASE). How the Al stress triggers and stabilises the accumulation of STOP1 is still unknown. Here, we characterised SlSTOP1-interacting zinc finger protein (SlSZP1) using a yeast-two-hybrid screening, and generated slstop1, slszp1 and slstop1/slszp1 knockout mutants using clustered regularly interspaced short palindromic repeats (CRISPR) in tomato. SlSZP1 is induced by Al stress but it is not regulated by SlSTOP1. The slstop1, slszp1 and slstop1/slszp1 knockout mutants exhibited hypersensitivity to Al stress. The expression of SlSTOP1-targeted genes, such as SlRAE1 and SlASR2 (ALUMINUM SENSITIVE), was inhibited in both slstop1 and slszp1 mutants, but not directly regulated by SlSZP1. Furthermore, the degradation of SlSTOP1 by SlRAE1 was prevented by SlSZP1. Al stress increased the accumulation of SlSTOP1 in wild-type (WT) but not in slszp1 mutants. The overexpression of either SlSTOP1 or SlSZP1 did not enhance plant Al resistance. Altogether, our results show that SlSZP1 is an important factor for protecting SlSTOP1 from SlRAE1-mediated degradation.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Alumínio/metabolismo , Alumínio/toxicidade , Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas , Raízes de Plantas/metabolismo , Fatores de Transcrição/metabolismo , Dedos de Zinco
7.
Theor Appl Genet ; 135(5): 1565-1578, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35187585

RESUMO

KEY MESSAGE: The mutation of ClZISO identified in EMS-induced watermelon leads to photosensitive flesh in watermelon. Watermelon (Citrullus lanatus) has a colorful flesh that attracts consumers and benefits human health. We developed an ethyl-methanesulfonate mutation library in red-fleshed line '302' to create new flesh color lines and found a yellow-fleshed mutant which accumulated ζ-carotene. The initial yellow color of this mutant can be photobleached within 10 min under intense sunlight. A long-term light-emitting diode (LED) light treatment turned flesh color from yellow to pink. We identified this unique variation as photosensitive flesh mutant ('psf'). Using bulked segregant analysis, we fine-mapped an EMS-induced G-A transversion in 'psf' which leads to a premature stop codon in 15-cis-ζ-carotene isomerase (ClZISO) gene. We detected that wild-type ClZISO is expressed in chromoplasts to catalyze the conversion of 9,15,9'-tri-cis-ζ-carotene to 9,9'-di-cis-ζ-carotene. The truncated ClZISOmu protein in psf lost this catalytic function. Light treatment can partially compensate ClZISOmu isomerase activity via photoisomerization in vitro and in vivo. Transcriptome analysis showed that most carotenoid biosynthesis genes in psf were downregulated. The dramatic increase of ABA content in flesh with fruit development was blocked in psf. This study explores the molecular mechanism of carotenoid biosynthesis in watermelon and provides a theoretical and technical basis for breeding different flesh color lines in watermelon.


Assuntos
Citrullus , Carotenoides/metabolismo , Frutas , Humanos , Isomerases/genética , Isomerases/metabolismo , Mutação , Pigmentação/genética , Melhoramento Vegetal , zeta Caroteno/metabolismo
8.
Appl Opt ; 61(6): 1275-1283, 2022 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-35201006

RESUMO

A base plasmonic metal-insulator-metal (MIM) waveguide structure consisting of a baffle waveguide and an obround-shaped resonator is designed to produce Fano resonance. The simulation results exhibit that double Fano resonances can be achieved. Based on this structure, an inner obround-shaped resonator is spliced to the former obround-shaped resonator through a slot resonator to form the expanded structure. Then quadruple Fano resonances are produced by the interference between the broadband continuous state arising from the baffle waveguide and the narrowband discrete state arising from the interaction among the inner obround-shaped resonator, the outer obround-shaped resonator, and the slot resonator. The Fano resonance and refractive index sensing characteristics are investigated, and the sensitivity and the figure of merit can reach 1636 nm/RIU and 33562, respectively. Furthermore, the structure filled with blood plasma can be used for detecting plasma concentrations with different refractive indices, and the sensitivity can reach 2.88nm⋅L/g. The proposed structure with the simple baffle waveguide and obround-shaped resonators may have potential applications in biosensing and nanoscale optical sensing.


Assuntos
Metais , Refratometria , Simulação por Computador , Metais/química , Plasma
9.
J Integr Plant Biol ; 64(7): 1448-1461, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35568969

RESUMO

The NAC transcription factor NONRIPENING (NOR) is a master regulator of climacteric fruit ripening. Melon (Cucumis melo L.) has climacteric and non-climacteric fruit ripening varieties and is an ideal model to study fruit ripening. Two natural CmNAC-NOR variants, the climacteric haplotype CmNAC-NORS,N and the non-climacteric haplotype CmNAC-NORA,S , have effects on fruit ripening; however, their regulatory mechanisms have not been elucidated. Here, we report that a natural mutation in the transcriptional activation domain of CmNAC-NORS,N contributes to climacteric melon fruit ripening. CmNAC-NOR knockout in the climacteric-type melon cultivar "BYJH" completely inhibited fruit ripening, while ripening was delayed by 5-8 d in heterozygous cmnac-nor mutant fruits. CmNAC-NOR directly activated carotenoid, ethylene, and abscisic acid biosynthetic genes to promote fruit coloration and ripening. Furthermore, CmNAC-NOR mediated the transcription of the "CmNAC-NOR-CmNAC73-CmCWINV2" module to enhance flesh sweetness. The transcriptional activation activity of the climacteric haplotype CmNAC-NORS,N on these target genes was significantly higher than that of the non-climacteric haplotype CmNAC-NORA,S . Moreover, CmNAC-NORS,N complementation fully rescued the non-ripening phenotype of the tomato (Solanum lycopersicum) cr-nor mutant, while CmNAC-NORA,S did not. Our results provide insight into the molecular mechanism of climacteric and non-climacteric fruit ripening in melon.


Assuntos
Cucumis melo , Cucurbitaceae , Solanum lycopersicum , Cucumis melo/genética , Cucumis melo/metabolismo , Cucurbitaceae/genética , Cucurbitaceae/metabolismo , Etilenos , Frutas/genética , Frutas/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Solanum lycopersicum/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
10.
Small ; 17(36): e2101924, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34309199

RESUMO

Enzyme-activatable ratiometric near-infrared (NIR) fluorescent probes enabling noninvasive imaging of enzyme activity in vivo are promising for biomedical research; however, such probes with ratiometric fluorescence emissions both in NIR window under a single NIR light excitation are largely unexplored. Here, a quenched NIR fluorophore of Cy5.5 is integrated with NIR fluorescent poly[2,6-(4,4-bis-(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b']dithiophene)-alt-4,7(2,1,3-benzothiadiazole)] (PCPDTBT)-based semiconducting polymer nanoparticles (SPNs), and an αv ß3 integrin-targeting and matrix metalloproteinase-2 (MMP-2)-activatable ratiometric fluorescent probe (SPN-MMP-RGD) is developed. Under excitation at 660 nm, SPN-MMP-RGD shows "always-on" fluorescence of PCPDTBT (830 nm) and activatable fluorescence of Cy5.5 (690 nm) toward MMP-2, affording a remarkable ≈176-fold enhancement in fluorescence intensity ratio between 690 and 830 nm (I690 /I830 ) for sensitive detection of MMP-2 activity in vitro and in tumor cells. By virtue of ratiometric fluorescence imaging independently of probe's concentration, SPN-MMP-RGD can not only accurately report on MMP-2 levels regarding different tumor sizes, but also noninvasively delineate MMP-2-positive tiny gastric tumors metastasis in vivo. The authors' study reveals the potential of SPN-MMP-RGD for ratiometric fluorescence imaging of MMP-2 activity via combining two independent NIR fluorophores, which can be amenable for the design of other enzyme-activatable ratiometric NIR fluorescent probes for reliable in vivo imaging.


Assuntos
Nanopartículas , Neoplasias Gástricas , Humanos , Metaloproteinase 2 da Matriz , Imagem Óptica , Polímeros
11.
Plant Physiol ; 183(3): 1171-1183, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32321841

RESUMO

Red-fleshed watermelons (Citrullus lanatus) that accumulate lycopene in their flesh cells have been selected and domesticated from their pale-fleshed ancestors. However, the molecular basis of this trait remains poorly understood. Using map-based cloning and transgenic analysis, we identified a lycopene ß-cyclase (ClLCYB) gene that controls the flesh color of watermelon. Down-regulation of ClLCYB caused the flesh color to change from pale yellow to red, and ClLCYB overexpression in the red-fleshed line caused the flesh color to change to orange. Analysis of ClLCYB single-nucleotide polymorphisms using 211 watermelon accessions with different flesh colors revealed that two missense mutations between three haplotypes (ClLCYB red , ClLCYB white , and ClLCYB yellow ) were selected and largely fixed in domesticated watermelon. Proteins derived from these three ClLCYB haplotypes were localized in plastids to catalyze the conversion of lycopene to ß-carotene and showed similar catalytic abilities. We revealed that ClLCYB protein abundance, instead of ClLCYB transcript level, was negatively correlated with lycopene accumulation. Different amounts of ClLCYB protein degradation among the ClLCYB haplotypes were found in ClLCYB transgenic Arabidopsis (Arabidopsis thaliana) lines. After treatment with the proteasome inhibitor MG132, the concentration of ClLCYBred increased noticeably compared with other ClLCYB proteins. These results indicate that natural missense mutations within ClLCYB influence ClLCYB protein abundance and have contributed to the development of red flesh color in domesticated watermelon.


Assuntos
Citrullus/enzimologia , Domesticação , Liases Intramoleculares/metabolismo , Pigmentação , Proteínas de Plantas/metabolismo , Biocatálise , Carotenoides/metabolismo , Segregação de Cromossomos , Citrullus/genética , Cruzamentos Genéticos , Frutas/metabolismo , Genes de Plantas , Haplótipos/genética , Liases Intramoleculares/genética , Cinética , Fenótipo , Filogenia , Pigmentação/genética , Plantas Geneticamente Modificadas , Proteólise , Seleção Genética , Frações Subcelulares/metabolismo
12.
Opt Express ; 29(13): 20829-20838, 2021 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-34266163

RESUMO

In this paper, a metal-insulator-metal (MIM) waveguide structure consisting of a side-coupled rectangular cavity (SCRC), a rightward opening semi-ring cavity (ROSRC), and a bus waveguide is reported. The finite element method is used to analyze the transmission characteristics and magnetic-field distributions of the structure in detail. The structure can support triple Fano resonances, and the Fano resonances can be tuned independently by altering the geometric parameters of the structure. Moreover, the structure can be applied in refractive index sensing and biosensing. The maximum sensitivity of refractive index sensing is up to 1550.38 nm/RIU, and there is a good linear relationship between resonance wavelength and refractive index. The MIM waveguide structure has potential applications in optical on-chip nano-sensing.

13.
Analyst ; 146(6): 1865-1871, 2021 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-33480367

RESUMO

γ-Glutamyltranspeptidase (GGT) is an important aminopeptidase overexpressed in many malignant tumors, and accurate detection of its activity is useful for the diagnosis and treatment of tumors. Herein, we report a GGT-activatable ratiometric fluorescent probe (1) constructed by covalently linking an 'always-on' BODIPY fluorophore with a GGT-activatable near-infrared (NIR) fluorescent substrate. Upon interaction with GGT, the NIR fluorescence at 735 nm in probe 1 is significantly enhanced, while the fluorescence of BODIPY at 517 nm remains unchanged. Using BODIPY fluorescence as an internal standard, significantly enhanced ratiometric fluorescence between 735 nm and 517 nm could be achieved, allowing accurate detection of the activity of GGT in living subjects independent of probe concentration. We demonstrate that probe 1 is feasible for the evaluation of GGT levels in different tumor cells and differentiation of GGT-positive tumor cells from GGT-negative normal tissue cells. Moreover, probe 1 is further applied for the visualization of tumor via noninvasive ratiometric fluorescence imaging of GGT activity, which could facilitate the detection of GGT-positive tumor tissues and study of GGT-related pathological processes.


Assuntos
Neoplasias , gama-Glutamiltransferase , Corantes Fluorescentes , Humanos , Neoplasias/diagnóstico por imagem , Imagem Óptica
14.
Appl Opt ; 60(18): 5312-5319, 2021 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-34263768

RESUMO

A plasmonic metal-insulator-metal (MIM) waveguide system is proposed, which is composed of a symmetrical X-shaped resonant cavity and a bus waveguide with a baffle, and its Fano resonance and optical sensing characteristics are investigated by using the finite element method (FEM). The results show that the system allows easy implementation of up to four Fano resonances, and the maximum refractive index sensitivity and figure of merit are 1303 nm/RIU and 3113, respectively. The influences of the geometric parameters of the system on the Fano resonances are also investigated, and further the independent adjustments of the Fano resonance line shape and wavelength are realized. Moreover, when an additional X-shaped resonant cavity is added to the system, more ultrasharp Fano resonances with considerable performances are obtained, which may enhance the parallel processing capability of the system. The proposed plasmonic MIM waveguide system may have potential applications in integrated photonic devices and nanoscale optical sensing.

15.
New Phytol ; 227(6): 1858-1871, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32453446

RESUMO

Unloading sugar from sink phloem by transporters is complex and much remains to be understood about this phenomenon in the watermelon fruit. Here, we report a novel vacuolar sugar transporter (ClVST1) identified through map-based cloning and association study, whose expression in fruit phloem is associated with accumulation of sucrose (Suc) in watermelon fruit. ClVST197 knockout lines show decreased sugar content and total biomass, whereas overexpression of ClVST197 increases Suc content. Population genomic and subcellular localization analyses strongly suggest a single-base change at the coding region of ClVST197 as a major molecular event during watermelon domestication, which results in the truncation of 45 amino acids and shifts the localization of ClVST197 to plasma membranes in sweet watermelons. Molecular, biochemical and phenotypic analyses indicate that ClVST197 is a novel sugar transporter for Suc and glucose efflux and unloading. Functional characterization of ClVST1 provides a novel strategy to increase sugar sink potency during watermelon domestication.


Assuntos
Citrullus , Floema , Transporte Biológico , Citrullus/genética , Floema/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Açúcares
16.
Opt Lett ; 45(3): 754-757, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-32004302

RESUMO

In this Letter, Autler-Townes splitting and induced transparency windows are observed in a multimode microfiber knot. The microfiber knot is fabricated using tapered single-mode fiber, with the knot position located at the transition area of the tapered fiber. The spectrum, in analogy to Autler-Townes splitting, derives from the mode splitting of two high-order excited modes, which is theoretically explained by the multimode transfer matrix method. Moreover, without adding resonators, two induced transparency windows are realized with the tunable coupling coefficients and phase difference of excited knot modes. The tunable, easily fabricated, compact, and robust microfiber knot has potential applications in optical sensing, filters, slow light, and optical switching.

17.
Appl Opt ; 59(21): 6424-6430, 2020 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-32749309

RESUMO

Fano resonance is a pervasive resonance phenomenon which can be applied to high sensitivity sensing, perfect absorption, electromagnetic-induced transparency, and slow-light photonic devices. In this paper, we propose a metal-insulator-metal (MIM) waveguide structure consisting of a D-shaped cavity and a bus waveguide with a silver-air-silver barrier. The Fano resonance can be achieved by the interaction between the D-shaped cavity and the bus waveguide. The finite element method is used to analyze the transmission characteristics and magnetic-field distributions of the structure in detail. Simulation results show the Fano resonance can be adjusted by altering the geometric parameters of the MIM waveguide structure or the refractive index of the D-shaped cavity. The maximum refractive index sensitivity of the structure can reach up to 1510 nm/RIU, and there is a good linear relationship between resonance wavelength and refractive index. Since it has good sensitivity and tunability, the MIM waveguide structure can be used in bio-sensing, such as human hemoglobin detection. We show its applicability for the detection of three different human blood groups as well.


Assuntos
Hemoglobinas/análise , Fenômenos Ópticos , Humanos , Campos Magnéticos , Refratometria , Análise Espectral
18.
Plant Cell Physiol ; 60(3): 562-574, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30496548

RESUMO

Melatonin plays an important role in stress tolerance in plants. In this study, exogenous melatonin significantly alleviated the dwarf phenotype and inhibited the decrease of plant fresh weight induced by excess copper (Cu2+). Our results indicated that melatonin alleviated Cu2+ toxicity by improving Cu2+ sequestration, carbon metabolism and ROS (reactive oxygen species) scavenging, rather than by influencing the Cu2+ uptake under excess Cu2+ conditions. Transcriptome analysis showed that melatonin broadly altered gene expression under Cu2+ stress. Melatonin increased the levels of glutathione and phytochelatin to chelate excess Cu2+ and promoted cell wall trapping, thus keeping more Cu2+ in the cell wall and vacuole. Melatonin inhibited ROS production and enhanced antioxidant systems at the transcriptional level and enzyme activities, thus building a line of defense in response to excess Cu2+. The distribution of nutrient elements was recovered by melatonin which was disturbed by Cu2+. In addition, melatonin activated carbon metabolism, especially glycolysis and the pentose phosphate pathway, to generate more ATP, an intermediate for biosynthesis. Taken together, melatonin alleviated Cu2+ toxicity in cucumber via multiple mechanisms. These results will help to resolve the toxic effects of Cu2+ stress on plant growth and development. These results can be used for new strategies to solve problems associated with Cu2+ stress.


Assuntos
Cucumis sativus/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Peroxidação de Lipídeos/genética , Peroxidação de Lipídeos/fisiologia , Melatonina/metabolismo , Melatonina/farmacologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Transcriptoma/genética
19.
Opt Express ; 27(15): 20156-20164, 2019 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-31510115

RESUMO

We propose a high-temperature sensor based on a suspended-core microstructured optical fiber (SCMF). The sensor is constructed by fusion splicing a piece of SCMF between two sections of multimode fibers (MMFs) which act as light beam couplers. The multimode interference is formed by the air cladding modes and the silica core modes in the SCMF. Fast Fourier transform is adapted to filtering the raw transmission spectra of the MMF-SCMF-MMF structure. The wavelength shift of the dominant spatial frequency is monitored as the temperature varies from 50 °C to 800 °C. The sensitivities of 31.6 pm/°C and 51.6 pm/°C in the temperature range of 50 °C-450 °C and 450 °C-800 °C are respectively achieved. Taking advantage of the compact size, good stability and repeatability, easy fabrication, and low cost, this proposed high-temperature sensor has an applicable value.

20.
Phys Chem Chem Phys ; 21(22): 11810-11821, 2019 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-31115401

RESUMO

Lithium-based deep eutectic solvents (DESs) are potential and promising electrolytes for energy-storing devices such as the lithium-ion battery and supercapacitor due to their greenness, low cost, favorable stability, and ease of synthesis. LiTf2N (lithium bis(trifluoromethylsulfonyl)imide):NMA (N-methylacetamide) is a liquid due to the strong intermolecular H-bonding interaction between the H-bonding acceptor (HBA, LiTf2N) and H-bonding donor (HBD, NMA). The properties (melting point, conductivity, viscosity, etc.) of LiTf2N:NMA change with the evaporation of NMA from LiTf2N:NMA, which would further influence the performance of the energy-storing devices. The evaporation of DES should be determined by the intermolecular interactions. Here, for the first time, the dynamic process of evaporation and intermolecular interactions of the DES LiTf2N:NMA at room temperature were investigated and we find that the evaporation mechanism of the DES LiTf2N:NMA can be divided into three stages. In the first stage (before 110 min), the H-bonding interaction between O in LiTf2N and NH in NMA is disrupted before destruction of the coordinating interaction related to amide II C[double bond, length as m-dash]O and Li cation. In the second stage (from 110 min to 270 min), the change of coordinating interaction related to amide II C[double bond, length as m-dash]O and Li cation is also higher than that of the H-bonded interaction. In the third stage (after 270 min), evaporation of NMA from LiTf2N:NMA has very little influence on the environment of LiTf2N:NMA. This work provides a guide for designing DESs as electrolytes for energy-storing devices such as the lithium-ion battery and supercapacitor.

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