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1.
Zhongguo Gu Shang ; 37(7): 718-24, 2024 Jul 25.
Artigo em Chinês | MEDLINE | ID: mdl-39104075

RESUMO

OBJECTIVE: To screen the differentially expressed genes of lung metastasis of osteosarcoma by bioinformatics, and explore their functions and regulatory networks. METHODS: The data set of GSE14359 was screened from GEO database(http://www.ncbi.nlm.nih.gov/gds) and the differentially expressed gene(DEG) was identified using GEO2R online tool. Download osteosarcoma disease related miRNAs from the online HMMD database(http://www.cuilab.cn/hmdd) and then FunRich software was used to predict the target gene, intersects with DEG to obtains the target gene. The miRNA-mRNA relationship pairs were formed according to the targeted joints, then the data was imported into Cytoscape for visualization, DAVID was used to performe GO and KEGG analysis on target genes, STRING was used to construct PPI network, Cytoscape visualization, CytoHubba plug-in screening central genes and online website for expression and survival analysis. RESULTS: Total 704 DEGs were identified, consisting of 477 up-regulated genes and 227 down regulated genes. FunRich predicted 7 888 mRNAs and 343 target genes were obtained through intersection of the two. KEGG analysis showed that it was mainly involved in focal adhesion, ECM receptor interaction, TNF signal pathway, PI3K-Akt signal pathway, IL-17 signal pathway and MAPK signal pathway. Ten central genes (CCNB1, CHEK1, AURKA, DTL, RRM2, MELK, CEP55, FEN1, KPNA2, TYMS) were identified as potential key genes. Among them, CCNB1, DTL, MELK were highly correlated with poor prognosis. CONCLUSION: The key genes and functional pathways identified in this study may be helpful to understand the molecular mechanism of the occurrence and progression of lung metastases from osteosarcoma, and provide potential therapeutic targets.


Assuntos
Biologia Computacional , Neoplasias Pulmonares , Osteossarcoma , Osteossarcoma/genética , Humanos , Neoplasias Pulmonares/genética , Neoplasias Ósseas/genética , Regulação Neoplásica da Expressão Gênica , Redes Reguladoras de Genes , MicroRNAs/genética , Perfilação da Expressão Gênica
2.
FASEB J ; 38(15): e23852, 2024 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-39101942

RESUMO

Temporomandibular joint osteoarthritis (TMJOA) is a degenerative ailment that causes slow cartilage degeneration, aberrant bone remodeling, and persistent discomfort, leading to a considerable reduction in the patient's life quality. Current treatment options for TMJOA have limited efficacy. This investigation aimed to explore a potential strategy for halting or reversing the progression of TMJOA through the utilization of exosomes (EXOs) derived from urine-derived stem cells (USCs). The USC-EXOs were obtained through microfiltration and ultrafiltration techniques, followed by their characterization using particle size analysis, electron microscopy, and immunoblotting. Subsequently, an in vivo model of TMJOA induced by mechanical force was established. To assess the changes in the cartilage of TMJOA treated with USC-EXOs, we performed histology analysis using hematoxylin-eosin staining, immunohistochemistry, and histological scoring. Our findings indicate that the utilization of USC-EXOs yields substantial reductions in TMJOA, while concurrently enhancing the structural integrity and smoothness of the compromised condylar cartilage surface. Additionally, USC-EXOs exhibit inhibitory effects on osteoclastogenic activity within the subchondral bone layer of the condylar cartilage, as well as attenuated apoptosis in the rat TMJ in response to mechanical injury. In conclusion, USC-EXOs hold considerable promise as a potential therapeutic intervention for TMJOA.


Assuntos
Exossomos , Osteoartrite , Articulação Temporomandibular , Exossomos/metabolismo , Animais , Osteoartrite/terapia , Osteoartrite/patologia , Osteoartrite/metabolismo , Ratos , Masculino , Humanos , Articulação Temporomandibular/metabolismo , Articulação Temporomandibular/patologia , Células-Tronco/citologia , Células-Tronco/metabolismo , Ratos Sprague-Dawley , Urina/citologia , Transtornos da Articulação Temporomandibular/terapia , Transtornos da Articulação Temporomandibular/metabolismo , Transtornos da Articulação Temporomandibular/patologia , Feminino , Cartilagem Articular/patologia , Cartilagem Articular/metabolismo
3.
Opt Lett ; 49(17): 4799-4802, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-39207967

RESUMO

High-power laser diodes with a stable wavelength and narrow linewidth are crucial for many applications. In this study, we introduce a first-order distributed feedback (DFB) grating into an asymmetric large-cavity laser diode operating around 940 nm. This design maintains high output power and offers a wide temperature locking range. The nearly sinusoidal shape first-order grating is fabricated by ultraviolet (UV) nanoimprint lithography, inductively coupled plasma (ICP) dry etching, and wet polishing. At a heat sink temperature of 25°C, the DFB laser diode, with a 200 µm stripe width and 4 mm cavity length, achieves a maximum output power of 24.8 W and a full width at half maximum (FWHM) of 0.4 nm under continuous-wave (CW) conditions. The maximum slope efficiency is calculated to be 1.04 W/A. At an output power of 10.7 W, the device reaches a peak wall-plug efficiency of 56%. Under quasi-continuous operation at 20 A, the laser output spectrum remains locked to the DFB grating over a temperature range from -10°C to 110°C, with a temperature coefficient of 0.062 nm/°C.

4.
Int J Mol Sci ; 25(16)2024 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-39201712

RESUMO

Nitrogen (N) is essential for sugar beet (Beta vulgaris L.), a highly N-demanding sugar crop. This study investigated the morphological, subcellular, and microRNA-regulated responses of sugar beet roots to low N (LN) stress (0.5 mmol/L N) to better understand the N perception, uptake, and utilization in this species. The results showed that LN led to decreased dry weight of roots, N accumulation, and N dry matter production efficiency, along with damage to cell walls and membranes and a reduction in organelle numbers (particularly mitochondria). Meanwhile, there was an increase in root length (7.2%) and branch numbers (29.2%) and a decrease in root surface area (6.14%) and root volume (6.23%) in sugar beet after 7 d of LN exposure compared to the control (5 mmol/L N). Transcriptomics analysis was confirmed by qRT-PCR for 6 randomly selected microRNAs, and we identified 22 differentially expressed microRNAs (DEMs) in beet root under LN treatment. They were primarily enriched in functions related to binding (1125), ion binding (641), intracellular (437) and intracellular parts (428), and organelles (350) and associated with starch and sucrose metabolism, tyrosine metabolism, pyrimidine metabolism, amino sugar and nucleotide sugar metabolism, and isoquinoline alkaloid biosynthesis, as indicated by the GO and KEGG analyses. Among them, the upregulated miR156a, with conserved sequences, was identified as a key DEM that potentially targets and regulates squamosa promoter-binding-like proteins (SPLs, 104889216 and 104897537) through the microRNA-mRNA network. Overexpression of miR156a (MIR) promoted root growth in transgenic Arabidopsis, increasing the length, surface area, and volume. In contrast, silencing miR156a (STTM) had the opposite effect. Notably, the fresh root weight decreased by 45.6% in STTM lines, while it increased by 27.4% in MIR lines, compared to the wild type (WT). It can be inferred that microRNAs, especially miR156, play crucial roles in sugar beet root's development and acclimation to LN conditions. They likely facilitate active responses to N deficiency through network regulation, enabling beet roots to take up nutrients from the environment and sustain their vital life processes.


Assuntos
Beta vulgaris , Regulação da Expressão Gênica de Plantas , MicroRNAs , Nitrogênio , Raízes de Plantas , Beta vulgaris/genética , Beta vulgaris/crescimento & desenvolvimento , Beta vulgaris/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , Raízes de Plantas/metabolismo , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Nitrogênio/metabolismo , Nitrogênio/deficiência , Aclimatação/genética , Perfilação da Expressão Gênica
5.
J Integr Plant Biol ; 2024 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-38990128

RESUMO

Light and gravity coordinately regulate the directional growth of plants. Arabidopsis Gravitropic in the Light 1 (GIL1) inhibits the negative gravitropism of hypocotyls in red and far-red light, but the underlying molecular mechanisms remain elusive. Our study found that GIL1 is a plasma membrane-localized protein. In endodermal cells of the upper part of hypocotyls, GIL1 controls the negative gravitropism of hypocotyls. GIL1 directly interacts with PIN3 and inhibits the auxin transport activity of PIN3. Mutation of PIN3 suppresses the abnormal gravitropic response of gil1 mutant. The GIL1 protein is unstable in darkness but it is stabilized by red and far-red light. Together, our data suggest that light-stabilized GIL1 inhibits the negative gravitropism of hypocotyls by suppressing the activity of the auxin transporter PIN3, thereby enhancing the emergence of young seedlings from the soil.

6.
J Am Chem Soc ; 146(28): 18879-18885, 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-38968417

RESUMO

Chiral secondary alkyl amines with a vicinal quaternary stereocenter are undoubtedly important and ubiquitous subunits in natural products and pharmaceuticals. However, their asymmetric synthesis remains a formidable challenge. Herein, we merge the ring-opening 1,2-metallate shift with iridium-catalyzed enantioselective C(sp3)-H borylation of aziridines to deliver these frameworks with high enantioselectivities. We also demonstrated the synthetic application by downstream transformations, including the total synthesis of two Amaryllidaceae alkaloids, (-)-crinane and (+)-mesmebrane.

7.
J Integr Plant Biol ; 2024 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-39023402

RESUMO

Although green light (GL) is located in the middle of the visible light spectrum and regulates a series of plant developmental processes, the mechanism by which it regulates seedling development is largely unknown. In this study, we demonstrated that GL promotes atypical photomorphogenesis in Arabidopsis thaliana via the dual regulations of phytochrome B (phyB) and phyA. Although the Pr-to-Pfr conversion rates of phyB and phyA under GL were lower than those under red light (RL) in a fluence rate-dependent and time-dependent manner, long-term treatment with GL induced high Pfr/Pr ratios of phyB and phyA. Moreover, GL induced the formation of numerous small phyB photobodies in the nucleus, resulting in atypical photomorphogenesis, with smaller cotyledon opening angles and longer hypocotyls in seedlings compared to RL. The abundance of phyA significantly decreased after short- and long-term GL treatments. We determined that four major PHYTOCHROME-INTERACTING FACTORs (PIFs: PIF1, PIF3, PIF4, and PIF5) act downstream of phyB in GL-mediated cotyledon opening. In addition, GL plays opposite roles in regulating different PIFs. For example, under continuous GL, the protein levels of all PIFs decreased, whereas the transcript levels of PIF4 and PIF5 strongly increased compared with dark treatment. Taken together, our work provides a detailed molecular framework for understanding the role of the antagonistic regulations of phyB and phyA in GL-mediated atypical photomorphogenesis.

8.
Biomark Med ; 18(8): 373-383, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39041842

RESUMO

Aim: This retrospective clinical study was designed to examine the predictive value of thromboelastography (TEG) combined with coagulation function for venous thromboembolism (VTE) in hospitalized patients with cancer. Materials & methods: Among 215 patients admitted between May 2020 and January 2022, 39 (18.14%) were diagnosed with VTE during hospitalization. Results: Significant differences were found in D-dimer, ATIII and TEG parameters (maximum amplitude and coagulation index) between VTE-positive and VTE-negative patients (p < 0.05). Multivariate analysis revealed tumor node metastasis stage, concomitant infection, smoking history and D-dimer as independently associated with VTE. The constructed model and D-dimer areas under the curve were 0.809 and 0.764, respectively. Conclusion: TEG parameters were not significantly predictive indicators for VTE, with D-dimer remaining a key predictor.


[Box: see text].


Assuntos
Produtos de Degradação da Fibrina e do Fibrinogênio , Neoplasias , Tromboelastografia , Tromboembolia Venosa , Humanos , Tromboembolia Venosa/sangue , Tromboembolia Venosa/etiologia , Tromboembolia Venosa/diagnóstico , Masculino , Feminino , Pessoa de Meia-Idade , Neoplasias/complicações , Neoplasias/sangue , Estudos Retrospectivos , Idoso , Produtos de Degradação da Fibrina e do Fibrinogênio/metabolismo , Produtos de Degradação da Fibrina e do Fibrinogênio/análise , Fatores de Risco , Fatores de Coagulação Sanguínea/metabolismo , Fatores de Coagulação Sanguínea/análise , Adulto
9.
Nat Genet ; 56(8): 1750-1761, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38977857

RESUMO

To decipher the genetic diversity within the cucurbit genus Citrullus, we generated telomere-to-telomere (T2T) assemblies of 27 distinct genotypes, encompassing all seven Citrullus species. This T2T super-pangenome has expanded the previously published reference genome, T2T-G42, by adding 399.2 Mb and 11,225 genes. Comparative analysis has unveiled gene variants and structural variations (SVs), shedding light on watermelon evolution and domestication processes that enhanced attributes such as bitterness and sugar content while compromising disease resistance. Multidisease-resistant loci from Citrullus amarus and Citrullus mucosospermus were successfully introduced into cultivated Citrullus lanatus. The SVs identified in C. lanatus have not only been inherited from cordophanus but also from C. mucosospermus, suggesting additional ancestors beyond cordophanus in the lineage of cultivated watermelon. Our investigation substantially improves the comprehension of watermelon genome diversity, furnishing comprehensive reference genomes for all Citrullus species. This advancement aids in the exploration and genetic enhancement of watermelon using its wild relatives.


Assuntos
Citrullus , Genoma de Planta , Telômero , Citrullus/genética , Telômero/genética , Melhoramento Vegetal/métodos , Variação Genética , Filogenia , Domesticação , Genótipo
10.
Nat Commun ; 15(1): 5130, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38879536

RESUMO

Intron retention (IR) is the most common alternative splicing event in Arabidopsis. An increasing number of studies have demonstrated the major role of IR in gene expression regulation. The impacts of IR on plant growth and development and response to environments remain underexplored. Here, we found that IR functions directly in gene expression regulation on a genome-wide scale through the detainment of intron-retained transcripts (IRTs) in the nucleus. Nuclear-retained IRTs can be kept away from translation through this mechanism. COP1-dependent light modulation of the IRTs of light signaling genes, such as PIF4, RVE1, and ABA3, contribute to seedling morphological development in response to changing light conditions. Furthermore, light-induced IR changes are under the control of the spliceosome, and in part through COP1-dependent ubiquitination and degradation of DCS1, a plant-specific spliceosomal component. Our data suggest that light regulates the activity of the spliceosome and the consequent IRT nucleus detainment to modulate photomorphogenesis through COP1.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Núcleo Celular , Regulação da Expressão Gênica de Plantas , Íntrons , Luz , Spliceossomos , Ubiquitina-Proteína Ligases , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/efeitos da radiação , Arabidopsis/metabolismo , Íntrons/genética , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Spliceossomos/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitina-Proteína Ligases/genética , Núcleo Celular/metabolismo , Plântula/crescimento & desenvolvimento , Plântula/genética , Plântula/efeitos da radiação , Plântula/metabolismo , Processamento Alternativo , Ubiquitinação
11.
Nature ; 632(8025): 576-584, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38866052

RESUMO

Increasing planting density is a key strategy for enhancing maize yields1-3. An ideotype for dense planting requires a 'smart canopy' with leaf angles at different canopy layers differentially optimized to maximize light interception and photosynthesis4-6, among other features. Here we identified leaf angle architecture of smart canopy 1 (lac1), a natural mutant with upright upper leaves, less erect middle leaves and relatively flat lower leaves. lac1 has improved photosynthetic capacity and attenuated responses to shade under dense planting. lac1 encodes a brassinosteroid C-22 hydroxylase that predominantly regulates upper leaf angle. Phytochrome A photoreceptors accumulate in shade and interact with the transcription factor RAVL1 to promote its degradation via the 26S proteasome, thereby inhibiting activation of lac1 by RAVL1 and decreasing brassinosteroid levels. This ultimately decreases upper leaf angle in dense fields. Large-scale field trials demonstrate that lac1 boosts maize yields under high planting densities. To quickly introduce lac1 into breeding germplasm, we transformed a haploid inducer and recovered homozygous lac1 edits from 20 diverse inbred lines. The tested doubled haploids uniformly acquired smart-canopy-like plant architecture. We provide an important target and an accelerated strategy for developing high-density-tolerant cultivars, with lac1 serving as a genetic chassis for further engineering of a smart canopy in maize.


Assuntos
Produção Agrícola , Fotossíntese , Folhas de Planta , Zea mays , Brassinosteroides/metabolismo , Produção Agrícola/métodos , Escuridão , Haploidia , Homozigoto , Luz , Mutação , Fotossíntese/efeitos da radiação , Fitocromo A/metabolismo , Melhoramento Vegetal , Folhas de Planta/anatomia & histologia , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Folhas de Planta/efeitos da radiação , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Complexo de Endopeptidases do Proteassoma/metabolismo , Fatores de Transcrição/metabolismo , Zea mays/anatomia & histologia , Zea mays/enzimologia , Zea mays/genética , Zea mays/crescimento & desenvolvimento , Zea mays/efeitos da radiação
12.
Opt Lett ; 49(12): 3448-3451, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38875642

RESUMO

High-power semiconductor lasers with stabilized wavelengths are recognized as exemplary pumping sources for solid-state lasers. This study introduces distributed feedback (DFB) laser diode arrays designed to maintain an extensive temperature locking range. We report experimentally on high-power 808 nm DFB laser diode arrays. The first-order sinusoidal grating was fabricated using nanoimprint lithography, succeeded by inductively coupled plasma (ICP) dry etching and subsequent wet polishing. These 808 nm DFB laser diode arrays have demonstrated a measured output power of 134 W under a pulsed current of 150 A, with the heat sink temperature maintained at 25°C. The slope efficiency was determined to be 1.1 W/A. At a current of 150 A, the laser operated with a narrow spectral width over a wide temperature range, extending from -30 to 90°C, with a temperature drift coefficient of 0.0595 nm/K.

13.
Nat Plants ; 10(5): 798-814, 2024 05.
Artigo em Inglês | MEDLINE | ID: mdl-38714768

RESUMO

Phytochrome A (phyA) is the plant far-red (FR) light photoreceptor and plays an essential role in regulating photomorphogenic development in FR-rich conditions, such as canopy shade. It has long been observed that phyA is a phosphoprotein in vivo; however, the protein kinases that could phosphorylate phyA remain largely unknown. Here we show that a small protein kinase family, consisting of four members named PHOTOREGULATORY PROTEIN KINASES (PPKs) (also known as MUT9-LIKE KINASES), directly phosphorylate phyA in vitro and in vivo. In addition, TANDEM ZINC-FINGER/PLUS3 (TZP), a recently characterized phyA-interacting protein required for in vivo phosphorylation of phyA, is also directly phosphorylated by PPKs. We reveal that TZP contains two intrinsically disordered regions in its amino-terminal domain that undergo liquid-liquid phase separation (LLPS) upon light exposure. The LLPS of TZP promotes colocalization and interaction between PPKs and phyA, thus facilitating PPK-mediated phosphorylation of phyA in FR light. Our study identifies PPKs as a class of protein kinases mediating the phosphorylation of phyA and demonstrates that the LLPS of TZP contributes significantly to more production of the phosphorylated phyA form in FR light.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Fitocromo A , Fosforilação , Fitocromo A/metabolismo , Fitocromo A/genética , Arabidopsis/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas Quinases/metabolismo , Proteínas Quinases/genética , Separação de Fases
14.
Plant Biotechnol J ; 22(9): 2596-2611, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38762905

RESUMO

Higher-order chromatin structure is critical for regulation of gene expression. In plants, light profoundly affects the morphogenesis of emerging seedlings as well as global gene expression to ensure optimal adaptation to environmental conditions. However, the changes and functional significance of chromatin organization in response to light during seedling development are not well documented. We constructed Hi-C contact maps for the cotyledon, apical hook and hypocotyl of soybean subjected to dark and light conditions. The resulting high-resolution Hi-C contact maps identified chromosome territories, A/B compartments, A/B sub-compartments, TADs (Topologically Associated Domains) and chromatin loops in each organ. We observed increased chromatin compaction under light and we found that domains that switched from B sub-compartments in darkness to A sub-compartments under light contained genes that were activated during photomorphogenesis. At the local scale, we identified a group of TADs constructed by gene clusters consisting of different numbers of Small Auxin-Upregulated RNAs (SAURs), which exhibited strict co-expression in the hook and hypocotyl in response to light stimulation. In the hypocotyl, RNA polymerase II (RNAPII) regulated the transcription of a SAURs cluster under light via TAD condensation. Our results suggest that the 3D genome is involved in the regulation of light-related gene expression in a tissue-specific manner.


Assuntos
Cromatina , Regulação da Expressão Gênica de Plantas , Glycine max , Hipocótilo , Luz , Glycine max/genética , Glycine max/metabolismo , Glycine max/crescimento & desenvolvimento , Cromatina/metabolismo , Cromatina/genética , Hipocótilo/genética , Hipocótilo/crescimento & desenvolvimento , Hipocótilo/metabolismo , Cotilédone/genética , Cotilédone/crescimento & desenvolvimento , Cotilédone/metabolismo , Cotilédone/efeitos da radiação , Plântula/genética , Plântula/crescimento & desenvolvimento , Plântula/efeitos da radiação
15.
Plant Commun ; 5(8): 100979, 2024 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-38794796

RESUMO

Peanut (Arachis hypogaea L.) is an important leguminous oil and economic crop that produces flowers aboveground and fruits belowground. Subterranean fruit-pod development, which significantly affects peanut production, involves complex molecular mechanisms that likely require the coordinated regulation of multiple genes in different tissues. To investigate the molecular mechanisms that underlie peanut fruit-pod development, we characterized the anatomical features of early fruit-pod development and integrated single-nucleus RNA-sequencing (snRNA-seq) and single-nucleus assay for transposase-accessible chromatin with sequencing (snATAC-seq) data at the single-cell level. We identified distinct cell types, such as meristem, embryo, vascular tissue, cuticular layer, and stele cells within the shell wall. These specific cell types were used to examine potential molecular changes unique to each cell type during pivotal stages of fruit-pod development. snRNA-seq analyses of differentially expressed genes revealed cell-type-specific insights that were not previously obtainable from transcriptome analyses of bulk RNA. For instance, we identified MADS-box genes that contributes to the formation of parenchyma cells and gravity-related genes that are present in the vascular cells, indicating an essential role for the vascular cells in peg gravitropism. Overall, our single-nucleus analysis provides comprehensive and novel information on specific cell types, gene expression, and chromatin accessibility during the early stages of fruit-pod development. This information will enhance our understanding of the mechanisms that underlie fruit-pod development in peanut and contribute to efforts aimed at improving peanut production.


Assuntos
Arachis , Frutas , Arachis/genética , Arachis/crescimento & desenvolvimento , Frutas/genética , Frutas/crescimento & desenvolvimento , Análise de Sequência de RNA , Regulação da Expressão Gênica de Plantas , Núcleo Celular/genética , Núcleo Celular/metabolismo , RNA de Plantas/genética , Análise de Célula Única
16.
Opt Lett ; 49(10): 2689-2692, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38748137

RESUMO

To enhance the integration and practical applicability of the Raman detection system, silver nanocubes (Ag NCs) were synthesized using a polyol method. A liquid-liquid interface approach was employed to transfer a monolayer of Ag NCs "film" onto a SiO2 substrate, resulting in the fabrication of a highly sensitive and uniform surface-enhanced Raman scattering (SERS) substrate denoted as "Ag NCs@SiO2." The electromagnetic field distribution of various dimers on the Ag NCs@SiO2 was analyzed using finite difference time domain (FDTD) software. The results reveal that the electromagnetic enhancement effect is most pronounced in cube-cube dimers, indicating that Ag NCs exhibit superior localized surface plasmon resonance (LSPR) response due to their well-defined geometric regularity and sharp geometric angles. For Rhodamine 6G (R6G) probe molecules, the Ag NCs@SiO2 shows ultrahigh sensitivity, with a limit of detection (LOD) of 10-12 mol/L, and the enhancement factor (EF) can reach 1.4 × 1010. The relative standard deviation (RSD) at the main characteristic peaks is below 10%, demonstrating good consistency in substrate performance. In addition, the Ag NCs@SiO2 modified with hexanethiol exhibits high sensitivity, uniformity, and repeatability in detecting for pyrene, with the LOD of 10-8 mol/L and a minimum RSD of 6.09% at the main characteristic peak, and effective recognition capabilities for pyrene and anthracene in mixed solutions. Finally, chemisorption and physisorption strategies were prepared in optofluidic channels and experimentally compared, enabling real-time detection of the pyrene solution. This method can achieve a rapid detection and precise differentiation of polycyclic aromatic hydrocarbons in a water pollutant.

17.
Nat Commun ; 15(1): 4295, 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38769327

RESUMO

Chili pepper (Capsicum) is known for its unique fruit pungency due to the presence of capsaicinoids. The evolutionary history of capsaicinoid biosynthesis and the mechanism of their tissue specificity remain obscure due to the lack of high-quality Capsicum genomes. Here, we report two telomere-to-telomere (T2T) gap-free genomes of C. annuum and its wild nonpungent relative C. rhomboideum to investigate the evolution of fruit pungency in chili peppers. We precisely delineate Capsicum centromeres, which lack high-copy tandem repeats but are extensively invaded by CRM retrotransposons. Through phylogenomic analyses, we estimate the evolutionary timing of capsaicinoid biosynthesis. We reveal disrupted coding and regulatory regions of key biosynthesis genes in nonpungent species. We also find conserved placenta-specific accessible chromatin regions, which likely allow for tissue-specific biosynthetic gene coregulation and capsaicinoid accumulation. These T2T genomic resources will accelerate chili pepper genetic improvement and help to understand Capsicum genome evolution.


Assuntos
Capsaicina , Capsicum , Evolução Molecular , Genoma de Planta , Filogenia , Telômero , Capsicum/genética , Capsicum/metabolismo , Capsaicina/metabolismo , Telômero/genética , Telômero/metabolismo , Frutas/genética , Frutas/metabolismo , Retroelementos/genética , Regulação da Expressão Gênica de Plantas
18.
J Am Chem Soc ; 146(20): 14357-14367, 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38726589

RESUMO

Introducing dynamic behavior into periodic frameworks has borne fruit in the form of flexible porous crystals. The detailed molecular design of frameworks in order to control their collective dynamics is of particular interest, for example, to achieve stimulus-induced behavior. Herein, by varying the degree of rigidity of ditopic pillar linkers, two isostructural flexible metal-organic frameworks (MOFs) with common rigid supermolecular building bilayers were constructed. The subtle substitution of single (in bibenzyl-4,4'-dicarboxylic acid; H2BBDC) with double (in 4,4'-stilbenedicarboxylic acid; H2SDC) C-C bonds in pillared linkers led to markedly different flexible behavior of these two MOFs. Upon the removal of guest molecules, both frameworks clearly show reversible single-crystal-to-single-crystal transformations involving the cis-trans conformation change and a resulting swing of the corresponding pillar linkers, which gives rise to Flex-Cd-MOF-1a and Flex-Cd-MOF-2a, respectively. Strikingly, a more favorable gas-induced dynamic behavior in Flex-Cd-MOF-2a was verified in detail by stepwise C3H6/C3H8 sorption isotherms and the corresponding in situ powder X-ray diffraction experiments. These insights are strongly supported by molecular modeling studies on the sorption mechanism that explores the sorption landscape. Furthermore, a consistency between the macroscopic elasticity and microscopic flexibility of Flex-Cd-MOF-2 was observed. This work fuels a growing interest in developing MOFs with desired chemomechanical functions and presents detailed insights into the origins of flexible MOFs.

19.
J Org Chem ; 89(11): 7982-7990, 2024 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-38805363

RESUMO

The synthesis of monofluorinated heterocyclic compounds by C-H activation combined with defluorination is useful. Studies on the reaction mechanism and selectivity have shown that these processes play a positive role in promoting the development of monofluorinated reactions. Density functional theory (DFT) calculations were performed to investigate the mechanism and selectivity of Ru(II)-catalyzed 2-arylbenzimidazole with trifluoromethyl diazo. DFT calculations showed that C-H activation occurs through a concerted metalation/deprotonation (CMD) mechanism. After that, deprotonation and defluorinative cyclization are assisted by acetate and trifluoroethanol (TFE). Further mechanistic insights through noncovalent interaction (NCI) analysis were also obtained to elucidate the origin of the selectivity in the defluorination process.

20.
Chem Asian J ; 19(12): e202400184, 2024 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-38628038

RESUMO

We reported a chiral oxamide-phosphine ligand (COAP-Ph)-Pd-catalyzed asymmetric [3+2] cycloaddition reaction between vinyl cyclopropane compounds derived from 1,3-indanedione and 2-vinylcyclopropane-1,1-dicarboxylates with cyclic sulfonyl 1-azadienes. The corresponding reactions provided a series of enantiomerically active spiro cyclopentane-indandione and cyclopentane structures bearing three consecutive stereogenic centers in good yields with good diastereo- and enantioselectivity. The COAP-Pd complex serves not only to promote generation of chiral π-allyl-palladium intermediates and induce the asymmetry of the reaction, but also depress the background reaction.

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