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1.
Nat Mater ; 23(6): 782-789, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38491147

RESUMO

Coupling of spin and charge currents to structural chirality in non-magnetic materials, known as chirality-induced spin selectivity, is promising for application in spintronic devices at room temperature. Although the chirality-induced spin selectivity effect has been identified in various chiral materials, its Onsager reciprocal process, the inverse chirality-induced spin selectivity effect, remains unexplored. Here we report the observation of the inverse chirality-induced spin selectivity effect in chiral assemblies of π-conjugated polymers. Using spin-pumping techniques, the inverse chirality-induced spin selectivity effect enables quantification of the magnitude of the longitudinal spin-to-charge conversion driven by chirality-induced spin selectivity in different chiral polymers. By widely tuning conductivities and supramolecular chiral structures via a printing method, we found a very long spin relaxation time of up to several nanoseconds parallel to the chiral axis. Our demonstration of the inverse chirality-induced spin selectivity effect suggests possibilities for elucidating the puzzling interplay between spin and chirality, and opens a route for spintronic applications using printable chiral assemblies.

2.
Genomics ; 116(5): 110935, 2024 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-39243912

RESUMO

BACKGROUND: Santalum album L. is an evergreen tree which is mainly distributes throughout tropical and temperate regions. And it has a great medicinal and economic value. RESULTS: In this study, the complete mitochondrial genome of S. album were assembled and annotated, which could be descried by a complex branched structure consisting of three contigs. The lengths of these three contigs are 165,122 bp, 93,430 bp and 92,491 bp. We annotated 34 genes coding for proteins (PCGs), 26 tRNA genes, and 4 rRNA genes. The analysis of repeated elements shows that there are 89 SSRs and 242 pairs of dispersed repeats in S. album mitochondrial genome. Also we found 20 MTPTs among the chloroplast and mitochondria. The 20 MTPTs sequences span a combined length of 22,353 bp, making up 15.52 % of the plastome, 6.37 % of the mitochondrial genome. Additionally, by using the Deepred-mt tool, we found 628 RNA editing sites in 34 PCGs. Moreover, significant genomic rearrangement is observed between S. album and its associated mitochondrial genomes. Finally, based on mitochondrial genome PCGs, we deduced the phylogenetic ties between S. album and other angiosperms. CONCLUSIONS: We reported the mitochondrial genome from Santalales for the first time, which provides a crucial genetic resource for our study of the evolution of mitochondrial genome.

3.
J Am Chem Soc ; 146(1): 1109-1121, 2024 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-38141046

RESUMO

The energy dissipative features of hydrogen bonds under conditions of mechanical strain have provided an ongoing incentive to explore hydrogen bonding units for the purpose of controlling and customizing the mechanical properties of polymeric materials. However, there remains a need for hydrogen bond units that (1) possess directionality, (2) provide selectivity, (3) dissipate energy effectively, and (4) can be incorporated readily into polymeric materials to regulate their mechanical properties. Here, we report mechanically interlocked hydrogen bond units that incorporate multiple hydrogen bonds within a [2]catenane structure. The conformational flexibility and associated spatial folding characteristics of the [2]catenane units allow for molecular scale motion under external stress, while the interlocked structure serves as a pivot that maintains the directionality and selectivity of the resultant hydrogen bonding units. When incorporated into polymers, these interlocked hydrogen bond motifs serve to strengthen and toughen the resulting materials. This study not only presents a novel hydrogen bond unit for creating polymeric materials with improved mechanical properties but also underscores the unique opportunities that mechanically interlocked hydrogen bond structures may provide across a diverse range of applications.

4.
Int J Cancer ; 154(6): 1111-1123, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-37842828

RESUMO

Effective screening and early detection are critical to improve the prognosis of gastric cancer (GC). Our study aims to explore noninvasive multianalytical biomarkers and construct integrative models for preliminary risk assessment and GC detection. Whole genomewide methylation marker discovery was conducted with CpG tandems target amplification (CTTA) in cfDNA from large asymptomatic screening participants in a high-risk area of GC. The methylation and mutation candidates were validated simultaneously using one plasma from patients at various gastric lesion stages by multiplex profiling with Mutation Capsule Plus (MCP). Helicobacter pylori specific antibodies were detected with a recomLine assay. Integrated models were constructed and validated by the combination of multianalytical biomarkers. A total of 146 and 120 novel methylation markers were found in CpG islands and promoter regions across the genome with CTTA. The methylation markers together with the candidate mutations were validated with MCP and used to establish a 133-methylation-marker panel for risk assessment of suspicious precancerous lesions and GC cases and a 49-methylation-marker panel as well as a 144-amplicon-mutation panel for GC detection. An integrated model comprising both methylation and specific antibody panels performed better for risk assessment than a traditional model (AUC, 0.83 and 0.63, P < .001). A second model for GC detection integrating methylation and mutation panels also outperformed the traditional model (AUC, 0.82 and 0.68, P = .005). Our study established methylation, mutation and H. pylori-specific antibody panels and constructed two integrated models for risk assessment and GC screening. Our findings provide new insights for a more precise GC screening strategy in the future.


Assuntos
Infecções por Helicobacter , Helicobacter pylori , Neoplasias Gástricas , Humanos , Neoplasias Gástricas/diagnóstico , Neoplasias Gástricas/genética , Neoplasias Gástricas/patologia , Metilação de DNA , Detecção Precoce de Câncer , Biomarcadores , Medição de Risco , Helicobacter pylori/genética , Biomarcadores Tumorais/genética , Ilhas de CpG , Infecções por Helicobacter/diagnóstico , Infecções por Helicobacter/genética , Infecções por Helicobacter/patologia
5.
Anal Chem ; 96(16): 6444-6449, 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38597812

RESUMO

As two mainstream ionic detection techniques, ionic current rectification (ICR) suffers from large fluctuations in trace level detection, while resistive-pulse sensing (RPS) encounters easy clogs in high-concentration detection. By rationally matching the nanopore size with the DNA tetrahedron (TDN), this work bridges the two techniques to achieve reliable detection with wide linearity. As a representative analyte, miRNA-10b could specifically combine with and release TDN from the interior wall, which thus induced the simultaneous generation of distinct ICR and RPS signals. The ICR signals could be attributed to the balance between the effective orifice and surface charge density of the inner wall, while the RPS signals were induced by the complex of miRNA-10b and TDN passing through the nanopore. Such an operation contributed to a wide detection range of 1 fM-1 nM with a good linearity. The feasibility of this method is also validated in single-cell and real plasma detection.

6.
Small ; 20(13): e2307067, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37972263

RESUMO

This work proposes the concept of single-cell microRNA (miR) therapy and proof-of-concept by engineering a nanopipette for high-precision miR-21-targeted therapy in a single HeLa cell with sensitive photoelectrochemical (PEC) feedback. Targeting the representative oncogenic miR-21, the as-functionalized nanopipette permits direct intracellular drug administration with precisely controllable dosages, and the corresponding therapeutic effects can be sensitively transduced by a PEC sensing interface that selectively responds to the indicator level of cytosolic caspase-3. The experimental results reveal that injection of ca. 4.4 × 10-20 mol miR-21 inhibitor, i.e., 26488 copies, can cause the obvious therapeutic action in the targeted cell. This work features a solution to obtain the accurate knowledge of how a certain miR-drug with specific dosages treats the cells and thus provides an insight into futuristic high-precision clinical miR therapy using personalized medicine, provided that the prerequisite single-cell experiments are courses of personalized customization.


Assuntos
MicroRNAs , Humanos , Células HeLa , Retroalimentação , Medicina de Precisão
7.
Am Heart J ; 277: 58-65, 2024 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38942221

RESUMO

BACKGROUND: It is currently uncertain whether the combination of a proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor and high-intensity statin treatment can effectively reduce cardiovascular events in patients with acute coronary syndrome (ACS) who have undergone percutaneous coronary intervention (PCI) for culprit lesions. METHODS: This study protocol describes a double-blind, randomized, placebo-controlled, multicenter study aiming to investigate the efficacy and safety of combining a PCSK9 inhibitor with high-intensity statin therapy in patients with ACS following PCI. A total of 1,212 patients with ACS and multiple lesions will be enrolled and randomly assigned to receive either PCSK9 inhibitor plus high-intensity statin therapy or high-intensity statin monotherapy. The randomization process will be stratified by sites, diabetes, initial presentation and use of stable (≥4 weeks) statin treatment at presentation. PCSK 9 inhibitor or its placebo is injected within 4 hours after PCI for the culprit lesion. The primary endpoint is the composite of cardiovascular death, myocardial infarction, stroke, re-hospitalization due to ACS or heart failure, or any ischemia-driven coronary revascularization at 1-year follow-up between 2 groups. Safety endpoints mean PCSK 9 inhibitor and statin intolerance. CONCLUSION: The SHAWN study has been specifically designed to evaluate the effectiveness and safety of adding a PCSK9 inhibitor to high-intensity statin therapy in patients who have experienced ACS following PCI. The primary objective of this study is to generate new evidence regarding the potential benefits of combining a PCSK9 inhibitor with high-intensity statin treatment in reducing cardiovascular events among these patients.


Assuntos
Síndrome Coronariana Aguda , Quimioterapia Combinada , Inibidores de Hidroximetilglutaril-CoA Redutases , Inibidores de PCSK9 , Intervenção Coronária Percutânea , Humanos , Síndrome Coronariana Aguda/terapia , Intervenção Coronária Percutânea/métodos , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Inibidores de Hidroximetilglutaril-CoA Redutases/administração & dosagem , Método Duplo-Cego , Masculino , Feminino , Pessoa de Meia-Idade , Anticorpos Monoclonais Humanizados/uso terapêutico , Anticorpos Monoclonais Humanizados/administração & dosagem , Idoso , Infarto do Miocárdio/prevenção & controle , Infarto do Miocárdio/epidemiologia , Resultado do Tratamento , Pró-Proteína Convertase 9
8.
Histochem Cell Biol ; 2024 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-39207519

RESUMO

Sialadenitis is a prevalent salivary gland disease resulting in decreased salivary flow rate. To date, little is known about the exact changes and mechanism of ductal cells in sialadenitis. This study aims to establish an efficient method to identify and isolate ductal cells, thereby facilitating further research on this specific cell type. Immunofluorescence for cytokeratin 13 and cytokeratin 19 was conducted in salivary glands to confirm their specificity as ductal cell markers. The dissected ducts were assessed through PCR and Western blot of cytokeratin 19 and digested by dispase and collagenase. The functionality of the isolated ductal cells was determined by measuring intracellular calcium. Cytokeratin 19 and cytokeratin 13 were expressed in all segments of human ducts. Cytokeratin 19 was limited to ducts excluding granular convoluted tubules in rat and mouse. The purities of the obtained ductal cells were approximately 98% in humans and 93% in rats. Furthermore, intracellular free calcium increased with time and concentration of carbachol treatment. Cytokeratin 19 serves as a dependable marker for identifying ductal cells in salivary glands, except for granular convoluted tubules. Moreover, we have successfully developed an efficient method for isolating ductal cells from salivary glands.

9.
J Transl Med ; 22(1): 564, 2024 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-38872164

RESUMO

BACKGROUND/PURPOSE(S): The gut microbiota and its metabolites play crucial roles in pathogenesis of arthritis, highlighting gut microbiota as a promising avenue for modulating autoimmunity. However, the characterization of the gut virome in arthritis patients, including osteoarthritis (OA) and gouty arthritis (GA), requires further investigation. METHODS: We employed virus-like particle (VLP)-based metagenomic sequencing to analyze gut viral community in 20 OA patients, 26 GA patients, and 31 healthy controls, encompassing a total of 77 fecal samples. RESULTS: Our analysis generated 6819 vOTUs, with a considerable proportion of viral genomes differing from existing catalogs. The gut virome in OA and GA patients differed significantly from healthy controls, showing variations in diversity and viral family abundances. We identified 157 OA-associated and 94 GA-associated vOTUs, achieving high accuracy in patient-control discrimination with random forest models. OA-associated viruses were predicted to infect pro-inflammatory bacteria or bacteria associated with immunoglobulin A production, while GA-associated viruses were linked to Bacteroidaceae or Lachnospiraceae phages. Furthermore, several viral functional orthologs displayed significant differences in frequency between OA-enriched and GA-enriched vOTUs, suggesting potential functional roles of these viruses. Additionally, we trained classification models based on gut viral signatures to effectively discriminate OA or GA patients from healthy controls, yielding AUC values up to 0.97, indicating the clinical utility of the gut virome in diagnosing OA or GA. CONCLUSION: Our study highlights distinctive alterations in viral diversity and taxonomy within gut virome of OA and GA patients, offering insights into arthritis etiology and potential treatment and prevention strategies.


Assuntos
Artrite Gotosa , Microbioma Gastrointestinal , Osteoartrite , Viroma , Humanos , Artrite Gotosa/virologia , Artrite Gotosa/microbiologia , Masculino , Osteoartrite/virologia , Osteoartrite/microbiologia , Feminino , Pessoa de Meia-Idade , Estudos de Casos e Controles , Idoso , Metagenômica , Fezes/virologia , Fezes/microbiologia
10.
Nat Mater ; 22(3): 322-328, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36781951

RESUMO

Utilization of the interaction between spin and heat currents is the central focus of the field of spin caloritronics. Chiral phonons possessing angular momentum arising from the broken symmetry of a non-magnetic material create the potential for generating spin currents at room temperature in response to a thermal gradient, precluding the need for a ferromagnetic contact. Here we show the observation of spin currents generated by chiral phonons in a two-dimensional layered hybrid organic-inorganic perovskite implanted with chiral cations when subjected to a thermal gradient. The generated spin current shows a strong dependence on the chirality of the film and external magnetic fields, of which the coefficient is orders of magnitude larger than that produced by the reported spin Seebeck effect. Our findings indicate the potential of chiral phonons for spin caloritronic applications and offer a new route towards spin generation in the absence of magnetic materials.

11.
Opt Lett ; 49(4): 1073-1076, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38359256

RESUMO

We report on the third harmonic generation (THG) in InSb semiconductor irradiated by a terahertz (THz) free electron laser (FEL). The conversion of 4 THz (wavelength 70 µm) FEL outputs into its third harmonic 12 THz was observed. We found that by tuning the sample temperature to 360 K, high conversion efficiency up to 1% can be obtained and is the highest in the THz and FIR regions below 10 THz. We also discuss the observed intensity dependence of the THG with the nonlinear order lower than 3 when the pumping intensity was high.

12.
Opt Lett ; 49(18): 5039-5042, 2024 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-39270224

RESUMO

The nonlinear susceptibility in the terahertz region is expected to have a non-negligible imaginary part originating from the momentum-dependent scattering time of free carriers, but it has been scarcely reported. By utilizing an intense 4 THz beam from a terahertz free electron laser, we investigated the azimuth angle dependence of the third harmonic generation (THG) from semiconductors. The observed angular anisotropy of THG revealed the contribution of the imaginary part of the nonlinear susceptibility originating from the momentum-scattering time relation in addition to its real part originating from the band nonparabolicity. The results provide a deeper understanding of nonlinear optics in the terahertz region.

13.
Eur Arch Psychiatry Clin Neurosci ; 274(3): 595-607, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37318589

RESUMO

Brain neurons support arousal and cognitive activity in the form of spectral transient bursts and cooperate with the peripheral nervous system to adapt to the surrounding environment. However, the temporal dynamics of brain-heart interactions have not been confirmed, and the mechanism of brain-heart interactions in major depressive disorder (MDD) remains unclear. This study aimed to provide direct evidence for brain-heart synchronization in temporal dynamics and clarify the mechanism of brain-heart interaction disruption in MDD. Eight-minute resting-state (closed eyes) electroencephalograph and electrocardiogram signals were acquired simultaneously. The Jaccard index (JI) was used to measure the temporal synchronization between cortical theta transient bursts and cardiac cycle activity (diastole and systole) in 90 MDD patients and 44 healthy controls (HCs) at rest. The deviation JI was used to reflect the equilibrium of brain activity between diastole and systole. The results showed that the diastole JI was higher than the systole JI in both the HC and MDD groups; compared to HCs, the deviation JI attenuated at F4, F6, FC2, and FC4 in the MDD patients. The eccentric deviation JI was negatively correlated with the despair factor scores of the HAMD, and after 4 weeks of antidepressant treatment, the eccentric deviation JI was positively correlated with the despair factor scores of the HAMD. It was concluded that brain-heart synchronization existed in the theta band in healthy individuals and that disturbed rhythm modulation of the cardiac cycle on brain transient theta bursts at right frontoparietal sites led to brain-heart interaction disruption in MDD.


Assuntos
Transtorno Depressivo Maior , Humanos , Encéfalo , Eletroencefalografia , Mapeamento Encefálico , Nível de Alerta , Imageamento por Ressonância Magnética/métodos
14.
Artigo em Inglês | MEDLINE | ID: mdl-38558145

RESUMO

Previous studies about anhedonia symptoms in bipolar depression (BD) ignored the unique role of gender on brain function. This study aims to explore the regional brain neuroimaging features of BD with anhedonia and the sex differences in these patients. The resting-fMRI by applying fractional amplitude of low-frequency fluctuation (fALFF) method was estimated in 263 patients with BD (174 high anhedonia [HA], 89 low anhedonia [LA]) and 213 healthy controls. The effects of two different factors in patients with BD were analyzed using a 3 (group: HA, LA, HC) × 2 (sex: male, female) ANOVA. The fALFF values were higher in the HA group than in the LA group in the right medial cingulate gyrus and supplementary motor area. For the sex-by-group interaction, the fALFF values of the right hippocampus, left medial occipital gyrus, right insula, and bilateral medial cingulate gyrus were significantly higher in HA males than in LA males but not females. These results suggested that the pattern of high activation could be a marker of anhedonia symptoms in BD males, and the sex differences should be considered in future studies of BD with anhedonia symptoms.

15.
Surg Endosc ; 38(8): 4374-4379, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38886229

RESUMO

BACKGROUND: To compare the clinical outcomes in patients with acute perforated peptic ulcer (PPU) treated with over-the-scope clip (OTSC), non-surgical, and surgical interventions, and to explore the effectiveness and safety of OTSC closure. METHODS: Hospital stay, antibiotic use, diet resumption time, and mortality rate were analyzed retrospectively. Binary Logistic regression analysis was used to identify the risk factors influencing PPU complicated with sepsis. RESULTS: Patients were divided into three treatment groups: OTSC (n = 62), non-surgical (n = 72), and surgical (n = 55) groups. The median time (IQR) from symptom onset to admission was 9.0 (4-23) h. 88.71% (55/62) of the patients in In the OTSC group underwent OTSC closure within 24 h (median [IQR] time: 14.5 [7.00-30.25] h). The perforation diameters in the OTSC and surgical groups were 9.87 mm ± 5.97 mm and 8.55 mm ± 6.17 mm, respectively. The median (IQR) hospital stays in the OTSC (9.50 [7.00-12.25] days) and non-surgical group (9.00[7.00-13.00]days) were similar (p > 0.05), but shorter than that in surgical group (12.00[10.00-16.00]days), (p < 0.05). The median duration of antibiotic use was shorter in the OTSC group (7.00[3.00-10.00]) than in the non-surgical group (9.00[7.00-11.00]) and surgical group (11.00[9.00-13.00]) ( p < 0.05); and the time to resume oral feeding was shorter in the OTSC group (4.00[2.00-5.25]) than in the non-surgical group (7.00[6.13-9.00]) and surgical group (8.00[6.53-10.00]), respectively ( p < 0.05). No mortality difference among groups (p = 0.109) was found. Lower albumin level at admission, older age, and elevated creatinine levels were associated with increased sepsis risk, with OR(95%CI) of 0.826 (0.687-0.993), 1.077 (1.005-1.154), and 1.025 (1.006-1.043), respectively (all p < 0.05). CONCLUSION: OTSC closure improves clinical outcomes of acute PPU patients without sepsis. Age, hypoalbuminemia, and baseline renal dysfunction increase the risk of sepsis, while mortality was associated with sepsis and multiorgan dysfunction.


Assuntos
Úlcera Péptica Perfurada , Humanos , Estudos Retrospectivos , Feminino , Masculino , Úlcera Péptica Perfurada/cirurgia , Pessoa de Meia-Idade , Resultado do Tratamento , Idoso , Tempo de Internação/estatística & dados numéricos , Instrumentos Cirúrgicos , Doença Aguda , Adulto
16.
J Chem Phys ; 161(7)2024 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-39158047

RESUMO

Organic-inorganic hybrid perovskite quantum wells exhibit electronic structures with properties intermediate between those of inorganic semiconductors and molecular crystals. In these systems, periodic layers of organic spacer molecules occupy the interstitial spaces between perovskite sheets, thereby confining electronic excitations to two dimensions. Here, we investigate spectroscopic line broadening mechanisms for phonons coupled to excitons in lead-iodide layered perovskites with phenyl ethyl ammonium (PEA) and azobenzene ethyl ammonium (AzoEA) spacer cations. Using a modified Elliot line shape analysis for the absorbance and photoluminescence spectra, polaron binding energies of 11.2 and 17.5 meV are calculated for (PEA)2PbI4 and (AzoEA)2PbI4, respectively. To determine whether the polaron stabilization processes influence the dephasing mechanisms of coupled phonons, five-pulse coherent Raman spectroscopies are applied to the two systems under electronically resonant conditions. The prominence of inhomogeneous line broadening mechanisms detected in (AzoEA)2PbI4 suggests that thermal fluctuations involving the deformable organic phase broaden the distributions of phonon frequencies within the quantum wells. In addition, our data indicate that polaron stabilization primarily involves photoinduced reorganization of the organic phases for both systems, whereas the impulsively excited phonons represent less than 10% of the total polaron binding energy. The signal generation mechanisms associated with our fifth-order coherent Raman experiments are explored with a perturbative model in which cumulant expansions are used to account for time-coincident vibrational dephasing and polaron stabilization processes.

17.
Nano Lett ; 23(17): 8249-8255, 2023 09 13.
Artigo em Inglês | MEDLINE | ID: mdl-37642327

RESUMO

Single-cell analysis of the DNA repair protein is important but remains unachieved. Exploration of nanopipettte technologies in single-cell electroanalysis has recently seen rapid growth, while the θ-nanopipette represents an emerging technological frontier with its potential largely veiled. Here a θ-nanopipette is first applied for single-cell resistive-pulse sensing (RPS) of the important DNA repair protein O6-alkylguanine DNA alkyltransferase (hAGT). The removal of alkyl mutations by hAGT could restore the damaged aptamer linking with a structural DNA carrier, allowing the selective binding of the aptamer to thrombin with precisely matched size to produce distinct RPS signals when passing through the orifice. Kinetic analysis of hAGT repair was studied. Meanwhile, the device shows the simultaneous on-demand infusion of inhibitors to inactivate the hAGT activity, indicative of its potential in drug screening for enhanced chemotherapy. This work provides a new paradigm for θ-nanopipette-based single-cell RPS of a DNA repair protein accompanied by drug evaluation.


Assuntos
Reparo do DNA , Avaliação de Medicamentos , Cinética , Avaliação Pré-Clínica de Medicamentos , Frequência Cardíaca
18.
Int J Mol Sci ; 25(16)2024 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-39201810

RESUMO

Salinity stress severely restricts rice growth. Prohexadione calcium (Pro-Ca) modulation can effectively alleviate salt stress in rice. In this study, we explored the effects of Pro-Ca on enhancing salt tolerance in two rice varieties, IR29 and HD96-1. The results revealed that Pro-Ca markedly enhanced root and shoot morphological traits and improved plant biomass under salt stress. Chlorophyll a and b content were significantly increased, which improved photosynthetic capacity. Transcriptomic and metabolomic data showed that Pro-Ca significantly up-regulated the expression of genes involved in E3 ubiquitin ligases in IR29 and HD96-1 by 2.5-fold and 3-fold, respectively, thereby maintaining Na+ and K+ homeostasis by reducing Na+. Moreover, Pro-Ca treatment significantly down-regulated the expression of Lhcb1, Lhcb2, Lhcb3, Lhcb5, and Lhcb6 in IR29 under salt stress, which led to an increase in photosynthetic efficiency. Furthermore, salt stress + Pro-Ca significantly increased the A-AAR of IR29 and HD96-1 by 2.9-fold and 2.5-fold, respectively, and inhibited endogenous cytokinin synthesis and signal transduction, which promoted root growth. The current findings suggested that Pro-Ca effectively alleviated the harmful effects of salt stress on rice by maintaining abscisic acid content and by promoting oxylipin synthesis. This study provides a molecular basis for Pro-Ca to alleviate salt stress in rice.


Assuntos
Regulação da Expressão Gênica de Plantas , Oryza , Tolerância ao Sal , Oryza/metabolismo , Oryza/efeitos dos fármacos , Oryza/genética , Oryza/crescimento & desenvolvimento , Oryza/fisiologia , Tolerância ao Sal/genética , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Fotossíntese/efeitos dos fármacos , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Cálcio/metabolismo , Estresse Salino , Clorofila/metabolismo , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética
19.
Molecules ; 29(17)2024 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-39274998

RESUMO

The model precatalyst sp3- and sp2-N dinitrogen-coordinated zinc-heteroimidazole has been used as an efficient catalyst for the ring-opening polymerization of cyclic esters. Subsequent to our exceptional active 5,6,7-trihydroquinolin-8-amine-zinc catalysts for the ring-opening polymerization (ROP) of ε-caprolactone, various pyridine-fused cycloalkanones (ring size from five to eight) are developed for the correspondent fused amine-pyridine derivatives and their zinc-heteroimidazole chloride complexes Zn1-Zn8 (LZnCl2) bearing N-diphenylphosphinoethyl pendants. Activated with two equivalents of LiN(SiMe3)2, the title zinc complexes efficiently promote the ROP of L-lactide (L-LA) in situ; among them, Zn4/2Li(NSiMe3)2 catalyzed 500 equivalent L-LA at 80 °C with 92% conversion in 5 min (TOF: 5520 h-1). Under the same conditions, the catalytic efficiency for the ROP of rac-LA by Zn1-Zn8/2Li(NSiMe3)2 was slightly lower than that for L-LA (highest TOF: 4440 h-1). In both cases, cyclooctyl-fused pyridyl-zinc complexes exhibited higher activity than others, while the cycloheptyl-fused zinc complexes showed the lowest activity. The microstructure analysis of the polymers showed they possessed a linear structure capped with CH3O as major and cyclic structure as minor. In this work, all the ligands and zinc complexes were well characterized by 1H/13C/31P NMR, FT-IR spectroscopy as well as elemental analysis.

20.
Angew Chem Int Ed Engl ; 63(23): e202405761, 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38587998

RESUMO

Vitrimers offer a unique combination of mechanical performance, reprocessability, and recyclability that makes them highly promising for a wide range of applications. However, achieving dynamic behavior in vitrimeric materials at their intended usage temperatures, thus combining reprocessability with adaptivity through associative dynamic covalent bonds, represents an attractive but formidable objective. Herein, we couple boron-nitrogen (B-N) dative bonds and B-O covalent bonds to generate a new class of vitrimers, boron-nitrogen vitrimers (BNVs), to endow them with dynamic features at usage temperatures. Compared with boron-ester vitrimers (BEVs) without B-N dative bonds, the BNVs with B-N dative bonds showcase enhanced mechanical performance. The excellent mechanical properties come from the synergistic effect of the dative B-N supramolecular polymer and covalent boron-ester networks. Moreover, benefiting from the associative exchange of B-O dynamic covalent bonds above their topological freezing temperature (Tv), the resultant BNVs also possess the processability. This study leveraged the structural characteristics of a boron-based vitrimer to achieve material reinforcement and toughness enhancement, simultaneously providing novel design concepts for the construction of new vitrimeric materials.

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