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1.
PLoS One ; 19(5): e0301721, 2024.
Article in English | MEDLINE | ID: mdl-38718030

ABSTRACT

Small molecular heat shock proteins (sHSPs) belong to the HSP family of molecular chaperones. Under high-temperature stress, they can prevent the aggregation of irreversible proteins and maintain the folding of denatured proteins to enhance heat resistance. In this study, the CmHSP17.9-1 and CmHSP17.9-2 genes, which were cloned from chrysanthemum (Chrysanthemum×morifolium 'Jinba') by homologous cloning, had a complete open reading frame of 480 bp each, encoding 159 amino acids. The protein subcellular localization analysis showed that CmHSP17.9-1 and CmHSP17.9-2 were located in the cytoplasm and mostly aggregated in granules, especially around the nucleus. Real-time quantitative PCR (qRT-PCR) analysis showed that the relative expression level of the CmHSP17.9-1 and CmHSP17.9-2 genes was highest in the terminal buds of the chrysanthemum, followed by the leaves. CmHSP17.9-1 and CmHSP17.9-2 overex-pression vectors were constructed and used to transform the chrysanthemum; overexpression of these genes led to the chrysanthemum phenotypes being less affected by high-temperature, and the antioxidant capacity was enhanced. The results showed that chrysanthemum with overex-pression of the CmHSP17.9-1 and CmHSP17.9-2 genes had stronger tolerance than the wild type chrysanthemum after high-temperature treatment or some degree of heat exercise, and overex-pression of the CmHSP17.9-1 gene led to stronger heat resistance than that of the CmHSP17.9-2 gene, providing an important theoretical basis for the subsequent molecular breeding and pro-duction applications of chrysanthemum.


Subject(s)
Chrysanthemum , Cloning, Molecular , Gene Expression Regulation, Plant , Plant Proteins , Chrysanthemum/genetics , Plant Proteins/genetics , Plant Proteins/metabolism , Heat-Shock Proteins, Small/genetics , Heat-Shock Proteins, Small/metabolism , Plants, Genetically Modified/genetics , Amino Acid Sequence , Phylogeny
2.
Front Oncol ; 14: 1378405, 2024.
Article in English | MEDLINE | ID: mdl-38665942

ABSTRACT

Background: The simultaneous occurrence of Branchial Cleft Cyst (BCC) and Papillary Thyroid Carcinoma (PTC) represents an unusual malignant tumor, with cases featuring associated lymph node metastasis being particularly rare. This combination underscores an increased potential for metastasis, and the assessment of neck masses, particularly on the lateral aspect, may inadvertently overlook the scrutiny of the thyroid. Therefore, healthcare providers should exercise vigilance, especially in patients over the age of 40, regarding the potential for neck masses to signify metastasis from thyroid malignancies. Currently, surgical intervention stands as the primary effective curative method, while the postoperative administration of radioactive iodine therapy remains a topic of ongoing debate. Case report: In the presented case, a 48-year-old male patient with a right neck mass underwent surgical intervention. The procedure included the excision of the right neck mass, unilateral thyroidectomy with isthmus resection, and functional neck lymph node dissection under tracheal intubation and general anesthesia. Postoperative pathology findings revealed the coexistence of a BCC with metastatic PTC in the right neck mass, as well as papillary carcinoma in the right thyroid lobe. Lymph node metastasis was observed in the central and levels III of the right neck. Conclusion: The rare amalgamation of a BCC with PTC and concurrent lymph node metastasis underscores the invasive nature of this malignancy. Healthcare professionals should be well-acquainted with its clinical presentation, pathological characteristics, and diagnostic criteria. A multidisciplinary approach is strongly recommended to enhance patient outcomes.

3.
Physiol Plant ; 176(3): e14317, 2024.
Article in English | MEDLINE | ID: mdl-38686568

ABSTRACT

The cotton rose (Hibiscus mutabilis) is a plant species commonly found in tropical and subtropical regions. It is remarkably resilient to waterlogging stress; however, the underlying mechanism behind this trait is yet unknown. This study used hypoxia-tolerant "Danbanhong" (DBH) and more hypoxia-sensitive "Yurui" (YR) genotypes and compared their morpho-physiological and transcriptional responses to hypoxic conditions. Notably, DBH had a higher number of adventitious roots (20.3) compared to YR (10.0), with longer adventitious roots in DBH (18.3 cm) than in YR (11.2 cm). Furthermore, the formation of aerenchyma was 3-fold greater in DBH compared to YR. Transcriptomic analysis revealed that DBH had more rapid transcriptional responses to hypoxia than YR. Identification of a greater number of differentially expressed genes (DEGs) for aerenchyma, adventitious root formation and development, and energy metabolism in DBH supported that DBH had better morphological and transcriptional adaptation than YR. DEG functional enrichment analysis indicated the involvement of variety-specific biological processes in adaption to hypoxia. Plant hormone signaling transduction, MAPK signaling pathway and carbon metabolism played more pronounced roles in DBH, whereas the ribosome genes were specifically induced in YR. These results show that effective multilevel coordination of adventitious root development and aerenchyma, in conjunction with plant hormone signaling and carbon metabolism, is required for increased hypoxia tolerance. This study provides new insights into the characterization of morpho-physiological and transcriptional responses to hypoxia in H. mutabilis, shedding light on the molecular mechanisms of its adaptation to hypoxic environments.


Subject(s)
Gene Expression Profiling , Gene Expression Regulation, Plant , Plant Roots/genetics , Plant Roots/physiology , Transcriptome/genetics , Adaptation, Physiological/genetics , Genotype , Plant Growth Regulators/metabolism , Stress, Physiological/genetics
4.
PLoS One ; 19(3): e0300604, 2024.
Article in English | MEDLINE | ID: mdl-38517866

ABSTRACT

BACKGROUND: By comparing the three lateral approaches to thyroidectomy, the feasibility and clinical effects were analyzed, and the advantages of the lateral approach were summarized. METHODS: From January 2022 to January 2023, 52 patients with thyroid cancer admitted to our department were selected and subjected to Lateral approach for thyroidectomy. Among them, 31 patients underwent thyroidectomy via the supraclavicular approach, 13 patients underwent endoscopic thyroidectomy via the subclavicular approach, and 8 patients underwent endoscopic thyroidectomy via the axillary approach. The basic conditions, surgical conditions, complications, postoperative pain scores and postoperative satisfaction of patients in the three approach surgery groups were recorded and analyzed. RESULTS: There were no significant differences among the three approach groups in terms of patient characteristics, number of central lymph node dissections, intraoperative blood loss, postoperative drainage volume, duration of drainage tube placement, length of hospital stay, postoperative pain, satisfaction, and complications. However, the operation time was longest in the subclavicular approach group, followed by the axillary approach group, and shortest in the supraclavicular approach group. The total hospitalization cost was highest in the axillary approach group, followed by the subclavicular approach group, and lowest in the supraclavicular approach group. CONCLUSION: The lateral approach for thyroidectomy is deemed a safe and effective method. The three different approach paths gradually increase in length, allowing for the accumulation of anatomical experience. This approach has a shorter learning curve for clinical doctors and is a favorable choice for patients seeking aesthetic benefits.


Subject(s)
Thyroid Neoplasms , Thyroidectomy , Humans , Thyroidectomy/adverse effects , Clinical Relevance , Feasibility Studies , Thyroid Neoplasms/surgery , Thyroid Neoplasms/pathology , Endoscopy/adverse effects , Endoscopy/methods , Retrospective Studies
5.
J Am Chem Soc ; 146(11): 7658-7667, 2024 Mar 20.
Article in English | MEDLINE | ID: mdl-38452365

ABSTRACT

High-power phosphor-converted white light-emitting diodes (hp-WLEDs) have been widely involved in modern society as outdoor lighting sources. In these devices, due to the Joule effect, the high applied currents cause high operation temperatures (>500 K). Under these conditions, most phosphors lose their emission, an effect known as thermal quenching (TQ). Here, we introduce a zero-dimensional (0D) metal halide, Rb3InCl6:xSb3+, as a suitable anti-TQ phosphor offering robust anti-TQ behavior up to 500 K. We ascribe this behavior of the metal halide to two factors: (1) a compensation process via thermally activated energy transfer from structural defects to emissive centers and (2) an intrinsic structural rigidity of the isolated octahedra in the 0D structure. The anti-TQ phosphor-based WLEDs can stably work at a current of 2000 mA. The low synthesis cost and nontoxic composition reported here can herald a new generation of anti-TQ phosphors for hp-WLED.

6.
Hortic Res ; 11(2): uhad278, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38371636

ABSTRACT

The double flower is an important trait with substantial ornamental value. While mutations in PETALOSA TOE-type or AG (AGAMOUS) genes play a crucial role in enhancing petal number in ornamental plants, the complete mechanism underlying the formation of double flowers remains to be fully elucidated. Through the application of bulked segregant analysis (BSA), we identified a novel gene, APETALA2-like (PmAP2L), characterized by a 49-bp deletion in double-flowered Prunus mume. ß-Glucuronidase (GUS) staining and luciferase reporter assays confirmed that the 49-bp deletion in PmAP2L reduced its binding with Pmu-miRNA172a. Phylogenetic analysis and microsynteny analysis suggested that PmAP2L was not a PETALOSA TOE-type gene, and it might be a new gene controlling the formation of double flower in P. mume. Subsequently, overexpression of PmAP2L-D in tobacco led to a significant rise in the number of stamens and the conversion of stamens to petals. Furthermore, silencing of the homologue of RC5G0530900 in rose significantly reduced the number of petals. Using transient gene expression in P. mume flower buds, we determined the functional differences between PmAP2L-D and PmAP2-S in controlling flower development. Meanwhile, DNA-affinity purification sequencing (DAP-seq), yeast hybrid assays and luciferase reporter assays indicated that PmAP2L negatively regulated the floral organ identity genes by forming a repressor complex with PmTPL and PmHDA6/19. Overall, these findings indicate that the variation in PmAP2L is associated with differences in the regulation of genes responsible for floral organ identity, providing new insights into the double-flower trait and double-flower breeding in plants.

7.
Front Immunol ; 14: 1277955, 2023.
Article in English | MEDLINE | ID: mdl-38111572

ABSTRACT

Background: Rhoptry organelle proteins (ROPs) secreted by apicomplexan parasites play important roles during parasites invasion and survival in host cells, and are potential vaccine candidates against apicomplexan diseases. Eimeria tenella (E. tenella) is one of the most noteworthy apicomplexan species, which causes hemorrhagic pathologies. Although dozens of putative E. tenella ROP sequences are annotated, most ROP proteins are not well studied. Methods: In this study, an E. tenella ROP21 gene was identified and the recombinant EtROP21 protein (rEtROP21) was expressed in Escherichia coli. The developmental expression levels, localization, and protective efficacy against E. tenella infection in chickens were studied. Results: An EtROP21 gene fragment with an open reading frame (ORF) of 981 bp was obtained from the Beijing strain of E. tenella. The rEtROP21 has a molecular weight of approximately 50 kDa and was recognized by rEtROP21-immunized mouse serum. Two specific protein bands, about 43 KDa and 95 KDa in size, were detected in the whole sporozoite proteins using the rEtROP21-immunized chicken serum. RT-qPCR analysis of the E. tenella ROP21 gene (EtROP21) revealed that its mRNA levels were higher in merozoites and sporozoites than in sporulated and unsporulated oocysts. Immunofluorescence and immunoelectron analyses showed that the EtROP21 protein predominantly localizes in the bulb region of rhoptries distributed at anterior, posterior, and perinuclear regions of E. tenella sporozoites. Immunization and challenge experiments revealed that immunizing chickens with rEtROP21 significantly increased their average body weight gain while decreasing mean lesion score and oocyst output (P <0.05). When compared with the challenged control group, the rEtROP21-immunized group was associated with a significantly higher relative weight gain (90.2%) and a greater reduction in oocyst output (67%) (P <0.05). The anticoccidial index of the rEtROP21-immunized group was 163.2. Chicken serum ELISA revealed that the levels of the specific anti- rEtROP21 antibody, IFN-γ, and IL-4 were significantly higher in the rEtROP21-immunized group than in the challenged control group (P <0.05). Conclusion: These results indicate that rEtROP21 can induce a high level of specific immune response and it is a potential candidate for the development of vaccines against E. tenella infection in chickens.


Subject(s)
Coccidiosis , Eimeria tenella , Animals , Mice , Protozoan Proteins , Coccidiosis/prevention & control , Coccidiosis/veterinary , Chickens , Recombinant Proteins , Sporozoites , Oocysts/metabolism
8.
PeerJ ; 11: e16436, 2023.
Article in English | MEDLINE | ID: mdl-38111658

ABSTRACT

The chrysanthemum DgLsL gene, homologous with tomato Ls, is one of the earliest expressed genes controlling axillary meristem initiation. In this study, the wild-type chrysanthemum (CW) and DgLsL-overexpressed line 15 (C15) were used to investigate the regulatory mechanism of axillary bud development in chrysanthemum. Transcriptome sequencing was carried out to detect the differentially expressed genes of the axillary buds 0 h, 24 h and 48 h after decapitation. The phenotypic results showed that the number of axillary buds of C15 was significantly higher than CW. A total of 9,224 DEGs were identified in C15-0 vs. CW-0, 10,622 DEGs in C15-24 vs. CW-24, and 8,929 DEGs in C15-48 vs. CW-48.GO and KEGG pathway enrichment analyses showed that the genes of the flavonoid, phenylpropanoids and plant hormone pathways appeared to be differentially expressed, indicating their important roles in axillary bud germination. DgLsL reduces GA content in axillary buds by promoting GA2ox expression.These results confirmed previous studies on axillary bud germination and growth, and revealed the important roles of genes involved in plant hormone biosynthesis and signal transduction, aiding in the study of the gene patterns involved in axillary bud germination and growth.


Subject(s)
Chrysanthemum , Plant Growth Regulators , Plant Growth Regulators/genetics , Chrysanthemum/genetics , Gene Expression Profiling/methods , Cell Division
9.
Nano Lett ; 23(19): 9050-9055, 2023 Oct 11.
Article in English | MEDLINE | ID: mdl-37756015

ABSTRACT

We report the colloidal synthesis of Bi-doped Cs2AgxNa1-xInCl6 double perovskite nanoplatelets (NPLs) exhibiting a near-unity photoluminescence quantum yield (PLQY), a record emission efficiency for nanoscale lead-free metal halides. A combination of optical spectroscopies revealed that nonradiative decay processes in the NPL were suppressed, indicating a well-passivated surface. By comparison, nanocubes with the same composition and surface ligands as the NPLs had a PLQY of only 40%. According to our calculations, the type of trap states arising from the presence of surface defects depends on their specific location: defects located on the facets of nanocubes generate only shallow traps, while those at the edges result in deep traps. In NPLs, due to their extended basal facets, most of the surface defects are facet defects. This so-called facet-defect tolerant behavior of double perovskites explains the more efficient optical emission of NPLs compared to that of nanocubes.

10.
Chem Sci ; 14(31): 8401-8407, 2023 Aug 09.
Article in English | MEDLINE | ID: mdl-37564418

ABSTRACT

Herein, a triphenylamine derivative (TP-3PY) possessing 4-(4-bromophenyl)pyridine (PY) as an electron-accepting group and tris[p-(4-pyridylvinyl)phenyl]amine (TPA) with large two-photon absorption cross-sections as an electron-donating group was obtained, and showed intense absorption in the visible light region (λmax = 509 nm) and weak near-infrared (NIR) fluorescence emission at 750 nm. After complexation with cucurbit[8]uril (CB[8]), TP-3PY showed bright NIR fluorescence emission at 727 nm and phosphorescence emission at 800 nm. When the supramolecular assembly (TP-3PY⊂CB[8]) further interacted with dodecyl-modified sulfonatocalix[4]arene (SC4AD), the fluorescence and phosphorescence emissions were further enhanced at 710 and 734 nm, respectively. However, only the fluorescence emission of TP-3PY was enhanced in the presence of cucurbit[7]uril (CB[7]) and SC4AD. More interestingly, the photoluminescence of TP-3PY⊂CB[8]@SC4AD and TP-3PY⊂CB[7]@SC4AD assemblies could be excited by both visible (510 nm) and NIR light (930 nm). Finally, these ternary supramolecular assemblies with bright NIR light emission were applied to lysosome imaging of tumor cells and real-time biological imaging of mice.

11.
Int J Mol Sci ; 24(16)2023 Aug 12.
Article in English | MEDLINE | ID: mdl-37628910

ABSTRACT

Primula forbesii Franch. is a unique biennial herb with a strong floral fragrance, making it an excellent material for studying the aroma characteristics of the genus Primula. The floral scent is an important ornamental trait that facilitates fertilization. However, the molecular mechanism regulating the floral scent in Primula is unknown. In order to better understand the biological mechanisms of floral scents in this species, this study used RNA sequencing analysis to discuss the first transcriptome sequence of four flowering stages of P. forbesii, which generated 12 P. forbesii cDNA libraries with 79.64 Gb of clean data that formed 51,849 unigenes. Moreover, 53.26% of the unigenes were annotated using public databases. P. forbesii contained 44 candidate genes covering all known enzymatic steps for the biosynthesis of volatile terpenes, the major contributor to the flower's scent. Finally, 1-deoxy-d-xylulose 5-phosphate synthase gene of P. forbesii (PfDXS2, MK370094), the first key enzyme gene in the 2-c-methyl-d-erythritol 4-phosphate (MEP) pathway of terpenoids, was cloned and functionally verified using virus-induced gene silencing (VIGs). The results showed that PfDXS2-silencing significantly reduced the relative concentrations of main volatile terpenes. This report is the first to present molecular data related to aroma metabolites biosynthesis pathways and the functional characterization of any P. forbesii gene. The data on RNA sequencing provide comprehensive information for further analysis of other plants of the genus Primula.


Subject(s)
Odorants , Primula , Primula/genetics , Gene Expression Profiling , Transcriptome , Pheromones
12.
Int J Mach Learn Cybern ; : 1-24, 2023 Apr 26.
Article in English | MEDLINE | ID: mdl-37360882

ABSTRACT

With the massive increase in uncertainty of linguistic information in realistic decision making, there is a great challenge for people to make decisions in the complex linguistic environment. To overcome this challenge, this paper proposes a three-way decisions method based on aggregation operators of strict t-norms and t-conorms under double hierarchy linguistic environment. By mining the double hierarchy linguistic information, strict t-norms and t-conorms are introduced to define the operation rules and their operation examples are also given. Then, the double hierarchy linguistic weighted average (DHLWA) operator and weighted geometric (DHLWG) operator are proposed based on strict t-norms and t-conorms. Besides, some of their important properties are also proved and derived, such as idempotency, boundedness and monotonicity. Next, DHLWA and DHLWG are integrated with three-way decisions to construct our three-way decisions model. Specifically, the double hierarchy linguistic decision theoretic rough set (DHLDTRS) model is constructed by incorporating the computational model of expected loss with DHLWA and DHLWG, which can consider the various decision attitudes from decision makers more adequately. Furthermore, we also propose a novel entropy weight calculation formula to improve the entropy weight method for obtaining the weights more objectively, and integrate grey relational analysis (GRA) method to calculate the conditional probability. Based on the Bayesian minimum-loss decision rules, the solving method of our model is also propounded and the corresponding algorithm is designed. Finally, an illustrative example and experimental analysis are presented, which can validate the rationality, robustness as well as superiority of our method.

13.
Zhen Ci Yan Jiu ; 48(6): 557-63, 2023 Jun 25.
Article in Chinese | MEDLINE | ID: mdl-37385786

ABSTRACT

OBJECTIVE: To observe the effects of electroacupuncture pretreatment on postoperative cognitive dysfunction (POCD), neuronal apoptosis and neuron-inflammation in aged rats. METHODS: Thirty-six male SD rats aged 20 months were randomly divided into sham operation group, model group and electroacupuncture (EA) group, with 12 rats in each group. The POCD rats model was prepared by internal fixation of left tibial fracture. Five days before modeling, EA stimulation (2 Hz/15 Hz, 1 mA, 30 min) was applied to "Zusanli" (ST36), "Hegu" (LI4) and "Neiguan" (PC6) on the unaffected side of rats in the EA group, once a day for consecutive 5 d. The learning and memory abilities of rats were evaluated by water maze test 31-35 days after operation. The apoptosis of hippocampal neurons was observed by Tunel/NeuN double staining. The expressions of high mobility group protein B1 (HMGB1) and phosphorylated (p)-nuclear factor (NF)-κB in microglia cells in hippocampal dentate gyrus were detected by immunofluorescence staining. The expression levels of interleukin (IL)-6 and IL-1ß in the hippocampus were detected by Western blot. RESULTS: Compared with the sham operation group, the escape latency was prolonged (P<0.05); the frequency of crossing the original platform, ratio of the swimming distance and the time in the target quadrant of the Morris water maze were significantly decreased (P<0.05); the apoptosis rate of hippocampal neurons was significantly increased (P<0.05); the expressions of HMGB1 and p-NF-κB in microglia cells in the dentate gyrus and the expression levels of IL-6 and IL-1ß in hippocampus were increased (P<0.05) in the model group. Compared with the model group, the results of the above indexes were all opposite (P<0.05) in the EA group. CONCLUSION: EA preconditioning can regulate hippocampal inflammatory response, alleviate neuronal apoptosis rate and long-term cognitive dysfunction in aged rats with POCD, the mechanisms may be related to the inhibition of microglia HMGB1/NF-κB pathway in hippocampal dentate gyrus.


Subject(s)
Electroacupuncture , Neuroinflammatory Diseases , Postoperative Cognitive Complications , Animals , Rats , Postoperative Cognitive Complications/prevention & control , Postoperative Cognitive Complications/therapy , Neuroinflammatory Diseases/prevention & control , Neuroinflammatory Diseases/therapy , HMGB1 Protein/genetics , Gene Expression Regulation , NF-kappa B/genetics , Interleukin-6/genetics , Interleukin-1beta/genetics
14.
Adv Sci (Weinh) ; 10(20): e2300666, 2023 Jul.
Article in English | MEDLINE | ID: mdl-37166134

ABSTRACT

Due to their tantalizing prospect of heat-electricity interconversion, hybrid organic-inorganic perovskites have sparked considerable research interests recently. Nevertheless, understanding their complex interplay between the macroscopic properties, nonintuitive transport processes, and basic chemical structures still remains far from completion, although it plays a fundamental role in systematic materials development. On the basis of multiscale first-principles calculations, this understanding is herein advanced by establishing a comprehensive picture consisting of atomic and charge dynamics. It is unveiled that the ultralow room-temperature lattice thermal conductivity (≈0.20 W m-1 K-1 ) of hybrid perovskites is critical to their decent thermoelectric figure of merit (≈0.34), and such phonon-glass behavior stems from not only the inherent softness but also the strong anharmonicity. It is identified that the 3D electrostatic interaction and hydrogen-bonded networks between the PbI3- cage and embedded cations result in the strongly coupled motions of inorganic framework and cation, giving rise to their high degree of anharmonicity. Furthermore, such coupled motions bring about low-frequency optical vibrational modes, which leads to the dominant role of electron scattering with optical phonons in charge transport. It is expected that these new atomistic-level insights offer a standing point where the performance of thermoelectric perovskites can be further enhanced.

15.
Nat Commun ; 14(1): 2517, 2023 May 02.
Article in English | MEDLINE | ID: mdl-37130878

ABSTRACT

Oxygen evolution reaction catalysts capable of working efficiently in acidic media are highly demanded for the commercialization of proton exchange membrane water electrolysis. Herein, we report a Zn-doped RuO2 nanowire array electrocatalyst with outstanding catalytic performance for the oxygen evolution reaction under acidic conditions. Overpotentials as low as 173, 304, and 373 mV are achieved at 10, 500, and 1000 mA cm-2, respectively, with robust stability reaching to 1000 h at 10 mA cm-2. Experimental and theoretical investigations establish a clear synergistic effect of Zn dopants and oxygen vacancies on regulating the binding configurations of oxygenated adsorbates on the active centers, which then enables an alternative Ru-Zn dual-site oxide path of the reaction. Due to the change of reaction pathways, the energy barrier of rate-determining step is reduced, and the over-oxidation of Ru active sites is alleviated. As a result, the catalytic activity and stability are significantly enhanced.

17.
Adv Mater ; 35(23): e2211729, 2023 Jun.
Article in English | MEDLINE | ID: mdl-36960911

ABSTRACT

As equally essential as the synthesis of new materials, maneuvering new structure configurations can endow the brand-new functional properties to existing materials, which is also one of the core goals in the synthesis community. In this respect, pressure-induced emission (PIE) that triggers photoluminescence (PL) in nonemission materials is an emerging stimuli-responsive smart materials technology. In the PIE paradigms, harvesting bright PL at ambient conditions, however, has remained elusive. Herein, a remarkable PIE phenomenon is reported in initially nonemission Zn(BDC)(DMF)(H2 O) (MOF-2), which shows bright blue-emission at 455 nm under pressure. Intriguingly, the bright blue PL with an excellent photoluminescence quantum yield up to 70.4% is unprecedentedly retained to ambient conditions upon decompression from 16.2 GPa. The detailed structural analyses combined with density functional theory calculations reveal that hydrogen bonding cooperativity effect elevates powerfully the rotational barrier of the linker rotor to 3.87 eV mol-1 from initial 0.91 eV mol-1 through pressure treatment. The downgrade rotational freedom turns on PL of MOF-2 after releasing pressure completely. This is the first case of harvesting PIE to ambient conditions. These findings offer a new platform for the creation of promising alternatives to high-performance PL materials based on initially nonemission counterparts.

18.
Adv Sci (Weinh) ; 10(12): e2207688, 2023 Apr.
Article in English | MEDLINE | ID: mdl-36807578

ABSTRACT

Carbon dots (CDs) are widely utilized in sensing, energy storage, and catalysis due to their excellent optical, electrical and semiconducting properties. However, attempts to optimize their optoelectronic performance through high-order manipulation have met with little success to date. In this study, through efficient packing of individual CDs in two-dimensions, the synthesis of flexible CDs ribbons is demonstrated technically. Electron microscopies and molecular dynamics simulations, show the assembly of CDs into ribbons results from the tripartite balance of π-π attractions, hydrogen bonding, and halogen bonding forces provided by the superficial ligands. The obtained ribbons are flexible and show excellent stability against UV irradiation and heating. CDs ribbons offer outstanding performance as active layer material in transparent flexible memristors, with the developed devices providing excellent data storage, retention capabilities, and fast optoelectronic responses. A memristor device with a thickness of 8 µm shows good data retention capability even after 104 cycles of bending. Furthermore, the device functions effectively as a neuromorphic computing system with integrated storage and computation capabilities, with the response speed of the device being less than 5.5 ns. These properties create an optoelectronic memristor with rapid Chinese character learning capability. This work lays the foundation for wearable artificial intelligence.

19.
Adv Mater ; 35(5): e2207265, 2023 Feb.
Article in English | MEDLINE | ID: mdl-36408928

ABSTRACT

Chiral carbon dots (Ch-CDs) trigger the full-color circularly polarized luminescence (CPL) of CsPbX3  nanocrystals (NCs). Ch-CDs-CsPbBr3  NCs are successfully synthesized via simple ligand-assisted coprecipitation of Ch-CDs and metal halides precursors at room temperature. Ch-CDs-CsPbBr3  retains emission characteristics of the CsPbBr3  with near-unity photoluminescence quantum yield, and meanwhile has special CPL, with a maximum luminescence dissymmetric factor (glum ) of -3.1 × 10-3 , which is induced by Ch-CDs. This is the first report of chiral perovskite which is induced by other chiral nanomaterials. By anion exchange, CPL can cover almost the entire visible light band. Surprisingly, the chiral signal of Ch-CDs-CsPbBr3  NCs is in-versed under excitation state, which can be induced by the charge transfers between Ch-CDs and perovskite NCs. The combination of perovskites and Ch-CDs pave away for the design of new chiral perovskite on multifunctional applications.

20.
Sci Bull (Beijing) ; 67(14): 1450-1457, 2022 07 30.
Article in English | MEDLINE | ID: mdl-36546188

ABSTRACT

Red-emissive carbon dots (R-CDs) have been widely studied because of their potential application in tissue imaging and optoelectronic devices. At present, most R-CDs are synthesized by using aromatic precursors, but the synthesis of R-CDs from non-aromatic precursors is challenging, and the emission mechanism remains unclear. Herein, different R-CDs were rationally synthesized using citric acid (CA), a prototype non-aromatic precursor, with the assistance of ammonia. Their structural evolution and optical mechanism were investigated. The addition of NH3·H2O played a key role in the synthesis of CA-based R-CDs, which shifted the emission wavelength of CA-based CDs from 423 to 667 nm. Mass spectrometry (MS) analysis indicated that the amino groups served as N dopants and promoted the formation of localized conjugated domains through an intermolecular amide ring, thereby inducing a significant emission redshift. The red-emissive mechanism of CDs was further confirmed by control experiments using other CA-like molecules (e.g., aconitic acid, tartaric acid, aspartic acid, malic acid, and maleic acid) as precursors. MS, nuclear magnetic resonance characterization, and computational modeling revealed that the main carbon chain length of CA-like precursors tailored the cyclization mode, leading to hexatomic, pentatomic, unstable three/four-membered ring systems or cyclization failure. Among these systems, the hexatomic ring led to the largest emission redshift (244 nm, known for CA-based CDs). This work determined the origin of red emission in CA-based CDs, which would guide research on the controlled synthesis of R-CDs from other non-aromatic precursors.


Subject(s)
Quantum Dots , Quantum Dots/chemistry , Carbon/chemistry
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