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1.
Opt Lett ; 49(3): 570-573, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38300061

RESUMO

Recently, there has been significant interest in the generation of coherent temporal solitons in optical microresonators. In this Letter, we present a demonstration of dissipative Kerr soliton generation in a microrod resonator using an auxiliary-laser-assisted thermal response control method. In addition, we are able to control the repetition rate of the soliton over a range of 200 kHz while maintaining the pump laser frequency, by applying external stress tuning. Through the precise control of the PZT voltage, we achieve a stability level of 3.9 × 10-10 for residual fluctuation of the repetition rate when averaged 1 s. Our platform offers precise tuning and locking capabilities for the repetition frequency of coherent mode-locked combs in microresonators. This advancement holds great potential for applications in spectroscopy and precision measurements.

2.
Angew Chem Int Ed Engl ; 61(22): e202202585, 2022 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-35229423

RESUMO

Asymmetric copolymerization of meso-epoxide and anhydride is a powerful strategy for preparing various isotactic polyesters with two contiguous stereogenic centers. However, the previous binary systems suffered from slow rates at low loadings, poor enantioselectivities and transesterification reactions at enhanced temperatures. Herein, we report novel dinuclear aluminium complexes with multiple chiralities and ammonium salts anchored on ligand frameworks. These bifunctional catalysts exhibit high activities and enantioselectivities for epoxides/anhydrides copolymerizations at harsh conditions via intramolecularly synergistic catalysis, affording polyesters with unprecedented molecular weights and narrow distributions. Notably, no transesterification reactions were observed, significantly different from the binary catalyst/cocatalyst pairs. This study represents a rare example regarding temperature-independent asymmetric induction for preparing chiral polymers from achiral monomers.

3.
Ecology ; 104(5): e4028, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36898962

RESUMO

Factors shaping the interspecific variations in herbivory have puzzled ecologists for decades and several hypotheses have been proposed to explain interspecific variation in leaf herbivory. In a tropical rainforest in Yunnan Province, China, we collected 6732 leaves from 129 species with canopy heights ranging from 1.6 to 65.0 m above the ground. We tested the role of canopy height, the diversity, composition and structural heterogeneity of neighbors and leaf traits in shaping the interspecific variations in herbivory. Results show that leaf herbivory decreased with canopy height and specific leaf area (SLA) and increased with leaf size. However, neighboring species' diversity, composition, and structural heterogeneity showed no association with herbivory. Therefore, neither the visual apparency effect nor the associational resistance effect was detected in this hyperdiverse tropical rainforest. These findings highlight the importance of vertical structure in shaping herbivory patterns in natural communities.


Assuntos
Herbivoria , Árvores , Floresta Úmida , China , Folhas de Planta/química , Características da Vizinhança
4.
Nat Genet ; 55(11): 1964-1975, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37783780

RESUMO

The orange subfamily (Aurantioideae) contains several Citrus species cultivated worldwide, such as sweet orange and lemon. The origin of Citrus species has long been debated and less is known about the Aurantioideae. Here, we compiled the genome sequences of 314 accessions, de novo assembled the genomes of 12 species and constructed a graph-based pangenome for Aurantioideae. Our analysis indicates that the ancient Indian Plate is the ancestral area for Citrus-related genera and that South Central China is the primary center of origin of the Citrus genus. We found substantial variations in the sequence and expression of the PH4 gene in Citrus relative to Citrus-related genera. Gene editing and biochemical experiments demonstrate a central role for PH4 in the accumulation of citric acid in citrus fruits. This study provides insights into the origin and evolution of the orange subfamily and a regulatory mechanism underpinning the evolution of fruit taste.


Assuntos
Citrus sinensis , Citrus , Citrus/genética , Citrus/metabolismo , Citrus sinensis/genética , Citrus sinensis/metabolismo , Ácido Cítrico/metabolismo , Frutas/genética , China
5.
Sci Rep ; 11(1): 5100, 2021 03 03.
Artigo em Inglês | MEDLINE | ID: mdl-33658618

RESUMO

Longhorn beetles are extremely rich wood-boring insects possessing larvae that feed on the xylem of trees and/or lianas, which have detrimental effects on plants; in turn, the hosting plants may play a fundamental role in shaping the longhorn beetle community assemblage. However, factors determining the community assemblage of wood-boring longhorn beetles, particularly along the multiple spatial scales is still in need of further exploration. In this study, we designed an experiment across several spatial scales (from local to macro scales) from tropical to temperate climate gradients in Yunnan province, southwest China to examine to what extend the attributes of host-specificity is shaping the community assemblage along different spatial scales. This study concludes that (1) the wood-boring longhorn beetles showed attributes of host-specificity to a certain degree at the community level, (2) biotic (host plant specificity) and abiotic (climatic gradients) factors jointly shaped community composition of this species along the multiple spatial scales, (3) biotic interactions have a prominent effect on the community composition of this species at local-scale while macroclimatic gradients impose the major control on it at macro-scale. Thus, this study highlights the significance of host specificity in affecting the wood-boring longhorn beetle community assemblage, particularly at local scales.


Assuntos
Besouros/fisiologia , Especificidade de Hospedeiro/fisiologia , Estações do Ano , Temperatura , Árvores/genética , Clima Tropical , Madeira , Animais , China , Filogenia , Dinâmica Populacional , Estatísticas não Paramétricas
6.
Zhongguo Zhong Xi Yi Jie He Za Zhi ; 30(3): 259-63, 2010 Mar.
Artigo em Zh | MEDLINE | ID: mdl-20535922

RESUMO

OBJECTIVE: To explore the relationship between Shen-deficiency syndrome (SDS) and the insert/deficit (I/D) polymorphism types (PMTs) of angiotensin converting enzyme (ACE) gene in longevous elders in Bama area of Guangxi municipality. METHODS: The investigation on 27 centenarians (Group A), 56 elders of 90-99 years old (Group B) and 114 of 60-89 years old (Group C) was carried out by questionnaire, and the polymorphism was detected using polymerize chain reaction detection, single strand conformation polymorphism (SSCP) analysis, and direct sequencing technique. And the study was controlled by 79 naturally died elders within 60-70 years old. RESULTS: The presenting frequencies of SDS in various PMT were D/D, I/D and I/I in rising order. The frequencies of PMT, I/I, I/D and D/D, were 37.04% (10/27), 33.33% (9/27), and 29.63% (8/27) respectively; the frequency rates of I and D alleles were 53.70% (29/54) and 46.30% (25/54) in Group A. Comparison of frequency of D/D and D allele between groups showed that Group A was significantly different to Group C (P<0.05) and also to the control (P<0.01), while all the frequencies in Group A and B were rather identical, showing insignificant difference (P>0.05). SSCP analysis showed no significant difference in D/D among groups. Outcomes of direct sequencing test further proved the correctness of I/D ACE polymorphism detection. CONCLUSION: SDS is closely correlated with ACE gene polymorphism and life span. Whereas, other multiple factors that influence longevity should also be taken into consideration.


Assuntos
Longevidade/genética , Medicina Tradicional Chinesa , Peptidil Dipeptidase A/genética , Polimorfismo Genético , Idoso , Idoso de 80 Anos ou mais , Alelos , Povo Asiático/genética , China , Genoma Humano , Genótipo , Humanos , Pessoa de Meia-Idade
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