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1.
J Asian Nat Prod Res ; 24(7): 634-640, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-34581212

RESUMEN

Three new mexicanolide limonoids were obtained from the 90% ethanol extract of the seeds of Khaya senegalensis. Their structures were elucidated as senegalenines A-C (1-3) by analysing their 1D/2D NMR and MS spectroscopic analysis. In addition, the isolated limonoids were tested in vitro for antimicrobial potentials against 5 pathogenic microorganisms. Consequently, compounds 1-3 exhibited antimicrobial activity against the tested Gram negative bacteria at the minimum inhibitory concentration values less than 40 µg/ml.


Asunto(s)
Limoninas , Meliaceae , Antibacterianos/farmacología , Limoninas/química , Meliaceae/química , Estructura Molecular , Semillas/química
2.
Appl Opt ; 53(2): 278-82, 2014 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-24514061

RESUMEN

A planar waveguide structure in a chalcohalide glass was fabricated by dual-energy C ion implantation with energies of 5.5 and 6.0 MeV at fluences of 7.0×10¹4 and 8.0×10¹4ions cm⁻², respectively. A waveguide with a thickness of 5.9 µm was formed. SRIM 2013 was used to simulate the defect distribution fabricated by C ion implantation. Images of the polished end face of the C-implanted chalcohalide glass were measured with a metallographic microscope using reflected polarized light. The micro-Raman spectra were measured in air. The near-field intensity distributions were investigated at visible (633 nm) and near-infrared (1300, 1400, and 1539 nm) bands.

3.
Appl Opt ; 53(32): 7619-23, 2014 Nov 10.
Artículo en Inglés | MEDLINE | ID: mdl-25402980

RESUMEN

LaAlO3 crystals were implanted by C ions and O ions at an energy of 6.0 MeV with a fluence of 1.5×1015 ions/cm2. The profiles of the guided modes were measured through prism coupling and end-face coupling methods with a 633 nm laser source. A nonleaky waveguide structure in the TM mode was fabricated by O ion implantation after a proper annealing treatment. Characteristics of the implanted C and O ions were compared. Some changes of the full width at half of the maximum and intensity of the Raman spectra were observed between the waveguide and substrate regions in LaAlO3 crystals. Thus, the Raman spectra can be used to visualize any damage or defects in the LaAlO3 crystals during the implantation process.

4.
Appl Opt ; 53(21): 4779-83, 2014 Jul 20.
Artículo en Inglés | MEDLINE | ID: mdl-25090217

RESUMEN

In this work, the optical properties of potassium titanyl phosphate (KTP) waveguides in the visible and near-infrared region are reported. The KTP waveguides were fabricated using 550 keV proton implantation at room temperature, and the refractive index profiles of the implanted region in the visible and near-infrared region were reconstructed. The profiles of the guided modes were measured through the end-face coupling method with both 632.8 and 1539 nm laser sources and then compared with the simulation results using the beam propagation method. Optical transmission and Raman spectra in the original substrate and waveguide active region were measured to study microstructural changes. The propagation loss of the TM0-mode at 632.8 nm was also measured.

5.
J Econ Entomol ; 2024 Jul 23.
Artículo en Inglés | MEDLINE | ID: mdl-39042518

RESUMEN

The predatory gall midge, Aphidoletes aphidimyza (Rondani), and tobacco aphid cocoon wasp, Aphidius gifuensis Ashmead, are important natural enemies of Myzus persicae (Sulzer) (Hemiptera: Aphididae). Predation by A. aphidimyza and A. gifuensis can regulate M. persicae; however, how interspecific interference competition affects their foraging efficiency is unknown. Here, we investigated the consumption and parasitization abilities of A. aphidimyza 3rd instar larva and A. gifuensis adults under various conditions. Consumption of parasitized aphids by A. aphidimyza 3rd instar larvae was significantly lower than that of nonparasitized controls, with a substantial increase in handling time. The presence of A. gifuensis adults did not significantly affect the predation capacity of A. aphidimyza larvae. Relative to controls, A. aphidimyza larvae predation trace (PT) and imago activity significantly decreased A. gifuensis parasitism rates at different aphid densities. Further, A. aphidimyza larvae PT increased the A. gifuensis handling time of M. persicae, whereas the presence of A. aphidimyza adults had the opposite effect. Coexistence with heterospecific natural enemies reduced the parasitic capacity of A. gifuensis, whereas A. aphidimyza larvae predation capability was influenced to a lesser extent. Our results demonstrate that intraguild interactions strongly influence the predatory and parasitic efficacy of A. aphidimyza and A. gifuensis, although the effect on A. gifuensis was more pronounced. For effective biological control of M. persicae using A. aphidimyza and A. gifuensis, we recommend releasing A. aphidimyza first to mitigate intraguild predation and enhance the overall success of the pest control program.

6.
Opt Express ; 21(4): 4671-6, 2013 Feb 25.
Artículo en Inglés | MEDLINE | ID: mdl-23481999

RESUMEN

We report the fabrication of a planar waveguide in polycrystalline zinc sulfide by 6.0 MeV C ions implantation with a fluence of 5 × 10¹4 ion/cm² at room temperature. The near-field light intensity profiles in the visible and near-infrared bands are measured by the end-face coupling method with different laser sources. Investigation of the Raman spectra demonstrates that the microstructure of the polycrystalline zinc sulfide has no significant change after C ion implantation. The absorption spectra show that the implantation processes have no influence on the visible and infrared bands.


Asunto(s)
Refractometría/instrumentación , Sulfuros/química , Sulfuros/efectos de la radiación , Compuestos de Zinc/química , Compuestos de Zinc/efectos de la radiación , Cristalización/métodos , Diseño de Equipo , Análisis de Falla de Equipo , Iones Pesados , Rayos Infrarrojos , Ensayo de Materiales
7.
Zookeys ; 1161: 89-115, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37234736

RESUMEN

The sharpshooter genus Atkinsoniella Distant, 1908 includes 99 valid species worldwide. Here, three new species from China are described and illustrated: Atkinsoniellastenopyga, A.wangi, and A.yingjiangensisspp. nov. An updated checklist of the known Atkinsoniella species worldwide based on the data of previous literature and studied materials is also provided. All the type specimens of three new species are deposited at the Institute of Entomology, Guizhou University, Guiyang, China.

8.
Mitochondrial DNA B Resour ; 8(2): 260-263, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36816061

RESUMEN

Gortyna guizhouensis Wu, Yang, and Han, 2022 (Lepidoptera, Noctuidae) is a newly discovered moth species that feeds on tobacco piths during the larval stage. In this study, we sequenced and analyzed the complete mitochondrial genome (mitogenome) of G. guizhouensis larvae via next-generation sequencing. The mitogenome was 15,441 bp long with an overall A + T content of 79.1%, 13 protein-coding genes (PCGs), 22 transfer RNA genes (tRNAs), two ribosomal RNA subunit genes and one control region. The phylogenetic tree, based on the nucleic acid sequences of 13 shared PCGs of 20 Noctuidae species, revealed that G. guizhouensis is in a well-supported clade with Striacosta albicosta.

9.
Shanghai Kou Qiang Yi Xue ; 32(2): 137-142, 2023 Apr.
Artículo en Zh | MEDLINE | ID: mdl-37153993

RESUMEN

PURPOSE: To investigate the effects of chitosan oligosaccharide on bone metabolism and IKK/NF-κB pathway in mice with osteoporosis and periodontitis. METHODS: Thirty rats were randomly divided into 3 groups, with 10 rats in each group. They were divided into control group, ovariectomized periodontitis group and chitosan oligosaccharide treatment group. Except for the control group, the other two groups were ovariectomized and smeared with Porphyromonas gingivalis fluid to establish the model of osteoporosis with periodontitis. Four weeks after ligation, the rats in chitosan oligosaccharide treatment group were gavaged with 200 mg/kg chitosan oligosaccharide, and the other two groups were gavaged with equal volume of normal saline once a day for 90 days. The periodontal tissues of each group were observed before administration, and the bone mineral density of rats was detected by dual energy X-ray animal bone mineral density and body composition analysis system. After 90 days of administration, the bone mineral density was detected again. After administration, blood was collected from tail vein, and the contents of serum alkaline phosphatase (ALP), bone Gla protein (BGP) and tartrate resistant acid phosphatase 5b (TRACP5b) were measured by enzyme-linked immunodeficient assay. The gingival index and periodontal attachment loss of rats in each group were obtained by visual examination and exploratory examination. The maxilla was removed, and the distance from the enamel cementum boundary to the alveolar crest was measured to obtain alveolar bone absorption value. H-E staining was used to observe the pathology of maxilla in each group. RT-PCR and Western blot were used to detect the nuclear factors in periodontal tissue of rats in each group. SPSS 22.0 software package was used for statistical analysis. RESULTS: Before administration, the gums of the control group were pink without bleeding, and the gums of the other two groups were red and swollen with slight bleeding. After administration, compared with the control group, the bone mineral density, serum ALP, BGP of ovariectomized periodontitis group decreased significantly(P<0.05); while TRACP5b, gingival index, loss of periodontal attachment and alveolar bone resorption, NF-κB and IKK mRNA and protein expression in periodontal tissue increased significantly(P<0.05). Compared with the ovariectomized periodontitis group, the bone mineral density, serum ALP, BGP were significantly increased(P<0.05); while TRACP5b, gingival index, periodontal attachment loss and alveolar bone resorption, NF-κB and IKK mRNA and protein expression in periodontal tissue were significantly decreased (P<0.05). In the ovariectomized periodontitis group, the periodontal tissue combined with epithelium was separated from the tooth surface, the dental pocket was obvious and deep, and the height of alveolar bone decreased. Although dental pocket could be observed in the periodontal tissue of rats treated with chitosan oligosaccharide, it was not obvious, and new bone appeared around the alveolar bone. CONCLUSIONS: Chitosan oligosaccharide can induce biochemical indexes of bone metabolism to become normal, alleviate the symptoms of periodontitis, this may be related to the inhibition of IKK/NF-κB pathway by chitosan oligosaccharide.


Asunto(s)
Pérdida de Hueso Alveolar , Quitosano , Osteoporosis , Periodontitis , Ratas , Ratones , Animales , FN-kappa B , Pérdida de la Inserción Periodontal , Osteoporosis/tratamiento farmacológico , Periodontitis/tratamiento farmacológico , Pérdida de Hueso Alveolar/tratamiento farmacológico , Pérdida de Hueso Alveolar/prevención & control , Oligosacáridos/farmacología
10.
J Econ Entomol ; 116(5): 1496-1504, 2023 10 10.
Artículo en Inglés | MEDLINE | ID: mdl-37476852

RESUMEN

Habrobracon hebetor (Say) (Hymenoptera: Braconidae) is a cosmopolitan, idiobiont, and gregarious ectoparasitoid, which can parasitize the larvae of several pyralid and noctuid moths. However, adult parasitoids require cold storage to ensure that adequate individuals are available when a pest outbreak occurs. To understand the effects of cold storage after acclimation on offspring fitness of H. hebetor, the development, fecundity, population parameters, and paralysis rate of the F1 generation were evaluated using an age-stage, two-sex life table. Four pairing treatments were used in this study, with refrigerated males and females (ReF×ReM), unrefrigerated females and refrigerated males (UnF×ReM), refrigerated females and unrefrigerated males (ReF×UnM), and unrefrigerated females and males (UnF×UnM, control). Cold storage after acclimation had no significant effect on the fecundity or oviposition period of F0-generation H. hebetor. Moreover, the survival rate (Sa = 61.43%), proportion of females (Nf/N = 0.41), intrinsic rate of increase (r = 0.3450), finite rate of increase (λ = 1.4121), net reproduction rate (R0 = 149.47), and net paralysis rate (C0 = 74.52) of ReF×UnM and UnF×UnM (Sa = 50.00%, Nf/N = 0.34, r = 0.3297, λ = 1.3881, R0 = 155.69, C0 = 62.90, respectively) treatments were significantly higher than those of the ReF×ReM treatment (Sa = 45%, Nf/N = 0.16, r = 0.2277, λ = 1.2558, R0 = 68.81, C0 = 31.61, respectively) (except for the Sa of UnF×UnM treatment), and there was no significant difference between the 2 treatments. Overall, it is advisable to avoid simultaneous cold storage of female and male parasitoids or to add unrefrigerated males appropriately when using cold-stored parasitoids to control pests.


Asunto(s)
Himenópteros , Mariposas Nocturnas , Avispas , Masculino , Femenino , Animales , Interacciones Huésped-Parásitos , Control Biológico de Vectores , Larva , Aclimatación , Parálisis
11.
Ecol Evol ; 13(6): e10189, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37325727

RESUMEN

Polyandrous mating can result in sexual conflict and/or promote the evolution of mating patterns. Does multiple mating by females support the genetic benefits hypothesis and can it be validated as an evolutionary strategy? If we are to decipher the consequences of sexual interactions and understand the interplay of sexual conflict and multiple generational benefits, the transgenerational effects need to be followed over multiple generations. We investigated the effects of three mating patterns, single mating, repeated mating, and multiple mating, on parental Spodoptera litura copulation behavior, and then identified the impact on the development, survival, and fecundity of the F1 and F2 generations. Fecundity was not significantly affected in the F1 generation but was substantially enhanced in the F2 generation. There was a reversal of offspring fitness across the F2 generations from the F1 generations in progeny produced by multiple mating. In addition, the intrinsic rate of increase, finite rate of increase and net reproductive rate in the F1 generation the multiple mating treatment was significantly lower than in the single mating treatment, but there was no apparent effect on the F2 generation. Repeated mating had no significant effects on progeny fitness. We postulate that multiple mating imposes cross-transgenerational effects and may ultimately influence multigenerational fitness in S. litura.

12.
Front Physiol ; 14: 1277942, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37954450

RESUMEN

Aphidoletes aphidimyza is a predator that is an important biological agent used to control agricultural and forestry aphids. Although many studies have investigated its biological and ecological characteristics, few molecular studies have been reported. The current study was performed to identify suitable reference genes to facilitate future gene expression and function analyses via quantitative reverse transcription PCR. Eight reference genes glyceraldehyde-3-phosphate dehydrogenase (GAPDH), RPS13, RPL8, RPS3, α-Tub, ß-actin, RPL32, and elongation factor 1 alpha (EF1-α) were selected. Their expression levels were determined under four different experimental conditions (developmental stages, adult tissues, sugar treatment, and starvation treatment) using qRT-PCR technology. The stability was evaluated with five methods (Ct value, geNorm, NormFinder, BestKeeper, and RefFinder). The results showed that GAPDH, RPL32, and EF1-α were ranked as the best reference gene combinations for measuring gene expression levels among different developing stages and in various starvation treatments. RPL8 and RPS3 were recommended to normalize the gene expression levels among different adult tissues. RPL32, ß-actin, and EF1-α were recommended sugar-feeding conditions. To validate the utility of the selected reference pair, RPL8, and RPS3, we estimated the tissue-biased expression level of a chemosensory protein gene (AaphCSP1). As expected, AaphCSP1 is highly expressed in the antennae and lowly expressed in the abdomen. These findings will lay the foundation for future research on the molecular physiology and biochemistry of A. aphidimyza.

13.
Zhonghua Yi Xue Za Zhi ; 92(45): 3215-7, 2012 Dec 04.
Artículo en Zh | MEDLINE | ID: mdl-23328470

RESUMEN

OBJECTIVE: To investigate the genetic feature of Schnyder corneal dystrophy identified in a four-generation Chinese family. METHOD: Ophthalmologic examinations were performed in 3 affected members and 2 unaffected members of a family with Schnyder corneal dystrophy and controls. Genomic DNA was extracted from peripheral blood. The coding regions, 3'UTR and 5'UTR of UBIAD1 gene from all samples were screened by polymerase chain reaction (PCR) and direct DNA sequencing using the primers designed according to the sequence of UBIAD1, and comparatively analyzed with data from Genebank. RESULT: The family has 15 members over 4 generations with similar signs and symptoms among proband and affected members. All affected members of the family demonstrated central discoid crystalline deposition with arcus lipoide. Confocal microscopy examination showed multiple depositions of crystalline materials in anterior stroma. OCT showed the high reflective material localized within the anterior stroma. A missense mutation c.305A > G in 1 exon of UBIAD1 gene resulting in a substitution of Asparagine to Serine at codon 102 (p.Asn102Ser) was found in all affected members of the family who were clinically diagnosed as Schnyder corneal dystrophy while not in the unaffected members of the family and controls. CONCLUSION: The missense mutation c.305A > G(p.Asn102Ser) of UBIAD1 gene may cause the disease of the family. Gene screen can assist clinicians in making definitive diagnosis, presymptomatic diagnosis and prenatal diagnosis.


Asunto(s)
Distrofias Hereditarias de la Córnea/genética , Dimetilaliltranstransferasa/genética , Mutación Missense , Pueblo Asiatico/genética , Secuencia de Bases , Estudios de Casos y Controles , Femenino , Humanos , Masculino , Linaje , Análisis de Secuencia de ADN
14.
Insects ; 13(3)2022 Mar 03.
Artículo en Inglés | MEDLINE | ID: mdl-35323552

RESUMEN

The herbivorous leafhopper genus Atkinsoniella Distant, 1908 (Hemiptera: Cicadellidae: Cicadellinae), a large genus of subfamily Cicadellinae, consists of 98 valid species worldwide and 88 species recorded in China. Some species of the genus are very similar in morphological characteristics, so they are difficult to identify accurately. In this study, 12 mitochondrial genomes of Atkinsoniella species with similar morphological characteristics were first obtained through high-throughput sequencing, which featured a typical circular molecule of 15,034-15,988 bp in length. The arrangement and orientation of 37 genes were identical to those of typical Cicadellidae mitogenomes. The phylogenetic relationship within the subfamily Cicadellinae was reconstructed using maximum-likelihood (ML) and Bayesian inference (BI) methods based on three concatenated datasets. The topological structures of the six obtained phylogenetic trees were highly consistent. The results suggested that Atkinsoniella was recovered as a monophyletic group and emerged as a sister group with the monophyletic clade of Bothrogonia, Paracrocampsa (part), and Draeculacephala (part). The branches of the 12 newly sequenced species were clearly separated, with most nodes receiving strong support in all analyses. In addition, the key to the 12 Atkinsoniella species was provided to identify species according to morphological characteristics. This study further promotes research on the classification, genetics, evolution, and phylogeny of the genus Atkinsoniella and subfamily Cicadellinae.

15.
PeerJ ; 10: e14026, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36193437

RESUMEN

A new species, Atkinsoniella zizhongi sp. nov. of the subfamily Cicadellinae, was described and illustrated from China. The new species is similar to A. nigrominiatula (Jacobi, 1944), A. limba Kuoh, 1991, A. dormana Li, 1992, A. peaka Yang, Meng et Li, 2017, and A. divaricata Yang, Meng et Li, 2017. But the characteristics of aedeagus and pygofer process can be used to distinguish them easily. The complete mitochondrial genome of the paratype was sequenced and assembled. The mitogenome of A. zizhongi sp. nov. was 16,483 bp in length, with an A+T content of 75.9%, containing 37 typical genes and a control region (CR). The gene order was consistent with the inferred insect ancestral mitochondrial genome. All of the PCGs were determined to have the typical stop codon TAA or TAG, while COX2 and ND5 ended with incomplete termination codons T and TA, respectively. In addition, phylogenetic trees were reconstructed based on PCGs and rRNAs using both the maximum likelihood (ML) and Bayesian inference (BI) methods. The results showed that the intergeneric and interspecific relationships within the subfamily Cicadellinae were completely consistent in all of the phylogenetic trees, except that the different interspecific relationships within the genus Bothrogonia were detected in the ML analysis based on the amino acid sequences. This study enriches the species diversity of Cicadellinae and further promotes research on its phylogeny.


Asunto(s)
Genoma Mitocondrial , Hemípteros , Animales , Filogenia , Genoma Mitocondrial/genética , Teorema de Bayes , Secuencia de Bases
16.
Chin J Integr Med ; 28(12): 1063-1071, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36251140

RESUMEN

OBJECTIVE: To examine whether the combination of Naoxintong Capsule with standard care could further reduce the recurrence of ischemic stroke without increasing the risk of severe bleeding. METHODS: A total of 23 Chinese medical centers participated in this trial. Adult patients with a history of ischemic stroke were randomly assigned in a 1:1 ratio using a block design to receive either Naoxintong Capsule (1.2 g orally, twice a day) or placebo in addition to standard care. The primary endpoint was recurrence of ischemic stroke within 2 years. Secondary outcomes included myocardial infarction, death due to recurrent ischemic stroke, and all-cause mortality. The safety of drugs was monitored. Results were analyzed using the intention-to-treat principle. RESULTS: A total of 2,200 patients were enrolled from March 2015 to March 2016, of whom 143 and 158 in the Naoxintong and placebo groups were lost to follow-up, respectively. Compared with the placebo group, the recurrence rate of ischemic stroke within 2 years was significantly lower in the Naoxintong group [6.5% vs. 9.5%, hazard ratio (HR): 0.665, 95% confidence interval (CI): 0.492-0.899, P=0.008]. The two groups showed no significant differences in the secondary outcomes and safety, including rates of severe hemorrhage, cerebral hemorrhage and subarachnoid hemorrhage (P>0.05). CONCLUSION: The combination of Naoxintong Capsule with standard care reduced the 2-year stroke recurrence rate in patients with ischemic stroke without increasing the risk of severe hemorrhage in high-risk patients. (Trial registration No. NCT02334969).


Asunto(s)
Accidente Cerebrovascular Isquémico , Accidente Cerebrovascular , Adulto , Humanos , Prevención Secundaria/métodos , Accidente Cerebrovascular/tratamiento farmacológico , Accidente Cerebrovascular/prevención & control , Hemorragia Cerebral/tratamiento farmacológico , Hemorragia Cerebral/complicaciones , Método Doble Ciego , Inhibidores de Agregación Plaquetaria
17.
Zootaxa ; 4933(3): zootaxa.4933.3.9, 2021 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-33756792

RESUMEN

Three new species of Mileewini, Mileewa digitata sp. nov., M. furcata sp. nov., M. nigricincta sp. nov., from Tibet, China are described and illustrated.


Asunto(s)
Hemípteros , Animales , China , Tibet
18.
Insects ; 12(4)2021 Apr 11.
Artículo en Inglés | MEDLINE | ID: mdl-33920412

RESUMEN

The complete mitochondrial genomes of Atkinsoniella grahami and Atkinsoniella xanthonota were sequenced. The results showed that the mitogenomes of these two species are 15,621 and 15,895 bp in length, with A+T contents of 78.6% and 78.4%, respectively. Both mitogenomes contain 13 protein-coding genes (PCGs), 22 transfer RNA genes (tRNAs), 2 ribosomal RNA genes (rRNAs), and a control region (CR). For all PCGs, a standard start ATN codon (ATT, ATG, or ATA) was found at the initiation site, except for ATP8, for which translation is initiated with a TTG codon. All PCGs terminate with a complete TAA or TAG stop codon, except for COX2, which terminates with an incomplete stop codon T. All tRNAs have the typical cloverleaf secondary structure, except for trnS, which has a reduced dihydrouridine arm. Furthermore, these phylogenetic analyses were reconstructed based on 13 PCGs and two rRNA genes of 73 mitochondrial genome sequences, with both the maximum likelihood (ML) and Bayesian inference (BI) methods. The obtained mitogenome sequences in this study will promote research into the classification, population genetics, and evolution of Cicadellinae insects in the future.

19.
Mitochondrial DNA B Resour ; 6(2): 613-614, 2021 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-33659707

RESUMEN

The complete mitochondrial genomes of Bothrogonia tongmaiana and Bothrogonia yunana are sequenced and annotated, which are 15,539 and 15,585 bp in length, respectively. Bothrogonia tongmaiana has an A + T content of 79.4% (A 55.7%; C 13.5%; G 7.1%, and T 23.7%), while B. yunana has an A + T content of 80.6% (A 37.5%; C 5.6%; G 13.8%, and T 43.1%). Every mitogenome encodes 13 proteins, 2 ribosomal RNAs, 22 tRNAs, and a control region. The phylogenetic tree was reconstructed based on them and 27 reference species, which could further confirm the status of these two species.

20.
J Colloid Interface Sci ; 599: 586-594, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-33971567

RESUMEN

Common strategies to synthesize graphitic porous carbon nanospheres suffer from energy consumption, exorbitant cost and harsh condition, and lead to closed pore and polydisperse particles. The successful manipulation of adjustable graphitic skeleton, developed porosity, good monodispersity and dispersity of carbon nanospheres is essential to meet their structural varieties and practical applications. Herein, an outside-in catalytic graphitization method is reported to synthesize carbon nanospheres with abovementioned properties, which involves interfacial assembly between layered double hydroxides nanosheets and polymer nanospheres, in-situ generation of nickel nanoparticles, and outside-in catalytic graphitization. The unusual phenomenon is that the in-situ generated nickel nanoparticles are preferentially oriented to the carbon side rather than to the free open space. The interface reactions between nickel nanoparticles and amorphous carbons drive continuous etching of carbon species to form graphitic structure in the interior of spheres. The graphitic structure can be tuned by changing effective charge ratio and pyrolysis conditions and obtained carbon nanospheres possessed good dispersibility in water and ethanol. Moreover, such carbon nanospheres exhibited good performance when used as anodes in lithium-ion batteries. These findings may pave new ways for synthesizing multifarious carbon nanomaterials with adjustable graphitic skeleton, developed porosity, good monodispersity and dispersibility for various applications.

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