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1.
Planta ; 259(5): 107, 2024 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-38554244

RESUMO

MAIN CONCLUSION: Early-stage low nitrogen priming promotes root growth and delays leaf senescence through gene expression, enhancing nitrogen absorption and assimilation in wheat seedlings, thereby alleviating growth inhibition under nitrogen deficit stress and supporting normal seedling development. Verifying the strategies to reduce the amount of nitrogen (N) fertilizer while maintaining high crop yields is important for improving crop N use efficiency (NUE) and protecting the environment. To determine whether low N (LN) priming (LNP) can alleviate the impact of N-deficit stress on the growth of wheat seedlings and improve their tolerance to N-deficit stress, we conducted hydroponic experiments using two wheat cultivars, Yangmai 158 (YM158, LN tolerant) and Zaoyangmai (ZYM, LN sensitive) to study the effects of LNP on wheat seedlings under N-deficit stress. N-deficit stress decreased the plant dry weight, leaf area, and leaf N content (LNC), while LNP could significantly reduce this reduction. Distinct sensitivities to N-deficit stress were observed between the wheat cultivars, with ZYM showing an early decrease in leaf N content compared to YM158, which exhibited a late-stage reduction. LNP promoted root growth, expanded N uptake area, and upregulated the expression of TaNRT1.1, TaNRT2.1, and TaNRT2.2 in wheat seedlings, suggesting that LNP can enhance root N uptake capacity to increase N accumulation in plants. In addition, LNP improved the activity of glutamine synthase (GS) to enhance the capacity of N assimilation of plants. The relative expression of TaGS1 in the lower leaves of priming and stress (PS) was lower than that of no priming and stress (NS) after LNP, indicating that the rate of N transfer from the lower leaves to the upper leaves became slower after LNP, which alleviated the senescence of the lower leaves. The relative expression of TaGS2 was significantly increased, which might be related to the enhanced photorespiratory ammonia assimilation capacity after LNP, which reduced the N loss and maintained higher LNC. Therefore, LNP in the early stage can improve the N absorption and assimilation ability and maintain the normal N supply to alleviate the inhibition of N-deficit stress in wheat seedlings.


Assuntos
Plântula , Tetrazóis , Tiazóis , Triticum , Triticum/genética , Nitrogênio/metabolismo , Plantas/metabolismo
2.
Physiol Plant ; 176(3): e14329, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38695156

RESUMO

Although tetraploid wheat has rich genetic variability for cultivar improvement, its physiological mechanisms associated with photosynthetic productivity and resilience under nitrogen (N) deficit stress have not been investigated. In this study, we selected emmer wheat (Kronos, tetraploid), Yangmai 25 (YM25, hexaploid), and Chinese Spring (CS, hexaploid) as materials and investigated the differences in net photosynthetic rate (Pn), carboxylation capacity, electron transfer capacity, photosynthetic product output, and photosynthetic N allocation under normal N (CK) and low N (LN) through hydroponic experiments. Tetraploid emmer wheat (Kronos) had a stronger photosynthetic capacity than hexaploid wheat (YM25, CS) under low N stress, which mainly associated with the higher degree of PSII opening, electron transfer rate, Rubisco content and activity, ATP/ADP ratio, Rubisco activase (Rca) activity and Rubisco activation state, and more leaves N allocation to the photosynthetic apparatus, especially the proportion of N allocation to carboxylation under low N stress. Moreover, Kronos reduced the feedback inhibition of photosynthesis by sucrose accumulation through higher sucrose phosphate synthetase (SPS) activity and triose phosphate utilization rate (VTPU). Overall, Kronos could allocate more N to the photosynthetic components to improve Rubisco content and activity to maintain photosynthetic capacity under low N stress while enhancing triose phosphate output to reduce feedback inhibition of photosynthesis. This study reveals the physiological mechanisms of emmer wheat that maintain the photosynthetic capacity under low N stress, which will provide indispensable germplasm resources for elite low-N-tolerant wheat improvement and breeding.


Assuntos
Nitrogênio , Fotossíntese , Ribulose-Bifosfato Carboxilase , Triticum , Fotossíntese/fisiologia , Triticum/fisiologia , Triticum/genética , Triticum/metabolismo , Nitrogênio/metabolismo , Ribulose-Bifosfato Carboxilase/metabolismo , Estresse Fisiológico , Folhas de Planta/fisiologia , Folhas de Planta/metabolismo , Adaptação Fisiológica , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Clorofila/metabolismo , Complexo de Proteína do Fotossistema II/metabolismo , Glucosiltransferases/metabolismo , Glucosiltransferases/genética
3.
Physiol Plant ; 176(2): e14196, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38433117

RESUMO

Source-sink relationships influence photosynthesis. So far, the limiting factors for photosynthesis of wheat cultivars with different source-sink relationships have not been determined. We aimed to determine the variation patterns of photosynthetic characteristics of wheat cultivars with different source-sink relationships. In this study, two wheat cultivars with different source-sink relationships were selected for photosynthetic physiological analyses. The results showed that YM25 (source-limited cultivar) had higher photosynthetic efficiency compared to YM1 (sink-limited cultivar). This is mainly due to a stronger photochemical efficiency, electron transfer capacity, and Rubisco carboxylation capacity of YM25. YM25 accumulated less soluble carbohydrates in flag leaves than YM1. This is mainly due to the stronger sucrose synthesis and transport capacity of YM25 by presenting higher sucrose-related enzyme activities and gene expression. A PCA analysis showed that Rubisco was the main factor limiting the photosynthetic capacity of YM25. The soluble sugar accumulation in flag leaves and sink limitation decreased the photosynthetic activity of YM1. Increased N application improved source-sink relationships and increased grain yield and source leaf photosynthetic capacity in both two wheat cultivars. Taken together, our findings suggest that Rubisco and sucrose synthesis and translocation are involved in the regulation of photosynthesis of wheat cultivars with different source-sink relationships and that source and sink limitation effects should be considered in photosynthesis.


Assuntos
Ribulose-Bifosfato Carboxilase , Triticum , Triticum/genética , Fotossíntese , Metabolismo dos Carboidratos , Sacarose
4.
Int J Mol Sci ; 25(1)2024 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-38203794

RESUMO

Stabilization of a G-quadruplex (G4) in the promotor of the c-MYC proto-oncogene leads to inhibition of gene expression, and it thus represents a potentially attractive new strategy for cancer treatment. However, most G4 stabilizers show little selectivity among the many G4s present in the cellular complement of DNA and RNA. Intriguingly, a crescent-shaped cell-penetrating thiazole peptide, TH3, preferentially stabilizes the c-MYC G4 over other promotor G4s, but the mechanisms leading to this selective binding remain obscure. To investigate these mechanisms at the atomic level, we performed an in silico comparative investigation of the binding of TH3 and its analogue TH1 to the G4s from the promotors of c-MYC, c-KIT1, c-KIT2, and BCL2. Molecular docking and molecular dynamics simulations, combined with in-depth analyses of non-covalent interactions and bulk and per-nucleotide binding free energies, revealed that both TH3 and TH1 can induce the formation of a sandwich-like framework through stacking with both the top and bottom G-tetrads of the c-MYC G4 and the adjacent terminal capping nucleotides. This framework produces enhanced binding affinities for c-MYC G4 relative to other promotor G4s, with TH3 exhibiting an outstanding binding priority. Van der Waals interactions were identified to be the key factor in complex formation in all cases. Collectively, our findings fully agree with available experimental data. Therefore, the identified mechanisms leading to specific binding of TH3 towards c-MYC G4 provide valuable information to guide the development of new selective G4 stabilizers.


Assuntos
Genes myc , Simulação de Acoplamento Molecular , Peptídeos/farmacologia , Tiazóis/farmacologia
5.
Opt Express ; 31(16): 26757-26763, 2023 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-37710527

RESUMO

A single-frequency quasi-continuous-wave partially end-pumped slab (Innoslab) laser amplifier at 1319 nm was demonstrated. The 3-W single-frequency all-fiber seed laser was amplified to a maximum average power of 80.1 W and the power stability was 0.52% in 10 minutes. The corresponding optical-optical efficiency was 16.1% under absorbed pump power of 478 W. The output pulse width was 131 µs at the repetition of 500 Hz. The beam quality factors of M2 were 1.3 in both the vertical and horizontal directions. To the best of our knowledge, this is the first report on single-frequency Nd:YAG Innoslab amplifier at 1319 nm with such high output power and efficiency.

6.
J Bone Miner Metab ; 41(5): 693-701, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37351651

RESUMO

INTRODUCTION: The aim here is to examine the association between objectively measured usual walking speed (UWS) and bone status in community-dwelling older Chinese. MATERIALS AND METHODS: This is a cross-sectional study of a population of 1528 adults (817 females, mean age 68.5 ± 5.3; 711 males, mean age 69.1 ± 5.2) aged 60-79, living in communities in Shanghai. Walking speed was assessed using a 4-m walk test at a usual-pace walking speed a walking speed at which the subject felt relaxed-and bone status measured by quantitative ultrasound (QUS). The health-related characteristics of participants include family background, physical activity level, chronic disease, smoking and alcohol consumption, frequency of falls, vitamin intake, and hormone therapy. RESULTS: Multiple linear regression is used to analyses any association between UWS and bone status, adjusting for confounding factors showing a significant association between faster UWS and a higher calcaneal stiffness index (SI) (p < 0.01). Comparing the lowest quartile of the data set with the highest at UWS, a high SI is achieved with 5.34 (95% CI = 3.22, 7.46) (p < 0.01), after adjusting for confounders. An increase of 1 dm/s was associated with a 0.91 (95% CI = 0.53, 1.29) increase in SI. This relationship for most subgroups is consistent. CONCLUSION: Our findings suggest that UWS can be a sensitive indicator of calcaneal bone loss among an older population.


Assuntos
Calcâneo , Velocidade de Caminhada , Masculino , Feminino , Humanos , Idoso , Pessoa de Meia-Idade , Calcâneo/diagnóstico por imagem , Estudos Transversais , China , Estado Nutricional , Caminhada
7.
Inorg Chem ; 62(34): 14072-14085, 2023 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-37578854

RESUMO

The organometallic compounds of lithium ions have garnered continuous interest as indispensable precursors for the syntheses of organometallic complexes of main-group metals, transition metals, lanthanide metals, and actinide metals. In this work, we present a strategy for the preparation of a series of polynuclear lithium complexes. This methodology features the utilization of organolithium reagents both as metal sources to coordinate with the ligands and as nucleophilic reagents to undergo nucleophilic addition to the C═N bonds of the ligands. Reaction of a ligand HL1 [HL1 = 2-(((1-(2-(dimethylamino)ethyl)-1H-pyrrol-2-yl)methylene)amino)phenol] with n-BuLi produced complex [Li8(L1a)4]·1.5Tol (1·1.5Tol) [H2L1a = 2-((1-(1-(2-(dimethylamino)ethyl)-1H-pyrrol-2-yl)pentyl)amino)phenol]. One prominent feature regarding the formation of 1·1.5Tol is the occurrence of nucleophilic addition of n-BuLi to the C═N bond of HL1, leading to the generation of a new [L1a]2- ligand that contains both aminophenol and 1-(2-pyrrolyl)alkylamine scaffolds. The developed protocol can be adapted to a series of organolithium reagents. Compounds [Li8(L1b)4] (2) and [Li8(L1c)4] (3) were afforded by treatment of HL1 with sec-BuLi and LiCH2SiMe3, respectively. Reaction of an analogous ligand HL2 [HL2 = 2-(((1-(2-(dimethylamino)ethyl)-1H-pyrrol-2-yl)methylene)amino)-4-methylphenol] with n-BuLi generated compound [Li8(L2a)4] (4). C═N bond activation was not observed in the reaction of HL1 with NaOtBu, and the complex [Na4(L1)4]·Tol (5·Tol) was obtained. A decanuclear complex [Li10(L3a)2(L3b)2] (6) was also prepared via the reaction of HL3 [HL3 = 2-(2-((((1H-pyrrol-2-yl)methylene)amino)methyl)-1H-pyrrol-1-yl)-N,N-dimethylethan-1-amine] with t-BuLi. A remarkable feature in terms of the synthesis of 6 is the simultaneous occurrence of hydrogen atom abstraction from the C-H bond of the pyrrolyl ring and nucleophilic addition to the C═N bond of the HL3 ligand by t-BuLi. A series of amines containing biologically and physiologically important moieties were achieved by hydrolysis of the crude products from the reactions of the HL1-HL3 ligands and organolithium reagents. This work provides an efficient approach to high-nuclearity lithium compounds as well as a series of amines.

8.
Anal Biochem ; 657: 114915, 2022 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-36162446

RESUMO

Quantified inflammatory biomarkers are effective clinical strategy for correct and reasonable drug treatment. In the study, a triple lateral flow immunoassay (triple LFIA) had firstly been developed for specific and simultaneous detection of three pivotal inflammatory biomarkers (PCT, CRP and SAA) via biotin-streptavidin-phycoerythrin signal amplification system in one strip. The developed triple LFIA adopted phycoerythrin (PE) as chromophore to eliminate auto-fluorescence interference from plasma biomolecules and anti-PE mAb as single control line to reduce the nonspecific adsorption, which featured particular advantages in high sensitivity and specificity in a large range of analyte concentrations with the LODs of 0.106 ng/mL for PCT, 0.345 µg/mL for CRP and 3.112 µg/mL SAA, respectively. And the linear quantitative detection ranges were from 0.106 to 100 ng/mL, from 0.345 to 200 µg/mL, and from 3.112 to 200 µg/mL, respectively. Compared to commercial chemiluminescence immunoassay method, the correlations for tested PCT, CRP and SAA in 108 clinical samples were 0.989, 0.987 and 0.988, respectively. In summary, we had proposed a rapid and accurate plasma detection to measure inflammation factors, which facilitated the clinical value to achieve precise treatment.


Assuntos
Biotina , Ficoeritrina , Biomarcadores , Imunoensaio/métodos , Limite de Detecção , Estreptavidina
9.
FASEB J ; 35(4): e21466, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33734496

RESUMO

Conjugated linoleic acid (CLA) may prevent the development of obesity and metabolic disorders. However, the effects of CLA on inflammation and glucose metabolism are controversial. The underlying mechanisms governing the gut microbiota and sexual dimorphisms have also not been elucidated. The present study assessed the effect of CLA on glucose and lipid metabolism in established obesity and examined the mechanism of action based on gut microbiota. Four-week-old C57BL/6J mice were fed a high-fat diet (HFD) for 10 weeks to induce obesity. The diet-induced obese (DIO) mice were fed an HFD supplemented with mixed CLA (50% cis-9, trans-11 isomer and 50% trans-10, cis-12 isomers, 0.2% wt/wt) for 15 weeks. CLA supplementation remarkably reversed body weight in both sexes. CLA favored anti-inflammatory microbiota in male mice, mediating increased short-chain fatty acids and decreased lipopolysaccharide (LPS) production, which alleviated global inflammation and improved insulin sensitivity via inhibition of the TLR4-NF-κB pathway in adipose tissue. CLA promoted the growth of hydrogen sulfide-producing Desulfovibrio and the release of LPS in female mice, which aggravated adipose inflammation and insulin resistance. Although CLA impaired glucose metabolism in females, brown adipose tissue was significantly activated with browning of white adipose tissue in both sexes, which led to enhanced energy expenditure. Fecal transplantation from CLA-treated mice to DIO mice mimicked the sex-dependent phenotype. In conclusion, CLA decreased body weight and increased energy expenditure but sex-dependently modulated insulin resistance via the gut-adipose axis.


Assuntos
Tecido Adiposo/metabolismo , Dieta Hiperlipídica , Microbioma Gastrointestinal/efeitos dos fármacos , Resistência à Insulina/fisiologia , Ácidos Linoleicos Conjugados/farmacologia , Animais , Peso Corporal/efeitos dos fármacos , Microbioma Gastrointestinal/fisiologia , Metabolismo dos Lipídeos/efeitos dos fármacos , Camundongos Endogâmicos C57BL , Obesidade/metabolismo
10.
BMC Pediatr ; 22(1): 106, 2022 02 24.
Artigo em Inglês | MEDLINE | ID: mdl-35209870

RESUMO

BACKGROUND: Inhibitory control develops rapidly during the preschool stage, and development of inhibitory control in this period is significant for the healthy growth of the future. However, most studies paid more attention to children and adolescents in recent years, but less focus on preschool children. Therefore, the purpose of this study was to explore the association between the health-related physical fitness and inhibitory control in preschool children. METHODS: This cross-sectional study was based on a baseline data from randomized controlled trial by cluster sampling(including 128 preschoolers, 70 boys, 58girls).The health-related physical fitness T-score (HPFT) was obtained by adding standard scores of six indicators: body mass index, handgrip strength, standing long jump, one-leg balance, 2 × 10 m shuttle run test, and 20 m shuttle run test. Inhibitory control was assessed using the flanker task and reflected by reaction time and accuracy. RESULTS: A total of 120 preschoolers were included in the final statistical analysis. After adjusting the confounders, HPFT was associated with reaction time (ß=-2.49 ms, 95%CI: -4.22, -0.75). Similarly, a negative association was observed between one-leg balance and reaction time (ß=-12.04 ms, 95%CI: -18.94, -5.15), and between 20 m shuttle run test and reaction time (ß=-23.28 ms, 95%CI: -37.00, -9.56). Compared with the participants in the lowest tertile, HPFT (ß=-158.74, 95%CI: -309.63, -7.84), one-leg balance (ß=-267.25 ms, 95%CI: -420.71, -113.79) and 20 m shuttle run test (ß=-215.58 ms, 95%CI: -374.67, -56.49) were all negatively associated with reaction time of those in the highest tertile. CONCLUSIONS: Negative relationships between HPFT and RT of the inhibitory control were observed in preschoolers. To have better inhibitory control, it's suggested that HPFT of preschoolers should be at least 249. These findings are of great significance for the early improvement of HPFT and the development of inhibitory control in preschool children.


Assuntos
Teste de Esforço , Força da Mão , Adolescente , Índice de Massa Corporal , Pré-Escolar , Estudos Transversais , Humanos , Masculino , Aptidão Física
11.
Opt Express ; 29(4): 5687-5693, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33726103

RESUMO

In this paper, a single-frequency quasi-continuous-wave partially pumped slab (Innoslab) amplifier at 1064 nm is reported. The 4.4-W single-frequency seed laser was amplified to 148.1 W with optical-optical efficiency of 30.4%. The output pulse duration was 141.4 µs at the repetition of 500 Hz. The beam quality factors of M2 were 1.41 and 1.37 in the horizontal and vertical direction respectively. The experimental results match well with the numerical simulation. To the best of our knowledge, this is the first report on single-frequency Nd:YAG Innoslab amplifier with such a high output power and efficiency.

12.
Appl Opt ; 60(4): 971-975, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-33690406

RESUMO

In this paper, a two-stage partially pumped slab (Innoslab) microsecond amplifier at 1064 nm is reported. The 4.4-W single-frequency seed laser is amplified to 303.6 W, with an overall optical-optical efficiency of 25.7%. The overlapping efficiency of the first- and second- amplifier stage is 67% and 55.6%, respectively. The pulse width is 145.0 µs, at a repetition rate of 500 Hz, and the beam quality factor of M2 is 1.84 and 1.71 in the horizontal and vertical directions, respectively. With higher overlap between the pump volume and the seed laser mode, the output power and optical-optical efficiency can be further improved.

13.
Int Wound J ; 18(1): 24-31, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33124156

RESUMO

The purpose of this study was to evaluate the therapeutic effects of artificial dermis combined with autologous split-thickness skin grafting (STSG) compared with autologous intermediate-thickness skin grafting (ITSG) alone in severely burned patients. Fifty-six severely burned patients admitted to our hospital from December 2017 to January 2019 were enrolled and evenly grouped according to the random number table method [AD-STSG group: 28 patients, receiving the treatment of artificial dermis (AD) combined with autologous STSG; ITSG group: 28 patients, receiving autologous ITSG treatment alone]. The healing time and Vancouver Scar Scale (VSS) score of the donor area and graft area, survival rate and infection status of the autologous skin, psychological status (determined by Self-rating Anxiety Scale and Self-rating Depression Scale), and the activity of functional parts of all enrolled patients were included in the evaluation. General items of patients in AD-STSG group and ITSG group, including age, sex, and degree of burn, were all comparable. A significantly shortened healing time of donor skin in AD-STSG group was observed when compared with ITSG group (P < .05) while the recipient skin healed in the same tendency between the two groups. In addition, 21 days after the operation, AD-STSG group presented with significantly higher survival rate of graft skin than ITSG group (P < .05) while same infection status was observed in the two groups. Significantly lower VSS scores were found in AD-STSG group than that in ITSG group 3-, 6- and 10-months after operation (P < .05). Statistical difference regarding psychological status of patients from two groups was unobservable before operation while significantly lower Self-rating Anxiety Scale (SAS) and Self-rating Depression Scale (SDS) scores were found in AD-STSG group than that in ITSG group 3-, 6- and 10-months after operation (P < .05). Also, AD-STSG group presented improved mobility of functional part than that in ITSG group 10-months after operation without statistical difference (P = .051). Artificial dermis combined with autologous split-thickness skin grafting showed better therapeutic outcomes for the treatment of severely burned patients than autologous intermediate-thickness skin grafting in terms of graft healing time, scar formation, psychological recovery, and perhaps in functional reconstruction.


Assuntos
Queimaduras , Transplante de Pele/métodos , Pele Artificial , Adulto , Queimaduras/cirurgia , Derme , Feminino , Humanos , Masculino , Estudos Prospectivos
14.
J Virol ; 93(6)2019 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-30626674

RESUMO

Horizontal transfer of genetic materials between virus and host has been frequently identified. Three rice planthoppers, Laodelphax striatellus, Nilaparvata lugens, and Sogatella furcifera, are agriculturally important insects because they are destructive rice pests and also the vector of a number of phytopathogenic viruses. In this study, we discovered that a small region (∼300 nucleotides [nt]) of the genome of invertebrate iridescent virus 6 (IIV-6; genus Iridovirus, family Iridoviridae), a giant DNA virus that infects invertebrates but is not known to infect planthoppers, is highly homologous to the sequences present in high copy numbers in these three planthopper genomes. These sequences are related to the short interspersed nuclear elements (SINEs), a class of non-long terminal repeat (LTR) retrotransposons (retroposons), suggesting a horizontal transfer event of a transposable element from the rice planthopper genome to the IIV-6 genome. In addition, a number of planthopper transcripts mapped to these rice planthopper SINE-like sequences (RPSlSs) were identified and appear to be transcriptionally regulated along the different developmental stages of planthoppers. Small RNAs derived from these RPSlSs are predominantly 26 to 28 nt long, which is a typical characteristic of PIWI-interacting RNAs. Phylogenetic analysis suggests that IIV-6 acquires a SINE-like retrotransposon from S. furcifera after the evolutionary divergence of the three rice planthoppers. This study provides further examples of the horizontal transfer of an insect transposon to virus and suggests the association of rice planthoppers with iridoviruses in the past or present.IMPORTANCE This study provides an example of the horizontal transfer event from a rice planthopper genome to an IIV-6 genome. A small region of the IIV-6 genome (∼300 nt) is highly homologous to the sequences presented in high copy numbers of three rice planthopper genomes that are related to the SINEs, a class of retroposons. The expression of these planthopper SINE-like sequences was confirmed, and corresponding Piwi-interacting RNA-like small RNAs were identified and comprehensively characterized. Phylogenetic analysis suggests that the giant invertebrate iridovirus IIV-6 obtains this SINE-related sequence from Sogatella furcifera through a horizontal transfer event in the past. To the best of our knowledge, this is the first report of a horizontal transfer event between a planthopper and a giant DNA virus and also is the first evidence for the eukaryotic origin of genetic material in iridoviruses.


Assuntos
Vírus de DNA/genética , Vírus de Insetos/genética , Insetos/virologia , Oryza/virologia , Retroelementos/genética , Animais , Evolução Biológica , Hemípteros/virologia , Filogenia , Elementos Nucleotídeos Curtos e Dispersos/genética
15.
Bioorg Chem ; 96: 103636, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32045775

RESUMO

Three new nardosinane-type sesquiterpenoids linardosinenes A-C (1-3) and four new neolemnane-type sesquiterpenoids lineolemnenes A-D (4-7), together with the related known compound 4-acetoxy-2,8-neolemnadien-5-one (8), were isolated from the Xisha soft coral Litophyton nigrum. The structures of these new compounds were elucidated by comprehensive analyses of spectroscopic data, in association withmodified Mosher's method and ECD calculations for configurational assignments and the absolute configuration of8was determined by X-ray diffraction analysis for the first time. Structurally uncommon nornardosinane and seconeolemnane skeletons for compounds 1 and 7, respectively, are rare carbon frameworks in naturally occurring sesquiterpenoids. The absolute configurations of 1, 7, and 8 were determined by modified Mosher's method, TDDFT ECD approach, and X-ray diffraction analysis, respectively. This is the first chemical study of L. nigrum and the first report of nornardosinane, seconeolemnane and related sesquiterpenoids from the genus Litophyton. The isolates 1-7 were evaluated for their cytotoxicity against THP-1, SNU-398, HT-29, Capan-1 and A549 cell lines and inhibitory activities against PTP1B, BRD4, HDAC1 and HDAC6 protein kinases. The results indicated that compounds 2-5 inhibited proliferation of human cancer cells. However, none of them were potent inhibitors of protein kinases.


Assuntos
Antozoários/química , Antineoplásicos/química , Antineoplásicos/farmacologia , Sesquiterpenos/química , Sesquiterpenos/farmacologia , Animais , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Cristalografia por Raios X , Humanos , Modelos Moleculares , Neoplasias/tratamento farmacológico
16.
Clin Exp Pharmacol Physiol ; 47(5): 892-902, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-31894867

RESUMO

The single-strand human telomere overhang forms intramolecular high-order structures named G-quadruplex (G4) under physiological conditions. Telomere G4 stabilization prevents telomere lengthening by telomerase in cancer cells representing a promising strategy in cancer therapy. Using molecular docking and molecular dynamics (MD) simulations, specific binding of the anionic phthalocyanine 3,4',4'',4'''-tetrasulfonic acid (APC) to the human hybrid (3 + 1) G4s was investigated at the atomic level. We found that APC preferred the end-stacking binding with the telomere hybrid type II (hybrid-II) G4 as compared to the groove binding with the hybrid type I (hybrid-I) G4 remarkable stabilizing effect and more favourable binding free energies. Analysis of non-covalent interaction and decomposition of the binding free energy revealed that van der Waals interaction played a leading role in the binding of APC and telomere hybrid G4s. These findings provide evidence for the first time to shed light on the designs of selective telomere G4 stabilizers.


Assuntos
Quadruplex G , Indóis/metabolismo , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Telômero/metabolismo , Sítios de Ligação , Humanos , Indóis/farmacologia , Isoindóis , Ligantes , Conformação de Ácido Nucleico , Telômero/genética
17.
Opt Express ; 27(15): 20282-20289, 2019 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-31510125

RESUMO

A 208 W all-solid-state modulated-longitudinal-mode quasi-continuous-wave sodium guide star (SGS) laser was developed by sum-frequency of a 1064 nm laser and a 1319 nm laser. The laser contained two spectral lines separated by 1.72 GHz for re-pumping the sodium atoms. To suppress absorption saturation effect of the sodium atoms induced by the high light intensity, we used a white noise generator to modulate the 1064 nm single frequency seed laser in the frequency domain. The line width of the modulated-longitudinal-mode 589 nm laser was maximally broadened to 0.74 GHz compared to the initial line width of ~0.30 GHz. A bright SGS with photon return flux of 56800 photons/s/cm2 during the pulse length was obtained.

18.
Int J Syst Evol Microbiol ; 69(10): 2966-2971, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31418670

RESUMO

A novel actinobacterium, designated LHW52908T, was isolated from a marine sponge, Leucettachagosensis, collected in the South China Sea. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain LHW52908T was member of the family Geodermatophilaceae, with highest similarities to Geodermatophilus obscurus DSM 43160T (97.7 %), Geodermatophilus siccatus CF6T (97.6 %) and Geodermatophiluschilensis B12T (97.5 %). Multilocus sequence analysis confirmed that the strain should be a member of genus Geodermatophilus. Chemotaxonomic characteristics confirmed the genus-level affiliation of strain LHW52908T. Based on phylogenetic data, average nucleotide identity and digital DNA-DNA hybridization results, strain LHW52908T could be distinguished from its closest neighbours, representing a novel species of the genus Geodermatophilus, for which the name Geodermatophilusmarinus sp. nov. is proposed, with the type strain LHW52908T (=DSM 106570T=CCTCC AA 2018014T).


Assuntos
Actinobacteria/classificação , Filogenia , Poríferos/microbiologia , Actinobacteria/isolamento & purificação , Animais , Técnicas de Tipagem Bacteriana , Composição de Bases , China , DNA Bacteriano/genética , Ácidos Graxos/química , Tipagem de Sequências Multilocus , Hibridização de Ácido Nucleico , Oceanos e Mares , Fosfolipídeos/química , Pigmentação , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Vitamina K 2/análogos & derivados , Vitamina K 2/química
19.
Int J Syst Evol Microbiol ; 69(2): 427-433, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30543322

RESUMO

A novel aerobic, spore-forming, marine actinomycete, designated strain LHW63015T, was isolated from a Craniella marine sponge collected in the South China Sea. The strain formed extensively branched substrate and aerial mycelia which carried long and crooked spore chains composed of ridged spores and spherical pseudosporangia. Strain LHW63015T contained meso-diaminopimelic acid as the diagnostic diamino acid. Glucose, ribose, mannose, galactose and madurose occured in whole-cell hydrolysates. The predominant polar lipids were hydroxyl-phosphatidylethanolamine, phosphoglycolipid and ninhydrin-positive phosphoglycolipid. MK-10(H4) and MK-10(H6) were the predominant menaquinones. The major fatty acids were 10-methyl C17 : 0 and C17 : 1ω8c. The G+C content of the genomic DNA was 70.8 mol%. In phylogenetic analysis based on 16S rRNA gene sequences, strain LHW63015T fell within the family Streptosporangiaceae and formed a distinct monophyletic lineage adjacent to the genus Sphaerisporangium, and shared the highest 16S rRNA gene sequence similarity of 96.2 % with Sphaerisporangium album YIM 48782T. On the basis of the polyphasic evidence, a novel genus and species of the family Streptosporangiaceae, for which the name Spongiactinospora rosea gen. nov., sp. nov., is proposed, with the type strain LHW63015T (=DSM 106635T=CCTCC AA 2018019T).


Assuntos
Actinobacteria/citologia , Filogenia , Poríferos/microbiologia , Actinobacteria/isolamento & purificação , Animais , Técnicas de Tipagem Bacteriana , Composição de Bases , China , DNA Bacteriano/genética , Ácido Diaminopimélico/química , Ácidos Graxos/química , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Vitamina K 2/química
20.
Int J Syst Evol Microbiol ; 69(1): 99-104, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30427301

RESUMO

Two marine actinomycete strains, LHW50302T and LHW51701T, were isolated from marine sponges collected in Sansha, Hainan Province, China. The morphological, chemotaxonomic and phylogenetic characteristics were consistent with their classification in the genus Streptomyces. The strains formed hooked and looped chains of arthrospores with smooth surfaces. The cell-wall hydrolysates of the strains contained ll-diaminopimelic acid as the diagnostic diamino acid. MK-9(H8) was the predominant menaquinone. The major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylinositol. Major fatty acids of the strains were iso-C16 : 0, anteiso-C15 : 0 and anteiso-C17 : 0. The 16S rRNA gene sequences indicated that the strains clustered together with Streptomyces albus CGMCC 4.1640T and Streptomyces qinglanensis CGMCC 4.6825T. Multilocus sequence analysis (MLSA) confirmed their relationship. Genome relatedness in forms of average nucleotide identity, digital DNA-DNA hybridization value and MLSA evolutionary distance between each of the strains and its closest relatives showed that they belonged to distinct species. On the basis of these results, strains LHW50302T and LHW51701T belong to two novel species in the genus Streptomyces, for which the names Streptomyces reniochalinae sp. nov. (type strain LHW50302T=CCTCC AA 2018013T=DSM 106194T) and Streptomyces diacarni sp. nov. (type strain LHW51701T=CCTCC AA 2018017T=DSM 106126T) are proposed, respectively.


Assuntos
Filogenia , Poríferos/microbiologia , Streptomyces/classificação , Animais , Técnicas de Tipagem Bacteriana , Composição de Bases , China , DNA Bacteriano/genética , Ácido Diaminopimélico/química , Ácidos Graxos/química , Tipagem de Sequências Multilocus , Hibridização de Ácido Nucleico , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Streptomyces/genética , Streptomyces/isolamento & purificação , Vitamina K 2/análogos & derivados , Vitamina K 2/química
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