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1.
Ann Behav Med ; 58(2): 122-130, 2024 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-37931160

RESUMO

BACKGROUND: To nurture a new online community for health behavior change, a fruitful strategy is to recruit "seed users" to create content and encourage participation. PURPOSE: This study evaluated the impact of support from seed users in an online community for smoking cessation among people living with HIV/AIDS and explored the linguistic characteristics of their interactions. METHODS: These secondary analyses examined data from a randomized trial of a smoking cessation intervention for HIV+ smokers delivered via an online health community (OHC). The analytic sample comprised n = 188 participants randomized to the intervention arm who participated in the community. Independent variables were OHC interactions categorized by participant interlocutor type (study participant, seed user) and interaction type (active, passive). The primary outcome was biochemically verified 7-day abstinence from cigarettes measured 3 months post-randomization; 30-day abstinence was examined for robustness. RESULTS: Logistic regression models showed that participants' interactions with seed users were a positive predictor of abstinence but interactions with other study participants were not. Specifically, the odds of abstinence increased as the number of posts received from seed users increased. Exploratory linguistic analyses revealed that seed users wrote longer comments which included more frequent use of "we" and "you" pronouns and that study participants users used more first-person singular pronouns ("I"). CONCLUSIONS: Seeding a community at its inception and nurturing its growth through seed users may be a scalable way to foster behavior change among OHC members. These findings have implications for the design and management of an OHC capable of promoting smoking cessation.


Online health communities (OHCs) are a popular means for people with similar health concerns to exchange information and support. The success of OHCs depends on members' active participation and on the formation of meaningful relationships. Jumpstarting a new OHC with active members (seed users) can promote engagement and foster its growth. Using data from a multisite randomized controlled trial of a web-based smoking cessation intervention developed specifically for people living with HIV/AIDS (PLWH), we examined whether support provided by seed users in the OHC was a stronger predictor of abstinence from smoking compared with support from other tobacco users who are also trying to quit. These secondary analyses focused on 188 urban, predominantly Black PLWH who smoked that were randomized to the intervention arm and participated in the online community. The primary outcome was biochemically verified 7-day abstinence from cigarettes measured 3 months following study enrollment. Receiving support from seed users was a positive predictor of abstinence among smokers in the trial whereas interactions with other study participants did not relate to abstinence. These findings suggest that for a new OHC, seed users can be critical for generating engagement and promoting health behavior change.


Assuntos
Síndrome da Imunodeficiência Adquirida , Abandono do Hábito de Fumar , Humanos , Fumantes , Terapia Comportamental
2.
Phys Chem Chem Phys ; 26(2): 1284-1292, 2024 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-38105705

RESUMO

Temperature-induced exchange bias is observed in perovskite YbCr1-xFexO3 (x = 0.6-0.9) compounds. This is ascribed to the ferromagnetic (FM) coupling between Fe3+/Cr3+ ions and Yb3+ ions. During demagnetization, the Yb3+ ions will show a tendency to rotate with the direction of the applied magnetic field. However, the antiferromagnetic coupling of Fe3+/Cr3+ ions has a pinning effect, hindering their rotation, and thus producing an exchange bias effect. With increasing Fe3+ ion content, the magnetization and exchange bias field gradually become larger. When x = 0.8 and 0.9, the exchange bias field reaches up to -9.7 kOe and -13.6 kOe at 300 K, respectively. This giant room temperature exchange bias field will be more conducive for practical applications in magnetoelectronic devices.

3.
Age Ageing ; 53(2)2024 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-38300725

RESUMO

BACKGROUND: Frailty in older people can seriously affect their quality of life and increase the demand for long-term care and health care expenses. Aims of this study are to provide an evidence-based basis for clinical practice of frailty in older people by systematically searching for the best current evidence on interventions for the prevention and management of frailty. METHODS: According to the '6S' evidence resource model, evidence retrieval is searched from the top-down and collected relevant guidelines, best practices, evidence summaries, systematic reviews and expert consensus. The retrieval time limit was from the database establishment to 20 March 2023. Two reviewers independently screened and evaluated the literature, and then extracted and summarised the evidence according to the JBI grading of evidence and recommendation system. RESULTS: A total of 44 publications were finally included, including 12 guidelines, 5 best practices, 4 expert consensus, 5 evidence summaries and 18 systematic reviews. Through the induction and integration of the evidence, the evidence was finally summarised from eight aspects: frailty screening, frailty assessment, exercise intervention, nutrition intervention, multi-domain intervention, drug administration, social support and health education, and 43 best evidences were formed. CONCLUSIONS: This study summarised the best evidence for the prevention and management of frailty from eight aspects, which can provide guidance for clinical or community medical staff to develop and apply frailty intervention and practice programmes for older people and improved the clinical outcome and quality of life of older people.


Assuntos
Fragilidade , Humanos , Idoso , Fragilidade/diagnóstico , Fragilidade/prevenção & controle , Qualidade de Vida , Educação em Saúde , Consenso , Assistência de Longa Duração
4.
BMC Med ; 21(1): 324, 2023 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-37626410

RESUMO

BACKGROUND: Chronic remote ischemic conditioning (CRIC) has been shown to improve myocardial ischemia in experimental animal studies; however, its effectiveness in patients with chronic stable angina (CSA) has not been investigated. We conducted a proof-of-concept study to investigate the efficacy and safety of a six-month CRIC treatment in patients with CSA. METHODS: The EARLY-MYO-CSA trial was a prospective, randomized, controlled trial evaluating the CRIC treatment in patients with CSA with persistent angina pectoris despite receiving ≥ 3-month guideline-recommended optimal medical therapy. The CRIC and control groups received CRIC (at 200 mmHg) or sham CRIC (at 60 mmHg) intervention for 6 months, respectively. The primary endpoint was the 6-month change of myocardial flow reserve (MFR) on single-photon emission computed tomography. The secondary endpoints were changes in rest and stress myocardial blood flow (MBF), angina severity according to the Canadian Cardiovascular Society (CCS) classification, the Seattle Angina Questionnaire (SAQ), and a 6-min walk test (6-MWT). RESULTS: Among 220 randomized CSA patients, 208 (105 in the CRIC group, and 103 in the control group) completed the treatment and endpoint assessments. The mean change in MFR was significantly greater in the CRIC group than in the control group (0.27 ± 0.38 vs. - 0.04 ± 0.25; P < 0.001). MFR increased from 1.33 ± 0.48 at baseline to 1.61 ± 0.53 (P < 0.001) in the CRIC group; however, a similar increase was not seen in the control group (1.35 ± 0.45 at baseline and 1.31 ± 0.44 at follow-up, P = 0.757). CRIC treatment, when compared with controls, demonstrated improvements in angina symptoms assessed by CCS classification (60.0% vs. 14.6%, P < 0.001), all SAQ dimensions scores (P < 0.001), and 6-MWT distances (440 [400-523] vs. 420 [330-475] m, P = 0.016). The incidence of major adverse cardiovascular events was similar between the groups. CONCLUSIONS: CSA patients benefit from 6-month CRIC treatment with improvements in MFR, angina symptoms, and exercise performance. This treatment is well-tolerated and can be recommended for symptom relief in this clinical population. TRIAL REGISTRATION: [chictr.org.cn], identifier [ChiCTR2000038649].


Assuntos
Angina Estável , Isquemia Miocárdica , Animais , Angina Estável/terapia , Estudos Prospectivos , Canadá , Doença Crônica
5.
Small ; 19(44): e2304130, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37381654

RESUMO

Aqueous zinc-ion batteries have received continuous interests because of applying low-cost and eco-friendly aqueous electrolytes and having high safety. Beyond energetically to explore new-type cathode materials, it is of great significance to regulate the zinc storage behavior of the existing cathodes in order to understand the underlying working mechanism. Therefore, as a proof of concept, this work achieves the regulation of zinc storage behaviors of the tunnel structure tunnel structure B-phase vanadium dioxide (VO2 (B)) and vanadium oxide (V6 O13 ) cathodes via a simple chemical tungsten-doping induction approach. Under low-concentration tungsten-doping induction of 1, 2 and 3 at.%, the tunnel sizes of VO2 (B) can be controlled readily. Moreover, the V6 O13 with large size tunnels can be achieved by medium-concentration tungsten induction of 6 and 9 at.%. It is demonstrated that tungsten induced VO2 (B) can achieve zinc storage without lattice structure change via operando X-ray diffraction analyses. Remarkably, via operando and non-operando analyses, tungsten induced V6 O13 with lager size tunnels can realize the oriented 1D zinc ion intercalation/deintercalation. The further kinetics analysis shows that the zinc storage is mainly diffusion control, which is different from most of vanadium-based cathodes with capacitance control. This viable tungsten-doping induction strategy provides a new insight into achieving the controllable regulation of zinc storage behaviors.

6.
J Interv Cardiol ; 2023: 6889836, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36998672

RESUMO

Background: This study explored the efficacy of the "L-sandwich" strategy, which involves the implantation of stents in the main vessel (MV) and shaft of the side branch (SB) with a drug-coated balloon (DCB) applied to the SB ostium, for coronary true bifurcation lesions. Methods and Results: Of 99 patients with true bifurcation lesions, 38 patients underwent the "L-sandwich" strategy (group A), 32 patients underwent a two-stent strategy (group B), and 29 patients underwent a single-stent + DCB strategy (group C). Angiography outcomes (late lumen loss [LLL], minimum lumen diameter [MLD]), and clinical outcomes (major adverse cardiac events [MACEs]) were analyzed. At 6 months, the MLD of the SB ostium in groups A and B were similar (P > 0.05) and group A larger than group C (P < 0.05). The LLL of group B was the largest among the three groups (P < 0.05). The MLD of the SB shaft in groups A and B were larger than in group C (P < 0.05). The LLL of the SB shaft in group C was the lowest (P < 0.05). Two patients in group B received target vessel revascularization at the 6-month followup (P > 0.05), and patients in the other groups had no MACEs. Conclusions: The "L-sandwich" strategy was feasible for the treatment of true coronary bifurcation lesions. It is a simpler procedure with similar acute lumen gain than the two-stent strategy, results in a larger SB lumen than the single-stent + DCB strategy, and it can also be used as a remedy for dissection following the single-stent + DCB strategy.


Assuntos
Angioplastia Coronária com Balão , Doença da Artéria Coronariana , Stents Farmacológicos , Humanos , Angioplastia Coronária com Balão/métodos , Angiografia Coronária/métodos , Vasos Coronários/diagnóstico por imagem , Vasos Coronários/cirurgia , Vasos Coronários/patologia , Resultado do Tratamento , Stents , Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/cirurgia
7.
J Org Chem ; 88(8): 5025-5035, 2023 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-36692494

RESUMO

Selective N-methylation of amines with methanol is an important reaction in the synthesis of high-value-added fine chemicals, including dyes, surfactants, pharmaceuticals, agrochemicals, and materials. However, N-methylated amines possess higher reactivities and are prone to further transform into N,N-dimethylated amines. Therefore, it is still a challenge to controllably regulate the selectivity of N-methylation using heterogeneous catalysts without the use of base. Herein, we developed a series of Pd/Zn(Al)O catalysts with abundant basic sites, and the selectivity of N-methylation was controlled by a heterogeneous Pd/Zn(Al)O catalyst with a Zn/Al ratio of 10 and a Pd loading of 0.4 wt % in the pressure of H2. The experimental results showed that the appropriate basic properties of the catalyst were beneficial to form the desired N-methylated amine. The low loading of Pd in the catalyst was highly dispersed on the support, providing sufficient active sites. These were attributed to the Zn vacancies formed by Al-doped Zn, which were beneficial to form the highly active and stable Pd sites. Furthermore, a series of amines and nitrobenzenes with different functional groups were well tolerated for the selective synthesis of N-methylated amines in the absence of base.

8.
Virus Genes ; 59(1): 91-99, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36258144

RESUMO

A multiplex qPCR assay was developed to simultaneously detect duck circovirus (DuCV), duck Tembusu virus (DTMUV), Muscovy duck reovirus (MDRV), and novel duck reovirus (NDRV), but it did not amplify other viruses, including duck virus enteritis (DVE), infectious bursal disease virus (IBDV), avian reovirus (ARV), H5 avian influenza virus (H5 AIV), H7 avian influenza virus (H7 AIV), H9 avian influenza virus (H9 AIV), Newcastle disease virus (NDV), and Muscovy duck parvovirus (MDPV), and the detection limit for DuCV, DTMUV, MDRV, and NDRV was 1.51 × 101 copies/µL. The intra- and interassay coefficients of variation were less than 1.54% in the repeatability test with standard plasmid concentrations of 1.51 × 107, 1.51 × 105, and 1.51 × 103 copies/µL. The developed multiple qPCR assay was used to examine 404 clinical samples to verify its practicability. The positivity rates for DuCV, DTMUV, MDRV, and NDRV were 26.0%, 9.9%, 4.0%, and 4.7%, respectively, and the mixed infection rates for DuCV + DTMUV, DuCV + MDRV, DuCV + NDRV, MDRV + NDRV, DTMUV + MDRV, and DTMUV + NDRV were 2.7%, 1.2%, 1.2%, 1.0%, 0.5%, and 0.7%, respectively.


Assuntos
Vírus da Influenza A , Influenza Aviária , Orthoreovirus , Doenças das Aves Domésticas , Animais , Doenças das Aves Domésticas/diagnóstico
9.
Angew Chem Int Ed Engl ; 62(47): e202313343, 2023 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-37798814

RESUMO

High-performance catalysts sufficient to significantly reduce the energy barrier of water activation are crucial in facilitating reactions that are restricted by water dissociation. Herein we present a Cu-Co double-atom catalyst (CuCo-DAC), which possesses a uniform and well-defined CuCoN6 (OH) structure, and works together to promote water activation in silane oxidation. The catalyst achieves superior catalytic performance far exceeding that of single-atom catalysts (SACs). Various functional silanes are converted into silanols with up to 98 % yield and 99 % selectivity. Kinetic studies show that the activation energy of silane oxidation by CuCo-DAC is significantly lower than that of Cu single-atom catalyst (Cu-SAC) and Co single-atom catalyst (Co-SAC). Theoretical calculations demonstrate two different reaction pathways where water splitting is the rate-determining step and it is accelerated by CuCo-DAC, whereas H2 formation is key for its single-atom counterpart.

10.
J Am Chem Soc ; 144(25): 11129-11137, 2022 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-35700394

RESUMO

The hydrophobic internal cavity and hydrophilic external surface of cyclodextrins (CDs) render promising electrochemical applications. Here, we report a comparative and mechanistic study on the use of CD molecules (α-, ß-, and γ-CD) as electrolyte additives for rechargeable Zn batteries. The addition of α-CD in aqueous ZnSO4 solution reduces nucleation overpotential and activation energy of Zn plating and suppresses H2 generation. Computational, spectroscopic, and electrochemical studies reveal that α-CD preferentially adsorbs in parallel on the Zn surface via secondary hydroxyl groups, suppressing water-induced side reactions of hydrogen evolution and hydroxide sulfate formation. Additionally, the hydrophilic exterior surface of α-CD with intense electron density simultaneously facilitates Zn2+ deposition and alleviates Zn dendrite formation. A formulated 3 M ZnSO4 + 10 mM α-CD electrolyte enables homogenous Zn plating/stripping (average Coulombic efficiency ∼ 99.90%) at 1 mA cm-2 in Zn|Cu cells and a considerable capacity retention of 84.20% after 800 cycles in Zn|V2O5 full batteries. This study provides insight into the use of supramolecular macrocycles to modulate and enhance the interface stability and kinetics of metallic anodes for aqueous battery chemistry.


Assuntos
Ciclodextrinas , Ciclodextrinas/química , Eletrodos , Cinética , Água , Zinco
11.
Support Care Cancer ; 30(8): 6451-6462, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35316404

RESUMO

PURPOSE: This systematic review and meta-analysis aimed to explore the predictive value of preoperative handgrip strength on postoperative outcomes in patients with gastrointestinal tumors. METHODS: Databases including Cochrane Library, Pubmed, Embase, Web of Science, and CINAHL Complete were searched for articles published from the establishment of database until August 7, 2021. Two researchers independently screened the literature, extracted the data, and evaluated the quality. RESULTS: Eight studies were included, involving five prospective and three retrospective cohort studies with 2291 participants. The prevalence of preoperative low handgrip strength ranged from 11.8 to 62.7%. Preoperative low handgrip strength was associated with an increased risk of total complications (OR = 2.23, 95%CI = 1.43-3.50), pneumonia (OR = 5.16, 95%CI = 3.17-8.38), ileus (OR = 2.48, 95%CI = 1.09-5.65), and short-term mortality (OR = 7.28, 95%CI = 1.90-27.92). CONCLUSION: This systematic review and meta-analysis indicated that preoperative HGS had important value to predict certain adverse postoperative outcomes among patients with GI tumors. Low handgrip strength criteria, definition of total complications, and country are the potential sources of heterogeneity, and more research are required to test and update these results.


Assuntos
Neoplasias Gastrointestinais , Força da Mão , Neoplasias Gastrointestinais/cirurgia , Humanos , Período Pós-Operatório , Estudos Prospectivos , Estudos Retrospectivos
12.
Physica A ; 596: 127119, 2022 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-35342220

RESUMO

With the COVID-19 pandemic, better understanding of the co-evolution of information and epidemic diffusion networks is important for pandemic-related policies. Using the microscopic Markov chain method, this study proposed an aware-susceptible-infected model (ASI) to explore the effect of information literacy on the spreading process in such multiplex networks. We first introduced a parameter that adjusts the self-protection related execution ability of aware individuals in order to emphasis the importance of protective behaviors compared to awareness in decreasing the infection probability. The model also captures individuals' heterogeneity in their information literacy. Simulation experiments found that the high information-literate individuals are more sensitive to information adoption. In addition, epidemic information can help to suppress the epidemic diffusion only when individuals' abilities of transforming awareness into actual protective behaviors attain a threshold. In communities dominated by highly literate individuals, a larger information literacy gap can improve awareness acquisition and thus help to suppress the epidemic among the whole group. By contrast, in communities dominated by low information-literate individuals, a smaller information literacy gap can better prevent the epidemic diffusion. This study contributes to the literature by revealing the importance of individuals' heterogeneity of information literacy on epidemic spreading in different communities and has implications for how to inform people when a new epidemic disease emerges.

13.
J Environ Sci (China) ; 121: 48-57, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35654515

RESUMO

Excessive livestock grazing degrades grasslands ecosystem stability and sustainability by reducing soil organic matter and plant productivity. However, the effects of grazing on soil cellulolytic fungi, an important indicator of the degradation process for soil organic matter, remain less well understood. Using T-RFLP and sequencing methods, we investigated the effects of grazing on the temporal changes of cellulolytic fungal abundance and community structure in dry steppe soils during the growing months from May to September, on the Tibetan Plateau using T-RFLP and sequencing methods. The results demonstrated that the abundance of soil cellulolytic fungi under grazing treatment changed significantly from month to month, and was positively correlated with dissolved organic carbon (DOC) and soil temperature, but negatively correlated with soil pH. Contrastingly, cellulolytic fungal abundance did not change within the fencing treatment (ungrazed conditions). Cellulolytic fungal community structure changed significantly in the growing months in grazed soils, but did not change in fenced soils. Grazing played a key role in determining the community structure of soil cellulolytic fungi by explaining 8.1% of the variation, while pH and DOC explained 4.1% and 4.0%, respectively. Phylogenetically, the cellulolytic fungi were primarily affiliated with Ascomycota (69.65% in relative abundance) and Basidiomycota (30.35%). Therefore, grazing substantially reduced the stability of soil cellulolytic fungal abundance and community structure, as compared with the fencing treatment. Our finding provides a new insight into the responses of organic matter-decomposing microbes for grassland managements.


Assuntos
Micobioma , Solo , Ecossistema , Solo/química , Microbiologia do Solo , Tibet
14.
J Org Chem ; 86(23): 17274-17281, 2021 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-34806887

RESUMO

An interrupted Pummerer reaction of PhICl2 and sulfoxides was found to in situ generate reactive organosulfenyl chloride, which enabled the intramolecular electrophilic cyclization of 2-alkynylanilines, generating 3-sulfenylated indole with a good to excellent yield under metal-free conditions. One striking feature of the approach is that sulfoxide regeneration can be realized via the oxidation of the formed sulfides by the generated hypervalent iodine species.

15.
Chaos ; 31(6): 061102, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34241307

RESUMO

African swine fever (ASF) is a highly contagious hemorrhagic viral disease of domestic and wild pigs. ASF has led to major economic losses and adverse impacts on livelihoods of stakeholders involved in the pork food system in many European and Asian countries. While the epidemiology of ASF virus (ASFV) is fairly well understood, there is neither any effective treatment nor vaccine. In this paper, we propose a novel method to model the spread of ASFV in China by integrating the data of pork import/export, transportation networks, and pork distribution centers. We first empirically analyze the overall spatiotemporal patterns of ASFV spread and conduct extensive experiments to evaluate the efficacy of a number of geographic distance measures. These empirical analyses of ASFV spread within China indicate that the first occurrence of ASFV has not been purely dependent on the geographical distance from existing infected regions. Instead, the pork supply-demand patterns have played an important role. Predictions based on a new distance measure achieve better performance in predicting ASFV spread among Chinese provinces and thus have the potential to enable the design of more effective control interventions.


Assuntos
Vírus da Febre Suína Africana , Febre Suína Africana , Febre Suína Africana/epidemiologia , Animais , Ásia , China/epidemiologia , Sus scrofa , Suínos
16.
Foodborne Pathog Dis ; 18(10): 727-732, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-33970016

RESUMO

Proteus mirabilis is an opportunistic human pathogen. In this study, a novel SXT/R391 integrative and conjugative element (ICE), named ICEPmiChnS012, was identified in the multidrug-resistant P. mirabilis strain S012 that was isolated from retail chicken in China. Whole genome sequencing revealed that ICEPmiChnS012 carried 22 resistance genes including aac(6')-Ib-cr, fosA3, blaOXA-1, blaCTX-M-65, and blaHMS-1. ICEPmiChnS012 harbored 10 copies of IS26 and IS26-mediated genetic new rearrangements caused variations in HS4 region. To our knowledge, an unusual gene cassette array dfrA1-ereA1-aadA2 was found in P. mirabilis in this study for the first time. And this is the first report of identification of aph3-VI and blaHMS-1 in VRIII region in P. mirabilis. The conjugation experiments proved that ICEPmiChnS012 could be transferred to Escherichia coli EC600 through conjugation. These findings demonstrated that ICEPmiChnS012 was a special ICE that carried the largest number of antimicrobial resistance genes in the family of SXT/R391 ICEs. This element could serve as an important vehicle for the dissemination of antibiotic resistance genes and should receive great concern.


Assuntos
Conjugação Genética , Proteus mirabilis , Antibacterianos/farmacologia , Escherichia coli/genética , Humanos , Proteus mirabilis/genética , Sequenciamento Completo do Genoma
17.
Opt Express ; 28(17): 25250-25262, 2020 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-32907050

RESUMO

Femtosecond (fs) laser-thin film interaction is one of the most practical methods for fabricating functional nanostructures. However, the details of the interaction mechanism remain unclear. In this study, we demonstrate an abnormal ablation effect on nanofilms by using a tightly focused single fs laser pulse. After the irradiation of a single Gaussian-shaped femtosecond laser pulse, a molten micro/nanopatch at the irradiated central high-power zone is isolated from the surrounding film. The confined localized threshold effect is proposed as the main mechanism for the phase isolation. With this effect, the high refractive index dielectric Ge2Sb2Te5 crystal nanostructures can be fabricated by directed dewetting of the isolated molten micro/nanopatch on Si substrates. After the laser irradiation, the central isolated liquid through an amorphous GST film is transformed into a crystalline state after resolidification. The isolated central micro/nanopatch size can be controlled by the focused spot size and pulse energy, so that the morphologies (size, geometrical morphology, and distribution) of GST nanostructures can be flexibly modulated. Furthermore, separated solid and liquid phase states detected using spatial-temporal-resolved microscopy validates the crucial role of the confined-localized threshold effect in the dewetting effect based on the separated liquid phase.

18.
Analyst ; 145(11): 4004-4011, 2020 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-32347240

RESUMO

Methyl jasmonate (MeJA) and its free-acid form, jasmonic acid (JA), collectively referred to as jasmonates (JAs), are natural plant growth regulators that are widely present in higher plants. Simultaneous detection of JA and MeJA in plant samples is of significance and is a great challenging issue. In this study, coupling with two extraction methods, a sensitive monoclonal antibody (mAb) based enzyme-linked immunosorbent assay (ELISA) for simultaneous detection of JA and MeJA in plant samples was developed. The JA-bovine serum albumin (BSA) conjugate was used as an immunogen for the production of mAb. As the produced mAb exhibited higher recognition ability towards MeJA than towards JA, ELISA was established using MeJA as the standard. Under optimal experimental conditions, the IC50 and LOD values of ELISA for MeJA were 2.02 ng mL-1 and 0.20 ng mL-1, respectively. In the first extraction method, MeJA in plant samples was evaporated and only JA was extracted. In the second extraction method, both JA and MeJA were extracted. After methylation, JA in the extracts was converted into MeJA, and the whole MeJA in the extracts was measured by ELISA. Plant samples including the leaves of Salvia splendens, the flowers of Salvia splendens and the fruit of grapes were collected. JA and MeJA in these samples were detected by the proposed ELISA. It was found that the concentrations of JA in these three plant samples were about 3-5 times higher than those of MeJA in those samples. ELISA was also confirmed by HPLC. There was a good correlation between ELISA and HPLC.


Assuntos
Acetatos/análise , Anticorpos Monoclonais/imunologia , Ciclopentanos/análise , Oxilipinas/análise , Reguladores de Crescimento de Plantas/análise , Acetatos/imunologia , Acetatos/isolamento & purificação , Animais , Ciclopentanos/imunologia , Ciclopentanos/isolamento & purificação , Ensaio de Imunoadsorção Enzimática , Feminino , Flores/química , Frutas/química , Camundongos Endogâmicos BALB C , Oxilipinas/imunologia , Oxilipinas/isolamento & purificação , Reguladores de Crescimento de Plantas/imunologia , Reguladores de Crescimento de Plantas/isolamento & purificação , Folhas de Planta/química , Salvia/química , Extração em Fase Sólida , Vitis/química
19.
Arch Insect Biochem Physiol ; 104(1): e21659, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31976584

RESUMO

Ferritin is a ubiquitous and conserved iron storage protein that plays a significant role in host detoxification, iron storage, and immune response. Although ferritin has been studied in many species, little is known about its role in the Eri-silkworm (Samia cynthia ricini). In this study, the ferritin light-chain subunit gene, named ScFerLCH, was identified from S. c. ricini. The full-length gene, ScFerLCH, was 1,155 bp and encoded a protein consisting of 231 amino acids with a deduced molecular weight of 26.38 kDa. Higher ScFerLCH expression levels were found in the midgut, silk gland, and fat body by quantitative reverse-transcription polymerase chain reaction and western blot analysis. Injection of Staphylococcus aureus and Pseudomonas aeruginosa could induce upregulation of ScFerLCH in the hemolymph, fat body, and midgut, indicating that ScFerLCH may contribute to the host defense against invading pathogens. In addition, the native ferritin protein was isolated from S. c. ricini by native polyacrylamide gel electrophoresis and its two subunits, ferritin heavy-chain subunit (ScFerHCH) and ferritin light-chain subunit (ScFerLCH), were identified by mass spectrometry. Specifically, we found that recombinant ferritin subunits could self-assemble into a protein complex in vitro; moreover, both recombinant subunits and the protein complex were found to bind different bacteria, including Escherichia coli, P. aeruginosa, S. aureus, and Bacillus subtilis. However, bactericidal tests showed that the protein complex could not inhibit the growth of bacteria directly. Taken together, our results suggest that ScFerritin might play an important role in mediating molecular interaction with pathogens.


Assuntos
Ferritinas/química , Mariposas/genética , Mariposas/microbiologia , Sequência de Aminoácidos , Animais , Bactérias/imunologia , Ferritinas/genética , Ferritinas/metabolismo , Imunidade Inata , Proteínas de Insetos , Ferro/metabolismo , Larva/genética , Larva/metabolismo , Larva/microbiologia , Mariposas/imunologia , Mariposas/metabolismo
20.
J Sep Sci ; 43(16): 3349-3358, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32506783

RESUMO

The citrus herbs have proved their important medicinal and nutritional values as medicine-food dual-purpose herbs, functional foods, or medical herbs in China. In this study, phytochemicals and antioxidant activity among ten typical citrus herbs (ethanol extracts) were investigated comprehensively. The major ingredients and their contents were analyzed by high-resolution mass spectrometry, and the differences of typical fragment ions between flavanone-7-O-rutinoside(s) and flavanone-7-O-neohesperidoside(s) were discriminated properly in negative electrospray ionization mode. Total polyphenols, total flavonoids, 1,1-diphenyl-2-picrylhydrazyl, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid), and ferric reducing antioxidant power tests were performed, which indicated their beneficial values and antioxidant effects. The medicine-food dual-purpose herbs including Chenpi, Juluo, Daidaihua, Huajuhong, Xiangyuan, and Foshou exhibited antioxidant capacities significantly by decreasing intracellular reactive oxygen species intensity (P < 0.01), enhancing superoxide dismutase, catalase, and glutathione peroxidase activities (P < 0.01) in H2 O2 -induced RIN-m5F cells. Moreover, the functional foods Zhishi, Zhiqiao, and Qingpi showed moderate antioxidant bioactivity, while the medical herb Juhe showed weak antioxidant bioactivity, which were consistent with the multivariate analysis of their major flavonoids. The study provided a new sight for the chemical differentiation and practical application of citrus herbs as medicine-food dual-purpose herbs, functional foods, or medical herbs.


Assuntos
Antioxidantes/farmacologia , Citrus/química , Medicamentos de Ervas Chinesas/farmacologia , Extratos Vegetais/farmacologia , Animais , Antioxidantes/química , Antioxidantes/metabolismo , Benzotiazóis/antagonistas & inibidores , Compostos de Bifenilo/antagonistas & inibidores , Linhagem Celular , Técnicas de Química Analítica , Físico-Química , China , Cromatografia Líquida de Alta Pressão , Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/metabolismo , Peróxido de Hidrogênio/antagonistas & inibidores , Metabolômica , Picratos/antagonistas & inibidores , Extratos Vegetais/química , Extratos Vegetais/metabolismo , Ratos , Espectrometria de Massas por Ionização por Electrospray , Ácidos Sulfônicos/antagonistas & inibidores
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