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1.
Phys Rev Lett ; 132(18): 187202, 2024 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-38759185

RESUMO

Constructing a highly localized wave field by means of bound states in the continuum (BICs) promotes enhanced wave-matter interaction and offers approaches to high-sensitivity devices. Elastic waves can carry complex polarizations and thus differ from electromagnetic waves and other scalar mechanical waves in the formation of BICs, which is yet to be fully explored and exploited. Here, we report the investigation of local resonance modes supported by a Lamb waveguide side-branched with two pairs of resonant pillars and show the emergence of two groups of elastic BICs with different polarizations or symmetries. Particularly, the two groups of BICs exhibit distinct responses to external perturbations, based on which a label-free sensing scheme with enhanced-sensitivity is proposed. Our study reveals the rich properties of BICs arising from the complex wave dynamics in elastic media and demonstrates their unique functionality for sensing and detection.

2.
Int J Psychol ; 2024 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-39425575

RESUMO

Understanding the differential strength of effects in the presence of a third variable, known as a moderation effect, is a common research goal in many psychological and behavioural science fields. If structural equation modelling is applied to test effects of interest, the investigation of differential strength of effects will typically ask how parameters of a latent variable model are influenced by categorical or continuous moderators, such as age, socio-economic status, personality traits, etc. Traditional approaches to continuous moderators in SEMs predominantly address linear moderation effects, risking the oversight of nonlinear effects. Moreover, some approaches have methodological limitations, for example, the need to categorise moderators or to pre-specify parametric forms of moderation. This tutorial introduces local structural equation modelling (LSEM) in a non-technical way. LSEM is a nonparametric approach that allows the analysis of nonlinear moderation effects without the above-mentioned limitations. Using an empirical dataset, we demonstrate the implementation of LSEM through the R-sirt package, emphasising its versatility in both exploratory analysis of nonlinear moderation without prior knowledge and confirmatory testing of hypothesised moderation functions. The tutorial also addresses common modelling issues and extends the discussion to different application scenarios, demonstrating its flexibility.

3.
J Am Chem Soc ; 145(4): 2052-2057, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36649211

RESUMO

The development of metal halide perovskite/perovskite heterostructures is hindered by rapid interfacial halide diffusion leading to mixed alloys rather than sharp interfaces. To circumvent this outcome, we developed an ion-blocking layer consisting of single-layer graphene (SLG) deposited between the metal halide perovskite layers and demonstrated that it effectively blocks anion diffusion in a CsPbBr3/SLG/CsPbI3 heterostructure. Spatially resolved elemental analysis and spectroscopic measurements demonstrate the halides do not diffuse across the interface, whereas control samples without the SLG show rapid homogenization of the halides and loss of the sharp interface. Ultraviolet photoelectron spectroscopy, DFT calculations, and transient absorbance spectroscopy indicate the SLG has little electronic impact on the individual semiconductors. In the CsPbBr3/SLG/CsPbI3, we find a type I band alignment that supports transfer of photogenerated carriers across the heterointerface. Light-emitting diodes (LEDs) show electroluminescence from both the CsPbBr3 and CsPbI3 layers with no evidence of ion diffusion during operation. Our approach provides opportunities to design novel all-perovskite heterostructures to facilitate the control of charge and light in optoelectronic applications.

4.
Dev Psychopathol ; 35(3): 1130-1146, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-34766903

RESUMO

This research aims to investigate the salience of mothers' emotional expressivity and its links with adolescents' emotional wellbeing and expressivity in an urban society endorsing more individualism and a rural society ascribing to more collectivism. By comparing Chinese urban (N = 283, M age = 14.13) and rural (N = 247, M age = 14.09) adolescents, this research found that urban mothers' expression of positive-dominant and positive-submissive emotions (PD and PS) were more common while expression of negative-dominant (ND) emotions was less common than rural mothers'. PD and PS had significant links with urban and rural adolescents' increased emotional expressivity and self-esteem, however, only significantly related to urban adolescents' decreased depression but not with rural adolescents'. ND had significant links with both urban and rural adolescents' expression of negative emotions, however, only significantly correlated with urban adolescents' less level of self-esteem and rural adolescents' more expression of positive emotions. No significant difference was found in the salience of urban and rural mothers' expression of negative-submissive (NS) emotions, which positively related to both urban and rural adolescents' depression and emotional expressivity. Moreover, we found that adolescents' emotional wellbeing (i.e., self-esteem and depression) mediated the relationship between mothers' emotional expressivity and adolescents' expressivity in both societies. Overall, the study findings document that the salience of mothers' emotional expressivity and its relations with adolescents' emotional adjustment differ between urban and rural societies.


Assuntos
Relações Mãe-Filho , Mães , Feminino , Humanos , Adolescente , Mães/psicologia , Relações Mãe-Filho/psicologia , Emoções , Ajustamento Emocional , Autoimagem
5.
Sensors (Basel) ; 23(15)2023 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-37571782

RESUMO

Intelligent transportation systems (ITS) urgently need to realize vehicle identification, dynamic monitoring, and traffic flow monitoring under high-speed motion conditions. Vehicle tracking based on radio frequency identification (RFID) and electronic vehicle identification (EVI) can obtain continuous observation data for a long period of time, and the acquisition accuracy is relatively high, which is conducive to the discovery of rules. The data can provide key information for urban traffic decision-making research. In this paper, an RFID tag motion trajectory tracking method based on RF multiple features for ITS is proposed to analyze the movement trajectory of vehicles at important checkpoints. The method analyzes the accurate relationship between the RSSI, phase differences, and driving distances of the tag. It utilizes the information weight method to obtain the weights of multiple RF characteristics at different distances. Then, it calculates the center point of the common area where the vehicle may move under multi-antenna conditions, confirming the actual position of the vehicle. The experimental results show that the average positioning error of moving RFID tags based on dual-frequency signal phase differences and RSSI is less than 17 cm. This method can provide real-time, high-precision vehicle positioning and trajectory tracking solutions for ITS application scenarios such as parking guidance, unmanned vehicle route monitoring, and vehicle lane change detection.

6.
Behav Res Methods ; 55(2): 867-882, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-35501531

RESUMO

Enfacement illusions are traditionally elicited by visuo-tactile stimulation, but more active paradigms become possible through the usage of virtual reality techniques. For instance, virtual mirrors have been recently proposed to induce enfacement by visuo-motor stimulation. In a virtual mirror experiment, participants interact with an avatar that imitates their facial movements. The active control over the avatar greatly enhances the sense of agency, which is an important ingredient for successful enfacement illusion induction. Due to technological challenges, most virtual mirrors so far were limited to the imitation of the participant's head pose, i.e., its location and rotation. However, stronger experiences of agency can be expected by an increase in the avatar's mimicking abilities. We here present a new open-source framework for virtual mirror experiments, which we call the Open Virtual Mirror Framework (OVMF). The OVMF can track and imitate a large range of facial movements, including pose and expressions. It has been designed to run on standard computer hardware and easily interfaces with existing toolboxes for psychological experimentation, while satisfying the requirement of a tightly controlled experimental setup. Further, it is designed to enable convenient extension of its core functionality such that it can be flexibly adjusted to many different experimental paradigms. We demonstrate the usage of the OVMF and experimentally validate its ability to elicit experiences of agency over an avatar, concluding that the OVMF can serve as a reference for future experiments and that it provides high potential to stimulate new directions in enfacement research and beyond.


Assuntos
Ilusões , Realidade Virtual , Humanos , Expressão Facial , Ilusões/fisiologia , Movimento/fisiologia
7.
Zhongguo Zhong Yao Za Zhi ; 48(18): 4902-4907, 2023 Sep.
Artigo em Zh | MEDLINE | ID: mdl-37802832

RESUMO

Malaria, one of the major global public health events, is a leading cause of mortality and morbidity among children and adults in tropical and subtropical regions(mainly in sub-Saharan Africa), threatening human health. It is well known that malaria can cause various complications including anemia, blackwater fever, cerebral malaria, and kidney damage. Conventionally, cardiac involvement has not been listed as a common reason affecting morbidity and mortality of malaria, which may be related to ignored cases or insufficient diagnosis. However, the serious clinical consequences such as acute coronary syndrome, heart failure, and malignant arrhythmia caused by malaria have aroused great concern. At present, antimalarials are commonly used for treating malaria in clinical practice. However, inappropriate medication can increase the risk of cardiovascular diseases and cause severe consequences. This review summarized the research advances in the cardiovascular complications including acute myocardial infarction, arrhythmia, hypertension, heart failure, and myocarditis in malaria. The possible mechanisms of cardiovascular diseases caused by malaria were systematically expounded from the hypotheses of cell adhesion, inflammation and cytokines, myocardial apoptosis induced by plasmodium toxin, cardiac injury secondary to acute renal failure, and thrombosis. Furthermore, the effects of quinolines, nucleoprotein synthesis inhibitors, and artemisinin and its derivatives on cardiac structure and function were summarized. Compared with the cardiac toxicity of quinolines in antimalarial therapy, the adverse effects of artemisinin-derived drugs on heart have not been reported in clinical studies. More importantly, the artemisinin-derived drugs demonstrate favorable application prospects in the prevention and treatment of cardiovascular diseases, and are expected to play a role in the treatment of malaria patients with cardiovascular diseases. This review provides reference for the prevention and treatment of malaria-related cardiovascular complications as well as the safe application of antimalarials.


Assuntos
Antimaláricos , Artemisininas , Doenças Cardiovasculares , Insuficiência Cardíaca , Malária Cerebral , Quinolinas , Criança , Adulto , Humanos , Antimaláricos/farmacologia , Doenças Cardiovasculares/tratamento farmacológico , Artemisininas/farmacologia , Malária Cerebral/tratamento farmacológico , Insuficiência Cardíaca/tratamento farmacológico , Arritmias Cardíacas/tratamento farmacológico
8.
Nat Mater ; 20(4): 518-524, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33398117

RESUMO

It is commonly assumed that charge-carrier transport in doped π-conjugated polymers is dominated by one type of charge carrier, either holes or electrons, as determined by the chemistry of the dopant. Here, through Seebeck coefficient and Hall effect measurements, we show that mobile electrons contribute substantially to charge-carrier transport in π-conjugated polymers that are heavily p-doped with strong electron acceptors. Specifically, the Seebeck coefficient of several p-doped polymers changes sign from positive to negative as the concentration of the oxidizing agents FeCl3 or NOBF4 increase, and Hall effect measurements for the same p-doped polymers reveal that electrons become the dominant delocalized charge carriers. Ultraviolet and inverse photoelectron spectroscopy measurements show that doping with oxidizing agents results in elimination of the transport gap at high doping concentrations. This approach of heavy p-type doping is demonstrated to provide a promising route to high-performance n-type organic thermoelectric materials.

9.
BMC Public Health ; 22(1): 398, 2022 02 25.
Artigo em Inglês | MEDLINE | ID: mdl-35216568

RESUMO

BACKGROUND: Negative emotions among employees have become a public problem that increase the risk of developing the disease and accelerate its progression. This study aimed to investigate the status and influencing factors of negative emotions among young employees in center of disease control and prevention. METHODS: Participants included 6099 employees aged 40 or below in center of disease control and prevention (CDC) of 32 province of China were interviewed by online questionnaire survey. The emotional conditions of anxiety and depression, and their influencing factors were analyzed. RESULTS: A total of 5353 valid questionnaires were collected with the recovery rate of 87.77%. 2871 cases of young employees had different degrees of negative emotions at work, accounting for about 53.60%. Regression analysis showed that gender, professional title, educational level, job satisfaction, chronic diseases, daily sleep duration, average weekly overtime, physical activity time, and sugary beverage intake were the influencing factors of negative emotions (P < 0.05). Male, primary and below, never working overtime and daily physical activity time more than 30 min were protective factors for negative emotions (OR vale were 0.79, 0.68, 0.39 and 0.63, respectively, P < 0.05). Bachelor degree or above, poor job satisfaction, chronic disease, daily sleep duration less than 8 h and drinking one to three sugary drinks a week were the risk factors for negative emotion (OR vale were1.21, 4.32, 2.16, 2.75 and 1.20, respectively, P < 0.05). CONCLUSION: Due to the influence of work pressure, lifestyle, chronic diseases and other factors, young employees in CDC have a certain degree of negative emotions at work, which should be paid enough attention. Meanwhile, corresponding measures should be taken according to the influencing factors to reduce the occurrence of negative emotions.


Assuntos
Emoções , Satisfação no Emprego , Ansiedade/epidemiologia , Transtornos de Ansiedade , Humanos , Masculino , Inquéritos e Questionários
10.
Angew Chem Int Ed Engl ; 61(11): e202117303, 2022 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-35060264

RESUMO

Defects and energy offsets at the bulk and heterojunction interfaces of perovskite are detrimental to the efficiency and stability of perovskite solar cells (PSCs). Herein, we designed an amphiphilic π-conjugated ionic compound (QAPyBF4 ), implementing simultaneous defects passivation and interface energy level alignments. The p-type conjugated cations passivated the surface trap states and optimized energy alignment at the perovskite/hole transport layer. The highly electronegative [BF4 ]- enriched at the SnO2 interface featured desired band alignment due to the dipole moment of this interlayer. The planar n-i-p PSC had an efficiency of 23.1 % with Voc of 1.2 V. Notably, the synergy effect elevated the intrinsic endothermic decomposition temperature of the perovskite. The modified devices showed excellent long-term thermal (85 °C) and operational stability at the maximum power point for 1000 h at 45 °C under continuous one-sun illumination with no appreciable efficiency loss.

11.
Opt Express ; 29(22): 35776-35791, 2021 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-34809005

RESUMO

Dissipative structures are the result of spontaneous symmetry breaking in a dynamic open system, which is induced by either the nonlinear effect or loss fluctuations. While optical temporal dissipative solitons in nonlinear Kerr cavities has been widely studied, their operation is limited to the red-detuned regime. Here, we demonstrate an emergent dissipative soliton state in optical nonlinear cavities in the presence of loss fluctuations, which is accessible by self-evolution of the system on resonance. Based on a modified dissipative and Kerr-nonlinear cavity model, we numerically investigate the effect of the loss modulation on the intracavity field pattern, and in transmission observe a single and bright soliton pulse state at the zero detuning. The effect of the optical saturable absorption is also numerically investigated, which is recognized as an effective approach to the transient loss fluctuation in the cavity. The estimated power efficiency of the resonant bright soliton can be higher than that of the conventional dissipative Kerr soliton, which is determined by the loss modulation depth and the pump intensity. The self-starting soliton state on system's resonance is potentially of wide interest, which physically contributes to insights of the temporal structure formation in dissipative cavities. On application aspect, it may constitute a way to the generation of ultra-fast soliton pulse trains as well as the generation of soliton micro-combs.

12.
J Sex Marital Ther ; 47(6): 571-590, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33988489

RESUMO

Sexual objectification is a common pornographic theme. Research shows that sexual objectification leads to the expression of aggressive attitudes and behaviors toward women. Based on a survey study of 320 male participants, this study re-conceptualizes sexual objectification in terms of two forms of dehumanization. Evidence suggests men's pornography use is positively associated with both forms, but mechanistic dehumanization of women is more associated with aggressive attitudes while animalistic dehumanization is more associated with aggressive behaviors. Findings indicate how objectifying pornography use may relate to aggressive attitudes and behaviors and inform the future education campaigns and interventions to reduce sexual aggression.


Assuntos
Agressão , Literatura Erótica , Atitude , Desumanização , Feminino , Humanos , Masculino , Comportamento Sexual
13.
Molecules ; 26(21)2021 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-34771064

RESUMO

Ginseng (Panax ginseng C.A. Mey.) is a precious Chinese traditional medicine, for which ginsenosides are the most important medicinal ingredients. Cytochrome P450 enzymes (CYP450) and their primary redox molecular companion NADPH cytochrome P450 reductase (CPR) play a key role in ginsenoside biosynthesis pathway. However, systematic studies of CPR genes in ginseng have not been reported. Numerous studies on ginsenoside synthesis biology still use Arabidopsis CPR (AtCPR1) as a reductase. In this study, we isolated two CPR genes (PgCPR1, PgCPR2) from ginseng adventitious roots. Phylogenetic tree analysis showed that both PgCPR1 and PgCPR2 are grouped in classⅡ of dicotyledonous CPR. Enzyme experiments showed that recombinant proteins PgCPR1, PgCPR2 and AtCPR1 can reduce cytochrome c and ferricyanide with NADPH as the electron donor, and PgCPR1 had the highest enzymatic activities. Quantitative real-time PCR analysis showed that PgCPR1 and PgCPR2 transcripts were detected in all examined tissues of Panax ginseng and both showed higher expression in stem and main root. Expression levels of the PgCPR1 and PgCPR2s were both induced after a methyl jasmonate (MeJA) treatment and its pattern matched with ginsenoside accumulation. The present investigation suggested PgCPR1 and PgCPR2 are associated with the biosynthesis of ginsenoside. This report will assist in future CPR family studies and ultimately improving ginsenoside production through transgenic engineering and synthetic biology.


Assuntos
NADPH-Ferri-Hemoproteína Redutase/genética , Panax/enzimologia , Sequência de Aminoácidos , Clonagem Molecular , Biologia Computacional , Regulação da Expressão Gênica de Plantas/genética , Modelos Moleculares , NADPH-Ferri-Hemoproteína Redutase/metabolismo , Filogenia
14.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 38(5): 995-1002, 2021 Oct 25.
Artigo em Zh | MEDLINE | ID: mdl-34713668

RESUMO

Motor imagery (MI), motion intention of the specific body without actual movements, has attracted wide attention in fields as neuroscience. Classification algorithms for motor imagery electroencephalogram (MI-EEG) signals are able to distinguish different MI tasks based on the physiological information contained by the EEG signals, especially the features extracted from them. In recent years, there have been some new advances in classification algorithms for MI-EEG signals in terms of classifiers versus machine learning strategies. In terms of classifiers, traditional machine learning classifiers have been improved by some researchers, deep learning and Riemannian geometry classifiers have been widely applied as well. In terms of machine learning strategies, ensemble learning, adaptive learning, and transfer learning strategies have been utilized to improve classification accuracies or reach other targets. This paper reviewed the progress of classification algorithms for MI-EEG signals, summarized and evaluated the existing classifiers and machine learning strategies, to provide new ideas for developing classification algorithms with higher performance.


Assuntos
Interfaces Cérebro-Computador , Algoritmos , Eletroencefalografia , Imagens, Psicoterapia , Imaginação , Aprendizado de Máquina
15.
Nat Mater ; 18(12): 1327-1334, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31527809

RESUMO

Precise doping of organic semiconductors allows control over the conductivity of these materials, an essential parameter in electronic applications. Although Lewis acids have recently shown promise as dopants for solution-processed polymers, their doping mechanism is not yet fully understood. In this study, we found that B(C6F5)3 is a superior dopant to the other Lewis acids investigated (BF3, BBr3 and AlCl3). Experiments indicate that Lewis acid-base adduct formation with polymers inhibits the doping process. Electron-nuclear double-resonance and nuclear magnetic resonance experiments, together with density functional theory, show that p-type doping occurs by generation of a water-Lewis acid complex with substantial Brønsted acidity, followed by protonation of the polymer backbone and electron transfer from a neutral chain segment to a positively charged, protonated one. This study provides insight into a potential path for protonic acid doping and shows how trace levels of water can transform Lewis acids into powerful Brønsted acids.

16.
J Acoust Soc Am ; 148(3): 1636, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33003853

RESUMO

Zero index metamaterials have shown the ability to achieve total transmission or reflection by embedding particular defects with various effective parameters. Here, we present that tunable sound transmission can be realized by configuring a subwavelength-sized dopant inside zero index acoustic metamaterials. Despite its small spatial signature, the dopant is able to strongly interact with the acoustic waves inside the whole zero index metamaterials. It is due to the essence of the zero effective index that can homogenize the pressure field within the metamaterials. Sound transmission can thus be fully switched on and off by adjusting the dopant's surface impedance. A simple rectangular cavity with varied lengths is proposed to provide the required impedance boundary. Our model of correlating the dopant design with sound transmission performance is validated theoretically and numerically. We further demonstrate the utilization of the proposed design to effectively modulate the sound focusing effect. Such a dopant-modulated sound transmission scheme, with its simplicity and capability, has potential applications in fields like noise control and ultrasonography.

17.
J Nanobiotechnology ; 17(1): 64, 2019 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-31084611

RESUMO

BACKGROUND: Age-related macular degeneration (AMD) is a leading cause of severe visual deficits and blindness. Meanwhile, there is convincing evidence implicating oxidative stress, inflammation, and neovascularization in the onset and progression of AMD. Several studies have identified berberine hydrochloride and chrysophanol as potential treatments for ocular diseases based on their antioxidative, antiangiogenic, and anti-inflammatory effects. Unfortunately, their poor stability and bioavailability have limited their application. In order to overcome these disadvantages, we prepared a compound liposome system that can entrap these drugs simultaneously using the third polyamidoamine dendrimer (PAMAM G3.0) as a carrier. RESULTS: PAMAM G3.0-coated compound liposomes exhibited appreciable cellular permeability in human corneal epithelial cells and enhanced bio-adhesion on rabbit corneal epithelium. Moreover, coated liposomes greatly improved BBH bioavailability. Further, coated liposomes exhibited obviously protective effects in human retinal pigment epithelial cells and rat retinas after photooxidative retinal injury. Finally, administration of P-CBLs showed no sign of side effects on ocular surface structure in rabbits model. CONCLUSIONS: The PAMAM G3.0-liposome system thus displayed a potential use for treating various ocular diseases.


Assuntos
Antioxidantes/farmacocinética , Dendrímeros/química , Olho/efeitos dos fármacos , Lipossomos/química , Poliaminas/química , Administração Oftálmica , Animais , Antioxidantes/administração & dosagem , Antioxidantes/efeitos adversos , Transporte Biológico , Linhagem Celular , Córnea/citologia , Liberação Controlada de Fármacos , Células Epiteliais/efeitos dos fármacos , Fluoresceína-5-Isotiocianato/química , Corantes Fluorescentes/química , Humanos , Lipossomos/administração & dosagem , Lipossomos/efeitos adversos , Masculino , Imagem Óptica/métodos , Estresse Oxidativo/efeitos dos fármacos , Tamanho da Partícula , Coelhos , Ratos , Ratos Sprague-Dawley , Propriedades de Superfície
18.
Int J Mol Sci ; 20(9)2019 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-31064108

RESUMO

The MYB transcription factor family members have been reported to play different roles in plant growth regulation, defense response, and secondary metabolism. However, MYB gene expression has not been reported in Panax ginseng. In this study, we isolated a gene from ginseng adventitious root, PgMYB2, which encodes an R2R3-MYB protein. Subcellular localization revealed that PgMYB2 protein was exclusively detected in the nucleus of Allium cepa epidermis. The highest expression level of PgMYB2 was found in ginseng root and it was significantly induced by plant hormones methyl jasmonate (MeJA). Furthermore, the binding interaction between PgMYB2 protein and the promoter of dammarenediol synthase (DDS) was found in the yeast strain Y1H Gold. Moreover, the electrophoretic mobility shift assay (EMSA) identified the binding site of the interaction and the results of transiently overexpressing PgMYB2 in plants also illustrated that it may positively regulate the expression of PgDDS. Based on the key role of PgDDS gene in ginsenoside synthesis, it is reasonable to believe that this report will be helpful for the future studies on the MYB family in P. ginseng and ultimately improving the ginsenoside production through genetic and metabolic engineering.


Assuntos
Alquil e Aril Transferases/genética , Regulação da Expressão Gênica de Plantas , Panax/genética , Fatores de Transcrição/metabolismo , Acetatos/farmacologia , Alquil e Aril Transferases/metabolismo , Ciclopentanos/farmacologia , Oxilipinas/farmacologia , Panax/efeitos dos fármacos , Panax/enzimologia , Regiões Promotoras Genéticas , Fatores de Transcrição/genética
19.
Phys Rev Lett ; 120(12): 124502, 2018 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-29694065

RESUMO

Exploring the concept of non-Hermitian Hamiltonians respecting parity-time symmetry with classical wave systems is of great interest as it enables the experimental investigation of parity-time-symmetric systems through the quantum-classical analogue. Here, we demonstrate unidirectional wave vector manipulation in two-dimensional space, with an all passive acoustic parity-time-symmetric metamaterials crystal. The metamaterials crystal is constructed through interleaving groove- and holey-structured acoustic metamaterials to provide an intrinsic parity-time-symmetric potential that is two-dimensionally extended and curved, which allows the flexible manipulation of unpaired wave vectors. At the transition point from the unbroken to broken parity-time symmetry phase, the unidirectional sound focusing effect (along with reflectionless acoustic transparency in the opposite direction) is experimentally realized over the spectrum. This demonstration confirms the capability of passive acoustic systems to carry the experimental studies on general parity-time symmetry physics and further reveals the unique functionalities enabled by the judiciously tailored unidirectional wave vectors in space.

20.
Acta Biochim Biophys Sin (Shanghai) ; 50(11): 1094-1103, 2018 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-30321253

RESUMO

Cytochromes P450 (CYP450s), a superfamily of mono-oxygenases, are essential to generate highly functionalized secondary metabolites in plants and contribute to the diversification of specialized triterpenoid biosynthesis in eudicots. However, screening and identifying the exact CYP450 genes in ginsenoside biosynthesis is extremely challenging due to existence of large quantities of members in CYP450 superfamily. Therefore, to screen the CYP450 genes involved in ginsenoside biosynthesis, transcriptome dataset of Panax ginseng was created in our previous work using the technique of the next-generation sequencing. On the basis of bioinformatics analysis, 16 putative CYP450 genes with significant differential expression were screened from the dataset and submitted to GenBank, in which 11 of them have been cloned. Methyl jasmonate (MeJA) was used as an elicitor to analyze the expression profiles of candidate CYP450 genes by quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR). The results of qRT-PCR analysis revealed that the expression of some CYP450 genes were strongly induced by MeJA and showed different transcription levels at different treatment time points. Homology analysis indicated that each putative CYP450 protein of P. ginseng has a conserved domain consisting of E-E-R-F-P-R-G. The CYP450 genes were screened and cloned here to enrich the resources of CYP450 genes, and the results of bioinformatics analysis provided a foundation to further identify the function of CYP450s involved in ginsenoside biosynthesis. Furthermore, this study facilitated the construction of microbial cell factories for increasing the production of ginsenosides by means of metabolic engineering.


Assuntos
Acetatos/farmacologia , Ciclopentanos/farmacologia , Sistema Enzimático do Citocromo P-450/genética , Oxilipinas/farmacologia , Panax/genética , Proteínas de Plantas/genética , Transcriptoma/efeitos dos fármacos , Sistema Enzimático do Citocromo P-450/metabolismo , Perfilação da Expressão Gênica/métodos , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Ginsenosídeos/biossíntese , Isoenzimas/genética , Isoenzimas/metabolismo , Panax/metabolismo , Reguladores de Crescimento de Plantas/farmacologia , Proteínas de Plantas/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa
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