Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 6 de 6
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Adv Sci (Weinh) ; 9(32): e2203927, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36156466

RESUMO

The explosion of mobile data from the internet of things (IoT) is leading to the emergence of 5G technology with dramatic frequency band expansion and efficient band allocations. Along with this, the demand for high-performance filters for 5G radio frequency (RF) front-ends keeps growing. The most popular 5G filters are constructed by piezoelectric resonators based on AlN semiconductor. However, AlN possesses a piezoelectric constant d33 lower than 5 pm V-1 and it becomes necessary to develop novel semiconductors with larger piezoelectric constant. In this work, it is shown that strong piezoelectricity exists in ε-Ga2 O3 . High-quality phase-pure ε-Ga2 O3 thin films with a relatively low residual stress are prepared. A switching spectroscopy piezoelectric force microscope (SS-PFM) measurement is carried out and the piezoelectric constant d33 of ε-Ga2 O3 is determined to be ≈10.8-11.2 pm V-1 , which is twice as large as that of AlN. For the first time, surface acoustic wave (SAW) resonators are demonstrated on the ε-Ga2 O3 thin films and different vibration modes resonating in the GHz range are observed. The results suggest that ε-Ga2 O3 is a great material candidate for application in piezoelectric devices, thanks to its wide bandgap, strong piezoelectric property, small acoustic impedance, and low residual stress.

2.
J Fungi (Basel) ; 8(8)2022 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-36012842

RESUMO

The nature of saprophytic and mycoparasitic hyphal growth of Trichoderma spp. has been studied extensively, yet its initiation via conidial germination in this genus is less well understood. Using near-synchronous germinating cultures of Trichoderma asperelloides, we followed the morphological progression from dormant conidia to initial polar growth to germling formation and to evidence for first branching. We found that the stage-specific transcriptional profile of T. asperelloides is one of the most dynamic described to date: transcript abundance of over 5000 genes-comprising approximately half of the annotated genome-was unremittingly reduced in the transition from dormancy to polar growth. Conversely, after the onset of germination, the transcript abundance of approximately a quarter of the genome was unremittingly elevated during the transition from elongation to initial branching. These changes are a testimony to the substantial developmental events that accompany germination. Bayesian network analysis identified several chitinase- and glucanase-encoding genes as active transcriptional hubs during germination. Furthermore, the expression of specific members of the chitin synthase and glucan elongase families was significantly increased during germination in the presence of Rhizoctonia solani-a known host of the mycoparasite-indicating that host recognition can occur during the early stages of mycoparasite development.

3.
Molecules ; 27(14)2022 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-35889211

RESUMO

The extraction of active constituents from natural sources in a green and efficient manner is considered an important field in the pharmaceutical industry. In recent years, deep eutectic solvents (DESs), a new type of green solvent, have attracted increasing attention. Therefore, we aimed to establish a green and high-efficiency extraction method for ginsenosides based on DESs. This study takes Panax ginseng as a model sample. Eighteen different DESs were produced to extract polar ginsenosides. Ultrasound-assisted extraction (UAE) was applied for simplicity and efficiency. A binary DES synthesized using choline chloride and urea at a proportion of 1:2 prepared by a heating stirring method is proven to be more effective than other solvents, such as the widely used 70% ethanol for the extraction of ginsenosides. Three variables that might affect the extraction, including the DES content in the extraction solvent, liquid/solid ratio, and ultrasound extraction time, were evaluated for optimization. The optimum extraction conditions for ginsenosides were determined as follows: DES water content of 20 wt%, liquid/solid ratio of 15 mL g-1, and an ultrasonic extraction time of 15 min. The extraction yield for the optimized method is found to be 31% higher than that for 70% ethanol, which achieves efficient extraction. This study shows that DESs are available to extract ginsenosides for use in traditional Chinese medicine. The discovery also contributes to further research into the green extraction of ginsenosides.


Assuntos
Ginsenosídeos , Panax , Solventes Eutéticos Profundos , Etanol , Solventes
4.
mBio ; 13(3): e0110022, 2022 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-35638737

RESUMO

Gene expression divergence through evolutionary processes is thought to be important for achieving programmed development in multicellular organisms. To test this premise in filamentous fungi, we investigated transcriptional profiles of 3,942 single-copy orthologous genes (SCOGs) in five related sordariomycete species that have morphologically diverged in the formation of their flask-shaped perithecia. We compared expression of the SCOGs to inferred gene expression levels of the most recent common ancestor of the five species, ranking genes from their largest increases to smallest increases in expression during perithecial development in each of the five species. We found that a large proportion of the genes that exhibited evolved increases in gene expression were important for normal perithecial development in Fusarium graminearum. Many of these genes were previously uncharacterized, encoding hypothetical proteins without any known functional protein domains. Interestingly, the developmental stages during which aberrant knockout phenotypes appeared largely coincided with the elevated expression of the deleted genes. In addition, we identified novel genes that affected normal perithecial development in Magnaporthe oryzae and Neurospora crassa, which were functionally and transcriptionally diverged from the orthologous counterparts in F. graminearum. Furthermore, comparative analysis of developmental transcriptomes and phylostratigraphic analysis suggested that genes encoding hypothetical proteins are generally young and transcriptionally divergent between related species. This study provides tangible evidence of shifts in gene expression that led to acquisition of novel function of orthologous genes in each lineage and demonstrates that several genes with hypothetical function are crucial for shaping multicellular fruiting bodies. IMPORTANCE The fungal class Sordariomycetes includes numerous important plant and animal pathogens. It also provides model systems for studying fungal fruiting body development, as its members develop fruiting bodies with a few well-characterized tissue types on common growth media and have rich genomic resources that enable comparative and functional analyses. To understand transcriptional divergence of key developmental genes between five related sordariomycete fungi, we performed targeted knockouts of genes inferred to have evolved significant upward shifts in expression. We found that many previously uncharacterized genes play indispensable roles at different stages of fruiting body development, which have undergone transcriptional activation in specific lineages. These novel genes are predicted to be phylogenetically young and tend to be involved in lineage- or species-specific function. Transcriptional activation of genes with unknown function seems to be more frequent than ever thought, which may be crucial for rapid adaption to changing environments for successful sexual reproduction.


Assuntos
Regulação Fúngica da Expressão Gênica , Neurospora crassa , Carpóforos/genética , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Neurospora crassa/genética , Desenvolvimento Sexual , Transcriptoma
5.
Zhongguo Zhong Yao Za Zhi ; 47(23): 6409-6416, 2022 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-36604886

RESUMO

Ginsenosides are the main active ingredients in ginseng. Studies have shown that ginsenosides have anti-virus, anti-tumor, anti-aging, nootropic, cardiovascular diseases-protecting, and other pharmacological activities. Thus, the development and utilization of ginsenosides have persistently attracted much attention. At present, the extraction of ginsenosides is mainly based on organic solvents, and there are relatively few studies on their green extraction. In this study, different deep eutectic solvents(DESs) were synthesized by heating and stirring method, combined with an emerging technology, mechanochemically-assisted extraction(MCAE), to extract ginsenosides in a green way. Six parameters that might affect the extraction effect were optimized to determine the optimal conditions, and the method validation was conducted. The new established method was compared with a commonly used extraction method(ultrasound-assisted extraction using 70% ethanol) to evaluate its extraction efficiency. The results revealed that the optimal extraction conditions of DES-MCAE were that the volume ratio of DES3(choline chloride∶urea 1∶2) and water in the extraction solvent was 6∶4, and the liquid ratio and the linear vibration speed were 0.05 g·mL~(-1) and 4.0 m·s~(-1); the extraction was performed twice, 40 s each. With only 80 s extraction, the extraction rate of this method was 36.22% higher than that of ultrasoun-dassisted extraction using 70% ethanol. In this study, a DESs-based pretreatment method for ginsenosides was established and its rapid, green and efficient extraction was realized, which provided new ideas and methods for further research on green extraction of other active ingredients from Chinese medicine.


Assuntos
Ginsenosídeos , Solventes Eutéticos Profundos , Solventes , Água , Etanol
6.
J Pharm Biomed Anal ; 206: 114353, 2021 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-34562802

RESUMO

Traditional Chinese medicine injections (TCMIs) are a new pharmaceutical form in the modernization of traditional Chinese medicines (TCMs). Its efficacy is rapid, the curative effect is improved, and is widely used in critical and acute diseases, complicated and severe diseases, and other treatment. However, with the broad applications of TCMIs, clinical adverse reactions frequently occur, and safety problems become more prominent. Therefore, the quality control of TCMIs is essential. Chemical analysis methods and biological analysis methods are widely used in the quality control of TCMIs. This article describes the current status of TCMIs, the analytical techniques, and methods currently used, and the quality control of TCMIs. A summary of the advantages and disadvantages of the current analysis methods is presented. An overview of the quality control of TCMIs is introduced. In addition, emerging techniques of the quality control of TCMIs are introduced.


Assuntos
Medicamentos de Ervas Chinesas , Medicina Tradicional Chinesa , Injeções , Controle de Qualidade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...