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1.
Biotechnol Biofuels Bioprod ; 16(1): 59, 2023 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-37016453

RESUMO

BACKGROUND: Keratin, the main component of chicken feather, is the third most abundant material after cellulose and chitin. Keratin can be converted into high-value compounds and is considered a potential high-quality protein supplement; However, its recalcitrance makes its breakdown a challenge, and the mechanisms of action of keratinolytic proteases-mediated keratinous substrates degradation are not yet fully elucidated. Bacillus sp. CN2, having many protease-coding genes, is a dominant species in keratin-rich materials environments. To explore the degradation patterns of feather keratin, in this study, we investigated the characteristics of feather degradation by strain CN2 based on the functional-degradomics technology. RESULTS: Bacillus sp. CN2 showed strong feather keratin degradation activities, which could degrade native feathers efficiently resulting in 86.70% weight loss in 24 h, along with the production of 195.05 ± 6.65 U/mL keratinases at 48 h, and the release of 0.40 mg/mL soluble proteins at 60 h. The extracellular protease consortium had wide substrate specificity and exhibited excellent biodegradability toward soluble and insoluble proteins. Importantly, analysis of the extracellular proteome revealed the presence of a highly-efficient keratin degradation system. Firstly, T3 γ-glutamyltransferase provides a reductive force to break the dense disulfide bond structure of keratin. Then S8B serine endopeptidases first hydrolyze keratin to expose more cleavage sites. Finally, keratin is degraded into small peptides under the synergistic action of proteases such as M4, S8C, and S8A. Consistent with this, high-performance liquid chromatography (HPLC) and amino acid analysis showed that the feather keratin hydrolysate contained a large number of soluble peptides and essential amino acids. CONCLUSIONS: The specific expression of γ-glutamyltransferase and co-secretion of endopeptidase and exopeptidase by the Bacillus sp. CN2 play an important role in feather keratin degradation. This insight increases our understanding of the keratinous substrate degradation and may inspire the design of the optimal enzyme cocktails for more efficient exploration of protein resources in industrial applications.

2.
Int J Nurs Sci ; 10(1): 89-96, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36860717

RESUMO

Objectives: This study aimed to determine patients' perceived benefits of a WeChat applet for self-management of patients with neurogenic bladder (NGB) and identify the key factors hindering their adoption. Methods: In the qualitative study, 19 NGB patients were invited for semi-structured interviews. They were hospitalized in the rehabilitation departments of two tertiary hospitals in Shenzhen and tried out the self-management applet for two weeks. Data were analyzed using the content analysis method. Results: The results indicated that the WeChat applet of self-management was helpful and embraced by the NGB patients. Three perceived benefits were identified 1) being accessible, flexible, and intuitive to users, 2) driving bladder self-management, and 3) directing the way for care partners and family members. Challenges hindering the adoption of the applet included 1) negative attitudes of patients towards bladder self-management and patient characteristics, 2) concerns about the risks of mHealth, and 3) the necessity of applet upgrading. Conclusion: This study showed feasibility of the WeChat applet for self-management among NGB patients to meet their needs for access to information during hospitalization and after discharge. The study also identified facilitators and barriers to patient use, providing valuable information for healthcare providers to implement mHealth interventions to promote self-management among NGB patients.

3.
Adv Sci (Weinh) ; 9(35): e2203863, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36285684

RESUMO

In condensed matter physics, oxide materials show various intriguing physical properties. Therefore, many efforts are made in this field to develop functional oxides. Due to the excellent potential for tin-based perovskite oxides, an expansion of new related functional compounds is crucial. This work uses a heteroepitaxial approach supported by theoretical calculation to stabilize PbSnO3 thin films with different orientations. The analyses of X-ray diffraction and transmission electron microscopy unveil the structural information. A typical antiferroelectric feature with double hysteresis and butterfly loops is observed through electrical characterizations consistent with the theoretical prediction. The phase transition is monitored, and the transition temperatures are determined based on temperature-dependent structural and electrical characterizations. Furthermore, the microscopic antiferroelectric order is noticed under atomic resolution images via scanning transmission electron microscopy. This work offers a breakthrough in synthesizing epitaxial PbSnO3 thin films and comprehensively understanding its anisotropic antiferroelectric behavior.

4.
ACS Appl Mater Interfaces ; 14(19): 22278-22286, 2022 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-35523210

RESUMO

Relaxor ferroelectric-based energy storage systems are promising candidates for advanced applications as a result of their fast speed and high energy storage density. In the research field of ferroelectrics and relaxor ferroelectrics, the concept of solid solution is widely adopted to modify the overall properties and acquire superior performance. However, the combination between antiferroelectric and paraelectric materials was less studied and discussed. In this study, paraelectric barium hafnate (BaHfO3) and antiferroelectric lead hafnate (PbHfO3) are selected to demonstrate such a combination. A paraelectric to relaxor ferroelectric, to ferroelectric, and to antiferroelectric transition is observed by varying the composition x in the (Ba1-xPbx)HfO3 solid solution from 0 to 100%. It is noteworthy that ferroelectric phases can be realized without primal ferroelectric material. This study creates an original solid solution system with a rich spectrum of competing phases and demonstrates an approach to design relaxor ferroelectrics for energy storage applications and beyond.

5.
Nat Commun ; 13(1): 1187, 2022 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-35246554

RESUMO

Amorphous materials have attracted increasing attention in diverse fields due to their unique properties, yet their controllable fabrications still remain great challenges. Here, we demonstrate a top-down strategy for the fabrications of amorphous oxides through the amorphization of hydroxides. The versatility of this strategy has been validated by the amorphizations of unitary, binary and ternary hydroxides. Detailed characterizations indicate that the amorphization process is realized by the variation of coordination environment during thermal treatment, where the M-OH octahedral structure in hydroxides evolves to M-O tetrahedral structure in amorphous oxides with the disappearance of the M-M coordination. The optimal amorphous oxide (FeCoSn(OH)6-300) exhibits superior oxygen evolution reaction (OER) activity in alkaline media, where the turnover frequency (TOF) value is 39.4 times higher than that of FeCoSn(OH)6. Moreover, the enhanced OER performance and the amorphization process are investigated with density functional theory (DFT) and molecule dynamics (MD) simulations. The reported top-down fabrication strategy for fabricating amorphous oxides, may further promote fundamental research into and practical applications of amorphous materials for catalysis.

6.
Se Pu ; 40(3): 253-265, 2022 Mar 08.
Artigo em Chinês | MEDLINE | ID: mdl-35243835

RESUMO

An accurate mass database and a method based on ultra high performance liquid chromatography-electrostatic field orbitrap high resolution mass spectrometry (UHPLC-Orbitrap HRMS) were developed. These were applied in the screening and identification of illegally added medicines in herbal tea. Based on investigations, 167 medicines were selected to build an accurate MS database; these medicines included antipyretic analgesics, glucocorticoids, antibiotics, and antihistamines, among other categories. The database was established using Orbitrap HRMS and TraceFinder software. The database carried information on all selected compounds, including the molecular formula, accurate mass of precursor ions and fragment ions, retention time, and mass spectra. The samples were ultrasonically extracted with a 50% (v/v) methanol aqueous solution. The extracted solutions were separated using a Waters XBrigde BEH C18 column (100 mm×2.1 mm, 2.5 µm). As the mobile phases, 0.1% (v/v) formic acid aqueous solution and acetonitrile containing 0.1% (v/v) formic acid were used, with gradient elution. The sample solutions were analyzed by Orbitrap HRMS in the full-scan MS and data-dependent MS/MS acquisition modes (Full MS/dd-MS2). Positive and negative polarity data were simultaneously acquired. Some parameters were optimized to increase the peak intensity and sensitivity of all compounds. The resolutions in the full-MS scan and dd-MS2 scan were set to 70000 and 17500, respectively. In the full-MS mode, scanning was performed in the range of m/z 100 to 1000. In the MS/MS mode, the normalized collision energy (NEC) was set to 20%, 40%, and 60% for each compound. The inclusion list was not used during the measurement, and the dynamic exclusion time was set to 10.0 s. The loop count was set to 5. After acquiring the sample data with these conditions using Orbitrap MS, they were imported into TraceFinder software, through which the sample information was extracted and automatically matched with the information on compounds in the MS database. Screening and identification were conducted by comparing the retention times as well as the exact masses of precursor ions and fragment ions that were experimentally measured. If the errors between the experimentally and theoretically obtained masses of the precursor ions were below 5×10-6 and the deviations in retention times were less than 20 s, then suspicious positive compounds might be identified. Furthermore, if such compounds possess more than one similar fragment ion with a mass tolerance below 5×10-6, and exhibit similar ion distributions in the MS/MS profiles (compared to those in the database), they could be confirmed to be the same. The validation result showed that all compounds had good linear relationships, with correlation coefficients (r) greater than 0.99. Because pefloxacin, norfloxacin, desloratadine, astemizole and clindamycin had background interference, the method was not suitable for their quantification. Following experiments using three spiked concentrations, the recoveries of the rest 162 compounds were found to be in the range of 66.4%-118.1%, and the relative standard deviations (RSDs, n=6), in the range of 0.1%-16.1%. When the limit of detection (LOD) was 0.2 mg/kg, 83 compounds were detected, while when the LOD was 1.0 mg/kg, 167 compounds were detected. All compounds were matched successfully to the standard added sample with the MS database in TraceFinder software. To lower the likelihood of false positive and false negative results, a quality control method was recommended. The method was applied to analyze 245 herbal tea samples, among which 12 positive samples were detected. Thirteen positive compounds were found, including acetaminophen, diclofenac sodium, chlorpheniramine, brompheniramine, dexamethasone, dexamethasone 21-acetate, prednisone, prednisone 21-acetate, metronidazole, erythromycin, ciprofloxacin, amantadine, and dextromethorphan. In particular, amantadine, dextromethorphan, brompheniramine, and ciprofloxacin were newly detected, compared to standard methods. The developed method is rapid and accurate, and will be useful in the high-throughput screening of illegally added medicines in herbal tea.


Assuntos
Espectrometria de Massas em Tandem , Chás de Ervas , Cromatografia Líquida de Alta Pressão , Limite de Detecção , Eletricidade Estática
7.
ACS Appl Mater Interfaces ; 13(18): 21186-21193, 2021 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-33905241

RESUMO

Flexible electronics has recently captured extensive attention due to its intriguing functionalities and great potential for influencing our daily life. In addition, with the increasing demand for green energy, photoelectrochemical (PEC) water splitting is a clean process that directly converts solar energy to chemical energy in the form of hydrogen. Thus the development of flexible green energy electronics represents a new domain in the research field of energy harvesting. In this work, we demonstrate the BiVO4 (BVO)/WO3/ITO/muscovite heterostructure photoelectrode for water splitting with flexible characteristics. The performance of BVO was modified by specific crystal facets, and the BVO/WO3 bilayer exhibited superior performance of 33% enhanced PEC activity at 1 V vs Ag/AgCl compared with pure BVO due to the proper staggered band alignment. Moreover, excellent mechanical stability was verified by a series of bending modes. This study demonstrates a pathway to a flexible photoelectrode for developing innovative devices for solar fuel generation.

8.
ACS Appl Mater Interfaces ; 13(16): 18991-18998, 2021 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-33851818

RESUMO

Single crystal wafers, such as silicon, are the fundamental carriers of advanced electronic devices. However, these wafers exhibit rigidity without mechanical flexibility, limiting their applications in flexible electronics. Here, we propose a new approach to fabricate 1.5 in. flexible functional zinc oxide (ZnO) single crystal wafers with high electron mobility (>100 cm2 V-1 s-1) and optical transparency (>80%) by a combination of thin-film deposition, a chemical solution method, and surficial treatment. The uniformity of the flexible single crystal wafers is examined by an advanced scanning X-ray diffraction technique and photoluminescence spectroscopy. The transport properties of ZnO flexible single crystal wafers retain their pristine states under various bending conditions, including cyclability and endurability. This approach demonstrates a breakthrough in the fabrication of the flexible single crystal wafers for future flexible optoelectronic applications.

9.
Appl Microbiol Biotechnol ; 105(2): 707-723, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33386896

RESUMO

A novel protease-producing Bacillus sp. CN2 isolated from chicken manure composts exhibited a relatively high proteolytic specific activity. The strain CN2 degradome consisted of at least 149 proteases and homolog candidates, which were distributed into 4 aspartic, 30 cysteine, 55 metallo, 56 serine, and 4 threonine proteases. Extracellular proteolytic activity was almost completely inhibited by PMSF (phenylmethylsulfonyl fluoride) rather than o-P, E-64, or pepstatin A, suggesting that strain CN2 primarily secreted serine protease. More importantly, analysis of the extracellular proteome of strain CN2 revealed the presence of a highly efficient protein degradation system. Three serine proteases of the S8 family with different active site architectures firstly fragmented protein substrates which were then degraded to smaller peptides by a M4 metalloendopeptidase that prefers to degrade hydrophobic peptides and by a S13 carboxypeptidase. Those enzymes acted synergistically to degrade intact substrate proteins outside the cell. Furthermore, highly expressed sequence-specific intracellular aminopeptidases from multiple families (M20, M29, and M42) accurately degraded peptides into oligopeptides or amino acids, thus realizing the rapid acquisition and utilization of nitrogen sources. In this paper, a systematic study of the functional-degradome provided a new perspective for understanding the complexity of the protease hydrolysis system of Bacillus, and laid a solid foundation for further studying the precise degradation of proteins with the cooperative action of different family proteases. KEY POINTS: • Bacillus sp. CN2 has relatively high proteolytic specific activity. • Bacillus sp. CN2 harbors a highly efficient protein degradation system. • The site-specific endopeptidases were secreted extracellular, while the sequence-specific aminopeptidases played a role in the cell.


Assuntos
Bacillus , Bacillus/metabolismo , Hidrólise , Peptídeo Hidrolases/metabolismo , Proteólise , Serina Endopeptidases/metabolismo
10.
Sci Rep ; 10(1): 16098, 2020 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-32999335

RESUMO

Flexible and self-powered deep ultraviolet (UV) photodetectors are pivotal for next-generation electronic skins to enrich human life quality. The fabrication of epitaxial ß-Ga2O3 thin films is challenging on flexible substrates due to high-temperature growth requirements. Herein, ß-Ga2O3 ([Formula: see text] 0 1) films are hetero-epitaxially grown on ultra-thin and environment-friendly muscovite mica which is the first time ß-Ga2O3 epitaxy growth on any flexible substrate. Integration of Gallium oxide with muscovite enables high-temperature processing as well as excellent flexibility compared to polymer substrates. Additionally, the metal-semiconductor-metal (MSM) photodetector on ß-Ga2O3 layer shows an ultra-low dark current of 800 fA at zero bias. The photovoltaic peak responsivity of 11.6 µA/W is obtained corresponding to very weak illumination of 75 µW/cm2 of 265 nm wavelength. Thermally stimulated current (TSC) measurements are employed to investigate the optically active trap states. Among these traps, trap with an activation energy of 166 meV dominates the persistence photocurrent in the devices. Finally, photovoltaic detectors have shown excellent photocurrent stability under bending induced stress up to 0.32%. Hence, this novel heteroepitaxy opens the new way for flexible deep UV photodetectors.

11.
ACS Appl Mater Interfaces ; 12(41): 46874-46882, 2020 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-32956583

RESUMO

Epitaxial CoFe2O4(CFO)/CoO bilayers were fabricated by pulsed laser deposition on flexible muscovite mica substrate. Samples with different CFO thicknesses were employed to study the phenomenon of exchange bias involving strongly anisotropic ferromagnet. Magnetic measurements exhibited great enhancement in the features of exchange bias. Raman and X-ray absorption spectroscopies indicated that a new phase emerged within the CFO layer because of the cation charge redistribution in CFO layer under bending, which in turn gave rise to anomalous hysteresis loops exhibited in the bent bilayers. These results provide a fundamental understanding about the mechanisms of exchange bias prevailing in these bilayers and call attention to the implementation of spintronic devices using flexible heterostructures such as the present CFO/CoO bilayers.

12.
Small ; 16(24): e2000020, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32419389

RESUMO

Transparent flexible energy storage devices are considered as important chains in the next-generation, which are able to store and supply energy for electronic devices. Here, aluminum-doped zinc oxide (AZO) nanorods (NRs) and nickel oxide (NiO)-coated AZO NRs on muscovites are fabricated by a radio frequency (RF) magnetron sputtering deposition method. Interestingly, AZO NRs and AZO/NiO NRs are excellent electrodes for energy storage application with high optical transparency, high conductivity, large surface area, stability under compressive and tensile strain down to a bending radius of 5 mm with 1000 bending cycles. The obtained symmetric solid-state supercapacitors based on these electrodes exhibit good performance with a large areal specific capacitance of 3.4 mF cm-2 , long cycle life 1000 times, robust mechanical properties, and high chemical stability. Furthermore, an AZO/NiO//Zn battery based on these electrodes is demonstrated, yielding a discharge capacity of 195 mAh g-1 at a current rate of 8 A g-1 and a discharge capacity of over 1000 cycles with coulombic efficiency to 92%. These results deliver a concept of opening a new opportunity for future applications in transparent flexible energy storage.

13.
ACS Appl Mater Interfaces ; 12(19): 21818-21826, 2020 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-32297504

RESUMO

The piezoresistive effect has shown a remarkable potential for mechanical sensor applications and been sought for its excellent performance. A great attention was paid to the giant piezoresistive effect and sensitivity delivered by silicon-based nanostructures. However, low thermal stability and complicated fabrication process hinder their practical applications. To overcome these issues and enhance the functionalities, we envision the substantial piezopotential in a zinc oxide (ZnO)/muscovite (mica) heteroepitaxy system based on theoretical consideration and realize it in practice. High piezoresistive effect with giant change of resistivity (-80 to 240%) and large gauge factor (>1000) are demonstrated through mechanical bending. The detailed features of heteroepitaxy, electrical transport, and strain are probed to understand the mechanism of such a giant resistivity change. In addition, a bending model is established to reveal the distribution of strain. Finally, we demonstrate a flex sensor featuring high sensitivity, optical transparency, and two-segment sensing with a great potential toward practical applications. Such an oxide heteroepitaxy exhibits excellent piezoresistive properties and mechanical flexibility. In the near future, the importance of flex sensors will emerge because of the precise control in the automation industries, and our results lead to a new design in the field of flex sensors.

14.
Nanoscale ; 12(5): 3284-3291, 2020 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-31971196

RESUMO

The employment of flexible muscovite substrates has given us the feasibility of applying strain to heterostructures dynamically by mechanical bending. In this study, this novel approach is utilized to investigate strain effects on the exchange coupling in ferromagnetic Co and anti-ferromagnetic CoO (Co/CoO) bilayers. Two different Co/CoO bilayer heterostructures were grown on muscovite substrates by oxide molecular beam epitaxy, with the CoO layer being purely (111)- and (100)-oriented. The strain-dependent exchange coupling effect can only be observed on Co/CoO(100)/mica but not on Co/CoO(111)/mica. The origin of this phenomenon is attributed to the anisotropic spin re-orientation induced by mechanical bending. The strain-dependent magnetic anisotropy of the bilayers determined by anisotropic magnetoresistance measurements confirms this conjecture. This study elucidates the fundamental understanding of how magnetic exchange coupling can be tuned by externally applied strain via mechanical bending and, hence, provides a novel approach for implementing flexible spintronic devices.

15.
ACS Appl Mater Interfaces ; 11(38): 35162-35168, 2019 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-31476857

RESUMO

Materials with high spin-polarization play an important role in the development of spintronics. Co-based Heusler compounds are a promising candidate for practical applications because of their high Curie temperature and tunable half-metallicity. However, it is a challenge to integrate Heusler compounds into thin film heterostructures because of the lack of control on crystallinity and chemical disorder, critical factors of novel behaviors. Here, muscovite is introduced as a growth substrate to fabricate epitaxial Co2MnGa films with mechanical flexibility. The feature of heteroepitaxy is evidenced by the results of X-ray diffraction and transmission electron microscopy. Moreover, high chemical ordering with superior properties is delivered according to the observation of large Hall conductivity (680 Ω-1 cm-1) and highly saturated magnetic moment (∼3.93 µB/f.u.), matching well with bulk crystals. Furthermore, the excellence of magnetic and electrical properties is retained under the various mechanical bending conditions. Such a result suggests that the development of Co2MnGa/muscovite heteroepitaxy provides not only a pathway to the thin film heterostructure based on high-quality Heusler compounds but also a new aspect of spintronic applications on flexible substrates.

16.
ACS Appl Mater Interfaces ; 11(29): 25882-25890, 2019 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-31257841

RESUMO

With the rise of Internet of Things, the presence of flexible devices has attracted significant attention owing to design flexibility. A ferroelectric field-effect transistor (FeFET), showing the advantages of high speed, nondestructive readout, and low-power consumption, plays a key role in next-generation technology. However, the performance of these devices is restricted since conventional flexible substrates show poor thermal stability to integrate traditional ferroelectric materials, limiting the compatibility of wearable devices. In this study, we adopt flexible muscovite mica as a substrate due to its good thermal properties and epitaxial integration ability. A flexible FeFET composed of oxide heteroepitaxy on muscovite is realized by combining an aluminum-doped zinc oxide film as the semiconductor channel layer and a Pb(Zr0.7Ti0.3)O3 film as the ferroelectric gate dielectric. The excellent characteristics of the transistor together with superior thermal stability and mechanical flexibility are demonstrated through various mechanical bending and temperature measurements. The on/off current ratio of the FeFET is higher than 103, which based on the field effect in the transfer curve. The smallest bending radius that can be achieved is 5 mm with a cyclability of 300 times and a retention of 100 h. This study opens an avenue to use oxide heteroepitaxy to construct a FeFET for next-generation flexible electronic systems.

17.
Se Pu ; 37(12): 1331-1336, 2019 Dec 08.
Artigo em Chinês | MEDLINE | ID: mdl-34213135

RESUMO

A method based on high-performance liquid chromatography-tandem mass spectrometry was developed for the determination of sodium picosulfate in enzyme products. Sodium picosulfate is a new slimming aid that is illegally added to food products. The existing analytical methods are not suitable for application to jellies and gel candies, thus triggering the need for developing a new method. The samples were extracted with water and passed through a polyamide cartridge. The extracts were separated on a Thermo Accucore RP-MS column (100 mm×2.1 mm, 2.6 µm) using acetonitrile-10 mmol/L ammonium acetate solution (15:85, v/v) as the mobile phase. The flow rate of the mobile phase was 0.3 mL/min, and the column temperature was 35 ℃. Detection was carried out in the multiple reaction monitoring (MRM) mode. Quantification analysis was performed by the external standard method. The results showed that sodium picosulfate had a good linear relationship in the range of 5-500 µg/L, and the correlation coefficient (r) was 0.9999. The limit of detection (LOD) was 0.05 mg/kg. The average recoveries of sodium picosulfate in different matrices were in the range of 89.2%-111.8%, with the relative standard deviations (RSDs) of 2.5%-10.4%. The method was applied to the analysis of 152 samples, and 58 positive samples were detected. The positive rate was 38.2%. The developed method is accurate and sensitive, and it is suitable for detecting sodium picosulfate in enzyme products.

18.
Se Pu ; 36(12): 1284-1289, 2018 Dec 08.
Artigo em Chinês | MEDLINE | ID: mdl-30574707

RESUMO

A method for determining chloramphenicol (CAP) in both propolis and propolis-derived dietary supplements was developed by utilizing high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The flavones in the samples were removed with a lead acetate solution and ammonia, and the fat-soluble interferences, such as beewax and vegetable oils, were removed with n-hexane after the sample dissolved in ethanol. Tert-butyl methyl ether was used as the back-extraction solvent to reduce co-extracting compounds, such as polyethylene glycol 400 (PEG 400) and glycerol, which are common adjuvants of dietary supplements, and some polar interferences. CAP was detected by HPLC-MS/MS and quantified by the internal standard method. The calibration curve showed a good linearity in the range of 0.20-50.0 µg/L. The limits of detection and the limits of quantification were 0.03 and 0.1 µg/kg, respectively. The recoveries in four different matrices at three spiked levels were in the 86.0%-114.4% range with the relative standard deviations from 0.3% to 4.9%. With the advantages of excellent universality, ease of operation, high sensitivity, and strong anti-interference capability, the proposed method was suitable for the determination of CAP in both propolis and propolis-derived dietary supplements.


Assuntos
Cloranfenicol/análise , Cromatografia Líquida de Alta Pressão , Suplementos Nutricionais/análise , Própole/análise , Espectrometria de Massas em Tandem
19.
Se Pu ; 36(8): 758-765, 2018 Aug 08.
Artigo em Chinês | MEDLINE | ID: mdl-30251499

RESUMO

A high performance liquid chromatographic method for the determination of 28 exogenous medicines and endogenous components in the herbal drink was developed. The samples were extracted ultrasonically with methanol-water (70:30, v/v), and the extracts were separated in a Thermo Accucore C18 column (100 mm×4.6 mm, 2.6 µm) with methanol-acetonitrile-20 mmol/L ammonium acetate solution (pH 4.2) as the mobile phases by gradient elution. The flow rate was 1.2 mL/min and the column temperature was 35℃. The detection wavelengths were 254 nm and 220 nm. Quantification analysis was performed by the external standard method. The result showed the compounds had a good linear relationship in the range of 1-100 mg/L, and the correlation coefficients (r) were not less than 0.999. The limits of detection (LODs) of the 28 compounds were 1-10 mg/kg in the liquid sample and 20-200 mg/kg in the solid sample. The average recoveries of the 28 compounds in the liquid and solid samples were in the ranges of 88.8%-118.6% and 92.7%-112.3% with the relative standard deviations (RSDs) of 0.1%-6.7% and 0.1%-6.4%, respectively. The method was applied to analyze 456 herbal drink samples, and 55 positive samples were found. The positive rate was 12.1%. The developed method was simple and reliable, and it was suitable for the determination of 28 components in the herbal drink.


Assuntos
Bebidas/análise , Contaminação de Alimentos/análise , Preparações Farmacêuticas/análise , Cromatografia Líquida de Alta Pressão , Limite de Detecção
20.
ACS Appl Mater Interfaces ; 10(36): 30574-30580, 2018 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-30118205

RESUMO

In the era of Internet of Things, the demand for flexible and transparent electronic devices has shifted to the forefront of materials science research. However, the radiation damage to key performance of transparent devices under radiative environment remains as a critical issue. Here, we present a promising technology for nonvolatile transparent electronic devices based on flexible oxide heteroepitaxy. A direct fabrication of epitaxial lead lanthanum zirconate titanate on transparent flexible mica substrate with indium tin oxide electrodes is presented. The transparent flexible ferroelectric heterostructures not only retain their superior performance, thermal stability, reliability, and mechanical durability, but also exhibit remarkably robust properties against to a strong radiation exposure. Our study demonstrates an extraordinary concept to realize transparent flexible nonvolatile electronic devices for the design and development of next-generation smart devices with potential application in electronics, automotive, aerospace, and nuclear systems.

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