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1.
Food Chem ; 371: 131204, 2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-34598114

RESUMO

In this study, a high-performance flexible reduced graphene oxide (rGO) paper electrode composed of silver nanoparticles (Ag NPs) for the detection of Sudan I was fabricated. Ag NPs were doped with rGO nanoheets by self-assemble and assembled into a paper electrode with layer-by-layer structure via vacuum filtration. Thanks to the highly efficient electrocatalysis of Ag NPs towards reduction of azo bond, the as-prepared hybrid paper can be used alone as a flexible sensor for the detection of Sudan I in chili powder, with the high sensitivity (22.93 µA µmol/L) and the low detection limit (41.3 nmol/L). The sensor also expressed good selectivity, repeatability, reproducibility, stability and recovery between 96.1% and 101.8% (RSD < 6%). With the advantages of low-cost and scalable production capacity, such Ag NPs/rGO functional papers can be used as flexible disposable sensors for electrochemical detection of Sudan I.


Assuntos
Grafite , Nanopartículas Metálicas , Técnicas Eletroquímicas , Eletrodos , Naftóis , Reprodutibilidade dos Testes , Prata
2.
Nanomaterials (Basel) ; 11(11)2021 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-34835617

RESUMO

Carbon-based nanomaterials have become the subject of intensive interest because their intriguing physical and chemical properties are different from those of their bulk counterparts, leading to novel applications in smart sensors. Mycotoxins are secondary metabolites with different structures and toxic effects produced by fungi. Mycotoxins have low molecular weights and highly diverse molecular structures, which can induce a spectrum of biological effects in humans and animals even at low concentrations. A tremendous amount of biosensor platforms based on various carbon nanocomposites have been developed for the determination of mycotoxins. Therefore, the contents of this review are based on a balanced combination of our own studies and selected research studies performed by academic groups worldwide. We first address the vital preparation methods of biorecognition unit (antibodies, aptamers, molecularly imprinted polymers)-functionalized carbon-based nanomaterials for sensing mycotoxins. Then, we summarize various types of smart sensors for the detection of mycotoxins. We expect future research on smart sensors to show a significant impact on the detection of mycotoxins in food products.

3.
Sensors (Basel) ; 21(21)2021 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-34770482

RESUMO

This paper introduces a cognitive psychological experiment that was conducted to analyze how traditional film editing methods and the application of cognitive event segmentation theory perform in virtual reality (VR). Thirty volunteers were recruited and asked to watch a series of short VR videos designed in three dimensions: time, action (characters), and space. Electroencephalograms (EEG) were recorded simultaneously during their participation. Subjective results show that any of the editing methods used would lead to an increased load and reduced immersion. Furthermore, the cognition of event segmentation theory also plays an instructive role in VR editing, with differences mainly focusing on frontal, parietal, and central regions. On this basis, visual evoked potential (VEP) analysis was performed, and the standardized low-resolution brain electromagnetic tomography algorithm (sLORETA) traceability method was used to analyze the data. The results of the VEP analysis suggest that shearing usually elicits a late event-related potential component, while the sources of VEP are mainly the frontal and parietal lobes. The insights derived from this work can be used as guidance for VR content creation, allowing VR image editing to reveal greater richness and unique beauty.


Assuntos
Realidade Virtual , Cognição , Eletroencefalografia , Potenciais Evocados , Potenciais Evocados Visuais , Humanos
4.
Psych J ; 2021 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-34755495

RESUMO

Envy is a mixed negative emotion that is characterized by feelings of hostility, inferiority, resentment, and depression. It has been found that mindfulness is negatively associated with envy. This paper aimed to explore the interaction between mindfulness and envy by referring to the mindful emotion regulation model, and it also examines the mediation of emotional intelligence. Six hundred and seventy-six participants (182 men and 494 women) completed the Mindful Attention Awareness Scale, the Dispositional Envy Scale, and the Wong Law Emotional Intelligence Scale. Results suggest that mindfulness is significantly and negatively correlated with envy. Meanwhile, a multiple mediation analysis indicated that regulation of emotion and use of emotion partially mediate the impact of mindfulness on envy. The current study not only provides a theoretical basis for possible mechanisms underlying the inhibition of envy, but also provides valuable guidance for developing mindfulness-based intervention programs aiming at reducing the negative effects of envy.

5.
Chemosphere ; : 132662, 2021 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-34756948

RESUMO

In this work, Mn(CeZr)Ox was synthesized by using chelation-induced synergistic self-assembly strategy for the combustion of toluene. The physicochemical properties of the synthesized catalysts were characterized by XRD, ICP-MS, SEM, TEM, XPS and N2 sorption. The Mn(CeZr)Ox catalyst with T90 = 225 °C exhibited improved catalytic performance than the original MnOx catalyst (T90 = 260 °C) and had significant low-temperature activity. The relationship between catalyst activity and structure was analyzed. By substituting Ce and Zr elements into the hollow microspheres of MnO2, oxygen vacancies were produced. The main factors affecting the catalytic activity of the catalyst and the reason why it remained high catalytic activity after a long period of hydrothermal treatment were discussed. After hydrothermal aging, the original pore structure of Mn(CeZr)Ox catalyst collapsed and the specific surface area decreased, but the overall crystallinity of the catalyst increased and the content of oxygen species in the lattice increased. The distribution of Mn and oxygen species on the catalyst surface changed significantly after hydrothermal treatment. The appropriate ratio of Mn4+ to Mn3+ and the ratio of lattice oxygen to adsorbed oxygen species are beneficial to the redox reaction cycle.

6.
Cancer Lett ; 522: 225-237, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34582975

RESUMO

Glioblastoma (GBM) is one of the most devastating cancers and is characterized by rapid cell proliferation and aggressive invasiveness. Legumain (LGMN), a substrate-specific protease, is associated with poor progression of GBM. Circular RNAs (circRNAs) are aberrantly expressed in various cancers and play crucial roles in tumor progression; however, the functional roles of circRNAs originating from LGMN remain largely unknown in GBM. Herein, we found that hsa_circ_0033009 (circLGMN) was the most abundantly expressed circRNA derived from LGMN. CircLGMN was upregulated in high-grade glioma (HGG), and high expression of circLGMN was associated with poor prognosis in patients with glioma. CircLGMN overexpression promoted GBM cell proliferation and enhanced cell invasion. Mechanistically, circLGMN acts as a sponge for miR-127-3p, and prevents miR-127-3p-mediated degradation of LGMN mRNA, ultimately leading to increased LGMN protein expression. Treatment with miR-127-3p mimic suppressed proliferation and reduced invasion of GBM cells overexpressing circLGMN. Moreover, circLGMN overexpression promoted GBM malignancy in vivo, while miR-127-3p overexpression alleviated this effect. Taken together, circLGMN is a novel tumor-promoting circRNA that acts by sponging miR-127-3p, which ultimately leads to LGMN upregulation. Thus, targeting the circLGMN/miR-127-3p/LGMN axis might be a promising strategy for GBM treatment. More importantly, the discovery of the self-regulatory mechanism of LGMN expression by circLGMN, will facilitate further research on LGMN.

7.
Anal Methods ; 13(39): 4623-4633, 2021 10 14.
Artigo em Inglês | MEDLINE | ID: mdl-34542118

RESUMO

Household dust is a sink for multiple toxic chemicals with known or suspected potential health effects. However, most dust exposure studies focus on a few chemicals, which may limit overall understanding of human exposure characteristics because people spend most of their time indoors. This paper describes the development and evaluation of a multi-residue analysis of 20 organochlorine pesticides (OCPs), 15 polycyclic aromatic hydrocarbons (PAHs), 8 polybrominated diphenyl ether congeners (PBDEs), 3 hexabromocyclododecane (HBCDs), 8 synthetic musks (Musks), and 7 organophosphate esters (OPEs) in indoor dusts. After extraction with acetone/hexane (v/v, 1 : 1), all target compounds were fractionated with a Florisil solid-phase extraction (SPE) cartridge into two fractions: PAHs, PBDEs, HBCDs, OCPs and Musks, which were eluted with hexane/dichloromethane, and OPEs eluted with ethyl acetate. Further clean-up using acidified silica 44% cartridges was then performed to enable determination of PBDEs and HBCDs. Instrumental analysis of the target chemicals was performed using gas chromatography (GC) or liquid chromatography (LC) coupled with mass spectrometry (MS) or tandem mass spectrometry (MS/MS). A newly-optimized GC-MS/MS method was employed for the simultaneous determination of PAHs, OCPs, and Musks. The lower limit of quantification (LOQ) values of PAHs, OCPs, and Musks were 0.14-0.92 ng g-1, 0.06-0.38 ng g-1 and 0.07-0.40 ng g-1, respectively. PBDEs were quantified by GC-MS with electron capture negative ionization, and HBCDs and OPEs by LC-MS/MS with electrospray ionization (ESI) in negative and positive ion mode, respectively. Recovery experiments showed that the average recoveries and relative standard deviations were 99-113% and 1-14% for PBDEs, 89-105% and 1-6% for HBCDs, 71-120% and 3-17% for PAHs, 71-112% and 2-17% for OCPs, 77-120% and 2-13% for Musks, and 80-127% and 1-14% for OPEs. Validation experiments showed that the method achieved good accuracy. The developed method was used to analyze SRM 2585 and real indoor dust samples to demonstrate its suitability for routine analysis. The target contaminants were widely detected in SRM 2585 and indoor dust collected from Wuhan of Central China, with PAHs the major species, followed by OPEs, OCPs, and PBDEs.


Assuntos
Retardadores de Chama , Praguicidas , Compostos Policíclicos , Cromatografia Líquida , Poeira/análise , Retardadores de Chama/análise , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Organofosfatos , Praguicidas/análise , Espectrometria de Massas em Tandem
8.
Int J Nanomedicine ; 16: 6067-6094, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34511906

RESUMO

In recent years, Au-based nanomaterials are widely used in nanomedicine and biosensors due to their excellent physical and chemical properties. However, these applications require Au NPs to have excellent stability in different environments, such as extreme pH, high temperature, high concentration ions, and various biomatrix. To meet the requirement of multiple applications, many synthetic substances and natural products are used to prepare highly stable Au NPs. Because of this, we aim at offering an update comprehensive summary of preparation high stability Au NPs. In addition, we discuss its application in nanomedicine. The contents of this review are based on a balanced combination of our studies and selected research studies done by worldwide academic groups. First, we address some critical methods for preparing highly stable Au NPs using polymers, including heterocyclic substances, polyethylene glycols, amines, and thiol, then pay attention to natural product progress Au NPs. Then, we sum up the stability of various Au NPs in different stored times, ions solution, pH, temperature, and biomatrix. Finally, the application of Au NPs in nanomedicine, such as drug delivery, bioimaging, photothermal therapy (PTT), clinical diagnosis, nanozyme, and radiotherapy (RT), was addressed concentratedly.


Assuntos
Hipertermia Induzida , Nanopartículas Metálicas , Sistemas de Liberação de Medicamentos , Ouro , Nanomedicina , Polímeros
9.
PLoS One ; 16(9): e0256211, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34499667

RESUMO

Previous studies have suggested that virtual reality (VR) can elicit emotions in different visual modes using 2D or 3D headsets. However, the effects on emotional arousal by using these two visual modes have not been comprehensively investigated, and the underlying neural mechanisms are not yet clear. This paper presents a cognitive psychological experiment that was conducted to analyze how these two visual modes impact emotional arousal. Forty volunteers were recruited and were randomly assigned to two groups. They were asked to watch a series of positive, neutral and negative short VR videos in 2D and 3D. Multichannel electroencephalograms (EEG) and skin conductance responses (SCR) were recorded simultaneously during their participation. The results indicated that emotional stimulation was more intense in the 3D environment due to the improved perception of the environment; greater emotional arousal was generated; and higher beta (21-30 Hz) EEG power was identified in 3D than in 2D. We also found that both hemispheres were involved in stereo vision processing and that brain lateralization existed in the processing.


Assuntos
Nível de Alerta , Encéfalo/fisiologia , Cognição , Emoções/fisiologia , Comportamento Espacial/fisiologia , Realidade Virtual , Percepção Visual/fisiologia , Adulto , Percepção de Profundidade , Feminino , Humanos , Masculino , Estimulação Luminosa , Adulto Jovem
10.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 29(4): 1050-1055, 2021 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-34362481

RESUMO

OBJECTIVE: To investigate the effect of sulforaphane (SFN) on G2/M phase arrest of acute myeloid leukemia cells and its molecular mechanism. METHODS: KG1a and KG1cells were treated by different concentrations of SFN for 48 h. Flow cytometry (FCM) was used to analyze the phase distribution of cell cycle. High-throughput sequencing was used to detect the effect of SFN on the expression of cell cycle related genes in KG1a cells. The mRNA expression of P53, P21, CDC2 and CyclinB1 were detected by qPCR. The protein expression of P53, CDC2, P-CDC2 and CyclinB1 were detected by Western blot. RESULTS: Cells in the G2/M phase were increased from 11.9% to 54.0% in KG1a cells and 18.5% to 83.3% in KG1 cells after treated by SFN (8 µ mol / L) for 48 hours(P<0.001). KEGG analysis indicated that P53 pathway was enriched in KG1a cells after treated by SFN. The heat-map graph showed that SFN could change the relevant genes of the cell cycle in KG1a cells. After SFN treatment, the mRNA level of P53 and P21 were significantly increased in KG1 and KG1a cells(P<0.05 or P<0.01). The mRNA level of CDC2 showed a decrease trend with the increasing dose of SFN. At the dosage of 8 µmol /L, the mRNA expression levels of CDC2 was significantly lower than that in control group(P<0.05). At the same time, the protein level of P53 was significantly increased in KG1 and kG1a cells after treated by SFN(P<0.05). The protein level of CDC2 showed a decrease trend with the increasing dose of SFN in a dose manner(r=0.9482 and r=0.8977). The protein levels of CDC2 in SFN 8 and 12 µ mol/L groups were significantly lower than that in control group(P<0.05, P<0.01). The protein levels of P-CDC2 was increased. But the change of mRNA and protein level of CyclinB1 was not significant. CONCLUSION: SFN induces leukemia cells to block in G2/M phase by activating P53 signaling pathway, which can inhibit the expression of CDC2 and the activity of CDC2/cyclinB1.


Assuntos
Isotiocianatos , Leucemia Mieloide Aguda , Ciclo Celular , Humanos , Isotiocianatos/farmacologia , Mitose , Sulfóxidos
11.
Neural Comput ; 33(7): 1886-1913, 2021 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-34411267

RESUMO

As an important class of spiking neural networks (SNNs), recurrent spiking neural networks (RSNNs) possess great computational power and have been widely used for processing sequential data like audio and text. However, most RSNNs suffer from two problems. First, due to the lack of architectural guidance, random recurrent connectivity is often adopted, which does not guarantee good performance. Second, training of RSNNs is in general challenging, bottlenecking achievable model accuracy. To address these problems, we propose a new type of RSNN, skip-connected self-recurrent SNNs (ScSr-SNNs). Recurrence in ScSr-SNNs is introduced by adding self-recurrent connections to spiking neurons. The SNNs with self-recurrent connections can realize recurrent behaviors similar to those of more complex RSNNs, while the error gradients can be more straightforwardly calculated due to the mostly feedforward nature of the network. The network dynamics is enriched by skip connections between nonadjacent layers. Moreover, we propose a new backpropagation (BP) method, backpropagated intrinsic plasticity (BIP), to boost the performance of ScSr-SNNs further by training intrinsic model parameters. Unlike standard intrinsic plasticity rules that adjust the neuron's intrinsic parameters according to neuronal activity, the proposed BIP method optimizes intrinsic parameters based on the backpropagated error gradient of a well-defined global loss function in addition to synaptic weight training. Based on challenging speech, neuromorphic speech, and neuromorphic image data sets, the proposed ScSr-SNNs can boost performance by up to 2.85% compared with other types of RSNNs trained by state-of-the-art BP methods.

12.
AMB Express ; 11(1): 121, 2021 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-34424425

RESUMO

Sulforaphane (SFN), an active compound in cruciferous vegetables, has been characterized by its antiproliferative capacity. We investigated the role and molecular mechanism through which SFN regulates proliferation and self-renewal of lung cancer stem cells. CD133+ cells were isolated with MACs from lung cancer A549 and H460 cells. In this study, we found that SFN inhibited the proliferation of lung cancer cells and self-renewal of lung cancer stem cells simultaneously. Meanwhile, the mRNA and protein expressions of Shh, Smo, Gli1 and PHC3 were highly activated in CD133+ lung cancer cells. Compared with siRNA-control group, Knock-down of Shh inhibited proliferation of CD133+ lung cancer cells, and decreased the protein expression of PHC3 in CD133+ lung cancer cells. Knock-down of PHC3 also affected the proliferation and decreased the Shh expression level in CD133+ lung cancer cells. In addition, SFN inhibited the activities of Shh, Smo, Gli1 and PHC3 in CD133+ lung cancer cells. Furthermore, the inhibitory effect of SFN on the proliferation of siRNA-Shh and siRNA-PHC3 cells was weaker than that on the proliferation of siRNA-control cells. Sonic Hedgehog signaling pathway might undergo a cross-talk with PHC3 in self-renewal of lung cancer stem cells. SFN might be an effective new drug which could inhibit self-renewal of lung cancer stem cells through the modulation of Sonic Hedgehog signaling pathways and PHC3. This study could provide a novel way to improve therapeutic efficacy for lung cancer stem cells.

13.
Cells ; 10(5)2021 05 10.
Artigo em Inglês | MEDLINE | ID: mdl-34068767

RESUMO

Asparagine endopeptidase (AEP), also called legumain, is currently the only known cysteine protease that specifically cleaves peptide bonds in asparaginyl residue in the mammalian genome. Since 2003, AEP has been reported to be widely expressed in a variety of carcinomas and is considered a potential therapeutic target. In the following years, researchers intensively investigated the substrates of AEP and the mechanism of AEP in partial tumors. With the identification of substrate proteins such as P53, integrin αvß3, MMP-2, and MMP-9, the biochemical mechanism of AEP in carcinomas is also more precise. This review will clarify the probable mechanisms of AEP in the progression of breast carcinoma, glioblastoma, gastric carcinoma, and epithelial ovarian carcinoma. This review will also discuss the feasibility of targeted therapy with AEP inhibitor (AEPI) in these carcinomas.


Assuntos
Neoplasias da Mama/enzimologia , Cisteína Endopeptidases/metabolismo , Regulação Neoplásica da Expressão Gênica , Neoplasias Ovarianas/enzimologia , Animais , Neoplasias da Mama/patologia , Carcinoma Epitelial do Ovário/enzimologia , Carcinoma Epitelial do Ovário/patologia , Domínio Catalítico , Progressão da Doença , Matriz Extracelular/metabolismo , Feminino , Humanos , Integrina alfaVbeta3/metabolismo , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Metástase Neoplásica , Neoplasias Ovarianas/patologia , Peptídeos/química , Fosfatidilinositol 3-Quinases/metabolismo , Fatores de Risco , Neoplasias Gástricas/enzimologia , Neoplasias Gástricas/patologia , Proteína Supressora de Tumor p53/metabolismo
14.
Int J Med Sci ; 18(11): 2431-2437, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33967621

RESUMO

Objective: Chronic periodontitis is a bone-destructive disease affecting periodontal support structures. Although leptin has a protective effect against periodontitis, the underlying mechanism remains unclear. Therefore, this study aimed to investigate the possible role of leptin by examining its relationship with OPG and RANKL in human gingival tissues obtained from patients with chronic periodontitis. Method: Twenty-two patients with chronic periodontitis were enrolled (10 with moderate periodontitis and 12 with severe periodontitis) in the experimental group, and 12 healthy individuals were enrolled in the control group. Gingival tissue samples were collected, and the protein levels and localization of leptin, OPG, and RANKL were studied using immunohistochemistry (IHC). The staining intensities of leptin, OPG, and RANKL were correlated with the periodontal clinical index. Moreover, real-time quantitative PCR (RT-qPCR) was used to determine OPG and RANKL mRNA levels in gingival fibroblasts stimulated with gradient concentrations of leptin protein in vitro. Result: Leptin, OPG, and RANKL were located in the cytoplasm of gingival epithelial cells and the connective tissue. Leptin was widely and significantly expressed in the control group, whereas it was lightly stained in the severe group. RANKL was lightly stained in the control group, whereas it was widely and significantly expressed in the severe group. The control and the moderate groups had similar OPG levels, which were significantly higher than that in the severe group. Leptin was positively correlated with OPG(r = 0.905, p < 0.01) and negatively correlated with RANKL (r = -0.635, p < 0.01). In vitro low concentrations of leptin led to an increased OPG/RANKL mRNA ratio, whereas the opposite effect was observed at high concentrations. Conclusion: Leptin can regulate OPG and RANKL expression in gingival fibroblasts and may thus play a role in the development of chronic periodontitis by modulating the OPG/RANKL ratio.

15.
ACS Appl Mater Interfaces ; 13(7): 9166-9173, 2021 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-33566561

RESUMO

Due to an extremely diverse phase space, La1-xSrxMnO3, as with other manganites, offers a wide range of tunability and applications including colossal magnetoresistance and use as spin-polarized electrodes. Here, we study an unprecedented, exotic surface reconstruction (6 × 6) in La1-xSrxMnO3 (x = 0.3) observed via low-energy electron diffraction (LEED). Scanning tunneling microscopy (STM) shows the surface is relatively flat, with unit-cell step heights, and X-ray photoelectron spectroscopy (XPS) reveals a strong degree of Sr segregation at the surface. By combining electron diffraction and first-principles computations, we propose that the long-range surface reconstruction consists of a Sr-segregated surface with La (6 × 6) ordering. This study expands our understanding of manganite systems and underscores their ability to form interesting surface reconstructions, driven largely by cation segregation that can potentially be controlled for tuning surface ordering.

16.
Clin Ophthalmol ; 15: 41-47, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33447010

RESUMO

Background/Aims: Effective management of diabetic retinopathy requires multidisciplinary input. We aimed to evaluate the impact of point of care (POC) HbA1c testing as a tool to identify patients most in need of specialist diabetologist input and assess the accuracy and determinants of patients' insight into their glycaemic and blood pressure control. Methods: Forty-nine patients with diabetic retinopathy were recruited from the eye clinic at Great Western Hospital. Patients completed a questionnaire and POC HbA1c and blood pressure values were measured. Statistical analysis was completed with SPSS v23. Results: Mean age was 64.4 years, median interval since the last formal HbA1c reading was 10.2 months and the mean POC HbA1c was 64.1 mmol/mol. HbA1c significantly correlated with the degree of retinopathy. Of the patients, 81.6% had POC readings above the levels recommended by the National Institute for Health and Care Excellence, with only 16.3% having insight into this. Insight to HbA1c levels was predicted by age but not by duration of disease. Fourteen patients (33.3%) identified with high HbA1c readings were referred to secondary diabetic services and 88.8% of patients felt that the test was useful and likely to improve their diabetic control. Conclusion: The majority of patients had poor insight into their diabetes control, with sub-optimal treatment and follow-up. Poor insight is high in younger patients, suggesting that POC HbA1c testing is particularly important in educating younger patients who may be Type 1 diabetics with more severe disease. POC HbA1c represents a cost-effective, reproducible and clinically significant tool for the management of diabetes in an outpatient ophthalmology setting, allowing the rapid recognition of high-risk patients and appropriate referral to secondary diabetic services.

17.
Sci Rep ; 11(1): 2358, 2021 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-33504921

RESUMO

We present a new method for thin-film synthesis of the superconducting A15 phase of vanadium silicide with critical temperature higher than 13 K. Interdiffusion between a metallic vanadium film and the underlying silicon device layer in a silicon-on-insulator substrate, at temperatures between 650 and 750 °C, favors formation of the vanadium-rich A15 phase by limiting the supply of available silicon for the reaction. Energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and X-ray diffraction verify the stoichiometry and structure of the synthesized thin films. We measure superconducting critical currents of more than 106 amperes per square centimeter at low temperature in micron-scale bars fabricated from the material, and an upper critical magnetic field of 20 T, from which we deduce a superconducting coherence length of 4 nm, consistent with previously reported bulk values. The relatively high critical temperature of A15 vanadium silicide is an appealing property for use in silicon-compatible quantum devices and circuits.

18.
Psychother Psychosom ; 90(2): 127-136, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33152729

RESUMO

BACKGROUND: As the fight against the COVID-19 epidemic continues, medical workers may have allostatic load. OBJECTIVE: During the reopening of society, medical and nonmedical workers were compared in terms of allostatic load. METHODS: An online study was performed; 3,590 Chinese subjects were analyzed. Socio-demographic variables, allostatic load, stress, abnormal illness behavior, global well-being, mental status, and social support were assessed. RESULTS: There was no difference in allostatic load in medical workers compared to nonmedical workers (15.8 vs. 17.8%; p = 0.22). Multivariate conditional logistic regression revealed that anxiety (OR = 1.24; 95% CI 1.18-1.31; p < 0.01), depression (OR = 1.23; 95% CI 1.17-1.29; p < 0.01), somatization (OR = 1.20; 95% CI 1.14-1.25; p < 0.01), hostility (OR = 1.24; 95% CI 1.18-1.30; p < 0.01), and abnormal illness behavior (OR = 1.49; 95% CI 1.34-1.66; p < 0.01) were positively associated with allostatic load, while objective support (OR = 0.84; 95% CI 0.78-0.89; p < 0.01), subjective support (OR = 0.84; 95% CI 0.80-0.88; p < 0.01), utilization of support (OR = 0.80; 95% CI 0.72-0.88; p < 0.01), social support (OR = 0.90; 95% CI 0.87-0.93; p < 0.01), and global well-being (OR = 0.30; 95% CI 0.22-0.41; p < 0.01) were negatively associated. CONCLUSIONS: In the post-COVID-19 epidemic time, medical and nonmedical workers had similar allostatic load. Psychological distress and abnormal illness behavior were risk factors for it, while social support could relieve it.


Assuntos
Alostase/fisiologia , Ansiedade/fisiopatologia , COVID-19 , Depressão/fisiopatologia , Pessoal de Saúde , Comportamento de Doença/fisiologia , Satisfação Pessoal , Apoio Social , Estresse Psicológico/fisiopatologia , Adulto , China , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Ocupações
19.
Food Chem ; 337: 127990, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-32919272

RESUMO

A very practical and competitive sensing strategy for the detection of azodicarbonamide in flour samples was developed by using label-free Ag NPs as a colorimetric probe. Well-dispersed Ag NPs in suspension can form aggregates upon reacting with glutathione (GSH) via Ag-SH covalent bonds and electrostatic attraction, with the color changing from bright yellow to red. However, azodicarbonamide can oxidize the -SH of GSH, preventing the aggregation of Ag NPs. Under the optimum conditions, the A550/A398 of Ag NPs is linearly related to the concentration of azodicarbonamide in the range of 0.33 µM to 1.7 µM. The proposed method can be used for the detection of azodicarbonamide in flour, with a detection limit of 0.09 µM and recovery between 95% and 97.4% (RSD < 6%). When the azodicarbonamide concentration reaches 0.33 µM, the color change can be detected by the naked eye.


Assuntos
Compostos Azo/análise , Colorimetria/métodos , Farinha/análise , Análise de Alimentos/métodos , Nanopartículas Metálicas/química , Cor , Aditivos Alimentares/análise , Análise de Alimentos/instrumentação , Glutationa/química , Prata/química
20.
Opt Express ; 28(17): 25263-25277, 2020 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-32907051

RESUMO

In high-speed optical communication, the blind phase search (BPS) algorithm performs carrier phase estimation better but with higher computational complexity (CC), bringing a larger computational burden to the digital signal processing unit. In this paper, a new low-complexity CPE algorithm (DBPS) is proposed for M-ary quadrature amplitude modulation (M-QAM) formats. It uses the BPS algorithm to estimate the compensation phase interval, before using dichotomy to quickly and accurately determine the compensation phase value. Simulation results show the CC (multiplication / addition) of DBPS is reduced by 2.79 / 2.84 (16-QAM), 5.35 / 5.45 (64-QAM), and 2.98 / 3.01 (128-QAM) than that of BPS, and DBPS has a smaller phase tracking error variance. DBPS can relax the limitation of optical communication rate caused by high-speed data operations.

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