Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 5.495
Filtrar
1.
J Proteomics ; 270: 104745, 2023 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-36220543

RESUMO

Grain length is one of the most important rice grain appearance components. To better understand the protein regulated by grain length in indica rice, the tandem mass tag (TMT) labeling combined with LC-MS/MS analysis was used for quantitative identification of differentially regulated proteins by comparing six long-grain cultivars (MeiB, LongfengB, YexiangB, FengtianB, WantaiB, and DingxiangB) to the short-grain cultivar BoB, respectively. A total of 6622 proteins were detected for quantitative analysis by comparing protein content of six long-grain cultivars to the short-grain cultivar, and 715 proteins were significantly regulated, consisting of 336 uniquely over-accumulated proteins and 355 uniquely down-accumulated proteins. KEGG pathway analysis revealed that most of accumulated proteins are involved in metabolic pathways, biosynthesis of secondary metabolites and phenylpropanoid biosynthesis. Four down-accumulated proteins maybe involved in the signaling pathways for grain length regulation. LC-PRM/MS quantitative analysis was used to analyze 10 differentially expressed proteins. The results were almost consistent with the TMT quantitative analysis. qRT-PCR analysis results showed that the transcription level was not always parallel to the protein content. This study identified many novel grain length accumulated proteins through the quantitative proteomics approach, providing candidate genes for further study of grain size regulatory mechanisms. SIGNIFICANCE: Rice grain length is one of the most important characteristics influencing appearance and yield. Six long-grain cultivars (MeiB, LongfengB, YexiangB, FengtianB, WantaiB, and DingxiangB obtained in Guangxi province of China from the 2000s to 2020s) and one short-grain cultivar (BoB obtained in Guangxi province of China in 1980s) were used for comparative analyses. Totally, 715 differentially expressed proteins (DEPs) were identified using TMT-base proteomic analysis. The numbers of DEPs increased as the grain length increased. 4 DEPs may be related to rice's signaling pathways for grain size regulation. A total of 85 DEPs regulated in at least four long-grain cultivars compared with the short-grain cultivar BoB, and 7 proteins were over-accumulated, and 3 proteins were down-accumulated in six long-grain cultivars. These findings provide valuable information to better understand the mechanisms of protein regulation by grain length in rice.


Assuntos
Oryza , Oryza/genética , Oryza/metabolismo , Proteômica/métodos , Cromatografia Líquida , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/metabolismo , Espectrometria de Massas em Tandem , China , Grão Comestível/metabolismo , Transdução de Sinais
2.
J Hazard Mater ; 444(Pt B): 130409, 2023 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-36435045

RESUMO

Microbial transformations, especially the reduction and methylation of Se oxyanion, have gained significance in recent years as effective detoxification methods. Ganoderma lucidum is a typical Se enrichment resource that can reduce selenite to elemental Se and volatile Se metabolites under high selenite conditions. However, the detailed biological processes and reduction mechanisms are unclear. In this study, G. lucidum reduced selenite to elemental Se and further aggregated it into Se nanoparticles with a diameter of < 200 nm, simultaneously accompanied by the production of pungent, odorous, and volatile methyl-selenium metabolites. Tandem mass tag-based quantitative proteomic analysis revealed thioredoxin 1, thioredoxin reductase (NADPH), glutathione reductase, 5-methyltetrahydropteroyltriglutamate-homocysteine methyltransferase, and cystathionine gamma-lyase as proteins involved in selenite reduction and methylation. Furthermore, the high expression of proteins associated with cell structures that prompted cell lysis may have facilitated Se release. The upregulation of proteins involved in the defense reactions was also detected, reflecting their roles in the self-defense mechanism. This study provides novel insights into the vital role of G. lucidum in mediating Se transformation in the biogeochemical Se cycle and contributes to the application of fungi in Se bioremediation.


Assuntos
Fenômenos Biológicos , Reishi , Metilação , Ácido Selenioso , Proteômica
3.
Environ Res ; 216(Pt 3): 114449, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36270531

RESUMO

Acid red 73 (AR73) is a representative dye pollutant that poses a threat to the environment and human health. Effectively removing this type of pollutant by conventional processes is difficult. However, this study found that compared with UV/PDS, UV/O3, and PDS/O3, UV/O3/PDS composite system had the highest degradation effect on AR73. The degradation efficiency in the composite system reached 97.61% within 30 min, and the synergistic coefficients in the composite system were all greater than 1. In the UV/O3/PDS system, ·OH was the main free radical that mainly degrades AR73. The increase of PDS dosage promoted the degradation of AR73, but the increase of O3 dosage was difficult to greatly improve the degradation of AR73 effect. The kinetic model of the apparent reaction rate was determined. The UV/O3/PDS system can efficiently degrade AR73 in a wide range of substrate concentrations and pH levels, and at the same time showed good adaptability to various concentrations of anions (Cl-, CO32-, SO32-, and C2O42-). Under raw water quality, the degradation effect of AR73 was still as high as approximately 90%. The theoretical attack site was obtained by DFT calculation, and the possible degradation pathway of AR73 was proposed based on the GC-MS spectrum and UV-Vis absorption spectrum. The attack of -NN- by ·OH, SO4-, and O3 was proposed to be the main possible degradation pathway for AR73. Therefore, this study further improves the understanding of the UV/O3/PDS system and shows the potential applicability of this system in the treatment of dye wastewater.


Assuntos
Poluentes Químicos da Água , Purificação da Água , Humanos , Cinética , Poluentes Químicos da Água/análise , Peróxido de Hidrogênio , Raios Ultravioleta , Oxirredução
4.
J Environ Manage ; 326(Pt B): 116842, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36436245

RESUMO

Data scarcity has caused enormous problems in non-point pollution predictions and the related source apportionment. In this study, a new framework was developed to undertake the source apportionment at a large-scale and ungauged catchment, by integrating the physically-based model and a surrogate model. The improvements were made, in terms of the application of a physically-based model in an ungauged area for the transfer process and the parametric transplantation process. The new framework was then tested in the Chaohu Lake basin, China. The result suggested that there has been a good match between simulated and observed data. Although the planting industry was the largest emission source with 48.16% of nitrogen (N), itonly contributed 12.61% of N flux to the Chaohu Lake. The ungauged catchments surrounding the Chaohu Lake were identified as non-negligible sources with 8.46% of phosphorus (P) contribution. The rainfall conditions could have great impacts on source apportionment results; e.g., the planting industry contributed from 68.17t of P in dry year to 436.02t in wet year. The new framework could be extended to other large-scale watersheds for source apportionment with data limitations.

5.
Oncol Rep ; 49(1)2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36331036

RESUMO

Subsequently to the publication of the above article and a Corrigendum that was published to indicate corrections made to Fig. 7 (DOI: 10.3892/or.2021.7922; published online on January 5, 2021), a concerned reader drew the Editor's attention to the fact that, comparing between a pair of panels in the Figure, there was an overlapping section of data; moreover, this overlapping section contained apparent anomalies that could not be easily accounted for through a straightforward re­use of one of the data panels. The authors conceded that there was partial duplication between the images shown in Fig. 7B and F, although they were unable to access the related raw data as the experiments had been performed almost 10 years ago. Secondly, the authors informed the Editor that the corresponding author did not know he was on the author list at the time of submission. Although the authors' were granted permission to publish the Corrigendum, the Editor now considers that the paper should be retracted on account of the uncertainties in the presented revised data and the authors' admission concerning the corresponding author. Therefore, this paper has been retracted from the Journal. The authors are in agreement with the decision to retract the article. The Editor apologizes for any inconvenience caused. [Oncology Reports 37: 2751­2760, 2017; DOI: 10.3892/or.2017.5569].

6.
Spectrochim Acta A Mol Biomol Spectrosc ; 286: 121995, 2023 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-36283206

RESUMO

The Ag and MoO3 layer-by-layer sputtering method was employed to fabricate Ag/MoO3 coated on a polystyrene (PS) array (Ag/MoO3@PS), which exhibited excellent surface-enhanced Raman scattering (SERS) activity. The thickness of the MoO3 layer was controlled by changing the sputtering power. The SERS intensity of 4-aminothiophenol (PATP) on Ag/MoO3@PS with a 2 nm thickness of the MoO3 layer was comparable to that on pure Ag coated on the PS array (Ag@PS). This is possible because hot electrons were injected from Ag into the MoO3 layer to enhance the photocatalyst reaction; thus, the SERS spectra of coupled PATP were obtained. The transport of hot electrons rapidly decayed and was blocked with increasing thickness of the MoO3 layer from 2 nm to 9 nm. Thus, the SERS intensity decreased, and interestingly, the b2 mode of PATP decreased and nearly disappeared. This study provides new insight into the control of hot electron reduction for catalytic reduction process monitoring.

7.
Sci Total Environ ; 857(Pt 2): 159442, 2023 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-36252666

RESUMO

This study investigated the potential of ensiling pretreatment fortified with laccase and a lactic acid bacteria (LAB) inoculant on improving the utilization of alfalfa stems for bioethanol production. The alfalfa stems were ensiled with no additives (Con), 0.04 % laccase (LA), a LAB inoculant containing Pediococcus pentosaceus at 1 × 106 fresh weight (FW) and Pediococcus acidilactici at 3 × 105 cfu/g FW (PP), and a combination of LA and PP (LAP) for 120 days. By reshaping the bacterial community structure of alfalfa stem silages toward a higher abundance of Lactobacillus, the addition of laccase and LAB inoculant either alone or in combination facilitated lactic acid fermentation to reduce fermentation losses, as evidenced by low concentrations of ammonia nitrogen (53.7 to 68.9 g/kg total nitrogen) and ethanol (2.63 to 3.55 g/kg dry matter). All additive treatments increased lignocellulose degradation and soluble sugars concentrations of alfalfa stem silages. Due to delignification and polyphenol removal, glucan and xylan conversion (70.3 % vs. 35.7 % and 51.6 % vs. 27.9 %, respectively) and ethanol conversion efficiency (53.9 % vs. 26.4 %) of alfalfa stems were greatly increased by ensiling fortified with LA versus Con, and these variables (79.8 % for glucan, 58.7 % for xylan, and 60.1 % for ethanol conversion efficiency) were further enhanced with a synergistic effect of LA and PP fortification. The spearman correlation analysis revealed that bioethanol fermentation of silage biomass was closely related to ensiling parameters and total phenols. In conclusion, ensiling pretreatment with LA and PP combination offered a feasible way to efficient utilization of alfalfa stems for bioethanol production.


Assuntos
Inoculantes Agrícolas , Medicago sativa , Medicago sativa/metabolismo , Inoculantes Agrícolas/metabolismo , Lacase/metabolismo , Biomassa , Xilanos , Silagem/análise , Silagem/microbiologia , Fermentação , Ácido Láctico/metabolismo , Etanol/análise , Nitrogênio , Glucanos/metabolismo
8.
Bioresour Technol ; 367: 128277, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36356846

RESUMO

In this study, accumulated fermentable sugars from biosaccharified corn straw were used to generate methane through anaerobic digestion (AD). The results showed that reducing sugars from biosaccharification expanded corn straw (BECS) treated with Clostridium thermocellum XF811 accumulated with yields of 94.9 mg/g. The BECS used for AD was converted into a high methane yield (7436 mL), which was 49.3 % higher than that of expanded corn straw (ECS). High-throughput microbial analysis suggested that Methanoculleus and Methanobacterium greatly contributed to the high methane yield. Industrial experiments demonstrated that the methane production from BECS by AD was 72,955 m3, which increased by 13.2 % compared to that from ECS. Biosaccharification pretreatment accelerated ECS destruction and accumulated sugars, thereby increasing methane yields. This study provides a strategy for producing clean energy from lignocellulose biomass.


Assuntos
Metano , Zea mays , Anaerobiose , Biomassa , Açúcares , Biocombustíveis
9.
Chemosphere ; 310: 136937, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36273608

RESUMO

The fabrication of metal-carbon hybrids with heteroatom doping from manganese-metal organic frameworks (MOFs) has rarely been reported for peroxymonosulfate (PMS) activation. In this work, novel MnOx@N-doped carbon (MnOx@NC) nanosheets were prepared using 2D manganese-1,4 benzenedicarboxylic acid-based MOFs (Mn-MOFs) and different proportions of graphitic carbon nitride (g-C3N4, additional N source and carbon source) to activate PMS for sulfamethoxazole (SMX) removal. The polarization difference induced by Mn-N coordination during the carbonization process made C an electron-poor center and Mn an electron-rich center, thus providing more Mn(II) for PMS activation. Benefiting from the highest Mn(II) content, the most uniform and exposed MnOx active sites, abundant N active species and rich defective sites, MnOx@NC-20 showed excellent degradation (72.9% within 5 min) and mineralization performance (47.40% within 60 min) for SMX. Nonradical and radical processes worked together in MnOx@NC-20/PMS/SMX system, where singlet oxygen (1O2) dominated the degradation of SMX. N-doped carbon not only exhibited dragging and protection effects on MnOx, but also provided adsorption sites for PMS and pollutants, thus reducing their migration distance. Moreover, the electrons of organic substrates could be captured by the electron-poor carbon layer and then transported to the electron-rich Mn center, thus improving the utilization efficiency of PMS and the redox of Mn. This study provides a facile optimization method to prepare MOFs-derived carbon catalysts with improved stability and catalytic performance.


Assuntos
Carbono , Estruturas Metalorgânicas , Carbono/química , Elétrons , Manganês , Peróxidos/química , Sulfametoxazol
10.
J Environ Manage ; 325(Pt A): 116491, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36265232

RESUMO

Nonpoint source (NPS) pollution shows spatial scaling effects because it is affected by topography, river networks, and many other factors. Currently, the lack of an integrated methodology for quantifying the scaling effect has become a crucial barrier in evaluating NPS pollution. In this study, a new method was proposed for scaling NPS pollution by integrating hydrological model and hydrological alteration indicators. Nested catchments were delineated by eight-direction algorithm, and a semidistributed hydrological model was used to simulate the interannual process within the drainage area and to obtain data series of runoff, sediment, and total phosphorus (TP) at different spatial scales. In addition, the average, the extrema, the change rate and feature variables of each type of indicators were proposed to quantitatively describe the pattern of NPS pollution at different spatial scales. The results show the coefficients of variation (CVs) of most runoff and TP indicators are 0.6-0.8, while those of sediment vary greatly from 0.4 to 1.6 with the threshold of those indicators being 0.33. With the increase in drainage area, the NPS load-related indicators show an increasing trend, while load intensity indicators show a decreasing trend and their changing patterns are affected by the heterogeneity of topographic or hydrological information included. Based on logarithmic variance of the change rate, 825 km2 was identified as the turning point for scaling transformation where the slope changes dramatically. The proposed methodology comprehensively describes features of the NPS scaling effect that could be utilized for targeted monitoring and control of NPS pollution in other watersheds.


Assuntos
Poluição Difusa , Poluentes Químicos da Água , Poluição Difusa/análise , Monitoramento Ambiental/métodos , Poluentes Químicos da Água/análise , Nitrogênio/análise , Rios , Fósforo/análise , China
11.
Carbohydr Polym ; 301(Pt B): 120324, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36446491

RESUMO

Hemostats that can strongly adhere to wound tissue and are easy to remove when stopping bleeding are favored for the control of noncompressible hemorrhage. Here, we prepared a citric acid (CA)-crosslinked and N-hydroxysuccinimide (NHS) ester-activated carboxymethyl cellulose (CMC-NHS) aerogel for noncompressible hemostasis. CA was used to crosslink CMC to form a strengthened structure. NHS ester was introduced to activate the adhesion of CMC-NHS aerogel to wound tissue and promoted blood coagulation through the formation of amide crosslinks between CMC and erythrocytes and free blood proteins. The plentiful carboxyl groups could also trigger the intrinsic coagulation pathway. Thus, the aerogel could quickly adhere to wound tissue to stop bleeding, and then could be easily removed when fully hydrated as CMC was dissolved at the adhesion interface. The aerogel also had good biocompatibility and antibacterial capability. Overall, CMC-NHS aerogel is a competitive hemostat for the control of noncompressible hemorrhage.


Assuntos
Adesivos , Carboximetilcelulose Sódica , Humanos , Hemorragia , Coagulação Sanguínea , Ésteres
12.
Mater Today Bio ; 18: 100500, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36471893

RESUMO

Polymethyl methacrylate (PMMA) bone cement (PBC) is commonly used in orthopaedic surgery. However, polymerization volumetric shrinkage, exothermic injury, and low bioactivity prevent PBC from being an ideal material. The developed expandable P(MMA-AA-St) well overcomes the volumetric shrinkage of PBC. However, its biomechanical properties are unsatisfactory. Herein, graphene oxide (GO), a hydrophilic material with favourable biomechanics and osteogenic capability, was added to P(MMA-AA-St) to optimize its biomechanics and bioactivity. The GO-modified self-expandable P(MMA-AA-St)-GO nanocomposite (PGBCs) exhibited outstanding compressive strength (>70 â€‹MPa), water absorption, and volume expansion, as well as a longer handling time and a reduced setting temperature. The cytocompatibility of PGBCs was superior to that of PBC, as demonstrated by CCK-8 assay, live-dead cell staining, and flow cytometry. In addition, better osteoblast attachment was observed, which could be attributed to the effects of GO. The improved level of osteogenic gene and protein expression further illustrated the improved cell-material interactions between osteoblasts and PGBCs. The results of an in vivo study performed by filling bone defects in the femoral condyles of rabbits with PGBCs demonstrated promising intraoperative handling properties and convenient implantation. Blood testing and histological staining demonstrated satisfactory in vivo biosafety. Furthermore, bone morphological and microarchitecture analyses using bone tissue staining and micro-CT scanning revealed better bone-PGBCs contact and osteogenic capability. The results of this study indicate that GO modification improved the physiochemical properties, cytocompatibility, and osteogenic capability of P(MMA-AA-St) and overcame the drawbacks of PBC, allowing its material derivatives to serve as effective implantable biomaterials.

13.
Front Bioeng Biotechnol ; 10: 1052785, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36452206

RESUMO

Polyunsaturated fatty acids (PUFAs) are important nutrients that play important roles in human health. In eukaryotes, PUFAs can be de novo synthesized through two independent biosynthetic pathways: the desaturase/elongase pathway and the PUFA synthase pathway. Among them, PUFAs synthesized through the PUFA synthase pathway typically have few byproducts and require fewer reduction equivalents. In the past 2 decades, numerous studies have been carried out to identify, analyze and engineer PUFA synthases from eukaryotes. These studies showed both similarities and differences between the eukaryotic PUFA synthase pathways and those well studied in prokaryotes. For example, eukaryotic PUFA synthases contain the same domain types as those in prokaryotic PUFA synthases, but the number and arrangement of several domains are different; the basic functions of same-type domains are similar, but the properties and catalytic activities of these domains are somewhat different. To further utilize the PUFA synthase pathway in microbial cell factories and improve the productivity of PUFAs, many challenges still need to be addressed, such as incompletely elucidated PUFA synthesis mechanisms and the difficult genetic manipulation of eukaryotic hosts. In this review, we provide an updated introduction to the eukaryotic PUFA synthase pathway, summarize the functions of domains and propose the possible mechanisms of the PUFA synthesis process, and then provide future research directions to further elucidate and engineer the eukaryotic PUFA synthase pathway for the maximal benefits of humans.

14.
Carcinogenesis ; 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-36455232

RESUMO

CCL18 has recently been implicated in malignancies and is increasingly mentioned as a potential tumoral biomarker and furtherly a molecular target for therapeutic intervention, but its expression and clinical significance in multiple myeloma have not been explored. Serum CCL18 levels were measured by ELISA method in 254 newly diagnosed multiple myeloma (NDMM), 21 monoclonal gammopathy of undetermined significance (MGUS) and 22 healthy adults. The study suggests that the serum CCL18 level in NDMM patients was significantly higher than that in MGUS and healthy adults. High level of CCL18 were associated with advanced ISS and R-ISS stages in MM. Patients with high serum CCL18 displayed a significantly more frequent occurrence of renal impairment and hypercalcemia, while the proportion of achieving complete remission (CR) was lower. More importantly, Cox analysis identified CCL18 and LDH as independent predictors of PFS in MM patients, whereas CCL18, creatinine and LDH were independent predictors of OS. Finally, we show that CCL18 can promote migration and invasion of myeloma cell lines RPMI8226 and MM.1S. CCL18 may play a tumor-promoting role by increasing the migration and invasion abilities of myeloma cells.

15.
Sex Health ; 2022 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-36455597

RESUMO

BACKGROUND: Syphilitic vasculitis (SV) is rare and difficult to be diagnosed. High-resolution vessel wall magnetic resonance imaging (HR-VWI) might be valuable in the diagnosis by differentiating SV from other vessel wall pathologies. METHODS: We report a rare case with severe isolated middle cerebral artery (MCA) stenosis and cerebral infarction, which was evaluated by serial HR-VWI. RESULTS: A 46-year-old woman presented with an acute infarct in the left basal ganglia and severe isolated stenosis in left middle cerebral artery (MCA). Cerebrospinal fluid (CSF) analysis was performed and the findings were consistent with neurosyphilis diagnosis. The MCA stenosis was also suspected to be the result of SV. HR-VWI revealed the evidence of concentric thickening and circular uniform enhancement of the arterial wall. After two cycles of anti-syphilis treatment, subsequent HR-VWI showed that the MCA stenosis was reduced significantly except slight enhancement of the arterial wall, which confirmed that the SV caused the isolated MCA stenosis. CONCLUSIONS: HR-VWI could be an important diagnostic tool for isolated middle cerebral artery stenosis caused by SV, which could serve as a biomarker for assessing the response to anti-syphilis treatment in the future.

16.
Artigo em Inglês | MEDLINE | ID: mdl-36458883

RESUMO

CONTEXT: Previous studies suggest that the complexity of glucose time series may serve as a novel marker of glucose homeostasis. OBJECTIVE: We aimed to investigate the relationship between the complexity of glucose time series and all-cause mortality in patients with type 2 diabetes. METHODS: Prospective data of 6000 adult inpatients with type 2 diabetes from a single center was analyzed. The complexity of glucose time series index (CGI) based on continuous glucose monitoring (CGM) was measured at baseline with refined composite multi-scale entropy. Participants were stratified by the tertiles of CGI: < 2.15, 2.15-2.99, and ≥ 3.00. Cox proportional hazards regression models were used to assess the relationship between CGI and all-cause mortality. RESULTS: During a median follow-up of 9.4 years, 1217 deaths were identified. A significant interaction between glycated hemoglobin A1c (HbA1c) and CGI in relation to all-cause mortality was noted (P for interaction = 0.016). The multivariable-adjusted hazard ratios for all-cause mortality at different CGI levels [≥ 3.00 (reference group), 2.15-2.99, and < 2.15] were 1.00, 0.76 (95% CI 0.52-1.12), and 1.47 (95% CI 1.03-2.09) in patients with HbA1c < 7.0%, while the association was nonsignificant in those with HbA1c ≥ 7.0%. The restricted cubic spline regression revealed a non-linear (P for non-linearity = 0.041) relationship between CGI and all-cause mortality in subjects with HbA1c < 7.0% only. CONCLUSIONS: Lower CGI is associated with an increased risk of all-cause mortality among patients with type 2 diabetes achieving the HbA1c target. CGI may be a new indicator for the identification of residual risk of death in well-controlled type 2 diabetes.

17.
ACS Sens ; 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-36454224

RESUMO

Owing to the unique electronic spin properties, nitrogen-vacancy (NV) centers hosted in diamond have emerged as a powerful quantum tool for detecting various physical parameters and biological species. In this work, an optical-fiber quantum probe, configured by chemically modifying nanodiamonds on the surface of a cone fiber tip, is developed. Based on the continuous-wave optically detected magnetic resonance method and lock-in amplification technique, it is found that the sensing performance of probes can be engineered by varying the nanodiamond dispersion concentration and modification duration during the chemical modification process. Combined with a pair of magnetic flux concentrators, the magnetic field detection sensitivity has reached 0.57 nT/Hz1/2@1 Hz, a new record among the fiber magnetometers based on nanodiamonds. Taking Gd3+ as the demo, the capability of probes in paramagnetic species detection is also demonstrated experimentally. Our work provides a new approach to develop NV centers as quantum probes featuring high integration, multifunction, high sensitivity, etc.

18.
Metab Brain Dis ; 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-36454502

RESUMO

The globus pallidus has emerged as a crucial node in the basal ganglia motor control circuit under both healthy and parkinsonian states. Previous studies have shown that angiotensin II (Ang II) and angiotensin subtype 1 receptor (AT1R) are closely related to Parkinson's disease (PD). Recent morphological study revealed the expression of AT1R in the globus pallidus of mice. To investigate the functions of Ang II/AT1R on the globus pallidus neurons of both normal and parkinsonian rats, electrophysiological recordings and behavioral tests were performed in the present study. Electrophysiological recordings showed that exogenous and endogenous Ang II mainly excited the globus pallidus neurons through AT1R. Behavioral tests further demonstrated that unilateral microinjection of Ang II into the globus pallidus induced significantly contralateral-biased swing in elevated body swing test (EBST), and bilateral microinjection of Ang II into the globus pallidus alleviated catalepsy and akinesia caused by haloperidol. AT1R was involved in Ang II-induced behavioral effects. Immunostaining showed that AT1R was expressed in the globus pallidus of rats. On the basis of the present findings, we concluded that pallidal Ang II/AT1R alleviated parkinsonian motor deficits through activating globus pallidus neurons, which will provide a rationale for further investigations into the potential of Ang II in the treatment of motor disorders originating from the basal ganglia.

19.
Anal Chem ; 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-36454685

RESUMO

As observed in the COVID-19 pandemic, RNA viruses continue to rapidly evolve through mutations. In the absence of effective therapeutics, early detection of new severely pathogenic viruses and quarantine of infected people are critical for reducing the spread of the viral infections. However, conventional detection methods require a substantial amount of time to develop probes specific to new viruses, thereby impeding immediate response to the emergence of viral pathogens. In this study, we identified multiple types of viruses by obtaining the spectral fingerprint of their surface proteins with probe-free surface-enhanced Raman scattering (SERS). In addition, the SERS-based method can remarkably distinguish influenza virus variants with several surface protein point mutations from their parental strain. Principal component analysis (PCA) of the SERS spectra systematically captured the key Raman bands to distinguish the variants. Our results show that the combination of SERS and PCA can be a promising tool for rapid detection of newly emerging mutant viruses without a virus-specific probe.

20.
Rev Sci Instrum ; 93(11): 113312, 2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-36461542

RESUMO

During the radiographic testing with multiple voltage exposures, the problem of image redundancy has serious influences on the speed of analysis. In this paper, by the calculation of spatial entropy and the extraction of microtopography features, a new segmentation method for an unpredictable free-form surface in turbine blades is presented to reduce the testing redundancy. First, the entropy calculation is applied to a set of radiography images of the target object. The optimized image for surface segmentation is determined according to global entropy values and exposure parameters. Then, the obtained image is set as the reference image for the segmentation process. Through the spatial entropy calculation, the reference radiographic image is divided into several regions by geometric features of the tested object. The different thickness range of free-form surfaces is indicated by those regions through the analysis of spatial entropy distribution in the reference image. By the statistical advantage of entropy calculation, the selected region is self-adaptive to the unpredictable free-form surface in the blade. A nickel-based alloy turbine blade is used to validate the segmentation method in the radiographic testing. The processed image quality is assessed by using the American Society for Testing and Materials image quality indicator to address its capability for the detection of defects, where the resolution of the image is not affected by the down-sampled effect of entropy calculation. The experimental results show that the image redundancy in the multiple exposure testing is reduced to less than 30% during the inline testing, while the dynamic range in each extracted region with an optimal image is significantly improved.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...