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1.
J Magn Reson Imaging ; 59(4): 1373-1381, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37496196

RESUMO

BACKGROUND: Ketamine is a quick acting antidepressant drug, and an accurate detection method is lacking. Ketamine's effects in a rat depression model have not previously been well explored using glutamate chemical exchange saturation transfer (GluCEST). PURPOSE: To investigate the GluCEST changes of chronic unpredictable mild stress (CUMS) rats after receiving either ketamine or saline injection. STUDY TYPE: Randomized animal model trial. ANIMAL MODEL: 12 CUMS and 6 Sprague-Dawley rats. Divided into three groups: ketamine (N = 6), saline (N = 6), and control (N = 6). FIELD STRENGTH/SEQUENCE: 7.0 T/the sequence is GluCEST and 1 H MR spectroscopy (MRS). ASSESSMENT: The CUMS rats were exposed to different stress factors for 8 weeks. The glutamate concentration in the hippocampus was assessed by the GluCEST,1 H MRS, and the high-performance liquid chromatography (HPLC). STATISTICAL TESTS: The t-test, Mann-Whitney U test, and Pearson's correlation. RESULTS: In depression conditions, GluCEST signals were lower in the bilateral hippocampus than in control group. Thirty minutes after ketamine injection, the GluCEST signals in the bilateral hippocampus were higher compared with the saline group (left: 2.99 ± 0.34 [Control] vs. 2.44 ± 0.20 [Saline] vs. 2.85 ± 0.11 [Ketamine]; right: 2.97 ± 0.28 [Control] vs. 2.49 ± 0.25 [Saline] vs. 2.86 ± 0.19 [Ketamine]). In 1 H MRS, significant changes were only observed in the left hippocampus (2.00 ± 0.16 [Control] vs. 1.81 ± 0.09 [Saline] vs. 2.04 ± 0.14 [Ketamine]). Furthermore, HPLC results showed similar trends to those observed in the GluCEST results (left: 2.32 ± 0.22 [Control] vs. 1.96 ± 0.11 [Saline] vs. 2.18 ± 0.11 [Ketamine]; right: 2.35 ± 0.18 [Control] vs. 1.87 ± 0.16 [Saline] vs. 2.09 ± 0.08 [Ketamine]). DATA CONCLUSION: GluCEST can sensitively evaluate the ketamine's antidepressant effects by detecting the fast increase in glutamate concentration. LEVEL OF EVIDENCE: 1 TECHNICAL EFFICACY STAGE: 1.


Assuntos
Ketamina , Ratos , Animais , Ketamina/farmacologia , Ketamina/uso terapêutico , Depressão/tratamento farmacológico , Ácido Glutâmico , Ratos Sprague-Dawley , Antidepressivos/farmacologia , Antidepressivos/uso terapêutico , Hipocampo/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos
2.
J Magn Reson Imaging ; 2024 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-38970314

RESUMO

BACKGROUND: Abnormal levels of glutamate constitute a key pathophysiologic mechanism in epilepsy. The use of glutamate chemical exchange saturation transfer (GluCEST) imaging to measure glutamate levels in pediatric epilepsy is rarely reported in research. PURPOSE: To investigate hippocampal glutamate level variations in pediatric epilepsy and the correlation between glutamate and hippocampal subregional volumes. STUDY TYPE: Cross-sectional, prospective. SUBJECTS: A total of 38 school-aged pediatric epilepsy patients with structurally normal MRI as determined by at least two independent radiologists (60% males; 8.7 ± 2.5 years; including 20 cases of focal pediatric epilepsy [FE] and 18 cases of generalized pediatric epilepsy [GE]) and 17 healthy controls (HC) (41% males; 9.0 ± 2.5 years). FIELD STRENGTH/SEQUENCE: 3.0 T; 3D magnetization prepared rapid gradient echo (MPRAGE) and 2D turbo spin echo GluCEST sequences. ASSESSMENT: The relative concentration of glutamate was calculated through pixel-wise magnetization transfer ratio asymmetry (MTRasym) analysis of the GluCEST data. Hippocampal subfield volumes were computed from MPRAGE data using FreeSurfer. STATISTICAL TESTS: This study used t tests, one-way analysis of variance, Kruskal-Wallis tests, and Pearson correlation analysis. P < 0.05 was considered statistically significant. RESULTS: The MTRasym values of both the left and right hippocampi were significantly elevated in GE (left: 2.51 ± 0.23 [GE] vs. 2.31 ± 0.12 [HCs], right: 2.50 ± 0.22 [GE] vs. 2.27 ± 0.22 [HCs]). The MTRasym values of the ipsilateral hippocampus were significantly elevated in FE (2.49 ± 0.28 [ipsilateral] vs. 2.29 ± 0.16 [HCs]). The MTRasym values of the ipsilateral hippocampus were significantly increased compared to the contralateral hippocampus in FE (2.49 ± 0.28 [ipsilateral] vs. 2.35 ± 0.34 [contralateral]). No significant differences in hippocampal volume were found between different groups (left hippocampus, P = 0.87; right hippocampus, P = 0.87). DATA CONCLUSION: GluCEST imaging have potential for the noninvasive measurement of glutamate levels in the brains of children with epilepsy. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY: Stage 1.

3.
Sensors (Basel) ; 24(3)2024 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-38339709

RESUMO

Multi-channel and multi-parameter near-infrared spectroscopy (NIRS) has gradually become a new research direction and hot spot due to its ability to provide real-time, continuous, comprehensive indicators of multiple parameters. However, multi-channel and multi-parameter detection may lead to crosstalk between signals. There is still a lack of benchmarks for the evaluation of the reliability, sensitivity, stability and response consistency of the NIRS instruments. In this study, a set of test methods (a human blood model test, ink drop test, multi-channel crosstalk test and multi-parameter crosstalk test) for analyzing crosstalk and verifying the reliability of NIRS was conducted to test experimental verification on a multi-channel (8-channel), multi-parameter (4-parameter) NIRS instrument independently developed by our team. Results show that these tests can be used to analyze the signal crosstalk and verify the reliability, sensitivity, stability and response consistency of the NIRS instrument. This study contributes to the establishment of benchmarks for the NIRS instrument crosstalk and reliability testing. These novel tests have the potential to become the benchmark for NIRS instrument reliability testing.

4.
Planta ; 257(6): 116, 2023 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-37171508

RESUMO

MAIN CONCLUSION: Soil water content only affected regeneration time, whereas the NSC content was related to the success of alfalfa regeneration. Non-structural carbohydrates (NSCs) are important factors influencing the overwintering and regeneration of alfalfa. In this study, we analyzed eight in-situ samplings at three depths of coarse roots (crown, 20 and 40 cm depths) during the overwintering period and assessed the dynamic change and allocation of root NSCs under three irrigation frequencies (irrigation once every second day/4 days/8 days). Primary results showed that: (i) before cold acclimation, irrigation once every second day was beneficial to the accumulation of soluble sugars and starch in crown tissues, which would be maintained until the following spring and accelerate the regeneration time of alfalfa; (ii) during the overwintering process, the soluble sugars and starch contents in the crown were significantly higher than those in deeper roots, and there was an asynchronous effect caused by the change in soluble sugars and starch among roots at three depths; and (iii) the change trend of soluble sugar and starch contents was consistent with that of semi-lethal temperature, and there was a significant negative correlation between the content of soluble sugar (R2 = 0.8046) and starch (R2 = 0.6332) and the semi-lethal temperature. This study demonstrated that NSCs are the key driver of cold tolerance and regeneration under the three irrigation frequencies evaluated. Our results provide further insight into the allocation of NSCs in winter. This improved understanding of the mechanism of overwintering will allow for improved water management of alfalfa in high latitude areas.


Assuntos
Medicago sativa , Raízes de Plantas , Carboidratos , Açúcares , Amido , Água
5.
J Magn Reson Imaging ; 58(5): 1431-1440, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-36808678

RESUMO

BACKGROUND: Glutamate dysregulation is one of the key pathogenic mechanisms of major depressive disorder (MDD), and glutamate chemical exchange saturation transfer (GluCEST) has been used for glutamate measurement in some brain diseases but rarely in depression. PURPOSE: To investigate the GluCEST changes in hippocampus in MDD and the relationship between glutamate and hippocampal subregional volumes. STUDY TYPE: Cross-sectional. SUBJECTS: Thirty-two MDD patients (34% males; 22.03 ± 7.21 years) and 47 healthy controls (HCs) (43% males; 22.00 ± 3.28 years). FIELD STRENGTH/SEQUENCE: 3.0 T; magnetization prepared rapid gradient echo (MPRAGE) for three-dimensional T1-weighted images, two-dimensional turbo spin echo GluCEST, and multivoxel chemical shift imaging (CSI) for proton magnetic resonance spectroscopy (1 H MRS). ASSESSMENT: GluCEST data were quantified by magnetization transfer ratio asymmetry (MTRasym ) analysis and assessed by the relative concentration of 1 H MRS-measured glutamate. FreeSurfer was used for hippocampus segmentation. STATISTICAL TESTS: The independent sample t test, Mann-Whitney U test, Spearman's correlation, and partial correlation analysis were used. P < 0.05 was considered statistically significant. RESULTS: In the left hippocampus, GluCEST values were significantly decreased in MDD (2.00 ± 1.08 [MDD] vs. 2.62 ± 1.41 [HCs]) and showed a significantly positive correlation with Glx/Cr (r = 0.37). GluCEST values were significantly positively correlated with the volumes of CA1 (r = 0.40), subiculum (r = 0.40) in the left hippocampus and CA1 (r = 0.51), molecular_layer_HP (r = 0.50), GC-ML-DG (r = 0.42), CA3 (r = 0.44), CA4 (r = 0.44), hippocampus-amygdala-transition-area (r = 0.46), and the whole hippocampus (r = 0.47) in the right hippocampus. Hamilton Depression Rating Scale scores showed significantly negative correlations with the volumes of the left presubiculum (r = -0.40), left parasubiculum (r = -0.47), and right presubiculum (r = -0.41). DATA CONCLUSION: GluCEST can be used to measure glutamate changes and help to understand the mechanism of hippocampal volume loss in MDD. Hippocampal volume changes are associated with disease severity. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY: Stage 1.


Assuntos
Transtorno Depressivo Maior , Masculino , Humanos , Feminino , Transtorno Depressivo Maior/diagnóstico por imagem , Ácido Glutâmico , Estudos Transversais , Depressão , Hipocampo/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos
6.
Eur Radiol ; 33(6): 4214-4222, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36600123

RESUMO

OBJECTIVES: To elucidate the change in glutamate levels in preterm infants at different gestational ages by glutamate chemical exchange saturated transfer (GluCEST) magnetic resonance imaging and to compare the difference in glutamate levels among different brain regions between very early preterm infants and middle and late preterm infants. METHODS: Fifty-three preterm infants (59% males; median gestational age = 33.6 weeks) underwent MRI, including conventional MRI and GluCEST. The original data were postprocessed in MATLAB. Correlation analysis was used to determine the relationship between the MTRasym and gestational age. The differences in MTRasym signals among different ROIs were statistically analysed by one-way analysis of variance (ANOVA). The MTRasym difference of the bilateral hemispherical ROI was compared by a paired T test. RESULTS: In all ROIs, glutamate concentration was positively correlated with gestational age. The glutamate concentration in the thalamus was higher than that in the frontal lobe in very early, middle and late preterm infants. A difference in glutamate concentration was not found in the bilateral ROIs. CONCLUSIONS: The concentration of glutamate in the brains of preterm infants of different gestational ages increased with gestational age, which may be one of the factors contributing to the higher incidence of neurodevelopmental dysfunction in very early preterm infants compared to that in middle and late preterm infants. Meanwhile, the glutamate concentrations among different brain regions were also diverse. KEY POINTS: • The glutamate concentration was positively correlated with gestational age in preterm infants of the brain. • Glutamate concentrations were dissimilar in different brain regions of preterm infants. • Glutamate concentration during the process of brain development in premature infants was not found to be asymmetric.


Assuntos
Doenças do Prematuro , Recém-Nascido Prematuro , Lactente , Masculino , Recém-Nascido , Humanos , Feminino , Idade Gestacional , Projetos Piloto , Ácido Glutâmico , Encéfalo/diagnóstico por imagem , Encéfalo/patologia
7.
Appl Opt ; 62(18): 4971-4977, 2023 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-37707275

RESUMO

In this paper, the voltage-transmittance curvesKDP crystals were measured accurately between two crossed or parallel polarizers using longitudinal electro-optic effect. The end faces of rectangular KDP samples were coated with ring-shaped electrodes using conductive silver paint (CSP). The change of half period voltage U i has been investigated. A method for quantitative characterization of residual stress has been proposed, based on deviation voltage U d. The results demonstrate that loading voltage is close to the integration of electric field intensity in crystal along the optical path when the CSP ring electrodes have a large outer radius R, small inner radius r, and long-distance d. The half-period voltage U i is also close to longitudinal half-wave voltage U π in these circumstances. The unclamped electro-optic coefficient γ63σ of KDP crystal at room temperature was measured as 10.24±0.05p m/V at the wavelength of 632.8 nm.

8.
Proc Biol Sci ; 289(1984): 20221641, 2022 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-36476002

RESUMO

The genus Sinocyclocheilus, comprising a large radiation of freshwater cavefishes, are well known for their presence of regressive features (e.g. variable eye reduction). Fewer constructive features are known, such as the expansion of the lateral line system (LLS), which is involved in detecting water movements. The precise relationship between LLS expansion and cave adaptation is not well understood. Here, we examine morphology and LLS-mediated behaviour in Sinocyclocheilus species characterized by broad variation in eye size, habitat and geographical distribution. Using live-staining techniques and automated behavioural analyses, we examined 26 Sinocyclocheilus species and quantified neuromast organ number, density and asymmetry within a phylogenetic context. We then examined how these morphological features may relate to wall-following, an established cave-associated behaviour mediated by the lateral line. We show that most species demonstrated laterality (i.e. asymmetry) in neuromast organs on the head, often biased to the right. We also found that wall-following behaviour was distinctive, particularly among eyeless species. Patterns of variation in LLS appear to correlate with the degree of eye loss, as well as geographical distribution. This work reveals that constructive LLS evolution is convergent across distant cavefish taxa and may mediate asymmetric behavioural features that enable survival in stark subterranean microenvironments.


Assuntos
Cipriniformes , Animais , Filogenia
9.
Molecules ; 27(12)2022 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-35745073

RESUMO

This study presents the construction and dielectric properties investigation of atomic-layer-deposition Al2O3/TiO2/HfO2 dielectric-film-based metal-insulator-metal (MIM) capacitors. The influence of the dielectric layer material and thickness on the performance of MIM capacitors are also systematically investigated. The morphology and surface roughness of dielectric films for different materials and thicknesses are analyzed via atomic force microscopy (AFM). Among them, the 25 nm Al2O3-based dielectric capacitor exhibits superior comprehensive electrical performance, including a high capacitance density of 7.89 fF·µm-2, desirable breakdown voltage and leakage current of about 12 V and 1.4 × 10-10 A·cm-2, and quadratic voltage coefficient of 303.6 ppm·V-2. Simultaneously, the fabricated capacitor indicates desirable stability in terms of frequency and bias voltage (at 1 MHz), with the corresponding slight capacitance density variation of about 0.52 fF·µm-2 and 0.25 fF·µm-2. Furthermore, the mechanism of the variation in capacitance density and leakage current might be attributed to the Poole-Frenkel emission and charge-trapping effect of the high-k materials. All these results indicate potential applications in integrated passive devices.

10.
J Magn Reson Imaging ; 53(5): 1550-1558, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33851471

RESUMO

Previous studies on the value of radiomics for diagnosing clinically significant prostate cancer (csPCa) only utilized intralesional features. However, the role of tumor microenvironment is important in tumor generation and progression. The aim of this study is to build and validate a nomogram based on perilesional and intralesional radiomics features and clinical factors for csPCa. This is a retrospective study, which included 140 patients who underwent prostate magnetic resonance imaging (MRI). This study used 3.0T T2-weighted imaging, apparent diffusion coefficient maps (derived from diffusion-weighted images), and dynamic contrast-enhanced MRI. Region of interest (ROI)s were segmented by two radiologists. Intralesional and combined radiomics signatures were built based on radiomics features extracted from intralesional and the combination of radiomics features extracted from intralesional and perilesional volumes. Serum total prostate-specific antigen level and combined radiomics signature scores were used to construct a diagnostic nomogram. Intraclass correlation efficient analysis was used to test intra- and inter-rater agreement of radiomics features. Min-max scalar was used for normalization. One-way analysis of variance or the Mann-Whitney U-test was used for univariate analysis. Receiver operating characteristic curve analysis, accuracy, balanced accuracy, and F1-score were used to evaluate radiomics signatures and the nomogram. Also, the nomogram was evaluated using decision curve analysis in testing cohort. Delong test was used to compare area under the curves (AUCs). Statistical significance was set at p < 0.05. In testing cohort, AUC, accuracy, balanced accuracy, and F1-score of combined radiomics signature (0.94, 0.83, 0.80, and 0.87, respectively) were all higher than that of intralesional radiomics signature (0.90, 0.77, 0.74, and 0.83, respectively). The difference between AUCs was insignificant (p of 0.19). AUC, accuracy, balanced accuracy, and F1-score of the nomogram were 0.96, 0.94, 0.95, and 0.95, respectively. Nomogram was clinically useful when threshold probability of a patient is higher than 0.06. Perilesional radiomics features improved the discrimination ability of the radiomics signature. Diagnostic nomogram had a good performance. LEVEL OF EVIDENCE: 3. TECHNICAL EFFICACY STAGE: 2.


Assuntos
Nomogramas , Neoplasias da Próstata , Humanos , Imageamento por Ressonância Magnética , Masculino , Neoplasias da Próstata/diagnóstico por imagem , Estudos Retrospectivos , Microambiente Tumoral
11.
J Magn Reson Imaging ; 54(6): 1967-1976, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34291854

RESUMO

BACKGROUND: Adjusting abnormal glutamate neurotransmission is a crucial mechanism in the treatment of depression. However, few non-invasive techniques could effectively detect changes in glutamate neurotransmitters, and no consensus exists on whether glutamate could affect resting-state function changes in depression. PURPOSE: To study the changes in glutamate chemical exchange saturation transfer (GluCEST) value in the hippocampus of rat model exposed to chronic unpredictable mild stress (CUMS), and to explore the effect of this change on the activity of hippocampal glutamatergic neurons. STUDY TYPE: Prospective animal study. ANIMAL MODEL: Twenty male Sprague-Dawley rats (200-300 g). FIELD STRENGTH/SEQUENCE: 7.0 T scanner. Fat rapid acquisition relaxation enhancement sequence for GluCEST, and echo planner imaging sequence for resting-state functional magnetic resonance imaging (rs_fMRI). ASSESSMENT: Rats were divided into two groups: CUMS group (N = 10) and control group (CTRL, N = 10). The magnetization transfer ratio asymmetry analysis was used to quantify the GluCEST data, and evaluate the rs_fMRI data through the amplitude of low-frequency fluctuation (ALFF) and regional homogeneity (ReHo) analysis. STATISTICAL TESTS: A t-test was used to compare the difference in GluCEST or rs_fMRI between CUMS and CTRL groups. Spearman's correlation was applied to explore the correlation between GluCEST values and abnormal fMRI values in hippocampus. Statistical significance was set at P < 0.05. RESULTS: The GluCEST value in the left hippocampus has changed significantly (3.3 ± 0.3 [CUMS] vs. 3.9 ± 0.4 [CTRL], P < 0.05). In addition, the GluCEST value was significantly positively correlated with the ALFF values (r = 0.5, P < 0. 05, df = 7) and negatively correlated with the ReHo values (r = -0.6, P < 0.05, df = 7). DATA CONCLUSION: GluCEST technique has the feasibility of mapping glutamate changes in rat depression. Glutamate neurotransmitters are important factors affecting the abnormal function of neural activity. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY: Stage 1.


Assuntos
Encéfalo , Ácido Glutâmico , Animais , Mapeamento Encefálico , Depressão/diagnóstico por imagem , Hipocampo/diagnóstico por imagem , Imageamento por Ressonância Magnética , Masculino , Projetos Piloto , Estudos Prospectivos , Ratos , Ratos Sprague-Dawley
12.
BMC Musculoskelet Disord ; 22(1): 77, 2021 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-33441130

RESUMO

BACKGROUND: Intervertebral disc degeneration (IVDD) is a primary cause of degenerative disc diseases; however, the mechanisms underlying the degeneration remain unclear. The immunoinflammatory response plays an important role in IVDD progression. The inflammatory cytokine lymphotoxin-α (LTα), formerly known as TNFß, is associated with various pathological conditions, while its role in the pathogenesis of IVDD remains elusive. METHODS: Real-time quantitative polymerase chain reaction (RT-qPCR), Western blotting (WB), and enzyme-linked immunosorbent assays were used to assess the levels of LTα in human nucleus pulposus (NP) tissues between degeneration and control groups. The plasma concentrations of LTα and C-reactive protein (CRP) were compared between healthy and IVDD patients. Rat primary NP cells were cultured and identified via immunofluorescence. Methyl-thiazolyl-tetrazolium assays and flow cytometry were used to evaluate the effects of LTα on rat NP cell viability. After NP cells were treated with LTα, degeneration-related molecules (Caspase-3, Caspase-1, matrix metalloproteinase (MMP) -3, aggrecan and type II collagen) were measured via RT-qPCR and WB. RESULTS: The levels of both the mRNA and protein of LTα in human degenerated NP tissue significantly increased. Plasma LTα and CRP did not differ between healthy controls and IVDD patients. Rat primary NP cells were cultured, and the purity of primary NP cells was > 90%. Cell experiments showed inversely proportional relationships among the LTα dose, treatment time, and cell viability. The optimal conditions (dose and time) for LTα treatment to induce rat NP cell degeneration were 5 µg/ml and 48 ~ 72 h. The apoptosis rate and the levels of Caspase-3, Caspase-1, and MMP-3 significantly increased after LTα treatment, while the levels of type II collagen and aggrecan were decreased, and the protein expression levels were consistent with their mRNA expression levels. CONCLUSIONS: This study demonstrated that elevated LTα is closely associated with IVDD and that LTα may induce NP cell apoptosis and reduce important extracellular matrix (ECM) proteins, which cause adverse effects on IVDD progress. Moreover, the optimal conditions for LTα treatment to induce NP cell degeneration were determined.


Assuntos
Degeneração do Disco Intervertebral , Disco Intervertebral , Núcleo Pulposo , Agrecanas/genética , Animais , Colágeno Tipo II , Humanos , Linfotoxina-alfa , Ratos
13.
BMC Plant Biol ; 20(1): 15, 2020 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-31914920

RESUMO

BACKGROUND: Alfalfa is a high-quality forage cultivated widely in northern China. Recently, the failure of alfalfa plants to survive the winter has caused substantial economic losses. Water management has attracted considerable attention as a method for the potential improvement of winter survival. The aim of this study was to determine whether and how changes in the water regime affect the freezing tolerance of alfalfa. RESULTS: The alfalfa variety WL353LH was cultivated under water regimes of 80 and 25% of water-holding capacity, and all the plants were subjected to low temperatures at 4/0 °C (light/dark) and then - 2/- 6 °C (light/dark). The semi-lethal temperatures were lower for water-stressed than well-watered alfalfa. The pool sizes of total soluble sugars, total amino acids, and proline changed substantially under water-deficit and low-temperature conditions. Metabolomics analyses revealed 72 subclasses of differential metabolites, among which lipid and lipid-like molecules (e.g., fatty acids, unsaturated fatty acids, and glycerophospholipids) and amino acids, peptides, and analogues (e.g., proline betaine) were upregulated under water-deficit conditions. Some carbohydrates (e.g., D-maltose and raffinose) and flavonoids were also upregulated at low temperatures. Finally, Kyoto Encyclopedia of Genes and Genomes analyses revealed 18 significantly enriched pathways involved in the biosynthesis and metabolism of carbohydrates, unsaturated fatty acids, amino acids, and glycerophospholipids. CONCLUSIONS: Water deficit significantly enhanced the alfalfa' freezing tolerance, and this was correlated with increased soluble sugar, amino acid, and lipid and lipid-like molecule contents. These substances are involved in osmotic regulation, cryoprotection, and the synthesis, fluidity, and stability of the cellular membrane. Our study provides a reference for improving alfalfa' winter survival through water management.


Assuntos
Resposta ao Choque Frio/fisiologia , Medicago sativa/metabolismo , Metabolômica , Água/metabolismo , Aminoácidos/metabolismo , Metabolismo dos Carboidratos/genética , China , Temperatura Baixa , Congelamento , Perfilação da Expressão Gênica , Metabolismo dos Lipídeos/genética , Medicago sativa/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Estresse Fisiológico/fisiologia
14.
Nanotechnology ; 31(29): 295401, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32203950

RESUMO

The design of highly active, Earth-abundant and stable electrocatalysts is important for efficient water splitting. In this work, we report the fabrication of RuP and Ru2P nanoparticles supported on ordered macroporous N-doped carbon hollow spheres (RuP/H-NC and Ru2P/H-NC) through a facile and scalable space-confined pyrolysis process. The RuP/H-NC catalyst exhibits Pt-like activity in alkaline electrolyte, by means of the macroporous structure with a larger specific area and more exposed active sites, as well as the synergistic effect between the RuP nanoparticles and N-doped carbon. Specifically, the RuP/H-NC catalyst yields superior hydrogen evolution reaction activity in terms of low overpotential of 19 mV in 1 M KOH to achieve a current density of 10 mA cm-2 and excellent durability, outperforming Ru2P/H-NC and most of the reported non-Pt catalysts. Further density function theory calculation reveals that RuP is more intrinsically active with favorable hydrogen adsorption Gibbs free energy than that of Ru2P.

15.
BMC Health Serv Res ; 20(1): 430, 2020 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-32423447

RESUMO

BACKGROUND: To tackle the issue with the low usage of primary healthcare service in China, it is essential to align resource distribution with the preferences of the community residents. There are few academic researches for describing residents' perceived characteristics of healthcare services in China. This study aims to investigate the preferences of healthcare services utilization in community residents and explore the heterogeneity. The findings will be useful for the policy makers to take targeted measures to tailor the provision of healthcare services. METHODS: The face-to-face interviews and surveys were conducted to elicit four key attributes (care provider; mode of services; cost; travel time) of the preference from community residents for healthcare utilization. A rational test was presented first to confirm the consistency, and then 16 pairs of choice tasks with 12 sociodemographic items were given to the respondents. Two hypothetical options for each set, without an opt-out option, were presented in each choice task. The latent class analysis (LCA) was used to analyse the data. RESULTS: Two thousand one hundred sixty respondents from 36 communities in 6 cities were recruited for our study. 2019 (93.47%) respondents completed valid discrete choice experiment (DCE) questionnaires. The LCA results suggested that four groups of similar preferences were identified. The first group (27.29%) labelled as "Comprehensive consideration" had an even preference of all four attributes. The second group (37.79%) labelled as "Price-driven" preferred low-price healthcare services. The third group labelled as "Near distance" showed a clear preference for seeking healthcare services nearby. The fourth group (34.18%) labelled as "Quality seeker" preferred the healthcare service provided by experts. Willingness to pay (WTP) results showed that people were willing to accept CNY202.12($29.37) for Traditional Chinese Medicine (TCM) services and willing to pay CNY604.31($87.81) for the service provided by experts. CONCLUSIONS: Our study qualitatively measures the distinct preferences for healthcare utilization in community residents in China. The results suggest that the care provider, mode of services, travel time and cost should be considered in priority setting decisions. The study, however, reveals substantial disagreement in opinion of TCM between different population subgroups.


Assuntos
Aceitação pelo Paciente de Cuidados de Saúde/estatística & dados numéricos , Preferência do Paciente/estatística & dados numéricos , Adolescente , Adulto , China , Comportamento de Escolha , Feminino , Pesquisas sobre Atenção à Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Pesquisa Qualitativa , Adulto Jovem
16.
J Cell Biochem ; 120(11): 18894-18900, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31297885

RESUMO

Nuclear factor-κB (NF-κB) is an important regulatory factor in cells. NF-κB has a wide range of biological activities. After activation, it participates in the transcription and regulation of many genes and plays a role in infection, inflammatory response, oxidative stress, cell multiplication, and apoptosis. The activation of the NF-κB signal pathway is dependent on the degradation of the IκB kinase ß (IKKß) complex. IKK ß is the key kinase in the NF-κB activation pathway. After inhibition, it can block the activation of NF-κB. IKKß is a key regulator of NF-κB activation, also an early regulator of inflammation in all stages of the immune response. This study aimed to investigate the effect of IKKß-siRNA lentivirus vector treatment for hepatic fibrosis of rats. An IKKß-siRNA expression plasmid was constructed and injected in the tail vein of rats. Then, IKKß-siRNA distribution in the liver was observed by immunofluorescence, and the quantitative polymerase chain reaction was used to detect inflammation-related and fibrosis-related factors. IKKß-siRNA lentiviruses could be delivered to the liver and significantly decrease carbon tetrachloride-induced hepatic fibrosis. Furthermore, serum transaminase levels significantly decreased, and inflammation-related and fibrosis-related factors decreased. IKKß-siRNA can be an effective method of anti-fibrosis gene therapy for liver fibrosis.


Assuntos
Quinase I-kappa B , Cirrose Hepática , Interferência de RNA , Transdução de Sinais , Animais , Intoxicação por Tetracloreto de Carbono/genética , Intoxicação por Tetracloreto de Carbono/metabolismo , Intoxicação por Tetracloreto de Carbono/patologia , Intoxicação por Tetracloreto de Carbono/prevenção & controle , Vetores Genéticos , Quinase I-kappa B/antagonistas & inibidores , Quinase I-kappa B/genética , Quinase I-kappa B/metabolismo , Lentivirus , Cirrose Hepática/genética , Cirrose Hepática/metabolismo , Cirrose Hepática/patologia , Cirrose Hepática/prevenção & controle , Masculino , RNA Interferente Pequeno/biossíntese , RNA Interferente Pequeno/genética , Ratos , Ratos Sprague-Dawley , Transdução Genética
17.
J Fluoresc ; 29(3): 727-735, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31104269

RESUMO

A new biscarbazole-fused xanthene hybrid dye MeBCX has been prepared by CH3SO3H-promoted condensation of 4-hydroxycarbazole and o-phthalic anhydride, followed by esterification with methanol, which exhibits good cell membrane permeability. Taking advantage of the spiro-controlled xanthene platform of the dye, a Cu2+-selective fluorescence "off-on" probe BCX-Cu has been successfully prepared with excellent performances in selectivity and sensitivity, and the detection limit is calculated to be 88.7 nM. The sensing mechanism is confirmed to involve a specific cascade reactions of Cu2+-induced spirolactam ring-opening and hydrolysis. In addition, living L929 cell imaging demonstrates the probe has living cell membrane permeability and shows great potential for tracing intracellular Cu2+ through fluorescence imaging technology.


Assuntos
Carbazóis/química , Cobre/análise , Cobre/química , Corantes Fluorescentes/química , Limite de Detecção , Imagem Óptica/métodos , Xantenos/química , Linhagem Celular , Sobrevivência Celular , Espectrometria de Fluorescência
18.
Plant Mol Biol ; 96(4-5): 473-492, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29532290

RESUMO

KEY MESSAGE: The induction of miR399 and miR398 and the inhibition of miR156, miR159, miR160, miR171, miR2111, and miR2643 were observed under Pi deficiency in alfalfa. The miRNA-mediated genes involved in basic metabolic process, root and shoot development, stress response and Pi uptake. Inorganic phosphate (Pi) deficiency is known to be a limiting factor in plant development and growth. However, the underlying miRNAs associated with the Pi deficiency-responsive mechanism in alfalfa are unclear. To elucidate the molecular mechanism at the miRNA level, we constructed four small RNA (sRNA) libraries from the roots and shoots of alfalfa grown under normal or Pi-deficient conditions. In the present study, alfalfa plants showed reductions in biomass, photosynthesis, and Pi content and increases in their root-to-shoot ratio and citric, malic, and succinic acid contents under Pi limitation. Sequencing results identified 47 and 44 differentially expressed miRNAs in the roots and shoots, respectively. Furthermore, 909 potential target genes were predicted, and some targets were validated by RLM-RACE assays. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses showed prominent enrichment in signal transducer activity, binding and basic metabolic pathways for carbohydrates, fatty acids and amino acids; cellular response to hormone stimulus and response to auxin pathways were also enriched. qPCR results verified that the differentially expressed miRNA profile was consistent with sequencing results, and putative target genes exhibited opposite expression patterns. In this study, the miRNAs associated with the response to Pi limitation in alfalfa were identified. In addition, there was an enrichment of miRNA-targeted genes involved in biological regulatory processes such as basic metabolic pathways, root and shoot development, stress response, Pi transportation and citric acid secretion.


Assuntos
Medicago sativa/genética , Medicago sativa/fisiologia , MicroRNAs/genética , Fosfatos/deficiência , Sequência de Bases , Sequência Conservada/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Ontologia Genética , Sequenciamento de Nucleotídeos em Larga Escala , MicroRNAs/metabolismo , Modelos Biológicos , Raízes de Plantas/genética , Brotos de Planta/genética , RNA de Plantas/genética , RNA de Plantas/metabolismo , Reprodutibilidade dos Testes
19.
Small ; 14(20): e1800395, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29665266

RESUMO

A 3D fluorine-doped SnO2 (FTO)/FTO-nanocrystal (NC)/TiO2 inverse opal (IO) structure is designed and fabricated as a new "host and guest" type of composite photoanode for efficient photoelectrochemical (PEC) water splitting. In this novel photoanode design, the highly conductive and porous FTO/FTO-NC IO acts as the "host" skeleton, which provides direct pathways for faster electron transport, while the conformally coated TiO2 layer acts as the "guest" absorber layer. The unique composite IO structure is fabricated through self-assembly of colloidal spheres template, a hydrothermal method and atomic layer deposition (ALD). Owing to its large surface area and efficient charge collection, the FTO/FTO-NC/TiO2 composite IO photoanode shows excellent photocatalytic properties for PEC water splitting. With optimized dimensions of the SnO2 nanocrystals and the thickness of the ALD TiO2 absorber layers, the 3D FTO/FTO-NC/TiO2 composite IO photoanode yields a photocurrent density of 1.0 mA cm-2 at 1.23 V versus reversible hydrogen electrode (RHE) under AM 1.5 illumination, which is four times higher than that of the FTO/TiO2 IO reference photoanode.

20.
Exp Brain Res ; 236(3): 907-918, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29362830

RESUMO

Humans can skillfully recognize actions from others' body motion and make a judgment or response at once. Previous neuroimaging studies have mostly utilized diminished and brief human motion stimuli and indicated that human occipito-temporal cortex plays a critical role at biological motion recognition. It remains unclear to what extent that the areas related to human motion perception are involved in decoding basic movements. Because human movement naturally stems from the sequences of body posture, so we utilized the stimulus of real movements. Participants were presented four categories of human movements (jump, run, skip and walk) in a blocked fMRI experiment. Multi-voxel pattern analysis (MVPA) was adopted to assess whether different movements could be discriminated in four regions. We found that movement-specific information was represented in both human body-sensitive areas, extrastriate body area (EBA) and motion-sensitive areas, posterior superior temporal sulcus (pSTS) and human middle temporal complex (hMT+). Additionally, a further functional connectivity analysis using EBA as a seed was conducted and it suggested that EBA showed a task-modulated functional connectivity with multiple areas that were involved in the behavior perception and motor control. Human motion processing appeared to be completed in a distributed network. The occipito-temporal cortex may perform the initial processing of human motion information extracting, and then transform them to interconnected areas for a further utilization.


Assuntos
Mapeamento Encefálico/métodos , Córtex Cerebral/fisiologia , Processamento de Imagem Assistida por Computador/métodos , Percepção de Movimento/fisiologia , Reconhecimento Automatizado de Padrão/métodos , Percepção Social , Adulto , Córtex Cerebral/diagnóstico por imagem , Conectoma/métodos , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Adulto Jovem
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