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1.
Molecules ; 28(11)2023 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-37298996

RESUMO

ZnIn2S4 (ZIS) is widely used in the field of photocatalytic hydrogen production due to its unique photoelectric properties. Nonetheless, the photocatalytic performance of ZIS usually faces problems of poor conductivity and rapid recombination of charge carriers. Heteroatom doping is often regarded as one of the effective strategies for improving the catalytic activity of photocatalysts. Herein, phosphorus (P)-doped ZIS was prepared by hydrothermal method, whose photocatalytic hydrogen production performance and energy band structure were fully studied. The band gap of P-doped ZIS is about 2.51 eV, which is slightly smaller than that of pure ZIS. Moreover, due to the upward shift of its energy band, the reduction ability of P-doped ZIS is enhanced, and P-doped ZIS also exhibits stronger catalytic activity than pure ZIS. The optimized P-doped ZIS exhibits a hydrogen production rate of 1566.6 µmol g-1 h-1, which is 3.8 times that of the pristine ZIS (411.1 µmol g-1 h-1). This work provides a broad platform for the design and synthesis of phosphorus-doped sulfide-based photocatalysts for hydrogen evolution.


Assuntos
Hidrogênio , Luz , Condutividade Elétrica , Fósforo
2.
Proc Natl Acad Sci U S A ; 116(50): 25243-25249, 2019 12 10.
Artigo em Inglês | MEDLINE | ID: mdl-31754041

RESUMO

Cardiovascular risk factors such as dyslipidemia and hypertension increase the risk for white matter pathology and cognitive decline. We hypothesize that white matter levels of N-acetylaspartate (NAA), a chemical involved in the metabolic pathway for myelin lipid synthesis, could serve as a biomarker that tracks the influence of cardiovascular risk factors on white matter prior to emergence of clinical changes. To test this, we measured levels of NAA across white matter and gray matter in the brain using echo planar spectroscopic imaging (EPSI) in 163 individuals and examined the relationship of regional NAA levels and cardiovascular risk factors as indexed by the Framingham Cardiovascular Risk Score (FCVRS). NAA was strongly and negatively correlated with FCVRS across the brain, but, after accounting for age and sex, the association was found primarily in white matter regions, with additional effects found in the thalamus, hippocampus, and cingulate gyrus. FCVRS was also negatively correlated with creatine levels, again primarily in white matter. The results suggest that cardiovascular risks are related to neurochemistry with a predominantly white matter pattern and some subcortical and cortical gray matter involvement. NAA mapping of the brain may provide early surveillance for the potential subclinical impact of cardiovascular and metabolic risk factors on the brain.


Assuntos
Ácido Aspártico/análogos & derivados , Doenças Cardiovasculares/diagnóstico , Substância Cinzenta/metabolismo , Substância Branca/metabolismo , Adulto , Ácido Aspártico/análise , Ácido Aspártico/metabolismo , Pressão Sanguínea , Doenças Cardiovasculares/metabolismo , Doenças Cardiovasculares/fisiopatologia , Imagem Ecoplanar , Feminino , Substância Cinzenta/química , Substância Cinzenta/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Substância Branca/química , Substância Branca/diagnóstico por imagem , Adulto Jovem
3.
J Magn Reson Imaging ; 49(1): 176-183, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-29659065

RESUMO

BACKGROUND: Cerebral glutathione (GSH), a marker of oxidative stress, has been quantified in neurodegenerative diseases and psychiatric disorders using proton magnetic resonance spectroscopy (MRS). Using a reproducible MRS technique is important, as it minimizes the impact of measurement technique variability on the study results and ensures that other studies can replicate the results. HYPOTHESIS: We hypothesized that very short echo time (TE) acquisitions would have comparable reproducibility to a long TE MEGA-PRESS acquisition, and that the short TE PRESS acquisition would have the poorest reproducibility. STUDY TYPE: Prospective. SUBJECTS/PHANTOMS: Ten healthy adults were scanned during two visits, and six metabolite phantoms containing varying concentrations of GSH and metabolites with resonances that overlap with GSH were scanned once. FIELD STRENGTH/SEQUENCE: At 3T we acquired MRS data using four different sequences: PRESS, SPECIAL, PR-STEAM, and MEGA-PRESS. ASSESSMENT: Reproducibility of each MRS sequence across two visits was assessed. STATISTICAL TESTS: Mean coefficients of variation (CV) and mean absolute difference (AD) were used to assess reproducibility. Linear regressions were performed on data collected from phantoms to examine the agreement between known and quantified levels of GSH. RESULTS: Of the four techniques, PR-STEAM had the lowest mean CV and AD (5.4% and 7.5%, respectively), implying excellent reproducibility, followed closely by PRESS (5.8% and 8.2%) and SPECIAL (8.0 and 10.1%), and finally by MEGA-PRESS (13.5% and 17.1%). Phantom data revealed excellent fits (R2 ≥ 0.98 or higher) using all methods. DATA CONCLUSION: Our data suggest that GSH can be quantified reproducibly without the use of spectral editing. LEVEL OF EVIDENCE: 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;49:176-183.


Assuntos
Encéfalo/diagnóstico por imagem , Glutationa/análise , Estresse Oxidativo , Espectroscopia de Prótons por Ressonância Magnética , Adulto , Feminino , Voluntários Saudáveis , Humanos , Modelos Lineares , Masculino , Imagens de Fantasmas , Estudos Prospectivos , Reprodutibilidade dos Testes , Adulto Jovem
4.
NMR Biomed ; 31(6): e3914, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29727496

RESUMO

Accurate measurement of brain metabolite concentrations with proton magnetic resonance spectroscopy (1 H-MRS) can be problematic because of large voxels with mixed tissue composition, requiring adjustment for differing relaxation rates in each tissue if absolute concentration estimates are desired. Adjusting for tissue-specific metabolite signal relaxation, however, also requires a knowledge of the relative concentrations of the metabolite in gray (GM) and white (WM) matter, which are not known a priori. Expressions for the estimation of the molality and molarity of brain metabolites with 1 H-MRS are extended to account for tissue-specific relaxation of the metabolite signals and examined under different assumptions with simulated and real data. Although the modified equations have two unknowns, and hence are unsolvable explicitly, they are nonetheless useful for the estimation of the effect of tissue-specific metabolite relaxation rates on concentration estimates under a range of assumptions and experimental parameters using simulated and real data. In simulated data using reported GM and WM T1 and T2 times for N-acetylaspartate (NAA) at 3 T and a hypothetical GM/WM NAA ratio, errors of 6.5-7.8% in concentrations resulted when TR = 1.5 s and TE = 0.144 s, but were reduced to less than 0.5% when TR = 6 s and TE = 0.006 s. In real data obtained at TR/TE = 1.5 s/0.04 s, the difference in the results (4%) was similar to that obtained with simulated data when assuming tissue-specific relaxation times rather than GM-WM-averaged times. Using the expressions introduced in this article, these results can be extrapolated to any metabolite or set of assumptions regarding tissue-specific relaxation. Furthermore, although serving to bound the problem, this work underscores the challenge of correcting for relaxation effects, given that relaxation times are generally not known and impractical to measure in most studies. To minimize such effects, the data should be acquired with pulse sequence parameters that minimize the effect of signal relaxation.


Assuntos
Encéfalo/metabolismo , Metaboloma , Espectroscopia de Prótons por Ressonância Magnética , Processamento de Sinais Assistido por Computador , Ácido Aspártico/análogos & derivados , Ácido Aspártico/metabolismo , Substância Cinzenta/metabolismo , Humanos , Especificidade de Órgãos , Substância Branca/metabolismo
5.
JMIR Serious Games ; 12: e46789, 2024 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-38596827

RESUMO

Background: Removable partial denture (RPD) design is crucial to long-term success in dental treatment, but shortcomings in RPD design training and competency acquisition among dental students have persisted for decades. Digital production is increasing in prevalence in stomatology, and a digital RPD (D-RPD) module, under the framework of the certified Objective Manipulative Skill Examination of Dental Technicians (OMEDT) system reported in our previous work, may improve on existing RPD training models for students. Objective: We aimed to determine the efficacy of a virtual 3D simulation-based progressive digital training module for RPD design compared to traditional training. Methods: We developed a prospective cohort study including dental technology students at the Stomatology College of Chongqing Medical University. Cohort 1 received traditional RPD design training (7 wk). Cohort 2 received D-RPD module training based on text and 2D sketches (7 wk). Cohort 3 received D-RPD module pilot training based on text and 2D sketches (4 wk) and continued to receive training based on 3D virtual casts of real patients (3 wk). RPD design tests based on virtual casts were conducted at 1 month and 1 year after training. We collected RPD design scores and the time spent to perform each assessment. Results: We collected the RPD design scores and the time spent to perform each assessment at 1 month and 1 year after training. The study recruited 109 students, including 58 (53.2%) female and 51 male (56.8%) students. Cohort 1 scored the lowest and cohort 3 scored the highest in both tests (cohorts 1-3 at 1 mo: mean score 65.8, SD 21.5; mean score 81.9, SD 6.88; and mean score 85.3, SD 8.55, respectively; P<.001; cohorts 1-3 at 1 y: mean score 60.3, SD 16.7; mean score 75.5, SD 3.90; and mean score 90.9, SD 4.3, respectively; P<.001). The difference between cohorts in the time spent was not statistically significant at 1 month (cohorts 1-3: mean 2407.8, SD 1370.3 s; mean 1835.0, SD 1329.2 s; and mean 1790.3, SD 1195.5 s, respectively; P=.06) but was statistically significant at 1 year (cohorts 1-3: mean 2049.16, SD 1099.0 s; mean 1857.33, SD 587.39 s; and mean 2524.3, SD 566.37 s, respectively; P<.001). Intracohort comparisons indicated that the differences in scores at 1 month and 1 year were not statistically significant for cohort 1 (95% CI -2.1 to 13.0; P=.16), while cohort 3 obtained significantly higher scores 1 year later (95% CI 2.5-8.7; P=.001), and cohort 2 obtained significantly lower scores 1 year later (95% CI -8.8 to -3.9; P<.001). Conclusions: Cohort 3 obtained the highest score at both time points with retention of competency at 1 year, indicating that progressive D-RPD training including virtual 3D simulation facilitated improved competency in RPD design. The adoption of D-RPD training may benefit learning outcomes.

6.
Acta Crystallogr Sect E Struct Rep Online ; 69(Pt 5): m294-5, 2013 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-23723790

RESUMO

In the title compound, [Eu2(C6H5NO3)2(C2O4)3(H2O)4] n , the Eu(III) atom is bonded to one O atom from a monodentate 5-hy-droxy-pyridin-1-ium-3-carboxyl-ate ligand, six O atoms from three oxalate ligands and two water mol-ecules, exhibiting a highly distorted tricapped trigonal geometry. Three independent oxalate ligands, each lying on an inversion center, bridge the Eu(III) atoms, forming a brickwall-like layer parallel to (001), which is stabilized by intra-layer O-H⋯O hydrogen bonds. The layers are further linked through inter-layer O-H⋯O and N-H⋯O hydrogen bonds and π-π inter-actions between the pyridine rings [centroid-centroid distance = 3.5741 (14) Å] into a three-dimensional supra-molecular network.

7.
Nat Commun ; 14(1): 6736, 2023 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-37872169

RESUMO

Neuro-inspired vision systems hold great promise to address the growing demands of mass data processing for edge computing, a distributed framework that brings computation and data storage closer to the sources of data. In addition to the capability of static image sensing and processing, the hardware implementation of a neuro-inspired vision system also requires the fulfilment of detecting and recognizing moving targets. Here, we demonstrated a neuro-inspired optical sensor based on two-dimensional NbS2/MoS2 hybrid films, which featured remarkable photo-induced conductance plasticity and low electrical energy consumption. A neuro-inspired optical sensor array with 10 × 10 NbS2/MoS2 phototransistors enabled highly integrated functions of sensing, memory, and contrast enhancement capabilities for static images, which benefits convolutional neural network (CNN) with a high image recognition accuracy. More importantly, in-sensor trajectory registration of moving light spots was experimentally implemented such that the post-processing could yield a high restoration accuracy. Our neuro-inspired optical sensor array could provide a fascinating platform for the implementation of high-performance artificial vision systems.

8.
Psychiatry Res ; 201(3): 253-5, 2012 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-22541511

RESUMO

The resting state amplitude of low frequency fluctuations (ALFF) in functional magnetic resonance imaging has been shown to be reliable in healthy subjects, and to correlate with antipsychotic treatment response in antipsychotic-naïve schizophrenia patients. We found moderate to high test-retest stability of ALFF in chronically treated schizophrenia patients assessed twice over a median interval of 2.5 months.


Assuntos
Encéfalo/irrigação sanguínea , Imageamento por Ressonância Magnética , Descanso/fisiologia , Esquizofrenia/patologia , Adulto , Encéfalo/patologia , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Oxigênio/sangue , Escalas de Graduação Psiquiátrica , Reprodutibilidade dos Testes , Esquizofrenia/fisiopatologia , Adulto Jovem
9.
Acta Crystallogr Sect E Struct Rep Online ; 68(Pt 9): m1146-7, 2012 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-22969449

RESUMO

In the title compound, {[Ho(2)(C(6)H(4)NO(3))(2)(C(2)O(4))(2)(H(2)O)(2)]·2H(2)O}(n), the Ho(III) atom is coordinated by three O atoms from three 5-hy-droxy-nicotinate ligands, four O atoms from two oxalate ligands, each lying on an inversion center, and one water mol-ecule in a distorted square-anti-prismatic geometry. The 5-hy-droxy-nicotinate ligand is protonated at the N atom and deprotonated at the hy-droxy group. The Ho(III) atoms are bridged by the carboxyl-ate and phenolate O atoms, forming a three-dimensional framework. N-H⋯O and O-H⋯O hydrogen bonds, as well as π-π inter-actions between the pyridine rings [centroid-centroid distance = 3.794 (2) Å], are observed.

10.
Artigo em Inglês | MEDLINE | ID: mdl-35627384

RESUMO

Mixed land use provides an important means of promoting the intensive and efficient use of land resources and stimulating endogenous development power in rural areas. This paper selected Pingba Village in Chongqing as the research area; the land use status data and the social and economic data on rural settlements in the study area for 2021 were obtained through field visits and interviews. Moreover, the land use types in the rural settlements were subdivided according to the principle of dominant function. Based on these subdivisions, a land mixed-use measurement system for rural settlements was constructed to analyze their levels of mixed land use. Furthermore, the influences of natural environmental, social, economic and other factors on mixed land use were comprehensively explored. The results showed that, (1) the mixed land use of rural settlements in the study area was at a medium level and showed significant spatial variability, and rural settlements in the high, medium and low mixed land use index zones accounted for 12.5%, 35% and 52.5% of the total, respectively. (2) The differences in the natural environment determined the level of mixed land use and the basic pattern of its spatial differentiation. Social and economic factors, such as resident population and average household income, were key impact factors. Rural tourism resources, homestead agglomeration policies and other factors had important impacts on the level of mixed land use. In conclusion, the research suggests that mixed land use is an important way to boost rural revitalization. In the future, village planning could introduce the concept of mixed land use to improve the efficiency of land use, optimize the land use structure according to local conditions and promote the integrated development of rural primary, secondary and tertiary industries. In addition, it is necessary to scientifically and rationally guide rural settlements to agglomerate appropriately to improve the utilization efficiency of land resources and public service resources.


Assuntos
Indústrias , População Rural , China , Meio Ambiente , Humanos , Turismo
11.
Nanoscale Adv ; 4(24): 5290-5296, 2022 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-36540126

RESUMO

Mixed-dimensional van der Waals (vdW) integration has been demonstrated to be effective for the modulation of the physical properties of homogeneous materials. Herein, we reported the enhancement of photothermal conversion and decrease of thermal conductivity in metallic single-walled carbon nanotube (SWCNT) films with the integration of chemical vapor deposition-grown monolayer MoS2 films. The induced temperature gradient in SWCNT-MoS2 hybrid films drives carrier diffusion to generate photocurrent via the photothermoelectric (PTE) effect, and a self-powered photodetector working in the visible band range from 405 to 785 nm was demonstrated. The maximum responsivity of the device increases by 6 times compared to that of the SWCNT counterpart. More importantly, the mixed-dimensional device exhibits polarization-dependent photogeneration, showing a large anisotropy ratio of 1.55. This work paves a way for developing high-performance, polarization-sensitive photodetectors by mixed-dimensional integration.

12.
Magn Reson Med ; 66(2): 324-32, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21360748

RESUMO

A 1H magnetic resonance spectroscopic imaging study at 3T and short echo time was conducted to evaluate both the reproducibility, as measured by the interscan coefficient of variation (CV), and test-retest reliability, as measured by the intraclass correlation coefficient (ICC), of measurements of glutamate (Glu), combined glutamate and glutamine (Glx), myo-inositol (mI), N-acetylaspartate, creatine, and choline in 21 healthy subjects. The effect of partial volume correction on these measures and the relationship of reproducibility and reliability to data quality were also examined. A 1H magnetic resonance spectroscopic imaging slice was prescribed above the lateral ventricles and single repeat scans were performed within 30 min to minimize physiologic variability. Interscan CVs based on all the voxels varied from 0.05 to 0.07 for N-acetylaspartate, creatine, and choline to 0.10-0.13 for mI, Glu, and Glx. Findings on the reproducibility of gray and white matter estimates of N-acetylaspartate, creatine, and choline are consistent with previous studies using longer echo times, with CVs in the range of 0.02-0.04 and ICC in the range of 0.65-0.90. CVs for Glu, Glx, and mI are much lower than reported in previous studies at 1.5 T, while white matter mI (CV=0.04, ICC=0.93) and gray matter Glx (CV=0.04, ICC=0.68) demonstrated both high reproducibility and test-retest reliability.


Assuntos
Encéfalo/metabolismo , Imageamento por Ressonância Magnética/métodos , Espectroscopia de Ressonância Magnética/métodos , Neurotransmissores/análise , Humanos , Masculino , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Adulto Jovem
13.
Acta Crystallogr Sect E Struct Rep Online ; 67(Pt 7): m974, 2011 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-21836949

RESUMO

In the title compound, [Nd(2)(C(6)H(3)BrNO(2))(6)(H(2)O)(4)]·2H(2)O, the Nd(III) ion is coordinated by nine O atoms from one chelating 5-bromo-nicotinate ligand, four bridging 5-bromo-nicotinate ligands and two water mol-ecules, exhibiting a distorted three-capped triangular-prismatic geometry. Two Nd(III) ions are bridged by four carboxyl-ate groups in bi- and tridentate modes, forming a centrosymmetric dinuclear unit, with an Nd⋯Nd distance of 4.0021 (5) Å, and intra-molecular π-π inter-actions between the pyridine rings [centroid-centroid distance = 3.960 (2) Å]. Inter-molecular π-π inter-actions [centroid-centroid distances = 3.820 (2) and 3.804 (2) Å] and O-H⋯N and O-H⋯O hydrogen bonds connect the dinuclear mol-ecules into a three-dimensional supra-molecular network.

14.
Front Psychiatry ; 12: 644271, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33868055

RESUMO

Schizophrenia is a severe mental illness with visual learning and memory deficits, and reduced long term potentiation (LTP) may underlie these impairments. Recent human fMRI and EEG studies have assessed visual plasticity that was induced with high frequency visual stimulation, which is thought to mimic an LTP-like phenomenon. This study investigated the differences in visual plasticity in participants with schizophrenia and healthy controls. An fMRI visual plasticity paradigm was implemented, and proton magnetic resonance spectroscopy data were acquired to determine whether baseline resting levels of glutamatergic and GABA metabolites were related to visual plasticity response. Adults with schizophrenia did not demonstrate visual plasticity after family-wise error correction; whereas, the healthy control group did. There was a significant regional difference in visual plasticity in the left visual cortical area V2 when assessing group differences, and baseline GABA levels were associated with this specific ROI in the SZ group only. Overall, this study suggests that visual plasticity is altered in schizophrenia and related to basal GABA levels.

15.
Food Sci Nutr ; 8(7): 3234-3242, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32724588

RESUMO

The copigmentation effects of three phenolic acids (ferulic acid, sinapic acid, and syringic acid) on the color and thermal stability of Chinese bayberry anthocyanins were investigated. The three copigments of ferulic acid, sinapic acid, and syringic acid were found to have significant effects on the color enhancement of bayberry anthocyanins (p < .05). The maximum absorption wavelength of the anthocyanin aqueous solution exhibited a bathochromic shift, L* decreased, and a* increased with the increase in the molar ratio of copigments. The thermal stability of bayberry anthocyanins was significantly improved after copigmentation. No new anthocyanin derivatives appeared after copigmentation. The thermodynamic parameters (ΔG, ΔH, ΔS) of the three processes were all negative, indicating the three copigmentations were generally spontaneous and exothermic. The equilibrium constant (K) of the sinapic acid group was the greatest among the three phenolic acids, indicating that sinapic acid was more effective in stabilizing the anthocyanins.

16.
J Psychiatr Res ; 120: 14-20, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31610406

RESUMO

Up to 80% of patients with schizophrenia experience sleep disturbances, which negatively impact daytime functioning. Given that the glutamatergic system is involved in the pathophysiology of schizophrenia as well as normal sleep-wake neurobiology, the current project aimed to determine whether sleep quality was related to brain glutamate levels in schizophrenia. The Pittsburgh Sleep Quality Index (PSQI) was used to assess subjective sleep quality and proton magnetic resonance spectroscopy (MRS) was used to quantify glutamate in the bilateral anterior cingulate, left parietal cortex, and left hippocampus. Results indicate that global PSQI scores were negatively correlated with the anterior cingulate and parietal glutamate levels. In patients with schizophrenia, poorer sleep quality correlated with greater positive symptom severity. Our findings suggest that poor sleep quality is related to greater positive symptom severity and lower levels of anterior cingulate glutamate in individuals with schizophrenia. Interventions to enhance sleep quality may prove beneficial for patients. Future studies will examine whether glutamate relates to objective measures of sleep quality, and whether glutamate may mediate the relationship between sleep quality and symptom severity across the schizophrenia-spectrum.


Assuntos
Ácido Glutâmico/metabolismo , Giro do Cíngulo/metabolismo , Hipocampo/metabolismo , Lobo Parietal/metabolismo , Esquizofrenia , Transtornos do Sono-Vigília , Adulto , Feminino , Giro do Cíngulo/diagnóstico por imagem , Hipocampo/diagnóstico por imagem , Humanos , Espectroscopia de Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Lobo Parietal/diagnóstico por imagem , Esquizofrenia/complicações , Esquizofrenia/metabolismo , Esquizofrenia/fisiopatologia , Índice de Gravidade de Doença , Transtornos do Sono-Vigília/etiologia , Transtornos do Sono-Vigília/metabolismo , Transtornos do Sono-Vigília/fisiopatologia , Adulto Jovem
17.
J Phys Chem B ; 113(38): 12623-7, 2009 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-19719096

RESUMO

Nanoporous thin films fabricated by both a core-shell-shaped organic-inorganic hybrid sphere (octa(2,4-dinitrophenyl)silsesquioxane, ODNPSQ) and a four-leg-numbered surfactant (polyoxyethylene sorbitan monolaurate, Tween-20) for porogens in a higher molecular weight precursor (polyphenylsilsesquioxane, PPSQ) were characterized, respectively, by grazing incidence small-angle X-ray scattering (GISAXS), and the measured 2D GISAXS profiles were analyzed quantitatively by using a GISAXS formula based on the distorted wave Born approximation (DWBA). The fitted 2D GISAXS data show that the PPSQ porous thin films imprinted with ODNPSQ porogen exhibit sphere-shaped closed pores with the average pore size within a range of 1.18-3.12 nm and pore size distribution widths about 3.0 nm when the porogen loadings increase from 10 to 40 wt % and those imprinted with Tween-20 porogen give out an average pore size of 1.07-1.29 nm and pore size distribution widths about 2.0 nm with the porogen loading varying from 5 to 30 wt %. The nanoporous dielectric thin films imprinted with ODNPSQ porogen show a reducing to the molecular aggregation of porogens and significant antiphase separation behavior in the cross-linked matrix.


Assuntos
Membranas Artificiais , Nanoestruturas , Espalhamento a Baixo Ângulo , Silicatos/química , Porosidade , Propriedades de Superfície , Raios X
18.
Acta Crystallogr Sect E Struct Rep Online ; 65(Pt 10): m1262-3, 2009 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-21577774

RESUMO

The title coordination polymer, [Cu(C(6)H(3)BrNO(2))(2)](n), is composed of two structurally similar two-dimensional coordination polymers (twin layers). Both of them have the same chemical composition but they display different bond lengths and angles. In each layer, two N atoms and four carboxyl-ate O atoms from the bridging 5-bromo-nicotinate ligands and four carboxyl-ate O atoms from the terminal 5-bromo-nicotinate ligands bind to two Cu(II) atoms to form a dinuclear paddle-wheel-like pattern. Adjacent paddle wheels are further linked by bridging 5-bromo-nicotinate groups to generate a two-dimensional coordination polymer; neighboring twin-like layers are finally stacked through π-π stacking interactions between adjacent pyridine rings [perpendicular distance of 3.626 (2) Å] in a 'sandwich' manner, thus generating a three-dimensional supra-molecular structure.

19.
Biomed Pharmacother ; 118: 109313, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31545233

RESUMO

Bone marrow-derived mesenchymal stem cells (MSCs) from systemic lupus erythematosus patients (SLE-BMSCs) exhibited abnormalities in cytokine production and immune modulation. Deregulation of Nod-like receptor pyrin domain-containing protein 3 (NLRP3) inflammasome plays an important role in SLE. Herein, we explored whether miRNAs are involved in the regulation of NLRP3 in SLE-BMSCs. ELISA assay was used to detect the levels of inflammatory cytokines. The expression levels of let-7f-5p and gene mRNAs were determined by qRT-PCR assay. The protein levels of NLRP3, Cleaved caspase-1 and ASC were measured by western blot. The interaction between let-7f-5p and NLRP3 was verified using dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay. In vivo assay was performed to explore whether let-7f-5p upregulation could ameliorate inflammation in MRL/lpr mice. Our data indicated that SLE patients had significantly serum higher levels of IFN-γ, IL-6, IL-18, IL-12, IL-13 and IL-1ß. We demonstrated that NLRP3 expression was upregulated in SLE-BMSCs. Let-7f-5p directly targeted NLRP3 and repressed NLRP3 expression. NLRP3 depletion or let-7f-5p upregulation repressed IL-1ß production and the expression of NLRP3 inflammasome components. Moreover, upregulated let-7f-5p-mediated anti-inflammation effect was significantly abrogated by NLRP3 expression restoration. Besides, let-7f-5p upregulation ameliorated inflammation through modulating NLRP3 in vivo. In conclusion, our study suggested that high level of let-7f-5p alleviated inflammation in SLE-BMSCs at least partly through targeting NLRP3, highlighting let-7f-5p as a novel promising therapeutic strategy for SLE treatment.


Assuntos
Células da Medula Óssea/metabolismo , Inflamação/patologia , Lúpus Eritematoso Sistêmico/metabolismo , Lúpus Eritematoso Sistêmico/patologia , Células-Tronco Mesenquimais/metabolismo , MicroRNAs/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Animais , Sequência de Bases , Citocinas/sangue , Feminino , Humanos , Mediadores da Inflamação/sangue , Lúpus Eritematoso Sistêmico/sangue , Camundongos Endogâmicos MRL lpr , MicroRNAs/genética , Regulação para Cima
20.
Schizophr Bull ; 45(3): 647-658, 2019 04 25.
Artigo em Inglês | MEDLINE | ID: mdl-29912445

RESUMO

BACKGROUND: The underlying neurobiological mechanism for abnormal functional connectivity in schizophrenia (SCZ) remains unknown. This project investigated whether glutamate and GABA, 2 metabolites that contribute to excitatory and inhibitory functions, may influence functional connectivity in SCZ. METHODS: Resting-state functional magnetic resonance imaging and proton magnetic resonance spectroscopy were acquired from 58 SCZ patients and 61 healthy controls (HC). Seed-based connectivity maps were extracted between the anterior cingulate cortex (ACC) spectroscopic voxel and all other brain voxels. Magnetic resonance spectroscopy (MRS) spectra were processed to quantify glutamate and GABA levels. Regression analysis was performed to describe relationships between functional connectivity and glutamate and GABA levels. RESULTS: Reduced ACC functional connectivity in SCZ was found in regions associated with several neural networks including the default mode network (DMN) compared to HC. In the HC, positive correlations were found between glutamate and both ACC-right inferior frontal gyrus functional connectivity and ACC-bilateral superior temporal gyrus functional connectivity. A negative correlation between GABA and ACC-left posterior cingulate functional connectivity was also observed in HC. These same relationships were not statistically significant in SCZ. CONCLUSIONS: The present investigation is one of the first studies to examine links between functional connectivity and glutamate and GABA levels in SCZ. Results indicate that glutamate and GABA play an important role in the functional connectivity modulation in the healthy brain. The absence of glutamate and GABA correlations in areas where SCZ showed significantly reduced functional connectivity may suggest that this chemical-functional relationship is disrupted in SCZ.


Assuntos
Conectoma , Ácido Glutâmico/metabolismo , Giro do Cíngulo , Rede Nervosa , Córtex Pré-Frontal , Esquizofrenia , Lobo Temporal , Ácido gama-Aminobutírico/metabolismo , Adulto , Feminino , Giro do Cíngulo/diagnóstico por imagem , Giro do Cíngulo/metabolismo , Giro do Cíngulo/fisiopatologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Rede Nervosa/diagnóstico por imagem , Rede Nervosa/metabolismo , Rede Nervosa/fisiopatologia , Córtex Pré-Frontal/diagnóstico por imagem , Córtex Pré-Frontal/metabolismo , Córtex Pré-Frontal/fisiopatologia , Espectroscopia de Prótons por Ressonância Magnética , Esquizofrenia/diagnóstico por imagem , Esquizofrenia/metabolismo , Esquizofrenia/fisiopatologia , Lobo Temporal/diagnóstico por imagem , Lobo Temporal/metabolismo , Lobo Temporal/fisiopatologia , Adulto Jovem
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