Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.317
Filtrar
1.
Bioorg Chem ; 107: 104623, 2021 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-33444984

RESUMO

Three new alkaloids (1-3) together with four previously reported compounds (4-7) were identified from the extracts and the diversity-enhanced extracts of the fermentation broth of the endophytic fungus, Aspergillus flavus GZWMJZ-288 associated with Garcinia multiflora. The structures of new compounds were respectively determined as 19-amino-19-dehydroxy 5-epi-α-cyclopiazonic acid (1), 2-hydroxymethyl-5-(3-oxobutan-2-yl)aminopyran-4(4H)-one (2) and 4-amino-2-hydroxymethylpyridin-5-ol (3) by spectroscopic analysis, ECD calculation and X-ray single crystal diffraction. Compounds 1 and 4 with 19-enamine were dynamic equilibrium of Z- and E- isomers in the solution but favored in Z- isomers in the solid state, while compound 7 with 19-enol was favored in Z- isomer in the solution but a mixture of Z- and E- isomers in solid state. This phenomenon could be explained by the quantum-mechanical energies calculations. Among the isolated compounds 1-7, compounds 1, 4 and 7 with a rare 1,3,4,5-tetrahydro-1-azaacenaphtho[3,4-c]pyrrolizidine skeleton showed α-glucosidase inhibitory activity with the IC50 values of 41.97 ± 0.97, 232.57 ± 11.45 and 243.95 ± 3.36 µM, respectively, and the binding modes were performed by silico docking studies.

2.
Sci Rep ; 11(1): 316, 2021 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-33431976

RESUMO

Maternal metabolism dysregulation during pregnancy predisposes offspring to major diseases, including hypertension, in later life, but the mechanism involved remains to be fully elucidated. A high-fat-diet (HFD) pregnant rat model was used to investigate whether excessive intrauterine lipid exposure was associated with elevated blood pressure in offspring and increased levels of leptin, an important biomarker and mediator of vascular dysfunction and hypertension. We found that gestational hyperlipidemia predisposed offspring to blood pressure elevation and sustained increases in leptin levels with no difference in body weight in the rat model. Increased leptin expression and leptin promoter hypomethylation were found in adipose tissues of HFD-exposed offspring. The treatment of mesenchymal stem cells with free fatty acids during adipogenic differentiation resulted in increased leptin expression, accompanied by leptin promoter hypomethylation. In addition, we also followed up 121 children to evaluate the association between maternal triglyceride levels and offspring blood pressure. Consistent with the animal study results, we observed elevated serum leptin levels and blood pressure in the offspring born to women with gestational hypertriglyceridemia. Our findings provide new insights that maternal hyperlipidemia is associated with elevated blood pressure in offspring and is associated with increases in leptin levels through epigenetic memory.

3.
BMC Cancer ; 21(1): 56, 2021 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-33435909

RESUMO

BACKGROUND: Surgery is the only treatment option for operable gastric cancer. The CLASSIC and ACTS-GC studies showed that the 5-year overall survival (OS) of patients with stage III gastric cancer undergoing D2 gastrectomy is still very low. Whether adjuvant nanoparticle albumin-bound paclitaxel (nab-paclitaxel) combined chemotherapy is more effective than the XELOX standard adjuvant chemotherapy in patients with stage III gastric cancer has not been confirmed. METHODS: This is a multicenter, open-label, phase III clinical study. In this trial, 616 patients with locally advanced stage III gastric cancer that underwent curative D2 radical surgery and achieved R0 are planned to be included. Patients will be randomized 1:1 to nab-paclitaxel combined with S-1 (AS) vs. oxaliplatin combined with capecitabine (XELOX). XELOX group: Patients assigned to the XELOX group received eight 3-week cycles of oral capecitabine (1000 mg/m2) twice daily on days 1-14 of each cycle plus intravenous oxaliplatin 130 mg/m2 on day 1 of each cycle. AS group: AS group received eight 3-week cycles of oral S-1 (80-120 mg) (< 1.25 m2, 40 mg; 1.25 to < 1.5 m2, 50 mg; and > 1.5 m2, 60 mg) twice daily on days 1-14 plus intravenous nab-paclitaxel 120 mg/m2 on days 1 and 8 of each cycle. The primary endpoint was the 3-year disease-free survival (3-year-DFS) defined as the time from randomisation to the time of recurrence of the original gastric cancer, development of a new gastric cancer, or death from any cause. The secondary endpoints were the overall survival, (defined as the time from the date of randomisation to date of death from any cause) and safety (any adverse event). DISCUSSION: Compared with previous studies, this study includes nab-paclitaxel based on S-1 adjuvant chemotherapy, which is expected to achieve better efficacy and lower toxicity than the standard treatment. This study is the first clinical study to evaluate the safety and efficacy of nab-paclitaxel combined with S-1 in patients with stage III gastric cancer after D2 radical resection. TRIAL REGISTRATION: This clinical trial has been registered with ClinicalTrials.gov, registration number: NCT04135781 , on October 20th, 2019.

4.
PLoS One ; 16(1): e0245071, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33411834

RESUMO

This research proposes new perspectives accounting for the uncertainty on 50% effective rates (ER50) as interval input for species sensitivity distribution (SSD) analyses and evaluating how to include this uncertainty may influence the 5% Hazard Rate (HR5) estimation. We explored various endpoints (survival, emergence, shoot-dry-weight) for non-target plants from seven standard greenhouse studies that used different experimental approaches (vegetative vigour vs. seedling emergence) and applied seven herbicides at different growth stages. Firstly, for each endpoint of each study, a three-parameter log-logistic model was fitted to experimental toxicity test data for each species under a Bayesian framework to get a posterior probability distribution for ER50. Then, in order to account for the uncertainty on the ER50, we explored two censoring criteria to automatically censor ER50 taking the ER50 probability distribution and the range of tested rates into account. Secondly, based on dose-response fitting results and censoring criteria, we considered input ER50 values for SSD analyses in three ways (only point estimates chosen as ER50 medians, interval-censored ER50 based on their 95% credible interval and censored ER50 according to one of the two criteria), by fitting a log-normal distribution under a frequentist framework to get the three corresponding HR5 estimates. We observed that SSD fitted reasonably well when there were at least six distinct intervals for the ER50 values. By comparing the three SSD curves and the three HR5 estimates, we shed new light on the fact that both propagating the uncertainty from the ER50 estimates and including censored data into SSD analyses often leads to smaller point estimates of HR5, which is more conservative in a risk assessment context. In addition, we recommend not to focus solely on the point estimate of the HR5, but also to look at the precision of this estimate as depicted by its 95% confidence interval.

5.
Environ Res ; 194: 110678, 2021 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-33417911

RESUMO

5-methylbenzotriazole (5-TTri) and 5-chlorobenzotriazole (CBT) are two benzotriazole derivatives widely used in various industrial and domestic applications. This paper reports on the photochemical behaviour of 5-TTri and CBT in aqueous solutions under UV radiation at 254 nm and the influences of pH, salinity, metal species and humic acid (HA) on their photo-transformation processes. The photolysis of 5-TTri and CBT under the exposure to UV light were found to follow the first-order reaction kinetic in all cases with half-lives ranging from 7.1 h to 24.3 h for 5-TTri and 5.1 h-20.5 h for CBT in various aqueous solutions containing metal ions and HA. The photolysis rates for both 5-TTri and CBT were strongly dependent on the solution pH value, and decreased with increasing solution pH. Salinity, metal species Cu2+ and Fe3+, and especially HA had inhibitory effects on the photolysis of 5-TTri and CBT under UV light irradiation at 254 nm. We proposed the tentative photo transformation schemes for both 5-TTri and CBT, which involved two photoproducts (4-methylaniline and N, N-diethylaniline- p-toluidine) and three photoproducts (4-chloroaniline, Aniline and 2,6-diethylaniline), respectively, via N-N and N-NH bond scission and dechlorination process.

6.
Anal Chim Acta ; 1143: 306-314, 2021 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-33384126

RESUMO

A polymer-film inertial microfluidic jigsaw (PIMJ) sorter with trapezoidal spiral channels using the jigsaw puzzle method was proposed to realize precise and high-throughput rare cell separation. The PIMJ sorter was fabricated by assembling laser-patterned polymer-film layers of different thicknesses. After illustrating the conceptual design and fabrication process, the effects of the cross-sectional dimension, particle size, and operational flow rate on particle focusing were systematically explored under a broad flow rate range. Then, the separation performances of the PIMJ sorter were characterized using the binary particle mixture and the blood samples spiked with four types of tumor cells. The results indicated that the complete separation of the binary particles with a minimum size difference of 2 µm was successfully realized at a high throughput up to 3000 µL/min. A high recovery ratio of 90.57%-94.14% and a high purity of 48.67%-79.05% were achieved for the separation of rare tumor cells from white blood cells (WBCs). Finally, the PIMJ sorter was successfully employed for separating rare circulating tumor cells (CTCs) from the metastatic breast and lung cancer patients with a capture ratio of 7-226 CTCs per 5 mL sample. The results proved the high sensitivity and high reliability of the PIMJ sorter. The PIMJ sorter is expected to be a potential device for precise CTC separation towards the clinical applications.

7.
Eur Radiol ; 2021 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-33389035

RESUMO

OBJECTIVES: Idiopathic normal pressure hydrocephalus (INPH) is a neurodegenerative disorder characterized by excess cerebrospinal fluid (CSF) in the ventricles, which can be diagnosed by invasive CSF drainage test and treated by shunt placement. Here, we aim to investigate the diagnostic and prognostic power of systematic volumetric analysis based on brain structural MRI for INPH. METHODS: We performed a retrospective study with a cohort of 104 probable INPH patients who underwent CSF drainage tests and another cohort of 41 INPH patients who had shunt placement. High-resolution T1-weighted images of the patients were segmented using an automated pipeline into 283 structures that are grouped into different granularity levels for volumetric analysis. Volumes at multi-granularity levels were used in a recursive feature elimination model to classify CSF drainage responders and non-responders. We then used pre-surgical brain volumes to predict Tinetti and MMSE scores after shunting, based on the least absolute shrinkage and selection operator. RESULTS: The classification accuracy of differentiating the CSF drainage responders and non-responders increased as the granularity increased. The highest diagnostic accuracy was achieved at the finest segmentation with a sensitivity/specificity/precision/accuracy of 0.89/0.91/0.84/0.90 and an area under the curve of 0.94. The predicted post-surgical neurological scores showed high correlations with the ground truth, with r = 0.80 for Tinetti and r = 0.88 for MMSE. The anatomical features that played important roles in the diagnostic and prognostic tasks were also illustrated. CONCLUSIONS: We demonstrated that volumetric analysis with fine segmentation could reliably differentiate CSF drainage responders from other INPH-like patients, and it could accurately predict the neurological outcomes after shunting. KEY POINTS: • We performed a fully automated segmentation of brain MRI at multiple granularity levels for systematic volumetric analysis of idiopathic normal pressure hydrocephalus (INPH) patients. • We were able to differentiate patients that responded to CSF drainage test with an accuracy of 0.90 and area under the curve of 0.94 in a cohort of 104 probable INPH patients, as well as to predict the post-shunt gait and cognitive scores with a coefficient of 0.80 for Tinetti and 0.88 for MMSE. • Feature analysis showed the inferior lateral ventricle, bilateral hippocampus, and orbital cortex are positive indicators of CSF drainage responders, whereas the posterior deep white matter and parietal subcortical white matter were negative predictors.

8.
Food Chem ; 337: 127798, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-32799166

RESUMO

In this study, polysaccharides (BPSs) were obtained from fresh bitter gourd (Momordica charantia L.) by room temperature extraction techniques, including three-phase partitioning (TPP) and ultrasonic-assisted extraction (UAE) performed in different solvents. The results showed that the extraction methods had significant influence on the extraction yield, chemical composition, weight-average molecular weight (Mw), monosaccharide composition, preliminary structural characterization and microstructure of the BPSs. The BPS-W sample obtained from the bitter gourd residue via UAE in distilled water had a higher uronic acid content (24.22%) and possessed stronger antioxidant capacities and α-amylase and α-glycosidase inhibitory activities than BPS-C extracted with UAE in citric acid, BPS-A extracted with UAE in 1.25 mol/L NaOH/0.05% NaBH4, and BPS-J extracted from bitter gourd juice by TPP. Moreover, BPS-A, which had the lowest Mws, showed the best bile acid-binding capacity among the four BPSs. This study had great potentials for the preparation of bioactive polysaccharides from fresh vegetables.


Assuntos
Fracionamento Químico/métodos , Momordica charantia/química , Polissacarídeos/isolamento & purificação , Antioxidantes/farmacologia , Polissacarídeos/química , Polissacarídeos/farmacologia , Temperatura , Ácidos Urônicos/análise , alfa-Amilases/antagonistas & inibidores , alfa-Glucosidases/efeitos dos fármacos
9.
Anal Biochem ; 612: 114012, 2021 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-33189703

RESUMO

A sandwich-type electrochemiluminescence (ECL) immunosensor based on the resonance energy transfer (RET) was proposed for ultrasensitive detection of cardiac troponin I (cTnI). The RET behavior could be generated between graphite carbon nitride nanosheets (m-CNNS) as donor and copper oxide@graphene oxide (CuO@GO) as acceptor, achieving the quenching effect of CuO@GO on m-CNNS for cTnI detection. The m-CNNS synthesized by mechanical grinding of the graphite carbon nitride (CN) not only has better dispersion and higher specific surface area, but also has high luminous efficiency and stable chemical properties. Therefore, m-CNNS was used as the matrix material and luminophore. As the acceptor, CuO@GO prepared by in-situ chemical synthesis of CuO NPs onto GO sheets also has a high specific surface area, which could be used as a label of secondary antibody (Ab2). Under optimal conditions, cTnI could be determined within the linear range of 0.1 pg mL-1 to 100 ng mL-1 and had a low detection limit (0.028 pg mL-1, S/N = 3). Meanwhile, the prepared ECL immunosensor possessed great stability, specificity and reproducibility, providing a new method for detecting cTnI and other biomarkers.

10.
J Am Chem Soc ; 143(1): 504-512, 2021 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-33370533

RESUMO

The successful use of electrochemiluminescence (ECL) in immunoassay for clinical diagnosis requires development of novel ECL signal probes. Herein, we report lanthanide (Ln) metal-organic frameworks (LMOFs) as ECL signal emitters in the ECL immunoassay. The LMOFs were prepared from precursors containing Eu (III) ions and 5-boronoisophthalic acid (5-bop), which could be utilized to adjust optical properties. Investigations of ECL emission mechanisms revealed that 5-bop was excited with ultraviolet photons to generate a triplet-state, which then triggered Eu (III) ions for red emission. The electron-deficient boric acid decreased the energy-transfer efficiency from the triplet-state of 5-bop to Eu (III) ions; consequently, both were excited with high-efficiency at single excitation. In addition, by progressively tailoring the atomic ratios of Ni/Fe, NiFe composites (Ni/Fe 1:1) were synthesized with more available active sites, enhanced stability, and excellent conductivity. As a result, the self-luminescent europium LMOFs displayed excellent performance characteristics in an ECL immunoassay with a minimum detectable limit of 0.126 pg mL-1, using Cytokeratins21-1 (cyfra21-1) as the target detection model. The probability of false positive/false negative was reduced dramatically by using LMOFs as signal probes. This proposed strategy provides more possibilities for the application of lanthanide metals in analytical chemistry, especially in the detection of other disease markers.

11.
Talanta ; 224: 121832, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33379050

RESUMO

An approximately monochromatic red upconversion (UC) emission is successfully realized in NaScF4: Yb3+/Er3+ nanoparticles (NPs) through Mn2+ ions doping without phase transition. The Mn2+ ions play a role of bridge during the energy transfer process from green emission state 2H11/2/4S3/2 of Er3+ to red emission state 4F9/2 of Er3+, which significantly accelerates the red UC enhancement. The strongest red luminescence is observed in the sample containing 10% Mn2+ ions (Mn-10) with an enhancement factor of 7.5 times. Meanwhile, an ultrasensitive optical thermometry in the physiological temperature region can be realized by utilizing the fluorescence intensity ratio (FIR) between two thermally coupled Stark transitions of Er3+: 4I13/2 â†’ 4I15/2, locating in the near-infrared (NIR) long wavelength region of the second biological window. Its relative sensitivity SR can be expressed by 340/T2, which is much higher than most optical thermometers based on thermally coupled Stark sublevels reported by the previous papers. Beyond that, an ex vivo experiment is designed to evaluate the penetration depth of the red and NIR emission of Mn-10 in the biological tissues, revealing that they can reach depth of at least 3 mm and 5 mm respectively. More importantly, the increasing tissue thickness has almost no effect on the FIR values. All the results show that the present sample is a promising bi-functional nano probe which can be used for bioimaging and temperature sensing in the deep tissues through the strong red UC emission and ultrasensitive NIR optical thermometer, respectively.

12.
Exp Neurol ; 336: 113532, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33245889

RESUMO

Increasing evidence suggests that microglial polarization plays an important role in the pathological processes of neuroinflammation following subarachnoid hemorrhage (SAH). Previous studies indicated that milk fat globule-epidermal growth factor-8 (MFG-E8) has potential anti-apoptotic and anti-inflammatory effects in cerebral ischemia. However, the effects of MFG-E8 on microglial polarization have not been evaluated after SAH. Therefore, the aim of this study was to explore the role of MFG-E8 in anti-inflammation, and its effects on microglial polarization following SAH. We established the SAH model via prechiasmatic cistern blood injection in mice. Double-immunofluorescence staining, western blotting and quantitative real-time polymerase chain reaction (q-PCR) were performed to investigate the expression and cellular distribution of MFG-E8. Two different dosages (1 and 5 µg) of recombinant human MFG-E8 (rhMFG-E8) were injected intracerebroventricularly (i.c.v.) at 1 h after SAH. Brain water content, neurological scores, beam-walking score, Fluoro-Jade C (FJC), and terminal deoxynucleotidyl transferase dUTP nick endlabeling staining (TUNEL) were measured at 24 h. Suppression of MFG-E8, integrin ß3 and phosphorylation of STAT3 were achieved by specific siRNAs (500 pmol/5 µl) and the STAT3 inhibitor Stattic (5 µM). The potential signaling pathways and microglial polarization were measured by immunofluorescence labeling and western blotting. SAH induction increased the levels of inflammatory mediators and the proportion of M1 cells, and caused neuronal apoptosis in mice at 24 h. Treatment with rhMFG-E8 (5 µg) remarkably decreased brain edema, improved neurological functions, reduced the levels of proinflammatory factors, and promoted the microglial to shift to M2 phenotype. However, knockdown of MFG-E8 and integrin ß3 via siRNA abolished the effects of MFG-E8 on anti-inflammation and M2 phenotype polarization. The STAT3 inhibitor Stattic further clarified the role of rhMFG-E8 in microglial polarization by regulating the protein levels of the integrin ß3/SOCS3/STAT3 pathway. rhMFG-E8 inhibits neuronal inflammation by transformation the microglial phenotype toward M2 and its direct protective effect on neurons after SAH, which may be mediated by modulation of the integrin ß3/SOCS3/STAT3 signaling pathway, highlighting rhMFG-E8 as a potential therapeutic target for the treatment of SAH patients.

13.
Hum Brain Mapp ; 42(3): 660-675, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33085836

RESUMO

A number of studies have indicated alterations of brain morphology in individuals with autism spectrum disorder (ASD); however, how ASD influences the topological organization of the brain cortex at different developmental stages is not yet well characterized. In this study, we used structural images of 492 high-functioning participants in the Autism Brain Imaging Data Exchange database acquired from 17 international imaging centers, including 75 autistic children (age 7-11 years), 91 adolescents with ASD (age 12-17 years), and 80 young adults with ASD (age 18-29 years), and 246 typically developing controls (TDCs) that were age, gender, handedness, and full-scale IQ matched. Cortical thickness (CT) and surface area (SA) were extracted and the covariance between cortical regions across participants were treated as a network to examine developmental patterns of the cortical topological organization at different stages. A center-paired resampling strategy was developed to control the center bias during the permutation test. Compared with the TDCs, network of SA (but not CT) of individuals with ASD showed reduced small-worldness in childhood, and the network hubs were reorganized in the adulthood such that hubs inclined to connect with nonhub nodes and demonstrated more dispersed spatial distribution. Furthermore, the SA network of the ASD cohort exhibited increased segregation of the inferior parietal lobule and prefrontal cortex, and insular-opercular cortex in all three age groups, resulting in the emergence of two unique modules in the autistic brain. Our findings suggested that individuals with ASD may undergo remarkable remodeling of the cortical topology from childhood to adulthood, which may be associated with the altered social and cognitive functions in ASD.

14.
Magn Reson Med ; 85(1): 404-412, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32720386

RESUMO

PURPOSE: Intravoxel incoherent motion (IVIM) imaging is widely used to evaluate microcirculatory flow, which consists of diffusive and ballistic flow components. We proposed a joint use of flow-compensated (FC) and non-compensated (NC) diffusion gradients to probe the fraction and velocity of ballistic flow in the placenta. METHODS: Forty pregnant women were included in this study and scanned on a 1.5T clinical scanner. FC and NC diffusion MRI (dMRI) sequences were achieved using a pair of identical or mirrored bipolar gradients. A joint FC-NC model was established to estimate the fraction (fb ) and velocity (vb ) of the ballistic flow. Conventional IVIM parameters (f, D, and D*) were obtained from the FC and NC data, separately. The vb and f·D*, as placental flow velocity measurements, were correlated with the umbilical-artery Doppler ultrasound indices and gestational ages. RESULTS: The ballistic flow component can be observed from the difference between the FC and NC dMRI signal decay curves. vb fitted from the FC-NC model showed strong correlations with umbilical-artery impedance indices, the systolic-to-diastolic (SD) ratio and pulsatility index (PI), with correlation coefficients of 0.65 and 0.62. The f·D* estimated from the NC data positively correlated with SD and PI, while the FC-based f·D* values showed weak negative correlations. Significant gestational-age dependence was also found in the flow velocity measurements. CONCLUSION: Our results demonstrated the feasibility of using FC and NC dMRI to noninvasively measure ballistic flow velocity in the placenta, which may be used as a new marker to evaluate placenta microcirculation.

15.
Magn Reson Med ; 85(1): 78-88, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32643240

RESUMO

PURPOSE: Oscillating gradient (OG) enables the access of short diffusion times for time-dependent diffusion MRI (dMRI); however, it poses several technical challenges for clinical use. This study proposes a 3D oscillating gradient-prepared gradient spin-echo (OGprep-GRASE) sequence to improve SNR and shorten acquisition time for OG dMRI on clinical scanners. METHODS: The 3D OGprep-GRASE sequence consisted of global saturation, diffusion encoding, fat saturation, and GRASE readout modules. Multiplexed sensitivity-encoding reconstruction was used to correct the phase errors between multiple shots. We compared the scan time and SNR of the proposed sequence and the conventional 2D-EPI sequence for OG dMRI at 30-90-mm slice coverage. We also examined the time-dependent diffusivity changes with OG dMRI acquired at frequencies of 50 Hz and 25 Hz and pulsed-gradient dMRI at diffusion times of 30 ms and 60 ms. RESULTS: The OGprep-GRASE sequence reduced the scan time by a factor of 1.38, and increased the SNR by 1.74-2.27 times compared with 2D EPI for relatively thick slice coverage (60-90 mm). The SNR gain led to improved diffusion-tensor reconstruction in the multishot protocols. Image distortion in 2D-EPI images was also reduced in GRASE images. Diffusivity measurements from the pulsed-gradient dMRI and OG dMRI showed clear diffusion-time dependency in the white matter and gray matter of the human brain, using both the GRASE and EPI sequences. CONCLUSION: The 3D OGprep-GRASE sequence improved scan time and SNR and reduced image distortion compared with the 2D multislice acquisition for OG dMRI on a 3T clinical system, which may facilitate the clinical translation of time-dependent dMRI.

16.
Food Chem ; 339: 128053, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-32947105

RESUMO

A biopolymer-polyphenol conjugate-stabilized oil-in-water emulsion system was established to improve the chemical stability and bioaccessibility of ß-carotene (BC). In this study, the emulsifying properties and contribution of a ferulic acid-grafted curdlan conjugate (Cur-D-g-FA) to the chemical stability of BC were investigated. Results showed that the emulsification ability of emulsions stabilized by Cur-D-g-FA remarkably increased with an increasing concentration from 0.05% to 0.8% (w/v) along with decreasing average droplet sizes, negatively charged zeta potentials, and uniform size distributions. The emulsions stabilized by 0.8% Cur-D-g-FA exhibited pronounced shear thinning and solid-like elastic properties as well as satisfactory oxidation stability. The emulsions stabilized by 0.8% Cur-D-g-FA had excellent ability to improve the chemical stability of BC when exposed to different environmental stresses and resulted in the favorable bioaccessibility of BC in vitro. The results prove that Cur-D-g-FA as a promising stabilizer has great potential to protect liposoluble nutrients in food-grade emulsion-delivery systems.


Assuntos
Ácidos Cumáricos/química , Emulsificantes/química , beta Caroteno/química , beta-Glucanas/química , Disponibilidade Biológica , Óleo de Milho/química , Emulsões/química , Armazenamento de Alimentos , Concentração de Íons de Hidrogênio , Concentração Osmolar , Oxirredução , beta Caroteno/farmacocinética
17.
Magn Reson Med ; 85(3): 1322-1334, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32970882

RESUMO

PURPOSE: To correct the temporal B0 drift in chemical exchange saturation transfer (CEST) imaging in real-time with extra free-induction-decay (FID) readout. THEORY AND METHODS: The frequency stabilization module of the recently proposed frequency-stabilized CEST (FS-CEST) sequence was further simplified by replacing the original three k-space lines of gradient-echo (GRE) readout with a single k-space line of FID readout. The B0 drift was quantified using the phase difference between the odd and even parts of the FID signal in the frequency stabilization module and then used to update the B0 frequency in the succeeding modules. The proposed FS-CEST sequence with FID readout (FID FS-CEST) was validated in phantoms and 16 human subjects on cross-vendor scanners. RESULTS: In the Siemens experiments, the FID FS-CEST sequence successfully corrected the user-induced B0 drift, generating consistent amide proton transfer-weighted (APTw) images and magnetization transfer ratio asymmetry (MTRasym ) spectra with those from the non-frequency-stabilized CEST (NFS-CEST) sequence without B0 drift. In the Philips experiments, the FID FS-CEST sequence produced more stable APTw images and MTRasym spectra than the NFS-CEST sequence in the presence of practical B0 drift. Quantitatively, the SD of the APTw signal values in the deep gray matter from 15 subjects was 0.26% for the FID FS-CEST sequence compared to 1.03% for the NFS-CEST sequences, with the fluctuations reduced by nearly three-quarters. CONCLUSIONS: The proposed FS-CEST sequence with FID readout can effectively correct the temporal B0 drift on cross-vendor scanners.

18.
Food Chem ; 335: 127666, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-32739821

RESUMO

Proanthocyanidins extracted from Chinese berry leaves (CBLPs) were heated with rice starch in aqueous solution to prepare polyphenols-starch complexes. The physicochemical properties of the complexes were characterized with XRD, DSC, RVA and FT-IR and starch constituents were also analyzed with an enzyme method. Results indicated that the addition of CBLPs destroyed the long ordered structure of rice starch rather than the short ordered structure, since the crystallinity decreased from 21.96% to 18.90% and the ratio of 1047 cm-1/1022 cm-1 showed little difference, consistent with the lower ΔH of complexes with higher CBLPs content. Additionally, the CBLPs-rice starch complexes showed a significantly lower content of rapidly digested starch (RDS, 45.64 ± 3.25%) than that of the native rice starch (67.76 ± 2.15%). These results indicated that CBLPs complexes with rice starch might be a novel way to prepare functional starch with slower digestion.


Assuntos
Lycium/química , Oryza/química , Folhas de Planta/química , Proantocianidinas/química , Amido/química , Varredura Diferencial de Calorimetria , Digestão , Proantocianidinas/isolamento & purificação , Proantocianidinas/metabolismo , Espectroscopia de Infravermelho com Transformada de Fourier , Amido/metabolismo , Amido/farmacocinética , Termogravimetria , Água/química , Difração de Raios X
19.
Chemosphere ; 262: 127828, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32763579

RESUMO

Cadmium (Cd) pollution is a widespread environmental problem that decreases crop production, destroys the microbial ecology of soil, and poses a severe risk to human health. Organo-chemical amendment is a cost-effective, eco-friendly, and community-acceptable widely applied an in situ technique for metal-contaminated farmland. In this study, we mixed lime, zeolite, calcium magnesium phosphate fertilizer, and biochar in a mixture ratio of 71:23:5:1 to form a mixed amendment. Field and laboratory experiments were conducted to study the effects of the mixed amendment on soil exchangeable Cd content, plant Cd accumulation, and soil microbial community. It was found that the application of 0.5% mixed amendment decreased exchangeable soil Cd by more than 85% and 64% in wheat and rice season, respectively, compared with control (CK), without increasing pH. Moreover, the application of 0.5% mixed amendment decreased Cd accumulation in grains by 22.9% and 41.2% in wheat and rice season, respectively, compared to CK. The result of phospholipid fatty acids (PLFAs) shows that the level of soil microbial diversity and species richness under mixed amendment treatments were higher than in lime treatment, indicating more copiotrophic conditions and faster rate of nutrient turnover in mixed amendment than pure lime treatment. Hence, it concluded that the mixed amendment has a strong effect on fixing exchangeable soil Cd and reducing the accumulation of Cd in crops. Finally, it was observed that the mixed amendment improved the soil microbial community structure and accelerate the rate of nutrient turnover by microbes under this favorable condition comparative to individual treatments.


Assuntos
Cádmio/química , Microbiota/efeitos dos fármacos , Microbiologia do Solo , Poluentes do Solo/química , Agricultura/métodos , Cádmio/análise , Cádmio/toxicidade , Compostos de Cálcio , Carvão Vegetal , Produtos Agrícolas , Poluição Ambiental , Recuperação e Remediação Ambiental/métodos , Fertilizantes , Humanos , Microbiota/fisiologia , Oryza/efeitos dos fármacos , Óxidos , Fosfatos , Rotação , Solo/química , Poluentes do Solo/análise , Poluentes do Solo/toxicidade , Triticum
20.
Mol Med Rep ; 23(1)2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33236154

RESUMO

Inonotus obliquus (IO) is an edible fungus that exerts various biological functions, including anti­inflammatory, antitumor and immunomodulatory effects. The present study was designed to investigate the role of IO extract (IOE) in myocardial ischemia/reperfusion (MI/R) and determine the exact molecular mechanisms. The left anterior descending coronary artery was ligated to establish the MI/R injury model in rats. IOE exhibited a novel cardioprotective effect, as shown by improvement in cardiac function and decrease in infarct size. Pretreatment with IOE activated antioxidant enzymes in cardiomyocytes, including glutathione peroxidase, superoxide dismutase and catalase. IOE pretreatment also induced the upregulation of NAD­dependent protein deacetylase sirtuin­1 (SIRT1) and downregulation of glucose­regulated protein 78, phosphorylated (p­) protein kinase R­like endoplasmic reticulum kinase, p­eukaryotic translation initiation factor 2 subunit α, C/EBP homologous protein and caspase­12. Furthermore, IOE alleviated endoplasmic reticulum (ER) stress­induced apoptosis in cardiomyocytes by decreasing the mRNA levels of caspase­12. IOE inhibited apoptosis induced by overexpression of pro­caspase­9 and pro­caspase­3. In summary, IOE pretreatment protects the heart against MI/R injury through attenuating oxidative damage and suppressing ER stress­induced apoptosis, which may be primarily due to SIRT1 activation.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA