Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.422
Filtrar
1.
Front Endocrinol (Lausanne) ; 12: 716082, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34335480

RESUMO

Objective: To analyze the incidence and risk factors for lateral lymph node metastases (LNMs) in T1a papillary thyroid carcinoma (PTC) with a focus on tumor location and size. Materials and Methods: The incidence of lateral LNM in 345 cases of T1a PTC was retrospectively analyzed. Univariate and multivariate analyses were performed to assess the relationships between lateral LNM and clinicopathological characteristics. Results: The incidence of skip metastasis to lateral LNM in T1a PTC located in the upper lobe was 12.1% (8/66). Logistic regression analysis indicated tumor size >5 mm (OR = 5.04, 95% CI = 1.79 to 14.18, P = 0.002), upper lobe location (OR = 7.68, 95% CI = 3.05-19.34, P < 0.001) and the number of central neck LNM (<2: OR = 24.79, 95% CI = 8.23-74.60, P < 0.001; ≥2: OR = 4.99, 95% CI = 1.95-12.73, P < 0.001) were independently associated with lateral LNM. Comparing the lateral and central LNM stratification based on tumor location revealed that both the incidences of lateral (33.3%) and central (30.3%) LNM of T1a PTC located in the upper lobe were higher than those of T1a PTC located in the middle and lower lobes. Of T1a PTC located in the upper lobe, the incidence of lateral LNM was 33.3% (22/66), which was higher than that [30.3% (20/66)] of central LNM. This finding is reversed in all T1a PTC cases and T1a PTC cases with tumor located in the middle and lower lobes. Conclusion: A particularly high likelihood of lateral LNM was observed in T1a PTC patients with tumor located in the upper lobe of the thyroid gland, especially the tumor >5 mm in size, which could be considered a risk factor for lateral LNM in the clinical management of T1a PTC.

2.
Huan Jing Ke Xue ; 42(7): 3127-3135, 2021 Jul 08.
Artigo em Chinês | MEDLINE | ID: mdl-34212638

RESUMO

To investigate the pollution characteristics and sources of atmospheric brown carbon (BrC) in Chongming Island, a background site of the Yangtze River Delta (YRD) region in China, PM2.5 samples collected from December 2018 to January 2019 were analyzed to determine their chemical compositions and optical properties. The results showed that the light absorption coefficient (Abs365,M) of BrC extracted by methanol at 365 nm was (5.39±3.33) M-1·m-1, which was 1.3 times of the water extracted BrC. Both increased significantly with the increase of pH values, suggesting that less acidic conditions can enhance the light absorption ability of BrC. In winter, both Abs365 and MAE365 (mass absorption efficiency) were higher in the nighttime than in the daytime. A strong linear correlation observed between Abs365 and levoglucosan (R2=0.72) indicated that many light absorbing substances in Chongming Island were derived from biomass burning emissions. During the campaign, nitro-aromatic compounds (NACs) and PAHs accounted for (1.5±1.1) ng·m-3 and (8.3±4.7) ng·m-3, respectively, contributing to 0.1% and 0.067% of the absorption of the total BrC at 365 nm, respectively. Positive matrix factorization (PMF) analysis further showed that biomass and fossil fuel combustions were the main sources of BrC in Chongming Island in winter, accounting for 56% of the total BrC, followed by secondary formation, accounting for 24% of the total BrC, with road dust contributing only 6%.


Assuntos
Poluentes Atmosféricos , Carbono , Aerossóis/análise , Poluentes Atmosféricos/análise , Carbono/análise , China , Monitoramento Ambiental , Combustíveis Fósseis
3.
Sci Total Environ ; 794: 148714, 2021 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-34225141

RESUMO

Aromatic hydrocarbons are one of the major precursors of atmospheric brown carbon (BrC) and both abundantly co-exist with NOx in the urban atmosphere especially in winter haze period. However, the impact of NOx on the formation of BrC derived from aromatic hydrocarbons is still not fully understood. In this study, the yield and light absorption of secondary organic aerosols (SOA) from toluene photooxidation under various nitrogen oxides (NO2) levels were investigated by using a 5 m3 photooxidation smog chamber. A trend of increase at first and then decrease in the SOA yield with an increasing NO2 concentration was observed. The acid-catalyzed heterogeneous reactions lead to the increase of SOA yield in the low-NO2 regime. The formation of low-volatility species might be suppressed at high-NO2 conditions is responsible for the decreased SOA yield. In contrast, light absorption and mass absorption coefficient (MAC) of the toluene-derived SOA continuously increased with the increasing NO2 concentrations. HR-ToF-AMS results showed that nitrogen-containing organic compounds (NOCs) are the main species that lead to the increase of the SOA light absorption. The ratio of CHN family to the total NOCs, which are derived from the nitro compounds, also increased dominantly with the increasing NO2 levels and accounted for more than half of the total NOCs when the NO2 concentration increased to 495 ppbv, indicating that nitro compounds rather than organic nitrates are the major light-absorbing species and preferably formed in the toluene oxidation process.

4.
Molecules ; 26(12)2021 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-34207684

RESUMO

Biodiesel is a promising candidate for sustainable and renewable energy and extensive research is being conducted worldwide to optimize its production process. The employed catalyst is an important parameter in biodiesel production. Metal-organic frameworks (MOFs), which are a set of highly porous materials comprising coordinated bonds between metals and organic ligands, have recently been proposed as catalysts. MOFs exhibit high tunability, possess high crystallinity and surface area, and their order can vary from the atomic to the microscale level. However, their catalytic sites are confined inside their porous structure, limiting their accessibility for biodiesel production. Modification of MOF structure by immobilizing enzymes or ionic liquids (ILs) could be a solution to this challenge and can lead to better performance and provide catalytic systems with higher activities. This review compiles the recent advances in catalytic transesterification for biodiesel production using enzymes or ILs. The available literature clearly indicates that MOFs are the most suitable immobilization supports, leading to higher biodiesel production without affecting the catalytic activity while increasing the catalyst stability and reusability in several cycles.


Assuntos
Biocombustíveis/análise , Biotecnologia/métodos , Enzimas Imobilizadas/química , Líquidos Iônicos/química , Estruturas Metalorgânicas/química , Catálise , Esterificação , Porosidade
5.
Environ Pollut ; 288: 117810, 2021 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-34329045

RESUMO

China has been famous for its porcelains for millennia, and the combustion processes of porcelain production emit substantial amounts of air pollutants, which have not been well understood. This study provided firsthand data of air pollutant emissions from biomass porcelain kilns. The emission factor of PM2.5 was 0.95 ± 1.23 g/kg during the entire combustion cycle, lower than that of biomass burning in residential stoves and coal burning in brick kilns, attributed to the removal effects of the long-distance transport in dragon kilns. The temporal trend of particle pollutants, including particulate matters (PMs) and particulate polycyclic aromatic hydrocarbons (PAHs) (low at ignition phase and high at the end) again indicated the removal effects of the special structure, while gaseous pollutants, such as gaseous PAHs, exhibited the opposite result. The GWC100 was estimated as 1.4 × 106 and 0.5 × 106 kg CO2e/yr for the scenarios in which 50% and 100% of the wood was renewable, respectively. The GWC100 of dragon kilns is nearly equal to that of 745 households using wood-fueled stoves. These results indicate the necessity of pollution controls for biomass porcelain kilns to estimate the emission inventory and climate change.

6.
Phys Chem Chem Phys ; 23(27): 14662-14670, 2021 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-34213518

RESUMO

Cation-π interactions are essential for many chemical, biological, and material processes, and these processes usually involve an aqueous salt solution. However, there is still a lack of a full understanding of the hydrated cation-π interactions between the hydrated cations and the aromatic ring structures on the molecular level. Here, we report a molecular picture of hydrated cation-π interactions, by using the calculations of density functional theory (DFT). Specifically, the graphene sheet can distort the hydration shell of the hydrated K+ to interact with K+ directly, which is hereafter called water-cation-π interactions. In contrast, the hydration shell of the hydrated Li+ is quite stable and the graphene sheet interacts with Li+ indirectly, mediated by water molecules, which we hereafter call the cation-water-π interactions. The behavior of hydrated cations adsorbed on a graphene surface is mainly attributed to the competition between the cation-π interactions and hydration effects. These findings provide valuable details of the structures and the adsorption energy of hydrated cations adsorbed onto the graphene surface.

7.
J Pain Palliat Care Pharmacother ; : 1-13, 2021 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-34280067

RESUMO

We evaluated the economic impact associated with preoperative meloxicam IV 30 mg vs placebo administration among adult total knee arthroplasty (TKA) recipients enrolled in Phase IIIB NCT03434275 trial. Data on total hospital costs and length of stay (LOS) obtained from the trial were compared between meloxicam IV 30 mg and placebo groups. Patients in the meloxicam IV 30 mg vs placebo group (n = 93 vs 88) incurred an adjusted $2,266 (95% CI: -$1,035, $5,116; p = 0.1689) lower total hospital costs and an adjusted 8.6% (95% confidence interval [CI]: -2.0%, 18.1%; p = 0.1082) shorter LOS. While statistically non-significant, based on 95% CIs, the results from this sub-study may suggest a favorable impact associated with meloxicam IV 30 mg on hospital costs and LOS.

8.
Biosensors (Basel) ; 11(6)2021 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-34201215

RESUMO

Anesthesia assessment is most important during surgery. Anesthesiologists use electrocardiogram (ECG) signals to assess the patient's condition and give appropriate medications. However, it is not easy to interpret the ECG signals. Even physicians with more than 10 years of clinical experience may still misjudge. Therefore, this study uses convolutional neural networks to classify ECG image types to assist in anesthesia assessment. The research uses Internet of Things (IoT) technology to develop ECG signal measurement prototypes. At the same time, it classifies signal types through deep neural networks, divided into QRS widening, sinus rhythm, ST depression, and ST elevation. Three models, ResNet, AlexNet, and SqueezeNet, are developed with 50% of the training set and test set. Finally, the accuracy and kappa statistics of ResNet, AlexNet, and SqueezeNet in ECG waveform classification were (0.97, 0.96), (0.96, 0.95), and (0.75, 0.67), respectively. This research shows that it is feasible to measure ECG in real time through IoT and then distinguish four types through deep neural network models. In the future, more types of ECG images will be added, which can improve the real-time classification practicality of the deep model.


Assuntos
Eletrocardiografia , Redes Neurais de Computação , Algoritmos , Arritmias Cardíacas , Humanos , Internet das Coisas
9.
Plant Physiol Biochem ; 167: 42-48, 2021 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-34332253

RESUMO

Grafting is a technique that provides a substantial way to enhance nutrient utilization thereby improves plant growth and yield quality. Although it is commonly practised in horticultural crops, the impact of scion-rootstock interaction on nutrient distribution is still unclear. Here, 'Newhall' navel orange plants grafted on Trifoliate orange (T) as the original rootstock were inarched with trifoliate orange (N/Tt combination) or carrizo citrange (N/Tc combination) rootstock seedlings. The experimental plants were treated with isotope 10B solution for 7 weeks to investigate the effect of different inarched rootstocks on B distribution and translocation by using a two-root system. From this study, the original rootstock played a more dominant role in B distribution to scion tissues than the inarching rootstock either in N/Tt or N/Tc combination. From inarched combinations, the carrizo citrange in the N/Tc combination had a higher ability to distribute B to new leaves, new twigs and old twigs than trifoliate orange in the N/Tt combination. However, the original rootstock of N/Tt distributed more B to scion tissues than N/Tc and the B concentration in old leaves and new leaves of N/Tt plants was significantly higher than that of N/Tc plants. These results suggest that scion B status is influenced by the B distribution of two inarching rootstocks in an inarching plant, as well as the affinity between the inarching rootstock and grafted plant. In addition, by either adding 10B to the inarching rootstock or original rootstock, we could detect 10B in the other rootstock root in both N/Tt and N/Tc combinations. The results further suggest that B can translocate from rootstock to leaves and then, re-translocate from scion to rootstock through the cycling of B transportation.

10.
Environ Pollut ; 284: 117493, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34261214

RESUMO

Polycyclic aromatic hydrocarbons (PAHs) in soil can be recalcitrant to solvent extraction after aging. We showed in this study that mixing a small amount of water in the extracting solvent during microwave-assisted extraction (MAE) can release recalcitrant PAHs, resulting in significant improvement in the analyzed concentrations. The improvement factor (F) for the total of 16 priority PAHs (∑PAH16) listed by the United States Environmental Protection Agency was 1.44-1.55 for field soils. By comparing the F values for different soil organic components, we demonstrated that the recalcitrant PAHs were primarily associated with biochar, humic acid (HA), and humin (HM), with the F values for ∑PAH16 of 1.94, 6.62, and 4.59, respectively. The results showed that the recalcitrant PAHs comprised a sequestered fraction and a desorption-limited fraction. NMR spectra showed that water worked alone at elevated temperature to promote hydrolysis of biochar and destroy the macromolecular structure, thus causing the release of the otherwise sequestered PAHs during MAE. The substantial reduction in F values for HA and HM after demineralization indicated sequestration of PAHs in organic-mineral complexes, which can be destroyed by hot water treatment. The release of the sequestered fraction was nonselective and independent of compound hydrophobicity. In comparison, the release of the desorption-limited fraction was positively affected by the hydrophobicity of PAHs and was facilitated by the presence of water in the extracting solvent. The results of this study provide important insights into the sequestration and release of recalcitrant PAHs in soil.


Assuntos
Hidrocarbonetos Policíclicos Aromáticos , Poluentes do Solo , Micro-Ondas , Hidrocarbonetos Policíclicos Aromáticos/análise , Solo , Poluentes do Solo/análise , Solventes , Água
11.
Oncol Rep ; 46(3)2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34278506

RESUMO

MicroRNAs play an important role in tumor cell proliferation, invasion, and Rab23 is a member of the Ras­related small GTPase family and plays a critical role in the progression of may types of tumors. The present study was designed to investigate the inhibitory effect of microRNA (miR)­367­3p on the proliferation, invasion, and metastasis of prostate cancer cells. qRT­PCR was used to detect the expression of miR­367­3p in prostate cancer and adjacent tissues. Cell proliferation, scratch, and Transwell assays were performed to verify the inhibitory effect of miR­367­3p overexpression or Ras­related protein Rab 23 (Rab23) knockdown on prostate cancer. Double luciferase reporter assay was utilized to verify whether miR­367­3p could target the Rab23 3'­untranslated region (UTR). The expression levels of Rab23, Gli1, and Gli2 in prostate cancer cells transfected with the miR­367­3p mimic were detected via qRT­PCR analysis. miR­367­3p expression in the prostate cancer tissues was downregulated compared with that in the para­cancer control tissues. miR­367­3p expression in DU145 and PC3 cells was also downregulated compared with that in the human prostate epithelial cell line RWPE­1. The overexpression of miR­367­3p or the knockdown of Rab23 inhibited the proliferation, invasion, and metastasis of prostate cancer cells. The results of the luciferase reporter assay confirmed that Rab23 was a target gene that was regulated by miR­367­3p. miR­367­3p specifically bound to the 3'­UTR of Rab23 mRNA. The overexpression of miR­367­3p inhibited Rab23 expression and the Hedgehog pathway. Cell function experiments confirmed that the overexpression of Rab23 reversed the anticancer effect of miR­367­3p. miR­367­3p was able to inhibit the Hedgehog pathway by targeting the expression of the Rab23 gene, thus inhibiting the proliferation, invasion, and metastasis of prostate cancer cells.

12.
Dis Colon Rectum ; 2021 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-34261858

RESUMO

BACKGROUND: Colectomy and proctocolectomy are the initial standard of care for patients with familial adenomatous polyposis. Pharmacotherapy to prevent progression of polyposis and surgeries in the lower gastrointestinal tract would be beneficial to patients with this disease. OBJECTIVE: This analysis aimed to evaluate the impact of eflornithine-sulindac combination versus monotherapy in delaying time to disease progression in the lower gastrointestinal tract of patients with familial adenomatous polyposis. DESIGN: This is a post-hoc analysis of a randomized phase 3 trial. SETTING: Twenty-one hospitals in 7 countries treating patients with familial adenomatous polyposis. PATIENTS: Adults with familial adenomatous polyposis were randomized 1:1:1 into 3 arms. INTERVENTIONS: Patients received either eflornithine (750 mg), sulindac (150 mg), or both once daily for up to 48 months. MAIN OUTCOME MEASURES: Efficacy was evaluated as time from randomization to predefined primary disease progression endpoints. RESULTS: Results are reported for the study population excluding patients who had undergone permanent ileostomies (n = 158). Disease progression was observed in 2/54 (3.7%), 9/53 (17.0%), and 10/51 (19.6%) patients with at least partial lower gastrointestinal tract in the combination, sulindac, and eflornithine arms, respectively, corresponding to risk reductions of 80% (p = 0.02) and 83% (p = 0.01) between combination and sulindac or eflornithine, respectively. When endoscopic excision of adenomas ≥10 mm in size were censored, the need for major surgery was observed in 0/54, 7/53 (13.2%), and 8/51 (15.7%) patients in the combination, sulindac, and eflornithine arms, respectively, corresponding to risk reductions approaching 100% between combination and sulindac (p = 0.005) or combination and eflornithine (p = 0.003). LIMITATIONS: This was a post-hoc analysis, the sample size was small, and there were fewer than expected events. CONCLUSIONS: Eflornithine-sulindac combination therapy was superior to either drug alone in delaying or preventing the need for lower gastrointestinal tract surgery in patients with familial adenomatous polyposis. See Video Abstract at http://links.lww.com/DCR/B658 .

13.
Environ Sci Technol ; 2021 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-34269570

RESUMO

Black carbon (BC) emissions, derived primarily from incomplete fuel combustion, significantly affect the global and regional climate. Mass absorption efficiency (MAE) is one important parameter in evaluating the climate impacts of BC. Here, values and variabilities in the MAE of BC (MAEBC) from real-world residential emissions were investigated from a field campaign covering 163 burning events for different fuel-stove combinations. MAEBC (average: 12 ± 5 m2/g) was normally distributed and varied greatly by 2 orders of magnitude. Statistically significant differences in MAEBC were found for various fuels, while no significant differences were observed among different stoves. The fuel difference explained 72 ± 7% of the MAEBC variation. MAEBC did not correlate with the modified combustion efficiency but positively correlated with the ratio of organic carbon (OC) to elemental carbon (EC) and negatively correlated with char-EC. The OC/EC ratio was not always lower in coal emissions in comparison to biomass burning emissions. Coal- and biomass-burning emissions had different profiles of carbon fractions. Char-EC, OC, OC/EC, and char-EC/soot-EC can explain 68.7% of the MAEBC variation, providing the potential for predicting MAEBC from the carbon fractions, since they are more commonly measured and available.

14.
Environ Int ; 156: 106736, 2021 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-34197973

RESUMO

Pyrethroid insecticides are widely applied due to the broad spectrum and high efficiency in pest control and detected in various environmental media, but the key factor affecting their occurrence and distribution in agricultural lands is still not clear. Here, we measured pyrethroid residues in 644 surface soil and 630 surface water samples and quantified the impacts of various factors on the distribution and partition of pyrethroids through a large-scale field study in Southeast China during 2015-2017. The pyrethroid residues were widely detected in the studied areas, and the mean concentration of seven individual pyrethroids in surface soil and water ranged from 0.10 (cyfluthrin, (CYF)) to 12.14 ng/g (bifenthrin, (BIF)) and 0.18 (CYF) to 3.36 µg/L (BIF) respectively, which were higher than other regions in China and some other countries. Using a generalized linear model coupled with dominance analysis, we found that the crop type and season were significantly associated with pyrethroid residues in surface soil and water (p < 0.05). The crop difference dominated the variances of the distribution of pyrethroid residues in the surface soil and water with a contribution of more than 55% and followed by the factor of season difference. The findings provide new insight into the distribution and partitioning of pyrethroids in agricultural lands and insecticide control on ecological safety and public health.

15.
Environ Pollut ; 288: 117696, 2021 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-34243081

RESUMO

Evidence about the adverse effects of methamphetamine (METH) on invertebrates is scarce. Hence, C. elegans, a representative invertebrate model, was exposed to METH at environmental levels to estimate chronic and transgenerational toxicity. The results of chronic exposure were integrated into an underlying toxicity framework of METH in invertebrates (e.g., benthos) at environmentally relevant concentrations. The induction of cellular oxidative damage-induced apoptosis and fluctuation of ecologically important traits (i.e., feeding and locomotion) might be attributed by the activation of the longevity regulating pathway regulated by DAF-16/FOXO, and detoxification by CYP family enzymes. The adverse effects to the organism level included impaired viability and decreased fecundity. The results from transgenerational exposure elucidated the cumulative METH-induced damage in invertebrates. Finally, a new risk assessment method named toxicity indicator sensitivity distribution (TISD) analysis was proposed by combining multiple toxicity indicator test data (ECx) to derive the hazardous concentration for 10% indicators (C10) of one species. The risk quotient (RQ) values calculated by measured environmental concentrations and C10 in southern China, southeastern Australia, and the western US crossed the alarm line (RQ = 5), suggesting a need for long-term monitoring.

16.
Sci Total Environ ; 796: 148927, 2021 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-34271385

RESUMO

This study aimed to investigate the biotransformation of ZnO nanoparticles (NPs) in maize grown in hydroponics for ecotoxicity assessment. Maize seedlings grown for 14 days were exposed to a solution of 9 nm ZnO NPs, 40 nm ZnO NPs, and ZnSO4 at a Zn concentration of 300 mg L-1 for 1, 3, and 7 days, respectively. The results of in-situ Zn distribution in maize (Zea mays) showed that 9 nm ZnO NPs could quickly enter the roots of maize and reach the center column transport system of the stem. The results of transmission electron microscopy combined with energy dispersive X-ray spectroscopy revealed that ZnO NPs were accumulated in the vacuoles of the roots, and then transformed and transported through vesicles. Simulated studies showed that low pH (5.6) played a critical role in the transformation of ZnO NPs, and organic acids (Kf = 1011.4) could promote particle dissolution. Visual MINTEQ software simulated the species of Zn after the entry of ZnO NPs or Zn2+ into plants and found that the species of Zn was mainly Zn2+ when the Zn content of plants reached 200-300 ppm. Considering that the lowest Zn content of the roots in treatments was 1920 mg kg-1, combination of the result analysis of root effects showed that the toxicity of roots in most treatments had a direct relationship with Zn2+. However, treatment with 9 nm ZnO NPs exhibited significantly higher toxicity than ZnSO4 treatment on day 1 when the Zn2+ concentration difference was not significant, which was mainly due to the large amount of ZnO NPs deposited in the roots. To the authors' knowledge, this study was the first to confirm the process of biotransformation and explore the factors affecting the toxicity of ZnO NPs in depth.

17.
Sci Total Environ ; 793: 148555, 2021 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-34171809

RESUMO

The effective removal of refractory antidepressant in wastewater is challenging. In this study, a novel strategy of cysteine-assisted Fe2+/persulfate system (Fe2+/Cys/PS) was applied for the venlafaxine (Ven, as a typical antidepressant) degradation. The obtained results revealed that the Ven removal was evidently accelerated and enhanced in Fe2+/Cys/PS process, and achieved complete degradation in 5 min with optimal dosage. Further analysis indicated that the Ven degradation efficiency was associated with the chemical concentrations (i.e. Fe2+, Cys and PS) and operational conditions (i.e. pH and temperature). Moreover, the reactions were not impacted by the co-occurring organic matters (i.e. fulvic acid) and inorganic ions (i.e. Cl-) potentially existing in real wastewater matrices. Mechanistic explorations demonstrated that the presence of Cys promoted the Fe3+/Fe2+ redox cycle, and thus enhanced the reactive oxygen species yields (ROS). The OH was considered as the primary ROS in Fe2+/Cys/PS process for Ven degradation via the radical scavenger verification. Also, the main intermediates of Ven degradation were identified, and the possible transformation pathway was proposed, in which the hydroxylation attacked by the OH was the main reaction. Moreover, the active reaction sites in Ven were calculated with the density function theory (DFT), which was consistent with the observed metabolic routes.

18.
J Agric Food Chem ; 69(25): 7218-7229, 2021 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-34151566

RESUMO

The characteristics of flavonoid metabolism in different Tartary buckwheat (TB) tissues and the related gene regulation network are still unclear at present. One hundred forty-seven flavonoids were identified from six TB tissues using the ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method. The roadmap of the rutin synthesis pathway was revealed. Through transcriptomic analysis it was revealed that the differentially expressed genes (DEGs) are mainly enriched in the "Phenylpropanoid biosynthesis" pathway. Fifty-two DEGs involved in the "flavonol synthesis" pathway were identified. The weighted gene correlation network analysis revealed four co-expression network modules correlated with six flavonol metabolites. Eventually, 74 genes revealed from MEblue and MElightsteelblue modules were potentially related to flavonol synthesis. Of them, 7 MYB transcript factors had been verified to regulate flavonoid synthesis. Furthermore, overexpressed FtMYB31 enhanced the rutin content in vivo. The present findings provide a dynamic flavonoid metabolism profile and co-expression network related to rutin synthesis and are thus valuable in understanding the molecular mechanisms of rutin synthesis in TB.


Assuntos
Fagopyrum , Transcriptoma , Cromatografia Líquida , Fagopyrum/genética , Flavonoides , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Metaboloma , Espectrometria de Massas em Tandem
19.
Chemistry ; 2021 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-34115398

RESUMO

Mitochondria are key organelles that perform vital cellular functions such as those related to cell survival and death. The targeted delivery of different types of cargos to mitochondria is a well-established strategy to study mitochondrial biology and diseases. Of the various existing mitochondrion-transporting vehicles, most suffer from poor cytosolic entry, low delivery efficiency, limited cargo types, and cumbersome preparation protocols, and none was known to be universally applicable for mitochondrial delivery of different types of cargos (small molecules, proteins, and nanomaterials). Herein, two new cell-penetrating, mitochondrion-targeting ligands (named MitoLigand ) that are capable of effectively "tagging" small-molecule drugs, native proteins and nanomaterials are disclosed, as well as their corresponding chemoselective conjugation chemistry. Upon successful cellular delivery and rapid endosome escape, the released native cargos were found to be predominantly localized inside mitochondria. Finally, by successfully delivering doxorubicin, a well-known anticancer drug, to the mitochondria of HeLa cells, we showed that the released drug possessed potent cell cytotoxicity, disrupted the mitochondrial membrane potential and finally led to apoptosis. Our strategy thus paves the way for future mitochondrion-targeted therapy with a variety of biologically active agents.

20.
J Colloid Interface Sci ; 602: 344-354, 2021 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-34139532

RESUMO

The lotus seedpod-based activated carbon (LSAC) is derived from pyrolysis of lotus seedpod as biomass carbon precursor, and Co3O4 is then deposited to LSAC by oxidation-precipitation and crystallization process of Co ions from Co(NO3)2 solution. The Co3O4 particles uniformly decorate on the surface and/or the inner channels of LSAC. The optimal reflection loss (RL) value of LSAC/Co3O4-paraffin wax (PW) composite reaches -39.8 dB, and the bandwidth for RL below -10 dB and -20 dB are 10.3 and 3.0 GHz, respectively, much better than that of LSAC-PW composite for the higher magnetic loss. The addition of Co3O4 particles in LSAC-PW composite significantly enhance the RL values in various thicknesses. The channels of the LSAC and decorated Co3O4 can improve the abilities of multiple scattering, dipole polarization, interface polarization and magnetic loss. This composite provides a promising method to construct high performance absorbers by using biomass carbon to tune the dielectric properties of the ferromagnetic materials.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...