Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 2.326
Filtrar
1.
J Colloid Interface Sci ; 607(Pt 2): 1333-1342, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34583038

RESUMO

Li-rich disordered rock-salt cathode (DRX) materials with advantage of low cost, long cycle life, nature abundant resource and high power and energy density attracted a great deal of scholarly attention. However, the poor cycle stability and the unclear realization of cation and anion redox activity in low-cost element system have severely hindered the construction of high-performance DRX. Herein, a promising class of Ti-Mn based cathode materials Li1.25Mn0.25Nb0.25Ti0.25O2 and Li1.25Mn0.25Ti0.5O1.75F0.25 were designed and successfully synthesized to construct high energy density DRX and investigate the effect of fluorination on cation and anion redox activity. The results show that both fluoridized and unfluoridized DRX possess a similar structure (Fm-3 m), but distinctly different charge/discharge profiles. The fluoridized cathode shows high initial charge/discharge capacity of 317.3/283.9 mAh g-1, specific energy density of 1370.4/735.5 Wh kg-1 and stable capacity retention with a discharge capacity of 202.6 mAh g-1 after 20 cycles at 20 mA g-1. Combining relevant spectroscopic results and HRTEM images, we revealed that the excellent cyclability of Li1.25Mn0.25Ti0.5O1.75F0.25 is rooted in the weakened adverse effects of moderated oxygen redox and the reduced Jahn-Teller distortion effect resulting from Mn3+, endowing the fluoridized DRX with better structural stability and larger Mn2+/Mn4+ reservoir. The strategy of constructing low cost oxyfluoride and the understanding of the mechanism of fluorination induced cation and anion redox activity would provide reference for the development of high-performance DRX materials.

2.
Food Chem ; 370: 131360, 2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-34662796

RESUMO

A novel deep eutectic solvent-based extraction and sulfur-doped carbon quantum dots (S-CQDs) serving as fluorescence probes to detect pirimicarb in cereals were established. The deep eutectic solvent was synthesized using choline chloride and butanediol, achieving direct and efficient extraction of pirimicarb residue in the cereals. The fluorescence quenching of S-CQDs was caused by the electrostatic interaction between the negatively charged S-CQDs and positively charged thiocholine, which was the hydrolysate of acetylthiocholine. The fluorescence of S-CQDs was enhanced as the activity of acetylcholinesterase (AChE) was inhibited by pirimicarb, achieving the detection of pirimicarb in the cereal samples. The limit of detection (LOD) was 0.006 µg mL-1. The recovery ranged from 96.6% to 108.2%. This extraction and detection method of pirimicarb based on an environmentally friendly DES and S-CQD fluorescent sensor maintains good stability and convenience, offering a promising strategy for extracting and testing harmful substances in food samples.


Assuntos
Grão Comestível , Pontos Quânticos , Acetilcolinesterase , Carbamatos , Pirimidinas , Solventes
3.
Pattern Recognit ; 122: 108341, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34565913

RESUMO

Segmentation of infections from CT scans is important for accurate diagnosis and follow-up in tackling the COVID-19. Although the convolutional neural network has great potential to automate the segmentation task, most existing deep learning-based infection segmentation methods require fully annotated ground-truth labels for training, which is time-consuming and labor-intensive. This paper proposed a novel weakly supervised segmentation method for COVID-19 infections in CT slices, which only requires scribble supervision and is enhanced with the uncertainty-aware self-ensembling and transformation-consistent techniques. Specifically, to deal with the difficulty caused by the shortage of supervision, an uncertainty-aware mean teacher is incorporated into the scribble-based segmentation method, encouraging the segmentation predictions to be consistent under different perturbations for an input image. This mean teacher model can guide the student model to be trained using information in images without requiring manual annotations. On the other hand, considering the output of the mean teacher contains both correct and unreliable predictions, equally treating each prediction in the teacher model may degrade the performance of the student network. To alleviate this problem, the pixel level uncertainty measure on the predictions of the teacher model is calculated, and then the student model is only guided by reliable predictions from the teacher model. To further regularize the network, a transformation-consistent strategy is also incorporated, which requires the prediction to follow the same transformation if a transform is performed on an input image of the network. The proposed method has been evaluated on two public datasets and one local dataset. The experimental results demonstrate that the proposed method is more effective than other weakly supervised methods and achieves similar performance as those fully supervised.

4.
Neural Regen Res ; 17(2): 370-377, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34269212

RESUMO

High-frequency spinal cord stimulation (HF-SCS) has been established as an effective therapy for neuropathic pain. However, the analgesic mechanisms involved in HF-SCS remain to be clarified. In our study, adult rat neuropathic pain was induced by spinal nerve ligation. Two days after modeling, the rats were subjected to 4 hours of HF-SCS (motor threshold 50%, frequency 10,000 Hz, and pulse width 0.024 ms) in the dorsal horn of the spinal cord. The results revealed that the tactile allodynia of spinal nerve-injured rats was markedly alleviated by HF-SCS, and the effects were sustained for 3 hours after the stimulation had ceased. HF-SCS restored lysosomal function, increased the levels of lysosome-associated membrane protein 2 (LAMP2) and the mature form of cathepsin D (matu-CTSD), and alleviated the abnormally elevated levels of microtubule-associated protein 1A/B-light chain 3 (LC3)-II and sequestosome 1 (P62) in spinal nerve-injured rats. HF-SCS also mostly restored the immunoreactivity of LAMP2, which was localized in neurons in the superficial layers of the spinal dorsal horn in spinal nerve-injured rats. In addition, intraperitoneal administration of 15 mg/kg chloroquine for 60 minutes reversed the expression of the aforementioned proteins and shortened the timing of the analgesic effects of HF-SCS. These findings suggest that HF-SCS may exhibit long-lasting analgesic effects on neuropathic pain in rats through improving lysosomal dysfunction and alleviating autophagic flux. This study was approved by the Laboratory Animal Ethics Committee of China Medical University, Shenyang, China (approval No. 2017PS196K) on March 1, 2017.

5.
J Hazard Mater ; 421: 126718, 2022 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-34339986

RESUMO

Para-Nitrophenol (p-nitrophenol) is a common industrial pollutant occurring widely in water bodies, yet actual monitoring methods are limited. Herein we proposed a fully electrochemically in situ synthesized graphene-polyarginine composite functionalized screen printed electrode, as a novel p-nitrophenol sensing platform. The electrode was characterized by morphologic, spectrometric and electrochemical techniques. p-nitrophenol in both pure aqueous solution and real water samples was tested. Results show a detection limit as low as the nanomolar level, and display a linear response and high selectivity in the range of 0.5-1250 µM. Molecular simulation reveals a detailed synergy between graphene and poly-arginine. The preferable orientation of nitrophenol molecules on the graphene interface in the presence of poly-arginine induces H- and ionic binding. This sensor is an ideal prototype for p-nitrophenol quantification in real waters.


Assuntos
Grafite , Arginina , Técnicas Eletroquímicas , Eletrodos , Nitrofenóis
6.
J Colloid Interface Sci ; 605: 60-70, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34303925

RESUMO

The exploitation of excellent performance form-stable phase change material composites (FS-PCMCs) with enhanced photothermal conversion efficiency and high phase change latent heat is of great significance for thermal energy storage. In this work, a new type of FS-PCMCs with superior light-to-thermal conversion performance were created by impregnation of organic phase change material (1-hexadecylamine (HDA) and 1-tetradecylamine (TDA)) into the graphene aerogel (GA) and all-carbon aerogel (GCA) through a simple direct infusion. The multiwalled carbon nanotubes (MWCNTs) are wound around the inner wall of the GA layer to form a three-dimensional (3D) porous network structure to support fatty amine (FAs), thus achieving shape stability before and after phase transition. Moreover, the FS-PCMCs has extremely high phase transition enthalpy (203.1-248 kJ·kg-1) and good recyclability. More importantly, due to the high absorbance of GCA, it can enhance its light absorption capacity and reduce thermal radiation. The light-to-thermal conversion efficiency of the FS-PCMCs is 72.36%-88.25%. Taking the improvement of the comprehensive properties of the FS-PCMCs, the results of this work may open up a way for rational design and preparation of high-performance FS-PCMCs with enhanced storage capacity and light-to-thermal conversion efficiency for the efficient utilization of solar energy.


Assuntos
Grafite , Nanotubos de Carbono , Temperatura Alta , Transição de Fase , Porosidade
7.
J Sci Food Agric ; 102(1): 250-258, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34091922

RESUMO

BACKGROUND: Sesame oil has an excellent flavor and is widely appreciated. It has a higher price than other vegetable oils because of the high price of its raw materials, and different processing techniques also result in products of different quality levels, which can command different prices. In the market, there is a persistent problem of adulteration of sesame oil, driven by economic interests. The screening of volatile markers used to distinguish the authenticity of sesame oil raw materials and production processes is therefore very important. RESULTS: In this work, six markers related to the production processes and raw materials of sesame oil were screened by gas chromatography-tandem mass spectrometry (GC-MS/MS) combined with chemometric analysis. They were 3-methyl-2-butanone, 2-ethyl-5-methyl-pyrazine, guaiacol, 2,6-dimethyl-pyrazine, 5-methyl furfural, and ethyl-pyrazine. The concentration of these markers in sesame oil is between 10 and1000 times that found in other vegetable oils. However, only 3-methyl-2-butanone and 2-ethyl-5-methyl-pyrazine differed significantly as the result of the use of different production processes. Except for guaiacol, which was mainly derived from raw materials, the other five compounds mentioned above all result from the Maillard reaction during thermal processing. The six compounds mentioned above are sufficient to distinguish fraud involving sesame oil raw materials and production processes, and can identify accurately adulteration levels of 30% concentration. CONCLUSION: In this study, the classification markers can identify the adulteration of sesame oil accurately. These six compounds are therefore important for the authenticity of sesame oil and provide a theoretical basis for the rapid and accurate identification of the authenticity of sesame oil. © 2021 Society of Chemical Industry.


Assuntos
Contaminação de Alimentos/análise , Produtos Finais de Glicação Avançada/análise , Guaiacol/análise , Óleo de Gergelim/análise , Aromatizantes/análise , Furaldeído/análise , Cromatografia Gasosa-Espectrometria de Massas , Reação de Maillard
8.
Environ Pollut ; 292(Pt A): 118317, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34634407

RESUMO

Neonicotinoids have been often detected in aquatic environment with high concentrations; however, little is known about their risk and fate to/in fish. This study systematically investigated the bio-uptake, tissue distribution and metabolism of neonicotinoids in zebrafish, taking clothianidin (CLO) as an example. The results revealed the uptake and elimination kinetics of CLO in whole fish and different tissues was very similar, and its bioconcentration factor (<1) indicates the low bioaccumulation potential in zebrafish. The highest accumulative tissues for CLO were found to be intestine and liver. Eight biotransformation products were identified in intestine and liver, and the metabolic pathways were found to be N-demethylation and nitro-reduction. The metabolic kinetics of two products (desmethyl clothianidin and clothianidin urea) revealed the metabolism of CLO mainly occurred in liver and intestine. This suggested that the hepatobiliary system played an important role in the metabolism and elimination of CLO. This study provides a comprehensive evaluation of the toxicokinetics of CLO in zebrafish, and these results can contribute to its ecological risk assessment.


Assuntos
Inseticidas , Animais , Guanidinas/toxicidade , Inseticidas/toxicidade , Neonicotinoides/toxicidade , Tiazóis , Distribuição Tecidual , Peixe-Zebra
9.
Food Chem ; 372: 131322, 2022 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-34818740

RESUMO

In this work, based on a specific antibody was obtained from the Protein Data Bank (PDB), a library of the specific peptides of aflatoxin B1 (AFB1) was constructed by combining key amino acids, amino acid mutations and molecular docking. Then, the porous gold nanoparticles (porous AuNPs) were fabricated on the surface of a glassy carbon electrode (GCE). A novel, sensitive and no-label signal immunosensor was developed by signal enhancement with the specific peptide as the recognition element for the detection of AFB1 in cereals. Under the optimal conditions, the limit of detection (S/N = 3) was 9.4 × 10-4 µg·L-1, and the linear range was 0.01 µg·L-1 to 20 µg·L-1. The recovery results were 88.4%∼102.0%, which indicated an excellent accuracy. This sensor is an ideal candidate for screening the peptides of AFB1, and a novel immunosensor was used to detect AFB1 in cereals.


Assuntos
Técnicas Biossensoriais , Nanopartículas Metálicas , Aflatoxina B1/análise , Técnicas Eletroquímicas , Ouro , Imunoensaio , Limite de Detecção , Simulação de Acoplamento Molecular , Peptídeos
10.
Biosens Bioelectron ; 197: 113755, 2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-34740119

RESUMO

A hydrophobic carboxyl functionalized phosphonium-based ionic liquid (IL) ((5-carboxypentyl) triphenylphosphonium bis (trifluoromethyl)sulfonyl) amide, TPP-HA[TFSI]) was synthesized through a simple hydrothermal approach. Based on the π-π and cation-π interactions with multi-wall carbon nanotubes (MWCNTs), a TPP-HA[TFSI]@MWCNTs hybrid was prepared to immobilize hemoglobin (Hb) to fabricate a simple and effective electrochemical sensing platform for the detection of methyl parathion (MP) in vegetables. Spectroscopic and electrochemical results show that TPP-HA[TFSI]@MWCNTs substrate synergistically provided a good biocompatible microenvironment for Hb, and the hydrophobicity of TPP-HA[TFSI] and the π-π interaction and hydrogen bonding between TPP-HA[TFSI]@MWCNTs, Hb and nafion (NF) were conducive to maintain the stability and integrity of the modified electrode interface. The TPP-HA[TFSI]@MWCNTs with large surface area and high conductivity promoted the exposure of the electroactive center of Hb and the direct electron transfer between Hb and the electrode, which effectively amplified the electrochemical signal and improved the sensitivity of MP detection. The constructed electrochemical sensing platform had a wider linear range (2-14 ng mL-1) and a lower detection limit (0.62 ng mL-1) for MP, and had acceptable repeatability, reproducibility, stability and anti-interference ability. This results indicated that the phosphonium-based ILs functionalized MWCNTs was an effective substrate for the immobilization of biological components, which have broad prospect in the construction of electrochemical sensing interfaces.

11.
Stroke ; : STROKEAHA121035506, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34847706

RESUMO

BACKGROUND AND PURPOSE: Language dysfunction is rarely seen in patients with unruptured brain arteriovenous malformation (AVM) albeit the AVM nidus involving language areas, which provides a unique disease model to study language reorganization. The objective of this study was to investigate the impairment and reorganization patterns and characteristics of language-related white matter in AVMs located at different brain areas. METHODS: Thirty-three patients with AVMs involving language areas were prospectively enrolled. Patients were categorized into 3 groups according to the lesion locations: the frontal (14 patients), temporal (15 patients), and parietal groups (4 patients). Thirty age- and sex-matched healthy controls were enrolled as comparison. All participants underwent diffusion tensor imaging scans, and automated fiber quantification method was applied to quantitatively study the difference of segmented language-related white matter connectivity between 3 AVM groups and control group. RESULTS: Language functions were normal in all subjects according to Western Aphasia Battery test. In the frontal group, fractional anisotropy (FA) value decreased in the left arcuate fascicle and increased in left superior longitudinal fasciculus and uncinate fascicle; in the temporal group, FA values decreased in left inferior fronto-occipital fascicle and inferior longitudinal fascicle and increased in right anterior thalamic radiation and uncinate fascicle; in the parietal group, FA values decreased in left arcuate fascicle and inferior longitudinal fascicle and increased in bilateral anterior thalamic radiations and uncinate fascicles and right inferior fronto-occipital fascicle. In fascicles with decreased FA values, the increase of radial diffusivity was common, and fascicles with increased FA values usually presented along with increased axial diffusivity values. CONCLUSIONS: Remodeling of language-related white matter occurs when traditional language areas are involved by AVM nidus, and its reorganization patterns vary with locations of AVM nidus. Fascicle impairment is mainly caused by the myelin deficits, and its plasticity may be dominated by the axon remodeling procedure.

12.
Eur J Endocrinol ; 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34851859

RESUMO

OBJECTIVE: Long-term outcomes (especially mortality and/or major cardiovascular events [MACE]) of the unilateral primary aldosteronism (uPA) patients who underwent medical or surgery targeted treatment, relative to those with essential hypertension (EH), have been scarcely reported. DESIGN AND SETTINGS: Using the prospectively designed observational TAIPAI cohort, we identified 858 uPA cases among 1220 primary aldosteronism (PA) patients and another 1210 EH controls. EXPOSURES Operated uPA patients were grouped via their 1-year post-therapy statuses. RESULTS PASO clinical complete success (hypertension-remission) was achieved in 272 (49.9%) of 545 surgically-treated uPA patients. After follow-up for 6.3±4.0 years, both hypertension-remissive (HR, 0.54, p< 0.001) and not-cured (HR, 0.61, p< 0.001) uPA patients showed a lower risk of all-cause mortality than that of EH controls; whereas the not-cured group had a higher risk of incident MACE (sub-hazard ratio (sHR), 1.41, p= 0.037) but similar atrial fibrillation (Af) and congestive heart failure (CHF). Mineralocorticoid receptor antagonist (MRA)-treated uPA patients had higher risks of MACE (sHR, 1.38, p= 0.033), Af (sHR,1.62, p= 0.049) and CHF (sHR, 1.44, p= 0.048) than those of EH controls, with mortality as a competing risk. Using inverse probability of treatment-weighted matching and counting adrenalectomy as a time-varying factor, treatment with adrenalectomy was associated with lower risks of all-cause mortality (HR 0.57; p= 0.035), MACE (HR 0.67; p= 0.037) and CHF (HR 0.49; p= 0.005) compared to those of MRA therapy. CONCLUSIONS: Adrenalectomy, independent of post-surgical hypertension remission, was associated with lower all-cause mortality of uPA patients, compared to that of EH patients. We further documented a more beneficial effect of adrenalectomy over MRA treatment on long-term mortality, MACE, and CHF in uPA patients.

13.
Asian J Pharm Sci ; 16(5): 643-652, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34849169

RESUMO

Disulfide bond-bridging strategy has been extensively utilized to construct tumor specificity-responsive aliphatic prodrug nanoparticles (PNPs) for precise cancer therapy. Yet, there is no research shedding light on the impacts of the saturation and cis-trans configuration of aliphatic tails on the self-assembly capacity of disulfide bond-linked prodrugs and the in vivo delivery fate of PNPs. Herein, five disulfide bond-linked docetaxel-fatty acid prodrugs are designed and synthesized by using stearic acid, elaidic acid, oleic acid, linoleic acid and linolenic acid as the aliphatic tails, respectively. Interestingly, the cis-trans configuration of aliphatic tails significantly influences the self-assembly features of prodrugs, and elaidic acid-linked prodrug with a trans double bond show poor self-assembly capacity. Although the aliphatic tails have almost no effect on the redox-sensitive drug release and cytotoxicity, different aliphatic tails significantly influence the chemical stability of prodrugs and the colloidal stability of PNPs, thus affecting the in vivo pharmacokinetics, biodistribution and antitumor efficacy of PNPs. Our findings illustrate how aliphatic tails affect the assembly characteristic of disulfide bond-linked aliphatic prodrugs and the in vivo delivery fate of PNPs, and thus provide theoretical basis for future development of disulfide bond-bridged aliphatic prodrugs.

14.
Clin Chem Lab Med ; 2021 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-34773728

RESUMO

OBJECTIVES: A large number of people undergo annual health checkup but accurate laboratory criterion for evaluating their health status is limited. The present study determined annual biological variation (BV) and derived parameters of common laboratory analytes in order to accurately evaluate the test results of the annual healthcare population. METHODS: A total of 43 healthy individuals who had regular healthcare once a year for six consecutive years, were enrolled using physical, electrocardiogram, ultrasonography and laboratory. The annual BV data and derived parameters, such as reference change value (RCV) and index of individuality (II) were calculated and compared with weekly data. We used annual BV and homeostatic set point to calculate personalized reference intervals (RIper) which were compared with population-based reference intervals (RIpop). RESULTS: We have established the annual within-subject BV (CVI), RCV, II, RIper of 24 commonly used clinical chemistry and hematology analytes for healthy individuals. Among the 18 comparable measurands, CVI estimates of annual data for 11 measurands were significantly higher than the weekly data. Approximately 50% measurands of II were <0.6, the utility of their RIpop were limited. The distribution range of RIper for most measurands only copied small part of RIpop with reference range index for 8 measurands <0.5. CONCLUSIONS: Compared with weekly BV, for annual healthcare individuals, annual BV and related parameters can provide more accurate evaluation of laboratory results. RIper based on long-term BV data is very valuable for "personalized" diagnosis on annual health assessments.

15.
Environ Int ; 158: 106965, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34735958

RESUMO

Trace elements have various physiochemical functions in humans and are associated with the occurrence of preterm birth (PB). However, their mixed effects on PB risk have rarely been studied. We aimed to investigate the associations between hair levels of trace elements and PB risk among pregnant women. A nested case-control study with a prospective cohort was conducted in Beijing City, China. We included 82 women who had a PB [total PB (tPB)] as cases [including 40 with a spontaneous PB (SPB)] and 415 who had a term delivery as controls. Hair levels of the concerned trace elements were measured including endocrine disrupting metal(loid)s [EDMs; lead, mercury (Hg), arsenic, and cadmium] and nutritional trace metal(loid)s [NTMs; zinc (Zn), iron (Fe), copper, and selenium]. Logistic regression analysis was performed to estimate the odds ratios (ORs) for PB. Bayesian kernel machine regression (BKMR) was used to assess the associations between mixed exposure to the trace elements and PB risk. Significantly lower maternal hair concentrations of Zn and Fe were observed in the SPB cases than in the controls, whereas no differences for the other trace elements. Single-element modeling results suggested second-quartile Hg maternal hair concentrations, third-quartile Zn concentrations, and fourth-quartile Fe concentrations were associated with a reduced risk of tPB with adjusted ORs of 0.43 [95% confidence interval (CI): 0.21-0.87], 0.38 (95% CI: 0.18-0.82), and 0.48 (95% CI: 0.24-0.98), respectively, compared to first-quartile values. Similar results were obtained for SPB. According to the BKMR models, hair NTMs were significantly, monotonously, and inversely associated with the risk of SPB, after controlling for covariates and levels of the four EDMs. Fe and Zn contributed the most strongly to the association. We concluded that maternal higher levels of NTMs, especially Fe and Zn, may reduce the risk of PB.

16.
Int J Mol Sci ; 22(21)2021 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-34768799

RESUMO

Serine/arginine-rich (SR) proteins are important splicing factors in plant development and abiotic/hormone-related stresses. However, evidence that SR proteins contribute to the process in woody plants has been lacking. Using phylogenetics, gene synteny, transgenic experiments, and RNA-seq analysis, we identified 24 PtSR genes and explored their evolution, expression, and function in Popolus trichocarpa. The PtSR genes were divided into six subfamilies, generated by at least two events of genome triplication and duplication. Notably, they were constitutively expressed in roots, stems, and leaves, demonstrating their fundamental role in P. trichocarpa. Additionally, most PtSR genes (~83%) responded to at least one stress (cold, drought, salt, SA, MeJA, or ABA), and, especially, cold stress induced a dramatic perturbation in the expression and/or alternative splicing (AS) of 18 PtSR genes (~75%). Evidentially, the overexpression of PtSCL30 in Arabidopsis decreased freezing tolerance, which probably resulted from AS changes of the genes (e.g., ICE2 and COR15A) critical for cold tolerance. Moreover, the transgenic plants were salt-hypersensitive at the germination stage. These indicate that PtSCL30 may act as a negative regulator under cold and salt stress. Altogether, this study sheds light on the evolution, expression, and AS of PtSR genes, and the functional mechanisms of PtSCL30 in woody plants.

17.
J Sep Sci ; 2021 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-34739178

RESUMO

The separation of compounds with similar polarities is challenging. In the present study, five flavone glycosides, including two groups with similar polarities, were obtained from Dracocephalum tanguticum by three high-speed counter-current chromatography modes, including flow rate conversion mode, recycling mode, and heart-cut mode. With flow rate conversion mode, compounds 3 and 4 with similar polarities and compound 5 were separated by high-speed counter-current chromatography with ethyl acetate/methanol/water (5.0% acetic acid) (8:2:10, v/v) system. The flow rate was controlled as: 1.8 mL/min for 0-160 min, 2.2 mL/min for 160-200 min, and 2.5 mL/min for 200-400 min. However, compounds 1 and 2 with similar polarities were not separated due to the similar distributive properties. Then, a recycling and heart-cut mode were introduced to improve the separation efficiency. The heart-cut mode was introduced in the second and third cycles, and compounds 1 and 2 were well separated in the fourth cycle. Consequently, five flavone glycosides, including two groups with similar polarities were obtained and identified as cosmosiin (1), pedaliin (2), quercetin-3-O-rutinoside (3), pedaliin-6''-acetate (4), and sorbifolin-6-O-ß-glucopyranoside (5). The current strategy provides a reference for separating compounds with similar polarities from a crude sample.

18.
Sci Total Environ ; : 151488, 2021 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-34742962

RESUMO

Maternal exposure to fine particulate matter (PM2.5) has been associated with increased risk of preterm birth (PTB), but evidence on particles in smaller sizes and PTB risk remains limited. In this retrospective analysis, we included birth records of 24,001 singleton live births from Haidian Maternal and Child Health Hospital in Beijing, China, 2014-2017. Concurrently, number concentrations of size-fractioned particles in size ranges of 5-560 nm (PNC5-560) and mass concentrations of PM2.5, black carbon (BC) and gaseous pollutants were measured from a fixed-location monitoring station in central Haidian District. Logistic regression models were used to estimate the odds ratio (OR) of air pollutants on PTB risk after controlling for temperature, relative humidity, and individual covariates (e.g., maternal age, ethnicity, gravidity, parity, gestational weight gain, fetal gender, the year and season of conception). Positive matrix factorization models were then used to apportion the sources of PNC5-560. Among the 1062 (4.4%) PTBs, increased PTB risk was observed during the third trimester of pregnancy per 10 µg/m3 increase in PM2.5 [OR = 1.92; 95% Confidence Interval (95% CI): 1.76, 2.09], per 1000 particles/cm3 increase in PNC25-100 (OR = 1.09; 95% CI: 1.03, 1.15) and PNC100-560 (OR = 1.22; 95% CI: 1.05, 1.42). Among the identified sources of PNC5-560, emissions from gasoline and diesel vehicles were significantly associated with increased PTB risk, with ORs of 1.14 (95% CI: 1.01, 1.29) and 1.11 (95% CI: 1.04, 1.18), respectively. Exposures to other traffic-related air pollutants, such as BC and nitrogen dioxide (NO2) were also significantly associated with increased PTB risk. Our findings highlight the importance of traffic emission reduction in urban areas.

19.
Phys Rev Lett ; 127(16): 168001, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34723584

RESUMO

We study experimentally the effect of added salt in the phoretic motion of chemically driven colloidal particles. We show that the response of passive colloids to a fixed active colloid, be it attractive or repulsive, depends on the ionic strength, the ζ potential, and the size of the passive colloids. We further report that the direction of self-propulsion of Janus colloids can be reversed by decreasing their ζ potential below a critical value. By constructing an effective model that treats the colloid and ions as a whole subjected to the concentration field of generated ions and takes into account the joint effect of both generated and background ions in determining the Debye length, we demonstrate that the response of the passive colloids and the velocity of the Janus colloids can be quantitatively captured by this model under the ionic diffusiophoresis theory beyond the infinitely-thin-double-layer limit.

20.
Mol Ther Nucleic Acids ; 26: 927-944, 2021 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-34760337

RESUMO

The circRNAs, a new subclass of non-coding RNAs that are catalyzed by RNA-binding proteins (RBPs), have been reported to be associated with the progression of multiple types of cancer. We previously discovered that heterogeneous nuclear ribonucleoprotein L (HnRNP-L), a multi-functional RBP, is associated with pro-proliferation and anti-apoptosis activities in prostate tumor cells. In this study, we aim to establish the biological relevance of circCSPP1 (a newly discovered signature circRNA in prostate cancer [PCa]) and HnRNP-L to prostate cancer progression. First, we demonstrated that circCSPP1 expression was higher in prostate cancer tissues than in benign tissues and higher in prostate cancer cells than in benign cells. Then, the in vitro gain- and loss-of-function experiments showed that the circCSPP1 expression in prostate cancer cells was regulated by HnRNP-L, and the increased circCSPP1 significantly induced autophagy, which led to an enhanced potential in proliferation, migration, and invasion of prostate cancer cells. These results were consistent with the in vivo experiment where increased or decreased circCSPP1 was associated with higher or slower growth rate in grafted tumors. Finally, we demonstrated the potential competing endogenous RNA network, involving circCSPP1, miR-520h, and early growth response factor 1 (EGR1), in prostate cancer cells, which may play an important role in prostate cancer progression. Our study indicated that the increase in circCSPP1 in prostate cancer, which may be catalyzed by HnRNP-L, can induce cellular autophagy through the circCSPP1-miR-520h-EGR1 axis, leading to the progression of prostate tumor. This newly discovered circRNA biomarker may be used for clinical prognosis of prostate cancer as well as for development of novel therapy plans.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...