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1.
Sci Total Environ ; 923: 171417, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38447725

RESUMO

The water-level fluctuations zones (WLFZs) are crucial transitional interfaces within river-reservoir systems, serving as hotspots for N2O emission. However, the comprehension of response patterns and mechanisms governing N2O emission under hydrological fluctuation remains limited, especially in karstic canyon reservoirs, which introduces significant uncertainty to N2O flux assessments. Soil samples were collected from the WLFZs of the Hongjiadu (HJD) Reservoir along the water flow direction from transition zone (T1 and T2) to lacustrine zone (T3, T4 and T5) at three elevations for each site. These soil columns were used to conduct simulation experiments under various water-filled pore space gradients (WFPSs) to investigate the potential N2O flux pattern and elucidate the underlying mechanism. Our results showed that nutrient distribution and N2O flux pattern differed significantly between two zones, with the highest N2O fluxes in the transition zone sites and lacustrine zone sites were found at 75 % and 95 % WFPS, respectively. Soil nutrient loss in lower elevation areas is influenced by prolonged impoundment durations. The higher N2O fluxes in the lacustrine zone can be attributed to increased nutrient levels resulting from anthropogenic activities. Furthermore, correlation analysis revealed that soil bulk density significantly impacted N2O fluxes across all sites, while NO3-and SOC facilitated N2O emissions in T1-T2 and T4-T5, respectively. It was evident that N2O production primarily contributed to nitrification in the transition zone and was constrained by the mineralization process, whereas denitrification dominated in the lacustrine zone. Notably, the annual N2O efflux from WLFZs accounted for 27 % of that from the water-air interface in HJD Reservoir, indicating a considerably lower contribution than anticipated. Nevertheless, this study highlights the significance of WLFZs as a vital potential source of N2O emission, particularly under the influence of anthropogenic activities and high WFPS gradient.

2.
Sci Total Environ ; 919: 170912, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38354794

RESUMO

Agricultural ditches are significant methane (CH4) sources since substantial nutrient inputs stimulate CH4 production and emission. However, few studies have quantified the role of diffusion and ebullition pathways in total CH4 emission from agricultural ditches. This study measured the spatiotemporal variations of diffusive and ebullitive CH4 fluxes from a multi-level ditch system in a typical temperate agriculture area, and assessed their contributions to the total CH4 emission. Results illustrated that the mean annual CH4 flux in the ditch system reached 1475.1 mg m-2 d-1, among which 1376.7 mg m-2 d-1 was emitted via diffusion and 98.5 mg m-2 d-1 via ebullition. Both diffusive and ebullitive fluxes varied significantly across different types of ditches and seasons, with diffusion dominating CH4 emission in middle-size ditches and ebullition dominating in large-size ditches. Diffusion was primarily driven by large nutrient inputs from adjacent farmlands, while hydrological factors like water temperature and depth controlled ebullition. Overall, CH4 emission accounted for 86 % of the global warming potential across the ditch system, with 81 % attributed to diffusion and 5 % to ebullition. This study highlights the importance of agricultural ditches as hotspots for CH4 emissions, particularly the dominant role of the diffusion pathway.

3.
Bioresour Technol ; 395: 130399, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38286165

RESUMO

The utilization of biomass char was hindered by the low gasification activity due to thick ring structures and unclear gasification mechanism. Herein, the mechanism was elucidated by experimental and DFT to improve the activity. The results demonstrated that temperature increased the gasification activity but did not changed the order of gasification activity of samples. Pressure dominated the position of the highest point of instantaneous CH4 yield, and high pressure enhanced carbon conversion by 81.72 % and 7.32 times. Moreover, KNi exhibited an uppermost catalytic activity with the instantaneous CH4 yield 1.89 times higher than that of raw char at 750 °C. The formation of the CxNi structure lowered the activation barrier for the ring opening reaction. Possible transformation pathways of Ni species were as follows: Ni(NO3)2·6H2O â†’ NiO â†’ Ni. KNi changed the reaction pathways and the most energy-consuming step. The study could shed light on the hydrogasification reaction mechanism.


Assuntos
Dióxido de Carbono , Elementos de Transição , Dióxido de Carbono/química , Carbono , Temperatura , Catálise , Biomassa
4.
Int J Biol Macromol ; 252: 126093, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-37573910

RESUMO

Inspired by recent advances on functional modification of cellulosic materials, the crosslinking behaviors of epoxide with cellulose under the catalysis of different homogeneous catalysts including H2O, Brønsted acid, Brønsted base, Lewis acid and neutral salt were systematically investigated using density functional theory (DFT) methods with hybrid micro-solvation-continuum approach. The results showed that catalytic activity, reaction mechanism and regioselectivity are determined by the combined effect of catalyst type, electronic effect and steric hindrance. All the homogeneous catalysts have catalytic activity for the crosslinking reaction, which decreases in the order of NaOH > HCl > NCl3 > MCl2 > CH3COOH > NaCl (N = Fe3+, Al3+; M = Zn2+, Ca2+). Upon the catalysis of NaOH, hydroxyl group of cellulose is firstly deprotonated to form a carbanion-like intermediate which will further attack the less sterically hindered C atom of epoxide showing excellent regioselectivity. Acidic catalysts readily cause epoxide protonated, which suffers from nucleophilic attack of cellulose and forms the carbocation-like intermediate. Brønsted acid exhibits poor regioselectivity, however, Lewis acid shows an interesting balance between catalytic activity and regioselectivity for the crosslinking reaction, which may be attributed to the unique catalysis and stabilization effects of its coordinated H2O on the transition state structure.


Assuntos
Celulose , Compostos de Epóxi , Compostos de Epóxi/química , Solventes/química , Hidróxido de Sódio , Catálise , Ácidos de Lewis
5.
Water Res ; 242: 120271, 2023 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-37399689

RESUMO

Agricultural ditches are pervasive in agricultural areas and are potential greenhouse gas (GHG) hotspots, since they directly receive abundant nutrients from neighboring farmlands. However, few studies measure GHG concentrations or fluxes in this particular water course, likely resulting in underestimations of GHG emissions from agricultural regions. Here we conducted a one-year field study to investigate the GHG concentrations and fluxes from typical agricultural ditch systems, which included four different types of ditches in an irrigation district located in the North China Plain. The results showed that almost all the ditches were large GHG sources. The mean fluxes were 333 µmol m-2 h-1 for CH4, 7.1 mmol m-2 h-1 for CO2, and 2.4 µmol m-2 h-1 for N2O, which were approximately 12, 5, and 2 times higher, respectively, than that in the river connecting to the ditch systems. Nutrient input was the primary driver stimulating GHG production and emissions, resulting in GHG concentrations and fluxes increasing from the river to ditches adjacent to farmlands, which potentially received more nutrients. Nevertheless, the ditches directly connected to farmlands showed lower GHG concentrations and fluxes compared to the ditches adjacent to farmlands, possibly due to seasonal dryness and occasional drainage. All the ditches covered approximately 3.3% of the 312 km2 farmland area in the study district, and the total GHG emission from the ditches in this area was estimated to be 26.6 Gg CO2-eq yr-1, with 17.5 Gg CO2, 0.27 Gg CH4, and 0.006 Gg N2O emitted annually. Overall, this study demonstrated that agricultural ditches were hotspots of GHG emissions, and future GHG estimations should incorporate this ubiquitous but underrepresented water course.


Assuntos
Gases de Efeito Estufa , Gases de Efeito Estufa/análise , Dióxido de Carbono , Metano/análise , Óxido Nitroso/análise , Água , Efeito Estufa
6.
J Mater Chem B ; 11(27): 6372-6382, 2023 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-37334568

RESUMO

Although NIR-II laser-mediated photothermal therapy (PTT) is considered as an emerging strategy for tumor therapy, its therapeutic effects are still seriously hampered by low photothermal conversion efficacy, limited tissue penetration depth, and inevitable damage to adjoining healthy tissues. Herein, we report a mild second-near-infrared (NIR-II) photothermal-augmented nanocatalytic therapy (NCT) nanoplatform based on CD@Co3O4 heterojunctions by depositing NIR-II-responsive carbon dots (CDs) onto the surface of Co3O4 nanozymes. The as-prepared Co3O4 nanozymes possess multi-enzyme-mimicking catalytic activity including peroxidase, catalase, and glutathione-peroxidase to realize the cascade amplification of ROS levels owing to the presence of multivalent Co2+ and Co3+. CDs with a high NIR-II photothermal conversion efficiency (PCE) (51.1%) enable the realization of mild PTT (∼43 °C), which could not only avoid damage to adjoining healthy tissues but also enhance the multi-enzyme-mimic catalytic activity of Co3O4 nanozymes. More importantly, the NIR-II photothermal properties of CDs and the multi-enzyme-mimicking catalytic activity of Co3O4 nanozymes are greatly augmented by the fabrication of heterojunctions due to the induced localized surface plasmonic resonance (LSPR) and accelerated carrier transfer. On the basis of these advantages, satisfactory mild PTT-amplified NCT is accomplished. Our work presents a promising approach for mild NIR-II photothermal-amplified NCT based on semiconductor heterojunctions.


Assuntos
Carbono , Terapia Fototérmica , Linhagem Celular Tumoral , Peroxidases
7.
Sci Total Environ ; 895: 165099, 2023 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-37379928

RESUMO

Forest soils cover about 30 % of the Earth's land surface and play a fundamental role in the global cycle of organic matter. Dissolved organic matter (DOM), the largest active pool of terrestrial carbon, is essential for soil development, microbial metabolism and nutrient cycling. However, forest soil DOM is a highly complex mixture of tens of thousands of individual compounds, which is largely composed of organic matter from primary producers, residues from microbial process and the corresponding chemical reactions. Therefore, we need a detailed picture of molecular composition in forest soil, especially the pattern of large-scale spatial distribution, which can help us understand the role of DOM in the carbon cycle. To explore the spatial and molecular variations of DOM in forest soil, we choose six major forest reserves located in different latitudes ranging in China, which were investigated by Fourier transform-ion cyclotron resonance mass spectrometry (FT-ICR MS). Results show that aromatic-like molecules are preferentially enriched in DOM at high latitude forest soils, while aliphatic/peptide-like, carbohydrate-like, and unsaturated hydrocarbon molecules are preferentially enriched in DOM at low latitude forest soils, besides, lignin-like compounds account for the highest proportion in all forest soil DOM. High latitude forest soils have higher aromatic equivalents and aromatic indices than low latitude forest soils, which suggest that organic matter at higher latitude forest soils preferentially contain plant-derived ingredients and are refractory to degradation while microbially derived carbon is dominant in organic matter at low latitudes. Besides, we found that CHO and CHON compounds make up the majority in all forest soil samples. Finally, we visualized the complexity and diversity of soil organic matter molecules through network analysis. Our study provides a molecular-level understanding of forest soil organic matter at large scales, which may contribute to the conservation and utilization of forest resources.

8.
Environ Sci Technol ; 56(23): 17288-17297, 2022 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-36214751

RESUMO

Desulfurization sorbent with a high active component utilization is of importance for the removal of H2S from coal gas at high temperatures. Thus, the hypothesis for producing ZnxCo3-xO4/carbon nanofiber sorbents via the combinations of electrospinning, in situ hydrothermal growth, and carbonization technique has been rationally constructed in this study. ZnxCo3-xO4 nanoparticles derived from metal-organic frameworks are uniformly loaded on the electrospun carbon nanofibers (CNFs) with high dispersion. ZnxCo3-xO4/CNFs sorbents possess the highest breakthrough sulfur adsorption capacity (12.4 g S/100 g sorbent) and an excellent utilization rate of the active component (83.2%). The excellent performance of ZnxCo3-xO4/CNFs can be attributed to the synergetic effect of the hierarchical structure and widely distributed ZnxCo3-xO4 on the CNFs supporter. The decomposition of Zn/Co-ZIFs not only generates the nucleus of oxides but also realizes their physical isolation through the formation of carbon grids on the surface of CNFs, avoiding the aggregation of oxides. Furthermore, ZnxCo3-xO4/CNFs sorbents show an overwhelming superiority over the ZnO/CNFs sorbent, which is attributed to the introduction of Co and then the promotion of the stability of Zn at high temperatures. The presence of Co also accelerates the adsorption of H2S on the active site of the oxide surface. The presented method is beneficial for promoting desulfurization performances and producing sorbents with high utilization of active components.

9.
Diagn Pathol ; 17(1): 76, 2022 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-36199118

RESUMO

Skin metastasis of ovarian cancer is extremely rare. We report an unusual case of ovarian carcinosarcoma with cutaneous metastasis of carcinomatous component that displayed distinct clinical manifestation. A 48-year-old woman presented to the dermatologist complaining of a new onset of erythematous, plaque-like skin rash with multiple small nodules on the left inner thigh, the area measuring 8 × 5cm. While the patient had no history of dermatologic conditions, she underwent a total hysterectomy and bilateral salpingo-oophorectomy, omentectomy, and lymph node dissection 16 months ago with a pathology confirmed stage IIIC ovarian carcinosarcoma. Of note, the carcinomatous component, mainly adenocarcinoma with hybrid features of seromucinous, endometrioid and minor high-grade serous carcinoma, involved bilateral fallopian tubes, omentum, and parametrium with extensive lymph node metastases. A skin biopsy specimen revealed an adenocarcinoma involving epidermis, dermis, and subcutaneous tissue with nodular contours, consistent with metastatic carcinomatous component of carcinosarcoma. Both carcinomatous component of primary ovarian carcinosarcoma and metastatic adenocarcinoma in the skin demonstrated Pax8, WT-1, and ER positivity and a mutation pattern of p53. The patient passed away 15 months after identification of skin metastasis. This case represents a unique example of cutaneous metastasis of ovarian carcinosarcoma with distinct clinical manifestation and detailed histopathological description. Alertness to the possibility of cutaneous metastasis, in combination with clinical history, morphological and immunohistochemical findings, is critical for a definitive classification.


Assuntos
Adenocarcinoma , Carcinossarcoma , Neoplasias Ovarianas , Neoplasias Cutâneas , Carcinossarcoma/patologia , Feminino , Humanos , Pessoa de Meia-Idade , Neoplasias Ovarianas/patologia , Neoplasias Cutâneas/patologia , Proteína Supressora de Tumor p53
10.
Onco Targets Ther ; 15: 973-979, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36118677

RESUMO

Background: The mortality rate of ovarian cancer (OC) ranks first among female genital tract malignant tumors, which seriously threatens women's life and health. Because of its insidious onset and poor prognosis, it has become a thorny problem in the clinic, especially for patients with platinum-resistant recurrent ovarian cancer (PROC). In recent years, the medical treatment of OC has made gratifying results, bringing hope to the patients. Case Description: A 54-year-old OC patient who has failed previous neoadjuvant chemotherapy, cytoreductive surgery, and postoperative chemotherapy was diagnosed with PROC. Then she received combination treatment of fuzuloparib (100mg PO BID), apatinib (250mg PO QD), and camrelizumab (200mg IV Q3W) for every 3-week cycle in a Phase II study for PROC patients. In the phase II study, her condition stabilized, responded well to treatment with a sharp decrease by 91.14% of target lesions and disappearances of non-target lesions, and continued to receive regular treatment with progression-free survival exceeding 15 months and no serious adverse events. Conclusion: The present case proves PROC patients might have a sustained response to triplet combination with camrelizumab, combined with fuzuloparib and apatinib.

11.
Front Oncol ; 12: 875033, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35600335

RESUMO

The growth of lymphatic vessels (lymphangiogenesis) plays a pivotal role in breast cancer progression and metastasis and the immune response. Vascular endothelial growth factor C (VEGFC) has been demonstrated to accelerate cancer metastasis and modulate the immune system by enhancing lymphangiogenesis. However, it remains largely unclear how transcription factors physically regulate VEGFC expression by interacting with histone-modifying enzymes. Like many histone-modifying enzymes, SETD7 plays a key role in cell proliferation and inhibits tumour cell differentiation. In this study, we identified the role of the transcription factor zinc finger with KRAB and SCAN domains 5 (ZKSCAN5) in interacting with histone methyltransferase SETD7 and mediating VEGFC transcription and tumour lymphangiogenesis. ZKSCAN5 interacts with and recruits SETD7 to the VEGFC promoter. By regulating breast cancer-secreted VEGFC, ZKSCAN5 could induce the tube formation of lymph endothelial cells, which promotes tumour proliferation, migration, and metastasis. Clinically, the expression of ZKSCAN5 was frequently upregulated in patients with breast cancer and positively correlated with the expression of VEGFC and the number of lymphatic microvessels. ZKSCAN5 is a poor prognostic factor for patients with breast cancer. Our results characterise the role of ZKSCAN5 in regulating VEGFC transcription and predict ZKSCAN5 as a breast cancer therapeutic target.

12.
J Neurotrauma ; 39(5-6): 371-378, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35018830

RESUMO

Moderate traumatic brain injury (mTBI) is a heterogeneous entity that is poorly defined in the literature. Patients with mTBI have a high rate of neurological deterioration (ND), which is usually accompanied by poor prognosis and no definitive methods to predict. The purpose of this study is to develop and validate a prediction model that estimates the ND risk in patients with mTBI using data collected on admission. Data for 479 patients with mTBI collected retrospectively in our department were analyzed by logistic regression models. Bivariable logistic regression identified variables with a p < 0.05. Multi-variable logistic regression modeling with backward stepwise elimination was used to determine reduced parameters and establish a prediction model. The discrimination efficacy, calibration efficacy, and clinical utility of the prediction model were evaluated. The prediction model was validated using data for 176 patients collected from another hospital. Eight independent prognostic factors were identified: hypertension, Marshall scale (types III and IV), subdural hemorrhage (SDH), location of contusion (frontal and temporal contusions), Injury Severity Score >13, D-dimer level >11.4 mg/L, Glasgow Coma Scale score ≤10, and platelet count ≤152 × 109/L. A prediction model was established and was shown as a nomogram. Using bootstrapping, internal validation showed that the C-statistic of the prediction model was 0.881 (95% confidence interval [CI]: 0.849-0.909). The results of external validation showed that the nomogram could predict ND with an area under the curve of 0.827 (95% CI: 0.763-0.880). The present model, based on simple parameters collected on admission, can predict the risk of ND in patients with mTBI accurately. The high discriminative ability indicates the potential of this model for classifying patients with mTBI according to ND risk.


Assuntos
Lesões Encefálicas Traumáticas , Lesões Encefálicas Traumáticas/complicações , Lesões Encefálicas Traumáticas/diagnóstico , Escala de Coma de Glasgow , Humanos , Modelos Logísticos , Prognóstico , Estudos Retrospectivos
13.
Genes Genomics ; 44(4): 455-465, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-34860317

RESUMO

BACKGROUND: Tripartite Motif Containing 3 (TRIM3) has been reported to be downregulated in several malignancies. However, its prognostic significance in thyroid cancer remains unknown. OBJECTIVE: Here we aimed to investigate TRIM3's expression and its involvement in papillary thyroid carcinoma (PTC). METHODS: Clinicopathological analyses were performed in patients with PTC. Expression of TRIM3 protein was evaluated by IHC. The prognostic role of TRIM3 in PTC patients was assessed by univariate and multivariate analyses. Cell proliferation and invasion were tested in two PTC cell lines following overexpression or knockdown. RESULTS: TRIM3 was decreased in PTC tissues compared to adjacent thyroid tissues on both mRNA and protein levels. Additionally, low expression of TRIM3 was significantly related to tumor size, lymph node metastasis and TNM stage. Moreover, TRIM3 was identified as an independent prognosis factor by multivariate analysis. Cellular data revealed that TRIM3 can inhibit the proliferation and invasion of PTC cells. Consistently, TRIM3 can upregulate the expression level of E-cadherin, while downregulate N-cadherin, Vimentin, and cyclin D1 expression. CONCLUSIONS: TRIM3 expression was downregulated in PTC tissues comparing with that in adjacent nontumorous thyroid tissues. Lower TRIM3 expression in PTC can contribute independently to a poorer prognosis by enhancing PTC proliferation and invasion, highlighting its potential as a novel therapeutic target and prognostic biomarker.


Assuntos
Neoplasias da Glândula Tireoide , Proliferação de Células/genética , Humanos , Prognóstico , Câncer Papilífero da Tireoide/genética , Câncer Papilífero da Tireoide/metabolismo , Câncer Papilífero da Tireoide/patologia , Neoplasias da Glândula Tireoide/genética , Neoplasias da Glândula Tireoide/metabolismo , Neoplasias da Glândula Tireoide/patologia
14.
Front Microbiol ; 13: 1110151, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36713174

RESUMO

Biogenic nitrous oxide (N2O) from nitrification and denitrification in agricultural soils is a major source of N2O in the atmosphere, and its flux changes significantly with soil moisture condition. However, the quantitative relationship between N2O production from different pathways (i.e., nitrification vs. denitrification) and soil moisture content remains elusive, limiting our ability of predicting future agricultural N2O emissions under changing environment. This study quantified N2O production rates from nitrification and denitrification under various soil moisture conditions using laboratory incubation combined with literature synthesis. 15N labeling approach was used to differentiate the N2O production from nitrification and denitrification under eight different soil moisture contents ranging from 40 to 120% water-filled pore space (WFPS) in the laboratory study, while 80 groups of data from 17 studies across global agricultural soils were collected in the literature synthesis. Results showed that as soil moisture increased, N2O production rates of nitrification and denitrification first increased and then decreased, with the peak rates occurring between 80 and 95% WFPS. By contrast, the dominant N2O production pathway switched from nitrification to denitrification between 60 and 70% WFPS. Furthermore, the synthetic data elucidated that moisture content was the major driver controlling the relative contributions of nitrification and denitrification to N2O production, while NH4 + and NO3 - concentrations mainly determined the N2O production rates from each pathway. The moisture treatments with broad contents and narrow gradient were required to capture the comprehensive response of soil N2O production rate to moisture change, and the response is essential for accurately predicting N2O emission from agricultural soils under climate change scenarios.

15.
Se Pu ; 39(6): 599-606, 2021 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-34227320

RESUMO

Panax ginseng has a 5000-year-long history as a traditional herbal medicine in Eastern Asia and North America. It is also known as crown jewel in traditional Chinese herbs because of its wide pharmacological properties. Ginsenosides, a class of saponins containing triterpene aglycones and various sugar moieties, are the main active components of ginseng. Considering the low abundance of ginsenosides and other abundant interferences, separation of ginsenosides is essential prior to further analysis. Recently, our group demonstrated the potential of a boronate affinity material for the selective enrichment of ginsenosides. However, conventional boronate affinity materials suffer from an apparent drawback. The binding strength of boronic acids toward cis-diol-containing compounds is low, with dissociation constants (Kd) ranging from 10-1 to 10-3mol/L. Thus, it is necessary to develop boronate affinity materials with high binding strength. In this study, we developed polyethyleneimine (PEI)-functionalized boronate affinity magnetic nanoparticles (BA-MNPs) for the selective enrichment of ginsenosides. Branched PEI was applied as a scaffold to amplify the number of boronic acid moieties, while 3-formylphenylboronic acid, which shows high affinity toward cis-diol-containing molecules, was used as the affinity ligand. In addition, the presence of the multi-glycan structure of ginsenoside leads to higher binding affinity between the PEI-BA-MNPs due to the synergistic multivalent binding effect. Combining with high performance liquid chromatography, a method for the selective analysis of ginsenosides was established. With ginsenoside Re as the representative and under the optimized conditions for magnetic solid-phase extraction, the developed method showed good linearity in the range of 50-800 µg/L, with a linear correlation coefficient (R2) of 0.9681. At different spiked levels (0.1-10 mg/L), the recoveries were in the range of 91.5%-117.3%, and the relative standard deviations (RSDs) ranged from 7.2% to 13.4%. Since the PEI-BA-MNPs exhibited significantly improved binding strength toward ginsenosides, they could extract trace glycoproteins. After enrichment, a 50-fold improvement in the sensitivity was achieved. In addition, the PEI-BA-MNPs maintained at least 72% of their original binding capacity after five consecutive uses. Finally, the developed method was applied to the determination of ginsenoside Re in commercial medicine (Qipi oral liquid). As opposed to the tedious and time-consuming sample preparation in the standard method (Pharmacopoeia of the People's Republic of China, 2015; ChP2015), the present protocol allowed for direct enrichment of the diluted commercial medicine with PEI-BA-MNPs. The magnetic separation made the overall experiment much simpler than the standard ChP2015 method. After washing and elution, the enriched ginsenoside Re was eluted and subjected to HPLC-UV analysis. The results obtained with the developed method (0.27%) were similar to those of ChP2015 (0.31%). We have experimentally demonstrated that PEI-BA-MNPs are ideal affinity sorbents for the selective enrichment of ginsenosides owing to their significant advantages, including high affinity, excellent selectivity, easy manipulation, high binding capacity, and fast binding equilibrium. As many saponins contain sugar side chains, we foresee a promising prospect for the proposed method in real-world applications.


Assuntos
Ácidos Bóricos/química , Ginsenosídeos , Nanopartículas de Magnetita , Polietilenoimina/química , China , Cromatografia Líquida de Alta Pressão , Ginsenosídeos/isolamento & purificação , Panax
16.
Materials (Basel) ; 14(9)2021 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-33925524

RESUMO

AZ31B magnesium alloy is the experimental material in this study. Considering its anisotropy, fatigue assessment based on self-heating is carried out for both the extrusion direction and the transverse direction. The self-heating behavior in the two orientations is compared. Similar to steels, an obvious inflection point that corresponds to the fatigue limit can be found in the self-heating vs. load curve for AZ31B. A new fatigue limit assessment method is proposed based on a statistical analysis of self-heating data. This method can provide a satisfactory assessment of the fatigue limit for AZ31B in the both orientations.

17.
J Cancer Res Clin Oncol ; 147(6): 1713-1723, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33651140

RESUMO

BACKGROUND: Gliomas are highly aggressive and lack of efficient targeted therapy. YAP, as a Hippo pathway downstream effector, plays a key role in promoting tumor development through the interaction with transcription factor TEAD on the NH3-terminal proline-rich domain. Therefore, targeting TEAD-interacting domain of YAP may provide a novel approach for the treatment of gliomas. MATERIALS AND METHODS: We generated a truncated YAP protein which includes the TEAD-binding domain (YAPBD), and supposed YAPBD can interact with endogenous TEAD but lost the function to activate YAP target gene expressions. The association of YAP expression with the malignant characters of glioma tissues were determined by immunohistochemistry. TEAD-binding capacity of YAPBD was determined by co-immunoprecipitation. The cell proliferation and migration were determined by MTT assay, xenograft assay, wound healing assay and transwell assay, respectively. YAP target genes were detected by Western blot. RESULTS: YAP was highly expressed in glioma tissues and associated with tumor malignancy. YAPBD could block the TEAD-YAP complex formation by competing with YAP binding to TEAD. YAPBD could inhibit glioma cell growth both in vitro and in vivo, through the induction of cell cycle arrest and apoptosis. The cell cycle-related gene cyclin D1 and c-myc, and anti-apoptotic gene Bcl-2, Bcl-xL and survivin were inhibited after YAPBD overexpression. Furthermore, YAPBD also decreased cell migration and invasion, and repressed epithelial-mesenchymal transition. CONCLUSION: YAPBD can block glioma cell survival and repress YAP-dependent gene expressions, indicating gene therapy which targets TEAD-YAP complex would be a potential and significant novel approach for human malignant gliomas.


Assuntos
Proteínas de Ciclo Celular/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Neoplasias do Sistema Nervoso Central/patologia , Glioma/patologia , Proteínas Recombinantes/farmacologia , Fatores de Transcrição/farmacologia , Animais , Ligação Competitiva , Proteínas de Ciclo Celular/química , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Neoplasias do Sistema Nervoso Central/diagnóstico , Neoplasias do Sistema Nervoso Central/genética , Códon sem Sentido/genética , Estudos de Coortes , Proteínas de Ligação a DNA/metabolismo , Regulação Neoplásica da Expressão Gênica , Glioma/diagnóstico , Glioma/genética , Humanos , Camundongos , Camundongos Nus , Proteínas Nucleares/metabolismo , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas/genética , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Fatores de Transcrição de Domínio TEA , Fatores de Transcrição/química , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto
18.
RSC Adv ; 11(15): 8775-8781, 2021 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-35423405

RESUMO

Saponin is a large family of important natural products with various pharmacological activities. Selective enrichment of saponin from complex biological samples is a key step for analysis of saponin. Despite that aptamers have been widely used for selective enrichment, aptamers that can specifically recognize saponins have never been reported. In this study, a facile and efficient SELEX approach was developed for in vitro evolution of saponin-binding aptamers, using PEI-assisted boronate affinity magnetic nanoparticles (p-BA-MNPs) that exhibit highly favorable binding properties as a general affinity platform. As a proof of the principle, ginsenoside Re and Rb1 were employed as two target saponins. Two aptamers towards each target saponin, with dissociation constant at the 10-5 M level, were selected within 6 rounds. An affinity magnetic nanoparticle was constructed by using the selected aptamer as a affinity ligand. The resulting material allowed for the quantitative analysis of ginsenoside Re in real samples with high reliability. The p-BA-MNPs based SELEX is straightforward and generally applicable for a wide range of target saponins, providing a promising aptamer evolution approach for aptamer-based research and pharmaceutical analysis.

19.
Sci Total Environ ; 759: 143471, 2021 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-33213905

RESUMO

Hydrological variations have substantial effects on the diversity and composition of soil bacterial communities in wetlands. At the spatial scale, the responses of soil bacterial diversity and composition to hydrological variations in wetlands have been extensively investigated. However, at the temporal scale, especially at the inter-annual scale, the corresponding bacterial responses are rarely reported. Therefore, we explored the effects of flooding variations on the diversity and composition of soil bacterial communities at a lakeshore wetland in two hydrological contrasting years. Three flooding variables, i.e. flooding duration (FD), total duration of the growing season (TGD), and exposure duration of the growing season (EGD), were used to characterize flooding regime. Soil bacterial communities were determined using 16S rRNA gene sequencing method. We found a very high soil bacterial diversity at the lakeshore wetland. The Shannon's indexes of soil bacterial communities varied from 5.61 to 7.11 in two years. Soil bacterial α-diversity followed a unimodal curve along the elevation gradient, and was significantly lower in the flooding year than in the drought year. Principal coordinate analysis demonstrated that the compositions of soil bacterial communities were separated in order of elevation and year along the first and second axes, respectively. The apparent habitat preferences of soil bacterial families were closely connected with their respiratory traits, and this trend was stronger at the inter-annual scale than at the spatial scale. Soil bacterial compositions were predominantly determined by the direct (by changing respiratory traits) and indirect (by changing soil pH) effects of TGD at the spatial scale, while they were simultaneously regulated by the direct effects of three flooding variables at the inter-annual scale. Our results enhance the understanding of soil microbial communities in wetlands and have large implications for developing general theories to predicting soil microbial functions.


Assuntos
Solo , Áreas Alagadas , Bactérias/genética , Humanos , RNA Ribossômico 16S/genética , Microbiologia do Solo
20.
Materials (Basel) ; 13(22)2020 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-33218031

RESUMO

In this paper, infrared thermography was employed to study the fatigue process of AZ31B magnesium alloy. In order to eliminate the interference caused by the temperature rise of the fixture, a data processing method was proposed, which is based on a special model to describe the temperature change of the specimen. Based on the temperature data after processing, the temperature evolution indicates that AZ31B magnesium alloy has undergone cyclic hardening during fatigue. Three different temperature indicators were selected to evaluate the fatigue limit based on the evolution curve after processing. In addition, the experimental results showed that the temperature data processed by the proposed method can be used to estimate the fatigue limit of AZ31B magnesium alloy. Experiments were performed for both extrusion and transverse directions in consideration of the anisotropy of the AZ31B.

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