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1.
Environ Pollut ; 347: 123501, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38346640

RESUMO

Four different methods were used to identify the important factors influencing chlorophyll-a (Chl-a) content: correlation analysis (CC-NMI), principal component analysis (PCA), decision tree (DT), and random forest recursive feature elimination (RF-RFE). Considering the relationship between Chl-a and its active and passive factors, we established machine learning combination models based on multiple linear regression (MLR), multi-layer perceptron (MLP), and support vector regression (SVR) to predict Chl-a content for Poyang Lake, China. Then, the predictive effects of different combination models were compared and evaluated from multiple perspectives. Considering the actual needs for eutrophication prevention and control, the concept of risk probability was then introduced to assess the risk degree of risk associated with water blooms in Poyang Lake. The results indicated that the mean R2 for the Chl-a predictions using the MLR, MLP, and SVR models was 0.21, 0.61, and 0.75, respectively. Consequently, the SVR model demonstrated higher precision and more accurate predictions. Compared to other methods, integrating the SVR model with the RF-RFE method significantly improved the prediction accuracy, with the R2 increasing to 0.94. For Poyang Lake, 8.8% of random samples indicated a low risk level with a water bloom probability of 21.1%-36.5%; one sample indicated a medium risk level with a risk probability of 45.5%. The research results offer valuable insights for predicting eutrophication and conducting risk assessments for Poyang Lake. They also provide reliable scientific support for making decisions about eutrophication in lakes and reservoirs. Therefore, the results hold significant theoretical importance, practical value, and potential for widespread application.


Assuntos
Monitoramento Ambiental , Lagos , Clorofila A/análise , Lagos/análise , Monitoramento Ambiental/métodos , Água/análise , China , Eutrofização , Aprendizado de Máquina , Medição de Risco , Clorofila/análise
2.
Int J Biol Macromol ; 261(Pt 2): 129829, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38296134

RESUMO

Three-dimensional interpenetrating and hierarchically porous carbon material is an efficient catalyst support in water remediation and it is still a daunting challenge to establish the relationship between hierarchically porous structure and catalytic degradation performance. Herein, a highly porous silica (SiO2)/cellulose-based carbon aerogel with iron-based catalyst (FexOy) was fabricated by in-situ synthesis, freeze-drying and pyrolysis, where the addition of SiO2 induced the hierarchically porous morphology and three-dimensional interpenetrating sheet-like network with nitrogen doping. The destruction of cellulose crystalline structure by SiO2 and the iron-catalyzed breakdown of glycosidic bonds synergistically facilitated the formation of electron-rich graphite-like carbon skeleton. The unique microstructure is confirmed to be favorable for the diffusion of reactants and electron transport during catalytic process, thus boosting the catalytic degradation performance of carbon aerogels. As a result, the catalytic degradation efficiency of tetracycline under light irradiation by adding only 5 mg of FexOy/SiO2 cellulose carbon aerogels was as high as 90 % within 60 min, demonstrating the synergistic effect of photocatalysis and Fenton reaction. This ingenious structure design provides new insight into the relationship between hierarchically porous structure of carbon aerogels and their catalytic degradation performance, and opens a new avenue to develop cellulose-based carbon aerogel catalysts with efficient catalytic performance.


Assuntos
Carbono , Compostos Heterocíclicos , Carbono/química , Ferro/química , Dióxido de Silício , Celulose/química , Porosidade , Tetraciclina/química , Antibacterianos , Catálise
3.
Ren Fail ; 45(2): 2279647, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37964563

RESUMO

PURPOSE: Since previous studies have shown a paradoxical relationship between acute kidney injury (AKI) and risk of cognitive impairment, there is an urgent need for a meta-analysis to assess the relationship between AKI and risk of cognitive impairment or dementia. MATERIALS AND METHODS: From database inception to October 2023, we searched PubMed, OVID (Medline), Embase, Web of Science, and Cochrane Library. This study examined AKI and cognitive impairment or dementia observational studies. Two authors independently assessed cohort and cross-sectional study quality using the Newcastle-Ottawa Scale and AHRQ Scale. They also used ROBINS-I to assess bias. The meta-analysis used fixed effects. Sensitivity analysis verified results stability. The funnel plot, Egger test, and Begg test determined publication bias in the results. RESULTS: Seven studies with 423,876 patients were included in the meta-analysis. Patients with AKI were at higher risk of cognitive impairment or dementia compared to those who had not experienced AKI (OR = 1.87, 95% confidence interval [CI]: 1.77-1.98, I2=46.0%, p = 0.08). All subgroups showed a substantial connection between AKI and cognitive impairment. Compared to domestic research, the connection was stronger in overseas studies (OR = 2.18, 95% CI: 1.66-2.87). Both cognitive impairment and dementia outcomes showed a substantial connection between AKI and cognitive impairment, with OR values of 2.00 (95% CI: 1.44-2.76) and 2.04 (95% CI: 1.66-2.51). CONCLUSIONS: We found that AKI significantly increases cognitive impairment or dementia risk. Thus, early interventions to delay cognitive impairment and prevent adverse outcomes in AKI patients are needed.


Assuntos
Injúria Renal Aguda , Disfunção Cognitiva , Demência , Humanos , Demência/etiologia , Demência/complicações , Estudos Transversais , Disfunção Cognitiva/etiologia , Disfunção Cognitiva/complicações , Injúria Renal Aguda/etiologia , Injúria Renal Aguda/complicações , Estudos Observacionais como Assunto
4.
ACS Macro Lett ; 12(7): 880-887, 2023 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-37343235

RESUMO

Cellulose-based dielectrics with attractive dielectric performance are promising candidates to develop eco-friendly electrostatic energy storage devices. Herein, all-cellulose composite films with superior dielectric constant were fabricated by manipulating the dissolution temperature of native cellulose, where we revealed the relationship among the hierarchical microstructure of the crystalline structure, the hydrogen bonding network, the relaxation behavior at a molecular level, and the dielectric performance of the cellulose film. The coexistence of cellulose I and cellulose II led to a weakened hydrogen bonding network and unstable C6 conformations. The increased mobility of cellulose chains in the cellulose I-amorphous interphase enhanced the dielectric relaxation strength of side groups and localized main chains. As a result, the as-prepared all-cellulose composite films exhibited a fascinating dielectric constant of as high as 13.9 at 1000 Hz. This work proposed here provides a significant step toward fundamentally understanding the dielectric relaxation of cellulose, thus developing high-performance and eco-friendly cellulose-based film capacitors.

5.
ACS Appl Mater Interfaces ; 15(19): 23701-23710, 2023 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-37140941

RESUMO

Polypropylene (PP) serves as an excellent commercialized polymer dielectric film owing to its high breakdown strength, excellent self-healing ability, and flexibility. However, its low dielectric constant causes the large volume of the capacitor. Constructing multicomponent polypropylene-based all-organic polymer dielectric films is a facile strategy for achieving high energy density and efficiency simultaneously. Thereinto, the interfaces between the components become the key factors that determine the energy storage performance of the dielectric films. In this work, we propose to fabricate high-performance polyamide 513 (PA513)/PP all-organic polymer dielectric films via the construction of abundant well-aligned and isolated nanofibrillar interfaces. Laudably, a significant enhancement in the breakdown strength is achieved from 573.1 MV/m of pure PP to 692.3 MV/m with 5 wt % of PA513 nanofibrils. Besides, a maximum discharge energy density of about 4.4 J/cm2 is realized with 20 wt % of PA513 nanofibrils, which is about 1.6-folds higher than pure PP. Simultaneously, the energy efficiency of samples with modulated interfaces maintains higher than 80% up to 600 MV/m, which is much higher than pure PP of about 40.7% at 550 MV/m. This work provides a new strategy to fabricate high-performance multicomponent all-organic polymer dielectric films on an industrial scale.

6.
Aging (Albany NY) ; 15(10): 4051-4070, 2023 05 23.
Artigo em Inglês | MEDLINE | ID: mdl-37244287

RESUMO

BACKGROUND: Epigenetic regulations of immune responses are essential for cancer development and growth. As a critical step, comprehensive and rigorous explorations of m6A methylation are important to determine its prognostic significance, tumor microenvironment (TME) infiltration characteristics and underlying relationship with glioblastoma (GBM). METHODS: To evaluate m6A modification patterns in GBM, we conducted unsupervised clustering to determine the expression levels of GBM-related m6A regulatory factors and performed differential analysis to obtain m6A-related genes. Consistent clustering was used to generate m6A regulators cluster A and B. Machine learning algorithms were implemented for identifying TME features and predicting the response of GBM patients receiving immunotherapy. RESULTS: It is found that the m6A regulatory factor significantly regulates the mutation of GBM and TME. Based on Europe, America, and China data, we established m6Ascore through the m6A model. The model accurately predicted the results of 1206 GBM patients from the discovery cohort. Additionally, a high m6A score was associated with poor prognoses. Significant TME features were found among the different m6A score groups, which demonstrated positive correlations with biological functions (i.e., EMT2) and immune checkpoints. CONCLUSIONS: m6A modification was important to characterize the tumorigenesis and TME infiltration in GBM. The m6Ascore provided GBM patients with valuable and accurate prognosis and prediction of clinical response to various treatment modalities, which could be useful to guide patient treatments.


Assuntos
Glioblastoma , Humanos , Biologia Computacional , Glioblastoma/diagnóstico , Glioblastoma/terapia , Imunoterapia , Aprendizado de Máquina , Metilação , Prognóstico , Microambiente Tumoral/genética
7.
J Colloid Interface Sci ; 630(Pt A): 772-782, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36283265

RESUMO

Immobilizing catalyst system faces the challenge of balancing catalysts stability and exposure of active site in water treatment. In this study, a novel in-situ synthesis of monoclinic phase of titanium dioxide (TiO2(B)) in cellulose-derived carbon aerogel (TCA) is proposed for processing multi-task in water treatment. The homogeneous gelation reaction supported the high dispersion of TiO2(B) in carbon skeleton. Meanwhile, TiO2 acts as crosslinker to reinforce cellulose network, then the grain refinement of amorphous TiO2 is limited to obtain TiO2(B) during carbonization. Benefiting from the reinforced structure, TCA remains the porous structure after carbonization and exposes more adsorption site than carbon aerogel blended with anatase particles (ACA). The adsorption performance of TCA are 837.3 mg/g, 1156.2 mg/g and 512.6 mg/g on methylene blue, malachite green and crystal violet, respectively. Compared with ACA, the superior interaction between TiO2 and graphite-like carbon improves the degradation rate of tetracycline from 1.3 × 10-3 min-1 to 8.6 × 10-3 min-1, and maintains the degradation efficiency in 3 rounds cyclic test. Besides, TCA also exhibits nearly twice to ACA on absorption capacity of different oil. This facile in-situ synthesis method offers a new insight in fabricating carbon aerogel immobilized photocatalysts system for multi-task in water treatment.


Assuntos
Nanocompostos , Purificação da Água , Carbono , Titânio/química , Nanocompostos/química , Celulose/química , Catálise
8.
Carbohydr Polym ; 296: 119957, 2022 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-36087999

RESUMO

Hydrogel supported photocatalyst, an efficient strategy for water remediation suffers from compromised catalytic activity and insufficient stability. Herein, a robust cellulose-based composite hydrogel with zinc oxide (ZnO)/silica (SiO2) heterojunctions were fabricated by in-situ synthesis, where SiO2 not only acted as a cross-linking agent to enhance the mechanical strength and stability of hydrogel, but also promoted the photocatalytic properties of ZnO via transferring the electron-hole pairs due to its surface state. As a result, a significant improvement in the mechanical properties of cellulose-based composite hydrogel was achieved, exhibiting a high compressive strength of 703.4 kPa. Moreover, the degradation efficiency of methylene blue (MB) under light irradiation by cellulose-based composite hydrogel was 95 % in 120 min and the removal ratio maintained as high as 90 % after eight degradation cycles. This study provides a low-cost and facile method to construct new hydrogel supports with high stability and efficient photocatalytic properties.


Assuntos
Óxido de Zinco , Catálise , Celulose , Hidrogéis , Íons , Dióxido de Silício , Zinco
9.
Mol Ther Nucleic Acids ; 26: 1255-1269, 2021 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-34853725

RESUMO

Glioblastoma has been identified as the most common and aggressive primary brain tumor in adults. Recently, it has been found that cisplatin (DDP) treatment is a common chemotherapeutic method for GBM patients. circ_PTN (ID number: hsa_circ_0003949) is a newly found circular (circRNA) which has been proved to be highly expressed in GBM cells, while its role in GBM remains unclear. Therefore, our study focused on investigating the role of circ_PTN in the DDP resistance of GBM cells. The expression of circ_PTN in DDP-sensitive and DDP-resistant GBM cells was detected in our assay. Functional experiments were utilized to unveil the effects of circ_PTN on the DDP resistance of GBM cells. Moreover, mechanism assays were conducted to confirm the mechanism of how circ_PTN affected the DDP resistance of GBM cells. According to the results, we found that circ_PTN promoted the DDP resistance of GBM cells through activation of the PI3K/AKT pathway. Moreover, circ_PTN silencing inhibited the DDP resistance of GBM tumors in vivo. To conclude, our study unveiled the influence of circ_PTN on the DDP resistance of GBM cells, which might provide a therapeutic target for GBM treatment via DDP.

10.
Front Oncol ; 11: 676124, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34557404

RESUMO

The tumor microenvironment (TME) contributes to the initiation and progression of many neoplasms. However, the impact of low-grade glioma (LGG) purity on carcinogenesis remains to be elucidated. We selected 509 LGG patients with available genomic and clinical information from the TCGA database. The percentage of tumor infiltrating immune cells and the tumor purity of LGG were evaluated using the ESTIMATE and CIBERSORT algorithms. Stromal-related genes were screened through Cox regression, and protein-protein interaction analyses and survival-related genes were selected in 487 LGG patients from GEO database. Hub genes involved in LGG purity were then identified and functionally annotated using bioinformatics analyses. Prognostic implications were validated in 100 patients from an Asian real-world cohort. Elevated tumor purity burden, immune scores, and stromal scores were significantly associated with poor outcomes and increased grade in LGG patients from the TCGA cohort. In addition, CD3E was selected with the most significant prognostic value (Hazard Ratio=1.552, P<0.001). Differentially expressed genes screened according to CD3E expression were mainly involved in stromal related activities. Additionally, significantly increased CD3E expression was found in 100 LGG samples from the validation cohort compared with adjacent normal brain tissues. High CD3E expression could serve as an independent prognostic indicator for survival of LGG patients and promotes malignant cellular biological behaviors of LGG. In conclusion, tumor purity has a considerable impact on the clinical, genomic, and biological status of LGG. CD3E, the gene for novel membrane immune biomarker deeply affecting tumor purity, may help to evaluate the prognosis and develop individual immunotherapy strategies for LGG patients. Evaluating the ratio of differential tumor purity and CD3E expression levels may provide novel insights into the complex structure of the LGG microenvironment and targeted drug development.

11.
ACS Macro Lett ; 10(1): 71-77, 2021 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-35548990

RESUMO

The glassy polymer of polystyrene (PS) enjoys a good reputation as a promising optical material; however, the inherent brittleness hinders its further applications. Conventional toughening methods are realized based on the premise of a sacrifice in transparency and stiffness. In this work, we found an unprecedented strategy to address these obstacles by combining extensional stress-induced ductility and suppressing physical aging. PS-based film with a high stiffness, long-term ductility, and excellent transparency is achieved by introducing a styrene-butadiene block copolymer into the PS matrix and subsequently annealing stretched. A nanofibrillar structure of the polybutadiene (PB) phase is formulated surrounded by a PS matrix, and thus, the elongation at break enhances from 3.1% up to 86.8%, accompanying the yield strength enhanced from 25.5 to 62.2 MPa. More significantly, compared with neat PS, these films survive from physical aging and persistent ductility over time. The morphology deformation induced by stress makes an obvious contribution to the improvement of transparency. Investigating the dynamics of chain segments indicates that the incorporation of the copolymer can restrict rearrangement and local relaxation to the PS chain. This work could pave a potential route toward high-performance PS and might be transferable to other glassy polymers with a fragile character.


Assuntos
Butadienos , Poliestirenos , Polímeros/química , Poliestirenos/química , Rejuvenescimento , Resistência à Tração
12.
Neurocrit Care ; 34(1): 154-166, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-32495315

RESUMO

BACKGROUND: Intranasal administration of insulin to the brain bypasses the blood brain barrier (BBB) and can increase cerebral glucose uptake and prevent energy failure. Intranasal insulin treatment has shown neuroprotective effects in multiple central nervous system (CNS) lesions, but the effects of intranasal insulin on the metabolic and pathological process of subarachnoid hemorrhage (SAH) are not clear. This study is designed to explore the effects of intranasal insulin treatment on metabolic distress and early brain injury (EBI) after experimental SAH. METHODS: SAH model was built by endovascular filament perforation method in adult male C57BL/6J mice, and then, insulin was administrated via intranasal route at 0, 24, and 48 h post-SAH. EBI was assessed according to the neurological performance, BBB damage, brain edema, neuroinflammatory reaction, and neuronal apoptosis at each time point. To evaluate metabolic conditions, microdialysis was used to continuously monitor the real-time levels of glucose, pyruvate, and lactate in interstitial fluid (ISF) in living animals. The mRNA and protein expression of glucose transporter-1 and 3 (GLUT-1 and -3) were also tested by RT-PCR and Western blot in brain after SAH. RESULTS: Compared to vehicle, intranasal insulin treatment promoted the relative mRNA and protein levels of GLUT-1 in SAH brain (0.98 ± 0.020 vs 0.33 ± 0.016 at 24 h, 0.91 ± 0.25 vs 0.21 ± 0.013 at 48 h and 0.94 ± 0.025 vs 0.28 ± 0.015 at 72 h in mRNA/0.96 ± 0.023 vs 0.36 ± 0.015 at 24 h, 0.91 ± 0.022 vs 0.22 ± 0.011 at 48 h and 0.95 ± 0.024 vs 0.27 ± 0.014 at 72 h in protein, n = 8/Group, p < 0.001). Similar results were also observed in GLUT-3. Intranasal insulin reduced the lactate/pyruvate ratio (LPR) and increased ISF glucose level. It also improved neurological dysfunction, BBB damage, and brain edema and attenuated the levels of pro-inflammatory cytokines as well as neuronal apoptosis after SAH. CONCLUSIONS: The intranasal insulin treatment protects brain from EBI possibly via improving metabolic distress after SAH.


Assuntos
Edema Encefálico , Lesões Encefálicas , Fármacos Neuroprotetores , Hemorragia Subaracnóidea , Administração Intranasal , Animais , Apoptose , Barreira Hematoencefálica , Edema Encefálico/tratamento farmacológico , Edema Encefálico/etiologia , Lesões Encefálicas/tratamento farmacológico , Insulina/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Fármacos Neuroprotetores/farmacologia , Ratos , Ratos Sprague-Dawley , Hemorragia Subaracnóidea/complicações , Hemorragia Subaracnóidea/tratamento farmacológico
13.
ACS Appl Mater Interfaces ; 12(16): 18840-18849, 2020 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-32223261

RESUMO

Developing high-performance electromagnetic interference (EMI) shielding materials with high absorption coefficient is highly desired for eliminating the secondary pollution of reflected electromagnetic wave (EMW). Nevertheless, it has long been a daunting challenge to achieve high shielding effectiveness (SE) and ultralow or no reflection SE simultaneously. Herein, highly porous and conductive carbon nanotube (CNT)-based carbon aerogel with a meticulously designed hierarchically porous structure from micro and sub-micro to nano levels is developed by specific two-stage pyrolysis and potassium hydroxide activation processes. The resultant activated cellulose-derived carbon aerogels (a-CCAs) exhibit an ultrahigh EMI SE of 96.4 dB in the frequency range of 8.2-12.4 GHz in conjunction with an exceptionally high absorption coefficient of 0.79 at a low density of 30.5 mg cm-3. The successful construction of hierarchically porous structure is responsible for the excellent "structurally absorbing" ability of a-CCAs, and the introduction of CNT-based heterogeneous conductive network can effectively dissipate the incident EMWs by interfacial polarization and microcurrent losses. Moreover, the as-prepared a-CCAs have a water contact angle of as high as 158.3°and a sliding angle of as low as 5.3°, revealing their superhydrophobic feature. The ingenious structure design proposed here provides a possible pathway to overcome the conflict between high EMI shielding performance and ultralow or no secondary reflection, and the as-prepared a-CCAs are exceedingly promising in the application of telecommunication, microelectronics, and spacecraft.

14.
Neurosci Bull ; 36(2): 134-142, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31309426

RESUMO

Apoptosis induced by endoplasmic reticulum (ER) stress plays a crucial role in mediating brain damage after ischemic stroke. Recently, Hes1 (hairy and enhancer of split 1) has been implicated in the regulation of ER stress, but whether it plays a functional role after ischemic stroke and the underlying mechanism remain unclear. In this study, using a mouse model of ischemic stroke via transient middle cerebral artery occlusion (tMCAO), we found that Hes1 was induced following brain injury, and that siRNA-mediated knockdown of Hes1 increased the cerebral infarction and worsened the neurological outcome, suggesting that Hes1 knockdown exacerbates ischemic stroke. In addition, mechanistically, Hes1 knockdown promoted apoptosis and activated the PERK/eIF2α/ATF4/CHOP signaling pathway after tMCAO. These results suggest that Hes1 knockdown promotes ER stress-induced apoptosis. Furthermore, inhibition of PERK with the specific inhibitor GSK2606414 markedly attenuated the Hes1 knockdown-induced apoptosis and the increased cerebral infarction as well as the worsened neurological outcome following tMCAO, implying that the protection of Hes1 against ischemic stroke is associated with the amelioration of ER stress via modulating the PERK/eIF2α/ATF4/CHOP signaling pathway. Taken together, these results unveil the detrimental role of Hes1 knockdown after ischemic stroke and further relate it to the regulation of ER stress-induced apoptosis, thus highlighting the importance of targeting ER stress in the treatment of ischemic stroke.


Assuntos
Estresse do Retículo Endoplasmático/genética , Infarto da Artéria Cerebral Média , Acidente Vascular Cerebral/genética , Acidente Vascular Cerebral/metabolismo , Fatores de Transcrição HES-1/deficiência , Fator 4 Ativador da Transcrição/metabolismo , Adenina/análogos & derivados , Adenina/farmacologia , Animais , Apoptose/genética , Encéfalo/patologia , Fator de Iniciação 2 em Eucariotos/metabolismo , Indóis/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Transdução de Sinais , Acidente Vascular Cerebral/patologia , Fator de Transcrição CHOP/metabolismo , eIF-2 Quinase/metabolismo
15.
Nan Fang Yi Ke Da Xue Xue Bao ; 39(8): 911-916, 2019 Aug 30.
Artigo em Chinês | MEDLINE | ID: mdl-31511210

RESUMO

OBJECTIVE: To investigate the effect of curcumin on the invasion and migration of human glioma cells in vitro and explore the molecular mechanisms. METHODS: MTT assay was used for screening the optimal curcumin concentrations. The effects of curcumin on the invasion and metastasis of human glioma cell lines U251 and LN229 were tested using Transwell assay, Boyden assay and wound-healing assays. The expression of the related proteins and their interactions were determined using Western blotting and coimmunoprecipitation assay. RESULTS: Curcumin at the concentration of 20 µmol/L for 48 h was used as the optimal condition for subsequent cell treatment. In the two glioma cell lines, curcumin significantly suppressed the invasion and migration of the cells (P < 0.05) and lowered the expressions of hepatoma-derived growth factor (HDGF), Ncadherin, vimentin, Snail and Slug, but increased the expression of E-cadherin. Interference of HDGF in curcumin-treated glioma cells synergistically inhibited the epithelial-mesenchymal transition (EMT) signals, while overexpression of HDGF significantly reversed the inhibitory effect of curcumin on EMT; curcumin treatment could significantly reduce the binding of HDGF to ß-catenin. CONCLUSIONS: Curcumin suppresses EMT signal by reducing HDGF/ß-catenin complex and thereby lowers the migration and invasion abilities of human glioma cells in vitro.


Assuntos
Glioma , Linhagem Celular Tumoral , Movimento Celular , Curcumina , Transição Epitelial-Mesenquimal , Humanos , Peptídeos e Proteínas de Sinalização Intercelular , Invasividade Neoplásica , beta Catenina
16.
ACS Omega ; 4(1): 509-517, 2019 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-31459345

RESUMO

Regenerated cellulose (RC) films exhibit poor water barrier performance, which seriously restricts its applications. To address this issue, an impermeable and hydrophobic graphene oxide modified by chemically grafting octadecylamine (GO-ODA) was utilized to enhance the water vapor barrier performance of RC nanocomposite films. Compared to the neat RC film, more than 20% decrease in the coefficient of water vapor permeability (P H2O) was achieved by loading only 2.0 wt % GO-ODA. The promising hydrophobicity of GO-ODA effectively retarded the formation of hydrogen bonding at the relatively weakened interface between GO and RC, compensating for the diffusion of water vapor molecules at the interface; on the other hand, the fully exfoliated GO-ODA nanosheets were inclined to align with the surface of the as-prepared RC nanocomposite films during hot-pressure drying, creating a much more tortuous pathway for diffusion of water molecules. The new insights could be valuable for widening application of cellulose such as packaging.

17.
Biomacromolecules ; 20(7): 2754-2762, 2019 07 08.
Artigo em Inglês | MEDLINE | ID: mdl-31125205

RESUMO

Substantial adsorption of water vapor triggered by hydrogen-bonding interactions between water molecules and cellulose chains (or nanoplates) is hard to avoid in nanocomposite films, although the addition of nanoplates can improve the oxygen (or carbon dioxide) barrier property. In the present work, an effective strategy is raised to decline adsorption by weakening hydrogen-bonding interactions via chemical cross-linking by epichlorohydrin (ECH) without sacrificing the homogeneous dispersion of nanoplates. The generated microdomain structure of the chemical cross-linking reaction via ECH is explicitly revealed by micro-Raman imaging. Unambiguously, Raman maps of scanning elucidate the distribution and morphology of physical and chemical cross-linking domains quantitatively. The chemical cross-linking domains are nearly uniformly located in the matrix at a low degree of cross-linking, while the interconnected and assembled networks are formed at a high degree of cross-linking. ECH boosts the formation of chemical cross-linking microdomains, bringing out the terrific water vapor barrier property and alleviating the interfacial interactions in penetration, consequently magnifying the water contact angle and holding back the water vapor permeability. Our methodology confers an effective and convenient strategy to obtain remarkable water vapor-resistant cellulose-based films that meet the practical application in the packaging fields.


Assuntos
Celulose/química , Epicloroidrina/química , Nanocompostos/química , Água/química , Celulose/farmacologia , Reagentes de Ligações Cruzadas/química , Reagentes de Ligações Cruzadas/farmacologia , Epicloroidrina/farmacologia , Ligação de Hidrogênio/efeitos dos fármacos , Permeabilidade/efeitos dos fármacos , Análise Espectral Raman , Vapor
18.
Carbohydr Polym ; 211: 237-248, 2019 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-30824085

RESUMO

Cellulose films are of poor water-vapor barrier performance. Herein, we put forward an effective way to suppress adsorption by crosslinking of hydroxyl groups via epichlorohydrin (ECH), meanwhile graphene oxide (GO) nanosheets are utilized to prolong the pathway of vapor penetration. The strategy confers a significant enhancement of vapor barrier performance as well as mechanical properties to cellulose-based films. Specifically, an outstanding reduction of 67.4% in water-vapor permeability coefficient is achieved in nanocomposite films compared to the uncrosslinked cellulose films. Furthermore, for the first time, two-dimensional correlation analysis reveals that crosslinking of ECH do not alter penetration direction, while GO can eminently act as shielding for the formation of bound water which change the sequential order of firstly-interacted vapor area from crystalline to amorphous area. Free volume is the penetration destination. The retarding effect introduced by the GO in amorphous area gives rise to the improvement of the vapor-barrier.

20.
ACS Appl Mater Interfaces ; 10(48): 41637-41644, 2018 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-30395431

RESUMO

Personal cooling technologies (PCTs) locally control the temperature of an individual instead of a whole building and are thus energy saving. However, most PCTs still consume energy and are heavy in weight, restricting their application among human beings. To achieve personal thermal comfort and no energy consumption on hot summer days, we designed a bilayer structure fabric with high thermal comfort by increasing the dissipation of human thermal radiation and reducing solar energy absorption simultaneously. The fabric consisted of two layers, including a polyethylene film with nanopores (100-1000 nm in pore size) and a film made of nylon 6 nanofibers (ca. 100 nm in diameter) with beads (ca. 230 nm in diameter), which could increase the visible light reflectance but not affect the infrared wave radiation. Therefore, the designed fabric showed a high heat dissipation power, which was 14.13, 17.93, and 17.93 W/m2 higher than that of the selected traditional textiles of cotton, linen, and odile, respectively, suggesting good cooling capability. Its cooling performance was better than those reported by the previous research works even at a higher ambient temperature. Meanwhile, the moisture penetrability and hygroscopic property results indicated that the wearing comfort of the designed fabric reached the levels of the selected traditional textiles.


Assuntos
Temperatura Corporal , Raios Infravermelhos , Nylons , Polietileno , Têxteis , Humanos
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