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1.
Plant Physiol Biochem ; 214: 108933, 2024 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-39033650

RESUMO

WRKY transcription factors are essential for coping with various biotic stresses. Pseudomonas syringae pv. actinidiae (Psa)-induced kiwifruit canker is a major problem restricting kiwifruit yield. Nevertheless, it's unclear how the kiwifruit WRKY genes respond to Psa. Through genome-wide identification, 112 WRKY members were found in 'Hongyang' genome in this work. Promoter analysis revealed that there were many cis-acting elements associated with stress responses in the AcWRKY gene's promoter region. According to transcriptomic analysis, 90 of the AcWRKY genes were differently expressed following Psa, salicylic acid (SA), or methyl jasmonate (MeJA) treatments. Almost all group III WRKYs were responsive to at least one of these treatments, with tissue-specific expression patterns. Quantitative RT-PCR study provided more evidence that Psa and SA treatments significantly induced the expression of the group III WRKY gene AcWRKY94, whereas MeJA treatment repressed it. AcWRKY94 was a transcriptionally active protein localized in the nucleus. Transient overexpression of AcWRKY94 in the leaves of 'Hongyang' enhanced the resistance of kiwifruit to Psa. Overexpression of AcWRKY94 in kiwifruit callus remarkably promoted the expression of PR and JAZ genes associated with SA and JA signals, respectively. These data imply that AcWRKY94 controls the signaling pathway dependent on SA and JA, thereby enhancing resistance to Psa. Taken together, this study establishes the basis for functional research on WRKY genes and provides important information for elucidating the resistance mechanism of kiwifruit canker disease.

2.
Mol Pharm ; 21(3): 1077-1089, 2024 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-38346386

RESUMO

Folic acid (FA) has been widely engineered to promote the targeted delivery of FA-modified nanoparticles (NPs) by recognizing the folate receptor α (FRα). However, the efficacy of FA-targeted therapy significantly varied with the abundance of FRα and natural immunoglobulin levels in different tumors. Therefore, a sequential therapy of dexamethasone (Dex)-induced FRα amplification and immunosuppression combined with FA-functionalized doxorubicin (DOX) micelles to synergistically suppress tumor proliferation was proposed in this study. In brief, a pH/reduction-responsive FA-functionalized micelle (FCSD) was obtained by grafting FA, derivatization-modified cholesterol, and 2,3-dimethylmaleic anhydride onto a chitosan oligosaccharide. The obtained FCSD/DOX NPs can effectively deliver DOX in tumors, and their targeting efficiency can be further improved with Dex pretreatment to decrease the immunoglobulin M (IgM) content in serum and amplify FRα levels on the surface of M109 cells. After internalization, charge reversal and disulfide bond breakage of FCSD vectors under the stimulation of tumor extracellular pH (pHe) and intracellular glutathione (GSH) would contribute to the disintegration of vectors and the rapid release of DOX. The sequential therapy that combined Dex pretreatment and targeted chemotherapy by FCSD/DOX NPs demonstrated superior tumor suppression compared with monotherapy, which is expected to provide a potential strategy for FRα-positive lung cancer patients.


Assuntos
Neoplasias Pulmonares , Nanopartículas , Humanos , Portadores de Fármacos/química , Neoplasias Pulmonares/tratamento farmacológico , Ácido Fólico/química , Doxorrubicina , Micelas , Nanopartículas/química , Dexametasona , Sistemas de Liberação de Medicamentos , Concentração de Íons de Hidrogênio
3.
Chemistry ; 30(24): e202304036, 2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38298129

RESUMO

MXenes have unique properties such as high electrical conductivity, excellent mechanical properties, rich surface chemistry, and convenient processability. These characteristics make them ideal for producing flexible materials with tunable microstructures. This paper reviews the laboratory research progress of flexible MXene and its composite materials for supercapacitors. And introduces the general synthesis method of MXene, as well as the preparation and properties of flexible MXene. By analyzing the current research status, the electrochemical reaction mechanism of MXene was explained from the perspectives of electrolyte and surface terminating groups. This review particularly emphasizes the composite methods of freestanding flexible MXene composite materials. The review points out that the biggest problem with flexible MXene electrodes is severe self-stacking, which reduces the number of chemically active sites, weakens ion accessibility, and ultimately lowers electrochemical performance. Therefore, it is necessary to composite MXene with other electrode materials and design a good microstructure. This review affirms the enormous potential of flexible MXene and its composite materials in the field of supercapacitors. In addition, the challenges and possible improvements faced by MXene based materials in practical applications were also discussed.

4.
Environ Sci Pollut Res Int ; 30(28): 72354-72367, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37166729

RESUMO

In this work, we synthesized activated alumina biochar composites (γ-Al2O3/BC) by sol-gel method, which improved the problem that the surface charge of γ-Al2O3 was not conducive to the removal of heavy metal cation in a neutral solution, and then explored the feasibility of removing Pb(II) by γ-Al2O3/BC as well as reusing Pb-laden waste sludge to remove phosphorus (P) and its micro-adsorption mechanisms. The results show that the maximum adsorption capacity of γ-Al2O3/BC for Pb(II) is 182.48 mg/g, and the removing capacity of recycled Pb-laden slag for P also reaches 87.13 mg/g. It was found that the presence of Pb in the slag makes P removal more effective. In addition, in the process of P removal, the Pb in the slag will not be released, which will not cause secondary pollution to the water. The micro-adsorption mechanism of Pb(II) and P on the composites was investigated by XPS, XRD, and FTIR. It demonstrates that special functional groups such as hydroxy-aluminum, hydroxyl, and carboxyl groups can remove Pb(II) through strong surface complexation and electrostatic attraction. Furthermore, the removal mechanism of P from Pb-laden sludge includes chemisorption and complexation, and the precipitation of P and Pb on the adsorbent surface is the main reason for the removal of P. Therefore, it is feasible to further effectively remove P by using the waste biochar containing Pb. The idea of this paper provides a potential method for the reuse of waste adsorbent.


Assuntos
Fósforo , Poluentes Químicos da Água , Esgotos , Chumbo , Água , Carvão Vegetal , Adsorção , Poluentes Químicos da Água/análise , Cinética
5.
Biomater Adv ; 150: 213425, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37084635

RESUMO

The efficacy of immune checkpoint therapy is limited by the immunosuppressive tumor microenvironment (TME), and lactate, the most universal component of TME, has been rediscovered that plays important roles in the regulation of metabolic pathways, angiogenesis, and immunosuppression. Here, a therapeutic strategy of acidity modulation combined with programmed death ligand-1 (PD-L1) siRNA (siPD-L1) is proposed to synergistically enhance tumor immunotherapy. The lactate oxidase (LOx) is encapsulated into the hollow Prussian blue (HPB) nanoparticles (NPs) prepared by hydrochloric acid etching followed by the modification with polyethyleneimine (PEI) and polyethylene glycol (PEG) via sulfur bonds (HPB-S-PP@LOx), siPD-L1 is loaded via electrostatic adsorption to obtain HPB-S-PP@LOx/siPD-L1. The obtained co-delivery NPs can accumulate in tumor tissue with stable systemic circulation, and simultaneous release of LOx and siPD-L1 in intracellular high glutathione (GSH) environment after uptake by tumor cells without being destroyed by lysosome. Moreover, LOx can catalyze the decomposition of lactate in the hypoxic tumor tissue with the aid of oxygen release by the HPB-S-PP nano-vector. The results show that the acidic TME regulation via lactate consumption can improve the immunosuppressive TME, including revitalizing the exhausted CD8+ T cells and decreasing the proportion of immunosuppressive Tregs, and synergistically elevating the therapeutic effect of PD1/PD-L1 blockade therapy via siPD-L1. This work provides a novel insight for tumor immunotherapy and explores a promising therapy for triple-negative breast cancer.


Assuntos
Antígeno B7-H1 , Neoplasias , Humanos , Antígeno B7-H1/genética , Antígeno B7-H1/metabolismo , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/uso terapêutico , Linfócitos T CD8-Positivos/metabolismo , Terapia de Imunossupressão , Imunoterapia/métodos , Lactatos , Microambiente Tumoral
6.
Environ Sci Pollut Res Int ; 29(29): 44794-44805, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35138533

RESUMO

Calcium and magnesium ions usually exist in natural water. When Cd2+ is removed from water by adsorption, it will be inhibited by these two ions. Titanate nanotubes (TNTs) have an effective adsorption capacity for Cd2+ due to extraordinary ion exchange property. However, TNTs also adsorb Ca2+ and Mg2+ in water. In this study, carbon-modified TNT (TNT/C) and TNT/C further treated with acid (TNT/HC) were synthesized by hydrothermal synthesis. The transmission electron microscope (TEM) images show that TNT/C or TNT/HC still keep nanotube morphology. The experimental results show the order of adsorption amount to Cd2+ is TNT (171.56 mg/g) > TNT/C (166 mg/g) > TNT/HC (159.88 mg/g) when there is no Ca2+ or Mg2+. But when there is 0.1 M Ca2+ or Mg2+ in the water, the order of Cd2+ adsorption capacity becomes TNT/HC (44.28, 49.04 mg/g) > TNT/C (58.84, 69.32 mg/g) > TNT (65.52, 70.6 mg/g). It indicates that the surface carbon modification can alleviate the hindrance of Ca2+ or Mg2+ to Cd2+ removal. This is because the carbon on the surface of TNT captured part of Ca2+ or Mg2+; it made more Cd2+ be successfully absorbed by TNT through ion exchange. This mechanism was confirmed by the X-ray photoelectron spectroscopy (XPS) spectra analysis. The results of this paper can provide ideas for the adsorption and removal of Cd2+ in water in the presence of Ca2+ or Mg2+.


Assuntos
Cálcio/química , Nanotubos , Poluentes Químicos da Água , Adsorção , Cádmio , Carbono , Cátions Bivalentes , Íons , Magnésio , Nanotubos/química , Titânio/química , Água , Poluentes Químicos da Água/química
7.
Exp Ther Med ; 20(5): 17, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32934682

RESUMO

Renal interstitial fibrosis (RIF) is a common pathological process that accompanies chronic kidney disease (CKD) and that progresses to end-stage renal failure (ESRD). Accumulating evidence has revealed that persistent mammalian target of rapamycin (mTOR) activation in kidneys is closely associated with the occurrence and progression of CKD. The DEP domain-containing mTOR interacting protein (Deptor) is an endogenous negative regulator of mTOR. Metformin can attenuate renal fibrosis in an animal model of diabetic nephropathy. Previous studies demonstrated that metformin can attenuate renal fibrosis in several models of CKD. However, the precise mechanisms of this effect are not well understood. The present study aimed to examine the mechanism of action of metformin on unilateral ureteral obstruction (UUO)-induced RIF in rats in vivo. Sprague-Dawley rats were randomly divided into a sham-operated group, three UUO groups examined at different time points (3, 7 and 14 days after UUO surgery), and three metformin-treated groups, treated with three different concentrations of metformin. The metformin-treated groups were administered metformin orally every day for 14 consecutive days following surgery. The protein expression levels of Deptor, α-smooth muscle actin (α-SMA), phosphorylated (p-)mTOR, p-ribosomal protein S6 kinase (p-p70S6K) and CD68 were assessed. The present results suggested that, following UUO, there was a significant reduction of Deptor expression, and an increase in collagen deposition in the extracellular matrix over time, accompanied by an increased expression of several proteins including CD68, α-SMA, p-mTOR and p-p70S6K. Notably, metformin treatment reversed these effects. In conclusion, the present results suggested that metformin attenuated RIF of UUO rats, and the mechanism of action was found to be associated with the increase in Deptor expression and inhibition of the mTOR/p70S6K pathway in the kidneys of UUO rats.

8.
J Exp Bot ; 71(14): 4321-4332, 2020 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-32270183

RESUMO

Whilst constitutive overexpression of particular acid phosphatases (APases) can increase utilization of extracellular organic phosphate, negative effects are frequently observed in these transgenic plants under conditions of inorganic phosphate (Pi) sufficiency. In this study, we identified rice purple acid phosphatase 10c (OsPAP10c) as being a novel and major APase that exhibits activities associated both with the root surface and with secretion. Two constructs were used to generate the OsPAP10c-overexpression plants by driving its coding sequence with either a ubiquitin promoter (UP) or the OsPAP10c-native promoter (NP). Compared with the UP transgenic plants, lower expression levels and APase activities were observed in the NP plants. However, the UP and NP plants both showed a similar ability to degrade extracellular ATP and both promoted root growth. The growth performance and yield of the NP transgenic plants were better than the wild-type and UP plants in both hydroponic and field experiments irrespective of the level of Pi supply. Overexpression of APase by its native promoter therefore provides a potential way to improve crop production that might avoid increased APase activity in untargeted tissues and its inhibition of the growth of transgenic plants.


Assuntos
Oryza , Fosfatase Ácida/genética , Fosfatase Ácida/metabolismo , Regulação da Expressão Gênica de Plantas , Organofosfatos , Oryza/genética , Oryza/metabolismo , Fosfatos/metabolismo , Fósforo/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/genética , Raízes de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo
9.
Mol Med Rep ; 19(3): 1694-1704, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30628645

RESUMO

Our previous study demonstrated that febuxostat, a xanthine oxidase inhibitor, can alleviate kidney dysfunction and ameliorate renal tubulointerstitial fibrosis in a rat unilateral ureteral obstruction (UUO) model; however, the underlying mechanisms remain unknown. Increasing evidence has revealed that epithelial­mesenchymal transition (EMT) is one of the key mechanisms mediating the progression of renal tubulointerstitial fibrosis in chronic kidney disease (CKD). Uterine sensitization­associated gene­1 (USAG­1), a kidney­specific bone morphogenetic protein antagonist, is involved in the development of numerous types of CKDs. The present study aimed to investigate the role of febuxostat in the process of EMT in Madin­Darby canine kidney (MDCK) cells in vitro. Western blotting, reverse transcription­semiquantitative polymerase chain reaction analysis and immunofluorescence staining were used to evaluate the expression levels of bone morphogenetic protein 7, USAG­1, α­smooth muscle actin (α­SMA) and E­cadherin, respectively. The results demonstrated that the expression of USAG­1 and α­SMA increased, and that of E­cadherin decreased significantly in MDCK cells following treatment with transforming growth factor­ß1 (TGF­ß1). The application of small interfering RNA­USAG­1 potently inhibited TGF­ß1­induced EMT. Subsequently, the effects of febuxostat on TGF­ß1­induced EMT was investigated. The results demonstrated that febuxostat downregulated the expression of USAG­1, and reversed TGF­ß1­induced EMT in MDCK cells. Furthermore, pretreatment with febuxostat significantly restored the decreased expression levels of phosphorylated Smad1/5/8 induced by TGF­ß1 in MDCK cells. The results of the present study suggested that USAG­1 may be involved in the EMT process of MDCK cells induced by TGF­ß1, and febuxostat inhibited EMT by activating the Smad1/5/8 signaling pathway via downregulating the expression of USAG­1 in MDCK cells.


Assuntos
Febuxostat/farmacologia , Nefropatias/tratamento farmacológico , Proteínas/genética , Fator de Crescimento Transformador beta1/genética , Proteínas Adaptadoras de Transdução de Sinal , Animais , Cães , Transição Epitelial-Mesenquimal/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Rim/efeitos dos fármacos , Rim/patologia , Nefropatias/genética , Nefropatias/patologia , Células Madin Darby de Rim Canino
10.
Biomaterials ; 192: 368-376, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30476718

RESUMO

Detecting the small amounts of proteins interacting effectively with the solid film electrodes surface still remains a challenge. To address this, in this work, a new approach was proposed by the combination of the adhesion forces and the molecular interaction measured with AFM. Cytochrome c (Cyt C) interacting effectively with TiO2 nanotube arrays (TNAs) was chosen as a probe. The amounts of Cyt C molecules interacting effectively on TNAs surface (CTNA) range from 5.5×10-12 to 7.0×10-12 mol/cm2 (68.2-86.8 ng/cm2) and they are comparable with the values obtained by the electrochemistry method in the literature, in evidence of the accuracy of this AFM-based approach. The reliability of the proposed approach was further verified by conducting Surface Enhanced Raman Scattering (SERS) measurements and estimating the enhancement factor (EF). This interaction-based AFM approach can be used to accurately obtain the small amounts of adsorbed substances on the solid film electrodes surface in the applications such as biosensors, biocatalysis, and drug delivery, etc.


Assuntos
Citocromos c/química , Proteínas Imobilizadas/química , Nanotubos/química , Titânio/química , Adsorção , Eletrodos , Microscopia de Força Atômica , Nanotubos/ultraestrutura , Propriedades de Superfície
11.
Langmuir ; 34(44): 13449-13458, 2018 11 06.
Artigo em Inglês | MEDLINE | ID: mdl-30350690

RESUMO

The ionic liquid (IL)/titanium dioxide (TiO2) interface exists in many application systems, such as nanomaterial synthesis, catalysis, and electrochemistry systems. The nanoscale interfacial properties in the above systems are a common issue. However, directly detecting the interfacial properties of nanoconfined ILs by experimental methods is still challenging. To help better learn about the interfacial issue, molecular dynamics simulations have been performed to explore the structures, vibration spectra, and hydrogen bond (HB) properties at the IL/TiO2 interface. Ethylammonium nitrate (EAN) ILs confined in TiO2 slit pores with different pore widths were studied. A unique vibrational spectrum appeared for EAN ILs confined in a 0.7 nm TiO2 slit, and this phenomenon is related to interfacial hydrogen bonds (HBs). An analysis of the HB types indicated that the interfacial NH3+ group of the cations was in an asymmetric HB environment in the 0.7 nm TiO2 slit, which led to the disappearance of the symmetric N-H stretching mode. In addition, the significant increase in the HB strength between NH3+ groups and the TiO2 surface slowed down the stretching vibration of the N-H bond, resulting in one peak in the vibrational spectra at a lower frequency. For the first time, our simulation work establishes a molecular-level relationship between the vibrational spectrum and the local HB environment of nanoconfined ILs at the IL/TiO2 interface, and this relationship is helpful for interface design in related systems.

12.
Oncol Rep ; 40(4): 2353-2362, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30066933

RESUMO

The activation of phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling and upregulation of excision repair cross complementation group 1 (ERCC1) are the two most important factors that confer resistance to cisplatin (DDP) therapy in non-small-cell lung cancer (NSCLC). Therefore, inhibition of the PI3K/Akt/mTOR signaling pathway and ERCC1 expression is a potential approach for the treatment of patients with advanced NSCLC. In the present study, whether combined treatment with DDP and BEZ235, a dual PI3K/mTOR inhibitor, could provide a synergistic antitumor effect in A549/DDP cells was investigated, and the possible mechanisms involved were explored. The half-maximal inhibitory concentration (IC50) values were calculated in A549/DDP cells. Synergistic interaction of BEZ235 and DDP was evaluated by combination index (CI) analysis. The levels of phosphorylated Akt (p-Akt), phosphorylated mTOR (p-mTOR), apoptosis-related proteins and ERCC1 were detected by western blot analysis. Apoptotic cells were quantified by flow cytometry and Hoechst 33342 staining. The migration and invasion abilities of A549/DDP cells were evaluated by wound healing and Transwell assays, respectively. It was observed that the dose reduction index (DRI) of BEZ235 was 13.82 and for DDP it was 13.58, and the CI of combination was <1 over a wide range of doses. In addition, the levels of p-Akt, p-mTOR and ERCC1 were significantly elevated by DDP treatment, and were reduced by co-administration of BEZ235 and DDP. Furthermore, the combination treatment significantly induced apoptotic cell death, decreased migration and invasion abilities compared with those treated with either BEZ235 or DDP alone. In conclusion, the combination of BEZ235 with DDP had synergistic antitumor effects in A549/DDP cells as reflected by reduced proliferation, increased apoptosis, and suppression of the migration and invasion abilities of A549/DDP cells, and the mechanism mediating these effects may be associated with the inhibition of PI3K/Akt/mTOR signaling and down-regulation of ERCC1 expression.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Proteínas de Ligação a DNA/metabolismo , Resistencia a Medicamentos Antineoplásicos , Endonucleases/metabolismo , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Neoplasias Pulmonares/patologia , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Apoptose/efeitos dos fármacos , Biomarcadores Tumorais/metabolismo , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Carcinoma Pulmonar de Células não Pequenas/patologia , Proliferação de Células/efeitos dos fármacos , Cisplatino/administração & dosagem , Humanos , Imidazóis/administração & dosagem , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/metabolismo , Quinolinas/administração & dosagem , Transdução de Sinais/efeitos dos fármacos , Células Tumorais Cultivadas
13.
Front Plant Sci ; 9: 530, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29755491

RESUMO

Aquaporins play an essential role in water uptake and transport in vascular plants. The soybean genome contains a total of 22 plasma membrane intrinsic protein (PIP) genes. To identify candidate PIPs important for soybean yield and stress tolerance, we studied the transcript levels of all 22 soybean PIPs. We found that a GmPIP2 subfamily member, GmPIP2;9, was predominately expressed in roots and developing seeds. Here, we show that GmPIP2;9 localized to the plasma membrane and had high water channel activity when expressed in Xenopus oocytes. Using transgenic soybean plants expressing a native GmPIP2;9 promoter driving a GUS-reporter gene, it was found high GUS expression in the roots, in particular, in the endoderm, pericycle, and vascular tissues of the roots of transgenic plants. In addition, GmPIP2;9 was also highly expressed in developing pods. GmPIP2;9 expression significantly increased in short term of polyethylene glycol (PEG)-mediated drought stress treatment. GmPIP2;9 overexpression increased tolerance to drought stress in both solution cultures and soil plots. Drought stress in combination with GmPIP2;9 overexpression increased net CO2 assimilation of photosynthesis, stomata conductance, and transpiration rate, suggesting that GmPIP2;9-overexpressing transgenic plants were less stressed than wild-type (WT) plants. Furthermore, field experiments showed that GmPIP2;9-overexpressing plants had significantly more pod numbers and larger seed sizes than WT plants. In summary, the study demonstrated that GmPIP2;9 has water transport activity. Its relative high expression levels in roots and developing pods are in agreement with the phenotypes of GmPIP2;9-overexpressing plants in drought stress tolerance and seed development.

14.
Langmuir ; 33(42): 11658-11669, 2017 10 24.
Artigo em Inglês | MEDLINE | ID: mdl-28930632

RESUMO

Based on our previous experimental research, we studied the absorption of CO2 in the ionic liquid, 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([hmim][Tf2N]), immobilized on TiO2 [rutile (110) ] with different thickness by molecular dynamics simulation. The effects of the properties (hydrophobicity and hydrophilicity) of solid interfaces were also studied with IL immobilized on graphite and TiO2, respectively. We studied the influence of the thickness of IL immobilized on TiO2 on the absorption of CO2 via structural and dynamical properties. The results show that the self-diffusion coefficients of IL and CO2 increase as the thickness of immobilized IL decreases. And the CO2 absorption capacity increases as the thickness of immobilized IL decreases as well. Additionally, more CO2 molecules are absorbed in the region near the solid interface as the thickness of IL decreases. For IL immobilized on graphite, the self-diffusion coefficients of cations and anions are larger than that of IL immobilized on TiO2 with the same thickness. They are also larger than nonimmobilized cations and anions.Besides, the CO2 absorption capacity of IL immobilized on TiO2 is the largest compared with IL immobilized on graphite and nonimmobilized IL with the same thickness. From our simulation work, we try to explore the microscopic mechanism that is unexplored by experimental work, and we found the important role of IL/solid interface for CO2 absorption in immobilized ILs.

15.
Langmuir ; 33(42): 11467-11474, 2017 10 24.
Artigo em Inglês | MEDLINE | ID: mdl-28859479

RESUMO

With the rapid development of a two-dimensional (2D) nanomaterial, the confined liquid binary mixture has attracted increasing attention, which has significant potential in membrane separation. Alcohol/water is one of the most common systems in liquid-liquid separation. As one of the most focused systems, recent studies have found that ethanol molecules were preferentially adsorbed on the inner surface of the pore wall and formed an adsorbed ethanol layer under 2D nanoconfinement. To evaluate the effect of the alcohol adsorption layer on the mobility of water molecules, molecular simulations were performed to investigate four types of alcohol/water binary mixtures confined under a 20 Å graphene slit. Residence times of the water molecules covering the alcohol layer were in the order of methanol/water < ethanol/water < 1-propanol/water < 1-butanol/water. Detailed microstructural analysis of the hydrogen bonding (H-bond) network elucidated the underlying mechanism on the molecular scale in which a small average number of H-bonds between the preferentially adsorbed alcohol molecules and the surrounding water molecules could induce a small degree of damage to the H-bond network of the water molecules covering the alcohol layer, resulting in the long residence time of the water molecules.

16.
Langmuir ; 33(42): 11626-11634, 2017 10 24.
Artigo em Inglês | MEDLINE | ID: mdl-28772074

RESUMO

Understanding the interactions between porous materials and biosystems is of great important in biomedical and environmental sciences. Upon atomic force microscopy (AFM) adhesion measurement, a new experimental approach was presented here to determine the molecular interaction force between proteins and mesoporous TiO2 of various surface roughnesses. The interaction force between each protein molecule and the pure anatase TiO2 surface was characterized by fitting the adhesion and adsorption capacity per unit contact area, and it was found that the adhesion forces were approximately 0.86, 2.63, and 4.41 nN for lysozyme, myoglobin, and BSA, respectively. Moreover, we reported that the molecular interaction force was independent of the surface topography of the material but the protein type is a factor of the interaction. These experimental results on the molecular level provide helpful insights for stimulating model calculation and molecular simulation studies of protein interaction with surfaces.

17.
Langmuir ; 33(36): 9201-9210, 2017 09 12.
Artigo em Inglês | MEDLINE | ID: mdl-28803477

RESUMO

The separation behaviors of Mg2+ and Li+ were investigated using molecular dynamics. Two functionalized graphene nanopore models (i.e., co_5 and coo_5) inspired by the characteristic structural features of Mg2+ channels were used. Both nanopores exhibited a higher preference to Mg2+ than to Li+, and the selectivity ratios were higher for coo_5 than for co_5 under all the studied transmembrane voltages. An evaluation of the effect of coordination on the ionic hydration microstructures for both nanopores showed that the positioning of the modified groups could better fit a hydrated Mg2+ than a hydrated Li+, as if Mg2+ was not dehydrated according to hydrogen bond analysis of the ionic hydration shells. This condition led to a lower resistance for Mg2+ than for Li+ when traveling through the nanopores. Moreover, a distinct increase in hydrogen bonds occurred with coo_5 compared with co_5 for hydrated Li+, which made it more difficult for Li+ to pass through coo_5. Thus, a higher Mg2+/Li+ selectivity was found in for coo_5 than for co_5. These findings provide some design principles for developing artificial Mg2+ channels, which have potential applications as Mg2+ sensors and novel devices for Mg2+/Li+ separation.

18.
Cureus ; 9(3): e1128, 2017 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-28465875

RESUMO

OBJECTIVE: Management of ductal carcinoma in situ (DCIS) remains controversial. This study examined long-term outcomes in a population-based cohort of patients with pure DCIS treated with breast-conserving surgery (BCS) alone, BCS + radiotherapy (RT), and mastectomy. Outcomes were compared between patients referred versus not referred for oncologic assessment after definitive surgery. MATERIALS AND METHODS: Subjects were 2575 women diagnosed between 1985 and 1999. Data from several electronic databases were linked and analyzed. Outcomes were invasive local recurrence-free survival (ILRFS), mastectomy-free survival (MFS), breast cancer-specific survival (BCSS), and overall survival (OS). RESULTS: Median follow-up time was 9.8 years. Overall, 56% (n = 1448) of subjects were referred to a cancer centre. Factors associated with non-referral were older age, comorbidities, and travel distance. Ten-year MFS, BCSS, and OS were higher among referred patients (all p ≤ 0.001). In cohorts treated with BCS alone (n = 1314) vs. BCS + RT (n = 510) vs. mastectomy (n = 751), 10-year ILRFS were 93.7% vs. 96.6% vs. 97.7%, (p < 0.001) and BCSS were 97.6% vs. 99.8% vs. 98.6%, (p = 0.01). Corresponding rates of ipsilateral invasive breast relapse at 10 years were 6.3% after BCS alone, 3.4% after BCS + RT, and 2.3% after mastectomy (p < 0.001). On multivariable analysis, factors associated with improved ILRFS were older age at diagnosis, low comorbidity score, absence of comedo histology, mastectomy, and post-BCS RT. CONCLUSION: Patients with DCIS referred for oncologic assessment were more likely to undergo post-BCS RT, resulting in lower mastectomy and higher survival rates compared to non-referred patients. Patients with significant comorbidities were less likely to be referred and experienced lower ILRFS and BCSS. Referral for multidisciplinary oncologic assessment after surgery is warranted to individualize management and optimize outcomes for patients with DCIS.

19.
Plant Cell Physiol ; 58(5): 885-892, 2017 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-28371895

RESUMO

During phosphate (Pi) starvation or leaf senescence, the accumulation of intracellular and extracellular purple acid phosphatases (PAPs) increases in plants in order to scavenge organic phosphorus (P). In this study, we demonstrated that a PAP-encoding gene in rice, OsPAP26, is constitutively expressed in all tissues. While the abundance of OsPAP26 transcript is not affected by Pi supply, it is up-regulated during leaf senescence. Furthermore, Pi deprivation and leaf senescence greatly increased the abundance of OsPAP26 protein. Overexpression or RNA interference (RNAi) of OsPAP26 in transgenic rice significantly increased or reduced APase activities, respectively, in leaves, roots and growth medium. Compared with wild-type (WT) plants, Pi concentrations of OsPAP26-overexpressing plants increased in the non-senescing leaves and decreased in the senescing leaves. The increased remobilization of Pi from the senescing leaves to non-senescing leaves in the OsPAP26-overexpressing plants resulted in better growth performance when plants were grown in Pi-depleted condition. In contrast, OsPAP26-RNAi plants retained more Pi in the senescing leaves, and were more sensitive to Pi starvation stress. OsPAP26 was found to localize to the apoplast of rice cells. Western blot analysis of protein extracts from callus growth medium confirmed that OsPAP26 is a secreted PAP. OsPAP26-overexpressing plants were capable of converting more ATP into inorganic Pi in the growth medium, which further supported the potential role of OsPAP26 in utilizing organic P in the rhizosphere. In summary, we concluded that OsPAP26 performs dual functions in plants: Pi remobilization from senescing to non-senescing leaves; and organic P utilization.


Assuntos
Fosfatase Ácida/metabolismo , Glicoproteínas/metabolismo , Oryza/enzimologia , Oryza/metabolismo , Proteínas de Plantas/metabolismo , Fosfatase Ácida/genética , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Glicoproteínas/genética , Oryza/genética , Fosfatos/metabolismo , Fósforo/metabolismo , Folhas de Planta/genética , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Raízes de Plantas/enzimologia , Raízes de Plantas/genética , Raízes de Plantas/metabolismo , Plantas Geneticamente Modificadas/enzimologia , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo
20.
Langmuir ; 32(51): 13778-13786, 2016 12 27.
Artigo em Inglês | MEDLINE | ID: mdl-27756127

RESUMO

Residual Mg2+ reduces the performance of lithium-ion batteries. However, separating Mg2+ and Li+ is difficult because of their similar ionic properties. Inspired by the high selectivity of biological Mg2+ channels, this work utilizes atomistic simulations to investigate the ability of graphene-based nanopores with diameters of 0.789, 1.024, and 1.501 nm to separate Mg2+ and Li+ under a series of transmembrane voltages. We analyzed the spatial distribution of molecules in the nanopores' vicinity, structure properties of ionic hydration, and potential of mean force of ions traveling through the nanopores. Separation was mainly caused by the difference in dehydration between the second hydration shells of Mg2+ and Li+. When ions traveled through nanopores, Li+ had to overcome a greater energy barrier than Mg2+ because it had to shed more water molecules and break more hydrogen bonds in the second hydration shell compared with Mg2+. Moreover, the ionic Coulomb blockade of Mg2+ occurred near the pore mouth, impeding Li+ transport and increasing selectivity when the pore diameter decreased to subnanometer.

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