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1.
Materials (Basel) ; 16(6)2023 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-36984017

RESUMO

Though previous studies have indicated that the fresh behaviours of plain mortar/concrete are mainly governed by the average water film thickness (AWFT), whether the concept of AWFT is also applicable to fibrous mortar/concrete still needs to be explored. Furthermore, for fibrous mortar/concrete, it is obvious that the fibres added also have certain effects on the fresh behaviours. In two previous studies on basalt fibre-reinforced mortar (BFRM), the integral effects of the AWFT and fibre dosage as well as the integral effects of the AWFT and fibre length were individually investigated. In this study, a fibre factor (FF) defined as the fibre volume multiplied by the fibre aspect ratio was employed and 24 extra mortar groups were tested. A total of 68 mortar groups were applied in numerical analysis. The results of the regression analysis yielded good correlations of the workability, fluidity, cohesiveness, and adhesiveness of BFRM with the AWFT and FF, suggesting that the AWFT and FF are together the governing parameters controlling the fresh behaviours of BFRM. Hence, the AWFT and FF may be used to develop a model for the fresh properties of BFRM.

2.
ACS Appl Mater Interfaces ; 14(50): 56193-56202, 2022 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-36475587

RESUMO

Highly conductive, durable, and breathable metal-coated textiles are critical building block materials for future wearable electronics. In order to enhance the metal adhesion on the textile surface, existing solution-based approaches to preparing these materials require time-consuming presynthesis and/or premodification processes, typically in the order of tens of minutes to hours, on textiles prior to metal plating. Herein, we report a UV-induced rapid polymer-assisted metal deposition (r-PAMD) that offers a destructive-treatment-free process to deposit highly conductive metals on a wide variety of textile materials, including cotton, polyester, nylon, Kevlar, glass fiber, and carbon cloth. In comparison to the state of the arts, r-PAMD significantly shortens the modification time to several minutes and is compatible with the roll-to-roll fabrication manner. Moreover, the deposited metals show outstanding adhesion, which withstands rigorous flexing, abrasion, and machine washing tests. We demonstrate that these metal-coated textiles are suitable for applications in two vastly different fields, being wearable and washable sensors, and lithium batteries.

3.
Sci Total Environ ; 838(Pt 1): 155770, 2022 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-35533870

RESUMO

Microplastics are emergent threats to marine organisms as ingestion can cause a multitude of physiological problems. Suspension feeders, including marine invertebrate larvae, are particularly susceptible to ingesting microplastics due to similarities in physical appearance to algal cells. Larval feeding involves multiple stages: the capture and subsequent selection of particles followed by ingestion from the mouth to the stomach, digestion, and finally, egestion. Yet, little is known about which aspect of the feeding process is disrupted by microplastics. Here, we determine if prior exposure to microplastics alters the feeding behavior of the larval sea urchin Heliocidaris crassispina. We conducted two experiments: a food handling experiment studied larval survival, growth, and time required to fill and vacate the stomach; and a particle selection experiment analyzed changes in the ability of the larvae to selectively ingest algal cells over microplastics. In both experiments, larvae were pre-exposed to algae only (control), the addition of 10 µm polystyrene beads at 1 bead mL-1 or 1000 beads mL-1 until 3- or 7-days post-fertilization. Previous exposure to microplastics lengthened stomach filling time and impaired particle selection. While there was no significant change in survivorship and larval arm length, these sub-lethal impacts on larval feeding likely have more severe ramifications in vivo where food is limited, and thus, potentially threaten post-settlement success.


Assuntos
Microplásticos , Poluentes Químicos da Água , Animais , Larva , Plásticos/toxicidade , Poliestirenos/análise , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
4.
Nat Commun ; 13(1): 1626, 2022 03 25.
Artigo em Inglês | MEDLINE | ID: mdl-35338152

RESUMO

The combination of EGF, CHIR99021, A83-01, SB431542, VPA, and Y27632 (EGF/CASVY) facilitates the derivation of trophoblast stem (TS) cells from human blastocysts and first-trimester, but not term, cytotrophoblasts. The mechanism underlying this chemical induction of TS cells remains elusive. Here we demonstrate that the induction efficiency of cytotrophoblast is determined by functional antagonism of the placental transcription factor GCM1 and the stemness regulator ΔNp63α. ΔNp63α reduces GCM1 transcriptional activity, whereas GCM1 inhibits ΔNp63α oligomerization and autoregulation. EGF/CASVY cocktail activates ΔNp63α, thereby partially inhibiting GCM1 activity and reverting term cytotrophoblasts into stem cells. By applying hypoxia condition, we can further reduce GCM1 activity and successfully induce term cytotrophoblasts into TS cells. Consequently, we identify mitochondrial creatine kinase 1 (CKMT1) as a key GCM1 target crucial for syncytiotrophoblast differentiation and reveal decreased CKMT1 expression in preeclampsia. Our study delineates the molecular underpinnings of trophoblast stemness and differentiation and an efficient method to establish TS cells from term placentas.


Assuntos
Fator de Crescimento Epidérmico , Trofoblastos , Diferenciação Celular , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Fator de Crescimento Epidérmico/metabolismo , Feminino , Humanos , Proteínas Nucleares/metabolismo , Placenta/metabolismo , Gravidez , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Trofoblastos/metabolismo , Proteínas Supressoras de Tumor
5.
ACS Biomater Sci Eng ; 8(2): 484-492, 2022 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-35073055

RESUMO

In this study, solid fibroin fibers (FFs) were directly cross-linked by employing a ruthenium-mediated redox pair under visible light at room temperature for the first time. The chemical cross-link through dityrosine connection was confirmed by Fourier-transform infrared (FTIR) spectroscopy, fluorescence spectra, and a solubility test. The resultant cross-link density of fibers was calculated based on their swelling ratio evaluation in LiBr solution. Further applying stretch to the fibers during irradiation increased the fiber strength to higher values. The break stress and Young's modulus of photo-cross-linked 15% stretch FFs reached a 60-90% increase in comparison to the original FFs in dry and wet conditions. This approach constitutes an easy and straightforward strategy for strengthening FFs, which is scalable industrially to enhance FFs in a wide range of applications.


Assuntos
Fibroínas , Seda , Módulo de Elasticidade , Fibroínas/química , Seda/química , Espectroscopia de Infravermelho com Transformada de Fourier
6.
J Cardiothorac Surg ; 16(1): 151, 2021 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-34051789

RESUMO

BACKGROUND: Papillary fibroelastomas are rare but benign cardiac tumour that are often found on cardiac valvular surfaces. Their clinical manifestations ranging from clinically asymptomatic to substantial complications that are usually secondary to systemic embolism. Multiple theories have been proposed to explain the pathophysiology of its formation. CASE PRESENTATION: We reported a rare case of large papillary fibroelastoma in the right atrium of a young gentleman which was complicated with pulmonary embolism. Transthoracic echocardiography identified a large pedunculated mass measuring 3.4cmX3.4cmX2cm in right atrium with stalk attached to interatrial septum. The intracardiac mass was resected surgically, which revealed papillary fibroelastoma in histology examination. CONCLUSION: Differential diagnosis of intracardiac masses requires clinical information, laboratory tests and imaging modalities including echocardiography. Incidentally discovered papillary fibroelastomas are treated on the basis of their sizes, site, mobility and potential embolic complications. Due to the embolic risk inherent to intraacardiac masses, surgical resection represents an effective curative protocol in treating both symptomatic and asymptomatic right sided and left sided papillary fibroelastomas, with excellent long term postoperative prognosis.


Assuntos
Fibroelastoma Papilar Cardíaco/diagnóstico , Dispneia/etiologia , Embolia Pulmonar/etiologia , Adulto , Fibroelastoma Papilar Cardíaco/complicações , Fibroelastoma Papilar Cardíaco/patologia , Fibroelastoma Papilar Cardíaco/cirurgia , Cateteres de Demora , Cateteres Venosos Centrais , Nefropatias Diabéticas/complicações , Diagnóstico Diferencial , Ecocardiografia , Átrios do Coração/diagnóstico por imagem , Átrios do Coração/patologia , Humanos , Masculino , Diálise Renal
7.
Carbohydr Polym ; 259: 117737, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33673998

RESUMO

Tough hydrogels with shape memory property are highly desirable for actuators and smart engineering materials. Herein, super-tough polyacrylamide/iota-carrageenan double-network hydrogels were synthesized via a one-pot radical polymerization and strengthened by incorporating bacterial cellulose microclusters, through the intermolecular hydrogen bonds and topological interlock between microclusters and polymer network. Such hydrogels were able to withstand over 200 kPa of tensile stress, or be stretched over 27 times of initial length, and reached a high toughness of ∼2000 kJ/m3. By tension-drying and post-annealing treatments on the strongest hydrogel, dry strands were fabricated to withstand over 100 MPa of tensile stress. Moreover, these strands presented water-stimulated shape memory by a recovery ratio of 84.3 % in 4 min. Based on these characteristics, this super-tough hydrogel may serve as smart textile or actuator for a variety of applications.


Assuntos
Celulose/química , Hidrogéis/química , Resinas Acrílicas/química , Carragenina/química , Porosidade , Resistência à Tração
8.
Materials (Basel) ; 13(24)2020 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-33322109

RESUMO

Strength and stiffness are the key parameters characterising the bond performance of fibres in concrete. However, a straightforward procedure for estimating the bond parameters of a synthetic macro-fibre does not exist. This study employs pull-out tests to investigate the bond behaviour of synthetic macro-fibres. Two types of macro-fibres available in the market were investigated. A gripping system was developed to protect the fibres from local damage. The experimental campaign consisted of two stages. At the first stage, 32 concrete specimens were manufactured for performing 96 pull-out tests (three fibre samples were embedded in each cube perpendicular to the top surface and two sides). Two types of macro-fibres with either 10 or 20 mm embedment length were tested. The obtained load-displacement diagrams from pull-out tests demonstrate that the bond performance (characterised by the strength and deformation modulus) of the "top" fibres is almost 20% weaker than fibres positioned to the side surfaces. At the second stage, one type of macro-fibre was chosen for further experimentation of the feasibility of improving the bond performance through the use of colloidal silica or steel micro-fibres. This investigation stage employed an additional 36 concrete specimens. The use of steel micro-fibres was found to be an efficient alternative. The success of this solution requires a suitable proportioning of the concrete.

9.
Blood ; 135(3): 191-207, 2020 01 16.
Artigo em Inglês | MEDLINE | ID: mdl-31750881

RESUMO

Protein acetylation is an important contributor to cancer initiation. Histone deacetylase 6 (HDAC6) controls JAK2 translation and protein stability and has been implicated in JAK2-driven diseases best exemplified by myeloproliferative neoplasms (MPNs). By using novel classes of highly selective HDAC inhibitors and genetically deficient mouse models, we discovered that HDAC11 rather than HDAC6 is necessary for the proliferation and survival of oncogenic JAK2-driven MPN cells and patient samples. Notably, HDAC11 is variably expressed in primitive stem cells and is expressed largely upon lineage commitment. Although Hdac11is dispensable for normal homeostatic hematopoietic stem and progenitor cell differentiation based on chimeric bone marrow reconstitution, Hdac11 deficiency significantly reduced the abnormal megakaryocyte population, improved splenic architecture, reduced fibrosis, and increased survival in the MPLW515L-MPN mouse model during primary and secondary transplantation. Therefore, inhibitors of HDAC11 are an attractive therapy for treating patients with MPN. Although JAK2 inhibitor therapy provides substantial clinical benefit in MPN patients, the identification of alternative therapeutic targets is needed to reverse MPN pathogenesis and control malignant hematopoiesis. This study establishes HDAC11 as a unique type of target molecule that has therapeutic potential in MPN.


Assuntos
Hematopoese , Histona Desacetilases/fisiologia , Mutação , Transtornos Mieloproliferativos/patologia , Oncogenes , Animais , Apoptose , Ciclo Celular , Proliferação de Células , Inibidores de Histona Desacetilases/farmacologia , Histona Desacetilases/química , Humanos , Janus Quinase 1/genética , Janus Quinase 1/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Transtornos Mieloproliferativos/tratamento farmacológico , Transtornos Mieloproliferativos/metabolismo , Fatores de Transcrição STAT/genética , Fatores de Transcrição STAT/metabolismo , Células Tumorais Cultivadas
10.
Polymers (Basel) ; 11(1)2019 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-30960048

RESUMO

Flexible gel fibers with high stretchability were synthesized from physically cross-linked agar and covalently cross-linked polyacrylamide networks. Such gel material can withstand the temperature required for thermal curing of polydimethylsiloxane (PDMS), when the water in the gel was partially replaced with ethylene glycol. This gel template supported thermal replica molding of PDMS to produce high quality microchannels. Microchannels with different cross sections and representative 3D structures, including bifurcating junction, helical and weave networks, were smoothly fabricated, based on the versatile manipulation of gel templates. This gel material was confirmed as a flexible and reliable template in fabricating 3D microfluidic channels for potential devices.

11.
ACS Biomater Sci Eng ; 5(6): 3119-3130, 2019 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-33405544

RESUMO

In order to improve the water absorbency of natural silk and extend its applications in wider areas, silk fibroin (SF)-based fibers were prepared by coaxial wet spinning. Using a custom-made wet spinning device with coaxial spinneret, continuous core-sheath fibers were finally obtained by adjusting the core dope into iota-carrageenan/polyacrylamide hot solution and sheath dope into SF/polyurethane solution. These core-sheath fibers were characterized with respect to morphology, SF secondary structure, mechanical property, and water absorbency. Fibers fabricated from 17 wt % SF/polyurethane solution presented the most regular morphology with homogeneous and circular cross-section. Double-layered hollow structure was observed in these fibers. ß-Sheet conformation was mainly adopted by the SF in fibers as indicated in XRD analysis and FTIR spectra. The fibers demonstrated higher absorbency than the raw silk and fine incorporation of long-lasting glowing pigment, indicating potential applications in water or thermal management textile and phototherapy.

12.
FASEB J ; 33(1): 314-326, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-29979633

RESUMO

Migration of placental extravillous trophoblast (EVT) cells into uterine decidua facilitates the establishment of blood circulation between mother and fetus and is modulated by EVT-decidual cell interaction. Poor or excessive EVT migration is associated with pregnancy complications such as preeclampsia or placenta accreta. Glial cells missing 1 (GCM1) transcription factor is essential for placental development, and decreased GCM1 activity is detected in preeclampsia. To study whether GCM1 regulates trophoblast cell migration, here we showed that GCM1 promotes BeWo and JAR trophoblast cell migration through a novel target gene, WNT10B. Moreover, WNT10B signaling stimulated cytoskeletal remodeling via Rac1 and frizzled 7 (FZD7) was identified as the cognate receptor for WNT10B to up-regulate cell migration. We further showed that secreted frizzled-related protein 3 (SFRP3) is expressed in uterine decidual cells by immunohistochemistry and that SFRP3 expression in telomerase-transformed human endometrial stromal cells (T-HESCs) is elevated under decidualization stimuli and further enhanced by bone morphogenetic protein 2 via SMAD1. SFRP3 blocked the interaction between FZD7 and WNT10B to decrease BeWo cell migration, which corroborated the elevated BeWo cell migration when cocultured with decidualized and SFRP3-knockdown T-HESC monolayer. Our results suggest that GCM1 up-regulates EVT cell migration through WNT10B and FZD7, which is negatively modulated by decidual SFRP3.-Wang, L.-J., Lo, H.-F., Lin, C.-F., Ng, P.-S., Wu, Y.-H., Lee, Y.-S., Cheong, M.-L., Chen, H. SFRP3 negatively regulates placental extravillous trophoblast cell migration mediated by the GCM1-WNT10B-FZD7 axis.


Assuntos
Movimento Celular , Receptores Frizzled/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas Nucleares/metabolismo , Placenta/fisiologia , Proteínas Proto-Oncogênicas/metabolismo , Fatores de Transcrição/metabolismo , Trofoblastos/fisiologia , Proteínas Wnt/metabolismo , Células Cultivadas , Proteínas de Ligação a DNA , Decídua/citologia , Decídua/fisiologia , Endométrio/citologia , Endométrio/fisiologia , Feminino , Receptores Frizzled/genética , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Neuroglia/citologia , Neuroglia/fisiologia , Proteínas Nucleares/genética , Placenta/citologia , Gravidez , Proteínas Proto-Oncogênicas/genética , Células Estromais/citologia , Células Estromais/fisiologia , Fatores de Transcrição/genética , Trofoblastos/citologia , Proteínas Wnt/genética
13.
Bioorg Med Chem Lett ; 28(12): 2143-2147, 2018 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-29776742

RESUMO

N-Hydroxy-2-arylisoindoline-4-carboxamides are potent and selective inhibitors of HDAC11. The discovery, synthesis, and structure activity relationships of this novel series of inhibitors are reported. An advanced analog (FT895) displays promising cellular activity and pharmacokinetic properties that make it a useful tool to study the biology of HDAC11 and its potential use as a therapeutic target for oncology and inflammation indications.


Assuntos
Descoberta de Drogas , Inibidores Enzimáticos/farmacologia , Histona Desacetilases/metabolismo , Isoindóis/farmacologia , Animais , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Humanos , Isoindóis/síntese química , Isoindóis/química , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Estrutura Molecular , Proteínas Recombinantes/metabolismo , Relação Estrutura-Atividade
14.
Materials (Basel) ; 10(6)2017 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-28773024

RESUMO

This study investigates the mechanical behavior of steel fiber-reinforced concrete (SFRC) beams internally reinforced with steel bars and externally bonded with carbon fiber-reinforced polymer (CFRP) sheets fixed by adhesive and hybrid jointing techniques. In particular, attention is paid to the load resistance and failure modes of composite beams. The steel fibers were used to avoiding the rip-off failure of the concrete cover. The CFRP sheets were fixed to the concrete surface by epoxy adhesive as well as combined with various configurations of small-diameter steel pins for mechanical fastening to form a hybrid connection. Such hybrid jointing techniques were found to be particularly advantageous in avoiding brittle debonding failure, by promoting progressive failure within the hybrid joints. The use of CFRP sheets was also effective in suppressing the localization of the discrete cracks. The development of the crack pattern was monitored using the digital image correlation method. As revealed from the image analyses, with an appropriate layout of the steel pins, brittle failure of the concrete-carbon fiber interface could be effectively prevented. Inverse analysis of the moment-curvature diagrams was conducted, and it was found that a simplified tension-stiffening model with a constant residual stress level at 90% of the strength of the SFRC is adequate for numerically simulating the deformation behavior of beams up to the debonding of the CFRP sheets.

16.
Cancer Discov ; 6(1): 59-70, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26490423

RESUMO

UNLABELLED: Ribosome biogenesis and protein synthesis are dysregulated in many cancers, with those driven by the proto-oncogene c-MYC characterized by elevated Pol I-mediated ribosomal rDNA transcription and mTORC1/eIF4E-driven mRNA translation. Here, we demonstrate that coordinated targeting of rDNA transcription and PI3K-AKT-mTORC1-dependent ribosome biogenesis and protein synthesis provides a remarkable improvement in survival in MYC-driven B lymphoma. Combining an inhibitor of rDNA transcription (CX-5461) with the mTORC1 inhibitor everolimus more than doubled survival of Eµ-Myc lymphoma-bearing mice. The ability of each agent to trigger tumor cell death via independent pathways was central to their synergistic efficacy. CX-5461 induced nucleolar stress and p53 pathway activation, whereas everolimus induced expression of the proapoptotic protein BMF that was independent of p53 and reduced expression of RPL11 and RPL5. Thus, targeting the network controlling the synthesis and function of ribosomes at multiple points provides a potential new strategy to treat MYC-driven malignancies. SIGNIFICANCE: Treatment options for the high proportion of cancers driven by MYC are limited. We demonstrate that combining pharmacologic targeting of ribosome biogenesis and mTORC1-dependent translation provides a remarkable therapeutic benefit to Eµ-Myc lymphoma-bearing mice. These results establish a rationale for targeting ribosome biogenesis and function to treat MYC-driven cancer.


Assuntos
Benzotiazóis/administração & dosagem , DNA Ribossômico/antagonistas & inibidores , Everolimo/administração & dosagem , Linfoma de Células B/terapia , Naftiridinas/administração & dosagem , Proteínas Proto-Oncogênicas c-myc/genética , Animais , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Benzotiazóis/farmacologia , Sinergismo Farmacológico , Everolimo/farmacologia , Humanos , Linfoma de Células B/genética , Camundongos , Naftiridinas/farmacologia , Biossíntese de Proteínas/efeitos dos fármacos , Proto-Oncogene Mas , Transdução de Sinais/efeitos dos fármacos , Análise de Sobrevida , Transcrição Gênica/efeitos dos fármacos , Resultado do Tratamento , Ensaios Antitumorais Modelo de Xenoenxerto
17.
Nat Commun ; 6: 7645, 2015 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-26134520

RESUMO

SIRT1, the founding member of the mammalian family of seven NAD(+)-dependent sirtuins, is composed of 747 amino acids forming a catalytic domain and extended N- and C-terminal regions. We report the design and characterization of an engineered human SIRT1 construct (mini-hSIRT1) containing the minimal structural elements required for lysine deacetylation and catalytic activation by small molecule sirtuin-activating compounds (STACs). Using this construct, we solved the crystal structure of a mini-hSIRT1-STAC complex, which revealed the STAC-binding site within the N-terminal domain of hSIRT1. Together with hydrogen-deuterium exchange mass spectrometry (HDX-MS) and site-directed mutagenesis using full-length hSIRT1, these data establish a specific STAC-binding site and identify key intermolecular interactions with hSIRT1. The determination of the interface governing the binding of STACs with human SIRT1 facilitates greater understanding of STAC activation of this enzyme, which holds significant promise as a therapeutic target for multiple human diseases.


Assuntos
Lisina/metabolismo , Sirtuína 1/química , Sequência de Aminoácidos , Sítios de Ligação/genética , Domínio Catalítico/genética , Cristalização , Cristalografia por Raios X , Medição da Troca de Deutério , Escherichia coli , Vetores Genéticos , Humanos , Espectrometria de Massas , Simulação de Dinâmica Molecular , Mutagênese Sítio-Dirigida , Ligação Proteica , Sirtuína 1/genética , Sirtuína 1/metabolismo , Transfecção
18.
J Colloid Interface Sci ; 440: 32-8, 2015 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-25460686

RESUMO

Bacterial cellulose (BC) nanofiber membranes were simply aminalized by a flush-coating and post-crosslinking method. Firstly, wet BC membranes were flushed through by an aqueous solution of polyethylenimine (PEI) and glycerol diglycidyl ether (GDE) under vacuum suction, then further heated up to 70 °C to crosslink the resultant coating on the surface of the nanofibers. The PEI coated bacterial cellulose (BC@PEI) nanofiber membrane presented excellent adsorption performance for Cu(2+) and Pb(2+) ions from aqueous solutions. Desorption of these ions was achieved using ethylene diamine tetraacetic acid treatment. This cycle of adsorption and desorption was repeated for several times with good remain adsorption performance (over 90%). Furthermore, the adsorbed Cu(2+) ions can be reduced to copper nanoparticles, and showed excellent catalytic performance for methylene blue reduction in aqueous solution. The catalytic performance can remained after several times of usage.


Assuntos
Bactérias/química , Celulose/química , Membranas Artificiais , Nanofibras/química , Polietilenoimina/química , Adsorção , Catálise , Microscopia Eletrônica de Varredura , Termodinâmica
19.
J Mater Chem B ; 2(43): 7631-7638, 2014 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-32261901

RESUMO

Recoverable hydrogels with high stretch and toughness have been synthesized by a one-step radical polymerization. They consist of covalently crosslinked polyacrylamide (PAAm) and ionically crosslinked carrageenan. Such double network (DN) hydrogels can be stretched beyond 20 times their initial length, and their fracture energy reached a high value of ∼9500 J m-2. By comparing hydrogel tensile properties at different temperatures, the contribution of ionic network to the toughness was quantitatively determined in percentage for the first time. The stretched hydrogels were completely healed by short treatment at a mild temperature. Through drying at stretch, they were also transformed into stiff absorbent fibers that still preserved their shape memory of wet state.

20.
Eur J Cancer ; 49(18): 3936-44, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24011934

RESUMO

BACKGROUND: Ovarian cancer is the major cause of death from gynaecological malignancy with a 5year survival of only ∼30% due to resistance to platinum and paclitaxel-based first line therapy. Dysregulation of the phosphoinositide 3-kinase/mammalian target of rapamycin (PI3K/mTOR) and RAS/extracellular signal-regulated kinase (ERK) pathways is common in ovarian cancer, providing potential new targets for 2nd line therapy. METHODS: We determined the inhibition of proliferation of an extensive panel of ovarian cancer cell lines, encompassing all the major histotypes, by the dual PI3K/mTOR inhibitor PF-04691502 and a MEK inhibitor, PD-0325901. In addition, we analysed global gene expression, mutation status of key PI3K/mTOR and RAS/ERK pathway members and pathway activation to identify predictors of drug response. RESULTS: PF-04691502 inhibits proliferation of the majority of cell lines with potencies that correlate with the extent of pathway inhibition. Resistant cell lines were characterised by activation of the RAS/ERK pathway as indicated by differential gene expression profiles and pathway activity analysis. PD-0325901 suppressed growth of a subset of cell lines that were characterised by high basal RAS/ERK signalling. Strikingly, using PF-04691502 and PD-0325901 in combination resulted in synergistic growth inhibition in 5/6 of PF-04691502 resistant cell lines and two cell lines resistant to both single agents showed robust synergistic growth arrest. Xenograft studies confirm the utility of combination therapy to synergistically inhibit tumour growth of PF-04691502-resistant tumours in vivo. CONCLUSIONS: These studies identify dual targeted inhibitors of PI3K/mTOR in combination with inhibitors of RAS/ERK signalling as a potentially effective new approach to treating ovarian cancer.


Assuntos
Benzamidas/farmacologia , Proliferação de Células/efeitos dos fármacos , Difenilamina/análogos & derivados , Neoplasias Ovarianas/tratamento farmacológico , Piridonas/farmacologia , Pirimidinas/farmacologia , Transdução de Sinais/efeitos dos fármacos , Animais , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Benzamidas/administração & dosagem , Linhagem Celular Tumoral , Difenilamina/administração & dosagem , Difenilamina/farmacologia , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Sinergismo Farmacológico , MAP Quinases Reguladas por Sinal Extracelular/genética , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Feminino , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Immunoblotting , MAP Quinase Quinase 1/antagonistas & inibidores , MAP Quinase Quinase 1/genética , MAP Quinase Quinase 1/metabolismo , MAP Quinase Quinase 2/antagonistas & inibidores , MAP Quinase Quinase 2/genética , MAP Quinase Quinase 2/metabolismo , Camundongos Endogâmicos BALB C , Camundongos Nus , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/patologia , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Inibidores de Fosfoinositídeo-3 Quinase , Piridonas/administração & dosagem , Pirimidinas/administração & dosagem , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais/genética , Serina-Treonina Quinases TOR/antagonistas & inibidores , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto , Proteínas ras/genética , Proteínas ras/metabolismo
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