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1.
J Immunol ; 207(8): 2118-2128, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34507947

RESUMO

Sepsis is a life-threatening organ dysfunction caused by a dysfunctional host response to infection. Neutrophils play a protective role by releasing antibacterial proteins or by phagocytizing bacteria. However, excess neutrophils can induce tissue damage. Recently, a novel intercellular communication pathway involving extracellular vesicles (EVs) has garnered considerable attention. However, whether EVs secreted by macrophages mediate neutrophil recruitment to infected sites has yet to be studied. In this study, we assessed the chemotactic effect of EVs isolated from mouse Raw264.7 macrophages on mouse neutrophils and found that CXCL2 was highly expressed in these EVs. By regulating CXCL2 in Raw264.7 macrophages, we found that CXCL2 on macrophage EVs recruited neutrophils in vitro and in vivo. The CXCL2 EVs activated the CXCR2/PKC/NOX4 pathway and induced tissue damage. This study provides information regarding the mechanisms underlying neutrophil recruitment to tissues and proposes innovative strategies and targets for the treatment of sepsis.

2.
Int J Biol Macromol ; 186: 377-384, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34256072

RESUMO

The exploiting of abundant natural polymers as potential absorbents for heavy metal ions is attracting. Cellulose is the most abundant natural polymer and exhibits amazing properties such as high chemical stability, hydrophilicity and biodegradability. However, some properties of pure cellulose-based materials including adsorbability are usually not enough, so it is important to improve their properties to broaden their applications. In the present work, hydroxyapitite (HAP) nanoparticles were prepared and introduced to improve the cellulose hydrogel (CG) properties. The structure and properties of the resultant cellulose/HAP nanocomposite hydrogels (CHG) were characterized and studied systematically. The results indicated that HAP nanoparticles was fixed and distributed evenly in CG. The maximum decomposition temperature increased gradually from 334.6 °C for CG to 346.7 °C for CHG, and the compressive strength increased gradually from 100 kPa for CG to 570 kPa for CHG with the increase of HAP content, respectively. Moreover, the adsorption capacity (qe) value of CHG towards Cu2+ could reach more than 300% higher than that of CG. As a potential absorbent, CHG exhibited relatively good recyclability of more than 78% after 10 cycles. Therefore, the introduction of HAP improved the properties of CG greatly, showing wide potential applications.

3.
Food Chem ; 360: 129922, 2021 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-33965711

RESUMO

Starch based food packaging has been receiving increasing attention. However, the inherent poor properties of starch restrict its practical applications in the versatile material science field. In this study, a fast, simple, and environmentally friendly route to construct polyfunctional starch/tea polyphenols nanofibrous films (STNFs) by one-step temperature-assisted electrospinning was developed. The effects of introduction of tea polyphenols (TP) on the mechanical and antioxidant activity of STNFs were comprehensively investigated. Results of ABTS·+ free radical scavenging assay showed that the antioxidant activity of STNFs was endowed by addition of TP with optimum mechanical properties confirmed by tensile test. More interestingly, the hydrophobicity of STNFs was improved dramatically with increasing cross-linking time as indicated by water contact angle (WCA) measurement showing no effect on the antioxidant activity of the films. The results of this work offer a major step forward to promote functional starch-based materials for sustainable application in food packaging.


Assuntos
Antioxidantes/química , Embalagem de Alimentos/instrumentação , Polifenóis/química , Amido/química , Interações Hidrofóbicas e Hidrofílicas , Nanofibras , Permeabilidade , Chá/química , Água/química
4.
Nanotechnology ; 32(6): 065701, 2021 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-33210616

RESUMO

In recent years, the pyrolysis of microbial biomasses that adsorb various metal ions has enabled the preparation of carbon-based polymetallic nanomaterials with excellent electrocatalytic and electrical energy storage properties. However, the preparation of ozone catalysts by this technique and the corresponding catalytic oxidation mechanism are still unclear. In this study, an Escherichia coli strain (BL21) was used for tetra-metal (Cu, Fe, Mn and Al) absorption and the obtained microbial biomass was pyrolyzed under the protection of a nitrogen flow at 700 °C and activated at 900 °C to prepare a microbial-char-based tetra-metal ozone catalyst (MCOC). This was used to degrade phenol and coking wastewater and exhibited a strong catalytic capability for coking wastewater, whose chemical oxygen demand removal efficiency of 70.86% is 16.7% higher than that of pure ozone and 14.67%, 7.21% and 3.58% higher than that of three commercial catalysts, respectively. It also improved the efficiency of ozonation for phenol by 33%. The MCOC was characterized by x-ray diffraction, x-ray photoelectron spectroscopy, scanning electron microscopy-energy-dispersive spectroscopy, transmission electron microscopy and other methods. The results demonstrated that the spherical metal nanoparticles had sizes ranging from 3 nm to 7 nm and that crystals of Fe2O3 and Fe3P were observed. The study showed that the MCOC promoted the production of more hydroxyl radicals and superoxides from ozone, which attack organics. The oxygen vacancies of the catalyst were also investigated. It was proved that the Lewis acid sites on the surface of metal oxides are the active centers of ozone decomposition. Therefore, this work provides a new method for the synthesis of multi-metal nanocomposites and expands the application of biosynthetic nanomaterials.


Assuntos
Escherichia coli/química , Nanopartículas Metálicas/química , Ozônio/química , Eliminação de Resíduos Líquidos/métodos , Análise da Demanda Biológica de Oxigênio , Catálise , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Oxigênio/química , Fenóis/química , Espectroscopia Fotoeletrônica , Pirólise , Espectroscopia de Infravermelho com Transformada de Fourier , Análise Espectral Raman , Águas Residuárias/química
5.
Huan Jing Ke Xue ; 42(1): 30-37, 2021 Jan 08.
Artigo em Chinês | MEDLINE | ID: mdl-33372454

RESUMO

In order to explore the characteristics of PM2.5 and water-soluble ions in Shenyang in winter, the URG-9000D online monitoring system was used to continuously sample PM2.5 and gas components during 2018. The results indicated that the average concentration of PM2.5 in Shenyang during the sampling period was 80.67 µg·m-3, and the total water-soluble ion concentration ranged from 2.68 to 132.79 µg·m-3. Compared with clean days, the proportion of NO3-, SO42-, and NH4+ (SNA) in polluted days increased significantly, reached 43.7% of PM2.5. The rapid accumulation of SO2 in a short period of time made atmospheric PM2.5 explosively increase in Shenyang in winter. A Pearson correlation analysis showed that the correlation coefficients of SNA, Cl-, and PM2.5 were all above 0.78, indicating that the main contribution components of winter PM2.5 in Shenyang were SNA and Cl-. The apportionment of PMF sources indicated that the sources of pollutants in winter in Shenyang mainly included secondary reaction sources, coal and biomass combustion sources, and dust sources.

6.
ACS Omega ; 5(46): 29896-29902, 2020 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-33251425

RESUMO

Improving the electrochemical performance of biomass-derived carbon electrode-active materials for supercapacitor applications has recently attracted considerable attention. Herein, we develop hybrid electrode materials from rice-husk-derived porous carbon (RH-C) materials and ß-Ni(OH)2 via a facile solid-state reaction strategy comprising two steps. The prepared RH-C/Ni(OH)2 (C-Ni) was investigated using scanning electron microscopy (SEM) (energy-dispersive X-ray spectrometer (EDS)), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD) to acquire the physical and chemical information, which was used to demonstrate the successful fabrication of C-Ni. Thermogravimetric analysis (TGA) measurement results confirmed that the thermal stability of C-Ni changed due to the presence of Ni(OH)2. As expected, C-Ni possesses a high capacitance of ∼952 F/g at a current density of 1.0 A/g. This result is higher than that of pure biomass-based carbon materials under the three-electrode system. This facile preparation method, which was used to synthesize the electrode-active materials, can extend to the value-added utility of other waste biomass materials as high-performing supercapacitor electrodes for energy storage applications.

7.
Proc Natl Acad Sci U S A ; 117(40): 24757-24763, 2020 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-32958681

RESUMO

We discuss the current state of knowledge of stable homotopy groups of spheres. We describe a computational method using motivic homotopy theory, viewed as a deformation of classical homotopy theory. This yields a streamlined computation of the first 61 stable homotopy groups and gives information about the stable homotopy groups in dimensions 62 through 90. As an application, we determine the groups of homotopy spheres that classify smooth structures on spheres through dimension 90, except for dimension 4. The method relies more heavily on machine computations than previous methods and is therefore less prone to error. The main mathematical tool is the Adams spectral sequence.

8.
Biotechnol Biofuels ; 13: 162, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32973923

RESUMO

Background: Extracellular electron transfer (EET) is essential in improving the power generation performance of electrochemically active bacteria (EAB) in microbial fuel cells (MFCs). Currently, the EET mechanisms of dissimilatory metal-reducing (DMR) model bacteria Shewanella oneidensis and Geobacter sulfurreducens have been thoroughly studied. Klebsiella has also been proved to be an EAB capable of EET, but the EET mechanism has not been perfected. This study investigated the effects of biofilm transfer and electron mediators transfer on Klebsiella quasipneumoniae sp. 203 electricity generation performance in MFCs. Results: Herein, we covered the anode of MFC with a layer of microfiltration membrane to block the effect of the biofilm mechanism, and then explore the EET of the electron mediator mechanism of K. quasipneumoniae sp. 203 and electricity generation performance. In the absence of short-range electron transfer, we found that K. quasipneumoniae sp. 203 can still produce a certain power generation performance, and coated-MFC reached 40.26 mW/m2 at a current density of 770.9 mA/m2, whereas the uncoated-MFC reached 90.69 mW/m2 at a current density of 1224.49 mA/m2. The difference in the electricity generation performance between coated-MFC and uncoated-MFC was probably due to the microfiltration membrane covered in anode, which inhibited the growth of EAB on the anode. Therefore, we speculated that K. quasipneumoniae sp. 203 can also perform EET through the biofilm mechanism. The protein content, the integrity of biofilm and the biofilm activity all proved that the difference in the electricity generation performance between coated-MFC and uncoated-MFC was due to the extremely little biomass of the anode biofilm. To further verify the effect of electron mediators on electricity generation performance of MFCs, 10 µM 2,6-DTBBQ, 2,6-DTBHQ and DHNA were added to coated-MFC and uncoated-MFC. Combining the time-voltage curve and CV curve, we found that 2,6-DTBBQ and 2,6-DTBHQ had high electrocatalytic activity toward the redox reaction of K. quasipneumoniae sp. 203-inoculated MFCs. It was also speculated that K. quasipneumoniae sp. 203 produced 2,6-DTBHQ and 2,6-DTBBQ. Conclusions: To the best of our knowledge, the three modes of EET did not exist separately. K. quasipneumoniae sp.203 will adopt the corresponding electron transfer mode or multiple ways to realize EET according to the living environment to improve electricity generation performance.

9.
Biomed Pharmacother ; 129: 110489, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32768969

RESUMO

Liver injury is a common complication of severe heat stroke (HS). Extracellular vesicles (EVs) are part of a novel pathway mediating intercellular communication. Whether EVs are involved in the pathogenesis underlying HS-induced liver injury remains unknown. Here, we explored the role of hepatocyte EVs in HS-induced liver injury and their protein regulation patterns after HS induction. Isobaric tags for relative and absolute quantification technology (iTRAQ) and liquid chromatography-tandem mass spectrometry analysis identified changes in the proteomic profiles of hepatocyte-derived heat-stroked EVs, and we identified 53 up-regulated proteins. Bioinformatics analysis verified that the regulation of programmed cell death was the most significant altered pathway. To clarify the effect of HS hepatocyte-derived EVs in inducing hepatocyte-programmed death and injury, they were added to recipient hepatocytes and injected into mice. This treatment significantly induced the synthesis of apoptosis (caspase-3/8) and necroptosis-associated proteins [receptor-interacting protein 1 (RIP1), RIP3, and mixed lineage kinase domain-like protein]; moreover, it increased the numbers of apoptotic and necroptotic cells in hepatocytes and liver tissues and increased the levels of biochemical liver injury markers (alanine aminotransferase, aspartate aminotransferase, and lactate dehydrogenase). Our study is the first comprehensive analysis of the hepatocyte-derived heat-stroked EV proteome confirming the induction of liver injury by Evs. We provide a novel explanation for the pathological mechanism underlying HS-induced liver injury.


Assuntos
Proteínas Reguladoras de Apoptose/metabolismo , Apoptose , Vesículas Extracelulares/metabolismo , Transtornos de Estresse por Calor/metabolismo , Hepatócitos/metabolismo , Necroptose , Proteômica , Animais , Cromatografia Líquida de Alta Pressão , Modelos Animais de Doenças , Vesículas Extracelulares/patologia , Transtornos de Estresse por Calor/patologia , Resposta ao Choque Térmico , Células Hep G2 , Hepatócitos/patologia , Humanos , Masculino , Camundongos Endogâmicos C57BL , Transdução de Sinais , Espectrometria de Massas em Tandem
10.
Materials (Basel) ; 13(9)2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32369995

RESUMO

In this report, poly(lactic acid) (PLA) and Poly(butylene adipate-co-terephthalate) (PBAT) with three kinds of compatibilizers were melt blended under intensive shear flow. A self-made parallel three-screw extruder was developed to generate such flow during the process. Mechanical properties, chemical reactions among PLA, PBAT and compatibilizers, rheological behavior and morphology were investigated. The mechanical tests showed that the notched impact strength of super-tough composite with 10 wt% EGMA is about 20 times than that of pure PLA. The Fourier transform infrared spectroscopy (FT-IR) results showed that the epoxy functional groups or maleic anhydride functional groups of KT-20, KT-915 and EGMA reacted with the hydroxyl groups of PLA or PBAT macromolecules, resulting in a bridge of PLA and PBAT. About rheological properties, the tan δ-angular frequency curves and the η''- η' curves confirmed the chemical reactions mentioned above and indicated better compatibility of η''- η' between PLA and PBAT, respectively. Meanwhile, the loss modulus and storage modulus-angular frequency curves demonstrated the discrepancy of different compatibilizer components. In particular, from scanning electron microscopy (SEM) images, it can be seen that the phase size and dispersion uniformity of PBAT adjusted by compatibilizer, corresponding to better compatibility that is described in the η''- η' curves. The approach for producing super-tough PLA/PBAT/compatibilizer by intensive shear flow provides a viable direction for further improving PLA performance.

11.
ACS Omega ; 5(15): 8839-8846, 2020 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-32337446

RESUMO

The preparation of reusable and eco-friendly materials from renewable biomass resources such as cellulose is an inevitable choice for sustainable development. In this work, cellulose was dissolved in 7 wt % NaOH/12 wt % urea aqueous solution at -12 °C with rapid stirring. Cellulose microspheres (Cels) were fabricated by a sol-gel transition method. Subsequently, novel magnetic Ag-Fe3O4 nanoparticles (NPs) supported on cellulose microspheres were successfully constructed by an in situ one-pot synthesis. The magnetic cellulose microspheres (MCels) displayed a spherical shape with mesoporous structure and had a narrow particle size distribution (10-20 µm). Many nanopores with a pore diameter of 5-40 nm were observed in MCels. The Ag-Fe3O4 NPs were immobilized by anchoring with the hydroxyl groups on the surface of Cels. MCels were applied as a microreactor to evaluate their catalytic activities. 4-Nitrophenol (4-NP) could be reduced to 4-aminophenol (4-AP) in 5 min, catalyzed by MCels. Moreover, the magnetic microspheres exhibited a small hysteresis loop and low coercivity. Thus, MCels could be quickly gathered in water under a magnetic field in 10 s, as well as almost 9 cycle times, maintaining relatively high catalytic activity. In this work, cellulose matrix as the catalyst support could be biodegraded completely in the environment. It provided a green process for the utilization of biomass in nanocatalytic applications.

12.
J Cell Physiol ; 235(5): 4980, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32048739
13.
Int J Biol Macromol ; 155: 1245-1251, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-31726152

RESUMO

Bulk homogeneous polyelectrolyte complex hydrogels (PCH) are difficult to prepare due to the flocculation effect between polyelectrolytes with opposite charges. Herein, novel chitosan/sodium polyacrylate (PAAS) polyelectrolyte complex hydrogels (CPG) were fabricated successfully by cross-linking chitosan and PAAS with epichlorohydrin (ECH) through inhibiting protonation effect of chitosan in alkali/urea aqueous solution. The swelling behaviors of CPG were studied systematically in different solutions. The equilibrium swelling ratio of chitosan hydrogel in water increased dramatically from 46.3 to 404.8 g/g by the introduction of PAAS. CPG exhibited different swelling ratios towards different pH solutions, physiological solutions and salt solutions with different concentrations, showing obvious smart responsive properties. Moreover, CPG hydrogels exhibited relatively high compressive strength, good biocompatibility and in vitro biodegradability. Therefore, this work provided a novel PCH and shed light on the fabrication of other PCH, showing potential applications in the fields of agriculture, foods, tissue engineering and drug delivery.


Assuntos
Resinas Acrílicas/química , Materiais Biocompatíveis/química , Quitosana/química , Epicloroidrina/química , Hidrogéis/química , Reagentes para Ligações Cruzadas/química , Concentração de Íons de Hidrogênio
14.
Huan Jing Ke Xue ; 40(11): 4862-4869, 2019 Nov 08.
Artigo em Chinês | MEDLINE | ID: mdl-31854552

RESUMO

According to activity level data of various ammonia emission sources in Jiangsu Province, using a reasonable inventory calculation method and emission factor, an ammonia emission inventory in Jiangsu Province from 2013 to 2017 was established, and the trend of anthropogenic ammonia emissions over these years was analyzed. The distribution characteristics of anthropogenic ammonia emissions and emission intensity in Jiangsu Province were analyzed using ArcGIS software. The results showed that the ammonia emissions in Jiangsu Province decreased from 624.84 kt in 2013 to 562.47 kt in 2017 with an average annual rate of decline of approximately 2.6%. Agricultural has always been the most important source of ammonia emissions in Jiangsu Province and accounted for 82.4% of the total ammonia emissions in 2017. Laying hens are the largest source of ammonia emissions from livestock and poultry sources, accounting for 49.3% of the ammonia emissions from livestock and poultry. The average ammonia emission intensity in Jiangsu Province was 5.3 t·km-2 in 2017. Yancheng and Xuzhou are two cities with the largest anthropogenic ammonia emissions and emission intensity in Jiangsu Province. Zhenjiang City has the lowest ammonia emission and emission intensity.

15.
Hum Mol Genet ; 28(R2): R187-R196, 2019 11 21.
Artigo em Inglês | MEDLINE | ID: mdl-31595953

RESUMO

Recent work on the biophysics of proteins with low complexity, intrinsically disordered domains that have the capacity to form biological condensates has profoundly altered the concepts about the pathogenesis of inherited and sporadic neurodegenerative disorders associated with pathological accumulation of these proteins. In the present review, we use the FUS, TDP-43 and A11 proteins as examples to illustrate how missense mutations and aberrant post-translational modifications of these proteins cause amyotrophic lateral sclerosis (ALS) and fronto-temporal lobar degeneration (FTLD).


Assuntos
Esclerose Amiotrófica Lateral/genética , Anexinas/genética , Proteínas de Ligação a DNA/genética , Degeneração Lobar Frontotemporal/genética , Proteína FUS de Ligação a RNA/química , Lobo Temporal/fisiopatologia , Anexinas/química , Anexinas/metabolismo , Transporte Biológico/genética , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/metabolismo , Humanos , Membranas Intracelulares/química , Membranas Intracelulares/metabolismo , Mutação de Sentido Incorreto , Doenças Neurodegenerativas/fisiopatologia , Neurônios/química , Neurônios/metabolismo , Processamento de Proteína Pós-Traducional/genética , Proteína FUS de Ligação a RNA/genética , Proteína FUS de Ligação a RNA/metabolismo
16.
Int J Biol Macromol ; 141: 529-537, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31493457

RESUMO

Selenium is an essential trace element in human body, and kappa-selenocarrageenan (Se-car) is an organic source of selenium supplement. To further utilize Se-car in food packaging, biotherapy or biosensor, the molecular information of Se-car was characterized here and multi-functional Ag NPs synthesized by Se-car were fabricated. Results of GPC-MALLS, FTIR, potentiometric titration, and intrinsic viscosity showed that Se-car was polymerized by nearly 22 basic units of disaccharide. Sixty-four percentage of sulfated groups (SO42-) in carrageenan was replaced by selenium acid (SeO32-), which belonged to weak acid resulting from a gradually decrease of ζ-potential with acidity process to pH 1.0. Besides, the capacity of biosynthesis silver nanoparticles (Ag NPs) by Se-car was studied and it made a comparison with κ-carrageenan. Results exhibited that Se-car could serve as an efficient reducing and capping agent for Ag NPs fabrication (remarked as Se-car@Ag). The kapp of Se-car@Ag NPs for catalyzing 4-NP degradation was 2.14 × 10-2 s-1. Antibacterial test revealed Se-car@Ag had an ability to inhibit the growth of Escherichia coli and Staphylococcus aureus. To combine the selenium health benefit and functional metal nanoparticles, Se-car@Ag might have potential applications in multiple areas like medicine, disease diagnostic, and drug delivery.


Assuntos
Antibacterianos , Carragenina/química , Escherichia coli/crescimento & desenvolvimento , Química Verde , Nanopartículas Metálicas/química , Compostos Organosselênicos/química , Prata , Staphylococcus aureus/crescimento & desenvolvimento , Antibacterianos/síntese química , Antibacterianos/química , Antibacterianos/farmacologia , Prata/química , Prata/farmacologia
17.
Cell ; 179(1): 147-164.e20, 2019 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-31539493

RESUMO

Long-distance RNA transport enables local protein synthesis at metabolically-active sites distant from the nucleus. This process ensures an appropriate spatial organization of proteins, vital to polarized cells such as neurons. Here, we present a mechanism for RNA transport in which RNA granules "hitchhike" on moving lysosomes. In vitro biophysical modeling, live-cell microscopy, and unbiased proximity labeling proteomics reveal that annexin A11 (ANXA11), an RNA granule-associated phosphoinositide-binding protein, acts as a molecular tether between RNA granules and lysosomes. ANXA11 possesses an N-terminal low complexity domain, facilitating its phase separation into membraneless RNA granules, and a C-terminal membrane binding domain, enabling interactions with lysosomes. RNA granule transport requires ANXA11, and amyotrophic lateral sclerosis (ALS)-associated mutations in ANXA11 impair RNA granule transport by disrupting their interactions with lysosomes. Thus, ANXA11 mediates neuronal RNA transport by tethering RNA granules to actively-transported lysosomes, performing a critical cellular function that is disrupted in ALS.


Assuntos
Anexinas/metabolismo , Transporte Axonal/fisiologia , Grânulos Citoplasmáticos/metabolismo , Lisossomos/metabolismo , RNA/metabolismo , Esclerose Amiotrófica Lateral/metabolismo , Animais , Animais Geneticamente Modificados , Anexinas/genética , Axônios/metabolismo , Linhagem Celular Tumoral , Feminino , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Masculino , Mutação , Ligação Proteica , Ratos/embriologia , Ratos Sprague-Dawley , Transfecção , Peixe-Zebra
18.
Materials (Basel) ; 12(15)2019 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-31344891

RESUMO

In this study, the in-situ compatibilization reaction between recycled acrylonitrile-butadiene-styrene copolymer (rABS) and functional styrene-ethylene-butylene-styrene block maleic anhydride (SEBS-g-MAH) was confirmed, which contributed to the toughening phenomenon of rABS, especially the notched impact strength. As mechanical test that manifested, the rABS/SEBS-g-MAH blends are stronger and more ductile than the rABS/SEBS blends. Prominently, the former has great advantage over the latter in terms of improving the impact performance. Scanning electron microscope (SEM) images showed that the compatible segments that were generated by reaction not only improve the interface adhesion of rABS/SEBS-g-MAH blends but also promote the evolution of co-continuous structures, which can be evidently observed after etching. Furthermore, the SEM micrographs of tensile fracture surfaces indicated that the formation of the co-continuous phase and the improvement of interface adhesion are the most profound reasons for the excellent tensile properties of the rABS/SEBS-g-MAH blends. The impact fracture surface revealed that two-phase interface affects crack propagation and shear yielding absorbs more impact energy than simple interface debonding does at higher deformation rates. Meanwhile, rheological analysis demonstrated that the complex viscosity of the rABS/SEBS-g-MAH (80/20 wt%) blend with a co-continuous structure exhibits a maximum positive deviation at low frequencies from the theoretical value calculated using the rule of logarithmic sum, which indicated a connection between co-continuous structure and complex viscosity. In addition, the storage modulus vs. loss modulus curves of the blends revealed that the viscoelastic behavior of rABS/SEBS-g-MAH blends is very similar to that of rABS.

19.
Cell Death Dis ; 10(7): 482, 2019 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-31209200

RESUMO

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

20.
Polymers (Basel) ; 11(3)2019 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-30960532

RESUMO

Tannin/cellulose microspheres (T/C) were successfully prepared via a facile homogeneous reaction in a water/oil (W/O) emulsion for removing Pb(II) ions from aqueous solution. The structure of the microspheres was characterized by scanning electron microscopy (SEM), Fourier-transform infrared (FTIR) spectroscopy, and a zeta potential test. The effects of pH, adsorbent dosage, contact time, and temperature on adsorption ability were investigated. The results showed that T/C microspheres could combine Pb(II)ions via electrostatic attractions and physical adsorption. Adsorption kinetics could be better described by the pseudo-second-order kinetic model. The adsorption behaviors were in agreement with the Langmuir adsorption isotherm model with a fitting correlation coefficient of 0.9992. The maximum adsorption capacity was 23.75 mg/g from the Langmuir isotherm evaluation at 308K with an initial pH of 5. The results suggested that tannin/cellulose microspheres could be a low-cost and effective adsorbent for removing Pb(II) ions from aqueous solution.

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