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1.
Angew Chem Int Ed Engl ; 63(13): e202318632, 2024 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-38327029

RESUMO

Liposomes serve as promising and versatile vehicles for drug delivery. Tracking these nanosized vesicles, particularly in vivo, is crucial for understanding their pharmacokinetics. This study introduces the design and synthesis of three new conjugated electrolyte (CE) molecules, which emit in the second near-infrared window (NIR-II), facilitating deeper tissue penetration. Additionally, these CEs, acting as biomimetics of lipid bilayers, demonstrate superior compatibility with lipid membranes compared to commonly used carbocyanine dyes like DiR. To counteract the aggregation-caused quenching effect, CEs employ a twisted backbone, as such their fluorescence intensities can effectively enhance after a fluorophore multimerization strategy. Notably, a "passive" method was employed to integrate CEs into liposomes during the liposome formation, and membrane incorporation efficiency was significantly promoted to nearly 100%. To validate the in vivo tracking capability, the CE-containing liposomes were functionalized with cyclic arginine-glycine-aspartic acid (cRGD) peptides, serving as tumor-targeting ligands. Clear fluorescent images visualizing tumor site in living mice were captured by collecting the NIR-II emission. Uniquely, these CEs exhibit additional emission peak in visible region, enabling in vitro subcellular analysis using routine confocal microscopy. These results underscore the potential of CEs as a new-generation of membrane-targeting probes to facilitate the liposome-based medicine research.


Assuntos
Lipossomos , Neoplasias , Camundongos , Animais , Lipossomos/química , Bicamadas Lipídicas/química , Biomimética , Sistemas de Liberação de Medicamentos , Corantes Fluorescentes/química
2.
Med Sci Monit ; 29: e940134, 2023 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-37461206

RESUMO

BACKGROUND Percutaneous vertebral augmentation is the mainstream treatment of osteoporotic vertebral compression fracture (OVCF). New vertebral compression fracture (NVCF) after percutaneous vertebral augmentation may be an issue that cannot be ignored. Nevertheless, the risk factors for NVCF are still uncertain. This research aimed to study the risk factors for NVCF after percutaneous vertebral augmentation. MATERIAL AND METHODS All patients who underwent percutaneous vertebral augmentation for OVCF from January 2019 to December 2020 were enrolled in the study. These patients were divided into NVCF and control groups according to whether they had NVCF. The covariates including sex, age, BMI, diabetes, hypertension, smoking, alcohol, fracture level, surgical method, cement leakage, cement volume, preoperative anterior vertebral height ratio, and Hounsfield unit (HU) value were reviewed. Univariate and multivariate analyses were performed to identify risk factors. RESULTS A total of 279 patients were included in this study, of which 47 had NVCF after percutaneous vertebral augmentation. Univariate analysis demonstrated that there were significant differences in age (OR=1.040, 95% CI=1.003-1.078, P=0.033), BMI (OR=0.844, 95% CI=0.758-0.939, P=0.002) and HU value (OR=0.945, 95% CI=0.929-0.962, P<0.001) between the 2 groups. Multivariate regression analysis revealed that HU value (OR=0.942, 95% CI=0.924-0.960, P<0.001) were independent risk factor for NVCF after percutaneous vertebral augmentation. CONCLUSIONS Hounsfield unit value was an independent risk factor for new vertebral compression fracture after percutaneous vertebral augmentation, whereas age and BMI were not.


Assuntos
Fraturas por Compressão , Cifoplastia , Fraturas por Osteoporose , Fraturas da Coluna Vertebral , Vertebroplastia , Humanos , Fraturas da Coluna Vertebral/etiologia , Fraturas da Coluna Vertebral/cirurgia , Fraturas da Coluna Vertebral/tratamento farmacológico , Fraturas por Compressão/cirurgia , Fraturas por Compressão/etiologia , Estudos Retrospectivos , Cifoplastia/efeitos adversos , Cifoplastia/métodos , Resultado do Tratamento , Vertebroplastia/efeitos adversos , Vertebroplastia/métodos , Cimentos Ósseos/efeitos adversos , Fatores de Risco , Fraturas por Osteoporose/cirurgia , Fraturas por Osteoporose/etiologia
3.
Int J Mol Sci ; 24(9)2023 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-37175413

RESUMO

Biomaterials carrying recombinant human bone morphogenetic protein 2 (BMP2) have been developed to enhance bone regeneration in the treatment of bone defects. However, various reports have shown that in the bone repair microenvironment, fibroblasts can inhibit BMP2-induced osteogenic differentiation in mesenchymal stem cells (MSCs). Thus, factors that can target fibroblasts and improve BMP2-mediated osteogenesis should be explored. In this project, we focused on whether or not an inhibitor of the NF-κB signaling pathway, QNZ (EVP4593), could play a synergistic role with BMP2 in osteogenesis by regulating the activity of fibroblasts. The roles of QNZ in regulating the proliferation and migration of fibroblasts were examined. In addition, the effect of QNZ combined with BMP2 on the osteogenic differentiation of MSCs was evaluated both in vitro and in vivo. Furthermore, the detailed mechanisms by which QNZ improved BMP2-mediated osteogenesis through the modulation of fibroblasts were analyzed and revealed. Interestingly, we found that QNZ inhibited the proliferation and migration of fibroblasts. Thus, QNZ could relieve the inhibitory effects of fibroblasts on the homing and osteogenic differentiation of mesenchymal stem cells. Furthermore, biomaterials carrying both QNZ and BMP2 showed better osteoinductivity than did those carrying BMP2 alone both in vitro and in vivo. It was found that the mechanism of QNZ involved reactivating YAP activity in mesenchymal stem cells, which was inhibited by fibroblasts. Taken together, our results suggest that QNZ may be a candidate factor for assisting BMP2 in inducing osteogenesis. The combined application of QNZ and BMP2 in biomaterials may be promising for the treatment of bone defects in the future.


Assuntos
Células-Tronco Mesenquimais , Osteogênese , Humanos , NF-kappa B/metabolismo , Proteínas de Sinalização YAP , Proteína Morfogenética Óssea 2/farmacologia , Proteína Morfogenética Óssea 2/metabolismo , Diferenciação Celular , Células-Tronco Mesenquimais/metabolismo , Transdução de Sinais , Materiais Biocompatíveis/farmacologia
4.
Bull Environ Contam Toxicol ; 109(2): 323-331, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35715702

RESUMO

We investigated the occurrence of Cd, Cr, Cu, Ni, Pb and Zn in 28 road dust samples collected across China from June to August, 2020. The mean concentrations of Cd, Cr, Cu, Ni, Pb and Zn were 3.16, 24.2, 27.4, 10.4, 49.8 and 608 mg·kg- 1, respectively. The mean levels of Cd and Zn exceeded the Chinese background values by 32.6- and 8.2- fold. Cd, Ni mainly distributed in southern China, whereas Cu, Pb and Zn mainly distributed in central China. Higher concentrations of Cd, Cr, Cu and Pb were found in road dusts from urban areas than those from rural areas. Cu and Ni mainly came from natural sources; Pb and Cd mainly originated from industrial emissions and vehicle exhaust. Hand-mouth ingestion was the most common exposure pathway for both adults and children, followed by dermal contact and inhalation. Pb was found to be the highest risk element via ingestion. No significant non-carcinogenic risks and carcinogenic risks were found for local residents.


Assuntos
Poeira , Metais Pesados , Adulto , Cádmio , Criança , China , Cidades , Poeira/análise , Exposição Ambiental/análise , Monitoramento Ambiental , Humanos , Chumbo , Metais Pesados/análise , Medição de Risco
5.
BMC Anesthesiol ; 21(1): 237, 2021 10 02.
Artigo em Inglês | MEDLINE | ID: mdl-34600487

RESUMO

BACKGROUND: Uvulopalatopharyngoplasty(UPPP) is the most prevalent surgical treatment of obstructive sleep apnea, but postoperative pharyngeal pain may affect patient comfort. The enhanced recovery after surgery pathway has been proved beneficial to many types of surgery but not to UPPP yet. The aim of this pilot study was to preliminarily standrize an enhanced recovery after surgery protocol for UPPP, to assess whether it has positive effects on reducing postoperative pharyngeal pain and improving patient comfort, and to test its feasibility for an international multicentre study. METHODS: This randomised controlled study analysed 116 patients with obstructive sleep apnoea (OSA) who were undergoing UPPP in a single tertiary care hospital. They were randomly divided according to treatment: the ERAS group (those who received ERAS treatment) and the control group (those who received traditional treatment). Ninety-five patients completed the assessment (ERAS group, 59 patients; control group, 36 patients). Pharyngeal pain and patient comfort were evaluated using a visual analogue scale (VAS) at 30 min and at 6, 12, 24 and 48 h after UPPP. Complications, hospitalisation duration, and hospital cost were recorded. RESULTS: The VAS scores for resting pain and swallowing pain were significantly lower in the ERAS group than those in the control group at 30 min and at 6, 12, 24 and 48 h after surgery. Patient comfort was improved in the ERAS group. The hospitalisation duration and cost were comparable between the groups. The incidence of complications showed an increasing trend in the ERAS group. CONCLUSION: The ERAS protocol significantly relieved pharyngeal pain after UPPP and improved comfort in patients with OSA, which showed the prospect for an larger study. Meanwhile a potential increase of post-operative complications in the ERAS group should be noticed. TRIAL REGISTRATION: Chinese Clinical Trial Registry (23/09/2018, ChiCTR1800018537 ).


Assuntos
Analgesia/métodos , Recuperação Pós-Cirúrgica Melhorada , Palato/cirurgia , Conforto do Paciente/estatística & dados numéricos , Faringe/cirurgia , Complicações Pós-Operatórias/epidemiologia , Úvula/cirurgia , Adulto , China/epidemiologia , Feminino , Humanos , Masculino , Projetos Piloto , Estudos Prospectivos
6.
Cell Tissue Bank ; 22(3): 419-430, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34115245

RESUMO

Decellularized nerve extracellular matrix (NECM) composited with chitosan are moldable materials suitable for spinal cord repair. But the rapid biodegradation of the materials may interrupt neural tissue reconstruction in vivo. To improve the stability of the materials, the materials produced by NECM and chitosan hydrogels were crosslinked by genipine, glutaraldehyde or ultraviolet ray. Physicochemical property, degradation and biocompatibility of materials crosslinked by genipin, glutaraldehyde or ultraviolet ray were evaluated. The scaffold crosslinked by genipin possessed a porous structure, and the porosity ratio was 89.07 + 4.90%, the average diameter of pore was 85.32 + 5.34 µm. The crosslinked degree of the scaffold crosslinked by genipin and glutaraldehyde was 75.13 ± 4.87%, 71.25 ± 5.06% respectively; Uncrosslinked scaffold disintegrated when immerged in distilled water while the scaffold crosslinked by genipin and glutaraldehyde group retained their integrity. The scaffold crosslinked by genipin has better water absorption, water retention and anti-enzymatic hydrolysis ability than the other three groups. Cell cytotoxicity showed that the cytotoxicity of scaffold crosslinked by genipin was lower than that crosslinked by glutaraldehyde. The histocompatibility of scaffold crosslinked by genipin was also better than glutaraldehyde group. More cells grew well in the scaffold crosslinked by genipin when co-cultured with L929 cells. The decellularized nerve extracellular matrix/chitosan scaffold crosslinked by the genipin has good mechanical properties, micro structure and biocompatibility, which is an ideal scaffold for the spinal cord tissue engineering.


Assuntos
Quitosana , Resinas Acrílicas , Materiais Biocompatíveis , Reagentes de Ligações Cruzadas , Matriz Extracelular , Iridoides , Engenharia Tecidual , Alicerces Teciduais
7.
Biomacromolecules ; 21(3): 1254-1263, 2020 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-31976648

RESUMO

We report here the synthesis of a series of ethylene glycol-based triblock copolymers containing a hydrophilic middle segment of poly(ethylene glycol) methyl ether methacrylate (PEGMA) and two temperature-responsive segments of diethylene glycol methyl ether methacrylate (DEGMA) at both ends via the reversible addition-fragmentation chain-transfer (RAFT) polymerization. While the corresponding temperature-responsive homopolymer (PDEGMA) and the diblock copolymer (PDEGMA-b-PPEGMA) could not form a gel, the triblock copolymers (PDEGMA-b-PPEGMA-b-PDEGMA) could form a physical gel at certain concentrations and at temperatures above the lower critical solution temperature (LCST). This sol-gel transition is fully reversible and can be repeated several times. Depending on the chain length of the middle block and two end blocks, a physical gel could be formed at a minimum polymer concentration of 5 wt %. In addition, a mechanically strong gel could be easily formed within 5 s at the maximum concentration of 20 wt % and at a temperature of 37 °C. Considering the good cell compatibility and soft rubbery nature of the triblock copolymers, they can potentially be used as injectable scaffold for cell culture and tissue engineering applications.


Assuntos
Materiais Biocompatíveis , Polietilenoglicóis , Técnicas de Cultura de Células , Hidrogéis , Polímeros , Temperatura
8.
Macromol Rapid Commun ; 40(13): e1900120, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31021506

RESUMO

A wide-bandgap conjugated polymer, PNQx-2F2T, based on a ring-fused unit of quinoxalino[6,5-f ]quinoxaline (NQx), is synthesized for use as electron donor in polymer solar cells (PSCs). The polymer shows intense light absorption in the range from 300 to 740 nm and favorable energy levels of frontier molecular orbitals. The polymer has afforded decent device performance when blended with either fullerene-based acceptor [6,6]-phenyl-C71 -butylric acid methyl ester ([70]PCBM) or non-fullerene acceptor 3,9-bis(2-methylene-(3-(1,1-dicyanomethylene)-indanone-methyl))-5,5,11,11-tetrakis(4-n-hexylphenyl)-dithieno[2,3-d: 2',3'-d']-s-indaceno[1,2-b:5,6-b']dithiophene (IT-M). The highest PCEs of 7.9% and 7.5% have been achieved for [70]PCBM or IT-M based PSCs, respectively. Moreover, the influence of molecular weight of PNQx-2F2T on solar cell performance has been investigated. It is found that fullerene-based devices prefer higher polymer molecular weight, while non-fullerene devices are not susceptible to the molecular weight of PNQx-2F2T. The device results are extensively explained by electrical and morphological characterizations. This work not only evidences the potential of NQx for constructing high-performance photovoltaic polymers but also demonstrates a useful structure-performance relationship for efficiency enhancement of non-fullerene PSCs via the development of new conjugated polymers.


Assuntos
Fulerenos/química , Polímeros/química , Quinoxalinas/química , Energia Solar , Estrutura Molecular
9.
Macromol Rapid Commun ; 39(14): e1700765, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29436082

RESUMO

The design and synthesis of three n-type conjugated polymers based on a naphthalene diimide-thiophene skeleton are presented. The control polymer, PNDI-2HD, has two identical 2-hexyldecyl side chains, and the other polymers have different alkyl side chains; PNDI-EHDT has a 2-ethylhexyl and a 2-decyltetradecyl side chain, and PNDI-BOOD has a 2-butyloctyl and a 2-octyldodecyl side chain. These copolymers with different alkyl side chains exhibit higher melting and crystallization temperatures, and stronger aggregation in solution, than the control copolymer PNDI-2HD that has the same side chain. Polymer solar cells based on the electron-donating copolymer PTB7-Th and these novel copolymers exhibit nearly the same open-circuit voltage of 0.77 V. Devices based on the copolymer PNDI-BOOD with different side chains have a power-conversion efficiency of up to 6.89%, which is much higher than the 4.30% obtained with the symmetric PNDI-2HD. This improvement can be attributed to the improved charge-carrier mobility and the formation of favorable film morphology. These observations suggest that the molecular design strategy of incorporating different side chains can provide a new and promising approach to developing n-type conjugated polymers.


Assuntos
Imidas/química , Naftalenos/química , Polímeros/química , Energia Solar , Elétrons , Estrutura Molecular , Tiofenos/química
10.
Macromol Rapid Commun ; 38(14)2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28485819

RESUMO

Variations in the open-circuit voltage (Voc ) of ternary organic solar cells are systematically investigated. The initial study of these devices consists of two electron-donating oligomers, S2 (two units) and S7 (seven units), and the electron-accepting [6,6]-phenyl C71 butyric acid methyl ester (PC71 BM) and reveals that the Voc is continuously tunable due to the changing energy of the charge transfer state (Ect ) of the active layers. Further investigation suggests that Voc is also continuously tunable upon change in Ect in a ternary blend system that consists of S2 and its corresponding polymer (P11):PC71 BM. It is interesting to note that higher power conversion efficiencies can be obtained for both S2:S7:PC71 BM and S2:P11:PC71 BM ternary systems compared with their binary systems, which can be ascribed to an improved Voc due to the higher Ect and an improved fill factor due to the improved film morphology upon the incorporation of S2. These findings provide a new guideline for the future design of conjugated polymers for achieving higher performance of ternary organic solar cells.


Assuntos
Fulerenos/química , Polímeros/química , Energia Solar , Fotoquímica , Luz Solar
11.
Macromol Rapid Commun ; 38(4)2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28045218

RESUMO

The transition-metal catalyzed and metal-free click polymerizations have been developed as powerful tools for the construction of functional polymers with linear and hyperbranched structures. The latter provides a thorough solution for the completely removing metallic residues from the products encountered in the former. Compared to the activated alkyne-azide metal-free click polymerization, the activated azide-alkyne one is rarely studied. In this Communication, a perfluorophenyl-activated azide of hexane-1,6-diyl-bis(4-azido-2,3,5,6-tetrafluorobenzoate) is rationally designed and facilely prepared. Through systematical optimization of the reaction conditions, an efficient metal-free perfluorophenylazide-alkyne polycycloaddition is established, and polytriazoles with high molecular weights (up to 166 000) and excellent solubility are obtained in excellent yields (up to 93%) under mild reaction conditions. Interestingly, the regioselectivity of the reaction could be fine-tuned by the solvents and diyne monomers. Therefore, this work provides not only a powerful tool for the preparation of functional polytriazoles, but also an attractive method for fine-tuning their regioregularity.


Assuntos
Alcinos/química , Azidas/química , Reação de Cicloadição , Polimerização , Polímeros/síntese química , Triazóis/síntese química , Química Click , Estrutura Molecular , Polímeros/química , Estereoisomerismo , Triazóis/química
12.
World J Microbiol Biotechnol ; 33(9): 176, 2017 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-28905232

RESUMO

Immobilized cells of Bacillus subtilis HLZ-68 were used to produce D-alanine from DL-alanine by asymmetric degradation. Different compounds such as polyvinyl alcohol and calcium alginate were employed for immobilizing the B. subtilis HLZ-68 cells, and the results showed that cells immobilized using a mixture of these two compounds presented higher L-alanine degradation activity, when compared with free cells. Subsequently, the effects of different concentrations of polyvinyl alcohol and calcium alginate on L-alanine consumption were examined. Maximum L-alanine degradation was exhibited by cells immobilized with 8% (w/v) polyvinyl alcohol and 2% (w/v) calcium alginate. Addition of 400 g of DL-alanine (200 g at the beginning of the reaction and 200 g after 30 h of incubation) into the reaction solution at 30 °C, pH 6.0, aeration of 1.0 vvm, and agitation of 400 rpm resulted in complete L-alanine degradation within 60 h, leaving 185 g of D-alanine in the reaction solution. The immobilized cells were applied for more than 15 cycles of degradation and a maximum utilization rate was achieved at the third cycle. D-alanine was easily extracted from the reaction solution using cation-exchange resin, and the chemical and optical purity of the extracted D-alanine was 99.1 and 99.6%, respectively.


Assuntos
Alanina/metabolismo , Bacillus subtilis/metabolismo , Células Imobilizadas/metabolismo , Alanina/química , Alginatos , Biodegradação Ambiental , Ácido Glucurônico , Ácidos Hexurônicos , Álcool de Polivinil/química
13.
Chemosphere ; 364: 143112, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39153532

RESUMO

In recent years, microplastics (MPs) have been widely found in the environment and pose potential risks to ecosystems, which attracted people's attention. Using bioindicators has been a great approach to understanding the pollution levels, bioavailability, and ecological risks of pollutants. However, only few studies have investigated MPs in mangrove ecosystems, with few bioindicators of MPs. Herein, the distribution of MPs in mangrove sediments and fiddler crabs (Tubuca arcuata) in mangroves was investigated. Results showed that the abundance values of MPs are 1160‒12,120 items/kg and 11-100 items/ind. in mangrove sediments and fiddler crabs, respectively. The dominant shape of MPs detected in mangrove sediments and fiddler crabs was fragments with sizes of 20‒1000 µm, larger MPs of 50-1000 µm were found in abundance. Polypropylene (PP), which is one of the most commonly used plastic materials, was the main polymer type. The distribution of MPs in fiddler crabs closely resembled that in surface mangrove sediments with a strong linear correlation (R2 > 0.8 and p < 0.05) between their abundance. Therefore, the MP contamination level in mangrove sediments can be determined by studying MP pollution in fiddler crabs. Moreover, the results of the target group index (TGI) indicated that fiddler crabs prefer feeding specific MPs in mangrove sediments. Our findings demonstrate the suitability of fiddler crabs as bioindicators for assessing MP pollution in mangrove sediments.


Assuntos
Braquiúros , Monitoramento Ambiental , Sedimentos Geológicos , Microplásticos , Poluentes Químicos da Água , Áreas Alagadas , Animais , Braquiúros/química , Poluentes Químicos da Água/análise , Monitoramento Ambiental/métodos , Sedimentos Geológicos/química , Microplásticos/análise , Ecossistema
14.
Sci Total Environ ; 920: 171124, 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38382609

RESUMO

While microalgal-bacterial membrane bioreactors (microalgal-bacterial MBRs) have risen as an important technique in the realm of sustainable wastewater treatment, the membrane fouling caused by free microalgae is still a significant challenge to cost-effective operation of the microalgal-bacterial MBRs. Addressing this imperative, the current study investigated the influence of magnesium ion (Mg2+) addition on the biological dynamics and membrane fouling characteristics of the laboratory-scale submerged microalgal-bacterial MBRs. The results showed that Mg2+, important in augmenting photosynthetic process, yielded a biomass concentration of 2.92 ± 0.06 g/L and chlorophyll-a/MLSS (mixed liquor suspended solids) of 33.95 ± 1.44 mg/g in the RMg (Mg2+ addition test group). Such augmentation culminated in elevated total nitrogen and phosphorus removal efficiencies, clocking 81.73 % and 80.98 % respectively in RMg. Remarkably, despite the enhanced microalgae activity and concentration in RMg, the TMP growth rate declined by a significant 46.8 % compared to R0. Detailed characterizations attributed reduced membrane fouling of RMg to a synergy of enlarged floc size and reduced EPS contents. This transformation is intrinsically linked to the bridging action of Mg2+ and its role in creating a non-stressed ecological environment for the microalgal-bacterial MBR. In conclusion, the addition of Mg2+ in the microalgal-bacterial MBR appears an efficient approach, improving the efficiency of pollutant treatment and mitigating fouling, which potentially revolutionizes cost-effective applications and propels the broader acceptance of microalgal-bacterial MBRs. It also of great importance to promote the development and application of microalgal-bacterial wastewater treatment technology.


Assuntos
Incrustação Biológica , Microalgas , Águas Residuárias , Incrustação Biológica/prevenção & controle , Membranas Artificiais , Reatores Biológicos/microbiologia , Bactérias , Esgotos
15.
J Am Chem Soc ; 135(41): 15326-9, 2013 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-24088142

RESUMO

An amino-functionalized conjugated metallopolymer PFEN-Hg was developed as a cathode interlayer for inverted polymer solar cells. The resulting devices exhibited significantly improved performance with power conversion efficiencies exceeding 9%. Moreover, good device performance was achievable with the PFEN-Hg over a wider range of film thickness, likely due to the Hg-Hg interactions and improved π-π stacking.


Assuntos
Fontes de Energia Elétrica , Mercúrio/química , Compostos Organometálicos/química , Polímeros/química , Energia Solar , Eletrodos , Estrutura Molecular , Compostos Organometálicos/síntese química
16.
Macromol Rapid Commun ; 34(16): 1301-5, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23873657

RESUMO

Novel supramolecular phosphorescent polymers (SPPs) are synthesized as a new class of solution-processable electroluminescent emitters. The formation of these SPPs takes advantage of the efficient non-bonding assembly between bis(dibenzo-24-crown-8)-functionalized iridium complex monomer and bis(dibenzylammonium)-tethered co-monomer, which is monitored by (1) H NMR spectroscopy and viscosity measurements. These SPPs show good film morphology and an intrinsic glass transition with a Tg of 94-116 °C. Noticeably, they are highly photoluminescent in solid state with quantum efficiency up to ca. 78%. The photophysical and electroluminescent properties are strongly dependent on the molecular structures of the iridium complex monomers.


Assuntos
Complexos de Coordenação/química , Irídio/química , Polímeros/química , Medições Luminescentes , Polímeros/síntese química , Temperatura de Transição , Viscosidade
17.
Huan Jing Ke Xue ; 44(4): 2062-2071, 2023 Apr 08.
Artigo em Zh | MEDLINE | ID: mdl-37040956

RESUMO

The water environment capacity of urban parks is small, and their self-purification ability is poor. They are also more likely to be affected by microplastics (MPs), which cause an imbalance of the water micro-ecosystem. Based on the functional characteristics of parks (comprehensive park, community park, and ecological park), this study investigated the distribution characteristics of MPs in the water of Guilin parks through spot sampling, microscopic observation, and Fourier transform infrared spectroscopy. In addition, the pollution risk index and the pollution load index were used to evaluate the pollution risk of MPs.The results showed that the abundances of MPs in the park surface water and sediments ranged from 104.67-674.44 n·m-3 and 95.57-877.78 n·kg-1, respectively. There were four main shape types of MPs:fragments, fibers, films, and particles. MPs were dominated by fragments and fibers with small sizes (<1 mm). The polymers of MPs were polyethylene and polyethylene terephthalate. There were significant differences in the abundance of MPs in the water of different functional parks, and the abundance of MPs in comprehensive parks was the highest. The abundance of MPs in park water was closely related to the function of the park and the number of people entering the park. The pollution risk of MPs in the surface water of Guilin parks was low, whereas the pollution risk of MPs in sediments was relatively high. The results of this study indicated that tourism was an important source of MPs pollution in the water of Guilin City parks. The pollution risk of MPs in the water of Guilin City parks was mild. However, the pollution risk of MPs accumulated in small freshwater waters of urban parks requires continued attention.


Assuntos
Microplásticos , Poluentes Químicos da Água , Humanos , Plásticos/química , Água , Ecossistema , Poluentes Químicos da Água/análise , Monitoramento Ambiental/métodos , Medição de Risco
18.
Sci Total Environ ; 802: 149922, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34525730

RESUMO

Iron oxide is a natural mineral that generally exists in the form of iron oxide-organic complexes (Fe-OM) in soil. Lignin is a naturally occurring polymer that is considered to be an important part of soil carbon cycling. In this study we prepared a composite material (MGE) with iron oxide and lignin based on the Fe-OM present in the soil. MGE was then applied to remediate Cd and Pb in contaminated soil. The results show that DTPA-Cd and DTPA-Pb levels were reduced by 58.87% and 78.09%, respectively. The bacterial community diversity index decreased in the iron oxide (GE) group, but a slight increase was observed in the MGE group. In terms of species composition in the MGE group, the abundance of Proteobacteria, Gemmatimonadota and Acidobacteriota increased, while the abundance of Bacteroidota, Actinobacteriota and Firmicutes decreased. The outcome in the GE group was the opposite. In the MGE group, HCl-Fe2+, HCl-Fe3+, and pH were significantly higher than in the other groups, indicating that MGE stimulated the growth of iron-reducing bacteria (FeRB) and promoted iron redox reactions. Iron oxide could be reduced to Fe2+ due to the activity of FeRB, and then Fe2+ would be oxidised and hydrolysed, which led to an increase in soil pH. Secondary minerals were formed during this process. With the oxidation of Fe2+ and the formation of secondary minerals, Cd and Pb could be stabilised in the oxides and were not easily released through a co-precipitation mechanism.


Assuntos
Poluentes do Solo , Solo , Bactérias , Cádmio/análise , Compostos Férricos , Chumbo , Lignina , Poluentes do Solo/análise
19.
J Colloid Interface Sci ; 615: 215-226, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35131502

RESUMO

Conductive hydrogel has been considered as a promising material for wearable sensors, constructing a flexible conductive hydrogel sensor with super stretchability, adhesion, and sensing stability is essential, but still challenging. Herein, A super-stretchable, adhesive, and conductive nanocomposite hydrogel was successfully constructed by a facile and one-pot process in conjunction with ball milling and blending. The resulting hydrogel exhibited super-stretchable ability (2795%), excellent tensile stress (128.6 kPa), good fatigue resistance, and self-recovery ability due to multiple cross-linked network structures, including physical hybrid networks (hydrogen bonds and ionic coordination bonds) and flexible polyacrylamide networks. Moreover, the nanocomposite hydrogel showed outstanding conductivity stability, fast response, durability, and repeatability. And it displayed excellent adhesion on various materials. Strain sensors based on hydrogels showed high sensitivity, stability, and action recognition ability. In summary, this work provides a simple strategy for preparing conductive hydrogel sensors with high stretchability, adhesion, and stability, and has potential application prospects in the field of wearable sensors for human body motion detection.


Assuntos
Nanofibras , Dispositivos Eletrônicos Vestíveis , Adesivos/química , Celulose/química , Condutividade Elétrica , Humanos , Hidrogéis/química , Nanogéis
20.
Adv Healthc Mater ; 11(9): e2101944, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-34889072

RESUMO

Engineered immune cells are an exciting therapeutic modality, which survey and attack tumors. Backpacking strategies exploit cell targeting capabilities for delivery of drugs to combat tumors and their immune-suppressive environments. Here, a new platform for arming cell therapeutics through dual receptor and polymeric prodrug engineering is developed. Macrophage and T cell therapeutics are engineered to express a bioorthogonal single chain variable fragment receptor. The receptor binds a fluorescein ligand that directs cell loading with ligand-tagged polymeric prodrugs, termed "drugamers." The fluorescein ligand facilitates stable binding of drugamer to engineered macrophages over 10 days with 80% surface retention. Drugamers also incorporate prodrug monomers of the phosphoinositide-3-kinase inhibitor, PI-103. The extended release of PI-103 from the drugamer sustains antiproliferative activity against a glioblastoma cell line compared to the parent drug. The versatility and modularity of this cell arming system is demonstrated by loading T cells with a second fluorescein-drugamer. This drugamer incorporates a small molecule estrogen analog, CMP8, which stabilizes a degron-tagged transgene to provide temporal regulation of protein activity in engineered T cells. These results demonstrate that this bioorthogonal receptor and drugamer system can be used to arm multiple immune cell classes with both antitumor and transgene-activating small molecule prodrugs.


Assuntos
Neoplasias , Pró-Fármacos , Fluoresceínas , Humanos , Ligantes , Polímeros/química , Pró-Fármacos/química , Pró-Fármacos/farmacologia
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