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Both controllable regulation of the conformational structure of a polypeptide and specific recognition of an amino acid are still arduous challenges. Here, a novel dual-mode (electrochemical and colorimetric) biosensor was built for arginine (Arg) recognition based on a conformation switch, utilizing controllable and synergistic self-assembly of a ferrocene-grafted hexadecapeptide (P16Fc) with gold nanoparticles (AuNPs). Benefiting from the flexibility and unique topological structure of P16Fc formed nanospheres, the assembly and disassembly can undergo a conformation transition induced by Arg through controlling the distance and number of Fc detached from the gold surface, producing on-off electrical signals. Also, they can induce aggregation and dispersion of AuNPs in solution, causing a color change. The mechanism of Arg recognition with polypeptide conformation regulation was well explored by combining microstructure characterizations with molecular mechanics calculations. The electrochemical and colorimetric assays for Arg were successfully established in sensitive and selective manner, not only obtaining a very low detection limit, but also effectively eliminating the interference from other amino acids and overcoming the limitation of AuNP aggregation. Notably, the conformational change-based assay with the peptide regulated by the target will make a powerful tool for the amino acid biosensing and health diagnosis.
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Arginina , Técnicas Eletroquímicas , Compostos Ferrosos , Ouro , Nanopartículas Metálicas , Metalocenos , Peptídeos , Arginina/química , Compostos Ferrosos/química , Metalocenos/química , Ouro/química , Nanopartículas Metálicas/química , Peptídeos/química , Técnicas Biossensoriais/métodos , Colorimetria/métodos , Conformação Proteica , Limite de DetecçãoRESUMO
Chain flexibility or stiffness based polymer conformation plays a crucial role in affecting the dynamics and kinetics of polymers, which is related to the hierarchical architecture of chains. A series of random copolymers of ethylene and 1-alkenes including 1-hexene, 1-octene, and 1-dodecene were synthesized with metallocene catalysts. The crystallization behavior and memory effect in random ethylene-1-alkene copolymers with different side groups were investigated via differential scanning calorimetry (DSC) and wide-angle X-ray scattering (WAXS). Rheological tests were performed for understanding their dynamical behavior. The results show that the melting peak and the viscosity decrease but the orthorhombic crystal dimensions increase with co-unit contents increasing in the copolymers. It was found that the scaling relationship between the zero shear viscosity (η0) and molecular weight (Mn) of the copolymers containing ethylene-1-hexene and ethylene-1-octene is 3.6, which is higher than the classical scaling value of 3.4. The memory of crystals in the melt is enhanced with the increase of 1-alkene contents but is independent of the types of 1-alkenes. The enhanced melt memory effect in the copolymers was proposed due to the effect of the 1-alkene based side groups on the dynamics of polymer chains. The present work would be helpful to understand the chain stiffness based polymer dynamics and processing of polyolefins and copolymers prepared with the metallocene catalyst.
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Although much promising synthetic progress in conjugated polymer-based organic solar cells (OSCs) has resulted in significant improvement in power conversion efficiencies (PCEs) of from over 15 to >19.0% in the last five years, the sophisticated and complex reactions from at least two families' monomers with remarkably different electron push-pull effects could still pose an unavoidable material burden for the commercialization of OSCs in the coming future. Therefore, the method of preparing a homopolymer from a sole monomer would significantly reduce the synthetic steps and costs in order to pave the way for the large-scale production of OSC materials. Therefore, alkylthio-thiophenyl-substituted benzo[1,2-b;4,5-b']dithiophene (BDTTS) as the sole and key structural moiety with dihalogen and distannyl functional groups was designed and synthesized, respectively, in this study, for facile monomer syntheses and polymerizations to achieve three wide-bandgap homopolymer donors of BDTTS-alt-BDTT-Cl (P13), BDTTS-alt-BDTT (P15), and BDTTS (P14), respectively. The structural symmetry dependency on their physical, electrochemical, and optical properties, thin-film morphologies, and photovoltaic (PV) performance was investigated in detail. As a result, OSCs based on the asymmetric polymer P15, paired with BTP-eC9 as the electron acceptor, presented the best PV performance, with a PCE of 11.5%, a fill factor (FF) of 65.87%, and a short-circuit current (JSC) of 22.04 mA·cm-2, respectively. This PCE value is among the highest ones reported for BDT-type homopolymer donor-based OPVs, providing us with knowledge for obtaining promising PV performance from devices made of P15-like materials.
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Being fluorine-free and a high performance material as a small organic acceptor molecule, BTP-eC9 has been well mixed with BDT-based PM6 donor polymers for providing satisfactory photovoltaic properties, especially towards future large scale/large area solar cell production. However, as one of the key electrical outputs from such binary active layer materials, the open circuit voltage (VOC) was limited to ca. 0.84 V, which needs to be further improved for BTP-eC9 to have a bright future. This paper focuses on the molecular design of alkylthio- and alkoxy-phenyl flanked benzo[1,2-b:4,5-b']dithiophene-based conjugated polymers (PBDT-PS-ttTPD or P10 for short and PBDT-PO-ttTPD or P11), which were successfully synthesized and applied as donor materials for pairing with BTP-eC9 in organic photovoltaic (OPV) devices. By fine-tuning the side chains of the benzodithiophene (BDT) moiety, such non-fullerene OPV devices with normal configuration demonstrate an attractively high open circuit voltage (VOC) of 0.89 and 0.87 V in P10/BTP-eC9 and P11/BTP-eC9 based binary single bulk heterojunction OPV devices, while still maintaining an excellent JSC of 22.7 and 20.0 mA cm-2 with a final power conversion efficiency (PCE) of 12.93% and 9.37%, respectively. The alkylthio-phenyl chain substituted BDT polymer exhibits better photovoltaic performance in all aspects than the alternative with alkoxy chains due to the synergistic effect of the alkylthio-phenyl flanked BDT, TPD, and π-bridge (thieno[3,2-b]thiophene).
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BACKGROUND: Streptococcus agalactiae or group B Streptococcus (GBS) is a leading infectious cause of neonatal morbidity and mortality. It is essential to establish a robust method for the rapid and ultra-sensitive detection of GBS in pregnant women with premature rupture of membrane (PROM). METHODS: This study developed a CRISPR-GBS assay that combined the advantages of the recombinase polymerase amplification (RPA) and CRISPR/Cas12a system for GBS detection. The clinical performance of the CRISPR-GBS assay was assessed using vaginal or cervical swabs that were collected from 179 pregnant women with PROM, compared in parallel to culture-based matrix-assisted laser desorption ionization time-of-flight mass spectrometry (culture-MS) method and real-time quantitative polymerase chain reaction (qPCR) assay. RESULTS: The CRISPR-GBS assay can be completed within 35 min and the limit of detection was as low as 5 copies µL-1. Compared with the culture-MS, the CRISPR-GBS assay demonstrated a sensitivity of 96.64% (144/149, 95% confidence interval [CI] 92.39-98.56%) and a specificity of 100% (30/30, 95% CI 88.65-100%). It also had a high concordance rate of 98.88% with the qPCR assay. CONCLUSIONS: The established CRISPR-GBS platform can detect GBS in a rapid, accurate, easy-to-operate, and cost-efficient manner. It offered a promising tool for the intrapartum screening of GBS colonization.
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Complicações Infecciosas na Gravidez , Infecções Estreptocócicas , Recém-Nascido , Gravidez , Feminino , Humanos , Gestantes , Streptococcus agalactiae/genética , Complicações Infecciosas na Gravidez/diagnóstico , Sistemas CRISPR-Cas , Infecções Estreptocócicas/diagnóstico , Vagina , Sensibilidade e EspecificidadeRESUMO
The determination of molecular conformations of oligomeric acceptors (OAs) and their impact on molecular packing are crucial for understanding the photovoltaic performance of their resulting polymer solar cells (PSCs) but have not been well studied yet. Herein, we synthesized two dimeric acceptor materials, DIBP3F-Se and DIBP3F-S, which bridged two segments of Y6-derivatives by selenophene and thiophene, respectively. Theoretical simulation and experimental 1D and 2D NMR spectroscopic studies prove that both dimers exhibit O-shaped conformations other than S- or U-shaped counter-ones. Notably, this O-shaped conformation is likely governed by a distinctive "conformational lock" mechanism, arising from the intensified intramolecular π-π interactions among their two terminal groups within the dimers. PSCs based on DIBP3F-Se deliver a maximum efficiency of 18.09 %, outperforming DIBP3F-S-based cells (16.11 %) and ranking among the highest efficiencies for OA-based PSCs. This work demonstrates a facile method to obtain OA conformations and highlights the potential of dimeric acceptors for high-performance PSCs.
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Region of homozygosity (ROH) is classified as uniparental disomy (UPD) or identity by descent, depending on its origin. To explore the clinical relevance of ROH in prenatal diagnoses, we reviewed 5063 fetal samples subjected to single nucleotide polymorphism array at our center over 5 years. ROH cases meeting our reporting threshold were further analyzed. ROHs were detected in 22 fetuses (0.43%, 22/5063), of which, 77.3% (17/22) showed a ROH on a single chromosome and 22.7% (5/22) showed multiple ROHs on different chromosomes. Among 5063 fetuses undergoing invasive prenatal diagnoses owing to various indications, five cases were identified as UPDs with a rate of ~1/1000. We observed clinically relevant UPDs in two cases related to Prader-Willi syndrome and transient neonatal diabetes mellitus. Of note, one case showed 50% mosaicism for trisomy 2 in amniotic fluid, whereas a complete UPD (2) was observed in umbilical cord blood. Trio whole-exome sequencing was performed for three cases. Clinically relevant variants were identified in two cases, one of which, NM_000302:c.2071_2072insCC (p.R693Qfs*122) in PLOD1 located in the ROH, may be related to Ehlers-Danlos syndrome, kyphoscoliotic type, 1. Overall, 72.7% (16/22) of the ROH carriers showed ultrasound abnormalities, of whom eight (50%, 8/16) had adverse perinatal outcomes. Our study demonstrates that the clinical relevance of ROHs should be examined regarding fetuses with ROHs occurring on imprinted chromosomes or those derived from consanguineous parents in prenatal diagnoses; imprinting disorders and/or autosomal recessive diseases attributed to ROHs should be considered during genetic counseling.
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Polimorfismo de Nucleotídeo Único , Dissomia Uniparental , Gravidez , Recém-Nascido , Feminino , Humanos , Estudos Retrospectivos , Dissomia Uniparental/genética , Mosaicismo , Diagnóstico Pré-Natal , FetoRESUMO
A non-conjugated polymer acceptor PF1-TS4 was firstly synthesized by embedding a thioalkyl segment in the mainchain, which shows excellent photophysical properties on par with a fully conjugated polymer, with a low optical band gap of 1.58â eV and a high absorption coefficient >105 â cm-1 , a high LUMO level of -3.89â eV, and suitable crystallinity. Matched with the polymer donor PM6, the PF1-TS4-based all-PSC achieved a power conversion efficiency (PCE) of 8.63 %, which is ≈45 % higher than that of a device based on the small molecule acceptor counterpart IDIC16. Moreover, the PF1-TS4-based all-PSC has good thermal stability with ≈70 % of its initial PCE retained after being stored at 85 °C for 180â h, while the IDIC16-based device only retained ≈50 % of its initial PCE when stored at 85 °C for only 18â h. Our work provides a new strategy to develop efficient polymer acceptor materials by linkage of conjugated units with non-conjugated thioalkyl segments.
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A label-free fluorescence turn-on strategy for alkaline phosphatase (ALP) detection was established based on its enzymatic catalyzed hydrolysis of polyphosphoric acid (PPA, an anionic polymer) that had been utilized for aggregation with our homemade positively charged perylene derivative (Probe-1) via noncovalent interactions. The disaggregation caused turn-on fluorescence signal which was recovered by the released Proble-1 molecules whose original strong fluorescence in an aqueous buffer solution had been quenched due to their previous aggregation induced by PPA. Such method presents its great advantages of free labeling, convenience and simplicity, cost effectiveness, high selectivity, and high sensitivity, with a detection limit of 0.5 mU/mL of ALP. Graphical Abstract A label-free fluorescence turn-on strategy for alkaline phosphatase based on its enzymatic catalyzed hydrolysis of polyphosphoric acid that had been utilized for aggregation with our homemade positively charged perylene derivative via noncovalent interactions.
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Fosfatase Alcalina/análise , Perileno/química , Ácidos Fosfóricos/química , Polímeros/química , Espectrometria de FluorescênciaRESUMO
A sensitive and convenient flow-injection chemiluminescence (FI-CL) turn-on assay for alkaline phosphatase (ALP) activity without any label and synthesis is developed. Cu2+ can catalyze the luminol-H2 O2 CL reaction. Pyrophosphate (PPi) can chelate Cu2+ and therefore the Cu2+ -mediated luminol-H2 O2 CL reaction is inhibited. The addition of ALP can catalyze the hydrolysis of PPi into phosphate ions, Cu2+ is released and the chemiluminescence recovers. A detection limit of 1 mU/mL ALP is obtained.
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Fosfatase Alcalina/metabolismo , Difosfatos/metabolismo , Medições Luminescentes/métodos , Fosfatase Alcalina/análise , Fosfatase Alcalina/sangue , Cobre/química , Enzimas/metabolismo , Humanos , Peróxido de Hidrogênio/química , Limite de Detecção , Medições Luminescentes/instrumentação , Luminol/química , Especificidade por SubstratoRESUMO
BACKGROUND: Sialyltransferase I (ST6Gal-I) is an enzyme involved in tumor metastasis that processes sialic acid precursors into their mature form, enabling them to regulate gene expression. However, the effect of ST6Gal-I on the biological behavior of cancer cells remain unclear. This study was the first to demonstrate the influence of ST6Gal-I on cisplatin sensitivity in cervical cancer cells. METHODS: Knockdown of ST6Gal-I was performed by shRNA and HeLa cells combination with cisplatin were tested. RESULTS: We showed that down-regulation of ST6Gal-I promoted cell apoptosis and inhibited proliferation and invasion in cervical cancer cells. Knockdown of ST6Gal-I by RNA interference increased the sensitivity of HeLa cells to cisplatin in vitro, and reduced tumor volume and suppressed subcutaneous tumor growth in response to cisplatin treatment in a xenograft mouse model in vivo. CONCLUSIONS: The results provide new information that ST6Gal-I plays an important role in several biological or pathological processes including drug resistance in cervical cancer and may be a potential therapeutic target to improve the response to chemotherapy in cervical cancer patients.
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Antígenos CD/genética , Cisplatino/administração & dosagem , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , RNA Interferente Pequeno/farmacologia , Sialiltransferases/genética , Neoplasias do Colo do Útero/tratamento farmacológico , Animais , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Cisplatino/farmacologia , Sinergismo Farmacológico , Feminino , Regulação Neoplásica da Expressão Gênica , Técnicas de Silenciamento de Genes , Células HeLa , Humanos , Camundongos , Neoplasias do Colo do Útero/genética , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
BACKGROUND: Centrally necrotizing carcinoma of the breast (CNC) represents a newly-identified subset of breast cancer. The clinical and pathological characteristics of this breast cancer subtype are not yet completely understood. METHODS: We assessed the clinicopathological characteristics of 73 cases of CNC and 30 control cases of high-grade infiltrating ductal carcinoma (IDC) with focal necrosis based on light microscopy and immunohistochemical staining for estrogen receptor, progesterone receptor, Cerb-B2/HER2, Ki-67, epidermal growth factor receptor, cytokeratin 5/6, smooth muscle actin, S-100 protein, p63 and CD10. RESULTS: All the tumors showed extensive central necrotic or acellular zones with different degrees of fibrotic or hyaline material surrounded by ring-like or ribbon-like residual tumour tissue which were usually high-grade IDCs. The central necrotic zone accounted for at least 30% of the cross-sectional area of the tumor. Thirty-six cases (49.3%) showed a component of ductal carcinoma in situ. The tumorous stroma around the central necrotic zone was accompanied by myxoid matrix formation in 28 cases (40%). Lymphocytic infiltration was present in 53 cases (72.6%). Granulomatous reactions were detected at the periphery of the tumors in 49 cases (67.1%). Immunohistochemistry showed greater expression of basal-like markers (72.2%, 52 cases) than myoepithelial markers (60.6%, 43 cases), both of which were significantly higher than in controls (26.7%, 8 cases) (P < 0.001). According to molecular typing, most CNCs were basal-like subtype (37 cases, 50.7%). Follow-up data were available for 28 patients. Disease progression occurred in 11 patients. The combined rate of recurrence, distant metastasis or death was significantly higher in CNC patients compared with controls (P < 0.05). CONCLUSIONS: CNC was associated with distinctive clinicopathologic features mostly characterized as basal-like type. Its high proliferative activity, highly-aggressive biological behavior, and high rates of recurrence and metastasis, suggest that CNC should be classified as a new type of breast carcinoma.
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Biomarcadores Tumorais/metabolismo , Neoplasias da Mama/patologia , Mama/patologia , Carcinoma Ductal de Mama/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Mama/metabolismo , Neoplasias da Mama/metabolismo , Carcinoma Ductal de Mama/metabolismo , Diagnóstico Diferencial , Feminino , Humanos , Pessoa de Meia-Idade , Necrose , PrognósticoRESUMO
A new two-dimensional (2D) conjugated small molecule, namely DCA3TBDTP, with an alkoxyphenyl substituted benzo[1,2-b:4,5-b']dithiophene (BDT) unit as the central core, octyl cyanoacetate as the end-capped groups and terthiophene as the π-linked bridge, was designed and synthesized for solution-processed organic solar cells (OSCs) as an electron donor material, in which an alkoxyphenyl group was introduced as a weak electron-donating side chain of the BDT moiety. The DCA3TBDTP molecule exhibited good solubility, a deep highest occupied molecular orbital (HOMO) level (-5.25 eV), an appropriate optical band-gap (1.82 eV) and a high decomposition temperature (362 °C). By applying the simple solution spin-coating fabrication process, the bulk heterojunction (BHJ) OSCs based on DCA3TBDTP and [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM) exhibited a good power conversion efficiency (PCE) of 4.51% with a high open-circuit voltage (Voc) of 0.90 V when thermal annealing at only 70 °C.
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Fontes de Energia Elétrica , Nitrilas/química , Energia Solar , Tiofenos/química , Estrutura Molecular , Nitrilas/síntese química , Tiofenos/síntese químicaRESUMO
In order to develop a highly efficient H2S gas sensor at low working temperature, in this work, a kind of novel Ce-doped ZnCo2O4 hollow microspheres (Ce/ZnCo2O4 HMSs) were successfully synthesized using a template-free one-pot method, showing a sensitive response toward H2S. The microstructure and morphology of the material were characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The gas-sensing performance of the composite was investigated, showing that the ZnCo2O4 doped with 6 mol% Ce had the highest response to 20 ppm H2S at a low operating temperature of 160 °C with a response value of 67.42, which was about 2 times higher than that of original ZnCo2O4. The prepared Ce/ZnCo2O4 HMS sensor in response to H2S exhibited a linear range of 0.1-200 ppm with a low detection limit of 0.1 ppm under the conditions of ambient humidity of 45% and ambient temperature of 20 °C. Meanwhile, it also possessed good selectivity, repeatability and reproducibility. The response value of the sensor decreased by 5.32% after 7 months of continuous monitoring of H2S in an atmospheric environment of a pig farm, indicating that the sensor had a long-term stability and continuous service life with important application prospects.
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The rampant use of antibiotics in animal husbandry, farming and clinical disease treatment has led to a significant issue with pathogen resistance worldwide over the past decades. The classical mechanisms of resistance typically investigate antimicrobial resistance resulting from natural resistance, mutation, gene transfer and other processes. However, the emergence and development of bacterial resistance cannot be fully explained from a genetic and biochemical standpoint. Evolution necessitates phenotypic variation, selection, and inheritance. There are indications that epigenetic modifications also play a role in antimicrobial resistance. This review will specifically focus on the effects of DNA modification, histone modification, rRNA methylation and the regulation of non-coding RNAs expression on antimicrobial resistance. In particular, we highlight critical work that how DNA methyltransferases and non-coding RNAs act as transcriptional regulators that allow bacteria to rapidly adapt to environmental changes and control their gene expressions to resist antibiotic stress. Additionally, it will delve into how Nucleolar-associated proteins in bacteria perform histone functions akin to eukaryotes. Epigenetics, a non-classical regulatory mechanism of bacterial resistance, may offer new avenues for antibiotic target selection and the development of novel antibiotics.
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Antibacterianos , Farmacorresistência Bacteriana , Animais , Antibacterianos/farmacologia , Farmacorresistência Bacteriana/genética , Epigênese Genética , Criação de Animais Domésticos , Proteínas Nucleares , DNARESUMO
Objective: This study investigated the molecular epidemiology of Group B Streptococcus (GBS) in pregnant women with premature rupture of membranes (PROM) in Fuzhou region of China as a source of clinical reference. Methods: GBS isolates were obtained from pregnant women with PROM. All isolates were genotyped, serotyped, and tested for drug-resistance and virulence genes using PCR and DNA sequencing. Antibiotic susceptibility testing was performed using the Vitek® 2 automated system. Results: Among the 140 GBS isolates, seventeen sequence types (STs) were identified, of which ST19 (20.0%) was the most prevalent, followed by ST862, ST10, and ST12. Three clonal complexes (CC19, CC10 and CC1) were identified. The predominant serotype was III (45.7%), followed by V (23.6%), Ib (18.6%), Ia (7.1%), and II (3.6%). The prevalence of multidrug resistance was 72.8% (102/140). All isolates were susceptible to penicillin G, ampicillin, quinupristin, linezolid, vancomycin, and tigecycline. The majority of isolates were resistant to erythromycin (70.0%), clindamycin (72.1%), and tetracycline (81.4%), and 28.6% of isolates were resistant to levofloxacin and moxifloxacin. Of the 98 erythromycin-resistant strains, mreA, ermB, mefA, mefE, ermA, and ermTR were detected in 100%, 70.4%, 49.0%, 22.4%, 13.3%, and 9.2%, respectively. No linB was detected among 101 clindamycin-resistant strains. Of the 114 tetracycline-resistant strains, tetM, tetK, tetL and tetO were detected in 52.6%, 61.4%, 7.9%, and 23.7%, respectively. Regarding virulence genes, all strains carried rib and hylB, followed by scpB (98.6%), and bca (80.7%), whereas only one strain carried bac. Conclusion: ST19/III and ST862/III were the most prevalent GBS subtypes. Penicillin G remains a first-line antibiotic for intrapartum antibiotic prophylaxis and treatment of GBS infections. The prevalence of resistance to clindamycin, erythromycin, and tetracycline is high among GBS isolates in the Fuzhou region. ST862 and ST651 are emerging animal origin STs in human infections, and may become potential zoonotic threats.
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In this work, a new type of H2S sensor was fabricated by means of drop-coating of an Au/SnO-SnO2 nanosheet material, which was prepared by a one-pot hydrothermal reaction, onto a gold electrode in an alumina ceramic tube with the formation of a thin nanocomposite film. The microstructure and morphology of the nanosheet composites were characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). A gas-sensitivity study presented good H2S-sensing performance of such Au/SnO-SnO2 nanosheet composites. At an optimal operating temperature of 240 °C and ambient temperature of 25 °C, the resulting sensor showed a good linear response to H2S in a range of 1.0 to 100 ppm with a low detection limit of 0.7 ppm, and a very fast response-recovery time of 22 s for response and 63 s for recovery, respectively. The sensor was also unaffected by ambient humidity and had good reproducibility and selectivity. When being applied to the monitoring of H2S in an atmospheric environment in a pig farm, the response signal to H2S was only attenuated by 4.69% within 90 days, proving that the sensor had a long and stable service lifetime for continuous running and showing its important practical application prospects.
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Superior flexibility and toughness can be achieved in bioactive hydrogels by the use of a double polymer network with complementary properties. Inspired by this design principle, we here combine polyacrylic acid (PAA) and sodium alginate (SA) to obtain a dual-reinforced double interpenetrating network (d-DIPN) hydrogel. The dual reinforcement involves ionic cross-linking and introduction of SiO2 nanoparticles, which leads to extraordinary improvements in strength and toughness. Compared with the standard PAA hydrogel that offers an elongation of 240% and a breakage stress of 0.03 MPa, the prepared SA(Ca2+)-PAA-SiO2 hydrogel shows an elongation above 1000% and a breakage stress of 1.62 MPa. Moreover, the combination of strong covalent cross-links and weak reversible interactions provides the d-DIPN hydrogel with swelling resistance and self-healing behavior, adhesive abilities, and shape memory performance. Furthermore, we show that the biocompatibility and bone cell proliferation ability of the hydrogels can be improved through a mineralization process despite an observed reduction in breakage strain and stress. Taken as a whole, our work paves the way for the design of strong and tough hydrogels, with potential applications within biomedicine and particularly tissue engineering.
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Polímeros , Dióxido de Silício , Polímeros/farmacologia , Hidrogéis/farmacologia , Engenharia Tecidual , Alginatos/farmacologiaRESUMO
Industrial and municipal wastes remain significant sources of air, soil, and water pollution, thus causing adverse climate and health impacts. EU faces challenges in developing green recycling processes and reducing GHG emissions. Innovation in green catalysis is a key driver toward the fulfilment of these goals. This study demonstrated a single-step "Green Recycling" route by which different wastes e.g., industrial and bioorganic wastes are treated to produce biochar/Fe(0) (BC-Fe(0)) material. Typically, three different biomass namely organic fraction of municipal solid waste (biopulp), wheat straw (WS), and microalgae (MA) were used as green reducing agents for reducing bauxite residue (BR). Among all biomass, the high reduction potential of amino acids present in biopulp facilitated the synthesis of BC-Fe(0). BC-Fe(0) material acted as an effective catalyst for HTL of biopulp as the results showed the highest bio-crude yield (44 wt%) at 300 °C for 30 min with 10 wt% BC-Fe(0) loading (containing 2.5 wt% Fe). Furthermore, BC-Fe(0) also assisted in-situ hydrogenation and deoxygenation of chemical compounds present in the bio-liquid product, therefore bio-crude exhibited a higher H/C ratio (1.73) and lower oxygen contents (9.78 wt%) in comparison to bio-crude obtained without catalyst. However, Raw BR and reduced BR (RED) as catalysts showed no significant effect on the yield and oxygen content of bio-crude, which confirms the high catalytic activity of Fe(0) containing BC-Fe(0). Therefore, this study demonstrates the greener path for the one-step valorization of industrial and organic wastes, as an alternative to existing chemical and high temperature-based waste recycling and catalyst synthesis technologies.
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Through electrochemical polymerization using L-glutamic acid (L-Glu) as a template and 4,6-diaminoresorcinol as a functional monomer, an enzyme-free molecularly imprinted polymer (MIP) based L-Glu sensor with multi-walled carbon nanotubes (MWCNTs) decorated on a glassy carbon electrode (GCE), namely G-MIP/MWCNTs/GCE, was developed in this work. The reaction conditions were optimized as follows: electrochemical polymerization of 23 cycles, pH of 3.0, molar ratio of template/monomer of 1 : 4, volume ratio of elution reagents of acetonitrile/formic acid of 1 : 1, and elution time of 2 min. The prepared materials and molecularly imprinted polymer were characterized by using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) as well as electrochemical methods. The electrochemical properties of different electrodes were investigated via differential pulse voltammetry (DPV), showing that the electrode of G-MIP/MWCNTs/GCE exhibited excellent catalytic oxidation activity towards L-Glu. A good linear relationship between peak-currents and L-Glu concentrations in a range from 1.00 × 10-8 to 1.00 × 10-5 mol L-1 was observed, with a detection limit of 5.13 × 10-9 mol L-1 (S/N = 3). The imprinted sensor possesses excellent selectivity, high sensitivity, and good stability, which have been successfully applied for the detection of L-Glu in pig serum samples with a recovery rate of 97.4-105.5%, being comparable to commercial high-performance liquid chromatography, demonstrating a simple, rapid, and accurate way for the determination of L-Glu in the fields of animal nutrition and biomedical engineering.