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A polymer acceptor, named PX-1, is designed and synthesized using a polymerization strategy with grafted small molecule acceptors. This design approach allows for the freedom of end groups while maintaining efficient terminal packing, enhancing π-π interactions, and facilitating charge transport. All-polymer organic solar cells based on PM6: PX-1 demonstrate a promising efficiency of 13.55%. The result presents an alternative pathway for the design of high-efficiency polymer acceptors through the careful regulation of small molecule acceptor monomers and linker units.
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Vendajes , Polímeros , PolimerizacionRESUMEN
Microplastics (MPs) in farming soils can have a substantial impact on soil ecology and agricultural productivity, as well as affecting human health and the food chain cycle. As a result, it is vital to study MPs detection technologies that are rapid, efficient, and accurate in agriculture soils. This study investigated the classification and detection of MPs using hyperspectral imaging (HSI) technology and a machine learning methodology. To begin, the hyperspectral data was preprocessed using SG convolution smoothing and Z-score normalization. Second, the feature variables were extracted from the preprocessed spectral data using bootstrapping soft shrinkage, model adaptive space shrinkage, principal component analysis, isometric mapping (Isomap), genetic algorithm, successive projections algorithm (SPA), and uninformative variable elimination. Finally, three support vector machine (SVM), back propagation neural network (BPNN), and one-dimensional convolutional neural network (1D-CNN) models were developed to classify and detect three microplastic polymers: polyethylene, polypropylene, and polyvinyl chloride, as well as their combinations. According to the experimental results, the best approaches based on three models were Isomap-SVM, Isomap-BPNN, and SPA-1D-CNN. Among them, the accuracy, precision, recall and F1_score of Isomap-SVM were 0.9385, 0.9433, 0.9385 and 0.9388, respectively. The accuracy, precision, recall and F1_score of Isomap-BPNN were 0.9414, 0.9427, 0.9414 and 0.9414, respectively, while the accuracy, precision, recall and F1_score of SPA-1D-CNN were 0.9500, 0.9515, 0.9500 and 0.9500, respectively. When their classification accuracy was compared, SPA-1D-CNN had the best classification performance, with a classification accuracy of 0.9500. The findings of this study shown that the SPA-1D-CNN based on HSI technology can efficiently and accurately identify MPs in farmland soils, providing theoretical backing as well as technical means for real-time detection of MPs in farmland soils.
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Microplásticos , Plásticos , Humanos , Imágenes Hiperespectrales , Suelo , Granjas , TecnologíaRESUMEN
Co-loading doxorubicin (DOX) and Schizandrin A (SchA) long-circulating liposome (SchA-DOX-Lip) have been confirmed to have good antitumor activity in vitro. However, in vivo pharmacodynamics, targeting, safety, and mechanism of action of SchA-DOX-Lip still need to be further verified. We investigated the tumor inhibition effect, targeting, safety evaluation, and regulation of tumor apoptosis-related proteins of the SchA-DOX-Lip. MTT assay was used to investigate the inhibitory effect of SchA-DOX-Lip on CBRH7919 cells. The drug uptake of CBRH7919 cells was observed by inverted fluorescence microscope. The tumor-bearing nude mice models of CBRH7919 were established, and the anti-tumor effect of SchA-DOX-Lip in vivo was evaluated by tumor biological observation, H&E staining, and TUNEL staining. The distribution and targeting of SchA-DOX-Lip in nude mice models were investigated by small animal imaging and tissue distribution experiment of CBRH7919. The biosafety of SchA-DOX-Lip was evaluated by blood routine parameters, biochemical indexes, and H&E staining. The expression of tumor-associated apoptotic proteins (Bcl-2, Bax, and Caspase-3) was detected by immunohistochemistry anvd western blotting. The results showed that SchA-DOX-Lip had cytotoxicity to CBRH7919 cells which effectively inhibited the proliferation of CBRH7919 cells, improved the uptake of drugs by CBRH7919 cells and the targeting effect of drugs on tumor site. H&E staining and biochemical detection results showed that SchA-DOX-Lip had high biosafety and did not cause serious damage to normal tissues. Western-blotting and TUNEL staining results showed that SchA-DOX-Lip could improve the regulatory effect of drugs on tumor apoptosis proteins. It was demonstrated that SchA-DOX-Lip had high safety and strong tumor inhibition effects, providing a new method for the clinical treatment of hepatocellular carcinoma (HCC).
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Carcinoma Hepatocelular , Neoplasias Hepáticas , Animales , Ratones , Liposomas/farmacología , Ratones Desnudos , Neoplasias Hepáticas/tratamiento farmacológico , Carcinoma Hepatocelular/tratamiento farmacológico , Doxorrubicina/farmacología , Apoptosis , Línea Celular TumoralRESUMEN
AA9 lytic polysaccharide monooxygenases (LPMOs) are copper-dependent metalloenzymes that play a major role in cellulose degradation and plant infection. Understanding the AA9 LPMO mechanism would facilitate the improvement of plant pathogen control and the industrial application of LPMOs. Herein, via point mutation, we investigated the role of glycine 2 residue in cellulose degradation by Thermoascus aurantiacus AA9 LPMOs (TaAA9). A computational simulation showed that increasing the steric properties of this residue by replacing glycine with threonine or tyrosine altered the H-bonding network of the copper center and copper coordination geometry, decreased the surface charge of the catalytic center, weakened the TaAA9-substrate interaction, and enhanced TaAA9-product binding. Compared with wild-type TaAA9, G2T-TaAA9 and G2Y-TaAA9 variants showed attenuated copper affinity, reduced oxidative product diversity and decreased substrate Avicel binding, as determined using ITC, MALDI-TOF/TOF MS and cellulose binding analyses, respectively. Consistently, the enzymatic activity and synergy with cellulase of the G2T-TaAA9 and G2Y-TaAA9 variants were lower than those of TaAA9. Hence, the investigated residue crucially affects the catalytic activity of AA9 LPMOs, and we propose that the electropositivity of copper may correlate with AA9 LPMO activity. Thus, the relationship among the amino acid at position 2, surface charge and catalytic activity may facilitate an understanding of the proteins in AA9 LPMOs.
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Cobre , Oxigenasas de Función Mixta , Oxigenasas de Función Mixta/metabolismo , Cobre/metabolismo , Polisacáridos/metabolismo , Celulosa/metabolismo , Oxidación-ReducciónRESUMEN
PURPOSE: The aim of this study was to investigate the effect of lidocaine for patient controlled intravenous analgesia (PCIA) in patients who underwent open hepatectomy. DESIGN: A retrospective analysis. METHODS: A total of 281 patients who underwent open hepatectomy from July 2018 to December 2018 were included. All patients were assigned into two groups: the lidocaine group (PCIA consisted of lidocaine, sufentanil, tramadol and granisetron) and the control group (PCIA consisted of sufentanil, tramadol and granisetron). The postoperative visual analogue scale (VAS) and complications (including respiratory depression, hypotension, nausea and vomiting, pruritus, numbness of the corners of the mouth, dizziness) between the groups were compared. FINDINGS: There were no significant differences between the characteristics, duration of surgery and anesthesia, and recovery of postoperative activity between the two groups. In the first 3 days after the operation, the postoperative VAS score of the lidocaine group was lower than that of the control group at resting state, while after activity, the postoperative VAS contrast results were completely opposite. In particularly, the resting state at 48 hours (h) (1.05 ± 1.25 vs 1.57 ± 1.54) after surgery and the activity state at 72 h (3.02 ± 1.51 vs 2.2 ± 1.66) after surgery (P < 0.05). The incidence of mouth numbness and dizziness were significantly increased in the lidocaine group (P < 0.05). CONCLUSION: The addition of lidocaine in PCIA was not beneficial to improve the pain during activities and increased the incidence of perioral numbness and dizziness.
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Lidocaína , Tramadol , Humanos , Sufentanilo/efectos adversos , Granisetrón , Estudios Retrospectivos , Mareo/inducido químicamente , Hepatectomía/efectos adversos , Hipoestesia/inducido químicamente , Dolor Postoperatorio/tratamiento farmacológico , Analgesia Controlada por el Paciente/métodos , AnalgésicosRESUMEN
Since the 1960s, many indoor and outdoor smog chambers have been developed worldwide. However, most of them are made of Teflon films, which have relatively high background contaminations due to the wall effect. We developed the world's first medium-size quartz chamber (10 m3), which is jointed with 32 pieces of 5 mm thick polished quartz glasses and a stainless-steel frame. Characterizations show that this chamber exhibits excellent performance in terms of relative humidity (RH) (2-80%) and temperature (15-30 ± 1 °C) control, mixing efficiency of the reactants (6-8 min), light transmittance (>90% above 290 nm), and wall loss of pollutants. The wall loss rates of the gas-phase pollutants are on the order of 10-4 min-1 at 298 K under dry conditions. It is 0.08 h-1 for 100-500 nm particles, significantly lower than those of Teflon chambers. The photolysis rate of NO2 (JNO2) is automatically adjustable to simulate the diurnal variation of solar irradiation from 0 to 0.40 min-1. The inner surface of the chamber can be repeatedly washed with deionized water, resulting in low background contaminations. Both experiments (toluene-NOx and α-pinene-ozone systems) and box model demonstrate that this new quartz chamber can provide high-quality data for investigating SOA and O3 formation in the atmosphere.
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Contaminantes Atmosféricos , Ozono , Aerosoles/análisis , Contaminantes Atmosféricos/análisis , Ozono/análisis , Politetrafluoroetileno , Cuarzo , Esmog/análisisRESUMEN
The aim of this study was to identify the aggregation sites and transmission characteristics of Gasterophilus pecorum, the dominant pathogen of endangered equines in desert steppe. Therefore, we tested with a four-arm olfactometer the olfactory response of the G. pecorum adults to the odors that have a great impact on their life cycle, and also investigated the occurrence sites of the adults in the area where the Przewalski's horse (Equus przewalskii) roam frequently during the peak period of G. pecorum infection. The results of four-directional olfactory test showed that the fresh horse feces had a stronger attraction rate on both male (50.4%) and female flies (38.2%). Stipa caucasica, the only oviposition plant where G. pecorum lay eggs, had a better attraction effect on females than that on males. And the attraction rates of S. caucasica to G. pecorum females in the early growth stage (Stipa I) and mid-growth stage (Stipa II) were 32.8% and 36.8%, respectively. In addition, the two-directional olfactory test showed that the attraction rate of males to fresh horse feces (68.90%) was higher than that to Stipa II (31.10%), and females also showed similar olfactory responses. Moreover, in our field investigation, 68.29% of G. pecorum adults were collected from around the horse feces. The results of laboratory test and field investigation implied that the location mechanism of G. pecorum aggregation for mating is related to the orientation of horse feces. The horse feces and the vicinity are the key contamination areas of G. pecorum, and it is also the areas where horses are seriously infected with G. pecorum. Those fresh feces, which gather abundant information about the host, naturally had the greatest chance of contacting with the host; G. pecorum adults create the opportunity to enter directly into the host's mouth and infect the host by laying eggs on S. caucasica, which is the most favorite plant of the host in this area. These characteristics are one of the main reasons why G. pecorum has become the dominant species under the condition of sparse vegetation in desert steppe.
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Dípteros/fisiología , Heces/química , Enfermedades de los Caballos/parasitología , Enfermedades de los Caballos/transmisión , Parasitosis Intestinales/transmisión , Animales , Clima Desértico , Especies en Peligro de Extinción , Heces/parasitología , Femenino , Caballos , Parasitosis Intestinales/parasitología , Masculino , Parásitos/crecimiento & desarrollo , Parásitos/aislamiento & purificación , Desarrollo de la Planta , PlantasRESUMEN
Cross-family transcription factor (TF) interactions play critical roles in the regulation of plant developmental and metabolic pathways. WRINKLED1 (WRI1) is a key TF governing oil biosynthesis in plants. However, little is known about WRI1-interacting factors and their roles in oil biosynthesis. We screened a TF library using Arabidopsis (Arabidopsis thaliana) WRI1 (AtWRI1) as bait in yeast two-hybrid assays and identified three TEOSINTE BRANCHED1/CYCLOIDEA/PROLIFERATING CELL FACTOR (TCP) family TFs, namely TCP4, TCP10, and TCP24, as AtWRI1-interacting partners. The physical interaction between AtWRI1 and TCPs was further validated using bimolecular fluorescence complementation assays. TCPs play important roles in various plant developmental processes; however, their involvement in fatty acid biosynthesis was not previously known. Coexpression of TCP4, but not TCP10 or TCP24, with AtWRI1 reduced AtWRI1-mediated oil biosynthesis in Nicotiana benthamiana leaves. Transcriptomic analysis in transgenic Arabidopsis plants with enhanced TCP4 activity engineered by expressing rTCP4 (i.e. miR319-resistant TCP4) revealed that AtWRI1 target genes were significantly repressed. TCP4 expression is strongly correlated with AtWRI1 during embryo development. A tcp4 loss-of-function mutant, the jaw-D mutant with a strong reduction of TCP4 expression, and a tcp2 tcp4 tcp10 triple mutant accumulated more seed oil than wild-type Arabidopsis. In addition, TCP4 repressed the AtWRI1-mediated transactivation of the promoters of fatty acid biosynthetic genes. Collectively, our findings suggest that TCP4 represses fatty acid biosynthetic gene expression through interaction with AtWRI1, leading to a reduction of AtWRI1-mediated seed oil accumulation.
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Proteínas de Arabidopsis/metabolismo , Ácidos Grasos/biosíntesis , Semillas/metabolismo , Factores de Transcripción/metabolismo , Arabidopsis , Semillas/crecimiento & desarrollo , NicotianaRESUMEN
8-Shaped copolymers with two macrocycles connected together represent an interesting cyclic topology-derived polymer species due to the simultaneous incorporation of two cyclic moieties and the reported unique physical and chemical properties. To provide a proof-of-concept for a broad readership on biomedical polymers, a well-defined hetero-8-shaped amphiphilic copolymer, cyclic-poly(oligo(ethylene glycol)monomethyl ether methacrylate)-b-cyclic PCL (cPOEGMA-b-cPCL) is synthesized by an elegant integration of intrachain click cyclization and interchain click coupling. The potential of the self-assembled micelles of cPOEGMA-b-cPCL for controlled drug release is evaluated by in vitro drug loading and drug release, cellular uptake, cytotoxicity, and degradation studies. Most importantly, the micelles based on cPOEGMA-b-cPCL show much slower degradation profiles than the previously reported linear counterpart, POEGMA-b-PCL and tadpole-shaped analog, PEG-b-cPCL because of the presence of cyclic hydrophilic POEGMA segment. Therefore, this study not only develops a robust strategy for a universal precise synthesis of well-defined hetero-8-shaped copolymers based on diverse vinyl and ring-structured monomers, but also reveals the first modulation of polymer degradation property by topological control of the nondegradable moiety in the polymer construct through advanced macromolecular engineering.
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Micelas , Polímeros , Portadores de Fármacos , Liberación de Fármacos , Sustancias Macromoleculares , Metacrilatos , PolietilenglicolesRESUMEN
OBJECTIVE: To summarize the clinical features of primary nephrotic syndrome (PNS) complicated by plastic bronchitis (PB) in children to provide guidance for treatment. METHODS: We conducted a retrospective review of the clinical data of 25 children hospitalized with NS complicated by PB in our Hospital between 10/2016 and 03/2019, and summarized the clinical manifestations, imaging and fiberoptic bronchoscopy (FOB) examinations, treatment course and outcome of them. RESULTS: 1). The 25 children, with a nephrotic syndrome (NS) course of one to 36 months, were all diagnosed with PB after FOB, among which 8 cases (32%) had respiratory failure and required ventilatory support. All of them started with respiratory symptoms such as fever and cough, and then suffered from dyspnea and progressive aggravation after 1-3 day(s) of onset, with rapid occurrence of bidirectional dyspnea and even respiratory failure in severe cases. 2). Laboratory test for pathogens: influenza A virus H1N1 (11 cases), influenza B virus (9 cases), adenovirus (3 cases) and mycoplasma pneumoniae (2 cases). There was no statistically significant difference (P>0.05) between children with common NS complicated by influenza virus (IV) infection (not accompanied by dyspnea) and those with kidney disease who developed PB in the white blood cell count, lymphocyte count, the inflammatory biomarkers C-reactive protein (CRP), procalcitonin (PCT) and humoral immunity (IgG level), yet the total IgG level was found significantly higher and the blood albumin level lower in the latter (P<0.05). 3). The 25 children were all examined with the FOB and treated with lavage, 15 of which had typical bronchial tree-like casts and 10 broken and stringy casts. Based on histopathological classification, all children were of Type I. 4). Twenty children (80%) with influenza were administered the antiviral drug Oseltamivir, 20 (80%) were treated with antibiotics, oral hormones were replaced with the same dosage of intravenous Methylprednisolone for 5 cases (20%), and 20 (80%) were intravenously administered gamma globulins (400-500 mg/kg x 3 days). These children showed a remarkable improvement after treatment and there were no deaths. CONCLUSION: NS children are at high risk of influenza virus infection. Children with a severe case of NS are more susceptible to PB. If symptoms like shortness of breath, wheezing and progressive bidirectional dyspnea occur, FOB examination and lavage treatment should be performed as early as possible. Hyper-IgE-emia and hypoproteinemia may be the high risk factors for PNS complicated by PB in children. ZIEL: Ziel der Studie war es, durch Zusammenfassung der klinischen Merkmale des primären nephrotischen Syndroms (PNS) mit komplizierender plastischer Bronchitis (PB) im Kindesalter eine Orientierungshilfe für die Therapie der Erkrankung zu geben. METHODIK: Wir führten eine retrospektive Prüfung der klinischen Daten von 25 Kindern durch, die zwischen Oktober 2016 und März 2019 in unser Krankhaus aufgenommen wurden, und erstellten eine Zusammenfassung der klinischen Symptome, Untersuchungen mit bildgebenden Verfahren und fiberoptischer Bronchoskopie (FOB), des Therapieverlaufs und des Outcomes der Patienten. ERGEBNISSE: 1). Bei den 25 Kindern bestand ein nephrotisches Syndrom (NS) über einen Zeitraum von einem bis 36 Monaten. Bei allen Patienten wurde die Diagnose PB nach FOB gestellt, wobei in 8 Fällen (32%) eine beatmungspflichtige respiratorische Insuffizienz vorlag. Alle Patienten zeigten anfänglich Symptome einer Atemwegserkrankung wie Fieber und Husten, gefolgt von Atemnot und progredienter Verschlechterung 1 bis 3 Tage nach Erkrankungsbeginn. Dabei kam es rasch zum Auftreten bidirektionaler Atemnot, in schweren Fällen bis hin zur respiratorischen Insuffizienz. 2). Laboruntersuchung auf Erreger: Influenza-A-Virus H1N1 (11 Fälle), Influenza-B-Virus (9 Fälle), Adenovirus (3 Fälle) und Mycoplasma pneumoniae (2 Fälle). Es fand sich kein statistisch signifikanter Unterschied (P>0,05) zwischen Kindern, die ein "gewöhnliches" NS mit komplizierender Influenza-Virus (IV)-Infektion (ohne begleitende Atemnot) aufwiesen, und Kindern mit Nierenerkrankung, die eine PB entwickelten, hinsichtlich der Leukozyten- und Lymphozytenwerte sowie der Entzündungsmarker C-reaktives Protein (CRP), Procalcitonin (PCT) und humorale Immunität (IgG-Wert). Allerdings wurde bei der letzteren Patientengruppe ein signifikant höherer Gesamt-IgG-Wert und ein signifikant niedriger Albumin-Spiegel im Blut nachgewiesen (P<0.05). 3). Bei allen 25 Kindern erfolgte eine FOB und Therapie mit Lavage, bei 15 Kinder fanden sich typische verzweigte Ausgüsse der Bronchialäste und bei 10 Patienten desintegrierte und zähe Ausgüsse. Gemäß der histopathologischen Klassifikation waren alle Kinder vom Typ I. 4). Zwanzig Kinder (80%) mit Influenza erhielten das Virostatikum Oseltamivir, 20 Kinder (80%) eine Antibiotikatherapie, in 5 Fällen (20%) wurden oral gegebene Hormone durch intravenös in derselben Dosis verabreichtes Methylprednisolon ersetzt und 20 Kinder (80%) erhielten intravenös verabreichte Gammaglobuline (400-500 mg/kg Körpergewicht x 3 Tage). Diese Kinder zeigten eine bemerkenswerte Verbesserung nach der Therapie und es traten keine Todesfälle auf. SCHLUSSFOLGERUNG: Bei Kindern mit NS besteht ein hohes Risiko für eine Influenza-Virus-Infektion. Kinder mit schwerem NS sind anfälliger für PB. Bei Auftreten von Symptomen wie Atemnot, Giemen und Brummern sowie progredienter bidirektionaler Dyspnoe sollte baldmöglichst eine FOB-Untersuchung und eine therapeutische Lavage durchgeführt werden. Erhöhte IgE-Werte im Blut und Hypoproteinämie stellen möglicherweise Risikofaktoren für PNS mit komplizierender PB im Kindesalter dar.
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Bronquitis , Subtipo H1N1 del Virus de la Influenza A , Síndrome Nefrótico , Bronquitis/diagnóstico , Bronquitis/tratamiento farmacológico , Niño , Humanos , Síndrome Nefrótico/diagnóstico , Síndrome Nefrótico/tratamiento farmacológico , Plásticos , Estudios RetrospectivosRESUMEN
Although significant improvements have been achieved for organic photovoltaic cells (OPVs), the top-performing devices still show power conversion efficiencies far behind those of commercialized solar cells. One of the main reasons is the large driving force required for separating electron-hole pairs. Here, we demonstrate an efficiency of 14.7% in the single-junction OPV by using a new polymer donor PTO2 and a nonfullerene acceptor IT-4F. The device possesses an efficient charge generation at a low driving force. Ultrafast transient absorption measurements probe the formation of loosely bound charge pairs with extended lifetime that impedes the recombination of charge carriers in the blend. The theoretical studies reveal that the molecular electrostatic potential (ESP) between PTO2 and IT-4F is large, and the induced intermolecular electric field may assist the charge generation. The results suggest OPVs have the potential for further improvement by judicious modulation of ESP.
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Suministros de Energía Eléctrica , Compuestos Orgánicos/química , Energía Solar , Electricidad Estática , Transporte de Electrón , Fulerenos/química , Modelos Moleculares , Conformación Molecular , Polímeros/químicaRESUMEN
Polymer topology exerts a significant effect on its properties and performance for potential applications. Cyclic topology and its derived structures have been recently shown to outperform conventional linear analogues for drug delivery applications. However, an amphiphilic tadpole-shaped copolymer consisting of a cylic hydrophobic moiety has rarely been explored. For this purpose, a tadpole-shaped amphiphilic diblock copolymer of poly(ethylene oxide)-b-(cyclic poly(ε-caprolactone)) (mPEG-b-cPCL) was synthesized successfully via ring-opening polymerization (ROP) of ε-CL using a mPEG-based macroinitiator with both a hydroxyl and an azide termini and subsequent intrachain Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAc) click cyclization. A comparison study on the self-assembly behaviors, in vitro drug loading and drug release profiles, and degradation properties of the resulting mPEG-b-cPCL (C) with those of the linear counterpart (mPEG-b-PCL, L) revealed that mPEG-b-cPCL micelles are a better formulation than the micelles formed by the linear counterparts in terms of micelle stability, drug loading capacity, and the degradation property. Interestingly, compared to the single degradation of L, C exhibited a slower two-stage degradation process including the topological change from tadpole shape to linear conformation and the subsequent degradation of a linear polymer. This study therefore uncovered the topological effect of a hydrophobic moiety on the properties of the self-assembled micelles and developed a complementary alternative to enhance the micelle stability by introducing a cyclic hydrophobic segment.
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Portadores de Fármacos/química , Micelas , Poliésteres/química , Preparaciones de Acción Retardada , Doxorrubicina/química , Células HeLa , Humanos , Cinética , Polietilenglicoles/químicaRESUMEN
Owing to the increasing environmental awareness, nanocellulose/natural clay composites with improved mechanical performance have attracted growing interest due to their eco-friendly properties. In this study, hybrid films composed of cellulose fibers (CFs) and imogolite nanotubes (natural aluminosilicate nanotubes) were fabricated. We mainly studied the structure, density, and properties of the hybrid materials. Specifically, the hybrid materials were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA), a rheological test, and wide-angle X-ray diffraction (WAXD). The mechanical properties of the hybrid materials were measured by a tensile test, which demonstrated that the mechanical properties of the hybrid films were considerably improved by the addition of imogolite up to 1 wt %; meanwhile, the thermal-mechanical properties of the hybrid film were also enhanced.
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Celulosa/química , Nanocompuestos/ultraestructura , Nanotubos/química , Silicatos de Aluminio/química , Celulosa/ultraestructura , Microscopía de Fuerza Atómica , Microscopía Electrónica de Rastreo , Nanocompuestos/química , Nanotubos/ultraestructura , Espectroscopía Infrarroja por Transformada de Fourier , Termogravimetría , Difracción de Rayos XRESUMEN
BACKGROUND: Hand, foot and mouth disease (HFMD) is a serious infectious disease, which has become a public health problem. Previous studies have shown that temperature may influence the incidence of HFMD, but most only focus on single city and the results are highly heterogeneous. Therefore, a multicity study was conducted to explore the association between temperature and HFMD in different cities and search for modifiers that influence the heterogeneity. METHODS: We collected daily cases of childhood HFMD (aged 0-5 years) and meteorological factors of 21 cities in Guangdong Province in the period of 2010-2013. Distributed lag non-linear model (DLNM) with quasi-Poisson was adopted to quantify the effects of temperature on HFMD in 21 cities. Then the effects of each city were pooled by multivariate meta-analysis to obtain the heterogeneity among 21 cities. Potential city-level factors were included in meta-regression to explore effect modifiers. RESULTS: A total of 1,048,574 childhood cases were included in this study. There was a great correlation between daily childhood HFMD cases and temperature in each city, which was non-linear and lagged. High heterogeneity was showed in the associations between temperature and HFMD in 21 cities. The pooled temperature-HFMD association was peaking at the 79th percentile of temperature with relative risk (RR) of 2.474(95% CI: 2.065-2.965) as compared to the median temperature. Latitude was the main modifier for reducing the heterogeneity to 69.28% revealed by meta-analysis. CONCLUSIONS: There was a strong non-linear and lagged correlation between temperature and HFMD. Latitude was strongly associated with the relationship between temperature and HFMD. Meanwhile, it had an effect on modifying the relationship. These findings can conducive to local governments developing corresponding preventive measures.
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Enfermedad de Boca, Mano y Pie/diagnóstico , Preescolar , China/epidemiología , Ciudades , Enfermedad de Boca, Mano y Pie/epidemiología , Humanos , Incidencia , Lactante , Recién Nacido , Salud Pública , Riesgo , TemperaturaRESUMEN
OBJECTIVE: Guangdong province is one of the provinces most frequently hit by tropical cyclones in China. Hand, foot and mouth disease (HFMD) continues to severely affect public health across the world. Our study aimed to evaluate the impacts of different grades of tropical cyclones and accompanying precipitation and wind velocity on HFMD among children younger than 6 years old in Guangdong province from 2009 to 2013. METHODS: A time-stratified case-crossover design was used to examine the association between tropical cyclones and childhood HFMD. Principal component analysis (PCA) was first used to eliminate multicollinearity among meteorological variables. Conditional Poisson regression was then applied to calculate odds ratios (ORs) and the 95% confidence intervals (CIs). RESULTS: Tropical storms increased the risk of HFMD among children below 6 years of age on lag 4 days (ORâ¯=â¯1.55, 95%CI: 1.28-1.88). Tropical storms were also a risk factor for boys below 3 years of age, boys between 3 and 6 and girls below 3 years of age with the largest ORâ¯=â¯1.52 (95%CI:1.15-2.00), ORâ¯=â¯1.81 (95%CIâ¯=â¯1.21-2.71) and ORâ¯=â¯1.51 (95%CIâ¯=â¯1.04-2.19), respectively. Precipitation during tropical cyclones had an adverse effect on childhood HFMD when reaching 25-49.9â¯mm or above 100â¯mm with ORâ¯=â¯1.20 (95%CIâ¯=â¯1.00-1.43) on lag 0 day and ORâ¯=â¯1.25 (95%CIâ¯=â¯1.04-1.49) on lag 7 days, respectively. For extreme wind velocity during tropical cyclones, the impact on childhood HFMD was largest on the day tropical cyclones landed (ORâ¯=â¯1.25, 95%CI: 1.06-1.48) with winds up to 13.9-24.4â¯â¯m/s. CONCLUSIONS: Tropical storms can increase the risk of HFMD among children younger than 3 years old, especially boys between 3 and 6 years old. Precipitation during tropical cyclones is a risk factor for childhood HFMD when it is between 25 and 49.9â¯mm or above 100â¯mm. As extreme wind velocity reaches 13.9-24.4â¯â¯m/s, it has an adverse effect on children's health. Children below 3 years old and boys between 3 and 6 should be given more consideration during tropical storms.
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Tormentas Ciclónicas , Exposición a Riesgos Ambientales/estadística & datos numéricos , Enfermedad de Boca, Mano y Pie/epidemiología , Niño , Preescolar , China/epidemiología , Femenino , Humanos , Incidencia , Lactante , Masculino , Oportunidad Relativa , Temperatura , VientoRESUMEN
A simple, small-bandgap porphyrin-based conjugated polymer with ethylnyl linkers is prepared for application in organic electronics. Beneficial from quinoid resonance form, the polymer showed near-infrared absorption up to 1000 nm and strong photoluminescence emission with a quantum yield of 0.2%. The polymer can be successfully applied to several electronic devices, such as organic field-effect transistors with ambipolar charge transport, organic solar cells with a high external quantum efficiency of 0.58 at 970 nm, and organic photodetectors with high responsibility and detectivity.
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Metaloporfirinas/química , Polímeros/química , Porfirinas/química , Acetileno/química , Electrónica , Luminiscencia , Metaloporfirinas/síntesis química , Estructura Molecular , Procesos Fotoquímicos , Polímeros/síntesis química , Transistores Electrónicos , Zinc/químicaRESUMEN
Novel red and purple reactive disperse silicon-containing dyes were designed and synthesized using p-nitroaniline and 6-bromo-2,4-dinitro-aniline as diazonium components, the first condensation product of cyanuric chloride and 3-(N,N-diethyl)amino-aniline as coupling component, and 3-aminopropylmethoxydimethylsilane, 3-aminopropylmethyldimethoxysilane, and 3-aminopropyltrimethoxysilane as silicone reactive agents. These dyes were characterized by UV-Vis, ¹H-NMR, FT-IR, and MS. The obtained reactive disperse silicon-containing dyes were used to color silicone rubbers and the color fastness of the dyes were evaluated. The dry/wet rubbing and washing fastnesses of these dyes all reached 4-5 grade and the sublimation fastness was also above 4 grade, indicating outstanding performance in terms of color fastness. Such colored silicone rubbers showed bright and rich colors without affecting its static mechanical properties.
Asunto(s)
Compuestos de Anilina/química , Colorantes/síntesis química , Propilaminas/química , Silanos/química , Elastómeros de Silicona/química , Color , Estructura Molecular , Espectroscopía de Protones por Resonancia Magnética/métodos , Espectrofotometría/métodos , Espectroscopía Infrarroja por Transformada de Fourier/métodos , Relación Estructura-ActividadRESUMEN
The halogen-free solvent additive, 1,4-butanedithiol (BT) has been incorporated into PTB7-Th:PC71 BM, leading to higher power conversion efficiency (PCE) value as well as substantially enhanced thermal stability, as compared with the traditional 1,8-diiodooctane (DIO) additive. More importantly, the improved thermal stability after processing with BT contributes to a higher glass transition temperature (Tg ) of PTB7-Th, as determined by dynamic mechanical analysis. After thermal annealing at 130 °C in nitrogen atmosphere for 30 min, the PCE of the specimen processed with BT reduces from 9.3% to 7.1%, approaching to 80% of its original value. In contrast, the PCE of specimens processed with DIO seriously depresses from 8.3% to 3.8%. These findings demonstrate that smart utilization of low-boiling-point solvent additive is an effective and practical strategy to overcome thermal instability of organic solar cells via enhancing the Tg of donor polymer.
Asunto(s)
Octanos/química , Polímeros/química , Solventes/química , Compuestos de Sulfhidrilo/química , Transición de Fase , Energía Solar , Temperatura de TransiciónRESUMEN
Chiral solid membranes of cellulose, sodium alginate, and hydroxypropyl-ß-cyclodextrin were prepared for chiral dialysis separations. After optimizing the membrane material concentrations, the membrane preparation conditions and the feed concentrations, enantiomeric excesses of 89.1%, 42.6%, and 59.1% were obtained for mandelic acid on the cellulose membrane, p-hydroxy phenylglycine on the sodium alginate membrane, and p-hydroxy phenylglycine on the hydroxypropyl-ß-cyclodextrin membrane, respectively. To study the optical resolution mechanism, chiral discrimination by membrane adsorption, solid phase extraction, membrane chromatography, high-pressure liquid chromatography ultrafiltration were performed. All of the experimental results showed that the first adsorbed enantiomer was not the enantiomer that first permeated the membrane. The crystal structures of mandelic acid and p-hydroxy phenylglycine are the racematic compounds. We suggest that the chiral separation mechanism of the solid membrane is "adsorption - association - diffusion," which is able to explain the optical resolution of the enantioselective membrane. This is also the first report in which solid membranes of sodium alginate and hydroxypropyl-ß-cyclodextrin were used in the chiral separation of p-hydroxy phenylglycine.
Asunto(s)
2-Hidroxipropil-beta-Ciclodextrina/química , Alginatos/química , Celulosa/química , Membranas Artificiales , Fenómenos Ópticos , Cromatografía Líquida de Alta Presión , Ácido Glucurónico/química , Glicina/análogos & derivados , Glicina/química , Glicina/aislamiento & purificación , Ácidos Hexurónicos/química , EstereoisomerismoRESUMEN
In order to facilely achieve pretreatment and salt-free dyeing of greige knitted cotton fabrics, a combinative scouring, bleaching, and cationization pretreatment of the fabrics is designed in this study. The fabrics are first treated in a bath containing commercial scouring and bleaching agents, and then glycidyltrimethylammonium chloride (GTA) is directly added into the bath to achieve cationization of the fabrics. Utilization of the alkaline and high-temperature conditions in scouring and bleaching process, cationization can facilely proceed in a short time. Optimal pretreatment conditions are as follows: greige knitted cotton fabrics are treated in a bath containing 4 g/L scouring agent and 6 g/L 30% hydrogen peroxide at 90 °C for 60 min, and then 30 g/L GTA and 3 g/L sodium hydroxide are added in the bath for another 15 min treatment. Fiber performances, including whiteness, water absorptivity, diffusion time, and capillary effect, are tested and evaluated. X-ray diffraction analysis, surface morphology, and thermal analysis of the pretreated cotton are also investigated and compared with that treated only with scouring and bleaching agents. Much higher dye fixation and color yield could be realized on the pretreated cotton in salt-free reactive dyeing. Colorimetric properties of the dyes are studied and good colorfastness of the dyes on the cationic fabrics are obtained. All of the above results show promising prospects of this combinative pretreatment in real application.