Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 35
Filtrar
1.
Environ Res ; 237(Pt 1): 116962, 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-37619634

RESUMO

It is of great significance to develop the effective technique to treat phenol-containing wastewater. Herein, Fe-based prussian blue analogues-derived zero valent iron (ZVI) was successfully synthesized by one-step calcination method. Owing to high specific surface area and rich active sites, ZVI-2 possessed excellent performance in charge transfer. Notably, in comparison with conventional ZVI and Fe2+, ZVI-2 can effectively activate peroxymonosulfate (PMS) for achieving rapid degradation of phenol, and the highest removal efficiency of phenol reached 94.9% within 24 min. More importantly, developed ZVI-2/PMS oxidation system with good stability displayed strong anti-interference capability. Interestingly, Fe0 loaded on the surface of ZVI-2 can efficiently break the O-O bond of PMS to generate reactive oxygen species (i.e., SO4•-, OH•, O2•- and 1O2). As main adsorption sites of PMS, the existence of oxygen vacancy promote the formation of high-valent transition metal complexes (namely ZVI-2≡Fe4+=O). Under the combined action of reactive oxygen species and ZVI-2≡Fe4+=O, phenol can be eventually degraded into CO2 and H2O. The possible degradation pathways of phenol were also investigated. Furthermore, proposed ZVI-2/PMS oxidation system displayed great potential for application in the field of wastewater treatment. All in all, current work provided a valuable reference for design and application of Fe-based catalysts in PS-AOPs.

2.
Mikrochim Acta ; 190(12): 494, 2023 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-38036868

RESUMO

An antifouling electrochemical biosensor was constructed based on chondroitin sulfate (CS)-functionalized polyaniline (CS/PANI) and DNA-peptide conjugates that is capable of assaying cortisol directly in human fluids. First, a CS-doped PANI nanocomposite (sensing substrate) was electrodeposited onto a bare glassy carbon electrode to promote electron transport, providing the sensing signal from high peak currents of PANI to improve the sensitivity of the biosensor. Dendritic DNA-peptide conjugates were assembled onto the CS/PANI by exploiting the highly specific and strong interactions between biotin and streptavidin, which amplified the sensing signals toward cortisol. The integration of the DNA-peptide conjugates into the CS/PANI nanocomposite ensured that the biosensor had a synergistic antifouling effect and was capable of detecting cortisol directly in body fluids (sweat, saliva, and tears). When assaying cortisol levels, the biosensor exhibited a linear range over the cortisol concentrations of 1 × 10-12-1 × 10-7 M and a low limit of detection (0.333 × 10-12 M). In the detection of cortisol in real samples, the relative standard deviation (RSD) of the biological samples ranged from 2.94 to 4.23%, and the recovery were calculated to be in the range 95.2-103.2%.


Assuntos
Incrustação Biológica , Técnicas Biossensoriais , Líquidos Corporais , Humanos , Hidrocortisona , Sulfatos de Condroitina , Incrustação Biológica/prevenção & controle , DNA , Peptídeos
3.
Mikrochim Acta ; 189(10): 395, 2022 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-36169733

RESUMO

Dual-mode electrochemical aptasensor based on nitrogen-doped graphene (NG) doped with the conducting polymer polypyrrole (PPy) nanocomposite is proposed for the determination of acetamiprid. NG/PPy was electrodeposited onto the glassy carbon electrode (GCE) using cyclic voltammetry technique. NG/PPy/GCE showed outstanding electrocatalytic activity for the oxidation of nitrite due to "active region" induced by the charge redistribution of carbon atoms. The ultrasensitive dual-mode biosensor for acetamiprid could be easily developed by coupling acetamiprid aptamers with the NG/PPy hybrid. The specific binding between acetamiprid and the aptamers resulted in the increase of differential pulse voltammetry (DPV) signal change and the decrease of chronoamperometry (CA) signal, and the concentration of acetamiprid could be measured. The working potentials of DPV and CA were - 0.2 ~ 0.4 V and - 0.4 ~ 0.4 V (vs. SCE), respectively. The dual-mode acetamiprid biosensor showed a wide linear range from 10-12 to 10-7 g mL-1, with low detection limits of 1.15 × 10-13 g mL-1 and 7.32 × 10-13 g mL-1 through DPV and CA modes, respectively. Moreover, owing to high active area and superior conductivity, as well as good electrocatalytic ability, the dual-sensing platform based on NG/PPy nanocomposite supported the quantification of acetamiprid in complex samples. A dual-mode electrochemical aptasensor based on NG/PPy nanocomposite for acetamiprid detection was proposed through both the increase of differential pulse voltammetry (DPV) signal change and the decrease of chronoamperometry (CA) signal of the nitrite oxidation electrocatalyzed by NG/PPyn in sensors and biosensors.


Assuntos
Grafite , Nanocompostos , Carbono , Técnicas Eletroquímicas/métodos , Limite de Detecção , Neonicotinoides , Nitritos , Nitrogênio , Polímeros , Pirróis , Verduras
4.
Molecules ; 27(21)2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-36364239

RESUMO

A robust metal- and solvent-free cascade radical-induced C-N cleavage/intramolecular 6-endo-dig annulation/hydrocarbonylation for the synthesis of the valuable 2-aryl-4H-chromen-4-ones is described. This practical synthesis strategy utilizes propargylamines and air as the oxygen source and green carbonylation reagent, in which propargylamines are activated by the inexpensive and available dimethyl 2,2'-azobis(2-methylpropionate) (AIBME) and (PhSe)2 as the radical initiators. This simple and green protocol features wide substrate adaptability, good functional group tolerance, and amenability to scaling up and derivatizations.


Assuntos
Ésteres , Ésteres/química , Radicais Livres
5.
Plant Biotechnol J ; 19(3): 517-531, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-32946650

RESUMO

The Chinese jujube (Ziziphus jujuba Mill.), a member of the Rhamnaceae family, is an important perennial fruit tree crop of substantial economic, ecological and nutritional value, and is also used as a traditional herbal medicine. Here, we report the resequencing of 493 jujube accessions, including 202 wild and 291 cultivated accessions at >16× depth. Our population genomic analyses revealed that the Shanxi-Shaanxi area of China was jujube's primary domestication centre and that jujube was then disseminated into East China before finally extending into South China. Divergence events analysis indicated that Ziziphus acidojujuba and Ziziphus jujuba diverged around 2.7 Mya, suggesting the interesting possibility that a long pre-domestication period may have occurred prior to human intervention. Using the large genetic polymorphism data set, we identified a 15-bp tandem insertion in the promoter of the jujube ortholog of the POLLEN DEFECTIVE IN GUIDANCE 1 (POD1) gene, which was strongly associated with seed-setting rate. Integrating genome-wide association study (GWAS), transcriptome data, expression analysis and transgenic validation in tomato, we identified a DA3/UBIQUITIN-SPECIFIC PROTEASE 14 (UBP14) ortholog, which negatively regulate fruit weight in jujube. We also identified candidate genes, which have likely influenced the selection of fruit sweetness and crispness texture traits among fresh and dry jujubes. Our study not only illuminates the genetic basis of jujube evolution and domestication and provides a deep and rich genomic resource to facilitate both crop improvement and hypothesis-driven basic research, but also identifies multiple agriculturally important genes for this unique perennial tree fruit species.


Assuntos
Ziziphus , China , Frutas/genética , Estudo de Associação Genômica Ampla , Genômica , Ziziphus/genética
6.
J Org Chem ; 86(5): 4182-4192, 2021 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-33625853

RESUMO

A novel and versatile approach to construct 12-phenacyl-11H-benzo[b]xanthene-6,11(12H)-dione derivatives through copper-catalyzed cascade reaction of propargylamines with 2-hydroxynaphthalene-1,4-diones has been developed. The procedure is proposed to go through a sequence of 1,4-conjugate addition, intramolecular nucleophilic addition/dehydration, and hydrolysis of alkyne followed by an enol-ketone tautomerization. The reaction provides a new and highly efficient method for the synthesis of 12-phenacyl-11H-benzo[b]xanthene-6,11(12H)-diones by formation of three new bonds and one heterocycle from readily available starting materials in good to high yields (70-88%) with broad functional group compatibility in a single step.


Assuntos
Cobre , Xantenos , Catálise , Hidrólise , Naftóis , Pargilina/análogos & derivados , Propilaminas
7.
Med Sci Monit ; 25: 1362-1372, 2019 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-30785872

RESUMO

BACKGROUND Osteoblastoma is a rare, benign, osteolytic neoplasm commonly found in the spine in early adulthood. Here, we review the clinical characteristics, radiographic findings, and surgical management of patients with spinal osteoblastoma. MATERIAL AND METHODS Thirteen patients with osteoblastoma who underwent surgery at our institute from June 2008 to November 2017 were enrolled in this study. The American Spinal Injury Association (ASIA) impairment scale was used to assess neurological function. All patients were treated with either total excision or intralesional piecemeal excision without postoperative radiotherapy. Clinical efficacy was evaluated by visual analog scale (VAS) scores, the Oswestry Disability Index (ODI) of nerve function, physical and radiographic examinations, bone fusion, and neurologic status. RESULTS The follow-up lasted 23-82 months (average, 43.8 months). The average surgical time was 178.1 minutes (range, 100-230 minutes), with an average intraoperative blood loss of 574 mL (range, 230-1100 mL). Postoperatively, VAS scores decreased from 6.2±1.7 to 0.5±0.7 (P<0.001). The preoperative and final ODI scores were 51.1±7.7 and 22.6±4.9, respectively, reflecting a significant decrease (P<0.001). According to the ASIA classification, 3 patients had grade C, 3 patients had grade D, and 7 patients had grade E disease. Three months postoperatively, 1 patient had grade D and 10 patients had grade E disease; ultimately, all cases were grade E disease. Only 1 patient experienced local recurrence and underwent en bloc marginal resection with postoperative radiotherapy. All patients remained neurologically stable without any major complications. CONCLUSIONS Accurate intraoperative localization with complete resection is the key to preventing recurrence. Aggressive surgical resection can achieve satisfactory clinical and radiographic outcomes.


Assuntos
Osteoblastoma/diagnóstico , Osteoblastoma/terapia , Adolescente , Adulto , Idoso , Neoplasias Ósseas/cirurgia , Criança , China , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/cirurgia , Procedimentos de Cirurgia Plástica , Estudos Retrospectivos , Coluna Vertebral/cirurgia , Resultado do Tratamento
8.
Clin Exp Ophthalmol ; 42(4): 379-84, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-23952961

RESUMO

BACKGROUND: The prevalence of refractive error in the north of China is unknown. The study aimed to estimate the prevalence and associated factors of refractive error in school-aged children in a rural area of northern China. DESIGN: Cross-sectional study. PARTICIPANTS OR SAMPLES: The cluster random sampling method was used to select the sample. METHODS: A total of 1700 subjects of 5 to 18 years of age were examined. All participants underwent ophthalmic evaluation. Refraction was performed under cycloplegia. Association of refractive errors with age, sex, and education was analysed. MAIN OUTCOME MEASURES: The main outcome measure was prevalence rates of refractive error among school-aged children. RESULTS: Of the 1700 responders, 1675 were eligible. The prevalence of uncorrected, presenting, and best-corrected visual acuity of 20/40 or worse in the better eye was 6.3%, 3.0% and 1.2%, respectively. The prevalence of myopia was 5.0% (84/1675, 95% CI, 4.8%-5.4%) and of hyperopia was 1.6% (27/1675, 95% CI, 1.0%-2.2%). Astigmatism was evident in 2.0% of the subjects. Myopia increased with increasing age, whereas hyperopia and astigmatism were associated with younger age. Myopia, hyperopia and astigmatism were more common in females. We also found that prevalence of refractive error were associated with education. Myopia and astigmatism were more common in those with higher degrees of education. CONCLUSION: This report has provided details of the refractive status in a rural school-aged population. Although the prevalence of refractive errors is lower in the population, the unmet need for spectacle correction remains a significant challenge for refractive eye-care services.


Assuntos
Erros de Refração/epidemiologia , População Rural/estatística & dados numéricos , Adolescente , Distribuição por Idade , Criança , Pré-Escolar , China/epidemiologia , Estudos Transversais , Escolaridade , Feminino , Pesquisa sobre Serviços de Saúde , Inquéritos Epidemiológicos , Humanos , Masculino , Prevalência , Erros de Refração/diagnóstico , Fatores de Risco , Distribuição por Sexo , Testes Visuais , Acuidade Visual
9.
Sci Rep ; 13(1): 4454, 2023 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-36932148

RESUMO

Because the traditional Cholesky decomposition algorithm still has some problems such as computational complexity and scattered structure among matrices when solving the GNSS ambiguity,  it is the key problem to further improve the computational efficiency of the least squares ambiguity reduction correlation process in the carrier phase integer ambiguity solution. But the traditional matrix decomposition calculation is more complex and time-consuming, to improve the efficiency of the matrix decomposition, in this paper, the decomposition process of traditional matrix elements is divided into two steps: multiplication update and column reduction of square root calculation. The column reduction step is used to perform square root calculation and column division calculation, while the update step is used for the update task of multiplication. Based on the above ideas, the existing Cholesky decomposition algorithm is improved, and a column oriented Cholesky (C-Cholesky) algorithm is proposed to further improve the efficiency of matrix decomposition, so as to shorten the calculation time of integer ambiguity reduction correlation. The results show that this method is effective and superior, and can improve the data processing efficiency by about 12.34% on average without changing the integer ambiguity accuracy of the traditional Cholesky algorithm.

10.
Sci Rep ; 13(1): 10158, 2023 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-37349520

RESUMO

The Moon is the closest natural satellite to mankind, with valuable resources on it, and is an important base station for mankind to enter deep space. How to establish a reasonable lunar Global Navigation Satellite System (GNSS) to provide real-time positioning, navigation, and timing (PNT) services for Moon exploration and development has become a hot topic for many international scholars. Based on the special spatial configuration characteristics of Libration point orbits (LPOs), the coverage capability of Halo orbits and Distant Retrograde Orbit (DRO) in LPOs is discussed and analyzed in detail. It is concluded that the Halo orbit with a period of 8 days has a better coverage effect on the lunar polar regions and the DRO has a more stable coverage effect on the lunar equatorial regions, and the multi-orbital lunar GNSS constellation with the optimized combination of DRO and Halo orbits is proposed by combining the advantages of both. This multi-orbital constellation can make up for the fact that a single type of orbit requires a larger number of satellites to fully cover the Moon, using a smaller number of satellites for the purpose of providing PNT services to the entire lunar surface. We designed simulation experiments to test whether the multi-orbital constellations meet the full lunar surface positioning requirements, and compare the coverage, positioning, and occultation effects of the four constellation designs that pass the test, and finally obtain a set of well-performing lunar GNSS constellations. The results indicate that the multi-orbital lunar GNSS constellation combining DRO and Halo orbits can cover 100% of the Moon surface, provides there are more than 4 visible satellites at any time on the Moon surface, which meets the navigation and positioning requirements, and the Position Dilution of Precision (PDOP) value is stable within 2.0, which can meet the demand for higher precision Moon surface navigation and positioning.


Assuntos
Lua , Órbita , Simulação por Computador , Técnicas de Diluição do Indicador
11.
Front Vet Sci ; 10: 1314903, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38146498

RESUMO

The infectious bursal disease virus (IBDV) is a member of the viruses that can induce immunosuppression in chickens. In recent years, more and more IBDV-infected cases by the novel variant IBDV were reported in China, and it has been demonstrated that currently used vaccines could not provide complete protection against these new IBDV variants. However, a lack of comprehensive analysis of the genomic characteristics of the novel variant strain IBDV has hampered its vaccine development. In this study, a strain of IBDV, designated HB202201, was phylogenetically analyzed, and it was found that the hypervariable region (HVR) of VP2 belonged to the novel variant strain. Furthermore, the 5'- and 3'-ends of segments A and B were analyzed using the rapid amplification of cDNA end (RACE) method. After the full-length of segment A and segment B were determined, the phylogenetic analysis of the segment A and segment B showed that the isolated HB202201 belonged to A2dB1 genotype, which demonstrated the HB202201 belonged to the novel variant strain. In addition, the specific mutations in VP1-VP5 amino acids were analyzed, which showed that there were multiple typical mutations in novel variant IBDV proteins, including VP1 (G24, I141, V163, and E240), VP2 (K221, and I252), VP3 (Q167 and L196), and VP5 (R7, P44, R92, G104, and E147), whereas there was no typical mutation in VP4. This study provides insights into the genomic and antigenic characteristics of the novel variant IBDV, which will promote the development of novel vaccine against the novel variant IBDV.

12.
J Hazard Mater ; 458: 132010, 2023 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-37423132

RESUMO

Traditional polymeric fibrous membranes have been extensively used to reduce the health risks caused by airborne particulate matter (PM), leading to the dramatically increasing pollution of plastics and microplastics. Although great efforts have been made to develop poly(lactic acid) (PLA)-based membrane filters, they are frequently dwarfed by their relatively poor electret properties and electrostatic adsorptive mechanisms. To resolve this dilemma, a bioelectret approach was proposed in this work, strategically involving the bioinspired adhesion of dielectric hydroxyapatite nanowhiskers as a biodegradable electret to promote the polarization properties of PLA microfibrous membranes. In addition to significant improvements in tensile properties, the incorporation of hydroxyapatite bioelectret (HABE) enabled remarkable increase in the removal efficiencies of ultrafine PM0.3 in a high-voltage electrostatic field (10 and 25 kV). This was exemplified by the largely increased filtering performance (69.75%, 23.1 Pa) for PLA membranes loaded with 10 wt% HABE at the normal airflow rate (32 L/min) compared to the pristine PLA counterpart (32.89%, 7.2 Pa). Although the filtration efficiency of PM0.3 for the counterpart dramatically decreased to 21.6% at 85 L/min, the increment was maintained at nearly 196% for the bioelectret PLA, while an ultralow pressure drop (74.5 Pa) and high humidity resistance (RH 80%) were achieved. The unusual property combination were ascribed to the HABE-enabled realization of multiple filtration mechanisms, including the simultaneous enhancement of physical interception and electrostatic adsorption. The significant filtration applications, unattainable with conventional electret membranes, demonstrate the bioelectret PLA as a promising biodegradable platform that allows high filtration properties and humidity resistance.

13.
Int J Biol Macromol ; 226: 1273-1283, 2023 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-36442566

RESUMO

Biomimetic mineralization of high-strength apatite structure essentially relies on mimicking the inorganic building blocks of naturally occurring bones. However, conventional routes still have substantial function gaps in providing precision control over the geometrical dimensions and crystalline morphology of biomineralized apatite. Herein, we conceived the concept of microwave-assisted biomineralization (MAB) to customize 1D hydroxyapatite nanowhiskers (HANWs) at graphene templates, rendering the formation of graphene-hydroxyapatite (Gr-HA) nanohybrids. The HANWs essentially resembled bone apatite in elemental composition (Ca/P = 1.74), diameter (~20 nm), crystallinity (63 %), and rodlike geometry (aspect ratio of ~6). The Gr-HA nanohybrids were uniformly incorporated into poly(lactic acid) (PLA) microfibers (~1 µm) by electrospinning, engendering fibrous membranes with a set of Gr-HA loadings (10, 20 and 30 wt%). Intimate interactions were generated between Gr-HA and PLA matrix, contributing to significant promotion of the mechanical properties for PLA composite membranes. For example, the yield strength and elastic modulus of the PLA composite membranes loaded with 30 wt% Gr-HA achieved 5.4 and 66.4 MPa, increasing nearly 182 % and over 94 % compared to those of pure PLA, respectively. Moreover, the bone-like HANWs endowed PLA membranes with excellent cytocompatibility and good bioactivity, as demonstrated by over 38 % increase in cell viability and rapid apatite formation in mineral solution. The impressive combination of mechanical properties and biological characteristics make the PLA/Gr-HA scaffolds promising for guided tissue/bone regeneration therapy.


Assuntos
Durapatita , Grafite , Durapatita/química , Alicerces Teciduais/química , Biomineralização , Engenharia Tecidual/métodos , Poliésteres/química
14.
Front Nutr ; 9: 890357, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35719141

RESUMO

Background: Gut microbiota has been identified as an imbalance in patients with irritable bowel syndrome (IBS). Fecal microbiota transplantation (FMT) is a novel method to restore microbiota and treat IBS patients. Objective: To conduct a meta-analysis and estimate the efficacy and safety of FMT for the treatment of IBS patients with subgroup analyses to explore the most effective way of FMT for IBS. Methods: All eligible studies were searched from PubMed, Embase, Web of Science, and the Cochrane Library through multiple search strategies. Data were extracted from studies comprising the following criteria: double-blind, randomized controlled trials (RCTs) that compared the efficacy of FMT with placebo for adult patients (≥18 years old) with IBS. A meta-analysis was performed to evaluate the summary relative risk (RR) and 95% confidence intervals (CIs). Results: A total of seven RCTs comprising 489 subjects were eligible for this meta-analysis. Pooled data showed no significant improvement of global IBS symptoms in patients with FMT compared with placebo (RR = 1.34; 95% CI 0.75-2.41, p = 0.32). A significant heterogeneity was observed among the studies (I 2 = 83%, p < 0.00001). There was no significant evidence of funnel plot asymmetry (Egger's test, p = 0.719; Begg's test, p = 1.000), indicating no existence of publication bias. Subgroup analyses revealed that FMT operated by invasive routes, including gastroscope, colonoscope, and nasojejunal tube, significantly improved global IBS symptoms (RR = 1.96; 95% CI 1.23-3.11, p = 0.004) with heterogeneity (I 2 = 57%, p = 0.06) and an NNT of 3 (95% CI 2-14). However, FMT delivered via oral capsules showed a negative impact on patients with IBS (RR = 0.56; 95% CI 0.33-0.96, p = 0.03) with a low heterogeneity (I 2 = 39%, p = 0.2) and an NNH of 3 (95% CI 2-37). Conclusion: The current evidence from RCTs with all routes of FMT does not show significant global improvement in patients with IBS. However, FMT operated by invasive routes significantly improved global IBS symptoms.

15.
Chem Sci ; 13(45): 13617-13622, 2022 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-36507178

RESUMO

ortho-Alkynyl quinone methides are well-known four-atom synthons for direct [4 + n] cycloaddition in constructing useful oxa-heterocyclic compounds owing to their high reactivity as well as the thermodynamically favored aromatization nature of this process. Herein we report an operationally simple and eco-friendly protocol for the modular and regioselective access of (E)-4-(vinyl or aryl or alkynyl)iminochromenes from propargylamines and S-methylated ß-ketothioamides in the presence of FeCl3, and particularly under undried acetonitrile and air atmosphere conditions. This method exhibits a broad substrate scope and displays nice functional group compatibility, thus providing an efficient access of 3,4-disubstituted iminochromenes.

16.
Int J Biol Macromol ; 222(Pt A): 927-937, 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-36183756

RESUMO

The past decades have witnessed the archetypal shift from petroleum-based to bioplastics including poly(lactic acid) (PLA) for multifunctional packaging. Here we disclose a microwave-assisted functionalization (MAF) approach to functionalize wood fibers (FWFs) at minute level and high yields (approaching 99 %), conferring high affinity to PLA matrix and significant promotion of mechanical properties. By incorporating of 10 wt% FWFs, the tensile strength and toughness of PLA composite films were elevated to 54.5 MPa and 1.6 MJ/m3, increasing nearly 28 % and over 45 % compared to those of the counterpart loaded pristine wood fibers (PWFs), respectively. It is of significance to note the FWF-enabled unique optical properties for PLA, as exemplified by approximately 100 % UV-blocking ratio (UVR) in the whole UV region with the addition of 20 wt% FWFs. By contrast, the UVR values of PWF-filled PLA (5 %-20 %) gradually decreased as the fiber contents increased, mainly ascribed to the UV reflection at the poorly bonded interfaces and relatively inferior functionality of PWFs. This distinction allowed us to fabricate UV-barrier packaging for preservation of fresh fruits, which were perishable under the UV light of sunshine. The impressive mechanical robustness and high UVR, may prompt affordable and ecofriendly PLA/FWF composites appropriate for packaging.


Assuntos
Embalagem de Alimentos , Raios Ultravioleta , Frutas , Poliésteres
17.
Mitochondrial DNA B Resour ; 6(11): 3109-3111, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34621991

RESUMO

The Lonchodinae (Phasmatodea: Phasmatidae) is rich in insect species with more than 330 species of 40 genera. The phylogenetic relationships within Lonchodinae have been under debate. We successfully sequenced the complete mitogenome of Eurycantha calcarata Lucas, 1869 (Phasmatodea: Lonchodinae) with a length of 16,280 bp, which had the same genes and gene arrangements as those of various published papers on stick insects. The whole mitogenome and control region of E. calcarata had a high AT content of 78.2 and 85.9%, respectively. All PCGs used ATN as the start codon, and most PCGs used TAA/TAG as the stop codons excluding COX2 (T), COX3 (TA), and ND5 (TA). To discuss the phylogeny of Lonchodinae, we reconstructed the phylogenetic relationships of 27 species of Phasmatodea including E. calcarata and two species of Embioptera used as outgroups. In BI and ML trees, the monophyly of Lonchodinae and Necrosciinae was well supported, whereas the monophyly of Clitumninae was not recovered. These results indicated that Lonchodinae was a sister clade to Phylliinae and E. calcarata was a sister clade to Phraortes genus.

18.
Insects ; 12(9)2021 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-34564219

RESUMO

Insects of the order Phasmatodea are mainly distributed in the tropics and subtropics and are best known for their remarkable camouflage as plants. In this study, we sequenced three complete mitochondrial genomes from three different families: Orestes guangxiensis, Peruphasma schultei, and Phryganistria guangxiensis. The lengths of the three mitochondrial genomes were 15,896 bp, 16,869 bp, and 17,005 bp, respectively, and the gene composition and structure of the three stick insects were identical to those of the most recent common ancestor of insects. The phylogenetic relationships among stick insects have been chaotic for a long time. In order to discuss the intra- and inter-ordinal relationship of Phasmatodea, we used the 13 protein-coding genes (PCGs) of 85 species for maximum likelihood (ML) and Bayesian inference (BI) analyses. Results showed that the internal topological structure of Phasmatodea had a few differences in both ML and BI trees and long-branch attraction (LBA) appeared between Embioptera and Zoraptera, which led to a non-monophyletic Phasmatodea. Consequently, after removal of the Embioptera and Zoraptera species, we re-performed ML and BI analyses with the remaining 81 species, which showed identical topology except for the position of Tectarchus ovobessus (Phasmatodea). We recovered the monophyly of Phasmatodea and the sister-group relationship between Phasmatodea and Mantophasmatodea. Our analyses also recovered the monophyly of Heteropterygidae and the paraphyly of Diapheromeridae, Phasmatidae, Lonchodidae, Lonchodinae, and Clitumninae. In this study, Peruphasma schultei (Pseudophasmatidae), Phraortes sp. YW-2014 (Lonchodidae), and species of Diapheromeridae clustered into the clade of Phasmatidae. Within Heteropterygidae, O. guangxiensis was the sister clade to O. mouhotii belonging to Dataminae, and the relationship of (Heteropteryginae + (Dataminae + Obriminae)) was recovered.

19.
Org Lett ; 23(16): 6455-6460, 2021 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-34342448

RESUMO

A DBU-mediated cascade strategy of propargylamines with dimethyl 3-oxoglutarate for constructing a functionalized benzo[c]chromen-6-one core has been achieved. This cascade process presumably involves a sequence of 1,4-conjugate addition, followed by lactonization, alkyne-allene isomerization, enol-keto tautomerization, 6π-electrocyclization, and aromatization. This protocol features mild reaction conditions, simple operation, rich structural diversity, and good functional group tolerance. A photophysical survey reveals that the benzo[c]chromen-6-one products exhibit fluorescence properties and show potential for exploring fluorescent material applications.

20.
Spectrochim Acta A Mol Biomol Spectrosc ; 240: 118626, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32604052

RESUMO

The facile preparation of highly fluorescent polymer dots (PDs) still attracts substantial interest. Here, temperature/Fe3+ dual-responsive PDs are synthesized under mild conditions via the amidation reaction and self-assembly between hyperbranched polyethyleneimine and 5-aminosalicylic acid. The prepared PDs display strong green fluorescence with quantum yield of 15.5% and 53.3% in water and dimethylsulfoxide, respectively. The PDs also possess unique features, including excellent solubility, solvent polarity-dependent emission, remarkable photostability, as well as good salt-tolerance. Interestingly, the fluorescence intensity of PDs exhibits a reversible and sensitive response to temperature within 20-65 °C, which renders the PDs useful as a thermometer probe. Importantly, Fe3+ ion has the specific coordination ability toward the surface groups of PDs, leading to the aggregation and fluorescence quenching of PDs. Thus, the PDs are employed as a fluorescence probe for sensitive detecting Fe3+. The fluorescent intensity linearly decreases with increasing Fe3+ from 2 to 60 µM. Besides, Fe3+ concentration in river water samples is successfully assayed with this developed probe. The non-conjugated PDs with facile preparation, sensitive response to temperature and Fe3+ may hold potential applications in environmental monitoring.

SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa