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Given the abundant plastics produced globally, and the negative environmental impacts of disposable plastic products throughout their life cycle, there has been significant attention drawn by the general public and governments worldwide. Mono-material multilayer packaging is a potent strategy to address the challenge of carbon emissions as it offers specific functionalities (such as strength and barrier properties) through its layers and facilitates recycling. In this study, a five-layer co-extruded polyethylene composite film LLDPE/mPE/PVA/mPE/LLDPE was taken as a model to investigate its mechanical properties and barrier properties after four recycling cycles. The result revealed that the longitudinal tensile strength and transvers tensile were, respectively, dropped from 29.66 MPa and 24.9 MPa to 21.972 MPa and 19.222 MPa after the recycling; it is shown that the film still has good mechanical properties after the recycling cycle. However, a noticeable decline in the barrier properties was observed after the second recycling. In contrast to traditional plastics, a mono-material film with a 10 wt.% circulating mass could reduce CO2 emissions by 3692.25 kg for every 1.0 ton of plastic products after four recycling cycles.
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Studying the impact of agricultural digitalization (ADT) on the carbon emission intensity of planting industry (PCI) can help promote sustainable development and realize the "dual carbon" goal. Based on the panel data of 31 provinces in China from 2010 to 2020, this study uses the entropy weight method and emission coefficient method to measure the development level of ADT and PCI, respectively. By using the regression analysis method, as well as the robustness test, heterogeneity test, and spatial spillover effect and threshold tests, the impact of ADT on PCI was examined. The results are as follow: (1) PCI is high in the north and low in the south, and the north-south divide is becoming prominent. (2) ADT in China can significantly reduce PCI, as verified through the robustness test. (3) Regional differences exist in the impact of ADT on PCI, with the most significant effect observed in the northeast region, followed by the western and central regions. (4) ADT exerts a significant spatial spillover effect on PCI and an inhibitory effect on PCI of adjacent provinces. (5) The proportion of urban population exerts a threshold effect in the impact of ADT on PCI. When the urban population ratio crosses 69 %, the inhibitory effect of agricultural carbon emissions decreases marginally. Therefore, promoting the green and low-carbon development of the planting industry is highly recommended.
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Enabling cost-effective safety monitoring of shellfish is an important measure for the healthy development of the coastal marine economy. Herein, a new aptamer@metal-organic framework (MOF)-functionalized affinity monolithic column was proposed and applied in selective in-tube solid-phase microextraction (IT-SPME) coupled with HPLC for the accurate recognition of domoic acid (DA) in shellfish. Using a surface engineering strategy, ZIF-8 MOF was grown in situ inside the poly(epoxy-MA-co-POSS-MA) hybrid monolith. A high BET surface area and abundant metal reactive sites of the MOF framework were obtained for anchoring massive aptamers with terminal-modified phosphate groups. Various characterizations, such as SEM, elemental mapping, XRD, and BET, were performed, and the affinity performance was also studied. The presence of a massive amount of aptamers with a super coverage density of 3140 µmol L-1 bound on ZIF-8 MOF activated a high-performance bionic-affinity interface, and perfect specificity was exhibited with little interference of tissue matrixes, thus assuring the highly selective capture of DA from the complex matrixes. Under the optimal conditions, DA toxins in shellfish were detected with the limit of detection (LOD) of 7.0 ng mL-1 (equivalent to 14.0 µg kg-1), representing a 5-28 fold enhancement in detection sensitivity over traditional SPE or MIP adsorbents reported previously. The recoveries of fortified mussel and clam samples were achieved as 91.8 ± 1.2%-94.1 ± 1.9% (n = 3) and 91.2 ± 1.1%-94.5 ± 3.6% (n = 3), respectively. This work sheds light on a cost-effective method for online selective IT-SPME and the accurate monitoring of DA toxins using an aptamer@MOF-mediated affinity monolith system coupled with the inexpensive HPLC-UV technique.
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Oil and natural consumption are non-renewable energy sources that are the main drivers of economic growth, but these energy sources are also the main causes of environmental degradation in Northeast Asian countries. The main objective of this study is to examine the impact of renewable energy consumption, non-renewable energy consumption on CO2 emissions, and economic growth in seven selected Northeast Asian countries during the period 1970-2020. First, the cross-sectional dependence test recommended by Pesaran, Ullah, and Yamagata (2008) concludes that there is no cross-sectional dependence in the panel data model, so it is feasible to use the first-generation panel data methods. Later, cointegration tests proposed by Pedroni (Oxford Bull Econ Stat 61:653-670, 1999, Economet Theor 20:597-625, 2004), Kao (J Econom 90:1-44, 1999), and Westerlund (2007) were adopted, revealing long-term cointegration relationships among model panel variables. Long-term variable coefficient elasticities were detected using the estimation techniques of panel fully modified ordinary least squares (FMOLS) and panel dynamic ordinary least squares (DOLS). Two-way causality of variables was detected using the Dumitrescue-Hurlin (Econ Model 29:1450-1460, 2012) panel causality test. The results of the analysis highlight the significant progressive effects of renewable energy consumption, nonrenewable energy consumption, employed labor force, and capital formation on long-run economic growth. The study also concluded that renewable energy consumption significantly reduced long-term CO2 emissions, while non-renewable energy consumption significantly contributed to long-term CO2 emissions. Estimates from the FMOLS technique reflect a significant progressive effect of GDP and GDP3 on CO2 emissions, while GDP2 has a significant adverse effect on CO2 emissions, thus validating the N-shaped EKC assumption in selected group of countries. Furthermore, the feedback hypothesis is supported based on the two-way causality between renewable energy consumption and economic growth. Strategically, this evidence-based empirical study demonstrates that renewable energy is a valuable process that can protect the environment and contribute to future economic growth in selected countries by addressing energy security and reducing carbon emissions.
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Dióxido de Carbono , Desarrollo Económico , Animales , Bovinos , Masculino , Dióxido de Carbono/análisis , Asia , Energía Renovable , Análisis de los Mínimos CuadradosRESUMEN
BACKGROUND: Coxsackievirus A10 (CV-A10) is one of the etiological agents associated with hand, foot and mouth disease (HFMD) and usually causes mild cases. During 2009-2014, no severe cases caused by CV-A10 was reported in Xiamen, China, however, an increase in cases was seen in 2015. OBJECTIVES: We aimed to perform a retrospective molecular epidemiological analysis of HFMD associated with CV-A10 infections in Xiamen. STUDY DESIGN: CV-A10 VP1 (n=41) capsid and full-length or near full-length genomes (n=14) were sequenced. Phylogenetic trees were constructed based on these sequences and other reference sequences and nucleotide and amino acid changes were characterized. RESULTS: From 2009-2014, no laboratory-confirmed CV-A10 infections associated with severe cases were identified, however, in 2015, 39% (7/18) of severe HFMD cases were CV-A10 infections. Sequence analysis of severe and non-severe CV-A10 HFMD cases determined that severe cases predominantly clustered with an emerging clade E lineage A strain which contained 4 nucleotide changes in 5' UTR and 5 amino acid substitutions in structural and non-structural proteins. CONCLUSIONS: The results indicate CV-A10 infection may be emerging as a new and major cause of severe HFMD and CV-A10 surveillance should be increased and considered in HFMD prevention and control strategies.
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Enterovirus Humano A/genética , Enfermedad de Boca, Mano y Pie/virología , Proteínas de la Cápside/genética , China/epidemiología , Genotipo , Enfermedad de Boca, Mano y Pie/epidemiología , Enfermedad de Boca, Mano y Pie/patología , Humanos , FilogeniaRESUMEN
The nucleotide-binding site (NBS)-leucine-rich repeat (LRR) gene family is a class of R genes in plants. NBS genes play a very important role in disease defence. To further study the variation and homology of mango NBS-LRR genes, 16 resistance gene analogues (RGAs) (GenBank accession number HM446507-22) were isolated from the polymerase chain reaction fragments and sequenced by using two degenerate primer sets. The total nucleotide diversity index Pi was 0.362, and 236 variation sites were found among 16 RGAs. The degree of homology between the RGAs varied from 44.4% to 98.5%. Sixteen RGAs could be translated into amino sequences. The high level of this homology in the protein sequences of the P-loop and kinase-2 of the NBS domain between the RGAs isolated in this study and previously characterized R genes indicated that these cloned sequences belonged to the NBS-LRR gene family. Moreover, these 16 RGAs could be classified into the non-TIR-NBS-LRR gene family because only tryptophan (W) could be claimed as the final residual of the kinase-2 domain of all RGAs isolated here. From our results, we concluded that our mango NBS-LRR genes possessed a high level of variation from the mango genome, which may allow mango to recognize many different pathogenic virulence factors.
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Noroviruses (NoV) have been recognized as an important pathogen associated with acute gastroenteritis worldwide during the past three decades. In the spring of 2012, a series of foodborne outbreaks in tourist groups were reported to Xiamen Center for Disease Control and Prevention, Xiamen, Fujian province, China. Among a total of 268 tourists in 7 groups, the prevalence rate of acute gastroenteritis was 16.0% (43/268). Twenty-three feces or anal swabs were collected for laboratory tests of causative agents, no bacterial pathogen was identified, while 22 of them were positive for NoV RNA. In addition, thirteen NoV fragments were recovered from positive specimens and sequenced, belonging to five genotypes such as GI.3, GI.4, GII.4, GII.6, and GII.14, respectively. However, NoV fragments obtained from locally infected patients showed distinct genotypes. Therefore, epidemiological investigation and laboratory analyses demonstrated that the serial foodborne NoV outbreaks in tourists were co-infection of multiple genotypes induced acute gastroenteritis linked to a restaurant.
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Infecciones por Caliciviridae/epidemiología , Brotes de Enfermedades/estadística & datos numéricos , Enfermedades Transmitidas por los Alimentos/epidemiología , Enfermedades Transmitidas por los Alimentos/virología , Gastroenteritis/virología , Norovirus/genética , China/epidemiología , Análisis por Conglomerados , Biología Computacional , Cartilla de ADN/genética , Heces/virología , Genotipo , Humanos , Norovirus/patogenicidad , Filogenia , Prevalencia , Análisis de Secuencia de ADNRESUMEN
OBJECTIVE: To identify the etiology of an aseptic encephalitis outbreak (ten cases) in a hospital of Xiamen city from 11 to 17 May, 2011. METHODS: A total of ten patients' throat swabs, anal swabs and cerebrospinal fluid were collected and detected by RT-PCR for pan-enterovirus. The samples containing detectable pan-enterovirus were tested by PCR with genotype-specific general primers located in VP1 region of enterovirus genotype A, B and C (HEV-A, B and C). The PCR products of VP1 segment were purified and sequenced, and phylogenetic analysis was performed. Meanwhile, the pathogens in those samples were isolated in Vero cell culture. Homologous analysis of VP1 sequences were carried out for the cultured virus samples and the original clinical samples to identify the outbreak etiology. RESULTS: Among the ten cases, seven cases were positive for pan-enterovirus nucleic acid. When tested by genotype-specific PCR, the throat and anal swab samples from those 7 patients were positive with HEV-B VP1 primers. Meanwhile, the HEV-B VP1 segments were sequenced and phylogenetic analyzed, which indicated the seven cases were all infected by enterovirus Echo 30. The sequences from those samples had homology of 95.3% - 97.1% with the epidemic strains in Zhejiang, 2004. Out of the seven cases, the sequences of XM2, XM3, XM4, XM8 throat swab samples and XM3, XM6 throat samples showed 99.4% - 100.0% homology which were different from the sequence of XM1, and the homology was 92.8% - 93.4%. Furthermore, the viruses were isolated using Vero cells from XM1, XM2, XM3, XM4 and XM8 throat swab samples, and the VP1 sequence showed more than 99.9% homology with the original specimens. CONCLUSION: The local outbreak of aseptic encephalitis was caused by Echo 30 of enterovirus genotype B, and the epidemic strains may have different genetic background.
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Infección Hospitalaria/epidemiología , Brotes de Enfermedades , Encefalitis/epidemiología , Encefalitis/virología , Preescolar , China/epidemiología , Infección Hospitalaria/virología , Enterovirus/genética , Enterovirus Humano B/genética , Femenino , Genotipo , Humanos , Masculino , Datos de Secuencia MolecularRESUMEN
The antioxidant activities of the petroleum ether, ethyl acetate, n-BuOH and water extract fractions from Dracaena cambodiana Pierre ex Gagnep were evaluated in this study. The ethyl acetate fraction contained the highest amount of total phenolics and total flavonoids, and showed the greatest DPPHË, ABTS+ and Superoxide anion radical-scavenging capacities. The DPPHË, ABTS+ and Superoxide anion radical-scavenging capacities of nine compounds isolated from the ethyl acetate fraction were also evaluated. The results indicated that these compounds contributed to the antioxidant activity of D. cambodiana. Therefore, D. cambodiana and these compounds might be used as natural antioxidants.
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Dracaena/química , Depuradores de Radicales Libres/química , Depuradores de Radicales Libres/aislamiento & purificación , Fenoles/química , Fenoles/aislamiento & purificación , Flavonoides/química , Flavonoides/aislamiento & purificaciónRESUMEN
Chitosan has the potential for DNA complexation and is useful as a non-viral vector for gene delivery. Highly purified low molecular weight chitosan (LMWC) was prepared. Lactobionic acid (LA) bearing galactose group was coupled with LMWC for liver-specificity. A series of galactosylated-LMWC (gal-LMWC) samples covering a range of galactose group contents were prepared. The chitosan/DNA complexes were obtained using a complex coacervation process. Gal-LMWCs were used to transfer pSV-beta-galactosidase reporter gene into human hepatocellular carcinoma cell (HepG2), L-02, SMMC-7721, and human cervix adenocarcinoma cell line (HeLa) cell lines in vitro. Transfection efficiency of gal-LMWCs was evaluated by beta-galactosidase assay and compared with those of lipofectin, calcium phosphate (CaP), high molecular weigh chitosan (HMWC) and LMWC. Gal-LMWC/DNA complex shows a very efficient cell selective transfection to hepatocyte. The transfection efficiency of gal-LMWCs increased with the improvement of the galactosylation degree. Cytotoxicity of gal-LMWC was determined by 3-(4,5-dimethylthiazd-2-yl)-2,5-diphenyltentrazolium bromide (MTT) assay and the results show that the modified chitosan has relatively low cytotoxicity, giving the evidence that the modified chitosan vector has the potential to be used as a safe gene-delivery system.