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1.
Environ Sci Pollut Res Int ; 31(16): 24619-24633, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38446295

RESUMO

Much research demonstrates the positive effects of financial inclusion and digital finance on expansion. Supply chains that can be relied upon are essential to national productivity and economic development. This study uses panel data from 2007 to 2022 covering 27 provinces in China to study the results of widespread access to digital financial services and supply chain management on regional economic growth using the instrumental variable approach (fixed effect model). In contrast to earlier research, this study employs an alternative measure of access to digital financial services utilization and digitalization. The data demonstrates that digital financial inclusion and supply chain management have a major impact on the development of the provincial economies in China. Based on the results of this research, we suggest increasing digital financial inclusion and bolstering human capital development to stimulate economic expansion. This essay makes a theoretical advancement in studying digital technology's widespread adoption of financial services by providing a comprehensive critical review and a fresh angle on the nuts and bolts of digital money and universal banking. Boosting institutional quality and governance are two more paths that authorities can take to stimulate economic expansion in the China area, and the results show how important these measures are for achieving this goal.


Assuntos
Desenvolvimento Econômico , Instalações de Saúde , Humanos , China
2.
Chemosphere ; 291(Pt 1): 132723, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34736744

RESUMO

Biotrickling filter (BTF) is a widely applied bioreactor for odour abatement in sewer networks. The trickling strategy is vital for maintaining a sound operation of BTF. This study employed a lab-scale BTF packed with granular activated carbon at a short empty bed residence time of 6 s and pH 1-2 to evaluate different trickling strategies, i.e., continuous trickling (different velocities) and intermittent trickling (different trickling intervals), in terms of the removal of hydrogen sulfide (H2S), bed pressure drop, H2S oxidation products and microbial community. The H2S removal performance decreased with the trickling velocity (∼3.6 m/h) in BTF. In addition, three intermittent trickling strategies, i.e., 10-min trickling per 24 h, 8 h, and 2 h, were investigated. The H2S elimination capacity deteriorated after about 2 weeks under both 10-min trickling per 24 h and 8 h. For both intermittent (10-min trickling per 2 h) and continuous trickling, the BTF exhibited nearly 100 % H2S removal for inlet H2S concentrations<100 ppmv, but intermittent BTF showed better removal performance than continuous trickling when inlet H2S increased to 120-190 ppmv. Furthermore, the bed pressure drops were 333 and 3888 Pa/m for non-trickling and trickling periods, respectively, which makes intermittent BTF save 83 % energy consumption of the blower compared with continuous tirckling. However, intermittent BTF exhibited transient H2S breakthrough (<1 ppmv) during trickling periods. Moreover, elemental sulfur and sulfate were major products of H2S oxidation and Acidithiobacillus was the dominant genus in both intermittent and continuous trickling BTF. A mathematical model was calibrated for the intermittent BTF and a sensitivity analysis was performed on the model. It shows mass transfer parameters determine the H2S removal. Overall, intermittent trickling strategy is promising for improving odour abatement performance and reducing the operating cost of the BTF.


Assuntos
Sulfeto de Hidrogênio , Microbiota , Biodegradação Ambiental , Reatores Biológicos , Filtração , Enxofre
3.
Front Vet Sci ; 8: 661773, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34235199

RESUMO

In sheep industry, hypothermia caused by insufficient brown adipose tissue (BAT) deposits is one of the major causes of lamb deaths. Enhancing the formation and function of BAT in neonatal lamb increases thermogenesis and hence reduces economic losses. The aim of the present study was to explore the effect and mechanism of melatonin on sheep brown adipocyte formation and function. Sheep brown adipocyte precursor cells (SBACs) isolated from perirenal BAT were treated with melatonin (1 and 10 nM). The SBACs subjected to melatonin exhibited a decreased proliferation ability, accompanied by down-regulated proliferating cell nuclear antigen, cyclin D1, and CDK4 protein contents in a melatonin dose-dependent manner. Melatonin promoted brown adipocyte formation and induced the expression of brown adipogenic markers, including uncoupling protein 1 and PR domain-containing 16 during differentiation of SBAC. Moreover, the AMP-activated protein kinase α1 (AMPKα1) activity was positively correlated with brown adipocyte formation potential. Importantly, melatonin effectively activated AMPKα1. Furthermore, promotional effects of melatonin were abolished by AMPKα1 knockout, suggesting the involvement of AMPKα1 in this process. Collectively, these results suggested that melatonin enhanced brown adipocyte formation in SBACs in vitro through activation of AMPKα1.

4.
Sci Total Environ ; 791: 148270, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34119799

RESUMO

Bio-concrete is known for its self-healing capacity although the corrosion resistance was not investigated previously. This study presents an innovative bio-concrete by mixing anaerobic granular sludge into concrete to mitigate sewer corrosion. The control concrete and bio-concrete (with granular sludge at 1% and 2% of the cement weight) were partially submerged in a corrosion chamber for 6 months, simulating the tidal-region corrosion in sewers. The corrosion rates of 1% and 2% bio-concrete were about 17.2% and 42.8% less than that of the control concrete, together with 14.6% and 35.0% less sulfide uptake rates, 15.3% and 55.6% less sulfate concentrations, and higher surface pH (up to 1.8 units). Gypsum and ettringite were major corrosion products but in smaller sizes on bio-concrete than that of control concrete. The total relative abundance of corrosion-causing microorganisms, i.e. sulfide-oxidizing bacteria, was significantly reduced on bio-concrete, while more sulfate-reducing bacteria (SRB) was detected. The corrosion-resistance of bio-concrete was mainly attributed to activities of SRB derived from the granular sludge, which supported the sulfur cycle between the aerobic and anaerobic corrosion sub-layers. This significantly reduced the net production of biogenic sulfuric acid and thus corrosion. The results suggested that the novel granular sludge-based bio-concrete provides a highly potential solution to reduce sewer corrosion.


Assuntos
Esgotos , Enxofre , Materiais de Construção , Corrosão , Sulfetos
5.
Chemosphere ; 277: 130333, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33780683

RESUMO

Volatile sulfur compounds (VSCs) were identified as the dominant priority odorants emitted from sewers, including hydrogen sulfide (H2S), methyl mercaptan (MM), dimethyl disulfide (DMDS) and dimethyl sulfide (DMS). Biotrickling filter (BTF) is a widely-applied technology for odour abatement in sewers because of its relatively low operating cost and efficient H2S removal. The authors review the mechanisms and performance of BTF for the removal of these four VSCs, and discuss the key influencing factors including of empty bed residence time (EBRT), pH, temperature, nutrients, water content, trickling operation and packing materials. Besides, measures to improve the VSCs removal in BTF are proposed in the context of key influencing factors. Finally, the review assesses the new challenges of BTF for sewer emissions treatment, namely with respect to the performance of BTF for greenhouse gases (GHG) treatment.


Assuntos
Sulfeto de Hidrogênio , Compostos de Enxofre , Reatores Biológicos , Filtração , Odorantes
6.
Water Res ; 182: 115961, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32622125

RESUMO

Concrete corrosion, as a major issue in sewer management, has attracted considerable research. In comparison, the corrosion of reinforcing steel bar (rebar) is not well understood. Particularly, fundamental knowledge of rebar corrosion and its interactions with concrete corrosion/cracking is largely lacking. This study investigated rebar corrosion and concrete degradation using reinforced concrete coupons exposed in a pilot sewer system. The physical-chemical corrosion characteristics were investigated in local regions; the nature of rebar rusts was analyzed using the advanced mineral analytical techniques, including Scanning Electron Microscope (SEM), Energy Dispersive X-ray Spectroscopy (EDS) and X-ray Diffraction (XRD); further, the interactions between rebar corrosion and concrete corrosion/cracking were elucidated by characterizing the microstructure and element distribution in interfacial areas using Mineral Liberation Analysis (MLA). The rebar corrosion products were found to be iron oxides, oxyhydroxides, chlorides, sulfides and sulfates. The predominant rebar corrosion reactions varied with exposure time and the development of concrete corrosion. When concrete corrosion reached rebar surface, the cracking of the concrete cover was influenced by multiple effects, including the macro-cracking induced by the corrosion products expansion, and the micro-cracking accelerated by the dissolution, diffusion and deposition of Fe derived from rebar rusts at the concrete corrosion front. A conceptual model elucidating rebar corrosion and the complex interactions between rebar corrosion and concrete degradation is proposed to support the development of corrosion prevention and refurbishment strategies for reinforced concrete sewers.


Assuntos
Esgotos , Sulfetos , Corrosão , Modelos Teóricos , Aço
7.
Org Lett ; 22(2): 648-652, 2020 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-31887060

RESUMO

A novel Brønsted acid-catalyzed reaction of alkynyl thioethers with o-hydroxybenzyl alcohols via an unexpected formal [4 + 2] annulation has been developed. This metal-free protocol leads to the facile and practical synthesis of valuable polysubstituted 2H-chromenes in mostly good to excellent yields under mild reaction conditions and features a wide substrate scope and excellent functional group tolerance.

8.
Angew Chem Int Ed Engl ; 58(28): 9632-9639, 2019 07 08.
Artigo em Inglês | MEDLINE | ID: mdl-31095848

RESUMO

Catalytic cycloisomerization-initiated cascade cyclizations of terminal alkynes have received tremendous interest, and been widely used in the facile synthesis of a diverse array of valuable complex heterocycles. However, these tandem reactions have been mostly limited to noble-metal catalysis, and are initiated by an exo-cyclization pathway. Reported herein is an unprecedented copper-catalyzed endo-cyclization-initiated tandem reaction of indolyl homopropargyl amides, where copper catalyzes both the hydroamination and Friedel-Crafts alkylation process. This method allows the practical and atom-economical synthesis of valuable bridged aza-[n.2.1] skeletons (n=3-6) with wide substrate scope, and excellent diastereoselectivity and enantioselectivity by a chirality-transfer strategy. Moreover, the mechanistic rationale for this novel cascade cyclization is also strongly supported by control experiments, and is distinctively different from the related gold catalysis.

9.
Chem Sci ; 10(10): 3123-3129, 2019 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-30996895

RESUMO

Alkene carbooxygenation has attracted considerable attention over the past few decades as this approach provides an efficient access to various oxygen-containing molecules, especially the valuable O-heterocycles. However, examples of catalytic alkene carbooxygenation via a direct C-O cleavage are quite scarce, and the C-O cleavage in these cases is invariably initiated by transition metal-catalyzed oxidative addition. We report here a novel Brønsted acid-catalyzed intramolecular alkoxylation-initiated tandem sequence, which represents the first metal-free intramolecular alkoxylation/Claisen rearrangement. Significantly, an unprecedented Brønsted acid-catalyzed intramolecular alkene insertion into the C-O bond via a carbocation pathway was discovered. This method allows the stereocontrolled synthesis of valuable indole-fused bridged [4.2.1] lactones, providing ready access to biologically relevant scaffolds in a single synthetic step from an acyclic precursor. Moreover, such an asymmetric cascade cyclization has also been realized by employing a traceless chiral directing group. Control experiments favor the feasibility of a carbocation pathway for the process. In addition, biological tests showed that some of these newly synthesized indole-fused lactones exhibited their bioactivity as antitumor agents against different breast cancer cells, melanoma cells, and esophageal cancer cells.

10.
Surg Oncol ; 26(3): 236-241, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28807242

RESUMO

BACKGROUND AND OBJECTIVES: Combination of transcatheter arterial chemoembolization (TACE) and radiofrequency ablation (RFA) has become an effective alternative therapy for hepatocellular carcinoma (HCC). In clinical practice, the choice of time interval between TACE and RFA is a key point for curative effect, but optimal time interval is uncertain in guidelines. We aim to explore the optimal time interval for HCC patients of Child-Pugh classification A or B. METHODS: Two hundred and thirty-three HCC patients of Child A or B who had undergone TACE and RFA were enrolled and divided into seven groups according to different time intervals (1-7weeks). Tumor damage, liver function, complications and survival time of patients after treatment were analyzed. RESULTS: Complete remission rate and total effective rate decreased in groups with the prolonged time interval (p < 0.05). Average Child-Pugh score of patients in first three groups significantly increased one month after combination treatment (p < 0.01). While that not happened in other groups. Complications occurred in 16.7% patients, similarly occurred in groups (p > 0.1). Median survival time in groups four and five were 42 months, longer than other groups (p < 0.01). CONCLUSION: A period of 3-5 weeks is the optimal time interval between TACE and RFA for HCC patients of Child-Pugh classification A or B.


Assuntos
Carcinoma Hepatocelular/terapia , Ablação por Cateter/métodos , Quimioembolização Terapêutica/métodos , Neoplasias Hepáticas/terapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Análise de Variância , Carcinoma Hepatocelular/mortalidade , Ablação por Cateter/efeitos adversos , Quimioembolização Terapêutica/efeitos adversos , Terapia Combinada , Feminino , Humanos , Estimativa de Kaplan-Meier , Neoplasias Hepáticas/mortalidade , Masculino , Pessoa de Meia-Idade , Fatores de Tempo , Resultado do Tratamento
11.
J Nanosci Nanotechnol ; 10(11): 7501-5, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21137969

RESUMO

In this paper, the load dependence on the interfacial friction between a cubic silicon tip and diamond substrate was investigated using molecular dynamics simulations. With the increase of the applied load, the sliding process experiences the states of superlubricity, single slip instability, double slip instability and plastic stage. The transitions from one state to the next one occur at the contact pressure 5.3 GPa, 8.0 GPa and 10.8 GPa, sequentially. In the superlubricity state, both friction and dissipated energy approach zero, independent of the load. However, in the single slip state the friction has a linear relationship with load, while the double slip mode induces decreased frictional force and lower damping. The coupling of the structure and forces in the plastic regime leads to the reduction of friction. These behaviors show good agreement with the recent experimental observations and theoretical predictions.

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