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1.
J Environ Manage ; 369: 122271, 2024 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-39236618

RESUMO

Despite remarkable success in attracting foreign direct investment (FDI) to achieve maximum economic growth, the Next-11 emerging economies grappling with an undesirable situation of environmental degradation have become a hot topic at COP28. Researchers have long focused on this connection, emphasizing the urgent need for international and national environmentalists to promote sustainable development (SD) in these rapidly growing economies under the United Nations (UN) Framework Convention on Climate Change action plans. As a result, this study examines the role of FDI in the N-11 emerging economies, focusing on energy usage and technological innovation within the theoretical framework of the Halo-Haven hypothesis, covering the period from 1990 to 2022. We utilize ARDL, FMOLS, and DOLS techniques to analyze both short-term dynamics and long-term equilibrium relationships, effectively managing heterogeneity, time dynamics, and cross-sectional dependence issues to produce comprehensive results. The long-term analysis supports the haven hypothesis, demonstrating an affirmative relationship between FDI, economic growth, and carbon emissions, whereas energy usage is negatively associated with carbon emissions. Furthermore, the D-H test established a reciprocal causal relationship between variables such as FDI, economic growth, trade openness, and environmental pollution. However, we found a one-way causal correspondence in the usage of green energy, the technological innovation index, and carbon emissions. Given the mixed findings, policymakers should focus on attracting FDI to the green energy sector while reinforcing regulations and implementing stringent oversight for FDI in energy-intensive industries. This approach will ensure that such investments adhere to high environmental standards, thereby benefiting future generations.

2.
J Biol Chem ; 294(28): 10789-10806, 2019 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-31088911

RESUMO

Human IgG2 antibody displays distinct therapeutically-useful properties compared with the IgG1, IgG3, and IgG4 antibody subclasses. IgG2 is the second most abundant IgG subclass, being able to bind human FcγRII/FcγRIII but not to FcγRI or complement C1q. Structural information on IgG2 is limited by the absence of a full-length crystal structure for this. To this end, we determined the solution structure of human myeloma IgG2 by atomistic X-ray and neutron-scattering modeling. Analytical ultracentrifugation disclosed that IgG2 is monomeric with a sedimentation coefficient (s20, w0) of 7.2 S. IgG2 dimer formation was ≤5% and independent of the buffer conditions. Small-angle X-ray scattering in a range of NaCl concentrations and in light and heavy water revealed that the X-ray radius of gyration (Rg ) is 5.2-5.4 nm, after allowing for radiation damage at higher concentrations, and that the neutron Rg value of 5.0 nm remained unchanged in all conditions. The X-ray and neutron distance distribution curves (P(r)) revealed two peaks, M1 and M2, that were unchanged in different buffers. The creation of >123,000 physically-realistic atomistic models by Monte Carlo simulations for joint X-ray and neutron-scattering curve fits, constrained by the requirement of correct disulfide bridges in the hinge, resulted in the determination of symmetric Y-shaped IgG2 structures. These molecular structures were distinct from those for asymmetric IgG1 and asymmetric and symmetric IgG4 and were attributable to the four hinge disulfides. Our IgG2 structures rationalize the existence of the human IgG1, IgG2, and IgG4 subclasses and explain the receptor-binding functions of IgG2.


Assuntos
Imunoglobulina G/química , Imunoglobulina G/ultraestrutura , Proteínas de Transporte/química , Proteínas de Transporte/ultraestrutura , Humanos , Fragmentos Fab das Imunoglobulinas/química , Fragmentos Fc das Imunoglobulinas/química , Imunoglobulina G/metabolismo , Modelos Moleculares , Estrutura Molecular , Difração de Nêutrons/métodos , Nêutrons , Ligação Proteica/fisiologia , Conformação Proteica , Espalhamento a Baixo Ângulo , Ultracentrifugação/métodos , Difração de Raios X/métodos , Raios X
3.
J Am Chem Soc ; 137(18): 5863-6, 2015 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-25910509

RESUMO

Stoichiometric control of Ru, Ag, and tetrazolyl ligands resulted in the formation of different heterometallic Ru-Ag supramolecular architectures. Although the reaction of Ru and 5-(2-hydroxyphenyl)-1H-tetrazolyl (LH2) in a molar ratio of 2:1 or 6:4 resulted in the formation of dimeric or hexameric Ru complexes, Ag metal ions caused the Ru complexes to form three-dimensional cylindrical Ru6Ag6L6 and double-cone-shaped Ru6Ag8L6 complexes by occupying vacant coordination sites.

4.
Environ Sci Pollut Res Int ; 29(16): 23001-23014, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34797543

RESUMO

This study explores the impact of fiscal policy on environmental pollution, employing the vector autoregressive (VAR) model on annual data from 1976 to 2018 in Pakistan. We estimate the effect of total expenditure, total revenue, education expenditures, health expenditures, and other dynamic determinants such as gross domestic product (GDP), private investment, market rate, and crude oil price on carbon dioxide (CO2) emissions in particular. Further, this study creates impulse response functions to check the fiscal shocks, coordinating with five scenarios of public expenditures, segregated into government revenue, and education and health expenditures. The outcomes indicate that government spending in the public sectors (education and health) had a diminishing effect on CO2 emissions, whereas government revenue that was collected from taxes improved economic growth but at a cost of environmental pollution. In Pakistan, a fiscal policy scenario has been implemented that increases government expenditures to alleviate the effects of CO2 emissions. Therefore, policymakers should provide the right direction for the feasible distribution of resources in every public sector through a powerful structure, which will ultimately reduce the overall level of environmental deficit.


Assuntos
Política Fiscal , Dióxido de Carbono/análise , Desenvolvimento Econômico , Poluição Ambiental/análise , Produto Interno Bruto , Gastos em Saúde , Paquistão
5.
Sci Rep ; 10(1): 12431, 2020 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-32709940

RESUMO

The metal-free nitrogen-doped graphitic-carbon@graphene (Ng-C@G) is prepared from a composite of polyaniline and graphene by a facile polymerization following by pyrolysis for electrochemical oxygen reduction reaction (ORR). Pyrolysis creates a sponge-like with ant-cave-architecture in the polyaniline derived nitrogenous graphitic-carbon on graphene. The nitrogenous carbon is highly graphitized and most of the nitrogen atoms are in graphitic and pyridinic forms with less oxygenated is found when pyrolyzed at 800 °C. The electrocatalytic activity of Ng-C@G-800 is even better than the benchmarked Pt/C catalyst resulting in the higher half-wave potential (8 mV) and limiting current density (0.74 mA cm-2) for ORR in alkaline medium. Higher catalytic performance is originated from the special porous structure at microscale level and the abundant graphitic- and pyridinic-N active sites at the nanoscale level on carbon-graphene matrix which are beneficial to the high O2-mass transportation to those accessible sites. Also, it possesses a higher cycle stability resulting in the negligible potential shift and slight oxidation of pyridinic-N with better tolerance to the methanol.

6.
Sci Rep ; 9(1): 11051, 2019 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-31363157

RESUMO

Transitional metal-nitrogen-carbon system is a promising candidate to replace the Pt-based electrocatalyst due to its superior activity, durability and cost effectiveness. In this study, we have designed a simple strategy to fabricate carbon nanotubes-supported binary-nitrogen-carbon catalyst via wet-chemical method. Palladium and transitional metals (M, i.e. manganese cobalt and copper) nanoparticles are anchored through four-nitrogen system onto carbon nanotubes (denoted as PdM-N4/CNTs). This material has been used as bifunctional electrocatalyst for electrochemical ethanol oxidation reaction and hydrogen evolution reaction for the first time. The N4-linked nanoparticles onto carbon nanotubes plays a crucial role in intrinsic catalytic activity for both reactions in 1 M KOH electrolyte. Among three PdM-N4/CNTs catalysts, the PdMn-N4/CNTs catalyst exhibits higher catalytic activity in terms of current density, mass activity and stability compared to the benchmark Pt/C. The robust electrocatalysis are inherited from the better attachment of PdMn through N4-system onto carbon nanotubes, comparatively smaller particles formation with better dispersion and higher electrical conductivity.

7.
ACS Appl Mater Interfaces ; 9(45): 39303-39311, 2017 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-29068660

RESUMO

Tunable palladium nanonetwork (PdNN) has been developed for catalyzing ethanol oxidation reaction (EOR) and hydrogen evolution reaction (HER) in alkaline electrolyte. 3D PdNN is regarded as a dual active electrocatalyst for both EOR and HER for energy conversion application. The PdNN has been synthesized by the simple chemical route with the assistance of zinc precursor and a surfactant (i.e., cetyltrimethylammonium bromide, CTAB). The thickness of the network can be tuned by simply adjusting the concentration of CTAB. Both EOR and HER have been performed in an alkaline electrolyte, and characterized by different voltammetric methods. The 3D PdNN has shown 2.2-fold higher electrochemical surface area than the commercially available Pt/C including other tested catalysts with minimal Pd loading. As a result, it provides a higher density of EOR and HER active sites and facilitated the electron transport. For example, it shows 2.6-fold higher mass activity with significantly lower CO2 production for EOR and the similar overpotential (110 mV @ 10 mA cm-2) for HER compared to Pt/C with better reaction kinetics for both reactions. Thus, the PdNN is proved as an efficient electrocatalyst with better electrocatalytic activity and stability than state-of-the-art Pt/C for both EOR and HER because of the crystalline, monodispersed, and support-free porous nanonetwork.

8.
ACS Omega ; 2(6): 3043-3054, 2017 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-31457638

RESUMO

Amide-functionalized materials have emerged as promising nonprecious catalysts for electrochemical sensing and catalysis. The covalent immobilization of chitosan (CS) onto graphene sheet (GS) (denoted as CS-GS) has been done via higher degree of amidation reaction to develop an electrochemical sensing matrix for simultaneous determination of dopamine (DA) and uric acid (UA). The enhanced amidation between CS and GS has not been reported previously. However, electrochemical results have revealed that the CS-GS enhances the electrocatalytic performance in terms of the oxidation potential and peak current due to the higher degree of amide functionalization compared to that of CS/GS, which has a lower amidation. Differential pulse voltammetry-based studies have indicated that the CS-GS matrix works at a lower detection limit (0.14 and 0.17 µM) (S/N = 3) and over a longer linear range (1-700 and 1-800 µM), with a comparatively higher sensitivity (2.5 and 2.0 µA µM-1 cm-2), for DA and UA, respectively. In addition, the CS-GS matrix demonstrates good selectivity toward the detection of DA and UA in the presence of a 10-fold higher concentration of AA and glucose. The as-prepared three-dimensional porous CS-GS also endows selective determination toward DA and UA in various real samples.

10.
J Enzyme Inhib Med Chem ; 23(1): 136-9, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18341265

RESUMO

The crude methanolic extract and subsequent fractions of Teucrium royleanum (Labiatea) were screened for antibacterial and antifungal activities. Against tested pathogens, crude extract and subsequent fractions demonstrated moderate to excellent antibacterial activities. Highest antibacterial activity was displayed by the ethyl acetate fraction against S. typhi (100%), against E.coli (76.7%) and against P. aerugenosa (70.8%) followed by the chloroform fraction against S. typhi (85.7%). Similarly, the crude extract and its subsequent fractions showed mild to excellent activities in the antifungal bioassay with maximum antifungal activity against M. canis (87%) by the chloroform fraction followed by the ethyl acetate (71%) and n-butanol (70%) fractions.


Assuntos
Antibacterianos/farmacologia , Antifúngicos/farmacologia , Lamiaceae , Extratos Vegetais/farmacologia , Bactérias/efeitos dos fármacos , Fungos/efeitos dos fármacos , Teucrium
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