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[Objective] The issue of carbon emission efficiency is of great significance to the realization of the “dual carbon” goal. To reveal the impact of land resource misallocation on carbon emission efficiency, and to explore its path, it provides a scientific basis for promoting regional green and low-carbon development from the perspective of land resource allocation. [Methods] Based on the theory that land resource misallocation affects carbon emission efficiency, and using the spatial Durbin model and mediation effect model, this study examined the spatial effect of land resource misallocation on carbon emission efficiency and mechanism of 108 cities in the Yangtze River Economic Belt from 2004 to 2020. [Results] (1) The indirect effect of land resource misallocation on carbon emission efficiency is far greater than the direct effect, and the preferential allocation of land will do more harm by the negative externalities of neighboring cities. (2) For different locations and cities of different sizes, land resource misallocations and their spatial effects vary greatly. (3) Land resource misallocation has a complex mechanism for affecting carbon emission efficiency, which can reduce regional carbon emission efficiency through inhibiting innovation ability development, slowing industrial structure upgrading, and blocking new-type urbanization. [Conclusion] In order to improve regional carbon emission efficiency, the Chinese government should accelerate the market-oriented reform of land factor allocation, strengthen the concept of regional cooperation and win-win cooperation and collaborative governance capacity. Based on these results, we argued that increasing the support for technological innovation, optimizing the industrial structure, and actively and orderly promoting new-type urbanization are the effective ways to increase carbon emission efficiency in the future.

Land-use transition (LUT) refers to the change in the land-use form corresponding to the regional economic and social development. At different stages of LUT, changes in the land-use scale and structure may lead to carbon source transfer by affecting industrial transfer and carbon sinks, resulting in changes in the total carbon emission transfer (CET) from the land use in the whole region. The clarification of the relationship between LUT and CET is of great importance for the sustainable development of the regional economy and society and the realization of carbon peak and carbon neutrality. In this paper, we firstly conducted a theoretical analysis of the nonlinear relationship between LUT and CET, then took the Middle Reaches of the Yangtze River in China as an example to explore the characteristics of LUT and CET, and finally constructed a threshold regression model to verify their nonlinear relationship. The following main findings were obtained. (1) From 2000 to 2020, profound LUT had occurred in the Middle Reaches of the Yangtze River, with continuous decreases in farmland, substantial increases in construction land, and a first decrease and then increase in forest land; farmland is the main contributor to construction land and forest with a contribution rate exceeding 60%. (2) During the study period, the CET in the Middle Reaches of the Yangtze River exhibited certain regular characteristics. The phase characteristics of the carbon sink changes follow an intensification–moderation–reintensification–remoderation pattern, and those of the carbon source transfer and net carbon emissions follow an intensification–reintensification–moderation–remoderation pattern. In addition, carbon sink changes are far from enough to offset the effect of carbon source transfer. (3) The nonlinear relationship between LUT and CET was confirmed by the threshold effect at the economic development level, industrial optimization level, and technological progress level. The nonlinear relationship between the LUT and the carbon sink changes in the Middle Reaches of the Yangtze River is on the left side of the U-shaped curve and that between the LUT and the carbon source transfer or net carbon emissions is on the left side of the inverted U-shaped curve. [ABSTRACT FROM AUTHOR]

The reduction of carbon emissions from land use (CELU) is critical for China to achieve carbon neutrality, which may be greatly facilitated by carbon trading policies. Previous studies of the emission reduction effects of carbon trading policies focused mostly on the reduction of carbon source emissions, and there is a lack of research from the comprehensive perspective of carbon sources and carbon sinks. Understanding the effect of carbon trading policies on emission reduction from the perspective of CELU may help to improve the evaluation system of carbon trading policies, as well as provide important implications for the construction of China's carbon trading market in the context of global carbon neutrality. Here, based on China's current carbon-trading pilot areas, quasi-natural experiments were conducted by using the CELU data from 2005 to 2017, the synthetic control method (SCM) and the mediation effect model, aiming to empirically study the reduction effect and mechanism of carbon trading policies on CELU. The following main findings were obtained. (1) Carbon trading policies have had a significant reduction effect on the average CELU of the pilot areas by at least four million tons per year during the study period. (2) The carbon emission reduction effect of carbon trading policies has certain regional heterogeneity. (3) Carbon trading policies reduce CELU through the intermediate effect of energy structure, whose contribution rate reaches 30.433%. (4) Carbon trading policies did not achieve the Porter effect of technological progress during the study period, and technological progress has no significant intermediate effect on the reduction of CELU by carbon trading policy. Based on the above findings, the following policy implications can be proposed. Carbon trading and carbon offset should be studied from a comprehensive perspective of land use; regional heterogeneity should be considered when promoting the carbon emission trading system nationwide; and the energy structure should be optimized continuously. [ABSTRACT FROM AUTHOR]

Background: No head-to-head trial directly compares the effectiveness of vedolizumab (VDZ) and infliximab (IFX) in patients with ulcerative colitis (UC) who were naïve to biologic therapy., Objectives: We aimed to compare the clinical and endoscopic effectiveness of VDZ and IFX in biologic-naïve patients with UC in real-world settings., Design: It was a multicenter, observational, real-world cohort study conducted at five centers., Methods: Patients diagnosed with UC and treated with either IFX or VDZ as their first-line biologic therapy were retrospectively enrolled. Steroid-free remission, clinical response, clinical remission, and endoscopic healing at week 14 and week 52 were compared between the two groups after propensity score weighting., Results: A total of 199 patients (117 VDZ and 82 IFX) were included in the study. There were no significant differences in steroid-free remission (64.6% vs 56.1%, p  = 0.224), clinical response (83.4% vs 73.4%, p  = 0.086), or clinical remission (69.4% vs 60.1%, p  = 0.174) at week 14. However, VDZ showed better results in steroid-free remission (67.5% vs 44.4%, p  = 0.004), clinical response (69.7% vs 47.1%, p  = 0.005), and clinical remission (67.5% vs 44.4%, p  = 0.004) at week 52. In terms of endoscopic healing, VDZ was similar to IFX at week 14 (25.7% vs 17.4%, p  = 0.185), but VDZ had a significantly higher rate at week 52 (29.5% vs 11.8%, p  = 0.027). VDZ was found to be superior to IFX in therapeutic continuation (hazard ratio = 0.339, 95% CI: 0.187-0.614, p  < 0.001). The rate of adverse events was similar between the two groups (6.8% vs 8.5%, p  = 0.655)., Conclusion: VDZ demonstrated similar clinical and endoscopic effectiveness to IFX at week 14 in biologic-naïve patients with UC, but appeared to be superior at week 52. The safety outcomes were comparable between the groups., Competing Interests: The authors declare that there is no conflict of interest., (© The Author(s), 2024.)