RESUMEN
Investigating the CO2 abatement potential of urban residential building from systematic perspective is essential to reach the urban carbon neutrality target. However, previous studies on building CO2 emission trend forecasting were mainly focused on the building operational phase. In this study, a new framework that includes four building stages under a system dynamic model is developed to simulate urban residential building carbon emission changes and the related reduction potentials under three scenarios in Jiangxi Province up to 2060. Results showed that the overall process carbon emission dynamic had already peaked in 2014 under the three scenarios, with a peak value of 38.52 Mt. It then fell to 9.56 Mt in 2060 under the baseline (BAU) scenario. More importantly, seven carbon abatement measures were adopted during four building activities in this study, and the total carbon reduction was not the sum of the carbon reduction potential of the individual measures. Some carbon abatement strategies displayed synergistic effects such as low-carbon electrification where the combination of electrification and clean energy power generation was the largest contributor to reduced carbon emissions during building operation as a comprehensive carbon reduction measure. By contrast, extending a building's lifetime restrained the carbon abatement potential during the demolition stage, and it inhibited the carbon emission reduction by 24.84 Mt. These results highlight the significant need for effective policy interventions for clean production and the need to improve prefabricated building proportions, promote electrification, improve energy efficiency, strengthen recycling practices, and extend building lifetimes to promote decarbonization of urban residential building system development.
Asunto(s)
Dióxido de Carbono , Reciclaje , Dióxido de Carbono/análisis , China , Carbono/análisis , PredicciónRESUMEN
OBJECTIVE: To assess the biomechanical stability of unilateral pedicle screws (UPS) plus contralateral transfacetopedicular screws (TFPS) after transforaminal lumbar interbody fusion (TLIF) with two cages. METHODS: Range of motion (ROM) testing was performed in 28 fresh-frozen human cadaveric lumbar spine motion segments. The sequential test configurations included supplemental constructs after TLIF such as UPS, UPS plus contralateral TFPS and bilateral pedicle screws (BPS). All test specimens were fixated in the normal lordotic lignment, then mounted in a three-dimensional (3-D) motion testing machine and fixed to the load frame of a six degrees of freedom spine simulator. Each of the test constructs were subjected to three load-unload cycles in each of the physiologic planes generating flexion-extension, right-left lateral bending and right-left axial rotation load-displacement curves. Statistical analysis was performed on the ROM data. Comparison of data was performed by repeated-measures analysis of variance for independent samples followed by Bonferroni analysis for multiple comparison procedures. RESULTS: The ROMs for UPS, BPS and UPS plus TFPS fixation after TLIF were significantly smaller than those of the intact spine in all modes. The ROM for UPS plus TFPS fixation was between the largest for UPS and the smallest for BPS. The differences between ROMs of UPS and UPS plus TFPS were significant for both lateral bending and rotation. There were no significant differences between BPS and UPS plus TFPS in any mode. CONCLUSION: Because the UPS construct provides the least stability, especially during lateral bending and rotation, it should be used prudently. After TLIF with two cages, UPS plus TFPS provides stability comparable to that of TLIF with BPS. It is thus an acceptable option in minimally invasive surgery.
Asunto(s)
Tornillos Óseos , Vértebras Lumbares/cirugía , Fusión Vertebral/instrumentación , Adolescente , Adulto , Fenómenos Biomecánicos/fisiología , Cadáver , Humanos , Fijadores Internos , Vértebras Lumbares/fisiopatología , Ensayo de Materiales/métodos , Procedimientos Quirúrgicos Mínimamente Invasivos/instrumentación , Procedimientos Quirúrgicos Mínimamente Invasivos/métodos , Rango del Movimiento Articular/fisiología , Rotación , Fusión Vertebral/métodos , Adulto JovenRESUMEN
OBJECTIVE: To investigate the antitumor effect of calcium phosphate cement incorporated with doxorubicin microspheres. METHODS: The absorbance at 490 nm of SaoS-2 cells cultured for 5 days in the media containing the extract of the cement incorporating doxorubicin microspheres was measured using Cell Counting Kit-8. SaoS-2 cells were adjusted to the density of 2x10(7) ml(-1) and injected into the left buttock of nude mouse in the volume of 0.2 ml. The cell suspension (0.1 ml) mixed with an equal volume of the cement extract were injected into the right buttock and on the back of the bilateral ears of nude mice. At 12 days after the cell injection, the tumor tissues were obtained and weighed to calculate the tumor inhibition rate, and the pathological samples were observed with HE staining. RESULTS: The extract of the bone cement containing doxorubicin microspheres showed inhibitory effects on the tumor growth in a dose-dependent manner. The tumor inhibition rate reached 61.0% in high-dose group. Tumor necrosis was found in high dose group, but virtually absent in low-dose group. CONCLUSIONS: CPC containing doxorubicin PLGA microspheres can inhibit tumor cell growth both in vitro and in vivo.