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1.
Sci Adv ; 9(4): eadf1141, 2023 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-36696510

RESUMO

Materials with programmable conductivity and stiffness offer new design opportunities for next-generation engineered systems in soft robotics and electronic devices. However, existing approaches fail to harness variable electrical and mechanical properties synergistically and lack the ability to self-respond to environmental changes. We report an electro-mechano responsive Field's metal hybrid elastomer exhibiting variable and tunable conductivity, strain sensitivity, and stiffness. By synergistically harnessing these properties, we demonstrate two applications with over an order of magnitude performance improvement compared to state-of-the-art, including a self-triggered multiaxis compliance compensator for robotic manipulators, and a resettable, highly compact, and fast current-limiting fuse with an adjustable fusing current. We envisage that the extraordinary electromechanical properties of our hybrid elastomer will bring substantial advancements in resilient robotic systems, intelligent instruments, and flexible electronics.

2.
Environ Pollut ; 320: 121020, 2023 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-36632970

RESUMO

Metabolomic and gut microbial responses of soil fauna to environmentally relevant concentrations of microplastics indicate the potential molecular toxicity of microplastics; however, limited data exist on these responses. In this study, earthworms (Eisenia fetida) were exposed to spherical (25-30 µm diameter) polystyrene microplastic-contaminated soil (0.02%, w:w) for 14 days. Changes in weight, survival rate, intestinal microbiota and metabolic responses of the earthworms were assessed. The results showed that polystyrene microplastics did not influence the weight, survival rate, or biodiversity of the gut microbiota, but significantly decreased the relative abundance of Bacteroidetes at the phylum level. Moreover, polystyrene microplastics disturbed the osmoregulatory metabolism of earthworms, as indicated by the significantly decreased betaine, myo-inositol and lactate, and increased 2-hexyl-5-ethyl-furan-3-sulfonic acid at the metabolic level. This study provides important insights into the molecular toxicity of environmentally relevant concentrations of polystyrene microplastics on soil fauna.

3.
Mol Ther Oncolytics ; 28: 88-103, 2023 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-36699616

RESUMO

Some long non-coding RNAs (lncRNAs) have been documented to be involved in cancer progression and anticancer drug resistance in hepatocellular carcinoma (HCC). Thus, approaches designed to target these genes may facilitate the development of promising strategies for treating HCC. Previously, we showed that lncRNA BBOX1-AS1 was highly expressed and played an oncogenic role in HCC. However, the potential functions and mechanisms through which BBOX1-AS1 regulates HCC progression and drug resistance remain unclear. This study revealed that BBOX1-AS1 could promote tumor progression, autophagy, and drug resistance by upregulating PHF8 in HCC cells. Mechanistically, BBOX1-AS1 enhanced the stability of PHF8 mRNA by targeting the PHF8 inhibitor miR-361-3p to regulate tumor progression and autophagy in HCC. The functional rescue experiments showed that PHF8 acted as a key factor in regulating the biological effects induced by BBOX1-AS1 and miR-361-3p in HCC, indicating that BBOX1-AS1 promotes tumor progression and sorafenib resistance by regulating miR-361-3p/PHF8. Finally, mouse tumor models and patient-derived organoid models were established to further confirm these findings. Taken together, the results demonstrate that BBOX1-AS1 promotes HCC progression and sorafenib resistance via the miR-361-3p/PHF8 axis.

4.
Foods ; 12(2)2023 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-36673489

RESUMO

This paper investigated the effects of different particle sizes and addition levels of purple sweet potato flour (PSPF) on the rheological properties and moisture states of wheat dough. There was deterioration in the pasting and mixing properties of the dough, due to the addition of PSPF (0~20% substitution), which was reduced by decreasing the particle size of the PSPF (260~59 µm). Dynamic rheology results showed that PSPF enhanced the elasticity of the dough, providing it solid-like processability. PSPF promoted the binding of gluten proteins and starch in the dough, resulting in a denser microstructure. Differential scanning calorimetry and low-field nuclear magnetic resonance showed that PSPF converted immobilized water and freezable water to bound water and non-freezable water in the dough, making the dough more stable, and that the reduction in PSPF particle size facilitated these processes. Our results provide evidence for the great application potential of purple sweet potatoes for use in flour-based products.

5.
Polymers (Basel) ; 15(2)2023 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-36679146

RESUMO

Desertification, one of the world's most pressing serious environmental problems, poses a serious threat to human survival as well as to social, economic, and political development. Nevertheless, the development of environmentally friendly sand-fixing materials is still a tremendous challenge for preventing desertification. This study developed a bio-based attapulgite copolymer (BAC) by grafting copolymerization of attapulgite, starch, sulfomethyl lignin, and biological mycelia. Water retention, anti-water erosion, and anti-wind erosion tests were conducted to assess the application performance of the BAC. Scanning electron microscopy (SEM) was then employed to determine the morphology of the attapulgite and attapulgite graft copolymer sand-fixing material (CSF). The intermolecular interactions in CSF were revealed using Fourier transform infrared spectrum (FT-IR). The role of sand-fixing materials on soil physicochemical properties and seed germination was then discussed based on the germination rate experiments, and 16S rDNA sequencing technology was used to analyze the differences in microbial communities in each sample group. The results demonstrated that the BAC not only has superior application properties and significantly increased seed germination (95%), but also promotes soil development by regulating the structure of the soil microbial community. This work provides novel insights into the design of sand-fixing material for preventing desertification while improving soil fertility.

6.
Cell Signal ; : 110612, 2023 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-36709823

RESUMO

Previously, we found that the 5-HT2A receptor plays a key role in cell injury. However, the mechanism by which the 5-HT2A receptor mediates intracellular processes remains unclear. In this study, we aimed to clarify this intracellular process in hepatocyte LO2 cells and evaluate its role in CCl4-induced hepatotoxicity in mice. In vitro, both the agonist and overexpression of 5-HT2A receptor could promote 5-HT degradation by upregulating the expression of 5-HT synthases and monoamine oxidase-A (MAO-A) to cause overproduction of ROS in mitochondria. We refer to this as the activation of the 5-HT degradation system (5DS) axis, which leads to the phosphorylation of JNK, p38 MAPK, STAT3, and NF-κB; upregulation of Bax, cleaved-caspase3, and cleaved-caspase9; and downregulation of Bcl-2, followed by apoptosis and oversecretion of TNF-α and IL-1ß in cells. This phenomenon could be markedly blocked by the 5-HT2A receptor antagonist, MAO-A inhibitor, or gene-silencing MAO-A. Through protein kinases C epsilon (PKCε) agonist treatment and gene silencing of the PKCε and 5-HT2A receptor, we demonstrated that the 5-HT2A receptor controls 5-HT synthases and MAO-A expression via the PKCε pathway in cells. Unexpectedly, we discovered that PKCε-mediated phosphorylation of the AKT/mTOR pathway is also a consequence of the activation of the 5DS axis. Furthermore, we confirmed that the inhibition of the 5DS axis using the 5-HT2A receptor antagonist could prevent hepatotoxicity induced by CCl4 both in vitro and in vivo, inhibiting the aforementioned signaling cascades, inflammation, and apoptosis, and that the 5DS activation area overlapped the necrotic area of mouse liver. Taken together, we revealed a 5DS axis in hepatocytes that controls the signaling cascades associated with inflammation and apoptosis and confirmed its role in CCl4-induced hepatotoxicity.

7.
Mol Immunol ; 155: 27-43, 2023 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-36682136

RESUMO

AIM: Previously, we revealed a crucial role of 5-HT degradation system (5DS), consisting of 5-HT2A receptor (5-HT2AR), 5-HT synthases and monoamine oxidase A (MAO-A), in ischemia-reperfusion (IR)-caused organ injury. Whereas, platelet activating factor receptor (PAFR) also mediates myocardial ischemia-reperfusion injury (MIRI). Here, we try to clarify the relationship between 5DS and PAFR in mediating MIRI. METHODS: H9c2 cell injury and rat MIRI were caused by hypoxia/reoxygenation (H/R) or PAF, and by ligating the left anterior descending coronary artery then untying, respectively. 5-HT2AR and PAFR antagonists [sarpogrelate hydrochloride (SH) and BN52021], MAO-A, AKT, mTOR and 5-HT synthase inhibitors (clorgyline, perifosine, rapamycin and carbidopa), and gene-silencing PKCε were used in experiments RESULTS: The mitochondrial ROS production, respiratory chain damage, inflammation, apoptosis and myocardial infarction were significantly prevented by BN52021, SH and clorgyline in H/R and PAF-treated cells and in IR myocardium. BN52021 also significantly suppressed the upregulation of PAFR, 5-HT2AR, 5-HT synthases and MAO-A expression (mRNA and protein), and Gαq and PKCε (in plasmalemma) expression induced by H/R, PAF or IR; the effects of SH were similar to that of BN52021 except for no affecting the expression of PAFR and 5-HT2AR. Gene-silencing PKCε suppressed H/R and PAF-induced upregulation of 5-HT synthases and MAO-A expression in cells; perifosine and rapamycin had not such effects; however, clorgyline suppressed H/R and PAF-induced phosphorylation of AKT and mTOR. CONCLUSION: MIRI is probably due to PAFR-mediated 5-HT2AR activation, which further activates PKCε-mediated 5-HT synthesis and degradation, leading to mitochondrial ROS production.

8.
Bioact Mater ; 24: 252-262, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36632501

RESUMO

Ventricular septal defect (VSD) is one of the commonest congenital heart diseases (CHDs). Current occluders for VSD treatment are mainly made of nitinol, which has the risk of nickel allergy, persistent myocardial abrasion and fatal arrythmia. Herein, a fully biodegradable polydioxanone (PDO) occluder equipped with a shape line and poly-l-lactic acid PLLA membranes is developed for VSD closure without the addition of metal marker. PDO occluder showed great mechanical strength, fatigue resistance, geometry fitness, biocompatibility and degradability. In a rat subcutaneous implantation model, PDO filaments significantly alleviated inflammation response, mitigated fibrosis and promoted endothelialization compared with nitinol. The safety and efficacy of PDO occluder were confirmed in a canine VSD model with 3-year follow-up, demonstrating the biodegradable PDO occluder could not only effectively repair VSD, induce cardiac remodeling but also address the complications associated with metal occluders. Furthermore, a pilot clinical trial with five VSD patients indicated that all the occluders were successfully implanted under the guidance of echocardiography and no adverse events occurred during the 3-month follow-up. Collectively, the fully bioresorbable PDO occluder is safe and effective for clinical VSD closure and holds great promise for the treatment of structural CHDs.

9.
J Biophotonics ; : e202200340, 2023 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-36617672

RESUMO

Optical coherence tomography angiography (OCTA) can provide in vivo three-dimensional microvasculature information of bio-tissues, but it is sensitive to motion and time-consuming. To overcome these limitations, we propose an adaptive multiple time interval correlation mapping OCTA with a time-efficient scanning protocol and motion compensation algorithms. A spectral-domain OCT with a center wavelength of 850 nm, A-scan rate of 120 kHz and spatial resolution of 4.1 µm (axial) × 6.9 µm (lateral) is built to reconstruct the microvascular networks in the human arm. By adaptive optimization of the weights of different time interval B-scan angiograms, our novel OCTA technique achieves better performance with a visible vascular density increase of ~67% and a signal-to-noise ratio enhancement of ~11.6%.

10.
Neuromolecular Med ; 2023 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-36639554

RESUMO

Sleep deprivation causes significant memory impairment in healthy adults. Extensive research has focused on identifying the biological mechanisms underlying memory impairment. Microglia-mediated synaptic elimination plays an indispensable role in sleep deprivation. Here, the potential role of the CD33/TREM2 signaling pathway in modulating memory decline during chronic sleep restriction (CSR) was evaluated. In this study, adult male C57BL/6 mice were sleep-restricted using an automated sleep deprivation apparatus for 20 h per day for 7 days. The Y-maze test revealed that spontaneous alternation was significantly reduced in CSR mice compared with control mice. The percentage of exploratory preference for the novel object in CSR mice was significantly decreased compared with that in control mice. These memory deficits correlated with aberrant microglial activation and increased phagocytic ability. Moreover, in CSR mice, the CD33 protein level in hippocampal tissue was significantly downregulated, but the TREM2 protein level was increased. In BV2 microglial cells, downregulation of CD33 increased TREM2 expression and improved microglial phagocytosis. Then, the sialic ligand monosialo-ganglioside 1 (GM1, 20 mg/kg, i.p.) was administered to mice once a day during CSR. Our results further showed that GM1 activated CD33 and consequently disturbed TREM2-mediated microglial phagocytosis. Finally, GM1 reversed CSR-induced synaptic loss and memory impairment via the CD33/TREM2 signaling pathway in the CA1 region of the hippocampus. This study provides novel evidence that activating CD33 and/or inhibiting TREM2 activity represent potential therapies for sleep loss-induced memory deficits through the modulation of microglial phagocytosis.

12.
Sci Total Environ ; 858(Pt 3): 160213, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36423836

RESUMO

The stability of cultivated land ecosystem is crucial to the green and high-quality development of agriculture. Revealing its spatio-temporal differentiation is an important scientific issue to improve the resilience of cultivated land and ensure food security. In this paper, Shenyang, a typical region of Lower Liaohe Plain, is the study area. Starting from the stress buffer response process of cultivated land ecosystem stability, USLE, RWEQ, SDI, RSEI and grey relational model are used to clarify the relationship between the three, and depict the temporal and spatial differentiation pattern of cultivated land ecosystem stability. The results showed that the external stress intensity of cultivated land in Shenyang decreased as a whole, but the stress intensity of cultivated land distributed in the northern and southeast hilly areas increased. Most of the endogenous buffer strength has been improved, and the buffer capacity of cultivated land in the northern hilly region has declined on a large scale. More than half of the response intensity to the effect has been improved, while the response intensity of cultivated land in the west and north has generally declined. The stability of cultivated land ecosystem in Shenyang has been improved for the most part, but in the hilly areas in the north and southeast, the stability in the lower reaches of Liaohe River plain in the south has declined. Terrain conditions and high-intensity cultivation patterns are the important reasons for the temporal and spatial differentiation of cultivated land ecosystem stability in the study area. The study clarified the dynamic process of cultivated land ecosystem stability and provided an important way to grasp the scientific law of stability change.


Assuntos
Ecossistema , China
13.
Neural Regen Res ; 18(7): 1512-1520, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36571356

RESUMO

CDGSH iron sulfur domain 2 can inhibit ferroptosis, which has been associated with cerebral ischemia/reperfusion, in individuals with head and neck cancer. Therefore, CDGSH iron sulfur domain 2 may be implicated in cerebral ischemia/reperfusion injury. To validate this hypothesis in the present study, we established mouse models of occlusion of the middle cerebral artery and HT22 cell models of oxygen-glucose deprivation and reoxygenation to mimic cerebral ischemia/reperfusion injury in vivo and in vitro, respectively. We found remarkably decreased CDGSH iron sulfur domain 2 expression in the mouse brain tissue and HT22 cells. When we used adeno-associated virus and plasmid to up-regulate CDGSH iron sulfur domain 2 expression in the brain tissue and HT22 cell models separately, mouse neurological dysfunction was greatly improved; the cerebral infarct volume was reduced; the survival rate of HT22 cells was increased; HT22 cell injury was alleviated; the expression of ferroptosis-related glutathione peroxidase 4, cystine-glutamate antiporter, and glutathione was increased; the levels of malondialdehyde, iron ions, and the expression of transferrin receptor 1 were decreased; and the expression of nuclear-factor E2-related factor 2/heme oxygenase 1 was increased. Inhibition of CDGSH iron sulfur domain 2 upregulation via the nuclear-factor E2-related factor 2 inhibitor ML385 in oxygen-glucose deprived and reoxygenated HT22 cells blocked the neuroprotective effects of CDGSH iron sulfur domain 2 up-regulation and the activation of the nuclear-factor E2-related factor 2/heme oxygenase 1 pathway. Our data indicate that the up-regulation of CDGSH iron sulfur domain 2 can attenuate cerebral ischemia/reperfusion injury, thus providing theoretical support from the perspectives of cytology and experimental zoology for the use of this protein as a therapeutic target in patients with cerebral ischemia/reperfusion injury.

14.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 40(1): 36-41, 2023 Jan 10.
Artigo em Chinês | MEDLINE | ID: mdl-36584998

RESUMO

OBJECTIVE: To explore the genetic etiology of a Chinese pedigree featuring non-simplex blepharocheilodontic syndrome. METHODS: Whole exome sequencing was carried out to detect genetic variant and copy number variations (CNVs) in the pedigree. Suspected variants were verified by Sanger sequencing and qPCR. RESULTS: The fetus and its elder brother, father and grandfather were found to harbor a heterozygous c.83delG (p.A29Rfs*55) variant of the CTNND1 gene, which was unreported previously. In addition, its elder brother was also found to be a double heterozygote for a c.235delC (p.L79Cfs*3) variant of GJB2 gene and a c.538C>T (p.R180X) variant of GJB3 gene, which were respectively inherited from his mother and father. CNVs analysis revealed a de novo heterozygotic deletion (1.46 Mb) at 17q12 in the mother, which was confirmed by qPCR. Based on American College of Medical Genetics and Genomics guidelines, the c.83delG variant, the c.235delC variant and the 17q12 microdeletion were predicted as pathogenic, while the c.538C>T variant was of uncertain significance. CONCLUSION: The c.83delG (p.A29Rfs*55) variant of the CTNND1 gene probably underlay the pathogenesis of non-simplex blepharocheilodontic syndrome in this pedigree. The double heterozygous variants of c.235delC (p.L79Cfs*3) of GJB2 gene and c.538C>T (p.R180X) of GJB3 gene probably underlay the hearing loss in the elder brother. The bilateral renal cysts in the mother may be attributed to the 17q12 microdeletion. Above results have provided guidance for genetic counseling and prenatal diagnosis for this pedigree.


Assuntos
Variações do Número de Cópias de DNA , Masculino , Gravidez , Feminino , Humanos , Idoso , Linhagem , Mutação , China
15.
J Plast Reconstr Aesthet Surg ; 76: 219-229, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36527904

RESUMO

Recently, there has been renewed interest in autologous fat grafting both for its filler and regenerative traits. The universal application, however, has been impeded by the unstable survival rates and complications. There has been substantial research undertaken on the role of adipose-derived stem cells (ADSCs) involved in fat graft fates including angiogenesis, adipogenesis, and inflammatory regulation. As the effectors of their parental cells, ADSC-derived exosomes (ADSC-exos) encapsulating multiple bioactive cargoes mediate cell-to-cell communication in a paracrine manner. ADSC-exos have received much attention for their biocompatible and efficient therapeutic potentials as "cell-free therapy" in plastic surgery, including increasing fat grafting survival rates. In this review, we summarize the current knowledge about the biological basis of ADSC-exos, ADSC-related mechanisms of fat survival, research updates of ADSC-exos in autologous fat grafting, and discuss some challenges along with research prospects.


Assuntos
Exossomos , Humanos , Tecido Adiposo/transplante , Exossomos/transplante , Adipócitos , Células-Tronco
16.
Spectrochim Acta A Mol Biomol Spectrosc ; 289: 122241, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36529042

RESUMO

4-Hydroxyphenylpyruvate dioxygenase (HPPD) inhibitor herbicides are widely used in modern agriculture. Plant root exudates (REs) play an important role in the adsorption, degradation, migration and transformation of pesticides in soil. In the present study, the structural affinity and interaction mechanism between four HPPD inhibitors (HPPDi) and soybean REs were investigated via multispectral technologies and two-dimensional correlation analysis (2D-COS). UV-vis absorption and fluorescence spectra showed that mesotrione, tembotrione, sulcotrione and topramezone effectively quench the intrinsic fluorescence of soybean REs through static quenching. The binding constant Ka revealed that the binding ability of HPPDi to soybean REs takes the following order: mesotrione > tembotrione > sulcotrione > topramezone. According to the thermodynamic parameters, the main interaction force between tembotrione, sulcotrione, topramezone and soybean REs is electrostatic interaction, while the main interaction force is a hydrogen bond or van der Waals force between mesotrione and soybean REs. The conformational changes of REs were attributed to HPPDi by 3D spectral evaluation. FTIR spectroscopy and 2D-COS analysis suggested that soybean REs mainly formed stable complexes with HPPDi through functional groups such as carbonyl, carboxyl, methoxy and nitrate, and the first binding groups were carbonyl and carboxyl. These results provide helpful information for the adsorption and desorption process of environmental pollutants on the surface of plants and soil.


Assuntos
Herbicidas , 4-Hidroxifenilpiruvato Dioxigenase/antagonistas & inibidores , 4-Hidroxifenilpiruvato Dioxigenase/metabolismo , Exsudatos e Transudatos/metabolismo , Herbicidas/farmacologia , Herbicidas/metabolismo , Soja
17.
Nano Today ; 48: 101730, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36570700

RESUMO

Despite the various vaccines that have been developed to combat the coronavirus disease 2019 (COVID-19) pandemic, the persistent and unpredictable mutations of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) require innovative and unremitting solutions to cope with the resultant immune evasion and establish a sustainable immune barrier. Here we introduce a vaccine-delivery system with a combination of a needle-free injection (NFI) device and a SARS-CoV-2-Spike-specific mRNA-Lipid Nanoparticle (LNP) vaccine. The benefits are duller pain and a significant increase of immunogenicity compared to the canonical needle injection (NI). From physicochemical and bioactivity analyses, the structure of the mRNA-LNP maintains stability upon NFI, contradictory to the belief that LNPs are inclined towards destruction under the high-pressure conditions of NFI. Moreover, mRNA-LNP vaccine delivered by NFI induces significantly more binding and neutralizing antibodies against SARS-CoV-2 variants than the same vaccine delivered by NI. Heterogeneous vaccination of BA.5-LNP vaccine with NFI enhanced the generation of neutralizing antibodies against Omicron BA.5 variants in rabbits previously vaccinated with non-BA.5-specific mRNA-LNP or other COVID-19 vaccines. NFI parameters can be adjusted to deliver mRNA-LNP subcutaneously or intramuscularly. Taken together, our results suggest that NFI-based mRNA-LNP vaccination is an effective substitute for the traditional NI-based mRNA-LNP vaccination.

18.
Biosens Bioelectron ; 222: 114944, 2022 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-36470061

RESUMO

The effective analysis of the basic structure and functional information of bioparticles are of great significance for the early diagnosis of diseases. The synergism between microfluidics and particle manipulation/detection technologies offers enhanced system integration capability and test accuracy for the detection of various bioparticles. Most microfluidic detection platforms are based on optical strategies such as fluorescence, absorbance, and image recognition. Although optical microfluidic platforms have proven their capabilities in the practical clinical detection of bioparticles, shortcomings such as expensive components and whole bulky devices have limited their practicality in the development of point-of-care testing (POCT) systems to be used in remote and underdeveloped areas. Therefore, there is an urgent need to develop cost-effective non-optical microfluidic platforms for bioparticle detection that can act as alternatives to optical counterparts. In this review, we first briefly summarise passive and active methods for bioparticle manipulation in microfluidics. Then, we survey the latest progress in non-optical microfluidic strategies based on electrical, magnetic, and acoustic techniques for bioparticle detection. Finally, a perspective is offered, clarifying challenges faced by current non-optical platforms in developing practical POCT devices and clinical applications.

19.
Heliyon ; 8(11): e11753, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36451755

RESUMO

The continuous growth of global carbon emissions has become the focus of attention in political and academic circles in various countries. Understanding the driving factors of change in urban carbon emissions and predicting the peak of carbon emissions is of great significance for guiding the formulation of urban as well as national carbon emission reduction policies. Using Xi'an as an example, this study analyses the changing trend of its carbon emissions over the past 20 years. Based on carbon emissions and total economic volume, a Tapio decoupling elasticity analysis model was constructed, the decoupling coefficient of Xi'an from 2000 to 2020 was calculated, and the decoupling status of economic growth and carbon emissions were analysed. Using the Kaya identity and logarithmic mean divisia index (LMDI) decomposition to analyse the driving factors of the city's carbon emissions, combined with a multi-scenario forecasting method, three different scenarios were subdivided, and the approximate time of Xi'an's carbon peak was estimated. The results show that from 2000 to 2020, the overall carbon emissions in Xi'an showed an upwards trend. In recent years, the decoupling status of economic growth and carbon emissions in Xi'an has been ideal, and the effect of carbon emission reduction is obvious. Population and per capita gross domestic product (GDP) have a positive driving effect on carbon emissions, and energy intensity has a negative driving force on carbon emissions. During early years, the carbon intensity of energy consumption showed a positive effect on carbon emissions. With the improvement of the energy structure, the intensity of energy consumption inhibits the growth of carbon emissions. Under the three scenarios of low carbon, baseline and high carbon, the carbon peak years will be achieved approximately in 2016, 2025 and 2035, and the corresponding carbon peaks are approximately 29.5 million tons, 29.66 million tons and 31 million tons, respectively.

20.
J Org Chem ; 2022 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-36473161

RESUMO

A new, simple, and metal-free route for the diselenation of maleimides has been first developed employing (bis(trifluoroacetoxy)iodo)benzene (PIFA) at room temperature. The present method is compatible with different functional groups, and various diselenyl maleimides were obtained in moderate to excellent yields. Moreover, this protocol further highlights the unique practical application for the functionalization of biologically relevant molecules and amino acid derivatives. Preliminary mechanism studies suggest that radicals may be involved in this novel transformation. Additionally, this protocol is also applicable for the monoselenation of maleimides by switching the reaction conditions and selenation of other electron-deficient alkenes.

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