STEAP3 promotes colon cancer cell proliferation and migration via regulating histone acetylation.

Colorectal cancer (CRC) is the third most prevalent diagnosed cancer in men and second most prevalent cancer in women. H3K27ac alterations are more commonly than gene mutations in colorectal cancer. Most colorectal cancer genes have significant H3K27ac changes, which leads to an over-expression disorder in gene transcription. Over-expression of STEAP3 is involved in a variety of tumors, participating in the regulation of cancer cell proliferation and migration. The purpose of this work is to investigate the role of STEAP3 in the regulation of histone modification (H3K27ac) expression in colon cancer. Bioinformatic ChIP-seq, ChIP-qPCR and ATAC-seq were used to analyze the histone modification properties and gene accessibility of STEAP3. Western blot and qRT-PCR were used to evaluate relative protein and gene expression, respectively. CRISPR/Cas9 technology was used to knockout STEAP3 on colon cancer cells to analyze the effect of ATF3 on STEAP3. STEAP3 was over-expressed in colon cancer and associated with higher metastases and more invasive and worse stage of colon cancer. ChIP-seq and ChIP-qPCR analyses revealed significant enrichment of H3K27ac in the STEAP3 gene. In addition, knocking down STEAP3 significantly inhibits colon cancer cell proliferation and migration and down-regulates H3K27ac expression. ChIP-seq found that ATF3 is enriched in the STEAP3 gene and CRISPR/Cas9 technology used for the deletion of the ATF3 binding site suppresses the expression of STEAP3. Over-expression of STEAP3 promotes colon cancer cell proliferation and migration. Mechanical studies have indicated that H3K27ac and ATF3 are significantly enriched in the STEAP3 gene and regulate the over-expression of STEAP3.

Nomogram for predicting the surgical difficulty of laparoscopic total mesorectal excision and exploring the technical advantages of robotic surgery.

Background: Total mesorectal excision (TME), represents a key technique in radical surgery for rectal cancer. This study aimed to construct a preoperative nomogram for predicting the surgical difficulty of laparoscopic total mesorectal excision (L-TME) and to investigate whether there were potential benefits of robotic TME (R-TME) for patients with technically challenging rectal cancer. Methods: Consecutive mid-low rectal cancer patients receiving total mesorectal excision were included. A preoperative nomogram to predict the surgical difficulty of L-TME was established and validated. Patients with technically challenging rectal cancer were screened by calculating the prediction score of the nomogram. Then patients with technically challenging rectal cancer who underwent different types of surgery, R-TME or L-TME, were analyzed for comparison. Results: A total of 533 consecutive patients with mid-low rectal cancer who underwent TME at a single tertiary medical center between January 2018 and January 2021 were retrospectively enrolled. Multivariable analysis demonstrated that mesorectal fat area, intertuberous distance, tumor size, and tumor height were independent risk factors for surgical difficulty. Subsequently, these variables were used to construct the nomogram model to predict the surgical difficulty of L-TME. The area under the receiver operating characteristic curve of the nomogram was 0.827 (95% CI 0.745 - 0.909) and 0.809 (95% CI 0.674- 0.944) in the training and validation cohort, respectively. For patients with technically challenging rectal cancer, R-TME was associated with a lower diverting ileostomy rate (p = 0.003), less estimated blood loss (p < 0.043), shorter procedure time (p = 0.009) and shorter postoperative hospital stay (p = 0.037). Conclusion: In this study, we established a preoperative nomogram to predict the surgical difficulty of L-TME. Furthermore, this study also indicated that R-TME has potential technical advantages for patients with technically challenging rectal cancer.

p53-dependent HIF-1α /autophagy mediated glycolysis to support Cr(VI)-induced cell growth and cell migration.

Cr(VI) is known to be seriously toxic and carcinogenic. Hypoxia-inducible factor-1α (HIF-1α) is a crucial regulator to promote tumor development. In this study, we found that Cr(VI) significantly increased the expression of HIF-1α in A549 cells and in lung of BALB/c mice but not in HELF cells. Treatment with Lificiguat (YC-1), HIF-1α inhibitor, or CoCl2, HIF-1α inducer, could alter Cr(VI)-induced autophagy, glycolysis, and cell growth in A549 cells but not in HELF cells, validating the involvement of HIF-1α in these effects of Cr(VI) in A549 cells. Co-treatments of pcATG4B with YC-1, or siATG4B with CoCl2 demonstrated the role of HIF-1α / autophagy axis in inducing glycolysis and cell growth in A549 cells. In HELF cells, however, only autophagy but not HIF-1α played a role in inducing glycolysis. The protein level of p53 was significantly lower in A549 cells than in HELF cells. RITA, a p53 inducer, attenuated Cr(VI)-induced HIF-1α and LC3-II in A549 cells, suggesting that p53 might be the mechanism underlying the different effects of Cr(VI) on HIF-1α in A549 and HELF cells. Thus, p53-dependent HIF-1α / autophagy-mediated glycolysis plays a role in facilitating Cr(VI)-induced carcinogenesis.

Modified aortic root anastomosis and the frozen elephant trunk technique using an integrated tetra-furcate graft to repair type A aortic dissection.

BACKGROUND: Surgery is the preferred treatment for acute Stanford type A aortic dissection (STAAD); however, due to the complexity of the procedure, cardiac ischaemia and cardiopulmonary bypass (CPB) time are longer than general heart surgery, leading to complications. In this present study, we used an integrated tetra-furcate graft for both modified aortic root and distal arch anastomoses (frozen elephant trunk technique, [FET]), and investigated postoperative outcomes associated with this technique in patients with STAAD. METHODS: We included a total of 140 patients who underwent total arch replacement and FET between January 2019 and June 2022 in the present study, 41 patients who underwent the modified technique, and 99 who underwent the graft eversion technique. We subsequently analyzed the perioperative outcomes to compare the differences between the two techniques. RESULTS: There were no statistically significant differences between the two groups in regards to the preoperative characteristics; however, the intraoperative CPB, cardiac ischaemia, and operation times of the modified technique group were significantly shorter than those of the eversion technique group (P = 0.02, P = 0.01, and P = 0.04, respectively), as were postoperative hypoxaemia, intensive care unit (ICU) stay, and ventilation times (P = 0.04, P = 0.03, and P = 0.04, respectively). Additionally, the degree of postoperative bilirubin elevation was milder in the modified technique group (P = 0.002 for direct bilirubin and P = 0.01 for indirect bilirubin). CONCLUSIONS: The modified anastomosis technique can significantly shorten CPB, cardiac ischemia, and operation times, and reduce the intraoperative FFP transfusion and postoperative hypoxemia times. This modified technique, therefore, is worth utilizing for patients with STAAD.

Nomogram for predicting prolonged postoperative ileus after laparoscopic low anterior resection for rectal cancer.

BACKGROUND: Prolonged postoperative ileus (PPOI) is a common complication after colorectal surgery that increases patient discomfort, hospital stay, and financial burden. However, predictive tools to assess the risk of PPOI in patients undergoing laparoscopic low anterior resection have not been developed. Thus, the purpose of this study was to develop a nomogram to predict PPOI after laparoscopic low anterior resection for rectal cancer. METHODS: A total of 548 consecutive patients who underwent laparoscopic low anterior resection for mid-low rectal cancer at a single tertiary medical center were retrospectively enrolled between January 2019 and January 2023. Univariate and multivariate logistic regression analysis was performed to analyze potential predictors of PPOI. The nomogram was constructed using the filtered variables and internally verified by bootstrap resampling. Model performance was evaluated by receiver operating characteristic curve and calibration curve, and the clinical usefulness was evaluated by the decision curve. RESULTS: Among 548 consecutive patients, 72 patients (13.1%) presented with PPOI. Multivariate logistic analysis showed that advantage age, hypoalbuminemia, high surgical difficulty, and postoperative use of opioid analgesic were independent prognostic factors for PPOI. These variables were used to construct the nomogram model to predict PPOI. Internal validation, conducted through bootstrap resampling, confirmed the great discrimination of the nomogram with an area under the curve of 0.738 (95%CI 0.736-0.741). CONCLUSIONS: We created a novel nomogram for predicting PPOI after laparoscopic low anterior resection. This nomogram can assist surgeons in identifying patients at a heightened risk of PPOI.

Augmenting interpretable models with large language models during training.

Recent large language models (LLMs), such as ChatGPT, have demonstrated remarkable prediction performance for a growing array of tasks. However, their proliferation into high-stakes domains and compute-limited settings has created a burgeoning need for interpretability and efficiency. We address this need by proposing Aug-imodels, a framework for leveraging the knowledge learned by LLMs to build extremely efficient and interpretable prediction models. Aug-imodels use LLMs during fitting but not during inference, allowing complete transparency and often a speed/memory improvement of greater than 1000x for inference compared to LLMs. We explore two instantiations of Aug-imodels in natural-language processing: Aug-Linear, which augments a linear model with decoupled embeddings from an LLM and Aug-Tree, which augments a decision tree with LLM feature expansions. Across a variety of text-classification datasets, both outperform their non-augmented, interpretable counterparts. Aug-Linear can even outperform much larger models, e.g. a 6-billion parameter GPT-J model, despite having 10,000x fewer parameters and being fully transparent. We further explore Aug-imodels in a natural-language fMRI study, where they generate interesting interpretations from scientific data.

Transcriptomic analysis revealing the molecular response to arsenic stress in desert Eremostachys moluccelloides Bunge.

The saline, alkaline environment of arid soils is conducive to the diffusion of the metalloid arsenic (As). Desert plants in this area are of great ecological importance and practical value. However, there are few studies on the mechanism of arsenic action in desert plants. Therefore, in this study, Eremostachys moluccelloides Bunge was treated with different concentrations of As2O5 [As(V)] to analyze the physiological, biochemical, and transcriptomic changes of its roots and leaves and to explore the molecular mechanism of its response to As(Ⅴ) stress. The activities of catalase, superoxidase, peroxidase, and the contents of malondialdehyde and proline in roots and leaves first increased and then decreased under the As(Ⅴ) stress of different concentrations. The content of As was higher in roots than in leaves, and the As content was positively correlated with As(Ⅴ) stress concentration. In the differentially expressed gene analysis, the key enzymes of the oxidative stress response in roots and leaves were significantly enriched in the GO classification. In the KEGG pathway, genes related to the abscisic acid signal transduction pathway were co-enriched and up-regulated in roots and leaves. The related genes in the phenylpropanoid biosynthesis pathway were significantly enriched and down-regulated only in roots. In addition, the transcription factors NAC, HB-HD-ZIP, and NF-Y were up-regulated in roots and leaves. These results suggest that the higher the As(V) stress concentration, the more As is taken up by roots and leaves of E. molucelloides Bunge. In addition to causing greater oxidative damage, this may interfere with the production of secondary metabolites. Moreover, it may improve As(V) tolerance by regulating abscisic acid and transcription factors. The results will deepen our understanding of the molecular mechanism of As(Ⅴ) response in E. moluccelloides Bunge, lay the foundation for developing and applying desert plants, and provide new ideas for the phytoremediation of As pollution in arid areas.

[Effect of electroacupuncture on proliferation and differentiation of endogenous neural stem cells and Jagged1/Notch1 pathway in hippocampus of APP/PS1 model mice].

OBJECTIVE: To investigate the effect of electroacupuncture(EA) stimulation on proliferation and diffe-rentiation of endogenous neural stem cells as well as Jagged1/Notch1 pathway in AD model mice, so as to explore its mechanism underlying amelioration of AD. METHODS: A total of 40 6-week-old male APP/PS1 transgenic AD mice were randomly divided into EA group (n=20) and AD model group ( n=20), and other 20 normal C57BL/6J mice of the same age were used as the normal control group. The mice in the EA group received EA (10 Hz, 2 mA) at "Baihui"(GV20), "Fengfu"(GV16) and bilateral "Shenshu" (BL23) for 20 min, once daily, 6 days a week for 16 weeks. The mice's learning-memory ability was detected by Morris water maze tests. The Aß senile plaques in the hippocampal CA1 region were detected by Congo red staining, the immunofluorescence double label of BrdU, neuronal nuclear antigen (NeuN) and astrocyte specific protein GFAP in dentate gyrus of hippocampus was performed for detecting the proliferation and differentiation of the endogenous neural stem cells. The expression levels of Nestin (neuron specific protein) and GFAP were detected by Western blot, and those of Jagged1 and Notch1 mRNAs and proteins in the hippocampus were detected by real-time fluorescence quantifative PCR and Western blot. RESULTS: Compared with the normal control group, the escape latencies at 2nd, 3rd and 4th day, and Aß senile plaques were significantly increased (P<0.05, P<0.01), whereas the platform crossing times and time spent in the target quadrant, the expression levels of Jagged1 mRNA and Nestin protein were remarkably down-regulated (P<0.05) in the model group. Following EA intervention, the escape latencies at the 3rd and 4th day, Aß senile plaques, immunofluorescence density of BrdU/GFAP, and GFAP protein expression were pronouncedly decreased (P<0.05, P<0.01), while the platform crossing times, platform quadrant residence time, immunofluorescence density of BrdU/NeuN, expression levels of Jagged1 and Notch1 mRNAs and proteins and Nestin protein evidently increased (P<0.05, P<0.01), suggesting an enhancement of proliferation and diffe-rentiation of endogenous neural stem cells into neurons and a suppression of the proliferation and differentiation towards astrocytes in the hippocampus. CONCLUSION: EA at GV20, GV16 and BL23 can improve the learning-memory ability, promote the proliferation and differentiation of endogenous neural stem cells towards neurons and inhibit the proliferation and differentiation of endogenous neural stem cells towards astrocytes in the hippocampus, which may be achieved by regulating Jagged1/Notch1 pathway.

Effect of minimally invasive versus conventional aortic root replacement on transfusion and postoperative wound complications in patients: A meta-analysis.

We examined whether small incision aortic root replacement could reduce the amount of blood transfusion during operation and the risk of postoperative complications. An extensive e-review of the 4 main databases (PubMed, Cochrane, Web of Science and EMBASE) was carried out to determine all the published trials by July 2023. The search terms used were associated with partial versus full sternotomy and aortic root. This analysis only included the study articles that compared partial and full sternotomy. After excluding articles based on titles or abstracts, selected full-text articles had reference lists searched for any potential further articles. We analysed a total of 2167 subjects from 10 comparable trials. The minimally invasive aortic root graft in breastbone decreased the duration of hospitalization (MD, -2.58; 95% CI, -3.15, -2.01, p < 0.0001) and intraoperative red blood cell transfusion (MD, -1.27; 95% CI, -2.34, -0.19, p = 0.02). However, there were no significant differences in wound infection (OR, 0.88; 95% CI, 0.16, 4.93, p = 0.88), re-exploration for bleeding (OR, 0.96; 95% CI, 0.60, 1.53, p = 0.86), intraoperative blood loss (MD, -259.19; 95% CI, -615.11, 96.73, p = 0.15) and operative time (MD, -7.39; 95% CI, -19.10, 4.32, p = 0.22); the results showed that the microsternotomy did not differ significantly from that of the routine approach. Small sternotomy may be an effective and safe substitute for the treatment of the aorta root. Nevertheless, the wide variety of data indicates that larger, well-designed studies are required to back up the current limited literature evidence showing a benefit in terms of complications like postoperative wound infections or the volume of intraoperative red blood cell transfusion.

Enhanced Mechanical Properties of PVA Hydrogel by Low-Temperature Segment Self-Assembly vs. Freeze-Thaw Cycles.

The rapid and effective fabrication of polyvinyl alcohol (PVA) hydrogels with good mechanical properties is of great significance yet remains a huge challenge. The preparation of PVA hydrogels via the conventional cyclic freeze-thaw method is intricate and time-intensive. In this study, a pioneering approach involving the utilization of low-temperature continuous freezing is introduced to produce a novel PVA-ethylene glycol (EG) gel. Fourier transform infrared (FTIR) spectroscopy, X-ray diffractometry (XRD) and scanning electron microscopy (SEM) confirm that with the assistance of EG, PVA molecular chains can self-assemble to generate an abundance of microcrystalline domains at low temperatures, thus improving the mechanical properties of PVA-EG gel. Remarkably, when the mass ratio of H2O/EG is 4:6, the gel's maximum tensile strength can reach 2.5 MPa, which is much higher than that of PVA gels prepared via the freeze-thaw method. The preparation process of PVA-EG gel is simple, and its properties are excellent, which will promote the wide application of PVA tough gel in many fields.

Study of Selective Dry Etching Effects of 15-Cycle Si0.7Ge0.3/Si Multilayer Structure in Gate-All-Around Transistor Process.

Gate-all-around (GAA) structures are important for future logic devices and 3D-DRAM. Inner-spacer cavity etching and channel release both require selective etching of Si0.7Ge0.3. Increasing the number of channel-stacking layers is an effective way to improve device current-driving capability and storage density. Previous work investigated ICP selective etching of a three-cycle Si0.7Ge0.3/Si multilayer structure and the related etching effects. This study focuses on the dry etching of a 15-cycle Si0.7Ge0.3/Si multilayer structure and the associated etching effects, using simulation and experimentation. The simulation predicts the random effect of lateral etching depth and the asymmetric effect of silicon nanosheet damage on the edge, both of which are verified by experiments. Furthermore, the study experimentally investigates the influence and mechanism of pressure, power, and other parameters on the etching results. Research on these etching effects and mechanisms will provide important points of reference for the dry selective etching of Si0.7Ge0.3 in GAA structures.

Influence of a Multiple Epoxy Chain Extender on the Rheological Behavior, Crystallization, and Mechanical Properties of Polyglycolic Acid.

This study investigated the impact of a multiple epoxy chain extender (ADR) on the rheological behavior, crystallization, and mechanical properties of polyglycolic acid (PGA). Tests of the torque and melt mass flow rate and dynamic rheological analysis were conducted to study the rheological behavior of PGA modified with ADR. The rheological results of the modified PGA showed a significantly increased viscosity and storage modulus with an increase in the ADR amount, which could be attributed to the chain extension/branching reactions between PGA and ADR. It was proved that ADR could be used as an efficient chain extender for tailoring the rheological performance of PGA. The Han plot of the modified PGA showed a transition of viscous behavior to elastic behavior, while the ADR content was increased from 0 to 0.9 phr. The formation of long-chain branches (LCBs) was confirmed via the Cole-Cole plot and weighted relaxation spectrum, wherein the LCBs substantially changed the rheological behavior of the modified PGA. The vGP plots predicted a star-type topological structure for the LCBs. The results of non-isothermal crystallization kinetics suggested that the crystallization of the modified PGA was predominantly homogeneous nucleation and three-dimensional growth. The crystallinity decreased slightly with the increase in the ADR amount. Compared to neat PGA, the modified PGA samples exhibited better tensile and flexural performances.

Case report: Surgery combined with extracorporeal membrane oxygenation for a patient with type A aortic dissection complicated with myocardial infarction after percutaneous coronary intervention.

Background: Aortic dissection (AD) is a severe cardiovascular disease characterized by aortic rupture, aortic valve insufficiency, aortic branch lumen stenosis, and occlusion. Acute ST-segment elevation myocardial infarction may be the primary manifestation when aortic dissection affects the coronary artery, leading to delayed or missed diagnosis of aortic dissection, and preventing patients from receiving timely and comprehensive treatment. Simultaneous aortic repair and coronary artery bypass grafting surgery are controversial because of their high mortality rates. Personalized and optimal treatment plans for patients should be taken seriously based on their different conditions and treatment options. Case presentation: A 42-year-old man who experienced 1 h of persistent precordialgia was admitted to a local second-level hospital for emergency treatment. Electrocardiogram (ECG) showed evidence of ST-segment elevation, and myocardial enzyme levels were CK-MB 18.35 ng/ml and troponin 0.42 ng/ml. The patient was treated for acute myocardial infarction (AMI) and urgently sent to the interventional catheter room. Coronary angiography showed stenosis of the starting part of the right coronary artery trunk. Thus, stent implantation was performed, and the stenosis section recovered patency; however, postoperative precordialgia was not alleviated. Computed tomography angiography (CTA) revealed a type A AD. The patient was immediately transferred to a higher-level hospital, underwent emergency surgery with cardiopulmonary bypass (CPB) ascending aorta replacement, SUN's procedure (total arch replacement and stented elephant trunk implantation), and simultaneous implantation of extracorporeal membrane oxygenation (ECMO), and regained consciousness within intensive care unit care. ECMO was discontinued when hemodynamics stabilized. The patient ultimately recovered well and was discharged. Conclusion: This case demonstrated that precordialgia is not limited to myocardial infarction but may also be accompanied by aortic dissection. Percutaneous coronary intervention (PCI) can timely and effectively restore coronary artery perfusion, strive for the opportunity of aortic repair surgery, and can overcome pump failure caused by myocardial infarction, cardiopulmonary bypass, heart block time, and myocardial ischemia-reperfusion injury. Personalized treatment is crucial for patients with complex type A aortic dissection.

Radiofrequency ablation-induced superior vena cava stenosis in a 5-year-old boy with congenital left atrial appendage deformity: a case report and literature review.

Superior vena cava (SVC) stenosis is rarely caused by iatrogenic trauma. Herein, the case of a 5-year-old boy who underwent radiofrequency ablation for paroxysmal supraventricular tachycardia but developed SVC stenosis and related syndromes is reported. Notably, the child exhibited an enlarged left atrial appendage that had partially breached the pericardium. Subsequent interventions involved successful removal of the stenosis, artificial vascular reconstruction, and comprehensive radiofrequency ablation of the entire right atrium, along with ligation of the left atrial appendage under direct vision. As a result, the child experienced relief from symptoms.

High-dimensional single-cell analysis unveils distinct immune signatures of peripheral blood in patients with pancreatic ductal adenocarcinoma.

Introduction: Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies with poor response to immune checkpoint inhibitors. The mechanism of such poor response is not completely understood. Methods: We assessed T-cell receptor (TCR) repertoire and RNA expression at the single-cell level using high-dimensional sequencing of peripheral blood immune cells isolated from PDAC patients and from healthy human controls. We validated RNA-sequencing data by performing mass cytometry (CyTOF) and by measuring serum levels of multiple immune checkpoint proteins. Results: We found that proportions of T cells (CD45+CD3+) were decreased in PDAC patients compared to healthy controls, while proportion of myeloid cells was increased. The proportion of cytotoxic CD8+ T cells and the level of cytotoxicity per cell were increased in PDAC patients, with reduced TCR clonal diversity. We also found a significantly enriched S100A9+ monocyte population and an increased level of TIM-3 expression in immune cells of peripheral blood in PDAC patients. In addition, the serum level of soluble TIM-3 (sTIM-3) was significantly higher in PDAC patients compared to the non-PDAC participants and correlated with worse survival in two independent PDAC cohorts. Moreover, sTIM-3 exhibited a valuable role in diagnosis of PDAC, with sensitivity and specificity of about 80% in the training and validation groups, respectively. We further established an integrated model by combining sTIM-3 and carbohydrate antigen 19- 9 (CA19-9), which had an area under the curve of 0.974 and 0.992 in training and validation cohorts, respectively. Conclusion: Our RNA-seq and proteomic results provide valuable insight for understanding the immune cell composition of peripheral blood of patients with PDAC.

Platelet-rich plasma influence on the sternal wounds healing: A meta-analysis.

A meta-analysis research was executed to appraise the effect of platelet-rich plasma (PRP) on sternal wound healing (SWH). Inclusive literature research till April 2023 was done and 1098 interconnected researches were revised. The 11 picked researches, enclosed 8961 cardiac surgery (CS) persons were in the utilised researchers' starting point, 3663 of them were utilising PRP, and 5298 were control. Odds ratio (OR) and 95% confidence intervals (CIs) were utilised to appraise the effect of PRP on the SWH by the dichotomous approach and a fixed or random model. PRP had significantly lower sternal wound infection (SWI) (OR, 0.11; 95% CI, 0.03-0.34, p < 0.001), deep SWI (OR, 0.29; 95% CI, 0.16-0.51, p < 0.001), and superficial SWI (OR, 0.20; 95% CI, 0.13-0.33, p < 0.001), compared to control in CS persons. PRP had significantly lower SWI, deep SWI, and superficial SWI, compared to control in CS persons. However, caution must be taken when interacting with its values since there was a low sample size of some of the nominated research found for the comparisons in the meta-analysis.

Anthropogenic heat variation during the COVID-19 pandemic control measures in four Chinese megacities.

Anthropogenic heat (AH) is an important input for the urban thermal environment. While reduction in AH during the Coronavirus disease 2019 (COVID-19) pandemic may have weakened urban heat islands (UHI), quantitative assessments on this are lacking. Here, a new AH estimation method based on a remote sensing surface energy balance (RS-SEB) without hysteresis from heat storage was proposed to clarify the effects of COVID-19 control measures on AH. To weaken the impact of shadows, a simple and novel calibration method was developed to estimate the SEB in multiple regions and periods. To overcome the hysteresis of AH caused by heat storage, RS-SEB was combined with an inventory-based model and thermal stability analysis framework. The resulting AH was consistent with the latest global AH dataset and had a much higher spatial resolution, providing objective and refined features of human activities during the pandemic. Our study of four Chinese megacities (Wuhan, Shanghai, Beijing, and Guangzhou) indicated that COVID-19 control measures severely restricted human activities and notably reduced AH. The reduction was up to 50% in Wuhan during the lockdown in February 2020 and gradually decreased after the lockdown was eased in April 2020, similar to that in Shanghai during the Level 1 pandemic response. In contrast, AH was less reduced in Guangzhou during the same period and increased in Beijing owing to extended central heating use in winter. AH decreased more in urban centers and the change in AH varied in terms of urban land use between cities and periods. Although UHI changes during the COVID-19 pandemic cannot be entirely attributed to AH changes, the considerable reduction in AH is an important feature accompanying the weakening of the UHI.

Characteristics of anthropogenic heat with different modeling ideas and its driving effect on urban heat islands in seven typical Chinese cities.

Anthropogenic heat (AH), an essential urban heat source, is often overlooked or simplified in research on the multiple temporal and spatial driving mechanisms of the urban heat island (UHI), and case studies investigating the impacts of different AH connotations are scarce. This study estimated the AH in seven typical Chinese cities based on a remote sensing surface energy balance model (AHseb) and an energy consumption inventory-machine learning model (AHinv). The intensity of the surface UHI was extracted using land surface temperatures, and then the linear mixed-effects model and geographic detectors were used to analyze the driving effect of AH on the UHI. Despite the similar shapes of the spatial profile curves, the AH derived from the two models differed in both temporal and spatial characteristics, which was more typical in winter and in urban centers, and AHinv had a more notable central spread feature than AHseb. The AH driving effects on UHI were notably influenced by spatial and temporal heterogeneity, particularly in regions with distinct background climates. However, after controlling for the random effects of the background climate, AH still exhibited a considerable enhancing effect on the UHI. AHseb outperformed AHinv in terms of linear positive correlation and interpretation rate for UHI. Meanwhile, interactions with other potential factors enhanced AH driving effects. Consequently, UHI mitigation must be tailored to the local context by integrating multiple drivers, and for the heating effects of AH, it is necessary to develop specific mitigation measures by limiting the conversion of AHinv to AHseb in addition to reducing the heat production. The findings offer guidance for analyzing and optimizing urban thermal climates with a focus on AH or energy consumption control.