Heat waves and urban heat islands (UHIs) may interact together, but the dependence of their interaction on background climate is unclear. Hourly meteorological observations in June to August from 2013 to 2015 collected in the megacities of Beijing (temperate semihumid monsoon climate), Shanghai (subtropical humid monsoon climate), and Guangzhou (marine subtropical monsoon climate) in China were used to study the interaction. At each megacity, eight rural stations and eight urban stations, respectively, were selected to study the UHI. Although under different background climates, UHIs in Beijing and Guangzhou shared a similar diurnal variability, that is, higher in the nighttime. However, the diurnal cycle is opposite for Shanghai if rural coastal stations were selected as rural reference stations. During heat wave periods, daytime (10:00–16:00) UHIs were intensified by 0.9 ± 0.13 (mean ± 1 standard deviation) °C in Shanghai, nighttime (22:00–4:00) UHIs were intensified by 0.9 ± 0.36 and 0.8 ± 0.20 °C in Beijing and Guangzhou, respectively. The surface solar radiation during the heat wave period was approximately 1.5 times to that under normal conditions in each city. The enhanced solar radiation during heat waves, which was absorbed by the urban canopy in the daytime and released at night, was closely related to nighttime UHIs in Beijing and Guangzhou and daytime UHIs in Shanghai. Additionally, changes in wind direction were observed in Shanghai under heat waves, that is, with more than 63% (wind direction) of the wind originating from neighboring hot cities in the southwest instead of the cool sea breeze from the southeast, which led to a significant increase in daytime UHIs during heat wave periods.
This study compared the diurnal and seasonal cycles of atmospheric and surface urban heat islands (UHIs) based on hourly air temperatures (Ta) collected at 65 out of 262 stations in Beijing and land surface temperature (Ts) derived from Moderate Resolution Imaging Spectroradiometer in the years 2013–2014. We found that the nighttime atmospheric and surface UHIs referenced to rural cropland stations exhibited significant seasonal cycles, with the highest in winter. However, the seasonal variations in the nighttime UHIs referenced to mountainous forest stations were negligible, because mountainous forests have a higher nighttime Ts in winter and a lower nighttime Ta in summer than rural croplands. Daytime surface UHIs showed strong seasonal cycles, with the highest in summer. The daytime atmospheric UHIs exhibited a similar but less seasonal cycle under clear‐sky conditions, which was not apparent under cloudy‐sky conditions. Atmospheric UHIs in urban parks were higher in daytime. Nighttime atmospheric UHIs are influenced by energy stored in urban materials during daytime and released during nighttime. The stronger anthropogenic heat release in winter causes atmospheric UHIs to increase with time during winter nights, but decrease with time during summer nights. The percentage of impervious surfaces is responsible for 49%–54% of the nighttime atmospheric UHI variability and 31%–38% of the daytime surface UHI variability. However, the nighttime surface UHI was nearly uncorrelated with the percentage of impervious surfaces around the urban stations.
Background:The most effective treatment with immune checkpoint inhibitors (ICIs) is limited to the microsatellite instability high (MSI-H) subgroup of advanced colorectal cancer. ICIs are completely ineffective in microsatellite stabilized (MSS) patients with advanced colorectal cancer. Fruquintinib, a tyrosine kinase inhibitor (TKI) domestically made in China that specifically inhibits vascular endothelial growth factor receptors, is used to treat refractory metastatic colorectal cancer (mCRC). Researches showed that anti-angiogenic therapy combined with immunotherapy induces a long-lasting antitumor immune response. Here, we aimed to evaluate antitumor efficacy and safety of fruquintinib with anti-programmed death-1 (PD-1) antibody toripalimab in Chinese patients with non-MSI-H/mismatch repair proficient (pMMR) mCRC.Methods: This was a single-arm, single-center, prospective, phase II clinical trial. A total of 19 MSS patients with refractory or advanced mCRC were enrolled They received fruquintinib (5 mg, orally, once daily for 3 weeks followed by 1 week off in 4-week cycles) and toripalimab (240 mg, intravenously administered on day 1 once every 3 weeks) until disease progression or unacceptable toxicity. The objective response rate (ORR), progression-free survival (PFS), overall survival (OS), 1-year PFS rate, disease control rate (DCR), and toxicity were reviewed and evaluated. The Cox regression model was used to analyze the influence on OS and PFS.Results: Among the 19 patients, the median age was 52 years (range, 30-71 years); 4 patients (21.05%) achieved partial response, 10 patients (52.63%) experienced stable disease, and 4 patients (21.05%) experienced progressive disease. The ORR was 21.05%. The median PFS and OS were 5.98 months and 11.10 months, respectively. Patients with peritoneal metastasis received greater benefit from combination therapy, with a longer PFS (P=0.043) in the univariate analysis. The most common treatment-related adverse reactions were fatigue (57.89%), hepatic dysfunction (42.11%) and hypertension (36.84%). No serious adverse effects or adverse effect-related deaths were reported.
Conclusions:Our study provides evidence supporting fruquintinib combined with an anti-PD-1 monoclonal antibody have the better effect than fruquintinib alone in the third-line setting for Chinese patients with MSS advanced colorectal cancer. Primary lesion excision and peritoneal metastasis were independent prognostic factors of PFS. Further well-designed, prospective, large-scale studies are needed to validate this outcome.
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