Objectives: Although COVID-19 is known to be caused by human-to-human transmission, it remains largely unclear whether ambient air pollutants and meteorological parameters could promote its transmission. Methods: A retrospective study was conducted to study whether air quality index (AQI), four ambient air pollutants (PM 2.5 , PM 10 , NO 2 and CO) and five meteorological variables (daily temperature, highest temperature, lowest temperature, temperature difference and sunshine duration) could increase COVID-19 incidence in Wuhan and XiaoGan between Jan 26th to Feb 29th in 2020. Results: First, a significant correlation was found between COVID-19 incidence and AQI in both Wuhan (R 2 = 0.13, p < 0.05) and XiaoGan (R 2 = 0.223, p < 0.01). Specifically, among four pollutants, COVID-19 incidence was prominently correlated with PM 2.5 and NO 2 in both cities. In Wuhan, the tightest correlation was observed between NO 2 and COVID-19 incidence (R 2 = 0.329, p < 0.01). In XiaoGan, in addition to the PM 2.5 (R 2 = 0.117, p < 0.01) and NO 2 (R 2 = 0.015, p < 0.05), a notable correlation was also observed between the PM 10 and COVID-19 incidence (R 2 = 0.105, p < 0.05). Moreover, temperature is the only meteorological parameter that constantly correlated well with COVID-19 incidence in both Wuhan and XiaoGan, but in an inverse correlation (p < 0.05). Conclusions: AQI, PM 2.5 , NO 2 , and temperature are four variables that could promote the sustained transmission of COVID-19.

ObjectiveTo understand whether ambient air pollutants and meteorological variables are associated with daily COVID-19 incidence. DesignA retrospective cohort during Jan 25 th to Feb 29 th in 2020. SettingCity of Wuhan, XiaoGan and HuangGang. PatientsThe COVID-19 incidence per day. MethodsWe collected daily data of COVID-19 incidence, eight ambient air pollutants (PM2.5, PM10, SO2, CO, NO2, and O3-8h) and three meteorological variables (temperature, relative humidity and wind level) in China's three worst COVID-19 hit cities during the study period. The multivariate Poisson regression was performed to understand their correlation. ResultsOur data showed that daily COVID-19 incidence was positively associated with PM 2.5 and humidity in all cities. Specifically, the relative risk (RR) of PM 2.5 was 1.036 (95% confidence interval [CI], 1.032 -1.039), 1.059 (95% CL, 1.046 -1.072) and 1.144 (95% CL, 1.12 -1.169) for COVID-19 incidence per day in Wuhan, XiaoGan and HuangGang, respectively. The RR of humidity was constantly lower than that of PM2.5, whose difference ranged from 0.027 to 0.111. Moreover, PM 10 and temperature also exhibited a notable correlation with daily COVID-19 incidence, but in a negative pattern The RR of PM 10 raged from 0.915 (95% CL, 0.896 -0.934) to 0.961 (95% CL, 0.95 -0.972) while that of temperature was 0.738 (95% CL, 0.717 -0.759) to 0.969 (95% CL, 0.966 -0.973). Conclusions.Our data suggested that PM 2.5 /humidity and PM 10 /temperature could substantially increase and decrease the risk of COVID-19 incidence, respectively.

a b s t r a c tThe paper analyzes the potential for delays to propagate in passenger airline networks. The aim is to better understand the relationship between the scheduling of aircraft and crew, and the operational performance of such schedules. In particular, when carriers decide how to schedule costly resources, the focus is primarily on achieving high levels of utilization. The resulting plans, however, often have little slack, limiting the schedule's ability to absorb disruption; instead, initial flight delays may propagate to delay subsequent flights as well. Understanding the relationship between planned schedules and delay propagation is a requisite precursor to developing tools for building more robust airline plans. This relationship is investigated using the flight data provided by two major US carriers, one traditional huband-spoke and one low-fare carrier operating a predominantly point-to-point network.

The tumor microenvironment (TME) comprises distinct cell types, including stromal types such as fibroblast cells and macrophage cells, which have recently become a critical factor in tumor development and progression. Here, we identified the TME-related gene, plexin domain containing 2 (PLXDC2), in a high-stromal-score population. And we revealed that this gene was related to poor survival and advanced (tumor-node-metastasis) stage in gastric cancer (GC) patients from The Cancer Genome Atlas database. An integrated gene profile and functional analysis of the proportions of tumor-infiltrating immune cells revealed that the expression of the M2 macrophages cell marker CD163 was positively correlated with PLXDC2 expression. In addition, the M2 macrophages gene signature and high PLXDC2 expression were associated with the inflammatory signaling pathway and the epithelial-to-mesenchymal transition (EMT)-related gene signature. Single-cell study of GC identified PLXDC2 was enriched specifically in fibroblasts and monocytes/macrophages populations, which supported its important role in the stroma. Furthermore, according to a tissue microarray immunohistochemistry analysis, the expression of PLXDC2 elevated in human GC stromal specimens compared to tumor tissue specimens. Moreover, PLXDC2 overexpression in the stromal compartment was associated with CD163-positive regulatory M2 macrophages, and its functions were related to the pathogenesis of GC. Multiplexed immunohistochemistry verified PLXDC2’s correlation with EMT markers. Our data suggested that PLXDC2 was expressed in stromal cells and that its crosstalk with tumor-associated macrophages could contribute to cancer biology by inducing the EMT process.

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In the past 3 decades, the cartilage repair potential of mesenchymal stromal cells, or mesenchymal stem cells (MSCs), has been widely examined in animal studies. Unfortunately, the phenotype and physical properties of MSC-derived cartilage tissue are not comparable to native hyaline cartilage. In particular, chondrocytic hypertrophy, a phenotype that is not observed in healthy hyaline cartilage, is concomitant with MSC chondrogenesis. Given that hypertrophic chondrocytes potentially undergo apoptosis or convert into osteoblasts, this undesired phenotype needs to be prevented or minimized before MSCs can be used to repair cartilage injuries in the clinic. In this review, we first provide an overview of chondrocytic hypertrophy and briefly summarize current methods for suppressing hypertrophy in MSC-derived cartilage. We then highlight recent progress on modulating the canonical Wnt/β-catenin pathway for inhibiting hypertrophy. Specially, we discuss the potential crosstalk between Wnt/β-catenin with other pathways in regulating hypertrophy. Lastly, we explore future perspectives to further understand the role of Wnt/β-catenin in chondrocytic hypertrophy.

With rapid progress in cancer diagnosis and treatment in the last two decades, outcomes in oncological patients have improved significantly. However, the incidence of acute kidney injury (AKI) in this population has also increased significantly. AKI complicates many aspects of patients' care and adversely affects their prognoses; thus, accurately diagnosing the risk factors for AKI ensures appropriate management. AKI may be caused by pre-renal, intrinsic renal, and post-renal reasons, as well as for combined reasons. This review summarizes the potential etiologies of AKI according to the three classifications. For each underlying cause of AKI, the cancer itself and/or cancer treatment may contribute to a patient developing AKI. Therefore, we present disease-and treatment-related factors for each cause category, with special focus on immune checkpoint inhibitors, which are being used increasingly more often. It is important for nephrology services to be knowledgeable to provide the best level of care.

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