去杠杆政策、金融资产配置与企业脱实向虚

本文使用2012-2018年A股上市公司面板数据,利用双重差分模型来检验去杠杆政策是否改变了企业金融资产配置水平。研究发现:去杠杆政策显著提高了企业金融资产持有份额,并且这种提高在民营企业的金融资产配置上尤为显著,显示更多的金融资产是配置在交易性金融资产上,说明企业有很强的动机保持自身的流动性。进一步通过调节效应检验发现,投资效率越高,企业持有金融资产就越少。我们的研究指出:去杠杆政策的效果虽然在一定程度上降低了杠杆率,但却让企业增加了金融资产的持有,刺激企业进一步“脱实向虚”;单纯的去杠杆防风险,或许并没有从长远上解决企业从实体经济抽离的问题。

Improving the WRF/urban modeling system in China by developing a national urban dataset

Accurate modeling of urban climate is essential to predict potential environmental risks in cities.Urban datasets,such as urban land use and urban canopy parameters(UCPs),are key input data for urban climate models and largely affect their performance.However,access to reliable urban datasets is a challenge,especially in fast urbanizing countries.In this study,we developed a high-resolution national urban dataset in China(NUDC)for the WRF/urban modeling system and evaluated its effect on urban climate modeling.Specifically,an optimization method based on building morphology was proposed to classify urban land use types.The key UCPs,including building height and width,street width,surface imperviousness,and anthropogenic heat flux,were calculated for both single-layer Urban Canopy Model(UCM)and multiple-layer Building Energy Parameterization(BEP).The results show that the derived morphological-based urban land use classification could better reflect the urban characteristics,compared to the socioeconomic-function-based classification.The UCPs varied largely in spatial within and across the cities.The integration of the developed urban land use and UCPs datasets significantly improved the representation of urban canopy characteristics,contributing to a more accurate modeling of near-surface air temperature,humidity,and wind in urban areas.The UCM performed better in the modeling of air temperature and humidity,while the BEP performed better in the modeling of wind speed.The newly developed NUDC can advance the study of urban climate and improve the prediction of potential urban environmental risks in China.

PRKCDBP Methylation is a Potential and Promising Candidate Biomarker for Non-small Cell Lung Cancer

Background and objectives:The occurrence and development of lung cancer are closely linked to epigenetic modification.Abnormal DNA methylation in the CpG island region of genes has been found in many cancers.Protein kinase C delta binding protein(PRKCDBP) is a potential tumor suppressor and its epigenetic changes are found in many human malignancies.This study investigated the possibility of PRKCDBP methylation as a potential biomarker for non-small cell lung cancer(NSCLC).Methods:We measured the methylation levels of PRKCDBP in the three groups of NSCLC tissues.Promoter activity was measured by the dual luciferase assay,with S’-aza-deoxycytidine to examine the effect of demethylation on the expression level of PRKCDBP.Results:The methylation levels of PRKCDBP in tumor tissues and 3 cm para-tumor were higher than those of distant(>10 cm)non-tumor tissues.Receiver operating characteristic(ROC) curve analysis between tumor tissues and distant non-tumor tissues showed that the area under the line(AUC) was 0.717.Dual luciferase experiment confirmed that the promoter region was able to promote gene expression.Meanwhile,in vitro methylation of the fragment(PRKCDBP;e) could significantly reduce the promoter activity of the fragment.Demethylation of 5’-aza-deoxycytidine in lung cancer cell lines A549 and H1299 showed a significant up-regulation of PRKCDBP mRNA levels.Conclusion:PRKCDBP methylation is a potential and promising candidate biomarker for non-small cell lung cancer.

An Imported Case and an Infected Close Contact of the Omicron Variant of SARS-CoV-2—Guangdong Province,China,December 13,2021

On November 27,2021,a 67-year-old male returning from Canada via airplane was transferred to the central isolation hotel in Shanghai.During the quarantine,his 1st,4th,7th,and 14th days of specimens returned negative for severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),which causes coronavirus disease 2019(COVID-19).On December 11,he completed 14 days of centralized isolation and returned to Guangzhou from Shanghai via airplane,then he was closed-loop transferred to Yuexiu District for a 7-day home isolation.On December 12,the local Community Health Service Center routinely collected his throat swab and the result returned to COVID-19 positive on December 13,2021.He was transported to the Guangzhou Eighth People’s Hospital for isolated treatment by negative pressure ambulance on the same day.The patient had two inflamed lungs according to the chest computed tomography(CT)examination,but his most recently updated condition was stable.An estimated 600 close contacts were identified and were placed in centralized isolation.On December 16,one of the close contacts,a 70-year-old female also tested positive for COVID-19.She lived on the lower floor of the same type of apartment as the imported case and spent 19 hours in the same building.

An Imported Case of BA.2 Lineage of Omicron Variant COVID-19—Guangdong Province,China,December 28,2021

On December 19,2021,a 31-year-old male boarded a flight from Bhubaneswar,India to Mumbai,India,and then another flight from Mumbai to Muscat,Oman.On December 24,he returned from Muscat to Guangzhou by airplane and was transferred to a centralized isolation hotel in Foshan.He was sampled on the third day of the quarantine,and the result returned to be coronavirus disease 2019(COVID-19)positive on December 27,2021.He was transported to the Guangzhou Eighth People’s Hospital for isolated treatment by negative pressure ambulance on the same day.The case had two lungs focal inflamed according to the chest CT examination.