黄河流域城市群土地利用变化与生态风险评价

选取黄河流域5个国家级城市群作为研究对象,结合6种土地利用类型回溯1990~2020年的土地利用变化,并采用生态风险指数分析评价区域生态风险及其演化特征.研究发现,过去30年在城市群地区,除耕地外草地减少最为明显,分别减少了16778km^(2)和7976km^(2),低风险区面积总体占比增加了7.1%且高风险区面积占比基本稳定,生态风险总体状况呈向好态势;但是,几字弯都市圈的高风险区占比增加约5%且相较其它城市群面积最大,作为兰西城市群核心的兰州市高风险区进一步扩大,中原和山东半岛城市群过去10年均有新的中高风险区出现.对此,建议制定并完善黄河流域城市群国土空间差异化管控对策,针对已存在和潜在高风险区开展土地利用和生态风险协同管控,同时进一步加强耕地、草地、林地等的保护和修复.

Diagnostic value of 5 serum biomarkers for hepatocellular carcinoma with different epidemiological backgrounds:A large-scale,retrospective study

Objective:Hepatocellular carcinoma(HCC)is a lethal global disease that requires an accurate diagnosis.We assessed the potential of 5 serum biomarkers(AFP,AFU,GGT-II,GPC3,and HGF)in the diagnosis of HCC.Methods:In this retrospective study,we measured the serum levels of each biomarker using ELISAs in 921 participants,including 298 patients with HCC,154 patients with chronic hepatitis(CH),122 patients with liver cirrhosis(LC),and 347 healthy controls from 3 hospitals.Patients negative for hepatitis B surface antigen and hepatitis C antibody(called"NBNC-HCC")and patients positive for the above indices(called"HBV-HCC and HCV-HCC")were enrolled.The selected diagnostic model was constructed using a training cohort(n=468),and a validation cohort(n=453)was used to validate our results.Receiver operating characteristic analysis was used to evaluate the diagnostic accuracy.Results:Theα-L-fucosidase(AFU)/α-fetoprotein(AFP)combination was best able to distinguish NBNC-HCC[area under the curve:0.986(95%confidence interval:0.958–0.997),sensitivity:92.6%,specificity:98.9%]from healthy controls in the test cohort.For screening populations at risk of developing HCC(CH and LC),the AFP/AFU combination improved the diagnostic specificity for early-stage HCC[area under the curve:0.776(0.712–0.831),sensitivity:52.5%,specificity:91.6%in the test group].In all-stage HBV-HCC and HCV-HCC,AFU was also the best candidate biomarker combined with AFP[area under the curve:0.835(0.784–0.877),sensitivity 69.1%,specificity:87.4%in the test group].All results were verified in the validation group.Conclusions:The AFP/AFU combination could be used to identify NBNC-HCC from healthy controls and hepatitis-related HCC from at-risk patients.

Adsorption equilibrium, kinetics, and dynamic separation of Ca2+ and Mg2+ ions from phosphoric acid–nitric acid aqueous solution by strong acid cation resin

The separation of Ca2+and Mg2+ions from phosphoric acid-nitric acid aqueous solution is very significant for the neutralization process of nitrophosphate fertilizer.This paper studied the adsorption equilibrium,kinetics,and dynamic separation of Ca2+and Mg2+ions by strong acid cation resin,and the effects of phosphoric acid and nitric acid on the adsorption process were investigated.The results reveal that the adsorption process of Ca2+and Mg2+ions in pure water on resin is in good agreement with the Langmuir isotherm model and their maximal adsorption capacities are 1.86 mmol·g-1 and 1.83 mmol·g-1,respectively.The adsorption kinetics of Ca2+and Mg2+ions on resin fits better with the pseudo-first-order model,and the adsorption equilibrium in pure water is reached within 10 min contact time,while at the present of phosphoric acid,the adsorption rate of Ca2+and Mg2+ions on resin will go down.The dynamic separation experiments demonstrate that the designed column adsorption is able to undertake the separation of metal ions from the mix acids aqueous solution,but the dynamic operation should control the flow rate of mix acid solution.Besides nitric acid solution was proved to be effective to completely regenerate the spent resin and achieve the recyclable operation of separation process.

Erratum: A Ubiquitous Thermal Conductivity Formula for Liquids, Polymer Glass, and Amorphous Solids [Chin. Phys. Lett. 37(2020) 104401]

In the Acknowledgement, the following sentence "JH and JL are supported by the National Science Foundation (Award number CBET-1943813) and the Faulty Research and Professional Development Fund at North Carolina State University" should be changed to "JH and JL are supported by the Faulty Research and Professional Development Fund at North Carolina State University".

A Ubiquitous Thermal Conductivity Formula for Liquids, Polymer Glass, and Amorphous Solids

The microscopic mechanism of thermal transport in liquids and amorphous solids has been an outstanding problem for a long time.There have been several approaches to explain the thermal conductivities in these systems,for example,Bridgman's formula for simple liquids,the concept of the minimum thermal conductivity for amorphous solids,and the thermal resistance network model for amorphous polymers.Here,we present a ubiquitous formula to calculate the thermal conductivities of liquids and amorphous solids in a unified way,and compare it with previous ones.The calculated thermal conductivities using this formula without fitting parameters are in excellent agreement with the experimental data.Our formula not only provides a detailed microscopic mechanism of heat transfer in these systems,but also resolves the discrepancies between existing formulae and experimental data.

Use of copper-cysteamine nanoparticles to simultaneously enable radiotherapy,oxidative therapy and immunotherapy for melanoma treatment

Dear Editor,Melanoma,squamous cell carcinoma(SCC),and basal cell carcinoma(BCC)are three major types of skin cancer.Among them,melanoma is the most severe form and accounts for~4%of all newly diagnosed cancers annually in the United States.It is estimated that approximately 9500 people are diagnosed with skin cancer every day,and more than 1 million Americans are living with melanoma.Melanoma treatment is still a major challenge in the clinic.Photodynamic therapy(PDT)is composed of targeted ablation and immune activation,is less invasive than other therapies and has been widely used in the treatment of various cancers.

半导体光催化分解水的析氢效率研究

光催化水制氢是太阳能向氢能转化的有效途径,在清洁能源利用方面具有较大的潜力。光催化产氢过程主要包括光生电子和空穴对的产生、迁移以及在表面活性位点的氧化还原反应,在此过程中由于电子-空穴对的复合以及催化剂的结构和表面活性位点的局限,导致电子和空穴不能完全迁移到催化剂表面并参与氧化还原反应,从而降低了析氢效率。因此本文以抑制光生电子-空穴对复合及增加表面活性位点为目的,从调控催化剂微观特性和外在属性两方面入手,分析总结了目前常见的半导体催化剂粒径、形貌、晶面、表面活性位点调控手段以及异质结构建和助催化剂负载的方法,探究了上述因素对催化剂析氢效率的影响途径和方式,从中归纳出提升析氢效率的办法。最后对光催化制氢的未来研究方向进行了展望,希望以此为光催化产氢效率的提高提供借鉴。

Increased circulating level of interleukin-6 and CD8+T cell exhaustion are associated with progression of COVID-19

Background: Coronavirus disease 2019(COVID-19)is pandemic.It is critical to identify COVID-19 patients who are most likely to develop a severe disease.This study was designed to determine the clinical and epidemiological features of COVID-19 patients associated with the development of pneumonia and factors associated with disease progression.Methods:: Seventy consecutive patients with etiologically confirmed COVID-19 admitted to PLA General Hospital in Beijing,China from December 27,2019 to March 12,2020 were enrolled in this study and followed-up to March 16,2020.Differences in clinical and laboratory findings between COVID-19 patients with pneumonia and those without were determined by theχ2 test or the Fisher exact test(categorical variables)and independent group t test or Mann–Whitney U test(continuous variables).The Cox proportional hazard model and Generalized Estimating Equations were applied to evaluate factors that predicted the progression of COVID-19.Results: The mean incubation was 8.67(95%confidence interval,6.78–10.56)days.Mean duration from the first test severe acute respiratory syndrome coronavirus 2-positive to conversion was 11.38(9.86–12.90)days.Compared to pneumonia-free patients,pneumonia patients were 16.5 years older and had higher frequencies of having hypertension,fever,and cough and higher circulating levels of neutrophil proportion,interleukin-6,low count(<190/µl)of CD8+T cells,and neutrophil/lymphocyte ratio.Thirteen patients deteriorated during hospitalization.Cox regression analysis indicated that older age and higher serum levels of interleukin-6,C-reactive protein,procalcitonin,and lactate at admission significantly predicted the progression of COVID-19.During hospitalization,circulating counts of T lymphocytes,CD4+T cells,and CD8+T cells were lower,whereas neutrophil proportion,neutrophil/lymphocyte ratio,and the circulating levels of interleukin-6,C-reactive protein,and procalcitonin were higher,in pneumonia patients than in pneumonia-free patients.CD8+lymphocyte count in pneumonia patients did not recover when discharged.Conclusions: Older age and higher levels of C-reactive protein,procalcitionin,interleukin-6,and lactate might predict COVID-19 progression.T lymphocyte,especially CD8+cell-mediated immunity is critical in recovery of COVID-19.This study may help in predicting disease progression and designing immunotherapy for COVID-19.

Thermal transport in organic/inorganic composites

Composite materials, which consist of organic and inorganic components, are widely used in various fields because of their excellent mechanical properties, resistance to corrosion, low-cost fabrication, etc. Thermal properties of organic/inorganic composites play a crucial role in some applications such as thermal interface materials for micro-electronic packaging, nano-porous materials for sensor development, thermal insulators for aerospace, and high-performance thermoelectric materials for power generation and refrigeration. In the past few years, many studies have been conducted to reveal the physical mechanism of thermal transport in organic/ inorganic composite materials in order to stimulate their practical applications. In this paper, the theoretical and experimental progresses in this field are reviewed. Besides, main factors affecting the thermal conductivity of organic/ inorganic compositcs are discussed, including the intrinsic properties of organic matrix and inorganic fillers, topolo- gical structure of composites, loading volume fraction, and the interfacial thermal resistance between fillers and organic matrix.

Evaluation of the prognostic ability of serum uric acid for elderly acute coronary syndrome patients with diabetes mellitus:a prospective cohort study

Objective:This study evaluated the prognostic power of serum uric acid(UA)in predicting adverse events in elderly acute coronary syndrome(ACS)patients with diabetes mellitus(DM).Methods:The analysis involved 718 ACS patients>80 years old whose general clinical data and baseline blood biochemical indicators were collected prospectively from January 2006 to December 2012.These patients were classified into two groups based on DM status,and then followed up after discharge.The Kaplan-Meier method was used for major adverse cardiac event(MACE)rates and all-cause mortality.Multivariate Cox regression was performed to analyze the relationship between UA level and long-term clinical prognosis.Receiver operating characteristic(ROC)curves were analyzed to predict the cutoff value of UA in elderly ACS patients with DM.There were 242 and 476 patients in the DM and non-DM(NDM)groups,respectively,and the follow-up time after discharge was 40‒120 months(median,63 months;interquartile range,51‒74 months).Results:The all-cause mortality,cardiac mortality,and MACE rates in both DM and NDM patients were higher than those in the control group(P=0.001).All-cause mortalities,cardiac mortalities,and MACE rates in DM patients with moderate and high UA levels were significantly higher than those in the NDM group(P=0.001).Long-term survival rates decreased significantly with increased UA levels in the ACS groups(P=0.001).UA(odds ratio(OR)=2.106,95%confidence interval(CI)=1.244‒3.568,P=0.006)was found to be an independent risk factor for all-cause mortality and MACE in elderly ACS patients with DM.The cutoff value of UA was 353.6μmol/L(sensitivity,67.4%;specificity,65.7%).Conclusions:Serum UA level is a strong independent predictor of long-term all-cause death and MACE in elderly ACS patients with DM.

优化企业内控管理 助推公司服务发展

近年来,国家电网有限公司开启了建设具有卓越竞争力的世界一流能源互联网企业的新征程,要求坚持'人民电业为人民'的企业宗旨,弘扬以客户为中心、专业专注、持续改善的企业核心价值观。国网湖南电力有限公司(以下简称公司)以此为契机,强化公司营销内控管理,助推公司实现新时代战略目标。营销稽查作为强化营销管理工作中最重要一环,应该着力于关注隐患排查、服务改革发展。