Hypoxia and inflammation are risk factors for acute myocardial injury in patients with coronavirus disease 2019 / 北京大学学报(医学版)

OBJECTIVE@#To investigate the risk factors for acute myocardial injury in coronavirus disease 2019 (COVID-19) patients.@*METHODS@#This is a retrospective analysis of a COVID-19 cohort, in which 149 confirmed COVID-19 patients enrolled were divided into the group of myocardial injury (19 cases) and the group of non-myocardial injury (130 cases). Myocardial injury was defined according to Fourth universal definition of myocardial infarction released by European Society of Cardiology (ESC) in 2018, that cardiac troponin (cTn) was above 99th percentile of the reference level. Clinical information and results of laboratory tests of the eligible patients were collected. Factors associated with myocardial injury in COVID-19 patients were evaluated.@*RESULTS@#Compared with the group of non-injury, the patients in the group of injury were older and had a larger proportion of severe or critical cases (P < 0.05), higher respiratory rate and lower percutaneous oxygen saturation (SpO2) without oxygen therapy on admission (P < 0.05). All inflammatory indexes except for tumor necrosis factor α (TNF-α) showed significant elevation in the patients of the group of injury (P < 0.05). Analyzed by Spearman correlation test, we showed that the levels of circulatory cTnI were in positive correlation with the levels of high-sensitivity C-reactive protein (hs-CRP), ferritin, receptor of interleukin-2 (IL-2R), interleukin-6 (IL-6) and interleukin-8 (IL-8) (ρ > 0, P < 0.05). Lower SpO2 without oxygen therapy on admission (OR: 0.860, 95%CI: 0.779-0.949, P=0.003) and higher plasma IL-6 levels (OR: 1.068, 95%CI: 1.019-1.120, P=0.006) were independent risk factors for acute myocardial injury in the patients with COVID-19 by multivariate Logistic regression analyses.@*CONCLUSION@#Hypoxic state and inflammation may play a key role in the pathogenesis of acute myocardial injury in COVID-19 patients.

Risks factors for death among COVID-19 patients combined with hypertension, coronary heart disease or diabetes / 北京大学学报(医学版)

OBJECTIVE@#The pathogenesis of myocardial injury upon corona virus disease 2019 (COVID-19) infection remain unknown,evidence of impact on outcome is insufficient, therefore, we aim to investigate the risk factors for death among COVID-19 patients combined with hypertension, coronary heart disease or diabetes in this study.@*METHODS@#This was a single-centered, retrospective, observational study. Patients of Sino-French Eco-City section of Tongji Hospital, Wuhan, China attended by Peking University Supporting Medical Team and admitted from Jan. 29, 2020 to Mar. 20, 2020 were included. The positive nucleic acid of COVID-19 virus and combination with hypertension, coronary heart disease or diabetes were in the standard. We collected the clinical data and laboratory examination results of the eligible patients to evaluate the related factors of death.@*RESULTS@#In the study, 94 COVID-19 patients enrolled were divided into the group of death (13 cases) and the group of survivors (81 cases), the average age was 66.7 years. Compared with the survival group, the death group had faster basal heart rate(103.2 beats/min vs. 88.4 beats /min, P=0.004), shortness of breath(29.0 beats /min vs. 20.0 beats /min, P<0.001), higher neutrophil count(9.2×109/L vs. 3.8×109/L, P<0.001), lower lymphocyte count(0.5×109/L vs. 1.1×109/L, P<0.001), creatine kinase MB(CK-MB, 3.2 μg/L vs. 0.8 μg/L, P<0.001), high sensitivity cardiac troponin Ⅰ(hs-cTnⅠ, 217.2 ng/L vs. 4.9 ng/L, P<0.001), N-terminal pro brain natriuretic peptide(NT-proBNP; 945.0 μg/L vs. 154.0 μg/L, P<0.001), inflammatory factor ferritin(770.2 μg/L vs. 622.8 μg/L , P=0.050), interleukin-2 recepter(IL-2R, 1 586.0 U/mL vs. 694.0 U/mL, P<0.001), interleukin-6(IL-6, 82.3 ng/L vs. 13.0 ng/L, P<0.001), interleukin-10(IL-10, 9.8 ng/L vs. 5.0 ng/L, P<0.001)were higher than those in the survival group. Univariate logistic regression analysis showed that the risk factors for death were old age, low non oxygen saturation, low lymphocyte count, myocardial injury, abnormal increase of IL 2R, IL-6, and IL-10. Multivariate regression showed that old age (OR=1.11, 95%CI=1.03-1.19, P=0.026), low non oxygen saturation(OR=0.85, 95%CI=0.72-0.99, P=0.041), and abnormal increase of IL-10(＞9.1 ng/L, OR=101.93, 95%CI=4.74-2190.71, P=0.003)were independent risk factors for COVID-19 patients combined with hypertension, coronary heart disease or diabetes.@*CONCLUSION@#In COVID-19 patients combined with hypertension, coronary heart disease or diabetes, the risk factors for death were old age, low non oxygen saturation, low lymphocyte count, myocardial injury, and abnormal increase of IL-2R, IL-6, and IL-10. Old age, low non oxygen saturation and abnormal increase of IL-10 were independent risk factors.

H2 Reduction Annealing Induced Phase Transition and Improvements on Redox Durability of Pt Cluster-Decorated Cu@Pd Electrocatalysts in Oxygen Reduction Reaction.

Hierarchical structures in shell with transition metal underneath is a promising design for high-performance and low-cost heterogeneous nanocatalysts (NCs). Such a design enables the optimum extent of synergetic effects in NC surface. It facilitates intermediate reaction steps and, therefore, boosts activity of NC in oxygen reduction reaction (ORR). In this study, carbon nanotube (CNT)-supported ternary metallic NC comprising Cucluster-in-Pdcluster nanocrystal and surface decoration of atomic Pt clusters (14 wt %) is synthesized by using the wet chemical reduction method with sequence and reaction time controls. By annealing in H2 environment (H2/N2 = 9:1, 10 sccm) at 600 K for 2 h, specific activity of Cu@Pd/Pt is substantially improved by ∼2.0-fold as compared to that of the pristine sample and commercial Pt catalysts. By cross-referencing results of electron microscopic, X-ray spectroscopic, and electrochemical analyses, we demonstrated that reduction annealing turns ternary NC into complex of Cu3Pt alloy and Cu x Pd1-x alloy. Such a transition preserves Pt and Pd in metallic phases, therefore improving the activity by ∼29% and the stability of NC in an accelerated degradation test (ADT) as compared to those of pristine Cu@Pd/Pt in 36 000 cycles at 0.85 V (vs RHE). This study presents robust H2 annealing for structure stabilization of NC and systematic characterizations for rationalization of the corresponding mechanisms. These results provide promising scenarios for facilitation of heterogeneous NC in ORR applications.

Heterogeneous Cu-Pd binary interface boosts stability and mass activity of atomic Pt clusters in the oxygen reduction reaction.

A ternary metallic CuPdPt nanocatalyst (NC) is synthesized using a wet chemical reduction method, which is sequentially designed, in the presence of acid treated carbon nanotubes. This NC is a nanocrystal with a configuration of a Cu@Pd core and atomic Pt clusters (∼9 wt%) on the top (Cu@Pd/Pt). A residual current of 92.6%, 5.2 times higher than that of commercial Pt catalysts (at 0.85 V vs. RHE), is retained after 40 000 cycles of an accelerated degradation test (ADT). Atomic and electronic structure analyses show that such exclusive stability mainly results from electron localization at Pt clusters in heterogeneous interfaces of the Cu-Pd core. Most importantly, we develop a robust ternary NC, which shows outstanding MA, superior chemical durability, and ∼90 wt% lower Pt loading than commercial Pt NCs in the oxygen reduction reaction.

Manufacture of radio frequency micromachined switches with annealing.

The fabrication and characterization of a radio frequency (RF) micromachined switch with annealing were presented. The structure of the RF switch consists of a membrane, coplanar waveguide (CPW) lines, and eight springs. The RF switch is manufactured using the complementary metal oxide semiconductor (CMOS) process. The switch requires a post-process to release the membrane and springs. The post-process uses a wet etching to remove the sacrificial silicon dioxide layer, and to obtain the suspended structures of the switch. In order to improve the residual stress of the switch, an annealing process is applied to the switch, and the membrane obtains an excellent flatness. The finite element method (FEM) software CoventorWare is utilized to simulate the stress and displacement of the RF switch. Experimental results show that the RF switch has an insertion loss of 0.9 dB at 35 GHz and an isolation of 21 dB at 39 GHz. The actuation voltage of the switch is 14 V.

Haze effect removal from image via haze density estimation in optical model.

Images/videos captured from optical devices are usually degraded by turbid media such as haze, smoke, fog, rain and snow. Haze is the most common problem in outdoor scenes because of the atmosphere conditions. This paper proposes a novel single image-based dehazing framework to remove haze artifacts from images, where we propose two novel image priors, called the pixel-based dark channel prior and the pixel-based bright channel prior. Based on the two priors with the haze optical model, we propose to estimate atmospheric light via haze density analysis. We can then estimate transmission map, followed by refining it via the bilateral filter. As a result, high-quality haze-free images can be recovered with lower computational complexity compared with the state-of-the-art approach based on patch-based dark channel prior.