多电子反应材料推动高能量密度电池发展:材料与体系创新

全球能源结构转型推动了电化学储能系统的飞速发展,提高能量密度是发展新型二次电池的重要方向和研究热点。然而,受限于传统的嵌入式反应,锂离子电池在能量密度上已经逐渐达到极限。要发展更高能量密度的新型二次电池,需要在新理论、新材料和新体系上进行突破。基于此,本文总结了20年来多电子反应材料概念的形成、理论的发展、材料创制的历程。在“轻元素多电子反应”和“多离子效应”核心设计准则的指导下,具有上述特征的电极材料与电池结构不断发展迭代,引领了高能量密度电池的发展方向。从阳离子氧化还原到阴阳离子协同氧化还原,从嵌入式反应到合金化反应,从传统有机液态体系到电池固态化,本文梳理了典型的多电子反应正负极材料的结构特性、体系创新和工程化前景,剖析了多电子反应电极材料的瓶颈问题,并分析了电池固态化发展所面临的挑战。最后,对高能量密度电池的未来发展趋势和难点进行了归纳与展望。

Logistic Regression Analysis and Nursing Interventions for High-risk Factors for Pressure Sores in Patients in a Surgical Intensive Care Unit

Objective： To investigate the risk factors related to the development of pressure sores in critically ill surgical patients and to establish a basis for the formulation of effective precautions. Methods： A questionnaire regarding the factors for pressure sores in critically ill surgical patients was created using a case control study with reference to the pertinent literature. After being exam- ined and validated by experts, the questionnaire was used to collect data about critically ill surgical patients in a grade A tertiary hospital. Among the 47 patients enrolled into the study, the 14 who developed nosocomial pressure sores were allocated to the pressure sore group, and the remaining 33 patients who met the inclusion criteria and did not exhibit pressure sores were allocated to the control group. Univariate and multivariate logistic regression analyses were employed to examine the differences in 22 indicators between the two groups in an attempt to identify the risk factors for pressure sores. Results： According to the univariate analyses, the maximum value of lactic acid in the arterial blood, the number of days of norepinephrine use, the number of days of mechanical ventilation, the number of days of blood purification, and the number of days of bowel incontinence were statistically greater in the pressure sore group than in the control group （P〈0.05）. The multivariate logistic regression analysis revealed that the number of days of norepinephrine use and the level of lactic acid in the arterial blood were high risk-factors for pressure sores （P〈0.05）. Conclusions： The best method for preventing and control pressure sores in surgical critically ill patients is to strongly emphasize the duration of the critical status and to give special attention to patients in a continuous state of shock. The adoption of measures specific to high-risk patient groups and risk factors, including the active control of primary diseases and the application of decompression measures during the treatment of the patients, are helpful for improving the quality of care in the prevention and control of pressure sores in critically ill patients.

Effect of ultrasound-guided lumbar square muscle block on stress response in patients undergoing radical gastric cancer surgery

BACKGROUND Radical surgery is a common treatment for patients with gastric cancer;however,it can lead to postoperative complications and intestinal barrier dysfunction.Ultrasound-guided quadratus lumborum block is often used for postoperative analgesia,but its effects on stress response and intestinal barrier function are not well understood.AIM To investigate the effects of an ultrasound-guided quadratus lumborum block on stress response and intestinal barrier function in patients undergoing radical surgery for gastric cancer.METHODS A total of 100 patients undergoing radical surgery for gastric cancer were randomly categorized into observation and control groups.Plasma adrenaline and cortisol levels,intestinal mucosal barrier indexes,and complication rates were compared between the two groups before,during,and 1 day after surgery.RESULTS The observation group had significantly lower plasma adrenaline and cortisol levels during surgery and at 1 day postoperatively than that of the control group(P<0.05).Additionally,intestinal barrier indexes(endotoxin and D-dimer)at 1 day postoperatively were significantly lower in the observation group than in the control group(P<0.05).CONCLUSION Ultrasound-guided quadratus lumborum block could reduce stress response,protect intestinal barrier function,and decrease the incidence of complications in patients undergoing radical surgery for gastric cancer.This technique has the potential for clinical applications.

Expression and clinical significance of PRKCD in liver hepatocellular carcinoma analyzed based on bioinformatics

Objective:To analyze the expression of protein kinase C delta(PKCδ,PRKCD)in Liver hepatocellular carcinoma and its clinical significance based on bioinformatics,in order to provide a new direction for the study of therapeutic targets for Liver hepatocellular carcinoma.Methods:The PRKCD gene expression data and patient clinical information data in Liver hepatocellular carcinoma tissues and adjacent tissues were downloaded from The TCGA(The Cancer Genome Atlas)and UCSC Xena databases.The mRNA expression of PRKCD in Liver hepatocellular carcinoma was analyzed,and the protein expression of PRKCD in Liver hepatocellular carcinoma was analyzed by Human Protein Atlas(HPA)databases.Furthermore,its relationship with clinicopathological features and prognosis in patients with Liver hepatocellular carcinoma was analyzed.GSEA enrichment analysis were carried out for PRKCD in Liver hepatocellular carcinoma.Finally,the causes of changes in PRKCD expression were analyzed from the perspective of genetic and epigenetics based on collated liver hepatocellular carcinoma data.Results:Both the mRNA and protein expression level of PRKCD gene in Liver hepatocellular carcinoma tissues was significantly higher than that in adjacent tissues.Its expression level was correlated with TNM stage,Histologic grade,Alpha fetoprotein(AFP)and Living status in clinicopathological features,and its expression level has certain clinical diagnostic accuracy.Kaplan-Meier analysis showed that the prognosis of patients with low PRKCD expression was significantly better than that with high PRKCD expression.Univariate and multivariate Cox regression analysis showed that PRKCD was an independent prognostic factor in patients with Liver hepatocellular carcinoma,and it was also found that the risk ratio of TNM stage III and stage IV survival curve(HR)was significantly greater than that of stage I and stage II.GSEA analysis showed that it was enriched in cell cycles and DNA replication,and was positively correlated with PRKCD.Enrichment analysis found that PRKCD is mainly involved in the chemokine signaling pathway,NOD-like receptor signaling pathway,PPAR signaling pathway,adipocytokine signaling pathway and T-cell receptor signaling pathway.Finally,through genetic and epigenetic analysis,it is found that the increase in the number of copies of genes will increase the expression level of PRKCD,and the methylation level is negatively correlated with the expression level of PRKCD.Conclusion:PRKCD gene is upregulated in Liver hepatocellular carcinoma tissues,and its overexpression level is closely related to patient poor prognosis.

Suspended hydrophilic carbon anodes to enable fully flowable cerium–metal hybrid flow batteries

Hybrid redox flow batteries(RFBs)are a special type of RFBs that involve depositing reactions on negative electrodes.The available volume in negative electrodes for cell stacks limits the totally energy-storing capability of these batteries.This paper introduces the first fully flowable Ce–metal flow battery operated with a semisolid,flowable anolyte.Using the semisolid fuel cell concept,we incorporate the sustainable and deposit-abundant features of non-Li-based batteries into the structure of RFBs to develop a fully flowable RFB system.Solid suspension electrodes of hydrophilic carbon particles deposited by earth-abundant metals with redox activity are investigated as alternatives to the redox-active molecules employed in typical RFBs to decouple the power delivery capability from the energy storage capacity in fully flowable RFBs.While being charged,earth-abundant redox-active metal(Cu,Pb or Zn)is electrodeposited on the carbon particle suspension,which is dissolved in the sequent discharging process.On the basis of the proposed contact-charge-transfer mechanism,the electrical contact to the solid suspension electrode is fed by the redox-inert hydrophobic current collector that restrains direct metal deposition on their surfaces due to the hydrophobicity.

Interfacial amplification for graphene-based position-sensitive-detectors

Position-sensitive-detectors(PSDs)based on lateral photoeffect have been widely used in diverse applications1–9,including optical engineering,aerospace and military fields.With increasing demand in long distance,low energy consumption,and weak signal sensing systems,the poor responsivity of conventional PSDs has become a bottleneck limiting their applications,for example,silicon p–n or p–i–n junctions2–5,or other materials and architectures6–10.Herein,we present a high-performance graphene-based PSDs with revolutionary interfacial amplification mechanism.Signal amplification in the order of~10^(4) has been demonstrated by utilizing the ultrahigh mobility of graphene and long lifetime of photo-induced carriers at the interface of SiO_(2)/Si.This would improve the detection limit of Si-based PSDs fromμW to nW level,without sacrificing the spatial resolution and response speed.Such interfacial amplification mechanism is compatible with current Si technology and can be easily extended to other sensing systems11,12.

Surface engineering based on in situ electro-polymerization to boost the initial Coulombic efficiency of hard carbon anode for sodium-ion battery

Hard carbon(HC) is considered as a commercial candidate for anode materials of sodium-ion batteries due to its low cost and excellent capacity. However, the problem of low initial Coulombic efficiency is still urgently needed to be solved to promote the industrialization of HC.In this paper, 2,2-dimethylvinyl boric acid(DEBA) is used to modify the surface of HC to prepare HC-DEBA materials. During the cycling, the C = C bonds of DEBA molecules will be in situ electro-polymerized to form a polymer network, which can act as the passive protecting layer to inhibit irreversible decomposition of electrolyte,and induce a thinner solid electrolyte interface with lower interface impedance. Therefore, HC-DEBA has higher initial Coulombic efficiency and better cycling stability. In ester-based electrolyte, the initial Coulombic efficiency of the optimized HC-DEBA-3% increases from 65.2% to77.2%. After 2000 cycles at 1 A·g^(-1), the capacity retention rate is 90.92%. Moreover, it can provide a high reversible capacity of 294.7 m Ah·g^(-1) at 50 mA·g^(-1). This simple surface modification method is ingenious and versatile,which can be extended to other energy storage materials.

Study on General Governing Equations of Computational Heat Transfer and Fluid Flow

The governing equations for heat transfer and fluid flow are often formulated in a general formfor the simplification of discretization and programming,which has achieved great success in thermal science and engineering.Based on the analysis of the popular general form of governing equations,we found that energy conservation cannot be guaranteed when specific heat capacity is not constant,which may lead to unreliable results.A new concept of generalized density is put forward,based on which a new general form of governing equations is proposed to guarantee energy conservation.A number of calculation examples have been employed to verify validation and feasibility.