Hollow Gradient-Structured Iron-Anchored Carbon Nanospheres for Enhanced Electromagnetic Wave Absorption

In the present paper,a microwave absorber with nanoscale gradient structure was proposed for enhancing the electromagnetic absorption performance.The inorganic-organic competitive coating strategy was employed,which can effectively adjust the thermodynamic and kinetic reactions of iron ions during the solvothermal process.As a result,Fe nanoparticles can be gradually decreased from the inner side to the surface across the hollow carbon shell.The results reveal that it offers an outstanding reflection loss value in combination with broadband wave absorption and flexible adjustment ability,which is superior to other relative graded distribution structures and satisfied with the requirements of lightweight equipment.In addition,this work elucidates the intrinsic microwave regulation mechanism of the multiscale hybrid electromagnetic wave absorber.The excellent impedance matching and moderate dielectric parameters are exhibited to be the dominative factors for the promotion of microwave absorption performance of the optimized materials.This strategy to prepare gradient-distributed microwave absorbing materials initiates a new way for designing and fabricating wave absorber with excellent impedance matching property in practical applications.

Application Research of Medical Imaging Practical Teaching Based on Virtual Simulation Teaching Platform

Objective:To explore the application effect of virtual simulation teaching platform in the practical teaching of medical imaging.Methods:A total of 97 students majoring in medical imaging technology of class 2022 were selected and divided into two groups according to the random number method:control group(n=48)and observation group(n=49).The observation group was under the practical teaching mode based on the virtual simulation teaching platform,while the control group was under the traditional multimedia teaching mode.Questionnaire survey and teaching assessment were carried out after the teaching period,and the application effects of the two teaching modes were compared.Results:The reading and theoretical scores of the students in the observation group were significantly higher than those of the students in the control group(P<0.01);there were statistically significant differences in the results of the questionnaire survey(improved learning interest,improved language expression,improved ability to comprehensively analyze problems,and improved teamwork awareness)between the two groups of students(P<0.05);the students in the observation group were markedly more satisfied with the teaching content,teaching methods,and teaching quality than the students in the control group(P<0.05).Conclusion:The medical imaging practical teaching mode based on virtual simulation platform not only helps improve students’theoretical understanding and practical ability in medical imaging technology,but also improves students’learning interest,language expression ability,ability to comprehensively analyze problems,communication skills,teamwork awareness,and satisfaction with the teaching content,teaching methods,and teaching quality.Therefore,it has wide application value in medical specialty education.

Experiment Combined with Picture Archiving and Communication System in the Practical Teaching of Medical Imaging

Objective:To explore the application effect of virtual simulation experiment combined with picture archiving and communication system(PACS)in medical imaging practical teaching.Methods:97 students from the medical imaging class of 2022 were divided into two groups;the control group(n=48)was taught by the traditional teaching method,whereas the research group was taught by virtual simulation experiment combined with PACS(n=49).The teaching achievements and teaching effects of the two groups were compared to define the advantages of the two teaching modes.Results:Initially,there were no significant differences in the basic theory,image analysis,report writing,and differential diagnosis scores between the two groups of students(P>0.05);however,after 16 weeks of teaching,the scores of the research group were better than those of the control group(P<0.05);the pass rate of students in the study group(93.88%)was higher than that in the control group(81.25%);the scores of students in the research group in terms of clinical inquiry skills,X-ray/computed tomography/magnetic resonance imaging(X-ray/CT/MRI)operation skills,and doctor-patient communication skills were significantly higher than those in the control group(P<0.05).Conclusion:In medical imaging practical teaching,the application of virtual simulation experiment combined with PACS can effectively address several problems in the traditional teaching mode,including the single teaching method,the single teaching content,and the lack of innovation,and,at the same time,improve students’basic theoretical knowledge,X-ray/CT/MRI operation skills,consultation skills,and doctor-patient communication skills,thereby effectively improving the teaching quality and learning effect.

Immunoglobulin superfamily containing leucine-rich repeat(ISLR)negatively regulates osteogenic differentiation through the BMP-Smad signaling pathway

Osteoporosis(OP)is an aging-associated condition that significantly affects the quality of life in aging humans and has few treatment options.As an important marker,recombinant immunoglobulin superfamily containing leucinerich repeat(ISLR)could be used as a gene therapy for OP.We herein used alkaline phosphatase(ALP)and alizarin red S(ARS)staining to evaluate osteogenic differentiation potential.

Hepatic HDAC3 Regulates Systemic Iron Homeostasis and Ferroptosis via the Hippo Signaling Pathway

Histone deacetylases(HDACs)are epigenetic regulators that play an important role in determining cell fate and maintaining cellular homeostasis.However,whether and how HDACs regulate iron metabolism and ferroptosis(an iron-dependent form of cell death)remain unclear.Here,the putative role of hepatic HDACs in regulating iron metabolism and ferroptosis was investigated using genetic mouse models.Mice lacking Hdac3 expression in the liver(Hdac3-LKO mice)have significantly reduced hepatic Hamp mRNA(encoding the peptide hormone hepcidin)and altered iron homeostasis.Transcription profiling of Hdac3-LKO mice suggests that the Hippo signaling pathway may be downstream of Hdac3.Moreover,using a Hippo pathway inhibitor and overexpressing the transcriptional regulator Yap(Yes-associated protein)significantly reduced Hamp mRNA levels.Using a promoter reporter assay,we then identified 2 Yap-binding repressor sites within the human HAMP promoter region.We also found that inhibiting Hdac3 led to increased translocation of Yap to the nucleus,suggesting activation of Yap.Notably,knock-in mice expressing a constitutively active form of Yap(Yap K342M)phenocopied the altered hepcidin levels observed in Hdac3-LKO mice.Mechanistically,we show that iron-overload-induced ferroptosis underlies the liver injury that develops in Hdac3-LKO mice,and knocking down Yap expression in Hdac3-LKO mice reduces both iron-overload-and ferroptosis-induced liver injury.These results provide compelling evidence supporting the notion that HDAC3 regulates iron homeostasis via the Hippo/Yap pathway and may serve as a target for reducing ferroptosis in iron-overload-related diseases.

基于新型扫频光源生物测量仪测量的全角膜屈光力和传统角膜屈光力计算IOL度数的准确性比较

目的:比较基于新型扫频光源生物测量仪测量的全角膜屈光力(TK)和传统角膜屈光力(K)计算人工晶状体(IOL)度数的准确性。方法:前瞻性自身对照研究。收集2021年5—11月在北京大学人民医院眼科因双眼年龄相关性白内障行白内障超声乳化联合衍射型三焦点IOL植入术的患者29例(58眼)。使用IOLMaster 700扫频光学生物测量仪进行术前眼轴长度、前房深度、中央角膜厚度、晶状体厚度、前后表面角膜屈光力、TK、白到白角膜直径的测量。分别使用K和TK按照目前常用IOL度数计算公式(SRK/T、Haigis、Holladay2及Barrett UniversalⅡ)及额外新增加的Barrett TK UniversalⅡ公式计算IOL度数及预测屈光度数。术后1、3个月进行最佳矫正远视力检查及主觉验光。计算绝对预测误差、绝对预测误差均值、绝对预测误差中位数(MedAE)及各个公式预测误差值在±0.25、±0.50、±0.75、±1.00 D内所占的百分比。采用Wilcoxon符号秩和检验和McNemar’’s卡方检验进行数据分析。结果:TK值和K值的差异平均值(TK-K)为0.007 D,二者之间的组内相关系数为0.996(P<0.001),提示二者之间有良好的一致性。在Haigis和Barrett UniversalⅡ公式,使用TK值计算的MedAE略小于K值计算的MedAE;在SRK/T和Holladay2公式,使用K值计算的MedAE略小于TK值计算的MedAE。Barrett TK UniversalⅡ比Barrett UniversalⅡ公式预测误差值在±0.25、±0.50 D内所占的百分比略高,而SRK/T、Haigis及Holladay2公式K值计算比TK值计算预测误差值在±0.25、±0.50 D内所占的百分比略高,差异均没有统计学意义。结论:基于新型扫频光源生物测量仪测量的TK值在不同IOL度数计算公式中的IOL度数计算的准确性与K值一致,利用TK值在Barrett TK UniversalⅡ公式的计算准确性更高。

The zinc transporter Slc39a5 controls glucose sensing and insulin secretion in pancreatic β-cells via Sirt1- and Pgc-1α-mediated regulation of Glut2

Zinc levels are high in pancreatic β-cells, and zinc is involved in the synthesis, processing and secretion of insulin in these cells. However, precisely how cellular zinc homeostasis is regulated in pancreatic β-cells is poorly understood. By screening the expression of 14 Slc39a metal importer family member genes, we found that the zinc transporter Slc39a5 is significantly downregulated in pancreatic β-cells in diabetic db/db mice, obese ob/ob mice and high-fat diet-fed mice. Moreover,β-cell-specific Slc39a5 knockout mice have impaired insulin secretion. In addition, Slc39a5-deficient pancreatic islets have reduced glucose tolerance accompanied by reduced expression of Pgc-1α and its downstream target gene Glut2. The down-regulation of Glut2 in Slc39a5-deficient islets was rescued using agonists of Sirt1, Pgc-1α and Ppar-γ. At the mechanistic level, we found that Slc39a5-mediated zinc influx induces Glut2 expression via Sirt1-mediated Pgc-1α activation. These findings suggest that Slc39a5 may serve as a possible therapeutic target for diabetes-related conditions.

Fast Zn^(2+)mobility enabled by sucrose modified Zn^(2+)solvation structure for dendrite-free aqueous zinc battery

Aqueous zinc battery has been regarded as one of the most promising energy storage systems due to its low cost and environmental benignity.However,the safety concern on Zn anodes caused by uncontrolled Zn dendrite growth in aqueous electrolyte hinders their application.Herein,sucrose with multi-hydroxyl groups has been introduced into aqueous electrolyte to modify Zn^(2+)solvation environment and create a protection layer on Zn anode,thus effectively retarding the growth of zinc dendrites.Atomistic simulations and experiments confirm that sucrose molecules can enter into the solvation sheath of Zn^(2+),and the as-formed unique solvation structure enhances the mobility of Zn^(2+).Such fast Zn^(2+)kinetics in sucrose-modified electrolyte can successfully suppress the dendrite growth.With this sucrose-modified aqueous electrolyte,Zn/Zn symmetric cells present more stable cycle performance than those using pure aqueous electrolyte;Zn/C cells also deliver an impressive higher energy density of 129.7 Wh·kg^(−1)and improved stability,suggesting a great potential application of sucrose-modified electrolytes for future Zn batteries.

Nanomedicine sheds new light on cancer immunotherapy

Cancer immunotherapy comprising of immune checkpoint blockade(ICB)therapy,immune cell therapies,cancer vaccines and many others represents a profound arsenal in the fight against different types of cancers.However,their overall clinical objective response rates,particularly against most solid tumors,are still not sufficient owing to a variety of reasons including the heterogenous expression of tumor antigens,limited tumor infiltration of effector immune cells,acquired tumor immunosuppression and some other factors.In recent years,various nanomedicine strategies have been proposed to assist cancer immunotherapy via distinct mechanisms,presenting new promises in many published studies.This perspective will thus provide a brief overview regarding the development of nanomedicine platforms for improving cancer immunotherapy.

Characterization of ferroptosis-triggered pyroptotic signaling in heart failure

Pressure overload–induced cardiac hypertrophy is a common cause of heart failure(HF),and emerging evidence suggests that excessive oxidized lipids have a detrimental effect on cardiomyocytes.However,the key regulator of lipid toxicity in cardiomyocytes during this pathological process remains unknown.Here,we used lipidomics profiling and RNA-seq analysis and found that phosphatidylethanolamines(PEs)and Acsl4 expression are significantly increased in mice with transverse aortic constriction(TAC)–induced HF compared to sham-operated mice.In addition,we found that overexpressing Acsl4 in cardiomyocytes exacerbates pressure overload‒induced cardiac dysfunction via ferroptosis.Notably,both pharmacological inhibition and genetic deletion of Acsl4 significantly reduced left ventricular chamber size and improved cardiac function in mice with TAC-induced HF.Moreover,silencing Acsl4 expression in cultured neonatal rat ventricular myocytes was sufficient to inhibit hypertrophic stimulus‒induced cell growth.Mechanistically,we found that Acsl4-dependent ferroptosis activates the pyroptotic signaling pathway,which leads to increased production of the proinflammatory cytokine IL-1β,and neutralizing IL-1βimproved cardiac function in Acsl4 transgenic mice following TAC.These results indicate that ACSL4 plays an essential role in the heart during pressure overload‒induced cardiac remodeling via ferroptosis-induced pyroptotic signaling.Together,these findings provide compelling evidence that targeting the ACSL4-ferroptosis-pyroptotic signaling cascade may provide a promising therapeutic strategy for preventing heart failure.