Gamma-glutamyl transferase 5 overexpression in cerebrovascular endothelial cells improves brain pathology,cognition,and behavior in APP/PS1 mice

In patients with Alzheimer’s disease,gamma-glutamyl transferase 5(GGT5)expression has been observed to be downregulated in cerebrovascular endothelial cells.However,the functional role of GGT5 in the development of Alzheimer’s disease remains unclear.This study aimed to explore the effect of GGT5 on cognitive function and brain pathology in an APP/PS1 mouse model of Alzheimer’s disease,as well as the underlying mechanism.We observed a significant reduction in GGT5 expression in two in vitro models of Alzheimer’s disease(Aβ_(1-42)-treated hCMEC/D3 and bEnd.3 cells),as well as in the APP/PS1 mouse model.Additionally,injection of APP/PS1 mice with an adeno-associated virus encoding GGT5 enhanced hippocampal synaptic plasticity and mitigated cognitive deficits.Interestingly,increasing GGT5 expression in cerebrovascular endothelial cells reduced levels of both soluble and insoluble amyloid-βin the brains of APP/PS1 mice.This effect may be attributable to inhibition of the expression ofβ-site APP cleaving enzyme 1,which is mediated by nuclear factor-kappa B.Our findings demonstrate that GGT5 expression in cerebrovascular endothelial cells is inversely associated with Alzheimer’s disease pathogenesis,and that GGT5 upregulation mitigates cognitive deficits in APP/PS1 mice.These findings suggest that GGT5 expression in cerebrovascular endothelial cells is a potential therapeutic target and biomarker for Alzheimer’s disease.

See the color,see the seed:GmW1 as a visual reporter for transgene and genome editing in soybean

A fast and efficient recognition method of transgenic lines will greatly improve detection efficiency and reduce cost.In this study,we successfully identified the transgenic soybean plants by the color.We isolated a GmW1 gene encoding a flavonoid 3'5'-hydroxylase from a soybean cultivar ZH42(purple flower).We found that purple flowers occurred in the overexpression lines in the Jack and Williams 82 backgrounds(white flower).All plants with purple flowers were positive,and this trait seems stably inherited in the offspring.We have also obtained the editing plants,which were classified into three types according to the different flower colors appeared.We analyzed the phenotype and the homozygous types of the T_1mutants.We also found that a correspondence between flower color and stem color.This study provides a visible color reporter on soybean transformation.It can be quickly and early to identify the transgenic soybean plants by stem color of seedlings,which substantially reduces the amount of labor and cost.

The Effect of Basalt Fiber on Concrete Performance under a Sulfate Attack Environment

To enhance the sulfate attack resistance performance of concrete,Sulfate erosion test was carried out on basalt fiber concrete with different contents,selecting a concentration of 5%sulfate solution and using a dry−wet cycle mechanism attack of basalt fiber-reinforced concrete(BFRC).Every 15 dry−wet cycles,the mass,compressive strength,splitting tensile strength,and relative dynamic elastic modulus of BFRC were tested,and the SO_(4)^(2−)con-centration was measured.This work demonstrates that the mass,relative dynamic elastic modulus,compressive and splitting tensile strength of BFRC reveal a trend of climb up and then decline with the process of the dry−wet cycle.Basalt fiber can enhance the sulfate corrosion resistance of concrete by delaying the erosion of concrete induced by SO_(4)^(2−)and increasing the bearing and anti-deformation capacities of concrete by improving its inter-nal structure.Additionally,when mixing 0.2%basalt fiber into concrete,the strength deterioration rate will be reduced when the peak values of splitting tensile and compressive strength appear at 60 and 75 times the alter-nating dry−wet cycles,respectively.Adverse effects will occur when the fiber volume fraction exceeds 0.2%.The research in this paper can provide a foundation for the engineering applications of basalt fiber concrete.

Preparation of CIP@TiO_(2) composite with broadband electromagnetic wave absorption properties

Scholars aim for the improved impedance matching (Z) of materials while maintaining their excellent wave absorption properties. Based on the hydrolysis characteristics of isopropyl titanate, a simple preparation process for the coating of carbonyl iron powder(CIP) with TiO_(2) was designed. Given the TiO2coating, the Z of the CIP@TiO_(2) composite was adjusted well by decreasing the dielectric constant. Moreover, the interfacial polarization of CIP@TiO_(2) was enhanced. Ultimately, the electromagnetic-wave (EMW) absorption property of the CIP@TiO_(2)composite was improved substantially, the minimum reflection loss reached-46.07 dB, and the effective absorption bandwidth can reach 8 GHz at the composite thickness of 1.5 mm. Moreover, compared with CIP, the oxidation resistance of CIP@TiO_(2)showed remarkable improvement. The results revealed that the oxidation starting temperature of CIP@TiO_(2) as about 400℃,whereas the uncoated CIP had an oxidation starting temperature of approximately 250℃. Moreover, the largest oxidation rate temperature of CIP@TiO_(2) increased to around 550℃. This work opens up a novel strategy for the production of high-performance EMW absorbers via structural design.

Plasma metabolites and risk of myocardial infarction:a bidirectional Mendelian randomization study

BACKGROUND Myocardial infarction(MI)is a critical cardiovascular event with multifaceted etiology,involving several genetic and environmental factors.It is essential to understand the function of plasma metabolites in the development of MI and unravel its complex pathogenesis.METHODS This study employed a bidirectional Mendelian randomization(MR)approach to investigate the causal relationships between plasma metabolites and MI risk.We used genetic instruments as proxies for plasma metabolites and MI and conducted MR analyses in both directions to assess the impact of metabolites on MI risk and vice versa.In addition,the large-scale genome-wide association studies datasets was used to identify genetic variants associated with plasma metabolite(1400 metabolites)and MI(20,917 individuals with MI and 440,906 individuals without MI)susceptibility.Inverse variance weighted was the primary method for estimating causal effects.MR estimates are expressed as beta coefficients or odds ratio(OR)with 95%CI.RESULTS We identified 14 plasma metabolites associated with the occurrence of MI(P<0.05),among which 8 plasma metabolites[propionylglycine levels(OR=0.922,95%CI:0.881–0.965,P<0.001),gamma-glutamylglycine levels(OR=0.903,95%CI:0.861–0.948,P<0.001),hexadecanedioate(C16-DC)levels(OR=0.941,95%CI:0.911–0.973,P<0.001),pentose acid levels(OR=0.923,95%CI:0.877–0.972,P=0.002),X-24546 levels(OR=0.936,95%CI:0.902–0.971,P<0.001),glycine levels(OR=0.936,95%CI:0.909–0.964,P<0.001),glycine to serine ratio(OR=0.930,95%CI:0.888–0.974,P=0.002),and mannose to trans-4-hydroxyproline ratio(OR=0.912,95%CI:0.869–0.958,P<0.001)]were correlated with a decreased risk of MI,whereas the remaining 6 plasma metabolites[1-palmitoyl-2-arachidonoyl-GPE(16:0/20:4)levels(OR=1.051,95%CI:1.018–1.084,P=0.002),behenoyl dihydrosphingomyelin(d18:0/22:0)levels(OR=1.076,95%CI:1.027–1.128,P=0.002),1-stearoyl-2-docosahexaenoyl-GPE(18:0/22:6)levels(OR=1.067,95%CI:1.027–1.109,P=0.001),alpha-ketobutyrate levels(OR=1.108,95%CI:1.041–1.180,P=0.001),5-acetylamino-6-formylamino-3-methyluracil levels(OR=1.047,95%CI:1.019–1.076,P<0.001),and N-acetylputrescine to(N(1)+N(8))-acetylspermidine ratio(OR=1.045,95%CI:1.018–1.073,P<0.001)]were associated with an increased risk of MI.Furthermore,we also observed that the mentioned relationships were unaffected by horizontal pleiotropy(P>0.05).On the contrary,MI did not lead to significant alterations in the levels of the aforementioned 14 plasma metabolites(P>0.05 for each comparison).CONCLUSIONS Our bidirectional MR study identified 14 plasma metabolites associated with the occurrence of MI,among which 13 plasma metabolites have not been reported previously.These findings provide valuable insights for the early diagnosis of MI and potential therapeutic targets.

The relationship between amyloid-beta and brain capillary endothelial cells in Alzheimer's disease

Neurovascular dysfunction,as an integral part of Alzheimer's disease,may have an important influence on the onset and progression of chronic neurodegenerative processes.The bloodbrain barrier(BBB)pathway is one of the main pathways that mediates the clearance of amyloidbeta(Aβ)in the brain parenchyma.A large number of studies have shown that receptors and ATPbinding cassette transporte rs expressed on endothelial cells play an important role in Aβtransport across the BBB,but the specific mechanism is not clear.In this review,we summarize the possible mechanisms of Aβproduction and clearance,and in particular the relationship between Aβand brain capillary endothelial cells.Aβis produced by abnormal cleavage of the amyloid precursor protein via amyloidogenic processing under pathological conditions.Dys regulation of Aβclearance is considered to be the main reason for the massive accumulation of Aβin the brain parenchyma.Several pathways mediating Aβclearance from the brain into the periphery have been identified,including the BBB pathway,the blood-cerebros pinal fluid barrier and arachnoid granule pathway,and the lymphoidrelated pathway.Brain ca pilla ry endothelial cells are the key components of Aβclearance mediated by BBB.Receptors(such as LRP1,RAGE,and FcRn)and ATP-binding cassette transporters(such as P-gp,ABCA1,and ABCC1)expressed on endothelial cells play a critical role in Aβtranscytosis across the BBB.The toxic effects of Aβcan induce dysregulation of receptor and transpo rter expression on endothelial cells.Excessive Aβexerts potent detrimental cerebrovascular effects by promoting oxidative stress,inducing chronic inflammation,and impairing endothelial structure and functions.All of these are main causes for the reduction in Aβclearance across the BBB and the accumulation of Aβin the brain parenchyma.Therefo re,studies on the intera ctions between Aβand brain capillary endothelial cells,including their receptors and transporters,studies on inhibition of the toxic effects of Aβon endothelial cells,and studies on promoting the ability of endothelial cells to mediate Aβclearance may provide new therapeutic strategies for Aβclearance in Alzheimer's disease.

Association between the level of CD4^+T lymphocyte microRNA-155 and coronary artery disease in patients with unstable angina pectoris

Objective To study the association between the expression of microRNA-155(miRNA-155)in peripheral blood CD4^+T lymphocytes and the level of semrn interferon-7(IFN-7)concentration and the severity of coronary artery disease (CAD).Methods After coronary angiography,252patients with suspected unstable angina pectoris (UAP)were divided into the UAP group (128patients with CAD confirmed by angiography)and the control group (124patients without CAD confirmed by angiography).Fresh peripheral blood was extracted 16-24h before coronary angiography,CD4^+T lymphocytes was tested using immunomagnetic beads,the expression ofmiRNA-155was tested using quantitative PCR and the expression of IFN-7was tested using enzyme-linked immunosorbent assay (ELISA).According to the results of angiography,Gensini score of coronary artery lesions was analyzed.Furthermore,we also analysis the association between the level of miRNA-155in peripheral blood CD4^+T lymphocytes,the level of serum IFN-γand Gensini score of coronary lesion.Results The levels ofmiRNA-155(0.49±0.08vs.0.23±0.09)and IFN-7(227.58±26.01vs.141.23±17.89)in the UAP group were significantly higher than that of the control group,the difference was statistically significant.The level of miRNA-155and IFN-γwere positively correlated with Gensini score of CAD (r =0.534,r =0.713,respectively,all P <0.05).The level of miRNA-155was positively correlated with the level of IFN-γ,(r =0.686,P <0.05).Conclusions The level of miRNA-155in peripheral blood CD4^+T lymphocytes and the level of IFN-γ are closely correlated with the severity of CAD.

Agomelatine:a potential novel approach for the treatment of memory disorder in neurodegenerative disease

Agomelatine is a selective agonist of melatonin receptor 1A/melatonin receptor 1B(MT/MT)and antagonist of 5-hydroxytryptamine 2C receptors.It is used clinically to treat major depressive episodes in adults.The pro-chronobiological activity of agomelatine reconstructs sleep-wake rhythms and normalizes circadian disturbances via its agonistic effect of melatonin receptor 1A/melatonin receptor 1B,which work simultaneously to counteract depression and anxiety disorder.Moreover,by antagonizing neocortical postsynaptic 5-hydroxytryptamine 2C receptors,agomelatine enhances the release of dopamine and noradrenaline in the prefrontal cortex,increases the activity of dopamine and noradrenaline,and thereby reduces depression and anxiety disorder.The combination of these two effects means that agomelatine exhibits a unique pharmacological role in the treatment of depression,anxiety,and disturbance of the circadian rhythm.Emotion and sleep are closely related to memory and cognitive function.Memory disorder is defined as any forms of memory abnormality,which is typically evident in a broad range of neurodegenerative diseases,including Alzheimer’s disease.Memory impairment and cognitive impairment are common symptoms of neurodegenerative and psychiatric diseases.Therefore,whether agomelatine can improve memory and cognitive behaviors if used for alleviating depression and circadian-rhythm sleep disorders has become a research“hotspot”.This review presents the latest findings on the effects of agomelatine in the treatment of psychologic and circadian-rhythm sleep disorders in clinical trials and animal experiments.Our review evaluates recent studies on treatment of memory impairment and cognitive impairment in neurodegenerative and psychiatric diseases.

Expression of p53 in myocardium following coronary microembolization inrats and its significance

Background Cardiomyocyte apoptosis is a primary cause for coronary microembolization （CME）-induced cardiac dysfunction, p53induces cell growth retardation and apoptosis through stress pathway. The present study investigated the mechanism of p53-induced myocar-dial apoptosis and cardiac dysfunction by activating the mitochondrion apoptotic pathway following CME. Methods Forty SD rats wereequally divided into microembolization （CME）, sham operation （sham）, CME＋siRNA-p53, and CME＋control-p53 groups. The CME ratmodel was established by injecting microembolization spheres via the left ventricle. Cardiac ultrasound, TUNEL, fluorescence quantitativePCR, and Western blot were used to assess the cardiac function indicators, cardiomyocyte apoptosis, and the expressions of mRNA and pro-tein in myocardial tissues, respectively. Results Echocardiography revealed a significantly reduced cardiac function of the CME group thanthe sham group while the CME-induced cardiac dysfunction was improved in the CME＋siRNA-p53 group. The indicators of myocardialapoptosis in the CME group increased significantly than the sham group; those of the CME＋siRNA-p53 group decreased significantly thanthe CME group. Fluorescence quantitative PCR and Western blot demonstrated that p53, Bbc3 （PUMA）, and cleaved caspase-3 expressionswere significantly increased, and BCL-2 expression was declined in myocardial tissues of the CME group compared to the sham group. Acontrasting result was observed in the CME＋siRNA-p53 group as compared to the CME group. Conclusions P53 is involved in theCME-induced cardiac dysfunction, which may up-regulate Bbc3 to activate BCL-2/caspase3 mitochondrial apoptotic pathway and inducemyocardial apoptosis. Inhibiting the p53 expression can effectively suppress this pathway, thereby reducing myocardial apoptosis and car-diac dysftmction.

Nicorandil pretreatment inhibits myocardial apoptosis and improves cardiac function after coronary microembolization in rats

Background Nicorandil （NIC） is a vasodilatory drug used to treat angina. However, its efficacy of cardioprotection in coronary mi- croembolization （CME） is largely unknown. This study was undertaken to determine whether nicorandil pretreatment could attenuate myo- cardial apoptosis and improve cardiac function after CME in rats. Methods Forty-five rats were randomly divided into a Sham group, a CME group and a CME ＋ NIC （NIC） group （n = 15 per group）. CME was established by injecting plastic microspheres （42 pm in diameter） into the left ventricle of the rats in all of the groups except the Sham group. The NIC group received nicorandil at 3 mg/kg per day for seven days before the operation. Cardiac fimction was assessed by echocardiography, the expression levels of cleaved caspase-9/8/3 were detected by Western blot, microinfarction area was measured by haematoxylin-basic fuchsin picric acid staining, and myocardial apoptosis was de- tected by TUNEL staining. Results Compared to that in the Sham group, cardiac fimction in the CME group was significantly decreased （P 〈 0.05）. However, compared to the CME group, the NIC group showed improved cardiac function （P 〈 0.05）. The expression levels of cleaved caspase-9/8/3 protein and myocardial apoptosis were dramatically increased in the CME group compared to those in the Sham group （P 〈 0.05）, while the NIC pretreatment group had significantly decreased expression levels of cleaved caspase-9/8/3 protein as well as a de- creased apoptotic rate （P 〈 0.05）. Conclusions NIC pretreatment inhibited CME-induced myocardial apoptosis and improved cardiac func- tion through blockade of the mitochondrial and death receptor-mediated apoptotic pathways.

MiR-21-5p-expressing bone marrow mesenchymal stem cells alleviate myocardial ischemia/reperfusion injury by regulating the circRNA_0031672/miR-21-5p/programmed cell death protein 4 pathway

BACKGROUND For patients with coronary heart disease,reperfusion treatment strategies are often complicated by ischemia/reperfusion(I/R)injury(IRI),leading to serious organ damage and malfunction.The miR-21/programmed cell death protein 4(PDCD4)pathway is involved in the IRI of cardiomyocytes;however,the aberrant miR-21 expression remains unexplained.Therefore,this study aimed to explore whether circRNA_0031672 downregulates miR-21-5p expression during I/R and to dete-rmine whether miR-21-5p-expressing bone marrow mesenchymal stem cells(BMSCs)reduce myocardial IRI.METHODS CircRNA_0031672,miR-21-5p,and PDCD4 expressions were evaluated in the I/R rat model and hypoxia/re-oxy-genation(H/R)-treated H9C2 cells.Their interactions were subsequently investigated using luciferase reporter and RNA pull-down assays.Methyltransferase-like 3,a methyltransferase catalyzing N6-methyladenosine(m6A),was overexpressed in H9C2 cells to determine whether m6A modification influences miR-21-5p targeting PDCD4.BMSCs stably expressing miR-21 were co-cultured with H9C2 cells to investigate the protective effect of BMSCs on H9C2 cells upon H/R.RESULTS I/R downregulated miR-21-5p expression and upregulated circRNA_0031672 and PDCD4 expressions.CircRNA_0031672 knockdown increased miR-21-5p expression,but repressed PDCD4 expression,indicating that circRNA_0031672 com-petitively bound to miR-21-5p and prevented it from targeting PDCD4 mRNA.The m6A modification regulated PDCD4 expres-sion,but had no effect on miR-21-5p targeting PDCD4.The circRNA_0031672/miR-21-5p/PDCD4 axis regulated myocardial cells viability and apoptosis after H/R treatment;co-culture with miR-21-5p-expressing BMSCs restored miR-21-5p abundance in H9C2 cells and further reduced H9C2 cells apoptosis induced by H/R.CONCLUSIONS We identified a novel circRNA_0031672/miR-21-5p/PDCD4 signaling pathway that mediates the apoptosis of cardiomyocytes and successfully alleviates IRI in myocardial cells by co-culture with miR-21-5p-expressing BMSCs,offering novel insights into the IRI pathogenesis in cardiovascular diseases.

Effect of metoprolol on myocardial apoptosis after coronary microembolization in rats

BACKGROUND： Coronary microembolization （CME） is a serious complication following percutaneous coronary intervention （PCI） in patients with acute coronary syndromes. The use of metoprolol before PCI can significantly protect ischemic myocardium from myocardial damage, but the function of metoprolol in the treatment of CME is not entirely clear. This study was to explore the effect and significance of metoprolol on myocardial apoptosis and caspase-3 activation after CME in rats. METHODS： Thirty rats were randomly divided into three groups including sham-operation （control group）, CME plus saline （CME group）, CME plus metoprolol （metoprolol group）, 10 rats for each group. The CME group was induced by injecting 3 000 polyethylene microspheres （42 tJm） into the left ventricle during a 10-second occlusion of the ascending aorta; the control group was injected with physiological saline instead of microembolization ball; the metoprolol or saline group was given three intravenous bolus injections before CME. Echocardiography, TUNEL staining, and Western blotting were used to evaluate cardiac function, proportion of apoptotic cells and activation of caspase-3 respectively at 6 hours after operation. RESULTS： Echocardiographic parameters displayed that the metoprolol group improved cardiac function significantly compared with the CME group （P〈0.05）. The myocardial apoptotic rate of the CME group as well as the contents of activated caspase-3 increased significantly （P〈0.05）, both of which were ameliorated significantly by metoprolol treatment （P〈0.05）. CONCLUSIONS： This study demonstrates that metoprolol can protect the myocardium during CME in rats by inhibiting apoptosis and improving cardiac function. These results suggest that the inhibition of apoptosis can be a potential therapeutic strategy for the treatment of CME.

Lowering of Blood Lipid Levels with a Combination of Pitavastatin and Ezetimibe in Patients with Coronary Heart Disease:A Meta-Analysis

Objectives:According to the findings of randomized controlled trials,blood lipid levels in patients with coronary heart disease(CHD)can be significantly decreased through a combination of pitavastatin and ezetimibe;however,the effects and clinical applications of this treatment remain controversial.This meta-analysis was aimed at objectively assessing the efficacy and safety of pitavastatin and ezetimibe in lowering blood lipid levels.Design:Relevant studies were retrieved from electronic databases,including PubMed,Cochrane Library,Embase,China National Knowledge Infrastructure,VIP,and WanFang Data,from database inception to June 8,2022.The lev-els of low-density lipoprotein cholesterol,total cholesterol,triglycerides,and high-density lipoprotein cholesterol in patients’serum after treatment were the primary endpoint.Results:Nine randomized controlled trials(2586 patients)met the inclusion criteria.The meta-analysis indi-cated that pitavastatin plus ezetimibe resulted in significantly lower levels of LDL-C[standardized mean difference(SMD)=−0.86,95%confidence interval(CI)(−1.15 to−0.58),P<0.01],TC[SMD=−0.84,95%CI(−1.10 to−0.59),P<0.01],and TG[SMD=−0.59,95%CI(−0.89 to−0.28),P<0.01]than pitavastatin alone.Conclusions:Pitavastatin plus ezetimibe significantly decreased serum LDL-C,TC,and TG levels in patients with CHD.

STUDY OF THE MAGNETIC PROPERTIES OF LaGa_(1-x)Fe_xO_3

The dependence of the susceptibitity of LaGA_(1-x)Fe_xO_3(x=0.2,0.5, 6.8) on the concentration of Fe^(3+),teperature and magnetic fietd intensity were studied and the change of Neet point was observed. Some regularities were obtained for first time in this paper.

Experience of the national-level old Chinese medicine expert Wu Zhengshi on syndrome differentiation and treatment of anaphylactoid purpura

This paper introduced and summarized the experience of the national-level old Chinese medicine expert Wu Zhengshi on syndrome differentiation and treatment of anaphylactoid purpura.Wu Zhengshi believes that blood-heat is the main cause of anaphylactoid purpura.When Qi is weak,the human body is attacked by external heat,resulting in the damage of the blood system,which lead to the anaphylactoid purpura.The blood is thermalized poison,which enters the vessel quickly and forces the blood to overflow the vessel,which develops for the purpura.According to the ancient book of Chinese medicine Jie Wei Yuan Sou(1550 C.E.),Wu Zhengshi put forward the treatment of relieving blood detoxification,heat and cooling blood,which achieved significant curative effects.

Effect and mechanism of encapsulation on aging characteristics of quantum-dot light-emitting diodes

The aging characteristics,e.g.,the evolution of efficiency and luminance of quantum-dot light-emitting diodes(QLEDs)are greatly affected by the encapsulation.When encapsulated with ultraviolet curable resin,the efficiency is increased over time,a known phenomenon termed as positive aging which remains one of the unsolved mysteries.By developing a physical model and an analytical model,we identify that the efficiency improvement is mainly attributed to the suppression of hole leakage current that is resulted from the passivation of ZnMgO defects.When further encapsulated with desiccant,the positive aging effect vanishes.Tofully take the advantage of positive aging,the desiccant is incorporated after the positive aging process is completed.With the new encapsulation method,the QLED exhibits a high external quantum efficiency of 20.19%and a half lifetime of 1,267 h at an initial luminance of 2,800 cd·m^(-2),which are improved by 1.4 and 6.0 folds,respectively,making it one of the best performing devices.Our work provides an in-depth and systematic understanding of the mechanism of positive aging and offers a practical encapsulation way for realizing efficient and stable QLEDs.

Facile fabrication of graphene/g-C_(3)N_(4) for electromagnetic wave absorption

With the development of the miniaturization of electronic equipment and lightweight weapon equipment,there are new requirements for electromagnetic wave absorption material(EMWAM).EMWAM has outstanding electromagnetic wave absorption properties and lightweight characteristics become an important direction of research.In this study,graphene/g-C_(3)N_(4)(GGCN)EMWAM was first synthesized in situ by simple heat treatment,in which the g-C_(3)N_(4) had a porous structure and dispersed on the surface of graphene.The impedance matching of the GGCN was well adjusted by decreasing the dielectric constant and attenuation constant due to the g-C_(3)N_(4) semiconductor property and the graphite-like structure.The EMW loss mechanism of GGCN was also analyzed by simulating GGCN’s electric field mode distribution and resistance loss power density.The analysis result shows that the distribution of g-C_(3)N_(4) among GGCN sheets can produce more polarization effects and relaxation effects by increasing the lamellar spacing.Furthermore,the polarization loss of GGCN could be increased successfully by porous g-C_(3)N_(4).Ultimately,the EMW absorption property of GGCN is optimized significantly,and GGCN exhibits excellent EMW absorption performance.When the thickness is 2 mm,the effective absorption bandwidth(EAB)can reach 4.6 GHz,and when the thickness is 4.5 mm,the minimum reflection loss(RLmin)at 4.56 GHz can reach-34.69 dB.Moreover,the practical application of EMWAM was studied by radar cross-section(RCS)simulation,showing that GGCN has a good application prospect.

Silica shell-assisted synthetic route for mono-disperse persistent nanophosphors with enhanced in vivo recharged near-infrared persistent luminescence

Near-infrared （NIR） persistent-luminescence nanoparticles have emerged as a new class of background-free contrast agents that are promising for in vivo imaging. The next key roadblock is to establish a robust and controllable method for synthesizing monodisperse nanoparticles with high luminescence brightness and long persistent duration. Herein, we report a synthesis strategy involving the coating/etching of the SiO2 shell to obtain a new class of small NIR highly persistent luminescent ZnGa2O4：Cr^3＋,Sn^4＋（ZGOCS） nanoparticles. The optimized ZGOCS nanoparticles have an excellent size distribution of -15 nm without any agglomeration and an NIR persistent luminescence that is enhanced by a factor of 13.5, owing to the key role of the SiO2 shell in preventing nanoparticle agglomeration after annealing. The ZGOCS nanoparticles have a signal-to-noise ratio -3 times higher than that of previously reported ZnGa204：Cr^3＋ （ZGC-1） nanoparticles as an NIR persistent-luminescence probe for in vivo bioimaging. Moreover, the persistent-luminescence signal from the ZGOCS nanoparticles can be repeatedly re-charged in situ with external excitation by a white light- emitting diode; thus, the nanopartides are suitable for long-term in vivo imaging applications. Our study suggests an improved strategy for fabricating novel high-performance optical nanoparticles with good biocompatibility.

Effects of inhibitor KCl on shale expansibility and mechanical properties

The expansibility and mechanical properties of shale are significantly influenced by water-based muds(WBMs);thus,it is necessary to mitigate this effect to avoid borehole instabilities in drilling operation.Potassium chloride(KCl)is usually used as inhibitor to reduce hydration of shales.In this study,we investigated the inhibitory efficiency of KCl on shale through a series of experiments,including dynamic linear swelling(DLS)tests and uniaxial compressive strength(UCS)tests,to provide reference for the design of WBMs.These tests were conducted on shale samples soaked in KCl solution for 24,48,72,and 96 h with saline concentrations of 0%,2%,4%,6%,and 8%.Experimental results show that samples with microcracks and bedding fissures have the highest swelling increase and the largest strength reduction after immersion in solution.The swelling potential decreased with increasing KCl concentration.In addition,KCl exhibited a certain inhibitory effect on the weakening of the mechanical properties of samples.An increase in the KCl concentration increases the compressive strength and elastic modulus,and decreases the Poisson's ratio.However,in terms of homogeneous samples,the UCS test results show that exposure to water is weakly related to weakening of the mechanical properties of shale samples.We found that immersing the shale in KCl solution for a longer time decreases the compressive strength,increases the Poisson's ratio,and decreases the elastic modulus.

Flexible and tandem quantum-dot light-emitting diodes with individually addressable red/green/blue emission

Tandem quantum-dot light-emitting diodes(QLEDs)with multiple QLED elements vertically connected by the intermediate electrodes offer the advantages of high brightness and long lifetime.However,it is challenging to individually address each QLED element in conventional tandem structures.To address this challenge,here,transparent QLEDs built on flexible plastic substrates are developed as the building blocks for the tandem QLEDs.By vertically integrating a red,a green,and a blue transparent QLEDs with an ultraviolet glue,the resultant tandem QLED can emit separately controllable red/green/blue(R/G/B)emission with an external quantum efficiency(EQE)of 12.0%/8.5%/4.5%,respectively.Enabled by the transparent and extractable IZO electrodes,the QLED elements can also be connected in series or in parallel with an EQE of 24.8%or 8.2%,respectively.Our work provides a new implementation strategy for the realization of tandem QLEDs with individually addressable R/G/B emission for both display and lighting applications.