EXISTENCE OF A GROUND STATE SOLUTION FOR THE CHOQUARD EQUATION WITH NONPERIODIC POTENTIALS

We study the Choquard equation-Δu+V(x)u-b(x)∫R3|u(y)|2/|x-y|dyu,x∈R3,where V(x)=V1(x),b(x)=b1(x)for x1>0 and V(x)=V2(x),b(x)=b2(x)for x1<0,and V1,V2,b1and b2are periodic in each coordinate direction.Under some suitable assumptions,we prove the existence of a ground state solution of the equation.Additionally,we find some sufficient conditions to guarantee the existence and nonexistence of a ground state solution of the equation.

Downregulation of microRNA-23a confers protection against myocardial ischemia/reperfusion injury by upregulating tissue factor pathway inhibitor 2 following luteolin pretreatment in rats

To the Editor:Myocardial ischemia/reperfusion injury(MI/RI)often causes death,dysfunction,or damage to the cardiomyocytes,and thus more effective clinical treatments are required.[1]MicroRNAs(miRNAs)bind to target mRNAs to regulate post-transcriptional gene expression,with important effects on MI/RI by regulating critical molecular signaling pathways.

SENP2-mediated SERCA2a deSUMOylation increases calcium overload in cardiomyocytes to aggravate myocardial ischemia/reperfusion injury

Background:Sarcoplasmic reticulum calcium ATPase 2a(SERCA2a)is a key protein that maintains myocardial Ca2+homeostasis.The present study aimed to investigate the mechanism underlying the SERCA2a-SUMOylation(small ubiquitinlike modifier)process after ischemia/reperfusion injury(I/RI)in vitro and in vivo.Methods:Calcium transient and systolic/diastolic function of cardiomyocytes isolated from Serca2a knockout(KO)and wildtype mice with I/RI were compared.SUMO-relevant protein expression and localization were detected by quantitative real-time PCR(RT-qPCR),Western blotting,and immunofluorescence in vitro and in vivo.Serca2a-SUMOylation,infarct size,and cardiac function of Senp1 or Senp2 overexpressed/suppressed adenovirus infected cardiomyocytes,were detected by immunoprecipitation,triphenyltetrazolium chloride(TTC)-Evans blue staining,and echocardiography respectively.Results:The results showed that the changes of Fura-2 fluorescence intensity and contraction amplitude of cardiomyocytes decreased in the I/RI groups and were further reduced in the Serca2a KO+I/RI groups.Senp1 and Senp2 messenger ribose nucleic acid(mRNA)and protein expression levels in vivo and in cardiomyocytes were highest at 6 h and declined at 12 h after I/RI.However,the highest levels in HL-1 cells were recorded at 12 h.Senp2 expression increased in the cytoplasm,unlike that of Senp1.Inhibition of Senp2 protein reversed the I/RI-induced Serca2a-SUMOylation decline,reduced the infarction area,and improved cardiac function,while inhibition of Senp1 protein could not restore the above indicators.Conclusion:I/RI activated Senp1 and Senp2 protein expression,which promoted Serca2a-deSUMOylation,while inhibition of Senp2 expression reversed Serca2a-SUMOylation and improved cardiac function.

Hf-doped ZnO transistor with high bias stability and high field-effect mobility by modulation of oxygen vacancies and interfaces

ZnO-based thin film transistors(TFTs)with high bias stability are challenging due to the intrinsic defects and overhigh interface trap density.In this work,we fabricated Hf-doped ZnO films with different cycle ratio of Zn/Hf via atomic layer deposition and subsequent annealing treatment.The results show that the cycle ratio of Zn/Hf is optimized to be 10:1,and the corresponding atomic ratio is 2.24%.The threshold voltage and subthreshold swing of the devices are improved as the annealing temperature increases,owning to the decrease of the oxygen vacancies and interface trap density.Furthermore,we developed Hf-doped ZnO TFT with high bias stability by introducing HfO_(2)intermediate layer between the active layer and SiO_(2)dielectric layer,and the shift of threshold voltage is as low as-0.273 V,showing high bias stability.Also,the device has the high field-effective mobility of 52.4 cm^(2)/Vs,low subthreshold swing of 0.68 V/dec and high Ion/Ioff of 3.6×10^(8).The results indicate a promising fabrication method for highperformance ZnO-based TFTs,which may be applied in logic circuits,radio frequency identification and so on.

Facial amphiphilicity index correlating chemical structures with antimicrobial efficacy

Facial amphiphilicity is an extraordinary chemical structure feature of a variety of antimicrobial peptides and polymers.Vast efforts have been dedicated to small molecular,macromolecular and dendrimer-like systems to mimic this highly preferred structure or conformation,including local facial amphiphilicity and global amphiphilicity.This work conceptualizes Facial Amphiphilicity Index(FAI)as a numerical value to quantitatively characterize the measure of chemical compositions and structural features in dictating antimicrobial efficacy.FAI is a ratio of numbers of charges to rings,representing both compositions of hydrophilicity and hydrophobicity.Cationic derivatives of multicyclic compounds were evaluated as model systems for testing antimicrobial selectivity against Gram-negative and Gram-positive bacteria.Both monocyclic and bicyclic compounds are non-antimicrobial regardless of FAIs.Antimicrobial efficacy was observed with systems having larger cross-sectional areas including tricyclic abietic acid and tetracyclic bile acid.While low and high FAIs respectively lead to higher and lower antimicrobial efficacy,in consideration of cytotoxicity,the sweet spot is typically suited with intermediate FAIs for each specific system.This can be well explained by the synergistic hydrophobic-hydrophobic and electrostatic interactions with bacterial cell membranes and the difference between bacterial and mammalian cell membranes.The adoption of FAI would pave a new avenue toward the design of next-generation antimicrobial macromolecules and peptides.

Nuclear Aurora kinase A switches m^(6)A reader YTHDC1 to enhance an oncogenic RNA splicing of tumor suppressor RBM4

Aberrant RNA splicing produces alternative isoforms of genes to facilitate tumor progression,yet how this process is regulated by oncogenic signal remains largely unknown.Here,we unveil that non-canonical activation of nuclear AURKA promotes an oncogenic RNA splicing of tumor suppressor RBM4 directed by m^(6)A reader YTHDC1 in lung cancer.Nuclear translocation of AURKA is a prerequisite for RNA aberrant splicing,specifically triggering RBM4 splicing from the full isoform(RBM4-FL)to the short isoform(RBM4-S)in a kinase-independent manner.

Identification of sources,characteristics and photochemical transformations of dissolved organic matter with EEM-PARAFAC in the Wei River of China

Dissolved organic matter(DOM)in rivers is a critical regulator of the cycling and toxicity of pollutants and the behavior of DOM is a key indicator for the health of the environment.We investigated the sources and characteristics of DOM in surface water and sediment samples of the Wei River,China.Dissolved organic carbon(DOC)concentration and ultraviolet absorbance at 254 nm(UV254)increased in the surface water and were decreased in the sediment downstream,indicating that the source of DOM in the water differed from the sediment.Parallel factor(PARAFAC)analysis of the excitation-emission matrices(EEM)revealed the presence of terrestrial humus-like,microbial humus-like and tryptophan-like proteins in the surface water,whereas the sediment contained UVA humic-like,UVC humic-like and fulvic-like in the sediment.The DOM in the surface water and sediment were mainly derived from microbial metabolic activity and the surrounding soil.Surface water DOM displayed greater photodegradation potential than sediment DOM.PARAFAC analysis indicated that the terrestrial humic-like substance in the water and the fulvic-like component in the sediment decomposed more rapidly.These data describe the characteristics of DOM in the Wei River and are crucial to understanding the fluctuations in environmental patterns.

VO_2(B) Nanosheets as a Cathode Material for Li-ion Battery

VO2（B） nanosheets were prepared by a liquid-phase exfoliation from VO2（B） bulk.The lithium storage properties of VO2（B） nanosheets as capacity cathode materials for rechargeable lithium secondary batteries were investigated.It was found that the nanosheets with the thickness of several nanometers and width of tens of nanometer had a preferential growth direction along[001]orientation.By comparing with VO2（B） bulk,the VO2（B） nanosheets showed a higher initial discharge capacity and a slower capacity fading rate.The reasons for these phenomena were discussed and analyzed.

Application of fresh frozen plasma transfusion in the management of excessive warfarin-associated anticoagulation

Warfarin is a commonly used oral anticoagulant.Patients with artificial valve replacement,atrial fibrillation,pulmonary embolism,deep vein thrombosis,and other diseases require long-term anticoagulant oral treatment with warfarin.As warfarin exhibits prompt action with long maintenance time,it has become a key drug for the treatment of patients at risk of developing thrombosis or thromboembolism.Warfarin is a bican coumarin anticoagulant,that exhibits competitive action against vitamin K as its mechanism of action,thereby inhibiting the synthesis of coagulation factors—predominantly the vitamin K-dependent coagulation factors II,VII,IX,and X—in hepatocytes.Long-term warfarin is known to significantly increase the risk of organ bleeding in some patients,while some patients may need to reverse the anticoagulation effect.For instance,patients scheduled for emergency or invasive surgery may require rapid anticoagulation reversal.During such medical circumstances,fresh frozen plasma(FFP)is clinically used for the reversal of excess warfarin-associated anticoagulation,as it contains all the coagulation factors that can alleviate the abnormal blood anticoagulation status in such patients.Accordingly,this article aims to perform an in-depth review of relevant literature on the reversal of warfarin with FFP,and insightful deliberation of the application and efficacy of this clinical intervention.