A homogeneous and mechanically stable artificial diffusion layer using rigid-flexible hybrid polymer for high-performance lithium metal batteries

Artificial solid electrolyte interphase(SEI) is promising to inhibit uncontrollable lithium dendrites and enable long cycling stability for lithium metal batteries. However, the essential mechanical stability is limited since organic layers generally have low modulus whereas intrinsic brittleness for inorganic ones remains a great concern. Polymer-based SEIs with rigid and flexible chains in adequate mechanical properties are supposed to address this issue. Herein, a homogeneous and mechanically stable diffusion layer is achieved by blending rigid chains of polyphenylene sulfone(PPSU) with flexible chains of poly(vinylidene fluoride)(PVDF) in a hybrid membrane, enabling uniform diffusion and stabilizing the lithium metal anode. The Li||Cu cell with the protected electrode exhibits a long lifetime more than 450 cycles(0.5 m A cm^(-2), 1.0 m A h cm^(-2))(fourfold longer than the control group) with higher average Coulombic efficiency of 98.7%. Enhanced performances are also observed at Li||Li and full cell configurations. The improved performances are attributed to the controlled morphology and stable interphase, according to scanning electron microscopy(SEM) and electrochemical impedance. This research advances the idea of uniform lithium plating and provides a new insight on how to create a homogeneous and mechanically stable diffusion layer using rigid-flexible polymers.

Antibody Levels and Infection Status of Pertussis in the Population under Pertussis Resurgence in Guangxi in 2018:A Cross-Sectional Survey

Objective Pertussis cases have increased markedly since 2018 in Guangxi.The aim of this study was to evaluate antibody levels and the infection status of pertussis in the resident population.Method A total of 10,215 serum samples from residents were collected from August-November 2018 and tested for anti-pertussis IgG and toxin IgG using the enzyme-linked immunosorbent assay(ELISA).Results Of the collected samples,1,833(17.94%)tested positive for anti-pertussis IgG,with the median concentration of 16.06 IU/mL.Antibody level<10 IU/mL accounted for more than 60%in children under 4 years of age,but declined with age,whereas the percentages of the other three levels(10-40,40-50,and≥50 IU/mL)increased almost with age(P<0.001).Moreover,7,924 samples were selected for anti-pertussis toxin IgG,of which 653(8.24%)tested positive(≥40 IU/mL)with the median concentration of 5.89 IU/mL,and 204 participants(2.56%)had recent pertussis infection(≥100 IU/mL).Among the different age groups,the highest rates of positivity and recent infection were observed at 11-20 years of age,the lowest positivity rate at 5 years of age,and the lowest recent infection rate at 4 years of age(P<0.001,P=0.005,respectively).Conclusion The survey results showed that all age groups in Guangxi lacked immunity against pertussis,which was one of the main factors contributing to the resurgence of pertussis in 2018.In addition,the prevalence of pertussis is relatively high in Guangxi,and its incidence is seriously underestimated,especially in adolescents and adults.

PIM-1 as an artificial solid electrolyte interphase for stable lithium metal anode in high-performance batteries

Lithium metal anode is a promising electrode with high theoretical specific capacity and low electrode potential.However,its unstable interface and low Coulombic efficiency,resulting from the dendritic growth of lithium,limits its commercial application.PIM-1(PIM:polymer of intrinsic microporosity),which is a polymer with abundant micropores,exhibits high rigidity and flexibility with contorted spirocenters in the backbone,and is an ideal candidate for artificial solid electrolyte interphases(SEI).In this work,a PIM-1 membrane was synthesized and fabricated as a protective membrane on the surface of an electrode to facilitate the uniform flux of Li ions and act as a stable interface for the lithium plating/stripping process.Nodule-like lithium with rounded edges was observed under the PIM-1 membrane.The Li@PIM-1 electrode delivered a high average Coulombic efficiency(99.7%),excellent cyclability(80%capacity retention rate after 600 cycles at 1 C),and superior rate capability(125.3 m Ah g-1 at 10 C).Electrochemical impedance spectrum(EIS)showed that the PIM-1 membrane could lower the diffusion rate of Li+significantly and change the rate-determining step from charge transfer to Li+diffusion.Thus,the PIM-1 membrane is proven to act as an artificial SEI to facilitate uniform and stable deposition of lithium,in favor of obtaining a compact and dense Li-plating pattern.This work extends the application of PIMs in the field of lithium batteries and provides ideas for the construction of artificial SEI.

Investigation of polysulfone film on high-performance anode with stabilized electrolyte/electrode interface for lithium batteries

Lithium metal has been considered to be the most promising anode material for the new generation of energy-storage system.However,challenges still stand in protecting lithium metal from spontaneous reactions with electrolytes and preventing the dendritic propagation,both of which would lead to undesirable decrease in Coulombic efficiency.Polysulfone(PSf)membrane with high rigidity and free-volume cavities of approximately 0.3 nm was employed to provide a stable interface on the surface of anodic electrode.The isotropic channels were constructed by the interconnected and uniformly distributed free volumes in the polymer matrix,and were expected to be swelled by solvent molecules and anions of lithium salt and to allow Li+ions to pass through onto the electrode surface.As a result,dendrite-free morphology of deposited lithium was observed.The stabilized interface arose from the PSf film was verified by the promoted performances of Cu|Li cells and steady voltage polarization of Li|Li cells.The full cell with PSf coated anode exhibited excellent cyclability(85%capacity retention rate over 400 cycles at 1C)and an outstanding rate capability(117 m Ah g-1 at 5C).The beneficial performances were further verified by the EIS results.This work provides a new strategic idea to settle the dendritic problems of Li metal anodes.

Effect of IL-12 on the proliferation and cytotoxicity of CIK cells to gastric adenocarcinoma cell BGC-823

Objective: The aim of the study was to evaluate the effect of interleukin-12(IL-12) on the proliferation and cytotoxicity of cytokine-induced killer(CIK) cells in vitro. Methods: Three different combinations of cytokines, IL-2, IL-12 + IL-2, and IL-12, were used to proliferate CIK cells, adding IFN-γ, IL-1 and CD3 McAb in each one. Phenotype of the cells was analyzed by flow cytometry. The cellular proliferation and cytotoxic activity were determined by cytometry and MTT assay. Results: CIK cells generated by the three methods showed high reproductive activity, and no obviously difference in inducing CD3+CD56+ cells was found among the three groups. The group of IL-2 + IL-12 evidently enhanced both the proliferation and the cytotoxicity of the CIK cells compared with the other two groups(P < 0.05). Conclusion: IL-12 could be used to induce the CIK cells as well as IL-2. CIK cells induced by combining IL-12 with IL-2 had stronger proliferative ability and higher cytotoxicity to tumor cells in vitro, which could be used as a potential anti-tumor adoptive immunotherapy in clinic.

Elastic one-return boundary element method and hybrid elastic thin-slab propagator for strong-contrast media with sharp boundaries

In this paper, we developed the theory and algorithm of an elastic one-way boundary element method（BEM） and a corresponding hybrid elastic thin-slab propagator for earth media with sharp boundaries between strong contrast media. This approach can takes the advantage of accurate boundary condition of BEM and completely overcomes the weak contrast limitation of the perturbationtheory based one-way operator approach. The one-way BEM is a smooth boundary approximation, which avoids huge matrix operations in exact full BEM. In addition, the one-way BEM can model the primary-only transmitted and reflected waves and therefore is a valuable tool in elastic imaging and inversion. Through numerical tests for some simple models,we proved the validity and efficiency of the proposed method.

Intra-abdominal aortic balloon occlusion in the management of placenta percreta

Background:Massive bleeding is the main concern for the management of placenta percreta(PP).Intra-abdominal aortic balloon occlusion(IABO)is one method for pelvic devascularization,but the efficacy of IABO is uncertain.This study aims to investigate the outcomes of IABO in PP patients.Methods:We retrospectively reviewed the clinical data of PP cases from six tertiary centers in China between January 2011 and December 2015.PP cases with/without the use of IABO were analyzed.Propensity score matching analysis was performed to reduce the effect of selection bias.Postpartum hemorrhage(PPH)and the rate of hysterectomy,as well as neonatal outcomes,were analyzed.Results:One hundred and thirty-two matched pairs of patients were included in the final analysis.Compared with the control group,maternal outcomes,including PPH(68.9%vs.87.9%,χ^(2)=13.984,P<0.001),hysterectomy(8.3%vs.65.2%,χ^(2)=91.672,P<0.001),and repeated surgery(1.5%vs.12.1%,χ^(2)=11.686,P=0.001)were significantly reduced in the IABO group.For neonatal outcomes,Apgar scores at 1 minute(8.67±1.79vs.8.53±1.68,t=-0.638,P=0.947)and 5 minutes(9.43±1.55vs.9.53±1.26,t=0.566,P=0.293)were not significantly different between the two groups.Conclusions:IABO can significantly reduce blood loss,hysterectomies,and repeated surgeries.This procedure has not shown harmful effects on neonatal outcomes.

Prevalence and characteristics of macrosomia in the first and subsequent pregnancy: a multi-center retrospective study

To the Editor:Macrosomia is of growing prevalence and concern worldwide.In China,there has been a marked increase in the prevalence of macrosomia over the past few decades as a result of economic development and improvements in living standards.

Risk Factors for Gestational Diabetes Mellitus(GDM)in Subsequent Pregnancy Among Women Without GDM History in China:A Multicenter Retrospective Study

Objective:This study aimed to determine the likelihood of gestational diabetes mellitus(GDM)in subsequent pregnancy among women without GDM history and to identify risk factors for GDM in subsequent pregnancy.Methods:This retrospective cohort study involved participants who delivered twice in same hospital of 18 research centers when delivered the second baby from January 2018 to December 2018.Finally 6204 women were enrolled and 5180 women without GDM history were analyzed further.Women were categorized as non-GDM or GDM based on the blood glucose values of the subsequent pregnancy,and the characteristics and GDM risk of these groups were compared.A univariate analysis of potential risk factors was performed using the Chi-squared test and/ort-test for qualitative or quantitative variables,respectively.Associations withP values<0.1 were chosen to be included in the multivariate binary logistic regression model.Results:In primary analysis of 6204 women,the incidence of GDM in subsequent pregnancy is 48.9%(490/1002)in women with GDM history and 16.1%(835/5202)in women without GDM history.In a further analysis for 5180 women without GDM at index pregnancy,compared with the non-GDM group,the GDM group had a significantly higher age,prepregnancy body mass index,and blood glucose value at each oral glucose tolerance test(OGTT)timepoint(fasting,1 h and 2 h)during the index and subsequent pregnancies,as well as higher weight retention during the interval between the two pregnancies(P<0.001).Age above 35 years in subsequent pregnancy(odds ratio(OR)=1.540,95%confidence interval(CI)=1.257-1.886,P<0.001),macrosomia in index pregnancy(OR=1.749,95%CI=1.277-2.395,P=0.001),OGTT blood glucose values in index pregnancy(fasting,OR=2.487,95%CI=1.883-3.285,P<0.001;1 h,OR=1.142,95%CI=1.051-1.241,P=0.002;2 h,OR=1.290,95%CI=1.162-1.432,P<0.001)and weight retention(OR=1.052,95%CI=1.035-1.068,P<0.001)were independent risk factors for GDM in subsequent pregnancy.Conclusion:For women without GDM history,GDM risk factors including age,macrosomia history,OGTT value,and weight retention,these can be evaluated before a subsequent pregnancy.Early warning and interventions are needed for women at high risk.

effective treatment of post-intubation subglottic stenosis in children with holmium laser therapy and cryotherapy via flexible bronchoscopy

Importance:Post-intubation subglottic stenosis(SGS)in children can be life threatening.Definitive treatment varies and lacks a universally accepted approach.Objective:We performed a prospective study to assess the safety and feasibility of holmium laser combined with cryotherapy delivered via flexible bronchoscopy for the treatment of post-intubation SGS in children.Methods:This study involved all patients with post-intubation SGS seen at the Interventional Pulmonology Department of Beijing Children's Hospital between July 2014 and December 2016.Holmium laser treatment and cryotherapy was then performed under flexible bronchoscopy,whose parents refused to accept the alternative standard treatment of tracheotomy and balloon dilation under direct laryngoscopy.results:Sixteen patients with post-intubation SGS were included in this study.Ages ranged from 2 months to 12.25 years old.According to the Cotton-Myer grading system,three cases were Grade II,12 cases were Grade III,and one case was Grade IV.According to the McCaffrey system,eight cases were Stage 1,two cases were Stage 2,and six cases were Stage 3.The average number of procedures was 4.88.Fifteen of the 16 patients achieved clinical cure.One patient achieved clinical improvement.The average treatment course duration was 55.31 days.No severe complications were seen.Post-treatment clinical symptoms,endoscopic findings and quality of life showed marked improvement.Interpretation:Our study supports the conclusion that holmium laser treatment combined with cryotherapy via flexible bronchoscopy appears to be a safe and feasible treatment for post-intubation SGS in children.