Mitigating volume expansion of silicon-based anode through interfacial engineering based on intermittent discharge strategy

Silicon is considered to be one of the most promising anode materials for lithium-ion batteries(LIBs),but its application is limited by the large volume expansion during alloying and dealloying.The constructing of a high-performance solid electrolyte interface(SEI) film on the surface of the anode material is considered to be one of the effective strategies to mitigate volume expansion of silicon-based anode.In this study,an intermittent discharge strategy which helps to improve the utilization efficiency of electrolyte additive of lithium difluorobisoxalate phosphate(LiDFBOP) is proposed to construct a highly conductive and dense SEI film.The results of electrochemical and physical characterization and theoretical calculations show that the intermittent discharge in the voltage range from open circuit voltage(OCV) to 1.8 V facilitates the diffusion of the soluble products,creates the conditions for the repeated direct contact between Si@C anode and LiDFBOP additive,increases the decomposition of LiDFBOP additive,and thus produces a uniform,dense and inorganics-rich(Li_(2)C_(2)O_(4),LiF and Li_(x)PO_yF_z) SEI film.Subsequently,this SEI film helps to ensure the even intercalation/de-intercalation of Li^(+) in the SEI film and the homogeneous diffusion of Li^(+) inside the Si particles,decreasing the internal stresses and anisotropic phase transitions,maintaining the integrity of Si particles,inhibiting the volume expansion and thu s improving the electrochemical performance of cells.This study not only improves the utilization efficiency of expensive additives through a simply and low-cost method,but also enriches the strategy to improve the electrochemical performance of Si@C anode through interfacial engineering.

Mechanism of high-concentration electrolyte inhibiting the destructive effect of Mn(Ⅱ)on the performance of lithium-ion batteries

By optimizing electrolyte formulation to inhibit the deposition of transition metal ions(TMIs) on the surface of the graphite anode is an effective way to improve the electrochemical performance of lithium-ion batteries.At present,it is generally believed the formation of an effective interfacial film on the surface of the anode electrode is the leading factor in reducing the dissolution of TMIs and prevent TMIs from being embedded in the electrode.It ignores the influence of the solvation structures in the electrolyte system with different composition,and is not conducive to the design of the electrolyte formulation from the perspective of changing the concentration and the preferred solvent to inhibit the degradation of battery performance caused by TMIs deposition.In this work,by analyzing the special solvation structures of the high-concentra tion electrolyte,we study the main reason why high-concentration electrolyte inhibits the destructive effect of Mn(Ⅱ) on the electrochemical performance of LIBs.By combining the potentialresolved in-situ electrochemical impedance spectroscopy technology(PRIs-EIS) and density functional theory(DFT) calculation,we find that Mn(Ⅱ) mainly exists in the form of contact ions pairs(CIPs) and aggregates(AGGs) in high-concentration electrolyte.These solvation structures can reduce the destructive effect of Mn(Ⅱ) on battery performance from two aspects:on the one hand,it can rise the lowest unoccupied orbital(LUMO) value of the solvation structures of Mn(Ⅱ),thereby reducing the chance of its reduction;on the other hand,the decrease of Mn2+ions reduction can reduce the deposition of metallic manganese in the solid electrolyte interphase(SEI),thereby avoiding the continuous growth of the SEI.This study can be provided inspiration for the design of electrolytes to inhibit the destructive effect of TMls on LIBs.

RuO_(2)-PdO nanowire networks with rich interfaces and defects supported on carbon toward the efficient alkaline hydrogen oxidation reaction

Interfacial engineering is a promising approach for enhancing electrochemical performance,but rich and efficient interfacial active sites remain a challenge in fabrication.Herein,RuO_(2)-PdO heterostructure nanowire networks(NWs) with rich interfaces and defects supported on carbon(RuO_(2)-PdO NWs/C) for alkaline hydrogen oxidation reaction(HOR) was formed by a seed induction-oriented attachment-thermal treatment method for the first time.As expected,the RuO_(2)-PdO NWs/C(72.8% Ru atomic content in metal) exhibits an excellent activity in alkaline HOR with a mass specific exchange current density(jo,m) of 1061 A gRuPd-1,which is 3.1 times of commercial Pt/C and better than most of the reported nonPt noble metal HOR electrocatalysts.Even at the high potential(~0.5 V vs.RHE) or the presence of CO(5 vol%),the RuO_(2)-PdO NWs/C still effectively catalyzes the alkaline HOR.Structure/electrochemical analysis and theoretical calculations reveal that the interfaces between RuO_(2) and PdO act as the active sites.The electronic interactions between the two species and the rich defects for the interfacial active sites weaken the adsorption of Had,also strengthen the adsorption of OHad,and accelerate the alkaline HOR process.Moreover,OHadon RuO_(2) can spillover to the interfaces,keeping the RuO_(2)-PdO NWs/C with the stable current density at higher potential and high resistance to CO poisoning.

The reduction of tea quality caused by irrational phosphate application is associated with anthocyanin metabolism

Phosphorus(P)is the second most limiting nutrient for plant growth.Previous studies suggested that P substantially affects the yield and quality of tea by affecting root growth,the decomposition and metabolism of minerals and metabolites in plants.Thus,the environmental pollution and degradation of crop quality caused by irrational fertilization is of increasing interest for researchers worldwide.To understand the effects of P fertilization on tea quality and metabolism of key quality components,three P fertilization levels(excessive,appropriate,and deficient application)were applied to tea plants using pot experiments.Content of P,potassium,polyphenols,amino acids and anthocyanins in the leaves or soil were quantified.The sensory quality of tea infusion was reduced under irrational(excessive or deficient)P fertilization.Under P deficiency,the total content of polyphenols and anthocyanins in the leaves were strongly increased compared with those of the control.A high soil P content(excessive)inhibited polyphenol accumulation,but induced the accumulation of certain anthocyanins,such as peonidin-3-Osambubioside-5-O-glucoside and peonidin-3-O-5-O-(6-O-p-coumaryl)-diglucoside.These results suggest that the reduction of tea quality caused by irrational P application is associated with anthocyanin metabolism,which provides a scientific basis for improving P fertilization strategies in tea plantations.

Enhanced charge transport in 2D inorganic molecular crystals constructed with charge-delocalized molecules

Outstanding charge transport in molecular crystals is of great importance in modern electronics and optoelectronics.The widely adopted strategies to enhance charge transport,such as restraining intermolecular vibration,are mostly limited to organic molecules,which are nearly inoperative in 2D inor-ganic molecular crystals currently.In this contribution,charge transport in 2D inorganic molecular crystals is improved by integrating charge-delocalized Se8 rings as building blocks,where the delocalized electrons on Se8 rings lift the intermolecular orbitals overlap,offering efficient charge transfer channels.Besides,α-Se flakes composed of charge-delocalized Se8 rings possess small exciton binding energy.Benefitting from these,α-Se flake exhibits excellent photodetection performance with an ultrafast response rate(�5μs)and a high detectivity of 1.08�1011 Jones.These findings contribute to a deeper under-standing of the charge transport of 2D inorganic molecular crystals composed of electron-delocalized inorganic molecules and pave the way for their poten-tial application in optoelectronics.

外泌体提取方法及在肺癌早期诊断中的作用研究进展

肺癌是世界范围内发病率和死亡率较高的恶性肿瘤之一,严重威胁着国民的生命安全与健康。肺癌的早期诊断是肺癌预防和治疗过程中的关键环节,对肺癌进行早期诊断有利于提高患者的生存率。外泌体(exosomes)与肿瘤的侵袭与转移过程密切相关,在肺癌的发生发展过程中,外泌体发挥着重要的调控作用。近年来,以外泌体为载体的生物标记物成为肺癌强有力的诊断工具。外泌体是一种由细胞分泌的由膜包裹的大小均一、直径约为30 nm-200 nm的脂质双分子层结构小囊泡。外泌体的内容物包含不同类型的核酸和蛋白质,这些核酸和蛋白质来源于其亲本细胞(包括亲本癌细胞),具有广泛的生理功能,包括参与免疫调节、细胞间联络等。外泌体中的生物大分子物质,如单链RNA、长非编码RNA、微小RNA(microRNA,miRNA)、蛋白质以及脂类,可以为肺癌的早期临床诊断提供有价值的信息。因此,本文就外泌体的来源、结构特点、提取方法、生物学特性和在肺癌早期诊断中的作用研究进展做简要阐述。

Solution-processed top-contact electrodes strategy for organic crystalline field-effect transistor arrays

Organic crystals,especially ultra-thin two-dimensional(2D)ones such as monolayer molecular crystals,are fragile and vulnerable to traditional vacuum deposition.Up to now,most of the methods reported for fabricating organic field-effect transistors(OFETs)with top-electrodes on the 2D molecular crystals are based on mechanical-transfer method.Nondestructive method for large scale in-situ electrode deposition is urgent.In this work,the silver mirror reaction(SMR)is introduced to construct top-contact electrodes on 2D organic crystalline thin films.OFETs based on bilayer crystalline films with solution-processed silver electrodes show comparable performance to devices with transferred gold electrodes.In addition to that,OFETs with SMR fabricated silver electrodes show lower contact resistance than the ones with evaporated silver electrodes.Furthermore,the temperature under which SMR electrodes annealed is relatively low(60℃),making this approach applicable to varies of organic semiconductors,such as spin-coated polymer films,vacuum evaporated films,2D and even monolayer crystalline films.Besides,OFETs with sub-micrometer channel width and 25μm channel length are realized which might find practical application in the ultra-small pixel mini/micro-LEDs.

A novel cancer vaccine with the ability to simultaneously produce anti-PD-1 antibody and GM-CSF in cancer cells and enhance Th1-biased antitumor immunity

Tumor escape from immune-mediated destruction has been associated with immunosuppressive mechanisms that inhibit T-cell activation.A promising strategy for cancer immunotherapy is to disrupt key pathways regulating immune tolerance,such as program death-1(PD-1/PD-L1)pathway in the tumor environment.However,the determinants of response to anti-PD-1 monoclonal antibodies(mAbs)treatment remain incompletely understood.In murine models,PD-1 blockade alone fails to induce effective immune responses to poorly immunogenic tumors,but is successful when combined with additional interventions,such as cancer vaccines.Novel cancer vaccines combined with antibody may offer promising control of cancer development and progression.In this investigation,we generated a novel tumor cell vaccine simultaneously expressing anti-PD-1 mAbs and granulocyte-macrophage colony stimulating factor(GM-CSF)in CT26 colon cancer and B16-F10 melanoma.The antitumor effect of the vaccine was verified by therapeutic and adoptive animal experiments in vivo.The antitumor mechanism was analyzed using Flow cytometry,Elispot and in vivo intervention approaches.The results showed that tumor cell vaccine secreting PD-1 neutralizing antibodies and GM-CSF induced remarkable antitumor immune effects and prolonged the survival of tumor-bearing animals compared with animals treated with either PD-1 mAbs or GM-CSF alone.Antitumor effects and prolonged survival correlated with strong antigen-specific T-cell responses by analyzing CD11c^(+)CD86^(+)DC,CD11b^(+)F4/80^(+)MΦcells,increased ratio of Teff/Treg in the tumor microenvironment,and higher secretion levels of Th1 proinflammatory cytokines in serum.Furthermore,the results of ELISPOT and in vivo blocking strategies further confirmed that the antitumor immune response is acquired by CD4 and CD8 T immune responses,primarily dependent on CD4 Th1 immune response,not NK innate immune response.The combination of PD-1 blockade with GM-CSF secretion potency creates a novel tumor cell vaccine immunotherapy,affording significantly improved antitumor responses by releasing the state of immunosuppressive microenvironment and augmenting the tumor-reactive T-cell responses.

Few-layered organic single-crystalline heterojunctions for high-performance phototransistors

Photogating and electrical gating are key physical mechanisms in organic phototransistors(OPTs).However,most OPTs are based on thick and polycrystalline films,which leads to substantially low efficiency of both photogating and electrical gating and thus reduced photoresponse.Herein,high-performance OPTs based on few-layered organic single-crystalline heterojunctions are proposed and the obstacle of thick and polycrystalline films for photodetection is overcome.Because of the molecular scale thickness of the type I organic single-crystalline heterojunctions in OPTs,both photogating and electrical gating are highly efficient.By synergy of efficient photogating and electrical gating,key figures of merit of OPTs reach the highest among those based on planar heterojunctions so far as we know.The production of few-layered organic single-crystalline heterojunctions will provide a new type of advanced materials for various applications.

Author Correction: A novel cancer vaccine with the ability to simultaneously produce anti-PD-1 antibody and GM-CSF in cancer cells and enhance Th1-biased antitumor immunity

Correction to:Signal Transduction and Targeted Therapy(2016)1:16025 https://doi.org/10.1038/sigtrans.2016.25,published online 18 November 2016 Since the publication of this research Article,we retrospected the paper and noticed two inadvertent mistakes that need to be corrected immediately.We have checked the original data and repeated the experiments;the correct data are provided in this Corrigendum as follows.The key findings of the article are not affected by these corrections.

Advantages of nasogastric tube feeding during neoadjuvant concurrent chemoradiotherapy for esophageal cancer:A retrospective study

ObjectiveTo compare the effects of oral intake and nasogastric tube(NG)feeding on nutritional status,complications and survival during neoadjuvant chemoradiotherapy for esophageal squamous-cell carcinoma(ESCC)patients.MethodsA total of 61 ESCC cases treated with neoadjuvant chemoradiotherapy from December 2018 to March 2020 were enrolled,including(38 in oral intake group,and 22 in NG feeding group.Disease characteristics and baseline nutritional markers were collected in both groups.Nutritional status,complication and completion rate of chemoradiotherapy in both groups were evaluated.ResultsCompared with the oral intake group,patients in the NG feeding group had a later T stage(P=0.027)and clinical stage(P=0.014).The levels of energy intake(P=0.033),serum prealbumin(P<0.001),albumin(P=0.017)and hemoglobin(P=0.015)before treatment in NG group were significantly lower than those in oral intake group.Furthermore,patient-generated subjective global assessment(PG-SGA)score(P=0.016)and the levels of serum C-reactive protein(P=0.014)of NG feeding group were significantly higher than those of oral intake group.However,at the end of treatment,PG-SGA scores were increased in oral intake group and decreased in NG feeding group.In addition,the NG feeding group had a lower incidence of grade≥2 esophagitis(P=0.037),and higher completion rate of chemotherapy compared with oral intake group(P=0.034).Meanwhile,the proportion of parenteral nutrition(P=0.008)and anti-inflammatory(P=0.022)treatment in NG feeding group was significantly lower than that in oral intake group.Although patients in the NG feeding group had a worse prognosis,there were no statistically significant differences in overall survival(OS)and progression-free survival(PFS)between the two groups(P>0.05).ConclusionsAs a safe and effective enteral nutrition approach to improving nutrition,nasogastric tube feeding could increase treatment completion rate and reduce the incidence of≥grade 2 esophagitis reaction during neoadjuvant chemoradiotherapy.

Rush-hour aromatic and chlorinated hydrocarbons in selected subway stations of Shanghai,China

Air samples were collected simultaneously at platform,mezzanine and outdoor in five typical stations of subway system in Shanghai,China using stainless steel canisters and analyzed by gas chromatography-mass selective detector （GC-MSD） after cryogenic pre-concentration.Benzene,toluene,ethylbenzene and xylenes （BTEX） at the platforms and mezzanines inside the stations averaged （10.3±2.1）,（38.7±9.0）,（19.4±10.1） and （30.0±11.1） μg/m 3,respectively;while trichloroethylene （TrCE）,tetrachloroethylene （TeCE） and para-dichlorobenzene （pDCB）,vinyl chloride and carbon tetrachloride were the most abundant chlorinated hydrocarbons inside the stations with average levels of （3.6±1.3）,（1.3±0.5）,（4.1±1.1）,（2.2±1.1） and （1.2±0.3） μg/m 3,respectively.Mean levels of major aromatic and chlorinated hydrocarbons were higher indoor （platforms and mezzanines） than outdoor with average indoor/outdoor （I/O） ratios of 1.1–9.5,whereas no significant indoor/outdoor differences were found except for benzene and TrCE.The highly significant mutual correlations （p0.01） for BTEX between indoor and outdoor and their significant correlation （p0.05） with methyl tert-butyl ether （MTBE）,a marker of traffic-related emission without other indoor and outdoor sources,indicated that BTEX were introduced into the subway stations from indoor/outdoor air exchange and traffic emission should be their dominant source.TrCE and pDCB were mainly from indoor emission and TeCE might have both indoor emission sources and contribution from outdoor air,especially in the mezzanines.