160 kV,10 ns上升沿脉冲触发器的研制

为了研究医学系统中乳腺癌早期诊断的关键技术,本文研制了一台用于准点X光相位差照相系统的触发器,对触发器的输出脉冲要求:峰值电压160 kV,上升时间 ≤ 10 ns,脉宽 ≤ 100 ns。该触发器由Marx发生器、火花隙开关、电容分压器及输出段构成,其中Marx发生器采用8级同轴正负极充电的双边结构,每级由6个40 kV 3800 pF的陶瓷电容器并联组成,采用紧凑回路低电感的设计;4个火花隙开关采用跨级触发放电;在输出段末端设计了环形电容分压器作为触发器的高电压测量探头。Simplorer模拟结果表明:在实际负载阻值时,输出电压169 kV,上升时间 ≤ 10 ns,脉宽 ≤ 100 ns,满足设计指标要求。

基于FAERS数据库的胺碘酮相关呼吸系统不良事件信号挖掘研究

目的基于美国食品药品管理局不良事件报告系统对胺碘酮相关呼吸系统不良事件(ADE)进行信号挖掘,为临床安全应用胺碘酮提供参考。方法提取FAERS数据库2016年第1季度至2021年第4季度共24个季度的胺碘酮相关呼吸系统ADE报告数据,利用报告比值比法和比例报告比值法进行数据挖掘。得到有效信号后,再利用《国际医学用语词典》规范进行汉化及系统分类。结果获得与胺碘酮有关的ADE报告39166份,其中胺碘酮相关呼吸系统ADE报告6903份,有信号的首选语(PT)共71个,可分为8个高位组语(HLGT),其中呼吸系统疾病这一HLGT信号数25个,ADE报告3199份,占比最多。报告数前5位的PT依次是呼吸困难、肺纤维化、咳嗽、肺毒性、间质性肺疾病;信号强度前5位的PT依次为肺毒性、肺纤维化、纵膈出血、机化性肺炎、膈肌瘫痪。死亡事件占比前3位的PT依次是呼吸衰竭、哮鸣、急性呼吸窘迫综合征。药品说明书中未收录的PT有29个,其中纵隔出血、膈肌瘫痪、纵膈血肿等胸部疾病虽发生频次不高,但与胺碘酮的关联性较强。结论需重视胺碘酮相关呼吸系统ADE的风险,尤其是肺毒性和急性呼吸道疾病,重点关注特殊人群(老年人、儿童),男性、老年可能为高危因素,加强用药前的肺功能评估及用药中、用药后的监测,及时诊断和治疗,降低胺碘酮相关呼吸系统ADE的发生风险。

SlMYB75,an MYB-type transcription factor,promotes anthocyanin accumulation and enhances volatile aroma production in tomato fruits

Genetic manipulation of genes to upregulate specific branches of metabolic pathways is a method that is commonly used to improve fruit quality.However,the use of a single gene to impact several metabolic pathways is difficult.Here,we show that overexpression of the single gene SlMYB75(SlMYB75-OE)is effective at improving multiple fruit quality traits.In these engineered fruits,the anthocyanin content reached 1.86mg g−1 fresh weight at the red-ripe stage,and these SlMYB75-OE tomatoes displayed a series of physiological changes,including delayed ripening and increased ethylene production.In addition to anthocyanin,the total contents of phenolics,flavonoids and soluble solids in SlMYB75-OE fruits were enhanced by 2.6,4,and 1.2 times,respectively,compared to those of wild-type(WT)fruits.Interestingly,a number of aroma volatiles,such as aldehyde,phenylpropanoid-derived and terpene volatiles,were significantly increased in SlMYB75-OE fruits,with some terpene volatiles showing more than 10 times higher levels than those in WT fruits.Consistent with the metabolic assessment,transcriptomic profiling indicated that the genes involved in the ethylene signaling,phenylpropanoid and isoprenoid pathways were greatly upregulated in SlMYB75-OE fruits.Yeast one-hybrid and transactivation assays revealed that SlMYB75 is able to directly bind to the MYBPLANT and MYBPZM cis-regulatory elements and to activate the promoters of the LOXC,AADC2 and TPS genes.The identification of SlMYB75 as a key regulator of fruit quality attributes through the transcriptional regulation of downstream genes involved in several metabolic pathways opens new avenues towards engineering fruits with a higher sensory and nutritional quality.

Interaction of 14-3-3σ with KCMF1 suppresses the proliferation and colony formation of human colon cancer stem cells

AIM: To investigate the biological function of 14-3-3σ protein and to look for proteins that interact with 14-3-3σ protein in colon cancer stem cells. METHODS: Reverse transcription polymerase chain reaction was performed to amplify the 14-3-3σ gene from the mRNA of colon cancer stem cells. The gene was then cloned into the pGEM-T vector. After being sequenced, the target gene 14-3-3σ was cut from the pGEM-T vector and cloned into the pGBKT7 yeast expression plasmid. Then, the bait plasmid pGBKT7-14-3-3σ was transformed into the yeast strain AH109. After the expression of the pGBKT7-14-3-3σ fusion protein in the AH109 yeast strain was accomplished, a yeast two-hybrid screening assay was performed by mating AH109 with Y187 that contained a HeLa cDNA library plasmid. The interaction between the 14-3-3σ protein and the proteins obtained from positive colonies was further confirmed by repeating the yeast two-hybridscreen. After extracting and sequencing the plasmids from the positive colonies, we performed a bioinformatics analysis. A coimmunoprecipitation assay was performed to confirm the interaction between 14-3-3σ and the proteins obtained from the positive colonies. Finally, we constructed 14-3-3σ and potassium channel modulatory factor 1 (KCMF1) siRNA expression plasmids and transfected them into colon cancer stem cells. RESULTS: The bait plasmid pGBKT7-14-3-3σ was constructed successfully, and the 14-3-3σ protein had no toxic or autonomous activation effect on the yeast. Nineteen true-positive colonies were selected and sequenced, and their full-length sequences were obtained. We searched for homologous DNA sequences for these sequences from GenBank. Among the positive colonies, four coding genes with known functions were obtained, including KCMF1 , quinone oxidore-ductase (NQO2 ), hydroxyisobutyrate dehydrogenase (HIBADH ) and 14-3-3σ . For the subsequent coimmu-noprecipitation assay, the plasmids PCDEF-Flag-14-3-3σ, PCDEF-Myc-KCMF1, PCDEF-Myc-NQO2 and PCDEF-Myc-HIBADH were successfully constructed, and the sequences were further confirmed by DNA sequencing. The Fugene 6 reagent was used to transfect the plasmids, and fluorescence-activated cell sorting analysis showed the transfection efficiency was 97.8% after 48 h. The HEK 293FT cells showed the stable expression of the PCDEF-Flag-14-3-3σ, PCDEF-Myc-KCMF1, PCDEF-Myc-NQO2 and PCDEF-Myc-HIBADH plasmids. After anti-Myc antibody immunoprecipitation with Myc-KCMF1, Myc-NQO2 and Myc-HIBADH from cell lysates, the presence of Flag-14-3-3σ protein in the immuno-precipitated complex was determined by western blot analysis. The knock-down expression of the 14-3-3σ and KCMF1 proteins significantly inhibited cell proliferation and colony formation of SW1116csc. CONCLUSION: Genes of the proteins that interactedwith 14-3-3σ were successfully screened from a HeLa cDNA library. KCMF1 and 14-3-3σ protein may affect the proliferation and colony formation of human colon cancer stem cells.

基于网络药理学和指纹图谱的温经止痛合剂质量标准研究

目的基于网络药理学和指纹图谱,筛选温经止痛合剂质量指标成分,建立薄层鉴别和含量测定方法,为评价温经止痛合剂的质量提供依据。方法构建“温经止痛合剂饮片-主要活性成分-靶点”图,筛选用于质量控制的主要饮片和成分;采用TLC法对其进行定性分析;用HPLC法建立温经止痛合剂的指纹图谱,标定共有峰并进行相似度评价,并对确认的成分进行含量测定。结果通过温经止痛合剂“饮片-主要活性成分-靶点”图,筛选出甘草、蒲黄、吴茱萸、乌药、延胡索、赤芍为主要活性成分饮片。赤芍、吴茱萸、延胡索的TCL鉴别结果分离度好、专属性强;指纹图谱指认了5个共有峰,并以去甲异波尔定、芍药苷、甘草酸铵建立了温经止痛合剂含量测定的质量标准。结论基于网络药理学和指纹图谱,建立了TLC定性分析和HPLC含量测定方法,该法准确可靠,重复性好,可用于温经止痛合剂的质量控制。

Fish consumption and risk of gastrointestinal cancers:A meta-analysis of cohort studies

AIM: To assess quantitatively the relationship between fish intake and the incidence of gastrointestinal cancers in a meta-analysis of cohort studies.

Electrochemical detection of methyl-paraoxon based on bifunctional cerium oxide nanozyme with catalytic activity and signal amplification effect

A new electrochemical sensor for organophosphate pesticide(methyl-paraoxon)detection based on bifunctional cerium oxide(CeO_(2))nanozyme is here reported for the first time.Methyl-paraoxon was degraded into p-nitrophenol by using CeO_(2) with phosphatase mimicking activity.The CeO_(2) nanozymemodified electrode was then synthesized to detect p-nitrophenol.Cyclic voltammetry was applied to investigate the electrochemical behavior of the modified electrode,which indicates that the signal enhancement effect may attribute to the coating of CeO_(2) nanozyme.The current research also studied and discussed the main parameters affecting the analytical signal,including accumulation potential,accumulation time,and pH.Under the optimum conditions,the present method provided a wider linear range from 0.1 to 100 mmol/L for methyl-paraoxon with a detection limit of 0.06 mmol/L.To validate the proof of concept,the electrochemical sensor was then successfully applied for the determination of methyl-paraoxon in three herb samples,i.e.,Coix lacryma-jobi,Adenophora stricta and Semen nelumbinis.Our findings may provide new insights into the application of bifunctional nanozyme in electrochemical detection of organophosphorus pesticide.

Prognostic value of c-Met in colorectal cancer:A metaanalysis

AIM: To assess the prognostic value of c-Met status in colorectal cancer. METHODS: We conducted a search in Pub Med, Web of Science, and the Cochrane Library covering all published papers up to July 2014. Only studies assessing survival in colorectal cancer by c-Met status were included. This meta-analysis was performed by using STATA11.0.RESULTS: Ultimately, 11 studies were included in this analysis. Meta-analysis of the hazard ratios(HR)indicated that patients with high c-Met expression have a significantly poorer overall survival(OR)(HR = 1.33, 95%CI: 1.06-1.59) and progression-free survival(PFS)(HR = 1.47, 95%CI: 1.03-1.91). Subgroup analysis showed a significant association between high c-Met expression and poorer overall survival in the hazard ratio reported(HR = 1.41, 95%CI: 1.08-1.74).CONCLUSION: The present meta-analysis indicated that high c-Met expression was associated with poor prognosis in patients with colorectal cancer.

Bottom-up lithium growth guided by Ag concentration gradient in 3D PVDF framework towards stable lithium metal anode

Three-dimensional(3 D)frameworks have received much attention as an effective modification strategy for next-generation high-energy-density lithium metal batteries.However,the top-growth mode of lithium(Li)on the 3 D framework remains a tough challenge.To achieve a uniform bottom-up Li growth,a scheme involving Ag concentration gradient in 3 D PVDF framework(C-Ag/PVDF)is proposed.Ag nanoparticles with a concentration gradient induce an interface activity gradient in the 3 D framework,and this gradient feature is still maintained during the cycle.As a result,the C-Ag/PVDF framework delivers a long lifespan over 1800 h at a current density of 1 mA cm^(-2) with a capacity of 1 mAh cm^(-2),and shows an ultra-long life(>1300 h)even at a high current density of 4 mA cm^(-2) with a capacity of 4 mAh cm^(-2).The advantage of concentration gradient provides further insights into the optimal design of the 3 D framework for stable Li metal anode.

Taxonomy and toxin profi le of harmful benthic Prorocentrum(Dinophyceae)species from the Xisha Islands,South China Sea

Some benthic Prorocentrum can produce okadaic acid(OA)and dinophysistoxins(DTXs)that cause diarrheic shellfish poisoning(DSP)in humans.The diversity and toxin profi les(OA and DTXs)of benthic Prorocentrum were investigated in the Xisha Islands,South China Sea.The benthic Prorocentrum was identified by both morphological features and molecular phylogenies.Morphologies were examined by light,fluorescence,and scanning electron microscopy,and phylogenetic analyses were based on partial large subunit(LSU)rDNA and ITS1-5.8S-ITS2(ITS)region.Seven Prorocentrum species including P.borbonicum,P.caipirignum,P.concavum,P.elegans,P.cf.emarginatum,P.lima complex,and P.rhathymum were identified in Xisha Islands.Among them,P.borbonicum and P.elegans were recorded in Chinese waters for the first time.OA and DTXs contents of seven benthic Prorocentrum species were evaluated based on liquid chromatography-tandem mass spectrometry(LC-MS/MS).All Xisha Islands strains of P.lima complex produced OA at contents ranging from 1663 to 3816 fg/cell.P.caipirignum also generated OA at 407 fg/cell,but other five species had no detectable toxins.Besides,interestingly,two strains of P.lima complex produced DTX-1 only(74 and 183 fg/cell)and another two strains generated an isomer of OA and DTX-2.Our findings provided insight into the biodiversity of benthic Prorocentrum in the Xisha Islands and pointed out the potential risk of DSP in this area.

Ginsenoside Rk2, a dehydroprotopanaxadiol saponin, alleviates alcoholic liver disease via regulating NLRP3 and NLRP6 inflammasome signaling pathways in mice

Heavy alcohol consumption results in alcoholic liver disease(ALD)with inadequate therapeutic options.Here,we first report the potential beneficial effects of ginsenoside Rk2(Rk2),a rare dehydroprotopanaxadiol saponin isolated from streamed ginseng,against alcoholic liver injury in mice.Chronic-plus-single-binge ethanol feeding caused severe liver injury,as manifested by significantly elevated serum aminotransferase levels,hepatic histological changes,increased lipid accumulation,oxidative stress,and inflammation in the liver.These deleterious effects were alleviated by the treatment with Rk2(5 and 30 mg/kg).Acting as an nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 3(NLRP3)inhibitor,Rk2 ameliorates alcohol-induced liver inflammation by inhibiting NLRP3 inflammasome signaling in the liver.Meanwhile,the treatment with Rk2 alleviated the alcohol-induced intestinal barrier dysfunction via enhancing NLRP6 inflammasome in the intestine.Our findings indicate that Rk2 is a promising agent for the prevention and treatment of ALD and other NLPR3-driven diseases.

Biodiversity and distribution of benthic dinoflagellates in tropical Zhongsha Islands,South China Sea

Benthic dinoflagellates have attracted increasing attention in recent years because of their toxicity and ability to form extensive harmful algal blooms.Ostreopsis producing palytoxin and its analogs,Gambierdiscus producing ciguatera toxins,and Prorocentrum producing okadaic acid and dinophysis toxins,have been concerned as serious human poisonings.We explored the benthic dinoflagellate biodiversity and distribution characteristics of a series of tropical reefs in 20-40-m water depth in wet season in the Zhongsha Islands in South China Sea using morphological,phylogenetic,and cell counting methods.Results show that benthic dinoflagellates in the islands are rich in biodiversity and 15 species from genera Amphidinium,Coolia,Ostreopsis,and Prorocentrum were identifi ed:Amphidinium carterae,A.magnum,A.massartii,A.operculatum,Coolia canariensis,C.malayensis,C.palmyrensis,C.tropicalis,Ostreopsis cf.ovata,Prorocentrum concavum,P.cf.sculptile,P.emarginatum,P.hof fmannianum,P.lima,and P.rhathymum.Among them,A.magnum is reported for the first time in Chinese waters.The abundance of benthic dinoflagellates was relatively low at 88-4345 cells/100 cm^(2) on sediment and 10-91 cells/g on macroalgae.Prorocentrum and Amphidinium were the dominant and subdominant genera,respectively.It is speculated that the low abundance of benthic dinoflagellates is closely related to the scarcity of macroalgae and stronger water motion at the depth>15 m in Zhongsha Islands.This study expanded the study in biodiversity of benthic dinoflagellates in Chinese waters,and revealed the distribution characteristics of harmful benthic microalgae in reef habitats.

Effect of bio-tissue deformation behavior due to intratumoral injection on magnetic hyperthermia

Thermal damage of malignant tissue is generally determined not only by the characteristics of bio-tissues and nanoparticles but also the nanofluid concentration distributions due to different injection methods during magnetic hyperthermia.The latter has more advantages in improving the therapeutic effect with respect to the former since it is a determining factor for the uniformity of nanofluid concentration distribution inside the tumor region.This study investigates the effect of bio-tissue deformation due to intratumoral injection on the thermal damage behavior and treatment temperature distribution during magnetic hyperthermia,in which both the bio-tissue deformation due to nanofluid injection and the mass diffusion after injection behavior are taken into consideration.The nanofluid flow behavior is illustrated by two different theoretical models in this study,which are Navier–Stokes equation inside syringe needle and modified Darcy’s law inside bio-tissue.The diffusion behavior after nanofluid injection is expressed by a modified convection–diffusion equation.A proposed three-dimensional liver model based on the angiographic data is set to be the research object in this study,in which all bio-tissues are assumed to be deformable porous media.Simulation results demonstrate that the injection point for syringe needle can generally achieve the maximum value in the tissue pressure,deformation degree,and interstitial flow velocity during the injection process,all of which then drop sharply with the distance away from the injection center.In addition to the bio-tissue deformation due to injection behavior,the treatment temperature is also highly relevant to determine both the diffusion duration and blood perfusion rate due to the thermal damage during the therapy.

A meta-analysis of the effects of energy intake on risk of digestive cancers

AIM:To quantitatively assess the relationship between energy intake and the incidence of digestive cancers in a meta-analysis of cohort studies.METHODS:We searched MEDLINE,EMBASE,Science Citation Index Expanded,and the bibliographies of retrieved articles.Studies were included if they reported relative risks(RRs) and corresponding 95% CIs of digestive cancers with respect to total energy intake.When RRs were not available in the published article,they were computed from the exposure distributions.Data were extracted independently by two investigators and discrepancies were resolved by discussion with a third investigator.We performed fixed-effects meta-analyses and meta-regressions to compute the summary RR for highest versus lowest category of energy intake and for per unit energy intake and digestive cancer incidence by giving each study-specific RR a weight that was proportional to its precision.RESULTS:Nineteen studies consisting of 13 independent cohorts met the inclusion criteria.The studiesincluded 995 577 participants and 5620 incident cases of digestive cancer with an average follow-up of 11.1 years.A significant inverse association was observed between energy intake and the incidence of digestive cancers.The RR of digestive cancers for the highest compared to the lowest caloric intake category was 0.90(95% CI 0.81-0.98,P < 0.05).The RR for an increment of 239 kcal/d energy intake was 0.97(95% CI 0.95-0.99,P < 0.05) in the fixed model.In subgroup analyses,we noted that energy intake was associated with a reduced risk of colorectal cancer(RR 0.90,95% CI 0.81-0.99,P < 0.05) and an increased risk of gastric cancer(RR 1.19,95% CI 1.08-1.31,P < 0.01).There appeared to be no association with esophageal(RR 0.96,95% CI 0.86-1.07,P > 0.05) or pancreatic(RR 0.79,95% CI 0.49-1.09,P > 0.05) cancer.Associations were also similar in studies from North America and Europe.The RR was 1.02(95% CI 0.79-1.25,P > 0.05) when considering the six studies conducted in North America and 0.87(95% CI 0.77-0.98,P < 0.05) for the five studies from Europe.CONCLUSION:Our findings suggest that high energy intake may reduce the total digestive cancer incidence and has a preventive effect on colorectal cancer.

Effect of cetuximab combined with paclitaxel + cisplatin neoadjuvant chemotherapy on esophageal cancer cell proliferation and invasion

Objective:To study the effect of cetuximab combined with paclitaxel + cisplatin neoadjuvant chemotherapy on esophageal cancer cell proliferation and invasion.Methods:A total of 62 patients with esophageal cancer who were treated in the hospital between January 2015 and December 2016 were collected and divided into control group and observation group according to random number table, with 31 cases in each group. Control group of patients received paclitaxel + cisplatin neoadjuvant chemotherapy + surgery, and observation group of patients accepted cetuximab combined with paclitaxel + cisplatin neoadjuvant chemotherapy + surgery. The differences in proliferation and invasion gene expression in the tumor tissue were compared between two groups of patients before and after chemotherapy.Results:Before chemotherapy, differences in proliferation and invasion gene expression in tumor tissue were not statistically significant between two groups of patients. After chemotherapy, pro-proliferation genes FOXA1, ABCE1, USP39 and Nestin mRNA expression in tumor tissue of observation group were significantly lower than those of control group;anti-proliferation genes PETN, KLF4, TSLC1 and AnnexinA2 mRNA expression were significantly higher than those of control group;pro-invasion genesγ-synuclein, CXCR4 and Snail mRNA expression were significantly lower than those of control group;anti-invasion genes CIAPIN1, Fez and Lrig1 mRNA expression were significantly higher than that of control group.Conclusions:Cetuximab combined with paclitaxel + cisplatin neoadjuvant chemotherapy can effectively inhibit the malignant degree of esophageal cancer cells and inhibit its proliferation and invasion.

Click chemistry-based enrichment strategy for tracing cellular fatty acid metabolism by LC-MS/MS

Fatty acids(FAs),which were initially recognized as energy sources and essential building blocks of biomembranes,serve as the precursors of important signaling molecules.Tracing FA metabolism is essential to understanding the biochemical activity and role of FAs in physiological and pathological events.Inspired by the advances in click chemistry for protein enrichment,we herein established a click chemistry-based enrichment(CCBE)strategy for tracing the cellular metabolism of eicosapentaenoic acid(EPA,20:5 n-3)in neural cells.Terminal alkyne-labeled EPA(EPAA)used as a surrogate was incubated with N2a,mouse neuroblastoma cells,and alkyne-labeled metabolites(ALMs)were selectively captured by an azide-modified resin via a Cu(I)-catalyzed azide-alkyne cycloaddition reaction for enrichment.After removing unlabeled metabolites,ALMs containing a triazole moiety were cleaved from solid-phase resins and subjected to liquid chromatography mass spectrometry(LC-MS)analysis.The proposed CCBE strategy is highly selective for capturing and enriching alkyne-labeled metabolites from the complicated matrices.In addition,this method can overcome current detection limits by enhancing MS sensitivity of targets,improving the chromatographic separation of sn-position glycerophospholipid regioisomers,facilitating structural characterization of ALMs by a specific MS/MS fragmentation signature,and providing versatile fluorescence detection of ALMs for cellular distribution.This CCBE strategy might be expanded to trace the metabolism of other FAs,small molecules,or drugs.

Thermal apoptosis analysis considering injection behavior optimization and mass diffusion during magnetic hyperthermia

Thermally induced apoptosis for tumors depends mainly on the intrinsic characteristics of biological tissues as well as treatment temperature profile during magnetic hyperthermia.Further,treatment temperature distribution inside tumor depends on the injection behavior of irregular tumors,such as the injection dose and the injection location of nanofluids.In order to improve the treatment effect,the simulated annealing algorithm is adopted in this work to optimize the nanofluid injection behavior,and the improved Arrhenius model is used to evaluate the malignant ablations for three typical malignant tumor cell models.In addition,both the injection behavior optimization and the mass diffusion of nanofluid are both taken into consideration in order to improve the treatment effect.The simulation results demonstrate that the injection behavior can be optimized effectively by the proposed optimization method before therapy,the result of which can also conduce to improving the thermal apoptosis possibility for proposed typical malignant cells.Furthermore,an effective approach is also employed by considering longer diffusion duration and correct power dissipation at the same time.The results show that a better result can then be obtained than those in other cases when the power dissipation of MNPs is set to be QMNP=5.4×10^(7)W·m^(3) and the diffusion time is 16 h.

In situ formed FeS_(2)@CoS cathode for long cycling life lithium-ion battery

Pyrite FeS_(2)exhibits an ultrahigh energy density(1671 W·h·kg^(-1),for the reaction of FeS_(2)+4Li=Fe+2Li_(2)S)in secondary lithium-ion batteries,but its poor cycling stability,huge volume expansion,the shuttle effect of polysulfides,and slow kinetic properties limit its practical application.In this work,we synthesize a composite structure material CoS on FeS_(2)surface(FeSx@CoS,1<x≤2)by using a cobalt-containing MOF to improve its cycle stability.It is found that CoS inhibits the side reactions and adsorbs polysulfides.As a result,the modified FeS_(2)shows a higher discharge capacity of 577 mA·h·g^(-1)(919 W·h·kg^(-1))after 60 cycles than 484 mA·h·g^(-1)(778 W·h·kg^(-1))of bare pyrite FeS_(2).This efficient strategy provides a valuable step toward the realization of high cycling stability FeS_(2)cathode materials for secondary lithium-ion batteries and enriches the basic understanding of the influence of FeS_(2)interfacial stability on its electrochemical performances.

Recoverability analysis of block-sparse representation

Recoverability of block-sparse signals by convex relaxation methods is considered for the underdetermined linear model. In previous works, some explicit but pessimistic recoverability results which were associated with the dictionary were presented. This paper shows the recoverability of block-sparse signals are associated with the block structure when a random dictionary is given. Several probability inequalities are obtained to show how the recoverability changes along with the block structure parameters, such as the number of nonzero blocks, the block length, the dimension of the measurements and the dimension of the block-sparse representation signal. Also, this paper concludes that if the block-sparse structure can be considered, the recoverability of the signals wil be improved. Numerical examples are given to il ustrate the availability of the presented theoretical results.

FeSO_(4) as a Novel Li-Ion Battery Cathode

FeSO_(4) has the characteristics of low cost and theoretical high energy density(799 W·h·kg^(-1) with a two-electron reaction),which can meet the demand for next-generation lithium-ion batteries.Herein,FeSO_(4) as a novel highperformance conversion-reaction type cathode is investigated.We use dopamine as a carbon coating source to increase its electronic conductivity.FeSO_(4)@C demonstrates a high reversible specific capacity(512 mA·h·g^(-1))and a superior cycling performance(482 mA·h·g^(-1) after 250 cycles).In addition,we further study its reaction mechanism.The FeSO_(4) is converted to Fe and Li2SO_(4) during lithium ion insertion and the Fe-Li_(2)SO_(4) grain boundaries further store additional lithium ions.Our findings are valuable in exploring other new conversion-type lithium ion battery cathodes.