Bifunctional

双功能
  • 文章类型: Journal Article
    锂硫(Li-S)电池,被公认为最有前途的下一代储能系统之一,仍然受到可溶性多硫化物(LiPs)在阴极上的“穿梭效应”和锂枝晶在阳极上的不受控制的生长的限制。这些问题是其实际应用的关键障碍。目前,许多研究人员从单方面的角度解决了这些挑战。在这里,我们提出了基于高熵硒化物(HE-Se)的双功能宿主,以同时解决Li-S电池正极和负极上的持续问题。一方面,HE-Se与多硫化物相互作用以促进其转化,有效缓解穿梭效应。另一方面,HE-Se在Li的初始成核过程中提供了多个亲石位点,这降低了过电位,并表现出优异的亲岩性和循环稳定性。因此,包含HE-Se主体的Li-S电池在倍率能力和循环稳定性方面表现出出色的性能。此外,多孔亲石HE-Se结构提供了足够的成核位点,抑制树枝状锂的生长,并适应充电和放电循环期间的体积变化。这项研究强调了嗜硫/亲锂高熵材料在设计先进的Li-S电池中的潜力,并鼓励在这一领域进行进一步的探索。
    Lithium-sulfur (Li-S) batteries, recognized as one of the most promising next-generation energy storage systems, are still limited by the \"shuttle effect\" of soluble polysulfides (LiPSs) on the cathode and the uncontrolled growth of lithium dendrites on the anode. These issues are critical obstacles to their practical application. Currently, many researchers have addressed these challenges from a unilateral perspective. Herein, we propose bifunctional hosts based on high-entropy selenides (HE-Se) to simultaneously tackle the persistent problems on both the positive and negative electrodes of Li-S batteries. On the one hand, HE-Se interacts with polysulfides to promote their conversion, effectively mitigating the shuttle effect. On the other hand, HE-Se provides multiple lithophilic sites during the initial nucleation of Li+, which reduces overpotential and exhibits excellent lithophilicity and cyclic stability. As a result, Li-S batteries incorporating the HE-Se host demonstrate outstanding performance in terms of rate capability and cycling stability. Additionally, the porous lithophilic HE-Se structure offers sufficient nucleation sites, inhibits the growth of dendritic lithium, and accommodates volume changes during charging and discharging cycles. This study highlights the potential of sulphophilic/lithophilic high-entropy materials in designing advanced Li-S batteries and encourages further exploration in this area.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    肼(N2H4)和亚硫酸氢盐(HSO3-)的检测方法对人体健康和环境安全有害。在这里,我们报道了一种双响应荧光探针EPC,其能够通过两种不同的荧光信号顺序检测N2H4和HSO3-。探针EPC本身显示黄色荧光。在N2H4存在下,探针EPC表现出明显的荧光变化(从黄色到绿色)。然而,探针EPC与HSO3-混合后,一种新的加成产品应运而生,其次是微弱的黄色发射。更重要的是,探针EPC对N2H4和HSO3-表现出优异的荧光响应特性,例如高灵敏度(N2H4为0.182µM,HSO3为0.093µM),快速响应(N2H4为55s,HSO3-为45s),优异的选择性和抗干扰性能。通过1HNMR和MS光谱证明了N2H4和HSO3-的传感机理。对实际应用进行了研究。基于EPC的试纸可用于定量检测实际水样中的N2H4。And,EPC探针已成功用于识别土壤样品中的N2H4污染物。此外,EPC具有巨大的潜力用于检测实际食品样品中的HSO3-。
    Hydrazine (N2H4) and bisulfite (HSO3-) detection methods are urgently needed due to its harmful to the human health and environment safety. Herein, we reported a dual-response fluorescence probe EPC, which is capable of sequential detection of N2H4 and HSO3- by two different fluorescence signals. The probe EPC itself showed yellow florescence. In presence of N2H4, probe EPC exhibited an obviously fluorescence change (from yellow to green). However, a new addition product came into being after probe EPC mixed with HSO3-, followed with weak yellow emission. More important, probe EPC exhibited excellent fluorescence response properties for N2H4 and HSO3-, such as high sensitivity (0.182 µM for N2H4, 0.093 µM for HSO3-), rapid response (55 s for N2H4, 45 s for HSO3-), excellent selectivity and anti-interference performance. The sensing mechanisms for N2H4 and HSO3- were proved by 1H NMR and MS spectra. Practical applications were studied. EPC based test paper can be utilized for quantitative detecting N2H4 in actual water samples. And, probe EPC has been successfully applied to recognize N2H4 contaminant in soil samples. Moreover, EPC has great potential to be used to detect HSO3- in real food samples.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    电化学水分解(EWS)是获得H2的一种有前途的方法,由于具有可再生和生态友好的优点,H2被认为是化石燃料的理想替代品。开发基于无定形的简单且结构柔性的非贵金属催化剂以提供用于商业应用的高性能已经成为当前的兴趣。无定形钴锚定的氮掺杂的碳纳米颗粒(Co@NC-NP)被设计为具有低过电位,并将Tafel作为双功能电催化剂(HER-142mV/80mVdec-1和OER-250mV/72mVdec-1)在1.0KOH中实现10mAcm-2。FE-SEM和HR-TEM描述了Co@NC-NP电催化剂的互连纳米链形态和纯度,EDX和元素作图证实了这一点。在全电池水电解槽中,Co@NC-NP(+,-)可以充当阳极和阴极电极材料,以在宽pH值下在10mAcm-2下实现1.60V。有效的Co@NC-NP稳定100h,无明显衰退。在太阳能电池应用中,Co@NC-NP(+,-)催化剂用作正极和负极,并产生大量的O2和H2气泡。如前所述,我们涵盖了非晶化策略,具有结构灵活性和缺陷的乐观作用,以丰富活性位点以提高电催化稳定性。作为一个有希望的观点,无定形电催化剂为EWS的即将发展提供了超效率。
    Electrochemical water splitting (EWS) is a promising way to attain H2, which has been deemed an ideal substitution for fossil fuels because of renewable and eco-friendly benefits. Developing an amorphous-based simple and structurally flexible non-noble catalyst to offer high performance for commercial applications has become a current interest. Amorphous cobalt-anchored nitrogen-doped carbon nanoparticles (Co@NC-NPs) were designed to have a low overpotential and Tafel as a bifunctional electrocatalyst (HER - 142 mV/80 mV dec-1 and OER - 250 mV/72 mV dec-1) to achieve 10 mA cm-2 in 1.0 KOH. FE-SEM and HR-TEM described the interconnected nanochain morphology and purity of Co@NC-NPs electrocatalyst, which were confirmed by EDX and elemental mapping. In a full cell water electrolyzer, Co@NC-NPs(+,-) may act as an anode and cathode electrode material to achieve 1.60 V @ 10 mA cm-2 in a wide pH. The efficient Co@NC-NPs are stable for 100 h without obvious recession. In solar cell applications, Co@NC-NPs(+,-) catalyst was employed as both positive and negative terminals and evolved enormous bubbles of O2 and H2. As previously mentioned, we covered the amorphization strategy with the optimistic role of structural flexibility and defects to enrich the active sites to improve the electrocatalytic stability. As a promising opinion, the amorphous electrocatalyst provides ultraefficiency for forthcoming developments in EWS.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Preprint
    转录因子与序列基序结合并充当激活子或阻遏子。转录因子与一组辅助辅因子相互作用,以调节不同的机制步骤来调节转录。我们快速降解必需和普遍表达的转录因子ZNF143,以确定其在转录周期中的功能。ZNF143促进RNA聚合酶启动并激活基因表达。ZNF143结合几乎所有其激活的靶基因的启动子。ZNF143还在基因转录起始位点附近结合以直接抑制基因子集。尽管ZNF143刺激ZNF143抑制的基因(即在ZNF143耗尽后增加表达的基因)的启动,结合的分子背景导致顺式抑制。ZNF143与其他更有效的激活剂竞争启动子访问,物理上封闭转录起始位点和启动子近端序列元件,并在早期延长期间充当RNA聚合酶的分子障碍。术语上下文特异性通常被调用来描述具有激活和抑制功能的转录因子。我们定义了ZNF143介导的顺式激活和抑制的背景和分子机制。
    Transcription factors bind to sequence motifs and act as activators or repressors. Transcription factors interface with a constellation of accessory cofactors to regulate distinct mechanistic steps to regulate transcription. We rapidly degraded the essential and ubiquitously expressed transcription factor ZNF143 to determine its function in the transcription cycle. ZNF143 facilitates RNA Polymerase initiation and activates gene expression. ZNF143 binds the promoter of nearly all its activated target genes. ZNF143 also binds near the site of genic transcription initiation to directly repress a subset of genes. Although ZNF143 stimulates initiation at ZNF143-repressed genes (i.e. those that increase expression upon ZNF143 depletion), the molecular context of binding leads to cis repression. ZNF143 competes with other more efficient activators for promoter access, physically occludes transcription initiation sites and promoter-proximal sequence elements, and acts as a molecular roadblock to RNA Polymerases during early elongation. The term context specific is often invoked to describe transcription factors that have both activation and repression functions. We define the context and molecular mechanisms of ZNF143-mediated cis activation and repression.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Journal Article
    选择性催化氧化(SCO)是去除NH3燃料发动机废气中逸出的高浓度氨的有效方法。在此,通过将硫酸化的Ce/ZrO2(Ce/ZrO2-S)与一小部分Pt/Al2O3(Pt0.1wt。%)为NH3的SCO。不出所料,少量Pt/Al2O3的引入显著提高了Ce/ZrO2-S催化剂向低温方向的NH3转化能力。当Pt/Al2O3与Ce/ZrO2-S的质量比为7.5%时(相应的混合催化剂表示为P@CZS-7.5),T90温度为312°C。更重要的是,P@CZS-7.5催化剂在宽温度范围(320〜450°C)内表现出更好的N2选择性(>96%)。H2-TPR结果表明,添加痕量的Pt/Al2O3显著导致还原温度峰向低温方向明显移动,从而大大提高了混合催化剂的低温氧化还原性能。此外,NH3-TPD和BET结果表明,P@CZS-7.5催化剂表现出与Ce/ZrO2-S催化剂相似的NH3吸附能力,而前者比后者具有相对较高的比表面积。它被认为是P@CZS-7.5催化剂在高浓度NH3(5000ppm)去除过程中保持优异的N2选择性的关键因素。原位DRIFTS结果表明,P@CZS-7.5催化剂在NH3-SCO反应中遵循内部选择性催化还原(i-SCR)机理。
    The selective catalytic oxidation (SCO) is an effective method for removing slipped high-concentration ammonia from NH3-fueled engine exhaust gas. Herein a novel bifunctional catalyst was synthesized by mechanically mixing sulfated Ce/ZrO2 (Ce/ZrO2-S) with a small fraction of Pt/Al2O3 (Pt 0.1 wt.%) for SCO of NH3. As expected, the introduction of a small amount of Pt/Al2O3 significantly improved NH3 conversion ability of Ce/ZrO2-S catalysts toward low-temperature direction. When the mass ratio of Pt/Al2O3 to Ce/ZrO2-S was 7.5% (the corresponding mixed catalyst was denoted as P@CZS-7.5), T90 temperature was 312 °C. More importantly, P@CZS-7.5 catalyst exhibited a much better N2 selectivity (> 96%) in a wide temperature range (320 ~ 450 °C). H2-TPR results revealed that the addition of a trace amount of Pt/Al2O3 significantly led to a distinct shift of reduction temperature peak toward low-temperature direction, thereby greatly improved the low-temperature redox performance of mixed catalysts. Furthermore, NH3-TPD and BET results showed that P@CZS-7.5 catalyst exhibited a similar NH3 adsorption capacity to Ce/ZrO2-S catalyst, while the former had a relatively higher specific surface area than the latter. It was considered as a crucial factor for P@CZS-7.5 catalyst maintaining superior N2 selectivity in high-concentration NH3 (5000 ppm) removal processes. In situ DRIFTS results indicated that P@CZS-7.5 catalyst followed the internal selective catalytic reduction (i-SCR) mechanism in NH3-SCO reactions.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    木质纤维素生物质的酶促降解提供了一种生态友好的方法来产生增值的大分子,例如,生物活性多糖。来自天蚕木霉ND-1的新型嗜酸GH5β-1,4-内切葡聚糖酶(称为TaCel5)在波氏杆菌属中有效表达(约1.5倍增加,38.42U/mL)。TaCel5显示了内切葡聚糖酶(486.3U/mg)和藻酸盐裂解酶(359.5U/mg)的酶活性。它具有最佳的pH3.0和强的pH稳定性(在pH范围3.0-5.0内保持超过86%的活性)。在15%乙醇或3.42MNaCl存在下,保留了80%的活性(内切葡聚糖酶和藻酸盐裂解酶)。作用模式分析显示,TaCel5的水解活性需要至少三个葡萄糖(细胞三糖)残基,主要产生纤维二糖。Glu241和Glu352是必需的催化残基,而Asp106、Asp277和Asp317在纤维素降解中起辅助作用。TaCel5对葡聚糖和藻酸盐底物显示出高水解效率。ESI-MS分析表明,藻酸盐的酶解产物主要含有二糖和七糖。这是来自天蚕的双功能GH5内切葡聚糖酶/藻酸盐裂解酶的第一个详细报道。因此,TaCel5在食品和饲料工业中具有强大的潜力,可作为将含有纤维素和藻酸盐的废料生物转化为增值产品寡糖的催化剂,这对经济和环境都有很大的好处。
    Enzymatic degradation of lignocellulosic biomass provides an eco-friendly approach to produce value-added macromolecules, e.g., bioactive polysaccharides. A novel acidophilic GH5 β-1,4-endoglucanase (termed TaCel5) from Trichoderma asperellum ND-1 was efficiently expressed in Komagataella phaffii (∼1.5-fold increase, 38.42 U/mL). TaCel5 displayed both endoglucanase (486.3 U/mg) and alginate lyase (359.5 U/mg) enzyme activities. It had optimal pH 3.0 and strong pH stability (exceed 86 % activity retained over pH range 3.0-5.0). 80 % activity (both endoglucanase and alginate lyase) was retained in the presence of 15 % ethanol or 3.42 M NaCl. Analysis of action mode revealed that hydrolytic activity of TaCel5 required at least three glucose (cellotriose) residues, yielding mainly cellobiose. Glu241 and Glu352 are essential catalytic residues, while Asp106, Asp277 and Asp317 play auxiliary roles in cellulose degradation. TaCel5 displayed high hydrolysis efficiency for glucan and alginate substrates. ESI-MS analysis indicated that the enzymatic hydrolysates of alginate mainly contained disaccharides and heptasaccharides. This is the first detailed report of a bifunctional GH5 endoglucanase/alginate lyase enzyme from T. asperellum. Thus TaCel5 has strong potential in food and feed industries as a catalyst for bioconversion of cellulose- and alginate-containing waste materials into value-added products oligosaccharides, which was of great benefit both for the economy and environment.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    使用配位驱动的自组装设计和合成多面体一直是合成化学家感兴趣的研究领域。金属有机多面体是一类复杂的分子结构,由于其不同的结构和潜在的应用,在文献中引起了极大的关注。特此,我们报道了Cu-MOP,在室温下使用2,6-二甲基吡啶-3,5-二羧酸和乙酸铜构建的双功能金属有机立方体。Lewis碱性吡啶基和Lewis酸性铜位点的存在都为串联的一锅脱缩醛-Knoevenagel/Henry反应赋予了Cu-MOP催化活性。研究了溶剂体系和持续时间对反应收率的影响,结果说明了这些金属有机立方面体的潜力,也称为纳米球在催化中的应用。
    The design and synthesis of polyhedra using coordination-driven self-assembly has been an intriguing research area for synthetic chemists. Metal-organic polyhedra are a class of intricate molecular architectures that have garnered significant attention in the literature due to their diverse structures and potential applications. Hereby, we report Cu-MOP, a bifunctional metal-organic cuboctahedra built using 2,6-dimethylpyridine-3,5-dicarboxylic acid and copper acetate at room temperature. The presence of both Lewis basic pyridine groups and Lewis acidic copper sites imparts catalytic activity to Cu-MOP for the tandem one-pot deacetalization-Knoevenagel/Henry reactions. The effect of solvent system and time duration on the yields of the reactions was studied, and the results illustrate the promising potential of these metal-organic cuboctahedra, also known as nanoballs for applications in catalysis.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    追求有效和耐用的双功能电催化剂在酸性介质中的整体水分解是非常可取的,尽管具有挑战性。SrIrO3基钙钛矿对析氧反应(OER)具有电化学活性,然而,它们对析氢反应(HER)的惰性活性严重限制了整体水分解的实际实施。在这里,Ir@SrIrO3异质结是通过部分溶解方法新开发的,确保OER和她强大的金属支撑相互作用。值得注意的是,Ir@SrIrO3-175电催化剂,通过在175°C的5%H2气氛中退火SrIrO3制备,OER在10mAcm-2时提供229mV的超低过电位,在10mAcm-2时提供28mV的超低过电位,超越了最近报道的双功能电催化剂。此外,使用Ir@SrIrO3-175双功能电催化剂的水电解槽具有高电化学性能和在酸性环境中优异的耐久性,具有潜在的应用前景。理论计算揭示了构建Ir@SrIrO3异质结调节界面电子再分布,最终为OER和她实现低能量障碍。
    The pursuit of efficient and durable bifunctional electrocatalysts for overall water splitting in acidic media is highly desirable, albeit challenging. SrIrO3 based perovskites are electrochemically active for oxygen evolution reaction (OER), however, their inert activities toward hydrogen evolution reaction (HER) severely restrict the practical implementation in overall water splitting. Herein, an Ir@SrIrO3 heterojunction is newly developed by a partial exsolution approach, ensuring strong metal-support interaction for OER and HER. Notably, the Ir@SrIrO3-175 electrocatalyst, prepared by annealing SrIrO3 in 5% H2 atmosphere at 175 °C, delivers ultralow overpotentials of 229 mV at 10 mA cm-2 for OER and 28 mV at 10 mA cm-2 for HER, surpassing most recently reported bifunctional electrocatalysts. Moreover, the water electrolyzer using the Ir@SrIrO3-175 bifunctional electrocatalyst demonstrates the potential application prospect with high electrochemical performance and excellent durability in acidic environment. Theoretical calculations unveil that constructing Ir@SrIrO3 heterojunction regulates interfacial electronic redistribution, ultimately enabling low energy barriers for both OER and HER.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Journal Article
    描述了一种广泛改进的第二代催化两相策略,用于在磷(V)化合物上对映体选择性合成手性。这个协议,由双官能亚氨基膦(BIMP)催化的前手性亲核去对称,稳定的P(V)前体和随后的对映特异性取代允许不同地获得广泛的C-,N-,来自少数对映体富集的前体的含O-和S-取代的P(V)的化合物。与先前建立的方案相比,新的脲肽BIMP催化剂/噻嗪烯酮离去基团组合允许更宽的底物范围,并提高了反应效率和实用性。然后通过置换剩余的离去基团以及允许甚至进一步的下游多样化,可以将所得的富含对映体的中间体转化为甚至更大范围的不同类别的P(V)化合物。进行了密度泛函理论(DFT)计算,以查明BIMP催化的去对称化的对映选择性的起源,为了合理化优越的催化剂/离去基团组合如何导致我们第二代催化系统的通用性增加,以及在使用格氏试剂进行后期对映特异性SN2@P反应时观察到的保留和反转途径。
    A broadly improved second generation catalytic two-phase strategy for the enantioselective synthesis of stereogenic at phosphorus (V) compounds is described. This protocol, consisting of a bifunctional iminophosphorane (BIMP) catalyzed nucleophilic desymmetrization of prochiral, bench stable P(V) precursors and subsequent enantiospecific substitution allows for divergent access to a wide range of C-, N-, O- and S- substituted P(V) containing compounds from a handful of enantioenriched intermediates. A new ureidopeptide BIMP catalyst/thiaziolidinone leaving group combination allowed for a far wider substrate scope and increased reaction efficiency and practicality over previously established protocols. The resulting enantioenriched intermediates could then be transformed into an even greater range of distinct classes of P(V) compounds by displacement of the remaining leaving group as well as allowing for even further diversification downstream. Density functional theory (DFT) calculations were performed to pinpoint the origin of enantioselectivity for the BIMP-catalyzed desymmetrization, to rationalize how a superior catalyst/leaving group combination leads to increased generality in our second-generation catalytic system, as well as shed light onto observed stereochemical retention and inversion pathways when performing late-stage enantiospecific SN2@P reactions with Grignard reagents.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    肿瘤切除后由于肿瘤复发和感染引起的复杂伤口修复提出了重大的临床挑战。在这项研究中,一种双功能纳米复合免疫水凝胶敷料,SerMA-LJC,旨在解决与修复受感染的受损组织和预防肿瘤复发相关的问题。具体来说,免疫敷料由甲基丙烯酸酐修饰的丝胶(SerMA)和含有lonidamine(Lon)的自组装纳米颗粒(LJC)组成,JQ1,和氯e6(Ce6)。体外和体内实验表明,纳米复合水凝胶敷料可以触发免疫原性细胞死亡(ICD)并具有有效的抗肿瘤作用。此外,这种敷料可以缓解肿瘤细胞的酸性微环境,抑制肿瘤细胞表面PD-L1的过表达,从而改变免疫抑制肿瘤微环境并增强抗肿瘤免疫应答。Further,RNA测序分析表明,水凝胶敷料显着影响与免疫应答正调节相关的途径,凋亡过程,和其他相关途径,从而引发有效的抗肿瘤免疫反应。更重要的是,敷料产生大量的活性氧(ROS),能有效杀灭金黄色葡萄球菌,促进感染性伤口愈合。总之,这种双功能纳米复合免疫水凝胶敷料在预防肿瘤复发和促进感染性伤口愈合方面具有前景。
    Complex wound repair due to tumor recurrence and infection following tumor resection presents significant clinical challenges. In this study, a bifunctional nanocomposite immune hydrogel dressing, SerMA-LJC, is developed to address the issues associated with repairing infected damaged tissues and preventing tumor recurrence. Specifically, the immune dressing is composed of methacrylic anhydride-modified sericin (SerMA) and self-assembled nanoparticles (LJC) containing lonidamine (Lon), JQ1, and chlorine e6 (Ce6). In vitro and in vivo experiments demonstrate that the nanocomposite hydrogel dressing can trigger immunogenic cell death (ICD) and has a potent anti-tumor effect. Moreover, this dressing can mitigate the acidic microenvironment of tumor cells and suppress the overexpression of PD-L1 on the tumor cell surface, thereby altering the immunosuppressive tumor microenvironment and augmenting the anti-tumor immune response. Further, the RNA sequencing analysis revealed that the hydrogel dressing significantly impacts pathways associated with positive regulation of immune response, apoptotic process, and other relevant pathways, thus triggering a potent anti-tumor immune response. More importantly, the dressing generates a substantial amount of reactive oxygen species (ROS), which can effectively kill Staphylococcus aureus and promote infectious wound healing. In conclusion, this dual-function nanocomposite immune hydrogel dressing exhibits promise in preventing tumor recurrence and promoting infectious wound healing.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

公众号