Active Center Research Articles

Enhanced Performance for Li & Na Ion Battery Anodes by Charge Modulation of Interface Through SiC4 and SiN1C3 Active Centers on Silicon Nitrogen Co‐Doped Graphene

AbstractHeteroatom doping of graphene is a powerful approach to develop high‐performance Li and Na ion battery anodes. In this study, silicon‐nitrogen co‐doped graphene (Si−N−GN) nanostructures were successfully synthesized via a rational and scalable solvothermal process. The performances of Si−N−GN in Na+ and Li+ half‐cells were investigated in detail by advanced electrochemical techniques and the obtained results were analyzed in terms of Si−N−GN surface properties, reaction kinetics, and electrode/interface interactions. Si−N−GN exhibited a superior capacity of 540 mAh g−1 at a current density of 0.5 A g−1 for Li+ and improved rate capability for both Li+ and Na+ which are linked with the increased interlayer spacing and enlarged graphene sheets upon Si‐doping. Importantly, the capacity increased with the number of cycles owing to surface electron density redistribution and Si−N−GN/SEI interactions, supported by DFT.

Biomimetic Electronic Communication of Iodine Doped Single-Atom Fe Site for Highly Active and Stable Dopamine Oxidation.

Rational design of highly active and stable catalysts for dopamine oxidation is still a great challenge. Herein, inspired by the catalytic pocket of natural enzymes, an iodine (I)-doped single Fe-site catalyst (I/FeSANC) is synthesized to mimic the catalytic center of heme enzymes in both geometrical and electronic structures, aiming to enhance dopamine (DA) oxidation. Experimental studies and theoretical calculations show that electronic communication between I and FeN5 effectively modulates the electronic structure of the active site, greatly optimizing the overlap of Fe 3d and O 2p orbitals, thereby enhancing OH adsorption. In addition, the electronic communication induced by iodine doping attenuates the attack of proton hydrogen on the active center, thereby enhancing the stability of I/FeSANC. This work provides new insights into the design of highly active and stable single-atom catalysts and enhances the understanding of catalytic mechanisms for DA oxidation at the atomic scale.

A Novel Composite Material UiO-66-Br@MBC for Mercury Removal from Flue Gas: Preparation and Mechanism

To reduce the mercury content in flue gas from coal-fired power plants and to obtain high-performance, low-cost mercury adsorbents, a novel composite material was prepared by structural design through the in situ growth method. Functionalization treatments such as the modification of functional groups and multilayer loading of polymetallic were conducted. These materials include the MOF material UiO-66 and modified biochar doped with Fe/Ce polymetallic, both of which contain unsaturated metal centrals and oxygen-containing functional groups. On the basis of obtaining the effects of adsorption temperature and composite ratio on the Hg0 removal characteristics, coupling and synergistic mechanisms between the various types of active centers included were investigated by using a variety of characterization and analysis tools. The active adsorption sites and oxidation sites were identified during this process, and the constitutive relationship between the physicochemical properties and the performance of Hg0 removal was established. The temperature-programmed desorption technique, Grand Canonical Monte Carlo simulation, and adsorption kinetic model were employed to reveal the mechanism of Hg0 removal. The results showed that the UiO-66-Br@MBC composite adsorbent possessed an excellent Hg0 removal performance at adsorption temperatures ranging from 50 to 250 °C, and targeted construction of adsorption and oxidation sites while maintaining thermal stability. The Hg0 removal by the composites is the result of both adsorption and oxidation. The micropores and small pore mesopores in the samples provide physical adsorption sites. The modified biochar acts as a carrier to facilitate the full exposure of the central metal zirconium ions, the formation of more active sites, and the process of electron transfer. The doping modification of the Br element can enhance the overall redox ability of the sample, and the introduced Fe and Ce polymetallic ions can work in concert to promote the oxidation process of Hg0. The excellent regulation of the ratio between adsorption and oxidation sites on the surface of the composite material finally led to a significant boost in the samples’ capacity to remove Hg0.

Atomically Engineered Chlorine Coordination of Iron in Active Centers for Selectively Catalytic H2O2 Decomposition Toward Efficient Antitumor-Specific Therapy.

The intervention of endogenous H2O2 via nanozymes provides a potential antitumor-specific therapy; however, the role of the nanozyme structure in relation to the selective decomposition of H2O2 to hydroxyl radicals (•OH) is yet to be fully understood, which limits the development of this therapeutic approaches. Herein, an iron single-atom nanozyme (Fe─N2Cl2─C SAzyme) is reported, which is prepared through precise Fe─Cl coordination based on the construction of a characteristic Fe-containing molecule. Fe─N2Cl2─C exhibits efficient catalytic H2O2 decomposition (2.19 × 106 mm-1 s-1), which is the highest among reported SAzymes. More importantly, it is found that H2O2 selectively decomposed into •OH on the Fe─N2Cl2─C surface, which is attributable to the d orbitals of the Fe active center matching the O-2p electrons of the adsorbed hydroxide (*OH) intermediate. Fe─N2Cl2─C is strongly cytotoxic toward a variety of cancer-cell lines in vitro but not to normal cells. Furthermore, Fe─N2Cl2─C shows an outstanding specific therapeutic effect in vivo; it efficiently destroys solid malignant tumors without injuring normal tissue. Altogether, these findings highlight the selective catalytic decomposition of H2O2 to •OH, which is achieved by engineering the active center on the atomic level, thereby providing an avenue for the development of specific nanomedicines with efficient antitumor activities.

Role of selenium in the pathophysiology of cardiorenal anaemia syndrome.

Chronic kidney disease (CKD) and cardiovascular disease (CVD) have multiple bidirectional mechanisms, and anaemia is one of the critical factors that are associated with the progression of the two disorders [referred to as cardiorenal anaemia syndrome (CRAS)]. Several lines of evidence indicate that CRAS confers a worse prognosis, suggesting the need to clarify the underlying pathophysiology. Among the micronutrients (trace elements) that are essential to humans, inadequate iron status has previously been implicated in the pathogenesis of CRAS; however, the roles of other trace elements remain unclear. Selenium critically regulates the function of selenoproteins, in which selenocysteine is present at the active centres. The human genome encodes 25 selenoproteins, and accumulating data indicate that they regulate diverse physiological processes, including cellular redox homeostasis, calcium flux, thyroid hormone activity and haematopoiesis, all of which directly or indirectly influence cardiac function. The essential role of selenium in human health is underscored by the fact that its deficiency results in multiple disorders, among which are cardiomyopathy and abnormal erythrocyte morphology. Studies have shown that selenium deficiency is not uncommon in CKD patients with poor nutritional status, suggesting that it may be an under-recognized cause of anaemia and cardiovascular disorders in these patients. In this review, we discuss the role of selenium in the pathophysiology of CKD, particularly in the context of the interconnection among CKD, cardiac dysfunction and anaemia. Given that selenium deficiency is associated with treatment-resistant anaemia and an increased risk of CVD, its role as a key modulator of CRAS merits future investigation.

Synergistic Coordination in Cu Single-Atom Catalysts Enhances High-Valent Copper-Oxo Species for Efficient PMS Activation.

In the domain of heterogeneous catalytic activation of peroxymonosulfate (PMS), high-valent metal-oxo (HVMO) species are widely recognized as potent oxidants for the abatement of organic pollutants. However, the generation selectivity and efficiency of HVMO are often constrained by stringent requirements for catalyst adsorption sites and electron transfer efficiency. In this study, a single-atom catalyst, CuSA/CNP&S, is synthesized featuring multiple types (planar/axial) of heteroatom coordination via an H-bond-assisted self-assembly strategy. It isconfirmed that CuN3 active centers with axial S coordination are uniformly distributed in a carbon matrix modified by planar P atoms. CuSA/CNP&S activated PMS to selectively generate Cu(III)═OH species as the primary reactive oxygen species (ROS). The pseudo-first-order kinetic rate for bisphenol A degradation reached 1.51min-1, a 17.57-fold increase compared to the unmodified CuSA/CN catalyst. Additionally, the CuSA/CNP&S catalyst demonstrates high efficiency and durability in removing contaminants from various aqueous matrices. Theoretical calculations and experimental results indicate that the intrinsic electric field generated by distal planar P atoms enhances electron transfer efficiency within the carbon matrix. Meanwhile, axial S coordination elevates the d-band center and tunes the eg * band broadening of Cu, thereby enhancing the adsorption selectivity for the terminal oxygen of PMS. This multitype coordination synergistically mitigates the issues of low selectivity and yield of HVMO species.

Developments of Pyrrolo[2,3-d]pyrimidines with Pharmaceutical Potential

Abstract:: In terms of fused heterocyclic compounds, pyrrolopyrimidines, and their substituted analogs are among the most extensively explored scaffolds. Based on the location of the nitrogen atom in the pyrrole ring, pyrrolopyrimidines have different isomers. This study deals only with the pyrrolo[2,3-d]pyrimidine isomer. Several techniques are represented and discussed in this review for producing pyrrolo[2,3-d]pyrimidine derivatives. The first one is the cyclization of the pyrimidine ring on the pyrrole ring through the reaction of β-enaminonitrile, β-enaminoester or β-enaminoamide of the pyrrole ring with different bifunctional reagents such as formic acid, acetic acid, acetic anhydride, formamide, isothiocyanate, urea, thiourea, and carbon disulfide. The second technique includes cyclization of the pyrrole ring on the pyrimidine ring via the treatment of pyrimidine, aminopyrimidine, diamino-pyrimidine, or triamino-pyrimidine with different reagents such as nitroalkenes, alkynes, aldehydes, and acid chlorides. In addition, different reaction methodologies like one pot, two-step, and threestep synthetic methodologies were reported. The last technique for producing pyrrolo[2,3-d]pyrimidine derivatives is through miscellaneous reactions. This review also includes the interactions of pyrrolo[2,3- d]pyrimidines at different active centers of the pyrrole ring with different reagents to form N-alkylated, Nglycosylated, C-5, and C-6 adducts. Besides, the interactions on the pyrimidine ring to form chloro, hydrazino, and amino-imino derivatives were also discussed. The amino-imino derivatives are key intermediates for the preparation of tricyclic pyrrolotriazolopyrimidines. Finally, the pharmaceutical and biological properties of some pyrrolo[2,3-d]pyrimidine derivatives have also been mentioned. This information can be utilized to design novel diverse pyrrolopyrimidine derivatives for recent challenges in pharmaceutical and medical studies to develop the already existing drugs or discover new ones.

Molten salt method for preparing Mn0.3Ru0.7O2 nanosheets as a superior bifunctional catalyst for rechargeable zinc-air batteries

Integrating components for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) while optimizing their electronic structure is an effective strategy for developing excellent bifunctional catalysts for rechargeable zinc-air batteries (ZABs). In this study, we successfully fabricated Mn0.3Ru0.7O2 nanosheets based on a solid solution oxide using a simple molten salt method. The Mn0.3Ru0.7O2 nanosheets exhibits abundant Ru and Mn sites through the Ru-O-Mn structure, which serve as excellent OER and ORR active centers. Experimental and theoretical studies validate the coccurrence of charge transefer between the Ru-O-Mn bond, modulating the valence state and d-band center of the Mn and Ru, thereby subsequently improving their ORR/OER intrinsic activity. Remarkably, the Mn0.3Ru0.7O2 nanosheets displays superior electropcatalytic performance with a charge/discharge voltage gap (ΔE) of only 0.59 V, which is the best among all reported counterpart catalysts. A rechargeable ZAB utilizing Mn0.3Ru0.7O2 nanosheets achieved a power density of 154 mW cm−2 and a specific capacity of 821 mA h g−1, surpassing that of the commercial Pt/C + RuO2 mixing catalyst. This study offers a new strategy for preparing highly active and durable bifunctional catalysts for rechargeable ZABs.

Selective oxidation of methane to formaldehyde and carbon monoxide over V/MSN catalysts with isolated VO4 sites

The selective oxidation of methane to value-added C1 chemicals (e.g., HCHO and CO) is a crucial process in the chemical industry. Recent studies indicate that the generation of highly dispersed isolated active sites is crucial for improving the performance in the selective oxidation of methane and studying the corresponding structure–activity relationship. Therefore, we used mesoporous silica nanoparticles (MSN) as supports and utilized grafting method to prepare catalysts with more selective oxidation active centers (isolated VO4). The study found that isolated VO4 centers are the active sites for the selective oxidation of methane to formaldehyde, and CO is the product of further oxidation of formaldehyde. The total selectivity of formaldehyde and CO on all catalysts is higher than 83.6 %. Among them, the highly dispersed and isolated VO4 tetrahedral active centers on the 2 V/MSN catalyst could stably convert methane to formaldehyde, achieving the highest formaldehyde yield of 3.7 % at 670 °C.

Nitrite reductase-mimicking catalysis temporally regulating nitric oxide concentration gradient adaptive for antibacterial therapy.

The unique bacterial infection microenvironment (IME) usually requires complicated design of nanomaterials to adapt to IME for enhancing antibacterial therapy. Here, an alternative IME adaptative nitrite reductase-mimicking nanozyme is constructed by in situ growth of ultrasmall copper sulfide clusters on the surface of a nanofibrillar lysozyme assembly (NFLA/CuS NHs), which can temporally regulate nitric oxide (NO) gradient concentration to kill bacteria initially and promote tissue regeneration subsequently. Benefiting from a copper nitrite reductase (CuNIR)-inspired structure with CuS cluster as active center and NFLA as skeleton, NFLA/CuS NHs efficiently boost the catalytic reduction of nitrite to NO. The inherent supramolecular fibrillar networks displays excellent bacterial capture capability, facilitating initial high-concentration NO attacks on the bacteria. The subsequent catalytic release of low-concentration NO by NFLA/CuS NHs-mediated nitrite reduction remarkably promotes cell migration and angiogenesis. This work paves the way for dynamically eliminating MDR bacterial infection and promoting tissue regeneration in a simple and smart way through CuNIR-mimicking catalysis.

Synthesis and nootropic activity prediction of some 4-(aminomethyl)-1-benzylpyrrolidin-2-one derivatives structurally related with nebracetam

The aim. Search for new biologically active substances with improved nootropic parameters among analogues of 4-(aminomethyl)-1-benzylpyrrolidine-2-one (Nebracetam). Materials and methods. The required reagents were purified using standard techniques. The elemental analysis was performed on a "Hewlett Packard" automatic analyzer M-180 company. 1H NMR spectra were recorded on Varian Gemini 400 MHz spectrometer in DMSO-d6 as a solvent. LC/MS spectra were recorded with a PE SCIEX API 150EX liquid chromatograph equipped. The Autodock 4.2 software package was used for molecular docking. The active centers of the peptides (PDB ID: 5CXV, 6PV7) was used as the biologycal targets. Results and discussion. Basic and alternative methods (1 and 2) of obtaining were used to synthesise target analogues of 4-(aminomethyl)-1-R-benzylpyrrolidine-2-one. As a result of synthetic studies, an optimized method with an alternative method has been proposed. The advantages include reducing the duration and number of synthesis stages and avoiding the use of sodium azide, a highly toxic and hazardous substance. Molecular docking of the synthesized compounds at well-documented acetylcholine receptor sites indicates that all tested molecules will contribute to the manifestation of nootropic activity to varying degrees through cholinergic neurotransmission mechanisms. This is evidenced by the calculated docking values in relation to the muscarinic target. According to the docking results, it was found that depending on the enantiomeric configuration, the molecules formed stable complexes with the target and had characteristic binding modes both in the orthosteric site and in the extracellular vestibule (site of positive allosteric modulation of mAChR). It indicates the prospects of modifying the "nebracetam scaffold" at the phenyl fragment with halogen substituents. Conclusions. An effective method for synthesising analogues of 4-(aminomethyl)-1-R-benzylpyrrolidin-2-ones has been developed. The molecular docking revealed potential mechanisms of nootropic action of the synthesized derivatives as potential agonists and positive allosteric modulators of the muscarinic receptor

Application of fluorescent probe for labile heme quantification in physiological dynamics

Heme is an essential prosthetic molecule for life activities and is well known to act as the active center of many proteins, however, labile heme (LH) released from proteins is a harmful molecule that produces reactive oxygen species and must be strictly controlled. Recently, LH has been suggested to function as an important molecule for diverse physiological responses. Quantitative analysis of the intracellular dynamics of LH is essential for understanding its physiological functions, a substantially practical method has not been established. Here, we successfully developed an alternative method that can be used to complement quantification of the dynamics of intracellular LH using H-FluNox, an activity-based specific fluorescent probe recently constructed. Our newly established method should be effective in elucidating the physiological functions of LH.

A long-cycle-life reversible Li-CO2 battery enabled by engineering the active sites of graphene with Pd nanoparticles.

Li-CO2 batteries have been recognized as an emerging technology for energy storage systems owing to their high theoretical specific energy and environmentally friendly CO2 fixation ability. However, their development for applications requires a high energy efficiency and long cycle-life, this is currently limited to the formation of wide-bandgap insulator Li2CO3 during discharge. Here, nanoparticle Pd supported on reduced graphene oxide (rGO) is utilized as cathodes for Li-CO2 batteries, Pd nanoparticles as active centers significantly enhance CO2RR/CO2ER reaction activity, which can support the fast formation and decomposition of Li2CO3 in organic electrolytes and achieve a high discharge capacity of 7500 mAh g-1. It also performs remarkably high cycling stability of over 500 cycles with a long cycle-life of 5000 hours. The observed super electrochemical performance is attributable to the thick electrode design and uniform distribution of ultrafine catalyst nanoparticle Pd. When Li2CO3 is adsorbed on Pd particle, the Li-O bond in Li2CO3 will be elongated due to the interactions of two nucleophilic O atoms with Pd, resulting in a weakening of the Li-O bond and activation of Li2CO3. Our work suggests a way to design catalysts with high activity that can be used to activate the performance of Li-CO2 batteries.

MnS doping regulating Co active sites on fibrous cobalt nitride as bifunctional oxygen electrocatalyst for high-performance Zn-air battery

Aiming to achieve high-efficiency bifunctional catalysts, doping engineering is applied to construct bifunctional catalysts for oxygen electrodes in Zn-air batteries to strengthen the catalytic kinetics of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Herein, MnS doped cobalt nitride catalyst (MnS/CoNx) with divergent fiber morphology is prepared by low temperature nitriding for the self-assembling layered double hydroxides (LDH). The MnS/CoNx shows excellent electrical conductivity and improved catalytic activity on ORR and OER with low overpotential of 290 mV at 10 mA cm−2 and a good half-wave potential of 0.80 V in ORR compared with CoNx and MnO/CoNx. The contribution of the increased bifunctional catalytic performance is possible from the more active center Co3+ and Mn4+, and the elevated electron transport resulted from the opportune high conductive MnS doping. The MnS/CoNx catalyst-driven Zn-air battery achieves a higher power density of 228 mW cm−2 and the excellent long-term stability of 500 h at 20 mA cm−2 far surpassing the commercial Pt/C+RuO2 catalyst.

Effect of Ionizing Radiation on the Activity of the Enzyme Invertase Studied by Polarimetry

The effect of ionizing radiation on biological systems, and particularly the enzymes which are responsible for most cellular functions, leads to chemical alterations in their molecular structure, and as a subsequent result often causes inhibition of their activities. Of particular importance for understanding the molecular and kinetic mechanisms of action of ionizing radiation on these systems is to find suitable experimental protocols and kinetic models applicable to specific enzymes and their substrates. In the present study we offer a convenient experimental approach by applying polarimetric measurements to study the influence of ionizing radiation on the catalytic action of the enzyme invertase. Following the Michaelis- Menten kinetic model we determined the values of the kinetic constants Km и Vmax for the reactions catalyzed either by the native or irradiated invertase and made some conclusions about possible changes either in the active centre or in the molecular structure of the enzyme under the action of ionizing radiation.

Origin of Efficient and Tunable Dual‐Band Emission From Zinc Chalcogenide Quantum Dots for Sustainable Photonics

AbstractImpurity‐induced optical modulation in quantum‐confined colloidal nanocrystals has attracted intense interest thanks to the unique fundamental photo‐physics and application prospects. However, the present doping strategy is still facing limitations including spectral tunability and impurity controllability. Herein, a new route toward the tunable and efficient dual‐band emission in chlorine‐doped ZnSe (ZnSe:Cl) eco‐friendly quantum dots (QDs) is provided. Corroborated by the comprehensive spectroscopic characterization and first‐principles calculations, the emerging broadband sub‐gap emission is disclosed to originate from the self‐activating center constituted by a fusion of a Cl‐substituted Se point defect and a nearby Zn vacancy (ClSe‐VZn pair). First‐principles calculations confirm that the optically active center state stems from the distorted electron states of Se atoms surrounding the impurity rather than the Cl electron orbitals, which results in robust sub‐gap emission at ambient conditions. A dynamic model involving the transition between the charge and neutral states of the self‐activated center is established. By virtue of the controllable dual‐emission states, the transparent information encryption and the single‐component white light‐emitting diodes are realized, demonstrating the promising potential in sustainable photonic applications.

Enhancement of hydrogen-rich gas production by acetic acid steam reforming: characterization of Ni–Co modified biochar-based catalysts

Abstract The development of cost-effective and highly efficient biochar-based catalysts is essential for the catalytic steam reforming process of bio-oil. In this study, pickling peanut shell biochar was used to prepare biochar-supported Ni/Co monometallic catalyst and biochar-supported nickel-Co bimetallic catalyst through the impregnation method. The catalytic effect of these catalysts on acetic acid (a bio-oil model compound) steam reforming was investigated. It was found that Co could enhance the dispersion of metal particles. The catalyst exhibited the best catalytic effect and significantly improved resistance to carbon deposition with a loading of 8 wt% and a Ni-to-Co ratio of 6:2. At the temperature of 600 °C and the S/C ratio of 3, the selectivity of H2 reached 84.48 %, and the conversion of acetic acid reached 95.49 %. A synergistic effect was observed between Ni and Co, leading to increased metal dispersion, enhanced reducibility, and a higher number of active centers. Co facilitates water dissociation and promotes the oxidation of C–H and mobile O, resulting in a faster decarbonization rate. The effective utilization of biochar-based catalysts and the rational utilization of bio-oil contribute to the timely achievement of carbon emission reduction targets.

Catalytic property and synergistic effect of the multi-active sites Pd/PdO/Er2O3/Cu2O/PdCu3 formed in situ on the surface of the tri-organometallic Pd(II)/Er(III)/Cu(II) film

Explaining the formation and synergistic effect in multi-active sites is a vital factor in designing a highly efficient catalyst. In this study, a series of new graphene oxide(GO) supported arylimine Pd(II), Pd(II)/Er(III), and Pd(II)/Cu(II), Pd(II)/Er(III)/Cu(II) (GO@A-Pchmba-Pd, GO@A-Pchmba-Pd0.1Er0.9, GO@A-Pchmba-Pd0.1Cu0.9, GO@A-Pchmba-Pd0.1Er0.4Cu0.5) catalytic films were fabricated using self-assembly. Among these catalysts, GO@A-Pchmba-Pd0.1Er0.4Cu0.5 exhibited the highest activity (TOF = 145,506 h−1) in Suzuki cross-coupling reaction with a good compatibility, but poor recycling stability. The catalytic film acted not only as a "reservoir" to supply the active sites, but "stabilizer" to stabilize the active species, which provided a research platform to gain deep insight into the truly active center. The synergistic effect in the truly active center containing Pd/PdO/Cu2O/Er2O3/PdCu3 was described as that: the electron transferred from GO to Pd/Er/Cu via ligand, and then the electron transferred from erbium to palladium or its oxide, or from erbium to copper or cuprous oxide and then to palladium, resulting in enhancing the more electronegative Pd and further promoting the activity. The aggregation of the active metals, the loss of the active metals, residues absorbed on the surface, some destroyed organometallic in film, and the reduced average pore size were the crucial reasons for the deactivation and instability.

Engineering a Ce Promoter into a Three-Dimensional Porous Mo2C@NC Heterostructure for Hydrogen Evolution Electrocatalysis via Weakening the Mo-H Bond Strength.

The pursuit of highly efficient electrocatalysts for the alkaline hydrogen evolution reaction (HER) is of paramount importance for water splitting. However, it is still a formidable task in Mo2C-based materials because of the agglomeration and strong Mo-H binding of Mo2C units. Herein, a novel CeOCl-CeO2/Mo2C heterostructure nesting within a three-dimensional porous nitrogen-doped carbon matrix has been designed and used for catalyzing HER via simultaneous morphology and heterointerface engineering. As expected, the optimal CeOCl-CeO2(0.2)/Mo2C@3DNC exhibits impressive HER activity, with a low overpotential of 156 mV at a current density of 10 mA cm-2 coupled with a slight Tafel slope of 62.20 mV dec-1. Introducing a Ce promoter, that is CeOCl and CeO2, would endow the interface with an internal electric field and electron redistribution between CeOCl-CeO2 and Mo2C induced by the heterogeneous work function difference. Moreover, experimental investigation and density functional calculations confirm that the CeOCl-CeO2/Mo2C heterointerface can downshift the d-band center of the active Mo center, weakening the strength of the Mo-H coupling. This proposed concept, engineering Ce-based promoters into active entities involved in the heterostructure to modulate intermediate adsorption, offers a great opportunity for the design of superior electrocatalysts for energy conversion.

PTCOG international survey of practice patterns and trends in utilization of proton therapy for breast cancer

Purpose/objectivesThe indications, techniques, and extent to which proton beam therapy (PBT) is employed for breast cancer are unknown. We seek to determine PBT utilization for breast cancer. Materials/methodsThe Particle Therapy Co-Operative Group (PTCOG) Breast Subcommittee developed an IRB-approved 29-question survey and sent it to breast cancer radiation oncologists at all active PBT centers worldwide in June 2023. Descriptive statistics were used to summarize responses, and comparisons by continent were performed using Fisher’s exact tests. ResultsOf 79 surveys distributed, 28 recipients submitted responses (35 % response rate) representing fifteen U.S., 8 European, and 5 Asian centers (continent response rate 50 %, 38 %, and 18 %, respectively). Overall, 93 % reported treating breast cancer patients with PBT; 13 (50 %) have treated ≥100 breast cancer patients at their center since opening. Most (89 %) have pencil beam scanning technology. Nearly half (46 %) use moderate hypofractionation (15–20 fractions) for regional nodal irradiation and 42 % conventional fractionation (25–30 fractions). More European centers prefer hypofractionation (88 %) vs. Asian (50 %) and U.S. (21 %) centers (p = 0.003). Common patient selection methods were practitioner determination/patient preference (n = 16) and comparative plan evaluation (n = 15). U.S. centers reported the most experience with breast PBT, with 71 % having treated ≥100 breast cancer patients vs. 38 % in Europe and none in Asia (p = 0.001). Of respondent centers, 39 % enrolled ≥75 % of breast PBT patients on a research study. ConclusionUtilization, patient selection methods, and dose-fractionation approaches for breast cancer PBT vary worldwide. These survey data serve as a benchmark from which successor surveys can provide insight on practice pattern evolution.