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Spinel-type catalysts are promising anode materials for the alkaline oxygen evolution reaction (OER), exhibiting low overpotentials and providing long-term stability. In this study, we compared two structurally equal Co2FeO4 spinels with nominally identical stoichiometry and substantially different OER activities. In particular, one of the samples, characterized by a metastable precatalyst state, was found to quickly achieve its steady-state optimum operation, while the other, which was initially closer to the ideal crystallographic spinel structure, never reached such a state and required 168 mV higher potential to achieve 1 mA/cm2. In addition, the enhanced OER activity was accompanied by a larger resistance to corrosion. More specifically, using various ex situ, quasi in situ, and operando methods, we could identify a correlation between the catalytic activity and compositional inhomogeneities resulting in an X-ray amorphous Co2+-rich minority phase linking the crystalline spinel domains in the as-prepared state. Operando X-ray absorption spectroscopy revealed that these Co-rich domains transform during OER to structurally different Co3+-rich domains. These domains appear to be crucial for enhancing OER kinetics while exhibiting distinctly different redox properties. Our work emphasizes the necessity of the operando methodology to gain fundamental insight into the activity-determining properties of OER catalysts and presents a promising catalyst concept in which a stable, crystalline structure hosts the disordered and active catalyst phase.

Nanoscale ruthenium (Ru)-based materials are promising replacements for existing multilayered Cu interconnects in integrated circuits. However, it is not easy to apply the results of previously reported studies directly to the electrochemical damascene process because the previous studies have mainly focused on thin films by dry deposition. Here, we report the electrical resistivity and microstructure of electrodeposited Ru nanowires. We estimate that the resistivity value of a 10 nm diameter Ru nanowire to be 71.6 μΩ cm after analyzing the resistivity values of individual nanowires with various diameters. Furthermore, we investigate the electrical properties of RuxCo1-x nanowires where x is 0.04–0.99 at.% as possible replacements of the current TaN barrier structures. Over the entire composition range, the resistivity values of alloys are much lower than that of the conventional TaN. Additionally, Ru and Ru-alloy nanowires surrounded by dielectric silica are thermally stable after 450 °C heat treatment. Therefore, the nanoscale Ru and Ru-Co alloys possessing low resistivity values can be candidates for the interconnect and barrier materials, respectively.

Copper-based catalysts are established catalytic systems for the electrocatalytic CO2 reduction reaction (CO2RR), where wasteful CO2 is converted into valuable industrial resources, such as energy-dense C2+ products, using energy from renewable sources. However, better control over the catalyst selectivity, especially at industrially relevant high current density conditions is needed to expedite the economically viability of the CO2RR. For this purpose, bimetallic materials, where copper is combined with a secondary metal, comprise a promising and a highly tunable catalyst for CO2RR. However, the synergy between copper and the selected secondary metal species, the evolution of the bimetallic structural motifs under working conditions and the effect of the secondary metal on the kinetics of the Cu redox behavior require careful investigation. Here, we employ operando quick X-ray absorption spectroscopy (QXAFS), coupled with machine-learning based data analsysis and surface-enhanced Raman spectroscopy (SERS) to investigate the time-dependent chemical and structural changes in catalysts derived from shape-selected Zn/Cu2O nanocubes under CO2RR conditions at current densities up to -500 mA/cm2. We furthermore relate the transformation observed under working conditions to the catalytic activity and selectivity and correlate potential-dependent surface and subsurface processes. We report that the addition of Zn to a Cu-based catalyst has crucial impact on the kinetics of subsurface processes, while redox processes of the Cu surface layer remain largely unaffected. Interestingly, the presence of Zn was found to contribute to the stabilization of cationic Cu(I) species, which is of catalytic relevance since Cu(0)/Cu(I) interfaces have been reported beneficial for the efficient CO2 conversion to complex multicarbon products. At the same time, we attribute the increase of the C2+ product selectivity to the formation of Cu-rich CuZn alloys in samples with low Zn content, while Zn-rich alloy phases result in an increased formation of CO paralleled by an increase of the parasitic hydrogen evolution reaction.

Journal of the American Chemical Society 145(7), 4065 – 4080 (2023). doi:10.1021/jacs.2c11824, Bimetallic transition-metal oxides, such as spinel-like Co$_x$Fe$_{3–x}$O$_4$ materials, are known as attractive catalysts for the oxygen evolution reaction (OER) in alkaline electrolytes. Nonetheless, unveiling the real active species and active states in these catalysts remains a challenge. The coexistence of metal ions in different chemical states and in different chemical environments, including disordered X-ray amorphous phases that all evolve under reaction conditions, hinders the application of common operando techniques. Here, we address this issue by relying on operando quick X-ray absorption fine structure spectroscopy, coupled with unsupervised and supervised machine learning methods. We use principal component analysis to understand the subtle changes in the X-ray absorption near-edge structure spectra and develop an artificial neural network to decipher the extended X-ray absorption fine structure spectra. This allows us to separately track the evolution of tetrahedrally and octahedrally coordinated species and to disentangle the chemical changes and several phase transitions taking place in Co$_x$Fe$_{3–x}$O$_4$ catalysts and on their active surface, related to the conversion of disordered oxides into spinel-like structures, transformation of spinels into active oxyhydroxides, and changes in the degree of spinel inversion in the course of the activation treatment and under OER conditions. By correlating the revealed structural changes with the distinct catalytic activity for a series of Co$_x$Fe$_{3–x}$O$_4$ samples, we elucidate the active species and OER mechanism., Published by ACS Publications, Washington, DC

Purpose Effectiveness and safety of clofarabine (one of the treatment mainstays in pediatric patients with relapsed/refractory acute lymphoblastic leukemia [ALL]) was assessed in Korean pediatric patients with ALL to facilitate conditional coverage with evidence development.Materials and Methods In this multicenter, prospective, observational study, patients receiving clofarabine as mono/combination therapy were followed up every 4-6 weeks for 6 months or until hematopoietic stem cell transplantation (HSCT). Response rates, survival outcomes, and adverse events were assessed.Results Sixty patients (2-26 years old; 65% B-cell ALL, received prior ≥ 2 regimen, 68.3% refractory to previous regimen) were enrolled and treated with at least one dose of clofarabine; of whom 26 (43.3%) completed 6 months of follow-up after the last dose of clofarabine. Fifty-eight patients (96.7%) received clofarabine combination therapy. Overall remission rate (complete remission [CR] or CR without platelet recovery [CRp]) was 45.0% (27/60; 95% confidence interval [CI], 32.4 to 57.6) and the overall response rate (CR, CRp, or partial remission [PR]) was 46.7% (28/60; 95% CI, 34.0 to 59.3), with 11 (18.3%), 16 (26.7%), and one (1.7%) patients achieving CR, CRp, and PR, respectively. The median time to remission was 5.1 weeks (95% CI, 4.7 to 6.1). Median duration of remission was 16.6 weeks (range, 2.0 to 167.6 weeks). Sixteen patients (26.7%) proceeded to HSCT. There were 24 deaths; 14 due to treatment-emergent adverse events.Conclusion Remission with clofarabine was observed in approximately half of the study patients who had overall expected safety profile; however, there was no favorable long-term survival outcome in this study.

This study aimed to evaluate the infection control rate of palliative arthroscopic debridement, antibiotics, and implant retention (DAIR) for the high mortality risk or terminal cancer stage patients.From March 2018 to August 2021, 21 patients met the following inclusion criteria: old age of more than 80, diagnosed as a terminal stage of cancer, high risk of mortality and morbidity representing as Charlson comorbidity index (CCI) ≥ 5, low daily activity with disabled extremity, and re-infection after two-stage revision. Each patient underwent arthroscopic DAIR and additional continuous irrigation for 48 hours. The need for subsequent re-arthroscopic DAIR or two-stage revision was determined by the post-operative trends of C-reactive protein (CRP) levels. Infection control was defined as continuing controlled status of infection based on clinical and laboratory results by one or two times of arthroscopic DAIR within initial two months. Treatment failure was defined as more than three times arthroscopic debridement, two-stage revision surgery, or expired due to uncontrolled infection.Arthroscopic DAIR controlled the infection in 19 (90.5%) of the 21 cases. The other knee underwent a total of three times of re-arthroscopic DAIR and the other one underwent two-stage revision. Although five patients expired during the follow-up period due to worsening medical problems or terminal cancer, there were no deaths from uncontrolled infection, sepsis, or surgery-related complications.Arthroscopic debridement with continuous irrigation for the infection TKA with high mortality risk or terminal cancer patients showed a 90.5% infection control rate. For high-risk patients, arthroscopic debridement with continuous irrigation can be an alternative treatment to improve the quality of life during survival.

BACKGROUND Relative to interscalene block, superior trunk block (STB) provides comparable analgesia and a reduced risk of hemidiaphragmatic paralysis. However, the incidence of hemidiaphragmatic paralysis remains high when a standard volume (15 mL) of local anesthetic is used. This study aimed to evaluate the effects of local anesthetic volume of STB on the incidence of phrenic nerve palsy, as well as its analgesic efficacy following arthroscopic shoulder surgery. METHODS Patients scheduled for elective arthroscopic shoulder surgery were randomized to receive ultrasound-guided STB using either 5- or 15-mL 0.5% ropivacaine before general anesthesia. The primary outcome was the incidence of hemidiaphragmatic paralysis at 30 minutes after block. The secondary outcomes were pulmonary function, grade of sensory and motor blockade, pain score, opioid consumption, adverse effects, and satisfaction. RESULTS Relative to standard-volume STB, low-volume STB was associated with a lower incidence of hemidiaphragmatic paralysis after block (14.3 [4.8%-30.3%] vs 65.7 [46.8%-80.9%]; difference 51.4% [95% confidence intervals {CIs}, 29.0%-67.1%]; P < .0001) and at the postanesthesia care unit (9.4% vs 50.0%; difference 40.6 [95% CI, 18.9%-57.7%]; P = .0004). Pulmonary function was also better preserved in the low-volume group than in the standard-volume group. The extent of the sensory and motor blocks was significantly different between the groups. Pain-related outcomes, satisfaction, and any adverse events were not significantly different between the groups. CONCLUSIONS Low-volume STB provided a lower incidence of hemidiaphragmatic paralysis with no significant difference in analgesic efficacy relative to standard-volume STB for arthroscopic shoulder surgery.

In this study, we have taken advantage of a pulsed CO$_2$ electroreduction reaction (CO$_2$RR) approach to tune the product distribution at industrially relevant current densities in a gas-fed flow cell. We compared the CO$_2$RR selectivity of Cu catalysts subjected to either potentiostatic conditions (fixed applied potential of −0.7 V$_{RHE}$) or pulsed electrolysis conditions (1 s pulses at oxidative potentials ranging from $E_{an}$ = 0.6 to 1.5 V$_{RHE}$, followed by 1 s pulses at −0.7 VRHE) and identified the main parameters responsible for the enhanced product selectivity observed in the latter case. Herein, two distinct regimes were observed: (i) for $E_{an}$ = 0.9 V$_{RHE}$ we obtained 10% enhanced C$_2$ product selectivity (FE$_{C_2H_4}$ = 43.6% and FE$_{C_2H_5OH}$ = 19.8%) in comparison to the potentiostatic CO$_2$RR at −0.7 V$_{RHE}$ (FE$_{C_2H_4}$ = 40.9% and FE$_{C_2H_5OH}$ = 11%), (ii) while for $E_{an}$ = 1.2 V$_{RHE}$, high CH$_4$ selectivity (FE$_{CH_4}$ = 48.3% vs 0.1% at constant −0.7 V$_{RHE}$) was observed. Operando spectroscopy (XAS, SERS) and ex situ microscopy (SEM and TEM) measurements revealed that these differences in catalyst selectivity can be ascribed to structural modifications and local pH effects. The morphological reconstruction of the catalyst observed after pulsed electrolysis with $E_{an}$ = 0.9 V$_{RHE}$, including the presence of highly defective interfaces and grain boundaries, was found to play a key role in the enhancement of the C$_2$ product formation. In turn, pulsed electrolysis with $E_{an}$ = 1.2 V$_{RHE}$ caused the consumption of OH$^–$ species near the catalyst surface, leading to an OH-poor environment favorable for CH$_4$ production.

Direct conversion of carbon dioxide into multicarbon liquid fuels by the CO2 electrochemical reduction reaction (CO2RR) can contribute to the decarbonization of the global economy. Here, well‐defined Cu2O nanocubes (NCs, 35 nm) uniformly covered with Ag nanoparticles (5 nm) were synthesized. When compared to bare Cu2O NCs, the catalyst with 5 at% Ag on Cu2O NCs displayed a two‐fold increase in the Faradaic efficiency for C2+ liquid products (30% at ‐1.0 VRHE), including ethanol, 1‐propanol, and acetaldehyde, while formate and hydrogen were suppressed. Operando X‐ray absorption spectroscopy revealed the partial reduction of Cu2O during CO2RR, accompanied by a reaction‐driven redispersion of Ag on the CuOx NCs. Operando surface‐enhanced Raman spectroscopy data further uncovered significant variations in the CO binding to Cu, which were assigned to Ag‐Cu sites formed during CO2RR that appear crucial for the C‐C coupling and the enhanced yield of liquid products.

BACKGROUND Anastomotic stenosis (AS) after colorectal surgery was treated with balloon dilation, endoscopic procedure or surgery. The endoscopic procedures including dilation, electrocautery incision, or radial incision and cutting (RIC) were preferred because of lower complication rates than surgery and are less invasive. Endoscopic RIC has a greater success rate than dilation methods. Most reports showed that repeated RICs were needed to maintain patency of the anastomosis. We report that single session RIC was applied only to treatment-naive patients with AS. CASE SUMMARY Two female patients presented with AS. One patient had advanced rectal cancer and the other had a refractory stenosis following surgery for endometriosis at sigmoid colon. The endoscopic RIC procedure was performed as follows. A single small incision was carefully made to increase the view of the proximal colon and the incision was expanded until the surgical stapling line. Finally, we made a further circumferential excision with endoscopic knife along the inner border of the surgical staple line. At the end of the procedure, the standard colonoscope was able to pass freely through the widened opening. All patients showed improved AS after a single session of RIC without immediate or delayed procedure-related complications. Follow-up colonoscopy at 7 and 8 mo after endoscopic RIC revealed intact anastomotic sites in both patients. No treatment-related adverse events or recurrence of the stenosis was demonstrated during follow-up periods of 20 and 23 mo. CONCLUSION The endoscopic RIC may play a role as one of treatment options for treatment-naive AS with short stenotic lengths.

Macrophages can associate with extracellular matrix (ECM) demonstrating nanosequenced cell-adhesive RGD ligand. In this study, we devised barcoded materials composed of RGD-coated gold and RGD-absent iron nanopatches to show various frequencies and position of RGD-coated nanopatches with similar areas of iron and RGD-gold nanopatches that maintain macroscale and nanoscale RGD density invariant. Iron patches were used for substrate coupling. Both large (low frequency) and externally positioned RGD-coated nanopatches stimulated robust attachment in macrophages, compared with small (high frequency) and internally positioned RGD-coated nanopatches, respectively, which mediate their regenerative/anti-inflammatory M2 polarization. The nanobarcodes exhibited stability in vivo. We shed light into designing ligand-engineered nanostructures in an external position to facilitate host cell attachment, thereby eliciting regenerative host responses.

Revealing the active nature of oxide derived copper (OD-Cu) is of key importance to understand its remarkable catalytic performance during the cathodic CO2 reduction reaction (CO2RR) to produce valuable hydrocarbons. Using advanced spectroscopy, electron microscopy and electro active surface area characterization techniques, the electronic structure and the changes in the morphology/roughness of thermally oxidized copper thin films were revealed during CO2RR. For this purpose we developed an in situ cell for X-ray spectroscopy able to be operated accurately in the presence of gases or liquids to unite the role of the initial thermal oxide-phase and its active phase during the electrocatalytic reduction of CO2. It was found that the Cu(I) species formed during the thermal treatment are readily reduced to Cu0 during the CO2RR, whereas Cu(II) species are hardly reduced. In addition, Cu(II) oxide electrode dissolution was found to yield a porous/void structure, where the lack of electrical connection between isolated islands prohibits the CO2RR. Therefore, the active/stable phase for CO2RR is metallic copper, independent of its initial phase, with a significant change in its morphology upon its reduction yielding the formation of a rougher surface with higher number of under coordinated sites. Thus, the initial thermal oxidation of copper in air controls the reaction activity/selectivity due to the changes induced in electrode surface morphology/roughness and the presence of more under coordinated sites during the CO2RR.

The development of heat-generating magnetic nanostructures is critical for the effective management of tumors using magnetic hyperthermia. Herein, we demonstrate that polyethylene glycol (PEG)-coated iron oxide (magnetite, Fe3O4) multigranule nanoclusters (PEG-MGNCs) can enhance the efficiency of hyperthermia-based tumor suppression in vitro and in vivo. MGNCs consisting of granules (crystallites) measuring 22.9 nm in diameter were prepared via the hydrothermal polyol method, followed by the surface modification of MGNCs with PEG-dopamine. The freshly prepared PEG-MGNCs exhibit 145.9 ± 10.2 nm diameter on average under aqueous conditions. The three-dimensional structures of PEG-MGNCs enhance the hyperthermic efficacy compared with PEGylated single iron-oxide nanoparticles (NPs), resulting in severe heat damage to tumor cells in vitro. In the SCC7 tumor-bearing mice, near-infrared fluorescence dye (Cy5.5)-labeled PEG-MGNCs are successfully accumulated in the tumor tissues because of NP-derived enhanced permeation and retention effect. Finally, the tumor growth is significantly suppressed in PEG-MGNC-treated mice after two-times heat generation by using a longitudinal solenoid, which can generate an alternating magnetic field under high-frequency (19.5 kA/m, 389 kHz) induction. This study shows for the first time that the PEG-MGNCs greatly enhance the hyperthermic efficacy of tumor treatment both in vitro and in vivo.

Background Neurologic problems after reverse total shoulder arthroplasty (RTSA) have been reported, but there are a lack of studies regarding which nerve(s) are damaged and the outcomes for the patients who had neurologic complications after RTSA. The purpose of this study was to assess the prevalence and outcomes of neurologic deficit after RTSA and to evaluate the correlation between nonanatomic rearrangement of the shoulder joint and neurologic complications after RTSA. We hypothesized that the neurologic deficit was associated with excessive distalization or lateralization of the humerus after RTSA. Methods RTSA was performed on 182 consecutive shoulders with cuff tear arthropathy. Comparative analysis was performed on 34 shoulders with (group 1) and 148 shoulders without (group 2) neurologic deficit. Results The mean follow-up period in the study was 58.5 months (range: 24-124). The mean age was 71.5 ± 7.7 years in group 1 and 73.1 ± 7.2 years in group 2. Neurologic deficit after RTSA was found in 34 shoulders (19%). The mean postoperative acromiohumeral distance was 34.1 ± 11.0 mm in group 1 and 29.4 ± 7.6 mm in group 2 (P = .015). Significant differences in terms of postoperative distalization of the humerus were seen between group 1 (24.5 ± 9.4 mm) and group 2 (20.5 ± 8.3 mm) (P = .009). The most common forms of neurologic deficit after RTSA were axillary nerve (41.2%) and radial nerve (15%) injuries. Thirty shoulders (88%) had neuropraxia, and 4 shoulders (12%) had axonotmesis. By conservative treatment, all patients with neurologic complications achieved complete recovery without any additional surgery; the mean recovery period was 7.4 months (range: 2-38 months). Conclusion Neurologic deficit occurred in 19% of patients who underwent RTSA, and it was significantly correlated with humeral distalization after surgery. Axillary nerve was mostly involved, and all patients with neurologic deficit achieved complete recovery without any additional surgery.

Developing materials with remote controllability of macroscale ligand presentation can mimic extracellular matrix (ECM) remodeling to regulate cellular adhesion in vivo. Herein, we designed charged mobile nanoligands with superparamagnetic nanomaterials amine-functionalized and conjugated with polyethylene glycol linker and negatively charged RGD ligand. We coupled negatively a charged nanoligand to a positively charged substrate by optimizing electrostatic interactions to allow reversible planar movement. We demonstrate the imaging of both macroscale and in situ nanoscale nanoligand movement by magnetically attracting charged nanoligand to manipulate macroscale ligand density. We show that in situ magnetic control of attracting charged nanoligand facilitates stem cell adhesion, both in vitro and in vivo, with reversible control. Furthermore, we unravel that in situ magnetic attraction of charged nanoligand stimulates mechanosensing-mediated differentiation of stem cells. This remote controllability of ECM-mimicking reversible ligand variations is promising for regulating diverse reparative cellular processes in vivo.

Electrochemical CO2 reduction is a potential approach to convert CO2 into valuable chemicals using electricity as feedstock. Abundant and affordable catalyst materials are needed to upscale this process in a sustainable manner. Nickel-nitrogen-doped carbon (Ni-N-C) is an efficient catalyst for CO2 electro-reduction to CO, and the single-site Ni-Nx motif is believed as the active site. However, critical metrics for its catalytic activity, such as active site density and intrinsic turnover frequency, so far lack systematic discussion. In this work, we prepared a set of covalent organic framework (COF)-derived Ni-N-C catalysts, for which the Ni-Nx content could be adjusted by the pyrolysis temperature. The combination of high-angle annular dark-field scanning transmission electron microscopy and extended X-ray absorption fine structure evidenced the presence of Ni single-sites, and quantitative X-ray photoemission addressed the relation between active site density and turnover frequency.

Renal tumors account for approximately 7% of all childhood cancers. These include Wilms tumor (WT), clear cell sarcoma of the kidney (CCSK), malignant rhabdoid tumor (MRTK), renal cell carcinoma (RCC), congenital mesoblastic nephroma (CMN) and other rare tumors. We investigated the epidemiology of pediatric renal tumors in Korea.From January 2001 to December 2015, data of pediatric patients (0-18 years) newly-diagnosed with renal tumors at 26 hospitals were retrospectively analyzed.Among 439 patients (male, 240), the most common tumor was WT (n=342, 77.9%), followed by RCC (n=36, 8.2%), CCSK (n=24, 5.5%), MRTK (n=16, 3.6%), CMN (n=12, 2.7%), and others (n=9, 2.1%). Median age at diagnosis was 27.1 months (range 0-225.5) and median follow-up duration was 88.5 months (range 0-211.6). Overall, 32 patients died, of whom 17, 11, 1, and 3 died of relapse, progressive disease, second malignant neoplasm, and treatment-related mortality. Five-year overall survival and event free survival were 97.2% and 84.8% in WT, 90.6% and 82.1% in RCC, 81.1% and 63.6% in CCSK, 60.3% and 56.2% in MRTK, and 100% and 91.7% in CMN, respectively (p0.001).The pediatric renal tumor types in Korea are similar to those previously reported in other countries. WT accounted for a large proportion and survival was excellent. Non-Wilms renal tumors included a variety of tumors and showed inferior outcome, especially MRTK. Further efforts are necessary to optimize the treatment and analyze the genetic characteristics of pediatric renal tumors in Korea.

Electrochemical CO2 reduction is a potential approach to convert CO2 into valuable chemicals using electricity as feedstock. Abundant and affordable catalyst materials are needed to upscale this process in a sustainable manner. Nickel-nitrogen-doped carbon (Ni-N-C) is an efficient catalyst for CO2 reduction to CO, and the single-site Ni−Nx motif is believed to be the active site. However, critical metrics for its catalytic activity, such as active site density and intrinsic turnover frequency, so far lack systematic discussion. In this work, we prepared a set of covalent organic framework (COF)-derived Ni-N-C catalysts, for which the Ni−Nx content could be adjusted by the pyrolysis temperature. The combination of high-angle annular dark-field scanning transmission electron microscopy and extended X-ray absorption fine structure evidenced the presence of Ni single-sites, and quantitative X-ray photoemission addressed the relation between active site density and turnover frequency.

Metallic barcode nanowires (BNWs) composed of repeating heterogeneous segments fabricated by template-assisted electrodeposition can offer extended functionality in magnetic, electrical, mechanical, and biomedical applications. We can consider such nanostructures as a three-dimensional system of magnetically interacting elements with magnetic behavior strongly affected by complex magnetostatic interactions. This study discusses the influence of geometrical parameters of segments on the character of their interactions and the overall magnetic behavior of the array of BNWs having alternating magnetization. By controlling the applied current densities and the elapsed time in the electrodeposition, we regulate the dimension of the Fe-Au BNWs. We show that the Fe and Au segments are made of Fe-Au alloys with high and low magnetization. With the help of micromagnetic simulations, we discover and analyze the three types of magnetostatic interactions in the BNW arrays. As a result, we demonstrate that the dominating type of interaction depends on the geometric parameters of the Fe and Au segments and the interwire and intrawire distances., Comment: 29 pages, 7 figures

Nature catalysis 5(4), 259 - 267 (2022). doi:10.1038/s41929-022-00760-z, Convoluted selectivity trends and a missing link between reaction product distribution and catalyst properties hinder practical applications of the electrochemical CO$_2$ reduction reaction (CO$_2$RR) for multicarbon product generation. Here we employ operando X-ray absorption and X-ray diffraction methods with subsecond time resolution to unveil the surprising complexity of catalysts exposed to dynamic reaction conditions. We show that by using a pulsed reaction protocol consisting of alternating working and oxidizing potential periods that dynamically perturb catalysts derived from Cu$_2$O nanocubes, one can decouple the effect of the ensemble of coexisting copper species on the product distribution. In particular, an optimized dynamic balance between oxidized and reduced copper surface species achieved within a narrow range of cathodic and anodic pulse durations resulted in a twofold increase in ethanol production compared with static CO$_2$RR conditions. This work thus prepares the ground for steering catalyst selectivity through dynamically controlled structural and chemical transformations., Published by Macmillan Publishers Limited, part of Springer Nature, [London]

Nature energy 7(8), 765 - 773 (2022). doi:10.1038/s41560-022-01083-w, Water electrolysis is a key technology to establish CO$_2$-neutral hydrogen production. Nonetheless, the near-surface structure of electrocatalysts during the anodic oxygen evolution reaction (OER) is still largely unknown, which hampers knowledge-driven optimization. Here using operando X-ray absorption spectroscopy and density functional theory calculations, we provide quantitative near-surface structural insights into oxygen-evolving CoO$_x$(OH)$_y$ nanoparticles by tracking their size-dependent catalytic activity down to 1 nm and their structural adaptation to OER conditions. We uncover a superior intrinsic OER activity of sub-5 nm nanoparticles and a size-dependent oxidation leading to a near-surface Co–O bond contraction during OER. We find that accumulation of oxidative charge within the surface Co$^{3+}$O$_6$ units triggers an electron redistribution and an oxyl radical as predominant surface-terminating motif. This contrasts the long-standing view of high-valent metal ions driving the OER, and thus, our advanced operando spectroscopy study provides much needed fundamental understanding of the oxygen-evolving near-surface chemistry., Published by Nature Publishing Group, London

Depletion of protein phosphatase-1 catalytic subunit beta (PPP1CB), a serine/threonine protein phosphatase and potent adipogenic activator, suppresses the differentiation of 3T3-L1 preadipocytes into mature adipocytes. Therefore, PPP1CB is considered as a potential therapeutic target for obesity. We screened 1033 natural products for PPP1CB inhibitors and identified chebulinic acid, which is abundantly present in the seeds of Euphoria longana and fruits of Terminalia chebula. Chebulinic acid strongly inhibited the hydrolysis of 6,8-difluoro-4-methylumbelliferyl phosphate by PPP1CB (IC50 = 300 nM) and demonstrated potent antiadipogenic effects in 3T3-L1 preadipocytes in a concentration-dependent manner. Additional studies have demonstrated that chebulinic acid suppresses early differentiation by downregulating key transcription factors that control adipogenesis in 3T3-L1 cells. These results suggested that chebulinic acid may be a potential therapeutic agent for treating obesity by inhibiting PPP1CB activity.