Small Degradation Research Articles

Identification of phosphatases that dephosphorylate the co-chaperone BAG3.

The co-chaperone BAG3 plays critical roles in maintaining cellular proteostasis. It associates with 14-3-3 proteins during the trafficking of aggregation-prone proteins and facilitates their degradation through chaperone-assisted selective autophagy in cooperation with small heat shock proteins. Although reversible phosphorylation regulates BAG3 function, the involved phosphatases remain unknown. Here, we used affinity purification mass spectrometry to identify phosphatases that target BAG3. Of the hits, we evaluated the involvement of protein phosphatase-1 (PP1) using chemical inhibitors and activators in in vitro and cellular approaches. Our results demonstrate that PP1 can dephosphorylate BAG3-pS136 in cells and counteract 14-3-3γ association with BAG3 at this motif. Furthermore, protein phosphatase-5 (PP5) co-enriched with proteostasis-related proteins, and it has the capacity to dephosphorylate a BAG3 phosphorylation-site cluster regulating the interaction of BAG3 with small heat shock proteins and BAG3-mediated protein degradation. Our findings provide new insights into the regulation of BAG3 by phosphatases. This paves the way for future research focused on the precise control of BAG3 function through its regulatory proteins, potentially holding therapeutic promise for diseases characterized by disrupted proteostasis.

Modeling of FAK-PROTAC candidates from GSK2256098 analogs for targeted protein degradation

Protein inhibition via the traditional drug-designing approach has been shown to be an effective method for developing numerous small-molecule-based therapeutics. In the last decade, small inhibitors-guided protein degradation has arisen as an alternative method with the potential to fulfill the drug requirement for undruggable targets. Focal adhesion kinase (FAK) is a crucial modulator of the growth and spread of tumors, apart from it also acts as a scaffold for signaling of other proteins. FAK inhibitors have thus far had unsatisfactory results in clinical trials for cancer applications. Unlike prior attempts to control FAK expression, which were restricted to kinase domain inhibition with limited success in clinical research, protein degradation has the potential to concurrently disrupt FAK's kinase and scaffolding function. Recently, several FAK degraders were reported based on FAK Type I inhibitors using complex chemical synthesis approaches. Interestingly, recently a ternary complex was published revealing the binding mode of the FAK-PROTAC-E3 complex. This complex opens an avenue for the development of rational PROTAC design against FAK protein. Therefore, in the present study, we selected the most active Type I FAK inhibitor GSK2256098. The binding mode of the inhibitor prompted us to identify the most suitable analog for PROTAC design. We have identified a high-affinity analog that is suitable for PTOTAC design through the application of molecular docking (MD) and molecular dynamics simulations (MDS). Further based on the ternary FAK-PROTAC-E3 complex we build a binary complex FAK-Hit-E3-VHL between both proteins. Using the structure-based approach ten different potential FAK PROTACs candidates were designed. The stability of the complexes was analyzed using MDS and binding free energies were used to predict the binding affinity. Finally, based on desirable intermolecular interactions with the target and E3 ligase ProTAC4 was selected as the best candidate when compared with known FAK PROTAC GSK215.

Multiplexed profiling of intracellular protein abundance, activity, interactions and druggability with LABEL-seq.

Here we describe labeling with barcodes and enrichment for biochemical analysis by sequencing (LABEL-seq), an assay for massively parallel profiling of pooled protein variants in human cells. By leveraging the intracellular self-assembly of an RNA-binding domain (RBD) with a stable, variant-encoding RNA barcode, LABEL-seq facilitates the direct measurement of protein properties and functions using simple affinity enrichments of RBD protein fusions, followed by high-throughput sequencing of co-enriched barcodes. Measurement of ~20,000 variant effects for ~1,600 BRaf variants revealed that variation at positions frequently mutated in cancer minimally impacted intracellular abundance but could dramatically alter activity, protein-protein interactions and druggability. Integrative analysis identified networks of positions with similar biochemical roles and enabled modeling of variant effects on cell proliferation and small molecule-promoted degradation. Thus, LABEL-seq enables direct measurement of multiple biochemical properties in a native cellular context, providing insights into protein function, disease mechanisms and druggability.

Design and Evaluation of a Weighted Periodic Sparse Array for Low-Complexity 1-D Phased Array Ultrasound Imaging Systems.

A sparse array offers a significant reduction in the complexity of ultrasonic imaging systems by decreasing the number of active elements and associated electrical circuits needed to form a focused beam. Consequently, for 1-D arrays, it has been adopted in the development of miniaturized systems such as portable, handheld, or smartphone-based systems. Previously, we developed an analytic method that can design a pair of 1-D periodic sparse arrays (PSAs) satisfying three specific constraints, which are the array size, desired grating lobe level, and sparseness factor (SF). In this study, we further developed our method by incorporating aperture weighting functions, which take the form of tapered rectangular functions to introduce null points on the beam pattern. These null points effectively suppress grating lobes generated by a matching pair of arrays. The design process commences with determining transmit and receive PSA patterns, followed by deriving corresponding aperture weighting functions. First, aperture functions of a base and weighting arrays are convolved, which is then upsampled to the targeted array size. Finally, the upsampled aperture is convolved to an aperture function of a subarray, resulting in weighted PSAs (wPSAs). Pulsed wave (PW) simulation confirmed improved grating lobe suppression with wPSAs compared to PSAs. Phantom imaging experiments using a 1-D phased array validated the enhanced contrast due to suppressed grating lobes but at the cost of small degradation in lateral resolution. The signal-to-noise ratio (SNR) also gradually declined with the greater SFs, but no significant difference in SNR was observed between wPSAs and PSAs. Finally, in vivo echocardiography imaging highlighted the clinical potential of wPSAs, particularly with high SFs. Overall, these results suggest that wPSAs can effectively enhance contrast compared to PSAs under the given SF or, alternatively, wPSA with greater SFs can achieve comparable image quality to PSAs with lower SFs. In conclusion, the wPSA approach holds promise for further reducing the complexity of ultrasound imaging systems.

Quality indexes of land ownership and land cover as indicators of small lake catchment degradation

Changes in land ownership, generally resulting in changes in land cover and progressive fragmentation of catchments, often result in the inability to take pro-environmental measures. The aim of this paper is to assess the impact of land ownership on the environmental status of small, but environmentally valuable lake catchments. The study of environmental quality in terms of ownership and land cover was conducted in lake catchments located in the central part of the West Polesie Transboundary Biosphere Reserve. In total, the ownership type was determined for 5661 plots and the land cover type was determined for 2502 subdivisions. The quality of the analysed elements of the study catchments was subjected to expert evaluation using a modified Stapel Scale and was presented using two Qualitative Indexes proposed: Land Cover [Lc] and Land Ownership [Lo]. The obtained values of Index Lc ranged from −0.18 to +1.97, and Index Lo from −1.87 to +2.00. Application of the Average Land Quality Index [LQ], in turn, made it possible to randomise the environmental quality of the analysed catchments, for which it was from −1.02 to +1.99 (areas of very good and very poor environmental quality, respectively). The analyses indicated, for example, catchments that were significantly degraded because of a very large number of private plots in their area − in the five analysed catchments, this ranged from 505 to 719 and their average area was 0.19–1.10 ha. It is noteworthy that very unfavourable land ownership conditions and land cover structure were found in the Poleski National Park catchments – the area with the highest protection status. The proposed assessment system can be used for preliminary analysis of actual and potential threats to lake catchments so as to indicate possible directions of conservation measures and their sensibility.

CLOCI: unveiling cryptic fungal gene clusters with generalized detection.

Gene clusters are genomic loci that contain multiple genes that are functionally and genetically linked. Gene clusters collectively encode diverse functions, including small molecule biosynthesis, nutrient assimilation, metabolite degradation, and production of proteins essential for growth and development. Identifying gene clusters is a powerful tool for small molecule discovery and provides insight into the ecology and evolution of organisms. Current detection algorithms focus on canonical 'core' biosynthetic functions many gene clusters encode, while overlooking uncommon or unknown cluster classes. These overlooked clusters are a potential source of novel natural products and comprise an untold portion of overall gene cluster repertoires. Unbiased, function-agnostic detection algorithms therefore provide an opportunity to reveal novel classes of gene clusters and more precisely define genome organization. We present CLOCI (Co-occurrence Locus and Orthologous Cluster Identifier), an algorithm that identifies gene clusters using multiple proxies of selection for coordinated gene evolution. Our approach generalizes gene cluster detection and gene cluster family circumscription, improves detection of multiple known functional classes, and unveils non-canonical gene clusters. CLOCI is suitable for genome-enabled small molecule mining, and presents an easily tunable approach for delineating gene cluster families and homologous loci.

Towards Application Centric Carbon Emission Management

Carbon emissions are due to application execution on a target system (operational emissions) and the production, transportation, and disposal of the system itself (embodied emissions). This paper investigates the impacts of different resource configurations in terms of available DRAM memory on the overall carbon emission of individual application executions. We first propose an application-centric carbon footprint model that considers DRAM and CPU. We then study the model using a widely-used key-value store (RocksDB) and Graph500 applications. The results for RocksDB indicate that the minimal emission configuration is application dependent and can lead to significant emission reductions compared to application-oblivious configurations that use higher DRAM capacity without improving performance. For some applications, small performance degradation may lead to substantial additional emission reductions.

A new approach for synthesis of bismuth oxide derived photocatalyst for degradation of para nitrophenol

More focus has recently been placed on achieving the sustainable development objectives by 2030. As water is important and ha many purposes, it is important to have clean water. The inefficiency of different water treatment techniques restricts their widespread implementation. Furthermore, some of the procedures readily create secondary pollutants. As a result, it is critical to develop an effective and ecologically beneficial method of converting organic contaminants into non-toxic and harmless chemicals. A modified hydrothermal synthesis method was utilised for successfully producing Bi2O3 nanoparticles in this research. Fourier Transform Infrared (FT-IR) spectroscopy, X-Ray Diffraction (XRD), Scanning Electron Microscopy, and Energy Dispersive X-Ray were used to characterise and to find the structural, optical, morphological, and compositional aspects of the formed nanoparticles. Moreover, the formed particles were used to degrade the noxious Para-nitrophenol (PNP). PNP deterioration was performed under 3 different conditions: under halogen light, under sunlight and in the dark. The experiment showed that halogen irradiation showed better result. Due to PNP adsorption on Bi2O3, even without irradiation, a small degradation was detected but in just over an hour, under halogen light the catalyst destroyed 99.23 % of 4-nitrophenol. We also used natural lighting in our degradation studies. Natural daylight deterioration efficiency was 63.26 %. The nanoparticles that were formed turned out to be an excellent photocatalyst for the degradation of PNP in wastewater.

Enhancing sp3 content in diamond-like carbon thin film electrodes by pulsed laser annealing for durable charge storage performance

In this work, diamond-like carbon (DLC) thin film electrodes were grown on Si substrate by pulsed laser deposition (PLD) technique, and the implication of pulsed laser annealing (PLA) treatment on their electrochemical supercapacitor performance was examined by three electrode systems in 1 M Na2SO4 electrolyte solutions. The SEM micrographs exhibit a sheet-like wrinkled surface of DLC film on Si which later transformed into tiny hierarchical heap-like structures with enhanced surface roughness. The Raman spectra confirm signature of the D and G peaks of pristine DLC film at ∼1352 cm−1 (1356 cm−1 after PLA) and 1591 cm−1 (1589 cm−1 after PLA), and appearance of minor T2g (diamond) (1332 cm−1) peaks with an increment of the sp3 content after PLA treatment. The X-ray photoelectron spectroscopy (XPS) spectra were deconvoluted into three different contributions CC (sp2), CC (sp3), and CO, and their sp3 percentages were estimated ∼48.9 %, and 64.7 % before and after annealing. The area under cyclic voltammetry (CV) curve and galvanostatic charging discharging (GCD) performance of PLA-treated DLC film were improved and the highest areal-specific capacitance was obtained to be ∼48.25 mF/cm2 for scan rate of 5 mV/s and 36.01 mF/cm2 for current density of 2 mA/cm2, respectively. Excellent charging discharging cyclic stability of PLA treated electrode was observed over 5000 cycles, and Coulombic efficiency and capacitance retention were determined to be ∼93.5 % and ∼ 97.3 %, respectively. The electrochemical impedance spectroscopy (EIS) was performed to obtain the Nyquist plot (Z′vs.Z′′) of both electrodes before and after the stability test, and a small degradation in impedance was observed. The Nyquist plots were fitted with the well-known Randles equivalent circuit model Rs(Cdl(RctZw)) and substantial curtailment of Warburg resistance (Zw) in PLA-induced DLC electrode signifies the dominance of the diffusion-controlled region in the charging-discharging process. Minor changes in the Nyquist plot before and after the stability test manifest the enduring charge kinetics of both electrodes and PLA-treated DLC exhibits better cyclic stability. PLA techniques have a great impact on upgrading the areal-specific capacitance, capacitance retention with high Coulombic efficiency, and stability with negligible impedance loss of the DLC film electrodes.

Seismic behavior of precast segmental bridge columns confined by grouted glass fiber reinforced plastic tubes

The application of precast segmental bridge columns (PSBCs) is still restricted in seismicity areas due to concerns such as lower lateral stiffness and column base bearing capacity. To enhance the applicability of PSBCs, this study proposed a novel approach of confining them with grouted GFRP tubes. Four novel and one reference specimens were tested under low cyclic loading to evaluate the effects of energy dissipation (ED) bars ratios, concrete interlayer strength, type of segment concrete, and concrete pouring methods within the outer GFRP tube (OGT) on the seismic behavior. Experimental results reveal that the failure modes of all specimens were triggered by the yielding of ED bars and the break of OGT at the top of ED bars. No crushed concrete at column bases or cracks at the segment joint were observed during the test due to the good confinement of GFRP tubes. All the specimens exhibited stable hysteretic behavior with small residual drift ratios and low strength degradation. Furthermore, finite element models (FEMs) were generated to predict the hysteretic behavior of novel specimens. The effects of some parameters such as OGT thickness, ED bars diameter, and concrete strength were further studied.

Enhancing Ni/Co Activity by Neighboring Pt Atoms in NiCoP/MXene Electrocatalyst for Alkaline Hydrogen Evolution

AbstractDensity functional theory (DFT) calculations demonstrate neighboring Pt atoms can enhance the metal activity of NiCoP for hydrogen evolution reaction (HER). However, it remains a great challenge to link Pt and NiCoP. Herein, we introduced curvature of bowl‐like structure to construct Pt/NiCoP interface by adding a minimal 1 ‰‐molar‐ratio Pt. The as‐prepared sample only requires an overpotential of 26.5 and 181.6 mV to accordingly achieve the current density of 10 and 500 mA cm−2 in 1 M KOH. The water dissociation energy barrier (Ea) has a ~43 % decrease compared with NiCoP counterpart. It also shows an ultrahigh stability with a small degradation rate of 10.6 μV h−1 at harsh conditions (500 mA cm−2 and 50 °C) after 3000 hrs. X‐ray photoelectron spectroscopy (XPS), soft X‐ray absorption spectroscopy (sXAS), and X‐ray absorption fine structure (XAFS) verify the interface electron transfer lowers the valence state of Co/Ni and activates them. DFT calculations also confirm the catalytic transition step of NiCoP can change from Heyrovsky (2.71 eV) to Tafel step (0.51 eV) in the neighborhood of Pt, in accord with the result of the improved Hads at the interface disclosed by in situ electrochemical impedance spectroscopy (EIS) and scanning electrochemical microscopy (SECM) tests.

Enhancing Ni/Co Activity by Neighboring Pt Atoms in NiCoP/MXene Electrocatalyst for Alkaline Hydrogen Evolution.

Density functional theory (DFT) calculations demonstrate neighboring Pt atoms can enhance the metal activity of NiCoP for hydrogen evolution reaction (HER). However, it remains a great challenge to link Pt and NiCoP. Herein, we introduced curvature of bowl-like structure to construct Pt/NiCoP interface by adding a minimal 1 ‰-molar-ratio Pt. The as-prepared sample only requires an overpotential of 26.5 and 181.6 mV to accordingly achieve the current density of 10 and 500 mA cm-2 in 1 M KOH. The water dissociation energy barrier (Ea) has a ~43 % decrease compared with NiCoP counterpart. It also shows an ultrahigh stability with a small degradation rate of 10.6 μV h-1 at harsh conditions (500 mA cm-2 and 50 °C) after 3000 hrs. X-ray photoelectron spectroscopy (XPS), soft X-ray absorption spectroscopy (sXAS), and X-ray absorption fine structure (XAFS) verify the interface electron transfer lowers the valence state of Co/Ni and activates them. DFT calculations also confirm the catalytic transition step of NiCoP can change from Heyrovsky (2.71 eV) to Tafel step (0.51 eV) in the neighborhood of Pt, in accord with the result of the improved Hads at the interface disclosed by in situ electrochemical impedance spectroscopy (EIS) and scanning electrochemical microscopy (SECM) tests.

Abstract 5941: Small molecule NSC59984 synergizes with PARP inhibitors in BRCA1 wild type ovarian cancer

Abstract PARP inhibitors (PARPi) targeting poly (ADP-ribose) polymerase are the first clinically approved drugs designed to apply synthetic lethality in BRCA1 mutant/deficient cancer. However, the treatment can cause reversion of BRCA mutation which results in drug resistance. To explore new strategies to improve antitumor efficacy of PARPi, we applied PARPi in combination with a small molecule NSC59984 for cancer therapy. NSC59984 is a small molecular targeting mutant p53 degradation and activating p73 via ROS-ERK2-MDM2 pathway. The treatments with radiation or hydrogen peroxide showed that NSC59984 enhanced DNA comet tails and gamma-H2AX, correlated to reduction of rad51 foci in cancer cells. These results suggest that NSC59984 impairs DNA damage repair via abrogation of homologous recombination (HR). We further applied the combinational treatment of NSC59984 and PARPi in BRCA1 wild-type ovarian cancer cells and found that NSC59984 synergized with PARPi to reduce cell viability, inhibit colony formation, and increase cell death. The combination treatment enhanced DNA damage and correlated with reduction of BRCA1 at the protein level. These results, taken together, suggest that the induction of BRCAness causes a synthetical lethality with PARPi in BRCA1 wild-type cancer cells. Cell cycle profiling showed that the cells were arrested at the G2/M phase in response to combinational treatment. At the G2 phase arrest, the high doses of the combinational drugs led to cell death via mitotic catastrophe, and the intermediate doses induced cellular senescence defined by senescence phenotypic hallmarks including senescence-associated beta-gal staining and a secretome consistent with senescence-associated secretory phenotype (SASP). Therapy-induced senescence (TIS) in cancer cells is considered as one of the mechanisms of tumor recurrence and drug resistance. To reduce the risk of TIS in treatment, we applied senolytic treatment to target senescent cells in the combinational treatment. The senolytic drug ABT263 treatment eliminated the senescent cancer cells from the combinational treatment. ABT263, NSC59984 + PARPi combinational treatment further reduced cell viability. Our study provides a rationale for small molecular compounds targeting HR deficiency in combination with PARPi to treat BRCA1wild-type ovarian cancer cells, and additional senolytic treatment may be required to limit resistance by removal of the TIS. Citation Format: Shengliang Zhang, Lanlan Zhou, Leiqing Zhang, Maximilian Pinho-Schwermann, Benedito Carneiro, John Sedivy, Wafik S. El-Deiry. Small molecule NSC59984 synergizes with PARP inhibitors in BRCA1 wild type ovarian cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5941.

Structural basis of ribosomal 30S subunit degradation by RNase R.

Protein synthesis is a major energy-consuming process of the cell that requires the controlled production1-3 and turnover4,5 of ribosomes. Although the past few years have seen major advances in our understanding of ribosome biogenesis, structural insight into the degradation of ribosomes has been lacking. Here we present native structures of two distinct small ribosomal 30S subunit degradation intermediates associated with the 3' to 5' exonuclease ribonuclease R (RNase R). The structures reveal that RNase R binds at first to the 30S platform to facilitate the degradation of the functionally important anti-Shine-Dalgarno sequence and the decoding-site helix 44. RNase R then encounters a roadblock when it reaches the neck region of the 30S subunit, and this is overcome by a major structural rearrangement of the 30S head, involving the loss of ribosomal proteins. RNase R parallels this movement and relocates to the decoding site by using its N-terminal helix-turn-helix domain as an anchor. In vitro degradation assays suggest that head rearrangement poses a major kinetic barrier for RNase R, but also indicate that the enzyme alone is sufficient for complete degradation of 30S subunits. Collectively, our results provide a mechanistic basis for the degradation of 30S mediated by RNase R, and reveal that RNase R targets orphaned 30S subunits using a dynamic mechanism involving an anchored switching of binding sites.

Ceramic-to-metal bonding using rare-earth containing Sn–Bi solder

With the increasing miniaturization and power of optoelectronic devices, direct bonding of optical substrates like semiconductors and ceramics to metal heat sinks using low melting-point solder has gained significant interest. In this study, we demonstrated the bonding of glass to copper using Sn-58 wt% Bi solder (SB solder) doped with a small amount of rare earth (RE) elements. The RE elements act as active agents that facilitate the bonding to glasses without glass metallization. By optimizing the bonding parameters, such as reflow temperature and time, and employing an inert gas atmosphere to prevent solder or RE oxidation, we successfully achieved the highest shear strength in glass-copper solder joints using SB-RE solder, without the need for ultrasonic-assisted soldering (UAS). These results demonstrate the potential of using RE-containing solder for bonding unmetallized glass and ceramics in optoelectronic devices with metals at low soldering temperatures (< 200 °C). Furthermore, analysis of the shear strength and failure morphology of solder joints revealed only small degradation, primarily originating from the bulk solder region rather than the solder-glass interface, after both thermal aging (100 h) and cycling tests (100 cycles). The establishment of low-melting point RE-containing solders opens the possibility of direct jointing ceramic optoelectronic substrates to metal heat sinks for more efficient heat dissipation. In the meantime, our work also suggests that further optimization studies are necessary to explore its performance under more extreme working conditions.

A SUMO E3 ligase promotes long non-coding RNA transcription to regulate small RNA-directed DNA elimination.

Small RNAs target their complementary chromatin regions for gene silencing through nascent long non-coding RNAs (lncRNAs). In the ciliated protozoan Tetrahymena, the interaction between Piwi-associated small RNAs (scnRNAs) and the nascent lncRNA transcripts from the somatic genome has been proposed to induce target-directed small RNA degradation (TDSD), and scnRNAs not targeted for TDSD later target the germline-limited sequences for programmed DNA elimination. In this study, we show that the SUMO E3 ligase Ema2 is required for the accumulation of lncRNAs from the somatic genome and thus for TDSD and completing DNA elimination to make viable sexual progeny. Ema2 interacts with the SUMO E2 conjugating enzyme Ubc9 and enhances SUMOylation of the transcription regulator Spt6. We further show that Ema2 promotes the association of Spt6 and RNA polymerase II with chromatin. These results suggest that Ema2-directed SUMOylation actively promotes lncRNA transcription, which is a prerequisite for communication between the genome and small RNAs.

(Invited) Metal Oxide Nanoparticles for Stable Alkaline Oxygen Evolution Reaction in an Anion Exchange Membrane Electrolyser Cell

One of the key challenges to develop efficient water electrolysis system is to find effective and robust electrocatalysts for the oxygen evolution reaction (OER). Mixed transition metal oxides provide immense possibilities for such purpose.1 , 2 Abundant catalytically active sites could be generated via engineering the defects and oxygen vacancies within the transition metal oxides.3 The catalyst stability could also be improved by incorporating self-healing component into the catalysts .4 In this work, we adopt cobalt oxides as substrate materials to prepare mixed transition metal oxides. The catalysts are synthesized via a combined approach of hydrothermal and annealing processes. The final products are characterized thoroughly by a broad range of characterization techniques, including XRD, TEM, SEM, EDX, and XPS. The OER activities are initially evaluated in a three-electrode system. The results show that the as-prepared catalysts demonstrate high current density at a relatively low overpotential. Moreover, the catalysts exhibit excellent robustness for an 8-hours stability test in a three-electrode testing system. The stability and activity of the catalysts is further assessed in a lab-scale anion exchange membrane (AEM) electrolyser cell setup. Only a small degradation is observed for the best performing catalyst in 12 hours period. The details of the catalyst characterization and electrochemical measurements will be discussed. Acknowledgements This work was funded by European Union’s Horizon 2020 projects FlowPhotoChem (Grant agreement number 862453) and European Innovation Council Pathfinder ANEMEL (Grant agreement number 101071111). References Mohammed-ibrahim, J. & Moussab, H. Tuning the electronic structure of the earth-abundant electrocatalysts for oxygen evolution reaction (OER) to achieve efficient alkaline water splitting – A review. J. Energy Chem. 56, 299–342 (2021).Plevová, M., Hnát, J. & Bouzek, K. Electrocatalysts for the oxygen evolution reaction in alkaline and neutral media. A comparative review. J. Power Sources 507, (2021).Zhang, R. et al. Tracking the Role of Defect Types in Co3O4 Structural Evolution and Active Motifs during Oxygen Evolution Reaction. J. Am. Chem. Soc. (2023) doi:10.1021/JACS.2C10515.Silva, A. L. et al. Mn-doped Co3O4 for acid, neutral and alkaline electrocatalytic oxygen evolution reaction. RSC Adv. 12, 26846–26858 (2022).

Design and Joint Control of a Conjoined Biplane and Quadrotor

Unmanned Aerial Vehicles (UAVs) have the potential to perform many different missions, some of which may require a large aircraft for endurance and a small aircraft for maneuverability in wind gusts or cluttered environments such as buildings. This paper proposes a novel combination of a quadrotor and a hybrid biplane capable of joint hover, joint forward flight, and mid-air separation followed by separate flight. We investigate cooperative control strategies during joint flight that do not require any communication between the quadcopter and the biplane. This means that the two aircraft have their own independent control strategy based on their own sensors. The biplane, which is the largest of the two with most control authority, leads the flight and the goal for the quadrotor is to help in producing thrust and increasing rotational stability. Three control strategies for the quadrotor are compared: a proportional angular rate damper, a proportional angular acceleration damper, and constant thrust without attitude control. Simulation and practical tests show that for desired attitude changes of the biplane, the quadrotor rate- and angular acceleration damper strategies lead to a small performance degradation. However, the angular rate damper strategy reduces the roll angle error in disturbance rejection experiments and requires the smallest input command. The in-flight release is successfully tested in joint hover up to a forward pitch angle of −18∘.

Flexible micro-supercapacitors with organic gel electrolytes based on screen-printable CuO-ink

In recent years, due to the increase in the demand for miniaturized devices, there has been a massive increase in research to develop flexible, thin and scalable rechargeable energy storage micro-devices. Micro-supercapacitors (MSCs) with high charge-discharge rates and power density are excellent options for small, lightweight, easy-to-incorporate, flexible energy storage devices. However, the main problem with modern MSCs is their low energy density and money-intensive, time taking, sophisticated construction methods. Screen-printing is a simple, cost-effective and scalable method for fabricating MSCs. Using silver as the current collector, copper oxide as the active material, and gel electrolyte, we present a screen-printable method for constructing flexible MSCs on a PET substrate. The printed MSC was found to give 10.13 mA h cm−3 of volumetric specific capacity and energy density of 10.1 mW h cm−3 with an excellent stability of 99.5% over 3000 cycles and very small capacity degradation even with 120° bending deformation, suggesting outstanding mechanical flexibility and operation stability. Additionally, by connecting numerous MSC devices in series and parallel, the output voltage and current are intelligently adjusted to meet the requirements of varied applications. This study offers an efficient and economical approach to generate MSCs characterized by a substantial energy density. This breakthrough opens avenues for incorporating these MSCs into upcoming wearable technologies.

Experimental testing of GCr15 bearing steel with different surface treatments as passive friction energy-dissipative shims

The seismic performance of buildings can be improved by adding supplemental damping using friction dampers. The friction behavior of the metallic shims becomes more stable with increasing surface hardness ratio between the friction pair. However, as hardness increases, metallic materials tend to become more brittle, which increases the risk of accidental failure. This study investigated the performance of a friction energy dissipator using bearing steel (GCr15) treated by a grinding-strengthening process, a special manufacturing technology for bearings steel commonly used in mechanical engineering. Two base materials, Q355 and B450, were additionally compared with GCr15. Each base material used three different surface treatments, i.e., cleaned surface (CS), sand-blasting (SB), and grinding-strengthen (GS) treatments. The surface hardness of Q355-GS, B455-GS, and GCr15-GS increased by 13.62 %, 17.38 %, and 19.71% compared to their base materials, while sand-blasting didn’t have an increased effect on surface hardness. The nine specimens were quasi-statically tested to investigate the effect of surface treatment on the friction behavior of the metallic shims. For the three Q355-like and three B450-like specimens, the wear mechanism mixed abrasive and adhesive wear. The GCr15-CS experienced contact fatigue failure, while the GCr15-SB and GCr15-GS exhibited abrasive wear resulting in standard rectangular hysteretic loops with a high degree of coincidence. The friction performance of GCr15-GS was the best among the nine friction shims, because it has less loss in friction coefficient and strength during fatigue loading, the least fluctuation in bolt force, and the smallest degradation and coefficient of variation in friction strength.