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ACS Omega May 2024Platinum nanoparticles loaded on a nitrogen-doped carbon nanotubes exhibit a brilliant hydrogen evolution reaction (HER) in an alkaline solution, but their bifunctional...
Platinum nanoparticles loaded on a nitrogen-doped carbon nanotubes exhibit a brilliant hydrogen evolution reaction (HER) in an alkaline solution, but their bifunctional hydrogen and oxygen evolution reaction (OER) has not been reported due to the lack of a strong Pt-C bond. In this work, platinum nanoparticles bonded in carbon nanotubes (Pt-NPs-bonded@CNT) with strong Pt-C bonds are designed toward ultralow overpotential water splitting ability in alkaline solution. Benefit from the strong interaction between platinum and high conductivity carbon nanotube substrates through the Pt-C bond also the platinum nanoparticles bonded in carbon nanotube can provide more stable active sites, as a result, the Pt-NPs-bonded@CNT exhibits excellent hydrogen evolution in acid and alkaline solution with ultralow overpotential of 0.19 and 0.23 V to reach 1000 mA cm, respectively. Besides, it shows superior oxygen evolution electrocatalysis in alkaline solution with a low overpotential of 1.69 V at 1000 mA cm. Furthermore, it also exhibits high stability over 110 h against the evolution of oxygen and hydrogen at 1000 mA cm. This strategy paves the way to the high performance of bifunctional electrocatalytic reaction with extraordinary stability originating from optimized electron density of metal active sites due to strong metal-substrate interaction.
PubMed: 38764639
DOI: 10.1021/acsomega.4c01662 -
Orthopaedics & Traumatology, Surgery &... Dec 2023Although an autogenous graft has the highest rate of bone union to fill the void created in medial opening wedge high tibial osteotomy (MOWHTO), it also has some...
Better clinical outcomes and faster weight bearing after medial opening-wedge high tibial osteotomy using allogeneic than synthetic graft: A secondary analysis of a Francophone Arthroscopy Society Symposium.
INTRODUCTION
Although an autogenous graft has the highest rate of bone union to fill the void created in medial opening wedge high tibial osteotomy (MOWHTO), it also has some disadvantages, such as prolonged surgical time, donor site pain and morbidity. Two possible candidates for ideal grafts to replace autogenous grafts are allogeneic and synthetic graft, which are free from donor site pain and morbidity. However, previous reports comparing the clinical results of allogeneic to synthetic graft have been limited and controversial. The purpose of this study is to compare radiological findings and clinical outcomes of using synthetic versus allogenic graft to fill the void created in MOWHTO.
HYPOTHESIS
The present clinical study hypothesized that allogenic graft to fill the void would allow the higher rate of bone union and better clinical outcomes.
MATERIAL AND METHODS
This study compared the clinical and radiological outcomes of 95 patients who received MOWHTO to fill the void with either synthetic or allogenic graft (44 in Syn group, 51 in Allo group). Preoperatively and postoperatively, all patients were clinically evaluated; Return to work, Tegner activity score, and the Western Ontario and Macmaster University scores were reported. Radiographically, osteoarthritis grade and pre- and postoperative parameters were reported, including Hip-knee-ankle angle, mechanical lateral distal femoral angle, medial proximal tibial angle, joint line convergence angle, proximal posterior tibial angle, and limb length discrepancy. Perioperative details and complications were also reported.
RESULTS
Mean follow-up (months) were 24.0±1.3 in Syn group and 26.8±1.2 in Allo group (p=0.13). The postoperative improvement of pain and global WOMAC scores in Allo group were significantly better than in Syn group (ΔPain of WOMAC: Syn group 27.8±4.4, Allo group 49.3±3.8, p value <0.001*) (ΔGlobal score of WOMAC: Syn group 16.7±3.2, Allo group 37.4±4.9, p value=0.002*). The risk of hinge fracture in Syn group was significantly higher than in Allo group (Hinge fracture by Takeuchi grade (0/1/2/3): Syn group 37/3/3/1, Allo group 43/8/0/0, p value=0.04*). The timing of full weight bearing in Allo group was significantly earlier than in Syn group (Weight Bearing (1=FWB, 2=PWB 3wk, 3=PWB 6wk): Syn group 2.7±0.1, Allo group 2.3±0.1, p value=0.01*).
DISCUSSION
The use of allogenic graft to fill the void in MOWHTO does not show superiority in bone union compared to synthetic graft, however it improves pain, function, decreases the risk of hinge fracture and allows faster weight bearing than synthetic graft.
LEVEL OF PROOF
III; Case-control study.
Topics: Humans; Osteoarthritis, Knee; Case-Control Studies; Arthroscopy; Retrospective Studies; Knee Joint; Tibia; Fractures, Bone; Osteotomy; Weight-Bearing; Pain; Hematopoietic Stem Cell Transplantation
PubMed: 37813331
DOI: 10.1016/j.otsr.2023.103700 -
Science Advances Jul 2023Large-scale deployment of proton exchange membrane (PEM) water electrolyzers has to overcome a cost barrier resulting from the exclusive adoption of platinum group metal...
Large-scale deployment of proton exchange membrane (PEM) water electrolyzers has to overcome a cost barrier resulting from the exclusive adoption of platinum group metal (PGM) catalysts. Ideally, carbon-supported platinum used at cathode should be replaced with PGM-free catalysts, but they often undergo insufficient activity and stability subjecting to corrosive acidic conditions. Inspired by marcasite existed under acidic environments in nature, we report a sulfur doping-driven structural transformation from pyrite-type cobalt diselenide to pure marcasite counterpart. The resultant catalyst drives hydrogen evolution reaction with low overpotential of 67 millivolts at 10 milliamperes per square centimeter and exhibits no degradation after 1000 hours of testing in acid. Moreover, a PEM electrolyzer with this catalyst as cathode runs stably over 410 hours at 1 ampere per square centimeter and 60°C. The marked properties arise from sulfur doping that not only triggers formation of acid-resistant marcasite structure but also tailors electronic states (e.g., work function) for improved hydrogen diffusion and electrocatalysis.
PubMed: 37406120
DOI: 10.1126/sciadv.adh2885 -
The Review of Scientific Instruments Oct 2023A detailed description of the Langmuir probe system on Mega Ampere Spherical Tokamak Upgrade is presented. The system features 850 tile-embedded probes and 40 bespoke...
A detailed description of the Langmuir probe system on Mega Ampere Spherical Tokamak Upgrade is presented. The system features 850 tile-embedded probes and 40 bespoke electronic modules that each have the capability to drive and acquire data from up to 16 probes in a time-multiplexed manner. The system provides spatiotemporal-resolved measurements (1 cm and ∼1 ms, respectively) in the divertor region of ion saturation current, electron temperature, and floating potential. The standard interpretation of current-voltage (IV) characteristics is to apply a four-parameter fit, based on unmagnetized probe theory, which includes a linear model for the ion saturation region. To mitigate the effect of the magnetic field, analysis is restricted to the region of the IV characteristic, which is sensitive to only the tail of the electron energy distribution function.
PubMed: 37782217
DOI: 10.1063/5.0152680 -
Orthopaedics & Traumatology, Surgery &... Dec 2023Osteochondral lesions of the talar dome (OLTD) are most often found in patients for whom the return to sports activities is the main issue. Two types of surgery have...
INTRODUCTION
Osteochondral lesions of the talar dome (OLTD) are most often found in patients for whom the return to sports activities is the main issue. Two types of surgery have been distinguished at present, bone marrow stimulation techniques and mosaicplasty techniques. The size of the lesion indicating the need for bone marrow stimulation as the required surgical procedure has recently been decreased (<1cm). The main objective of this study was therefore to evaluate the return to sport after OLTD surgery. Our hypothesis is that surgery of osteochondral lesions of the talar dome allows the resumption of sports activities in the majority of cases.
MATERIAL AND METHODS
This multicenter prospective study was conducted across 10 French centers specializing in foot and ankle surgery. All patients aged 18 to 65 with symptomatic OLTD resistant to thorough medical treatment for at least 6 months, justifying surgery, were included from June 2018 to September 2019. In addition to the usual demographic data, the practice of sport and level (professional, competitive, leisure) were systematically investigated preoperatively. A common protocol for surgical management and postoperative follow-up had previously been established according to the arthrographic stage of the lesion. The most recent recommendations based on size, but also depth, were taken into account. The primary endpoint was return to sport.
RESULTS
A final functional evaluation with the AOFAS (American Orthopedic Foot & Ankle Society) score was performed at a minimum of 12 months. Of 58 sports patients, 70.6% returned to sport (41/58) with an average delay of 4.3 months. A high AOFAS functional score (p=0.02) and a stage 1 lesion (p=0.006) were the only preoperative criteria significantly associated with a return to sport. No other factor was predictive of a return to sport.
CONCLUSION
Our prospective study shows that 70.6% of sports patients returned to sport after OLTD surgery according to a surgical protocol and standardized follow-up.
LEVEL OF EVIDENCE
II.
Topics: Humans; Return to Sport; Prospective Studies; Talus; Sports; Bone Transplantation; Intra-Articular Fractures; Treatment Outcome; Retrospective Studies
PubMed: 37683912
DOI: 10.1016/j.otsr.2023.103675 -
Nature Communications Jan 2024
PubMed: 38191527
DOI: 10.1038/s41467-023-43045-0 -
ISA Transactions Aug 2023This manuscript proposes an improved indirect instantaneous torque control (IITC) based torque sharing function (TSF) method of switched reluctance motor (SRM) drives in...
This manuscript proposes an improved indirect instantaneous torque control (IITC) based torque sharing function (TSF) method of switched reluctance motor (SRM) drives in electric vehicles (EVs) using a hybrid system. The proposed hybrid techniques are joint performance of both Reptile Search Algorithm (RSA) and Honey Badger Algorithm (HBA), hence it is named as Enhanced RSA (ERSA) method. Here, an IITC method of SRMs for EVs is utilized. It achieves the requirements of the vehicle, like minimum torque ripple, improved speed range, high effectiveness, and maximal torque per ampere (MTPA). To precisely specify the switched reluctance motor and its magnetic features are measured by the proposed method. The modified Torque sharing function compensates the torque error along with incoming phase, which contains the minimal rate of change of flux linkage. Finally, the ERSA method is implemented to define the best control parameters. Then, the proposed ERSA system is performed on the MATLAB platform and the performance is compared to different existing systems. The MSE for case 1 and case 2 using proposed system attains 0.01093 and 0.01095. The voltage deviation for case 1 and case 2 using proposed system reaches 5 and 5. The power factor for case 1 and case 2 reaches a value of 50 and 40 using the proposed system.
PubMed: 37147220
DOI: 10.1016/j.isatra.2023.04.001 -
Science Advances Jun 2024Short-wavelength infrared (SWIR) light detection plays a key role in modern technologies. Emerging solution-processed organic semiconductors are promising for...
Short-wavelength infrared (SWIR) light detection plays a key role in modern technologies. Emerging solution-processed organic semiconductors are promising for cost-effective, flexible, and large-area SWIR organic photodiodes (OPDs). However, the spectral responsivity () and specific detectivity (*) of SWIR OPDs are restricted by insufficient exciton dissociation and high noise current. In this work, we synthesized an SWIR small molecule with a spectral coverage of 0.3 to 1.3 micrometers peaking at 1100 nanometers. The photodiode, with optimized exciton dissociation, charge injection, and SWIR transmittance, achieves a record high of 0.53 ampere per watt and * of 1.71 × 10 Jones at 1110 nanometers under zero bias. The * at 1 to 1.2 micrometers surpasses that of the uncooled commercial InGaAs photodiode. Furthermore, large-area semitransparent all-organic upconversion devices integrating the SWIR photodiode realized static and dynamic SWIR-to-visible imaging, along with excellent upconversion efficiency and spatial resolution. This work provides alternative insights for developing sensitive organic SWIR detection.
PubMed: 38838154
DOI: 10.1126/sciadv.adm9631 -
ACS Nano Dec 2023The alkaline hydrogen evolution reaction (HER) in an anion exchange membrane water electrolyzer (AEMWE) is considered to be a promising approach for large-scale...
The alkaline hydrogen evolution reaction (HER) in an anion exchange membrane water electrolyzer (AEMWE) is considered to be a promising approach for large-scale industrial hydrogen production. Nevertheless, it is severely hampered by the inability to operate tolerable HER catalysts consistently under low overpotentials at ampere-level current densities. Here, we develop a universal ligand-exchange (MOF-on-MOF) modulation strategy to synthesize ultrafine FeP and CoP nanoparticles, which are well anchored on N and P dual-doped carbon porous nanosheets (FeP-CoP/NPC). In addition, benefiting from the downshift of the d-band center and the interfacial Co-P-Fe bridging, the electron-rich P site is triggered, which induces the redistribution of electron density and the swapping of active centers, lowering the energy barrier of the HER. As a result, the FeP-CoP/NPC catalyst only requires a low overpotential of 175 mV to achieve a current density of 1000 mA cm. The solar-driven water electrolysis system presents a record-setting and stable solar-to-hydrogen conversion efficiency of 20.36%. Crucially, the catalyst could stably operate at 1000 mA cm over 1000 h in a practical AEMWE at an estimated cost of US$0.79 per kilogram of H, which achieves the target (US$2 per kg of H) set by the U.S. Department of Energy (DOE).
PubMed: 38009586
DOI: 10.1021/acsnano.3c09020 -
Journal of the American Chemical Society Oct 2023Electrochemical reduction of CO to multicarbon (C) products using renewable energy sources is an important route to storing sustainable energy and achieving carbon...
Electrochemical reduction of CO to multicarbon (C) products using renewable energy sources is an important route to storing sustainable energy and achieving carbon neutrality. It remains a challenge to achieve high C product faraday efficiency (FE) at ampere-level current densities. Herein, we propose the immobilization of an alkaline ionic liquid on copper for promoting the deep reduction of CO. By this strategy, a C FE of 81.4% can be achieved under a current density of 0.9 A·cm with a half-cell energy conversion efficiency of 47.4% at -0.76 V vs reversible hydrogen electrode (RHE). Particularly, when the current density is as high as 1.8 A·cm, the C FE reaches 71.6% at an applied potential of -1.31 V vs RHE. Mechanistic studies demonstrate that the alkaline ionic liquid plays multiple roles of improving the accumulation of CO molecules on the copper surface, promoting the activation of the adsorbed CO, reducing the energy barrier of CO dimerization, stabilizing intermediates, and facilitating the C product formation.
PubMed: 37783450
DOI: 10.1021/jacs.3c06860