Revealing Structural Evolution of Nickel Phosphide-Iron Oxide Core-Shell Nanocatalysts in Alkaline Medium for the Oxygen Evolution Reaction.

Metal phosphide-containing materials have emerged as a potential candidate of nonprecious metal-based catalysts for alkaline oxygen evolution reaction (OER). While it is known that metal phosphide undergoes structural evolution, considerable debate persists regarding the effects of dynamics on the surface activation and morphological stability of the catalysts. In this study, we synthesize NiP x -FeO x core-shell nanocatalysts with an amorphous NiP x core designed for enhanced OER activity. Using ex situ X-ray absorption spectroscopy, we elucidate the local structural changes as a function of the cyclic voltammetry cycles. Our studies suggest that the presence of corner-sharing octahedra in the FeO x shell improves structural rigidity through interlayer cross-linking, thereby inhibiting the diffusion of OH-/H2O. Thus, the FeO x shell preserves the amorphous NiP x core from rapid oxidation to Ni3(PO4)2 and Ni(OH)2. On the other hand, the incorporation of Ni from the core into the FeO x shell facilitates absorption of hydroxide ions for OER. As a result, Ni/Fe(OH) x at the surface oxidizes to the active γ-(oxy)hydroxide phase under the applied potentials, promoting OER. This intriguing synergistic behavior holds significance as such a synthetic route involving the FeO x shell can be extended to other systems, enabling manipulation of surface adsorption and diffusion of hydroxide ions. These findings also demonstrate that nanomaterials with core-shell morphologies can be tuned to leverage the strength of each metallic component for improved electrochemical activities.

The Ideal Orthopaedic Surgeon: Comparing Patient Preferences of Surgeon Attributes to Notions Held by Orthopaedic Postgraduates.

Introduction: Stereotypes have been a barrier to providing patients a diverse orthopaedic workforce. Our goal was to identify stereotypes and disparities among doctors and their patients regarding the attributes that should determine a competent orthopaedic surgeon. Materials and Methods: A cross-sectional descriptive multicenter study was conducted in India. Tailored questionnaires were administered to patients and orthopaedic postgraduates to determine the attributes they believe patients prefer in their orthopaedic surgeon. Likert data and data on preferred sex of the surgeon were analyzed as categorical data sets using frequency statistics. Participants were asked to rank surgeon attributes and analysis was based on frequency of an item among top 5 surgeon attributes. Results: 304 patients and 91 orthopaedic postgraduates participated in the study. 70.4% and 73% of patients and 27.5% and 29.6% of postgraduates preferred an orthopaedic surgeon with greater physical strength as an outpatient consultant or operating surgeon respectively. 81% of patients had no preference of the sex of their doctor. 56% of postgraduates felt patients would prefer a male operating surgeon, none felt their patient would prefer female orthopaedic surgeon. 92.3% of the female postgraduates felt patients would prefer a male orthopaedic surgeon. Patients most often ranked years of experience, surgical outcomes, time spent with patients, reputation, and physical strength in their top 5 surgeon attributes and sex, religion, and community were given least importance. Conclusion: Diversity among the orthopaedic workforce is necessary to optimize patient care. It is our collective responsibility to educate our patients and trainees and redress the misconceptions and stereotypes that plague our profession. Supplementary Information: The online version contains supplementary material available at 10.1007/s43465-023-00988-2.

Arthroscopic management of Juxta-articular chondroblastoma with bone substitutes - A case report.

Chondroblastoma, a rare benign bone tumour arising from the epiphysis, accounts for approximately 1% of all primary bone tumours and is known to be locally aggressive with potential for metastases and local recurrence. Open surgical curettage is associated with high risk of recurrence and potential for damage to the physis resulting in growth disturbances. We report a 14-year-old girl with chondroblastoma involving the distal femoral epiphysis in whom an arthroscopic approach was employed for thorough curettage of the lesion under direct vision followed by cavity management using bone graft substitute. At seven years follow-up she is asymptomatic, has normal knee function and her radiographs have shown good osteointegration of the synthetic graft with no evidence of recurrence. By combining the principles of intra-articular and endosteal arthroscopy in select patients, both tumour excision and cavity management can be done arthroscopically.

Transient cortical blindness in fat embolism syndrome---a diagnostic enigma.

Fat embolism syndrome (FES) is a serious life-threatening manifestation of the fat embolism phenomenon characterized by Bergman's triad of dyspnea, petechiae and mental confusion. While fat embolization into systemic circulation is common, FES occurs in a meagre 0.05%-3% of patients having isolated long bone fractures. Though visual symptoms are commonly attributed to fat embolism retinopathy and is a later occurrence, it may not always be the case. Cortical blindness has been seldom reported in association with FES, and less so as a presenting complaint. Furthermore, no previous literature has described the same in context of an isolated tibia fracture. We report a 20-year-old gentleman with an isolated right tibia shaft fracture who developed sudden onset diminution of vision in both eyes less than 24 h following trauma with no other complaints. Lack of any remarkable ophthalmoscopic findings or other symptoms left us with a diagnostic conundrum. He later went on to develop altered mentation, hypoxia and generalized tonic-clonic seizures with subsequent MRI revealing multiple cerebral fat emboli also involving both occipital lobes. Supportive measures were instituted and his general condition as well as vision gradually improved following which he underwent plate fixation of the fracture under spinal anaesthesia. The perioperative period was uneventful and he was discharged following staple removal. At one month of follow-up, the patient had no residual visual field defects or neurological deficits. Though FES is rare among isolated tibia fractures, this clinical catastrophe may strike in any unsuspected setting thereby warranting a high index of suspicion to ensure early diagnosis and improved patient outcomes.

Chemical Structure of Fe-Ni Nanoparticles for Efficient Oxygen Evolution Reaction Electrocatalysis.

Bimetallic iron-nickel-based nanocatalysts are perhaps the most active for the oxygen evolution reaction (OER) in alkaline electrolytes. Recent developments in literature have suggested that the ratio of iron and nickel in Fe-Ni thin films plays an essential role in the performance and stability of the catalysts. In this work, the metallic ratio of iron to nickel was tested in alloy bimetallic nanoparticles. Similar to thin films, nanoparticles with iron-nickel atomic compositions where the atomic iron percentage is ≤50% outperformed nanoparticles with iron-nickel ratios of >50%. Nanoparticles of Fe20Ni80, Fe50Ni50, and Fe80Ni20 compositions were evaluated and demonstrated to have overpotentials of 313, 327,, and 364 mV, respectively, at a current density of 10 mA/cm2. While the Fe20Ni80 composition might be considered to have the best OER performance at low current densities, Fe50Ni50 was found to have the best current density performance at higher current densities, making this composition particularly relevant for electrolysis conditions. However, when stability was evaluated through chronoamperometry and chronopotentiometry, the Fe80Ni20 composition resulted in the lowest degradation rates of 2.9 µA/h and 17.2 µV/h, respectively. These results suggest that nanoparticles with higher iron and lower nickel content, such as the Fe80Ni20 composition, should be still taken into consideration while optimizing these bimetallic OER catalysts for overall electrocatalytic performance. Characterization by electron microscopy, diffraction, and X-ray spectroscopy provides detailed chemical and structural information on as-synthesized nanoparticle materials.

Chronic anterior cruciate ligament insufficiency results in inferior quality hamstring autografts.

BACKGROUND: Availability of a good quality autograft of adequate length is the first step towards a successful knee ligament reconstruction. Being able to predict the quality and length of hamstring autograft can go a long way in making the surgeon's pre-operative planning a lot easier. The purpose of this study was to find out if any correlation existed between the duration of ACL injury with history of repeated instability episodes and the quality and length of Hamstring graft that was harvested. METHODS: Forty consecutive patients who underwent ACL reconstruction using quadrupled Hamstring tendon graft were evaluated with regard to the duration of injury, number of instability episodes and graft characteristics like difficulty in harvesting the graft, quality and length of the graft. RESULTS: We found a statistically significant difference between the usable length of harvested Hamstring tendon in patients with acute and chronic injury (p = 0.004). There was a significantly high risk of the graft being shorter and of poor quality in patients with chronic injury (odds ratio = 5.7). CONCLUSION: Chronicity of ACL injury with repeated strains can cause fibrosis at the musculotendinous junction and result in harvest of a poor quality and short hamstring autograft. A detailed history with regard to duration of injury and repeated instability episodes will help a surgeon plan better when anticipating a sub-optimal graft.

Controlling the 3-D morphology of Ni-Fe-based nanocatalysts for the oxygen evolution reaction.

Controlling the 3-D morphology of nanocatalysts is one of the underexplored but important approaches for improving the sluggish kinetics of the oxygen evolution reaction (OER) in water electrolysis. This work reports a scalable, oil-based method based on thermal decomposition of organometallic complexes to yield highly uniform Ni-Fe-based nanocatalysts with a well-defined morphology (i.e. Ni-Fe core-shell, Ni/Fe alloy, and Fe-Ni core-shell). Transmission electron microscopy reveals their morphology and composition to be NiOx-FeOx/NiOx core-mixed shell, NiOx/FeOx alloy, and FeOx-NiOx core-shell. X-ray techniques resolve the electronic structures of the bulk and are supported by electron energy loss spectroscopy analysis of individual nanoparticles. These results suggest that the crystal structure of Ni is most likely to contain α-Ni(OH)2 and that the chemical environment of Fe is variable, depending on the morphology of the nanoparticle. The Ni diffusion from the amorphous Ni-based core to the iron oxide shell makes the NiOx-NiOx/FeOx core-mixed shell structure the most active and the most stable nanocatalyst, which outperforms the comparison NiOx/FeOx alloy nanoparticles expected to be active for the OER. This study suggests that the chemical environment of the mixed NiOx/FeOx alloy composition is important to achieve high electrocatalytic activity for the OER and that the 3-D morphology plays a key role in the optimization of the electrocatalytic activity and stability of the nanocatalyst for the OER.

Arthroscopy Assisted Percutaneous Fixation of Ideberg Type Iii Glenoid Fractures.

INTRODUCTION: Intra-articular glenoid fractures are extremely rare and may be associated with other injuries. Traditionally open reduction and internal fixation has been recommended in displaced intra-articular glenoid fractures. However open reduction is difficult and it may not be possible to address the associated intra-articular soft tissue injuries. A few reports of arthroscopic assisted fixation of these fractures have been recently published. We are reporting a case of Ideberg type 3 glenoid fracture and its treatment. CASE REPORT: We are presenting our case where a 52 year old man presented with Type 3 intra-articular glenoid fracture. The fracture was fixed percutaneously under simultaneous arthroscopic and fluoroscopic guidance. CONCLUSION: Intra-articular glenoid fractures are uncommon and difficult to treat. Arthroscopy assisted percutaneous fixation technique can be a valuable adjunct for the surgeon in dealing with not only the fracture but also the associated soft-tissue injuries.