Ultrafine NiFe-Based (Oxy)Hydroxide Nanosheet Arrays with Rich Edge Planes and Superhydrophilic-Superaerophobic Characteristics for Oxygen Evolution Reaction.

NiFe-based (oxy)hydroxides are the benchmark catalysts for the oxygen evolution reaction (OER) in alkaline medium, however, it is still challenging to control their structures and compositions. Herein, molybdates (NiFe(MoO4 )x ) are applied as unique precursors to synthesize ultrafine Mo modified NiFeOx Hy (oxy)hydroxide nanosheet arrays. The electrochemical activation process enables the molybdate ions (MoO4 2- ) in the precursors gradually dissolve, and at the same time, hydroxide ions (OH- ) in the electrolyte diffuse into the precursor and react with Ni2+ and Fe3+ ions in confined space to produce ultrafine NiFeOx Hy (oxy)hydroxides nanosheets (<10 nm), which are densely arranged into microporous arrays and maintain the rod-like morphology of the precursor. Such dense ultrafine nanosheet arrays produce rich edge planes on the surface of NiFeOx Hy (oxy)hydroxides to expose more active sites. More importantly, the capillary phenomenon of microporous structures and hydrophilic hydroxyl groups induce the superhydrophilicity and the rough surface produces the superaerophobic characteristic for bubbles. With these advantages, the optimized catalyst exhibits excellent performance for OER, with a small overpotential of 182 mV at 10 mA cm-2 and long-term stability (200 h) at 200 mA cm-2 . Theoretical calculations show that the modification of Mo enhances the electron delocalization and optimizes the adsorption of intermediates.

Corrosion Engineering towards NiFe-Layered Double Hydroxide Macroporous Arrays with Enhanced Activity and Stability for Oxygen Evolution Reaction.

NiFe-layered double hydroxide (NiFe-LDH) is the benchmark catalyst for the oxygen evolution reaction (OER) in alkaline medium, however, it is still challenging to improve its activity and stability. Herein, NiFe-LDH macroporous array electrodes are demonstrated to significantly enhance the activity and stability for oxygen evolution reaction. The electrodes are fabricated by the chemical and electrochemical corrosion process of Ni foam induced by ferric nitrate, hydrochloric acid and oxygen. By optimizing the amount of iron salt and acid and selecting the appropriate reaction temperature and time, the NiFe-LDH electrodes only need the overpotential of 180 mV and 248 mV to reach the current density of 10 mA cm-2 and 500 mA cm-2 , respectively, and remain highly stable for 1000 h at 500 mA cm-2 . The unique macroporous array not only significantly increases the active area of NiFe-LDH catalyst, but also creates a stable nanostructure that avoids severe reconstruction.

Coexistence of meningioma and other intracranial benign tumors in non-neurofibromatosis type 2 patients: A case report and review of literature.

BACKGROUND: The coexistence of meningioma and other intracranial primary benign tumors is rare, especially in non-neurofibromatosis type 2, and there is limited guidance for the management of such patients. Here, we report a series of 5 patients with concomitant meningioma and other intracranial benign tumors, including subependymoma and pituitary adenoma. CASE SUMMARY: Five non-neurofibromatosis type 2 patients with simultaneous occurrence of meningioma and other intracranial benign tumors were retrospectively reviewed. The patients had no history of previous irradiation. The clinical features, pre- and postoperative imaging, surgical procedure and pathological findings were extracted from electronic medical records. There were 4 female patients (80%) and 1 male patient (20%). The mean age was 42.8 years (range: 29-52 years). The coexisting tumors included subependymoma in 1 case (20%) and pituitary adenoma in 4 cases (80%). The most common clinical symptom was headache (3/5, 60%). Four patients (80%) underwent craniotomy. One patient (20%) underwent transsphenoidal surgery followed by transcranial operation. All tumor diagnoses were confirmed by histopathological examination. The mean follow-up was 38.8 mo (range: 23-96 mo), and all 5 patients were in a stable condition at the last follow-up. CONCLUSION: The simultaneous occurrence of meningioma and other intracranial benign tumors is a rare clinical event. Histological examination is necessary for the accurate diagnosis. Neurosurgeons should select the appropriate surgical strategy according to the clinical features of each patient, which may provide a more favorable prognosis for individual patients.