Zinc-Based Metal-Organic Frameworks for High-Performance Supercapacitor Electrodes:Mechanism Underlying Pore Generation

Heat treatment of metal-organic frameworks(MOFs)has provided a wide variety of functional carbons coordinated with metal compounds.In this study,two kinds of zinc-based MOF(ZMOF),C_(16)H_(10)O_(4)Zn(ZMOF1)and C_(8)H_(4)O_(4)Zn(ZMOF2),were prepared.ZMOF1 and ZMOF2 were carbonized at 1000℃,forming CZMOF1 and CZMOF2,respectively.The specific surface area(S_(BET))of CZMOF2 was~2700 m^(2)g^(−1),much higher than that of CZMOF1(~1300 m^(2)g^(−1)).A supercapacitor electrode based on CZMOF2 achieved specific capacitances of 360,278,and 221 F g^(−1)at 50,250,and 1000 mA g^(−1)in an aqueous electrolyte(H2SO_(4)),respectively,the highest values reported to date for ZMOF-derived electrodes under identical conditions.The practical applicability of the CZMOF-based supercapacitor was verified in non-aqueous electrolytes.The initial capacitance retention was 78%after 100000 charge/discharge cycles at 10 A g^(−1).Crucially,the high capacitance of CZMOF2 arises from pore generation during carbonization.Below 1000℃,pore generation is dominated by the Zn/C ratio of ZMOFs,as carbon atoms reduce the zinc oxides formed during carbonization.Above 1000℃,a high O/C ratio becomes essential for pore generation because the oxygen functional groups are pyrolyzed.These findings will provide insightful information for other metal-based MOFderived multifunctional carbons.

Pituicytoma Associated with Serum Adrenocorticotropic Hormone Elevation

Background: Pituicytoma is a rare benign tumor of the neurohypophysis or hypophyseal stalk. Endocrinological abnormalities derived from this tumor are even rarer. Although three cases of pituicytoma with elevated plasma adrenocorticotropic hormone (ACTH) have been reported previously, the etiological mechanisms remain unknown. Case Description: We present a 47-year-old woman who was referred to a hospital complaining of headache. On investigation using magnetic resonance imaging (MRI), a tumor was detected in the sellar region. Elevation of basal ACTH and serum cortisol was identified, suggesting an ACTH-producing pituitary adenoma. However, physical findings and results of other hormonal examination showed no evidence of Cushing disease. The tumor had been detected incidentally eight years earlier when MRI was performed, and showed considerable enlargement on this consultation. Endoscopic endonasal transsphenoidal surgery was performed in order to remove the tumor completely. The histopathological diagnosis was pituicytoma. The patient’s postoperative clinical course was excellent, and both ACTH and cortisol levels returned to normal following surgery. Conclusions: It appears that ACTH was being secreted from the tumor cells. We discuss the possible mechanism of ACTH elevation in cases of pituicytoma.

Hematoma within the Outer Membrane of the Arachnoid Cyst Located in the Middle Fossa: A Mechanism of Development of Chronic Subdural Hematoma Associated with Arachnoid Cysts

It is well known that chronic subdural hematoma (CSDH) occasionally arises in patients harboring an arachnoid cyst (AC) located in the middle fossa. Although the pathogenesis of CSDH associated with ACs remains unknown, several possible mechanisms have been proposed. In many reported cases, the patients with ACs in the middle fossa would be symptomatic according to development of CSDH. A 9-year-old girl presenting with a headache, nausea, and diplopia was referred to our department. Magnetic resonance imaging showed an AC in the left-side middle fossa and ipsilateral CSDH with a remarkable mass effect. Irrigation of the CSDH, partial removal of the outer membrane of the AC and CSDH, and endoscopic cystocisternostomy were performed to relieve her symptoms. Postoperative clinical course was excellent. Histopathological examination of the outer membrane of the CSDH demonstrated an arachnoid cell layer and hemorrhage from the granulation inside the membrane, and collagen fibers outside the membrane. These findings strongly suggested that the membrane and the content of the CSDH were derived from the outer membrane of the AC, and the CSF including the hemorrhage within the membrane, respectively. Laceration and hemorrhage from granulation tissue within the outer membrane of the AC are considered as one of the developmental mechanisms of the CSDH associated with AC in the middle fossa.

Acute Obstructive Hydrocephalus Caused by <i>Pseudomonas</i><i>aeruginosa</i>Ventriculitis after Transsphenoidal Surgery: Case Report

Pseudomonas aeruginosa (P. aeruginosa) frequently causes various infections, some of which are serious and require prompt medical detection and appropriate antibiotic selection. Although P. aeruginosa commonly exists within the nasal cavity, meningitis or ventriculitis following transsphenoidal surgery to relieve P. aeruginosa has been reported only occasionally. However, as the endoscopic transnasal approach is more widely utilized for the suprasellar lesions, nosocomical P. aeruginosa infection associated with cerebrospinal fluid (CSF) leakage becomes more common in patients with panhypopituitarism who undergo transsphenoidal surgery. We report a case of a 36-year-old man with an intrasellar craniopharyngioma presenting with an acute obstructive hydrocephalus caused by P. aeruginosa ventriculitis following transsphenoidal surgery. Treatment with optimal antibiotics was initiated immediately after P. aeruginosa was recognized as the pathogen, and was continued for 3 months. After removal of the infected fascia and fat graft used for the closure of CSF leakage and sellar floor reconstruction, endoscopic third ventriculostomy was successfully performed to treat the obstructive hydrocephalus induced by the occlusion of the fourth ventricle outlet, resulting in a positive outcome. Although the obstructive hydrocephalus caused by P. aeruginosa is extremely rare, prompt detection and appropriate treatment should be required once P. aeruginosa ventriculitis happens.