Preventive replacement policies with time of operations, mission durations, minimal repairs and maintenance triggering approaches.

When a mission arrives at a random time and lasts for a duration, it becomes an interesting problem to plan replacement policies according to the health condition and repair history of the operating unit, as the reliability is required at mission time and no replacement can be done preventively during the mission duration. From this viewpoint, this paper proposes that effective replacement policies should be collaborative ones gathering data from time of operations, mission durations, minimal repairs and maintenance triggering approaches. We firstly discuss replacement policies with time of operations and random arrival times of mission durations, model the policies and find optimum replacement times and mission durations to minimize the expected replacement cost rates analytically.

Heat generation by ultrasonic bone curette comparing with high-speed drill.

Background: Ultrasonic bone curettes have been used as with high-speed drills. However, the amount of heat generated by the ultrasonic bone curette is not well known. This study quantitatively assessed the heat generated by an ultrasonic bone curette and compared it to that by a high-speed drill.

[Clinical Features of Very Elderly Patients Aged 90 Years or Above with Acute Ischemic Stroke: A Study by Using Diffusion Weighted Brain Magnetic Resonance Imaging].

We investigated the diffusion weighted magnetic resonance imaging (DWI) features of 76 very elderly patients aged 90 years or above with acute ischemic stroke. Stroke subtypes were classified into five types according to the Trial of Org 10172 in Acute Stroke Treatment (TOAST) and the Japanese Stroke Databank. The incidence rates of atherothrombotic brain infarction (ATBI), atherothrombotic brain embolism (ATBE), lacunar infarction (LI), cardiogenic brain embolism (CBE) and undetermined type of brain infarction (UTBI) were 2.

The influence of hypoglycemia on cerebral blood flow in cases of hypoglycemic coma.

The authors report two cases of hypoglycemic coma in which both diffusion-weighted imaging (DWI) and single photon emission computed tomography (SPECT) were used. A 74-year-old woman (case 1) presented with deep coma associated with hypoglycemia (blood glucose level: 20 mg/dl), and DWI on admission revealed extensive hyperintensity lesions. SPECT obtained on the second hospital day revealed diffuse hyperperfusion and a follow-up SPECT on the eighth hospital day showed relative hypoperfusion.

Internal trapping following proximal clipping for a ruptured partially thrombosed giant aneurysm of the vertebral artery--case report.

A 52-year-old woman presented with a partially thrombosed giant aneurysm of the vertebral artery (VA) manifesting as a 3-month history of left hemiparesis. She developed subarachnoid hemorrhage during hospitalization and underwent emergency surgery for surgical proximal clipping and ventricular drainage with decompressive suboccipital craniectomy. She underwent additional surgery for endovascular coil embolization of the aneurysm and the affected distal VA on the 7th postoperative day.

Reversible diffusion-weighted imaging changes in the splenium of the corpus callosum and internal capsule associated with hypoglycemia - case report - .

A 63-year-old man presented with hypoglycemia-induced hemiparesis manifesting as diffusion-weighted magnetic resonance (MR) imaging changes in the splenium of the corpus callosum and internal capsule which disappeared after glucose administration. Clinicians should be aware that hypoglycemia can cause reversible splenium abnormalities on MR imaging, although the underlying mechanism still remains unclear, as this may be helpful in the differential diagnosis of hypoglycemia-induced hemiparesis and stroke.

A case of Lhermitte-Duclos disease presenting high FDG uptake on FDG-PET/CT.

Lhermitte-Duclos Disease (LDD) is a rare cerebellar lesion that has long been controversial as to whether the entity is a hamartoma, a malformation, or a neoplasm. Recent advances in metabolic imaging and molecular biology have unveiled biological features of LDD and a close relationship between LDD and Cowden disease. Adult onset LDD is now considered identical to Cowden disease in a US guideline.

Identification of 4-S-Cysteinyltetrodotoxin from the liver of the puffer fish, Fugu pardalis, and formation of thiol adducts of tetrodotoxin from 4,9-anhydrotetrodotoxin.

The metabolic pathway of tetrodotoxin (TTX), a powerful and specific voltage-gated sodium channel blocker, has not been well-clarified either in TTX-poisoned patients or in puffer fish. 4-S-CysteinylTTX (4-CysTTX) was isolated from the liver of the puffer fish, Fugu pardalis, as the first adduct of TTX with thiol. The structure was fully characterized by electrospray ionization-MS and two-dimensional NMR spectroscopy.

Affinity labeling of a catalytic site, cysteine(247), in rat mercaptopyruvate sulfurtransferase by chloropyruvate as an analog of a substrate.

A bisubstrate enzyme, rat mercaptopyruvate sulfurtransferase (EC 2.8.1.

Renal angiomyolipoma: relationships between tumor size, aneurysm formation, and rupture.

Purpose: To evaluate the relationships between tumor size, aneurysm formation, and spontaneous rupture in renal angiomyolipomas.

Materials And Methods: Twenty-three patients with renal angiomyolipoma were examined with angiography and computed tomography (CT). The single largest lesion in each kidney was evaluated.