Detection of nonmagnetic metal thin film using magnetic force microscopy

Magnetic force microscopy (MFM) allows detection of stray magnetic fields around magnetic materials and the two-dimensional visualization of these fields. This paper presents a theoretical analysis of the oscillations of an MFM tip above a thin film of nonmagnetic metal. The results show good agreement with experimental data obtained by varying the tip height. The phenomenon analyzed here can be applied as a "metal detector" at the nanometer scale and for contactless measurement of sheet resistivity. The detection sensitivity is obtained as a function of oscillation frequency, thus allowing determination of the best frequency for phase-shift measurement. The shift in resonance frequency due to the presence of a nonmagnetic metal is also discussed.Comment: 4 pages, 5 figure

Connection of four-dimensional Langevin model and Hauser-Feshbach theory to describe statistical decay of fission fragments

We developed a method superposing two different fission modes calculated in a four-dimensional Langevin model to obtain more accurate fission fragment yield and total kinetic energy (TKE). The two fission modes correspond to the standard I and standard II modes reported by Brosa et al., and parameters in the Langevin model and the superposing ratio were determined to reproduce the fission fragment yield of $^{240}$Pu of spontaneous fission. We also investigated the fission fragment yields and the TKEs of other Pu isotopes by using the same Langevin parameters and different superposing ratios, such as spontaneous fission of $^{238,242}$Pu and neutron-induced fission of $^{239}$Pu. The prompt fission observables, such as the neutron multiplicity, the prompt fission neutron spectrum, and the independent fission product yield were calculated in the Hauser-Feshbach statistical decay model implemented in a nuclear reaction code TALYS with $^{239}$Pu(n,f) in the incident energies ranging from thermal energy up to 5 MeV. The calculated fission observables qualitatively reproduce several known trends while calculated results have quantitative discrepancies between reported data. Although more improvements are needed for the most important nuclides, it turned out that our approach has the capability to provide prompt fission observables for difficult-to-measure nuclides.Comment: 19 pages, 10 figures, Under review in Journal of Nuclear Science and Technolog

Esophageal tracheobronchoplasty for diseases of the central airway

AbstractThree infants with congenital tracheal stenosis and three adults with various diseases of the central airway underwent esophageal tracheobronchoplasty to repair long-segment stenoses and defects. The primary operative goal was enlargement of the stenosis ( n = 4), repair of the defect ( n = 1), or both ( n = 1). Cardiopulmonary support was required in two cases. All three infants were operated on for generalized congenital tracheal stenoses. There was one postoperative death on the fifth day. Another infant died of pneumonia 3 months after operation. Tracheal patency was excellent in two infants. One infant is well without symptoms 6 years after the operation, although balloon dilation was required three times during the first postoperative year. In the three adult patients, the primary diseases were congenital tracheal stenosis, iatrogenic injury associated with relapsing polychondritis, and malignant mediastinal tumor involving the trachea. All lesions involved both the trachea and main stem bronchi. Postoperative airway patency was excellent in all three adults, although expandable metallic stents had to be inserted in one patient. Postoperative pulmonary function was improved, particularly forced expiratory volume in 1 second and peak expiratory flow rate. Although the postoperative mortality rate was still high, especially among the infants, and prolonged postoperative ventilatory support was required for five of the six patients, long-term patency and postoperative pulmonary functional improvement are encouraging. (J Thorac Cardiovasc Surg 1996;112:124-9

Constant Current vs. Constant Voltage Systems for Temporal Spinal Cord Stimulation for Intractable Pain

Although spinal cord stimulation (SCS) is a useful treatment for chronic intractable pain, the optimal method of stimulation has not yet been established. In this prospective, crossover study, we compared the efficacy of using a constant current (CC) system with that of a constant voltage (CV) system for temporal SCS. Twenty patients were enrolled and divided into two groups. For 10 patients, a CV system was applied on Days 1-5, followed by the use of a CC system on Days 6-10. For the other 10 patients, a CC system was applied for the first five days, followed by a CV system for the subsequent five days. We evaluated the alteration of pain intensity using a visual analogue scale (VAS), the area of stimulation, the stability of effect, and patient satisfaction regarding treatment. The pain scores decreased significantly after the start of the SCS. There was no significant difference in the change in VAS between the two systems. The stimulation method used for temporal SCS did not affect the reduction of pain intensity. Patients felt a wider stimulation area by the CC system compared to the CV system

Classification of Primary Hepatolithiasis According to Morphology of the Liver, Especially Atrophy of Hepatic Parenchyma

One hundred twenty one patients with primary hepatolithiasis (PHL) was encountered for the last 7 years. In order to elucidate how to follow and treat PHL, PHL was classified into five types (I-V) on the basis of morphological findings obtained by CT. It depends mainly on the presence of atrophy of hepatic parenchyma (AHP) and dilatation of intrahepatic bile ducts (DIBD). Methods of treatment were selected for each patient according to the classification. Type I patients comprised of 43.8% in observation group. These patient were asymptomatic and just followed since neither APH nor DIBD were observed. The remaining patients in the observation group, operation was refused or contraindicated. Most of them were asymptomatic. Surgical treatments were done on 47 patients (hepatic resection in 32 patients, surgical lithotomy in 10 and others in 5). In Type III, IV and V, hepatic resection was often performed to remove all of stones and bile stasis since improvement in hepatic function could not be expected in view of AHP. All patients were followed-up 79 months or less. In the surgically terated patients, recurrence was not observed. In observation group, no new symptome developed during the follow-up period. It was suggested, therefore, that the present classification of PHL was helpful in determining therapeutic strategy for PHL

Autonomous right-screw rotation of growth cone filopodia drives neurite turning

The clockwise turning of neurites is caused by the rotations of filopodia as they extend and sweep across the substratum