Successful treatment of brain metastases from ovarian cancer using gamma-knife radiosurgery

We report two cases of fully intruded tooth after facial fracture in adults. In the first case, the lateral incisor was intruded into the nasal cavity and slipped into the pyriform sinus during operation. The second case involved full intrusion of a molar into the maxillary sinus, resulting in infection. The importance of a thorough intraoral examination for patients with facial trauma is emphasized. All missing teeth should be accounted for to ensure that they have not dislodged inside the body. When full intrusion of a tooth is suspected, facial computed tomography scan may provide assistance with definite diagnosis. If an incisor is completely intruded into the nasal cavity, removal through the floor of the nostril should be considered.     

Ultrathin films of charged polysaccharides assembled alternately with linear polyions

As a means of preparation of biocompatible molecular surfaces, an alternate assembly of charged polysaccharides and oppositely-charged synthetic polymers was conducted. Cationic chitosan was assembled alternately with anionic poly(sodium styrenesulfonate) (PSS) at pH 4. Regular film growth and its dependence on ionic strength were detected by the quartz crystal microbalance (QCM) method. Averaged film thicknesses for the chitosan + PSS layer were 15, 31, 46, and 69 A, respectively, when 0, 0.25, 0.5, and 1 M of NaCl was contained in aqueous chitosan. Adsorption of chitosan did not reach saturation in 20 min at 0 M NaCl, while the adsorption became saturated within 6 min with 0.25 M NaCl. Anionic sodium chondroitin sulfate was also assembled in alternation with cationic poly(dimethyldiallylammonium chloride) (PDDA) at pH 6.5. The adsorption of chondroitin sulfate was less sensitive to ionic strength. Surface morphology of chitosan-PSS films was investigated by non-contact atomic force microscopy (AFM) observation. Maximum height difference and Ra value for a 1000 x 1000 nm area were 11 and 0.69 nm, respectively, indicating the formation of a molecularly flat surface by alternate layer-by-layer adsorption.     

Rapid and Sensitive Radioscopy for Fine Ceramics Using an Image-Subtraction Method

A new microfocus X-ray testing method has been developed to detect very small defects in ceramic products with high speed and reliability. By using image subtraction, enhanced X-ray images of defects were extracted from the background noise. Much-better sensitivity (e.g., 0.1% in Si₃N₄ that was 20 mm thick) was obtained within a few minutes. This method is considerably superior to the conventional film method. In this study, Si₃N₄ test pieces (penetrameters) that had very small artificial defects (such as slits and pores) were prepared and examined by using the new method.     

Fabrication of Zn4Sb3 Bulk Thermoelectric Materials Reinforced with SiC Whiskers

SiC whiskers have been incorporated into Zn₄Sb₃ compound as reinforcements to overcome its extremely brittle nature. The bulk samples were prepared by either hot-extrusion or hot-pressing techniques. The obtained products containing 1 vol.% to 5 vol.% SiC whiskers were confirmed to exhibit sound appearance, high density, and fine-grained microstructure. Mechanical properties such as the hardness and fracture resistance were improved by the addition of SiC whiskers, as a result of dispersion strengthening and microstructural refinement induced by a pinning effect. Furthermore, crack deflection and/or bridging/pullout mechanisms are invoked by the whiskers. Regarding the thermoelectric properties, the Seebeck coefficient and electrical resistivity values comparable to those of the pure compound are retained over the entire range of added whisker amount. However, the thermal conductivity becomes large with increasing amount of SiC whiskers because of the much higher conductivity of SiC relative to the Zn₄Sb₃ matrix. This results in a remarkable degradation of the dimensionless figure of merit in the samples with addition of SiC whiskers. Therefore, the optimum amount of SiC whiskers in the Zn₄Sb₃ matrix should be determined by balancing the mechanical properties and thermoelectric performance.     

Suppression of inhomogeneous segregation in graphene growth on epitaxial metal films

Large-scale uniform graphene growth was achieved by suppressing inhomogeneous carbon segregation using a single domain Ru film epitaxially grown on a sapphire substrate. An investigation of how the metal thickness affected growth and a comparative study on metals with different crystal structures have revealed that locally enhanced carbon segregation at stacking domain boundaries of metal is the origin of inhomogeneous graphene growth. Single domain Ru film has no stacking domain boundary, and the graphene growth on it is mainly caused not by segregation but by a surface catalytic reaction. Suppression of local segregation is essential for uniform graphene growth on epitaxial metal films.     

Obstructive Ileus caused by blood clot after emergency total gastrectomy in a patient with hemophilia A: report of a case

We report herein the extremely unusual case of a patient with hemophilia A who developed a hematoma ileus soon after undergoing an emergency total gastrectomy. Postoperatively, the patient was found to have an obstruction in the small intestine that was difficult to differentiate from intussusception. Reoperation revealed the cause of the obstruction to be a large blood clot. This case report serves to demonstrate that careful hemostasis and observation during surgery is essential in patients with hemophilia.     

Characterization of Low-Pressure Cold-Sprayed Aluminum Coatings

Aluminum alloys are widely used as materials for engineering components of automobiles and airplanes because of their light weight and high corrosion resistance. However, cracks may develop sometimes in aluminum components, which have to be repaired by welding. It is difficult to weld aluminum components due to its high specific thermal conductivity and high coefficient of thermal expansion. The low-pressure cold-spray technique can be used instead of welding for repairing cracks. However, the effects of surface conditions on particle deposition and the mechanical properties of cold-sprayed coatings have not been investigated thus far. In this study, the effect of surface conditions focusing on active newly formed surface on aluminum particle deposition is studied and the mechanical properties of low-pressure cold-sprayed aluminum coatings are investigated by four-point bending tests. It is found that for efficient particle deposition it was necessary to obtain active newly formed surface of the substrate and particle surfaces by several impingements because the existence of inactive native oxide films has an adverse effect on the deposition. Furthermore, the strength of a cold-sprayed specimen is found to be higher than that of a cold-rolled specimen under compressive loading.     

Phase series echography with prior waveform distortion for evaluating posterior waveform distortion

We describe a pulse-echo ultrasound method for measuring nonlinear waveform distortion. First, two artificially distorted ultrasound pulses, one of which is transformed into the other by using a linear transform, are prepared prior to the measurement. The linear relationship does not hold for nonlinear propagation. Second, different initial-phase versions of the two pulses are separately transmitted to a specimen one after another, then the echoes with the same turnaround time are placed in order of the initial phase. The placed echoes, called a phase series, have complete information on the posterior waveform distortion. We formulate a waveform distortion index by using these two techniques. The waveform distortion index has a monotonic increasing relationship with the nonlinear parameter B/A. As an example application, we performed tissue characterization of boiled eggs. As a result, egg whites and yolks were clearly distinguished. This method should be useful for biological tissue characterization.