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The de Haas-van Alphen (dHvA) effect in LaB 6 single crystal has been studied in detail using the field modulation technique. Observed dHvA frequencies in the (010) and (1\bar10) planes range from the order of 10 6 to 10 8 gauss. The angular dependence of the dHvA frequencies and the disappearance of the oscillation in some angular regions indicate that the Fermi surface of LaB 6 consists of a multiply connected surface, large pieces of which are centered at the point X (or M) in the simple cubic Brillouin zone. The electron density calculated from the Fermi surface is 1.39×10 22 cm -3 which corresponds to just one electron per unit cell.

Single crystals of tungsten carbide were grown by the floating-zone technique by adding boron in the molten zone. It is confirmed that WC decomposes into cubic WC1−x and carbon at an elevated temperature and cannot coexist with the liquid which consists of only tungsten and carbon. It was theoretically expected that addition of boron would stabilize the WC structure so that the WC phase could coexist with the liquid. This was proved by the float zoning through the WC rod which contained boron. The WC phase was deposited from the molten zone which consists of tungsten, carbon and boron. The growth of single crystals of WC was carried out under pressurized helium gas atmosphere of 1 M Pa. The molten zone, whose temperature was about 2900°C, was inductively heated and driven downwards. The compositions of the molten zone and the feed rod were [W]/[C]/[B] = 1/0.65/0.06 and 1/1.08/0.007 (atomic ratio), respectively. Single crystals with dimensions 9 mm diameter and 5 mm long can be cut out from the zone-passed rod. The boron content in the crystal could be lowered to the order of 100 p.p.m.

ZrC x single crystals have been prepared over the entire composition region by a floating zone technique. It was found that the crystal rods prepared by a usual floating zone method have composition changes along the growth direction, as predicted by the phase diagram, and that, in addition, the composition of the molten zone changes due to evaporation. ZrC x crystals with constant desired compositions have been prepared by controlling the compositions of the initial molten zone and the feed rod (a modified zone leveling method). The crystals were characterized by carbon analysis, impurity analyses, back-Laue and etching methods.

The temperature distribution in a growing crystal rod was calculated using a simplified model, in which the heating power was supplied by RF heating. The temperature distribution is determined by the Biot number (Bi) and the heating parameter δ/a (ratio of the skin depth δ to the rod radius a). In the case of refractory materials, crystal rods with 0.5 cm radius and RF heating (200kHz), one obtains Bi = 0.02–0.2 and δ/a = 0.2–0.6. Therefore, the temperature distributions were calculated for the cases of Bi = 0.01, 0.1, 1.0 and δ/a = 0, 0.2, 0.7. The calculated results were compared with the experimental results of Mo and TiC, which have the lowest and highest Biot numbers, respectively. The results agree well with each other.

TiCx single crystals have been prepared in the nonstoichiometric composition range (C/Ti < 0.91) by a floating zone technique. The crystal compositions were controlled by a modified zone leveling method because the crystal composition deviates much from the feed rod composition due to evaporation. The crystal compositions were determined by carbon analysis. The composition homogeneity was checked. The oxygen and nitrogen impurities were analyzed. The relationship between the composition and the lattice constant was determined. In addition, the evaporation rate and the evaporation composition were measured as a function of the zone composition by making use of the fact that the zone composition was kept constant during a zone pass. On the basis of these experimental results, the composition of the grown crystal was calculated as a function of the feed rod composition and the growth rate. The composition change due to evaporation was discussed.

Angular variations of de Haas-van Alphen frequencies of the order of 10 4 gauss in LaB 6 have been studied in the low magnetic fields by the torque method. These frequencies are interpreted as interconnecting necks between nearly spherical ellipsoids which are centered at the points X in the simple cubic Brillouin zone. The magnetic breakdown field is estimated to be about 150 kOe from the Fermi surface parameter. These results are consistent with already reported do Haas-van Alphen data.

Single crystals of EuB6 have been prepared using a floating zone technique. The crystal was grown in an ambient Ar gas pressure of 20 atm. The obtained crystal has been characterized using X-ray diffraction, mass density measurement and chemical analyses of stoichiometry and impurity content. Measured electrical and magnetic properties of the crystal differ markedly from previous results performed on polycrystalline specimens by other authors.

During crystal growth of high melting point materials such as Mo, W and TiC, using the floating zone method, it is important to decrease the heating power of the rf induction furnace by decreasing the heat flow to the feed rod. Alternate slits were made in the feed rods of Mo and W, and the dependence of the heating power on the slit interval was examined. In TiC, the dependence of the heating power on the feed rod density was examined. In both cases, the heating power could be decreased by 20%.

Single crystals of TiC doped with tungsten (W) have been prepared using a floating zone method. The relationship between the density of the subgrain boundary and the growth conditions was examined by studying the (100) etching patterns. Consequently the boundary density in the crystal decreased to one fourth, 200 cm -1 ,compared with the W-free crystal. It was found from the measurement of electron probe X-ray microanalyzer (EPMA) that the inhomogeneous distribution of W suppressed the formation of the subgrain boundaries.

The thermal diffusivity of three pyrolytic graphites was measured using the modulating electron beam method over the temperature range from 1300°C to 1900°C. One of the specimens was as-deposited at 2500°C, and the others were the same heat-treated at 3000°C after deposition. The mean free path of phonons was estimated by analysis of the experimental data. The mean free path seems to be independent of temperature in the direction perpendicular to the deposition plane; being 4·8 A for the as-deposited specimen, 6·4 and 7·4 A for the two heat-treated ones, respectively. The temperature dependence of the mean free path parallel to the deposition plane cannot be expressed in analytical form. However, a monotonie decrease from 91 A at 1330°C to 56 A at 1980°C is indicated by a tentative approximate calculation.

The thermal diffusivities of carbon materials were determined over the temperature range from 1, 300° to 1, 900°C, by using the modulating eleciron beam method. The thermal conductivities were calculated from the diffusivity values obtained by this method and the values of heat capacity available in published literature. The resulting data was found to possess anisotropic properties, which were attributable to the method of preparation of the materials. The largest anisotropy was observed in pyrolytic graphite, whose ratio of anisotropy was about 100 in this temperature range. The anisotropy ratio of mold pressed natural graphite was about 3, which larger than that of artificial graphite. The thermal conductivities of glassy carbon appeared to be independent of temperature, and were 2.7×10-2, 2.4×10-2 and 2.2×10-2cal/sec·cm·°C for the qualities called GC-30S, GC-30 and GC-20, respectively.

Background It is unclear whether S-1 plus cisplatin is effective for patients with recurrent gastric cancer after adjuvant S-1 chemotherapy. Methods We retrospectively evaluated the efficacy of S-1 plus cisplatin in patients whose gastric cancer recurred after adjuvant S-1 chemotherapy. Results In the 52 patients evaluated, the median duration of adjuvant S-1 chemotherapy was 8.1 months, and the median recurrence-free interval (RFI) since the last administration of adjuvant S-1 was 6.4 months. Among the 36 patients with measurable lesions, 7 achieved a complete or partial response, and 13 were evaluated as having stable disease, for an overall response rate of 19.4% and a disease control rate of 55.6%. For all patients, the median progression-free survival (PFS) was 4.8 months, and the median overall survival (OS) was 12.2 months. Compared with patients with an RFI of

Background This study was designed to evaluate the efficacy and safety of XELOX plus bevacizumab in a Japanese metastatic colorectal cancer population that included elderly patients. Methods This was a multicenter, single-arm, open-label prospective study. The major inclusion criteria were previously untreated metastatic colorectal cancer, presence of measurable lesions, age ≥20 years; Eastern Cooperative Oncology Group performance status of 0–2, and adequate organ function. Patients received bevacizumab (7.5 mg/kg on day 1) and XELOX (130 mg/m2 oxaliplatin on day 1 plus 1,000 mg/m2 capecitabine b.i.d. on days 1–14) every 3 weeks. The primary endpoint was confirmed objective response rate. Results The study included 47 patients (male/female 30/17; median age 69 years; age range 38–81 years with 10 patients ≥75 years; PS 0/1/2, 40/5/2) enrolled between May 2010 and March 2011. Responses were assessed in 46 eligible patients. The objective response rate was 52.2 % (95 % confidence interval [CI] 37.0–67.1). The median progression-free survival and overall survival were 10.0 months (95 % CI 7.8–12.3) and 34.6 months (95 % CI 19.9–not estimable), respectively. Frequently encountered grade 3 and 4 adverse events in this study were aspartate aminotransferase elevation (23.4 %), alanine aminotransferase elevation (21.3 %), anorexia (12.8 %), neutropenia (10.6 %), fatigue (8.5 %) and anemia (6.4 %). Grade 3 or 4 peripheral neuropathy was not observed. Conclusion First-line treatment with XELOX plus bevacizumab showed a promising response rate and an acceptable tolerability profile in the clinical practice of Japanese metastatic colorectal cancer patients that included elderly patients. Registry UMIN-CTR, ID number: UMIN000003915, URL:https://upload.umin.ac.jp/cgi-open-bin/ctr/ctr.cgi?function=brows&action=brows&type=summary&recptno=R000004706&language=E

An apparatus for automatic preparation of TiC single crystals was developed by using the RF heating floating zone method. Crystals 1 cm diameter and 6 cm long were thus prepared.

A floating zone method using indirect heating for the preparation of single crystals of YB 66 is described. Single crystals up to 11 mm in diameter and 50 mm in length have been obtained. Their growth direction was controlled to the [100] or [110] direction by a seeding process. The crystals have been characterized by X-ray diffraction, electrical resistivity measurements and chemical etching.

A new floating zone technique for keeping a molten zone composition constant has been developed. Using this new technique, the evaporation composition and the evaporation rate could be easily obtained as a function of molten TiCx composition in the range of 2800 to 3100° C. In addition, the dependence of the evaporation rate on the ambient helium gas pressure was examined in the range of 3.6 to 32 atm.

From 1966 to 1985, 2130 patients with gastric cancer were admitted to our surgical department. Among these cancers, gastric cancer following partial gastrectomy for benign gastroduodenal lesion were present in 22 (1%) patients. The original pathology was gastric ulcers in 64% (14 patients), duodenal ulcers in 23% (5 patients), combined gastric and duodenal ulcers in 9% (2 patients), and leiomyoma of the gastric cardia in 4% (1 patient). Fourteen patients were reconstructed by Billroth II, 7 by Billroth I, and one had an esophagogastrostomy after a proximal gastrectomy. The cancer in 19 (86%) patients was resected and 3 (14%) could not be resected. Only 2 (9%) were early cancer, 20 (89%) were advanced cancer including 11 (50%) with Borrmann type 3. A higher proportion of positive lymphnode metastasis was observed for residual gastric cancer (84%) than for primary gastric cancer (49%). The overall 5-year survival rate was 32%, with a 5-year survival rate of 45% for those who underwent curative resection.

Three patients with hepatic cirrhosis who had undergone gastric operations following endoscopic sclerotherapy were retrospectively reviewed. One patient had undergone total gastrectomy for gastric cancer and two had Hassab and Tanner operations for gastric and esophageal varices. All patients were recovering with no complications related to the operations and were free of disease for 2 years, postoperatively. When esophageal varices are found in combination with an upper gastric cancer that requires total gastrectomy, endoscopic sclerotherapy for esophageal varices is contraindicated because severe esophageal injuries may be induced by the sclerosing agent. The Hassab and Tanner method is useful for esophageal and gastric varices after sclerotherapy. A repeat endoscopic sclerotherapy should be performed after this operation.

From 1975 to 1984, 894 patients with gastric cancer were operated on in the Department of Surgery at Kurume University School of Medicine. Of these, 86 (10%) had upper gastric cancer invading the esophagus. The 86 resected tumors were divided into two groups according to the surgical approach, thoraco-abdominal or abdominal. Twenty-three (27%) were resected through the abdominal approach and 63 (73%) were resected by the thoraco-abdominal approach. The overall positive mediastinal lymphnode metastasis rates for the 55 patients who underwent mediastinal lymphnode dissection by the thoraco-abdominal approach were 22% for differentiated type and 37% for undifferentiated type. The positive mediastinal lymphnode metastasis and the correlation to the extent of esophageal cancer invasion were observed at a minimal 7 mm distance from the esophago-gastric (E-G) junction for the undifferentiated type, and 2.2 cm for the differentiated type. Sixteen patients with cancer invading the esophagus were radically resected by the abdominal approach with an overall survival rate of 39%, while 48 were resected by the thoraco-abdominal approach with a 5 year survival rate of 40%. The 86 resected tumors were further subdivided into two groups according to the year of surgery. From 1975 to 1979, the abdominal approach was employed in 36% and the thoraco-abdominal approach in 64% of the surgeries, with an overall curative resection rate of 47%. However, from 1980 to 1984, the abdominal approach was employed in only 17% and the thoraco-abdominal approach in 83% of the surgeries and the curative resection rate increased to 59%.(ABSTRACT TRUNCATED AT 250 WORDS)

To study some of the biochemical and physical states of membranes associated with hyperproliferation, the effect of topical hexadecane on membrane fluidity in guinea pig epidermis was investigated by electron spin resonance using a 5-doxylstearic acid spin labeling agent. Guinea pig epidermal cells were separated into three regions of keratinocytes by Percoll density gradient centrifugation. Membrane fluidity and Na + , K + -ATPase activity were higher in hyperproliferating epidermal cells than in control. The free cholesterol content and the molar ratio of free cholesterol to phospholipid were found to decrease significantly. Also, elevated levels of palmitic acid, stearic acid and ω-3 unsaturated fatty acid derived from phospholipid were observed. Normal differentiation of epidermis was found to be accompanied by a decrease in membrane fluidity, whereas a relatively high membrane fluidity was maintained in the hexadecane-induced hyperproliferation.

The clean surface of TiC(001) prepared by flash-heating at ~ 1500°C shows a 1 × 1 ordered atomic structure. No gradient of chemical composition exists over the shallow surface region of ~15 A. The work function of the clean surface is 3.8 ± 0.1 eV at room temperature. The features of oxygen chemisorption are similar to those of noble metals such as Ag and Cu; the average sticking probability is about two order of magnitude less than those of Ti and W metals, and the work-function change is also small. The oxygen atoms are preferentially chemisorbed on the carbon sites at the topmost layer, which is responsible for the small change in work function.

Raman spectra of the phonons were measured in a metallic LaB 6 single crystal using the 4880- and 5145-A excitations of an argon ion laser. From the group theoretical analysis, three Raman active modes of symmetries A 1 g , E g and F 2 g are expected and observed peaks have been assigned to these modes on the basis of the polarization measurements. The results are compared with those of some other metal hexaborides.

The thermal conductivity of AIN was measured by the modulated electron beam technique at high temperatures. The specimens for measurement had different oxygen impurity content of 0.94 wt% to 4.49 wt%. The result shows no apparent correlation between the oxygen content and the thermal conductivity. The values of measured thermal conductivity of AIN are about two times higher than that of previous measurements and are comparable with that of Taylor and Lenie. 2 figs., 1 table, 6 refs.

The thermal diffusivity of aluminum nitride was measured within the range from 1200° to 1630°C by electron beam method. The density of samples was from 83% to 95% of theoretical density. Thermal conductivity values were calculated from the thermal diffusivity data. The values were from 0.0204 (1250°C) to 0.0165 (1630°C) cal/cm·sec·deg. Thermal conductivity data of aluminum nitride in this temperature range can not be found in the literature, however, Taylor and Lenie have reported the data only within the temperature range from 200° to 800°C. Extrapolation of their values seems to be in fair contrast to the present author's.

High T c superconductor YBa2Cu3O y , having various oxygen contents have been examined by a.c. susceptibility, d.c. conductivity and Raman spectrum measurements. The T c is greatly affected by the oxygen content, being lowered by decreasing oxygen content. Particularly, the T c drops markedly when the compound takes a tetragonal form. To confirm the y vs temperature relation, the compound was reexamined by thermogravimetry. The new results cast doubt on our previous y value (6.5>y>5.8).

Thermogravimetric experiment was performed to determine oxygen content in the high T c superconductor YBa2Cu3O y . The y varies from 5.8 to 6.5 depending on temperature and oxygen fugacity, indicating that the average valence of copper ions is between 2 and 1. The oxygen content is strongly affected by quenching process of a sample. High-temperature X-ray diffraction study showed orthorhombic-to-tetragonal transition (second or possibly higher order) at around 900 K. Combining this fact with the thermogravimetric data, we concluded that the compound having y less than ∼6.0 has a tetragonal symmetry.

Superconducting properties of Ba2-x Y1+x Cu3O7-y (x=0.09) have been investigated by using samples prepared in different oxygen partial pressure. It is found that critical current density increases rapidly with the higher oxidation leading to the large Meissner signal while superconducting transition temperatures remain at about 90 K.

We report X-ray and chemical properties, phase transition, magnetic susceptibility and superconducting transition temperature of Ba2(1-x)Sr2x YCu3O7-y . Structural instability was detected for sample with x≥0.6. Phase transition occurs at oxygen number of 6.6. Anomalies in magnetization curves at 4.2 K were detected. The T c decreases linearly from 92 to 80 K with an increase of x. Strontium and oxygen contents are parameters correlated with the depression of T c.

The surface states (∼2 eV below E F ), which are originated mainly from the dangling bonds of boron atoms on the LaB 6 (100) clean surface, disappear at an oxygen exposure of ∼ 1.4 L. At the same exposure, an oxygen sticking-coefficient has a maximum value, ∼1.0. A change in the work function due to oxygen adsorption increases linearly with increasing surface oxygen and varies its slope at the above-mentioned exposure. At a low oxygen-exposure of ∼0.38 L, the first peak appears at ∼6.6 eV below e f in UPS spectra. The second overlapping oxygen peak at ∼6.0 eV below E F in UPS spectra, which grows around l L and overcomes the first peak, shifts to the low binding-energy side above ∼1.4 L. The (1 × 1) LEED pattern does not disappear until an oxygen exposure of several hundreds langmuir. It is suggested that the results support the presence of more than two adsorption states. The results are principally interpreted on the basis of two kinds of chemisorption sites; one is a boron site, and another a lanthanum site.

Single crystals for X-ray structural analyses were prepared and characterized by thermogravimetric (TG) and X-ray powder diffraction methods. Superconductive compounds obtained are tetragonal or orthorhombic in crystal system at room temperature. The value x in the chemical formula Ba2YCu3O6.5+x is in the range of 0.25 to -0.6 on the basis of TG curves of the stoichiometric compound measured in nitrogen or oxygen atmosphere. Oxygen contents of the compounds are mainly controlled by oxygen fugacity, permeability of oxygen into specimens, cooling rate and grain sizes of the crystals.