Publications by authors named "Kojima O"

Magnetic fields can increase the intensity of terahertz (THz) waves due to changing the dipole moment direction using the Lorentz force. This study reports the increase in the THz-wave intensity generated by differential frequency mixing using commercial permanent magnets under exciton-excitation. While a weak magnetic field applied to a multiple quantum well increases the THz-wave intensity due to excitons, a strong field causes its decrease.

View Article and Find Full Text PDF

Intense terahertz-wave emission in the higher frequency region can result in various applications such as terahertz spectroscopy and ultrafast data communication. In this study, an increase in terahertz waves by the overlap of exciton states in different quantum wells and spectroscopic demonstration are reported. The excitation energy dependence of signal intensity shows the effect of the overlap.

View Article and Find Full Text PDF

A broadly tunable THz source is realized via difference frequency generation, in which an enhancement to χ that is obtained via resonant excitation of III-V semiconductor quantum well excitons is utilized. The symmetry of the quantum wells (QWs) is broken by utilizing the built-in electric-field across a p-i-n junction to produce effective χ processes, which are derived from the high χ. This χ media exhibits an onset of nonlinear processes at ~4 W cm, thereby enabling area (and, hence, power) scaling of the THz emitter.

View Article and Find Full Text PDF

Study Design: Retrospective study.

Purpose: To investigate the relationship between preoperative total spinal sagittal alignment and the early onset of adjacent segment degeneration (ASD) after single-level posterior lumbar interbody fusion (PLIF) in patients with normal sagittal spinal alignment.

Overview Of Literature: Postoperative early-onset ASD is one of the complications after L4-L5 PLIF, a common surgical procedure for lumbar degenerative disease in patents without severe sagittal imbalance.

View Article and Find Full Text PDF

In this study, we report the effect of the excitation of non-exciton components caused by broadband pulses on quantum beat oscillation. Using a spectrally controlled pump pulse, a long-lived oscillation is clearly observed, and the pump-power dependence shows the suppression of the dephasing rate of the oscillation. Our results from incoherent carrier generation using a continuous wave laser demonstrate that the non-exciton components behaving as free carriers increase the oscillation dephasing rate.

View Article and Find Full Text PDF

We report a rare case of peritoneal metastasis from colon cancer being found in the bilateral sites of inguinal hernia repair. The patient was an 85-year-old man who underwent colonoscopy for a positive fecal occult blood test, with a subsequent diagnosis of ascending colon cancer. He had undergone mesh plug repair for bilateral inguinal hernias at another hospital 6 years previously.

View Article and Find Full Text PDF

We report a death case of a man in his sixties with pneumocystis pneumonia during chemotherapy for gastric cancer. He was diagnosed with cStage IIIB (T4a, N2, H0, P0, M0). Because of bulky N2, systemic chemotherapy of S-1 and CDDP was performed from April 2009.

View Article and Find Full Text PDF

We experienced inadequate gas supply to the patients from the breathing circuit of anesthesia delivery system with APL valve at full open position. It was hardly noticed after the check-up before starting work with anesthesia delivery system. This problem was caused by the mistake in installing the one-way valve when the repair of anesthesia delivery system was done.

View Article and Find Full Text PDF

Objective: To assess the feasibility of intra-operative autotransfusion (IAT) as a method of decreasing or avoiding homologous blood transfusion during radical cystectomy.

Patients And Methods: IAT was performed in 10 patients with bladder cancer who underwent radical cystectomy. The patients were divided into two groups: group 1 consisted of six patients without and group 2 of four patients with pre-deposited blood.

View Article and Find Full Text PDF

Purpose: Intraoperative autotransfusion in urological operations has the risks of reinfusing urine constituents, bacteria and cancer cells. We assessed the efficacy of intraoperative autotransfusion and leukocyte removal filters to separate red blood cells from these constituents.

Materials And Methods: Concentrated red blood cells were mixed with urine, bacteria (Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumoniae) and tumor cells (KK47 and ACHN), and processed with the intraoperative autotransfusion device.

View Article and Find Full Text PDF

The efficacy of combined use of hyperthermia and intratumoral cisplatin (CDDP) injection was investigated in rabbit rectal carcinoma models produced by VX2 carcinoma injection. Local hyperthermia was administered with a 13.56 MHz radiofrequency generator at 42-43 degrees C for 30 min.

View Article and Find Full Text PDF

We have developed a new dosage form, PEP-CH, consisting of peplomycin adsorbed onto small activated carbon particles. Ten patients with inoperable advanced esophageal cancer were treated with endoscopic local injection of PEP-CH combined with radiation using 60Co. Two of 5 patients who completed the treatment have survived over one year (19 and 23 months) now.

View Article and Find Full Text PDF

Background: A new drug-delivery format comprising activated carbon particles adsorbing peplomycin (PEP-CH) was developed for the treatment of superficial esophageal cancer.

Methods: The drug distribution was measured in rats that received subcutaneous injections of PEP-CH or peplomycin aqueous solution. In 6 patients with superficial esophageal cancer, peplomycin as PEP-CH, 5-10 mg once a week for 4-10 weeks (total, 40-100 mg/patient) was injected endoscopically into primary lesions.

View Article and Find Full Text PDF

Background: A new drug-delivery formulation of cisplatin, whereby cisplatin was incorporated in lactic acid oligomer microspheres (CDDP-MS), has been developed in dosage form for peritoneal carcinomatosis and has been designed to release 70% of the incorporated cisplatin slowly during a period of 3 weeks. In this study, its pharmacologic effects were examined in rodents.

Methods: CDDP-MS was tested to determine (1) tissue distribution of cisplatin after intraperitoneal administration of cisplatin at 3.

View Article and Find Full Text PDF

A clinical trial of a novel modality consisting of preoperative irradiation and intraluminal hyperthermia therapy, with or without 5-fluorouracil (5-FU) suppositories, was conducted on 30 patients with rectal cancer. To create hyperthermia in rectal cancer, an intraluminal electrode connected to a radiofrequency system was devised. Patients were treated preoperatively with a total irradiation dose of 30 Gy, being 3 Gy every 2 days, and 5 applications of hyperthermia given twice a week, with or without 5-FU suppositories, given as 100 mg a day to a total of 2,000 mg.

View Article and Find Full Text PDF

Activated carbon particle adsorbed-peplomycin (PEP-CH) was administered to three patients who had advanced esophageal cancer and its clinical usefulness was evaluated. The PEP-CH was injected endoscopically into the tumor or the adjacent normal esophageal tissue. Case 1 and case 3 were treated by topical injection of PEP-CH with or without surgery and case 2 was subjected to the PEP-CH treatment with radiation.

View Article and Find Full Text PDF

We report our study on the correlation between the types of anastomosis and the incidence of anastomotic stricture formation in the upper gastro-intestinal tract. Our experience with balloon dilatation is also reported. We examined the incidence of stricture formation among patients who had an anastomosis between the esophagus and stomach following subtotal esophagectomy for esophageal cancer, and esophagojejunostomy following proximal or total gastrectomy for gastric cancer in the past 17 years.

View Article and Find Full Text PDF

Attempts to prevent peritoneal carcinomatosis after surgery for gastric cancer by intraperitoneal administration of anticancer drugs have not been successful, largely because the drugs are not retained in the peritoneal cavity. We have assessed the prophylactic efficacy of a delayed-release preparation--mitomycin adsorbed onto activated charcoal (M-CH). 50 patients with gastric cancer and serosal infiltration were randomly assigned intraperitoneal treatment with M-CH (50 mg mitomycin intraoperatively) or no anticancer prophylaxis (control).

View Article and Find Full Text PDF

Estrogen receptors (ER) and progesterone receptors (PgR) were immunohistologically investigated in 107 patients with gastric cancer who underwent curative resection. Both ER and PgR were detected only in the cancer cell nucleus. The ER positive rate was 27.

View Article and Find Full Text PDF

Estrogen receptors (ER) were examined in cytosol, nuclear potassium chloride (KCl) extractable fraction, and nuclear KCl unextractable fraction by the dextran-coated charcoal adsorption method in various gastric cancer tissue. The overall ER-positive rate in the cytosol and nuclear fraction was 19.2%.

View Article and Find Full Text PDF

In order to elevate the detection rate of breast cancer in mass-screening, we examined whether the C-mode display ultrasonography is useful for detection of breast cancer. 1) Diagnostic sensitivity of C-mode ultrasonography was 88.2%, specificity was 66.

View Article and Find Full Text PDF

Eight hundred forty-one patients with biopsy-proven benign breast disease were followed annually in prospective manner for 1-10 years to analyse breast cancer development at aspect of histologic features, age at entry and mammographic patterns by Wolfe. No association was found between patients who developed cancer and those who did not with respect to the initial histologic features. The rate of breast cancer development in patients in thirties was the highest.

View Article and Find Full Text PDF