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M Baba

Publications and source records attributed to M Baba.

At least 19 recordsLinked to original sources
PubMed2006

In situ kinetics study of the accelerated aging of poly(ethylene oxide) using PhotoDSC.

PhotoDSC has been applied to follow the global kinetics of chain scissions resulting from the UV light irradiation or from the thermal degradation of a high molecular weight PEO (4 x 10(6) g x mol(-1)). Infrared spectroscopy, XRD measurements and rheology experiments were performed to evidence the occurrence of chain scissions. Melting energy was used as a tool to quantify the extent of the degradation. It was found that the chain scissions reaction follows a first-order kinetic law for both photo and thermal degradation. The activation energies were found identical in both cases (41 kJ x mol(-1)), whereas the degradation rate was higher in the case of UV irradiation than in the case of thermoageing.

Journal Article↗
PubMed2006

Experimental studies of the deuteron-induced activation cross-sections on natAg.

Excitation functions were measured for the (nat)Ag(d,x)(105,106m,110m)Ag, (nat)Ag(d,x)(107,109)Cd and (27)Al(d,x)(24)Na reactions by the stacked-foil activation technique and high-resolution gamma-spectroscopy over the energy range 0.44-40 MeV. The thick target integral yields were deduced using the measured cross-sections. No experimental data on the (nat)Ag+d process are available in the literature above 27 MeV. The nuclides (105)Ag, (106m)Ag and (109)Cd produced with deuteron induced activation of natural silver have suitable yields and decay characteristics important for thin layer activation (TLA) analysis. The cross-section for the production of (107)Cd and (109)Cd is significantly large. Therefore, the Ag+d process can be an efficient route for the production of isotope with a medium energy accelerator. The results of the model calculation using the TALYS code are not consistent with the present data. A large shift in the incident energy is found in TALYS calculations.

Journal Article↗
PubMed2006

Carbon tetrachloride as a thermoporometry liquid probe to study the cross-linking of styrene copolymer networks.

Mesh size distributions (MSDs) of swollen cross-linked styrene copolymer networks have been measured by thermoporometry using CCl(4) as a probe liquid. All numerical relationships required for the calculation of the MSD were established for both the liquid-to-solid and the solid-to-solid thermal transitions of CCl(4) and successfully validated on test samples. It was found that the polymer network, for both thermally and photo-cross-linked materials, was completely built in about 4 h of exposure. A clear correlation was established between the average mesh size of the swollen polymer network on one hand and the benzoyl peroxide groups content and swelling ratio on the other hand.

Algorithms↗
PubMed2006

New filarial nematode from Japanese serows (Naemorhedus crispus: Bovidae) close to parasites from elephants.

A new onchocercid species, Loxodontofilaria caprini n. sp. (Filarioidea: Nematoda), found in subcutaneous tissues of 37 (33%) of 112 serows (Noemorhedus crispus) examined in Japan, is described. The female worm had the characteristics of Loxodontofilaria, e.g., the large body size, well-developed esophagus with a shallow buccal cavity, and the long tail with three caudal lappets. The male worm of the new species, which was first described in the genus, had unequal length of spicules, 10 pairs of pre- and post-caudal papillae, and three terminal caudal lappets. Deirids were present in both sexes. Among four species of the genus loxodontofiloria: one from the hippopotamus and three from the Elepantidae, L. caprini n. sp. appears close to L. asiatica Bain, Baker & Chabaud, 1982, a subcutaneous parasite of Elephas indicus in Myanmar (Burma). However, L. caprini n. sp. is distinct from L. asiatica in that the Japanese female worm has an esophagus half as long and the microfilariae also half as long with a coiled posterior. The microfilariae were found in the skin of serows. The new parasite appears to clearly illustrate a major event in the evolution of onchocercids: the host-switching. This might have occurred on the Eurasian continent, where elephantids and the lineage of rupicaprines diversified during the Pliocene-Pleistocene, or in Japan, into which some of these hosts migrated.

Animals↗
PubMed2006

Transbronchial fine needle aspiration cytological examination: a useful tool for diagnosing primary lung cancer.

BACKGROUND: Obtaining a definitive preoperative diagnosis plays a critical role in deciding upon the treatment approach for lung carcinoma. However, success in making definitive diagnoses of small primary lung cancers will require new approaches because these cancers are difficult to detect using standard biopsy procedures. METHODS: We evaluated the results of morphologic definitive diagnosis together with various clinical factors in 1003 primary lung cancers resected surgically. Patients underwent transbronchial brushing, fine needle aspiration cytology, forceps biopsy, and/or forceps biopsy-stamp cytology for preoperative diagnoses, in conjunction with the use of Diff-Quik to confirm that hits had been made on the radiographic shadows before terminating the examinations. RESULTS: Sensitivities of the diagnostic procedures for primary lung cancers were as follows: 64.8% for brushing, 56.1% for transbronchial forceps biopsy, 72.0% for transbronchial forceps biopsy-stamp cytology, and 86.4% for transbronchial fine needle aspiration. The four transbronchial biopsy procedures had a combined overall sensitivity of 92.7%. In patients with peripheral lung cancers of 2 cm or less in diameter, transbronchial fine needle aspiration had a sensitivity of 75.9%, which was the highest sensitivity for all transbronchial examinations. In the subset of 296 patients who underwent all four transbronchial biopsy examinations, transbronchial fine needle aspiration had the highest sensitivity of preoperative diagnosis of all the transbronchial examination methods. CONCLUSIONS: The sensitivity of preoperative cytological diagnosis for primary lung cancers, especially transbronchial aspiration cytology, is high. Transbronchial fine needle aspiration cytology is useful for the preoperative diagnosis of primary lung cancer.

Adolescent↗
PubMed2005

Differential absorbed dose distributions in lineal energy for neutrons and gamma rays at the mono-energetic neutron calibration facility.

Absorbed dose distributions in lineal energy for neutrons and gamma rays of mono-energetic neutron sources from 140 keV to 15 MeV were measured in the Fast Neutron Laboratory at Tohoku University. By using both a tissue-equivalent plastic walled counter and a graphite-walled low-pressure proportional counter, absorbed dose distributions in lineal energy for neutrons were obtained separately from those for gamma rays. This method needs no knowledge of energy spectra and dose distributions for gamma rays. The gamma-ray contribution in this neutron calibration field >1 MeV neutron was <3%, while for <550 keV it was >40%. The measured neutron absolute absorbed doses per unit neutron fluence agreed with the LA150 evaluated kerma factors. By using this method, absorbed dose distributions in lineal energy for neutrons and gamma rays in an unknown neutron field can be obtained separately.

Absorption↗
PubMed2005

Clinical and electrophysiologic correlates of IVIg responsiveness in CIDP.

To identify clinical and electrophysiologic features related to IV immunoglobulin (IVIg) responsiveness in chronic inflammatory demyelinating polyneuropathy (CIDP), the authors conducted a multicenter study on 312 patients with CIDP (199 responders and 113 nonresponders). Muscle atrophy and decreased compound muscle action potential were pronounced in nonresponders of IVIg. Male gender, longer disease duration, and slow progression of symptoms were also associated with IVIg unresponsiveness. Features suggesting axonal dysfunction in peripheral nerves indicated IVIg unresponsiveness in CIDP.

Adult↗
PubMed2005

Activation cross-sections of long-lived products of proton-induced nuclear reactions on zinc.

In the frame of a systematic study of excitation functions induced by medium energy protons, the activation cross-sections on natural zinc were investigated for different applications. Excitation functions for production of 66,67Ga, 62,65,69mZn, 64Cu, 57Ni, 55,56,57,58Co and 52,54Mn radioisotopes were measured by the stacked foil technique in the energy range of 26-67 MeV. Results were compared with the earlier reported experimental data and theoretical calculations based on the ALICE-IPPE code. Experimental data are presented for the first time for most of the products in the investigated energy range. Applications of the measured data for validating the cross-sections on highly enriched isotopic Zn targets and for thin layer activation method are discussed.

Computer Simulation↗
PubMed2005

Experimental studies on excitation functions of the proton-induced activation reactions on silver.

Excitation functions were measured for the production of 106m,105Ag, 103,101,100Pd, 105,102,101m,100,99Rh and 97Ru via proton-induced activation reactions on natural silver using a stacked foil technique in the energy range 11-80 MeV. The residual activity measurements were carried out nondestructively by the high-resolution HPGe gamma-ray spectroscopy. Thick target integral yields were deduced using the measured cross-sections from the respective threshold energies of the investigated reactions up to 80 MeV. The present work gives new results for the investigated radionuclides. The data in MENDL-2P deduced with the theoretical model code ALICE-IPPE are consistent in shape with the measured values, but show disagreement in magnitude.

Journal Article↗
PubMed2005

Experimental studies on excitation functions of the proton-induced activation reactions on yttrium.

Proton-induced activation cross-sections were measured for the (89)Y(p,x)(89,88,86)Zr, (89)Y(p,x)(88,87,87 m,86)Y, (89)Y(p,x)(85,83,82)Sr and (89)Y(p,x)(84,83)Rb reactions by a stacked foil technique in the energy range 15-80 MeV which was covered by two separate measurements for 15-50 and 32-80 MeV energy range with 50 and 80 MeV incident protons. The differences between the results of two irradiations were found within 6% in the overlapping energy regions. The production yields for the long-lived products like (88)Zr, and (88)Y are significantly larger than that of (nat)Mo+p, (nat)Nb+p and (nat)Zr+p processes. The productions of the medical isotopes, (85)Sr and (83)Sr are also effective by Y+p process using an 80 MeV beam. Thick target integral yields were also deduced using the measured cross-sections. The (87)Y, (88)Y, (88)Zr and (89)Zr radionuclides have suitable yields and decay characteristics important for thin-layer activation (TLA) analysis.

Journal Article↗
PubMed2005

Age associated axonal features in HNPP with 17p11.2 deletion in Japan.

OBJECTIVE: To clarify age related changes in the clinicopathological features of hereditary neuropathy with liability to pressure palsy (HNPP) in Japanese patients with deletion of 17p11.2, particularly concerning axonal abnormalities. METHODS: Forty eight proband patients from 48 HNPP families were assessed as to clinical, electrophysiological, and histopathological features, including age associated changes beyond those in controls. RESULTS: Motor conduction studies showed age associated deterioration of compound muscle action potentials in nerves vulnerable to repetitive compression (median, ulnar, and peroneal nerves), but not in others such as the tibial nerve. Sensory conduction studies revealed more profound reduction of action potentials than motor studies with little age related change. Large myelinated fibre loss was seen in the sural nerve irrespective of age at examination. CONCLUSIONS: Irreversible axonal damage may occur at entrapment sites in motor nerves in HNPP patients, progressing with aging. Sensory nerves may show more profound axonal abnormality, but without age association. The electrophysiological features of HNPP are presumed to be a mixture of abnormalities occurring from early in life and acquired features caused by repetitive insults at entrapment sites. Unlike Charcot-Marie-Tooth disease type 1A, age associated axonal damage may not occur unless the nerves are subjected to compression.

Action Potentials↗
PubMed2005

Colorimetric lactate dehydrogenase (LDH) assay for evaluation of antiviral activity against bovine viral diarrhoea virus (BVDV) in vitro.

A rapid and sensitive screening assay has been established for in vitro evaluation of antiviral compounds against bovine viral diarrhoea virus (BVDV), which is widely used as a surrogate for hepatitis C virus (HCV). The procedure is based on photospectrometrical assessment for the viability of virus-infected cells via extracellular leakage of lactic dehydrogenase (LDH). The level of LDH in culture supernatants of BVDV-infected Madin-Darby bovine kidney (MDBK) cells was significantly higher than those of mock-infected MDBK cells. Under optimized assay conditions, the LDH level was found to correlate well with the degree of viral replication. When the 50% effective concentrations (EC50s) of ribavirin, cyclosporine A and human interferon-alpha for BVDV replication were determined by the established LDH method and compared with those obtained by a conventional tetrazolium colorimetric (MTT) method, there was a complete correlation in EC50s between the two methods. Furthermore, a much higher ratio of background activity (noise) to sample activity (signal) could be achieved with the LDH method than with the MTT method, indicating that the present LDH assay permits a sensitive, rapid and reliable screening of compounds for their anti-BVDV activity and may be useful for the discovery of novel anti-HCV agents.

Animals↗
PubMed2004

Experimental studies on the proton-induced activation reactions of molybdenum in the energy range 22-67 MeV.

The production cross-sections of (99,93m)Mo, (96,95,95m,94)Tc, (96,95,92m,90)Nb, (89,88,86)Zr and (88,87,86)Y radionuclides for proton-induced reactions on molybdenum were measured with molybdenum targets of natural isotopic composition using a stacked-foil activation technique in the energy range 22-67 MeV. The thick target integral yields were also deduced for each reaction using the measured cross-sections from the respective threshold up to 67 MeV. The results have given new data for all of the investigated radionuclides. The results of the present experiment showed excellent agreement with the earlier reported data in the lower energy region.

Journal Article↗
PubMed2004

Benchmark experiments for cyclotron-based neutron source for BNCT.

In the previous study, we found the feasibility of a cyclotron-based BNCT using the Ta(p,n) neutrons at 90 degrees bombarded by 50 MeV protons, and the iron, AlF(3), Al and (6)LiF moderators by simulations using the MCNPX code. In order to validate the simulations to realize the cyclotron-based BNCT, we measured the epithermal neutron energy spectrum passing through the moderators with our new spectrometer consisting of a (3)He gas counter covered with a silicon rubber loaded with (nat)B and polyethylene moderator and the depth distribution of the reaction rates of (197)Au(n,gamma)(198)Au in an acrylic phantom set behind the rear surface of the moderators. The measured results were compared with the calculations using the MCNPX code. We obtained the good agreement between the calculations and measurements within approximately 10% for the neutron energy spectra and within approximately 20% for the depth distribution of the reaction rates of (197)Au(n,gamma)(198)Au in the phantom. The comparison clarified a good accuracy of the calculation of the neutron energy spectrum passing through the moderator and the thermalization in a phantom. These experimental results will be a good benchmark data to evaluate the accuracy of the calculation code.

Boron Neutron Capture Therapy↗
PubMed2003

Long-term survivors of advanced esophageal cancer without surgical treatment: a multicenter questionnaire survey in Kyushu, Japan.

Since the introduction of recent improvements in adjuvant therapy for esophageal cancer, some patients have demonstrated good prognosis. In the present study, we analyzed 3- and 5-year survivors of advanced esophageal cancer who did not undergo any surgical treatment. Between 1990 and 1998, 831 patients were admitted to 14 university hospitals and one cancer center associated with the membership of the Kyushu study group for adjuvant therapy of esophageal cancer. Twelve (1.4%) of the patients were 3-year survivors and 13 (1.6%) were 5-year survivors. The reasons for non-operation were refusal (eight patients), tumor-related factors (11 patients), and host-related factors (six patients). With a single exception, all patients had locally advanced tumors. Almost all long-term survivors had fewer than five lymph node metastases, in regions limited to the neck and/or mediastinum. Radiation therapy was combined with chemotherapy for 16 of the 25 patients, and chemotherapy-based cisplatin was used for 15 of these 16 patients. Fifteen of the patients remain alive; 10 died seven of them from esophageal cancer. Chemoradiation therapy was effective for some patients with locally advanced esophageal cancer, particularly in the absence of or with few lymph node metastases. To improve the prognosis of patients with advanced esophageal cancer who, for various causes, cannot undergo surgical treatment, a new protocol for adjuvant therapy is required.

Aged↗
PubMed2003

A case of bacillary angiomatosis presenting as leg ulcers.

We report a 32-year-old immunocompetent man who had multiple leg ulcers caused by bacillary angiomatosis without a history of direct contact with cats. Bacillary angiomatosis should be kept in mind in the differential diagnosis of leg ulcers in cases of unknown aetiology.

Adult↗
PubMed2003

The anticonvulsant hypersensitivity syndrome.

BACKGROUND: The anticonvulsant hypersensitivity syndrome is a potentially fatal multisystemic reaction to anticonvulsant medications. OBJECTIVES: The purpose of this study was to investigate the clinical characteristics of anticonvulsant hypersensitivity syndrome. RESULTS: A total 32 subjects, aged from 6 to 72 years, diagnosed as having anticonvulsant hypersensitivity syndrome based on clinical and histopathological findings, were included in the study. In 22 of the 32 cases, the anticonvulsants had been administered prophylactically after craniotomy and in 10 cases for epilepsy. When the cases were assessed for skin lesions, maculopapular eruption was registered in 22, Stevens-Johnson syndrome in five, and toxic epidermal necrolysis (TEN) in five. Treatment included suspension of the offending drug and then, except for the cases with toxic epidermal necrolysis, administration of corticosteroids. The 22 cases that required anticonvulsant therapy were treated with valproic acid. In all cases, we observed rapid clinical improvement corroborated by laboratory findings. CONCLUSIONS: It is essential that due importance be given to the development of an eruption in individuals to whom anticonvulsants are administered after craniotomy because anticonvulsant hypersensitivity syndrome is likely to be life-threatening.

Adolescent↗