Measurements of the neutron activation cross sections for Bi and Co at 386 MeV

Neutron activation cross sections for Bi and Co at 386 MeV were measured by activation method. A quasi-monoenergetic neutron beam was produced using the (7)Li(p,n) reaction. The energy spectrum of these neutrons has a high-energy peak (386 MeV) and a low-energy tail. Two neutron beams, 0° and 25° from the proton beam axis, were used for sample irradiation, enabling a correction for the contribution of the low-energy neutrons. The neutron-induced activation cross sections were estimated by subtracting the reaction rates of irradiated samples for 25° irradiation from those of 0° irradiation. The measured cross sections were compared with the findings of other studies, evaluated in relation to nuclear data files and the calculated data by Particle and Heavy Ion Transport code System code.

Risk factors for major morbidity after liver resection for hepatocellular carcinoma

Background

Bile leakage, and organ and/or space surgical-site infection (SSI) are common causes of major morbidity after partial hepatectomy for hepatocellular carcinoma (HCC). The purpose of this study was to analyse risk factors for major morbidity and to explore strategies for its reduction after partial hepatectomy for HCC.

Methods

Risk factors for bile leakage and organ/space SSI were analysed in patients who underwent partial hepatectomy for HCC between 2001 and 2010. The causes, management and outcomes of intractable bile leakage requiring endoscopic therapy or percutaneous transhepatic biliary drainage were analysed. In addition, causative bacteria, outcomes and characteristics of organ/space SSI were investigated. Risk factors were identified using multivariable analysis.

Results

Some 359 patients were included in the analysis. The prevalence of bile leakage and organ/space SSI was 12·8 and 8·6 per cent respectively. Repeat hepatectomy and an operating time of at least 300 min were identified as independent risk factors for bile leakage. The main causes of intractable bile leakage were latent strictures of the biliary system caused by previous treatments for HCC and intraoperative injury of the hepatic duct during repeat hepatectomy. Independent risk factors for organ/space SSI were repeat hepatectomy and bile leakage. Methicillin-resistant Staphylococcus aureus was detected more frequently in organ/space SSI after repeat hepatectomy than after initial partial hepatectomy.

Conclusion

Repeat hepatectomy and prolonged surgery were identified as risk factors for bile leakage after liver resection for HCC. Bile leakage and repeat hepatectomy increased the risk of organ/space SSI.

Analysis of the effect of structural materials in a wall-less tissue-equivalent proportional counter irradiated by 290 MeV u(-1) carbon beam

Effects of structural materials in a wall-less tissue-equivalent proportional counter were evaluated based on the calculation of energy deposits by EGS5 and the measurement of lineal energy distributions using 290 MeV u(-1) carbon beams. It is found that the correction of measured data based on simulation is necessary for understanding the energy deposition spectra in the homogeneous condition in tissues.

Development of a quasi-monoenergetic neutron field using the 7Li(p,n)7Be reaction in the energy range from 250 to 390 MeV at RCNP

A quasi-monoenergetic neutron field using the (7)Li(p,n)(7)Be reaction has been developed at the ring cyclotron facility at the Research Center for Nuclear Physics (RCNP), Osaka University. Neutrons were generated from a 10-mm-thick Li target injected by 250, 350 and 392 MeV protons and neutrons produced at 0 degrees were extracted into the time-of-flight (TOF) room of 100-m length through the concrete collimator of 10 x 12 cm aperture and 150 cm thickness. The neutron energy spectra were measured by a 12.7-cm diam x 12.7-cm long NE213 organic liquid scintillator using the TOF method. The peak neutron fluence was 1.94 x 10(10), 1.07 x 10(10) and 1.50 x 10(10) n sr(-1) per muC of 250, 350 and 392 MeV protons, respectively. The neutron spectra generated from various thick (stopping length) targets of carbon, aluminium, iron and lead, bombarded by 250 and 350 MeV protons, were also measured with the TOF method. Although these measurements were performed to obtain thick target neutron yields, they are also used as a continuous energy neutron field. These neutron fields are very useful for characterising neutron detectors, measuring neutron cross sections, testing irradiation effects for various materials and performing neutron shielding experiments.

Darwin: dose monitoring system applicable to various radiations with wide energy ranges

A new radiation dose monitor, designated as DARWIN (Dose monitoring system Applicable to various Radiations with Wide energy ranges), has been developed for real-time monitoring of doses in workspaces and surrounding environments of high-energy accelerator facilities. DARWIN is composed of a phoswitch-type scintillation detector, which consists of liquid organic scintillator BC501A coupled with ZnS(Ag) scintillation sheets doped with (6)Li, and a data acquisition system based on a Digital-Storage-Oscilloscope. DARWIN has the following features: (1) capable of monitoring doses from neutrons, photons and muons with energies from thermal energy to 1 GeV, 150 keV to 100 MeV and 1 MeV to 100 GeV, respectively, (2) highly sensitive with precision and (3) easy to operate with a simple graphical user-interface. The performance of DARWIN was examined experimentally in several radiation fields. The results of the experiments indicated the accuracy and wide response range of DARWIN for measuring dose rates from neutrons, photons and muons with wide energies. It was also found from the experiments that DARWIN enables us to monitor small fluctuations of neutron dose rates near the background level because of its high sensitivity. With these properties, DARWIN will be able to play a very important role for improving radiation safety in high-energy accelerator facilities.

Extension of applicable neutron energy of DARWIN up to 1 GeV

The radiation-dose monitor, DARWIN, needs a set of response functions of the liquid organic scintillator to assess a neutron dose. SCINFUL-QMD is a Monte Carlo based computer code to evaluate the response functions. In order to improve the accuracy of the code, a new light-output function based on the experimental data was developed for the production and transport of protons deuterons, tritons, (3)He nuclei and alpha particles, and incorporated into the code. The applicable energy of DARWIN was extended to 1 GeV using the response functions calculated by the modified SCINFUL-QMD code.

Physiological and molecular biological characterization of intracellular carbonic anhydrase from the marine diatom Phaeodactylum tricornutum

A single intracellular carbonic anhydrase (CA) was detected in air-grown and, at reduced levels, in high CO(2)-grown cells of the marine diatom Phaeodactylum tricornutum (UTEX 642). No external CA activity was detected irrespective of growth CO(2) conditions. Ethoxyzolamide (0.4 mM), a CA-specific inhibitor, severely inhibited high-affinity photosynthesis at low concentrations of dissolved inorganic carbon, whereas 2 mM acetazolamide had little effect on the affinity for dissolved inorganic carbon, suggesting that internal CA is crucial for the operation of a carbon concentrating mechanism in P. tricornutum. Internal CA was purified 36.7-fold of that of cell homogenates by ammonium sulfate precipitation, and two-step column chromatography on diethylaminoethyl-sephacel and p-aminomethylbenzene sulfone amide agarose. The purified CA was shown, by SDS-PAGE, to comprise an electrophoretically single polypeptide of 28 kD under both reduced and nonreduced conditions. The entire sequence of the cDNA of this CA was obtained by the rapid amplification of cDNA ends method and indicated that the cDNA encodes 282 amino acids. Comparison of this putative precursor sequence with the N-terminal amino acid sequence of the purified CA indicated that it included a possible signal sequence of up to 46 amino acids at the N terminus. The mature CA was found to consist of 236 amino acids and the sequence was homologous to beta-type CAs. Even though the zinc-ligand amino acid residues were shown to be completely conserved, the amino acid residues that may constitute a CO(2)-binding site appeared to be unique among the beta-CAs so far reported.

Prophenoloxidase-activating enzyme of the silkworm, Bombyx mori. Purification, characterization, and cDNA cloning

Prophenoloxidase-activating enzyme (PPAE) was purified to homogeneity as judged by SDS-polyacrylamide gel electrophoresis from larval cuticles of the silkworm, Bombyx mori. The purified PPAE preparation was shown to be a mixture of the isozymes of PPAE (PPAE-I and PPAE-II), which were eluted at different retention times in reversed-phase high performance liquid chromatography. PPAE-I and PPAE-II seemed to be post translationally modified isozymes and/or allelic variants. Both PPAE isozymes were proteins composed of two polypeptides (heavy and light chains) that are linked by disulfide linkage(s) and glycosylated serine proteases. The results of cDNA cloning, peptide mapping, and amino acid sequencing of PPAE revealed that PPAE is synthesized as prepro-PPAE with 441 amino acid residues and is activated from pro-PPAE by cleavage of a peptide bond between Lys152 and Ile153. The homology search showed 36.9% identity of PPAE to easter, which is a serine protease involved in dorso-ventral pattern formation in the Drosophila embryo, and indicated the presence of two consecutive clip-like domains in the light chain. A single copy of the PPAE gene was suggested to be present in the silkworm genome. In the fifth instar larvae, PPAE transcripts were detected in the integument, hemocytes, and salivary glands but not in the fat body or mid gut. A polypeptide cross-reactive to mono-specific anti-PPAE/IgG was transiently detected in the extract of eggs between 1 and 3 h after they were laid.

Effects of isoflurane on oxygenation during one-lung ventilation in pulmonary emphysema patients

BACKGROUND

Hypoxic pulmonary vasoconstriction has an important role in human one-lung ventilation (OLV) in the lateral decubitus position under general anesthesia. During OLV, inhalational anesthesia may inhibit hypoxic pulmonary vasoconstriction and the decrease in arterial oxygenation. We studied the effect of isoflurane administration on arterial oxygen tension in chronic obstructive pulmonary disease patients.

METHODS

Ten patients who had thoracoscopic laser ablation of bullous emphysema were studied. Patients received 2% isoflurane in oxygen from induction until the first 20 min of OLV in the lateral decubitus position, then were switched to 1% isoflurane lasting 20 min and next were switched to 0.5% isoflurane lasting 20 min. After each 20-min inhalation, pulmonary and hemodynamic parameters were measured. The given concentrations for isoflurane were merely vapor meter concentrations.

RESULTS

PaO2/FIO2, Qs/Qt respiratory rate peak inspiratory pressure and PaCO2 showed no significant changes at each point of isoflurane. Expiratory tidal volume significantly decreased (P < 0.05) with 0.5% isoflurane compared to that with 2% isoflurane. Cardiac output, mean arterial pressure, mean pulmonary arterial pressure, systemic vascular resistance and pulmonary vascular resistance showed no significant changes at each point of isoflurane.

CONCLUSIONS

In patients with pulmonary emphysema, arterial oxygenation is not affected by low isoflurane concentration during OLV in the lateral decubitus position.

Effect of surfactant on respiratory failure associated with thoracic aneurysm surgery

OBJECTIVE

To study the effects of surfactant administration on the left lung after surgical repair of descending aortic aneurysms on postoperative respiratory failure.

DESIGN

Randomized, prospective, controlled study.

SETTING

Clinical investigation.

PATIENTS

Eleven patients with respiratory failure associated with thoracic aneurysm surgery.

INTERVENTION

Eleven adult patients with acute respiratory failure (PaO2/FIO2 <300 torr [<40 kPa]) after surgical repair of descending aortic aneurysms. The artificial surfactant (30 mg/kg) was given to the operated side of the lung by intrabronchial instillation in six patients (surfactant group), whereas nothing was instilled in the other five patients (control group).

MEASUREMENTS AND MAIN RESULTS

Hemodynamic parameters, blood gas, and peak inspiratory pressure were measured at the end of surgery, before surfactant instillation, and at 2, 6, 12, 24, and 48 hrs after surfactant instillation. At the end of surgery, the mean +/- SEM values of the PaO2/FIO2 ratio were 204 +/- 25 torr (27.2 +/- 3.3 kPa) in the surfactant group and 240 +/- 26 torr (32.0 +/- 3.5 kPa) in the control group. After 2, 6, 12, and 48 hrs, improvements in the PaO2/FIO2 ratios were observed in the surfactant group, whereas the control group showed no improvement. Two hours after surfactant instillation, the mean value in the PaO2/FIO2 ratio was significantly higher in the surfactant group (318 +/- 24 torr [42.4 +/- 3.2 kPa]) (p < .05) compared with the control group values (240 +/- 34 torr [32 +/- 4.5 kPa]).

CONCLUSION

Surfactant administration immediately after surgery restored gas exchange in postoperative respiratory failure associated with thoracic aneurysm surgery.

An evaluation of neuromuscular reversal with edrophonium in a patient with malathion intoxication

We evaluated the neuromuscular reversal with edrophonium using peripheral nerve stimulator and recorder in a patient with malathion intoxication. Edrophonium 10 mg i.v. caused an increase in single twitch tension by 76% of the control during the recovery phase from an acute cholinergic crisis 16 days after ingestion of malathion solution. The present study indicated that edrophonium test seems to be a reliable monitoring in evaluating neuromuscular reversal in the patient with acute malathion insecticide poisoning.

Neuromuscular blocking actions of the aminoglycoside antibiotics sisomicin and micronomicin in the rabbit

The neuromuscular blocking actions of sisomicin sulfate (SISO), micronomicin sulfate (MCR) and d-tubocurarine (dTc) were studied in 20 rabbits anesthetized with halothane. The i.v. administration of SISO 20-40 mg/kg, MCR 40-80 mg/kg or dTc 0.1-0.3 mg/kg resulted in dose-dependent decreases in twitch tension. The ED50s for SISO, MCR and dTc were 23.5, 58.2 and 0.2 mg/kg, respectively. SISO- and MCR-induced neuromuscular blockade was partially antagonized by neostigmine or by calcium.

[The effect of surfactant therapy associated with high frequency jet ventilation on oxygenation in canine lavaged lungs]

The effects of exogenous surfactant (SF) replacement therapy associated with high frequency jet ventilation (HFJV) on blood gas changes, pulmonary and hemodynamic variables were studied in canine lavaged lungs. The lungs were lavaged repeatedly with physiological saline until PaO2 decreased to 100 mmHg under intravenous pentobarbital anesthesia with 100% oxygen. SF (50 mg.kg-1) in the experimental group (n = 12) and saline in the control group (n = 8) were administered to the trachea using HFJV with a duration of 10 min. HFJV was further continued for 1 hour to make surfactant distribute evenly. Then respiration was controlled by the conventional mechanical ventilator for 3 hrs. During the administration of SF (10 min). PaCO2 was not altered. In the surfactant group, PaO2 improved significantly (200 mmHg) at the end of HFJV and was maintained for the next 3 hrs at this level, but it did not improve in the saline group. Therefore, we suggest that HFJV can be used safely for the treatment of acute respiratory failure and is an effective method for the administration of the pulmonary surfactant into the alveoli.

Cardiac glycosides. 6. Gitoxigenin C16 acetates, formates, methoxycarbonates, and digitoxosides. Synthesis and Na+,K+-ATPase inhibitory activities

A series of 17 gitoxigenin 16 beta-formates, acetates, and methoxycarbonates was synthesized, including their 3 beta-acetates, formates, and digitoxosides. A 16 beta-formate group was generally found to increase activity 30 times, a 16 beta-acetate group 9-12 times, while a 16 beta-methoxycarbonate decreased activity by two-thirds. 3 beta-Formates and acetates had little effect on activity by themselves, but sometimes reduced the activity-increasing properties of 16 beta-formates and acetates. A 3 beta-digitoxoside increases the activity of gitoxigenin by 15 times, but the effect is less if the 16 beta-group is esterified. And finally, a 16-one decreases activity dramatically. These data suggest an important role for C16 esters and possibly the presence of a separate binding site on Na+,K+-ATPase corresponding to the cardenolide C16 position.